05-11-2011, 03:10 PM
sash11 you're welcome TY for your ans and explinations too
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NBME 7 block 2 q 1 to 50 - maryam2009
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05-11-2011, 03:31 PM
13. B
Gout: Asymetric joint distribution. Joint is swollen, red, and painful. classic manifestation is painfull MTP joint of the big toe ( Podagra). Tophus formation often on external ear, oleocranon bursa, or achiles tendon. Acute attack tends to occur after a large meal or alcohol consumption ( alcohol metabolism compete for same excretion sites in the kidney as uric acid, causing decrease uric acid secretion and subsequent buildup in blood. Findidng: Precipitation of monosodic ureate crystals into joints due to hyperuricemia, which can be caused by Lesch Nyhan Syndrome, PRPP excess.... Crystals are needle shaped birefringent= yellow under parallel light TTO: Colchicine, NSAIDs, probenecid, allopurinol. FA page 380
05-11-2011, 03:32 PM
******************Corretion ****************
14. B Gout: Asymetric joint distribution. Joint is swollen, red, and painful. classic manifestation is painfull MTP joint of the big toe ( Podagra). Tophus formation often on external ear, oleocranon bursa, or achiles tendon. Acute attack tends to occur after a large meal or alcohol consumption ( alcohol metabolism compete for same excretion sites in the kidney as uric acid, causing decrease uric acid secretion and subsequent buildup in blood. Findidng: Precipitation of monosodic ureate crystals into joints due to hyperuricemia, which can be caused by Lesch Nyhan Syndrome, PRPP excess.... Crystals are needle shaped birefringent= yellow under parallel light TTO: Colchicine, NSAIDs, probenecid, allopurinol. FA page 380
05-11-2011, 04:20 PM
15.AA
1-Hemoglobin is an assembly of four globular protein subunits(polypeptide chains).... 2- Each subunit is composed of a protein chain tightly associated with a non-protein heme group. 3-Each protein chain arranges into a set of alpha-helix structural segments connected together in a globin fold arrangement, 4.Adult hemoglobin is made of 2 alpha and 2 beta chains 5-These four polypeptide chains are bound to each other and stabilized by a- salt bridges...which is a noncovalent bonding...due to interaction between anionic carboxylate (RCOO-) and cationic ammonium (RNH3+) in the amino acids b-hydrogen bonds, c- hydrophobic interactions....oil and water donot combine becuase of hydrophobic interaction ...and hydrophobic interaction is a property of nonpolar molecules and this interaction is also used in the case of protein folding where by most folded proteins have a hydrophobic core in which side chain packing stabilizes the folded state, and charged or polar side chains on the solvent-exposed surface where they interact with surrounding water molecules. 6-the hydrophobic effect is important to understand the structure of proteins that have hydrophobic amino acids, such as alanine, valine, leucine, isoleucine, phenylalanine, and methionine grouped together with the protein...and hydrophobic interaction is between individual aminoacids 7-Ordinarily, the hemoglobin molecules exist as single, isolated units in the red cell, whether they have oxygen bound or not... 8-Sickle hemoglobin exists as isolated units in the red cells when they have oxygen bound. 9-When sickle hemoglobin releases oxygen in the peripheral tissues, however, the molecules tend to stick together and form long chains or polymers Let us see what happens in sickle cell anemia...glutamic acid(hydrophillic ) is replaced by hydrophobic valine (which increases the number of hydrophobic aminoacids ...which inturn increases hydrophobic interactions ) ..and these hydrophobic interactions stabilize the polymerized sickle hemoglobin.... Sorry for the long explanation ....I found this very interesting when I read about it posted by yeabiruh
05-11-2011, 05:18 PM
16.D
Significant functional aspects of the occipital lobe is that it contains the primary visual cortex and is the part of the brain where dreams come from. A. Caudate nucleus B. Primary motor cortex area C. Thalamus E. Posterior Limb
05-11-2011, 05:21 PM
16.D
Homonymous hemianopsia can be congenital, but is usually caused by brain injury such as from stroke, trauma, tumors, infection, or following surgery. Vascular and neoplastic (malignant or benign tumours) lesions from the optic tract, to visual cortex can cause a contralateral homonymous hemianopsia. Injury to the right side of the brain will affect the left visual fields of each eye. The more posterior the cerebral lesion, the more symmetric (congruous) the homonymous hemianopsia will be. For example, a person who has a lesion of the right optic tract will no longer see objects on his left side. Similarly, a person who has a stroke to the right occipital lobe will have the same visual field defect, usually more congruent between the two eyes, and there may be macular sparing. A stroke on the right side of the brain (especially parietal lobe), in addition to producing a homonymous hemianopsia, may also lead to the syndrome of hemispatial neglect.
05-11-2011, 05:26 PM
17.E
Schizoid personality disorder (SPD) is a personality disorder characterized by a lack of interest in social relationships, sometimes sexually apathetic, a tendency towards a solitary lifestyle, secretiveness, and emotional coldness. SPD is not the same as schizophrenia, although they share some similar characteristics such as detachment or blunted affect and there is increased prevalence of the disorder in families with schizophrenia.
05-11-2011, 05:33 PM
18. C
Gardner syndrome, also known as familial colorectal polyposis, is an autosomal dominant form of polyposis characterized by the presence of multiple polyps in the colon together with tumors outside the colon.The extracolonic tumors may include osteomas of the skull, thyroid cancer, epidermoid cysts, fibromas and sebaceous cysts, as well as the occurrence of desmoid tumors in approximately 15% of affected individuals. The countless polyps in the colon predispose to the development of colon cancer; if the colon is not removed, the chance of colon cancer is considered to be very significant. Polyps may also grow in the stomach, duodenum, spleen, kidneys, liver, mesentery and small bowel. In a small number of cases, polyps have also appeared in the cerebellum. Cancers related to GS commonly appear in the thyroid, liver and kidneys. At this time, there is no cure, and in its more advanced forms, it is considered a terminal diagnosis with a life expectancy of 35–45 years; treatments are surgery and palliative care, although some chemotherapy has been tried with limited success. Gardner syndrome is now known to be caused by mutation in the APC gene located in chromosome 5q21 (band q21 on chromosome 5). This is the same gene as is mutant in familial adenomatous polyposis (FAP), a more common disease that also predisposes to colon cancer. |
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