Acetylcholine produces stimulus-specific receptive field alterations in cat auditory cortex

Frequency receptive fields (RFs) were determined before and after pairing iontophorectic administration of acetylcholine (ACh) with a repeated single-frequency stimulus in the auditory cortex of barbiturate-anesthesized cats. In 58% of the cells, the paired ACh + tone treatment produced subsequent alterations of frequency RFs. In half of these cases, the RF modifications were highly specific to the frequency that had been paired with ACh. Atropine antagoized the frequency-effects of ACh, suggesting that they were mediated via muscarinic cholinergic receptors.     

High-protein Weight-loss Diets: Are They Safe and Do They Work? A Review of the Experimental and Epidemiologic Data

Recommendations for increased consumption of protein are among the most common approaches of popular or fad diets. This review summarizes the effects of dietary protein on satiety, energy intake, thermogenesis, and weight loss, as well as its effect on a variety of health outcomes in adults. In short-term studies, dietary protein modulates energy intake via the sensation of satiety and increases total energy expenditure by increasing the thermic effect of feeding. Whereas these effects did not contribute to weight and fat loss in those studies in which energy intake was fixed, one ad libitum study does suggest that a high-protein diet results in a greater decrease in energy intake, and therefore greater weight and fat loss. In terms of safety, there is little long-term information on the health effects of high-protein diets. From the available data, however, it is evident that the consumption of protein greater than two to three times the U.S. Recommended Daily Allowance contributes to urinary calcium loss and may, in the long term, predispose to bone loss. Caution with these diets is recommended in those individuals who may be predisposed to nephrolithiasis or kidney disease, and particularly in those with diabetes mellitus.     

Monitoring of skin response to sodium lauryl sulphate: clinical scores versus bioengineering methods

The present trial was designed to evaluate clinical scores (single observer) of sodium lauryl sulphate (SLS)-induced skin irritation in a group of subjects (n = 10) over a 10-day period along with various skin function parameters. In order to avoid significant variations due to secondary phenomena, the following parameters were recorded with non-invasive instruments in this order: skin capacitance (C1; arbitrary units; CM420 Corneometer), transepidermal water loss (TEWL; g/m2.h; Evaporimeter) and laser Doppler flowmetry (CBFV: cutaneous blood flow values; Periflux). All examinations were performed during winter on reclined relaxed subjects present for at least 10 min in a test room with controlled temperature and relative humidity (t degrees: 19.5-20.7 degrees C and RH: 47.3-60.3%). The analysis of differential data (delta = value at tx-value before test; 2-way ANOVA) was made on single parameters as a function of site (volar forearm versus neck) and time (from 24 h after 48-h occlusion with 5% SLS up to 10 days later). The profile of erythema scores over time differed between neck and forearm, but the delta CBFV readings with the laser Doppler instrument did not detect significant site-time interactions. Roughness (blind evaluation with palpating finger) and capacitance readings (delta C1) showed significant differences between sites, but the profile over time was similar in both locations. delta TEWL did not differ according to anatomical location. The reason for different erythema scores on neck and forearm might be related to inherent regional variation of optical properties of the skin or to a substantial contribution of SLS-induced roughness to the readings of erythema.(ABSTRACT TRUNCATED AT 250 WORDS)     

Integrinα4在骨肉瘤中的表达与意义

Objective： To investigate the expression of integrin α4 in osteosaxcoma and significance. Methods- Forty-six patients with osteosarcoma （Enneking Ⅰ-Ⅲ） were analyzed for the expression of α4 integrin subunit using immunohistochemical method. Results： Twenty-nine （63.04%） of 46 samples demonstrated positive （＋-＋＋） integrin α4 expression. Loss expression of integrin α4 was observed in the patients with advanced Enneking stage （P=0.0040） and with metastatic disease at presentation （P=0.0158）. Integrin α4 expression correlated with cell differentiation, the level of malignancy and the invasive behavior of osteosaxcoma. Conclusion： The loss expression of integrin α4 subunit might be a predictor indicating the invasive potential of osteosarcoma and play a role in metastasis of osteosaxcoma patients.     

Overactive bladder in Parkinson's disease: alteration of brainstem raphe detected by transcranial sonography

Urinary dysfunction is very common in idiopathic Parkinson's disease (PD) and manifests primarily with symptoms of overactive bladder (OAB). Affection of central serotonergic systems has been suggested to play a role in OAB. The objective of this study was to evaluate whether in PD patients with OAB symptoms a specific alteration of the brainstem raphe (BR), which contains serotonergic neurons, can be detected with transcranial sonography (TCS). Of 116 PD patients enrolled, 19 had PD-related OAB symptoms (OAB+) unlike remaining 97 patients (OAB−). Patients were examined by a sonographer blinded to the clinical data. Reduced echogenicity of BR was found in 12 (63%) OAB+ patients but only in 18 (19%) of 93 assessable OAB− patients (Mann–Whitney U -test, P  < 0.001). In OAB+ patients, lower raphe echogenicity score was associated with longer duration of OAB symptoms ( anova , P  = 0.033). Other TCS findings such as echogenicity of substantia nigra, thalami, lenticular and caudate nuclei, and widths of third and lateral ventricles did not differ between OAB+ and OAB− patients. TCS findings suggest a pathogenetic role of BR in OAB related to PD. Alterations may reflect disturbance of its central serotonergic system.     

Synaptic potentials and effects of amino acid antagonists in the auditory cortex

Neurons of in vitro guinea pig and rat auditory cortex receive a complex synaptic pattern of afferent information. As many as four synaptic responses to a single-stimulus pulse to the gray or white matter can occur; an early-EPSP followed, sequentially, by an early-IPSP, late-EPSP, and late-IPSP. Paired pulse stimulation and pharmacological studies show that the early-IPSP can modify information transmission that occurs by way of the early-EPSP. Each of these four synaptic responses differed in estimated reversal potential, and each was differentially sensitive to antagonism by pharmacological agents. DNQX (6,7-dinitroquinoxaline-2,3-dione), a quisqualate/kainate receptor antagonist, blocked the early-EPSP, and the late-EPSP was blocked by the NMDA receptor antagonist APV (D-2-amino-5-phosphonovalerate). The early-IPSP was blocked by the GABA-a receptor antagonist bicuculline, and the late-IPSP by the GABA-b receptor antagonists 2-OH saclofen or phaclofen. Presentation of stimulus trains, even at relatively low intensities, could produce a long-lasting APV-sensitive membrane depolarization. Also discussed is the possible role of these synaptic potentials in auditory cortical function and plasticity.     

大鼠脑干缺血模型制备及早期超微结构观察

目的:制备脑干缺血动物模型并观察大鼠脑干缺血后早期组织学病理的超微结构。方法:应用两点电凝基底动脉的方法制作鼠脑干缺血动物模型。结果:病理学观察发现脑干缺血2小时即可出现超早期病理变化,并随时间的延长缺血性损害逐渐加重。结论:两点电凝基底动脉后可以造成稳定的脑干缺血,对急性脑干缺血的病理学研究有一定的价值。     

听性脑干反应和听觉相关电位测试对聋儿听力的评估

目的:探讨听性脑干反应(ABR)和40 Hz听觉相关电位(40Hz AERP)测试的相关性及对聋儿听力评估的重要性。方法:对401例6岁以下聋儿行ABR和40Hz AERP测试并比较。结果:ABR测试无反应者为589耳(73.4％),40 Hz AERP测试无反应者为311耳(19.4％),前者明显高于后者(P<0.01)。两种测试中有残余听力的耳数随阈值的升高,检出率亦升高,结论:ABR测试只反映高频听阈,无反应率高,而40 Hz AERP可显示低、中频的听阈,无反应率低。两种测试应同时进行,可全面了解聋儿的听力损失情况。同时因聋儿多为重度聋,更应及早选配助听器。