173 research outputs found
Carrier-mediated active transport of the glucuronide and sulfate of 6- hydroxy-5,7-dimethyl-2-methylamino-4-(3-pyridylmethyl) benzothiazole (E3040) into rat liver: quantitative comparison of permeability in isolated hepatocytes, perfused liver and liver i
ABSTRACT The hepatic uptake of glucuronic acid and sulfate conjugates of 6-hydroxy-5,7-dimethyl-2-methylamino-4-(3-pyridylmethyl) benzothiazole (E3040), a dual inhibitor of 5-lipoxygenase and thromboxane A 2 synthetase, was investigated in rats. The biliary excretion clearance values for the glucuronide and the sulfate, obtained after i.v. administration of E3040, were similar and corresponded to approximately 30% of the hepatic blood flow rate. The influx clearance values of E3040 conjugates in the presence of 3% bovine serum albumin, measured by a multiple indicator dilution method in the perfused liver, were 1.20 ml/min/g liver for the glucuronide and 0.74 ml/min/g liver for the sulfate, which were twice and equal to the normal hepatic plasma flow rate, respectively, which suggests the presence of an efficient transport system(s). The uptake of E3040 conjugates into the isolated hepatocytes is mediated by Na ϩ -independent active transport system(s), which is inhibited by dibromosulfophthalein and bile acids. The uptake for the sulfate had high-affinity and high-capacity transport activity (K m ϭ 25 M; V max ϭ 7.8 nmol/min/10 6 cells) compared with that for the glucuronide (K m ϭ 59 M; V max ϭ 2.2 nmol/min/10 6 cells). The uptakes of E3040 conjugates (glucuronide, sulfate) exhibited a mutual competitive inhibition. It is suggested that both conjugates share a multispecific organic anion transporter located on the sinusoidal membrane. Conjugative metabolism, such as glucuronidation and sulfation, is an important pathway for the inactivation or detoxification of xenobiotics. On the other hand, conjugative metabolites of certain drugs with pharmacologically active (such as the 6-glucuronide of morphine; In previous studies, we reported the disposition of glucuronide and sulfate of E3040, a novel dual inhibitor of 5-lipoxygenase and thromboxane A 2 synthetase, after administration Received for publication May 24, 1996. ABBREVIATIONS: E3040, 6-hydroxy-5,7-dimethyl-2-methylamino-4-(3-pyridylmethyl) benzothiazole; [ C]E3040, [2- 14 C]6-hydroxy-5,7-dimethyl-2-methylamino-4-(3-pyridylmethyl) benzothiazole dihydrochloride; SD rats, Sprague-Dawley rats; DBSP, dibromosulfophthalein; HEPES, N-2-hydroxyethylpiperazine-NЈ-2-ethanesulfonic acid; MID method, multiple indicator dilution method; HPLC, high-performance liquid chromatography; BSA, bovine serum albumin; TLC, thin-layer chromatography; AUC ϱ , the area under the plasma concentration-time profiles from zero to infinity; CL bile , the biliary excretion clearance; CL renal , the urinary excretion clearance; CL u,renal , the unbound urinary excretion clearance; X bile , the amount excreted into the bile; X urine , the amount excreted into the urine; CL tot , the total body clearance; PS inf , the influx clearance; PS u,inf , the unbound influx clearance; K inf , the influx rate constant; K eff , the efflux rate constant; K seq , the sequestration rate constant; K m , Michaelis constant; V max , maximal uptake rate; P dif , the nonspecific uptake clearance; LUR, the first-pass liver uptake ratio; UWL, the unstirred water layer; PCMBS, p-chloromercuriphenylsulfonic acid; DIDS, 4,4Ј-diisothiocyanatostilbene-2,2Ј-disulfonic acid; FCCP, carbonyl cyanide-p-(trifluoromethoxy)-phenylhydrazone; C/M, cell-to-medium concentration
Research and Development Work on Lithium-ion Batteries for Environmental Vehicles
Interest in electric vehicles (EVs) and hybrid electric vehicles (HEVs) has risen dramatically on account of environmental and energy concerns. The biggest issues that must be addressed in order to popularize these advanced vehicles are related to the battery.We have been promoting vigorous R&
D work on batteries for application to environmental vehicles since the beginning of the 1990s. Attention was focused on lithium-ion batteries early on as a fundamental solution to the critical issue mentioned above. The conclusion was reached that the development of those potentialities to their fullest extent would create completely new forms of value unobtainable with conventional batteries. As a result of extensive theoretical studies and many experimental demonstrations, we successfully showed ahead of others that those potentialities did in fact exist and could be achieved.This paper makes clear the various performance requirements of advanced batteries for EV or HEV application, focusing in particular on the critical aspects of the battery thermal design and construction for system stability. It also explains how the power output of the lithium-ion battery has been substantially improved for application to HEVs.
Document type: Articl
Integrated optics europium aluminum polymer optical waveguide with graded index circular core
A Europium Aluminum Benzyl Methacrylate (Eu-Al/BzMA) integrated optical waveguide with 50 μm graded-index multimode circular core is fabricated by applying the Mosquito method for the potential application of optical interconnect. The parabolic index profile of the waveguide core is measured to confirm the profile exhibited by the waveguide. A preliminary experiment of the signal transmission is performed at 26 Gb/s to evaluate its capability in high dense and speed optical interconnections. According to the results, the waveguide successfully demonstrated free bit-error-rate through 5 cm waveguide transmission
KUS121, a VCP modulator, has an ameliorating effect on acute and chronic heart failure without calcium loading via maintenance of intracellular ATP levels
KUS121は新規の心不全治療薬となる --Ca2+負荷なしに血行動態を改善--. 京都大学プレスリリース. 2023-12-15.[Aims] As heart failure (HF) progresses, ATP levels in myocardial cells decrease, and myocardial contractility also decreases. Inotropic drugs improve myocardial contractility but increase ATP consumption, leading to poor prognosis. Kyoto University Substance 121 (KUS121) is known to selectively inhibit the ATPase activity of valosin-containing protein, maintain cellular ATP levels, and manifest cytoprotective effects in several pathological conditions. The aim of this study is to determine the therapeutic effect of KUS121 on HF models. [Methods and results] Cultured cell, mouse, and canine models of HF were used to examine the therapeutic effects of KUS121. The mechanism of action of KUS121 was also examined. Administration of KUS121 to a transverse aortic constriction (TAC)-induced mouse model of HF rapidly improved the left ventricular ejection fraction and improved the creatine phosphate/ATP ratio. In a canine model of high frequency-paced HF, administration of KUS121 also improved left ventricular contractility and decreased left ventricular end-diastolic pressure without increasing the heart rate. Long-term administration of KUS121 to a TAC-induced mouse model of HF suppressed cardiac hypertrophy and fibrosis. In H9C2 cells, KUS121 reduced ER stress. Finally, in experiments using primary cultured cardiomyocytes, KUS121 improved contractility and diastolic capacity without changing peak Ca²⁺ levels or contraction time. These effects were not accompanied by an increase in cyclic adenosine monophosphate or phosphorylation of phospholamban and ryanodine receptors. [Conclusions] KUS121 ameliorated HF by a mechanism totally different from that of conventional catecholamines. We propose that KUS121 is a promising new option for the treatment of HF
Postoperative Radiographic Early-Onset Adjacent Segment Degeneration after Single-Level L4–L5 Posterior Lumbar Interbody Fusion in Patients without Preoperative Severe Sagittal Spinal Imbalance
Study Design Retrospective study. Purpose To investigate the relationship between preoperative total spinal sagittal alignment and the early onset of adjacent segment degeneration (ASD) after single-level posterior lumbar interbody fusion (PLIF) in patients with normal sagittal spinal alignment. Overview of Literature Postoperative early-onset ASD is one of the complications after L4–L5 PLIF, a common surgical procedure for lumbar degenerative disease in patents without severe sagittal imbalance. A better understanding of the preoperative characteristics of total spinal sagittal alignment associated with early-onset ASD could help prevent the condition. Methods The study included 70 consecutive patients diagnosed with lumbar degenerative disease who underwent single-level L4–L5 PLIF between 2011 and 2015. They were divided into two groups based on the radiographic progression of L3–L4 degeneration after 1-year follow-up: the ASD and the non-ASD (NASD) group. The following radiographic parameters were preoperatively and postoperatively measured: sagittal vertebral axis (SVA), thoracic kyphosis (TK), lumbar lordosis, pelvic tilt, and pelvic incidence (PI). Results Eight of the 70 patients (11%) experienced ASD after PLIF (three males and five females; age, 64.4±7.7 years). The NASD group comprised 20 males and 42 females (age, 67.7±9.3 years). Six patients of the ASD group showed decreased L3–L4 disc height, one had L3–L4 local kyphosis, and one showed both changes. Preoperative SVA, PI, and TK were significantly smaller in the ASD group than in the NASD group (p <0.05). Conclusions A preoperative small SVA and TK with small PI were the characteristic alignments for the risk of early-onset ASD in patients without preoperative severe sagittal spinal imbalance undergoing L4–L5 single-level PLIF
Inhibition of microRNA-33b in humanized mice ameliorates nonalcoholic steatohepatitis
マイクロRNA-33bの阻害は非アルコール性脂肪肝炎を改善する --核酸医薬による治療応用へ--. 京都大学プレスリリース. 2023-06-13.Nonalcoholic steatohepatitis (NASH) can lead to cirrhosis and hepatocellular carcinoma in their advanced stages; however, there are currently no approved therapies. Here, we show that microRNA (miR)-33b in hepatocytes is critical for the development of NASH. miR-33b is located in the intron of sterol regulatory element–binding transcription factor 1 and is abundantly expressed in humans, but absent in rodents. miR-33b knock-in (KI) mice, which have a miR-33b sequence in the same intron of sterol regulatory element–binding transcription factor 1 as humans and express miR-33b similar to humans, exhibit NASH under high-fat diet feeding. This condition is ameliorated by hepatocyte-specific miR-33b deficiency but unaffected by macrophage-specific miR-33b deficiency. Anti-miR-33b oligonucleotide improves the phenotype of NASH in miR-33b KI mice fed a Gubra Amylin NASH diet, which induces miR-33b and worsens NASH more than a high-fat diet. Anti-miR-33b treatment reduces hepatic free cholesterol and triglyceride accumulation through up-regulation of the lipid metabolism–related target genes. Furthermore, it decreases the expression of fibrosis marker genes in cultured hepatic stellate cells. Thus, inhibition of miR-33b using nucleic acid medicine is a promising treatment for NASH
MiR-33a is a therapeutic target in SPG4-related hereditary spastic paraplegia human neurons
Recent reports, including ours, have indicated that microRNA (miR)-33 located within the intron of sterol regulatory element binding protein (SREBP) 2 controls cholesterol homeostasis and can be a potential therapeutic target for the treatment of atherosclerosis. Here, we show that SPAST, which encodes a microtubule-severing protein called SPASTIN, was a novel target gene of miR-33 in human. Actually, the miR-33 binding site in the SPAST 3′-UTR is conserved not in mice but in mid to large mammals, and it is impossible to clarify the role of miR-33 on SPAST in mice. We demonstrated that inhibition of miR-33a, a major form of miR-33 in human neurons, via locked nucleic acid (LNA)-anti-miR ameliorated the pathological phenotype in hereditary spastic paraplegia (HSP)-SPG4 patient induced pluripotent stem cell (iPSC)-derived cortical neurons. Thus, miR-33a can be a potential therapeutic target for the treatment of HSP-SPG4
microRNA-33 maintains adaptive thermogenesis via enhanced sympathetic nerve activity
褐色脂肪細胞の燃焼を促す新たなメカニズムを解明 --体の熱産生にマイクロRNA-33が関与--. 京都大学プレスリリース. 2021-02-17.Adaptive thermogenesis is essential for survival, and therefore is tightly regulated by a central neural circuit. Here, we show that microRNA (miR)-33 in the brain is indispensable for adaptive thermogenesis. Cold stress increases miR-33 levels in the hypothalamus and miR-33−/− mice are unable to maintain body temperature in cold environments due to reduced sympathetic nerve activity and impaired brown adipose tissue (BAT) thermogenesis. Analysis of miR-33f/f dopamine-β-hydroxylase (DBH)-Cre mice indicates the importance of miR-33 in Dbh-positive cells. Mechanistically, miR-33 deficiency upregulates gamma-aminobutyric acid (GABA)A receptor subunit genes such as Gabrb2 and Gabra4. Knock-down of these genes in Dbh-positive neurons rescues the impaired cold-induced thermogenesis in miR-33f/f DBH-Cre mice. Conversely, increased gene dosage of miR-33 in mice enhances thermogenesis. Thus, miR-33 in the brain contributes to maintenance of BAT thermogenesis and whole-body metabolism via enhanced sympathetic nerve tone through suppressing GABAergic inhibitory neurotransmission. This miR-33-mediated neural mechanism may serve as a physiological adaptive defense mechanism for several stresses including cold stress
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