Voiding pressure as it relates to outlet and/or sphincteric resistance

Electrically quantitated and controlled detrusor contraction can produce either minimal or excessive rise in intravesical pressure depending upon openness or occlusion of the bladder outlet. Higher rise in intravesical pressure thus does not imply stronger detrusor contraction but should be viewed as a reflection of the outflow resistance mechanism. Possible damaging hydrodynamic effect of sudden partial or complete functional occlusion of the bladder outlet by intermittent or sustained voluntary sphincter activity is illustrated.     

Persistence of fetal cardiopulmonary circulation: one manifestation of transient tachypnea of the newborn

Five cyanotic newborn infants underwent cardiac catheterization between 8 and 36 hours of age with a tentative diagnosis of cyanotic congenital heart disease. All had normal cardiovascular anatomy. Cyanosis was the result of persistence of fetal cardiopulmonary circulation with right-to-left shunting across the ductus arteriosus. In all infants, cyanosis resolved spontaneously and the infants survived without sequelae. Admission chest roentgenograms of all infants showed marked hyperinflation of the lungs. Except for severe hypoxemia, the clinical presentation, chest films, and course of illness of these infants were consistent with transient tachypnea of the newborn. It is proposed that an increase in pulmonary vascular resistance, due to hyperinflation of the lungs, was the mechanism which reopened the fetal cardiopulmonary circulatory channels and produced hypoxemia, and that these infants suffered from a rare manifestation of a usually benign newborn respiratory condition. Further, given these pathophysiologic mechanisms, the use of continuous transpulmonary pressure gradients in the management of such infants would be contraindicated.     

Erythrocyte basophilic stippling in the Mongolian gerbil

Basophilic stippling of the circulating erythrocytes is characteristic of the Mongolian gerbil. Its enzymatic digestion along with the concomitant removal of diffuse erythrocytic polychromasia by the action of ribonuclease demonstrates that it represents microscopically visible aggregates of cytoplasmic ribonucleoprotein, presumably of ribosomal origin. Up to 40% of the total circulating erythrocytes may be stippled in foetal and newborn animals. There is then a progressive decline in incidence until adult levels are attained at least by 20 weeks of age. The bone marrow of the adult gerbil contains a higher proportion of stippled red cells than the circulating blood. The stippling can be either coarse or fine and observable in both polychromatophilic and orthochromic cells. It is suggested that erythrocytes with basophilic stippling are relatively immature red cells still demonstrating remnants of cytoplasmic ribonucleoprotein.     

The clinical significance of granulocyte colonies in bone marrow cultures

The culture system for in vitro evaluation of "colony forming units - culture (CFU-c)" is briefly outlined. This method offers a new approach to studies of proliferation and differentiation of hemopoietic progenitor cells, especially in disorders of granulopoiesis. From available published data it is evident that quantitation of CFU-c is also an indicator of diagnostic and prognostic value for assessment of various types of leukemia. The CFU-c assay has furthermore been introduced to test the viability and proliferating capacity of cryopreserved bone marrow, especially with a view to possible transfusion of stored autologous bone marrow as an adjuvant to cytostatic therapy.     

Gas exchange during exercise in healthy people II. Venous admixture

1. Venous admixture/cardiac output ratio (Qva/Qt) has been measured in twenty-four healthy volunteer subjects of both sexes aged 20-71 years, at rest and during the steady state of treadmill exercise at two rates of work, and breathing air and breathing oxygen. 2. With oxygen breathing, Qva/Qt was considerably less during exercise than during the time subjects were taking either normal or deep breaths of oxygen at rest, and did not significantly increase with the intensity of exercise. It is postulated that the increase in ventilation during exercise opens most or all of those alveoli which, during oxygen breathing at rest, close because of critically low ventilation/perfusion (V/Q) ratios. 3. With air breathing, Qva/Qt fell from rest to exercise (especially in older subjects), presumably due to improved ventilation of alveoli at the lung bases. With an increase in work rate Qva/Qt increased in all age groups. This increase was not due to increase in the shunt fraction (Qs/Qt), nor to limitation of diffusing capacity; it arose from an increase in V/Q variance. 4. Equations have been derived for the prediction of normal Qva/Qt during exercise, with or without correction for the effects of increasing pulmonary capillary temperature. These effects do not materially influence the accuracy of prediction, but may be relevant to some of the interpretations. In particular, they provide a further indication that Qs/Qt probably cannot be measured by breathing oxygen at rest, even in deep breathing.     

Morphological effects in rats following a 22-day space flight

A morphological examination of 27 rats flown onboard the biosatellite and sacrificed on the 1st-2nd and 26-27th postflight days demonstrated no significant changes in the structural organization of the vital organs and systems of the animal body. It was, however, found that the space exposure induced morphologically detectable changes in the musculo-skeletal system, hemo- and lymphopoiesis, hypothalamic-pituitary-adrenal system and the juxtaglomerular apparatus of the kidneys. The changes were reversible and nonspecific, and could be seen in animals exposed to ground-based hypokinetic and other stress experiments. Postflight the animals developed some reactions that were similar to those in humans. This helps to identify the morphological substrate of certain changes in the human body and to investigate their pathogenesis.