Experimental observations and mathematical considerations on the mechanism of transport of uric acid across human gastric mucosa

Summary Under standardized experimental conditions it is shown that the uric acid concentration in human gastric juice is pH-dependent. The gastric uric acid concentration falls as a hyperbolic function with increasing acidity of gastric juice. Normally a concentration ratio of uric acid between gastric juice and plasma in the range of 0.2–0.4 will be found. These results are compatible with the conception of uric acid transport by means of non-ionic diffusion. In theoreticalmathematical considerations rate limiting factors on non-ionic diffusion of a weak acid from plasma into gastric juice are described.     

Incidence of hairy cell leukemia, mycosis fungoides, and chronic lymphocytic leukemia in first known HTLV-II-endemic population

Unlike human T cell leukemia-lymphoma virus type I (HTLV-I), HTLV-II has not been convincingly linked to a malignancy. In the first 10 months of serologic screening for HTLV-I/II among blood donors in New Mexico in 1988-1989, HTLV-I/II infection was found in 27 donors. HTLV-I/II infection was present in 1.0%-1.6% of American Indian and 0.16%-0.27% of Hispanic donors compared with 0.009%-0.06% of non-Hispanic white donors. HTLV-II was identified by DNA amplification in 12 of 13 samples from Indian and Hispanic seropositive donors. Despite apparent endemic HTLV-II infection in these populations, New Mexico Tumor Registry data showed that the incidences of hairy cell leukemia, mycosis fungoides, and chronic lymphocytic leukemia were comparable among the three ethnic groups. A population with endemic HTLV-II infection has been identified, and there is no evidence of increased risk for these three malignancies in the endemic groups.     

Xeromammographic automatic exposure termination

A method of automatic exposure termination (AET) for xeromammography has been devised, significantly reducing the rate of repeat exposures due to poor choice of manual exposure factors. AET images are of good quality and are reliably produced. The concept of AET is based on the existence of an optimal transmitted exposure to the selenium plate, which is easily determined experimentally. In routine clinical xeromammography, a repeat rate of 20% was eliminated by the use of AET.     

A83586C, a new depsipeptide antibiotic

A culture identified as Streptomyces karnatakensis was found to produce a novel cyclic hexadepsipeptide antibiotic designated A83586C. The structure was elucidated by X-ray crystallography, and full 1H and 13C NMR assignments are reported. The absolute configuration was confirmed by the detection of D-threonine in the acid hydrolysate of A83586C. A83586C had potent Gram-positive activity in vitro but lacked in vivo efficacy in mice.