Regulation of nitrogen catabolic enzymes in chick liver -- effects of amino acids

It is well-known that in the chick, dietary protein increases the levels of several hepatic enzymes that are involved in nitrogen metabolism and excretion. However, the biochemical mechanism of this response is essentially unknown. The experiments presented in this paper show that the chick is responding to alpha-amino nitrogen and not to any specific amino acid. Furthermore, it is shown that this system responds to endogenous sources of nitrogen as well as dietary protein and that the xanthine dehydrogenase response involves regulation of enzyme synthesis without changing the rate of degradation.     

Clinical picture and dynamics of psychopathologic disorders in subacute leuko-and panencephalitis

The report contains the results of clinico-dynamic studies of mental disorders in patients with Schilder's leukoencephalitis and subacute sclerosing panencephalitis after van-Bogart. The authors come to the conclusion that only parallel comparisons of the psychopathological symptomatology with focal neurological signs and a simultaneous study of the EEG and other paraclinical indices may facilitate the differential diagnosis of encephalitis.     

Polymorphisms in the bovine lactoferrin promoter are associated with reproductive performance and somatic cell count

Lactoferrin plays an important role in the innate immune system, with well-characterized antibacterial, antiviral, and immune modulatory properties. The objective of this study was to determine the allele and haplotype frequency of polymorphisms at positions −586, −190, and −28 of the bovine lactoferrin promoter in Holstein-Friesians and to quantify their association with performance using phenotypic data on progeny from 848 sires. Associations between genotypes and performance were quantified using weighted mixed models with genotyped individuals included as a random effect, and average expected relationships among individuals accounted for through a numerator relationship matrix. The dependent variables were daughter yield deviation for production traits and deregressed predicted transmitting ability for calving interval and functional survival. The C to T polymorphism at −586, which distorts a putative activating protein 2 (AP-2) binding site, was associated with a shorter calving interval and higher somatic cell score. The G to A polymorphism at −190, located in a putative selective promoter factor 1 (SP-1) binding site, was associated with a longer calving interval and decreased functional survival. A third polymorphism (A to C) at position −28, found within the noncanonical TATA box, had a tendency to associate with functional survival. On the basis of the data we proposed a haplotype combination that was associated with improved reproductive performance in the Holstein-Friesian breed. We hypothesized that the observable phenotypic associations with lactoferrin promoter polymorphisms can potentially be explained by allele-specific differences in constitutive or inducible levels of gene expression. The lack of a pleiotropic effect of the single nucleotide polymorphisms studied on both fertility and milk production traits strengthens the importance of these polymorphisms, or at least the lactoferrin promoter, in selection for improved fertility.     

Self-inhibition in amiloride-sensitive sodium channels in taste receptor cells

Recognition of antigen by T cells requires the formation of a specialized junction between the T cell and the antigen-presenting cell. This junction is generated by the recruitment and the exclusion of specific proteins from the contact area. The mechanisms that regulate these events are unknown. Here we demonstrate that ligand engagement of the adhesion molecule, CD2, initiates a process of protein segregation, CD2 clustering, and cytoskeletal polarization. Although protein segregation was not dependent on the cytoplasmic domain of CD2, CD2 clustering and cytoskeletal polarization required an interaction of the CD2 cytoplasmic domain with a novel SH3-containing protein. This novel protein, called CD2AP, is likely to facilitate receptor patterning in the contact area by linking specific adhesion receptors to the cytoskeleton.     

Loss of H19 imprinting and up-regulation of H19 and SNRPN in a case with malignant mixed Müllerian tumor of the uterus

An unusual clinical presentation of a patient with neuronal intestinal dysplasia is presented. A 46-year-old male noted a palpable mass in the right lower quadrant of his abdomen for two months. A computed axial tomographic scan showed a thickened wall of the cecum with a tumor-like appearance. The excised specimen consisted of a mass caused by the thickened, edematous wall of the dilated cecum and appendix. The wall of the cecum and appendix measured up to 2.5 and 0.8 cm, respectively, in thickness. Microscopic studies showed extensive hyperplasia and hypertrophy of the ganglia and nerve plexuses and hypertrophy of the muscularis propria, consistent with neuronal intestinal dysplasia.     

浅谈新建本科院校化学类实验教学质量的保障

为确保化学类专业实验教学质量,实现新建本科院校培养高级应用型人才的培养目标,构建了一套化学类专业实验教学质量保障体系,并在实践中取得了良好的成效。     

基于信息检索课的大学生信息检索行为调查研究

信息检索课程的系统化讲授,对于大学生优化信息检索行为,提高信息检索使用效率具有不容忽视的教学辅助作用.立足问卷调查形成的一系列相关数据,探讨大学生信息检索行为存在问题,最终在课程教学中提出优化大学生信息检索的对策:明确信息检索目的,提升实施效果;有效提升检索行为实施频率,增强综合质量;使得信息获取多元发展,优化成效凸显...     

天然气加热炉的腐蚀原因及防护对策

天然气加热炉的腐蚀是一个普遍现象.本文从引起腐蚀的因素人手,详细剖析腐蚀发生的原因,提出监测和治理相结合的方法,系统地介绍了几种常用的防腐技术,包括添加缓蚀剂、使用耐腐蚀材料、界面涂层、电化学防腐及其它相关防腐技术.