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Biomedical subjects

M Singh

Publications and source records attributed to M Singh.

At least 433 records · Page 24Linked to original sources

Two-year follow-up of a prospective randomised trial of electrovaporization versus resection of prostate.

OBJECTIVES: Transurethral electrovaporization of the prostate (TUVP) has become a popular, minimally invasive procedure to treat BPH with promising initial results. This study was conducted to compare the efficacy, safety and durability of TUVP with standard TURP. We report the 2-year follow-up. METHODS: 104 consecutive men with BPH admitted for surgery were randomised to TUVP (52 patients, mean age: 67.5 years) or TURP (52 patients, mean age: 70.2 years). 47 patients in each arm completed 2-year follow-up. RESULTS: Follow-up data at 2 years show a comparable, significant and maintained improvement in mean IPSS (TUVP: 4.3 vs. TURP: 6.3), quality of life score (TUVP: 1. 1 vs. TURP: 1.7), and maximum flow rate (TUVP: 22.4 vs. TURP: 21.2 ml/s) with fall in mean post-void residual volume (TUVP: 18.8 vs. TURP: 22.8 ml). Postoperative impotence reported in TUVP: 17% vs. TURP: 11% (p = 0.49) and retrograde ejaculation TUVP: 72% vs. TURP: 89% (p = 0.47). Two patients in each arm (4%) had urethral stricture and 2 patients (4%) in the resected group had bladder neck stricture. Four patients in each group required re-operation for residual adenoma during the 2 years (4% in each arm each year). CONCLUSIONS: Our 2 years' follow-up results suggest that TUVP is as effective as standard TURP in the treatment of moderate-sized BPH with comparable durability.

Aged↗

Possible mechanism of alprazolam-induced amnesia in mice.

Alprazolam produced anterograde as well as retrograde amnesia in mice assessed using elevated plus-maze. Flumazenil (10 mg/kg i.p.) attenuated anterograde and retrograde amnesia produced by alprazolam. It is proposed that anterograde amnesia produced by alprazolam may be mediated through the activation of benzodiazepine receptors. Retrograde amnesia of alprazolam may be mediated through the blockade of PAF receptors. Moreover, flumazenil facilitates learning and memory perhaps by modulating the release of PAF and consequently attenuated alprazolam and BN-50730-(PAF receptor antagonist)-induced retrograde amnesia.

Alprazolam↗

Harm reduction and street-based program: looking into Nepal.

In August 1991 the Lifesaving and Lifegiving Society (LALS) became the first nongovernmental organization in Nepal to work with injecting drug users (IDUs) to reduce the harm caused by drugs in order to prevent HIV/AIDS. Its mission is to provide education, counseling, and primary health care, as well as bleach, sterile water, condoms, and new needles and syringes to IDUs to lower their risk of acquiring blood-borne diseases. An evaluation of the program found that the prevalence of HIV infection among IDUs who were in regular contact with the program from 1991 to 1994 was 1.6%. No new cases of HIV infection were detected among participants in either 1993 or 1994. Though a harm reduction program is expensive to implement and sustain in Nepal, through its nonjudgmental, noncoercive, and confidential philosophy, LALS has engaged drug users into recovery and given them a platform by which they are able to address their concerns in a public forum.

Community-Institutional Relations↗

Behavioural alterations in rats induced by single prenatal exposure of haloperidol.

Haloperidol (50 mg/kg, i.p.) treatment was given once to two different groups of pregnant Charles Foster rats on gestational day 9 and 14, these being respectively the critical periods of neural morphogenesis and rapid neural cell proliferation in this species. Pregnant control rats were similarly treated with equal volume of vehicle. The pups born were subjected to open-field exploratory behaviour and elevated plus-maze behaviour tests of anxiety and learned helplessness test of depression at 9 weeks of age. The results indicate that prenatal haloperidol treatment on gestational day 14 induces a significant increase in open-field ambulation and faecal droppings whereas haloperidol treatment on gestational day 9 caused significantly decreased rearing and unaltered ambulation in rat offsprings. Rat offsprings treated with haloperidol on gestational day 9 and 14 also displayed significant anxiogenic behaviour pattern on elevated plus-maze. Significantly increased number of escape failures were observed in learned helplessness tests indicating presence of depression in haloperidol treated rat offsprings. These behavioural alterations were found to be more marked in rat offsprings treated with haloperidol on gestational day 14. The results suggest that prenatal single exposure of high dose of haloperidol during critical period of neural cell proliferation leaves a lasting imprint on offsprings resulting in abnormal emotional state.

Animals↗

Pregnancy wastage in rural Varanasi: relationship with maternal nutrition and sociodemographic characteristics.

OBJECTIVE: To study the relationship between pregnancy wastage and matrnal undernutrition and other sociodemographic factors in rural Indian women. SETTING: Rural community of Varanasi. DESIGN: Longitudinal observation. METHOD: In 49 villages during 1988-92, 8111 pregnancies were registered to observe for wastage. The pregnancy outcome was correlated with various factors. RESULTS: There were 1321 abortions and 141 still births. Women's income < Rs. 250 per month, education < 10th class and protein intake < 50 g/day had significantly higher relative risks (RR) (4.1, 2.9 and 2.8, respectively) for abortions. Poor maternal nutrition was in additional important risk factor, for still births (RR 5.1 and 4.2 for maternal weight and height, respectively). A pregnancy interval over 2 years reduced both. CONCLUSION: Low socioeconomic status, chronic undernutrition and illiteracy in rural India are associated with high pregnancy wastage.

Abortion, Spontaneous↗

Effect of prenatal diazepam, phenobarbital, haloperidol and fluoxetine exposure on foot shock induced aggression in rats.

Different groups of pregnant rats were treated with diazepam (10 mg/kg), phenobarbital (10 mg/kg), haloperidol (0.1 mg/kg), fluoxetine (10 mg/kg) and vehicle (normal saline) intraperitoneally once a day during gestation days 13 to 21. After birth these pups were culled to 8 pups/dam and foster-nursed by lactating mothers for 3 weeks and were reared in colony cages thereafter. Sex and weight matched pairs of rat offsprings were subjected to foot shock induced aggression test at 8 weeks of age. Two parameters of aggressive behaviour were recorded namely, the latency to fight and total number of fighting bouts. The results indicate that prenatal exposure to diazepam, phenobarbital, haloperidol and fluoxetine caused significantly enhanced aggression in terms of number of fighting bouts.

Aggression↗

Preparation & standardization of the goat lung surfactant extract.

Exogenous goat lung surfactant extract (GLSE) was obtained by chloroform-methanol extraction of the centrifuged lung lavage. Four lungs provided around 250 mg of surfactant. GLSE has a phospholipid content of 50 percent, cholesterol of 1.5 percent and protein content under 1 percent. The preparation was bacteriologically sterile and had a shelf life of at least one month at 4 degrees C. Endotracheal administration of surfactant (50 mg/kg) in a rat lung model rendered surfactant deficient by saline lavage, restored the compliance characteristics to normal, thus documenting biological activity of the preparation. The cost of a course of 2 doses of surfactant replacement therapy was estimated to be as low as Rs 500/-. The study opens up the possibility of surfactant replacement therapy for the management of neonatal respiratory distress syndrome in India by an indigenous product at an affordable cost.

Animals↗

Haemorheological behaviour of erythrocytes & risk factor profile in patients suffering from Waldenström's macroglobulinaemia.

The plasma viscosity, haematocrit, and erythrocyte aggregation and deformability of blood samples of patients of Waldenström's macroglobulinaemia were measured by capillary viscometer, microcentrifuge, Myrenne aggregometer and filtrometer respectively and correlated with the serum IgM concentrations. The observed increase in plasma viscosity and erythrocyte aggregation and decrease in their deformability were attributed to the increase in the concentration of IgM. Haematocrit was also decreased compared to normal subjects. Based on these parameters a haemorheological risk factor profile was developed and an overall risk factor calculated. An increase in the risk factor in these patients was observed. The haemorheological profile and the calculated risk factors not only help in establishing the inter-relationship of these parameters in the disease state but also to evaluate the severity of the disease.

Aged↗

The light gene of Drosophila melanogaster encodes a homologue of VPS41, a yeast gene involved in cellular-protein trafficking.

Mutations in a number of genes affect eye colour in Drosophila melanogaster; some of these "eye-colour" genes have been shown to be involved in various aspects of cellular transport processes. In addition, combinations of viable mutant alleles of some of these genes, such as carnation (car) combined with either light (lt) or deep-orange (dor) mutants, show lethal interactions. Recently, dor was shown to be homologous to the yeast gene PEP3 (VPS18), which is known to be involved in intracellular trafficking. We have undertaken to extend our earlier work on the lt gene, in order to examine in more detail its expression pattern and to characterize its gene product via sequencing of a cloned cDNA. The gene appears to be expressed at relatively high levels in all stages and tissues examined, and shows strong homology to VPS41, a gene involved in cellular-protein trafficking in yeast and higher eukaryotes. Further genetic experiments also point to a role for lt in transport processes: we describe lethal interactions between viable alleles of lt and dor, as well as phenotypic interactions (reductions in eye pigment) between allels of lt and another eye-colour gene, garnet (g), whose gene product has close homology to a subunit of the human adaptor complex, AP-3.

Amino Acid Sequence↗

Discordance between FDG uptake and technetium-99m-HMPAO brain perfusion in acute traumatic brain injury.

A 28-yr-old woman who sustained a mild traumatic brain injury had an 18F-fluorodeoxyglucose (FDG) PET brain study using coincidence imaging performed on a dual-head gamma camera (MCD version; ADAC, Milpitas, CA) followed 24 hr later by 99mTc-hexamethyl propyleneamine oxime SPECT brain perfusion imaging using a triple-head gamma camera (TRIONIX, Twinsburg, OH). The results of the SPECT brain perfusion study demonstrated decreased frontoparietal cortical brain perfusion, whereas 18F-FDG cerebral uptake was normal. Neuropsychological evaluation suggested frontal lobe involvement. This case demonstrates the possibility of discordance between brain perfusion and glucose uptake in acute mild traumatic brain injury.

Adult↗

Sequential analysis of the influence of blood storage on aggregation, deformability and shape parameters of erythrocytes.

The hemorheological and morphological changes in blood during storage under standardised conditions for 35 days were analysed by sequential determination of the variability of aggregation, deformability and shape of erythrocytes. The shape analysis was carried out by shape descriptors based on the projected area and perimeter, as measured by processing of erythrocyte images obtained from blood smears. The aggregation of erythrocytes was analysed from the data on the sequential variation of transmitted laser intensity after passing through the erythrocyte suspension. Similarly, the deformability of erythrocytes was determined in terms of passage time as obtained by analysis of flow of erythrocyte suspension through the cellulose membrane. The results show that the erythrocyte aggregation parameters and shape descriptors show significant variation, whereas the deformability is reduced (up to 5%) compared with that of the fresh samples. These variations may explain the observed changes in blood viscosity and viability of erythrocytes after their infusion in to the cardiovascular system.

Blood Preservation↗

The role of the p53 protein in the selective vulnerability of the inner retina to transient ischemia.

PURPOSE: To determine whether the p53 protein plays a role in the selective vulnerability of the inner retina to transient ischemia. METHODS: Transient retinal ischemia was induced using a high intraocular pressure (HIOP) model in the Sprague-Dawley rat for 60 minutes. Histopathologic outcome was determined 7 days after ischemia. In addition, analysis for evidence for apoptosis (TdT-dUTP terminal nick-end label [TUNEL] staining) and p53 protein expression (immunohistochemistry) was performed at several points during the reperfusion period. In a separate set of experiments, wild-type mice and two groups of transgenic mice, one homozygous and the other heterozygous for the p53 null gene, were also subjected to HIOP for 60 minutes, and histopathology was performed 7 days later. RESULTS: At 7 days subsequent to 60 minutes of ischemia in the rat, there was marked thinning of the inner retinal layers. There were scattered TUNEL-positive cells within the inner retina, peaking at 24 to 48 hours and persisting for at least 7 days. p53 immunochemistry demonstrated elevated protein levels within the inner retina; this finding peaked at 24 to 48 hours but was no longer present at 4 days after ischemia. TUNEL staining of the inner retina of the mouse was most prominent 24 hours subsequent to ischemia but persisted at 48 hours. Seven days subsequent to 60 minutes of ischemia in the wild-type and transgenic mice, histopathologic evaluation demonstrated preservation of the retinal histoarchitecture in the heterozygous group compared with the wild-type or homozygous animals. CONCLUSIONS: These data further support the hypothesis that the delayed cell death that occurs after transient retinal ischemia is, in part, apoptotic. In addition, they suggest a role for the p53 protein in the selective vulnerability of the inner retina to transient ischemia. p53 protein may be a target for future therapeutic agents in the treatment of disorders of the retina where ischemia plays a pathogenetic role.

Animals↗

Absence of Helicobacter pylori in oral mucosal lesions.

A prospective study was conducted in 26 patients with benign oral ulcers and oral carcinoma and 26 age and sex matched controls to determine the prevalence of Helicobacter pylori in oral mucosal biopsies. Oral mucosal biopsies were subjected to rapid urease test, campylobacter like organism (CLO) test, histopathological examination and bacteriological culture for demonstration of H pylori. Urease test was positive for H pylori in 3 (11.4%) out of 26 cases and CLO test in 2 (14%) out of 14 cases. On histology, H pylori was identified in 4 (15.38%) out of 26 cases. The spiral organism was universally absent in culture of both patients and controls. These pilot data negate the casual association of H pylori in oral mucosal lesions.

Biopsy, Needle↗