Improved anchorage in osteoporotic vertebrae with new implant designs.

The goal of our study was to evaluate two newly developed implant designs and their behavior in terms of subsidence in lumbar vertebral bodies under cyclic loading. The new implants were evaluated in two different configurations (two small prototypes vs. one large prototype with similar load-bearing area) in comparison to a conventional screw-based implant (MACS TL). A pool of 13 spines with a total of 65 vertebrae was used to establish five testing groups of similar bone mineral density (BMD) distribution with eight lumbar vertebrae each. In additional to BMD assessment via dual-energy X-ray absorptiometry, cancellous BMD and structural parameters were determined using a new generation in vivo 3D-pQCT. The specimens were loaded sinusoidally in force control at 1 Hz for 1000 cycles at three load levels (100, 200, and 400 N). A survival analysis using the number of cycles until failure (Cox regression with covariates) was applied to reveal differences between implant groups. All new prototype configurations except the large cylinder survived significantly longer than the control group. The number of cycles until failure was significantly correlated with the structural parameter Tb.Sp. and similarly with the cancellous BMD for three of five implants. In both large prototypes the cycle number until failure significantly correlated with the preoperative distance to the upper endplates. Although the direct relationship between bone structure or density and mechanical breakage behavior cannot be conclusively proven, all the prototypes adapted for poor bone structure performed better than the comparable conventional implant.     

F-19 MR imaging of glucose metabolism in the rabbit

Noninvasive metabolic magnetic resonance (MR) imaging reflecting glucose metabolism in the aldose-reductase-sorbitol (ARS) pathway was performed in the rabbit head; after administration of the fluorinated glucose analogue 3-fluoro-3-deoxy-D-glucose (3FD-glucose), fluorine-19 images were generated. Images of 3FD-glucose showed significant 3FD-glucose uptake by adipose tissue, indicating its buffering effects in case of excess loads of glucose. Images of 3-fluoro-3-deoxy-D-sorbitol (3FD-sorbitol) demonstrated the spatial distribution of aldose reductase activities and significant sorbitol accumulation in the lens. Images of 3-fluoro-3-deoxy-D-fructose (3FD-fructose) showed preferential uptake of fructose by muscle tissue. The extremely low toxicity of 3FD-glucose indicates promise for its clinical application in metabolic imaging.     

大鼠移植心脏组织中血小板衍生生长因子A mRNA表达及雷帕霉素的干预效应

目的:血小板衍生生长因子在平滑肌细胞的表型转化过程中起重要作用。观察大鼠移植心脏组织中血小板衍生生长因子AmRNA表达的变化及雷帕霉素的干预效应。方法:实验于2005-10/2006-01在中南大学湘雅二医院胸心外科实验室完成。将60只SD大鼠、24只Wistar大鼠按随机数字表法分为3组:①同系移植组:供、受体各12只,均为SD大鼠。②异系移植组:供体为Wistar大鼠(n=24),受体为SD大鼠(n=24),受体大鼠随机分为雷帕霉素组(n=12)和环孢霉素组(n=12),术后分别给予雷帕霉素1.25mg/(kg·d)灌胃及环孢霉素A10mg/(kg·d)皮下注射,给药60d,给药结束后留取移植心脏待检。③另12只SD大鼠直接取心脏组织作为正常对照组。指标检测:①对移植心脏组织行VanGieson染色后采用Miassystem4.1医学图像分析管理系统分析血管狭窄程度。②应用反转录-聚合酶链反应检测血小板衍生生长因子AmRNA在移植心脏组织中的表达情况。结果:36只受体SD大鼠及12只正常SD大鼠全部进入结果分析,无脱失。①同系移植组、环孢霉素组及雷帕霉素组大鼠的冠状动脉狭窄指数均显著高于正常对照组[(13.12±0.72)%,(62.45±8.12)%,(28.91±3.24)%,(0.09±0.02)%(P<0.01)],环孢霉素组及雷帕霉素组高于同系移植组(P<0.05),环孢霉素组高于雷帕霉素组(P<0.01)。②正常对照组、同系移植组、环孢霉素组及雷帕霉素组大鼠的血小板衍生生长因子AmRNA相对含量分别为0.19±0.06,0.21±0.08,1.12±0.22及0.47±0.11,环孢霉素组、雷帕霉素组显著高于同系移植组(P<0.01),环孢霉素组高于雷帕霉素组(P<0.05)。结论:血小板衍生生长因子AmRNA的高表达与移植心脏的血管硬化有关;雷帕霉素具有预防大鼠心脏移植物血管病变的作用,其作用可能与抑制心脏组织中血小板衍生生长因子AmRNA的表达有关。     

Drogen und Arzneimittelabusus in der Frauenheilkunde

Addiction in women has many implications in the field of obstetrics and gynecology. Particularly in obstetrical care, the health needs of the unborn as well as of the pregnant patients have to be considered. Therefore, early somatic and psychosocial help should be offered to pregnant women with addiction disorders. The main elements of this concept will be presented along with a summary of typical comorbidity issues in these patients, the handling of drug-related emergencies, and the management of perioperative replacement therapy.     

Force deficits after stretches of activated rat muscle-tendon complex with reduced collagen cross-linking

The forces produced during stretches of passive and activated muscles, and isometric force deficits after stretching of activated muscles were examined in rat plantor flexor muscle-tendon complexes with reduced collagen cross-links (pyridinoline). Female Sprague-Dawley rats (n=6, age 87 days) were injected twice daily for 43 days with β-aminopropionitrile (BAPN, 333 mg/kg/day i.p.), an inhibitor of lysyl oxidase, which is responsible for the production of collagen cross-links. The relative weights of the plantar flexor muscles were similar for BAPN and saline-injected (control, C) rats (n=6). Pyridinoline was lower in the tendon (22.9%), and in the plantaris (17.1%), and soleus (7.4%) muscles (P<0.05), with no changes observed in collagen content (hydroxyproline), as determined by high-pressure liquid chromatography. At an ankle position of 90°, groups had similar forces at 5, 10, 20, 40, 60 and 80 Hz before stretching. Forces at 40° with stretches of the passive muscles (five times from 90° to 40°) were lower for all stretches in BAPN-injected rats (P<0.05). Isometric force deficits resulting from stretches of activated muscles (80 Hz, 20 times from 90° to 40°, rest intervals 3 min) followed similar courses for BAPN-injected and C rats, and were 51.1 (2.4)% (C) and 54.7 (4.6)% (BAPN) before the last stretch. After 1 h of rest, isometric force deficits were 26% and 29% larger at 10 Hz and 5 Hz, respectively, in BAPN-treated rats (P<0.05). The reduction in BAPN-injected collagen cross-linking of the skeletal muscle-tendon complex reduced the forces produced during stretches without muscle stimulation (i.e. passive stretch), and stretching of activated muscles produced larger isometric force deficits only at low stimulation frequencies. Electronic Publication