Objective To study the effects of different posterior slope installations of unicompartmental knee arthroplasty(UKA)prostheses on the loading and motion of the knee joint and insert wear.Methods A combined approach involving the UKA musculoskeletal multibody dynamic,finite element,and wear prediction models was used to investigate the effects of five different posterior slope installation positions of the UKA prosthesis on the postoperative knee joint force and motion,insert contact stress,linear wear depth,and wear volume.Results At a 0° posterior slope,the maximum von Mises stress of the insert was 24.84 MPa,maximum contact stress was 47.61 MPa,and volumetric wear after 5 million cycles(MC)was 47.29 mm3.As the posterior slope angle of the UKA prosthesis increased,the internal rotation and posterior translation during the gait cycle increased,the medial joint force during the swing phase increased,the von Mises and contact stresses of the insert after 5 MC decreased significantly,and the wear area,maximum linear wear depth,and volumetric wear volume of the insert were consequently reduced.Compared to the 0° posterior slope,the linear wear depths of the insert at the 3°,5°,and 7° posterior slopes decreased by 17.8％,19.2％,and 20.6％,respectively.The volumetric wear volumes of the inserts decreased by 24.5％,30.9％,and 34.3％,respectively.Conclusions Installing a UKA prosthesis with a posterior slope exceeding 3° significantly increases internal rotation and posterior translation during the gait cycle,further reducing the articular volumetric wear of the polyethylene insert.

The clinical performance and failure issues are significantly influenced by prosthetic malposition in unicompartmental knee arthroplasty (UKA). Uncertainty exists about the impact of the prosthetic joint line height in UKA on tibial insert wear. In this study, we combined the UKA musculoskeletal multibody dynamics model, finite element model and wear model to investigate the effects of seven joint line height cases of fixed UKA implant on postoperative insert contact mechanics, cumulative sliding distance, linear wear depth and volumetric wear. As the elevation of the joint line height in UKA, the medial contact force and the joint anterior-posterior translation during swing phase were increased, and further the maximum von Mises stress, contact stress, linear wear depth, cumulative sliding distance, and the volumetric wear also were increased. Furthermore, the wear area of the insert gradually shifted from the middle region to the rear. Compared to 0 mm joint line height, the maximum linear wear depth and volumetric wear were decreased by 7.9% and 6.8% at -2 mm joint line height, and by 23.7% and 20.6% at -6 mm joint line height, the maximum linear wear depth and volumetric wear increased by 10.7% and 5.9% at +2 mm joint line height, and by 24.1% and 35.7% at +6 mm joint line height, respectively. UKA prosthetic joint line installation errors can significantly affect the wear life of the polyethylene inserted articular surfaces. Therefore, it is conservatively recommended that clinicians limit intraoperative UKA joint line height errors to -2-+2 mm.
Humans ; Arthroplasty, Replacement, Knee ; Knee Joint ; Knee Prosthesis ; Mechanical Phenomena ; Polyethylene ; Osteoarthritis, Knee/surgery* ; Tibia/surgery* ; Biomechanical Phenomena

Objective: Through statistical analysis of drug resistance and homology of Acinetobacter baumannii in geriatric department of our hospital, we can provide evidence for clinical experience in antibiotics use and nosocomial infection control. Methods: The drug resistance of Acinetobacter baumannii isolated from the elderly rehabilitation department in Ningbo Kangning Hospital from January 2017 to December 2018 was analyzed by retrospective analysis.The homology of Acinetobacter baumannii isolated from clinical isolates was detected by PCR ERIC-PCR method and agarose gel electrophoresis method. Results: The resistance rates of Acinetobacter baumannii to ciprofloxacin and levofloxacin were 41.6% and 35.4%, respectively.The resistance rates to cefepime, ceftriaxone and ceftazidime were 40.3%, 38.9% and 36.7%, respectively.The resistance rate to imipenem was 38.9%, and the sensitivity rates to cefoperazone/sulbactam, gentamicin and tobramycin were all over 70%.A total of 226 strains of Acinetobacter baumannii were genotyped by ERIC-PCR.They were mainly classified into A, B, C, D and E 5 types.Among them, 116 strains were type A, 68 strains were type B, 26 strains were type C, 8 strains were type D and E. Conclusion The resistance rate of Acinetobacter baumannii to some antibiotics in geriatric rehabilitation department is still at a high level, so we should continue to strengthen the rational use of antibiotics; at the same time, the strains are highly homologous, and there is likely to be clonal transmission in the department, so we should take more effective measures to prevent and control its transmission in hospital.

Objective To explore the effect of selective beta-1 adrenoreceptor blocker on exercise tolerance in patients with hyperten-sion. Methods From May, 2015 to May, 2016, 72 patients with hypertension were divided into two groups, according to whether taking the selective beta-1 receptor blocker. Group A (n=35) took the selective beta-1 receptor blocker two weeks before cardiopulmonary exercise, while group B (n=37) did not take anything at the same time. The exercise tolerance was compared between two groups. Results The maxi-mal systolic blood pressure, peak heart rate, one-minute heart rate after exercise (HR1) and rate-pressure product were lower in group A than in group B (t>2.012, P<0.05), however, the recovery value of HR1 was higher in group A than in group B (t=2.100, P<0.05). There was no difference in both peak power and peak oxygen uptake between two groups (t<0.689, P>0.05). Conclusion The selective beta-1 adrenore-ceptor blocker could reduce myocardial oxygen consumption, and improve vagus nerve activity, but did not reduce exercise tolerance in pa-tients with hypertension.

[ ABSTRACT] AIM:To study the effect of livin gene-modified bone marrow mesenchymal stem cells ( BM-MSCs) transplantation on the cardiac function following acute myocardial infarction in a rat model and the expression of livin , caspase-3, caspase-7 and caspase-9 in the livin gene-modified BM-MSCs.METHODS: The MSCs were obtained by the whole bone marrow culture method , and the apoptosis of the MSCs after infection with adenovirus vector carrying enhanced green fluorescent protein ( EGFP) gene and livin recombinant vector ( rAd-livin) were detected by flow cytometry .The ex-pression of livin, caspase-3, caspase-7 and caspase-9 was detected by Western blot .After permanent left anterior descend-ing artery occlusion , the rats were randomized to receive intramyocardial injection of DMEM without cells ( vehicle group ) , or containing MSCs ( MSCs group ) , MSCs ( EGFP ) ( rAd-control/MSCs group ) or MSCs ( livin ) ( rAd-livin/MSCs group).Left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), the maximum in-creased rate of left ventricular pressure ( -dp/dtmax ) and the maximum decline rate of left ventricular pressure ( +dp/dtmax ) were recorded for evaluating the cardiac functions .RESULTS: The apoptosis of rAd-livin/MSCs was significantly decreased as compared with MSCs and rAd-control/MSCs (P<0.05).Meanwhile, the expression of caspase-3, caspase-7 and caspase-9 was significantly downregulated as compared with the other 2 groups ( P<0.05 ) .The cardiac function in rAd-livin/MSCs group was significantly improved as compared with DMEM group , and those in the other 2 groups got the similar results, but the function in rAd-livin/MSCs group was better improved .Meanwhile, the number of surviving cells in rAd-livin/MSCs group was significantly improved as compared with the other 2 groups .CONCLUSION:The apoptosis of MSCs is decreased after rAd-livin transfection, and the expression of caspase-3, caspase-7 and caspase-9 is also significant-ly downregulated while the expression of livin is significantly upregulated .Transplantation of livin-modified BM-MSCs by lentiviral vector results in better prognosis for treating myocardial infarction by enhancing cell survival .

Objective To explore the expression of nitric oxide synthases including neuronal nitric oxide synthases(nNOS), inducible nitric oxide synthases(iNOS), endothelial nitric oxide synthases (eNOS) in neurogenic bladder tissues, and analyze it's producing feature and significance. Methods There were 30 cases with neurogenic bladder(18 males, 12 females). The average age was 6.3±3.1 years. All patients appeared with myelodysplasia, urinary and fecal incontinence in different degree. Twenty-six cases were manifested with hyperreflexia bladders, and all patients were treated with surgical procedures. During operation, collected bladder tissue samples including tissues of apex vesicae and tissues of bladder neck, and all tissues were enveloped with mineral wax. All tissues were detected for nNOS, iNOS, and eNOS respectively in tissues of apex vesicae and tissues of bladder neck,and with normal bladder tissues as control group (bladder tissues of hypospadia, 10 cases), and according to clinical features, to explore the expression of NOS, and to analyze the relationship among them. Results In normal apex vesicae tissues, all cases stained with nNOS, and distributed among bundles of smooth muscles, and surface of smooth muscles and interstitial tissue, histochemica;score (HS) 2.8-4.0 and 1.2-2.7. There were no stained cells in bladder tissues of iNOS, and HS was very low, HS:0-0. 4 and 0-0.1 ;eNOS mainly distributed in interstitial tissues in rarefaction manners, and mainly in vascular endothelial cell (VEC), and smooth muscles had no stainings the most expression among them was nNOS, and mainly distributed in bladder neck tissues. In neurogenic bladder tissues, the main expression of NOS type was iNOS, and nNOS decreased significantly. eNOS mainly expressed in VEC among interstitial tissues, and had no staining in smooth muscle cells and collagenoblast and rarefaction of microvessel in bladder tissues, and microvessel density decreased significantly than normal bladder tissues. Microvessal density(MVD) in bladder tisssus (6. 8± 3.2/100per square) was less than that in normal tissues (16.7±6.3/100 per square). Conclusions In normal bladder tissues, nNOS mainly distributes in bladder neck and urethra, and nitric oxide mainly derives from nNOS. Much more matrix fibers, fewer nitrogenergic nerves, and less nNOS expression are seen in neurogenic bladder interstitial tissue. There are more iNOS expressions in bladder tissues,and NO is mainly derived from iNOS, and it may play an important role in pathological bladder tissues, especially in fibrosis of bladder wall. eNOS may be considered as angiopoietic labeling, and may evaluate the blood supply of bladder.

ObjectiveTo investigate the relationship between high-sensitivity C reactive protein （hs-CRP） and oxygen uptake efficiency slope (OUES) in patents with cardiovascular disease. MethodsExercise tests, following a symptom-limited standard Bruce protocol with simultaneous respiratory gas-exchange measurements, were performed on a treadmill in 17 post-PCI patients, 21 stable angina pectoris and 24 patients with essential hypertension (EH). The oxygen uptake (VO2), minute ventilation (VE) were determined. The OUES was derived from the relation between VO2 (ml/min) and VE (L/min) during incremental exercise and was determined by VO2=a×lgVE+b, where a = OUES. The OUES was calculated from data of the first 75% (OUES75) and 100% (OUES100) of exercise duration. The serum hs-CRP was measured by immunoassays, and the left ventricular ejection fraction (LVEF) was measured with echocardiography. ResultsOUES75 （r=-0.506,P＜0.001）, OUES100 （r=-0.567,P＜0.001） and LVEF （r=-0.286,P＜0.01） were correlated with lg(hs-CRP). In stepwise multivariable linear regression models, lg(hs-CRP) （β=-0.374，P=0.006）, body height （β=-1.854，P=0.036）, body weight （β=-5.033，P=0.034）were independent risk factors of lower OUES75. lg(hs-CRP) （β=-0.396，P=0.003）, body height （β=-2.157，P=0.013）, body weight （β=-5.912，P=0.011） were independent risk factors of lower OUES100. ConclusionThe serum leveles of hs-CRP may be the useful marker that reflecting cardiopulmonary functional reserve and left ventricular function.

ObjectiveTo explore the arrhythmia happened in patients with cervical spinal cord injury (CSCI). Methods61 patients with CSCI were retrospectively analyzed. ResultsThe overall incidence of sinus bradycardia was 26.2%, which was higher in the cases within 3 months (52.4%) than over (12.5%); and was higher in cases injured the cord above C5（46.2%）than lower (C6-8,11.4%). ConclusionThe risk of arrhythmia is still high in chronic phase, which still need to monitor.

Objective To investigate the relationship between daily physical activities determined by walking-steps and the obesity indices including body weight，Body Mass Index (BMI)，waist and hip circumference and their ratio in adults. Methods 125 individuals who participated in routine physical examinations of health were measured with body weight, BMI, waist and hip circumference/ratio, daily physical activities determined by walking steps. Results For males, daily physical activities correlated negatively with body weight （r=-0.397，P＜0.01）, BMI （r=-0.499，P＜0.01）, waist circumference （r=-0.490, P＜0.01） and the ratio of waist vs. hip circumference （r=-0.478，P＜0.01）, whereas body weight（r=-0.342，P＜0.01）, BMI （r=-0.249，P＜0.05）, and hip circumference （r=-0.303，P＜0.05） for females. Daily walking-steps were significantly different among the groups of normal weight (11491±6100) steps/d, overweight (9314±5722) steps/d, and obesity (6141±2985) steps/d (P＜0.01). Conclusion Daily physical activities determined by walking steps correlated significantly with obesity indices.

Objective To investigate the relationship between daily walking-steps and serum lipids.Methods 120 individuals who participated in routine physical examinations of health were investigated, objective measurements included triacylglycerol (TG), total cholesterol (TC), low density lipoprotein (LDL) and high density lipoprotein (HDL), and daily walking-steps were determined by pedometer.Results The daily walking-steps were correlated negatively to TG ( r=-0.351, P＜0.01), and positively to HDL ( r=0.284, P＜0.05) for male after adjustment for age.Conclusion Daily walking-steps determined by pedometer are correlated negatively to TG levels, and positively to HDL levels for male. No correlations are found between daily walking-steps and levels of TC, LDL for male. No correlations are found between daily walking-steps and serum lipids for female.