Immunohistochemical detection of a substance resembling growth hormone-releasing factor in the brain of the rainbow trout (Salmo gairdneri)

We studied the distribution of an immunoreactive substance resembling growth hormone-releasing factor (GRF) in the hypothalamus and pituitary gland of the rainbow trout by immunofluorescence methods. The GRF-like immunoreactive perikaryon was observed in colchicine-treated fish. The majority of GRF-containing neurons were located in the nucleus lateral tuberis; others were located in the caudal part of the preoptic nucleus of the hypothalamus. The GRF-like immunoreactive neuronal processes projected into the pars distalis via the pars nervosa of the pituitary gland. The distribution of the GRF-like immunoreactive substance in the hypothalamus and pituitary gland suggests that GRF plays a physiological role in the regulation of growth hormone release from the pituitary gland of rainbow trout, as it does in mammals.     

Development of City Transport System and Two-wheel Vehicles

Based on the study on the city transport systems of some typical cities worldwide, this paper put forward that each city transport system has its own development mode, which is influenced by the city development plan, economic development level, traveling vehicle composition etc.. When some problems occur, such as the congestions caused by contradiction between the road capacity and vehicle composition, the city transport system may come into temporary maturity period. If the improvement for road system is limited meanwhile, optimized structure of vehicle composition should be an effective solution in this case. With the development of economy-internationalization, the development speed of city transport modernization is rapid. When traveling easiness is conflicting with efficiency, the advantages of public transport system become more obvious. Correspondingly, the superiority of two-wheel vehicles will reappear. Though the important function of two-wheel vehicles for alleviating city traffic problems i     

Molecular structure of the chick cerebellar kainate-binding subunit of a putative glutamate receptor

Kainate receptors mediate some of the excitatory transactions carried out in the central nervous system by the neurotransmitter glutamate. They are involved in neurotoxicity, possibly in neurodegenerative disorders and it has been suggested that they have a role in long-term potentiation. Kainate receptors are present both on neuronal and glial cell membranes where they regulate the gating of a voltage-independent ion channel. Nothing is known about their molecular structure. Taking advantage of the unusually high abundance of 3H-kainate binding sites in the chick cerebellum, we have isolated an oligomeric protein that displays a pharmacological profile similar to that of a kainate receptor, and have demonstrated, using the monoclonal antibody IX-50, that this protein is composed of a single polypeptide of Mr 49,000 which harbours the specific kainate recognition site. The structure of this kainate binding protein (KBP) is also of interest because of its exclusive cerebellar localization on Bergmann glial membrane in close proximity to established glutamatergic synapses. We now report the isolation of the complementary DNA containing the complete coding region of the kainate binding protein. The predicted structure of the mature protein has four putative transmembrane domains with a topology analogous to that found in the superfamily of ligand-gated ion channels. This raises the possibility, that kainate binding protein may form part of an ion channel and may be a subunit of a kainate subtype of glutamate receptor.     

A double-switch system regulates male courtship behavior in male and female Drosophila melanogaster

Current models describe male-specific fruitless (fruM) as a genetic 'switch' regulating sexual behavior in Drosophila melanogaster, and they postulate that female (F) and male (M) doublesex (dsx) products control body sexual morphology. In contradiction to this simple model, we show that dsx, as well as fruM and non-sex-specific retained (retn), affect both male and female sexual behaviors. In females, both retn and dsxF contribute to female receptivity, and both genes act to repress male-like courtship activity in the presence or absence of fruM. In males, consistent with the opposing functions of dsxM and dsxF, dsxM acts as a positive factor for male courtship. retn also acts counter to fruM in the development of the male-specific muscle of Lawrence. Molecularly, retn seems to regulate sexual behavior via a previously described complex that represses zerknullt. Thus, we show that fru and dsx together act as a 'switch' system regulating behavior in the context of other developmental genes, such as retn.     

Mutations in the human delta homologue, DLL3, cause axial skeletal defects in spondylocostal dysostosis

Spondylocostal dysostosis (SD, MIM 277300) is a group of vertebral malsegmentation syndromes with reduced stature resulting from axial skeletal defects. SD is characterized by multiple hemivertebrae, rib fusions and deletions with a non-progressive kyphoscoliosis. Cases may be sporadic or familial, with both autosomal dominant and autosomal recessive modes of inheritance reported. Autosomal recessive SD maps to a 7.8-cM interval on chromosome 19q13.1-q13.3 that is homologous with a mouse region containing a gene encoding the Notch ligand delta-like 3 (Dll3). Dll3 is mutated in the X-ray-induced mouse mutant pudgy (pu), causing a variety of vertebrocostal defects similar to SD phenotypes. Here we have cloned and sequenced human DLL3 to evaluate it as a candidate gene for SD and identified mutations in three autosomal recessive SD families. Two of the mutations predict truncations within conserved extracellular domains. The third is a missense mutation in a highly conserved glycine residue of the fifth epidermal growth factor (EGF) repeat, which has revealed an important functional role for this domain. These represent the first mutations in a human Delta homologue, thus highlighting the critical role of the Notch signalling pathway and its components in patterning the mammalian axial     

Rapid Manufacturing of Non-Assembly Complex Micro-Devices by Microstereolithography

This paper introduces a non-assembly manufacturing case with microstereolithography technology. The design and manufacturing process of a pneumatic thrust bearing is described, and a special tessellation method is developed to further improve the capability of the manufacturing system thus bigger products can also be easily manufactured. Implemented in a layer-by-layer fashion, stereolithography has been used for the rapid manufacturing of complex devices, and it avoids the expensive assembly process in the traditional manufacturing. This paper presents that microstereolithography can produce high-resolution products with intricate details, small openings, and smooth surfaces. The potential of the microstereolithograhy technique is explored for the rapid manufacturing of small and complex objects.     

Close genetic linkage between X-linked retinitis pigmentosa and a restriction fragment length polymorphism identified by recombinant DNA probe L1.28

Retinitis pigmentosa (RP) is a group of retinal degeneration characterized by progressive visual field loss, night blindness and pigmentary retinopathy. Its prevalence is in the region of 1-2 in 5,000 of the general population, making it one of the commoner causes of blindness in early and middle life. Although 36-48% of RP patients are isolated cases, the remainder show autosomal dominant, autosomal recessive or X-linked modes of inheritance. The X-linked variety ( XLRP ) is found in 14-22% of RP families in the UK. In the present study, X chromosome-specific recombinant DNA probes which can detect restriction fragment length polymorphisms have been used to localize the XLRP gene(s) to a subregion of the X chromosome using linkage analysis. One of the probes, L1.28, has been shown to be closely linked to XLRP in five kindreds, with 95% confidence limits of 0-15 centimorgans (maximum LOD score of 7.89 at a distance of 3 centimorgans). This suggests that the XLRP locus lies on the proximal part of the short arm of the X chromosome. This probe is potentially useful for carrier detection and early diagnosis in about 40% of cases, provided that genetic heterogeneity can be excluded by analysis of further families.