Showing papers by "Rajesh Kumar published in 2007"

Phosphatonins and the regulation of phosphate homeostasis.

Abstract: Inorganic phosphate (P(i)) is required for energy metabolism, nucleic acid synthesis, bone mineralization, and cell signaling The activity of cell-surface sodium-phosphate (Na(+)-P(i)) cotransporters mediates the uptake of P(i) from the extracellular environment Na(+)-P(i) cotransporters and organ-specific P(i) absorptive processes are regulated by peptide and sterol hormones, such as parathyroid hormone (PTH) and 1alpha,25-dihydroxyvitamin D (1alpha,25(OH)(2)D(3)), which interact in a coordinated fashion to regulate P(i) homeostasis Recently, several phosphaturic peptides such as fibroblast growth factor-23 (FGF-23), secreted frizzled related protein-4 (sFRP-4), matrix extracellular phosphoglycoprotein, and fibroblast growth factor-7 have been demonstrated to play a pathogenic role in several hypophosphatemic disorders By inhibiting Na(+)-P(i) transporters in renal epithelial cells, these proteins increase renal P(i) excretion, resulting in hypophosphatemia FGF-23 and sFRP-4 inhibit 25-hydroxyvitamin D 1alpha-hydroxylase activity, reducing 1alpha,25(OH)(2)D(3) synthesis and thus intestinal P(i) absorption This review examines the role of these factors in P(i) homeostasis in health and disease

Obesity in Indian children: time trends and relationship with hypertension.

Abstract: Background. Limited data are available from India regarding the distribution and profile of childhood obesity and hypertension. We examined the time trends in childhood obesity in a representative sample of schoolchildren from Ernakulam District, Kerala and determined the relationship of obesity with blood pressure. Methods. We used a stratified random cluster sampling method to select the children. Anthropometric data were collected from 24 842 students, 5–16 years of age, during 2003–04. Blood pressure and anthropometric data were collected from 20 263 students during 2005–06. Overweight and obesity were defined by body mass index for gender and age. Gender, age and height were considered for determining hypertension. Results. The proportion of overweight children increased from 4.94% of the total students in 2003 to 6.57% in 2005 (OR: 1.36; 95% CI: 1.25–1.47; p<0.0001). The increase was significant in both boys and girls. The proportion of overweight children was significantly higher in urban regions and in private schools, and the rising trend was limited to private schools. Systolic or diastolic incident hypertension was found in 17.34% of overweight children versus 10.1% of the remaining students (OR: 1.87; 95% CI: 1.60–2.17; p<0.0001). Conclusion. Childhood obesity showed an increasing trend in a short period of 2 years. Hypertension was common in overweight children. The results suggest the need for greater public awareness and prevention programmes on childhood obesity and hypertension.

Metabolism of low-dose inorganic arsenic in a central European population: influence of sex and genetic polymorphisms.

Abstract: BACKGROUND: There is a wide variation in susceptibility to health effects of arsenic, which, in part, may be due to differences in arsenic metabolism. Arsenic is metabolized by reduction and methylation reactions, catalyzed by reductases and methyltransferases. OBJECTIVES: Our goal in this study was to elucidate the influence of various demographic and genetic factors on the metabolism of arsenic. METHODS: We studied 415 individuals from Hungary, Romania, and Slovakia by measuring arsenic metabolites in urine using liquid chromatography with hydride generation and inductively coupled plasma mass spectrometry (HPLC-HG-ICPMS). We performed genotyping of arsenic (+III) methyltransferase (AS3MT), glutathione S-transferase omega 1 (GSTO1), and methylene-tetrahydrofolate reductase (MTHFR). RESULTS: The results show that the M287T (T-->C) polymorphism in the AS3MT gene, the A222V (C-->T) polymorphism in the MTHFR gene, body mass index, and sex are major factors that influence arsenic metabolism in this population, with a median of 8.0 microg/L arsenic in urine. Females C) polymorphism in the AS3MT gene on the methylation capacity was much more pronounced in men than in women. CONCLUSIONS: The factors investigated explained almost 20% of the variation seen in the metabolism of arsenic among men and only around 4% of the variation among women. The rest of the variation is probably explained by other methyltransferases backing up the methylation of arsenic.

Evidence for a signaling axis by which intestinal phosphate rapidly modulates renal phosphate reabsorption

Abstract: The mechanisms by which phosphorus homeostasis is preserved in mammals are not completely understood. We demonstrate the presence of a mechanism by which the intestine detects the presence of increased dietary phosphate and rapidly increases renal phosphate excretion. The mechanism is of physiological relevance because it maintains plasma phosphate concentrations in the normal range after ingestion of a phosphate-containing meal. When inorganic phosphate is infused into the duodenum, there is a rapid increase in the renal fractional excretion of phosphate (FE Pi). The phosphaturic effect of intestinal phosphate is specific for phosphate because administration of sodium chloride does not elicit a similar response. Phosphaturia after intestinal phosphate administration occurs in thyro-parathyroidectomized rats, demonstrating that parathyroid hormone is not essential for this effect. The increase in renal FE Pi in response to the intestinal administration of phosphate occurs without changes in plasma concentrations of phosphate (filtered load), parathyroid hormone, FGF-23, or secreted frizzled related protein-4. Denervation of the kidney does not attenuate phosphaturia elicited after intestinal phosphate administration. Phosphaturia is not elicited when phosphate is instilled in other parts of the gastrointestinal tract such as the stomach. Infusion of homogenates of the duodenal mucosa increases FE Pi, which demonstrates the presence of one or more substances within the intestinal mucosa that directly modulate renal phosphate reabsorption. Our experiments demonstrate the presence of a previously unrecognized phosphate gut-renal axis that rapidly modulates renal phosphate excretion after the intestinal administration of phosphate.

B-RAF and N-RAS mutations are preserved during short time in vitro propagation and differentially impact prognosis.

Abstract: In melanoma, the RAS/RAF/MEK/ERK signalling pathway is an area of great interest, because it regulates tumor cell proliferation and survival. A varying mutation rate has been reported for B-RAF and N-RAS, which has been largely attributed to the differential source of tumor DNA analyzed, e.g., fixed tumor tissues or in vitro propagated melanoma cells. Notably, this variation also interfered with interpreting the impact of these mutations on the clinical course of the disease. Consequently, we investigated the mutational profile of B-RAF and N-RAS in biopsies and corresponding cell lines from metastatic tumor lesions of 109 melanoma patients (AJCC stage III/IV), and its respective impact on survival. 97 tissue biopsies and 105 biopsy-derived cell lines were screened for B-RAF and N-RAS mutations by PCR single strand conformation polymorphism and DNA sequencing. Mutations were correlated with patient survival data obtained within a median follow-up time of 31 months. B-RAF mutations were detected in 55% tissues and 51% cell lines, N-RAS mutations in 23% tissues and 25% cell lines, respectively. There was strong concordance between the mutational status of tissues and corresponding cell lines, showing a differing status for B-RAF in only 5% and N-RAS in only 6%, respectively. Patients with tumors carrying mutated B-RAF showed an impaired median survival (8.0 versus 11.8 months, p = 0.055, tissues; 7.1 versus 9.3 months, p = 0.068, cell lines), whereas patients with N-RAS-mutated tumors presented with a favorable prognosis (median survival 12.5 versus 7.9 months, p = 0.084, tissues; 15.4 versus 6.8 months, p = 0.0008, cell lines), each in comparison with wildtype gene status. Multivariate analysis qualified N-RAS (p = 0.006) but not B-RAF mutation status as an independent prognostic factor of overall survival. Our findings demonstrate that B-RAF and N-RAS mutations are well preserved during short term in vitro propagation and, most importantly, differentially impact the outcome of melanoma patients.

Cutaneous leishmaniasis caused by Leishmania tropica in Bikaner, India: parasite identification and characterization using molecular and immunologic tools.

Abstract: Identification of new foci of cutaneous leishmaniasis (CL), along with reports of Leishmania donovani causing the disease, is an issue of concern. Clinico-epidemiologic analysis of 98 cases in the endemic regions of Rajasthan state, India, suggested the preponderance of infection in men (62.24%) compared with women (37.75%). Species characterization by internal transcribed spacer 1 (ITS1) polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP), kDNA-PCR, and immunofluorescence assay established L. tropica as the causative organism. When applied directly to 32 clinical samples, kDNA PCR had a sensitivity of 96.6%, whereas ITS1 PCR had a sensitivity of 82.75%, thus facilitating diagnosis and species identification. Either parasite culture or direct microscopy alone detected 48.2% and 65.5% of the positive samples, respectively, whereas culture and microscopy together improved overall sensitivity to 89.3% (25/28). Except for the kDNA PCR, all other assays were 100% specific. This study provides the first comprehensive molecular and immunologic studies of CL in India.

Observation of Isomeric Decays in the r-Process Waiting-Point Nucleus 130 Cd 82

Abstract: The gamma decay of excited states in the waiting-point nucleus Cd-130(82) has been observed for the first time. An 8(+) two-quasiparticle isomer has been populated both in the fragmentation of a Xe-136 beam as well as in projectile fission of U-238, making Cd-130 the most neutron-rich N=82 isotone for which information about excited states is available. The results, interpreted using state-of-the-art nuclear shell-model calculations, show no evidence of an N=82 shell quenching at Z=48. They allow us to follow nuclear isomerism throughout a full major neutron shell from Cd-98(50) to Cd-130(82) and reveal, in comparison with Ni-76(48) one major proton shell below, an apparently abnormal scaling of nuclear two-body interactions.

Folate metabolic gene polymorphisms and childhood acute lymphoblastic leukemia: a case–control study

Abstract: We genotyped six folate metabolic pathway genes for 11 polymorphisms in 460 cases of childhood acute lymphoblastic leukemia (ALL) and 552 ethnically matched controls. None of the polymorphisms except the 66A>G (I22M) in the 5-methyltetrahydrofolate-homocysteine methyltransferase reductase (MTRR) gene showed any effect on disease risk. The carriers of the G-allele were associated with a marginal decreased risk of ALL (gender-adjusted global P=0.03; multiple-testing corrected P=0.25). Analysis of four polymorphisms in the MTRR gene showed statistically significant differences in haplotype distribution between cases and controls (global P G and the 524C>T polymorphisms in the MTRR gene (global P=0.03). Our results suggest that, besides a weak association of childhood ALL with the 66A>G polymorphism, haplotypes within the MTRR gene may, in part, account for population-based differences in risk.

Evaluation of some essential oils as botanical fungitoxicants for the protection of stored food commodities from fungal infestation

Abstract: Essential oils from different parts of 18 plants belonging to 11 families were extracted and tested against two toxigenic strains of Aspergillus flavus Link through the poisoned food technique. The oil of Mentha arvensis was found to be effective against both strains of A. flavus and completely stopped the radial mycelial growth of A. flavus at 0.10 mg mL−1. It was found to be superior over the synthetic fungicides tested and showed a broad fungitoxic spectrum against A. niger, A. fumigatus, Botryodiplodia theobromae, Cladosporium cladosporioides, Fusarium oxysporum, Helminthosporium oryzae, Macrophomina phaseolina and Sclerotium rolfsii at 0.10 mg mL−1. The oil completely inhibited the aflatoxin B1 production by the toxigenic strain of A. flavus at 0.05 mg mL−1. Moreover, the Mentha oil also exhibited potent antioxidant activity in 2,2′-azino-bis-3-ethylbenzothiazoline-6-sulphuric acid (ABTS) bioassay. Keeping in mind the side effects of synthetic pesticides and the global interest in botanical pesticides for plant protection due to their biodegradable nature, M. arvensis oil may be used as a botanical fungitoxicant against fungal attack to stored food commodities. The antiaflatoxigenic and antioxidant nature of the oil suggest the possibility of its exploitation for enhancing the shelf life of stored food commodities. Copyright © 2007 Society of Chemical Industry

Single feature polymorphism discovery in rice.

Abstract: The discovery of nucleotide diversity captured as single feature polymorphism (SFP) by using the expression array is a high-throughput and effective method in detecting genome-wide polymorphism. The efficacy of such method was tested in rice, and the results presented in the paper indicate high sensitivity in predicting SFP. The sensitivity of polymorphism detection was further demonstrated by the fact that no biasness was observed in detecting SFP with either single or multiple nucleotide polymorphisms. The high density SFP data that can be generated quite effectively by the current method has promise for high resolution genetic mapping studies, as physical location of features are well-defined on rice genome.

Development of liposomal systems of finasteride for topical applications: design, characterization, and in vitro evaluation.

Abstract: Finasteride (FNS) is a "drug of choice" for benign prostate hypertrophy and prostate cancer. The drug has also been reported to be useful orally in the treatment of some difficult-to-treat androgen-dependent skin disorders, such as seborrhea, acne, hirsutism, and androgenetic alopecia. However, the ideal route for its administration (i.e., topical) remains unexplored. This has logically suggested the search for strategic formulation approaches to make the drug effective on topical applications, hitherto unexplored. The present study targets the encasement of drug molecules in the interiors of vesicular compartments (liposomes) made up of hydrogenated phospholipids, as an attempt toward the development of a trans-epidermal therapeutic system of FNS. Multilamellar drug-loaded liposomes were prepared by thin-film hydration with sonication method and optimized with respect to drug payload, entrapment efficiency, and size by formulating different vesicular compositions under different process conditions. The vesicular systems consisting of saturated phospholipid (100 mg), cholesterol (50 mg), and FNS (5 mg) showed highest drug payload (2.9 mg/100 mg of total lipids), and drug entrapment efficiency (88.6%). Mean (+/-SD) vesicle size of the prepared liposomes was found to be 3.66+/-1.6 microm. Significantly higher skin permeation of FNS through excised abdominal mice skin of FNS was achieved from the liposomal formulations vis-a-vis corresponding solution and conventional gels. Liposomal FNS formulations also showed more than fivefold higher deposition of drug in skin than the corresponding plain drug solution and conventional gel. Stability studies indicated that the liposomal formulations were quite stable in the refrigerated conditions for 2 months with negligible drug leakage or vesicle size alteration during the storage period. Results of the current studies with FNS-loaded vesicular systems project the high plausibility of a topical liposomal formulation for effective localized delivery of Finasteride.

MC1R variants associated susceptibility to basal cell carcinoma of skin: interaction with host factors and XRCC3 polymorphism.

Abstract: The variants within the human melanocortin 1 receptor (MC1R) gene are associated with an increased risk of different skin cancers. In this study, we genotyped by direct sequencing, 529 cases of basal cell carcinoma of the skin (BCC) and 533 healthy controls for polymorphisms in the entire MC1R gene. In addition to 10 common polymorphisms, we detected 23 rare variants in the gene. The presence of any nonsynonymous MC1R variant was associated with an increased risk in the carriers (odds ratio OR 1.66, 95% confidence interval CI 1.28-2.14) corresponding to a population attributable fraction of about 27%. The odds ratio for the risk in the carriers of 2 MC1R variants was 2.69 (95% CI 1.77-4.08). The risk of BCC in the carriers of MC1R variants with fair complexion was almost twice as much as in the corresponding noncarriers. The carriers of the R163Q variant with a medium skin complexion were at a 3-fold higher risk than the noncarrier counterparts. The interaction, of effect on the BCC risk, between the MC1R variants and types of skin response to sun exposure was greater than multiplicative. We also observed a multiplicative interaction of risk due to the MC1R variants and the common allele (high risk) of the T241M polymorphism in the XRCC3 gene. Our data confirmed the status of the nonsynonymous MC1R variants as independent genetic risk factors for BCC. However, the mechanism through which the variants influence the risk likely involves complex interactions with other genetic and host risk factors.

Utility of the WHO Ten Questions Screen for Disability Detection in a Rural Community—the North Indian Experience

Abstract: The utility of the WHO Ten Questions Screen (TQS) was studied in a rural community of North India. The study was done in three villages, in two phases. In phase 1, the TQS was administered to parents of children aged between 2 and 9 years, during a house-to-house survey. In phase 2, all children screened positive and a random sample of 110 screened negative were clinically evaluated in detail. The total population of the three villages was 5830 with 1763 children aged between 2 and 9 years. Seventy-six children were positive on the TQS, of these, 38 were found to have significant disability, 18 had protein energy malnutrition and 19 were found normal on clinical evaluation. All the 110 screen-negative children were normal. Significantly larger numbers of boys were positive on TQS as compared to girls [Odd Ratio (OR) 1.5]. The sensitivity of the TQS for significant disability was 100%; the positive predictive value was 50% and was higher for boys than for girls. Of the 50% children classified as false positive 23% had mild delays due to malnutrition. The estimated prevalence of disability was 16/1000. The TQS was found to be a sensitive tool for detection of significant disabilities among children 2-9 years of age. The low-positive predictive value would lead to over referrals but a large number of these children would benefit from medical attention.

Biobanks in Developing Countries: Needs and Feasibility

Abstract: Technological advances coupled with use of existing resources can be used to create biological repositories that may lead to better health in developing countries.

PET-CT enteroclysis: a new technique for evaluation of inflammatory diseases of the intestine.

Abstract: Purpose While CT/MR enteroclysis provides excellent anatomical details, it fails to provide information on metabolic activity of the inflammatory lesions of the intestine. We conceptualized a fusion of metabolic imaging techniques such as PET and an anatomical imaging modality such as CT enteroclysis to derive information both on morphological details and functional activity of lesions at the same time.

Evaluation of Eupatorium cannabinum Linn. oil in enhancement of shelf life of mango fruits from fungal rotting

Abstract: Essential oils extracted from 17 higher plants belonging to different families were screened against Botryodiplodia theobromae and Colletotrichum gloeosporioides causing stem end rot disease and anthracnose disease in mango respectively. The essential oil of Eupatorium cannabinum was found to be fungitoxic in nature against both the mango-rotting fungi. Eupatorium oil was standardized through physico-chemical and fungitoxic properties. Gas Liquid Chromatography (GLC) analysis of the oil led to the identification of 16 components, which represented 77.97% of the oil. Germacrene D (16.11%) was found to be the major component. The oil showed a broad fungitoxic spectrum and was recorded to be more efficient than some synthetic fungicides. The oil also showed an inhibitory effect on pectinase and cellulase enzymes. The oil enhanced the shelf life of mango fruits by protecting from fungal rotting when tested as a fumigant. The LD50 of Eupatorium oil was found to be 22.01 ml/kg body weight on mammalian mice.

User profile aggregation

Abstract: User profile data that may be spread across different service providers and that may vary across different service providers can be aggregated to provide an aggregate user profile. An aggregate user profile can be generated regardless of, among other things, varying user profile semantics, differing data formats, data item conflicts, evolving server protocols and interfaces, and updates to the number, identity, location, and type of servers upon which the service providers are maintained.

Aberrant Central Nervous System Responses to the Valsalva Maneuver in Heart Failure

Abstract: Heart failure (HF) is associated with aberrant autonomic nervous system (ANS) activity, with altered responses to blood pressure and breathing challenges that appear to reflect abnormal central nervous system function. The authors used functional magnetic resonance imaging (fMRI) to determine whether the Valsalva maneuver, an ANS challenge, would show abnormal responses in ANS regulatory areas of the brain in HF. Brain fMRI signal changes in 5 HF patients (left ventricular ejection fraction, 0.15±0.08; age, 50±10 years) and 14 controls (age, 47±11 years) were assessed during 3 successive Valsalva maneuvers. The hypothalamus, hippocampus, putamen, amygdala, mid-cingulate, right insula, and cerebellar cortex showed exaggerated and phase-shifted fMRI responses in HF; other areas showed inverted signals from those found in controls. Central ANS control areas have altered phase, extent, and direction of responses to Valsalva maneuvers in a small sample of HF patients. These findings suggest that therapeutics that address neuroprotective aspects may be useful interventions for the condition.

Polymorphisms in XPD, XPC and the risk of death in patients with urinary bladder neoplasms.

Abstract: We conducted a follow-up study on 311 patients with urinary bladder neoplasms to investigate the association of polymorphisms in DNA repair and cell growth regulatory genes with the clinical outcomes of this disease. We found that patients carrying the variant allele of XPD (K751Q) polymorphism were at lower risk of death (p � /0.04) than the noncarriers. Patients that were simultaneous carriers of variant alleles from XPD (K751Q) and XPC (K939Q) polymorphisms, showed lower risk of death than the other patients (p� /0.001). The variant allele carriers of MSH6 (G39E) polymorphism showed a higher risk for highly malignant disease (TaG3� /T1) than the non-carriers (p� /0.03). The variant allele carriers of XRCC1 (R399Q) polymorphism showed lower risk for recurrence (TaG2; p � /0.05) and death (T2� / ;p � /0.03) after instillation and radiotherapy than the non-carriers. After radiotherapy, an inverse association of the variant allele of OGG1 (S326C) polymorphism was observed with the risk of death (T2� / ;p � /0.04). A significant low-risk for stage progression (p� /0.03) was observed in patients carrying the variant allele of H-ras (H27H) polymorphism. Our results are consistent with the notion that the XPD (K751Q) polymorphism either individually or in combination with the XPC (K939Q) polymorphism modulates the risk of death in patients with urinary bladder neoplasms. DNA damage and subsequent repair are closely associated with carcinogenesis. The repair processes continuously remove DNA damage caused by exogenous and endogenous agents and are essential for maintenance of genomic integrity. Damage left unrepaired can lead to misincorporation of bases, which in turn may result in fixation of mutations. The mutations in critical genes give cells an advantage for clonal expansion and can lead to initiation of carcinogenesis [1]. Four elaborate repair pathways remove specific types of damaged DNA. Base excision repair (BER) is involved in removal of small lesions. Nucleotide excision repair (NER) is involved in removal of bulky lesions like UV photoproducts and other large adducts such as those formed by polycyclic aromatic hydrocarbons. DNA double strand breaks, produced by replication errors or by exogenous agents, are repaired by homologous recombination (HRR) or non-homologous end

Role-based user tracking in service usage

Abstract: Devising a centralized usage database for tracking and recording the usage of various services by various users may be difficult for several reasons, including the volume of data generated by each user in interacting with each service. Techniques are disclosed for streamlining usage data transmitted between the services, the users, and the usage database, such as by redistributing a portion of the computational burden to the users, and by characterizing the usage data based on the role of each user in interacting with each service. Additional techniques are disclosed for caching and authenticating the usage data, and for improving the response rate in the interaction of the usage database with users in order to provide a better user experience.

No association between MDM2 SNP309 promoter polymorphism and basal cell carcinoma of the skin.

Abstract: Summary Background The MDM2 oncoprotein promotes cell survival and cell cycle progression by inhibiting the p53 tumour suppressor protein. Further, overexpression of the MDM2 gene can inhibit DNA double-strand break repair in a p53-independent manner. Recent studies have shown that a single nucleotide polymorphism (SNP) in the intronic promoter region of MDM2 (called SNP309) can significantly change the expression of MDM2 and thereby suppress the p53 pathway. This SNP was also found to be associated with the onset and risk of different cancer types. Basal cell carcinoma of the skin (BCC) is one of the most common neoplasms in the world. BCC development is associated with environmental factors (especially sun exposure) as well as heritable factors. Objectives The present case–control study investigated the association of the MDM2 SNP309 with the risk and the age at onset of BCC. Methods Data from 509 individuals affected by BCC and 513 healthy controls were genotyped with TaqMan polymerase chain reaction. Results Cases and controls showed a similar genotype distribution and the SNP did not modify the age at onset of BCC. Conclusions These results suggest that the MDM2 SNP309 alone affects neither the risk nor the age at onset of BCC.

Higher frequency of Yq microdeletions in sperm DNA as compared to DNA isolated from blood.

Abstract: Aim: To determine if Yq microdeletion frequency and loci of deletion are similar in two tissues (blood and sperm) of different embryological origin. Methods: The present study included 52 infertile oligozoospermic cases. In each case, DNA was isolated from blood and sperms and polymerase chain reaction (PCR) microdeletion analysis was done from genomic DNA isolated from both the tissues. The PCR products were analyzed on a 1.8% agarose gel. PCR amplifications found to be negative were repeated at least three times to confirm the deletion of a given marker. Results: Only 1 case harbored microdeletion in blood DNA, whereas 4 cases harbored microdeletion in sperm DNA. Conclusion: The frequency of Yq microdeletions is higher in germ cells as compared to blood. As the majority of infertile couples opt for assisted reproduction procreation techniques (ART), Yq microdeletion screening from germ cells is important to understand the genetic basis of infertility, to provide comprehensive counseling and most adapted therapeutics to the infertile couple.

Psychosocial predictors of adolescent sexual behavior

Abstract: Objective To find out the psychosocial factors associated with adolescent sexual behavior.

Surface wave propagation in a fluid-saturated incompressible porous medium

Abstract: A study of surface wave propagation in a fluid-saturated incompressible porous half-space lying under a uniform layer of liquid is presented. The dispersion relation connecting the phase velocity with wave number is derived. The variation of phase velocity and attenuation coefficients with wave number is presented graphically and discussed. As a particular case, the propagation of Rayleigh type surface waves at the free surface of an incompressible porous half-space is also deduced and discussed.

Polymorphisms in NQO1 and the clinical course of urinary bladder neoplasms.

Abstract: Objective. Urinary bladder neoplasms differ considerably in biological potential, and tumor morphology alone cannot predict their clinical behaviors. Polymorphisms in xenobiotic metabolic genes ...