Robert M. Winslow

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Pulmonary gas exchange was studied on members of the American Medical Research Expedition to Everest at altitudes of 8,050 m (barometric pressure 284 Torr), 8,400 m (267 Torr) and 8,848 m (summit of Mt. Everest, 253 Torr). Thirty-four valid alveolar gas samples were taken using a special automatic sampler including 4 samples on the summit. Venous blood was(More)
As part of the American Medical Research Expedition to Everest in 1981, we measured hemoglobin concentration, red cell 2,3-diphosphoglycerate (2,3-DPG), Po2 at which hemoglobin is 50% saturated (P50), and acid-base status in expedition members at various altitudes. All measurements were made in expedition laboratories and, with the exception of samples from(More)
The inter-relationship between the interior subunit interfaces and the exterior diphosphoglycerate (DPG) binding region of the hemoglobin tetramer and the effects of a specific N-terminal acetylation on tetramer assembly have been evaluated. Tetrameric fetal hemoglobin F in the liganded state was found to dissociate to dimers much less than previously(More)
Cell-free hemoglobin's (CFH) high affinity for nitric oxide (NO) could limit CFH's use as an oxygen-carrying blood replacement fluid because it scavenges NO, causing vasoconstriction and hypertension. However, the extent to which perivascular NO levels change following intravascular administration of hemoglobin (Hb) with different molecular dimensions(More)
To assess O2 delivery to tissue by a new surface-modified, polyethylene glycol-conjugated human hemoglobin [MP4; Po2 at 50% saturation of hemoglobin (P50); 5.4 mmHg], we studied microcirculatory hemodynamics and O2 release in golden Syrian hamsters hemodiluted with MP4 or polymerized bovine hemoglobin (PolyBvHb; P50 54.2 mmHg). Comparisons were made with(More)
A precise and rapid procedure employing gel filtration on Superose-12 to measure the tetramer-dimer dissociation constants of some natural and recombinant hemoglobins in the oxy conformation is described. Natural sickle hemoglobin was chosen to verify the validity of the results by comparing the values with those reported using an independent method not(More)
Changes in mean arterial pressure were monitored in rats following 50% isovolemic exchange transfusion with solutions of chemically modified hemoglobins. Blood pressure responses fall into three categories: 1) an immediate and sustained increase, 2) an immediate yet transient increase, or 3) no significant change either during or subsequent to exchange(More)
Haemoglobin-based oxygen carriers can undergo oxidation of ferrous haemoglobin into a non-functional ferric form with enhanced rates of haem loss. A recently developed human haemoglobin conjugated to maleimide-activated poly(ethylene glycol), termed MP4, has unique physicochemical properties (increased molecular radius, high oxygen affinity and low(More)
The microvascular effects and hemodynamic events following exposure to normobaric hyperoxia (because of inspiration of 100% O2) were studied in the awake hamster window chamber model and compared with normoxia. Hyperoxia increased arterial blood Po2 to 477.9 +/- 19.9 from 60.0 +/- 1.2 mmHg (P < 0.05). Heart rate and blood pressure were unaltered, whereas(More)