110 research outputs found
Differential Scanning Calorimetric Studies on the Melting Behavior of Water in Stratum Corneum
The melting behavior of water in human stratum corneum (s. corneum) has been studied by sing differential scanning calorimetry (DSC) in the temperature range from -40° to 20°C. The DSC thermogram was analyzed in terms of the amount of about water and the melting temperature of water in s. corneum. Extraction of the s. corneum with the mixed solvent of chloroform: methanol (2:1, v/v) or 0.5% sodium dodecyl sulfate aqueous solution decreased the bound water content, whereas extraction with water did not change the bound water content. The melting temperature of water in the s. corneum was lowered as the water contents decreased. Extraction of the water-soluble components from the s. corneum increased the melting temperature of water when the water contents were constant. The results suggest that 20–30% of water in the s. corneum is bound water interacting strongly with the protein or lipids in the s. corneum, and the excess of water over the bound water content is unbound water solubilizing the water-soluble components such as amino acids and urea in the s. corneum. The thermodynamic theory for freezing-point depression is favourably applied to the melting temperature change of the unbound water, which implies that the water-soluble components are present as an aqueous solution in the s. corneum. Measurements of the melting-point depression of water in s. corneum provides us the quantitative information on the amount of water-soluble components in the s. corneum. This technique is a sensitive and useful tool to evaluate the hydration behavior of s. corneum
Anti-Obesity and Anti-Diabetic Effects of Acacia Polyphenol in Obese Diabetic KKAy Mice Fed High-Fat Diet
Acacia polyphenol (AP) extracted from the bark of the black wattle tree (Acacia meansii) is rich in unique catechin-like flavan-3-ols, such as robinetinidol and fisetinidol. The present study investigated the anti-obesity/anti-diabetic effects of AP using obese diabetic KKAy mice. KKAy mice received either normal diet, high-fat diet or high-fat diet with additional AP for 7 weeks. After the end of administration, body weight, plasma glucose and insulin were measured. Furthermore, mRNA and protein expression of obesity/diabetic suppression-related genes were measured in skeletal muscle, liver and white adipose tissue. As a result, compared to the high-fat diet group, increases in body weight, plasma glucose and insulin were significantly suppressed for AP groups. Furthermore, compared to the high-fat diet group, mRNA expression of energy expenditure-related genes (PPARα, PPARδ, CPT1, ACO and UCP3) was significantly higher for AP groups in skeletal muscle. Protein expressions of CPT1, ACO and UCP3 for AP groups were also significantly higher when compared to the high-fat diet group. Moreover, AP lowered the expression of fat acid synthesis-related genes (SREBP-1c, ACC and FAS) in the liver. AP also increased mRNA expression of adiponectin and decreased expression of TNF-α in white adipose tissue. In conclusion, the anti-obesity actions of AP are considered attributable to increased expression of energy expenditure-related genes in skeletal muscle, and decreased fatty acid synthesis and fat intake in the liver. These results suggest that AP is expected to be a useful plant extract for alleviating metabolic syndrome
Production of α-Amylase by lmmobilized Cells of Asperlgillus oryzae in a Bubble Column Bioreactor
α-Amylase pmduction by Aspergillus oryzae IFO 30113 immobilized on a macropomus cellulose support in a bubble column bioreactor was investigated. The cells were attached to the support and grew well on the support in the bubble column bioreactor. The enzyme productivity of immobilized cells was almost the same as that given by free cells in batch culture. The enzyme was able to be reproduced by the immobilized cells in the bubble column bioreactor in repeated batch culture
Significance of adrenomedullin under cardiopulmonary bypass in children during surgery for congenital heart disease.
To elucidate the effect of adrenomedullin (AM) on fluid homeostasis under cardiopulmonary bypass (CPB), we investigated the serial changes in plasma AM and other parameters related to fluid homeostasis in 13 children (average age, 28.2 months) with congenital heart disease during cardiac surgery under CPB. Arterial blood and urine samples were collected just after initiation of anesthesia, just before commencement of CPB, 10 min before the end of CPB, 60 min after CPB, and 24 h after operation. Plasma AM levels increased significantly 10 min before the end of CPB and decreased 24 h after operation. Urine volume increased transiently during CPB, which paralleled changes in AM. Simple regression analysis showed that plasma AM level correlated significantly with urinary vasopressin, urine volume, urinary sodium excretion, and plasma osmolarity. Stepwise regression analysis indicated that urine volume was the most significant determinant of plasma AM levels. Percent rise in AM during CPB relative to control period correlated with that of plasma brain natriuretic peptide (r = 0.57, P < 0.01). Our results suggest that AM plays an important role in fluid homeostasis under CPB in cooperation with other hormones involved in fluid homeostasis.</p
Gauge transformations and symmetries of integrable systems
We analyze several integrable systems in zero-curvature form within the
framework of invariant gauge theory. In the Drienfeld-Sokolov gauge
we derive a two-parameter family of nonlinear evolution equations which as
special cases include the Kortweg-de Vries (KdV) and Harry Dym equations. We
find residual gauge transformations which lead to infinintesimal symmetries of
this family of equations. For KdV and Harry Dym equations we find an infinite
hierarchy of such symmetry transformations, and we investigate their relation
with local conservation laws, constants of the motion and the bi-Hamiltonian
structure of the equations. Applying successive gauge transformatinos of Miura
type we obtain a sequence of gauge equivalent integrable systems, among them
the modified KdV and Calogero KdV equations.Comment: 18pages, no figure Journal versio
Transcriptional Repression of Cdc25B by IER5 Inhibits the Proliferation of Leukemic Progenitor Cells through NF-YB and p300 in Acute Myeloid Leukemia
The immediately-early response gene 5 (IER5) has been reported to be induced by γ-ray irradiation and to play a role in the induction of cell death caused by radiation. We previously identified IER5 as one of the 2,3,4-tribromo-3-methyl-1-phenylphospholane 1-oxide (TMPP)-induced transcriptional responses in AML cells, using microarrays that encompassed the entire human genome. However, the biochemical pathway and mechanisms of IER5 function in regulation of the cell cycle remain unclear. In this study, we investigated the involvement of IER5 in the cell cycle and in cell proliferation of acute myeloid leukemia (AML) cells. We found that the over-expression of IER5 in AML cell lines and in AML-derived ALDHhi (High Aldehyde Dehydrogenase activity)/CD34+ cells inhibited their proliferation compared to control cells, through induction of G2/M cell cycle arrest and a decrease in Cdc25B expression. Moreover, the over-expression of IER5 reduced colony formation of AML-derived ALDHhi/CD34+ cells due to a decrease in Cdc25B expression. In addition, over-expression of Cdc25B restored TMPP inhibitory effects on colony formation in IER5-suppressed AML-derived ALDHhi/CD34+ cells. Furthermore, the IER5 reduced Cdc25B mRNA expression through direct binding to Cdc25B promoter and mediated its transcriptional attenuation through NF-YB and p300 transcriptinal factors. In summary, we found that transcriptional repression mediated by IER5 regulates Cdc25B expression levels via the release of NF-YB and p300 in AML-derived ALDHhi/CD34+ cells, resulting in inhibition of AML progenitor cell proliferation through modulation of cell cycle. Thus, the induction of IER5 expression represents an attractive target for AML therapy
Increase of Total Nephron Albumin Filtration and Reabsorption in Diabetic Nephropathy
There is a hot debate concerning actual amount of albumin filtered through glomeruli and reabsorbed at proximal tubules in normal kidneys and diabetic conditions. To overcome current technical problems, we generated a drug-inducible megalin knockout mouse line, megalin(lox/lox);Ndrg1-CreER[T2] (or iMegKO), whose protein reabsorption can be shut off anytime by tamoxifen (Tam). After Tam administration, renal megalin protein expression was reduced by 92% compared to wild-type C57BL/6J mice, and renal reabsorption of intravenously-injected retinol binding protein was almost completely abrogated. Urinary albumin excretion increased to 175 μg/day (0.460 mg/mg-creatinine), suggesting that this was the amount of total nephron albumin filtration. Glomerular sieving coefficient of albumin was 1.7 x 10[-5]. By comparing streptozotocin-induced, Tam-treated, diabetic STZ;iMegKO mice with non-STZ;iMegKO mice, we estimated that daily albumin filtration was increased by 1.9-fold, reabsorption was increased by 1.8-fold, and reabsorption efficiency was reduced to 86% by development of diabetes (versus 96% in control). Such abnormalities were well normalized after insulin treatment. Another type 1 diabetic model of Akita;iMegKO mice showed equivalent results. This study reveals actual values and changes of albumin filtration and reabsorption in early diabetic nephropathy, bringing new insights into our understanding of renal albumin dynamics in hyperfiltration status of diabetic nephropath
Natriuretic peptide receptor guanylyl cyclase-A pathway counteracts glomerular injury evoked by aldosterone through p38 mitogen-activated protein kinase inhibition
Guanylyl cyclase-A (GC-A) signaling, a natriuretic peptide receptor, exerts renoprotective effects by stimulating natriuresis and reducing blood pressure. Previously we demonstrated massive albuminuria with hypertension in uninephrectomized, aldosterone-infused, and high salt-fed (ALDO) systemic GC-A KO mice with enhanced phosphorylation of p38 mitogen-activated protein kinase (MAPK) in podocytes. In the present study, we examined the interaction between p38 MAPK and GC-A signaling. The administration of FR167653, p38 MAPK inhibitor, reduced systolic blood pressure (SBP), urinary albumin excretion, segmental sclerosis, podocyte injury, and apoptosis. To further investigate the local action of natriuretic peptide and p38 MAPK in podocytes, we generated podocyte-specific (pod) GC-A conditional KO (cKO) mice. ALDO pod GC-A cKO mice demonstrated increased urinary albumin excretion with marked mesangial expansion, podocyte injury and apoptosis, but without blood pressure elevation. FR167653 also suppressed urinary albumin excretion without reducing SBP. Finally, we revealed that atrial natriuretic peptide increased phosphorylation of MAPK phosphatase-1 (MKP-1) concomitant with inhibited phosphorylation of p38 MAPK in response to MAPK kinase 3 activation, thereby resulting in decreased mRNA expression of the apoptosis-related gene, Bax, and Bax/Bcl2 ratio in cultured podocytes. These results indicate that natriuretic peptide exerts a renoprotective effect via inhibiting phosphorylation of p38 MAPK in podocytes.</p
Perioperative plasma melatonin concentration in postoperative critically ill patients: Its association with delirium
Purpose: Delirium is a common complication in postoperative critically ill patients. Although abnormal melatonin metabolism is thought to be one of the mechanisms of delirium, there have been few studies in which the association between alteration of perioperative plasma melatonin concentration and postoperative delirium was assessed.
Materials: We conducted a prospective observational study to assess the association of perioperative alteration of plasma melatonin concentration with delirium in 40 postoperative patients who required intensive care for more than 48 hours. We diagnosed postoperative delirium using Confusion Assessment Method for the intensive care unit and measured melatonin concentration 4 times (before the operation as the preoperative value, 1 hour after the operation, postoperative day 1, and postoperative day 2).
Results: Postoperative delirium occurred in 13 (33%) of the patients. Although there was no significant difference in preoperative melatonin concentration, Delta melatonin concentration at 1 hour after the operation was significantly lower in patients with delirium than in those without delirium (-1.1 vs 0 pg/mL, P = .036). After adjustment of relevant confounders, Delta melatonin concentration was independently associated with risk of delirium (odds ratio, 0.50; P = .047).
Conclusions: Delta melatonin concentration at 1 hour after the operation has a significant independent association with risk of postoperative delirium. (c) 2013 Elsevier Inc. All rights reserved
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