The Modulation of Euglycemic Endocrine and Exocrine Pancreatic Secretions in Iron Deficiency.

OBJECTIVES: The contribution of pancreatic secretions in iron metabolism has been elucidated, but the clinical outcomes of iron deficiency on pancreatic function are debatable. This study aimed to investigate the modulation of euglycemic endocrine and exocrine pancreatic excretions in response to variations in iron availability. SUBJECTS AND METHODS: Serum levels of insulin, glucagon, insulin-to-glucagon ratio (IGR), and amylase were determined in 170 adult subjects with variable levels of serum iron. RESULTS: Control (n = 46) and iron-deficient (n = 124) subjects had significant differences (p < 0.001) in their average levels of insulin (68.7 ± 0.5 vs. 100.0 ± 2.0 pmol/dL), glucagon (17.9 ± 0.6 vs. 10.8 ± 0.8 pmol/dL), IGR (4.0 ± 0.1 vs. 19.5 ± 2.1), and amylase (29.7 ± 0.9 vs. 17.5 ± 0.2). The upregulation of serum insulin levels increases proportionally and gradually to the extent of iron deficiency as compared to an abrupt downregulation of serum levels of glucagon and amylase. A significant association was observed between serum iron and IGR (r = -0.645, p < 0.001) and amylase levels (r = 0.653, p < 0.001). The receiver operating characteristic curve analysis defines an excellent predictivity of the reduced serum iron level to discriminate subjects with upregulated IGR and amylase levels with area under curves of 0.938 and 0.905, respectively. CONCLUSION: Iron deficiency is associated with an adaptive modulation of euglycemic endocrine and exocrine secretions that is consistent with a status of insulin resistance.

Evidence on the Heroin-Mediated Impairment of the Oxidative Status of Erythrocytes.

Away from hemorheological properties, the effect of heroin addiction on erythrocytes is poorly investigated. This study aimed to investigate the oxidative impacts of heroin administration on erythrocytes. Study subjects included chronic intravenous heroin addicts and control subjects. Hematological analysis and redox parameters were measured, including serum concentration of methemoglobin ([MethHb]), serum glutathione peroxidase-1 ([GPX-1]), serum glutathione peroxidase (GPX) activity, erythrocytic protein carbonyl content, and oxidized to reduced glutathione (GSSG/GSH) ratio. Hematological analysis revealed that addicts had a significantly higher red cell distribution width, consistent with the mild anisocytosis and poikilocytosis of erythrocytes. As compared to control subjects, significantly higher levels of serum [Met-Hb], [GPX-1], and GPX activity (p < 0.001) were reported among addicted subjects. A significant association between [MetHb] and GPX activity was observed with r = 0.764 (p < 0.001). Furthermore, significantly higher erythrocytic protein carbonyl contents and GSSG/GSH ratio were evident among heroin addicts (p < 0.005) that were significantly associated with r = 0.429 (p=0.01). Results demonstrate preliminary evidence that heroin addiction is implicated in impaired redox status of erythrocytes. Considering the pharmacokinetics of heroin, erythrocytic antioxidant mechanisms, and turnover rate, further investigation is required to evaluate the extent and clinical outcomes, especially upon over-dose administration.

A Proposed Kinetic Model for the Diagnostic and Prognostic Value of WT1 and p53 in Acute Myeloid Leukemia.

BACKGROUND: Wilms tumor (WT1) and p53 proteins were identified in the pathogenesis of several malignancies, including hematological malignancies. As a result of their interaction and diverse context-specific functions, this study aimed to emphasize the diagnostic and prognostic impacts of WT1 and p53 expression in acute myeloid leukemia (AML). METHODS: Twelve bone marrow (BM) biopsies were obtained from AML patients who were diagnosed in accordance with the French-American-British diagnostic criteria. For comparative purposes, nine normal BM biopsies were included. The expression rate of WT1 and p53 were determined by an immunohistochemistry assay. RESULTS: A significantly higher (p < 0.005) and strongly correlated ( = 0.855, p = 0.001) expression rates of WT1 and p53 were observed in the BM of AML patients in comparison to control BM. Furthermore, relapsed AML patients had significantly higher expression of WT1, but not p53, when compared to newly diagnosed patients. In regard of patient's responsiveness to chemotherapy, no significant difference was reported between good and poor responders. However, the relative ratio of p53 to WT1 expression was evidently correlated to the responsiveness groups (p < 0.05), where the ratio was observed to be significantly higher among poor responders. Poor responders were characterized by a statistically significant and dominant p53 expression (p53/WT1 > 1.0) while both good responding patients and control subjects had a dominant WT1 expression (p53/WT1 < 1.0). CONCLUSIONS: The enhanced expression levels of WT1 and p53 proteins in the BM of AML patients is supportive of their intermediate role in the pathogenesis of the disease. WT1 expression rate may encompass a negative prognostic value of the disease. Furthermore, the ratio of p53/WT expression may serve as a hallmark of the patient's responsiveness to chemotherapy, where a dominant WT1 expression may reveal good responsiveness to chemotherapy. Herein, we are proposing a kinetic model where the p53/WT1 ratio might be useful as a laboratory approach to evaluate the prognostic value of AML including the patient's responsiveness to chemotherapeutic regimen.

Tempol protects blood proteins and lipids against peroxynitrite-mediated oxidative damage.

Oxidative stress is characterized by excessive production of various free radicals and reactive species among which, peroxynitrite is most frequently produced in several pathological conditions. Peroxynitrite is the product of the superoxide anion reaction with nitric oxide, which is reported to take place in the intravascular compartment. Several studies have reported that peroxynitrite targets red blood cells, platelets and plasma proteins, and induces various forms of oxidative damage. This in vitro study was designed to further characterize the types of oxidative damage induced in platelets and plasma proteins by peroxynitrite. This study also determined the ability of tempol to protect blood plasma and platelets against peroxynitrite-induced oxidative damage. The ability of various concentrations of tempol (25, 50, 75, and 100 µM) to antagonize peroxynitrite-induced oxidation was evaluated by measuring the levels of protein carbonyl groups and thiobarbituric-acid-reactive substances in experimental groups. Exposure of platelets and plasma to 100 µM peroxynitrite resulted in an increased levels of carbonyl groups and lipid peroxidation (P < 0.05). Tempol significantly inhibited carbonyl group formation in plasma and platelet proteins (P < 0.05). In addition, tempol significantly reduced the levels of lipid peroxidation in both plasma and platelet samples (P < 0.05). Thus, tempol has antioxidative properties against peroxynitrite-induced oxidative damage in blood plasma and platelets.