[Analysis of dust monitoring results of dust exposure enterprises in Shenxian from 2017 to 2020].

Objective: In order to understand the dust concentration in the workplace of dust exposure enterprises in Shenxian. To evaluate the degree of occupational hazard factors of dust exposure enterprises. And provide basis for the formulation of occupational protection standards and management system of dust exposure enterprises. Methods: In February 2022, the dust concentration monitoring data of 89 dust exposure enterprises from 2017 to 2020 by the Shenxian Center for Disease Control and Prevention were collected, and the qualified rates of dust concentration detection of dust exposure enterprises in different years, dust types and enterprise sizes were analyzed. Results: A total of 89 dust enterprises were monitored from 2017 to 2020, 2132 dust samples were collected, and 1818 qualified samples were taken, with a total qualified rate of 85.3%. From 2017 to 2020, the dust detection qualified rates showed a year-by-year increase trend, 78.7% (447/568), 84.1% (471/560), 88.6% (418/472) and 90.6% (482/532), respectively, with statistically significant differences (χ(2)=36.27, P=0.003). The differences in the qualified rates of dust detection samples of silicon dust (66.1%, 41/62), grain dust (86.7%, 1549/1786), cotton dust (84.1%, 106/126) and wood dust (77.2%, 122/158) were statistically significant (χ(2)=29.66, P=0.002). The qualified rate of dust samples in large and medium-sized enterprises (95.1%, 1194/1256) was higher than that of small-sized enterprises (71.2%, 624/876), and the difference was statistically significant (χ(2)=1584.40, P=0.001) . Conclusion: The qualified rate of dust concentration monitoring results of dust exposure enterprises in Shenxian showed an increase trend year by year, while the pualified rate of dust concentration monitoring in small-sized enterprises was low, and the occupational hazard of silica dust was still severe.

[Factors affecting the recovery of cholinesterase activity in patients with acute chlorpyrifos poisoning].

Objective: To investigate the related factors affecting the recovery of cholinesterase (ChE) activity in patients with acute chlorpyrifos poisoning. Methods: In February 2020, the clinical data of acute chlorpyrifos poisoning patients admitted in our hospital from January 2016 to December 2019 were retrospectively analyzed. The outcome variable was the time of ChE activity recovered to 50% lower limit of normal value, and multivariate linear regression analysis was performed to explore its influencing factors. Results: A total of 78 patients, 43 males and 35 females, with an average age (39.58±14.77) years were enrolled in this study. The average time of serum ChE activity recovered to 50% lower limit of normal value was (24.45±2.64) days. There was a correlation between hemoperfusion (r=-0.644) , atropine dosage (r=0.498) , chlorophosphorus dosage (r=0.432) and the time of serum ChE activity recovered to 50% lower limit of normal value, in which hemoperfusion was significantly negatively correlated with the time of serum ChE activity recovered to 50% lower limit of normal value (ß=-4.222, P<0.05) . Conclusion: The recovery of serum ChE activity in patients with acute chlorpyrifos poisoning is very slow. Hemoperfusion can quickly remove chlorpyrifos, its metabolites and inflammatory mediators in the blood, thus effectively promoting the recovery of ChE activity.

[Apoptosis during placentation].

Apoptosis is a normal physiological phenomenon. During the process of implantation, there are a large number of cells at the implantation site undergoing apoptosis, which has been suggested to play an important role in the regulation of endometrium decidulization and trophoblast invasion. Apoptosis mediated by Fas/FasL system may also be associated with maternal immunotolerance to the fetus. In this review, the common pathway of apoptosis and the regulation in the placenta are described.

[Experimental study on effect of lipid-lowering and treating coronary atherosclerosis with Chinese herbal prescription].

The Chinese herbal prescription was used in lipid-lowering, preventing and treating coronary atherosclerosis in this experiment. Through over 200 Leghorn chickens mould experiment and pathological sections were observed. The authors found that the effective rate of cholesterol-lowering was 88.23%, P less than 0.01. The authors also took 52 chickens with coronary atherosclerosis for medical treatment, after 40 days, 65.38% of chicken's artery pathological changes went down from higher than degree II to lower than degree II and 4 chickens' artery wall became normal. Before collagen pathologic changes occurred, fatty deposits on artery wall were changeable. After effective treatment it can take a turn for the better.

Hormonal regulation of plasminogen activator in rat and mouse seminiferous epithelium.

To elucidate the possible role of plasminogen activator (PA) in spermatogenesis and spermiation in mammals, we studied the hormonal regulation of PA secretion in cultured rat and mouse seminiferous tubules during defined stages of spermatogenesis. Results indicated that: (1) under basal conditions, segments of rat seminiferous tubules released primarily urokinase-type PA (uPA) at all stages of the cycle. The highest level of PA secretion occurred at stages VIIab, VIIcd and VIII. FSH, 8-bromo cyclic AMP and forskolin (FK) stimulated PA secretion, predominantly tissue-type PA (tPA). (2) In contrast, mouse seminiferous tubules secreted only tPA under basal conditions. In the presence of 50 microM MIX, seminiferous tubules at stages VII and VIII secreted higher levels of both types of PA than at the other stages. Both tPA and uPA secretion was enhanced by addition of FSH and FK to the organ culture media. (3) Segments of both rat and mouse seminiferous tubules at stages IX-XII in which the sperm residual bodies are absorbed into the Sertoli cells were also very sensitive to the addition of FSH to the organ culture. These results suggest that tPA in rat and mouse testes may play an essential role in the process of spermatogenesis and spermiation as well as in sperm residual body absorption.

A potential molecular mechanism for regulating pre-mRNA splicing of implantation-related genes through unique uterine expression of splicing factor SC35 in women and rhesus monkeys.

Splicing factor SC35 is an essential component of the spliceosome, the cellular apparatus that removes introns from pre-mRNA to provide alternatively spliced isoforms. Many proteins associated with development of uterine receptivity and embryo implantation are present as isoforms, the tissue-specific expression of which may be regulated through alternative splicing. SC35 was identified as being increased at implantation sites during early pregnancy in mice. However, the present study has demonstrated that SC35 is present in human and rhesus monkey endometrium, that the protein is increased during the secretory phase of the oestrous cycle compared with the proliferative phase in both these primates and that it is present in a distinct pattern within the nucleus of both epithelial and stromal cells, as well as in cells of the vasculature. Both the intensity of immunoreactive protein and the proportion of cells that stain for SC35 alter with the phase of the oestrous cycle. A very precise expression pattern of SC35 (both protein and mRNA) was seen during early placentation in rhesus monkeys. At implantation sites between day 24 and day 35 of early pregnancy, SC35 was expressed strongly in cytotrophoblasts within the trophoblastic shell, in syncytiotrophoblast at the periphery of the cell column and in both cytotrophoblast and syncytiotrophoblast in the floating villi. In the adjacent maternal decidua, expression of SC35 was weak. These results indicate a role for SC35 in preparation of a receptive uterus, in the provision of secreted proteins to support blastocyst development and in trophoblast invasion.

Cloning of novel temperature-related expressed sequence tags in rat testis during spermatogenesis.

Spermatogenesis needs the relatively cool environment of the scrotum in most mammals, it would be arrested when the testis was exposed to abdominal temperature. In this study, we have used a differential display PCR technique (DD-PCR) to screen temperature-related ESTs during spermatogenesis (TRS) in scrotal testes through a unilateral cryptorchid rat model after in situ analysis of testis cell DNA fragmentation. We reported here the cloning and sequencing of three such ESTs: TRS1, TRS3, and TRS4. Northern blot analysis confirmed that they were expressed specifically in scrotal testes. In situ hybridization showed that TRS1 was mainly expressed in the spermatocytes and the round spermatids in scrotal testis. Homology searches revealed that TRS1 and TRS3 were unknown cDNA sequences, and TRS4 was identical to a known EST whose function had not been reported. TRS1, TRS2, and TRS3 were first found to be temperature-related during spermatogenesis.