Biomedical subjects
Publications and source records attributed to M K Ghosh.
Pattern of classification in an renal neoplasm is variable. If calcium is located nonperipherally (within the mass) it is more likely to be a renal cell carcinoma. But peripheral calcification does not rule out malignancy.
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The survival pattern, morbidity, and clinical course of 145 patients with endomyocardial fibrosis who were followed up between November 1975 and June 1987 were studied. The diagnosis was confirmed in all cases by cardiac angiography, or echocardiography, or necropsy. Percentage survival at the end of one and 9.5 years was 76.11 and 26.35 respectively. History, physical examination, electrocardiography, and cardiac catheterisation were studied at the first presentation. The determinants of early mortality were studied by univariate Kaplan-Meier estimates compared by the log rank test and Cox proportional hazards multiple regression analysis. Significant univariate predictors of early mortality were QRS axis above +90 degrees, intraventricular conduction delay (QRS duration greater than 0.12 s), duration of symptoms before presentation, New York Heart Association functional classes III and IV, presence of embolic episodes, right atrial mean pressures greater than 20 mm Hg, right ventricular end diastolic pressure greater than 20 mm Hg, and aortic oxygen saturation less than 85%. The significant multivariate predictors of mortality were cyanosis, New York Heart Association functional class at first presentation, and right atrial mean pressure greater than 20 mm Hg. The bleak prognosis of endomyocardial fibrosis did not substantially improve despite advances in the medical management of congestive cardiac failure during the period of the study.
In the targeting of chemotherapeutic agents to specific cells via covalent conjugation of the agent to monoclonal antibodies, conjugation methods which lead to maximum binding capacity with minimum loss of activity (for both drug and antibody) are essential. A model system for evaluation of various conjugation procedures is described. Rabbit anti-bovine serum albumin immunoglobulin (IgG) was used to represent the antibody, and methotrexate (MTX) was used as the targeting agent. The procedures evaluated were coupling via water soluble 1-ethyl-3 (3'-dimethylaminopropyl) carbodiimide (EDCI), or via prior activation of MTX's carboxyl groups involving active ester (N-hydroxysuccinimide) or mixed anhydride (isobutylchloroformate) formation. The formation of covalent conjugates in all three cases was verified by (a) the lack of incorporation of MTX into IgG when the reactions were performed in the absence of EDCI, or when MTX was reacted without prior activation, and (b) the presence of a constant amount of MTX in the conjugates after exhaustive dialysis of gel-filtration through Sephadex G-50. High incorporation of MTX and high retention of antifolate activity resulted from the EDCI coupling reaction, but there was very low recovery of protein (conjugate) and antibody activity. The biological and physicochemical properties of the conjugates prepared by the two pre-activation methods did not show any significant difference, but the conjugates prepared by the active ester method had a longer shelf-life. Therefore, of the three reactions investigated, the active ester method is our method of choice for conjugating MTX to IgG.
A preparative method for the isolation of peroxisomes from the liver of normal, untreated rats is described. The peroxisome-enriched "light mitochondrial" fraction is layered on a 30% Nycodenz (5-[N-2,3-dihydroxypropylacetamido]-2,4,6-triiodo-N,N'-bis[2, 3-dihydroxypropyl]isophthalamide) solution containing 1 mM tetrasodium EDTA and then centrifuged in an angular rotor for 1 h at 130,000gavg. Peroxisomes are sedimented to the bottom leaving other organelles at the top of the tube. On the basis of morphological and biochemical studies, it is found that the peroxisomes (marker-enzymes catalase and urate oxidase) obtained in this method are not contaminated with lysosomes (marker-enzyme acid phosphatase) and contained very few mitochondria (marker-enzyme succinate-cytochrome c reductase) and microsomal vesicles (marker-enzyme glucose-6-phosphatase).
On subcellular fractionation, the enzyme acyl/alkyl dihydroxyacetone phosphate (DHAP) reductase (EC 1.1.1.101) in guinea pig and rat liver was found to be present in both the light mitochondrial (L) and microsomal fractions. By using metrizamide density gradient centrifugation, it was shown that the alkyl DHAP reductase activity in the "L" fraction is localized mainly in peroxisomes. From the distribution of the marker enzymes it was calculated that about two-thirds of the liver reductase activity is in the peroxisomes and the rest in the microsomes. The properties of this enzyme in peroxisomes and microsomes are similar with respect to heat inactivation, pH optima, sensitivity to trypsin, and inhibition by NADP+ and acyl CoA. The enzyme activity in the peroxisomes and microsomes from mouse liver is increased to the same extent by chronically feeding the animals clofibrate, a hypolipidemic drug. The kinetic properties of this enzyme in these two different organelles are also similar. From these results it is concluded that the same enzyme is present in two different subcellular compartments of liver.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
While investigating a chest opacity in Behcet's disease possibility of pulmonary aneurysm should be considered. Contrast enhanced CT is a safe diagnostic method which is useful in confirming or excluding the presence of an aneurysm in such cases. We report here the first case of bilateral pulmonary aneurysms in Behcet's disease.
It is now widely accepted that germinal cell tumors can arise primarily in the mediastinum. Primary extragenital seminoma has been documented arising in the mediastinum but very few reports are available about primary mediastinal embryonal cell carcinoma. We report a case of this rare condition with radiological and CT features.
A case of pseudoaneurysm with erosion of both pulmonary and bronchial vessels is reported. The diagnosis was confirmed by computed tomography followed by intravenous digital subtraction angiography. It was removed surgically.