Explicit MBR All-Symbol Locality Codes

Node failures are inevitable in distributed storage systems (DSS). To enable efficient repair when faced with such failures, two main techniques are known: Regenerating codes, i.e., codes that minimize the total repair bandwidth; and codes with locality, which minimize the number of nodes participating in the repair process. This paper focuses on regenerating codes with locality, using pre-coding based on Gabidulin codes, and presents constructions that utilize minimum bandwidth regenerating (MBR) local codes. The constructions achieve maximum resilience (i.e., optimal minimum distance) and have maximum capacity (i.e., maximum rate). Finally, the same pre-coding mechanism can be combined with a subclass of fractional-repetition codes to enable maximum resilience and repair-by-transfer simultaneously

Alcohol-related liver disease: Areas of consensus, unmet needs and opportunities for further study

A joint meeting of the European Association for the Study of the Liver (EASL) and the American Association for the Study of Liver Diseases (AASLD) was held in London on September 30 and October 1, 2017. The goals of the meeting were to identify areas of broad agreement and disagreement, develop consensus, and determine future directions to ultimately reduce the burden, morbidity, and mortality of alcohol-related liver disease (previously termed alcoholic liver disease). The specific aims of the meeting were to identify unmet needs and areas for future investigation, in order to reduce alcohol consumption, develop markers for diagnosis and prognosis of disease, and create a framework to test novel pharmacological agents with pre-specified treatment endpoints

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

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

Effects of Age, Sex, Body Weight, and Quantity of Alcohol Consumption on Occurrence and Severity of Alcoholic Hepatitis

Background & Aims Only a minority of heavy drinking individuals develop alcoholic hepatitis (AH), for unclear reasons. We analyzed data from the Translational Research and Evolving Alcoholic Hepatitis Treatment cohort: subjects who drink heavily with normal results from liver tests (controls) and patients with AH. We examined risk factors for the development of AH including body mass index (BMI), drinking pattern and quantity, and sex. Methods We compared data from 145 patients with AH cases and 124 controls, based on BMI when they joined the cohort; groups were matched for sex and race. Drinking patterns were assessed using the time line follow back method, the Alcohol Use Disorders Identification Test, and National Institute of Alcohol Abuse and Alcoholism 6-question survey. We performed univariable and multivariable analyses we to assess effects of these factors and their interaction in increasing the risk for AH. We also explored the association between PNPLA3 variants and AH. Results Cases with AH were older (47 vs 44 years; P=.03). For nearly all measures of quantity of alcohol consumed or frequency of binge drinking, controls drank more heavily than cases with AH. We did not find an association between BMI, sex, drinking patterns, and the presence of AH. Age and BMI were independent predictors for severity of AH. When we analyzed cases and controls of European ancestry, the PNPLA3 single nucleotide polymorphism rs738409 was associated with risk for AH (odds ratio, 1.89; P=.007). Conclusion Compared with heavy drinkers without liver disease, subjects with AH consumed lower levels of alcohol and had less binge drinking, suggesting an increased sensitivity to the toxic effects of alcohol. The risk for AH may be associated with the PNPLA3 rs738409 polymorphism

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

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

Alcohol abstinence ameliorates the dysregulated immune profiles in patients with alcoholic hepatitis: A prospective observational study

Alcoholic hepatitis (AH) develops in only a small proportion of heavy drinkers. To better understand the mechanisms underlying this disparity, we conducted a study to define the relationship between AH development and dysregulated immune responses that might be ameliorated by alcohol abstinence. Sixty-eight AH patients, 65 heavy drinking controls without liver disease (HDC), and 20 healthy controls were enrolled and followed up to 12 months. At baseline, HDC and healthy controls had no significant differences in their plasma levels of 38 inflammatory cytokines/chemokines measured using multiplex immunoassays. However, compared to HDC, AH patients had higher baseline levels of 11 cytokines/chemokines (tumor necrosis factor alpha, interleukin 6 [IL-6], IL-8, interferon gamma–induced protein 10, IL-4, IL-9, IL-10, fibroblast growth factor 2, IL-7, IL-15, and transforming growth factor alpha) but lower levels of the anti-inflammatory macrophage-derived chemokine. AH patients also had more activated yet dysfunctional immune cells as monocytes, T cells, and B cells expressed higher levels of cluster of differentiation 38 (CD38) and CD69 but low levels of human leukocyte antigen DR, CD80, and CD86 at baseline. In addition, CD4 T cells produced less interferon-gamma in response to T-cell stimulation. Up-regulated IL-6, IL-8, CD38, and CD69 and down-regulated macrophage-derived chemokine, human leukocyte antigen DR, CD86, and CD80 correlated positively and negatively, respectively, with disease severity. Longitudinal analysis indicated that levels of IL-6, IL-8, CD38, and CD69 were reduced, whereas levels of macrophage-derived chemokine, human leukocyte antigen DR, CD80, and CD86 were increased in abstinent AH patients. All of the cellular immune abnormalities were reversed by day 360 in abstinent AH patients; however, plasma levels of tumor necrosis factor alpha, IL-8, IL-10, fibroblast growth factor 2, and IL-7 remained higher. Conclusion: AH patients were in a highly immune-dysregulated state, whereas HDC showed little evidence of immune activation; alcohol abstinence reversed most, but not all, of the immunological abnormalities

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

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

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