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Biomedical subjects

C Becker

Publications and source records attributed to C Becker.

At least 127 records · Page 7Linked to original sources
PubMed1975

Attributable risk, population attributable risk, and population attributable fraction of death associated with hypertension in a biracial population.

In 1961, blood pressure was measured in the 40-69-year-old segment of the population of Evans County, Georgia. Mortality was monitored for up to ten years. The relationship found between hypertension and mortality is characterized in this report by four parameters: attributable risk, prevalence, population attributable risk, and population attributable fraction. Attributable risk of death, a measure of the over-all impact of hypertension on those in each race-sex group with hypertension, is high in white males, black males, and black females, and is lowest in white females. Population attributable risk, a measure of the impact of hypertension on each entire race-sex group, is highest in black males and females due to the high prevalence of hypertension in blacks. It is somewhat lower in white males and lowest in white females. The fraction of all deaths attributable to hypertension (population attributable fraction) is highest in black females and lower in the other three groups. The population attributable fraction (ranging from 0.26 to 0.54 for systolic hypertension) is of such magnitude that if the 50% reduction in mortality achieved in the Veteran Administration Cooperative Study could be repeated in the general population, life expectancy after 40 years of age could be substantially increased.

Adult↗
PubMed1975

Emulsions of perfluorinated solvents for intravascular gas transport.

During the past several years we have progressed from the use of perfluorinated substances, which were good gas solvents but often produced unexpected physiological reactions, to a point where emulsions of pure perfluorinated substances can be made in a reproducible way. A standardized method of making emulsions has now been developed. The physical properties of the perfluorinated substances needed to make useful emulsions have been defined. Specifically, perfluorinated substances having vapor pressures above about 40 torr must be avoided as they produce pulmonary gas embolism; also lower boiling components having vapor pressures above about 40 torr must be excluded. The relationship between chemical structure and several physiological and pharmacological effects has been delineated. Perfluorinated substances containing only carbon and fluorine, or those containing carbon, fluorine, and either bromine or iodine have reasonably short dwell times in the liver. Perfluorinated iodo- and bromo-compounds dissolve oxygen and are radiopaque. Present iodo-perfluorinates are unstable in the presence of light. Perfluorodecalin can enter and leave the liver without changing the liver's ultrastructure. Both egg phospholipid and Pluronic F68 are useful in making perfluorodecalin emulsions. Perfluorodimethyladamantane makes a fine-particle stable emulsion. There is a bright future for perfluorinated substances in a number of areas of research in biology and medicine.

Animals↗
PubMed1973

Perfluorocarbons having a short dwell time in the liver.

Perfluorinated organic liquids are useful as high capacity oxygen and carbon dioxide solvents. After intravenous infusion most of these perfluorinated emulsions are deposited in the liver and spleen in a matter of days, where they remain for the lifetime of the animal. Hence, while they may be useful as isolated organ perfusion media their value as artificial blood is limited. A family of perfluorocarbons has now been discovered, which, although deposited in the liver after circulation in the blood, leave the liver to be excreted via the lungs and skin in a matter of days without apparent harmn to the animal.

Animals↗