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At least 19 recordsLinked to original sources
PubMed1990

Plasma gas discharge deposited fluorocarbon polymers exhibit reduced elutability of adsorbed albumin and fibrinogen.

The adsorption and subsequent detergent elutability of fibrinogen and albumin were measured on various treated and untreated polymer films in order to determine whether the relative adsorption of these proteins was responsible for the enhanced thromboresistance of Dacron vascular grafts treated with tetrafluoroethylene in a radio frequency glow discharge (RFGD) apparatus. Fluorocarbon-coated surfaces varying in the relative proportions of CF, CF2, and CF3 groups and in the ratio of fluorine to carbon were prepared by RFGD treatment of poly(ethylene terephthalate) (PET) films with tetrafluoroethylene or perfluoropropane. The adsorption of fibrinogen and albumin to these fluorocarbon-coated surfaces was comparable to the adsorption of the proteins to polytetrafluoroethylene (PTFE) and PET. However, the elutability of fibrinogen and albumin from the RFGD fluorocarbon surfaces with sodium dodecyl sulfate was much lower than that from PTFE or PET. Other RFGD treatments of PET, such as ethylene deposition or argon etching, did not reduce the extent of albumin elutability as dramatically as did the RFGD fluorocarbon treatments. The strong albumin binding to RFGD fluorocarbon surfaces may be exploited clinically to enhance the retention of albumin preadsorbed to blood-contacting surfaces to render them thromboresistant.

Adsorption↗
PubMed1992

A new fluorocarbon for keratoprosthesis.

Previous studies have demonstrated the potential use of microporous, biocompatible materials to improve the long-term stability of keratoprosthesis. To determine the factors that will influence corneal tissue ingrowth into biocompatible, microporous materials, we have compared three types of fluorocarbon polymers--Impra, Gore-Tex, and Proplast--after intrastromal implantation in rabbit corneas. Despite similar physicochemical structures, a great difference was observed in histologic and ultrastructural cross sections after 4- and 8-month follow-ups. For Gore-Tex, we observed extrusion of the implant and infiltration of necrotic and inflammatory cells. All implants of Proplast also led to significant corneal damage resulting in extrusion of the material. Through the use of electron and light microscopy and image analysis, this study demonstrates the presence of cell differentiation and collagen synthesis in the pores of the Impra implant. Apart from biocompatibility, this experiment demonstrates the influence of pore size, porous microorganization, and biomechanical factors on prosthetic corneal material. Only Impra offers satisfactory interface, allowing fibroblastic cells and neocollagen synthesis into its pores, and it can become transparent.

Animals↗
PubMedDate not supplied

Pharmacolinetics of fluorocarbon 11 and 12 in dogs and humans.

Blood levels and exhalation bag contents of FC-11 and FC-12 from dogs and humans were used to elucidate the pharmacokinetic model describing the time-course of these agents. The derived pharmacokinetic parameters were in good agreement with the physicochemical properties of these substances. The model was used to estimate the percentage of dose absorbed, which averaged 77 per cent for FC-11 and 55 per cent for FC-12, and to predict the level of FC-11 and FC-12 under a variety of conditions simulating both short- and long-term exposure to the maximum allowable concentrations of these agents. With similar doses, an 8-hour continuous exposure was estimated to produce levels of FC-11 and FC-12 that are much lower than the corresponding levels reported to induce cardiac sensitization in dogs.

Animals↗
PubMed1975

Determination of fluorocarbon in blood.

Because fluorocarbons can dissolve relatively large quantities of oxygen and carbon dioxide, there is considerable interest in utilizing them to develop new methods of extracorporael circulation, artificial red blood cells, and liquid breathing techniques. A method for the assay of fluorocarbon in blood is presented. The fluorocarbon is extracted from the blood with toluene, and fluoride is released from the fluorocarbon in the toluene extract by reaction with sodium biphenyl. The inorganic fluoride is then extracted with aqueous sodium acetate, the pH of the extract is adjusted, and the activity of the fluoride ion is read with a fluoride-specific ion electrode. The assay was effective for fluorocarbon concentrations in the range of 1 to 30 ppm.

Biphenyl Compounds↗
PubMed1975

Fluorocarbon aerosol propellants V: binding interaction with human albumin.

Binding of trichloromonofluoromethane, dichlorodifluoromethane, and dichlorotetrafluoroethane was studied in aqueous 5% human albumin solution, using the partition coefficient method in sealed serum bottles. The partition coefficient and the fraction of fluorocarbons bound were highly dependent on fluorocarbon concentrations. The average binding sites per molecule of albumin were 2.17, 0.30, and 0.42 and the binding association constants were 1.11 X10-3, 1.73 X10-3, and 5.06X10-3 M-minus 1, respectively. At the lowest concentration studied, 62.3, 25.5, and 65.6% were found bound to albumin, respectively. This appears to represent the first extensive study on any gas-albumin interaction.

Aerosol Propellants↗
PubMed1975

Vertical gradients of pleural and transpulmonary pressure with liquid-filled lungs.

In supine dogs with saline-filled lungs the vertical gradient of pleural surface pressure (VGPpl) was not significantly different from -1 cm H2O/cm and that of transpulmonary pressure (VGPtp) was not significantly different from zero. Hence the hydrostatic gradient of the liquid was entirely taken up by the chest wall, the ribs being rigid in the direction of gravity and the diaphragm facing an equal hydrostatic gradient on both sides. In head-up dogs VGPpl was -0.8 cm H2O/cm when the level of the liquid in the filling system was 19.5 cm below the lung top and -0.5 cm H2O/cm when this level corresponded to the top. The hydrostatic gradient of the liquid was not entirely taken up by the rib cage because of its uneven regional compliance and VGPtp was reversed with respect to that of the air-filled lung. With fluorocarbon (specific gravity 1.75) filled lungs in the supine posture VGPpl was about -1.28 cm H2O/cm and VGPtp was reversed. In the head-up posture VGPpl was about -1.2 cm H2O/cm and VGPtp was reversed.

Airway Resistance↗
PubMed1975

Cardias arrhythmias in hypoxic rabbits during aerosol propellant inhalation.

Rabbits were exposed for four minutes to combinations of oxygen (21%, 11%, or 7%) and fluorocarbon-11 (0%, 5%, or 15%). Exposure to 7% oxygen-15% fluorocarbon-11 caused cardiac arrhythmias in all rabbits exposed. These bradyarrhythmias developed at levels of arterial hypoxemia that did not cause arrhythmias in rabbits exposed to 7% oxygen alone. In contrast with recent reports, hypoxia and this aerosol propellant do appear to have an interactive effect on cardiac rhythm.

Aerosol Propellants↗
PubMed1978

Penetration of soil dust through woven and nonwoven fabrics.

Several types of fabrics were laboratory-tested for their effectiveness in workers protection to pesticide-laden dust encountered in the agricultural environment. Of the applied less than 100 mesh dust, penetrations through knitted jersey and woven fabrics were greater than 87% and less than 5.8%, respectively. Treatment of woven fabrics with fluorocarbon polymers curtailed penetration by greater than 60%. Nonwoven fabrics allowed less than 0.5% dust penetration. Parathion mixed with 100-mesh sieved dust resulted in increasing "ppm" levels with decreasing particle size; extent of parathion conversion to paraoxon was independent of particle size for the sandy loam dust used.

Agricultural Workers' Diseases↗
PubMed1976

Death due to fluorocarbon inhalation.

The abuse of inhalation of aerosol preparations containing fluorocarbons as the propellant is a potentially lethal act. I report a death believed due to inhalation of an aerosol propellant.

Adolescent↗
PubMed1975

Chlorofluorocarbon sources of environmental contamination.

The quantities of chlorofluorocarbons (FCC's) used commercially in the United States and globally are reviewed, and estimates of environmental release from the applications are made. The results indicate that sizable quantities of the FCC's that have been produced have not yet reached the environment and that regulation of U.S. applications would partly reduce, but not end, the possible destruction of stratospheric ozone.

Environmental Pollution↗
PubMed1976

Purification of influenza virus with Arcton 113.

Arcton 113 has proved effective in the removal of host membrane fragments which cosediment with influenza virus during differential centrifugation. The virus appeared morphologically undamaged by the procedure and retained its infectivity, neuraminidase, and hemagglutinating activity. Pyrogenicity, however, was considerably reduced.

Fluorocarbon Polymers↗
PubMed1975

Oxygen transport of colloidal fluorocarbon suspensions in asanguineous rabbits.

In anesthetized, oxygen-breathing rabbits, the entire blood volume was exchanged with a 20% colloidal fluorocarbon fluid suspension of high gas solubility. In contrast to the control animals with acute isovolemic and hypervolemic hemodilution, the fluorocarbon suspension prevented the decrease in arterial oxygen content below a hematocrit of 13%. However, the more pronounced effect of the fluorocarbon suspension on oxygen delivery occurred at higher hematocrits and was due to its efficiency as a plasma expander, since it increased the cardiac output even above the level of the hypervolemic hemodilution group. The fluorocarbon suspension also raised arterial blood pressure and total peripheral resistance due to its increased viscosity. Thus, in mild hemodilution, the fluorocarbon suspension kept oxygen utilization in the normal range by increasing cardiac output, and in extreme hemodilution it improved oxygen utilization by also raising the arterial oxygen content and arterial blood pressure. The survival time of the isovolemic control animals was 31.6 min, it was extended to 57.8 min in the hypervolemic control animals, and the rabbits with the fluorocarbon suspension lived for 124.8 min.

Animals↗
PubMed1975

Residual levels and biochemical changes after ventilation with perfluorinated liquid.

Twenty-three beagle dogs were ventilated with perfluorinated liquid, perfluoro-1-isopropoxy-hexane (Caroxin-F) for 1 h and were reconverted to gaseous breathing. Hematologic and biochemical changes were studied in five dogs for 1 yr and the remaining animals were followed for evidence of retained Caroxin-F for up to 3 yr. We found that the dogs could be ventilated with liquid Caroxin-F and returned to spontaneous breathing of gaseous oxygen with normal blood gas exchange within 24-72 h. Serum alkaline phosphatase, serum cholesterol, and white blood cell count increased with liquid ventilation but returned to normal in less than 1 wk. Trace amounts of Caroxin-F were detected by chromatography in all tissues studied for the entire 3-yr period. The highest levels of Caroxin-F were found in the lungs and associated lymph nodes. No histologic evidence of the presence of Caroxin-F was seen except for local accumulations of vacuolated macrophages in the lungs and associated lymph nodes. We conclude that Caroxin-F can be breathed without residual deleterious effects, even though trace amounts remained for at least 3 yr.

Alkaline Phosphatase↗
PubMed1976

Gas embolism due to intravenous FC 80 liquid fluorocarbon.

Lethal gas embolism always occurs after FC 80 liquid fluorocarbon is injected intravenously (0.1 ml/kg body mass) in dogs breathing room air but not in dogs breathing oxygenated FC 80 liquid fluorocarbon. Gas embolism is not prevented in dogs that have been injected intravenously with FC 80 when they are exposed to 2 ATA (atmospheres absolute) 20% 02-80% N2, 9 ATA 5% O2-95% He, or 1 ATA 100%, O2. In dogs that die of FC 80-induced gas embolism, free gas in the right atrium contains approximately 0.5 g FC 80/liter, and Po2 and Pco2 in the gas are in equilibrium with their corresponding tensions in right atrial blood. These observations are consistent with the hypothesis that PFC 80 in alveolar gas does not equilibrate with PFC 80 (55 mmHg) in blood. The total gas tension in pulmonary capillary blood containing FC 80 and its vapor thus exceeds the total tension of alveolar gases (atmospheric pressure). Bubbles of O2, CO2, N2, FC 80, and water vapor form in the regions of the pulmonary capillary bed where the total tension of gases dissolved in blood exceeds the absolute blood pressure.

Animals↗
PubMed1976

A new type of fluorocarbon liquid oxygenator.

A new oxygenator based on gas transfer across liquid-liquid interfaces (liquid oxygenator) is introduced. Perfluorinated chemicals are used as gas carriers. This liquid oxygenator differs from others in its concept basing on the dispersion of the blood droplets in an inert liquid by means of shear forces. This method allows high efficiency both with respect to saturation and to required blood flow. The results of gas transfer experiments in vitro and in vivo are satisfactory.

Animals↗
PubMed1976

Study on the binding of trichloromonofluoromethane by bovine serum albumin using a fluorescent probe technique.

Protein binding of the aerosol propellant, trichloromonofluoromethane, was studied in bovine serum albumin (BSA) solutions using the fluorescent probe technique. The propellant displaced the probe, 8-anilino-1-naphthalenesulfonate, from its binding sites and reduced the fluorescence intensity. The binding association constants, the number of binding sites, and the competitive nature of the binding interaction were investigated. The hydrophobic nature of the binding and the implication of binding displacement interactions between the fluorocarbon and plasma-protein-bound drugs were also discussed. The fatty acid impurities present in the commercial BSA were found to have no effect on the protein binding of the propellant.

Aerosol Propellants↗