Evaluation using dogs of a method for estimating mixed venous and arterial PCO2 from a single breath

Estimates of arterial and true mixed venous carbon dioxide tension (PCO2) were made from the continuous records of the changes in carbon dioxide and oxygen tensions in the expired gas during a single prolonged expiration, as described by Kim, Rahn, and Fahri (J. Appl. Physiol. 21: 1338, 1966). The results were compared with the results of direct analyses of systemic arterial and pulmonary arterial blood. There was no systemic error of the arterial estimates over a range of 32-48 Torr or of the venous estimates over a range of 33-59 Torr. The random errors of the arterial and venous estimates were +/- 1.5 and 1.2 Torr (2 SD) respectively. These results are better than those obtained by other noninvasive methods.     

Increased immunogenicity of TA3-Ha cells treated with the antitumor antibiotic macromomycin (B)

Suspension cultures of TA3-Ha mouse mammary tumor cells were treated in vitro with a single dose of macromomycin(B) (MCR) at 1 mug/ml for 24 hours. This dose, which is cytostatic but not lethal, increased the immunogenicity of the cells. Adoptive transfer of spleen cells sensitized to MCR/TA3-Ha cells evoked an immune response against MCR-treated TA3-Ha cells but not against normal TA3-Ha cells. The therapeutic effect of MCR treatment (in this case) was, to a very small extent, due to the cytostatic action and more profoundly to the increased immunogenicity of the cells so treated.     

Light microscopic and ultrastructural observations of a metastasizing malignant epithelioid schwannoma

The light microscopy and ultrastructure of a malignant epithelioid schwannoma are described. Characteristic cells resembling perineural elements with various degrees of differentiation were observed. Primitive epithelioid cells contained scant ergastoplasm, and few tubules and filaments, but did have abundant free ribosomes and Golgi membranes. Also noted were junctional complexes and focal fusion of plasma membranes, basal laminae were absent. Better differentiated cells were completely limited by a well-developed basal membrane and had an abundance of intracytoplasmic filaments and multiple pinocytotic vesicles. The intercellular ground substance was composed of numerous fine collagen fibrils and amorphous, basement membrane-like, electron-dense material. A striking ultrastructural similarity of the tumor cells to those encountered in ethylnitrosourea-induced malignant schwannomas in rats was noteworthy.     

Mechanism of the hypercoagulation effect of hyperoxia

It was shown in man and rabbits that a 30-minute inhalation of a 100% O2 under normal atmospheric pressure was accompanied by an elevation of the blood coagulation capacity and a sharp reduction of the count of platelets with the change of their structure. The trigger mechanism of the described hypercoagulation effect is possibly the viscous metamorphosis of platelets developing under the effect of oxygen activation of Hageman's factor.