288 research outputs found
Meeting at the Crossroad: The Relationship of English Language Proficiency, Perfectionism, Length of Stay with Self-esteem among Non-native English-speaking International Students
Educational Psycholog
Control of the incorporation and release of guest molecules by photodimerization in liposomes
In a drug-delivery system using liposomes, the use of guest molecules bearing hydrophilic moieties results in some leakage from lipid membranes. We suppressed the leakage of coumarins (used as model guest molecules in a drug-delivery system) from lipid membranes by photodimerization at 365 nm. The reason for this phenomenon could be ascribed to an increase in the hydrophobicity of the dimers of the coumarins. The formation of the dimers was detected by 1H NMR, UV-vis absorption, and mass spectra and the leakage percentages of the coumarins were determined by 1H NMR spectra based on the peak intensities. In contrast, when the dimer reverted to a monomer by ultraviolet (254 nm) irradiation, the resulting monomer was released from liposomes.This work was supported by a JSPS KAKENHI Grant-in-Aid for Scientific Research (B) (Grant No. JP16H04133) and a Grant-in-Aid for Challenging Exploratory Research (Grant No. JP16K13982)
Incorporation of large guest molecules into liposomes via chemical reactions in lipid membranes
The incorporation of hydrophobic guest molecules into lipid membranes by the exchange of the guest molecule from a cyclodextrin (CDx) complex to a liposome is limited to guest molecules that can be included in CDxs. To solve this problem, large guest molecules were incorporated into liposomes by chemical reactions of guest molecules in lipid membranes. Stable lipid-membrane-incorporated fullerene derivatives with large substituent(s) were prepared by Diels–Alder reactions in lipid membranes.Electronic supplementary information (ESI) available: Schematic representation of the premixing and exchange methods, 1H NMR spectra and UV-vis absorption spectra. See DOI: 10.1039/c6ob02343fThis work was supported by the Japanese Society for the Promotion of Science (JSPS) KAKENHI Grant-in-Aid for Scientific Research (B) (Grant No. JP16H04133) and a Grant-in-Aid for Challenging Exploratory Research (Grant No. JP16K13982)
Repeated Pancreatectomy for Recurrent Pancreatic Carcinoma after Pylorus-Preserving Pancreatoduodenectomy: Report of Two Patients
Repeated pancreatectomy for pancreatic carcinoma is extremely rare. We report two such patients who underwent pancreatectomy for carcinoma developing in the pancreatic remnant after pylorus-preserving pancreatoduodenectomy (PpPD) for invasive pancreatic ductal carcinoma. One patient underwent PpPD for invasive pancreatic ductal carcinoma and received adjuvant chemotherapy. Follow-up computed tomography (CT) demonstrated a low-density mass in the remnant pancreas, which was diagnosed as a carcinoma by endoscopic ultrasound-guided fine-needle aspiration cytology 5 years 10 months after PpPD. She underwent curative resection of the remnant pancreas and is alive and well 13 months after the second operation. The other patient underwent PpPD for invasive pancreatic ductal carcinoma. Follow-up CT showed a low-density mass in the remnant pancreas after 2 years 11 months. He received systemic chemotherapy with S-1 for 3 months. The tumor shrank, and the patient underwent curative resection of the remnant pancreas 3 years 1 month after the initial operation. Repeated pancreatectomy may provide a chance of long survival for patients with carcinoma developing in the remnant pancreas after pancreatectomy if the recurrence occurring at long term is limited to the remnant pancreas
Prevalence and clinical manifestations of gastro-oesophageal reflux-associated chronic cough in the Japanese population
Gastro-oesophageal reflux (GOR) is one of the most common causes of chronic cough in Western countries, responsible for 10 to 40% of cases. In Japan, however, GOR-associated chronic cough (GOR-CC) has been rarely reported and its clinical manifestation including frequency of concomitant reflux laryngitis is poorly known. We have analyzed prevalence and clinical characteristics of patients who were diagnosed as having GOR-CC among adult patients with chronic cough (≥ 8 weeks) who visited our asthma and cough clinic over a period of 19 months. Diagnosis of GOR-CC was based on the response of coughing to a proton-pump inhibitor (lansoprazole™) and/or positive results of 24 h ambulatory esophageal pH monitoring. Laryngeal involvement was based on symptoms or objective diagnosis by specialists. GOR-associated chronic cough was diagnosed in 7.1% (8 of 112) of chronic cough patients. In addition to the demographic data which were consistent with the characteristics of patients with GOR-CC in the Western populations, including gender (6 females), age (mean ± SE, 56.9 ± 5.8 years), duration of cough (9.9 ± 3.3 months), lack of gastrointestinal symptoms (3 of 8) and complication with other causes of cough (5 of 8), we found the standard range of body mass index (23.9 ± 1.5 kg/m(2)) and high incidence of concomitant reflux laryngitis (5 of 8) in the present 8 patients. Among 4 patients who could stop treatment with temporal resolution of cough, cough recurred in 3 patients, 1 week to 8 months after the discontinuation. In conclusion, GOR-CC is a less frequent cause of chronic cough in Japan than in Western countries. Signs or symptoms of laryngitis may be important as clues to suspicion of GOR-CC
Pravastatin restored the infarct size-limiting effect of ischemic preconditioning blunted by hypercholesterolemia in the rabbit model of myocardial infarction
AbstractOBJECTIVESWe tested to find out whether pravastatin restores the infarct size (IS)-limiting effect of ischemic preconditioning (IP) and if it has any effect on the IP-induced activation of adenosine producing enzyme ecto-5′-nucleotidase which plays a key role in the IP-induced cardioprotection.BACKGROUNDThe IS-limiting effect of IP is blunted by hypercholesterolemia. Recently, HMG-CoA reductase inhibitors are shown to have direct cytoprotective effects.METHODSRabbits were fed with a normal or cholesterol (1%) added diet with or without pravastatin (5 mg/kg/day) treatment. Infarct size was measured after 30 min occlusion and 3 h reperfusion of circumflex coronary artery with or without the IP procedure (5 min occlusion and 10 min reperfusion). Additionally, ecto-5′-nucleotidase activities of ischemic and nonischemic myocardium were measured immediately after IP procedure.RESULTSThis dose of pravastatin did not normalize the increased level of serum cholesterol. The IS-limiting effect of preceding IP (IS reduced from 36.7% to 9.6%, p < 0.001) was abolished by hypercholesterolemia (from 46.1% to 31.3%, p = NS) and restored by pravastatin treatment (from 35.2% to 9.4%, p < 0.001). Pravastatin treatment did not affect IS or the effect of IP under normocholesterolemia. The activation of ecto-5′-nucleotidase presented as the activity ratio of ischemic to nonischemic myocardium (3.1-fold in normocholesterolemia) was blunted by hypercholesterolemia (1.8-fold, p < 0.05) and restored by pravastatin treatment (2.9-fold).CONCLUSIONSPravastatin, at the dose serum cholesterol was not normalized, restored the IS-limiting effect of IP and IP-induced ecto-5′-nucleotidase activation, which were both blunted by hypercholesterolemia. The activation of ecto-5′-nucleotidase may be worth further investigation as a possible mechanism for the hypercholesterolemia-induced retardation and pravastatin-mediated restoration of the cardioprotective effect of IP
Experimental gold nephropathy in guinea pigs: Detection of autoantibodies to renal tubular antigens
Experimental gold nephropathy in guinea pigs: Detection of autoantibodies to renal tubular antigens. Renal tubular dysfunction was induced in Hartley guinea pigs by injection of sodium aurothiomalate (gold) as manifested by excretion of tubular basement membrane (TBM) antigen and renal tubular epithelial (RTE) antigen in urine and tubular proteinuria. Following the tubular dysfunction, autoimmune tubulointerstitial nephritis (TIN) and/or immune complex nephropathy (ICN) developed in a large proportion of animals. TIN was associated with anti-TBM antibodies, and the histological features were characterized by tubular lesions with interstitial mononuclear cell infiltration, destruction of tubules, and interstitial fibrosis. In ICN, the glomerular lesions consisted of partial thickening of capillary walls and mesangial cellularity, and granular immune deposits were seen in the mesangial area and on capillary walls. Furthermore, electron-dense deposits were demonstrated in the mesangial area and in the glomerular basement membrane (GBM) by electron microscopy. Anti-RTE antibodies were detected in the sera and eluates from the kidney of animals with ICN. RTE antigens were also detected in the glomerular deposits by indirect immunofluorescence using anti-guinea pig RTE antibody. These results suggest that TBM and RTE antigens released from renal tubules damaged by a direct toxic action of gold may lead to antibody formation against these antigens and induce TIN and/or ICN
Features of cough variant asthma and classic asthma during methacholine-induced brochoconstriction: a cross-sectional study
[Background]Little is known regarding mechanistic and phenotypic differences between cough variant asthma (CVA), presenting with a chronic cough as the sole symptom that responds to bronchodilators, and classic asthma with wheezing during methacholine inhalation. Here we reported airway sensitivity, airway reactivity, and as the main concern, the appearance of cough and wheezes during methacholine inhalation in patients with CVA or classic asthma. [Methods]We cross-sectionally examined the degrees of airway sensitivity, the point where resistance started to increase, and reactivity, the slope of the methacholine-resistance curve, and the appearance of cough and wheezes in steroid-naive adult patients with classic asthma (n = 58) or CVA (n = 55) while they were continuously inhaling methacholine during simultaneous measurement of respiratory resistance. [Results]Patients with CVA were less sensitive and less reactive to inhaled methacholine and wheezed less frequently but coughed more frequently during methacholine-induced bronchoconstriction than did patients with classic asthma. Multivariate analysis revealed that airway hypersensitivity and lower baseline FEV1/FVC were associated with the appearance of wheezes, whereas a diagnosis of CVA was associated with coughing. [Conclusion]There are mechanistic and phenotypic differences between CVA and classic asthma during methacholine inhalation. Frequent coughing during bronchoconstriction may be a distinctive feature of CVA
Formation of lipid membrane‐incorporated small π‐molecules bearing hydrophilic groups
Nineteen poorly water‐soluble π‐conjugated molecules were evaluated in terms of their ability to be stably incorporated into lipid membranes. The resulting lipid membrane-incorporated π‐conjugated guest molecules (LMIGs) were classified into four categories, including (i) those that formed stable LMIGs; (ii) those where some of guest molecules precipitated; (iii) those that formed small self‐aggregates consisting of lipids and/or guest molecules; and (iv) those that leaked some of the guest molecules into the bulk water. Compounds belonging to category (ii) were confirmed by UV‐vis absorption analysis. In contrast, compounds belonging to categories (i), (iii) and (iv) were discriminated based on their 1H NMR spectra and the broadening or disappearance of the peaks of the guest molecules and the lipids in LMIGs and large liposomes. Several LMIGs could be converted from one category to another using other lipids. Furthermore, the guest molecules belonging to category (iv) were successfully predicted using the octanol‐water partition coefficient, which was calculated by simulation.This work was supported by the Japanese Society for the Promotion of Science (JSPS) KAKENHI Grant‐in‐Aid for Scientific Research (B) (Grant No. JP16H04133) and a Grant‐in‐Aid for Challenging Exploratory Research (Grant No. JP16K13982)
Lipid-membrane-incorporated arylboronate esters as agents for boron neutron capture therapy
Arylboronate esters bearing methyl groups in both of their ortho positions were stably incorporated into lipid membranes at high concentrations without undergoing hydrolysis to the corresponding boronic acids. This method could be used in combination with previous methods to increase the maximum ratio of boron atoms in liposomal boron carriers.This work was supported by a JSPS KAKENHI Grant-in-Aid for Scientific Research (B) (Grant No. JP16H04133) and a Grant-in-Aid for Challenging Exploratory Research (Grant No. JP16K13982)
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