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Biomedical subjects

H Unruh

Publications and source records attributed to H Unruh.

26 records · Page 2Linked to original sources
PubMed1990

hemofiltration reverses left ventricular dysfunction during sepsis in dogs.

Depressed left ventricular (LV) contractility in sepsis has been ascribed to the presence of circulating cardiodepressant substance (filterable cardiodepressant factor in sepsis [FCS]); however, this finding is controversial. The authors hypothesized that if a decrease in LV contractility indeed occurred due to a circulating depressant substance, then removal of this substance by hemofiltration would reverse by dysfunction. In this study, LV mechanics were examined before and after hemofiltration in anesthetized dogs during continuous intravenous infusion of live Escherichia coli. Left ventricular anterior-posterior and apex-base dimensions were measured by subendocardial ultrasonic crystal transducers implanted 4 weeks before the experiments. Left ventricular contractility was determined from the end-systolic pressure-dimension relationship. The slope of this relationship (Emax) is an index of contractility. After 4 h of sepsis, Emax was reduced by one half. Hemofiltration resulted in a return of Emax to control values. The FCS activity in the plasma was also assessed by the percent reduction in isometric contraction of electrically stimulated, isolated right ventricular trabeculae obtained from nonseptic dogs. The FCS activity reached a peak 4 h after sepsis and was reduced after 2 h of hemofiltration. The results show that during experimental sepsis, a circulating substance of less than 30,000 d produces a decrease in LV contractility and that this LV dysfunction may be improved by hemofiltration.

Animals↗
PubMed1986

Mediastinal assessment for staging and treatment of carcinoma of the lung.

Invasive diagnostic procedures for mediastinal assessment, such as mediastinoscopy, are necessitated by the importance of staging lung cancers, both to plan the treatment and to estimate the prognosis. Other noninvasive techniques may complement or be substituted for mediastinoscopy under certain specific clinical settings. Thus with the introduction of newer diagnostic technologies, such as computed axial tomography, the strategy for mediastinal assessment should be continually reevaluated. In this review, the diagnostic sensitivity, specificity, and overall accuracy of various techniques reported in the literature are examined to elucidate their current roles in assessing the mediastinal involvement in patients with lung cancer.

Gallium Radioisotopes↗
PubMed1984

Effect of hypoxic hypoxia on systemic vasculature.

Effects of hypoxic hypoxia (HH) on cardiac output (CO), CO distribution, arterial and venous pressure-flow curves, vascular compliance, vascular time constant (tau), and resistance to venous return (RVR) were evaluated on six dogs. The vascular bed was isolated into four compartments depending on venous drainage: superior vena cava (SVC), splanchnic, renal and adrenal, and the remainder of the inferior vena cava (IVC). Low arterial O2 content and PO2 produced a threefold increase in CO at the same mean arterial pressure and a significant redistribution of CO to the SVC. Arterial pressure-flow curves decreased their slope (i.e., flow resistance) by a factor of two in the IVC and renal beds and by a factor of three in the splanchnic and SVC beds. Venous pressure-flow curves for the animal also decreased their slope significantly. HH causes a twofold increase in venous compliance and in mean venous pressure; tau did not change, but RVR halved. Seventy percent of the CO increase is explained by the increase in mean venous pressure and 30% by the reduction in RVR.

Acid-Base Equilibrium↗
PubMed1983

The effect of lung edema on pulmonary vasoactivity of furosemide.

Previous data suggest that furosemide improves gas exchange in pulmonary edema by preferential perfusion of nonedematous lung units. To test whether this is a direct effect of furosemide on the pulmonary vasculature as opposed to a secondary phenomenon resulting from the known peripheral effects of this drug, the effect of furosemide on the pressure-flow characteristics of the pulmonary vasculature was studied in six isolated perfused canine lungs with different degrees of gravimetrically determined edema. Furosemide shifted the pressure-flow curve by decreasing the mean intercept or average closing pressure of the pulmonary vascular bed from 13.8 +/- 5.3 to 9.5 +/- 5.4 cm H2O and the zero-flow critical closing pressure from 9.3 +/- 4.3 to 4.7 +/- 3.5 cm H2O (P less than 0.05). The slopes of these curves did not change between control and furosemide treatment. The decrease in intercept and the decrease in zero-flow critical closing pressures were closely correlated with the increase in edema (r = 0.895 for average closing pressure and r = -0.928 for critical closing pressure) (P less than 0.05). Furosemide doubled the pulmonary blood flow in the isolated lobe for the same driving pressure and the greater the amount of lobar edema the less pronounced was this furosemide-associated increase in blood flow. This direct effect of furosemide on the pulmonary vasculature could explain the improved gas exchange seen before a decrease in pulmonary edema, since this pulmonary vasoactivity would result in preferential perfusion of nonflooded alveolar units.

Animals↗
PubMed1979

Postmastectomy lymphangiosarcoma: experience with three patients and electron microscopic observations in one.

The clinical features are presented of three patients in whom lymphangiosarcoma developed after radical mastectomy followed by local irradiation. The median time between radical mastectomy and the diagnosis by biopsy of lymphangiosarcoma was 9.9 years. No form of therapy, including high-dose combination chemotherapy, appeared able to control the disease. All three patients died with residual lymphangiosarcoma and in two it was the direct cause of death. These results stress that prevention of postmastectomy lymphangiosarcoma is vital. This can be accomplished by avoiding radical mastectomy followed by local irradiation. Ultrastructural observations in one case suggest that the tumour has a primitive vasoformative origin.

Adult↗
PubMedDate not supplied

Pulmonary endothelial cell function after modified Eurocollins solution infusion.

Eurocollins solution is commonly used in preparation for lung transplantation and is known to increase the pressure cost of perfusion by causing both vascular obstruction and increased tone. In this study we assessed whether Eurocollins solution had a direct effect on the pulmonary endothelial cell by causing increased permeability or by depressing its metabolic integrity. The effect of 4 degrees C Eurocollins solution on transvascular fluid flux properties and on angiotensin-converting enzyme function were assessed. Eurocollins solution had no effect on the microvascular filtration coefficient or on the critical capillary pressure, both very sensitive indicators of the permeability characteristics of the endothelium. The inert angiotensin-converting enzyme substrate [3H]BPAP had a peak metabolism of 83% and 81%, respectively, and an average metabolism of 82% both before and after Eurocollins solution infusion. The first order enzyme rate constant, Vmax/Km, was, however, reduced by 22% with Eurocollins solution perfusion. Eurocollins solution does not therefore cause increased endothelial permeability and hence a permeability type of pulmonary edema. The reduced first order rate constant of the enzyme, in the presence of normal peak and average metabolism, may be partially accounted for by a reduction in intravascular surface area available for enzyme substrate interaction.

Animals↗