Localization of a new neuroleptic in the pituitary gland of the rat

summary The¹⁴C-labelled, substituted benzamide neuroleptic Tiapride has been found to accumulate transiently in the pituitary gland of the rat following a single dose, and a prolonged retention of the drug was observed in the pars intermedia.     

Mice mutant for Egfr and Shp2 have defective cardiac semilunar valvulogenesis

Atrioventricular and semilunar valve abnormalities are common birth defects, but how cardiac valvulogenesis is directed remains largely unknown. During studies of genetic interaction between Egfr, encoding the epidermal growth factor receptor, and Ptpn11, encoding the protein-tyrosine-phosphatase Shp2, we discovered that Egfr is required for semilunar, but not atrioventricular, valve development. Although unnoticed in earlier studies, mice homozygous for the hypomorphic Egfr allele waved-2 (Egfrwa2/wa2) exhibit semilunar valve enlargement resulting from over-abundant mesenchymal cells. Egfr-/- mice (CD1 background) have similar defects. The penetrance and severity of the defects in Egfrwa2/wa2 mice are enhanced by heterozygosity for a targeted mutation of exon 2 of Ptpn11 (ref. 3). Compound (Egfrwa2/wa2:Ptpn11+/-) mutant mice also show premature lethality. Electrocardiography, echocardiography and haemodynamic analyses showed that affected mice develop aortic stenosis and regurgitation. Our results identify the Egfr and Shp2 as components of a growth-factor signalling pathway required specifically for semilunar valvulogenesis, support the hypothesis that Shp2 is required for Egfr signalling in vivo, and provide an animal model for aortic valve disease.     

Discovery of calcium in Mercury's atmosphere

The composition and evolutionary history of Mercury's crust are not well determined. The planet as a whole has been predicted to have a refractory, anhydrous composition: rich in Ca, Al, Mg and Fe, but poor in Na, K, OH, and S. Its atmosphere is believed to be derived in large part from the surface materials. A combination of effects that include impact vaporization (from infalling material), volatile evaporation, photon-stimulated desorption and sputtering releases material from the surface to form the atmosphere. Sodium and potassium have already been observed in Mercury's atmosphere, with abundances that require a volatile-rich crust. The sodium probably results from photon-stimulated desorption, and has a temperature of 1,500 K (ref. 10). Here we report the discovery of calcium in the atmosphere near Mercury's poles. The column density is very low and the temperature is apparently very high (12,000 K). The localized distribution and high temperature, if confirmed, suggest that the atmospheric calcium may arise from surface sputtering by ions, which enter Mercury's auroral zone. The low abundance of atmospheric Ca may indicate that the regolith is rarefied in calcium.     

Familial predisposition to Wilms' tumour does not map to the short arm of chromosome 11

Wilms' tumour of the kidney usually occurs sporadically, but can also segregate as an autosomal dominant trait with incomplete penetrance. Patients with the WAGR syndrome of aniridia, genitourinary anomalies, mental retardation and high risk of Wilms' tumour have overlapping deletions of chromosome 11p13 which has suggested a possible location for a Wilms' tumour locus. Moreover, many sporadic tumours have lost a portion of chromosome 11p. A second locus at 11p15 is implicated by association of the tumour with the Wiedemann-Beckwith syndrome and by tumour-specific losses of chromosome 11 confined to 11p15. Here we report a multipoint linkage analysis of a family segregating for Wilms' tumour, using polymorphic DNA markers mapped to chromosome 11p. The results exclude the predisposing mutation from both locations. In a second family, the 11p15 alleles lost in the tumour were derived from the affected parent, thus precluding this region as the location of the inherited mutation. These findings imply an aetiological heterogeneity for Wilms' tumour and raise questions concerning the general applicability of the carcinogenesis model that has been useful in the understanding of retinoblastoma.     

Insulin-like growth factor II receptor as a multifunctional binding protein

The primary structure of human insulin-like growth factor II receptor, predicted from the complementary DNA sequence, reveals a transmembrane receptor molecule with a large extracellular domain made up of fifteen repeat sequences and a small region homologous to the collagen-binding domain of fibronectin. The structural and biochemical features of the IGF-II receptor appear identical to those of the cation-independent mannose-6-phosphate receptor.     

低比转速混流式水轮机转轮上冠型线的优化方法

通过混流式水轮机转轮上冠型线的优化,以提高水轮机效率为目的,基于ISIGHT软件集成GAMBIT和ANSYS FLUENT16.0软件,采用实验设计的最优拉丁超立方(optimal Latin hypercube, OLH)方法提出了80组设计方案.然后运用ANSYS FLUENT16.0软件对各方案进行数值计算,以设计工况下的水轮机效率为目标函数,进而用响应面方法(response surface method,RSM)得到近似模型.最后结合粒子群优化(PSO)算法进行自动优化设计,提出一种低比转速混流式水轮机转轮上冠型线的优化设计方法.该方法应用于模型混流式水轮机转轮上冠型线的优化设计,结果表明:优化后水轮机水力效率提高0.35%,从而为混流式水轮机转轮上冠型线的优化设计提供了合理有效的途径.     

不同川贝母制剂镇咳、祛痰和抗炎作用实验研究

目的:观察不同川贝母制剂的镇咳、祛痰和抗炎药效作用,为川贝母相关制剂的开发提供科学依据.方法:分别建立小鼠氨水致咳模型、酚红排痰模型、蛋清致小鼠足肿胀炎症模型,以及二甲苯致小鼠耳肿胀炎症模型,观察川贝母片剂和川贝母膨化制剂对上述不同模型小鼠的镇咳、祛痰和抗炎药效作用.结果:川贝母片剂和膨化制剂均能明显或部分增加小鼠的酚红排泌量,抑制小鼠的耳部肿胀和足部肿胀,分别降低其肿胀率,显示出较好的抗炎和祛痰作用;与此同时,川贝母膨化制剂还能明显或部分减少氨水引起的小鼠咳嗽次数,显示出一定的镇咳作用.上述作用均优于川贝清肺糖浆及原料药.结论:川贝母片剂和膨化制剂具有一定的祛痰、镇咳和抗炎作用.