重组人骨形成蛋白-2在造血损伤治疗中作用机制的探讨

目的 探讨重组人骨形成蛋白-2(rhBMP-2)在治疗造血损伤中的作用机制,构建探针并通过原位杂交技术观察rhBMP-2治疗小鼠急性造血损伤的作用。方法 将22只BALB/c雌性小鼠随机分为照射组和骨形成蛋白治疗组。把正常雄性小鼠的骨髓细胞移植给接受8.5 Gy ⁶⁰Coγ 射线照射的22只BALB/c雌性小鼠。14 d后,剩余存活的雌性小鼠左股骨再接受9 Gy的电子线照射。骨形成蛋白治疗组小鼠每天每只腹腔注射重组人骨形成蛋白-2 20 mg/kg,连续治疗6 d,照射对照组每天每只腹腔注射等量生理盐水。14 d后,处死小鼠并取股骨制成石蜡切片。用原位杂交技术检测雌性小鼠股骨中雄性供体小鼠的骨髓细胞。结果 原位杂交结果显示,照射组小鼠左股骨骨髓中的供体来源细胞数量明显比骨形成蛋白治疗组小鼠左股骨骨髓中多(T=155.0,P<0.05)。而照射组小鼠左股骨骨髓中供体来源细胞数量与2组小鼠右股骨骨髓中相比则无明显差异(T=92.0、78.5,P>0.05)。骨形成蛋白组小鼠左股骨骨髓中的供体来源细胞数量明显比两组小鼠右股骨骨髓中少(T=155.0、55.0,P<0.05)。结论 rhBMP-2促进了自身受损伤的骨髓细胞修复,故在骨形成蛋白组小鼠的左股骨骨髓中几乎检测不到供体雄性小鼠SRY基因的存在。推测rhBMP-2促进了自身骨髓间充质干细胞增殖或分化,并改善造血微环境,加快造血修复、重建的过程。     

电磁脉冲暴露对雄性成年小鼠生殖的影响

目的 探讨电磁脉冲（EMP）对雄性小鼠生殖的影响。方法 48只健康成年雄性BALB/c小鼠（8周龄）,用随机数表法分为假暴露组和暴露组,每组24只。动物进行EMP全身暴露或假暴露,EMP场强720 kV/m,脉宽40 ns,重复频率1 Hz,脉冲次数100次。EMP暴露后不同时间（1、7、14和35 d）腹腔麻醉小鼠,剥离双侧附睾尾,游离精子,检测精子质量（包括精子数量、畸形率和存活率）;剥离双侧睾丸,HE染色法观察其组织形态,测量生精小管直径;ELISA和Western blot检测睾丸组织内干细胞因子（SCF）和胶质源性神经营养因子（GDNF）的水平。结果 EMP暴露后1、7、14和35 d,与假暴露组相比,暴露组小鼠的精子质量和睾丸形态结构无明显改变（P>0.05）;小鼠生精小管直径,暴露组分别为（196.85±16.65）、（196.79±14.33）、（196.35±22.71）和（198.60±25.88）μm;假暴露组分别为（204.31±27.13）、（197.07±18.11）、（194.37±21.45）和（200.59±19.36）μm,两组比较差异无统计学意义（P>0.05）。SCF和GDNF水平在EMP暴露后不同时间差异无统计学意义（P>0.05）。结论 本实验条件下的EMP暴露对成年雄性小鼠的睾丸结构和生殖功能无明显影响。     

间充质干细胞促进半相合骨髓移植治疗急性放射病小鼠的实验研究

目的 探讨骨髓间充质干细胞(MSCs)促进半相合造血干细胞移植(haploid-SCT)治疗急性放射病小鼠的作用及机制。方法 ⁶⁰Co γ射线照射BALB/C(H-2^d)雌性小鼠8Gy,单独输注半相合CB6F1(H-2 bd) 雄性小鼠骨髓细胞1×10⁹/kg(I组),或联合CB6F1 雌性小鼠MSCs不同数量级1.5×10⁸/kg (a组)、5×10⁷/kg (b组)和2.5×10⁷/kg (c组)治疗,比较放射病小鼠的生存分析。同时,MSCs组小鼠尾静脉输注经cm-DiI膜染剂标记的CB6F1雌性小鼠MSCs和CB6F1雄性小鼠的骨髓细胞,与只输注CB6F1骨髓细胞的对照组比较,观察移植后不同时间供者细胞在受者骨髓的植入率、供者MSCs在受者体内发布、外周血象、T淋巴细胞亚群、胸骨骨髓病理和慢性移植物抗宿主病(GVHD)发生情况。结果 a组小鼠早期死亡率增加;b和c组存活率高于I组(P<0.05),但二组之间差异无统计学意义。移植后30 d,MSCs组受者骨髓的sry基因高于对照组。移植后MSCs主要集中在胸腺、骨髓、肝和小肠中,有形态改变。MSCs组的白细胞、血小板恢复较快。照射后15和30 d,MSCs组小鼠骨髓腔中的巨核细胞明显高于对照组。移植后7、14和30 d,MSCs组CD3高于对照组(P<0.05);移植后14和30 d,MSCs组CD4阳性细胞率和CD4/CD8值高于对照组(P<0.05)。MSC组慢性GVHD症状出现较对照组晚30 d。结论 MSCs通过促进干细胞植入,改善造血微环境,促进造血恢复,加快T淋巴细胞的恢复,延缓GVHD的发生时间和促进放射损伤的组织器官的修复,加强了半相合骨髓移植对急性放射病的治疗作用。     

小剂量辐射对小鼠全基因组DNA甲基化的影响

目的 探讨小剂量辐射(LDR)对小鼠全血基因组DNA甲基化的影响,以及DNMT1、MBD2在外周血单个核细胞(PBMC)及各组织中的表达变化。方法 SPF级BALB/c雄性小鼠30只按随机数字表法均分为3组:对照组、单次0.5 Gy照射组和分次0.5 Gy(0.05 Gy/d×10 d)照射组。照射组均行6 MV X射线全身照射。其中分析早期效应的15只小鼠(5只/组)在末次照射后2 h,每组10只处死,分析延迟效应的另外15只小鼠末次照射后30 d处死。收集PBMC、肾脏、肝脏、脾脏、脑及肺组织。采用整体甲基化定量试剂盒和高效液相色谱法(HPLC)分析全血DNA甲基化水平,RT-PCR法检测小鼠PBMC及各组织DNMT1和MBD2 mRNA的表达。结果 末次照射后2 h,与对照组比较,分次照射组全血DNA甲基化水平降低(两种检测方法,t =10.19和8.93,P<0.05),DNMT1和MBD2 mRNA在小鼠PBMC、肾脏和肝脏中表达均降低(t =5.06、3.01、3.97、12.25、3.50和3.73,P<0.05),MBD2 mRNA表达在脾脏中降低(t =3.03,P<0.05);而单次照射组均无明显改变。末次照射后1个月,单次、分次照射组的全血甲基化水平较对照组差异均无统计学意义,仅分次照射组小鼠PBMC和脑组织MBD2 mRNA水平降低(t =3.52和2.85,P<0.05)。结论 分次LDR可引起全基因组低甲基化,这种效应具有组织特异性,可能与DNMT1、MBD2的表达降低有关。     

电离辐射对小鼠脾脏ICOS/ICOSL及相关信号通路的影响

目的 观察不同剂量X射线照射后小鼠脾细胞可诱导共刺激分子及其配体（ICOS/ICOSL）与核因子NF-κB、细胞因子IL-10表达量的变化。方法 健康ICR小鼠按随机数字表法分为低剂量照射组（0.05、0.075和0.2 Gy）、高剂量照射组（1、2、4和6 Gy）和假照组。假照组于假照后16 h处死,高、低剂量照射组分别于照后0、4、8、16、24、48、72 h处死小鼠,分离小鼠脾脏制成单细胞悬液,提取脾组织总蛋白,采用流式细胞术检测ICOS/ICOSL,Western blot法检测NF-κB蛋白水平,采用ELISA法检测IL-10分泌量的变化。结果 在0.05、0.075 Gy低剂量照射后,ICOS/ICOSL双阳性细胞百分比显著低于假照组（t=4.743、4.120,P<0.01）;在4、6 Gy高剂量照射后 ,则上调其表达（t=-4.950、-7.310,P<0.01）。核因子NF-κB变化趋势与ICOS/ICOSL表达变化相似。IL-10在0.075、0.2 Gy低剂量照射后明显低于假照组（t=5.277、2.854,P<0.05）,但在6 Gy照射后明显高于假照组（t=7.196,P<0.01）。结论 低剂量电离辐射抑制ICOS/ICOSL、NF-κB和IL-10的表达,而高剂量辐射上调ICOS/ICOSL表达,并激活核因子NF-κB,进而导致IL-10分泌量升高。     

香兰素衍生物VND3207对小鼠骨髓细胞遗传损伤的防护效应研究

目的 研究香兰素衍生物4-羟基-3,5-二甲氧基苯甲醛(VND3207)对γ射线整体照射小鼠骨髓细胞遗传损伤的防护作用。方法 BALB/c小鼠按10、50和100 mg/kg不同剂量灌胃给药,1次/d,连续5 d,最后一次给药后2 h, 2 Gy ⁶⁰Co γ射线照射,照射后48 h观察小鼠骨髓嗜多染红细胞微核、染色体畸变和骨髓有丝分裂指数的改变。结果 不同剂量(10、50和100mg/kg)的VND3207均能有效地降低小鼠骨髓嗜多染红细胞微核率(t=2.40～4.26,P<0.05)和染色体畸变率(t=2.36～3.52,P<0.05),同时提高骨髓有丝分裂指数。药物保护效果与给药剂量呈依赖关系,其中100 mg/kg剂量组的微核率和染色体畸变率与单纯照射组相比,分别降低了65%和50%。结论 VND3207对⁶⁰Co γ射线诱发的小鼠骨髓辐射损伤有良好的保护作用。     

氡暴露致小鼠骨髓细胞的DNA损伤

目的 研究氡暴露致小鼠骨髓细胞的DNA损伤。方法 采用雄性BALB/C小鼠24只,随机分为4组,每组6只,除对照组外,处理组小鼠整体暴露于多功能生态氡室,吸入氡及其子体的累积剂量分别为27(低剂量组)、52(中剂量组)和105(高剂量组)工作水平月(WLM)。采用单细胞凝胶电泳(SCGE)、微核(MN)实验、激光共聚焦显微镜(LSCM)检测小鼠骨髓细胞的DNA链断裂、微核细胞率及凋亡率,观察氡暴露致小鼠骨髓细胞的DNA损伤。结果 高剂量氡暴露可造成小鼠骨髓细胞DNA断裂,尾长和尾DNA百分含量与对照组相比,差异有统计学意义(F=201.9,40.78,P<0.05);微核率和凋亡率增加差异有统计学意义(F=16.28,41.62,P<0.05)。而中、低剂量组则无明显改变。结论 高剂量氡暴露引起DNA损伤,从而对小鼠骨髓细胞产生毒效应。     

电磁脉冲诱导大鼠心肌闰盘间隙开放及其机制

目的 探讨电磁脉冲(EMP)诱导心肌闰盘(ID)的改变及其作用机制。方法 用EMP模拟发生器,场强为50~400 kV/m,脉冲次数200次,雌性SD大鼠30只,随机分为5组,每组6只。照后12 h时采用硝酸镧示踪法和透射电子显微镜观察心肌ID结构的改变,用基因芯片检测受照心肌差异基因表达谱。结果 照后12 h,辐照组的ID间隙随着EMP场强的增加而逐渐增宽,ID间隙中沉积的镧颗粒随着EMP场强的增加而逐渐增多。200 kV/m 组与对照组相比差异表达基因有108个,其中表达上调基因有synaptorin、VGF、HSP70等51条,下调基因有NAD、FGF、Tff3等57条。结论 在场强为50~400 kV/m EMP范围内辐照可诱导心肌ID间隙开放,且随场强的增加而增宽,以400 kV/m时最为显著,受照心肌有108个基因差异表达。     

粒细胞集落刺激因子对急性辐射损伤小鼠胸腺细胞亚群及其近期输出功能的影响

目的 观察粒细胞集落刺激因子(G-CSF)对急性辐射损伤小鼠胸腺细胞亚群重建及近期输出功能的影响。方法 雌性BALB/c小鼠50只给于6 Gy ⁶⁰Co 1次性全身照射后随机均分为GCSF组和对照组。GCSF组小鼠给予重组人G-CSF 100 μg·kg^-1·d^-1皮下注射,连续14 d,对照组小鼠给予等体积磷酸盐缓冲液(PBS)皮下注射,连续14 d。照后7、14、21 和28 d颈部脱臼处死小鼠,取出胸腺制成单个核细胞悬液,使用流式细胞仪检测胸腺双阴性细胞发育4阶段(DN1~4)细胞比例的变化,以及CD4 +CD8 +、CD4 +CD8-、CD4-CD8 +细胞亚群的比例。使用荧光定量PCR的方法检测照后30 和60 d 10⁵个胸腺细胞中T细胞受体重排删除环(sjTREC)拷贝数,判断胸腺输出功能。结果 照后7 d,胸腺DN细胞大量增殖,DN1细胞比例下降,DN4细胞比例增高,GCSF组DN1细胞比例在此时间点明显高于对照组(t=9.59,P＜0.05)。照后21 d GCSF组DN3、 DN4细胞比例均分别高于对照组(t=16.37、 7.6, P＜0.05)。照后7 d CD4 +CD8 +细胞比例降至最低,14 d出现反弹,21 d再次下降,以后逐渐恢复,照后28 d GCSF组CD4 +CD8 +细胞比例恢复正常并明显高于对照组 (t=12.22, P<0.05)。G-CSF对胸腺CD4 +CD8-细胞比例影响不大。照后21 d GCSF组CD4-CD8 +细胞比例明显高于对照组(t=3.77, P<0.05)。荧光定量PCR结果提示照后30 d GCSF组胸腺细胞sjTREC拷贝数明显高于对照组(t=5.95,P＜0.01),但照后60 d 两组胸腺细胞sjTREC拷贝数差异无统计学意义。结论 G-CSF可促进急性辐射损伤小鼠胸腺双阴性及双阳性细胞的增殖、分化,提高胸腺输出功能,加快中枢免疫重建。     

自由基清除剂Tempol对小鼠放射性下颌腺损伤防护机制的研究

目的 探讨不同浓度自由基清除剂Tempol（TPL）对C57bl/6小鼠下颌腺放射性损伤的防护作用及作用机制。方法 120只雄性C57bl/6小鼠,随机数字表法分为空白对照组、单纯照射组、25 mg/kg TPL组、200 mg/kg TPL、25 mg/kg TPL +照射和200 mg/kg TPL +照射组,共6个组,每组20只。两个联合治疗组在15 Gy照射前10 min腹腔注射给药。观察给药后30 d小鼠存活率、体重和照射后3和30 d小鼠唾液流率及下颌腺组织细胞凋亡及照射后3 d下颌腺组织总超氧化物歧化酶活性、总谷胱甘肽和丙二醛（MDA）含量及Bcl-2、Bax、Caspase-3蛋白表达水平。结果 照射后3和30 d单纯照射组小鼠唾液腺流率分别为5.67±1.05,5.27±1.34,与TPL 200 mg/kg+照射组比较,明显降低,差异有统计学意义（F=226.4,215.3,P<0.05）,而与TPL25 mg/kg+照射组比较,差异无统计学意义;此外,TPL 200 mg/kg预处理降低照射后细胞的凋亡和组织MDA的含量（F=175.2,P<0.05）,增加总谷胱甘肽（GSH）的含量和总超氧化物歧化酶（SOD）的活性（F=244.5、205.5,P<0.05）,增加Bcl-2蛋白水平,降低Bax和活化Caspase-3蛋白水平。结论 200 mg/kg TPL对C57bl/6小鼠下颌腺组织具有放射保护作用,其机制可能为减轻组织氧化应激和调节线粒体凋亡信号通路,而25 mg/kg TPL没有此保护作用。     

Effect of Electromagnetic Pulses (EMP) on associative learning in mice and a preliminary study of mechanism

Abstract

Purpose: To investigate the effects of electromagnetic pulses (EMP) on associative learning in mice and test a preliminary mechanism for these effects.

Materials and methods: A tapered parallel plate gigahertz transverse electromagnetic (GTEM) cell with a flared rectangular coaxial transmission line was used to expose male BALB/c mice to EMP (peak-intensity 400 kV/m, rise-time 10 ns, pulse-width 350 ns, 0.5 Hz and total 200 pulses). Concurrent sham-exposed mice were used as a control. Associative learning, oxidative stress in the brain, serum chemistry and the protective action of tocopherol monoglucoside (TMG) in mice were measured, respectively.

Results: (1) Twelve hour and 1 day post EMP exposure associative learning was reduced significantly compared with sham control (p < 0.05) but recovered at 2 d post EMP exposure. (2) Compared with the sham control, lipid peroxidation of brain tissue and chemiluminescence (CL) intensity increased significantly (p < 0.05), while the activity of the antioxidant enzymes Superoxide Dismutase [SOD], Glutathione [GSH], Glutathione Peroxidase [GSH-Px], Catalase [CAT]) decreased significantly (p < 0.05) at 3 h, 6 h, 12 h and 1 d post EMP exposure. All these parameters recovered at 2 d post EMP exposure. (3) No significant differences between the sham control group and EMP exposed group were observed in serum cholesterol and triglycerides. (4) Pretreatment of mice with TMG showed protective effects to EMP exposure.

Conclusions: EMP exposure significantly decreased associative learning in mice and TMG acted as an effective protective agent from EMP exposure. This mechanism could involve an increase of oxidative stress in brain by EMP exposure.     

Electromagnetic pulses induce fluctuations in blood pressure in rats

PURPOSE: To investigate the effects of exposure to electromagnetic pulses (EMP) on functional indices of the cardiovascular system in male Sprague-Dawley rats. MATERIALS AND METHODS: A tapered parallel plate Gigahertz Transverse Electromagnetic cell (GTEM cell) with a flared rectangular coaxial transmission line was used to expose the rats to EMP (0.5 pps, total 200 pulses and whole-body averaged specific absorption rate 50 mW/kg at 200 kV/m or 75 mW/kg at 400 kV/m). Concurrent sham-exposed animals were used as controls. Cardiovascular functions, namely, heart rate, and systolic, mean and diastolic blood pressures were measured immediately and up to 4 weeks post-exposure using a non-invasive tail-cuff photoelectric sensor sphygmomanometer. RESULTS: The heart rates in sham- and EMP-exposed rats were not significantly changed. In the exposed rats, increased systolic blood pressure (SBP) occurred at 0 h and decreased SBP occurred at 1 day and 3 days after exposure. Significantly higher diastolic blood pressure (DBP) was found at 0 h and significantly lower DBP was found at 12 h, 1 day, and 1 month after exposure. Significantly higher mean arterial pressure (MAP) was noted at 0 h and significantly lower MAP was noted at 1 day. CONCLUSIONS: Significant alterations in arterial blood pressure were observed in rats exposed to EMP exposure while heart rate was not altered.     

The effects of electromagnetic pulses (EMP) on the bioactivity of insulin and a preliminary study of mechanism

Purpose:?To investigate the effects of electromagnetic pulse (EMP) exposure on the bioactivity of insulin and a preliminary mechanism for these effects.

Materials and methods:?A tapered parallel plate Gigahertz Transverse Electromagnetic (GTEM) cell with a flared rectangular coaxial transmission line was used to expose the insulin solution to EMP. Concurrent sham-exposed insulin solutions were used as a control. The effect of EMP-exposed insulin on fasting blood glucose levels of type I diabetes model mice, the effect of EMP on binding affinity between insulin and its receptor and the effect of EMP on insulin's fluorescence intensity were detected, respectively.

Results:?(i) After EMP exposure, compared with sham-exposed insulin, the bioactivity of insulin in decreasing fasting blood glucose levels in type I diabetes model mice was reduced significantly (p?=?0.023). (ii) Compared with sham-exposed insulin group, the percentage fluorescein isothiocyannate (FITC) labelling of HL-7702 cells was significantly reduced in the EMP-exposed insulin group (22.7–13.8%, respectively). (iii) Compared with sham-exposed insulin, the fluorescence intensity was significantly reduced in EMP-exposed insulin (p?<?0.001).

Conclusions:?EMP exposure significantly decreased the bioactivity of insulin to reduce the blood glucose levels in type I diabetic mice. This could be due to a decreased binding affinity between insulin and its receptor. This mechanism could involve an alteration of insulin's' conformation caused by EMP exposure.     

Prenatal irradiation and spatial memory in mice: investigation of critical period.

Pregnant CD1 mice were exposed on various gestational or postnatal days to 1 Gy of 250 kV X-rays. Ten adult, male offspring from each exposure condition were tested in a radial arm maze. Compared to sham-exposed control mice, acquisition of spatial information was unimpaired in animals exposed on gestational days 13 or 15, or on postnatal day 10, but animals exposed on gestational day 18 or postnatal day 1 showed sustained deficits in acquisition. These results appear consistent with the known time-course for the proliferation and migration of the dentate granule cells of the hippocampus in the mouse, and are discussed in relation to the dependence on hippocampal integrity of the acquisition and use of spatial information. The results suggest that comparable deficits in mental function might be expected in humans similarly exposed to ionizing radiation during periods of proliferation and migration of the dentate granule cells.     

长期食入低剂量贫铀对大鼠的生殖毒性研究

目的 研究长期食入低剂量贫铀对大鼠的生殖毒性。方法给予初断乳大鼠含贫铀饲料，食入贫铀的剂量分别为0、0．4、4和40mg·k^-1·d^-1，4个月后，采用两代-窝法观察整体生殖毒性效应；放射免疫法检测睾酮（T）、黄体生成素（LH）、卵泡刺激素（FSH）等血清性激素水平；比色法测定睾丸中乳酸脱氢酶同工酶（LDH—X）、琥珀酸脱氢酶（SDH）及Na^＋-K^＋’ATPase、ca2’-ATPase等精子生成和代谢有关酶的比活性。结果亲代（F0代）大鼠各项指标未见显著改变。子代（F1代）高剂量组的受孕率、正常分娩存活率、幼仔出生存活率、幼仔哺育存活率均下降，与对照组相比，差异有统计学意义。食入贫铀的F0代大鼠血清性激素含量较正常组增加，但F1代除T升高外，其余性激素均下降。Fn代高剂量组睾丸中LDH含量降低；F1代大鼠中、高剂量组SDH、LDH和Na^＋-K^＋-ATPaSe含量降低。结论长期食入低剂量的贫铀对F0代大鼠未见明显生殖毒性，但F1代大鼠的生殖毒性效应显著增加。     

Cytogenetic Effects of Microwave Irradiation on Male Germ Cells of the Mouse

Summary

Hybrid male mice were exposed to 2·45 GHz microwaves for 30 min/day, 6 days a week for two consecutive weeks at power densities of 1·0, 100 or 400 W m^?2, with sham-exposed controls. Rectal temperatures before and after exposure were measured on days 1, 6 and 12. Measurements made on day 1 were treated with caution because of heterogeneity in rectal temperatures taken before exposure between the groups of mice given different treatments. On days 6 and 12, rectal temperatures rose by approximately 1°C in mice sham exposed, or exposed to 1 W m^?2 or 100 W m^?2. Only in the group of mice exposed to 400 W m^?2 was the mean rise in rectal temperature during exposure (about 3°C) significantly increased above the sham value. In groups killed 2–3 days after treatment (mainly meiotic exposure) frequencies of chromosome aberrations in spermatocytes showed no significant heterogeneity although the highest frequency of 1·5 per cent was at the highest (400 W m^?2 power density. Another group killed 30 days after 100 W m^?2 exposures (spermatogonial sampling) showed no significant increase over controls in chromosome aberration frequency. There was a small but significant increase in sperm count with increasing power density in mice killed 12–13 days after exposure, but a non-significant one in those exposed as spermatogonia (killed 41 days later). Thus effects were markedly less severe than those reported previously by Manikowska-Czerska et al. (1985) with a very similar radiation regime and were probably caused by the temperature enhancement.     

Influence of electromagnetic fields on reproductive system of male rats

Abstract

Purpose: Reports of declining male fertility have renewed interest in the role of environmental and occupational exposures in the etiology of human infertility. The aim of the present work was to investigate the effect of 10 GHz exposure on the male Wistar rat's reproductive system and to find out the possible causative factors.

Materials and methods: The study was divided into sham-exposed and exposed groups. Seventy day-old rats were exposed to 10 GHz microwave radiation for 2 h per day for 45 days at power density 0.21 mW/cm² and specific absorption rate (SAR) of 0.014 W/kg. After the end of the experiment, blood samples were collected for the estimation of in vivo chromosomal aberration damage and micronucleus test. Spermatozoa were taken out for estimation of Caspase-3, comet assay, testosterone and electron microscopy and compared with sham-exposed.

Results: The study of scanning electron microscopic revealed shrinkage of the lumen of the seminiferous tubules. Apoptotic bodies were found in exposed group. A flow cytometry examination showed formation of micronuclei body in lymphocytes of exposed group. Comet assay confirmed DNA (deoxyribonucleic acid) strand break. Testosterone level was found significantly decreased with the shrinkage of testicular size.

Conclusions: 10 GHz field has an injurious effect on fertility potential of male-exposed animals.     

X射线胸部照射对小鼠精子发生的影响

目的:探讨X射线胸部照射对雄性成年小鼠精子发生的影响。方法:将24只健康雄性成年C57BL/6小鼠(6~8周龄)按照随机数表法分为X射线照射组(Radiation)和假照射组(Sham),每组12只。胸部照射面积为1.5 cm × 2 cm,剂量率3.04 Gy/min,8 Gy/d,连续照射3 d,总剂量24 Gy,...     

膝关节置换术后X射线摄影中不同曝光模式对影像质量和辐射剂量的影响

目的 探讨膝关节置换术（TKA）术后最佳摄影条件及临床应用的可行性。方法 根据不同的曝光方式,分为自动曝光模式组（AEC）、手动曝光模式组（FIXED）,以固定kV、依次改变相应mAs的方式,对模体进行曝光,记录各曝光条件下入射剂量（ESD）、剂量曝光指数（DEI）、主观图像质量评价,经统计学分析后得出最优化试验组参数与回顾组进行辐射剂量及主观评价比较。结果 AEC组ESD与kV呈负相关（r=-0.973,P < 0.05）,在相同mA条件下,DEI随kV增加呈先减后增的弧线型变化,主观图像质量评价均值为（1.96±0.56）,DEI与主观图像评分呈负相关（r=-0.840,P < 0.05）。FIXED组ESD随mAs的增加而成线性增加,呈正相关（r=0.845,P < 0.05）,DEI与kV、mAs成正相关（r=0.628、0.674,P < 0.05）。主观图像质量评价均值为（4.33±0.79）,与DEI无相关性。选择最优化实验组与回顾组相比,主观图像质量评价分值增加,辐射剂量降低明显。结论 对于膝关节置换假体植入受检患者,采用手动曝光模式,80 kV/1.25~1 mAs、75 kV/2~1 mAs、70 kV/2.5~1.25 mAs、65 kV/3.2~1.6 mAs和60 kV/3.2~2 mAs为最优化区间。