Autosomal dominant cerulean cataract is associated with a chain termination mutation in the human beta-crystallin gene CRYBB2

Congenital cataracts are a common major abnormality of the eye that frequently cause blindness in infants. At least a third of all cases are familial; autosomal dominant congenital cataract (ADCC) appears to be the most common familial form in the Western world. Cerulean cataracts have peripheral bluish and white opacifications in concentric layers with occasional central lesions arranged radially. Although the opacities may be observed during fetal development and childhood, usually visual acuity is only mildly reduced until adulthood, when lens extraction is generally necessary. We have been studying a family (ADCC- 1) with cerulean blue ADCC, in which the affected daughter of a first cousin mating was presumed to be homozygous for the cataract gene. Recently, we mapped an ADCC gene in this family to a region of chromosome 22 containing three beta-crystallin genes. Here we report that a chain-termination mutation in CRYBB2 is associated with ADCC in this family.      

研究环境香烟烟雾暴露方法上必需考虑的问题

本文对在美国所进行的不吸烟者环境香烟烟雾（ＥＴＳ）暴露水平的大样本研究作了综述。内容包括取样地点的特定要求，收集样本的时间问题，评估ＥＴＳ暴露的合理标记物，以及用独立的方法去核实被检者自述ＥＴＳ暴露情况。以下是一些最重要的结论：（ａ）ＥＴＳ暴露的实际浓度比以前各地测量结果或短期暴露结果的预期浓度为低。（ｂ）家庭中的接触比工作场所更重要（浓度×暴露时间），约高２～１０倍。（ｃ）被检者报告吸烟情况的错误率比美国环保署（ＥＰＡ）先前所估计的高。（ｄ）用唾液古丁（Ｃｏｔｉｎｉｎｅ）含量来评估ＥＴＳ中尼古丁暴露的定量指标并不合适，因有个体差异     

Glutamate acting at NMDA receptors stimulates embryonic cortical neuronal migration

During cortical development, embryonic neurons migrate from germinal zones near the ventricle into the cortical plate, where they organize into layers. Mechanisms that direct neuronal migration may include molecules that act as chemoattractants. In rats, GABA, which localizes near the target destination for migrating cortical neurons, stimulates embryonic neuronal migration in vitro. In mice, glutamate is highly localized near the target destinations for migrating cortical neurons. Glutamate-induced migration of murine embryonic cortical cells was evaluated in cell dissociates and cortical slice cultures. In dissociates, the chemotropic effects of glutamate were 10-fold greater than the effects of GABA, demonstrating that for murine cortical cells, glutamate is a more potent chemoattractant than GABA. Thus, cortical chemoattractants appear to differ between species. Micromolar glutamate stimulated neuronal chemotaxis that was mimicked by microM NMDA but not by other ionotropic glutamate receptor agonists (AMPA, kainate, quisqualate). Responding cells were primarily derived from immature cortical regions [ventricular zone (vz)/subventricular zone (svz)]. Bromodeoxyuridine (BrdU) pulse labeling of cortical slices cultured in NMDA antagonists (microM MK801 or APV) revealed that antagonist exposure blocked the migration of BrdU-positive cells from the vz/svz into the cortical plate. PCR confirmed the presence of NMDA receptor expression in vz/svz cells, whereas electrophysiology and Ca2+ imaging demonstrated that vz/svz cells exhibited physiological responses to NMDA. These studies indicate that, in mice, glutamate may serve as a chemoattractant for neurons in the developing cortex, signaling cells to migrate into the cortical plate via NMDA receptor activation.     

Ruptured ectopic pregnancy: risk factors for a life-threatening condition

Introduction  Ectopic pregnancy is a significant cause of maternal morbidity and mortality. The widely used features to establish the diagnosis of ectopic pregnancy are not always sufficient to predict rupture. Problem  To determine the risk factors for rupture of an ectopic pregnancy to help physicians identify those women who are at greatest risk. Materials and methods  The study group comprises the cases of ectopic pregnancy who were treated in the gynecologic department of the General Hospital “George Gennimatas” in Athens, Greece, from January 1988 to December 2006. The following parameters were retrospectively examined: rupture status, past history of pelvic infection or ectopic pregnancy, use of IUCD, operations for infertility treatment/tubal surgery, parity and gestational age. The study group was divided into two subgroups: ruptured ectopic pregnancies and unruptured ectopic pregnancies. Where appropriate, Student’s t test, Mann–Whitney–Wilcoxon test for independent samples, Pearson’s chi-square and Fisher’s exact test were applied. Statistical analysis was performed with STATA 8.0 statistical software. Results  Two hundred and twenty-three cases of ectopic pregnancy were retrieved in the studied period. One hundred and forty-four (65%) of them were cases with ruptured ectopic pregnancies and 79 (35%) were cases with unruptured ectopic pregnancies. Fifty-five of the 144 patients (38.2%) with ruptured ectopic pregnancy and 18 of the 79 (22.8%) patients with unruptured ectopic pregnancy had a past history of ectopic pregnancy (P = 0.019, Pearson’s chi-square). Moreover, there was a statistically significant positive association between rupture and parity (1.19 ± 1.02 for ruptured cases vs. 0.85 ± 0.89 for unruptured cases; P = 0.015, Mann–Whitney–Wilcoxon test for independent samples). A positive association of borderline significance existed between rupture and gestational age (53.9 ± 4.7 vs. 52.9 ± 4.9 days; P = 0.093, Mann–Whitney–Wilcoxon test for independent samples). No statistically significant associations were found concerning past history of pelvic infection, use of IUCD and operations for infertility treatment–tubal surgery. Conclusions  Previous history of ectopic pregnancy and parity seem to be significant risk factors for rupture of an ectopic pregnancy.