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At least 73 records · Page 4Linked to original sources
PubMed1985

Cell surface effects of adriamycin and carminomycin immobilized on cross-linked polyvinyl alcohol.

Previous reports have claimed Adriamycin to be cytotoxic to cultured tumor cells when the drug is covalently immobilized on a solid support, thus suggesting a cell surface mechanism of action for the drug. Although these previous reports attempted to rule out released drug or endocytosis of drug-support particles as alternative explanations for the observed cytotoxicity, a more thorough analysis is necessary to substantiate fully the cell surface idea. In the present work, the stability of the drug-support linkage was increased by use of cross-linked polyvinyl alcohol as the support and cyanuric chloride or a diazonium salt for attachment of the drug. Different anthracycline orientations were tested by coupling Adriamycin at the amino sugar and carminomycin at the D-ring. The Adriamycin cross-linked polyvinyl alcohol and carminomycin cross-linked polyvinyl alcohol preparations had much lower drug release rates than did the earlier used carbamate-linked Adriamycin cross-linked agarose materials. All three immobilized drug preparations inhibited the growth of L1210 or S180 clones following 2- or 20-h incubation with cells at 37 degrees C. The results strongly support the concept that immobilized anthracyclines can be cytotoxic to cultured cells, for at least two different orientations of the drug on the support.

Animals↗
PubMed1978

Mouse skin carcinogenicity tests of the flame retardants tris(2,3-dibromopropyl)phosphate, tetrakis(hydroxymethyl)phosphonium chloride, and polyvinyl bromide.

The flame retardants tris(2,3-dibromopropyl)phosphate, tetrakis(hydroxymethyl)phosphonium chloride, and polyvinyl bromide were tested for carcinogenic activity by skin application 3 times weekly in random-bred female ICR/Ha Swiss mice for 420 to 496 days. Tris(2,3-dibromopropyl)phosphate at two dose levels (30 mg and 10 mg/application) induced benign and malignant tumors of the skin, forestomach, and oral cavity (tongue and gingiva) in a statistically significant number of mice (30/group). A statistically significant incidence of papillary tumors of the lung was observed at both dosages, and the higher dose also resulted in one mouse with a tubular adenoma of the kidney. Tetrakis(hydroxymethyl)phosphonium chloride (2 mg/application, 60 mice) and polyvinyl bromide (0.1 ml latex suspension/application, 30 mice) were inactive. Polyvinyl bromide was also injected s.c. into another group of female ICR/Ha Swiss mice once weekly for 48 weeks, and the mice were observed for a total of 60 weeks. Liposarcomas were induced in 19 of 30 mice, which was ascribed to physical carcinogenesis. Appropriate solvent and no-treatment control groups were included.

Administration, Topical↗
PubMed1993

[Pharmacokinetics of acetaminophen in individuals occupationally exposed to polyvinyl chloride modified with plasticizers].

The aim of this study was to evaluate the health state of a random group of subjects occupationally exposed to polyvinyl chloride. The emphasis was put on the hepatic functional tests in comparison with acetaminophen pharmacokinetics. Forty two males were assigned to two groups: the control group free from occupational exposure and the group exposed to polyvinyl chloride. The latter one was divided into two subgroups according to the length of exposure. The following examinations were carried out in all subjects: subjective and physical examinations, basic laboratory and functional hepatic tests, radioisotope examinations of the liver and spleen, and acetaminophen pharmacokinetics was analysed as well. Acetaminophen was administered intragastrically in a single dose of 1.0 g. Blood was collected within 24 hrs after drug administration. The method of Routh et al. was used for determination of paracetamol concentration. A two-compartment open model for extravascular administration was used for calculation of pharmacokinetic parameters. The results suggest that polyvinyl chloride leads to an accelerated acetaminophen biotransformation, regardless of the length of occupational exposure. There was no correlation between changes in paracetamol metabolism and standard functional hepatic tests. The acetaminophen test can be useful in detecting alterations in the activity of hepatic microsomal enzymes, a symptom of early occupational exposure to chemical compounds with potential hepatoxic properties.

Acetaminophen↗
PubMed2005

Biochemical and molecular characterization of a periplasmic hydrolase for oxidized polyvinyl alcohol from Sphingomonas sp. strain 113P3.

Oxidized polyvinyl alcohol hydrolase (OPH) and polyvinyl alcohol dehydrogenase were found to be constitutively present in the periplasm of Sphingomonas sp. strain 113P3 (formerly Pseudomonas sp. 113P3). The OPH was purified to homogeneity with a yield of 40 % and a 5.9-fold increase in specific activity. The enzyme was a homodimer consisting of 35 kDa subunits. Its activity was inhibited by PMSF, Hg(2+) and Zn(2+). The enzyme hydrolysed oxidized polyvinyl alcohol (oxidized PVA) and p-nitrophenyl acetate (PNPA), but did not hydrolyse any of the mono- or diketones tested. K(m) and V(max) values for oxidized PVA and PNPA were 0.2 and 0.3 mM, and 0.1 and 3.4 micromol min(-1) mg(-1), respectively. The gene for OPH was cloned and sequenced. Sequencing analysis revealed that the open reading frame consisted of 1095 bp, corresponding to a protein of 364 amino acids residues, encoding a signal peptide and a mature protein of 34 and 330 amino acids residues, respectively. The presence of a serine-hydrolase motif (a lipase box; Gly-X-Ser-X-Gly) strongly suggested that the enzyme belongs to the serine-hydrolase family. The protein exhibited homology with OPH of the Pseudomonas sp. strain VM15C (63 % identity) and the polyhydroxybutyrate depolymerases from Mesorhizobium loti, Rhizobium sp. and Sinorhizobium meliloti (29-32 % identity). The oph gene was expressed in Escherichia coli under the control of the lac promoter. The recombinant protein had the same molecular mass and N-terminal amino acid sequence as the purified OPH from strain 113P3.

Alcohol Oxidoreductases↗
PubMed1976

The effects of corticosterone and cortisone on the uptake of polyvinyl pyrrolidone and the transmission of immunoglobulin G by the small intestine in young rats.

1. The distribution of polyvinyl pyrrolidone along the intestinal lumen and in the intestinal wall, following oral administration to normal and corticosterone treated rats, was found to be extremely variable. Valid comparisons between the two groups of animals could not be made using this technique. 2. Three, 4 and 5 days after corticosterone treatment there was no significant change in the uptake of 125I-labelled polyvinyl pyrrolidone from standard doses injected into ligated segments of the distal small intestine; nor did the treatment induce precocious replacement of the absorptive cells in this region. Cortisone induced precocious cell replacement, a process which took up to 4 days to complete, and also led to a marked reduction in the uptake of 125I-labelled polyvinyl pyrrolidone from ligated segments of the distal intestine. 3. Three days after treatment with corticosterone (5 mg I.P. at 12 days) there was a marked reduction of labelled immunoglobulin G transport into the blood. Four and 5 days after treatment there was some recovery of the immunoglobulin G transport function. Three days after treatment with cortisone (5 mg I.P. at 12 days) there was closure of the gut to labelled immunoglobulin G. 4. The relevance of these results to antibody transmission and the termination of immunoglobulin transport is discussed.

Animals↗
PubMed1975

Morbidity associated with prolonged use of polyvinyl feeding tubes.

In two newborn infants, morbidity was associated with long-term use of polyvinyl chloride feeding tubes. In one case, a hard, sharp catheter was thought to be responsible for peritonitis. In other, the polyvinyl tube hardened into a coil that could only be extricated by introduction of an intraluminal guide wire and prolonged manipulation under fluoroscopic control. The rigidity acquired by these tubes is thought to present serious potential for morbidity and mortality. Methods and materials appropriate for short-term alimentation should no be presumed appropriate for long-term use, and alternatives should be considered.

Enteral Nutrition↗
PubMed1996

Preparation of purified atactic polypropylene and polyvinyl methyl ether surfaces for thrombogenicity studies.

Commercial samples of atactic polypropylene (aPP) and polyvinyl methyl ether (PVME) were purified and spin-cast onto glass coverslips with a view to using these as model surfaces in thrombogenicity studies. These materials differ from polyvinyl alcohol (PVA) in a single functional group and are similarly amorphous: with the same backbone they have a hydroxyl, a methoxy, or a methyl group. The objective was to understand the role of the hydroxyl group in the platelet reactivity of PVA. Surface characterization showed that they were chemically pure (as determined by X-ray photoelectron spectroscopy) but not smooth (as determined by scanning electron microscopy or interferometry), presumably due to the difficulties of spin-casting optically clear films from hot solutions (aPP or polyethylene [PE]) or because of imperfect adhesion to the saline-treated substrate (PVME). PVME was also gamma-irradiated to insolubilize it. Fewer platelets adhered to PVA than to PVME or to aPP and PE, but roughness effects and limited data preclude definitive conclusions regarding the effect of functional groups. Less protein was found on PVA than on the hydrophobic surfaces, but the significance of this observation is unclear. Further studies with more sensitive protocols are called for to examine the extent of platelet activation and its relationship to surface chemistry.

Adsorption↗
PubMed1976

Effect of phthalate plasticizer on blood compatibility of polyvinyl chloride.

The amount of a phthalate plasticizer on the surface of a sheet of polyvinyl chloride used in the fabrication of blood storage bags was quantified using attenuated total reflectance spectroscopy, water contact angle measurement, and weight loss due to methanol extraction. Water wettability increased as the amount of surface phthalate extracted by methanol increased, which indicates that the accumulation of phthalate on the surface increases hydrophobicity. The extraction of phthalate by methanol consists of two steps: (a) methanol first dissolves surface phthalate, and (b) phthalate in the bulk then diffuses through the surface. The adsorption of plasma proteins was investigated to determine the initial events as blood contacts the surface. The composition of adsorbed proteins on the methanol-cleansed surface differs from that on the uncleansed polyvinyl chloride surface. Albumin adsorption onto phthalate-contaminated surfaces is less than on cleansed surfaces while adsorption of gamma-globulin and fibrinogen is greater on phthalate-contaminated surfaces. Protein adsorption can be related to surface thrombus formation. Increases in platelet numbers appeared on phthalate-contaminated surfaces as compared with methanol-treated surfaces. A phthalate may enhance platelet adhesion and aggregation when it exists on a polymer surface.

Adsorption↗
PubMed1994

Ethylene vinylacetate copolymer particles dissolved in polyvinyl alcohol (2,000-mer) solution as an embolic material for vascular anomalies. A preliminary study.

We have prepared a new material for embolisation: ethylene vinylacetate copolymer dissolved in polyvinyl alcohol. When in contact with blood, polyvinyl alcohol rapidly becomes a soft gel, which is accompanied by wedging of the ethylene vinylacetate copolymer. We analysed the histopathology of intra-arterial microemboli in rats, after intracarotid injection of this material. We confirmed that it was applicable to embolisation for neurosurgical treatment.

Animals↗
PubMedDate not supplied

Cryopreserved red blood cells for pediatric transfusion. Frozen storage of small aliquots in polyvinyl chloride (PVC) plastic bags.

Human nonrejuvenated and rejuvenated red bood cells were prepared for cryopreservation and subsequent pediatric transfusion. Glycerol was added to the red blood cells in the primary polyvinyl chloride plastic collection bag to achieve a concentration of 40 per cent W/V. The red blood cells were concentrated by centrifugation, and the supernatant glycerol was discarded. Each glycerolized unit was divided into four equal aliquots in the individual 600-ml bags of a dry quadruple polyvinyl chloride plastic system, and each aliquot was frozen and stored at -80 C. After thawing, sodium chloride solutions were used to wash the aliquots in the IBM Blood Processor 2991-1 or 2991-2 or the Haemonetics Blood Processor 115, and the washed aliquots were stored in a sodium chloride-glucose-phosphate solution at 4 C for 24 hours. Freeze-thaw recovery of the red blood cells was about 97 per cent, and freeze-thaw-wash recovery was about 84 per cent. Twenty-four-hour posttransfusion survival values were about 92 per cent for both nonrejuvenated and indated-rejuvenated red blood cells. Nonrejuvenated red blood cells, those frozen within three to five days of collection without biochemical modification, had normal oxygen transport function at the time of transfusion; rejuvenated red blood cells, those biochemically treated with PIGPA Solution A after three to five days of storage at 4 C, had improved oxygen transport function at the time of transfusion.

Adenosine Triphosphate↗
PubMed1975

Polyvinyl chloride pyrolysis products. A potential cause for respiratory impairment.

A limited investigation of respiratory and other symptom prevalence, plus before and after shift ventilatory capacity was conducted among a group of 17 meat wrappers exposed to pyrolysis products of polyvinyl chloride and a group of 21 control subjects. Exposed meat wrappers showed a higher prevalence of cough, phlegm, hay fever, and asthma than did the control group. The exposed group also demonstrated relative decreases in forced expiratory volume, one second (FEV1.0) and forced expiratory flow 50% (FEF50) after one shift of work; whereas, the controls showed an opposite tendency. These findings suggest that meat wrappers exposed to pyrolysis products of polyvinyl chloride might be adversely affected. The results, while suggestive, are not totally conclusive owing to the fact that there was not ideal matching of the exposed and control groups in regard to age, height, race, sex, and smoking status.

Age Factors↗
PubMed1989

Acute health effects among firefighters exposed to a polyvinyl chloride (PVC) fire.

Firefighters are frequently being called on to fight fires that are chemical in nature. In the aftermath of a chemical fire in Plainfield, New Jersey on March 20-21, 1985, the authors conducted a retrospective cohort study which surveyed 80 firefighters exposed to burning polyvinyl chloride (PVC) as well as 15 nonexposed firefighter subjects. By means of an 81-item symptom checklist, exposed firefighters reported more frequent and severe symptoms at 5-6 weeks post incident. This was true for a total symptomatology score as well as 19 individual items. Some of the items with an elevated risk were consistent with exposure to hydrogen chloride, the main pyrolysis product of polyvinyl chloride. Other items with an elevated risk appeared to be related to smoke inhalation while others seemed psychosocial in nature. Analyses conducted within the exposed firefighter group showed that fighting the fire the first day, being a truckman, and residence within 1 mile (1.6 km) of the firehouse were significant risk factors for high total symptom scores. These risk factors may have been associated with level or duration of exposure to the toxic substances produced during the fire.

Acute Disease↗
PubMed1975

Liver disease among polyvinyl chloride production workers.

A protocol for systematic testing of all employees of a chemical plant is presented. This factory manufactures polyvinyl chloride compounds and resins, ABS compounds and resins, and synthetic rubber. The results were reviewed, which led to the discovery of 2 additional cases of angiosarcoma and 11 cases of portal fibrosis. Two of the 11 cases were found to have developed in employees other than polyvinyl chloride production workers.

Chemical and Drug Induced Liver Injury↗
PubMed1986

Growth characteristics of selected fungi on polyvinyl chloride film.

The objective of this study was to determine if plasticized polyvinyl chloride film would support the growth of any of nine species of fungi. The film was suspended in distilled water with no nutrients or with glucose or ammonium sulfate. Spores of each of the test species were inoculated into the suspension medium, and the mixture was incubated at 30 degrees C for up to 18 weeks. Most species were found to be capable of utilizing the film for carbon or nitrogen when the other nutrient was supplied. Only two species, Aspergillus fischeri and Paecilomyces sp., were found to be capable of utilizing components of the film without added nutrients. Components of the polyvinyl chloride film were then incorporated into mineral salts medium to determine if these components could serve as carbon sources in the presence of ammonium nitrate. The only component found to be utilized by all the fungi as a carbon source was epoxidized oil, a plasticizer-stabilizer. Calcium-zinc stearate was an available carbon source for all except the Penicillium and Verticillium strains. The only other component utilized was a stearamide, which was metabolized solely by the Aspergillus sp. Only the stearamide contained enough nitrogen to serve as a primary source in the film. The compound, however, did not support growth of fungi in the presence of glucose. It was theorized that either the nitrogen of the stearamide was more readily available to the fungi in the whole film due to the presence of trace nutrients or the nitrogen was supplied by exogenous sources.

Aspergillus↗
PubMedDate not supplied

Design and in vitro evaluation of polyvinyl chloride microcapsules containing sulphamethoxazole.

Polyvinyl chloride microcapsules containing sulphamethoxazole have been prepared by phase separation coacervation in non-aqueous solvents. Phase separation of the polyvinyl chloride in the solution of chloroform was achieved with n-hexane. Scanning electron micrographs revealed uniform encapsulation of the sulphamethoxazole particles. In vitro dissolution studies were conducted under changing pH conditions. The reproducibility of the in vitro drug release was highly significant. The mechanism of drug release was suggested as an integrated process of diffusion controlled dissolution. Controlled drug release was obtained over a prolonged period of 8 h.

Capsules↗
PubMed1989

Mixed connective tissue disease after exposure to polyvinyl chloride.

We present 4 patients fulfilling criteria for mixed connective tissue disease (MCTD) with anti-RNP antibodies, who had been previously exposed, in 4 different professions, to polyvinyl chloride. This presentation is clinically and serologically different from the classical polyvinyl chloride disease in which no such antibody can be found. Already observed in patients after cosmetic surgery, MCTD could also be a result of toxic exposure.

Adult↗
PubMed1986

Leaching of diethylhexyl phthalate from polyvinyl chloride bags into intravenous cyclosporine solution.

The release of diethylhexyl phthalate (DEHP) from flexible polyvinyl chloride containers into intravenous cyclosporine solutions was studied. Intravenous cyclosporine solution or solutions containing the vehicle Cremophor EL and alcohol in dextrose were prepared in an all-glass system and stored in polyvinyl chloride (PVC) bags. Four samples were obtained at different time intervals, and DEHP content was analyzed by gas chromatography. The amount of DEHP that was leached into solutions stored in the PVC bags increased as storage time increased. By 48 hours, nearly 33 mg of DEHP had leached into the solution. Intravenous cyclosporine solutions should be prepared in glass containers to minimize patient exposure to DEHP. If plastic bags are used for preparing cyclosporine injections, the injections must be used immediately after preparation.

Cyclosporins↗
PubMed1979

Human red blood cells with normal or improved oxygen transport function prepared and frozen in the primary polyvinyl chloride plastic blood collection container.

This is a report a a new system for freezing human red blood cells in the same polyvinyl chloride plastic container in which the blood is collected and separated into components. This polyvinyl chloride plastic collection bag with integrally attached transfer packs for blood collection, component separation, red blood cell biochemical modification, freezing, storage, and post-thaw dilution before washing, represents a major advancement in the freeze-preservation process. The label with the donor's blood type and identification number affixed to the bag at the time of collection remains in place throughout the freezing and thawing process. The transfused red blood cells are of superior quality, and the processing cost is less than with other methods of freeze-preservation. There is a lower risk of contamination with these red blood cells because manipulation of the product is kept at a minimum. "Rejuvenation", a bioengineering process by which outdated red blood cells can be salvaged, can be incorporated into the preservation process using one of the attached transfer packs of the primary collection bag. This process has been introduced as a possible means of alleviating the dramatic blood shortages which occur periodically. Red blood cells may also be "rejuvenated" after storage in the liquid state to increase their 2,3 DPG and ATP levels to 150 to 200% of normal, and these red blood cells with improved oxygen transport function have been administered to anemic patients with and without cardiopulmonary insufficiency, patients undergoing cardiopulmonary bypass and treatment with hypothermia during cardiac surgery, and in instances where nonhemolytic transfusion reactions might be expected.

Adenosine Triphosphate↗