Isotope fractionation by plants and animals: implications for nutrition research.

The isotopic compositions of animal tissues, minerals, and fluids reflect those of ingested food and water and inhaled gases. This relationship is illustrated by a review of data pertaining to five light elements of biological interest (carbon, nitrogen, hydrogen, oxygen, and sulphur). Processes affecting the isotopic composition of inorganic compounds in reservoirs are summarized, and isotope fractionation during transfer of elements from these inorganic reservoirs through progressive trophic levels of food webs is discussed. Variability of delta values within and among individuals, populations, and species of plants and animals is attributed to at least six factors: locality, dietary selectivity, biochemical composition of food, isotope effects in metabolic processes, turnover rates, and stress. Features of a variety of terrestrial and aquatic ecosystems are used to illustrate basic concepts. Future research should seek to clarify specific mechanisms affecting delta values during the transfer of elements through food webs.

[Importance of surgical gowns and drapes as barriers for prevention of postoperative infections]. / L'importanza di camici e teli come barriera per prevenire le infezioni post-operatorie.

The gown and drape barrier system has been shown to be an important factor in the prevention of wound infection. Performance differences between disposable and reusable materials as influencing wound infections were demonstrated. A disposable spun-bonded olefin gown and drape system significantly reduced the postoperative wound infection rate. No therapeutic benefit in clean surgical operations was observed for either the preoperative antibiotic group of local wound irrigation group. Factors indicating populations at higher risks for wound infection include age, sex and those requiring long and an emergency type operations. Special attention should be given to the infection prone groups. Unless factors, such as percentage of type of operation, emergency nature, age and sex, are weighed, a comparison of wound infections between hospitals is invalid.

The importance of gown and drape barriers in the prevention of wound infection.

The gown and drape barrier system has been shown to be an important factor in the prevention of wound infection. Performance differences between disposable and reusable materials as influencing wound infections were demonstrated. A disposable spun-bonded olefin gown and drape system significantly reduced the postoperative wound infection rate. No therapeutic benefit in the preoperative antibiotic group or localwound irrigation group. Factors indicating populations at higher risks for wound infection include age, sex and those requiring long and an emergency type operations. Special attention should be given to the infection prone groups. Unless factors, such as percentage of types of operation, emergency nature, age and sex, are weighed, a comparison of wound infections between hospitals is invalid.