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Biomedical subjects

J Basu

Publications and source records attributed to J Basu.

At least 55 records · Page 3Linked to original sources
PubMed1994

Lipid-soluble antioxidants: beta-carotene and alpha-tocopherol levels in breast and gynecologic cancers.

Free radical-induced damage is etiologically implicated in many chronic diseases including cancer. Epidemiologic data suggest an association between increased dietary intake of nutrients that are high in antioxidant vitamins and protection against the incidence of some human cancers. The purpose of this study was (a) to determine whether specific tissue antioxidants (beta-carotene and alpha-tocopherol) and any differences in their levels were measurable in randomly selected human breast and gynecologic malignant neoplasms and nonneoplastic tissue samples obtained from the same patient and (b) to establish normal ranges of these two antioxidant levels in human female reproductive tract tissues. Tissue samples were excised immediately from surgical specimens and released by staff pathologists from a spectrum of human female cancers. Neoplastic and adjacent nonneoplastic tissues samples were obtained from the same patient. Normal reproductive tract tissue samples were obtained from women undergoing hysterectomy for benign gynecologic conditions. Breast carcinoma and adjacent nonmalignant tissue specimens were obtained from women undergoing mastectomy. The concentrations of beta-carotene and alpha-tocopherol were measured by high-pressure liquid chromatography. In the same patient, beta-carotene levels were significantly lower in the cervical (P < 0.01) and endometrial (P < 0.005) carcinoma tissues than the levels detectable in adjacent nonneoplastic sites. In contrast, beta-carotene levels were higher in the ovarian (P < 0.05), breast (P < 0.005), and vulva (P < 0.05) carcinoma tissues. The alpha-tocopherol concentrations were significantly higher in the cancer tissues of cervix (P < 0.01) and endometrium (P < 0.001) than those in adjacent noninvolved tissue sites. The tissue concentrations of alpha-tocopherol in malignant and adjacent normal sites in breast, ovary, and vulva were comparable. For the first time, the ranges for beta-carotene and alpha-tocopherol levels in the normal female reproductive tract tissues were also established. The present findings of contrasting tissue levels of the antioxidants (beta-carotene and alpha-tocopherol) in breast, cervix, endometrium, ovary, and vulva cancers and in nonneoplastic tissues of the same patient suggest an organ-specific and heterogenous distribution. These antioxidants appear to be essential nutritional requirements of the human female reproductive tract and breast and are implicated in the pathophysiology and carcinogenesis of these human organs. The findings require further study of the role of these antioxidant nutrients in epithelial cell proliferation, maturation, and differentiation.

Antioxidants↗
PubMed1994

Preeclampsia and antioxidant nutrients: decreased plasma levels of reduced ascorbic acid, alpha-tocopherol, and beta-carotene in women with preeclampsia.

OBJECTIVE: Our purpose was to investigate the plasma levels of three potent antioxidant nutrients in women with preeclampsia. STUDY DESIGN: Fasting venous blood samples were collected from 30 women with preeclampsia and from 44 women with uncomplicated pregnancies. The criteria for recruitment included age 15 to 35 years, gestational age 28 to 42 weeks, singleton pregnancy, intact membranes, absence of labor contractions, and absence of any other medical complication concurrent with preeclampsia. Reduced ascorbic acid, alpha-tocopherol, and beta-carotene levels were assayed with high-pressure liquid chromatography. RESULTS: Plasma levels of reduced ascorbic acid were significantly decreased in patients with mild and severe preeclampsia (p < 0.01). Plasma alpha-tocopherol and beta-carotene levels were significantly decreased only in severe preeclampsia compared with controls (p < 0.05 and p < 0.05, respectively). CONCLUSION: In patients with preeclampsia antioxidant nutrients may be utilized to a greater extent to counteract free radical-mediated cell disturbances, resulting in a reduction in antioxidant plasma levels. Water-soluble antioxidant nutrients may initially be consumed, followed by lipid-soluble antioxidants.

Adolescent↗
PubMed1994

Characterization of a 38 kDa penicillin-binding protein and its possible involvement in maintaining stationary-phase cells of Shigella dysenteriae.

This paper reports the first attempt to characterize the penicillin-binding proteins (PBPs) of Shigella dysenteriae, an important human pathogen. The PBP pattern of the membranes of S. dysenteriae closely resembles that of Escherichia coli membranes. A 38 kDa PBP which is an important target for the penem SCH34343, the cephamycin cefoxitin and the oxacephem moxalactam, has been purified. This PBP is immunologically related to a PBP of similar molecular mass in E. coli and is present at high levels in stationary-phase cells of S. dysenteriae.

Amino Acid Sequence↗
PubMed1994

Decreased beta-carotene levels in exfoliated vaginal epithelial cells in women with vaginal candidiasis.

PROBLEM: Women are more susceptible to vaginal candidiasis when the host immune response is suppressed. The antioxidant nutrient beta-carotene is postulated to possess immunoenhancing properties. The purpose of this study was to investigate beta-carotene concentrations in exfoliated vaginal epithelial (EVE) cells in women with vaginal candidiasis. METHODS: Beta-carotene levels in EVE cells, collected by a saline lavage technique from 22 women with vaginal candidiasis and 20 normal controls, were analyzed. The diagnosis of vaginal candidiasis was established by the presence of pruritus, white cheesy vaginal discharge, and a positive potassium hydroxide preparation. Beta-carotene levels were assayed using high pressure liquid chromatography. RESULTS: Vaginal cell concentrations of beta-carotene were significantly decreased in women with vaginal candidiasis (P < 0.001). CONCLUSIONS: Decreased beta-carotene levels, and possibly other antioxidants, may alter the local immune response resulting in disturbances in the vaginal flora, overgrowth of candida, and the development of vaginal candidiasis.

Adolescent↗
PubMed1994

An analysis of market shares of Maryland hospitals in their service areas.

The study analyzes market shares (or competitiveness) of Maryland hospitals based on a service area definition of hospitals used for acute care planning in Maryland. The study uses this service area definition to analyze market shares of Maryland hospitals, to test them under alternative hypotheses and, finally, to examine the impact of several key variables. The study finds that proximity of other hospitals, and hospital's occupied bed size, have statistically significant impacts on market shares of hospitals irrespective of hospital location in a metropolitan or rural area.

Bed Occupancy↗
PubMed1993

Hospital service areas and Medicaid access in Maryland.

The study defines a service area (rather than a market area) of an individual hospital. Based on patient origin data, algorithms have been developed to select zip codes on the basis of their contributions to a hospital's discharges, and their ability to fulfill a contiguity principle along with a dependence criterion. The service area concept is also used to evaluate the performances of hospitals in terms of the access to care for Medicaid patients. The analysis shows that the hospital's performance in serving Medicaid patients does not significantly depend on its location, nor does it matter whether it is the only hospital in its jurisdiction.

Algorithms↗
PubMed1993

Alterations in erythrocyte glutathione metabolism associated with cervical dysplasias and carcinoma in situ.

The study was designed to test the hypothesis whether cervical dysplasias of the more severe grades are associated with elevated erythrocyte glutathione levels. Subjects were women who obtained Pap tests and were subsequently found (1) not to have any cervical lesions or (2) to have colposcopically visualized, biopsy-confirmed cervical abnormalities histopathologically diagnosed as mild, moderate, severe dysplasias, or carcinoma in situ (CIS). The erythrocyte levels of reduced glutathione (GSH), oxidized glutathione (GSSG), glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PD), and 6-phosphogluconate dehydrogenase (6PGD) were analyzed from coded peripheral venous blood samples. GSH and GR concentrations increased with increasing severity of dysplasia. Exploratory data analysis and multiple pairwise comparisons suggested comparable levels of the glutathione-related variables between these histopathological pairs: (1) mild and moderate dysplasias or (2) severe dysplasia and CIS. We suggest that the changes in erythrocyte glutathione-related indices in conjunction with histopathological diagnosis may have the potential to distinguish between low- and high-grade cervical dysplastic lesions.

Carcinoma in Situ↗
PubMed1992

Fatty acylation of a 55 kDa membrane protein of human erythrocytes.

The major palmitoylated human erythrocyte membrane protein has an M(r) of 55,000. It is distinct from the glucose transporter and is not derived from band 3 or ankyrin. It resists salt extraction suggesting a high affinity for the membrane. Pulse chase experiments demonstrate that palmitoylation is a dynamic process, and it may therefore have regulatory significance in membrane protein-protein or protein-lipid interaction. Slower dynamics of palmitoylation in erythrocytes from patients suffering from chronic myelogenous leukemia, which are less stable than normal erythrocytes, strengthen this view.

Acylation↗
PubMed1992

Purification of a phosphatidylinositol/phosphatidylcholine transfer protein from Neurospora crassa.

This paper reports, for the first time, the purification of a phospholipid transfer protein (PLTP) from a fungus, Neurospora crassa. The protein was purified from the post-microsomal supernatant of N. crassa by successive chromatography on DEAE-cellulose, Sephadex-G75 and PBE 94 (pH 4-7). The purified protein (M(r) 38,000) was found to transfer phosphatidylinositol preferentially over phosphatidylcholine, like the PLTP from the yeast, Saccharomyces cerevisiae. PC transfer was completely inhibited by inactivation of free amino groups or tryptophan residues. Surprisingly, the protein did not cross-react with antibodies against the bovine brain PITP. The cellular content of the protein was maximal during the logarithmic phase of growth. However, no direct correlation between the content of the protein and PC transfer activity could be demonstrated.

Androgen-Binding Protein↗
PubMed1992

Beta-carotene levels in exfoliated cervicovaginal epithelial cells in cervical intraepithelial neoplasia and cervical cancer.

OBJECTIVE: The purpose of this study was to measure beta-carotene levels in exfoliated epithelial cervicovaginal cells collected by a lavage technique in normal women and patients with histopathologically diagnosed cervical intraepithelial neoplasia and cervical cancer. STUDY DESIGN: In a cross-sectional sampling of women (n = 105), cervicovaginal cells and plasma beta-carotene levels were assayed with high-pressure liquid chromatography. In addition, beta-carotene levels were measured in exfoliated epithelial samples of cervicovaginal cells obtained from women (n = 24) enrolled in an ongoing oral beta-carotene supplementation clinical trial. RESULTS: Cervicovaginal cells and plasma beta-carotene levels were found to be significantly decreased in women with cervical intraepithelial neoplasia and cervical cancer as compared with controls (p < 0.0001, analysis of variance). Retinol levels in cervicovaginal cells were undetectable. The beta-carotene levels in cervicovaginal cells were markedly increased in the majority of patients (79%) after oral supplementation as compared with baseline levels in women enrolled in the beta-carotene clinical trial. CONCLUSION: The study demonstrates that changes of in situ cellular beta-carotene concentrations are measurable in samples of exfoliated epithelial cells obtained by a noninvasive saline lavage harvesting technique. The current findings further support our previous hypothesis that beta-carotene deficiency may have an etiologic role in the pathogenesis of cervical intraepithelial neoplasia and/or cervical cancer.

Adolescent↗
PubMed1992

Factors influencing the exfoliation of cervicovaginal epithelial cells.

OBJECTIVE: Our objective was to investigate the association of smoking and exfoliation of cervicovaginal epithelial cells while controlling for other factors that may potentially influence cell exfoliation (e.g., presence of cervical intraepithelial neoplasia or koilocytes, the use of oral contraceptives, age, and the phase of the menstrual cycle). STUDY DESIGN: Cervicovaginal lavage specimens and epidemiologic questionnaires were obtained with informed consent from 190 women. The cervicovaginal lavage samples were processed to separate other contaminants. The number of squamous epithelial cells counted was expressed as cells per milliliter of lavage. RESULTS: Multiple linear regression analysis revealed that the number of exfoliated epithelial cells was significantly higher in smokers (p < 0.01) and also in women with cervical intraepithelial neoplasia (p < 0.05). The other studied variables had no detectable effect. CONCLUSION: The findings suggest that smoking or the presence of cervical intraepithelial neoplasia may induce an acceleration in the exfoliation of cervicovaginal epithelial cells. This may alter cell maturation and may be a factor in the oncogenic process.

Adolescent↗
PubMed1992

Purification and partial characterization of a penicillin-binding protein from Mycobacterium smegmatis.

Penicillin-binding proteins (PBPs), although characterized from several organisms, have so far not been studied in mycobacteria. The present study is the first characterization of a PBP from Mycobacterium smegmatis. The PBP was purified by solubilization of the membranes with Triton X-100 and successive chromatography of the solubilized proteins on ampicillin-linked CH Sepharose 4B and DE-52. The purified PBP (M(r), 49,500) catalyzed a model transpeptidase reaction with the tripeptide acetyl2-L-Lys-D-Ala-D-Ala as the substrate and Gly-Gly as the acceptor. The transpeptidase activity was inhibited by 50% at a benzylpenicillin concentration of 1.8 x 10(-7) M, which was similar to the concentration (1.1 x 10(-7) M) of benzylpenicillin required to saturate to 50% this PBP. Of several antibiotics tested, the concentration of antibiotic required to inhibit [35S]penicillin binding by 90% was found to be the lowest for cefoxitin and Sch 34343.

Amino Acid Sequence↗
PubMed1992

Endogenous estradiol and progesterone concentrations in smokers on oral contraceptives.

The simultaneous effects of cigarette smoking and oral contraceptives on serum estradiol and progesterone levels were investigated in 114 premenopausal women. Serum 17 beta-estradiol and progesterone levels were measured by radioimmunoassay. In smokers, estradiol and progesterone levels were significantly lower (p less than 0.025). In smokers using oral contraceptives, estradiol and progesterone levels were the lowest (p less than 0.001 and p less than 0.01, respectively). The findings suggest that smoking and oral contraceptives independently lower serum estradiol and progesterone concentrations in premenopausal women and that the effects may be additive.

Adolescent↗
PubMed1992

An analysis of trends in average length of stay in Maryland Hospitals, 1980-1988.

Nationally, the introduction of the Medicare Prospective Payment System (PPS) in 1983 caused a substantial change in average length of stay (ALOS) trends in hospitals. This resulted from an average decline in DRG-specific length of stay, partially offset by an increase in the relative contributions of DRGs with longer length of stay. The study finds that the interaction of these two opposing forces was present in Maryland as well as in the United States during the early and mid-1980's although Maryland was not under PPS. The analysis also indicates that these post-PPS ALOS trends tapered off gradually during 1985-1988, although the trends still continued to show the same pattern of movement.

Data Collection↗
PubMed1991

Altered erythrocyte protein kinase C activity and membrane protein phosphorylation in chronic myelogenous leukemia.

The membrane protein kinase C (PKC) content was found to be higher in erythrocytes form patients suffering from chronic myelogenous leukemia (CML) compared to normal erythrocytes. PKC activity was also higher in the cytosol and after translocation to the membrane, as assessed by histone phosphorylation. The increased PKC activity in CML erythrocytes was associated with abnormal phosphorylation of protein 4.1. Since phosphorylation-dephosphorylation mechanisms are likely candidates for controlling membrane protein associations, the altered PKC activity may be one of the factors responsible for altered thermal sensitivity and mechanical stability of CML erythrocytes.

Cytoskeletal Proteins↗