Age-related characteristics of postradiation regeneration of the blood system

This study was pursued on hybrid (CBA X C57Bl)F1 mice at the ages of 17 and 27 months irradiated at a dose of 4 Gy. It was shown that the postirradiation recovery of haemopoiesis in old mice was the same as in the young (2-3 month-old), and in some respects (for instance, granulocytic and erythroid cells of the bone marrow, and CFUc) the recovery was even more active exhibiting a period of a pronounced hyperregeneration.     

Relation of Infection to Tissue Temperature in Mice Infected with Mycobacterium marinum and Mycobacterium leprae

Intravenous and footpad infections with Mycobacterium marinum and footpad infections with M. leprae were compared in the following mouse strains: A/He, BALB/C, CBA, C3H, C57BL, C57L, DBA, 101, and CFW. The results varied a great deal according to mouse strain used. Intravenous injection of high doses of M. marinum resulted in deaths after 28 days of 100% of strain A/He, and none of strain 101; 27 days after injection, the feet and noses of all strain CBA mice, but few of the C57BL, 101, or CFW mice, were involved. Injection of a small dose of M. marinum into the footpad produced visible disease in 5 days in all of the C57BL and 101 mice, but in not more than 60% of the A/He, DBA, and CFW mice; the average amount of swelling at 17 days varied from 4.40 mm in strain C57L to 0.92 in strain 101. After footpad injection of M. leprae, the average plateau harvests varied from 1.3 x 10(7) acid-fast bacteria in strain CBA to 6.5 x 10(5) in strain C57L. The infections in CBA mice extended from the site of inoculation throughout the foot. The temperature was measured rectally, in the footpad, and in the tail. Analysis of all the results revealed little correlation among the three types of infection. There was a strong negative correlation between the tail temperature and the death rate after intravenous injection of M. marinum, and a strong positive correlation between footpad temperature and plateau harvest of M. leprae.     

Changes in the activity of the oxidative and hydrolytic enzymes of the animal cerebral cortex in the early periods after gamma irradiation and the use of meksamine and the synthetic analog of prostaglandin F2 alpha-estrofan

In experiments with (CBA x C57B1/6)F1 mice it was shown that LDH activity moderately increased 5 min after exposure of the head to 200 Gy gamma radiation. After 60 min, there was a 24.4 per cent decrease in alkaline phosphatase activity and a 24.3 per cent increase in SDG activity. Injected prior to irradiation meksamine precluded the postirradiation increase in SDH and alleviated the postirradiation decrease in alkaline phosphatase.     

Origin of hematopoietic cells in a syngenous and semisyngenous focus of heterotopic hematopoiesis]

Heterotopic hemopoiesis foci were produced by the bone marrow of C57BL/6 or (CBA X C57BL)F1 mice grafted under the renal capsule of (CBAT6T6XC57BL)F1 mice, bearing the chromosomal translocation. The cytogenetic analysis of the hemopoietic cells in the foci 20 to 120 days after the transplantation showed that in 40% of the transplants only the recipient's hemopoietic cells proliferated, whereas the rest were mosaic and contained on the average less than 20% of donor's cells both in the syngeneic and in the semisyngeneic systems. These characteristics remained stable for at least 4 months. The data obtained suggest a single inflow of not less than 10 effective hemopoietic stem cells per graft. The clone stability indicated that during the steady-state hemopoiesis the cell exchange between various regions of the hemopoietic system was not great, if any.     

Genetic aspects of the immunomodulating action of interferon

The data of the study of alpha/beta interferon (IFN) effect in mice of different genotype were presented. CBA mice of H-2k genotype, C57B1/6 mice of H-2b genotype and their hybrid (CBA X C57B1/6) F1 have been used in the experiments. IFN has been injected intraperitoneally in a dose of 100-5000 U/mouse in combination with antigenic stimulation. It was shown that IFN enhanced stem cells migration from bone marrow in CBA, but not in (CBA X C57B1/6)F1 mice. At the same time the splenocytes from CBA mice were more sensitive to inhibition by IFN than splenocytes from C57B1/6 mice. This was found in antibody and immune rosette-formation tests. The effect of IFN on the immune system cells is probably predetermined by the individual genetic characteristics of a mouse strain.     

Effect of estrone on formation of the focus of heterotopic hematopoiesis

The effect of estrone injections on the heterotopic bone marrow organ formation was studied in (C57Bl X CBA)F1 mice by bone marrow shaft transplantation under the kidney capsule. Estrone injections resulted in femur marrow fibrosis, the increase in the weight of femur and heterotopic organ ossicle, drastic reduction in heterotopic organ cellularity. Depression of hemopoiesis in ectopic organ cannot be attributed to mechanical displacement of hemopoietic cells because a newly formed bone cavity under the kidney capsule was not closed. Thus, estrone had a detrimental effect on the creation of microenvironment in the heterotopic organ.     

Molecular manifestations of radiation-induced genome instability: the possibility of chemical modification

The molecular manifestations of radiation-induced genome instability-changes of the DNA structure, the excision DNA repair and the contents of the reactive oxygen forms in bone marrow cells of the repair proficient mice (CBA) and of the repair-defective (101/H) lines in the dynamics up to 185 day after ionizing radiation exposure in the dose of 1.5 Gy were studied. Is was established, that after irradiation in bone marrow cells the descendants with the decreased activity of excision DNA repair and prone to increased changes of DNA structure DHK is arised. The injection of the phenozane in concentrations causing its receptor interaction with cells, did not defend DNA of the bone marrow cells from the radiation injury after the exposure in a sublethal dose, however it exerted influence on long-term changes. Due to the phenosane of the bone marrow cells of the irradiated mice of CBA line exhibited the larger activity in a DNA repair from damages and maintenance of vitality. The bone marrow cells of male mice of repair defective 101/H line, which phenozan was entered before the irradiation, remained unfit to the remuval of DNA damages by the repair, that probably resulted the activations of the program of the maintenance of genome constancy by the apoptosis in the cells--carriers of the structural defects and the cause of animal lethality.     

Cytogenetic effect of mitomycin C and cytosine arabinoside on mice of different genotypes]

Cytogenetic effect of mitomycin C (MC) and cytosine arabinoside (CA) on bone marrow cells of male mice of the strains 101/HY, C57BL/6Y C,3H/SnY and of the (C3HX101) F1 hybrids was studied. The frequencies of cells with chromosome aberrations after the treatment with MC at a 5 mg/kg dose were 54,4%; 41,8%; 40,4% and 26,8% in 101H, B6, C3H/Sn mice and in the F1 hybrids (C3HX101) respectively. The frequencies of cells with chromosome aberrations after the treatment with CA at a 500 mg/kg dose were 25,2%; 17,8%; 10,8% and the 101/H, B6, C3H/Sn mice and in the F1 hybrids (C3HX101) respectively. Both mutagens induced the greatest number of chromosome aberrations in the 101/H strain and the smallest number in the F1 hybrid (C3HX101). A positive correlation was established between the levels of induced and spontaneous chromosome lesions.     

Marked difference in sensitivity to gamma-ray-induced cataract between BALB/c and CBA-C3H strain mice]

Nineteen BALB/c, 14CBA/KI, 12C3H/HeJ and 15 (CBA/Kl x C3H/HeJ) F1 female mice were irradiated with 850 rad gamma-rays and transferred with 10(7) syngeneic bone marrow cells 24 hrs later. The occurrence of cataract was examined in these animals. All the BALB/c mice showed visible lens opacification in both eyes between 113 and 149 days after irradiation. All the animals were autopsied 6 months after irradiation and examined for opacification of their lenses. The proportion of opaque lenses was 100, 7.1, 16.7 and 0% in BALB/c, CBA/Kl, C3H/HeJ and (CBA/Kl x C3H/HeJ) F1 mice, respectively. The results indicate that BALB/c mice are much more sensitive to radiation-induced cataractogenesis than CBA and C3H mice.     

Retroviral particles in radionuclide-induced murine osteosarcomas: mouse strain-related differences

Twenty-six osteosarcomas from strain NMRI mice and twenty-six osteosarcomas from (C3H x 101)F1 hybrid mice were investigated by electron microscopy for the presence of retroviral particles. The bone tumors had been induced by the incorporation of the short-lived bone-seeking radionuclides 224Ra, 223Ra, or 227Th. All of the 26 osteosarcomas from NMRI mice contained retrovirus-like intracisternal type A particles in varying quantities. No type C retrovirus particles could be detected. In contrast, most of the 26 osteosarcomas from (C3H x 101)F1 mice contained budding, immature, and mature type C virus particles predominantly in large quantities. Intracisternal type A particles were also present in all tumors from these mice, but were found only occasionally after extensive search. The mouse strain-related differences in the presence of intracisternal type A particles and type C virus particles in the bone tumors do not provide evidence of an etiological relation of these particles to radionuclide-induced osteosarcomagenesis. Some of the mature type C virus particles observed in osteosarcoma tissue from the hybrid mice were atypical in structure and size. Such pleomorphic particles are probably associated with the spontaneous osteomagenesis which occurs in untreated old (C3H x 101)F1 mice.     

Influence of the maternal effect on allogenic inhibition of hematopoietic stem cells]

Bone marrow cells (0,5-10(6)) of female mice of CBA or C57BL strains were injected intravenously to lethally irradiated CBA, C57BL/6, (femaleCBA X maleC57BL/6)F1 and (femaleC57BL/6 X maleCBA)F1 mice. Spleen of recipients as assayed for colony count on the 9th day after bone marrow transplantation by the method of Till and McCullouch. Stem cells of CBA mice demonstrated failure of allogenic inhibition in (CBA X C57BL/6)F1 hybrid mice and formed the same number of colonies as in the spleen of syngenic recipients. The level of allogenic inhibition of CBA stem cells transplanted to (C57BL/6 X X CBA)F1 hybrid mice was 50%. Bone marrow cells of C57BL/6 mice formed colonies in spleen of (CBA X C57BL/6)F1 mice at least in 20 times less than in syngenic combination. In the transplantation of bone marrow from C57BL/6 mice to (C57BL/6 X CBA)F1 hybrid mice the allogenic inhibition was less pronounced (77-85%) as compared with the transfer of cells to (CBA X C57BL/6)F1 hybrid mice (95%). The sex of a recipient did not influence the number of formed colonies. The different level of allogenic inhibition of parental stem cells can not be explained by the effect of linkage with sex as the female of reciprocal hybrid mice have identical structure of sex chromosomes (X(CBA)XC57BL/6). The data obtained indicate that the maternal effect affects allogenic inhibition of stem cells in parent--F1 system. It is possible that the maternal influence may be determined by cytoplasmic factors of inheritance which affect the expressivity of recessive genes Hh, controlling the inheritance of specific haematopoietic cell antigens.     

Origin of stromal bone marrow mechanocytes according to the results of typing them by isoantigens and chromosomal markers]

The bone marrow of radiochimaeras and heterotopic bone marrow transplants were used to study the origin of precursors of the fibroblasts growing in the monolayer cultures of hemopoietic tissue. In the bone marrow explants of the (C57BL/6 X CBA) F1 mice, in which the CBA bone marrow was transplanted following the lethal irradiation, the fibroblasts grown in the colonies were of recipient origin judging by isoantigens in the reaction of indirect immunofluorescence with the anti-C57BL/6-serum. At the same time in the bone marrow explants from heterotopic transplants (CBA leads to CBA X C57BL/6) the fibroblasts grown in colonies were of donor origin. The cultures of hemopoietic cells of the bone marrow of females heterotopically transplanted in the singenic male (guinea pigs Huston) contained only fibroblasts which were of donor origin judging by sex chromosomes in the metaphase plates of dividing cells. Hence, the bone marrow precursors of fibroblasts do not depend histogenetically on hemopoietic cells and are not replaced at the expense of repopulating cells of the second partner.     

Appearance of foci of hematopoiesis and hematopoietic stem cells in the liver of mice following a single administration of cyclophosphane]

The nidi of hemopoiesis appeared in the liver and the lymph nodes of DBA/2, C57BL/6j and F1 (C57BL/6j X CBA) strains of mice of the 6th day after a single intraperitoneal injection of cyclophosphamide in a dose of 200 mg/kg. This process was accompanied by the appearance of stem hemopoietic cells in the liver. Their maximum number was observed on the 6th and the 9th days. On the 12th day their level decreased, but it still exceeded the one in the animals which received a suspension of normal liver cells. In myelosan exhaustion the pool of the bone marrow and splenic stem cells, the subsequent cyclophosphamide injection failed to induce the appearance of the nidi of hemopoiesis and stem cells in the liver.     

Self-renewal of factor-dependent hemopoietic progenitor cell-lines derived from long-term bone marrow cultures demonstrates significant mouse strain genotypic variation

Long-term bone marrow cultures established from C57Ks/J mice have been shown to spontaneously release endogenous ecotropic RNA type-C virus (retrovirus). C57Ks/J marrow cultures produced granulocyte-macrophage progenitor cells (GM-CFUc) and immature and mature granulocytes for over 45 weeks. In contrast, NIH Swiss mouse marrow cultures failed to release detectable ecotropic virus and generated GM-CFUc and granulocytes for 25–35 weeks and established WEHI-3 conditioned medium (CM) dependent cell lines in vitro and did not establish permanent cell lines. To determine whether viral and/or cellular genes regulated the longevity of C57Ks/J marrow cultures, groups of cultures were established from the marrow of (NIH-Swiss × C57Ks/J) F1 hybrid, F2 hybrid, and (NIH Swiss × C57Ks/J) X NIH Swiss backcross generations. Release of endogenous ecotropic virus was measured weekly in each culture as was the duration of production of immature granulocytic cells and GM-CFUc over a 58-week period. The results demonstrated a complex pattern of inheritance of longevity of long-term in vitro hemopoiesis. Increased longevity did not absolutely correlate with detectable replication of the C57Ks/J N-tropic virus.     

Characteristics of the blood system of inbred and mongrel mice

Peripheral blood and bone marrow indices were studied in inbred (101/H, CC57W, A2G, CBA/Lac, B6WV, C57BL/6, ACR) and mongrel mice. Normal values of the morphological composition of the blood and bone marrow were established. Comparative analysis demonstrated the existence of differences in the mentioned indices not only between the inbred and mongrel mice, but also within the individual animal strains.     

Genetic control of allogenic inhibition of hematopoietic stem cells]

Adult mice of C57BL/6, CBA (CBA X C57BL/6) F1, (CBA X C57BL/6) F2, F1 X CBA and F1 X C57BL/6 strains were lethally irradiated and reconstituted with a constant dose of 3-10(5) C57BL/6 bone marrow cells. At the 9th day after the bone marrow transplantation the colony count was performed in spleen of irradiated recipients. In the spleen of F1, CBA and C57BL/6 mice were registered low (0--8, intermediate (6--18) and high (22-40) numbers of colonies respectively. The segregation ratios in F2 progeny were close to 2 (low): 1(intermediate): 1(high). The segregation ratios in backcross (F1 X CBA) were close to 1(low): 1(intermediate)numbers of colonies. Backcrosses (F1 X C57BL/6) were distributed to low and high numbers of colonies with the ratio 1:1. The number of spleen colonies of males and females was the same in all segregating progeny. The results of hybrid analysis suggest that a single pair of allelic genes is involved in genetic control of allogenic inhibition, and that the resistance (manifestation of inhibition) to C57BL/6 stem cells is conferred by the dominant allele.     

Disorders of bone marrow hematopoiesis long time after the action of cytostatic preparations]

We studied the condition of CBA mice bone marrow hemopoiesis and functional activity of adherent cells 6 months after a single treatment with vinblastine (VB), doxorubicin (DR) and cyclophosphamide (CP) in LD10 dose (6, 22 and 250 mg/kg, respectively). There was a long-term disorganization of bone marrow cell composition. The damage may be attributed to exhaustion of the pools of stem cells and changes in function of the cells formed by hemopoiesis induction microenvironment.     

Spontaneous and induced chromosome aberrations in the bone marrow cells of different strains of mice during aging

Sensitivity of bone marrow cell chromosomes to alkylating agent thiophosphamide and to gamma-irradiation has been studied in the course of ageing in 101/H, A/He, CBA, BALB/c and C57BL/6 mice. The effects of both the kinds of mutagenic treatment and of the genotype of the animals on the age-dependent changes in sensitivity of bone marrow cell chromosomes were found. Following gamma-irradiation under our experimental conditions, no variation in the output of chromosomal aberrations was observed between the strains studied. Following thiophosphamide treatment, aged mice of strains 101/H, A/He and CBA showed an increased chromosome instability as compared to young ones. In C57BL/6 mice the level of induced chromosome aberrations was found to be age-independent. Following thiophosphamide treatment, cells with multiple chromosome lesions were found in the bone marrow. The higher instability of aged animals in some strains was mainly due to a sharp increase in the number of such cells. In the intact mice of all the strains studied no age-dependent increase in the number of cells showing structural chromosome aberrations was observed, while accumulation of aneuploid cells varied with genotype.     

The dynamic morphofunctional state of the adrenals in irradiated recipients following bone marrow transplantation

The influence of syngenic bone marrow transplantation in the dose of 1.10(7) cell/ml upon the adrenal gland state of lethally irradiated recipients at various stages of posttransplantation period during 3 months has been studied at 150 linear F1 (CBA x C57B) male mice. Histological and histochemical studies conducted have shown the transplantation of native and cryopreserved bone marrow of the lethally irradiated recipients to result, depending upon observation time, in undulating change in adrenal gland weight, cortex thickness and lipid content in spongiocytes, which testifies to the certain dynamics of processes, occurring in recipients' adrenal gland.