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Prevention of growth of Yersinia enterocolitica in blood by polyester fiber filtration.

The ability of polyester white cell-reduction blood filters to prevent the growth of Yersinia enterocolitica in units of donated blood was studied. Sixteen units of freshly drawn blood were inoculated with 10, 50, 100, or 150 colony-forming units (CFU) per mL of a clinical isolate of Y. enterocolitica (serotype O:3). The units were subsequently fractionated into red cell concentrate and resuspended in AS-1 or AS-3 solution. One-half of the red cell concentrates in each solution were filtered within 15 hours of phlebotomy and stored for 42 days. The remaining units served as unfiltered controls. Bacterial growth was monitored by weekly cultures and, on the last storage day, by the presence of endotoxin and the formation of methemoglobin. One hundred twelve primary cultures (560 plates) were performed. Units collected in AS-1 and filtered remained sterile when initially inoculated with 50 CFU or less. Filtered units spiked with 100 CFU or less and collected in AS-3 remained sterile throughout their shelf life. All unfiltered units supported bacterial growth and the formation of endotoxin and methemoglobin. The filtration of freshly donated blood proves to limit the growth of Y. enterocolitica in red cell components.

Blood Gas Analysis

Dibutyryl cAMP-inducible alkaline phosphatase in animal cell plasma membranes: fluorescence detection of mutant clones on polyester cloth.

We have developed a rapid screening assay that allows us to estimate the alkaline phosphatase content of mouse L-M cell colonies immobilized on polyester cloth. This permitted the identification and isolation of two mutant clones with increased constitutive alkaline phosphatase activity and six clones that fail to express this activity when treated with dibutyryl cyclic AMP. Both of the strains with increased constitutive activity have basal enzymatic activities that are 6- to 7-fold higher than the activity of the parental strain. The extents to which the cyclic nucleotide further induces alkaline phosphatase in these two strains are different, however, indicating that they represent two classes of mutants. Studies using amino acids and synthetic peptides as alkaline phosphatase inhibitors suggest that only one alkaline phosphatase isoenzyme predominates, in both the parental and the mutant cell lines, with or without induction by cyclic nucleotide. Comparison to mouse tissues indicates that our cell lines express an isozyme resembling that found in kidney and bone. The six clones that fail to express alkaline phosphatase activity when treated with dibutyryl cyclic AMP also have extremely low basal levels of the enzyme. All of these mutant strains continue to synthesize protein when treated with dibutyryl cyclic AMP and undergo growth cessation and morphological changes in the presence of this agent. Thus, the mutations all appear to affect factors specific to the expression of alkaline phosphatase activity rather than factors that affect general cellular responsiveness or permeability to dibutyryl cyclic AMP. The characterization of these strains may help elucidate mechanisms of eukaryotic membrane protein biogenesis, enzyme induction, and regulation of gene expression by cyclic nucleotides.

Alkaline Phosphatase

Sulfated polyester interactions with the CD4 molecule and with the third variable loop domain (v3) of gp120 are chemically distinct.

Sulfated polyesters (SP) that inhibit HIV infection interact with both the gp120 binding region of CD4 molecules and with the v3 domain loop of gp120 molecules (gp120/v3) but the contributions of these interactions to the inhibition of HIV env-mediated fusion are presently unclear. In order to characterize the molecular mechanisms by which SP inhibit HIV env-mediated fusion, we studied the effect of SP treatment on env-mediated fusion of CD4+ cells driven by recombinant vaccinia virus (vPE-16) and on the binding of anti-HIV MAbs to cellular gp120 or purified, rgp120. SP were more effective than neutralizing anti-gp120/v3 MAbs in inhibiting env-mediated fusion. In addition, SP interacted with the v3 loop of gp120 to inhibit the binding of the neutralizing MAb 9284 but not the binding of 9305, a neutralizing anti-gp120/v3 MAb that binds to an adjacent epitope. Because SP are polyanions, we compared the chemical properties of the SP-gp120/v3 and SP-CD4 interactions. Whereas the ability of SP to inhibit the binding of MAb 9284 and rgp120 was relatively independent of NaCl concentrations, the ability of SP to interfere with rCD4-rgp120 binding depended on the NaCl concentration and was maximal at low NaCl concentrations. In addition, the SP-gp120 interaction was found to be reversible, in contrast to the SP-rCD4 interaction which was previously shown to be relatively irreversible at low salt. These data are consistent with the notions that the interaction of SP with CD4 is primarily electrostatic, but that the interaction of SP with gp120 has complex characteristics that implicate a role for protein conformation.

Animals

The effect of a non-absorbable fat, sucrose polyester, on the metabolism of vitamin A by the rat.

Sucrose polyester (SPE) is a fat-like material that is not absorbed. The effect of this material on vitamin A metabolism was determined by measuring the amount of the vitamin that was stored in the liver of rats following the ingestion of a known amount of vitamin A. In one study, the vitamin A was administered as an oral dose in a vehicle consisting of various proportions of cottonseed oil and SPE. Each 1% replacement of cottonseed oil by SPE resulted in a 0.26% decrease in the amount of vitamin A found in the liver. In the second study, the vitamin A was incorporated into diets in which the fat component consisted of various proportions of cottonseed oil and SPE. When these diets were consumed for 1 week, each 1% replacement of cottonseed oil by SPE resulted in a 0.84% decrease in the storage of vitamin A by the liver. It is proposed that in the lumen of the intestine vitamin A distributes between the customary micellar phase and the unhydrolyzed oil phase of SPE. The vitamin A in this latter phase is eliminated in the feces.

Absorption

A modified technique (using polyester tape) of skin surface biopsy. Its interest for the investigation of athlete's foot.

A technical modification of skin surface biopsy has been introduced by using plastic tape instead of glass as holder, mainly to investigate mycological infections of skin folds. Among various brands of plastic sheets, a polyester film (Melinex O UCB-SIDAC) has been demonstrated as the most suitable. A direct microscopic comparison has been made between our modified technique and conventional scraping as procedures for collecting material from interdigital spaces in 30 patients with bilateral athlete's foot. It has been shown that the skin surface biopsy gives a slightly greater number of positive results (presence of dermatophytes or Candida species) than the conventional scraping technique, although the difference between both techniques is not statistically significant at the 0-05 level (0-05 less than P less than 0-10). Some advantages of the modified skin surface biopsy are emphasized.

Biopsy

Mortality of a cohort in a polyamide-polyester factory in Lyon: a further follow up.

In 1981-2 a retrospective study was undertaken in a polyamide-polyester factory in Lyon, France, to evaluate the effect of exposure to phthalates, nickel catalysers, and other chemicals in the work environment. The present paper reports the results of the follow up of this cohort up to July 1986. A slightly increased risk of cancers, in particular of the lung (44 cases), marginally related to exposure category but not significantly related to duration of exposure was found. The excess of skin cancers noted previously has disappeared, whereas an excess of cases of bladder cancer (based on seven cases) may be noted, mainly among nylon workers. The cohort is still young, however, and a continued follow up is likely to yield important information about the potential hazards associated with the nylon and tergal polymer industry.

Chemical Industry

Severe postural hypotension following home canoe construction from polyester resins.

On two occasions a 36-year-old man developed severe postural hypotension and neurological signs after working with a polyester resin canoe building kit in an unventilated shed. It is likely that his recurrent illness was caused by styrene intoxication. Postural hypotension secondary to styrene exposure has not previously been reported.

Hobbies

Polyester arterial grafts impregnated with cross-linked albumin: the rate of degradation of the coating in vivo.

One of the techniques used to avoid preclotting a porous textile arterial prosthesis is to coat the graft with a layer of a bioerodible polymer. The efficacy of this treatment is dependent in part on the rate at which the polymer degrades after implantation. The focus of this study was therefore to investigate the rate of in vivo degradation of albumin-coated polyester (Dacron)-knitted vascular prostheses. Two types of cross-linked albumin were included: one using glutaraldehyde, the other using carbodiimide as the cross-linking agent. Radioactively labeled albumin-coated prostheses were implanted in the thoracic aorta and peritoneal cavity of dogs, and their rates of biodegradation in vivo were monitored over a 4-week period. The rate of biodegradation was found to depend upon the site of implantation. It occurred more rapidly in the peritoneal cavity where less than 20% of the albumin coating remained after 4 weeks in vivo in comparison to the approximately 30% in the thoracic aorta. The nature and intensity of the cellular response appeared to be related to the cytotoxic potential of the cross-linking agent. Glutaraldehyde induced an inflammatory response and a delay in healing, whereas carbodiimide caused only a mild tissue reaction.

Animals

Characteristics of polyester arterial grafts coated with albumin: the role and importance of the cross-linking chemicals.

Preclotting is mandatory prior to implanting a knitted polyester arterial graft, unless the structure is made impermeable to blood by coating with a bioerodible material. Before achieving wide-spread clinical acceptance, the technique of impregnating with cross-linked albumin must be optimized in order to develop a graft that is immediately implantable, easy to handle and suture and has improved healing characteristics. The choice of the chemical to cross-link the albumin is of paramount importance. In this study two alternative candidates have been evaluated by using a series of tests to measure the physical properties, the morphology and the cytocompatibility of albumin-coated grafts. A carbodiimide cross-linking agent appears more promising than glutaraldehyde, since it is equally effective in producing a blood impermeable prosthesis, yet presents improved biocompatibility and provokes a less intense inflammatory response from the host.

Aldehydes

Aliphatic polyesters and cellulose-based polymers for controlled release applications.

The general technologies for fabricating drug delivery systems are briefly discussed in the present review. Furthermore, two types of commonly used polymers, biodegradable aliphatic polyesters for parenteral administration and cellulose-based polymers for oral uses, are presented by means of selected examples of their properties and applications to control drug release.

Cellulose

Strength of carbon and polyester fibre tendon replacements. Variation after operation in rabbits.

The calcaneal tendons of rabbits were excised and either replaced with a carbon or polyester fibre implant, or left as controls. The strength of the neotendons and their mode of failure under tension were examined at intervals up to six months after operation. Return to near normal strength took six months to develop, suggesting that patients having ligament or tendon reconstructions should not resume normal activity for several months. Carbon fibre-based neotendons showed progressive elongation which, unless avoided by a sufficient period of immobilisation, would affect the functional result.

Animals

Anterior cruciate ligament replacement with polyester fibre. A long-term study of tissue reactions and joint stability in sheep.

We excised the anterior cruciate ligament from the left stifle of 24 sheep and replaced it by a polyester fibre implant routed 'over the top' of the femoral condyle and fixed, using grommets and screws. All the joints were sound, and the animals moved normally until they were killed at six, 12 and 24 months after operation. We found that the implants were always covered by host tissue, which matured into bundles with a histological appearance similar to the natural ligament. The implants were joined to the bones by organised fibrous tissue and there was no anchorage loosening. There was no synovitis, but the operated joints showed progressive cartilage degeneration. The reconstructed joints became less stable immediately after operation, but regained normal stability as the neoligaments developed. The neoligaments lost strength with time, despite tissue ingrowth. The good functional, biomechanical, and histological results justify clinical trials of this type of implant.

Animals

Efficacy and safety of a polyester leukocyte removal filter for whole blood and red cell concentrate filtration.

Patients receiving multiple whole blood transfusions often experience adverse clinical symptoms caused by leukocytes. In the present study, the efficacy and safety of a polyester filter for leukocytes (Sepacell R-500) was evaluated. Donor units of whole blood and red cell concentrate stored for varying lengths of time were filtered. Emphasis was placed on humoral parameters indicative of release and/or activation reactions of granulocytes (neutral proteinase elastase, lysozyme, aggregation, chemiluminescence) and erythrocytes (lactate dehydrogenase, plasma haemoglobin). Nonspecific adsorption effects were investigated by plasma protein determinations (albumin, alpha 2-macroglobulin). A complete blood cell count as well as values of haemoglobin and haematocrit were determined. Sepacell R-500 proved to be a highly efficient filter to the leukocyte depletion of blood. Our results of erythrocyte and granulocyte related humoral parameters provided no significant evidence of filtration mediated activation or releasing reactions of clinical consequence.

Blood Preservation

Mortality experience in a polyamide-polyester factory.

Chemical workers have become increasingly concerned about the presence of carcinogens in their occupational environment. As a result, a number of studies of excess cancer mortality have been undertaken in groups of workers with well-characterized exposures. This paper reports the results of one such study carried out in a polyamide-polyester factory in France. A retrospective cohort design was chosen to evaluate the effect of exposure to phthalates, nickel catalyzers, and other chemicals in the work environment. Only a slight excess of cancers, marginally related to exposure category yet not significantly related to length of exposure, was found. The cohort, however, was young but stable, and a continued follow-up is therefore both feasible and justifiable, since it is likely to yield important information about the potential hazards associated with the tergal polymer industry.

Chemical Industry

Increased frequency of lymphocyte micronuclei in workers producing reinforced polyester resin with low exposure to styrene.

A new micronucleus method based on the analysis of lymphocytes with preserved cytoplasm revealed an increased frequency of micronuclei in 38 workers employed in a plant producing styrene-modified polyester resin as compared to the frequency in 20 referents (5.9 vs 3.6%). The time-weighted average of the styrene concentration in the workroom air varied between 1 and 36 ppm (mean 13 ppm) during the last year and correlated well to low urinary levels of mandelic acid, which ranged from 9 to 316 mg/g of creatinine (mean 65 mg/g of creatinine).

Adult

[Effect of leukocyte depleting polyester filters on thrombocytapheresis concentrates].

We studied platelet loss, leukocyte depletion, T/B cell ratio, platelet morphology and platelet function (aggregation, hypotonic shock reaction, retention and retraction) prior to and after filtration through two different polyester filters (Sepacell PL-5A, Pall PL100) as well as the posttransfusional platelet increment 1 h after transfusion in 8 pairs of single-donor platelet concentrates (Cobe Spectra, Fresenius AS 104). Leukocyte depletion was effective (>99.9%) and platelet loss acceptable in both filters, all tests showing no indication of a diminished platelet function by filtration.

Blood Component Transfusion

[Attempts at modification of the polyester vascular prosthesis].

Polyester vascular bilaterally velour prostheses produced by the Enterprise of Medical Products TRICOMED in Lodz were modified through: putting negative electric charge on the internal surfaces of prostheses; additional cleaning with ethanol; covering of the surfaces of prostheses with silicone preparation; two-sided covering of the surfaces of prostheses with collagen by the radiative method; covering of the surfaces of prostheses with chitosane. Laboratory investigations, investigations of hemolytic and toxic effects of aqueous as well as experimental investigations has been carried on piglets. During these investigations it was observed that the carried preparations caused multiple increase of electrical conductivity of proper and dry remnant after evaporation of the aqueous extracts. Hemolytic and toxic effects were not observed. In radiological and pathomorphological investigations it was observed that none of the preparations used for modification of vascular prostheses influenced improvement of their biological properties. In comparison with the initial prostheses DALLONR these prostheses evoked a greater reaction of tissues which was manifested with a thick internal layer causing narrowing of the lumen of the section with prosthesis or closing it. A small improvement of the biological properties of the prostheses were achieved after cleaning them with methanol. However, this improvement is so small that it does not justify changes in the existing technology.

Animals

Epidermabrasion for acne: the polyester fiber web sponge.

Physical-mechanical exfoliation with the nonwoven polyester fiber web sponge is an effective adjunct to the treatment of comedonal and pustular acne. Precisely controlled epidermabrasion is achieved by varying pressure, velocity, duration and frequency of use. Side effects are negligible and patient acceptance is high. Effectiveness is not dependent upon erythema and scaling since the web sponge mechanically removes keratin excrescences and trapped hairs in pilosebaceous ducts.

Acne Vulgaris