Serum function

Most historical medium formulations were supplemented with serum, tissue extracts, or other humoral fluids. As these supplements were vital to the success of the technique they undoubtedly supplied nutritional factors that were absent from the nutrient media. Although serum fractions have been characterized, total biochemical definition is a complex challenge, as it has been reported that serum contains more than 1000 proteins (Lambert and Birch, 1985). Complete characterization must identify cytokines and transport and attachment factors, as well as address other serum functions, such as pH buffering capacity, toxin inactivation, and protease activity. Such unspecified growth promotional and nutritional serum properties are perceived by users as quality. Other contributors to quality, inherent to serum supplementation, include lot-to-lot variability, availability, cost, and absence of adventitious contaminants. 

Description of Method. Creatine is an organic acid found in muscle tissue that supplies energy for muscle contractions. One of its metabolic products is creatinine, which is excreted in urine. Because the concentration of creatinine in urine and serum is an important indication of renal function, rapid methods for its analysis are clinically important. In this method the rate of reaction between creatinine and picrate in an alkaline medium is used to determine the concentration of creatinine in urine. Under the conditions of the analysis, the reaction is first-order in picrate, creatinine, and hydroxide. 

Separation media, with bimodal chemistry, are generally designed for the complete separation of complex samples, such as blood plasma serum, that typically contain molecules differing in properties such as size, charge, and polarity. The major principle of bifunctional separation relies on the pore size and functional difference in the media. For example, a polymer bead with hydrophilic large pores and hydrophobic small pores will not interact with and retain large molecules such as proteins, but will interact with and retain small molecules such as drugs and metabolites. 

LIPOPROTEINS. Blood plasma lipoproteins are prominent examples of the class of proteins conjugated with lipid. The plasma lipoproteins function primarily in the transport of lipids to sites of active membrane synthesis. Serum levels of low density lipoproteins (LDLs) are often used as a clinical index of susceptibility to vascular disease. 

Agents acting in the proximal tubule are seldom used to treat hypertension. Treatment is usually initiated with a thiazide-type diuretic. Chlorthalidone and indapamide are structurally different from thiazides but are functionally related. If renal function is severely impaired (i.e., serum creatinine above 2.5 mg/dl), a loop diuretic is needed. A potassium-sparing agent may be given with the diuretic to reduce the likelihood of hypokalemia. 

The parathyroid glands in FHH are reset to maintain a higher than normal serum calcium concentration owing to impaired suppression of PTH release in the face of hypercalcemia (e.g., resistance to CaQ+) (Fig. 2). Similarly the kidneys show a reduced calciuric response to hypercalcemia, which contributes to the hypercalcemia by promoting inappropriately reabsorption of calcium. Mouse models of FHH and NSHPT result from targeted inactivation of one or both CaR alleles, respectively [1,3]. These animals have provided valuable insights into the alterations in tissue function resulting from loss of the receptor. 

Intestinal absorption of digoxin is less complete compared to digitoxin. In order to improve absorption, acetylated- and methylated-digoxin derivates were developed. Digitoxin is metabolised in hepatic microsomal enzymes and can be cleared independently from renal function. The therapeutical serum level of digoxin is 0.5-2.0 ng/ml and 10-35 ng/ml of digitoxin. Steady state plateau of therapeutic plasma concentrations is reached after 4-5 half-life-times using standard daily doses [5]. 

Total drug clearance is the sum of nonrenal clearance and renal clearance (Clren). According to the MDRD-2 formula, the estimated GFR (eGFR) is a function of serum creatinine (SCr in mg/dl) and age (Age in years). It has the unit ml/min per 1.73 mA2. 

In bone, three proteins have been described which are vitamin K-dependent, osteocalcin (bone Gla protein), matrix Gla protein (MGP), and protein S. Osteocalcin is synthetized by osteoclasts, regulated by the active form of vitamin D, calcitriol. Its capacity to bind calcium needs a vitamin K-dependent y-carboxylation of three glutamic acid residues. The calcium binding capacity of osteocalcin indicates a possible role in bone mineralization, but its exact function is still unclear. However, it is widely used as a serum marker for bone mineralization. Protein S, mainly a coagulant, is also vitamin-K dependent and synthesized in the liver. Children with... 

INEFFECTIVE TISSUE PERFUSION RENAL The patient taking an aminoglycoside is at risk for nephrotoxicity. The nurse measures and records the intake and output and notifies the primary health care provider if the output is less than 750 ml/day. It is important to keep a record of the fluid intake and output as well as a daily weight to assess hydration and renal function. The nurse encourages fluid intake to 2000 ml/day (if the patient s condition permits). Any changes in the intake and output ratio or in the appearance of the urine may indicate nephrotoxicity. The nurse reports these types of changes to the primary health care provider promptly. The primary health care provider may order daily laboratory tests (ie, serum creatinine and blood urea nitrogen [BUN]) to monitor renal function. The nurse reports any elevation in the creatinine or BUN level to tiie primary health care provider because an elevation may indicate renal dysfunction. 

More than half of the patients receiving this drug by the parenteral route experience some adverse reaction. Severe and sometimes life-threatening reactions include leukopenia (low white blood cell count), hypoglycemia (low blood sugar), thrombocytopenia (low platelet count), and hypotension (low blood pressure). Moderate or less severe reactions include changes in some laboratory tests, such as the serum creatinine and liver function tests. Other adverse reactions include anxiety, headache, hypotension, chills, nausea, and anorexia Aerosol administration may result in fatigue a metallic taste in the mouth, shortness of breath, and anorexia... 

It is important to monitor closely serum blood levels of chloramphenicol, particularly in patients with impaired liver or kidney function or when administering chloramphenicol with other drugs metabolized by the liver. Blood concentration levels exceeding 25 mcg/mL increase the risk of the patient developing bone marrow depression. 

Administration may result in nausea, vomiting, diarrhea, rash, anemia, leukopenia, and thrombocytopenia Signs of renal impairment include elevated blood urea nitrogen (BUN) and serum creatinine levels. Periodic renal function tests are usually performed during therapy. 

RISK FOR INEFFECTIVE TISSUE PERFUSION RENAL When the patient is taking a drag tiiat is potentially toxic to die kidneys, die nurse must carefully monitor fluid intake and output. In some instances, die nurse may need to perform hourly measurements of die urinary output. Periodic laboratory tests are usually ordered to monitor the patient s response to therapy and to detect toxic drag reactions. Seram creatinine levels and BUN levels are checked frequentiy during the course of therapy to monitor kidney function. If the BUN exceeds 40 mg dL or if the serum creatinine level exceeds 3 mg cIL, the primary health care provider may discontinue the drug therapy or reduce the dosage until renal function improves. 

A serious and potentially fatal adverse reaction to tolcapone ishepatic injury. Regular blood testing to monitor liver function is usually prescribed. The phys dan may order testing of serum transaminase levels at frequent intervals(eg, every 2 weeks for the first year and every 8 weeks thereafter). Treatment is discontinued if the ALT (SOFT) exceeds the upper normal limit or sgns or symptoms of liver failure develop. 

Serum levels (digoxin) may be ordered daily during the period of digitalization and periodically during maintenance therapy. Periodic electrocardiograms, serum electrolytes, hepatic and renal function tests, and other laboratory studies also may be ordered. 

The primary health care provider may also order laboratory and diagnostic tests, renal and hepatic function tests, complete blood count, serum enzymes, and serum electrolytes. The nurse reviews these test results before the first dose is given and reports any abnormalities to the primary health care provider. The patient is usually placed on a cardiac monitor before aiitiarrhytiuiric drug therapy is initiated. The primary health care provider may order an ECG to provide baseline data for comparison during therapy. 

When administering the HMG-CoA reductase inhibitors and the fibric acid derivatives, the nurse monitors the patient s fiver function by obtaining serum transaminase levels before the drug regimen is started, at 6 and 12 weeks, then periodically thereafter because of the possibility of liver dysfunction with the drugs. If aspartate aminotransferase (AST) levels increase to three times normal, the primary care provider in notified immediately because the HMG-CoA reductase inhibitor therapy may be discontinued. 

When these drugs are given to the female patient with inoperable breast carcinoma, tire nurse evaluates the patient s current status (physical, emotional, and nutritional) carefully and records tire finding in tire patient s chart. Problem areas, such as pain, any limitation of motion, and the ability to participate in tire activities of daily living, are carefully evaluated and recorded in tiie patient s record. The nurse takes and records vital signs and weight. Baseline laboratory tests may include a complete blood count, hepatic function tests, serum electrolytes, and serum and urinary calcium levels. The nurse reviews these tests and notes any abnormalities. 

If the male or female patient is being treated for a malignancy, the nurse enters in the patient s record a general evaluation of the patient s physical and mental status. The primary health care provider may also order laboratory tests, such as serum electrolytes and liver function tests. 

Older adults may need a reduced dosage of magnesium because of decreased renal function. The nurse should closely monitor serum magnesium levels when magnesium is administered to older adults... 

There are other substrates for the E. coli Met(0) peptide reductase, one of which is Met(0)-a-l-PI. The native protein is the major serum elastase inhibitor that functions by forming a binary complex with elastase which inhibits its activity. Met(0)-a-l-PI, on the other hand, which can be formed by treatment of the protein with TV-chlorosuccinimide, cannot form a complex with elastase and therefore is not able to inhibit elastase activity117,118. Table 6 shows, however, that when Met(0)-a-l-PI is incubated in the presence of Met(0)-peptide reductase and dithiothreitol the protein regains its ability to form a complex with elastase and inhibit elastase activity119. Similar to results found with Met(0)-L12 reduced thioredoxin could replace the dithiothreitol as reductant in the enzymatic reaction. 

There is a second type of cholinesterase called butyrylcholinesterase, pseudocholinesterase, or cholinesterase. This enzyme is present in some nonneural cells in the central and peripheral nervous systems as well as in plasma and serum, the liver, and other organs. Its physiologic function is not known, but is hypothesized to be the hydrolysis of esters ingested from plants (Lefkowitz et al. 1996). Plasma cholinesterases are also inhibited by organophosphate compounds through irreversible binding this binding can act as a detoxification mechanism as it affords some protection to acetylcholinesterase in the nervous system (Parkinson 1996 Taylor 1996). 

Table 3 shows the classical values calculating for Mark-Houwink parameters, a and k for temperature. These studies on M-H parameters are usually carried out at a given temperature, obtaining a consistent result but in a very limited range of temperature (for gelatin Pouradier Venet 1954 and Bohidar 1998 Monkos for serum proteins 1996, 1997, 1999, 2000, 2004 and 2005). This value shows a clear functionality between these parameters and temperature. 

Monkos K. 1996. Viscosity of bovine serum albumin aqueous solutions as a function of temperature and concentration. International Journal of Biological Macromolecules 18, 61-68. 

---