Laboratory Medicine Flashcards Preview

PATHOLOGY > Laboratory Medicine > Flashcards

Flashcards in Laboratory Medicine Deck (94):
1

Anatomic pathology includes

autopsy services, surgical pathology, cytology

2

Autopsy service

infrequent due to costs, imaging procedures, malpractice

3

Virtual autopsy

detailed body scan without dissection (becoming popular)

4

Surgical pathology

specimen collected from surgery must be examined (gross appearance, tissue processing (paraffin) and staining (H&E, special stain)

5

Cytology

pap smear, tissue brushings

6

Should cancer be diagnosed by cytology tissue brushing?

No, cannot see cell arrangement, use biopsy

7

Rembrandt, Dutch painter born in

1606

8

Liffey Swim

annual swim in dublin

9

Rembrandt had what famous painting in 1632

Abduction of Europa (oil-based)

10

Who performs a fine-needle aspiration?

pathologist

11

Pathologist do what procedures

fine-needle biopsy and surgical removal of tissue

12

Clinical pathology includes:

Hematology, transfusion, microbiology, chemistry, immunology, STAT lab, point-of-care testing

13

What type of specimen is used for ON-SITE diagnosis

frozen section

14

Panic value

sufficiently abnormal lab result value that indicates an immediate threat

15

Hematology - CBC

Measures Hgb, RBC count, and MCV; Calculates HCT, MCH, MCHC; WBC, platelets, % of WBCs, and RDW

16

Hematology - CBC with diff

CBC + count of normal/abnormal WBCs, morphology included

17

Hemoglobin is measured

measured from whole blood using CYANOMETHEMOGLOBIN formation

18

Counts of RBC, WBC, and platelets are obtained by

cell counter that measures conductance of cells passing through a small aperture (electrical impulse indicates cell type)

19

WBC population analysis

RBC lysis -> WBC automated flow cytometry (size, granules, shape, etc)

20

Automated flow cytometry

single cell characterization by size, shape, biochemical, or antigenic composition, by a scattering of light beam

21

Forward scatter in flow cytometry

diffraction = cell volume

22

Side scatter in flow cytometry =

refraction = measures internal cellular granularity

23

Pre-analytic phase

decision to perform test, specimen collection, etc

24

Analytic phase

Specimen analyzed

25

Post-analytic phase

report + interpretation and response to result

26

Peripheral blood smear procedure

blood smear, Wright stain, view whole slide (large cells at edge)

27

Blood clotting times - initial screening

PT and PTT

28

PT (prothrombin factor) measures

extrinsic pathway and common pathway factors (thromboplastin + Ca + plasma) [warfarin]

29

PTT (partial thromboplastin time)

evaluates intrinsic pathway and common pathway (partial thromboplastin + activator + Ca + plasma) [heparin]

30

Coagulation factor assay is based on

PT: thromboplastin for factors II, V, VII, and X
PTT: partial thromboplastin for factors VIII, IX, XI, and XII *ONLY patient's plasma contains factors = clotting time

31

2 Sickle cell screening tests

sickling test and solubility test

32

Sickle cell test - sickling test

Blood + reducing agent (to reduce oxyhemoglobin to hemoglobin to accelerate sickling), examined for sickling cells presence

33

Sickle cell test - solubility test

lysed RBCs (saponin): deoxyhemoglobin S is insoluble in phosphate buffer; HbS = crystal formation; HbA is soluble

34

Hgb electrophoresis test

purified RBC hemolysate is separated by electrophoresis; PRINCIPLE for diagnosing hgb abnormalities

35

Blood banking procedure

Collect anti-coagulated whole blood -> spin to isolate RBCs and platelet-rich plasma -> spin to isolate platelets and plasma

36

Plasma contains

Igs, albumin, cryprecipitate (factor VIII, XIII, fibronectin, etc)

37

Cryopoor plasma

plasma without cryprecipitate (factor VIII, XIII, fibronectin, etc)

38

ABO/Rh forward typing tests

detects antigens on patient's RBCs; mix RBC with anti-sera A/B/Rh; agglutination = blood type

39

ABO/Rh reverse typing tests

detects Abs in the patient's plasma; mix patient's plasma with reagent cells-A/B antigen; agglutination = presence of antibody

40

Apheresis

removal of blood, followed by separation of blood components (some components may be returned)

41

RBCs can be stored for

35-42d @ 4C

42

Platelet-rich fraction can be stored for

<5 days @ 25C

43

Therapeutic plasma exchange procedure

blood continuously withdrawn, separated into cellular and plasma, cellular component is mixed with FFP or colloid solution and returned to patient

44

Use for Therapeutic plasma exchange

Guillain Barre: to remove Ab's against self

45

Gram Stain procedure

1. Crystal violet (1m) 2. Iodine (1m) 3. Destain EtOH 4. Counterstain Safranin (1m); rxn, shape, arrangement

46

Plating

plate microbe in culture medium

47

Antimicrobial susceptibility test - disc diffuse method

discs embedded with different antimicrobial agents + suspension of organism; zones of inhibition are measured to determine susceptibility, intermediate, or resistant to antibiotic

48

Antimicrobial susceptibility test - dilution method

determines MIC (minimal inhibitory concentration); increasing dilutions of antimicrobial + agent; MIC = 1st tube which shows NO growth

49

Automated chemical profile includes

total protein, albumin, Ca2+, inorganic phosphate, cholesterol, glucose, creatinine, uric acid, Bilirubin, alkaline phosphatase, lactate dehydrogenase, aspartate aminotransferase (may include more)

50

Complete Chemical Profile

Albumin.
Alkaline Phosphatase.
Alanine Aminotransferase (ALT).
Aspartate Aminotransferase (AST).
Bilirubin (total and direct).
Blood Glucose.
Blood Urea Nitrogen.
Calcium (Ca) in Blood.
Carbon Dioxide (Bicarbonate).
Chloride (Cl).
Cholesterol and Triglycerides Tests.
Creatinine and Creatinine Clearance.
Gamma-Glutamyl Transferase (GGT).
Lactate Dehydrogenase.
Phosphate in Blood.
Potassium (K) in Blood.
Sodium (Na) in Blood.
Total Serum Protein.
Uric Acid in Blood.

51

(alanine aminotransferase) ALT/SGPT indicate pathology in

Liver, heart, skeletal muscle

52

Amylase indicates pathology in

pancreas, salivary gland

53

LDH indicates pathology in

most organs, esp heart, liver, lung, kidney

54

PSA indicate pathology in

prostate

55

LDH1:

heart, kidney, RBCs

56

LDH2/LDH3

lung, lymphocyte, platelets

57

LDH4

some types of leukemia

58

LDH5:

liver, skeletal muscle, neutrophils, prostate

59

What is all enzymes are high?

shock or infectious mononucleosis

60

International unit of enzyme

amount that catalyzes 1 umol of substrate/min under defined conditions

61

Alkaline phosphatase

bone, liver, all tissues

62

GGT/P

Liver, bile duct

63

AST (SGOT)

heart, liver, RBCs, skeletal muscle

64

isozyme

molecular variant of an enzyme or DIFFERENT enzyme that catalyzes the same reaction

65

LDH1 > LDH2 suspect

necrosis (infarction) of heart or kidney or hemolysis

66

High LDH5 suspect

liver and skeletal muscle damage

67

High LDH3 suspect

pulmonary infarct

68

Urinanalysis examines

appearance, specific gravity (density), pH, leukocytes, nitrites, protein, glucose, ketones, urobilinogen, bilirubin, and blood

69

Microscopic analysis of urine

examine sediment: cells, casts, crystals, microorganisms

70

Antinuclear antibody testing tests for

autoimmune disorders such as lupus erythematous, rheumatoid arthritis, and Sjogren Syndrome

71

Antinuclear antibody testing Procedure

patient's serum + Hep2 cells; rinse; + anti-human IgG-fluorescent tag; Fluorescence microscopy detects presence/absence and pattern/titer of fluorescence

72

Immunoassay

any (colorimetric) assay that relies on antigen/antibody complex; used to detect and quantitate proteins, hormones, and amino acids

73

Non-competitive immunoassay (Type I)

Excess antibody + antigen; # of complexes DIRECTLY relates to [antigen]

74

Competitive immunoassay (Type II)

excess antibody + analyte + labeled-analyte; labeled and non-labeled compete; amt of signal from label-bound-antigen INVERSELY relates to [antigen]

75

Flow cytometry is used to diagnose

leukemia and lymphoma; precise identification of tumor cell types

76

Flow cytometry + mAB-tag

label cell surface antigens with mAb-tag; side scatter, forward scatter, and intensity determine cell type

77

Agglutination reactions procedure

large particle-antigen or particle-antibody; aggregates = presence of antigen or antibody in specimen

78

Agglutination reaction use

detect antibodies or antigens in specimen

79

Protein electrophoresis

detect presence and relative concentration of proteins (from serum, urine, or CSF)

80

Stat tests include tests

whose results are ESSENTIAL for patient care, lab runs test before continuing other work

81

Direct ELISA

Plate with specificity for antigen + patient unknown [antigen] + antibody-tag + substrate; colorimetric (primary Ab)

82

Indirect ELISA

Plate with antigen + patient unknown [antibody] + anti-human IgG-tag + substrate; colorimetric (Primary and Secondary Ab)

83

Sandwich ELISA

Plate with antibody + patient's unknown [antigen] + primary Ab + secondary Ab + substrate

84

Electrolyte Panel includes

Na, K, Cl, CO2, glucose, BUN, creatinine

85

Stat tests usually involve

electrolytes, gases, chemistry profile, clotting/coagulation test, gram stain

86

Blood gases measure

pH, pCO2, pO2, O2 sat, total CO2

87

Blood gas requires

whole blood + 3 electrodes

88

Hydrogen electrode measures

pH

89

Carbon dioxide electrode works by

measuring pH change due to CO2 diffusion; [CO2] is directly related to pH change

90

ELISA spot used for

monitoring cellular immune responses by visualizing secretory products of individual activated cells

91

ELISA spot procedure

sandwich ELISA: immobilized specific antibody + secreting cells, remove cells and add primary antibody for secreted antigen + secondary-enzyme + substrate; visualize

92

Immunoflourescence immunoassay

cells from patient + antibody of interest + secondary-tag; visualize for presence/titer/pattern

93

oxygen probe for blood gas testing

complete electrochemical cell producing a current as oxygen migrates; current is DIRECTLY related to [O2]

94

Point-of-care testing

specimen testing outside of a lab/hospital, hand-held portable analyzers, miniaturized test