Effect of increased natural radioactivity on bone marrow morphology of Microtus oeconomus pall

It was established that Microtus oeconomus Pall. living in territories with the increased radiation background exhibit focal myeloid hyperplasia in the bone marrow, changes in the maturation indices of erythroid and myeloid elements, increase in number of karyocytes due to the increase in their mitotic activity. It is suggested that activation of vole haemopoiesis is an adaptive reaction of the organism to the effect of the radioecological factor.     

Effect of low doses of ionizing radiation on bone marrow cell chromosomes in Microtus oeconomus Pall

It is shown that Microtus oeconomus Pall. living in conditions of enhanced natural radioactive background do not suffer from the increased radioactivity with regard to the induction of cytogenetic disturbances in bone marrow cells. It is supposed that these animals are more radioresistant than Microtus oeconomus Pall. living in vivaria.     

Cytogenetic action of a number of monohydric alcohols on bone marrow cells in rats

Single administration of monohydric alcohols to rats in equitoxic doses corresponding to 1/5 LD50 results in a cytogenetic effect which depends on a chemical structure of the alcohol molecule. The isomers are less active chemicals than the normal counterparts.     

Cytogenetic research on micropopulations of the root vole (Microtus oeconomus Pall.) living under various radioecological habitat conditions

Percentage of aneuploid cells and that of cell with chromosome aberrations in Microtus oeconomus Pall. living in areas with the enhanced radiation background (the dose of external radiation is 50 times and that of internal irradiation of bone marrow by incorporated 226Ra 10 times higher than the controls) exceeds significantly (p less than 0.05) the control values. It is concluded that mutations occur in the experimental animals more frequently than in the controls.     

Cytogenetic effects of dacarbazine on mouse bone marrow cells in vivo

The mutagenicity of dacarbazine was assayed in an in vivo test utilizing mouse bone marrow cells. The dose rates used in the experiments were computed according to the standard surface area of the mouse and were proportional to the human dose rate. These were 0.27, 0.44 and 0.60 mg/30 g body weight, each given twice daily at an interval of not less than 6 h. The duration of drug treatment was 24, 48 and 72 h. This alkylating agent proved to be mitodepressive and produced a 3-fold reduction in the mitotic index. The drug also induced chromosome anomalies mainly in the form of chromatid gaps and breaks. These anomalies were proportional to dose rate and duration of drug treatment.     

Cytogenetic activity of the pesticide, Valexon, and its effect on the mutability of mouse bone marrow cells

Cytogenetic activity of organo-phosphorous insecticide, Valexon, and its influence on the mutability of mice bone marrow cells were studied. Mice repeatedly treated with low doses of Valexon are determined to possess a higher bone marrow cytogenetic sensitivity to the action of the known mutagen rubomycin (daunomycin).     

Cytogenetic changes in the bone marrow cells of long-term irradiated rats]

The occurrence and characteristics of the chromosome structural changes in femur bone marrow cells under continuous irradiation with the exposure rate of 50 R/day within 90 days was followed. The 25% increase in the chromosome aberration frequency was observed within 7 days of the irradiation, and then the aberration rate was constant up to the end of the irradiation (90 days).     

Cytogenetic effects of ribavirin on mouse bone marrow

The micronucleus test and mitotic chromosome analysis were used to study the in vivo mutagenic activity of ribavirin on bone marrow cells of Swiss albino mice. To determine the incidence of micronuclei, mice were injected i.p. twice, at an interval of 24 h. with the drug at doses of 20, 100 and 200 mg/kg. Animals were killed 6 h after the second dose and bone marrow was examined for the presence of micronuclei in developing erythrocytes. Ribavirin significantly (P less than 0.05) induced micronuclei in polychromatic erythrocytes at all doses. A study was conducted to investigate the cytogenetic effect of the drug on mitotic chromosomes. Ribavirin at 200 mg/kg/day was administered to mice for 3 and 5 days. Repeated treatment with the high dose of ribavirin produced a highly significant (P less than 0.02) increase in abnormal metaphase spreads. The results indicate that ribavirin is mutagenic to bone marrow cells of mice as evaluated by the micronucleus test and by chromosome analysis.     

Cytogenetic damage of bone marrow cells produced by chronic alcohol consumption

Pair-feeding of rats with nutritionally adequate liquid diets containing 36% of total energy either as ethanol or as additional carbohydrate (in the controls) resulted in blood ethanol concentrations similar to those observed in alcoholics. Alcohol feeding for six weeks increased the frequency of micronuclei in bone marrow erythrocytes, an index of chromosomal damage in precursor cells. This was associated with bone marrow hypoplasia and erythrocyte macrocytosis, alterations commonly found in alcoholics. By contrast, acute ethanol administration produced no changes in the bone marrow. Cytogenetic damage of stem cells could lead to alterations persisting after alcohol withdrawal beyond the life span of effector cells.     

甘肃鼢鼠和根田鼠听域研究

用电生理学方法对甘肃鼢鼠和根田鼠的听性脑干反应(ABR)的反应阈值做了测定,以确定甘肃鼢鼠和根田鼠听域.结果 表明甘肃鼢鼠听力敏感频率为12 kHz,根田鼠的听力敏感频率为16～32 kHz.甘肃鼢鼠和根田鼠听性脑干电位测定结果表明地下鼠和地面鼠低频高频听力阈值存在差异,地下鼠对中低频声波敏感.     

根田鼠视网膜的胚后发育

视觉对动物的生活习性尤其是取食具有重要意义。本文对根田鼠视网膜的胚后发育进行了研究,结果表明:出生3d内根田鼠视网膜分化程度较低,神经节母细胞层尚未分化,占据了视网膜层的一半以上;5日龄时,外网层开始出现;6日龄时,外网层开始清晰,外核层与内核层更加清晰;18日龄时,视网膜结构与成年根田鼠结构相似,各层结构清晰可见。测量了神经节细胞层和外核层的细胞密度以及核层厚度,结果表明:随着个体发育,外核层细胞层厚度及细胞密度不断增加;而神经节细胞层厚度及细胞密度不断减少。与褐家鼠、黑线姬鼠、大仓鼠、棕色田鼠、甘肃鼢鼠、达乌尔黄鼠、岩松鼠视网膜相比,根田鼠视网膜结构介于夜行性与昼行性鼠类之间[动物学报52(2):376-382,2006]。     

The humoral nature of the colony-stimulating action of bone marrow cells on stromal colony formation in bone marrow cultures

In 24 hours adherent marrow cell cultures (AMCC) were represented by single stretched fibroblasts. In non-feeder-supplemented AMCC most of the CFU-f remained single fibroblasts or passed through 1-3 cell doublings [correction of dudlings]. The colony stimulating activity of irradiated marrow cells was found to be diffuse across the Millipore filter, which seems to indicate that haemopoietic marrow cells produce a colony stimulating factor which is required for triggering the CFU-f from the Go-period of the cell cycle into cell proliferation.     

Cytogenetic studies in bone marrow transplant recipients

Chromosome studies were performed in 24 patients who underwent allogeneic bone marrow transplantation (BMT) for severe aplastic anaemia (8), chronic myeloid leukemia (5 in chronic, 2 in accelerated phase and 1 in lymphoid blast crisis), acute myeloid leukemia (6), acute lymphoblastic leukemia in relapse (1) and Hodgkin's disease (1). Donor-cell type engraftment was demonstrated in 21 patients: in all 17 sex-mismatched transplants and - as demonstrated by reconstitution with Ph-negative cell populations - in 4 CML patients with a sex-matched donor. Recipient-type mitoses were seen in the bone marrow of 5 cases (1 SAA, 3 CML, 1 AML) after transplantation. They were only observed on one occasion in patients with SAA (4 of 25 on day 33) and AML (44 of 50 on day 14). Despite the continued demonstration of some Ph-positive mitoses in 3 patients with CML up to day 28, 323 and 451 after BMT, respectively, all surviving CML patients are still in complete haematological and clinical remission. So far the significance of these cytogenetically abnormal persisting host cells remains unknown.     

Cytogenetic changes of mesenchymal stem cells in the neoplastic bone marrow niche in leukemia

Background

Bone marrow mesenchymal stromal cells (BM-MSCs) are an essential cell type in the hematopoietic microenvironment. The question of whether MSCs from patients with different leukemias have cytogenetic abnormalities is controversial. In this study, we attempted to review the cytogenetic profiles of MSCs in patients with leukemia, and verify whether these profiles were related to different ex vivo culture conditions or to chronic or acute disease states. This information could be useful in clarifying the origin of MSCs and developing clinical applications for this cell type.

Methods

A systematic literature search was performed using the PubMed search engine. Studies published over the past 15 years, i.e., between 1995 and January 2015, were considered for review. The following keywords were used: “cytogenetic,” “leukemia,” “bone marrow,” and “mesenchymal stromal cells.”

Results

Some studies demonstrated that BM-MSCs are cytogenetically normal, whereas others provided evidence of aberrations in these cells

Conclusions

Studying cytogenetic changes of MSCs in a variety of leukemias will help researchers understand the nature of these tumors and ensure the safety of human stem cells in clinical applications.

     

Foraging behaviour of the root vole Microtus oeconomus in fragmented habitats

The effect of habitat fragmentation on spatial foraging behaviour in the root vole Microtus oeconomus was investigated in seven experimental populations. Four of the populations were established in large, continuous blocks (30 × 95 m) of meadow habitat (treatment plots), whereas the three remaining populations had six small rectangular habitat fragments (30 × 7.5 m) with variable inter-fragment distances (control plots). Both the small habitat fragments and the large continuous habitat were embedded in a non-habitat matrix area which was regularly mowed. Half-way through the study period, the continuous habitat in treatment plots was destroyed by mowing to give a configuration identical to the control plots. Dyed bait placed at the edges and in the interior of habitat fragments as well as in the matrix area was used to reveal differential use of these areas for foraging. Animals in the small-fragment plots fed more than expected along the edges, while edges were used according to availability in the large blocks of continuous habitat. In the fragmented plots, the frequency of foraging in the matrix decreased with increasing distance to the fragment border and with increasing inter-fragment distances. Furthermore, the frequency of use of more than one habitat fragment in individual foraging ranges decreased with increasing inter-fragment distances. Reproductively inactive animals of both sexes fed more often along habitat edges than reproductively active animals. Reproductively active females fed exclusively in one habitat fragment, whereas inactive animals and especially reproductively active males frequently included more than one fragment in their foraging ranges. The only effect of habitat destruction was less foraging in the matrix habitat in the post-destruction treatment plots compared to the permanently fragmented control plots. This was probably an effect of different matrix quality. Root voles in these experimental populations forage in edge and matrix habitat with great risk of becoming victims to predation, and the results are interpreted in this context. Received: 19 August 1998 / Accepted: 30 June 1999     

Palatability of silver birch seedlings to root voles Microtus oeconomus

We used laboratory feeding trials to test the palatability of silver birch Betula pendula seedlings to root voles Microius oeconomus Seedlings of two B pendula families (A and B) were grown in growth chambers on three soil types and under two light intensities. Seedlings from family A grew taller and had more resin droplets on their bark than seedlings from family B The more light or nutrients the seedlings received the taller they grew and the more resm droplets they had on their bark We offered 10 root voles both basal and top 5–10 cm segments of winter-dormant seedlings one treatment at a time (no-choice arrangement) in a random order The seedlings grown on low-fertility soil were eaten more than those grown on non-fertilized or fertilized peat The top segments of seedlings grown in low light were slightly more eaten than those grown in high light Birch family did not have any effect on the consumption Consumption correlated negatively with the amount of resin droplets on the bark when the seedling material was compared over different treatments These results indicate that root voles would prefer young birch seedlings that have low amount of resin droplets on the bark and that grow in poor soils or under low light conditions