Expression of the c-erbB-2-encoded oncoprotein and progesterone receptor in human meningiomas

The present study investigated the expression of c-erbB-2 in 59 meningiomas, including different histological subtypes and anaplastic variants, by immunocytochemistry and molecular biological techniques. Immunohistochemistry using the monoclonal antibody FWP-51 directed against c-erbB-2-encoded oncoprotein gp185 demonstrated variable degrees of immunoreactivity in all meningiomas. The intensity of immunostaining correlated with the degree of expression as assessed by Western analysis in 28 meningiomas using polyclonal antiserum 21N. There was no correlation between the degree of expression and histological variants. Immunoreactivity of all menigiomas was distinctly less intense, however, than that of the human breast cancer cell line SK-BR-3, and slightly lower than that of brain metastases of breast and ovarian carcinomas that served as positive controls for both methods. By Southern analysis all meningiomas showed a single copy of the c-erbB-2 gene. Non-neoplastic arachnoid cap cells also exhibited c-erbB-2 expression and the degree of immunoreactivity was comparable with the majority of meningiomas. These data argue against an overexpression of c-erbB-2 in meningiomas, but rather indicate a cell-type-specific constitutive expression of the c-erbB-2 gene product in meningiomas and their putative progenitor cells. Since a subgroup of meningiomas is known to express progesterone receptors (PR), gp185 immunoreactivity was compared to the hormone receptor status using monoclonal antibody KD68. Fifty-six percent meningiomas showed PR immunoreactivity, but there was no statistically significant correlation with the degree of gp185 expression.This study was supported by a grant of the Tumorzentrum Heidelberg/Mannheim (M.K., No. 10028060)     

静脉预注H1,H2受体阻滞药对减轻鱼精蛋白副作用的研究

将３０例ＡＳＤ、ＶＳＤ患者随机分为对照与预防用药两组，对比观察Ｈ１、Ｈ２受体阻滞药苯海拉明、西米替丁对减轻鱼精蛋白副作用的效果和应用鱼精蛋白后补体Ｃ３、Ｃ４、ＣＨ５０浓度变化。结果发现预防用药组血液动力学变化明显小于对照组，两组之间差异显著（Ｐ＜０．０１）。应用鱼精蛋白后Ｃ３、Ｃ４、ＣＨ５０均下降，与用药前相比差异显著（Ｐ＜０．０１）。提示鱼精蛋白中和肝素可引起补体激活、组胺释放，Ｈ１、Ｈ２受体阻滞药能够减轻鱼精蛋白引起的血压下降。     

The 2,4-dinitrophenyl group for protection of hydroxyl function of tyrosine during solid-phase peptide synthesis

The facile thiolytic cleavage of the O-2,4-dinitrophenyl (Dnp) tyrosine bond was applied to the solid-phase synthesis of the 22-amino acid residue peptide H-Asp-Ala-Val-Tyr -Thr-Gly-Leu-Asn-Thr-Arg-Asn-Gln-Glu-Thr-Tyr -Glu-Thr-Leu-Lys-His-Glu-Lys-OH, corresponding to positions 62-83 in the chain of the type 1 receptor for Fc_ε, domains expressed on the rat mucosal-type mast cells (line RBL-2H3). A method for the spectrophotometric determination of insoluble O-Dnp as well as of unprotected phenolic moieties of tyrosine was developed. It is based on monitoring S-Dnp-2-mercaptoethanol, produced upon O-Dnp thiolysis by 2-mercaptoethanol. © Munksgaard 1995. Dedicated to the memory of Dr. Susumu Funakoshi, a dear friend and a leader in peptide chemistry.     

Nerve growth factor and p75NGFR factor receptor mRNA change in rodent CNS following stress activation of the hypothalamo-pituitary-adrenocortical axis

The synthesis of nerve growth factor (NGF) by the hippocampus raises the possibility that NGF may play a role in the regulation of the hypothalamic-pituitary-adrenal axis (HPAA). Subchronic cold stress has been shown to activate the HPAA in a mild noninvasive manner, to stimulate serum glucocorticoid levels, and to perturb NGF binding in hippocampus and basal forebrain. One or repeated episodes of cold stress increased NGF mRNA levels in the hippocampus and p75^NGFR mRNA levels in the basal forebrain. These changes were not due to elevated serum glucocorticoid levels since treatment with exogenous corticosterone had no effect on NGF and p75^NGFR mRNA levels. Adrenalectomy did not prevent the stress induced increases in NGF and p75^NGFR mRNA. © 1993 Wiley-Liss, Inc.     

Raf-1 kinase,epidermal growth factor receptors,and mutant ras proteins in colonic carcinomas

Epidermal growth factor receptors (EGFR) andras mutations are known to play a significant role in controlling cell growth and tumor promotion. Both of them transmit mitogenic signals to the nucleus by activation of Raf-1 kinase. In this study, the expression of EGFR and mutant Ras proteins, and, for the first time, the expression, phosphorylation and kinase activity of Raf-1 kinase have been determined in paired samples of colorectal cancer and mucosa. The tumor and mucosa samples did not differ significantly with regard to Raf-1 kinase content and activity. A major difference between tumors and mucosa was found, however, in the phosphorylation of Raf-1. Most of the mucosa samples (13/20), but only 1/20 of the cancer samples, contained hyperphosphorylated Raf-1. EGFR were significantly (p=0.0025) decreased in the tumors. The decreased phosphorylation of Raf-1 in colonic carcinomas could be the result of activation of Raf-1 phosphatases or inactivation of kinases phosphorylating Raf-1. New forms of treatment based on EGFR overexpression do not seem to be suitable for the majority of colonic cancers.This work was supported by the state of Baden-Württemberg (Verbundforschungsprojekt: Aufklärung von Mechanismen der Tumorentstehung und Tumorabwehr).     

Polysialylated Neural Cell Adhesion is Involved in Target-induced Morphological Differentiation of Arcuate Dopaminergic Neurons

We have previously shown that the morphological and biochemical maturation of developing rat hypothalamic dopaminergic neurons is accelerated when they are cocultivated with pituitary intermediate lobe cells, one of their targets. Only two subsets of hypothalamic dopaminergic neurons (arcuate, A12, and periventricular, A14, nuclei) may project to the pars intermedia. In order to determine whether the two populations are equally responsive to coculture conditions, we microdissected the hypothalamus of 17-day-old rat fetuses in two fragments containing cell bodies from the A12 and from the A14 regions, prepared neuronal cultures from both portions and incubated them separately with intermediate lobe cells. The presence of intermediate lobe cells increased tyrosine hydroxylase levels in both dopaminergic neuron subsets, but morphological differentiation was accelerated in dopaminergic neurons originating in the arcuate nucleus only. We then investigated whether physical contact between developing arcuate neurons and their target cells was a prerequisite of the morphological effect by interposing a semipermeable membrane between cultivated neurons and intermediate lobe cells in transwell culture dishes. The morphological effect was no longer observed under transwell coculture conditions, pointing to the involvement of membrane-bound molecules. Accordingly, the stimulating effect of coculture on arcuate dopaminergic neurons was completely abolished by the removal of polysialic acid on neural cell adhesion molecules by endoneuraminidase N treatment. Thus, maturation of A12 and A14 dopaminergic neurons exhibits differential susceptibility to intermediate lobe target cells, and polysialylated-NCAM is required for the contact-dependent effect.     

重症肌无力中枢神经系统受损模型

目的近年研究结果表明，重症肌无力（ＭＧ）病变部位并不仅仅局限于神经肌接头（ＮＭＪ）处突触后膜烟碱型乙酰胆碱受体（ｎＡＣｈＲ），烟碱型乙酰胆碱受体抗体（ＡＣｈＲ－ａｂ）病理作用可能波及到中枢神经系统（ＣＮＳ）。因此，有必要建立模拟ＭＧ患者ＣＮＳ损害的动物模型，研究ＭＧ患者脑脊液中存在的ＡＣｈＲ－ａｂ引起ＣＮＳ损害的机制。方法从ＭＧ患者血中提取的ＡＣｈＲ－ａｂ经侧脑室穿刺注入到大鼠脑室系统，然后观察其症状和体征，以及用脑干听觉诱发电位仪（ＢＡＥＰ）检测鼠脑干听觉传导中枢功能。用免疫组化法（ＡＢＣ）研究ＡＣｈＲ－ａｂ与ＣＮＳ神经－ｎＡＣｈＲ之间免疫结合反应及其分布。结果大鼠除了出现脑干听觉传导中枢功能障碍外，还出现类似于ＭＧ动物模型表现的症状。免疫组化研究结果显示，神经－ｎＡＣｈＲ样阳性免疫反应广泛分布于ＣＮＳ许多部位。结论脑室内注入的ＡＣｈＲ－ａｂ与神经－ＡＣｈＲ结合引起ＣＮＳ功能障碍和出现ＭＧ动物模型样症状。我们首次建立的中枢受损的ＭＧ模型将有助于阐明ＡＣｈＲ－ａｂ引起中枢受损和ＣＮＳ下位运动神经元引起横纹肌收缩无力的机制。     

胆囊癌组织中NDPK／nm23的表达及意义

作者用免疫组化ＡＢＣ法对４１例胆囊癌标本核苷二磷酸激酶（ＮＤＰＫ，下同）／ｎｍ２３表达进行了测定，结果发现：ｎｍ２３在恶性肿瘤中的表达率明显高于良性病变（Ｐ＜０．０５）。ＮＤＰＫ／ｎｍ２３表达与胆囊癌组织的分化、局部浸润及淋巴转移密切相关（Ｐ＜０．０１）。ＮＤＰＫ／ｎｍ２３阳性患者生存中位数１２．２５个月，阴性患者６．５个月，两者存在显著差异（Ｐ＜０．０１），提示ｎｍ２３检测对预后有重要价值。     

Inadequate Erythropoietin Response to Anaemia in HIV Patients: Relationship to Serum Levels of Tumour Necrosis Factor-Alpha, Interleukin-6 and Their Soluble receptors

Severe anaemia is a frequent complication in advanced HIV infection. In our study we investigated the interaction between cytokine network, HIV infection and erythropoietin (Epo) response with increasing anaemia levels. No correlations could be established between circulating tumour necrosis factor (TNF)-alpha and any of the examined parameters. However, a negative correlation was found between haemoglobin values and soluble TNF receptor levels (sTNF-R-I: r  = −0.54; P  < 0.001; sTNF-R II: r  = −0.47; P  < 0.001) as well as interleukin-6 levels ( r  = −0.29; P  < 0.001). In contrast, no significant increase in log[Epo], counterbalancing haemoglobin decline and paralleling the rise in sTNF receptors, was found. In patients classified as stage III, according to the Centers for Disease Control (CDC) classification, the erythropoietin response was significantly more impaired than in patients from CDC groups I and II ( P  < 0.001). The results of this study suggest that similar to its action in vitro , activation of the TNF/TNF-R system may impair erythropoietin production in HIV-associated anaemia. Due to the brief half-life of TNF-α, this activation is particularly reflected by elevations of soluble TNF receptor levels.     

A chimeric tyrosine/tryptophan hydroxylase

The neurotransmitter biosynthetic enzymes, tyrosine hydroxylase (TH), and tryptophan hydroxylase (TPH) are each composed of an amino-terminal regulatory domain and a carboxylterminal catalytic domain. A chimeric hydroxylase was generated by coupling the regulatory domain of TH (TH-R) to the catalytic domain of TPH (TPH-C) and expressing the recombinant enzyme in bacteria. The chimeric junction was created at proline 165 in TH and proline 106 in TPH because this residue is within a conserved five amino-acid span (ValProTrpPhePro) that defines the beginning of the highly homologous catalytic domains of TH and TPH. Radioenzymatic activity assays demonstrated that the TH-R/TPH-C chimera hydroxylates tryptophan, but not tyrosine. Therefore, the regulatory domain does not confer substrate specificity. Although the TH-R/TPH-C enzyme did serve as a substrate for protein kinase (PKA), activation was not observed following phosphorylation. Phosphorylation studies in combination with kinetic data provided evidence that TH-R does not exert a dominant influence on TPH-C. Stability assays revealed that, whereas TH exhibited a t_1/2 of 84 min at 37°C, TPH was much less stable (t _1/2=28.3 min). The stability profile of TH-R/TPH-C, however, was superimposable on that of TH. Removal of the regulatory domain (a deletion of 165 amino acids from the N-terminus) of TH rendered the catalytic domain highly unstable, as demonstrated by at _1/2 of 14 min. The authors conclude that the regulatory domain of TH functions as a stabilizer of enzyme activity. As a corollary, the well-characterized instability of TPH may be attributed to the inability of its regulatory domain to stabilize the catalytic domain.