Immunologic characterization and molecular profile of carcinoembryonic antigen detected by monoclonal antibodies

Four distinct monoclonal antibodies, which reacted with CEA preparations but not with nonspecific cross-reacting antigen or with nonspecific cross-reacting antigen 2, were established. Except for monoclonal antibody AS001 , all of these monoclonal antibodies immunoprecipitated molecular forms of 200K and 180K daltons that are not bridged by disulfide bonds. Immunodepletion experiments and sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis revealed that these monoclonal antibodies recognized the same antigenic structure when 125I-CEA preparation was used. Monoclonal antibody AS001 is of particular interest, because this antibody reacted only with a 200K dalton molecule which is a part of the molecules recognized by the other three monoclonal antibodies. The rosette inhibition assay and the immunoprecipitation experiments suggest that each monoclonal antibody recognizes a different antigenic determinant. The antigenic determinants recognized by monoclonal antibodies YK013 and AS001 may be peptides in nature, whereas the determinants recognized by antibodies YK024 or AS005 might be carbohydrate. The radioimmunoassay with monoclonal antibody AS001 was established, and the results clearly indicate that the incidence of positivity for the sera from digestive tract cancer patients and from lung cancer patients obtained by monoclonal antibody AS001 was higher than that obtained by the polyclonal antibody. Monoclonal antibody AS001 was able to detect the corresponding antigen in the sera, which the polyclonal antibody failed to detect. This study therefore suggests that monoclonal antibodies may enhance and improve the diagnostic value in cancer patients with undetectable or lower CEA levels detected by conventional anti-CEA antibodies.     

Fetal hemoglobin variants in 80,000 Japanese neonates: high prevalence of Hb F Yamaguchi (AγT 80 Asp→Asn)

Summary A population-based screening of newborns for the structural variants of fetal hemoglobin was carried out in Osaka Prefecture, Japan, by isoelectric focusing of globin chains using dried blood on filter paper. Of 80,000 newborns, 18 had globin variants and 55 had globin variants. The incidence of globin variants (1/1,455) was much higher than that of globin variants (1/4,444). Structural studies were then carried out on the abnormal globins in 36 samples, and revealed that 25 of them were Hb F Yamaguchi (^AT 80 AspAsn). The prevalence of this variant in Japanese was estimated to be as high as one per 2,100.     

Genetic analysis of a pleiotropic deletion mutation (delta igf) in Bacillus subtilis.

A delta igf mutation of Bacillus subtilis (formerly called fdpAl) is a large deletion causing pleiotropic defects. The mapping of the delta igf deletion by phage PBS1 transduction revealed the following map order: sacA, thiC, hsrE, delta igf, ts199, purA. To analyze the pleiotropic nature of the delta igf mutation, mutants affected in each property of the pleiotropic mutation were isolated, and the mutations were mapped. iol and gnt mutants could not grow on inositol and gluconate, respectively, and fdp mutants were affected only in fructose-bisphosphatase. The map order from sacA to purA was as follows: sacA, thiC, hsrE, iol-6, gnt-4, fdp-74, hsrB, ts199, purA. The delta igf deletion covered loci from iol-6 to hsrB.     

Characteristics of specific binding of epidermal growth factor (EGF) on human tumor cell lines

Using seventeen human tumor cell lines derived from a variety of tissues, specific binding sites for epidermal growth factor (EGF), a mouse submandibular gland-derived growth factor, has been characterized. A significant amount of membrane-bound EGF receptors, although considerably varied, was demonstrated in all the tumor cell lines studied. Epidermoid carcinoma appeared to have more EGF receptors than adenocarcinoma. One small cell carcinoma of the lung, one choriocarcinoma of the stomach and three bone tumors also possessed EGF receptors comparable to those of epidermoid carcinoma, while one adenoacanthoma of the stomach had less EGF receptors comparable to adenocarcinoma. Among a variety of phorbol esters tested, tetradecanoyl phorbol acetate, a potent tumor promotor, was shown to be the most effective compound in inhibiting 125I-labeled EGF binding to its receptors. Our results indicate that human tumor cells contain varying amounts of membrane-bound receptors for EGF and that phorbol esters interact with these EGF receptor sites. However, the relationship between EGF receptor sites on tumor cells and cellular proliferation and/or differentiation awaits further study.     

Peripheral resistance and red cell LiNa countertransport in borderline hypertensives

We have studied ouabain-resistant, external sodium-stimulated, lithium efflux (LiNa countertransport) in red blood cells from 21 borderline hypertensives with at least one hypertensive first degree relative (BH-F), 19 borderline hypertensives without family history of essential hypertension (BH-NF), and 35 age-matched normotensive subjects. The data indicate the finding of an increased LiNa countertransport in all BH (F+NF), but with a significant overlap between BH values and control ones: LiNa countertransport is significantly higher only in BH-F but it is normal in BH-NF. Moreover, there is a significant correlation of LiNa countertransport to total peripheral resistance but not to mean blood pressure in all hypertensive patients. It is suggested that in BH the increase of erythrocyte Na flux is mediated by the NaNa exchange diffusion, and its abnormality may be associated to the hereditary trait of essential hypertension rather than the high blood pressure per se, probably resulting in the development of hypertension, through the increased vascular smooth muscle tone.     

The frequency among Japanese of heterozygotes for deficiency variants of 11 enzymes

Eleven human enzymes, chosen for this study because of relatively small coefficients of variation for mean activity, have been surveyed for the frequency with which activities less than or equal to 66% of the mean value occur. This criterion should detect almost all heterozygotes for variants lacking any activity plus a fraction of the persons with variants characterized by markedly depressed activity and/or instability. The enzymes surveyed are TPI, PGK, AK1, LDH, GAPD, GPI, PK, 6PGD, G6PD, GOT1, and HK. The number of determinations per enzyme ranged from 310 to 3,173, for a total of 26,634 determinations. Family studies have thus far been possible in 52 instances in which the initial observation of activity less than or equal to 66% of normal was confirmed. In every instance, a parent exhibited a similar finding, giving confidence that a true genetic entity was being detected. With this approach, the frequency of heterozygotes per 1,000 determinations varied from 0.0 (AK1, 6PGD) to 13.8 (PK), with an average of 2.4. For these same systems, in this laboratory the frequency of "rare" electrophoretic variants is 2.3/1,000, the ratio of the latter to the former thus being 1.0 in Japanese. Our experience with these deficiency phenotypes to date suggests that for selected enzymes such phenotypes can be incorporated into a program designed to detect mutational events.     

The interaction between lipid peroxidation and prostaglandin synthesis in rabbit kidney-medulla slices.

Lipid peroxidation induced by ascorbic acid and Fe2+ was inhibited by mepacrine (phospholipase A2 inhibitor) and aspirin (prostaglandin cyclo-oxygenase inhibitor) in rabbit kidney-medulla slices. Moreover, ascorbic acid and Fe2+ potentiated the inhibitory effect on prostaglandin E2 formation by mepacrine, but they had no influence on prostaglandin E2 production decreased by aspirin. Lipid peroxidation induced by ascorbic acid and Fe2+ appears to be affecting the activity of prostaglandin endoperoxide synthase. These results suggest that lipid peroxidation is connected closely with the prostaglandin-generating system, and it has the potential to modulate the turnover of arachidonic acid and prostaglandin synthesis.     

Mutants of Group D1Salmonella Carrying the Somatic Antigen of Group A Organisms: Isolation and Serological Characterization

O antigen mutants were obtained from Salmonella durban, a group D(1) organism, by treatment with N-methyl-N'-nitro-N-nitrosoguanidine. Serological studies demonstrated that the mutants lost the O-9 antigen factor of the parent organism but acquired the O-2 factor specific to group A Salmonella. Lipopolysaccharides of the mutant strains contained paratose which determines the specificity of O-2 factor. Tyvelose, present in the wild-type lipopolysaccharide, was not found in the mutants. H antigens and other biological characteristics of the mutant strains were the same as those of the wild-type organism. The present finding implies that group A Salmonella species might be derived from group D(1) organisms.     

Mutants of Group D1Salmonella Carrying the Somatic Antigen of Group A Organisms: Evidence for the Lack of Cytidine Diphosphate Paratose-2-Epimerase Activity

The mutant strains of Salmonella durban that possessed O antigen 2, 12 of group A Salmonella were defective in the cytidine diphosphate paratose-2-epimerase activity. The enzyme preparation of the mutant strains catalyzed the conversion of cytidine diphosphate glucose into cytidine diphosphate paratose but not into cytidine diphosphate tyvelose. The defect in the epimerase activity was also confirmed by the use of purified cytidine diphosphate paratose as a substrate. The specificity of dideoxyhexosyl transferase catalyzing the formation of the group-specific determinant is discussed.     

Analysis of cytokinetics by means of Feulgen cytofluorometry combine with 3H-thymidine autoradiography

DNA cytofluorometry combined with autoradiography after pulse-labelling with ³H-TdR visualizes movement of the labelled cells along the cell cycle. If the specimen is fixed after an adequate waiting time, this method enables us to measure the absolute length of the S phase in a cell population with a single sampling. The method was applied for Yoshida sarcoma cells proliferating in the rat ascites. Using a single specimen fixed after 4 h waiting time, the shortest, the average, and the longest durations of S phase in the population were estimated at 5.8, 7.5 and 13 h, respectively. Measurement on a flash-labelled specimen gives the relative durations of G 1, S, G 2 and M. It is shown that, using these 2 samples, a complete cell cycle time analysis can be performed.