Analysis of N1‐acetyl‐N2‐formyl‐5‐methoxykynuramine/N1‐acetyl‐5‐methoxy‐kynuramine formation from melatonin in mice

Abstract: The interactions of melatonin, a potent endogenous antioxidant, with reactive oxygen species generate several products that include N¹‐acetyl‐N²‐formyl‐5‐methoxykynuramine (AFMK) and N¹‐acetyl‐5‐methoxy‐kynuramine (AMK). The physiological or pathological significance of AFMK/AMK formation during the process of melatonin metabolism in mammals has not been clarified. Using a metabolomic approach in the current study, the AFMK/AMK pathway was thoroughly investigated both in mice and humans. Unexpectedly, AFMK and AMK were not identified in the urine of humans nor in the urine, feces or tissues (including liver, brain, and eyes) in mice under the current experimental conditions. Metabolomic analysis did identify novel metabolites of AMK, i.e. hydroxy‐AMK and glucuronide‐conjugated hydroxy‐AMK. These two newly identified metabolites were, however, not found in the urine of humans. In addition, oxidative stress induced by acetaminophen in the mouse model did not boost AFMK/AMK formation. These data suggest that AFMK/AMK formation is not a significant pathway of melatonin disposition in mice, even under conditions of oxidative stress.     

Considerations of a One‐and‐One‐Half Ventricle Repair in a 47‐Year‐Old Patient

This report describes the management of a 47‐year‐old patient with Ebstein's anomaly and severe right ventricular dysfunction. Her complicated postoperative course is discussed. In addition, age‐related differences in the hemodynamic response to a one‐and‐one‐half ventricle repair are reviewed.     

Periplogenin‐3‐O‐ ‐D‐Glucopyranosyl ‐(1→6)‐ ‐D‐Glucopyaranosyl‐ ‐(1→4) ‐D‐Cymaropyranoside,Isolated from Aegle marmelos Protects Doxorubicin Induced Cardiovascular Problems and Hepatotoxicity in Rats

Doxorubicin is a common chemotherapeutic anticancer drug. Its use is associated with adverse effects including cardiotoxicity. Several therapeutics interventions have been attempted to reduce the toxicity and to improve the efficacy of the drug. However, on phytochemicals very few investigations have been made. In the present study we have evaluated the potential of a cardenolide, periplogenin, isolated from the leaves of Aegle marmelos in protecting the doxorubicin induced cardiotoxicity and lipid peroxidation (LPO) in rats. Doxorubicin induced cardiac and hepatotoxicity were characterized by marked biochemical changes including an increase in serum creatine kinase–MB (CK–MB), glutamate‐pyruvate transaminase (SGPT), and tissue LPO, with a decrease in superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH). It also increased the levels of different serum lipids, but decreased the amount of high‐density lipoprotein (HDL). Cotherapy of the test cardenolide and doxorubicin for 4 weeks reversed all these adverse effects. However, out of three different concentrations (12.5, 25, and 50 mg/kg p.o.) of the test periplogenin, 25 mg/kg appeared to be most effective. When its efficacy was compared with that of vitamin E (α‐tocopherol) the isolated compound exhibited a better therapeutic potential. The isolated periplogenin from the leaves of A. marmelos could potentially inhibit doxorubicin‐induced cardiovascular problems in rats. However, its moderate dose was found to be most effective.     

Effects of 1‐O‐hexyl‐2,3,5‐trimethylhydroquinone on carbon tetrachloride‐induced hepatic cirrhosis in rats

Aim: The present study was undertaken to evaluate the effects of 1‐O‐hexyl‐2,3,5‐trimethylhydroquinone (HTHQ), a synthesized vitamin E derivative, on carbon tetrachloride (CCl₄)‐induced cirrhosis. Methods: Rats were treated with hypodermic injections of CCl₄ twice a week to induce the hepatic cirrhosis, and given drinking water containing HTHQ or solvent. Primary cultures of rat hepatocytes were performed to evaluate the effects of HTHQ on the expression of inducible nitric oxide synthase (iNOS). Results: Masson's staining of rat livers showed fibrosis around pseudo‐lobules in the CCl₄ group, the lesions being reduced in the CCl₄ HTHQ group. Increases in liver tissue hydroxyproline and α₁(I) collagen, α‐smooth muscle actin and iNOS induced by CCl₄, were also markedly diminished by HTHQ. Furthermore, both HTHQ and vitamin E attenuated interleukin‐1β‐induced iNOS protein expression in cultured hepatocytes, the potency of HTHQ being 10‐times higher than that of vitamin E. Conclusion: HTHQ may inhibit development of hepatic cirrhosis in rats, more potently than vitamin E, by inhibiting the iNOS expression in hepatocytes. Because vitamin E has a radical scavenging action, roles of NO and peroxynitrite will be discussed in the effects of HTHQ on the fibrosis.     

Point‐of‐care testing in haemostasis

Point‐of‐care testing (POCT) in haematology has seen a significant increase in both the spectrum of tests available and the number of tests performed annually. POCT is frequently undertaken with the belief that this will reduce the turnaround time for results and so improve patient care. The most obvious example of POCT in haemostasis is the out‐of‐hospital monitoring of the International Normalized Ratio in patients receiving a vitamin K antagonist, such as warfarin. Other areas include the use of the Activated Clotting Time to monitor anticoagulation for patients on cardio‐pulmonary bypass, platelet function testing to identify patients with apparent aspirin or clopidogrel resistance and thrombelastography to guide blood product replacement during cardiac and hepatic surgery. In contrast to laboratory testing, POCT is frequently undertaken by untrained or semi‐trained individuals and in many cases is not subject to the same strict quality control programmes that exist in the central laboratory. Although external quality assessment programmes do exist for some POCT assays these are still relatively few. The use of POCT in haematology, particularly in the field of haemostasis, is likely to expand and it is important that systems are in place to ensure that the generated results are accurate and precise.     

Efficacy of short‐term dexamethasone therapy in acute‐on‐chronic pre‐liver failure

Aim: Acute‐on‐chronic pre‐liver failure (pre‐ACLF) is defined as a severe acute episode of chronic hepatitis B characterized by serum bilirubin of 171 µmol/L or more, alanine aminotransferase of five times or more the upper limit of normal and prothrombin activity of more than 40%, having a potential for progression to acute‐on‐chronic liver failure (ACLF). This study is to evaluate the efficacy of short‐term dexamethasone in pre‐ACLF. Methods: One hundred and seventy patients were assigned to dexamethasone therapy and control group at a ratio of 1:2. For the two groups, we compared biochemical indicators, the incidence of ACLF and mortality. The influential factors on the mortality of patients with pre‐ACLF were studied by Cox proportional hazards models. Results: The significantly lower incidence of ACLF and higher survival rate were observed in patients on dexamethasone therapy (8.9%, 96.4%, respectively) than in control patients (70.2%, 52.6%, respectively; P < 0.001). Dexamethasone treatment was an independent factor influencing the survival rate (P < 0.001, odds ratio = 0.055, 95% confidence interval = 0.013–0.225). During 4 weeks of treatment, serum bilirubin levels of survival patients were significantly lower in the dexamethasone group than control group. Conclusion: Five‐day dexamethasone therapy is effective in improving the liver function and survival rate of patients with pre‐ACLF.     

Adenoma‐like and non‐adenoma‐like dysplasia‐associated lesion or mass in ulcerative colitis

Ulcerative colitis (UC) patients have an increased risk of colorectal cancer. UC has two general patterns of dysplasia, which are commonly classified as adenoma‐like dysplasia‐associated lesion or mass (DALM) and non‐adenoma‐like DALM. The latter has a high risk of concurrent malignancy and often requires a colectomy. Unfortunately, non‐adenoma‐like DALMs sometimes have endoscopic features similar to those of adenoma‐like DALMs. Therefore, new endoscopic techniques to distinguish between these two kinds of DALM have been proposed.     

N‐Methyl‐d‐Aspartate Induces Cortical Hyperemia through Cortical Spreading Depression‐Dependent and ‐Independent Mechanisms in Rats

Objective: N‐methyl‐d ‐aspartate (NMDA) is a powerful cerebrovascular dilator in vivo. Cortical spreading depression (CSD) has recently been shown to contribute to the pial arteriolar dilation in mice. Our main aim was to examine the participation of CSD in the overall cerebrovascular response to NMDA in the rat. Methods: Anesthetized Wistar rats (eight weeks old) were equipped with a closed cranial window to allow topical application of NMDA (10^?5–10^?3 M) to the parietal cortex. Cortical blood flow (CoBF) under and outside the cranial window was simultaneously monitored by using a two‐channel laser‐Doppler flowmeter. CSDs were detected by recording the changes in the cortical DC potential. Results: Concentrations of 10^?4 and 10^?3 M of NMDA evoked single CSDs associated with rapid, transient hyperemia, followed by a sustained, but reduced, increase in CoBF. The latency and magnitude of the CoBF responses were dose dependent. The higher dose resulted in shorter latency (100±5* vs. 146±11 seconds, *P<0.05; mean±standard error of the mean) and larger overall flow response (77±12* vs. 28±3% from baseline) under, but not outside, the cranial window. Conclusions : NMDA elicits dose‐dependent increases in CoBF that are composed of CSD‐dependent and ‐independent components in rats.