November, 2010 | Master Of Medicine

Monthly Archives: November 2010

Important points

Pancytopenia with increased MCV- megaloblastic anemia.

Valveless veins are IVC,common iliac vein,Portal venous system,Cranial sinuses

Opthalmic artery is a branch of cerebral part of ICA and meningeal artery is br of cavernous part of ICA.

Gibbs Donnan equilibrium is between univalent anion cation pair ie [Ka+][cla-]=[kb+][clb-]

Normal cerebral perfusion pressure is 80-100mmhg, cerebral blood flow is autoregulated between 60-160mmhg of CPP.

Pulmonary arteries and arterioles constrict in response to hypoxia so that blood flow to better oxygenated alveoli increase.Vasoconstriction mediated by K+ gated channels.

Strech reflex mediated by muscle spindle and inverse stretch reflex is mediated by golgi tendon organ.

Reciprocal innervation is relaxation of antagonistic muscles when strech reflex occurs mediated by golgi bottle neurons(inhibitory interneurons)

Alpha motor neuron stimulation cause muscle contraction,golgi tendon organ cause alpha motor neuron inhibition.

Insulin activates pyruvate dehyrdogenase leading to production of Acetyl CoA needed for fattyacid synthesis.

Insulin decreases intracellular cAMP and thus inhibits lipolysis in adipose tissue.

Important points

  • Sclera is thickest at the posterior pole near the optic nerve
  • Sclera is thinnest just behind the insertion of superior rectus.
  • Internuclear opthalmoplegia(INO) is a disorder of conjugate lateral gaze characterized by impaired horizontal eye movement with weak adduction of ipsilateral eye and abduction nystagmus of contralateral eye.

Absolute indication for termination of pregnancy are-

  1. Primary pulmonary hypertension
  2. Eisenmenger syndrome
  3. Pulmonary veno occlusive disease
  • Trisomy 18 is associated with greatest chance of abortion among trisomies(74%)
  • Fishy odour and clue cells give clue of Bacterial vaginosis,doc is metronidazole.
  • Mayer Rokitansky kuster hauser syndrome consists of vaginal aplasia with other mullerian abnormalities.
  • Ovaries are unaffected in Mayer Rokitansky syndrome because they are developed from primitive ectoderm(genital ridge)
  • Chorionic villous biopsy can be carried out transcervically from 10-12 weeks and transabdominally from 10 weeks to term
  • Two important causes of hip pain in children are transient synovitis and septic arthritis, septic arthritis is due to infection whereas transient synovitis is due to immune reaction triggered by bacterial antigens.
  • Tarsal tunnel syndrome commonly associated with rheumatoid arthritis.
  • Double bubble sign is characteristic of duodenal atresia, first bubble is due to dilated stomach and second bubble due to duodenum.
  • Double bubble sign can also be due to duodenal stenosis,duodenal webs,annular pancreas,malrotation of gut due to midline volvulus/ladd bands,preduodenal position of portal vein.
  • Peyronies disease is also called penile fibromatosis.

HS purpura is characterized by tetrad of

  1. purpura
  2. arthritis
  3. Glomerulonephritis
  4. Abdominal pain
  • Zona glomerulosa -minerallocorticoid
  • Zona fasciculata- Glucocorticoid
  • Zona reticularis-Sex corticoid.
  • Carolis disease is type V cholidochal cyst.
  • Clomiphene citrate is a weak estrogen agonist so it acts as estrogen antagonist in the presence of estrogen.
  • High frequency hearing loss is due to ototoxic medications,high frequency audiometry is used to isentify hearing loss due to ototoxic drugs.

Rhomberg test tests:

  1. Joint position sense(proprioception)
  2. Vision
  3. Vestibular apparatus

If any two of the above is working rhombergs test is negative.

Cephalosporins

First generation

Parenteral: Cephalothin,cefazolin
Oral: Cephalexin,cefadroxil,cefaridine
Acts on gram positive cocci

Second generation

Parenteral: Cefuroxime,cefoxitin
Oral: Cefaclor,Cefuroxime

Most active against gram negative organisms

cefuroxime higher CSF concentration

Third generation

Parenteral: Cefotaxime,ceftizoxime,ceftriaxone,ceftazidime,cefoperazone

Oral: Cefixime,Cefpodoxime,cefdinir

Highly active against gram negative enterobacteriacea

Ceftyazidime and cefoperazone antipseudomonal

ceftazidime+aminoglycoside-TOC for pseudomonas

Forth generation

Parenteral: cefepime,Cefpirome.
No oral agents.

General properties

  1. Cephalosporins excreted primarily by kidney require dose reduction in renal impairment
  2. Cefpiramide,ceftriaxone,cefoperazone excreted predominantly by bile.
  3. Cefotaxime,ceftriaxone,cefepime useful in meningitis(penetrate BBB)
  4. No cephalosporins active against Enterococcus fecalis,MRSA,listeria
  5. Cephaloridine-Most nephrotoxic cephalosporin
  6. Disulfuram like reaction- Cefamandole,cefotetan,cefoperazone.

Important parasites

Parasites causing malabsorption in adults

  1. Giardia Lamblia
  2. E.Histolytica
  3. H.Nana
  4. Strongyloides
  5. Cyclospora

Malabsorption in children

  1. G.Lamblia
  2. Isospora belli
  3. Cryptosporidium
  4. Ancylostoma duodenaLE
  5. E.Histolytica
  6. Capillaria phillipinensis

Man is the defenitive host in most parasitic infections except in:

  1. Echinococcus granulosus
  2. Plasmodium
  3. Taenia Solium(man is both defenitive and intermediate host)
  4. Toxoplasma gondii
  5. Sarcocytis lindemanii

Parasites causing autoinfection

These organisms establish life cycle within the same host eliminating the need for other hosts

  1. Capillaria philippinensis
  2. Cryptosporidium parvum
  3. Enterobius vermicularis
  4. Hymenolepis Nana
  5. Strongyloides stercoralis
  6. Taenia solium

Worms which do not multiply in man

  1. A.duodenale
  2. E.vermicularis
  3. W.bancrofti

Clonorchis sinensis

  1. Man is the defenitive host and snail secondary host in clonorchis sinensis
  2. Infection caused by ingestion of metcercaria
  3. Mature in bile canaliculi
  4. c/c infection associated with cholangitis,cholangio hepatitis and biliary obstrucion.

Dimorphic fungi

Can grow either as yeast or as mould depending on env conditions and temperature

Usually yeast at body temperature(37C) and as filamentous forms at room temperature(27C)

  1. Blastomycetes
  2. Paracoccidiomyces
  3. Blastomyces
  4. Sporothrix
  5. Candida albicans(not other candida)
  6. Histoplasma capsulatum
  7. Penicillin marneffi

ACE inhibitors

All ACE inhibitors except captopril and lisinopril are prodrugs

Enalapril—->Enalaprilat

Enalapril has a half life on 1.3 hours only but enalaprilat has a halflife of 11 hours

Lisinopril is lysine analogue of enalapril with half life of 12 hours.

All ACE inhibitors are cleared as intact compound by kidney except fosinopril and moexipril.

Alkylating agents

  1. Transfer alkyl groups to various cellular constituents causing cell death.
  2. Alkylating agens—->cyclization—->Immonium ion/cabonium ion—–>transfer alkyl group.
  3. Major site of alkylation is N7 position of guanine with DNA.
  4. There are five major categories of alkylating agents.

Nitrogen mustards

  1. Cyclophosphamide
  2. Mechlorethamine
  3. Chlorambucil
  4. Melphalan
  5. Ifosfamide

Nitrosoureas

  1. Carmustine
  2. Lomustine
  3. Semustine

Ethylenimines

  1. Thitepa
  2. Triethylethenilamine

Alkyl sulfonate

Busulfan

Platinum compounds and Methylhydrazine groups are also added to alkylating agents

Platinum compounds

  1. Cisplatin
  2. Oxaliplatin
  3. Carboplatin
  4. Nedaplatin

Methyhydrazine

  1. Procarbazine
  2. Altretretamine

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