Prevention of ethanol-induced changes in reactive oxygen parameters by alpha-tocopherol.

Rats were given a 200 mg/kg body weight daily dose of alpha-tocopherol by i.p. injection for 15 days.

Chronic inhalation exposure to ozone and nitric acid elevates stress-inducible heat shock protein 70 in the rat lung.

The ability of urban oxidant and acid air pollutants to induce heat shock proteins (HSPs) in the mammalian lung is not known. Such proteins are known to be correlated with environmental stress and pathophysiological conditions. In this study, stress-inducible HSP 70 was assessed by slot-blotting in rat lungs (N=10 per group) following inhalation exposures for 4 h per day, 3 days per week for 40 weeks to the following pollutants: (a) purified air;(b) 0.

Differential induction of immediate early gene proteins in cultured neurons by beta-amyloid (A beta): association of c-Jun with A beta-induced apoptosis.

beta-Amyloid (A beta) is a 39-42 amino acid that is the primary component of plaques in Alzheimer's disease (AD). Previous studies from our laboratory and others have shown that A beta induces neurodegeneration via apoptosis in vitro, suggesting that A beta may also initiate an apoptotic pathway of cell death in AD. Apoptosis has been suggested to proceed by a gene-directed program in several systems.

Calretinin-immunoreactive neurons are resistant to beta-amyloid toxicity in vitro.

The molecular pathways by which beta-amyloid protein (A beta) induces neurotoxicity in vitro are unknown. We report that cultured hippocampal neurons exhibiting immunoreactivity for the calcium binding protein calretinin are relatively resistant to degeneration resulting from exposure to either beta 25-35 or beta 1-42. These findings suggest that intrinsic characteristics of calretinin cells, possibly including enhanced calcium buffering capacity, underlie the resistance of these cells to A beta toxicity in vitro and perhaps similar insults in Alzheimer's disease.

Immunohistochemical evidence for apoptosis in Alzheimer's disease.

Recently, in vitro studies conducted in our laboratory and others have suggested that apoptosis may have a role in the neuronal cell death associated with Alzheimer's disease (AD). To evaluate this hypothesis, the hippocampi and entorhinal cortices of AD, aged control, and surgical biopsy tissue were examined using the ApopTag system for the detection of DNA fragmentation and DNA strains to reveal nuclear morphology. Numerous neuronal nuclei displaying distinct morphological characteristics of apoptosis were present within tangle-bearing neurons as well as non-tangle-bearing neurons in AD brain, whereas few or no such nuclei were detected in control brain.

Early phosphorylation of tau in Alzheimer's disease occurs at Ser-202 and is preferentially located within neurites.

Within the neurofibrillary tangles (NFTs) and dystrophic neurites (DNs) of Alzheimer's disease (AD), the cytoskeletal protein tau is abnormally hyperphosphorylated. In this study we evaluate the phosphorylation of specific residues on tau within different phases of the formation of NFTs. Two monoclonal antibodies, AT8 and PHF-1, were used to selectively recognize phosphorylated Ser-202 and Ser-396 of PHF-tau protein, respectively.

Selective increase of NMDA-sensitive glutamate binding in the striatum of Parkinson's disease, Alzheimer's disease, and mixed Parkinson's disease/Alzheimer's disease patients: an autoradiographic study.

Parkinson's disease (PD) and Alzheimer's disease (AD) may share certain abnormalities since a subset of PD patients suffer from dementia, and some AD individuals show extrapyramidal symptoms. In vitro quantitative autoradiography was used to examine different subtypes of excitatory amino acid (EAA) receptors (NMDA, KA, and AMPA) and dopamine transporter sites in the striatum (caudate, putamen) and nucleus accumbens (NAc) from idiopathic PD, pure AD, and mixed PD/AD patients. PD and AD groups, and to a lesser extent the PD/AD groups, showed substantially increased binding to NMDA receptors in the striatum and NAc.

Ultrastructural analysis of beta-amyloid-induced apoptosis in cultured hippocampal neurons.

Following treatment with the beta-amyloid (A beta) 25-35 analog, scanning and transmission electron microscopy were used to investigate the morphological changes in cultured hippocampal neurons during the course of degeneration. Ultrastructural analysis revealed focal cell surface blebbing and rapid condensation of nuclear chromatin. Changes in cytoplasmic morphology included prominent vacuole formation, dispersal of polyribosome rosettes and the disappearance of the golgi complex, smooth endoplasmic reticulum and microtubules with increased cytoplasmic electron density.

Pharmacological dissociation of glutamatergic metabotropic signal transduction pathways in cortical astrocytes.

Using cultured cortical astrocytes we demonstrate differential activation of metabotropic signal transduction pathways with 1-aminocyclopentane-trans-1S3R-dicarboxylic acid (1S3R-ACPD) and the glutamate transport inhibitor trans-2,4-pyrrolidine dicarboxylic acid (trans-2,4-PDC). Phosphoinositide hydrolysis was more potently stimulated by 1S3R-ACPD than by L-trans-2,4-PDC; however, L-trans-2,4-PDC was far more efficacious than 1S3R-ACPD at inhibiting cyclic AMP accumulation. The metabotropic receptor antagonist (+)-alpha-methyl-4-carboxyphenylglycine ((+)-MCPG) inhibited 1S3R-ACPD stimulation of phosphoinositide hydrolysis but not its ability to inhibit cyclic AMP accumulation thereby demonstrating a means to pharmacologically dissociate these two metabotropic signal transduction pathways in astrocytes.

Decreased levels of C1q in cerebrospinal fluid of living Alzheimer patients correlate with disease state.

Recent reports that complement proteins comprising the classical pathway are associated with senile plaques suggest that activation of the classical complement cascade in Alzheimer's disease tissue results in bystander cell lysis and may contribute to AD neuropathology. Analysis of cerebrospinal fluid may prove to be a useful means of detecting changes in immunological activity in the brain. We use an enzyme-linked immunosorbent assay to measure levels of C1q, a subunit of the classical complement cascade, in the CSF of patients clinically diagnosed with possible or probable AD.

Down regulation of nestin by TGF-beta or serum in SFME cells accompanies differentiation into astrocytes.

The serum-free mouse embryo (SFME) cell line, derived from 16-day-old mouse embryos in medium in which serum was replaced by growth factors and other supplements, has been cultured for more than 200 generations. SFME cells are nontumorigenic, lack gross chromosomal abnormalities, and display characteristics of CNS progenitor cells. SFME cells show reversible induction of the astrocyte-specific marker glial fibrillary acidic protein when cultured in the presence of TGF-beta or serum.

Contribution of hepatic cytochrome P450 systems to the generation of reactive oxygen species.

The rate of generation of reactive oxygen species (ROS) in hepatic microsomes was assayed using a fluorescent probe. This rate was stimulated in a manner proportional to the concentration of NADPH present. NADH could not be substituted for NADPH, and an inhibitor of mixed-function oxidases (SKF 525A) blocked stimulation by NADPH.

Analysis of brain injury following intrahippocampal administration of beta-amyloid in streptozotocin-treated rats.

It has been suggested that the vulnerability of the aged brain to Alzheimer's disease (AD) pathogenesis depends on a number of risk factors, including abnormal glycolytic metabolism and beta-amyloid accumulation. Intrahippocampal injections of beta-amyloid and related peptides were administered to chronically hyperglycemic rats to examine beta-amyloid toxicity and the interaction with imbalances of glucose metabolism. Chronic hyperglycemia was induced by systemic injection of streptozotocin (STZ) which selectively destroys pancreatic beta-islet cells.

Subpopulations of dystrophic neurites [correction of neuritis] in Alzheimer's brain with distinct immunocytochemical and argentophilic characteristics.

Using two monoclonal antibodies, tau-1 and PHF-1, and a sequential staining method combining double-labeling immunofluorescence and Bielschowsky silver staining, we have demonstrated the presence of two populations of dystrophic neurites (DNs) with distinct immunocytochemical and argentophilic characteristics. Tau-1 and PHF-1 immunoreactivity were co-localized in many DNs. However, approximately 20% of the DNs were immunoreactive for PHF-1 only.

Carbachol increases intracellular free calcium in cultured rat microglia.

Microglia are resident macrophages in the CNS and have been shown to exhibit immune system responses common to other macrophages, including phagocytosis, secretion of superoxide anions, and secretion of regulatory and trophic factors such as interleukin-1. Phagocytosis and oxidative burst by macrophages are often reported to be preceded by an increase in cytosolic free calcium. In addition, a variety of compounds, including neuroactive peptides, have been shown to elicit such calcium responses in various macrophage preparations.

Apoptosis is induced by beta-amyloid in cultured central nervous system neurons.

The molecular mechanism responsible for the neurodegeneration in Alzheimer disease is not known; however, accumulating evidence suggests that beta-amyloid peptide (A beta P) contributes to this degeneration. We now report that synthetic A beta Ps trigger the degeneration of cultured neurons through activation of an apoptotic pathway. Neurons treated with A beta Ps exhibit morphological and biochemical characteristics of apoptosis, including membrane blebbing, compaction of nuclear chromatin, and internucleosomal DNA fragmentation.

Chronic haloperidol treatment enhances binding to NMDA receptors in rat cortex.

Hyperactivity of the dopaminergic system and a hypoglutamatergic state have been hypothesized to underlie schizophrenia. It has also been proposed that neuroleptics may interact not only with the dopaminergic system but also with the glutamatergic system. We found that daily intraperitoneal injections of haloperidol (1 mg kg-1) for 21 days resulted in increased binding (10-20%) to the NMDA type of glutamate receptors in the outer layers of rat parietal cortex.

Increased sensitivity to adenosine in the rat dentate gyrus molecular layer two weeks after partial entorhinal lesions.

The molecular layer of the dentate gyrus exhibits extensive circuit and receptor reorganization after entorhinal lesions and in Alzheimer's disease, including decreased adenosine (A1) receptor binding in the terminal zone of damaged perforant path fibers. We examined the adenosine-sensitivity of evoked synaptic activity recorded from the rat dentate gyrus molecular layer in hippocampal slices prepared after electrolytic lesions were placed in approximately the middle third of the entorhinal cortex. Extracellular field potentials (EFPs) recorded in slices prepared from animals two days post-lesion were small, upward-going, and exhibited paired-pulse potentiation, but by two weeks post-lesion EFPs had recovered to large, downward-going responses that exhibited paired-pulsed depression.

Excitatory amino acid receptors in schizophrenia.

Growing evidence suggests an involvement of excitatory amino acid (EAA) systems in schizophrenia. Precedent exists for changes in binding to kainate, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, N-methyl-D-aspartate subtypes of EAA receptors. Current evidence indicates that in schizophrenia, EAA receptor levels can be decreased, unchanged, or even increased in certain brain regions and certain cases.

beta-Amyloid neurotoxicity: a discussion of in vitro findings.

Significant advances in Alzheimer's disease (AD) research require definitive, reproducible findings from all employed paradigms. Recently, the existing in vitro data addressing the possible contribution of beta-amyloid protein to AD neuropathology have been the subject of controversy. We summarize and interpret existing data and discuss relevant methodological issues.

Gliotoxic properties of the Lathyrus excitotoxin beta-N-oxalyl-L-alpha,beta-diaminopropionic acid (beta-L-ODAP).

beta-N-Oxalyl-L-alpha,beta-diaminopropionic acid (beta-L-ODAP) is an excitatory amino acid agonist found in the seeds of Lathyrus sativus that is believed to be the major causative agent in the pathology of human lathyrism. We have found that in addition to its previously recognized neurotoxic properties, beta-L-ODAP is also gliotoxic. When added to cultures of neonatal rat astrocytes, beta-L-ODAP induced a series of morphological changes (e.

Histochemical and immunocytochemical compartments of the thalamic VPM nucleus in monkeys and their relationship to the representational map.

The ventral posteromedial nucleus (VPM) of the monkey thalamus was investigated with correlative anatomical and physiological techniques. On the basis of staining for cytochrome oxidase (CO), VPM is divided into a lightly stained, background matrix domain and an intensely stained rod domain. The latter consists of elongated rods of large, medium, and small cells, 500 microns wide on average and extending anteroposteriorly, many of them through the full extent of the nucleus.

Histochemical localization of cytochrome oxidase in the retina and optic tectum of normal goldfish: a combined cytochrome oxidase-horseradish peroxidase study.

Cytochrome oxidase (C.O.) was histochemically localized in the normal retina and optic tectum of goldfish in order to examine the laminar and cellular oxidative metabolic organization of these structures.

Oscillatory chloride current evoked by temperature jumps during muscarinic and serotonergic activation in Xenopus oocyte.

1. Membrane currents were recorded from voltage-clamped oocytes of Xenopus laevis, during temperature jumps imposed by a heating light. Resting oocytes usually showed little response, but large oscillatory membrane currents developed in response to cooling steps applied during activation of 'native' muscarinic receptors.