711 research outputs found

    Batch fabrication of flowable colorimetric pressure sensing particles via surface micromachining

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    Journal ArticleThe batch fabrication and test of artificial optical resonator slab-type micro particles (14 μm diameter, 0.7 μm gap) is presented as a means to map absolute pressure within microscopic environments. The pressure-sensing particles consist of a semi-transparent elastic polysilicon shell enclosing a reference vacuum cavity. The optical resonance frequency and the corresponding external pressure can hence be interrogated optically via reflectivity measurements. We demonstrate the measurement of internal pressures between 0-20 psi within microfluidic environments

    Alcohol Abstinence Does Not Fully Reverse Abnormalities of Mucosal-Associated Invariant T Cells in the Blood of Patients With Alcoholic Hepatitis

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    OBJECTIVES: Alcoholic hepatitis (AH) develops in approximately 30% of chronic heavy drinkers. The immune system of patients with AH is hyperactivated, yet ineffective against infectious diseases. Mucosal-associated invariant T (MAIT) cells are innate-like lymphocytes that are highly enriched in liver, mucosa, and peripheral blood and contribute to antimicrobial immunity. We aimed to determine whether MAIT cells were dysregulated in heavy drinkers with and without AH and the effects of alcohol abstinence on MAIT cell recovery. METHODS: MR1 tetramers loaded with a potent MAIT cell ligand 5-(2-oxopropylideneamino)-6-d-ribitylaminouracil were used in multiparameter flow cytometry to analyze peripheral blood MAIT cells in 59 healthy controls (HC), 56 patients with AH, and 45 heavy drinkers without overt liver disease (HDC) at baseline and 6- and 12-month follow-ups. Multiplex immunoassays were used to quantify plasma levels of cytokines related to MAIT cell activation. Kinetic Turbidimetric Limulus Amebocyte Lysate Assay and ELISA were performed to measure circulating levels of 2 surrogate markers for bacterial translocation (lipopolysaccharide and CD14), respectively. RESULTS: At baseline, patients with AH had a significantly lower frequency of MAIT cells than HDC and HC. HDC also had less MAIT cells than HC (median 0.16% in AH, 0.56% in HDC, and 1.25% in HC). Further, the residual MAIT cells in patients with AH expressed higher levels of activation markers (CD69, CD38, and human leukocyte antigen [HLA]-DR), the effector molecule granzyme B, and the immune exhaustion molecule PD-1. Plasma levels of lipopolysaccharide and CD14 and several cytokines related to MAIT cell activation were elevated in patients with AH (interferon [IFN]-α, interleukin [IL]-7, IL-15, IL-17, IL-18, IL-23, IFN-γ, and tumor necrosis factor α). Decreased MAIT cell frequency and upregulated CD38, CD69, and HLA-DR correlated negatively and positively, respectively, with aspartate aminotransferase level. MAIT cell frequency negatively correlated with IL-18. HLA-DR and CD38 levels correlated with several cytokines. At follow-ups, abstinent patients with AH had increased MAIT cell frequency and decreased MAIT cell activation. However, MAIT cell frequency was not fully normalized in patients with AH (median 0.31%). DISCUSSION: We showed that HDC had a reduction of blood MAIT cells despite showing little evidence of immune activation, whereas patients with AH had a severe depletion of blood MAIT cells and the residual cells were highly activated. Alcohol abstinence partially reversed those abnormalities

    A DC-DC Step-Up mu-Power Converter for Energy Harvesting Applications, Using Maximum Power PointTracking, Based on Fractional Open Circuit Voltage

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    A DC-DC step-up micro power converter for solar energy harvesting applications is presented. The circuit is based on a switched-capacitorvoltage tripler architecture with MOSFET capacitors, which results in an, area approximately eight times smaller than using MiM capacitors for the 0.131mu m CMOS technology. In order to compensate for the loss of efficiency, due to the larger parasitic capacitances, a charge reutilization scheme is employed. The circuit is self-clocked, using a phase controller designed specifically to work with an amorphous silicon solar cell, in order to obtain themaximum available power from the cell. This will be done by tracking its maximum power point (MPPT) using the fractional open circuit voltage method. Electrical simulations of the circuit, together with an equivalent electrical model of an amorphous silicon solar cell, show that the circuit can deliver apower of 1132 mu W to the load, corresponding to a maximum efficiency of 66.81%

    Post hoc analyses of surrogate markers of non-alcoholic fatty liver disease (NAFLD) and liver fibrosis in patients with type 2 diabetes in a digitally supported continuous care intervention: An open-label, non-randomised controlled study

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    OBJECTIVE: One year of comprehensive continuous care intervention (CCI) through nutritional ketosis improves glycosylated haemoglobin(HbA1c), body weight and liver enzymes among patients with type 2 diabetes (T2D). Here, we report the effect of the CCI on surrogate scores of non-alcoholic fatty liver disease (NAFLD) and liver fibrosis. METHODS: This was a non-randomised longitudinal study, including adults with T2D who were self-enrolled to the CCI (n=262) or to receive usual care (UC, n=87) during 1 year. An NAFLD liver fat score (N-LFS) >-0.640 defined the presence of fatty liver. An NAFLD fibrosis score (NFS) of >0.675 identified subjects with advanced fibrosis. Changes in N-LFS and NFS at 1 year were the main endpoints. RESULTS: At baseline, NAFLD was present in 95% of patients in the CCI and 90% of patients in the UC. At 1 year, weight loss of ≥5% was achieved in 79% of patients in the CCI versus 19% of patients in UC (p<0.001). N-LFS mean score was reduced in the CCI group (-1.95±0.22, p<0.001), whereas it was not changed in the UC (0.47±0.41, p=0.26) (CCI vs UC, p<0.001). NFS was reduced in the CCI group (-0.65±0.06, p<0.001) compared with UC (0.26±0.11, p=0.02) (p<0.001 between two groups). In the CCI group, the percentage of individuals with a low probability of advanced fibrosis increased from 18% at baseline to 33% at 1 year (p<0.001). CONCLUSIONS: One year of a digitally supported CCI significantly improved surrogates of NAFLD and advanced fibrosis in patients with T2D

    Features of Autoimmune Hepatitis in Patients With Drug-induced Liver Injury

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    BACKGROUND & AIMS: Drug-induced liver injury (DILI) has features similar to those of other liver diseases including autoimmune hepatitis (AIH). We aimed to characterize the clinical and autoimmune features of liver injury caused by nitrofurantoin, minocycline, methyldopa, or hydralazine. METHODS: We analyzed data from 88 cases of DILI attributed to nitrofurantoin, minocycline, methyldopa, or hydralazine included in the Drug-Induced Liver Injury Network prospective study from 2004 through 2014. Sera were collected from patients at baseline and follow-up examination and tested for levels of immunoglobulin G (IgG), antibodies to nuclear antigen (ANA), smooth muscle (SMA), and soluble liver antigen (SLA). An autoimmune score was derived on the basis of increases in levels of IgG, ANA, SMA, and SLA (assigned values of 0, 1+, or 2+). AIH-associated HLA-DRB1*03:01 and HLA-DRB1*04:01 allele frequencies were compared with those of the general population (controls). RESULTS: Of the 88 cases, 80 were women (91%), 74% had hepatocellular injury, and 25% had severe injury. At the onset of DILI, 39% of cases had increased levels of IgG, 72% had increased levels of ANA, 60% had increased levels of SMA, and none had increases in SLA. A phenotype of autoimmunity (autoimmune score ≥2) was observed in 82% of cases attributed to nitrofurantoin and 73% of cases attributed to minocycline (73%) but only 55% of cases attributed to methyldopa and 43% of cases attributed to hydralazine (P = .16 for nitrofurantoin and minocycline vs methyldopa and hydralazine). We observed a decrease in numbers of serum samples positive for ANA (P = .01) or SMA (P < .001) and in autoimmune scores (P < .001) between DILI onset and follow-up. Similar percentages of patients with DILI had HLA-DRB1*03:01 (15%) and HLA-DRB1*04:01 (9%) as controls (12% and 9%, respectively). CONCLUSIONS: In analysis of data from the DILIN prospective study, we found that most cases of DILI attributed to nitrofurantoin or minocycline and about half of cases that were due to methyldopa and hydralazine have a phenotype of autoimmunity similar to AIH. These features decrease with recovery of the injury and are not associated with the typical HLA alleles found in patients with idiopathic AIH

    Alcohol Rehabilitation Within 30 Days of Hospital Discharge Is Associated With Reduced Readmission, Relapse, and Death in Patients With Alcoholic Hepatitis

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    Background & Aims Patients admitted to the hospital for alcoholic hepatitis (AH) are at increased risk of readmission and death. We aimed to identify factors associated with readmission, alcohol relapse, and mortality. Methods We performed a retrospective analysis of consecutive patients admitted with AH to a tertiary care hospital from 1999 through 2016 (test cohort, n = 135). We validated our findings in a prospective analysis of patients in a multi-center AH research consortium from 2013 through 2017 (validation cohort, n = 159). Alcohol relapse was defined as any amount of alcohol consumption within 30 days after hospital discharge. Early alcohol rehabilitation was defined as residential or outpatient addiction treatment or mutual support group participation within 30 days after hospital discharge. Results Thirty-day readmission rates were 30% in both cohorts. Alcohol relapse rates were 37% in the test and 34% in the validation cohort. Following hospital discharge, 27 patients (20%) in the test cohort and 19 patients (16%) in the validation cohort attended early alcohol rehabilitation. There were 53 deaths (39%) in a median follow-up time of 2.8 years and 42 deaths (26%) in a median follow-up time of 1.3 years, respectively. In the test cohort, early alcohol rehabilitation reduced odds for 30-day readmission (adjusted odds ratios [AOR] 0.16; 95% CI, 0.04–0.65; P = .01), 30-day alcohol relapse (AOR, 0.11; 95% CI, 0.02–0.53; P < .001), and death (adjusted hazard ratio [AHR], 0.20; 95% CI, 0.05–0.56; P = .001). In the validation cohort early alcohol rehabilitation reduced odds for 30-day readmission (AOR, 0.30; 95% CI, 0.09–0.98; P = .04), 30-day alcohol relapse (AOR 0.09; 95% CI, 0.01–0.73; P = .02), and death (AHR, 0.20; 95% CI, 0.01–0.94; P = .04). A model combining alcohol rehabilitation and bilirubin identified patients with readmission to the hospital within 30 days with an area under the receiver operating characteristic curve of 0.73. Conclusions In an analysis from two cohorts of patients admitted with AH, early alcohol rehabilitation can reduce risk of hospital readmission, alcohol relapse, and death and should be considered as a quality indicator in AH hospitalization treatment

    SDF1-Induced Antagonism of Axonal Repulsion Requires Multiple G-Protein Coupled Signaling Components That Work in Parallel

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    SDF1 reduces the responsiveness of axonal growth cones to repellent guidance cues in a pertussis-toxin-sensitive, cAMP-dependent manner. Here, we show that SDF1's antirepellent effect can be blocked in embryonic chick dorsal root ganglia (DRGs) by expression of peptides or proteins inhibiting either Gαi, Gαq, or Gβγ. SDF1 antirepellent activity is also blocked by pharmacological inhibition of PLC, a common effector protein for Gαq. We also show that SDF1 antirepellent activity can be mimicked by overexpression of constitutively active Gαi, Gαq, or Gαs. These results suggest a model in which multiple G protein components cooperate to produce the cAMP levels required for SDF1 antirepellent activity

    Challenges in Patient Enrollment and Retention in Clinical Studies for Alcoholic Hepatitis: Experience of the TREAT Consortium

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    The TREAT Consortium has carried out clinical studies on alcoholic hepatitis (AH) for over 4 years. We encountered problems with participant recruitment, retention, and eligibility for specific protocols. To improve our ability to carry out such trials, we reviewed recruitment screening logs, end of study logs, and surveyed study coordinators to learn the reasons for missing patients, why patients declined enrollment, and the number of patients eligible for treatment trials. Associations of the recruited subjects’ demographics with their adherence to follow-up appointments were examined. Three hundred eight-seven patients (AH and heavy drinking controls) were enrolled in the observational study, and 55 AH patients were recruited into treatment trials. About half of patients identified with AH could not be recruited; no specific reason could be determined for about two-thirds of these. Among the patients who gave a reason for not participating, the most common reasons were feeling too sick to participate, desire to concentrate on abstinence, and lack of interest in research. Approximately a quarter of the AH patients met eligibility criteria for treatment trials for moderate or severe AH and we were able to recruit half to two-thirds of those eligible. Approximately 35% of participants in the observational study returned for both 6- and 12-month follow-up visits. We did not identify biopsychosocial or demographic correlates of retention in the study. This analysis revealed that attempts at recruitment into trials for AH miss some subjects because of structural issues surrounding their hospital admission, and encounter a high rate of patient refusal to participate. Nonetheless, more than half of the patients who met the eligibility criteria for moderate or severe AH were entered into clinical trials. Retention rates for the observational study are relatively low. These findings need to be accounted for in clinical trial design and power analysis

    Interaction between the patatin-like phospholipase domain-containing protein 3 genotype and coffee drinking and the risk for acute alcoholic hepatitis

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    Only a subset of subjects with excessive alcohol consumption develops alcoholic liver disease (ALD). One of the major risk factors for ALD is the genetic variant of the patatin-like phospholipase domain-containing protein 3 (PNPLA3) gene. Coffee is one of the most commonly consumed beverages, and coffee consumption has been associated with lower levels of serum alanine aminotransferase. The aim of this study was to investigate the role of coffee drinking and PNPLA3 rs738409 and their association with alcoholic hepatitis (AH) in a well-characterized cohort of subjects from the Translational Research and Evolving Alcoholic Hepatitis Treatment consortium. AH subjects and heavy drinking controls without a history of liver disease who were enrolled between May 2013 and May 2016 were included (n = 339), and the details of alcohol and coffee consumption were assessed. The PNPLA3 variant was determined among participants of European ancestry (n = 183). Relationships between baseline data and AH status were determined, and multivariable logistic regression modeling was performed. During the study period, 189 cases with AH and 150 heavy drinking controls were prospectively enrolled. The prevalence of regular coffee consumption was significantly lower in patients with AH compared to controls (20% versus 43%; P < 0.0001). The overall minor allele frequency of the PNPLA3 variant was higher in AH cases. Multivariable logistic regression revealed that coffee consumption and PNPLA3 were significantly associated with AH status at baseline after adjusting for relevant patient characteristics. Conclusion: We found a higher prevalence of AH among heavy drinkers with PNPLA3 G/G and G/C genotypes regardless of coffee consumption status and a higher prevalence of AH among heavy drinkers who were not regular coffee drinkers. These findings remained after considering relevant baseline patient characteristics. Further studies are needed to confirm our observation

    Acute Alcoholic Hepatitis: Natural History and Predictors of Mortality Using a Multicenter Prospective Study

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    Objective: To examine the natural history of acute alcoholic hepatitis (AH) and identify predictors of mortality for AH using data from a prospective multicenter observational study. Participants and Methods: We analyzed data from 164 patients with AH and 131 heavy-drinking controls with no liver disease. Participants underwent clinical/laboratory assessment at baseline and 6 and 12 months after enrollment. Multivariable analyses were conducted to identify variables associated with mortality and examine the association between coffee drinking and risk of AH. Results: Thirty-six patients with AH died during follow-up, with estimated 30-day, 90-day, 180-day, and 1-year survival of 0.91 (95% CI, 0.87-0.96), 0.85 (95% CI, 0.80-0.91), 0.80 (95% CI, 0.74-0.87), and 0.75 (95% CI, 0.68-0.83), respectively. In the multivariable analysis, higher serum bilirubin level (hazard ratio [HR]=1.059; 95% CI, 1.022-1.089), lower hemoglobin level (HR=1.263; 95% CI, 1.012-1.575), and lower platelet count (HR=1.006; 95% CI, 1.001-1.012) were independently associated with mortality in AH. Compared with controls, fewer patients with AH regularly consumed coffee (20% vs 44%; P<.001), and this association between regular coffee drinking and lower risk of AH persisted after controlling for relevant covariates (odds ratio=0.26; 95% CI, 0.15-0.46). Time-dependent receiver operating characteristic curve analysis revealed that Model for End-Stage Liver Disease; Maddrey Discriminant Function; age, serum bilirubin, international normalized ratio, and serum creatinine; and Child-Pugh scores all provided similar discrimination performance at 30 days (area under the curve=0.73-0.77). Conclusion: Alcoholic hepatitis remains highly fatal, with 1-year mortality of 25%. Regular coffee consumption was associated with lower risk of AH in heavy drinkers
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