Influential factors analysis on the survival time of patients infected with tuberculosis and HIV / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the predictors that reduced the survival time on HIV positive TB patients during their first year's anti-TB therapy.</p><p><b>METHODS</b>A retrospective study was conducted to review 519 TB/HIV co-infection patients from an Internet based TB surveillance system. We collected information of demography, HIV status, CD4+ lymphocytes count, antiretroviral therapy (ART), sputum smear results of diagnosis and around 2 months' initiation of anti-TB therapy, et al. Wilconxon rank sum test was used to compare the difference of age and CD4+ lymphocytes, count and Cox Uni-variable, and Multi-variable analysis were used to compare the different distribution of rest of risk elements between the groups of death and survival; survival function also has been used to evaluate the top 4 risk elements that have made negative impact on the survival time of HIV positive TB patients during their first year's anti-TB therapy.</p><p><b>RESULTS</b>Among 519 TB/HIV patients, 84 (16.18%) were dead, 435 (83.82%) survived. Median age (P50 (P25-P75)) in survival was 51.0 (41.0-65.0), while in death was 45.0 (35.0-60.0) (U=-2.68, P=0.007). There was significant difference between survival and death. Median CD4+ lymphocyte count in survival and death (P50 (P25-P75)) were 69.00 (26.00-131.20) and 114.50 (35.00-245.00), respectively, significant difference also has been observed. Based on the Cox analysis, patients with less than 2 months' intensive anti-TB therapy, poor treatment adherence, less than 4 months continue anti-TB therapy and sputum smear positive around 2 months initiation of anti-TB therapy had higher risk of death, the Relative Risk value (RR) were 1 100.40 (95% CI: 105.62-11,470.00), 52.91 (95% CI: 27.42-102.13), 49.43 (95% CI: 6.38-382.81), and 15.83 (95% CI: 2.55-98.40), respectively. Log-rank test results showed that there were significant difference between survival and death groups with anti-TB intensive therapy duration (Log-Rank value was 236.0, P<0.001), adherence (Log-Rank value was 302.9, P<0.001), and sputum smear results around 2 months' anti-TB initiation (Log-Rank value was 7.55, P=0.006).</p><p><b>CONCLUSION</b>Known HIV positive, less CD4+ lymphocyte count, not initiation of ART, sputum smear positive, around 2 months' initiation of anti-TB therapy, not enough anti-TB therapy duration of intensive and continue period and poor treatment adherence were the predictors of death of HIV positive TB patients in the first year's anti-TB therapy.</p>

Biomechanical finite element analysis of adjacent vertebral bodies following percutaneous kyphoplasty / 中国组织工程研究

BACKGROUND: The incidence of the adjacent vertebral fracture after kyphoplasty is about 2.4%-23.0%, and 2/3 of new fractures occurred in adjacent vertebrae in 6 months. There is controversy addressing the reason which is the development of osteoporosis or the result of bone cement augment at present.OBJECTIVE: To determine the correlations between percutaneous kyphoplasty on adjacent vertebral endoplates stresses pressure under physiologianl load and a new fracture of adjacent vertebral body in physiological load.METHODS: Computed tomography (CT) data of an old female osteoporotic patient was selected, and a three-dimensional finite element model of the osteoporetic thoracolumbar spine T_(12)-L_1-L_2 was created by using kinds of computer aided design software.The height of vertebral L_1 was compressed by 60% to simulated the compressed fracture, and the height of L_1 became the 90% of normal to simulate the replacement, two columns-like PAMA mass (4 mL) was placed in vertebral L_1 to simulate pemutaneous kyphoplasty. The stress on inferior endplate of L_(12) and superior endplate of L_2 was compared with three models. RESULTS AND CONCLUSION: Compared to the normal vertebral body, the maximum stress in the adiacent vertebral bodies endplates increased by 76% for L_1 compress fracture model and increased by 27% for kyphoplasty model, respectively. The stress on the posterior part of vertebral body after percutaneous kyphoplasty have an average increase of 13.2%, of which 4.5% increase in the pedicle, isthmus, and 6.15% increased in the key points 25.6%, but with the wedge-shaped fracture of L_1 vertebral body compared to the model, percutaneous kyphoplasty after pedicle, isthmus and the articular process had reduced stress. The results indicate that the stress on inferior endplate of L-(12) and superior endplate of L_1 increased after percutaneous kyphoplasty under all loading conditions. Increased stress may lead endplate fracture, and increase the risk of adjacent vertebral body fracture. Further researches are needed to support the conclusion.