Fatal avulsion of choroidal or perforating arteries by guidewires. Case reports, ex vivo experiments, potential mechanisms and prevention.

Innovations in endovascular tools have permitted an increasingly broad range of neurovascular lesions to be treated via minimally invasive methods. However, some device modifications may carry additional risks, not immediately apparent to operators. A patient with a symptomatic, partially thrombosed basilar apex aneurysm was allocated balloon-assisted coiling.

Development of a site-directed polyclonal antibody against the pituitary growth hormone-releasing hormone receptor and its use to estimate GHRH receptor concentration in normal and hypothyroid rats.

A site-directed polyclonal antipeptide antibody was generated in rabbits against segment 392-404 of the rat pituitary growth hormone-releasing hormone receptor (GHRH-R), using a multiple antigenic peptide system strategy of immunization. This C-terminal intracellular region of the rat GHRH-R exhibits 85% sequence identity with the human GHRH-R. The purified anti-GHRH-R(392-404) IgGs were characterized in cell lines expressing the human GHRH-R and in rat and human anterior pituitary, using immunoblotting.

Differential in vivo regulation of the pituitary growth hormone-releasing hormone (GHRH) receptor by GHRH in young and aged rats.

In aging, alterations of pituitary GH-releasing hormone (GHRH) receptor (GHRH-R)-binding sites have been proposed as one of the initiating factors contributing to the loss of somatotroph responsiveness to GHRH. Changes in the characteristics and/or concentration of the functional GHRH-R could take place in the course of aging and reduce the sensitivity of the somatotroph axis to GHRH. Because chronic exposure to GHRH has been proposed to resensitize aged somatotroph cells, better knowledge of its effects on the regulation of the somatotroph axis is required, particularly at the level of GHRH-R.

Gliclazide decreases cell-mediated low-density lipoprotein (LDL) oxidation and reduces monocyte adhesion to endothelial cells induced by oxidatively modified LDL.

Low-density lipoprotein (LDL) oxidation has been suggested to play a key role in the pathogenesis of atherosclerosis, a major complication of diabetes mellitus. Gliclazide, a second-generation sulfonylurea, is widely used in the treatment of type II diabetes mellitus. Recently, a free-radical-scavenging activity of gliclazide has been reported.

Direct stimulatory effect of insulin-like growth factor-I on monocyte and macrophage tumor necrosis factor-alpha production.

GH has been demonstrated to play a physiological role in the priming of macrophages for tumor necrosis factor-alpha (TNF alpha) synthesis. Although evidence has been presented that GH exerts this effect by an indirect mechanism, the mediators of GH stimulation of TNF alpha synthesis have not been identified. Because insulin-like growth factor-I (IGF-I) is a major mediator of many GH effects, in the present study we investigated the direct in vitro effect of this growth factor on macrophage TNF alpha production.

Role of oxidant injury on macrophage lipoprotein lipase (LPL) production and sensitivity to LPL.

We investigated, in the present study, the role of reactive oxygen intermediates (ROI) in the control of macrophage lipoprotein lipase (LPL) secretion. Exposure of murine macrophages to increasing concentrations of hydrogen peroxide (H2O2) resulted in enhanced basal LPL production and mRNA levels. The increase of LPL production was reduced in the presence of antioxidants.

Expression of human mitochondrial NADP-dependent isocitrate dehydrogenase during lymphocyte activation.

In the process of identifying genes involved in optimization of lymphocyte activation, we have cloned the human mitochondrial NADP-dependent isocitrate dehydrogenase (mNADP-IDH) cDNA. The cDNA and its deduced amino acid (AA) sequence had a high degree of homology with those of the porcine and bovine. The heart and muscle had the highest constitutive expression of the gene.

Molecular cloning of the cDNA of mouse mitochondrial NADP-dependent isocitrate dehydrogenase and the expression of the gene during lymphocyte activation.

The current report documents the molecular cloning of the mouse mitochondrial NADP-dependent isocitrate dehydrogenase (mNADP-IDH) cDNA. The cDNA was 1,863 bp in length and contained one open reading frame encoding a 523-residue polypeptide with a predicted molecular weight of 58 kDa. The cDNA and the deduced amino acid (AA) sequence of the mouse mNADP-IDH had a high degree of homology with those of porcine, bovine, alfalfa, and yeast.

IL-2 and IL-7 but not IL-12 protect natural killer cells from death by apoptosis and up-regulate bcl-2 expression.

Human natural killer cells (NK) respond to interleukin-2 (IL-2) with augmented cytolytic activity, cytokine secretion and cell proliferation. Here we show that IL-2 protects NK cells from death by apoptosis (programmed cell death; PCD). Highly purified NK cells (CD3- CD56+) were isolated from peripheral blood lymphocytes (PBL) of either control donors or of an asymptomatic donor with 60% NK cells.

Activated T cells induce interleukin-12 production by monocytes via CD40-CD40 ligand interaction.

Previous studies on the production of interleukin-12 (IL-12) have shown that it is released, together with other proinflammatory cytokines, shortly after exposure of phagocytic cells to a variety of pathogens. We here report that IL-12 is also released during the recall response to soluble antigen (Ag) devoid of intrinsic adjuvant activity. We show that activated T cells induce the production of IL-12 by monocytes via a mechanism involving the interaction of T cell-associated CD40 ligand with CD40 on monocytes.

Lipoprotein lipase synergizes with interferon gamma to induce macrophage nitric oxide synthetase mRNA expression and nitric oxide production.

Lipoprotein lipase (LPL) induces macrophage tumor necrosis factor-alpha (TNF-alpha) gene expression and protein secretion. Since TNF-alpha can increase interferon gamma (IFN-gamma)-dependent nitric oxide (NO) production, we studied whether LPL may synergize with IFN-gamma for the induction of macrophage NO production. Although ineffective by itself, LPL in combination with IFN-gamma increased L-arginine-dependent NO production in a dose-dependent manner.

Effects of aging on pituitary growth hormone-releasing factor receptor binding sites: in vitro mimicry by guanyl nucleotides and reducing agents.

We have investigated the effect of 5'-guanylylimidodiphosphate (Gpp(NH)p) and two disulfide bond reducing agents, reduced glutathione (GSH) and dithiothreitol (DTT), on the modulation of [125I-Tyr10]hGRF(1-44)NH2 binding to GRF receptor binding sites, in pituitaries of young and aging rats. In pituitaries from 2-month-old rats, Gpp(NH)p (0.1-1.

The two CD23 isoforms display differential regulation in chronic lymphocytic leukaemia.

B lymphocytes from chronic lymphocytic leukaemia (B-CLL) patients express the two CD23 isoforms (type A and B), which differ only in their intracytoplasmic domain. The abnormal regulation of the CD23 antigen in response to IL-4, IFNs alpha and gamma results in CD23 over-expression on B-CLL cells. Our present study shows that the two CD23 isoforms are differentially and abnormally regulated on B-CLL cells.

In vitro maturation of neonatal human CD8 T lymphocytes into IL-4- and IL-5-producing cells.

Naive CD8 T cells isolated from umbilical cord blood were examined for cytokine production and for surface phenotype before and after priming with anti-CD3 mAb in the presence of selected cytokines. On stimulation with anti-CD3 immobilized on CD32-B7-transfected L cells, naive and primed CD8 T cells release high levels of IFN-gamma but no IL-2, IL-4, or IL-5. IL-12-primed cells, and to a lesser extent IL-2-primed cells, have an increased capacity to produce IFN-gamma but display the same restricted pattern of cytokine production.

Interleukin 12 exerts a differential effect on the maturation of neonatal and adult human CD45R0- CD4 T cells.

It is now recognized that IL-12 plays a predominant role in protective immunity against intracellular pathogens by promoting the development of T helper type 1 (Th1) responses. We here report the unexpected observations that IL-12 exerts differential effects on the maturation of "native" human CD4 T cells isolated from umbilical cord blood or from the blood of healthy adults. After priming in the presence of IL-12, naive cells of adult donors, defined as CD45R0- CD4+ T cells, acquire a Th1 phenotype whereas neonatal cells develop into effector cells producing high levels of IL-4 in addition to IFN-gamma.

Role for low-affinity receptor for IgE (CD23) in normal and leukemic B-cell proliferation.

CD23 gene is overexpressed and abnormally regulated in the most frequent adult leukemic disorder, B chronic lymphocytic leukemia (B-CLL). Switch on and off in the upregulation of surface CD23 expression consistently occurs in the early stage of normal B-cell activation, suggesting a key role for CD23 in this process. We show here that, after ligation of mlg in the presence of interleukin-4, the increase of CD23 protein precedes B-cell DNA synthesis and mainly results from the strong induction of CD23 type-B isoform.

Regulation of cytokine production by soluble CD23: costimulation of interferon gamma secretion and triggering of tumor necrosis factor alpha release.

Soluble CD23 (sCD23) has multiple IgE-independent biological activities. In the present study, we examined the regulatory effect of sCD23 on cytokine production by human peripheral blood mononuclear cells (PBMC). We show that sCD23 enhances by about 80-fold the interleukin 2 (IL-2)-induced interferon gamma (IFN-gamma) production and by about 10-fold the response to IL-12.

The reduced expression of glucocorticoid receptors in synovial cells induced by nonsteroidal antiinflammatory drugs can be reversed by prostaglandin E1 analog.

Objective: We examined the effect of 3 commonly used nonsteroidal antiinflammatory drugs (NSAID), indomethacin, naproxen and tiaprofenic acid, and a prostaglandin E1 analog, misoprostol, on the glucocorticoid receptor level in synovial fibroblasts.

Methods: Synovial fibroblasts were isolated by enzymatic digestion from human normal synovial membranes. These cells were incubated with therapeutic and pharmacological concentrations of NSAID in the presence or absence of misoprostol (0.

Prostaglandins E2 and E1 inhibit cytokine-induced metalloprotease expression in human synovial fibroblasts. Mediation by cyclic-AMP signalling pathway.

Background: Cytokine modulated matrix metalloprotease (MMP, i.e., collagenase and stromelysin) synthesis may be associated etiologically with osteoarthritic diseases.

Induction of tumor necrosis factor alpha gene expression by lipoprotein lipase requires protein kinase C activation.

We have previously found that lipoprotein lipase (LPL) induces tumor necrosis factor alpha (TNF alpha) mRNA expression and TNF alpha protein production in the ANA-1 macrophage cell line and in resident murine macrophages. The present study was designed to elucidate the intracellular signalling pathways involved in the LPL-induced TNF alpha gene expression. Treatment of macrophages with two protein kinase C (PKC) inhibitors, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine hydrochloride (H7) and calphostin C, suppressed LPL-induced TNF alpha mRNA expression and protein production.

Excess of metalloproteases over tissue inhibitor of metalloprotease may contribute to cartilage degradation in osteoarthritis and rheumatoid arthritis.

Background: In an attempt to identify the factor(s) involved in the modulation of the degradative pathway of articular cartilage, we previously reported a possible imbalance between the levels of biologically active forms of metalloproteases and tissue inhibitor of metalloprotease (TIMP) in osteoarthritis (OA) cartilage.

Experimental Design: We extended our analysis on the protein level and the synthesis of stromelysin-1, collagenase, TIMP-1, and TIMP-2 in normal, OA, and RA cartilages, and provided information on the synthesis pattern of these proteins in respect to the action of interleukin-1 (IL-1). These protein concentrations were determined by specific sandwich EIA assays.

In vitro maturation of human neonatal CD4 T lymphocytes. II. Cytokines present at priming modulate the development of lymphokine production.

The development of naive CD4 T cells into type 1 or type 2 Th cells has been extensively analyzed in the mouse. Using neonatal CD4 T lymphocytes as a source of human naive cells, we report that these cells may be induced to differentiate into effector cells producing predominantly Th1 or Th2 cytokines. After 3 days of stimulation with anti-CD3 mAb immobilized on CD32 transfected mouse fibroblasts, followed by 3 days of culture in the presence of IL-2, neonatal cells acquire the phenotypic and functional characteristics of effector cells.

Expression of a G-protein beta subunit-related gene during lymphocyte activation.

Using a subtractive strategy, we have cloned an activation-related gene from a human B cell cDNA library. Sequence analysis revealed that this gene was identical to H12.3, a gene belonging to an expanding family of guanine nucleotide-binding protein beta subunits.

Serum keratan sulfate levels in rheumatoid arthritis: inverse correlation with radiographic staging.

Objective: To correlate the serum levels of keratan sulfate (KS) in patients with rheumatoid arthritis (RA) with different clinical and radiographic variables.

Methods: Serum KS levels were measured in 85 patients with RA and 41 age matched controls. Patients with RA were classified according to their disease activity, the presence of rheumatoid factor, the medication prescribed, and to the severity of the joint radiographic changes.

Identification of receptor-binding pharmacophores of growth-hormone-releasing factor in rat adenopituitary.

Previous structure-activity studies on growth-hormone-releasing factor (GRF) have mainly been carried out in pituitary cell culture assays. In such systems, the molecular features necessary to increase GRF receptor affinity cannot be fully distinguished from those that improve proteolytic resistance. To assess the affinity of GRF analogues, we have recently characterized [125I-Tyr10]hGRF(1-44)NH2 binding to rat adenopituitary, developing a reliable binding assay in which GRF-carboxamide-related peptides are stable.