Muscle function in elite master weightlifters

PURPOSE: To determine whether explosive power and isometric strength of the lower-limb muscles in elite master Olympic weightlifters declines at a similar rate to nontrained healthy controls with increasing age. METHODS: 54 elite level masters weightlifters (aged 40-87), who were competitors at the World Masters Weightlifting Championships (1999), were compared with a similar number of aged-matched, healthy untrained individuals. Isometric knee extensor strength and lower-limb explosive power were tested. Extent of antagonist co-contraction during isometric knee extension was determined by EMG and power loading characteristics by using a variable inertial system. Muscle volume was estimated using anthropometry. RESULTS: On average, the weightlifters were able to generate 32% more peak power (P < 0.05) in the lower limbs and 32% more isometric knee extensor force (P < 0.05) than the control subjects. No significant differences in lower-leg volume were observed between the two groups. Peak power declined at a similar rate with increasing age in the weightlifters and controls (1.2 and 1.3% of a 45-yr-old's value per year), as did strength, but at a lower rate (0.6 and 0.5% per year). The inertial load at which the weightlifters achieved their maximal peak power output was greater (P < 0.05) than the controls. The torque generated at this optimal inertia was also greater in the weightlifters (P < 0.05), whereas the time taken for the weightlifters to reach their maximal peak power was on average 13% shorter (P < 0.05). No differences in antagonist co-contraction during isometric knee extension were observed between the two groups. CONCLUSIONS: Muscle power and isometric strength decline at a similar rate with increasing age in elite master weightlifters and healthy controls. In spite of inertial load optimization, muscle power declined in both groups at approximately twice the rate of isometric strength. Although similar rates of decline were observed, the absolute differences between the weightlifters and controls were such that an 85-yr-old weightlifter was as powerful as a 65-yr-old control subject. This would therefore represent an apparent age advantage of approximately 20 yr for the weightlifters.     

腹腔镜下与经腹股沟精索内静脉结扎术的比较研究

目的：比较两种精索静脉曲张手术的临床应用价值。方法：选择117例双侧精索静脉曲张的病例,分别行经腹股沟切口精索内静脉结扎术52例,腹腔镜下精索内静脉高位结扎术65例,对两组病例的术中经过、恢复过程、术后效果进行对比分析。结果：两组术后经腹股沟组复发2例,腹腔镜组无复发;两组治疗效果无差异;手术并发症分别发生3例及1例单侧阴囊水肿;手术时间经腹股沟组明显少于腹腔镜组;平均住院时间腹腔镜组明显少于经腹股沟组。腹腔镜手术术中解剖更清晰、损伤更小、可分离睾丸动脉,术后康复更快。结论：腹腔镜下精索静脉高位结扎术比开放手术居优势,尤其对双侧精索静脉曲张者。     

Creutzfeldt–Jakob disease

Creutzfeldt–Jakob disease (CJD) is a progressive, degenerative, and fatal disease of the central nervous system. It is caused by abnormal accumulation of prion proteins and is characterized mainly by progressive dementia, myoclonus, and cerebellar, pyramidal, and extrapyramidal findings. Psychiatric symptoms may also accompany CJD and are often the first signs of the disease. The incidence of CJD is approximately 1 in 1 000 000. In certain cases, a diagnosis can be made by demonstrating the accumulation of pathological prion proteins. However, in many cultures brain biopsies or post‐mortem evaluations are not welcomed by either the patients or their relatives. In these cases, the importance of additional diagnostic tools increases. Herein, we report on a CJD patient who first consulted a psychiatrist with early psychiatric symptoms. The patient developed neurological symptoms later and was subsequently diagnosed as sporadic CJD based on clinical and laboratory findings rather than brain biopsy. Repeated electroencephalograms (EEG) played a pivotal role in our evaluation of the patient. This case is an interesting presentation of CJD both because of the timing of the symptoms and because of the typical EEG findings that led to the diagnosis.     

Suxamethonium and critical illness polyneuropathy

Administration of suxamethonium to patients with critical illness polyneuropathy may produce life-threatening hyperkalaemia. A questionnaire to assess the awareness of this problem was sent to all UK intensive care units. A clinical scenario suggestive of critical illness polyneuropathy was accompanied by a list of possible drugs used to facilitate endotracheal intubation. Most respondents (68.7%) chose suxamethonium while 20.4% avoided any muscle relaxant. This result suggests a worrying lack of appreciation of the dangers of suxamethonium use in critical illness polyneuropathy.     

Methicillin-susceptible, non-multiresistant methicillin-resistant and multiresistant methicillin-resistant Staphylococcus aureus infections: a clinical, epidemiological and microbiological comparative study

Non-multiresistant methicillin-resistant Staphylococcus aureus (nmMRSA) infections are emerging worldwide and are often community-associated. This prospective case–cohort study compares features of 96 nmMRSA clinical isolates with 96 matched multiresistant MRSA (mMRSA) and 192 matched methicillin-susceptible S. aureus (MSSA) clinical isolates. Seventy-four percent of nmMRSA infections were healthcare-associated. nmMRSA infections were much more likely to involve skin and soft tissue (skin and soft tissue infections; SSTIs) and were much less likely to be treated appropriately with antibiotics than MSSA or mMRSA infections. Panton-Valentine leukocidin (PVL) genes were detected in 55% of nmMRSA, 16% of MSSA and 2% of mMRSA isolates. Independent of the methicillin-resistance phenotype, 59% of PVL-positive SSTIs presented as furunculosis compared to only 10% of PVL-negative SSTIs. Patients with PVL-positive infections were much younger than patients with PVL-negative infections. The proportion of PVL-positive infections peaked in the 10–29 years old age group, followed by a linear decline.     

An activation antigen on a subpopulation of B lymphocytes identified by the monoclonal antibody CMRF-17.

The identification of membrane molecules expressed on subpopulations of B lymphocytes is of potential significance because these molecules may be candidates for regulating the activation, proliferation and differentiation of B cells. A new monoclonal antibody, CMRF-17, which reacts with a subpopulation of tonsil B lymphocytes has been produced. The antibody did not react with T lymphocytes in tonsil or peripheral blood nor most peripheral blood B lymphocytes but did label erythrocytes and some platelets. In tonsil, the germinal centre cells, cells in the interfollicular region and endothelial cells were positive, but mantle zone B cells were negative. Double labelling experiments showed that CMRF-17 reacted with activated tonsillar lymphocytes. The antigen recognized by CMRF-17 was heat stable, resistant to treatment with proteolytic enzymes and neuraminidase and was shown to be a carbohydrate determinant on one or more glycolipids. These characteristics of the antigen recognized by CMRF-17 and its pattern of reactivity distinguish this antibody from other monoclonal antibodies recognizing B-cell activation markers. It was notable that of the B-lymphoid malignancies tested to date, including those of probable follicular origin, few stained with CMRF-17.