Digital low-pass filtering

Random noise beyond the maximum signal frequency of the imaging system can be removed by low-pass filtering without compromising signal transmission.     

Effects of hypoxia on the hemodynamic actions of prostaglandin E1

The effect of prostaglandin E1 (PGE1) on central and peripheral hemodynamics was studied in seven conscious dogs under conditions of normoxia and hypobaric hypoxia to ascertain if hypoxia attenuated the cardiovascular actions of PGE1. Silastic catheters were chronically implanted in the pulmonary artery, left atrium, and aorta. Acute hypoxia was produced in a hypobaric chamber maintained at 446 mmHg pressure (14,000 feet). PGE1 at sea level (normoxia) resulted in significant increases in heart rate, cardiac output, left ventricular stroke work and pulmonary blood volume as well as significant decreases in aortic, pulmonary arterial, and left atrial pressures. During hypobaric hypoxia, PGE1 produced essentially identical effects on all hemodynamic parameters except pulmonary blood volume and pulmonary arterial pressure where marked attenuation of PGE1 action occurred.     

Acute penetrating tracheal trauma

Four hundred seventy blood access procedures performed on 170 dialysis patients during the period 1962-1975 have been analyzed according to survival of access with respect to age, sex and cause of failure. Subcutaneous forms of blood access have a significantly longer life and are more free of complications than external shunts. Although the mode of access can now be tailored to the individual patient, the arterio-venous fistula remains the least expensive and simplest surgical procedure. It should therefore remain as the first choice of access for most patients.     

Blood levels of testosterone and dihydrotestosterone in breast cancer

In concentration of testosterone and dihydrotestosterone in blood plasma was determined in 21 healthy females and in 37 patients with breast cancer. The method of competitive binding of tritium labelled testosterone and dihydrotestosterone by specifically binding beta-globulin was employed. It was found that healthy females fail to show any age variations in the concentration of the hormones under investigation in blood. In menopausal patients testosterone concentration tends to decrease in cancer dissemination.     

Treatment of intestinal paresis in children

In the paper, a clinical experience with treatment of intestinal paresis in 545 children, aged from 1 day to 13 years, including 225 children operated upon for peritonitis is summarized. The authors differentiate 3 stages in the development of intestinal paresis depending on the degree of intensity of systemic and local disturbances. The employed methods of treatment in intestinal paresis were classified by the principle of their effect as 3 groups. Application of some or other method of the paresis therapy is determined by the stage of its development. In treatment of postoperative intestinal paresis a continuous peridural blockade is considered to be the method of choice. Utilization of the latter enabled the authors to reveal a number of postoperative complications: mechanic intestinal obstruction, incompetent anastomosis, etc.     

Change in the metabolism and toxic effect of benz(a)pyrene by its metabolites and a series of phenols

Effects of some phenols and polycyclic aromatic hydrocarbon derivatives on benz(a)-pyrene metabolism have been studied in the microsomal system isolated from the mouse embryonic cell cultures. The rate of benz(a)pyrene metabolism was shown to depend on the structure and concentration of the agents added. The toxic effect of benz(a)pyrene was summed up with that of either agent studied (except ionol) added simultaneously to the cell culture.     

Serum lysozyme as a marker of host resistance. II. Patients with malignant melanoma, hypernephroma or breast carcinoma

Serum lysozyme activity was measured in groups of untreated patients with malignant melanoma, hyperneophroma and breast carcinoma. Significant elevation of serum levels of the enzyme was confined to patients with localized disease. In the presence of metastatic disease such elevation was not detected. The rise in serum lysozyme activity was not due to renal damage or any infective process and in the case of malignant melanoma was shown to be associated with infiltration of the tumour mass by macrophages. In vitro studies demonstrated that the macrophages resident in a tumour mass are responsible for relasing lysozyme in large amounts. It is proposed that the elevation of serum lysozyme in these cases may be an indicator of macrophage-mediated host resistance and that the measurement of macrophage products such as lysozyme in the extracellular fluid may under well defined conditions provide useful clinical information concerning host reactions.     

Phagocytosis and erythroblastosis. I. Modification of the neonatal response by promethazine hydrochloride

Phagocytic cells were obtained from children at ages comparable to those at which the disease is most commonly seen during pregnancy. The effect of P-HCl on the phagocytic action of these cells on opsonized red blood cells was studied in vitro.