Acute kidney injury model established by systemic glutathione depletion in mice

Glutathione (GSH) is one of the most extensively studied tripeptides. The roles for GSH in redox signaling, detoxification of xenobiotics and antioxidant defense have been investigated. A drug‐induced rhabdomyolysis mouse model was recently established in L‐buthionine‐(S,R)‐sulfoximine (BSO; a GSH synthesis inhibitor)‐treated normal mice by co‐administration of antibacterial drug and statin. In these models, mild kidney injury was observed in the BSO only‐treated mice. Therefore, in this study, we studied kidney injury in the GSH‐depleted mouse. BSO was intraperitoneally administered twice a day for 7 days to normal mice. The maximum level of plasma creatine phosphokinase (351 487 ± 53 815 U/L) was shown on day 8, and that of aspartate aminotransferase was shown on day 6. Increased levels of blood urea nitrogen, plasma creatinine, urinary kidney injury molecule‐1 and urinary creatinine were observed. An increase of mRNA expression level of renal lipocalin 2/neutrophil gelatinase‐associated lipocalin was observed. Degeneration and necrosis in the skeletal muscle and high concentrations of myoglobin (Mb) in blood (347‐203 925 ng/mL) and urine (2.5‐68 583 ng/mL) with large interindividual variability were shown from day 5 of BSO administration. Mb‐stained regions in the renal tubule and renal cast were histologically observed. In this study, the GSH‐depletion treatment established an acute kidney injury mouse model due to Mb release from the damaged skeletal muscle. This mouse model would be useful for predicting potential acute kidney injury risks in non‐clinical drug development.     

Continuous illumination through larval development suppresses dopamine synthesis in the suprachiasmatic nucleus, causing activation of α-MSH synthesis in the pituitary and abnormal metamorphic skin pigmentation in flounder

In order to better understand the endocrine aberrations related to abnormal metamorphic pigmentation that appear in flounder larvae reared in tanks, this study examined the effects of continuous 24-h illumination (LL) through larval development on the expression of tyrosine hydroxylase-1 (th1), proopiomelanocortin (pomc), α-melanophore-stimulating hormone (α-MSH) and melanin concentrating hormone (MCH), which are known to participate in the control of background adaptation of body color. We observed two conspicuous deviations in the endocrine system under LL when compared with natural light conditions (LD). First, LL severely suppressed th1 expression in the dopaminergic neurons in the anterior diencephalon, including the suprachiasmatic nucleus (SCN). Second, pomc and α-MSH expression in the pars intermedia melanotrophs was enhanced by LL. Skin color was paler under LL than LD before metamorphic pigmentation, and abnormal metamorphic pigmentation occurred at a higher ratio in LL. We therefore hypothesize that continuous LL inhibited dopamine synthesis in the SCN, which resulted in up-regulation of pomc mRNA expression in the melanotrophs. In spite of the up-regulation of pomc in the melanotrophs, larval skin was adjusted to be pale by MCH which was not affected by LL. Accumulation of α-MSH in the melanotrophs is caused by uncoupling of α-MSH synthesis and secretion due to inhibitory role of MCH on α-MSH secretion, which results in abnormal metamorphic pigmentation by affecting differentiation of adult-type melanophores. Our data demonstrate that continuous illumination at the post-embryonic stage has negative effects on the neuroendocrine system and pituitary in flounder.     

Clinical evaluation of peginterferon α plus ribavirin for patients co-infected with HIV and HCV at Nagoya Medical Center

At Nagoya Medical Center, 10 patients co-infected with HIV and HCV received peginterferon α (PEG-IFNα) plus ribavirin therapy. Three of the cases were HCV genotype 1b, 2 cases were HCV 3b, and 1 case each were 2b, 2c, 3a, 4a and 6n. Nine patients received anti HIV therapy from the beginning. In 5 of these patients, anti HIV therapy was modified when PEG-IFNα plus ribavirin treatment was started. Of the above, 7 patients completed the protocol. No patients had severe adverse effects. Sustained virological response was achieved in 1 of 4 (25%) of the patients with genotypes 1 or 4, and in 5 of 6 (83%) of the patients with other genotypes. PEG-IFNα plus ribavirin therapy is considered a safe and efficacious treatment for patients co-infected with HIV and HCV.