Effect of Exchange Transfusion on Bilirubin Binding

The bilirubin titration point-the lowest bilirubin concentration at which loosely bound bilirubin could be demonstrated by Sephadex gel filtration-was determined in samples collected before, during, and on completion of 17 exchange transfusions as well as in the discarded and donor blood. The bilirubin titration point expressed either as bilirubin concentration or as bilirubin/albumin molar ratio failed to be increased by the exchange transfusion and, in each case at the end of the procedure, the titration point was below the expected level, assuming that the donor albumin was going to retain its binding properties in the infant's circulation. The bilirubin titration point was also depressed in the discarded blood, and the depression was inversely related to the amount of bilirubin removed by the exchange transfusion (expressed as mg/kg of body weight/mg of initial bilirubin concentration). These results are interpreted as an indication that interfering substances are responsible for the decreased binding of bilirubin in newborn, particularly preterm, infants. In practical terms the criteria for a repeat exchange transfusion should be the same as for the initial one, as no change in the bilirubin binding properties of the serum is likely to occur following exchange transfusion.

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Sephadex Bilirubin Binding Test Yet To Be Shown Valid?

PEDIATRICS ◽

10.1542/peds.62.5.856 ◽

1978 ◽

Vol 62 (5) ◽

pp. 856-856

Author(s):

Ronald L. Poland

Keyword(s):

Exchange Transfusion ◽

Newborn Infants ◽

Diverse Population ◽

Binding Properties ◽

Bilirubin Binding

The article by Valaes and Hyte (Pediatrics 59:881, June 1977) states that the "criteria for a repeat exchange transfusion should be the same as for the initial one, as no change in the bilirubin binding properties of the serum is likely to occur following exchange transfusion." They base their conclusion on bilirubin titration points obtained by Sephadex gel filtrations before, during, and after exchange transfusion in a diverse population of newborn infants, most of whom received adult albumin in one form or another prior to exchange transfusion.

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Antithrombin III Affinity for Thrombin, Trypsin and α-Chymotrypsin

10.1055/s-0039-1684680 ◽

1979 ◽

Author(s):

E. Marciniak

Keyword(s):

Enzyme Inhibitor ◽

Binding Capacity ◽

Gel Filtration ◽

Factor Xa ◽

Molar Ratio ◽

Antigenic Determinants ◽

Binding Properties ◽

Protein Fragments ◽

Multiple Protein ◽

At Iii

The relative affinity of human AT III for thrombin, trypsin and α-chymotrypsin was evaluated tn reactions proceeding in the molar excess of inhibitor, to reflect more closely natural conditions occurring in plasma. Residual AT III was titrated as total factor Xa-binding capacity independent of the velocity of inhibition. The decrease in binding properties of purified AT III reacting with thrombin or trypsin was consistent with formation of enzyme-inhibitor complexes at 1:1 molar ratio and was associated with a partial obliteration of antigenic determinants. Purified α1-trypsin inhibitor competed with AT III but not for thrombin. α-chymotrypsin caused an excessive loss ot AT III binding properties; once the enzyme-inhibitor ratio exceeded 1:5 proteolysis of AT III occurred with formation of multiple protein fragments evident in gel filtration in fibrinogen-depleted human plasma where the overall binding capacity for both trypsin and thrombin exceeded that of AT III, a marked difference was seen in the rate of AT III utilization by each of these enzymes. Every μM of trypsin gradually added utilized on the average only 2% of AT III capacity, whereas the amount of thrombin capable of binding 1 μM of purified AT III obliterated of AT III capacity in plasma. Neutralization of thrombin proceeded after AT III was totally depleted. These results contribute to the notion that AT III is the primary inhibitor of thrombin with an unique affinitv for this enzyme in blood.

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ADMINISTRATION OF ALBUMIN IN THE MANAGEMENT OF HYPERBILIRUBINEMIA BY EXCHANGE TRANSFUSIONS

PEDIATRICS ◽

10.1542/peds.30.4.613 ◽

1962 ◽

Vol 30 (4) ◽

pp. 613-621

Author(s):

Gerard B. Odell ◽

Sanford N. Cohen ◽

Ellen H. Gordes

Keyword(s):

Body Weight ◽

Adipose Tissue ◽

Birth Weight ◽

Comparative Study ◽

Exchange Transfusion ◽

Serum Levels ◽

The Body ◽

Bilirubin Concentration ◽

Albumin Administration ◽

Total Body

A comparative study was done to evaluate the effect of the administration of albumin on the removal of bilirubin by exchange transfusion. The amounts of bilirubin removed by simple exchange were similar when the pre-exchange concentrations in serum were alike. The administration of one gram of albumin per kilogram of body weight 1 to 2 hours prior to the procedure resulted in the removal by exchange transfusion of an average of 41% more bilirubin per kilogram of birth weight. The amount of bilirubin removed from the infants given albumin did vary from infant to infant in spite of similar pre-albumin bilirubin concentrations in serum. This was interpreted to represent variation in the total body bilirubin content, even when serum levels are alike. The amount of bilirubin removed per kilogram of birth weight was not found to be related to the etiology of the hyperbilirubinemia, the infant's age, or to the body weight at the time of the exchange. The albumin administration was associated with an increase in bilirubin concentration in serum and a decrease in capillary hematocrit value. Adipose tissue did not seem to be a major source of the additional bilirubin removed.

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MICRO-DETERMINATION OF CORTICOSTEROIDS IN OVINE PERIPHERAL PLASMA: EFFECTS OF VENIPUNCTURE, CORTICOTROPHIN, INSULIN AND GLUCOSE

Journal of Endocrinology ◽

10.1677/joe.0.0440387 ◽

1969 ◽

Vol 44 (3) ◽

pp. 387-403 ◽

Cited By ~ 95

Author(s):

J. M. BASSETT ◽

N. T. HINKS

Keyword(s):

Body Weight ◽

Sodium Succinate ◽

Gel Filtration ◽

Binding Properties ◽

Peripheral Plasma ◽

Plasma Effects ◽

Corticosteroid Binding Globulin ◽

Steroid Binding ◽

Sensitive Method

SUMMARY A sensitive method for the determination of corticosteroids in 0·1 ml. or less of ovine plasma is described. The method uses the steroid-binding properties of corticosteroid-binding globulin (CBG) and gel filtration on small columns of Sephadex G-25 (fine) at 4° for separation of CBG-bound and free steroids. Cortisol was found to be the predominant corticosteroid in ovine plasma and accounts for about 90% of the value determined by this method. The corticosteroid concentration in peripheral plasma of unstressed sheep was in the range 0·1–1·0 μg./100 ml. In untrained animals, venipuncture increased corticosteroid concentration substantially; training reduced the effect. An infusion of cortisol sodium succinate (100 μg. cortisol/min.) increased the plasma corticosteroid level to 9·5 ± 0·49 μg./100 ml. Intravenous infusion of the synthetic adrenocorticotrophic preparation Synacthen at rates of 10 and 20 μg./hr. for 2 hr. increased peripheral corticosteroid concentrations to 8 μg./100 ml. Single i.v. injections of 0·2–0·8 μg. Synacthen also significantly increased peripheral corticosteroid concentrations 7–15 min. later. The injection of 0·05 and 0·1 μg. Synacthen significantly increased the corticosteroid concentration too, but the increase was not significantly greater than that produced by the injection of acidified saline diluent alone. Injection of insulin (0·25 unit/kg. body weight, i.v.) caused a fivefold increase in the corticosteroid concentration 30–60 min. later, in both adult sheep and lambs. Glucose (0·25 g./kg. body weight, i.v.) had no effect on corticosteroid concentration.

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Characterization of glycoconjugates of human gastrointestinal mucosa by lectins. II. Lectin binding to the isolated glycoproteins of normal and malignant gastric mucosa.

Journal of Histochemistry & Cytochemistry ◽

10.1177/32.7.6429236 ◽

1984 ◽

Vol 32 (7) ◽

pp. 690-696 ◽

Cited By ~ 15

Author(s):

J Fischer ◽

G Uhlenbruck ◽

P J Klein ◽

M Vierbuchen ◽

R Fischer

Keyword(s):

Molecular Weight ◽

Gastric Mucosa ◽

High Molecular Weight ◽

Lectin Binding ◽

Gel Filtration ◽

Molar Ratio ◽

Gastric Cancer Cells ◽

Tissue Sections ◽

Gradient Gel Electrophoresis ◽

Triton X

Using affinity chromatography on HPA-, PNA-, Con A, and WGA-agarose columns only a part (10-30%) of the high molecular weight mucous glycoproteins could be isolated from the Triton X-100 solubilized components of normal as well as carcinomatous gastric mucosa. The main part of the mucus was not bound by the lectins, which corresponds to our earlier lectin histochemical observations on paraffin-embedded tissue sections. The lectin-bound mucous glycoproteins had a relatively lower molecular weight, ranging from about 250-1,000 kilodaltons, as indicated by polyacrylamide gradient gel electrophoresis and by gel filtration on Biogel A 1.5 m column. In gas chromatographic analysis the molar ratio of aminohexoses to galactose was found to be much higher (3:1) in the lectin-bound mucous substances than in the whole high molecular weight mucus (1:1). This finding indicates that lectins have a higher affinity to the hexosamine rich components of mucus, which may be special forms of mucous glycoprotein molecules or the incompletely glycosylated core and backbone regions of the oligosaccharide chains of mucus. Extremely high hexosamine values (10:1) were found in the PNA isolated mucus of gastric adenocarcinoma. Since it is known that PNA binds to the terminal disaccharide, beta-galactose-(1-3)-N-acetylgalactosamine, which is localized at the reducing end of the oligosaccharide chains of mucus, it is highly probable that the elongation of the oligosaccharide side chains is disturbed in gastric cancer cells.

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Control of Jaundice in Preterm Newborns by an Inhibitor of Bilirubin Production: Studies With Tin-Mesoporphyrin

PEDIATRICS ◽

10.1542/peds.93.1.1 ◽

1994 ◽

Vol 93 (1) ◽

pp. 1-11 ◽

Cited By ~ 6

Author(s):

Timos Valaes ◽

Sophia Petmezaki ◽

Claudia Henschke ◽

George S. Drummond ◽

Attallah Kappas

Keyword(s):

Body Weight ◽

Heme Oxygenase ◽

Enzyme Inhibitors ◽

Treatment Modalities ◽

Bile Pigment ◽

Bilirubin Concentration ◽

Production Studies ◽

Plasma Bilirubin ◽

Preterm Newborns

Background. Studies in vitro, in animal models, and in adult and newborn humans have demonstrated that certain tin(Sn)-porphyrins that competitively inhibit the activity of heme oxygenase, the rate-limiting enzyme in heme catabolism, reduce production of bilirubin and can thereby substantially diminish plasma levels of the bile pigment. Objectives. To assess the effectiveness of increasing doses of the heme oxygenase inhibitor, Sn-mesoporphyrin (SnMP), in moderating the development of significant hyperbilirubinemia and thus the requirements for phototherapy in preterm newborns. Methods. In five randomized, blinded, placebo-controlled trials, SnMP in increasing doses from 1 µmol to 6 µmol/kg body weight was administered intramuscularly in the first 24 hours of life in preterm newborns of 210 to 251 days gestational age. "Special blue" lamps (Phillips F20T12/BB) were used for phototherapy in newborns exceeding a predetermined plasma bilirubin concentration, irrespective of study group. Results. A total of 517 newborns were randomized in the five trials carried out sequentially over a 4-year period. SnMP in a dose-related manner significantly ameliorated the course of hyperbilirubinemia in the treated newborns Of all gestational ages. With a SnMP dose of 6 µmol/kg body weight, the mean peak incremental plasma bilirubin concentration was reduced by 41% and the phototherapy requirements were decreased by 76% compared to control subjects. Erythema observed in a few SnMP-treated newborns who required phototherapy was mild, transient, and without sequelae. No other untoward effects were observed during hospitalization or at a follow-up at post-term age of 3 and 18 months. Conclusions. SnMP, by inhibiting the production of bilirubin, substantially moderates the development of hyperbilirubinemia in preterm newborns. This compound and similarly acting enzyme inhibitors merit further clinical study as agents for controlling neonatal hyperbilirubinemia, particularly in neonatal populations for whom other treatment modalities are not available.

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Purification and characterization of prostate-specific antigen (PSA) complexed to alpha 1-antichymotrypsin: potential reference material for international standardization of PSA immunoassays

Clinical Chemistry ◽

10.1093/clinchem/41.9.1273 ◽

1995 ◽

Vol 41 (9) ◽

pp. 1273-1282 ◽

Cited By ~ 42

Author(s):

Z Chen ◽

A Prestigiacomo ◽

T A Stamey

Keyword(s):

Molecular Mass ◽

Prostate Specific Antigen ◽

Specific Antigen ◽

Gel Filtration ◽

Exchange Chromatography ◽

Molar Ratio ◽

Free Psa ◽

Apparent Homogeneity ◽

International Standardization

Abstract We describe for the first time a protocol to purify to apparent homogeneity an in vitro-prepared complex of prostate-specific antigen (PSA) and alpha 1-antichymotrypsin (ACT) by using a combination of gel filtration and ion-exchange chromatography. The purity of the PSA-ACT complex was confirmed by gel electrophoresis and Western blot. The PSA-ACT complex was stable in the pH range 6.0 to 7.8; it was also stable in various matrices, temperatures, and high concentrations of salt. Purification of the PSA-ACT complex was highly reproducible. An absorptivity of 0.99 L x g-1 x cm-1 at 280 nm was assigned to the PSA-ACT complex, based on amino acid analysis. Because PSA and ACT bind in a 1:1 molar ratio, we determined the molecular mass of the PSA-ACT complex as the mass encoded by the cDNA of ACT (plus 26% carbohydrate) plus the molecular mass of PSA (28,430 Da), which totals 89,280 Da. Using this material, we made two common calibrators, one of 100% PSA-ACT complex and one of 90% PSA-ACT complex plus 10% free PSA by volume (90:10 calibrator). Substitution of these calibrators for the manufacturers' calibrators in nine commercial immunoassays substantially reduced differences between immunoassays, especially for serum PSA values between 4 and 10 micrograms/L. The 90:10 calibrator is recommended as a universal calibrator for international standardization of PSA immunoassays.

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