Neurally adjusted ventilatory assist decreases ventilator-induced lung injury and non-pulmonary organ dysfunction in rabbits with acute lung injury

OBJECTIVE: To determine if neurally adjusted ventilatory assist (NAVA) that delivers pressure in proportion to diaphragm electrical activity is as protective to acutely injured lungs (ALI) and non-pulmonary organs as volume controlled (VC), low tidal volume (Vt), high positive end-expiratory pressure (PEEP) ventilation. DESIGN: Prospective, randomized, laboratory animal study. SUBJECTS: Twenty-seven male New Zealand white rabbits. INTERVENTIONS: Anesthetized rabbits with hydrochloric acid-induced ALI were randomized (n = 9 per group) to 5.5 h NAVA (non-paralyzed), VC (paralyzed; Vt 6-ml/kg), or VC (paralyzed; Vt 15-ml/kg). PEEP was adjusted to hemodynamic goals in NAVA and VC6-ml/kg, and was 1 cmH2O in VC15-ml/kg. MEASUREMENTS AND MAIN RESULTS: PaO2/FiO2; lung wet-to-dry ratio; lung histology; interleukin-8 (IL-8) concentrations in broncho-alveolar-lavage (BAL) fluid, plasma, and non-pulmonary organs; plasminogen activator inhibitor type-1 and tissue factor in BAL fluid and plasma; non-pulmonary organ apoptosis rate; creatinine clearance; echocardiography. PEEP was similar in NAVA and VC6-ml/kg. During NAVA, Vt was lower (3.1 +/- 0.9 ml/kg), whereas PaO2/ FiO2, respiratory rate, and PaCO2 were higher compared to VC6-ml/kg (p<0.05 for all). Variables assessing ventilator-induced lung injury (VILI), IL-8 levels, non-pulmonary organ apoptosis rate, and kidney as well as cardiac performance were similar in NAVA compared to VC6-ml/kg. VILI and non-pulmonary organ dysfunction was attenuated in both groups compared to VC15-ml/kg. CONCLUSIONS: In anesthetized rabbits with early experimental ALI, NAVA is as effective as VC6-ml/kg in preventing VILI, in attenuating excessive systemic and remote organ inflammation, and in preserving cardiac and kidney function.

Coffee consumption attenuates short-term fructose-induced liver insulin resistance in healthy men.

BACKGROUND Epidemiologic and experimental data have suggested that chlorogenic acid, which is a polyphenol contained in green coffee beans, prevents diet-induced hepatic steatosis and insulin resistance. OBJECTIVE We assessed whether the consumption of chlorogenic acid-rich coffee attenuates the effects of short-term fructose overfeeding, dietary conditions known to increase intrahepatocellular lipids (IHCLs), and blood triglyceride concentrations and to decrease hepatic insulin sensitivity in healthy humans. DESIGN Effects of 3 different coffees were assessed in 10 healthy volunteers in a randomized, controlled, crossover trial. IHCLs, hepatic glucose production (HGP) (by 6,6-d2 glucose dilution), and fasting lipid oxidation were measured after 14 d of consumption of caffeinated coffee high in chlorogenic acid (C-HCA), decaffeinated coffee high in chlorogenic acid, or decaffeinated coffee with regular amounts of chlorogenic acid (D-RCA); during the last 6 d of the study, the weight-maintenance diet of subjects was supplemented with 4 g fructose · kg(-1) · d(-1) (total energy intake ± SD: 143 ± 1% of weight-maintenance requirements). All participants were also studied without coffee supplementation, either with 4 g fructose · kg(-1) · d(-1) (high fructose only) or without high fructose (control). RESULTS Compared with the control diet, the high-fructose diet significantly increased IHCLs by 102 ± 36% and HGP by 16 ± 3% and decreased fasting lipid oxidation by 100 ± 29% (all P < 0.05). All 3 coffees significantly decreased HGP. Fasting lipid oxidation increased with C-HCA and D-RCA (P < 0.05). None of the 3 coffees significantly altered IHCLs. CONCLUSIONS Coffee consumption attenuates hepatic insulin resistance but not the increase of IHCLs induced by fructose overfeeding. This effect does not appear to be mediated by differences in the caffeine or chlorogenic acid content. This trial was registered at clinicaltrials.gov as NCT00827450.

[Drug-induced Stevens-Johnson syndrome in a patient with AIDS]

The Stevens-Johnson syndrome is a severe potentially life-threatening form of the erythema multiforme, affecting both skin and mucous membranes. We present a case of a 49-year-old male patient with AIDS who developed a Stevens-Johnson syndrome while being treated with pyrimethamine, sulfadiazine and phenytoin for cerebral toxoplasmosis. Further diagnostic evaluation of this dangerous cutaneous affection may prove difficult for several reasons. In particular, in patients with AIDS who are more susceptible for adverse drug reactions and who are simultaneously receiving a variety of drugs with a considerable potential of cutaneous side effects, therapy cannot be withhold for lack of therapeutic alternatives. Moreover, the low lymphocyte count in this case may have made reliable testing with lymphocyte transformation studies impossible. The evaluation and the differential diagnosis of the drug-induced Stevens-Johnson syndrome are discussed. Especially long- and moderately long-acting sulfonamides belong to the most important agents that can cause a drug-induced Stevens-Johnson syndrome. The pathogenesis and the risk factors for cutaneous hypersensitivity reactions in HIV-infected patients are only poorly understood. These kind of reactions, however, seem to occur more often in patients with a more advanced immunodeficiency.

A new approach to chemotherapy: drug-induced differentiation kills African trypanosomes

Human African trypanosomiasis (sleeping sickness) is a neglected tropical disease caused by Trypanosoma brucei spp. The parasites are transmitted by tsetse flies and adapt to their different hosts and environments by undergoing a series of developmental changes. During differentiation, the trypanosome alters its protein coat. Bloodstream form trypanosomes in humans have a coat of variant surface glycoprotein (VSG) that shields them from the immune system. The procyclic form, the first life-cycle stage to develop in the tsetse fly, replaces the VSG coat by procyclins; these proteins do not protect the parasite from lysis by serum components. Our study exploits the parasite-specific process of differentiation from bloodstream to procyclic forms to screen for potential drug candidates. Using transgenic trypanosomes with a reporter gene in a procyclin locus, we established a whole-cell assay for differentiation in a medium-throughput format. We screened 7,495 drug-like compounds and identified 28 hits that induced expression of the reporter and loss of VSG at concentrations in the low micromolar range. Small molecules that induce differentiation to procyclic forms could facilitate studies on the regulation of differentiation as well as serving as scaffolds for medicinal chemistry for new treatments for sleeping sickness.

p73 regulates basal and starvation-induced liver metabolism in vivo

As a member of the p53 gene family, p73 regulates cell cycle arrest, apoptosis, neurogenesis, immunity and inflammation. Recently, p73 has been shown to transcriptionally regulate selective metabolic enzymes, such as cytochrome c oxidase subunit IV isoform 1, glucose 6-phosphate dehydrogenase and glutaminase-2, resulting in significant effects on metabolism, including hepatocellular lipid metabolism, glutathione homeostasis and the pentose phosphate pathway. In order to further investigate the metabolic effect of p73, here, we compared the global metabolic profile of livers from p73 knockout and wild-type mice under both control and starvation conditions. Our results show that the depletion of all p73 isoforms cause altered lysine metabolism and glycolysis, distinct patterns for glutathione synthesis and Krebs cycle, as well as an elevated pentose phosphate pathway and abnormal lipid accumulation. These results indicate that p73 regulates basal and starvation-induced fuel metabolism in the liver, a finding that is likely to be highly relevant for metabolism-associated disorders, such as diabetes and cancer.

Bok Is Not Pro-Apoptotic But Suppresses Poly ADP-Ribose Polymerase-Dependent Cell Death Pathways and Protects against Excitotoxic and Seizure-Induced Neuronal Injury.

UNLABELLED Bok (Bcl-2-related ovarian killer) is a Bcl-2 family member that, because of its predicted structural homology to Bax and Bak, has been proposed to be a pro-apoptotic protein. In this study, we demonstrate that Bok is highly expressed in neurons of the mouse brain but thatbokwas not required for staurosporine-, proteasome inhibition-, or excitotoxicity-induced apoptosis of cultured cortical neurons. On the contrary, we found thatbok-deficient neurons were more sensitive to oxygen/glucose deprivation-induced injuryin vitroand seizure-induced neuronal injuryin vivo Deletion ofbokalso increased staurosporine-, excitotoxicity-, and oxygen/glucose deprivation-induced cell death inbax-deficient neurons. Single-cell imaging demonstrated thatbok-deficient neurons failed to maintain their neuronal Ca(2+)homeostasis in response to an excitotoxic stimulus; this was accompanied by a prolonged deregulation of mitochondrial bioenergetics.bokdeficiency led to a specific reduction in neuronal Mcl-1 protein levels, and deregulation of both mitochondrial bioenergetics and Ca(2+)homeostasis was rescued by Mcl-1 overexpression. Detailed analysis of cell death pathways demonstrated the activation of poly ADP-ribose polymerase-dependent cell death inbok-deficient neurons. Collectively, our data demonstrate that Bok acts as a neuroprotective factor rather than a pro-death effector during Ca(2+)- and seizure-induced neuronal injuryin vitroandin vivo SIGNIFICANCE STATEMENT Bcl-2 proteins are essential regulators of the mitochondrial apoptosis pathway. The Bcl-2 protein Bok is highly expressed in the CNS. Because of its sequence similarity to Bax and Bak, Bok has long been considered part of the pro-apoptotic Bax-like subfamily, but no studies have yet been performed in neurons to test this hypothesis. Our study provides important new insights into the functional role of Bok during neuronal apoptosis and specifically in the setting of Ca(2+)- and seizure-mediated neuronal injury. We show that Bok controls neuronal Ca(2+)homeostasis and bioenergetics and, contrary to previous assumptions, exerts neuroprotective activitiesin vitroandin vivo Our results demonstrate that Bok cannot be placed unambiguously into the Bax-like Bcl-2 subfamily of pro-apoptotic proteins.

Drug-induced torsades de pointes in an underserved urban population. Methadone: is there therapeutic equipoise?

BACKGROUND Although it has been well established that methadone use can result in prolonged QTc/torsades de pointes (TdP) and has been labeled as one of the main drugs that cause TdP, it is still prescribed indiscriminately, and several cases of methadone-associated TdP have been seen in our community. METHODS Our objective was to determine the associated factors for prolonged QTc and the development of torsades de pointes (TdP) in our underserved patient population. We found 12,550 ECGs with prolonged QTc between 2002 and 2013. Medical records were reviewed in order to identify precipitating factors for prolonged QTc and to detect incidence of TdP. RESULTS We identified 2735 patients with prolonged QTc who met the inclusion criteria. Of these, 89 (3%) experienced TdP. There was a greater prevalence of HIV infection in the TdP group (11.2 vs. 3.7%, p < 0.001). Furosemide, hydrochlorothiazide, selective serotonin reuptake inhibitors (SSRIs), amiodarone, ciprofloxacin, methadone, haloperidol, and azithromycin were the drugs most often associated with prolonged QTc (31, 8.2, 7.6, 7.1, 3.9, 3.4 and 3.3%, respectively). However, the agents most commonly associated with TdP were furosemide (39.3%), methadone (27%), SSRIs (19.1%), amiodarone (18%), and dofetilide (9%). The medications with statistical significance in the multivariate analysis for TdP development in descending order were as follows: ranolazine (odds ratios [OR] = 53.61, 95% confidence interval [CI] 5.4-524, p < 0.001), dofetilide (OR = 25, CI 6.47-103.16, p < 0.001), voriconazole (OR = 21.40, CI 3.24-124.25, p < 0.001), verapamil (OR = 10.98, CI 2.62-44.96, p < 0.001), sotalol (OR = 12.72, 1.95-82.81, p = 0.008), methadone (OR = 9.89, CI 4.05-24.15, p < 0.001), and SSRI (OR = 2.26, CI 1.10-5.96, p < 0.001). This multivariate analysis revealed that amiodarone and HIV infection were not implicated in TdP. CONCLUSION Methadone was by far the leading medication implicated in the development of TdP and an independent predictor in both univariate and multivariate analyses despite the fact that it was not the most common QT-prolonging medication in our population.

[Pharmacotherapy of hyperthyreosis--adverse drug reactions]

The antithyroid drugs mainly include thioimidazole (carbimazole, methimazole=thiamazole) and propylthiouracil. After absorption, carbimazole is rapidly metabolized to methimazole and thus switching between these two drugs should not be considered in case of side effects. Furthermore, in case of side effects, sometimes even cross reactions between thioimidazoles and propylthiouracil occur. Common and typical adverse reactions of antithyroid drugs include dose dependent hypothyroidism and thus thyroid function should be repeatedly checked while the patient is on antithyroid drugs. Furthermore, pruritus and rash may develop. In this case, one might try to switch from thioimidazoles to propylthiouracil or vice versa. Antithyroid drugs may cause mild dose dependent neutropenia or severe allergy-mediated agranulocytosis, which typically occurs during the first three months of treatment, has an incidence of 3 per 10,000 patients and cross reactivity between thioimidazoles to propylthiouracil may occur. Rarely, antithyroid drugs can cause aplastic anemia. Mainly propylthiouracil, but sometimes also methimazole may lead to an asymptomatic transient increase in liver enzymes or to severe, even lethal liver injury of cholestatic or hepatocellular pattern. Since propylthiouracil associated liver injury was observed increasingly among children and adolescent, it has been suggested to prefer thioimidazoles for these patients. Because of these potential serious adverse effects, physicians should advise patients to immediately seek medical help if they get a fever or sore throat or malaise, abdominal complaints or jaundice, respectively. Furthermore, arthralgias may develop in 1-5% of patients under both antithyroid drugs. Since arthralgias may be the first symptom of more serious immunologic side effects, it is recommended to stop the antithyroid drug in this case. Drug induced polyarthritis mainly develops during the first month of therapy, whereas ANCA-positive vasculitis is generally observed only after long term exposure to propylthiouracil or very rarely with the thioimidazoles. The teratogenic risk of the thioimidazoles is somewhat higher (Aplasia cutis congenita), that is why one generally recommends preferring propylthiouracil during pregnancy. During breast feeding both, thioimidazoles or propylthiouracil, may be administered. Nowadays, perchlorate is only used short term in case of latent hyperthyroidism before administering iodine-containing contrast agents. Therefore, the known side effects, which usually are only observed after long term treatment, are not an issue any more.

Reduced serum chemerin in patients with more severe liver cirrhosis

Chemerin is a well-established modulator of immune cell function and its serum levels are induced in inflammatory diseases. Liver cirrhosis is associated with inflammation which is aggravated by portal hypertension. The objective of this study was to evaluate whether chemerin is induced in patients with more severe liver cirrhosis and portal hypertension. Chemerin has been measured by ELISA in the portal venous serum (PVS), systemic venous serum (SVS) and hepatic venous serum (HVS) of 45 patients with liver cirrhosis. Chemerin is higher in HVS compared to PVS in accordance with our recently published finding. SVS, HVS and PVS chemerin decline in patients with more advanced liver injury defined by the CHILD-PUGH score. Hepatic chemerin has been determined in a small cohort and is similarly expressed in normal and cirrhotic liver. MELD score and serum markers of liver and kidney function do not correlate with chemerin. There is a positive correlation of chemerin in all compartments with Quick prothrombin time and of SVS chemerin with systolic blood pressure. PVS chemerin is induced in patients with modest/massive ascites but this does not translate into higher HVS and SVS levels. Chemerin is not associated with variceal size. Reduction of portal pressure by transjugular intrahepatic portosystemic shunt does not affect chemerin levels. These data show that low chemerin in patients with more severe liver cirrhosis is associated with reduced Quick prothrombin time.

Non-coding keratin variants associate with liver fibrosis progression in patients with hemochromatosis

Background Keratins 8 and 18 (K8/K18) are intermediate filament proteins that protect the liver from various forms of injury. Exonic K8/K18 variants associate with adverse outcome in acute liver failure and with liver fibrosis progression in patients with chronic hepatitis C infection or primary biliary cirrhosis. Given the association of K8/K18 variants with end-stage liver disease and progression in several chronic liver disorders, we studied the importance of keratin variants in patients with hemochromatosis. Methods The entire K8/K18 exonic regions were analyzed in 162 hemochromatosis patients carrying homozygous C282Y HFE (hemochromatosis gene) mutations. 234 liver-healthy subjects were used as controls. Exonic regions were PCR-amplified and analyzed using denaturing high-performance liquid chromatography and DNA sequencing. Previously-generated transgenic mice overexpressing K8 G62C were studied for their susceptibility to iron overload. Susceptibility to iron toxicity of primary hepatocytes that express K8 wild-type and G62C was also assessed. Results We identified amino-acid-altering keratin heterozygous variants in 10 of 162 hemochromatosis patients (6.2%) and non-coding heterozygous variants in 6 additional patients (3.7%). Two novel K8 variants (Q169E/R275W) were found. K8 R341H was the most common amino-acid altering variant (4 patients), and exclusively associated with an intronic KRT8 IVS7+10delC deletion. Intronic, but not amino-acid-altering variants associated with the development of liver fibrosis. In mice, or ex vivo, the K8 G62C variant did not affect iron-accumulation in response to iron-rich diet or the extent of iron-induced hepatocellular injury. Conclusion In patients with hemochromatosis, intronic but not exonic K8/K18 variants associate with liver fibrosis development.

CYP2E1 genotype and isoniazid-induced hepatotoxicity in patients treated for latent tuberculosis

OBJECTIVE: To determine whether pharmacogenetic tests such as N-acetyltransferase 2 (NAT2) and cytochrome P450 2E1 (CYP2E1) genotyping are useful in identifying patients prone to antituberculosis drug-induced hepatotoxicity in a cosmopolite population. METHODS: In a prospective study we genotyped 89 patients treated with isoniazid (INH) for latent tuberculosis. INH-induced hepatitis (INH-H) or elevated liver enzymes including hepatitis (INH-ELE) was diagnosed based on the clinical diagnostic scale (CDS) designed for routine clinical practice. NAT2 genotypes were assessed by fluorescence resonance energy transfer probe after PCR analysis, and CYP2E1 genotypes were determined by PCR with restriction fragment length polymorphism analysis. RESULTS: Twenty-six patients (29%) had INH-ELE, while eight (9%) presented with INH-H leading to INH treatment interruption. We report no significant influence of NAT2 polymorphism, but we did find a significant association between the CYP2E1 *1A/*1A genotype and INH-ELE (OR: 3.4; 95% CI:1.1-12; p = 0.02) and a non significant trend for INH-H (OR: 5.9; 95% CI: 0.69-270; p = 0.13) compared with other CYP2E1 genotypes. This test for predicting INH-ELE had a positive predictive value (PPV) of 39% (95% CI: 26-54%) and a negative predictive value (NPV) of 84% (95% CI: 69-94%). CONCLUSION: The genotyping of CYP2E1 polymorphisms may be a useful predictive tool in the common setting of a highly heterogeneous population for predicting isoniazid-induced hepatic toxicity. Larger prospective randomized trials are needed to confirm these results.

Liver repopulation with bone marrow derived cells improves the metabolic disorder in the Gunn rat

BACKGROUND: Reversible ischaemia/reperfusion (I/R) liver injury has been used to induce engraftment and hepatic parenchymal differentiation of exogenous beta2-microglubulin(-)/Thy1(+) bone marrow derived cells. AIM: To test the ability of this method of hepatic parenchymal repopulation, theoretically applicable to clinical practice, to correct the metabolic disorder in a rat model of congenital hyperbilirubinaemia. METHODS AND RESULTS: Analysis by confocal laser microscopy of fluorescence labelled cells and by immunohistochemistry for beta2-microglubulin, 72 hours after intraportal delivery, showed engraftment of infused cells in liver parenchyma of rats with I/R, but not in control animals with non-injured liver. Transplantation of bone marrow derived cells obtained from GFP-transgenic rats into Lewis rats resulted in the presence of up to 20% of GFP positive hepatocytes in I/R liver lobes after one month. The repopulation rate was proportional to the number of transplanted cells. Infusion of GFP negative bone marrow derived cells into GFP positive transgenic rats resulted in the appearance of GFP negative hepatocytes, suggesting that the main mechanism underlying parenchymal repopulation was differentiation rather than cell fusion. Transplantation of wild type bone marrow derived cells into hyperbilirubinaemic Gunn rats with deficient bilirubin conjugation after I/R damage resulted in 30% decrease in serum bilirubin, the appearance of bilirubin conjugates in bile, and the expression of normal UDP-glucuronyltransferase enzyme evaluated by polymerase chain reaction. CONCLUSIONS: I/R injury induced hepatic parenchymal engraftment and differentiation into hepatocyte-like cells of bone marrow derived cells. Transplantation of bone marrow derived cells from non-affected animals resulted in the partial correction of hyperbilirubinaemia in the Gunn rat.

The vascular ectonucleotidase CD39 is permissive for sinusoidal endothelial cell proliferation during liver regeneration: evidence for synergism between growth factors and extracellular nucleotides

Crosstalk between elements of the sinusoidal vasculature, platelets and hepatic parenchymal cells influences regenerative responses to liver injury and/or resection. Such paracrine interactions include hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), IL-6 and small molecules such as serotonin and nucleotides. CD39 (nucleoside triphosphate diphosphohydrolase-1) is the dominant vascular ectonucleotidase expressed on the luminal surface of endothelial cells and modulates extracellular nucleotide signaling. We have previously shown that integrity of P2-receptors, as maintained by CD39, is required for angiogenesis in Matrigel plugs in vivo and that there is synergism between nucleotide P2-receptor- and growth factor-mediated cell proliferation in vitro. We have now explored effects of CD39 on liver regeneration and vascular endothelial growth factor responses in a standard small animal model of partial hepatectomy. The expression of CD39 on liver sinusoidal endothelial cells (LSEC) is substantially boosted during liver regeneration. This transcriptional upregulation precedes maximal sinusoidal endothelial cell proliferation, noted at day 5-8 in C57BL6 wild type mice. In matched mutant mice null for CD39 (n=14), overall survival is decreased to 71% by day 10. Increased lethality occurs as a consequence of extensive LSEC apoptosis, decreased endothelial proliferation and failure of angiogenesis leading to hepatic infarcts and regenerative failure in mutant mice. This aberrant vascular remodeling is associated with biochemical liver injury, elevated serum levels of VEGF (113.9 vs. 65.5pg/ml, p=0.013), and decreased circulating HGF (0.89 vs. 1.43 ng/ml, p=0.001) in mice null for CD39. In agreement with these observations, wild type LSEC but not CD39 null cultures upregulate HGF expression and secretion in response to exogenous VEGF in vitro. CD39 null LSEC cultures show poor proliferation responses and heightened levels of apoptosis when contrasted to wild type LSEC where agonists of P2Y receptors augment cell proliferation in the presence of growth factors. These observations are associated with features of P2Y-desensitization, normal levels of the receptor tyrosine kinase VEGFR-1 (Flt-1) and decreased expression of VEGFR-2 (FLK/KDR) in CD39 null LSEC cultures. We provide evidence that CD39 and extracellular nucleotides impact upon growth factor responses and tyrosine receptor kinases during LSEC proliferation. We propose that CD39 expression by LSEC might co-ordinate angiogenesis-independent liver protection by facilitating VEGF-induced paracrine release of HGF to promote vascular remodeling in liver regeneration.

Death receptor 5 mediated-apoptosis contributes to cholestatic liver disease

Chronic cholestasis often results in premature death from liver failure with fibrosis; however, the molecular mechanisms contributing to biliary cirrhosis are not demonstrated. In this article, we show that the death signal mediated by TNF-related apoptosis-inducing ligand (TRAIL) receptor 2/death receptor 5 (DR5) may be a key regulator of cholestatic liver injury. Agonistic anti-DR5 monoclonal antibody treatment triggered cholangiocyte apoptosis, and subsequently induced cholangitis and cholestatic liver injury in a mouse strain-specific manner. TRAIL- or DR5-deficient mice were relatively resistant to common bile duct ligation-induced cholestasis, and common bile duct ligation augmented DR5 expression on cholangiocytes, sensitizing mice to DR5-mediated cholangitis. Notably, anti-DR5 monoclonal antibody-induced cholangitis exhibited the typical histological appearance, reminiscent of human primary sclerosing cholangitis. Human cholangiocytes constitutively expressed DR5, and TRAIL expression and apoptosis were significantly elevated in cholangiocytes of human primary sclerosing cholangitis and primary biliary cirrhosis patients. Thus, TRAIL/DR5-mediated apoptosis may substantially contribute to chronic cholestatic disease, particularly primary sclerosing cholangitis.