Effects of potassium chloride on sexual behavior and the cortical EEG in the ovariectomized rat

The facilitation of lordosis behavior by the cortical application of KCl has been confirmed. Ovariectomized female rats were injected with estradiol benzoate (EB) for 3 days and then a 15% KCl solution was put into permanent cannulae resting on the cortical dura. Sexual behavior tests were performed 15, 30, 60 and 90 min and 24 hr after KCl application and a lordosis quotient (LQ) was obtained from each 10-mount test. There was a significant increase in the LQ 15 min after KCl application to levels which approached those seen after priming with both EB and progesterone. Although lordosis behavior was facilitated, no EEG changes were found following KCl application in 7 of 9 rats, but there was marked depression of the amplitude of the cortical EEG in the remaining 2. It is concluded that KCl application, a treatment which produces functional decortication by inducing spreading depression, suppresses a cortical inhibitory system for lordosis behavior.     

Technical improvements in the clotted plasma droplet MIF assay in vitro.

The migration inhibitory activity of culture supernatants of rat and human lymphocytes stimulated with PHA and Con A-Sepharose was tested on cell migration from clotted plasma droplets. This technique was improved by using homologous as well as heterologous plasma and fibrinogen solutions for suspending the migratory cells, automatic micropipettes for performing the technique and purified cell populations as target. The effects of calcium chloride and of the cell concentration in the plasma droplets on the migration indices obtained in the MIF assay were tested.     

糖尿病大鼠视网膜基因表达谱差异的初步分析

目的 建立大鼠正常视网膜和糖尿病8周视网膜基因表达谱，比较两者差异，初步分析糖尿病视网膜病变的相关基因。方法 通过限制片段差异显示 PCR（ restriction fragments differential display-PCR，RFDD-PCR）获得正常大鼠视网膜及8周糖尿病大鼠视网膜组织转录组片段。应用Fraent Analysis等软件，对差异片段进行生物信息学分析，初步确定糖尿病视网膜病变相关基因／表达序列标签（ expression sequence tag, Ksr）。结果 获得有意义的片段共3639个，有差异的片段840个，占表达数的23．08％。其中包括5个视觉传导相关基因，13个兴奋性神经递质受体基因和3个抑制性神经递质受体基因。糖尿病8周大鼠视网膜Rhodopsin kinase,β-arrestin,Phosducin, rod photoreceptor cGMP-gated channel 和 Rpe65的表达下调，离子型谷氨酸受体iGluR1-4下调，代谢性谷氨酸受体及γ-氨基丁酸受体各亚型则普遍上调，而甘氨酸受体表达无变化。结论 糖尿病8周大鼠神经视网膜已受到累及，其基因表达模式的改变，可能与糖尿病早期视功能损害有关。     

HLA-C revisited

During the past 10 years knowledge about the interactions between major histocompatibility complex (MHC) class I molecules and the T-cell receptor (TCR) complex of cytotoxic T-cells (CTL) has developed dramatically. But the primary interest, both with respect to structure as well as function, has concentrated on HLA-A and -B molecules because of their high sequence polymorphism and their dominating presence at the cell surface. In contrast, HLA-C molecules seemed to be of only minor importance in the cascade of immune reactions owing to their more limited polymorphism and reduced levels of surface expression. The inability to define a number of antigen specificities had the result that HLA-C molecules were often neglected in studies of immune response, transplantation, and disease association. More recently a new function has been identified for HLA class I molecules where they act as inhibitors of the lytic capacity of natural killer (NK) cells and non-MHC-restricted T-cells. Moreover, the understanding of this novel mode of negative regulation of cytotoxicity was remarkably influenced by HLA-C since these were the first HLA class I molecules found to have such inhibitory potential. With this new inhibitory function serving as an essential component of the immune system, HLA-C molecules can no longer be neglected.     

Type 1 and type 2 tumor infiltrating effector cell subpopulations in progressive breast cancer

Effector T cells fall into two subpopulations based on cytokine-secretion. Type 1 cells secrete IFN-gamma, whereas type 2 cells secrete IL-4, IL-10, and GM-CSF. NKT cells represent a third subpopulation that secretes similar cytokines and have been associated with immunoregulation. Using the TS/A adenocarcinoma, we assessed the phenotype and kinetics of tumor-infiltrating lymphocytes (TIL) in mice challenged subcutaneously in the mammary region. Flow cytometric analysis shows that T cells do not infiltrate the primary tumor site until days 7-14 following tumor challenge. Both CD4 and CD8 TILs were predominantly CD44(High) and expressed CD25, CD69, and CD95 cell surface activation markers. Activated CD4/CD44(High) TIL numbers reached peak levels at day 21 that precipitously decreased by day 28 whereas corresponding CD8 cell numbers progressively increased, however, at lower levels and with later kinetics. Intracellular cytokine staining showed that greater numbers of IL-4-producing Th2 cells were elicited and with earlier kinetics than that of IFN-gamma-producing Th1 cells. T cells co-expressing DX5 (CD3(+)/DX5(+)) emerged (>21 days), suggesting a recruitment of NK-like T cells at later stages of tumor progression. Moreover, tumors selectively up-regulated TGF-beta, MIF, and IP-10 gene expression at times as early as day 4, with peak levels at day 7 in vivo. Such gene expression remained elevated and correlated with a continued progression in tumor growth suggesting that preferential effector cell recruitment and production of select factors during different stages of tumor maturation may aid in regulating effective endogenous antitumor responses in progressive breast cancer.     

Chemical Characterization of Macrophage Cytotoxicity Factor,Macrophage Migration Inhibitory Factor,T-Helper Cell-Replacing Factor and Colony-Stimulating Factor from Culture Supernatants of Concanavalin A-Stimulated Murine Spleen Cells

Supernatants from Concanavalin A-stimulated murine spleen cells were subjected to hydrophobic interaction chromatography on phenyl-Sepharose. Macrophage cytotoxicity factor (MCF), macrophage migration inhibitory factor (MIF), T-helper cell-replacing factor (TRF) and colony-stimulating factor (CSF) were bound at high ionic strength and were released stepwise at low ionic strength. CSF thus could be separated from MCF, MIF and TRF and the bulk of other proteins. Chromatography of pools containing MCF, MIF and TRF on Sephadex did not lead to a separation of the three activities which were all found in a molecular weight range of 25.000-55.000. Isoelectric focusing of these pools in pH range from 4 to 9 gave two peaks for MCF at pH 8.2 and 7.2, whereas MIF activity focused from pH 4.5 to 5.5. TRF activity was found in a single sharp peak at pH 5.3. The results demonstrate that the four biological activities can be distinguished on a chemical basis and are accessible for purification and chemical characterization.     

T淋巴细胞表达杀伤细胞抑制性受体的研究进展

Only in recent years,attentions have been drawn to the significance of expressing killer cell inhibitory receptors(KIR)in T cells.KIRs specifically bind to the corresponding region of the MHC class I molecules and transmit negative signals to prevent cytotoxity of T cells.When the ligands of KIRs are missing,the lysis of the target cells can‘t be avoided.Perhaps the existence of KIRs is the main mechanism for preventing T cells from attacking autologous tissues.The recognition mechanism of the interaction between the KIR^ donor T cells and the recipient‘s MHC class I molecule expressing tissue cells might shed light on the establishment of the immunotolerance for the prevention of allo-graft rejection and graft-versus-host disease.     

Participation of Ia reciprocal inhibitory neurons in the spinal circuitry of the tonic neck reflex

Summary As part of our studies of the spinal circuitry of the tonic neck reflex, we have recorded extracellularly from Ia reciprocal inhibitory neurons of the decerebrate, labyrinthectomized cat. The activity of a majority of neurons driven by stimulation of the quadriceps nerve was modulated by sinusoidal rotation of the neck; such modulation was much less frequent in the case of neurons driven by stimulation of nerves to more distal muscles. The results suggest that some of the inhibition which is part of the tonic neck reflex is mediated by Ia reciprocal inhibitory neurons, but that other pathways must also play an important role.     

Apamin distinguishes two types of relaxation mediated by enteric nerves in the guinea-pig gastrointestinal tract

Summary Eight smooth muscle preparations from the stomach, small intestine and large intestine of the guinea-pig were used to compare apamin's actions in reducing the effectiveness of transmission from enteric inhibitory nerves and in reducing responses to inhibitory agonists ,-methylene ATP, VIP and isoprenaline. The effects of apamin on inhibitory reflexes in the ileum and colon were also evaluated. Apamin had little or no effect on responses to VIP and isoprenaline in any region, but consistently and substantially reduced responses to ,-methylene ATP. Responses to stimulation of enteric inhibitory neurons were substantially reduced by apamin in the antrum circular muscle, ileum longitudinal and circular muscle, taenia coli and distal colon longitudinal muscle, but it was ineffective in the fundus circular muscle, proximal colon longitudinal muscle and distal colon circular muscle. It caused a small reduction of the relaxation of the ileal circular muscle caused reflexly by distension, but did not modify the similar descending inhibitory reflex in the circular muscle of the colon. It is concluded that apamin can be used to distinguish two types of non-noradrenergic transmission from enteric inhibitory nerves to gastrointestinal muscle. Furthermore, neither VIP nor ATP can be the sole transmitter chemical released from enteric inhibitory neurons throughout the gastrointestinal tract.     

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.