[Comparative studies on bone growth in experimental animals. 1. Bone growth and ossification in mice (author's transl)]

Comparative studies are needed on the bilogical stage of the bone growth in experimental animals and human to extrapolate the data from animals to for estimating the risk of bone seeking redionuclides in man. The growth of bone length and the appearance and fusion of the secondary ossification centers of seven long bones were compared between both species. The stage of ossification was determined radiographically. The results showed that the ossifying process of the secondary ossification centers could be divided into the following three categories in mice; (1) acute ossification type, (2) remaining metastable stage type which is specific in mice and generally at the proximal end of bone, and (3) delayed ossification type. Compared with the average life span, differences in ossification between both species were that the appearance of secondary ossification centers was observed within concentrated period in mice and not in man, and that the fusion of these was observed with long duration in mice and not in man. From 17 weeks of age, the metastable status of the bone appeared in mice without complete fusion even at 27 weeks of age, for the experiment with bone seeking radionuclides, mice of age 17 weeks or more should be used consequently.

The dissociation of human deoxyhemoglobin and mixed state hemoglobin into monomer

The experimental hybridizations between fully deoxygenated human and canine hemoglobins and between half-ligated human hemoglobin and canine cyanomethemoglobin show that new two hybrids in addition to the parent hemoglobins were clearly formed in the mixtures at the high concentration of KI. Thus, human deoxyhemoglobin under the present conditions is in an equilibrium with three species, tetramer in equilibrium dimer in equilibrium monomer. This means that the deoxyhemoglobin is in R-T equilibrium, and shifts considerably toward the R state under the present conditions. On the other hand, the half-ligated hemoglobin in 1.5 M KI becomes much more dissociable than the deoxy T state and appears to be completely transformed into the R state. Nevertheless, the co-operativity, n, is still high (n = 2.0).

Epidermoid tumor in the lateral ventricle. Significance of echo-encephalography

The authors report on a case of epidermoid tumor in the lateral cerebral ventricle. Epidermoid tumors are relatively uncommon intracranial lesions and were first described by Esmarch. Till now about 300 cases have been reported. In Japan this tumor was first described by Yamamura, and since then many cases have been reported. But the one situated in the lateral ventricle has not been reported yet in this country. The significance of echo-encephalography is discussed because this procedure was very useful in determining the location and the nature of the tumor of this case.