A comparison of the relationships between psychosocial factors,occupational strain,and work ability among 4 ethnic teacher groups in China

The present study compared the level of occupational strain and work ability among Han, Hui, Uygur, Hui, and Kazakh teachers, and explored ethnic differences based on the associations of psychosocial factors at work, occupational strain, and work ability. A cross-sectional survey was conducted among 2,941 teachers in primary and secondary schools in Xinjiang Province, China. Psychosocial factors, occupational strain, and work ability were measured using the Occupation Stress Inventory—Revised Edition (OSI-R) and Work Ability Index. Han and Hui teachers experienced reduced work ability compared with Uygur and Kazakh teachers, and this finding was caused, in part, by exposure to psychosocial factors at work. The vocational and psychological strains caused by these factors play an important role in reduced work ability among all ethnic teacher groups. The findings indicate the importance of taking action to reduce occupational strain for promoting teachers' work ability in multiethnic workplaces.     

Helicobacter pylori induces epithelial-mesenchymal transition in gastric carcinogenesis via the AKT/GSK3β signaling pathway

Helicobacter pylori (H. pylori) is a main risk factor for gastric cancer (GC). Epithelial-mesenchymal transition (EMT) is involved in the development and progression of H. pylori-associated GC. However, the exact molecular mechanism of this process remains unclear. The AKT/GSK3β signaling pathway has been demonstrated to promote EMT in several types of cancer. The present study investigated whether H. pylori infection induced EMT, and promoted the development and metastasis of cancer in the normal gastric mucosa, and whether this process was dependent on AKT activation. The expression levels of the EMT-associated proteins, including E-cadherin and N-cadherin, were determined in 165 gastric mucosal samples of different disease stages by immunohistochemical analysis. The expression levels of E-cadherin, N-cadherin, AKT, phosphorylated (p-)AKT (Ser473), GSK3β and p-GSK3β (Ser9) were further determined in H. pylori-infected Mongolian gerbil gastric tissues and cells co-cultured with H. pylori by immunohistochemical analysis and western blotting. The results indicated that the expression levels of the epithelial marker E-cadherin were decreased, whereas the expression levels of the mesenchymal marker N-cadherin were increased during gastric carcinogenesis. Their expression levels were associated with H. pylori infection. Furthermore, H. pylori infection resulted in downregulation of E-cadherin expression and upregulation of N-cadherin expression in Mongolian gerbils and GES-1 cells. In addition, an investigation of the associated mechanism of action revealed that p-AKT (Ser473) and p-GSK3β (Ser9) were activated in GES-1 cells following co-culture with H. pylori. Furthermore, following pretreatment of the cells with the AKT inhibitor VIII, the expression levels of E-cadherin, N-cadherin, p-AKT and p-GSK3β did not show significant differences between GES-1 cells that were co-cultured with or without H. pylori. The levels of p-AKT and p-GSK3β were increased in H. pylori-infected Mongolian gerbils. In conclusion, the present study demonstrated that H. pylori infection activated AKT and resulted in the phosphorylation and inactivation of GSK3β, which in turn promoted early stage EMT. These effects were AKT-dependent. This mechanism may serve as a prerequisite for GC development.     

棕榈油对成人血脂和血小板功能的影响

报道了棕榈油（ＰＡ），花生油（ＰＥ）对血清总胆固醇水平（ＴＣ）在５．５～７．０ｍｍｏｌ／Ｌ的受试者血脂和血小板功能的影响。５１名受试者（男３１人，女２０人，年龄３０～６６岁之间）分为两组，一组男１５人，女１１人，称ＰＥ组；另一组男１６人女９人，称ＰＡ组，预备期３周，膳食以当地日常食用的花生油烹调，实验期６周。ＰＡ组受试者食用以棕榈油烹调的实验膳；ＰＥ组受试者仍食花生油烹调的膳食。脂肪约占膳食能量的３０％，其中６０％～６５％来自实验油。实验结果表明：与起始值相比，６周末ＰＡ组受试者血清ＴＣ，低密度脂蛋白胆固醇（ＬＤＬ－Ｃ）和总胆固醇与高密度脂蛋白胆固醇比值（ＴＣ／ＨＤＬ－Ｃ）显著下降，血浆血栓素Ｂ２（ＴＸＢ２）／６－酮前列环素Ｆ１α、（６－ｋｅｔｏ－ＰＧＦ１α）比值显著下降，全血血小板聚集率未见显著变化。ＰＥ组受试者的血脂、血浆ＴＸＢ２、６－ｋｅｔｏ－ＰＧＦ１α及全血血小板聚集率等指标均未出现显著变化。提示，棕榈油作为我国居民家庭烹调用油并不会增加发生心血管疾病的危险。     

儿童难治性肾病综合征的探讨95例临床分析

本文对95例肾病综合征进行分析,探讨了性别、年龄、发病迁延时间、浮肿、蛋白尿、血尿、血压、尿素氮、血浆蛋白、血浆胆固醇、免疫球蛋白、补体C_3与激素反应及分型的关系。认为下列综合分析可做为判定难治性肾病综合征的参考。难治性肾病多分布在7岁以上,激素治疗4～8周血浆蛋白尚未恢复,尿镜检反复出现红细胞及颗粒管型,血清r—球蛋白不低,而补体C_3降低,提示难治性肾病。各种感染常常是造成肾病综合心难以控制,甚至死亡的重要因素。     

Response of lumbar paraspinal muscles spindles is greater to spinal manipulative loading compared with slower loading under length control.

BACKGROUND CONTEXT: Spinal manipulation (SM) is a form of manual therapy used clinically to treat patients with low back and neck pain. The most common form of this maneuver is characterized as a high-velocity (duration <150 ms), low-amplitude (segmental translation <2 mm, rotation <4 degrees , and applied force 220-889 N) impulse thrust (high-velocity, low-amplitude spinal manipulation [HVLA-SM]). Clinical skill in applying an HVLA-SM lies in the practitioner's ability to control the duration and magnitude of the load (ie, the rate of loading), the direction in which the load is applied, and the contact point at which the load is applied. Control over its mechanical delivery is presumably related to its clinical effects. Biomechanical changes evoked by an HVLA-SM are thought to have physiological consequences caused, at least in part, by changes in sensory signaling from paraspinal tissues. PURPOSE: If activation of afferent pathways does contribute to the effects of an HVLA-SM, it seems reasonable to anticipate that neural discharge might increase or decrease in a nonlinear fashion as the thrust duration approaches a threshold value. We hypothesized that the relationship between the duration of an impulsive thrust to a vertebra and paraspinal muscle spindle discharge would be nonlinear with an inflection near the duration of an HVLA-SM delivered clinically (<150 ms). In addition, we anticipated that muscle spindle discharge would be more sensitive to larger amplitude thrusts. STUDY DESIGN/SETTING: A neurophysiological study of spinal manipulation using the lumbar spine of a feline model. METHODS: Impulse thrusts (duration: 12.5, 25, 50, 100, 200, and 400 ms; amplitude 1 or 2 mm posterior to anterior) were applied to the spinous process of the L6 vertebra of deeply anesthetized cats while recording single unit activity from dorsal root filaments of muscle spindle afferents innervating the lumbar paraspinal muscles. A feedback motor was used in displacement control mode to deliver the impulse thrusts. The motor's drive arm was securely attached to the L6 spinous process via a forceps. RESULTS: As thrust duration became shorter, the discharge of the lumbar paraspinal muscle spindles increased in a curvilinear fashion. A concave-up inflection occurred near the 100-ms duration eliciting both a higher frequency discharge compared with the longer durations and a substantially faster rate of change as thrust duration was shortened. This pattern was evident in paraspinal afferents with receptive fields both close and far from the midline. Paradoxically, spindle afferents were almost twice as sensitive to the 1-mm compared with the 2-mm amplitude thrust (6.2 vs. 3.3 spikes/s/mm/s). This latter finding may be related to the small versus large signal range properties of muscle spindles. CONCLUSIONS: The results indicate that the duration and amplitude of a spinal manipulation elicit a pattern of discharge from paraspinal muscle spindles different from slower mechanical inputs. Clinically, these parameters may be important determinants of an HVLA-SM's therapeutic benefit.     

Stimulation of Alpha-Adrenoceptors Facilitates the Release of Growth Hormone-Releasing Hormone from Rat Hypothalamus in vitro

While extensive evidence suggests that adrenoceptors play an important role in the control of growth hormone in the rat, there are few studies involving the direct measurement of growth hormone-releasing hormone (GHRH). We have therefore developed a radioimmunoassay for rat GHRH, and used it to investigate the modulation of GHRH release by noradrenaline from incubated rat hypothalamus in vitro. The GHRH radioimmunoassay had no significant cross-reactivity with other hypothalamic or GHRH-related peptides, and was sensitive to 4 pg/tube; intra- and interassay coefficients of variation were 6% and 12% respectively. Single incubated rat hypothalami produced a stable and readily measurable output of GHRH in successive 20 min incubations after an initial 60 min preincubation; the release of GHRH was increased in the presence of 56 mM KCI, but did not respond to KCI-depolarization when calcium was excluded from the medium. Stimulated GHRH release was identical to synthetic rat GHRH(1–43) on high-performance liquid chromatography and Sephadex G-75 chromatography.
Noradrenaline stimulated GHRH secretion in a dose-dependent manner in the concentration range 10⁻¹⁰— 10⁻⁶M, with a plateau in response at 10⁻⁷M. Stimulation with noradrenaline 10⁻⁷M was blocked by idazoxan 10⁻⁵M and attenuated by thymoxamine 10⁻⁵M, but was unaffected by timolol 10⁻⁵M. Both the α₂-adrenoceptor agonist guanfacine, and the α₁-adrenoceptor agonist methoxamine, specifically stimulated GHRH secretion.
It is concluded that noradrenaline stimulates the release of GHRH at both α₁ and α₂-adrenoceptors.