Thrombotic genetic risk factors and warfarin pharmacogenetic variants in São Miguel's healthy population (Azores)

<p>Summary</p> <p>Background</p> <p>The Azorean population presents the highest standardized mortality rate for cardiovascular diseases (CVD) when compared to mainland Portugal and other populations. Since thrombosis is a common cause of CVD, we assessed four polymorphisms in three thrombotic risk genes – <it>F5 </it>(G1691A), <it>F2 </it>(G20210A) and <it>MTHFR </it>(C677T, A1298C), in 469 healthy blood donors from São Miguel Island (Azores). We also analysed the <it>CYP2C9 </it>(C430T, A1075C) and <it>VKORC1 </it>(G1639A) variants in fifty-eight individuals with predisposition to thrombosis (possessing at least one variation in <it>F5 </it>or <it>F2 </it>genes and one in <it>MTHFR</it>) to evaluate their warfarin drug response genetic profiles.</p> <p>Results</p> <p>Among the 469 individuals, the data showed that thrombotic risk allele frequencies – 1691A (4.9%), 20210A (1.8%), 677T (41.7%) and 1298C (24.8%) – were similar to other Caucasians, but significantly different from mainland Portuguese (χ², <it>p </it>< 0.001). The combined analysis of these variants identified twenty-two different genetic profiles (genotype order: <it>F5</it>, <it>F2</it>, <it>MTHFR </it>C677T and A1298C). Complete homozygosity for all wild-type alleles (GG GG CC AA) was present in 11.7%, being GG GG CT AA (22.4%) the most frequent profile. The results also demonstrated that 12.4% (58 out of 469) of São Miguel islanders have increased genetic predisposition to thrombosis. Subsequently, we evaluated these individuals for their warfarin response genetic profiles. The data showed that seven out of fifty-eight individuals are poor metabolizers (two with <it>CYP2C9</it>*2/*2 and five with <it>CYP2C9</it>*2/*3 genotypes). <it>VKORC1 </it>polymorphism analysis identified twelve individuals (20.7%) with AA genotype, who probably will require lower doses of warfarin. The joint analysis of <it>CYP2C9 </it>and <it>VKORC1 </it>revealed that 79.3% (46 out of 58) of the individuals carry at least one polymorphism in these genes. Within these, twenty-five individuals (43.1%) need intermediate and/or low doses of warfarin, if treatment is started.</p> <p>Conclusion</p> <p>The present study demonstrated, for the first time, that São Miguel, and possibly the Azores population, shows significant differences on allele frequencies of thrombotic risk factors when compared to mainland Portugal. This research constitutes a primary approach for future studies on CVD, as well as for the implementation of warfarin dosing protocols using the patient's genotypic information.</p

Diagnosis of Human Leptospirosis in a Clinical Setting: Real-Time PCR High Resolution Melting Analysis for Detection of Leptospira at the Onset of Disease:

Currently, direct detection of Leptospira can be done in clinical laboratories by conventional and by real-time PCR (qRT-PCR). We tested a biobank of paired samples of serum and urine from the same patient (202 patients) presenting at the hospital in an area endemic for leptospirosis using qRT-PCR followed by high resolution melting (HRM) analysis. The results were compared with those obtained by conventional nested PCR and with the serologic gold standard microscopic agglutination test (MAT). Differences were resolved by sequencing. qRT-PCR-HRM was positive for 46 of the 202 patients (22.7%, accuracy 100%) which is consistent with known prevalence of leptospirosis in the Azores. MAT results were positive for 3 of the 46 patients (6.5%). Analysis of paired samples allowed us to identify the illness point at which patients presented at the hospital: onset, dissemination or excretion. The melting curve analysis of Leptospira species revealed that 60.9% (28/46) of patients were infected with L. interrogans and 39.1% (18/46) were infected with L. borgpetersenii, both endemic to the Azores. We validated the use of qRT-PCR-HRM for diagnosis of leptospirosis and for identification of the Leptospira species at the earliest onset of infection in a clinical setting, in less than 2 hours.publishersversionpublishe

Minimal Mass Matrices for Dirac Neutrinos

We consider the possibility of neutrinos being Dirac particles and study minimal mass matrices with as much zero entries as possible. We find that up to 5 zero entries are allowed. Those matrices predict one vanishing mass state, CP conservation and U_{e3} either zero or proportional to R, where R is the ratio of the solar and atmospheric \Delta m^2. Matrices containing 4 zeros can be classified in categories predicting U_{e3} = 0, U_{e3} \neq 0 but no CP violation or |U_{e3}| \neq 0 and possible CP violation. Some cases allow to set constraints on the neutrino masses. The characteristic value of U_{e3} capable of distinguishing some of the cases with non-trivial phenomenological consequences is about R/2 \sin 2 \theta_{12}. Matrices containing 3 and less zero entries imply (with a few exceptions) no correlation for the observables. We outline models leading to the textures based on the Froggatt-Nielsen mechanism or the non-Abelian discrete symmetry D_4 \times Z_2.Comment: 32 pages, 3 figures. Comments and references added. To appear in JHE

Fitting Neutrino Physics with a U(1)_R Lepton Number

We study neutrino physics in the context of a supersymmetric model where a continuous R-symmetry is identified with the total Lepton Number and one sneutrino can thus play the role of the down type Higgs. We show that R-breaking effects communicated to the visible sector by Anomaly Mediation can reproduce neutrino masses and mixing solely via radiative contributions, without requiring any additional degree of freedom. In particular, a relatively large reactor angle (as recently observed by the Daya Bay collaboration) can be accommodated in ample regions of the parameter space. On the contrary, if the R-breaking is communicated to the visible sector by gravitational effects at the Planck scale, additional particles are necessary to accommodate neutrino data.Comment: 19 pages, 3 figures; v2: references added, constraints updated, overall conclusions unchange

Evaluation of Bacteria and Fungi DNA Abundance in Human Tissues

Whereas targeted and shotgun sequencing approaches are both powerful in allowing the study of tissue-associated microbiota, the human: microorganism abundance ratios in tissues of interest will ultimately determine the most suitable sequencing approach. In addition, it is possible that the knowledge of the relative abundance of bacteria and fungi during a treatment course or in pathological conditions can be relevant in many medical conditions. Here, we present a qPCR-targeted approach to determine the absolute and relative amounts of bacteria and fungi and demonstrate their relative DNA abundance in nine different human tissue types for a total of 87 samples. In these tissues, fungi genomes are more abundant in stool and skin samples but have much lower levels in other tissues. Bacteria genomes prevail in stool, skin, oral swabs, saliva, and gastric fluids. These findings were confirmed by shotgun sequencing for stool and gastric fluids. This approach may contribute to a more comprehensive view of the human microbiota in targeted studies for assessing the abundance levels of microorganisms during disease treatment/progression and to indicate the most informative methods for studying microbial composition (shotgun versus targeted sequencing) for various samples types

Systematic review with meta-analysis: cytokines in fibromyalgia syndrome

<p>Abstract</p> <p>Background</p> <p>To perform a systematic review and meta-analysis on cytokine levels in patients with fibromyalgia syndrome (FMS).</p> <p>Methods</p> <p>Through December 2010 we systematically reviewed the databases PubMed, MEDLINE, and PsycINFO and screened the reference lists of 22 review articles for suitable original articles. Original articles investigating cytokines in patients with FMS were included. Data were extracted by two independent authors. Differences of the cytokine levels of FMS patients and controls were summarized by standardized mean differences (SMD) using a random effects model. Study quality was assessed applying methodological scores: modified Center of Evidence Based Medicine, Newcastle-Ottawa-Scale, and Würzburg Methodological Quality Score.</p> <p>Results</p> <p>Twenty-five articles were included investigating 1255 FMS patients and 800 healthy controls. Data of 13/25 studies entered meta-analysis. The overall methodological quality of studies was low. The results of the majority of studies were not comparable because methods, investigated material, and investigated target cytokines differed. Systematic review of the selected 25 articles revealed that FMS patients had higher serum levels of interleukin (IL)-1 receptor antagonist, IL-6, and IL-8, and higher plasma levels of IL-8. Meta-analysis of eligible studies showed that FMS patients had higher plasma IL-6 levels compared to controls (SMD = -0.34 [-0.64, -0.03] 95% CI; p = 0.03). The majority of investigated cytokines were not different between patients and controls.</p> <p>Conclusions</p> <p>The pathophysiological role of cytokines in FMS is still unclear. Studies of higher quality and with higher numbers of subjects are needed.</p

Genomics and epidemiology for gastric adenocarcinomas (GE4GAC): a Brazilian initiative to study gastric cancer

Abstract Gastric cancer (GC) is the fifth most common type of cancer worldwide with high incidences in Asia, Central, and South American countries. This patchy distribution means that GC studies are neglected by large research centers from developed countries. The need for further understanding of this complex disease, including the local importance of epidemiological factors and the rich ancestral admixture found in Brazil, stimulated the implementation of the GE4GAC project. GE4GAC aims to embrace epidemiological, clinical, molecular and microbiological data from Brazilian controls and patients with malignant and pre-malignant gastric disease. In this letter, we summarize the main goals of the project, including subject and sample accrual and current findings