Human breast carcinoma antigen is immunologically related to the polypeptide of the group-specific glycoprotein of mouse mammary tumor virus

We have shown [Mesa-Tejada, R., Keydar, I., Ramanarayanan, M., Ohno, T., Fenoglio, C. & Spiegelman, S. (1978) Proc. Natl. Acad. Sci. USA 75, 1529--1533] that an antigen immunologically related to gp52, a 52,000-dalton glycoprotein of the mouse mammary tumor virus, can be identified in sections of human breast cancer by means of an indirect immunoperoxidase technique. The specificity of the reaction was established by absorption experiments which revealed that only purified gp52, or material containing it, served to eliminate the IgG molecules responsible for the immunohistochemical reaction in the human breast tumors. We show here that the cross-reactivity between the human and murine tumor antigens is due to the polypeptide rather than the polysaccharide components of gp.52. Sugar-free gp52 prepared by deglycosylation with a mixture of glycosidases was as fully effective as the intact gp52 in removing from anti-MMTV the IgG responsible for the reaction with the human tumor antigen. In contrast, the isolated polysaccharide of gp52 was unable to exert blocking activity.

Thermoregulatory nonshivering thermogenesis in men, with special reference to lipid metabolism

The existence of thermoregulatory nonshivering thermogenesis, with special reference to lipid metabolism, was investigated in men. Acute cold exposure (10 degrees C, 60 min) produced a marked increase in heat production, with concomitant elevation of plasma free fatty acid (FFA) level, modest increase of ketone body concentration and lowered respiratory quotient (R.Q.). The correlation of heat production to plasma FFA levels was significantly positive; that is, subjects with higher heat production showed higher plasma FFA levels. Moreover, correlation of either heat production or plasma FFA levels to R.Q. was significantly negative, respectively. On the other hand, exposure to cold after an administration of nicotinic acid, which has a suppressive effect on FFA mobilization from adipose tissue, resulted in less cold-elevated heat production, a significant fall of plasma FFA and ketone body concentrations, and no change in R.Q. Although no visible or only slight shivering was observed in control cold exposure study, greater shivering occurred in the nicotinic acid cold exposure study. These results appear to indicate that nonshivering thermogenesis as a source of heat production achieved by enhanced utilization of lipids is also present in men.

Seasonal variation of plasma glucagon concentrations in men

In an attempt to understand a role of glucagon in seasonal acclimatization in men, measurements of plasma glucagon, blood free fatty acids (FFA), blood glucose, blood ketone body (beta-hydroxybutyrate) and hematocrit were made in 13 male and 8 female college staff members, aged 20 to 42, once a month for one year. Blood samples were obtained at 4:00 to 5:00 p.m, between meals. Average monthly temperatures during the study were as follows; Jan. -7.8, Feb. -5.6, March -3.7, Apr. 4.6, May 11.4, June 18.3, July 23.9, Aug. 22.0, Sept. 14.7, Oct. 7.5, Nov. 1.4, Dec. -4.2 (degrees C). Plasma glucagon, blood FFA and blood ketone body exhibited significant monthly variation in both sexes. Plasma glucagon as well as blood FFA level was significantly higher in winter (Dec., Jan., Feb.) than in summer (June, July, Aug), whereas blood ketone body level was lower in winter than in summer. Plasma glucagon level was significantly lower in female than in male subjects. A significant positive correlation was observed between plasma glucagon and blood FFA levels throughout the year. Seasonal variations of blood glucose and hematocrit were not observed. These results suggest that seasonal variation in glucagon secretion is associated with seasonal changes in ambient temperatures as one of the strategies for climatic acclimatization through regulation of lipid metabolism.

Gastric mucosal barrier in the rats fed with protein deficient diet or treated with carbon tetrachloride

The effects of protein deficient diet and liver damage on the gastric mucosal barrier were studied in 32 Sprague-Dawley rats. The animals were divided into 4 groups according to their dietary regimens, CCl4 induced liver damage and/or serotonin administration. Group 1 (control) was fed standard rat chow. Group II was fed a nonprotein diet for 2 weeks. Group III and IV were fed standard rat chow and given 1 ml of CCl4 per/Kg body weight intraperitoneally twice weekly for 12 weeks. Rats in Group IV were also injected with 20mg per/Kg of serotonin intraperitoneally 30 minutes prior to surgery. After pyloric ligation, an acid test solution composed of 100 mM HCl, 10mM NaCl, 5mM KCl and 5g per litre of PEG was instilled into the stomach and fluxes of Na +, K +, H + and Cl-ions across the gastric mucosa were measured. Compared to Group I, rats in Group II, III and IV demonstrated an increased net negative hydrogen flux (p less than 0.05). An increased net negative chloride flux (p less than 0.05) was also demonstrated in Group II and IV, but no increase was noted in Group III. There were no significant differences in fluxes of sodium and potassium ions. As mentioned above, a lack of protein in the diet, liver damage or both, renders the gastric mucosa of the rat more susceptible to injury. In the gastric mucosa of these rats, there have occurred more increase in the negative net fluxes of hydrogen and chloride ion, which may indicate the reduction of defence mechanism against a mucosal damage.

Identification of a large precursor of vitellogenin mRNA in the liver of estradiol-treated chicks

Studies were performed to determine whether vitellogenin mRNA from avian liver has a precursor molecule or not. Total cellular RNA was prepared from estradiol-treated chicken liver in the presence of 8 M guanidine HCl, 2-mercaptoethanol and aurintricarboxylic acid. After denaturation, RNA was fractionated on sodium dodecylsulfate-sucrose gradients and large size RNA was analyzed under stringent conditions on 85% formamide-sucrose gradients at 25 degrees C. RNA fractions collected from the gradients were hybridized with vitellogenin (3H)-cDNA. Besides mature vitellogenin mRNA (32S, 7,000 nucleotides) vitellogenin sequences were also found in RNA fractions ranging from 38-50S with a peak at 45-50S (12-15,000 nucleotides). Only 5-10% of the putative 38-50S pmRNA is polyadenylated. We calculated that the half-life of vitellogenin pmRNA is about 3-4 minutes. We conclude that vitellogenin mRNA has a precursor which is twice the size of the mature mRNA.

Immunohistochemical detection of a cross-reacting virus antigen in mouse mammary tumors and human breast carcinomas

An indirect immunoperoxidase method was first used to localize mouse mammary tumor virus (MMTV) antigens in paraffin sections of mammary tumors of Paris RIII and CD8F1 mice. By using the same method, an antigen with cross-reactivity to a group-specific antigen (gp52, a 52,000 dalton glycoprotein) of MMTV was detected in paraffin sections of human breast carcinomas. The specificity of this reaction with antibody against MMTV was examined by absorption of the IgG with: a) purified gp52; b) several relevant and irrelevant viral preparations; c) normal human plasma, leukocytes, breast tissue, milk, actin, collagen, and hyaluronic acid; d) sheep erythrocytes, bovine mucin and fetal calf serum. Only MMTV and prufied gp52 eliminated the immunohistochemical reaction in human breast tumors. Positive reactions were seen in 73 of 191 (38%) breast carcinomas of various histopathologic types, while negative reactions were obtained in all 137 normal and benign cases tested. A positive reaction of uncertain specificity was observed in foci of apocrine metaplasia. With one exception, 99 carcinomas from 13 organs other than breast and eight cystosarcomas were negative.

Colony-stimulating factors active on human bone marrow cells from a Yoshida sarcoma cell line

Colony-stimulating factors (CSF) active on both human and murine bone marrow colony-forming units in culture (CFU-C) were found in the conditioned medium of Yoshida sarcoma cells (line YSSF-212T), although the cells originated from rats. The CSF were inactivated by digestion with trypsin, alpha-chymotrypsin, and pronase. By chromatography on DEAE-cellulose, the CSF were separated into five subgroups with different capacities to stimulate mouse granulocyte and macrophage progenitors. CSF in these five peaks were eluted from an Ultrogel AcA 44 gel filtration column with apparent molecular weights of 22,000-25,000 daltons. CSF of nonhuman origin stimulating human CFU-C would be useful in hematologic studies of bone marrow cells.

Kinetics of biphasic reconstitution of tobacco mosaic virus in vitro

The kinetics of the in vitro reconstitution of tobacco mosaic virus from its RNA and protein were studied by measuring the increase in turbidity, the development of ribonuclease-resistant infectivity, the emcapsidation of the terminal ends of the RNA, and the growth of rod length. The results showed that the reconstitution reaction consists of two processes in which the direction, timing, and rate of assembly are different. Rapid elongation of particles toward the 5' end of the RNA proceeds in the first 5-7 min to give intermediate particles of 260 nm in length in which only the 5' terminus of the RNA is encapsidated. The subsequent process requires 30-50 min, is accompanied by a slow increase in turbidity, and gives rise to rods of the full length, 300 nm. The 3' terminus becomes RNase resistant by this process with concomitant development of ribonuclease-resistant infectivity, showing that the 3'-distal portion of the RNA is encapsidated in the direction of 5' to 3'. The rate of rod elongation by the second process is less than 1/10 of that by the first process.

In vitro RNA synthesis and expression of vitellogenin gene in isolated chicken liver nuclei

Optimal conditions for prolonged in vitro synthesis of RNA in isolated chicken liver nuclei have been described. It is shown by incorporation of gamma32P-GTP into RNA, analysis of the product on sucrose density gradient, and digestion with alkaline phosphatase and ribonuclease A that there is reinitiation of RNA synthesis. Polynucleotide kinase activity has been ruled out as explanation for the incorporation of gamma32P-GTP. alpha-Amanitin inhibits RNA synthesis by about 50%. Nuclei prepared from estradiol-treated chicks have twice the RNA synthesis activity as the controls. RNA is synthesized in the presence of Hg-UTP and the mercurated product separated by affinity chromatography on sulfhydryl-Sepharose column under stringent conditions. Vitellogenin mRNA sequences are measured by hybridization with DNA complementary to vitellogenin mRNA. Estradiol treatment leads to a 10-fold increase in vitellogenin mRNA sequences.

Detection of viral proteins in mouse mammary tumors by immunoperoxidase staining of paraffin sections

An indirect immunoperoxidase method is described, which can readily detect viral antigens in paraffin sections of primary, transplanted, and metastatic mammary tumors of mice. In addition to having the obvious advantage of not being limited to fresh specimens, immunoperoxidase staining of paraffin sections proved to be superior in many respects when compared with immunofluorescence and frozen sections. Immunoperoxidase staining of paraffin sections is permanent and provides the kind of histological detail required for precise cytological identification and localization with light microscopy. All of 25 tumors and 4 metastatic lesions showed evidence of glycoprotein gp52 as well as other mouse mammary tumor viral antigens. The pattern and intensity of the stain were related to the degree of histologic differentiation of the tumor. Wide variations in expression of viral antigens by individual malignant cells were observed within the same tumor.

Detection in human breast carcinomas of an antigen immunologically related to a group-specific antigen of mouse mammary tumor virus

An antigen immunologically related to a group-specific antigen (gp52, a 52,000-dalton glycoprotein) of the mouse mammary tumor virus has been identified in paraffin sections of human breast cancers by means of the indirect immunoperoxidase technique. The specificity of the reaction with antibody against mouse mammary tumor virus was examined by absorption of the IgG with the following: (a) purified gp52; (b) a number of virus preparations (mouse mammary tumor virus, Rauscher leukemia virus, simian sarcoma virus, baboon endogenous virus, and Mason-Pfizer monkey virus); (c) normal plasma, leukocytes, breast tissue, milk, actin, collagen, and hyaluronic acid, all of human origin; (d) sheep erythrocytes and mucin. Only mouse mammary tumor virus (from C(3)H or Paris RIII strains and grown in either murine or feline cells) and purified gp52 eliminated the immunohistochemical reaction in the human breast tumors. Positive reactions were seen in 51 of 131 (39%) breast carcinomas of various histologic types, a minimal estimate in view of the limited number of sections from each tumor that could be examined. Negative reactions were obtained in all 119 benign breast lesions (cystic disease, fibroadenoma, papilloma, gynecomastia) and in all 18 normal breast tissues. With one exception, 99 carcinomas from 13 organs other than breast and 8 cystosarcomas were all negative.