PubMed Health⌕ Search

Biomedical subjects

T J Linna

Publications and source records attributed to T J Linna.

At least 37 records · Page 2Linked to original sources
PubMed1982

Oxisuran: influence on allograft rejection and graft versus host reactivity in chickens and mice.

Oxisuran, a reported differential suppressant of cell-mediated immunity in several mammalian species, was evaluated for its capacity to prolong allograft survival and reduce graft versus host reactivity in chickens. In addition, the capacity of oxisuran to modulate cell-mediated immunity in mice was reappraised. In the chicken, the administration of 50, 100, or 1000 mg of oxisuran/kg body weight did not significantly prolong allograft survival. Furthermore, graft versus host (GVH) reactivity was not significantly diminished following treatment with 50 or 100 mg of oxisuran/kg body weight; however, GVH reactivity was significantly suppressed after administration of a high dose, 1000 mg of oxisuran/kg body weight. In mice, 100 mg of oxisuran/kg body weight slightly prolonged the survival of H-2a allografts on H-2d recipients, but it did not significantly alter GVH reactivity. Thus, the capacity of oxisuran to significantly suppress cell-mediated immune functions can be questioned at least in the species studied.

Animals↗
PubMed1982

Immune responses in nonhaired mice.

Ten stocks and strains of genetically nonhaired mice were evaluated for the ability to respond to two mitogens (concanavalin A and lipopolysaccharide) and to two antigens (sheep erythrocytes and pneumococcal polysaccharide, type III). The number of T and B lymphocytes in the thymus, spleen and pooled lymph nodes of individual animals were determined using immunofluorescent techniques; the values for each group of animals were found to be comparable. The antibody-forming ability was evaluated by determining the number of plaque-forming cells in the spleen after immunization with either antigen. All strains of mice responded to both antigens and the responses are discussed. All groups of mice responded to the mitogens tested.

Animals↗
PubMed1981

Staphylococcal protein-A agglutination assay for avian viruses.

Protein-A rich staphylococci were used to develop an agglutination assay for the detection and quantitation of avian reticuloendotheliosis virus (REV) and Herpes virus of turkeys (HVT). Rabbit anti-REV or anti-HVT were used to coat the staphylococci and these reagents were mixed with REV or various other viral antigen preparations. An agglutination titer was determined for antigen preparations of varying purity and the results indicated that in addition to being rapid, this assay allows the detection of as little as 0.3 to 0.5 microgram of partially purified viral antigens. No crossreactivity was observed with the two antisera and the various antigen preparations. This study also confirmed the reports in the literature that chicken immunoglobulins do not bind to protein-A of the Cowan I strain of Staph. aureus.

Agglutination Tests↗
PubMed1980

Transfer of natural resistance to Marek's disease (JMV) with nonimmune spleen cells. II. Further characterization of protecting cell population.

Spleen cells from 8-week-old, nonimmunized donor chickens can transfer resistance to a supralethal dose of the JMV leukemia line of Marek's disease (MD) to newly hatched, highly susceptible, histocompatible recipients. The population of cells transferring resistance has previously been shown to be non-T, non-B, and nonmacrophage in nature. We present data here showing that heavily x-irradiated spleen cells were unable to protect recipients from leukemia challenge. Both complement receptor-bearing and -lacking cells could confer resistance to newly hatched recipients. Fc receptor-bearing cells conferred significant protection to recipients, whereas spleen cells depleted of Fc receptor-bearing cells were unable to protect chickens from death after JMV challenge. This indicates that the population of spleen cells, which is moderately radiosensitive and which possesses Fc receptors, is responsible for the transfer of natural resistance to the malignancy in vivo.

Animals↗
PubMed1979

Transfer of natural resistance to Marek's disease (JMV) with non-immune spleen cells. I. Studies of cell population transferring resistance.

A "natural" resistance to Marek's disease, as well as to the malignancy caused by the laboratory JMV line of Marek's disease, develops with age. Resistance to this malignancy can be transferred from non-immunized, 8-week-old resistant chickens to newly hatched susceptible ones with spleen cells in a B-locus isogeneic combination. The cell transferring resistance does not seem to belong to the major T-cell, B-cell, or macrophage populations, and seems consequently to belong to the functionally heterogenous "third cell" population.

Age Factors↗
PubMed1976

Serotherapy of avian reticuloendotheliosis virus-induced tumors.

Immune serum, obtained from animals that had survived sublethal challenge with RE virus, was very effective in achieving tumor cures in chickens infected with this virus. The therapeutic effect could also be obtained by the immunoglobulin fraction of immune serum. The serum did not influence the development of an unrelated malignancy. Serotherapy studies in Bx and Tx recipients indicate that the B-cell or T-cell system of the host does not significantly contribute to the curative activity of immune serum. Absorption studies show that the curative effect is mediated by antibodies to tumor-associated transplantation antigens on tumor cells, not by antiviral antibodies.

Animals↗
PubMed1976

Increased growth rate of a benzo(a)pyrene-induced transplantable tumor in bursectomized chickens.

A benzo(a)pyrene-induced transplantable tumor was used to study the effects of bursectomy and thymectomy on tumor development in recipients that were isogenic with the donor for the major histocompatibility locus. Surgical bursectomies and thymectomies were done in different groups of chickens on the day of hatching, with no adjunct treatment. The following day, the experimental and control animals were given 10(3) live tumor cells s.c. Tumor frequency and size were followed weekly. With the experimental protocol used, thymectomy did not significantly affect tumor frequency or growth. Bursectomy did not affect tumor frequency, but the transplanted tumors grew significantly more rapidly in bursectomized than in control animals. Thus, bursectomy and, consequently, the antibody-forming system influence not only virus-induced tumors, but also the development of a chemical carcinogen-induced transplantable tumor line. The data underscore the host-protective role of the antibody-forming system in oncogenesis.

Animals↗
PubMed1976

Impaired host defense against XC cell-induced tumors in thymectomized and in bursectomized chickens.

XC cells originally derived from the tumor of a rat previously inoculated with the Prague strain of Rous sarcoma virus were used to induce tumors in chickens surgically thymectomized or bursectomized in the newly hatched period. Thymectomized chickens had a significantly higher incidence of tumors, larger tumors, and a higher tumor mortality, compared with control chickens, when both groups were given 5 X 10(6) XC cells into the wing webs. Bursectomy could significantly influence the tumor size only. It appeared that the capacity of XC cells to induce tumors and the growth of such tumors were subject to immunological influence, with the thymus playing a major and the bursa of Fabricus a minor role under the conditions used.

Animals↗
PubMed1975

The inability of surgical bursectomy in the newly hatched period to affect antibody formation in the pigeon (Columba livia).

Surgical bursectomy was performed in newly hatched pigeons within 24 hours of hatching. The effect of bursectomy on the immune responsiveness was evaluated by studying antibody formation to sheep red blood cells (SRBC) and Brucella abortus organisms and by the presence of serum immunoglobulins after immunoelectrophoresis. Surgically bursectomized pigeons responded as well to SRBC and Brucella as did the non-bursectomized controls. There was no statistically significant difference in the geometric mean antibody titers between the bursectomized and non-bursectomized groups of pigeons. Treatment of the serum with 2-mercaptoethanol (2-ME) indicated that the major amount of antibody produced was resistant to 2-ME and there was no significant difference in the amount of 2-ME-resistant antibody produced in the bursectomized and the control pigeons. Immunoelectrophoretic analysis of the sera from the bursectomized pigeons showed both IgG and IgM present in similar quantities to that of the non-bursectomized controls. Histological sections of the spleens showed germinal centers in both groups of pigeons. Sections of the bursal area from the bursectomized birds indicated that none of the pigeons in the bursectomized group had any remaining identifiable bursal tissue, follicular structures or other organized lymphoid tissue.

Animals↗
PubMed1975

Preferential incorporation of 3H-deoxycytidine into chicken bursal cells. Comparison of radiolabelled nucleosides as lymphoid cell markers in chickens and mice.

3H-deoxycytidine, 3H-thymidine and 125I-deoxyuridine were injected intravenously into different groups of chickens and mice, and lymphoid organs and intestine of the animals sampled one hour later. Incorporation of the isotopes into proliferating cells was evaluated after nucleic acid extraction and determination of specific activity of the isotopes in counts per minute per microgram of DNA (cpm/mug DNA). Labelled deoxycytidine was incorporated much better into bursal cells than the other isotopes, indicating that this isotope may preferentially label bursal lymphocytes, or a subpopulation of them.

Animals↗