A 12-day-old boy presented with duskiness 4 h after circumcision with local anesthesia: infiltration with lidocaine (6 mL 1 %) and topical EMLA cream (2.5 % lidocaine/2.5 % prilocaine). He had no respiratory distress, but a strikingly dark skin. A blood sample showed dark, chocolate brown blood with a raised methemoglobin of 49.8 % (normal <1.5 %) and a lactate of 10 mmol/L. A diagnosis of meth...

The occurrence in normal human blood either of methemoglobin, or of a form of “inactive Hb” which behaves like methemoglobin in containing trivalent Fe and in lacking the power to combine reversibly with 02 and CO until the Fe+++ is reduced to Fe++, has been both afhrmed and denied in the recent literature.1 Until a few years ago all the hemoglobin in normal human blood was assumed to be in the...

Aromatic amine sulfinamide adducts of hemoglobin are biomarkers of exposure and evidence for cytochrome P-450 N-hydroxylation. The possible peroxidatic formation of an N-acetylbenzidine (ABZ) sulfinamide adduct by methemoglobin was examined. Following addition of H2O2, 0.06 mM [3H]ABZ was metabolized by methemoglobin. With 0.3 mM glutathione, a new peak was observed, ABZ-SG, representing 17% of...

We have developed a low-cost, non-contact, multispectral photoacoustic microscope system to study the functional parameters of cellular choromophores. The system uses low power continuous wave lasers and a photoacoustic sensor made of a kHz microphone coupled to a resonant chamber. Methemoglobin has relatively high optical absorption at 500 nm and 630 nm. Moreover, it has an almost the same opt...

During investigations of the phenotypic diversity of hemoglobin (Hb) E β thalassemia, a patient was encountered with persistently high levels of methemoglobin associated with a left-shift in the oxygen dissociation curve, profound ascorbate deficiency, and clinical features of scurvy; these abnormalities were corrected by treatment with vitamin C. Studies of erythropoietin production before and...

The aim of this epidemiologic study was to point out a relationship between the exposure to products of coal combustion, and complications in pregnancy where one third of causes of stillbirth are still unknown. In the town of Labin (Croatia) a coal-powered thermoelectric power plant is the single major air polluter. We compared the records of miscarriages, premature births and stillbirths in tw...