Experiments were carried on cultured neonatal myocardial cells of rat to study the effects of angiotensin Ⅰ(AngⅠ) and Ⅱ (AngⅡ) on the synthesis of DNA, RNA, protein and on the cardiac hypertrophy. It was shown that the incorporation of both ~3H-TdR and ~(14)C-uR increased over a set of time periods after addition of AngⅠ and AngⅡ to the medium. The mean protein content of the single myocardial cell was also enhanced, and the volume of myocardial cell was increased significantly after a continuous stimulation of AngⅠ and AngⅡ for 7 days. No stimulation effect was observed either in the synthesis of DNA, RNA, and protein or in the volume of myocardial cells after addition of AngⅠ together with the angiotensin converting enzyme inhibitor(ACEI, captopril). These results indicated that: (1). AngⅠ acts as a regulator by its indirect stimulation effect on the synthesis of DNA, RNA and protein of myocardial cells, since it must be changed into AngⅡ by the ACE present in myocardial cells. The ACE can be inhibited by the ACEI: (2) The hypertrophy of cultured neonatal myocardial cells may induced by a continuous stimulation of AngⅠ and AngⅡ.

Environmental Exposure ; adverse effects ; Hearing Loss ; etiology ; Humans ; Noise, Occupational ; adverse effects ; Occupational Diseases ; etiology ; Occupational Exposure ; adverse effects ; Risk Factors ; Smoking ; adverse effects ; Vibration ; adverse effects

Angiotensin III ; Humans

Cytokines ; metabolism ; Humans ; Leukocytes, Mononuclear ; immunology ; secretion ; Ubiquitin ; blood

Humans ; Noise, Occupational ; adverse effects ; Occupational Exposure ; standards

Formate dehydrogenase(FDH)coding gene was amplified from genomic DNA of Pichia pastoris by polymerase chain reaction, and the codon TAG(bases 649-651)was mutated to GAG using site-directed mutagenesis.The recombinant plasmid pET-FDH was con- structed by inserting the mutated DNA fragment into expression vector pET-22b(+),and transformed into E.coli BL21(DE3).FDH was expressed as a form of soluble prutein fused with 6?His tag at high level through IPTG induction.The amount of FDH was up to about 30% of the total cell protein.The cells-free crude extract was purified by one affinity chromatographic step,and resulting enzyme preparation revealed a specific activity of 6.45 U/mg.

Osteoblasts are the most important mechanoreceptive and osteogenic cells.The loss of bone in microgravity is mainly due to the dysfunction of osteoblasts.Research on osteoblast cytology under simulated weightlessness has made great progress in recent years.Current experiments are focusing on the changes in the cellular proliferation,differentiation,apoptosis, function and signal transduction in osteoblasts.This paper reviews the progress of the studies in this field.

Objective To explore the clinical characteristics and treatment strategies in preterm premature rupture of membranes.Methods The clinical data of 730 cases with preterm premature rupture of membranes from January 2005 to December 2009 in our hospital were retrospectively analyzed.The characteristics and perinatal outcomes were summarized.Results The incidence rate of preterm premature rupture of membranes was 2.68 %.The relative factors developing preterm premature rupture of membranes were in turn infection,high tension of uterus and abnormal fetal position.The perinatal complications were mainly preterm,fetal distress and RDS.The perinatal outcomes were directly related to the gestational weeks.Conclusion According to the relative factors leading to preterm premature rupture of membranes,adopting the relative clinical treatment,strengthening the gestational health and comprehensive treatment may reduce the morbidity of maternal and newborn and improve the prognosis of preterm neonates.

Objective To study the impact of sodium arsenite(NaAsO2) exposure on melanoma cells A375 (hereinafter referred to as the A375) and G361 (hereinafter referred to as the G361) pigment production and tyrosinase (TYR) activity and the differences of pigment metabolism capacity between the cell lines.Methods A375 and G361 cells were exposed to sodium arsenite at concentrations of 0.0(control),0.1 and 1.0 μmol/L for 72hours.Cell viability was measured by Alamar Blue assay.Melanin levels and TYR activity were measured at the same time.Results After exposure for 72 hours,the cells of 0.1 μmol/L dose groups of both of the two cell lines [A375:(103.32 + 1.26)％; G361:(104.10 + 1.76)％] showed a slightincrease of proliferation without significant differences compared with those of the control[A375:(100.00 ± 1.08)％; G361:(100.00 + 1.79)％,all P ＜ 0.05] ;while cell viability of the 1.0 μmol/L dose group of both of the two cell lines[A375:(75.32 ± 1.59)％; G361:(78.26 ± 2.10)％] were significantly lower than those of the control (all P ＜ 0.05).Melanin levels of G361 cell line [(7.19 ± 0.35),(7.34 ± 0.83),(8.19 ± 0.86)pg/cell] were significantly higher than that of A375[(4.35 ± 0.72),(4.54 ± 0.01),(4.60 + 0.59)pg/cell,all P ＜ 0.05] in all the three groups.TYR activity of G361 cell line [(54.13 ± 1.21),(54.56 ± 0.21),(56.25 ± 0.85)Bq] were also markedly higher than that of A375 cell[(42.00 ±0.21),(42.90 ± 0.54),(42.91 ± 0.01)Bq,all P ＜ 0.05] in all the three groups.The melanin levels and TYR activities of both of the two cells lines showed an increase tendency along with increased doses of arsenic exposure,but without significant differences when compared with those of the three groups (all P ＞ 0.05).Conclusions Arsenic related pigment disorder may be associated with increased melanin levels and TYR activities induced by arsenic exposure; individual difference of pigment metabolism may be associated with different basal melanin levels and TYR activity between different individuals.

Genomics ; Proteomics ; Toxicology