Diseases and others... Flashcards
In what conditions should amyloidosis be considered as a differential?
Nephrotic syndrome
Cardiomyopathies
Peripheral neuropathies
What are the effective management strategies in allergy?
Avoidance of the allergen
Antihistamine - H1 receptor antagonist - Cetirizine
Corticosteroids - hydrocortisone/prednisolone
Omalizumab = monoclonal antibody vs. IgE
Adrenaline = for anaphylactic shock
What are the most common allergens?
Insect stings
Latex
Food allergies
Drugs
What is the most common cause of non IgE mediated mast cell degranulation?
Drug allergy
What are the clinical manifestations of anaphylaxis?
Tachycardia Hypotension Urticaria Wheeze and broncho-constriction Stridor Flushing and sweating Itching on palms of hands and soles of feet
What is the difference between non pitting and pitting oedema?
Pitting oedema occurs in organ failure (heart, liver kidney) when the plasma oncotic pressure is too low to draw water back into the blood vessels by osmosis = transudate.
Non-pitting oedema is mainly caused by lymphoedema/angioedema when the interstitium fills with solutes and attracts water out into the interstitium = exudate.
What are the different classifications of transplant rejection and their treatments?
Hyperacute rejection = 30 days = minimise drug toxicity and control hypertension.
What is the MOA of the main anti-rejection drugs.
Anti-proliferative agents:
Azathioprine = inhibits lymphocyte proliferation by blocking DNA synthesis
Calcineurin inhibitors:
Cyclospoirn/Tacrolimus = Blocks T-cell signalling to prevent lymphocyte proliferation and block cytokine transcription. Calcineurin up regulates Il2 = T-cell proliferation.
Corticosteriods:
Betamethazone/prednisolone = decreases inflammatory and immune related proteins by down-regulating gene transcription
What is the mechanism of increasing T-cell and Ig affinity during an infection?
Somatic (VDJ) recombination
The VDJ genes are all part of the variable region of the future antibody. There is also a constant gene which codes for the constant regions of the antibody.
Recombination = removing the introns between the V, D and J segments, bringing them closer together with removal of unwanted segments of each (VDJ) to change the final variable site of the Ig to increase affinity.
What are the protective mechanisms of the body in a hot and cold environment?
COLD:
Shivering
Peripheral vasoconstriction
Behavioural changes
HOT: Peripheral vasodilation Behavioural changes Decreased muscle activity and lethargy Sweating to increase evaporative heat loss
What is hypothermia?
Who is at risk?
What are the main clinical features?
When the body is unable to maintain a core temperature above 35˚C due to extreme cold.
Extremities of age are most at risk. Babies = high surface area to volume ration. Elderly = co-morbidities and reduced protective measures.
Mild hypothermia = confusion, cold extremities, dehydration, shivering.
Severe hypothermia = reduced consciousness, stiffness, failed vasoconstriction, bradycardia, hypotension
Can progress to coma and death but resuscitative measures should be undertaken until ‘warm and dead’ as severe cold can prolong a near-death state.
What are the common heat illnesses ranging from least to most severe?
Heat cramp = vigorous exercise and profuse sweating in hot weather with no rise in core temperature. Made worse by replacing water but not salts.
Heat syncope = Faint caused by severe peripheral vasodilation and drop in peripheral resistance in hot weather.
Heat exhaustion = Inadequate salt and water replacement with raise in body temperature 40˚C. Failure of thermoregulatory systems and can lead to death. heat exhaustion + (N+V, confusion, muscle tremor, aggression, loss of conscousness). Treated with fluid replacement and rapid cooling.
Describe the basic hormonal mechanisms for the control of hunger.
Hunger:
Stomach –> ghrelin –> hypothalamus –> neuropeptide Y –> hunger
Satiety:
Pancreas –> insulin
Intestines –> GLP-1, peptide YY, polypeptides
Adipose tissue –> leptin
–> hypothalamus –> decrease NPY –> satiety
What are the complications of diabetes?
Coronary heart disease Stroke Diabetes Hypertension Non-alcoholic steatohepatitis Cirrhosis Exertional dyspnoea Sleep apnoea Respiratory failure Osteoarthritis Varicose veins Breast and uterus cancer Polycystic ovary syndrome Gall stones Colorectal cancer Skin infections Psychological problems
What is metabolic syndrome?
Type 2 diabetes
Hypertension
Hyperlipidaemia
Obesity
What are some of the reasons for the increasing prevalence of obesity?
Increased portion sizes Snacking, loss of regular meals Increase in energy dense food Increased affluence Increased use of cars Less walking More automation and less manual labour Less sports in schools Computing increase Increased central heating?
What are some of the potentially reversible causes of weight gain?
Hypothyroidism
Cushing’s
Insulinoma
Hypothalamic tumours
Drugs - Tricyclic antidepressants Sulphonylureas Contraceptive pill (oestrogen containing) Corticosteroids Sodium valproate Beta blockers
What management is available for obesity and what are the BMI cut offs?
Surgery = 40 w/o co-morbidity, 35 with
Drugs (orlistat, sibutramine) = 30 w/o cormorbidity, 27 with.
Below this = low calorie diet and improve eating behaviour, exercise and treat risk factors for disease.
What are the two main drugs used for weight loss?
Orlistat = pancreatic lipase inhibitor causing non-absorption of fats and excretion = severe steatorrhea = behaviour modifying drug.
Sibutramine = 5HT3 receptor agonist to decrease appetite for food. Nor-adrenergic side effects make this drug less desirable in obese patients so is 2nd line to orlistat.
What are the main forms of bariatric surgery?
Banded gastroplasty to permanently decrease stomach size.
Gastric banding to reversibly control stomach size and restrict intake.
Rue en Y gastric bypass to maintain passageway for pancreatic enzymes.
What is the main consequence of vitamin A deficiency?
Blindness - mainly in children in the developing world
What are the consequences of vitamin D deficiency?
Rickets in children
Osteomalacia in adults
