The Dynamics of the Weighting and Topographical Characteristics of the Excitatory Zones of the Receptive Fields of Neurons in the Cat Visual Cortex

Acute experiments on 22 anesthetized and immobilized cats used a time slice method to study changes in the maps of 83 on and/or off receptive fields in 47 neurons in field 17 of the visual cortex. The latent period of the appearance of the receptive field averaged 88 ± 5 msec and its persistence time was 192 ± 12 msec. During generation of responses, the area and weighting on the one hand and the location of its discharge center on the other, changed in a wavelike fashion up to three times in all the neurons studied, the duration of each wave averaging 95 ± 4 msec. The discharge center of the receptive field moved in a wavelike manner in 99% of cases, moving towards and away from the center of the overall map with a period of 67.3 ± 3 msec. In 72.5% of neurons, movement of the discharge center occurred via different trajectories, which were ellipses. The functional significance of changes in the receptive fields of striate neurons in relation to the dynamics of their detector properties are discussed, as are the possible mechanisms of these rearrangements.     

The place of premedication in pediatric practice

Behind the multiple arguments for and against the use of premedication, sedative drugs in children is a noble principle that of minimizing psychological trauma related to anesthesia and surgery. However, several confounding factors make it very difficult to reach didactic evidence-based conclusions. One of the key confounding issues is that the nature of expectations and responses for both parent and child vary greatly in different environments around the world. Studies applicable to one culture and to one hospital system (albeit multicultural) may not apply elsewhere. Moreover, the study of hospital-related distress begins at the start of the patient's journey and ends long after hospital discharge; it cannot be focused completely on just the moment of anesthetic induction. Taking an example from actual practice experience, the trauma caused by the actual giving of a premedication to a child who absolutely does not want it and may struggle may not be recorded in a study but could form a significant component of overall effect and later psychological pathology. Clearly, attitudes by health professionals and parents to the practice of routine pediatric premedication, vary considerably, often provoking strong opinions. In this pro–con article we highlight two very different approaches to premedication. It is hoped that this helps the reader to critically re-evaluate a practice, which was universal historically and now in many centers is more selective.     

学龄前儿童普通话平均句子长度的多因素研究

【目的】探讨影响学龄前儿童普通话平均句子长度的因素,为促进儿童语言发育提供参考意见。【方法】以65名3~6岁学龄前儿童为研究对象并对其父母进行问卷调查。问卷内容包括儿童发育情况、家庭社会环境因素等39个变量。利用计算机程序计算每名儿童自然语言样本的平均句子长度。【结果】年龄、边看图书边自己讲述、父亲的文化程度、看广告、看电视后家长(或保姆)与儿童谈论电视内容与学龄前儿童平均句子长度呈正相关;边看图书边听家长讲述和语言障碍家族史与学龄前平均句子长度呈负相关。【结论】年龄、遗传因素和家庭语言环境为学龄前儿童语言发育的重要影响因素。     

IN.PACT AV access randomized trial: Japan cohort outcomes through 12 months

Purpose

There is a lack of adjudicated and prospectively randomized published outcomes on the use of drug-coated balloons (DCB) to treat dysfunctional arteriovenous fistula in Asian patients. This post hoc subgroup analysis of 112 Japanese participants from the global IN.PACT AV Access trial reports outcomes through 12 months.

Materials and Methods

Participants were treated with DCB (n = 58) or standard non-coated percutaneous transluminal angioplasty (PTA) balloons (n = 54). Outcomes included target lesion primary patency (TLPP), access circuit primary patency, and safety.

Results

Through 6 months, TLPP was 86.0% (49/57) in the DCB group and 49.1% (26/53) in the PTA group (p < 0.001). Through 12 months, TLPP was 67.3% (37/55) in the DCB group and 43.4% (23/53) in the PTA group (p = 0.013).

Conclusion

In this post hoc analysis of Japanese participants from the IN.PACT AV Access trial, participants treated with DCB had higher TLPP through 6 and 12 months compared with PTA.     

Tuning to Y-like figures in the cat striate neurons

Sensitivity to symmetric or asymmetric Y-like figures and crosses of different shapes and orientations flashed in the receptive field was studied in 101 neurons of the cat striate cortex (area 17) and compared with their orientation tuning to a single light bar. Selective sensitivity to the Y-like figure (figure/bar response ratio more than 1.25) was found in 78/101 neurons (77.2% of cases) and to the cross-in 54/101 units (53.4%). In 62.5% of neurons with sensitivity to both figures, sensitivity to the Y-like figure was higher than to a cross. Tuning to Y-like figure was typically (60%) selective to both its shape and orientation. The remaining Y-like selective neurons exhibited invariant tuning to orientation and/or shape of the figure. The preferred angles between two lines of Y-like figures were distributed in the range of 22.5-157.5 degrees with slight preference to 90 degrees, while crosses of 45 degrees and 90 degrees angles were preferable. Response magnitudes to a single bar, a Y-like figure and a cross were positively correlated. Possible mechanisms and functional implication of the striate sensitivity to Y-like figures are discussed.     

Interrelation of tuning characteristics to bar, cross and corner in striate neurons

Characteristics of responses and background activity, as well as of tuning to a single bar orientation and to cross or corner shape and orientation have been compared in one third (561174) of neurons in the cat striate cortex. Shortening of the response latency to cross vs bar, to corner vs bar and to corner vs cross was revealed in most of the units studied. Direct correlation between the response and tuning characteristics for bar, cross and corner was revealed: units with better tuning to one type of stimulus were typically better tuned to the other types of stimuli. At the middle cortical depth (700-1200 microm from the surface) we found a reliable improvement of response magnitude and latency, cross/bar response ratio and selectivity of tuning in comparison with more superficial and deeper layers. Although we could not find a direct correlation between characteristics of tuning to figures and the type of the receptive field (simple, complex or hypercomplex), our data pointed to a lower cross/bar ratio and selectivity of tuning in the units with small receptive fields. The functional implication of neuronal sensitivity to cross and corner and possible meaning of correlation between their functional characteristics are discussed.     

Immunosuppressive therapy with the use of cyclosporin A in the late period after a kidney transplant]

A study was made of the results of kidney transplantation in 90 patients who received three-component immunosuppressive therapy (cyclosporin, azathioprine and prednisolone) in the induction phase, followed by cyclosporin conversion in the phase of maintenance therapy. The second patients' group (39 cases) received permanent three-component immunosuppressive therapy. Analysis of the data obtained makes it possible to regard the use of cyclosporin advisable not only in the induction, but also in the maintenance phases of immunosuppressive therapy.     

农村乙型肝炎疫苗接种率及影响因素调查

为了解农村地区乙型肝炎 (乙肝 )疫苗免疫效果及影响因素 ,提出相应措施提高乙肝疫苗的保护效果。在南江、旺苍两县 ,采用多阶段随机整群抽样方法 ,抽取 5 2 7名 2 0 0 0年出生儿童及其 4 99名母亲 ,采血检测血清乙肝病毒表面抗原 (HBsAg)。结果显示 :儿童乙肝疫苗免疫接种率和全程免疫接种率分别为 99 0 5 %、95 4 5 % ;首针及时接种率和全程及时接种率分别为 6 8 39%、6 1 6 9%。住院分娩和在家分娩儿童首针及时接种率分别为 83 5 9%、5 6 90 % ,两者的差异有非常显著的统计学意义 (P <0 0 1)。≥第 2胎儿童的首针及时接种率非常明显的低于第 1胎儿童 (χ2 =34 1178,P <0 0 1)。被调查儿童母亲的HBsAg阳性率为 6 6 1% ;儿童HBsAg阳性率为 1 5 2 % ,7例均为阳性母亲所生儿童。由此可见 ,在农村推广乙肝疫苗免疫接种将大大降低HBsAg阳性率。在经济欠发达的边远地区和山区农村 ,对孕妇进行HBsAg筛查 ,重点对HBsAg阳性产妇的新生儿及时接种乙肝疫苗 ,将会取得事半功倍的效果