自体与异体移植重建膝关节前交叉韧带的关键技术

目的:探索膝关节前交叉韧带重建术的各个关键技术环节,为提高前交叉韧带修复的临床效果提供理论和实践依据。方法:通过分析与总结与前交叉韧带重建相关的文献资料,包括其手术方式、移植物的选择、骨道定位、髁间窝成形、移植物预张与张力、移植物固定等,同时结合作者的工作经验旨在进一步提高前交叉韧带重建技术。结果:①手术方式选择:膝关节镜下生物材料移植重建前交叉韧带取得比以往优良的临床效果,已得到广泛认可。多数采用单束重建,部分学者正在尝试双束重建以改善移植物生物力学性能。②移植材料的选择:包括自体和同种异体材料,其中自体骨-髌腱-骨与腘绳肌腱最为常用。骨-髌腱-骨由于两端带有骨块,固定牢靠,允许早期重返运动场,颇受年轻运动员青睐。腘绳肌腱取材切口小,术后很少出现膝前痛,但其稳定性不如骨-髌腱-骨,且术后相对容易出现骨隧道扩大。异体移植物在体内结合、重塑速度较自体移植慢,但若经过严格的供体筛选、合理的组织取材、消毒和保存,而不减弱移植物强度,仍可取得与自体移植相当的效果。③骨道位置:正确的骨道定位非常重要,骨道位置太靠前会造成髁间窝撞击和伸直受限。研究表明,术中采用骨性标志定位法要比采用软组织标志定位法准确,术中摄片有助于骨道位置的正确定位。④髁间窝成形术:髁间窝成形的目的是为了便于更清楚的观察髁间窝后侧,同时也是为了避免髁间窝撞击综合征的发生,由于髁间窝过度成形会增加关节出血、疼痛、肿胀以及骨赘生长,所以一般不主张广泛的髁间窝成形,除非术中确有必要时才进行。⑤移植物预张与张力:移植物初始张力不够会导致膝关节持续松弛,而张力过高会限制关节活动并加速关节退变。目前对于最佳的初始张力尚无确切说法。⑥固定:现在已经研制出许多不同类型的固定材料。对于骨-髌腱-骨而言,界面挤压螺钉单切口重建前交叉韧带时,股骨侧靠近关节腔侧固定,胫骨侧远离关节腔侧固定,双切口技术时胫骨侧靠近关节腔侧固定,股骨侧远离关节腔侧固定。股骨侧固定完毕后,膝关节取何角度对胫骨侧进行固定尚存争议。膝关节稍屈曲状态下固定不容易发生松弛,但正常的膝关节在前后方向上是允许有一定松弛度的。有些学者认为在膝关节完全伸直状态下固定可以避免屈曲挛缩畸形的发生并允许前后方向有轻度松弛。而有些学者认为在膝关节稍微屈曲状态下固定会更紧。结论:要真正做到解剖、生物力学、生理功能全方位重建,前交叉韧带重建技术,仍需不断完善,分子生物学、基因工程和组织工程技术的发展以及计算机辅助机器人手术的开展会使前交叉韧带重建技术日臻完善。     

鸡胚胎素对小鼠红细胞数量及免疫器官质量的影响

目的:建立血虚和免疫抑制动物模型,观察鸡胚胎低温提取物对其红细胞造血以及免疫器官质量的影响。方法:实验于2001-04/2002-09在新乡医学院药物研究室完成。①实验材料:健康昆明种小鼠50只,雌雄各半。鸡胚胎素[中国发明专利公开(公告)号:CN1748713],符合研究者申报专利时提出的质量检验标准。②鸡胚胎素对血虚模型小鼠红细胞数值及血红蛋白含量的影响:取20只小鼠,随机排列表法分为鸡胚胎素组、模型对照组,10只/组,建立失血性血虚动物模型。失血后24h当红细胞数<3.2×1012L-1、血红蛋白含量<84g/L,且小鼠外观出现皮色苍白、食欲不振等现象时,代表造模成功。次日,鸡胚胎素组给予鸡胚胎素5g/(kg·d)灌胃,模型对照组给予生理盐水20mL/(kg·d)灌胃,连续14d。分别于失血前、失血后24h、末次给鸡胚胎素后2h尾部采血测定两组红细胞数量及血红蛋白含量的变化。③鸡胚胎素对免疫抑制模型小鼠免疫器官质量的影响:取30只小鼠,随机排列表法分为鸡胚胎素组、模型对照组、正常对照组,10只/组。鸡胚胎素组给予鸡胚胎素5g/(kg·d)灌胃,模型对照组和正常对照组均灌服等量生理盐水,连续14d。在第11天上午鸡胚胎素灌胃2h后,鸡胚胎素组、模型对照组腹腔注射环磷酰胺60mg/(kg·d),连续4d,复制免疫抑制动物模型。末次给予环磷酰胺2h后颈椎脱位法处死小鼠,计算胸腺、脾脏质量指数。结果:50只小鼠均进入结果分析。①失血前及失血后24h鸡胚胎素组与模型对照组的红细胞数值、血红蛋白含量基本相似(P>0.05)。末次给鸡胚胎素后2h与模型对照组比较,鸡胚胎素组红细胞数值、血红蛋白含量均明显升高(t=3.39,P<0.01;t=2.52,P<0.05)。②末次给环磷酰胺2h后与模型对照组比较,鸡胚胎素组、正常对照组的胸腺质量指数和脾脏质量指数均明显升高(t=6.62,P<0.01;t=2.47,P<0.05)。结论:鸡胚胎素灌胃对血虚小鼠具有较好的促红细胞造血功能,同时对环磷酰胺造成的免疫器官质量下降具有明显的增重作用。     

Donor levels of serum alanine aminotransferase activity and antibody to hepatitis B core antigen associated with recipient hepatitis C and non- B, non-C outcomes

BACKGROUND: Hepatitis virus(es) that are neither hepatitis B (HBV) nor hepatitis C (HCV) (non-B, non-C [NBNC]) may be transmitted by transfusion. The present study assessed donor values for alanine aminotransferase (ALT) and antibody to hepatitis B core antigen (anti- HBc) for their association with HCV and NBNC hepatitis outcomes among allogeneic blood recipients. STUDY DESIGN AND METHODS: Data on blood donors and recipients enrolled in the Transfusion- Transmitted Viruses Study in four United States cities from 1974 through 1980 were supplemented by anti-HBc testing of donors and anti-HCV evaluation of recipients. Two statistical approaches estimated the value of these indirect tests in detecting donors associated with HCV seroconversion and NBNC hepatitis in recipients. RESULTS: For HCV cases, donor ALT alone (at > or = 60 IU/L) had a sensitivity and a specificity of 30 and 96 percent, respectively, and anti-HBc alone (at > or = 60% inhibition) had a sensitivity and specificity of 53 and 86 percent, respectively. The two markers combined had a sensitivity and a specificity of 69 and 83 percent. For NBNC hepatitis cases, each measure had low sensitivity (20%) that was not improved by using both (28%) [corrected]. CONCLUSION: The indirect tests proved to be equal in sensitivity to the first-generation anti-HCV tests. The positive predictive power of these indirect tests in the 1980s was sufficient to affect HCV incidence in studies during that period. Improved anti-HCV assays, however, replaced the need for indirect tests. The sensitivity of indirect tests for NBNC hepatitis contributed little.     

Total but not resting energy expenditure is increased in infants with ventricular septal defects

OBJECTIVE: The purpose of this study was to determine the effect of left-to-right shunting on the resting energy expenditure (REE), total energy expenditure (TEE), and energy intake in a group of 3- to 5-month-old infants with moderate to large unrepaired ventricular septal defects (VSDs) compared with age-matched, healthy infants. METHODS: Eight infants with VSDs and 10 healthy controls between 3 to 5 months of age participated in the study. Indirect calorimetry was used to measure REE and the doubly-labeled water method was used to measure TEE and energy intake. An echocardiogram and anthropometric measurements were performed on all study participants. Daily urine samples were collected at home for 7 days. Samples were analyzed by isotope ratio mass spectrometry. Data were compared using analysis of variance. RESULTS: No significant differences were found in REE (VSD, 42.2 +/- 8.7 kcal/kg/d; control, 43.9 +/- 14.1 kcal/kg/d) or energy intake (VSD, 90.8 +/- 19.9 kcal/kg/d; control, 87.1 +/- 11.7 kcal/kg/d) between the groups. The percent total body water was significantly higher in the VSD infants and the percent fat mass was significantly lower. TEE was 40% higher in the VSD group (VSD, 87.6 +/- 10.8 kcal/kg/d; control, 61.9 +/- 10.3 kcal/kg/d). The difference between TEE and REE, reflecting the energy of activity, was 2.5 times greater in the VSD group. CONCLUSIONS: REE and energy intake are virtually identical between the two groups. Despite this, infants with VSDs have substantially higher TEE than age-matched healthy infants. The large difference between TEE and REE in VSD infants suggests a substantially elevated energy cost of physical activity in these infants. These results demonstrate that, although infants with VSDs may match the energy intake of healthy infants, they are unable to meet their increased energy demands, resulting in growth retardation.     

African Americans and men with severe COPD have a high prevalence of osteoporosis

Osteoporosis is a non-pulmonary manifestation whose true prevalence is uncertain in severe chronic obstructive pulmonary disease (COPD). We describe the prevalence and risk factors for osteoporosis in a large, well characterized COPD cohort. Dual energy x-ray absorptiometry of the lumbar spine and hip, full pulmonary function testing, cardiopulmonary exercise test, 6 minute walk distance and demographics were performed in 179 non-selected COPD patients. Patients were 59 +/- 7 years old, smoked 53 +/- 32 pack years, FEV(1) 26% +/- 9.8, and 45% were currently taking prednisone. Bone mineral density measurements were abnormal in 97%; 66% had dual energy X-ray absorptiometry defined osteoporosis, while 31% had osteopenia. The prevalence of osteoporosis in males versus females was 70% versus 62% (p = 0.33); both groups had similar fracture rates. The prevalence of osteoporosis in African Americans versus Caucasians was 69% versus 65% (p = 0.78). Caucasians had a significantly lower Ward's Triangle T score than African Americans (-2.52 +/- -0.96 vs. -2.16 +/- -0.91, p = 0.04). Those with bone fractures took higher doses of prednisone than those without fractures. Univariate analysis identified BMI and FVC% as predictors for osteoporosis (p = 0.03 OR 0.934 p = 0.006 OR 0.974). Multivariate analysis revealed only FVC% as a significant predictor (p = 0.006, OR 0.974). Osteoporosis is highly prevalent in severe COPD, and affects males and African Americans to a similar degree as females and Whites. Osteoporosis should be considered in severe COPD regardless of race or gender.     

Effect of lung volume reduction surgery on resting pulmonary hemodynamics in severe emphysema

RATIONALE: To determine the effect of medical treatment versus lung volume reduction surgery (LVRS) on pulmonary hemodynamics. METHODS: Three clinical centers of the National Emphysema Treatment Trial (NETT) screened patients for additional inclusion into a cardiovascular (CV) substudy. Demographics were determined, and lung function testing, six-minute-walk distance, and maximum cardiopulmonary exercise testing were done at baseline and 6 months after medical therapy or LVRS. CV substudy patients underwent right heart catheterization at rest prerandomization (baseline) and 6 months after treatment. MEASUREMENTS AND MAIN RESULTS: A total of 110 of the 163 patients evaluated for the CV substudy were randomized in NETT (53 were ineligible), 54 to medical treatment and 56 to LVRS. Fifty-five of these patients had both baseline and repeat right heart catheterization 6 months postrandomization. Baseline demographics and lung function data revealed CV substudy patients to be similar to the remaining 1,163 randomized NETT patients in terms of age, sex, FEV(1), residual volume, diffusion capacity of carbon monoxide, Pa(O(2)), Pa(CO(2)), and six-minute-walk distance. CV substudy patients had moderate pulmonary hypertension at rest (Ppa, 24.8 +/- 4.9 mm Hg); baseline hemodynamic measurements were similar across groups. Changes from baseline pressures to 6 months post-treatment were similar across treatment groups, except for a smaller change in pulmonary capillary wedge pressure at end-expiration post-LVRS compared with medical treatment (-1.8 vs. 3.5 mm Hg, p = 0.04). CONCLUSIONS: In comparison to medical therapy, LVRS was not associated with an increase in pulmonary artery pressures.     

Alternatives to lung transplantation: lung volume reduction for COPD

Emphysema is disabling and progressive and hallmarked by decreased exercise tolerance and impaired quality of life. Surgical interventions that reduce lung volume have been the focus of multiple interventions for decades; however, until recently, limited evidence has documented their effectiveness. Lung volume reduction surgery (LVRS) underwent rigorous study in the National Emphysema Treatment Trial (NETT), which demonstrated its short-term and long-term effectiveness, associated morbidity and mortality, and the essential factors that predict LVRS success or failure. This article summarizes the major results of the NETT and briefly reviews newer bronchoscopic lung volume reduction techniques that show promise as alternative treatments for select patients with COPD undergoing consideration for lung transplantation.     

Cardiac disease in chronic obstructive pulmonary disease

The cardiac manifestations of chronic obstructive pulmonary disease (COPD) are numerous. Impairments of right ventricular dysfunction and pulmonary vascular disease are well known to complicate the clinical course of COPD and correlate inversely with survival. The pathogenesis of pulmonary vascular disease in COPD is likely multifactorial and related to alterations in gas exchange and vascular biology, as well as structural changes of the pulmonary vasculature and mechanical factors. Several modalities currently exist for the assessment of pulmonary vascular disease in COPD, but right heart catheterization remains the gold standard. Although no specific therapy other than oxygen has been generally accepted for the treatment of pulmonary hypertension in this population, there has been renewed interest in specific pulmonary vasodilators. The coexistence of COPD and coronary artery disease occurs frequently. This association is likely related to shared risk factors as well as similar pathogenic mechanisms, such as systemic inflammation. Management strategies for the care of patients with COPD and coronary artery disease are similar to those without COPD, but care must be given to address their respiratory limitations. Arrhythmias occur frequently in patients with COPD, but are rarely fatal and can generally be treated medically. Use of beta-blockers in the management of cardiac disease, while a theoretical concern in patients with increased airway resistance, is generally safe with the use of cardioselective agents.     

Effects of lung volume reduction surgery on sleep quality and nocturnal gas exchange in patients with severe emphysema

STUDY OBJECTIVES: We hypothesized that associated with improvements in respiratory mechanics, lung volume reduction surgery (LVRS) would result in an improvement in both sleep quality and nocturnal oxygenation in patients with severe emphysema. DESIGN: Prospective randomized controlled trial. SETTING: University hospital. PATIENTS: Sixteen patients (10 men, 63 +/- 6 years [+/- SD]) with severe airflow limitation (FEV(1), 28 +/- 10% predicted) and hyperinflation (total lung capacity, 123 +/- 14% predicted) who were part of the National Emphysema Treatment Trial.Interventions and measurements: Patients completed 6 to 10 weeks of outpatient pulmonary rehabilitation. Spirometry, measurement of lung volumes, arterial blood gas analysis, and polysomnography were performed prior to randomization and again 6 months after therapy. Ten patients underwent LVRS and optimal medical therapy, while 6 patients received optimal medical therapy only. RESULTS: Total sleep time and sleep efficiency improved following LVRS (from 184 +/- 111 to 272 +/- 126 min [p = 0.007], and from 45 +/- 26 to 61 +/- 26% [p = 0.01], respectively), while there was no change with medical therapy alone (236 +/- 75 to 211 +/- 125 min [p = 0.8], and from 60 +/- 18 to 52 +/- 17% [p = 0.5], respectively). The mean and lowest oxygen saturation during the night improved with LVRS (from 90 +/- 7 to 93 +/- 4% [p = 0.05], and from 83 +/- 10 to 86 +/- 10% [p = 0.03], respectively), while no change was noted in the medical therapy group (from 91 +/- 5 to 91 +/- 5 [p = 1.0], and from 84 +/- 5 to 82 +/- 6% [p = 0.3], respectively). There was a correlation between the change in FEV(1) and change in the lowest oxygen saturation during the night (r = 0.6, p = 0.02). In addition, there was an inverse correlation between the change in the lowest oxygen saturation during the night and the change in residual volume (- r = 0.5, p = 0.04) and functional residual capacity (- r = 0.6, p = 0.03). CONCLUSION: In patients with severe emphysema, LVRS, but not continued optimal medical therapy, results in improved sleep quality and nocturnal oxygenation. Improvements in nocturnal oxygenation correlate with improved airflow and a decrease in hyperinflation and air trapping.