Chromosomal aberrations in bone-marrow cells of mice given a normal or a calcium-deficient diet supplemented with various heavy metals

Mice kept on a normal (1.1% calcium) or low-calcium (0.03%) diet were exposed for one month to zinc chloride (0.5% Zn), lead acetate (0.5% Pb) or cadmium chloride (0.06% Cd) or to a mixture of these salts at half the above concentrations. These concentrations, given in a poor calcium diet, represent an LD 50/30 days. After the mice were killed bone-marrow cells were assayed for chromosomal aberrations, and serum calcium was determined. Chromosomal aberrations were detected in the mice maintained on a low-calcium diet and exposed to lead, zinc or a mixture of lead, zinc and cadmium. The possible mechanism for the synergistic action on genetic effects of the lack of calcium and intoxication by heavy metals are discussed, and it is recommended that routine attention be given to the state of calcium metabolism in heavy-metal intoxication.     

Differences in antibody production after adoptive transfers of syngeneic and allogeneic spleen cells to irradiated mice

Immunologically competent spleen cells from syngeneic or allogeneic donors were transferred to supralethally irradiated mice. At the same time, or 72 h after transfer, sheep red cells were administered intraperitoneally to the hosts. Five days after administration of the sheep red cells, antibody production was determined in host spleen fragments by the method of haemolysis in agarose. It was found that an incompatible allogeneic environment markedly stimulated proliferation of the donor cells and that proliferation of clones of cells reacting specifically to sheep red cells by antibody production was also stimulated.     

Correlation of spleen colony formation and changes in spleen weight during its recovery in irradiated mice

In experiments on (CBA X C57Bl)F1 and BALB/c mice it was shown that with the spleen mass increasing, due to exo- and endorepopulation, during the postirradiation regeneration of the spleen, the number of splenic colonies also increases to a certain level. When the spleen mass reaches 1/3 of that lost after irradiation the number of discrete colonies decreases. When the spleen mass is restored to about 1/2 solitary colonies do not form at all. The spleen mass can considerably exceed the normal level in conditions of intensive repopulation.     

Reconstitution of the thymus dependent area in the spleen of lethally irradiated mice

Cell and Tissue Research - To study the submicroscopical morphology of the microenvironment for T-lymphocytes in the spleen, mice were lethally X-irradiated and injected intravenously with...     

Repopulation of spleens of irradiated mice after injection of spleen cell subpopulations

Haemopoietic stem cells present in the spleen of adult mice were analysed by grafting X-irradiated animals with polystyrene-nonadherent (NABS) and polystyrene-adherent (ABS) B-enriched splenocytes from syngeneic donors. The progeny of the haemopoietic stem cells present in NABS and ABS subsets were studied with respect to size, surface markers, and response to mitogens and antigens. Ninety-six per cent of the precursors of the myeloid cell lineage (CFU-S) were present in the NABS fraction (50-fold enrichment). The presence in NABS of progenitors of functional T and B lymphocytes was also demonstrated. Twelve days after grafting with NABS, more than 80% of the recipient splenocytes were large and nonadherent granulocyte-like cells. These cells had surface similarities with NABS from normal mice, since both populations reacted with peanut agglutinin and with a rabbit anti-NABS (RAN) serum.     

Repopulation of spleens of irradiated mice after injection of spleen cell subpopulations

Abstract. Haemopoietic stem cells present in the spleen of adult mice were analysed by grafting X-irradiated animals with polystyrene-nonadherent (NABS) and polystyrene-adherent (ABS) B-enriched splenocytes from syngeneic donors. The progeny of the haemopoietic stem cells present in NABS and ABS subsets were studied with respect to size, surface markers, and response to mitogens and antigens. Ninety-six per cent of the precursors of the myeloid cell lineage (CFU-S) were present in the NABS fraction (50-fold enrichment). The presence in NABS of progenitors of functional T and B lymphocytes was also demonstrated. Twelve days after grafting with NABS, more than 80% of the recipient splenocytes were large and nonadherent granulocyte-like cells. These cells had surface similarities with NABS from normal mice, since both populations reacted with peanut agglutinin and with a rabbit anti-NABS (RAN) serum.     

Radiosensitivity of pluripotent stem cells detectable by cloning in the spleen of irradiated mice

It was shown that the dose--effect curves describing the radiosensitivity of CFUc of the bone marrow irradiated in vitro (0.04-3.7 Gy) and treated with normal rabbit serum (NRS) and anti-mouse-brain serum (AMBS) has two differently sloping portions indicating that two CFUc populations differing in radiosensitivity are present in the bone marrow. D0 was 0.93 Gy after irradiation with doses of 0.04-0.75 Gy and treatment with NRS, and 0.33 Gy after incubation of the bone marrow with AMBS. The addition of thymus cells "straightened" the dose--effect curve for the bone marrow treated with AMBS: in this case D0 was 1.81 Gy exceeding considerably the values of D0 for intact bone marrow. The CFUc population is suggested to be heterogeneous in radiosensitivity.     

The effect of soluble glucan derivates on spleen colony-forming units in sublethally irradiated mice

We examined the effects of 5 soluble derivatives of yeast glucan on the formation of exogenous (CFU-S) and endogenous (E-CFU) colony-forming units in the spleens of sublethally irradiated (⁶⁰Co, 6.5–7.0 Gy) mice of two inbred strains. For the estimation of CFU-S, glucans were administered intravenously either to donors or recipients of spleen cells 24 h prior to irradiation or removal of the spleen. The number of CFU-S was increased when both the donors and recipients were treated with glucan; the highest increase was obtained with glucans S, P and K. All glucan preparations increased significantly also the number of E-CFU even when administered 90 min after irradiation. There exist differences in the response to the stimulatory effect of glucans among individual mouse strains. Thus, for example, the stimulatory effect of glucan KM on the E-CFU number was significantly more pronounced in strain A/Ph than in strain C57B1/6.