Proteins plasma concentration

The drug is highly bound to albumin (approximately 90%) [91]. Protein binding is concentration dependent and decreases at high valproate concentration [91]. Free fraction plasma protein concentration increases from approximately 10% at 40 pg/mL to 18.5% at 130 pg/mL [91], Protein binding decreased markedly in elderly [92], in patients with renal failure [92], and in liver diseases [93]. 

Total plasma protein concentration was determined by the buiret method (16) after correction of plasma hemoglobin which was determined by the cyanmethemoglobin method (15). Plasma osmolality was measured by a Wescor model 5100 vapor pressure osmometer. 

Statistical Methods. Means of treatment groups for plasma retention of BSP, plasma osmolality, total plasma protein concentration and urine flow rates were compared by students t test for independent sample means (17). Plasma enzyme activity data were converted to a quantal form and analyzed by the Fischer Exact Probability Test (18). Values greater than 2 standard deviations (P < 0.05) from the control value were chosen to indicate a positive response in treated fish. 

Mobilization of edemas (A) In edema there is swelling of tissues due to accumulation of fluid, chiefly in the extracellular (interstitial) space. When a diuretic is given, increased renal excretion of Na and H2O causes a reduction in plasma volume with hemoconcentra-tion. As a result, plasma protein concentration rises along with oncotic pressure. As the latter operates to attract water, fluid will shift from interstitium into the capillary bed. The fluid content of tissues thus falls and the edemas recede. The decrease in plasma volume and interstitial volume means a diminution of the extracellular fluid volume (EFV). Depending on the condition, use is made of thiazides, loop diuretics, aldosterone antagonists, and osmotic diuretics. 

Nephrotic syndrome is characterized by proteinuria and edema due to some form of glomerulonephritis. The resulting fall in plasma protein concentration decreases vascular volume, which leads to diminished renal blood flow. This in turn causes secondary aldosteronism characterized by Na and water retention and K+ depletion. Rigid control of dietary Na is essential. Therapy of the nephrotic syndrome using a thiazide (possibly with a K -sparing diuretic) to control the secondary aldosteronism, is a useful initial approach to treatment Since nephrotic edema is frequently more difficult to control than cardiac edema, it may be necessary to switch to a loop diuretic (and spironolactone) to obtain adequate diuresis. 

The plasma-protein concentration is a species-dependent variable, and the proportions and types of proteins may also vary. The concentration may vary from about 20 g L-1 in certain... 

The reverse flux of fluid from the interstitial to the vascular space (14) is caused by increased interstitial fluid pressure (12) and increased plasma protein concentration (oncotic pressure), hyperosmotemia, or both depending upon the intensity (above or below 50 -peak capacity) and duration of the exercise. Increased interstitial hydrostatic pressure and increased plasma osmotic pressures retard the fluid shift from plasma to the interstitium. Equilibrium is reached when interstitial pressure balances capillary filtration pressure (24). After cessation of exercise, restitution of plasma volume takes 40-60 minutes (21,22) unless significant dehydration is present. The immediate post-exercise hyperosmotemia, the relative hyperproteinemia, and the reduction in systemic blood pressure contribute to the restoration of plasma volume. The reduction in blood pressure, which produces a fall in local hydrostatic pressure within the capillaries of the previously active muscle, is probably the single most important factor. 

Variation in plasma protein concentrations can occur secondary to decreased albumin concentrations associated with hepatic cirrhosis, and nephrotic syndrome (Table 2). Increased (apadd glycoprotein concentrations are associated with the stress response to disease states such as myocardial infarction, inflammatory disease, and postsurgically. " A more relevant problem... 

Plasma protein concentration Acute febrile infections Malnutrition Advanced age Familial deficiencies ... 

Plasma protein concentration Dehydration Acute myocardial infarction Alcoholism ... 

The therapeutic index of meclofenamic acid in horses is not well defined. For example, ponies treated with meclofenamic acid at the recommended dosage (2.2mg/kg) for 10 days had decreased plasma protein concentrations but no... 

Although lactate can be measured directly, its plasma concentration can be accurately predicted by the anion gap in horses with normal plasma protein concentrations (Constable et al 1998). The... 

Under these conditions the plasma protein concentration decreases. Sodium is an emetic intake of excess sodium leads to nausea and vomiting. The accidental substitution of table salt for sugar has resulted in sodium poisoning in infants. These infants experienced increased body temperature, muscle twitching, and convulsions in some cases, their kidneys were damaged. Sodium compounds with high pH values in solution (e.g., sodium hydroxide) are extremely corrosive to the skin and mucous membranes. 

The variability associated with drug absorption from the gastrointestinal tract can be overcome by using a parenteral preparation (dosage form). It should preferably be administered either by intravenous infusion or slow intravenous injection to avoid circulatory overload. Intraosseous administration is a useful alternative to intravenous injection of some antimicrobial agents (e.g. sodium ampicillin or amoxycillin, cefotaxime, ceftriaxone, gentamicin or amikacin sulphate) in neonatal foals (Fig. 7.1) (Golenz et al, 1994) and puppies (Lavy et al, 1995). This particularly applies when the neonate is in a state of septic shock and/or dehydration. Total plasma protein concentration is an inaccurate index of hydration status unless monitored (repeatedly measured) and interpreted in conjunction with packed cell volume (PCV). 

Fluid retention caused by nicotine causes a mild decrease in the plasma protein concentration but without demonstrable effect on the calcium concentration or on the activity of serum enzymes. The plasma urate concentration is less in smokers than in nonsmokers, probably as a result of lessened intake of food by smokers. Both the serum urea and creatinine concentrations tend to be less in smokers than in nonsmokers. 

Within a few minutes of an infant s birth, fluid passes from the blood vessels into the extravascular spaces. This fluid is similar to plasma except that the fluid lost from the intravascular space contains no protein. Consequently the plasma protein concentration increases. The serum activities of several eu2ymes, including CK, GGT, and AST, are high at birth, but the increase of alanine aminotransferase (ALT) activity is less than that of other enzymes. 

Ambient temperature affects the composition of body fluids. Acute exposure to heat causes the plasma volume to expand by an influx of interstitial fluid into the intravascular space, and by reduction of glomerular filtration. The. plasma protein concentration may decrease by up to 10%. Sweating may cause salt and water loss, but usually there are no changes in the plasma sodium and chloride concentrations. Plasma potassium concentration may decrease by as much as 10% as potassium is taken up by the cells. If sweating is extensive, hemoconcentration rather than hemodilution may occur. 

The protein-rich fluid lost from the intravascular space after trauma is replaced with protein-poor fluid from the interstitial spaces. Subsequently, this is replaced by a fluid similar in composition to plasma. Transfusion of whole blood or plasma raises the plasma protein concentration the amount... 

TABLE 20-5 Effects of Steroid Hormones on Plasma Protein Concentrations... 

Polyclonal antibodies are widely used in clinical laboratories for the measurement of plasma protein concentrations. However, immunoassays are often sensitive to the nature of the antibody used. The development of polyclonal antibodies is affected by several factors, such as the purity and dose of the antigen used, the species of host animal, and the immunization procedure. Monoclonal antibodies are viewed as a viable alternative to alleviate these problems. However, the expression of particular epitopes varies with the hpoprotein particles and among individuals in addition, the apohpoproteins themselves are polymorphic in nature. Therefore the use of a single monoclonal antibody might not detect a particular variant. If a monoclonal antibody is used in the determination of an apohpoprotein, it should he directed to an epitope that is expressed on all polymorphic forms of that particular apoprotein. Furthermore, the epitope should be equally reactive to the antibodies regardless of which hpoprotein class contains it. Alternatively a mixture of monoclonal antibodies directed at different epitopes of the apohpoprotein may also be used. Such mixtures are referred to as panmonoclonal antibodies. 

Plasma Protein Buffer System and Plasma Base Excess The buffer value (p) of the nonbicarbonate buffers of plasma is about 7.7 mmol/L at pH 7.40 and a normal plasma protein concentration of 72 g/L. Proteins, especially albumin, account for the greatest portion (95%) of the nonbicarbonate buffer value of the plasma. The most important buffer groups of proteins in the physiological pH range are the imidazole groups of histidines (pimolecule contains 16 histidines. 

Although complex, these calculations have demonstrated a very good correlation (both linearity and value agreement) with equilibrium dialysis measurements and are considered a reliable indicator of free testosterone. The reader is directed to other references for further details on this method, Conditions resulting in abnormal plasma protein concentrations, such as nephrotic syndrome, cirrhosis, and pregnancy require adjustments in the assumption for albumin concentration. 

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