Block 40

Question 1

Non fusion of urethral folds

Answer 1

1. In females is normal —> vestibule vagina formation
2. In males it leads hypospadias. (Epispadias on the contrary is due to abnormal opening of the urethra on the dorsal surface of the penile shaft that results from faulty positioning of the genial tubercle in the fifth week of gestation.

Question 2

Poison ivy dermatitis

Answer 2

• its a form contact dermatitis.
• poison ivy,poison oak and poison sumac all produce urushiol, a small allergenic substances that causes an immune response when attached to proteins ( ie. heptan).
• following contact these plants, patients develop highly pruritic, erythmatous rash consisting of papules, vesicles, and bullae that may show signs of excoriation.
• the rash most frequently affected exposed skin and often forms linear streaks as the patients walks past the the plant, dragging it along the skin.
• contact dermatitis is a type IV hypersensitivity(delayed-type) reaction.
• CD8+ T cells are the primary effector cell and directly destroy keratinocytes expressing haptenated proteins.
• it occurs in 2 phases , senseitization phase and elication phase

Question 3

Sickle cell anemia mutation

Answer 3

Glutamic acid (negative) —

Question 4

Coal worker pneumoconiosis

Answer 4

• form of interstitial lung fibrosis secondary to long term inhalation of coal particles.
• inorganic dust is constantly being inhaled and must be cleared by the respiratory tract to prevent disease.
• the clearance mechanism used by the lung vary depending on the size of the particles. Larger particles become trapped by mucus secretion in the trachea, bronchi and proximal bronchioles, these trapped particles are swept upward toward the pharynx by the collective beating of cilated cells.
• the finest particles (eg coal) reach the repsiratory alveoli and bronchioles where they are phagocytozed by alveolar macrophages.
• engulfment of inorganic dust causes MAC activation and release of number of cytokines that induce pulmonary inflammation.
• GF,IGF and PDFG also released —> fibroblast proliferation and collagen production —> progressive interstitial lung fibrosis.

Question 5

MCL injury

Answer 5

• the MCL attaches proximal to the medial epicondyle of the femur and resists forces that push the knee medially. MCL injury typically occurs after twisting njury or blow to the lateral knee while the foot is planted (valgus stress injury).
• valgus stress test is performed with the knee extended by placing one hand along the lateral thigh and pressing inward while the other hand is placed on the medial aspect of the ankle and pushed outward.
• laxity of the knee and/or medial joint line widening indicates MCL injury.

Question 6

Clear cell carcinoma -RCC

Answer 6

• gross painless hematuria
• the patients biopsy will show round/polygonal cells with abundant clear cytoplasm which is characteristic for Clear cell carcinoma
• clear cell carcinoma originates from PCT epithelial cells and contains copious amounts of intracellular glycogen and lipids.

Question 7

Cystic degeneration of the putamen most commonly associated with

Answer 7

Willson disease

Question 8

Caudate nucleus is affected in

Answer 8

Huntingtons disease

Question 9

Hypertrophic obstructive cardiomyopathy is mutation in

Answer 9

Autosomal dominant disease of the cardiac myocytes caused by mutation of several sarcomere encoding gene encoding the myocardial contractile proteins.
-common mutation include single point mutations in the gene for beta-myosin heavy chain and myosin binding protein C.

Question 10

Vitamen E deficiency is present with what neruological deficits

Answer 10

1. Degeneration of posterior column
2. Degeneration of spinocerbellar tracts.
   (Friedrich ataxia like symptoms)

Question 11

What is the most important prognostic factor in tetrology of fallot

Answer 11

• RV outflow tract (RVOT). The amount of RVOT obstruction that determines how much deoxygenated blood cross the VSD to the aorta and to sytemic circulation —> more cyanosis
• infants with no or minimal RVOT obstruction,deliver more deoxygenated blood to the lungs and appear a-cyanotic.
• the obstruction degree is dynamic and certain changes such as dehydration or hyperventilation can lead to profound cyanosis “tet spells”)

Question 12

AML stain

Answer 12

Myeloblasts have large number of rod shaped intracytoplasmic granules called auer rods that stain for peroxidase.

Question 13

Dermatomyositis

Answer 13

-systemic autoimmune disease charactrized by proximal muscle weakness resembling plymyositis, but with additional inflammtory features involving the skin.
-skin findings include the heliotrope rash in the peri-orbital areas and cheeks along with gottron’s papules, which are raised erythmatous plaques over the joints and bony prominences of the hands.
-muscle biopsy is diagnostic and shows mononuclear perimysial infiltrates, perifascicular atrophy, and patchy necrosis.
-it may occur as a consequence of paraneoplastic syndrome of underlying malignancy. The most commonly associated cancers include ovarian, lung ,colorectal and nonhodgkin.
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Question 14

Clindamycin in alcoholics

Answer 14

• clindamycin: pulmonary infections in alcoholics commonly include anaerobic oral flora admixed with aerobic bacteria. Necrotizing infections and lung abscesses may result.
• if abscess is present, the best agent to be given is clindamycin as it covers against most anaerobes and also covers gram positive organism aerobes such as s.pneumoniae.
• it works primarily by attaching to the 50S ribosomal subunit in bacteria
• clindamycin usually is given for above the diaphragm anaerobic infections while metranidazole is given to below diaphragm infections.

Question 15

Ethosuxemide mechaism

Answer 15

Blocks thalamic T-type Ca+ channels

Question 16

Typhoid fever clinical manifestation

Answer 16

Week 1: rising fever, bacteremia, relative bradycardia
Week 2: abdominal pain, rose spots on trunk and abdomen
Week 3: hepatosplenomegaly, intestinal bleeding and perforation.
-commonly present with travel history, transmission fecal-oral.
-question most likely states watery diarrhea that became bloody after a week or so.
-salmonella able to penetrate the gut mucosa via phagocytosis by M cells and bacteria mediated endocytosis.
-bacteria survives in peyers patches —> severe inflammation and ensuing bacteremia —> pts develops fever with relative bradycardia followed by watery diarrhea or constipation, abdominal pain, and salmon colored rose spots on chest and abdomen.
-it can also cause hepatosplenomegaly.

Question 17

Drugs that affect the mast cells for asthma treatment

Answer 17

1. Omalizumab : anti IgE antibody.prevent binding of IgE to mast cells.
2. Glucocorticoids: prevent gene transcription of phospholipase A2 synthesis
3. Cromoglycates: inhibit mast cells degranulation and prevent release of preformed chemical mediators. They are typically used to prevent acute attacks.these are effective prophylactic agents for patients with seasonal symptoms, aspirin hypersensetivity and execise induced asthma.
4. Zafirleukast and monteleukast: are LTD4 receptor antagonist. These agents are typically agents are typically used for chronic asthma prophylaxis.
5. zileuton: selective inhibitor of the lipoxygenease pathway that leads to decreased formation of leukotrines

Question 18

Acetazolamide

Answer 18

Diuretic that works by inhibiting the enzyme carbonic anhydrase. Its found in high concentration in the PCT and is responsible for catalyzing the reactions necessary for NaHCO3 reabsorption.

• carbonic anhydrase is also present in the eyes, pancreas, GI tract,CNS and RBC.
• in eye tissues, Carbonic anhydrase modulates HCO3 formation in the aqueous humor. —> inhibition can be used in glaucoma treatment.
• side effect of it is somnolence, paraesthesias and urine alkalization.

Question 19

Anastrozole, letrozole,exemstane

Answer 19

Aromatase inhibitors used in breast cancer

Question 20

Major muscles for motion of the hip

Answer 20

Flexion: iliacus muscle and psaos major (the most) rectus femoris, and tensor fascia lata
Extension: gluteus maximus, semitendenosus, semimembronosus, biceps femori long head
Abduction: gluteus medius and minimus
Adduction : adductor brevis, adductor longus and adductor magnus.
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Question 21

Infarction secondary to atrial thrombi embolism is unlikely in which organ

Answer 21

-infarcts to the liver is relatively rare because of the dual blood supply from portal vein and hepatic artery

Question 22

Generalized epliepsy treatment

Answer 22

Broad specturm :

1. Lamotrigine
2. Levetiractem
3. Topiramate
4. Valproic acid.