Detrended fluctuation analysis detects altered coordination of running gait in athletes following a heavy period of training

Objectives

To investigate whether functional overreaching affects locomotor system behaviour when running at fixed relative intensities and if any effects were associated with changes in running performance.

Predicting failure in polytetrafluoroethylene vascular access grafts for hemodialysis: a pilot study

In order to determine if serial, noninvasive evaluation of polytetrafluoroethylene (PTFE) vascular access grafts could identify a subgroup of patients at risk for thrombosis, the authors studied flow characteristics, using duplex ultrasonic scanning, in 18 hemodialysis patients with forearm loop grafts. On average, five examinations were performed per patient over the 10-month study period. Seven episodes of thrombosis occurred in six patients. The mean Doppler flow in grafts that subsequently thrombosed was significantly lower than in those that did not (544 +/- 218 ml/min versus 843 +/- 391 ml/min, p less than 0.001). The interval from last examination to thrombosis ranged from 13 to 58 days. At a defined cut-off flow of 450 ml/min, this test yielded a sensitivity of 83% and a specificity of 75% for episodes of thrombosis occurring within 2 to 6 weeks. The authors conclude that episodes of thrombosis in PTFE arm loop grafts are usually preceded by significantly lower Doppler-measured flow than grafts that do not thrombose and that it may be possible, by this means, to identify grafts at risk.     

AMPK在妊娠期糖尿病发病机制中的作用

腺苷酸活化蛋白激酶是一种重要的蛋白激酶,主要作用是协调代谢和能量平衡.腺苷酸活化蛋白激酶被激活后,在增加骨骼肌对葡萄糖摄取、增强胰岛素敏感性、增加脂肪酸氧化以及调节基因转录等方面发挥重要作用.已经证实脂联素有调节糖脂代谢的作用,但其作用机制尚不十分清楚,很可能是通过腺苷酸活化蛋白激酶介导,对脂联素信号转导通路的研究将成为进一步理解脂联素作用的关键所在.而脂联素又是妊娠期糖尿病的预测因子,所以腺苷酸活化蛋白激酶逐渐成为对妊娠期糖尿病研究中的焦点.     

Prolactin and known modulators of rat splenocytes activate nuclear protein kinase C

Prolactin (PRL) and other trophic factors rapidly activate a nuclear pool(s) of protein kinase C (nPKC) in purified splenocyte nuclei. The PRL also enhanced [2-3H]glycerol incorporation into nuclear mono- and triacylglycerol. An assay was devised which not only probed the ability of the hormone to activate protein kinase C (PKC) but also demonstrated the presence of nuclear substrates. Using this methodology, a biphasic concentration-response curve to PRL was observed. Heterologous species of PRL and various growth factors also activated nPKC. The PRL-induced nPKC stimulation was antagonized by various immunomodulators, G protein-coupling inhibitors, PKC inhibitors, a calmodulin inhibitor, and a peripheral benzodiazepine agonist and antagonist. A monoclonal antibody to PKC, anti-rat PRL antiserum and a monoclonal anti-rat PRL receptor antibody antagonized PRL-induced PKC-dependent nuclear phosphorylation, further implicating nPKC and a PRL receptor-mediated activation process. Nuclear PKC may be a major target for trophic regulation in response to both positive and negative growth signals.     

Endoscopic cleaning and disinfection procedures for preventing iatrogenic spread of human immunodeficiency virus

With estimates as high as 1.8 million individuals infected with human immunodeficiency virus (HIV) in the United States, the majority asymptomatic, it is crucial that all physicians routinely use adequate disinfection procedures for medical instruments. The protosigmoidoscopic disinfection procedures used by US family physicians were evaluated for adequacy in inactivating HIV. Sixty-seven percent of 1,585 randomly selected American Academy of Family Physicians members completed a mail survey regarding these procedures. Comparing procedures used with those recommended by the Centers for Disease Control or documented to inactivate HIV, 32.4 percent were judged to be appropriate procedures; 54.4 percent of the procedures were not tested or recommended; and 13.2 percent used appropriate solutions but at inadequate concentrations or exposure times. Therefore, a substantial proportion of US family physicians performing endoscopic procedures use disinfection procedures that may not inactivate HIV. The ever-increasing prevalence of HIV demands that standardized adequate disinfection procedures be implemented by all physicians to prevent the potential nosocomial spread of HIV.