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MLT Clinical Chemistry > Unit 2 > Flashcards

Unit 2 Flashcards

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1
Q

Describe absorption spectroscopy

A
  • a spectroscopy is a spectroscopic technique that is used for measuring the absorption as it interacts with the sample. The radiation could be a function of either frequency or wavelength
    -related to the absorption spectrum because the sample used to interacts with electro magnitude radiation (EMR) in the form of photons from the radiating field
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2
Q

Describe absorption spectrum

A

To the frequencies of light transmitted with dark bands when the electrons absorb energy in the ground state to reach higher energy states

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3
Q

What does the intensity of the absorption depend on?

A

Differs depending on frequency and this variation is the absorption spectrum

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4
Q

What provides the principle means of measuring analytes in biological fluids?

A

Interaction of EMR in the form of photons with matter

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5
Q

Describe scattering of radiation

A
  • transmission of radiation i n matter can babe viewed as a momentary retention of the radiant energy by atoms, ions or molecules followed by reemission of the radiation in all directions as the particles return to their original electronic state
  • types:
    —Rayleigh scatter
    —Tyndall effect
    — Raman scatter
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6
Q

Describe Rayleigh scatter

A
  • light scatter by molecules or aggregates of particles with dimensions significantly smaller than the wavelength of the radiation
  • examples: blue color of sky
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7
Q

Describe Tyndall effect q

A
  • occurs with particles of colloidal dimensions
  • can be seen with the naked eye
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8
Q

Describe Raman scatter

A
  • involves absorption of photons producing vibrational excitation
  • always varies from the excitation energy by a constant energy difference
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9
Q

What light does spectrophotometric techniques use?

A
  • ultraviolet or visible light
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10
Q

Describe graphs of absorption spectroscopy

A
  • percent transmittance versus concentration
  • absorbance versus concentration
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11
Q

Describe lamberts law

A
  • states that for parallel monochromatic radiation that passes through an absorber material of constant concentration, the radian power decreases logarithmaically as the light path increases arithmetically
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12
Q

What did lambert law prove?

A
  • that for monochromatic radiation that passes through an absorber of constant concentration, there is logarithmic decrease in the radiant power as the light path increases arithmetically
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13
Q

Describe Beer-Lambert law

A
  • based on previous work by Lambert, Beer discovered that for monochromatic radiation, absorbance is directly proportional to the light path, b, through the medium and the concentration , c, of the absorbing species
    —> the work culminated in the Beer-Lambert law, or simple beers law
  • concentration of the analyte in solution can be determind by several different methods based on the Beer-Lambert law
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14
Q

What is the equation to show the relationship between transmittance and absorbance?

A

A = log1/T = log100%/%T = log100-log%T
A= 2 - log(v10)%T

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15
Q

What equations can be used to determine the concentration of the analyte in a solution?

A

At= a x Ct x b
As = a x Cs x b

  • At = absorbance of test
  • As = absorbance of standard
  • Ct = concentration of test analyte
  • Cs = concentration of standard
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16
Q

What are the 5 significant components in either a single- or double-beam configuration of a spectrophotometer?

A
  1. Stable source of radiant energy
  2. A device that isolates a specific region of the electromagnetic spectrum
  3. A sample holder
  4. a photo detector
  5. A read-out device
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17
Q

Describe radiant energy sources of a spectrophotometer

A
  • provide polychromatic light
  • must generate sufficient radiant energy or power to measure the analyte of interest
  • two type:
    —> continuum
    —> line
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18
Q

Describe the continuum radiant energy source

A
  • emits radiation that changes in intensity vertically slowly as a function of wavelength
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19
Q

Describe the line radiant energy source

A
  • emit a limited number of discrete lines or bands of radiation
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20
Q

Describe monochromators

A
  • spectroscope modified for selective transmission of a narrow band of the spectrum
  • quality of a monochromator is described by:
    —> normal wavelength
    —> Effective bandwidth
    —> Bandpass
    —> Filters
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21
Q

Describe normal wavelength

A
  • wavelength in nanometers at peak light transmittance
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22
Q

Describe effective bandwidth

A
  • range of wavelengths at a point halfway between the baseline and the peak
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23
Q

Describe Bandpass

A
  • total range of wavelengths transmitted
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24
Q

What types of filters are used in monochromators?

A
  • absorption filter
  • interference filters
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25
Q

Describe prism monochromators

A
  • types
    —> 60-degree
    —> 30-degree
  • depends on refraction of radiation by the prism material
  • dispersive power depends on the variation of the refractive index with wavelength
  • ray of radiation that enters prism at an angle of incidence is bent away from vertical
  • dispersed light appears the spectrum of colors that make up the incident radiation
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26
Q

Describe grating monochromators

A
  • the surface is characterized as an array of a very large number of slits spaced equidistant from each other that reflect or transmit radiation
  • only at certain definite angles is radiation of any given wavelength in phase, at others angles, the waves from the slits destructively interfere
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27
Q

What does the quality of grating depend on?

A

1) straightness of the grooves
2) the degree of parallelism
3) the equidistant of the grooves to each other

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28
Q

Describe cuvettes

A
  • cell hold samples and reagents that are made of material transparent to radiation in the spectral region of interest
  • flow-cell or flow-through cuvette
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29
Q

Describe radiation transducer

A
  • a device that converts one form of energy to another
    —> photovoltaic or barrier layer cell
    —> vaccuum phototubes
    —> photo multiplier tubes
    —> silicon diode transducers
    —> multichannnel photon transducers
    —> photodiode arrays
    —> charge-transfer devices
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30
Q

Describe signal processors and readout

A
  • processing of an electrical signal received from a transducer is accomplished by a device that:
    1. Amplifies the electronic signal
    2. Rectifies alternating current (ac) to direct current (dc) or the reverse
    3. Alters the phase of the signal
    4. Filters it to remove unwanted components
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31
Q

What photometric parameters should be monitored periodically to ensure optimal performance?

A
  • wavelength accuracy
  • bandwidth
  • photometric accuracy
  • linearity
  • stray light
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32
Q

What does accuracy suggest?

A

The closeness of a measurement to its true value

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33
Q

What is used to assess photometric accuracy?

A
  • glass filters or solutions that have known absorbance values for a specific wavelength
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34
Q

What devices are used to determine linearity of the spectrophotometer?

A
  • stray light
  • spectroscope
  • colorimeter
  • photometer
  • spectrometer
  • spectrophotometers
  • single-beam instrument
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35
Q

Describe stray light

A
  • can have a significant impact on any measurement of absorbance by a solution
  • can be evaluated by using special cutoff filters
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36
Q

Describe spectroscope

A
  • optical instrument used for visual identification of atomic emission lines
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37
Q

Describe colorimeter

A
  • user compares the observed color of the unknown sample to a standard or a series of colored standards of known concentrations
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38
Q

Describe photometer

A
  • consists of a light source, monochromatic filter and photoelectric transducer, signal processors and readout
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39
Q

Describe spectrometer

A
  • an instrument that provides information about intensity of radiation as a function of wavelength or frequency
  • single-beam instruments represents the simplest type of spectrometer
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40
Q

Describe spectrophotometers

A
  • spectrometers equipped with one or more exit slits and photoelectron transducers that permit determination of the ratio of the power of two beams as a function of wavelength
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41
Q

Describe double-beam instrument

A
  • splits or chops the monochromatic beam of radiation into two components
  • two fundamental
    —> double beam in space
    —> double beam in time
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42
Q

Describe reflectometer

A
  • a filter photometer that measures the quantity of light reflected by a liquid sample that has been dispensed onto a non polished surface
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43
Q

What are 2 types of reflectance?

A
  • specular reflectance
  • diffuse reflectance
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44
Q

Describe specular reflectance

A
  • occurs on a polished surface, where the angle of incidence of the radiant energy is equal to the angle of reflection
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45
Q

Describe diffuse reflectance

A
  • occurs on nonpolished surfaces
  • occurs within the layers and depends on the properties and characteristics of the layers themselves
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46
Q

What are components of a reflectometer?

A
  • similar to photometer
  • Tungten-quartz halide lamp serves as a source of polychromatic radiation
  • light passes through a slit and is directed onto the surface of a urine dipstick pad or dry slide
  • A wavelength selector, such as stationary filter or filter wheel for multiple analytes, is used to isolate the wavelength of interest
  • solid-state photodiode are typically used to detect the reflected radiant energy
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47
Q

Describe the Atomic Absorption Spectroscopy (AAS)?

A
  • used for quantitative analysis or metals such as calcium, lead, copper and lithium
  • time-consuming to perform, is labor intensive and requires meticulous laboratory techniques
  • measures the amount of EMR absorbed by elements in their ground state
  • amount of absorbed radiation is directly proportional to the concentration of of the metal in solution (G-degree)
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48
Q

What is used for molecular luminescence spectroscopy?

A

Fluorometry

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49
Q

Describe fluorometry

A
  • fluorescent spectroscopy is widely used because of its inherent high sensitivity and high specificity
  • high specificity results from dependence on two spectra and the possibility of measuring the lifetimes of the fluorescent state (excitation and emission spectra)
  • compounds that are excited at the same wavelength but emit at different wavelengths are readily differentiated
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50
Q

What is the principle of luminescence fluorometry?

A
  • based on an energy exchange process that occurs when valence shell electrons absorb EMR, become excited, and return to an energy level lower than their original level
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51
Q

What is the principle of fluorescence fluorometry?

A

Light emission from a singlet-excited state

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52
Q

Describe principles of phosphorescence fluorometry

A

Light emission from an excited triplet state

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53
Q

Describe instrumentation of fluorometry

A
  • conventional design of fluorometers places the detector at a 90-degree angle to the polychromatic light source
  • sources:
    —> intensity
    —> wavelength distribution of emitted radiation stability
  • filters and monochromators
  • transducers
  • cuvettes or cells
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54
Q

Describe transducers of fluorometry

A
  • PMTs are the most common transducers found in fluorescent instruments
  • newer fluorometers on the market today use diode-array and CTDs
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55
Q

Describe cuvette or cells of fluorometry

A
  • used for fluoroscent measurement may be rectangular or cylindrical
  • may be made of glass or quartz
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56
Q

Describe applications of fluorescent spectroscopy

A
  • fluorescence polarization immunoassay
  • time-resolved fluorescent immunoassay
  • front-surface fluorometry
  • chemiluminescence
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57
Q

Describe fluorescence polarization immunoassay

A
  • measurement of fluoroscent-labeled bound fraction is determined in the presence of fluorescent- labeled free fraction
  • referred to as a homogenous immunoassay
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58
Q

Describe chemiluminescence of fluorometry

A
  • differs from fluorescence and phosphorescence
  • light is produced from a chemical or electrochemical reaction and not from electromagnetic energy stimulation of electrons, resulting in emission of photons
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59
Q

What are light scatter techniques?

A
  • nephelometry
  • turbidimetry
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60
Q

Describe Nephelometry

A
  • measurement of the light scattered by particles in solution
  • typical nephelometer consists of a light source, a collimator, a monochromator, sample cuvette, a stray light trap, and a photo-detector
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61
Q

Describe turbidimetry

A
  • measurement of the reduction in light transmission caused by particle formation
  • light transmitted in the forward direction is detected
  • the amount of light scattered by a suspension of particles depends on the specimen concentration and particle size
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62
Q

What is the principle of refractometry

A
  • based on the refraction of light as it passes through a medium such as glass or water
  • when light passes from one medium into another, the light bam changes its direction at the boundary surface if its speed in the second medium is different from that in the first
  • critical angle: the angle is created by the bending of the light
  • refractivity: the ability of substance to bend light
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63
Q

Describe osmometry

A
  • the measurement of the osmolarity of an aqueous solution such as serum, plasma, or urine
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64
Q

What occurs as osmolarity of solution increases?

A
  1. Osmotic pressure increases
  2. Boiling point is elevated
  3. Freezing point is depresssed
  4. Vapor pressure is depressed
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65
Q

Describe freezing-point osmometer

A
  • consists of a sample chamber containing a stirrer and a thermistor connected to a readout device
  • sample is rapidly supercooled to several degrees below its freezing point
  • then agitated with the stirrer to initiate freezing
  • rate at which this heat of Fusion is released from the ice being rapidly formed reaches equilibrium with the rate of heat removed
    —> known freezing point of solution
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66
Q

What is used in electrochemistry?

A

Potentiometry

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67
Q

Describe potentiometry

A
  • electrical potentials are produced at the interface between metal and ions of that metal in a solution
  • to measure the electrode potential, a constant-voltage source is needed as the reference potential
    —> reference electrode: electrode with a constant voltage
    —> indicator electrode: the measuring electrode
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68
Q

Describe Nernst equation

A
  • measured cell potential is related to the molar concentration by the Nernst equation
  • useful for predicting the elelctrochemical cell potential given the concentrations of oxidized and reduced species for a given electrode system
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69
Q

What is the Nernst equation?

A

Ec = Eo - (RT/nF)lnQ

Ec = cell potential
Eo = cell potential under standard conditions
R = Universal gas constant (8.314 J/(mol*K))
T = temperature
- n = number of electrons transferred in the reaction
F = Faraday constant (96485 C/mol)
Q = Reaction quotient

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70
Q

Describe reference selective electrodes of potentiometry

A
  • in most electro analytical applications, it is desirable the half-cell potential of one electrode be known, constant, and completely insensitive to the composition of the solution under study
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71
Q

What are important attributes of a reference selective electrode?

A
  1. Potential is reversible and obeys the Nernst equation
  2. Electrode exhibits a potential that is constant with time
  3. Electrode returns to its original potential after being subjected to small currents
  4. Electrode exhibits little hysterics or lag with temperature cycling
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72
Q

Describe ion-selective electrode of potentiometry

A
  • ISE is a membrane-based electrochemical transducer capable of responding to a specific ion.
  • ISEs measure ion activities, specifically free ion concentration
  • ISEs provide several advantages over “wet chemistry” and photometric techniques
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73
Q

Describe pH electrodes of potentiometry

A
  • consists of a small bulb located at the tip of the electrode made of layers of hydrated and non hydrated glass
  • inside the electrode is a chloride ion buffer solution
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74
Q

Describe PCO2 electrodes of potentiometry

A
  • a pH electrode contained within a plastic “jacket”
  • a plastic jacket is filled with a sodium bicarbonate buffer and has a gas-permeable membrane across its opening
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75
Q

Describe coulometry

A
  • an analytical method that involves measuring the quantity of electricity (in coulombs) needed to convert the analyte quantitatively to a different oxidation state
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76
Q

What is a coulomb?

A

The quantity of electricity or charge that is transported in one second by a constant current of one ampere

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77
Q

What are laboratory applications of coulometry?

A
  • the measurement of chloride ions in serum, plasma< CSF and sweat samples
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78
Q

Describe Amperometry

A
  • measure meant of the current flow produced by an oxidation-reduction reaction
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79
Q

What are the electrochemical methods used for measuring chloride in samples?

A
  • coulometry
  • amperometry
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80
Q

Describe chloride titrator of amperometry

A
  • includes a pair of silver electrodes that serve as the indicator electrodes
  • when all of the chloride in the sample has been consumed, silver ions appear in excess
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81
Q

Describe PO2 gas-sensing electrode of amperometry

A
  • Clark PO2 electrode consists of a gas-permeable membrane, usually polypropylene, that allows dissolved oxygen to pass through
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82
Q

Describe voltammetry

A
  • comprises of a group of elelctroanalytical methods in which information about the analyte is derived from the measurement of current as a function of an applied potential under conditions that promote polarization of an indicator, or working electrode
  • based on the measurement of a current that develops in an electrochemical cell under conditions of complete concentration polarization
  • a minimal consumption of analyte takes places
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83
Q

Descartes Anodic stripping voltammetry

A
  • measurement of lead in whole blood samples can be performed in the clinical laboratories
  • Technique consists of three major steps:
    1. Reduction of lead and deposition of the lead onto the electrode
    2. “Resting period” in which stirring is halted but the potential remains on the electrode
    3. Lead is stripped from the electrode back into the solution by oxidation to the iconic form
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84
Q

Describe conductometry

A
  • electrolytic conductivity is a measure of the ability of a solution to carry an electric current
  • The reciprocal of resistance, 1/R is called the conductance, given the symbol G, and is expressed in reciprocal ohms, or mhos
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85
Q

Describe Resistivity

A
  • the electrical resistance in ohms measured between opposite faces of a 1.00- centimeters cube of an aqueous solution at a specific temperature
  • measurement is accomplished by using a resistivity meter
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86
Q

Describe Impedance

A
  • electrical impedance measurement is based on the change in electrical resistance across an aperture when a particle in a conductive liquid passes through this aperture
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87
Q

What are separation techniques?

A
  • electrophoresis
  • densitometry
  • chromatography
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88
Q

Describe electrophoresis

A
  • separation of charged compounds, typically proteins, applied to a solid or semisolid support and immersed in a liquid medium
  • pH at which an amino acid exists mainly as the zwitterion is called the isoelectric point and the pH at that point is called the pI
  • conductivity of a solution increases with its total ionic concentration
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89
Q

Describe densitometry

A
  • basically an absorbance measurement
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90
Q

Describe Densitometer

A
  • measures the absorbance of the stained compounds on a support medium or electrophoretic strip
  • light source, monochromator, and movable carriage to move the electrophoretic strip between the monochromator and photodiode and a photodetector
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91
Q

Describe capillary electrophoresis

A
  • typical CE system consists of a fused silica capillary, two electrolyte buffer reservoirs, a high-voltage power supply, and a detector lined to a data acquisition unit
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92
Q

What is electroosmosis?

A

Motion of a liquid when a voltage is applied between the ends of an insulating tube that contains that liquid

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93
Q

Describe isoelectric focusing

A
  • IEF techniques are similar to electrophoresis except that the separating molecules migrate through a pH gradient
  • pH gradient is created by adding acid to anodic area of the electrolyte cell and adding base to the cathode area
  • has been useful is measuring serum isoenzymes of acid phosphatase, creatine kinase, and alkaline phosphatase
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94
Q

Describe retentions time (Rt) of chromatography

A
  • time it take a compound to elite off the column once it has been injected
  • can be used to determine a compounds identify
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95
Q

Describe resolution (Rs)

A
  • measure of the ability of a column to separate two or more analytes in a sample
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96
Q

What are factors that have a significant impact on the ability of chromatographic system to separate compounds?

A
  • column retention factor (k’)
  • column efficiency (N)
  • column selectivity (alpha)
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97
Q

Describe k’

A
  • strength of solvent: polarity
  • strength of packing material: surface area or amount of stationary phase
  • temperature
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98
Q

Describe N

A
  • flow rate: linear velocity
  • column length
  • average particle of size of packing material
  • viscosity of solvent
  • mass of injection
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99
Q

Describe alpha

A
  • chemistry of solvent: functional groups
  • chemistry of packing material: functional groups
  • chemistry of samples: presence of hydrogen bonds or derivatization
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100
Q

Describe Thin-layer chromatography

A
  • used in many laboratories as an initial screening technique for the detection of drugs of abuse in urine (DAU)
  • stationary phase is manufactured as a thin layer or coating of absorbent that is bonded to a solid support such as glass or plastic
    —> solid absorbent may consist of a basic silica material or a more complex absorbent
  • most compounds have a characteristics identifier known as R1
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101
Q

Describe gas chromatography (GC)

A
  • uses a “carrier” gas to move compounds through a stationary phase located within column
  • widely used technique for decades because of:
    —> high resolution
    —> low detection limits
    —> accuracy
    —> short analytical times
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102
Q

Describe the basic design components of GC

A
  • carrier gas supply
  • sample injection device and GC inlet
  • column
  • detector
  • data system
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103
Q

Describe liquid chromatography (high performance liquid chromatography

A
  • techniques use lower temperature for separation , thereby achieving better separation of thermolabile compounds
  • uses small, rigid supports and special mechanical pumps producing high pressure to pas the mobile phase through the column
  • five commonly used separation techniques:
    —> adsorption
    —> partition
    —> ion exchange
    —> affinity
    —> size exclusion
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104
Q

What does the HPLC instrumentation consists of?

A
  • liquid mobile phase
  • sample injector (manual or automatic)
  • mechanical pump
  • column
  • detector
  • data recorder
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105
Q

What are the two methods for delivery of mobile phases of HPLC instrumentation?

A
  1. Isocratic : used one mobile phase
  2. Gradient: involves the use of two or more mobile phases that are automatically programmed to pump for a specific interval of time
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106
Q

Describe Mass spectroscopy

A
  • used to identify unknown compounds, determine concentrations of known substances the molecular structure and chemical composition of organic and inorganic material
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107
Q

What are the steps of Mass spectroscopy?

A
  1. Atomization
  2. Conversion of a substantial fraction of atoms formed in step 1 to a stream of ions
  3. Separation of the ions formed in the second step on the basis of their mass-to-charge ratio (m/z)
    —> m is the mass of the ion is atomic mass units and z is its charge
  4. Counting the number of ions of each type or measuring current produced when the ions formed from the samples strike a transducer
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108
Q

Describe mass-to-charge ratio

A
  • measurement commonly used in MS
  • obtained by dividing the atomic or molecular mass of an ion by the number of charges that ion bears
  • often shortened to the more convenient term mass
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109
Q

What are the 3 components of mass spectrometers?

A
  • ion source
    1. Electrospray ionization (ESI)
    2. Matrix-associated laser desorption ionization (MALDI)
    3. Surface-enhanced laser desorption ionization (SELDI)
  • mass analyzer
  • ion detector
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110
Q

What are the 5 types of mass analyzers?

A
  1. ESI-QqQ (triple quadrupole)
  2. ESI-QIT (quadrupole ion trap)
  3. MALDI-ToF-MS (time of flight)
  4. ESI-QqToF (quadrupole time of flight)
  5. ESI-FTMS (Fourier transforms)
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111
Q

Describe time of flight of mass analyzers

A
  • consists of a metal flight tube
  • m/z ratios of the ions are determined by accurately and precisely measuring the time it takes ions to travel from the MALDI or SELDI sources to the detector
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112
Q

Describe scintillation counters

A
  • an instrument that detects scintillations using a PMT and counts the electrical impulses produced by the scintillations
  • chemical used to convert their energy into light energy are called scintillators
  • PMT detects light either directly or through an internal reflecting fiber optic
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113
Q

What are scintillations?

A
  • are flashes of light that occur when gamma rays or charged particles interact with matter
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114
Q

What are the two types of scintillations methods that exists?

A
  • crystal scintillations
  • liquid scintillations
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115
Q

Describ crystal scintillations counters

A
  • used to detect scintillations created by interaction of gamma particles from radioisotopes with matter
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116
Q

Describe liquid scintillations counters

A
  • sued to detect and count photons that are produced when beta radiation from radioisotopes interacts with matter
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117
Q

Describe Nuclear magnetic resonance (NMR)

A
  • occurs when the nuclei of certain atoms are immersed in a static magnetic field and exposed to a second oscillating magnetic field, the magnetic component of EMR
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118
Q

What are the basic components of NMR spectrometer?

A
  • magnet used to separate the nuclear spin energy state
  • transmitter that supplies the radio frequencies (RFs) or irradiating energy
  • sample probe
  • computer
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119
Q

Describe the flow cytometer

A
  • instrument that measures multiple cell parameters and other types of particles as they flow individually in front of light source
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120
Q

What are key features of a flow cytometer

A
  • cells or particles
  • illumination
  • fluidics
  • detector
  • data
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121
Q

Describe illumination of flow cytometry

A
  • laser light
    —> serves as a source of illumination for most flow cytometer
    —< provides intense light in a narrow beam
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122
Q

Describe fluidics of flow cytometry

A
  • the particles need to be suspended in a fluid
    —> decreased the probability that multiple cells will group together at the analysis point
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123
Q

Describe the detector of flow cytometry

A
  • lenses are used to collect the light and focus the beam of radiation onto a photodiode
  • only light the has been refracted or scattered as it strikes will be diverted enough to strike the forward-positioned lens and the photodiode behind it
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124
Q

Describe data of flow cytometry

A
  • all data about each of a group of cell is stored in data files in an array where each cell has the associated output from each detector
  • software packages available will produce histograms and scatter grams of any set of parameter values for the cells in the data file
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125
Q

What are some types of microscale technologies?

A
  • lab-on-a-chip
  • micro machining
  • outdoes
  • biosensors
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126
Q

Describe Lab-on-a-Chip of microscale technologies

A
  • a total microanalysis system (uTAS) incorporating sample preparation, separation, detection, and quantification on a microchip surface
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127
Q

Describe micro machining of microscale technologies

A

Process of fabricating labs-on-a-chip and micro machines

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128
Q

Describe optodes of microscale technologies

A
  • optical sensors
  • used in clinical laboratory instrumentation designed to measure blood gases and electrolytes
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129
Q

Describe Biosensors

A
  • a device with a biologically sensitive coating comprising an antibody, receptor protein or biocatalysts
  • comprises a biologically sensitive material (a biocatalyst) in contact with a suitable transducing system that converts the biochemical signal into an electrical signal
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130
Q

What are biocatalyss of biosensors?

A
  • enzyme
  • multienzyme systems
  • antibodies
  • membrane components
  • organelles
  • bacteria
  • mammalian or plant tissues
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131
Q

What are biocatalysts responsible for?

A
  • for the sensitivity and specificity of the biosensors
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132
Q

What are the types of biosensors used in the laboratories?

A
  • electrochemical
  • conductimetric
  • piezoelectric
  • calorimetric
  • optical
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133
Q

What are the respective transducer systems for electrochemical microscale technologies?

A
  • potentiometric
  • amperometric
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134
Q

What is the respective transducer system for piezoelectric?

A
  • applied using crystals of quartz coated with an adsorbent
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135
Q

What is the respective transducer for calorimetric?

A
  • biological component attach to a heat-sensing transducer or thermistor
  • reaction between these two components generates a specific amount of heat
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136
Q

What is the respective transducer of optical of microscale technologies?

A
  • uses fiber-optic technology to measure the reflected fluorescence light from immobilized chemicals at the ed of small fiber-optic probes
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137
Q

Describe enzyme based biosensors with amperometric detection of microscale technologies

A
  • development of electrodes to measure cholesterol, pyruvate, alanine, and creatinine
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138
Q

Describe enzyme-based biosensors with potentiometric and conductometric detection of microscale technologies

A
  • developed for the measurement of BUN, glucose, creatinine and acetaminophen
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139
Q

Describe enzyme-based biosensors with optical detection of microscale technologies

A
  • used to measure analytes such as glucose, cholesterol and bilirubin
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140
Q

Describe affinity biosensors of microscale technologies

A
  • use binding proteins, antibodies, or oligonucleotide as an immobilized biological recognition element
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141
Q

Describe Point of Care (POC) of biosensor technologies

A
  • any test that is performed at the time at which the test result enables a decision to be made and an action taken that leads to an improved health outcome
  • devices are designed to provide both qualitative and quantitative measurements
  • strips
  • sensors
  • devices should:
    —> be portable
    —> have consumable reagent cartiridges
    —> generate results within minutes
    —> require minimum operating steps
    —> have the capability to perform tests on whole blood specimens
    —> have flexible test menus
    —> contain built-in/integrated calibration and quality control
    —> require ambient temperature storage for reagents
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142
Q

What analytes are measured with reflectance?

A
  • urine and blood chemistries
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143
Q

What analyte is measure with lateral-flow immunoassay?

A
  • infectious disease agents, cardiac markers, human chorionic gonadotropin
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144
Q

What analyte is measured with electrochemistry?

A
  • glucose, pH, blood gases, electrolytes, metabolites
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145
Q

What is analyte is measured by light scattering?

A
  • coagulation
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146
Q

What analyte is measured by immunoturbdity?

A

HbA1c, urine albumin

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147
Q

What analyte is measured by spectrophotometry?

A
  • blood chemistry
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148
Q

What analyte is measured by fluorescence?

A
  • pH, blood gases, electrolytes, metabolites
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149
Q

What analyte is measured by multi wavelength spectrophotometers?

A

Hemoglobin species, bilirubin

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150
Q

What analyte is measured by electric impedance

A
  • complete blood count
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151
Q

What analyte is measured by time-resolved fluorescence?

A
  • cardiac markers, drugs, C-reactive protein
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152
Q

Describe laboratory automation

A
  • main impetus behind automation has been needed to create automated systems capable of reducing or eliminating the manual tasks required to perform analytical procedures
  • use of LIS was a decrease in the expected 5% transcription error rate seen when laboratory results were manually transcribed
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153
Q

What are laboratory demands that drive automation?

A
  • reduction in turnaround time (TAT)
  • medical laboratory staff shortages
  • economic factors
  • less maintenance
  • less down time
  • 24/7 uptime
  • increaesed throughout
  • computer and software technology
  • primary tube sampling
  • increased number of different analytes on one system
  • increased number of different methods on one system,
  • reduced lab errors
  • increaesed in number of specimens
  • improved safety of CLS
  • environmental concerns such as biohazards risks
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154
Q

What are advantages of automating chemical analysis?

A
  • reduced errors
  • reduced cost
  • staff free to run additional tests
  • reduced imprecision
  • reduced TATs
  • reduced safety-risk factors
  • reduced repetitive- stress injuries
  • consistent sample processing
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155
Q

What is specimen throughput of automated analysis?

A
  • number of tests performed per hour
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156
Q

What is discrete testing of automated analysis?

A
  • measures only the test requested on a sample
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157
Q

What is Batch analysis of automated analysis?

A
  • a group of samples is prepared for analysis
  • a single test is performed on each sample in the group
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158
Q

What is Random-access testing of automated analysis?

A
  • measure any specimen by a common to the processing systems
  • analyze the specimen by any available process
    —> in or out of sequence with other specimens
    —> without regard to their initial order
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159
Q

Describe preanalytical stage

A
  • involves primarily sample or specimen processing
  • methods to transport specimens
    —> human carriers or runners
    —> pneumatic-tube delivery systems
    —> electric-track-driven vehicles
    —> mobile robots
    —> conveyors or track systems
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160
Q

What are some examples of sample-processing tasks?

A
  • identify specimens
  • label specimens using bar-code lables
  • sort and route
  • centrifuge sample tubes
  • decap tubes
  • prepare sample aliquots
  • recap, store, retrieve
  • transport
  • detect sample level
  • store and retrieve
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161
Q

Describe automated specimen processing of preanalytical stage

A
  • also known as front-end sample processing
  • represents the most cost-effective automaton strategies for the clinical laboratory
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162
Q

What are two goals of automated specimen processing of preanalytical stage?

A
  1. Minimize non-value-added steps in the laboratory process
  2. Increase available time for value-added steps in the tasks that the CLS performs
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163
Q

What are some specimen handling tasks that can be performed with integrated specimen processing?

A
  • presorting
  • centrifugation
  • volume checks
  • clot decision
  • decapping
  • secondary tube labeling
  • aliquoting
  • destination sorting into analyzer racks
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164
Q

Describe sample introduction for the analytical stage

A
  • automation sampling may be accomplished using several different physical mechanisms
  • in most, analyzers, samples are transferred using a thin, stainless steel probe.
  • ## another feature associated with sampling is the ability of the sampler to detect the presence of a liquid
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165
Q

What is liquid level sensor?

A
  • designed to detect the presence of a sample by measuring the electrical capacitance of the surrounding area
166
Q

What are some tasks included in the analytical stage of laboratory testing?

A
  • sample introduction and transport to cuvette or dilution cup
  • reagent measurements, transport, and introduction to cuvette
  • mixing of sample and reagent
  • incubation
  • detection
  • calculations
  • readout and result reporting
167
Q

Describe reagents of the analytical stage

A
  • most laboratories use bulk reagents
  • chemistry analyzers that use unit test reagents may require some preparation
  • complete inventory is established on a real-time basis within the computer
  • on-board reagent storage compartments are refrigerated to maintain reagent stability
  • correct proportions important for accuracy and precision
  • liquid reagents are aspirated, delivered, and dispensed by pumps or positive- displacement syringes
  • direct tube sampling is offered on new model lines
168
Q

What are automated analyzers categorized as?

A

Open or closed

169
Q

Describe open-reagent analyzer

A
  • reagents other than the manufactures reagents can be used
170
Q

Describe closed-reagent analyzer

A
  • operator can only use the instrument manufactures reagents
171
Q

How do instruments perform mixing?

A
  • magnetic stirring
  • rotating paddles
  • forceful dispensing
  • use of ultrasonic energy
  • vigorous lateral displacement
172
Q

Describe incubation of the analytical stage

A
  • warming of instrument components or solution in automated analyzers
  • must be constant and accurate
  • timing is monitored by the instruments computer system
    —> represents an extremely complex process given the throughout for these systems
173
Q

Describe detection of the analytical stage

A
  • in automated analyzers, absorption spectroscopy remains the principal means of measuring a wide variety of compounds
  • electrochemiluminescent methods have also been incorporated.
174
Q

How do instruments perform incubation?

A
  • circulating water baths
  • peltier-thermoelectric module
175
Q

How do instruments perform detection?

A
  • photometer/spectrophotometer
  • fluorimeters
  • electrochemical
  • luminometer
  • infrared detectors
176
Q

Describe signal processing of postanalytical stage

A
  • involves conversion of an analog signal derived from the detector to a digital signal usable by all communication devices
177
Q

What does data processing by computers include?

A
  • data acquisition
  • calculations
  • monitoring and displaying data
178
Q

Describe computers of postanalytical stage

A
  • have profoundly affected the entire process of automated laboratory instruments
  • provide a means of communication between the analyzer and operator
  • have the ability to be linker to other computers
    —> has drastically improved automation efforts
  • many have on-board trouble shooting capabilities
179
Q

Describe total laboratory automation (TLA)

A
  • refers to combination of pre-analytical, intra-analytical and post-analytical components interconnected together
180
Q

What are advantages of TLA ?

A
  • decrease in labeling errors
  • reduced turnaround times
  • potential reduction in full-time equivalents (FTEs)
181
Q

What are disadvantages of TLA?

A
  • needs for substantial financial investment
  • increased floor space
182
Q

Describe integrated modular system

A
  • provide a more attractive approach for hospital laboratories and physician group laboratories because the systems are smaller, require less initial capital investment, and require less planning
183
Q

Describe workstations

A
  • represents a unique environment within a laboratory facility dedicated to one type of testing
184
Q

Describe work cells

A
  • combination of a specimen manger with instruments or consolidated instruments of chemistry and immunoassay reagents
  • provide a broad spectrum of analytical tests
  • specimen manger
  • modular work cells
185
Q

Describe fully integrated systems

A
  • trend to integrate several modules into one continuous system that will allow the used to assay photometric, immunoassay and electrochemical assays
  • use random-access technology to allow the analysis of several types of chemistry assays
186
Q

What are the options of integrated automated systems?

A
  • instrument connectors
  • middleware
187
Q

Describe instrument connectors

A
  • AU-connector uses intelligent sample management and tube-presorting capabilities
    —> keeps all the analyzes working at full potential
188
Q

Describe middleware

A

Software that allows a laboratory to:
- connect its existing LIS and instrumentation to facilitate automating information
- perform tasks not currently done with the laboratory’s existing hardware and software

189
Q

What are some future trends?

A
  • test menus will continue to increase
  • multiple detectors and platforms will be incorporated into a single automated system
    —> provide users with more flexibility
  • increased interest in proteomics will eventually bring this discipline into the clinical laboratory
190
Q

Describe laboratory information systems (LIS)

A
  • described as a group of microprocessors and computers connected together to provide management and processing of information
  • span all three phases of testing
191
Q

What are some patient demographics?

A
  • patient name
  • sex
  • age/DOB
  • patient number (assigned by health-care facility)
  • referring physician
  • admitting diagnosis
192
Q

What items are in order entry?

A
  • patient identifiers
  • ordering physician
  • test-request time and date
  • test name
  • test priority
  • special instructions pertaining to the request
  • specimen draw time
193
Q

Describe protein

A
  • complex polymers of alpha-amino acids that are produced by living cells in all forms of life
  • each protein is composed of a maximum of 20 different amino acids in varying numbers and sequences
194
Q

What do proteins contain?

A
  • carbon
  • hydrogen
  • oxygen
  • nitrogen
  • some include sulfur
195
Q

What does amino acids contain?

A
  • amino group (NH2)
  • carboxyl group (COOH)
  • hydrogen
  • R group with formula RCH(NH2)COOH
196
Q

Describe protein structure

A
  • structure of amino acids is amphotetic-containing two ionizable sites, a photon-accepting group (NH2) and a proton-donating group (COOH)
  • when both are ionized, the amino acid is called an ampholyte or depolar ion
197
Q

Describe isoelectric point (pI)?

A
  • the pH at which when amino acid or protein has no net charge and the positive charges equal the negative charges
  • At a pH greater that the pi, the protein carries a negative charge and at a pH less than the pi, the protein carries a positive charge
198
Q

Describe peptide bonds of protein structure

A
  • a molecule of water is split between the carbonyl group of one amino acid and the amino group of another and a covalent bond called a peptide bond
  • the end of the protein that has the amino-free group, is called the N-terminal end
  • the opposite end has the carboxyl-free group, is called the C-terminal end.
199
Q

Describe primary structure

A
  • the sequence of amino acids in the polypeptide chain-the identity and specific order of the amino acids
200
Q

Describe secondary structure

A
  • determined by the interaction of adjacent amino acids
  • three-possible conformations are the alpha-helix, beta-pleated sheets, and random coils
201
Q

Describe tertiary structure

A
  • the way in which the chain folds back upon itself to form a 3D structure
  • these are mainly interactions of amino acids with the R-groups of more distant amino acids
  • determines the chemical and physical properties of the protein
202
Q

Describe the quaternary structure

A
  • the arrangement of two or more polypeptide chains to form a protein
  • only proteins with more than one polypeptide chain have this,
203
Q

Describe denaturation

A
  • disruption of the bonds holding the secondary, tertiary, or quaternary structures together
  • can occur as a result of heat, changes in pH, mechanical forces, exposure to chemicals (solvents, detergents, metals) and exposure to ultraviolet light
204
Q

Describe protein metabolism

A
  • digestion of dietary proteins by proteolytic enzymes
    —> originates in the GI tract
  • liver and other organs utilize the amino acid pools to synthesize the body’s protein
205
Q

Where are amino acids filtered in through the kidneys?

A
  • renal glomeruli
    —> subsequently reabsorbed by the renal tubules
206
Q

Describe protein synthesis

A
  • most plasma proteins are synthesized in the liver and secreted into circulation by the hepatocytes
  • double-stranded DNA molecule unfolds
    —> one strand serves as a template for the messenger RNA (mRNA)
  • code is carried by the mRNA from nucleus to cytoplasm
    —> attaches to a ribosome receptor protein
  • amino acid linked to transfer (tRNA) that corresponds to the specific codon is carried to the ribosome ad is attached to the matching codon
  • Next amino acid in the sequence is added
  • cycle repeats itself until the protein is completed
207
Q

What are the BASIC functions of proteins?

A
  • maintenance of water distribution between cells and tissue
    —> when protein levels are decreased, the osmotic pressure is also decreased
  • coagulation proteins are important in maintenance of hemostasis
  • many proteins function as transport vehicles to move various ligands to where they are needed or stored
  • structural support (collagen, Keratin)
  • enzymes
  • peptide hormones, insulin
  • hemoglobin
  • antibodies
208
Q

What are examples of tranport molecules (proteins)?

A
  • transferrin- Fe+3
  • Albumin-bilirubin
  • thyroid binding globulins
  • hormones
209
Q

Describe Aminoacidopathies

A
  • inherited disorders of amino acid metabolism
210
Q

What are some aminoacidopathies?

A
  • alkaptonuria
  • cystinuria
  • maple syrup urine disease
  • phenylketonuria
211
Q

Describe Alkaptonuria

A
  • rare inherited disease involving the homogentistic acid oxidase (HGO)
  • leads to a buildup of homogetistic acid (HGA) in the tissues of the body
  • autosomal recessive condition
  • ochronotic
212
Q

What is Ochronotic?

A
  • darkening of the tissues of the body because of excess homogentisic acid
213
Q

Describe the cystinuria

A
  • defect in the amino acid transport system
  • is somewhat insoluble, which results in precipitation in the renal tubules, formation of urinary calculi
214
Q

Describe Maple Syrup Disease

A
  • named for characteristics maple syrup or burnt sugar odor of the urine
  • caused by the absence or very low levels of the branched-chain enzyme alpha-ketoacid decarboxylase comple
    —> results in abnormal metabolism of 3 essential amino acids: leucine, isoleucine, and valine
  • treatment involves a special, very controlled diet required careful monitoring of protein intake
215
Q

Describe Phenylketonuria

A
  • inborn error of metabolism
    —> results in the inability to metabolize the essential amino acid phenylalanine
  • autosomal recessive trait
  • pregnant women known to be carriers of PKU gene or definitely carrying a PKU fetus should also be maintained on a phenylalanine-restricted diet from conception to birth
  • elevated phenylalanine levels are toxic to developing brain tissue and negatively impact brain function
216
Q

What are the 2 main group of proteins?

A
  1. Albumin
  2. Globulin
217
Q

What are the 4 types of globulins?

A
  1. Alpha1-globulins
  2. Alpha2-globulins
  3. Beta- globulins
  4. Y-globulins
218
Q

Describe prealbumin/transthyretin

A
  • TTR binds with thyroxine and triiodothyronine (thyroid hormones) and retinol (vitamin A)
219
Q

What is the main clinical significance of prealbumin?

A
  • role as a sensitive marker of poor nutritional status such as protein-energy malnutrition (PEM)
220
Q

Describe decreased prealbumin

A
  • indicates dietary intake of protein is not adequate
  • results in decreased synthesis for prealbumin by the liver.
221
Q

What disorders are related to decreased albumin?

A
  • acute inflammatory response (acute phase reactant, APR)
  • liver disease
  • Nephrotic syndrome
  • other protein- losing renal diseases
222
Q

Describe albumin

A
  • synthesized in the liver
  • comprises approximately 60% of total serum protein
  • chief biological function is to maintain plasma colloidal osmotic pressure (COP)
  • another function is to transport and store a wide variety of ligands
223
Q

Describe hypoalbuminemia

A
  • decreased albumin levels
  • most common cause is increased catabolism due to tissue damage and inflammation
  • impaired or decreased synthesis
  • increased loss of protein
224
Q

Describe hyperalbuminemia

A
  • little diagnostic significance except in dehydration
  • increase is usually artifactual due to a decrease in plasma volume
225
Q

What are functions of albumin?

A

** Maintain plasma colloidal osmotic pressure
- bind and transport a wife variety of ligands
- serve as an endogenous source of of amino acid
- acid base balance
- pro- and anti-coagulatory effects

226
Q

What are the disorders associated with increased loss of protein?

A
  • Nephrotic syndrome
  • Chronic glomerulonephritis
  • Diabetes mellitus/diabetic nephropathy
  • acute viral gastroenteritis
227
Q

Describe antitrypsin a1 (AAT)

A
  • Antitrypsin a1 (AAT) is the major a1-globulin, makes up 90% of a1- proteins
  • it is an acute phase reactant (APR) with antiprotease activity resulting in the neutralization of leukocyte elastase and collagenase
  • AAT deficiency is one of the most common genetically lethal disease is Caucasians (1:4000)
228
Q

What disorders are associated with AAT deficiency?

A
  • emphysema in absence of smoking
  • juvenile hepatic cirrhosis
    —> AAT is synthesized by the hepatocytes but not released
229
Q

Describe a1-glycoprotein (Orosomucoid)

A
  • AAG is the major glycoprotein increased during inflammation, an APR
  • Elevated level are found in RA, cancer, pneumonia, and other conditions resulting in an APR
230
Q

Describe alpha-fetoprotein (AFP)

A
  • a1 globulin
  • principle fetal protein (albumin-like protein) in maternal serum
  • used to screen for the antenatal diagnosis of neural tube defects including spina bifida and anencephaly
  • can be used as tumor marker
231
Q

What is AFP decreased in?

A
  • Down’s syndrome
  • trisomy 18
232
Q

Describe haptoglobin (Hp)

A
  • a2- globulins
  • an acute phase reactant that binds free hemoglobin in plasma
  • prevents loss of hemoglobin and its iron through the renal glomeruli
  • another role is control of local inflammatory response through a number of processes
  • APR that is synthesized late and is weak reacting
233
Q

What is the most sensitive indicator of intrvascular hemolysis, in transfusion reactions, and certian hemolytic disorders?

A

Depletion

234
Q

What conditions is haptoglobin increased in?

A
  • inflammation
  • infection
  • tissue necrosis
  • malignancy
235
Q

Describe ceruloplasmin (Cp)

A
  • a2-globulins
  • principal copper (Cu)-containing protein in plasma containing 95% of the total serum copper. Copper is very toxic to cells in high concentrations
236
Q

Where is the primary storage site of ceruloplasmin?

A
  • liver
237
Q

Where is the principal site of excretions of ceruloplasmin?

A

Biliary tract

238
Q

Describe Wilson’s disease

A
  • rare autosomal recessive trait where Cp levels are reduced and the dialyzable Cu concentration is increased
  • Cp is an APR that increases late in the condition
239
Q

What can excessive accumulations of Cu in the liver, kidney, and brain lead to?

A
  • degenerative cirrhosis
  • chronic active hepatitis
  • renal tubular acidosis
  • Neuorlogical damage (clumsiness, tremors)
240
Q

What does Cu deposits in the eyes lead?

A
  • results in characteristic Kaiser-Fleischer rings, pigmented rings at the outer margin
241
Q

Describe a2-macroglobulin (AMG)

A
  • one of the largest plasma proteins
  • in nephrotic syndrome, AMG is increased up to 10 times normal because it is retained while smaller proteins are excreted in the urine
  • elevated in liver disease and estrogen
    —> slightly increased in diabetes mellitus
242
Q

Describe transferrin (TRF)

A
  • major component of Beta-globulins
  • principal plasma protein for transport of iron (Fe+3 - ferric ion) to storage sites, whee it is bound to apoferritin and stored as ferritin
  • a negative APR
243
Q

What is important in differential diagnosis of anemias and monitoring the treatment of iron deficiency anemia?

A

Beta-globulin

244
Q

What is commonly used indicator of iron overload-screen for hemochromatosis?

A

Beta-globulins

245
Q

Describe hemopexin

A
  • beta- globulins
  • removes heme from circulation
  • when RBC are destroyed, hemopexin transports heme to the liver, where it is catabolized by the reticuloendothelial system
  • increased level are found in pregnancy and in diabetes mellitus
246
Q

Describe Beta-lipoprotein

A
  • Beta- globulins
  • classified as low-density lipoproteins (LDLs)
    —> transport the majority of cholesterol in the body from the liver to the tissues
  • high levels of LDLs are a risk factor atherosclerosis and heart disease
247
Q

Describe Beta2-microglobulin (BMG)

A
  • low molecular weight protein
  • comprises the common light chain of class I MHC antigens found in all nucleated cells
248
Q

What is increased BMG associated with?

A
  • renal failure
  • inflammation
  • neoplasms, especially the ones associated with B-lymphocytes
249
Q

Describe C- reactive protien (CRP)

A
  • beta-globulin
  • an APR and a non specific indicator of bacterial or viral infection, inflammation and tissue injury or necrosis
  • reacts with proteins present in many bacteria, fungi and protozoal parasites
  • one of the first APRs discovered and one of the most sensitive
250
Q

When does CRP levels rise dramatically?

A

Following:
- myocardial infarction
- trauma
- psychological or physical stress
- infection
- inflammation
- surgery
- various cancers

251
Q

What is valuable in diagnosing bacterial infections and in differentiating between bacterial and viral infections?

A

CRP

252
Q

Describe Y-globulin (gamma)

A
  • immunoglobulins or humoral antibodies
  • each immunoglobulin (Ig) molecule consists of two or more basic units consisting of two identical heavy (H) chains and two identical light chains (L)
253
Q

Describe IgM

A
  • largest Ig with a molecular weight of 900,000 for 5-10% of total Igs
  • first produced during in an immune response
  • primary response
254
Q

Describe IgG

A
  • has a molecular weight of 150,000
  • most abundant Ig in serum (70–75%)
  • IgG antibodies are produced in response to the antigens of most bacteria and viruses
255
Q

Describe IgA

A
  • has a molecular weight of 160,000
  • comprises 10-15% of Ig
  • secretory IgA, a dimer, is found in secretions including tears, sweat, saliva, and milk s well as GI and bronchial secretions
256
Q

Describe IgD

A
  • molecular weight of 184,000
  • makes up 61% of serum Igs
  • primary function is unknown
257
Q

Describe IgE

A
  • has molecular wight of 180,000
  • concentrations are very low (0.3 ug/mg)
  • produced in allergic reactions, urticaria, hay fever, and asthma
258
Q

Describe hyperproteinemia

A
  • associated with a positive nitrogen balance
    — dietary nitrogen intake is greater than the excretion or loss of nitrogen, which occurs mainly in the urine
    —> usually occurs as a result of hemoconcentration or dehydration
259
Q

Describe Hypoproteinemia

A
  • causes a negative nitrogen balance
    —> excretion of nitrogen exceed intake or synthesis of protein
  • most common cause is an increase in plasma water volume, or hemodilution
  • relative hypoproteinemia
260
Q

What are some causes of hypoproteinemia?

A
  • increase increase in plasma water volume (hemodilution)
  • water intoxication
  • salt-retention syndromes
  • massive IV infusions
  • volume expanders
  • increase in protein loss (kidneys, GI tract, and skin)
  • Nephrotic syndrome
  • blood loss after trauma
  • burn patients
  • trauma
  • decreased synthesis
  • liver disease
  • immunodeficiency disorders
261
Q

What are some total protein methodologies?

A
  • biuret
  • refractometry
  • dye-binding method
  • reference range
262
Q

Describe Biuret

A
  • based on presence of peptide bonds found in all proteins
  • when a solution of protein is treated with Cupric (Cu+2) divalent ions in a moderately alkaline medium, a violet-colored chelate, which absorbs light at 540 nm, is formed between the cupric ion and carbonyl oxygen and the amide nitrogen atoms of the peptide bond
263
Q

Describe the biuret reagent

A
  • sodium potassium tartrate
    —> complexed with cupric ions to prevent their precipitation in alkaline solution
  • copper sulfate: major reactant providing the Cu+2 ions
  • potassium iodide: antioxidant that stabalizes the cupric ions
  • NaOH: provides the alkaline pH
264
Q

Describe refractometry of total protein

A
  • used for rapid, approximate measure of total serum protein concentration within the range of 3.5-10 g/dL
  • in plasma, the major solute protein is diluted in water and the refractive index of the solution increases in proportion to the concentration of the solute protein
265
Q

Describe Dye-binding method

A
  • Coomassie Blue G-250, is dissolved in an acidic solution, causing it to absorb at 465 nm
  • the dye, which is negatively charged, binds to the positively charged protein molecule, the absorbance undergoes a shift to 595 nm
    —> used to determine the protein concentration
266
Q

Describe references range

A
  • the serum protein in healthy, ambulatory adults in 6.0-8.3 g/dL
  • a physiological decrease of approximately 0.5 g/dL occurs in bed-ridden patients
267
Q

Describe A/G ratio

A
  • globulin concentration can be calculated by subtracting the albumin from total protein
  • the A/G ratio can then be determined by dividing the albumin concentration by the calculated globulin
268
Q

What is the equation of A/G ratio?

A

Globulin = total protein (g/dL) - albumin (g/dL)

269
Q

Describe urinary proteins

A
  • originate mostly form the blood and filtration through the renal glomeruli
  • proteins in the urine have been filtered by the glomeruli and have not been reabsorbed by the renal tubules
270
Q

What is the most common method of screening for urinary protein?

A
  • urine reagent test strips
    —> indicator tetrabromphenol blue, at a pH of 3.0, is yellow in the absence of protein
    —> turns green and finally blue as the concentration of protein increases
271
Q

Describe cerebrospinal fluid protein

A
  • CSF is a clear, colorless fluid that contains small amounts of glucose and protein
  • reference range is 15-45 mg/dL
272
Q

What are increased levels of CSF proteins associated with?

A
  • various types of meningitis
  • encephalitis
  • subarachnoid hemorrhage
  • multiple sclerosis
  • Gillian-Barre syndrome
  • brain abscesses
273
Q

Describe albumin methodologies

A
  • based on binding of albumin with anionic dyes
    —> Bromcresol green (BCG)
    — Bromsresol purple (BCP)
  • reference range for albumin 3.4-5.g/dL or 34-50 g/dL
274
Q

What are the 4 requirements of dye binding methods of albumin?

A
  1. Specific binding of the dye to albumin in the presence of serum or plasma proteins
  2. High binding affinity between the dye and albumin
  3. Substantial shift in the absorption wavelength of the dye in the bound form
  4. Absorption maximum for the bound form at a wavelength distinct from those where bilirubin and hemoglobin, the main interfering chromogens, can interfere
275
Q

Describe protein electrophoresis

A
  • migration of charged solutes or particles in a liquid medium under the influence of an electrical field
  • proteins are ampholytes or zwitterions and can move toward the anode or cathode, depending on the Charge
  • performed on serum to avoid complication of the fibrinogen band in the beta-gamma region
  • after electrophoresis, the bands are fixed by immersing the strip in an acid medium
276
Q

Describe a normal serum protein electrophoresis (SPE)

A
  • has five bands
  • % distribution X total protein = g/dL
277
Q

Describe fusion of B-Y bands or bridging

A
  • results of fast-moving Y-globulins that prevent resolution of B- and Y-globulins
278
Q

What is the most common cause of B-Y bridging?

A
  • cirrhosis
    —> can also be found in chronic infections and autoimmune or collagen disorders
279
Q

Describe nephrotic syndrome and abnormal protein electrophoresis

A
  • characterized by a decrease in albumin and Y-globulin bands in conjunction with an increase in a2-globulins that suggest selective proteinuria
280
Q

Describe APR and abnormal protein electrophoresis

A
  • APR that increase during APR are positive acute phase proteins (AAPs)
  • negative AAPs are albumin, transferrin, and transthyretin (prealbumin)
281
Q

What conditions are associated with increased APR?

A
  • infection
  • tumor growth or malignancy
  • RA
  • Hepatitis
  • Surgery
  • trauma
  • burn
  • myocardial infarction
282
Q

Describe multiple myeloma

A
  • cancer of the plasma cells
  • plasma cells produce immunoglobulins that normally protect us from infection but in multiple myeloma these are nonfunctional and are called paraproteins
  • increased in the Y globulin
283
Q

What is the first band of protein electrophoresis?

A

Albumin

284
Q

What is the second band of protein electrophoresis called and what does it consist of?

A

Alpha(1)
—> a1 anti-trypsin
—> a1 acid glycoprotein

285
Q

What is the third band of protein electrophoresis and what does it consist of?

A
  • Alpha(2)
    —> a2-macroglobulin
    —> haptoglonulin
286
Q

What is the fourth band of protein electrophoresis and what does it consist of?

A

Beta
- Hemopexin
- transferrin
- beta-lipoprotein
- complement C3

287
Q

What is the fifth band of protein electrophoresis and does it consist of?

A
  • gamma
    —> IgA
    —> IgM
    —> IgG
288
Q

Describe the electrophoresis band pattern of nephrotic syndrome

A

Decreased:
- albumin, a1, B, and y globulin
Increased:
- a2 globulins

289
Q

Describe the electrophoresis band of APR

A

Increaed:
- a1
- a2

290
Q

Describe the electrophoresis bands of multiple myeloma

A

Increase in y globulin-M spike

291
Q

Describe the kidneys importance

A
  • play a vital role in maintaining levels of many substances in the human body, retaining critical components and eliminating what is not essential
292
Q

Describe renal function tests

A
  • included in chemistry screening profiles to test for renal disease, water balance, and acid-base disorders
293
Q

What organs are in the urinary system?

A
  • two kidneys
  • two uterers
  • bladder
  • urethra
294
Q

Describe the kidney structure

A
  • divided into two distinct areas
    1. The outer layer, or cortex
    2. The inner layer, or medulla
  • each kidney contains approximately one to 1.5 million nephrons, the functional unit of the kidney
295
Q

Describe renal blood flow

A
  • vital to renal function
  • supplied by renal artery
  • enters the nephrons through the afferent arteriole-
  • flows through glomerulus into efferent arteriole
  • blood is filtered in the glomerulus
  • filtrate flows through the proximal convoluted tubule (PCT)
296
Q

What is the Renal blood flow?

A
  1. Renal artery
  2. Afferent arteriole
  3. Glomerulus
  4. Efferent arteriole
  5. Peritubular capillaries
  6. Vasa recta
  7. Renal vein
297
Q

What are 3 major renal functions?

A
  1. Glomerular filtration
  2. Tubular reabsorption
  3. Tubular secretion
298
Q

Describe glomerular filtration

A
  • enhanced by a number of factors
  • pressure in the glomerular capillaries is high because of the difference in size between the Afferent and efferent arterioles
  • basement membrane is negatively charged and large, negatively charged molecules (protein) are repelled
299
Q

Describe tubular reabsorption

A
  • active transport
  • renal threshold
  • passive transport
300
Q

Describe active transport of tubular reabsorption

A
  • substance to be reabsorbed must be combined with a carrier protein contained in the membranes of the renal tubular cells
301
Q

Describe renal threshold of tubular reabsorption

A
  • concentration above which the substance cannot be totally reabsorbed and is excreted in the urine
302
Q

Describe passive transport of tubular reabsorption

A
  • requires no energy
  • characterized by movement of substance from an area of high concentration to one of lower concentration
  • water and urea are always reabsorbed through passive transport
303
Q

Describe tubular secretion

A
  • passage of substances from the Peritubular capillaries into the tubular filtrate
304
Q

What are the 2 major functions of tubular secretion?

A
  • elimination of waste products not filtered by the glomerulus
  • regulation of acid-base balance in the Body through secretion of 90% of the hydrogen ions excreted by the kidney
305
Q

Describe Nonprotein Nitrogen (NPN)

A

Comprises the products of catabolism of proteins and nucleic acids, which contain nitrogen but are not part of a protein molecule

306
Q

What is the NPN of blood urea nitrogen (BUN)?

A

45%

307
Q

What is the NPN of amino acids?

A

20%

308
Q

What is the NPN of uric acid?

A

20%

309
Q

What is the NPN of creatinine?

A

5%

310
Q

What is the NPN of creatine?

A

1-2%

311
Q

What is the NPN of ammonia?

A

0.2%

312
Q

Describe Blood urea nitrogen (BUN)

A
  • major nitrogen-containing metabolic product of protein catabolism in humans
313
Q

What is BUN formed from?

A
  • exogenous protein: protein in diet
  • endogenous protein: protein from the breakdown of cells in the body
314
Q

Describe the direct relationship between urea and the glomerular filtration rate (GFR)

A
  • in a patient with a normal to increased GFR, approximately 40% of the BUN is reabsorbed and 60% is excreted
  • in a well-hydrated patient, more BUN is excreted, resulting in a lower serum BUN
  • in a dehydrated patient, 70% of the BUN is increased and urine BUN is decreased
315
Q

What are the 3 variables that BUN is dependent on?

A
  • urea concentration
  • glomerular filtration rate (GFR)
  • level of hydration
316
Q

What are clinical significances of BUN?

A
  • azotemia
    —> an increased blood urea and other NPN compounds
  • uremia
    — an increased urea/BUN
317
Q

What are the categories of azotemia?

A
  • prerenal
  • renal
  • postrenal
318
Q

Describe prerenal azotemia

A
  • decreased renal blood flow
  • increased protein catabolism
319
Q

What would deceased renal blood flow lead to?

A
  • congestive heart failure
  • dehydration
  • shock (from blood loss)
  • advanced cirrhosis
  • septic states
320
Q

What does increased protein catabolism lead to?

A
  • muscle wasting (starvation)
  • GI hemorrhage
  • stress
  • steroids
  • uncontrolled diabetes mellitus
  • high fever
321
Q

What does renal azotemia lead to?

A
  • uremia
  • acute kidney injury
  • glomerulonephritis
  • nephrotic syndrome
  • acute renal failure
322
Q

What does postrenal azotemia lead to
?

A
  • tumors of the bladder or prostate gland
  • prostatic hypertrophy
  • gynecologic tumors
  • nephrolithiasis
  • severe infections
323
Q

Describe the BUN: creatinine (BUN:CR) ratio

A
  • the normal ratio is between 12:0 to 20:1
  • in renal disease, BUN and CR are both elevated proportionally
  • the ratio will fall within the normal range
  • a high ratio >20:1 to 30:1with a high BUN and a normal or only slightly elevated CR is associated with prerenal azotemia
  • high ratios with an elevated CR suggest postrenal obstruction (azotemia) or prerenal azotemia in addition to renal disease
324
Q

What are BUN methodologies?

A
  • urease
  • berthelot’s reaction
  • Nesslers reaction
  • glutamate dehydrogenase (GLDH)
  • diacetyl or fearon reaction
325
Q

What does urease look like?

A

Urea + 2H2O —(urease)—> 2NH4 + CO3

326
Q

Describe Bethelot’s reaction

A
  • the ammonium ion is reacted with phenol and hypochlorite in an alkaline medium to form indophenol blue, the chromagen which is measured
  • NH4 + 5 NaOCl + phenol —(NaOH)—> indophenol blue + 5NaCl + 5H2O
327
Q

Describe Nesslers reaction

A
  • the addition of a double iodide compound (2HgI2 + 2KI) results in the formation of a yellow to orange brown compound with NH4+

2HgI2 + 2KI + NH4 —> NH2HG2I3 + 4KI + NH4I

328
Q

Describe glutamate dehydrogenase (GLDH)

A
  • is most commonly used.
  • the disappearance of NADPH is measure as a decrease in absorbance as NADPH is oxidized to NAD+

NH4 + 2-oxoglutarate + NADH —(glutamate dehydrogenase)—> NAD + glutamate + H2O

329
Q

Describe diacetyl or fearon reaction

A
  • colorimetric reaction based on the condensation of diacetyl with urea to form the chromogen diazine

Urea + diacetyl + H2O —(H+ strong acid)—> Diazine + 2H2O

330
Q

What is the reference range for BUN?

A

7-18 mg/dL

331
Q

What is the reference range for BUN on a. 24hr urine?

A

12-20 g/24h

332
Q

What type of diet increases BUN?

A

High protein

333
Q

What value of BUN is considered dehydrated?

A

<8 mg/dL

334
Q

What is the range of BUN that signifies impairment of glomerular filtration rate?

A

50-150 mg/dL

335
Q

What value of BUN. Is evidence of severe renal impairment?

A

150-200 mg/dL

336
Q

Describe conversion factor for BUN

A
  • calculated using the molecular weight of BUN and nitrogen
  • BUN mw (60)
  • nitrogen (28)
337
Q

How to convert from urea to urea nitrogen?

A

Divide the mw of nitrogen by the mw of urea

28/60 for a factor of 0.467

338
Q

How to convert urea nitrogen to urea?

A

(60/28) is factor 2.14

339
Q

What amino acids synthesize creatinine in the liver?

A
  • arginine
  • glyicine
  • methionine
340
Q

Describe creatinine

A
  • readily filtered by the glomeruli and does not undergo and significant tubular reabsorption
  • waste product derived from creatine and creatine phosphatase

Phosphocreatine + ADP —(creatine kinase)—> creatine + ATP

Creatine —> creatinine + H2O

341
Q

Constancy of endogenous creatinine production is proportional to what?

A
  • the muscle mass of the individual and it is released into the body fluids at a constant rate
342
Q

What are the 3 main variables that affect creatinine levels?

A
  • relative muscle mass
  • creatine turnover
  • renal function
343
Q

Describe the clinical significance of creatinine

A
  • creatinine is primarily an index of renal function
    —> measures that glomerular filtration rate (GFR)
  • increased serum creatinine is present when the formation or excretion of urine is impaired due to prerenal, renal or postrenal causes
  • creatinine levels in urine can be used to detect if a urine has been diluted
  • creatinine and BUN levels can be used to identify a fluid as urine
344
Q

What are the reference ranges of creatinine?

A

Men: 0.9-1.2 mg/dL
Women: 0.6-1.1 mg/dL (because lower muscle mass)

  • decrease with age beginning in the fifth decade
345
Q

What are creatinine methodologies?

A
  • Jaffe reaction
  • a kinetic method
  • creatininase (creatinine amidohydrolase)
    —> followed by creatinase, sarcosine, oxidase and peroxidase
  • creatinase
    —> second enzymatic procedure also fuses creatinase followed by creatine kinases, pyruvate kinase (PK), and lactate dehydrogenase (LD)
    —> creatinase —>CK—>PK—>LD
346
Q

Describe uric acid

A
  • the major product of purine (adenine and guanine) catabolism in man and high primates
    —> produced in the liver from xanthine by the action of the enzyme xanthine oxidase

Xanthine —(xanthine oxidase)—> uric acid

347
Q

What is uric acid formed from?

A
  • exogenous nucleotides (dietary)
  • endogenous nucleotides (cells breaking down and being replaced
348
Q

What are clinical significance of uric acid?

A
  • Hyperuricemia
    — a serum UA concentration of >7.0 mg/dL
349
Q

What are causes of hyperuricemia?

A
  • increased dietary intake
  • overproduction of uric acid
  • underexcretion of uric acid
  • specific enzyme defects
350
Q

What are the reference ranges for uric acid?

A

Male: 3.5-7.2 mg/dL
Female: 2.6-6.0 mg/dL

351
Q

What is the urinary filtrate flow?

A
  1. Bowman’s capsule
  2. PCT (proximal)
  3. Descending loop of Henle
  4. Ascending loop of Henle
  5. DCT (distal)
  6. Collecting duct
  7. Renal calyces
  8. Ureter
  9. Bladder
  10. Urethra
352
Q

What is associated with primary hyperuricemia?

A

Gout
Idiopathic

353
Q

What is associated with secondary hyperuricemia?

A
  • cytotoxic chemotherapy
  • radiation therapy
  • malignancy
  • acute or chronic renal disease, renal failure
  • increase tissue catabolism/starvation
  • glycogen storage disease
  • high purine diet
  • ethanol abuse
  • toxemia of pregnancy
  • severe exercise
  • poisons (lead)
  • drug therapy (diuretics,barbiturates)
  • Lesch-Nyhan syndrome
354
Q

Describe gout of uric acid

A
  • inborn error of metabolism
  • predominantly in men 30 to 50 years of age
  • 7 time more common in men than women
355
Q

What are symptoms of gout?

A
  • arthritis (pain, inflammation of the joints)
  • Nephropathy
  • nephrolithiasis
356
Q

What triggers gout attacks?

A
  • alcohol
  • high-protein diets
  • stress
  • acute infection
  • surgery
  • certain medications
357
Q

What are uric acid methodologies?

A
  • phosphotungstic acid
  • sodium carbonate
  • uricase
358
Q

Describe phosphotungstic acid of uric acid methodologies

A

Measures the development of a blue color (tungsten blue) as phosphotungstic acid (PTA) is reduced by uric acid in an alkaline medium

359
Q

Describe sodium carbonate of uric acid methodologies

A

Added to maintain the alkaline pH

Uric acid + phosphotungstic acid —(Na2CO3)—> Allantoin + CO2 + Tungsten blue

360
Q

Describe uricase of uric acid methodologies

A
  • catalyzes the oxidation of uric cid to allantoin
  • the decrease in absorbance at 293 nm, which is a peak absorbance for uric acid and one at which allantoin does not absorb
  • peroxidase and a dye (4-aminoantipyrene) is a second modification and the most common automated method
361
Q

Describe renal clearance test

A
  • the rate at which the kidneys remove a substance from the plasma or blood
  • quantitative expression of the rate at which a substance is excreted by the kidneys in relation to the concentration of the same substance in the plasma usually expressed as mL cleared per minute
362
Q

Describe creatinine clearance test

A
  • creatinine is a very good indicator of glomerular filtration rate for 3 reasons
    —> freely filtered by the glomeruli
    —> not reabsorbed by the tubules to a significant extent
    —> released into the plasma at a constant rate, resulting in constant plasma levels over 24 hours
363
Q

How is creatinine clearance calculated?

A
  • CrCl is calculated using the serum and urine creatinine levels and the urine volume

Clearance(x) = (U x V)/P

U = urine concentration in mg/dL
P = plasma concentration in mg/dL
V = urine flow in mL/minute (1440 min/24hr)

364
Q

Describe creatinine clearance correction

A
  • creatinine clearance has to be corrected to an adult body surface area (BAS) of 1.73 m2
  • espcecially important from small or pediatric patients and obese patients
  • Dubois formula

SA (surface area in m2) = W(kg)^0.425 x H(cm)^0.725 x 0.007184
* addd to CrCl equation

[(U x V)/P] x (1.73 m2)/BSA m2 (normalization factor)

365
Q

What test has the largest source of error due to incomplete urine collection?

A

Creatinine clearance test

366
Q

What are the reference range of creatinine

A

Males: 97-137 mL/minute
Females: 88-128 mL/minute

367
Q

Describe eGFR clearance tests

A
  • use of an estimating or prediction equation to estimate glomerular filtration rate from the serum creatinine level in patients with chronic renal disease and those at risk for CKD
  • original modification of diet in renal disease (MDRD) study equation
    —> in pateints 18 years of age and older, the MDRD equation is the best means currently available to use creatinine values as a measure of renal function
368
Q

Describe protein:creatinine ratio clearance test

A
  • normal protein excretion is <100-150 mg/24h
  • creatinine excretion is fairly constant at 12-20 mg of creatinine per kilogram of body weight per day
  • normal protein: creatinine ratio is <0.1
    —> 100-150 mg protein/1000-1500 mg creatinine
369
Q

Describe insulin clearance test

A
  • an endogenous, naturally occurring polysaccharide found in artichokes
  • insulin in injected and measured in serum and urine over three hours
  • no easily performed test for insulin measurement
  • difficult to meet the criteria for accurate testing
370
Q

Describe cystatin C clearance test

A
  • single-chained, nonglycoslated, low-molecular-weight protein synthesized by all nucleated cells
  • freely filtered by the glomeruli and catabolized in the proximal convoluted tubules
  • produced at a constant rate
  • not affected by muscles mass, diet, race, age, or gender
371
Q

What are screening tests for renal disease?

A
  • serum protein
  • B-microglobulin
  • low-molecular-weight proteins
  • urinalysis
  • microalbumin
372
Q

Describe serum protein screening for renal disease

A
  • severe renal disease is characterized by decrease in total protein, especially the smaller-molecular-weight-proteins such as albumin
  • both serum total protein and albumin levels therefore will be decreased in some renal diseases
373
Q

Describe B-microglobulin screening of renal disease

A
  • BMG
  • small, nonglycosylated protein found on the cell membrane of most nucleated cells
  • present in especially high levels in lymphocytes
  • increased in renal failure
  • used primarily to test for renal tubular function in renal transplant pateints when decreased tubular function indicates early rejection
374
Q

Describe low-molecular-weight proteins screening for renal disease

A
  • a1-microglobulin
  • a2-microglobulin
  • B-trace protein
  • cystatin C
375
Q

Describe urinalysis screening for renal disease

A
  • routine urinalysis may be the first indication of renal disease
  • reagent strip tests provide valuable information regarding renal function
376
Q

Describe protein test of urinalysis

A
  • utilizes tetrabomphenol blue and is based on the “protein error of indicators”
377
Q

What is often the first sign of kidney disease?

A

Proteinuria

378
Q

What is blood or hemoglobin in the urine indicative of?

A

Renal or bladder disease

379
Q

What does presence of leukocytes in urine associated with?

A

Bacterial infection in the bladder or kidney

380
Q

What is nitrite detection used for in urinalysis?

A
  • nitrate-reducing bacteria
381
Q

What is usually the first sign of renal disease?

A
  • albumin in the urine
  • acknowledged to be an independent predictor of nephropathy in diabetes mellitus
382
Q

Describe glomerular disease

A
  • associated primarily with damage to the glomeruli of the renal nephron
  • various renal disease are characterized by distinctive chemistry and urinalysis profiles
383
Q

Describe acute glomerulonephritis (AGN)

A
  • characterized by rapid onset of symptoms that indicate damage to the glomeruli
  • most often associated with children and young adults following a group A streptococcal infection (strep infection)
384
Q

What are the symptoms of AGN?

A
  • rapid onset
  • fever
  • malaise
  • nausea
  • oliguria
  • hematuria
  • proteinuria
385
Q

Describe secondary complications of glomerulonephritis

A
  • edema
    —> especially periorbital, knees, ankles
  • hypertension from mild to moderate
  • electrolyte imbalance (Na+ and K+)
  • Renal function tests are abnormal with elevated BUN and creatinine and decreased GFR
  • as toxicity subsides, the urinalysis and renal function tests return to normal
386
Q

Describe Chronic Glomerulonephritis (CGN)

A
  • associated with end stage of persistent glomerular damage with irreversible loss of renal tissue and chronic and renal failure
387
Q

What are the symptoms of CGN?

A
  • edema
  • fatigue
  • hypertension
  • anemia
  • metabolic acidosis
  • proteinuria
  • decreased urine volume from oligura to Anuria
388
Q

Describe nephrotic syndrome

A
  • may occur as a complication of glomerulonephritis or as a result of circulatory disorders
389
Q

What conditions can nephrotic syndrome be associated with?

A
  • minimal charge nephropathy
  • focal segmental glomerulosclerosis (FGSG)
  • carcinoma
  • drugs
  • infection
390
Q

Describe symptoms of nephrotic syndrome

A
  • Massive proteinuria
  • albuminuria
  • pitting edema
  • hyperlipidemia
  • hypoalbuminemia
391
Q

What are the hallmark sign nephrotic syndrome?

A
  • low albumin and high lipids
392
Q

Describe pyelonephritis

A
  • inflammatory process involving a bacterial infection of the renal tubules by gram-negative bacteria
  • ascending infection
  • usually does not cause permanent damage to the renal tubules
393
Q

What are the negative-gram bacteria found in pyelonephritis?

A
  • escherichia Coli
  • klebsiella
  • proteus
  • enterobacter
394
Q

What are causes or conditions of pyelonephritis?

A
  • incomplete emptying of bladder
  • vesicourelteral reflux
  • diabetes
  • urinary obstruction
  • catheterization
395
Q

Describe chronic pyelonephritis

A

-characterized by permanent scarring of the renal tubules
- can lead to renal failure
- most common cause is vesicoureteral reflux nephropathy

396
Q

What would the urinalysis of a patient with chronic pyelonephritis look like?

A
  • alkaline pH
  • positive leukocyte esterase
  • bacteria (+/-)
  • proteinuria (moderate)
  • decreased specfic gravity
  • granular, waxy cast, broad, WBC, and renal cells casts
  • polyuria
  • nocturia
397
Q

Describe cystitis

A
  • a bladder infection characterized by dysuria
  • more common in females than males
  • can progress to pyelonephritis if untreated or if treatment guidelines have not been adhered to
398
Q

What would a urinalysis of a patient with cystitis look like?

A
  • small protein (<0.5 g/day)
  • hematuria
  • leukocyte esterase and nitrite positive
  • increased WBCs, bacteria, transitional epithelial cells
  • Absence of cellular casts
399
Q

What conditions are associated with chronic kidney disease (CKD)?

A
  • hypertension
  • diabetes
  • autoimmune diseases
  • urinary tract and systemic infections
  • nephrolithiasis
400
Q

Describe the stages of CKD

A

At risk = GFR >90 (no markers of kidney damage)
1 = kidney damage with normal to increased GFR (>90)
2 = kidney damage with mild reduction of GFR (60-89)
3 = moderate reduction of GFR (30-59)
4 = severe reduction of GFR (15-29)
5 = kidney failure (<15 or on dialysis)

401
Q

Descibe renal failure

A
  • acute increase in the serum creatinine level of 25%, or more and GFR 610 mL/min.
  • results from acute tubular necrosis from vasoconstriction, nephrotoxic agents and hemorrhaging
402
Q

What are signs of renal failure?

A
  • decreased urine production
  • oliguria (6400 mL/day)
  • anuria
403
Q

Describe renal calculi

A
  • solid aggregates of chemical or mineral salts formed in the renal tubules, renal pelvis, ureters or bladder
  • can cause ulceration and bleeding
  • more common in males than females
  • 75% calcium oxalate with or without phosphate
  • 15% magnesium ammonium phosphate
  • 6% urate (uric acid)
  • 1-2% cystine
  • 2-3% mixtures
404
Q

What are the four factors that influence the formation of kidney stones?

A
  1. Increased in concentration of chemical salts as a result of dehydration or increase in salts in the diet
  2. Change in urinary pH
  3. Urinary stasis
  4. Presence of a foreign body
405
Q

What are symptoms of renal calculi?

A
  • nausea
  • vomiting
  • intense pain from the kidney, and downward toward the abdomen, genitalia, and legs
406
Q

Describe diabetes mellitus

A
  • some 45% of type 1 diabetes mellitus patients develop nephropathy within 15 - 20 years of diagnosis
  • diabetic nephropathy is diagnosed when a patient with diabetes presents with proteinuria with no evidence of a urinary tract infection
  • diabetes is the leading cause of renal failure
407
Q

Describe dialysis

A
  • dialysis or kidney transplant may be the only treatment options available for patients with acute renal failure or ESRD
  • is a process whereby larger macromolecules are separated from low-molecular-weight compounds by their rate of diffusion through a semipermeable membrane
408
Q

Describe hemolysis (HD)

A
  • synthetic membrane is in a machine outside the body
  • traditional and most common method
  • patients blood minus the toxic products is returned to circulation
  • dialysate contains the waste products is discarded
409
Q

Describe peritoneal dialysis (PD)

A
  • peritoneal wall acts as the dialysis membrane
  • dialysate is introduced and removed through gravity
  • requires continuous (24 hours a day, 7 days a week) treatment
  • not as effective as hemodialysis
410
Q

What must be closely evaluated in dialysis patients?

A
  • well-being
  • cardiovascular risk
  • nutritional status
  • degree of achievable ultrafiltration
411
Q

Describe Urea kinetic modeling (UKM)

A
  • evaluates dialysis patients
  • consider age, sex, presence of diabetes, or cardiovascular disease, and creatinine clearance
  • most widely used method in the assessment of dialysis adequacy
412
Q

Describe complications of dialysis

A
  • patients on dialysis are prone to a number of diseases
    —> 40% show evidence of coronary artery disease
    —> 75% show left ventricular hypertrophy
  • anemia is common in people with kidney disease
  • dialysis patients with ESRD also have poor appetite, and protein metabolism is decreased because of inflammation and chronic acidosis
    —> results in malnutrition

MLT Clinical Chemistry (7 decks)

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