Toxicity of Graphene Quantum Dots in Zebrafish Embryo

Objective To evaluate the bio-safety of graphene quantum dots （GQDs）, we studied its effects on the embryonic development of zebrafish. Methods In vivo, biodistribution and the developmental toxicity of GQDs were investigated in embryonic zebrafish at exposure concentrations ranging from 12.5-200μg/mL for 4-96 h post-fertilization （hpf）. The mortality, hatch rate, malformation, heart rate, GQDs uptake, spontaneous movement, and larval behavior were examined. Results The fluorescence of GQDs was mainly localized in the intestines and heart. As the exposure concentration increased, the hatch and heart rate decreased, accompanied by an increase in mortality. Exposure to a high level of GQDs （200μg/mL） resulted in various embryonic malformations including pericardial edema, vitelline cyst, bent spine, and bent tail. The spontaneous movement significantly decreased after exposure to GQDs at concentrations of 50, 100, and 200μg/mL. The larval behavior testing （visible light test） showed that the total swimming distance and speed decreased dose-dependently. Embryos exposed to 12.5 μg/mL showed hyperactivity while exposure to higher concentrations （25, 50, 100, and 200μg/mL） caused remarkable hypoactivity in the light-dark test. Conclusion Low concentrations of GODs were relatively non-toxic. However, GQDs disrupt the progression of embryonic development at concentrations exceeding 50 μg/mL.

Toxicity of Multi-Walled Carbon Nanotubes,Graphene Oxide,and Reduced Graphene Oxide to Zebrafish Embryos

Objective This study was aimed to investigate the toxic effects of 3 nanomaterials, i.e. multi-walled carbon nanotubes （MWCNTs）, graphene oxide （GO）, and reduced graphene oxide （RGO）, on zebrafish embryos. Methods The 2-h post-fertilization （hpf） zebrafish embryos were exposed to MWCNTs, GO, and RGO at different concentrations （1, 5, 10, 50, 100 mg/L） for 96 h. Afterwards, the effects of the 3 nanomateria on spontaneous movement, heart rate, hatching rate, length of larvae, mortality, and malformations Is were evaluated. Results Statistical analysis indicated that RGO significantly inhibited the hatching of zebrafish embryos. Furthermore, RGO and MWCNTs decreased the length of the hatched larvae at 96 hpf. No obvious morphological malformation or mortality was observed in the zebrafish embryos after exposure to the three nanomaterials. Conclusion MWCNTs, GO, and RGO were all toxic to zebrafish embryos to influence embryos hatching and larvae length. Although no obvious morphological malformation and mortality were observed in exposed zebrafish embryos, further studies on the toxicity of the three nanomaterials are still needed.

Human Embryo Neuronal Culture <i>in Vitro</i>: A Model to Study Cellular Physiology, Receptors, Power and Toxicity of Cytostatic Drugs for Human Use

Neural cells cultures from human embryo brain of 9° - 11°W gestational age have been used to study ERα (Estrogens Receptor α) and to perform toxicity test for Mitomycin C and Methotrexate. Histochemical confirmation of cellular neuronal phenotype was based on histochemical evidence of NSE (Neuron Specific Enolase).The detection of ERα in neuronal cells was performed with a rabbit Monoclonal Antibody. ERα was absent both on neurons grown in vitro and on tissue brain specimens. This finding is apparently in contrast with the positive immunoreactivity of ERα and ERβ reported by other Authors on foetal and adult CNS (Central Nervous System). The absence of nuclear ERα on neurons in culture and in brain tissue specimens in our experiment is not in contrast with the relevant physiologic role of estrogens on nervous central system, but it could be correlated to the embryonic period of life and could represent a protection of male brain from an undue estrogens imprinting. The mitomycin C, alkylation agent, has shown in our experiment a major neurotoxic and cytostatic power in comparison with methotrexate. Our conclusion is that human embryo neuronal culture in vitro is a powerful instrument for physiology and human therapy for cancer and neurodegenerative diseases.

TOXICITY OF BISPHENOL A ON THE GROWTH OF ZEBRAFISH EMBRYOS

In order to evaluate the toxicity of the bisphenol A (BPA) on the growth of zebrafish embryos, fertilized eggs were exposed to the concentration of 2.00, 4.00, 6.00, 8.00, 10.00, 15.00, 18.00, 22.00 and 25.00mg/L BPA for 72 h at 26±1℃. The results revealed that the sublethal toxicological endpoints induced by BPA were:delayed hatch> blood balk >cyst>altered axial curvature and tail malformation. The median embryo lethal concentration (LC50) after 24 h was 16.36 mg/L. We concluded that the BPA toxicity on zebrafish embryos were caused before 8h exposure and it was not the result of long-term accumulation. Therefore, BPA maybe cause altered gene expression at the early stage of zebrafish embryos. In the further studies, we will use the technology of genetic chips to look for the toxic mechanism of BPA.

SD大鼠胚胎-胎仔发育毒性试验背景数据的建立

目的总结国家药物安全评价监测中心2013-2022年SD大鼠胚胎-胎仔发育毒性试验各指标的正常值范围,建立SD大鼠胚胎-胎仔发育毒性试验各指标的背景数据库,为药物胚胎-胎仔发育毒性评价提供参考。方法对本中心2013-2022年11项SD大鼠胚胎-胎仔发育毒性试验中对照组共计205只孕鼠和3037只胎鼠各项胚胎发育和胎仔生长发育指标进行统计分析,计算其平均数、标准差、变异系数和95%置信区间。指标包括孕鼠妊娠期体重和体重增长幅度、孕鼠摄食量、妊娠结局(妊娠率、平均黄体数、平均着床数、平均活胎数、活胎率、吸收胎率、死胎率)、胎仔生长发育情况(胎仔重、胎盘重、性别比)、胎仔外观异常率、内脏异常率和骨骼异常率。结果孕鼠妊娠期体重呈增长趋势,妊娠后期体重增长幅度明显增大。孕鼠摄食量随着妊娠时间的增加呈增长趋势。妊娠第20天进行剖腹产,妊娠率为93.2%,平均黄体数、着床数和活胎数分别为18.0±3.2,15.9±2.8和14.8±3.0,活胎率为93.4%,死胎率为6.6%;胎仔雄/雌性别比为0.94,平均体重为(3.6±0.3)g,胎盘平均重量为(0.6±0.3)g。胎仔外观异常发生率约为0.2%,内脏异常率约为0.8%。骨骼异常率约为1.2%,未骨化和骨化不全的发生率较高,主要发生于胸骨和舌骨等,胎仔的掌骨骨化数、跖骨骨化数和骶尾椎骨化数分别为7.0±0.7,8.0±0.1和7.4±0.5,第Ⅰ~Ⅳ胸骨骨化率较高,平均为98.6%~99.9%,第Ⅴ胸骨骨化率为(68.0±28.4)%,第Ⅵ胸骨骨化率为(82.8±23.9)%。结论初步建立了本GLP实验室SD大鼠胚胎-胎仔发育毒性试验中各指标背景数据库,为生殖毒性研究提供参考。

Toxic effects of several phthalate esters on the embryos and larvae of abalone Haliotis diversicolor supertexta

As the most widely used plasticizers in the world, phthalate esters （PAEs） are potential endocrine disruption compounds （EDCs）. In the present study, the toxicity of dimethyl phthalate （DMP）, diethyl phthalate （DEP）, dibutyl phthalate （DBP）, di （2-ethylhexyl） phthalate （DEHP） on embryogenesis and larvae development of the marine univalve Haliotis diversicolor supertexta was examined in laboratory. The results show that the malformation of embryos appeared during the experiment, such as embryos died or lysed, small transparent flocculent rings studded on the periphery of the embryo, and the larvae could failed to hatch. In embryo toxic test, embryos incubated at the highest concentration of DMR DEP and DBP solutions showed significantly high abnormal rate compared with the control, while DEHP solutions displayed no significant difference. In larval toxic test, in all concentrations of DMP, DEP and DBP solutions, larval settlement rates were low significantly than that of the control. Similarly, DEHP solutions show nearly no effect on the larval settlement. The order of toxicity on embryos and larvae is DBP〉DEP〉DMP〉DEHE Being a simple and easy stimulation to indoor spawn, sensitive to environmental factors, and short culture time, the embryos of H. diversicolor supertexta can be used to indicate toxicity of the PAEs.

Polystyrene nanoplastics aggravated ecotoxicological effects of polychlorinated biphenyls in on zebrafish(Danio rerio)embryos

In view of the accumulation of nanoplastics(NPs)in the food chain of environment and animals,and the good adsorption properties of nano-plastics to toxic substances,it is necessary to explore the influence of NPs in living organisms.In this study,single and joint toxicological effects of polystyrene nanoplastics(PS-NPs,size 80 nm)and polychlorinated biphenyls(PCBs),were explored in freshwater aquatic animal model zebrafish(Danio rerio).Our study found that exposure to single PS-NPs induced mild acute toxicity,albeit the combined exposure of PS-NPs and polychlorinated biphenyls aggravated the toxicity of PCBs in a dose-dependent manner.Results from gene expression profiling showed that NPs exposure could activate detoxification process,resulting in a slight up-regulation of antioxidant genes(sod1,gstp1),bone development genes(bmp2,bmp4)and cardiac gene(tbx20);while PCBs suppressed the detoxification through down-regulation of these genes,and the addition of NPs will exacerbate the impact of PCBs on gene suppression.Importantly,the results of in vivo purification experiments found that NPs showed prolonged retention in liver,intestine and gills of zebrafish and they might have crossed biological barrier and accumulate in lipid-rich tissues and excretion does not appear as the significant pathway for their elimination.In conclusion,the toxic effects of polychlorinated biphenyls on chorionic protected embryos were not significant as zebrafish chorion plays an important role in resisting the invasion of pollutants;PCBs can seriously damage the bone and heart development of zebrafish,while the presence of NPs significantly enhanced the toxicity of PCBs in zebrafish,which is an alarming concern for growing NPs levels and ecological safety in aquatic environment.

Comparative study on pharmacokinetics and toxicity of intravitreal and sub-Tenon injection of triamcinolone acetonide in ocular tissues

AIM:To compare the differences in kinetics,distribution,and toxicity of triamcinolone acetonide(TA)between the injection methods,sub-Tenon and intravitreal injections in rabbit ocular tissues.METHODS:TA was injected into the vitreous or the sub-Tenon in rabbits.For pharmacokinetic study,rabbits were sacrificed periodically and then TA in blood and ocular tissues(retina/choroids,vitreous,and aqueous humor)were measured over 91 d.For toxicological study,clinical signs,slit-lamp microscopic examination,ophthalmological test were performed.The eyeballs and surrounding tissues were collected and fixed with glutaraldehyde-formalin solution,and then paraffin embedded for histological investigation.RESULTS:Higher levels of TA were distributed in the intraocular tissues when injected into the vitreous compared to the sub-Tenon.Conversely,TA level was remarkably lower in the rabbits which received intravitreal TA injections than those treated with sub-Tenon injection throughout the study period in plasma.Optical discharge probably caused by systemic circulation of TA was observed by receiving sub-Tenon TA injection.Meanwhile,technicassociated toxicological ocular symptoms and findings were more frequently observed in intravitreal injection than in sub-Tenon injection.CONCLUSION:There are significant differences in kinetics and distribution of TA in vitreous body,aqueous humor and plasma,between the two injection methods.Although further study is needed to explain the species difference between human and rabbit,it is assumed that the difference in the frequency of intraocular pressure elevation and cataract formation by TA between the two injection methods are directly related to the TA concentrations in aqueous humor and vitreous body in each injection methods.Systemic toxicity and technic-associated toxicity are also closely related to kinetics of TA in plasma and each injection method itself,respectively.

A rapid absorbance-based growth assay to screen the toxicity of oligomer Aβ42 and protect against cell death in yeast

Multiple lines of evidence show that soluble oligomer forms of amyloidβprotein(Aβ42)are the most neurotoxic species in the brain and correlates with the degree of neuronal loss and cognitive deficit in Alzheimer’s disease.Although many studies have used mammalian cells to investigate oligomer Aβ42 toxicity,the use of more simple eukaryotic cellular systems offers advantages for large-scale screening studies.We have previously established and validated budding yeast,Saccharomyces cerevisiae to be a simple and a robust model to study the toxicity of Aβ.Using colony counting based methods,oligomeric Aβ42 was shown to induce dose-dependent cell death in yeast.We have adapted this method for high throughput screening by developing an absorbance-based growth assay.We further validated the assay with treatments previously shown to protect oligomer Aβ42 induced cell death in mammalian and yeast cells.This assay offers a platform for studying underlying mechanisms of oligomer Aβ42 induced cell death using gene deletion/overexpression libraries and developing novel agents that alleviate Aβ42 induced cell death.

A Photosensitivity Insecticide, 5-Aminolevulinic Acid, Exerts EffectiveToxicity to Oxya chinensis (Orthoptera: Acridoidea)

5-Aminolevulinic acid （ALA）, a major photosensitivity insecticide, has attracted increasing attention as a new type of highly efficient, environmental friendly pesticide to be used to control the pest. To examine whether or not ALA acts effectively to grasshopper, Oxya chinensis and elucidate the detoxification mechanism of ALA, the susceptibility to ALA was assessed in O. chinensis and two major metabolic detoxification enzymes including glutathione S-transferases （GSTs） and general esterases （ESTs）-specific activities were compared in different development stages and different body sections of O. chinensis treated by ALA and the control. The results showed that the ALA exhibited obvious toxicity to the grasshopper in different development stages. In the low-dose treatment （0.0597 mmol L-1）, the mortalities of O. chinensis reached a significant level （55.5% in the 1st instar nymphs, 61.4% in the 2nd instar nymphs, 71.4% in the 3rd instar nymphs, and 64.4% in the 4th instar nymphs. But, there was no dose-dependent toxic effect. Thereby, we proposed that ALA has the potential for acting as photosensitivity insecticide for controlling O. chinensis. GSTs activity assays using CDNB and DCNB as substrates indicated that the thorax and abdomen of the different instar nymphs treated by ALA showed 1.52-5.56 fold significantly increased GSTs activities compared with the control. However, for the ESTs-specific activity assay, there was no significant difference between O. chinensis treated by ALA and the control within different instar nymphs, when a-NA, a-NB and b-NA were used as substrates. Therefore, GSTs-mediated metabolic detoxification as evidenced by significantly increased GSTs activities might contribute to protect against oxidative damage and oxidative stress by ALA in O. chinensis.

十二烷基苯磺酸钠暴露对黄颡鱼(Pelteobagrus fulvidraco)胚胎发育毒性和仔鱼神经毒性的影响

该研究旨在探明十二烷基苯磺酸钠(SDBS)对黄颡鱼(Pelteobagrus fulvidraco)胚胎发育毒性和仔鱼神经毒性的影响,科学评估水体中SDBS污染的环境生态风险。将受精后4 h的黄颡鱼胚胎暴露于质量浓度为0、0.2、0.4、0.6、0.8 mg·L^(-1)的SDBS中,观察胚胎孵化累计死亡率、畸形率;并通过检测5日龄仔鱼脑组织中乙酰胆碱酯酶活性及相关基因的转录水平、5-羟色胺及相关基因的转录水平,探讨其神经毒性的潜在机制。结果显示,与对照相比,暴露处理的黄颡鱼胚胎孵化畸形率提高4.5~14.5百分点(P<0.05),死亡率提高7.8~23.4百分点(P<0.05)。与对照相比,暴露处理正常仔鱼和畸形仔鱼的乙酰胆碱酯酶活性分别显著降低12.0%~50.5%和15.0%~53.9%(P<0.05),暴露处理仔鱼乙酰胆碱酯酶基因mRNA转录水平下降;暴露处理正常仔鱼和畸形仔鱼5-羟色胺含量分别显著降低2.6%~9.9%和3.0%~11.1%(P<0.05),暴露处理仔鱼5-羟色胺基因的转录水平降低。上述结果表明,十二烷基苯磺酸钠暴露显著提高了黄颡鱼胚胎孵化的死亡率和畸形率;SDBS通过抑制乙酰胆碱酯酶活性和5-羟色胺含量水平影响神经传导,抑制神经递质相关基因表达,从而对黄颡鱼产生胚胎发育毒性及神经毒性作用。

Toxicity of Chemotherapy in a Patient with Bloom Syndrome＇s Diagnosis

Bloom＇s syndrome is a rare disease that is related to an increased risk of developing malignant neoplasm. The patient reported was followed up with several hospital staff when she was diagnosed with gastric cancer, but unfortunately, she had already peritoneal implants in moment of the surgery approach. It has been reported in the literature that patients with this syndrome present greater toxicity to the chemotherapeutic treatment, however due to the rarity of the disease, it is not known exactly how the adjustment of these drugs should be performed and which is the better protocol to use. Palliative chemotherapy was proposed, but after receiving one dose of the initially treatment, she developed severe and limiting toxicity.

Acute Toxicity and Antipyretic Activities of a Methanolic Extract of Alchornea cordifolia Leaves

Alchornea cordifolia (Euphorbiaceae) is a very prized plant among traditional healers in Africa. Its leaves are used for its antipyretic properties in traditional areas. The aim of our study is to determine the acute toxicity and the antipyretic activity of a methanolic extract of Alchornea cordifolia leaves. Acute toxicity was assessed by measuring mortality, changes in body weight, spontaneous movements, and normal rectal temperature in mice. Antipyretic activity was evaluated by brewer’s yeast-induced hyperpyrexia in rats according to Teotino method (1963). The antipyretic effect of methanolicextract of Alchornea cordifolia leaves was compared with paracetamol (100 mg/kg bw) orally. Groups of mice treated with doses of 6500;3250;1625 and 812.5mg/kg of the extract did not show any mortality, nor significant alteration of body weight, nor alteration of spontaneous movements. However, incomplete reversed dose-dependent hypothermic activity was observed with doses of 50.78;101.56;203.12;406.25;and 812.5 mg/kg p.o. of the extract, showing acute toxicity of this plant. In the antipyretic assay, the extract with doses of 50.78;101.56;203.12;406.25;and 812.5 mg/kg p.o. exhibited a significant dose-dependent antipyretic activity similar to paracetamol (100 mg/kg bw) in rats. Thus Alchornea cordifolia may inhibit prostaglandins-biosynthesis from hypothalamus. Our results support claims on its traditional uses in management of fever. However Alchornea cordifolia may affect hypothalamus not only during fever but also when body temperature is normal.

Creating New Germplasm by Distant Hybridization in Stone Fruits:Ⅱ-Embryo Rescue and Hybrid Identification Between Plum and Apricot

Embryo abortion stage and rescue system of hybrids were studied in the distant hybridizationbetween plum and apricot. Identification of the hybrids was also made. The resultsshowed: (1) Embryo abortion started from three weeks after pollination. (2) The germinationand growth of embryos were different at different growth stages, which could germinateand grow with PF value>0.5, but failed with PF value<0.5. In embryo rescue system ofhybrids, the best germination and differentiation medium was MS+6-BA 2mgL-1+IAA 0.3mgL-1,the rate of germination and differentiation reached up to 80%, bud induction andmultiplication medium was MS+6-BA 1.5mgL-1+IAA 0.3mgL-1, rooting medium was 1/2 MS+IAA0.8mgL-1. Some hybrids were transplanted into the field successfully. (3) Leaf shapeinvestigation and identification by S allele-specific PCR and RAPDs showed that thehybrids were true ones.

Toxic tau: structural origins of tau aggregation in Alzheimer’s disease

Alzheimer’s disease is characterized by the extracellular accumulation of the amyloidβin the form of amyloid plaques and the intracellular deposition of the microtubule-associated protein tau in the form of neurofibrillary tangles.Most of the Alzheimer’s drugs targeting amyloidβhave been failed in clinical trials.Particularly,tau pathology connects greatly in the pathogenesis of Alzheimer’s disease.Tau protein enhances the stabilization of microtubules that leads to the appropriate function of the neuron.Changes in the quantity or the conformation of tau protein could affect its function as a microtubules stabilizer and some of the processes wherein it is involved.The molecular mechanisms leading to the accumulation of tau are principally signified by numerous posttranslational modifications that change its conformation and structural state.Therefore,aberrant phosphorylation,as well as truncation of tau protein,has come into focus as significant mechanisms that make tau protein in a pathological entity.Furthermore,the shape-shifting nature of tau advocates to comprehend the progression of Alzheimer’s disease precisely.In this review,we emphasize the recent studies about the toxic and shape-shifting nature of tau in the pathogenesis of Alzheimer’s disease.

Activation of Uterine Smad3 Pathway Is Crucial for Embryo Implantation

Embryo implantation is a complicated physiological process tightly regulated by multiple biological molecules including growth factors.Transforming growth factor-betas(TGF-βs)and their most specific signal transduction factors,Smads,are expressed in the endometrium during the window of implantation.Recent researches indicated that Smad dependent TGF-β signaling may play an important role in the process of embryo implantation.In this study,we measured the expression of TGF-β1,TGF-β receptor type I(TpRI),Smad3 and p-Smad3 in the endometrium of mice and observed their elevation on day 4,5 and 6 of pseudopregnancy.Then we administrated a specific Smad3 inhibitor(Sis3)into the uterine cavity of mice on day 3 of pregnancy.The results showed a reduction in insulin-like growth factor-1(IGFBP-1)expression and the decreased number of implanted embryo after the administration.In addition,Sis3 was found to reduce the IGFBP-1 secretion in decidualized endometrial stromal cells.Taken all together,our findings demonstrated that TGF-β/Smad3 signaling is involved in the process of embryo implantation.

Total saponins of Panax ginseng effects on proliferation and differentiation of human embryonic neural stem cells and in a Parkinson's disease mouse model

BACKGROUND： Total saponins of Panax ginseng （TSPG） exhibits neuroprotection against Parkinson＇s disease in the substantia nigra. OBJECTIVE： To investigate the effects of TSPG on human embryonic neural stem cells （NSCs） proliferation and differentiation into dopaminergic neurons using in vitro studies, and to observe NSC differentiation in a mouse model of Parkinson＇s disease, as well as behavioral changes before and after transplantation. DESIGN, TIME AND SETTING： In vitro neural cell biology trial and in vivo randomized, controlled animal trial were performed at the Institute of Basic Medical Sciences, Chongqing Medical University between September 2004 and December 2007. MATERIALS： TSPG （purity 〉 95%） was isolated, extracted, and identified by Chongqing Academy of Chinese Materia Medica. Recombinant human basic fibroblast growth factor （bFGF） and recombinant human epidermal growth factor （EGF） were purchased from PeproTech, USA. A total of 25 C57/BL6J mice, aged 18-20 weeks were included. Twenty were used to establish a Parkinson＇s disease model with i.p. injection of MPTP （1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine） and TSPG alone or combined with interleukin-1 （IL-1）-treated NSCs prior to transplantation into the corpus striatum. The remaining five mice were pretreated for 3 days with TSPG prior to MPTP injection, serving as the TSPG prevention group. METHODS： Primary NSCs were isolated, cultured and purified from embryonic cerebral cortex. Immunocytochemistry was employed to detect specific antigen expression in the NSCs. In vitro experiment： （1） to induce proliferation, NSCs were treated with TSPG, EGF＋bFGF, or TSPG＋EGF＋bFGF, respectively; （2） to induce dopaminergic neuronal differentiation, NSCs were treated with TSPG, IL-1, or TSPG＋IL-1, respectively. MAIN OUTCOME MEASURES： In vitro experiment： the effects of TSPG on NSCs proliferation were evaluated with flow cytometry and MTT assay. Tyrosine hydroxylase expression was determined by immunocytochemistry assay to observe effects of TSPG on dopaminergic neuronal differentiation. In vivo experiment： differentiation of grafted NSCs in the mouse brain was determined by immunohistochemical staining. Behavioral changes were evaluated by spontaneous activity frequency, memory function, and score of paralysis agitans. RESULTS： （1） NSCs were cultured and passaged for more than three passages. Immunocytochemistry revealed positive nestin staining, as well as neurofilament protein and glial fibrillary acidic protein. （2） TSPG significantly increased NSC proliferation, in particular when combined with EGF and bFGF, which was twice as effective as FGF or bFGF alone. TSPG also induced dopaminergic differentiation in NSCs, in particular when TSPG was added together with IL-1, resulting in an effect five times greater than that of IL-1 alone. （3） At day 30 following transplantation, most NSCs in the TSPG prevention group differentiated into dopaminergic neurons, and the scores of paralysis agitans, spontaneous activity, and memory function were significantly increased compared with TSPG alone or TSPG＋IL-1 groups （P 〈 0.05）. CONCLUSION： TSPG stimulated NSC proliferation, in particular when combined with FGF and bFGF. TSPG significantly induced dopaminergic neuronal differentiation of NSCs, and the effect was greater when combined with IL-1. In addition, TSPG greatly improved behavior in the Parkinson＇s disease mouse model following NSC transplantation. Following NSC transplantation, TSPG pretreatment exhibited superior efficacy over either TSPG alone or TSPG in combination with IL-1, in terms of behavioral improvements in the Parkinson＇s disease mouse model.

Neuroprotective effects of human telomerase reverse transcriptase on beta-amyloid fragment 25-35-treated human embryonic cortical neurons

BACKGROUND： Numerous current studies have suggested that human telomerase reverse transcriptase （hTERT） gene has neuroprotective effects and can inhibit apoptosis induced by various cytotoxic stresses; however, the mechanism of action remains unknown. OBJECTIVE： To evaluate the neuroprotective effects and possible mechanism of action of hTERT gene transfection in human embryonic cortical neurons treated with beta-amyloid fragment 25-35 （AI325-35）. DESIGN, TIME AND SETTING： The randomized, controlled and molecular biological studies were performed at the Department of Anatomy and Brain Research, Zhongshan School of Medicine, Sun Yat-sen University, China, from September 2005 to June 2008. MATERIALS： AdEasy-1 Expression System was gifted by Professor Guoquan Gao from Sun Yat-Sen University, China. Human cortical neurons were derived from 12-20 week old aborted fetuses, obtained from the Guangzhou Maternal and Child Health Hospital, China. Mouse anti-Odk5 and mouse anti-p16 monoclonal antibodies （Lab Vision, USA）, and mouse anti-hTERT monoclonal antibody （Epitomics, USA）, were used in this study. METHODS： （1） Recombinant adenovirus vectors, encoding hTERT （Ad-hTERT） and green fluorescent protein （Ad-GFP）, were constructed using the AdEasy-1 Expression System. Human embryonic cortical neurons in the Ad-hTERT group were transfected with Ad-hTERT for 1-21 days. Likewise, human embryonic cortical neurons in the Ad-GFP group were transfected with Ad-GFP for 1-21 days. Human embryonic cortical neurons in the control group were cultured as normal. （2） Human embryonic cortical neurons in the Ad-hTERT group were treated with 10 pmol/L Aβ25-35 for 24 hours. Normal human embryonic cortical neurons treated with 10 pmol/Lβ25.35 for 24 hours served as a model group. Human embryonic cortical neurons in the Ad-GFP and control groups were not treated with Aβ25-35. MAIN OUTCOME MEASURES： Expression of hTERT in human embryonic cortical neurons was evaluated by immunocytochemical staining and Western blot assay. Telomerase activity was measured using a PCR-based telomeric repeat amplification protocol （TRAP） ELISA kit. Neural activity in human embryonic cortical neurons was examined by MTT assay; apoptosis was measured using TUNEL assay; and Cdk5 and p16 protein expressions were measured by Western blot. RESULTS： Expression of hTERT protein was significantly increased and peaked at day 3 post-transfection in the Ad-hTERT group. No hTERT expression was detected in the Ad-GFP and control groups. Telomerase activity was significantly greater in the Ad-hTERT group compared with the Ad-GFP and control groups （P 〈 0.01）. Compared with the control group, cell activity was significantly decreased （P 〈 0.05）, and cell apoptotic rate, Cdk5 and p16 expression were significantly increased （P 〈 0.01） in the model group. Compared with the model group, cell activity was increased in the Ad-hTERT group, and peaked at day 3 post-transfection （P 〈 0.05）. Neuroprotective effects also peaked at day 3 post-transfection; and the apoptotic rate, Cdk5 and p16 expression significantly decreased （P 〈 0.01）. CONCLUSION： Expression of hTERT in human embryonic cortical neurons can relieve Aβ25-35-induced neuronal apoptosis. The possible mechanism by which hTERT produces these neuroprotective effects may be associated with inhibition of Cdk5 and p16 expression.

Preparation and analysis of active rat model of rheumatoid arthritis with features of TCM toxic heat-stasis painful obstruction

Objective:To establish a collagen type II-induced rat model of rheumatoid arthritis(RA)presenting characteristics of the human form of the traditional Chinese syndrome pattern of toxic heat-stasis painful obstruction(bi zheng;arthromyodynia)as well as pathologic features of active RA.The Chinese herbal medicine Tengmei decoction was used to validate the animal model.Methods:Ninety specific pathogen free Sprague-Dawley rats were randomly divided into a normal group of 6 rats and a model group of 84 rats.To establish the rat model of collageninduced arthritis(CIA),bovine type II collagen in complete Freund’s adjuvant was injected into the model group rats as a priming dose(Day 0)and boosting dose(Day 9).Changes in arthritic index(AI)scores,including limb swelling,were monitored.Thereafter,24 successfullyestablished CIA rats were randomly assigned to 4 groups with 6 animals each:model,positive control drug,high-dose traditional Chinese herbal medicine,and traditional Chinese herbal medicine.A blank control group of 6 rats was included.After 12 weeks of intervention with Tengmei decoction,articular synovial tissue and serum specimens were collected to detect interleukin-2(IL-2)and IL-17 transcription and protein expression levels.

Preliminary Validation of Tumor Cell Attachment Inhibition Assay for Developmental Toxicants With Mouse S180 Cells

This study was designed to explore the possibility of using ascitic mouse sarcoma cell line (S180) to validate the mouse tumor cell attachment assay for developmental toxicants, and to test the inhibitory effects of various developmental toxicants. The results showed that 2 of 3 developmental toxicants under consideration, sodium pentobarbital and ethanol, significantly inhibited S180cells attachment to Concanavalin A-coaed surfaces. Inhibition was dependent on concentration, and the IC50 (the concentration tha reduced attachment by 50% ), of these 2 chemicals was 1.2×10-3mol/L and 1 .0 mol/L, respectively. Anoher developmental toxiant, hydmiortisone, did not show inhibitory activity. Two non-developmental toxicants, sodium chloride and glycine were also tested and these did not decrease attachment rates. The main results reported here were generally sindlar to those obtained with ascitic mouse ovdrian tumor cells as a model. Therefore, this study added further evidence to the conclusion that cell specificity does not lindt attachment inhibition to Con A-coated surfaces, so S180 cell may serve as an altemative cell model, especially when other cell lines are unavailable. Furthermore, after optimal validation, it can be suggested that an S180 cell attachment assay may be a candidate for a series of assays to detect developmental toxicants.