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Biomedical subjects

B Kumar

Publications and source records attributed to B Kumar.

At least 37 records · Page 2Linked to original sources
PubMed2004

Interspecific hybridization of Trifolium alexandrinum with T. constantinopolitanum using embryo rescue.

The embryo rescue technique was successfully used to raise hybrids between Trifolium alexandrinum and T. constantinopolitanum. As a result of its narrow genetic base, genetic improvement in Egyptian clover (syn. Berseem; T. alexandrinum), an important fodder crop in tropical and subtropical countries, is hampered, thereby making it imperative to introduce alien genes from related species. In a conventional interspecific hybridization program, hybrids could not be raised due to post-fertilization barriers. Of the several combinations tried, pollination 2 days after emasculation was found to be the best. Globular embryos were observed 5-7 days after pollination (DAP), followed by heart-shaped embryos 10-12 DAP. Embryos excised at the heart-shaped stage responded well to EC3 culture medium. Of 612 crosses, 33 healthy embryos could be excised and cultured on EC3 medium. The plumule emerged 8-12 days following inoculation. The embryo-rescued plants were hardened, inoculated with Rhizobium and transferred to the field. The hybrids showed intermediate morphological features with reduced pollen fertility (55-65%) and a chromosomal complement of 2n = 16. Biochemical characterization using isozymes confirmed hybridity.

Crosses, Genetic↗
PubMed2004

Efficacy of various amendments for amelioration of fly-ash toxicity: growth performance and metal composition of Cassia siamea Lamk.

Plants of Cassia siamea Lamk were grown in garden soil (control), fly-ash (100%) and fly-ash amended by various ameliorants (cowdung manure, press-mud, garden soil; 1:1, w/w). The plants survived in fly-ash (100%) though their growth was less in comparison to the treatments. Fly-ash+press-mud (1:1, w/w) proved to be the best combination as growth (total biomass, leaf number, photosynthetic area, total chlorophyll and protein) was significantly high in this treatment followed by cowdung manure and garden soil. Leaves and roots accumulated significant amount of Cu, Zn, Ni and and Fe. However, the concentration of all the metals was more in roots than leaves except Ni. Although, fly-ash contains high amount of metals but the metal uptake was more in the plants grown in fly-ash+press-mud mixture. Inspite of high metal availability in fly-ash and press-mud mixture, plant growth was good. This might be attributed to the some metal detoxification mechanism active in this treatment. The present study concluded that C. siamea seems to be a suitable plant for developing a vegetation cover on fly-ash dumps.

Analysis of Variance↗
PubMed2004

Cutaneous leishmaniasis in red kangaroos: isolation and characterisation of the causative organisms.

This is the first report of cutaneous leishmaniasis in kangaroos where infection was acquired within Australia. The diagnosis is based on the clinical criteria used for humans, the lesion histopathology, the detection and isolation of parasites from the lesions, and the analysis of the small subunit ribosomal RNA genes using the polymerase chain reaction. Despite a clear indication that the parasites belong to the genus Leishmania, no assignation to a known Leishmania species could be made using these or other less conserved genetic loci such as the non-transcribed spacer of the mini-exon repeat. As is the case in humans, some but not all animals harbouring lesions had antibodies to the isolated parasites or to several other Leishmania species. The isolated parasites displayed two well characterised Leishmania glycoconjugates, the lipophosphoglycan and proteophosphoglycan. They were infectious for mouse macrophages in vitro and established long-term infection at 33 degrees C but not at 37 degrees C. Our findings raise the possibility of transmission to humans, which may be unrecognised and suggest the possibility that imported species of Leishmania could become endemic in Australia.

Animals↗
PubMed2004

Dissociation of disease susceptibility, inflammation and cytokine profile in lmr1/2 congenic mice infected with Leishmania major.

Severity of disease caused by Leishmania major depends on the genetics of the host. Early induction of T helper cell type 1 (Th1)-type responses in resistant C57BL/6 mice and T helper cell type 2 (Th2) in susceptible BALB/c mice is thought to determine cure or disease respectively. We have mapped three loci that confer susceptibility or resistance upon congenic mice on the C57BL/6 or BALB/c backgrounds. Here we examine the histopathology and production of interleukin 4 (IL-4) and interferon gamma (IFN-gamma) in the skin and draining lymph nodes in the congenic and parental mice. We show an evolving granuloma with a staged infiltration of inflammatory cells, but no difference between the groups. As an indication of an early-polarised Th1/Th2 response we measured IFN-gamma and IL-4 in the lymph nodes and found no difference between any of the mice during the first 48 h. During infection, the level of IL-4 correlated with the lesion size, indicating that IL-4 reflects the disease severity rather than controls it. Considering this effect, B6.C(lmr1,lmr2) mice had similar cytokine levels to the parental C57BL/6 mice despite increased susceptibility and C.B6(lmr1,lmr2) were similar to BALB/c despite increased resistance. We conclude that the lmr loci affect disease severity by a mechanism independent of conventional helper T-cell responses.

Animals↗
PubMed2004

Use of RAPD-PCR for genetic analysis of Nicobari fowl of Andamans.

1. The present study was conducted to estimate genetic relatedness among Nicobari fowls (Brown, Black and White) and an exotic bird (White Leghorn) using random amplified polymorphic DNA (RAPD) polymorphism. 2. A total of 25 decamer primers were screened among all the breeds of which 24 primers amplified the genomic DNA, generating 2000 to 200 bp bands. Ten primers generated reproducible and distinct RAPD profiles and were used for further analysis. 3. A total of 94 bands were amplified and 30 polymorphic bands (32%) were produced. The number of polymorphic loci ranged from 1 to 5 with an average of 3.0. 4. Among the native breeds Brown Nicobari showed higher genetic similarity (0.85) than Black Nicobari (0.80) and White Nicobari fowl (0.82). 5. Brown Nicobari showed high genetic similarity with Black Nicobari (0.87 +/- 0.029); least similarity was between White Nicobari and White Leghorn (0.77 +/- 0.028). 6. The RAPD profile of all Nicobari fowls on amplification with the primers PBG5 and PBA12 showed specific bands of molecular size 1050 and 785 bp, respectively. 7. The native breeds showed the least genetic distance with each other while White Leghorn appeared to be most distant from the native breeds.

Animals↗
PubMed2004

Comparative efficacy of cetirizine and fexofenadine in the treatment of chronic idiopathic urticaria.

OBJECTIVES: Antihistamines are the first line of therapy for chronic idiopathic urticaria (CIU). The present study was designed considering the lack of reports comparing the efficacy and safety of commonly prescribed cetirizine and fexofenadine in the treatment of CIU. METHODS: A total of 116 patients, aged 17 to 65 years, with CIU (urticarial wheals for at least two days per week for six consecutive weeks before entry) were enrolled in this randomised double-blind study. Study period was 28 days with patient visits on days 14 and 28 for investigator evaluation of the clinical response. Patient evaluation was on the basis of an analogue scale. Final response to treatment was judged as symptom free, partial improvement, and no improvement. RESULTS: Ninety-seven patients (52 cetirizine, 45 fexofenadine) completed the study. The response to treatment in both the groups at the end of treatment period was as follows; symptom free [cetirizine 27(51.9%), fexofenadine 2(4.4%)], partial improvement [cetirizine 19(36.5%), fexofenadine 19(42.2%)], no improvement [cetirizine 6(11.5%), fexofenadine 24(53.3%)]. Side effects noted were mild with no significant difference between the two. CONCLUSION: Cetirizine seems to have therapeutic advantage over fexofenadine in the treatment of CIU.

Adolescent↗
PubMed2004

Treatment of angiolymphoid hyperplasia with eosinophilia with the carbon dioxide laser.

Angiolymphoid hyperplasia with eosinophilia (ALHE) is an uncommon, idiopathic condition that presents with isolated or grouped plaques or nodules in the periauricular region, forehead, or scalp. ALHE is marked by a proliferation of blood vessels with distinctive large endothelial cells accompanied by a characteristic inflammatory infiltrate that includes eosinophils. The lesion is benign but may be persistent and difficult to eradicate. Various therapeutic modalities that have been tried for its treatment include intralesional and oral corticosteroids, cryotherapy, oral retinoids, vinblastine, surgical excision, laser therapy, and INFalpha2a. We report two cases with this rare condition: one patient, treated with cryotherapy, did not improve, while the second patient was successfully treated with the CO(2) laser.

Adult↗
PubMed2004

Erythema nodosum and antitubercular therapy.

OBJECTIVE: To establish the efficacy of antitubercular therapy in patients with erythema nodosum with a highly positive Mantoux test. METHODS: A retrospective analysis of all patients diagnosed with idiopathic erythema nodosum with a highly positive Mantoux reaction between 1988 and 2001 was undertaken. In the absence of any other clinical or investigative evidence of active tuberculosis they were treated with antitubercular therapy. RESULTS: Out of a total of 52 patients diagnosed with idiopathic erythema nodosum with a strongly positive Mantoux test (average of 19 mm), data could be analyzed in only 47 patients. After treatment with antitubercular drugs, new lesions stopped appearing in 45 patients within 6-8 weeks and subsided in two. The therapy was well tolerated except for jaundice in one patient and transient urticarial lesions in another. CONCLUSIONS: Antitubercular therapy definitely has a role in the management of patients with erythema nodosum, even in the absence of a detectable focus of tubercular infection, especially in regions where tuberculosis is endemic.

Antitubercular Agents↗
PubMed2004

Single-dose fluconazole versus itraconazole in pityriasis versicolor.

BACKGROUND: The new antifungal triazoles itraconazole and fluconazole have revolutionized the treatment of pityriasis versicolor. Both drugs have shown promising results in different dose schedules. OBJECTIVE: To compare the efficacy and safety of single oral dose treatment with fluconazole versus itraconazole in patients with pityriasis versicolor. METHODS: A total of 40 patients with pityriasis versicolor were allocated randomly to group A and group B. A single dose of fluconazole (400 mg) or itraconazole (400 mg) was given orally to group A or group B patients, respectively. Patients were assessed mycologically by KOH and culture. Culture was done from lesional and perilesional skin to quantify growth and to observe the effect of these drugs and the persistence/reappearance of the fungus in relation to relapse at 2 and 8 weeks. Relapse was defined as reappearance or worsening of clinical signs and symptoms or positive KOH/culture after initial improvement. RESULTS: Thirteen (65%) patients in the fluconazole group and 4 (20%) patients in the itraconazole group became culture negative at the end of 8 weeks. Relapse was found to be higher in the itraconazole group compared to the fluconazole group (60 vs. 35%). A direct correlation was found between the relapse rate and positivity of perilesional skin for Malassezia furfur. CONCLUSION: In the same dosing, fluconazole was found to be more effective than itraconazole; however, both drugs were found to be safe.

Administration, Oral↗
PubMed2003

Effect of extended perioperative antibiotic prophylaxis on intravascular catheter colonization and infection in cardiothoracic surgery patients.

Intravascular catheter-related infections (CRI) account for one third of nosocomial bloodstream infections in England. UK Department of Health guidelines state that antibiotic prophylaxis is not required during placement, or use of, central venous catheters, to prevent CRI. However, some clinicians continue to use antibiotics in an attempt to prevent CRI. We investigated the effect of extended routine perioperative antibiotic prophylaxis in cardiothoracic patients on rates of intravascular catheter (IVC) colonization and infection. Investigations were undertaken in patients undergoing uncomplicated cardiothoracic surgery during July 2001-February 2002. Patients who received three doses of cefuroxime as perioperative prophylaxis were compared with those who received extended cefuroxime prophylaxis until the IVC was removed. Patients were not randomized into groups, but received the different prophylaxis regimens according to the usual practice of the consultant cardiothoracic surgeon. A roll tip method was used to determine IVC colonization. Of 191 patients who fulfilled the inclusion criteria, 12 were excluded because data were incomplete. One hundred and forty-six patients received routine prophylaxis, and 33 prophylaxis until the IVC was removed. Twenty-three out of 146 (16%) IVCs in the 'routine' group and four out of 33 (12%) in the 'extended' group became colonized; no IVC-related bloodstream infections occurred during the survey. The duration of IVC placement and the types of operation performed in the two groups were not significantly different (P > 0.05). In routine cardiothoracic surgery patients, extending routine perioperative antibiotic prophylaxis until all IVCs have been removed does not influence rates of IVC colonization.

Anti-Bacterial Agents↗
PubMed2003

Tandem mass spectra of ammonium ion, metal ion and ligated metal ion adducts of acyclic sugar derivatives.

The tandem mass (MS/MS) spectra of ammonium ion, metal ion and ligated metal ion adducts of chain-extended acyclic nitro-containing deoxyglucose and deoxygalactose derivatives have been studied. The ammonium adducts fragment primarily by elimination of ammonia followed by acetic acid, thus not giving much structural information. In contrast, cationization of these compounds by metal ions and ligated metal ions gave structurally informative and useful fragment ions on MS/MS. The metal ions and ligated metal ions play an important role in controlling and directing fragmentation. Retro-aldol fragmentation is facilitated by metal ions such as Li(+), Na(+), Ag(+) and Cu(+), whereas the adducts with higher alkali metal ions such as Rb(+) and Cs(+) fragment to give only the corresponding metal ions. The divalent metal ions such as Cu(2+) and Ba(2+) also induce retro-aldol fragmentation. However, the charge is carried by the aldehyde fragment in the case of Cu(2+) adducts, whereas the nitroalkane fragment carries the charge in the case of Ba(2+) adducts. Ligated metal ions such as ZnCl(+), CuCl(+), InCl(2) (+) and BaCl(+) also behave similarly and induce retro-aldol fragmentation in these acyclic sugars. Both the metal ion and ligated metal ion adducts can fragment by elimination of metal-containing neutral molecules.

Acetic Acid↗
PubMed2003

Reduced apoptosis by pentoxiphylline among patients with HIV infection.

BACKGROUND: Apoptosis is a significant cause of CD4(+) T cell death. Caspase 8 (FLICE) is involved in apoptosis mediated by Fas and p55 tumor necrosis factor (TNF) receptor ligation. It is also partially mediated by interleukin-1beta (IL-1beta)-converting enzyme (ICE; caspase 1). We and others have shown that pentoxiphylline inhibits TNF-alpha. We used it among patients with HIV infection to determine if 24 weeks of therapy altered the levels of caspase 1 and caspase 8. PATIENTS AND METHODS: Nineteen HIV-infected patients having no opportunistic infection at the time of recruitment were administered pentoxiphylline 400 mg thrice daily for 24 weeks. Caspase levels were measured using a single-step ELISA using commercially available monoclonal antibodies against caspase 1 and caspase 8. RESULTS: Mean CD4 counts of the patients were 202.6+/-111.6 (/mm(3)). Mean OD value of caspase 1 among patients before therapy was 0.302+/-0.197 and was higher than that of controls (0.287+/-0.064), but this was not statistically significant. Following 24 weeks of therapy with pentoxiphylline, the OD value declined significantly to 0.164+/-0.028 among patients (p<0.001). Mean OD value of caspase 8 among patients prior to therapy was 0.927+/-0.249. This was significantly higher than that of controls, whose level was 0.0074+/-0.004 (p<0.001). Following 24 weeks of therapy with pentoxiphylline, the OD value declined to 0.199+/-0.064 among patients and this was significantly lower than the value at the start of treatment (p<0.001). CONCLUSION: Therapy with pentoxiphylline for 24 weeks is associated with a decline in the levels of caspase 1 and caspase 8. Since the drug is known to produce TNF inhibition, this might result in reduced apoptosis and an improved CD4 lymphocyte survival.

Adult↗