MRI in conjunction with a GnRH stimulation test may be useful in predicting future impairment of pituitary function; however, further studies are needed to assess the effect of chelation therapy on the iron overload in the gland.

High concentrations of inspired oxygen have been reported to have significant hemodynamic effects that may be related to increased free radical production. If oxygen therapy increases free radical production, it may also modify hemodynamic responses to a nitric oxide donor. Twenty-nine healthy male volunteers were studied using randomized, double-blind, placebo-controlled, crossover designs to determine whether oxygen therapy is associated with hemodynamic and forearm vascular effects. We measured hemodynamic parameters and forearm vascular responses before and 1 h after exposure to 100% oxygen versus medical air. Plasma 8-iso-PGF2alpha and plasma vitamin C were measured to assess the biochemical effects of oxygen administration. Hemodynamic measurements were also made following the acute administration of sublingual nitroglycerin. Oxygen therapy caused no significant change in blood pressure, plasma 8-iso-PGF2alpha, or vitamin C. Oxygen did cause a significant reduction in heart rate and forearm blood flow, and an increase in peripheral vascular resistance. Oxygen caused no change in the hemodynamic response to nitroglycerin. Therefore, in healthy young adults, therapy with 100% oxygen does not affect blood pressure, despite causing an increase in vascular resistance, is not associated with evidence of increased free radical injury, and does not affect the hemodynamic responses to nitroglycerin.

Tolerance to nitroglycerin (NTG) may be due to increased superoxide anion production. Hemodynamic parameters and biochemical markers of free radical production were measured in 20 healthy male subjects at baseline, 3 h after acute transdermal NTG (0.6 mg/h), and after 5 days of continuous therapy. Transdermal NTG therapy was continued, and 2 days later all subjects received 2 g of oral vitamin C, or placebo, in a double-blind, randomized, crossover fashion. In another study of eight male subjects, forearm plethysmography was used to assess the venous responses to sublingual NTG at baseline, after 5 days of sustained transdermal NTG therapy (0.6 mg/h), and after 2 g of oral vitamin C or placebo. Systolic blood pressure decreased in response to acute transdermal NTG therapy but returned to normal after sustained NTG therapy, indicating the development of tolerance. The venous volume responses to sublingual NTG were significantly diminished after sustained therapy with transdermal NTG. Plasma lipid peroxidation products, 8-iso-PGF2 alpha, and vitamin C were unchanged by acute and sustained therapy with transdermal NTG. Vitamin C failed to restore either the hemodynamic or venous effects of NTG. These results do not support the hypothesis that nitrate therapy and tolerance is associated with increased free radical production.

In our study we confirmed the correlation of CA19-9 levels with cholestasis and cytolysis parameters. Moreover, we found no association between CA19-9 levels and impaired liver function as assessed by means of the Child-Pugh's score and the monoethylglycinexylidide test, which is cholestasis-independent and explores liver metabolic and clearance activities. The cholestatic picture that characterizes liver cirrhosis might enhance the expression and passage of the marker from the bile to the blood. The addition of CA19-9 assessment is not useful for the diagnosis of hepatocellular carcinoma in patients with non-diagnostic levels of alpha-fetoprotein. Caution should therefore be used when evaluating CA19-9 in cirrhotic patients with cholestasis, since false positive results may occur.

High concentrations of inspired oxygen have been reported to have significant hemodynamic effects that may be related to increased free radical production. If oxygen therapy increases free radical production, it may also modify hemodynamic responses to a nitric oxide donor. Twenty-nine healthy male volunteers were studied using randomized, double-blind, placebo-controlled, crossover designs to determine whether oxygen therapy is associated with hemodynamic and forearm vascular effects. We measured hemodynamic parameters and forearm vascular responses before and 1 h after exposure to 100% oxygen versus medical air. Plasma 8-iso-PGF2alpha and plasma vitamin C were measured to assess the biochemical effects of oxygen administration. Hemodynamic measurements were also made following the acute administration of sublingual nitroglycerin. Oxygen therapy caused no significant change in blood pressure, plasma 8-iso-PGF2alpha, or vitamin C. Oxygen did cause a significant reduction in heart rate and forearm blood flow, and an increase in peripheral vascular resistance. Oxygen caused no change in the hemodynamic response to nitroglycerin. Therefore, in healthy young adults, therapy with 100% oxygen does not affect blood pressure, despite causing an increase in vascular resistance, is not associated with evidence of increased free radical injury, and does not affect the hemodynamic responses to nitroglycerin.