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Biomedical subjects

R Mattsson

Publications and source records attributed to R Mattsson.

52 records · Page 3Linked to original sources
PubMed1988

Effects of pseudopregnancy on immunoglobulin-secreting cells in mice.

Pregnant mice characteristically show elevated numbers of immunoglobulin-secreting cells in their enlarged spleen and para-aortic lymph nodes. A comparative study of pseudopregnancy and syngeneic pregnancy in CBA/Ca mice was made to evaluate the role of maternal hormones in the induction of these changes. To induce pseudopregnancy, CBA/Ca female mice were mated with vasectomized males, the duration of pseudopregnancy induced in this way is 8-10 days. Serum progesterone levels were monitored periodically throughout pseudopregnancy using RIA technique. Changes were recorded in weight of the thymus, spleen and para-aortic lymph nodes, levels of serum IgG and IgM (ELISA-technique), and content of splenic IgG- and IgM-secreting cells (protein A plaque assay). Thymus involution was observed in pregnant and pseudopregnant mice. Patterns of change in the weight of the spleen and the para-aortic lymph nodes (PALN) were similar in pregnant and pseudopregnant mice until day 8. Ig-secretion in the spleen increased slightly day 5-8 in both pregnant and pseudopregnant mice, but to a lesser extent in the latter. No differences were observed in serum Ig levels between the two groups until day 8. A marked decrease in serum IgG levels and, to some extent, IgM levels between days 8 and 12 was observed in pregnant animals.

Animals↗
PubMed1988

Comparison of serum and lung extracts for surveys of wild animals for antibodies to Francisella tularensis biovar palaearctica.

A comparative study of the antibody titer against Francisella tularensis biovar palaearctica in serum and lung extract was made using different immunoassays. Samples were taken from experimentally-infected goshawks (Accipiter gentilis) and European beavers (Castor fiber), and in a field survey of wild beavers. Good accordance between the antibody titer in serum and in lung extract was found in the experimental studies. However, the antibody titer was generally one- to three-fold lower in lung extract than was the titer of serum. Results in the field survey were less reliable. Estimating antibody titer in lung extract is a practical method for surveys for antibody levels, and an alternative to serological surveys, despite lower sensitivity as compared to serum.

Agglutination Tests↗
PubMed1988

Experimental infection of five species of raptors and of hooded crows with Francisella tularensis biovar palaearctica.

Sixteen raptors and three hooded crows were infected experimentally with Francisella tularensis biovar palaearctica. The birds were infected parenterally or per os. One goshawk, one sparrow hawk and one hooded crow died during the experimental period, and the remaining 16 birds were killed 14-77 days after the first infection. Francisella tularensis was not isolated from any bird. Antibody levels against F. tularensis measured in nine birds varied from 0 to 1:1,280. In one goshawk with a titer of 1:1,280, positive fluorescent antibody reactions against F. tularensis were seen in the liver and spleen. These results are similar to those found by other authors indicating that raptors and corvids are normally resistant to infections with F. tularensis.

Agglutination Tests↗
PubMed1988

Infections with Francisella tularensis biovar palaearctica in hares (Lepus timidus, Lepus europaeus) from Sweden.

The occurrence of tularemia was studied in 1,500 hares submitted to the National Veterinary Institute, Uppsala, Sweden for postmortem examination during 1973 through 1985. A total of 109 tularemia cases was recorded based on the fluorescent antibody (FA) test for Francisella tularensis and on the gross and microscopic pathology. Tularemia was diagnosed only in the varying hare (Lepus timidus) and not in the European brown hare (Lepus europaeus). The geographical distribution of the 109 cases indicates that tularemia has not spread in Sweden during the last 45 yr, with the exception of an endemic occurrence of the disease on the island of Stora Karlsö in the Baltic sea. The disease was most frequent in the autumn and only a few cases were recorded during winter. Cases were not seen in the spring. The annual prevalence varied, with several cases in 1974 and 1981, but there were no cases in 1976 and 1980. The postmortem findings in hares dying of tularemia in the autumn were characterized by focal coagulative necrosis in liver, spleen and bone marrow, with high numbers of bacteria FA-positive for F. tularensis. In hares dying during winter months, the most characteristic findings were hemorrhagic enteritis and typhlitis, although necrotic lesions could occur in liver, spleen and bone marrow. Diseased hares on the island of Stora Karlsö were demonstrated to be infected with ticks, while hares on the mainland of Sweden generally were fed upon by mosquitoes. Twenty-six of the 109 hares with tularemia were examined bacteriologically and F. tularensis biovar palaearctica was isolated from eight. The lung extract antibody test for F. tularensis was performed in 18 of the 109 hares. All were negative. In addition to the field study, an experimental study with F. tularensis biovar palaearctica was performed. Four varying hares and three European brown hares were inoculated. None of the hares died from tularemia, and generalized infection was not demonstrated.

Animals↗
PubMed1987

Maintained allogeneic pregnancy in rats depleted of T cytotoxic/suppressor cells by OX8 monoclonal antibody treatment.

It has been suggested that CD8 positive suppressor T-cells might be of importance in the non-rejection of the fetus. In the present investigation allogeneically pregnant (Lewix x DA) rats were subjected to in vivo treatment with monoclonal OX8 antibodies, reactive with the rat equivalent of CD8 receptor. This treatment protocol drastically reduced the numbers of OX8 positive cells in spleens and para-aortic lymph nodes. On the day of delivery these rats, together with normal IgG treated controls, were dissected and analysed for effects on: (1) fetal survival; (2) weight and immunohistology of spleens and para-aortic lymph nodes; (3) total numbers of IgM- and IgG-secreting cells within these organs. The OX8 treated rats passed through pregnancy as successfully as did the controls. Both groups showed the same type of pregnancy-induced changes in their lymphoid organs, including dramatic growth of the para-aortic lymph nodes and increase in Ig-secretors within both spleen and para-aortic lymph nodes. This pattern was the same in all pregnant rats investigated, including untreated syngeneically mated Lewis rats. It is concluded that OX8 positive T "suppressor" cells do not play an important role in the maintenance of the fetal-placental unit.

Animals↗
PubMed1985

Allogeneic pregnancy in B-lymphocyte deprived CBA/Ca mice--effects on maternal lymphoid organs and fetal survival.

A number of female CBA/Ca (H2-k) mice were injected with rabbit-anti mouse IgM every 2 days throughout their life cycle in order to prevent their development of immunocompetent B-lymphocytes. The efficiency of the anti IgM-treatment was good in the group of mice used, and all experimental mice almost completely lacked 1) surface Ig-staining cells (immunoperoxidase ABC method), 2) serum IgG (ELISA technique), and 3) Ig-secreting cells (protein A plaque assay). All experimental mice contained a functioning T-cell pool, as recorded in vitro by conA-stimulation and one-way MLC. At an age of 40-60 days these mice were allowed to mate allogeneically with C57/Bl (H-2b) males. No harmful effects of the anti-IgM treatment on the first pregnancy cycle were found, and B-cell deprived mice delivered as many healthy litters as did the controls. It was also observed that the enlargement of the spleen and uterus-draining nodes was of the same magnitude in both experimental and control mice at the end of the first pregnancy.

Animals↗
PubMed1984

Anemia causes erythropoiesis and increased antibody synthesis in the spleen of the pregnant mouse.

The role of anemia in the induction of splenic alterations during pregnancy has been studied in mice and rats. The enlarged spleens of 12 day pregnant CBA mice typically showed dramatic increase in numbers of esterase-positive cells (mainly erythroblasts) and increase in numbers of immunoglobulin-secreting cells. Pregnant Sprague-Dawley rats showed slight enlargement of the spleen, no change in the content of esterase-positive cells, but a clear-cut increase in numbers of Lepehne -stained erythroblasts and immunoglobulin-secreting spleen cells. Virgin mice and rats were made anemic by bleeding or phenylhydrazine-treatment. These animals showed very much the same splenic alterations as those of pregnant mice and rats. In a final experiment pregnant CBA mice were subjected to transfusion of washed syngeneic red blood cells in order to normalize their erythrocyte counts. These mice showed reduced splenomegaly, reduced increase in numbers of esterase-positive cells and reduced numbers of immunoglobulin-secreting cells. It was concluded that pregnancy-associated anemia ( erythropenia ) is a major reason to the gross change in size and cell content of the maternal spleen.

Anemia↗
PubMed1984

Splenic macrophages during pregnancy in the mouse.

Pregnant CBA/Ca mice at mid-gestation showed a two-fold increase in the relative content of splenic macrophages, a change which was suggested to be due to enhanced migration. The proportion of spleen cells carrying a high density of Fc-receptors (assayed by EA-rosetting) was similarly increased in pregnant mice. The splenic content of non-lymphoid strongly esterase-positive cells was dramatically elevated at mid-gestation, but this increase was shown basically to be due to elevated numbers of esterase-staining erythroid blast cells. The pattern of the increase of Ig-secreting spleen cells was compared with that of macrophages and erythroid blast cells, and possible unspecific interaction at tissue-level is discussed.

Animals↗
PubMed1984

Immunoglobulin-secreting cells in various maternal lymphoid tissues during syngeneic and allogeneic murine pregnancy.

The effects of syngeneic (CBAxCBA) and allogeneic (CBAxC57/B1) pregnancy on immunoglobulin (Ig)-secreting cells in various maternal organs/tissues have been investigated by using the protein A plaque assay. The following organs/tissues were examined: a) spleen, b) cervical nodes, c) inguinal nodes, d) mesenteric nodes, e) para-aortic (uterus-draining) nodes, f) Peyer's patches, and g) bone marrow (femur). The changes observed were similar and of the same magnitude in all pregnant animals, irrespective of the type of mating. At mid-gestation (day 14) a distinct increase in Ig secretors was observed, predominantly in the spleen. At the end of pregnancy (day 20) the para-aortic nodes contained dramatically increased numbers of plaque forming cells. A slight increase in both IgM and IgG-secreting cells was also seen in bone marrow at the very end of pregnancy, while Peyer's patches and the nodes of neck and legs appeared to be unaffected throughout the period of gestation.

Animals↗
PubMed1983

Changes in the spleen cell populations of the mouse during pregnancy--the influence of the thymus.

The spleens of "unimmunized" 14 day pregnant and virgin adult thymectomized and sham operated CBA mice were compared with respect to the content of cytotoxic T-cells immunoglobulin-secreting B-cells and strongly esterase positive cells. In addition, 14 day pregnant NMRI/nu nu (athymic) and NMRI/nu ++ (immunocompetent control) mice were investigated. Pregnant thymectomized and pregnant sham operated mice showed almost identical changes: a) enlargement of the spleen, b) slightly reduced T-cell cytotoxicity, c) a 3-fold increase in the spleen content of immunoglobulin-secreting B-cells, and d) a 4-fold increase in the proportion of esterase-positive cells. The nude mice showed the same degree of spleen enlargement and increase in the number of immunoglobulin-secreting cells during pregnancy as the immunocompetent controls.

Animals↗
PubMed1982

Increase in the number of splenic plaque forming cells with length of gestation in untreated pregnant mice.

The number of plaque forming cells (PFC) in spleens from untreated virgin and syngeneically pregnant CBA mice has been evaluated by use of two different hemolytic plaque assays. The total number of splenic IgM- and IgG-PFC in virgin and 16 day pregnant mice was determined by protein A- sheep red blood cell (SRBC) plaque assay. The number of both IgM- and IgG-PFC was significantly increased in spleens from pregnant mice, but the total number of IgM-PFC was several times higher than that of the IgG-PFC. In the same experiment the number of splenic anti-trinitrophenyl (TNP) PFC was determined simultaneously. The values obtained for anti-TNP PFC in the different animals were found to correlate with the values for IgM-PFC in the protein A-SRBC plaque assay. Finally, the number of splenic anti-TNP PFC was determined at different occasions during pregnancy (day 4, 8, 12, and 16). It was found that the number of anti-TNP PFC was elevated as early as the 4th day of pregnancy, and that the number of PFC per spleen increased with the length of gestation.

Animals↗
PubMed1981

Effects of a hexachlorinated biphenyl on lymphoid organs and resorption of foetuses in pregnant mice.

Syngeneically and allogeneically mated CBA mice were daily given orally either pure peanut oil or peanut oil containing 0.5 mg 2,2', 4,4', 5,5'-hexachlorobiphenyl (HCB) beginning at the day of implantation. The mice were dissected on day 12 and 18 of gestation when the weight of thymus, spleen, and liver were recorded. The spontaneous mitotic activity of spleen cells was evaluated in vitro, and the number of resorbed foetuses was recorded. Neither spleen weight nor thymus weight was altered, but the liver weight was significantly increased by HCB treatment. The spontaneous mitotic activity of spleen cells did not differ significantly between HCB-treated and control mice. The frequency of resorbed foetuses was not increased by HCB treatment either in syngeneically or allogeneically mated mice, but it was observed that mice fed HCB were less sensitive to environmental disturbance than control mice.

Animals↗
PubMed1972

[Aerodontalgia].

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Aerospace Medicine↗