A new serum type system in man--the lp system.

Publisher Summary This chapter discusses the practical methods for plasma lipoprotein analysis Changes in the concentration and sometimes in the nature of the plasma lipoproteins occur in a variety of diseases The pioneering work of Gofman and his colleagues in the early 1950s was responsible for much of the knowledge of these complex proteins that is now available Their techniques of analytical ultracentrifugation were, and still remain, the primary standard for lipoprotein analysis These methods are available in very few medical centers; however, excluding access to them by most of the laboratories where the interest and availability of patients or subjects for investigation are the greatest Recent simplifications and improvements of other analytical methods have made these a partial replacement for the analytical ultracentrifuge, and newer methods have proved their value Techniques of protein chemistry and immunology have added a new dimension to lipoprotein analysis —that of specific recognition and quantitation of the protein moieties

Practical methods for plasma lipoprotein analysis.

Patients who receive large numbers of transfusions for anemia and other causes may develop precipitins in their blood. These precipitins may react in agar gel double diffusion experiments with specific human serum lipoprotein found in the blood of other individuals. Since these precipitins were found only in patients who had received transfusions they were thought to be antibodies against serum lipoproteins which developed in the patients as a result of the repeated transfusions. The precipitin is referred to as an isoprecipitin since it develops against a specificity found in an individual from the same species. The antilipoprotein isoprecipitin1,2developed in approximately 30% of 47 patients with thalassemia who had received transfusions. Isoprecipitins also developed in smaller number of transfused patients with other diseases. All precipitins stained with sudan black, a dye specific for lipid. Immunoelectrophoretic and ultracentrifugal studies showed that the protein with which the isoprecipitins reacted was a

A New Antigen in Leukemia Sera

Excerpt We have previously reported the presence of an isoantigen of human sera, rare or absent in normal U. S. and northern European populations but relatively common in patients with leukemia (1,...

A serum antigen (Australia antigen) in Down's syndrome, leukemia, and hepatitis.

1. The N-acetyl-beta-glucosaminidase of human spleen has been separated by gel electrophoresis into two components, an acidic form A and a basic form B. 2. The two forms are readily separated on DEAE-cellulose and have been concentrated 50-fold and sevenfold respectively. 3. They show similar K(m) values towards 4-methylumbelliferyl N-acetyl-beta-d-glucosaminide, and have the same pH optima when compared in citrate, phosphate or acetate buffers. They are inhibited to a similar extent by acetate, heparin, N-acetylgalactosaminolactone, N-acetyl-beta-d-galactosamine and N-acetyl-beta-d-glucosamine. Specificity for C-4 orientation is not absolute and p-nitrophenyl beta-galactosaminide is also hydrolysed but at a rate only 11.6% of that for the corresponding glucosaminide. 4. N-Acetyl-beta-glucosaminidase B is stable over a wider pH range than is N-acetyl-beta-glucosaminidase A, and is less easily denatured by heat. 5. Tissue fractionation indicates that both the A and B forms are present in the lysosomal fraction, whereas the supernatant contains the A form only. 6. Evidence is presented to indicate that the A form contains a number of sialic acid residues.

N-Acetyl-β-glucosaminidases in human spleen

BOYER1 noted that blood serum from normal adults produced in starch-gel zymograms one or two major zones of phosphatase activity between the transferrin and the haptoglobin 1–1 regions. Occasionally there was also a faint band near the origin. Similar patterns were later reported by other investigators2–5.

Differential action of neuraminidase on human serum alkaline phosphatases.

Antigen polymorphism of a low-density beta-lipoprotein. Allotypy in human serum.

SOME human tumours and tumour-derived cell lines are capable of producing ‘eutopic’ peptide hormones and other proteins that are normally synthesised by the tissue from which the tumour originated. For example, choriocarcinoma cells, which are derived from cancer of the placental trophoblast, can synthesise human chorionic gonadotrophin (hCG) (refs 1, 2), and cultured pituitary adenomas can produce growth hormone (GH) (ref. 3). On the other hand, it is well established that a variety of malignant human tumours can produce ‘ectopic’ peptide hormones and other proteins which are not normally associated with the tissue of origin4–8. Ectopic synthesis of placental proteins, including the placental isoenzyme of alkaline phosphatase as well as the hormones hCG and human placental lactogen, may provide specific markers for neoplasm, since these proteins are not normally found in measurable amounts in the serum of men or of non-pregnant women9. Several human glycoprotein trophic hormones, including hCG, thyroid-stimulating hormone (TSH), luteinising hormone (LH), and follicle-stimulating hormone (FSH), are composed of two non-identical subunits, α and β (refs 10–13). These four hormones have virtually identical α subunits; in contrast each has a unique β subunit, which is responsible for biological specificity12. Complete hCG and free subunits are secreted by normal and neoplastic placenta1,2,14 and by many non-trophoblastic tumours15,16. Since hCG is a eutopic hormone for trophoblastic tumours, but an ectopic hormone for non-trophoblastic tumours, it occured to us that its synthesis by the two types of tumours might be regulated differently. We therefore compared the synthesis of hCG and hCG-α by three choriocarcinoma cell lines—BeWo (ref. 1), JEG-3 (ref. 2) and Reid (P. O. Kohler, unpublished observations)—with the synthesis by two non-trophoblastic tumour-derived cell lines—ChaGo and HeLa. (ChaGo was derived from an hCG-producing pulmonary carcinoma16, and HeLa from a carcinoma of the cervix17.) We also tested the effects of sodium butyrate on the synthesis, since this compound had been shown to induce hCG-α and hCG synthesis in certain HeLa cells18. We found that in the absence of inducer, all of the cell lines can produce hCG-α—the trophoblastic tumour cells at roughly comparable rate, but the non-trophoblastic tumour cells at widely different rates (Fig. 1).

Effects of sodium butyrate on synthesis of human chorionic gonadotrophin in trophoblastic and non-trophoblastic tumours.

THE HeLa line, derived from a carcinoma of the cervix, was the first continuous human tissue culture line to be established in vitro1, and has been one of the primary sources for the study of human cell biology. Although such studies have documented the biosynthesis of certain intra-cellular and membrane proteins2–4, there has been little specific characterisation of proteins secreted by these lines. The human glycoprotein tropic hormones, thyroid-stimulating hormone (HTSH), follicle-stimulating hormone (HFSH), luteinising hormone (HLH), and chorionic gonadotropin (HCG), are each composed of two subunits—an immunologically indistinguishable and probably common α subunit (‘α’) and distinct β subunits which confer biological specificity on the complete molecule5–8. Complete hormones and free, isolated subunits are secreted by their normal cells of origin in pituitary or placenta under a variety of physiological and neoplastic circumstances9–11. Furthermore, complete hormones and isolated subunits can even be secreted ectopically—that is, by tissue which does not in normal conditions produce these proteins. Since ectopic a secretion has been documented for a variety of neoplasms, both in vivo12 and in vitro13, we examined the possibility that HeLa lines might also ectopically secrete the α subunit. We have found that three different HeLa strains secrete a substance immunologically indistinguishable from the α subunit, with secretion rates differing by as much as 50-fold.

HeLa cells secrete α subunit of glycoprotein tropic hormones

Growth of choriocarcinoma cells in the presence of 5-bromo-2′-deoxyuridine (BrdUrd) results in a 30- to 40-fold increase in alkaline phosphatase activity. The effect of BrdUrd is specific for phosphatase with an alkaline pH optimum. The induction by BrdUrd is probably not due to the production of an altered enzyme, since the induced enzyme resembles the basal enzyme in thermal denaturation and kinetic properties. Enzyme induction can be prevented by thymidine but not by deoxycytidine or deoxyuridine. The induction of alkaline phosphatase appears to require incorporation of the BrdUrd into cellular DNA. The presence of BrdUrd in the growth medium is not necessary for alkaline phosphatase induction in proliferating cells containing: BrdUrd-substituted genomes. However, enzyme induction and maintenance of the induced levels of alkaline phosphatase in nonproliferating cells containing BrdUrd-substituted DNA requires the presence of the analogues in the medium. The induction of alkaline phosphatase by BrdUrd in probably an indirect process.

https://www.jstor.org/stable/pdfplus/4291955.pdf

J. C. Robinson

Papers

Differential action of neuraminidase on human serum alkaline phosphatases.

Antigen polymorphism of a low-density beta-lipoprotein. Allotypy in human serum.

Effects of sodium butyrate on synthesis of human chorionic gonadotrophin in trophoblastic and non-trophoblastic tumours.

HeLa cells secrete α subunit of glycoprotein tropic hormones

Induction of placental alkaline phosphatase in choriocarcinoma cells by 5-bromo-2'-deoxyuridine.