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1.
背景:肾上腺髓质素基因转染能增强骨髓间充质干细胞在缺血、缺氧环境下的抗凋亡能力,但其机制尚未完全明确。 目的:观察肾上腺髓质素对骨髓间充质干细胞缺血、缺氧时Bax、Bcl-2和Caspase-3等凋亡相关调节蛋白表达的影响。 方法:贴壁法分离、培养、纯化SD大鼠骨髓间充质干细胞,缺氧、无血清培养0,3,6,9,12 h后用Western blot测定Bax、Bcl-2、Caspase-3蛋白的表达以确定最佳缺氧时间。采用缺氧6 h为时间点,根据缺氧、无血清培养前是否进行肾上腺髓质素预处理分为对照组(未加入肾上腺髓质素)及肾上腺髓质素不同质量浓度组(1,10,100 μg/L),然后采用Western blot测定Bax、Bcl-2、Caspase-3蛋白的表达。 结果与结论:①无血清培养条件下缺氧0,3,6,9,12 h后骨髓间充质干细胞 Bax、Bcl-2表达均增加(P < 0.05),缺氧6 h时Bax/Bcl-2比值、caspase-3蛋白达到最小(P < 0.05)。②缺氧6 h时,与1,10 μg/L肾上腺髓质素组相比,100 μg/L肾上腺髓质素组表达Bax蛋白、Caspase-3蛋白最低,Bax/Bcl-2比值最低,而表达Bcl-2蛋白最高(P < 0.05)。结果表明肾上腺髓质素能降低无血清、缺氧条件下骨髓间充质干细胞Bax/Bcl-2比值、Caspase-3蛋白表达,该效应存在剂量依赖性。  中国组织工程研究杂志出版内容重点:干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程  相似文献   

2.
背景:基因转染可以提高骨髓间充质干细胞在移植区的存活,但目前对肾上腺髓质素基因转染骨髓间充质干细胞在缺氧条件下增殖、凋亡及分泌情况的研究很少。目的:观察肾上腺髓质素基因转染对骨髓间充质干细胞在缺氧及无血清培养条件下增殖、凋亡、分泌血管内皮生长因子的影响。方法:贴壁法体外分离、扩增培养大鼠骨髓间充质干细胞。用x-gal染色测含肾上腺髓质素基因的重组腺病毒Ad-ADM对骨髓间充质干细胞的感染率。骨髓间充质干细胞分为未转染组、空载体组、Ad-ADM转染组。在缺氧、无血清条件下进行骨髓间充质干细胞的培养,在缺氧0,3,6,9,12,16,20,24hCCK-8法检测细胞增殖情况,ELISA法检测检测细胞上清液肾上腺髓质素及血管内皮生长因子表达,TUNEL法检测细胞凋亡情况。结果与结论:重组腺病毒对骨髓间充质干细胞的转染率与病毒感染复数具有量效关系,病毒感染复数为150时细胞的感染率达95.4%。缺氧、无血清培养条件下,3组骨髓间充质干细胞均出现生长抑制、凋亡增加,但是肾上腺髓质素基因转染组于0,3,6,9,12,16h细胞凋亡率显著低于其他两组(P﹤0.05)。缺氧9,12h,骨髓间充质干细胞分泌肾上腺髓质素及血管内皮生长因子达到高峰,且Ad-ADM转染组显著增高于其他两组(P﹤0.05)。提示在缺氧、无血清培养条件下(20h),肾上腺髓质素基因转染可增强骨髓间充质干细胞抗凋亡能力,这可能与肾上腺髓质素、血管内皮生长因子表达增加有关。  相似文献   

3.
背景:骨髓间充质干细胞移植入缺血心肌后存活率低,而低氧有可能增强骨髓间充质干细胞的增殖,促进其存活。 目的:体外模拟心肌细胞缺血微环境,探索低氧预处理后,骨髓间充质干细胞对持续缺氧诱导的心肌细胞凋亡的保护作用。 方法:取第4代SD大鼠骨髓间充质干细胞用于制备条件培养液。取胚胎大鼠心肌细胞株,随机分成4组:对照组:心肌细胞正常培养组;模型组:心肌细胞单纯缺氧;骨髓间充质干细胞组:心肌细胞与骨髓间充质干细胞条件培养液共缺氧;低氧组:心肌细胞与骨髓间充质干细胞低氧条件培养液共缺氧。MTT检测各组细胞活力变化,Annexin V-FITC双染标记心肌细胞凋亡,免疫组化检测各组Bax和Bcl-2蛋白的表达。 结果与结论:免疫组化显示,低氧组的Bcl-2表达较其他各组增强,而Bax的表达比模型组和骨髓间充质干细胞组减弱,Bcl-2/Bax比值最大。与对照组和骨髓间充质干细胞组相比,低氧组的细胞活力高(P < 0.05),凋亡率降低(P < 0.05)。提示低氧可能是通过增强旁分泌机制,从而对Bax和Bcl-2进行调节,对心肌细胞凋亡有保护效应。  相似文献   

4.
背景:研究表明体外培养细胞加入胸腺素β4能增加细胞的抗凋亡能力,若在缺氧环境中上调胸腺素β4基因在骨髓间充干细胞中的表达,其抗凋亡能力如何改变,目前鲜见报道。目的:观察胸腺素β4基因修饰的骨髓间充质干细胞在缺氧环境中的凋亡率改变,并探讨其是否通过调控Bax、Bcl-2表达影响凋亡能力。方法:将携带有胸腺素β4基因的慢病毒转染骨髓间充质干细胞,转染完毕后利用Western blot法检测胸腺素β4在骨髓间充质干细胞中的表达。将细胞分为胸腺素β4转染组、对照病毒组、未转染组,分别置于缺氧环境中。流式细胞仪检测3组细胞凋亡率;Western blot法检测3组细胞中Bax和Bcl-2蛋白表达情况。结果与结论:Western blot检测结果示,胸腺素β4基因在骨髓间充质干细胞中成功表达。流式细胞仪结果示,胸腺素β4转染组细胞凋亡率较对照病毒组、未转染组低,而对照病毒组、未转染组凋亡率差异无显著性意义。Western blot结果显示,Bcl-2蛋白在胸腺素β4转染组中表达量较对照病毒组、未转染组高,Bax蛋白在胸腺素β4转染组表达量较对照病毒组、未转染组低,而对照病毒组、未转染组中Bax、Bcl-2表达差异无显著性意义。提示过表达胸腺素β4基因可增加骨髓间充质干细胞在缺氧环境中的抗凋亡能力,其可能的作用机制是调控Bax和Bcl-2蛋白表达水平。  相似文献   

5.
背景:研究miR-378对缺血缺氧条件下骨髓间充质干细胞生长增殖、细胞凋亡等生物学行为的影响,为进一步改善骨髓间充质干细胞在梗死心肌中的生存提供新方法。 目的:观察miR-378转染后的骨髓间充质干细胞耐受缺血缺氧及促进血管形成的能力。 方法:体外培养的骨髓间充质干细胞分为未转染组和转染组,未转染组为未转染miR-378的骨髓间充质干细胞,转染组则采用化学合成的miR-378模拟物转染SD大鼠骨髓间充质干细胞;将两组骨髓间充质干细胞置于缺血缺氧(无血清,体积分数为1%O2、5%CO2,94%N2)环境中培养24 h后,应用锥虫蓝染色计数法、MTS法检测两组细胞在不同时间点的生长及增殖情况,TUNEL法检测细胞凋亡情况;将两组缺血缺氧后的培养基上清液分别刺激人脐静脉内皮细胞,观察血管形成情况。 结果与结论:缺血缺氧干预后48 h和72 h,转染组的骨髓间充质干细胞活细胞数明显高于未转染组(均为P < 0.01);转染组的骨髓间充质干细胞表现出较高的增殖能力,缺血缺氧干预后24 h及48 h细胞增殖升高较未转染组明显,差异有显著性意义(P < 0.01,P < 0.05);缺血缺氧后转染组骨髓间充质干细胞的凋亡比例明显下降(P < 0.05)。两组细胞均可促进血管腔样结构形成,但转染组血管管腔样结构较未转染组显著增多(P < 0.01)。研究结果提示miR-378可促进缺血缺氧后骨髓间充质干细胞的生长增殖并抑制其在缺血缺氧条件下的细胞凋亡,同时可提高其促血管生成的能力。中国组织工程研究杂志出版内容重点:干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接:  相似文献   

6.
背景:转化生长因子β1可促进骨髓间充质干细胞迁移及增殖,但机制尚不清楚。 目的:观察转化生长因子β1对体外培养的骨髓间充质干细胞侵袭力的影响,以及对Snail、基质金属蛋白酶2表达的调节作用。 方法:采用密度梯度离心结合贴壁法分离、培养大鼠骨髓间充质干细胞。用改良的Transwell小室检测0,0.5,1,2,5,10 μg/L的转化生长因子β1对细胞迁移的影响。用脂质体转染针对Snail基因的特异性小分子干扰RNA至骨髓间充质干细胞,观察转染前后Snail和基质金属蛋白酶2 的表达。 结果与结论:外源性转化生长因子β1对骨髓间充质干细胞迁移的促进作用具有剂量依赖性,在2 μg/L时达到最高。在此浓度下,Snail、基质金属蛋白酶2 mRNA表达明显增高。Snail基因沉默可以明显抑制转化生长因子β1对基质金属蛋白酶2表达的促进作用。提示转化生长因子β1可通过促进骨髓间充质干细胞基质金属蛋白酶2的表达提高其迁移能力,此作用与上调Snail表达有关。  相似文献   

7.
背景:骨髓间充质干细胞可以分化为心肌细胞,促进血管再生,但在移植早期其自身分泌的细胞因子不足以维持良好的分化和再生。 目的:验证腺病毒介导的肝细胞生长因子和血管内皮生长因子双基因转染新西兰兔骨髓间充质干细胞移植对新西兰兔梗死心肌组织的修复重建和血管再生的影响。 方法:腺病毒介导肝细胞生长因子/血管内皮生长因子双基因转染BrdU标记的新西兰兔骨髓间充质干细胞。取新西兰兔50只建立急性心肌梗死模型,4周后随机分为5组,分别于梗死心肌内注射:①骨髓间充质干细胞/Ad.血管内皮生长因子+肝细胞生长因子。②骨髓间充质干细胞/Ad. 肝细胞生长因子。③骨髓间充质干细胞/Ad.血管内皮生长因子。④骨髓间充质干细胞。⑤对照组注射等量无血清IMDM培养液。移植4周后观察移植细胞的分化和新生血管的形成,并通过超声多普勒检测心功能变化。 结果与结论:除对照组外,其余4组兔心功能都较移植前有明显改善(P < 0.05),其中移植双基因转染骨髓间充质干细胞/Ad.血管内皮生长因子+肝细胞生长因子组兔的心功能改善程度要明显高于其他3组。部分BrdU染色阳性的细胞可以分化成为内皮细胞,参与构成了梗死区域的新生毛细血管。与对照组比较,其余4组都有明显的血管新生(P < 0.05),而以骨髓间充质干细胞/Ad.血管内皮生长因子+肝细胞生长因子组最显著。提示肝细胞生长因子/血管内皮生长因子双基因转染新西兰兔骨髓间充质干细胞移植于梗死心肌可以促进心肌再生和新生血管的形成,明显改善心功能。 关键词:基因转染;骨髓间充质干细胞;血管内皮生长因子;肝细胞生长因子;移植 doi:10.3969/j.issn.1673-8225.2012.10.029  相似文献   

8.
背景:近来研究发现骨髓间充质干细胞移植后短期心功能受益主要是因为其可分泌多种细胞因子,促进了内生性修复过程,而不是心肌细胞的再生。目的:观察骨髓间充质干细胞旁分泌途径对阿霉素损伤心肌细胞凋亡的影响。方法:体外培养的乳鼠心肌细胞按3×108L-1浓度加入6孔培养板,3mL/孔,培养72h后分为3组:阿霉素损伤组、共培养组加入1mg/L阿霉素作用4h建立心肌细胞损伤模型,正常对照组不进行任何干预。共培养组取培养至第3代大鼠骨髓间充质干细胞,调整细胞浓度为3×108L-1,以3mL/孔加入共培养插件Millicell装置中,预培养24h,在造模后将Millicell装置插入到预先培养心肌细胞的6孔培养板中,建立共培养体系。检测条件培养基内细胞因子的质量浓度变化,骨髓间充质干细胞对阿霉素损伤心肌细胞Caspase-9和Caspase-3活性、细胞凋亡、Bcl-2和Bax蛋白表达的影响。结果与结论:与正常对照组比较,阿霉素损伤组胰岛素样生长因子1及肝细胞生长因子的质量浓度、心肌细胞Caspase-3及Caspase-9活性、心肌细胞凋亡率、心肌细胞Bax蛋白表达均明显升高(P0.05),Bcl-2蛋白表达明显降低(P0.05)。与阿霉素损伤组比较,共培养组胰岛素样生长因子1及肝细胞生长因子的质量浓度、心肌细胞Bcl-2蛋白表达均明显升高(P0.05),心肌细胞Caspase-3及Caspase-9活性、心肌细胞凋亡率、心肌细胞Bax蛋白表达均明显降低(P0.05)。结果证实骨髓间充质干细胞在损伤环境下细胞因子分泌增加,并可通过旁分泌途径抑制阿霉素诱导的心肌细胞凋亡。  相似文献   

9.
背景:骨形态发生蛋白2及转化生长因子β是骨再生中重要的因子,提高其表达可促进骨髓间充质干细胞的成骨分化。 目的:构建携带转化生长因子β3和骨形态发生蛋白2基因的慢病毒载体,观察其在骨髓间充质干细胞中的表达情况。 方法:应用重组慢病毒技术构建同时携带转化生长因子β3、骨形态发生蛋白2和绿色荧光蛋白基因的重组慢病毒表达载体,并用其转染体外培养的第3代兔骨髓间充质干细胞,以转染携带转化生长因子β3或骨形态发生蛋白2单一基因的慢病毒或单独慢病毒的骨髓间充质干细胞作为对照。转染后1周分别提取各组细胞的总RNA和蛋白进行检测。 结果与结论:荧光显微镜下见转染转化生长因子β3和(或)骨形态发生蛋白2基因3 d的骨髓间充质干细胞发绿色荧光,转染效率达90%以上。RT-PCR和Western blot结果显示,转染转化生长因子β3和骨形态发生蛋白2基因的骨髓间充质干细胞转化生长因子β3和骨形态发生蛋白2 mRNA和蛋白的表达均高于单一基因转染组及空白对照组。可见应用慢病毒可成功将转化生长因子β3和骨形态发生蛋白2基因转染至骨髓间充质干细胞并实现其高效表达,且两种基因具有协同促表达作用。  相似文献   

10.
背景:骨髓间充质干细胞是最好的组织工程种子细胞来源,含有血管内皮生长因子165(vascular endothelial growth factor 165,VEGF165)不仅对血管再生和启动成骨修复有重要意义,其持续稳定的释放还能够提高新生骨的矿化程度,增强修复组织的力学性能。 目的:观察hVEGF165基因转染的兔骨髓间充质干细胞分泌血管内皮生长因子的蛋白功能。 方法:体外分离、培养兔骨髓间充质干细胞,纯化并鉴定兔骨髓间充质干细胞;免疫荧光法检测细胞表面标志;传代培养后的骨髓间充质干细胞以pcDNA3.1-VEGF165质粒和脂质体1∶3比例的混合液转染,并分为3组:转染组应用pcDNA3.1-VEGF165转染细胞,空载体转染组应用pcDNA3.1-空载体转染,未转染组不处理。通过ELISA和Western-blot检测转染后细胞中外源性血管内皮生长因子的表达。 结果与结论:转染组与其他两组比较,VEGF165蛋白含量显著增高,差异有显著性意义(P < 0.05),但空载体转染组与未转染组之间差异无显著性意义(P > 0.05),转染组不同时间点之间VEGF165蛋白含量差异均有显著性意义(P< 0.05),hVEGF165基因转染的骨髓间充质干细胞能成功分泌VEGF165蛋白。提示采用基因转染技术可将hVEGF165基因转染到骨髓间充质干细胞中并可有效表达具有生物活性的VEGF165。  相似文献   

11.
In this study, the feasibility of a newly developed interstitial cooling device inserted into the neck muscle and placed on the surface of the common carotid artery is evaluated. A combination of vascular model and continuum model is developed to simulate the temperature fields in both the neck and brain regions. Parametric studies are conducted to test the sensitivity of various factors on the temperature distribution. It has been shown that the length of the device, temperature of the device, and the tissue gap between the device and the blood vessel are the dominant factors that determine the effectiveness of this cooling approach. Under the current design parameters, the device is capable of inducing a temperature drop of 2.8°C along the common carotid artery and it results in a total of 90 W of heat carried away from the arterial blood. Although the degree of the cooling in the arterial blood is inversely proportional to the blood flow rate of the arteries, the total heat loss from the arterial blood does not vary significantly if the blood flow rate changes during the cooling. After the cold arterial blood is supplied to the brain hemisphere, temperature reduction in the brain tissue is almost uniform and up to 3.1°C temperature drop is achieved within 1 hour. In addition to the possible benefits of brain hypothermia for stroke or head injury patients, the device has the potential to control fever as well as to improve patients’ outcome during open neck and head surgery.  相似文献   

12.
The author offers a brief introduction to the theories of Armando Ferrari, highlighting his emphasis on the body, not only as mind's first object, but on the object out of which mind originates. He notes that this notion is the heir to Freud's preoccupation with finding the organic foundation of the mind in the body in which it is rooted, and in the idea of the drives as the expression of emergent psychic functions from the body, whereas instinct is the psychical representative of the stimulus originating from within the organism. Drives are not so much corporeal or psychic as defining the connection between the two realms. He suggests that this distinction became blurred with the tendentious translation of Trieb as ‘instinct’ and, later, as ‘emotion’, with the connotations of mental phenomena detached from the physical; while furthermore, the object relational stance, particularly as promulgated by Klein, suggested that such instincts could only be related to by the infant and become mind having been projected into the breast and then reintrojected. The infant's relationship with his body is thus mediated by the breast in Klein's model, rather than immediate and direct. Thus, whereas Freud always linked the psychosexual development of the infant directly with the emergence of physical desire arising from the erogenous zones, Klein linked the first fantasies (innate unconscious phantasy) with the infant's relationship with the maternal breast which now becomes the infant's first object, and emphasis is placed upon this object rather than on the subject of perception. Therapeutically, this necessitates that it also be placed on the transference. Bion moved away from this model with his emphasis on the proto‐mental in which physical and mental remain undifferentiated, so that distress from it as a source can be expressed in either; and in his idea of beta elements (sensational and affective) which are chronologically anterior to alpha elements and which can be employed for expression where alpha elements do not exist. The author concludes with a section on Ferrari whose bipartite model of mind arising out of body (as opposed to Winnicott's tripartite model which he discusses earlier in the paper) might be expressed in Bion's terms as one in which beta elements contain within themselves thecapacity to become alpha elements, while alpha function arise out of beta. Bion's shift from the object relations model to one based on the relation between sensation and affect on the one hand and mental function on the other entailed a shift away from insistent transference interpretation in favour of confronting the patient with his bodily self, a shift which Ferrari embraced and developed.  相似文献   

13.
目的 研究不同程度单侧侧脑室扩张对脑实质体积的影响并探讨其对胎儿诊疗的临床价值。方法 收集经超声证实的孤立性单侧侧脑室扩张的胎儿,行胎儿颅脑1.5T MR扫描。测量扩张侧及正常侧的侧脑室宽度、相邻外侧脑实质厚度、侧脑室体积、大脑半球体积,并计算脑实质体积。每隔1月随访侧脑室宽度随孕周的变化情况。结果 最终纳入研究的23~31孕周的孤立性单侧侧脑室扩张胎儿共49例,按扩张程度分为3组:轻度扩张组12例、中度扩张组27例、重度扩张组10例。对比研究结果如下:(1) 3组病例的扩张侧与正常侧比较,扩张侧邻近脑实质厚度减小,脑实质体积未见明显差异;(2) 3组病例间的扩张侧侧脑室宽度、体积及大脑半球体积均存在差异(P<0.05),扩张侧脑实质厚度及体积未见明显差异;(3)随访发现轻中度扩张组侧脑室宽度逐渐减小者占76%,重度扩张组流产率达80%。结论孤立性单侧侧脑室扩张对脑实质的体积没有影响,轻中度扩张胎儿预后好,这为侧脑室扩张胎儿的评估、预后和干预提供了重要影像学信息。  相似文献   

14.
目的 揭示踝及足背皮神经的整体分布模式,为皮瓣移植感觉重建提供形态学指导。 方法 成年尸体24具,紧贴肌表面摘取含皮下脂肪的踝及足背皮肤,用改良的Sihler’s染色法显示并观察皮神经整体分布模式。 结果 在Sihler’s染色的标本中,肉眼可见隐神经支配踝前区(40.01±7.6)%、踝后区(30±6.7)%、以及部分足背内侧缘。腓浅神经支配踝前区(60.03±6.8)%,其足背内侧皮神经支配足背内侧区、第1、2趾背及第3趾背内侧半;95.83%的足背中间皮神经分布到第3趾背外侧半、第4、5趾背。腓肠神经支配踝后区(70±5.3)%,其足背外侧皮神经支配足背外侧缘皮肤。腓深神经分布到第1、2趾背相对面。初级神经支密度以踝前区最高,次级及以下神经支密度和总的神经支密度均以足背内侧区最高。 结论 在踝或足背的皮瓣移植中,建议把踝前区或足背内侧区设计为利于感觉重建的首选供区或感觉需求较高的受区。  相似文献   

15.
AIMS: Sixty new cases of human dirofilariasis due to Dirofilaria repens, occurring in Italy between 1990 and 1999, are presented. This is the most extensive case study of this zoonosis reported worldwide by a single study group. The aim is to utilize this large experience to characterize the different histopathological findings in the parasitic lesions in man. METHODS AND RESULTS: Diagnosis was performed on histological sections of the nematode enclosed in the nodules excised at biopsy or surgery. The nematode was located in the subcutaneous tissue (49 cases), the epididymis (two cases), the spermatic cord (two cases), the lung (two cases), the breast (two cases), the omentum (two cases) and under the conjunctival tissue (one case). The majority of cases (46) were from Piedmont; the remainder were from Emilia-Romagna, Sardinia, Sicily, Tuscany, Apulia and Lombardy. The histopathological features of the lesions are described and the clinical and epidemiological aspects of the zoonosis are discussed. The prevalence in Italy in general and in the area of Piedmont in particular, comprising the provinces of Alessandria, Asti, Novara and Vercelli, which is one of the most severely affected areas of the world, is emphasized. The evident increase in the number of cases in the last few years is a clear indication that it is an emergent zoonosis. CONCLUSIONS: We recommend that each and every case observed be recorded, to enable the true extent of human dirofilariasis in Italy to be assessed, and that a reference centre be set up in the area to collate the data. The importance of the histopathologist's role in the diagnosis is stressed.  相似文献   

16.
17.
中枢神经系损伤后不同时期星形胶质细胞的变化   总被引:5,自引:0,他引:5  
将神经毒6-羟多巴胺注入大鼠一侧中脑腹侧被盖区,用胶质原纤维酸性蛋白抗体对损伤鼠中脑切片进行免疫组织化学ABC法检测,观察星形胶质细胞在受损伤1d至30d的不同时期的变化,术后1 ̄3d,针道所经处见到GFAP阳性反应的细胞纤维,其胞体增大,纤维短粗。术后1周,针道周围反应性胶质细胞增多,有些反应性胶质细胞发出长的突起横向延伸垂直于针道,损害区附近血管增生,紧贴血管外周的胶质细胞也出现反应性变化。术  相似文献   

18.
The objective of this study is to investigate the influence of gelatin complexation on the biological activity of basic fibroblast growth factor (bFGF) and its resistance to trypsin digestion. When bFGF was mixed at 37°C with acidic gelatin with an isoelectric point(IEP)of 5.0, the activity to promote in vitro proliferation of BHK cells became lower compared with that of free bFGF,in contrast to mixing with the basic gelatin with an IEP of 9.0. A maximum reduction in the bFGF activity was observed for the bFGF-gelatin complex prepared at a mixing molar ratio of 1/1. The bFGF activity of cell proliferation reduced at the initial period after mixing with the acidic gelatin at 37°C, followed by no substantial change. Complexation with the acidic gelatin at 4°C had no influence on the bFGF activity, irrespective of the bFGF/gelatin ratio and complexation time. The biological activity of bFGF was reduced by the trypsin treatment, but the reduced extent was suppressed through gelatin complexation at 37°C. In an electrophoresis study, the protective effect of gelatin complexation on the trypsin digestion was also confirmed in terms of the molecular weight loss. It is possible that the complexing gelatin covers bFGF molecules, resulting in suppression of their interaction with the cell surface receptor as well as protection from their enzymatic attack.  相似文献   

19.
It was shown by the indirect immunofluorescence method that the lower content of muscle antigens in the myoid cells of the embryonic than in the adult human thymus is due to the higher secretory activity of these cells in the early stages of embryogenesis. Because of the increased secretory activity of the myoid cells the internal medium of the embryonic thymus contains more common antigens with muscle tissue than the adult human thymus. The fact that the functional activity of the myoid cells correlates during individual development with the rate of formation of lymphoid tissue confirms the view that heteroorganic antigens provide the lymphocytes of the thymus with information of the structure of autoantigens necessary for the formation of natural immunologic tolerance to them.Laboratory of Streptococcal Infections, N. F. Gamaleya Institute of Epidemiology and Microbiology, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR O. V. Baroyan.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 11, pp. 616–620, November, 1978.  相似文献   

20.
目的 观察腰椎弓根延长术截骨部位与其毗邻神经根的解剖关系,为腰椎弓根延长术离断椎弓根提供解剖数据。  方法 16例成人防腐脊柱标本, 自T12~S1去除软组织、棘突、椎板、关节突关节、横突, 充分暴露硬膜囊、神经根和腰椎弓根, 精细磨削椎弓根至椎弓根-椎体连接处,测量该部位椎弓根上缘至上位神经根下缘的间距(PSRD),椎弓根下缘至下位神经根上缘的间距(PIRD),椎弓根内缘至硬膜囊外缘或内侧神经根外缘的间距(PMRD),椎弓根外缘至外位神经根内缘的间距(PLRD),所有解剖参数都做双侧测量。  结果 腰椎弓根至上、下、内、外神经根的间距范围分别是4.9~8.6 mm,1.0~2.5 mm,0~1.6 mm,0.7~11.5 mm,左、右两侧数据无显著性差异(P>0.05),男、女之间数据无显著性差异(P>0.05)。  结论 腰椎弓根截骨延长时,截骨部位的内缘和下缘毗邻的神经根相对于上缘和外缘损伤可能性大,透视下对椎弓根内缘和下缘截骨时要十分小心。  相似文献   

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