45 research outputs found

    Variation in optineurin (OPTN) allele frequencies between and within populations

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    PURPOSE: To evaluate the extent to which mutations in the optineurin (OPTN) glaucoma gene play a role in glaucoma in different populations. METHODS: Case-controlled study of OPTN sequence variants in individuals with or without glaucoma in populations of different ancestral origins and evaluate previous OPTN reports. We analyzed 314 subjects with African, Asian, Caucasian and Hispanic ancestries included 229 cases of primary open-angle glaucoma, 51 cases of juvenile-onset open-angle glaucoma, 33 cases of normal tension glaucoma, and 371 controls. Polymerase chain reaction-amplified OPTN coding exons were resequenced and case frequencies were compared to frequencies in controls matched for ancestry. RESULTS: The E50K sequence variant was identified in one individual from Chile with normal tension glaucoma, and the 691_692insAG variant was found in one Ashkenazi Jewish individual from Russia. The R545Q variant was found in two Asian individuals with primary open-angle glaucoma; one of Filipino ancestry and one of Korean ancestry. In addition to presenting OPTN allele frequencies for Caucasian and Asian populations that have been the subject of previous reports, we also present information for populations of Hispanic and black African ancestries. CONCLUSIONS: Our study contributes additional evidence to support the previously reported association of the OPTN E50K mutation with glaucoma. After finding an additional 691_692insAG OPTN variant, we can still only conclude that this variant is rare. Combined analysis of our data with data from more than a dozen other studies indicates no association of R545Q with glaucoma in most populations. Those same studies disagree in their conclusions regarding the role of M98K in glaucoma. Our analysis of the combined data provides statistically significant evidence of association of M98K with normal tension glaucoma in Asian populations, but not in Caucasian populations; however, the validity of this conclusion is questionable because of large differences in allele frequencies between and within populations. It is currently not possible to tell how much of the underlying cause of the allele frequency difference is attributable to demographic, technical, or ascertainment differences among the studies

    Lack of association between angiotensin-converting enzyme (ACE) genotype and essential hypertension in Peruvian older people

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    Background: Epidemiological studies have shown an association between the ACE gene I/D polymorphism with arterial hypertension, specifically the DD genotype, in different populations. The objective of this study is to evaluate the association between ACE polymorphisms (Insertion, Deletion or I/D) and essential hypertension in a population of Lima, Peru. Material and methods: This is a study of cases (essential arterial hypertension) and controls, with determination of the ACE I/D genotype. Results: Cases (65) and controls (39) had a mean age (standard deviation) of 74.3 (7.9) and 72.6 (6.5) (p = 0.24). In cases, the genotype frequencies DD, ID, and II were 6 (9.2%), 28 (43.1%) and 31 (47.7%), respectively. In controls, the genotype frequencies DD, ID, and II were 6 (15.4%), 14 (35.9%) and 19 (48.7%). The Hardy-Weinberg equilibrium analysis in cases and controls was p = 0.93 and p = 0.23, respectively. No significant associations between genotype DD vs. ID + II (OR = 0.56, 95% CI: 0.17–1.87, p = 0.34) or II vs. DD + ID (OR = 0.95, 95% CI: 0.43–2.12, p = 0.92) and essential hypertension were found. Conclusions: The ACE I/D polymorphism was not associated with hypertension in our sample

    Estudio genotóxico de una bebida experimental de quinua, kiwicha y kañiwa

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    Genotoxic evaluation is an important step for a product that is aimed for human consumption. A beverage composed of pseudocereals with highly nutritious elements like quinua (Chenopodium quinoa Willd.), kiwicha (Amaranthus caudatus L.) and kañiwa (Chenopodium pallidicaule Aellen) was prepared to reduce lipid contents in a group of volunteers. The objective of the present study is to evaluate the genotoxic potential of an experimental beverage using two in vitro tests that have been validated by international agencies. For the Ames test, two strains of Salmonella typhimurium (TA98 and TA100) with and without microsomal fraction (S9) were used. Four doses of the beverage were tested and also a possible protective effect (same four doses of beverage added to plates with mutagens). Cultures of binucleated lymphocytes and five doses of the beverage were used for the micronucleus test. Both Ames and the micronucleus tests showed the beverage has not genotoxic effect in all tested doses. However, in evaluating the possible protective effect of the beverage, it would be evident that on the contrary, the mutagenic effect of mutagens used for each strain is enhanced. These results suggest that additional tests should be performed to check the genotoxic potential of this beverage before consumption.La evaluación genotóxica de un producto es un paso importante para determinar su viabilidad para consumo humano. Se ha elaborado una bebida experimental a base de pseudocereales de alto valor nutricional como son quinua (Chenopodium quinoa Willd.), kiwicha (Amaranthus caudatus L.) y kañiwa (Chenopodium pallidicaule Aellen), preparada para inducir un posible efecto hipolipemiante en un grupo de personas. El objetivo de este estudio fue evaluar el potencial genotóxico de esta bebida experimental mediante dos pruebas in vitro validadas por agencias internacionales. En la prueba de Ames se utilizaron las cepas TA98 y TA100 de Salmonella typhimurium, con y sin fracción microsomal (S9). Se evaluaron 4 dosis de bebida y además un posible efecto antimutagénico (mismas 4 dosis más mutágeno). Para la prueba de micronúcleos se usó cultivos de linfocitos con células binucleadas, en presencia de cinco dosis de la bebida. Ambas pruebas indican que la bebida estudiada en sus distintas dosis, no presenta efecto genotóxico. Sin embargo, en la evaluación del posible efecto protector de la bebida, se evidenciaría que por el contrario, se potencia el efecto mutagénico de los mutágenos empleados para cada cepa. Por lo tanto, es importante que esta bebida experimental sea sometida a pruebas adicionales in vitro e in vivo para evaluar el potencial genotóxico antes de su consumo

    Blockage of angiotensin II type I receptor decreases the synthesis of growth factors and induces apoptosis in C6 cultured cells and C6 rat glioma

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    Angiotensin II (Ang II) is a main effector peptide in the renin–angiotensin system and participates in the regulation of vascular tone. It also has a role in the expression of growth factors that induce neovascularisation which is closely associated to the growth of malignant gliomas. We have shown that the selective blockage of the AT1 receptor of angiotensin inhibites tumour growth, cell proliferation and angiogenesis of C6 rat glioma. The aim of this study was to study the effects of the blockage of AT1 receptor on the synthesis of growth factors, and in the genesis of apoptosis in cultured C6 glioma cells and in rats with C6 glioma. Administration of losartan at doses of 40 or 80 mg kg−1 to rats with C6 glioma significantly decreased tumoral volume and production of platelet-derived growth factor, vascular endothelial growth factor and basic fibroblast growth factor. It also induced apoptosis in a dose-dependent manner. Administration of Ang II increased cell proliferation of cultured C6 cells which decreased by the administration of losartan. Our results suggest that the selective blockage of AT1 diminishes tumoral growth through inhibition of growth factors and promotion of apoptosis

    Expression of AT1 and AT2 angiotensin receptors in astrocytomas is associated with poor prognosis

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    Astrocytomas develop intense vascular proliferation, essential for tumour growth and invasiveness. Angiotensin II (ANGII) was initially described as a vasoconstrictor; recent studies have shown its participation in cellular proliferation, vascularisation, and apoptosis. We conducted a prospective study to evaluate the expression of ANGII receptors – AT1 and AT2 – and their relationship with prognosis. We studied 133 tumours from patients with diagnosis of astrocytoma who underwent surgery from 1997 to 2002. AT1 and AT2 were expressed in 52 and 44% of the tumours, respectively, when determined by both reverse transcriptase–polymerase chain reaction and immunohistochemistry. Ten per cent of low-grade astrocytomas were positive for AT1, whereas grade III and IV astrocytomas were positive in 67% (P<0.001). AT2 receptors were positive in 17% of low-grade astrocytomas and in 53% of high-grade astrocytomas (P=0.01). AT1-positive tumours showed higher cellular proliferation and vascular density. Patients with AT1-positive tumours had a lower survival rate than those with AT1-negative (P<0.001). No association to survival was found for AT2 in the multivariate analysis. Expression of AT1 and AT2 is associated with high grade of malignancy, increased cellular proliferation, and angiogenesis, and is thus related to poor prognosis. These findings suggest that ANGII receptors might be potential therapeutic targets for high-grade astrocytomas

    The ALICE experiment at the CERN LHC

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    ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries. Its overall dimensions are 161626 m3 with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008

    Ultralight vector dark matter search using data from the KAGRA O3GK run

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    Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

    Lack Of Association Between Angiotensin-converting Enzyme (Ace) Genotype And Essential Hypertension In Peruvian Older People

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    Background: Epidemiological studies have shown an association between the ACE gene I / D polymorphism with arterial hypertension, specifically the DD genotype in different populations. The objective of this study is to evaluate the association between ACE polymorphisms (Insertion, Deletion or I/D) and essential hypertension in a population of Lima, Peru. Material and methods This is a study of cases (essential arterial hypertension) and controls, with determination of the ACE I/D genotype. Results Cases (65) and controls (39) had a mean age (standard deviation) of 74.3 (7.9) and 72.6 (6.5) (p = 0.24). In cases, the genotype frequencies DD, ID, and II were 6 (9.2%), 28 (43.1%) and 31 (47.7%), respectively. In controls, the genotype frequencies DD, ID, and II were 6 (15.4%), 14 (35.9%) and 19 (48.7%). The Hardy ? Weinberg equilibrium analysis in cases and controls was p = 0.93 and p = 0.23, respectively. No significant associations between genotype DD vs ID+II (OR = 0.56, 95% CI 0.17-1.87, p = 0.34) or II vs DD+ID (OR = 0.95, 95% CI, 0.43 - 2.12, p = 0.92) and essential hypertension were found

    Angiotensin-Converting Enzyme (ACE) genetic variation and longevity in Peruvian older people: a cross-sectional study

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    Background: Some studies have suggested that the insertion(I)/deletion(D) polymorphism of the Angiotensin-Converting Enzyme (ACE) gene may be associated with human longevity, especially in centenarians. However, this association is still controversial. Besides, there have been no studies in Peruvians. Aim: To describe the age distribution of the ACE polymorphism in a convenience sample of Peruvian older people. Subjects and methods: This was a cross-sectional study in 104 Geriatric Day Hospital patients in Lima, Per?. The ACE polymorphism was determined in all patients. For the purpose of association with age, the sample was divided into four categories: young (< 65), youngest-old (65?74), middle-old (75?84) and oldest-old (85 or more). Results: The distribution of genotype frequencies was consistent with a population in Hardy-Weinberg equilibrium (p?=?0.62). The number (%) of D/D, I/D and I/I genotypes in the young was 2 (14.3%), 3 (21.4%) and 9 (64.3%), respectively; in youngest-old: 4 (11.4%), 15 (42.9%) and 16 (45.7%); in middle-old: 6 (12.2%), 20 (40.8%) and 23 (46.9%); and in oldest-old: 0 (0.0%), 4 (66.7%) and 2 (33.3%). A chi-square analysis showed no significant differences in genotype distribution between age groups (p?=?0.647). Conclusion: No significant age differences were found in the distribution of the ACE polymorphism in this sample. Further studies with greater statistical power are recommended
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