788 research outputs found
Pioglitazone in Nonalcoholic Steatohepatitis
金沢大学医薬保健研究域医学
HLA-Haploidentical Peripheral Blood Stem Cell Transplantation with Post-Transplant Cyclophosphamide after Busulfan-Containing Reduced-Intensity Conditioning
AbstractAllogeneic hematopoietic stem cell transplantation (allo-SCT) using post-transplant cyclophosphamide (PTCy) is increasingly performed. We conducted a multicenter phase II study to evaluate the safety and efficacy of PTCy-based HLA-haploidentical peripheral blood stem cell transplantation (PTCy-haploPBSCT) after busulfan-containing reduced-intensity conditioning. Thirty-one patients were enrolled; 61% patients were not in remission and 42% patients had a history of prior allo-SCT. Neutrophil engraftment was achieved in 87% patients with a median of 19 days. The cumulative incidence of grades II to IV and III to IV acute graft-versus-host disease (GVHD) and chronic GVHD at 1 year were 23%, 3%, and 15%, respectively. No patients developed severe chronic GVHD. Day 100 nonrelapse mortality (NRM) rate was 19.4%. Overall survival, relapse, and disease-free survival rates were 45%, 45%, and 34%, respectively, at 1 year. Subgroup analysis showed that patients who had a history of prior allo-SCT had lower engraftment, higher NRM, and lower overall survival than those not receiving a prior allo-SCT. Our results suggest that PTCy-haploPBSCT after busulfan-containing reduced-intensity conditioning achieved low incidences of acute and chronic GVHD and NRM and stable donor engraftment and low NRM, particularly in patients without a history of prior allo-SCT
Isotopic evidence for the spatial heterogeneity of the planktonic food webs in the transition zone between river and lake ecosystems
Resources and organisms in food webs are distributed patchily. The spatial structure of food webs is important and critical to understanding their overall structure. However, there is little available information about the small-scale spatial structure of food webs. We investigated the spatial structure of food webs in a lake ecosystem at the littoral transition zone between an inflowing river and a lake. We measured the carbon isotope ratios of zooplankton and particulate organic matter (POM; predominantly phytoplankton) in the littoral zone of a saline lake. Parallel changes in the δ 13C values of zooplankton and their respective POMs indicated that there is spatial heterogeneity of the food web in this study area. Lake ecosystems are usually classified at the landscape level as either pelagic or littoral habitats. However, we showed small-scale spatial heterogeneity among planktonic food webs along an environmental gradient. Stable isotope data is useful for detecting spatial heterogeneity of habitats, populations, communities, and ecosystems
Helicobacter pylori-Negative Primary Rectal MALT Lymphoma: Complete Remission after Radiotherapy
Rectal mucosa-associated lymphoid tissue (MALT) lymphoma is a rare condition. Although the majority of patients undergo surgical resection, a definitive treatment for rectal MALT lymphoma has not yet been established. In the present study, we report the outcome of radiotherapy in 3 patients with rectal MALT lymphoma. Our cohort ranged from 56 to 65 years of age. The male/female ratio was 1:2, and all patients were in stage I (Lugano classification) of the disease. Endoscopic findings revealed elevated lesions resembling submucosal tumors in 2 patients, and a sessile elevated lesion with a nodular surface in 1 patient. One of the 3 patients underwent magnifying endoscopy with crystal violet staining that demonstrated a type I pit pattern (Kudo's classification) lesion with a broad intervening area caused by the upthrust of the tumor from the submucosa. All patients tolerated radiotherapy at doses of 30 Gy without major complications and achieved complete remission. Follow-up ranged from 13 to 75 months (mean 51.0 months), revealing no recurrence of MALT lymphoma. As such, we propose radiotherapy to be a safe and effective means for treating rectal MALT lymphoma
Tumor necrosis factor-α-induced production of plasminogen activator inhibitor 1 and its regulation by pioglitazone and cerivastatin in a nonmalignant human hepatocyte cell line
金沢大学大学院医学系研究科環境社会医学Plasminogen activator inhibitor 1 (PAI-1) is an important mediator of atherosclerosis and liver fibrosis in insulin resistance. Circulating levels of PAI-1 are elevated in obese individuals, and PAI-1 messenger RNA is significantly higher in the livers of obese type 2 diabetic individuals than in nonobese type 2 diabetic individuals. To address the mechanism underlying the up-regulation of hepatic PAI-1 in obesity, we tested the effects of tumor necrosis factor α (TNF-α), an important link between obesity and insulin resistance, on PAI-1 production in the nonmalignant human hepatocyte cell line, THLE-5b. Incubation of THLE-5b cells with TNF-α stimulated PAI-1 production via protein kinase C-, mitogen-activated protein kinase-, protein tyrosine kinase-, and nuclear factor-κB-dependent pathways. A thiazolidinedione, pioglitazone, reduced TNF-α-induced PAI-1 production by 32%, via protein kinase C- and nuclear factor-κB-dependent pathways. The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor cerivastatin inhibited TNF-α-induced PAI-1 production by 59%, which was reversed by coincubation with mevalonic acid. In conclusion, obesity and TNF-α up-regulation of PAI-1 expression in human hepatocytes may contribute to the impairment of the fibrinolytic system, leading to the development of atherosclerosis and liver fibrosis in insulin-resistant individuals. A thiazolidinedione and a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor may thus be candidate drugs to inhibit obesity-associated hepatic PAI-1 production. © 200
Natural Variation in the Flag Leaf Morphology of Rice Due to a Mutation of the NARROW LEAF 1 Gene in Oryza sativa L.
We investigated the natural variations in the flag leaf morphology of rice. We conducted a principal component analysis based on nine flag leaf morphology traits using 103 accessions from the National Institute of Agrobiological Sciences Core Collection. The first component explained 39% of total variance, and the variable with highest loading was the width of the flag leaf (WFL). A genome-wide association analysis of 102 diverse Japanese accessions revealed that marker RM6992 on chromosome 4 was highly associated with WFL. In analyses of progenies derived from a cross between Takanari and Akenohoshi, the most significant quantitative trait locus (QTL) for WFL was in a 10.3-kb region containing the NARROW LEAF 1 (NAL1) gene, located 0.4 Mb downstream of RM6992. Analyses of chromosomal segment substitution lines indicated that a mutation (G1509A single-nucleotide mutation, causing an R233H amino acid substitution in NAL1) was present at the QTL. This explained 13 and 20% of total variability in WFL and the distance between small vascular bundles, respectively. The mutation apparently occurred during rice domestication and spread into japonica, tropical japonica, and indica subgroups. Notably, one accession, Phulba, had a NAL1 allele encoding only the N-terminal, or one-fourth, of the wild-type peptide. Given that the Phulba allele and the histidine-type allele showed essentially the same phenotype, the histidine-type allele was regarded as malfunctional. The phenotypes of transgenic plants varied depending on the ratio of histidine-type alleles to arginine-type alleles, raising the possibility that H(233)-type products function differently from and compete with R(233)-type products
Structures and mechanisms of actin ATP hydrolysis
The major cytoskeleton protein actin undergoes cyclic transitions between the monomeric G-form and the filamentous F-form, which drive organelle transport and cell motility. This mechanical work is driven by the ATPase activity at the catalytic site in the F-form. For deeper understanding of the actin cellular functions, the reaction mechanism must be elucidated. Here, we show that a single actin molecule is trapped in the F-form by fragmin domain-1 binding and present their crystal structures in the ATP analog-, ADP-Pi-, and ADP-bound forms, at 1.15-Å resolutions. The G-to-F conformational transition shifts the side chains of Gln137 and His161, which relocate four water molecules including W1 (attacking water) and W2 (helping water) to facilitate the hydrolysis. By applying quantum mechanics/molecular mechanics calculations to the structures, we have revealed a consistent and comprehensive reaction path of ATP hydrolysis by the F-form actin. The reaction path consists of four steps: 1) W1 and W2 rotations; 2) PG–O3B bond cleavage; 3) four concomitant events: W1–PO3− formation, OH− and proton cleavage, nucleophilic attack by the OH− against PG, and the abstracted proton transfer; and 4) proton relocation that stabilizes the ADP-Pi–bound F-form actin. The mechanism explains the slow rate of ATP hydrolysis by actin and the irreversibility of the hydrolysis reaction. While the catalytic strategy of actin ATP hydrolysis is essentially the same as those of motor proteins like myosin, the process after the hydrolysis is distinct and discussed in terms of Pi release, F-form destabilization, and global conformational changes
Astaxanthin prevents and reverses diet-induced insulin resistance and steatohepatitis in mice: A comparison with Vitamin E
Hepatic insulin resistance and nonalcoholic steatohepatitis (NASH) could be caused by excessive hepatic lipid accumulation and peroxidation. Vitamin E has become a standard treatment for NASH. However, astaxanthin, an antioxidant carotenoid, inhibits lipid peroxidation more potently than Vitamin E. Here, we compared the effects of astaxanthin and Vitamin E in NASH. We first demonstrated that astaxanthin ameliorated hepatic steatosis in both genetically (ob/ob) and high-fat-diet-induced obese mice. In a lipotoxic model of NASH: mice fed a high-cholesterol and high-fat diet, astaxanthin alleviated excessive hepatic lipid accumulation and peroxidation, increased the proportion of M1-type macrophages/Kupffer cells, and activated stellate cells to improve hepatic inflammation and fibrosis. Moreover, astaxanthin caused an M2-dominant shift in macrophages/Kupffer cells and a subsequent reduction in CD4+ and CD8+ T cell recruitment in the liver, which contributed to improved insulin resistance and hepatic inflammation. Importantly, astaxanthin reversed insulin resistance, as well as hepatic inflammation and fibrosis, in pre-existing NASH. Overall, astaxanthin was more effective at both preventing and treating NASH compared with Vitamin E in mice. Furthermore, astaxanthin improved hepatic steatosis and tended to ameliorate the progression of NASH in biopsy-proven human subjects. These results suggest that astaxanthin might be a novel and promising treatment for NASH
Photon-counting CT: technical features and clinical impact on abdominal imaging
The version of record of this article, first published in Abdominal Radiology, is available online at Publisher’s website: https://doi.org/10.1007/s00261-024-04414-5.Photon-counting CT has a completely different detector mechanism than conventional energy-integrating CT. In the photon-counting detector, X-rays are directly converted into electrons and received as electrical signals. Photon-counting CT provides virtual monochromatic images with a high contrast-to-noise ratio for abdominal CT imaging and may improve the ability to visualize small or low-contrast lesions. In addition, photon-counting CT may offer the possibility of reducing radiation dose. This review provides an overview of the actual clinical operation of photon-counting CT and its diagnostic utility in abdominal imaging. We also describe the clinical implications of photon-counting CT including imaging of hepatocellular carcinoma, liver metastases, hepatic steatosis, pancreatic cancer, intraductal mucinous neoplasm of the pancreas, and thrombus
Liver steatosis, but not fibrosis, is associated with insulin resistance in nonalcoholic fatty liver disease
金子, 周一金沢大学大学院医学系研究科環境社会医学Background: To address the hypothesis that liver steatosis causes systemic insulin resistance, we sought to determine the liver histological feature that most strongly contributes to insulin resistance in patients with nonalcoholic fatty liver disease (NAFLD). Methods: Liver biopsy specimens were obtained from 131 patients with clinically suspected NAFLD. The stage, grade of nonalcoholic steatohepatitis (NASH), and level of steatosis were scored and analyzed in relation to the homeostasis model assessment of insulin resistance (HOMA-IR) and the metabolic clearance rate (MCR), measured using the glucose clamp method. Results: In the univariate analysis, the degree of hepatic steatosis (r = 0.458, P < 0.001), stage (r = 0.360, P < 0.001), and grade (r = 0.349, P < 0.01) of NASH were significantly correlated with the HOMA-IR. Multiple regression analysis adjusting for age, sex, body mass index, and each histological score showed that steatosis was significantly and independently associated with HOMA-IR (coefficient = 1.42, P < 0.001), but not with the stage (coefficient = 0.33, P = 0.307) or grade (coefficient = 0.67, P = 0.134) of NASH. Similar independent relationships were observed between steatosis and MCR, but the relationship was weaker (coefficient = -0.98, P = 0.076). Conclusions: Steatosis of the liver, but not the stage or the grade of NASH, is associated with insulin resistance in patients with NAFLD. © Springer-Verlag Tokyo 2007
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