Quantitative assessment of ALZ-50 immunoreactivity in Alzheimer's disease.

A quantitative assay for ALZ-50 immunoreactivity was evaluated in samples of superior temporal gyrus taken at autopsy from 13 Alzheimer patients and 11 controls. The assayable immunoreactivity appears to be stable for at least 24 hours postmortem but was lost with formalin fixation. The mean value of the Alzheimer patients was tenfold higher than that of the controls (P less than .002). The values of four Alzheimer samples overlapped with the low levels seen in controls, but no controls had elevated levels. In this sample population, therefore, the assay had a sensitivity of 69% and specificity of 100%.     

Toxicity of polycyclic aromatic hydrocarbons. III. Effects of beta-naphthoflavone pretreatment on hepatotoxicity of compounds produced in the ozonation or NO2-nitration of phenanthrene and pyrene in rats

Male Sprague-Dawley rats were treated ip with beta-naphthoflavone (BNF, 40 mg/kg/day) in dimethylsulfoxide (DMSO, 26.7 mg BNF/ml) for three days. At 24 hr after the pretreatment DMSO (3.0 ml/kg), phenanthrene (150 mg/kg), ozonized or nitrated products of phenanthrene (150 mg/kg), pyrene (150 mg/kg), or ozonized or nitrated products of pyrene (150 mg/kg) were injected ip. Phenanthrene, pyrene, and their ozonized or nitrated products were dissolved in DMSO (50 mg/ml). No increase in the level of aspartate aminotransferase (AST), alanine aminotransferase (ALT) or sorbitol dehydrogenase (SDH) was seen in the pretreated rats 48 hr after the treatment. This is in contrast to what was seen in previous work without the BNF pretreatment. BNF pretreatment induced a small but significant increase in gamma-glutamyl transpeptidase (GGTP) levels. No treatment group receiving BNF differed from another with respect to GGTP. A decrease in lactate dehydrogenase (LDH) levels was noted in the nitro-PAH treatment groups; the same phenomenon was observed earlier in rats treated with nitro-PAH without BNF treatment. These results suggest that the mixed-function oxidase systems specifically induced by BNF have a protective effect against the hepatotoxicity of the oxonized or nitrated products of phenanthrene and pyrene.     

The influence of adrenergic and cholinergic agents on the chemiluminescent and mitogenic responses of leukocytes from the rainbow trout, Oncorhynchus mykiss

In a previous report, it was shown that agonists of cholinergic or alpha-adrenergic receptors enhance, whereas beta-adrenergic agonists suppress, in vitro antibody responses by splenic leukocytes from rainbow trout. The present study addresses the mechanisms by which autonomic neurotransmitters (or their analogs) could affect this antibody response. Possibilities include an influence on accessory cell function, on the clonal proliferation of antigen-stimulated lymphocytes, and/or on the synthesis and secretion of antibody. Epinephrine and selective beta-adrenergic agonists suppressed whereas both alpha and cholinergic receptor agonists enhanced the ability of stimulated pronephric leukocytes (mainly macrophages and neutrophils) to produce reactive oxygen species, suggesting that accessory cells may be a target of these agents in the antibody response. Beta-adrenergic agonists also suppressed the proliferative response of splenic leukocytes to LPS, Con A, and PHA. There was no effect, however, of alpha-adrenergic or cholinergic-receptor agonists on mitogenic responses.     

Coreceptor Switch of [MLV(SIVagm)] pseudotype vectors by V3-loop exchange

Retroviral vectors derived from murine leukemia virus (MLV) have been pseudotyped with a variant of the envelope glycoprotein (Env) of nonpathogenic simian immunodeficiency virus from African green monkeys (SIVagm) to result in [MLV(SIVagm-wt)] vector particles. The variant env gene encodes a full-length surface envelope glycoprotein (SU) and a C-terminally truncated transmembrane protein (TM). To change the coreceptor usage of this vector from CCR5 to CXCR4, which is predominant on human CD4-positive lymphocytes, the putative V3-loop of SIVagm SU was replaced by that of the T cell tropic HIV-1 variant BH10. The resulting [MLV(SIVagm-X4)] vectors were shown to specifically transduce CD4/CXCR4-positive cell lines, demonstrating the equivalent function in cell entry and choice of coreceptor usage of the V3-loops of SIVagm and HIV-1. These modified vectors were able to transduce primary human lymphocytes and were resistant to neutralization by sera from HIV-1-infected individuals. The [MLV(SIVagm-X4)] pseudotype vector generated is thus a promising candidate vector, e.g., for in vivo gene therapy of HIV-1 infection.     

The membrane attack complex of complement induces interleukin-8 and monocyte chemoattractant protein-1 secretion from human umbilical vein endothelial cells.

Cell surface assembly of the membrane attack complex (MAC) of complement occurs in a variety of pathophysiological settings. Depending upon the density and size distribution of pores formed by the MAC and the functional integrity of membrane regulators of complement activation, the MAC can either cause direct cell lysis or transduce cell activation. We have examined the functional capacity of sublytic concentrations of MAC to induce the secretion of specific alpha- and beta-chemokines from human umbilical vein endothelial cells (HUVECs). Endothelial cell activation by the MAC has particular relevance to complement-dependent inflammatory processes including ischemia-reperfusion injury and acute lung injury. Assembly of sublytic concentrations of the MAC on HUVECs resulted in the sequential secretion of both neutrophil and monocyte chemotactic activities. Analysis of conditioned medium from MAC-bearing HUVECs revealed that the neutrophil chemotactic activity was largely attributable to interleukin (IL)-8, whereas the monocyte chemotactic activity, which was detected later (peak at 8 hours versus 4 hours), was largely attributable to MCP-1. This temporal pattern of MAC-induced secretion of IL-8 and MCP-1 was confirmed using IL-8- and MCP-1-specific enzyme-linked immunosorbent assays. Northern hybridization analysis of HUVECs revealed that MAC deposition was accompanied by an increase in IL-8 and MCP-1 mRNA levels. These data indicate that assembly of sublytic concentrations of the MAC on HUVECs can induce the sequential secretion of both neutrophil and monocyte chemotactic activities and that the former is largely attributable to IL-8 whereas the latter is largely attributable to MCP-1.     

Caspase inhibitors induce a switch from apoptotic to proinflammatory signaling in CD95-stimulated T lymphocytes

CD95 is a major apoptosis receptor that induces caspase activation and programmed cell death in susceptible cells. CD95-induced apoptosis can be blocked by peptidic caspase inhibitors such as benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone or Ile-Glu-Thr-Asp-fluoromethyl ketone. Here we show that stimulation of CD95 in the presence of these inhibitors induces necrosis and expression of various proinflammatory cytokines in primary T lymphocytes, such as TNF-alpha, IFN-gamma and granulocyte/macrophage colony-stimulating factor. In the absence of caspase inhibition CD95 stimulation did not result in cytokine expression, indicating that this proinflammatory signaling pathway is suppressed by active caspases. Further analysis with A3.01 T cells revealed that the proinflammatory signaling activity of CD95 was mediated by MEK/ERK, p38 and NF-kappaB signaling pathways. These findings point to a pivotal role of caspases not only as mediators of apoptosis but also as enzymes that prevent proinflammatory signaling during CD95-induced apoptosis. Moreover, our findings may be useful for the development of novel pharmacological strategies.     

The topographical and neuroanatomical distribution of neurofibrillary tangles and neuritic plaques in the cerebral cortex of patients with Alzheimer's disease.

The distribution of neurofibrillary tangles (NFTs) and neuritic plaques (NPs) was mapped in 39 cortical areas of 11 brains of patients with Alzheimer's disease (AD). Whole hemisphere blocks were embedded in polyethylene glycol (Carbowax), sectioned coronally, and stained with thioflavin S and thionin. The densities of NFTs and NPs were assessed using a numerical rating scale for each area. Scores were grouped by type of cortex and by lobe for statistical analysis. Highly significant differences were obtained. For example, limbic periallocortex and allocortex had more NFTs than any other type of cortex. In descending order, the density of NFTs was as follows: periallocortex (area 28) greater than allocortex (subiculum/CA1 zones of hippocampal formation, area 51) greater than corticoid areas (accessory basal nucleus of amygdala, nucleus basalis of Meynert) greater than proisocortex (areas 11, 12, 24, 23, anterior insula, 38, 35) greater than nonprimary association cortex (32, 46, superior temporal sulcus, 40, 39, posterior parahippocampal cortex, 37, 36) greater than primary sensory association cortex (7, 18, 19, 22, 21, 20) greater than agranular cortex (44-5, 8, 6, 4) greater than primary sensory cortex (41-2, 3-1-2, 17). The laminar distribution of NFTs tended to be selective, involving primarily layers III and V of association areas and layers II and IV of limbic periallocortex. There were far more NFTs in both limbic and temporal lobes than in frontal, parietal, and occipital lobes. In general, NPs were more evenly distributed throughout the cortex, with the exceptions of limbic periallocortex and allocortex, which had notably fewer NPs than other cortical areas. Temporal and occipital lobes had the highest NP densities, limbic and frontal lobes had the lowest, and parietal lobe was intermediate. No significant left-right hemispheric differences for NFT or NP densities were found across the population, and there was no relationship between duration of illness and densities of NFTs or NPs. The regional and laminar distribution of NFTs (and, to a lesser degree, that of NPs) suggests a consistent pattern of vulnerability within the cerebral cortices that seems correlated to the hierarchies of cortico-cortical connections. The higher-order association cortices, especially those in the anterior and ventromedial sectors of temporal lobe, are the most vulnerable, while other cortices appear less vulnerable to a degree commensurate with their connectional "distance" (i.e., synapses removed) from the limbic areas.