[Investigation on accidents happened during 1966-2003 in one petrochemical enterprise].
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Accidents, Occupational↗
Biomedical subjects
Sheng Wang
Publications and source records attributed to Sheng Wang.
Apoptotic and mitogenic stimuli inactivate Rb by differential utilization of p38 and cyclin-dependent kinases.
Inactivation of the retinoblastoma (Rb) tumor suppressor protein is essential for the G1/S transition during mammalian cell cycle progression. Although Rb is inactivated by phosphorylation by cyclins D and E and their associated kinases during cell cycle progression, we find that Rb is inactivated upon apoptotic stimulation by Fas through the mediation of p38 kinase, independent of cyclins and cyclin-dependent kinases (cdks). Inactivation by p38 kinase coincided with increased phosphorylation of Rb leading to dissociation of E2F and increased transcriptional activity; such p38-mediated changes in Rb function occurred only during Fas stimulation but not mitogenic progression. p38 kinase targets Rb preferentially and had minimal effects on p107 and had no effect on p130 function. We also find that phosphorylation site mutants of Rb (PSM7LP and PSM9-Rb) that cannot be inactivated by cdks can be targeted by Fas and p38 kinase, suggesting that Rb inactivation by these kinases is biochemically and functionally distinct. It appears that Rb inactivation is achieved by different kinase cascades in response to mitogenic and apoptotic signals.
Apoptosis↗
Exocyst complex subunit sec8 binds to postsynaptic density protein-95 (PSD-95): a novel interaction regulated by cypin (cytosolic PSD-95 interactor).
The PDZ domains of postsynaptic density (PSD) protein-95 play a role in the localization of PSD-95 and binding partners to neuronal synapses. The identification of binding partners to these PDZ domains can help us in understanding how signalling complexes are assembled. We observed that one of the subunits in the sec6/8 or exocyst complex, sec8, contains a C-terminal consensus sequence for PDZ binding. Sec8 binds to PDZ1-2 of PSD-95, and this binding can be competed with a peptide that binds to PDZ1 and PDZ2 in the peptide-binding site. In addition, binding of sec8 is dependent on its C-terminal-binding sequence namely Thr-Thr-Val (TTV). Immunoblotting of rat tissue extracts shows that sec8 and PSD-95 are enriched in the same brain regions, and sec8 and PSD-95 have the same subcellular distribution in pheochromocytoma cells, suggesting that these proteins may interact in vivo. Immunoprecipitation studies of sec8 and PSD-95 in brain provide further evidence of a sec8 and PSD-95 interaction. Furthermore, the cytosolic PSD-95 interactor competes with sec8 for interaction with PSD-95. Taken together, our results suggest that the cytosolic PSD-95 interactor may function to regulate the ability of sec8 to bind to PSD-95.
Amino Acid Sequence↗
Effects of alpha-tocopherol on noise-induced hearing loss in guinea pigs.
Preventing noise-induced hearing loss (NIHL) by antioxidants is based on the hypothesis that generation of reactive oxygen species is one of the causes of NIHL. alpha-Tocopherol is a naturally occurring antioxidant with no noticeable side effects. In this study, we attempted to protect guinea pigs from developing NIHL by administering alpha-tocopherol. Pigmented male guinea pigs were exposed to a noise (4 kHz octave band, 100 dB SPL), 8 h/day for 3 days consecutively. alpha-Tocopherol (10 mg/kg or 50 mg/kg daily) was given by intraperitoneal injection from 3 days before through 3 days after the noise exposure. Auditory evoked brainstem response (ABR) thresholds at 2, 4 and 8 kHz were recorded prior to the experiment, immediately post-noise, 2 and 8 days post-noise. On day 8 post-noise, after the ABR recording, guinea pigs were decapitated and the cochleae were removed for cochlear surface preparations and scanning electron microscope (SEM) study. ABR threshold shifts of groups receiving alpha-tocopherol were significantly smaller than those of groups not receiving alpha-tocopherol at all frequencies and all time points tested except that of group 3 at 8 kHz 8 days post-noise. No hair cell loss was seen on the surface preparations, but stereocilia loss was found by SEM study. The noise-induced stereocilia loss was significantly decreased by alpha-tocopherol. These results indicate that alpha-tocopherol can attenuate the noise-induced cochlear damage. Further investigations on the preventive effect of alpha-tocopherol on NIHL in noise-exposed workers are necessary.
Animals↗
Crystal structure of Escherichia coli sigmaE with the cytoplasmic domain of its anti-sigma RseA.
The sigma factors are the key regulators of bacterial transcription. ECF (extracytoplasmic function) sigma's are the largest and most divergent group of sigma(70) family members. ECF sigma's are normally sequestered in an inactive complex by their specific anti-sigma factor, which often spans the inner membrane. Here, we determined the 2 A resolution crystal structure of the Escherichia coli ECF sigma factor sigma(E) in an inhibitory complex with the cytoplasmic domain of its anti-sigma, RseA. Despite extensive sequence variability, the two major domains of sigma(E) are virtually identical in structure to the corresponding domains of other sigma(70) family members. In combination with a model of the sigma(E) holoenzyme and biochemical data, the structure reveals that RseA functions by sterically occluding the two primary binding determinants on sigma(E) for core RNA polymerase.
Binding Sites↗
Immunological characterization of exocyst complex subunits in cell differentiation.
We have generated monoclonal antibodies (MAbs) against three proteins sec6, sec15, and exo84. These proteins have been shown to be components of the exocyst complex, a macromolecule required for many biological processes such as kidney epithelial formation and neuronal development. These antibodies can detect the three proteins by enzyme-linked immunoadsorbent assay (ELISA), Western blotting, immunofluorescence microscopy, and immunoprecipitation. Using these antibodies, we found that the three proteins have similar subcellular localization which changes upon cell differentiation. These three proteins also co-immunoprecipitate with each other. These results suggest that at least three exocyst subunits associate with each other in vivo and redistribute in response to cell differentiation. In the future, these antibodies should be useful in the cell biological and functional analysis of the exocyst complex under physiological and pathological conditions.
Animals↗
Enhancement of DNA vaccine potency against herpes simplex virus 1 by co-administration of an interleukin-18 expression plasmid as a genetic adjuvant.
In this study, the immune-modulatory and vaccine effects of using an interleukin (IL)-18 expression plasmid as a genetic adjuvant to enhance DNA vaccine-induced immune responses were investigated in a mouse herpes simplex virus 1 (HSV-1) challenge model. BALB/c mice were immunized by three intramuscular inoculations of HSV-1 glycoprotein D (gD) DNA vaccine alone or in combination with a plasmid expressing mature IL-18 peptide. Both the serum IgG2a/IgG1 ratio and T helper 1-type (Th1) cytokines [IL-2 and interferon (IFN)-gamma] were increased significantly by the co-injection of the IL-18 plasmid compared with the injection of gD DNA alone. However, the production of IL-10 was inhibited by IL-18 plasmid co-injection. Furthermore, IL-18 plasmid co-injection efficiently enhanced antigen-specific lymphocyte proliferation and the delayed-type hypersensitivity response. When mice were challenged with HSV-1 at the cornea, co-injection of IL-18 plasmid with gD DNA vaccine showed significantly better protection, manifested as lower corneal lesion scores and faster recovery. These experiments indicate that co-injection of an IL-18 plasmid with gD DNA vaccine efficiently induces Th1-dominant immune responses and improves the protective effect against HSV-1 infection.
Adjuvants, Immunologic↗
[The involvement of endocrine disrupting chemicals in spermatogenic cell apoptosis].
Elimination of spermatogenic cells via apoptosis occurs spontaneously under normal physiologic conditions and is often aggravated after chemical-induced testicular impairment. A great amount of pollutants is released into the environment by modern industry, and many of these substances have been confirmed possessing reproductive toxicity, which can affect the reproduction and development of organism. These chemicals have been categorized to endocrine disrupting chemicals(EDCs). Studying spermatogenic cell apoptosis induced by EDCs will enrich and expand the pathway to identify EDCs, and will put forward new expounding of its mechanism. It has important meaning in the field of reproduction toxicology and male fertility.
Apoptosis↗
[Alteration of neurobehavioral and autonomic nervous function in aluminum electrolytic workers].
In order to explore the impairment of Aluminum on the neurobehavioral, autonomic nervous function. Neurobehavioral test battery (NCTB) recommended by WHO and autonomic nervous system (ANS) function test recommended by Ewing DJ were conducted in 32 Al electrolytic workers and 34 controls. Results showed that the scores of confusion-bewilderment and tension-anxious in Al exposed workers were higher than that of control group, while the scores of POMSA, POMSD, POMSF and POMSV in Al-exposed group had no obvious change. The scores of DSY, PA and PAC were lower than that of control group. The scores of DSPF, DDSPB, DSP, SANN, SANP and BVR had no significant alteration. R-R interval variability of maximin ratio of immediate standing up, which reflects parasympathetic nervous modification ability in aluminum electrolytic workers, was lower than that of the control group. This implied that Al exposure had adverse impact on workers' mood state, neurobehavioral and parasympathetic nervous function.
Adult↗
A survey on injury incidence in school children in Shantou City, China.
OBJECTIVES: To study incidence characteristics and causes of injury, and its medical consequences in school children of China. METHODS: A total of 2,553 school children aged 7-16 years were recruited from Shantou City in Gunagdong by cluster sampling method, and were investigated with questionnaires on cases of injuries occurred among them from October 1, 1996 to September 30, 1997. RESULTS: Injuries tended to increase with children's age, with an overall incidence rate of 37.96%, higher in boys than in girls (P<0.05); and 38.1% of children had more than two episodes of injury during this period. Falls took leading place of injury incidence both in boys and girls and in all age groups. Most injuries occurred when they were playing, sporting, riding and walking at home or in school. Self-inflicted injury ranked the first place of all injuries, followed by hurt caused by others (classmates, sibling or others). Moderate and serious injuries accounted for 8% of the total with a disability rate of 121.4/100,000. CONCLUSIONS: Currently, injury has become one of the serious public health problems in China. For the improvement of children survival, it is crucial to reduce their injury to strengthen research on child safety and to implement safety-promotion programs.
Accidental Falls↗
[Application of capture-recapture method on injury control].
OBJECTIVE: To explore relationships among several capture-recapture methods to be used in injury studies. METHODS: Comparing the method on the estimation number of missed cases with supergeometric distribution and proportional methods and study the relationship between the three methods. RESULTS: Results from estimation method for number of missed cases and supergeometric distribution were identical while the formula of estimation method for number of missed cases could be induced from one of supergeometric distribution formula. The distribution of injured population did not belong to the negative binomial distribution. The estimation range was not the same between proportional method and supergeometric distribution. CONCLUSIONS: Either supergeometric distribution or estimation method for number of missed cases could be chosen, but the former was simple in calculation. Considering the estimating range was not the same between supergeometric distribution and proportional method, conditions for application must be considered during implementation.
Epidemiologic Methods↗
[Study on the characteristics of incidence and death among inpatients with injury in Guangdong province from 1997 to 2001].
OBJECTIVE: To study the trends in the distribution and change of total injuries were explored during 1997 - 2001. To provide scientific bases in setting up priorities and improving safety standards. METHODS: To collect and analyze the data about all inpatients of injuries attending hospital and hospitalization at 322 hospitals between 1997 and 2001 in Guangdong, China. The main outcome measures included external causes, medical consequences, mortality, length of hospital stay, and costs. RESULTS: Rate of all-injury hospitalization increased yearly, from 1997 to 2001. The ratio of inpatient case-fatality declined over a 5-year period, with the total case-fatality rate of 1.64%. The inpatients were mainly caused by motor vehicle accident, unintentional falls, punctured and cut by machine, hurt by others and homicide. The constituent ratio of deaths among patients caused by motor vehicle accident was accounted for 56.13% among the total deaths, which occupied the first place. Despite the fact that the mean length of stay declined by 3.58% for the hospitalized patients over a 5 year period, and by 2.20% for the healed patients, costs increased by 3.89% for the hospitalized patients and by 4.71% for the healed patients with an average costs per patient per day increased by 7.33%. CONCLUSION: The all-injury hospitalization rate had a trend of increase from 1997 to 2001, but the ratio of inpatient case-fatality declined over the 5-year period, and the direct medical cost also had a trend of increase.
China↗
[Effects of noise on antioxidant enzymes of cochlea in guinea pigs].
OBJECTIVE: To investigate the effect of noise on the antioxidant enzymes of cochleae. METHODS: 16 male pigmented guinea pigs (250 - 300 g) were randomly divided into 2 groups, control group and noise group. Each group had 8 animals. The animals in noise group were performed auditory evoked brainstem responses (ABR) recording before and after exposure to a continuous noise (4 kHz, octave band, 100 dB, SPL) 8 h/d for 3 consecutive days. Immediately at the end of the third day's noise exposure after ABR recording, guinea pigs were decapitated. Both the right and the left cochlea with the bony capsule removed were homogenized, and the supernatants were prepared for assays. Reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were measured. RESULTS: ROS level of the noise group [(281.2 +/- 3.5) U/mg pro] was significantly higher than that of the control group [(273.0 +/- 3.2) U/mg pro, P < 0.05] and SOD, CAT and GSH-Px activities of the noise group [(206.5 +/- 5.1) NU/mg pro, (47.0 +/- 9.0) U/g pro, (14.1 +/- 2.5) U/mg pro respectively] were significantly lower than that of the control group [(221.8 +/- 4.8) NU/mg pro, (60.8 +/- 9.9) U/g pro, (21.1 +/- 3.1) U/mg pro respectively, P < 0.05]. CONCLUSION: Noise may damage the defensive system of antioxidant enzymes in cochlea.
Animals↗
[A study of the effect of occupational stress on glucocorticoid receptor and immune function in dispatchers].
OBJECTIVE: To study the effect of chronic occupational stress on the glucocorticoid receptor (GR) and immune function. METHODS: A cross-sectional study was conducted in 112 railway station dispatchers. Perceived job stress was assessed by means of the Chinese version of the Job Content Questionnaire. The subjects were divided into high, medium and low strain groups according to the job strain score of the questionnaire. The number of GR, percentage of T lymphocyte subpopulations, concentrations of cortisol and interleukin 2 (IL-2) in blood were measured. RESULTS: The concentrations of serum cortisol in high and medium strain groups [(295.43 +/- 79.06) and (274.34 +/- 70.08) ng/ml respectively] were higher than that in low strain group [(181.01 +/- 53.41) ng/ml, P < 0.05]. GR binding capacity in both groups (4,330.0 +/- 1,001.0, 3,971.6 +/- 966.8 specific binding/cell respectively) were smaller than that in low strain group (5,141.3 +/- 1,068.5 specific binding/cell, P < 0.05). The percentage of CD(3) T lymphocyte in high strain group was higher than that in low strain group [(50.21 +/- 10.30)% vs (56.87 +/- 15.36)%, P < 0.05], and CD(4) T lymphocyte in high and medium strain groups were significantly smaller than that in low strain group [(23.27 +/- 10.01)%, (27.06 +/- 7.47)% vs (33.31 +/- 7.77)%, P < 0.05]. In contrast, the percentage of CD(8) T lymphocytes in high and medium strain groups were significantly higher than that in low strain group [(28.16 +/- 6.47)%, (25.54 +/- 6.70)% vs (21.91 +/- 5.93)%, P < 0.05]. The levels of serum IL-2 in high and medium groups were smaller than that in low strain group [(0.77 +/- 0.05), (0.80 +/- 0.07) vs (1.05 +/- 0.12) ng/ml, P < 0.05]. Correlation analysis showed that serum cortisol level was negatively correlated with CD(8) percentage (r = -0.612, P < 0.01). CONCLUSION: Chronic occupational stress may induce rise of glucocorticoid, down-regulation of GR and inhibition on immune function.
CD4-CD8 Ratio↗
Prohibitin co-localizes with Rb in the nucleus and recruits N-CoR and HDAC1 for transcriptional repression.
The potential tumor suppressor protein prohibitin can prevent cell proliferation and this required its binding to the Rb protein. Prohibitin could repress the transcriptional activity of E2F family members and this required a part of the marked box region of E2F. The sub-cellular localization of prohibitin has been variously attributed to the mitochondria as well as the inner cell membrane. Here we show that a subset of prohibitin molecules are present in the nucleus where it co-localizes with the Rb protein. Deletion of a putative amino-terminal membrane-docking domain of prohibitin had no effect on its ability to suppress cell proliferation or inhibit E2F activity. Our experiments show that a 53 amino-acid stretch of E2F1 is sufficient for being targeted by prohibitin; fusion of this region to GAL4-VP16 construct could make it susceptible to prohibitin-mediated, but not Rb-mediated repression. Prohibitin, like Rb, could repress transcription from SV40 and major late promoters when recruited directly to DNA. Prohibitin mediated transcriptional repression required histone-deacetylase activity, but unlike Rb, additional co-repressors like N-CoR are also involved. Repression by prohibitin correlates with histone deacetylation on promoters and this was reversed by IgM stimulation of cells; IgM did not affect Rb-mediated repression or deacetylation of the promoters. Prohibitin thus appears to repress E2F-mediated transcription utilizing different molecular mediators and facilitate channeling of specific signaling pathways to the cell cycle machinery.
Base Sequence↗
Cytoprotective role of Ca2+- activated K+ channels in the cardiac inner mitochondrial membrane.
Ion channels on the mitochondrial inner membrane influence cell function in specific ways that can be detrimental or beneficial to cell survival. At least one type of potassium (K+) channel, the mitochondrial adenosine triphosphate-sensitive K+ channel (mitoKATP), is an important effector of protection against necrotic and apoptotic cell injury after ischemia. Here another channel with properties similar to the surface membrane calcium-activated K+ channel was found on the mitochondrial inner membrane (mitoKCa) of guinea pig ventricular cells. MitoKCa significantly contributed to mitochondrial K+ uptake of the myocyte, and an opener of mitoKCa protected hearts against infarction.
Adenosine Triphosphate↗
[Phytoestrogen genistein inhibits carotid sinus baroreflex in anesthetized male rats].
The purpose of this study was to determine the effect of phytoestrogen genistein (GST) on carotid sinus baroreflex in 30 anesthetized male rats by perfusing the isolated carotid sinus in vivo. The results obtained are as follows. (1) By perfusion with GST (50 micromol/L), the functional curve of baroreflex was shifted to the right and upward, with a peak slope (PS) decrease from 0.36+/-0.01 to 0.23+/-0.01 (P<0.001) and a reflex decrease (RD) in mean arterial pressure from 39.75+/-1.58 to 27.00+/-0.60 mmHg (P<0.001), while the threshold pressure (TP) and saturation pressure (SP) were significantly increased from 65.63+/-2.1 to 82.05+/-1.95 mmHg (P<0.001) and from 192.23+/-3.90 to 215.76+/-3.75 mmHg (P<0.001), respectively. Among the functional parameters of carotid baroreflex, the changes in RD, PS and TP were dose-dependent. (2) Pretreatment with Bay K 8644 (500 nmol/L), an agonist of calcium channels, could completely abolish the inhibitory effect of GST on carotid baroreflex. (3) Preperfusion with an inhibitor of NO synthase, L-NAME (100 micromol/L), did not affect the inhibitory effect of GST. It is proposed that the inhibitory action of GST on carotid baroreflex may be mediated by the inhibition of Ca(2+) channel of vascular smooth muscle, but not by NO release from endothelium.
3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
Differential regulation of Rb family proteins and prohibitin during camptothecin-induced apoptosis.
Prohibitin, a potential tumor suppressor, is known to induce growth suppression and repress E2F-mediated transcription. These growth regulatory functions of prohibitin require a physical interaction with the Rb protein. We now find that prohibitin protects cells from apoptosis mediated by camptothecin, a topoisomerase I inhibitor. Camptothecin treatment of Ramos B cells leads to the degradation of Rb protein and phosphorylation of its family members, p107 and p130. This correlates with an increase in the levels of cyclin E as well as the kinase activity associated with it. Inactivation of Rb leads to the dissociation and release of free E2F. We find also that E2F activity is induced upon camptothecin treatment, but this increase is absent in prohibitin overexpressing cells. It thus appears that prohibitin may be inhibiting apoptosis by downregulating E2F activity when Rb family members are inactive.
Apoptosis↗