Effective method of monitoring cerebral tissue oxygen saturation in cardiac surgery patients by combined use of tNIRS-1 and bispectral index.

To continuously and noninvasively monitor the cerebral tissue oxygen saturation (StO2) and hemoglobin concentration (gasHb) in cardiac surgery patients, a method combining the use of a cerebral tissue oximeter using near infrared time-resolved spectroscopy (tNIRS-1) and the bispectral index (BIS) was developed in this study. Moreover, the correlation between the estimated hemoglobin concentration (estHb), measured via tNIRS-1, and the hemoglobin concentration (gasHb), analyzed using a blood gas analyzer, were compared. The relationship between the BIS and gasHb was also examined. Through the comparison of BIS and StO2 (r1), and estHb and gasHb (r2), the correlation between the two was clarified with maximum r1 and r2 values of 0.617 and 0.946, respectively. The relationship between BIS and gasHb (r3), showed that there was a favorable correlation with a maximum r3 value of 0.969. There was also a continuous correlation between BIS and StO2 in patients undergoing cardiac surgery. In addition, a strong correlation was found between estHb and gasHb, and between BIS and gasHb. It was therefore concluded that the combined use of BIS and tNIRS-1 is useful to evaluate cerebral hypoxia, allowing for quick response to cerebral hypoxia and reduction of hemoglobin concentration during the operation.

Phenotypic differences in hiPSC NPCs derived from patients with schizophrenia.

Consistent with recent reports indicating that neurons differentiated in vitro from human-induced pluripotent stem cells (hiPSCs) are immature relative to those in the human brain, gene expression comparisons of our hiPSC-derived neurons to the Allen BrainSpan Atlas indicate that they most resemble fetal brain tissue. This finding suggests that, rather than modeling the late features of schizophrenia (SZ), hiPSC-based models may be better suited for the study of disease predisposition. We now report that a significant fraction of the gene signature of SZ hiPSC-derived neurons is conserved in SZ hiPSC neural progenitor cells (NPCs). We used two independent discovery-based approaches-microarray gene expression and stable isotope labeling by amino acids in cell culture (SILAC) quantitative proteomic mass spectrometry analyses-to identify cellular phenotypes in SZ hiPSC NPCs from four SZ patients. From our findings that SZ hiPSC NPCs show abnormal gene expression and protein levels related to cytoskeletal remodeling and oxidative stress, we predicted, and subsequently observed, aberrant migration and increased oxidative stress in SZ hiPSC NPCs. These reproducible NPC phenotypes were identified through scalable assays that can be applied to expanded cohorts of SZ patients, making them a potentially valuable tool with which to study the developmental mechanisms contributing to SZ.

Brain amino acid sensing.

The 20 different amino acids, in blood as well as in the brain, are strictly maintained at the same levels throughout the day, regardless of food intake. Gastric vagal afferents only respond to free glutamate and sugars, providing recognition of food intake and initiating digestion. Metabolic control of amino acid homeostasis and diet-induced thermogenesis is triggered by this glutamate signalling in the stomach through the gut-brain axis. Rats chronically fed high-sugar and high-fat diets do not develop obesity when a 1% (w/v) monosodium glutamate (MSG) solution is available in a choice paradigm. Deficiency of the essential amino acid lysine (Lys) induced a plasticity in rats in response to Lys. This result shows how the body is able to identify deficient nutrients to maintain homeostasis. This plastic effect is induced by activin A activity in the brain, particularly in certain neurons in the lateral hypothalamic area (LHA) which is the centre for amino acid homeostasis and appetite. These neurons respond to glutamate signalling in the oral cavity by which umami taste is perceived. They play a quantitative role in regulating ingestion of deficient nutrients, thereby leading to a healthier life. After recovery from malnutrition, rats prefer MSG solutions, which serve as biomarkers for protein nutrition.

Digestive physiology of the pig symposium: detection of dietary glutamate via gut-brain axis.

Gustatory and visceral stimulation from food regulates digestion and nutrient use. Free L-glutamate (Glu) release from digested protein is responsible for umami taste perception in the gut. Moreover, monosodium Glu (MSG) is widely used as a flavor enhancer to add umami taste in various cuisines. Recent studies indicate that dietary Glu sensors and their signal transduction system exist in both gut mucosa and taste cells. Oral Glu sensing has been well studied. In this review, we focus on the role of Glu on digestion and absorption of food. Infusion of Glu into the stomach and intestine increase afferent nerve activity of the gastric and the celiac branches of the vagus nerve, respectively. Luminal Glu also evokes efferent nerve activation of the abdominal vagus nerve branches simultaneously. Additionally, intragastric infusion of Glu activates the insular cortex, limbic system, hypothalamus, nucleus tractus solitaries, and amygdala, as determined by functional magnetic resonance imaging, and is able to induce flavor-preference learning as a result of postingestive effects in rats. These results indicate that Glu signaling via gustatory and visceral pathways plays an important role in the processes of digestion, absorption, metabolism, and other physiological functions via activation of the brain.

Detecting sweet and umami tastes in the gastrointestinal tract.

Information about nutrients is a critical part of food selection in living creatures. Each animal species has developed its own way to safely seek and obtain the foods necessary for them to survive and propagate. Necessarily, humans and other vertebrates have developed special chemosensory organs such as taste and olfactory organs. Much attention, recently, has been given to the gastrointestinal (GI) tract as another chemosensory organ. Although the GI tract had been considered to be solely for digestion and absorption of foods and nutrients, researchers have recently found taste-signalling elements, including receptors, in this tissue. Further studies have revealed that taste cells in the oral cavity and taste-like cells in the GI tract appear to share common characteristics. Major receptors to detect umami, sweet and bitter are found in the GI tract, and it is now proposed that taste-like cells reside in the GI tract to sense nutrients and help maintain homeostasis. In this review, we summarize recent findings of chemoreception especially through sweet and umami sensors in the GI tract. In addition, the possibility of purinergic transmission from taste-like cells in the GI tract to vagus nerves is discussed.

A tale of two systems: peptide ligand-receptor pairs in plant development.

Plants have developed intercellular signaling systems that use secreted peptides and plasma membrane-localized receptor-like kinases (RLKs). Although there has been little experimental evidence linking specific peptide ligands to receptors, recent studies of several ligand-receptor pairs have revealed their increasingly important roles in cell-cell communications during plant development. In this review, we focus on two specific families of plant peptides: the CLAVATA3/ENDOSPERM SURROUNDING REGION (CLE) peptide family and the EPIDERMAL PATTERING FACTOR (EPF) family, along with their corresponding RLKs. We discuss how these two unrelated peptide-mediated signaling systems control plant cell fate and development using similar receptor kinases as well as the mechanisms for how these peptide ligand-receptor pairs precisely regulate various distinct aspects of plant development at the level of ligand-receptor recognition and signal transduction.

Induction of Fos expression in the rat forebrain after intragastric administration of monosodium L-glutamate, glucose and NaCl.

l-glutamate, an umami taste substance, is a key molecule coupled to a food intake signaling pathway. Furthermore, recent studies have unveiled new roles for dietary glutamate on gut-brain axis communication via activation of gut glutamate receptors and subsequent vagus nerve. In the present study, we mapped activation sites of the rat forebrain after intragastric load of 60 mM monosodium l-glutamate (MSG) by measurement of Fos protein, a functional marker of neuronal activation. The same concentration of d-glucose (sweet) and NaCl (salty) was used as controls. MSG administration exclusively produced enhanced Fos expression in four hypothalamic regions (the medial preoptic area, lateral hypothalamic area, dorsomedial nucleus, and arcuate nucleus). On the other hand, glucose administration exclusively enhanced Fos induction in the nucleus accumbens. Both MSG and glucose enhanced Fos induction in three brain regions (the habenular nucleus, paraventricular nucleus, and central nucleus of the amygdala). However, MSG induced Fos inductions were more potent than those of glucose in the habenular nucleus and paraventricular nucleus. Importantly, the present study identified for the first time two brain areas (the paraventricular and arcuate hypothalamic nuclei) that are more potently activated by intragastric MSG loads compared with glucose and NaCl. Overall, our results suggest significant activation of a neural network comprising the habenular nucleus, amygdala, and the hypothalamic subnuclei following intragastric load with glutamate.

The role of the GABAergic and dopaminergic systems in the brain response to an intragastric load of alcohol in conscious rats.

The brain's response to ethanol intake has been extensively investigated using electrophysiological recordings, brain lesion techniques, and c-Fos immunoreactivity. However, few studies have investigated this phenomenon using functional magnetic resonance imaging (fMRI). In the present study, we used fMRI to investigate the blood oxygenation level-dependent (BOLD) signal response to an intragastric (IG) load of ethanol in conscious, ethanol-naive rats. An intragastrically infused 10% ethanol solution induced a significant decrease in the intensity of the BOLD signal in several regions of the brain, including the bilateral amygdala (AMG), nucleus accumbens (NAc), hippocampus, ventral pallidum, insular cortex, and cingulate cortex, and an increase in the BOLD signal in the ventral tegmental area (VTA) and hypothalamic regions. Treatment with bicuculline, which is an antagonist of the gamma-aminobutyric acid A (GABA(A)) receptor, increased the BOLD signal intensity in the regions that had shown decreases in the BOLD signal after the IG infusion of 10% ethanol solution, but it did not affect the BOLD signal increase in the hypothalamus. Treatment with SCH39166, which is an antagonist of D1-like receptors, eliminated the increase in the BOLD signal intensity in the hypothalamic areas but did not affect the BOLD signal decrease following the 10% ethanol infusion. These results indicate that an IG load of ethanol caused both a GABA(A) receptor-mediated BOLD decrease in the limbic system and the cortex and a D1-like receptor-mediated BOLD increase in the hypothalamic regions in ethanol-naive rats.

Effects of isoflurane and alpha-chloralose anesthesia on BOLD fMRI responses to ingested L-glutamate in rats.

It is important to investigate the effect of anesthesia on blood oxygenation level-dependent (BOLD) signals in an animal model. Many researchers have investigated the BOLD response to visual, sensory, and chemical stimuli in anesthetized rats. There are no reports, however, comparing the differences in the BOLD signal change between anesthetized and conscious rats when a visceral nutrient signal arises. Here, using functional magnetic resonance imaging (fMRI), we investigated the differences in the BOLD signal changes after intragastric administration of l-glutamate (Glu) under three anesthesia conditions: conscious, alpha-chloralose-anesthetized, and isoflurane-anesthetized condition. Under the conscious and alpha-chloralose condition, we observed the significant BOLD signal increase in the medial prefrontal cortex (mPFC), insular cortex (IC), hippocampus, and several hypothalamic regions including the lateral and ventromedial nucleus. In chloralose group, however, gut Glu stimulation induced BOLD signal increase in the prelimbic cortex and orbital cortex, which did not activate in conscious condition. Meanwhile, under isoflurane-anesthetized condition, we did not observe the BOLD signal increase in these areas. BOLD signal intensity in the nucleus of the solitary tract (NTS), to which vagus nerve transmits the visceral information from the gastrointestinal tract, increased in all conditions. Importantly, under conscious condition, we observed increased BOLD signal intensity in several regions related to the metabolic state (i.e. hunger or satiety), such as the mPFC, ventromedial and lateral hypothalamus (LH). Our results suggest that alpha-chloralose and isoflurane anesthesia caused distinct effects on BOLD response to the gut l-Glu stimulation in several brain regions.

Human herpes virus 8-negative primary effusion lymphoma with BCL6 rearrangement in a patient with idiopathic CD4 positive T-lymphocytopenia.

Primary effusion lymphoma (PEL) was initially designated as a body-cavity-based lymphoma and recognized as a distinct clinical entity without a contiguous tumor mass. PEL was first reported in patients with acquired immunodeficiency syndrome (AIDS) and the distinctive feature of PEL originally reported as a B-cell neoplasm characterized by infection of the tumor cells by human herpes virus 8 (HHV-8). However, there have recently been several reports of PEL in patients without human immunodeficiency virus (HIV) or HHV-8 infection.

Metabolic interactions between restraint stress and L-lysine: the effect on urea cycle components.

We studied the effects of L-lysine on wrap-restraint stress-induced changes in ureagenesis. An exposure to wrap-restraint stress did not affect the plasma concentration of L-lysine, but did decrease plasma urea and arginine. Oral L-lysine (1 g/kg) blocked the effect of stress on ureagenesis, and enhanced the effect of stress on L-arginine. No influence of L-lysine were found in controls. The results imply a stress-specific, ureagenesis-stimulating effect of L-lysine, and suggest an increased requirement for L-arginine during the above conditions.

Early optical emission from the gamma-ray burst of 4 October 2002.

Observations of the long-lived emission--or 'afterglow'--of long-duration gamma-ray bursts place them at cosmological distances, but the origin of these energetic explosions remains a mystery. Observations of optical emission contemporaneous with the burst of gamma-rays should provide insight into the details of the explosion, as well as into the structure of the surrounding environment. One bright optical flash was detected during a burst, but other efforts have produced negative results. Here we report the discovery of the optical counterpart of GRB021004 only 193 seconds after the event. The initial decline is unexpectedly slow and requires varying energy content in the gamma-ray burst blastwave over the course of the first hour. Further analysis of the X-ray and optical afterglow suggests additional energy variations over the first few days.

Brief exposure to NaCl during early postnatal development enhances adult intake of sweet and salty compounds.

Taste acceptance involves both innate and acquired components. We observed an increased acceptance of salty and sweet solutions in adult rats whose tongues had been exposed to an NaCl-enriched milk formula during one day of early postnatal development. This behavioral effect was associated with changes in the norepinephrine system of the basolateral amygdala. No other changes in behavior, food intake, body weight, blood or metabolic parameters of the NaCl-exposed adult rats were identified. The data suggest a causal relationship between NaCl taste exposure, low content of amygdala norepinephrine cells and enhanced intake of sweet and salty compounds by adult rats. They also raise the question of the extent to which similar phenomena may occur during early human infant feeding.

Flavin reductase coupling with two monooxygenases involved in dibenzothiophene desulfurization: purification and characterization from a non-desulfurizing bacterium, Paenibacillus polymyxa A-1.

The dibenzothiophene (DBT) desulfurizing bacterium metabolizes DBT to form 2-hydroxybiphenyl without breaking the carbon skeleton. Of the DBT desulfurization enzymes, DszC and DszA catalyze monooxygenation reactions, both requiring flavin reductase. We searched for non-DBT-desulfurizing microorganisms producing a flavin reductase that couples more efficiently with DszC than that produced by the DBT desulfurizing bacterium Rhodococcus erythropolis D-1, and found Paenibacillus polymyxa A-1 to be a promising strain. The enzyme was purified to complete homogeneity. K(m) values for FMN and NADH were 2.1 microM and 0.57 mM, respectively. Flavin compounds were good substrates, some nitroaromatic compounds were also active, and regarding the electron donor, the activity for NADPH was about 1.5 times that for NADH. In the coupling assay with DszC, only FMN or riboflavin acted as the electron acceptor. The coupling reactions of P. polymyxa A-1 flavin reductase with DszC and DszA proceeded more efficiently (3.5- and 5-fold, respectively) than those of R. erythropolis D-1 flavin reductase when identical enzyme activities of each flavin reductase were added to the reaction mixture. The result of the coupling reaction suggested that, in the microbial DBT desulfurization, flavin reductase from the non-DBT-desulfurizing bacterium was superior to that from the DBT-desulfurizing bacterium.

Matrix metalloproteinases and tissue inhibitors of matrix metalloproteinases in sputum from patients with bronchial asthma.

To examine a possibility that matrix metalloproteinases (MMPs) participate in the pathogenesis of asthma and/or the development of asthma attack, we measured the concentrations of MMP-2, MMP-9, and their respective tissue inhibitors of metalloproteinases (TIMP)-2 and TIMP-1, in induced sputa collected from 28 patients with moderate to severe bronchial asthma. Specimens were collected during both the attack and the remission from 15 age- and sex-matched healthy control subjects. The concentration of MMP-9 was significantly (p < 0.05) higher in the patients, even during the remission, as compared to that in healthy controls. The concentrations of MMP-9 (p < 0.05) and its specific inhibitor TIMP-1 (p < 0.01), and MMP-2 (p < 0.01) in these patients during the attack were significantly higher than those in healthy controls. In these patients, the MMP-9 concentration was significantly higher (p < 0.05) during the attack than during the remission. These results suggest that MMPs and TIMPs may be involved in the pathogenesis of bronchial asthma, and that the increased MMP-9 might be involved in the development of attack in patients with chronic asthma.

Analysis of 168 short tandem repeat loci in the Japanese population, using a screening set for human genetic mapping.

We devised a multiplex polymerase chain reaction (PCR) amplification and loading system for the convenient typing of 168 short tandem repeat (STR) polymorphic markers in a commercially available screening primer set for human linkage analysis. We genotyped all these 168 STR loci with 32 healthy unrelated Japanese, calculated allele frequencies at each STR locus, and performed three kinds of tests for Hardy-Weinberg equilibrium (HWE). Significant deviations from HWE in all three tests were observed at only three loci, and the average heterozygosity in the Japanese (0.733) was slightly lower than that in Caucasians (0.773). We also examined 32 Caucasians at some selected loci, to be compared with Japanese. Some markers showed greatly different heterozygosities or allelic distributions in Japanese and Caucasian populations. In two groups of STRs, those with and without irregular alleles (or interalleles), the former had a higher proportion of bimodal allelic distribution and possessed more alleles per locus than the latter. However, no significant differences in the observed and expected heterozygosities, or in the powers of discrimination, were found between the two groups. The present basic study of allele frequency databases of these STRs will contribute to further applications in forensic science and human genetics.

In situ EXAFS study on the formation of smectite-type clays containing cobalt cations in lattice.

Smectite-type clays containing cobalt cations in octahedral sheets (MST (Co)) were prepared by a hydrothermal treatment of a water slurry of silicon-cobalt hydrous oxide prepared from water glass and cobalt chloride. The formation of silicate fragments having smectite-type structure was studied by EXAFS.

Dysregulated cytokine production in human cystic fibrosis bronchial epithelial cells.

Although pulmonary inflammation is an important pathologic event in cystic fibrosis (CF), the relationship between expression of the CF gene and the inflammatory response is unclear. We studied tumor necrosis factor (TNF) alpha and IL-1beta stimulated production of IL-6 and IL-8 by CF, corrected CF, and normal human bronchial epithelial cells in culture. During the first 24 hours of TNFalpha stimulation, CF cells produced significantly more IL-8 than normal or corrected CF cells. In the second 24 hours of TNFalpha stimulation, IL-6 and IL-8 generation ceased in normal and corrected CF cells but accelerated in CF cells, resulting in marked IL-6 and IL-8 accumulation in CF cells. Similar results were found when cells were stimulated with IL-1beta. Finally, when CF cells were grown at 27 degrees C (a culture condition which results in transport of CF transmembrane conductance regulator, CFTR, to the cell membrane and normalization of chloride conductance) TNFalpha-stimulated production of IL-6 and IL-8 reverted to normal. We conclude that dysregulation of cytokine generation by CF bronchial epithelial cells is directly related to expression of mutant CFTR and these observations provide a potential mechanism for persistence of airway inflammation in CF.