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Biomedical subjects

V Viswanathan

Publications and source records attributed to V Viswanathan.

At least 19 recordsLinked to original sources
PubMed2006

Fish venom (Pterios volitans) peptide reduces tumor burden and ameliorates oxidative stress in Ehrlich's ascites carcinoma xenografted mice.

The present study was carried out to assess the effect of Pterios volitans venom (mixture of peptides) on Ehrlich's ascites carcinoma (EAC) and its influence on antioxidant status in the liver. Among six groups of albino mice, three were treated with sublethal doses of venom, along with the standard drug, 5-fluorouracil. In EAC-bearing mice, mean life span and antioxidants were significantly decreased, whereas, body weight, tumor volume, viable tumor cell count, lipid peroxidation and expression of proliferating cell nuclear antigen were significantly increased. These changes were brought back to near normal in treatment groups. The findings are further confirmed by histopathological observations.

Animals↗
PubMed2006

High energy density processing of a free form Nickel-alumina nanocomposite.

The development of a free form bulk Nickel reinforced Alumina matrix nano composites using Air Plasma Spray and laser processing has been presented. The process consumes less time and requires further minimal machining and therefore is cost effective. The relative differences in using APS over laser processing in development of bulk metal-ceramic nanocomposites have been discussed. The process intricacies involved during processing such as material specific mandrel selection, plasma-particle interaction are highlighted. Electroless coating has been used to uniformly disperse Nickel in alumina matrix as a source material. The electroless Ni coated alumina particles are subjected to both laser processing and Air Plasma Spraying with optimized parameters. Consolidation by laser processing could not be achieved as the laser beam was reflective to Nickel. On the other hand, APS Ni-alumina nanocomposite with a cylindrical shape of 1.2" OD x 1" ID x 1.5" length has been fabricated with minimum or no surface defects. HRTEM pictures revealed the nanostructure retention thereby corroborating the fact that bulk nanostructures can be made using Air Plasma Spray. XRD analysis confirmed the phase transformation from alpha alumina to gamma alumina and oxidation of Ni to NiO. Subsequent reduction of NiO to metallic nickel using hydrogen atmosphere has also been demonstrated. Mechanical properties such as, hardness (1025 HV) and fracture toughness (5 MPa m1/2) for the nanocomposite are presented herein.

Aluminum Oxide↗
PubMed2005

Percutaneous closure of iatrogenic femoral arteriovenous fistula using endovascular covered stent.

Local complications after femoral arterial catheterization, such as hematomas, pseudoaneurysms, arteriovenous fistulas (AV fistulas), and arterial occlusions, are becoming more common, with the growing number of complex invasive procedures being undertaken, especially in older and sicker patients. Newer percutaneous techniques are being developed to treat these. Covered stents are an effective, safe, and less invasive way to deal with pseudoaneurysms and AV fistulas. This case report highlights the application of this technique to treat an iatrogenic femoral AV fistula in a 69 years male.

Aged↗
PubMed2005

Profile of diabetic foot complications and its associated complications--a multicentric study from India.

AIM: The aims of this study were to determine. The prevalence of foot complications such as neuropathy, peripheral vascular disease (PVD), amputations and infections and the associated diabetic complications and practice of foot care among these subjects. METHODS: A total of 1319 type 2 diabetic patients, were selected from four different centres across India. The centres were Diabetes Research Centre (DRC), Chennai, Government Rajaji Hospital (GRH), Madurai, Christian Medical College (CMC), Vellore and All India Institute of Medical Science (AIIMS), Delhi. Details were collected regarding foot problems and associated complications. RESULTS: The prevalence of neuropathy was 15% (n=193) and PVD was 5% (n=64). Infections were present in 7.6% (n=100) of patients. The infection rate varied from 6-11% in the different centres. Nearly 3% of subjects had undergone a minor or major amputation. DISCUSSION: This study found that the prevalence of infection was 6-11% and prevalence of amputation was 3% in type 2 diabetic patients. Neuropathy (15%) was found to be an important risk factor for diabetic foot infections. Effective foot care advice should be propagated to reduce the burden imposed by diabetic foot complication particularly in developing countries like India.

Adult↗
PubMed2004

Regional differences in risk factors and clinical presentation of diabetic foot lesions.

BACKGROUND: Problems associated with the diabetic foot are worldwide. However, there may be regional variation among risk factors and clinical presentation. Prospective comparative data concerning this topic are rare. AIM: To determine differences in underlying risk factors and clinical presentation of foot problems among people with diabetes in different regions. PATIENTS AND METHODS: Six hundred and thirteen consecutive patients with diabetic foot lesions from three centres [Soest-Germany (GER), Dar-es-Salaam, Tanzania (TAN) and Chennai, India (IND)] were included during the period June 1998 through December 1999. Diabetes-related data, risk-factor profiles, and lesion-related data were collected for each patient. Due to varying proportions of recurrent lesions among the centres, only data from patients with newly presenting diabetic foot lesion were analysed. RESULTS: Of the 613 patients sampled, 368 (60%) were treated for newly presenting diabetic foot lesion. In all three centres, patients were predominately male and had Type 2 diabetes. The average diabetes duration until the onset of the initial foot lesion was 14 years in GER and 12 years in IND, but only 5 years in TAN. The corresponding patient ages were 71, 56 and 51 years. Neuropathy was common to patients in all three centres. Peripheral vascular disease (PVD) was a frequent risk factor in GER (48%). In TAN and IND it was far less common (12 and 13%), probably due to younger patient populations, shorter diabetes duration and lower proportions of smokers. Inadequate footwear was the most common cause of foot lesions in GER (19%), while lack of footwear, irregular foot care and burns were the primary precipitating factors among patients in TAN and IND. CONCLUSION: Similarities in different regions of the world among people with diabetes suffering newly presenting foot lesions include a predominance of males and patients with Type 2 diabetes, as well as a high frequency of diabetic neuropathy. However, differences concerning age, diabetes duration, peripheral vascular disease, and precipitating factors contributing to injury are also observed.

Adult↗
PubMed2004

Impact of Joint National Committee VII recommendations on diabetic microvascular complications.

AIMS AND OBJECTIVE: To determine the impact of the Seventh Report of the Joint National Committee recommendations on microvascular complications in South Indian type 2 diabetic patients. MATERIAL AND METHODS: In this study, 457 type 2 diabetic patients and 500 age-matched healthy control subjects, with no history of hypertension were enrolled. Based on blood pressure measurements, they were assigned as Group I: Normal (SBP < 120 and DBP < 80 mmHg); Group II: Prehypertension (SBP 120-139 or DBP 80-89 mmHg); Group III: Stage I hypertension (SBP 140-159 or DBP 90-99 mmHg) and Group IV: Stage II hypertension (SBP > or = 160 or DBP > or = 100). RESULTS: Blood pressure readings in controls and diabetics were: normal in 46.8% and 16.2% (chi2 = 101.1, p < 0.0001), prehypertension in 33.2% and 52.5% (chi2 = 35.7, p < 0.0001), stage I hypertension in 15.2% and 26.3% (chi2 = 17.3, p < 0.0001), stage II hypertension in 4.8% and 5% respectively. Prevalence of retinopathy increased with increasing incidence of hypertension (trend chi2 = 10.7, p < 0.01). In the multivariate analysis, cholesterol was associated with prehypertension, and cholesterol and family history of hypertension were associated with stage I hypertension. Albuminuria, family history of hypertension and serum triglycerides were associated with stage II hypertension. CONCLUSION: More than half of the diabetic subjects were prehypertensives. As expected prevalence of other complications increased with increasing levels of blood pressure. This emphasizes the need to have regular check up for hypertension to reduce the morbidity from other complications.

Advisory Committees↗
PubMed2002

Early recognition of diabetic neuropathy: evaluation of a simple outpatient procedure using thermal perception.

OBJECTIVE: To determine the effectiveness of Tip-therm, a temperature discriminator, in making an early diagnosis of distal symmetrical polyneuropathy in diabetic patients and to compare its effectiveness with the Semmes-Weinstein monofilament and biothesiometry, which are established methods of diagnosing neuropathy in diabetic patients. PATIENTS AND METHODS: From the diabetic subjects who came to the hospital for review, 910 consecutive cases were selected. All were tested with the Semmes-Weinstein monofilament (10 g monofilament) and biothesiometry and also by using the Tip-therm for comparison. RESULTS: Out of the 241 patients who had no sensation to the monofilament only four (1.7%) felt Tip-therm whereas 237 (98.3%) patients could not feel Tip-therm. Among 298 patients diagnosed as having neuropathy by biothesiometry, only eight (2.7%) patients exhibited sensation with Tip-therm while 290 (97.3%) patients could not feel it. CONCLUSION: A simple device, Tip-therm, which tests for temperature discrimination, was compared with two validated methods for detection of neuropathy-a monofilament and biothesiometry. Tip-therm appears to be an inexpensive, highly sensitive, and specific device for detection of diabetic neuropathy when compared with biothesiometry and a monofilament.

Ambulatory Care↗
PubMed2002

Prevalence of pathogens in diabetic foot infection in South Indian type 2 diabetic patients.

AIM: To determine the prevalence of pathogens in diabetic foot infections, in relation to parameters like Wagner's grading, duration of diabetes and healing time. MATERIAL AND METHODS: A group of 654 (M:F, 433:221) type 2 diabetic patients with foot ulcers were studied. Specimens like pus, wound exudate and tissue were processed for smear for Gram's staining, aerobic and anaerobic culture, and biochemical identifications. RESULTS: In 654 diabetic patients, 728 pathogens were isolated. Aerobic pathogens were isolated in 437 (66.8%) patients and anaerobic pathogens were isolated in 217 (33.2%). As Wagner's grading increased, the prevalence of anaerobic pathogens also increased. Neuropathy was common in diabetic patients infected with both aerobic and anaerobic pathogens. Ulcers infected with anaerobic pathogens showed a longer healing time than ulcers infected with aerobic pathogens. There was no significant difference in peripheral vascular disease (PVD) in patients selected for the study. Among aerobic pathogens, Enterobacteriaceae family (48%), Staphylococcus species (spp) (18.2%), Streptococcus spp (16.8%) and Pseudomonas spp (17%) were seen frequently. Among anaerobes Peptostreptococcus spp and Clostridium spp formed 69.4%. Gram-negative anaerobes like Bacteroides spp and Fusobacterium spp were present in 30.6%. Healing time was longer when strict aerobic pathogen Pseudomonas spp and strict anaerobic pathogens were present (136.1 +/- 28.6 and 136.4 +/- 34.7 days, respectively). CONCLUSIONS: Diabetic foot infection is polymicrobial in nature. The healing time of wound infected with anaerobic pathogens was higher than those infected with aerobic pathogens. Anaerobic pathogens increased with the Wagner's grading. Presence of neuropathy increased the risk of foot infection.

Bacteria, Aerobic↗
PubMed2002

Is increased apolipoprotein B-A major factor enhancing the risk of coronary artery disease in type 2 diabetes?

OBJECTIVES: An association of Apolipoprotein B (Apo B) with coronary artery disease (CAD) independent of LDL cholesterol (LDLc) concentrations has been reported in white population. This analysis was taken up to study whether the higher CAD risk in Asian Indians with diabetes could be explained by possible alterations in Apo B and Apolipoprotein A1 (Apo A1) concentrations. METHODS: The study group consisted of four hundred and forty seven men aged > or = 25 years, 167 with CAD and 280 with no CAD, classified by coronary angiography. Plasma lipid profile including total cholesterol, LDLc, Apo A1 and Apo B were done. Glucose tolerance was evaluated in all. RESULTS: Age, BMI, Apo B, and Apo A1 were significantly associated with CAD in a multiple regression analysis. Hyper Apo B was more common than hyper LDLc in CAD (73.6% vs 20.4%, chi2 = 157, P < 0.001). Apo B concentrations were increased in diabetic subjects even in the presence of normal levels of LDLc and in the absence of CAD. CONCLUSIONS: The study has shown that the apolipoproteins B and A1 provide better information regarding the risk of CAD. Apo B abnormalities exist in large percentages of CAD subjects despite having normal levels of LDLc. Diabetes per se enhances the Apo B concentrations and this could probably be one of the mechanisms of accelerated CAD in diabetes. Hyper Apo B may be an index of CAD risk.

Adult↗
PubMed2002

Plasma homocysteine concentration and coronary artery disease in Asian Indians.

OBJECTIVE: This study was done (a) to evaluate the relationship between the plasma total homocysteine (tHcy) levels and coronary artery disease (CAD) in Asian Indians and (b) to see the relationship between tHcy and glucose intolerance. METHODS: Fasting concentrations of plasma tHcy was measured in 137 men, aged > or = 25 years who underwent coronary angiography while investigating for chest pain. Among them 71 had no CAD and 66 had CAD. Fasting plasma glucose (FPG) and glycosylated haemoglobin (HbA1c) were estimated. Total Hcy was measured using the Elisa method (Axis Biochemicals ASA-Oslo, Norway) in fasting EDTA plasma. RESULTS: The subjects with CAD were significantly older but had similar body mass index (BMI), waist-hip ratio (WHR), FPG and HbA1c values compared with the non-CAD subjects (P < 0.001). The median tHcy and the percentages of abnormal values were similar in non-CAD and CAD groups. No significant differences were seen in the four subgroups with respect to the mean tHcy or the percentage of abnormal values. The highest tHcy values were seen in the non-diabetic, non-CAD group (group 1--control). CONCLUSION: This preliminary data indicates that tHcy concentrations are not elevated in subjects with CAD and probably there is no association between total homocysteine and CAD in Indians. Homocysteine values were not influenced by the glucose tolerance status. Measurement of homocysteine concentrations may be more appropriate when the blood levels of vitamin B12 and folate are also measured.

Adult↗
PubMed2002

Persistent microalbuminuria in type 1 diabetic subjects in South India.

AIM: There are only a few reports on the prevalence of microalbuminuria (MAU) in type 1 diabetic subjects in India. This study was done to assess the prevalence of MAU in South Indian diabetic subjects. MATERIAL AND METHODS: MAU was estimated by measuring albumin/creatinine ratio in an early morning urine sample on three occasions using immunoturbidimetry (> 30 microg albumin/mg creatinine) in South Indian patients. Kidney function tests were done in 95 type 1 DM, (M:F, 56:39). Persistent proteinuria was detected in 17 (17.9%) and they were excluded from the study. Further details were taken only in the remaining 78 subjects. Persistent MAU was seen in 22 (28.2%) and other 56 subjects had normoalbuminuria (NAU) (71.8%). RESULTS: There was no significant difference in the age, duration of DM and the average HbAlc between MAU and NAU. MAU developed at the age of > or = 20 years, even in subjects with onset of diabetes at a younger age. Diabetic retinopathy was present in 3 (13.6%) and ECG abnormalities were seen in one patient with MAU. None of the subjects in NAU group had these abnormalities. Prevalence of MAU increased with increasing duration of diabetes, MAU was present in 3 patients (10.3%) with duration of diabetes < or = 5 years, in five patients (23.8%) with duration of diabetes> 5 to < or = 10 years and in 14 (50%) patients with duration of diabetes > 10 years. Hypertension was present in 5 (22.7%) of MAU and only in one subject with NAU. CONCLUSION: It is observed that MAU occurs in type 1 diabetes after the age of 20 years and it is present in a large proportion of the study subjects.

Adolescent↗
PubMed2001

Risk variables for coronary artery disease in Asian Indians.

No large study from India has addressed the association of risk variables with coronary artery disease (CAD) in angiographically proved cases. In this study, we analyzed the association of anthropometric variables, lipoproteins, and coagulation parameters with CAD in those cases proved by coronary angiography. A cross-sectional study of 447 men > or = 25 years old, classified as with CAD or without CAD, was performed. Men treated with aspirin or lipid-lowering agents, and those with renal, hepatic, or thyroid diseases were excluded. Associations of these variables with CAD were evaluated by univariate and multiple logistic regression analyses. The effect of diabetes on the CAD profile was also analyzed. Prevalences of diabetes and hypertension were significantly higher among those with CAD (p <0.001 for both). Lipid profile abnormalities, except lipoprotein (Lp(a)), were associated with CAD. Antibodies to oxidized low-density lipoprotein was higher in patients with CAD. Fibrinogen levels were higher in CAD, but plasminogen activator inhibitor-1 did not show an association with CAD. In the multiple logistic regression analysis, age, body mass index, very-low-density lipoprotein cholesterol, total to high-density lipoprotein cholesterol ratio, and fibrinogen showed significant independent association with CAD. Several lipid abnormalities were associated with CAD in Asian Indians, but no significant association was seen with Lp(a) levels.

Adult↗
PubMed2001

Association of proinsulin and insulin resistance with coronary artery disease in non-diabetic south Indian men.

AIMS: To evaluate the association of plasma proinsulin and insulin resistance (IR) with coronary artery disease (CAD) in non-diabetic subjects. METHODS: In this case control study, 41 normoglycaemic men with angiographic evidence of CAD were compared with 41 control men matched for age and glycaemia and with no history or evidence of cardiac diseases. Estimations of plasma glucose, lipids, fasting plasma specific insulin (SI) and proinsulin (PI) were performed. IR was calculated by the homeostasis model assessment (HOMA) method. Multiple logistic regression analysis was performed to test the association of the variables with the prevalence of CAD. RESULTS: Subjects with CAD had a higher body mass index (BMI) (25.4 +/- 4.3 vs. 22.9 +/- 3.2 kg/m2, P = 0.003) and waist to hip ratio (WHR) (0.95 +/- 0.05 vs. 0.89 +/- 0.09, P = 0.001) and a lower high-density lipoprotein (HDL) cholesterol level (0.97 +/- 0.2 vs. 1.1 +/- 0.2 mmol/l, P = 0.002). They also had higher mean SI values (107.5 vs. 62.3 pmol/l, P = 0.002), PI values (19.3 vs. 5.7 pmol/l, P < 0.0001), PI/SI ratios (21.4 vs. 10.3, P < 0.0001) and HOMA IR (4.2 vs. 2.4, P = 0.004) compared with non-CAD subjects. These variables were associated with CAD in the unadjusted multiple regression analysis. In the multiple regression with the forward entry of the variables, WHR and PI only showed independent association with CAD. CONCLUSIONS: Subjects with CAD had higher levels of obesity and WHR. CAD showed an association with low HDL cholesterol, circulating PI, PI/SI ratios and IR.

Body Constitution↗