Pathophysiology of nerve injury

The response to nerve injury is a complex and often poorly understood mechanism. An in-depth and current command of the relevant neuroanatomy, classifications systems, and responses to injury and regeneration are critical to current clinical success. Continued progress must be made in our current understanding of these varied physiologic mechanisms of neuro-regeneration if any significant progress in clinical treatments or outcome is to be expected in the future. Reconstructive surgeons have in many ways maximized the technical aspects of peripheral nerve repair. However, advances in functional recovery may be seen with improvements in sensory and motor rehabilitation after peripheral nerve surgery and with a combined understanding of the neurobiology and neurophysiology of nerve injury and regeneration.     

Effects of delaying FK506 administration on neuroregeneration in a rodent model

FK506 is an immunosuppressant drug that has been shown experimentally to stimulate nerve growth and speed functional recovery, when administered immediately after peripheral nerve injury. However, the clinical scenario of a peripheral nerve injury is often associated with either a delayed diagnosis or reconstruction. The purpose of this study was to determine the efficacy of FK506 on neuroregeneration with delayed administration. Thirty-two Lewis rats underwent tibial nerve transection with immediate repair. Animals were left untreated, or were treated with daily injections of FK506 (2 mg/kg), started on the day of surgery, postoperative day 3, or postoperative day 5. Animals underwent walking track analysis to assess functional nerve recovery. Nerves were harvested for histomorphometric analysis on postoperative days 21, 28, and 42. Histomorphometry demonstrated that all treatment groups, regardless of the time of drug initiation, demonstrated evidence of enhanced neuroregeneration, compared to the untreated group. Histomorphometric data from groups harvested on day 21 demonstrated a statistically significant improvement in neuroregeneration in the immediate and 3-day delay groups. Therefore, the beneficial effects of FK506 on neuroregeneration are not restricted to immediate administration, but these effects significantly diminish when FK506 is administered 3 days after nerve injury.     

Low grade fibromyxoid sarcoma of the falciform ligament: a case report

Background  

Low grade fibromyxoid sarcomas (LGFMS) are very rarely seen. They commonly arise from deep soft tissues of the lower extremities. Very few cases of intra-abdominal location have been reported.     

Intraindividual variation in recent stress exposure as a moderator of cortisol and testosterone levels

Intraindividual variation in recent stress exposure and its impact upon cortisol and testosterone was investigated. Over 1 year, 72 young male firefighters completed the Daily Stress Inventories, for 2 shift cycles (16 days), every 3 months. At the end of each 16-day period each participant attended a 1-hr morning assessment session. Saliva samples and blood pressure measurements were taken at 10-min intervals, and at 30 min, a blood sample was drawn. Across the year of assessment, there were significant linear relationships in reported stress and in neuroendocrine activity. In contrast to expectations, as daily stress decreased across the year (p < .008), salivary cortisol increased (p < .001) and testosterone levels decreased (p < .001). Within-subjects comparisons of the sessions with the highest and lowest stress confirmed these linear relationships: Lower stress prior to the assessment session was associated with higher cortisol levels (p < .01). These results, though in contrast to the orthodoxy concerning the association between stress and cortisol, are supported by findings in a number of other studies and may constitute down regulation of cortisol activity following an increment in stress exposure. This research was supported by the Medical Research Council, United Kingdom. We are grateful to the London Fire & Civil Defence Authority for their cooperation.     

Detection of carbamyl phosphate synthetase 1 deficiency using duodenal biopsy samples

The activity of urea cycle enzymes was assayed in duodenal biopsy specimens obtained from a female infant who presented with neonatal hyperammonaemia. All enzyme levels were normal except N-acetyl glutamate-dependent carbamyl phosphate synthetase 1 (CPS1) which was half the mean activity in normal control specimens. A similar deficiency of CPS1 was also shown in duodenal specimens from the patient's mother who became slightly symptomatic after relatively high protein meals and during pregnancy, and had spontaneously modified her diet to one with protein restriction. The patient is growing normally on a dietary regimen similar to that spontaneously adopted by her mother. Urea cycle enzyme activity in the duodenal biopsy material from the controls was similar to that found in the normal human liver and appears to have distinct advantages as a means of assaying for urea cycle defects in patients with hyperammonaemia and their relatives.     

儿童癌症幸存者成年后的慢性疾病

由于治疗方法的进步,近80%的儿童和青少年癌症患者能够长期生存。在美国,约有270000例儿童癌症的幸存者,即每640名20至39岁成年人中就有一名幸存者。大量的幸存者有利于儿童癌症治疗后长期健康结果的研究。现在可以明确的是,化疗和放疗所致的儿童各器官系统损害在临床上可能潜伏多年。为了全面了解治疗儿童癌症而继发的健康问题,重要的是衡量三项长期结果:健康状况、死亡率和患病率。这三项中,关于前两项已有相当好的研究报道。在一项对20227例癌症5年生存者的回顾性分析中,Mertens等发现以下原因导致的超额死亡率具有统计学意义:继发癌症(…