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Biomedical subjects

T Sharma

Publications and source records attributed to T Sharma.

At least 91 records · Page 5Linked to original sources
PubMed1998

Subretinal fibrosis and nonrhegmatogenous retinal detachment associated with multifocal central serous chorioretinopathy.

PURPOSE: To report the rare occurrence of subretinal fibrosis in patients with multifocal central serous chorioretinopathy and evaluate the role of systemic corticosteroids and the effects of laser photocoagulation on multifocal leaks. METHODS: A total of 29 patients (mean age, 37.7 years; 89.7% male) treated for subretinal fibrosis and multifocal central serous chorioretinopathy from 1983-1995 were reviewed retrospectively. Mean follow up was 26 months (range, 6.8-81 months). RESULTS: Retinal detachment involved the macula in 72.4% cases. Fluorescein angiography showed a mean of 6.7 (range, 2-22) central serous chorioretinopathy leaks and a mean of 1.8 (range, 1-5) retinal pigment epithelial detachments. The fundus pictures of 23 patients who were taking systemic corticosteroids showed no improvement. Following laser treatment, however, retinal reattachment was obtained in all eyes, and improvement in visual acuity of > 2 Snellen lines was noted in 68.9% of patients. CONCLUSIONS: The presence of subretinal fibrosis with secondary retinal detachment in otherwise healthy young patients, particularly in men, should alert the physician to look for multifocal central serous retinopathy leaks. Systemic corticosteroids did not prove effective in treating these patients, although laser treatment is recommended for each leak identified on an angiogram.

Adult↗
PubMed1998

Management of glass intraocular foreign bodies.

PURPOSE: To describe the results of management of glass intraocular foreign bodies (IOFBs). METHODS: A total of 51 eyes of 43 patients that sustained penetrating injury with glass IOFB were studied retrospectively. A total of 23.5% had IOFB only in the anterior segment; the rest had IOFB in the posterior segment alone or in both the anterior and posterior segments. Six eyes were followed conservatively despite IOFB in a functional eye. Removal of IOFB was combined with repair of retinal detachment (where present) using internal tamponade with gas or silicone oil or buckle. RESULTS: After a mean follow-up of 16.8 months, 66.7% of eyes recovered better than 6/60 (20/200) vision and 75.6% had attached retina. On univariate analysis, scleral entry wound, posterior segment IOFB, larger size of IOFB, and retinal damage were found to be associated with poor anatomic outcome. Lower presenting visual acuity, hyphema, retinal damage, subretinal hemorrhage, detached retina, and larger IOFB were associated with a poor functional result. Multivariate analysis identified retinal damage caused by the foreign body as the only factor significantly associated with poor anatomic as well as functional outcome. CONCLUSIONS: Glass IOFBs are caused in a majority of cases by blast injury. Bilaterality is not uncommon. Presence of retinal damage is predictive of poor functional and anatomic results. Overall results are modest with modern vitreoretinal surgical techniques.

Adult↗
PubMed1998

Minor physical anomalies in familial and sporadic schizophrenia: the Maudsley family study.

OBJECTIVES: (1) To test the hypothesis that minor physical anomalies are increased in patients with schizophrenia and (2) to investigate differences in the prevalence of minor physical anomalies in patients with familial and sporadic schizophrenia and their first degree relatives. METHODS: A weighted Waldrop assessment was carried out on 214 subjects in five groups: schizophrenic patients from multiply affected families; first degree relatives of these familial schizophrenic patients; sporadic schizophrenic patients; first degree relatives of these sporadic schizophrenic patients, and normal controls. Broad and narrow criteria for abnormality were defined based on the distribution of minor physical anomalies in the control group. RESULTS: (1) The total schizophrenic group did not have a significant increase in minor physical anomalies using a narrow criterion of abnormality, but did when a broader criterion was used. (2) A significant increase in the proportion of subjects with an abnormally high number of minor physical abnormalities was shown in the group of sporadic schizophrenic patients (uncorrected p<0.01). Separate analyses for males and females showed a significant increase in the male sporadic group (uncorrected p<0.05), and a smaller non-significant increase in the female sporadic group. Neither the familial schizophrenic group nor either group of first degree relatives showed any significant increases in the proportion of patients with high abnormality scores. CONCLUSION: This work supports prenatal developmental abnormality as a mechanism for sporadic, but not familial, schizophrenia.

Adult↗
PubMed1998

Unusual chromosomal organization of telomeric sequences and expeditious karyotypic differentiation in the recently evolved Mus terricolor complex.

The Mus terricolor complex displays a stable homozygous arrangement of autosomal heterochromatin variations in the form of accretion of definitive autosomal short arms among three nonoverlapping populations, in concert with an expeditious evolutionary differentiation into three chromosomal species: M. terricolor I, II, and III. In contrast to the highly conservative M. musculus-like chromosomes in the coexisting sibling species, M. booduga, reshuffling and differentiation of centric heterochromatin has occurred in harmony with a revision of centric configurations, resulting in acrocentric and submetacentric autosomes. The chromosomal distribution of the prevalent vertebrate telomeric sequence (TTAGGG)n was examined by fluorescence in situ hybridization to metaphase cells of M. terricolor I, II, and III. An unusual centric organization of internal telomeric sequences was detected in all the submetacentric and acrocentric autosomes. An auxiliary role of these presumably fragile, recombinogenic telomeric sequences in the evolutionary revision of centric configurations in the terricolor complex is hypothesized.

Animals↗
PubMed1998

Saccadic eye movements in families multiply affected with schizophrenia: the Maudsley Family Study.

OBJECTIVE: Family studies have shown that abnormalities of smooth pursuit eye movement are increased in the adult relatives of schizophrenic probands as well as in the probands themselves. More recently, an inability of schizophrenic subjects to inhibit reflexive saccades reliably has been shown. This study aimed to test the hypothesis that the latter dysfunction is part of the extended schizophrenia phenotype. METHOD: With the use of infrared oculography, measurements of reflexive saccades and antisaccades were undertaken in 29 probands with schizophrenia, 50 of their nonpsychotic first-degree relatives, and 38 unrelated healthy volunteers. RESULTS: Probands, relatives, and healthy subjects showed no overall differences in the generation of reflexive saccades. However, in the antisaccade task, probands showed more saccadic distractibility when they were required to inhibit reflexive saccades. Analysis of corrective saccades showed that this was not due to failed comprehension or motivation. Relatives of the probands with high saccadic distractibility showed a higher distractibility rate than relatives of the probands with normal distractibility. Across all subjects, females showed a higher rate of distractibility errors than males. CONCLUSIONS: The ability to suppress reflexive saccades is an objective neurocognitive measure that is impaired in schizophrenic patients and in a proportion of their biological relatives. This antisaccade abnormality may be a vulnerability marker in a subset of schizophrenic patients and their families.

Adult↗
PubMed1998

Brain changes in schizophrenia. Volumetric MRI study of families multiply affected with schizophrenia--the Maudsley Family Study 5.

BACKGROUND: Structural brain abnormalities have been reported in schizophrenia. We tested the hypothesis that these abnormalities represented a marker for the genetic liability to schizophrenia in a sample of people with schizophrenia and their relatives from families multiply affected with the disorder. METHOD: We compared 31 people with schizophrenia, 57 relatives and 39 unrelated control subjects. Volumetric measurement of brain structures was carried out using stereological principles from three-dimensional reconstructed magnetic resonance images. RESULTS: Subjects with schizophrenia had larger lateral ventricles than their relatives and the normal control subjects. Relatives who were 'presumed obligate carriers' had larger left lateral ventricles than other relatives and the control subjects. Subjects with schizophrenia showed smaller whole brain and cerebellar volumes and larger lateral ventricles than their age- and gender-matched unaffected siblings. CONCLUSIONS: In families multiply affected with schizophrenia lateral ventricular enlargement distinguishes people with schizophrenia and presumed obligate carriers from other relatives and unrelated control subjects. These changes may be a marker for a genetic liability to schizophrenia.

Adult↗
PubMed1998

Impact of Spherix (Bacillus sphaericus B-101, serotype H5a, 5b) spraying on the control of mosquito breeding in rural areas of Farrukhabad District, Uttar Pradesh.

Spray impact of Spherix (Bacillus sphaericus B-101, Serotype H5a, 5b) was assessed against larval and adult populations of mosquito species in rural areas of Farrukhabad district, Uttar Pradesh. High mortality (> 95%) was observed against anopheline and culicine larvae within 48 h of spray @ 1 g/sq m. But the biolarvicidal effect declined within a week which indicated nonrecycling capacity and weekly reapplications were required. The encouraging results obtained through weekly sprays were short-lived because of decline in efficacy in some perennial intradomestic Culex breedings after 15 rounds of spray. The two year intensive field trials, however, had no appreciable impact on adult densities of both malaria vector An. culicifacies and bancroftian filariasis vector Culex quinquefasciatus. Environmental disturbances and manmade problems also affected the efficacy of the biolarvicide.

Animals↗
PubMed1998

Endophthalmitis in eyes following vitrectomy.

The authors describe two patients who underwent pars plana vitrectomy for nonclearing vitreous hemorrhage. Both patients had severe pain, increased intraocular pressure, and orbital swelling. The anterior chamber became flat in a phakic eye. The infection progressed rapidly, and ultimately evisceration was required in both cases. The presence of a flat anterior chamber in gas-filled, phakic eyes and a severe orbital inflammatory reaction in the early postoperative period should alert the physician to the possibility of endophthalmitis.

Cataract Extraction↗
PubMed1997

Memory and intellectual deficits do not decline with age in schizophrenia.

Cognitive deficits in schizophrenia are reported to be more consistent with a static encephalopathy than a dementing disorder. This study investigates memory and intellectual decline in 62 chronic schizophrenic subjects using the Wechsler Adult Intelligence Scale-Revised (WAIS-R), the Rivermead Behavioural Memory Test and the National Adult Reading Test (NART) in a cross-sectional study using five age cohorts (18-29, 30-39, 40-49, 50-59 and 60-69 years of age) and then by two cohorts (young: 18-39; older: 40-69). A second method of investigating intellectual decline was implemented by estimating the discrepancy score between WAIS-R (current IQ) and NART (premorbid IQ) for each subject. No significant differences were found in WAIS-R Full Scale. Verbal and Performance IQ and memory functioning across the five age cohorts (and when using two age groups). A significant difference in test scores was found using the Picture Completion and Digit Symbol subtests of the WAIS-R. The differences were not related to age or duration of illness. No significant difference in scores were evident in the remaining WAIS-R subtests. These results support previous findings that schizophrenia is more consistent with a static encephalopathy than a dementing disorder and that intellectual and memory function does not markedly decline with age.

Adolescent↗
PubMed1997

The Maudsley Family Study, II: Endogenous event-related potentials in familial schizophrenia.

Auditory event-related potentials (ERPs) were obtained from 33 schizophrenics, from 16 families multiply affected with schizophrenia, 57 of their non-schizophrenic first-degree relatives and 32 unrelated healthy controls. Transmission of schizophrenia in these families appeared unilinear with one parent only transmitting the disorder. Consequently, we were able to identify 10 presumed obligate carriers and study eight of them. Schizophrenic patients showed latency prolongation and amplitude reduction of the N100, N200 and P300 waves compared to controls. Their relatives showed similar abnormalities compared to controls. There was a trend for bimodal distribution of the P300 latency in the relatives, with 20 (35%) of them falling outside two standard deviations of the mean of the controls. These included six of the eight obligate carriers. Our results suggest that ERP abnormalities may serve as markers of genetic vulnerability in schizophrenia and may be useful in genetic linkage studies.

Adult↗
PubMed1997

A multivariate analysis of anatomic success of recurrent retinal detachment treated with pneumatic retinopexy.

PURPOSE: The purpose of the study is to determine the success rate of pneumatic retinopexy (PR) after failed scleral buckling and to elucidate the predictors for anatomic failure by multiple logistic regression analysis. METHODS: Thirty-six eyes with recurrent retinal detachment after failed scleral buckling underwent PR. Intraocular tamponade was attained with SF6 (20 eyes), C3F8 (13 eyes), and air (3 eyes). Median follow-up was 14 months. RESULTS: Retinal reattachment was obtained in 69.4%. Multivariate analysis identified two risk factors for failure: location of retinal break either on the posterior slope or posterior to buckle (P = 0.01) and extent of retinal detachment greater than two quadrants (P = 0.02). CONCLUSIONS: Pneumatic retinopexy is an effective alternative to revision surgical operations if the leaking retinal break is located on the buckle.

Adolescent↗
PubMed1997

Parabulbar anesthesia for primary vitreoretinal surgery.

PURPOSE: The efficacy and safety of parabulbar anesthesia was investigated prospectively in 100 patients undergoing primary vitreoretinal surgery. METHODS: The technique involved three steps: (1) orbicularis oculi injection, (2) subconjunctival injection, and (3) sub-Tenon irrigation. The effect of anesthesia was graded 0 to 5 depending on inadequate anesthesia-akinesia with or without local supplementation. Ninety-three patients underwent vitrectomy without buckling and 4 with an encircling band; 3 had scleral buckling. Mean duration of surgery was 89.38 minutes. RESULTS: In 69% of patients (grades 4 and 5), no supplementation was required and in 31% (grades 1-3), local supplementation was needed for inadequate anesthesia or akinesia or both. No ocular or systemic complication occurred. Early onset of anesthesia correlated with adequate anesthesia throughout the procedure (P < 0.04). CONCLUSIONS: Parabulbar anesthesia is a safe and effective technique of local anesthesia in patients undergoing primary vitreoretinal surgery.

Adult↗
PubMed1997

The Maudsley Family Study. I: Structural brain changes on magnetic resonance imaging in familial schizophrenia.

1. The authors investigated the prevalence of qualitatively rated structural brain abnormalities in schizophrenic probands and their first-degree relatives from families multiply affected with schizophrenia. 2. Magnetic resonance imaging was used to evaluate brain morphology in 33 schizophrenic probands, 54 of their non-schizophrenic first-degree relatives (including 11 presumed obligate carriers) and 37 unrelated control subjects. Structural images were examined by a neuroradiologist who was blind to diagnostic and family status. 3. 52% of the schizophrenic subjects were rated as showing abnormalities compared with 27% of presumed obligate carriers, 16% of their non-schizophrenic relatives and 11% of unrelated controls. 4. Brain abnormalities were more frequent in schizophrenic subjects from multiplex families than in their first-degree relatives and controls. Abnormalities were also found in unaffected relatives particularly those who appear to be transmitting the disorder.

Adult↗
PubMed1997

Small planum temporale volume in Down's syndrome: a volumetric MRI study.

OBJECTIVE: Down's syndrome is associated with structural brain abnormalities and language deficits. The aim of this study was to investigate whether the superior temporal gyrus and the planum temporale, both parts of the anatomic substrate for language, are abnormal in Down's syndrome. METHOD: The authors examined volumetric magnetic resonance imaging (MRI) measures of the superior temporal gyrus and the planum temporale for 17 community-dwelling patients with Down's syndrome and 17 matched healthy comparison subjects. For the subjects with Down's syndrome, the correlations of the superior temporal gyrus and planum temporale volumes with performance on tests of language function were examined. RESULTS: The planum temporale volume of the patients with Down's syndrome was smaller than that of the healthy subjects, even after differences in whole brain volume were controlled for. The volume of the superior temporal gyrus in the Down's syndrome patients was proportionally similar to that of the comparison group. For the subjects with Down's syndrome, neither superior temporal gyrus nor planum temporale volume was significantly correlated with performance on language tests after total brain volume was controlled for. CONCLUSIONS: In Down's syndrome, planum temporale volume may be selectively smaller than normal, although the effect of this volume deficit on language is not clear.

Adult↗
PubMed1997

The Maudsley Family Study. 4. Normal planum temporale asymmetry in familial schizophrenia. A volumetric MRI study.

BACKGROUND: Loss or reversal of the normal asymmetry of the planum temporale (PT) has been reported in schicophrenia, and may be due to aberations in the gene(s) controlling the development of brain asymmetries. We tested this hypothesis in a sample of schizophrenics and their relatives from families multiply affected with the disorder. METHOD: We compared 32 schizophrenics and 55 of their non-schizophrenic first-degree relatives with 39 matched community controls. Volumetric measurements of the cortical volume beneath the PT were obtained using the Cavalieri method from three-dimensionally reconstructed magnetic resonance imaging images. RESULTS: PT volume asymmetry coefficients from patients and their relatives did not differ significantly from those of the controls. Gender-specific analysis did not revealany differences. CONCLUSIONS: Abnormalities in PT volume asymmetry are not present in familial schizophrenia, where genetic factors appear to predominate.

Adult↗
PubMed1997

A case-control study of suprachoroidal hemorrhage during pars plana vitrectomy.

BACKGROUND AND OBJECTIVE: To investigate the risk factors associated with suprachoroidal hemorrhage (SCH) during vitrectomy. PATIENTS AND METHODS: Of 6971 pars plana vitrectomies performed between May 1988 and December 1994, SCH occurred intraoperatively in 12 (0.17%) cases. Forty-two age- and sex-matched control subjects were selected by computer-generated random numbers. Preoperative and intraoperative variables were subjected to univariate and conditional logistic regression analysis. RESULTS: Statistically significant risk factors for SCH after univariate analysis included myopia (P = .048), aphakia or pseudophakia (P = .024), rhegmatogenous retinal detachment (P = .044), scleral buckling and/or encirclage at vitrectomy (P = .029), and longer duration of surgery (P = .044). Multivariate analysis revealed independent risks associated with the absence of a lens and longer duration of the surgery. CONCLUSION: A knowledge of the risk factors involved with SCH helps the physician to identify patients who are at a greater risk for this complication.

Adult↗