background: hydrogen sulfide (h 2 s) exhibits both physiological and toxicological roles in the biological systems. acute exposure to high levels of h 2 s is life threatening while long-term exposure to ambient levels of h 2 s elicits human health effects. objective: to study the harmful effects of long-term exposure to low levels of h 2 s on human blood cells. methods: 110 adult workers from i...

A new instrument for spectrophotometric determination of oxygen saturation (S) and the fractions of carboxyhemoglobin (FHo) and methemoglobin (FHI), the Hemoximeter OSM3 (Radiometer), was tested by comparativemeasurements with a multiwavelength method. We found that it gave reliable results for freshly drawn samples from patients. When samples with artificially induced high proportions of HbCO ...

We describe a case of sulfhemoglobinemia associated with toxic paint ingestion. Blood gases, oxygen content, and fractional hemoglobin derivatives were assayed with Radiometer 520 and OSM3 instruments. Although the CO-oximeters indicated the presence of sulfhemoglobin (SulfHb), the results were not quantitative. An OSM3 service software program was activated to obtain the actual concentrations ...

The cystathionine beta synthase (CBS) gene is localized on chromosome 21 (21q22.3). This enzyme is one of three enzymes able to produce hydrogen sulfide. CBS is overexpressed in Down syndrome with levels 166% of normal values in fibroblasts [Chadefaux et al., 1985] and 1,200% in myeloblasts [Taub et al., 1999]. The CBS overexpression could induceanoverproduction ofhydrogen sulfide in Down syndr...

There are several pathologies whose study and diagnosis is impaired by a relatively small number of documented cases. A practical approach to overcome this obstacle and advance the research in this area consists in employing computer simulations to perform controlled in silico experiments. The results of these experiment, in turn, may be incorporated in the design of differential protocols for ...

A 46-kDa hemolytic protein referred to as cystalysin, from Treponema denticola ATCC 35404, was characterized and overexpressed in Escherichia coli LC-67. Cystalysin lysed erythrocytes, hemoxidized hemoglobin to sulfhemoglobin and methemoglobin, and removed the sulfhydryl and amino group from selected S-containing compounds (e.g., cysteine) producing H2S, NH3, and pyruvate. With L-cysteine as su...