547 research outputs found

    On the role of twisted statistics in the noncommutative degenerate electron gas

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    We consider the problem of a degenerate electron gas in the background of a uniformly distributed positive charge, ensuring overall neutrality of the system, in the presence of non-commutativity. In contrast to previous calculations that did not include twisted statistics, we find corrections to the ground state energy already at first order in perturbation theory when the twisted statistics is taken into account. These corrections arise since the interaction energy is sensitive to two particle correlations, which are modified for twisted anti-commutation relations

    Regulation of sonic hedgehog-GLI1 downstream target genes PTCH1, Cyclin D2, Plakoglobin, PAX6 and NKX2.2 and their epigenetic status in medulloblastoma and astrocytoma

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    Abstract Background The Sonic hedgehog (Shh) signaling pathway is critical for cell growth and differentiation. Impairment of this pathway can result in both birth defects and cancer. Despite its importance in cancer development, the Shh pathway has not been thoroughly investigated in tumorigenesis of brain tumors. In this study, we sought to understand the regulatory roles of GLI1, the immediate downstream activator of the Shh signaling pathway on its downstream target genes PTCH1, Cyclin D2, Plakoglobin, NKX2.2 and PAX6 in medulloblastoma and astrocytic tumors. Methods We silenced GLI1 expression in medulloblastoma and astrocytic cell lines by transfection of siRNA against GLI1. Subsequently, we performed RT-PCR and quantitative real time RT-PCR (qRT-PCR) to assay the expression of downstream target genes PTCH1, Cyclin D2, Plakoglobin, NKX2.2 and PAX6. We also attempted to correlate the pattern of expression of GLI1 and its regulated genes in 14 cell lines and 41 primary medulloblastoma and astrocytoma tumor samples. We also assessed the methylation status of the Cyclin D2 and PTCH1 promoters in these 14 cell lines and 58 primary tumor samples. Results Silencing expression of GLI1 resulted up-regulation of all target genes in the medulloblastoma cell line, while only PTCH1 was up-regulated in astrocytoma. We also observed methylation of the cyclin D2 promoter in a significant number of astrocytoma cell lines (63%) and primary astrocytoma tumor samples (32%), but not at all in any medulloblastoma samples. PTCH1 promoter methylation was less frequently observed than Cyclin D2 promoter methylation in astrocytomas, and not at all in medulloblastomas. Conclusions Our results demonstrate different regulatory mechanisms of Shh-GLI1 signaling. These differences vary according to the downstream target gene affected, the origin of the tissue, as well as epigenetic regulation of some of these genes.http://deepblue.lib.umich.edu/bitstream/2027.42/78313/1/1471-2407-10-614.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78313/2/1471-2407-10-614.pdfPeer Reviewe

    Waist Circumference and BMI in Relation to Serum High Sensitivity C-Reactive Protein (hs-CRP) in Cuban Americans With and Without Type 2 Diabetes

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    Relationship between high-sensitivity C-reactive protein (hs-CRP) and adiposity by diabetes status and gender in Cuban-Americans with and without type 2 diabetes (T2D) was studied. Adult subjects, 226 females, 129 males participated in a case control, single time point study. Subjects with T2D were older, had higher waist circumference (WC) and body mass index (BMI). WC and BMI were associated with ln hs-CRP (P < 0.001). An interaction with diabetes status was found for BMI (P = 0.037). Gender showed a strong relationship with ln hs-CRP (P < 0.001), which was moderated by diabetes status. Only males without diabetes exhibited a significant relationship for both WC and BMI with ln hs-CRP. In this sample of Cuban-Americans, WC and BMI had stronger associations with ln hs-CRP but not with diabetes status. Obesity prevention and controlling for CRP levels may be necessary to eliminate its contributions to develop diabetes and cardiovascular disease (CVD)

    Non-specific abdominal pain and air pollution: a novel association.

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    We studied whether short-term exposure to air pollution was associated with non-specific abdominal pain in epidemiologic and animal studies. Patients visiting the emergency department with non-specific abdominal pain were identified in Edmonton (1992 to 2002, n = 95,173) and Montreal (1997 to 2002, n = 25,852). We calculated the daily concentrations for ozone (O(3)), nitrogen dioxide (NO(2)), sulfur dioxide (SO(2)), carbon monoxide (CO), and particles <10 (PM(10)) or <2.5 (PM(2.5)) µm. A case crossover study design was used to estimate the odds ratio (OR) and 95% confidence interval (CI) associated with an increase in the interquartile range of the air pollutants. We investigated differential effects by age and sex. Mice were gavaged with urban particle extracts. In animal models, colonic motility was tested, and visceral abdominal pain was measured using a writhing test, and behavioral response to oil of mustard and neostigmine. Motility and pain was measured acutely (1.5 hours after gavage) and chronically (7-days and 21-days after gavage). Emergency department visits for non-specific abdominal pain were primarily by women between the ages of 15-24 years. Individuals aged 15 to 24 years were at increased risk of non-specific abdominal pain in Edmonton (same day CO: OR = 1.04, 95% CI = 1.02-1.06; and NO(2): OR = 1.06, 95% CI = 1.03-1.09). The risk of air pollution among 15-24 year olds in Montreal was significantly positive (same day CO: OR = 1.11, 95% CI = 1.05-1.17; NO(2): OR = 1.09, 95% CI = 1.01-1.16; SO(2): OR = 1.17, 95% CI = 1.10-1.25; PM(2.5): OR = 1.09, 95% CI = 1.04-1.15). Abdominal pain was increased by an acute gavage of pollution extract but not to chronic exposure to pollutants. Colonic transit was delayed following chronic but not acute exposure with the pollutants. Epidemiological and animal data suggest that short-term exposure to air pollution may trigger non-specific abdominal pain in young individuals

    Hypertension, poor glycemic control, and microalbuminuria in Cuban Americans with type 2 diabetes

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    Gustavo G Zarini1, Joel C Exebio1, Deva Gundupalli1, Subrata Nath2, Fatma G Huffman11Florida International University, Robert R Stempel School of Public Health, Department of Dietetics and Nutrition, Miami, Florida, USA; 2Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USAPurpose: To investigate to what degree the presence of hypertension (HTN) and poor glycemic control (GC) influences the likelihood of having microalbuminuria (MAU) among Cuban Americans with type 2 diabetes (T2D).Methods: A cross-sectional study conducted in Cuban Americans (n = 179) with T2D. Participants were recruited from a randomly generated mailing list purchased from KnowledgeBase Marketing, Inc. Blood pressure (BP) was measured twice and averaged using an adult size cuff. Glycosylated hemoglobin (A1c) levels were measured from whole blood samples with the Roche Tina-quant method. First morning urine samples were collected from each participant to determine MAU by a semiquantitative assay (ImmunoDip).Results: MAU was present in 26% of Cuban Americans with T2D. A significantly higher percentage of subjects with MA had HTN (P = 0.038) and elevated A1C (P = 0.002) than those with normoalbuminuria. Logistic regression analysis showed that after controlling for covariates, subjects with poor GC were 6.76 times more likely to have MAU if they had hypertension compared with those without hypertension (P = 0.004; 95% confidence interval [CI]: 1.83, 23.05). Conclusion: The clinical significance of these findings emphasizes the early detection of MAU in this Hispanic subgroup combined with BP and good GC, which are fundamentals in preventing and treating diabetes complications and improving individuals&amp;rsquo; renal and cardiovascular outcomes.Keywords: blood pressure, A1c, kidney function, cardiovascular disease, Hispanic

    Isotope thermometery in nuclear multifragmentation

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    A systematic study of the effect of fragment−-fragment interaction, quantum statistics, γ\gamma-feeding and collective flow is made in the extraction of the nuclear temperature from the double ratio of the isotopic yields in the statistical model of one-step (Prompt) multifragmentation. Temperature is also extracted from the isotope yield ratios generated in the sequential binary-decay model. Comparison of the thermodynamic temperature with the extracted temperatures for different isotope ratios show some anomaly in both models which is discussed in the context of experimentally measured caloric curves.Comment: uuencoded gzipped file containing 20 pages of text in REVTEX format and 12 figures (Postscript files). Physical Review C (in press

    Rapid cooling of magnetized neutron stars

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    The neutrino emissivities resulting from direct URCA processes in neutron stars are calculated in a relativistic Dirac-Hartree approach in presence of a magnetic field. In a quark or a hyperon matter environment, the emissivity due to nucleon direct URCA processes is suppressed relative to that from pure nuclear matter. In all the cases studied, the magnetic field enhances emissivity compared to the field-free cases.Comment: 9 pages; Revtex; figure include
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