Effects of pinocembrin on the initiation and promotion stages of rat hepatocarcinogenesis

Pinocembrin (5, 7-dihydroxyflavanone) is a flavanone extracted from the rhizome of Boesenbergia pandurata. Our previous studies demonstrated that pinocembrin had no toxicity or mutagenicity in rats. We here evaluated its effects on the initiation and promotion stages in diethylnitrosamine-induced rat hepatocarcinogenesis, using short- and medium-term carcinogenicity tests. Micronucleated hepatocytes and liver glutathione-S-transferase placental form foci were used as end point markers. Pinocembrin was neither mutagenic nor carcinogenic in rat liver, and neither inhibited nor prevented micronucleus formation as well as GST-P positive foci formation induced by diethylnitrosamine. Interestingly, pinocembrin slightly increased the number of GST-P positive foci when given prior to diethylnitrosamine injection.     

Micronucleus Expression and Acute Leukemia Prognosis

The micronucleus frequency (MNF) in peripheral blood lymphocytes (PBL) is a biomarker of chromosomaldamage and genome instability in human populations.The relationship of micronucleus frequency with prognosisof patients with acute leukemia is not clear. We therefore investigated MNF in mitogen-activated peripheralblood lymphocytes from patients with hematologic diseases and solid tumours. Patients included 50 with acuteleukemia, 49 diagnosed with myelodysplastic syndrome (MDS), 54 with benign blood diseases, and 45 with solidtumours, examined with 50 healthy controls. The mean MNF was significantly higher in cases of hematologicdiseases and solid tumor patients than in healthy controls (P<0.001). There was no evident difference betweenMNF in the acute leukemia (7.15±2.18) and solid tumor groups (7.11±1.47), but both were higher than in the MDSgroup (5.12±1.29) and benign blood diseases group (3.08±1.08). Taking 7.15‰, the average MNF of the acuteleukemia group as standard, and dividing 50 cases of acute leukemia patients into high MNF group (MNF≥7.15‰)and low MNF group (MNF<7.15‰). The overall response (complete remission + partial remission) rates of thelow MNF group were significantly higher than in the high MNF group (P=0.001). The high MNF group furthershowed lower overall survival rates than the low MNF group. MNF expression and progression-free survivalseemed to have a opposite relationship, with a correlation coefficient of -0.702. These data indicate that MNFin peripheral blood lymphocytes is important for evaluation of prognosis of acute leukemia patients, and it canreflect progression of disease to a certain degree.     

电子垃圾污染物对人类遗传毒性的初步研究

目的： 对长期居住在天津市某镇电子垃圾处理较集中的3个村庄的居民进行细胞遗传学研究,分析电子垃圾污染物对人体的遗传损伤效应。方法：在电子垃圾处理区居民中随机选择171位村民作为暴露组,进行染色体畸变 (CA)和胞浆阻滞微核 (CBMN)分析,并进行单细胞凝胶电泳检测DNA损伤。选取与该镇毗邻区域且从未接触电子垃圾处理的30位村民 (男女各半)作为对照组。暴露组按照性别和年龄分组,分别观察不同性别和年龄组的CA、CBMN和DNA损伤水平。结果：暴露组染色体总畸变率为5.50%,与对照组(1.70%)差别有统计学意义 (P<0.01);暴露组微核率为16.99‰,对照组为3.47‰,差异有统计学意义 (P<0.01);单细胞凝胶电泳检测显示暴露组尾部DNA百分含量 (TDNA,%)、尾矩 (TM)、Olive尾矩 (OTM)较对照组均显著升高 (P<0.01)。染色体畸变率、微核率和DNA损伤水平女性均明显高于男性 (P<0.01),而在各不同年龄组间未见明显差异 (P>0.05)。结论：电子垃圾污染物是潜在的遗传诱变剂,能够造成污染地区人群的细胞遗传学损伤,不能忽视其对当代及其子代健康的有害影响。     

白血病患者外周血淋巴细胞微核分析

目的：应用微核分析技术检测初诊白血病患者的遗传损伤。方法：应用细胞周期阻断法检测54例初诊白血病患者(CML 11例,AML-M1 7例,AML-M2 6例,AML-M3 4例,AML-M4 2例,AML-M5 4例,AML-M6 2例,ALL 18例)和30例健康人外周血,以微核率(micronucleus rate,MNR)、微核细胞率（micronucleus cell rate,MCR）、核芽(nuclear bud,Bud)率、核质桥(nucleoplasmic bridge,NPB)率、核分裂指数(nucleus division index,NDI)、凋亡细胞(apoptotic cells,AC)率结合染色体中期分析、融合基因和基因重排检测作为染色体损伤指标分析初诊白血病患者的遗传损伤。结果：54例初诊白血病患者外周血的MNR\[（17.368±1.305）‰ vs（7.368±0.844）‰\]、MCR\[（15.418±1.212）‰ vs（5.887±1.101）‰\]、Bud率\[（8.142±0132）% vs（0.404±0.404）%\]、NPB率\[（5.724 ±0.874）% vs（0.034±0.034）%\]、NDI\[（1.722±0.062）% vs（2.282±0324）%\]、AC率\[（2.167±0.333）% vs（0.167±0.667）%\]、异常染色体检出率(24.00%)、融合基因或基因重排阳性率(18.00%)均明显异于健康人（P<0.05或P<0.01）。结论：白血病患者发病初期即有不同程度的遗传损伤,提示染色体不稳定造成的遗传损伤与白血病发病密切相关。     

Nutritive Evaluation and Effect of Moringa oleifera pod on Clastogenic Potential in the Mouse

Moringa oleifera Lam (horseradish tree; tender pod or fruits) has been consumed as a vegetable and utilizedas a major ingredient of healthy Thai cuisine. Previous studies have shown that M. oleifera pod extracts act asbifunctional inducers along with displaying antioxidant properties and also inhibiting skin papillomagenesisin mice. This study was aimed to determine the nutritive value, and clastogenic and anticlastogenic potentialsof M. oleifera pod. The nutritive value was determined according to AOAC methods. The clastogenic andanticlastogenic potentials were determined using the in vivo erythrocyte micronucleus assay in the mouse. Eightymale mice were fed semi-purified diets containing 1.5%, 3.0% and 6.0% of ground freeze-dried boiled M. oleiferapod (bMO) for 2 weeks prior to administration of both direct-acting (mitomycin C, MMC) and indirect-acting(7, 12-dimethylbenz(a)anthracene, DMBA), clastogens. Blood samples were collected at 0, 24, 48 and 72 h,dropped on acridine orange-coated slides, and then counted for reticulocytes both with and without micronucleiby fluorescence microscopy. The nutritive value of 100 g bMO consisted of: moisture content, 8.2 g; protein,19.2 g; fat, 3.9 g; carbohydrate (dietary fiber included), 60.5 g; dietary fiber, 37.5 g; ash, 8.1 g and energy, 354kcal. Freeze-dried boiled M. oleifera had no clastogenic activity in the mouse while it possessed anticlastogenicactivity against both direct and indirect-acting clastogens. Freeze-dried boiled M. oleifera pod at 1.5%, 3.0%and 6.0% in the diets decreased the number of micronucleated peripheral reticulocytes (MNRETs) induced byboth MMC and DMBA. However, the effect was statistically significant in the dose dependent manner only inthe MMC-treated group. In conclusion, the present study demonstrated that bMO has no clastogenicity andpossesses anticlastogenic potential against clastogens, and particularly a direct-acting clastogen in the mouse.     

实验性苯中毒对骨髓红细胞微核改变的意义

目的 探讨苯的不同给药浓度对骨髓红细胞微核改变的影响,拟建立一种理想的苯中毒模型,为进一步苯的实验研究奠定基础.方法 昆明种小鼠50只,随机分为5组:1个对照组,4个实验组,每组10只.对照组单纯皮下注射生理盐水,实验组在每周一、三、五皮下注射苯制剂,并按所给苯剂量分为B1组(0.5 ml/kg体重)、B2组(1.0 ml/kg体重)、B3组(1.5 ml/kg体重)、B4组(2.0 ml/kg体重),各实验组分别于给苯前及给苯1、2.3、4周后称重动物,检测外周血及骨髓中红细胞微核的变化等指标.结果 ①与对照组相比,实验组小鼠白细胞、血红蛋白、血小板三项指标B1、B2组只部分指标改变,B3、B4组在给苯4周后全部指标与对照组相比差异有统计学意义(P均<0.05).②实验组小鼠外周血及骨髓红细胞微核率随着苯注射时间的延长呈现一定的上升趋势,在第3周出现高峰后,第4周下降.③第4周各实验组与对照组比较,小鼠骨髓嗜多染红细胞微核率明显上升,且差异有统计学意义(P均<0.05).结论 苯中毒可以导致小鼠外周血成熟红细胞和骨髓嗜多染红细胞微核率的增高,以此可作为检测骨髓红细胞受抑状态.     

放射工作人员细胞遗传学损伤与受照剂量的关系分析

目的:探讨放射工作人员职业低剂量辐射对细胞遗传学损伤的影响。方法:选择本院从事放射诊断、介入治疗及放射相关科研的人员共120例作为观察组,在本院从不接受放射线的科室选择30例工作人员为对照组,采用微量全血培养法检测2组染色体和微核的变化。结果:观察组个人累积受照剂量最高为89.21mSv,最低0.36mSv,平均35.87mSv;其染色体总畸变率和染色体细胞畸变率均高于对照组(P0.01),且随着累积受照剂量的增加呈现逐渐升高的趋势;微核细胞率和微核阳性检出率观察组亦高于对照组(P0.01)。结论:细胞遗传学损伤与是否受照及受照剂量存在明显的剂量反应关系,应加强对放射工作人员的职业防护。     

胆碱与叶酸组合对人成淋巴细胞株DNA损伤效应

目的探讨叶酸充足时胆碱缺乏对人成淋巴细胞株的遗传损伤效应。方法在甲硫氨酸(Met)浓度为50μmol/L条件下,设置0～21.5μmol/L的胆碱与30、60、120、240nmol/L的叶酸(folic acid,FA)组成不同浓度组合,培养人成淋巴细胞株9d后,利用胞质阻断微核细胞组分析(CBMNCyt),评价上述组分缺乏诱发的微核化双核细胞(MNedBNC)、核质桥(NPB)及核芽(NBUD)千分率。结果各叶酸浓度下,低浓度胆碱组(0、3、6μmol/L)与高浓度胆碱组(12、18、21.5μmol/L)之间的MNedBNC及NBUD千分率差异有统计学意义(P0.001);低叶酸情况下(30、60nmol/L),12μmol/L胆碱以上的NPB千分率显著降低(P0.001),而高叶酸情况下(120、240nmol/L)各胆碱浓度之间的NPB率无显著差异。胆碱和叶酸对MNedBNC、NPB及NBUD变异的贡献率均达到了极显著(P0.001)。结论胆碱不足对人成淋巴细胞株造成遗传损伤,该细胞株基因组的稳定需要叶酸和胆碱浓度分别维持在120nmol/L和12μmol/L以上。     

白眉蝮蛇蛇毒精氨酸酯酶的致突变研究

目的与方法：采用Ames试验、小鼠骨髓嗜多染红细胞微核试验及小鼠精子畸形试验研究白眉蝮蛇(Agkistrodon halys ussuriensis )蛇毒中精氨酸酯酶有无致突变毒性,为临床应用提供安全性依据。结果与结论：3项试验均为阴性,精氨酸酯酶对所试菌株、小鼠体细胞及雄性生殖细胞均无诱变性。从致突变角度考虑,精氨酸酯酶在高于临床治疗剂量约100倍的条件下仍然安全。     

益母草对小鼠遗传物质损伤的影响

目的:观察中草药益母草对醋酸铅引起的小鼠遗传物质损伤的影响。方法：采用小鼠骨髓微核试验和小鼠精子畸形试验。结果：益母草本身不能诱发小鼠骨髓微核和小鼠精子畸形,但在与醋酸铅一同给药时,可使醋酸铅所诱发的小鼠骨髓微核和小鼠精子畸形频率明显降低。结论：益母草对小鼠遗传物质具有保护作用,即抗诱变作用。