Rewarding properties of social interactions in adolescent and adult male and female rats: impact of social versus isolate housing of subjects and partners

Social interactions have been shown to be rewarding for adolescent and adult rats; however, there has been little emphasis on comparing the strength of the rewarding value of social stimuli across ontogeny. Since age differences in social interactions may vary with sex or housing circumstances, the present study assessed social conditioned place preference (CPP) in adolescent and adult male and female Sprague-Dawley rats housed either socially or in isolation and conditioned with either group-housed or isolate-housed partners. Isolated animals of both sexes and ages demonstrated social CPP, with the strongest preference emerging in adolescent males. Social CPP was not evident in group-housed adults whereas group-housed adolescents developed a preference for the compartment previously paired with similarly housed partners; however, when socially housed adolescents were conditioned with isolated partners, social CPP did not emerge. Age differences in social CPP may reflect age-related neural alterations in brain systems implicated in regulation of social behavior.     

Isolation and partial characterization of the tegumental outer membrane of schistosomula of Schistosoma mansoni

Separation of the external membranes from freshly converted mechanical schistosomula of Schistosoma mansoni was achieved by osmotic shock under hypertonic conditions, followed by mechanical shearing and ultracentrifugation. Prior to treatment, the schistosomula were surface labeled by introduction of N-DNP-epsilon-aminocaproylphosphatidylethanolamine molecules into their lipid bilayer followed by anti-DNP antibodies and stained with either 125I-protein-A or ferritin labeled secondary anti-DNP antibodies. This label provided a membrane marker by which the purity of the preparation could be assessed at each stage. Fluorescence staining with FITC-conjugated secondary antibodies prior to treatment revealed that the homogeneously stained membrane of the intact schistosomula became swollen and ruptured after the osmotic shock. The isolated membrane pellet was intensely fluorescent. Electron microscopical examination revealed mostly vesicles, some of them with organized multilayer assembly. The vesicles were ferritin labeled, indicating that they originated from the outer surface membrane of the schistosomula. A 100 fold enrichment in the alkaline phosphatase activity and about 300 fold enrichment in acetylcholinesterase activity in the membrane preparations, as compared to the intact schistosomula, was found. The isolated tegument was analyzed by SDS-polyacrylamide gel electrophoresis. The pattern obtained showed three major bands, of molecular weights 69 000, 45 000 and 12 000 alongside with a large number of minor bands. Immunoprecipitation of the isolated 125I-labeled membrane antigens with antisera from chronically infected mice revealed these three major bands together with three other bands of molecular weight 38 000, 23 000 and 16 000.     

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.     

Characterization of the prostanoid receptors and of the contractile effects of prostaglandin F2a in human pial arteries

The contractile and relaxant effects of various prostanoids were studied on isolated human pial arteries. Contractions were elicited with the following order of potency: U46619?U44069>PGB₂>PGF_2a>PGE₂?PGD₂>PGF_1a≥TXB₂, indicating that prostanoid-induced contractions probably are mediated by a thromboxane-sensitive receptor. Relaxation of PGF_2a-contracted arteries was induced with the order of potency: PGE₂> PGE₁>PGD₂?PGD₁. Vessels contrated by K⁺ were relaxed only by PGE,. Since PGI₂ was previously found to be more potent than all the prostanoids tested in the present study, relaxant responses are probably mediated via a PGI₂-sensitive receptor. The roles of free extracellular and cellularly bound calcium for the contractile effects of PGF_2a and K⁺ were estimated by incubating the arteries for various times in calcium-free medium containing 10^-5 M EGTA. Incubation for 5–10 min abolished K⁺-induced contractions, whereas after 40 min of incubation PGF_2a still induced contractions that reached 70% of control. The PGF_2a-induced contraction was biphasic in 8 out of 10 preparations. The second phase could be eliminated by increasing the EGTA-concentration to 10^-4 M, as well as by nifedipine pretreatment. In calcium-free, high K⁺ medium calcium-induced contractions were elicited at lower concentrations in the presence of PGF_2a. The results suggest that PGF_2a-induced contractions in human pial arteries are relatively independent of free extracellular calcium. PGF_2a may promote trans-membrane influx of calcium, as well as release calcium from seemingly superficially located cellular stores.     

Association between HLA and Japanese patients with rheumatoid arthritis

Japanese patients with rheumatoid arthritis (RA) were observed to have a statistical association with HLA-DR4, MT3. Strong association between the clinical severity of RA and HLA was also observed. Male patients had a stronger association with HLA than female patients. Males are more resistant to RA than females. This suggested that the threshold of liability for RA is higher in males than in females. Japanese patients with RA with systemic vasculitis were negative for HLA-Bw44 and had antilymphocytotoxic autoantibody, indicating that RA with systemic vasculitis is different in etiology from RA without systemic vasculitis.     

非水介质中明胶水凝胶电场驱动行为的研究

研究了明胶水凝胶在绝缘硅油中的电场响应行为。结果表明,在硅油中,明胶水凝胶在外加高压直流电场作用下可发生运动,其运动由转动和平动两部分组成。存在一个运动所需的最小阈值电场,只有外加电场在此阈值以上时,才可观察到水凝胶明显的运动。水凝胶的运动速度随外加电场的增大而增大,其运动可通过外加电场的大小来调控。由硅油很稳定且在电场中会电解,因此避免了传统电场驱动水凝胶在水介质中响应时不可避免的电解缺点,为建立一种新的电响应凝毅然驱动方式提供了可能。     

幽门螺杆菌分离培养技术的改进

探讨自制的改良布氏活性炭巧克力培养基,置厌氧罐蜡烛培养环境分离临床粘膜标本幽门螺杆菌(Hp)的检出率.结果表明66例粘膜标本中分离出Hp54株(81.8%),44株Hp滤液有24株(54.5%)具有细胞毒活性,其中26例消化性溃疡患者有18例(69.2%),18例慢性胃炎患者有6例(33.3%)为Hp(Toxin+)感染.结果提示通过对Hp生物学性状和毒素的检测结果证实,该法可用于临床粘膜标本Hp的常规分离培养.     

Secretions released from mesenchymal stem cells improve spermatogenesis restoration of cytotoxic treatment with busulfan in azoospermia mice

This study aimed at the efficacy of sequential treatment of bone marrow-derived mesenchymal stem cell secretion for busulfan-treated azoospermia in mice. The conditioned media (CM) was obtained from bone marrow mesenchymal stem cells (MSCs) or 293 cells. Chemically induced azoospermia mice received 200 μl MSC-CM or 293-CM twice a week intravenously for three consecutive weeks. The histological assessment of spermatogenic recovery quantifying the expression of meiosis-associated genes, and Sertoli cell barrier functional factors were assessed. The characteristics of TM4 cells (Sertoli cell line) after pre-incubation of MSC-CM in vitro were also obtained. The MSC-CM group had the most spermatogenic colonies among the three groups (p < .05), but no spermatids were seen. Expressions of the meiosis-associated genes Dazl, Vasa, Miwi, Stra8, CyclinA1, Pgk2 and Scp3 in MSC-CM testis were remarkably higher compared with 293-CM and busulfan groups respectively (p < .05). The levels of Sertoli cell barrier functional factors, for example ICAM-1 and N-cadherin, were significantly increased during MSC-CM treatment (p < .05). Moreover, pre-incubation of MSC-CM particularly accelerated the CD54 (ICAM-1) and CD44 expressions of TM4 cells and promoted cell inherent adhesion. MSC-CM treatment can significantly improve the short-term restoration of spermatogonial structures of chemically induced azoospermia related to facilitating Sertoli cell adhesion integrity.     

Human myeloma light chains with increased molecular weight: high frequency among lambda chains

The discovery of a human myeloma protein comprising a kappa L-chain with an increased mol. wt of 30,000) (Bouvet et. al., 1980) prompted investigations on the incidence of such heavier L-chains among other human myeloma proteins. In 105 samples examined, 34 were found to have L-chains heavier than normal (23,000-24,000), ranging from 25,000 up to 31,000, and five of lighter mol. wt (21,000-22,000). These mol. wt abnormalities were detected by electrophoresis in sodium dodecyl sulfate 10% polyacrylamide gels (SDS-PAGE) after reduction with 2-mercaptoethanol. The mol. wt of three of the heavier kappa or lambda chains was also estimated by filtration through a Sephadex G100 column and by sedimentation equilibrium. All three methods indicated a mol. wt increase of about 15-25% as compared with the usual mol. wt. The distribution of the high mol. wt chains among all L-chains examined was found to be 11 out of 62 kappa chains (17.7%) and 23 out of 43 lambda chains (53%) (P less than 0.001). A preferential association of such L-chains with H-chains producing multiple bands in SDS-PAGE (P less than 0.01) and an association between multiple L-chain and multiple H-chain band (P less than 0.05) were also observed. In contrast, no abnormal L-chain was found in immunoglobulins from normal subjects. Spontaneous degradation of the normal H-chains sometimes yielded fragments of 30,000 mol. wt. These fragments were easily distinguishable from abnormal L-chains. The nature of extra mol. wt in heavy L-chains was investigated for the presence of carbohydrate moiety. Four large and three normal size L-chains were examined for amino-sugar and sialic acid content. A small amount (one residue per molecule) of amino-sugar was detected only in two normal and two heavy L-chains, whereas sialic acid was only found in the heaviest (27,000-30,000) L-chains (Lh) and in small percentage (one or two residues per molecule). Total sugar estimation in one Lh chain indicated a proportion not exceeding three or four residues per L-chain (mol. wt 1,000) and this is insufficient to explain the 15-25% (3,600-6,000) mol. wt increase. It is therefore possible that, at least in some heavy myeloma L-chains, an additional peptide is expressed. Whatever the nature of the increase it would be of interest to elucidate whether this is a marker of malignant process or of an intermediate step of normal Ig synthesis.     

Interferon gamma and interleukin 10 levels in preimplantation embryo culture media

Purpose The aim of our study is to elucidate whether human oocyteslembryos secrete IFN and/or IL-10 and whether the fertilization process depends on the balance between these cytokines.Methods A total of 142 embryo culture media from 24 patients were collected and the cytokine levels were tested with ELISA.Results IFN and IL-10 were detectable in 40.1% and 29.6% of culture media respectively. The difference of IFN and IL-10 levels in media from fertilized oocytes between day 1 and day 2 are significant (0.46 vs. 1.47 and 34.2 vs. 12.7, respectively). However there was no significant difference between the IFN levels of the media from fertilized and nonfertilized oocytes 0.46 vs. 0.85 at day 1 and 1.47 vs. 1.49 at day 2, as well as IL-10 levels 34.2 vs. 30.9 at day 1 and 12.7 vs. 9.58 at day 2 respectively.Conclusions Human preimplantation embryos secrete the cytokines IFN and IL-10. No effect of these cytokines on fertilization process could be shown.Presented at the IXth World Congress on In Vitro Fertilization and Alternate Assisted Reproduction, April 3–7, 1995, Vienna, Austria.