Increased oxygen affinity for hemoglobin Sawara: alphaA4(6) aspartic acid replaced by alanine

The oxygen binding property of Hb Sawara (alphaA4 Asp replaced by Ala) was studied at different pH values with and without addition of 2,3-diphosphoglycerate. The oxygen affinity of Hb Sawara was shown to be increased, the difference of the log P50 value between normal and abnormal hemoglobins being 0.37 at pH 7.0. Both the magnitude of the alkaline Bohr effect and the effect of 2,3-diphosphoglycerate upon oxygen affinity of Hb Sawara were comparable to those of Hb A. The amino acid substitution of alanine for alphaA4 aspartic acid might result in the loss of a stabilizing force for ionic interaction between the alpha-amino group of NA (1)alpha1 valine and the alpha-carboxyl of HC3(141)alpha2 arginine in the deoxy-form.

Benign osteoblastoma as a cause of osteomalacia. A report of two cases

Two patients, a Japanese man and woman both aged eighteen, developed symptoms and signs of osteomalacia over a period of five years. Each of them had a benign osteoblastoma, one in the right fourth metacarpal and the other in the uppermost third of the right humerus. Resection of the tumours without any treatment by vitamin D resulted in rapid cure of the osteomalacia. Attempts to prove a phosphaturic humoral substance or vitamin D antagonist in the osteoblastoma of the humerus were unsuccessful, probably due to prompt excretion from the tumour cells.

Conformational changes and reassociation properties of small subunits of Escherichia coli ribosomes

Studies on the reassociation of ribosomal subunits from Escherichia coli were carried out using an ultracentrifuge equipped with a UV absorption scanner, and the conformational changes of ribosomal subunits were followed by circular dichroism measurements. Reassociation between the fractionated 30S and 50 S subunits was promoted by the addition of uncharged tRNA at 4 degrees. Furthermore, a sharp increase in the amount of reassociated products was observed on treatment of the sample solution at temperatures above 25 degrees. Treatment at higher temperature only affected 30 S ribosomal slbunits. From CD measurements of Mg2+ concentration dependence for both ribosomal subunits, a significant decrease in molar ellipticity [theta] at the 264 nm positive peak and a slight change of [theta] at the 222 nm band were observed for both subunits in dissociation buffer. Samples of 30 S subunits pretreated at 37 degrees for 40 min showed a small CD change at the 222 nm band. The same samples showed a slight increase in S value and enhanced ability to form 70 S particles with 50 S subunits. On the other hand, we detected no significant changes in CD spectra, S value or the ability to form 70 S particles with 50 S ribosomal samples subjected to same heat treatments.

Lower fiducial limit of urinary metabolite level as an index of excessive exposure to industrial chemicals

Imamura, T., and Ikeda, M. (1973).British Journal of Industrial Medicine,30, 289-292. Lower fiducial limit of urinary metabolite level as an index of excessive exposure to industrial chemicals. Utilization of the lower fiducial limit (P = 0·10), rather than the mean, as an index of excessive exposure to industrial chemicals is discussed. Cases of exposure to trichloroethylene, phenol, and toluene are used to illustrate this approach.