Regional left atrial voltage in patients with atrial fibrillation

BACKGROUND: Regional differences in fibrosis, particularly related to the posterior wall and septum, may be important in atrial fibrillation (AF). Using electroanatomic mapping, voltage can be used as a measure of fibrosis. OBJECTIVES: The purpose of this study was to determine if patients with AF have disproportionately lower voltage in the septal and posterior walls of the left atrium. METHODS: Sinus rhythm left atrial electroanatomic maps were used in serial patients presenting for left atrial ablation of AF (8-mm tip). Patients undergoing left atrial mapping for focal atrial tachycardia (AT) were used as a comparison group (4-mm tip). Animal experiments were performed to assess the influence of ablation catheter tip size on voltage amplitude. RESULTS: The posterior and septal walls exhibited the lowest voltages in both groups. Compared with the anterior wall, there was a 3.78-fold greater odds of finding a low-voltage point (<0.5 mV) in the septum (P <.001) and a 3.37-fold greater odds of finding a low-voltage point in the posterior wall (P <.001) in the AF patients; the proportion of low-voltage points by region were not significantly different in the AT group. In the animal model, the mean voltage obtained from an 8-mm ablation catheter was significantly higher (0.30 +/- 0.17 mV) than that obtained from the same points using a 4-mm catheter (0.22 +/- 0.17, P = .05). CONCLUSION: Regional differences in voltage are present in patients with atrial arrhythmias, with AF patients exhibiting significantly more low-voltage areas in the septum and posterior walls.     

<Emphasis Type="Italic">TCF7L2</Emphasis>variant genotypes and type 2 diabetes risk in Brazil: significant association,but not a significant tool for risk stratification in the general population

Background  

Genetic polymorphisms of the TCF7L2 gene are strongly associated with large increments in type 2 diabetes risk in different populations worldwide. In this study, we aimed to confirm the effect of the TCF7L2 polymorphism rs7903146 on diabetes risk in a Brazilian population and to assess the use of this genetic marker in improving diabetes risk prediction in the general population.     

Fanconi's anemia treated by allogeneic marrow transplantation

Eight patients with Fanconi's anemia were given cyclophosphamide alone (seven patients) or combined with procarbazine and antithymocyte globulin (one patient) followed by marrow grafts from HLA-identical siblings. All patients had engraftment. Seven developed acute and three chronic graft-versus-host disease (GVHD). Three patients died with GVHD and infectious complications (days 19, 56, and 82) and one with an intracerebral hemorrhage (day 540). Four patients are surviving 647- 3435 days after grafting, two are well, and two have chronic GVHD that is improving. These results show that Fanconi's anemia can be treated successfully by allogeneic marrow transplantation.     

Preliminary evidence for a role of apolipoprotein E alleles in identifying haemodialysis patients at high vascular risk

Conventional risk factors have very low predictive power in identifying haemodialysis patients at high risk of vascular accidents. A role for apolipoprotein E isotypes was looked for in a small, but rigorously defined, cohort of longterm haemodialysis patients. In individuals with high vascular risk, as identified by higher common carotid intima/media thickness, we found an excess of apolipoprotein E4 alleles. This preliminary result requires confirmation in large patient cohorts.      

新缩瞳剂包公藤甲素人工合成研究

包公藤甲素是从包公藤(Erycibe obtusifolia Benth.)茎中提得的一个新莨菪烷生物碱,具有强烈的缩瞳作用,临床用于治疗青光眼。本文报道用合成的6β-乙酰氧基托品酮为原料,经卤代、水解、还原和N-去甲基化等反应合成包甲素(8)。经光谱测定证实8与天然包甲素的结构完全一致。合成品系外消旋体,其作用机理与天然品相同,而强度则减半。     

4p16.3 haplotype modifying age at onset of Huntington disease

Huntington disease (HD) is caused by an expanded CAG repeat sequence in the HD gene. Although the age at onset is correlated to the CAG repeat length, this correlation only explains approximately half of the variation in onset age. Less variation between siblings indicates that the variation is, in part, explained by genetic modifiers. We analyzed polymorphic loci within or close to the HD gene on the HD chromosome in Danish HD patients. We found one specific haplotype segregating with later age at onset, compared with patients with similar CAG repeat length and another haplotype. The nine Danish families in the study carrying this haplotype most likely have a common founder. Several of the polymorphic loci displayed alleles that may be specific to the late-onset haplotype, implicating that from this study we cannot determine which of the loci tested (or other polymorphic loci in this chromosomal area) do in fact contain genetic modifiers of age at onset.