再生医学技术在烧伤传统治疗无效病人中的应用(附38例报告)

目的：总结重度烧伤传统疗法无效改为再生医学(MEBT/MEB0)技术治疗变化规律和临床验．方法：将我科l995年5月至2002年5月收治的院外采用传统疗法无效改用MEBT/MEBO技术治疗的38例重度烧伤病人临床资料进行回顾性总结，病人一旦入院创面均改用MEBT/MEBO治疗，初始予以彻底清创，规范用药、规范操作，规范认识；全身实行系统综合治疗措施．以临床观察和病人感觉评价治疗效果。结果：本组38例全部治愈，末植皮自行愈合者21例．占55.26％．深Ⅲ度创面自愿要求植皮者17例，占44.74％。经随访多数无增生性瘢痕，部分愈后有局限性瘢癌，质软无残废。结论：重度烧伤经传统疗法久治不愈或疗效欠佳病人．病情复杂，并发症较多治疗难度也较大，再生医学可有效改善以上缺陷和病症．是重度烧伤病人传统治疗无效时的理想疗法。     

A Test to Detect Chest Tube Kinking

Objectives: To determine whether the Mac‐technique test can detect kinking of the chest tube upon thoracostomy tube placement. Methods: This was a prospective observational study that was conducted October 2000 through October 2001 in an urban Level 1 trauma center. There were 103 consecutive nonrandomized adult trauma patients who required immediate tube thoracostomy during their initial resuscitation who were entered into the study. The Mac‐technique test was performed during standard tube thoracostomy insertion to the appropriate depth. The test involved grasping the external portion of the thoracostomy tube, turning it clockwise 180°, and then releasing the tube. If the tube spontaneously spun back to its original position, the test was considered positive, and the tube was considered kinked. If the tube did not spontaneously spin back and stayed in position upon release, the test was considered negative. Regardless of the results of this test, the tube was secured, and a postprocedure chest radiograph was obtained. The criterion standard for determining a kinked chest tube was its appearance on this chest radiograph. Results: A total of 103 chest tubes were placed by using the Mac‐technique test. The test was positive in eight placements; four tubes were kinked on chest radiograph. The Mac‐technique test was negative in 95 placements; four tubes were kinked on chest radiograph. The Mac technique had a sensitivity of 50% (95% confidence interval [CI] = 15.7% to 84.3%), a specificity of 95.8% (95% CI = 89.6% to 98.8%), a positive likelihood ratio of 11.9, a negative likelihood ratio of 0.52, and an odds ratio using Yates correction of 20.3 (95% CI = 4.1 to 102.1). Conclusions: On the basis of this study, a positive Mac‐technique test is useful to detect chest tubes that are likely to be kinked after insertion and before securing.     

Fatal encephalitis in a patient with refractory celiac disease presenting with myorhythmia and carpal spasm.

We report the case of a woman with refractory celiac disease who developed abnormal spontaneous movements of the extremities and face consistent with myorhythmia. Investigation led to a diagnosis of encephalitis, confirmed by postmortem examination. The movements were likely caused by nonparaneoplastic encephalitis associated with refractory celiac disease. Etiologic and diagnostic considerations and treatment options are discussed.     

Chronic Inhalation Toxicity and Carcinogenicity Testing of Respirable Fibrous Particles

On May 8–10, 1995, a workshop on chronic inhalation toxicity and carcinogenicity testing of respirable fibrous particles was held in Chapel Hill, North Carolina. The workshop was sponsored by the Office of Pollution Prevention and Toxics, U.S. Environmental Protection Agency (EPA), in collaboration with the National Institute of Environmental Health Sciences (NIEHS), the National Institute for Occupational Safety and Health (NIOSH), and the Occupational Safety and Health Administration (OSHA). The goal of the workshop was to obtain input from the scientific community on a number of issues related to fiber testing. Major issues for discussion were: (i) the optimal design and conduct of studies of the health effects of chronic inhalation exposure of animals to fibers; (ii) preliminary studies which would be useful guides in designing the chronic exposure study; (iii) mechanistic studies which would be important adjuncts to the chronic exposure study to enable better interpretation of study results and extrapolation of potential effects in exposed humans; and (iv) available screening tests which can be used to develop a minimum data set for (a) making decisions about the potential health hazard of the fibers and (b) prioritizing the need for further testing in a chronic inhalation study. After extensive discussion and debate of the workshop issues, the general consensus of the expert panel is that chronic inhalation studies of fibers in the rat are the most appropriate tests for predicting inhalation hazard and risk of fibers to humans. A number of guidances specific for the design and conduct of prechronic and chronic inhalation studies of fibers in rodents were recommended. For instance, it was recommended that along with other information (decrease in body weight, systemic toxicity, etc.), data should be obtained on lung burdens and bronchoalveolar lavage fluid analysis to assist in establishing the chronic exposure levels. Lung burden data are also important for quantifying aspects of risk assessment related to dosimetric adjustments before extrapolation. Although mechanistic studies are not recommended as part of the standard chronic inhalation studies, the expert panel stressed the need for obtaining mechanistic information as far as possible during the course of subchronic or chronic inhalation studies. At present, no single assay and battery of short-term assays can predict the outcome of a chronic inhalation bioassay with respect to carcinogenic effects. Meanwhile, several short-termin vitroandin vivostudies that may be useful to assess the relative potential of fibrous substances to cause lung toxicity/carcinogenicity have been identified.     

Nitric oxide neurotoxicity

Derangements in glutamate neurotransmission have been implicated in several neurodegenerative disorders including, stroke, epilepsy, Huntington's disease, Alzheimer's disease, and amyotrophic lateral sclerosis (ALS). Activation of the N-methyl- -aspartate (NMDA) receptor subtype of glutamate receptors results in the influx of calcium which binds calmodulin and activates neuronal nitric oxide synthase (nNOS), to convent -arginine to citrulline and nitric oxide (NO). NO has many roles in the central nervous system as a messenger molecule, however, when generated in excess NO can be neurotoxic. Excess NO is in part responsible for glutamate neurotoxicity in primary neuronal cell culture and in animal models of stroke. It is likely that most of the neurotoxic actions of NO are mediated by peroxynitrite (ONOO−), the reaction product from NO and superoxide anion. In pathologic conditions, peroxynitrite and oxygen free radicals can be generated in excess of a cell antioxidant capacity resulting in severe damage to cellular constitutents including proteins, DNA and lipids. The inherent biochemical and physiological characteristis of the brain, including high lipid concentrations and energy requirements, make it particularly susceptible to free radical and oxidant mediated insult. Increasing evidence indicates that many neurologic disorders may have components of free radical and oxidative stress induced injury.