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At least 19 recordsLinked to original sources
PubMed1975

Determination of fluorocarbon 11 and fluorocarbon 12 in post-mortem tissues: a case report.

This report describes the death of a teenager due to inhalation of fluorocarbon aerosol propellants and presents a method for the determination of trichlorofluoromethane (fluorocarbon 11) and dichlorodifluoromethane (fluorocarbon 12) in post-mortem samples. The post-mortem blood and tissue levels of these fluorocarbons are also presented. The distribution of fluorocarbon 11 and fluorocarbon 12 is similar to that observed in chloroform deaths.

Adolescent↗
PubMed1991

Fluorocarbon/lecithin emulsions: identification of EYP-coated fluorocarbon droplets and fluorocarbon-empty vesicles by freeze-fracture electron microscopy.

Freeze-fracture has been used to examine perfluorodecalin/egg yolk phospholipid emulsions (70:8, w/v%) destined to be used as injectable oxygen carriers. The fluorocarbon displays a specific granular aspect upon freeze-fracture which makes it readily recognizable and allows the distinction between two populations of objects on the micrographs: fluorocarbon droplets and water-filled lipid vesicles.

Egg Yolk↗
PubMed1975

Effect of fluorocarbon emulsions on the mechanical fragility of normal and sickle cells: in vitro studies.

Mechanical fragility measurements have been made in vitro on fluorocarbon emulsions mixed with normal and sickle cells in plasma to determine the effect of fluorocarbon. Emulsions of FC-80 with Pluronic F-68 were added to give final solutions of 0, 1, 5, 10, and 20% fluorocarbon emulsion. The effect of the fluorocarbon emulsion was observed in the presence and absence of oxygen. In the presence of oxygen, there was no effect of the fluorocarbon emulsion on the mechanical fragility of normal or sickle cells. In deoxygenated systems, however, there was significantly less hemoglobin in the plasma during the mechanical fragility test with fluorocarbon emulsion added to sickle cell blood. The normal blood was not affected by the fluorocarbon emulsion in the deoxygenated system. Five percent of fluorocarbon emulsion was required for a significant effect on the deoxygenated sickle cells. Since the effect of the fluorocarbon emulsion was in a deoxygenated condition, the effect is due to the presence of the fluorocarbon emulsion and not its oxygen carrying capability.

Anemia, Sickle Cell↗
PubMed1977

Mass transfer properties of gases in fluorocarbons.

The solubility and diffusion coefficient of oxygen and carbon dioxide were measured in both the pure and emulsified of two fluorocarbons, perfluorotributylamine and perfluorobutyl perfluorotetrahydrofuran. The solubility coefficient and the diffusivity of oxygen in the pure form of the fluorocarbons decreased with decreasing partial pressure of Oxygen (PO2), but the solubility coefficient and the diffusivity of carbon dioxide were independent of its partial pressure. The solubility and diffusion of oxygen in the emulsified form of the fluorocarbons followed the pattern expected from the behavior of oxygen in the pure fluorocarbon. The experimental results suggest that there exists a physical and/or chemical interaction between oxygen and the fluorocarbons, and this interaction is more pronounced at partial pressures below 150 mm Hg. Comparisons of the oxygen content in the fluorocarbon emulsions with that in whole blood show that at PO2 of 760 mm Hg, the oxygen content in the fluorocarbon emulsions is approximately one-half that in whole blood, but at PO2 of 50-150 mm Hg, the oxygen content in the emulsions decreases to values which are less than one-tenth that of whole blood.

Carbon Dioxide↗
PubMed1992

[Fluorocarbon emulsions as injectable oxygen carriers. Recent progress and perspectives].

Fluorocarbon emulsions are presently being developed to serve as injectable oxygen carriers (so-called "blood substitutes"). In this approach oxygen is simply dissolved in the liquid carrier and the amount of gas dissolved is proportional to its partial pressure. Increasing the O2-delivering capacity is therefore achieved more easily by increasing the oxygen content of the air breathed by the patient than by increasing the dose of fluorocarbon administered. The absence of a chemical bond between the gas and its carriers allows over 90% of the transported oxygen to be delivered. The fluorocarbon droplets act as oxygen carriers , and also appear to facilitate its diffusion. Chemically and biologically highly inert, fluorocarbons are excreted by exhalation without being metabolized. The first generation of emulsions, exemplified by Fluosol has only limited efficacy due to its low fluorocarbon content, low intravascular persistence and insufficient stability. It has to be stored and distributed frozen, then reconstituted prior to use. Fluosol has nevertheless been licensed by the Food and Drug Administration for use during high risk PTCA. The second generation of injectable fluorocarbon emulsions, exemplified by Oxygent is 4-5 times more concentrated and consequently more efficacious than Fluosol. Considerably more stable, this emulsion can be stored for over one year at 5-8 degrees C and is ready for use. The fluorocarbon used has a significantly shorter organ-retention time. The applications of the present emulsions are still limited by their short intravascular persistence, and are those for which prolonged efficacy is not required, which includes perioperative hemodilution, ischemia, cardioplegia, reperfusion, sensitization of tumors to radio- and chemotherapy, organ preservation and diagnosis. The efficacy of the new emulsions has been established in various animal models. The mild side-effects observed in Phase I clinical trials appear to result from a transient activation of the monocyte/macrophage system and to be suppressed prophylactically by cyclooxygenase inhibitors or corticosteroids. Research is presently oriented towards controlling intravascular persistence better, increasing emulsion stability further, minimizing side-effects and optimizing emulsion characteristics for specific indications.

Animals↗
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↗
PubMed1992

Overview of progress in the fluorocarbon approach to in vivo oxygen delivery.

The development of fluorocarbon-based oxygen carriers has experienced rapid progress over the past few years. Fluosol has been approved for use during percutaneous transluminal coronary angioplasty (PTCA) for high-risk patients. Its clinical evaluation is being pursued as an adjunct to cancer therapy and for treatment of myocardial infarction in conjunction with thrombolytic therapy. O2-delivery efficacy has been achieved with the development of the new highly concentrated (4 to 5 times more concentrated than Fluosol), fluid, emulsions of perfluorooctyl bromide (perflubron), trade-named Oxygen. The stability of fluorocarbon emulsions has also improved considerably and the new emulsions can be stored unfrozen and are ready for use. The side-effect profile of these emulsions has been characterized as being the normal response of the body's phagocytes to the injection of particles, a response that is considered physiological rather than pathological in nature; it involves some products of arachidonic acid metabolism and can be controlled pharmacologically. Means of further stabilizing fluorocarbon emulsions, involving molecular-diffusion-controlling additives or fluorinated surfactants, including mixed fluorocarbon-hydrocarbon compounds, have been devised. Increased control over in vivo particle recognition, intravascular persistence and side effects, and at adapting emulsion characteristics to specific applications, is being investigated. The range of therapeutic applications is expanding. The concentrated emulsions will be able to serve as a temporary red blood cell substitute in many situations. Acute normovolemic hemodilution with fluorocarbon emulsions, used in conjunction with homologous predonation and other blood-sparing techniques, should afford greater flexibility, increase the margin of safety, and reduce or alleviate the need for autologous blood transfusion during surgical procedures. Fluorocarbon applications in the cardiovascular field include use during PTCA, for cardioplegia and reperfusion, and the treatment of myocardial infarction. Significant tumor growth delay has been achieved when concentrated emulsions are used in conjunction with cancer radio- or chemotherapy. Liquid ventilation has potential as a unique treatment for the adult and infant respiratory distress syndromes and for drug delivery. The radiopaque and versatile perflubron can also be used in contrast agents for diagnosis with computed X-ray tomography, magnetic resonance imaging and ultrasound, allowing the early detection and staging of cancer. Other potential applications investigated include the treatment of cerebral ischemia, organ and limb preservation, use as a tamponade during retinal repair, etc.

Biotechnology↗
PubMed1992

Response of the rabbit lung as a criterion of safety for fluorocarbon breathing and blood substitutes.

From the first liquid breathing experiments until now, the lung, not surprisingly, has played a central role in the evolution of fluorocarbon blood substitutes. The first breathable fluorocarbon, a mixture of F-alkylfurans(FC75), bp 102 degrees C, while a poor solvent for the lung's lining and a good solvent for oxygen and carbon dioxide, proved to cause a characteristic gas/vapor microbubble embolism following intravenous administration as an emulsion. Higher boiling fluorocarbons, e.g. F-tributylamine (FC47), bp 174 degrees C, do not produce such gas-vapor emboli. However, intermediate boiling compounds such as F-decalin (PP5), bp 141 degrees C, produce lungs which, although they certainly appear not to contain microbubble emboli, do not collapse when the thorax is opened. Such hyperinflated non-collapsible lungs (HNCL) occur in the rabbit after the intravenous infusion of F-decalin emulsions as well as after the intratracheal infusion of F-decalin neat liquid. F-decalin induced HNCL retain their appearance and low specific gravity for many weeks, gradually returning toward normal after many months. F-methyl decalin, bp 165 degrees C, does not cause HNCL after intravascular or intratracheal administration. Fluorocarbons having boiling points between 140 degrees C and 165 degrees C are being tested in order to find a perfluorinate with the highest transpiration rate, and hence vapor pressure, compatible with an acceptable body dwell time. We have given fluorocarbons intratracheally to 75, intravenously to 221 and both intratracheally and intravenously to 8 rabbits. Free radical trapping agents, antineutrophil, antiinflammatory and other drugs have been administered without appreciable decrease of HNCL. Fluorocarbon critical solution temperature, lipid solubility, emulsifiability, and other physicochemical properties may mediate the pulmonary effect. One method of preventing and treating low dose F-decalin-induced HNCL in rabbits is described.

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↗
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↗
PubMed1991

Fluorocarbon-based oxygen carriers: new orientations.

Fluosol, a first, low-concentration fluorocarbon emulsion, was recently approved for oxygenating the myocardium during percutaneous transluminal coronary angioplasty. Improvements in fluorocarbon and emulsion technology have led to the development of significantly more stable, more efficient second-generation injectable O2 carriers. This progress extends the potential of fluorocarbons in medicine to new applications both in diagnostics and in therapeutics. Future objectives will aim at adjusting and optimizing the preparation's characteristics for each specific application. The emulsifier, or surfactant, which determines the external appearance of the fluorocarbon droplets, will play a key role in the mastery of emulsion properties. Extensive research efforts are therefore being directed toward the synthesis and evaluation of new families of surfactants or co-surfactants specifically designed for emulsifying fluorocarbons.

Blood Substitutes↗
PubMed1989

[The experimental study on long-term cardiac preservation: the efficacy of low-flow continuous perfusion with fluorocarbon].

We compared the effect of simple immersion and continuous perfusion on long-term cardiac preservation, and evaluated the effectiveness of perfusion with oxygenated fluorocarbon solution. The isolated rabbit hearts were preserved for 24 hours at 4 degrees C using the following five preservation techniques: (1) simple immersion with Collins M solution (Group I), (2) perfusion with oxygenated Collins M solution at a flow rate of 10 ml/hr (Group II), (3) perfusion with the same solution as in Group II at a flow rate of 20 ml/hr (Group III), (4) perfusion with oxygenated Collins M solution containing 10% fluorocarbon at a flow rate of 10 ml/hr (Group IV), (5) perfusion with the same solution as in Group IV at a flow rate of 20 ml/hr (Group V). The hearts of Group I showed a significant decrease of myocardial ATP and an increase of myocardial lactate during preservation compared to the hearts of perfusion groups. Assessment of isovolumic left ventricular function following 24-hour preservation using a support animal showed a significant decrease of Max dp/dt and increase of end-diastolic pressure in the hearts of Group I. Perfusion with fluorocarbon (Group IV and V) significantly increased oxygen consumption compared to Group II and III in association with minimum accumulation of myocardial lactate, indicating that aerobic metabolism during preservation is better maintained in the fluorocarbon-perfused hearts. Moreover, CPK release and myocardial water gain during preservation were significantly less, and left ventricular function following preservation was significantly better in these hearts. Increasing the flow rate from 10 ml/hr to 20 ml/hr resulted in sustained increase in perfusion pressure (1.80 +/- 0.53 to 3.70 +/- 0.34 mmHg) and myocardial water content (79.2 +/- 0.4 to 87.2 +/- 0.3%) during preservation in the hearts of Group III, but it did not further improve left ventricular function despite significant enhancement of myocardial oxygen uptake in both Group III and V. These results suggest that hypothermic low-flow continuous perfusion with oxygenated Collins M solution is superior to simple immersion with the same solution for long-term cardiac preservation, and that the addition of fluorocarbon to the perfusate enhances the efficacy of such a perfusion.

Animals↗
PubMed1979

Fluorocarbon aerosol propellants XII: Correlation of blood level of trichloromonofluoromethane to cardiovascular and respiratory responses in anesthetized dogs.

Anesthetized mongrel dogs were exposed to various concentrations of trichloromonofluoromethane. Before, during, and after the inhalation, arterial and venous blood samples were obtained for fluorocarbon analysis. After the cessation of fluorocarbon inhalation, a multiexponential decline for the blood was observed. This finding was similar to that of previous study in which the fluorocarbon was administered intravenously to unanesthetized dogs. The half-life calculated from the terminal phase was about 280 min, and the pseudodistribution equilibrium was reached about 100 min after dosing. Study of the relationship between blood fluorocarbon levels and effects on the respiration rate and arterial blood pressure indicates that the sites of these pharmacological activities are located in the blood or central compartment rather than in the peripheral compartment. The effect on the heart rate appears to be quite instantaneous after inhalation. These results might shed some light on the fast effect of the fluorocarbon propellants, which caused sudden deaths after inhalation of a large quantity.

Aerosol Propellants↗
PubMed1975

Cardiovascular effects of acute and chronic inhalations of fluorocarbon 12 in rabbits.

The effects of inhaling fluorocarbon 12, a common propellant in household aerosols, were studied in closed-chested rabbits. Inhalation of 10 or 20% fluorocarbon 12 produced a decline in cardiac output and a dose-related depression of peak left ventricular (LV) dP/dt without associated arrthythmias, hypoxemia or significant changes in LV end-diastolicpressue or heart rate. There was a small decline in LV systolic pressure without a significant drop in mean arterial pressure. Breathing fluorocarbon 12 for 30 minutes caused a decline in peak LV dP/dt, cardiac output, LV systolic pressure and mean arterial pressure which was present throughout the exposure period. The effects observed during acute fluorocarbon 12 exposure were not altered by previous chronic, intermittent exposure to 10% fluorocarbon 12.

Aerosol Propellants↗
PubMed1990

Influence of fluorocarbon emulsions on porphyrin-sensitised oxidation of histidine.

The influence of fluorocarbon emulsions on the efficiency of photosensitized oxidation of histidine in solution has been studied, using haematoporphyrin and dihaematoporphyrin derivatives as sensitisers. It is shown that the fluorocarbon emulsions at low concentrations efficiently disaggregate porphyrins, and thereby enhance photosensitised oxidation. The high solubility of oxygen in fluorocarbon emulsions maintains solution oxygen tension, optimising photooxidative damage. It is suggested that fluorocarbon emulsions might find a role in photodynamic therapy, both as carriers for sensitising dyes, and also to maintain tissue oxygenation in hypoxic regions of solid tumours.

Emulsions↗
PubMed1992

Development of highly fluid, concentrated and stable fluorocarbon emulsions for diagnosis and therapy.

A challenging aim in developing injectable fluorocarbon emulsions is to combine good flow characteristics (especially at low shear rates) with the high fluorocarbon concentration required for high oxygen delivery or effective contrast in imaging, long shelf life, and biological acceptability. A good balance of these sometimes conflicting objectives has been achieved with 90% w/v concentrated emulsions of various fluorocarbons, including the radiopaque oxygen carrier perfluorooctylbromide (PFOB, perflubron). The sterile emulsions have viscosities of about 20 cPs at a shear rate of 1 sec-1; the viscosity decreases rapidly with fluorocarbon concentration, and at 60% w/v the viscosity is less than that of human blood. The emulsions are suitable for injection as prepared, and are stable unfrozen for over a year.

Blood Substitutes↗
PubMed1992

[Current research on oxygen carriers for transfusion: hemoglobin solutions and fluorocarbon emulsions].

Although products currently under study are usually called "artificial blood" or "blood substitutes", it concerns only, for the moment, to achieve preparations able to carry and release oxygen to tissues while allowing also a temporary restoration of "blood" volume. The most advanced scopes are related to hemoglobin solutions and fluorocarbons emulsions. The limitations of free hemoglobin impose to modify it. The reestablishment of a normal, even reduced, affinity for oxygen is obtained by the fixation on hemoglobin of a 2,3-DPG substitute whose most known example is pyridoxal phosphate. The enhancement of vascular retention may be achieved by intramolecular cross-linking, intermolecular polymerization or covalent binding of hemoglobin on macromolecules. The two modifications of hemoglobin must be performed successively et numerous possibilities have been proposed. Bovine and recombinant hemoglobins are also promising. Originally and logically, fluorocarbons are synthetic compounds derived from hydrocarbons by an important or maximal substitution of hydrogen by fluorine. The physical properties of these molecules, impose, for transfusion, their emulsification in an aqueous physiological solution. They need an oxygen enriched atmosphere and their storage in tissues is often extended. At present, the most known emulsion is Fluosol DA, a mixture of perfluorodecalin and perfluorotripropylamine. It allowed to realize numerous researches and the proposal of the multiple possible employment for this category of oxygen carriers. The limitations of Fluosol DA led to fluorocarbons under investigation such as F dimethyl bicyclononanes, F methyladamantane, bis (F-butyl) ethene or F-octylbromide. The new hemoglobin solutions and fluorocarbons emulsions start to meet the requirements of potential users.

Blood Substitutes↗