Corticofugal modulation of the information processing in the auditory thalamus of the cat

Summary Single unit activity of 355 cells was recorded in the auditory thalamus of anesthetized cats before, during, and after the inactivation by cooling of the ipsilateral primary auditory cortex (AI). Most of the units (n = 288) showed similar functional characteristics of firing before and after the cryogenic blockade of AI. The spontaneous firing rate remained unchanged by cooling in 20% of the units and decreased in the majority of them (60%). In some regions, i.e. dorsal division of the medial geniculate body (MGB), lateral part of the posterior group of the thalamus, and auditory sector of the reticular nucleus of the thalamus, the maximum firing rate evoked by white noise bursts was generally affected by cooling in the same direction and to the same extent as the spontaneous activity. Units in the ventral division of MGB showed a characteristic increase of signal-to-noise ratio during cortical cooling. The corticofugal modulation led to the appearance or disappearance of the best frequency of tuning in 51 units and changed it by more than 0.5 octave in 34 units. The bandwidths of different response patterns to pure tones stimulation were used to define a set of functional properties. During cryogenic blockade of AI, two cortically modulated sub-populations of units were usually distinguished that exhibited changes for a given functional property. The complexity and diversity of the effects of cortical inactivation suggest that the corticothalamic projection may be the support for selective operations such as an adaptive filtering of the incoming acoustic signal at the thalamic level adjusted as a function of cortical activity.     

Predicting Survival after Trauma: a Comparison of TRISS and ASCOT in the Netherlands

Background: Evaluating the performance of a trauma system may be attempted by comparing outcome in different trauma populations. Controlling for injury severity is a necessity for such evaluations. We compare two current models for doing so: the “Trauma and Injury Severity Score” (TRISS) and “A Severity Characterization Of Trauma” (ASCOT). Material and Methods: This study of high-energy trauma victims took place in Leiden, the Netherlands, between 1993 and 1998. Using the Hosmer-Lemeshow (HL) test and receiver operator characteristic (ROC) analysis, the TRISS and ASCOT models were compared for calibration and discrimination. Results: 1,024 patients, with an average Injury Severity Score (ISS) of 13.5, were eligible for inclusion. Blunt trauma was the predominant cause of injuries. Both models gave accurate, though pessimistic, results in predicting the actual number of fatalities (n = 71). The HL test indicated a sufficient fit for the ASCOT model (p = 0.28) and an insufficient fit (p = 0.02) for TRISS. The ROC curves were nearly identical (0.97). Including age as a linear variable, instead of using the current age groups, resulted in an improved discriminative power of the models. Conclusions: The ASCOT model proved superior over TRISS in its accuracy to estimate of survival chances. This difference was most evident for victims with an estimated survival chance of 60–90%. Future national trauma researchers should therefore collect ASCOT data. Improved ASCOT models could be developed, with age as a linear variable. Received: April 25, 2002; revision accepted: September 17, 2002 Correspondence Address Prof. Arie B. van Vugt, MD, PhD, Department of General Surgery and Traumatology, Erasmus MC Rotterdam, Dr. Molewaterplein 40, Postbus 2040, 3000 CA Rotterdam, The Netherlands, Phone (+31/10) 463-5735, Fax -4757, e-mail: vanvugt@hlkd.azr.nl     

基于人工嗅觉的呈香物质识别方法

研究了人工嗅觉在物质识别中的应用，概述了使用模式识别辨别物质气味的基本原理，详细介绍了人工嗅觉系统的硬件设计，算法和软件实现方法，最后使用本系统对不同香气物质进行了识别，取得了较好的结果。     

老年人高粘滞血症预防的初步探讨

本文报告对32例60岁以上健康老年人预防高粘滞血症的观察结果.经采取综合预防措施六年,血流变学检测表明:全血(比)粘度、血浆(比)粘度、血沉、红细胞压积均低于对照组,统计学处理表明,前三项指标P值均小于0.01,因此达到了对老年人高粘滞血症的预防目的.     

Characteristic modifications of the breathing pattern of mice to evaluate the effects of airborne chemicals on the respiratory tract

A system was developed for exposure of unanesthetized mice to airborne chemicals and for continuous measurement of their breathing pattern prior to, during and following exposure. By measuring inspiratory and expiratory airflows (VI and VE), and integration with time to yield tidal volume (VT), we obtained characteristic modifications to the normal breathing pattern. These permitted recognition that a specific portion of the respiratory tract was affected by the selected airborne chemicals. Following recognition, we also quantitated the degree of effect using one specific measurement in each case. An effect on the upper respiratory tract, induced by the sensory irritant, 2-chlorobenzylchloride, was quantitated by measuring a decrease in respiratory frequency. An effect on the conducting airways, induced by the airway constrictor, carbamylcholine, was quantitated by a decrease in VE at the mid-point of VT. An effect at the alveolar level, induced either by the vagal nerve ending stimulant, propranolol, or by the pulmonary irritant, machining fluid G, was quantitated by an increase in the length of a pause induced at the end of expiration. The system is easy to construct and operate and can be used to rapidly evaluate the effects of airborne chemicals on the respiratory tract.     

Variability of the pattern electroretinogram

Conflicting results have been obtained concerning the parametric properties of the pattern electroretinogram. These discrepancies may be due to the large amount of variability inherent in recording amplitudes. We have found the variability within a single stimulus condition to be so large (ranging from 30% to 67% of the mean value) that it could mask any underlying spatial frequency tuning. Changing the stimulus conditions failed to significantly reduce the observed variability, although changing recording conditions produced some reduction. The use of a narrower rejection band, a greater number of sweeps, and placement of the reference electrode on the ipsilateral ear (as opposed to the ipsilateral temple) combined to decrease variability of the pattern electroretinogram within a single recording session; however, intersession variability remained high. Therefore one must be careful in evaluating data from this technique, and caution is advised in its clinical use.     

Influence of the mother-child relationship on the development of the Type A Behavior Pattern

Investigation of the Type A Behavior Pattern (TABP) of pre-school children was conducted to determine the influence of the mother-child relationship on the development of TABP. The incidence of TABP was 44.2% (51.7% in boys and 38.7% in girls). The TABP tendency of the boys decreased as the manifest dissension or conflict in the family grew, in marked contrast with the tendency seen in girls, suggesting that conflict in the family can either weaken or reinforce TABP.     

Obsessive-compulsive disorder: admission patterns and diagnostic stability

All first-time admissions from 1970 to 1986 with obsessive-compulsive neurosis (OCD) (ICD-8 diagnosis number 300.39) or obsessive-compulsive personality disorder (OCPD) (ICD-8 diagnosis number 301.49) were analyzed based on an extract from the nationwide Psychiatric Case Register in Denmark. All patients with secondary diagnoses other than neurotic disorders or personality disorders (including “neuroses characterogenes”) were excluded from the study. A total of 284 patients were first-time admitted with a main diagnosis of OCD during the period. The sex ratio was 0.67 (males/females). A total of 126 were first-time admitted with a diagnosis of OCPD, with a sex ratio of 1.18 (males/females). Seventy-seven percent of the readmitted patients with a first-time diagnosis of OCD kept a diagnosis within the “emotional spectrum” at the last admission. About half kept OCD as a main diagnosis, whereas only 15% shifted to a severe psychiatric diagnosis such as schizophrenia or manic-depressive psychosis. Of the readmitted patients with OCPD. 13% later developed a diagnosis of manic-depressive psychosis.     

The synchronization of respiration and swallow sounds with videofluoroscopy during swallowing

Simultaneous recording of adult subjects sipping small amounts of fluid from a cup have been obtained by videofluoroscopy together with feeding respiratory patterns and swallow sounds from the Exeter Dysphagia Assessment Technique (EDAT). These allowed visual representations of respiration and swallow sounds to be superimposed on a videofluoroscopy recording using a split-screen technique. Sequentially numbered, 1/50 sec, half-frame photographic prints were examined and schematic drawings of the relevant radiographs were made. These were superimposed on to the actual EDAT printed chart of the same swallow event, theri exact time relationship with respiration and cervical swallow sounds being preserved. The results allow events in the barium videofluoroscopy to be related to events in the feeding respiratory pattern and swallow sounds recorded by EDAT.     

活动翼矫治器的研制与初步应用

目的评价活动翼矫治器的设计原理与矫治效能。方法应用活动翼矫治器对588例错畸形病例进行矫治。对2001年～2004年的389例进行研究,分析其疗效、疗程、复诊次数、弓丝使用等情况。结果病例完成时间为4～15个月,平均为8.13个月。复诊次数4～13次,平均7.55次。平均每例上颌使用弓丝1.95根、下颌1.98根。仅11例病例使用口外支抗。结论活动翼矫治器是一种新研发的高效能矫治器,能够明显缩短疗程、减少复诊次数、减少弓丝用量