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Biomedical subjects

T Kolobow

Publications and source records attributed to T Kolobow.

At least 91 records · Page 5Linked to original sources
PubMed1976

Fresh platelet-rich plasma from a flow-through centrifuge for lamb heart perfusion at 13degrees C. Protective effect of added erythrocytes.

Isolated lamb hearts perfused at 13degrees C. with acellular perfusates developed progressive intersitital edema and a rise in vascular resistance. They did not exhbit any electrical or mechanical activity. In contrast, hearts perfused with whole fresh blood remained well preserved, had no edema or change in vascular resistance, and contracted vigorously while being perfused at 10degrees and 13degrees C. This study was designed to determine which particular component(s) of whole blood contributed to improved cardiac preservation. Isolated lamb hearts were perfused for 18 hours at 13degrees C. with plasma containing platelets and some or no red blood cells. Continuously fresh plasma was obtained from a donor animal by means of a flow-through centrifuge. Hearts perfused at 13degrees C. with fresh plasma of either low or high platelet count contracted during the initial 2 to 4 hours of the perfusion only and were as poorly preserved as hearts perfused with acellular microfiltered plasma. A hematocrit value of 2 to 5 per cent in the plasma perfusate resulted in the hearts being preserved almost as well as with fresh whole blood; they showed a forceful cardiac activity at 13degrees C., there was no edema, the vascular resistance was stable, and after rewarming they had good ventricular function. The improvement in cardiac preservation brought about by addition of a minimal amount of red blood cells suggests a specific effect of erythrocytes on the cardiac microcirculation.

Animals↗
PubMed1975

Relative thrombogenicity of polydimethylsiloxane and silicone rubber constituents.

Medical grade silicone rubber (MGSR) is composed of polydimethylsiloxane (PDMS) as well as silica filler, oxidation products from the curing process, and other components. In a test that excludes air-blood interfaces, PDMS radiation cured under nitrogen has a whole blood clotting time 22% longer than MGSR. Curing the PDMS under oxidizing conditions maintains a 10% prolongation, but addition of silica filler to the PDMS returns the clotting time to that of MGSR. Extracting MGSR with solvents other than water appreciably lowers the clotting time. These results indicate the "pure" PDMS has an intrinsically high thromboresistance. Thrombogenicity is increased by the use of silica filler and oxidizing cure, as in MGSR.

Biocompatible Materials↗
PubMed1975

Follow-up respiratory function of a patient treated with a membrane lung.

A patient in remission from acute lymphoblastic leukemia developed the adult respiratory distress syndrome. Despite "optimal respiratory therapy" and ventilatory assistance with 100 per cent inspired O2 (fraction of inspired O2 = 1) and 15 cm of positive end-expiratory pressure, the patient's arterial PO2 remained at 33 mm Hg. Prepulmonary venovenous respiratory support was given for 10 days with a spiral coil membrane lung. The data document the sequential improvement in respiratory function and suggest that despite the severe lung damage that may occur during the adult respiratory distress syndrome treated with prolonged high inspired concentration of O2, if the patient's lungs recover from the acute process, the respiratory system can recover so that there is little, if any, permanent restriction of the subject's activities as a result of respiratory impairment.

Child↗
PubMed1975

Acute respiratory failure. Survival following ten days' support with a membrane lung.

An 11-year-old boy with acute lymphoblastic leukemia in remission developed a bilateral pneumonia which rapidly progressed to acute respiratory failure. During 9 days of intensive therapy the patient's respiratory status progressively deteriorated. When it became impossible to maintain the arterial oxygen tension (PAO2) above 40 mm.Hg by conventional means, extracorporeal blood-gas exchange with a membrane lung was begun. After 5 days of bypass the patient's respiratory function began to improve, and he was weaned from the membrane lung on the tenth day. Seven days later he was discharged from the hospital and is currently in excellemt health 23 months after bypass. This perfusion, the longest successful effort to provide respiratory assist with a membrane lung, attests to the efficacy of this therapeutic modality.

Acute Disease↗
PubMedDate not supplied

The Ito "Flow-Through" Centrifuge. A new device for long-term (24 hours) plasmapheresis without platelet deterioration.

An efficacious procedure for continuous plasmapheresis in long-term extracorporeal circulation has not yet been devleoped. This technique could be important in plasma exchange or cross-exchange and in artificial organ support if it could be accomplished safely using heparin as the anticoagulant. When sheep were connected to the Celltrifuge for 23 hours and administered 150 units/kg per hour heparin anticoagulant, we found gross platelet clumping in separated plasma and a 60 per cent fall in platelet count. When 120,000 units of heparin were directly injected into the centrifuge bowl at the onset of the centrifugation followed by hourly heparin administration at 500 units/kg, there was no platelet clumping but the platelet count fell to 52 per cent. Under identical conditions the Ito Flow-Through Centrifuge, a new continuous flow centrifuge with no rotating seals, was used. We found no platelet aggregates and no drop in platelet count, and there was a 100 per cent recovery of platelets in the separated plasma. Platelets sampled from arterial blood and separated plasma were found to have normal function in vitro, and responded 100 per cent to both collagen and ADP. These results indicate that the Ito Flow-Through Centrifuge can be used in plasmapheresis with heparin anticoagulation with no donor platelet loss and normal function in separated plasma.

Animals↗