Benzodiazepine ([3H]flunitrazepam) binding in cat visual cortex: ontogenesis of normal characteristics and the effects of dark rearing

[3H]Flunitrazepam (FNZ) binding sites were characterized in homogenates of cat visual cortex during normal postnatal development and following dark rearing from birth. In parallel experiments, the distribution and density of [3H]FNZ binding sites were examined by in vitro autoradiographic or 'scrape' methods. In homogenates, Bmax measurements showed low early values, rising to a peak in receptor density at about 60 days postnatal, followed by a decline in adulthood. At all ages, gamma-aminobutyric acid (GABA) altered the Kd, but not the Bmax of [3H]FNZ binding sites. Kd values showed a general increase with age, parallelled by an increased sensitivity to GABA. Receptor autoradiography revealed that the highest density of [3H]FNZ binding sites was in layer IV of cats of all ages. Deafferentation of extrinsic inputs to the visual cortex by surgical undercutting did not alter this pattern of laminar distribution, indicating that the receptors were associated with intrinsic cortical elements rather than subcortical inputs. Dark rearing had no effect on [3H]FNZ laminar distribution in the visual cortex. The Bmax was higher at 30 days postnatal, but did not differ significantly thereafter. Modulation by GABA was concomitantly higher at 30 days, but lower than normal in dark-reared animals at ages greater than 30 days postnatal. The results are discussed in relation to the normal and abnormal development of GABA receptors in the cat visual cortex.     

Further study on the vascular basis for the reimplantation of the hand amputated through the palm

Summary Based on the anatomic data obtained from earlier studies on the vascular anatomy of the hand, the vascular architecture in the palm of the hand was studied on 60 sides of unembalmed adult upper extremities. Each palm was divided into 64 squares by 8 sagittal and 8 transverse sections. The vascular architecture in these squares and the arterial relations between them were observed and measured by angiography, operative microscopic dissection and computerised three-dimensional reconstruction. According to the pattern of the blood-vessels, the amputated palms can be classified into 4 types. The anatomic basis for the vascular anastomosis in each type is defined. There are three key-areas for the blood-supply of the palm and their significance is discussed. Apart from the 4 types of transversely amputated palms, the repair programe of the blood-vessles in 4 types of common obliquely amputated palms are also discussed.

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Etude complémentaire de l'anatomie vasculaire de la main pour la réimplantation des amputations transpalmaires

Résumé Sur la base de données anatomiques obtenues lors de précédents travaux sur l'anatomie vasculaire de la main, l'architecture vasculaire palmaire a été étudiée sur 60 extrémités supérieures de cadavres d'adultes, non embaumés. Chaque paume a été divisée en 64 carrés par 8 sections sagittales et 8 sections transversales. L'architecture vasculaire à l'intérieur des carrés et les relations artérielles entre eux ont été étudiées et mesurées par angiographie, dissection au microscope opérateur et reconstruction computérisée en 3D. Les paumes amputées ont été regroupées en 4 types d'après la distribution des vaisseaux sanguins. Les données anatomiques concernant les anastomoses vasculaires sont précisées. Il existe trois zones clés pour l'irrigation de la paume. Leur importance quant à l'irrigation de la main est exposée. Outre la division des paumes amputées transversalement en 4 types, le programme de réparation de vaisseaux dans les 4 types d'amputations obliques communes de la paume et aussi discuté.

     

白蛋白微球作为肝靶向给药载体的研究

用均匀设计方法和计算机技术筛选了乳化化学交联法制备白蛋白微球的六个因素,十二个水平。优化出最佳制备工艺,制备了平均粒径0.41～0.47μm的白蛋白微球。将此工艺制备的¹²⁵I-白蛋白微球做动物体内研究,结果表明微球iv后主要浓集在肝脏,可达注入总剂量的68%,此微球在靶组织肝脏的变化规律可用二室模型契合。     

Antimicrobial Activities of Skincare Preparations from Plant Extracts

In this study, Tithonia diversifolia Helms. (A Gray), Aloe secundiflora (Miller) and Azadirachta indica (A. Juss) plant extracts were used to make herbal soaps while Thevetia peruviana (Schum) seed oil was used to make a herbal lotion for skincare. The soaps were tested for the growth inhibition of Escherichia coli, and Candida albicans. The lotion was evaluated against Staphylococcus aureus and E.coli. Although Tithonia diversifolia soap exhibited the highest inhibitory effect on the test bacterial strains, it had the least inhibition against C. albicans. Results from this study indicated that the ‘Tithonia diversifolia’ soap would have superior skin protection against the tested bacteria but would offer the least skin protection against C. albicans. The herbal lotion inhibited S. aureus and E. coli in a concentration dependent manner, however, the inhibitory effect was more pronounced on S. aureus.     

Behavioral assessment of visual acuity in mice and rats

We have developed a simple computer-based discrimination task that enables the quick determination of visual acuities in rodents. A grating is displayed randomly on one of two monitors at the wide end of a trapezoidal-shaped tank containing shallow water. Animals are trained to swim toward the screens, and at a fixed distance, choose the screen displaying the grating and escape to a submerged platform hidden below it. Both mice and rats learn the task quickly. Performance falls below 70% when the spatial frequency is increased beyond 0.5 cycles in most C57BU6 mice, and around 1.0 cycles per degree (cpd) in Long-Evans rats.     

Experience-dependent plasticity of visual acuity in rats

Rats have become a popular model for investigating the mechanisms underlying ocular dominance plasticity; however, no quantitative assessment of the effects of visual deprivation on behavioural acuity has been reported in this species. We measured the spatial acuity of monocularly and binocularly deprived rats with a visual discrimination task. The average spatial acuity of normal rats and rats deprived of vision after postnatal day 40 was approximately 1 cycle/degree. Monocular deprivation up to postnatal day 40 resulted in a 30% decrease in acuity and there was no recovery after 8 months. Identical binocular deprivation produced a comparable but significantly smaller reduction in acuity. The deleterious effects of monocular and binocular deprivation on visual acuity indicate that the development of cortical receptive field properties related to spatial tuning are affected by both monocular and binocular deprivation. The similarities in the effects of visual deprivation on visual acuity between rats and other mammals confirm that rats are a good model system for studying the cellular and molecular mechanisms underlying experience-dependent visual plasticity.     

谷氨酸脱羧酶抑制剂L-苹果酸对小鼠学习记忆的影响

跳台法和Y迷宫法试验表明,小鼠po L-苹果酸600mg·kg^-1连续5d后对记忆的获得、巩固和再现均有明显的改善作用,并能促进空间辨别学习能力;L-苹果酸改善记忆的作用能被NMDA受体拮抗剂氯胺酮所拮抗。脑内游离氨基酸测定显示,L-苹果酸可明显降低小鼠脑内GABA水平,提高Glu/GABA比值。实验结果表明,脑内GABA水平下降,Glu/GABA比值升高对学习记忆有正性调节作用。