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At least 523 records · Page 29Linked to original sources
PubMed1990

Sorption of various drugs in polyvinyl chloride, glass, and polyethylene-lined infusion containers.

The sorption of chloroquine sulfate, diazepam, isosorbide dinitrate, lorazepam, midazolam, nitroglycerin, promethazine hydrochloride, thiopental sodium, and warfarin sodium to three types of containers was studied. Appropriate amounts of the drugs were added to 500 mL of 0.9% sodium chloride injection in polyvinyl chloride (PVC) bags, glass bottles, and Clear-Flex bags composed of a laminate of polyethylene, nylon, and polypropylene. The containers were stored in the dark at room temperature for 24 hours. Samples were taken at various intervals and assayed for drug concentration by high-performance liquid chromatography. There were no appreciable changes in pH after 24 hours, and all the admixtures remained clear and colorless. The potency of chloroquine sulfate, lorazepam, midazolam, promethazine hydrochloride, and thiopental sodium remained unchanged in glass, PVC, and Clear-Flex containers. Diazepam, isosorbide dinitrate, nitroglycerin, and warfarin sodium did not show any sorption to glass bottles and Clear-Flex bags. In PVC bags, however, up to 55% of diazepam, 23% of isosorbide dinitrate, 51% of nitroglycerin, and 24% of warfarin sodium was lost during the 24-hour study period. Diazepam, isosorbide dinitrate, nitroglycerin, and warfarin sodium in 0.9% sodium chloride injection showed a loss of potency when stored in PVC containers for 24 hours at room temperature, but none of the drugs studied lost potency when stored in glass bottles and Clear-Flex bags.

Adsorption↗
PubMed1989

[Experimental studies of the esophageal prosthesis with a polyvinyl alcohol hydrogel].

Though various prosthetic materials have been experimented with for use as an artificial esophagus in the past, the two main problems that have prevented successful clinical implantation of such a prosthesis were anastomotic leakage and stricture formation of the artificial esophagus. The purpose of this study is to evaluate a high water content polyvinyl alcohol hydrogel (PVA-H) for use as the esophageal prosthesis. In 10 adult mongrel dogs, the defect after resection of the intrathoracic esophagus was bridged with a PVA-H esophageal prosthesis, 5.5 cm in length and 15 mm in internal diameter with two Tefron rings, installed 2 cm from each end. The esophageal prostheses, including the anastomotic lines, were enveloped by Dacron mesh after implantation. After implantation, the prostheses were examined endoscopically and fluoroscopically. The dogs, which were sacrificed or had died, were evaluated macro- and microscopically. Among the six dogs underwent operation, one is still living 900 days after implantation. The other two dogs were sacrificed on 165 and 162 days after implantation. The remaining three dogs died of postoperative complications ranging from 25 to 81 days after implantation. The causes of death were the respiratory insufficiency after endoscopical examination, abscess formation around the prosthesis and pyothorax. Up to 2 months after implantation the esophageal prostheses were fixed to the host esophagus without stenosis. However, the prostheses were gradually dislodged due to constricture depending on the growing granulation at the proximal anastomosis. When the surviving dog was examined on the 376th day after the operation, the esophageal prosthesis fell off entirely.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Sequential MRI and CT monitoring in cryosurgery--an experimental study in polyvinyl alcohol gel phantom].

The purpose of this investigation is to detect a cryolesion by MRI and CT during cryosurgery. A fundamental study was performed to demonstrate MR and CT images of polyvinyl alcohol (PVA) gel, which was used as a phantom for MRI, under the condition of low temperature. MRI was performed on a 0.1 Tesla system (ASAHI MR Mark-J). As the temperature lowered, the unfrozen PVA gel showed decreases in T1 and T2, and an increase in signal intensity on the low flip (LF) angle images, which were obtained using 60 degrees of flip angle, Tr of 100 msec, Te of 18 msec with gradient echo acquisition method. The frozen PVA gel showed no signal intensity on the LF images and zero in T1 and T2. On the other hand, the CT images revealed the frozen area of the PVA gel as a hypodense area. From the facts described above, it may be concluded that MRI and CT will be able to detect cryolesions during cryosurgery.

Cryosurgery↗
PubMed1989

[Experimental canine hepatic artery embolization with polyvinyl alcohol microspheres].

Polyvinyl alcohol microsphere impregnated with barium sulfate was found to be a good embolizing agent in regard to shape, suspension and distribution in the arteries. Different-phase hepatic artery embolization with microspheres (50 approximately 100 microns, 100 approximately 300 microns) was performed in 20 dogs to evaluate the angiographic and histopathologic changes and hepatic function alterations. Permanent occlusion of the peripheral arterioles was observed on follow-up angiograms one week to six months after embolization. Shrinkage of the embolized segment and focal infarct of the liver were noticed in nearly half of the specimens both grossly and microscopically. The shape and structure of the microspheres were seen unchanged on different-phase specimens, and microspheres as small as 50 microns could reach the corresponding small peripheral arterioles. The liver function alterations were comparable with gelfoam embolization. This study suggested that permanent embolization of small arterioles was possible with such microspheres.

Animals↗
PubMed1988

Delivery of paraldehyde in 5% dextrose and 0.9% sodium chloride injections through polyvinyl chloride i.v. sets and burettes.

The delivery of paraldehyde in 5% dextrose injection and 0.9% sodium chloride injection was studied, and the potential interaction between paraldehyde and plastic i.v. containers and sets was evaluated. Paraldehyde was mixed with either 5% dextrose injection or 0.9% sodium chloride injection in polyvinyl chloride (PVC) bags to form a 4% solution. The bags were fitted with standard i.v. administration sets or burettes with administration sets. The solutions were allowed to drip through the i.v. sets for six hours at room temperature. Samples were taken from the i.v. bag or burette and from the distal end of the i.v. sets at zero, two, four, and six hours. Paraldehyde concentrations were measured using a stability-indicating gas chromatographic method, and the presence of plasticizers was detected by a scanning ultraviolet spectrophotometer. The cumulative amount of paraldehyde delivered at the end of the administration set at six hours was 84% for 5% dextrose solutions in burettes, and 89% or 90% for all other solutions and i.v. sets. An ultraviolet-light-absorbing substance appeared in some of the samples, although a relationship between the presence of this substance and type of solution, time of sampling, or site of sample did not emerge. Particulate matter appeared after two hours in all burettes. Approximately 10%-16% of paraldehyde in 5% dextrose or 0.9% sodium chloride injection is lost when delivered from PVC i.v. bags through standard i.v. administration sets and burettes over a six-hour period.(ABSTRACT TRUNCATED AT 250 WORDS)

Drug Stability↗
PubMed1988

Regression of ocular melanoma metastatic to the liver after hepatic arterial chemoembolization with cisplatin and polyvinyl sponge.

Thirty patients with ocular melanoma metastatic to the liver were treated by hepatic arterial chemoembolization using an admixture of cisplatin and polyvinyl sponge. Tumor regression was complete in one patient and partial (greater than 50%) in 13 patients. The total response rate was 46%. The median survival for the entire group was 11 months (95% confidence interval, nine to 18 months). Treatment-related morbidity was short-lived and included primarily severe upper right quadrant abdominal pain, transient paralytic ileus, and nonicteric hepatitis. Hepatic arterial chemoembolization provided effective palliation, with good-quality survival among 46% of patients with ocular melanoma metastatic to the liver.

Adult↗
PubMed1986

Studies of glomerular mesangial uptake and processing of macromolecules. I. Effect of polyvinyl alcohol-induced macrophages on uptake of iron dextran.

The influence of prior glomerular mesangial uptake of a macromolecule that induces the infiltration of macrophages (M phi) into the mesangium on the uptake of a second macromolecule by the mesangium was studied in inbred Lewis rats. Renal transplantation of kidneys from rats previously injected with polyvinyl alcohol (PVA) was performed to avoid the potential influences of ongoing uptake of PVA and altered host milieu on the glomerular uptake of iron dextran (ID), a macromolecule that localizes primarily in the intrinsic mesangial cells of unmodified rats. In contrast to that in the recipient's native kidney, the uptake of ID was markedly increased in the glomeruli in kidneys previously exposed to PVA. This enhanced uptake was the consequence of the phagocytic activity of mesangial M phi elicited by and containing PVA since the site of increased ID content was shown by ultrastructural studies to be within mesangial M phi. Isogeneic renal transplantation per se did not influence mesangial function since the glomerular uptake of ID in donor and recipient kidneys was the same when donors were normal rats. In addition to the enhanced uptake of ID into lysosomes by mesangial M phi these cells were also much more active in the further processing of ID to ferritin particles within the cytoplasm than were intrinsic mesangial cells. These studies demonstrate that M phi attracted to the mesangium by a stimulus such as PVA may have important effects on the consequences of additional challenges to the mesangium.

Animals↗
PubMed1987

Permeability of latex and polyvinyl chloride gloves to fluorouracil and methotrexate.

The permeability of latex surgical and polyvinyl chloride (PVC) examination gloves to fluorouracil and methotrexate was studied using a radiotracer method. Drug-tracer solutions for both drugs were prepared by combining tritiated fluorouracil or methotrexate with fluorouracil or methotrexate injection, respectively. Drug-free solutions were also prepared to be as similar as possible to the vehicles of the commercial injections. Each half of a total of 40 equilibrium-dialysis cells (20 for each glove type) was filled with either the drug-tracer solution or the drug-free solution. The cell halves were then sealed with glove membranes cut from each type of glove and fastened together so that the drug-tracer and drug-free solutions of each respective drug were opposite one another. Samples were collected after 5 to 45 minutes from each dialysis-cell well and analyzed for drug using liquid scintillation counting techniques. Microgram levels of both drugs were detected in the drug-free dialysis wells for both glove types at each sampling time. Except for the methotrexate drug-labeled well sealed with the PVC glove membrane, the amount of drug in the dialysis wells was significantly different at different sampling times. The variability in results using gloves from different lots was also significantly different for both types of gloves. Overall, latex gloves were significantly less permeable than PVC gloves to fluorouracil, and PVC gloves were significantly less permeable to methotrexate than latex gloves. The latex and PVC gloves used in this study both exhibit time-dependent permeability to fluorouracil and methotrexate.(ABSTRACT TRUNCATED AT 250 WORDS)

Dialysis↗
PubMed1987

Release kinetics of potassium aspartate in polyvinyl chloride matrix formulation.

The authors prepared potassium aspartate matrix tablets in combination with polyvinyl chloride. The physical parameters were measured and the dissolution rates were determined. During the in vitro release rate experiments, it was determined that the dissolution kinetics obey both zero order and Higuchi diffusion model order kinetics.

Aspartic Acid↗
PubMed1986

Treatment of hepatic metastases in ocular melanoma. Embolization of the hepatic artery with polyvinyl sponge and cisplatin.

Patients with ocular melanoma have a high incidence of hepatic metastases, which primarily determine their length of survival. In an attempt to control the neoplastic disease in the liver, embolization of the hepatic artery with a combination of polyvinyl sponge (Ivalon) and a suspension of cisplatin was performed in two patients with hepatic metastases from ocular melanoma. Dramatic regression of the hepatic metastases, lasting 19 and six months, occurred in these two patients after one or two such treatments. Our preliminary, albeit successful, experience with this therapeutic approach suggests that it may offer relatively prolonged periods of remission and warrants further investigation.

Adult↗
PubMed1977

Effects of a plasticizer leached from polyvinyl chloride on the subhuman primate: a consequence of chronic transfusion therapy.

The effects of di-2-ethylhexyl phthalate (DEHP) on hepatic function and histology were evaluated in the rhesus monkey undergoing chronic transfusion. DEHP was solubilized as a result of leaching by platelets or plasma stored in polyvinyl chloride (PVC) blood bags. The average cumulative amount of DEHP infused in 1 year was 69.3 mg., or 21.3 mg./kg. Comparable amounts of DEHP are received by patients who undergo chronic transfusions with whole blood, packed cells, platelets, and plasma in the same time period. Four of the seven PVC-transfused monkeys had abnormal 99mTc liver-spleen scan ratios, four of the seven demonstrated abnormal BSP clearance, and six of the seven had abnormal liver histopathology upon completion of transfusion therapy. These findings persisted in a majority of the monkeys throughout the follow-up period. DEHP persisted in the tissues for up to 14 months after transfusion. The nontransfused monkeys and those transfused with platelets processed in polyethylene containers were normal.

Animals↗
PubMed1985

Sorption of amiodarone to polyvinyl chloride infusion bags and administration sets.

The loss of amiodarone from i.v. admixtures to flexible polyvinyl chloride (PVC) infusion bags and i.v. administration sets was studied. Admixtures containing amiodarone hydrochloride 600 micrograms/mL and either 5% dextrose injection or 0.9% sodium chloride injection were stored at room temperature in glass bottles (both with and without contact of the drug solution with the rubber bottle closure), in flexible PVC bags, or in rigid PVC bottles. After 120 hours, the contents of each flexible PVC bag were emptied and replaced by methanol, which was allowed to remain in the bag for an additional 120 hours and was then analyzed for amiodarone content. To determine availability of amiodarone after infusion through a 1.8-m PVC i.v. administration set, solutions stored in glass containers were run through the set at 0.5 mL/min for 90 minutes. Samples of drug solutions were collected at appropriate intervals and analyzed by a stability-indicating high-performance liquid chromatography (HPLC) assay. Admixtures containing 0.9% sodium chloride injection were not stable; visual incompatibility was evident after 24 hours of storage in glass bottles, and no further testing was performed. In admixtures containing 5% dextrose injection that were stored in 50-mL flexible PVC bags, 60% of the initial amiodarone concentration remained after 120 hours; approximately half of the lost drug was recovered with the methanol. In effluent collected from the PVC administration set, 82% of the initial amiodarone concentration remained. Amiodarone concentrations did not decrease appreciably, after storage in glass or rigid PVC bottles, indicating that drug loss was probably affected by the plasticizer, di-2-ethylhexyl phthalate.(ABSTRACT TRUNCATED AT 250 WORDS)

Adsorption↗
PubMed1981

Inhibition of reverse transcriptase by polyvinyl sulfate (PVS).

The effect of the ribonuclease inhibitor polyvinyl sulfate on the activity of retroviral DNA polymerase and terminal c transferase was examined. This substance was found to be a potent inhibitor of these enzymes by virtue of competition between the sulfated sidechains of the molecule and the template primer for a site on the enzyme. The significance of these findings in relation to searching for reverse transcriptase is discussed.

DNA Nucleotidyltransferases↗
PubMed1981

Unmodified phagocytosis after periodate treatment of human granulocytes separated by a two-step method using Ficoll-Hypaque and polyvinylic alcohol medium.

A two-step method separating granulocytes and mononuclear cells from a single sample of 10 ml human blood is described. The technique combines a Ficoll-Hypaque treatment and a sedimentation in a Polyvinylic alcohol medium. This method (FHP) is then compared to the Ficoll-Hypaque-Dextran procedure. The FHP method requires approximately 2 h to be carried out and results in the preparation of granulocytes (greater than 99% purity) with high yield (40.7 % +/- 9.1). The cell viability exceeds 95%. Moreover the enzymic and phagocytic properties of polymorphonuclear cells are preserved after isolation. This method is then applied to study the influence of periodate treatment on nonspecific phagocytosis. In contrast with monocytes, we observed no decrease of phagocytic process.

Cell Separation↗
PubMed1983

Uptake of polyvinyl alcohol by macrophages in the glomerular mesangium of rats. Histologic and functional studies.

Rats received daily subcutaneous injections of the synthetic polysaccharide polyvinyl alcohol (PVA) for 1-28 days. The amount of PVA localized in the glomerular mesangium increased progressively during this time. By 28 days, all glomeruli showed extensive intracellular mesangial sequestrations of PVA, causing marked widening of mesangial areas, while the peripheral capillary loops were unaltered. Overall glomerular hypercellularity was mild to moderate, occurring mainly in areas of PVA deposition. Follow-up studies after 6, 12, 26, and 40 weeks revealed partial reduction of glomerular PVA masses. The PVA deposits were frequently associated with nonspecific esterase (NSE)-positive cells. The number of NSE-positive cells per glomerular tuft section increased from 0.1 in controls, to 2.1, 4.0, and 4.5 after 3, 14, and 28 days of PVA treatment, respectively. Similarly, glomerular counts for Ia-antigen-bearing cells rose from 2.1 in controls to 4.8 on Day 3 and showed further increases at later time periods with confluent staining of clusters of Ia-positive cells. In glomeruli, Ia-bearing cells were mainly noted in PVA-positive mesangial areas. These results indicate that PVA is taken up in the glomerulus primarily by cells that are NSE- and Ia-antigen-positive, suggesting that these cells are activated blood-borne monocyte-macrophages that sequester this polysaccharide. Clearance studies revealed that the glomerular filtration rate and effective renal plasma flow remained normal after 4 weeks of PVA injections. PVA-treated rats showed only mild elevations of urinary protein excretion. These findings indicate that confinement of marked structural and cellular alterations to the mesangium, even including the presence of infiltrating monocyte-macrophages, is compatible with absent or minimal dysfunction of the glomerular ultrafilter.

Animals↗
PubMed1983

Role of macrophages in the glomerular mesangial uptake of polyvinyl alcohol in rats.

Glomerular mesangial cell populations were characterized through sequential morphologic studies after injection of polyvinyl alcohol (PVA), a synthetic polysaccharide previously shown to accumulate in the mesangium. Renal tissue was obtained from groups of rats, 1 day to 28 days after initial subcutaneous injection of PVA, and studied by transmission electron microscopy and fluorescence microscopy using monoclonal antibodies to rat Ia. PVA was initially present in areas of attenuated mesangial matrix. Subsequently, only a small fraction of PVA was associated with "classical" mesangial cells. By 3 days, variable degrees of glomerular hypercellularity were noted, and PVA appeared within phagocytic vacuoles of immature macrophages in the mesangium and in occasional endocytic vacuoles of endothelial and mesangial cells. At later time points, increasing quantities of PVA were found within the large confluent phagolysosomes of more mature mesangial macrophages. By 2 weeks, features of epithelioid transformation were evident. By 3 and 4 weeks many glomeruli contained several mesangial microgranulomas, i.e., collections of epithelioid cells of variable degree of maturation, including giant cells. An increase in Ia-positive cells in glomeruli corresponded closely to the increase in numbers of cells with ultrastructural characteristics of macrophages and epithelioid cells within mesangial regions. These studies demonstrate a primary role for macrophages in the uptake of PVA, a process ultimately leading to granuloma formation in the mesangium.

Animals↗
PubMedDate not supplied

Histopathologic analysis of intraarterial polyvinyl alcohol microemboli in rat cerebral cortex.

Polyvinyl alcohol (PVA) foam particles have been used with success in both experimental and clinical embolization of vascular lesions. Cellular response to PVA has been well documented outside, but not within, the central nervous system. This study was directed specifically at the cellular response to PVA in rat brain vasculature. By using small numbers of microparticles, an effort was made to define the response to PVA alone, rather than associated occlusions or infarctions. It was determined that PVA elicited no significant inflammatory response in the embolized vessels nor in the surrounding tissue. The isolated fragments did not appear to alter the blood-brain barrier. The PVA microemboli were extremely adherent to vascular endothelium, lodging in vessels of larger diameter and in relatively high-flow locations without actually wedging within the vessel lumen. On the basis of this analysis, it was determined that PVA foam has properties suitable for an intracerebral vascular embolic agent.

Animals↗