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Biomedical subjects

A Kumar

Publications and source records attributed to A Kumar.

At least 307 records · Page 17Linked to original sources
PubMed2000

alpha-Tocopherol enhances tumour growth inhibition by cis-dichlorodiammine platinum (II).

Present studies indicate that alpha-tocopherol enhances the efficacy of cisplatin as demonstrated by inoculation of Dalton's lymphoma cells incubated with either cisplatin (5 or 10 microg/ml) alone or cisplatin + alpha-tocopherol (25 or 50 microg/ml) into C3H/He mice. Tumour cells (3 x 10(6) cells/mouse) incubated with cisplatin grow slowly in syngeneic mice as indicated by the late appearance of tumour. However, mice failed to develop tumour when inoculated with tumour cells incubated with cisplatin + alpha-tocopherol. When the animals were challenged with tumour cells (3 x 10(6) cells/mouse) on the 15th day after the initial inoculation, 30-50% survived more than 60 days, with 10% tumour-free survivors being observed in some groups. Antitumour activity was higher in mice receiving lymphoma cells (3 x 10(6) cells/mouse) preincubated with cisplatin + alpha-tocopherol compared to cisplatin alone. Tumour-bearing mice receiving cisplatin in combination with different concentrations of alpha-tocopherol exhibited significantly higher (P<0.001) intratumour platinum content (123-306%) but without any change in the kidney platinum content as compared to those receiving cisplatin (5 or 10 microg/ml) alone. Enhancement of cisplatin-induced tumour growth inhibition is probably due to the modulation of tumour cell membrane permeability by alpha-tocopherol. alpha-Tocopherol might increase the influx of cisplatin into tumour cells, causing the DNA repair machinery to be less efficient due to increased efficiency of adduct formation in the DNA molecule. This effect of alpha-tocopherol can render cisplatin more effective as an antitumour agent.

Animals↗
PubMed2000

Immediate loading of implants in partially and fully edentulous jaws: a series of 27 case reports.

BACKGROUND: The concept of immediate loading of dental implants has been researched in animal and man. High predictability with titanium screw implants can be expected under certain circumstances. Delayed loading, which is empirically based, may offer roadblocks to success in the complex case. Micromotion under a denture, retention of compromised teeth, and the necessity for multiple implant surgeries complicate the situation. The present study was undertaken to demonstrate whether in partial and fully edentulous patients, titanium screw implants may be installed and loaded within 72 hours. METHODS: The study included 27 jaws (23 mandibles and 4 maxillas) in patients who refused to wear a denture or were told of the possibility of immediately loading their implants. Criteria similar to delayed loading was utilized. The patient had to have adequate volume and density for a minimum of 4 (10 mm) implants in the mandible and 6 in the maxilla, in addition to other requirements. After a thorough presurgical evaluation by the restorative dentist, a template and heat-cured/metal-reinforced provisional were fabricated. Following fixture installation, either the fixed provisional was placed or an impression was taken, and the provisional was seated within 72 hours. Once the temporary was placed, it remained until osseointegration was complete. RESULTS: Success rates similar to those in delayed loaded cases may be expected (95%). Fewer sandblasted/acid-etched titanium screws were lost than machined titanium screws. All patients went on to completion of their original prosthetic prescription. CONCLUSIONS: Patients who are partially or fully edentulous may predictably be restored with fixed implant prostheses immediately upon fixture placement if certain parameters are met.

Aged↗
PubMed2000

Relapses in multibacillary leprosy patients: effect of length of therapy.

Two groups of MB leprosy patients, one treated to the point of smear negativity (TSN) and the other given therapy for fixed duration (24 doses of WHO MB regimen) (FDT), were compared for relapse rates during treatment and in the post-treatment period. During the follow-up of 980.2 person years in 260 patients treated with FDT, 20 relapses (2.04/100 patient years) were observed. In the other group of 301 patients, who received therapy till smear negativity, 12 relapses in 1085.46 person years (1.10/100 patient years) occurred. Comparison of survival rates (without relapse) has shown that although there is no difference up to 4 years, the risk of relapse was significantly higher on longer follow-up in the FDT group. In addition, when patients were compared on the basis of initial bacterial load, it was found that the relapse rates in patients with BI > or = 4 was significantly higher (P < 0.01) in the FDT group as compared to those receiving treatment till the point of smear negativity (4.29 versus 1.27/100 patient years). All the relapsed patients responded to retreatment with the same drug combination, indicating that the exacerbation in their condition was because of insufficient treatment. It is suggested that to prevent or reduce relapses, treatment where feasible would be continued till smear negativity, at least in patients with high BI.

Adolescent↗
PubMed2000

Expanding the living related donor pool in renal transplantation: use of marginal donors.

PURPOSE: In a living related transplantation program it is not always possible to find an ideal donor. Sometimes the only available donor in the family has some benign disease or suboptimal renal anatomy or physiology, or is too old to be accepted and defined as a marginal donor. However, with proper screening the donor pool can be increased by accepting these marginal donors and treating the benign diseases which is beneficial to the donor. We evaluate the outcome of grafts from marginal donors. MATERIALS AND METHODS: From July 1988 to August 1997, 581 live related transplantations were performed. Of the donors 52 were older than 60 years and 34 had associated benign renal or nonrenal anomaly or disease. These donors were accepted after thorough questioning and consultation with family members. The recipients of graft from elderly donors were evaluated for the number of rejections, serum creatinine at last followup and graft survival. RESULTS: Of the recipients 52 received grafts from elderly donors with a mean age of 62.6+/-3.7 years. Mean followup was 34.14+/-0.7 months. The 2 and 5-year actuarial graft survival was 96% and 74%, respectively. Creatinine was normal (less than 1.5) in 37% of recipients and 1.5 to 2.5 mg.% in 46%. The rejection rate in postoperative month 1 was 29%. All donors underwent simultaneous surgery to treat the benign disease, and all did well after surgery. CONCLUSIONS: By accepting these marginal donors a 14.6% increase in the living related donor pool was achieved without compromising recipient or donor safety. Otherwise these recipients would have been forced to undergo unrelated transplantation or be maintained on dialysis, which is particularly difficult in a developing country. Donors with associated disease benefited from cure.

Female↗
PubMed2000

Mesh repair of a coccygeal hernia via an abdominal approach.

We report on the presentation and management of a patient with herniation of the rectum following a coccygectomy. We used an abdominal approach and careful pelvic dissection to define the defect in the pelvic floor at the site where coccyx used to be. Prolene mesh repair resulted in the reduction of the hernia. To our knowledge, this is the first report on the mesh repair of the coccygeal hernia via an abdominal approach.

Aged↗
PubMed2000

HIV infection among children in Barbados.

We studied a cohort of children with the human immunodeficiency virus (HIV) infection in Barbados in order to determine the prevalence of HIV infection, the clinical course including morbidity and mortality and the magnitude of the health care and social problems. Forty-seven children were diagnosed with HIV infection during the study period. The number of HIV infected children increased from 5 during 1981-85, to 14 during 1986-90, and to 21 during the 1991-95 period. The majority (91.5%) of infections resulted from perinatal transmission. Six (12.8%) cases remained asymptomatic and 41 (87.2%) were symptomatic with 19(46.3%) presenting in infancy, while 22 (53.5%) presented post-infancy. The median age at diagnosis (class P-2) was 13 months. Generalized lymphadenopathy (47.5%), hepatosplenomegaly (40.0%), failure to thrive (27.5%), persistent recurrent diarrhoea (15.0%), oral candidiasis (37.5%), Pneumocystis carinii pneumonia (37.5%), lymphoid interstitial pneumonia (12.5%) and progressive neurological disease (10.0%) were common HIV related conditions. Two children developed non-hodgkin's lymphoma. The median age at death for 23 children was 12 months, whereas the median survival after diagnosis was 4 months. Mortality was higher among those diagnosed in infancy (73.7%) as compared to those diagnosed post-infancy (42.8%). Pneumocystis carinii pneumonia was the most common (65.2%) cause of death. Paediatric HIV infection is rising and contributes considerably to infant mortality. In this study, children took longer to be symptomatic when compared to other reports. However, once symptomatic, they died early.

AIDS-Related Opportunistic Infections↗
PubMed2000

Long-term followup of elderly donors in a live related renal transplant program.

PURPOSE: It is a concern that elderly donors may have increased risks in the perioperative period due to age related changes in various organ systems. Nephrosclerosis, atherosclerosis and low glomerular filtration rate may portend a poor graft outcome. We performed a study to determine function and outcome of kidneys from elderly donors. MATERIALS AND METHODS: A retrospective analysis of our live related transplant program from November 1989 to December 1998 revealed that 112 donors were older than 55 years (range 55 to 81). Of the recipients of these kidneys from elderly donors 98 had a followup of more than 2 years (group 1), and they were compared to a cohort of 87 patients whose kidney donors were younger than 45 years (group 2). Allograft function was evaluated by serum creatinine and differential glomerular filtration rate was determined by (99m)technetium diethylenetriamine pentaacetic acid renal scan. All donors were followed regularly. RESULTS: Mean donor age plus or minus standard deviation was 57.4 +/- 4.3 and 31.4 +/- 7.6 years in groups 1 and 2, respectively. Mean followup plus or minus standard deviation was 42.44 +/- 20.46 months in group 1 and 40.04 +/- 27.28 months in group 2. The 1-year graft survival rate was 91.84% and 88. 51%, and the 5-year graft survival rate was 72.72% and 75.13% in groups 1 and 2, respectively. Serum creatinine was 1.5 +/- 0.65 and 1.7 +/- 1.52 mg./dl. in group 1 and 1.4 +/- 0.55 and 1.5 +/- 1.41 mg. /dl. in group 2 at 1 year and last followup, respectively. Glomerular filtration rate was 37.2 +/- 11.2 and 37.3 +/- 10.7 ml. per minute in group 1 and it was 45.3 +/- 8.6 and 47.7 +/- 11.3 ml. per minute in group 2 at 1 year and last followup, respectively. Acute rejection rate was significantly higher in group 1 (42%) compared to group 2 (19%). Both groups were comparable in terms of infectious episodes, antihypertensive requirement and incidence of acute tubular necrosis. There was no added morbidity for elderly compared to younger donors. CONCLUSIONS: In view of acute donor shortage and if properly screened, elderly kidneys can be used without increasing the risk to donor or compromising graft outcome.

Adult↗
PubMed2000

Heat exposure study in the workplace in a glass manufacturing unit in India.

The heat exposure for working conditions in coastal areas of tropical and subtropical countries like India is a crucial factor in improved qualitative and quantitative production. The hot climate augments the heat exposure close to sources like furnaces. In the present work heat exposure to workers in glass manufacturing units in a coastal area of India has been assessed. The Wet Bulb Globe Temperature (WBGT), the Corrected Effective Temperature (CET) and Mean Radiant Temperature (MRT) were measured. The WBGT values much exceeded ACGIH TLVs. A revision of these standards to suit tropical and subtropical conditions is required. The recommended durations of work and rest have been estimated.

Environmental Monitoring↗
PubMed2000

Pulmonary infections in the adolescent with immunodeficiency.

Pulmonary infections in the immunocompromised adolescent are important causes of significant morbidity and mortality. Advances in the fields of chemotherapy, organ transplantation, and use of corticosteroid and immunosuppressive therapies have led to significant improvement in the outcome of patients with malignancy and a variety of other disorders. HIV infection has become a major additional cause of immune suppression. In turn, physicians are encountering growing numbers of patients with an impaired immune system presenting with respiratory and other infections. This article presents a brief review of defense mechanisms in the respiratory tract, selected conditions leading to impaired immune responses in the adolescent, specific pulmonary pathogens and their evaluation in the immunocompromised adolescent, and general considerations of the management of pulmonary infections in the immunocompromised adolescent. Infections of the upper respiratory tract and pulmonary infections seen in adolescents with cystic fibrosis are not discussed.

Adolescent↗
PubMed2000

Immobilization of hormones for drug targeting.

Biological active compounds such as insulin, heparin, progesterone and labeled-LH were entrapped in glutaraldehyde cross-linked bovine serum albumin (BSA) and human serum albumin (HAS) microspheres. Studies were carried out for their binding capacity and biodegradability using new proteolytic enzymes. Effects of proteolytic enzymes such as trypsin, chymotrypsin, papain and pronase-E on microspheres were studied in order to understand the biodegradability of the cross-linked proteins. It has been observed that labeled-LG was entrapped 60% in BSA and HAS microspheres. Labelled-LH-BSA, Labelled-LH-HAS and insulin microspheres were injected into mice and rabbits. It was observed that these cross-linked microspheres were biodegradable and the process appeared to be slow one, useful for sustained release of hormones. It was also observed that these albumin microspheres exhibit fluorescence at 495 nm.

Animals↗
PubMed2000

Graphically-enabled integration of bioinformatics tools allowing parallel execution.

Rapid analysis of large amounts of genomic data is of great biological as well as medical interest. This type of analysis will greatly benefit from the ability to rapidly assemble a set of related analysis programs and to exploit the power of parallel computing. TurboGenomics, which is a software package currently in its alpha-testing phase, allows integration of heterogeneous software components to be done graphically. In addition, the tool is capable of making the integrated components run in parallel. To demonstrate these abilities, we use the tool to develop a Web-based application that allows integrated access to a set of large-scale sequence data analysis programs used by a transposon-insertion based yeast genome project. We also contrast the differences in building such an application with and without using the TurboGenomics software.

Computational Biology↗
PubMed2000

cAMP increases the expression of human angiotensinogen gene through a combination of cyclic AMP responsive element binding protein and a liver specific transcription factor.

Angiotensinogen is the glycoprotein precursor of one of the most potent vasoactive hormones angiotensin-II which plays an important role in the regulation of blood pressure. We show here that the promoter activity of reporter constructs containing human angiotensinogen promoter is increased by cAMP treatment on transient transfection in HepG2 cells. We have identified a composite cAMP responsive element, located around 840 bases upstream from the transcriptional initiation site, in the promoter of human angiotensinogen gene. This element is recognized by members of CREB/ATF as well as C/EBP family of transcription factors. Another C/EBP binding site that is not recognized by CREB is located 10 bases upstream from this site. We show that co-transfection of CREB increases the promoter activity of reporter constructs containing human angiotensinogen gene promoter attached to the CAT gene. We also show that co-transfection of DBP (which is a member of C/EBP family of transcription factors) increases promoter activity of these reporter constructs.

Activating Transcription Factor 1↗
PubMed2000

Molecular signaling in pathogenicity and host recognition in smut fungi taking Karnal bunt as a model system.

Karnal bunt of wheat, incited by a phytopathogen Tilletia indica (Syn. Neovossia indica) is a floret infecting disease. In the floral tissues fungus proliferates and produces massive amount of black spores. In smut fungi, belonging to order Ustilaginales, communication between cells is necessary to regulate growth, differentiation and monokaryotic to dikaryotic transition during pathogenic and sexual development. Neighbouring cells are able to communicate with each other by direct cell to cell contact through plasma membrane bound signaling molecules or through formation of gap junctions and alternatively through secretion of chemical signals if cells are some distance away. Current research efforts toward understanding of pathogenic and sexual development in phytopathogenic fungi, offer a number of opportunities. These include the analysis of molecular signal(s) for direct contribution of sexual interactions to ability of smut and bunt pathogens to cause disease. These efforts will provide not only to explore the mechanisms of pathogenesis, but also to enhance knowledge of basic cellular biology of an economically important group of fungi.

Cell Communication↗
PubMed2000

Pre- and extra-marital heterosexual behaviour of an urban community in Rajasthan, India.

A study conducted among the teachers of senior secondary schools of a city in Rajasthan state to know the magnitude of pre- and extra-marital heterosexual practices and some related characteristics revealed that one third of unmarried and one fifth of married males had experienced pre-marital sex. The same for unmarried and married females was 11.8 per cent and 1.5 per cent, respectively. The prevalence of extra-marital heterosexual act among married males was 15.5 per cent. One out of ten married males reported to have had both pre- and extra-marital sex. A male having pre-marital sex was 15 times more likely to have extra-marital sex. Friends, acquaintances and relatives were the important sexual partners while role of commercial sex workers was negligible. The study reports that heterosexual act with person other than the legal spouse is very much prevalent among this group of middle class professionals. This situation is conducive for the spread of HIV infection among general population and may adversely influence the sexual attitudes of students. The study, therefore, suggests that, besides intensifying the health education on HIV/AIDS, serious considerations about the sexual behaviours of school teachers are needed.

Adult↗
PubMed2000

Metallothionein induced by cadmium or zinc inhibits lipid peroxidation in rats exposed to dimethylnitrosamine.

Dimethylnitrosamine (N-nitrosodimethyamine) is a potent inducer of microsomal lipid peroxidation in the liver and kidneys. The results of this study show that prior exposure of adult rats to cadmium or zinc antagonises the effect of dimethylnitrosamine on lipid peroxidation by inducing increased metallothionein synthesis. Increased concentration of reduced glutathione (GSH) in the liver and kidney of rats pre-treated with cadmium or zinc and exposed to dimethylnitrosamine suggests that metallothionein inhibits oxidative stress. The presented results have been corroborated by findings that exposure of adult rats to cadmium or zinc may activate genes for metallothionein and glutathione-S-transferase, the protective proteins against oxidative stress.

Animals↗
PubMed2000

Enhancement of seed oil content by expression of glycerol-3-phosphate acyltransferase genes.

Arabidopsis thaliana was transformed with a plastidial safflower glycerol-3-phosphate acyltransferase (GPAT) and an Escherichia coli GPAT. The genes were used directly and in modified forms with, as applicable, the plastidial targeting sequence removed, and with an endoplasmic reticulum targeting sequence added. Seeds of plants transformed using only the vector were indistinguishable in oil content from wild-type control plants. All other gene constructs increased seed oil content. The unmodified safflower gene (spgpat) produced oil increases ranging from 10 to 21%. On average, the greatest increase (+22%) was observed in seeds of transformants carrying the spgpat with the targeting peptide removed. The E. coli plsB gene increased seed oil content by an average of 15%.

Arabidopsis↗