Hemolysis preparation

In another study, the carrier protein was replaced by an enzyme compatible solid-phase resin (PEGA), and enzyme-catalyzed cyclization was used to probe substrate specificity. This study demonstrated also that oxo-esters are tolerated as substrates for TE domains, and then-preparation in library format served as an excellent tool for substrate specificity studies, as well as for preparation of cyclized peptides. Figure 13.11 shows how the TycA TE showed selectivity for only residues 1 and 9 (colored in red), and changes at all other residues were tolerated [42]. Hydrogen bonding interactions are shown in green. Several compounds made from this series were shown to demonstrate improved therapeutic indices (with respect to hemolysis) while retaining antimicrobial activity. 

It was soon found that tyrothricin causes severe hemolysis when administered parenterally and was destroyed when given orally. The antibiotic complex or individual components are effective topically and are used in various cream, ointment, lotion and solution preparations alone or in combination with other antibiotics or topical steroids3. 

The best sources of Hp preparations are sera from patients with advanced cancer and/or with severe infections without coexisting abnormal hemolysis, i.e., in subjects with high-electrophoretic a2-values. Sera of the same Hp type may be pooled and stored in the frozen state with no loss of its HbBC, Sera containing Hb visible with the naked eye should not be added to the pools. Ascitic fluid from patients with infections or cancer, but without abdominal hemorrhage, is a convenient source. 

AmB solubilized in DMSO and dispersed in PBS provoked 50% hemolysis of human erythrocytes at 3.5mg/L of AmB. Fungizone and AmB prepared by the same process as LC-AmB but without lipids were slightly less toxic (Hbso 5mg/L). All the lipid formulations caused less than 50% hemolysis at the highest concentration tested (lOOmg/L). 

WEC serum requires special preparation and needs to be free of hemolysis. The Harland sernm listed above has been prepared according to these specifications. 

One such distribution phenomenon can occur as a result of hemolysis of the sample. Preparation of the TDM sample involves centrifugation to separate the cells and platelets from the plasma. If the sample is hemolyzed, then the centrifugation may not adequately separate cell fragments from the plasma. That can result in an increase in the apparent concentration of drug in plasma. 

Experiment. Prepare hemolyzed plasma or serum by spiking hemolyzed whole blood into nonhemolyzed plasma at low QC level. Hemolyzed blood for these experiments can be prepared by freezing, thawing and centrifuging whole blood. Three levels of hemolysis are used 0 % (100 % normal plasma/serum), 0.5 % of above (99.5 % normal plasma/serum), and 2 % of above (98 % normal plasma/ serum). Analyze six (6) replicates for each group. Compare the mean instrument response of the 0.5 % or 2 % hemolysis test samples to that of the 0.0 % control group. 

Such relationships can be useful in designing synthetic membranes having properties similar to natural systems. For example, Equation 4 correlates the change in resistance caused by alcohols on potassium ion permeability of black lipid membrane (BLM) prepared from the lipid of sheep erythrocytes. The rather large negative intercept of Equation 4 indicates that three times the concentration of isolipophilic alcohol is needed to change the resistance of the BLM as is needed to cause hemolysis. Although the two processes are quite different, the role of hydrophobic forces in each can be compared. 

The most encompassing test of an excipient s safety is the systemic safety of the material because many of the routes of administration ultimately result in at least some minor systemic exposure. Numerous studies with the parent CDs have shown that their parenteral toxicity is observed primarily as renal and cytotoxicity (hemolysis and tissue irritation). These toxicities were the driving force for the preparation of new CD derivatives, many of which exhibit improved parenteral safety. 

Irritation, and hemolysis are primary considerations when choosing a cosolvent for parenteral preparations. Concentration and route of administration are important factors that determine the incidence and severity of local reactions. 

In preparation for bone marrow transplantation, autologous hemopoietic stem cells are normally frozen in liquid nitrogen after harvesting. However, a cryoprotective agent is required, and dimethylsulfoxide is normally used. During and immediately after stem cell infusion, many adverse effects, which may be severe or life-threatening, have been reported. They include hypotension and hjrpertension, anaphylactic reactions, and cardiac and respiratory failure, all possibly due to dimethylsulfoxide, hemolysis induced by cryopreservation and thawing, and fluid overload. 

In vitro tests have shown that oleic acid causes rupture of red blood cells (hemolysis), and intravenous injection or ingestion of a large quantity of oleic acid can therefore be harmful. The effects of oleic acid on alveolar and buccal epithelial cells in vitro have also been studied the in vitro and in vivo effects of oleic acid on rat skin have been reported. Oleic acid is a moderate skin irritant it should not be used in eye preparations. 

The biological activity of various preparations of both toxins can be easily checked using rabbit red blood cells. Normally, a red blood cell suspension (2.5 % final concentration) in PBS (50 mM phosphate, pH 7, supplemented with 4 % sodium citrate), which can be stored for 3-4 days at 4 °C, was mixed with various toxin dilutions (final volume 55 xl). After 40 min at 37 °C hemolysis is monitored spectrophotomet-rically at 412 nm in 30 [aI of the supernatant, diluted with 1 ml of distilled water. Total hemolysis is determined after the addition of SDS (0.2 %) which gives an extinction of about 1.2. The dilution of toxin hemolyzing 50 % of the red blood cells is taken as the number of hemolytic units per milliliter of the undiluted toxin solution (Lind et ai, 1987 Ahnert-Hilger et ai, 1989a,b). 

D. Specimen List type of specimens that can be used and recommended volume and minimum volume. Indicate conditions that render the specimen unacceptable, such as hemolysis or lipemia. List patient preparation procedures. Provide instruction for specimen handling before testing. 

The use of surfactants in parenteral products is limited by their potent side-effects. All surfactants, especially those that are ionic may cause hemolysis. Anaphylactoid reactions have been noted, particularly in association with the destruction of lymphocytes, resulting in histamine release. Phospholipids are generally well-tolerated, and are frequently used in the preparation of emulsions. Nonionic surfactants such as Cremophor EL and polysorbate 80 (Tween 80) are known to cause hypersensitivity reactions (Eschalier et al., 1988 Mounier et al., 1995 Theis et al., 1995 Munoz et al., 1998 Volcheck and Van Dellen, 1998), including hypotension, largely via histamine release mechanisms. Because of potential side-effects, it is now traditional to pretreat the patient with an antihistamine and possibly a corticosteroid (e.g., prednisone) before administration of formulations that contain Cremophor EL. 

Indications for red cell transfusions include (1) acute exacerbation of baseline anemia, such as aplastic crisis if the anemia is severe, hepatic or splenic sequestration, or severe hemolysis (2) severe vaso-occlusive episodes, such as ACS, stroke, or acute multiorgan failure and (3) preparation for procedures that require the use of general anesthesia or ionic contrast. Other patients in whom transfusions may be useful include patients with complicated obstetric problems, refractory leg ulcers, or refractory and protracted painful episodes or severe... 

The normal lactate concentration in blood is between 1.2 and 2.7 mmol/1. For accurate lactate determination hemolysis of the sample is required to account for the (low) lactate content of erythrocytes. On the other hand, the glycolytic reactions in the sample have to be efficiently and rapidly inhibited in order to avoid lactate formation. Therefore the best-suited sample material is deproteinized blood however, the time period inevitably required for its preparation prevents rapid lactate assay. That is why the study of blood lactate sensors focuses not only on the sensor itself but also on the rapid pretreatment of blood samples. 

Melamine derivatives bearing thiourea and thiouronium ions have been prepared as flavin receptors <04BCJ569>. Hemolysis and cytotoxicity activities of six dendrimers based on ... 

---