Impact of the COVID-19 Pandemic on Hospitalizations for Alcoholic Hepatitis or Cirrhosis in Alberta, Canada.

BACKGROUND & AIMS: Coronavirus disease 2019 (COVID-19) pandemic lockdown and restrictions had significant disruption to patient care. We aimed to evaluate the impact of COVID-19 restrictions on hospitalizations of patients with alcoholic and nonalcoholic cirrhosis as well as alcoholic hepatitis (AH) in Alberta, Canada. METHODS: We used validated International Classification of Diseases (ICD-9 and ICD-10) coding algorithms to identify liver-related hospitalizations for nonalcoholic cirrhosis, alcoholic cirrhosis, and AH in the province of Alberta between March 2018 and September 2020. We used the provincial inpatient discharge and laboratory databases to identify our cohorts. We used elevated alanine aminotransferase or aspartate aminotransferase, elevated international normalized ratio, or bilirubin to identify AH patients. We compared COVID-19 restrictions (April-September 2020) with prior study periods. Joinpoint regression was used to evaluate the temporal trends among the 3 cohorts. RESULTS: We identified 2916 hospitalizations for nonalcoholic cirrhosis, 2318 hospitalizations for alcoholic cirrhosis, and 1408 AH hospitalizations during our study time. The in-hospital mortality rate was stable in relation to the pandemic for alcoholic cirrhosis and AH. However, nonalcoholic cirrhosis patients had lower in-hospital mortality rate after March 2020 (8.5% vs 11.5%; P = .033). There was a significant increase in average monthly admissions in the AH cohort (22.1/10,000 admissions during the pandemic vs 11.6/10,000 admissions before March 2020; P < .001). CONCLUSIONS: Before and during COVID-19 monthly admission rates were stable for nonalcoholic and alcoholic cirrhosis; however, there was a significant increase in AH admissions. Because alcohol sales surged during the pandemic, future impact on alcoholic liver disease could be detrimental.

Long-Term Follow-up and Quantitative Hepatitis B Surface Antigen Monitoring in North American Chronic HBV Carriers.

INTRODUCTION: Quantitative hepatitis B surface antigen (qHBsAg) combined with HBV DNA may be useful for predicting chronic hepatitis B (CHB) activity and nucleoside analogue (NA) response. MATERIAL AND METHODS: In this retrospective cohort study we evaluated qHBsAg levels according to CHB disease phase and among patients on treatment. Random effect logistic regression analysis was used to analyze qHBsAg change with time in the NA-treated cohort. RESULTS: 545 CHB carriers [56% M, median age 48 y (IQR 38-59), 73% Asian] had qHBsAg testing. In the untreated group (44%), 8% were classified as immune tolerant, 10% immune clearance, 40% inactive, and 43% had HBeAg- CHB and the median HBsAg levels were 4.6 (IQR 3.4-4.9), 4.0 (IQR 3.4-4.5), 2.9 (IQR 1.4-3.8), and 3.2 log IU/mL (IQR 2.6-4.0), respectively; p < 0.001. In the NA-treated group (28% entecavir, 68% tenofovir, 4% lamivudine), no significant change in qHBsAg levels occured with time. However, 19% of patients on long-term NA had sustained qHBsAg < 2 log10 IU/mL. CONCLUSION: qHBsAg titers were associated with CHB phase and remained stable in those on long-term NA. A significant number of treated patients had low-level qHBsAg, of which some may be eligible for treatment discontinuation without risk of flare.

Comparative effectiveness of immunosuppressants and biologics for inducing and maintaining remission in Crohn's disease: a network meta-analysis.

BACKGROUND & AIMS: There is controversy regarding the best treatment for patients with Crohn's disease because of the lack of direct comparative trials. We compared therapies for induction and maintenance of remission in patients with Crohn's disease, based on direct and indirect evidence. METHODS: We performed systematic reviews of MEDLINE, EMBASE, and Cochrane Central databases, through June 2014. We identified randomized controlled trials (N = 39) comparing methotrexate, azathioprine/6-mercaptopurine, infliximab, adalimumab, certolizumab, vedolizumab, or combined therapies with placebo or an active agent for induction and maintenance of remission in adult patients with Crohn's disease. Pairwise treatment effects were estimated through a Bayesian random-effects network meta-analysis and reported as odds ratios (OR) with a 95% credible interval (CrI). RESULTS: Infliximab, the combination of infliximab and azathioprine (infliximab + azathioprine), adalimumab, and vedolizumab were superior to placebo for induction of remission. In pair-wise comparisons of anti-tumor necrosis factor agents, infliximab + azathioprine (OR, 3.1; 95% CrI, 1.4-7.7) and adalimumab (OR, 2.1; 95% CrI, 1.0-4.6) were superior to certolizumab for induction of remission. All treatments were superior to placebo for maintaining remission, except for the combination of infliximab and methotrexate. Adalimumab, infliximab, and infliximab + azathioprine were superior to azathioprine/6-mercaptopurine: adalimumab (OR, 2.9; 95% CrI, 1.6-5.1), infliximab (OR, 1.6; 95% CrI, 1.0-2.5), infliximab + azathioprine (OR, 3.0; 95% CrI, 1.7-5.5) for maintenance of remission. Adalimumab and infliximab + azathioprine were superior to certolizumab: adalimumab (OR, 2.5; 95% CrI, 1.4-4.6) and infliximab + azathioprine (OR, 2.6; 95% CrI, 1.3-6.0). Adalimumab was superior to vedolizumab (OR, 2.4; 95% CrI, 1.2-4.6). CONCLUSIONS: Based on a network meta-analysis, adalimumab and infliximab + azathioprine are the most effective therapies for induction and maintenance of remission of Crohn's disease.

Validation of coding algorithms for the identification of patients hospitalized for alcoholic hepatitis using administrative data.

BACKGROUND: Epidemiologic studies of alcoholic hepatitis (AH) have been hindered by the lack of a validated International Classification of Disease (ICD) coding algorithm for use with administrative data. Our objective was to validate coding algorithms for AH using a hospitalization database. METHODS: The Hospital Discharge Abstract Database (DAD) was used to identify consecutive adults (≥18 years) hospitalized in the Calgary region with a diagnosis code for AH (ICD-10, K70.1) between 01/2008 and 08/2012. Medical records were reviewed to confirm the diagnosis of AH, defined as a history of heavy alcohol consumption, elevated AST and/or ALT (<300 U/L), serum bilirubin >34 µmol/L, and elevated INR. Subgroup analyses were performed according to the diagnosis field in which the code was recorded (primary vs. secondary) and AH severity. Algorithms that incorporated ICD-10 codes for cirrhosis and its complications were also examined. RESULTS: Of 228 potential AH cases, 122 patients had confirmed AH, corresponding to a positive predictive value (PPV) of 54% (95% CI 47-60%). PPV improved when AH was the primary versus a secondary diagnosis (67% vs. 21%; P < 0.001). Algorithms that included diagnosis codes for ascites (PPV 75%; 95% CI 63-86%), cirrhosis (PPV 60%; 47-73%), and gastrointestinal hemorrhage (PPV 62%; 51-73%) had improved performance, however, the prevalence of these diagnoses in confirmed AH cases was low (29-39%). CONCLUSIONS: In conclusion the low PPV of the diagnosis code for AH suggests that caution is necessary if this hospitalization database is used in large-scale epidemiologic studies of this condition.

Caring for the Aging Patient With Adult Congenital Heart Disease: A Review of Cardiac and Noncardiac Comorbidities.

As the demographics of congenital heart disease (CHD) have shifted, there are now more adults living with CHD than children in North America. This presents unprecedented challenges as patients with CHD acquire noncardiac comorbidities and seek care for a variety of reasons, including noncardiac surgery and emergency department (ED) visits. CHD shifts from a one organ problem to a multisystem disease and requires a team of specialists to maintain high-quality longitudinal care. In this review, we summarize the challenges patients with CHD and their providers face as they age. We review the demographics of CHD and health care utilization. We examine the rates of noncardiac comorbidities and the current quality of care received by adult patients with CHD.

Les caractéristiques démographiques des patients atteints d'une cardiopathie congénitale ont changé : à l'heure actuelle, en Amérique du Nord, il y a plus d'adultes qui présentent une cardiopathie congénitale que d'enfants. Cela représente un défi sans précédent lorsque ces patients ont des troubles concomitants non cardiaques et doivent subir une chirurgie non cardiaque, par exemple, ou se rendre aux urgences pour toutes sortes de raisons. On ne parle alors plus de l'atteinte d'un seul organe, mais bien d'une maladie multisystémique. Une équipe pluridisciplinaire sera nécessaire pour maintenir des soins longitudinaux de haute qualité.Dans notre article, nous faisons le point sur les défis que les personnes atteintes d'une cardiopathie congénitale et les dispensateurs de soins doivent affronter à mesure que le patient avance en âge. Nous passons en revue les données démographiques sur les cardiopathies congénitales ainsi que celles sur l'utilisation des services de santé. Nous examinons la fréquence des comorbidités non cardiaques, tout comme la qualité des soins que reçoivent actuellement les patients atteints d'une cardiopathie congénitale.

Real-world tertiary referral centre experience stopping nucleos(t)ide analogue therapy in patients with chronic hepatitis B.

BACKGROUND: Identifying strategies for stopping nucleos(t)ide analogues (NUC) in patients with chronic hepatitis B (CHB) is a major goal in CHB management. Our study describes our tertiary-centre experience stopping nucleos(t)ide analogues (NUC) in CHB. METHODS: We conducted a retrospective cohort study of all individuals with CHB seen at the Calgary Liver Unit between January 2009 and May 2020 who stopped NUC. We collected baseline demographics and HBV lab parameters before and after stopping NUC with results stratified by off-treatment durability. Clinical flare was defined as alanine aminotransferase (ALT) over twice the upper limit of normal and virological flare as HBV DNA >2000 IU/mL. RESULTS: Forty-seven (3.5%) of the 1337 individuals with CHB stopped NUC therapy. During follow-up, six patients (12.8%) restarted NUCs because of a flare. All flares occurred within six months of discontinuation. Median time to restart treatment was 90 days (Q1 65, Q3 133). Upon restarting, all showed suppression of HBV DNA and ALT normalization. Factors associated with restarting NUC therapy included hepatitis B e antigen (HBeAg) positive status at first appointment and longer NUC consolidation therapy. Age, sex, ethnicity, liver stiffness measurement, choice of NUC, and quantitative hepatitis B surface antigen (qHBsAg) level at stopping were not associated with sustained response off-treatment. Six patients had functional cure with HBsAg loss. CONCLUSIONS: Stopping long-term NUC is feasible in HBeAg negative CHB. Hepatic flares can occur despite low levels of qHBsAg. Finite NUC therapy can be considered in eligible patients who are adherent to close monitoring and follow-up, particularly in the first six months after stopping NUC therapy.

Mapping and functional characterization of the murine smoothelin-like 1 promoter.

BACKGROUND: Smoothelin-like 1 (SMTNL1, also known as CHASM) plays a role in promoting relaxation as well as adaptive responses to exercise, pregnancy and sexual development in smooth and skeletal muscle. Investigations of Smtnl1 transcriptional regulation are still lacking. Thus, in this study, we identify and characterize key regulatory elements of the mouse Smtnl1 gene. RESULTS: We mapped the key regulatory elements of the Smtnl1 promoter region: the transcriptional start site (TSS) lays -44 bp from the translational start codon and a TATA-box motif at -75 bp was conserved amongst all mammalian Smtnl1 promoters investigated. The Smtnl1 proximal promoter enhances expression up to 8-fold in smooth muscle cells and a second activating region lays 500 bp further upstream. Two repressing motifs were present (-118 to -218 bp and -1637 to -1869 bp). The proximal promoter is highly conserved in mammals and contains a mirror repeat sequence. In silico analysis suggests many transcription factors (notably MyoD) could potentially bind within the Smtnl1 proximal promoter sequence. CONCLUSION: Smtnl1 transcript was identified in all smooth muscle tissues examined to date, albeit at much lower levels than found in skeletal muscle. It is unlikely that multiple SMTNL1 isoforms exist since a single Smtnl1 transcription start site was identified in both skeletal and intestinal smooth muscle. Promoter studies suggest restrictive control of Smtnl1 expression in non-muscle cells.

Assessment of Canadian policies regarding liver transplant candidacy of people who use alcohol, tobacco, cannabis, and opiates.

Background: When last assessed in 2013, all Canadian liver transplant programs required 6 months of abstinence from alcohol. New studies have questioned the validity of this policy. Moreover, with recreational cannabis now legal in Canada, more transplant candidates may use cannabis. Given these changes, our objective was to obtain an understanding of current Canadian practices regarding liver transplantation and candidates with addiction or alcohol, tobacco, cannabis, or opiate use. Methods: Electronic surveys were distributed to the medical directors of all seven adult liver transplant programs in Canada. Questions were based on either a Likert-scale ranking or free response. The complete data set was aggregated to provide a national perspective on this topic and ensure each individual program remained anonymous. Results: All seven programs responded to the survey. Of these programs, 43% always require 6-month abstinence from alcohol, 29% usually require it, and 14% sometimes require it. Formal alcohol rehabilitation is mandatory in two programs. The majority (57%) of programs never or rarely consider transplant for patients with acute alcoholic hepatitis; 29% require smoking cessation before consideration for transplant; and 71% felt that cannabis use is rarely or never a contraindication to liver transplantation. Conclusions: Significantly more Canadian programs now perform liver transplant for patients who have less than 6 months abstinence from alcohol, and alcoholic hepatitis is no longer an absolute contraindication in Canada. Policies on smoking and opiates are quite variable. Further study and discussion are critical for development of national policies to obtain equitable access to liver transplant for all.

Real-world clinical and virological outcomes in a retrospective multiethnic cohort study of 341 untreated and tenofovir disoproxil fumarate-treated chronic hepatitis B pregnant patients in North America.

BACKGROUND: There are limited long-term data on outcomes of chronic hepatitis B (CHB) in untreated and tenofovir disoproxil fumarate (TDF)-treated women during pregnancy. AIMS: To assess clinical outcomes in a multiethnic cohort of patients during pregnancy and post-partum in a low HBV endemic region. METHODS: Retrospective real-world study of women with CHB (treated or untreated with TDF) from 2011 to 2019; data including ALT, HBV DNA, HBeAg and liver stiffness measurement were collected during pregnancy and post-partum. RESULTS: In 341 women (446 pregnancies) followed for a median of 33 months (IQR: 26.7-39.5) post-partum, 19% (65/341) received TDF (11 initiated pre-pregnancy, 53 for mother-to-child transmission (MTCT) prevention). During follow-up, 72/341 had subsequent pregnancy, including 18/53 on TDF for MTCT risk, of whom 7/18 were re-treated. In all TDF-treated women, HBV DNA declined but rebounded after TDF withdrawal (median baseline, near birth and early follow-up levels were 7.2, 3.0 and 5.5 log IU/mL respectively [P < 0.01]). In HBeAg+ patients (65/341) ALT flares were more common (P = 0.03), especially for those who stopped TDF post-partum, requiring re-treatment in 21% (11/53). In comparison, 54% (116/215) of untreated women had a post-partum ALT flare; one with fulminant hepatitis underwent transplant 13 months post-partum. HBsAg clearance occurred in 2.6% (9/341, 3/9 HBeAg+, 2/9 TDF treated) at median 30 months (IQR: 23-40) and 37% (24/65) of HBeAg+ patients had HBeAg loss at median 17 months (IQR: 12-26) post-partum. CONCLUSIONS: Post-partum ALT flares were common, especially after TDF withdrawal. Overall, 37% achieved HBeAg clearance and 2.9% had HBsAg loss during long-term follow-up.

Ca2+-independent contraction of longitudinal ileal smooth muscle is potentiated by a zipper-interacting protein kinase pseudosubstrate peptide.

As a regulator of smooth muscle contraction, zipper-interacting protein kinase (ZIPK) can directly phosphorylate the myosin regulatory light chains (LC20) and produce contractile force. Synthetic peptides (SM-1 and AV25) derived from the autoinhibitory region of smooth muscle myosin light chain kinase can inhibit ZIPK activity in vitro. Paradoxically, treatment of Triton-skinned ileal smooth muscle strips with AV25, but not SM-1, potentiated Ca2+-independent, microcystin- and ZIPK-induced contractions. The AV25-induced potentiation was limited to ileal and colonic smooth muscles and was not observed in rat caudal artery. Thus the potentiation of Ca2+-independent contractions by AV25 appeared to be mediated by a mechanism unique to intestinal smooth muscle. AV25 treatment elicited increased phosphorylation of LC20 (both Ser-19 and Thr-18) and myosin phosphatase-targeting subunit (MYPT1, inhibitory Thr-697 site), suggesting involvement of a Ca2+-independent LC20 kinase with coincident inhibition of myosin phosphatase. The phosphorylation of the inhibitor of myosin phosphatase, CPI-17, was not affected. The AV25-induced potentiation was abolished by pretreatment with staurosporine, a broad-specificity kinase inhibitor, but specific inhibitors of Rho-associated kinase, PKC, and MAPK pathways had no effect. When a dominant-negative ZIPK [kinase-dead ZIPK((1-320))-D161A] was added to skinned ileal smooth muscle, the potentiation of microcystin-induced contraction by AV25 was blocked. Furthermore, pretreatment of skinned ileal muscle with SM-1 abolished AV25-induced potentiation. We conclude, therefore, that, even though AV25 is an in vitro inhibitor of ZIPK, activation of the ZIPK pathway occurs following application of AV25 to permeabilized ileal smooth muscle. Finally, we propose a mechanism whereby conformational changes in the pseudosubstrate region of ZIPK permit augmentation of ZIPK activity toward LC(20) and MYPT1 in situ. AV25 or molecules based on its structure could be used in therapeutic situations to induce contractility in diseases of the gastrointestinal tract associated with hypomotility.

The role of the calponin homology domain of smoothelin-like 1 (SMTNL1) in myosin phosphatase inhibition and smooth muscle contraction.

In this study, we provide further insight into the contribution of the smoothelin-like 1 (SMTNL1) calponin homology (CH)-domain on myosin light chain phosphatase (SMPP-1M) activity and smooth muscle contraction. SMTNL1 protein was shown to have inhibitory effects on SMPP-1M activity but not on myosin light chain kinase (MLCK) activity. Treatment of beta-escin permeabilized rabbit, ileal smooth muscle with SMTNL1 had no effect on the time required to reach half-maximal force (t(1/2)) during stimulation with pCa6.3 solution. The addition of recombinant SMTNL1 protein to permeabilized, smooth muscle strips caused a significant decrease in contractile force. While the calponin homology (CH)-domain was essential for maximal SMTNL1-associated relaxation, it alone did not cause significant changes in force. SMTNL1 was poorly dephosphorylated by PP-1C in the presence of the myosin targeting subunit (MYPT1), suggesting that phosphorylated SMTNL1 does not possess "substrate trapping" properties. Moreover, while full-length SMTNL1 could suppress SMPP-1M activity toward LC(20) in vitro, truncated SMTNL1 lacking the CH-domain was ineffective. In summary, our findings suggest an important role for the CH-domain in mediating the effects of SMTNL1 on smooth muscle contraction.

Real-world treatment of hepatitis C with second-generation direct-acting antivirals: initial results from a multicentre Canadian retrospective cohort of diverse patients.

BACKGROUND: High hepatitis C cure rates have been observed in registration trials with second-generation direct-acting antivirals. Real-world data also indicate high sustained viral response (SVR) rates. Our objective was to determine real-world SVR rates for patients infected with hepatitis C virus (HCV) who were treated with second-generation direct-acting antivirals in the first 18 months of their availability in Canada. METHODS: Four centres in Calgary contributed their treatment data for a diverse patient population including those who had or had not undergone liver transplantation, those coinfected with HIV and vulnerable populations. We included all patients documented to have started hepatitis C treatment with direct-acting antivirals between October 2014 and April 2016, with follow-up through October 2016. We used multivariate analysis to determine independent predictors of treatment failure. RESULTS: Outcome data were available for 351 patients, of whom 326 (92.9%) achieved an SVR (193/206 [93.7%], 57/59 [96.6%] and 44/51 [86.3%] for genotypes 1a, 1b and 3, respectively, p = 0.2). Independent predictors of not achieving SVR were older age (adjusted odds ratio [OR] 0.95 [95% confidence interval (CI) 0.90-1.00]), male sex (adjusted OR 0.30 [95% CI 0.10-0.89]) and, in patients with genotype 1a infection, history of hepatocellular carcinoma (adjusted OR 0.13 [95% CI 0.03-0.53]). In the entire cohort, the presence of cirrhosis, genotype and hepatocellular carcinoma were not associated with a lower SVR rate. There were no differences in SVR rate according to treatment centre, HIV coinfection or liver transplantation. Among patients with genotype 3 infection, a significantly lower SVR rate was observed for those treated outside of standard of care than for those treated within standard of care (33.3% v. 89.6%, p = 0.04). De novo hepatocellular carcinoma developed in 12 patients (3.4%) despite successful direct-acting antiviral therapy. INTERPRETATION: We report high SVR rates in a real-world diverse cohort of HCV-infected patients treated with second-generation direct-acting antivirals. The results highlight the importance of conducting real-world analyses to elucidate clinical factors associated with poorer outcomes that may not be identified in registration trials.

Purification of smooth muscle myosin phosphatase using a thiophosphorylated myosin light-chain-affinity resin.

Many protein kinases are able to catalyze the thiophosphorylation of protein substrates via a phospho-transfer reaction using adenosine-5'-o(3-thiotriphosphate) (ATPgammaS) (1), but, in general, thiophosphorylated proteins are very poor substrates for protein phosphatases (2,3). As a result, the protein substrate is essentially trapped in the phosphorylated state. This thiophosphorylation can be exploited in order to generate a strategy for the selective purification of protein phosphatases. Indeed, a number of thiophosphorylated protein substrates have been successfully used for the affinity purification of protein phosphatases (4-7). Here we describe the use of thiophosphorylated smooth muscle myosin regulatory light chains for the selective purification of the smooth muscle myosin phosphatase holoenzyme.

Hepatitis B virus testing and linkage to care in a Canadian urban tertiary referral centre: a retrospective cohort study.

BACKGROUND: Despite universal vaccination, chronic hepatitis B virus (HBV) infection remains a public health concern in North America owing to immigration. We aimed to characterize the number of people with a positive result of testing for HBV surface antigen (HBsAg) in Calgary, a large urban Canadian health care region, and to assess whether recommended laboratory tests and specialist consultation were done for those identified as HBsAg-positive. METHODS: Based on laboratory and Alberta Health Services administrative data, we identified all adults (age > 18 yr) with a positive HBsAg test result from Jan. 1 to Dec. 31, 2014 within the Calgary Zone. Demographic and relevant laboratory data were extracted within 6 months of a positive HBsAg test result, and referral to hepatology (2011-2014) was identified from data on referral to a centralized clinic. Parametric and nonparametric statistical methods were used for analyses. RESULTS: We identified 1214 HBsAg-positive people (584 women [48.1%]; median age 44 [interquartile range (IQR) 36-55] yr). A total of 1192 people (98.2%) had alanine aminotransferase testing (median level 23 [IQR 16-34] U/L; 117 [9.8%] with elevated levels), 682 (56.2%) had testing for HBV DNA (median level 2.8 [IQR 2.1-3.8] logIU/mL), 630 (51.9%) had HBV e antigen testing (negative result in 548 [87.0%]), and 145 (11.9%) had HBV e antibody testing (positive result in 111 [76.6%]). Overall, 144 people (11.9%) received anti-HBV treatment, and 390 (32.1%) were referred to a hepatologist. INTERPRETATION: Many HBsAg-positive people in Calgary did not receive the recommended laboratory assessments. The results highlight the necessity of continual public health efforts to screen for chronic HBV infection in Canada and to ensure adequate follow-up in order to reach the World Health Organization's goal of viral hepatitis elimination by 2030.

Integrin-linked kinase is responsible for Ca2+-independent myosin diphosphorylation and contraction of vascular smooth muscle.

Smooth muscle contraction is activated by phosphorylation at Ser-19 of LC20 (the 20 kDa light chains of myosin II) by Ca2+/calmodulin-dependent MLCK (myosin light-chain kinase). Diphosphorylation of LC20 at Ser-19 and Thr-18 is observed in smooth muscle tissues and cultured cells in response to various contractile stimuli, and in pathological circumstances associated with hypercontractility. MLCP (myosin light-chain phosphatase) inhibition can lead to LC20 diphosphorylation and Ca2+-independent contraction, which is not attributable to MLCK. Two kinases have emerged as candidates for Ca2+-independent LC20 diphosphorylation: ILK (integrin-linked kinase) and ZIPK (zipper-interacting protein kinase). Triton X-100-skinned rat caudal arterial smooth muscle was used to investigate the relative importance of ILK and ZIPK in Ca2+-independent, microcystin (phosphatase inhibitor)-induced LC20 diphosphorylation and contraction. Western blotting and in-gel kinase assays revealed that both kinases were retained in this preparation. Ca2+-independent contraction of calmodulin-depleted tissue in response to microcystin was resistant to MLCK inhibitors [AV25 (a 25-amino-acid peptide derived from the autoinhibitory domain of MLCK), ML-7, ML-9 and wortmannin], protein kinase C inhibitor (GF109203X) and Rho-associated kinase inhibitors (Y-27632 and H-1152), but blocked by the non-selective kinase inhibitor staurosporine. ZIPK was inhibited by AV25 (IC50 0.63+/-0.05 microM), whereas ILK was insensitive to AV25 (at concentrations as high as 100 microM). AV25 had no effect on Ca2+-independent, microcystin-induced LC20 mono- or di-phosphorylation, with a modest effect on force. We conclude that direct inhibition of MLCP in the absence of Ca2+ unmasks ILK activity, which phosphorylates LC20 at Ser-19 and Thr-18 to induce contraction. ILK is probably the kinase responsible for myosin diphosphorylation in vascular smooth muscle cells and tissues.

Risk factors for mortality in patients with alcoholic hepatitis and assessment of prognostic models: A population-based study.

BACKGROUND: Severe alcoholic hepatitis (AH) is associated with a substantial risk for short-term mortality. OBJECTIVES: To identify prognostic factors and validate well-known prognostic models in a Canadian population of patients hospitalized for AH. METHODS: In the present retrospective study, patients hospitalized for AH in Calgary, Alberta, between January 2008 and August 2012 were included. Stepwise logistic regression models identified independent risk factors for 90-day mortality, and the discrimination of prognostic models (Model for End-stage Liver Disease [MELD] and Maddrey discriminant function [DF]) were examined using areas under the ROC curves. RESULTS: A total of 122 patients with AH were hospitalized during the study period; the median age was 49 years (interquartile range [IQR] 42 to 55 years) and 60% were men. Median MELD score and Maddrey DF on admission were 21 (IQR 18 to 24) and 45 (IQR 26 to 62), respectively. Seventy-three percent of patients received corticosteroids and/or pentoxifylline, and the 90-day mortality was 17%. Independent predictors of mortality included older age, female sex, international normalized ratio, MELD score and Maddrey DF (all P<0.05). For discrimination of 90-day mortality, the areas under the ROC curves of the prognostic models (MELD 0.64; Maddrey DF 0.68) were similar (P>0.05). At optimal cut-offs of ≥22 for MELD score and ≥37 for Maddrey DF, both models excluded death with high certainty (negative predictive values 90% and 96%, respectively). CONCLUSIONS: In patients hospitalized for AH, well-known prognostic models can be used to predict 90-day mortality, particularly to identify patients with a low risk for death.

Modulation of smooth muscle contractility by CHASM, a novel member of the smoothelin family of proteins.

Cyclic nucleotides acting through their associated protein kinases, the cGMP- and cAMP-dependent protein kinases, can relax smooth muscles without a change in free intracellular calcium concentration ([Ca2+]i), a phenomenon referred to as Ca2+ desensitization. The molecular mechanisms by which these kinases bring about Ca2+ desensitization are unknown and an understanding of this phenomenon may lead to better therapies for treating diseases involving defects in the contractile response of smooth muscles such as hypertension, bronchospasm, sexual dysfunction, gastrointestinal disorders and glaucoma. Utilizing a combination of real-time proteomics and smooth muscle physiology, we characterized a distinct subset of protein targets for cGMP-dependent protein kinase in smooth muscle. Among those phosphoproteins identified was calponin homology-associated smooth muscle (CHASM), a novel protein that contains a calponin homology domain and shares sequence similarity with the smoothelin family of smooth muscle specific proteins. Recombinant CHASM was found to evoke relaxation in a concentration dependent manner when added to permeabilized smooth muscle. A co-sedimentation assay with actin demonstrated that CHASM does not possess actin binding activity. Our findings indicate that CHASM is a novel member of the smoothelin protein family that elicits Ca2+ desensitization in smooth muscle.