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Biomedical subjects

S Banerjee

Publications and source records attributed to S Banerjee.

At least 469 records · Page 26Linked to original sources
PubMed1991

Regional cellular heterogeneity and DNA synthetic activity in rat ventral prostate during postnatal development.

Previous studies have provided evidence that the rat ventral prostate grows primarily, if not exclusively, at its distal tips. However, as yet there have been no analyses in which individual cells in defined regions of the prostatic ductal system have been resolved and quantified. Moreover, the possibility that the prostate might grow differently at different times of postnatal development has received little attention. Our objectives were to identify and quantify the proliferating epithelial and stromal cells in defined regions of the rat ventral prostate during its postnatal development. To this end, 3H-thymidine was administered in vivo to rats of ages 10-60 days. A dissection technique was then used by which the distal, intermediate, and proximal segments of the prostatic ductal system were physically isolated from each other without removing the stromal tissue. Longitudinal sections of these segments were examined for cellular composition and DNA synthetic activity. Regional heterogeneity with respect to cell composition and cell proliferation was seen. In rats of all ages, DNA synthetic activity was seen in epithelial and stromal cells throughout the prostate, rather than only in the distal segment. At Days 10 and 20, significantly higher percentages of epithelial and stromal cells were labeled in the distal than in the proximal segments; but at Days 45 and 60, the percentages of labeled epithelial and stromal cells in the distal, intermediate, and proximal segments were similar. Thus, in all segments, and at all ages, substantial labeling was seen throughout the prostate. These data suggest that the prostate grows in both length and width throughout postnatal development, reminiscent of the growth of a tree.

Animals↗
PubMed1991

Poisoning with oxybutynin.

A case of poisoning with 100 mg of oxybutynin in a 34-year-old female is reported. The main features were anticholinergic effects, including stupor, followed by disorientation and agitation on awakening, dilated pupils, dry skin and retention of urine. She had a sinus tachycardia which resolved 3 h after admission, and in addition ventricular ectopics and bigeminy which continued for a further 30 h. She recovered fully on symptomatic treatment alone.

Adult↗
PubMed1991

Prevalence and incidence of human immunodeficiency virus among patients undergoing long-term hemodialysis. The Cooperative Dialysis Study Group.

PURPOSE: The purpose of this voluntary multicenter study was to estimate the prevalence and incidence of human immunodeficiency virus (HIV) infection and the risk of nosocomial transmission of HIV in hemodialysis patients in the United States. PATIENTS AND METHODS: In June 1986, we began collecting epidemiologic data, risk factor information, and serum for HIV antibody testing from long-term hemodialysis patients on entry into the study and 1 year later. RESULTS: Initial data and specimens were collected from 1,324 patients in 28 dialysis centers in 12 states. On entry, 26 were positive or equivocal by enzyme immunoassay; 13 of these were positive by Western blot assay (overall seroprevalence 0.98%). Seroprevalence was higher for patients tested in eight centers located in areas from which a high cumulative incidence of acquired immunodeficiency syndrome has been reported (500 or more cases per 1 million persons) than for patients in other areas (10 of 387 [2.6%] versus three of 937 [0.3%]; p = 0.00048). According to their dialysis records, all 13 of the Western blot-positive patients had received transfusions. Seropositive patients were not more likely to have received a transfusion than seronegative patients (13 of 13 versus 1,038 of 1,311; p = 0.08). The confidential risk factor questionnaire was completed by 1,206 (91%) patients including nine of 13 (69%) of the seropositive patients. A question on sharing needles for injection of drugs was answered by 1,158 patients; seropositive patients were more likely to report they had shared needles than seronegative patients (five of nine versus 17 of 1,149; p = 0.0000002). After 1 year of follow-up, data were collected from 667 patients, including 254 negative patients who underwent dialysis at centers with seropositive patients. None of the previously seronegative patients seroconverted, yielding an incidence rate of 0% (upper limit of 95% confidence interval = 0.45%). No case of possible nosocomial transmission was identified. CONCLUSION: These results suggest that use of long-standing infection control precautions is effective minimizing the risk of transmission of HIV in hemodialysis settings.

Adolescent↗
PubMed1991

Myositis ossificans progressiva.

Myositis ossificans progressiva is a rare, incurable disease causing progressive ossification of skeletal muscles leading to total immobility. We report one such case.

Adult↗
PubMed1991

Short term effect of diltiazem on portal hypertension in patients with non-cirrhotic portal fibrosis.

Fourteen patients of non-cirrhotic portal fibrosis (NCPF) with portal hypertension were put on oral diltiazem hydrochloride (90 mg/day) or placebo on a prospective, randomised, single blind basis for 15 days. Predrug hemodynamic and biochemical status were similar in both groups. Diltiazem produced significant reduction (p less than 0.001) in mean intrasplenic pressure: from 41.88 (SD +/- 6.18) to 21.5 (+/- 7.91) cm of normal saline as against 45.56 (+/- 9.45) to 43.33 (+/- 8.27) in the placebo group. Mean arterial pressure (MAP), heart rate and cardiac output (CO) did not change in either group. Thus, the calcium channel blocker diltiazem reduces portal pressure in patients with NCPF, independent of reduction in MAP and CO; this is advantageous in situations where compromised cardiac hemodynamics may prove deleterious.

Adult↗
PubMed1990

[3H]mecamylamine binding to rat brain membranes. Studies with mecamylamine and nicotine analogues.

Mecamylamine, an antagonist to nicotine, does not compete at the nicotinic recognition site, but is believed to block the ion channel of the nicotinic receptor. The present study demonstrates specific, saturable [3H]mecamylamine binding in rat brain membranes. [3H]Mecamylamine binding was destroyed by heating at 100 degrees and trypsin. Scatchard analysis revealed the presence of two sites with Kd values of 9.6 x 10(-8) and 1.1 x 10(-6) M and Bmax values of 7 x 10(-12) and 3 x 10(-11) mol/mg protein respectively. A good correlation was observed between the Ki values for [3H]mecamylamine binding of a number of mecamylamine and related analogues and their ability to block nicotine-induced prostration in rats and seizures in mice. Inorganic cations, particularly divalent, and various ion channel blockers, such as phencyclidine and verapamil, exhibited a high affinity for the [3H]mecamylamine site. Although mecamylamine did not block nicotine binding, nicotine and its analogues exhibited a high affinity for the [3H]mecamylamine site, a finding which suggests that nicotine acts directly on ion channels as well as the nicotinic cholinergic recognition sites. The data are consistent with the notion that mecamylamine interacts with the open ion channel of the nicotinic receptor.

Animals↗
PubMed1990

The distribution of some serum protein and red cell enzyme polymorphisms in the Koch ethnic group of West Bengal, India.

Three populations (Poliya, Deshi, and Tiyor) of the Koch ethnic group have been studied for the distribution of three serum protein and four red cell enzyme polymorphisms. There was no significant difference in the allelic frequencies of these systems in the three populations of the Koch ethnic group. The overall gene frequencies were as follows: Hp1, 0.21; Gc1F, 0.34; Gc1S, 0.36; Gc2, 0.30; TfC1, 0.66; TfC2, 0.26; TfC3, 0.001; TfD, 0.06; GLO1, 0.21; PGI2, 0.04; AK2, 0.01; PGM1+, 0.80; PGM1-, 0.06; PGM2+, 0.11 and PGM2-, 0.02. The phenotypic distribution at all the loci was at Hardy-Weinberg equilibrium.

Adenylate Kinase↗
PubMed1990

Technetium-99m amino acid chelates: correlation of their physico-chemical and physiological parameters. Part I.

Ten alpha-aminocarboxylic acids were chelated with 99mTc and purified by sephadex gel chromatography. Their hepatobiliary and renal excretion patterns were determined in rats. It was observed that lipophilicity of these chelates is the only determinant in governing their hepatobiliary excretion, whereas their renal excretion is dependent on some other factors in addition to lipophilicity. Depression of renal excretion in presence of probenecid indicated an interaction of renal tubular transport enzymes with these chelates, which was explained from their hexacoordinated dioxotechnetium (V) chelate structure (II).

Amino Acids↗
PubMed1990

Cysteine, a chelating moiety for synthesis of technetium-99m radiopharmaceuticals: II. Attempt to synthesize renal tubular radiopharmaceuticals.

N-acyl glycine residue is known to interact with renal tubular transport enzymes and thereby promotes renal tubular secretion. Recently, a similar renal property was also observed with dioxotechnetium aminocarboxy chelates. Therefore, a radiopharmaceutical was designed containing both the above groups with the expectation that an efficient 99mTc labelled renal tubular agent could be developed by this process with which evaluation of various renal parameters will be possible. The synthesized compound, though secreted through the renal tubular pathway, did not show the expected efficiency. It was indicated that the renal property of the molecule was entirely due to chelated dioxotechnetium moiety and the expected effect of the acyl glycine residue was not observed in the molecule.

Animals↗
PubMed1990

Quantitative correlations and reexamination of the importance of hydrophobic and steric factors in anticholinergic drug receptor interactions.

The pA2 (or log K) values at the muscarinic cholinergic receptor of the guinea pig ileum for a series of 1,3-dioxolanes have been correlated with the hydrophobic constant pi and pi 2. A correlation coefficient of 0.97 and standard deviation of 0.30 were obtained with 16 of the 18 compounds (P less than 0.05). A series of 17 analogues of amino esters of alpha-methyl tropic acid and alpha-substituted phenyl acetic acids, which were tested in the isolated rat ileal muscle, was analyzed, with a correlation coefficient of 0.92 and a standard deviation of 0.25 (P less than 0.05). Based on these results, the role of hydrophobic forces in the drug receptor interactions of muscarinic cholinergic receptors was analyzed. Optimum values for the physicochemical parameters were determined and their use in enhancing potency was suggested.

Animals↗
PubMed1990

Cysteine, a chelating moiety for synthesis of 99Tcm radiopharmaceuticals. III: Functionalization of hydroxy group for 99Tcm chelation.

A method is offered for converting an organic hydroxy compound to a 99Tcm-binding ligand under mild experimental conditions. Cyclohexanol was selected as a typical hydroxy compound and to this molecule cysteine was attached through substitution at the sulphur atom by a two-step chemical synthesis. The ligand thus obtained could be successfully radiolabelled with 99Tcm. The biodistribution of the resulting radiolabelled compound had the characteristic of a mixed hydrophilic-lipophilic 99Tcm chelate and was similar to that of 99Tcm-HIDA derivatives, a well established class of 99Tcm-chelates. So it may be concluded that the above method of functionalization of a hydroxy compound does not generate any unusual physiological properties and may be recommended as a general method for radiolabelling an organic compound at the alcoholic site with 99Tcm.

Animals↗
PubMed1990

Nucleosome assembly of simian virus 40 DNA in a mammalian cell extract.

We report here a mammalian cell-free system that can support chromatin assembly. Effective nucleosome assembly in HeLa cell extracts occurred at 125 to 200 mM KCl or potassium glutamate. At this physiological K+ ion concentration, two types of chromatin assembly were observed. The first was interfered with by Mg2+. Other cations such as Mn2+, Ca2+, Fe3+, and spermidine also inhibited this type of nucleosome assembly. The second type of assembly occurred in the presence of Mg2+ and at least equimolar ATP. However, even in the presence of ATP, excess Mg2+ inhibited assembly and promoted catenation of DNA; these effects could be circumvented by excess ATP, GTP, EDTA, or polyglutamic acid. The critical DNA concentration for optimum assembly in both pathways suggested a stoichiometric association of histones with DNA. The spacing of nucleosomes formed by both types of assembly on linear and circular DNA was reasonably regular, but chromatin assembled in the presence of ATP and Mg2+ was more stable.

Adenosine Triphosphate↗
PubMed1990

Antisticking protein factors in buffalo blood serum.

Buffalo blood serum is a potent source of antisticking factor (ASF) that inhibits with high affinity adhesion of goat epididymal spermatozoa to the glass surface of hemocytometer counting chamber. The serum is also capable of inhibiting glass-sticking of spermatozoa of the buffalo, ram, and bull. The serum ASF activity is nondialyzable and stable to heat treatment at 100 degrees C for two minutes. The activity of the serum ASF was lost completely when treated with trypsin (50 micrograms/ml) at 37 degrees C for thirty minutes indicating the polypeptide nature of the ASF. Serum ASF activity consists of at least two factors (A and B) as shown by concanavalin A-agarose affinity chromatography. ASF-A and -B represent nearly 75% and 25% of the total serum ASF activity. ASF-B is a glycoprotein as it binds with high affinity to concanavalin A. The sera of species such as man, goat, and rat possess ASF activity.

Animals↗
PubMed1990

Tumor inhibition and hematological improvements by dopamine analog 3,4-dihydroxybenzylamine in mice bearing transplantable carcinoma.

The cancer chemotherapeutic efficacy of 3,4-dihydroxybenzylamine (DHBA), a dopamine analog with reduced neurotoxic effects, was evaluated in strain A mice bearing transplantable Ehrlich's ascites carcinoma. The analog was administered intraperitoneally on day 1 post-transplantation at dose schedules of 50, 100 and 200 mg/kg/day for 7 consecutive days. The results demonstrated a significant inhibition of tumor growth and prolongation of the survival time of EAC tumor bearing mice following DHBA treatment. Diminished activity of the growth-related respiratory enzyme succinate dehydrogenase along with the stimulated activity of the lysosomal enzyme beta-glucuronidase in the DHBA-treated tumor cells indicated inhibition of tumor growth as well as active lysis of the tumor cells. Tumor inhibition was accompanied by marked improvements in hemoglobin concentration. RBC count and bone marrow cellularity. The results demonstrated that DHBA did not adversely affect hematological profile of the host while it inhibited the growth of Ehrlich's ascites carcinoma.

Animals↗