Block 9 Flashcards
(163 cards)
0
Q
What are basket cells?
A
They surround the base of the hair follicle and sense pressure.
1
Q
What are the 3 main layers in the skin?
A
Epidermis, dermis, sub cutis
2
Q
What are merkel cells?
A
They are found at the basal layer of the epidermis and acts as sensory receptors.
3
Q
What are the 4 layers of the epidermis?
A
Basal layer
Stratum spinosum
Stratum granulosum
Stratum corneum
5
Q
What are the 2 layers of the dermis and their functions?
A
There are 2 layers: Papillary layer (most superficial): thin arrangement of collagen, highly vascular Reticular layer: collagen fibres are thick and lie parallel to the skin, provides structure and elasticity. Supports sweat glands and hair follicles, contains nerves.
6
Q
What are the functions of the skin?
A
Prevents dehydration Protects the body from toxins Innate immunity Protects from UV Sensory reception Temperature regulation Calcium homeostasis
7
Q
Define a 1st degree burn and how it heals
A
Only affects epidermis - red, no blisters and painful
Dermis supports regeneration of epidermis and the skin gets inflamed to encourage the clean up of cells
8
Q
Define a 2nd degree burn and how it heals
A
Effects the papillary dermis - Red, blisters and very painful
Some of the skins accessory organs remain - hairs and glands. Epithelial cells that line these structures have the ability to divide and regenerate the epidermis
9
Q
Define a 3rd degree burn and how it heals
A
All of the dermis is removed - white, no blisters, no pain
Requires a skin graft to heal - strong risk of infection
10
Q
Describe the zones of a burn
A
Zone of coagulation - this occurs at the point of maximum damage. Here there is irreversible loss of tissue due to coagulation of constituent proteins
Zone of stasis - decreased tissue perfusion, tissue is potentially salvageable. Burns resuscitation will increase tissue perfusion
Zone of hyperaemia - outermost area, tissue perfusion, tissue will recover
11
Q
What are the systemic responses and what is the body burn percentage required?
A
30% of total body surface area - release of cytokines Peripheral vasoconstriction Myocardial contractility Systemic hypotension Bronchoconstiction Increased basal metabolic rate Decreased regulation of immune response
12
Q
How does a blister occur?
A
Mechanical fatigue of the epidermis
Fatigue causes a split in the stratum spinosum
Separation and hydrostatic pressure allows a fluid pocket to form in the space
New cells divide in the basal layer to allow repair
13
Q
Advantages and disadvantages of solid medication
A
Advantages
- more accurate in a full tablet dose
- Can have a timed release
- easier to transport
- less expensive to produce
Disadvantages
- harder to swallow, choking hazard
- lower absorption rate
- inaccurate for smaller doses
14
Q
Advantages and disadvantages of liquid medication
A
Advantages
- easier to swallow
- can accurately measure small doses using a syringe
- rapid absorption
Disadvantages
- specialist equipment required for measurement
- more expensive to produce
- taste
15
Q
Risk factors for atheromas
A
Increased age Male Strong family history Smoking Obesity Hypertension Hyperlipidaemia Diabetes Genetics Increased alcohol intake South Asian or african
16
Q
What happens in reversible cell injury?
A
Impaired mitochondrial function cessation of oxidative phosphorylation Fall in ATP impaired functioning of energy dependent Na+ pump Na+ and water enter the cytoplasm
17
Q
Define necrosis and describe the range of cellular appearances
A
Cell death. Cytoplasmic changes - swelling - increased eosinophilia - increased binding to denatured proteins - Glassy appearance: vacuolation
Nuclear changes
- dark clumps (PYKNOSIS)
- fragmentation (KARYORRHEXIS)
- dissolution (KARYOLYSIS)
18
Q
Define apoptosis and describe the range of cellular appearances
A
Programmed cell death
Absence of inflammatory tissue reaction - occasionally seen in disease states, can lead to neoplasms
19
Q
What are the 4 stages of apoptosis?
A
- Induction: signal transduction, damage to mitochondrial membrane, DNA and cell membrane
- Effector: signalling and other initiating events integrated by specific proteins, modulation of mitochondrial membrane permeability, accumulation of p53
- Degradation: activation of caspases, cross-linkage of structural proteins, DNA degradation
- Phagocytosis: attraction of macrophages, binding of thrombomodulin
20
Q
What are the different types of necrosis?
A
- Coagulative: infarcts
- Liquefactive: infections
- Caseous: TB
- Fat necrosis: acute pancreatitis
- Fibrinoid: immune reaction in vessels
- Gangrenous: entire limb loses blood supply
21
Q
Define: atheroma
A
accumulation and swelling in artery walls made up of macrophage cells, debris, lipids, calcium and connective tissue
NO ADIPOSE CELLS - macrophages that have taken up oxidised LDL
22
Q
What are the 3 steps involved in the formation of atheromas?
A
- Fatty streaks develop in the site of stress, monocytes migrate in the intimal wall and absorb lipids
- Monocytes become foam cells and die off. Cells from the tunica media stabilise the lipid pod forming a fibrous cap.
- Plaque continues to grow, disrupting normal blood flow. It can then become unstable and form a thrombus
23
Q
Define: infarction
A
Tissue death (necrosis) caused by a local lack of oxygen due to an obstruction of the tissues blood supply
24
Q
Causes of infarction?
A
Obstruction Compression Trauma Vasoconstriction Hypotension Torsion
25
What are white and red infarctions?
White - affects solid organs. There is arterial obstruction to solid tissues
Red - occlusion of a vein, congested tissues, tissues with dual circulation
26
What are the 3 principal components of ischemia?
Hypoxia
Insufficiency of metabolic substrates
Accumulation of metabolic waste
27
What are the steps of the ischaemic cascade?
1. Lack of oxygen causes a lack of energy (ATP) so the cell switches to anaerobic metabolism
2. ATP transport pumps fail and calcium flows into the cell
3. Increased calcium generates free radicals, reactive O2 species and enzymes
4. Cell membrane is broken down as are mitochondria
5. Death of cells and inflammatory response
28
Describe the structure of a hair
Inner - Medulla
Middle - cortex
Outer - cuticle
29
What are the 5 steps of wound healing?
Haemostasis (formation of fibrin blood clot)
Inflammation (removal of bacteria and damaged tissue)
Fibroplasia and angiogenesis (fibroblasts lay down new collagen)
Epithelisation (migration and mitosis of keratinocytes)
Remodelling
30
Describe a gram negative cell wall
Lipopolysaccharide (LPS) on the outer surface with a thin layer of peptidoglycan between the inner and outer layer
Under a gram stain it appears pink
31
Describe a gram positive cell wall
Teichoic acid on the outer surface and a thick layer of peptidoglycan.
Under a gram stain it appears violet.
32
Define pneumonia and the different types
Any infection of lung parenchyma and can result whenever defence mechanisms are impaired.
Community acquired, hospital acquired, aspiration and chronic
33
What are the bacterial causes for pneumonia?
```
Steptococcus pneumoniae (most common)
Haemophilus influenzae
Moraxella catarrhalis
Staphylococcus aureus
Klebsiella pneumoniae
```
Staphylcoccus Aureua (hospital acquired)
34
What is the difference between lobar and lobular?
Lobular - patchy consolidation of the lung
| Lobar - consolidation of an entire lobe
35
What are the 4 stages of the inflammatory response of lobar pneumonia?
1. Congestion (lung is boggy and red, vascular enlargement)
2. Red hepatisation (confluent exudation of neutrophils and red cells, fibrin fills alveolar space)
3. Grey hepatisation (disintegration of red cells to grey)
4. Resolution (consolidated exudate undergoes enzymatic digestion
36
Streptococcus pneumoniae
Gram positive diplococci
| Normal flora in 20% of adults
37
Haemophilus influenzae
Gram negative coccobacillus
38
Staphylococcus aureus
Gram positive cocci
39
Risk factors for pneumonia
```
Extremes of age
Chronic airway disease
Heart disease
Suppressed immune system
Smoking
```
Hospital acquired - being on a ventilator, antibiotic use that is prolonged and immunosuppression
Aspiration - dibilitated patients
40
What are the 4 different types of genetic exchange?
Transformation - free DNA taken up by the cell
Transduction - DNA transfer by bacteriophage
Conjugation - transmission of plasmid between 2 bacteria
Transposons - jumping genes
41
What are the causes and implications of antibiotic resistance?
Causes:
INAPPROPRIATE PRESCRIBING
```
Implications:
Increased infections which are harder to treat
Increased morbidity and mortality
Prolonged hospital stay and complication
Economic cost
Increased patient worry
```
42
What are the 4 main routes for infection to enter the CNS?
Haematogenous
Direct implantation
Local extension
Transport along peripheral nervous system
43
What are the main causes of meningitis in the 3 different age groups?
Neonates - Escherichia coli & group B streptococcus
Adolescents - neisseria meningitidis
Elderly - streptococcus pneumoniae and listeria monocytogenes
44
What are the signs of meningitis?
```
Headache
Photophobia
Irritability
Clouding of consciousness
Neck stiffness
Cloudy CSF
Petechial rash (only in neisseria meningitidis)
Sudden onset
Positive Kernigs
```
45
What causes cloudy CSF in meningitis?
Increased neutrophils
increased protein
decreased glucose
46
What vaccines are available for meningitis?
A and C
| No B
47
Neisseria meningitidis
Gram positive diplococcus
48
Escherischa Coli
Gram negative baccilus
49
Group B streptococcus
Gram positive streptococcus
50
Listeria monocytogenes
Gram positive baccilus
51
What is the mechanism of antibiotic hypersensitivity?
Type 2 hypersensitivity
Beta lactam ring forms bonds with the body self proteins
It binds to erythrocytes forming a HAPTEN
This elicits TH2 response
IgE antibodies to self
Causes haemolytic anaemia
52
Public health protocol for meningitis?
Contacts are trace
Information is given to schools and universities
Cases referred to hospital quickly
Cases are investigated properly
Referred to disease control
Notify the HPA
Chemoprophylaxis is given if they have lived in the same household for a week
53
Chemoprophylaxis for meningitis?
Rifampicin
| Ciprofloxacin
54
Define: strict pathogen
not found in normal flora
55
Define: opportunistic infection
normal flora that cause disease when given to unprotected sites
56
Define: faculative pathogen
can grow and survive in the environment as well as the host
57
How can viruses be categorised?
Enveloped vs naked
Single strand vs double strand
Positive sense vs negative sense
DNA vs RNA
58
Limitations of antivirals
```
few drugs are available
drug resistance
high mutagenic rate
latent and persistent infections
other interactions causing side effects
expensive
adherence to medication
```
59
How is varicella zoster spread?
aerosol or direct contact
60
Describe the infection pattern of VZV
Primary infection in childhood
Can be reactivated in later life
VZV perrsists in the dorsal root ganglion of sensory nerves
61
Clinical features of VZV (chicken pox)?
```
burning discomfort in dermatome
discrete vesicles after 3-4 days
brief viraemia
severe prolonged rash
thoracic dermatomes most common, however can be opthalmic
```
62
Varicella Zoster Virus
- transmission
- virus structure
Herpes virus
Double stranded DNA virus, capsulated
Highly cell associated and attached to proteoglycan on cell surface
transmitted via the respiratory route and direct contact
63
Epidemiology of VZV
Epidemics more prevalent in temperate climates
Epidemics occur in later winter and spring
Varicella between 5 and 10 years
incidence = birth rate
Zoster - 3/1000/year most common in over 45s
More common in those with immunosuppression, leukaemia, steroid therapy.
64
Pathogenesis of varicella zoster virus
- Primary viraemic stage - virus travels to regional lymph nodes and liver for incubation period (14 days)
- Secondary viraemic stage - spread to skin and mucous membranes and viral release into the respiratory system
- Maculopapular phase - vasculitis and fusion of epithelial cells. Also affects cells of lymphatic vessels
- Vesicular phase - ballooning degeneration of epithelial cells, fluid fills spaces between cells
65
Consequences of inadequate body response to VZV
Varicella pneumonia (infection of alveoli and inadequate oxygen transfer)
- Transient hepatitis (extensive viral replication in the liver and hepatocellular destruction)
- Varicella encepholitis
- Cerebellar ataxia
- Thrombocytopaenia
66
Clinical features of varicella zoster (shingles)
Localised, puritic, vesicular rash in 1-2 dermatomes
Progression to large fluid filled lesions
Localised neuropathic pain
Severe pain (can last longer than rash)
67
Prophylaxis for shingles/chicken pox?
Difficult due to infection 2 days before symptom onset
Infected patients must be treated in isolation
IgG is given if immunocompromised or pregnant
Acyclovir (must be given within 3 days after rash onset)
68
Cause of infectious mononucleosis
Epstein Barr Virus (90%)
| Cytomegalovirus (10%)
69
Epstein Barr Virus
Transmitted by close human contact (saliva)
Enveloped
DNA virus
70
Pathogenesis of infectious mononucleosis
- Infection begins in nasopharyngeal and oropharyngeal lymphoid tissue and spread to epithelium and submucosa
- EBV envelope binds to B cells
- Latent infection
- B cell activation and proliferation
- B cells disseminate and secrete antibodies
- Reactive T cell proliferation causes enlargement of lymphoid tissue
71
Presentation of glandular fever
```
low grade fever
fatigue/ prolonged malaise
sore throat
enlarged tonsils
fine macular, non-prutic rash
bilateral upper lid oedema
lymphadenopathy
nausea
anorexia
mild hepatomegaly and splenomegaly
```
72
What areas of the brain are responsible for temperature regulation? What is required to raise the set point?
Preoptic and anterior hypothalamic nuclei
| Prostaglandin E2
73
What is responsible for temperature regulation?
- dermal blood flow
- pili erector muscles
- eccrine sweat glands
- dermal thermoreceptors
- skeletal muscle (shivering)
- hypothalamus
- adipose tissue
- sympathetics
74
Different types of fever
Continuous (no more than 1oC fluctuation in a day)
Intermittent (malaria)
Remittent (always present but less than 1oC fluctuation)
Hepatic/septic (steep fluctuation, septicaemia)
Pel Ebstein (recurrent bouts, glandular fever)
Low grade (<37.8)
75
How are communicable diseases controlled?
Surveillance
Preventative measures
Outbreak investigation
Control measures
76
Define: epidemic
occurrence in a community or region of cases of an illness or other health related events clearly in excess of normal expectancy
77
Define: outbreak
epidemic limited to localised increases in the incidence of a disease e.g. a town
78
Define: pandemic
epidemic occurring over a very wide area, crossing international boundaries and affecting a large number of people e.g. swine flu
79
What is a notifiable disease and give 3 examples and give procedures involved in preventing the spread
legal obligation to report to HPA
MRSA, C. Difficile and MSSA
screening of patients, barrier nursing (treating infected in isolation), sharp disposal, decontamination and sterilisation of instruments and HAND WASHING
80
Epidemiology of HIV
```
8% adults in sub-saharan africa
Homosexuals (50% and decreasing)
Intravenous drug users (20%)
Haemophiliacs (0.5%)
Recipients of blood or components (1%)
Heterosexual contacts of those in high risk group (10%)
Undetermined (5%)
Paediatric (from mother to baby = 2%)
```
81
Methods of transmission for HIV
- Sexual transmission (75%) carried in semen and enters through mucosal abrasions. It is also present in viral secretions and cervical cells
- Parenteral transmission in 3 groups. Intravenous drug users, haemophilacs who received factor 8 and 9, recipients of blood transfusions
- mother to infant transmission via 3 routes. In utero via placental spread, during delivery through infected birth canal, after birth through breast milk
82
Human Immunodeficiency Virus
RNA Retrovirus from the lentivirus family
Nucleocapsid protein p7
2 copies of RNA
3 viral enzymes - protease, reverse transcriptase, integrase)
Matrix protein around core p17
2 viral glycoproteins - gp41 and gp120
83
Describe HIV entry and replication
HIV enters through mucosal tissues and blood and infects T cells, dendritic cells and macrophages.
1. GP120 on HIV attaches to CD4 receptor
2. Conformational change
3. GP120 and CD4 receptor binds to CCR4 (chemokine receptor)
4. GP41 penetrations
5. membrane fusion
6. RNA genome enters the host
7. Reverse transcriptase creates proviral DNA
8. It is integrated into the host genome
9. Replication of proteins and forms virions for release
84
What cells do HIV infect?
T cells
memory and activated
NOT naive
85
In HIV infection how are T cell numbers reduced?
Direct killing of infected cells
Viral replication interfering with protein synthesis
HIV colonises in lymph glands causing the destruction of lymphoid tissue
Infection of thymic progenitor cells
Fusion of infected and uninfected cells (giant cells)
Infection of accessory calls that secrete cytokines for CD4 maturation
86
What is the role of macrophages in HIV infection?
They can be infected and allow viral replication however they are resistant to cytopathic effects.
Reservoirs of infection
HIV can be carried to the brain by macrophages
87
Stages of HIV infection
1. Acute retroviral syndrome
Primary infection of cells, travels to lymph cells and infection becomes established in lymphoid cells. Occurs 3-6 weeks after infection and resolves within 2-4 weeks. Viraemia. Non specific illness - sore throat, fever, weight loss, diarrhoea, fatigue.
2. Latency/ middle chronic phase
Asymptomatic, low levels of infection. Provirus in host DNA
3. Activation by microbial infections or cytokines leading to extensive viral replication and CD4 cell lysis
4. AIDS - depletion to CD4 cells
88
How is HIV infection classified?
Asymptomatic or symptomatic
CD4+ levels/ microlitre
>500, 200-500, <200
89
What are some of the AIDS defining opportunistic infections?
FUNGAL INFECTIONS - candidiasis, pneumocytosis, histoplasmosis, cryptococcus
VIRAL - cytomegalovirus, herpes simplex, VZV
BACTERIAL - norcardiosis, salmonella infections
90
Factors that inform decision to treat HIV
- recent exposure (last 72 hours) PEP
- CD4 below 350
- CD4 at 500 with hep B or C
- Radiotherapy
- Chemotherapy
- TB
- HIV related nephropathy
91
Risk factors for fungal infections
```
Broad spec antibiotics
Immunocompromised
Corticosteroid treatment
Radiotherapy
Intensive care
Extremes of age
Pregnancy
Cancer
```
92
What is HAART and what components are used?
Highly active AntiRetroviral Therapy
2 nucleoside reverse transcriptase inhibitors
with non nucleoside reverse transcriptase inhibitors
OR 1 or 2 protease inhibitors
It inhibits HIV replication and RNA is reduced to undetectable levels. Survival is prolonged however the regimen is complex and has many side effects. Compliance is difficult and treatment is life long.
93
What are the UK standard vaccinations given to children under 6 months?
```
Rotavirus gastroenteritis
Diptheria
Tetanus
Pertussis
Polio
HIB (haemophilis influenza B)
Meningitis C
```
94
What are the UK standard vaccinations for children above 1 year?
MMR
HPV
Boosters for DTP/Polio/MenC
95
What are the vaccinations that are given to adults?
Shingles (70&79)
Influenza (if high risk group of over 65)
Pertussis (pregnancy between 28 and 38 weeks)
Pneumococcal vaccination for pneumonia and meningitis for over 65s and high risk groups
Hep B if working with blood products
TB if born in high risk area
96
What are the different types of vaccinations?
- Inactivated e.g. pertussis
- Live attenuated e.g. measles, mumps
- Inactivated vaccines
97
Advantages and disadvantages of live attenuated vaccines?
Advantages
- strong cellular and antibody response
- lifelong immunity with 1 or 2 doses
Disadvantages
- can revert to virulent form
- can't be given to those with low immune systems
- must be kept refridgerated
98
Advantages and disadvantages of inactivated vaccines?
Advantages
- More stable and safer
- Easily transported and stored
Disadvantages
- weaker immune response
- boosters required
99
What are the 3 morphological classifications of fungi?
Moulds
Yeasts
Dimorphic
100
What are the features of a mould?
- growth by formation of filaments of HYPHAE
| - reproduce asexually through asexual spores or sexually
101
What are the features of a yeast?
- single celled organisms that are round or ovoid
- reproduce by budding
- some form elongated buds (pseudohyphae)
102
Cervical cancer is caused by a virus (which one)?
HPV 16 and 18
103
What is the function of viral proteins E6 and E7 in cervical cancer?
E6 - induces rapid degeneration of p53 via ubiquitin dependent proteolysis
E7 - complexes with the active form of RB, protmoting proteolysis via proteosome pathway
104
What is the definition of a HSIL (high grade squamous intraepithelial lesion) and LSIL?
LSIL - atypical immature squamous cells confined to lower 1/3 of epithelium
HSIL - expanded to 2/3 or epithelial thickness
105
How is cervical cancer treated?
Microinvasive - cone biopsy
More invasive - hysterectomy
Most advanced - irradiation
106
Describe the lesions found in eczema?
red, papulovesicular, oozing and crusted lesions.
| If it persists - raised scaling plaques due to hyperkeratosis
107
What are the different types of dermatitis?
- allergic contact
- atopic
- drug related
- photoeczematous
108
Pathophysiology of eczema?
- triggered by contact allergens
- antigens are taken up by dendritic langerhans cells
- migrate using dermal lymphatics to lymph nodes
- presented to naive CD4 t cells which are activated and produce memory cells
- on reexposure memory T cells migrate to affected skin sites
- adhere to postt capillary venules, extravastate into tissues and release cytokines and chemokines that recruit inflammatory cells
109
What are the different types of skin cancer?
Squamous cell carcinoma
Basal cell carcinoma
Melanoma
110
Features of a squamous cell carcinoma?
- discovered while small
- less than 5% metastasise
- deeply invasive, involve subcutis
111
What are the 2 main causes of squamous cell carcinoma?
DNA damage induced by UV light
Chronic immunosuppression
112
What is the role of p53 in cancer?
- damage to cells
- check point kinases ATM and ATR sense the damage
- They upregulate expression and stability of p53
- p53 arrests cells in G1
Promotes DNA repair or cell elimination
p53 dysfunction loses this protective function and is an early event in the development of cancer
113
Presentation of skin cancer - squamous cell carcinoma?
early
scaly or crusty area of skin or lump
red inflamed base
often tender
114
Risk factors for squamous cell carcinoma?
```
older people
people who work outdoors
fair skin
UV light treament
immunosuppression
```
115
Features of basal cell carcinoma?
- invasive
- slow growing
- rarely metastasise
- increased in sun exposed sites
116
Presentation of basal cell carcinoma?
- pearly papules often containing prominent dilated epidermal blood vessels.
- Some contain melanin
- Advanced lesions may ulcerate
117
Features of a melanoma?
- Evolve over time from localised skin tumours to aggressive tumours that metastasise and are resistant to therapy
- early recognition vital
118
Presentation of a melanoma?
- usually asymtomatic
- lesions >10mm in diameter
- Changes in colour, size and shape of pigmented lesion
- Variations of colour
- Asymmetry
- Borders (irregular)
- Colour (variegated)
- Diameter
- Elevated
119
Define Breslow thickness
the distance from the superficial epidermal layer to the deepest intradermal tumour cells
120
Risk factors for melanoma
- sun exposed surfaces
- lightly pigmented individuals
- 15% familial
- Female
- Family history
121
Pathogenesis of melanoma
Mutation that diminish the activity of RETINOBLASTOMA (RB) tumour suppressor proteins
P16 enhances activity of RB
30-70% of melanomas involves the loss of p16
Alterations in genes = increased melanocytic proliferation = escape from oncogene induced cellular senescence
122
How is cancer classified/ tumour staging?
TNM staging
T - size of original tumour and whether it has invaded nearby tissue (0-4)
N - any nearby lymph nodes involved (0-3)
M - metastasis (0-1)
123
What are the 5 mechanisms of cancer spread?
1. Transcoelomic - seeding the surface of peritoneal, pleural, pericardial or subarachnoid spaces e.g. surgical manipulation
2. Lymphatic spread
3. Haematogenous
4. Implantation
5. Local
124
What are the 8 hallmarks of cancer?
1. Self sufficiency in growth signals (oncogenes)
2. Insensitivity to anti-growth signals (tumour suppressors)
3. Evasion of apoptosis
4. Limitless replicative potential (telomerase)
5. sustained angiogenesis
6. tissue invasion and metastasis
7. reprogramming of energy metabolism
8. evasion of immune destruction
125
Define oncogenes
genes whose presence can trigger development of cancer
126
Define tumour suppressor genes
genes whose loss or inactivation can trigger development of cancer
127
Define macule
flat mark on the skin
Can be pigmented like a freckle or red as in capillary haemangioma
128
Define papule
small solid elevation of the skin <5mm in diameter
129
Define nodule
papule >5mm can be oedematous or solid
130
define vesicle
small blister <5mm
consists of clear fluid within/below the epidermis
131
Define cyst
nodule consisting of an epithelial lined cavity filled with fluid or semisolid material
132
Define plaque
palpable plateau like elevation of normal skin
133
Define purpura
extravastation of blood, red, discolouration of skin
134
How are cancer changes analysed?
- Histochemical stains
- Immunohistochemical stains
- Flow cytometry
- Cytogenetics
- FISH
- PCR
135
What is FISH?
Fluorescent in situ hybridisation
Uses special fluorescent dyes linked to pieces of DNA that can only attach to specific parts of certain chromosomes
Can show gene amplification
136
How can flow cytometry analyse cancer changes?
Tests cells from bone marrow, lymph and blood
Cell sample is treated with antibodies and passed in front of a laser beam. If sample contains antigens then the laser will make them give off light
Can be used to measure the amount of DNA in cancer cells
137
What are the risk factors for cervical cancer?
```
multiple sexual partners
promiscuous male partner
young age at first intercourse
high parity
persistent infection with HPV
use of oral contraceptives
smokers
immunosuppression
```
138
How is a squamous intraepithelial lesion diagnosed?
```
nuclear atypia
nuclear enlargement
hyperchromasia
coarse chromatin granules
variation in nuclear size or shape
cytoplasmic halos
```
139
What are the different types of cervical cancer and how common are they?
```
Squamous cell carcinoma (80%) = HSIL precursor
Cervical adenoma (15%) = adenocarcinoma in situ precursor
Adenosquamous and neuroendocrine = 5%
```
140
How often is a pap smear carried out?
25 years upwards - every 3 years
Over 50 years - every 5 years
10% false positive
141
What vaccinations are given at 2 months?
5 in 1 - dipetheria, tetanus, pertussis, polio, haemophilus influenzae
Pneucococcal vaccine
Rotavirus gastroenteritis
142
What vaccinations are given at 3 months?
5 in 1 (2nd dose) - diptheria, tetanus, pertussis, polio, haemophilus influenzae
Meningitis C
Rotavirus
143
What vaccinations are given at 4 months?
```
5 in 1 (3rd dose) - diptheria, tetanus, pertussis, haemophilius influenza, polio
pneumococcal vaccine (2nd dose)
```
144
What vaccinations are given at 1 year?
Haemophilus influenza B (4th)
Meningitis C (2nd)
MMR
Pneumococcal (3rd)
145
What vaccinations are given at 3 1/2 years?
MMR (2nd)
| preschool booster 4 in 1 = diptheria, tetanus, pertussis, polio
146
What vaccinations are given at 12-13 years?
HPV
147
What vaccinations are given from 13-18 years?
Polio booster
| Men C booster
148
What is leukaemia?
| What are the common features?
neoplastic proliferations of white blood cell precursors
Diffuse replacement of normal bone marrow by leukaemic cells with variable accumulation of abnormal cells in the peripheral blood
Bone marrow failure leading to anaemia, neutropaenia, thrombocytopaenia
149
What are the features of acute leukaemia?
Leukaemic cells don't differentiate
Bone marrow failure
Rapidly fatal if untreated
Potentially curable
150
What are the features of chronic leukaemia?
Leukaemic cells retain the ability to differentiate
Proliferation without bone marrow failure
Survival for a few years
Not curable without bone marrow transplant
151
Describe how acute leukaemia occurs?
Arises from mutations in haemopoietic stem cells. These cells proliferate but lose the ability to differentiate into mature blood cells.
It leads to an accumulation of blast cells in the bone marrow and thus bone marrow failure.
152
What are the clinical features of acute leukaemia?
They reflect inadequate haematopoiesis secondary to bone marrow infiltration
Anaemia - SOB, tiredness, weakness
Leukopaenia - recurrent infections
thrombocytopaenia - bleeding and bruising
Marrow infiltration - bone pain
153
What are the 2 types of acute leukaemia?
```
Acute myeloid (myeloblastic) leukaemia AML
Acute lymphoid (lymphoblastic) leukaemia ALL
```
154
Describe AML
acute myeloid leukaemia
median age of presentation is 65 years
may arise with unknown aetiology or related to cytotoxic chemotherapy
must have at least 20% blast cells in bone marrow for diagnosis
155
Describe ALL
acute lympohoid leukaemia
most common between 2-4 years and is the most common cause of childhood cancer
majority of cases arise from B cell precursors
156
What are the clinical features of chronic leukaemia?
```
symptomatic anaemia
abdominal discomfort
splenomegaly
weight loss
fever
sweats
```
157
What are the 2 different types of chronic leukaemia?
chronic myeloid leukaemia CML
| chronic lymphocytic leukaemia CLL
158
Describe CML
occurs in all age groups
median survival of 5 years
normal bone marrow replaced with clone derived from pluripotent stem cell (philadelphia chromosome)
Erythoid, megakaryocytic and B lymphocytes all carry the defect as well as the granulocytes
159
Describe CLL
occurs predominantly in later life 65-67 years
most common leukaemia and occurs in B cells (95%)
Median survival of 25 years and generally does not require therapy
Can have either: naive B cell blasts (shortened prognosis) or fully functioning B cell blasts
160
Name some bio mechanical markers of cell death?
Creatine kinase - muscles
Troponins - cardiac muscle
ALT - liver
161
What happens in irreversible cell death?
Lysosomal contents leaks into cytoplasm
Enzymatic digestion of cell constituents
Cell components leak into extra cellular space
162
Define thrombosis
Formation of clot from blood constituents with vascular system
163
Risk factors for thrombus formation?
```
Age
Immobilisation
Trauma
Surgery
Cancer
Pregnancy
Oral contraceptive
Smoking
Radiation
Heart disease
```
