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Biomedical subjects

D Sharma

Publications and source records attributed to D Sharma.

At least 73 records · Page 4Linked to original sources
PubMed1998

Factors affecting direct and correlated responses in a White Leghorn population under long-term selection for egg number.

1. Data on 13,773 pullets, the progeny of 30 to 50 sires and about 135 to 220 dams per generation of a strain of White Leghorn under long-term selection for part period egg production over 16 generations, were examined. 2. Realised genetic gain per generation was highly significant for egg production (2.55 eggs), egg weight (-0.51 g), age at sexual maturity (-2.30 d) and 40 week body weight (-11.73 g). 3. The significant genetic response of 4.46 to 4.72 eggs per generation was realised in the first 8 generations only, which was accompanied by a marked decline in egg weight (-1.67 and -0.79 g per generation) and in age at sexual maturity (-4.63 and -6.39 d per generation). The 20 and 40 week body weights showed significant improvement in the last 4 generations. 4. Realised heritabilities were much lower in the last 8 than in the first 8 generation. 5. The additive genetic variance for most traits, except 20 week body weight and genetic covariances of egg production with egg weight and age at sexual maturity, declined significantly. 6. Natural selection did not seem to play any major role. No appreciable change in fitness traits was observed in the selected line. 7. The time trends were non-significant for all the traits in the control line, indicating its stability over generations.

Animals↗
PubMed1998

In vitro transcription of c-jun gene using fractionated nuclear extract from regenerating rat liver.

Regenerating rat liver serves as a source of proliferating cells, such a system can be used to study the regulation of genes involved in proliferation. We have established an in vitro transcription capable of supporting accurate transcription of cloned c-jun gene using fractionated nuclear extract prepared from partially hepatectomized rat liver. EcoR I linearized plasmid -132/+170 jun-CAT containing c-jun gene promoter region (-132 to +170 nucleotides) was transcribed in an in vitro run-off transcription assay and a transcript of expected size i.e. 370 nucleotides was obtained. The intensity of the transcript was dependent on the concentration of fractionated nuclear extract as well as template. The transcription was alpha-amanitin sensitive indicating that it is directed by RNA polymerase II.

Animals↗
PubMed1998

Thermosensitive liposomal taxol formulation: heat-mediated targeted drug delivery in murine melanoma.

Taxol, an antitumour alkaloid which stabilizes microtubules, demonstrates marked activity against several tumours. However, due to its low aqueous solubility, Cremophor EL (polyoxyethylated castor oil) is used as the excipient in pharmaceutical drug preparations of taxol. This has toxic side effects, thereby limiting the clinical use of taxol in cancer therapy. The aim of this study was to design a novel taxol formulation using thermosensitive liposomes in order to eliminate the Cremophor EL vehicle and improve the antitumour activity of taxol by site-specific drug delivery. Temperature-sensitive liposomes encapsulating taxol were prepared using the natural lipids egg phosphatidylcholine and cholesterol in combination with ethanol. The liposomes have a phase transition temperature (Tm) of 43 degrees C. The in vivo efficacy of thermosensitive liposome encapsulated taxol was determined in B16F10 murine melanoma transplanted into C57BI/6 mice in combination with local hyperthermia. A significant reduction in tumour volume and an increase in survival time was observed in tumour-bearing mice treated with a combination of hyperthermia and thermosensitive liposome encapsulated taxol compared with animals treated with an equivalent dose of free taxol with or without hyperthermia. These results suggest that thermosensitive liposome encapsulated taxol in combination with hyperthermia may be useful in improving the therapeutic efficacy of taxol in the treatment of melanoma.

Animals↗
PubMed1998

Successful pregnancy in a patient with previous bladder exstrophy.

Bladder exstrophy is an unusual congenital anomaly. Patients becoming pregnant with such anomaly after surgical repair are even rarer. The present case reports a lower segment Caesarean section delivery of a living healthy baby in a woman who had been operated on for bladder exstrophy at the age of 18 years. This is the first case of this type seen in our institution in 35 years.

Adult↗
PubMed1998

Uterus didelphys, a rare cause for tubal sterilization failure.

Uterus didelphys is a rare congenital anomaly. It can result in a variety of misadventures even in the hands of an expert. The present case reports uterus didelphys as the cause for tubal sterilization failure. This is the first case of this type seen in our institution in 35 years.

Adult↗
PubMed1998

Differential components of the manual and vocal Stroop tasks.

In this study, four components of the Stroop effect were examined for manual word and vocal responses. The components were lexical, semantic relatedness, semantic relevance, and response set membership. The results showed that all four components were present in the vocal response task. However, in the manual word response task, the only component that produced significant interference on its own was response set membership. These results do not support predictions made by recent translation models (see W. R. Glaser & M. O. Glaser [1989] and Sugg & McDonald [1994]). A possible solution was suggested that located two sites for Stroop interference. The lexical, semantic relatedness, and semantic relevance effects were located in the lexical system, whereas the response set membership effect was located at a response selection stage.

Analysis of Variance↗
PubMed1998

Cryptosporidium and HIV.

To study the importance of cryptosporidium as a diarrhoea causing pathogen (using stool samples), a cohort study was conducted from 14-9-1994 to 14-3-1995 on injecting drug users in Imphal. Stool samples were also collected from close contacts of the patients of human immunodeficiency virus (HIV) infected cryptosporidium diarrhoea cases and patients of paediatric medicine ward of Regional Institute of Medical Sciences (RIMS), Imphal. A total of 9 cases of cryptosporidium diagnosed out of 11 HIV infected diarrhoea cases and 2 out of 11 personal contacts were found to be positive. Two cases with history of close contacts with HIV infected cryptosporidium diarrhoea cases were not suffering from diarrhoea. One out of 7 paediatric diarrhoea cases was found to be positive. Five out of 9 HIV infected cryptosporidial cases died within one month of diagnosis of cryptosporidium. The remaining 4 had improved and diarrhoea was controlled. One of the 4 did not show cryptosporidium any more in the stool sample.

Adult↗
PubMed1998

Regional effects of ageing on Na+,K(+)-ATPase activity in rat brain and correlation with multiple unit action potentials and lipid peroxidation.

Effects of ageing on Na+,K(+)-ATPase activity in crude synaptosomal fractions from the rat brain parietal cortex, hippocampus, striatum and thalamus has been studied. From 12 months to 24 months, a progressive decline in enzyme activity in the parietal cortex, hippocampus and striatum was found which correlated with increase in lipid peroxidation in the three brain regions. In the thalamus, ageing did not affect the enzyme activity and lipid peroxidation. Age-related decline in multiple unit action potentials was also observed in two brain regions, viz. hippocampus and parietal cortex. Statistical correlations calculated by Pearson's correlation coefficient showed that decline in Na+,K(+)-ATPase activity correlated to decline in multiple unit action potentials. There was rise in lipid peroxidation also and the data indicate that age-related changes in lipid peroxidation and Na+,K(+)-ATPase activity contribute to the deterioration of electrophysiological activity.

Action Potentials↗
PubMed1998

Antimicrobial prescribing pattern in an Indian tertiary hospital.

550 prescriptions of the indoor patients receiving antimicrobial drugs in the Departments of Internal Medicine, Surgery, Urology and Paediatrics were analysed for drug utilization studies. The prescribing frequency of one antimicrobial per prescription was maximum in Surgery and Urology (52.52%) and Internal Medicine (50.51%) whereas prescribing frequency of two antimicrobials was maximum in Paediatrics (59.9%). In all the departments, quinolones, aminoglycosides, cephalosporins and penicillins were frequently prescribed among which amikacin, ciprofloxacin, cefotaxime and cloxacillin were most preferred drugs, with a general tendency of prescribing newer antimicrobials. In majority of cases selection of antimicrobials was not based on microbiological confirmation. It is suggested that the use of newer and expensive antimicrobials should be kept reserved only for serious and life threatening situations.

Anti-Infective Agents↗
PubMed1998

Profile of young acute myocardial infarction in Harayana.

Profile of acute myocardial infarction (AMI) in young patients (below 40 years) was studied in a rural/semi-urban population. Out of the total 338 patients who were admitted to ICCU over a period of one year, 65 (19.2%) were aged 40 years or below (Range 14-40 years). Male:female ratio was 20:1. Majority of these young patients were thinly built, engaged in heavy physical work and belonged to lower socio-economic group. Smoking was the most common risk factor (87%); other risk factors were few. Majority of these young patients ignored chest pain and reported late to the hospital. However, despite this, incidence of complications/mortality was less in comparison to their older counterparts. The overall mortality was only 6% as compared to 21% in older age group. The study focuses our attention to the rising incidence of AMI in young individuals even in populations least prone to ischaemic heart disease. Smoking was the only modifiable risk factor which needs to be curbed with full force.

Adolescent↗
PubMed1997

Modelling repeated-series longitudinal data.

We present a model for describing repeated-series longitudinal data, that is, longitudinal data where each unit may yield multiple series of the same variable. Such data arise commonly in ophthalmologic studies, where one obtains measurements on the same variable for the right and left eyes at each clinic visit. We model the mean as a linear function of predictors, and assume that the error term is a sum of a random subject effect and a vector AR(1) process. We fit the model by maximum likelihood and assess the adequacy of the error assumptions by an extension of the empirical semivariogram. We apply our model for data from a clinical trial comparing two treatments for ocular hypertension and glaucoma, with intra-ocular pressure as the primary endpoint. Results suggest that autocorrelation within and between eyes is a significant feature of the variance model. Standard errors depend critically on the variance assumption.

Algorithms↗
PubMed1997

Sequential chemotherapy and radiotherapy for squamous cell esophageal carcinoma.

A Phase II study of sequential chemotherapy with 5-fluorouracil and cisplatin followed by radiotherapy was initiated to see whether the use of two therapies sequentially could have an effect on response rate. Thirteen patients with advanced squamous cell carcinoma of the esophagus were treated with 1,000 mg/m2/day 5-fluorouracil days 1-5 continuously and 100 mg/m2 cisplatin on day 1. An average of four cycles (range, one to nine) were given every 28 days; 11 patients received more than three cycles. The radiation consisted of 60 Gy over 6-8 weeks. There was only one (8%) complete response (CR) and 11 (85%) partial responses (PRs). Restaging after radiation revealed no conversion of PR to CR. Median survival was 39 weeks (range, 6-208+). Chemotherapy alone or its use sequentially with radiotherapy is inadequate, and newer approaches are needed to to improve survival.

Aged↗
PubMed1997

Nonunion of uterine incision: a rare cause of secondary postpartum haemorrhage: a report of 2 cases.

Secondary postpartum haemorrhage after Caesarean section due to non-union of the uterine incision is an unusual complication. Two women who had had lower segment Caesarean section for placenta praevia presented after 2 and 3 weeks respectively with shock due to massive postpartum haemorrhage. The uterine scars had not healed in both of these women who were managed by emergency subtotal hysterectomy.

Adult↗
PubMed1996

Medical cost savings through stroke prevention from 100 consecutive new carotid duplex scans.

Recent studies have shown that carotid endarterectomy for significant lesions lowers the risk of stroke and also reduces medical costs by averting the high costs of strokes. However, there has been no information on the cost effect of duplex ultrasound examination which has evolved as the prime means of discovering these carotid lesions. This study reviewed the findings and management of 100 consecutive new patients referred for duplex ultrasound management of the carotid arteries and the cost effects resulting. Seventy-three patients with < 70% stenosis were managed non-operatively; the remaining 27 with 33 lesions producing > 70% stenosis were treated by carotid endarterectomy. It was estimated that 6.5 patients would have had a stroke within 18 months if not operated on. While the medical costs of these strokes would have been $958,838, the cost of avoiding them was $300,494; the result was a significant medical costs saving of $658,344.

Carotid Arteries↗
PubMed1996

Novel Taxol formulation: polyvinylpyrrolidone nanoparticle-encapsulated Taxol for drug delivery in cancer therapy.

Taxol is a novel antitumor alkaloid that has shown clinical activity against several tumors. However, due to its low aqueous solubility, Cremophor EL (polyoxyethylated castor oil) and ethanol are used as excipients in the pharmaceutical drug formulations. These agents are implicated in hypersensitivity reactions. Hence the goal of this work was to design a novel Taxol formulation using polymeric nanoparticles to eliminate the Cremophor EL vehicle for drug delivery. Polyvinylpyrrolidone nanoparticles containing Taxol were prepared by a reverse microemulsion method. The size of the nanoparticles as determined by quasielastic light scattering was found to be between 50 and 60 nm. The antitumor effect of Taxol encapsulated nanoparticles was evaluated in B16F10 murine melanoma transplanted in C57B1/6 mice. The in vivo efficacy of Taxol-containing nanoparticles as measured by reduction in tumor volume and increased survival time was significantly greater than that of an equivalent concentration of free Taxol. These results suggest that encapsulation of Taxol in polymeric nanoparticles could be useful in improving its therapeutic efficacy in treatment of solid tumors.

Animals↗
PubMed1996

Age-related decline in multiple unit action potentials of cerebral cortex correlates with the number of lipofuscin-containing neurons.

The present study examined whether there is any obvious correlation between the density of lipofuscin-containing neurons and the spontaneous neuronal action potentials (Multiple Unit Activity, MUA) in the parietal cortex of the aging rat brain. The results showed that MUA counts were decreased with age while the number of lipofuscin-containing neurons was increased. The cortex with the highest percentage of lipofuscin-containing neurons had the lowest MUA counts while the cortex with the lowest percentage of lipofuscin-containing neurons had the highest MUA counts. The inverse correlation between MUA and lipofuscin-containing neuron number was also evident when the population of the lipofuscin-containing neurons was pharmacologically altered in vivo by the administration of anti-lipofuscin drug centrophenoxine. The inverse relationship between MUA and the lipofuscin-containing neuron numbers is consistent with: (i) the correlations of MUA with age-related changes in lipid peroxidation and biochemically measured lipofuscin concentration, and (ii) the oxidative stress-induced impairments of neuronal electrophysiology.

Action Potentials↗