ATP markedly stimulated sulphate uptake by rat liver lysosomes that had been treated with N-ethylmaleimide to block the effects of the lysosomal proton-translocating ATPase (H+-ATPase). Maximal stimulation required millimolar concentrations of ATP and neutral buffer pH. ATP-stimulated transport exhibited saturation kinetics with a Km of 175 microM, identical with the Km for lysosomal sulphate u...

The amino acid carriers in sugarcane suspension cells were characterized for amino acid specificity and the stoichiometry of proton and potassium flux during amino acid transport.Amino acid transport by sugarcane cells is dependent upon three distinct transport systems. One system is specific for neutral amino acids and transports all neutral amino acids including glutamine, asparagine, and his...

Here we present new evidence that riboflavin is present as one of four flavins in Na+-NQR. In particular, we present conclusive evidence that the source of the neutral radical is not one of the FMNs and that riboflavin is the center that gives rise to the neutral flavosemiquinone. The riboflavin is a bona fide redox cofactor and is likely to be the last redox carrier of the enzyme, from which e...

The transport of neutral amino acids into mitochondria isolated from the hypocotyl of mung bean (Roxb.) was studied by the swelling technique. Isolated mitochondria swelled when added to an isosmotic solution of proline, serine, methionine, threonine, alanine, and glycine. The swelling was stereospecific in that it was faster in the l-amino acid than in the corresponding d-amino acid. Preincuba...

The unique potentiometric response of mercury sensors was investigated in aqueous Cl(-)-rich media, which are often encountered in natural, especially biological samples. The conventional neutral-carrier-based Hg(II)-ISEs are not practically useful because the Cl(-) concentrations in natural aqueous samples are normally too high for mercury to be present in the form of Hg(2+). Negative potentio...

background: salmonella enterica serovar typhi (s. typhi) the cause of the acute febrile disease typhoid fever is the major public health problem in developing countries. asymptomatic carriers are the main sources of typhoid. the aim of this study was to investigate methods for isolation and identification of s. typhi in asymptomatic carriers. materials and methods: two hundred stool samples wer...

hepatitis delta virus (hdv) infection results in more severe and even fulminant form of hepatitis b in co-infected cases. this study was designed to estimate the prevalence of anti-hdv positivity and the associated risk factors in patients with chronic hepatitis b virus infection in zahedan (iran). in this cross-sectional study a total of 440 consecutive patients with chronic hepatitis b virus ...

introduction : staphylococcus aureus colonization has been recognized as one of the most important risk factors for subsequent infections with this microorganism. in this study, we intended to identify all patients who were mrsa-positive upon admission and compare the prevalence of mrsa colonization on different days of study admitted in imam reza hospital in mashhad, iran. methods : this cross...

A synthesized bis(dibenzoylmethanato)Co(II) complex (Co(DBM)(2)), has been used as a ionophore for the preparation of a new perchlorate ion-selective electrode. The electrode exhibits a Nernstian response over the perchlorate concentration range of 8.0x10(-7)-1.0x10(-1)M with a slope of 60.3+/-0.5 mV per decade of concentration. The limit of detection as determined from the intersection of the ...

A polystyrene-based membrane of 2,10-dimethyl-4,12-diphenyl-1,5,9,13tetraazacyclohexadeca-1,4,9,12-tetraene macrocyclic ionophore was prepared and investigated as Cr(III)-selective electrode. The best performance was observed with the membrane having the polystyrene-ligand-dibutylphthalate-sodiumtetraphenyl borate composition 1:4:1:1 with a Nernstian slope of 19.0 mV per decade of concentration...