Showing papers by "Rajesh Kumar published in 2002"

Gamma-ray attenuation coefficients in bismuth borate glasses

Abstract: Mass attenuation coefficients of glasses in the system: xBi2O3(1−x)B2O3 (x=0.30, 0.35, 0.40, 0.45 and 0.55) were determined at 356, 662, 1173 and 1332 keV photon energies using a narrow beam transmission method. Appreciable variations were observed in these coefficients due to changes in the chemical composition of glasses. These coefficients were then used to determine effective atomic numbers of glass samples, which were found to be constant with bismuth concentration and energy.

Method and apparatus for providing immersive surveillance

Abstract: A method and apparatus (102) for providing immersive surveillance wherein a remote security guard (122) may monitor a scene (100) using a variety of imagery sources (108, 110, 112, 114) that are rendered upon a model to provide a three-dimensional conceptual view of the scene. Using a view selector (120), the security guard may dynamically select a camera view to be displayed on his conceptual model, perform a walk through of the scene, identify moving objects and select the best view of those moving objects and so on.

Enhanced word clustering for hierarchical text classification

Abstract: In this paper we propose a new information-theoretic divisive algorithm for word clustering applied to text classification. In previous work, such "distributional clustering" of features has been found to achieve improvements over feature selection in terms of classification accuracy, especially at lower number of features [2, 28]. However the existing clustering techniques are agglomerative in nature and result in (i) sub-optimal word clusters and (ii) high computational cost. In order to explicitly capture the optimality of word clusters in an information theoretic framework, we first derive a global criterion for feature clustering. We then present a fast, divisive algorithm that monotonically decreases this objective function value, thus converging to a local minimum. We show that our algorithm minimizes the "within-cluster Jensen-Shannon divergence" while simultaneously maximizing the "between-cluster Jensen-Shannon divergence". In comparison to the previously proposed agglomerative strategies our divisive algorithm achieves higher classification accuracy especially at lower number of features. We further show that feature clustering is an effective technique for building smaller class models in hierarchical classification. We present detailed experimental results using Naive Bayes and Support Vector Machines on the 20 Newsgroups data set and a 3-level hierarchy of HTML documents collected from Dmoz Open Directory.

PAX genes in development and disease: the role of PAX2 in urogenital tract development.

Abstract: PAX genes play an important role in fetal development. Moreover, heterozygous mutations in several PAX genes cause human disease. Here we review the role of PAX2 in kidney development, focusing on the morphological effects of PAX2 mutations. We discuss the role of PAX2 in the context of an inhibitory field model of kidney branching morphogenesis and summarize recent progress in this area.

Significant Impact of Promoter Hypermethylation and the 540 C>T Polymorphism of CDKN2A in Cutaneous Melanoma of the Vertical Growth Phase

Abstract: Promoter hypermethylation, mutations, and loss of heterozygosity in the CDKN2A gene as well as polymorphisms at the 3′-untranslated region were determined in vertical growth phase melanomas. Methylation-specific polymerase chain reaction in soluti and in situ showed that 19% of the cases were hypermethylated at the CDKN2A promoter region, and some of these cases were heterogeneous with both methylated and unmethylated tumor cells. Methylation was associated with increased tumor cell proliferation by Ki-67 expression (P = 0.01) and decreased patient survival (P = 0.025). Point mutations in CDKN2A were found in 4% of the cases, whereas 90% had loss of heterozygosity at one or more of 4 markers studied. Furthermore, presence of the 540 C>T polymorphism at the 3′-untranslated region of CDKN2A (23%) was associated with improved survival in multivariate analysis (hazard ratio, 2.6; P = 0.02). Our results suggest that promoter methylation of the CDKN2A gene is present in a subgroup of the tumors and associated with increased tumor cell proliferation and reduced survival. Further, the 540 C>T polymorphism might define a distinct subgroup of low-grade vertical growth phase melanomas. These findings support a significant role of the CDKN2A gene in melanoma progression.

Genetic status of cell cycle regulators in squamous cell carcinoma of the oesophagus: the CDKN2A (p16INK4a and p14ARF) and p53 genes are major targets for inactivation

Abstract: We determined inactivation of the CDKN2A (p16(INK4a) and p14(ARF)) gene in 21 cases of oesophageal squamous cell carcinoma (OSCC). The tumours were also analysed for mutations in exons 5-8 and allelic losses in the p53 gene. In addition, we screened the CDKN2B (p15 INK4b), CDKN2C (p18 INK4c), CDK4 and p53R2 genes for mutations in the tumour tissues. Besides concomitant alterations in the CDKN2A and p53 loci in more than half of the cases, our results showed that in 18 OSCC (86%) the CDKN2A (p16(INK4a) and p14(ARF) ) gene was affected through mutations, homozygous/hemizygous deletions and promoter hypermethylation. Eight out of 10 tumours with mutations or promoter hypermethylation specific to the CDKN2A/p16 INK4a gene showed loss of the wild-type allele. One tumour with a single base deletion in the N-terminus (codon 8) of the CDKN2A/p16(INK4a) gene carried a novel germ-line mutation or a rare polymorphism (Ile51Met) in exon 2 of the CDK4 gene. Promoter hypermethylation in the CDKN2A/p14 ARF gene was detected in 11 tumours. In the p53 gene 15 mutations were detected in 14 tumours. We detected an inverse relationship between CDKN2A/p16 INK4a inactivation and frequency of loss of heterozygosity at the p53 locus (OR 0.09, 95% CI 0.01-0.98; Fisher exact test, P-value approximately 0.03). Screening of nine exons of the p53R2 [Human Genome Organisation (HUGO) official name RRM2B] gene resulted in identification of a novel polymorphism in the 5' untranslated region, which was detected in four cases. Our results suggest that the CDKN2A (p16(INK4a) and p14(ARF) ) and p53 genes involved in the two cell cycle pathways are major and independent targets of inactivation in OSCC.

Demonstration of Scolex within Calcified Cysticercus Cyst: Its Possible Role in the Pathogenesis of Perilesional Edema

Abstract: Summary: Purpose: This study was performed to understand the relation between the scolex as demonstrated on gradient echo (GRE) imaging in a calcified cysticercus cyst and the development of perilesional edema that may be of value in understanding the pathogenesis of this entity. Methods: Twenty-one patients with solitary calcified lesion on computed tomography (CT), with seizures of recent onset (within 15 days), were selected for this study. All the patients were subjected to magnetic resonance imaging (MRI) including GRE imaging. The patients were grouped on the basis of presence or absence of perilesional edema around the calcified lesion on MRI. Results: There were 14 patients with perilesional edema, and seven patients had no evidence of edema. Of these 14 patients with perilesional edema, rim enhancement was detected in 13 patients on postcontrast MRI, whereas no enhancement was observed in one patient. The scolex was seen in all these 14 patients on GRE images. Of the seven patients without evidence of edema, the scolex was not seen in any of these patients on GRE imaging. In addition, there was no evidence of any contrast enhancement on postcontrast study in any of the patients in this group. Conclusions: We conclude that the calcified cysts with scolex seen on GRE imaging are associated with perilesional edema. This is probably due to preservation of antigenic material in these calcified cysts, the release of which provokes an inflammatory response that may be responsible for the perilesional edema.

Functionalized Polylactides: Preparation and Characterization of [l]-Lactide-co-Pentofuranose

Abstract: The new monomer 1,2-O-isopropylidene-3-benzyloxy-pentofuranose-4,4‘-cyclic carbonate (IPPTC) was prepared. IPPTC has both a ketal-protected diol and a benzyl ether-protected hydroxyl. Thus, these two sets of hydroxyl groups can be independently deprotected to give IPPTC repeat units with one, two, or three free hydroxyl groups. Stannous octanoate at 130 °C was used for the copolymerization of [l]-LA with IPPTC. When fLA/fIPPTC was 91/9, the percent yield, Mn, and percent incorporation of IPPTC units were 78%, 77 800 g/mol, and 4 mol %, respectively. By the method of Fineman and Ross, the [l]-LA and IPPTC comonomer reactivity ratios were 8.6 and 0.51, respectively. Relative to poly([l]-LA), incorporation of IPPTC units into [l]-LA/IPPTC copolymers gave products that are lower melting (112 °C, 14 mol % IPPTC) and have higher thermal stabilities and higher glass transition temperatures (69 °C, 100 mol % IPPTC). The liberation of hydroxyl pendant groups by the selective removal of the benzyl ether, the ketal ...

A community-based rheumatic fever/rheumatic heart disease cohort: twelve-year experience.

Abstract: Background: A pilot rheumatic fever and rheumatic heart disease control porject was started in 1988 in blocks of district Ambala (Haryana) to test the feasibility of early detection, treatment and secondary prophylaxis for rheumatic fever/rheumatic heart disease cases. School teachers, students and health workers were trained to identify and refer suspected cases of rheumatic fever/rheumatic heart disease to the community health center where physicians examined the suspected cases and monthly secondary prophylaxis was provided to the confirmed cases. Methods and Results: A survey of registered cases was done in 1999 to determine the compliance rate of secondary prophylaxis and to describe clinical and epidemiologic features of the registered cohort of rheumatic fever/rheumatic heart disease patients. A total of 257 patients had been registered till the end of 1999 with 1263 person-years of follow-up. Out of these registered patients, 132 were receiving secondary prophylaxis, 52 had died, 17 had migrated, 8 were lost to follow-up, 18 had stopped prophylaxis and 30 completed the prophylaxis course. The mean age at registration was 18 years. Half of the cases were in the 6-15 years age group at registration. Over half of the patients were registered with a history of rheumatic fever. Fever was the most common symptom (75.9%). Carditis was more common among cases with recurrent attacks of rheumatic fever than after a first attack. The mortality in rheumatic fever/rheumatic heart cases was 32.5/1000 person-years. The mean age at death was 24.4 years. Compliance with secondary prophylaxis was 92% during the past 12 years. Conclusions: A rheumatic fever/rheumatic heart disease control program can be sustained within the primary health care system and the case registry can be utilized not only for monitoring the program but also to gain insight into the epidemiology of the disease.

Effect of vitamin a supplementation on childhood morbidity and mortality

Abstract: In a double blind design, 1520 children aged 12, 6-12 and < 6 months of age received 200,000, 100,000, 500,000 I.U. of vitamin A respectively every 4 to 6 months during 15 months trial period. The prevalence of vitamin A deficiency was significantly reduced in vitamin A compared to placebo group during the follow-up period. In vitamin A group, incidence of diarrhoea and measles was significantly reduced but incidence of acute respiratory infections was not significantly different compared to control group. Risk of death was also significantly less in vitamin A group. Therefore, promotion of vitamin A rich diet or supplementation with synthetic vitamin A at 4-6 month interval should be a priority in populations where risk of vitamin A deficiency is high.

Dynamical Behaviour of Orthotropic Micropolar Elastic Medium

Abstract: The present paper is concerned with the plane strain problem in homogeneous micropolar orthotropic elastic solids. The disturbance due to continuous normal and tangential sources are investigated b...

Time trends in the prevalence of hypertension and associated risk factors in Chandigarh.

Abstract: To estimate the changes in the prevalence of hypertension and associated risk factors over a 30 years period a cross-sectional population survey in three randomly selected sectors of Chandigarh city was carried out. Study population consisted of 1181 individuals (570 males and 611 females) aged 35 years and above. A total of 1049 subjects were interviewed using a structured interview schedule, and 937 were examined by a physician. Blood pressure and anthropometric measurements were recorded. Physical activity was graded according to the job performed by the individual. Guidelines of the Fifth Joint National Committee (JNC-V) of USA were used for diagnosis of hypertension. Estimation of body fat from skin fold thickness was done by applying Grande's formula and the method of Pascale et al. Data were compared to that of year 1968 when a similar cross-sectional survey had been carried out in Chandigarh. Age and sex standardised prevalence of hypertension according to JNC-V criteria increased from 26.9 per cent in 1968 to 44.9 per cent in 1996-97. In 1968, 70% of the male population were engaged in sedentary and light physical activity compared to 73.7 per cent in 1996-97. Total body fat has increased in both men and women. High and high middle income groups in males were 61.2% in 1996-97 compared to 37.4% in 1968. Smoking rates, however, remained unchanged, 25.4 per cent men smoked in 1968 compared to 24.6 per cent in 1996-97. The prevalence of hypertension has almost doubled over 30 years in Chandigarh. Unfavourable change in prevalence of hypertension, physical activity and body fat makes this population highly vulnerable to cardiovascular morbidity and mortality.

Biocatalytic route to well-defined macromers built around a sugar core.

Abstract: By using 4-C-hydroxymethyl-α-d-pentofuranose as the sugar core and lipase-catalyzed transformations, a macromer was constructed with exceptional control of substituent placement around the carbohydrate core. The key synthetic transformations performed were as follows: (1) selective lipase-catalyzed acrylation along with prochiral selection of 4-C-hydroxymethyl-1,2-O-isopropylidene-α-d-pentofuranose (diastereomeric excess up to 93%); (2) the ring-opening of e-caprolactone, e-CL, from the remaining primary hydroxyl group to give an acryl-sugar capped macromer (Mn = 11 300, Mw/Mn = 1.36, initiator efficiency 50−55%, <5% water initiated PCL chains); (3) selective lipase-catalyzed esterification of the terminal hydroxyl of oligo(e-CL) chains; (4) hydrolysis of the 1,2-O-isopropylidene group at the sugar core without any substantial loss in macromer molecular weight; and (5) homopolymerization of the corresponding macromer. In principle, the method developed is flexible so that it can be used to generate a wid...

Seroepidemiological study of toxoplasmosis in different sections of population of Union Territory of Chandigarh.

Abstract: Infections with Toxoplasma gondii in humans are usually asymptomatic or in the form of mild febrile illness. Primary infection in pregnant women may result in congenital toxoplasmosis while infection in immunocompromised subjects like AIDS patients may cause potentially fatal toxoplasma encephalitis. In India, only a few studies in hospital based patients have shown prevalence of toxoplasmosis to be between 1.5 and 21%. No field study involving general population is available. The present study investigates the prevalence of toxoplasmosis in subjects from rural, urban and urban slum populations of Union Territory, Chandigarh. Serum samples from 500 subjects from each group were collected and antitoxoplasma IgM and IgG was detected by conventional micro ELISA technique using soluble Toxoplasma gondii tachyzoite antigen. Overall 5.4% subjects were positive for IgM while 4.66% showed IgG antitoxoplasma antibodies. Amongst the three groups, significantly higher number of subjects in slum area (7.8%) showed IgM antibodies as compared to urban and rural areas (4.2% each). There was no significant difference in IgG positivity between three study areas. Prevalence of T. gondii specific IgG antibodies was significantly higher amongst females of both slum (7.31%) and rural area (8.44%) as compared to the males (2.85% and 3.27% respectively) in the same areas (p or = 5 years (17.7%). These data indicate that majority of children are exposed to toxoplasma before 12 years of age and particularly in rural areas higher number of subjects acquire Toxoplasma gondii infection early in childhood probably as a result of higher exposure due to farming, poor hygiene and handling of animals.

Clinical score card for diagnosis of group A streptococcal sore throat.

Abstract: Objective: Group A β hemolytic streptococcus (GAS) sore throat primarily occurs among children in 5–15 years age group, and if not treated appropriately causes rheumatic fever/.rheumatic heart disease (RF/RHD). Present study was aimed at validation of a clinical scoring system for diagnosis of GAS.Methods: Five hundred and thirty six children in 5–15 years age group were enrolled by systematic random selection of households from a peri-urban slum of Chandigarh. They were visited fortnightly at their home for one year to record signs and symptoms of cough and cold. Throat swabs were collected in 918 episodes, of which 123 (13.4%) were GAS culture positive.Result : Significant association of GAS was found with pain in the throat, enlarged tonsils, pharyngeal erythema and tender cervical lymphadenopahty. According to the percentage positivity of GAS culture, weighted scores were assigned to age of the child, season of occurrence, fever, size of tonsil, pharyngeal erythema and exudate, lymphadenopathy and pain in throat. Combinations of various symptoms and signs gave sensitivity of 86–89% and specificity of 83–89% whereas clinical score of 15 or more had 91% sensitivity and 98% specificity for diagnosis of GAS pharyngitis.Conclusion: As the level of clinical acumen and prevalence of GAS may differ in different primary care settings of the country, the proposed scoring system should be validated and adapted to suit local conditions before establishing it in the primary prophylaxis strategy to prevention of RF/RHD.

Role of travel as a risk factor for hepatitis E virus infection in a disease-endemic area.

Abstract: BACKGROUND We undertook epidemiologic and laboratory studies during an epidemic of acute hepatitis in Sindri town, in District Dhanbad, Bihar in 1998. METHODS A sample survey covering 201 randomly selected houses in the town was conducted during the epidemic, and records of patients admitted to the only large hospital in this town were reviewed. We also tested serum and stool specimens from some of the affected persons for hepatitis E virus (HEV) RNA and IgM anti-HEV antibodies. RESULTS Of the 1088 persons residing in the surveyed houses, 82 (7.54%) had developed acute hepatitis during the outbreak. Attack rate was higher among male residents than among female residents (71/604 vs. 11/484; 11.75% vs. 2.27%; relative risk [RR] 5.17 [95% confidence interval 2.77-9.65]; p<10(-6)) and was the highest in the 10-29 year age group. Hospital admission data showed similar age and gender distribution. Disease occurrence had no relation with source of drinking water (handpump 7.56% vs. municipal tap 7.53%; p=ns), or with habit of boiling (RR 1.10 [0.61-1.98]; p=ns) or filtering (RR 0.59 [0.33-1.06]; p=ns) water before drinking. Jaundice occurred more frequently among persons who had traveled outside Sindri town during the last two months than among those who had not (26.4% vs. 4.7%; RR 5.67 [3.81-8.43]; p<10(-6)); this risk persisted after correction for age (Mantel-Haenszel weighted OR 6.74 [4.12-11.01]; p<10(-6)). Men traveled more frequently than women and were more often affected. In multivariate analysis, travel and male gender were the only two independent risk factors. Data from a hospital in a neighboring large city, Dhanbad, suggested that there was an outbreak of hepatitis in that city too at the same time. Seventy-three of the 1088 study subjects had history of jaundice in the past; disease attack rate among these persons (9.6%) was similar to that among those without such history (7.5%; RR 1.31 [0.49-2.98]; p=ns). Of the 13 sera tested, 10 were positive for IgM anti-HEV. HEV RNA was detected in 9 of the 12 stool specimens and 10 of the 13 sera tested. CONCLUSIONS The hepatitis epidemic in Sindri was caused by HEV and had several features resembling those of previous HEV epidemics. However, the occurrence of hepatitis E showed a strong relationship with history of travel, a finding not hitherto described.

Influence and Green's functions for orthotropic micropolar continua

Abstract: The article reports on a methodology to synthesize the response of orthotropic micropolar half-space subjected to concentrated and distributed loads. The disturbance due to normal and tangential loads are investigated by employing the eigenvalue approach. The integral transforms have been inverted by using a numerical technique to obtain the normal displacement, normal force stress and tangential couple stress in the physical domain. The results concerning these quantities are given and illustrated graphically.

Differentiation of hydatid cyst from cysticercus cyst by proton MR spectroscopy

Abstract: The metabolite patterns obtained by ex vivo proton MR spectroscopy of fluid from different locations of hydatid cysts of sheep and humans (n = 16) and cysticercus cysts of swine and humans (n = 25) were compared with an objective of differentiating the two parasites on the basis of their metabolite pattern. The spectra from hydatid fluid differed from cysticercus cyst by the absence of creatine in the former. When the hydatid cyst was fertile, malate and/or fumarate was also observed, which was absent in cysticercus cyst. The most likely explanation for the presence of creatine only in the cysticercus fluid is its active diffusion from the surrounding host tissue along with a contribution from the musculature present in the bladder wall of the cyst.

Evaluation of minimum inhibitory concentration of quinolones and third generation cephalosporins to Salmonella typhi isolates.

Abstract: A total of 323 Salmonella typhi isolates (261 isolates obtained during 1995-99 from Ludhiana and 62 randomly selected isolates obtained between 1980-99 from Chandigarh) were analyzed for drug resistant pattern. S. typhi isolates prior to 1986 were sensitive to all the antimicrobials tested by disc diffusion method. Most common multidrug resistance pattern noticed was ACCo T i.e. resistance to ampicillin, Chloramphenicol, cotrimoxazole and tetracycline. This study has revealed that withdrawal of chloramphenicol due to high level of resistance during 1990-94, has led to re-emergence of 43-93 percent chloramphenicol sensitive mutants during 1995-99. Two S. typhi isolates in 1995 and one in 1999 from Ludhiana depicted resistance to ciprofloxacin. Susceptibility of S. typhi isolates to third generation cephalosporins ranged between 87 to 100 per cent. There was a gradual increase with time period in mean minimum inhibitory concentration (MIC) of ciprofloxacin as it increased from 0.066 ug/ml for 1980-83 S. typhi isolates to 0.13 ug/ml for the 1996-99 isolates. Similarly, cefotaxime mean MIC for 1980-83 isolate was 0.172 ug/ml which further increased up to 0.32 ug/ml for S. typhi isolates encountered between 1996-99. In contrast, mean MIC value of 0.62 ug/ml of Ceftriaxone remained unchanged irrespective of the year of isolation of S. typhi isolates.

Phenobarbitone prophylaxis for neonatal jaundice in babies with birth weight 1000-1499 grams.

Abstract: Management of neonatal jaundice is simple but in sick, very low birth weight babies poses additional hemodynamic insult. Role of prophylactic postnatal phenobarbitone (two different dosage regimens) was evaluated prospectively on occurrence of neonatal jaundice and the need for therapy in 150 babies with birth weight 1000-1499 grams. Phenobarbitone in the dose of 10mg/kg given within 6 hours of life followed by 5mg/kg/day till day 5 of life intravenously significantly decreased the need for exchange transfusion and duration of phototherapy in babies with birth weight of 1000-1499 grams. This dosage schedule was better than dose of 5mg/kg for 5 days in significantly reducing the duration of phototherapy

Knowledge and practice pattern of non-allopathic indigenous medical practitioners regarding tuberculosis in a rural area of India.

Abstract: CONTEXTE : Le systeme de medecine indienne est tres populaire en Inde. OBJECTIF : Apprecier les connaissances et le type de pratique des praticiens medicaux indigenes (IMPs) non-allopathes en ce qui concerne la tuberculose (TB). METHODES: Nous avons interviewe 74 IMPs pratiquant dans le bloc de Naraingarh, une zone rurale de l'Etat de Haryana en Inde, grâce a un schema d'interview semi-structure. RESULTATS: Quarante des 74 IMPs (54%) voient de deux a cinq patients tuberculeux chaque mois. Quarante-six sur 74 (61%) signalent qu'ils diagnostiquent la TB sur base des seuls symptomes, alors que 38% utilisent des tests de diagnostic comme les cliches du thorax, la vitesse de sedimentation globulaire et l'examen des expectorations. Quarante pour cent des IMPs considerent que l'alcool est la cause de la TB, 36,5% impliquant le tabagisme et 17,6% l'infection. Trente-quatre pour cent seulement (25/ 74) des IMPs signalent qu'ils traitent les patients TB alors que les autres affirment qu'ils referent de tels cas aux hopitaux proches. Les medicaments antituberculeux utilises par les IMPs sont l'isoniazide, la rifampicine et la streptomycine, mais aucun d'entre eux ne connait le dosage de ces medicaments, la duree de traitement ou le regime correct. Soixante-quatre pour cent de 25 IMPs font etat de l'utilisation de medicaments ayurvedic. CONCLUSION : Une proportion considerable des patients TB consultent les IMPs pour le traitement de la TB alors que les connaissances et la pratique de ces derniers sont inadequates.