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Biomedical subjects

S Grover

Publications and source records attributed to S Grover.

At least 37 records · Page 2Linked to original sources
PubMed1998

Intraocular light scatter in patients with choroideremia.

OBJECTIVE: This study aimed to evaluate the extent of intraocular light scatter in patients with choroideremia. DESIGN: Prospective case-control study. PARTICIPANTS: Twelve male patients with choroideremia who had predominantly minimal or no posterior subcapsular cataract (PSC) lens opacities and visual acuities of 20/40 or better and 30 age-similar control subjects with normal vision and no lens opacities were studied. INTERVENTION: Intraocular light scatter was measured using a van den Berg Straylightmeter. MAIN OUTCOME MEASURES: Visual acuities, letter contrast sensitivities, Goldmann visual fields using a II4e target, and straylight parameters were obtained for each patient. Lenses were assessed by slit-lamp biomicroscopy to determine whether there were PSC opacities. The degree of retinal pigment epithelial and choroidal degenerative changes was evaluated from color fundus photographs. RESULTS: Three of the patients with choroideremia who had clinically apparent PSC lens opacities showed an increase in intraocular light scatter. More notable was the fact that seven of the remaining nine patients who did not have any clinically apparent changes in the lens also had a considerable increase in the intraocular light scatter as compared to the control subjects. The relative elevations of the log straylight parameters of the patients with choroideremia, as compared to age-similar control subjects, were correlated significantly with their log visual field areas (r = -0.69, P < 0.05). CONCLUSIONS: Intraocular light scatter may be increased in patients with choroideremia, even in the absence of clinically observable PSC opacities. It is hypothesized that the increase in light scatter may be caused by changes in the posterior subcapsular region of the lens before the formation of frank PSC cataracts. The increased straylight could, at least in part, account for the disability glare reported by these patients.

Adult↗
PubMed1998

The moderating effect of self-esteem in reaction to voice: converging evidence from five studies.

It has been posited that high self-esteem persons (high SEs) are more confident than low self-esteem persons (low SEs) of their capability to provide meaningful input in a decision process. If this is so, then high SEs should be more influenced by their perceived level of voice, relative to low SEs. Survey data from 4 field studies showed that voice was more positively related to various dependent variables among high SEs than low SEs. In Study 5, the authors experimentally manipulated voice as well as participants' beliefs about their capability to provide meaningful input. As expected, voice had a greater impact on the reactions of participants who were led to believe that they were more capable of providing meaningful input. Theoretical implications are discussed.

Adolescent↗
PubMed1998

Legal blindness and employment in patients with juvenile-onset macular dystrophies or achromatopsia.

PURPOSE: The purpose of this study was to gain information about the employment status of legally blind patients. METHODS: Fifty-two patients with one of four juvenile-onset macular dystrophies or achromatopsia responded to questions about their employment histories and their psychological well-being. Results from the questionnaire were analyzed using z-tests for differences in proportions or t-tests for differences in means. RESULTS: Forty-eight percent of the patients reported that they were employed and 52% that they were not employed. The subgroup that was not employed had a significantly higher proportion of women than men, whereas the employed group had approximately equivalent proportions of men and women. The employed subgroup reported that their success at work was due to social support. This subgroup had significantly higher household incomes, was significantly less likely to collect disability-income benefits, had significantly higher educational levels, had significantly higher positive affect, and had significantly lower negative affect than the subgroup that was not employed. A logistic regression analysis indicated that education was the primary predictor of employment. CONCLUSION: Analysis supports the conclusion that it is beneficial for legally blind individuals to obtain an optimal level of education and receive suitable social support to facilitate their successful employment.

Adolescent↗
PubMed1998

PCR-based rapid detection of Mycobacterium tuberculosis in blood from immunocompetent patients with pulmonary tuberculosis.

A PCR test based on insertion sequence IS1081 was developed to detect Mycobacterium tuberculosis complex organisms in the peripheral blood. The method was applied to blood samples from immunocompetent individuals with localized pulmonary tuberculosis. Seven of 16 (43.75%) blood samples were found to be positive for the circulating DNA copies of M. tuberculosis complex.

DNA Primers↗
PubMed1998

Difficulty in performing everyday activities in patients with juvenile macular dystrophies: comparison with patients with retinitis pigmentosa.

AIMS: To ascertain the level of perceived difficulty experienced by patients with central vision loss due to juvenile macular dystrophies in the performance of everyday activities. A second objective was to compare their perceived difficulty with that of patients with retinitis pigmentosa (RP) with primarily peripheral vision loss. METHODS: 72 patients with Stargardt disease, cone dystrophy, or cone-rod dystrophy who had visual acuities worse than 20/40 and normal peripheral visual fields rated themselves on their difficulty in the performance of 33 activities encompassing a wide variety of everyday tasks. These findings were compared with the responses of 120 patients with typical RP or Usher syndrome type 2 who had visual acuities of 20/40 or better and peripheral visual field loss. RESULTS: The juvenile macular dystrophy group reported the greatest level of overall self perceived difficulty with activities involving central vision, and lesser and variable degrees of difficulty with items within the mobility, negotiating steps, driving, and miscellaneous categories. Consistent with these findings, there were highly significant correlations between subjects' rated performances of activities involving central vision and the clinical measures of vision, including visual acuity and size of central scotoma. There were fewer significant correlations between perceived performance of activities in the other categories and the clinical measures. In general, those activities that showed significant correlations with the clinical measures of vision for the patients with juvenile macular dystrophies also showed significant differences in the patterns of responses between the juvenile macular dystrophy group and the RP group. Those items which were not correlated with the clinical measures in the juvenile macular dystrophy group tended not to show significant differences in the response patterns between the two groups. CONCLUSION: These results provide insight into the types of perceived difficulties in performing tasks of everyday life in patients with these disorders which affect counselling of these patients.

Activities of Daily Living↗
PubMed1997

A head-to-head comparison of the cost effectiveness of HMG-CoA reductase inhibitors and fibrates in different types of primary hyperlipidemia.

The objective of this study was to compare the lifetime cost-effectiveness of HMG-CoA reductase inhibitors and fibrates for the treatment of hyperlipidemia. Estimates of lipid modification achieved due to drug therapy were based on published head-to-head comparisons of specific HMG-CoA reductase inhibitors and fibrates in randomized, double-blind studies. We used a validated coronary heart disease (CHD) prevention computer model to estimate the costs and benefits of lifelong lipid modification. The patients were middle-aged men and women who were free of CHD, with either primary type IIa or IIb hyperlipidemia. The intervention used were specific HMG-CoA reductase inhibitors and fibrates at several dosages, which reduced total cholesterol 11-34% and increased high-density lipoprotein cholesterol 1-29%. The main outcome measure was the cost per year of life saved after discounting benefits and costs by 5% annually. The lifetime cost effectiveness of HMG-CoA reductase inhibitors (fluvastatin, lovastatin, pravastatin, simvastatin) and fibrates (bezafibrate, fenofibrate, gemfibrozil) for the treatment of primary hyperlipidemia varied according to patient population, the effectiveness of each drug in modifying lipid levels, and the price of each drug. The estimates of cost per year of life saved for HMG-CoA reductase inhibitors range from $19,886 to $73,632, and $16,955 to $59,488 for fibrates according to gender and type of primary hyperlipidemia. Fluvastatin 20 mg/day was significantly more cost effective than gemfibrozil 1200 mg/day for male patients with type IIa hyperlipidemia. Simvastatin 17.3 mg/day or 20 mg/day yielded similar cost-effectiveness ratios compared with fibrates among type II hyperlipidemic patients. However, micronized fenofibrate was more cost effective than simvastatin 20 mg/day among type IIb patients. The cost effectiveness of lipid therapy varies widely and can be maximized by selecting specific drugs for specific lipid abnormalities.

Bezafibrate↗
PubMed1997

Rate of visual field loss in retinitis pigmentosa.

PURPOSE: The authors quantitate the rate of visual field loss in patients with retinitis pigmentosa as it relates to different clinical field phenotypes. PATIENTS AND METHODS: Goldmann visual fields were obtained with target V4e in 77 patients and with target II4e in 71 patients who had either isolated or various genetic types of retinitis pigmentosa and who met certain entrance criteria. The visual fields were categorized into five distinct clinical field phenotypes on the basis of their pattern of field loss. Mixed-model methods for the analysis of longitudinal data were used to model the natural logarithm of the visual field area as a function of patient age and clinical field phenotype. The average half-life (time over which half of the remaining field area would be lost) of the visual field area for each phenotype was computed from the results of this analysis. Visual field data were not analyzed for patients with a normal clinical field phenotype (type 1). RESULTS: Independent of the field phenotype, average half-life values were 7.3 years for target V4e and 6.8 years for target II4e, which were not statistically different (P = 0.16). Visual fields with partial or complete midperipheral ring scotomas (type 2) and those with only a residual central field (type 4) had a half-life of 9.5 and 9.4 years, respectively, for target V4e, and 8.9 and 8.0 years, respectively, for target II4e. Patients with partial peripheral restriction (type 5) lost visual fields with a half-life of 9.5 years for target V4e and 7.3 years for target II4e. None of these differences in the half-lives between the different phenotypes were statistically significant for either targets V4e or II4e. Fields with a residual central area and remaining temporal and/or nasal islands (type 3) had a half-life of 4.8 years for target V4e and 6.0 years for target II4e. The differences in half-lives between type 3 and each of the other field phenotypes were statistically significant for the V4e target, but not for the II4e target. CONCLUSIONS: The results of this study can be useful for counseling patients with retinitis pigmentosa and various visual field phenotypes as to their potential rate of visual field loss.

Half-Life↗
PubMed1997

Frequency of optic disc or parapapillary nerve fiber layer drusen in retinitis pigmentosa.

PURPOSE: To determine the frequency and characteristics of optic disc and parapapillary nerve fiber layer drusen in patients with retinitis pigmentosa and to attempt to document any differences in the frequency within different genetic subtypes of retinitis pigmentosa. METHODS: This retrospective case series reviewed 117 patients with autosomal-dominant, 84 with autosomal-recessive, and 61 with X-linked recessive forms of retinitis pigmentosa. Color fundus photographs were reviewed independently by three investigators. The presence of optic disc or parapapillary nerve fiber layer drusen was documented only when all three observers concurred as to their presence. The number (isolated or multiple), site (disc, parapapillary, or both), and bilaterality (unilateral or bilateral) were noted in each patient. RESULTS: Optic disc or parapapillary nerve fiber layer drusen or both were observed in 11 patients (9.4%) with autosomal-dominant, 6 patients (7.1%) with autosomal-recessive, and 7 patients (11.5%) with X-linked recessive types of retinitis pigmentosa. The differences in the observed frequencies were not statistically significant (P = 0.67). Overall, the frequency of optic nerve head or parapapillary drusen or both in 262 patients with retinitis pigmentosa was 9.2%. CONCLUSION: In a large population of patients with retinitis pigmentosa, our findings suggest that approximately 10% are likely to show optic nerve fiber layer drusen involving the optic disc or parapapillary regions or both. The frequency does not vary significantly between different genetic subtypes.

Adolescent↗
PubMed1997

Reproducibility of visual acuity measurements in patients with retinitis pigmentosa.

PURPOSE: To establish the normal short-term range of variation in the measurement of visual acuity in patients with retinitis pigmentosa. METHODS: Sixteen patients (31 eyes) with retinitis pigmentosa, whose visual acuity ranged from 20/25 to 20/200, participated in this prospective clinical study. The best-corrected visual acuity in undilated and in dilated conditions was recorded independently by two masked observers on two visits of each patient within a 2-week interval by means of the Early Treatment Diabetic Retinopathy Study charts (The Lighthouse, Long Island City, NY). RESULTS: Using mixed-model analysis, a reasonable upperbound for intervisit (intraobserver) variability of 6.0 letters for the visual acuity of patients with undilated pupils and 6.3 letters for the visual acuity of patients with dilated pupils and the corresponding maximum interobserver variability of visual acuity of 5.7 letters in patients with either undilated or dilated pupils on the Early Treatment Diabetic Retinopathy Study charts were computed. The overall average interobserver and intraobserver variability in visual acuity ranged from 1.3-2.3 letters. CONCLUSIONS: A change in visual acuity of seven letters or more on the standardized Early Treatment Diabetic Retinopathy Study charts may be considered important in patients with retinitis pigmentosa. For these patients with minor lens opacity, visual acuity measurements obtained with undilated and dilated pupils were similar. These findings help to establish guidelines for monitoring the response of visual acuity during any future therapeutic intervention trials or for determining substantial changes in visual acuity over time when the course of visual acuity loss in such patients is monitored.

Adult↗
PubMed1997

Efficacy of dorzolamide hydrochloride in the management of chronic cystoid macular edema in patients with retinitis pigmentosa.

PURPOSE: To compare the effectiveness of topical dorzolamide hydrochloride (Trusopt, Merck and Co., Inc., West Point, PA), a carbonic anhydrase inhibitor, with that of oral acetazolamide (Diamox; Lederle Laboratories, Pearl River, NY) for the management of chronic cystoid macular edema in patients with retinitis pigmentosa. METHODS: A prospective, double-masked, crossover study was conducted in five patients with retinitis pigmentosa who had chronic cystoid macular edema. After baseline visual acuity was measured and a fluorescein angiogram was obtained, each patient was randomly assigned to receive either topical dorzolamide or a placebo for 4 weeks, followed by a crossover for the same period. Oral acetazolamide then was given separately to each patient for 2 weeks. Each phase of the study was followed by a washout period of 4 weeks, during which the patient was taken off all medications. At each visit, best corrected visual acuity was measured, a fluorescein angiogram was obtained, a subjective assessment of the effects on visual function, and any side effects of the medication or placebo were recorded in the form of a questionnaire by an independent observer. RESULTS: Compared with baseline or placebo values, there was no measurable improvement in visual acuity on the Early Treatment Diabetic Retinopathy Study charts with dorzolamide in any of the patients. The visual acuity in three of five patients, however, improved by seven letters or more with acetazolamide. Compared again with baseline or placebo values, fluorescein angiograms of two of five patients showed improvement in macular edema in both eyes with the use of dorzolamide, whereas all five showed improvement with acetazolamide. The improvement in macular edema was more marked with acetazolamide than with dorzolamide. The effect of dorzolamide given three times a day was the same as that when it was given five times a day. One patient indicated that dorzolamide was more effective than acetazolamide in improving visual function, three of five patients believed that acetazolamide was more effective, and one felt that both were equally effective. CONCLUSION: Dorzolamide provided improvement in cases of macular edema on fluorescein angiograms and subjective improvement of visual function in some patients with retinitis pigmentosa with cystoid macular edema. However, there was no measurable improvement in visual acuity with the topical use of this drug. Oral acetazolamide was found to be more effective than dorzolamide in managing macular edema and improving visual acuity.

Acetazolamide↗
PubMed1997

Antifungal attributes of lactic acid bacteria--a review.

Molds constitute a very important contaminating flora of dairy products. Contamination with undesirable molds has been a serious and frequently disturbing problem in the dairy industry that results in huge losses due to spoilage of cheese and other fermented foods incriminated by a variety of mycoflora such as Aspergillus, Penicillium, Fusarium, Rhizopus, and Mucor. The considerable drop in pH caused by the growth of lactic acid bacteria (LAB) in fermented milk makes such foods a breeding ground for the highly opportunistic fungi to proliferate and thrive, spoiling the products and effecting cost and its commensurate accessories. The major antimicrobial substances isolated from the LAB are found effective against bacteria only and their inhibition toward the growth of contaminating bacteria has been explored in detail. However, studies on the fungistatic properties of LAB are relatively rare. This article reviews the investigative studies on the antifungal aspects of different lactic acid bacteria and the prospects of this exceptional trait as a potential food biopreservative.

Animals↗
PubMed1996

Identification of cysteine 354 of beta-tubulin as part of the binding site for the A ring of colchicine.

The colchicine analog 3-chloroacetyl-3-demthylthio-colchicine (3CTC) is a competitive inhibitor of colchicine binding to tubulin, binds to tubulin at 37 degrees C, but not at 0 degree C, and covalently reacts with beta-tubulin at 37 degree C, but not at 0 degree C, in a reaction inhibited by colchicine site drugs. The approximate intramolecular distance between the oxygen at position C-3 in 3CTC and the chlorine atom of the 3-chloroacetyl group is 3 A. using decylagarose chromatography, we purified beta-tubulin that had reacted with 3-(chloromethyl-[14C] Carbonyl)-3- demethylthiocolchicine ([14C]3CTC). This beta-tubulin that had reacted with 3-(chloromethyl-[14C]carbonyl)- 3-demethythiocolchicine ([14C]3CTC). This beta-tubulin was digested with formic acid, cyanogen bromide, endoproteinase Glu-C, or endoproteinase Lys-C, and the radio-labeled peptide(s) were isolated. The sequences of these peptides indicated that as much as 90% of the covalent reaction between the [14C]3CTC and beta-tubulin occurred at cysteine 354. This finding indicates that the C-3 oxygen atom of colchicinoids is within 3 A of the sulfur atom of the Cys-354 residue, suggests that the colchicine A ring lies between Cys-354 and Cys-239, based on the known 9 A distance between these residues, and may indicate that the tropolone C ring lies between the peptide region containing Cys-239 and the amino-terminal beta-tubulin sequence, based on the labeling pattern observed following direct photoactivation of tubulin-bound colchicine.

Amino Acid Sequence↗
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↗