As a main aim we want to focus on the sources of oxidants as key factors in understanding the role oxidants play in the pathogenesis of brain vascular endothelial dysfunction. The question remains whether iron inversion and subsequent radical formation is a primary or secondary event in neurodegenerative disease. Recent research suggests that iron inversion is an initial cause of neuronal cell ...

The nonenzymatic reduction of methemoglobin by the reduced form of flavin mononucleotide was studied under various conditions by following the reaction with a stopped flow apparatus. The reaction was very fast, compared with the reduction of the flavin by NADPH-flavin reductase of human erythrocytes, and followed a second order rate law: the rate constant (K) for the reduction of methemoglobin ...

In this study we present evidence that in human erythrocytes NADH-cytochrome b5 reductase (methemoglobin reductase) is not only soluble but also tightly bound to the membrane. The membrane methemoglobin reductase-like activity is unmasked by Triton X-100 treatment, and represents about half of the total activity in the erythrocytes. Like the amphiphilic microsomal-bound cytochrome b5 reductase,...

In reviewing the article “Methemoglobinemia: Sudden Dyspnea and Oxygen Desaturation After Esophagoduodenoscopy,” in the August 2004 issue of RESPIRATORY CARE,1 I found the article suggested that, during the esophagoduodenoscopy procedure the patient’s blood oxygen saturation (measured via pulse oximetry) began to drop rapidly, and a saturation of 54% registered on the pulse oximeter while the p...

A method for the estimation of the concentration of the blue dye, T-1824, in plasma has been developed. The method is based on the fact that the dye can be reduced to a colorless compound by Na(2)S(2)O(4), in alkaline solution. The extinction coefficient is determined under specified conditions before and after reduction of the dye. Under the conditions employed hemoglobin does not interfere, e...

Specific ligation states of hemoglobin are, when crystallized, capable of taking on multiple quaternary structures. The relationship between these structures, captured in crystal lattices, and hemoglobin structure in solution remains uncertain. Wide-angle X-ray solution scattering (WAXS) is a sensitive probe of protein structure in solution that can distinguish among similar structures and has ...

Hemoglobin is oxidized to methemoglobin by products formed during the oxidation of a number of different substances. With some of these substances, both oxygen consumption and hemoglobin oxidation are accelerated by thermolabile constituents of pneumococci; with others of the easily oxidized substances, neither reaction seems to be influenced by the presence of the bacterial substances. The sam...

Case. We report a case of severe methemoglobinemia due to sodium nitrite poisoning. A 28-year-old man was brought to our emergency department because of transient loss of consciousness and cyanosis. He was immediately intubated and ventilated with 100% oxygen. A blood test revealed a methemoglobin level of 92.5%. Outcome. We treated the patient with gastric lavage, activated charcoal, and methy...

INTRODUCTION Local anesthesia with prilocaine has become a routine part of ambulatory circumcision procedures. Methemoglobinemia is a rare but potentially lethal complication of local anesthetics. CASE PRESENTATION We report the case of a 40-day-old Turkish boy who presented with cyanosis after receiving local anesthesia with prilocaine. His methemoglobin level revealed severe methemoglobinem...