转基因抗矮花叶玉米对大白鼠骨髓细胞遗传毒性的影响

以SD大鼠为研究对象,研究了转基因抗矮花叶玉米和常规玉米对大白鼠骨髓细胞微核率与染色体畸变率的影响,以观察该转基因玉米对大白鼠可能产生的遗传毒理效应。实验结果表明：饲喂30%和50%转基因玉米日粮组的大白鼠骨髓细胞微核率和染色体畸变率与饲喂常规玉米相比均没有显著差异,而与阳性对照组之间存在极显著差异,这说明转基因玉米与常规玉米对大白鼠骨髓细胞均无遗传毒性。     

氟化钠致突变作用的研究

以昆明种大鼠和小鼠分别进行氟化钠诱发染色体畸变和微核试验,结果表明,在本实验条件下,未 见组化钠诱发动物骨髓细胞染色体畸变率及微核率明显增高。     

用微核试验测定几种茶树昆虫病毒对小白鼠的安全性

用一种快速简便的测定细胞染色体是否被损伤的方法(即微核试验)测定茶毛虫NPV、油茶尺蠖NPV及油桐尺蠖NPV对小白鼠的安全性,通过测定其骨髓中嗜多染红细胞微核的出现频率,证明无论是单独或是混合感染方式均不能测出这些病毒对骨髓细胞染色体有特定的损伤,而阳性对照环磷酰胺所诱发的微核率与其相比极为显著。此法可作为评价昆虫病毒对哺乳动物安全性的一个重要方法。     

云锡矿粉诱发大鼠骨髓细胞染色体畸变的研究

云南锡业公司矿工的肺癌发病率高,矿尘中的砷,铁,铅等金属的潜在致癌性已引起了重视(张辅铭等,1985;云南锡业公司劳动防护研究所,华北辐射防护研究所,1982;云锡劳研所流行病室,1982;孙来华等,1986)。鉴于物质的致癌性与致突变性之间有一定的相关性,我们选用5种云锡矿粉,4种金属化合物,研究它们对大鼠骨髓细胞的遗     

污水和污水土地处理系统中各种水质对华西蟾蜍蝌蚪红细胞微核率的影响

本文使用蝌蚪红细胞微核率作为指示器研究明通河污水和用污水土地处理系统处理后水质的致突变性。蝌蚪在各种水样品中暴露7天。采心脏血制片。在对照组中,微核率分别为4.40‰和4.68‰。1/4明通河污水组诱发蝌蚪的微核率是17.01‰。同对照组相比有明显的差异。     

Co_Y一线照射离体人血诱发的琳巴细胞微核与剂量的关系

微核测定法是细胞遗传学的方法之一, Matte：等Iill首先用啮齿类动物骨髓细胞微核率 来测定疑有诱变活力的化合物,并称之为微核 侧定法。Heddle^[8]推荐使用这种简便而迅速的 方法来衡量染色体损伤。目前,该方法已广泛 用于评价理化因子诱变活力的研究上。辐射诱 发微核这一问题已有不少报道,都证明淋巴细 胞微核率和辐射剂量有密切关系^[1,2]。有的工 作还证明动物的整体照射和离体实验的效应是 一致的。这就提示了一种可能：用离体照射人 血所得到微核率的剂量效应曲线来估计事故条 件下人员所受的剂量。本实验的目的是建立 淋巴细胞微核率与辐射剂量之间关系的刻度 曲线,作为估计事故受照人员剂量的参考指 标。     

大蒜对环磷酰胺诱发的小鼠骨髓细胞微核和姊妹染色单体交换的保护作用

本文以小鼠骨髓嗜多染红细胞的微核率和小鼠骨髓细胞姊妹染色单体交换(SCE)率两个指标,测定大蒜匀浆滤液(GJ)对环磷酰胺(CP)诱变作用的影响。结果表明,用GJ灌胃处理小鼠能降低CP(30mg/kg)诱发的微核率,差异极显著(P<0.01)。用GJ处理小鼠,除了CP高剂量(30mg/kg)外,CP中和低剂量(3mg/kg和0.3mg/kg)所诱发的SCE率均受到抑制,有显著性差异(P<0.05)。表明大蒜有较强的抗诱变能力,具修复染色体损伤和DNA错误复制的功能。     

Mix-G200益生菌粉安全性毒理学评价

目的通过对Mix-G200益生菌粉的安全性毒理学进行研究,为以后的应用提供科学依据。方法采用雌雄小鼠急性毒性试验、小鼠骨髓细胞微核试验、小鼠精子畸形试验、Ames试验和大鼠30天喂养试验等对Mix-G200益生菌粉进行安全性试验研究。结果急性经口毒性试验表明,Mix-G200益生菌粉对雌雄小鼠的急性经口LD50均大于21500 mg/kg,以急性毒性半数致死量毒性分级,属无毒级物质。小鼠骨髓细胞微核试验、小鼠精子畸形试验、Ames试验结果均为阴性。30天喂养试验结果表明,大鼠生长情况良好,血液学检查、生化学检查、主要脏体以及组织学检查结果与对照组相比,差异均无统计学意义。结论 Mix-G200益生菌粉未见遗传毒性,使用Mix-G200益生菌粉是安全可靠的。     

稀土与铜对鲹鲦鱼红细胞微核及核异常的影响

研究了稀土元素镧与铜离子单独或联合作用时,对鲹鲦红细胞微核及核异常的影响。结果表明:处理24h,0.01～0.5mg/L的La3 能显著降低红细胞微核及核异常的发生,不具遗传毒性.但当浓度为1～50mg/L时则能诱发红细胞微核及核异常的发生,与对照组相比,相差显著或极显著(P<0.05或P<0.01),具较强的遗传毒性;铜能显著诱导红细胞微核及核异常的发生;联合作用时,微核率及核异常率明显低于Cu2 而高于La3 单独作用时的微核率和核异常率,提示一定浓度的稀土元素能减轻其他重金属元素引起的遗传毒性。     

玉米赤霉烯酮在小鼠体内的致突变性研究*

用小鼠骨髓细胞微核试验和染色体畸变试验评价了赤霉病麦毒素之一玉米赤霉烯酮的体内致突变效应。玉米赤霉烯酮的试验剂量为0,0.1,1.0,10.0,100.0mg/kg体重,以环磷酰胺为阳性对照。实验结果表明,玉米赤霉烯酮各试验剂量组的微核发生率和染色体畸变率与阴性对照组相比均无显著性统计学差异,亦未发现有明显的性别差异。     

频繁使用染发剂对小鼠染色体畸变率影响的研究

研究了多次接触７ 种染发剂对不同组小鼠骨髓和生殖细胞染色体畸变率的影响。结果发现, ７ 种染发剂均导致出现较高的染色体畸变率,３ 种能引起小鼠骨髓细胞染色体畸变率显著上升, 其中以粉末状染发剂的影响最为严重。４ 种染发剂对进行生殖细胞染色体畸变实验的小鼠均产生显著影响, 尤以氧化型染发剂最为明显。     

State of several rat hematopoietic organs following total and subtotal irradiation and after bone marrow autotransplantation]

Hemopoiesis was studied in rats after x-ray irradiation. Lethal doses of 800--820 R were applied totally, with screening the shin and with subsequent autotransplantation of bone marrow taken from noninjured hemopoietic tissue. Survival of the animals and status of hemopoietic organs (quantitative indices of the peripheral blood, bone marrow and the spleen, as well as morphological changes in hemopoietic organs) served as tests. All totally irradiated animals died by the 20th day, the 30th day in the group of screened animals 32% survived, in the group with autotransplantation of bone marrow--62%. According to the indices studied restoration of hemopoiesis proceeded more quickly and completely in the group with autotransplantation of bone marrow and somewhat slower in the group with screening the shin (but without autotransplantation); this was accompanied by repopulation of bone marrow comparing with the totally irradiated animals. Restoration of the hemopoietic organs was followed by a comparatively rapid increase in the number of myeloid cells, while the number of lymphoid cells increased more slowly.     

Linked unresponsiveness: early cytokine gene expression profiles in cardiac allografts following pretreatment of recipients with bone marrow cells expressing donor MHC alloantigen

Linked unresponsiveness operates to induce specific unresponsiveness to fully mismatched vascularized allografts in recipients pretreated with anti-CD4 antibody and syngeneic bone marrow cells expressing a single donor MHC class I alloantigen. The aim of the study was to evaluate early post transplant cytokine expression in allografts where linked unresponsiveness was required for long term graft survival. CBA (H2(k)) mice were pretreated with CBK (H2(k)+K(b)) bone marrow cells under the cover of anti-CD4 antibody 28 days before transplantation of a CBK or a C57BL/10 (H2(b)) cardiac allograft. In both cases graft survival was prolonged (MST=100 days). Intragraft expression for interferon (IFN)-gamma, interleukin (IL)-2, IL-4, IL-10, IL-12(p40), IL-18, iNOS, transforming growth factor (TGF)-beta(1) and C-beta was determined on day 1.5, 3, 7 and 14 after transplantation. Whereas rejecting allografts displayed a sharp peak in IFN-gamma, IL-2, IL-4 and IL-10 expression, non-rejecting allografts were characterized by an initial TGF-beta(1) and IFN-gamma production. An increasing IL-4 expression towards day 14 was a unique feature of linked unresponsiveness. All non-rejecting allografts were characterized by an increasing IL-12(p40) production towards day 14. In summary, the early cytokine expression pattern in allografts after bone marrow induced operational tolerance is influenced by the quantity of donor alloantigens expressed on the graft as well as on the bone marrow inoculum.     

小鼠体内脾脏,骨髓及精原细胞姐妹染色单体交换的比较研究

本文对几种化学诱变剂诱发小鼠体内脾脏、骨髓和精原细胞的SCE进行了比较研究,同时分析了几类常见化合物在小鼠脾脏细胞中诱发SCE的活力。结果显示诱变剂在脾脏细胞中诱发SCE比骨髓和精原细胞敏感。几类化合物都能显著地诱发小鼠脾脏SCE的增加,与对照相比差异显著(P<0.05)或极显著(P<0.01),说明利用小鼠脾脏细胞检测环境诱变物是相当灵敏的。     

The effect of bone marrow depletion on prostaglandin E-producing suppressor macrophages in mouse spleen

The i.p. injection of Corynebacterium parvum (CP) into CBA/J mice effected increases in macrophage colony-forming cells (M-CFC) when spleen cells were cultured with L cell culture filtrate as a source of colony-stimulating factor. Significant increases in phagocytic macrophages (M phi) with Fc receptors for IgG2a and IgG2b immune complexes were additionally noted among the spleen cells in these mice. These M phi effectively inhibited Con A-induced lymphocyte proliferation, probably reflecting a 10-fold increase above normal controls in prostaglandin E to 47 ng/3 X 10(6) spleen cells/ml. To determine whether the suppressor M phi are immediate derivatives of splenic M-CFC, we tried to induce suppressor M phi by the injection of CP into mice depleted of bone marrow M-CFC by the earlier administration of the bone-seeking isotope, 89Sr. This procedure reduced M-CFC in the bone marrow to less than 1% of normal for more than 30 days. Monocytes in the blood fell to 5% of normal by day 10 and were 30% on day 30. Levels of resident peritoneal M phi showed relatively little change in this period. By contrast, splenic M-CFC increased to 20-fold higher than the "cold" 88Sr controls. CP-induced suppressor M phi activity, however, was sharply reduced in 89Sr marrow-depleted mice on day 10, despite the striking increase in M-CFC. There was a threefold increase in the number of phagocytic M phi binding IgG2a immune complexes, with no significant increase in IgG2b binding M phi. The kinetics of recovery of suppressor M phi activity showed that on days 20, 30, and 50 after 89Sr injection the activities reached 20%, 30%, and 70% of the "cold" control, respectively, and correlated with the recovery of significant levels of M-CFC in the bone marrow. Taken together, these observations suggest that splenic M-CFC are not an immediate source of PGE-suppressor M phi in vivo. It appears more likely that the CP-inducible suppressor M phi, in particular, originate from radiosensitive bone marrow cells or require for differentiation a microenvironment provided by bone marrow cells. The data also suggest that the expression of the Fc gamma 2b receptor and of suppressor activity by CP-induced splenic M phi are related phenomena.     

Ontogeny of IgE-bearing lymphocytes in the rat

IgE-bearing lymphocytes were detected by immunofluorescence in the spleen of neonatal Hooded Lister strain rats within 24 hr after birth. The same cells were detected in the bone marrow as early as the 4th day after birth. Both fetal spleen and liver obtained 1 day before birth contained IgM-bearing cells but no detectable IgE-bearing cells. The proportion of IgE-bearing cells in the spleen and bone marrow increased during the neonatal period and reached an adult level within 3 to 4 weeks after birth. In adult Hooded Lister rats, IgE-bearing cells were 3 to 6% of total spleen cells and 1.5 to 2.2% of bone marrow cells. Most of the IgE-bearing cells from bone marrow cells. Most of the IgE-bearing cells from both newborn and adult animals carried IgM determinants on their surface. Capping experiments showed that epsilon chain determinants and mu chain determinants belonged to separate molecules. IgG2a-bearing lymphocytes were detected in the neonatal spleen as early as the 4th day after birth, but a significant number of these cells was not detected in the bone marrow until the 4th week. In newborn spleen the percentage of IgE-IgM double bearing cells was higher than that of IgG2a-bearing cells.     

COMPARTMENTS AND CELL FLOWS WITHIN THE MOUSE HAEMOPOIETIC SYSTEM II. ESTIMATED RATES OF INTERCHANGE

Part-body irradiated CBA mice were injected with CBA-T6 bone marrow. In this way a predominantly donor population was established in the femora while the marrow of the humeri remained largely (average 94 %) of host origin. In animals examined cytologically up to 2 years later, no tendency was observed for the proportion of donor cells in the humeri to increase. Splenectomy had no effect on this. When femoral bone marrow from the experimental mice was injected into lethally (whole-body) irradiated recipients, cells originating from the primary host repopulated the lymph nodes to a disproportionate extent. Equilibration between the cell populations of femora and humeri occurred after re-exposure to 600 rad whole-body irradiation, but not after 100 rad or 350 rad; thus, regeneration of damaged bone marrow involved a significant contribution from extrinsic stem cells only after the highest dose of radiation. The data are compatible with an inflow of at most ten effective stem cells per humerus per day from the blood, and suggest a much lower figure. This means that few if any of the stem cells of peripheral blood enter the bone marrow and found haemopoietic clones. Evidence is adduced for the existence of a proliferating lymphoid sub-population in the bone marrow, contributing some 5–10% of the observed mitoses. The mitotic cells in the lymph nodes are replaced from marrow-derived progenitors at an estimated rate of 4–5 %/day. The relevant data for the thymus are more variable, but suggest an average figure of 8–11 %/day. Earlier data from mouse parabionts suggest a lower rate of inflow to the thymus.     

The characteristics of endothelial progenitor cells derived from mononuclear cells of rat bone marrow in different culture conditions

Endothelial progenitor cells (EPCs) derived from bone marrow are known to be heterogeneous. In this study, we tried to find favorable conditions that induce the differentiation of mononuclear cells (MNCs) from bone marrow into EPCs. The differentiation capacity of MNCs from rat bone marrow was investigated in different conditions, such as different media, different induction times and different culture surfaces. The cell morphology and endothelial biomarkers associated with differentiated MNCs were studied. Our results indicated that MNCs cultured in EGM-2MV (Endothelial cell basal medium-2, plus SingleQuots of growth supplements) developed a bursiform shape, a late EPC-like morphology, while MNCs cultured in complete medium (CM, M199 with 10% FBS, 20 ng/mL VEGF and 10 ng/mL bFGF) showed a spindle shape, an early EPC-like morphology. Cells of both morphologies were able to incorporate DiI-ac-LDL and bind lectin in vitro. MNCs cultured in EGM-2MV exhibited a higher proliferation rate and higher eNOS expression than MNCs cultured in CM. MNCs cultured in EGM-2MV had the ability to form tubes on Matrigel. Flow cytometry results indicated that CD133 expression was highest at day 12 and that the greatest number of cells positive for both FLK-1 and CD133 appeared at day 20 from cells cultured in dishes without fibronectin coating. In addition, the expression levels of CD133, CD31 and FLK-1/CD133 were not significantly different between cells of different shapes. Our experiments suggest that MNCs from bone marrow can be differentiated into late EP-like cells in EGM-2MV, which have the ability to rapidly proliferate. These MNCs can also be differentiated into early EP-like cells in CM. Additionally, fibronectin may not be necessary for the differentiation of EPCs to mature ECs after three generations. Differentiated MNCs from bone marrow in EGM-2MV have the characteristics of EPCs, although the expression levels of EPC markers were lower than previously reported.     

Induction of gene mutations by 5-(2-chloroethyl)-2'-deoxyuridine (CEDU), an antiviral pyrimidine nucleoside analogue

5-(2-chloroethyl)-2'-deoxyuridine (CEDU) had been developed for the treatment of herpes simplex infections. In the Salmonella reverse mutation test, the compound was found to be mutagenic in strains TA1535 and TA102 at very high concentrations (> or =2500 micro g/plate), both with and without S9-mix. The mutagenic potential of CEDU was further investigated in vivo and in vitro. It did not induce DNA repair in rat hepatocyte primary cultures, and was negative in the micronucleus test in V79 cells and in the comet assay in human leukocytes. In vivo, CEDU was negative in the bone marrow micronucleus test in CD1 mice. The mouse spot test provided a clearly positive result. Treatment of mice on day 9 of pregnancy with 2000 mg/kg resulted in 5.9% of the F1 animals having genetically relevant spots, whereas the corresponding vehicle control group had a spot rate of 1.9%. Since these data clearly identified CEDU as an inducer of gene mutations in vivo, this potential was further investigated in lacZ transgenic Muta Mouse. Six female animals were treated daily on five consecutive days with 2000 mg/kg/day and sacrificed, after a treatment-free sampling time, 14 days later. The data showed a clear increase in the mutant frequency in the bone marrow, the lung and in the spleen. CEDU is an exception in the group of nucleoside analogues, because it was found to be a strong gene mutagen and, in contrast to the other compounds of this group investigated so far, had no considerable clastogenic effects.