Injury risks and affecting factors of spinal loads for caregiver’s manual patient handling tasks / 医用生物力学

Objective To assess the injury risks and affecting factors of spinal loads at L5/S1 joint for caregivers during manual patient-handling tasks, so as to find a suitable handling way to effectively reduce such risks. Methods Kinetic data were collected from nine female caregivers performing six patient handling tasks on three agent ‘patients’ with different weight. Peak L5/S1 force was calculated based on a multi-segment three-dimensional model to investigate the characteristics of injury risks, and the correlations between the peak L5/S1 force and six affecting factors were specifically analyzed. Results Peak compression of the tasks all exceeded the safe thresholds of 3.4 kN; Peak anterior-posterior force for those repositioning tasks were above the threshold of 0.5 kN. Different tasks showed different biomechanical characteristics for risk of injury and affecting factors, and there was a significant correlation between the L5/S1 loads and the moving distance of center of gravity, and the ground reaction force as well (P<0.01). Conclusions Manual patient handling tasks could cause different injury risks by high loads on spinal low back. Decreasing the range of motion of the whole body and avoiding jerk movement during the patient handling tasks would help caregiver to reduce the injury risks.

Research progress on the light-weight and low-cost systems for human motion balance measurement / 医用生物力学

The mechanism of balance controlling and maintaining during human motion is quite complex, and many physiological and non-physiological factors such as aging, apoplexy and limb disability can lead to balance dysfunctions.Thus, the functional tests and evaluation on balance plays a vital role in the diagnosis and evaluation of many diseases. The common equipment and methods for investigating balance funciton of human body, as well as their limitations were summarized, and the design and method of serveral light-weight, low-cost, novel systems such as wearable motion capture systems based on microelectronic sensors and human balance measuring and training systems based on somatosensory games were also proposed in this paper.

Nonlinear time series analysis of gait stability during walking / 医用生物力学

Objective To investigate the gait stability of healthy old and young adult volunteers during walking using the nonlinear time series analysis method so as to comprehensively assess the dynamic balance of human and provide important references for the prediction of fall risk. Methods The Vicon motion capture system was used to collect three-dimensional kinematic data of healthy volunteers (seven old subjects and ten young subjects) at different walking speed (80%, 100%, 120% of the natural walking speed). The anterior-posterior and medio-lateral motions of the seventh cervical and tenth thoracic vertebrae, as well as the flexion-extension and abduction-adduction angles of the lower extremity joints, were obtained from 30 consecutive gait cycles to calculate the largest Lyapunov exponents and analyze the difference of gait stability between the old and young group and the influence of walking speed on gait stability. Results The gait stability in the young group was better than that in the old group, and there were significant differences in certain motion segments (P＜0.01). The gait stability in both groups were reduced with the increase of speed (P＜0.05). Conclusions The largest Lyapunov exponent based on nonlinear time series analysis method can be used to effectively and quantitatively analyze the gait stability of each motion segment in human during walking.

Evaluation of left ventricular mechanical dyssynchrony in patients with heart failure after myocardial infarction by real-time three-dimensional echocardiography

To evaluate the incidence and prevalence of left ventricular [LV] dyssynchrony in patients with heart failure after myocardial infarction [MI] by realtime three-dimensional echocardiography [RT-3DE], and to investigate the clinical application value of using RT-3DE as a method of providing more detailed information for clinical strategy. This cross-sectional study was carried out in Renmin Hospital of WuHan University, Hubei Province, China from July 2009 to December 2010. The RT-3DE was performed on 43 patients with chronic heart failure after MI and 30 normal subjects, to analyze LV volume and left ventricular ejection fraction [LVEF], also the LV systolic dyssynchrony index [SDI]. The dyssynchrony rate of the total MI patients was 83.7%, and was 100% in the severe dysfunction group. The SDI of MI patients was significantly higher than the control subjects [p<0.01], and the SDI of those whose LVEF

Protective effect of DNA vaccine with the gene encoding 55kDa antigen fragment against Pneumocystis carinii in mice

OBJECTIVE@#To evaluate the protective effect of DNA vaccine with the gene encoding 55kDa antigen fragment of Pneumocystis carinii (P. carinii) against P. carinii in mice.@*METHODS@#The fragment of the antigen within p55(p55-582) was cloned. Then recombinant plasmid was constructed based on the eukaryotic expression vector pcDNA3.1(+). BALB/c mice were used as experimental models to examine the immunogenicity of pcDNA3.1(+)-p55-582. ELISA and RT-PCR were used to evaluate the role of this kind of DNA vaccine.@*RESULTS@#The results of western blot indicated that the recombinant DNA[pcDNA3.1(+)-p55-582] could be expressed correctly and had antigenicity in transfected COS-7 cells. ELISA and RT-PCR showed that pcDNA3.1(+)-p55-582 elicited antibody production, stimulated lymphocyte proliferation and provided partial protection by reducing the P. carinii burden.@*CONCLUSIONS@#The data demonstrate that pcDNA3.1(+)-p55-582 might be potent vaccination that can afford the partial protection for the immunized animals.

Effect of a novel injectable hydrogel implant on ventricular remodeling in rabbits with experimental myocardial infarction / 中华心血管病杂志

<p><b>OBJECTIVE</b>To observe whether injectable hydrogel implantation could prevent adverse cardiac remodeling and preserve cardiac function in rabbits with myocardial infarction (MI).</p><p><b>METHODS</b>A novel injectable hydrogel, the copolymer MPM/alpha-CD, which self-assembled between alpha-cyclodextrin and methoxy polyethylene glycol-poly (caprolactone)-(dodecanedioic acid)-poly (caprolactone)-methoxypolyethylene glycol triblock polymer, was synthesized by chemical crosslinking and characterized by biocompatibility and biodegradability. Experimental MI was induced in male rabbits by coronary artery ligation. The MI rabbits were randomly divided into hydrogel group (200 microl MPM/alpha-CD were injected into the infarcted myocardium 7 days after MI) and control group (equal volume phosphate buffered saline myocardial injection, n = 8 each). Four weeks after MPM/alpha-CD implantation, echocardiography, histochemistry and immunohistochemistry were performed.</p><p><b>RESULTS</b>Left ventricle ejection fraction was significantly improved in the hydrogel-treated group (56.1% +/- 8.4%) than that in the control group (37.3% +/- 6.4%, P < 0.05). Histological analysis indicated that hydrogel degraded 4 weeks after hydrogel injection, and prevented scar expansion and wall thinning [(3.08 +/- 0.32) mm vs. (2.18 +/- 0.46) mm in control group, P < 0.05]. Neovasculature formation was similar between the hydrogel group [(100.8 +/- 2.4)/mm(2)] and the control [(98.5 +/- 2.9)/mm(2), P > 0.05].</p><p><b>CONCLUSION</b>MPM/alpha-CD could serve as an excellent injectable biomaterial for improves cardiac function and attenuating scar expansion and left ventricular dilation in MI rabbits.</p>

Curcumin attenuates left ventricular dysfunction and remodeling in rabbits with chronic heart failure / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the effects of Curcumin on rabbits with chronic heart failure.</p><p><b>METHODS</b>Heart failure was induced by combined aortic regurgitation and aortic stenosis in 20 New Zealand rabbits and treated with placebo (HF, n = 10) and Curcumin (Cur, 100 mgxkg(-1)xd(-1), n = 10) for 8 weeks, 10 sham operated rabbits served as controls (Con). Echocardiography was performed in all rabbits at baseline and 8 weeks later. Aortic diameter (AO), left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), left ventricular end-systolic dimension (LVDs), left ventricular end-diastolic dimension (LVDd), left ventricular posterior wall thickness (LVPW) and interventricular septum thickness (IVS) were measured. Myocardial matrix metalloproteinase (MMP)-2 and MMP-9 expressions and fibrosis were determined by immunohistochemistry and Masson staining respectively.</p><p><b>RESULTS</b>Compared to baseline, LVEF and LVFS were significantly decreased, AO, LVDs, LVDd, LVPW, and IVS significantly increased at 8 weeks after operation in HF group while these changes could be significantly attenuated in Curcumin treated rabbits. The protein expressions of MMP-2 and MMP-9 were significantly down-regulated in HF group and could be significantly up-regulated by Curcumin treatment. The increased collagen deposition in HF group was also significantly reduced by Curcumin treatment.</p><p><b>CONCLUSION</b>Curcumin attenuated left ventricular dysfunction and remodeling by up-regulating MMPs expressions and reducing myocardial fibrosis.</p>