Albumin, plasma separation

Prometheus In the meantime, the Prometheus method has been introduced. (97) Here, the plasma is separated out by an albumin-permeable filter and cleaned in a secondary circuit via an adsorber together with conventional high-flux haemodialysis. Direct contact between the albumin plasma and the adsorber helps to increase the efficiency of this method. 

Falkenhagen, D., Strobl, W., Vogt, G., Schrefl, A., Linsberger, L, Gerner, F.J., Schoenhofen, M. Fractionated plasma separation and adsorption system a novel system for blood purification to remove albumin bound substances. Artif Organs 1999 23 81-86... 

Albumin solution, human (PhEur 2005) Human albumin solution is an aqueous solution of protein obtained from plasma. Separation of the albumin is carried out under controlled conditions so that the final product contains not less than 95% albumin. Human albumin solution is prepared as a concentrated solution containing 150-250 g/L of total protein or as an isotonic solution containing 35-50 g/L of total protein. A suitable stabilizer against the effects of heat such as sodium caprylate (sodium octanoate) or N-acetyltryptophan or a combination of these two at a suitable concentration, may be added, but no antimicrobial preservative is added at any stage during preparation. The solution is passed through a bac-teria-retentive filter and distributed aseptically into sterile containers, which are then closed so as to prevent contamination. The solution in its final container is heated to 60 1.0°C and maintained at this temperature for not less than 10 hours. The containers are then incubated at 30-32°C for not less than 14 days or at 20-25°C for not less than 4 weeks and examined visually for evidence of microbial contamination. 

Krisper P, Haditsch B, Stauber R et al. In vivo quantification of hver dialysis Comparison of albumin dialysis and fractionated plasma separation. / Hepatol 2005 43 451-7. 

A method for the fractionation of plasma, allowing albumin, y-globulin, and fibrinogen to become available for clinical use, was developed during World War II (see also Fractionation, blood-plasma fractionation). A stainless steel blood cell separation bowl, developed in the early 1950s, was the earhest blood cell separator. A disposable polycarbonate version of the separation device, now known as the Haemonetics Latham bowl for its inventor, was first used to collect platelets from a blood donor in 1971. Another cell separation rotor was developed to faciUtate white cell collections. This donut-shaped rotor has evolved to the advanced separation chamber of the COBE Spectra apheresis machine. 

Bilirubin formed in peripheral tissues is transported to the hver by plasma albumin. The further metabolism of bihtubin occuts primarily in the hver. It can be divided into thtee processes (1) uptake of bilirubin by hver parenchymal cells, (2) conjugation of bilirubin with glucuronate in the endoplasmic reticulum, and (3) secretion of conjugated bilirubin into the bile. Each of these processes will be considered separately. 

Human albumin is a colloid used as a plasma volume expander and is not a source of nutrition. Albumin should be administered separately from PN because it may be incompatible and... 

Apart from its natural occurrence, Co may find its way into other proteins either adventitiously or deliberately. A study was undertaken where the blood, serum, and plasma of workers occupationally exposed to Co were analyzed for the element.1189 When separated by gel electrophoresis under denaturing conditions, the Co fractions in all blood, serum, and plasma samples showed a similar protein pattern. A variety of proteins of differing size were found to bind Co in fractions collected at pFl 5, whereas only hemoglobin was found in the pH 7 fractions. The conclusions were that in vivo Co is bound to plasma proteins, perhaps albumin and hemoglobin. 

The secretory vesicles have recently been discovered by Borregaard and co-workers (Sengelpv, Nielson Borregaard, 1992). These are very difficult to separate from the plasma membrane on density gradients. They possess latent alkaline phosphatase activity (i.e. subcellular fractions must be incubated with detergents such as Triton to release activity) and albumin, whilst the membranes contain CR1, CR3 and the fMet-Leu-Phe receptor. They are endocytic vesicles but can be rapidly translocated to the plasma membrane. 

Figure 11.1 Ultrastructure of the human lung alveolar barrier. The tissue specimen is obtained via lung resection surgery. (A) Section through a septal wall of an alveolus. The wall is lined by a thin cellular layer formed by alveolar epithelial type I cells (ATI). Connective tissues (ct) separate ATI cells from the capillary endothelium (en) within which an erythrocyte (er) and granulocyte (gc) can be seen. The minimal distance between the alveolar airspace (ai) and erythrocyte is about 800-900 nm. The endothelial nucleus is denoted as n. (B) Details of the lung alveolar epithelial and endothelial barriers. Numerous caveolae (arrows) are seen in the apical and basal plasma membranes of an ATI cell as well as endothelial cell (en) membranes. Caveolae may partake transport of some solutes (e.g., albumin). (C) ATII cells (ATII) are often localised in the comers of alveoli where septal walls branch off. (D) ATII cells are characterised by numerous multilamellar bodies (mlb) which contain components of surfactant. A mitochondrion is denoted as mi.

Figure 2.4. In vivo measurement of blood-brain barrier (BBB) permeability, (a) Internal carotid artery perfusion technique (i) in the rat. Other branches of the carotid artery are ligated or electrically coagulated (o, occipital artery p, pterygopalatine artery). The external carotid artery (e) is cannulated and the common carotid artery (c) ligated. Perfusion time may range from 15 s to 10 min, depending on the test substance. It is necessary to subtract the intravascular volume, Vo, from (apparent volume of distribution), to obtain true uptake values and this may be achieved by inclusion of a vascular marker in the perfusate, for example labelled albumin. Time-dependent analysis of results in estimates of the unidirectional brain influx constant Ki (pi min which is equivalent within certain constraints to the PS product. BBB permeability surface area product PS can be calculated from the increase in the apparent volume of distribution Vd over time. Capillary depletion, i.e. separation of the vascular elements from the homogenate by density centrifugation, can discriminate capillary uptake from transcytosis. (b) i.v. bolus kinetics. The PS product is calculated from the brain concentration at the sampling time, T, and the area under the plasma concentration-time curve, AUC.

Long-chain fatty acids are hydrophobic substances in plasma they occur in the esterified state or bound to protein (mainly albumin). As a consequence, long-chain fatty acids are not excreted into the urine and are measured either in the plasma or in erythrocytes, where they are part of the membrane. Erythrocyte levels of polyunsaturated fatty acids (PUFA) are fairly constant and may reliably reflect the longterm availability or deficiency of the essential fatty acids. A list of fatty acids that can be separated and analysed by GC is shown in Table 3.3.1. 

In the first dimension, 20 [tl plasma is separated by electrophoresis at 4°C in a 0.75% agarose gel using a 1 2 16 dilution of a barbital buffer. Bromophenol blue is added to a standard sample to visualize albumin in the native gel. The electrophoresis is stopped when the albumin/bromophenol blue marker has migrated 6 cm. Agarose gel strips containing the preseparated lipoproteins are then transferred to a 4-20% polyacrylamide gradient gel. Separation in the second dimension is performed at 40 mA for... 

Cass et al. [71] described a direct injection HPLC method, with column-switching, for the determination of omeprazole enantiomers in human plasma. A restricted access media of bovine serum albumin octyl column has been used in the first dimension for separation of the analyte from the biological matrix. The omeprazole enantiomers were eluted from the restricted access media column onto an amylose tris (3,5-dimethylphenylcarbamate) chiral column by the use of a columnswitching valve and the enantioseparation was performed using acetonitrile-water (60 40) as eluent. The analytes were detected by their UV absorbance at 302 nm. The validated method was applied to the analysis of the plasma samples obtained from 10 Brazilian volunteers who received a 40-mg oral dose of racemic omeprazole and was able to quantify the enantiomers of omeprazole in the clinical samples analyzed. 

Electrophoretic studies (G2, M2) have shown that both types of bilirubin are bound to albumin and sometimes a-globulin. Klatskin and Bungards (K6) found that this binding occurs between pH 6 and pH 9 and that below pH 5 separation occurs almost completely with respect to bilirubin but only partially with the conjugated pigment. This suggests that bilirubin and conjugated bilirubin are attached in different ways to plasma proteins. 

In a follow-up study, the same authors examined the applicability of the same device for relevant protein samples and investigated the main contributions to band broadening [82]. As a consequence of the small depth of the beds, zone spreading caused by Joule heating was shown to be negligible (see Sect. 3.1.1). Cross fields of up to 100 V/cm were applied for the separation of human serum albumin, ribonuclease A and bradykinin. The feasibility of fraction collection was demonstrated with four collected fractions of a whole rat plasma sample. Off-line analysis of these four isolated fractions by CE indicated the separation of serum albumins and globulins. 

After 4 1/2 hours 1.0 ml. blood contained 1.0 x 105 counts/min. Electrophoretic separation of plasma showed 77% of Cu associated with albumin fractions, 1 to 3% in each a-globulin fraction (total 10%), 1 to 3% in each -globulin fraction (total 10%), and about 3% in y-globulins... 

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