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Biomedical subjects

K D Fisher

Publications and source records attributed to K D Fisher.

11 recordsLinked to original sources
PubMed1986

Influence of space flight on red blood cells.

Losses of red blood cell mass (RCM) averaging 10-15% have been observed consistently in astronauts after space flight; postflight recovery of RCM requires 4-6 wk. Although apparently not harmful to the health and effectiveness of crews during uncomplicated flights, decreased RCM could compromise health and performance in the event of illness, injury, or partial malfunction of the life support system. Whether the loss of RCM would worsen or stabilize in missions longer than 7 months is unknown. As a biological response, it is a significant, predictable reaction whose etiology, biological mechanisms, and potential operational significance are inadequately defined. Weightlessness is probably the primary cause; however, contributory factors may include hypokinesia/hypodynamia, bone loss, muscle atrophy, altered hemodynamics, stress, and metabolic disturbances. Space medical specialists consider other possible influences such as hypoxia, hypobaria, radiation, toxic contaminants, and launch and reentry accelerations as less likely factors. Because the data base on loss of RCM is insufficient for the National Aeronautics and Space Administration's space medical responsibilities, the Life Sciences Research Office ad hoc Working Group on Space Anemia suggested research approaches ranging form fundamental topics such as utilization of erythropoietin and oxygen in target organs and cell-cell interactions, through possible splenic and vascular dysfunctions, metabolic disturbances, and inhibitors of erythropoiesis, to methodology and models.

Body Weight↗
PubMed1984

Space sickness.

Explore the source record for details and available documents.

Aerospace Medicine↗
PubMed1982

A successful peer review program for regulatory decisions.

A unique peer review program for Federal agencies has been operating since 1962 to provide opinions of leading investigators for sponsors in various fields of the life sciences. The most notable study has recently been completed for the U.S. Food and Drug Administration on the Generally Recognized as Safe (GRAS) food ingredients. Over 400 substances were evaluated by a Select Committee over a 10-year period and evaluative reports were submitted to the regulatory agency. Based in part on these reports made available for public comments, the FDA has been able to develop decisions for appropriate actions on the health aspects of these food ingredients. A comprehensive report on the work of the Select Committee on GRAS substances will be published in the archival literature.

Legislation, Food↗
PubMed1982

History and current status of infant formulas.

Formulas that approximate the composition of human milk are widely used as the sole source of nutrients for infants during the first months of life. Such formulas contain milk, soy, or meal proteins, or protein hydrolysates together with those forms of fat carbohydrate, vitamins, and minerals shown to be bioavailable to the infant. Legislation concerning nutrient composition and quality assurance of products labeled as infant formulas has been enacted by Congress. Governmental and industrial standards also help to assure microbiological safety and stability. Problems of nutrient composition and adverse reactions have occurred during the evolution and development of infant formulas. Problems concerning nutrient deficiency are now almost unknown, but adverse reactions of individuals to specific formula ingredients continue. Accurate information on composition and related nutritional properties of infant formulas is essential for their effective use and for the avoidance of undesirable complications.

Animals↗
PubMedDate not supplied

The need for special foods and sugar substitutes by individuals with diabetes mellitus.

The need for special dietary products marketed for use by individuals with diabetes mellitus and the safety and efficacy of certain nutritive sweetener substitutes for sucrose are reviewed. Special foods for individuals with diabetes mellitus are not necessary to achieve the dietary objectives recommended by leading United States and European authorities. They can be achieved conveniently and at minimum expense through enlightened choices of commonly available food items. At present, specific and unique characteristics of food products with special therapeutic properties for diets of diabetic individuals cannot be delineated or defined on rational nutritional grounds. Such terms as "diet", "dietetic", and "diabetic" on food labels have no uniform meaning for consumers, and diabetologists have observed that patients tend to consume such foods without regard to their energy content. Some consumers regard the reduced-calorie and low-calorie prepared food products as convenient in diets for weight reduction and diabetes although their use in dietary management of diabetes has no therapeutic basis other than weight reduction and maintenance. When fed as pure substances to fasted subjects, the nonglucose carbohydrate nutritive sweeteners, fructose, xylitol, and sorbitol, are absorbed relatively slowly and produce less postprandial hyperglycemia and insulin response than sucrose or glucose. Adequate studies of their long-term effectiveness when ingested as part of mixed meals have not been conducted. Although these sucrose substitutes are generally considered safe, the significance of recent information on possible carcinogenicity of oral xylitol in long-term feeding studies has not been fully evaluated. In view of the lack of certain essential information on the long-term effectiveness of various diets in preventing or mitigating the chronic debilitating complication of diabetes, suggestions for future research are included.

Blood Glucose↗