The accessibility of the cysteine residues of actin from rabbit muscles to the thiol-targeted reagent 7-dimethylamino-4-methyl-(N-maleimidyl)coumarin (DACM) was investigated. Under conditions where the actin is in the unpolymerized form (G-actin), the most reactive thiol group was Cys-257, suggesting that it was located on the surface of the actin molecule. The selective modification of Cys-374...

A rapid, sensitive and reproducible HPLC method was developed and validatedfor the analysis of amifostine (AMF) and/or its metabolite, WR-1065 inhuman plasma. The method involves the alkylation of free sulfydryl group with iodoacetic acid followed by derivatization of the drug and its metabolite witho-phthaldialdehyde (OPA) andUVdetection at 340 nm. The derivatized AMF and WR-1065 were eluted i...

The implications of disinfection by-products (DBPs) present in drinking water are of public health concern because of their potential mutagenic, carcinogenic and other toxic effects on humans. In this study, we selected 13 main DBPs found in drinking water to quantitatively analyse their cytotoxicity and genotoxicity using a microplate-based cytotoxicity assay and a developed SOS/umu assay in S...

In a previous publication Bondi and Dietz (1947) reported that various factors could influence the susceptibility of penicillinase-producing bacteria to penicillin. The authors concluded that individual cells of certain organisms that produce this enzyme may be just as susceptible to penicillin as those of organisms that do not produce penicillinase. In a continuation of this study, the effect ...

Group A streptococci were tested for proteinase production and for the possible relationship of this production to the generation of bacteriocinlike inhibitor activity. Of 126 strains tested, 83% were positive for proteinase, and a similar distribution was found among strains isolated in association with rheumatic fever (89%) and nephritis (94%) and from uncomplicated acute infections (78%). Al...

a rapid, sensitive and reproducible hplc method was developed and validatedfor the analysis of amifostine (amf) and/or its metabolite, wr-1065 inhuman plasma. the method involves the alkylation of free sulfydryl group with iodoacetic acid followed by derivatization of the drug and its metabolite witho-phthaldialdehyde (opa) anduvdetection at 340 nm. the derivatized amf and wr-1065 were eluted i...

1. Group A streptococci sometimes produce in broth culture an extracellular proteolytic enzyme. 2. Under suitable cultural conditions the enzyme has been demonstrated in representative cultures of most of the Griffith types. Its production by a given strain may be suppressed by serial passage through mice and the variant so produced has been found to maintain this change in character on subcult...