1,771 research outputs found

    A combination of right ventricular hypertrabeculation/noncompaction and arrhythmogenic right ventricular cardiomyopathy: a syndrome?

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    A combination of ARVC and RV NVM/HVM, which is extremely rare, to our knowledge, is never reported. RV NVM/HVM could be the cause and consequence of ARVC, or RV NVM/HVM and ARVC could be a consequence of a certain undetermined cause. It must be kept in mind, however, that the interaction of NVM/HVM and ARVC could be in part of pathophysiology mechanism of the combination even if as a consequence of an underlying genetic factor

    Secondary contact and admixture between independently invading populations of the Western corn rootworm, diabrotica virgifera virgifera in Europe

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    The western corn rootworm, Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae), is one of the most destructive pests of corn in North America and is currently invading Europe. The two major invasive outbreaks of rootworm in Europe have occurred, in North-West Italy and in Central and South-Eastern Europe. These two outbreaks originated from independent introductions from North America. Secondary contact probably occurred in North Italy between these two outbreaks, in 2008. We used 13 microsatellite markers to conduct a population genetics study, to demonstrate that this geographic contact resulted in a zone of admixture in the Italian region of Veneto. We show that i) genetic variation is greater in the contact zone than in the parental outbreaks; ii) several signs of admixture were detected in some Venetian samples, in a Bayesian analysis of the population structure and in an approximate Bayesian computation analysis of historical scenarios and, finally, iii) allelic frequency clines were observed at microsatellite loci. The contact between the invasive outbreaks in North-West Italy and Central and South-Eastern Europe resulted in a zone of admixture, with particular characteristics. The evolutionary implications of the existence of a zone of admixture in Northern Italy and their possible impact on the invasion success of the western corn rootworm are discussed

    Próteses parciais fixas reforçadas por fibras: um estudo clínico retrospectivo preliminar

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    The aim of this study was to evaluate the clinical performance (retention rate) of fiber-reinforced composite fixed partial dentures (FPDs). Polyethylene fiber (Ribbond®) was used combined with restorative composite during FPDs fabrication. FPDs were placed in thirteen patients in a private clinic. Nineteen FPDs were evaluated. The prosthetic space was filled with only one pontic using extracted teeth (2 cases), acrylic resin teeth (11 cases), or with composite resin (6 cases), combined with Polyethylene fiber. The clinical criterion used was based on retention rate of FPDs. If FPDs were in function in the mouth at the time of examination without previous repair they were classified as Complete Survival (CS) restorations. A classification of Survival with Rebonding (SR) was assigned in the event of an adhesive failure, but after rebonding the FPD still remained under evaluation. Treatment was classified as a Failure (F) if the FPD restoration was lost. The time of evaluation was 41.15 months (±15.13). The FPDs evaluated were retained (CS=94.75%), and no failure was found except for in one situation which required rebonding (SR=5.25%). According to the survival estimation method of Kaplan-Meyer the mean survival time was 42.3 months. At the time of evaluation investigated, polyethylene-reinforced FPDs showed a favorable retention rate in preliminary data.O objetivo deste estudo foi avaliar a performance clínica (percentagem de retenção) de próteses parciais fixas reforçadas por fibras. Fibras de polietileno (Ribbond®) foram usadas em combinação com resina composta durante a confecção das próteses. Os tratamentos foram realizadas em 13 pacientes, em uma clínica privada., sendo que 19 próteses foram reavaliadas. O espaço protético era preenchido com um pôntico usando o próprio dente extraído (2 casos), dentes de acrílico (11 casos) ou confeccionados com resina composta (6 casos), em todas as situações eram empregadas fibras de polietileno. Os critérios clínicos usados foram baseados na percentagem de retenção das próteses parciais fixas. As próteses que estavam em função no momento da avaliação, sem nunca necessitar de qualquer reparo prévio, foram classificadas como sobrevivência completa (SC). A classificação de sobrevivência com nova colagem (SR) foi utilizada para os casos de falha adesiva, com posterior cimentação da peça, a qual permanecia em função. O tratamento era classificado como falha (F) quando a restauração era perdida. O tempo médio de avaliação foi de 41,15 meses (±15,13). Nenhum caso de falha foi detectado, em apenas um caso houve falha adesiva com posterior colagem da peça (SR=5,25%) e em 94.75% dos casos as próteses permaneciam em função.. De acordo com o método de sobrevida de Kaplan-Meyer o tempo médio de sobrevida foi de 42,3 meses. As próteses parciais fixas reforçadas por fibras mostraram uma percentagem de retenção favorável neste estudo preliminar

    Treatment with intravenous pamidronate is a good alternative in case of gastrointestinal side effects or contraindications for oral bisphosphonates

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    <p>Abstract</p> <p>Background</p> <p>In case of contraindications or intolerance during treatment with oral bisphosphonates (OB), administration of pamidronate intravenously is a widely used alternative.</p> <p>In this study we compared the effect on change in bone mineral density (BMD) of the spine and hip during long term treatment with pamidronate iv in comparison to OB.</p> <p>Methods</p> <p>We studied 61 patients receiving treatment for at least two years. In case of contraindications or intolerance (within 3 months) of an OB, pamidronate iv was started. BMD was measured on a Hologic 4500 and a Lunar DPX-IQ at the spine (L1-L4) and total hip.</p> <p>Results</p> <p>Thirty-one patients were enrolled in the OB group and 30 in the intravenous pamidronate group. Mean follow-up duration (SD) was 4.3 (1.3) years. We observed a significant increase (p < 0.001) in spinal BMD, both in the OB group (8.3%) as well as in the pamidronate iv group (6.1%), but no significant difference in BMD change between the OB and pamidronate iv groups. At the hips, we observed a tendency to increased BMD in both groups, 1.1% in the OB and 1.4% in the pamidronate iv group.</p> <p>Conclusion</p> <p>We conclude that intravenous pamidronate is a good alternative for oral bisphosphonates in the treatment of osteoporosis in patients with contraindications or intolerance during treatment with oral bisphosphonates.</p

    State based model of long-term potentiation and synaptic tagging and capture

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    Recent data indicate that plasticity protocols have not only synapse-specific but also more widespread effects. In particular, in synaptic tagging and capture (STC), tagged synapses can capture plasticity-related proteins, synthesized in response to strong stimulation of other synapses. This leads to long-lasting modification of only weakly stimulated synapses. Here we present a biophysical model of synaptic plasticity in the hippocampus that incorporates several key results from experiments on STC. The model specifies a set of physical states in which a synapse can exist, together with transition rates that are affected by high- and low-frequency stimulation protocols. In contrast to most standard plasticity models, the model exhibits both early- and late-phase LTP/D, de-potentiation, and STC. As such, it provides a useful starting point for further theoretical work on the role of STC in learning and memory

    Limits to the Rate of Adaptive Substitution in Sexual Populations

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    In large populations, many beneficial mutations may be simultaneously available and may compete with one another, slowing adaptation. By finding the probability of fixation of a favorable allele in a simple model of a haploid sexual population, we find limits to the rate of adaptive substitution, , that depend on simple parameter combinations. When variance in fitness is low and linkage is loose, the baseline rate of substitution is , where is the population size, is the rate of beneficial mutations per genome, and is their mean selective advantage. Heritable variance in log fitness due to unlinked loci reduces by under polygamy and under monogamy. With a linear genetic map of length Morgans, interference is yet stronger. We use a scaling argument to show that the density of adaptive substitutions depends on , , , and only through the baseline density: . Under the approximation that the interference due to different sweeps adds up, we show that , implying that interference prevents the rate of adaptive substitution from exceeding one per centimorgan per 200 generations. Simulations and numerical calculations confirm the scaling argument and confirm the additive approximation for ; for higher , the rate of adaptation grows above , but only very slowly. We also consider the effect of sweeps on neutral diversity and show that, while even occasional sweeps can greatly reduce neutral diversity, this effect saturates as sweeps become more common—diversity can be maintained even in populations experiencing very strong interference. Our results indicate that for some organisms the rate of adaptive substitution may be primarily recombination-limited, depending only weakly on the mutation supply and the strength of selection
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