Arteriography for proximity of injury in penetrating extremity trauma.

Arteriography for proximity of injury was studied prospectively at a trauma center. Findings in 85 patients with penetrating extremity wounds were analyzed to determine the prevalence and types of vascular abnormalities seen with these injuries. Ninety-two limb segments were studied for 77 gunshot and 15 stab wounds. Arteriographic findings were positive in 24% overall but in only 5% for injuries confined to major vessels. A 60% positive rate was seen in a small subgroup of 10 patients with fractures due to gunshot wounds. The most frequently injured vessels were muscular branches of the deep femoral artery (59%); the most common injury was focal, non-occlusive spasm (42%). All patients were treated conservatively, without sequelae at follow-up. In this study, the vascular injuries found at arteriography for proximity of injury in penetrating trauma due to bullets of knives, particularly in the thigh, did not require surgical or radiologic intervention.     

A randomized trial of temperature-controlled radiofrequency, continuous positive airway pressure, and placebo for obstructive sleep apnea syndrome

OBJECTIVE: The study goal was to determine the effectiveness of (1) multilevel temperature-controlled radiofrequency tissue ablation (TCRFTA) or (2) continuous positive airway pressure (CPAP) for the treatment of mild to moderate obstructive sleep apnea syndrome (OSAS). STUDY DESIGN AND METHODS: We conducted a randomized, placebo-controlled, 2-site trial, comparing TCRFTA (n = 30) and CPAP (n = 30) with sham-placebo (n = 30) using intention-to-treat analysis. RESULTS: Compared with pretreatment baseline, TCRFTA improved reaction time, OSAS-specific quality of life (QOL), and subjective sleepiness (all P < 0.05). Compared with sham-placebo, TCRFTA improved QOL, airway volume, apnea index, and respiratory arousal index (all P < 0.05). TCRFTA side effects and complications were mild, temporary, and similar to sham-placebo. CPAP improved QOL and sleepiness compared with baseline and QOL when compared with sham-placebo (all P < 0.05). Significant differences were not seen between TCRFTA and CPAP outcomes. CONCLUSION: TCRFTA and CPAP each improve QOL for mild-moderate OSAS patients. TCRFTA improvements may result from changes in airway volume, apnea index, and respiratory arousal index.     

4-甲氧羰基-4-N-丙酰苯胺基哌啶1位衍生物的合成及其镇痛作用

本文报道了一系列N-[-1(2-苯乙基-4-甲氧羰基-4-哌啶基]-N-丙酰苯胺(4-甲氧羰基芬太尼)哌啶环1位取代衍生物的合成及其镇痛活性;讨论了结构与镇痛活性之间的关系。药理试验结果表明,大部分化合物具有典型的吗啡样镇痛活性,是一类作用极强的麻醉性镇痛剂。特别是哌啶环1位β-苯环被取代乙烯基替代的化合物具有相当或接近子母体化合物的镇痛活性。其代表物1321的镇痛活性(ED_(50)=0.005mg/kg ip,小鼠,热板法)略强于4-甲氧羰基芬太尼(ED_(50)=0.0063 mg/kg)。     

Nasal obstruction and pulmonary function: the role of humidification

The function of the nose in respiration is poorly understood. This article reports on two studies of the effects of nasal obstruction on pulmonary function. First, blood gases were studied in 71 patients undergoing intranasal surgery. Patients with bilateral nasal packing had an average PO2 drop of 6.9 mm Hg. Lung disease and polyps were more prevalent in patients who showed a significant drop in PO2, and those who became most hypoxic complained of a dry throat. The second study tested the influence of humidification. Pulmonary function and blood gases were measured in 10 subjects before and after nasal occlusion. Those breathing only dry air had a drop in compliance after nasal clipping. When air was humidified, nasal occlusion had no significant effect. Humidification may be an important respiratory function of the nose. Any future studies of the nasopulmonary relationship should adequately control for humidity and bronchial reactivity.     

The amplitude of post-tetanic potentiation of the EPSP RC1-R15 in Aplysia is modulated by environmental parameters.

Evidence is presented that the EPSP called RC1-R15, which is recorded from cell R15 of the abdominal ganglion of Aplysia californica upon appropriate stimulation of the right connective, is endogenously active. In previous studies we showed that after repetitive stimulation the amplitude of this EPSP increases and then slowly decays over many minutes, a phenomenon called post-tetanic potentiation (PTP). The rate of endogenous firing of this EPSP varies with time of day and tonicity of the animal's external environment. It is shown that this endogenous firing increases the magnitude of the PTP component of the amplitude of the EPSP. The degree of this potentiation varies with the endogenous firing rate. In general, daytime or a hypertonic external environment increases the firing rate of the EPSP and its degree of potentiation. Since the degree of this PTP reflects time of day and environmental tonicity, it is inferred that it conveys physiologically significant information to the postsynaptic cell R15.     

Permissive influence of stress in the expression of a U-shaped relationship between serum corticosterone levels and spatial memory errors in rats

The relationship between glucocorticoids (GCs) and memory is complex, in that memory impairments can occur in response to manipulations that either increase or decrease GC levels. We investigated this issue by assessing the relationship between serum corticosterone (the primary rodent GC) and memory in rats trained in the radial arm water maze, a hippocampus-dependent spatial memory task. Each day, rats learned a new location of the hidden escape platform and then 30 min later their memory of the location of the platform was tested. Under control conditions, well-trained rats had excellent spatial memory and moderately elevated corticosterone levels (approximately 26 microg/dl versus a baseline of approximately 2 microg/dl). Their memory was impaired when corticosterone levels were either reduced by metyrapone (a corticosterone synthesis inhibitor) or increased by acute stress (predator exposure), forming an overall U-shaped relationship between corticosterone levels and memory. We then addressed whether there was a causal relationship between elevated corticosterone levels and impaired memory. If elevated corticosterone levels were a sufficient condition to impair memory, then exogenously administered corticosterone, alone, should have impaired performance. However, we found that spatial memory was not impaired in corticosterone-injected rats that were not exposed to the cat. This work demonstrates that an intermediate level of corticosterone correlated with optimal memory, and either a decrease or an increase in corticosterone levels, in conjunction with strong emotionality, impaired spatial memory. These findings indicate that fear-provoking conditions, which are known to engage the amygdala, interact with stress levels of corticosterone to influence hippocampal functioning.     

Clinical experience with lingualplasty as part of the treatment of severe obstructive sleep apnea.

Because uvulopalatopharyngoplasty (UPPP) as the sole procedure for severe obstructive sleep apnea syndrome (OSAS) is often inadequate, multiple other procedures have been developed. These have been directed at other sites of potential collapse of the upper airway. Initial experience with midline glossectomy (MLG) has shown direct modification of the tongue base to be an effective procedure in a subset of patients with OSAS. Lingualplasty, a modification of MLG, is demonstrated to provide an improved response rate. Twenty-two consecutive patients with severe OSAS and Fujita type II airway classification (retropalatal, oropharyngeal, and hypopharyngeal compromise) underwent lingualplasty. Fourteen patients had previously undergone unsuccessful UPPP. Eight had synchronous lingualplasty and UPPP. All were selected for lingualplasty because of obstructive tongue base anatomy. Responders were defined as having a respiratory disturbance index (RDI) of less than 20 events/hour. For the entire group, 17 of 22 (77%) were classified as responders, with RDI decreasing from 58.8 +/- 39.5 events/hour to 8.1 +/- 6.2 events/hour. Lingualplasty, as an isolated procedure, resulted in a 79% responder rate, with RDI decreasing from 50.2 events/hour to 8.6 events/hour. There were no significant changes in the RDI of the nonresponder groups. No differences were identified that discriminated responders from nonresponders, including age, body mass index, or cephalometry. There were six complications (27%), including bleeding (3), tongue edema (1), prolonged odynophagia (1), and subcutaneous emphysema related to tracheotomy (1). All resolved with treatment. These results indicate that in appropriately selected patients who do not respond to UPPP, lingualplasty is a significant improvement over MLG.