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Biomedical subjects

P Kumar

Publications and source records attributed to P Kumar.

At least 325 records · Page 18Linked to original sources
PubMed1997

Effect of the potassium channel opener ZM260384 on skeletal muscle function during restricted blood flow in the anaesthetized cat.

The aim of the present experiment was to determine whether the potassium channel opener 2-(2,2-bis(difluoromethyl)-6-nitro-3,4-dihydro-2H-1, 4-benzoxazine-4-yl)pyridine-N-oxide (ZM260384) was capable of accelerating the decline in skeletal muscle function during restricted blood flow in vivo. Cats (3.0-4.5 kg body weight) were anaesthetized with alphaxalone-alphadalone and breathed spontaneously following tracheotomy. Isometric tension was measured in the extensor digitorum longus-anterior tibialis (EDL-TA) muscle group. Ischaemia was induced by perfusing the hindlimb with the animal's own blood at a rate of 12.5 ml min-1 using a roller pump and stimulating the common peroneal nerve to induce repetitive submaximal tetanic contractions in the EDL-TA. The number of stimulation voltage increments required each minute to maintain a constant level of submaximal mechanical output and the time to exhaustion were used as indices of the rate of tension decline. The rate of tension decline in the ischaemic EDL-TA in the presence of ZM260384 at 3 mg kg-1, a maximally hypotensive dose predicted to be within the dose range required to exert direct effects on skeletal muscle, was measured and compared with the rate of tension decline in the presence of ZM260384 at 0.03 mg kg-1, also maximally hypotensive dose but below the predicted dose range for skeletal muscle effects. The number of voltage increments per minute was 1.93 +/- 0.07 and 1.48 +/- 0.14 (P < 0.05) in the presence of 3 and 0.03 mg kg-1 ZM260384, respectively. Time to exhaustion was 17.5 +/- 4.2 and 7.2 +/- 0.8 min (P < 0.05) in the presence of 3 and 0.03 mg kg-1 ZM260384, respectively. Given that there was no difference between these two groups in any haemodynamic variable measured, the results of the present study suggest that ZM260384 (3 mg kg-1) increases the rate of isometric force loss in ischemic skeletal muscle in vivo.

Anesthesia↗
PubMed1997

Isolation of Cryptococcus neoformans var. gattii from Eucalyptus camaldulensis in India.

Cryptococcus neoformans var. gattii has an ecological association with five Eucalyptus species: E. blakelyi, E. camaldulensis, E. gomphocephala, E. rudis, and E. tereticornis. After human infections due to C. neoformans var. gattii were diagnosed in the states of Punjab, Himachal Pradesh, and Karnataka, India, a study was undertaken to investigate the association of C. neoformans var. gattii with Indian eucalypts, especially in the state of Punjab. A total of 696 specimens collected from E. camaldulensis, E. citriodora and E. tereticornis (hybrid) trees were examined for the presence of C. neoformans var. gattii. Flowers from two trees of E. camaldulensis in the Chak Sarkar forest and one from the village of Periana near the Ferozepur area yielded five isolates of C. neoformans var. gattii. The origin of the trees could be traced to Australia, thus providing evidence that the distribution of E. camaldulensis correlated with the distribution of human cryptococcosis cases caused by C. neoformans var. gattii in northern India.

Animals↗
PubMed1997

Late reversal reaction after 10 years of adequately treated leprosy.

Differentiation between a relapse or late reversal reaction following completion of regular drug therapy in patients with leprosy is often difficult, though it has definite therapeutic implications. The present case documents a late reversal reaction occurring an unusually long time after the completion of multi-drug therapy.

Adult↗
PubMed1997

Renal artery stenosis in aortoarteritis: spectrum of disease in children and adults.

Nonspecific aortoarteritis is the commonest cause of renovascular hypertension (RVH) accounting for 87% of the patients in the present study. We compared the clinical and radiographic features and outcome in children (n = 16) and adult (n = 24) patients with aortoarteritis. Children have a shorter duration of disease and present more commonly with constitutional symptoms. All the patients were hypertensive; however, malignant hypertension and hypertensive encephalopathy were more common in children. Abdominal bruit and asymmetry of pulses were present only in 75 and 35% of the patients, respectively. Asymmetric kidney size on ultrasound was present in 15 of 24 adults, whereas 9 of 16 children had equal sized kidneys. Captopril renography had a better sensitivity for detection of RVH in children (13 of 16 in children vs. 12 of 24 in adults showing positive results). On intra-arterial digital substraction angiography, abdominal aortic involvement was invariable, whereas the thoracic aorta was involved less frequently in both age groups. Angiographic scores for the severity of vascular involvement was significantly lesser in children (6.87+/-4.8) as compared to adults (11.32+/-4.5). Thirteen of the 15 children were found suitable for revascularization, whereas 12 of 24 adults were not considered for revascularization as their kidneys were small and contributed to less than 10% of total function. Six of the adult patients underwent nephrectomy for the control of blood pressure. Results of angioplasty were also better in children than adults. We conclude that children present earlier with less severe vascular disease and respond better to revascularization, as compared to adults.

Adolescent↗
PubMed1997

Role of preoperative donor-specific transfusion and cyclosporine in haplo-identical living related renal transplant recipients.

A prospective randomized trial of use of donor-specific transfusion and cyclosporine given 24 h before operation was performed in living related renal transplant recipients. The benefits, disadvantages and effect on graft and patient outcome was analyzed. Cyclosporine was started 72 h before operation and 48 h before donor-specific transfusion (DST). Fifteen patients received DST while another 15 age- and sex-matched living related renal allograft recipients on similar immunosuppression served as controls. Patient and donor demographics were similar in the two groups. The DST group had significantly fewer rejection episodes than the control group (0.26 vs. 1.1 rejection episode per patient, p < 0.01). There were fewer episodes of acute rejection in the first 3 months posttransplant in the DST group. Hyperresponder recipients (as tested by mixed lymphocyte cultures) also benefitted by DST which significantly reduced the number of acute rejection episodes (0.25 vs. 1 episode per hyperresponder patient, DST vs. control, p < 0.05). The need for dialysis, incidence of infections and other complications were similar in the two groups. Graft function at 3, 6, 9 and 12 months after transplant was significantly better in the DST group (p < 0.05). Graft survival at 1 year in DST group (85.5%) was not statistically different than control (74.8%). In conclusion, DST and cyclosporine given 24 h before live related renal transplantation is effective in improving graft function and reducing the number of acute rejection episodes which could have a beneficial effect on long-term graft survival.

Acute Disease↗
PubMed1997

Vasectomy-induced superoxide dismutase inactivation in the male reproductive tract of rat: a prerequisite for spermatic granuloma formation.

Post vasectomy spermatic granuloma formation is considered as a favourable development for vasectomized subjects as it maintains physiological hydrostatic pressure within the male reproductive tract. But, the 'state of the art' of the formation of granuloma after vasectomy is not well defined. The present study reveals a link between the postvasectomy free radical status of the male tract and spermatic granuloma formation after vasectomy. A surge in the rate of ascorbyl radical production, directly correlated with oxyradical stress and an abrupt fall in superoxide dismutase activity in the granuloma, indicates 'switching on' of a free radical-dependent machinery for the formation of granuloma after vasectomy.

Animals↗
PubMed1997

A putative role for platelet-derived growth factor in angiogenesis and neuroprotection after ischemic stroke in humans.

BACKGROUND AND PURPOSE: Growth factors control two important processes in infarcted tissue, ie, angiogenesis and gliosis. We recently reported that transforming growth factor-beta1 (TGF-beta1) might be involved in angiogenesis after ischemic stroke in humans; here we present data of an extensive study on platelet-derived growth factor (PDGF) and its receptors. METHODS: We studied brain samples from patients who suffered from ischemic stroke for the expression of mRNA encoding PDGF-A, PDGF-B, and PDGF receptors (PDGF-R). Proteins were examined by Western blotting and immunohistochemistry using the antibodies to PDGF-AB, PDGF-BB, PDGF-R alpha, and PDGF-R beta. RESULTS: At the mRNA level, PDGF-A and PDGF-B were expressed mainly in neurons in penumbra. PDGF-R mRNA was strongly expressed in some astrocytes but mainly in type III/IV neurons in infarct and penumbra. The least expression was seen in the contralateral hemisphere (P<.001). In contrast, both PDGF-AB and PDGF-BB immunoreactive products were present in most cell types: PDGF-R alpha and PDGF-R beta mainly on neurons, and PDGF-R beta on some endothelial cells, with less staining of all the isoforms in the contralateral hemisphere. On Western blots, PDGF-AB and -BB were expressed more within white matter than gray matter of infarct/penumbra, whereas both isoforms of receptor were expressed mainly in gray matter compared with contralateral hemisphere. There was no or very weak expression of the receptor in white matter. CONCLUSIONS: PDGF proteins are highly expressed in white matter, suggesting that PDGF may exert its function in white matter participating either in regeneration of damaged axons or in glial scar formation. PDGF-BB and its receptor expressed on microvessel endothelial cells might be involved in angiogenesis after stroke. Thus, PDGF is likely to be angiogenic and neuroprotective in stroke.

Aged↗
PubMed1997

The role of thoracic radiotherapy in the management of limited-stage small cell lung cancer: past, present, and future.

The role of thoracic radiation therapy in the management of limited-stage small cell lung cancer (SCLC) is reviewed. Although chest irradiation has been used to treat SCLC for over four decades, its standard role in the management of limited-stage disease was established only during the last decade. Multiple prospective randomized trials have shown that the addition of thoracic radiation therapy to chemotherapy usually halves local failure rates, from >60% with chemotherapy alone to about 30% with chemoradiation therapy. Additionally, survival at 3 years is also improved by 50%, from 10% with chemotherapy alone to about 15% with chemoradiation therapy. However, issues relating to the timing, volume (ie, prechemotherapy vs postchemotherapy), and the dose fractionation scheme of thoracic radiation therapy in the treatment of limited-stage SCLC still remain unresolved. Recent review of the literature indicates the most optimal timing of thoracic radiation therapy appears to be concurrent with chemotherapy vs either a sequential or an alternating approach. Studies are currently under way evaluating the optimal volume and dose fractionation scheme to use in the delivery of thoracic radiation therapy. In summary, thoracic radiation therapy significantly improves both local chest control and survival in the treatment of limited-stage SCLC.

Antineoplastic Agents↗
PubMed1997

Synthesis and cytotoxic evaluation of some carbohydrazones and thiocarbohydrazones of various unsaturated ketones and related Mannich bases.

A number of 1-aryl-1-penten-3-ones 1 and related Mannich bases 2 were synthesized and converted either directly or indirectly to the corresponding biscarbohydrazones 3 and 4. Reaction of representative unsaturated ketones with thiocarbohydrazide led to the formation of only the monothiocarbohydrazones 5. The cytotoxicity of these compounds against murine P388 and L1210 cells, human T-lymphocytes and human tumour cell lines was undertaken in order to ascertain their bioactivity and review these data in the light of the theory of sequently cytotoxicity whereby the carbohydrazones would be predicted to be more than twice as cytotoxic as the ketones and Mannich bases from which they were derived. In general, conversion of 1 into 3 was accompanied by a lowering of cytotoxicity. On the other hand, in general the compounds in series 4 were significantly more potent cytotoxic agents than the analogues 2; in fact, some compounds displayed activity comparable with or exceeding that of melphalan. Thus the biscarbohydrazones 4 represent a novel group of cytotoxic agents serving as lead molecules for subsequent development.

Animals↗
PubMed1997

Triple-drug therapy of Helicobacter pylori infection in duodenal ulcer disease.

OBJECTIVE: To evaluate the efficacy of triple-drug therapy for Helicobacter pylori infection and the effect of its eradication on relapse of ulcer in patients with duodenal ulcer (DU) disease. METHODS: Patients with uncomplicated DU who were H. pylori-positive on urease test or histology were given triple-drug therapy (metronidazole, tetracycline, colloidal bismuth subcitrate). Ulcer healing and H. pylori status were assessed one month after completion of therapy. Those with healed ulcers were followed up endoscopically for ulcer recurrence at 3-month intervals for one year or more. RESULTS: Fifty seven of 60 consecutive DU patients (95%) who were H. pylori-positive were taken up for the study; 46 patients (36 men; median age 40 years, range 13-70) completed the study. Thirty one of them (67%) eradicated H. pylori and had healed ulcers at one month post therapy; of 15 patients with persistent H. pylori infection, ulcers healed in 12 (p = ns). After an average follow up of 11 months, 8 of 12 H. pylori-positive patients had relapse of DU compared to 5 of 31 (16%) H. pylori-negative patients (p < 0.01). CONCLUSIONS: Triple-drug therapy was effective and safe for H. pylori infection, the lower rate of eradication observed compared to results elsewhere probably being related to bacterial resistance. Eradication of H. pylori was associated with healing of ulcers, resolution of antral gastritis and a significant fall in the rate of ulcer relapse.

Adult↗
PubMed1997

Sero-prevalence of brucellosis among abattoir personnel of Delhi.

A total of 165 serum samples of abattoir personnel of Delhi were tested by Rose Bengal Plate test (RBPT), Standard tube agglutination test (STAT), Complement fixation test (CFT) and Dot-Enzyme linked immunosorbent assay (Dot-ElISA). The Seroprevalence was 20.60, 12.75, 50.30 and 25.45 percent, respectively on the basis of RBPT, STAT, CFT and Dot-ELISA. Seroprevalence was highest among blood collectors (99.77%) followed by miscellaneous group (72%), animal handlers (68.96%), butchers (68.00%) and sweepers (57.14%). Among veterinarians, Seroprevalance was 28.57%. The Seroprevalence was more among persons of higher age group. The study indicates that abattoir personnel are at high risk to infection with brucellosis.

Abattoirs↗
PubMed1997

Apnea in neonates.

Explore the source record for details and available documents.

Aminophylline↗
PubMed1997

Evaluation of efficacy of standard haemodialysis and verapamil added peritoneal dialysis.

The study was carried out on 30 adult subjects of acute renal failure who were randomly divided into two groups of 15 patients each. Group A patients were subjected to standard haemodialysis (HD) for 4 hours using holofibre dialyser and group B patients received 36 hours of peritoneal dialysis (PD) where Verapamil was added intraperitonealy in the dose of 10 mg/ L/cycle in the clearance periods III, V, VII, IX and XI (Total dose 150 mg). The 36 hours of PD consisted of 36 cycles of one hour duration each and these were divided into 12 clearance periods (CP) of 3 cycles each. Following both the forms of dialytic treatments, there was significant improvement in the signs of uraemia with fall in the blood urea and serum creatinine levels. The peritoneal clearances, percentage fall of urea and creatinine, and protein loss were similar in the two groups (p > 0.5). However, ultrafiltration was significantly higher in the group B. No untoward effects were noticed in group B however group A patients had episodes of hypotension (5)] disequilibrium (6) and cardiac arrhythmias (1). It can be concluded that both clinically and biochemically, 36 hours of Verapamil added PD and 4 hours of hemodialysis are comparable and therefore, peritoneal dialysis may be used more frequently in acute renal failure specially in situations where trained dialysis staff is not available and patients are not haemodynamically stable.

Adult↗
PubMed1997

Evaluation of different rodenticidal baits against rodent population in cucumber (Cucumis sativus) crop fields.

The baits used consisted of 2% zinc phosphide and 0.005% bromadiolone. The baitings were carried out at the flowering stage of cucumber crop. Double baiting treatments comprising zinc phosphide and bromadiolone in different combinations resulted in better reduction of rodent population and crop damage. Deployment of different rodenticidal treatments saved yield loss from 7.00 to 11.82q/ha. Thus, accomplishing cost benefit ratio of 1:88 to 1:107. Bromadiolone followed by bromadiolone, the most profitable combination is suggested for control of rodent population in cucumber crop fields.

Animals↗
PubMed1997

Prevalence of hepatitis C virus associated cryoglobulinemia at a veterans hospital.

OBJECTIVE: To prospectively evaluate the prevalence and clinical spectrum of cryoglobulinemia in a population infected with the hepatitis C virus (HCV). METHODS: Inpatients and outpatients at the Veterans Affairs (VA) Medical Center were recruited for study. Sixty-nine patients with HCV and 68 anti-HCV negative, age and sex matched controls were evaluated for the prevalence of cryoglobulinemia. Clinical and laboratory profiles were obtained in all patients and rheumatologic complaints were sought in 58 anti-HCV positive patients. RESULTS: Twenty-nine (42%) of 69 anti-HCV positive patients and no controls had cryoglobulinemia (p < 0.001). A history of intravenous drug abuse and excessive alcohol ingestion was more prevalent in the anti-HCV positive group compared to controls, (p < 0.001 and p = 0.02, respectively), but was unrelated to the presence or absence of cryoglobulinemia. Of 58 anti-HCV positive patients evaluated for rheumatologic complaints, 12 (21%) reported symptoms; 9 (41%) of 22 with cryoglobulinemia and 3 (8%) of 36 without cryoglobulinemia (p < 0.01). No patient had vasculitis. Antinuclear antibody (ANA) and rheumatoid factor (RF) were evaluated in 19 anti-HCV positive patients with cryoglobulinemia. About one-half were positive for ANA or RF, fewer than 50% of whom had rheumatologic symptoms. Nineteen of the 29 patients with cryoglobulinemia were available for followup after one year. Ten of 19 revealed only trace (< 5%) cryoglobulinemia; 7 were type III, one type I, and none were type II. The character of the remaining 2 cryoglobulins was unknown. Twenty-five liver biopsy specimens were available for review; there were no histological differences between patients with and without cryoglobulinemia. CONCLUSION: The prevalence of HCV related cryoglobulinemia at a VA hospital was 42% and was most often of the type III variety. Although mild rheumatologic symptoms were common in HCV infected patients with cryoglobulinemia, no specific syndrome denoted its presence. The absence of any specific rheumatologic disease in this cohort implies that the pathogenesis of diseases such as essential mixed cryoglobulinemia is multifactorial and that low levels of type III cryoglobulinemia in HCV infected patients are not specific for the diagnosis.

Biopsy↗