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PubMed2001

[The amount of the loss of cyclosporine A dose correlated with the amount of leaching di (2-ethylhexyl) phthalate from polyvinyl chloride infusion tube].

An interaction between cyclosporine A (CyA) injection and infusion tubes were examined. We used polyvinyl chloride (PVC) and polybutadiene (PB) tubes. CyA injection (Sandimmun) was diluted (0.495 mg CyA/ml) with saline and dripped through infusion tubes. The amounts of unsolved substances, loss of CyA dose and leached di (2-ethylhexyl) phthalate (DEHP) during the drip study were compared. CyA was not lost into the PB tube and no DEHP was leached. Therefore, using PVC tube, 11.9 mg of CyA were lost with in 24 h after the beginning of the administration, and the concentration of leached DEHP amounted to 93.6 micrograms/ml at 12 h. We also investigated the effects of the component of the einfusion solution on the loss of CyA into PVC tube using saline, electrolyte maintenance solution, 5% glucose and 10% maltose. Sugar-containing solutions were found to have less effects than other solutions on the loss of CyA dose and DEHP leaching. The leaching of DEHP may be a major factor for the generation of unsolved substances and the loss of CyA dose. In the clinical use of CyA injection, PB tube is the best selection and the sugar-containing solution is a second selection when PB infusion tubes are hard to obtain.

Adsorption↗
PubMedDate not supplied

Coimmobilization of urease and glutamate dehydrogenase in electrochemically prepared polypyrrole-polyvinyl sulfonate films.

Immobilization of urease and glutamate dehydrogenase enzymes in electrochemically prepared polypyrrole-polyvinyl sulfonate films (PPY-PVS) was carried out using physical adsorption and electrochemical entrapment techniques. Detailed studies on optimum pH, Fourier transform infrared spectroscopy, cyclic voltammetry, and scanning electron microscopy of the enzymes in the immobilized state were conducted. The value of the apparent Michaelis-Menten constant was experimentally determined to be 2.5 and 2.7 for physically adsorbed and electrochemically entrapped urease in PPY-PVS films, respectively.

Biosensing Techniques↗
PubMedDate not supplied

Characterization of DNA immobilized on electrochemically prepared conducting polypyrrole-polyvinyl sulfonate films.

The article describes the adsorption characteristics of DNA onto electrochemically generated polypyrrole-polyvinyl sulfonate (PPY-PVS) films obtained as a function of pH. Adsorption on PPY doped with an anion proceeds by anion exchange, and since DNA possesses a fixed negative charge owing to PO4-, it favors a very strong binding displacing PVS with favorable energetic interactions. Characterization of adsorbed DNA onto the PPY-PVS films was carried out by ultraviolet-visible, Fourier transform infrared spectroscopy, and cyclic voltammetric studies.

Adsorption↗
PubMed2004

Percutaneous transluminal septal artery ablation using polyvinyl alcohol foam particles for septal hypertrophy in patients with hypertrophic obstructive cardiomyopathy: acute and 3-year outcomes.

PURPOSE: To investigate the effect of septal artery occlusion with transluminally delivered polyvinyl alcohol (PVA) foam particles for the treatment of hypertrophic obstructive cardiomyopathy (HOCM). METHODS: Percutaneous septal artery ablation was performed in 18 symptomatic patients (13 men; mean age 60+/-17 years, range 28-89) with drug-resistant HOCM. PVA foam particles were mixed with contrast medium and injected through an angiographic catheter under fluoroscopic control until complete stasis in the septal branch was achieved. Patients were monitored with echocardiography and cardiovascular magnetic resonance imaging. RESULTS: The septal artery was successfully occluded in all patients; no embolization of other coronary branches occurred after infusion of 3 to 8 mL (5.2+/-0.8) of PVA foam particles. The resting pressure gradient was diminished from 83+/-32 to 31+/-35 mmHg (p<0.05). Over a mean follow-up of 44+/-4 months, all patients had symptomatic improvement of their dyspnea and workload without the need for intensified drug therapy. The average NYHA functional class decreased from 3.3+/-0.5 to 1.3+/-0.7 (p<0.0001), with a significant increase in the area of the left ventricular outflow tract (1.3+/-0.2 to 2.6+/-0.2 cm2, p<0.0001). Three instances of transient atrioventricular block occurred, but no complete heart block was produced by the embolization procedure. CONCLUSIONS: Embolization of the septal artery with PVA foam particles appears effective and safe in this series of patients with hypertrophic obstructive cardiomyopathy. The pure ischemic infarction produced by PVA ablation might be the responsible for the lack of complete heart block and the need for permanent pacing.

Adult↗
PubMedDate not supplied

Polyvinyl alcohol-glutaraldehyde as solid-phase in ELISA for schistosomiasis.

Soluble adult Schistosoma mansoni antigen preparation (SWAP) was covalently fixed onto polyvinyl alcohol-glutaraldehyde discs and an enzyme linked-immunosorbent assay (ELISA) was set up. The best conditions for the assay were established and it was found that small amount of antigen such as 1.5 micrograms was required. A comparison between this procedure and the conventional ELISA was proceeded. A reliable method of antigen immobilization was achieved and the low prices of the employed reagents are economically attractive.

Animals↗
PubMedDate not supplied

The use of polyvinyl alcohol glutaraldehyde as solid-phase in ELISA for plague.

Discs of polyvinyl alcohol cross-linked with glutaraldehyde were synthesized under acid catalysis (H2SO4). Then, the antigen F1 purified from Yersinia pestis was covalently linked to this modified polymer. Afterwards, an enzyme-linked immunosorbent assay (ELISA) was established for the diagnosis of plague in rabbit and human. The best conditions for the method were achieved by using 1.3 micrograms of F1 prepared in 0.067 M phosphate buffer, pH 7.2, containing 1 M NaCl (PBS); anti-IgG peroxidase conjugate diluted 6,000 times and as a blocking agent 3% w/v skim milk in PBS. The titration of positive rabbit serum according to this procedure detected antibody concentrations up to 1:12,800 times. The present method, the conventional ELISA and passive haemagglutination assay are compared.

Animals↗
PubMed2001

Polyvinyl alcohol as a useful indicator on iodometry: volumetric and spectrophotometric studies on iodine-PVA and iodine-starch complexes.

Iodometry is one of the easiest, most rapid and accurate methods for the determination of a relatively small amount of oxidizing agent, such as residual chlorine. Starch has long been used as a useful color indicator in iodometry. However, we found that PVA (polyvinyl alcohol with partially saponificated; e.g., saponification degree of 88%) is a more useful color indicator than starch. For example, at 20 degrees C, the PVA indicator gave similar profiles of iodine concentration vs. titration efficiencies (percent recoveries) to those of starch at 0 degrees C. At 0 degrees C, the PVA indicator detected 1.1 mg I2/L (11 microg I2: with 10 mL sample volume) with a high percentage of recovery (=95%). Furthermore, at 20 degrees C an iodine concentration of 0.36 mg/L (which corresponds to a residual chlorine concentration of 0.1 mg Cl2/L) could be detected using PVA color indicator assuming an appropriate correction.

Chlorine↗
PubMed2005

Safety and efficacy of preoperative portal vein embolization with polyvinyl alcohol in 58 patients with liver metastases.

OBJECTIVE: The objective of our study was to evaluate the safety and efficacy of transhepatic lobar portal vein embolization (PVE) using polyvinyl alcohol (PVA) particles to induce contralateral lobar hypertrophy in patients with liver-only metastases and normal underlying liver function. MATERIALS AND METHODS: Fifty-eight consecutive patients with small predicted future liver remnants (FLRs) underwent PVE with PVA particles to induce hypertrophy of the contralateral hemi-liver before surgical resection of liver metastases. Total liver, right hemi-liver, and left hemi-liver volumes were calculated before and after embolization using a 3D workstation. RESULTS: Eight patients underwent left PVE; 47, right PVE; and three, right and segment IV PVE. There were no major complications of the procedure. The mean increases in the ratio of the FLR to the total estimated liver volume after right, right and segment IV, and left PVE were 9%, 10%, and 3%, respectively; the corresponding mean hypertrophy ratios were 24.3%, 31.9%, and 1.5%, respectively. CONCLUSION: Right PVE using PVA particles alone as the embolic agent is safe and effective in achieving left hemi-liver hypertrophy. In contrast, left PVE did not induce significant right hemi-liver hypertrophy in this patient population.

Adult↗
PubMed1996

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↗
PubMed1996

Pressure loss in elbow pipes of unplasticized polyvinyl chloride.

In the ductwork of local exhaust systems, 90 degrees elbow pipes (JIS K 6739) are commonly used to alter the direction of airflow; thus, are important components of polyvinyl chloride (PVC) ducts. Pressure loss in 90 degrees PVC elbow pipes was investigated by measuring static pressure, and the characteristics of airflow was determined. First, a linear decrease in static pressure was observed at points of the downstream side beyond a distance of 10 times the diameter (10d) from the flanged round opening of the smooth VU ducts (JIS K6741). The linear decrease was also observed at points of the downstream side located at distances of greater than 30d from the elbow pipe. Coefficients of loss in the PVC elbow pipes were found to be constant for the Reynolds numbers ranging from 3.38 x 10(4) to 5.96 x 10(5) for all diameters examined, and a chart of pressure loss was constructed with these coefficients. The coefficients of loss in PVC elbow pipes were not equivalent to those of metal stamped elbows for any R/d. However, the differences in the coefficients between the metal stamped elbow and the PVC elbow were smaller with larger R/d values.

Equipment Design↗
PubMed2006

Effects of polyvinyl chloride overwrap film, high-oxygen modified atmosphere packaging, or ultra-low-oxygen modified atmosphere packaging on bone marrow discoloration in beef humerus, rib, thoracic vertebra, and scapula.

Meat retailers have reported bone marrow discoloration to be a problem, especially in modified atmosphere packages (MAP). Therefore, it is important to determine the prevalence and cause(s) of bone marrow discoloration in different beef bones and packaging systems. Thirty-six beef humeri, ribs, scapulas, and thoracic vertebrae from USDA Select and Choice carcasses were obtained from a commercial abattoir, cut into 2.54-cm-thick sections at 4 d postmortem, and packaged into 1 of 3 systems: 1) polyvinyl chloride film (PVC) overwrap; 2) high-oxygen (80% O2, 20% CO2) MAP; and 3) ultra-low-oxygen (70% N2, 30% CO2) MAP. Instrumental reflectance and visual color scores were taken on d 0, 2, and 4, and on d 0 to 4 of display, respectively. Bone marrow was extracted from humeri, ribs, and thoracic vertebrae for analysis but not from scapulas. Ribs, scapulas, and thoracic vertebrae packaged in PVC and high-oxygen MAP developed undesirable gray or black discoloration. In ultra-low-oxygen MAP, mean visual color scores were acceptable throughout the entire display period. Discoloration (darkening) was more extensive for ribs, scapulas, and thoracic vertebrae than for humeri, especially for bones packaged in PVC and high-oxygen MAP. Humeri had lower (P < 0.05) a* values (larger positive a* values indicate a redder color) than the other bones. The a* values for ribs, scapulas, and thoracic vertebrae decreased (P < 0.05) over time. Chroma showed that bone marrow discolored during display, but graying was dramatically less for all bones packaged in ultra-low-oxygen MAP and for humeri in PVC and high-oxygen MAP. Humeri marrow had lower (P < 0.05) 2-thiobarbituric acid reactive substances (TBARS) than did ribs and thoracic vertebrae marrow. Ultra-low-oxygen MAP resulted in the least amount of change in TBARS from d 0 to 4, whereas thoracic vertebrae marrow had greater (P < 0.05) TBARS values at d 4 of display than at d 0 in PVC and high-oxygen MAP. Humeri marrow had dramatically less total Fe and hemoglobin than did that of ribs and thoracic vertebrae for all packaging systems. Myoglobin was undetectable in humeri marrow. The much larger amounts of Fe and hemoglobin in ribs and thoracic vertebrae likely contribute to marrow discoloration. Bone marrow discoloration was distinct in ribs, scapulas, and thoracic vertebrae packaged in PVC or high-oxygen MAP. Bones packaged in ultra-low-oxygen MAP had minimal discoloration.

Animals↗
PubMed1975

The need for modification of the polyvinyl sponge model of connective tissue growth. Histoligic and biochemical studies in the rabbit.

Quantitative histopathologic and biochemical comparisons were made between polyvinyl sponge capsular and sponge tissue in the rabbit on different days after subcutaneous implantation. Up to 9 days the predominant cell type in the capsular tissue is the fibroblast and in the sponge it is the neutrophil. During this time period the sponge tissue shows lower rates of (14C) proline and (14C) cytidine incorporation and lower rates of total (14C) collagen synthesis than the surrounding capsule. Different gel electrophoretic patterns of isolated radioactive proteins are found in sponge and capsule at 6 days. These biochemical differences appear to be related to the small number of fibroblasts, relative to granulocytes present in sponges during the first 9 days after implantation. It is suggested that future biochemical investigations of the early phase of connective tissue reactions (first 9 days) in this model utilize sponge capsular tissue within 1 cm of the sponge edge instead of the sponge and its contents.

Animals↗
PubMed1995

Stability of polypeptide immunoreactants and polyvinyl alcohol as a blocking agent on polyester cloth during dry storage.

During dry storage at 32 degrees C for 70 days, polypeptide immunoreactants (rabbit IgG and rabbit antiperoxidase antibody) adsorbed onto polyester cloth demonstrated no loss of immunoreactivity. Polyvinyl alcohol of molecular weight 30,000-70,000 provided a stable blocking capacity on the immunoreactant-adsorbed cloth without affecting immunoreactivity. Cloth-based enzyme immunoassay systems are suitable for field testing and transportation in the absence of refrigeration.

Adsorption↗
PubMed1993

Evaluation of PDGF-BB, PDGF-AA, bFGF, IL-1, and EGF dose responses in polyvinyl alcohol sponge implants assessed by a rapid histologic method.

Polyvinyl alcohol sponge implants were used in rats, mice, and guinea pigs to determine dose responses of growth factors. Eight differently treated sponges per rat or guinea pig (4/mouse) were injected with test material on alternate days and evaluated at day 8. Much of the observed response occurred in and around the capsule and was manifest as densely cellular granulation tissue. Including this capsular response in a single histologic slide ranking system provided a more sensitive and faster method of assessing growth factor effects than measurement of connective tissue ingrowth alone. Clear dose responsive effects were seen with recombinant human PDGF-BB, PDGF-AA, bFGF, and IL-1 beta, while EGF gave a lesser response. Lipopolysaccharide did not affect the connective tissue response, alone or in combination with PDGF-BB. PDGF-BB was tested in each species, and the dose response characteristics were qualitatively and quantitatively similar across species.

Animals↗
PubMed1998

Peroral administration of 14C-poly(D,L-lactic acid) nanoparticles coated with human serum albumin or polyvinyl alcohol to guinea pigs.

Biodegradable 14C-poly(D,L-lactic acid) (PLA50) nanoparticles coated either with a readily digestible protein albumin or with a non-digestible coating agent, polyvinyl alcohol (PVA), were prepared by the solvent evaporation technique. The nanoparticles were administered perorally to guinea pigs to evaluate the gastro-intestinal degradation of their PLA50 matrix. In the case of PLA50 nanoparticles coated with digestible albumin, substantial gastro-intestinal degradation of the PLA50 matrix occurred, leading to the passage of considerable amount (> or =45%) of water-soluble products across the gastrointestinal barrier. When a non-digestible coating agent like PVA was used, the degradation of the PLA50 matrix in the gastro-intestinal tract was at least two times lower (> or =19%). The results show that it is possible to control the in vivo degradation of PLA50 nanoparticles using appropriate coating agents. The present investigations showed a good correlation between previously observed in vitro results and the in vivo findings.

Animals↗
PubMedDate not supplied

Experimental application of polyvinyl alcohol-silica for small artificial vessels.

Polyvinyl alcohol-silica (PVA-SiO2) composite and heparinized PVA-SiO2 were examined in vitro and in vivo as materials to coat artificial vessels to be used for the replacement of small arteries. PVA-SiO2 was observed to prolong coagulation time and on heparinized PVA-SiO2 surfaces no blood coagulation was noticed after a period of two days using the Lee-White and plasma recalcification methods. After placing non-coated and coated surfaces in contact with blood components in vitro and in vivo, the degree of blood component adhesion was greater in non-coated woven Dacron than in PVA-SiO2 coated Dacron. The degree of adhesion was even less in heparinized PVA-SiO2 coated Dacron. Furthermore, artificial vessels made of these 3 types of materials were used to replace parts of the canine abdominal aorta and were removed one and a half years later. Patency rates were as follows: non-coated 2/7, PVA-SiO2-coated 4/7, heparinized PVA-SiO2-coated 8/12. The inner surfaces of these prostheses were observed with light microscopy and scanning electron microscopy. Intima formation was thinner on the PVA-SiO2 composite surfaces than on the control surfaces. Heparin acted as a local anticoagulant and PVA-SiO2 limited intima formation. This report showed that PVA-SiO2 composite coated surfaces can be effective for small artery replacement due to good tissue affinity and anticoagulability.

Animals↗
PubMed2000

Migration of di-(2-ethylhexylexyl)adipate plasticizer from food-grade polyvinyl chloride film into hard and soft cheeses.

Food-grade polyvinyl chloride (PVC) film containing 28.3% di-(2-ethylhexylexyl)adipate (DEHA) plasticizer was used to wrap three different types of cheese (Kefalotyri, Edam, and Feta). Samples were split into two groups and stored at 5+/-0.5 degrees C. One group was analyzed for DEHA content at intervals between 1 and 240 h of contact (kinetic study), and a second group was cut into slices (1.2 mm thick) after 240 h of cheese/PVC contact and was analyzed for DEHA content (penetration study). The DEHA was determined by indirect gas chromatography. Statistically significant differences in migration of DEHA were observed between the cheese types. Migration of DEHA depended on contact time, fat, and moisture contents, and consistency of cheese samples. Equilibrium conditions were approached after approximately 100 h of contact for Edam and 150 h for Kefalotyri cheese. Equilibrium conditions were not reached for Feta cheese, even after 240 h of contact. After 240 h of contact under refrigeration, the migration of DEHA was approximately 345.4 mg/kg (18.9 mg/dm2) for Kefalotyri, 222.5 mg/kg (12.2 mg/dm2) for Edam, and 133.9 mg/kg (7.3 mg/dm2) for Feta. The loss of DEHA from the PVC film into the three cheese types was 37.8, 24.3, and 14.6%, respectively. These values, with the exception of Feta, were higher than the upper limit for global migration from plastic packaging materials into food and food stimulants set by the European Union (EU) (10 mg/dm2 or 60 mg/kg). After 240 h of cheese/film contact, DEHA was detected in the first three slices beneath the cheese surface (3.6 mm total depth) of Edam cheese and in the first two slices (2.4 mm total depth) of Kefalotryi and Feta cheeses. DEHA was not detected in subsequent layers. The effect of cheese rind on migration of DEHA was studied in Edam and Kefalotyri cheeses. The DEHA migration after 240 h into the first 1 mm beneath the surface of Kefalotyri cheese was 22.4 mg/kg, while DEHA was not detected in Edam cheese.

Adipates↗
PubMed1983

The neutrophil response to polyvinyl sponge implantation.

Neutrophil release and migration in mice were studied over a 24-hr period after the sc implantation of a single polyvinyl sponge. The release of neutrophils from the marrow was evaluated by directly counting the residual neutrophils in the femoral marrow of animals with sponges. Sponge and tissue neutrophil content was determined by extraction and assay of myeloperoxidase (MPO), a marker enzyme for neutrophils. A maximum depletion of 48% of the mature neutrophils in the marrow was observed 5 hr after sponge implantation, in keeping with significant release of neutrophils for migration to the sponge. The released cells were not found in the circulating granulocyte pool, since neutropenia was noted. The accumulation of neutrophils in the sponge increased throughout the 24-hr period, whereas in the tissue adjacent to the sponge maximum accumulation of neutrophils occurred within 7 hr. In fact, neutrophils migrated to at least three sites--the sponge, the skin overlying the sponge, and the skin in which an incision had been made to insert the sponge. The sponge content of neutrophils represented 0.3-33% of the neutrophils migrating to the combined lesion (sponge and skin sites). Therefore, if the neutrophil response to foreign body implantation is to be measured in its entirety, it is necessary to quantify not only the neutrophils within the foreign body but also those in the tissues surrounding it. These studies describe an animal model for neutrophil release and migration to tissues following a standard stimulus. It is proposed that this model may be useful in exploring the factors which influence the release and migration of neutrophils in vivo.

Animals↗