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At least 181 records · Page 10Linked to original sources

Polyethylene oxide additive-entrapped polyvinyl chloride as a new blood bag material.

Until now, most widely used blood bag material has been a plasticized polyvinyl chloride (PVC) because it has many desirable properties as a blood bag material. One of main concerns of using plasticized PVC as a blood bag material is the toxicity of the plasticizers that are leached out of the material. We tried to solve this problem by the addition of polyethylene oxide (PEO)-containing amphiphilic block copolymers as additives in the PVC. The PEO additives may play two roles: they can act as nontoxic plasticizers to PVC, and they can also act as blood-compatible surface modifiers. In this study, PEO additive-entrapped PVC films were prepared by the addition (up to 30 wt%) of PEO-alkyl carbon block copolymers or PEO-polypropylene oxide (PPO)-PEO triblock copolymers with different PEO chain lengths in the PVC. The prepared PEO additive-containing PVC films were characterized by the measurements of water contact angle, Fourier transform IR spectroscopy in the attenuated total reflectance mode, mechanical properties (tensile strength and elongation at break), water absorption, and stability of the PEO additives entrapped in the films. It was observed that the PEO additive-entrapped PVC films were flexible and transparent. It seems that the PEO additives are surface active, resulting in the considerable change of surface characteristics without a significant change of the mechanical properties of the films compared to the control PVC without any additives or a commercial blood bag. The adhesion of platelets on the film surfaces was significantly reduced by the addition of PEO additives. It seems that 10% addition of PEO additives is enough for the suppression of platelet adhesion on the surfaces. This study demonstrated that the use of PEO-containing block copolymers as additives to the PVC can be a feasible approach to prepare a new type of blood bag.

Biocompatible Materials↗

Determination by gas-liquid chromatography of trace amounts of soft polyvinyl chloride plastic additives in aqueous solutions. II. Di(2-ethylhexyl) phthalate, epoxidized vegetable oils and stearates.

A method for the determination of di(2-ethylhexyl) phthalate (DEHP), epoxidized vegetable oils (EVO) and stearates in aqueous solutions is described. A stepwise extraction procedure is employed to separate DEHP and EVO from the stearates, using n-hexane as extraction solvent. EVO is transesterified to methyl esters by sodium methoxide in methanol. The stearates are derivatized by methanol containing sulfuric acid. The alkyl esters are analyzed by gas-liquid chromatography, using 3% OV-210 as the stationary phase. The concentrations of the weakest standard solutions correspond to 10, 5 and 8 micrograms/l (ppb) of DEHP, EVO and stearates, respectively, in the aqueous samples. The method is used for the determination of DEHP, EVO and stearates in intravenous solutions stored in flexible polyvinyl chloride bags.

Chromatography, Gas↗

Pneumoconiosis and systemic sclerosis following 10 years of exposure to polyvinyl chloride dust.

The case history is presented of a 58 year old man who was exposed to thermoplastic dusts, mainly polyvinyl chloride (PVC), for 10 years. Radiography and high resolution computed tomographic scans of the lungs suggested both pneumoconiotic and scleroderma-like lesions. Transbronchial biopsy revealed foreign body granulomas with macrophages laden with birefringent inclusions which ultrastructurally resembled PVC dust. Biopsy samples of thickened skin showed histological evidence of extensive fibrosis. During follow up Raynaud's phenomenon and oesophageal involvement developed. The antinuclear antibody titre was 1:640, and the Sc1-70 subset was positive. It is concluded that exposure to PVC dust may cause pneumoconiosis and secondary systemic sclerosis.

Chemical Industry↗

A simple and reproducible testing method for dialkyl phthalate migration from polyvinyl chloride products into saliva simulant.

We describe a method of mechanical agitation to determine rates of dialkyl phthalate migration from polyvinyl chloride (PVC) products into saliva simulant. The method consists of rotary shaking of a sample with 30 mL of saliva simulant (pH 7.0) at 35 degrees C in a 50 mL glass tube at 300 rpm for 15 min, then measuring the amount of dialkyl phthalate in the saliva simulant by HPLC with a UV detector. The migration rates of diisononyl phthalate (DINP), di-2-ethylhexyl phthalate (DEHP) and di-n-butyl phthalate (DBP) from PVC plates containing about 45% (w/w) plasticizer (molded in our laboratory) were identical. However, the migration rates from molded plates containing 13% (w/w) DBP were almost double those of DINP and DEHP at the same ratios. In addition, the amounts of DINP that migrated in vitro after rotary shaking for 15 min were equivalent to those in vivo determined in saliva from volunteers who chewed plates for 60 min. The migration rates of dialkyl phthalates from 11 commercially available toys ranged from 15.6 to 85.2 micrograms/cm2/h [relative standard deviation (RSD), 3 to 12%].

Chromatography, High Pressure Liquid↗

Release behavior of diethylhexyl phthalate from the polyvinyl-chloride tubing used for intravenous administration and the plasticized PVC membrane.

The release behavior of diethylhexyl phthalate (DEHP) from polyvinyl-chloride (PVC) tubing, which composes materials in an intravenous administration set, was investigated using polysorbate 80 (Tween 80) aqueous solutions. When Tween 80 solution was circulated in PVC tubing, the amount of DEHP released increased with increasing circulation velocity and temperature. In order to clarify the effect of temperature on the release behavior of DEHP, PVC films containing varying amounts of DEHP were mounted on a cylindrical shaft and rotated at 5 and 40 degrees C. The cumulative amount of DEHP released increased with an increase in temperature, the diffusion coefficients [Dx10(-10) cm2 min-1] at 5 and 40 degrees C were 9.1 and 156.0, respectively. The glass transition temperature (Tg) of PVC films decreased with an increase in DEHP in the PVC film, as measured by differential scanning calorimeter (DSC) and release of DEHP occurred at temperatures above Tg. These results indicate that the release of DEHP from PVC tubing is closely associated with the state of the PVC and is related to diffusion of DEHP throughout the PVC.

Algorithms↗

The role of metals in dioxin formation from combustion of newspapers and polyvinyl chloride in an incinerator.

Newspapers impregnated with NaCl mixed with various chloride metals (CuCl2, MgCl2, MnCl2, FeCl3, NiCl2, and CoCl2) and electric wire coated with polyvinyl chloride (PVC) were combusted in a well-controlled incinerator. Exhaust gas samples collected at the outlet of the incinerator were analyzed for dioxins (PCDDs, PCDFs, and coplanar PCBs) by gas chromatography/mass spectrometry. The amount of total dioxins formed from newspaper samples ranged from 34.2 ng/g (with NaCl+CoCl2) to 67.0 ng/g (with NaCl+CuCl2). PCDFs composed 88-94% of the total dioxins formed in the exhaust gases. The highest levels of PCDF isomers obtained were Cl3-CDF from the sample with NaCl+CuCl2 (14.8 ng/g), Cl2-CDF from the sample with NaCl+MgCl2 (12.3 ng/g), and Cl(1)-CDF from samples with NaCl+MnCl2 (12.6 ng/g), with NaCl+FeCl3 (11.8 ng/g), and with NaCl+NiCl2 (13.3 ng/g), and with NaCl+CoCl2 (8.62 ng/g). The total of Cl4-8-CDDs comprised 76-88% of the total Cl1-8-CDDs. In particular, Cl7-CDDs had the highest levels except for the sample with NaCl+NiCl2. Total dioxins formed from samples of electric wire coated with PVC and PVC alone were 38.3 ng/g and 112 ng/g, respectively, suggesting that the presence of copper reduced dioxin formation.

Dioxins↗

Inflammatory response of rat and human neutrophils exposed to di-(2-ethyl-hexyl)-phthalate-plasticized polyvinyl chloride.

A series of in vitro studies were designed to determine whether di-(2-ethyl-hexyl)-phthalate (DEHP)-plasticized polyvinyl chloride (PVC) and DEHP itself initiated an inflammatory response in both human and rat blood. Additionally, the effect of methanol washing of the PVC on the inflammatory response was studied in both blood types. Blood from both species was exposed to first, no material; second, ground DEHP-plasticized PVC; third, methanol-washed ground DEHP-plasticized PVC; and fourth, known concentrations of DEHP. The expression of the integrin CD11b was employed as a marker of the inflammatory response. After 20 minutes' exposure to PVC, CD11b expression increased to 210 +/- 32% of baseline in human blood and to 238 +/- 21.7% in rodent blood. Both blood types showed an increase in CD11b expression with increasing concentrations of DEHP (214 +/- 40.8% of baseline levels in human blood and 237 +/- 14.5% in rodent blood at the highest concentration). Methanol washing resulted in a significant moderation in CD11b upregulation in both blood types; 117 +/- 27% of baseline in human and 150 +/- 14.7% in rodent. These results support the hypothesis that DEHP-plasticized PVC and DEHP itself are proinflammatory in blood from both species, and suggest that the rodent is an appropriate model for studies of this nature.

Animals↗

Staphylococcal adherence to polyvinyl chloride and heparin-bonded polyurethane catheters is species dependent and enhanced by fibronectin.

Intravenous hyperalimentation has improved the survival of premature infants. However, long-term placement of intravenous catheters may result in the development of catheter-related sepsis. Fibronectin in plasma contains binding sites for staphylococcal species as well as marked affinity for inert plastics and therefore may provide a substrate for bacterial adherence to indwelling catheters. We determined the adherence of labeled [( 3H]leucine) coagulase-positive (CPS) and coagulase-negative (CNS) staphylococci to untreated and fibronectin-coated polyvinyl chloride (PVC) and heparin-bonded polyurethane (HBP) catheter segments and quantitated the binding of 14C-labeled, purified fibronectin to these catheters. PVC catheter segments bound significantly more CNS than CPS (P less than 0.05), while HBP catheters bound more CPS than CNS (P less than 0.05). Fibronectin significantly increased the adherence of CPS to PVC catheters (P less than 0.05) and CNS to HBP catheters (P less than 0.05). PVC catheters bound more fibronectin (P less than 0.0001) than did HBP catheters. Catheter composition may influence the spectrum of nosocomial pathogens to which infants are susceptible through different bacterial adherences and interactions with adhesive proteins.

Bacterial Adhesion↗

Friction loss in straight pipes of unplasticized polyvinyl chloride.

In order to design proper ductwork for a local exhaust system, airflow characteristics were investigated in straight pipes of unplasticized polyvinyl chloride (PVC). A linear decrease in static pressure was observed downstream at points from the opening of the VU pipes (JIS K 6741) located at distances greater than 10 times the pipe diameter, for velocities ranging between 10.18-36.91 m/s. Roughness inside pipes with small diameters was found to be 0.0042-0.0056 mm and the friction factor was calculated on the basis of Colebrook's equation for an airflow transition zone. An extended friction chart was then constructed on the basis of the roughness value and the friction factor. This chart can be applied when designing a local exhaust system with the ducts of diameters ranging from 40 to 900 mm. The friction loss of the PVC pipe was found to be approximately 2/3 of that of a galvanized steel pipe.

Equipment Design↗

Inhibition of membrane Na(+)-K+ Atpase of the brain, liver and RBC in rats administered di(2-ethyl hexyl) phthalate (DEHP) a plasticizer used in polyvinyl chloride (PVC) blood storage bags.

Significant amounts of di(2-ethylhexyl) phthalate (DEHP) leach out into blood stored in DEHP plasticized polyvinyl chloride (PVC) bags resulting in the exposure of recipients of blood transfusion to this compound. The aim of this study was to find out whether DEHP at these low levels has any effect on the activity of membrane Na(+)-K+ ATPase, since a decrease in this enzyme activity has been reported to take place in a number of disorders like neurodegenerative and psychiatric disorders, coronary artery disease and stroke, syndrome-X, tumours etc. DEHP was administered (ip) at a low dose of 750 microg/100 g body weight to rats and the activity of membrane Na(+)-K+ ATPase in liver, brain and RBC was estimated. Histopathology of brain, activity of HMG CoA reductase (a major rate limiting enzyme in the isoprenoid pathway of which digoxin, the physiological inhibitor of Na(+)-K+ ATPase is a product), intracellular concentration of Ca2+ and Mg2+ in RBC (which is altered as a result of inhibition of Na(+)-K+ ATPase) were also studied. (In the light of the observation of increase of intracellular Ca2+ load and intracellular depletion of Mg2+ when Na(+)-K+ ATPase is inhibited). Histopathology of brain revealed areas of degeneration in the rats administered DEHP. There was significant inhibition of membrane Na(+)-K+ ATPase in brain, liver and RBC. Intracellular Ca2+ increased in the RBC while intracellular Mg2+ decreased. However activity of hepatic HMG CoA reductase decreased. Activity of Na(+)-K+ ATPase and HMG CoA reductase, however returned to normal levels within 7 days of stopping administration of DEHP. The inhibition of membrane Na(+)-K+ ATPase activity by DEHP may indicate the possibility of predisposing recipients of transfusion of blood or hemodialysis to the various disorders mentioned above. However since this effect is reversed when DEHP administration is stopped, it may not be a serious problem in the case of a few transfusion; but in patients receiving repeated blood transfusion as in thalassemia patients or patients undergoing hemodialysis, possibility of this risk has to be considered. This inhibition is a direct effect of DEHP or its metabolites, since activity of HMG CoA reductase, (an enzyme which catalyses a major rate limiting step in the isoprenoid pathway by which digoxin, the physiological inhibitor of Na(+)-K+ ATPase is synthesized) showed a decrease.

Animals↗

Nitroglycerin adsorption to a combination polyvinyl chloride, polyethylene intravenous administration set.

Loss of nitroglycerin (NTG) from intravenous solutions to intravenous bags and administration sets has been well documented. This study was designed to examine a commercially available low adsorption administration set that was compatible with a volumetric infusion pump. A solution of NTG 100 micrograms/ml in dextrose 5% in glass bottles was used. Six study administration sets were tested. The infusion sets were connected to the NTG-containing glass bottles, filled as rapidly as possible, placed in the infusion pump, and set at the appropriate rate. Effluent was collected for NTG assay initially, and at 20 and 40 minutes, and 1, 1.5, 2, 3, 6, and 24 hours. The effects of flow rate were studied at 0.2 and 1.0 ml/min. The tubing performed similarly to other polyvinyl chloride (PVC)-containing sets at 0.2 ml/min and similar to non-PVC sets at 1.0 ml/min. The effect of an initial flush with 20-100 ml of 100 micrograms/ml NTG was also examined. An initial flush of 20 ml of 100 micrograms/ml NTG solution was found to enhance delivery of NTG immediately. NTG aliquots were stored frozen in glass vials prior to assay by high performance liquid chromatography.

Adsorption↗

Gas chromatography-mass spectrometry determination of the migration of phthalate plasticisers from polyvinyl chloride toys and childcare articles.

Two laboratory-based linear horizontal agitation methods for determining a range of phthalate esters from soft polyvinyl chloride (PVC) toys are presented in compliance with EU legislation. Both of these methods were validated through interlaboratory trials using a PVC reference disc and four soft PVC toy/childcare articles intended or likely to be mouthed. Two of these commercial samples contained diisononyl phthalate (DINP), one diisodecyl phthalate (DIDP) and one bis(2-ethylhexyl) phthalate (DEHP). Acceptable repeatability (r, within-laboratory) and reproducibility (R, between-laboratory) data were demonstrated for both the analytical detection technique (GC-MS) (r = 9.8% and R = 8.1%) and agitation/extraction procedure (r=21.9% and R = 35.3% at 37 degrees C; r = 22.7% and R = 31.1% at 65 degrees C) for DINP. This was achieved through the participation of six laboratories. The remaining three phthalates from the EU Scientific Committee for Toxicity, Ecotoxicity and the Environment (CSTEE) list--dibutyl phthalate (DBP), benzyl butyl phthalate (BBP) and di-n-octyl phthalate (DnOP)--were not tested due to the unavailability of suitable materials.

Gas Chromatography-Mass Spectrometry↗

Comparison of polyvinyl chloride membrane electrodes sensitive to alkylphosphonium ions for the determination of the electrical difference (delta psi) of Streptococcus mutans and Lactobacillus casei.

Polyvinyl chloride membrane electrodes sensitive to tetraphenyl phosphonium (TPP+), butyltriphenyl phosphonium ( bTPP +), and methyltriphenyl phosphonium ( mTPP +) ions have been compared for the determination of the electrical potential difference (delta psi) of the oral bacteria, Streptococcus mutans DR0001 /6 and Lactobacillus casei RB1014 . All three types of electrode proved suitable for determining delta psi, although the TPP+-sensitive electrode was particularly susceptible to interference by protonmotive force (delta p) dissipators known to inhibit sugar uptake by the bacteria. The mTPP +-sensitive electrode was the least affected. Similarly, both strains had a high nonspecific binding capacity for TPP+ and bTPP + ions, and this increased for all three ions when the bacteria were heated to 80 degrees C for 1 h to abolish glucose uptake and metabolism. This heat-treatment procedure is therefore not a suitable control for determination of nonspecific binding to cells. However, 1% (v/v) toluene, 20 microM gramicidin, or 10 microM valinomycin effectively depolarized the bacteria without interfering with nonspecific binding. The ionophores were therefore used subsequently for the determination of nonspecific binding of the lipid-soluble cations. The mTPP + ion and corresponding electrode proved the most effective system, and delta psi values of -89 and -107 mV were obtained for S. mutans and L. casei, respectively, harvested from glucose-limited continuous cultures and incubated in 100 mM Hepes-KOH buffer (pH 7.0), containing 1 mM dithiothreitol and 10 mM glucose. Although the delta psi of S. mutans decreased significantly in the presence of Mes-KOH and potassium phosphate buffers at pH 7.0, it increased to -119 mV in Tris-HCl buffer (pH 7.0).(ABSTRACT TRUNCATED AT 250 WORDS)

Biological Transport, Active↗

A comparative study of platelets stored in polyvinyl chloride containers plasticised with butyryl trihexyl citrate or triethylhexyl trimellitate.

Platelet concentrates (PCs), stored for 5 days in PL 2209, a new polyvinyl chloride (PVC) storage container plasticised with butyryl trihexyl citrate, were compared with those stored in PL 1240, a PVC platelet container plasticised with triethylhexyl trimellitate. In part 1 of the study, pooled platelet-rich plasma (PRP) was aliquoted into each type of pack and pH, pCO2, pO2, hypotonic shock response, aggregation responses, lactate, glucose and ATP concentrations, and lactate dehydrogenase and beta-thromboglobulin release were compared at days 1, 3 and 5. In part 2, 12 volunteers gave a unit of blood on two separate occasions and PCs produced by the PRP method were stored in PL 2209 or PL 1240 for 5 days before autologous reinfusion of a 111In-labelled sample. In vitro results demonstrated that PL 2209 was more gas permeable than PL 1240. In part 2 of the study, at day 5, pCO2 was 3.13 +/- 0.62 versus 5.14 +/- 0.69 (p < 0.001), whilst pO2 was not significantly different for PL 2209 versus PL 1240, respectively. pH was better maintained in PL 2209 than in PL 1240 (7.38 +/- 0.13 vs. 7.24 +/- 0.10, respectively, p < 0.01) after storage for 5 days. These results were confirmed by those from part 1. In vivo data were similar for PC stored in the two plastics with a multiple-hit recovery of 40.9 +/- 12.1% for PL 2209 and 37.4 +/- 11.3% for PL 1240, and a multiple-hit survival of 4.89 +/- 1.20 days and 5.28 +/- 2.06 days for PL 2209 and PL 1240, respectively. gamma-Camera imaging of volunteers showed similar biodistribution of radiolabelled platelets stored in each container. These results demonstrate that PL 2209 is a suitable container for storage of PCs for 5 days.

Benzoates↗

Leaching of diethylhexyl phthalate from polyvinyl chloride materials into etoposide intravenous solutions.

Etoposide intravenous solution is associated with leaching of diethylhexyl phthalate (DEHP) from bags and tubings made from polyvinyl chloride (PVC). Recent evidence suggests that this may be more substantial than previously found. Since DEHP is potentially hepatotoxic and carcinogenic, it is preferable to prepare and administer etoposide bags and tubings made from non-PVC materials.

Antineoplastic Agents, Phytogenic↗

Lost bits: particle shedding with polyvinyl chloride intravenous administration sets.

Silicone particles have been demonstrated in the effluent from silicone intravenous (IV) tubing. It has been widely suspected that polyvinyl chloride (PVC) particles are also lost. We sought to clarify the situation in a carefully controlled laboratory setting using the apparatus and flow rates common in a paediatric setting, using scanning electron microscope techniques (SEM), we found that particles were indeed shed from IV tubing during use, but they were not PVC.

Equipment Contamination↗