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Biomedical subjects

P Kumar

Publications and source records attributed to P Kumar.

At least 163 records · Page 9Linked to original sources
PubMed2000

Acquired immunodeficiency syndrome presenting as testicular tuberculosis.

A 50 year old heterosexual male presented with fever and cough with expectoration of months duration, and swelling in the right testis. The serological tests showed positivity for HIV 1 and 11 antibodies. Testicular biopsy from the right testis showed epitheloid cell granulomas with central caseous necrosis and peripheral mantle of lymphocytes and plasma cells. Zeihl-Neelsen stain on tissue sections showed AFB positivity. To the best of our knowledge this is the second reported case of acquired immunodeficiency syndrome presenting as testicular tuberculosis.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Ovarian strumal carcinoid--report of a case that matastasized.

Ovarian teratomas are known for their ability to form a wide variety of tissues. One unusual example of this potential is the strumal carcinoid in which the thyroid tissue is found in intimate association with carcinoid tumor. Although considered as a malignant transformation of struma ovarii, it is almost always benign. We report a rare case of strumal carcionid in a 44 year old lady who had metastasis in the contralateral ovary, myometrium and lungs.

Adult↗
PubMed2000

Subacute (90 days) oral toxicity studies of Kombucha tea.

Kombucha tea (KT) is a popular health beverage and is used as an alternative therapy. KT is prepared by placing the kombucha culture in solution of tea and sugar and allowing to ferment. The inoculum is a fungus consisting of symbiotic colony of yeast and bacteria. KT is consumed in several countries and is believed to have prophylactic and therapeutic benefits in a wide variety of ailments, viz., intestinal disorders, arthritis, ageing and stimulation of immunological system. Though KT is used in several parts of the world its beneficial effects and adverse effects have not been scientifically evaluated. Since there are no animal toxicological data on KT, subacute oral toxicity study was carried out. Five groups of rats were maintained: (a) control group given tap water orally, (b) KT given 2 ml/kg orally, (c) plain tea (PT) given 2 ml/kg orally, (d) KT given in drinking water, 1% (v/v) and (e) PT given in drinking water, 1% (v/v). The rats were given this treatment daily for a period of 90 days. Weekly records of weight, feed intake, water intake and general behaviour were monitored. There was no significant difference in the growth of the animals as evidenced by the progressive body weight change. The organ to body weight ratio and histological evaluation did not show any toxic signs. The haematological and biochemical variables were within the clinical limits. The study indicates that rats fed KT for 90 days showed no toxic effects.

Administration, Oral↗
PubMed2000

Seropositivity for intracellular bacterial infections among abattoir associated personnels.

Studies were carried out to detect the antibodies against zoonotic intracellular bacterial infections viz., brucellosis, listeriosis and tuberculosis in abattoir associated personnel employing dot-ELISA. Out of 165 serum samples tested 25.5, 40.0 and 10.9 per cent were detected as positive for brucellosis, listeriosis and tuberculosis, respectively. Immunodetection of these occupationally exposed persons for IgM as well as IgG antibodies revealed positivity for IgM, IgG and IgM + IgG in 8.5, 17.6 and 13.9 per cent for listeriosis and 5.5, 2.4 and 3.0 for tuberculosis respectively. Antibodies against brucellosis and listeriosis both were detected in 10.9 per cent persons, while 6.7 per cent persons were positive for both listeriosis and tuberculosis. No person was found positive with both brucellosis and tuberculosis. All the three infections were detected in 3.6 per cent persons.

Abattoirs↗
PubMed1999

Properties of mixed backbone oligonucleotides containing 3'-O-methyl ribonucleosides.

Oligonucleotides containing 3'-O-methyl ribonucleosides were synthesized, and their thermal stabilities and global conformations with RNA and DNA have been studied. The duplexes displayed lower T(m) values as compared to the unmodified ones, and adopted A-conformations. Furthermore, they are not a substrate for RNase H, are slightly resistant to snake venom phosphodiesterase, and are not cleaved by nuclease S 1.

Base Sequence↗
PubMed1999

Selenium effects on gallium arsenide induced biochemical and immunotoxicological changes in rats.

The influence of selenium (6.3 and 12.6 micromol/kg, intraperitoneally) on the disposition of gallium and arsenic and a few gallium arsenide (GaAs) sensitive biochemical variables was studied in male rats. Concomitant administration of Se and GaAs (70 micromol/kg, orally, 5 days a week for 4 weeks) significantly prevented the accumulation of arsenic while, the gallium concentration reduced moderately in the soft organs. The biochemical (haematopoietic and liver) and immunological variables however, responded less favorably to selenium administration. Most of the protection was however observed with the dose of 12.6 micromol rather than at 6.3 micromol. The results thus suggest a few beneficial effects of selenium in preventing the appearance of signs of GaAs toxicity like preventing inhibition of blood delta-aminolevulinic acid dehydratase (ALAD), hepatic malondialdehyde (MDA) formation and the accumulation of gallium and arsenic concentration.

Animals↗
PubMed1999

Radiation-induced normal tissue injury: role of adhesion molecules in leukocyte-endothelial cell interactions.

The late onset of necrosis and fibrosis in normal tissues can be a serious consequence of radiotherapy in cancer patients. Because radiation-induced vascular injury precedes the tissue damage, vascular injury is regarded as crucial in the pathogenesis of tissue damage. An understanding of the processes responsible is essential to develop strategies for the amelioration of radiation-induced normal tissue damage. Leukocyte infiltration is commonly observed at sites of irradiation and is likely to lead to the acceleration and/or induction of parenchymal atrophy, fibrosis and necrosis in normal tissues following radiotherapy. The molecular mechanisms mediating leukocyte infiltration of tissues during inflammation have been studied extensively. It is now well established that cell adhesion molecules (CAMs) expressed on leukocytes and endothelial cells control the trafficking of leukocytes from the blood vessel lumen in these conditions. CAMs including E (endothelial), P (platelet) and L (leukocyte)-selectins, intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), beta1 and beta2 integrins and CD31 are involved in the cascade of events resulting in rolling, arrest and transmigration of leukocytes through the inflamed endothelium. Whether a similar sequence of molecular events induces leukocyte sequestration in irradiated normal tissues is not known. This review is focussed on the role of CAMs in radiation-induced leukocyte infiltration of normal tissues and the therapeutic implications of these findings.

Animals↗
PubMed1999

Rapid conditions for the cleavage of oligodeoxyribonucleotides from cis-diol-bearing universal polymer supports and their deprotection.

Two sets of deprotection conditions have been evolved for the deprotection of oligodeoxyribonucleotides and their cleavage from commercially available cis -diol group-bearing universal polymer supports. In the first case, oligodeoxyribonucleotides anchored on the universal support were subjected to one of the standard deprotection conditions followed by treatment with aqueous 0.5 M sodium chloride + 0.2 M sodium hydroxide solution for 30 min at room temperature. In the second case, oligonucleotides bound to the universal support were treated with methanolic sodium hydroxide solution under microwave radiation to obtain fully deprotected oligomers within 4 min. Under both conditions, the cleavage of oligonucleotides from the support and their deprotection occurred quantitatively without any side product formation. The cleaved oligonucleotides were found to be identical in all respects (retention time on HPLC and biological activity in PCR) to the corresponding standard oligo-nucleotides.

Chromatography, High Pressure Liquid↗
PubMed1999

Presynaptic action of adenosine on a 4-aminopyridine-sensitive current in the rat carotid body.

1. Plasma adenosine concentration increases during hypoxia to a level that excites carotid body chemoreceptors by an undetermined mechanism. We have examined this further by determining the electrophysiological responses to exogenous adenosine of sinus nerve chemoafferents in vitro and of whole-cell currents in isolated type I cells. 2. Steady-state, single-fibre chemoafferent discharge was increased approximately 5-fold above basal levels by 100 microM adenosine. This adenosine-stimulated discharge was reversibly and increasingly reduced by methoxyverapamil (D600, 100 microM), by application of nickel chloride (Ni2+, 2 mM) and by removal of extracellular Ca2+. These effects strongly suggest a presynaptic, excitatory action of adenosine on type I cells of the carotid body. 3. Adenosine decreased whole-cell outward currents at membrane potentials above -40 mV in isolated type I cells recorded during superfusion with bicarbonate-buffered saline solution at 34-36 C. This effect was reversible and concentration dependent with a maximal effect at 10 microM. 4. The degree of current inhibition induced by 10 microM adenosine was voltage independent (45.39 +/- 2. 55 % (mean +/- s.e.m.) between -40 and +30 mV) and largely ( approximately 75 %), but not entirely, Ca2+ independent. 4-Aminopyridine (4-AP, 5 mM) decreased the amplitude of the control outward current by 80.60 +/- 3.67 % and abolished the effect of adenosine. 5. Adenosine was without effect upon currents near the resting membrane potential of approximately -55 mV and did not induce depolarization in current-clamp experiments. 6. We conclude that adenosine acts to inhibit a 4-AP-sensitive current in isolated type I cells of the rat carotid body and suggest that this mechanism contributes to the chemoexcitatory effect of adenosine in the whole carotid body.

4-Aminopyridine↗
PubMed1999

Efficacy of targeted chemoradiation and planned selective neck dissection to control bulky nodal disease in advanced head and neck cancer.

PURPOSE: To determine the efficacy of targeted chemoradiation with the radiation plus platinum (RADPLAT) protocol and planned selective neck dissection in patients with N2 to N3 nodal disease associated with upper aerodigestive tract carcinoma. METHODS: Analysis of 52 patients with N2a, N2b, or N3 disease involving 60 heminecks treated with intraarterial cisplatin, 150 mg/m2, and intravenous sodium thiosulfate, 9 g/m2, on days 1, 8, 15, and 22; radiation therapy, 180 to 200 cGy per fraction for 35 fractions (total dose, 68-74 Gy); and planned neck dissection (33 of 35 procedures were selective). RESULTS: Of the 56 evaluable heminecks, a clinical complete response was achieved in 33 (59%). Within this group, 16 neck dissections were performed, none of which yielded disease on pathological examination. A clinical partial response was obtained in 21 heminecks, of which 18 subsequently had a neck dissection, yielding disease on pathological examination in 14. In all cases, it was possible to completely excise all adenopathy with clear margins on pathological examination. The rate of regional disease control among the 56 evaluable heminecks was 91% (51/56) (median follow-up, 36 months). Four failures were associated with uncontrolled disease at other sites, and 1 was an isolated neck recurrence. CONCLUSION: Selective neck dissection appears to be an effective adjunct to targeted chemoradiation in controlling N2 to N3 neck disease.

Adult↗
PubMed1999

Concomitant radiation therapy and targeted cisplatin chemotherapy for the treatment of advanced pyriform sinus carcinoma: disease control and preservation of organ function.

BACKGROUND: Squamous cell carcinoma of the pyriform sinus is an unfavorable disease which frequently presents in advanced stages. Despite aggressive "standard treatment" involving debilitating surgery and postoperative radiation therapy treatments, the survival and functional outcome for pyriform sinus carcinoma remains poor. Hence, we reviewed our experience in the management of advanced pyriform sinus carcinoma using "organ preservation" chemoradiation therapy. METHODS: Twenty-five patients diagnosed with stage III/IV pyriform sinus squamous cell carcinoma treated with supradose, intra-arterial targeted cisplatin, and concomitant radiotherapy were analyzed for response rates, survival, pattern of failure, and function of the preserved organs. Our protocol consisted of weekly intra-arterial infusions of cisplatin at 150 mg/m(2) x 4 and concurrent radiation therapy at 1.8 Gy or 2.0 Gy/fraction to a planned total of 68-74 Gy to the primary site/overt nodal disease. RESULTS: Nineteen (76%) of the 25 patients were diagnosed with stage IV disease, 17 of whom were first seen with bulky lymphadenopathy (ie, N2-N3 disease) while 10 had T4 lesions. Twenty-four of 25 patients were evaluable for response assessment. Complete response rates of 92% and 76% were achieved at the primary site and in lymph nodes, respectively. Hence, the overall complete response rate in the neck was 76% (16/21). At a median follow up interval of 42 months (range = 30-58 months), the projected 5-year overall and disease-specific survival using the Kaplan-Meier method are 23% and 50% respectively. No patient has developed recurrence at the primary site and only one patient relapsed regionally, which was surgically salvaged for an "above clavicle" disease control rate of 88% and an organ preservation rate of 88%. Almost 90% of the patients have achieved a satisfactory voice and 70% are able to swallow at 12 months postcompletion of therapy. CONCLUSION: Our chemoradiation protocol is as effective as other treatment modalities for patients with advanced pyriform sinus carcinoma while maintaining organ preservation and function in the majority of the patients.

Aged↗
PubMed1999

Efficacy of curcumin in the management of chronic anterior uveitis.

Curcumin, obtained from rhizomes of Curcuma longa, was administered orally to patients suffering from chronic anterior uveitis (CAU) at a dose of 375 mg three times a day for 12 weeks. Of 53 patients enrolled, 32 completed the 12-week study. They were divided into two groups: one group of 18 patients received curcumin alone, whereas the other group of 14 patients, who had a strong PPD reaction, in addition received antitubercular treatment. The patients in both the groups started improving after 2 weeks of treatment. All the patients who received curcumin alone improved, whereas the group receiving antitubercular therapy along with curcumin had a response rate of 86%. Follow up of all the patients for the next 3 years indicated a recurrence rate of 55% in the first group and of 36% in the second group. Four of 18 (22%) patients in the first group and 3 of 14 patients (21%) in the second group lost their vision in the follow up period due to various complications in the eyes, e.g. vitritis, macular oedema, central venous block, cataract formation, glaucomatous optic nerve damage etc. None of the patients reported any side effect of the drug. The efficacy of curcumin and recurrences following treatment are comparable to corticosteroid therapy which is presently the only available standard treatment for this disease. The lack of side effects with curcumin is its greatest advantage compared with corticosteroids. A double blind multi-centric clinical trial with this drug in CAU is highly desirable to further validate the results of the present study.

Adult↗
PubMed1999

Influence of bone-lead stores on the observed effectiveness of lead hazard intervention.

Lead hazard interventions have reduced children's blood-lead concentrations, but do not eliminate lead altogether from the bloodstream. Several studies suggest that blood-lead concentrations, measured 6 to 12 months after such interventions, decline by approximately 25%. The Environmental Protection Agency is preparing to promulgate a rule prescribing residential lead levels in paint, dust, and soil that constitute a lead-based paint hazard. Such a rule will prompt interventions of primary prevention character (i.e., precluding exposure before it occurs) rather than the secondary prevention character interventions (i.e., alleviating exposure after it has adversely affected the resident child) documented in the literature. It is important to attempt to estimate the efficacy achieved from the primary prevention interventions prompted by the rule's promulgation. As bone-lead stores represent the principal confounding factor to relating secondary prevention results to primary prevention, this paper addresses the impact of lead stored in bone, which may later be released to the blood and other parts of the child's body. A simple, but thoroughly documented, modeling exercise is presented to estimate the maximum length of time for which bone-lead stores alone could account for continuing elevated blood-lead levels observed in children following an intervention. The approach is based on a two-compartment model for the transfer of lead between blood and bone tissues within the body and the elimination of lead from the body. Modeling results suggest that bone-lead mobilization can impact blood-lead levels of young children for considerably long periods following an intervention. These results may explain the seemingly contradictory fact that low declines in blood-lead concentrations are observed despite the significant reduction in residential dust-, paint-, and soil-lead levels observed following lead hazard interventions. An intervention which reduces a 5-year-old child's total lead exposure by 50% might, due to mobilized bone-lead stores, produce only a 25% decline in the child's blood-lead concentrations measured 12 months following the intervention. The results also suggest, however, that those intervention strategies for which less than 25% declines were observed 12 months following the intervention likely eliminated less than 50% of the children's total lead exposure.

Bone and Bones↗
PubMed1999

Cross-correlated quadrupolar spin relaxation and carbon-13 lineshapes in the (13)CD(2) spin grouping.

Lineshape calculations are reported for a spin system consisting of a spin-12 nucleus scalar-coupled to two magnetically equivalent spin-1 nuclei, e.g., a CD(2) group. It is found that, because of the differential line broadening, the peak height ratio of the five spin-12 nucleus transitions is expected to deviate from the integrated intensity ratio of 1:2:3:2:1. The deviation is dependent on the extent of cross-correlation between the two quadrupolar interactions. The theoretical predictions for peak height ratios and for bandshapes are tested for the carbon-13 spectrum of perdeuterated ethylene glycol, and iterative fitting is used to obtain an estimate of the extent of the correlation between the quadrupolar interactions for the two deuterons.

Carbon Isotopes↗
PubMed1999

Sigmoid volvulus: study from a north Indian hospital.

PURPOSE: The aim of this study was to review our experience with sigmoid volvulus and to compare the various surgical procedures performed for treatment of sigmoid volvulus. METHODS: A retrospective study of 111 patients with sigmoid volvulus treated at University Hospital in northern India during last six years was performed. RESULTS: Mean age for sigmoid volvulus was 51.1 +/- 15.3 years, with a male-to-female ratio of 2.5:1. Duration of symptoms was 4.3 +/- 2.6 days. Plain radiographs of the abdomen suggested the diagnosis in 76 cases (68.47 percent). Resection of the bowel was performed in 40 cases with gangrenous sigmoid colon and 6 cases with viable colon. Nonresectional procedure in the form of colocolopexy (fixation of sigmoid to transverse colon) or extraperitonealization was performed in 13 and 44 cases, respectively. Mortality was 6.3 percent (n = 7). No recurrence was seen after resection and extraperitonealization, whereas 5 of 13 cases (38.5 percent) had recurrence after colocolopexy. CONCLUSION: Resection and extraperitonealization of the sigmoid colon are the suitable alternatives for nongangrenous sigmoid volvulus. Colocolopexy is not indicated, because of the associated high recurrence rate.

Aged↗
PubMed1999

Apolipoprotein B mRNA editing and apolipoprotein gene expression in the liver of hyperinsulinemic fatty Zucker rats: relationship to very low density lipoprotein composition.

We previously demonstrated increased apolipoprotein B (apoB) mRNA editing, elevated levels of mRNA for the catalytic component of the apoB mRNA editing complex, apobec-1, and increased secretion of the product of the edited mRNA, apoB48, in very low density lipoproteins (VLDL) in primary cultures of Sprague-Dawley rat hepatocytes following insulin treatment. In order to determine the effect of in vivo hyperinsulinemia on these processes, we determined apoB mRNA editing, apobec-1 expression, hepatic expression of mRNA for apoB and other VLDL apoproteins, and the quantity and composition of plasma VLDL in the hyperinsulinemic fatty Zucker rat. Total apoB mRNA content of the livers of the fatty rats and lean littermates did not differ; however, edited apoB message coding for hepatic apo B48, and abundance of mRNA for the catalytic subunit of the apoB mRNA editing complex, apobec-1, was increased by 1.7- and 3.3-fold, respectively, in fatty rats. ApoCIII mRNA abundance was increased in livers of fatty rats as well, but the abundance of hepatic apoE mRNA in the fatty animal was not different from that of the lean rat. Hepatic apoAI mRNA abundance was also increased in the fatty rats. Associated with increased apoB mRNA editing, was the 1.7-fold increase in the fraction of apoB in plasma as apoB48 in fatty rats. VLDL-triglyceride and -apoB in plasma were 15- and 3-fold higher, respectively, in fatty Zucker rats compared to lean littermates, indicating both enrichment of VLDL with triglycerides and increased accumulation of VLDL particles. Increased hepatic expression of mRNA for apoCIII and apoAI was associated with increased content of apoC (and relative depletion of apoE) in VLDL of fatty rats, and plasma apoAI was increased in fatty Zucker rats, primarily in the HDL fraction. The current study provides further evidence that chronic exposure to high levels of insulin influences both the quantity of and lipid/apoprotein composition of VLDL in plasma. The increased apoC and decreased apoE (as well as increased triglyceride) content of VLDL in the fatty Zucker rat observed in the current study may affect VLDL clearance and therefore may be a factor in the observed accumulation of VLDL in the plasma of the fatty hyperinsulinemic Zucker rats.

Animals↗
PubMed1999

Helium vapour injury: a case report.

We report a case in which quick freeze injury occurred to both hands by helium vapour at extremely low temperatures. At the time of injury the victim was wearing protective gloves which were removed quickly after the accident. This prompt removal of gloves reduced the depth and severity of the injury. Initially he was treated by rapid thawing by immersing the hands in luke warm water (37 degrees C) and administering heparin by drip to prevent microvascular thrombosis. Delayed skin grafting was performed with good functional recovery. The circumstances accompanying this injury and preventive measures are discussed.

Adult↗