Mechanical loading plays an important role in stimulating osteogenesis. Increasing mechani-cal loading, via sports and mechanical vibration may increase bone mass and imluce better microstructure, where-as, lack of mechanical loading in the situation like space walking, long bed-ridden, ete, results in bone loss and osteoporosis. Although the mechanism through which mechanical loading stimulates bone formation is not clear, experiments have proved that local mechanism is more important than systematic mechanism. This article aims to review the local mechanism of mechanical loading stimulating osteogenesis.

AIM: To observe the effects of D-galactose on the lumber vertebra body and investigate the reasons. METHODS: 12 rats at age of 6 months were divided into two groups, control group and D-galactose group (n=6 in each). The control group were administered saline solution sc, and the D-galactose group were administered 5% D-galactose solution sc at dose of 100 mg?kg -1. After 3 month, the rats were killed by exsanguination from heart. The fourth lumber vertebra was taken and immerged in formalin. The testicle were taken and immerged in formalin at the same time. The blood serum was collected by centrifugating the collected blood after resting for a while, and it was preserved in refrigeratory at the degree of - 70 ℃.The vertebra body were embedded in plastic and sliced up after being dehydrated step by step with different concentration ethanol. The slices were analyzed under the image analysis apparatus. The testicle were made into paraffin slices and observed under the common microscope. The concentration of serum testosterone and luteinizing hormone were measured by radio-immunity assay. RESULTS: The lumber vertebra body in D-galactose group appeared osteoporosis. The serum testosterone hormone concentrations of D-galactose rats were significantly decreased. And the microstructure of testicle present aging change, but no change of serum LH concentration was observed. CONCLUTION: D-galactose can cause the osteoporosis in male rats, which may be related to affect the function of thalamus-pituitary-testicle axis, decrease the content of testosterone of D-galactose.

AIM: To investigate the effects of D-galactose on ultrastructure of rats' hypothalamic arcuate nucleus.METHODS: 12 rats at age of 6 months were divided into two groups at random,the control and D-galactose group.Rats of control group were treated with saline solution by sc,and rats of D-galactose group were treated with D-galactose by sc at dose of 100(mg?kg~(-1)). Three months later the rats were killed by exsanguinating from heart.After being infused into the left ventricle with 2%-(2.5)% polyformaldehyde at the dose of 50(mg?kg~(-1)),the brains were taken and immerged in(2.5)% polyformaldehyde,then the arcuate nucleus was taken according to the atlas of brain,the tissues taken were made into ultrathin sections to be observed under electron microscope.RESULTS: comparing to rats in control group,neurons of the arcuate nucleus of rats in D-galactose group appeared aging,the number of organelle in plasma decreased,but the number of lipochromesome in plasma increased significantly,and the size of neurons decreased also.Furthermore the apoptosis neuron was observed,the chromosome of which congregated around the nucleus' membrane,the typical aging neuron was also observed,the neuraxon of which was atrophying.But there were no obvious changes observed in neurons of the arcuate nucleus of rats in control group,plenty of organelles were observed under electron microscope clearly.CONCLUSION:D-galactose can cause neurons of rats' arcuate nucleus aging,the neurons appeared atrophying and apoptosis.

Objective To assess the status of mental health of nursing students of secondary technical school and provide targeted guidance for mental health education. Methods 642 nursing students of secondary technical school were assessed using Mental Health Diagnostic Test Scale (MHT Scale). Results There were 0.78% of nursing students with serious psychological problems (scores≥65), 4.52% of nursing students with less serious psychological problems (scores < 65 and≥ 56). Students in different grades had significant difference in learning anxiety, allergic tendency, physical symptoms anxiety. Conclusions Nursing students of secondary technical school were in good mental health in general, but there were many students had learning anxiety, allergic tendencies and physical symptoms anxiety, which were different among various grades. Secondary nursing schools should further strengthen the mental health education, and seek close collaboration with parents,provide appropriate intervention measures to the nursing students with psychological barriers, in order to enhance the overall mental health of nursing students.

Objective To explore the relationship between the expression of caveolin-1 and pathological grade, clinical stage in bladder carcinoma. Methods Caveolin-1 expression was detected in 63 cases of bladder carcinoma and 10 cases of normal bladder epithelial tissue using SABC immunohistochemistry. The clinical and pathological data of the patients were collected and used to make statistical analysis. Results The normal bladder mucosal epithelia had not caveolin-1 expression, while the positive rate of caveolin-1 expression was 34.92% in bladder carcinoma. The positive rates of caveolin-1 expression in the grades I, II and III of bladder carcinoma were 0%, 2.86%, 54.28%, respectively, which had a significant difference(P

Aim To study the effects of D-galactose o n bone of rats. Methods Forty-two Sprague-Dawley rats at age of 3 months with half female and half male were divided into five groups randoml y, basal, OVX or ORX , D-galactose at dose of 50 mg?kg -1?d -1 (L), D-galactose at dose of 100 mg?kg -1?d -1 (M), galactose a t dose of 200 mg?kg -1?d -1 (H).The former two groups were SC inject ed physiological saline and the latter three groups were injected three differen t doses of D-galactose respectively. Two months later the rats were killed by setting blood free from hearts, then the left thighbones and tibias were take n. The tibias were cut at 8 ?m sections for static and dynamic bone histomorph ometric analyses. The thighbones were dried and weighed. All rats were given sc injections of tetracycline 25 mg?kg -1 (first fluorochrome bone marker) on 14 and d 13,and calcein 10 mg?kg -1(second fluorochrome bone marker) on 4 and d 3 before sacrifice. The testicles and the ovaries were taken and made the paraffin slices for observing the microstructure under the microscope. Results D-galactose had no effects on bone of female rats, but can made male rats lose bone significantly and the rats appeared osteoporosis. The static parameters in three different dose male rats bone which relate to bone ma ss %Tb. Ar decreased 53.5%,53.5%,46.6% respectively, Tb.N decreased 42.9%,4 7.6%,38.1% respectively, TB.Sp increased 85%,150%,67.3% respectivly. The dynamic parameters which relate to bone formation %L. Pm decreased 24.1% 89.1% , 65.5% respectively. The convoluted suminiferous tubule disordered, lumens dil ated, and basal membrane disintegrated. Conclusion D-galac tose had different effects on bone of different gender rats. There is no effect on female bone, but it can induce the male rats osteoporosis. The mechanism of D-galactose on bone was probably due to the different effects on gonad glan ds.

Objective To induce the site-directed mutation of human cardiac troponin I (cTnI) gene, express the mutant in E. coli, and to study the effects of the mutation on the prokaryotic expression of cTnI. Methods The cDNA encoding cTnI was cloned with RT-PCR from the total RNA extracted from human myocardium tissues. A pair of primers was designed and, after the mutations were induced at the second and the fourth codons, inserted into prokaryotic vector pET-28c (+) and transform the recombinant to BL21 (DE3) bacteria. After purified with Ni-NTA resin, the histidine-tagged fusion protein expressed by IPTG-induced was identified by Western blotting and the expression yield of cTnI protein was investigated. Results The expression of the recombinant carrying processed cTnI cDNA was stronger than that in control group. Conclusion cDNA encoding cTnI was successfully cloned. The recombinant with mutations can be more efficient expressed in E. coli. The cTnI protein can be purified to near homogeneity.

Objective To explore the application of self-made guided wire operating-tray,which is designed for percutaneous tranluminal coronary angioplasty (PTCA),in performing coronary intervention (PCI).Methods A total of 40 patients who were planned to receive PCI were randomly divided into the study group (n=20,using guided wire operating-tray) and the control group (n=20,using traditional method to operate guide wire).Under local anesthesia PCI was carried out in all patients of both groups.The frequency of guide wire winding,the degree of surgical sheet contamination within the operation area,and the comfort and convenience of operating guide wire were assessed,the results were compared between the two groups.Results The frequency of guide wire winding and the degree of surgical sheet contamination within operation area in the study group were remarkably lower than those in the control group (P＜0.05).The comfort and convenience of operating guide wire in the study group was better than that in the control group (P＜0.05).Conclusion In performing PCI,the use of self-made guided wire operating-tray can effectively avoid guide wire winding and reduce the degree of surgical sheet contamination within the operation area.

Objective To find out the relationship between the weight and whole body averaged SAR. and the relationship between the weight and the EM energy absorption in rat model exposed to 3 GHz microwave irradiation.Methods Based on 3D rat NMR images,a rat EM model consisting of 45 tissues was established, then by changing the size of model cell,16 models of which the sizes varied from 9 cm to 24 cm, and the weights from 16 g tO 334 g correspondingly were established too.Using FDTD method,the induced electric fields in these rat models were calculated,and then SAR and EM energy absorption have been obtained accordingly.Results The relationship between the weight and the whole body averaged SAR of rat model exposed to 3 GHz microwave irradiation can be divided into three sections,and each of them can be fitted into one line.In small rat section, SAR changed sharply;in middle rat section,SAR changed moderately;in large rat section,SAR changed litflely.The relationship between the weight and the EM energy absorption of rat model were fitted into one quadratic polynomial curve.The EM energy absorption was almost identical when the model is small,with the increasing of the weight,the EM energy absorption also increases,but the increasing ratio of the energy is less than that of the weight.Conclusions Larger rat absorbs more EM energy,but gets less SAR.Exposed to the same irradiation,the dose differences of larger rat is much less than that of smaller rat because of the changes in body weight,so the larger rat is to be recommended.

Objective To investigate the radiosensitivity of silencing N-Ras by RNA interference in hepatoma carcinoma cell MHCC-97.Methods N-Ras RNA interference (RNAi) vector was constructed by using pcDNA 6.2-GW/EmGFP-mir plamid.The RNAi effect was detected by RT-PCR,Western bolt,immunohistochemisty and MTT method.Survival curve for each cell line were obtained by measuring the clone forming abilities of irradiated cell populations.Results After silencing the N-Ras by RNAi,The expression level of N-Ras mRNA,N-Ras protein,immunohistochemisty were decreased 96.9% ±0.159%(t=40.377,P＜0.05),89.8%±0.012% (t=31.595,P＜0.05),90%,respectively,and The survival of hepatoma carcinoma cell MHCC-97 line were inhibited 21.9% (F = 4.63,P < 0.05).Which have significant difference in statistics.The SER of hepatoma carcinoma cell MHCC-97 line after interference was 1.15.Conclusions RNAi targeting silence N-Ras may increase the radiosensitivity of hepatoma carcinoma cell MHCC-97 line.