48 research outputs found
Kinetics and protective role of autophagy in a mouse cecal ligation and puncture-induced sepsis
INTRODUCTION: It is not well understood whether the process of autophagy is accelerated or blocked in sepsis, and whether it is beneficial or harmful to the immune defense mechanism over a time course during sepsis. Our aim was to determine both the kinetics and the role of autophagy in sepsis. METHODS: We examined autophagosome and autolysosome formation in a cecal ligation and puncture (CLP) mouse model of sepsis (in C57BL/6N mice and GFP-LC3 transgenic mice), using western blotting, immunofluorescence, and electron microscopy. We also investigated the effect of chloroquine inhibition of autophagy on these processes. RESULTS: Autophagy, as demonstrated by increased LC3-II/LC3-I ratios, is induced in the liver, heart, and spleen over 24 h after CLP. In the liver, autophagosome formation peaks at 6 h and declines by 24 h. Immunofluorescent localization of GFP-LC3 dots (alone and with lysosome-associated membrane protein type 1 (LAMP1)), as well as electron microscopic examination, demonstrate that both autophagosomes and autolysosomes are increased after CLP, suggesting that intact autophagy mechanisms operate in the liver in this model. Furthermore, inhibition of autophagy process by chloroquine administration immediately after CLP resulted in elevated serum transaminase levels and a significant increase in mortality. CONCLUSIONS: All autophagy-related processes are properly activated in the liver in a mouse model of sepsis; autophagy appears to play a protective role in septic animals
Trends in template/fragment-free protein structure prediction
Predicting the structure of a protein from its amino acid sequence is a long-standing unsolved problem in computational biology. Its solution would be of both fundamental and practical importance as the gap between the number of known sequences and the number of experimentally solved structures widens rapidly. Currently, the most successful approaches are based on fragment/template reassembly. Lacking progress in template-free structure prediction calls for novel ideas and approaches. This article reviews trends in the development of physical and specific knowledge-based energy functions as well as sampling techniques for fragment-free structure prediction. Recent physical- and knowledge-based studies demonstrated that it is possible to sample and predict highly accurate protein structures without borrowing native fragments from known protein structures. These emerging approaches with fully flexible sampling have the potential to move the field forward
Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial
Background: The EMPA KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population. Methods: EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110. Findings: Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5–2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62–0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16–1·59), representing a 50% (42–58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1). Interpretation: In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease. Funding: Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council
Systematic review: brain metastases from colorectal cancer—Incidence and patient characteristics
Monitoring of cutting process in end milling of hard and brittle materials
Glass materials have been widely used in optical components in recent years. The purpose of this study was to develop an effective method for real-time detection of the state of cutting tools used in end milling of hard brittle materials. Cutting tests were performed to identify parameters that are useful in monitoring micro tool wear in glass milling. A specific component of the cutting force was found to be related to the progression of tool wear. Furthermore, using fast Fourier transform (FFT) analysis, the peak amplitudes of the cutting forces were found to occur at a specific frequency
Suppression of Mammary Carcinoma Growth \u3cem\u3ein vitro\u3c/em\u3e and \u3cem\u3ein vivo\u3c/em\u3e by Inducible Expression of the Cdk Inhibitor p21
Mammary carcinomas that develop in C3 (1)/SV40 T- antigen (TAg) transgenic mice have lost the p53-mediated induction of p21, leading to increased cellular proliferation and significant elevations of cyclins and Cdks. To test whether p21 could serve as a target for anticancer therapy for this mammary cancer model, a retroviral delivery system for the inducible expression of p21 was developed. We demonstrate that overexpression of p21 in C3(1)/TAg mammary tumor cells using the retroviral inducible p21 expression system results in increased apoptosis, reduced cell proliferation in vitro and reduced tumor growth in vivo associated with reduced expression of cyclins D1 and E, and Cdks 2, 4, and 6. Reciprocal changes in the expression of p21 and p27(Kip1), another cell-cycle regulator, were also observed. Because reduced p21 expression occurs frequently in human breast cancer, restoration of the Cdk inhibitor p21 by gene therapy approaches may provide a method for inhibiting mammary tumor progression
Haploid loss of bax leads to accelerated mammary tumor development in C3(1)/SV40-TAg transgenic mice: reduction in protective apoptotic response at the preneoplastic stage.
The dramatic increase in apoptosis observed during the development of preneoplastic mammary lesions is associated with a significant elevation in Bax expression in C3(1)/SV40 large T antigen (TAg) transgenic mice. The significance of Bax expression during tumor progression in vivo was studied by generating double-transgenic mice carrying the C3(1)/TAg transgene and mutant alleles for bax. C3(1)/TAg transgenic mice carrying mutant bax alleles exhibited accelerated rates of tumor growth, increased tumor numbers, larger tumor mass and decreased survival rates compared with mice carrying wild-type bax. Accelerated tumorigenesis associated with the bax+/- genotype did not require the loss of function of the second bax allele. Thus, haploid insufficiency of bax is enough to accelerate tumor progression, suggesting that the protective effect of Bax is dose-dependent. While levels of apoptosis in the preneoplastic lesions, but not carcinomas, were reduced in bax+/- or bax-/- mice compared with bax+/+ mice, rates of cellular proliferation in mammary lesions were similar among all bax genotypes. These data demonstrate that bax is a critical suppressor of mammary tumor progression at the stage of preneoplastic mammary lesion development through the upregulation of apoptosis, but that this protective effect is lost during the transition from preneoplasia to invasive carcinoma