43 research outputs found

    The Protective Effects of Trypsin Inhibitor on Hepatic Ischemia-Reperfusion Injury and Liver Graft Survival

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    The aim of this study was to explore the protective effects of ulinastatin (urinary trypsin inhibitor, UTI) on liver ischemia-reperfusion injury (IRI) and graft survival. We employed mouse liver cold IRI and orthotopic liver transplantation (OLTx) models. UTI was added to lactated Ringer’s (LR) solution for liver perfusion and preservation in vitro or combined with UTI injection intraperitoneally to the liver graft recipient. Our results indicated that UTI supplementation protected the liver from cold IRI in a dose-dependent manner and prolonged liver graft survival from extended cold preserved liver donors significantly. The underlying mechanism of UTI on liver IRI may be mediated by inhibition of proinflammatory cytokine release, increasing the expression of the antiapoptotic gene Bcl-2 and decreasing the expression of the proapoptosis genes of Caspase-3 and Bax, and further protects hepatocytes from apoptotic death and improves liver function

    Mutant Kras- and p16-regulated NOX4 activation overcomes metabolic checkpoints in development of pancreatic ductal adenocarcinoma

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    Kras activation and p16 inactivation are required to develop pancreatic ductal adenocarcinoma (PDAC). However, the biochemical mechanisms underlying these double alterations remain unclear. Here we discover that NAD(P)H oxidase 4 (NOX4), an enzyme known to catalyse the oxidation of NAD(P)H, is upregulated when p16 is inactivated by looking at gene expression profiling studies. Activation of NOX4 requires catalytic subunit p22phox, which is upregulated following Kras activation. Both alterations are also detectable in PDAC cell lines and patient specimens. Furthermore, we show that elevated NOX4 activity accelerates oxidation of NADH and supports increased glycolysis by generating NAD+, a substrate for GAPDH-mediated glycolytic reaction, promoting PDAC cell growth. Mechanistically, NOX4 was induced through p16-Rb-regulated E2F and p22phox was induced by KrasG12V-activated NF-ÎșB. In conclusion, we provide a biochemical explanation for the cooperation between p16 inactivation and Kras activation in PDAC development and suggest that NOX4 is a potential therapeutic target for PDAC

    Sex Differences in Abnormal Intrinsic Functional Connectivity After Acute Mild Traumatic Brain Injury

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    Mild traumatic brain injury (TBI) is considered to induce abnormal intrinsic functional connectivity within resting-state networks (RSNs). The objective of this study was to estimate the role of sex in intrinsic functional connectivity after acute mild TBI. We recruited a cohort of 54 patients (27 males and 27 females with mild TBI within 7 days post-injury) from the emergency department (ED) and 34 age-, education-matched healthy controls (HCs; 17 males and 17 females). On the clinical scales, there were no statistically significant differences between males and females in either control group or mild TBI group. To detect whether there was abnormal sex difference on functional connectivity in RSNs, we performed independent component analysis (ICA) and a dual regression approach to investigate the between-subject voxel-wise comparisons of functional connectivity within seven selected RSNs. Compared to female patients, male patients showed increased intrinsic functional connectivity in motor network, ventral stream network, executive function network, cerebellum network and decreased connectivity in visual network. Further analysis demonstrated a positive correlation between the functional connectivity in executive function network and insomnia severity index (ISI) scores in male patients (r = 0.515, P = 0.006). The abnormality of the functional connectivity of RSNs in acute mild TBI showed the possibility of brain recombination after trauma, mainly concerning male-specific

    Oxidative Stress and Liver Cancer: Etiology and Therapeutic Targets

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    Accumulating evidence has indicated that oxidative stress (OS) is associated with the development of hepatocellular carcinoma (HCC). However, the mechanisms remain largely unknown. Normally, OS occurs when the body receives any danger signal—from either an internal or external source—and further induces DNA oxidative damage and abnormal protein expression, placing the body into a state of vulnerability to the development of various diseases such as cancer. There are many factors involved in liver carcinogenesis, including hepatitis B virus (HBV) and hepatitis C virus (HCV) infection, alcohol abuse, and nonalcoholic fatty liver disease (NAFLD). The relationship between OS and HCC has recently been attracting increasing attention. Therefore, elucidation of the impact of OS on the development of liver carcinogenesis is very important for the prevention and treatment of liver cancer. This review focuses mainly on the relationship between OS and the development of HCC from the perspective of cellular and molecular mechanisms and the etiology and therapeutic targets of HCC

    Evaluating the value of 18F-PSMA-1007 PET/CT in the detection and identification of prostate cancer using histopathology as the standard

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    Abstract Background Prostate-specific membrane antigen (PSMA) PET/CT is a highly regarded radionuclide imaging modality for prostate cancer (PCa). This study aimed to evaluate the diagnostic performance of 18F-PSMA-1007 PET/CT in detecting intraprostatic lesions of PCa using radical prostatectomy (RP) specimens as a reference standard and to establish an optimal maximum standardized uptake value (SUVmax) cutoff for distinguishing between PCa and non-PCa lesions. Methods We retrospectively collected 117 patients who underwent 18F-PSMA-1007 PET/CT before RP. The uptake of the index tumor and contralateral non-PCa lesion was assessed. Histopathology of RP specimens was used as the gold standard. Kappa test was used to evaluate the consistency of preoperative PSMA PET/CT staging and postoperative pathological staging. Finally, an SUVmax cutoff value was identified by receiver operating characteristic (ROC) curve analysis to distinguish PCa lesions from non-PCa lesions. A prospective cohort including 76 patients was used to validate the results. Results The detection rate of 18F-PSMA-1007 PET/CT for prostate cancer was 96.6% (113/117). 18F-PSMA-1007 had a sensitivity of 91.2% and a positive predictive value (PPV) of 89.8% for the identification of intraprostatic lesions. The consistency test (Kappa = 0.305) indicated poor agreement between the pathologic T-stage and PSMA PET/CT T-stage. Based on ROC curve analysis, the appropriate SUVmax to diagnose PCa lesions was 8.3 (sensitivity of 71.3% and specificity 96.8%) with an area under the curve (AUC) of 0.93 (P < 0.001). This SUVmax cutoff discriminated PCa lesions from non-PCa lesions with a sensitivity of 74.4%, a specificity of 95.8% in the prospective validation group. Conclusions 18F-PSMA-1007 PET/CT demonstrated excellent performance in detecting PCa. An optimal SUVmax threshold (8.3) could be utilized to identify lesions of PCa by 18F-PSMA-1007 PET/CT. Trial registration ClinicalTrials.gov Identifier: NCT04521894, Registered: August 17, 2020

    Folate in the United States Population and its Association with Congestive Heart Failure

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    Background: To investigate the relationship between red blood cell (RBC) folate and congestive heart failure (CHF). Methods: We extracted the concentrations of RBC folate and collated CHF information from the National Health and Nutrition Examination Survey (NHANES) survey (12820 individuals). Weighted univariate logistic regression, weighted multivariate logistic regression, and restrictive cubic spline (RCS) were used to assess the relationship between RBC folate concentrations and CHF. Results: The unadjusted model showed that the highest tertile group of RBC folate concentration was significantly associated with a higher risk of CHF compared to the lowest tertile group of RBC folate levels (odds ratio [OR] = 3.09; 95% confidence interval [CI], 2.14–4.46). Similar trends were seen in the multivariate-adjusted analysis (OR = 1.98; 95% CI: 1.27–3.09). The OR was >1.0 when the predicted RBC folate exceeded 2757 nmol/L in the RCS model, indicating that the risk of CHF was low and relatively stable up to a predicted RBC folate level of 2757 nmol/L, but began to increase rapidly thereafter (p = 0.001). Conclusions: The risk of CHF may be increased either by high RBC folate concentrations (highest tertile of RBC folate or >2637 nmol/L) or by folate deficiency. Considering the two sides of the association between RBC folate and CHF, there is a need for large-scale clinical research to better investigate if the association between RBC folate and CHF is a cause-effect relationship, what are the underlying pathophysiological basis, as well as to identify optimal dietary folate equivalent (DFE) and RBC folate concentration intervals

    Standardized Data to Improve Understanding and Modeling of Soil Nitrogen at Continental Scale

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    Nitrogen (N) is a key limiting nutrient in terrestrial ecosystems, but there remain critical gaps in our ability to predict and model controls on soil N cycling. This may be in part due to lack of standardized sampling across broad spatial–temporal scales. Here, we introduce a continentally distributed, publicly available data set collected by the National Ecological Observatory Network (NEON) that can help fill these gaps. First, we detail the sampling design and methods used to collect and analyze soil inorganic N pool and net flux rate data from 47 terrestrial sites. We address methodological challenges in generating a standardized data set, even for a network using uniform protocols. Then, we evaluate sources of variation within the sampling design and compare measured net N mineralization to simulated fluxes from the Community Earth System Model 2 (CESM2). We observed wide spatiotemporal variation in inorganic N pool sizes and net transformation rates. Site explained the most variation in NEON’s stratified sampling design, followed by plots within sites. Organic horizons had larger pools and net N transformation rates than mineral horizons on a sample weight basis. The majority of sites showed some degree of seasonality in N dynamics, but overall these temporal patterns were not matched by CESM2, leading to poor correspondence between observed and modeled data. Looking forward, these data can reveal new insights into controls on soil N cycling, especially in the context of other environmental data sets provided by NEON, and should be leveraged to improve predictive modeling of the soil N cycle.This article is published as Weintraub-Leff, S. R., Hall, S. J., Craig, M. E., Sihi, D., Wang, Z., & Hart, S. C. (2023). Standardized data to improve understanding and modeling of soil nitrogen at continental scale. Earth's Future, 11, e2022EF003224. https://doi.org/10.1029/2022EF003224. Posted with permission.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited

    Coupling of Phosphorus Processes With Carbon and Nitrogen Cycles in the Dynamic Land Ecosystem Model: Model Structure, Parameterization, and Evaluation in Tropical Forests

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    Abstract The biogeochemical processes of carbon (C), nitrogen (N), and phosphorous (P) are fully coupled in the Earth system, which shape the structure, functioning, and dynamics of terrestrial ecosystems. However, the representation of P cycle in terrestrial biosphere models (TBMs) is still in an early stage. Here we incorporated P processes and C‐N‐P interactions into the C‐N coupled Dynamic Land Ecosystem Model (DLEM‐CNP), which had a major feature of the ability in simulating the N and P colimitation on vegetation C assimilation. DLEM‐CNP was intensively calibrated and validated against daily or annual observations from four eddy covariance flux sites, two Hawaiian sites along a chronosequence of soils, and other 13 tropical forest sites. The results indicate that DLEM‐CNP significantly improved simulations of forest gross and net primary production (R2: 0.36–0.97, RMSE:1.1–1.49 g C m−2 year−1 for daily GPP at eddy covariance flux sites; R2 = 0.92, RMSE = 176.7 g C m−2 year−1 for annual NPP across 13 tropical forest sites). The simulations were also consistent with field observations in terms of biomass, leaf N:P ratio and plant response to fertilizer addition. A sensitivity analysis suggests that simulated results are reasonably robust against uncertainties in model parameter estimates and the model was very sensitive to parameters of P uptake. These results suggest that incorporating P processes and N‐P interaction into terrestrial biosphere models is of critical importance for accurately estimating C dynamics in tropical forests, particularly those P‐limited ones
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