VEGF-dependent continuous angiogenesis in the median eminence of adult mice.

Brain vasculature forms the blood-brain barrier (BBB) that restricts the movement of molecules between the brain and blood, but the capillary of the median eminence (ME) lacks the BBB for secretion of adenohypophysial hormone-releasing peptides. In the present study, we aimed to elucidate whether continuous angiogenesis occurs in the ME of adult mice. By using a mitotic marker, bromodeoxyuridine (BrdU), we demonstrated that new endothelial cells were born continuously in the ME of adults. Prominent expression of NG2, platelet-derived growth factor receptor B (PDGFRB), and delta-like ligand 4 was observed at pericytes of adults, although the expression of these angiogenesis-associated proteins has been shown to be at low or trace levels in adult mature capillary. In addition, vascular endothelial growth factor (VEGF), a key regulator of angiogenesis, was expressed highly in the nervous parenchyma of the ME. Expression of VEGF receptor 2 (VEGFR2) was observed at endothelial cells in the external zone and at somatodendrites in the internal zone. Finally, a VEGFR- and PDGFR-associated tyrosine kinase inhibitor, SU11248, significantly decreased the number of BrdU-positive proliferating endothelial cells and parenchyma cells. In conclusion, the present study demonstrates VEGF-dependent continuous angiogenesis in the ME of adult mouse brains under normal conditions, which provides new insight into our understanding of neurosecretion in the ME.

Metabolic Syndrome and Cognitive Function: Cross-Sectional Study on Community-Dwelling Non-Demented Older Adults in Japan.

AIM: This is a cross-sectional study of relation between metabolic syndrome and cognitive function in community-dwelling non-demented older adults in Japan. We examine the effect of metabolic syndrome and its components on global cognitive function. We also aim to clarify differences of specific cognitive domains between the subjects with and without metabolic syndrome. METHODS: We studied 2150 subjects aged between 60 and 90 years whose scores on mini mental state examination (MMSE) were over 23 points. We analyzed difference in MMSE scores between the subjects with and without metabolic syndrome. Logistic regression analysis was performed with MMSE score as the dependent variable and metabolic syndrome components as the independent variable adjusted with age. We also examined differences in attention, logical memory, and verbal and category fluency between the subjects with and without metabolic syndrome. RESULTS: MMSE scores were not significantly different between subjects with and without metabolic syndrome. In logistic regression analysis, the score of MMSE was significantly negatively associated with triglycerides in males and significantly negatively associated with abdominal circumference in females. Subjects with metabolic syndrome showed significantly lower performance of attention tasks compared to subjects without metabolic syndrome. CONCLUSIONS: Our results suggest that in community-dwelling non-demented Japanese older adults, attention but not global cognitive function may be impaired by metabolic syndrome. Inverted association between some components of metabolic syndrome and global cognitive function indicate necessity of further studies on the relation between undernutrition and cognitive function.

Medial prefrontal cortex generates frontal midline theta rhythm.

Frontal midline theta rhythm (Fm theta) is a distinct theta activity of EEG in the frontal midline area that appears during concentrated performance of mental tasks in normal subjects and reflects focused attentional processing. To tomographically visualize the source current density distributions of Fm theta, we recorded Fm theta by using a 64-channel whole-head MEG system from four healthy subjects, and applied a new analysis method, synthetic aperture magnetometry (SAM), an adaptive beam forming method. Fm theta was observed in the MEG signals over the bilateral frontal regions. SAM analysis showed bilateral medial prefrontal cortices, including anterior cingulate cortex, as the source of Fm theta. This result suggests that focused attention is mainly related to medial prefrontal cortex.

Theta rhythm increases in left superior temporal cortex during auditory hallucinations in schizophrenia: a case report.

Auditory hallucinations (AH), the perception of sounds and voices in the absence of external stimuli, remain a serious problem for a large subgroup of patients with schizophrenia. Functional imaging of brain activity associated with AH is difficult, since the target event is involuntary and its timing cannot be predicted. Prior efforts to image the patterns of cortical activity during AH have yielded conflicting results. In this study, MEG was used to directly image the brain electrophysiological events associated with AH in schizophrenia. We observed an increase in theta rhythm, as sporadic bursts, in the left superior temporal area during the AH states, whereas there was steady theta band activity in the resting state. The present finding suggests strong association of the left superior temporal cortex with the experience of AH in this patient. This is consistent with the hypothesis that AH arises from areas of auditory cortex subserving receptive language processing.

Changes in the fractal dimension of alpha envelope from wakefulness to drowsiness in the human electroencephalogram.

Changes in the fractal dimension of the waxing and waning of alpha activity from wakefulness to drowsiness were investigated in 10 normal subjects. The envelope of filtered alpha activity was estimated with the Hilbert transform. A subset time series was constructed from the alpha envelope data taken at an interval (k). The points of the logarithm of interval k vs. the logarithm of the curve length of the subset time series (log L(k)) were fitted by a two-segment curve, consisting of small and long line segments (segments 1 and 2). The fractal dimension was estimated from the slope of straight line for each segment by using Higuchi's method. The mean fractal dimension was 1.16 for segment 1 and 1.95 for segment 2 during wakefulness and 1.15 for segment 1 and 1.89 for segment 2 during drowsiness. The fractal dimension significantly decreased in both segments during drowsiness, thus, indicating decreases in the complexity of alpha envelope.

Dimethyl sulfoxide (DMSO) blocks GABA-induced current in rat dorsal root ganglion neurons.

The effects of dimethyl sulfoxide (DMSO) on gamma-aminobutyric acid (GABA)-induced Cl- currents of rat dorsal root ganglion neurons in primary culture were studied by the whole-cell patch-clamp technique. Bath application of 5 microM GABA evoked sustained inward and outward currents at membrane potentials of -60 mV and +30 mV, respectively, when the external and internal solutions both contained 142 mM Cl-. DMSO at concentrations of 0.3-3% (v/v) caused a dose-dependent inhibition of the inward current induced by 5 microM GABA at -60 mV. DMSO at 3% inhibited the GABA-induced inward and outward currents at -60 mV and +30 mV to similar extents (54% and 53% of the control, respectively), but the time-course of inhibition of the outward current at +30 mV was much faster than that of the inward current at -60 mV. These results suggest that DMSO suppressed the currents by interacting with GABA receptor-Cl- channel complex protein rather than by affecting the lipid-bilayer of the cell membrane.

Structural features and hypoglycemic activities of two polysaccharides from a hot-water extract of Agrocybe cylindracea.

A glucan (AG-HN1, [alpha]D +24 degrees) and a heteroglycan (AG-HN2, [alpha]D +26 degrees) were isolated from a hot-water extract of the fruiting bodies of Agrocybe cylindracea. The structures were investigated by a combination of chemical and spectroscopic methods. The results indicated that high molecular weight glucan AG-HN1 is primarily a beta-(1-->6)-branched (1-->3)-beta-D-glucan containing small amounts of (1-->4)-linked and (1-->6)-linked glucopyranosyl residues. Low molecular weight heteroglycan AG-HN2 gives galactose, glucose, fucose, and mannose on hydrolysis and appears to be chiefly composed of (1-->6)-linked gluco- and galacto-pyranosyl residues, many of them branched, and various nonreducing terminal residues. AG-HN1 showed a remarkable hypoglycemic activity in both normal and streptozotocin-induced diabetic mice by ip administration, and its activity was higher than that of AG-HN2.

Anti-inflammatory activity and conformational behavior of a branched (1 leads to 3)-beta-D-glucan from an alkaline extract of Dictyophora indusiata Fisch.

A (1 leads to 6)-branched (1 leads to 3)-beta-D-glucan (T-5-N), isolated from a M sodium hydroxide extract of the fruit bodies of Dictyophora indusita Fisch., markedly exhibited anti-inflammatory effects on both carrageenan-induced edema and scalded edematous hyperalgesia in rat's hindpaws. The activities of T-5-N (25 mg/kg i.p. X 2) were more potent than those of phenylbutazone (25-50 mg/kg i.p. X 2). The conformational behavior of T-5-N was studied. Its molecular weight in neutral solution was about three times that in 0.25M sodium hydroxide. This finding, in addition to the results of optical rotatory measurement and complex-formation with Congo Red, indicated that T-5-N has an ordered, triple-helical structure in neutral or slightly alkaline solution (less than 0.15M NaOH), and has single chains in highly alkaline solution (greater than 0.25M NaOH). The conformational transition occurs at concentrations of sodium hydroxide in the range of 0.15-0.25M.

(1----3)-alpha-D-glucan from an alkaline extract of Agrocybe cylindracea, and antitumor activity of its O-(carboxymethyl)ated derivatives.

The structure of an alkali-soluble D-glucan (AG-AL) from the fruit body of Agrocybe cylindracea was investigated by a combination of chemical and spectroscopic methods indicating that it was a linear (1----3)-alpha-D-glucan (molecular weight, approximately 560,000), [alpha]20D +195 degrees (c 0.5, M sodium hydroxide). Both water-soluble and gelatinous products obtained by O-(carboxymethyl)ation of AG-AL showed potent antitumor activity against the solid form of Sarcoma 180 in mice, although the native D-glucan had little effect on the tumor.

Structure and antitumor activity of a branched (1----3)-beta-D-glucan from the alkaline extract of Amanita muscaria.

A beta-(1----6)-branched (1----3)-beta-D-glucan(AM-ASN) was isolated from the alkaline extract of the fruiting bodies of Amanita muscaria. AM-ASN had [alpha]D - 11 degrees in 0.5 M sodium hydroxide. Its estimated molecular weight was 95,000 in this alkaline solution and 260,000 in a neutral solution. The branches in the glucan were primarily single, (1----6)-linked D-glucopyranosyl groups, two for every seven residues in the (1----3)-linked main chain. AM-ASN exhibited significant antitumor activity against Sarcoma 180 in mice, and a mixture of AM-ASN with mitomycin C was more effective against the tumor than mitomycin C only.

Spindle activity in the waking EEG in older adults.

Sleep spindles are an EEG sign of light sleep under physiological conditions. We reported the simultaneous occurrence of sleep spindles and alpha activity in the waking EEG in 12 patients with a mean age of 59.0 years. Most of the patients were diagnosed as cerebrovascular disorders such as cerebral arteriosclerosis, transient ischemic attack and vascular dementia. The mean alpha frequency in the presence of WSA significantly decreased by 1.5 Hz. The frequency and spatial distribution of waking spindle activity were similar to those of sleep spindles. In our cases, at least the two factors of cerebrovascular involvement and older adults were considered to be primarily responsible for the intrusion of sleep spindles into wakefulness (presumably a state close to very light drowsiness) due possibly to the instability of sleep-waking cycle regulation.

Analysis of wool fiber by alkali-catalyzed pyrolysis gas chromatography.

Alkali-catalyzed pyrolysis gas chromatography (PyGC) has been used to identify minute samples of wool fiber. The wool sample to which aqueous sodium hydroxide was added was pyrolyzed in a Curie-point pyrolyzer attached to a gas chromatograph or a gas chromatograph-mass spectrometer. The addition of an aqueous solution of sodium hydroxide increased the production of specific volatile pyrolysis products from the constitutive amino acid residues of wool protein, i.e. acetaldehyde from alanine or proline, isobutyronitrile from valine, 2-methylbutyronitrile from isoleucine, isovaleronitrile from leucine and toluene from phenylalanine. Compared with conventional non-catalyzed PyGC, the alkali-catalyzed PyGC was found to greatly improve the detection limit of wool fiber and make it possible to analyze very minute samples. The alkali-catalyzed PyGC presented here has been shown to be applicable to minute thermally-denatured samples of wool fiber which cannot be identified successfully by morphological inspection using a microscope or by using Fourier-transform infrared microspectroscopy. Furthermore, the present PyGC method was successfully used for several protein samples and was shown to be useful for analysis of proteins other than wool fibers by using different special pyrograms reflecting different amino acid compositions.

[Synthesis and antitumor activities of conjugates of mitomycin C-polysaccharide from Tremella fuciformis].

The conjugates of mitomycin C (MMC) with glucuronoxylomannan (AC) from Tremella fuciformis were synthesized by the use of spacers (glycine, glycylglycine, glycylglycylglycine). In i.p.-i.p. system the antitumor activity of the conjugates (MMC-G-ACP, MMC-GG-ACP, MMC-GGG-ACP) against P388 leukemia in mice was slightly lower than that of MMC by the evaluation of life span, ILS (%). In s.c.-i.p. system the antitumor activity of the conjugates against sarcoma 180 solid tumor in mice was similar to that of MMC, except for MMC-G-ACP. The reduction of the number of leukocytes caused by MMC was suppressed by attaching MMC to AC. The conjugates did not lower the cytotoxicity of MMC against L1210 mouse leukemia cells in vitro. The release rate of MMC from the conjugates in vitro (half time of MMC release: MMC-G-ACP, 8.8 h; MMC-GG-ACP, 3.1 h; MMC-GGG-ACP, 2.9 h) was much faster than that of MMC-dextran, and differed in the length of the spacer. The results would give useful information on macromolecular carriers in drug-delivery system.

[Hypoglycemic activity of polysaccharide fraction from rhizome of Rehmannia glutinosa Libosch. f. hueichingensis Hsiao and the effect on carbohydrate metabolism in normal mouse liver].

The ethanol precipitate fraction (RG-WP) obtained from the hot water extract from rhizome of Rehmannia glutinosa Libosch. f. hueichingensis Hsiao is mainly composed of pectin-like polysaccharide, and exhibited hypoglycemic activity in normal and streptozotocin-induced mice by intraperitoneal administration of the fraction. The results obtained after chemical modification and proteinase treatments of RG-WP suggest that the activity exists in the polysaccharide moiety. Furthermore, the effect of RG-WP on the activities of enzymes responsible for the glucose metabolism in the liver of normal mouse was studied to elucidate the mechanism of the hypoglycemic activity. Administration of RG-WP to normal mice significantly increased the activities of hepatic glucokinase and glucose-6-phosphatase dehydrogenase, but decreased those of hepatic glucose-6-phosphatase and phosphofructokinase. RG-WP stimulated the secretion of insulin and reduced the glycogen content in the liver of normal mouse.

[Polysaccharides in fungi. XXXIII. Hypoglycemic activity of an acidic polysaccharide (AC) from Tremella fuciformis].

Glucuronoxylomannan (AC) from the fruiting bodies of Tremella fuciformis exhibited a significant dose-dependent hypoglycemic activity in normal mice and also showed a significant activity in streptozotocin-induced diabetic mice, by intraperitoneal (i.p.) administration. The activities of AC-derivatives such as a product of AC which side chains had been removed were lower than that of native AC. AC raised the plasma insulin level in normal mice. Administration of AC to normal mice significantly increased the activities of hepatic hexokinase and glucose-6-phosphatase dehydrogenase, but it decreased that of hepatic glucose-6-phosphatase. Furthermore, AC reduced the glycogen content in the liver, increased the total lipid in epididymal adipose tissue, and lowered the plasma cholesterol level. The foregoing results indicated that the hypoglycemic activity of AC in normal mice was at least responsible for the increase of insulin secretion and for the acceleration of glucose metabolism. Single oral administration at a dose of 50-300 mg/kg of AC did not affect the plasma glucose level in normal mice, but continuous oral administrations of the AC solution (0.75 g/l) instead of water for a long time was found to be effective on the plasma glucose level in both experiments of the mice injected once i.p. with streptozotocin (170 mg/kg) at 0 d of AC administration and streptozotocin-induced diabetic mice.

[Polysaccharides in fungi. XXV. Biological activities of two galactomannans from the insect-body portion of Chán hua (fungus: Cordyceps cicadae)].

Biological activities of two galactomannans (CI-P and CI-A) isolated from the insectbody portion of Chán hua (fungus: Cordyceps cicadae) were studied. CI-P having low affinity for concanavalin A (Con A) exhibited potent carbon-clearance activity in mouse, although both polysaccharides had little antitumor activity against sarcoma 180 in mice. Furthermore, CI-P and CI-A was found to have potent hypoglycemic activity in normal mice, and CI-A having high affinity for Con A showed slightly higher activity than CI-P.

[Gas chromatographic analysis of reduction products of paraquat, diquat and the related compounds: reductive cleavage in the pyridine ring on N-alkylpyridinium derivatives with NaBH4-NiCl2 reduction system, and inhibition of the cleavage].

When N-alkylpyridinium derivatives were reduced with sodium borohydride-nickel (II) chloride reduction system, reductive cleavage occurred at the C-N bond in the pyridine ring of N-alkylpyridinium derivatives to give a small amount of reductive cleavage product along with the major perhydrogenated product. It was presumed in the previous report that this reductive cleavage in the pyridine ring proceeded through a complex of nickel ion and 1,2,3,6-tetrahydropyridine derivatives produced with NaBH4 alone reduction. The abundances of these reductive cleavage products arising from N-alkylpyridinium derivatives, i.e., paraquat, diquat and so on, are capable of giving a bad effect on the accuracy of gas chromatographic analysis. For the purpose of inhibition of the reductive cleavage in this reduction system, a suitable catalyst was examined. In addition, we pursued whether borane-1,2,3,6-tetrahydropyridine derivative complexes arose from N-alkylpyridinium derivatives by NaBH4 alone reduction or not, and whether these borane-amine complexes were the precursors of reductive cleavage products or not. N-Alkyl-1,2,3,6-tetrahydropyridine derivatives (III-I, IV-I, VI-I, VII-I and VIII-I) and the corresponding borane-amine complexes (III-II, IV-II, VI-II, VII-II and VIII-II) were synthesized by NaBH4 reduction in aqueous solution of N-alkylpyridinium salts, i.e. I, II, 1,4-dimethylpyridinium iodide (III), 1-dodecylpyridinium chloride (IV), 1,1'-diethyl-4,4'-dipyridinium dichloride (V), 1-methyl-4-phenylpyridinium iodide (VI), 1-n-propylpyridinium iodide (VII) and 1-n-butylpyridinium iodide (VIII). The structure of the borane-amine complexes were proved by the Mass spectrometry and 1H- and 13C-NMR analysis. The NiCl2-NaBH4 reduction of the borane-amine complexes gave the perhydrogenated products alone, but not reductive cleavage products. In conclusion, it was recognized that the precursors of reductive cleavage products were not borane-amine complexes, but 1,2,3,6-tetrahydropyridine. Furthermore, it was found the reductive cleavage at the C-N bond in the pyridine ring of these 1,2,3,6-tetrahydropyridine derivatives was hindered by applying Amberlite-Ni2B, NaBH4 reduction system.

SAM(g2) analysis for detecting spike localization: a comparison with clinical symptoms and ECD analysis in an epileptic patient.

SAM(g2) analysis, a combination of synthetic aperture magnetometry (SAM) and excess kurtosis (g2) method, is a novel epilepsy analysis procedure based on a spatial filtering technique. By producing a three-dimensional image of the g2 values and superimposing them onto a patient's MR images, this analysis can automatically estimate spike localization from raw MEG epilepsy signals including spikes. The aim of this study is to examine SAM(g2) analysis using MEG signals of an epileptic patient, whose clinical symptoms of colored elementary visual auras had ceased in accordance with the changes of the estimated localizations of the equivalent current dipoles (ECDs) of the interictal spikes. His visual auras were experienced in 1997, while they ceased in 1999 with effective medication. The patient provided written informed consent for the experimental procedures. The MEG signals were recorded in 1997 and 1999, and were analyzed using both ECD and SAM(g2) analyses. For the MEG signals of 1997, ECD analysis estimated most of the interictal spikes in the right fusiform and inferior temporal gyri, which subserve human color processing. SAM(g2) analysis also estimated them in the same areas. For those of 1999, both ECD and SAM(g2) analyses estimated them in the right transverse gyrus of Heschl. As well as ECD analysis, SAM(g2) analysis successfully estimated the changes of the localizations of the interictal spikes in accordance with the changes of the patient's clinical symptoms, indicating that SAM(g2) analysis is useful for detection of interictal spike localization in epileptic patients.

Three-dimensional characterization of ODS ferritic steel using by FIB-SEM serial sectioning method.

Considerable attention has been paid to the research of the electron tomography due to determine the three-dimensional (3D) structure of materials [1]. One of the electron tomography techniques, focused ion beam/scanning electron microscopy (FIB-SEM) imaging has advantages of high resolutions (10 nm), large area observation (µm order) and simultaneous energy dispersive x- ray microanalysis (EDS)/ electron backscatter diffraction (EBSD) analysis. The purpose of this study, three-dimensional EBSD analysis of ODS ferritic steel which carried out cold work using FIB-SEM equipment was conducted, and it aimed at analyzing the microstructure obtained there. The zone annealing tests were conducted for ferritic steel [2,3], which were produced through mechanical alloying and hot-extrusion. After zone annealing, specimens were mechanically polished with #400∼4000 emery paper, 1 µm diamond paste and alumina colloidal silica. The serial sectioning and the 3D-electron backscattering diffraction (3D-EBSD) analysis were carried out. We made the micro pillar (30 x 30 x 15 µm). The EBSD measurements were carried out in each layer after serial sectioning at a step size and milling depth was 80 nm with 30 slices. After EBSD analysis, the series of cross-sectional images were aligned according to arbitrarily specified areas and then stacked up to form a volume. Consequently, we obtained the 3D-IPF maps for ODS ferritic steel. In this specimen, the {111} and {001} grains are layered by turns. In addition, the volume fraction value of both plane are similar. The aspect ratio increases with specimen depth. The 3D-EBSD mapping is useful to analysis of the bulk material since this method obtain many microstructure information, such a shape, volume and orientation of the crystal, grain boundary.