CLINICAL USES OF SEROMUCOID ESTIMATION

Interactions between glycosaminoglycans and proteins, with particular reference to a new technique for isolating serum glycoproteins

1. Chondroitin sulphate-serum protein complexes (A, B and C), successively precipitated by adding chondroitin sulphate to serum at three arbitrary descending pH values (5.2, 4.3 and 3.1), were dissociated at pH 6.7 and chromatographed on DEAE-Sephadex, when the liberated serum proteins were simultaneously freed of chondroitin sulphate and separated into five fractions. Evidence that serum proteins were precipitated as a result of electrostatic interactions with dissociated carboxylate groups on the glycosaminoglycan is presented. 2. Serum proteins (fraction G), unable to form complexes with chondroitin sulphate, contained 4.4% of sialic acid and accounted for 4 and 26% of the total protein and protein-bound sialic acid in serum respectively. This fraction interacted electrostatically with chondroitin sulphate only when rendered more basic by removal of sialic acid residues with neuraminidase. The heat stability, solubility properties and high carbohydrate content of fraction G classified it as a seromucoid fraction. 3. Fraction G contained several glycoprotein and hexuronic acid-containing fractions, including a hitherto undetected brown-pigmented high-molecular-weight serum component, which migrated in starch gel between the origin and Salpha(2)-globulin and contained 3.1 and 4.1% of sialic acid and hexuronic acid respectively. 4. Glycosaminoglycan-protein interactions are discussed in relation to protein fractionation. By prior removal of less acidic proteins by these interactions, a new technique is available for isolating serum seromucoids in higher yields and under milder conditions than existing methods.

Acute-phase reactant proteins and carcinoembryonic antigen in cancer of the colon and rectum

One hundred and twenty-eight patients bearing primary malignancies of the large bowel were studied to ascertain the value of acute-phase reactant proteins (serum protein hexose, ceruloplasmin, transferrin, alpha-1-antitrypsin, seromucoid and haptoglobin) either alone or in conjunction with carcinoembryonic antigen to accurately reflect the disease status of patients both before and after resection of their large bowel malignancy. The results indicate that acute-phase reactant proteins have a higher diagnostic rate for the presence of malignancy than does CEA. Estimation of the serum protein hexose alone is of greater diagnostic value than a combination of acute-phase reactant proteins. Furthermore, serum protein hexose and CEA are complementary and when combined will reflect the presence of malignancy in a greater number of patients than either one alone. Following resection of primary large bowel cancer, acute-phase reactant proteins are as accurate as CEA in evaluating the disease-free status of patients and furthermore when combined with CEA increased the predictive value for the detection of patients with recurrent disease.

Serum alpha-1-acid glycoprotein as an index of dissemination in breast cancer

Assay of the serum alpha-1-acid glycoprotein (SAGP) produced by the liver in response to many disease states is shown to reflect prognosis and monitor progress in patients with early, recurrent and disseminated breast cancer. Eighteen of 26 patients with localized breast cancer and positive bone scans had elevated SAGP when first seen, but within 5 months of treatment 5 further patients with positive bone scans developed an elevated SAGP. Furthermore, an initially abnormal SAGP level became normal within 5 months in 5 of 6 patients with negative bone scans. While elevated SAGP in breast cancer correlates with positive bone scans, a series of normal values may indicate patients without early haematogenous dissemination of their disease.

Effects of infection on selected clinical and biochemical parameters in dogs

Five month old male beagles injected i.p. with a washed 18-hr culture of Salmonella typhimurium 1 × 10⁹ organisms/kg. responded clinically with a marked depression, anorexia, and a febrile response 12 hr following infection. Animals allowed to live beyond 36 hr showed a decrease in febrile response. Although they still refused food 36 hr following infection, they appeared more alert by 60 hr post-infection. Changes at necropsy were minimal and histologic findings consistent with Salmonella infection were found in both liver and spleen. In animals infected 60 hr liver microabscesses and circumscribed foci of reticuloendothelial cell hyperplasia in the spleen indicated that the animals were responding favourably by mounting a defence against the infection.

As a result of infection there was an outpouring of band neutrophils resulting in an increase in the absolute numbers of circulating white blood cells. Associated with the neutrophilia was an early lymphopenia and eosinopenia.

The total free amino acids were depressed in serum and increased in the liver at all time periods observed, but the degree of change as well as the specific amino acids affected varied; however, alterations in concentration of amino acids in serum of animals infected with Salmonella were similar to those observed in dogs infected with the virus of canine distemper. In both viral and bacterial infected dogs serum phenylalanine was increased and tyrosine remained the same or decreased, resulting in a significant alteration in the phenylalanine/tyrosine (P/T) ratio.

As with distemper infected dogs, an increase of the alpha-2 fraction of serum proteins was detected at 36 hr following infection. There was a decrease in the monosome peak and a corresponding increase in the polysome fraction of the liver post-mitochondrial supernatant preparation associated with infection. The significance of this change in the liver polysome profile following infection is not yet understood.