BACKGROUND: Embryonic stem cells (ESCs), the seed cells of all mature cells in vivo, are useful tools for nerve transplantation and developmental gene function research. Notch1 signaling pathway is the key pathway to control the ordered neural development and differentiation of many kinds of neural cells, however, there is no report on the dynamic expression of Notch1 signal during the ESC differentiation to date. OBJECTIVE: To investigate the expression of Notch1 protein, transmembrane signal transduction molecule, during directional differentiation of embryonic stem cells into neural cells. DESIGN, TIME AND SETTING: Cell research was carried out between October 2003 and October 2004 at Zhongshan Ophthalmic Center, SUN Yat-sen University, Guangzhou, Guangdong Province, China. MATERIALS: BALB/C mouse embryonic stem cell line Ⅵ (passage 11)was obtained from experimental animal center of SUN Yat-sen University, provided by professor Huang Bing. ESC culture medium was high-glucose DMEM medium with 20% bovine serum and 106 IU/L mouse leukemia inhibitory factor. Induced differentiation medium was high-glucose DMEM medium with 20% fetal bovine.serum and 5×107 mol/L retinoid acid(RA). METHODS: Passage 11 ESCs were resuscitated and incubated by ESC culture medium in incubator at 37℃ with 5% CO2. Passage 11 ESCs were subcultured after 2 or 3 days and RA was added into medium to induce differentiation. Three time points for observation were established: induced for 1, 5 and 9 days. MAIN OUTCOME MEASURES: Morphological changes were observed under inverted phase contrast microscope, MAP-2 antigen expressed in differentiated cells was detected by immunofluorescence method. Immunocytochemistry, Western Blot, flow cytometry assay were used to investigate the Notch1 protein expression. RESULTS: ESCs presented clone-like growth. After induced by RA for 9 days, single neural network was achieved around most of the cell clusters. With the prolongation of induction, MAP-2 positive neural cells increased gradually. Almost all ESC clones expressed Notch1 protein strongly or positively, but Notehl protein expression decreased gradually after induced differentiation (P < 0.01). CONCLUSION: Notch1 signal shuts off progressively during induction of ESCs into neural cells, which suggests Notch1 may play an important role in the differentiation of ESCs into neural cells.

Objective To investigate renal histopathological changes and cli ni cal characteristics in 20 women with preeclamptic nephropathy or gestational pro teinuria.Methods Between 1999 and 2002, 20 women who suffered from preeclampsia or proteinuria during pregnancy underwent postpartum renal biopsies from fifth d ay to third month after delivery. One woman repeated her renal biopsy half year later. Each biopsy specimen was divided into three parts,and processed and stain ed for conventional light microscopy(LM), immunohistology (IH) and electron micr oscopy (EM) examination. The clinicopathological data were studied and women wer e followed up after discharge for a long time. Results Sixteen of 20 women were diagnosed as preeclampsia, whose altered glomeruli demonstrated a typical endoth elial lesion (endotheliosis), and mild to moderate proliferation of mesangial ce lls. IH revealed either negative or mild IgG、IgM and C3 deposits. Focal glomeru losclerosis (FGS) was observed in one of 16 cases, whose microproteinuria (0 49 g/24 h) lasted for more than one year, meanwhile the proteinuria of other 15 wo men disappeared completely within 3～6 months after delivery. Besides, one was I gA nephropathy (IgAN) complicated preeclamptic nephropathy, whose proteinuria de creased obviously after delivery, but remained microhematuria, and endothelial l esion disappeared in repeat biopsy after half year. One was IgAN and received a treatment of adrenocorticosteroid and immunosupressive agents because of macropr oteinuria. One was mild mesangial proliferative glomerulonephritis presenting co nstant microhematuria and microproteinuria. One was typeⅠmembranous nephropathy , whose proteinuria decreased remarkably after delivery as well. Conclusions Ren al histopathological changes of preeclampsis are typical endothelial lesion, and often recover completely within 6 months after delivery. Recovery may be delaye d in the case of FGS accompanied. Pregnancy may aggravate primary renal damage w hich will be improved after delivery. Postpartum renal biopsy is safe and benefi cial to early diagnosis, treatment and prognosis.

Objective To observe the levels of serum 25‐hydroxy(25OH) vitamin D and bone mineral density(BMD) in appar‐ently healthy middle‐aged and elderly people in Zhongshan area and investigate the correlation between each other .Methods The BMD of 200 participants was measured by ultrasound BMD detector ,the participants were divided into 3 groups according BMD re‐sults .Simultaneously ,their serum 25OH vitamin D levels were measured by ECLIA .Results Among 200 participants ,the preva‐lence of vitamin D severe deficiency ,deficiency ,insufficiency and sufficiency w ere 7 cases (3 .5% ) ,35 cases (17 .5% ) ,102 cases (51 .0% )and 56 cases(28 .0% ) ,respectively .There was no significant difference in the BMD values among subgroups of different vitamin D levels(P>0 .05) .The prevalence of low BMD and osteoporosis were 60 cases(30% ) and 10 cases(5% ) ,the levels of ser‐um 25OH vitamin D in normal BMD ,low BMD and osteoporosis group were (67 .31 ± 18 .28) ,(65 .62 ± 15 .41) and (64 .95 ± 19 .86)nmol/L ,respectively .There was no significant difference in the levels of serum 25OH vitamin D among BMD subgroups (P>0 .05) .Serum 25OH vitamin D levels were not directly correlated with BMD(P>0 .05) .Conclusion Vitamin D deficiency and insufficiency are quite serious problems in apparently healthy adults in Zhongshan area .There is no evidence that the status of ser‐um 25OH vitamin D is correlate with BMD ,for laboratory diagnosis of osteoporosis ,more sensitive laboratory markers are needed .

AIM: To investigate the feasibility and effect of directly differentiation of embryonic stem cells(ESC) into neural cells induced by retinoid acid(RA) without embryonic body(EB) culture period in vitro.METHODS: ESC were digested and divided into 4 groups: group A and B were undergone EB culturing.After that,cells in group A were induced by RA,cells in group B were differentiated spontaneously,cells in group C were committedly induced by RA directly without EB culturing,and cells in group D were differentiated spontaneously without EB period.Morphologic changes were observed under inverted microscope and scanning electron microscope.MAP-2 and GFAP were detected by immunocytochemistry and flow cytometry after differentiated for 9 days.RESULTS: In groups A or C,neuron-like cells increased gradually,forming neural network.At the 9th day,a large part of cells in these groups were MAP-2 positive cells,and the positive rate was higher than that in groups B or D(P0.05).CONCLUSION: ESC was directly induced into neural cells by RA without EB culture period in vitro.This modified method has the same effect as the traditional RA 4-/4+ assay and can replace the traditional method.

Objective To investigate the clinical significance of piatelet activity in patients with chronic cor Dulmonale.Methods PAC-1 and CD62p was measured with flow cytometry in whole blood samples from 40 patients and 30 normal controls.The pulmonary arterial pressure was detected through Doppler echocardiography.The arterial partial pressure of oxygen and the carbon dioxide were also analyzed.Results PAC-1 and CD62p increased significantiy (P<0.01).Conclusion Platelet activity is positively related to pulmonary artrial systolic pressure,CO2 partial pressure,and negatively related to O2 partial pressure.

Objective To analyze the change of life expectancy (LE) among residents of Fujian province over the past two decade and to evaluate the impact of age and causes of death on the differences related to LE.Methods Mortality data from Causes of Death Surveillance System of Ministry of Health in Fujian province during 1990-2010 were used to calculate the life expectancy,and Arriaga decomposition method was applied to quantitatively evaluate its changes,based on the age-specific and cause-specific mortality.Results The LE in urban and rural residents of Fujian province had an increase of 5.82 and 11.67 years during the past two decade,respectively,which were higher in urban residents than in rural residents.Although the increment of LE was higher in rural populations than in urban population,the difference of LE between urban and rural was seen narrowed.The contribution rate of children on LE was reducing and the contribution rate of children below 14 years old to LE in rural resident declined from 78.29％ to 31.23％.Middle age and elderly populations had become the major ones that causing the change of LE.The impact of cancer,respiratory diseases and cerebrovascular diseases on LE in urban residents was reducing,while the influence of infectious disease,nervous system disease and cardiac disease was increasing,causing the LE of urban resident increased 1.54,0.67 and 0.49 years,respectively.The impact of respiratory diseases,digestive system diseases,as well as injury and poisoning on LE in the rural residents was reducing,while the effect of cancer,cerebrovascular and cardiac disease increased,causing the LE in the rural resident increased 1.23 years.Different causes of death had different impact on the LE in each age group.Conclusion To reduce the mortality rate in the middle-aged and elderly population and to control the incidence of non-communicable diseases could help to improve the LE in the residents of Fujian province.