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Biomedical subjects

P Kumar

Publications and source records attributed to P Kumar.

At least 109 records · Page 6Linked to original sources

Evaluation of influenza virus detection by direct enzyme immunoassay (EIA) and conventional methods in asthmatic patients.

Throat gargle specimens of fifty-seven acute asthmatic patients (age range 18-40 years) were collected for the study. Thirty-four patients were found influenza virus positive in acute asthma cases. Influenza virus was isolated by conventional culture method on MDCK cell-line and by enzyme immunoassay test (EIA). The EIA negative specimens were retested after virus amplification on MDCK cell-line. Virus shedding and virus surface receptors assay was carried out to determine influenza virus titre. Airway functions were measured by spirometry. A good relationship was observed between the degree of airflow limitation and presence of influenza virus infection (p < 0.001; r = 0.85). A comparable difference in % FEV1 was observed in relation to the symptoms. The patients with greater viral antigen load had lower % FEV1. Two specimens, which were EIA negative, turned out to be positive after amplification on MDCK cell-line. The sensitivity was 98% and specificity was 100%. It was concluded that EIA method is a useful diagnostic tool as it detects influenza viral antigen quickly as compared to conventional methods.

Adolescent↗

Primary multi-drug resistant tuberculous gumma.

A 28-year old lady presented with three discrete gummatous lesions on the anterior abdominal wall, one at the site of a previous laparoscopic scar. Skin biopsy showed epitheloid cell granulomas and a pus culture and sensitivity (for AFB) performed, showed growth of M. tuberculosis. The culture-isolate was resistant to all the essential anti-TB drugs. The patient was put on second line anti-TB chemotherapy and the gummas resolved.

Adult↗

A novel synthesis of 4H-chromen-4-ones via intramolecular wittig reaction

The acylphosphoranes formed in a sequential manner from the reaction of the silyl ester of O-acyl(aroyl)salicylic acids and (trimethylsilyl)methylenetriphenylphosphorane undergo intramolecular Wittig cyclization on the ester carbonyl to afford the 4H-chromen-4-ones in good to excellent yields.

Journal Article↗

A randomized, double-blind trial comparing azithromycin and clarithromycin in the treatment of disseminated Mycobacterium avium infection in patients with human immunodeficiency virus.

Two hundred and forty-six patients infected with human immunodeficiency virus (HIV) who also had disseminated Mycobacterium avium complex received either azithromycin 250 mg every day, azithromycin 600 mg every day, or clarithromycin 500 mg twice a day, each combined with ethambutol, for 24 weeks. Samples drawn from patients were cultured and clinically assessed every 3 weeks up to week 12, then monthly thereafter through week 24 of double-blind therapy and every 3 months while on open-label therapy through the conclusion of the trial. The azithromycin 250 mg arm of the study was dropped after an interim analysis showed a lower rate of clearance of bacteremia. At 24 weeks of therapy, the likelihood of patients' developing 2 consecutive negative cultures (46% vs. 56%, P=.24) or 1 negative culture (59% vs. 61%, P=.80) was similar for azithromycin 600 mg (n=68) and clarithromycin (n=57), respectively. The likelihood of relapse was 39% versus 27% (P=.21) on azithromycin compared with clarithromycin, respectively. Of the 6 patients who experienced relapse, none of those randomized to receive azithromycin developed isolates resistant to macrolides, compared with 2 of 3 patients randomized to receive clarithromycin [corrected]. Mortality was similar in patients comprising each arm of the study (69% vs. 63%; hazard, 95.1% confidence interval, 1.1 [0.7, 1.7]). Azithromycin 600 mg, when given in combination with ethambutol, is an effective agent for the treatment of disseminated M. avium disease in patients infected with HIV.

AIDS-Related Opportunistic Infections↗

A role for parasite-induced PGE2 in IL-10-mediated host immunoregulation by skin stage schistosomula of Schistosoma mansoni.

Significant quantities of PGE(2) were produced by cercariae of Schistosoma mansoni following incubation with linoleic acid, a free fatty acid found on the surface of the skin. Cyclooxygenase (COX) 2 inhibitors failed to block this PGE(2) production, suggesting that a different biochemical pathway may be involved in the production of PGE(2) by the parasite. In addition, the parasites were also able to induce PGE(2) and IL-10 from human and mouse keratinocytes. Analysis of mouse skin during skin migratory phases of infection confirmed these in vitro observations. COX2 inhibitors blocked the parasite-induced PGE(2) and IL-10 from keratinocytes. Further analysis of the parasite secretions showed that the PGE(2)/IL-10-inducing effect was associated with a fraction <30 kDa molecular size. Addition of this fraction or parasite-stimulated keratinocyte culture supernatant to Con A-stimulated spleen cells resulted in the suppression of cell proliferation. This effect could be blocked by anti-IL-10 treatment. In sharp contrast, attenuation of the parasites with gamma-irradiation significantly abrogated their ability to induce PGE(2) or IL-10 from skin cells. Significance of IL-10 in host immunoregulation by skin stage schistosomula of S. mansoni was further confirmed by using IL-10-deficient mice. In these mice the normal subdued cutaneous reaction to the parasite was absent. Instead, a prominent cellular reaction occurred around the parasite, and there was considerable delay in parasitic migration through the skin. Thus these results suggest a key role for parasite-induced PGE(2) in IL-10-dependent down-regulation of host immune responses in the skin.

Animals↗

Protease inhibitors stimulate hematopoiesis and decrease apoptosis and ICE expression in CD34(+) cells.

Highly active retroviral therapy has been associated with a decline in the frequency of cytopenia in patients with human immunodeficiency virus (HIV) infection. This may result from lower hematologic toxicity of newer antiviral drugs and their increased efficacy against HIV-1. Protease inhibitors, in addition to their effects on HIV replication, appear to affect various cellular functions. Recently, it was reported that ritonavir inhibited caspase-1 expression in normal CD4(+) cells. It was hypothesized that protease inhibitors may improve hematopoietic function owing to their direct effects on the bone marrow progenitor cells. When ritonavir was added to methylcellulose cultures of bone marrow cells from HIV-infected patients and normal controls, colony formation increased 2.4-fold (n = 5) in control cultures and 4-fold (n = 5) in cultures of cells from HIV-infected patients. In the presence of ritonavir, cultures of CD34(+) cells showed markedly decreased apoptosis in comparison with untreated cultures (45% decrease in apoptotic cell number; n = 6). A synthetic inhibitor of caspase 1 (Ac-Tyr-Val-Ala-Asp-aldehyde [single-letter amino acid codes]), which inhibits activation of several caspases including CPP32 and interleukin 1beta-converting enzyme (ICE or caspase 1), also decreased the rate of apoptosis and enhanced colony formation by progenitor cells derived from HIV-infected patients (3-fold; n = 5). In ritonavir-treated samples derived from HIV-infected individuals, the number of cells expressing ICE also decreased. In conclusion, HIV protease inhibitors may, by blocking the caspase-dependent apoptotic pathway, overcome inhibition of hematopoiesis seen in patients with HIV infection, an effect unrelated to their antiviral activity. (Blood. 2000;96:2735-2739)

Antiretroviral Therapy, Highly Active↗

Clinical findings in a patient with FGFR1 P252R mutation and comparison with the literature.

We report on a patient with the skeletal findings of Jackson-Weiss syndrome, who manifests only mild craniofacial anomalies. Molecular analysis of her fibroblast growth factor receptor 1 gene (FGFR1) identified a heterozygous P252R missense mutation, previously only reported with FGFR1-Pfeiffer syndrome like manifestations. Mutations in the immunoglobulin-like, II-III (IgII-III) linker region of FGFR1 and FGFR3 molecules may present as a skeletal dysplasia affecting the appendicular skeleton including, brachydactyly, short broad middle phalanges, phalangeal epiphyseal coning and broad halluces. This communication is a further example of the phenomenon of an activated FGFR molecule resulting in overlapping manifestations in FGFR syndromes.

Abnormalities, Multiple↗

Collective mode in a superconductor with mixed-symmetry order parameter components

We consider a superconducting state with mixed-symmetry order parameter components, e.g., d+is or d+id(') with d(') = d(xy). We argue for the existence of a new orbital magnetization mode which corresponds to oscillations of relative phase straight phi between two components around an equilibrium value of straight phi = pi / 2. It is similar to the "clapping" mode in superfluid 3He-A. We estimate the frequency of this mode omega(0)(B,T) depending on the field and temperature for the specific case of magnetic field induced d(') = d(xy) state. This mode is tunable with a magnetic field with omega(0)(B,T) approximately BDelta(0), where Delta(0) is the magnitude of the d-wave order parameter. We also estimate the velocity s(B,T) of this mode.

Journal Article↗

Tomographic measurement of joint photon statistics of the twin-beam quantum state

We report the first measurement of the joint photon-number probability distribution for a two-mode quantum state created by a nondegenerate optical parametric amplifier. The measured distributions exhibit up to 1.9 dB of quantum correlation between the signal and idler photon numbers, whereas the marginal distributions are thermal as expected for parametric fluorescence.

Journal Article↗

Stress induced phosphate solubilization in bacteria isolated from alkaline soils.

Phosphate solubilizing bacteria NBRI0603, NBRI2601, NBRI3246 and NBRI4003 were isolated from the rhizosphere of chickpea and alkaline soils. All four strains demonstrated diverse levels of phosphate solubilization activity under in vitro conditions in the presence of various carbon and nitrogen sources. Acid production may have contributed to phosphate solubilization, but was not the only reason for phosphate release into the medium. Among the four strains, NBRI2601 was the most efficient strain in terms of its capability to solubilize phosphorus in the presence of 10% salt, pH 12, or 45 degrees C. The strains showed varied levels of phosphate solubilization when the effects of different sources of nitrogen were examined during growth. The presence of low levels of Ca(2+) and EDTA in the medium enhanced phosphate solubilization.

Bacteria↗

Targeted chemoradiation for advanced head and neck cancer: analysis of 213 patients.

BACKGROUND: To determine the survival results, patterns of relapse, and organ preservation effects of a targeted chemoradiation protocol for patients with advanced (stage III-IV) carcinoma of the head and neck. METHODS: Analysis of 213 patients with stage III-IV squamous cell carcinoma treated at UT Memphis between June 1993 and March 1998. Treatment included weekly intra-arterial infusions of cisplatin (150 mg/m(2)/ week x 4) rapidly delivered to the tumor bulk, simultaneous intravenous thiosulfate for systemic drug neutralization, and conventional external-beam irradiation (180-200 cGy/fraction) to a total dose of 68-72 Gy. RESULTS: Tumor response, toxicity, disease control above the clavicle, pattern of relapse, and survival. There were 89 events of grade III-IV toxicity and 6 treatment-related deaths (grade V). Complete response in the primary and regional sites was obtained in 171 of 213 (80%) and 92 of 151 (61%), respectively. The rate of clearance of regional disease after neck dissection was 98%. There were 51 of 195 recurrences (26%): 11 local (5.6%), 5 regional (2.6%), and 35 distant (17.9%). The Kaplan Meier plot projections for overall and cancer-related 5-year survival was 38.8% and 53.6%, respectively, whereas disease control above the clavicle was 74.3%. CONCLUSIONS: We believe this chemoradiation protocol represents an effective management scheme for patients with advanced head and neck cancer with a high rate of organ preservation and possibly improved survival.

Adult↗

Spectrum of respiratory distress in very low birthweight neonates.

The incidence, etiology and the outcome of respiratory distress in 243 consecutive liveborn very low birth weight neonates (VLBW) were analysed. One hundred and forty six (60%) VLBW neonates developed respiratory distress. Hyaline membrane disease, congenital pneumonia and transient tachypnea of the newborn were the major underlying causes (35.6%, 28.1%, and 27.4% respectively). The mortality rate was significantly higher in neonates with respiratory distress (72 of 146, 49.3%) than in those without distress (28 of 97, 28.8%) (p < 0.05). This difference was more sharply reflected in the 1000-1249 birth weight group and in the 29-32 weeks gestation group. Respiratory distress is a significant determinant of VLBW mortality.

Female↗

Impact assessment of school-based sex education program amongst adolescents.

This was a cross-sectional, interview-based study to assess the impact of sex education on the students and the feasibility of such a program. Study sample consisted of 189 students from two secondary schools of Surat city. Impact was assessed by "before and after" administration of questionnaires. Statistical analysis was done by Z tests for difference of means and proportions. Sex education influenced the need perception and the knowledge of the students. After the training, the preferred mean age to start sex education in the two sexes converged to be 15-16 years. Doctors remained the first choice to impart the sex education, followed by school teachers. Knowledge about the STDs and the method(s) of prevention improved significantly (more in boys). Optimum days for conception became known to more students after the training and the gain was more in girls. Increased awareness about the contraceptives (condoms) use was evident in boys and (oral pills and condoms) in girls. The training improved the participation of girls in the post-evaluation program. A positive attitudinal change was observed after the training, towards extra-marital sex. It also removed the myths associated with masturbation. All students were satisfied with the programme, however, two-third of boys considered the duration insufficient.

Adolescent↗

Chediak-Higashi syndrome.

A case of Chediak-Higashi syndrome is reported in a four-year-old boy who presented with recurrent chest infection, partial albinism, hyperpigmentation of the extremities and presence of giant granules in leucocytes and melanocytes in the skin. Parental consanguinity was present. Though uncommon, hyperpigmentation of sun exposed areas may be the initial symptom in Chediak-Higashi syndrome.

Anti-Bacterial Agents↗

Type I hyperprolinemia.

Type I hyperprolinemia is an autosomal recessive disorder characterized by increased plasma and urine proline concentrations due to a deficiency of the enzyme, proline oxidase. This rare inborn error of proline metabolism is generally believed to be a benign condition although many associated clinical abnormalities have been reported. We report two siblings with Type I hyperprolinemia who presented with recurrent seizures. They had elevated plasma proline levels with massive prolinuria without an increased urinary excretion of delta 1-pyrolline-carboxylic acid.

Female↗

Hypoglycemia in small for gestational age babies.

The main objectives of the study were to find the incidence and risk factors associated with development of hypoglycemia in small for gestational age (SGA) babies, to compare haemoglucotest strips (Boehringer Mannheim) with the standard laboratory method (glucose-hexokinase) for estimation of blood glucose, and to measure the insulin and cortisol responses of SGA babies. This was a prospective longitudinal study. The sample included SGA babies and over a period of six months, 127 consecutively born small for gestational age babies were investigated prospectively for development of hypoglycemia in first 48 hrs of life. Plasma samples were taken during episodes of hypoglycemia for insulin and cortisol estimation and compared with non-hypoglycemic controls. The overall incidence of hypoglycemia was 25.2% in SGA babies and 98% of the episodes occurred within first 24 hrs. Compared to non-hypoglycemics, mothers of hypoglycemic babies had higher incidence of receiving i.v. fluids (5% dextrose) during labour. The hypoglycemic babies were more likely to be sick and oral feeds had been initiated by one hour of life in only 37% of them compared to 63% of non-hypoglycemic babies. Plasma insulin/glucose ratio was significantly higher in hypoglycemic than non-hypoglycemic babies, whereas the cortisol levels were similar. Small for gestational age babies are highly prone to develop hypoglycemia in first 24 hrs of life.

Blood Glucose↗