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

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 . 

116 - hypoglycemia causes list

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)

Tuesday, May 6, 2008

115 - osteoporosis causing drugs

1. drugs causing osteoporosis are :

a- vitamin K
b- lithium
c- dilantin
d- heparin
e- etidronate

answer : b , c , d . lithium, dilantin and heparin . dilantin is the other name of the anti-epileptic drug phenytoin . etidronate is used in the treatment of osteoporosis .

-the drugs that cause osteoporosis are : ( GHALACTose)

1. glucocorticoids, GnRH antagonists
2. heparin
3. anticonvulsants, aluminium,
4. lithium
5. alcohol excess intake
6. cyclosporine, cytotoxic drugs
7. thyroxine excess

Subscribe Now: Feed

You are visitor number

Visitors currently online