Biomedical subjects

D Stoop

Publications and source records attributed to D Stoop.

3 recordsLinked to original sources

PubMed2000

Effects of Re-arterialization on early graft function and regeneration in the rat model of heterotopic auxiliary liver transplantation.

In the rat model of heterotopic auxiliary liver transplantation, graft re-arterialization may influence the outcome of inter-liver competition. This was investigated in the current study using two transplanted groups with or without graft re-arterialization. Immediately after reperfusion, the re-arterialized grafts showed significantly higher bile flow rate and bilirubin excretion than the grafts without re-arterialization. DNA synthesis rate was also increased more drastically in the re-arterialized group following the transplantation. Without re-arterialization, the rats developed more pronounced cytolysis and cholestasis. Among the long-term survivors, all healthy re-arterialized grafts regenerated, whereas 5/6 non-re-arterialized grafts atrophied. These data demonstrate that the re-arterialization increases graft survival by improving early hepatic function, enhancing regenerative response and preventing post-transplant biliary complications in this rat model.

Animals↗

PubMed1976

Quantitative electrocardiography during extended space flight: the second manned Skylab mission.

To assess the effects of space flight on cardiac electrical properties, vectorcardiograms (VCG) were obtained on the Skylab crew at regular intervals during the 59-d flight (SL3) and during the pre- and postflight periods. The Frank lead system was used and observations were made at rest; during 25%, 50%, and 75% of maximum exercise; during a short pulse of exercise (150 W, 2 min); and after exercise. Data from 47 in-flight tests were analyzed by computer and compared to preflight and postflight values. A statistically significant increase in QRS maximum vector magnitude (all SL3 crewman); and an increase in resting PR interval (all SL3 crewmen) occurred. During exercise, the PR interval did not differ from preflight. Exercise heart rates in flight were same as preflight, but increased in the immediate postflight period. No major changes in QRS, T, or ST vector direction occurred. The scientist pilot had premature ventricular beats sporadically during the flight. This astronaut also had intermittent periods of atrioventricular junctional rhythm throughout the flight. The increase in QRS maximum vector magnitude resembles the electrocardiographic changes associated with athletic conditioning and may be related to increased ventricular volume secondary to centripetal shifts of fluid and/or the in-flight isotonic exercise program. Prolongation of the PR interval at rest with normalization of exercise suggests that there was increased vagal tone or suppressed sympathetic influence during the flight.

Adult↗

PubMedDate not supplied

Quantitative electrocardiography during extended space flight.

To assess the effects of prolonged space flight on the electrophysiological properties of the heart, vectorcardiograms (VCG) were obtained on the Skylab crews at regular intervals during flight and the pre- and postflight periods. The VCG signals were telemetered from Skylab and analyzed by digital computer. Conventional 12-lead electrocardiograms were derived from the VCG signals by a lead transformation program. Standardized exercise loads were incorporated into the experiment protocol to increase the sensitivity of the VCG for effects of deconditioning and to detect susceptibility for arrhythmias. In Skylab II, 24 preflight, 21 inflight, and 19 postflight experiments were analyzed. Statistically significant inflight changes observed in two or more crew members included: decreased resting heart rate, increased QRS duration, anterior shift QRS vector, increased QRS vector magnitude, anterior shift T vector, and increased T vector magnitude. One astronaut had occasional premature ventricular contractions (PVC) during the pre- and postflight phases. He had a single episode of multiple PVC's during heavy-load exercise testing in flight. A second astronaut had no arrhythmia during pre- or inflight testing. On postflight day 21 he had multiple PVC's and salvos of ectopic ventricular beats. He has had no recurrence of the arrhythmia. With the exception of the cardiac arrhythmias, no deleterious electrophysiological changes were observed during Skylab II.

Arrhythmias, Cardiac↗