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Biomedical subjects

S Ghosh

Publications and source records attributed to S Ghosh.

At least 703 records · Page 39Linked to original sources
PubMed1993

Time dependent distribution of [203Hg] mercuric nitrate in the subcellular fractions of rat and fish liver.

Cytotoxicity of inorganic mercury to the liver of two species, Anabas testudineus and Sprague Dawley male rat was evaluated. Distribution kinetics of this metal in the different hepatic subcellular fractions were followed for 48 h after a single injection of [203Hg] mercuric nitrate at a dose of 4mg/kg b.w. Interaction of this metal with protein, DNA and RNA was also studied. In rat, nuclear and lysosomal fractions showed a significant increase in the protein content, while in fish, the amount of protein increased in all fractions except microsome. Comparatively more mercury was bound to protein in fish during the later phase of treatment. Retention of mercury in nuclear DNA of rat gradually declined from 15 min to 48 h of treatment, while, mitochondrial DNA binding to mercury increased from 15 min to 2 h of post injection and then declined in the later phase of the experiment. Such a biphasic binding pattern of mercury was shown by both the nuclear and mitochondrial DNA of the fish. The nuclear RNA of rat and mitochondrial and cytosolic RNA of both test species also showed a biphasic pattern of mercury binding, however, with a higher rate of binding in fish at the later phase of the experiment. The present study thus highlights that (a) mercury follows a definite distribution pattern in the subcellular fractions of the liver in both animal species, (b) cytosol is the major site of mercury accumulation.

Animals↗
PubMed1993

Regulation of expression of cell surface neolacto-glycolipids and cloning of embryonic chicken brain GalT-4 (UDP-Gal: GlcNAc-R beta 1-4 galactosyltransferase).

The biosynthesis of GM1 ganglioside (Gal beta 1-3GalNAc beta 1-4 (NeuAc alpha 2-3) Gal beta 1-4Glc-Cer) and nLcOse4Cer is catalyzed by two different beta-galactosyltransferases GalT-3 (UDP-Gal: GM2 beta 1-3GalT) and GalT-4 (UDP-Gal: Lc3 beta 1-4GalT) respectively. Solubilized GalT-3 and GalT-4 have been purified 3,000-fold and 22,000-fold, respectively, from 11-19-day-old embryonic chicken brain. The purified GalT-3 transfers galactose to GM2 very actively (Km 33 microM), whereas acetyl GM2 is not an active substrate (Km 350 microM), GalT-3 and GalT-4 are classified as HYCARS (hydrophobic recognition site) and CARS (carbohydrate recognition sites), respectively. An anion-transport inhibitor DIDS (diisothiocyanato stilbene 4,4'-disulphonate), irreversibly inhibits both GalT-3 and GalT-4 activities by binding to a UDP binding site. Polyclonal antibodies against purified GalT-3 and GalT-4 inhibited these two purified activities and showed no cross reactivity on the western blots. RNA-PCR of 11-day-old embryonic chicken brain mRNA with PCR primers designed from the homologous coding regions of cloned sequences of beta 1-4 GalT of human, bovine, and murine-tissues produced a -600 bp cDNA fragment. Dideoxy-sequences of this fragment reveals it to be 74% similar to the nucleotide sequences of the cloned beta 1-4GalT from human liver. The cloned-600 bp cDNA was used to identify two mRNA transcripts (1.4 and 2.3 kb) from ECB by Northern blot analysis and four genomic DNA EcoRI fragments (18.6, 12.9, 10.5 and 3.7 kb) on a Southern blot analysis.

Animals↗
PubMed1993

Purification of two azoreductases from Escherichia coli K12.

Two azoreductases (I and II) were purified to homogeneity from extracts of E. coli K12. Azoreductase I was a dimer of two identical subunits of molecular weight 28000 whereas azoreductase II was a monomer of 12,000 molecular weight. Both NADH and NADPH functioned as electron donors for the azoreductases. Azoreductase I and II used Ponceau SX, Tartrazine, Amaranth and Orange II as substrates. Ponceau SX was the best substrate for both the enzymes. However, azoreductase II utilized tartrazine, amaranth and orange II less efficiently than azoreductase I.

Azo Compounds↗
PubMed1993

Adult respiratory distress syndrome associated with antiphospholipid antibody syndrome.

Antiphospholipid antibody syndrome (APS) has been shown to be associated with arterial and venous thromboses, recurrent miscarriages, and thrombocytopenia. We describe 3 cases of adult respiratory distress syndrome (ARDS) in patients with primary APS. The autopsy in one patient revealed no evidence of vasculitis, but extensive small vessel thrombosis of multiple organs including the lungs was seen. No infectious process, connective tissue diseases, or pulmonary edema could be documented and there was no clinical or laboratory evidence of vasculitis in the other 2 patients. The 2 patients who survived responded dramatically to intravenous steroids.

Adult↗
PubMed1993

Statistical evaluation of multiple-locus linkage data in experimental species and its relevance to human studies: application to nonobese diabetic (NOD) mouse and human insulin-dependent diabetes mellitus (IDDM).

Common, familial human disorders generally do not follow Mendelian inheritance patterns, presumably because multiple loci are involved in disease susceptibility. One approach to mapping genes for such traits in humans is to first study an analogous form in an animal model, such as mouse, by using inbred strains and backcross experiments. Here we describe methodology for analyzing multiple-locus linkage data from such experimental backcrosses, particularly in light of multilocus genetic models, including the effects of epistasis. We illustrate these methods by using data from backcrosses involving nonobese diabetic mouse, which serves as an animal model for human insulin-dependent diabetes mellitus. We show that it is likely that a minimum of nine loci contribute to susceptibility, with strong epistasis effects among these loci. Three of the loci actually confer a protective effect in the homozygote, compared with the heterozygote. Further, we discuss the relevance of these studies for analogous studies of the human form of the trait. Specifically, we show that the magnitude of the gene effect in the experimental backcross is likely to correlate only weakly, at best, with the expected magnitude of effect for a human form, because in humans the gene effect will depend more heavily on disease allele frequencies than on the observed penetrance ratios; such allele frequencies are unpredictable. Hence, the major benefit from animal studies may be a better understanding of the disease process itself, rather than identification of cells through comparison mapping in humans by using regions of homology.

Animals↗
PubMed1993

Can guava fruit intake decrease blood pressure and blood lipids?

A randomized, single-blind, controlled trial was conducted to examine the effects of guava fruit intake on BPs and blood lipids in patients with essential hypertension. Of 145 hypertensives that entered the trial, 72 patients were assigned to take a soluble fibre and a potassium-rich diet containing 0.5-1.0 kg of guava daily (group A) and 73 patients to their usual diet (group B), while salt, fat, cholesterol, caffeine and alcohol intake were similar in both groups. Mean age, mean body weight and male sex, were similar, and so were risk factors, mean BPs, mean serum sodium, potassium, calcium, magnesium, triglycerides, cholesterol and HDL-cholesterol in both groups. Dietary adherence to guava intake was checked by a questionnaire. After four weeks of follow-up on an increased consumption of dietary potassium and low sodium/potassium ratio, group A patients were associated with 7.5/8.5 mmHg net decrease in mean systolic and diastolic pressures compared with group B. Increased intake of soluble dietary fibre (47.8 +/- 11.5 vs. 9.5 +/- 0.85 g/day) was associated with a significant decrease in serum total cholesterol (7.9%), triglycerides (7.0%) and an insignificant increase in HDL-cholesterol (4.6%) with a mild increase in the ratio of total cholesterol/HDL-cholesterol in group A patients compared with group B. It is possible that an increased consumption of guava fruit can cause a substantial reduction in BPs and blood lipids with a lack of decrease in HDL-cholesterol due to its higher potassium and soluble fibre content, respectively.

Adult↗
PubMed1992

Isolation of a cDNA clone for beta 1-4 galactosyltransferase from embryonic chicken brain and comparison to its mammalian homologs.

Based on the observed biochemical and immunological similarities between bovine beta 1-4 galactosyltransferase (GalT) and a developmentally regulated galactosyltransferase (GalT-4; UDP-Gal:Lc3 beta 1-4 GalT) from embryonic chicken brain, a genetic similarity between the two enzymes has been postulated. To test our hypothesis, we have employed a reverse transcription-polymerase chain reaction (RT-PCR)based approach and isolated a approximately 600 bp cDNA clone from embryonic chicken brain mRNA. Our results indicate that, within the approximately 600 bp fragment, the avian cDNA nucleotide sequence is 74% homologous to the human beta 1-4 galactosyltransferase cDNA. Similarity and identity between the predicted amino acid sequences of the two galactosyltransferases are 75% and 61%, respectively. Similar to its mammalian counterparts, the embryonic chicken brain galactosyltransferase gene appears to encode multiple mRNA transcripts (2.3 and 1.4 kb) and shows multiple bands on a Southern blot (18.6, 12.9, 10.5 and 3.7 kb) indicating that the avian gene is either polyexonic and/or it belongs to a multiple gene family.

Amino Acid Sequence↗
PubMed1992

Effects of guava intake on serum total and high-density lipoprotein cholesterol levels and on systemic blood pressure.

There is evidence that inclusion of high fiber foods such as oats, fruits and vegetables in the diet can decrease fat intake and modulate blood lipids. To test this hypothesis, 61 group A and 59 group B patients with essential hypertension were administered guava fruit preferably before meals in a foods-to-eat approach rather than foods-to-restrict, in a randomized and single-blind fashion for 12 weeks. At entry into the study, mean age, male sex, mean body mass index, percentages of risk factors and mean levels of blood lipids were comparable between groups A and B. Adherence to guava consumption was assessed by questionnaires and weighing of guava intake by 24-hour recall after 12 weeks of follow-up. Nutrient intakes including saturated and total fat were significantly decreased; carbohydrates, total and soluble fiber and vitamins and mineral intakes were significantly higher in group A than in group B at 12 weeks. There was a significant net decrease in serum total cholesterol (9.9%), triglycerides (7.7%) and blood pressures (9.0/8.0 mm Hg) with a significant net increase in high-density lipoprotein cholesterol (8.0%) after 12 weeks of guava fruit substitution in group A than in group B. By adding moderate amounts of guava fruit in the usual diet, changes in dietary fatty acids and carbohydrates may occur, providing significant amounts of soluble dietary fiber and antioxidant vitamins and minerals without any adverse effects. There is a greater decrease in lipoprotein metabolism and blood pressures.

Blood Pressure↗
PubMed1992

Effect of fat-modified and fruit- and vegetable-enriched diets on blood lipids in the Indian Diet Heart Study.

This study was designed to test the efficacy of the administration of fruits and vegetables for 12 weeks as an adjunct to a prudent diet in decreasing blood lipids in 310 (intervention; group A) and 311 (control; group B) patients with risk factors of coronary artery disease (CAD) in a parallel, single-blind fashion. At entry to the study, sex, mean age, body weight, body mass index, systolic and diastolic blood pressures, and blood lipoproteins were comparable between both groups. Tasty fruits and vegetables were given to patients to eat before major meals for better nutrient adherence and adequacy. Dietary intakes were determined by questionnaires and by weighing of fruit and vegetable intake. Fruits and vegetables decreased total cholesterol level by 6.5% and low-density lipoprotein cholesterol level by 7.3% in group A, whereas the levels were unchanged in group B. The high-density lipoprotein cholesterol levels that decreased during the diet stabilization period in both groups, increased by 5.6% in group A after 12 weeks. Serum triglycerides also decreased (7%) more in group A than B. Fasting blood glucose decreased by 6.9% in group A and by 2.6% in group B. The combined effect of a fat-modified diet plus fruits and vegetables was greater than these changes. Because tasty fruits were taken by the patients before meals (when they are hungry) and are easily available at reasonable cost in our marketing and buying capacity, the compliance was excellent.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose↗