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Biomedical subjects

S Kumar

Publications and source records attributed to S Kumar.

At least 181 records · Page 10Linked to original sources
PubMed2004

Development of an ideal starch saccharification process using amylolytic enzymes from thermophiles.

The extensive efforts to screen thermophilic fungi and bacteria, isolated from various environmental samples, have resulted in the selection of Thermomucor indicae-seudaticae, Geobacillus thermoleovorans NP33 and G. thermoleovorans NP54 for the production of glucoamylase, amylopullulanase and alpha-amylase, respectively. Submerged and solid-state fermentation processes were optimized for maximizing the secretion of glucoamylase by T. indicae-seudaticae. The production of amylopullulanase and alpha-amylase by NP33 and NP54 in submerged fermentation was also optimized. Glucoamylase was optimally active at pH 7.0 and 60 degrees C and was shown to saccharify soluble as well as raw starches. Amylopullulanase and alpha-amylase exhibited optima at pH 7.0 and 100 degrees C and saccharified starch efficiently. Differential inhibition and action on mixed substrates clearly suggested that there are two separate active sites for alpha-amylase and pullulanase activities of amylopullulanase. Both alpha-amylase and amylopullulanase are high maltose-forming and Ca(2+)-independent. These amylolytic enzymes have been shown to be useful in starch saccharification alone and in combination.

Amyloid↗
PubMed2004

Metabolite pattern of Cysticercus cellulosae metacestode from different predilection sites of swine using proton magnetic resonance spectroscopy.

Cysticercosis due to Taenia solium is one of the most common public health problems in various regions of the world. We have performed prolon magnetic resonance spectroscopy (1H MRS) experiments of the fluid aspirated from cysticerci excised from skeletal muscle (n = 16) and brain (n = 9) of infected swine to compare the metabolite pattern of cysticerci in different predilection sites. Perchloric acid extract of cysticercus cysts excised from skeletal muscles (n = 16) was also prepared to ascertain water-soluble, low molecular weight metabolites using 1H MRS. Absolute quantification and statistical analysis of different metabolites was done to look for any significant differences in different locations of cysts. The metabolite pattern of cysticerci was found to be similar in the various predilection sites. Metabolites observed were leucine, valine, alanine, lysine, glycine, lipid contents, lactate, glutamate, acetate, succinate, creatine, choline, and glucose. Concentration of creatine in cysticercus fluid of cysts removed from the muscle was found to be significantly higher (p = 0.001) than the cysts located in the brain. We conclude that the metabolite pattern in the cysticerci is not influenced by the surrounding tissue location; however concentration of certain metabolites may depend upon the tissue location.

Animals↗
PubMed2004

Studies on immunocompetence status in two turkey varieties in India.

(1) Two hundred and twenty-seven adult turkeys of both sexes, of two varieties (104 Black and 123 White) were used to evaluate their immunocompetence status and body weights. (2) Response to sheep red blood cells (SRBC) (humoral immunity) was measured by Haemagglutination (HA) test 5 days post immunisation (dpi) and expressed as log2 values. Mercaptoethanol resistant (MER) antibodies representing IgG were determined by Mercaptoethanol HA test and Mercaptoethanol sensitive (MES) antibodies, representing IgM as the difference in total HA titre and IgG. Serum lysozyme concentrations were estimated by 'Lysoplate assay' and expressed in log2 values. (3) Least squares analysis of variance revealed that the White variety had higher adult body weight (4.788 +/- 0.040 kg) than the Black (3.774 +/- 0.044 kg). Sexual dimorphism was apparent and meals were heavier than females in both varieties. The interaction effect of variety and sex on body weight was also significant. (4) Least squares means for immunological traits, namely, total anti-SRBC antibodies, MER, MES titres and serum lysozyme were 7.161 +/- 0.189, 0.801 +/- 0.071, 6.362 +/- 0.160 and 1.766 +/- 0.043 microg/ml, respectively. The Black variety had a higher MES antibody titre than the White. (5) Sex had an effect on all the immunological traits except on MER titres. Females generally had higher anti-SRBC, MER and MES titres and serum lysozyme. The variety x sex interaction effect was significant for MES titres and serum lysozyme. White males had the lowest MES titres.

Animals↗
PubMed2004

Transfection of human tumour cells with Mre11 siRNA and the increase in radiation sensitivity and the reduction in heat-induced radiosensitization.

Double-strand DNA breaks (DSBs) are potentially lethal DNA lesions induced by ionizing radiation. In eukaryotes, DSBs can be repaired by homologous recombination (HR) or non-homologous end-joining (NHEJ). DNA repair protein Mre11 participates in both the NHEJ and HR DNA repair pathways. Hyperthermia has been used clinically as a radiosensitizer. However, the mechanisms by which radiosensitization is induced by hyperthermia, especially moderate hyperthermia (41 degrees C) are not fully understood. Previous studies suggest that 41 degrees C reduces the nuclear Mre11 protein level in a manner that correlates with heat-induced changes in radiation sensitivity. Therefore, siRNA technology was used in the present study to reduce Mre11 gene expression to determine if reduced Mre11 protein levels induced radiosensitization and if such radiosensitization is similar to that induced by moderate hyperthermia. The results show that (1) the cellular level of the Mre11 protein was reduced about 60 +/- 18% by a 24-h treatment with siRNA. Results from the Mre11 protein turnover assay showed a half-life of 11.6 +/- 0.5 h for the Mre11 protein, which is consistent with reduction in protein level in 24 h after Mre11 siRNA treatment assuming a delay of 4-8 h to reduce RNA levels. After 48 h in siRNA, cellular Mre11 protein levels increased to approximately pretreatment levels. NSY cells were sensitized to ionizing radiation after 24 h of treatment with Mre11 siRNA. Two hours at 41 degrees C did not increase the radiation sensitivity of cells with a reduced Mre11 protein level following a 24-h siRNA treatment. These data support the conclusion that the DSB repair protein, Mre11, appears to be a target for radiosensitization by moderate hyperthermia.

Adenocarcinoma↗
PubMed2004

Production of monoclonal antibodies against a 19-kD recombinant Plasmodium vivax MSP1 for detection of P. vivax malaria in Turkey.

Plasmodium vivax malaria, which is transmitted to humans by mosquitoes, is one of the most important parasitic diseases in Turkey. The major protein on the surface of asexual erythrocytic stage merozoites of P. vivax (Pv) is 200 kD and called major merozoite surface protein-1 (PvMSP1). Polyclonal antibodies against the 19-kD C-terminal fragment of PvMSP1 (PvMSP1(19)) are protective in monkey models of P. vivax and associated with protection in field studies. In this research, monoclonal antibodies were produced against PvMSP1(19). A total of 214 IgG(1) antibody-releasing hybridomas were obtained and three monoclonal antibodies were produced (PvMSP1(19).1, PvMSP1(19).2, and PvMSP1(19).3) and selected for further study. They have now been purified from ascitic fluid on a Staphylococcus protein A affinity column. These are the first monoclonal antibodies produced against P. vivax in Turkey and the first monoclonal antibodies produced against this recombinant PvMSP1(19) in the world. The monoclonal antibodies will be used to study the epidemiology of P. vivax in patients with malaria in Turkey, and to develop better strategies for early diagnosis and treatment of the disease in our population.

Animals↗
PubMed2004

'MYNI's orthosis': a self-adjustable, dynamic knee extension orthosis for quadriceps weakness in haemophilia rehabilitation.

In developing countries like India, where walking is the primary, preferred and feasible mode of transport, the implications following quadriceps weakness poses a serious threat to ones functional independence. This has been a challenge for professionals while ambulating individuals with haemophilia, where quadriceps weakness is very common. Although external splinting has been understood for many years, as a means of support in haemophilia, there is still a dearth of knowledge in making an appropriate splint to assist or to take over the weak quadriceps during ambulation. This newly designed 'MYNI's orthosis' helps in versatile ways in addition to assisting the weak quadriceps. It provides prolonged stretch to contracted tissue, allows for being used as a serial cast in improving the knee range and is cosmetically acceptable. Above all, it is user-friendly, thus enhancing compliance and superior outcome in haemophilic knee rehabilitation.

Developing Countries↗
PubMed2004

Dose and outcome of care in haemophilia--how do we define cost-effectiveness?

Severe haemophilia (factor [F]VIII/FIX activity < 0.01 IU mL(-1)) is characterized by repeated haemarthroses resulting in severe arthropathy in adulthood. In 1958, Professor Nilsson in Sweden introduced prophylactic infusions with clotting factor concentrates at regular intervals in order to maintain clotting factor levels above 0.01 IU mL(-1) and to prevent bleeding. Since then, evidence of the long-term beneficial effects of prophylactic treatment for severe haemophilia has been increasing and it has become the recommended treatment strategy for children with severe haemophilia by both the World Health Organization and the US National Hemophilia Foundation Medical and Scientific Advisory Committee. However, the implementation of this recommendation has been hampered by issues of cost and venous access. The high costs of prophylaxis have largely prevented its use in major parts of the world. The question therefore is whether the current models of replacement of clotting factor concentrates, while certainly being effective, are also optimal. Can the data on outcome at different levels of factor replacement be used to assess their cost-effectiveness?

Adolescent↗
PubMed2004

Association of simple anthropometric measures of obesity with visceral fat and the metabolic syndrome in male Caucasian and Indo-Asian subjects.

AIMS: The aims of this study were first, to investigate the relationship between simple anthropometric measures of obesity with visceral fat as assessed by a single slice magnetic resonance imaging (MRI)-scan in patients attending a hospital clinic. Second, to determine which anthropometric measure best relates to the adverse metabolic profile of the metabolic syndrome. METHODS: Forty-one male subjects [body mass index (BMI): 30.2 + 5.8 kg/m(2), age: 50.3 + 13.6 years] were studied by MRI-scan to measure visceral fat at L4/L5 level and to investigate its relationship with simple anthropometric measures. Second, we studied 83 male subjects to determine which anthropometric measure best predicts the metabolic complications (using the ATPIII criteria) of obesity in the setting of a hospital clinic. RESULTS: Waist circumference was the best anthropometric measurement that correlated with MRI-visceral fat mass assessed at L4/L5 in 41 subjects who had an MRI scan (P = 0.0001, r(2) = 0.36, beta = 0.56) amongst variables which also included age, BMI, sagittal diameter, diabetes and ethnicity. Stepwise multiple regression analysis showed sagittal diameter (P = 0.001, r(2) = 0.4, beta = 0.406), age (P = 0.003, beta = 0.271) and waist circumference (P = 0.012, beta = 0.297) were the best predictors of the adverse metabolic profile of the metabolic syndrome in all 83 male subjects amongst BMI, waist-hip ratio (WHR), ethnicity and diabetes-related factors. CONCLUSIONS: Waist circumference is a simple anthropometric parameter that best correlates with single slice MRI-scan, but sagittal diameter (measured using abdominal calipers) better predicts the adverse metabolic profile of the metabolic syndrome. Although there is considerable variation in abdominal fat topography between ethnic groups, and also within populations, sagittal diameter assessment is a technique that is simple and best predicts the metabolic syndrome.

Adult↗
PubMed2004

Evaluation of delivery of enhanced diabetes care to patients of South Asian ethnicity: the United Kingdom Asian Diabetes Study (UKADS).

AIMS: We tested the hypothesis that enhanced care for diabetes, tailored to the needs of the South Asian community with Type 2 diabetes, would improve risk factors for diabetic vascular complications and ultimately reduce morbidity and mortality. PATIENTS AND METHODS: The study was a cluster randomized controlled trial (RCT) with general practice the unit of randomization. Six West Midlands general practices with a high proportion of South Asian patients were randomized to 'enhanced care' using Asian link workers and extra community diabetes specialist nurse sessions (intervention) or continued standard practice care (control). RESULTS: Of 401 patients recruited to the study, 361 (90%), comprising 178 from Coventry and 183 from Birmingham were eligible and included in the analyses. The mean age at baseline (standard deviation, SD) was 58.9 (11.7 years) with median (interquartile range; IQR) duration of diabetes 6.5 (3-11) years. At one year follow-up there was a significant difference in reduction of systolic (4.6 mmHg, P = 0.035) and diastolic blood pressure (3.4 mmHg, P = 0.003) and total cholesterol (0.4 mmol/l, P = 0.005), comparing the intervention and control groups. After adjusting for baseline measurement and age, only differential reduction in diastolic blood pressure remained significant. There was no significant change in HbA(1c) and no difference between the groups. CONCLUSIONS: Using link workers and extra community diabetes specialist nurse input together with treatment protocols in primary care might prove a useful strategy in working towards NSF targets for diabetes management. In this study, small reductions in blood pressure and cholesterol were achieved. Improvement in glycaemic control may require longer and possibly different strategies. Further research is required to evaluate fully the effectiveness, including the costs and longer term sustainability of culturally sensitive initiatives.

Aged↗
PubMed2004

Long-term follow-up after pneumatic dilation for achalasia cardia: factors associated with treatment failure and recurrence.

BACKGROUND: Though most patients with achalasia cardia (AC) respond to pneumatic dilation (PD), one-third experienced recurrence. Long-term follow-up studies on factors associated with various outcomes are scanty. METHODS: In this retrospective study, 126 patients (36.5 +/- 14.6 yr, 76 male) with AC (diagnosed by esophagoscopy, barium esophagogram, and/or manometry) were followed up in person or through mail. The median dysphagia-free duration was calculated by Kaplan-Meier analysis. Factors associated with nonresponse and recurrence after PD were determined using univariate and multivariate analyses. RESULTS: Symptoms were dysphagia (126, 100%), chest pain (21, 17%), regurgitation (61, 48%), weight loss (33, 26%), and pulmonary symptoms (23, 18%); 5 of 126 (4%) had megaesophagus (> or =7 cm). The mean lower esophageal sphincter (LES) pressure was 38.7 +/- 16.8 mmHg. One hundred and fifteen of 126 (91%) patients responded to PD (90 (71%) to first session); 25 of these had recurrence of dysphagia after 15 +/- 17 months. Post-PD chest pain requiring hospitalization occurred in 21 of 126 (17%; one had an esophageal perforation). Post-PD LES pressure, which was assessed in 48 of 126 patients, had decreased by >50% from baseline in 14 of 29 responders, 0 of 11 nonresponders (p= 0.004, chi(2) test), and 5 of 8 relapsers. The median dysphagia-free duration by Kaplan-Meier analysis was 60 months (SE 2.7, 95% CI 54.7-65.3). On univariate analysis, male gender, pulmonary symptoms (nocturnal coughing spell, history of respiratory infection), absence of chest pain, and failure to achieve a reduction in LES pressure >50% after PD were associated with poor outcome; whereas age, grade of dysphagia, regurgitation, megaesophagus, and LES pressure before PD were not. Male gender was associated with poor outcome by multivariate-analysis. CONCLUSIONS: PD is an effective and safe treatment for AC. Post-PD LES pressure measurement may be helpful in assessing response. Male patients have poorer outcomes following PD.

Adolescent↗
PubMed2004

Measuring disordered personality functioning: to love and to work reprised.

OBJECTIVE: Current limitations to diagnosing and measuring the personality disorders encouraged a set of studies seeking to provide an alternate approach to modeling and measuring disordered personality function. METHOD: A large set of self-reported descriptors of disordered personality function were factor analyzed in a sample of patients with clinician-diagnosed personality dysfunction, generating 11 lower-order and two higher-order constructs. Subjects and non-clinical controls also completed a measure of personality styles underpinning formalized personality disorder groupings. Properties of the refined self-report (SR) measure were assessed in an independent sample of patients with a clinically diagnosed personality disorder. RESULTS: Limitations in 'cooperativeness' and 'coping' formed the higher-order constructs defining disordered personality function, with these constructs relevant to all personality styles. Analyses of SR, corroborative witness (CW) and clinician-rated data in an independent sample supported measuring disordered personality function by our derived 20-item SR measure, and exposed limitations to clinician-based assessment. CONCLUSION: Study findings build to a multi-axial strategy for measuring personality disorder, involving separate dimensional assessment of both disordered personality function and of personality style.

Adaptation, Psychological↗
PubMed2004

Variations in the insecticide-resistance spectrum of Anopheles stephensi after selection with deltamethrin or a deltamethrin-piperonyl-butoxide combination.

When the larvae of Anopheles stephensi, a malaria vector, were selected with deltamethrin for 40 successive generations, there was a 60-fold increase in larval resistance to deltamethrin but no increase in the resistance of the adult mosquitoes. This result, and the observation that deltamethrin selection of adults for 40 generations resulted in only a six-fold increase in adult resistance to deltamethrin, indicated some stage specificity. When F(24) deltamethrin-resistant larvae were selected with 1:5 deltamethrin-piperonyl butoxide (deltamethrin-PBO), instead of deltamethrin alone, for 16 generations, the level of resistance to deltamethrin in the F(40) larvae was reduced by 6%-21%. Similarly, selection with deltamethrin-PBO of adults of the parental strain for 20 generations reduced the speed of the development of resistance to deltamethrin, compared with that seen using selection with deltamethrin alone. Deltamethrin selection appears to select initially a monooxygenase-based mechanism. When the monooxygenase-based mechanism is blocked, by treatment with PBO, selection of a kdr-type mechanism is accelerated, as is evident from increased cross-resistance to 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) in the adults selected with deltamethrin-PBO. The implications of these results are discussed in terms of the management of the larval and adult stages of An. stephensi .

Animals↗