[Application of three methods in occupational health risk assessment of automobile 4S shop].

Objective: To choose various occupational health risk assessment of the mature methods at home and abroad respectively occupational health risk assessment was carried out on the 4s stores, to explore different risk assessment methods on the 4 s shop the applicability of the occupational health risk assessment. Methods: Chemical was applied on the harmful factors of occupational health risk assessment technology guideline in the composite index method, quantitative cancer risk assessment method using the guidelines for the harmful factors of occupational health risk assessment of chemical technology of composite index method, quantitative cancer risk assessment method, international commission on mining and metals (ICMM) occupational health risk assessment quantitative method and the occupational-disease-inductive operation classification to evaluate chemical factors in 4S store, Combined with on-site occupational health investigation to compare with the result of risk assessment and analysis of international mining and metals (ICMM) committee occupational health risk assessment quantitative method and the occupational-disease-inductive operation classification of 4S store to evaluate chemical factors, combined with on-site occupational health investigation comparison and analysis the result of the risk assessment. Results: Except for 6 times, the results of ICMM matrix method and comprehensive index method were consistent, which were all higher than job classification. The other results were job classification of >of ICMM matrix method >comprehensive index method or job classification of >of ICMM matrix method. Conclusion: When the concentration of occupational-disease-inductive factors is lower than 1/2 limit, the risk assessment results tend to be ICMM quantitative >composite index method >operation classification. When the occupational-disease-inductive factors were involved with triphenyl, the quantitative non-carcinogenic risk assessment method was more likely to reach the conclusion that the occupational health risk was unacceptable.

Distribution of vasopressin, oxytocin and vasoactive intestinal polypeptide in the hypothalamus and extrahypothalamic regions of tree shrews.

Vasopressin (VP), oxytocin (OXT) and vasoactive intestinal polypeptide (VIP) in the brain modulate physiological and behavioral processes in many vertebrates. Day-active tree shrews, the closest relatives of primates, live singly or in pairs in territories that they defend vigorously against intruding conspecifics. However, anatomy concerning peptidergic neuron distribution in the tree shrew brain is less clear. Here, we examined the distribution of VP, OXT and VIP immunoreactivity in the hypothalamus and extrahypothalamic regions of tree shrews (Tupaia belangeri chinensis) using the immunohistochemical techniques. Most of VP and OXT immunoreactive (-ir) neurons were found in the paraventricular nucleus (PVN) and supraoptic nucleus (SON) of the hypothalamus. In addition, VP-ir or OXT-ir neurons were scattered in the preoptic area, anterior hypothalamic areas, dorsomedial hypothalamic nucleus, stria terminalis, bed nucleus of the stria terminalis and medial amygdala. Interestingly, a high density of VP-ir fibers within the ventral lateral septum was observed in males but not in females. Both VP-ir and VIP-ir neurons were found in different subdivisions of the suprachiasmatic nucleus (SCN) with partial overlap. VIP-ir cells and fibers were also scattered in the cerebral cortex, anterior olfactory nucleus, amygdala and dentate gyrus of the hippocampus. These findings provide a comprehensive description of VIP and a detailed mapping of VP and OXT in the hypothalamus and extrahypothalamic regions of tree shrews, which is an anatomical basis for the participation of these neuropeptides in the regulation of circadian behavior and social behavior.

Cloning and expression of bovine prolactin cDNA in Escherichia coli.

Total mRNA isolated from bovine pituitary was used as a template to synthesize double-stranded cDNA with reverse transcriptase and E. coli DNA polymerase. Recombination was performed using pBR322 as the cloning vector and the oligo dG-tailed and oligo dC-tailed method. The recombinant plasmid was then introduced into E. coli to construct the cDNA library of bovine pituitary mRNA. The labelled synthetic bovine prolactin (bPrl) gene fragment was used as hybridization probe to screen the positive clones, which were then subjected to enzymatic mapping and DNA sequence analysis. The results demonstrate that the positive clones contain a full length bPrl cDNA sequence. The clones obtained were subsequently trimmed, linked to a tac promoter, introduced into E. coli JM103, and expressed under the induction of IPTG. The SDS-PAGE indicates the existence of expression product, and the result of ELISA shows that the product has the same immune activity as native bPrl.

The study on transgenic mice.

The structural gene coding for human growth hormone (hGH) was fused to the promoter of the mouse gene for metallothionein-1. These fusion genes were introduced into pronuclei of the fertilized eggs of mice by micro-injection. We have injected MT-hGH genes into 121 mouse eggs which were transferred into the oviducts of eleven pseudo-mothers. Seven out of eleven mothers gave birth. Forty-three litters were born. These litters were grown-up and their tails were cut for isolating the DNA. The DNA of each mouse was examined by dot hybridization and Southern blotting. We found that eighteen mice had incorporated the fusion genes and grew larger than control mice. Synthesis of human growth hormone was induced further by zinc, which normally induces metallothionein gene expression. We also isolated the RNA from the livers of transgenic mice. The RNA was hybridized with hGH gene. It showed that on the transcription level the hGH gene was transcribed into mRNA in the transgenic mice. Using the same method to examine the second and third generation of the transgenic mice, we found that the incorporated gene could be inherited for generations. But the body-weight of transgenic mice appeared to decrease in the progeny. The offspring obtained from different combinations of parents (carrying or not carrying hGH gene) were different.