Medicine Mcqs Postgraduation preparation: May 2008

In the upsc prelims medical sciences paper on may 18 2008, a match the following question was asked regarding the types of hypersensitivity reactions :

MATCH THE FOLLOWING :

A) TYPE 1 1. auto immune hemolytic anaemia

B) TYPE 2 2. contact dermatitis

C) TYPE 3 3. atopic form of bronchial asthma

D) TYPE 4 4. systemic lupus erythematosus

ANSWER : A3 B2 C4 D1 .

This is very important so just go through the list of hypersensitivity reactions and how they are classified . below . mediators included .

Type 1 hypersensitivity : Allergy
Atopy
Anaphylaxis
Asthma
IgE ( mediator )

type 2 hypersensitivity : Cytotoxic, antibody-dependent
erythroblastosis fetalis
Goodpasture's syndrome
autoimmune hemolytic anemia
IgM or IgG ( mediator )
(Complement)

type 3 hypersensitivity : Immune complex disease
Serum sickness
Arthus reaction
SLE
IgG ( mediator )
(Complement)

Type 4 hypersensitivity : cell-mediated
contact dermatitis
tuberculosis
Chronic transplant rejection
Cell-mediated

see post numbers 168,169,170,171 for the complete list of conditions associated with type 1,2,3,4 hypersensitivity reactions .

Recently there was a question in the medical sciences paper of the UPSC prelims examination conducted on 18 may 2008 regarding hypoglycemia. Let us look into this question. The question was as follows :

Which of the following conditions is associated with hypoglycemia?

a- VIPoma

b- Phaeochromocytoma

c- Fibrosarcoma

d- Glucaganoma

The answer is : c . fibrosarcoma . surprised ? I was too , but this is the answer , because all the other three do not cause hypoglycemia and only fibrosarcoma causes hypoglycemia. Check out the tumors that cause hypoglycemia and also all the other causes that cause hypoglycemia. I know it is an exhaustive list but read once so that atleast a few of them will remain in ur brain .

Extrapancreatic Tumors

Mechanisms

Increased utilization by large or active tumor
Cachexia and depletion of glycogen reserves
Insulin-like peptides, especially IGF-II (Doege-Potter syndrome)
Inhibited hepatic gluconeogenesis or glycogenolysis
Blunted counterregulatory hormone responses
Autoimmune (see below)

Tumors associated with hypoglycemia

Benign and malignant mesothelioma
Neurofibroma
Fibrosarcoma
Rhabdomyosarcoma
Leiomyosarcoma
Liposarcoma
Sarcomatous dysembryoma
Reticulum cell sarcoma
Hemangiopericytoma
Spindle cell sarcoma
Pseudomyxoma peritonei (Rosenfeld syndrome)
Hepatoma (Nadler Wolfer Elliott syndrome)
Adrenal carcinoma (Anderson syndrome)
Non-islet pancreatic carcinoma
Hypernephroma
Adenocarcinomas of prostate, colon, bile duct, breast, stomach
Simple fibroma
Leukemia
Lymphomas and Hodgkin's disease
Multiple myeloma
Wilms' tumor
Apudoma
Carcinoid tumors
Pheochromocytoma (especially after removal)
Melanoma
Teratoma
Neuroblastoma
Paraganglioma

Causes of Transient Neonatal Hypoglycemia

Prematurity
Intrauterine growth retardation

Smaller of twins

Severe infant respiratory distress syndrome
Maternal toxemia
Perinatal asphyxia
Critical illness

Starvation, Inadequate Intake Or Absorption

Fasting, e.g. preoperative
Severe malnutrition
Kwashiorkor
Anorexia nervosa
Pyloric stenosis
Vitamin B6 (pyridoxine) deficiency
Biotin deficiency
Hypomagnesemia
Diarrhea
Renal glycosuria
Combined intestinal monosaccharide transport defect

Major Organ Failure & Critical Illness

Congestive heart failure
Cyanotic congenital heart disease
Renal failure, especially chronic

Dialysis

Central nervous system disorders

Head trauma
Stroke
Severe encephalopathies
Hypothalamic tumor

Liver disorders

Severe acute hepatitis due to infection or toxins
Chronic liver failure
Reye's syndrome
HELLP syndrome (hemolysis, elevated liver enzymes, thrombocytopenia)

Chronic pancreatitis
Sepsis
Hypothermia
Malignant hyperthermia

Hyperinsulinism

Hypoglycemia due to endogenous insulin

Congenital hyperinsulinism

Transient neonatal hyperinsulinism

Due to maternal factors

Maternal diabetes
Erythroblastosis fetalis
Excessive intravenous glucose during labor
Maternal sulfonylurea
Sympathomimetic tocolytic agents (e.g. ritodrine)

Due to infant factors

Intrauterine growth retardation
Perinatal asphyxia
Idiopathic transient hyperinsulinism

Iatrogenic

Malposition of umbilical catheter

Focal congenital hyperinsulinism

Paternal SUR1 mutation with clonal loss of heterozygosity of 11p15
Paternal Kir6.2 mutation with clonal loss of heterozygosity of 11p15

Diffuse congenital hyperinsulinism

Autosomal recessive forms

SUR1 mutations
Kir6.2 mutations

Autosomal dominant forms

Glucokinase gain-of-function mutations
Hyperammonemic hyperinsulinism (glutamate dehydrogenase gain-of-function mutations)
Loss of heterozygosity of 11p15 (Beckwith-Wiedemann syndrome)

Donohue syndrome (leprechaunism)

Acquired tumors and hyperplasias of pancreatic beta cells

Islet cell adenoma
Islet cell carcinoma
Multiple endocrine adenomatosis syndrome
Pluriglandular syndrome of islet, pituitary, parathyroid hyperplasia

Autoimmune insulin syndrome
Reactive hypoglycemia (postprandial hypoglycemia syndrome)
Dumping syndrome

Drug induced hyperinsulinism

Oral hypoglycemic agents, especially Sulfonylureas

Treatment of diabetes
Treatment of diabetes insipidus
Ingestion by child

Aspirin overdose
Acetaminophen overdose
Pentamidine
Quinine
Disopyramide
Bordetella pertussis vaccine or infection

Hypoglycemia due to exogenous (injected) insulin

Insulin self-injected for treatment of diabetes

Excessive insulin dosage or accelerated absorption
Excessive activity
Inadequate food or delayed or decreased absorption
Alcohol
Drugs which contribute synergistically
Development of concurrent disease
Acquired endocrinopathies
Renal, cardiac or liver failure

Factitious & malicious insulin injection

Insulin self-injected surreptitiously (e.g., Munchausen syndrome)
Munchausen by proxy

Insulin tolerance test for pituitary or adrenergic response assessment
Treatment of hyperkalemia
Insulin potentiation treatment (cancer quackery)
Insulin-induced coma for depression or psychosis treatment (insulin shock)

Hormone Deficiencies

Cortisol

Addison's disease (acquired adrenal destruction)
ACTH deficiency
ACTH unresponsiveness
Congenital adrenal hypoplasia
Congenital adrenal hyperplasia

Growth hormone

Isolated growth hormone deficiency
Laron dwarfism (GH unresponsiveness)

Epinephrine and catecholamines

Adrenomedullary unresponsiveness

Glucagon
Combined deficiencies

Congenital hypopituitarism (various causes)
Psychosocial deprivation syndrome (hypothalamic)
Thyroid hormone (depresses GH and ACTH)

Metabolic Defects

Defective glycogenolysis or glycogen accumulation

Glucose-6-phosphatase deficiency (glycogenosis type I, von Gierke dis)
Pseudoglycogenosis type I
Amylo-1,6-glucosidase (debrancher) deficiency (glycogenosis type III)
Hepatic phosphorylase deficiency (glycogenosis type VI)
Hepatic phosphorylase kinase deficiency (glycogenosis type IXb)
Glycogen synthase deficiency (glycogenosis type 0)

Galactose-1-phosphate uridyl transferase deficiency (galactosemia)
Defects of gluconeogenesis or substrate supply

Fructose-1,6-diphosphatase deficiency
Isovaleric acidemia
Hypoalaninemia
Phosphoenolpyruvate carboxykinase deficiency
Pyruvate carboxylase deficiency (Leigh syndrome)
Fructose-1-phosphate aldolase deficiency

Defects of mitochondrial beta-oxidation and fatty acid metabolism

Systemic carnitine deficiencies

Enzyme deficiencies
Carnitine palmitoyltransferase I
Carnitine palmitoyltransferase II
Carnitine acyltransferase

Butyryl CoA dehydrogenase
Hydroxymethylglutaryl CoA lyase
Methylcrotonyl CoA carboxylase
Medium chain acyl CoA dehydrogenase
Short chain acyl CoA dehydrogenase
Long chain acyl CoA dehydrogenase
Multiple acyl CoA dehydrogenase (glutaric aciduria type II)
Long-chain 3-hydroxyacyl-CoA dehydrogenase
Short-chain 3-hydroxyacyl CoA dehydrogenase
Carnitine/acylcarnitine translocase

Enoyl CoA hydratase
Ketothiolase
Succinyl CoA:acetoacetate transferase
Defects of amino acid metabolism

Maple syrup urine disease
Methylmalonic acidemia
[[hydroxy-methylglutaric aciduria]]
Tyrosinosis
Phenylketonuria
Propionic acidemia

Miscellaneous metabolic defects

Defective type I glucose transporter in brain
Methylglutaconic aciduria
Sucrosuria
Glycerol intolerance
Rare variants of galactose intolerance
Other rare or poorly defined congenital metabolic defects

Drugs And Toxic substances

Insulin, antidiabetic agents (see above)
Drugs associated with hypoglycemia alone

Ethanol
Beta blockers, e.g. propranolol
Salicylates
Acetaminophen
Acetazolamide
Aluminium hydroxide
Chloroquine
Chlorpromazine
Cimetidine, ranitidine
Diphenhydramine, other antihistamines
Propoxyphene
Disopyramide
Doxepin
Golytely (in distal intestinal obstruction syndrome of cystic fibrosis)
Imipramine
Indometacin
Isoxsuprine
Insulin-like growth factor 1
Lidocaine
Lithium
Pentamidine
Propranolol, nadolol, labetalol, metoprolol
Orphenadrine
Oxytetracycline
Quinine, quinidine
Perhexiline
Ritodrine
Haloperidol
Chelating agents (BAL and EDTA)
THAM
Colchicine
Para amino benzoic acid, para-amino salicylic acid
Cholestyramine added during glucocorticoid therapy (reduces absorption)

Drugs which lower glucose in diabetics

Enalapril and captopril
Coumarin
Phenylbutazone
Antihistamines
Sulfa antibiotics, including SMX/TMP (especially in renal failure)
Monoamine oxidase inhibitors
Medicines not available in U.S.

Azapropazone, buformin, carbutamide, cibenzoline, cycloheptolamide, glibornuride, gliclazide, mebanazine, metahexamide, perhexiline, sulphadimidine, sulphaphenazole, Nigerian cow urine medicine

Environmental toxins

Amanita phalloides toxin
Abractylis gummifera (Mediterranean plant)
Hypoglycin from unripe Ackee fruit (Jamaican vomiting illness)
Parathion
Vacor rat poison

Idiopathic And Miscellaneous

Ketotic hypoglycemia

Identifiable hormone and enzyme deficiencies

Idiopathic

Idiopathic hypoglycemias, etiologies undetermined
Autoimmune
Antibodies to insulin
Antibodies to insulin receptor
Stimulating antibodies to islet cells
Thyrotoxicosis (extremely rare)
Infection

Mumps
Varicella
Pertussis
Measles
Malaria

Extreme exercise
Artifactual

In vitro glucose consumption after blood drawing
Leukemic WBC's may consume glucose in vitro
Polycythemia of infancy (RBCs consume glucose in vitro)
Inaccuracies of blood drop strips
Inherent variation inaccuracy at low end
Inadequate drop
Excessive wiping
Short time interval

Reactive, Functional, Postprandial, Etc.

Prediabetes (both categories controversial & may not be valid)

Juvenile diabetes (rare, anecdotal reports)
Adult onset diabetes (in early stages)

After intravenous glucose load
Abrupt discontinuation of parenteral nutrition or i.v. glucose
After exchange transfusion with ACD preserved blood in neonate
Alimentary (rapid jejunal emptying with exaggerated insulin response)
Post fundoplication for gastroesophageal reflux
Post gastrectomy dumping syndrome
Short bowel syndrome
Idiopathic gastrointestinal motility disturbance
Alternate day growth hormone therapy
Idiopathic reactive or postprandial hypoglycemia (hypoglycemia documented at time of symptoms: rare)
Idiopathic postprandial syndrome (hypoglycemia never documented: common)

Monday, May 26, 2008

118 - anion gap basis - metabolic acidosis causes

The causes of a metabolic acidosis can be classified on the basis of a normal or elevated anion gap.

An elevated anion gap is created by inorganic (eg, phosphate or sulfate), organic (eg, ketoacids or lactate), or exogenous (eg, salicylate) acids incompletely neutralized by bicarbonate. Frequent causes of an elevated anion gap metabolic acidosis is represented by the mnemonic MUDPILES:

· Methanol

· Uremia

· Diabetic ketoacidosis

· Paraldehyde

· Iron, isoniazid (INH)

· Lactic acid

· Ethanol, ethylene glycol

· Salicylates

A normal anion gap metabolic acidosis occurs when loss of bicarbonate from the GI tract or kidneys is excessive or when hydrogen ions cannot be secreted because of renal failure. The causes can be represented by the mnemonic USEDCRAP:

· Ureterostomy

· Small bowel fistula

· Extra chloride

· Diarrhea

· Carbonic anhydrase inhibitors (eg, acetazolamide)

· Renal tubular acidosis

· Adrenal insufficiency

· Pancreatic fistula

Tuesday, May 20, 2008

117 - Hypersensitivity reactions with examples

116 - hypoglycemia causes list