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Biomedical subjects

M Nath

Publications and source records attributed to M Nath.

At least 19 recordsLinked to original sources
PubMed2005

Differential expression of inducible nitric oxide synthase and cytokine mRNA in chicken lines divergent for cutaneous hypersensitivity response.

Phytohemagglutinin (PHA)-induced delayed-type hypersensitivity is an immunocompetent trait considered an indicator of cell-mediated immune or T-cell responses. Divergent selection was performed to generate high and low lines for response to PHA-P. Extreme-responder birds of the F2 generation in each line were used to study possible differences in macrophage activity and the associated functional genes. To evaluate macrophage activity, nitric oxide (NO) was estimated both systemically in serum and in in vitro monocyte culture. Semi-quantitative RT-PCR was used to detect the differential mRNA expression patterns of iNOS and MIP-1beta in monocyte culture, whereas T(H)1 cytokines (IL-2 and IFN-gamma) were studied in peripheral blood mononuclear cells (PBMC) at different time intervals after lipopolysaccharide (LPS) induction. The high line showed strong systemic, as well as in vitro NO production, compared to the low line, upon stimulation with NDV and LPS, similar to early and high iNOS mRNA expression. Following the pattern of iNOS gene expression, an early strong expression of cytokines with powerful iNOS-inducing action, such as IFN-gamma and the chemokine MIP-1beta, was observed in the high line. In contrast, for response to PHA-P, low expression of IL-2 was observed in the high compared to the low line. In conclusion, the study revealed that divergent selection for response to PHA-P resulted in a divergent effect on T(H)1 cell activity, resulting in altered macrophage function in chickens. Selection, based on response to PHA-P, could lead to more resistant birds or birds with an enhanced immune response.

Animals↗
PubMed2004

Identifying critical parameters in the dynamics and control of microparasite infection using a stochastic epidemiological model.

A stochastic epidemic model is presented to study infection transmission dynamics, and hence epidemic severity and disease incidence, in a closed population. The aim was to understand the relative importance of various parameters that influence the dynamics of potential epidemics, particularly when the genetic mechanisms of resistance or tolerance to infection are considered. Simulations explored the effect of varying the transmission coefficient, latent period, recovery period, mortality rate, and the period of loss of immunity on overall epidemic outcomes. The critical parameters influencing the transmission of infection, and hence disease incidence, were the transmission coefficient, the latent period, and the recovery period; the period of loss of immunity had only trivial effects. Ideally, control strategies should decrease the transmission coefficient and/or increase the latent period and/or decrease the recovery period. By equating measured traits with disease transmission parameters, the model described in this paper can be used to identify which disease resistance genes or QTL will be truly effective in helping to develop disease-resistant livestock that suffer fewer epidemics and side-effects of infection. In particular, emphases should be placed on finding genes that decrease the transmission of infection, increase the latent period, or decrease the recovery period.

Animals↗
PubMed2001

Synthesis and antiviral activity of novel acyclic nucleoside analogues of 5-(1-azido-2-haloethyl)uracils.

We present the discovery of a novel category of 5-substituted acyclic pyrimidine nucleosides as potent antiviral agents. A series of 1-[(2-hydroxyethoxy)methyl] (5-7), 1-[(2-hydroxy-1-(hydroxymethyl)ethoxy)methyl] (8-10), and 1-[4-hydroxy-3-(hydroxymethyl)-1-butyl] (11-13) derivatives of 5-(1-azido-2-haloethyl)uracil were synthesized and evaluated for their biological activity in cell culture. 1-[4-Hydroxy-3-(hydroxymethyl)-1-butyl]-5-(1-azido-2-chloroethyl)uracil (12) was the most effective antiviral agent in the in vitro assays against DHBV (EC(50) = 0.31-1.55 microM) and HCMV (EC(50) = 3.1 microM). None of the compounds investigated showed any detectable toxicity to several stationary and proliferating host cells.

Animals↗
PubMed2001

MoSe2 and WSe2 nanotubes and related structures.

MoSe2 and WSe2 nanotubes are obtained by the reduction of the corresponding triselenides in hydrogen or by the decomposition of the ammonium selenometallates in a hydrogen atmosphere.

Journal Article↗
PubMed2001

The ability of helical CT to preoperatively stage endometrial carcinoma.

OBJECTIVE: This study evaluated helical CT as an imaging modality for preoperative staging of endometrial carcinoma. MATERIALS AND METHODS: Three radiologists retrospectively and independently reviewed the preoperative helical CT scans of 25 consecutive patients with endometrial carcinoma. The presence or absence of deep myometrial invasion and the presence or absence of cervical involvement were evaluated on helical CT and compared with pathologic findings at hysterectomy. RESULTS: Helical CT has a sensitivity of 83% and a specificity of 42% for the detection of deep myometrial invasion (stage IC). Helical CT has a sensitivity of 25% and a specificity of 70% for the detection of cervical involvement (state II). These results compare poorly with those of MR imaging (sensitivity 92%, specificity 90% for the detection of deep myometrial invasion; sensitivity 86%, specificity 97% for the detection of cervical involvement). CONCLUSION: Helical CT is insensitive and nonspecific compared with MR imaging for the preoperative staging of endometrial carcinoma. MR imaging remains the imaging modality of choice.

Aged↗
PubMed2000

Cytomorphologic features of classic and variant lobular carcinoma: A comparative study.

There are several subtypes of lobular carcinoma (LC), and their cytomorphologic features differ from classic lobular carcinoma (CLC). The finer details of the differences between CLC and variant lobular carcinoma (VLC) have not been adequately studied. A comparative study of 54 cases of CLC and VLC was done in order to verify any statistically significant differences between them. All cases had histologic confirmation of the diagnosis. Six parameters, which included cellularity, signet-ring cells, intracytoplasmic lumina (ICL), anisonucleosis, cell size, and prominent nucleoli, were studied. The only statistically significant findings were cellularity and cell size when compared to CLC. The cellularity in VLC was higher and the cells in VLC were larger when compared to CLC. There are no definite diagnostic features to identify VLC; however, in a cellular specimen with plenty of large cells with other features of LC, one should have a high index of suspicion of VLC.

Biopsy, Needle↗
PubMed1996

Clinical profile of stroke in relation to glycaemic status of patients.

Present study was undertaken in fifty consecutive patients of acute stroke to assess the role of glycemic status on clinical profile of stroke. Majority of patients (76%) were in age group of 41-70 years. The patients were classified into four groups: euglycemics (33), known diabetics (8), newly diagnosed diabetics (6) and stress hyperglycemics (3). Diabetics as well as stress hyperglycemics had higher prevalence of larger sized severe haemorrhagic stroke with poor outcome and there was positive correlation between them.

Acute Disease↗
PubMed1993

Urologic aspects of traumatic central cord syndrome.

Central cord syndrome (CCS) is a subset of spinal cord injury, characterized by more motor involvement of the upper extremities than the lower extremities and sacral sensory sparing. Patients with central cord syndrome have been reported to have a good rehabilitation and urologic outcome. Our purpose was to assess the urologic outcome in a group of patients with central cord syndrome. We reviewed 23 patients with central cord syndrome who were admitted to Hines VA Hospital between 1983 and 1991, 20 of whom were older than 50 years of age. Urodynamic studies showed detrusor hyperreflexia with a synergistic EMG in 15 patients and detrusor hyperreflexia with external urethral sphincter dyssynergia (DSD) in five patients. Three patients with no urologic problems were not tested. Bladder sensation was preserved during filling in all patients. At follow-up (median = 2-4 months), 16 patients (70 percent) were voiding, seven of whom required either occasional external or intermittent catheterization; nine were voiding independently. The seven other patients (30 percent) required either continuous external or intermittent catheterization (including the five with DSD). Urologic morbidity in the period after SCI included: urinary tract infections (12), renal (2) and bladder calculi (2), superficial bladder cancer (1), epididymitis (1) and none (6). Fifteen patients (65 percent) were ambulatory at follow-up while four patients needed wheelchairs. Data were not available for the other four patients. Urodynamic studies in three of the wheelchair-bound patients showed that two of them had DSD. Most patients with central cord syndrome have favorable urologic and rehabilitation outcomes and can be managed conservatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Fluoride metabolism and fluoride content of stones from children with endemic vesical stones.

Twenty children with endemic vesical stones showed normal plasma and urinary excretion of fluoride on a mean fluoride intake of 2.5 +/- 0.8 mg/24 h. The mean fluoride content of the stones obtained from these children was 315.6 +/- 264.9 micrograms/g in the nucleus and 229.9 +/- 212.8 micrograms/g in the periphery (this was not statistically significant). Calcium-containing stones had a higher fluoride content than stones containing uric acid and ammonium urate. It was concluded that children with endemic vesical stones have normal fluoride metabolism. Trace quantities of fluoride present equally in the nucleus and peripheral parts of the stones suggest that fluoride does not cause initiation or growth of the nucleus of vesical stones and is adventitiously deposited with calcium salts in these stones.

Calcium Oxalate↗
PubMed1988

Chemical evolution of peroxidase--amino acid pentacyanoferrate (II) complexes as model.

Complexes of the type [Fe(II)(CN)5(L)]n- (where n = 3, or 4; L = glycine, histidine, imidazole, and triglycine) are proposed as evolutionary model of peroxidases. Detailed kinetic investigation for disproportionation of hydrogen peroxide catalysed by [Fe(II)(CN)5(L)]n- complexes at 40 degrees C and pH 9.18 are discussed. Decomposition of hydrogen peroxide catalysed by above complexes conforms to Michaelis-Menten type kinetics.

Amino Acids↗
PubMed1984

Ascorbic acid in thyroidectomized rats. I) Biosynthesis and catabolism.

Thyroidectomized rats showed a decrease in ascorbic acid and dehydroascorbic acid, with almost no alterations in the diketogulonic acid in liver and kidney. Total ascorbic acid in urine was found to be increased, whereas glucuronic acid in urine decreased significantly. There were no significant changes in the activities of ascorbic acid synthesizing enzymes. Activities of the degrading enzymes were found to increase significantly in the liver, with no remarkable change in their activities in kidney. Daily administration of thyroxine for 10 days to thyroidectomized rats normalized the activities of dehydroascorbatase and 2,3 diketoaldonate decarboxylase in the liver, whereas single administration of thyroxine on the 7th day after thyroidectomy could not bring about such restoration. It seems that thyroxine has no direct role on ascorbic acid metabolism in rats.

Animals↗