Search PubMed⌕ Search

Biomedical subjects

S Banerjee

Publications and source records attributed to S Banerjee.

At least 397 records · Page 22Linked to original sources
PubMed1994

Low prevalence of Helicobacter pylori in inflammatory bowel disease: association with sulphasalazine.

The prevalence of IgG antibodies to Helicobacter pylori was examined in 110 patients with inflammatory bowel disease (IBD) (63 ulcerative colitis, 47 Crohn's disease) and compared with 100 age and sex matched control patients. The overall prevalence of H pylori seropositivity in the IBD patients was 22%, which was significantly less than that of 52% in the controls (p < 0.002). There was no difference in prevalence between ulcerative colitis and Crohn's patients. The low seropositivity in the IBD patients resulted from a very low prevalence of 10% in those currently receiving sulphasalazine (n = 40) and similarly low prevalence of 7% in those previously receiving sulphasalazine (n = 30). In those receiving olsalazine or mesalazine and who had never had sulphasalazine, the prevalence of seropositivity was 45%. Further studies using 14C urea breath test and microscopy of antral biopsy specimens confirmed that the negative serology in patients receiving sulphasalazine resulted from absence of the infection rather than absence of humoral immune response to it. In six control patients with H pylori infection, a two week course of sulphasalazine (500 mg four times daily) only caused slight suppression of the 14C urea breath test. In vitro studies failed to show any direct antibacterial effect of sulphasalazine on H pylori. These findings indicate that longterm treatment with sulphasalazine leads to eradication of H pylori infection and that this does not result from a direct antibacterial effect. It may be caused by the drug treating the gastritis and thereby depriving the bacterium of essential nutrients exuded by the inflamed mucosa.

Adult↗
PubMed1994

Effect of Helicobacter pylori and its eradication on gastric juice ascorbic acid.

The presence of ascorbic acid in gastric juice may protect against gastric carcinoma and peptic ulceration. This study examined the effect of Helicobacter pylori (H pylori) on the secretion of ascorbic acid into gastric juice by measuring fasting plasma and gastric juice ascorbic acid concentrations in patients with and without the infection and also before and after its eradication. Gastric juice ascorbic acid concentrations in 19 H pylori positive patients were significantly lower (median 2.8, range 0-28.8 micrograms/ml) than those in 10 H pylori negative controls (median 17.8, range 5.6-155.4 micrograms/ml) (p < 0.0005) despite similar plasma ascorbic acid concentrations in both groups. The median gastric juice:plasma ascorbic acid ratio in the H pylori positive patients was only 1.16 (range 0.02-6.67), compared with a median ratio of 4.87 (range 0.76-21.33) in H pylori negative controls (p < 0.01). In the patients with H pylori infection there was a significant negative correlation between the severity of the antral polymorphonuclear infiltrate and gastric juice ascorbic acid concentrations (correlation coefficient -0.52, p = 0.02). After eradication of H pylori in 11 patients, gastric juice ascorbic acid concentrations rose from 2.4 (0-12.8 micrograms/ml) to 11.2 (0-50 micrograms/ml) (p = 0.01). The median gastric juice: plasma ascorbic acid ratio also increased from 1.33 (0.05-6.67) to 2.89 (0.01-166) (p = 0.01). In conclusion, the high gastric juice:plasma ascorbic acid ratio in H pylori negative subjects shows active secretion of ascorbic acid into gastric juice. Secondly, H pylori infection causes a reversible lowering of gastric juice ascorbic acid concentrations, which may predispose to gastric carcinoma and peptic ulceration.

Ascorbic Acid↗
PubMed1994

Alterations of brain serotonin during experimental tumor growth in mice.

Concentrations of serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) were studied in discrete areas of brain and in large intestine of Swiss mice following transplantation of Sarcoma 180 (S 180) ascites tumor. Significant increase in 5-HT levels (2 to 3.5-fold over controls, P < 0.05) was observed in raphe region of the brain throughout the period of tumor growth. Concomitant increase, although of lesser magnitude, was recorded in raphe 5-HIAA content. 5-HT content of hypothalamus, mid brain and caudate putamen, on the other hand, remained relatively unaltered except for an increase at the advanced stage of the disease. While mid brain and hypothalamic 5-HIAA were elevated at the late stage, 5-HIAA values of caudate putamen were normal or slightly reduced during the progression of tumor. Both 5-HT and 5-HIAA levels of the large intestine showed an early decline followed by a modest increase at the late stages. Brain and plasma tryptophan levels were also elevated significantly (P < 0.05) in the tumor hosts. The results suggest a close relationship between increase in serotonin concentrations in the brain, particularly in raphe region, and the progression of S-180 tumor in mice.

Animals↗
PubMed1994

Dinucleotide repeat polymorphisms at nine loci in sporadic colorectal cancer.

Genomic instability in the form of microsatellite alterations at nine loci on chromosomes 2p, 8p, 10p, 11p, and nm23-H1 locus on 17q21.3 were studied in sporadic colorectal tumors. Alterations in dinucleotide repeats in tumor DNA as larger allele, smaller allele, or loss of heterozygosity (LOH) were observed. Forty percent of tumor showed an RER+ phenotype. A significantly high number of alterations was detected at loci of chromosome 8p. The markers on chromosomes 2p, 10p, and 11p did not show such significant alteration. LOH was found to be associated with the nm23-H1 locus. No correlation was found between the age, site of tumor occurrence, or metastasis and the microsatellite instability.

Adenocarcinoma↗
PubMed1994

The role of nm23 in transforming growth factor beta 1-mediated adherence and growth arrest.

nm23 has properties of a metastasis suppressor gene and also has been implicated in the control of response to transforming growth factor beta 1 (TGF beta 1) by studies in melanoma cells. In this report, we have examined the role of nm23 in two HT29 colon carcinoma sublines at different stages in tumor progression with different responses to TGF beta 1: the HD3 subline, which shows TGF beta 1-induced growth arrest and differentiation; and the more invasive and tumorigenic U9 subline, which induces tumors 7-fold as large as those induced by HD3 cells with one-half the latency. Analysis by semiquantitative reverse transcription-polymerase chain reaction showed that antisense phosphorothiolated oligonucleotides to the nm23 initiation site (nm23 AS oligos) decreased nm23 mRNA levels 2-8-fold in HD3 and U9 cells when normalized to beta-actin mRNA levels. However, a role for nm23 in TGF beta 1-mediated responses could only be found in HD3 cells. nm23 AS oligos inhibited the differentiation property of cell adherence over 90% in HD3 cells, and this loss of adherence could be partially blocked by concurrent treatment with TGF beta 1. In contrast, U9 cell adherence was not detectably altered by nm23 AS oligos, whether added in the presence or absence of TGF beta 1. The TGF beta 1-induced inhibition of HD3 cell proliferation was blocked by nm23 AS oligos, whereas the TGF beta 1-induced proliferation of U9 cells was unaffected by nm23 AS oligos.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1994

Humoral immunity response in malignancies with special reference to the effect of radiotherapy.

In view of the variability in the findings recorded by different authors in the level of immunoglobulins in patients suffering from malignancies, a study on 34 cases of six types of malignancies treated with radiotherapy (telecobalt and telecesium) was carried out to record the humoral response and also to compare the response during radiotherapy and after radiotherapy in these cases. Serum of 20 age-matched normal volunteers served as normal control. The study recorded that the pretherapy levels of IgA and IgG were raised in most of the cases; but the IgM was decreased than that of the control level. This is probably due to the fact that the selective clones of cells producing different types of immunoglobulins are responding to the malignancies in different ways. The midtherapy level of all immunoglobulins showed the value lower than the pretherapy level, but recovery was observed in the post-therapy period with all immunoglobulins in all the cases irrespective of the histological types of malignancies. It was also apparent from this study that the post-therapy gain in the level of immunoglobulins over midtherapy level was more pronounced in cases having telecobalt therapy. Assessment of humoral response in 25 patients suffering from squamous cell carcinoma of different grades revealed that the midtherapy fall and subsequent post-therapy gain had no definite correlation with grading.

Adult↗
PubMed1994

Absence of HTLV-I infection in some Indian populations.

A total of 946 adults belonging to ten population groups of Uttar Pradesh and West Bengal were screened for HTLV-I using a gelatin particle agglutination test. The percentage of seroreactive cases varied from 0 to 5.8 per cent. The overall prevalence of seroreactivity was 2 per cent. Of the 19 seroreactive cases, 15 were subjected to Western blot analysis, none could be confirmed. HTLV-I infection is, therefore, absent in these populations.

Adolescent↗
PubMed1994

99Tcm-cystine, a renal function and imaging agent: a comparative study in dog with 131I-hippurate and 99Tcm-glucoheptonate to evaluate its functional and imaging characteristics.

99Tcm-cystine, which has been proposed as a renal radiopharmaceutical for evaluating renal morphology and function in a single experiment, is compared with 131I-orthoiodohippurate (OIH) with respect to its renal clearance and extraction parameters and with 99Tcm-glucoheptonate (GHA) regarding its imaging characteristics. In spite of its comparable renal accumulation with 131I-OIH, its clearance (10.1 +/- 1.0 ml min-1 kg-1) was lower than that of 131I-OIH (21.5 +/- 0.9 ml min-1 kg-1) but was higher than that of 125I-iothalamate (5.4 +/- 0.6 ml min-1 kg-1). Extraction efficiencies of 99Tcm-cystine, 131I-OIH and 125I-iothalamate were 39 +/- 5, 64 +/- 4 and 27 +/- 3, respectively. The glomerular filtration components of 99Tcm-cystine and 131I-OIH were 26 and 16% of their respective clearances. In probenecid-treated animals the clearance of both agents was affected to a similar extent and fell to half of their respective control values, whereas tubular secretory components were found to be 19 and 31% of the controls. The kidney images obtained with 99Tcm-cystine were superior to those obtained with 99Tcm-GHA at different time points. Therefore, considering both renal function and imaging properties of 99Tcm-cystine it appears that this radiopharmaceutical offers some definite advantages over the currently available renal agents and commands further study.

Animals↗
PubMed1994

The intraosseous route is a suitable alternative to intravenous route for fluid resuscitation in severely dehydrated children.

It is sometimes difficult to gain a rapid intravenous access in hypovolemic states. The suitability of intraosseous (IO) route for fluid infusion as an effective, safe and reliable alternative to intravenous (IV) route was explored. Sixty children (age range 3 months to 2 years) with severe dehydration were assigned alternately to receive resuscitating fluid through either IO or IV routes. The IO route was successfully secured in all cases within the first 5 minutes of attempt. On the other hand, the IV line could not be secured in 33% (10 out of 30) patients within 5 minutes. The time taken for IV cannulation when it was successful (129 +/- 13 seconds, 95% confidence interval 103-156 seconds) was significantly longer than the time taken for IO cannulation (67 +/- 7 seconds, 95% confidence interval 55-80 seconds). Fluid infusion through either routes was equally effective in stabilizing vital signs and normalizing laboratory abnormalities. No significant complication of IO route was noted on short term follow-up. We conclude that IO route is a safe, effective alternative for emergency fluid administration in severe dehydration when intravenous line cannot be secured rapidly.

Acidosis↗
PubMed1994

Microsatellite instabilities at five chromosomes in primary breast tumors.

The microsatellite instabilities at nine loci of chromosomes 2p, 8p, 10p and 11p and the nm23-H1 locus on 17q21.3 were studied in primary breast tumors. Alterations in the short interspersed tandem repeats in tumor DNA in the form of either larger allele, smaller allele or LOH were observed. Significantly, a high occurrence of alterations in microsatellite polymorphisms at the ANK1, D8S135 and LPL loci of chromosome 8p (46-54%), the D2S119 locus of chromosome 2p (56%), the D10S197 locus at chromosome 10p (88%), and the nm23-H1 locus of chromosome 17q21.3 (46%) were observed in breast tumors. These results provide the first evidence for genomic instabilities at 2p, 8p and 10p in primary ductal and lobular breast carcinomas. No correlation has been found between the stage of the tumor and microsatellite instability, suggesting that microsatellite instability is an early genetic event in breast carcinogenesis.

Breast Neoplasms↗
PubMed1994

Isolation and characterization of the promoter region of human nm23-H1, a metastasis suppressor gene.

Allelic deletions in the nm23, a metastasis suppressor gene, are known to occur in neuroblastomas, breast and colorectal carcinomas. Down-regulation of nm23 expression has been reported in various rodent and human tumor cells with high metastasis phenotype. Colorectal tumors showed overexpression of nm23. To elucidate the regulatory mechanisms of nm23, we isolated, cloned and sequenced the presumptive regulatory DNA fragment spanning the 5' region of the human nm23-H1 gene. The region's nucleotide sequence shows the presence of motifs typical for transcriptional elements such as TFIID, AP-1 and CTF/NF1. A common transcription initiation site is located at -136 upstream from the first ATG codon in placenta tissue, in breast, colorectal, prostate tumor cell lines and in primary colorectal tumor. Multiple transcription start sites were identified in tumor cell lines and colorectal tumor. When the promoter element was linked to a reporter gene, chloramphenicol acetyltransferase (CAT) and transfected in human 2fTGH cells, strong CAT activity was detected, which also showed that the presence of AP-1 and CTF/NF1 elements are essential for promoter activity. A detailed study of the structure and function of the promoter element of the nm23-H1 gene will help in understanding the regulatory mechanisms of nm23 expression and its role in tumor progression, especially in metastasis.

Base Sequence↗
PubMed1993

Mutation in the nm23 gene is associated with metastasis in colorectal cancer.

The human nm23 gene, a candidate metastatic suppressor gene, consists of two genes, nm23-H1 and nm23-H2. The potential mutation in the nm23-H1 gene was examined in colorectal cancer using a reverse transcription polymerase chain reaction amplification followed by DNA sequencing analysis. Genomic alterations in the nm23 gene were also examined by Southern hybridization. Genetic alterations either as a deletion in the coding sequence of nm23-H1 or as an allelic deletion were detected in four among eight colorectal adenocarcinomas associated with metastases in lymph nodes, lung, or liver. No alteration was observed in 12 additional colorectal cancer specimens without metastasis. These results provide first evidence for novel mutation in the nm23 gene and demonstrate a correlation between the mutation in the nm23 gene and metastasis in colorectal oncogenesis which suggests that the nm23 gene plays a role in the causation of metastasis.

Alleles↗
PubMed1993

Transformation of cholic acid by Arthrobacter simplex.

Fermentation of cholic acid with Arthrobacter simplex (IICB 227) under aerobic conditions yielded 3,12-dioxo-23,24-dinorchola-4,6-dienoic acid, 7 alpha-hydroxy-3,12-dioxo-23,24-dinorchol-4-enoic acid, 3 alpha, 7 alpha-dihydroxy-12-oxo-5 beta-cholan-24-oic acid, 3 alpha, 7 alpha-dihydroxy-12-oxo-5 beta-23,24-dinorcholan-22-oic acid, 7 alpha, 12 alpha-dihydroxy-3-oxo-5 beta-cholan-24-oic acid, 7 alpha-12 alpha-dihydroxy-3-oxo-4-cholenoic acid, 7 alpha, 12 alpha-dihydroxy-3-oxo-23,24-dinorchol-4-enoic acid, and methyl-3 alpha-7 alpha, 12 alpha-trihydroxy-5 beta-cholan-24-oate in addition to a new metabolite 2 beta-hydroxy-3,12-dioxo-23,24-dinorchola-4,6-dienoic acid. Each microbial metabolite was characterized by the application of various spectroscopic methods. The availability of some of the metabolites' enabled complete elucidation of their 13C NMR spectra.

Aerobiosis↗
PubMed1993

99mTc-HMPAO single photon emission tomography in late life depression: a pilot study of regional cerebral blood flow at rest and during a verbal fluency task.

Relative regional cerebral blood flow (rCBF) was measured at rest and during a verbal fluency task in ten elderly patients with major depressive disorder and nine controls. At rest, depressed patients showed significant reductions in the cortico-cerebellar ratios of tracer uptake in the right and left parietal, left temporal and left occipital regions. During the task relative rCBF increased in patients such that these differences disappeared. Relative rCBF did not correlate with severity of depressed mood or endogenous features but did correlate positively with severity of psychotic symptoms. Frontal relative rCBF correlated negatively with somatic symptoms and anxiety.

Aged↗