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Biomedical subjects

R Singh

Publications and source records attributed to R Singh.

At least 289 records · Page 16Linked to original sources
PubMed1999

Mega dose intravenous methylprednisolone in bilateral simultaneous optic neuritis.

OBJECTIVES: The study was carried out to assess the efficacy of megadose intravenous methylprednisolone in patients of bilateral simultaneous optic neuropathy (BSON) of unknown etiology. METHODS: Fifteen consecutive patients admitted in neurology unit were included in the study. These patients were subjected to various investigations including MRI and CSF exam to exclude all known causes of optic neuropathy including multiple sclerosis. All patients were put on single dose intravenous methylprednisolone, 1 gm/day in adults and 500 mg/day in children for three days. Pre and post-treatment visual parameters including visual evoked potentials (VEP) were carried out. RESULTS: There was a female preponderance and the average age was 28 years. The visual acuity and P100 latences of visual evoked potentials (VEP) improved in all cases. The improvement was statistically significant (P < 0.001). CONCLUSION: Use of intravenous methylprednisolone is a preferred drug in bilateral simultaneous optic neuropathy (BSON) as compared to oral or retrobulbar steroids.

Adolescent↗
PubMed1999

Intravitreal tissue plasminogen activator in submacular haemorrhage.

Submacular haemorrhage is a major cause of sudden visual loss in age-related macular degeneration (AMD). If left untreated it often results in permanent central visual loss. We present our experience in the use of intravitreal tissue plasminogen activator (tPA) in a 65-year-old male with submacular haemorrhage.

Aged↗
PubMed1999

Epilepsy and paroxysmal movement disorders in families: evidence for shared mechanisms.

The epilepsies have been regarded as clinically distinct from the paroxysmal movement disorders. Recently, a variety of ion channel defects have been identified as the biological basis of certain familial epilepsies and paroxysmal movement disorders. We studied two families with the co-occurrence of epilepsy, movement disorders and migraine. Information was obtained on 147 individuals in the two families. In family WF, there was a co-occurrence of epilepsy (benign infantile convulsions, idiopathic generalized epilepsy), episodic ataxia (with cerebellar atrophy and without myokymia) and common migraine. In family CL, epilepsy (febrile seizures, febrile seizures plus), kinesigenic paroxysmal dyskinesia and migraine (including hemiplegic migraine) were observed in various combinations over 3 generations. The observations in these two families, together with review of the literature, suggest that the co-occurrence of epilepsy (particularly benign infantile convulsions), paroxysmal movement disorders and migraine is not due to chance. Thus, these distinct clinical phenomena could have a shared biological basis and ion channel defects are an attractive possibility.

Adolescent↗
PubMed1999

Sclerokeratoplasty versus penetrating keratoplasty in anterior staphyloma.

BACKGROUND AND OBJECTIVE: To assess the efficacy of the newer surgical technique of sclerokeratoplasty in spherical anterior staphyloma of the cornea and to compare it with total penetrating keratoplasty. PATIENTS AND METHODS: A randomized, prospective clinical trial in 20 eyes with acquired spherical anterior staphylomas was undertaken. Ten eyes each underwent sclerokeratoplasty (group 1) or total penetrating keratoplasty (group 2). The parameters evaluated were visual acuity, keratometry, graft status, and complications. Patients were observed for a minimum of 1 year. RESULTS: Best spectacle-corrected visual acuity of 6/60 or better with astigmatism of less than 3 D was achieved in all but one patient in group 1 in contrast to 5 cases in group 2. Postoperative complications included epithelial defects, shallow anterior chamber, hyphema, and uveitis, which did not significantly vary between the 2 procedures. Secondary glaucoma was significant associated with group 2 as compared with group 1. At the end of 1 year, no significant difference in the graft clarity was present. Grafts were clear 3+ or more in 8 eyes in group 1 and in 5 eyes in group 2. Good cosmetic results were achieved in cases of sclerokeratoplasty due to the absence of corneal opacification and suture marks. CONCLUSION: Sclerokeratoplasty is a useful alternative to total penetrating keratoplasty in cases of acquired spherical anterior staphylomas of the cornea with good anatomic and useful visual outcome.

Adult↗
PubMed1998

Functional comparisons among members of the poxvirus T1/35kDa family of soluble CC-chemokine inhibitor glycoproteins.

Many poxviruses express a 35-40-kDa secreted protein, termed "T1" (for leporipoxviruses) or "35kDa" (for orthopoxviruses), that binds CC-chemokines with high affinity but is unrelated to any known cellular proteins. Many previously identified poxvirus cytokine-binding proteins display strict species ligand-binding specificity. Because the T1 and 35kDa proteins share only 40% amino acid identity, we compared the abilities of purified myxoma virus-T1 (M-T1) and vaccinia virus (strain Lister)- and rabbitpox virus-35kDa proteins to inhibit human CC-chemokines in vitro. All three proteins were equally effective in preventing several human CC-chemokines from binding to target chemokine receptors and blocking subsequent intracellular calcium release. The inhibitory affinities were comparable (Ki = 0.07-1.02 nM). These proteins also displayed similar abilities to inhibit (IC50 = 6.3-10.5 nM) human macrophage inflammatory protein-1alpha-mediated chemotaxis of human monocytes. None of the viral proteins blocked interleukin-8-mediated calcium flux or chemotaxis of human neutrophils, confirming that the biological specificity of the T1/35kDa family is targeted inhibition of CC-chemokines. Despite the significant sequence divergence between the leporipoxvirus T1 and orthopoxvirus 35kDa proteins, our data suggest that their CC-chemokine binding and inhibitory properties appear to be species nonspecific and that the critical motifs most likely reside within the limited regions of conservation.

Calcium↗
PubMed1998

Predictors of HIV infection among newly sentenced male prisoners.

The prevalence of individuals with or at risk for HIV infection in prisons and jails is severalfold higher than age-adjusted rates in surrounding communities. This HIV serosurvey of 975 newly sentenced male prisoners employed a new methodology that anonymously linked individual information to HIV serologic data. The HIV prevalence was 6.1%; multivariate regression analysis indicated injection drug use (OR = 18.9), black race (OR = 5.5), Hispanic ethnicity (OR = 3.4), psychiatric illness (OR = 3.1) and a history of having had a sexually transmitted disease (OR = 2.2) were independent predictors of HIV infection. Laboratory markers such as hypoalbuminemia, an elevated aspartate aminotransferase (AST) level, leukopenia, anemia, and thrombocytopenia suggest increased risk for HIV among prisoners, particularly in settings where HIV testing resources are scarce. This study, unlike those reported in other geographic regions, indicated that the majority (71%) of HIV-seropositive persons self-reported their HIV status. This finding may suggest that HIV-infected individuals will self-report their status if HIV care is comprehensive and consistent. The large number of HIV-infected individuals within prisons makes prisons important sites for the introduction of comprehensive HIV-related care. This is particularly relevant in that development of new guidelines issued for the management of HIV infection in which potent combination antiretroviral therapy has been demonstrated to decrease morbidity and mortality. The high prevalence of HIV-seronegative inmates with self-reported high-risk behaviors also suggests the importance of prisons as sites for the introduction of appropriate risk-reduction interventions.

Adolescent↗
PubMed1998

Randomised controlled trial of laparoscopic versus open mesh repair for inguinal hernia: outcome and cost.

OBJECTIVE: To compare tension-free open mesh hernioplasty under local anaesthetic with transabdominal preperitoneal laparoscopic hernia repair under general anaesthetic. DESIGN: A randomised controlled trial of 403 patients with inguinal hernias. SETTING: Two acute general hospitals in London between May 1995 and December 1996. SUBJECTS: 400 patients with a diagnosis of groin hernia, 200 in each group. MAIN OUTCOME MEASURES: Time until discharge, postoperative pain, and complications; patients' perceived health (SF-36), duration of convalescence, and patients' satisfaction with surgery; and health service costs. RESULTS: More patients in the open group (96%) than in the laparoscopic group (89%) were discharged on the same day as the operation (chi2 = 6.7; 1 df; P=0.01). Although pain scores were lower in the open group while the effect of the local anaesthetic persisted (proportional odds ratio at 2 hours 3.5 (2.3 to 5.1)), scores after open repair were significantly higher for each day of the first week (0.5 (0.3 to 0.7) on day 7) and during the second week (0.7 (0.5 to 0.9)). At 1 month there was a greater improvement (or less deterioration) in mean SF-36 scores over baseline in the laparoscopic group compared with the open group on seven of eight dimensions, reaching significance on five. For every activity considered the median time until return to normal was significantly shorter for the laparoscopic group. Patients randomised to laparoscopic repair were more satisfied with surgery at 1 month and 3 months after surgery. The mean cost per patient of laparoscopic repair was 335 pounds (95% confidence interval 228 pounds to 441 pounds) more than the cost of open repair. CONCLUSION: This study confirms that laparoscopic hernia repair has considerable short term clinical advantages after discharge compared with open mesh hernioplasty, although it was more expensive.

Activities of Daily Living↗
PubMed1998

Similarity of strain- and route-dependent murine responses to an adenovirus vector using the homologous thrombopoietin cDNA as the reporter genes.

Replication-deficient adenovirus (Ad) vectors are effective in transferring genes in vivo, but their use is associated with significant variation in the extent and/or duration of expression observed among different strains of experimental animals and different routes of administration of the vector. We have minimized the variables of the heterologous transgene and animal-to-animal variation by constructing an Ad vector encoding murine thrombopoietin (mTPO, AdmTPO), a homologous protein that induces a physiologic response (elevation of blood platelet levels) that can be followed sequentially over time in the same animal. Using the C57BL/6 and BALB/c stains, liver administration was accomplished by intravenous administration and skeletal muscle administration by direct injection. Despite the use of a homologous cDNA as a transgene, the Ad genome was rapidly lost from the liver after intravenous administration over the first 1 to 2 weeks, with no difference in pattern of decline between the C57BL/6 and BALB/c strains. Both strains exhibited a cytotoxic T lymphocyte (CTL) response directed against the AdmTPO vector. Consistent with the decline in vector genome over time, the initial high levels of mTPO mRNA in the liver declined to an undetectable level within 2 weeks. Platelet counts peaked at 8- to 10-fold above baseline within the first 2 weeks, and then gradually declined, returning to normal level by 50 to 60 days. Intravenous administration of the AdmTPO vector to beta2-microglobulin-deficient mice resulted in a longer persistence of elevated platelets levels, although the eventual return of platelet levels to normal in these mice suggests the elimination of the Ad vector cannot be explained solely by CTL response. Although the intramuscular administration of the AdmTPO vector resulted in platelet levels with a lower peak and minor differences over time compared with the intravenous route, the C57BL/6 and BALB/c strains demonstrated the same rapid loss of Ad genome and mTPO mRNA levels in the muscle as in the liver. Together, these observations suggest that simplifying the experimental design by eliminating the variable of host response to a heterologous transgene, and by following the consequences of gene transfer in the same animals over time, there can be remarkable similarity in strain- and route-dependent responses to an Ad vector.

Adenoviridae↗
PubMed1998

Antiallergic/antiasthmatic activity of oligopeptide related to IgE.

In spite of continuous research in the field of bronchial asthma, still no satisfactory drug is available. Recently a new class of oligopeptide exhibited antiallergic activity by inhibiting the synthesis of IgE antibody. The analogue of ADSDGK (94-335) has shown antiallergic activity in experimental models. The 94-335 inhibited the passive cutaneous anaphylaxis (PCA) reactions in rats in a dose-dependent manner (0.5-10 mg kg-1 p.o.) by 47-90%. There was a 70-87% protection of mast cell degranulation induced by compound 48/80 with peptide 94-335 at 0.5-1.5 mg kg-1 p.o. in rats. This peptide also inhibited antigen- induced contraction in sensitised guinea pig ileum. There was 18 and 72% protection to bronchoconstriction induced by histamine and egg albumin, respectively, in an aerosol test in guinea pigs. These effects of compound 94-335 were comparable with that of the clinically-used antiallergic drug disodium cromoglycate (DSCG). The results suggest that peptide 94-335 possesses potent antiallergic activity.

Animals↗
PubMed1998

Phacoemulsification of white mature cataracts.

PURPOSE: To evaluate the intraoperative difficulties associated with phacoemulsification of white mature cataracts and develop a strategy for consistently achieving continuous curvilinear capsulorhexis (CCC) in these cases. SETTING: Raghudeep Eye Clinic, Iladevi Cataract & IOL Research Centre, Ahmedabad, India. METHODS: This prospective study comprised 60 eyes of 60 patients with senile white mature cataract. Mean follow-up was 7 months. Detailed preoperative and intraoperative notes were made including intraoperative subjective assessment of the intracapsular pressure and cataract hardness. A small capsulorhexis was attempted initially. Endophacoemulsification was performed using the stop, chop, chop, and stuff technique. The capsulorhexis was enlarged before intraocular lens implantation. An initial cut in the capsulorhexis margin was made with a cystotome needle while a spatula supported the anterior capsule. The capsulorhexis was then enlarged with forceps. RESULTS: A CCC was achieved in 57 eyes (95%). Intracapsular pressure was judged to be raised in 24 eyes (40%). Of these, CCC was accomplished in 21 eyes (88%). Statistical analysis confirmed that raised intracapsular pressure was a significant factor. Capsule opacification or plaque was detected at the end of the surgery in 20 eyes (33%); 50% of the nuclei were of grade 5 hardness. CONCLUSION: If a CCC can be achieved, the results of white cataract phacoemulsification are comparable to those of routine cataract surgery. When using the two-stage technique, one should be prepared to deal with a hard cataract through a small capsulorhexis.

Adult↗
PubMed1998

Relationship between lens and capsular bag size.

PURPOSE: To measure the size of the lens and the empty capsular bag and evaluate the relationship between them. SETTING: Iladevi Cataract & IOL Research Centre, Ahmedabad, India. METHODS: In 46 eye-bank eyes, the equatorial diameter of the lens was measured after a corneoscleral button and the iris were removed. Empty capsular bag diameter was measured after extracapsular cataract extraction through an intact capsulorhexis. RESULTS: Mean lens size was 10.20 mm +/- 0.38 (SD) and mean capsular bag size, 10.38 +/- 0.35 mm. The difference between the size of the lens and that of the empty capsular bag varied from 0 to 0.50 mm (mean 0.20 +/- 0.17 mm). Lenses measuring less than 10.25 mm in diameter showed an increase of 0.25 mm while lenses larger than 10.25 mm showed an increase of 0.09 mm. CONCLUSION: Lens size was larger in our population than in previous studies. The increase in the empty capsular bag size was related to initial lens size.

Aged↗
PubMed1998

Early closure of a randomized trial: surgery and postoperative radiotherapy versus radiotherapy in the management of intra-oral tumours.

Tumours of the oral cavity/oropharynx occur relatively infrequently in the UK. The management of such lesions, especially the squamous cell carcinomas, is still a little controversial. Some centres advocate radiotherapy while others adopt surgery and radiotherapy. In an attempt to resolve the question of which approach gives the better results, a multicentre randomized trial was established to compare surgery plus postoperative radiotherapy with radical radiotherapy alone. It was anticipated that 350 patients would be required to give a statistically significant result, but, after 35 patients had been entered, the trial was closed prematurely with a marked difference in overall survival in favour of the combination arm (P = 0.0006). At this analysis, carried out 23 months after trial closure, the survival difference between the two arms remains statistically significant for all causes of mortality (P = 0.001; relative death rate = 0.24; 95% CI 0.10-0.59).

Adult↗