The rupture of mine-tailings dams can severely contaminate rivers, because released tailings can interact with water for years keeping contaminant concentrations high. The general purpose of this study was to examine the rupture of B1 tailings dam in Ferro-Carvão stream (municipality of Brumadinho, state of Minas Gerais, Brazil), which occurred in 25 January 2019 and contaminated the main water course (Paraopeba River) with 2.8 Mm3 of metal-rich tailings. The specific purpose was to assess the percentage of non-conforming concentrations following the event, considering the Normative Deliberation COPAM/CERH-MG no. 1. The results showed non-conforming aluminum, iron, manganese, lead, phosphorus and turbidity concentrations, clearly above pre-rupture averages, especially in the rainy period. The catastrophe triggered the suspension of Paraopeba River as drinking water source to the Metropolitan Region of Belo Horizonte (BHMR; 6 million people). Since then, the supply to the BHMR became an everyday challenge to water management authorities, because the Paraopeba source represented a 30% share. Mitigation measures are therefore urgently needed. As complementary objective to this study, we aimed to verify the possibility to restore drinking water supply through conventional treatment. The treatability of Paraopeba River water was assessed by the Raw Water Quality Index considering the rainy and dry periods in separate. The results suggested the possibility to lift up the suspension in the dry period, improving the regional water security. Considering the huge dataset on which this study is standing, our results are generalizable to similar events with sparser information.

In this study, we firstly investigated the effects of electromagnetic pulses (EMP) on the permeability of blood-brain barrier (BBB) by exposing the rats to EMP at 200 kV/m for 400 pulses. The permeability of BBB was examined by using Evans Blue (EB) and lanthanum nitrate as vascular tracers. It was found that EMP reversely increased the permeability of BBB. Next, we explored the feasibility of EMP facilitating the chemotherapeutics to penetrate BBB and the treatment efficacy in a glioma-bearing rat model by detecting the drug (CCNU) concentration in tumor tissue, tumor size and tumor apoptosis. It was found that EMP enhanced the delivery of CCNU to tumor tissue, facilitated CCNU-induced tumor apoptosis, and obviously inhibited tumor growth. The data indicated that EMP-induced BBB opening could enhance the drug delivery and increase the treatment efficacy of brain tumor.

Radiofrequency (RF) electromagnetic radiation (EMR) is non-ionizing radiation with frequencies in the range from about 10 MHz to 300 GHz that directly influences on human health [1], [2] . The RF-EMR field produced by cellular phones is mainly at the frequencies of 850 to 2100 MHz. The studies of RF-EMR on testis function have mostly been performed in vivo level to evaluate gross effects on fertility or testis function, but have not given insight into the effects of this radiation in vitro level. Leydig cells are the interstitial testis cells with a crucial role for regulating spermatogenesis and male reproductive function, which could secrete 95% of the testosterone for the male.

Effects of pulsed electromagnetic field (PEMF) on hematology and hematopoiesis might vary with different PEMF parameters. The purpose of this study was to evaluate the possible effects of PEMF exposure at different pulses on hematologic and hematopoietic parameters in mice. Groups of male BALB/c mice were whole body exposed or were sham exposed (control) to PEMF at 100, 1000, and 10000 pulses. After PEMF exposure, blood samples and bone marrow cells of mice were collected for hematologic examinations, bone marrow nucleated cell counting, colony-forming units of granulocyte-macrophage (CFU-GM) colony assay, and serum granulocyte-macrophage colony-stimulating factor (GM-CSF) assay. Compared with the control group, white blood cells (WBC) and lymphocytes (LYM) in the 100 and 1000 pulses exposed groups were significantly increased but not changed in the 10000 pulses exposed group. Red blood cells (RBC), hemoglobin (HGB), and platelets (PLT) were not changed in all exposed groups. There was no significant difference in mouse bone marrow nucleated cell number between the control group and each exposed group 7 days after PEMF exposure. The CFU-GM clone number of bone marrow cells and serum GM-CSF level were significantly increased in the 100 and 1000 pulses exposed group but not changed in the 10000 pulses exposed group. Our results indicated that the PEMF exposure at fewer pulses may induce statistically significant alterations in some hematologic and hematopoietic parameters of mice but no changes can be found in the more pulses PEMF-exposed groups.

More studies that are focused on the bioeffects of radio-frequency (RF) electromagnetic radiation that is generated from the communication devices, but there were few reports with confirmed results about the bioeffects of RF radiation on reproductive cells. To explore the effects of 1950 MHz RF electromagnetic radiation (EMR) on mouse Leydig (TM3) cells. TM3 cells were irradiated or sham-irradiated continuously for 24 h by the specific absorption rate (SAR) 3 W/kg radiation. At 0, 1, 2, 3, 4, and 5 days after irradiation, cell proliferation was detected by cell counting kit-8 (CCK-8) method, cell cycle distribution, percentage of apoptosis, and cellular reactive oxygen species (ROS) were examined by flow cytometry, Testosterone level was measured using enzyme-linked immunosorbent assay (ELISA) assay, messenger ribonucleic acid (mRNA) expression level of steroidogenic acute regulatory protein (StAR) and P450scc in TM3 cells was detected by real-time polymerase chain reaction (PCR). After being irradiated for 24 h, cell proliferation obviously decreased and cell cycle distribution, secretion capacity of Testosterone, and P450scc mRNA level were reduced. While cell apoptosis, ROS, and StAR mRNA level did not change significantly. The current results indicated that 24 h of exposure at 1950 MHz 3 W/kg radiation could cause some adverse effects on TM3 cells proliferation and Testosterone secretion, further studies about the biological effects in the reproductive system that are induced by RF radiation are also needed.

Chemotherapy on gliomas is not satisfactorily efficient because the presence of blood-brain barriers (BBB) leads to inadequate exposure of tumor cells to administered drugs. In order to facilitate chemotherapeutics to penetrate BBB and increase the treatment efficacy of gliomas, electromagnetic pulse (EMP) was applied and the 1-(2-Chlorethyl)-cyclohexyl-nitrosourea (CCNU) lomustine concentration in tumor tissue, tumor size, tumor apoptosis, and side effects were measured in glioma-bearing rat model. The results showed that EMP exposure could enhance the delivery of CCNU to tumor tissue, facilitate tumor apoptosis, and inhibit tumor growth without obvious side effects. The data indicated that EMP-induced BBB disruption could enhance delivery of CCNU to glioblastoma multiforme and increase treatment efficacy in glioma-bearing rats. Bioelectromagnetics. 39:60-67, 2018. © 2017 Wiley Periodicals, Inc.

In recent years, intense interest has been drawn to the effects of radio-frequency electromagnetic field (RF-EMF) on reproduction.To explore the effects of RF-EMF on sperm maturation in epididymis microenvironment, 24 male Sprague Dawley (SD) rats were randomly divided into three exposed groups (SAR 1, 2 and 4 W/kg) and one sham group.The rats in exposed group were exposed to 1.84 GHz RF-EMF for 5 days (1 h/day).After that, the rats were anaesthetized immediately and epididymis were taken out.Half of them were fixed in 4% formalin and the others were placed in tissue homogenate.The morphology of sperm and microstructure of epididymis were observed under microscope after hematoxylin-eosin (HE) staining.Expression of Bin1b protein was detected by immunohistochemistry; the level of glutathione (GSH) and enzymes including superoxide dismutase (SOD), acid phosphatase (ACP), alkaline phosphatase (ALP) and disaccharidase were determined by commercial kits.It was found that, compared with sham group, the sperm morphology and microstructure of epididymis did not change obviously; similarly, there was no significant change in Bin1b protein expression and the levels of GSH, SOD, ACP and ALP in exposure group.These results suggest that 1.84 GHz RF-EMF under this experimental condition could not affect the sperm maturation in epididymis microenvironment of SD rats.

Excessive exposure to infrasound, a kind of low-frequency but high-intensity sound noise generated by heavy transportations and machineries, can cause vibroacoustic disease which is a progressive and systemic disease, and finally results in the dysfunction of central nervous system. Our previous studies have demonstrated that glial cell-mediated inflammation may contribute to infrasound-induced neuronal impairment, but the underlying mechanisms are not fully understood. Here, we show that cannabinoid (CB) receptors may be involved in infrasound-induced neuronal injury. After exposure to infrasound at 16 Hz and 130 dB for 1-14 days, the expression of CB receptors in rat hippocampi was gradually but significantly decreased. Their expression levels reached the minimum after 7- to 14-day exposure during which the maximum number of apoptotic cells was observed in the CA1. 2-Arachidonoylglycerol (2-AG), an endogenous agonist for CB receptors, reduced the number of infrasound-triggered apoptotic cells, which, however, could be further increased by CB receptor antagonist AM251. In animal behavior performance test, 2-AG ameliorated the infrasound-impaired learning and memory abilities of rats, whereas AM251 aggravated the infrasound-impaired learning and memory abilities of rats. Furthermore, the levels of proinflammatory cytokines tumor necrosis factor alpha and interleukin-1β in the CA1 were upregulated after infrasound exposure, which were attenuated by 2-AG but further increased by AM251. Thus, our results provide the first evidence that CB receptors may be involved in infrasound-induced neuronal impairment possibly by affecting the release of proinflammatory cytokines.

采用sXc(System for sXposure of cells)辐照系统、GSM talk信号、频率1950 MHz、SAR值为3 W/kg的射频辐射,辐照小鼠睾丸间质细胞系TM3细胞,连续照射24 h,同时设假辐照组.辐照后,将部分辐照组和假辐照组细胞接种于9块96孔板内,采用CCK8试剂盒测定照射后1-9d细胞增殖能力,绘制生长曲线.另一部分辐照组与假辐照组细胞接种于不同的10 cm培养皿中,分别于照射后1、2、3、4和5d用流式细胞仪检测细胞周期和细胞凋亡的变化.结果显示,照射后2-9 d辐照组细胞增殖能力低于假辐照组细胞(p＜0.05);照射后1-5 d,辐照组细胞周期S期比假辐照组延长(p＜0.05),且于照射后3-5 d辐照组细胞周期G1期比假辐照组缩短(p＜0.05);而照射后1-5 d辐照组细胞凋亡与假辐照组无差异.频率1950 MHz的GSM talk信号射频辐射照射小鼠睾丸间质细胞24 h后,可以通过改变细胞周期,进而抑制细胞增殖,影响TM3细胞生物学作用的发挥,具体的作用机制尚有待于进一步研究.

防原医学是为五年制临床医学专业开设的一门必修的军事医学课程,理解和掌握防原医学知识,是成为具有全面技能的军事医学人才的基础.为了通过本门课程的学习,更好地培养高素质的新型军事医学人才,本文结合第四军医大学五年制临床医学专业学员的培养目标和实际情况,对课程标准的内容制定和实施进行思考,探索课程标准下的防原医学教学模式与方法,旨在进一步提升教学效果,造就新时期军事变革条件下的优秀人民军医.

Power-line frequency electromagnetic field (PF-EMF) was reported as a human carcinogen by some epidemiological research, but the conclusion is lack of robust experiment evidence. To identify the effects of long-term PF-EMF exposure on cell behavior, Balb/c 3T3 cells in exponential growth phase were exposed or sham-exposed to 50 Hertz (Hz) PF-EMF at 2.3 mT for 2 hours (h) one day, 5 days every week. After 11 weeks exposure, cells were collected instantly. Cell morphology was observed under invert microscope and Giemsa staining, cell viability was detected by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay, cell cycle and apoptosis was examined by flow cytometry, the protein level of Proliferating Cell Nuclear Antigen (PCNA) and CyclinD1 was detected by western blot, cell transformation was examined by soft agar clone assay and plate clone forming test, and cell migration ability was observed by scratch adhesion test. It was found that after PF-EMF exposure, cell morphology, apoptosis, cell migration ability and cell transformation didn’t change. However, compared with sham group, cell viability obviously decreased and cell cycle distribution also changed after 11 weeks PF-EMF exposure. Meanwhile, the protein level of PCNA and CyclinD1 significantly decreased after PF-EMF exposure. These data suggested that although long-term 50Hz PF-EMF exposure under this experimental condition had no effects on apoptosis, cell migration ability and cell transformation, it could affect cell proliferation and cell cycle by down-regulation the expression of PCNA and CyclinD1 protein.

Electromagnetic fields are considered to potentially affect embryonic development, but the mechanism is still unknown. In this study, human embryonic stem cell (hESC) line HUES-17 was applied to explore the mechanism of exposure on embryonic development to pulsed electromagnetic field (PEMF) for 400 pulses at different electric field intensities and the differentiation of HUES-17 cells was observed after PEMF exposure. The expression of alkaline phosphatase (AP), stage-specific embryonic antigen-3 (SSEA-3), SSEA-4 and the mRNA level and protein level of Oct4, Sox2 and Nanog in HUES-17 cells remained unchanged after PEMF exposure at the electric field intensities of 50, 100, 200 or 400 kV/m. Four hundred pulses PEMF exposure at the electric field intensities of 50, 100, 200 or 400 kV/m did not affect the differentiation of HUES-17 cells. The reason why electromagnetic fields affect embryonic development may be due to other mechanisms rather than affecting the differentiation of embryonic stem cells.

Objective: Pulsed electromagnetic fields (PEMFs) were considered to be a factor which may affect osteogenesis of osteoblasts, but the effects were diverse with different PEMF parameters. The aim of the current study is to explore the effects of exposure to PEMFs at different pulse number on osteogenesis of osteoblasts.Design: The mouse osteoblast-like MC3T3-E1 cells were exposed to 0, 400 or 2800 pulses 400 kV/m PEMF and the proliferation, differentiation and mineralization of cells were observed after PEMF exposure by the methods of MTT, biochemical measurement, realtime PCR and Alizarin Red assay.Results: Compared with 0 pulses groups, the growth curve, alkaline phosphatase (ALP) activity, mRNA level of osteocalcin (OCN) and mineralized nodule formation of MC3T3-E1 cells did not change after 400 pulses PEMF exposure, but decreased after 2800 pulses PEMF exposure. It suggested that under our experimental conditions, only 2800 pulses 400 kV/m PEMF exposure can suppress the proliferation, differentiation and mineralization of MC3T3-E1 cells, but 400 pulses 400 kV/m PEMF exposure cannot.Conclusions: Pulse number is another involved parameter which may influence the effects of PEMF on osteogenesis of osteoblasts. (C) 2014 Elsevier Ltd. All rights reserved.

Electromagnetic pulse (EMP) was a potentially harmful factor to the human body, and a biological dosimetry to evaluate effects of EMP is necessary. Little is known about effects of EMP on concentration of macro and trace elements in serum so far. In this study, Sprague-Dawley rats were randomly divided into 50-kV/m EMP-exposed group (n = 10), 100-kV/m EMP-exposed group (n = 10), 200-kV/m EMP-exposed group (n = 40), and the sham-exposed group (n = 20). The macro and trace element concentrations in serum were examined at 6, 12, 24, and 48 h after EMP exposure at different electric field intensities. Compared with the sham-exposed groups, the concentration of sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), zinc (Zn), copper (Cu), iron (Fe), selenium (Se), and manganese (Mn) in rat serum was not changed significantly within 48 h after 200 pulses of EMP exposure at electric field intensity of 50, 100, and 200 kV/m although the K level was decreased and the Ca level was increased with the electric field intensity of EMP increasing. In addition, there was a tendency that the Zn level was decreased with the time going on within 48 h after EMP exposure. Under our experimental conditions, EMP exposure cannot affect the concentration of macro and trace elements in rat serum. There was no time-effect or dose-effect relationship between EMP exposure and serum element levels. The macro and trace elements in serum are not suitable endpoints of biological dosimetry of EMP.

患者女性,24岁,因左上肢麻木4年,头痛3个月入院就诊,头颅MRI显示:右顶叶增强均匀占位性病变,伴囊性变,囊腔及囊壁无增强(图1).术中见:右顶叶1.5 cm×1.5 cm×1.5 cm大小灰黄、质韧、边界欠清的占位性病变,瘤外可见-4 cm ×5 cm ×6 cm大小囊腔. 病理检查 眼观:标本为灰白色碎组织,大小1.5 cm×1.5 cm×1.5 cm,质中.镜检:肿瘤组织由以纤维母细胞为主的结缔组织及神经上皮混杂而成.纤维母细胞呈束状、编织状排列(图2),有些肿瘤细胞较肥胖.

We previously reported the synthesis of three DOX conjugates that represented different targeting vehicles and showed them to have antitumor activity both in vitro and in vivo. However, the relationships between the pharmacokinetics of these DOX conjugates and their chemical structures were not characterized. In the current study, free DOX derived from each of the conjugates was found at low levels in the rat circulatory system, with conjugated DOX being the major form. The two polyethylene glycol (PEG) conjugates slowly released DOX, and t1/2β for total DOX from DOX-LNA, PEG-ami-DOX, and PEG-hyd-DOX was 5.79, 10.22, and 15.18 h, respectively. All three conjugates also deposited less DOX into normal organs than did an equivalent dose of free DOX, and the Cmax value of free DOX released by DOX- LNA, PEG-ami-DOX, and PEG-hyd-DOX was 32.5, 9.5, and 4.7 μg/g, respectively. Among the conjugates, the compound with an acid-labile bond between PEG and DOX exhibited the lowest free DOX deposition in healthy tissues, which should decrease the systemic toxicity of free DOX while allowing for tumor targeting by PEG.

目的 探讨乳腺尤因肉瘤/原始神经外胚层肿瘤(primitive neuroectodermal tumors,PNET)的病理诊断及鉴别诊断.方法 对1例乳腺尤因肉瘤/PNET进行免疫组化染色,并复习相关文献.结果镜下观察瘤组织由形态一致的小圆细胞所组成,呈实性片状或乳头状排列,局部可见菊形团样结构.免疫组化显示瘤细胞表达CD99、ER、CD56、GFAP、FLI-1、Calponin等.结论乳腺尤因肉瘤/PNET是少见的小圆细胞恶性肿瘤,CD99、FLI-1及神经内分泌标记物阳性对确诊有重要意义,ER可能在乳腺尤因肉瘤/PNET诊断中有一定的意义.

BACKGROUND:NDRG2, a member of N-Myc downstream regulated gene family, plays some roles in cellular stress, cell differentiation and tumor suppression. We have found that NDRG2 expression in cervical cancer Hela cells increases significantly upon stimulation with cisplatin, the most popular chemotherapeutic agent currently used for the treatment of advanced cervical cancer. This interesting phenomenon drove us to evaluate the role of NDRG2 in chemosensitivity of Hela cells.METHODS:In the present study, RNA interference was employed to down-regulate NDRG2 expression in Hela cells. RT-PCR and Western blot were used to detect expression of NDRG2, Bcl-2 and Bax in cancer cells. Real-time PCR was applied to detect miR-15b and miR-16 expression levels. Drug sensitivity was determined with MTT assay. Cell cloning efficiency was evaluated by Colony-forming assay. Apoptotic cells were detected with annexin V staining and flow cytometry.RESULTS:In vitro drug sensitivity assay revealed that suppression of NDRG2 could sensitize Hela cells to cisplatin. Down-regulation of NDRG2 didn't influence the colony-forming ability but promoted cisplatin-induced apoptosis of Hela cells. Inhibition of NDRG2 in Hela cells was accompanied by decreased Bcl-2 protein level. However, Bcl-2 mRNA level was not changed in Hela cells with down-regulation of NDRG2. Further study indicated that miR-15b and miR-16, two microRNAs targetting Bcl-2, were significantly up-regulated in NDRG2-suppressed Hela cells.CONCLUSIONS:These data suggested that down-regulation of NDRG2 could enhance sensitivity of Hela cells to cisplatin through inhibiting Bcl-2 protein expression, which might be mediated by up-regulating miR-15b and miR-16.

Background Polyphenols, a group of complex naturally occurring compounds, are widely distributed throughout the plant kingdom and are therefore readily consumed by humans. The relationship between their chemical structure and intestinal absorption, transport, and first-pass metabolism remains unresolved, however. Methods Here, we investigated the intestinal absorption and first-pass metabolism of four polyphenol compounds, apigenin, resveratrol, emodin and chrysophanol, using the in vitro Caco-2 cell monolayer model system and in situ intestinal perfusion and in vivo pharmacokinetic studies in rats, so as to better understand the relationship between the chemical structure and biological fate of the dietary polyphenols. Conclusion After oral administration, emodin and chrysophanol exhibited different absorptive and metabolic behaviours compared to apigenin and resveratrol. The differences in their chemical structures presumably resulted in differing affinities for drug-metabolizing enzymes, such as glucuronidase and sulphatase, and transporters, such as MRP2, SGLT1, and P-glycoprotein, which are found in intestinal epithelial cells.

The aim of this study was to investigate the protective effects of three glycosides (rhodioside, ciwujianoside-B and astragaloside IV) on the hematopoietic system in the mice exposed to gamma-rays, and to examine the possible mechanisms involved. Mice were pretreated with the glycosides (40 mg/kg, i.g.) daily for 7 days prior to radiation. The survival of mice pretreated with three glycosides after total body irradiation (6.0 Gy) was examined. Peripheral blood leucocytes and endogenous spleen colony counts, colony-forming unit-granulocyte macrophage assay, analysis of DNA content and apoptosis rate determination were performed to evaluate the effects of the three glycosides on hematogenesis. The fragmentation of double-stranded DNA in lymphocytes was detected by the comet assay. The changes in cell cycle were analysed by flow cytometry. Furthermore, the expression levels of Bcl-2, Bax and nuclear factor-kappa B (NF-kappa B) were measured by western blot and the electrophoretic mobility shift assay. The results showed that pretreatment with all of the glycosides improved survival time and increased the number of leucocytes, spleen colonies and granulocyte-macrophage colonies in mice exposed to 6.0 Gy gamma-radiation. Rhodioside showed more protective efficacy than both ciwujianoside-B and astragaloside IV. All three glycosides significantly increased the proliferation abilities of bone marrow cells, and decreased the ratio of cells in G(0)/G(1) phase. Further analysis showed that these three glycosides were able to decrease DNA damage and the increment in the Bax/Bcl-2 ratio induced by radiation. In summary, the three glycosides showed radioprotective effects on the hematopoietic system in mice, which was associated with changes in the cell cycle, a reduction in DNA damage, and down-regulation of the ratio of Bax/Bcl-2 in bone marrow cells exposed to radiation. Copyright (C) 2010 John Wiley & Sons, Ltd.