Objective To reduce experimental costs and improve the utilization of S9, we use spiral coating technique to evaluate the activity of rat liver S9 prepared by combination inducing method as well as to establish cryopreservation method.Methods Using spiral coating technique and Ames test to evaluate the activity of self-made rat liver S9 and commercially available S9 separately.We use glycerinum as protective agent to establish cryogenic storage method, so that S9 can be in liquid form stored at -20 °C in the refrigerator.Results In the Ames assay as well as using spiral coating technique, the number of revertant colonies had dose-response relationship among the dose of S9.When conditions were the same, the number of revertant colonies in positive control was at the approximate level in presense of self-made rat liver S9 and commercially available S9 respectively.When S9 ( concentration of 38%) was added to the amount at 1.48 ~6.62 μL /μL broth dose of bacteria, it can significantly induced Salmonella typhimurium histidine strains TA100, reverse mutation rates were three times more than the control group.Conclusions Spiral coating technique can successfully evaluate the activity of rat liver S9.The inducing method of combination of PB and BF can take the place of the unducing method of PCBs in the preparation of Liver homogenate S9.

Objective To investigate the relationship between hyponatremia(HN) and the plasma level of C-type natriueetic peptide(CNP) in patients with hypertensive intracerebral hemorrhage(HICH).Methods Radioimmunoassay was applied to determine the plasma concentrations of CNP in 36 patients with HICH and the concentrations of serum sodium were measured.Results The mean plasma level of CNP in 6 cases with HN(24.6?3.98 mg/ml ) was significantly increased compared with that in 26 cases without HN(21.1?3.23 mg/ml)( P

0.01). The new caries did not occur in the test group. DMF index was higher in the controls than that in the tested subjects(P

Abstract:Objective To study the pathogen of root surface caries in the elderly. Methods Plaque samples from the experimental group and the control group were collected. After culturing in selective and non-selective media, the different bacteria were isolated. The counts and the positive rates of total bacteria, porphyromonas group, pervotella group, streptococcus mutants group, actinomyces group and lactobacillus group were compared.Results The counts of total bacteria, streptococcus mutants, actinomyces and lactobacillus of the experimental group were higher than those of the control group. The positive rates of actinomyces and lactobacillus of the experimental group were significantly higher than those of the control group. Conclusion Actinomyces and lactobacillus are the main related pathogens of root surface caries in the elderly.

Objective To investigate the effect of doxapram on inhibition of medullary respiratory center excitability by sevoflurane in rats.Methods Neonatal Sprague-Dawley rats of both sexes,aged 1-4 days,were used in this study.Isolated medulla oblongata-spinal cord specimens were made according to the method described by Suzue and perfused with the artificial cerebrospinal fluid saturated with 95％O2-5％CO2.The specimens were randomly divided into 3 groups ( n =9 each):control group (group C),sevoflurane group (group S) and sevoflurane + doxapram group (group S + D).Respiratory rhythmical discharge activity of the hypoglossal nerve rootlets was recorded using suction electrode.After 10 min of equilibration,the specimens were perfused with the artificial cerebrospinal fluid,5％ sevoflurane and the mixture of 5％ sevoflurane and 5 μmol/L doxapram for 10 min in groups C,S,and S + D respectively.The respiratory cycle,inspiratory time and integral amplitude of inspiratory discharge were recorded.Results Compared with group C,the respiratory cycle was significantly prolonged,the inspiratory time was significantly shortened,and the integral amplitude of inspiratory discharge was significantly decreased in group S (P ＜ 0.05),and no significant change was found in the parameters mentioned above in group S + D (P ＞ 0.05).Compared with group S,the respiratory cycle was significantly shortened,the inspiratory time was significantly prolonged,the integral amplitude of inspiratory discharge was significantly increased in group S + D ( P ＜ 0.05).Conclusion Doxapram antagonizes sevoflurane-induced inhibition of excitability of medullary respiratory center in rats.

Objective To investigate the stress changes of intervertebral disk of degenerative scoliosis (DS) after treatment with short-segment internal fixation and fusion.Methods Based on the DS patient's CT images of the successive spinal column from T12 to superior segment of S1,assigning special material attributes to the model and forming the integrated and effective three dimensional finite element model of DS.Treated with the short-segment (one-segment and two-segment) spinal canal decompression +intervertebral bone fusion+pedicle screw internal fixation.Loading the model on the following postures:anteflexion,postextension,left lateral inclination,right lateral incliniation,left rotation and right rotation.Calculating and analyzing the stress distribution of intervertebral disk and comparing to that of the preoperative normal DS model.Results The stress of intervertebral disk after the short-segment internal fixation and fusion was increased than that of preoperation.The rotation motion affected greater to the upper intervertebral disk of fixation segment and the extension motion affected greater to the inferior intervertebral disk of fixation segment.The increase of stress of upper and inferior intervertebral disk of fixation segment treated with one-segment fixation and fusion(average was 6.03,4.58 MPa,separately) was greater than that of the two-segment fixation and fusion (average was 5.24,4.47 MPa,separately),but there was no statisticdifference (P ＞ 0.05).Conclusions The short-segment intemal fixation can increase the intervertebral disk stress of adjacent segment fixation of DS.The effect on the stress of upper and inferior intervertebral disk of fixation segment of one-segment fixation and fusion is greater than that of two-segment fixation and fusion.And the patient should avoid the rotation and extension movements after treated with the short-segment internal fixation and fusion.

BACKGROUND:Spine is relatively complex in structure, shape, material properties, and load bearing. The traditional biomechanical method cannot solve these problems. OBJECTIVE:To investigate the stress distribution of intervertebral disc, zygapophysial joints and vertebral body of degenerative scoliosis, and to provide accordance to the biomechanical mechanism of degenerative scoliosis occurrence and development. METHODS:Based on the successive CT images of spinal column from T12 to superior segment of S1 of degenerative scoliosis patients, the special material properties were attributed to the model to form the integrated and effective three-dimensional finite element model of degenerative scoliosis. The model was loaded on the anteflexion, extension, left lateral bending, right lateral bending, left rotation and right rotation conditons. Then the spinal activity and the stress distribution of intervertebral disc, vertebral body and articular cartilage of zygapophysial joints were calculated and analyzed. RESULTS AND CONCLUSION:The spinal activities of degenerative scoliosis finite element model were less than those of common lumbar spine. The stress distribution of intervertebral disc was inclined to the verge of it and the greatest stress was appeared on the extension motion. The apex of scoliosis was the place of stress concentration and the obvious stress concentration of articular cartilage of zygapophysial joints was appeared on the rotation motion, then fol owed by the extension motion, especial y that of articular cartilage of zygapophysial joints on the apex of scoliosis. Stress concentration is easily appeared on the apex of scoliosis, and the extension and rotation motion can aggravate the development of degenerative scoliosis.

Objective To evaluate the alteration of CD4+ regulatory T cells in peripheral blood from patients with ankylosing spondylitis(AS). Methods Seventy-eight AS patients and 50 healthy individuals were included in this study. The proportion of CD4+CD25+CD127lo/- T cell population in CD4+ T cells as well as that cytotoxic T lymphocytes(CTL) and NK cells in lymphocytes was evaluated by flow cytometry. Serum TGF-β and TNF-α were measured by ELISA. The inhibitory function of CD4+CD25+ regulatory T cells was measured by mixed lymphocyte culture. Results The population of CD4+CD25+CD127lo/- T cells in peripheral blood of AS patients accounted for (4.36±1.21)% of CD4+ T lymphocytes, which was significantly lower than that in healthy individuals (P<0.05). The CD4+CD25+CD127lo/- T cells population in AS patients was positively correlated with TGF-β level, but negatively with TNF-α. Compared with healthy individuals, the function of CD4+CD25+ regulatory T cells in the inhibition of alloreactive T cells was lower in AS patients, which was related to the decreased secretion of TGF-β. Conclusion The CD4+ regulatory T cells in peripheral blood of AS patients are significantly decreased and its function is defective, which leads to immune regulatory dysfunction in vivo. It may be one of immune pathogenesis mechanisms of AS.

Objective:To investigate outpatient's medicine knowledge and satisfaction degree and analyze their correlation.Method:150 outpatients,their doctors and pharmacists were investigated with a fieldwork method.Patients' medical knowledge and satisfaction degree were measured with a quantitative scale table,and their correlation was calculat- ed with a linear regression method.Result:Almost all the doctors and pharmacists could provide their patients with their guidance about medicines,which focused on drug dosage and taking ways.Fewer than 20% patients could take medical ad- vice of potential risks and notice of taking medicine.A significant correlation was shown between patient's medical knowl- edge and satisfaction degree(r=0.76).Conclusion:More guidance from doctors and pharmacists should be provided for outpatients.The medical knowledge learned by patients could influence patient's satisfaction degree significantly.

BACKGROUND: The complicated localization of intramedullary nails and osteotomy more dependent on surgeons' experience limit the application of conventional total knee arthroplasty (TKA). The occurrence of three-dimensional (3D) printing technology can achieve precise localization and osteotomy in TKA.OBJECTIVE: To explore the effectiveness of 3D printing technology-aided TKA versus conventional TKA for genu varum.METHODS: Thirty-four patients with genu varum undergoing primary unilateral TKA were recruited and were then divided into two groups (n=17 per group) in accordance with the random number table. One group was treated with TKA with 3D printing guild plate (3D printing group), while the other group received the conventional TKA (conventional group).The intraoperative and postoperative blood loss, operation time, as well as the Hospital for Special Surgery score, range of motion, and lower limb mechanical alignment at 2 weeks postoperatively were compared between two groups.RESULTS AND CONCLUSION: (1) The range of motion of knee in the 3D printing group was larger than that in the conventional group, but had no significant difference at 2 weeks postoperatively (P=0.744). (2) There was no significant difference in the Hospital for Special Surgery scores between two groups at 2 weeks postoperatively (P= 0.532). (3) The postoperative lower limb mechanical alignment showed no significant difference between two groups (t=0.218, P=0.632).(4) The operation time in the 3D printing group was significantly shorter than that in the conventional group (P=0.000). (5) The blood loss in the 3D printing group was significantly less than that in the conventional group (P=0.000). (6) Our findings indicate that 3D printing technology-aided TKA exhibits similar results to the conventional TKA in the Hospital for Special Surgery scores, range of motion, and lower limb mechanical alignment, but it shortens the operation time,reduces the blood loss, and achieves precise osteotomy, which is available for the elderly with poor basic condition, and weak tolerance of surgery.