Altered GABAB receptor immunoreactivity in the gerbil hippocampus induced by baclofen and phaclofen, not seizure activity

The present study was performed to determine whether the effects induced by GABA(B) receptor-acting drugs would be related with the alteration in GABA(B) receptor expression in the hippocampus using Mongolian gerbil, a genetic epilepsy model. The distribution patterns of both GABA(B) receptor 1A/B and GABA(B)receptor 2 immunoreactivities were similarly detected in the hippocampi of normal and seizure-prone gerbils. Following baclofen (GABA(B) receptor agonist) or phaclofen (GABA(B) receptor antagonist) treatment, GABA(B) receptor immunoreactivities were decreased or increased by dose-dependent manners, respectively. Vigabatrin (GABA transaminase inhibitor) or 3-mercaptopropionic acid (GAD inhibitor) treatment did not affect GABA(B) receptor expressions. These findings suggest that GABA(B) receptor expression in the gerbil hippocampus may be altered by baclofen or phaclofen treatment.     

Protective effect of retinoic acid on interleukin-1 beta-induced cytotoxicity of pancreatic beta-cells

Cytokines produced by immune cells in pancreatic islets infiltrating are important mediators of beta-cell destruction in insulin-dependent diabetes mellitus. In this study, the effects of retinoic acid (RA) on cytokine-induced beta-cell dysfunction were examined. RA significantly protected interleukin-1 beta (IL-1) and interferon-gamma (IFN-gamma)-mediated cytotoxicity of rat insulinoma cell (RINm5F), and also reduced in IL-1 and IFN-gamma-induced nitric oxide (NO) production, which correlated well with reduced levels of the inducible form of NO synthase (iNOS) mRNA and protein. The molecular mechanism, by which RA inhibited iNOS gene expression, appeared to involve the inhibition of NF-kappa B activation. Our results suggest possible therapeutic value of RA for the prevention of diabetes mellitus progression.     

Microsatellite alterations in hepatocellular carcinoma and intrahepatic cholangiocarcinoma

A series of 20 hepatocellular carcinomas and 8 intrahepatic cholangiocarcinomas was screened from the Korean population for microsatellite alterations, including a loss of heterozygosity and replication errors using nine microsatellite markers containing several genes. The microsatellite results and our previous comparative genomic hybridization results of two tumors were compared at each locus, and the correlations between these and clinicopathologic variables were examined. The most characteristic findings were found at 13q. Replication errors were prevalent at D13S160 (13q21.2 approximately q31) and D13S292(13q12). The incidence of loss of heterozygosity, however, was higher at D13S153 (13q14.1 approximately q14.3) and D13S265(13q31 approximately q32). In contrast, there were higher deletion frequencies observed in hepatocellular carcinoma (HCC) and higher amplification frequencies observed in intrahepatic cholangiocarcinoma at 13q in our previous comparative genomic hybridization (CGH) study. Higher frequencies of replication errors were observed at D16S408 (13q12 approximately q21) and D16S504(13q23 approximately q24) in the HCC. This study found that significant differences in the patterns of genetic instability of microsatellites were dependent on the chromosomal loci. It is believed that certain genes at altered CGH regions, which are relevant to the development and/or progression of these cancers, are activated by different mutation mechanisms.     

LY294002 inhibits LPS-induced NO production through a inhibition of NF-kappaB activation: independent mechanism of phosphatidylinositol 3-kinase

Phosphatidylinositol 3-kinase (PI3K) is critical player in cell proliferation and survival. The effects of LY294002 and wortmannin, inhibitors of PI3K, on nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression in lipoploysaccharide (LPS)-induced Raw 264.7 cells were investigated. Significant inhibition of LPS-induced protein kinase B (PKB, Akt) phosphorylation occurred at 25 microM LY294002 or 0.5 microM wortmannin. At the same concentrations, LY294002, but not wortmannin, significantly inhibited NO production and iNOS expression. LY303511, an inactive analogue of LY294002, also inhibited NO production and iNOS expression. In addition, LY294002 and LY303511 significantly inhibited the DNA binding activity of NF-kappaB and NF-kappaB dependent reporter gene expression. These results suggest that LY294002 inhibits iNOS expression at least in part via inhibition of NF-kappaB activation, independent of PI3K.     

A case of leukemia cutis.

We report a case of leukemia cutis with atypical skin manifestations, presented with generalized various sized dark brownish to erythematous patches with plaques on the whole body of a 42-year-old man. Skin lesions developed 6 months ago and had no signs of itching or tenderness. He complained of sustaining fevers with abdominal discomfort. Laboratory findings showed elevation of leukocyte count and peripheral blood smear revealed 86% of lymphocyte. Histologic examination showed diffuse infiltration of abnormal cells that appeared to be leukemic in nature.     

应用微囊化转基因细胞进行小鼠腹腔移植的实验研究

目的:探讨微囊化转基因细胞用于异体细胞移植治疗的可能性。方法:使用静电液滴技术制备海藻酸钠-壳聚糖微胶囊,包埋转入癌胚抗原部分基因的人成纤维样骨髓基质细胞,进行实验小鼠腹腔移植。结果:微囊化人源细胞移植到小鼠腹腔3个月内,细胞可以继续生长、增殖并提高小鼠的兔疫功能。结论:海藻酸钠-壳聚糖作为成囊材料具有良好的生物相容性、囊膜强度和免疫隔离作用;微囊化细胞移植有助于扩大异体移植的细胞来源,并为构建微囊化转基因细胞疫苗治疗恶性肿瘤的研究提供了可靠的依据。     

Expression of rck/p54, a DEAD-box RNA helicase, in gametogenesis and early embryogenesis of mice.

rck/p54 is a DEAD-box RNA helicase protein with ATP-dependent RNA-unwinding activity. Its ortholog is required for sexual reproduction in yeast and for oocyte survival and sperm fertility in Caenorhabditis elegans. In the current study, we investigated the expression of rck/p54 in mouse gametogenesis and early embryogenesis. Western blot analysis revealed that rck/p54 was highly expressed in both the ovary and testis. In the ovary, maturing oocytes strongly expressed rck/p54 in their cytoplasm. In contrast, in the testis, spermatogonia and primary spermatocytes highly expressed rck/p54 in their cytoplasm, but its expression decreased in the spermatids. Interestingly, rck/p54 was concentrated in the heads of spermatozoa; and then its expression gradually decreased as these cells matured along the epididymal duct. After fertilization, rck/p54 protein and its mRNA remained present in the pronucleus phase; and then their expression levels slightly but definitely decreased in morulae and blastocytes. The injection of a CMV-based rck/p54 expression vector into the pronuclei of fertilized eggs caused a delay in early embryogenesis. In generating RCK transgenic mice, the birth rate of the mice was significantly lower than those of other gene transgenic mice. These findings indicate that rck/p54 may play an important role in gametogenesis and early embryogenesis in mammals.     

Administration of agonistic anti-4-1BB monoclonal antibody leads to the amelioration of inflammatory bowel disease

4-1BB (CDw 137), a member of the tumor necrosis factor receptor (TNFR) superfamily, is a costimulatory receptor primarily expressed on activated T cells. It has been shown that the administration of agonistic anti-4-1BB monoclonal antibody (mAb) enhances tumor immunity and allogenic immune responses. Paradoxically, we found that the administration of anti-4-1BB mAb reduced the incidence and severity of inflammatory bowel disease. In this study, we investigated the effects of anti-4-1BB mAb in a murine intestinal inflammation model, which induced by the hapten reagent, 2,4,6-trinitrobenzene sulfonic acid (TNBS) and mimics immunologic characteristics of human Crohn's disease (CD). Colitis was induced by rectal administration of 2mg of TNBS in 35% ethanol using a vinyl catheter positioned 4cm from the anus. All mice were sacrificed 3 and 10 days after the TNBS administration. The disease activity index (DAI), histological changes of the colon and production of cytokines (IL-2, IL-4, IL-10 and IFN-gamma) were evaluated. The surface molecules of T cells in peripheral blood, spleen and mesenteric lymph nodes were analyzed by flow cytometry. When mice were treated with anti-4-1BB mAb, improvement in both wasting and histopathologic signs of colonic inflammation was observed. The increase a number of splenic CD4(+)CD25(+) T cells and decreased synthesis of the Th1 cytokine IL-2 also occurred. Interestingly, increased production of Th1 cytokine IFN-gamma and proportion of CD8(+) T cells were observed in mice treated with anti-4-1BB mAb in comparison to the colitic mice. These studies show, for the first time, that agonistic anti-4-1BB mAb can improve experimental colitis by reduction of IL-2 and augmentation of CD4(+)CD25(+) regulatory T cells. TNBS colitis is Th1-mediated and has similar histologic features and distribution of inflammation to CD. This study suggests that anti-4-1BB mAb therapy could be effective in the treatment of patients with CD.     

Recognition of Pneumocystis carinii antigen on its surface by immunohistochemistry and immunoelectron microscopy.

The aim of this study was to detect the surface antigens in different stages of experimental induced Pneumocystis carinii in Sprague-Dawley rats. Immunohistochemical staining with monoclonal (900, 902 and 904) and polyclonal (SP-D) antibodies demonstrated that the P. carinii organisms were mostly in the alveolar lumina. The binding sites of the monoclonal (900, 902 and 904) and polyclonal (SP-D) antibodies developed against P. carinii were examined at the ultrastructural level by using a post-embedding immunogold labeling. The gold particles were observed evenly on the surface of precyst and cyst stages of the P. carinii. In the trophozoite stage, scattered gold particles were seen on the pellicles and tubular expansions. The monoclonal antibodies reacted mainly with pellicles of P. carinii, whereas SP-D labeled pellicles, intracystic bodies, cytoplasms of alveolar macrophages, free floating surfactant material in the alveolar spaces, and adjacent type II epithelial cells. In the immunogold labeling, basically no significant differences were found in the precyst, cyst, and ruptured cyst stages. These results indicate that the gold particles were observed adhering to every stage of P. carinii, mostly concentrated on the pellicles, and more concentrated in the precyst or cyst stage than trophozoite stage which may be due to an increase in antigen accumulation during development from the trophozoite to the cyst.