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Biomedical subjects

S Sengupta

Publications and source records attributed to S Sengupta.

At least 199 records · Page 11Linked to original sources
PubMed1991

Role of adrenergic and cholinergic mediators in gastric mucus phospholipid secretion.

The role of adrenergic and cholinergic mediators in phospholipid secretion by gastric mucosal cells maintained in the presence of [3H]choline was investigated. The secretion of [3H]choline phospholipids over 30 min period averaged 1.98% of the total cellular labeled phospholipids in the absence of any mediator, and was enhanced by beta-adrenergic agonist, isoproterenol, to a greater extent than the cholinergic agonist, pilocarpine. A 2-fold increase in phospholipid secretion was achieved with isoproterenol, while pilocarpine evoked 1.3-fold increase. The stimulatory effect of isoproterenol was inhibited by alprenolol and that of pilocarpine by atropine. The phospholipids secreted in response to isoproterenol exhibited a 30% decrease in lysophosphatidylcholine, while 2.1-fold enrichment in this phospholipid occurred with pilocarpine. The results, for the first time, demonstrate the involvement of neural mediators in the regulation of phospholipid secretion in gastric mucus.

Alprenolol↗
PubMed1991

Chlamydia trachomatis in pelvic inflammatory disease.

C. trachomatis seems to be an important causative organism of pelvic inflammatory disease (PID) as C. trachomatis antigen and/or antibody was found in 234 (69.85%) of 335 patients clinically diagnosed to have PID. Antigen was detected in the lower genital tract of 118 (35.22%) patients whereas IgG antibody was present in 188 (56.11%), of whom 89 (47.34%) had a high titre. Repeat testing of sera of 37 patients showed a rise in antibody titre in 18 (40%). As the success rate of therapy for PID with doxycycline was found to be 80 per cent, early diagnosis and treatment may be recommended to prevent further complications of PID.

Adult↗
PubMed1991

Characterization of gingival epithelium epidermal growth factor receptor.

The binding characteristics of gingival epithelium epidermal growth factor (EGF) receptor were investigated using epithelial cell membranes from bovine gingiva. The binding of [125I]EGF was found to be time and protein concentration dependent, reversible, and specific. Unlabeled EGF competed for [125I]EGF binding with IC50 of 0.25nM and maximum displacement of 93% at 0.81nM. Scatchard analysis of the binding data inferred the presence of two binding sites, one of high affinity (Kd = 3.3 nM and Bmax = 47.3fmol/mg protein) and the other of a low affinity (Kd = 1.6 microM and Bmax = 1.9pmol/mg protein). Crosslinking of [125I]EGF to gingival membranes followed by polyacrylamide gel electrophoresis and autoradiography revealed a receptor protein of 170kDa.

Animals↗
PubMed1991

Protein profile and stimulation potential of partially purified lectins from two varieties of Phaseolus vulgaris L.

Phytohaemagglutinin obtained from P. vulgaris is a commonly used mitogen in lymphocyte cultures. The mitogenic potential of different cultivars of P. vulgaris vary. The present investigation encompasses the characterization of partially purified lectins from two varieties of P. vulgaris on the basis of their protein profile, lymphocyte transformation test by light and scanning electron microscopy and incorporation of radioactive thymidine.

Cells, Cultured↗
PubMed1991

Perinatal outcome following improvement of abnormal umbilical artery velocimetry.

Umbilical artery velocimetry was investigated to determine whether abnormal flow patterns improved with bed rest and if the prognosis of the pregnancy was different in the improved groups. Abnormal flow waveform was defined as a systolic-diastolic ratio (S/D) above the 95th percentile of established normal values. One hundred twenty-eight women had abnormal waveforms. They were placed on bed rest in the left lateral position and monitored by biophysical profile and growth indices. Sixty-six subjects (51.5%) reverted to normal flow waveforms following bed rest, at a mean (+/- SD) interval of 4.5 +/- 1.5 weeks (range 3-10), and 62 (48.5%) exhibited persistent abnormal flow. None of the improved group exhibited fetal distress or perinatal mortality, whereas in the group with persistent abnormal flow, 15 (24%) experienced fetal distress and 13% experienced perinatal mortality. The diagnosis-to-delivery interval in the improved group was 63 +/- 14 days, versus 26 +/- 21 days in the unimproved group, and the mean gestational age at delivery was 37.3 +/- 2.0 versus 32.8 +/- 3.6 weeks, respectively (P less than .0001). We conclude that a subset of patients with abnormal Doppler velocimetry findings will improve on bed rest and have a better perinatal outcome, whereas persistence of abnormal flow defines a group of patients who are at risk for poor perinatal outcome and who require intensive monitoring and intervention.

Bed Rest↗
PubMed1991

Genetic investigations among the Ahom of Assam.

The Ahom has been investigated for the distribution of ABO blood groups, phenylthiocarbamide taste sensitivity, earlobe attachment and age at menarche. The present sample of Ahom displays a good amount of homogeneity with most of the neighbouring mongoloid population. Only biological features that set apart Ahom from other mongoloid populations is earlobe attachment types. It is quite possible that the higher frequency of phenotype B among the Ahom may be due to the gene flow from the surrounding caste (Indid) populations as a result of admixture.

ABO Blood-Group System↗
PubMed1990

Search for chromosomal variations among gas-exposed persons in Bhopal.

A chromosomal survey using standard lymphocyte cultures employing different media and G-banding techniques was initiated in 1984. This study became particularly important following the tragic gaseous exposure of the population in Bhopal at midnight on 2 December 1984. We have been able to formulate a chromosomal profile for each person whom we have studied; during 1986-1988, 154 persons were examined twice. Among seemingly normal individuals, as many as 20% might possess some chromosomal abnormality; of these, 50% may develop, at a later date, some kind of pathological complication (such as tumours, recurrent abortion or transmission of defects to their offspring). The people exposed to methyl isocyanate have repeatedly shown Robertsonian translocations, mostly in acrocentric chromosomes 13 and 21. Other types of translocations have been studied among all exposed (53) and normal (101) persons; the involvement of chromosomes 5, 9, 11, 14 and 16 is statistically significant (P = less than 0.001). One of the major clinical symptoms is dyspnoea; we have estimated that almost all seriously dyspnoeic patients have developed at least two categories of chromosomal aberrations, one of which is Robertsonian translocation, in at least 10% metaphases. Our chromosomal survey will be of significance because we are able to identify people with chromosomal aberrations that might be correlated with future pathological consequences of the accident. The "chromosomal load" that can be sustained with an apparently normal phenotype can also be measured.

Accidents, Occupational↗
PubMed1990

Within-mouth correlations for indicators of the host response in gingival crevicular fluid.

Gingival crevicular fluid was collected from multiple sites in patients with chronic adult periodontitis, and analysed for the lysosomal enzymes beta-glucuronidase and arylsulphatase, the cytoplasmic enzyme lactate dehydrogenase, total IgA, IgG and IgM and the protease inhibitor alpha 2-macroglobulin. The within-mouth (intraclass) correlation coefficients were calculated to describe the relationship between samples collected from individual patients. Data collected at baseline and 3 months after root planing and scaling were analysed, as was the change between examinations. Volume of crevicular fluid demonstrated the smallest intraclass correlation coefficient (0.16 at baseline, 0.12 at 3 months; 0.11 change), while probing depth and enzyme activity had moderate intraclass correlations (i.e. 0.36, 0.36, 0.26 for beta-glucuronidase). Immunoglobulin and alpha 2-macroglobulin activity in the fluid had the strongest correlations (i.e. 0.64, 0.57, 0.65 for IgG). The correlations for anatomically related teeth within a quadrant (molar, non-molar) were equivalent to or greater than the correlation for all samples within a mouth. Examined by tooth type, the intraclass correlations for volume of crevicular fluid, probing depth, beta-glucuronidase, arylsulphatase and lactate dehydrogenase were higher for non-molar teeth. In contrast, intraclass correlations for IgA, IgG, IgM and alpha 2-macroglobulin in samples from molar teeth were either equivalent to or greater than the correlations for non-molar samples. Calculation of intraclass correlation coefficients for such data can (1) indicate the degree of variability present in multiple samples of crevicular fluid collected from individual patients, (2) provide information about the source of host mediators in the fluid, and (3) help identify appropriate sampling strategies for the fluid.

Adult↗
PubMed1990

The relationship of prostaglandins to cAMP, IgG, IgM and alpha-2-macroglobulin in gingival crevicular fluid in chronic adult periodontitis.

Gingival crevicular fluid, collected from 8 patients with chronic adult periodontitis before and 21 days after root planing and scaling, was analysed for prostaglandin E2, 6KPGF1 alpha, cAMP, IgG, IgM and alpha-2-macroglobulin, and their inter-relationship evaluated. There was a significant decrease in the levels of prostaglandin E2, IgG, IgM and alpha-2-macroglobulin after treatment, whereas the levels of 6KPGF1 alpha and cAMP remained essentially unchanged. The level of prostaglandin E2 decreased by 35%, IgG by 32%, IgM by 90%, and alpha-2-macroglobulin by 79%. There was a significant degree of correlation between prostaglandin E2 and 6KPGF1 alpha and cAMP before treatment but not after, but no correlation between prostaglandin E2 and IgG, IgM and alpha-2-macroglobulin either before or after. This correlation pattern indicates the involvement of E2, prostaglandin 6KPGF1 alpha and cAMP in inflammation in the periodontium. The changes in IgG, IgM and alpha-2-macroglobulin reflect yet another mechanism of host response which appears to be independent of prostaglandins.

6-Ketoprostaglandin F1 alpha↗
PubMed1990

Effect of lipids on the lactic acid retardation capacity of tooth enamel and cementum pellicles formed in vitro from saliva of caries-resistant and caries-susceptible human adults.

The lipid content and composition of these pellicles and the effect of lipids on their ability to retard the diffusion of lactic acid were investigated. Lipids accounted for 22.4% of the dry weight of caries-resistant enamel pellicle and 19.2% of caries-resistant cementum pellicle; the pellicle of caries-susceptible enamel contained 24.6% lipids and that of caries-susceptible cementum, 23.4%. Enamel and cementum pellicles from caries-resistant saliva had a significantly lower content of neutral lipids and phospholipids, whereas the glycolipid content was lower, although not significantly, in caries-susceptible pellicles. Pellicles from caries-resistant saliva had a considerably greater capacity to retard lactic acid diffusion than those from caries-susceptible saliva. In all cases, the retardation capacity was clearly dependent upon the lipid constituents, removal of which caused a 50-52% drop in lactic acid impedance by caries-resistant enamel and cementum pellicles, and 32-35% drop by caries-susceptible pellicles. On reacting the delipidated pellicles with their lipids, it was found that, in all cases, the highest quantitative effect on the restoration of the retardation capacity occurred when phospholipids were added. The findings suggest that the events controlling the interaction of salivary phospholipids with enamel and cementum may determine the susceptibility of the tooth surface to demineralization by acids produced by cariogenic micro-organisms.

Adult↗
PubMed1990

Effects of low-dose hydrogen peroxide treatment of V79 cells on killing and mutation by different agents.

Benzamide (BA) prevented the induction of repair resulting from a small dose of H2O2 pretreatment of V79 cells. Such pretreatment with H2O2 increased the mutation yield by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or gamma-rays, indicating the error proneness of the induced repair activity. Cycloheximide or BA could suppress the increase in the mutation yield. This induced repair function had no effect on the lesions by ultraviolet light and persisted for about 20 h after which it declined.

Animals↗
PubMed1990

DNA damage and prophage induction and toxicity of nitrofurantoin in Escherichia coli and Vibrio cholerae cells.

Repair-deficient and repair-proficient strains of E. coli K12 were sensitive to nitrofurantoin treatment to varying degrees with the double mutant strain (uvrA 6, recA 13) being most sensitive. Ultraviolet absorption data and thermal chromatography through a hydroxyapatite column revealed that nitrofurantoin treatment of V. cholerae strain OGAWA 154 produced a maximal amount of 55% reversibly bihelical DNA at a nitrofurantoin dose of 120 micrograms/ml/h, which indicated the formation of inter-strand cross-links in DNA. Nitrofurantoin also produced prophage-lambda induction in E. coli K12 strain GY 5027: envA, uvrB, ampA 1, strA (lambda), in a dose-dependent manner, the maximum induction being highly significant (P less than 0.001). Previously published mutation data coupled with the prophage induction data presented here suggest that the genotoxic properties of nitrofurantoin are mediated through the SOS pathway.

Bacteriophage lambda↗
PubMed1990

Cytogenetic studies in human populations exposed to gas leak at Bhopal, India.

Frequencies of chromosomal abnormalities, sister chromatid exchanges, and replicative index were assessed following peripheral lymphocyte culture in 129 individuals from Bhopal, India. Of these, 83 persons (40 male and 43 female) had been exposed directly to the methyl isocyanate (MIC) gas after the accident at the Union Carbide plant on December 2 and 3, 1984. The remaining 46 samples were taken from age-matched unexposed persons in the same city. Chromosome aberrations were recorded at first cycle metaphase (M1) and sister chromatid exchanges, at second cycle metaphase (M2), following standard schedule. The frequency of chromosomal aberrations was, in general, higher in individuals from the exposed populations, with the females showing a higher incidence. Nondisjunction of chromosomes or laggard was rare. The frequencies of sister chromatid exchanges and depression in mitotic and replicative indices could not be related to exposure or sex. The persistence of chromosomal abnormalities in the form of replicating minutes and exchange configurations, even 1114 days after exposure to the gas, may indicate a residual effect on T-cell precursors.

Accidents, Occupational↗
PubMed1988

The effect of treatment on IgG, IgA, IgM and alpha-2-macroglobulin in gingival crevicular fluid from patients with chronic adult periodontitis.

With a technique for sampling, processing and analysis of gingival crevicular fluid (GCF) that allows multiple constituents to be analysed from a sample collected on a filter paper strip, we have examined IgG, IgA, IgM and alpha-2-macroglobulin (alpha 2M) in GCF from patients with chronic adult periodontitis. Clinical data and GCF were collected before and 3 months after root planing and scaling, and analysed to determine trends for the population. A statistically-significant decrease in the percentage of sites with bleeding on probing, erythema and supragingival plaque was observed 3 months after therapy. The mean amount of each glycoprotein in GCF decreased dramatically at 3 months. In contrast, the mean volume of GCF was virtually identical at the two evaluations. The IgG/IgA and IgG/IgM ratios in GCF were elevated when compared with human serum suggesting the preferential occurrence of IgG in GCF. Correlation of the four glycoproteins with GCF volume and with enzyme markers of the acute inflammatory response in GCF revealed a relationship between arylsulphatase (a lysosomal enzyme), fluid influx, and the passage of larger molecular-weight glycoproteins (alpha 2M, IgM) into the gingival crevice.

Adult↗
PubMed1988

Delayed management of fracture of the lateral humeral condyle in children.

Thirty-nine displaced fractures of the lateral humeral condyle in children were followed for an average of 5 (2-5) years. The results were evaluated from functional and cosmetic aspects. Patients treated within 2 weeks by open reduction and internal fixation did well. Those operated on after 6 weeks did not do better than nonoperated on cases. Complications included cubitus varus and valgus deformities, osteonecrosis, nonunion and malunion, and loss of motion. We recommend that patients presenting late be left alone and any sequelae evaluated at a late stage.

Bone Wires↗