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T Sharma

Publications and source records attributed to T Sharma.

At least 91 records · Page 5Linked to original sources
PubMed1999

Methods for diagnosis and treatment of stimulus-correlated motion in generic brain activation studies using fMRI.

Movement-related effects in realigned fMRI timeseries can be corrected by regression on linear functions of estimated positional displacements of an individual subject's head during image acquisition. However, this entails biased (under)estimation of the experimental effect whenever subject motion is not independent of the experimental input function. Methods for diagnosing such stimulus-correlated motion (SCM) are illustrated by application to fMRI data acquired from 5 schizophrenics and 5 normal controls during periodic performance of a verbal fluency task. The schizophrenic group data were more severely affected by SCM than the control group data. Analysis of covariance (ANCOVA) was used, with a voxelwise measure of SCM as a covariate, to estimate between-group differences in power of periodic signal change while controlling for variability in SCM across groups. Failure to control for SCM in this way substantially exaggerated the number of voxels, apparently demonstrating a between-group difference in task response.

Adult↗
PubMed1998

Primary vitrectomy for rhegmatogenous retinal detachment associated with choroidal detachment.

OBJECTIVE: This study aimed to report the success rate of primary vitrectomy, scleral buckling, and oral steroids in eyes with combined rhegmatogenous retinal detachment (RRD) and choroidal detachment (CD) and to compare these results with those reported in the literature for similar cases managed by scleral buckling alone. DESIGN: Consecutive case series. PARTICIPANTS: Twenty-one eyes of 21 consecutive patients with primary RRD associated with CD were examined. INTERVENTION: All patients were treated with systemic corticosteroids before surgery. Pars plana vitrectomy with scleral buckling or encircling or both were performed. MAIN OUTCOME MEASURES: Retinal reattachment rate and resolution of choroidal detachment were measured. RESULTS: At mean follow-up of 11.4 months, retinal reattachment was attained in 19 eyes (90.5%) compared to less than 53% reported in the literature for scleral buckling alone. With preoperative oral steroids, choroidal detachment regressed completely in 13 eyes (61.9%). In the remaining eyes with persistent choroidal detachment, suprachoroidal fluid was drained during vitrectomy. CONCLUSION: Aggressive treatment with oral steroids followed by pars plana vitrectomy and scleral buckling or encircling is recommended instead of scleral buckling alone in the management of combined primary rhegmatogenous retinal detachment and choroidal detachment.

Administration, Oral↗
PubMed1998

Surgical management of retinal detachments related to coloboma of the choroid.

OBJECTIVE: This study aimed to develop a rationale for the management of retinal detachments related to choroidal coloboma and to study the outcome of their management. DESIGN: The study design was a retrospective study. PARTICIPANTS: A total of 85 eyes of 81 patients with retinal detachments related to coloboma of the choroid participated. INTERVENTION: All eyes underwent pars plana vitrectomy with internal tamponade using silicone oil (80 eyes) or perfluropropane gas (5 eyes). Behavior of the retina on fluid-air exchange was used to guide the further steps of surgery. Endolaser was performed along the coloboma border. Silicone oil was removed in 80% of eyes. The main outcome measures were retinal reattachment and visual recovery. RESULTS: Recurrent retinal detachment occurred in 16.3% of silicone oil-filled eyes and 60% of gas-filled eyes. After silicone oil removal, 15.6% of eyes had recurrent retinal detachment. After a mean follow-up of 13.4 months, 81.2% of eyes had attached retina and 69.4% recovered equal to or better than 10/200 visual acuity. CONCLUSION: Retinal detachment secondary to coloboma of choroid is treated best by pars plana vitrectomy along with silicone oil tamponade. Gas tamponade has limited indications. Clinical evaluation of the extent of retinal detachment within the colobomatous area and the behavior of the retina on fluid-air exchange help the authors understand the pathogenesis of the retinal detachment and plan a rational therapy.

Adolescent↗
PubMed1998

Long term visual results of vitrectomy for Eales disease complications.

BACKGROUND AND OBJECTIVES: Complications of Eales disease can cause visual loss. Long term visual prognosis following vitrectomy for Eales disease complications has been studied. PATIENTS AND METHODS: Retrospective analysis of 64 eyes of 57 patients who underwent vitrectomy for Eales disease complications with a minimum follow-up of 60 months. RESULTS: 62.4% eyes at 2 months and 71.8% at 60 months had 6/60 or better visual acuity. Visual acuities for individual cases were quite stable at the 60 month follow up with 50 eyes (78.5%) either maintaining or improving upon their 2 month post operative visual acuity. CONCLUSION: Visual acuity improves after vitrectomy in majority of patients with Eales disease complications and remains stable on long term follow-up.

Adolescent↗
PubMed1998

Intraoperative mitomycin C and the corneal endothelium.

PURPOSE: Mitomycin-C (MMC) is a useful adjunct to high risk glaucoma surgery. No clinical data regarding the deleterious effect of mitomycin-C on the corneal endothelial cells are available. METHODS: Thirty eyes of 28 adult patients with high risk glaucomas were randomized to three groups. Group-I underwent a trabeculectomy alone, Group II, trabeculectomy with intraoperative 0.2mg/ml MMC and Group III, trabeculectomy with intraoperative 0.4mg/ml MMC. Preoperative and 3-month postoperative corneal endothelial cell counts were analysed. RESULTS: The percentage cell loss in Group I was 3.73+/-2.73%, in Group II 13.90+/-4.69% and in Group III 14.52+/-7.8%. Statistical analysis revealed a significant difference in cell loss between Group I and Group II and Group I and Group III, but not between Group II and Group III. CONCLUSION: There is a significant loss of corneal endothelial cells three months after trabeculectomy with adjunctive MMC.

Adult↗
PubMed1998

The cognitive efficacy of atypical antipsychotics in schizophrenia.

Cognitive dysfunction, a symptom of schizophrenia, has been recently identified as an important measure of outcome in the treatment of this disorder. Drug-mediated symptom improvement, the traditional measure of treatment success for schizophrenia, typically fails to associate with modifications of cognitive dysfunction, resulting in a failure of the patient to reintegrate into society. A paradigm shift is now required in the conceptualization of treatment success away from symptom decrement and towards treatments that improve cognitive function. Clozapine treatment has been shown to provide a significantly greater improvement in several domains of cognitive function, especially attention and verbal fluency, compared with conventional neuroleptics, whereas risperidone appears to have a beneficial effect on working memory. These results may be because of the normalization of dopamine function by clozapine and antagonism of 5HT2 receptors.

Antipsychotic Agents↗
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↗