Biomedical subjects

S Grover

Publications and source records attributed to S Grover.

At least 73 records · Page 4Linked to original sources

PubMed1996

Production of antifungal substance by Lactococcus lactis subsp. lactis CHD-28.3.

Six of the 2100 colonies of lactic acid bacteria isolated from 4 month old Cheddar cheese and raw buffalo milk showed antifungal activity against Aspergillus flavus IARI when tested by the well agar diffusion assay on Potato Dextrose Agar containing 0.1% Triton X-100. Out of these, the most promising isolate having a broad spectrum of antifungal activity including Aspergillus flavus IARI, A. flavus NCIM 555, A. parasiticus NCIM 898 and Fusarium spp. was identified as Lactococcus lactis subsp. lactis CHD-28.3. Among the mold cultures used as indicator strains, the most sensitive towards antifungal substance produced by the test culture was A. flavus IARI. The cell-free supernatant of the test culture in Elliker's broth adjusted to pH 6.8 produced an inhibition zone of 15-19 mm against A. flavus IARI, A. flavus NCIM555 and A. parasiticus NCIM898. The isolate when grown at 30 degrees C for 48 h in Elliker's broth showed optimum antifungal activity. When the supernatant was neutralized to pH 7.0 or 7.5, there was little reduction in activity. However, after enzymatic treatment of supernatant with chymotrypsin, trypsin and pronase E, the antifungal activity disappeared which indicated the proteinaceous nature of the antifungal substance.

Antifungal Agents↗

PubMed1996

Visual acuity impairment in patients with retinitis pigmentosa.

PURPOSE: The authors evaluated visual acuity impairment in 906 patients from 742 families with either isolated or various identifiable genetic subtypes of retinitis pigmentosa (RP) to determine the severity of their visual acuity impairment. Emphasis was placed on the prevalence of total blindness and visual acuity of 20/200 or worse in this group of patients. METHODS: This cross-sectional retrospective study included all patients with RP who met certain entrance criteria and were examined by one of the authors (GAF). The authors analyzed the eye of each patient with the best-corrected visual acuity on their most recent visit. RESULTS: Seventeen patients with a sector form of RP were excluded from the authors primary analysis. In the remaining group of 889 patients, 710 (80%) had a visual acuity of better than 20/200, 648 (73%) showed a visual acuity of 20/70 or better, and 489 (55%) had a visual acuity of 20/40 or better in at least 1 eye. Seventy-five patients (8%) had visual acuity of count fingers or worse in their best eye. There was only one patient with no light perception in each eye. Patients with autosomal dominant RP, as a group, had the least severe and those with X-linked recessive RP had the most severe impairment in visual acuity. Those with autosomal recessive disease were intermediate in severity of visual impairment. CONCLUSIONS: Analysis of visual acuity in this large group of patients with RP, which genetically is representative of patients with RP seen in the United States by those who specialize in retinal disease, showed that it was rare for the patients to lose all visual acuity from the disease itself. Further, legal blindness from visual acuity loss, defined as best-corrected visual acuity that is no better than 20/200 in at least one eye, occurred in a relatively small percentage (20%) of our patient population, whereas approximately half of all patients and 42% of those older than 60 years had a visual acuity of 20/40 or better in at least one eye. The extent of impairment in visual acuity was associated with the genetic subtype of the disease.

Adolescent↗

PubMed1996

Frequency of photographically apparent optic disc and parapapillary nerve fiber layer drusen in Usher syndrome.

PURPOSE AND DESIGN: Using a retrospective case series, the authors determine the frequency and clinical features of optic disc and parapapillary nerve fiber layer drusen in type I and type II Usher syndrome (congenital deafness and retinitis pigmentosa). METHODS: Color fundus photographs available on 43 patients with type I and 108 patients with type II Usher syndrome were analyzed for the presence of optic disc or parapapillary nerve fiber layer drusen. RESULTS: Optic disc and/or parapapillary nerve fiber layer drusen were observed in 15 (35%) of 43 patients with type I Usher syndrome and 9 (8%) of 108 patients with type II Usher syndrome for whom color photographs were available. Bilateral drusen were observed in 11 patients (73%) with type I and 3 patients (33%) with type II Usher syndrome. In 3 (20%) of the 15 patients with type I and in 5 (56%) of the 9 patients with type II, only an isolated druse was seen. Six of the 15 patients with type I Usher syndrome showed parapapillary nerve fiber layer drusen, whereas the drusen were within the optic disc in all 9 patients with type II. CONCLUSIONS: Drusen of the optic disc and parapapillary nerve fiber layer tended to occur more frequently in type I than type II Usher patients and also were more often bilateral and multiple, with a tendency to occur in the parapapillary region and within the optic disc.

Adolescent↗

PubMed1996

Short-term IgM and IgG antibody responses to hepatitis E virus infection.

53 adult patients with acute hepatitis caused by hepatitis E virus were identified by the presence of IgM antibody to hepatitis E virus, and followed for 12 months to evaluate the kinetics of anti-HEV antibodies. All but 1 female Kuwaiti patient were expatriate workers from the Indian subcontinent, temporarily working in Kuwait. Follow-up samples obtained at 1, 3, 6 and 12 months were evaluated for IgM and IgG antibodies to hepatitis E virus. IgM-class antibodies to hepatitis E virus were detectable in 12/27 (44%) patients at 1 months, in 0/26 at 3 months, in 0/8 at 6 months and 0/6 at 12 months. IgG antibodies to hepatitis E virus were detectable in 46/47 (98%) at onset, 26/27 (96%) at 1 month, in 26/29 (90%) at 3 months, 16/16 (100%) at 6 months and 8/8 (100%) at 12 months of follow-up. This study suggests that IgM antibodies to hepatitis E virus decline rapidly after an acute infection but IgG antibodies to hepatitis E virus persists for at least 1 year in many patients.

Acute Disease↗

PubMed1995

Complete sequence of the gene encoding a chorionic gonadotropin-like protein from Xanthomonas maltophilia.

Our laboratory has previously reported that: (i) Xanthomonas maltophilia (Xm) produces a protein which has immunological resemblance to the beta-subunit of human chorionic gonadotropin (hCG) and (ii) possesses a high-affinity receptor which binds holo hCG, and the endogenous ligand, Xm chorionic gonadotropin (xCG), but does not bind human luteinizing hormone (hLH). We have also previously published a 492-bp partial nucleotide sequence of the gene (xcg) coding for xCG. We report herein the entire xcg sequence of 1362 bp, which codes for a 48-kDa protein. This sequence confirmed the 492-bp sequence, as well as two partial amino acid (aa) sequences which we have previously reported. The sequence has a region which is homologous to aa 56-139 of the beta-subunit of hCG, and a second region homologous to the C-terminal tail of hCG. This is the first report of a prokaryotic gene homologous to the hCG beta-subunit-encoding gene.

Amino Acid Sequence↗

PubMed1995

Differential effects of paclitaxel (Taxol) analogs modified at positions C-2, C-7, and C-3' on tubulin polymerization and polymer stabilization: identification of a hyperactive paclitaxel derivative.

Our finding that an analog of paclitaxel (Taxol) modified at position C-2 (2-debenzoyl-2-(m-azidobenzoyl)paclitaxel) was substantially more active than paclitaxel in promoting tubulin assembly [Chaudhary et al. (1994) J. Am. Chem. Soc. 116, 4097-4098] led us to perform an analysis of the modulating effects of microtubule-associated proteins, GTP, and temperature on assembly and polymer stability. The analog always showed superior activity to paclitaxel in inducing polymerization where it fails to occur without drug, probably indicating a greater ability than paclitaxel to "hypernucleate" assembly. In contrast, much smaller differences in effects on polymer stability were observed. The analysis was extended to a large series of derivatives modified at positions C-2, C-7, C-10, and C-3', including docetaxel, a clinically important analog of paclitaxel. While analog stabilization of polymer was frequently observed, neither qualitative nor quantitative analysis of this property reliable predicted whether a compound would have enhanced hypernucleation activity relative to that of paclitaxel. Stabilization was often observed at substoichiometric analog concentrations, while even superstoichiometric concentrations of most compounds failed to induce extensive tubulin polymerization at low temperatures or in the absence of microtubule-associated proteins or GTP. Docetaxel was intermediate in activity between paclitaxel and 2-debenzoyl-2-(m-azidobenzoyl)paclitaxel in promoting assembly reactions. We conclude that the hypernucleation of tubulin assembly and polymer stabilization observed with paclitaxel represent two distinct properties of the drug. Our findings suggest that paclitaxel, docetaxel, and 2-debenzoyl-2-(m-azidobenzoyl)paclitaxel are able to interact with progressively smaller assemblages of tubulin at low temperatures or in the absence of microtubule-associated proteins or GTP.

Drug Stability↗

PubMed1995

Lightning and electrical injuries: neuro-ophthalmologic aspects.

Lightning and electrical injuries have widespread manifestations involving almost all organ systems of the body, including the central nervous system (CNS) and the eye. This article considers the neuro-ophthalmologic effects of lightning and electrical injury.

Animals↗

PubMed1995

Developing a collaborative community partnership program in medical asepsis with tattoo studios.

The possibility of transmission of infectious agents during tattooing has become a legitimate issue of concern for health care providers. A collaborative educational program was developed by a county health department, College of Nursing, and tattoo artists to address issues of medical asepsis with the goal of producing a mechanism for certification of tattoo studios. The group's effort was enhanced by recognizing each other's value systems and by the mutual need for a successful program. A framework for developing, implementing, and evaluating community partnerships was addressed. This program demonstrated that community health nurses can play an instrumental role in collaborating with both health care providers and personal-service workers to minimize transmission of infectious agents during cosmetic procedures.

Asepsis↗

PubMed1995

Cytodiagnosis of lower respiratory tract lesions by transthoracic needle aspiration.

A comprehensive prospective and retrospective study of 130 cases was carried out to evaluate the safety, adequacy and diagnostic accuracy of Transthoracic Needle Aspiration (TTNA) in various pulmonary lesions. Using both guided and unguided TTNA diagnostic material was procured in 86.15% cases. Rotex II, Chiba, lumber puncture and ordinary needles were used depending upon the type of lesion. Overall diagnostic accuracy of the procedure was 79.46 percent. Complication after the procedure were transient and self limiting. Haemoptysis was noted in 3.84 percent cases and pneumothorax in a single case. Thus TTNA can be safely included in the investigative protocol of lung lesions.

Adolescent↗

PubMed1994

Gynaecology.

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Estrogen Replacement Therapy↗

PubMed1994

Obstetrics.

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Female↗

PubMed1994

The magnesium-GTP interaction in microtubule assembly.

Microtubule-associated-protein-dependent assembly of tubulin with GDP in the exchangeable site (tubulin-GDP) can occur with minimal free Mg2+ (< 3 microM). This reaction is totally inhibited by EDTA and by GTP concentrations over 2 mM and stimulated by MgCl2. Quantitative aspects of this stimulation are affected by both the Mg2+ and GTP concentrations but no relationship exists between reaction rates and relative amounts of different magnesium and GTP species. GTP binding to tubulin-GDP, while maximally stimulated 2-3-fold by exogenous MgCl2, was inhibited less than 50% by EDTA, and the amount of GTP bound increased as its concentration rose to levels that inhibited polymerization. Studies on the binding of Mg2+ to tubulin-GDP in the presence and absence of GTP showed that the increase in the amount of tubulin-associated Mg2+ was substoichiometric to the amount of GTP bound (maximum stoichiometry of additional Mg2+ to GTP bound, 0.7). Upon polymerization the increased Mg2+ content of tubulin was reduced, indicating its loss during GTP hydrolysis. Mg2+ thus plays a critical role in assembly distinct from its enhancement of GTP binding to the exchangeable site. If magnesium is present in trace amounts, this role must either be catalytic during polymerization or limited to nucleation.

Animals↗

PubMed1994

Acute sporadic hepatitis E in Kuwait.

Fifty-seven adult patients with acute hepatitis and 34 comparison patients without liver disease were evaluated using a newly developed Western blot assay for IgM antibody to hepatitis E virus. The mean age of patients with hepatitis was 32 years (range, 18-55 years); 88% were male. Among patients with acute hepatitis, hepatitis A (anti-HAV IgM positive) was diagnosed in two (4%), hepatitis B (anti-HBc IgM positive) in three (5%), and hepatitis E (anti-HEV IgM positive) in 34 (60%). One hepatitis patient had CMV IgM, another had EBV IgM, and 16 others (28%) were negative for all serologic markers of acute viral hepatitis. No patient with acute hepatitis A or B and none of the comparison patients without acute hepatitis had anti-HEV IgM. All but one case of acute hepatitis E were found among expatriates of Asian origin, and acute hepatitis E was associated significantly with recent travel to the Indian subcontinent. These data suggest that acute hepatitis E is common among foreign workers in Kuwait but that little HEV transmission is occurring directly in Kuwait.

Acute Disease↗

PubMed1994

Unexplained elevated maternal serum alpha-fetoprotein levels and perinatal outcome in an urban clinic population.

OBJECTIVE: Our purpose was to determine whether obstetric patients with unexplained elevated maternal serum alpha-fetoprotein levels from an indigent clinic population are at increased risk for adverse perinatal outcome compared with similar patients with normal values. STUDY DESIGN: Perinatal outcomes from inner-city obstetric patients with unexplained elevated maternal serum alpha-fetoprotein levels (> 2.0 multiples of the median) were compared with patients from the same clinic with normal values. The frequency of adverse outcomes in the two groups was subjected to chi 2 analysis. RESULTS: Adverse perinatal outcomes occurred in 33 of 57 (58%) of the subjects with unexplained elevated maternal serum alpha-fetoprotein levels compared with 163 of 719 (23%) patients with normal values (p < 0.001). Statistically significant differences were observed for abruptio placentae (p < 0.025), intrauterine growth retardation (p < 0.025), stillbirth at > 20 weeks (p < 0.001), and pregnancy-induced hypertension (p < 0.01). Differences in the frequencies of preterm premature rupture of membranes, preterm delivery, pregnancy loss < 20 weeks, and congenital malformations were not statistically significant. CONCLUSION: In contrast to a previous report, we found that unexplained elevated maternal serum alpha-fetoprotein levels confer an increased risk of adverse perinatal outcome in an urban clinic population over and above the already increased risk related to socioeconomic status.

Abruptio Placentae↗

PubMed1994

Uveitogenic T lymphocytes in the rat: pathogenicity vs. lymphokine production, adhesion molecules and surface antigen expression.

A possible correlation between the pathogenicity of autoimmune T cells and their lymphokine production, expression of functional adhesion molecules and expression of some surface antigens was examined. We used four retinal antigen-specific Lewis rat T cell lines and sublines: one specific to the major pathogenic epitope of the human retinal soluble antigen (S-Ag; residues 337-356), and three specific to the major pathogenic epitope of the bovine interphotoreceptor retinoid binding protein (IRBP; residues 1177-1191). The lines have different degrees of uveitogenicity, from highly pathogenic to nonpathogenic. All four T cell lines produced roughly equivalent amounts of interferon-gamma, lymphotoxin/tumor necrosis factor (TNF alpha/beta), interleukin-3, interleukin-6 and transforming growth factor-beta. Interleukin-4 activity could not be detected. The lines also expressed similar levels of functional adhesion molecules, as measured by binding to cultured rat aorta endothelial cells. The nonpathogenic subline, however, was the lowest responder to antigenic stimulation with respect to proliferation and interleukin-2 production. Examination of cell surface antigens showed that in contrast to the other lines, the majority of cells in the nonpathogenic subline lacked detectable expression of CD4. No difference was found in the level of expression of the IL-2 receptor and T cell antigen receptor among the four lines. Because CD4 is the restricting element in these lines, reduced CD4 expression in the nonpathogenic subline may at least partially explain its poor response in vitro to antigenic stimulation. All three attributes could be connected to lack of pathogenicity of this line in vivo. These results support the contention that class II-restricted recognition of autoantigen within the neuroretina by uveitogenic T lymphocytes must occur as an initial step in the pathogenesis of EAU. A defect in this step will preclude pathogenesis regardless of some other functional attributes possessed by effector T cells, such as production of inflammatory lymphokines and expression of adhesion molecules.

Animals↗

PubMed1994

The presence of a human chorionic gonadotropin-like protein and its binding site in Saccharomyces cerevisiae.

In this study, we characterize from Saccharomyces cerevisiae: 1) a protein that has immunological similarities to human chorionic gonadotropin (hCG), and 2) a binding site for this hCG-like protein which also binds hCG and human luteinizing hormone (hLH). Saccharomyces cerevisiae chorionic gonadotropin-like protein (ScCGLP) was purified in several steps. This protein when analyzed by SDS-PAGE, under nondenaturing conditions, produced two bands, one at 110-kDa, and another at 57.5-kDa. Under denaturing conditions, only the 57.5-kDa band appeared. This 57.5-kDa band also reacted in a Western blot, using a polyclonal antibody directed against hCG. Purified ScCGLP reacted in the following hCG immunoassays: 1) polyclonal rabbit anti-hCG equilibrium assay, 2) carboxyl-tail hCG equilibrium assay, 3) two equilibrium assays using monoclonal antibodies, and 4) free alpha-chain subunit equilibrium assay using a monoclonal antibody. Characterization of hCG/hLH binding sites in Saccharomyces cerevisiae was performed, and the ability of the ScCGLP to displace I125-hCG was also shown. Human CG and hLH were able to compete for I125-hCG binding to Saccharomyces cerevisiae blastospores (Kds of approximately 10(-8) M), while ScCGLP competed with higher affinity (Kd = 9.41 x 10(-10) M). The hCG-like immunoactivity was also present in Saccharomyces growth media, as well as in all brands of commercial beer studied.

Binding Sites↗

PubMed1993

Patterns of inheritance of ovarian cancer. An analysis from an ovarian cancer screening program.

BACKGROUND: A variety of inheritance patterns for familial ovarian cancer have been proposed including an autosomal dominant inheritance, a breast-ovary cancer syndrome and Lynch Cancer Family Syndrome (involving breast, bowel, ovary, and endometrial cancers). METHODS: Women participating in an ovarian cancer screening study completed a questionnaire concerning their family history of ovarian and other malignancies (in particular breast, bowel, and endometrial cancer). Confirmation of the diagnosis was sought when there was uncertainty. RESULTS: Two hundred forty women with a first-degree relative with ovarian cancer participated in the study. Nine percent of these women (representing 13 families) gave a definite history of two or more affected first-degree relatives. Two families had a pedigree consistent with an autosomal dominant inheritance. A breast-ovary cancer family and a Lynch cancer family syndrome were suspected in one family each, although 34% of all women gave a history of at least one other first-degree relative with either breast, bowel, or endometrial cancer. CONCLUSIONS: Only a small number of women with a family history of ovarian cancer fit into the recognized hereditary patterns. Difficulty in recognizing the inheritance patterns and the lack of definitive genetic markers poses problems in providing adequate counseling regarding screening and prophylactic oophorectomy.

Adenocarcinoma↗

PubMed1993

A bacterial protein has homology with human chorionic gonadotropin (hCG).

Studies from our laboratory have demonstrated the presence of a 48.5 kD cell wall protein in the bacterium, Xanthomonas maltophilia, which immunologically resembles the beta subunit of human chorionic gonadotropin. Primers were designed from the amino acid sequences of enzymatically cleaved peptide fragments of this protein. These primers were used to obtain PCR amplified products, which were subsequently cloned in a PCR11TA cloning vector, and a 492 base pair nucleotide sequence was obtained with a 164 amino acid open reading frame. When this nucleotide sequence was aligned with exon 2 of genes 5 and 6 of the beta hCG gene, a 53% homology was observed. The translated protein sequence had a 35% homology with hCG and a 25% homology with human luteinizing hormone.

Amino Acid Sequence↗