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Biomedical subjects

S Banerjee

Publications and source records attributed to S Banerjee.

At least 37 records · Page 2Linked to original sources
PubMed1992

Myocardial changes in neonates dying of asphyxia neonatorum.

Ten neonates, asphyxiated at birth, were studied by Apgar score, ECG ischaemic score grading (ECGisg), Cardiothoracic (CT) ratio, biochemical parameters like CPK, CPK-MB fraction during life; and they were subjected to postmortem study with particular attention to the changes in the heart. The study revealed that 7 out of 10 asphyxiated neonates showed variable evidences of myocardial damage; but the extent of damage though well correlated with biochemical parameters, did not correspond well with the extent of asphyxia and the survival period. In rest 3 cases, myocardial damage was not overt though there was evidence of asphyxia and evidence of myocardial damage in the form of elevated CPK-MB level. These patients probably had died of "Biochemical Lesion" as described by Rudolf Peter.

Asphyxia Neonatorum↗
PubMed1992

Down-regulation of ras and myc expression associated with mdr-1 overexpression in adriamycin-resistant tumor cells.

The murine melanoma tumor cells, B16-BL6, are a recognized model for experimental and spontaneous metastasis. B16-BL6 cells express a lower metastatic phenotype upon acquisition of resistance to adriamycin. Using this novel system, the role of ras, c-myc, and multidrug-resistant gene (mdr1) expression in the metastatic and drug-resistant phenotype was examined. The metastatic cells expressed a high level of c-Ki-ras and c-myc, whereas down-regulation of both proto-oncogenes was observed in the adriamycin-resistant cells. The mdr1 gene, which encodes P-glycoprotein of the drug-resistant superfamily gene, was overexpressed in drug-resistant melanoma cells. These results suggest that altered expression of genes that regulate cellular proliferation and growth may be a determinant of metastasis and drug sensitivity of tumor cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1992

Seroprevalence survey of borreliosis in children with chronic arthritis in British Columbia, Canada.

A seroprevalence survey using an indirect immunofluorescence assay (IFA) for IgG antibodies to Borrelia hermsii and Borrelia burgdorferi was conducted for varied pediatric chronic arthritis patients and a nonrheumatic control group in the province of British Columbia, Canada. Overall, a higher rate of sera with IFA titers > or = 1/256 was found for B. hermsii (36.6%) compared to B. burgdorferi (12.5%). There were no significant differences among the arthritis subgroups and controls for the distribution of IFA titers for either organism. IgG immunoblotting of selected high titered sera to either borrelia species confirmed the lack of specificity of the IFA assay. Serological tests for borreliosis should be cautiously interpreted in children with chronic arthritis.

Adolescent↗
PubMed1992

Haptoglobin subtypes in a Bengalee population sample.

HP1 subtyping has been performed on a Bengalee population sample of heterogeneous caste composition. The total sample size comes to n = 140 nonrelated adult individuals (68 males, 72 females). The following allele frequencies were observed: HP*1F = 0.0714, HP*1S = 0.1178, and HP*2 = 0.8107. It can be pointed out that the HP subtype distribution pattern found in the Bengalee sample follows in general the Oriental distribution pattern, though some differences are seen, especially concerning the HP*1F frequency.

Alleles↗
PubMed1992

Genetic study of five populations of Bihar, India.

Four-hundred fifty-nine people, including 106 Santals, 43 Bhuiyas, 107 Sakaldipi Brahmins, 108 Chamars, and 95 Ansari Muslims, of the Giridhi district of Bihar have been tested for transferrin, group-specific component, phosphoglucomutase subtypes, and glyoxalase-I, 6-phosphogluconate dehydrogenase, and adenylate kinase types. Genetic distance estimates by both dendrogram and principal component methods for these 5 populations and the Oraons on the basis of 19 alleles at 6 polymorphic loci indicate 2 major clusters: Brahmins and Muslims, the latter of which is composed of two subclusters (Santals and Bhuiyas, and Oraons and Chamars). The Santal and Bhuiya tribes both speak Mundari, whereas the Oraons speak a Dravidian language. The Chamars, although low-caste Hindus, seem to have a non-Europoid origin, as do the Oraons.

Adenylate Kinase↗
PubMed1992

Immunity to cartilage proteoglycans.

Cartilage proteoglycans constitute a major component of articular cartilage. Humoral and cell-mediated immune responses to these proteoglycans have been observed in various human rheumatic diseases with varying incidences. The possibility of such autoimmune responses being of pathologic significance has been raised by the observation of the induction of arthritis in animals on immunization with proteoglycans. Immunization of BALB/c mice with human cartilage proteoglycan in adjuvant leads to the development of peripheral arthritis as well as spondylitis associated with immune reactivity to mouse cartilage proteoglycan. Pathogenic autoimmune reactions to cartilage proteoglycans may also be elicited by molecular mimicry with bacterial heat shock proteins.

Animals↗
PubMed1992

Inhibition of type II collagen induced arthritis in mice by an immunosuppressive extract of Tripterygium wilfordii Hook f.

The effects of Tripterygium wilfordii Hook f (TWHf), a Chinese herbal remedy, on type II collagen induced arthritis (CIA) in DBA/1LacJ mice were determined. Mice were divided into 4 groups receiving oral treatment for 63 days: Group A, sham feedings; Group B, TWHf (78 mg/day); Group C, TWHf (140 mg/day); Group D, TWHf (140 mg/day) starting 21 days after collagen immunization. Arthritis incidence was reduced and day of onset delayed in Groups B and C compared with A. Arthritic joint counts, arthritic severity scores, and anticollagen antibody titers were decreased in Groups B, C, and D compared with A. Histopathology revealed destructive arthritis only in Group A. Our results indicate that TWHf is a potent immunosuppressive inhibitor of CIA, even when treatment is begun 3 weeks after immunization.

Animals↗
PubMed1991

ATP dependent histone phosphorylation and nucleosome assembly in a human cell free extract.

Physiologically spaced nucleosome formation in HeLa cell extracts is ATP dependent. ATP hydrolysis is required for chromatin assembly on both linear and covalently closed circular DNA. The link between the phosphorylation state of histones and nucleosome formation has been examined and we demonstrate that in the absence of histone phosphorylation no stable and regularly spaced nucleosomes are formed. Phosphorylated H3 stabilizes the nucleosome core; while phosphorylation of histone H2a is necessary to increase the linker length between nucleosomes from 0 to approximately 45 bp. Histone H1 alone, whether phosphorylated or unphosphorylated, does not increase the nucleosome repeat length in the absence of core histone phosphorylation. Phosphorylations of H1 and H3 correlate with condensation of chromatin. Maximum ATP hydrolysis which is necessary to increase the periodicity of nucleosomes from approximately 150 to approximately 185 bp, not only inhibits H1 and H3 phosphorylation but facilitates their dephosphorylation.

Adenosine Triphosphate↗
PubMed1991

Nosocomial infection rates in adult and pediatric intensive care units in the United States. National Nosocomial Infections Surveillance System.

To determine which intensive care unit (ICU) infection rate may be best for interhospital and intrahospital comparisons and to assess the influence of invasive devices and type of ICU on infection rates, we analyzed data from the National Nosocomial Infections Surveillance System. From October 1986 to December 1990, 79 hospitals reported 2,334 hospital-months of data from 196 hospital units. The median overall infection rate was 9.2 infections per 100 patients. However, this infection rate had a strong positive correlation with average length of ICU stay (r = 0.60, p less than 0.0001). When patient-days was used in the denominator, the median overall nosocomial infection rate was 23.7 infections per 1,000 patient-days. Although there was a marked reduction in the correlation with average length of stay, this rate had a strong positive correlation with device utilization (r = 0.59, p less than 0.0001). To attempt to control for average length of stay and device utilization, we examined device-associated nosocomial infection rates. Central line-associated bloodstream infection rates, catheter-associated urinary tract infection rates, and ventilator-associated pneumonia rates varied by ICU type. The distributions of device-associated infection rates were different between some ICU types and were not different between others (coronary and medical ICUs or medical-surgical and surgical ICUs). Comparison of device-associated infection rates and overall device utilization identified hospital units with outlier infection rates or device utilization. These data show that: (1) choice of denominator is critical when calculating ICU infection rates; (2) device-associated infection rates vary by ICU type; and (3) intrahospital and interhospital comparison of ICU infection rates may best be made by comparing ICU-type specific, device-associated infection rates.

Adult↗
PubMed1991

Role of Mls-1 locus and clonal deletion of T cells in susceptibility to collagen-induced arthritis in mice.

The role of T cell-mediated and humoral immunity to type II collagen has been well documented in collagen-induced arthritis (CIA). Previous work from our laboratory has indicated that genomic deletions of TCR V beta genes may play a role in CIA resistance in mice. This indicated a selectivity of TCR usage by autoreactive T cells in CIA in mice. Certain strains of mice, although having a normal genomic V beta TCR repertoire, can show clonal deletion of peripheral T cells that bear specific V beta gene products in their TCR. These clonally deleted T cells are reactive with self-Ag such as minor lymphocyte stimulation (Mls) Ag. An Mls-congenic strain, BALB.D2.Mlsa, which differs only at the Mls-1 a locus from BALB/c (Mls-1b), was used to examine the effect of clonal deletion of Mls-1a-reactive T cells in CIA. These two strains were crossed to three CIA-susceptible strains, B10.RIII (H-2r, Mls-1b), DBA/1 (H-2q, Mls-1a), and B10.Q (H-2q, Mls-1b), and the crosses were injected with type II collagen. A significantly decreased incidence of arthritis was observed in the (BALB.D2.Mlsa x B10.Q)F1 hybrids, compared with (BALB/c x B10.Q)F1 hybrids, upon immunization with chick type II collagen. The BALB.D2.Mlsa cross mice also had significantly lower levels of antimouse collagen antibodies. Flow cytometric analysis confirmed the clonal deletion of Mls-1a-reactive V beta 8.1, V beta 6, V beta 7, and V beta 9 subsets in the (BALB.D2.Mlsa x B10.Q)F1 hybrids. The study of H-2q/d mice in (BALB.D2.Mlsa x B10.Q) x B10.Q back-crosses demonstrated a significant correlation between CIA resistance and Mls-1a locus. On the other hand, B10.RIII crosses showed only a modest decrease in CIA incidence in the presence of Mls-1a. As expected, all the DBA/1 crosses had an equal incidence of CIA, which was somewhat less than that seen in DBA/1 mice themselves. These studies point out that the Mls-1a locus could play a role in decreasing CIA incidence by clonal deletion of T cells bearing specific V beta TCR, which may be involved in the pathogenesis of CIA. The influence of the clonal deletion of T cells on CIA, and hence the usage of specific V beta TCR by autoreactive anti-type II collagen T cells, however, depends not only on the source of the type II collagen and the MHC class II molecules involved but also on other background genes in mice.

Animals↗
PubMed1991

Purification and properties of an esterase from human breast cyst fluid.

Levels of estradiol 17 beta-ester hydrolytic activity in the breast cyst fluid (BCF) from 25 different women with fibrocystic disease of the breast were found to vary over a wide range (0-2.4 nmol/min/mg protein for estradiol acetate). On the basis of electrophoretic mobility on agarose gels, the activity from different individuals appeared to be identical. The esterase activity from a single BCF sample was purified to near homogeneity by differential ammonium sulfate precipitation, ion-exchange, and hydrophobic interaction chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, after the final purification step, showed two bands with molecular weights of approximately 22,000 and 23,000, neither of which was immunoreactive with a rabbit antibody raised to a crude esterase-free BCF preparation. Esterase activity could be demonstrated after extraction and renaturation of the protein eluted from the Mr 22,000 band. Resolution of the gel, however, was not good enough to rule out the presence of esterase activity in the Mr 23,000 protein. High performance liquid chromatography gel exclusion chromatography indicated a molecular weight of 90,000-95,000 for the esterase activity in crude BCF and approximately 225,000 for the purified activity, suggesting the native protein to be a tetramer which aggregated during purification. Although the natural substrate of the BCF esterase is unknown, the enzyme is able to cleave a variety of esters including acetate, valerate, and stearate esters of estradiol and p-nitrophenyl hexanoate. It is completely inhibited by diisopropylflurophosphate and diethylnitrophenyl phosphate and partially inhibited by NaF and ebelactone. The substrate and inhibitor profile of the enzyme indicates that it is a "B"-type carboxylesterase and not a protease. A comparison of the properties of the BCF esterase with those of esterases from the formed elements of the blood or from plasma suggests that the BCF esterase is not of blood origin and is probably derived from the cyst itself. Physiologically inactive lipoidal estrogens have been shown to be present in many human body fluids and tissues and it is possible that these esters serve as storage forms of the active hormone in hormonally sensitive tissues where the free steroid could be regenerated by hydrolysis.

Anti-Bacterial Agents↗
PubMed1991

National nosocomial infections surveillance system (NNIS): description of surveillance methods.

The National Nosocomial Infections Surveillance System (NNIS) is an ongoing collaborative surveillance system sponsored by the Centers for Disease Control (CDC) to obtain national data on nosocomial infections. The CDC uses the data that are reported voluntarily by participating hospitals to estimate the magnitude of the nosocomial infection problem in the United States and to monitor trends in infections and risk factors. Hospitals collect data by prospectively monitoring specific groups of patients for infections with the use of protocols called surveillance components. The surveillance components used by the NNIS are hospitalwide, intensive care unit, high-risk nursery, and surgical patient. Detailed information including demographic characteristics, infections and related risk factors, pathogens and their antimicrobial susceptibilities, and outcome, is collected on each infected patient. Data on risk factors in the population of patients being monitored are also collected; these permit the calculation of risk-specific rates. An infection risk index, which includes the traditional wound class, is being evaluated as a predictor of the likelihood that an infection will develop after an operation. A major goal of the NNIS is to use surveillance data to develop and evaluate strategies to prevent and control nosocomial infections. The data collected with the use of the surveillance components permit the calculation of risk-specific infection rates, which can be used by individual hospitals as well as national health-care planners to set priorities for their infection control programs and to evaluate the effectiveness of their efforts. The NNIS will continue to evolve in finding more effective and efficient ways to assess the influence of patient risk and changes in the financing of health care on the infection rate.

Centers for Disease Control and Prevention, U.S.↗
PubMed1991

Functionalization of hydroxy compounds with nitrilotriacetic acid for technetium-99m chelation: excretory properties of the radiolabelled chelates.

Substituted monoanilides of nitrilotriacetic acid (NTA) have gained much popularity in recent years as an important class of ligands for technetium-99m (99mTc) radiopharmaceutical preparations used in liver imaging and function studies. We were interested in investigating the properties of the corresponding ester analogues of this important class of ligands and for this study cyclohexanol was selected as a hydroxy component, which on condensation with nitrilotriacetic acid in the presence of acetic anhydride, furnished the monoester, N-cyclohexyloxycarbonylmethyl iminodiacetic acid 4 and the corresponding diester 5. Phenol on similar condensation produced mainly the diester, N,N-di(phenyloxycarbonylmethyl) aminoacetic acid 2, with traces of the corresponding monoester 7. A reinvestigation of the well known condensation reaction of aniline with nitrilotriacetic acid revealed that in addition to the reported monoanilide, N-phenylcarbamoylmethyl imino diacetic acid 3, the corresponding dianilide 6 was also produced in appreciable amount. The ester ligands 2, 4, 5 after 99mTc chelation exhibited good in vitro and in vivo stabilities. The biodistribution characteristics of these radiolabelled esters and amides were very similar showing thereby that esterification with NTA could be an effective method for converting alcohols to 99mTc-radiopharmaceuticals without generating any unusual properties because of the ester linkage. Residual radiopharmaceutical concentration after i.v. administration of these amide and ester 99mTc chelates at 30 min in blood, urine, liver, kidney and intestine were correlated with their lipophilicities and during this correlation it was observed that in addition to lipophilicity the anionic strength of these chelates is also an important determinant in governing their biodistribution. The ester ligand 4 after 99mTc chelation showed ultrafast hepatobiliary kinetics and was therefore compared in a rabbit model with a standard hepatobiliary radiopharmaceutical 99mTc-N-(p-butylphenylcarbamoyl methyl) iminodiacetic acid (99mTc-BIDA) by gamma-camera scintigraphy to investigate the potential of the former for clinical studies.

Animals↗
PubMed1991

Quantitative structure-activity relationship analysis of combretastatins: a class of novel antimitotic agents.

Combretastatins and their synthetic analogues, having structural features resembling that of colchicine, also have similar modes of action. In this report we have correlated the cytotoxicity of combretastatins against the murine leukemic cell line L1210 with physicochemical parameters such as the summation of the Hansch-Fujita pi constant, which was used as an index of lipophilicity of the substituent groups on ring A (sigma pi a) and ring B (sigma pi b), the vector summation of the group dipole moments of ring A (sigma mu a) and ring B (sigma mu b), the nature of the linker chain between ring A and ring B (Bt-L), indicator parameters (NOH)a and (NOH)b, which represent the number of hydroxyl groups on ring A and ring B, respectively, and the summation of pi values of the substituents on the linker (sigma pi L). Cytotoxicity correlated well with (sigma pi b), (NOH)a, (Bt-L), and (sigma mu b), and the dependency on (sigma pi b) was found to be parabolic.

Animals↗