Relationship between effect of polymyxin B-immobilized fiber and high-mobility group box-1 protein in septic shock patients

Direct hemoperfusion (DHP) using a polymyxin B (PMX)-immobilized fiber column has been used for treatment of endotoxemia-induced septic shock in Japan since 1994 and is now an accepted therapy for reducing serum endotoxin levels. Although a reduction in inflammatory cytokines has been reported, the detailed mechanism of DHP-PMX is not known. We investigated the high-mobility group box-1 (HMGB-1) level in septic shock patients treated with DHP-PMX. Subjects (n = 20) were separated into two group: those whose systolic blood pressure increased to more than 30 mm Hg immediately after DHP-PMX (effective [E] group: nine cases) and those whose systolic blood pressure did not increase to more than 30 mm Hg (noneffective [N-E] group: 11 cases). The interleukin-6, plasminogen activator inhibitor-1, and HMGB-1 levels were measured in each group. The Pao2/Fio2 ratio and the Sepsis-Related Organ Failure Assessment (SOFA) score were also evaluated. Pretreatment interleukin-6, plasminogen activator inhibitor-1, and HMGB-1 levels were similar in the E and N-E groups, but mortality rate was significantly higher in the N-E group. Furthermore, posttreatment SOFA score was significantly lower in the E group. In the E group, only the HMGB-1 levels improved significantly after DHP-PMX. Present data suggest that the circulation dynamics of septic shock patients can be improved by reducing HMGB-1 levels by using DHP-PMX.     

SAR Exploration Guided by LE and Fsp3: Discovery of a Selective and Orally Efficacious RORγ Inhibitor

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Blocking actions of glibenclamide on ATP-sensitive K+ channels in pig urethral myocytes

The inhibitory effects of glibenclamide on the levcromakalim-induced ATP-sensitive K+ (K(ATP)) channels were investigated with cell-attached configuration in pig proximal urethra. Application of 10 microM glibenclamide reversibly inhibited the activity of the 100 microM levcromakalim-induced K(ATP) channel, decreasing not only the channel open probability but also the amplitude of unitary current. The inhibitory concentration-response curve of the glibenclamide-induced sublevel conductance of K(ATP) channel was shifted to the right (IC50 = 4.7 microM), compared with the levcromakalim-induced K(ATP) channel (full conductance, IC50 = 0.5 microM). Glibenclamide is the first reported sulphonylurea to selectively block K(ATP) channel, not only by decreasing the channel activity but also by reducing the unitary amplitude in smooth muscle.     

Synthesis and evaluation of bibenzyl glycosides as potent tyrosinase inhibitors

Bibenzyl glycosides 1-6 were synthesized from 2,4-dihydoxybenzaldehyde and xylose, glucose, cellobiose or maltose. The key steps in the synthesis were the Wittig reaction and trichloroacetimidate glycosylation. Tests for tyrosinase inhibitory activity showed that all were significantly active, indicating that they are unique hydrophilic tyrosinase inhibitors. Bibenzyl xyloside 2 is a particularly potent inhibitor (IC₅₀ = 0.43 μM, 17 times higher than that of kojic acid). These results suggest that the hydrophilic cavity of tyrosinase might accommodate the bulky carbohydrate on the bibenzyl scaffold.     

Comparative studies of ZD0947, a novel ATP-sensitive K<Superscript>+</Superscript> channel opener,on guinea pig detrusor and aortic smooth muscles

The effects of ZD0947, a novel urinary bladder selective ATP-sensitive potassium channel (K_ATP channel) opener, on carbachol-induced contractions of isolated guinea pig urinary bladder strips were investigated to compare its ability to relax norepinephrine-induced contraction of the aorta. Electrophysiological techniques were also utilized to compare the effects of ZD0947 on membrane currents between guinea pig detrusor and aortic myocytes. ZD0947 caused a significant reduction of the carbachol-induced contractile activity, demonstrating a biphasic relaxation (the first and second components). Although glibenclamide antagonized the effects of two components for the ZD0947-induced relaxation, gliclazide, a selective sulphonylurea receptor 1 (SUR1) antagonist, reduced the effects of the first component but not the second component of the ZD0947-induced relaxation. ZD0947 also reduced the norepinephrine-induced contraction of the aorta. ZD0947 reduced electrical excitability of detrusor smooth muscles, inhibiting spike discharges and also hyperpolarizing the membrane as measured with microelectrodes. In conventional whole-cell configuration, ZD0947 caused a glibenclamide-sensitive K⁺ current (i.e., K_ATP current) at a holding potential of −60 mV in guinea pig detrusor and aortic myocytes. The current density of ZD0947-induced K_ATP currents in guinea pig detrusor myocytes was significantly larger than that in aortic smooth muscle cells. These results show that ZD0947 caused a significant relaxation through the activation of K_ATP channels in detrusor muscle.     

Effect of three flavonoids isolated from Japanese Polygonum species on superoxide generation in human neutrophils

Three flavonoids, quercetin 3- O-glucoside-2'-gallate (QGG), quercetin 3- O-rhamnoside-2'-gallate (QRG) and kaempferol 3- O-glucoside-2'-gallate (KGG) were isolated from Japanese Polygonum species. The effect of these flavonoids on stimulus-induced superoxide generation in human neutrophils was assayed by measuring the reduction of cytochrome c. The tyrosyl or serine/threonine phosphorylation of neutrophil proteins and the translocation of p4(phox) and p67(phox) to the cell membrane were detected using specific monoclonal antibodies. The flavonoids used in this experiment significantly suppressed stimulus-induced superoxide generation in a concentration-dependent manner. FMLP-induced tyrosyl phosphorylation or PMA-induced serine/threonine phosphorylation and the translocation of the cytosolic proteins p47(phox) and p67(phox) to the cell membrane were suppressed in parallel to the suppression of the stimulus-induced superoxide generation.     

Epigenetic inactivation of TFPI-2 as a common mechanism associated with growth and invasion of pancreatic ductal adenocarcinoma

Using microarrays, we have screened for genes reactivated by drugs that modify epigenetic mechanisms in pancreatic cancer cells. One of the genes identified was tissue factor pathway inhibitor 2 (TFPI-2), which encodes for a broad-spectrum serine proteinase inhibitor that negatively regulates the extracellular matrix degradation, an essential step in tumor invasion and metastasis. We therefore investigated the expression and methylation patterns of the TFPI-2 gene in pancreatic adenocarcinoma, and determined its role in tumor growth and invasion. In contrast to its abundant expression in normal pancreas, TFPI-2 mRNA was undetectable in a high fraction of pancreatic cancer cell lines and in primary pancreatic ductal neoplasms (IPMNs). Loss of TFPI-2 expression was associated with aberrant hypermethylation of its promoter CpG island. Treatment with the phorbol ester (PMA), known to stimulate the TFPI-2 promoter activity, augmented the TFPI-2 expression in cell lines with unmethylated or partially methylated TFPI-2, but failed to induce the expression in cell lines that harbored fully methylated TFPI-2. Aberrant methylation of TFPI-2 was also detected in 73% (102/140) of pancreatic cancer xenografts and primary pancreatic adenocarcinomas, was more likely in older patients with pancreatic cancer, and significantly correlated with progression of IPMNs (P=0.0002). Restored expression of the TFPI-2 gene in nonexpressing pancreatic cancer cells resulted in marked suppression in their proliferation, migration, and invasive potential in vitro. We thus conclude that epigenetic inactivation of TFPI-2 is a common mechanism that contributes to the aggressive phenotype of pancreatic ductal adenocarcinoma.     

Molecular and electrophysiological investigation of ATP-sensitive K+ channels in lower urinary tract function: the aims for clinical treatment of unstable detrusor

It is a common sequelae of bladder outlet obstruction caused by benign prostatic hyperplasia in adult males and gives rise to significant bladder dysfunction such as frequency and urgency of micturition. The unstable detrusor contractions may lead to urge incontinence. Since it has been reported that experimentally-induced bladder instability can be abolished by ATP-sensitive K+ channel (KATP channel) openers, various types of detrusor-selective KATP channels have been newly synthesized, targeting KATP channels in urinary bladder. Thus, the significant differences in molecular and pharmacological properties of KATP channels between urinary bladder and urethra hold out some hope for the development of tissue-selective KATP channel openers for urge urinary incontinence, and detrusor-selective KATP channel openers should be screened against urethral as well as vascular smooth muscle. In functional expression experiments, pharmacological and electrophysiological studies have reported that SUR1/Kir6.2 represents the pancreatic beta-cell KATP channel and that SUR2A/Kir6.2 is thought to represent the cardiac KATP channel, whereas SUR2B/Kir6.1 represents the smooth muscle-type KATP channel. In general, the smooth muscle type-KATP channel is (i) of a relatively small conductance (about 20 pS under quasi-physiological conditions, approximately 40 pS in symmetrical 140 mM K+ conditions), (ii) intracellular Ca(2+)-insensitive, (iii) inhibited by intracellular ATP, (iv) abolished by glibenclamide at a submicromolar concentration, and (v) reactivated by intracellular nucleoside diphosphates (NDPs). There has been no report concerning the properties of KATP channels in human detrusor by use of single-channel recordings. We would like to introduce our recent evidence of novel synthesized detrusor-selective KATP channel openers and properties of KATP channels in the lower urinary tract.     

Comparison of the clinical outcomes of nilotinib and dasatinib therapies in newly diagnosed patients in the chronic phase of chronic myeloid leukemia: a retrospective analysis

Treatment with a tyrosine kinase inhibitor (TKI) is the standard of care for patients with chronic myeloid leukemia (CML). The new-generation TKIs, nilotinib and dasatinib, are found to have deeper and faster treatment response rates compared to imatinib in the first-line setting. However, a direct comparison between nilotinib and dasatinib has never been reported previously. Our study aims to compare the outcomes and molecular responses achieved following the first-line use of these two agents in patients with CML-CP. The database of the CML Cooperative Study Group was reviewed and patients with CML in the chronic phase (CP) who were given nilotinib or dasatinib as first-line therapy were identified. Out of 361 patients with CML-CP enrolled in our database, 58 and 63 had been treated with conventional doses of nilotinib (300 mg twice daily) and dasatinib (100 mg once daily), respectively, as first-line therapy. The patient demographics did not show significant differences between the groups. The event-free survival rates did not differ between these two groups. The major molecular response (MMR) and the deep molecular response (DMR) rates by 6, 12, 18, and 24 months did not differ between groups. Among the three scoring systems, only the Hasford score could predict the achievement of DMR, and all of them failed to predict the achievement of MMR in the entire cohort. Our data suggest that both nilotinib and dasatinib have comparable efficacies and promising outcomes.