Metabolites present in human blood document individual physiological states influenced by genetic, epigenetic, and lifestyle factors. Using high-resolution liquid chromatography-mass spectrometry (LC-MS), we performed nontargeted, quantitative metabolomics analysis in blood of 15 young (29 ± 4 y of age) and 15 elderly (81 ± 7 y of age) individuals. Coefficients of variation (CV = SD/mean) were obtained for 126 blood metabolites of all 30 donors. Fiftyfive RBC-enriched metabolites, for which metabolomics studies have been scarce, are highlighted here. We found 14 blood compounds that show remarkable age-related increases or decreases; they include 1,5-anhydroglucitol, dimethyl-guanosine, acetyl-carnosine, carnosine, ophthalmic acid, UDP-acetyl-glucosamine, N-acetyl-arginine, N 6 -acetyl-lysine, pantothenate, citrulline, leucine, isoleucine, NAD + , and NADP + . Six of them are RBC-enriched, suggesting that RBC metabolomics is highly valuable for human aging research. Age differences are partly explained by a decrease in antioxidant production or increasing inefficiency of urea metabolism among the elderly. Pearson's coefficients demonstrated that some age-related compounds are correlated, suggesting that aging affects them concomitantly. Although our CV values are mostly consistent with those CVs previously published, we here report previously unidentified CVs of 51 blood compounds. Compounds having moderate to high CV values (0.4-2.5) are often modified. Compounds having low CV values, such as ATP and glutathione, may be related to various diseases because their concentrations are strictly controlled, and changes in them would compromise health. Thus, human blood is a rich source of information about individual metabolic differences. H uman blood metabolites have been well-investigated to determine their abundance and biological significance, and for their potential use as diagnostic markers. For medical diagnosis, noncellular metabolites from plasma or serum are mostly commonly used due to the simplicity in collecting and examining them. Although mature human red blood cells (RBCs) lack nuclei and cellular organelles (1), RBCs use glycolysis for ATP production, maintain redox homeostasis, and osmoregulate (2). Their active metabolism supports cellular homeostasis and ensures lifespans of ∼4 mo (3). Their metabolites may reflect health status or environmental stresses differently than do metabolites of plasma. Because RBCs occupy about half the total blood volume (∼5 L), their metabolite profiles, which have scarcely been investigated, seemed worthy of investigation.Metabolomics is a branch of chemical biology that profiles metabolites in cells and organisms, using techniques such as liquid chromatography (LC)-mass spectrometry (MS). It usually deals with molecules <1.5 kDa and is an important tool for studying metabolic regulation in combination with other comprehensive analyses, such as proteomics and transcriptomics. Recently, we reported that, among 133 compounds identified in human blood, 101 are also found...

During human fasting, metabolic markers, including butyrates, carnitines, and branched-chain amino acids, are upregulated for energy substitution through gluconeogenesis and use of stored lipids. We performed non-targeted, accurate semiquantitative metabolomic analysis of human whole blood, plasma, and red blood cells during 34–58 hr fasting of four volunteers. During this period, 44 of ~130 metabolites increased 1.5~60-fold. Consistently fourteen were previously reported. However, we identified another 30 elevated metabolites, implicating hitherto unrecognized metabolic mechanisms induced by fasting. Metabolites in pentose phosphate pathway are abundant, probably due to demand for antioxidants, NADPH, gluconeogenesis and anabolic metabolism. Global increases of TCA cycle-related compounds reflect enhanced mitochondrial activity in tissues during fasting. Enhanced purine/pyrimidine metabolites support RNA/protein synthesis and transcriptional reprogramming, which is promoted also by some fasting-related metabolites, possibly via epigenetic modulations. Thus diverse, pronounced metabolite increases result from greatly activated catabolism and anabolism stimulated by fasting. Anti-oxidation may be a principal response to fasting.

During human fasting, metabolic markers, including butyrates, carnitines, and branched-chain amino acids, are upregulated for energy substitution through gluconeogenesis and use of stored lipids. We performed non-targeted, accurate semiquantitative metabolomic analysis of human whole blood, plasma, and red blood cells during 34-58 hr fasting of four volunteers. During this period, 44 of ~130 metabolites increased 1.5~60-fold. Consistently fourteen were previously reported. However, we identified another 30 elevated metabolites, implicating hitherto unrecognized metabolic mechanisms induced by fasting. Metabolites in pentose phosphate pathway are abundant, probably due to demand for antioxidants, NADPH, gluconeogenesis and anabolic metabolism. Global increases of TCA cyclerelated compounds reflect enhanced mitochondrial activity in tissues during fasting. Enhanced purine/ pyrimidine metabolites support RNA/protein synthesis and transcriptional reprogramming, which is promoted also by some fasting-related metabolites, possibly via epigenetic modulations. Thus diverse, pronounced metabolite increases result from greatly activated catabolism and anabolism stimulated by fasting. Anti-oxidation may be a principal response to fasting.

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Cellular nutrient states control whether cells proliferate, or whether they enter or exit quiescence. Here, we report characterizations of fission yeast temperature-sensitive (ts) mutants of the evolutionarily conserved transmembrane protein Cwh43, and explore its relevance to utilization of glucose, nitrogen source and lipids. GFP-tagged Cwh43 localizes at ER associated with the nuclear envelope and the plasma membrane, as in budding yeast. We found that mutants failed to divide in low glucose and lost viability during quiescence under nitrogen starvation. In mutants, comprehensive metabolome analysis demonstrated dramatic changes in marker metabolites that altered under low glucose and/or nitrogen starvation, although cells apparently consumed glucose in the culture medium. Furthermore, we found that mutant cells had elevated levels of triacylglycerols (TGs) and coenzyme A, and that they accumulated lipid droplets. Notably, TG biosynthesis was required to maintain cell division in the mutant. Thus, Cwh43 affects utilization of glucose and nitrogen sources, as well as storage lipid metabolism. These results may fit a notion developed in budding yeast stating that Cwh43 conjugates ceramide to glycosylphosphatidylinositol (GPI)-anchored proteins and maintains integrity of membrane organization.

Pressure controlled ventilation is a common mode of ventilation used to manage both adult and pediatric populations. However, there is very little evidence that distinguishes the efficacy of pressure controlled ventilation over that of volume controlled ventilation in the adult population. This gap in the literature may be due to the absence of a consistent and systematic algorithm for managing pressure controlled ventilation. This article provides a brief overview of the applications of both pressure controlled ventilation and volume controlled ventilation and proposes an algorithmic approach to the management of patients receiving pressure controlled ventilation. This algorithmic approach highlights the need for clinicians to have a comprehensive conceptual understanding of mechanical ventilation, pulmonary physiology, and interpretation of ventilator graphics in order to best care for patients receiving pressure controlled ventilation. The objective of identifying a systematic approach to managing pressure controlled ventilation is to provide a more generalizable and equitable approach to management of the ICU patient. Ideally, a consistent approach to managing pressure controlled ventilation in the adult population will glean more reliable information regarding actual patient outcomes, as well as the efficacy of pressure controlled ventilation when compared to volume controlled ventilation.

Introduction: To assess cognitive impairment, self-awareness is an important issue. The Ascertain Dementia 8 questionnaire (AD8) is a brief observation checklist for detecting mild cognitive impairment (MCI) and dementia. After analyzing the reliability and validity of a self-reported Japanese version of the AD8 (AD8-J), we compared self- and informant-reported versions of the AD8-J. Methods: A total of 93 community residents aged 75 years or older living in Wakuya, Northern Japan, agreed to participate in this study; 35 were rated as Clinical Dementia Rating (CDR) 0 (healthy), 46 as CDR 0.5 (defined herein as MCI), and 12 as CDR 1 or above (dementia, confirmed by the DSM-IV). We examined the reliability and validity using a receiver operating characteristic (ROC) curve. We analyzed the differences between self-reported and informant-reported AD8-J using a repeated measures ANOVA. Results: The self-reported AD8-J showed a satisfactory reliability (i.e., Cronbach coefficient, α = 0.71; Guttman split half method coefficient = 0.60). For CDR 0 vs. CDR 0.5 or above, the area under the ROC curve was 0.74 and the cutoff score was 1/2, with a sensitivity of 70.7% and a specificity of 65.7%. Analysis of the subscores of AD8 suggested that, from the early stage of dementia, the subjects showed a subjective decline in memory and interest in hobbies/activities, as well as problems with judgment. Conclusion: It is suggested that the self-reported AD8-J was effective in detecting MCI and dementia. We could use it for detecting MCI and dementia, including in those living alone, in the primary health checkup.

Keratan sulfate is a sulfated polysaccharide classified as a glycosaminoglycan, which has the structurally unique characteristics of diversity in the linker oligosaccharides connecting to the core protein, the existence of both an intrachain fucose branch and a "capping" monosaccharide at the nonreducing end, and diversity of the sulfation patterns. The function(s) of this newest glycosaminoglycan, keratan sulfate, remain mostly unclear. In this minireview, we describe the structures and known functions of keratan sulfate as well as cutting-edge methods to enable the synthesis of keratan sulfate with complex structures. A. Introduction Sulfated sugars are widely distributed in many living systems, from plants to animals, and exist in various forms from low-molecular-weight glycosides to polysaccharides (1-4). Many of these sulfo-sugars exhibit their biological functions through interactions with specific proteins; a sulfate group often functions as the key for these interactions. In the animal kingdom, almost all sulfo-sugars are found as glycosaminoglycans (GAGs), which include polysaccharide members consisting of hyaluronan (HA), heparan sulfate (HS)/heparin (Hep), chondroitin sulfate (CS)/dermatan sulfate (DS) and keratan sulfate (KS) (Fig. 1) (3). GAGs are linear copolymers of alternating uronic acids (glucuronic acid and iduronic acid) and hexosamines [glucosamine (GlcN) and galactosamine], which have sulfate groups (O-and/or N-) at varying frequencies (except HA); however, KS contains Gal instead of a uronic acid, and often an α-Fuc branch at the C3 of GlcNAc. GAGs except HA exist as the carbohydrate parts of glycoproteins called proteoglycans (PGs) that connect to core proteins through "linker" oligosaccharides (HS/Hep and CS/DS: O-glycans, KS: N-and O-glycans). In Fig. 1, disaccharide structures are shown as the typical repeating units of GAGs, but these have additional sulfation patterns. In addition, CS contains DS units at varying ratios, while HS also contains Hep units, and vice versa. Thus, taking these sulfation patterns into account, it becomes clear that GAGs have extremely complex, heterologous structures even within a GAG class; this makes investigating their functions extremely difficult. Despite these conditions, significant knowledge has been revealed through the efforts of many researchers, especially in the cases of HA (5), HS (6) and CS (7). In contrast, few research reports have been published on KS as compared to other GAGs since its discovery in 1939 (8), and it has mostly into oblivion. In this mini-review, the state-of-the-art results from these "old and new" KS studies, along with future perspectives, are discussed. B. Keratan Sulfate B-1. Structures and Classification As described above, KS contains Gal residues instead of uronic acids; a unique difference from other GAGs. Because of this, KS has a type II polylactosamine chain consisting of Gal and GlcNAc alternately connecting through β(1 4)-and β(1 3)glycosidic linkages, respectively; the C6 of GlcNAc is always sulfated (9). In ...