Biomedical subjects
Publications and source records attributed to N Ramesh.
The aqueous, methanol, chloroform and hexane extracts of Swertia corymbosa were tested (in vitro) for their antimicrobial efficiency. Maximum inhibitory activity was noticed against Staphylococcus aureus and Salmonella typhi.
Phytochemical investigation of the various extracts of the leaves of Begonia malabarica Lam. (Begoniaceae) resulted in the isolation and identification of six known compounds, viz. friedelin, epi-friedelinol, beta-sitosterol, luteolin, quercetin and beta-sitosterol-3-beta-D-glucopyranoside. The aqueous and organic solvent extracts were also tested against ten human pathogenic bacteria and four fungal strains by the agar-well diffusion method. All the extracts were devoid of antifungal activity against the tested fungi. The hexane extract did not show any activity. The aqueous extracts showed activity against the Gram-negative bacteria except Vibrio parahaemolyticus. The chloroform and methanol extracts showed activity against all the tested bacteria. The study supported the claim of the usefulness of the plant in respiratory tract infections and also suggests its use in diarrhoea and skin diseases caused by pathogenic bacteria.
Containers used in transporting live poultry between production and processing units are a primary source of contamination for processed poultry products. Because disinfection of transport containers (TC) has been difficult to accomplish, it is probable that the choice of appropriate disinfectant and its application are partially or wholly responsible for the failure to adequately eliminate pathogens from TC. Therefore, 13 commercial disinfectants were selected and evaluated for their capacities to destroy Salmonella. The disinfectants were applied in various concentrations on prescribed areas (10 cm diameter circle) of galvanized steel surfaces (representative of TC material) that were artificially contaminated with Salmonella (10(8) cfu/mL) with a mixture of organic material. Likewise, coupons (1.9 cm2) made of the same metallic surfaces and covered with biofilms of Salmonella spp. were tested in the same manner for each disinfectant. Two of the disinfectants completely eliminated Salmonella on the artificially contaminated and biofilm-covered surfaces. These compounds produced logarithmic reductions in Salmonella populations as high as 7.18 within 2 min. One of the two effective disinfectants contained sodium hypochlorite and was effective at a concentration of 0.05% (vol/vol). The other disinfectant was an alkaline peroxide compound and was effective at a concentration of 1% (wt/vol). Evaluation of these two disinfectants under simulated conditions suggested that application under the prescribed regimen could result in effective elimination of Salmonella from TC within a limited period.
The problems encountered when using traditional rectangular pulse hierarchical point process models for fine temporal resolution and the growing number of available tip-time records suggest that rainfall increments from tipping-bucket gauges be modelled directly. Poisson processes are used with an arrival rate modulated by a Markov chain in continuous time. The paper shows how, by using two or three states for this chain, much of the structure of the rainfall intensity distribution and the wet/dry sequences can be represented for time-scales as small as 5 minutes.
From the stems of Indigofera longeracemosa, a novel abietane diterpenoid, indigoferabietone was isolated. The structure was established by spectral techniques. The inhibitory activity of indigoferabietone (1) tested against Mycobacterium tuberculosis and Candida albicans, and the antibacterial activity tested against Staphylococcus aureus, Proteus vulgaris, and Escherichia coli were found to be significant.
Eosinophils in tissues are often present in intimate contact with T cells in allergic and parasitic diseases. Resting eosinophils do not express MHC class II proteins or costimulatory B7 molecules and fail to induce proliferation of T cells to Ags. IL-5 and GM-CSF induce MHC class II and B7 expression on eosinophils and have been reported in some studies to induce eosinophils to present Ag to T cells. The cytokine IL-3, like IL-5 and GM-CSF, is a survival and activating factor for eosinophils and the IL-3 receptor shares with the IL-5 and GM-CSF receptors a common signal transducing beta-chain. IL-3-treated eosinophils expressed HLA-DR and B7.2, but not B7.1 on their surface and supported T cell proliferation in response to the superantigen toxic shock syndrome toxin 1, as well as the proliferation of HLA-DR-restricted tetanus toxoid (TT) and influenza hemagglutinin-specific T cell clones to antigenic peptides. This was inhibited by anti-B7.2 mAb. In contrast, IL-3-treated eosinophils were unable to present native TT Ag to either resting or TT-specific cloned T cells. In parallel experiments, eosinophils treated with IL-5 or GM-CSF were also found to present superantigen and antigenic peptides, but not native Ag, to T cells. These results suggest that eosinophils are deficient in Ag processing and that this deficiency is not overcome by cytokines that signal via the beta-chain. Nevertheless, our findings suggest that eosinophils activated by IL-3 may contribute to T cell activation in allergic and parasitic diseases by presenting superantigens and peptides to T cells.
As it is conventionally done, strategies for incorporating accident--prevention measures in any hazardous chemical process industry are developed on the basis of input from risk assessment. However, the two steps-- risk assessment and hazard reduction (or safety) measures--are not linked interactively in the existing methodologies. This prevents a quantitative assessment of the impacts of safety measures on risk control. We have made an attempt to develop a methodology in which risk assessment steps are interactively linked with implementation of safety measures. The resultant system tells us the extent of reduction of risk by each successive safety measure. It also tells based on sophisticated maximum credible accident analysis (MCAA) and probabilistic fault tree analysis (PFTA) whether a given unit can ever be made 'safe'. The application of the methodology has been illustrated with a case study.
Radiation is an effective means of treating localized prostate cancer. However, up to 40% of men with certain risk factors will develop biochemical failure 5 years after radiotherapy. CV706, a prostate cell-specific adenovirus variant, is currently in clinical trials for the treatment of recurrent organ-confined prostate cancer. We demonstrated previously that a single administration of CV706 at 5 x 10(8) particles/mm3 of tumor eliminated established tumors within 6 weeks in nude mouse xenografts (Rodriguez et al., Cancer Res. 57: 2559-2563, 1997). We now demonstrate that CV706-mediated cytotoxicity is synergistic with radiation. In vitro, addition of radiation to CV706 resulted in a synergistic increase of cytotoxicity toward the human prostate cancer cell line LNCaP and a significant increase of virus burst size, with no reduction in specificity of CV706-based cytopathogenicity for prostate cancer cells. In vivo, prostate-specific antigen (+) LNCaP xenografts of human prostate cancer were treated with CV706 (1 x 10(7) particles/mm3 of tumor), 10 Gy of single fraction local tumor radiation, or both. Tumor volumes of the group treated with CV706 or radiation was 97% or 120% of baseline 6 weeks after treatment. However, when the same dose of CV706 was followed 24 h later with the same dose of radiation, the tumor volume dropped to 4% of baseline at this time point and produced antitumor activity that was 6.7-fold greater than a predicted additive effect of CV706 and radiation. Histological analyses of tumors revealed that, compared with CV706 or radiation alone, combination treatment with two agents increased necrosis by 180% and 690%, apoptosis by 330% and 880%, and decreased blood vessel number by 1290% and 600%, respectively. Importantly, no increase in toxicity was observed after combined treatment when compared with CV706 or radiation alone. These data demonstrate that CV706 enhances the in vivo radioresponse of prostate tumors and support the clinical development of CV706 as a neoadjuvant agent with radiation for localized prostate cancer.
Retroviral vectors encoding glucose-responsive promoters driving furin expression may provide an amplified, glucose-regulated secretion of insulin. We constructed LhI*TFSN virus to encode a glucose-regulatable transforming growth factor alpha promoter controlling furin expression with a viral LTR promoter driving constitutive expression of furin-cleavable human proinsulin. Autologous BB rat vascular smooth muscle cells transduced with LhI*TFSN virus and cultured in 1.7 and 16.7 mM glucose secreted 50.7 +/- 3.2 and 136.0 +/- 11.0 microU (mean +/- SD) of insulin per 10(6) cells per day, respectively. After the onset of diabetes spontaneously diabetic congenic DR lyp/lyp BB rats received stomach implants containing 2 x 10(6) LhI*TFSN-transduced primary rat vascular smooth muscle cells. In eight treated rats there was a major reduction in insulin requirement to as low as 25% of pretreatment level for up to 3 months and one rat became insulin free without hypoglycemia. Intraperitoneal glucose tolerance tests (IPGTTs) in diabetic rats receiving control implants did not show the characteristic decline in blood glucose of normal rats after glucose administration. In contrast, diabetic rats receiving LhI*TFSN-transduced cells showed significant clearances of blood glucose. These data suggest clinically significant levels of glucose-regulated insulin delivery from implanted vascular smooth muscle cells transduced with LhI*TFSN vector.
Seeds of Galactia longifolia Benth. (Fabaceae), locally known as Kaattukollu in Tamil language, used as food by Malayali tribals in the Kolli hills of Namakkal District, Tamil Nadu in South India were analysed for proximate composition, total (true) seed proteins, amino acid composition, fatty acid composition, minerals and antinutritional factors. Crude protein, crude fat, ash and nitrogen free extractives constitute 25.56%, 6.18%, 5.12% and 56.15%, respectively. The caloric value of 100 g dry matter of seed material is 1,601 KJ. The essential amino acids, tryptophan, leucine + isoleucine, arginine and threonine are present relatively in large quantities. The unsaturated fatty acids constitute more than 60%. The seeds are very rich in potassium, magnesium, calcium and phosphorus. Antinutritional factors such as total free phenols, tannins, L-DOPA, hydrogen cyanide and phytic acid is present in minute quantities. The seed meal is consumed after eliminating all the antinutritional factors using the conventional method of soaking seeds in water, boiling with water and decanting for four times by Malayali tribals.
This is a retrospective study of ultrasound examination for patients with blunt scrotal trauma. Fifteen patients were examined over an 18-month period. The purpose of the study was to discover the ultrasonic features of blunt testicular trauma and to distinguish less severe from more severe injury with testicular rupture requiring surgery. Three had ultrasonic findings of acute testicular rupture and this was confirmed by surgery. The ultrasound features of testicular trauma with rupture are irregularity of testicular outline and inhomogeneity of testicular texture. The value of ultrasound in diagnosing patients with testicular rupture and, therefore, requiring urgent surgery is discussed. In our limited study, irregularity of testicular outline was the distinguishing feature of rupture.
The use of general purpose polystyrene (GPPS) as food packaging material is widespread. Therefore, the rate of migration of the styrene in GPPS is of interest in order to predict the potential exposure of consumers to styrene. Studies have shown a relatively weak dependence of the diffusion coefficient on the residual styrene content, and a strong dependence on temperature. We have compared the predictions of the free-volume theory with experimentally measured diffusivity data. The predictions and the measured values are observed to be consistent with each other. These results illustrate the capability of the free-volume theory of transport to predict the diffusivity of trace amounts of impurity in a glassy polymer.
A novel xanthene, 3-isopropyl-9a-methyl-1,2,4a,9a-tetrahydroxanthene (1), was isolated from the stem of Indigofera longeracemosa.
The methanol extract of Bridelia crenulata stem bark (50-1.5625 mg/ml) and its isolated luteoforol (2-0.25 mg/ml) showed concentration-dependent inhibiting activity against all 10 tested bacteria.
Friedelin, epifriedelinol, beta-amyrin, beta-sitosterol, beta-sitosterol 3-beta-D-glucopyranoside, and naringin were isolated from the dried rhizome of Drynaria quercifolia. The methanol extract showed broad and concentration-dependent antibacterial activity.
Induction of filopodia is dependent on activation of the small GTPase Cdc42 and on neural Wiskott-Aldrich-syndrome protein (N-WASP). Here we show that WASP-interacting protein (WIP) interacts directly with N-WASP and actin. WIP retards N-WASP/Cdc42-activated actin polymerization mediated by the Arp2/3 complex, and stabilizes actin filaments. Microinjection of WIP into NIH 3T3 fibroblasts induces filopodia; this is inhibited by microinjection of anti-N-WASP antibody. Microinjection of anti-WIP antibody inhibits induction of filopodia by bradykinin, by an active Cdc42 mutant (Cdc42(V12)) and by N-WASP. Our results indicate that WIP and N-WASP may act as a functional unit in filopodium formation, which is consistent with their role in actin-tail formation in cells infected with vaccinia virus or Shigella.
Repeated silica gel chromatography of the dichloromethane extract of air-dried stems of Indigofera longeracemosa followed by reverse-phase HPLC separation yielded a new decahydropyridoquinoline, rel-(3S, 5R, 6S, SR, 8aR, 12aR)-8-acetoxy-6-butyl-3-isothiocyanatodecahydropyrido (2,1) quinoline.
The pathogenesis of osteogenic sarcoma is not known. Recently, chronic fluoride exposure has been incriminated as having a possible etiologic role by causing a nonspecific osteoblast proliferation. We were interested in exploring the possible relationship between fluoride bone content and p53 mutations. We analyzed p53 mutations in various exons in tissue of osteosarcoma, and correlated the findings with the bone fluoride levels in Indian patients. We analyzed tissue samples from 20 osteosarcoma patients for possible genetic alterations including mutations, and we assessed the extent of fluoride accumulation in bone. Fragments displaying an altered electrophoretic mobility were confirmed as having mutated sequences. Mutation was observed in samples of two cases (10% incidence). Eighteen samples showed bone fluoride levels between 1000 and 27,000 ppm, whereas the 2 mutated samples showed fluoride levels of 64,000 and 89,000 ppm, respectively. The high levels of bone fluoride levels and the similarity of the mechanisms of action between fluoride-induced DNA damage and chemically-induced p53 mutations lead us to propose that high fluoride bone content might have been one of the major factors causing osteosarcoma.