The previously reported inability of methionine to stimulate cephalosporin C production in a cysteine auxotroph is due to cysteine interference with methionine uptake. In such a cse, "illicit transport" of alanylmethionine can be used to demonstrate the efficacy of methionine in such mutants blocked in the path from methionine to cysteine. This result supports the hypothesis that the stimulator...

the prevalence of allergic diseases is high in the general population, and the high prevalence of these diseases not only leads to considerable mortality and morbidity, but also has economic importance. in this study 400 patients were evaluated in tehran and karaj cities during 1995-1998. skin prick test with stan¬dard extracts was done in patients in comparison with controls. selection of ex¬t...

BACKGROUND Infertility is a public health problem associated with devastating psychosocial consequences. In countries where infertility care is difficult to access, women turn to herbal medicines to achieve parenthood. The aim of this study was to determine the prevalence and factors associated with herbal medicine use by women attending the infertility clinic. METHODS This was a cross-sectio...

this experiment was conducted in international researchery institute of sturgeon fishes shahid  dadman. the basal diet contained fish meal as protein source (cp=40%). five diets were supplemented with 5 graded levels of methionine, (0, 0.5,1 ,1.5, 2% met per kg diet) . each diet was randomly assigned to triplicate groups of 195 juvenile huso huso (initial weight 31.9± 2.8) in fiftin 500-l circu...

BACKGROUND Herbal products available to consumers in the marketplace may be contaminated or substituted with alternative plant species and fillers that are not listed on the labels. According to the World Health Organization, the adulteration of herbal products is a threat to consumer safety. Our research aimed to investigate herbal product integrity and authenticity with the goal of protecting...

In immature rib segments prepared from morning-glory (Ipomoea tricolor) flower buds, the major soluble metabolite formed from tracer amounts of l-methionine-U-(14)C was S-methylmethionine (SMM). In segments of senescing ribs, (14)C was progressively lost from SMM and appeared in free methionine. Immature segments contained about 4 nmoles of free methionine and about 16 nmoles of SMM per 30 segm...

Extensive research on the formation of methionine has implicated vitamin B12 as a cofactor in the final reaction of the biosynthetic sequence. Since plants and fungi do not produce or require B12, an alternate reaction must also exist. It is thus not surprising that Escherichia coli has been found to possess two mechanisms for the methylation of homocysteine to methionine (9). These reactions a...