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Biomedical subjects

I Smith

Publications and source records attributed to I Smith.

At least 451 records · Page 25Linked to original sources

Separate transport systems for sugars and amino acids in developing rat kidney cortex.

The ability of renal cortical slices of newborn and young rats to accumulate a nonmetabolizable sugar, alpha-methylglucoside, is slight and does not reach adult capacity until 25 days of age. However, a rudimentary sugar transport system is present, as indicated by a further decrease in accumulation in the presence of phlorizin or absence of sodium ion.Amino acid uptake in immature kidney tissue is not deficient; on the contrary, the tissue took up and concentrated more glycine and lysine than adult tissue. Decreased amino acid efflux from the immature cells appears to be the explanation. Concentration dependence of amino acid uptake was the same in 5-day-old and adult tissue. These differences between the transport characteristics of a model sugar and representative amino acids during development indicate separate transport systems for the two types of substrate.

Amino Acids↗

Genetic mapping of antibiotic resistance in markers Bacillus subtilis.

Several antibiotic resistance markers in Bacillus subtilis have been mapped by three-factor transduction crosses using bacteriophage PBS1. These markers, which are thought to be located in genes coding for ribosomal proteins, are within a segment comprising about 5 per cent of the B. subtilis genetic map, close to the major group of rRNA cistrons. The order of genetic makers in this region was found to be cysA14 mic-1 dagger str-1 (ery-1, ole-2) spc-2 bry-2 lin-2. The positions of neo-2, nea-1, and kan-2 are uncertain, although they are located in this region to the right of cysA14.

Anti-Bacterial Agents↗