Physical activity and incident clinical knee osteoarthritis in older adults

Objective

To study the relationship between 4 components of physical activity and the 12‐year incidence of clinical knee osteoarthritis (OA) among older adults.

Methods

Longitudinal data from 1,678 men and women, ages 55–85 years, were collected in the Longitudinal Aging Study Amsterdam. Incident clinical knee OA was defined by an algorithm using self‐report and general practitioner data. Physical activity was assessed by a validated questionnaire from which 4 physical activity component scores were created: muscle strength, intensity, mechanical strain, and turning actions. Cox proportional hazards models were conducted to examine the relationship between these scores and incident knee OA and reported as hazard ratios (HRs) with 95% confidence intervals (95% CIs).

Results

During 12 years of followup, 463 respondents (28%) developed clinical knee OA. A high mechanical strain score (HR 1.43, 95% CI 1.15–1.77) and a low muscle strength score (HR 1.30, 95% CI 1.01–1.68) were associated with an increased risk of knee OA after adjustment for age, sex, region of living, education, lifetime physical work demands, lifetime general physical activity, body mass index, current total physical activity level, and depression. No association was observed in the intensity and turning actions components. The results were similar for men and women, and for obese and nonobese respondents.

Conclusion

Older adults who perform low muscle strength activities or activities causing high mechanical strain had an increased risk of clinical knee OA. These results suggest that specific components of physical activity may influence the development of knee OA.     

Trans-fontanellar Doppler sonography of the intracranial veins in infants. Part II--pathology

Colour coded Doppler sonography can be very helpful for the diagnosis of haemorrhagic infarction of the brain parenchyma, cerebral venous thrombosis and arterio-venous malformations of the brain. Intracranial haemorrhages into the brain parenchyma are caused by the compression of the subependymal and terminal veins which impede the venous drainage from the white matter. Haemorrhage of the basal ganglia is highly suspicious of cerebral venous thrombosis especially of the deep venous drainage. Unilateral occlusion of only one internal cerebral vein causes unilateral haemorrhage, bilateral thrombosis of both internal cerebral veins as well as occlusion of the great vein of Galens or the straight sinus causes bilateral haemorrhage of the basal ganglia as well as ventricular haemorrhage and haemorrhagic infarction of the white matter. The most common arterio-venous malformation of the brain is AV-malformation of Galens's vein. Sonographically, a pulsating cystic structure behind the 3rd ventricle can be shown. Colour coded Doppler sonography demonstrates the vascular nature of the cyst. Doppler sonography can show the feeding arteries, most frequently the posterior choroidal arteries and the venous drainage by the straight sinus.     

Analysis of megakaryocyte ploidy in rat bone marrow cultures

Megakaryocytes undergo changes in ploidy in vivo in response to varying demands for platelets. Attempts to study the putative factor(s) regulating these ploidy changes have been frustrated by the lack of an appropriate in vitro model of megakaryocyte endomitosis. This report describes a culture system in which rat bone marrow is depleted of identifiable megakaryocytes and enriched in their precursor cells. Morphologically identifiable megakaryocytes appear when the depleted marrow is cultured in vitro. The total number of nucleated cells, as well as the number of megakaryocytes and their ploidy distribution, are quantitated very precisely by flow cytometry. Although the total number of nucleated cells declines by 35% to 40% over 3 days in culture, the number of megakaryocytes rises 10-fold. The number of nucleated cells, the number of megakaryocytes, and the extent of megakaryocyte ploidization behave as independent variables in culture and are dependent on the culture conditions. The addition of recombinant erythropoietin promotes a rise in the number of megakaryocytes and a shift in ploidy to higher values while recombinant murine granulocyte- macrophage colony stimulating factor is without effect on the cultured megakaryocytes. This in vitro system may provide a means to study those factors that affect megakaryocyte growth and ploidization.     

Recovery of normal autologous myelopoiesis after graft rejection following allogeneic bone marrow transplant for agnogenic myeloid metaplasia

Allogeneic hematopoietic transplantation is the only currently available therapy that has the potential to cure agnogenic myeloid metaplasia (AMM) or primary myelofibrosis (PMF). Amelioration of fibrosis and eradication of the abnormal clone is thought to occur through the repopulation of marrow by donor-derived hematopoiesis and graft-vs.-host reaction leading to graft vs. tumor effect. We report here a 50-year-old female with AMM/PMF, conditioned with busulfan and cyclophosphamide, who rejected a single locus (HLA-B) mismatched bone marrow transplant from her daughter, but recovered normal autologous hematopoiesis with disappearance of marrow fibrosis and extramedullary hematopoiesis. Variable number tandem repeats (VNTR) analysis showed a gradual loss of donor-derived hematopoietic cells with recovery of autologous hematopoiesis. This case therefore illustrates that eradication of AMM/PMF in this patient with myeloablative chemotherapy combined with a transient allogeneic effect was sufficient to suppress the abnormal stem cell clone associated with AMM/PMF with subsequent cure.     

碱性成纤维细胞生长因子对环磷酰胺致小鼠睾丸损伤修复的促进作用

目的:观察碱性成纤维细胞生长因子对环磷酰胺致小鼠睾丸损伤的促修复作用。方法:实验于2004-10-01/2005-01-05在泰山医学院形态学实验室完成。选用清洁级昆明种雄性小白鼠50只。以随机数字表法分为5组,即正常对照组、模型对照组、碱性成纤维细胞生长因子400,800,1200 IU/(kg·d)剂量组,每组10只。①建立环磷酰胺致睾丸损伤小鼠模型:腹腔注射5mg/(kg·d)环磷酰胺,正常对照组给予等体积的生理盐水,连续36 d。②给予碱性成纤维细胞生长因子治疗:从第37 d开始,对碱性成纤维细胞生长因子不同剂量组分别给予碱性成纤维细胞生长因子400,800,1200 IU/(kg·d)腹腔注射,连续36 d,模型对照组和正常对照组给予等体积的生理盐水。③末次给药后24h,麻醉下颈椎脱臼法处死小鼠,剥离双侧附睾尾,剪碎,过滤,制精子悬液。400倍光镜观察,检测精子数量、存活率、畸形率、精子活动力。睾丸组织行电镜、光镜观察。SP法检测睾丸组织增殖细胞核抗原的表达。结果:进入结果分析小鼠50只。①碱性成纤维细胞生长因子400,800,1200 IU/(kg·d)剂量组精子数量、存活率、活动力均高于模型对照组,差异有非常显著性意义(P<0.01);精子畸形率低于模型对照组,差异有显著性意义(P<0.01);且上述指标碱性成纤维细胞生长因子800,1200 IU/(kg·d)剂量组与正常对照组比较差异无统计学意义[(65.37±1.39)×108/g,(7.03±1.94)%,(90.90±2.16)%,(80.95±1.96)%,P>0.05]。②碱性成纤维细胞生长因子400,800,1200 IU/(kg·d)剂量组睾丸组织结构、超微结构均较模型对照组有明显恢复,其中碱性成纤维细胞生长因子800,1200 IU/(kg·d)剂量组曲细精管管腔大小一致,结构规则,生精上皮层次增多,排列整齐,管腔内有较多精子,基本恢复正常。③碱性成纤维细胞生长因子400,800,1200 IU/(kg·d)剂量组增殖细胞核抗原阳性细胞数高于模型对照组[(35.9±6.2),(71.1±9.22),(71.3±10.4),(20.4±6.36)个,P<0.01],且800,1200 IU/(kg·d)剂量组与正常对照组相比,差异无统计学意义(P>0.05)。结论:碱性成纤维细胞生长因子对环磷酰胺致睾丸损伤有明显的促修复作用,可能与外源性碱性成纤维细胞生长因子促进生精细胞的分裂增殖等机制有关。     

影像诊断结构化报告的临床应用优势

目的:观察基于医学影像存储与传输系统的放射结构化诊断报告系统的应用效果。方法:实验于2006-03/04在广东省第二人民医院进行。①选择高、中、初级职称的影像诊断医师各3名,均有3年以上应用计算机处理影像诊断报告的经历,按高、中、初级职称配搭方式,将上述9名影像诊断医师随机分为A,B,C3个组,随机选择诊断报告方式,A组为人工书写;B组为计算机报告录入系统;C组为结构化报告系统。②选择正常头颅(共90份)和肝脏病变(63份)CT扫描片,由以上3组分别应用各自的方式进行诊断报告,记录各组每位医师完成的时间。③将上述报告归档后,随机选择50份,由1名初级职称医师按CT号或姓名分别在以上3组中查询已经归档的相应CT资料,记录各次的时间。④应用PEMS 3.1 for windows软件包进行统计处理。结果:①正常头部报告及肝脏病变报告完成时间统计显示3组之间差异均有显著性(正常头部报告:H=238.8196,Hc=238.8356,χ2=238.8356,V=2,P=0.0000;肝癌报告:H=144.7569,Hc=144.7685,χ2=144.7685,V=2,P=0.0000),其中结构化报告组最短,手写报告组最长。②不同职称人员在报告完成时间上差异并无显著性(正常报告:F=0.0413,P=0.9596;异常报告:F=0.0073,P=0.9927)。③归档报告查询时间上3组之间差异均有显著性(H=125.1017,Hc=125.1396,χ2=125.1396,V=2,P=0.0000),以结构化查询时间最短,人工查询报告时间最长。结论:结构化报告缩短报告时间与周期,提高了影像诊断工作效率。     

应用自制异种骨椎间融合器行颈椎前路椎体间融合的生物力学评价：即刻稳定效果及自身强度

目的:自体髂骨移植与钛合金Cage在颈椎椎体间融合手术中的应用存在较多并发症,为弥补其不足,自行研制出一种并发症少的生物型融合器,通过在成人新鲜颈椎标本上模拟临床术式放置异种骨椎间融合器,验证其置入后的稳定性及自身强度。方法:实验于2005-06/2006-07在吉林大学机械科学与工程学院力学实验室完成。取16具新鲜成年男性C1~7颈椎标本,分为3组:①正常组:完整C1~7。②对照1组:模拟前路间盘C5~6摘除置1枚融合器。③对照2组:模拟前路间盘C5~6、C6~7摘除置2枚融合器。3组均进行稳定性实验和黏弹性实验,观察在不同应力下前屈、后伸、垂直压缩、扭转时位移距离,颈椎移位时融合器最大拔出力,脊柱压缩应力与时间,脊柱施加应力后时间与应变量。结果:①在颈椎前屈及后伸状态下对照1,2组较正常组位移小但差异不显著(P>0.05)。②垂直压缩实验结果显示在最大载荷为500N力作用下对照1,2组位移较正常组小,但差异不显著(P>0.05)。③颈椎移位时拔出力实验结果表明,植入椎间的融合器最大拔出力为1.85kN。④在200N·cm扭矩作用下,对照1,2组扭转角较正常组小,但差异不显著(P>0.05)。⑤对照1,2组7200s,应力松弛量和蠕变量小于正常组,但差异不显著(P>0.05)。结论:自制异种骨椎间融合器具有足够的支撑、抗滑、维持或增加椎间隙高度的功能,符合生物力学及临床要求。     

Responsiveness of the index of mobility limitation: comparison with gait speed alone in the longitudinal aging study amsterdam

BACKGROUND: Interpreting self-reported disability differences between diverse older populations is complicated by differences in attitudes and environment. We have previously reported on the index of mobility-related limitation tests (MOBLI), and shown that it predicts mortality over 4 years. In this article, we examine whether the index is responsive to changes in self-reported mobility disability. METHODS: Data on gait speed, time to complete 5 chair stands, and peak expiratory flow rate, with self-reported difficulty walking for 5 minutes, were available from the baseline and two 3-year follow-ups in the Longitudinal Aging Study Amsterdam. Analysis used data on changes in the index (or walking speed alone) and corresponding change over 3 years in self-reported difficulty or inability with a medium-distance walk. RESULTS: During all follow-ups, groups reporting deterioration in functioning had relatively larger changes in gait speed and MOBLI score than did the "no deterioration" groups. In comparative analyses of responsiveness, the MOBLI score had a larger responsiveness index, higher odds ratios, and larger receiving operating characteristic area than gait speed alone. CONCLUSIONS: The MOBLI index of mobility-related physical limitation tests is responsive to changes in self-reported mobility disability over two 3-year periods, and performs better than gait speed alone. This property is strongly supportive of its validity for epidemiological comparison of older populations across countries or over longer periods of time.     

Endoscopic sclerotherapy compared with no specific treatment for the primary prevention of bleeding from esophageal varices. A randomized controlled multicentre trial [ISRCTN03215899]

Background

Since esophageal variceal bleeding is associated with a high mortality rate, prevention of bleeding might be expected to result in improved survival. The first trials to evaluate prophylactic sclerotherapy found a marked beneficial effect of prophylactic treatment. These results, however, were not generally accepted because of methodological aspects and because the reported incidence of bleeding in control subjects was considered unusually high. The objective of this study was to compare endoscopic sclerotherapy (ES) with nonactive treatment for the primary prophylaxis of esophageal variceal bleeding in patients with cirrhosis.

Methods

166 patients with esophageal varices grade II, III of IV according to Paquet's classification, with evidence of active or progressive liver disease and without prior variceal bleeding, were randomized to groups receiving ES (n = 84) or no specific treatment (n = 82). Primary end-points were incidence of bleeding and mortality; secondary end-points were complications and costs.

Results

During a mean follow-up of 32 months variceal bleeding occurred in 25% of the patients of the ES group and in 28% of the control group. The incidence of variceal bleeding for the ES and control group was 16% and 16% at 1 year and 33% and 29% at 3 years, respectively. The 1-year survival rate was 87% for the ES group and 84% for the control group; the 3-year survival rate was 62% for each group. In the ES group one death occurred as a direct consequence of variceal bleeding compared to 9 in the other group (p = 0.01, log-rank test). Complications were comparable for the two groups. Health care costs for patients assigned to ES were estimated to be higher. Meta-analysis of a large number of trials showed that the effect of prophylactic sclerotherapy is significantly related to the baseline bleeding risk.

Conclusion

In the present trial, prophylactic sclerotherapy did not reduce the incidence of bleeding from varices in patients with liver cirrhosis and a low to moderate bleeding risk. Although sclerotherapy lowered mortality attributable to variceal bleeding, overall survival was not affected. The effect of prophylactic sclerotherapy seems dependent on the underlying bleeding risk. A beneficial effect can only be expected for patients with a high risk for bleeding.     

Physical activity as a determinant of change in mobility performance: the Longitudinal Aging Study Amsterdam

OBJECTIVES: This study examined the association of (change in) physical activity and decline in mobility performance in older men and women. DESIGN: A 3-year prospective study using data of the Longitudinal Aging Study. SETTING: Netherlands. PARTICIPANTS: Two thousand one hundred nine men and women aged 55 to 85. MEASUREMENTS: Total physical activity (expressed as hours per day and kilocalories per day) and sports participation were measured using a validated, interviewer-administered questionnaire. Mobility performance was assessed using two timed tests: 6-meter walk and repeated chair stands. RESULTS: Mobility performance declined for 45.6% of the sample. At baseline, the mean time +/- standard deviation spent on total physical activity was 3.0 +/- 2.1 h/d or 719 +/- 543 kcal/d, and 56.6% of the sample participated in sports. Sports participation and a higher level of total physical activity, walking, or household activity were associated with a smaller mobility decline. After 3 years, total physical activity declined, and only 53.4% of those reporting sports at baseline continued doing so. Continuation of physical activity over time was associated with the smallest decline in mobility. The observed associations were similar for those with and without chronic disease (P> 0.3). The conclusions did not change after adjustment for potential confounders, including demographic and lifestyle variables, depression, and cognitive status. CONCLUSIONS: Physical activity, and especially a regularly active lifestyle, may slow the decline in mobility performance. A beneficial effect was observed for sports and nonsports activities, independent of the presence of chronic disease.