Block 19

Question 1

Celiac disease
Presentation
Diagnosis
Biopsy results

Answer 1

Presents between ages of 6-24 months after introduction of gluten into diet and with symptoms of malabsorption.

• other manifestation include delayed puberty and short stature in children and anemia in adults.
• screening is with serology testing for elevated IgA anti endomysial and anti tissue transglumainase and confirmed by biopsy (villous atrophy, crypt hyperplasia and inraepethilial lymphocytes infiltration) .

Question 2

H.pylori associated antral gastritis is usually seen as

Answer 2

Chronic antral inflammation leads to decreased in number of somatostain producing cells —> somatostatin is a hormone that inhibits gastrin release. In its absence high gastrin levels acts to increased HCL by parietal cells —> dudenal ulcer.

Question 3

Antigenic drift

Answer 3

Refers to point mutation in HA and NA genes that slightly alters the product protiens, allowing them to evade immune recognition and possibly increasing infectivity of the virus.
-However a changes in species to species transmission likely represent a major modification in protein structure that is better explained by RNA segment ressorment

Question 4

Reassortment (antigenic shift)

Answer 4

When 2 distinct influenza strains attack one cell. For instance a human influenza virus and birds influenza virus , can lead to human HA and birds NA being packed in the same virion. —> this can lead to novel strain of virus which human are susceptible but have no immunologic resistance. (This phenomenon is responsible for all pandemics and epdimics of infleuenza A )

Question 5

Most common cause of spontaneous intracranial hemorrhage in young adults is

Answer 5

AV malformation, ruptured cerebral aneurysm(its highly associated with coarctation of aorta due to high BP ) or cocaine abuse

Question 6

Leukocytes extravasation(depends on)

Answer 6

1. Margination and rolling : (E-selecting, P-selectin, glyCAM-1, CD34)
2. Tight binding : (I-CAM-1, VCAM- 1)
3. Transmigration: (PECAM-1)
4. Margination (chemotaxis )

Question 7

Hepcidin is

Answer 7

An APP, synthesized by the liver and act as a central regulator of iron hemostasis.

• high iron levels and inflammatory conditions increase the synthesis of hepcidin.
• hypoxia and increased erythropoiesis decreases hepcidin levels.

Question 8

Locus ceruleus

Answer 8

Paired “pigmented” brianstem nucleus, located in the posterior rostal pons, near the lateral floor of the 4th ventricle.

• its the principal site for NE synthesis in the brain and projects virtually all parts of CNS.
• its associated with mood control, arousal , sleep-wake state and autonomic function (BP).
• patietns with bilateral pontine hemorrhage typically present with coma due to disruption of the reticular activating system. Other features usually include total paralysis with extensor posturing due to corticospinal and corticobulbar tract injury and pinpoint pupils secondary to descending symphatetic tract damage,

Question 9

Histamine and orexin origin

Answer 9

Hypothalamus, they play important role in arousal and wakefulness.

Question 10

Dynorphin found >

Answer 10

Its opoid peptide that modulate pain response. Its produced mostly in the periaqudutal gray, rostal ventral medulla, and dorsal horn of spinal cord.

Question 11

Dopamine produced in

Answer 11

Ventral regmental area and substancia nigra pats compacta located in midbrain.
-major dopaminergic pathways in the brain include the mesolimbic and mesocrtical pathways.

Question 12

What carpal bone is usually affected in carpal tunnel syndrome

Answer 12

Lunate

Question 13

DNA methylation

Role in diseas

Answer 13

DNA methylation refers to addition of methyl groups to nucleotides residues(often adenine and cytosine) by DNA methyltransferase, an enzyme that uses S-adenosyl-methionine as the methyl group donor.

• fragile X syndrome —> increased CGG repeates —>hypermethylation of cytosine residues and FMR1 inactivation.
• cytosine methylation is also found in imprinting in which only one parental chromosome is presented (e.g parder willi syndrome , angelmansyndrome.)

Question 14

Copper reducation test can detect

Answer 14

Presence of reducing sugar, is positive in fructokinase deficiency.

Question 15

Maple syrup urine disease

Answer 15

• defective breakdown of branched chain amino acids (leucine, isoleucine and valine).
• mutation leads to accumulation of branched chain AA—> neurotoxicity —> seizures, irritability, lathergy and poor feeding.
• some patients may benefit from high dose “thiamine” treatment but still needs lifelong dietary restriction.

Question 16

Arginine administration as a drug

Answer 16

• most disorder of urea cycle requires arginine as an essential amino acid.
• arginine is administered for the production of downstream water-soulble intermediates that leads to nitrogen disposal and decreased plasma ammonia levels.

Question 17

Recurrence of genital herpes can be reduced

Answer 17

Through daily treatment with acyclovir.

Short (7-10 days) course of acyclovir can treat current infection but cant prevent latency.

Question 18

Migrane headache treatment

Answer 18

Acute : NSAID, triptans (postsynaptic serotonin agonist), digydroergotamine.
Prophylaxis:life style changes, ß-blockers, Ca+2 channel blockers, TCA, valproic acid, topiramate,

Question 19

Gamma hemolysis

Answer 19

• enterococci
• s.sopraphyticus
• S.epidermidis.

Question 20

Decomposition of hydrogen peroxide abillity means

Answer 20

Catalase positive

Question 21

Budding yeast

Answer 21

-cryptococcus neoformans(its found on yeast form only, round, oval encapsulated cells with narrow budding)

Question 22

Selenium deficiency can lead to

Answer 22

Dilated cardiomyopathy

Question 23

Restrictive cardiomyopathy can lead to which type of HF

Answer 23

Diastolic HF, (HF with preserved EF).

• causes: idiopathic or infiltrative disorders (amyloidosis, hemochromatosis, sarcoidosis
• transthyritin a protein tetramer produced in liver acts as a carrier of throxine and retinol. Mutation produce amyloid protein that infiltrates the myocardium

Question 24

Trigiminal neuralgia pain

Answer 24

Stabbing pain, lasts for seconds along the branches of trigiminal nerve,pain is triggered by any stimulus to CN V(chewing, tooth cleaning, shaving ,washing)

Question 25

Respiridone side effects

Answer 25

Hyperprolactinemia

Question 26

Methotrexate side effects

Answer 26

- oral and GI mucosa ulcers - alopecia - pancytopenia - hepatotoxicity (fibrosis, hepatitis, cirhosis) - pulmonary fibrosis

Question 27

Half life calculation

Answer 27

t1/2=(0.7 X Vd)/ CL Vd= volume of distrbution CL= clearance rate

Question 28

Selective vasodilators

Answer 28

(E.g hydralazine and minoxidil) - lower BP by reducing systemic vascular resistance. However, this effect is limited by subsequent stimulation of baroreceptors with resulting reflux activation. - this leads to increase HR, CO and contractility. - in addition symphathetic stimulation of RENIN-AG-ALDOSTERONE axis results in sodium and fluid retention with peripheral edema.

Question 29

Polyartritis nodosa

Answer 29

Clinical: Renal= GN, HTA Nervous= peripheral neuropathy and mononeuritis complex GI= mesenteric ischemia/ bowel infarction, bleeding Mucolskeletal= myositis and arthritis. Diagnosis: 1. Young adult, episodic symptoms 2. ANCA negative 3. Assocaited with hepatitis B 4. Tissue biopsy shows transmural inflammation with fibrinoid necrosis. 5. Micro aneurysm in kidney and spasm on arteriorgram.

Question 30

Cardiomegaly with PAS positive is a deficiency in

Answer 30

POMPE disease, deficiency in acid a-glucosidase. -cardiomegaly, hypotonia, macroglossia, and hepatomegaly. Glycogen accumulation in lysosomes

Question 31

Glioblastoma features

Answer 31

Age of onset : 40-70 Originates from astrocytes, usually located in temporal and frontal lobes, and basal ganlgia It commonly crosses the midline, with butterfly distribution. Macroscopic: areas of necrosis and hemorrhage, poorly demarcated from the surrounding tissue. Histology : Pseudopalisading necrosis, new vessel formation and small round cells with bizzare giant cells and large number of mitosis. Its highly maligant

Question 32

High differentiated vs poorly differentiated

Answer 32

Well differentiated low grade tumors Neoplastic cells that are morphologically and archetectrically similar to normal cells in the tissue of origin. In contrast poor differentiated high grade tumors contain neoplastic cell that lack most of the characteristic features of the original tissue. -neoplastic cells that demonstrate a complete lack of differentiation are termed anaplastic

Question 33

Anaplastic tumors (5 features)

Answer 33

1. Loss of cell polarity with complete disruption of normal tissue architecture, cells coalesce into sheets or island in the disorganized infiltrative fashion. 2. Significant variation in the shape and size of cells and nuclei (cellular and nuclear polymorphism) 3. Disproportionally large nuclei (high-nucleus to cytoplasm ratio), that are often hyperchromatic with abundant coarsely clumped chromatin and large nucleoli. 4. numerous often abnormal mitotic figures. 5. Giant, multinucleated tumor cells/