Biological value 768 INDEX

Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indexes," Proceedings of American Conference of Government Hygienists, Cincinnati, Ohio, 1996. 

Biological exposure index (BEI) Reference values developed by ACGHl as guidelines for the evaluation of potential health hazards. 

Documentation of the Threshold Eimit Values and Biological Exposure Index, 5th ed., American Conference of Governmental Industrial Hygienists, Cincinnati, Ohio, 1986. 

For styrene, the default intraspecies UF of 10 was reduced to 3 in the calculation of the RfC value, because the lower 95% limit of the exposure extrapolation for a NOAEL in a human cross-sectional study was used and the biologic exposure index had been shown to account for variation in pharmacokinetic and physiologic measures, such as the alveolar ventilation rate (EPA 1993). 

Atrial natriuretic peptide Adenosine triphosphate Concentration in arterial blood minus that in venous blood Branched chain amino acid Branched chain kcto acid Body mass index Basai metabolic rate Biological value Cyclic AMF Cholecystokinin Cholcsteryl ester Complementary DNA Coenzyme A Cocn yme A... 

Studies on the predictive value of renal changes other than microproteinuria are needed to assess the validity of this biological exposure index. It is interesting to note that suggestive evidence of excess of neurotoxic complaints has been shown in Cd smelter workers from the Balen plant before signs of Cd-induced microproteinuria occurred [133]. 

Leung, H. W., and Paustenbach, D. J. (1988). Application of pharmacokinetics to derive biological exposure indexes from threshold limit values. Am Ind Hyg Assoc J 49, 445-450. 

The amount of tetrachloroethylene metabolized varies among different ethnic human populations. Seiji et al. (1989) reported that the relationship between total urinary trichloro-compounds and the concentration of tetrachloroethylene in breath air was 0.063 mg TCA/L per ppm tetrachloroethylene in Chinese workers, while the value was 0.7 mg TCA/L per ppm tetrachloroethylene in Japanese woikers. Jang et al. (1993) determined that the biological exposure index in Korean workers exposed to 50 ppm tetrachloroethylene was 1.6 mg tetrachloroethylene/L in blood and 2.9 mg TCA/L in urine compared to the ACGIH values of 1 mg tetrachloroethylene/L in blood and 7 mg TCA/L in urine for exposure to 50 ppm (ACGIH 1991). 

Volume ( 150 mL) of conducting airways where no gas exchange occurs Biological Exposure Index. Reference value developed by ACGIH Ratio of the vapor concentration in blood and in air at 37°C 15 breaths per minute at rest, increases with physical exertion First segment of the airways, which includes the trachea, bronchi, terminal bronchioles... 

Biological Exposure Index. Reference value developed by ACGIH... 

In view of the low protein content of the diet in some countries, it is of paramount importance to be able to evaluate the biological efficiency of a given protein. To express this property mathematically for each protein, one can determine the essential amino acid index, which is the geometric mean of the ratio of the amino acid in the test protein versus the amino acid in a standard protein most efficiently utilized (egg protein). On the basis of the amino acid index, an equation was developed which expresses the biological value of the protein. 

Oser, B.L. An integrated essential amino acid index for predicting the biological value of proteins. In Protein and amino acid nutrition 66. (Albanese, A.A., ed.). New York Academic Press 1959... 

Biological value is stated as the proportion of the nitrogen intake that is actually retained and takes account of endogenous urinary and faecal nitrogen, whereas chemical score and the essential amino acid index are based on the proportion of the main limiting amino acid of the protein in relation to that in a standard protein. 

Proteins have different biological availabilities in the human body and a number of methods have been introduced to evaluate and measure protein utilisation and retention. Two types of measurements are used to estimate protein quality biological assays and chemical analysis. The most common measures of protein quality included Biological Value (BV), Protein Efficiency Ratio (PER), Net Protein Utilisation (NPU), Amino Acid Score (AAS also known as chemical score, CS), Essential Amino Acid Index (EAAl) and Protein Digestibility Corrected Amino Acids Score (PDCAAS), amongst other procedures and modifications. 

The blood glucose level induced by carbohydrates in food can be measured by the glycaemic index (GI), which evaluates the biological value of dietary carbohydrates and is a measure of the effects of food carbohydrates on the blood glucose level. It is defined... 

In USA, the Ameriean Conference of Governmental Industrial Hygienists (ACGIH, 1330 Kemper Meadows Drive, Cincinnati, OH 45240-1634, USA) publishes each year the Treshold limit values for chemical substances and physical agents and biological exposure index , which are frequently used in other countries that do not have their own regulations. 

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