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191.

Background and aims

Osteoporosis, which is a disease characterized by weakening of the bone, affects a large portion of the senior population. The current therapeutic options for osteoporosis have side effects, and there is no effective treatment for severe osteoporosis. Thus, we urgently need new treatment strategies, such as topical therapies and/or safe and effective stem cell therapies.

Methods

We investigated the therapeutic potential of directly injecting human tonsil-derived mesenchymal stem cells (TMSC) into the right proximal tibias of ovariectomized postmenopausal osteoporosis model mice. Injections were given once (1×) or twice (2×) during the 3-month experimental period. At the end of the experiment, micro-computed tomographic images revealed some improvement in the proximal tibias and more significant improvement in the femoral heads of treated mice.

Results

Osteogenic effect was qualitatively and quantitatively more pronounced in TMSC/2×-treated mice. Furthermore, TMSC/2×?mice exhibited significant recovery of the serum osteocalcin level, which is pathologically elevated in osteoporosis, and increased serum alkaline phosphatase, which indicates bone formation. TMSC therapy was generally well tolerated and caused no apparent toxicity in the experimental mice. Moreover, TMSC therapy reduced visceral fat.

Conclusion

Our results demonstrate that double injection of TMSC directly into the proximal tibia triggers recovery of osteoporosis, and thus could be a potential therapeutic approach for severe bone loss.  相似文献   
192.
GeneticEngineeringofTobaccowithDoubleResistancetoBothVirusandInsectLIANGXiao-you;(梁晓友)MIJing-jiu;(米景九),PanNai-sui(潘乃隧),CHENzh...  相似文献   
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We investigated the cytotoxic, neurotoxic, apoptotic and antiproliferative effects of extracts from Petalonia fascia, Jania longifurca and Halimeda tuna on the MCF-7 breast cancer cell line. J. longifurca extracts were more toxic than those of P. fascia and H. tuna. The algal extracts showed significant toxic effects at different dilutions. The toxic effects were due to increased oxidative stress and resulted in apoptosis. Algal toxicity may exert negative effects through the food chain or by direct interaction. Algal toxicity also has potential for cancer therapy. The toxic effects that we observed may be especially important for therapy for breast tumors.  相似文献   
197.
ABSTRACT We investigated feeding by phototrophic red‐tide dinoflagellates on the ubiquitous diatom Skeletonema costatum to explore whether dinoflagellates are able to feed on S. costatum, inside the protoplasm of target dinoflagellate cells observed under compound microscope, confocal microscope, epifluorescence microscope, and transmission electron microscope (TEM) after adding living and fluorescently labeled S. costatum (FLSc). To explore effects of dinoflagellate predator size on ingestion rates of S. costatum, we measured ingestion rates of seven dinoflagellates at a single prey concentration. In addition, we measured ingestion rates of the common phototrophic dinoflagellates Prorocentrum micans and Gonyaulax polygramma on S. costatum as a function of prey concentration. We calculated grazing coefficients by combining field data on abundances of P. micans and G. polygramma on co‐occurring S. costatum with laboratory data on ingestion rates obtained in the present study. All phototrophic dinoflagellate predators tested (i.e. Akashiwo sanguinea, Amphidinium carterae, Alexandrium catenella, Alexandrium tamarense, Cochlodinium polykrikoides, G. polygramma, Gymnodinium catenatum, Gymnodinium impudicum, Heterocapsa rotundata, Heterocapsa triquetra, Lingulodinium polyedrum, Prorocentrum donghaiense, P. micans, Prorocentrum minimum, Prorocentrum triestinum, and Scrippsiella trochoidea) were able to ingest S. costatum. When mean prey concentrations were 170–260 ng C/ml (i.e. 6,500–10,000 cells/ml), the ingestion rates of G. polygramma, H. rotundata, H. triquetra, L. polyedrum, P. donghaiense, P. micans, and P. triestinum on S. costatum (0.007–0.081 ng C/dinoflagellate/d [0.2–3.0 cells/dinoflagellate/d]) were positively correlated with predator size. With increasing mean prey concentration of ca 1–3,440 ng C/ml (40–132,200 cells/ml), the ingestion rates of P. micans and G. polygramma on S. costatum continuously increased. At the given prey concentrations, the maximum ingestion rates of P. micans and G. polygramma on S. costatum (0.344–0.345 ng C/grazer/d; 13 cells/grazer/d) were almost the same. The maximum clearance rates of P. micans and G. polygramma on S. costatum were 0.165 and 0.020 μl/grazer/h, respectively. The calculated grazing coefficients of P. micans and G. polygramma on co‐occurring S. costatum were up to 0.100 and 0.222 h, respectively (i.e. up to 10% and 20% of S. costatum populations were removed by P. micans and G. polygramma populations in 1 h, respectively). Our results suggest that P. micans and G. polygramma sometimes have a considerable grazing impact on populations of S. costatum.  相似文献   
198.
玉米SSR连锁图谱构建及叶面积的QTL定位   总被引:4,自引:0,他引:4  
刘建超  褚群  蔡红光  米国华  陈范骏 《遗传》2010,32(6):625-631
叶片是玉米进行光合作用的主要器官,叶面积的大小(尤其是穗三叶面积)对于玉米干物质的积累及产量形成起着至关重要的作用。研究玉米叶面积的遗传基础对于指导玉米高产育种具有理论意义。文章以两个叶面积差异显著的亲本478×武312为基础材料所构建的218个F8代的重组自交系为作图群体,构建了一张包含184个SSR标记的遗传连锁图谱,图谱总长度为2084.1cM,平均图距为11.3cM。通过两年的田间试验对玉米叶面积(穗三叶)进行了QTL定位分析。两年共定位到7个和叶面积相关的QTL位点,2006年定位到4个QTL位点;2007年定位到3个QTL位点。在第2染色体umc1542-umc1518标记区间发现一个主效QTL位点,该位点可以在两年同时检测到,两年分别解释12.5%和17.3%的表型变异。该位点能稳定地检测到且具有较大的贡献率,可能会在玉米叶面积分子标记辅助选择上有所应用。  相似文献   
199.
转抗虫基因三倍体毛白杨植株体内农杆菌残存与逃逸   总被引:5,自引:0,他引:5  
杨敏生  米丹  D. Ewald  王颖  梁海永  甄志先 《生态学报》2006,26(11):3555-3561
用部分改造的BtCry1Ac基因与慈菇蛋白酶抑制剂(APLA)基因构建的双抗虫基因表达载体,通过农杆菌介导法对三倍体毛白杨进行了转化,对转化后植株体内残存农杆菌在继代培养和移栽过程中进行了跟踪检测。结果表明:通过对转化再生植株的分子生物学检测,42个株系中,33个株系为阳性,阳性率达到80%;用Bt毒蛋白抗血清进行ELSA检测结果表明,7个转基因株系都有Bt杀虫蛋白表达;基因转化后,可采用附加50mg/L卡那霉素,300mg/L羧苄青霉素的筛选培养基消除细菌并进行抗性芽筛选。对28个转基因株系叶片、茎段和根段在含有卡那霉素50mg/LYEB培养基上进行细菌培养,通过在T-DNA区、质粒Vir区和农杆菌基因组设计引物,进行PCR检测,证明有3个株系(33、37、5号)检测到残存工程农杆菌,并在组培瓶中存活24个月。将带菌的3个株系组培苗移栽到花盆中,室内培养1个月后,在33号株系根际土壤中检测到了目的农杆菌。  相似文献   
200.
结核分枝杆菌基因分型VNTR-MIRU方法是近年来结核病分子流行病学研究的热点,已广泛应用于TB流行病学研究的各个领域,包括调查爆发流行,追踪传染源,调查优势菌株以及传播机制等方面.VNTR-MIRU分型方法简单快速,是一种有效的结核分枝杆菌基因型分型方法.  相似文献   
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