PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “ARTIFICIAL ORGANS”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources
PubMed1980

Old, new and revised aspects of artificial organs.

Retrograde perfusion of the coronary veins with oxygenated blood is effective. Closed chest transarterial left ventricular bypass was developed by Hans Zwart to support the failing left ventricle. Transapical left ventricular bypass started by Alex Kralios, later studied by Jeffrey Peters et al, became effective when filters were introduced into the system--first surviving patient! One must be prepared to support both ventricles. Retrograde transpulmonary bypass (Kralios) is as yet only experimental. The blood is pumped from one occluded pulmonary artery into the aorta. Plasmapheresis removes particles with a molecular weight of 7 to 45,000 which may be harmful in patients with burns or oxygenators since they blind the leukocytes. Starling's Law will regulate the total artificial heart. The future is for the electrohydraulic artificial heart by Robert Jarvik. However, air driven hearts may offer a life of sufficient quality to people now doomed to die. All types of hemodialyzers or peritoneal dialyzers should be made portable or wearable. The "mouse" is a good peritoneal access device. It makes recirculating peritoneal dialysis practical.

Ambulatory Care↗
PubMed1975

[Flow in natural and artificial organs and vessels (author's transl)].

After introductory remarks about the flow phenomena in the human body (separation, dead waters, stagnation regions) and the model simularity conditions, the flow behaviour in arterial bifurcations at pulsatile flow are considered; they are accompanied by the formation of dead waters and secondary flows and therefore they give the danger of atherosclerosis. Then the flow pattern at arterio-venous anastomosis is interpreted with regard to the danger of thrombogenesis. At the selected example of ball prosthesis the flow pattern and the pressure loss of artificial heart valves (aortic as well as mitral valves) are described; the special behaviour of ball valves used as mitral valves is discussed critically. Finally in a view of contribution to the question of the flow-induced blood damage, in extended series of basic tests on models (orifices and perforated discs) the rate of hemolysis was measured depending on the flow; the tests were completed by measurements at rolling pumps, atria of a artificial ventricle and other parts. In order to try an explanation for the flow-induced hemolysis one starts from the influence of the hemodynamic shear stresses on the damage of the erythrocytes; hereby the effect of the frequently repeated passages of the red blood cells through a stenosis (e.g. regurgitation) should be taken into account.

Aortic Valve↗
PubMedDate not supplied

Complex coacervate microcapsules for mammalian cell culture and artificial organ development.

A number of combinations of anionic and cationic polymers, the majority being polysaccharides, were screened to determine their suitability for the development of alternative microcapsule formulations capable of supporting cells. The capsules were taken through a limited optimization and then evaluated on the bases of rupture strength, permeability to albumin, and ability of their components to promote the attachment, aggregation, and function of encapsulated rabbit hepatocytes. The widely used alginate-polylysine capsules were employed as a comparative standard in all tests. A number of the new formulations compared favorably with the standard, and some exhibited superior performance in specific areas. Hepatocyte function, as evaluated by the rate of urea synthesis, showed no significant differences between formulations over a 24-h test period. One formulation, composed of the polysaccharides (carboxymethyl)cellulose, chondroitin sulfate A, chitosan, and polygalacturonate, was found to be superior to alginate-polylysine capsules in the areas investigated and supported the long-term survival and growth of liver endothelial cells.

Animals↗
PubMed1981

The bio-artificial organ: review and progress report.

A definition and a review is given for the bioartificial organ. In addition new developments are reported with the successful lyophilization of enzyme filled RCG with cryoprotective polyethylene glycol (PEG). The successful use of an enzyme reactor consisting of crosslinked fibrin with asparaginase covalently attached is reported in sheep. The small organ (0.4 m2) removes 70% of the animal's asparagine in 6 hours. No enzyme leakage down to 10(-5) units per ml. plasma could be found. The highly preserved substrate affinity of insolubilized asparaginase as well as its high activity and stability when bound to fibrin are additional outstanding features of this system.

Animals↗
PubMedDate not supplied

Impact of United States artificial organ development in Latin America.

The University of Minnesota may be considered the cradle of heart surgery worldwide. That is where Dr. F. John Lewis carried out the first open heart surgery in September, 1952 and repaired an atrial septal defect in a 5 year old girl. Thenceforth, new solutions to allow systematic heart surgeries have been extensively investigated. This requires boldness and imagination. In 1954, Dr. Walton Lillehei, who had been working in Minnesota since after the war, carried out the first surgery with cross circulation using a second person who worked as a circulatory support, while the patient's heart was operated on. In 1955, he started using extracorporeal circulation using an oxygenator developed in association with Dr. Richard de Wall and the roller pump introduced by Michael DeBakey. By 1956 they had already performed 80 surgeries using the bubble oxygenator.

Artificial Organs↗
PubMedDate not supplied

An investigation of blood flow behavior and hemolysis in artificial organs.

In our previous study, in vitro hemolysis tests showed that collision flow against wall roughness had an effect on hemolysis when the flow velocity was more than 3 m/s and surface roughness was more than Ra = 1.54 microm. However, the specific portion of the flow on the wall that induced hemolysis was not clarified. Therefore, the purpose of this study was to present the relationship between flow behavior and hemolysis by means of in vitro tests and computational fluid dynamics (CFD) analysis. We investigated the relationship between the location of surface roughness and hemolysis. In CFD, we investigated the flow behavior on the wall. The highest rate of hemolysis was observed in a region around the center of the surface roughness on the bottom plate. On CFD analyses, the flow behavior included the highest wall shear stress (304 Pa) and the highest flow acceleration (2.8 m/s2) around the center of the bottom plate. Therefore, it is concluded that the causes of hemolysis during collision flow depend upon wall shear stress and flow acceleration.

Artificial Organs↗
PubMed2000

Tissue engineering of artificial organs.

Tissue engineering efforts are currently being undertaken for every type of tissue and organ within the urinary system. Most of the effort expended to engineer genitourinary tissues has occurred within the last decade. Tissue engineering techniques require expertise in growth factor biology, a cell culture facility designed for human application, and personnel who have mastered the techniques of cell harvest, culture, and expansion. Polymer scaffold design and manufacturing resources are essential for the successful application of this technology. In order to apply these engineering techniques to humans, further studies need to be performed with many of the tissues described. The first human application of cell-based tissue engineering technology for urologic applications took place at our institution, with the injection of autologous cells for the correction of vesicoureteral reflux in children. The same technology has been expanded to treat adult patients with urinary incontinence. Trials of urethral tissue replacement with processed collagen matrices are in progress, and bladder replacement using tissue engineering techniques are currently being arranged. Recent progress suggests that engineered urologic tissues may have clinical applicability in the future.

Artificial Organs↗
PubMed2003

Artificial organ treatment for multiple organ failure, acute renal failure, and sepsis: recent new trends.

Sepsis remains the major cause of mortality worldwide, claiming millions of lives each year. The past decade has seen major advances in the understanding of the biological mechanisms involved in this complex process. Unfortunately, no definitive therapy yet exists that can successfully treat sepsis and its complications. At variance with targeting single mediators, therapeutic intervention aimed at the nonselective removal of pro- and anti-inflammatory mediators seems a rational concept and a possible key to successful extracorporeal therapies. A further advantage may lie in the continuous nature of such therapy. With such continuous therapy, sequentially appearing peaks of systemic mediator overflow may be attenuated and persistently high plasma levels reduced. This theoretical framework is proposed as the underlying biological rationale for a series of innovative modalities in sepsis. In this editorial, we will review recent animal and human trials that lend support to this concept. We will also review the importance of treatment dose during continuous renal replacement therapy as a major factor affecting survival in critically ill patients with acute renal failure. Additionally, we will review novel information related to other blood purification techniques using large pore membranes or plasma filtration with adsorbent perfusion. Although these approaches are still in the early stages of clinical testing, they are conceptually promising and might represent an important advance.

Acute Kidney Injury↗