31 research outputs found
Recovery from heat shock injury by activation of Na+-glucose cotransporter in renal epithelial cells
AbstractExposure of cells or organs to sublethal physical or chemical stresses induces disruption of cellular structures and functions. Here, we examined whether Na+-glucose cotransporter (SGLT1) is involved in the recovery from heat shock (HS) injury in porcine renal epithelial LLC-PK1 cells. Recovery from HS (42 °C for 3 h, then 37 °C for 12 h) increased SGLT1 activity, assessed by [14C]α-methyl glucopyranoside uptake, and a maximal transport rate (Vmax) from 2.4 to 5.9 nmol/mg protein/30 min, but did not alter an apparent affinity constant (Km). Protein distribution of SGLT1 in apical membrane fraction was also increased after recovery from HS without changing in total membrane fraction. Membrane integrity assessed by calcein accumulation was decreased by HS, and then returned to basal level. This recovery was inhibited by phloridzin, a potent SGLT1 inhibitor, and nonmetabolizable glucose analogues. Anti-transforming growth factor-β1 (TGF-β1) antibody inhibited both elevation of SGLT1 distribution in apical membrane and recovery of calcein accumulation induced by HS. Taken together, HS increases in the number of SGLT1 protein in apical membrane mediated via TGF-β1 signaling pathway. The increase of glucose uptake is necessary to repair plasma membrane integrity
BioHackathon series in 2011 and 2012: penetration of ontology and linked data in life science domains
The application of semantic technologies to the integration of biological data and the interoperability of bioinformatics analysis and visualization tools has been the common theme of a series of annual BioHackathons hosted in Japan for the past five years. Here we provide a review of the activities and outcomes from the BioHackathons held in 2011 in Kyoto and 2012 in Toyama. In order to efficiently implement semantic technologies in the life sciences, participants formed various sub-groups and worked on the following topics: Resource Description Framework (RDF) models for specific domains, text mining of the literature, ontology development, essential metadata for biological databases, platforms to enable efficient Semantic Web technology development and interoperability, and the development of applications for Semantic Web data. In this review, we briefly introduce the themes covered by these sub-groups. The observations made, conclusions drawn, and software development projects that emerged from these activities are discussed
Hitomi (ASTRO-H) X-ray Astronomy Satellite
The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E > 2 keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft x-rays to gamma rays. After a successful launch on February 17, 2016, the spacecraft lost its function on March 26, 2016, but the commissioning phase for about a month provided valuable information on the onboard instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month
ATP release via anion channels
ATP serves not only as an energy source for all cell types but as an ‘extracellular messenger-for autocrine and paracrine signalling. It is released from the cell via several different purinergic signal efflux pathways. ATP and its Mg2+ and/or H+ salts exist in anionic forms at physiological pH and may exit cells via some anion channel if the pore physically permits this. In this review we survey experimental data providing evidence for and against the release of ATP through anion channels. CFTR has long been considered a probable pathway for ATP release in airway epithelium and other types of cells expressing this protein, although non-CFTR ATP currents have also been observed. Volume-sensitive outwardly rectifying (VSOR) chloride channels are found in virtually all cell types and can physically accommodate or even permeate ATP4- in certain experimental conditions. However, pharmacological studies are controversial and argue against the actual involvement of the VSOR channel in significant release of ATP. A large-conductance anion channel whose open probability exhibits a bell-shaped voltage dependence is also ubiquitously expressed and represents a putative pathway for ATP release. This channel, called a maxi-anion channel, has a wide nanoscopic pore suitable for nucleotide transport and possesses an ATP-binding site in the middle of the pore lumen to facilitate the passage of the nucleotide. The maxi-anion channel conducts ATP and displays a pharmacological profile similar to that of ATP release in response to osmotic, ischemic, hypoxic and salt stresses. The relation of some other channels and transporters to the regulated release of ATP is also discussed
Effects of Egg White Protein Supplementation on Muscle Strength and Serum Free Amino Acid Concentrations
The aim of this study was to evaluate the effects of egg white protein compared to carbohydrate intake prior to exercise on fat free mass (FFM), one repetition maximum (1RM) muscle strength and blood biochemistry in female athletes. Thirty healthy female collegiate athletes were recruited for this study and matched by sport type, body fat percentage and 1RM leg curl muscle strength. Participants were randomly divided into two groups: protein group (15.0 g egg white protein; 75 kcal) and carbohydrate group (17.5 g maltodextrin, 78 kcal). Supplements were administered daily at the same time in a double-blind manner prior to training during an 8-week period. Measurements were performed before and after the 8-week regimen. The mean dietary energy intake did not change throughout the study period. FFM and 1RM assessments (i.e., leg curl, leg extension, squat, and bench press) increased in both groups. Furthermore, serum urea and serum citrulline levels after the 8-week regimen increased significantly only in the protein group. Our findings indicated that compared to the carbohydrate supplement, the protein supplement was associated with some changes in protein metabolites but not with changes in body composition or muscle strength
Life-threatening airway obstruction due to upper airway edema and marked neck swelling after labor and delivery
Background and objectives: Airway changes generally occur in normal gravidas; however, these changes could cause critical situations in specific populations. Objectives: This article presents the case of a difficult airway patient that went into shock because of atonic bleeding after vaginal delivery for stillbirth. Case report: A 32-yr-old woman with atonic bleeding after vaginal delivery for stillbirth was transferred to our hospital. She manifested shock, and her respiratory condition was progressively deteriorating. Airway obstruction caused by neck swelling and pharyngolaryngeal edema was apparent. We tried tracheal intubation using direct and indirect laryngoscopes. However, it turned out that insertion of the laryngoscopic devices to the oral cavity was impossible. After several attempts using the Trachlight™, successful intubation was finally made. After hysterectomy, she was admitted to the intensive care unit (ICU) and treated for five days. At discharge from the ICU, her Mallampati score was I-II. Her body weight decreased 60 kg to 51 kg during ICU stay. Conclusions: We believe that concomitant attacks of labor and delivery and fluid resuscitation probably worsened upper airway and neck edema enough to cause acute airway obstruction and difficult laryngoscopy. Keywords: Labor and delivery, Difficult airway, Airway edem
Obstrução das vias aéreas com risco para a vida, causada por edema de via aérea superior e inchaço cervical significativo depois do trabalho de parto/parto
EXPERIÊNCIA E OBJETIVOS: Em geral, alterações nas vias aéreas ocorrem em grávidas normais; no entanto, essas alterações podem gerar situações críticas em populações específicas. OBJETIVOS: Esse artigo apresenta o caso de uma paciente que entrou em choque por causa de sangramento atônico em seguida a parto vaginal de natimorto. RELATO DE CASO: Mulher com 32 anos com sangramento atônico em seguida a parto vaginal de natimorto foi transferida para nosso hospital. A paciente manifestou choque e seu estado respiratório estava em progressiva deterioração. Ficou evidenciada obstrução das vias aéreas causada por inchaço cervical e edema faringolaríngeo. Tentamos intubação traqueal utilizando laringoscopia direta e indireta. No entanto, não foi possível inserir qualquer dos dispositivos de laringoscopia tentados. Depois de várias tentativas com TrachlightTM, finalmente obtivemos sucesso com a intubação. Depois da histerectomia, a paciente foi internada na unidade de terapia intensiva (UTI), onde ficou em tratamento durante cinco dias. Ao receber alta da UTI, tinha escore de Mallampati I-II. Durante sua estadia na UTI, seu peso diminuiu de 60 kg para 51 kg. CONCLUSÕES: É provável que episódios simultâneos de trabalho de parto/parto e de ressuscitação com fluidos pioraram suficientemente o edema de via aérea e o inchaço cervical a ponto de causar obstrução aguda das vias aéreas e dificuldade na laringoscopia
Clinical Efficacy of Bepridil for Class I Antiarrhythmic Drug-Induced Atrial Flutter in Patients with Paroxysmal Atrial Fibrillation
Background: Class I antiarrhythmic drugs can promote the organization of atrial fibrillation (AF) and sometimes converts AF into atrial flutter (AFL) concomitant with difficulty of rate control. We studied the usefulness of Bepridil, which exhibits a class III-like effect, for class I drug-induced AFL in patients with paroxysmal AF.
Methods: The study population consisted of 17 consecutive patients (15 men, mean age 65 ± 8 years) with AFL converted from paroxysmal AF following oral treatment of class IA or IC antiarrhythmic agents including pilsicainide (n = 8), cibenzoline (n = 5), flecainide (n = 2), aprindine (n = 1), and propafenone with cibenzoline (n = 1). After the occurrence of AFL, class I drug was replaced by bepridil with a dose of 100–200 mg per day in all patients.
Results: After the treatment with bepridil, 15 (88%) out of the 17 patients restored sinus rhythm after 1 to 68 days (average of 21 days). In 12 (80%) of the 15 patients, sinus rhythm was maintained for an average of 23.6 months (range of 1 to 62 months) follow-up period. Although torsade de pointes was not recognized, a marked QT prolongation (0.60 sec) was observed in one patient during the administration of bepridil at a daily dose of 200 mg. In this patient, QT interval was normalized (0.45 sec) after reduction of bepridil to 150 mg daily.
Conclusion: Bepridil treatment may be safe and effective for class I drug-induced AFL in patients with paroxysmal AF to restore and maintain sinus rhythm as an alternative therapy for catheter ablation. However, the QT interval must be carefully monitored during this medication