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Biomedical subjects

A Kumar

Publications and source records attributed to A Kumar.

At least 181 records · Page 10Linked to original sources
PubMed2003

Protective role of certain chemicals against UV-B-induced damage in the nitrogen-fixing cyanobacterium, Nostoc muscorum.

The protective effects of L-cysteine, ascorbic acid, reduced glutathione, L-tryptophan, and sodium pyruvate against UV-B-induced damages were studied in the nitrogen-fixing cyanobacterium, Nostoc muscorum. When added to the culture suspension during UV-B treatment, these chemicals caused a significant protective effect on survival and growth of the organism. Sodium pyruvate conferred the strongest protection whereas the weakest effect was elicited by tryptophan. A 20 min exposure of a culture suspension to UV-B completely inactivated nitrogenase activity but the inactivation was strongly prevented by exogenous addition of ascorbic acid or reduced glutathione during UV-B exposure, and weakly prevented by pyruvate, cysteine and tryptophan. In vivo nitrate reductase activity was not completely lost even after 80 min of UV-B exposure, and addition of the test chemicals did not confer any significant protection to this enzyme. Whereas (14)CO(2) uptake was drastically inhibited (78% inhibition) by 30 min exposure to UV-B in the absence of any test chemical, about 76% activity remained when the UV-B exposure was given to cultures in the presence of ascorbic acid. These results suggest that the damaging effects of UV-B are substantially minimized by certain reducing agents, the protective effect being particularly strong on the O(2) sensitive enzyme, nitrogenase. Presence of these chemicals in their natural habitat or inside the cells of living organisms may partially protect/repair the damaging effects of UV-B radiation.

Ascorbic Acid↗
PubMed2003

Effect of lycopene on pre-eclampsia and intra-uterine growth retardation in primigravidas.

OBJECTIVES: To observe the effect of the antioxidant lycopene on the occurrence of pre-eclampsia and intrauterine growth retardation in primigravida women. METHODS: A total of 251 primigravida women were enrolled in this prospective, randomized controlled study in the second trimester. A total of 116 women were given oral lycopene (Group I) in a dose of 2 mg twice daily while 135 women were given a placebo (Group II) in the same dose until delivery. The criteria for recruitment included gestational age of 16-20 weeks, singleton pregnancy, absence of any medical complication and willingness on the part of the women to participate in the study. The women were followed-up until delivery for development of pre-eclampsia, mode of delivery and fetal outcome. RESULTS: The two groups were comparable in their maternal characteristics. Pre-eclampsia developed in significantly less women in the lycopene group than in the placebo group (8.6% vs. 17.7%, P=0.043 by chi-square test). Mean diastolic blood pressure was significantly higher in the placebo group (92.2+/-5.98 mmHg vs. 86.7+/-3.80 mmHg, P=0.012). Mean fetal weight was significantly higher in the lycopene group (2751.17+/-315.76 g vs. 2657+/-444.30 g, P=0.049). The incidence of intrauterine growth retardation was significantly lower in the lycopene group than in the placebo group (12% vs. 23.7%, P=0.033). CONCLUSIONS: The results of the present study suggest that the antioxidant lycopene reduces the development of pre-eclampsia and intrauterine growth retardation in primigravida women.

Adult↗
PubMed2003

In vitro effects of acellular milk on the bactericidal components of caprine polymorphonuclear neutrophils.

The effects of acellular milk on the activity of the microbicidal cationic enzymes of the polymorphonuclear cells of goats were studied in an attempt to explain the phenomenon by which PMN functions fail in mastitis. Assays were undertaken on the myeloperoxidase, lysozyme and elastase activities in a polymorphonuclear cell (PMN) lysate, both in the presence and absence of acellular milk from homologous species. There was a significant decrease (p < 0.05) in the activity of lysozyme, myeloperoxidase and elastase in the presence of acellular milk. Superoxide and H2O2 production following activation of caprine PMNs by lipopolysaccharide (LPS) was significantly reduced (p < 0.05) in the presence of acellular milk. Thus, the microbicidal function of PMNs is significantly impaired in the presence of acellular milk and this may contribute to the development of mastitis in dairy animals.

Animals↗
PubMed2003

Mini incision live donor nephrectomy: an optimal approach for the developing countries.

OBJECTIVE: Laparoscopic donor nephrectomy (LD) is rapidly gaining popularity, however, this may not be affordable by donors in many developing countries because of its high cost. We describe our mini flank incision (MD) donor nephrectomy technique and its outcome. METHODS: A 7-10-cm subcostal rib sparing transverse incision was given 2 cm lateral to the tip of the 12th rib, towards the lateral border of rectus muscle. All dissections were performed with help of long retractors and instruments, vessels were transfixed and cut. In last 45 cases, vessels were clipped with Liga or Weck clips. Donors and recipients outcome was analysed. RESULT: From January 2000 to December 2002 a total of 148 patients underwent donor nephrectomy by mini incision technique. Mean patient age was 44.8 +/- 7.3 yr (range 20-70 yr). Nephrectomies were performed in 115 patients on the left side and in 33 cases on the right side. The mean incision length was 9.1 +/- 1.8 cm (range 7-10 cm). Mean operative time was 105 +/- 10.5 min (70-130 min). Mean analgesic (Tramadol) requirement was 205 +/- 52 mg; postoperative hospital stay was 2.2 +/- 0.5 d. Twelve per cent patients developed fever and 4% had superficial wound infection in postoperative period. Three patients required blood transfusion. Mean convalescence period was 22 +/- 2.8 d. CONCLUSION: Extrapleural, extraperitoneal, subcostal mini incisions live donor nephrectomy is a relatively safe procedure with low morbidity. This technique has a shorter hospital stay, early convalescence and better cosmesis. It is cost-effective and is an ideal substitute for the developing country.

Adult↗
PubMed2003

Dysregulated expression of IFN-gamma and IL-10 and impaired IFN-gamma-mediated responses at different disease stages in patients with genital herpes simplex virus-2 infection.

Cell-mediated T-helper type-1 (Th1) responses play a vital role in the immunopathogenesis of genital infections caused by herpes simplex virus 2 (HSV-2). We investigated the role of Th responses in HSV-2 infection at different disease stages by analysing the production of Th cytokines in HSV-stimulated peripheral blood mononuclear cells (PBMCs). IFN-gamma production decreased over time following a recurrence, whereas levels of IL-10, and to a lesser extent IL-2, remained elevated during this period. In addition, PBMCs from asymptomatic seropositive individuals produced high levels of IFN-gamma and low levels of IL-10, in contrast to individuals with a history of genital ulcers. Following a recurrence, virus copy number in the genital lesions decreased progressively over time, in a manner similar to IFN-gamma production by HSV-2-stimulated PBMCs. Enhanced production of IFN-gamma may modulate HSV replication and B7 expression on monocytic cells of HSV-infected individuals. In contrast to seronegative controls, IFN-gamma failed to enhance B7 expression on monocytic cells of HSV-infected individuals. In addition, monocytic cells from HSV-2-infected individuals with recurrent disease supported greater HSV replication than did those of HSV-infected asymptomatic individuals or seronegative controls. Furthermore, addition of IFN-gamma resulted in enhanced HSV replication in monocytic cells of HSV-infected individuals with recurrent disease, in contrast to the inhibition observed in HSV-seropositive asymptomatic individuals and seronegative controls. Taken together, our results suggest that dysregulated production of IFN-gamma at different disease stages and the impaired ability of monocytic cells to respond to IFN-gamma may play a role in the pathogenesis of recurrent genital herpes disease.

Case-Control Studies↗
PubMed2003

Substitution urethroplasty for anterior urethral strictures: a critical appraisal of various techniques.

OBJECTIVE: To retrospectively compare the outcome of various techniques of substitution urethroplasty. PATIENTS AND METHODS: Between 1989 and 2000, 109 patients (mean age 39.5 years) underwent substitution urethroplasty for recurrent anterior urethral strictures. Between 1989 and 1995 the procedure was by ventral placement of free grafts (bladder mucosa, buccal mucosa, penile skin) or penile skin flaps. From 1995 onwards the flaps and grafts (buccal mucosa) were applied either ventrally or dorsally. Stricture recurrence and the complications associated with each technique were compared. RESULTS: Ventral onlay repairs were associated with a higher incidence of complications than dorsal repairs, e.g. postvoid dribbling (39% vs 23%, P = 0.01), ejaculatory dysfunction (20% vs 5%, P = 0.03) and flap/graft pseudo-diverticulum or out-pouching (26% vs 2.6%, P = 0.01). Superficial penile skin necrosis was significantly more common with the use of penile skin flaps than with free grafts. There was no significant difference in stricture recurrence, erectile dysfunction and residual penile deformity among the various techniques. CONCLUSIONS: Dorsal free graft/flap onlay urethroplasty gives better results than ventrally placed free grafts/flaps. Dorsal onlay buccal mucosal urethroplasty is a versatile procedure and associated with fewer complications than other substitution methods.

Adolescent↗
PubMed2003

Effect of phenolic monomers on biomass and hydrolytic enzyme activities of an anaerobic fungus isolated from wild nil gai (Baselophus tragocamelus).

AIMS: To test the anaerobic fungus, Piromyces sp. FNG5, for its tolerance to phenolic monomers released in the rumen by degradation of lignocellulosic poor-quality feeds. METHODS AND RESULTS: Effects of phenolic monomers on biomass and fibrolytic enzyme activities of a pure culture of lignocellulolytic anaerobic fungus (Piromyces sp. FNG5) isolated from faeces of wild nil gai (blue bull, Baselophus tragocamelus) were evaluated. There was a reduction in fungal biomass at 1 mm concentration of catechol with complete inhibition at 10 mm. p-Coumaric acid caused a reduction in biomass at 10 mm and no growth was observed above 20 mm concentration. The fungal isolate could tolerate up to 5 mm of ferulic acid without any reduction in biomass level, and was able to grow to some extent up to the highest level of ferulic acid tested (20 mm). Vanillic acid had no effect on biomass of the fungus even up to 50 mm level. The phenolic monomers varied in their potential to inhibit the secretion of carboxymethyl cellulase, xylanase, beta-glucosidase and acetyl esterase activities with catechol being the most inhibitory and vanillic acid being the least inhibitory. After 14 days of incubation, 38.49-65.14%p-Coumaric acid, 65.22-74.10% ferulic acid and 34.13-66.78% vanillic acid disappeared from the medium under anaerobic conditions. CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: It is concluded that the anaerobic fungus Piromyces sp. FNG5 is tolerant to phenolic monomers and has ability to degrade them. Therefore, such anaerobic fungi may play an important role in fibre degradation in the rumen.

Animals↗
PubMed2003

Varying role of vitamin D deficiency in the etiology of rickets in young children vs. adolescents in northern India.

The relative importance of calcium vs. vitamin D deficiency in the etiology of nutritional rickets in the tropics may be different in children compared with adolescents. We studied calcium intake, sun exposure, serum alkaline phosphatase, and 25 hydroxyvitamin D in 24 children and 16 adolescents with rickets/osteomalacia. The values were compared with those obtained in control subjects (34 children and 19 adolescents). We found that young children with rickets had lower calcium intake compared with controls (285 +/- 113 vs. 404 +/- 149 mg/day, p < 0.01), but similar sun exposure (55 +/- 28 vs. 56 +/- 23 min x m2/day) and 25 hydroxyvitamin D (49 +/- 38 vs. 61 +/- 36 nmol/l). Sixteen of 24 children with rickets had 25 hydroxyvitamin D above the rachitic range (> 25 nmol/l), in contrast to one of 16 adolescents. Adolescent patients had low calcium intake vs. controls (305 +/- 196 vs. 762 +/- 183 mg, p < 0.001), and lower sunshine exposure (16 +/- 15 vs. 27 +/- 17 min x m2/day, p < 0.01) and serum 25 hydroxyvitamin D (12.6 +/- 7.1 vs. 46 +/- 45.4 nmol/l, p < 0.001). The odds ratio for developing rickets with a daily calcium intake below 300 mg was 4.8 (95 per cent CI, 1.9 - 12.4, p = 0.001). Subjects with rickets were randomized to receive 1 g calcium daily, with or without vitamin D. Children showed complete healing in 3 months, whether they received calcium alone or with vitamin D. Adolescents showed no response to calcium alone, but had complete healing with calcium and vitamin D in 3-9 months (mean 5.3 months). Thus deficient calcium intake is universal among children and adolescents with rickets/osteomalacia. Inadequate sun exposure and vitamin D deficiency are important in the etiology of adolescent osteomalacia.

Adolescent↗
PubMed2003

Radioiodine lobar ablation as an alternative to completion thyroidectomy in patients with differentiated thyroid cancer.

This study seeks to evaluate the role of radioiodine in the ablation of the remaining thyroid lobe, following a histopathological diagnosis of minimally invasive follicular carcinoma or papillary carcinoma of > or =1.5 cm size in patients undergoing hemithyroidectomy. There were 93 patients (69 females and 24 males) with an average age of 37.3+/-12.5 years (range, 16-70 years) and a mean follow-up duration of 46 months. Sixty-six of the patients had papillary cancer and remaining 27 had follicular thyroid cancer. The mean 24 h radioiodine neck uptake at the first visit was 17.2+/-7.3% (4.4-34%). In view of the large amount of thyroid tissue to be ablated, which may produce radiation induced thyroiditis, low doses of radioiodine (15-60 mCi) were administered to the patients. The patients were evaluated 6 months after radioiodine therapy with a 131I whole-body scan and 48 h radioiodine neck uptake, and a thyroglobulin assay after 4-6 weeks of levothyroxine withdrawal. The thyroid lobe was completely ablated in 53 patients (56.9%) after one dose of I and the remaining patients had partial thyroid ablation, with the mean radioiodine neck uptake being reduced to 3.1+/-2.4%. The mean first dose of 131I was 31.8+/-11.7 mCi; the estimated mean absorbed dose was 251.3+/-149.3 Gy (range, 120-790 Gy). Around 30% patients, in each of whom a remnant thyroid lobe was ablated with a single dose of radioiodine, received < or =200 Gy. The cumulative ablation rate was 92.1% after two doses of 131I. Only seven patients needed a third dose of 131I. In our cohort, 15 patients (16.1%) complained of throat discomfort and neck pain. All of them were managed with mild analgesics except three patients who needed additional oral prednisolone for 7-10 days to overcome neck oedema. We conclude that, although completion thyroidectomy remains the standard treatment after hemithyroidectomy in cases of differentiated thyroid cancer, radioiodine ablation of an intact thyroid lobe is possible and it can be achieved with much smaller doses of radioiodine than previously believed. Lobar ablation is an attractive alternative to surgery for those who refuse to undergo completion thyroidectomy or had complications during initial surgery. However, the long-term outcome in this subset of patients remains to be determined.

Adult↗