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Biomedical subjects

N Ramesh

Publications and source records attributed to N Ramesh.

At least 19 recordsLinked to original sources
PubMed2006

Reno-protective effect of N-acetyl cysteine in patients with impaired renal function undergoing coronary angiography and interventions.

BACKGROUND: The increasingly frequent use of contrast enhanced imaging for diagnosis or interventions in patients with CAD has generated concern about avoidance of contrast induced nephropathy (CIN). Reactive oxygen species have been shown to cause CIN. OBJECTIVES: Angiographic contrasts worsen the renal function in patients with renal failure. We studied the reno-protective action of the antioxidant N-Acetyl cysteine (NAC) in patients undergoing coronary procedures. METHODS: Retrospective analysis of 51 patients with elevated serum creatinine levels (> or = 15mg%) was done, 24 of whom received NAC prior to the procedure(NAC group) and 27 who did not (Non NAC group). NAC was administered in a dose of 400 mg twice daily for four doses starting on the day prior to the procedure. Both groups of patients were hydrated with 0.45% saline at 1 ml/kg/hr for 12 hours prior to and 12 hours following the procedure. Both groups were comparable with regard to age, sex, coronary risk profile, myocardial infarction history, left ventricular function and the drugs received. Serum urea and creatinine were measured on the day prior to and the day following the angiographic procedure. RESULTS: Nine out of 51 patients developed more than 0.5mg% rise in serum creatinine level; 1 in the NAC group and 8 in the non NAC group (p<0.05), 24 hours after injection of the contrast medium. In the NAC group mean serum creatinine level decreased from 1.94 +/- 0.56 to 1.67 +/- 0.56 and blood urea from 47.58 +/- 20 to 41.58 +/- 15.1. In the non NAC group serum creatinine increased from 1.75 +/- 0.31 to 1.98 +/- 0.56 and blood urea from 44.96 +/- 15.5 to 52.85 +/- 20.1 (p<0.05). This corresponds to an increase in creatinine clearance from 30ml/min to 35.92ml/min in the NAC group and a decrease from 34.42ml/min to 29.87ml/min in the non NAC group. There was no significant difference in the levels of sodium and potassium before and after the procedure in both the groups. CONCLUSION: We conclude that prophylactit administration of N-Acetyl Cysteine along with hydration diminishes the incidence of deterioration of renal function induced by contrast agents in patients with renal insufficiency during coronary angiographic procedures.

Acetylcysteine↗
PubMed2005

Valsalva and gravitational variability of the internal jugular vein and common femoral vein: ultrasound assessment.

PURPOSE: Central venous cannulation via the common femoral vein is an important starting point for many interventions. The purpose of this study was to determine the optimum conditions for cannulation of the femoral vein and to compare these with the relative changes in the internal jugular vein. METHODS: High-resolution 2D ultrasound was utilised to determine variability of the calibre of the femoral and internal jugular veins in 10 healthy subjects. Venous diameter was assessed during the Valsalva manoeuvre and in different degrees of the Trendelenburg position. RESULTS: The Valsalva manoeuvre significantly increased the size of the femoral and internal jugular veins. There was a relatively greater increase in femoral vein diameter when compared with the internal jugular vein of 40 and 29%, respectively. Changes in body inclination (Trendelenburg position) did not significantly alter the luminal diameter of the femoral vein. However, it significantly increased internal jugular vein diameter. CONCLUSIONS: Femoral vein cannulation is augmented by the Valsalva manoeuvre but not significantly altered by the gravitational position of the subject.

Adult↗
PubMed2005

Antibacterial potential from Indian Suregada angustifolia.

Phytochemical analysis of the leaves from Indian Suregada angustifolia (Baill. ex Muell. Arg.) Airy Shaw (Euphorbiaceae) resulted in the isolation and identification of six known compounds, viz. friedelin, epi-friedelinol, n-octacosanol, alpha-amyrin, beta-sitosterol and beta-sitosterol-3-beta-D-glucopyranoside. Aqueous (room temperature, boiled and autoclaved) and various solvent (methanol, chloroform and hexane) extracts of leaves were tested against 12 human pathogenic bacteria by the agar well-diffusion method. Aqueous extracts did not express any activity. Antibacterial activity was recorded in the order of methanol, hexane and chloroform extracts. Maximum activity recorded against Staphylococcus aureus (skin infections) in methanol and hexane extracts and moderate activity recorded against diarrhoea causing bacteria, Vibrio vulnificus (hexane extract) and Vibrio cholerae (chloroform extract).

Anti-Bacterial Agents↗
PubMed2004

Direct thrombin injection into aneurysmal sac in a patient with a type II endoleak.

Endovascular grafting of abdominal aortic aneurysms provides a good alternative to open surgery, especially in high-risk patients. Endoleaks are a well-recognized complication and are typically diagnosed on CT. We describe a case in which a patient's endoleak was evaluated by MRI and successfully treated by direct thrombin injection into the site of the leak.

Aged↗
PubMed2002

Antimicrobial and phytochemical studies of Swertia corymbosa.

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.

Anti-Bacterial Agents↗
PubMed2002

Phytochemical and antimicrobial studies of Begonia malabarica.

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.

Anti-Bacterial Agents↗
PubMed2002

Evaluation of chemical disinfectants for the elimination of Salmonella biofilms from poultry transport containers.

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.

Animals↗
PubMed2002

A Markov modulated Poisson process model for rainfall increments.

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.

Environmental Monitoring↗
PubMed2002

Indigoferabietone, a novel abietane diterpenoid from Indigofera longeracemosa with potential antituberculous and antibacterial activity.

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.

Abietanes↗
PubMed2001

IL-3 induces B7.2 (CD86) expression and costimulatory activity in human eosinophils.

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.

Antigen-Presenting Cells↗
PubMed2001

SCAP: a new methodology for safety management based on feedback from credible accident-probabilistic fault tree analysis system.

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.

Accident Prevention↗
PubMed2001

CV706, a prostate cancer-specific adenovirus variant, in combination with radiotherapy produces synergistic antitumor efficacy without increasing toxicity.

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.

Adenoviridae↗
PubMed2001

Glucose-regulated insulin expression in diabetic rats.

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.

Animals↗
PubMed2001

Nutritional potential of biochemical components in Galactia longifolia Benth. (Fabaceae).

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.

Amino Acids↗
PubMed2001

Ultrasound features of blunt testicular injury.

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.

Adolescent↗
PubMed2001

Predicting migration of trace amounts of styrene in poly(styrene) below the glass transition temperature.

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.

Diffusion↗