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Biomedical subjects

A K Rustgi

Publications and source records attributed to A K Rustgi.

85 records · Page 5Linked to original sources
PubMed1990

Two genes encode factors with NF-kappa B- and H2TF1-like DNA-binding properties.

NF-kappa B and H2TF1 are transcription factors that bind to related DNA sequence motifs. NF-kappa B is a constitutive factor in mature B lymphocytes and is inducible in immature B cells and nonlymphoid cells. H2TF1 is a constitutive ubiquitous transcription factor that activates expression of major histocompatibility complex class I genes. We report here the isolation of two zinc finger genes. One, named MBP-2 (major histocompatibility complex-binding protein 2), encodes a factor that has DNA-binding properties similar, if not identical, to the H2TF1 transcription factor. The second, named KBP-1 (kappa-enhancer binding protein 1), encodes a factor that is similar to, but distinct from, NF-kappa B in its DNA-binding properties and methylation interference pattern, suggesting that at least two proteins can bind to the immunoglobulin kappa gene enhancer.

Base Sequence↗
PubMed1989

Suppression of MHC class I gene expression by N-myc through enhancer inactivation.

Amplification of the N-myc oncogene in human neuroblastoma is associated with increased metastatic ability. We previously found that over-expression of N-myc in rat neuroblastoma tumor cells causes a dramatic reduction in the expression of MHC class I mRNA. We show here that two distinct elements in the promoter render the MHC class I genes susceptible to N-myc-mediated suppression, one of which was identified as the MHC class I gene enhancer. Our data indicate that elevated N-myc expression is associated with reduced binding of a transcription factor that activates this enhancer. As a result, the activity of the MHC class I gene enhancer is greatly diminished. Elevated expression of the N-myc oncogene in human neuroblastomas and murine pre-B lymphoid lines also correlated with reduced factor binding to the MHC class I gene enhancer. Thus, an important effect of N-myc may be to impair the function of certain cellular enhancers by altering the levels of their cognate binding proteins.

Animals↗
PubMed1989

Pyogenic and amebic liver abscess.

Amebic liver abscess is more common than pyogenic liver abscess on a global scale. In the United States, pyogenic liver abscess is more frequently seen. The epidemiology, etiology, microbiology, clinical features, natural history, diagnostic studies, and treatment of pyogenic and amebic liver abscess are discussed.

Adult↗
PubMed1989

Hepatic imaging and advanced endoscopic techniques.

Diseases of the liver and biliary tract can be diagnosed and potentially treated by a variety of radiologic modalities and endoscopic techniques. The imaging modalities of ultrasonography, computed tomography, nuclear scintigraphy and magnetic resonance are emphasized in this article. The current status of endoscopic retrograde cholangiopancreatography, sphincterotomy, biliary endoprostheses, cholangioscopy, endoscopic ultrasound, and laser lithotripsy is discussed.

Biliary Tract Diseases↗
PubMed1989

The clinical utility of the Ca19-9 radioimmunoassay for the diagnosis of pancreatic cancer presenting as pain or weight loss. A cost-effectiveness analysis.

CA 19-9 is a promising radioimmunoassay for the detection of pancreatic cancer, but its clinical role and cost-effectiveness are not yet known. To investigate these factors, we used clinical decision analysis to study diagnostic strategies for patients with suspected pancreatic cancer presenting as pain or weight loss. Comprehensive diagnostic strategies were developed to reflect current and future patterns of practice utilizing CA19-9 radioimmunoassay (RIA) to yield biopsy-proved cancer or confidently exclude its presence. The performance of the strategies beginning with CA19-9 RIA and ultrasonography were equivalent in positive and negative predictive values over a range of prevalence of pancreatic cancer from 0.02 to 0.15. At higher prevalence, the negative predictive value of the ultrasonography strategy became significantly better. The CA19-9 RIA strategy used fewer noninvasive tests, endoscopic retrograde cholangiopancreatographic procedures, and invasive radiologic studies than did the ultrasonography strategy at each prevalence. The health care costs ranged between $848 and $1413 per patient for the CA19-9 RIA strategy and $1186 and $1848 per patient for the ultrasonography strategy. We conclude that the CA19-9 RIA is a useful, cost-effective initial test for the examination of patients with suspected pancreatic cancer.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1988

Pulmonary perfusion after rt-PA therapy for acute embolism: early improvement assessed with segmental perfusion scanning.

To determine if pulmonary perfusion was improved in acute pulmonary embolism after therapy with recombinant human tissue-type plasminogen activator (rt-PA), lung scans were obtained before and a mean of 22 hours after therapy in 19 patients. The posttherapy lung scans were compared with baseline, pretherapy scans with use of two semiquantitative methods--an anteroposterior view method, similar to that used in the Urokinase Pulmonary Embolism Trial, and a segmental method that emphasized pulmonary anatomy. There was an improvement in the defect score from 0.35 to 0.14 (P less than .01) when the anteroposterior view method was used and from 0.37 to 0.16 (P less than .01) when the segmental method was used. These encouraging results in the early posttherapy period suggest that rt-PA is especially effective in improving regional perfusion after pulmonary embolism and that a larger controlled trial of therapy with rt-PA for acute pulmonary embolism should be performed. Scoring lung scans with a segmental method is feasible and appropriate for present-day lung scan technique and should be considered in future studies.

Adult↗
PubMed1988

Gluten-sensitive enteropathy and systemic lupus erythematosus.

A patient with systemic lupus erythematosus developed gluten-sensitive enteropathy, or celiac sprue. The patient's histocompatibility antigens included HLA-B8 and HLA-DR3, previously found to have a high frequency in gluten-sensitive enteropathy and possibility increased as well in systemic lupus erythematosus. Such histocompatibility antigens are common to a variety of autoimmune disorders. An immune basis for the association is discussed herein.

Celiac Disease↗
PubMed1987

Cardiac myonecrosis in hypertensive crisis associated with monoamine oxidase inhibitor therapy.

A young woman taking tranylcypromine for depression was hospitalized with severe chest pain and hypertension after eating cheese. Electrocardiography initially showed arrhythmias and precordial ST segment depression. Myocardial creatine kinase values were elevated, and echocardiography showed regional ventricular dysfunction, suggestive of focal cardiac myonecrosis. The cardiovascular pathophysiology of tyramine hypertensive crisis and related catecholamine excess states, including pheochromocytoma and clonidine withdrawal, is reviewed. Cardiac myonecrosis is a potential adverse effect of the hypertensive crisis associated with monoamine oxidase inhibitor use. Psychiatric indications for monoamine oxidase inhibitors may be expanding, but clinicians should continue to exercise caution in the use of these agents.

Adult↗
PubMed1987

The effect of timolol on anterior-chamber oxygenation.

The effect of timolol maleate, a nonspecific beta-blocking agent, on anterior-segment oxygenation was studied using oxygen-sensitive microelectrodes inserted into the mid-anterior chamber of 13 cat eyes. The anterior-chamber oxygen tension was monitored continuously for two hours following the topical application of three drops of timolol 0.5%. Although a small, but significant, decline in oxygen tension of 19% was observed over the initial 90 minutes (P less than or equal to .05), the overall 10% decrease at the end of two hours was not considered either clinically or statistically significant when compared with a group of controls. Timolol, since it does not contribute significantly to hypoxia, may therefore be a more prudent choice for lowering intraocular pressure in disorders where hypoxia is believed to play an important role, such as in neovascular glaucoma and sickle-cell hyphema.

Animals↗
PubMed1985

Successful management of late-onset primary lymphatic hypoplasia.

Primary lymphedema of the extremities, abdomen, or chest is an unusual and difficult clinical problem with few guidelines for management. A case is reported of lymphedema acquired at the age of 61 years, with associated massive chylous ascites and chylothorax. No underlying condition was discovered and the patient was found to have hypoplastic lymphatics by lymphangiography. Initial management consisted of extremity elevation, diuresis, and repeated paracenteses and thoracenteses. A peritoneojugular shunt provided temporary relief. Surgical pleurodesis combined with intensive diuresis has given prolonged relief of his symptoms allowing him to return to a functional life. Diagnostic and therapeutic guidelines for the management of this unusual condition are suggested.

Chylothorax↗
PubMed1984

Energy absorption in cylinders containing an off-axis linear source.

An analytical model for evaluating the absorption of gamma rays by cylindrical tissues has been developed. This model introduces the case of an off-axis linear source of radiation inside the cylinder. The total energy absorbed by the tissue for different source strengths, absorption properties of the tissues, and the aspect ratio of the length of the cylinder to its radius have been evaluated.

Gamma Rays↗