运用反应时探究小学生情绪认知发展特点

目的：探究小学儿童情绪认知的发展特点。方法：采用计算机实验方法和反应时评价指标，运用80对情绪词汇推测小学儿童对四个不同类别情绪（基本积极情绪、基本消极情绪、积极自我意识情绪、消极自我意识情绪）的认知发展差异，以及对引发情绪的原因、情绪的外在行为反应、情绪的后继调节三个维度的认知发展差异。结果：小学儿童对引发情绪的原因、外在行为反应、后继调节三个维度的反应时差异有统计学意义（1289．5、1164．6、1295．7，F=13．535，P〈0．001），且三个维度认知反应时2年级学生均长于4、6年级（P〈0．01），对四个不同类别情绪认知的反应时差异无显著性（1237．1、1269．8、1222．8、1305．2，F=1．520，P=0．220），四个类别的情绪认知反应时2年级均长于4、6年级（P〈0．01）。结论：儿童对情绪行为认知的加工速度最快，对消极自我意识认知的发展相对较慢，且均在2—4年级间发展迅速。     

股骨颈骨折几种闭合复位方法的评价(译文)

在股骨颈移位骨折的治疗中,试用了7种不同的闭合复位方法。其中Whitman's法在骨折床台上进行,正常肢体外展,患肢由屈曲牵引至完全伸直位后,维持牵引并外展到与对侧肢体相称位,单髋人字石膏外固定(1914年)。 Leadbetter's法也在骨折床台上进行。将患肢髋部屈曲90°,沿大腿轴线行手法牵引。同时股骨干稍内收,患肢缓慢行环形活动至外展、内旋位,患肢向下降至骨折床台面时,行跟掌试验以验证是否完全复位(1933年)。 Bozan's法利用骨折床台使双下肢维持在伸直位,大绷带放置在患肢髂嵴部位,小绷带放置在患肢腹股沟皱襞最高点处实施牵引。然后整个患肢极度内旋,在维持侧方牵引的同时,患肢外展并轻度过牵(1934年)。     

Vasorelaxant Effects of Clearfil SE Bond and Clearfil S3 Bond Mediated by Calcium Antagonistic Action

Dental adhesives can alter the contractility of vascular tissue via different mechanisms. The aim of this study was to investigate and compare the vascular action of two self-etch adhesive systems, Clearfil SE Bond (CSEB) and Clearfil S³ Bond (CS3B). Responses of isolated rat thoracic aorta rings were recorded isometrically by force displacement transducers. Following pre-contraction of aorta rings, relaxations to the independent and mixed components of CSEB and CS3B were recorded in the absence and presence of nitric oxide synthase (NOS) inhibitor (N ^ω -nitro-L-arginine methyl ester (N-LAME)), cyclooxygenase (COX) inhibitor (indomethacin) and K⁺ channel inhibitors (tetraethylammonium, glibenclamide and 4-aminopyridine). We also tested the effects of CSEB and CS3B in endothelium-intact and -denuded rat thoracic aorta rings. To investigate the Ca²⁺-channel antagonistic effect of adhesive components, concentration–response curves to CaCl₂ were obtained in the absence and presence of the components. The primer, the bond, and the mixture of CSEB and CS3B elicited concentration-dependent relaxations. Mechanical rubbing of the endothelium did not significantly modify the extent of vasorelaxation induced by the test materials. The vasorelaxant effect was mediated neither by NOS and COX inhibition nor by the tested K⁺ channel antagonists. Mechanical removal of the endothelium did not alter the vasodilatory effect induced by the self-etch adhesives. Both CSEB and CS3B significantly inhibited the contractions induced by CaCl₂. These results demonstrate the vasodilatory effect induced by the self-etch adhesive systems through a Ca²⁺-antagonistic effect.     

Age-related changes in the distribution of Kv1.1 and Kv3.1 in rat cochlear nuclei

Abstract

Objectives: To identify age-related changes in voltage-gated K⁺ (Kv) channels that contribute to temporal processing in neurons of the central auditory system, we investigated the distribution of Kv1.1 and Kv3.1 in the auditory brainstem of adult and aged rats.

Methods: Immunohistochemistry was performed in accordance with the free-floating method described earlier.

Results: Among the auditory nuclei, only the posterior ventral cochlear nucleus (PVCN) showed age-related changes. Kv1.1 immunoreactivity was increased in the octopus cell bodies, while the staining intensity was significantly decreased in the neuropil. Image analysis demonstrated the specific increase in Kv1.1 immunoreactivity in aged cochlear nucleus neurons although the mean density of the entire selection was significantly decreased. In contrast, the number of Kv1.1-immunoreactive neurons was not significantly different between control and aged groups. The immunoreactivity for Kv3.1 was decreased in the octopus cells and neuropil of aged PVCN, which was confirmed by image analysis. The number of Kv3.1-positive cells was also significantly decreased in aged PVCN.

Discussion: This study may provide useful data to compare age-related changes in Kv1.1 and Kv3.1 with known physiological properties of auditory neurons.     

Endoscopic technique: A new model of subarachnoid hemorrhage in rats

Abstract

It has become increasingly evident that the pathophysiology of cerebral vasospasm following subarachnoid hemorrhage (SAH) which described the ischemic consequences of cerebral arterial constriction is complex and multifactorial. In an attempt to study cerebral vasospasm, numerous investigators have used experimental animal models that resemble cerebral vasospasm in humans. No ideal model for SAH has been found as yet, and hence the quest for such a model continues. We developed an endoscopic technique that permits a direct vision of internal carotid artery and puncturing the artery to provoke SAH. This model will closely reflect the clinical setting of an aneurysm rupture. The onset of SAH was characterized by a sudden decrease of cerebral blood flow (CBF) and cerebral blood volume (CBV) by at least 40% in the first 20 min. Following this initial drop, there was an increase in the CBF and the CBV, however, they remained significantly below the base line values, at the end of 1 h. This study describes a new model of SAH in rat that simulates the clinical phenomenon of ruptured intracranial aneurysm that also produces cerebral vasospasm. [Neurol Res 2001; 23: 627-630]     

Improved rat model for cerebral vasospasm studies

Abstract

While the rat has been used extensively in subarachnoid hemorrhage (SAH)-cerebral vasospasm studies, concerns exist whether this animal represents a usable model because its time course and pattern of cerebral vasospasm following SAH is not comparable to that observed in man. At present, our knowledge of the rat model is based almost exclusively on studies using a 'single hemorrhage' method. Since there is a positive correlation between severity of cerebral vasospasm, and volume of subarachnoid blood, an obvious question is whether the rat will show modifications in vascular responses when insulted by a second SAH. Here, an SAH was produced in rats using a 'double hemorrhage' method. Following SAH, cerebral arteries showed pathological alterations, significant decreases in luminal perimeter, and increases in arterial wall thickness, over a 7-day post-SAH period. The above vascular features are considered to be indicative of cerebral vasospasm and their presence over a 7-day post-SAH period represents a significant time extension when compared to a single hemorrhage. These modified vascular responses made the double hemorrhaged rat a much-improved animal model. [Neurol Res 2001; 23: 761-766]     

Recombinant or Plasma-Derived Antisecretory Factor Inhibits Cholera Toxin-Induced Increase in Evans Blue Permeation of Rat Intestinal Capillaries

The effect of cholera toxin on small intestinalcapillary function, utilizing the Evans blue dye method,was analyzed. The modulatory influence of plasma-derivedor recombinant human antisecretory factor on this variable was also investigated. MaleSprague-Dawley rats were briefly anesthetized withether, and a jejunal loop was constructed that waschallenged for 90 min with phosphate-buffered saline or cholera toxin. Five minutes prior to death, therats received an intravenous injection of Evans blue.The tissue content of dye in the loop was quantitatedspectrophotometrically or demonstrated histochemically. Cholera toxin increased the recovery of Evansblue; extravasation of the dye was prominent in the topof the villi, while the crypts were spared. It issuggested that the toxin caused increased transcapillary permeation of albumin in a heterogenous fashionin the gut wall. This effect of the toxin was preventedby pretreatment with the antisecretory factor.     

Effect on Gastric Emptying and Weight Reduction of Botulinum Toxin-A Injection into the Gastric Antral Layer: An Experimental Study in the Obese Rat Model

Background: We investigated the effects of Botox-A on weight loss and gastric emptying in an experimental obese rat model. Although there is evidence of weight loss in normal-weight rats after Botox-A injection, there are no studies indicating the effect of Botox-A injection on weight loss and gastric emptying time in obese rats. Methods: 37 female Wistar Albino rats were given high calorie diet for 90 days. They were separated into 3 groups. The first group (Botox group) consisted of 15 obese rats whose gastric antrum was injected with 20 U of Botulinum Toxin Type A. The second group (Saline group) consisted of 15 obese rats whose gastric antrum was injected with 20 U of saline. The third group (Control group) had no surgical intervention. Gastric scintigraphy was performed in the 3 groups pre- and postoperatively. Results: The saline group had a weight reduction in the early postoperative days but began to gain weight thereafter. The mean weight of the Botox group between the 16th and 28th days postoperatively was significantly lower than the mean weights of the control and the saline groups (P<0.05, P<0.001). The results of gastric emptying scintigraphy in all 3 groups at day 20 revealed significantly higher T1/2 values in the Botox-A group when compared to the results of the control and saline groups (P<0.001). Conclusion: Botox-A application to the gastric antrum in obese rats leads to weight loss by increasing the gastric emptying time.     

Effects of pregnancy on insulin receptor in liver,skeletal muscle and adipose tissue of rats

The mechanism responsible for insulin resistance during pregnancy remains unclear. Considerable evidence indicates that the insulin receptor plays an important role in insulin sensitivity. It seems possible that the hormonal milieu during gestation could have an effect on the insulin receptor. In the present study, measurements of tyrosine phosphorylation and protein content of the insulin receptor and expression of its gene in liver, skeletal muscle and adipose tissue indicate that during pregnancy significant changes occur in these parameters. We found that at the end of early gestation (day 10), muscle and adipose tissue are very sensitive to insulin action because the amount, phosphorylation and gene expression of insulin receptor is higher than in late gestation (days 15–20), while the tissue which is most sensitive to insulin action in late gestation is the liver. Our hypothesis is that these results are connected with changes in the concentrations of estradiol and progesterone observed during pregnancy. In conclusion, our previous and present findings seem to demonstrate that the different concentrations of gestational hormones play an important role in insulin sensitivity in this period and that each tissue responds in the most appropriate manner to guarantee the gestation in its entirety.