Questions and guide to answers

Gene encoding products involved in controlling the expression of one or more other genes [1] The entire nucleic acid sequence that is necessary for the synthesis of a functional polypeptide [2] These products may be RNA (as in the case of genes encoding mRNAs) or protein that binds to the regulatory sites regulating transcription of genes [1] It is a segment of DNA containing transcribed parts (exon and introns) separated by untranscribed parts (regulatory sites)


Questions from exam
(1) Difference between regulatory and coding gene. Guide to answers (1) Difference between regulatory and coding gene A gene is any type of sequence of genomic DNA or RNA that is indispensable for a specific biological function, irrespective of whether that function requires the transcription or translation of the gene. Genes are subdivided into regulatory genes, RNAgenes, and protein-coding genes.

Regulatory Coding
Gene encoding products involved in controlling the expression of one or more other genes [1] The entire nucleic acid sequence that is necessary for the synthesis of a functional polypeptide [2] These products may be RNA (as in the case of genes encoding mRNAs) or protein that binds to the regulatory sites regulating transcription of genes [1] It is a segment of DNA containing transcribed parts (exon and introns) separated by untranscribed parts (regulatory sites) Can act as an activator, turning a gene or a group of genes on so that expression can occur [1] Are involved in the process of cell differentiation, determining what a cell will develop into. This allows organisms to have great diversity in cell types, making everything from neurons to skin cells [1] Can act as repressors, turning genes off so that they cannot express by preventing RNA transcription. This type of regulatory gene may also act to suppress a harmful gene 'oncogene per example, keeping an organism healthy [1] Exons-Synthesis of functional proteins Regulatory sites Promotor Enhancer (50 kb or more from the coding region) Sequences that specify 3 0 cleavage and polyadenylation Sequences that specify splicing of primary RNA transcripts [2] (2) Clinical suspicion and management of Budd-Chiari syndrome (a) Definition [3] (i) Any pathophysiologic process that results in interruption or diminution of the normal blood flow out of the liver. Budd-Chiari syndrome implies thrombosis of the hepatic veins and/or the intrahepatic or suprahepatic inferior vena cava. (b) Predisposing factors [3] (i) Locally invasive tumors: Hepatocellular carcinoma, renal, and adrenal adenocarcinoma. Also, parasitic and nonparasitic cysts and abscesses. (ii) Surgery or trauma: Compression or kinking of the hepatic veins can occur following hepatic resection or transplantation. Budd-Chiari syndrome may occur following blunt abdominal trauma. (iii) Hypercoagulable states: Myeloproliferative diseases, malignancy, oral contraceptives, pregnancy, factor V Leiden mutation, prothrombin gene mutation, antiphospholipid antibody syndrome, antithrombin III deficiency, protein C deficiency, protein S deficiency, paroxysmal nocturnal hemoglobinuria, JAK2 mutations, Behcet's disease, membranous webs of the inferior vena cava and/or the hepatic veins. (iv) Idiopathic. (c) Patients with acute disease usually present with severe right upper quadrant pain and hepatomegaly. Jaundice and ascites may not be apparent initially, but often develop rapidly. Variceal bleeding may also occur. Fulminant hepatic failure may occur. The subacute and chronic forms of Budd-Chiari syndrome have been present for several weeks to more than 6 months before clinical presentation. The clinical manifestations and duration of disease before presentation depend on the particular vessels that are occluded, the extent of occlusion, and the recruitment of collateral circulation. Chronic or subacute Budd-Chiari syndrome should be considered in the differential diagnosis of otherwise unexplained liver dysfunction, particularly in patients in whom ascites is a principal feature, or in those who have a known risk factor for Budd-Chiari syndrome [4]. (d) Laboratory (i) Serum aminotransferases and alkaline phosphatase can be normal or increased. (ii) Levels of serum albumin, serum bilirubin, and prothrombin can be normal or abnormal. (e) Imaging features [5] (i) Radiograph venography has been the gold standard for the evaluation of the hepatic veins. It is performed by accessing the hepatic venous circulation percutaneously. (ii) Doppler imaging is the most useful noninvasive diagnostic test to screen for the presence of Budd-Chiari syndrome. (iii) Computed tomography (CT) with failure to visualize the hepatic veins is considered suggestive of hepatic vein obstruction. Caudate lobe hypertrophy is found in about 75% of patients (separate venous drainage of this liver lobe into the inferior vena cava). (iv) MRI, contrast-enhanced magnetic resonance venography. (f) Treatment [5] (i) Medical treatment (including supportive care, anticoagulation, thrombolysis, and medical treatment for portal hypertension). (ii) Radiologic procedures (such as angioplasty, TIPS, and stenting).

(iii) Surgical intervention (including shunting procedures and liver transplantation). (3) Reversible dementia in the elderly (a) Definition [6]
Dementia is a disorder that is characterized by impairment of memory and at least one other cognitive domain (aphasia, apraxia, agnosia, executive function). These must represent a decline from a previous level of function and be severe enough to interfere with daily function and independence. (b) Reversible causes [6] Some types of dementia are reversible. This means that they can be treated and possibly cured. A treatable dementia occurs because of some other condition. The most common cause of reversible dementia is a toxic reaction to medication. The reported frequency of dementia because of potentially reversible causes varies from 0 to 23%. The most common among these causes are (i) Alcohol-related and medication-related dementia. (ii) Depression-induced cognitive impairment. (iii) Surgical brain lesions such as normal pressure hydrocephalus, tumors, and chronic subdural hematomas. bowel, bowel wall thickening, and/or pneumatosis intestinalis. (iv) Doppler (limited) (only in proximal occlusion celiac or superior mesenteric arteries). (v) Experimental tests [9].
Glutathione S-transferase a.
Intestinal fatty acid-binding protein.