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Objective To study the features,safe Sex behavior and the size of men who have sex with men(MSM)population in actuaI and virtual venues in one city.Methods We carried out a cross-sectional study in actual and virtual venues,using the Estimated Size of Population from a Single Sample(LMS method)to estimate the size of MSM population.Results Most MSM in actual venues were 24-43 year olds and had received high school education,whereas in virtual venues,the majority of this population were younger than 29 years old and had higher education,including some college students.The awareness of AIDS of the two groups from different venues showed no statistically significant difierence,neither the safe sex behaviors.Proportions of the MSM population in actual and virtuaI venues were 21.22%(16 383,95%CI:11514-21252)and 78.78%(60830,95%CI:57327-64329),respectively.After adjusting the overlapping part of the MSM from both venues,the total number was between 60 830 and 77213,constituting a proportion of 5.03%-6.38%in the sexually active male population(15-64 year olds)in this city.Conclusion The size of the MSM population was large but the characteristics were different in the actual or virtual venues.As most MSM preferred going to the virtual venues,intervention program on AIDS-specific strategy in this area,in particular dealing with the Internet,should be strenthened.
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Objective To investigate the changes of bone mineral density (BMD) and biomechanical properties of the femur after ipsilateral tibia fracture in rats, and its relationship with the tibia fracture union. Methods Forty 3-month-old female SD rats were divided into 2 groups randomly and evenly: the surgery group and the control group. The surgery group received middle shaft fracture and fixation surgery on the right tibia. BMD of the right femur was measured both before the surgery and at 2nd, 4th, 6th, 8th, 10th, 12th week after the surgery, respectively. Ten rats in the surgery group and ten rats in the control group were executed at 6th and 12th week after the surgery, respectively, to test the biomechanical properties of their right tibia and femur. Results The radiological union rate and mechanical union rate of the tibia were 50% and 70%, respectively, at 6th week after the surgery, and those at 12th week after the surgery were both 100%. At 2nd, 4th, 6th, 8th week after the surgery, BMD of the right femur in the surgery group was significantly lower than that in the control group (P<0.05). Compared with the control group, there was no statistical difference in BMD of the right femur at 10th, 12th week after the surgery. Biomechanical properties of the right tibia and femur at 6th week after the surgery showed obviously worse than those at 12th week after the surgery (P<0.05). Analysis showed that the fracture union was highly related with mechanical properties of the tibia (P<0.01), which was also highly related with BMD and mechanical properties of the femur (P<0.001). Conclusions In the early stage of tibia fracture, disuse osteoporosis might occur due to the decrease of BMD and worse mechanical properties in the ipsilateral femur, but as the tibia fracture united, BMD and biomechanical properties of the femur became normal again.
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Objective To determine the risk factors related to tuberculosis infection among people living with HIV/AIDS and to develop strategies for preventing the co-infection.Methods A 1:2matched nested case-control study was carried out to analyze the influencing factors of tuberculosis among people living with HIV/AIDS.Results 1018 people living with HIV/AIDS were followed up for one year with a total number of 736.75 person-years,among them 62 tuberculosis cases were diagnosed.The incidence density of tuberculosis among people living with HIV/AIDS was 8.42 persons per 100 person-years.Factors as education level(OR=0.483),vaccination history of Bacille Calmette Guerin(OR=0.561),CD_4~+ count T-lymphocyte(OR=0.356),unemployment(OR=1.976),living alone(OR=2.646),and smoking(OR=2.215)were significantly related to the prevalence of tuberculosis among people living with HIV/AIDS.Conclusion High education level,with vaccination history of Bacille Calmette Guerin and high level of CD_4~+ T-lymphocyte count were protective factors while being unemployed,living alone,and smoking habit were risk factors related to the prevalence of tuberculosis among people living with HIV/AIDS.
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Objective to explore the current situation and related influencing factors on the retention time of patients receiving methadone maintenance treatment (MMT). Methods Information on basic situation and daily treatment of the patients were collected from the 7 MMT clinics opened in the pro-two batch in Hunan province. Retention rate and influencing factors were analyzed. Results (1) The retention rates after 6 and 12 months of MMT became 72.06% and 49.65% respectively. (2) The retention rates of high-dosage group and low-dosage group were 85.03% and 68.03% after 6 months on MMT program while became 60.48% and 46.28% after 12 months of MMT respectively. (3) The mean retention time of HIV+ patients and HIV- patients were 9.46 months and 8.62 months respectively during the 12 months follow-up observation, showing a significant difference. (4) Patients who took large dose methadone, did not share needles, at older age or HIV+ , were prone to keep MMT at a long period. Conclusion The retention rates for 6 months and 12 months in the MMT program in Hunan province were similar to the national data. Dose, type of drug abuse, age and HIV status were related to the period of retention.
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OBJECTIVE@#To explore the effect of health service and its influential factors in flood disaster areas.@*METHODS@#Fifty-five towns were sampled randomly from Dongting Lake area suffering from flood in 1998. The health service level, effect, and its influence factors were investigated retrospectively.@*RESULTS@#The incidence rate of notifiable infectious diseases was 11.7 per thousand, prevalence rate of chronic disease was 51.2 per thousand, infant mortality rate was 43.1 per thousand, neonatal mortality rate was 10.2 per thousand, and the total mortality rate was 554.3/100,000 in Dongting Lake area. The health investment level was significantly associated with the incidence rate of notifiable infectious diseases, the infant mortality rate, and total mortality rate. Duration of flood and income per capita were important factors for the effect of health investment.@*CONCLUSION@#Increasing health investment and residents' income in the flood disaster area, shortening the duration of flood would play positive role in residents' health in the flood disaster area.
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Humans , China , Epidemiology , Chronic Disease , Epidemiology , Communicable Diseases , Epidemiology , Floods , Health Services , Incidence , PrevalenceABSTRACT
<p><b>OBJECTIVE</b>To probe into the application value of the height shortening value as the self-examination index of the middle-aged and aged group's osteoporosis or reduced bone mineral density in communities.</p><p><b>METHODS</b>Four communities were selected by cluster sampling at random in Changsha city to be the objects of study, among which women were 45 years old or older and men were 60 years old. Difference and the percentage proportion of the height shortening between the height of the research objects which was measured at their youth and the height measured at this study, were calculated. Mineral density of the anteroposterior lumber spine L2-L4, the left femur neck of each object of study with the DPX-IQ dual energy X-ray (DEXA) were both examined. Results examined by DEXA were recognized as "Golden Standards" and different absolute and relative height shortening values were taken as positive cutoff points. Sensitivity, specificity and Youden's index were calculated to draw the receiver operator characteristic curve in order to get the positive cutoff which was most suitable to both sensitivity and specificity, and to calculate the predicative values of that self-examination method among different groups.</p><p><b>RESULTS</b>3 cm of height shortened seemed to be the positive cutoff of the self-examination of osteoporosis, and its sensitivity, specificity and Youden's index were 75.4%, 76.7% and 0.521 respectively. 2 cm of height shortened was suggested as the positive cutoff of the self-examination method of reduced bone mineral density, while its sensitivity, specificity and Youden's index were 81.7%, 75.6% and 0.573 respectively. In this self-examination method, positive predicative value was the highest (76.4%; 88.7%) among the women group aged over 65.</p><p><b>CONCLUSION</b>Certain height-shortening value could be used as the rough index of screening osteoporosis of reduced bone mineral density, which set a simple and easy way of self-examination for the middle-aged and elderly population.</p>
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Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Absorptiometry, Photon , Body Height , Physiology , Bone Density , Osteoporosis , EpidemiologyABSTRACT
<p><b>OBJECTIVE</b>To develop a functional biomechanical mandibular model, and to observe the stress distribution of angle-fractured mandible under different rigid internal fixation (RIF) methods.</p><p><b>METHODS</b>A biomechanical model of mandible was built which include the simulative temporal-mandibular joint (TMJ) and was under mechanical loads of masseter, temporalis, medial pterygoid and lateral pterygoid. The different stress pattern was measured by strain gauges. Under the standard mandibular angle fracture, bilateral molar biting and four pairs of muscles loading, the strains were compared to evaluate the stability of one-or two-miniplate fixation.</p><p><b>RESULTS</b>The fixation of miniplate in the lateral oblique line can recover the main stress on the non-fracture side, but it was broken in the fracture side. The tension increased in the lower border of mandibular angle.</p><p><b>CONCLUSION</b>Through the biomechanical study based on the functional mandibular model, only one miniplate fixation in lateral oblique line for mandible angle fracture was insufficient buttressing of the segments, while the additional miniplate in the lower margin can recover the stress pattern and provide more stability.</p>
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Humans , Biomechanical Phenomena , Bone Plates , Fracture Fixation, Internal , Mandible , Mandibular Fractures , Masseter Muscle , MolarABSTRACT
<p><b>OBJECTIVE</b>To measure the permeability of human temporomandibular joint (TMJ) disc and cartilage to provide basic parameter for oral biomechanics and tissue engineering, and analyze its mechanisms of pathology and load-release.</p><p><b>METHODS</b>Confined compression method was used to measure the permeability (k value) of four cadavers' TMJs, which were sampled into three parts: disc, condyle and glenoid fossa with different diameters (2 mm, 3 mm and 4 mm). All 128 samples were tested with correspond diameter indenter.</p><p><b>RESULTS</b>Larger the sample diameter was, higher the k value became. The highest k value appeared in the disc while the lowest appeared in glenoid fossa.</p><p><b>CONCLUSION</b>In normal condition, TMJ can suffer huge load by decreasing its permeability. Disc is weakest for the higher permeability, it's easy-damaged region is an initiated factor of TMJ disease.</p>
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Humans , Cartilage , Permeability , Temporomandibular Joint Disc , Tissue EngineeringABSTRACT
<p><b>OBJECTIVE</b>To introduce cryotreat technique into prosthetic dentistry by testing the tensile properties of CW-H Co-Cr-Mo cast alloy before and after cryotreat and to observe the image changes by SEM to study the mechanism that changes the tensile properties of the alloy.</p><p><b>METHODS</b>15 CW-H cast alloy were divided into 3 groups, i.e. control group (G1), cryotreated group (G2) and cryotreated plus post-cryogenic treated group (G3). The gauge test technique was employed to test the modulus of elasticity. Then the strength and percentage elongation (PE) were tested. SEM images were used to analyze the mechanism that improved the tension properties of the alloy.</p><p><b>RESULTS</b>For CW-H alloy the strength and the modulus of elasticity of both G2 and G3 were effectively increased but PE effectively decreased than G1. There was no effectively difference between G2 and G3, but G3 was larger than G2. SEM images of G2 and G3 showed that secondary-carbonide separated out all over the alloy.</p><p><b>CONCLUSION</b>The results obtained above suggest that cryotreat is an effective method in enhancing tensile properties of CW-H Co-Cr-Mo cast alloy.</p>