Pandemic H1N1 (2009) and renal failure: the experience of the Irish national tertiary referral centre.

INTRODUCTION: H1N1 influenza A, was first described in April 2009. A significant cohort of patients from this outbreak developed acute respiratory distress syndrome or pneumonia. H1N1 has since been transmitted across the world. Little has been described on the renal complications of this illness. METHODS: A retrospective review of all patients admitted to our institution with H1N1 infection was carried out from July to November 2009. Renal biochemistry, need for renal replacement therapy and hospital outcome was recorded. RESULTS: Thirty-four patients with H1N1 were admitted. Average length of admission was 10 days (3-84). Eleven patients (32%) developed acute kidney injury (AKI) as defined by the RIFLE criteria (creatinine range 120-610). Four patients required renal replacement therapy, for a range of 10-52 days. Seven patients developed AKI that responded to volume resuscitation. The commonest cause of AKI was sepsis with acute tubular necrosis. CONCLUSION: This study highlights the significance and frequency of renal complications associated with this illness.

Modulation of the mutagenicity of three dinitropyrene isomers in vitro by rat-liver S9, cytosolic, and microsomal fractions following chronic ethanol ingestion.

The effects of chronic ethanol feeding of rats on the ability of liver fractions to modulate the bacterial mutagenicity of three dinitropyrene isomers (1,3-, 1,6- and 1,8-DNP), which require bacterial enzymes but not an exogenous enzyme source for activation, were studied. The mutagenicity of the DNP isomers toward S. typhimurium TA98 and TA100 was attenuated in the presence of post-mitochondrial supernatants (S9) from both ethanol-fed and pair-fed rats albeit, that from the ethanol-fed group was more efficient in lowering the mutagenicity. The cytosolic fraction from ethanol-fed rats enhanced the mutagenicity of all of the DNP isomers in TA100. The most notable enhancement was with 1,3-DNP in which a more than 4-fold enhancement was obtained. Cytosol from pair-fed rats enhanced only the mutagenicity of 1,3-DNP, this by 2.9-fold. Cytosolic NADPH-nitroreductase activity from ethanol-treated rats toward 1,6-, 1,8- and 1,3-DNP was increased 2.8-, 1.7- and 1.3-fold, respectively over pair-fed controls. Cytosolic NADH-nitroreductase from ethanol-fed rats was increased with 1,3-DNP (1.7-fold) and 1,8-DNP (1.4-fold) as substrates, but not with 1,6-DNP. Microsomes decreased the mutagenicity of DNP similarly to S9, i.e., fractions from ethanol-fed rats were more efficient than those of pair-fed rats in deactivating all the DNP isomers. Per mg of protein, detoxification of DNP by S9 was more efficient than with microsomes, thus both cytosolic and microsomal enzymes are required for maximal detoxification. In summary, ethanol feeding modulates both the augmented cytosolic activation of DNP to mutagens and the deactivation of the direct-acting mutagenicity of DNP by microsomes. In combination, as is the case with S9, the microsomal detoxifying activity outcompetes the cytosolic activation.

Arylamine activation following chronic ethanol ingestion by rats: studies on the liver S9, microsomal and cytosolic fractions and comparison with Aroclor 1254 pretreatment.

That enzyme fractions derived from animals chronically fed alcohol can alter the metabolism of carcinogenic xenobiotic compounds has been documented. To further understand this relationship the mutagenicity of 3 aromatic amines was determined in the Ames test, employing activation systems derived from rats maintained on an alcohol-containing liquid diet, an isocaloric control liquid diet or Aroclor 1254-pretreated animals fed standard laboratory chow. Depending upon protein and substrate concentrations, S9 from ethanol-fed rats was 30-50% less efficient than S9 from pair-fed rats in activating arylamines (2-aminofluorene, 2-aminoanthracene and 2-acetylaminofluorene) to mutagens in Salmonella typhimurium TA98 and TA100. Cytosolic fractions from ethanol-fed animals always resulted in greater arylamine activation than that of controls whereas the opposite was true of the microsomal compartment in which the ethanol-treated group was consistently less active than the controls. The cytosolic N-acetyltransferase activities with respect to 2 different substrates, isoniazid and 2-aminofluorene, were unaffected by ethanol consumption, indicating that this activity probably does not account for the different activation profiles exhibited by the ethanol and pair-fed cytosolic systems. Both the cytosolic and microsomal compartments are required for maximal expression of the mutagenicity of each arylamine however, each compartment can activate arylamines independently of the other. Reconstituting cytosol with microsomes from ethanol- and pair-fed rats, but not Aroclor-pretreated rats, resulted in a synergistic activation of the aromatic amines and displayed an effect similar to that of S9. Compared to Aroclor pretreatment and pair-fed controls, microsomes from ethanol-fed rats displayed the least capacity for activating any of the arylamines to mutagens. Microsomes from Aroclor-pretreated rats accounted for at least 80% of the S9-mediated activation of each of the arylamines to mutagenic metabolites which was in marked contrast to the contribution of the microsomal fractions to the S9 activity in the ethanol- (5-20% of S9 activity) and pair-fed systems (22-30% of S9 activity). The data indicate that 2 opposing reactions occur in S9, a cytosolic activity that augments and a microsomal activity that attenuates the mutagenicity of arylamines. Both activities are modified by ethanol consumption and Aroclor pretreatment.

Phosphorylase ratio and susceptibility to malignant hyperthermia.

The ratio of muscle phosphorylase a to total phosphorylase, expressed as a percent, was determined in vastus lateralis muscle of 26 patients to examine the efficacy of this parameter as a method for screening for susceptibility to malignant hyperthermia (MH). As standard screening, all patients also had muscle contracture responses determined to 2% halothane and 0.25-32 mM caffeine at 37 degrees C. Each drug was given separately and not combined. Nine patients were susceptible to MH, based upon caffeine threshold of 2 mM or less (seven patients) or a rapidly developing contracture tension to halothane of more than 400 mg (seven patients, including five with positive caffeine responses). Mean phosphorylase ratio in these nine patients was 14.5 +/- 2.0% (mean, SEM). In the 17 nonsusceptible patients mean phosphorylase ratio (12.4 +/- 1.9%) was not significantly different. The range of phosphorylase ratios in susceptible patients was 6.5-26% while 13 nonsusceptible patients had ratios greater than 6% and up to 29%. The unacceptably high number of false-positive responses in nonsusceptible patients precludes the use of phosphorylase ratio as a definitive diagnostic test.