Metabolism INDEX

Except as an index of respiration, carbon dioxide is seldom considered in fermentations but plays important roles. Its participation in carbonate equilibria affects pH removal of carbon dioxide by photosynthesis can force the pH above 10 in dense, well-illuminated algal cultures. Several biochemical reactions involve carbon dioxide, so their kinetics and equilibrium concentrations are dependent on gas concentrations, and metabolic rates of associated reactions may also change. Attempts to increase oxygen transfer rates by elevating pressure to get more driving force sometimes encounter poor process performance that might oe attributed to excessive dissolved carbon dioxide. 

The PMV index can be determined when the activity (metabolic rate) and the clothing (thermal resistance) are estimated and the following environmental parameters are measured air temperature, mean radiant temperature, relative air velocity, and partial water vapor pressure (see ISO EN 7726). 

Determinant A chemical metabolic product of the change in the body s chemistry caused by exposure to a pollutant. The level of determinant is measured in a biological sample collected from the exposed worker, and compared to the biological exposure index (BEI). Determination The analytical measurement of a pollutant. 

Ferritin is another protein that is important in the metabolism of iron. Under normal conditions, it stores iron that can be called upon for use as conditions require. In conditions of excess iron (eg, hemochromatosis), body stores of iron are greatly increased and much more ferritin is present in the tissues, such as the liver and spleen. Ferritin contains approximately 23% iron, and apoferritin (the protein moiety free of iron) has a molecular mass of approximately 440 kDa. Ferritin is composed of 24 subunits of 18.5 kDa, which surround in a micellar form some 3000-4500 ferric atoms. Normally, there is a little ferritin in human plasma. However, in patients with excess iron, the amount of ferritin in plasma is markedly elevated. The amount of ferritin in plasma can be conveniently measured by a sensitive and specific radioimmunoassay and serves as an index of body iron stores. 

In terms of pharmacokinetics, many host factors, such as the route of administration, the metabolism, the catabolism and clearance will considerably determine the anti neoplastic success of a drug. One major difficulty with the clinical effectiveness of chemotherapy of neoplastic diseases is the requirement that it kill malignant tumor cells at doses that allow cells in the patient s vital organs to survive so that the recovery can occur. In other words, it is to obtain a reasonably safe therapeutic index favoring introduction into clinical practice. 

Cardiac output also varies with age. Expressed as cardiac index, it rapidly rises to a peak of more than 4 1/min/m2 at age 10 and then steadily declines to about 2.4 1/min/m2 at the age of 80. This decrease in cardiac output is a function of overall metabolic activity and therefore indicative of declining activity with age. 

It has been suggested (Insam and Haselwandter 1989 Anderson and Domsch 1990) that the metabolic quotient can be used as an index of ecosystem development. As an ecosystem reaches maturity, selection pressure towards efficient use of available resources results in a larger microbial biomass with a lower metabolic quotient. Nonetheless, Wardle and Ghani (1995) concluded that qC02 can be insensitive to disturbance and ecosystem development, fails to distinguish between effects of disturbance and stress and does not decline predictably in response to ecosystem development wherever stress increases along successional gradients. 

Metabolic quotient Variable often in the range of 2-40pg C02-C mg-1 biomass day-1 Basal respiration per unit of microbial biomass C. Provides a useful measure of the efficiency with which microbes are using substrate C. Often used as an index of the degree of microbial stress. 

Cardiac index and blood pressure must be sufficient to ensure adequate organ perfusion, as assessed by alert mental status, creatinine clearance sufficient to prevent metabolic azotemic complications, hepatic function adequate to maintain synthetic and excretory functions, a stable heart rate and rhythm, absence of ongoing myocardial ischemia or infarction, skeletal muscle and skin blood flow sufficient to prevent ischemic injury, and normal arterial pH (7.34 to 7.47) with a normal serum lactate concentration. These goals are most often achieved with a cardiac index greater than 2.2 L/min/m2, a mean arterial blood pressure greater than 60 mm Hg, and PAOP of 25 mm Hg or greater. 

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