Role of prostaglandin H synthase in activation of acrylonitrile to cyanide

The present study aimed at investigating the in-vitro oxidation of acrylonitrile [ACN] to cyanide [CN] by prostaglandin H synthase [PHS]. Detection of CN is considered a marker for free radical intermediates involved in ACN-induced toxicity. First, most favorable circumstances for ACN oxidation were characterized: pH [4.5], temperature [37 degree C] and time of incubation [60 min.]. In addition, the concentrations of ACN, PHS and H2O2 in incubation mixtures were assessed for further reaction characterization. The reaction maximum velocity [Vmax] was calculated to be 582.75 pmol CN/mL/min and the Michaelis-Menten constant [Km] was 149.25 µmol ACN. Adding PHS inhibitors; resveratrol, quercetin, indomethacin or troloc-C to the reaction mixtures significantly reduced the rate of ACN oxidation. In conclusion, the present study demonstrates the ability of PHS to oxidize ACN to CN and provides a clue for the explanation of ACN target toxicity

Serum Amyloid - a protein and serum Rheumatoid factor as serological surrogate markers for smoking risk factor in Saudi population

Tobacco smoking represents major national and international health hazard that interferes with wide range of physiological functions and biomarkers. In the current study we have investigated the influence of tobacco smoking on some biological markers such as serum amyloid protein-A, rheumatoid factor, serum glucose level and lipid profile in Saudi population. The fore mentioned parameters were investigated in a total of 275 cases in 3 different age categories [less than 20 years old, 20-40 years old and older than 40 years old]. Long term survey was adopted in all cases; yet, lightly smoking and heavily smoking groups were compared to never smoking healthy population. Results obtained showed significant increase in serum amyloid protein-A and rheumatoid factor in correlation to the degree of smoking nonetheless in the age category older than 40 years old. Serum glucose, triglyceride, and total cholesterol was not affected by smoking in all studied age categories; however serum LDL-cholesterol was elevated and serum HDLcholesterol was depressed in correlation to the degree of smoking in all age categories. In conclusion, tobacco smoking represents major cardiovascular risk factor in Saudi population in all age categories and serum amyloid protein-A and rheumatoid factor might be used as a serological surrogate marker for such risk