Catastrophic failure of modular Zirconia—Ceramic femoral head components after total hip arthroplasty

Catastrophic failure of two zirconia—ceramic modular femoral heads occurred, despite the theoretical improved toughness of zirconia—ceramic relative to alumina—ceramic. This experience led the authors to return to cobalt—chromium as the metal of choice for articulation against polyethylene in total hip arthroplasty.     

党参总碱对东莨菪碱引起小鼠记忆障碍和脑内乙酰胆碱及胆碱乙酰化酶的作用

用跳台法观察到党参总碱(DSA)能改善东莨菪碱(Scop)引起的记忆障碍,并能对抗Scop所致小鼠脑内乙酰胆碱(ACh)浓度下降及胆碱乙酰化酶(ChAT)活性的降低。体外实验发现当在反应液中加入DSA后,ChAT生成ACh的量增加。     

乙醇毒染大鼠睾丸总抗氧化能力、一氧化氮和一氧化氮合酶的变化与生殖细胞凋亡的关系

目的:探讨饮酒大鼠睾丸总抗氧化能力(T-AOC)、一氧化氮(NO)含量和一氧化氮合酶(NOS)活性的变化与生殖细胞凋亡的关系。方法:20只成年健康SD雄性大鼠随机均分为对照组和实验组,实验组和对照组分别用50%的乙醇溶液和蒸馏水按10 m l/kg每晚灌胃1次连续26 d(两个生精周期)后,用硝酸还原酶法测定睾丸组织中NO含量;用化学比色法测定其T-AOC和NOS活性;原位缺口末端标记(TUNEL)法检测生殖细胞凋亡指数(AI)的变化。结果:与对照组相比,实验组生殖细胞AI增加(P<0.01);睾丸组织T-AOC极显著下降(P<0.01),而NO含量明显上升(P<0.01)、NOS活性显著增强(P<0.01)。结论:大量饮酒能诱导生殖细胞凋亡增加,NOS活性增强导致NO的过量产生及T-AOC的显著下降是其重要原因。     

Reinforcement rings in acetabular revisions: our trends

The authors, reviewing the international literature with their clinical experience developed in reconstructive surgery of acetabular defects due to aseptic loosening of acetabular cups, suggest their guidelines to the right use of acetabular reinforcement rings. Received: 8 September 2001/Accepted: 4 November 2001     

四逆汤煎煮过程中乌头类生物碱的溶出和水解平衡

目的 研究四逆汤中乌头类生物碱的溶出平衡和水解平衡。方法 利用电喷雾质谱分析，比较了制附子、四逆汤、四逆汤药渣和含有3种双酯型生物碱的混合对照品体系中的乌头碱类二萜生物碱。结果 在煎煮过程中双酯型生物碱溶解并发生水解反应，而脂类生物碱则难溶于水。乌头碱、中乌头碱、次乌头碱水溶性相近，但是次乌头碱在水中的热稳定性更高，C19二萜骨架上C3取代基(—OH或—H)的变化影响生物碱的稳定性。结论四逆汤中的乌头碱类生物碱的种类及含量由其溶解性和化学稳定性共同决定。     

Total extrusion of the talus: A case report

Total extrusion of the talus without recovery of the bone is a very unusual injury. The authors present a case of a 25-year-old man who sustained an open total enucleation of the talus in a motorcycle accident. The talus was not recovered at the scene of the accident. An immediate tibiocalcaneal stabilization was performed by using an external fixator. In the postoperative period, a polymicrobic infection was observed and treated with parenteral antibiotics. Nine months after injury, the patient developed an infection of both the empty space and the distal third of the tibia. A wound debridement with tibial sequestrectomy and insertion of gentamicin-impregnated polymethylmethacrylate beads was performed. Three months later, after multiple negative bacteriologic examinations, a tibiocalcaneal arthrodesis with staples and autogenous bone graft was performed. Because of a pseudoarthrosis, the patient underwent a revision of the arthrodesis by retrograde tibiocalcaneal nailing, achieving clinical and radiographic success. The definitive treatment of total enucleation of the talus is still controversial because of its rarity and the high rate of complications, such as avascular necrosis, osteomyelitis, and ankle stiffness. In this case, without recovery of the talus, retrograde nailing afforded good stability by bypassing the bone defects.     

Stereological ultrastructural analysis of rat cardiomyocytes after total hyperthermia

Hyperthermia results in the suppression of intracellular regeneration in cardiomyocytes, manifested as intensified lysis and destruction of organelles, and leads to myocardial atrophy. Intracellular reorganization of cardiomyocytes is characterized by increases in the volume and surface density of myofibrils, sarcoplasmic reticulum, and T system. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 1, pp. 96–100, January, 1994 Presented by V. A. Trufakin, Member of the Russian Academy of Medical Sciences     

Estimating neuron dendritic length in 3D from total vertical projections and from vertical slices

The recently developed method of total vertical projections is illustrated to estimate the total dendritic length of a human Substantia Nigra neuron. Next, the length of the different orders of dendritic branches, and the mean segment length for each order - commonly regarded as important parameters in neuron physiology - are also estimated. Finally, it is shown how to estimate the mean dendritic length in a population of neurons from vertical slices of arbitrary and unknown thickness. Being unbiased and highly efficient, the proposed methods offer interesting alternatives to current procedures used for the metric analysis of neuron arborizations.     

ARTHROSCOPIC REMOVAL OF ACRYLIC CEMENT FROM UNREDUCED HIP PROSTHESIS

A case is reported in which entrapped polymethylmethacrylate following traumatic dislocation of a total hip replacement prevented complete reduction. A combined arthroscopic and fluoroscopic technique was used to remove the entrapped polymethylmethacrylate. Manipulation of the total hip prosthesis was done after removal of polymethylmethacrylate to minimize mechanical abrasion. This technique allows direct visual assessment of the articulating surfaces as well as the mechanical stability of the prosthesis. The morbidity related to the procedure is minimal and a short rehabilitation period is the major advantage.