G. E. Cosgrove

Relationship of pathology to scolex morphology among Caryophyllid cestodes

SummaryThe comparative pathology as related to modes of attachment and scolex morphology of the following 15 species of caryophyllid cestodes was studied: Caryophyllaeus laticeps, Monobothrium ingens, M. hunteri, M. ulmeri, Glaridacris catostomi, G. confusus, Biacetabulum infrequens, B. biloculoides, B. carpiodi, Hunterella nodulosa, Isoglaridacris folius, Khawia iowensis, Atractolytocestus huronensis, Capingens singularis and Spartoides wardi. Species with specialized holdfasts having loculi, bothria, or acetabula elicit little or no pathology; on the other hand, those with a terminal introvert, weakly developed loculi, or lacking specialized structures elicit pronounced host reactions in the form of nodules or shallow ulcers. Species with similar types of scolexes appear to attach in similar ways. An interface layer, apparently mucoid in nature as shown by histochemical tests, is often present between host and parasite of some species. Distribution in the intestine, multiple infections, and niche width as related to scolex morphology are discussed. Photomicrographs of species in situ, of pathology, and drawings of scolex types supplement the observations.

EFFECT OF AGE OF RECIPIENT MICE ON GROWTH AND DIFFERENTIATION OF TRANSPLANTED BONE MARROW CELLS.

Summary Female RFM/Un mice exposed at various ages to whole-body X-radiation of 750 R followed by injection of syngeneic bone marrow cells showed a marked increase in megakaryocyte colonies in the spleen as the age of the mice at irradiation was increased from 30 to 72 weeks. A postirradiation splenic megakaryocytosis was also noted in a minority of similarly irradiated old mice which received no exogenous marrow cells. Hence, the megakaryocytes in the marrow-injected animals may be presumed to have been partially of host, as well as donor, origin. Variation in the age of the bone marrow donor over the same age range was without effect. The mechanism of the age-dependent megakaryocytosis in recipients remains to be determined.

SOLUBILITY OF HEMOGLOBIN AS RED CELL MARKER IN IRRADIATED MOUSE CHIMERAS

Summary Genetically different mouse hemoglobins differ in solubility and crystal formation. Differences in hemoglobin solubility and crystal formation can therefore be used to identify homologous erythrocytes in irradiated mouse chimeras if the hemoglobin types of donor and recipient mice are distinguishable by these properties to begin with.

Preliminary Observations on Spontaneous and Radiation-Induced Leukemia in Germfree Mice.

Summary Germfree ICR and RF mice X-irradiated in a single exposure to 300-900 R have been observed for leukemia for periods up to 10 months after irradiation, along with nonirradiated controls. Preliminary data indicate that the cumulative incidence of leukemia in the irradiated germfree mice is as high as, or higher than, in the irradiated conventional mice. The incidence is higher in both irradiated groups than in the unirradi-ated germfree and conventional controls, which do not differ in spontaneous leukemia incidence. All leukemias examined thus far histopathologically have been lymphosarco-mas. Tissues of a germfree RF mouse with X-ray-induced leukemia contained tailed “virus-like” particles similar to those noted in conventional mice and associated with transmission of the disease. Both germfree and conventional mice with leukemia showed renal glomerulosclerosis. We gratefully acknowledge the assistance of D. M. Robie, E. I. Mynatt, and E. Teeter for maintenance and surveillance of the gremfree colony, J. G. Vi-drine for preparation of the centrifuge pellets, and F. L. Ball for preparation of the samples for electron microscopic examination. The authors also wish to thank Drs. L. Murphy, R. Holdenried, and J. Parker for examining some of the sera for viral antibodies and for supplying us the necessary reagents.

Genetic differences in hemoglobin as markers for bone marrow transplantation in mice.

Summary Both hemoglobin type and red cell serotype seem to be autonomously controlled by the genotype of the nucleated cell from which the erythrocyte is derived. Thus, genetic differences in hemoglobin can be used as markers for bone marrow transplantation in irradiated mice. Hemoglobin typing may be particularly useful where the H-2 markers cannot be used.

RELATIVE ABILITY OF PARENTAL MARROWS TO RE-POPULATE LETHALLY IRRADIATED F1 HYBRIDS

The relative abilities of C57BL and 101 marrow to repopulate the hematopoietic system of lethally x-irradiated mice was determined. The disproportionately greater ability of 101 than C57BL cells to repopulate (C57BL X 101) F/sub 1/ recipients is reported, and data are given on the relative ability of marrow from other strains of mice to repopulate lethally irradiated mice. Consistent with the observation that C57BL marrow is less efficient that 101 marrow is the finding that the number of C57BL cells required to produce functioral long-terra marrow grafts was much larger than the number of 101 cells. Factors that might influence the differential in the growth ability of the two types of marrow are discussed. (H.M.G.)

Effects of immunized parental strain bone marrow on lethally irradiated F1 hybrid mice.

Summary Pre-sensitization of parental strain donor mice against F1 hybrid recipients accentuated the foreign bone marrow reaction caused by injection of parental marrow cells into lethally irradiated F1 recipients. This effect occurred with use of parental strains (101 and C3H) that were histocompatible at the H-2 locus, as well as with those (C57BL and 101) that were histoincompatible at this locus. These results are interpreted to indicate the importance of relative antibody-forming potency of implanted cells, as well as the extent of histocompatibility differences in pathogenesis of the homograft reaction.

The Effect of Presensitization of Parental Donors on Graft-Versus-Host Disease in Irradiated F1 Hybrid Mice

Summary The GVH disease in 1C3F1 hybrid mice following 500 R X-irradiation and injection of normal parent strain spleen cells is mild in terms of mortality, signs, and tissue pathology. Presensitization of the donor with spleen cells of the reciprocal parent strain, however, results in a highly lethal GVH disease. The timing of presensitization before donor use is an important factor in the severity of the resulting GVH disease. Presensitization of the donor seems to require more than 3 days, is near maximum effectiveness at 7 days, persists at this level for many months, and gradually falls off through the life of the donor. After 24 months, sensitized donors still are more effective in producing GVH disease than controls of comparable age.

Immunologically Competent Cells in Adult Mouse Liver Studies with Parent-to-Hybrid Radiation Chimeras

Summary 1. Implantation into irradiated (C57BL X 101) F1 hybrids of viable liver cells from adult donor mice of the parental strains caused a wasting disease followed by death in over 90% of the recipients. 2. This “foreign liver disease” occurred after a sublethal dose of radiation was given to the recipients or after a lethal dose followed by infusion of isologous bone marrow. It did not occur in nonirradiated recipients but occurred in only 26% of sublethally irradiated F1 hybrids infused with isologous bone marrow. 3. In a strain combination in which the F1 hybrid was homozygous at the H-2 locus, and the parents should therefore have been antigenetically relatively compatible, the “foreign liver disease” occurred late after treatment and was enhanced by presensitization of the donor to the reciprocal parent of the hybrid. It was shown that radiation dose and liver cell dose were inter-related factors in determining the development of the disease. 4. Deaths are ascribed to an in vivo immunologic reaction after antibody production by the grafted parental cells against F1 antigens. Nevertheless, there is evidence of a possible immune response by the F1 hybrid against the parent. We are grateful to Mr. W. D. Gude and Mr. T. Mack for the histological preparations.

Inhibition of Foreign Spleen Reaction by Inactivation of Donor Cells with Recipient Antigen

Summary C57BL mouse spleen cells incubated with (C57BL X 101)F1 liver homogenate killed only 17% of sublethally irradiated (C57BL X 101)F1 recipients, whereas when incubated with C57BL liver homogenate or injected without incubation such cells killed 100% of sublethally irradiated (C57BL X 101)F1 recipients within 35 days. Although the immunologically inactivated spleen cells showed a decreased ability to kill, circulating donor-type erythrocytes were found in surviving recipients, indicating repopulation of the bone marrow by surviving graft-derived stem cells. From this, it is inferred that immunologic inactivation did not result from nonspecific destruction of all types of implanted cells.