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Biomedical subjects

E F Hays

Publications and source records attributed to E F Hays.

At least 73 records · Page 4Linked to original sources
PubMed1976

Virion interaction in mouse lymphomas.

Virion expression in filtrates of lymphomas in AKR/J or C3H/HeJ mice was assayed by two techniques: (a) in vitro infectivity (XC assay), or (b) acceleration of oncogenicity in vivo (O assay). The two assays appeared to detect different virus populations or activities. This was shown when the same filtrates were tested in parallel by the XC and O tests and opposite results were obtained on the two assays, e.g., XC+ 0- or XC- O+. It was postulated that two viruses, termed "XC+" and "O" to correspond to the assays used to detect them, were involved in oncogenesis. When lymphomas originally virus induced were passaged by cells in 2- to 3-month-old syngeneic AKR or C3H mice, oncogenic activity of filtrates of these transplanted lymphomas decreased as cell passages increased. These filtrates from C3H lymphomas also had decreased XC activity as cell passages increased. Normal lymphoid tissue from 1- to 5-month-old AKR mice was XC+ O-, while from C3H mice it was XC- O-. Thus, the two strains modified activities lacking in their normal tissues. Filtrates highly oncogenic in XC+ newborn AKR mice were oncogenic in C3H newborn mice only when sufficient XC+ virus was in the inoculum received by the XC- C3H mice. Thus the XC+ virus appeared to play a synergistic role with a postulated O virus in oncogenesis.

AKR murine leukemia virus↗
PubMed1975

Hemopoietic colony forming cells in regenerating mouse liver.

Cells from regenerating mouse liver removed 2-25 days post 68% hepatic resection have been assayed for in vivo colony forming capacity in soft agar (CFU-C), proliferative capacity in liquid culture, and in vivo spleen colony forming capacity (CFU-S). These studies demonstrated low concentrations of CFU-C and CFU-S in normal and sham operated liver, with an appreciable increase of both in regenerating liver, reaching maximum values in tissue removed 5--7 days post hepatic resection. Colony formation in agar by regenerating liver cells occurred in the absence of exogenous colony stimulating factor. Separation of liver cells on the basis of adherent properties prior to culture indicated concentration of CFU-C in the non-adherent fraction, while cells producing colony stimulating factor were concentrated in the adherent fraction. Foci of actively dividing cells of themacrophage and granulocyte series arose in liquid culture from preparations of sham operated and regenerating liver, although total cell formation was greater with regenerating liver. A small proportion of the colonies formed in agar from regenerating liver consisted of cords of epithelioid cells, which resembled hepatocytes and differed from the macrophages or granulocytes found in the majority of colonies, raising the possibility that regenerating hepatocytes form colonies in agar culture.

Animals↗
PubMed1975

Virus expression and immunoprophylaxis of a murine lymphoma.

CBA mice tested with a rapidly lethal transplanted lymphoma could survive challenge when pretreated with allogeneic lymphoma cells or other material expressing murine leukemia virus (MuLV). Protection resulted when recipients were given injections of AKR and C3H transplanted lymphomas or selected normal AKR and SJL tissues, filtrates of which give positive assays for MuLV by in vitro and/or in vivo tests. There was no protection when recipients were given injections of C3H lymphomas or C3H normal tissues that failed to have positive assays for virus.

Animals↗
PubMed1970

Decreased growth capacity of passaged gross virus-induced mouse lymphomas after incubation with antithymocytic sera.

AKR or C3H/HeJ transplanted mouse lymphomas, originally induced by Gross virus, could be neutralized by in vitro incubation with an immunosuppressive rabbit anti-mouse thymus cell serum. Neutralization was measured by significantly increased latent periods or decreased incidence (at a minimum of 90 days post-transfer) of lymphoma in syngeneic recipients of lymphoma cells incubated with antithymocytic serum when compared with syngeneic recipients of lymphoma cells incubated with normal rabbit serum.

Journal Article↗
PubMed1970

Immune response in preleukemic mice.

Humoral and cellular immunity was assessed serially in preleukemic AKR mice and Gross virus-injected C3H/HeJ mice over a period of 10 to 12 months. Quantitative gamma globulin, hemagglutinin and hemolysin titers after immunization with sheep red blood cells, and macrophage-migration inhibition were determined. Normal production of gamma globulins as well as humoral antibodies was found in both of these experimental groups of mice, whereas macrophage-migration inhibition, which is believed to be a correlate of cellular immunity, appeared to be abnormal throughout the life of these animals, which were destined to develop a high incidence of lymphoma. Some aspects of this apparent dissociation between humoral and cellular immune response are discussed with regard to the mouse virus lymphoma system, primarily involving the thymus, which was used in these studies.

Journal Article↗
PubMed1970

Increased Incidence of Lymphoma in C3H/HeJ Adult Mice Injected with Gross Virus and Antithymocytic Serum.

An increased incidence of lymphoma in adult C3H/HeJ mice injected with antithymocytic serum as compared with normal rabbit serum during a course of one to four weekly intraperitoneal injections of cell-free filtrates of Gross virus-induced lymphomas was noted. The latent period of lymphoma ranged from 119 to 298 days after initiation of treatment. The incidence tended to increase as the number of injections of cell-free filtrate was increased, with a maximum incidence reached at three injections.

Journal Article↗
PubMed1969

Effects of short-term epithelial reticular cell and whole organ thymus grafts in neonatally thymectomized mice.

Neonatally thymectomized mice were implanted with thymus grafts composed of epithelial reticular cells for periods of 7 and 14 days. Regardless of whether the grafts were placed immediately after thymectomy, or at 3 wk of age, there was little recovery of the lymphocyte depletion and impaired immunologic responsiveness, characteristically found in a neonatally thymectomized host. The findings were similar in animals studied at 2 months or 2 wk after graft removal. Many of the short-term remnant grafts were populated with lymphocytes and had attained the morphologic appearance of thymus by 14 days. A lesser degree of lymphocyte depletion and impaired responsiveness to SRBC occurred if thymectomy was delayed until 7 days of age, if remnant grafts were removed after 2 months, and if intact neonatal thymus was used for the short-term grafts. Complete normality was found in some of the animals in all of these groups. These observations suggest a direct role for mature thymus lymphocytes in reconstituting the neonatally thymectomized host and indicate that epithelial cell function is to direct the maturation of cells that ultimately behave as thymus lymphocytes.

Age Factors↗