05-18-2011, 05:56 PM
|
NBME 11 block 2 q 1 to 50 - maryam2009
|
05-18-2011, 05:58 PM
to add
13 C A fat embolism is a type of embolism that is often (but not always) caused by physical trauma like fracture of long bones, soft tissue trauma and burns. Fat emboli occur in almost 90% of all patients with severe injuries to bones, although only 10% of these are symptomatic. The risk of fat embolism syndrome is thought to be reduced by early immobilization of fractures and especially by early operative correction. There is also some evidence that steroid prophylaxis of high-risk patients reduces the incidence. The mortality rate of fat-embolism syndrome is approximately 10-20%. The pathogenesis occurs due to both mechanical obstruction and biochemical injury. The microemboli cause pulmonary and cerebral microvasculature occlusion. It is aggravated by local platelet and erythrocyte aggregation. The release of free fatty acids from the fat globules causes local toxic injury to endothelium. The vascular damage is aggravated by platelet activation and recruitment of granulocytes.
05-18-2011, 06:06 PM
15.BB
Coccidioidmycosis....mold in soil.....Southwestern US,California...causes pneumonia and meningitis(very rare). Can disseminate to bone and skin Culture...25degree...Hyphe with doubly reflective wall Biopsy Thick -wall spherules filled with endospores
05-18-2011, 06:14 PM
16.AA
In statistics, analysis of variance (ANOVA) is a collection of statistical models, and their associated procedures, in which the observed variance in a particular variable is partitioned into components attributable to different sources of variation. In its simplest form ANOVA provides a statistical test of whether or not the means of several groups are all equal, and therefore generalizes t-test to more than two groups. ANOVAs are helpful because they possess an advantage over a two-sample t-test. Doing multiple two-sample t-tests would result in an increased chance of committing a type I error. For this reason, ANOVAs are useful in comparing two, three or more means.
05-18-2011, 06:28 PM
17.DD
Post-infectiousPost-infectious glomerulonephritis can occur after essentially any infection, but classically occurs after infection with Streptococcus pyogenes. It typically occurs 10–14 days after a skin or pharyngeal infection with this bacterium. Patients present with signs and symptoms of glomerulonephritis. Diagnosis is made based on these findings in an individual with a history of recent streptococcal infection. Streptococcal titers in the blood (antistreptolysin O titers) may support the diagnosis causes Nephritic syndrome...LM..glumeruli enlarged and hypercelullar Neutrophiles..Lumpy -Bumpy appereance Em...Subepithelial IC humps..IgM,IgG,C3 IF...granular resolve spontanously
05-18-2011, 06:36 PM
18.EE
The thymus, is the principal organ responsible for the T cell's maturation. All T cells originate from haematopoietic stem cells in the bone marrow. Haematopoietic progenitors derived from haematopoietic stem cells populate the thymus and expand by cell division to generate a large population of immature thymocytes. The earliest thymocytes express neither CD4 nor CD8, and are therefore classed as double-negative (CD4-CD8-) cells. As they progress through their development they become double-positive thymocytes (CD4+CD8+), and finally mature to single-positive (CD4+CD8- or CD4-CD8+) thymocytes that are then released from the thymus to peripheral tissues. About 98% of thymocytes die during the development processes in the thymus by failing either positive selection or negative selection, whereas the other 2% survive and leave the thymus to become mature immunocompetent T cells. Positive selection "selects for" T-cells capable of interacting with MHC. Negative selection removes thymocytes that are capable of strongly binding with "self" peptides presented by MHC.
05-18-2011, 06:47 PM
19.DD
Heparin catalyzes the activation of antithrombinIII...dec.Thrombin and Xa short halflife. Immadiate anticoagulation for pulmonary embolism,stroke ,acute coronary syndrome Toxicity...bleeding Thrombocytopenis...HIT,osteoparosis,drug-drug interactions For rapid reversalof heparinization....PROTAMINE SULFATE ****Newer low molecular weight heparin...Enoxaparin act more on Xa have better bioavilibility without laboratory monitoring
05-19-2011, 03:12 AM
20-E "Drug Y alone no effect" ( partial agonist are incapable of eliciting a maximal response and are less efecctive than the full agonist
05-19-2011, 03:30 AM
21-E In treating hepatic encephalopathy, lactulose helps "draw out" ammonia (NH3) from the body.[5]
Lactulose is metabolized in the colon by bacterial flora to short chain fatty acids including the production of the lactic acid and acetic acid. This partially dissociates, acidifying the colonic contents (increasing the H+ concentration in the gut).[6] This favors the formation of the nonabsorbable NH4+ from NH3, trapping NH3 in the colon and effectively reducing plasma NH3 concentrations. The effectiveness of lactulose in treating hepatic encephalopathy is somewhat controversial.[ Lactulose for hepatic encephalopathy generally requires oral dosage three or four times a day with diarrhea almost a certain side effect. "Wikipedia"
05-19-2011, 03:37 AM
22-E A pheochromocytoma or phaeochromocytoma (PCC) is a neuroendocrine tumor of the medulla of the adrenal glands (originating in the chromaffin cells), or extra-adrenal chromaffin tissue that failed to involute after birth [1] and secretes excessive amounts of catecholamines, usually noradrenaline (norepinephrine), and adrenaline (epinephrine) to a lesser extent
TO ADD; The signs and symptoms of a pheochromocytoma are those of sympathetic nervous system hyperactivity, including: Skin sensations Flank pain Elevated heart rate Elevated blood pressure, including paroxysmal (sporadic, episodic) high blood pressure, which sometimes can be more difficult to detect; another clue to the presence of pheochromocytoma is orthostatic hypotension (a fall in systolic blood pressure greater than 20 mmHg or a fall in diastolic blood pressure greater than 10 mmHg on making the patient stand) Palpitations Anxiety often resembling that of a panic attack Diaphoresis (excessive sweating) Headaches Pallor Weight loss Localized amyloid deposits found microscopically Elevated blood glucose level (due primarily to catecholamine stimulation of lipolysis (breakdown of stored fat) leading to high levels of free fatty acids and the subsequent inhibition of glucose uptake by muscle cells. Further, stimulation of beta-adrenergic receptors leads to glycogenolysis and gluconeogenesis and thus elevation of blood glucose levels). A pheochromocytoma can also cause resistant arterial hypertension. A pheochromocytoma can be fatal if it causes malignant hypertension, or severely high blood pressure. This hypertension is not well controlled with standard blood pressure medications Wikipedia |
| « Next Oldest | Next Newest » |