Block 9 Flashcards

Question

What is quorum sensing?

Answer 1

The ability of bacteria to behave as a multicellular organism by secreting and sensing different amounts of chemicals. E.g. autoinducer peptides which only take effect when concentrations reach high levels. Enables bacterial colonies to lie dormant.

Answer 2

Bacterial surface molecules (techoic acid/protein F) which allow bacteria to adhere onto host cells.

Answer 3

Small protein fillaments which vary between bacterial species and allow bacterial adherence to SPECIFIC cells of the host's body.

Answer 4

Endotoxin = toxins imbedded into the becterial cell wall (lipopolysaccharide on gram -ve) Exotoxins = toxins that are secreted by the bacteria into the host body. (enzymes, neurotoxins, superantigens etc.)

Answer 5

Community acquired Hospital acquired Aspiration Chronic

Answer 6

``` S. pneumoniae H. influenzae M. catarrhalis S. aureus Enterobacteriaceae ```

Answer 7

Enterobacteriaceae | S. aureus

Answer 8

Fungal infections: Nocardia, Actinomyces etc. M. tuberculosis

Answer 9

Viral respiratory infections cause a build up of mucus (consolidation) and damage to the mucocillary system within the lungs. This creates a prefect environment to harbor the growth of bacterial pathogens.

Answer 10

Lobar = Consolidation of a large part/lobe of the lung Lobular bronchopneumonia = Patchy consolidation of the lung.

Answer 11

Congestion = (vascular enlargement, intra-alveolar fluid and LOTS of bacteria) Red Hepatization = leekage of erythrocytes causing the lung to become red and airless (like the liver) Gray Hepatization = degredation of the erythrocyte, lung still consolidated Resolution = Digestion of the consolidated exudate, lung can become scared or permenantly recover.

Answer 12

``` Fever (hypothalamic changes) Cough (mucosal irritants) Rigors (to raise temperature) Fatigue Headache (vascular constriction) Decreased appetite Nausea and vomiting Chest pains on breathing (hypersensitivity of nociceptors) Shortness of breath (consolidation) ```

Answer 13

Immunosuppressed vulnerable state Mechanical ventilation Prolonged antibiotic use

Answer 14

Gram +ve cocci in chains Most common cause of community acquired pneumonia, diagnosis via sputum culture although false positives due to normal flora

Answer 15

Capsulated gram -ve bacillus. Most common cause of gram -ve pneumonia. Creates a very sticky mucus due to the large polysaccharide capsule.

Answer 16

``` Reduced cell wall permeability Eflux of the drug from the cell Alteration of the target site Enzymes which inactivate the drug Development of a new metabolic pathway ```

Answer 17

Transformation = free DNA taken up by the cell Transduction = DNA transferred by bacteriophage Conjugation = Purpousful transmission of a PLASMID between 2 bacteria Transposons = jumping genes that can change position within the bacterial genome.

Answer 18

Increase in hospital acquired infections which are harder to treat Delayed response for propper treatment Increased mortality and morbidity Increased complications Increased patient worry

Answer 19

Longer hospital stay More expensive drugs (last line) required Screening costs Isolation costs (the estimated cost of MRSA to the NHS is £3.2-£4 billion p/y)

Answer 20

More prudent prescribing Education Infection control Need to increase the development of new drugs

Answer 21

Acute pyogenic (bacterial) meningitis Acute aseptic (viral) meningitis Chronic meningitis

Answer 22

Fever Headache Stiff Neck Irritibility Photophobia Coluding of consciousness Purpuric rash (only with neisseria meningitidis)

Answer 23

When the bacteria dies it produces an endotoxin which causes activation of clotting factor XII and results in abnormal intravesicular clotting

Answer 24

Nonatal = H. influenzae, group B strep, E.coli Teenage = Neisseria meningitidis Geriatric = S. pneumoniae, L. monocytogenes

Answer 25

Presentation = reduced symptoms to bacterial meningitis Signs = no sign of meningococcal organisms in blood/CSF Treatment = symptomatic, the disease is self managing.

Answer 26

Hydrocephalus = increased intracranial pressure due to water Endarteritis = inflamation of arterial tunica intima and resulting necrosis of the underlying brain tissue.

Answer 27

N. meningitidis = gram -ve diplococci E.coli = gram -ve bacillus B Strep = gram +ve cocci on chains H. influenzae = gram -ve coccobacillus S. pneumoneae = gram +ve cocci in chains L.monocytogenes = gram +ve bacillus

Answer 28

Both type 1 and type 2 allergies. Hapten = a joining of the antibiotic and a host molecule as normally antibiotics are too small to elicit host immune responses. E.G. penicillin forms haptens with RBC proteins due to highly reactive beta-lactem rings Type 1 = IgE hypersensitivity to the antibiotic hapten during re-exposure. Type 2 = Antibody mediated attack of the bodies own cells as the hapten remains attached to the cell. E.G. penicillin can cause a type 2 hypersensitive haemolytic anaemia.

Answer 29

The outer surface has teichoic acid on the outer surface with a thick layer of peptidoglycan underneath.

Answer 30

They surround the base of the hair follicle and sense pressure.

Answer 31

this is the normal flora of the body. Stimulate the immune system Competition for pathogen colonisation Produce beneficial nutrients

Answer 32

They connect neighbouring cells together to provide structural support.

Answer 33

They are maturing cells from the basal layer that produce keratin they mature and adhere together.

Answer 34

They are found in the basal layer of the epidermis and act as sensory receptors.

Answer 35

Haematogenous spread Direct implantation Local extension Transport along CNS

Answer 36

A factor that facilitates colonisation, growth and spread in the host. It is only a virulence factor if it is no longer a pathogen without it. e.g. adhesins, flagella, toxins and capsule.

Answer 37

Adherence of bacteria to host cells Ability to invade host cells Ability to deliver toxins to tissues

Answer 38

Minimum Inhibitory concentration | It is the minimum concentration of the antibiotic required to inhibit bacterial growth

Answer 39

Those with prolonged contact in a household setting in the 7 days prior to the case. Transient close contact if exposed to infected droplets.

Answer 40

1 phospholipid bilayer thick peptidoglycan layer Adhesins in peptidoglycan (Teichoic acid, protein F)

Answer 41

Coagulative necrosis = normal organ parenchyma Liquefactive necrosis = CNS tissue Gangrenous necrosis = coagulative necrosis of the peripheral limbs Fat necrosis = necrosis of adipose tissue. Most commonly in the abdoman as a result of acute pancreatitis.

Answer 42

2 phospholipid bilayers enclosing a thin lipopolysaccharide layer Lots of antigenic (toxic) lipopolysaccharides imbedded in the wall.

Answer 43

16s RNA = identifying pary of the bacterial ribosome = good at SPECIES identification Full genome sequencing = very detailed, can find different bacterial serotypes.

Answer 44

Lag phase Exponential growth phase Stasis phase (limitation of nutrients) Death

Answer 45

DNA mutation Genetic exchange (Conjugation, transformation, transduction, transposons)

Answer 46

``` Exposure Adherence Colonisation Toxin production and invasiveness Disease ```

Answer 47

``` Flagella Pili Adhesins Toxins Capsules ```

Answer 48

Hiding within cells Antigenic variation (can cause resistance due to a single point mutation) Molecular mimicary Modification or blockage of the immune system

Answer 49

It can determine if a bacterium is pathogenic or not. E.coli K12 = non-pathogenic E.coli 0157 = food poisoning or haemolytic anaemia E.coli K1 = neonatal meningitis

Answer 50

That a bacteria can be said to cause a disease if it can be isolated from a diseased animal and induces the same disease if introduced into a helathy animal.

Answer 51

It is due to the mechanical fatigue of the epidermis. A split occurs in the stratum spinosum. As they separate the hydrostatic pressure allows fluid to form in the space. New cells in the basal regenerate to form the new skin layer.

Answer 52

Encapsulated = contained in a phospholipid bilayer that it broke off during endocytosis Naked = just a capsid containing bacterial genetic information

Answer 53

Naked = spreads more easily and more stable Encapsulated = must stay wet, sensitive to detergents, does not need to lyse cell to reproduce.

Answer 54

RNA (double and single stranded)

Answer 55

``` Varicella pneumonia Varicella hepatitis Varicella encephalitis (vasculitis of vasa nervosum) Thrombocytopaenia (reduced platelets) Adrenal necrosis ```

Answer 56

Exopsure --> 14-21 day incubation --> symptoms --> systemic rash

Answer 57

``` Macules = change of skin colour Papules = raised skin lesions Vesicles = small blisters w/ clear fluid Pustules = small purulent blisters ```

Answer 58

Encapsulated Double stranded DNA Cell associated replication HIghly temperature sensitive (50-60 oC)

Answer 59

Initial transmission = respiratory droplet. After infection, virus has a 2-3 w incubatory peroid (in the mononuclear phagocyte system) where the patient is infectious just before the onset of symptoms The rash is caused by the viral replication inside the epithelium of the respiratory mucosa. Complications result from infalmmation of other organ epithelium Rash = macular papular --> vesicular --> pustular --> crusting

Answer 60

SHINGLES (zoster) After primary infection with the VZV it lays dormant in the dorsal roots of nerve ganglia. Here it consistently reactivates but usually subclinically. Sometimes (rarely 3/1000) the virus causes a clinical infection of the nerve resulting neuropathic pain and a vesicular rash localsed within the borders of the neurological dermatome. Recurrence of the infection is common in immunocompromised patients (chemotherapy, steroid therapy, HIV, etc...)

Answer 61

High levels of passive immunity (IgG antibodies) given within 72 hours of the contact with infectious individual. Preganant women Immunocompromised patients Newborns

Answer 62

``` T = toxoplasmosis O = other vertical infections R = Rubella C = Cytomegalovirus H = Herpes viruses S = syphilis ```

Answer 63

``` Adherence to treatment Resistance Cost Interactions Side effects ```

Answer 64

``` Complex regime Poor Dr. - patient interaction Other druge use Severe side effects Mental illness Lack of patient education ``` Very important becuase effectiveness is strongly correlated to adherence to treatment complex regimes are not as important now. Antiretroviral theray was 21 p/d in 1996, now 2/d

Answer 65

Some viruses (HIV) are very good at resisting antivirals through their VERY high mutation and replication rates. This requires the use of multiple drug therapy but that comes back to more complex treatments. Difficulty is keeping doses high enough to prevent resistance but low enough to prevent serious side effects (sin curve).

Answer 66

``` Gain: Basal metabolic rate Extra metabolism (shivering, exercise) Digestion of food Fat acts as insulation (1/3 normal conduction) ``` ``` Loss: Peripheral vasodilation Sweating (Evaporation) Conduction and convection Radiation ``` Both also have behavioural changes

Answer 67

Preoptic and anterior hypothalamic nuclei.

Answer 68

Cold receptors: Mainly in the periphal skin and some central arteries The hypothalamic nuclei To prevent hypothermia Heat receptors: Mainy in the hypothalamic nuclei The vast majority of temperature sensation comes from temperature sensors directly within the hypothalamus itself.

Answer 69

There are many substances (pyrogens) which can raise the hypothalamic temperature set point = PYROGENS! Two types of pyrogen. Exogenous = pathogen breakdown products and gram -ve LPS. These act on phgocytic cells to produce interleukin 1. Endogenous = interleukin 1. This acts on the hypothalamus to cause the creation of prostaglandin E2 which, whilst present in the hypothalamus causes a rise of the set point.

Answer 70

They incativate the COX enzymes (importantly 2) which catalyse the formation of prostaglandins from arachnodonic acid. PgE2 is the main regulator of the temperature set point that acts on the hypothalamus to cause pyrexia.

Answer 71

Continuous = constant with change of 1ºC - 5ºC< [typhoid, infective endocarditis] Septic = fever with changes > 5ºC [some septicaemias] Pel Ebstein = continuous recurrence of fever with days between changes [Hodgkins lymphoma] Low grade = slight rise in temperature [possible TB]

Answer 72

+ve sense RNA = same direction of mRNA so can be directly converted to protein -ve sense RNA = must be converted to +ve sense RNA (RNA polymerase) before use to form proteins. DNA -ve sense strand is used to form mRNA, therefore, opposite.

Answer 73

EBV is present in 95% of pop. Clinical symptoms in 50% of adolescents infected. Transmission = oral Initial site of infection = oropharyngeal membrane Invades B-cells Latent within B-cells Infection --> 30-40 d incubation --> symptoms (1-4 w) The virus can re-activate from B-cell latency, causing proliferation, leading to IM / Burkitt lymphoma with specific gene translocation. (RARELY immunocompromised)

Answer 74

``` Monspot test (70% sensitive 99% specific) = agglutination of horse RBC's due to production of specific antibodies from B-cell proliferation ``` Atypical lymphocytes in peripheral blod Presence of antibodies for EBV envelope and nuleceocapsid

Answer 75

Homosexual and bisexual men IV drug users Haemophiliacs Sexual contacts of high risk groups (particularly if other STI's are present) Children of HIV +ve mothers

Answer 76

Transplacental Delivery through infected birth canal (micro-abrasions) Ingestion of infected breast milk

Answer 77

HIV-1 = western world and asia HIV-2 = west africa and parts of india

Answer 78

``` Envelope P17 matrix Nucleocapsule 2 copies of +ve sense RNA Integrase, protease, reverse transcriptase GP120 and GP41 membrane proteins ```

Answer 79

1 = gp120 binds to CD-4 receptor 2 = Conformational change in gp120 3 = gp120 with CD-4 binds to CCR-5 receptor 4 = confromational change in gp41 and adherence to the cellular surface membrane 5 = Membrane fusion and release of nucleocapsid

Answer 80

1 = entry to the cell nucleus 2 = Reverse transcription of viral RNA to double stranded DNA 3 = integration of viral DNA into host genome 4 = transcription and translation of viral DNA to make new viral proteins 5 = Extensive viral budding and cell lysis.

Answer 81

If the T-cell has been activated, the viral proteins are formed. If the T-cell is naive then HIV cannot replicate due to the presence of a protein which inserts mutations into the viral DNA.

Answer 82

It destroys T-cells. Even when the virus is 'dormant', over 10 Billion virons are produced daily, leading to the destruction of 1-2 Billion CD4+ cells The removal of T-cells ultimately cripples the immune system and leads to uncontrollable opportunistic infections.

Answer 83

Acute viraemia Latency period AIDS

Answer 84

Initially the virus infects cells in the mucosal tissue (T-cells, macrophages, dendritic cells) which then migrate through the body to the lymph nodes. Here the virus replicates wildly, leading to an acute viraemia (3-4 w after initial infection) and flu-like symptoms (sore throat, malaise, fever, weight loss). This passes after around 2 weeks as the body mounts an adaptive response to the virus. The virus enters a latent period where it is kept under control by the immune system but there is still steady destruction of T-cells. The T-cells are replaced by the body up to a point, but eventually the CD4 count becomes so low that opportunistic infections are common and AIDS is diagnosed. (GRAPHS)

Answer 85

Based on the CD4 count. Asymptomatic || >500 = A1 || 200-499 = A2 || 500 = B1 || 200-499 = B2 || <200 = B3

Answer 86

Dramatic increase in viral load in blood Long lasting fever >1 month Fatigue, weight loss, diarrhoea AIDS defining opportunistic infections

Answer 87

Around 7-10 years Can be as little as 2 Can be more the 15-20 (elite controllers)

Answer 88

Fungal pneumonia (Pneumocystis jiroveci) Candidiasis (Candida albicans) Chorioretinitis (Cytomegalovirus) Tuberculosis infections Cryptococcus (Cryptococcus neoformans) Shingles (VZV)

Answer 89

Karposi's sarcoma (Herpes virus 8) Burkitt lymphoma (EBV) Cancers from HPV

Answer 90

Some evidence for starting when CD4 count is normal (above 500) Good evidence for effectiveness when count is 350-500 Very goud evidence for effectiveness when count is below 350 Some groups where HAART should be started ASAP: - Pregnant women - < 200 cells/mm^3 - Any AIDS defining conditions - Declining CD4 count of more than 100 per year - Co-infection with Hep B

Answer 91

Reduces risk of other conditions (CVD, liver and kidney problems, neurological diseases) Reduces risk of transmission Prolongue time before immunosuppression

Answer 92

Physical barriers: Condoms, dental dams, lubricants Not sharing needles or any other personal items w/ blood (toothbrushes and razors) Not breastfeeding HAART treatment

Answer 93

Nucleoside reverse transcriptase inhibitors (Zidovudine) Non-nucleoside reverse transcriptase inhibitors (Nevirapine) Protease inhibitors (Ritonavir) Integrase inhibitors (Enfuvitide) Entry inhibitors (Raltegravir)

Answer 94

Could be a member of one of the main 'at-risk' groups - Profound and prolonged neutropaenia - Acute leukaemia - Stem cell transplant recipients (chemo/radiotherapy required) - Graft rejection patients - Patients on immunosuppressive drugs - ICU patients This is because normally fungi are non-pathogenic due to the high resistance of human immunological system. Some fungal infections are normal (thrush), or could be the result of antibiotics.

Answer 95

Attenuated Pro = full immune response, low dose is effective Con = can revert to virulence, requires 'cold chain' Killed Pro = cannot revert to virulence, supplies B + T antigens Con = Not full immune response, requires adjuvants Toxoid Pro = no need to use organism Con = Only effective if toxin is only cause of disease Subunit Pro = No need for whole organism, very stable Con = Not full immune response, requires adjuvant

Answer 96

Fungi are: ``` Eucaryotes (membrane bound organelles) 80s ribosomes Reproduction can be sexual Can be multicellular Cell wall has chitin Cell membrane has ergosterol ```

Answer 97

Morphology (moulds, yeasts, dimorphic) Reproduction (Sexual, asexual, budding) Clinical manifestations (Superficial, subcutaneous, deep)

Answer 98

Moulds grow through the formation of hyphae. Yeasts don't. Some yeasts can form pseudo-hyphae which make the organisms look like moulds. This is how Candida albicans can be distinguished from other candida spp.

Answer 99

A colonisation of fugue on the skin without tissue invasion. Can include host immune response but doesn't have to.

Answer 100

Fingal infections of the lungs / airways. Caused by the inhalation of spores. Can cause symptoms of chronic lung infection Can disseminate to other organs ASPERGILLUS is the main mould!! which causes deep mycoses.

Answer 101

A cancer of the squamo-columnar junction of the cervix. One of the most common female cancers. LARGE correlation with infection by HPV.

Answer 102

``` Multiple sexual partners Young age at first intercourse High huber of births Persistant HPV infection Immunosuppression Combined oral contraceptive pill Smoking ```

Answer 103

HPV - 16 = 70% of all cervical neoplasia | HPV - 18 = 10% of all cervical neoplasia

Answer 104

Highly infective (present in 45% of female population at age 25 ish) but usually asymptomatic. Invades IMMATURE epithelial basal cells. High affinity to cervix due to high number of immature cells at the squamo-columnar metaplasic junction. Causes: Promotion of the cell cycle (Rb gene) Interruption of apoptosis (p53 gene) Centrosome duplication and genome instability Activation of telomerase to prevent genomic degeneration. HPV DNA is usually integrated into host genome in cancerous cells. (HPV is not the only factor in the development of cervical cancer!!)

Answer 105

Low grade intraepithelial lesions (dysplasia in lowest 30% of epidermis) High grade intraepithelial lesions (dysplasia in 30-100% of epidermis)

Answer 106

Squamous cell carcinoma (80%) Cervical adenocarcenoma Adenosquamous and neuroendocrine carcinoma Spreading mainly through direct infiltration to rectum, bladder, ureters and vagina. Can infiltrate local lymph nodes or metastasise long distance to liver/lungs/bone.

Answer 107

``` Well differentiated (cells resemble normal parenchyma) Isolated (doesn't progress past basement membrane) ``` -OMA = Only works for mesenchymal tumours, tumours of the epithelium follow different rules.

Answer 108

Anaplasia (undifferentiated) Lots of mitoses Pleomorphism (both of the cell and the nucleus) Nucleus with lots of chromatin, large and irregular. Loss of polarity (no apex or base) Possibly form into giant cells

Answer 109

Benign = because they are more differentiated and therefore, more like the cells they originate from. E.G. benign tumours of the thyroid gland have colloid filled follicles etc.

Answer 110

Self sufficiency in growth signals (oncogenes) Insensitivity to growth inhibitory signals (tumour suppressor) Evasion of apoptosis Limitless replicative potential (telomerase) Sustained angiogenesis Ability to invade/metastasise Defects in DNA repair

Answer 111

Proto-oncogenes are normal cellular genes which produce proteins relating to the cell cycle and its regulation. These can mutate to form oncoproteins which cause massive cellular proliferations. Synthesis of own growth hormones (autocrine signalling instead of paracrine) Mutation in growth factor receptors causing them to be always active. E.G. RAS protein, part of G-protein coupled receptor which activates protein kinases through phosphorylation of GDP. Mutation prevents de-phosphorylation and, therefore, continuous activation.

Answer 112

Cyclins and Cyclin Dependant Kinases (CDKs) form complexes to regulate the cell cycle. Their presence allows the cell to progress beyond certain 'restriction points' (G1/s, G2/m) where the cell checks DNA and organelle replication etc. They are regulated by various p genes (p53, p21, p27) which break the proteins down. These are TUMOUR SUPPRESSOR GENES

Answer 113

CDK-4 Cyclin D p53 (The gatekeeper protein)

Answer 114

G1/s = CDK-4 & cyclin D G2/m = CDK 2 & cyclin A/E = CDK 1 & cyclin B

Answer 115

Quiescence = temporary shutdown of cellular mitosis Senescence = permanent shutdown of cellular mitosis (usually from shortened telomeres).

Answer 116

Most cells (apart from stem cells) don't express telomerase and, therefore, their telomeres get shorter with every replication. They can only divide 60-70 times before senescence. Telomerase rebuilds the cellular telomere, allowing it ti divide indefinitely.

Answer 117

Once a tumor grows to 2-3mm it cannot receive nutrients etc. by diffusion. It must generate its own neovascular supply to meet its metabolic needs and grow larger.

Answer 118

The reason why of the millions of timor cells that are released into the circulation per day, only a few might go on to develop metastases. ``` Local invasion through basement membrane Passage through extracellular matrix intravasion Interaction with lymphoid cells timor cell embolus Adhesion to basement membrane Extravasion Metastatic deposit Angiogenesis and growth! ```

Answer 119

Staging is a broad overview on the type of cancer, how aggressive it is and how progressed it is. ``` Grading is a laboratory method for looking at: differentiation of cells tumor depth (if necessary) number of mitoses etc… ``` Cancer grading varies as much as staging but usually defined as: low, intermediate and high grade.

Answer 120

TNM = tumor, lymph nodes, distant metastasis T/N/M x = cannot be assessed T/N/M 0 = no evidence T/N/M 1 = Some degree of involvement T has Tis = carcinoma in situ N has 1-3 = degree of nodal involvement M only has 1 = distant metastasis are present Stages 1,2,3 & 4 1 = small tumour with no spreading all the way to 4 = lots of nodal involvement and distant metastasis Each cancer is different and for each, the TNM scales reflect onto the stages in different ways. Some cancers also have subgroups etc… Look up the table for each type of cancer.

Answer 121

Dysplasia = earliest form of cellular change observable by biopsy. A measure of how well differentiated the cells are and if they are proliferating normally. low, medium and high grade. CIS = High level dysplasia with increased risk of transforming into cancer. Cancer = A cellular change which, if left untreated, will spread or metastasise into surrounding tissues.

Answer 122

``` G1 G1/S checkpoint = DNA damage S G2 G2/M checkpoint = damaged or un-duplicated DNA Mitosis Cytokinesis ``` G1/S is overcome by CDK4 and cycling D G2/M is overcome by cycling B and CDK1 These are regulated most heavily by the TSG - p53

Answer 123

Causes the transcription of three major genes: P-21 which inhibits progression of the cell cycle GADD45 which initiates DNA repair BAX which initiates apoptosis. Inhibits two types of genes: Anti-apoptosis genes Growth promoting genes The cell tries to repair its DNA, If this fails it either undergoes apoptosis or becomes senescent.

Answer 124

Activation of p16 which binds to CDK 4 and inhibits it’s complex with cyclin D. This complex then cannot phosphorylate pRb to release E2F which is a transcription factor required for cell progression in the cycle.

Answer 125

A method of getting signals from the outside of cells to the the nucleus to cause an effect. Most commonly used for growth signals. Tyrosine kinase receptos Jak/Stat G-protein coupled receptors.

Answer 126

``` p16 p27 p53 RAS pRb ```

Answer 127

Because STP’s are: closely related to cellular growth contain a lot of pro to-oncogenes which can easily become oncogenic as a result of basic mutations.

Answer 128

RAS, which increases the transduction signal pathway by a ‘always on’ mutation. EGRF, PDGFR, VEGFR, which are receptors that mutate to become always on. c-SIS, a cellular mitogen which increases cellular proliferation.

Answer 129

Karyotyping = arresting division in metaphase & looking at the chromosomes to look for numerical or structural abnormalities. Good for gene translocations. (LOW RESOLUTION WHOLE GENOME) Fluorescence in-situ hybridisation (FISH) = similar to karyotyping but with the use of fluorescent markers to identify the presence of particular DNA sequences. Much more sensitive and quicker (cells don’t have to be in mitosis). PCR = Huge multiplication of wanted strand of DNA via addition of DNA primers and DNA polymerase. After 2 rounds, it is only the particular gene which is multiplied most. Gel electrophoresis to separate strands based on size. Smaller strands move further to +ve electrode. Genetic sequencing = lots of different methods. Getting much cheeper. Most specific as can search for any and all mutations in the full genome of the cells. DNA methylation = Detection of epigenetic changes in cancer cells. Methylated DNA can’t be read due to inhibition of transcription factors. Cancer cells have genome wide hypomethylation with unexpected genes of hypermethylation. Methylation sensitive restriction enzymes and PCR. DNA microaray = Plate with specific antisense DNA strands. Addition of segmented DNA sense strands with fluorescent dies allows identification of which genes are present.

Answer 130

Prepare = Right setting, significant others, attentive, sit down & turn off phone. Disclose = How much do they know, how much do they want to know, warning shot, clarification of understanding, step by step, small chunks. Follow up = Respond to emotions, answer any questions, arrange follow up appointments

Answer 131

``` C. dififcile = diarrhoea (GPB) C. tetini = tetanus (GPB) L. monocytogenes = meningitis (elderly) (GPB) E.coli = UIT (GNB) N. gonorrhoea = gonorrhoea (GNC) N. meningitidis = meningitis (GNC) S. aureus = cellulitis (GPC) S.pneumoniae = pneumonia (GPC) Salmonella = salmonella (GNB) H. influenzae = pneumonia (GNB) ```

Answer 132

Neutropenia Thrombocytopenia Anaemia

Answer 133

Symptoms associated with lymphoma and CLL. Weight loss Night sweats Fever (Pel-ebstein)

Answer 134

Patient factors: Age, gender, lifestyle, genetics, etc… Disease factors: Pathogen, type of cancer, etc...

Answer 135

Transcoelomic - spread into body cavities Lymphatic spread Vascular spread Transplantation / implantation

Answer 136

Bronchial carcinoma (non-small cell) Mesothelioma Chronic infections (brenchiectasis, cyctic fibrosis) Congenital heart defects (atrial septal defect, patent ductus etc…) Interstitial lung disease Coeliac disease Liver cirrhosis

Answer 137

Idiopathic Cirrhosis Chronic liver disease Connective tissue diseases (rheumatoid arthritis, SLE) Pregnancy

Answer 138

Rate Rhythm Character

Answer 139

The liver (filtration system) The lungs

Answer 140

``` C chemistry H haemolotogy I immunology M microbology P pathology ```

Answer 141

A = foecal / oral B+C = blood

Answer 142

Pectus excavatum (hollowed chest) Pectus carinatum (pigeon chest)

Answer 143

Serous fluid (hydrothorax) Blood (haemothorax) Chyle (chylothorax) Pus (empyema)

Answer 144

Transudate = filtration out of capillaries due to high hydrostatic pressure.Low in protein (e.g. in heart failure) Exudate = high protein fluid caused by leeky capillaries.

Answer 145

Autograft = self Allograft = non-identical transplant Isograft = identical twin transplant Xenograft = animal transplant

Answer 146

Increase in blood viscosity Change in laminar blood flow (turbulence around junctions) Damage to arterial endothelium

Answer 147

Increase in juxtaglomerula pressure Release of renin, activating the RAAS system

Answer 148

Rupture of the neovascular supply Formation of the thrombus on the rough sruface of the plaque.

Answer 149

The dermis

Answer 150

``` Pain Palor Perishing Cold Pulselessness Parasthesia ```

Answer 151

Stenosis = narrowing Occlusion = totally blocked

Answer 152

Atherosclerosis Trauma Poly-cystic kidney disease Vasculitis

Answer 153

``` Arterial: "Punched out" Painful Usually on the medial malleolus Reduced leg pulses Pale Reduced leg hair ``` ``` Venous: Increased pigmentation (haemocidin) Usually on the anterior tibial aspect of the leg Red wound More irregular in shape ```

Answer 154

Sarcoma = mesodermal tissue Carcinoma = ectoderm and endoderm

Answer 155

``` Size Edge Depth Healing (granulation tissue) Infection Exudate ```

Answer 156

Tissue that forms when healing is taking place. "Capillary loops" Looks like granules

Answer 157

Nodular Nodular-cystic Superficial

Answer 158

Paired structures of the midline ``` Thyroid Lungs Breast Kidney Prostate ```

Answer 159

``` Anterior = pectorals major Posterior = latissimus dorsi Medial = serratus anterior Lateral = biceps ```

Answer 160

Fine needle aspiration = few cells Core biopsy Excisional biopsy

Answer 161

``` N = nodular A = amelonacytic S = superficial spreading A = acral L = lentiginous ```

Answer 162

The bodies response to a systemic infection. Can result in end organ damage

Answer 163

A cascade of cytokines and interleukins etc. the bodies response to large infection and the reason why a lot of infections can initially present in the same way. Sepsis --> septic shock --> multi-organ failure

Answer 164

1) Collagen in dermis 2) Lamella bodies in stratum granulosum and spinosum 3) Langerhans APCs in the epidermis, leucocytes in the dermis, constant shedding of stratum corneum 4) Capillaries in papillary dermis, sweat glands, thermoreceptors, adipose tissue 5) Basket cells at base of hair follicles, nociceptors, and mechanoreceptors (Meissners corpuscle) in dermal papillae, 6) Keratinocytes in the presence of UV light - liver and kidney required for active form conversion 7) Melanin in melanocytes - projections to protect keratinocytes 8) Stem cells in stratum basal, dermal collagen by fibroblasts.

Answer 165

Only difference is thickness of the stratum corneum. This is determined by the rate of mitosis of stem cells in the stratum basale. Thick skin is found in areas of the body which experience increased abrasive forces. e.g. soles of feet.

Answer 166

``` A = anaphylactic (peanut allergy) B = blood loss (trauma) C = cardiogenic (MI, cardiac tamponade) D = drug caused (penicillin allergy) E = endocrine (hypothyroidism) F = fluid loss (burn, D&V, etc) G = gram -ve sepsis (meningococcal septicaemia) ```

Answer 167

Reduced end organ perfusion leading to failure of that organ.

Answer 168

Hypoxia is simply a lack of oxygen. Ischaemia is a reduced blood supply to tissues leading to (among other things), hypoxia, toxin buildup, acidosis

Answer 169

Commonly in arteries which experience trauma from high blood pressure such as the aorta. Also common at junctions in arteries where turbulence in the blood is resultant. This is part of virchow’s triad of thrombotic factors.

Answer 170

An aneurism is an abnormal dilation of blood vessel or the heart. Congenital of acquired. True aneurism = intact, attenuated arterial wall False aneurism = defect in arterial wall leading to freely communicating extravascular haematoma. Arterial dissection = a tear in the tunica intima of the arterial wall leading to a haematoma between the intima and the media of the artery. This commonly occurs in the aorta and can run all the way to the heart. Literally ‘dissecting’ the two vascular layers.

Answer 171

Toxins = strep pyogenes, clostridium botulinum, cholera Intracellular = salmonella typhi, L. monocytogenes

Answer 172

Infectivity = A pathogens capacity for ease of horizontal transfer. Virulence = The ability of a microorganism to invade the tissues of the host (mediated by virulence factors) Infective dose = number or microorganisms required to cause an infection within the host

Answer 173

20 - 300nm Icosahedral (adenovirus) Filamentous (ebola) Spherical

Answer 174

Nucleic acid Capsid (both together = nucleocapisd) Possibly a lipid envalope Depending on the virus there may be another coat (p17 matrix in HIV) and enzymes, proteins etc.

Answer 175

ss DNA ds DNA ss RNA dsRNA ssRNA - retroviruses ds DNA - hepadnaviruses

Answer 176

Viral proteins (3 types = capsule proteins, enzymes, immune interference proteins) Viral nucleic acids

Answer 177

negative sense (antisense) = 3’ to 5’ = complementary to mRNA sequence positive sense = 5’ to 3’ = same as mRNA sequence Positive sense viruses have genetics that can be used as host mRNA directly. These viruses do not have to enter the nucleus. Negative sense viruses have genetics that must be converted to mRNA before it can be user for translation. These viruses have to enter the nucleus to use host RNA polymerase (can carry viral version)

Answer 178

New RNA = -ve —> +ve —> lots of -ve New proteins —> -ve —> +ve mRNA —> proteins

Answer 179

A fungal pneumonia, most commonly seen in immunocompromised HIV patients. It is an opportunistic infection that does not respond well to ant fungal treatments. On X-ray it can be distinguished by its relative sparing of the apices of the lungs.

Answer 180

``` The pathogen - Method of spread (vehicle born (water, food, blood), vector born, airborne) Virulence (high or low) Infectivity (high or low) Pathogenicity (recognisable?) ``` The environment Exposure (animals, behaviour, living quarters, hygiene, health, vector, sex) Host (age, gender, lifestyle, co-morbidities, duration, entry, immune state)

Answer 181

Outbreak =an epidemic limited to localised increase in incidence of a disease (town or school) Epidemic = the occurrence in a community of region of cases of an illness that exceeds normal expectations Pandemic = an epidemic occurring over multiple countries / large area

Answer 182

Aerosol = influenza Contact = herpes simplex, HPV Enteric = rotavirus Bloodborne = Hepatitis B Zoonotic = Dengue

Answer 183

As viruses in host cells, difficult to kill virus without harming host Viruses are organisms with short reproductive times and high mutation rates, therefore, resistance is common and quick.

Answer 184

Interferon —> 2 types, cause a localised antiviral state of reduced metabolism and apoptosis. Natural killer CD8+ T-cells Innate immune cells (macrophages, neutrophils)

Answer 185

Serous (pericarditis) Catarrhal (^ mucous secretion = common cold) Fibrinous (pericarditis) Haemorrhagic (pancreatitis) Purulent (empyema) Membranous (diphtheria) Pseudomembranous (colitis) Necrotising (gangrenous appendicitis)

Answer 186

Fever Malaise, anorexia, nausea Catabolism of muscle proteins = weight loss Leucocytosis Increased immunological plasma protein synthesis

Answer 187

A subtype of inflammation characterised by granuloma formation. Granulomas are a collection of macrophages that are used to ‘wall off’ a substance that is threatening but can’t be removed. Often giant cells are present = formed from the union of multiple macrophages.

Answer 188

Hepatitis B Influenza Pneumococcal disease

Answer 189

Measles Diptheria Polio Meningitis C

Answer 190

R0 is: the average number of 2˚ infections produced by an infective agent in a susceptible population does not fluctuate, not affected by vaccination depends on infectivity and population characteristics (density, hygiene, etc…) can differ between diseases or populations Can determine R from R0 (R = R x s). Where s is susceptible population. R = average number of 2˚ infections in entire population. R is the quantity that is influenced by mass vaccination. The more resistant, the fewer who can be infected If R >1 then the number of cases increases If R< 0 the number of cases decreases (1 is the epidemic threshold)

Answer 191

Heard immunity does not prevent people from acquiring the disease. It just prevents an outbreak/epidemic. It does this be keeping R <1.

Answer 192

Is the disease a public health problem? (cases, morbidity, mortality) Is immunisation the best strategy? (Are there other, better, options such as treating after the fact). Depends on: cost, safety, efficacy, practicality Will this new vaccine fit in with the current immunisation profile/timescale? How much disease will be prevented? What are the negative effects of the vaccine? (direct risk, errors, interference, shifting of susceptibility groups) What additional resources will be needed? Is this vaccine cost effective?

Answer 193

``` Things that cant be quantified. Personal opinion how people view their world what influences behaviour why people do the things they do ```

Answer 194

``` Population: develop heard immunity prevent the spread of illness protect vulnerable members of society possibly eradicate disease ``` ``` Individual: want to protect myself vaccines can cause disease vaccines can have adverse effects I may not be at high risk the disease may not be serious to me vaccines can make you feel slightly unwell ```

Answer 195

P. falciparum = malaria = mosquito vector T. brucei = african trypanosomiasis (sleeping sickness) = tsetse fly T. cruzi = chagas disease (megacolon) = triatomine bug Leishmania donovani = leishmaniasis = sandfly Toxoplasma gondii = toxoplasmosis = cats, pigs, sheep Schistosoma mansoni = schistosomiasis = sea snails

Answer 196

Doubling time of cells Fraction of cells that are replicating Rate at which the cells are shed/lost to reach 1g, cells must double 30 times. to reach 1kg, cell must double 40 times. So short (tumour dependant) window of opportunity to catch a tumour before it grows too large.

Answer 197

Metastasis and invasiveness

Answer 198

``` intestinal epithelial cells = 12h skin cells = 5d liver cells = 1y neurones = never cancer cells = 12-24h ```

Answer 199

codes for a protein which regulates the cell cycle in some way and prevents it replicating out of control or replicating with a mutation. These are commonly proteins that act at the checkpoints at the cell cycle. e.g. cyclins, CDK, p53, p21, p27.

Answer 200

Has 3 major functions which it mediated through 2 pathways. Causes gene transcription p21 which inhibits CDKs and causes G1 arrest. GADD45 which repairs DNA. Inhibits gene transcription anti-apoptosis BCL2 resulting in apoptosis. CDK4 inhibiting growth and resulting in senescence.

Answer 201

Flat discolouration of the skin. Cant be felt small, solid elevation of the skin, 5mm large blister >5mm small blister 2cm. Can form from a group of papules accumulation of thickened keratin - thick epidermis compressible patch of dermal oedema circumscribed area of skin loss (usually due to impaired vascular supply) prominence of normal skin markings extravasation of blood = red discolouration haemorrhage of the skin >2mm dried exudate on the skin surface superficial break in the epidermis superficial abrasion - due to scratching bening proliferation of a constituent of skin (including moles)

Answer 202

``` Breast (F) Prostate Lung Colorectal Bladder Uterine (F) ``` ``` Men = prostate then lung Women = breast then lung ```

Answer 203

``` Lung Colorectal Breast Prostate Pancreatic ```

Answer 204

``` Leukaemias Brain and CNS tumours Lymphomas Soft tissue sarcoma SNS tumours ```

Answer 205

``` Smoking Alcohol Salts H. pylori Obesity Hepatitis HPV Genetics (predisposition) ```

Answer 206

``` Exogenous UV light X-rays Chemical isotopes Endogenous Oxygen Water Reactive species Metabolic intermediates ```

Answer 207

Certain things can cause DNA mutations (UV light, oxygen radicles, etc.) These can disrupt the normal structure of DNA via: dimerisation, alkylation, mis-pairing, addition of reactive groups. Normally this damage leads to a build up of p53 and various mechanisms to prevent division: cell cycle arrest (p21), repair (GADD45), senescence and apoptosis. If this mechanism doesn’t work properly then the cell division can continue and mutations can be passed on to daughter cells.

Answer 208

A group of enzymes within the liver which break down toxic metabolites so they can be easily excreted. It forms an intermediate which a second process makes soluble. It is this intermediate which can damage DNA. p450 adds a highly reactive epoxide group which if not bound, can attack and damage DNA.

Answer 209

Tumour supressor and oncogenes are encoded on both chromosomes of the pair. Therefore, both have to be damaged to give the cancerous phenotype. A germline mutation causes a damage in one of these genes so only one more ‘hit’ is required to cause cancer rather than the usual ’two hits’. E.g. Retinoblastoma, familial adenomatous polyposis, ataxia telangiectasia, familial melanoma

Answer 210

Failure of signal transduction pathway (PDGFR) Failure of molecules within signal transduction pathways (RAS) Failure of tumour suppressor proteins (p53) Lots of other important mutations required (angiogenesis, evasion of apoptosis, telomerase, apoptosis failure, repair failure)

Answer 211

Commonly tyrosine kinase receptors (EGF, TGF-a, PDGF, insulin) Can be G-protein coupled to reduce intracellular cAMP Can be Jak/Stat where stat molecules cause DNA transcription. ALL THESE PATHWAYS INCREASE DNA TRANSCRIPTION

Answer 212

``` Surgeon Radiologist Pathologist Oncologist Palliative care Dr. Clinical nurse specialist Physiotherapist Occupational therapist Radiographer Psychologist Dietician Speech therapist Pharmacist ```

Answer 213

Provides assurance on accuracy Important 2nd opinions Gaining experience of management Ensuring high and constant of patient care Teaching for junior doctors Improves communication and, therefore, dissemination of knowledge.

Answer 214

Appearance (scaring, hair loss, weight change, skin damage, oedema) Function (colostomy and stoma, speech, hearing, infertility, memory loss) Sensation (numbness, walking, reduced activities of daily living)

Answer 215

Gives sense of self Gives indépendance Gives self recognition

Answer 216

``` Getting information Use of family and friends Setting goals Problem solving Being aware of thoughts Developing social skills Covering up changes Exercising Breaking -ve feedback cycle (thoughts —> feelings —> behaviour) ```

Answer 217

Before treatment Diagnosis During treatment End of treatment Survivorship Risk prevention

Answer 218

Anaphylaxis | Asthma, eczema, hay fever, dermatitis

Answer 219

Graves disease, pernicious anaemia, myasthenia gravis

Answer 220

Rheumatoid arthritis, nephritis, SLE

Answer 221

T1 diabetes mellitus, graft rejection

Answer 222

Iron deficiency Thalassaemia Sideroblastic Anaemia of chronic disease (usually normoblastic)

Answer 223

B12 or folate deficiency | Alcoholic liver disease

Answer 224

Aminoglycosides - Gentamycin, neomycin, tobramycin, streptomycin Carbapenems - Ertapenem, imipenem Cephlasporins - Cefotaxime Glycopeptides - Vancomycin Lincosamides - Clindamycin, lincomycin Macrolides - Clarithromycin, erythromycin Penicillins - Amoxicillin, ampicillin, flucloxacilin, penicillin V Quinolones - Ciprofloxacin, (floxacin) Sulfonamides - Sulfasalazine Tetracycline (tetracycline)

Block 9 Flashcards

(250 cards)