AIM:To observe the characteristics of estrous cycle of female ICR mice and ovariectomized mice that had reached sexual maturity stage .METHODS:ICR mice were randomly divided into 3 groups, normal group, sham operation group and ovariectomized group .After ovariectomy and sham operating , at the 8th day, the mice were taken vagi-nal smears twice daily (09:00 and 16:00) for 12 consecutive days.The feature of vulva in the mice and vaginal smear cy-tology, occurrence rate of regular estrous cycle , duration of estrous cycle and each stage duration of estrous cycle were re -corded and observed .RESULTS:The characteristics of estrous cycle in normal group and sham operation group were simi-lar.Nearly 85%of the ICR mice in sexual maturity stage showed regular estrous cycle .The majority manifested 6-day cy-cle (83%), and only a small number exhibited 5-day cycle (17%).Compared with 5-day group, the duration of oestrus was significantly increased in 6-day group (P<0.05).The number and kind of the cells in vaginal smear were a little dif-ferent between 5-day and 6-day groups.The ovariectomized mice which showed irregular estrous cycle (76%) were charac-terized by continuous diestrus .CONCLUSION:Female ICR mice have the strain characteristics of estrus cycle .

Objective To investigate the correlation between serum insulin,lipid expression substances and breast cancer.Methods From January to August 2002,blood samples were collected from 90 patients with breast cancer,40 patients with breast benign disease and 100 healthy control subjects in Shanxi Province People Hospital.Serum insulin was measured by ELISA,serum leptin was measured by radioimmunoassay (RIA) and serum lipid substances were measured by Biochemistry Auto-machine.Results The serum insulin,leptin and TG concentration were significantly higher,but the HDL level was significantly lower in breast cancer group than in the groups of breast benign disease and healthy control(P＜0.01,respectively);There was no statistically significant difference between postmenopausal and premenopausal women in patients with breast cancer and breast benign disease(P＞0.05);There was no statistically significant difference in serum insulin level between positive lymph node breast cancer and negative lymph node breast cancer(P=0.642);The relative risk (RR) of serum insulin level and body mass index(BMI) in breast cancer group was 0.164(P＞0.05).The increased serum insulin level was independent of diet and other known risk factors for breast cancer;Multiple logistic regression analyses observed a statistically significant association between serum insulin,leptin,TG and HDL levels and breast cancer,OR=1.120(95% CI:1.017～1.209),1.117(95% CI:1.046～1.193),OR=1.879(95% CI:1.148～3.076),OR=0.035 (95% CI:0.007～0.162),respectively.Conclusion The increased serum insulin,leptin and TG levels may be the risk factors of breast cancer.The increased serum HDL level maybe the protective factor of breast cancer.

OBJECTIVE:To discuss the effect of tanshinone Ⅱ A on the apoptosis of HeLa cell line and its mechanism.METHODS:MTT was used to measure the levels of the proliferation of HeLa cells cultured with tanshinone Ⅱ A in different concentrations.The apoptosis was measured by Hoechst33258 staining,and the level of mRNA of Bcl-2 and bax in HeLa cells was tested by semi-fix quantify RT-PCR method.RESULTS:Tanshinone Ⅱ A could inhibit the proliferation of HeLa cells in a dose dependent manner,induce cell apoptosis,and markedly decrease the expression of Bcl-2 on mRNA level after treatment for 48h,while it had no obvious change in bax mRNA level.CONCLUSION:Tanshinone Ⅱ A can inhibit the proliferation of HeLa cells and induce the apoptosis of the cells.

Objective To investigate the relationship of plasma level of brain natriuretic peptide (BNP) and left ventricular hypertrophy (LVH) in patients with essential hypertension. Methods The plasma level of BNP was measured with electrochemiluminescence immunoassay method in 32 hyper- tensive patients without left ventricular hypertrophy (LVH) (NLVH group), 30 patients with essen- tial hypertension with LVH (LVH group), and 30 healthy adults (control group). Doppler echocar- diography was employed to determine left ventrieular mass index (LVMI) and observe the correlation of plasma BNP level with LVMI. Results The plasma BNP level was significantly elevated in LVH group than that of NLVH group and control group (P<0.01). The plasma BNP level was significant- ly higher in NLVH group than that of control group (P<0.01). BNP level was positively correlated with LVMI in hypertensive patients with LVH (r= 0.64, P<0. 01). Conclusion BNP level may reflex the degree of left ventricular hypertrophy in patients with essential hypertension.

microRNA with 22 nucleotides in length are a growing family of small non-coding RNA that function as post-transcriptional regulators of target genes in eukaryote.Recent study indicates that microRNA are closely related to the oncogenesis additional to its biological function in the regulation of cell proliferation,differentiation and death.This review proposes the progresses on the study of(microRNA,) including the biological character,biogenesis and function,and its relationship with cancer.

China launched the nationwide resident standardized training (residential training) project since 2013 and has trained a large number of general practitioners. The primary health care institutions and general practitioners have played an important role during the prevention and control of COVID-19 epidemic, which not only presented the remarkable effect of residential training project, but provided new ideas for the further training program of general practitioners. It is proposed in this paper that we should adjust the training and assessment priorities in the following aspects: highlight the characteristics of general practice in the future training, so as to train general practitioners with more comprehensive ability, such as strengthening the ability to deal with public health emergencies, strengthening the consciousness and capability of scientific research, and increasing the proportion of humanistic quality training; At the same time, we should enhance career attractiveness of general practitioners to keep the excellent general residents stay for their career;All mentioned above will further improve the overall quality of general practitioners, and enable them to better deal with public health emergencies.

One hundred and thirty general practitioners ( GP ) who received standard training ( training group ) and 189 GPs who did not receive standard training ( non-training group ) were selected with cluster random sampling method from five districts in Beijing.A questionnaire survey was conducted from April to May 2013, including basic information , working condition , professional competency and continuing education of the interviewees.The survey showed that 72.3%(94/130) in training group had physician titles;89.3%(116/130 )had work experience <10 y;97.0%(126/130)of them had bachelor degree or above;82.3%(107/130) expressed their interest in scientific research , but the 95.4% of them had no research projects;and 96% had no teaching appointment.GPs in non-training group were in a favorite position of education level and professional competency over those in training groups ; however , the latter were highly enthusiastic in further training and scientific research , and had strong potential for career development.

Objective To investigate the mutual effect between G protein-coupled receptors(GPCR)including C5a receptor(C5aR),C5a like receptor 2(C5L2)and chemotaxis inhibitory protein(CHIPs)secreted by Staphylococcus aureus.Methods The purified CHIPs was incubated with HEK 293T cells overexpressing C5aR,C5L2 and C-X-C chemokine receptor type 3(CXCR3).Binding signal was detected by Western blot.Results HEK 293T cells overexpressing C5aR can efficiently bind to CHIPs.No apparent relation between CHIPs and C5L2 or CXCR3 was identified.Conclusion C5aR but not C5L2 is a membrane receptor for binding CHIPs,suggesting a difference between C5aR and C5L2 in association with binding CHIPs.

Neuregulin-1,a member of the epidermal growth factor family,plays an important role in the neuronal survival,development,migration,myelin formation,and synaptic plasticity and function. This article mainly summarized the structure and function of neuregulin1 and its neuroprotective roles in cerebral ischemia. Tne neuroprotective mechanisms of neuregulin-1 may include the inhibition of the early inflammatory response and apoptosis,and the regulation of the expression the neurotrophic factors.

Objective To evaluate the effect of dexmedetomidine pretreatment on activation of Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway during intestinal injury in rats undergoing liver transplantation.Methods Thirty-two pathogen-free healthy adult male Sprague-Dawley rats,weighing 220-250 g,aged 8-10 weeks,were divided into 4 groups (n =8 each) using a random number table:sham operation group (S group),liver transplantation group (LT group),dexmedetomidine pretreatment group (D group) and dexmedetomidine plus atipamezole (specific α2-adrenergic receptor antagonist) group (D+A group).The model of liver transplantation was established in LT,D and D+A groups except group S.In group D,dexmedetomidine 50 μg/kg was injected intraperitoneally at 30 min before skin incision.In group D+A,atipamzole 250 μg/kg was injected intraperitoneally at 5 min before administration of dexmedetomidine.At 6 h of reperfusion,blood samples were collected from the inferior vena cava for determination of serum concentrations of intestinal fatty acid binding protein (iFABP),lipopolysaccharide (LPS),tumor necrosis factor-alpha (TNF-ct) and high-mobility group box 1 protein (HMGB1).Intestinal specimens were then obtained for examination of the pathological changes of intestinal tissues (under light microscope) and for determination of the expression of activated caspase-3,phosphorylated JAK2 (p-JAK2),phosphorylated STAT1 (p-STAT1) and phosphorylated STAT3 (p-STAT3).Intestinal damage was assessed and scored.Wet/dry weight ratio (W/D ratio) was calculated.Results Compared with group S,the concentrations of iFABP,LPS,TNF-α and HMGB1 in serum,intestinal damage scores and W/D ratio were significantly increased,and the expression of activated caspase-3,p-JAK2,pSTATI and p-STAT3 in intestinal tissues was up-regulated in LT and D groups (P＜0.05).Compared with group LT,the concentrations of iFABP,LPS,TNF-cα and HMGB1 in serum,intestinal damage scores and W/D ratio were significantly decreased,and the expression of activated caspase-3,p-JAK2,p-STAT1 and p-STAT3 in intestinal tissues was down-regulated in group D (P＜0.05).Compared with group D,the concentrations of iFABP,LPS,TNF-cα and HMGB1 in serum,intestinal damage scores and W/D ratio were significantly increased,and the expression of activated caspase-3,p-JAK2,p-STAT1 and p-STAT3 in intestinal tissues was up-regulated in group D+A (P＜0.05).The pathological changes of intestinal tissues were significantly attenuated in group D as compared with group LT.Conclusion The mechanism by which dexmedetomidine pretreatment reduces intestinal injury may be related to inhibition of JAK/STAT signaling pathway activation in rats undergoing liver transplantation.