If the level of MetHb
is less than 20%, recovery can be achieved by stopping the causative drug, but newborns and infants may still require treatment.
(11) detected a decrease from 100% to 89% in a breast cancer case 5 minutes after administration of 4 mL (100 mg) patent blue, which was reflected in arterial blood gas measurements of pH: 7.45, Pa[O.sub.2]: 544.7 mmHg, PaC[O.sub.2]: 35.7 mmHg, Sa[O.sub.2]: 99.9%, and MetHb
W ciezkich przypadkach - kiedy stezenie MetHb
przekracza 60% - nalezy rozwazyc zabieg wymiennego przetaczania krwi.
RBC lysate (2.5 x 108 cells/ml equivalent), 2 mg/ml metHb
, or 2 mg/ml myoglobin was coated onto an Immunlon-2, 96-well plate in a carbonate coating buffer (0.16 M [Na.sub.2]C[O.sub.3], 0.34 NaHC[O.sub.3], pH 9.6) overnight at 4[degrees]C.
This phenomenon can be explained by absorbance ratio of MetHb
. Pulse oximetry machines measure absorbance of hemoglobin at two wavelengths (660 and 940 nm).
Cell-free Hb molecules have intrinsic toxicity to tissues since harmful ROS is produced during autoxidation of oxyHb to metHb
Mean percentage of MetHb
levels of the infants was 28.8[+ or -]9.8 (14.7-44%).
Nitrate ion readily oxidises haemoglobin to MetHb
. Severe poisoning can result from the ingestion of nitrates by infants.
In the absence of microorganisms, the red blood cells will age slowly, eventually lysing and the haemoglobin present converting to met-haemoglobin (metHb
) over a few days.
Naturally, 0.53-3.0% of the total hemoglobin (Hb) circulates as methemoglobin (MetHb
The concentration of oxy-and met-Hb were determined spectrophotometrically in the haemolysate by measuring the absorbance at 577 and 630 nm as described by Winterbourn (10) (oxyHb [concentration of heme, [micro]M] = 66 [A.sub.577] - 80 [A.sub.630]; metHb
[concentration of heme, [micro]M] = 279 [A.sub.630] - 3 [A.sub.577]).
Ingested nitrate is reduced to nitrite, which binds to hemoglobin to form methemoglobin (MetHb