Chlorotyrosine protein adducts are reliable biomarkers of neutrophil-induced cytotoxicity in vivo

INTRODUCTION:A limitation for investigating the pathophysiological role of neutrophils in vivo is the lack of a reliable biomarker for neutrophil cytotoxicity in the liver. Therefore, we investigated if immunohistochemical detection of chlorotyrosine protein adducts can be used as a specific footprint for generation of neutrophil-derived hypochlorous acid in vivo.METHODS:C3Heb/FeJ mice were treated with 100 micrograms/kg endotoxin (ET) alone or in combination with 700 mg/kg galactosamine (Gal/ET). Some animals received additionally two doses of 10 mg/kg of the pancaspase inhibitor Z-VAD-fmk. An antibody against chlorotyrosine was used for the immunohistochemical analysis.RESULTS:At 6 h after Gal/ET, hepatocellular apoptosis was evident without increase in plasma ALT activities. Neutrophils accumulated in sinusoids but there was no evidence for chlorotyrosine staining. At 7 h after Gal/ET, about 54% of the sequestered neutrophils had extravasated, there was extensive necrosis and increased plasma ALT activities. Extensive immunostaining for chlorotyrosine, mainly colocalized with neutrophils, could be observed. Treatment with Z-VAD-fmk eliminated apoptosis, necrosis and the increase in plasma ALT values. Neutrophil extravasation was prevented but the overall number of neutrophils in the liver was unchanged. Chlorotyrosine staining was absent in these samples. After ET alone (7 h), sinusoidal neutrophil accumulation was similar to Gal/ET treatment but there was no apoptosis, neutrophil extravasation, ALT release or chlorotyrosine staining.CONCLUSIONS:Chlorotyrosine staining in liver samples correlated well with evidence of neutrophil-induced liver injury in the endotoxemia model. These results indicate that assessment of chlorotyrosine protein adduct formation by immunohistochemistry could be a useful marker of neutrophil-induced liver cell injury in vivo.This item is part of the UA Faculty Publications collection. For more information this item or other items in the UA Campus Repository, contact the University of Arizona Libraries at [email protected]

METABOLISM OF 4-NITROANILINE BY RAT LIVER MICROSOMES

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Proinsulin Atypical Maturation and Disposal Induces Extensive Defects in Mouse Ins2+/Akita β-Cells

Because of its low relative folding rate and plentiful manufacture in β-cells, proinsulin maintains a homeostatic balance of natively and plentiful non-natively folded states (i.e., proinsulin homeostasis, PIHO) through the integration of maturation and disposal processes. PIHO is susceptible to genetic and environmental influences, and its disorder has been critically linked to defects in β-cells in diabetes. To explore this hypothesis, we performed polymerase chain reaction (PCR), metabolic-labeling, immunoblotting, and histological studies to clarify what defects result from primary disorder of PIHO in model Ins2+/Akita β-cells. We used T antigen-transformed Ins2+/Akita and control Ins2+/+ β-cells established from Akita and wild-type littermate mice. In Ins2+/Akita β-cells, we found no apparent defect at the transcriptional and translational levels to contribute to reduced cellular content of insulin and its precursor and secreted insulin. Glucose response remained normal in proinsulin biosynthesis but was impaired for insulin secretion. The size and number of mature insulin granules were reduced, but the size/number of endoplasmic reticulum, Golgi, mitochondrion, and lysosome organelles and vacuoles were expanded/increased. Moreover, cell death increased, and severe oxidative stress, which manifested as increased reactive oxygen species, thioredoxin-interacting protein, and protein tyrosine nitration, occurred in Ins2+/Akita β-cells and/or islets. These data show the first clear evidence that primary PIHO imbalance induces severe oxidative stress and impairs glucose-stimulated insulin release and β-cell survival as well as producing other toxic consequences. The defects disclosed/clarified in model Ins2+/Akita β-cells further support a role of the genetic and stress-susceptible PIHO disorder in β-cell failure and diabetes

Fludarabine, cytarabine, granulocyte colony-stimulating factor, and idarubicin with gemtuzumab ozogamicin improves event-free survival in younger patients with newly diagnosed aml and overall survival in patients with npm1 and flt3 mutations

Purpose To determine the optimal induction chemotherapy regimen for younger adults with newly diagnosed AML without known adverse risk cytogenetics. Patients and Methods One thousand thirty-three patients were randomly assigned to intensified (fludarabine, cytarabine, granulocyte colony-stimulating factor, and idarubicin [FLAG-Ida]) or standard (daunorubicin and Ara-C [DA]) induction chemotherapy, with one or two doses of gemtuzumab ozogamicin (GO). The primary end point was overall survival (OS). Results There was no difference in remission rate after two courses between FLAG-Ida + GO and DA + GO (complete remission [CR] + CR with incomplete hematologic recovery 93% v 91%) or in day 60 mortality (4.3% v 4.6%). There was no difference in OS (66% v 63%; P = .41); however, the risk of relapse was lower with FLAG-Ida + GO (24% v 41%; P < .001) and 3-year event-free survival was higher (57% v 45%; P < .001). In patients with an NPM1 mutation (30%), 3-year OS was significantly higher with FLAG-Ida + GO (82% v 64%; P = .005). NPM1 measurable residual disease (MRD) clearance was also greater, with 88% versus 77% becoming MRD-negative in peripheral blood after cycle 2 (P = .02). Three-year OS was also higher in patients with a FLT3 mutation (64% v 54%; P = .047). Fewer transplants were performed in patients receiving FLAG-Ida + GO (238 v 278; P = .02). There was no difference in outcome according to the number of GO doses, although NPM1 MRD clearance was higher with two doses in the DA arm. Patients with core binding factor AML treated with DA and one dose of GO had a 3-year OS of 96% with no survival benefit from FLAG-Ida + GO. Conclusion Overall, FLAG-Ida + GO significantly reduced relapse without improving OS. However, exploratory analyses show that patients with NPM1 and FLT3 mutations had substantial improvements in OS. By contrast, in patients with core binding factor AML, outcomes were excellent with DA + GO with no FLAG-Ida benefit

Lithium/magnesium oxide catalyst and method of making

An improved method for preparing a catalyst which is superior for converting methane to ethane and ethylene is described. The method involves mixing a solution of a magnesium alkoxide in alcohol with a solution of a lithium compound in alcohol. Preferably, chlorine is introduced into the mixture. A solution of an aluminum alkoxide in an alcohol may also be added to the mixture. The magnesium alkoxide is hydrolyzed to produce a gel, and the gel is then calcined to produce the catalyst. Catalysts prepared by this method are superior for converting methane to ethane and ethylene, and have superior selectivities for ethylene and ethane over conventional lithium carbonate/magnesium oxide catalysts.U

Send 1I I90 1-0 I84503.00/0 DRUG M ETA HOlISM MECHANISM OF ACETAMINOPHEN-STIMULATED NADPH OXIDATION CATALYZED BY THE PEROXIDASE-H202 SYSTEM

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