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At least 523 records · Page 29Linked to original sources
PubMed1985

[Microbial colonization of coating and building materials in contact with drinking water. 11. Long-term studies of a drinking water reservoir with polyester isolation].

Building materials of drinking water reservoirs can support a microbial growth as shown in former communications. A new case is presented, where the microorganisms used the polyester isolation as carbon source. The isolation was installed between two concrete layers of a drinking water reservoir. The organic substances were identified by chemical analyses.

Bacteria↗
PubMed1979

[Comparative evaluation of biodestruction of polyurethanes synthetized on the basis of simple and complex polyesters].

In model liquids and experimental animals (rats, rabbits) with the aid of physico-mechanical and histological methods (using interferentially polarizating microscopy) a comparative evaluation was made of the biodestruction of polyurethanes from synthetized simple and complex polyesters. The tissue reaction to intra-abdominal, intramuscular and subcutaneous implantation of perforated stripes of A-19 and Nr. 36 polymer was moderate. Two weeks post-operative increased volumetric biodestruction of the polymers was observed. The course was different in various standards and depended upon the chemical structure of the polymers. Taking into account the slight macrophage tissue reaction, in counterdistinction to the significant volumetric biodestruction which envolved the entire width of the polymer strip, it is assumed that the destruction of the investigated polyurethane composition (adhesive KL-3) takes place by hydrolysis 3 to 6 months post-implant.

Animals↗
PubMed1978

Use of a polyester fiber sponge as an adjunct in the treatment of psoriasis.

Twenty patients with symmetric lesions of psoriasis were asked to use a polyester fiber sponge in addition to their other anti-psoriatic medications. The sponge was used to remove scales from those lesions on the left side only. The hypothesis was that removal of scales would enhance penetration by topical corticosteroid and/or coal tar preparations. At the end of four weeks, as well as at each weekly evaluation, all patients showed a statistically significant difference between the treated and control sides. In 70 percent of the subjects, results were graded good to excellent when the treated side was compared with the control side after four weeks' evaluation.

Administration, Topical↗
PubMed1983

Designing polyester vascular prostheses for the future.

For 30 years polyester textile materials in tubular form have been used in vascular surgery for the replacement and by-pass of arteries. Initially such medical devices were implanted to maintain the distal blood flow of atherosclerotic patients for a number of months. Today, with prognoses in excess of 10 or 15 years, and with implantation in younger and younger patients, this particular end use is possibly one of the most demanding applications for a textile product. The paper describes the current manufacturing techniques and provides detailed information about the wide variety of filaments, yarns and fabrics used in the production of current commercial devices. By reviewing the mechanical and clinical performance of available designs against the criteria of an 'ideal' prosthesis, the objective of this paper is to assist surgeons in making clinical decisions, to provide the textile and medical products industries with directions for future design improvements, and to support standards writers in their formidable task of establishing a rational standard for vascular repair devices.

Blood Vessel Prosthesis↗
PubMed1983

[Inflammatory reaction to polyester material in the guinea pig. IV. Production and liberation of beta glucuronidase and lactate dehydrogenase by peritoneal macrophages in culture].

Peritoneal macrophages obtained from guinea pigs intraperitoneally injected with minced polyester threads with saline, and from control animals were cultivated and the activities of the lysosomal enzyme beta-glucuronidase and of the cytoplasmic enzyme lactate dehydrogenase were determined in the cells and in the culture media. The production and particularly the release into the medium of beta-glucuronidase increased in the cultures from the treated animals; the LDH production was also markedly increased, and the enzyme was partly lost into the medium, suggesting that the injection of Mersilene into the guinea pigs markedly induces these enzymes in the phagocytes and at the same time probably increases the leakiness of their cell membrane.

Animals↗
PubMed1983

[Inflammatory reaction to polyester material in the guinea pig. V. Semiautomatic determination of peritoneal cell volume].

The volume of the peritoneal cells of guinea pigs treated with injections of 1) minced polyester threads (Mersilene), 2) saline, and of untreated animals, has been determined utilizing a Coulter Counter coupled with a pulse height analyzer. The volumetric test on the whole cell population has emphasized a distinctly bimodal distribution, due to the presence of two cellular types picked out as first peak (P 1 degrees) and second peak (P 2 degrees), while the non-adherent cells (CNA) have shown an unimodal distribution. Statistically significant difference in the mean volumes have been found between the P 1 degrees and P 2 degrees cells and between the CNA and P 1 degrees cells. The percentage of CNA in the whole cell population significantly decreases in "Mersilene"-treated guinea pigs.

Animals↗
PubMed1982

[Ultrastructure of the new endothelium in polyester aortic prosthesis].

The development of a new intima in polyester prostheses Dallon implanted into the abdominal part of dog's aorta was tested in the scanning and transmission electron microscope. It was proved that during the first month of the experiment morphoetic elements of blood appeared on the graft surface and later within 36 months smooth muscle cells, collagen fibres and small amounts of elasticin could be found. The process of endothelialization began in the 4 month and after 12 months the graft was totally covered by endothelium. The picture in the SEM especially in the central part differed from the picture of normal arterial endothelium.

Animals↗
PubMed1978

[Physical and biological examinations of polyester electret foil. Preliminary report].

The results of tissue reaction to polyester thermoelectret foil samples are evaluated. The electrostatic measurement of the foils was performed before implantation. The experimental animals were divided into four groups depending on the surface charge density of the foils. The autopsy of the animals was performed three days after the operation. The tissues of close contact to the foil were examined under the microscope and the electrostatic measurement of the foils.

Animals↗
PubMed1980

[Effect of biological fluids on the electrostatic properties of polyester foil electrets].

Thermoelectrets of "Hostaphan" polyester foil in two biological liquids, plasma and Ringer liquid, were investigated. Electrostatic parameters of the specimen immersed in the liquids at 37 degrees C as a function of the immersing time were studied. The following parameters were measured: the surface charge density, the excess charge, the polarization and the surface charge distribution along the specimen diameter before and after the immersing in the liquids. From the thermostimulated depolarization studies it appeared that, due to the immersing in the liquids, the charge is removed from the specimen surface, but stays in the bulk.

Chemistry Techniques, Analytical↗
PubMed1993

[Assessment of the plasma phase of coagulation in platelet-rich plasma after passage through a special polyester filter].

The authors have examined the alterations in the coagulation pathway of plasma filtered through a polyester filter coated by a hydrophilic polymer. The activation of the coagulation pathway was evaluated by measuring prothrombin time, activated partial thromboplastin time, coagulation factors and fibrinopeptide A. The results obtained demonstrate that the examined filter does not induce significative activation of the coagulation pathway.

Blood Coagulation↗
PubMedDate not supplied

Autologous arterial grafts grown on polyester molds: observations of graft growth and patency in experimental animals.

Tissue molds consisting of polyester mesh jackets covering silicone mandrils were implanted subcutaneously in dogs. When a sufficiently strong layer of connective tissue had formed around the molds they were excised and the mandrils removed. The process of tissue formation was observed and recorded. The forms were used as grafts in either the abdominal aorta or the femoral artery of the dog. Six grafts 10 mm inner diameter, six grafts 6 mm inner diameter and 26 grafts 3 mm inner diameter were implanted. After 4.5 months 80% of the 10 mm grafts, 83% of the 6 mm grafts, but only 4% of the 3 mm grafts remained patent. Histological studies at various intervals after grafting revealed gradual thickening of the neointima. The reason for graft failure was thrombus formation originating at the line of anastomosis.

Animals↗
PubMed1997

Evaluation of a polyester collagen-coated heparin bonded vascular graft.

This animal study was designed to compare a collagen coated heparin bonded vascular graft (CHG) versus a collagen coated vascular graft (CG) regarding intraoperative blood loss and healing process. 24 polyester vascular grafts (12 CHG and 12 CG) of 6 mm in diameter and 5 mm in length were implanted between the common iliac and external iliac artery in 12 adult dogs. The grafts were explanted between the first and the sixth months which followed the implantations. The healing process was observed by gross examination, microscopic and scanning electron microscopic examination. Prostaglandin PGE2, TXB2, 6 keto PGF1 alpha and PGF2 alpha were measured by radioimmunologic assay from samples retrieved from the medium part of the graft. During implantation, there was no notable difference in blood loss through the graft. At the time of explantation, 20 grafts were patent (10 CHG, 10 CG). In both grafts, the healing process developed progressively between 2 and 6 months and 90% of the internal surface of the grafts were covered with endothelial like cells. At 6 months, the internal layer was thinner in heparinized graft. PGI2 secretion was found with the two types of grafts. In conclusion, the present study showed no difference in the blood loss or healing characteristic of CHG and CG except for a potentially thinner internal layer with CHG. Comparative studies in humans are necessary to evaluate the potential benefit of heparin bonded graft in clinical practice.

6-Ketoprostaglandin F1 alpha↗
PubMedDate not supplied

[Clinical assessment of calvarial reconstruction with autogenic bone graft or implants of acrylate and polypropylene-polyester knitted fabric].

During the period between 1972-1992 32 patients with calvarial bone defects were treated by 35 reconstructions. The paper presents early and late results of various methods of reconstructions. Very good late results were achieved in all 5 patients in whom the defects were reconstructed with autogenic split cranial bone graft. There were equally good results in 19 from 22 patients in whom acrylic and propylene-polyester implants were applied. Total resorption of autogenic split iliac and split rib bone graft were observed in all 5 patients in whom skull defects were filled with this tissue.

Acrylates↗
PubMed1997

[Clinical evaluation of a polyester vascular prosthesis impregnated with albumins from material of the Vascular Surgical Clinic AM in Wrocław in the years 1994-1997. Introductory report].

The aim of this work was clinical evaluation of impregnated (albumins) prostheses of Polish production. Those prostheses were compared with polyester knitted vascular prostheses. We evaluated a group of 48 patients to whom prostheses covered with albumins were implanted and 52 patients to whom nonimpregnated prosthesis was implanted in 1994-1997. The prostheses were implanted in aortofemoral segment. The achieved results prove the good quality of the impregnated prosthesis and its high value for vascular reconstructive surgery.

Albumins↗
PubMed1997

Microanatomy of the vasa vasorum of the human thoracic aorta: a study utilizing a polyester resin casting technique.

We have studied the vasa vasorum of the human thoracic aorta using a polyester resin casting technique, coupled with the tissue clearing method of Spalteholz. We found that the vasa vasorum originated from intercostal arteries. They ramified and formed networks within the aortic adventitia and the outer layers of the media. Venous networks were identified in the adventitia as wall. In addition to being a usefull research tool, the methodology utilized in this study produces specimens that can be used in teaching vascular anatomy to medical students.

Adult↗
PubMed1991

[Toxicological evaluation of saccharose carbonic acid esters in basic subchronic feeding trials with rats. 1. Effect of saccharose fatty acid polyester].

Groups of male and female rats received a sucrose fatty acid polyesters containing product (SPE) in their diet for 13 weeks at levels of 0, 5, 10 or 15%. Additional groups were pair-fed to the high-dose SPE-group (standard diet, 92.5%) or given food containing 7.5% hydrogenated lard (HF) or 4.5% fatty acid ethyl ester (FEE). Compared to the controls, there were increases in the food intake in males and females of the SPE-groups, HF- group and FEE-group. Male rats fed SPE showed increases in serum urea nitrogen at all levels, in serum alkaline phosphatase activity and urinary glucose excretion at 10 and 15%, in serum leucine amino-peptidase at 15%. In females dietary SPE increased the blood glucose content and serum alkaline phosphatase activity at 15% and the serum leucine aminopeptidase activity at 10 and 15%.

Alkaline Phosphatase↗
PubMed1990

Biocompatibility of a polyether urethane, polypropylene oxide, and a polyether polyester copolymer. A qualitative and quantitative study of three alloplastic tympanic membrane materials in the rat middle ear.

The biocompatibility of porous implants made of Estane 5714 F1 polyether urethane, polypropylene oxide, and a poly(ethylene oxide hydantoin) and poly(tetramethylene terephthalate) segmented polyether polyester copolymer (HPOE/PBT copolymer), which were selected as candidates for an alloplastic tympanic membrane, was assessed after implantation in rat middle ears for periods of up to 1 year. Implantation of the materials led to tissue reactions initially associated with the wound-healing process, whereas after 1 month not only the presence of macrophages and foreign-body giant cells surrounding the implant materials but also implant degradation were characteristic for a foreign-body reaction. Macrophages and foreign-body giant cells dominated the picture of the tissue surrounding polypropylene oxide. The altered morphology of these cells, the persistent infiltration of the implantation sites by exudate cells, and the premature death of five rats in the 1-year group suggest that polypropylene oxide degradation was accompanied by the release of toxic substances. Estane and copolymer degradation did not induce tissue responses reflecting implant toxicity, and tympanic membranes given these alloplasts showed a normal healing pattern. Inclusions in the cytoplasm of macrophages associated with degradation and phagocytosis of all of the polymers under study were found to contain iron, silicon, titanium, and aluminum. Growth of fibrous tissue and bone, the latter into Estane and HPOE/PBT copolymer implants, indicated appropriate implant fixation by tissue, although macrophages and foreign-body giant cells were present as well. Especially the fixation of copolymer by ingrowth of bone seems promising in terms of the amount of bone in the pores and the electron-dense bone/copolymer interface. The latter is indicative for bonding osteogenesis. The HPOE/PBT copolymer is a better candidate for alloplastic tympanic membrane than Estane, and the use of polypropylene oxide cannot be recommended.

Animals↗