Prevention of balloon damage during initiation of intra-aortic balloon counterpulsation

Damage to an intra-aortic balloon occurred on two occasions in 93 insertion procedures. The complication was recognized before gas embolization occurred, and neither patient suffered ill effects. On both occasions the balloon was holed when pinched by artery forceps applied to the 'dacron' graft.     

Optimization of collimation system parameters of radioisotope tomograph]

An index of completion of phagocytosis was studied for staphylococcus cultures of various biological activity in experiments with surviving polymorphonuclear leukocytes. Among the coagulase-forming staphylococci virulent strains proved to be nonviable in a lesser percentage of cases than the avirulent ones. Coagulase- and mannite-negative cultures proved to be most unstable. Staphylococcus toxin depressed the migration of polymorphonuclear leukocytes to the focus of irritation, inhibited ingestion of the virulent, and, to a lesser degree, of avirulent coagulase-forming staphylococci, but failed to influence the ingestion of coagulase-negative epidermal staphylococci. The influence of staphylotoxin on the phagocytosis completion index was either the minimal or absent entirely.     

The effects of anemia on heme synthesis parameters during lead exposure

The effects of anemia during lead exposures were studied using an infant baboon animal model. When the hemoglobin concentration was reduced to less than 70% of normal, a marked blood lead increase was observed and the free erythrocyte porphyrin value, aminolevulinic acid dehydratase activity and reticulocyte counts increased. Special emphasis should be placed on nutritional effects in lead exposures.     

Morphologic basis of psychoses associated with vascular and senile pathology

The paper deals with a study of 100 patients diagnosed as combined senile and vascular psychoses. It is marked that in classical cases of such combinations the disorder has 3 stages. On the first stage there is a predominance of vascular pathology. After 60 years of age (the second stage) the senile sumptomatology disguises many symptoms of vascular lesions. The third stage is characterized by a vascular catastrophe. In many cases of combined psychoses there may be complications of other somatic pathology and mainly of lung and liver disorders.     

Hypermutability of mouse chromosome 2 during the development of x-ray-induced murine myeloid leukemia

In an effort to identify the precise role of a deletion at regions D-E of mouse chromosome 2 [del2(D-E)] during the development of radiation-induced myeloid leukemia, we conducted a serial sacrifice study in which metaphase chromosomes were examined by the G-banding technique. Such metaphase cells were collected from x-irradiated mice during the period of transformation of some of the normal hematopoietic cells to the fully developed leukemic phenotype. A group of 250 CBA/Ca male mice (10-12 weeks old) were exposed to a single dose of 2 Gy of 250-kilovolt-peak x-rays; 42 age-matched male mice served as controls. Groups of randomly selected mice were sacrificed at 20 hr, 1 week, and then at intervals of 3 months up to 24 months after x-irradiation. Slides for cytogenetic, hematological, and histological examination were prepared for each animal at each sacrifice time. An expansion of cells with lesions on one copy of chromosome 2 was evident in 20-25% of treated mice at each sacrifice time. The majority of such lesions were translocations at 2F or 2H, strongly suggesting hypermutability of these sites on mouse chromosome 2. No lesions were found in control mice. The finding leads to the possibility that genomic lesions close to 2D and 2E are aberrants associated with radiation leukemogenesis, whereas a single clone of cells with a del2(D-E) may lead directly to overt leukemia. The data also indicate that leukemic transformation arises from the cumulative effects of multiple genetic events on chromosome 2, reinforcing the thesis that multiple steps of mutation occur in the pathogenesis of cancer.