The effects of MC903, a novel 1,25-dihydroxyvitamin D3 [1,25(OH)2 D3] analogue, on proliferation and differentiation of a human megakaryoblastic leukemia cell line (HIMeg) were investigated. MC903 was found to inhibit cell proliferation and induce cell differentiation of HIMeg cells. Colony formation assay showed that MC903 (10-10 to 10-6mol/L) almost completely inhibited the colony-forming ability of HIMeg cells. Cell cycle analysis demonstrated that MC903 altered the cell cycle distribution; the fraction of cells in G0 + G1 increased while those in S and G2 + M decreased after treatment with MC903 for 4d. The effect of MC903 on proliferation and differentiation of HIMeg cells was in a dose- and time-dependent manner and was more active than that of 1, 25(OH)2, D3,. The results of the present study suggested that 1,25(OH)2 D3 as well as its novel analogue MC903 might play an important role in modulating the proliferation and differentiation of megakaryocytic lineage.

The cellular effects of glucocorticoids on proliferation and differentiation of a human inegakaryoblastic leukemia cell line (HIMeg) were studied in comparison with sex steroid hormones. In both liquid and methylcellulose culture systems, glucocorticoids suppressed the proliferate of HIMeg cells in a dose-dependent manner. In contrast, sex steroid hormones except progesterone had little effects on the proliferation of HIMeg cells. In liquid culture systems, morphological changes were not evident, and the percentage of cells with multilobular nuclei increased slightly from 2% to 8% after glucocorticoid treatment. Similarly, only 2% of HIMeg cells expressed glycoprotein Ⅱb/Ⅲa (GP Ⅱb/Ⅲa) antigen without hormone, whereas 30% of the cells expressed GP Ⅱb/Ⅲa with the addition of glucocorticoids. These data indicated that glucocorticoids could induce differentiation of HIMeg cells. To clarify the molecular mechanisms, glucocorticoid receptor (GR) expression was examind by Scatchard analysis, and it was found that there was a saturable, high affinity GR in HIMeg cells. Furthermore, the cellular effects of glucocorticoids on HIMeg cells could be reversed by RU486, a potent glucocorticoid antagonist. These observations suggest that the cellular effects of glucocorticoids on HIMeg cells were mediated by GR.

Objective To investigate the chemical constituents in the leaves of Dracaena cochinchinensis.Methods The compounds were separated with column chromatography and their chemical structures were identified by physicochemical and spectral method,respectively.Results Thirteen compounds were isolated from the plant. They were identified as isorhamnerin(Ⅰ),quercetin(Ⅱ),25(R)-spirostane-5-en-3?-ol(Ⅲ),gracillin(Ⅳ),25(R)-spirostane-5-en-3?,14?-diol(Ⅴ),25(R)-spirostane-5-en-3?,14?-diol-3-O-?-D-glucopyranoside(Ⅵ),25(R)-spirostane-5-en-3?,14?-diol-3-O-?-L-rhamnopyranosy(1→4)-?-D-glucopyranoside(Ⅶ),25(R)-spirostane-14?-hydroxy-4-en-3-one(Ⅷ),7?-hydroxysistosterol-3-O-?-D-glucopyranoside(Ⅸ),?-stigmasterol(Ⅹ),stigmasterol-3-O-?-D-glucopyranoside(Ⅺ),daucosterol (Ⅹ Ⅱ),and methyl ?D-glucopyranoside(Ⅹ Ⅲ).Conclusion Spirostane-type steroids are the major constituents in the leaves of D.cochinchinensis.Compounds Ⅰ-Ⅲ,Ⅴ,Ⅵ,Ⅷ,and Ⅸ are isolated from this plant for the first time.

Objective To summarize the experience on bronchiallavage to cure pulmonary atelectasis and pulmonary infection after thoracotomy.Methods 48 patients were selected and treated by bronchiallavage under monitoring,and antibiotics was used according to sputum culture and drug sensitive test.The out come was analyzed and evaluated.Results All patients of the pulmonary atelectasis were cured and those with pulmonary infection were controled.There was no serious complication.Conclusion Bronchiallavage is applied to treat pulmonary atelectasis and pulmonary infection after thoracotomy,the curative rate is significant.The appliance of antibiotics is guided by drug sensitivity.It is such a safe and feasible therapeutic tool that the bronchofibroscope is applied to cure pulmonary atelectasis and pulmonary infection after thoracotomy.

The activity of the negative regulator of cell cycle, P27, affects the normal process of cell cycle. As a type of cell cycle diseases, tumor is closely correlated with the activation of P27. It is shown that the level of P27 decreases in most kinds of tumors.By its influence on cell proliferation and apoptosis, P27 plays an important role in the occurrence and development of tumor. The activity of P27 is regulated by several pathways either at or after transcription, so various ideals which directly change the protein level of P27 or indirectly interfere the activities of elements in regulative pathways of P27 will provide many novel and efficient ways for therapies in tumors.

Thirty strains of seven Candida species from CICC(China Center of Industrial Culture Collection)were studied. The strains were differentiated by ITS1 region PCR-SSCP fingerprinting analysis and ITS2 region PCR-SSCP fingerprinting analysis. Results showed that both ITS1 region and ITS2 region were able to differentiate the seven species of Candida clearly. Contrasting the maps and effects on the identification of Candida species of ITS1 region with that of ITS2 region, result indicated that on the identification of Candida species the application of ITS2 region was better than ITS1 region.

The author reviewed some researches on teacher's work related stress in China and abroad. The present researches mainly focus on the sources of stress in teachers' work life. Some practices of work related stress in USA and Chinese special education field were discussed in the article. In the end, the author took a perspective on future research of teacher's work related stress in Chinese special education field.

BACKGROUND: The population of male and female adolescents in China accounts for 1/5. Adolescents have much psychological bewilderment,troublesome and even diseases on sexual issues.OBJECTIVE: To investigate the development status quo and the regulation of adolescents' sexual physiology, sexual psychology, sexual knowledge and sexual education.DESIGN: A cross-sectional survey by employing students of junior high school as subjects.SETTING: A clinic for adolescent of a tertiary hospital.PARTICIPANTS: Totally 960 students aged between 14 and 19 years old of three junior high schools in Dalian city were selected as subjects between November and December of 2001.METHODS: Self-complied questionnaire was used in the survey based on the sexual psychological education situation scale for junior and senior high school students. Classes were randomly selected for anonymous survey based on voluntary principle.Answers to sex-related questions and differences between male and female students.RESULTS: The average age of menarche in female students was 12.96years old and the average age of first emission in male students was 13.89years old, which were consistent with the results of similar national researches. The incidence and frequency of masturbation and sexual impulse was significantly higher in males than females. There were significant differences in sexual concept and the understanding of sexual knowledge between males and females. The desire to affiliate with the opposite sex was far more than the real occurrence.CONCLUSION: The understanding of sexual knowledge in adolescent is not satisfied. Students are also not satisfied with the sexual education provided by their schools. Hence, school sexual education for adolescents should be enhanced with the involvement of community.

One hundred kinds of excellent books on basic medicine were selected from Wanfang Data Knowledge Platform to develop a books-papers citation database.Their academic levels of the selected books were evaluated by PageRank algorithm.The chapters and sections of the books were divided into 4 parts according to their PageRank value and the distribution characteristics of their citation frequencies to study the PageRank and the top 20 cited chapters and sections of the books.The advantages and disadvantages of PageRank algorithm in book evaluation were described.

Objective To explore the expression profile of Wnt4 in rat kidney during renal development and its effect on renal development. Methods Rats with embryonic age of 18 days (E 18 d) , 20 days (E 20 d) as well as postnatal age of 0 day (P 0 d), 1 day (P 1 d), 3 days (P 3 d), 5 days (P 5 d) and 7 days (P 7 d) were selected. Expression levels of Wnt4 in rat kidney during renal development were quantified by immunohistochemistry and Western blot in all time points. Results Immuno?histochemistry analysis showed that during E 18 d to P 7 d, Wnt4 mainly expressed in proximal tubules, ureteric bud, comma shaped bodies and S shaped bodies of nephrogenic zone;the expression in the distal tubule was weak;the expression in renal corpuscle decreased with time;Western blot analysis showed that the expression of Wnt4 in rat kidney began to decrease from E 18 d and reached bottom at P 1 d then rise again until P 7 d when it dropped again. Conclusion During renal development, Wnt4 proteins were involved in the development of the nephrogenic zone through regulating canonical Wnt/β-catenin signaling pathway, and was involved in extension of proximal tubules by inducing the non canonical Wnt/PCP signaling pathway. Expression of Wnt4 protein in rat kidney was closely related to nephron formation and development of proximal tubules.