BACKGROUND: Under specially physical environment, for example weightlessness, metabolism of bone tissue may have remarkable changes; however, osteoblast is a core of bone metabolism and bone formation, so it is very sensitive to changes of gravity environment.OBJECTIVE: To observe the effects of simulated weightlessness on bone marrow stromal cell count and osteogentic capacity of weight bearing bone in rats so as to reveal the mechanism of bone loss.DESIGN : Randomized pairing and controlled study.SETTING: College of Aerospace Medicine and Department of Pathology of Stomatology College, the Fourth Military Medical University of Chinese PLA.MATERIALS: A total of 20 adult healthy male SD rats were selected in this study. At the beginning of experiment, rats based on their body mass were randomly divided into control group and suspension group with 10 in each group. Alkaline phosphatase kit was provided by Beijing Zhongsheng Bioengineering High-technological Company.METHODS: The experiment was carried out in the Department of Pathology, Collage of Stomatology, the Fourth Military Medical University of Chinese PLA from November 1999 to July 2000. Rats were randomly divided into tail suspension group and control group with 10 in each group. Rats in the tail suspension group were given tail suspension for 28 days. Their heads maintained 30° low position, and their hindlimbs freely suspended and were not given weight loading. While, rats in the control group were fed normally. At the end of experiment, bone marrow stromal cells were obtained from femur for primary and transferring cultures.MAIN OUTCOME MEASURES: Cell counting and methylthianolyldiphenyl-tetrazolium bromide (MTT) assay were used to draw growth curve of cells in primary and transferring cultures and to measure activity of alkaline phosphatase and forming quantity of mineralized nodules in vitro.RESULTS : ① Activity of alkaline phosphatase: Activity of alkaline phosphatase of cells in the primary and transferring cultures in the suspension group was lower than that in the control group, and there was significant difference between them (P＜0.05). ② Forming quantity of mineralized nodules: Forming quantity of mineralized nodules in the suspension group was less than that in the control group, and there was significant difference between them (P＜0.05). ③ Cell growth: Growth curve of femoral stromal cells in primary and transferring culture manifested as S. Doubling time of cells in the suspension group was similar to that in the control group. ④ Amount of bone marrow stromal cells in femur: Amount of bone marrow stromal cells in primary culture in the suspension group was decreased as 50% as that in the control group (P＜0.05).CONCLUSION: Under simulated weightlessness, amount of bone marrow stromal cells decreases obviously; in addition, amount of osteoblast also decreases in weight bearing bone of hindlimbs and osteogentic capacity in vitro decreases simultaneously.

Objective To explore effects of ephedrine on epinephrine (EPI) and estradiol( E2)concentration in blood, histological structures and activity of superoxide dismutase (SOD) and maleic dialdehyde (MDA) content in the ovary of female mice.Methods Pregnant female mice in the experimental group were treated with ephedrine (2g/L,4g/L, 6g/L), and the mice in the control group were treated with saline by intraperitoneal injection .Using ELISA method to detect concentration changes of EPI and E 2 in plasma, the changes in the enzymatic activity of SOD and MDA content were analyzed by colorimetry .The ovarian weight was measured , histological structures in ovary were observed by microscopy and the number of ovarian follicles were counted .Results EPI concentration in plasma of female mice increased , and the E2 concentration decreased dose-dependently in the experimental group .The activities of SOD were lower , and MDA content significantly increased compared to the control .The ovary weight of experimental groups was lower than the control group.The numbers of primary follicle , secondary follicle and atretic follicle increased and corpus luteum decreased in the experimental groups .There were pyknotic ovarian tissues , including oocyte ateophy , degradation granulose cells , and karyopyknotic granulose lutein cells in the experimental groups .Conclusion Ephedrine has a great effect on the ovarian histological structure and ovarian function of female mice , which may be correlated with the low activities of SOD .

Objective:To investigate the clinical features and influencing factors of long-term prognosis of tuberculous meningitis(TBM), and to provide a recommendation for treatment and early intervention of TBM.Methods:Clinical data of TBM patients were retrospectively collected at Peking Union Medical College Hospital from January 2014 to December 2021. Patients who were followed-up more than one year were divided into two groups according to modified Rankin Scale (mRS). Risk factors associated with long-term prognosis were analyze by conditional logistic stepwise regression.Results:A total of 60 subjects were enrolled including 33 (55%) males and 27 (45%) females with age 15-79 (44.5±19.8) years. There were 30 cases (50%) complicated with encephalitis, 21 cases (35%) with miliary tuberculosis. The diagnosis was microbiologically confirmed in 22 patients (36.7%), including 5 cases (22.7%, 5/22) by acid-fast staining, 8 cases (36.4%, 8/22) by Mycobacterium tuberculosis (MTB) culture, and 20 cases (90.9%, 20/22) by molecular biology. The median follow-up period was 52(43, 66 ) months in 55 cases surviving more than one year. Among them, 40 cases (72.7%) were in favorable group (mRS 0-2) and 15 cases (27.3%) were in unfavorable group (mRS 3-6) with poor prognosis. The mortality rate was 20% (11/55). Elderly ( OR=1.06, P=0.048 ) , hyponatremia( OR=0.81, P=0.020), high protein level in cerebrospinal fluid (CSF) ( OR=3.32, P=0.033), cerebral infarction( OR=10.50, P=0.040) and hydrocephalus( OR=8.51, P=0.049) were associated with poor prognosis in TBM patients. Conclusions:The mortality rate is high in patients with TBM. Molecular biology tests improves the sensitivity and shorten the diagnosis time of TBM. Elderly, hyponatremia, high protein level in CSF, cerebral infarction and hydrocephalus are independent risk factors of long-term survival in TBM patients.