Reflections on experimental and human pathology of aggression

On the basis of the already proposed distinction between "normal" and "pathological" aggression in laboratory animals, it is essayed an integration of the experimental findings derived from a specific animal model of aggression with the available clinical information on human violent behavior. The too disregarded importance of the role played by the inhibitory control of brain functions, appears instead reportedly essential in the regulation of emotions and behavior, and is of great relevance in explaining the behavioral changes that follow induced or spontaneous impairment of the serotonergic system of the brain. As a matter of fact, the numerous evidences indicate that genetic predisposition and induced or acquired defects of serotonergic inhibitory control greatly concur to precipitate anomalous strong aggression. Interestingly, the cluster of symptoms presented by laboratory rats in consequence of the serotonergic discontrol, has many unexpected similarities with several pathological conditions of man. This fact confers to laboratory experiments the value of a tool aimed at a better understanding of the biological mechanisms which underlie corresponding alterations of human conduct, with special reference to pathological aggression and violence. In this line, some specific nutrient defects and/or malabsorption conditions can be important in the facilitation or elicitation of mental illness including human aggression. In addition, the efficacy and neurochemical action of those substances capable to partially or completely block or prevent experimental aggression, will likely assume equal relevance in the management or prevention of human violent behavior.     

蠕变局部损伤开裂的有限元模型

建立了蠕变局部损伤法模型,并给出单元进入损伤态的判据和失效的临界拉伸应变条件,局部蠕变损伤理论的实质就是试样是多种不同蠕变性能材料的统一,并由蠕变应力再分布得到证实,应用有限元对双缺口圆试样作了蠕变局部损伤分析,启裂时间和断裂蠕变应变值均与实验结果相吻合。     

中脑导水管周围灰质内注射抗强啡肽血清对神经降压素镇痛作用的影响

目的：探讨大鼠中脑导水管周围灰质（PAG）内内源性强啡肽对神经降压素（NT）镇痛作用的影响。方法：以钾离子透入法引起大鼠甩尾反应的电流强度（mA)为痛行为反应的指标,观察向PAG内注入NT,抗神经降压素血清和抗强啡肽A1－13血清对动物痛阈的影响。结果：PAG内注入NT后,大鼠痛阈明显升高;注入抗神经降压素血清后,大鼠痛阈则明显降低,而注入抗强啡肽血清后,对NT的镇痛效应无显著影响,结论：PAG内NT在痛觉调制中发挥着重要的作用,且其作用不依赖于PAG内的内源性强啡肽。     

仁术健胃颗粒逆转胃癌前期病变的临床研究

目的观察仁术健胃颗粒对胃癌前病变的逆转作用。方法将１２０例符合诊断标准的胃癌前期病变患者,随机分为仁术健胃颗粒治疗组８０例和胃复春对照组４０例进行临床疗效观察。结果①综合疗效：治疗组总有效率为９１．２５％,对照组为７５．００％,经统计学处理,差异有显著性（Ｐ〈０．０５）;②治疗组胃镜及对萎缩、肠化、异型增生的疗效分别为７１．２５％、７７．５０％、７９．４９％、８８．４６％,对照组为５２．５０％、６     

Effect of adeno-tonsilectomy on hearing threshold and middle ear pressure

Out of 50 children (100 ears) undergoing adeno-tonsillectomy, 34 ears had hearing threshold 20–50 dB (20dB is normal) and 32 ears showed negative middle ear pressure of 100 to 400 mmH₂O (100 mmH₂O is normal). Post-operatively only 7 ears had hearing threshold of 20–30 dB and negative middle ear pressure of 100 to 200 mmH₂O. Thus adenoidectomy improves eustachian tube functions.     

Laser energy threshold for thermal vascular injury in a port-wine stain skin model

Monte Carlo simulation of laser energy deposition in a port-wine stain (PWS) skin model and numerical solution of the thermal diffusion equation have been used to calculate threshold energies for thermal injury of PWS blood vessels for different vessel sizes and laser pulse durations. It has been assumed that an average vessel temperature rise of 65 C causes thermal injury to the blood vessel. The result is that for a certain combination of wavelength, pulse duration and incident energy density, only a limited range of blood vessel sizes can be injured optimally. Higher energy densities are required to injure smaller vessels with the same pulse duration, spot size and wavelength. This gives support to the mechanisms of selective photothermolysis suggested previously by Anderson and Parrish, although their model was based on the cooling behaviour of instantaneously heated vessels. The authors hypothesize that different laser parameter settings that match the individual PWS vessel anatomy during treatment will be used in the future, instead of many treatments with the same laser parameters. This could lead to less treatment sessions and to an improved predictability of clinical results.     

Is the retractile testis a normal,physiological variant or an anomaly that requires active treatment?

Conventional teaching states that the retractile testis is a normal, physiological variant that descends spontaneously by puberty and requires no active treatment. Critical review of the literature, however, suggests that this complacent view may be inappropriate. Substantial overlap exists between the three seemingly separate entities of the late descending, the ascending and the retractile testes. This overlapping group probably accounts for the recently observed increased incidence of orchidopexies. Retractile testes that spend most of the time in an extrascrotal position are subject to the same adverse effects of higher temperatures as true undescended testes, regardless of whether they can be manipulated into the scrotum; what matters is where they actually reside most of the time. The evidence suggests that such retractile testes suffer similar pathological changes to true undescended testes if left to await spontaneous descent. Evidence is presented to support a radical, novel proposal that the retractile testis is a variant of the spectrum of pathological maldescended testes and requires active treatment. A new strategy is proposed for the management of this common pathology. Correspondence to: D. W. Goh     

The relation of apparent brightness to contrast threshold on a photopic background :Dependence on retinal position and target size

The luminance necessary for constant apparent brightness was measured as a function of retinal eccentricity at several photopic brightness levels and compared with the corresponding increment threshold functions. Thresholds rose substantially from the fovea to the periphery, but the contrast required for constant brightness showed little change as a function of eccentricity. A change of target size had relatively little effect on the shapes of the equal brightness curves. Two contributing factors to the difference between the threshold and equal brightness curves are systematic changes in

(1) the apparent brightness at threshold

(2) the exponent of the brightness power function. A neural mechanism is proposed which accounts for the results. A comparison with known retinal ganglion cell properties leads to the conclusion that this mechanism must be located proximally to the retina.