Rearrangement of the T cell receptor gamma-chain gene in childhood acute lymphoblastic leukemia

We analyzed rearrangements of the T cell receptor gamma-chain (T gamma) gene as well as rearrangements of the T cell receptor beta-chain (T beta) gene and immunoglobulin heavy-chain (IgH) gene in 68 children with acute lymphoblastic leukemia (ALL). All 15 patients with T cell ALL showed rearrangements of both T beta and T gamma genes. Twenty-four of 53 non-T, non-B ALL patients (45%) showed T gamma gene rearrangements and only 14 of these also showed T beta gene rearrangements. Only a single patient rearranged the T beta gene in the absence of T gamma gene rearrangement. The rearrangement patterns of the T gamma gene in non-T, non-B ALL were quite different from those observed in T cell ALL, as 20 of 23 patients retained at least one germline band of the T gamma gene. In contrast, all T cell ALL patients showed no retention of germline bands. These data indicate that rearrangement of the T gamma gene is not specific for T cell ALL. Further, the results also suggest that T gamma gene rearrangement precedes T beta gene rearrangement. The combined analysis of rearrangement patterns of IgH, T beta, and T gamma genes provides new criteria for defining the cellular origin of leukemic cells and for further delineation of leukemia cell heterogeneity.     

The Role of Serotonin (5-HT) in Behavioral Control: Findings from Animal Research and Clinical Implications

The neurotransmitters serotonin and dopamine both have a critical role in the underlying neurobiology of different behaviors. With focus on the interplay between dopamine and serotonin, it has been proposed that dopamine biases behavior towards habitual responding, and with serotonin offsetting this phenomenon and directing the balance toward more flexible, goal-directed responding. The present focus paper stands in close relationship to the publication by Worbe et al. (2015), which deals with the effects of acute tryptophan depletion, a neurodietary physiological method to decrease central nervous serotonin synthesis in humans for a short period of time, on the balance between hypothetical goal-directed and habitual systems. In that research, acute tryptophan depletion challenge administration and a following short-term reduction in central nervous serotonin synthesis were associated with a shift of behavioral performance towards habitual responding, providing further evidence that central nervous serotonin function modulates the balance between goal-directed and stimulus-response habitual systems of behavioral control. In the present focus paper, we discuss the findings by Worbe and colleagues in light of animal experiments as well as clinical implications and discuss potential future avenues for related research.     

Melatonin suppresses NO-induced apoptosis via induction of Bcl-2 expression in PGT-beta immortalized pineal cells

In the present study, we investigated whether melatonin would prevent nitric oxide (NO)-induced apoptotic death of PGT-beta immortalized pineal cells. To examine the protective effect of melatonin, cytotoxicity assay, DNA fragmentation analysis, caspase-3 activity assay, and Western blotting for caspase-3 and poly(ADP-ribose) polymerase (PARP) were performed. Treatment of cells with S-nitroso-N-acetylpenicillamine (SNAP), an NO donor, was shown to induce apoptotic cell death in a dose-dependent manner, and pretreatment with melatonin (0.1 mm) attenuated the occurrence of NO-induced apoptotic cell death. DNA fragmentation in response to NO was also arrested by melatonin. Caspase-3 activity induced by NO was decreased with melatonin treatment. Furthermore, the active fragments of caspase-3 and PARP were almost completely absent following exposure to melatonin. To elucidate the protective mechanisms of action of melatonin, Western blot analyses for Bcl-2 expression and cytochrome c release were carried out. Pretreatment with melatonin (0.1 mm) induced the expression of Bcl-2 and suppressed the release of cytochrome c into the cytosol, thereby arresting NO-induced apoptotic cell death. These results suggest that the antiapoptotic effect of melatonin is associated with induction of Bcl-2 expression in PGT-beta cells, which in turn blocks caspase-3 activation and inhibits cytochrome c release into the cytosol.     

Relationship between insulin resistance and serum alanine aminotransferase as a surrogate of NAFLD (nonalcoholic fatty liver disease) in obese Korean children

There has been increasing number of obese children who accompany obesity-related comorbidities. It has been known that nonalcoholic fatty liver disease (NAFLD) as one of obesity-related comorbidities is related with insulin resistance. So, we investigated the relation between insulin resistance and NAFLD, using serum alanine aminotransferase (ALT) as a surrogate of NAFLD among obese children in Korea. The study subjects were 909 obese children aged 9–12 years (boys 613, girls 296). Body mass index (BMI), waist circumference (WC), blood pressure, fasting blood glucose, fasting insulin, lipid profile were measured. ALT, liver enzyme was used as a surrogate of NAFLD and homeostasis model assessment of insulin resistance (HOMA-IR) was used as the index of insulin resistance. The prevalence of elevated serum ALT (≥40 mg/dl) was 33.4% in boys, and 19.6% in girls respectively. In boys, ALT was correlated with BMI, waist circumference, total cholesterol, triglyceride, HDL-cholesterol, systolic and diastolic blood pressure, HOMA-IR, fasting serum insulin. Odds ratio for HOMA-IR against the elevated ALT (≥40 mg/dl) was 1.061 (95% confidence interval, 1.020–1.103, P = 0.003). In girls, ALT was correlated with BMI, waist circumference, total cholesterol, triglyceride, glucose, systolic and diastolic blood pressure, HOMA-IR, fasting serum insulin. Odds ratio for HOMA-IR against the elevated ALT (≥40 mg/dl) was 1.042 (95% confidence interval, 0.998–1.088, P = 0.063). Among obese Korean children, insulin resistance and ALT, lipid profile, BMI, WC, blood pressure showed significant correlation. Especially, in boys, higher ALT is founded to be independently associated with insulin resistance.     

Insulin receptors on leukemia and lymphoma cells

Tumor cells obtained from leukemia and lymphoma patients were investigated for specific insulin receptors. Using radioactive 125I- labeled insulin, specific insulin binding sites were demonstrated on most acute lymphocytic leukemia (ALL) and acute myelocytic leukemia (AML) cells, including acute promyelocytic leukemia (APL), chronic myelocytic leukemia (CML), and acute monocytic leukemia (AMoL) cells. Insulin receptors were not found on chronic lymphocytic leukemia (CLL) and malignant lymphoma (ML) cells. Specific insulin binding sites were also found on monocytes and thymocytes after treatment with phytohemagglutinin (PHA-P), but not on inactivated tonsil cells, peripheral blood lymphocytes, or thymocytes. There was no inverse correlation between the content of insulin receptors and the basal level of circulating insulin. These data suggest that the insulin receptor may be a new marker of acute leukemia and chronic myelocytic leukemia.     

The Redox Modulating Sonlicromanol Active Metabolite KH176m and the Antioxidant MPG Protect Against Short-Duration Cardiac Ischemia-Reperfusion Injury

Cardiovascular Drugs and Therapy - Sonlicromanol is a phase IIB clinical stage compound developed for treatment of mitochondrial diseases. Its active component, KH176m, functions as an antioxidant,...     

Oral prostaglandin (PGE2) therapy for chronic viral hepatitis B and C

The cytoprotective effects of prostaglandins have been utilized in the prevention of hepatitis B virus reactivation after liver transplantation. This pilot study evaluated the effects of oral prostaglandin E₂ (PGE₂) in chronic viral hepatitis B and C. Twenty patients with chronic hepatitis B and 20 patients with chronic hepatitis C received 4mgday^–1 PGE₂ for 6 months. The lymphocyte antiviral enzyme 2',5'-oligoadenylate synthetase (2',5'-OAS) and peripheral blood monocyte procoagulant activity (PCA) were measured before, during and after the treatment. Three of 20 hepatitis B and five of 20 hepatitis C patients withdrew from the study. Eight of 17 hepatitis B patients responded: in seven of these eight patients, serum alanine aminotransferase (ALT) levels normalized; loss of viral replication was sustained in all eight patients; and seroconversion from hepatitis Be antigen (HBeAg) to hepatitis Be antibody (HBeAb) positivity occurred in seven patients over the 48-week duration of this study. In 14 of the 15 hepatitis C patients, hepatitis C virus (HCV) RNA remained detectable and the serum ALT levels remained elevated. 2',5'-OAS levels and PCA values did not correlate with other markers of response to PGE₂ therapy in either chronic hepatitis B or C. In summary, PGE₂ was associated with sustained loss of viral replication in 47% of chronic hepatitis B patients; no beneficial effects were apparent in chronic hepatitis C.