Peroxisome proliferator-activated receptor gamma agonists protect cerebellar granule cells from cytokine-induced apoptotic cell death by inhibition of inducible nitric oxide synthase.

Cerebellar granule cells (CGCs) can express the inducible isoform of nitric oxide synthase (iNOS) in response to inflammatory stimuli. We demonstrate that induction of iNOS in CGCs by bacterial lipopolysaccharide and pro-inflammatory cytokines results in cell death that was potentiated by excess L-arginine and inhibited by the selective iNOS inhibitor, 2-amino-5,6-dihydro-6-methyl-4H-1,3-thiazine. The NO-mediated cell death was accompanied by increased caspase-3-like activity, DNA fragmentation and positive terminal transferase dUTP nick end labeling (TUNEL), suggesting that apoptosis mediates CGC cell death.

Nitric-oxide-dependent pial arteriolar dilation in the female rat: effects of chronic estrogen depletion and repletion.

In this study, we compared endothelial nitric oxide synthase (eNOS)-mediated cerebral vasodilating responses in intact female rats, chronically ovariectomized (OVX) rats, and OVX rats treated for 2 weeks with 17beta-estradiol (E(2)). Under anesthesia, using intravital microscopy and a closed cranial window system, pial arteriolar diameter changes were monitored during sequential cortical suffusions of an eNOS-dependent dilator [acetylcholine (ACh)] and a direct NO donor [S-nitrosoacetylpenicillamine (SNAP)]. In separate rats from the same groups, we compared eNOS and caveolin-1 (CAV-1) protein abundance in pial arterioles (via immunofluorescence analyses).

Regulation of the expression of the inflammatory nitric oxide synthase (NOS2) by cyclic AMP.

The enzyme nitric oxide synthase 2 (NOS2), often called inducible NOS, plays a central role in the inflammatory reactions that follow infection or tissue damage. NOS2 has been detected in virtually every cell type, and the NO it produces can perform both beneficial and detrimental actions. It is thus conceivable that regulatory mechanisms exist which control the timing and intensity of NO production by NOS2 in order to outweigh protective effects against detrimental ones.

Anti-proliferative and anti-inflammatory actions of imidazoline agents. Are imidazoline receptors involved?

We have shown that cultured vascular smooth muscle cells (VSMC) and brain astroglial cells express I-receptors of the I2 subtype. While imidazoline agents are anti-proliferative in smooth muscle cells, they increase the expression of glial fibrillary acidic protein (GFAP) in astrocytes. Because increases in GFAP suppress the induction of calcium-independent, inducible nitric oxide synthase (NOS-2), we measured whether idazoxan and related imidazolines and agmatine would also suppress the expression of NOS-2.

ERGIC-53 gene structure and mutation analysis in 19 combined factors V and VIII deficiency families.

Combined factors V and VIII deficiency is an autosomal recessive bleeding disorder associated with plasma levels of coagulation factors V and VIII approximately 5% to 30% of normal. The disease gene was recently identified as the endoplasmic reticulum-Golgi intermediate compartment protein ERGIC-53 by positional cloning, with the detection of two founder mutations in 10 Jewish families. To identify mutations in additional families, the structure of the ERGIC-53 gene was determined by genomic polymerase chain reaction (PCR) and sequence analysis of bacterial artificial chromosome clones containing the ERGIC-53 gene.

Inhibition of astroglial nitric oxide synthase type 2 expression by idazoxan.

Binding of idazoxan (IDA) to imidazoline receptors of the I2 subtype in astrocytes influences astroglial gene expression as evidenced by increased expression of glial fibrillary acidic protein and mRNA. To determine whether IDA affected glial inflammatory gene expression, we tested the effects of IDA on astroglial nitric oxide synthase type-2 (NOS-2) expression. NOS-2 was induced in primary rat astrocytes and C6 glioma cells by incubation with 1 microgram/ml lipopolysaccharide (LPS) plus three cytokines (tumor necrosis factor-alpha, interleukin-1beta, and interferon-gamma) or three cytokines alone.

Stimulation of cerebellar fastigial nucleus inhibits interleukin-1beta-induced cerebrovascular inflammation.

Electrical stimulation of the cerebellar fastigial nucleus (FN) in rat protects the brain against ischemia. We studied whether FN could reduce the cerebrovascular inflammation as a mechanism of protection. FN or dentate nucleus (sham controls) was electrically stimulated for 1 h, and 72 h later rats were either injected with interleukin (IL)-1beta into the striata or processed to analyze inflammatory responses in isolated brain microvessels.

The bacterial endotoxin lipopolysaccharide has the ability to target the brain in upregulating its membrane CD14 receptor within specific cellular populations.

Systemic injection of the bacterial endotoxin lipopolysaccharide (LPS) provides a very good mean for increasing the release of proinflammatory cytokines by circulating monocytes and tissue macrophages. There is now considerable evidence that LPS exerts its action on mononuclear phagocytes via the cell surface receptor CD14. The aim of the present study was to verify the hypothesis that the brain has also the ability to express the gene encoding the LPS receptor, which may allow a direct action of the endotoxin onto specific cellular populations during blood sepsis.

Structure and upstream region characterization of the human gene encoding rod photoreceptor cGMP phosphodiesterase alpha-subunit.

Rod photoreceptor cGMP phosphodiesterase (PDE6) is a three-subunit (a, b, g2) enzyme that functions to reduce intracellular cytoplasmic cGMP levels, an integral feature of the phototransduction cascade of vision. To allow assessment of the potential for defects in the gene encoding the alpha-subunit (PDE6A) to cause visual dysfunction, and to begin to dissect the basis for photoreceptor-specific expression of this gene, we have characterized the structural gene and upstream region. The human PDE6A gene consists of 22 exons spanning about 60 kb with the intron/exon junctions highly conserved in comparison to the mouse and human PDE6B genes.

Methodologic standards for diagnostic test research in pulmonary medicine.

Study Objectives: To determine conformance with methodologic standards in the evaluation of diagnostic tests.

Data Sources: MEDLINE database search (1992 to 1997) of nine prominent general medicine and six subspecialty journals for articles that report discriminative properties of diagnostic tests in pulmonary medicine.

Study Selection: Articles were eligible if they reported discriminative properties of diagnostic tests in humans, diagnostic tests were intended for the detection of existing conditions, and the target disorder was relevant to pulmonary medicine.

Potentiation of astroglial nitric oxide synthase type-2 expression by lithium chloride.

The mechanisms underlying the antimanic effects of lithium are largely unknown but may involve long-term changes in brain gene expression. To determine if lithium could modify gene expression in astrocytes, the predominant cell type in brain, we tested the effects of LiCl on expression of nitric oxide synthase type 2 (NOS-2) in cultured glial cells. Incubation of primary rat astrocytes with endotoxin [lipopolysaccharide (LPS)] and proinflammatory cytokines induced NOS-2 gene and protein expression, as assessed by nitrite production and measurement of L-citrulline synthesis in whole cell lysates.

Cerebellar stimulation reduces inducible nitric oxide synthase expression and protects brain from ischemia.

A focal infarction produced by occlusion of the middle cerebral artery (MCAO) in spontaneously hypertensive rats induced expression of inducible nitric oxide synthase (iNOS) mRNA, measured by competitive reverse transcription-polymerase chain reaction. The mRNA appeared simultaneously in the ischemic core and penumbra at 8 h, peaked between 14 and 24 h, and disappeared by 48 h. At 24 h, inducible nitric oxide synthase (iNOS)-like immunoreactivity was present in the endothelium of cerebral microvessels and in scattered cells, probably representing leukocytes or activated microglia.

Central neurogenic neuroprotection: central neural systems that protect the brain from hypoxia and ischemia.

The brain can protect itself from ischemia and/or hypoxia by two distinct mechanisms which probably involve two separate systems of neurons in the CNS. One, which mediates a reflexive neurogenic neuroprotection, emanates from oxygen-sensitive sympathoexcitatory reticulospinal neurons of the RVLM. These cells, excited within seconds by reduction in blood flow or oxygen, initiate the systemic vascular components of the oxygen conserving (diving) reflex.

Metabolism of agmatine in macrophages: modulation by lipopolysaccharide and inhibitory cytokines.

Agmatine is an amine derived from the decarboxylation of arginine by arginine decarboxylase (ADC) and metabolized to putrescine by agmatinase. While prevalent in bacteria and plants, agmatine and its metabolic enzymes have been recently identified in mammalian tissues. In the present study we sought to determine: (a) whether macrophages (cell line RAW 264.

Treatment of a unique anemia in patients with IDDM with epoetin alfa.

Objective: To identify and treat a unique form of anemia in patients with long-term IDDM.

Research Design And Methods: Patients with IDDM, unexplained symptomatic anemia, and serum creatinine levels of < 177 mumol/l (2.0 mg/dl) were treated with epoetin alfa (Procrit, Ortho Biotech, Raritan, NJ), 50 U/kg three times weekly, subcutaneously, to reach a target hematocrit of 38-40%.

Suppression of astroglial nitric oxide synthase expression by norepinephrine results from decreased NOS-2 promoter activity.

We previously demonstrated that norepinephrine (NE) inhibits induction of the calcium-independent isoform of nitric oxide synthase (NOS-2) in primary rat astrocyte cultures. However, the molecular mechanisms underlying this effect are unknown. In C6 cells and astrocytes, NE suppressed both cytokine- and lipopolysaccharide (LPS)-dependent nitrite accumulation, an index of NOS-2 activity.

Personal mythology and psychotherapy: myth-making in psychological and spiritual development.

The sweeping changes and crises in the guiding myths of contemporary cultures provide the context of the individual's psychological and spiritual development. A five-stage process for facilitating the evolution of an individual's personal mythology is illustrated in a detailed case study, and the psychosocial tasks that must be accomplished to successfully navigate each stage are discussed.

Suppression of glial nitric oxide synthase induction by heat shock: effects on proteolytic degradation of IkappaB-alpha.

Rat C6 glioma cells were stably transfected with a human cDNA encoding heat shock protein (HSP)70. Immunostaining revealed the presence of largely cytosolic HSP70 in C6-hsp70 cells, but not in control (vector transfected) C6-pTK cells. Induction of nitric oxide synthase (NOS-2) expression in C6-hsp70 cells, assessed by nitrite accumulation, was significantly reduced compared to control C6-pTK cells (25+/-8% of control cell induction, P < 0.

Suppression by ethanol of inducible nitric oxide synthase expression in C6 glioma cells.

Exposure to lipopolysaccharide (LPS) combined with phorbol-12-myristate-13-acetate (PMA) stimulates de novo synthesis of inducible nitric oxide synthase (NOS-2) in C6 glioma cells. Ethanol dose-dependently inhibits C6 cell NOS-2 activity, as measured by nitrite accumulation in culture medium, when present during LPS plus PMA treatment. The present study reports on mechanisms related to this inhibition.

Norepinephrine suppresses L-arginine uptake in rat glial cells.

Incubation of rat astrocytes or C6 glioma cells with norepinephrine (NE) suppresses bacterial endotoxin and cytokine-dependent induction of calcium-independent nitric oxide synthase (Feinstein et al., J. Neurochem.

Unresolved issues in laparoscopic splenectomy.

Background: Laparoscopy is now expanding to surgery of intra-abdominal solid organs such as splenectomy for hematologic diseases. The purpose of this study is to further demonstrate that laparoscopic splenectomy is feasible for the surgeon, teachable for the resident, and beneficial to the patient and to revise prior contraindications to this minimally invasive approach.

Methods: Thirty-three consecutive cases of laparoscopic splenectomy were performed between May 1992 and March 1996.

Heat shock protein 70 suppresses astroglial-inducible nitric-oxide synthase expression by decreasing NFkappaB activation.

In brain glial cells, expression of calcium independent nitric-oxide synthase (NOS-2) is induced following stimulation with bacterial endotoxin (lipopolysaccharide (LPS)) and/or pro-inflammatory cytokines. We have investigated the effects of heat shock (HS), which can reduce inflammatory responses in several cell types, on the induction of glial NOS-2 expression. Preincubation of cells for 20-60 min at 43 degrees C decreased subsequent levels of NOS-2 induction, with a maximal 80% reduction after 60 min of HS.

Gene structure and chromosome localization to 7q21.3 of the human rod photoreceptor transducin gamma-subunit gene (GNGT1).

The transducin gamma-subunit gene (GNGT1) encodes a member (gamma1) of the family of heterotrimeric G-protein gamma-subunits that is specific to rod photoreceptors. In this report we have determined the complete structure of the GNGT1 gene and have localized it to human chromosome 7q21.3 using somatic cell hybrid and yeast artificial chromosome analysis.