In tissue with a distinct orientation of the oxygen supplying structures, the capillaries, a mathematical description of oxygen transport is feasible in terms of two-dimensional diffusion in a plane perpendicular to the capillaries. Muscle tissue is an example of a highly anisotropic tissue. With some additional simplifying assumptions, a solution can be constructed in terms of capillary source...

A novel method was developed for the preparation of highly efficient anion- and cation-exchange microHPLC columns using an on-column polymerization of methacrylates having amine or sulfonic acid functional groups onto monolithic silica capillary columns modified with 3-methacryloxypropyltriethoxysilane as the anchor groups. The chromatographic evaluation of the columns using nucleic acids, nucl...

Lung diffusing capacity for nitric oxide (DLNO) is used to measure alveolar membrane conductance (DMNO), but disagreement remains as to whether DMNO=DLNO, and whether blood conductance (thetaNO)=infinity. Our previous in vitro and in vivo studies suggested that thetaNO<infinity. We now show in a membrane oxygenator model perfused with whole blood that addition of a cell-free bovine hemoglobin (...

Using intravital microscopy in a chronic in vivo mouse model, we studied the demarcation of myocutaneous flaps and evaluated microvascular determinants for tissue survival and necrosis. Chronic ischemia resulted in a transition zone, characterized by a red fringe and a distally adjacent white falx, which defined the demarcation by dividing the proximally normal from the distally necrotic tissue...

BACKGROUND We determined whether pulmonary gas exchange indices during submaximal exercise are different in heart failure (HF) patients with combined post- and pre-capillary pulmonary hypertension (PPC-PH) versus HF patients with isolated post-capillary PH (IPC-PH) or no PH. METHODS AND RESULTS Pulmonary hemodynamics and pulmonary gas exchange were assessed during rest and submaximal exercise...

Capillary filtration is a key area in the understanding of cardiovascular function and has both physiological and pathophysiological relevance in nearly every organ system. This article describes how classic papers in the Legacy collection of American Physiological Society publications can be used in a teaching symposium exploring the evidence supporting current concepts of capillary fluid exch...

This paper presents a mathematical model of the oxygen alveolo-capillary exchange to provide the capillary oxygen partial pressure profile in normal and pathological conditions. In fact, a thickening of the blood-gas barrier, heavy exercise or a low oxygen partial pressure (PO2) in the alveolar space can reduce the O2 alveolo-capillary exchange. Since the reversible binding between haemoglobin ...

A set of indicator-dilution studies of the coronary circulation of the intact functioning heart was carried out in the dog to provide a data base for defining the effect of changes in vasomotor control on the exchange of materials across the myocardial capillaries. The reference substance used was 125I-labeled albumin; the diffusible substance used was 14C-labeled sucrose. Model analyses of the...

To determine the extent and sources of adaptive response in gas-exchange to major lung resection during somatic maturation, immature male foxhounds underwent right pneumonectomy (R-Pnx, n = 5) or right thoracotomy without pneumonectomy (Sham, n = 6) at 2 mo of age. One year after surgery, exercise capacity and pulmonary gas-exchange were determined during treadmill exercise. Lung diffusing capa...