Potentiation by ATP of lipopolysaccharide-stimulated nitric oxide production in cultured astrocytes.

The functional changes of astrocytes are deeply involved in neurodegenerating processes of various CNS diseases. ATP is released during various neuronal damages such as brain ischemia and may control astrocyte functions. We examined the effect of ATP on the production of nitric oxide in the cultured astrocytes from rat embryo.

Concentration gradient of oxalate from cortex to papilla in rat kidney.

Background: The kidney eliminates the major fraction of plasma oxalate. It is well known that oxalate is freely filtered by glomeruli and secreted by the proximal tubules. However, the renal handling of oxalate in distal nephrons, which is considered as playing an important role in stone formation, remains obscure.

Possible regulation by N-methyl-d-aspartate receptors of proliferative progenitor cells expressed in adult mouse hippocampal dentate gyrus.

An immunohistochemical technique was employed to analyze mechanisms underlying modulation by N-methyl-d-aspartate (NMDA) receptors of proliferation of neural progenitor cells in adult mouse brain. The systemic administration of NMDA at 100 mg/kg resulted in marked expression of c-Fos, Fra-2 and c-Jun proteins in the granule cell layers of the dentate gyrus in murine hippocampus 2 h later, followed by a significant reduction of the incorporation of 5-bromo-2'-deoxyuridine (BrdU) in a manner sensitive to the antagonist dizocilpine 2 days after administration. The administration of NMDA also suppressed constitutive expression of both nestin and proliferating cell nuclear antigen (PCNA) in the dentate granule cells 2 days later, without markedly affecting cell viability for up to 8 weeks after administration.

Involvement of protein kinase C in glutamate release from cultured microglia.

Glutamate release from microglial cells may cause neuronal damage. To elucidate the mechanism of glutamate release, we examined the possible regulation by nitric oxide and protein kinase C. Cultured microglia prepared from the whole brains of newborn rats released glutamate by the stimulation with lipopolysaccharide (LPS) dose dependently.

Chromosomal region maintenance 1 (CRM1)-dependent nuclear export of Smad ubiquitin regulatory factor 1 (Smurf1) is essential for negative regulation of transforming growth factor-beta signaling by Smad7.

Smad ubiquitin regulatory factor 1 (Smurf1), a HECT type E3 ubiquitin ligase, interacts with inhibitory Smad7 and induces translocation of Smad7 to the cytoplasm. Smurf1 then associates with the transforming growth factor (TGF)-beta type I receptor, TbetaR-I, enhancing turnover. However, the mechanism of nuclear export of Smad7 by Smurf1 has not been elucidated.

Interaction of the chromatin compaction-inducing domain (LR domain) of Ki-67 antigen with HP1 proteins.

Background: The LR domain of marsupial chmadrin is defined by its C-terminal amino acid sequence, which contains several pairs of leucine (L) and arginine (R) residues. The LR domain of chmadrin causes a significant compaction of chromatin over the entire length of chromosomes when it is overproduced. The possible human homologue of chmadrin, Ki-67 antigen (pKi-67), also has a stretch of LR pairs, but with no obvious overall similarity, at its C-terminus.

[Dysphagia due to giant cervical osteophytes].

We reported a patient with isolated dysphagia due to an esophageal canal stenosis compressed by focal cervical spondylotic osteophytes. The patient was a 63-year-old male who developed swallowing disturbance of predominantly solid materials. The neurological examination showed subjectively isolated dysphagia unassociated with any significant cranial nerve signs.

[Dide-Botcazo syndrome associated with Anton's syndrome after a cardioembolic infarction in the distribution of the bilateral posterior cerebral arteries].

Dide-Botcazo syndrome (Rev Neurol, 1902) is a unique neuropsychological syndrome, characterized by combinations of cortical blindness, amnesia, and topographical disorientation. We report 82-year-old right-handed man manifesting such syndrome associated with Anton's syndrome after a cardioembolic infarction in the distribution of the bilateral posterior cerebral arteries. The MRI study demonstrated recent extensive infarctions bilaterally in the occipital lobes and the medial temporal lobes, and thalamus.

Nuclear transcription factors in the hippocampus.

In the mammalian hippocampus, there is a trisynaptic loop that has been often referred to in studies on learning and memory mechanisms and their physiological correlate, the long-term potentiation (LTP). The three sets of synapses are formed by the fibers of perforant pathway terminating on granule cells and by the mossy fibers and Schaeffer collaterals making connections with the pyramidal cells. Each of the three types of synapses can develop LTP.

Importin alpha can migrate into the nucleus in an importin beta- and Ran-independent manner.

A classical nuclear localization signal (NLS)-containing protein is transported into the nucleus via the formation of a NLS-substrate/importin alpha/beta complex. In this study, we found that importin alpha migrated into the nucleus without the addition of importin beta, Ran or any other soluble factors in an in vitro transport assay. A mutant importin alpha lacking the importin beta-binding domain efficiently entered the nucleus.

Alopecia of IFN-gamma knockout mouse as a model for disturbance of the hair cycle: a unique arrest of the hair cycle at the anagen phase accompanied by mitosis.

Interferon-gamma(-/-) (IFN-gamma(-/-)) and IFN-gamma(+/+) C57BL/6 mice (3 weeks of age) completed the production of morphogenesis-derived hair. Around 6 weeks of age, however, most of the IFN-gamma(-/-) but none of the IFN-gamma(+/+) mice began to lose hairs in the dorsal and occipital areas in the absence of inflammatory reactions, and the alopecia was sustained for at least several 10-week periods of observation. A single subcutaneous injection of IFN-gamma to IFN-gamma(-/-) mice at 3, but not 4, 5, or 8 weeks of age could protect all the mice from alopecia, revealing that the lack of IFN-gamma around 3 weeks of age is directly responsible for the alopecia.

Existence of xenobiotic response element binding in Dictyostelium.

Xenobiotic response element (XRE) is a core nucleotide sequence at the upstream of inducible target genes for the transcription factor aryl hydrocarbon receptor (AhR) that is responsible for recognition of exogenous environmental pollutants in eukaryotic cells. Gel retardation electrophoresis revealed the presence of binding of a radiolabeled probe containing XRE in both cytosolic and nuclear preparations of the slime mold Dictyostelium. Unlabeled XRE probe was more potent in competing for XRE binding in both fractions than unlabeled XRE probe with a point mutation at the core element.

The preventive effect of sodium pentosan polysulfate against renal stone formation in hyperoxaluric rats.

Sodium pentosan polysulfate (SPP), a semi-synthetic glycosaminoglycan, was administered to rats with hyperoxaluria, induced by a vitamin B6 deficient diet, as a model of calcium oxalate stone formation. We studied the preventive effects of SPP on stone formation as well as its inhibitory effects on stone growth by autoradiography and radioluminography after intravenous injection of (14)C-oxalate. The rats were divided into non-treated and SPP-treated groups.

Blockade by ferrous iron of Ca2+ influx through N-methyl-D-aspartate receptor channels in immature cultured rat cortical neurons.

Rat cortical neurons cultured for 3 days in vitro were loaded with the fluorescent indicator fluo-3 for assessment of intracellular free calcium ion (Ca2+) concentrations with the aid of a confocal laser-scanning microscope. In the absence of added MgCl2, the addition of NMDA induced a rapid but sustained increase in the number of fluorescent neurons in a concentration-dependent manner at a concentration range of 1-100 micro m with the increase by KCl being transient. The addition of FeCl2, but not FeCl3, markedly inhibited the increase by NMDA in a reversible manner at concentrations of 10-200 micro m, without affecting that by KCl.

Blockade by N-methyl-D-aspartate of elevation of activator protein-1 binding after stress in rat adrenal gland.

Cold immobilization stress induced a marked elevation of expression of activator protein-1 (AP1) complex in rat hypothalamus, pituitary, adrenal, and gastric mucosa, but not in other discrete brain structures examined, when determined immediately after stress for 3 hr. Adrenal AP1 binding linearly increased with the duration of stress up to 6 hr, whereas the increase was seen in both adrenal cortex and medulla of rats stressed for 3 hr. In adrenals, the elevation exhibited decline profiles different from those of expression of cAMP response element binding protein.

Facilitation of glutamate release by ionotropic glutamate receptors in osteoblasts.

Constitutive expression of mRNA was seen for the vesicular glutamate transporter brain-specific Na(+)-dependent inorganic phosphate cotransporter (BNPI), but not differentiation-associated Na(+)-dependent inorganic phosphate cotransporter, in rat calvarial osteoblasts cultured for 7 and 21 days in vitro (DIV). Three different agonists for ionotropic glutamate receptors (iGluR) at 1mM, as well as 50mM KCl, significantly increased the release of endogenous L-glutamate from osteoblasts cultured for 7DIV when determined 5 min after the addition by using a high performance liquid chromatograph. The inhibitor of desensitization of DL-alpha-amino-3-hydroxy-5-methylisoxasole-4-propionate (AMPA) receptors cyclothiazide significantly potentiated and prolonged the release of endogenous L-glutamate evoked by AMPA in a dose-dependent manner.

Transcription factors and drugs in the brain.

In mammalian cells, protein de novo synthesis is mainly regulated at the stage of gene transcription by RNA polymerase II in the nucleus. Transcription factors are proteins that bind to the specific nucleotide sequences at promoter or enhancer regions on target genes to control the transcription of mRNA from genomic DNA. In this article, we have outlined the signal responsiveness of different transcription factors to particular drugs in the brain.

Identification of Ewing's sarcoma gene product as a glycoprotein using a monoclonal antibody that recognizes an immunodeterminant containing O-linked N-acetylglucosamine moiety.

The Ewing's sarcoma (EWS) oncogene is fused to a variety of cellular transcription factors in various forms of human cancers. Although EWS fusion proteins have been extensively studied, the normal function of EWS remains poorly characterized. We previously reported that a monoclonal antibody, referred to as MY95, recognized nucleoporins such as p62, Nup98, and CAN/Nup214 and an uncharacterized polypeptide with an apparent molecular mass of 83 kDa.

Activation of mitochondrial voltage-dependent anion channel by apro-apoptotic BH3-only protein Bim.

Bcl-2 family of proteins regulates apoptosis by controlling mitochondrial membrane permeability. We have previously shown that the voltage-dependent anion channel (VDAC) plays a crucial role in apoptotic changes of the mitochondria and its activity is directly regulated by some Bcl-2 family members, including Bcl-2/Bcl-x(L) and Bax/Bak but not Bid. Here, we showed that in isolated mitochondria, Bim induced loss of membrane potential and cytochrome c release like Bax/Bak, with these changes being inhibited by an anti-VDAC antibody.

In vitro and in vivo antagonistic activities of SM-31900 for the NMDA receptor glycine-binding site.

The purpose of this study was to clarify the in vitro pharmacological profile and the in vivo activity of (3S)-7-chloro-3-[2-((1R)-1-carboxyethoxy)-4-aminomethylphenyl]aminocarbonylmethyl-1,3,4,5-tetrahydrobenz[c,d]indole-2-carboxylic acid hydrochloride (SM-31900). SM-31900 inhibited the binding of [3H]glycine and [3H]5,7-dichlorokynurenic acid, radioligands for the N-methyl-D-aspartate (NMDA) receptor glycine-binding site, to rat brain membranes in a competitive manner, with K(i) values of 11+/-2 and 1.0+/-0.

Demonstration of expression of mRNA for particular AMPA and kainate receptor subunits in immature and mature cultured rat calvarial osteoblasts.

Reverse transcription polymerase chain reaction revealed expression of mRNA for particular subunits of ionotropic glutamate receptors (iGluR) in primary cultures of rat calvarial osteoblastic cells under immature to mature states. These included GluR3, KA1 and KA2 subunits, in addition to NR1 and NR2D subunits. These results suggest that glutamate may play an unidentified role in mechanisms associated with cellular development through particular subunits of iGluR in rat calvarial osteoblasts.

[Sequential magnetic resonance imaging and neurophysiological studies in a patient with inferior spinal cord infarction].

A 66-year-old woman suddenly developed anterior spinal artery syndrome with complete flaccid paraplegia, superficial sensory disturbance caudally to the L5 dermatome level with preservation of deep sensation, incontinence, and absent deep tendon reflexes in both legs. An MRI of the whole spine and an analysis of the CSF 4 hours after onset were normal. The electrophysiological study showed an absence of F wave on the posterior tibial nerve stimulation on admission, while the peripheral nerve conduction velocities and amplitudes of upper and lower limbs were normal.

Cell death by pyruvate deficiency in proliferative cultured calvarial osteoblasts.

Cell survival was significantly decreased in primary cultured rat calvarial osteoblasts in vitro at Day 0, 1, and 3 by replacement of the standard culture medium (alpha-modified minimum essential medium; alpha-MEM) with Dulbecco's modified eagle's medium (DMEM). Decreased cell survival was also observed following medium replacement in cultures of murine calvaria-derived osteoblastic cell line MC3T3-E1. Staining with Hoechst33342 revealed apoptotic cells with fragmented or condensed nuclei, while a fraction of the cell culture was stained with propidum iodide, indicating necrosis.

Molecular cloning of one isotype of human lamina-associated polypeptide 1s and a topological analysis using its deletion mutants.

LAP1s (lamina-associated polypeptide 1s) are type 2 integral membrane proteins with a single membrane-spanning region of the inner nuclear membrane. We report here on the cloning of the full-length cDNA of human LAP1B (huLAP1B) that encodes 584 amino acids. The sequence homology between the predicted rat LAP1B and huLAP1B was found to be 73.

Functional GABA(B) receptors expressed in cultured calvarial osteoblasts.

In immature and mature primary cultured rat calvarial osteoblasts, both mRNA and corresponding proteins were constitutively expressed for 2 splice variants of GABA(B) receptor (GABA(B)R) subunits but not for any known GABA(A) and GABA(C) receptor subunits. The agonist for GABA(B)R baclofen significantly inhibited cAMP formation induced by forskolin in a manner sensitive to the antagonist 2-hydroxysaclofen. Similar expression was seen with mRNA for GABA(B)R-1a and -1b splice variants in the murine calvarial osteoblast cell line MC3TC-E1 cells cultured for 7-21 days in vitro (DIV).