Molecular Tissue Engineering: Applications for Modulation of Mesenchymal Stem Cells Proliferation by Transforming Growth Factor β_1 Gene Transfer

The effect of transforming growth factor β 1 (TGF β 1 ) gene transfection on the proliferation of bone marrow derived mesenchymal stem cells (MSC S ) and the mechanism was investigated to provide basis for accelerating articular cartilage repairing using molecular tissue engineering technology. TGF β 1 gene at different doses was transduced into the rat bone marrow derived MSCs to examine the effects of TGF β 1 gene transfection on MSCs DNA synthesis, cell cycle kinetics and the expression of proliferating cell nuclear antigen (PCNA). The results showed that 3 μl lipofectamine mediated 1 μg TGF β 1 gene transfection could effectively promote the proliferation of MSCs best; Under this condition (DNA/Lipofectamine=1μg/3μl), flow cytometry and immunohistochemical analyses revealed a significant increase in the 3 H incorporation, DNA content in S phase and the expression of PCNA. Transfection of gene encoding TGF β 1 could induce the cells at G0/G1 phase to S1 phase, modulate the replication of DNA through the enhancement of the PCNA expression, increase the content of DNA at S1 phase and promote the proliferation of MSCs. This new molecular tissue engineering approach could be of potential benefit to enhance the repair of damaged articular cartilage, especially those caused by degenerative joint diseases.

Successful reconstruction of an ankle defect with free tissue transfer in a hemophilia A patient with repetitive hemoarthrosis:A case report

BACKGROUND Hemophilia, an uncommon yet consequential hereditary bleeding disorder, manifests as two clinically indistinguishable forms that hinder the normal functioning of the coagulation cascade. This impairment renders individuals more susceptible to excessive bleeding during significant surgical interventions. Moreover, individuals with severe hemophilia frequently encounter recurring hemarthrosis, resulting in progressive joint destruction and, subsequently, the need for hip and knee replacement surgeries.CASE SUMMARY The patient was a 53-year-old man with hemophilia A as the underlying disease and had self-injected factor Ⅷ twice weekly for several decades. He had undergone ankle fusion surgery for recurrent hemarthrosis at the Department of Orthopedic Surgery 1 mo prior and was referred to our department because of skin necrosis after a hematoma at the surgical site. An anterolateral thigh perforator free flap was created after three cycles of factor Ⅷ administration in addition to the concomitant administration of tranexamic acid(TXA)(Transamin 250 mg cap, 1 cap tid, q8h). After the operation, from postoperative days(PODs) 1-5, the factor Ⅷ dose and interval were maintained, and q12h administration was tapered to q24h administration after POD 6. Because the patient’s flap was stable 12 d after the operation, factor Ⅷ administration was tapered to twice a week. At 6 mo follow-up, the patient recovered well without any complications.CONCLUSION To the best of our knowledge, there are very few reports of successful free flaps in patients with hemophilia, and none have been reported in patients with hemophilia A. Moreover, there are several reports on the efficacy of TXA in free flaps in general patients;however, there are no case reports of combining factor Ⅷ and TXA in patients with hemophilia. Therefore, we report this case to contribute to future academic research.

Expression of Transforming Growth Factor β_(1) in Mesenchymal Stem Cells: Potential Utility in Molecular Tissue Engineering for Osteochondral Repair

The feasibility of using gene therapy to treat full-thickness articular cartilage defects was investigated with respect to the transfection and expression of exogenous transforming growth factor(TGF)-β_(1)genes in bone marrow-derived mesenchymal stem cells(MSCs)in vitro.The full-length rat TGF-β_(1)cDNA was transfected to MSCs mediated by lipofectamine and then selected with G418,a synthetic neomycin analog.The transient and stable expression of TGF-β_(1)by MSCs was detected by using immunohistochemical staining.The lipofectamine-mediated gene therapy efficiently transfected MSCs in vitro with the TGF-β_(1)gene causing a marked up-regulation in TGF-β_(1)expression as compared with the vector-transfected control groups,and the increased expression persisted for at least 4 weeks after selected with G418.It was suggested that bone marrow-derived MSCs were susceptible to in vitro lipofectamine mediated TGF-β_(1)gene transfer and that transgene expression persisted for at least 4 weeks.Having successfully combined the existing techniques of tissue engineering with the novel possibilities offered by modern gene transfer technology,an innovative concept,i.e.molecular tissue engineering,are put forward for the first time.As a new branch of tissue engineering,it represents both a new area and an important trend in research.Using this technique,we have a new powerful tool with which:(1)to modify the functional biology of articular tissue repair along defined pathways of growth and differentiation and(2)to affect a better repair of full-thickness articular cartilage defects that occur as a result of injury and osteoarthritis.

Effect of bio-tissue deformation behavior due to intratumoral injection on magnetic hyperthermia

Thermal damage of malignant tissue is generally determined not only by the characteristics of bio-tissues and nanoparticles but also the nanofluid concentration distributions due to different injection methods during magnetic hyperthermia.The latter has more advantages in improving the therapeutic effect with respect to the former since it is a determining factor for the uniformity of nanofluid concentration distribution inside the tumor region.This study investigates the effect of bio-tissue deformation due to intratumoral injection on the thermal damage behavior and treatment temperature distribution during magnetic hyperthermia,in which both the bio-tissue deformation due to nanofluid injection and the mass diffusion after injection behavior are taken into consideration.The nanofluid flow behavior is illustrated by two different theoretical models in this study,which are Navier–Stokes equation inside syringe needle and modified Darcy’s law inside bio-tissue.The diffusion behavior after nanofluid injection is expressed by a modified convection–diffusion equation.A proposed three-dimensional liver model based on the angiographic data is set to be the research object in this study,in which all bio-tissues are assumed to be deformable porous media.Simulation results demonstrate that the injection point for syringe needle can generally achieve the maximum value in the tissue pressure,deformation degree,and interstitial flow velocity during the injection process,all of which then drop sharply with the distance away from the injection center.In addition to the bio-tissue deformation due to injection behavior,the treatment temperature is also highly relevant to determine both the diffusion duration and blood perfusion rate due to the thermal damage during the therapy.

Biothermomechanical behavior of skin tissue

Advances in laser, microwave and similar technologies have led to recent developments of thermal treatments involving skin tissue. The effectiveness of these treatments is governed by the coupled thermal, mechanical, biological and neural responses of the affected tissue： a favorable interaction results in a procedure with relatively little pain and no lasting side effects. Currently, even though each behavioral facet is to a certain extent established and understood, none exists to date in the interdisciplinary area. A highly interdisciplinary approach is required for studying the biothermomechanical behavior of skin, involving bioheat transfer, biomechanics and physiology. A comprehensive literature review pertinent to the subject is presented in this paper, covering four subject areas： （a） skin structure, （b） skin bioheat transfer and thermal damage, （c） skin biomechanics, and （d） skin biothermomechanics. The major problems, issues, and topics for further studies are also outlined. This review finds that significant advances in each of these aspects have been achieved in recent years. Although focus is placed upon the biothermomechanical behavior of skin tissue, the fundamental concepts and methodologies reviewed in this paper may also be applicable for studying other soft tissues.

Near-infrared laser irradiation of a multilayer agar-gel tissue phantom to induce thermal effect of traditional moxibustion

Traditional moxibustion therapy can stimulate heat and blood-vessel expansion and advance blood circulation.In the present study,a novel noncontact-type thermal therapeutic system was developed using a near-infrared laser diode.The device allows direct interaction of infrared laser light with the skin,thereby facilitating a controlled temperature distribution on the skin and the deep tissues below the skin.While using a tissue-mimicking phantom as a substitute for real skin,the most important optical and thermal parameters are the absorption/attenuation coefficient,thermal conductivity,and specic heat.We found that these parameters can be manipulated by varying the agar-gel concentration.Hence,a multilayer tissue-mimicking phantom was fabricated using different agar-gel concentrations.Thermal imaging and thermocouples were used to measure the temperature distribution inside the phantom during laser irradiation.The temperature increased with the increase in the agar-gel concentration and reached a maximum value under the tissue phantom surface.To induce a similar thermal effect of moxibustion therapy,controlled laser-irradiation parameters such as output power,wavelength and pulse width were obtained from further analysis of the temperature distribution.From the known optothermal properties of the patient's skin,the temperature distribution inside the tissue was manipulated by optimizing the laser parameters.This study can contribute to patient-specic thermal therapy in clinics.

Heat transport properties within living biological tissues with temperature-dependent thermal properties

Understanding of the heat transport within living biological tissues is crucial to effective heat treatments. The heat transport properties of living biological tissues with temperature-dependent properties are explored in this paper. Taking into account of variable physical properties, the governing equation of temperature is first derived in the context of the dualphase-lags model(DPL). An effective method, according to the Laplace transform and a linearization technique, is then employed to solve this nonlinear governing equation. The temperature distribution of a biological tissue exposed to a pulsed heat flux on its exterior boundary, which frequently happens in various heat treatments, is predicted and analyzed. The results state that a lower temperature can be predicted when temperature dependence is considered in the heating process.The contributions of key thermal parameters are different and dependent on the ratio of phase lag and the amplitude of the exterior pulsed heat flux.

An electroencephalography-based human-machine interface combined with contralateral C7 transfer in the treatment of brachial plexus injury

Transferring the contralateral C7 nerve root to the median or radial nerve has become an important means of repairing brachial plexus nerve injury.However,outcomes have been disappointing.Electroencephalography(EEG)-based human-machine interfaces have achieved promising results in promoting neurological recovery by controlling a distal exoskeleton to perform functional limb exercises early after nerve injury,which maintains target muscle activity and promotes the neurological rehabilitation effect.This review summarizes the progress of research in EEG-based human-machine interface combined with contralateral C7 transfer repair of brachial plexus nerve injury.Nerve transfer may result in loss of nerve function in the donor area,so only nerves with minimal impact on the donor area,such as the C7 nerve,should be selected as the donor.Single tendon transfer does not fully restore optimal joint function,so multiple functions often need to be reestablished simultaneously.Compared with traditional manual rehabilitation,EEG-based human-machine interfaces have the potential to maximize patient initiative and promote nerve regeneration and cortical remodeling,which facilitates neurological recovery.In the early stages of brachial plexus injury treatment,the use of an EEG-based human-machine interface combined with contralateral C7 transfer can facilitate postoperative neurological recovery by making full use of the brain’s computational capabilities and actively controlling functional exercise with the aid of external machinery.It can also prevent disuse atrophy of muscles and target organs and maintain neuromuscular junction effectiveness.Promoting cortical remodeling is also particularly important for neurological recovery after contralateral C7 transfer.Future studies are needed to investigate the mechanism by which early movement delays neuromuscular junction damage and promotes cortical remodeling.Understanding this mechanism should help guide the development of neurological rehabilitation strategies for patients with brachial plexus injury.

3D氨基质子转移加权成像联合弥散加权成像鉴别良、恶性骨与软组织肿瘤

目的探讨3D氨基质子转移加权成像(APTWI)、弥散加权成像(DWI)及二者联合鉴别良、恶性骨与软组织肿瘤的价值。方法前瞻性对96例骨盆或下肢骨与软组织肿瘤患者采集平扫MRI、APTWI及DWI。分别基于APTWI及DWI获得偏移量为3.5 ppm的非对称性磁化传递率(MTRasym)图及表观弥散系数(ADC)图,测量病灶MTRasym(3.5 ppm)最大值(MTRasym_(max))、均值(MTRasym_(mean))及最小值(MTRasym_(min)),以及ADC最大值(ADC_(max))、均值(ADC_(mean))及最小值(ADC_(min));比较良、恶性肿瘤各参数差异,绘制受试者工作特征曲线,计算曲线下面积(AUC),评估APTWI、DWI及二者联合的鉴别诊断效能。结果96例中,良性41例、恶性55例。恶性肿瘤MTRasym(MTRasym_(max)、MTRasym_(mean)和MTRasym_(min))均明显高于,而ADC(ADC_(max)、ADC_(mean)和ADC_(min))均明显低于良性肿瘤(P均<0.05)。MTRasym_(max)和ADC_(min)鉴别良、恶性肿瘤的AUC分别为0.791和0.873,差异无统计学意义(P=0.122);二者联合的AUC为0.944,高于单一项(P<0.001、P=0.041)。结论APTWI联合DWI鉴别良、恶性骨与软组织肿瘤的效能较高。

脉冲Er:YAG激光辐照多层牙齿组织换热特性分析

目的:研究不同激光输入方式下,牙齿组织内部能量的沉积分布特征,搭建激光输入参数与牙齿组织内部温升的定性关系。方法:基于Pennes生物热传导方程,考虑牙齿组织的层状结构以及激光辐照时牙齿外表面与周围环境的热交换,构建Er:YAG激光辐照牙齿组织的热输运模型。借助有限差分法,对不同激光输入方式下牙齿组织内部温升的时-空分布特征进行了数值模拟和对比分析。结果:激光能量输入方式的改变(脉冲功率、脉宽、脉冲个数、脉冲间隔)对于牙齿组织的温升将产生显著的作用效果,并且其作用效果会随着深度的增加而逐渐衰减;输入总能量一定的前提下,输入方式的作用效果仅集中在照射表面附近,对于组织内部牙髓腔壁面的温升几乎不产生影响。此外,牙齿组织外表面与周围环境的热交换一定程度上抑制牙齿组织的温升并加速其冷却进程。结论:激光输入方式对牙齿组织的温升效果存在重要影响,在其与牙齿组织过程前后需考虑外表面与环境的热交换。

腕横纹桡动脉掌浅支游离皮瓣移植修复手指软组织缺损的疗效观察

目的 探究腕横纹桡动脉掌浅支游离皮瓣移植修复手指软组织缺损的疗效。方法 34例手指软组织缺损患者,以1:1分为观察组和对照组,每组17例。对照组采用局部带蒂转移皮瓣修复治疗,观察组采用腕横纹桡动脉掌浅支游离皮瓣移植治疗。对比两组术后并发症发生情况、手术操作时间、创面愈合时间、术中出血量、皮瓣成活率、手指皮瓣外形恢复美观优良率、血运状态恢复优良率、浅感觉恢复优良率、满意度评分、心理健康评分。结果 观察组术后并发症发生率低于对照组,但对比无差异(P>0.05)。观察组手术操作时间(104.65±10.28)min长于对照组的(92.21±10.18)min,创面愈合时间(19.35±2.22)d短于对照组的(24.18±2.81)d(P<0.05)。两组术中出血量对比无差异(P>0.05)。观察组皮瓣成活率100.00%高于对照组的64.71%(P<0.05)。观察组手指皮瓣外形恢复美观优良率94.12%高于对照组的58.82%(P<0.05)。观察组血运状态恢复优良率94.12%高于对照组的58.82%(P<0.05)。观察组浅感觉恢复优良率94.12%高于对照组的58.82%(P<0.05)。观察组满意度评分(95.32±2.26)分、心理健康评分(23.32±5.26)分均优于对照组的(82.33±2.18)、(49.66±5.20)分(P<0.05)。结论 腕横纹桡动脉掌浅支游离皮瓣移植修复手指软组织缺损的疗效显著,能够取得满意疗效,患者恢复快,且预后显著,建议临床推广。

预扩张头皮瓣在面颈部病损修复中的应用

目的探讨扩张头皮瓣在修复面颈部病损中的作用。方法2012年1月至2023年10月,空军军医大学西京医院整形外科利用预扩张头皮瓣修复面部及颏颈部病损50例。Ⅰ期手术根据病损位置及大小在帽状腱膜下埋置扩张器并规律注水。Ⅱ期手术包括:应用额顶部扩张头皮瓣滑行推进修复额部病损;应用颞顶部扩张头皮瓣,以单侧颞浅动脉为蒂,转移修复颞部及面部病损;应用预扩张顶部头皮瓣,以双侧颞浅动脉为蒂转移修复颏颈部病损。Ⅲ期手术包括皮瓣转移术后3周延迟及断蒂,拆线后2周开始激光脱毛治疗。统计手术并发症,观察手术治疗效果。结果本组共50例,其中额部22例,颞部及面颊部18例,颏颈部10例。Ⅰ期手术血肿1例,感染1例,Ⅱ期皮瓣转移术后血运障碍3例,扩张皮瓣面积5 cm×5 cm~12 cm×30 cm。术后随访2~30个月,转移皮瓣颜色、质地与受区接近,供区无明显瘢痕及畸形。结论预扩张头皮瓣能提供与面颈部皮肤颜色、质地接近的皮肤组织,是修复面部病损的理想方法之一。

人体体表循经红外辐射轨迹形成机理的初步探讨

论述了皮肤的微循环状态和经脉线下深部组织中的传热通道 ,是形成循经红外辐射轨迹 (IRRTM)的两个主要因素 ,尤以后者更为重要 .该通道由深及浅 ,由多种已知的组织组成 ,可能还有一些未知的因素参与 .该处氧分压和组织温度较高 ,微循环旺盛 ,能量代谢活跃 ,为实现物质、能量和信息的转换和传递提供了有利的条件 。

腓骨复合瓣游离移植修复下颌骨缺损

目的 总结应用游离腓骨复合瓣修复下颌骨缺损的经验。方法 1999年 6月～ 2 0 0 0年 11月对5 8例应用腓骨复合瓣游离移植修复下颌骨缺损的病例作回顾性研究 ,其中男 37例 ,女 2 1例。年龄 12～ 6 5岁 ,平均4 0 .9岁。分析下颌骨缺损原因 ,分析腓骨瓣设计、受区血管、组织瓣成活情况及术后并发症的发生情况。结果 5 8例中 5 2例为肿瘤切除术后修复 ,其中 4 3例为一期修复 ,9例为二期修复。采用游离腓骨复合骨瓣的腓骨长度 4～2 1cm ,平均 11.4 cm ;腓骨的截骨为 1～ 4次数 ,平均 2 .1次 ;骨瓣带皮岛最大范围 12 cm× 8cm,最小 3.0 cm×1.5 cm。术后游离腓骨瓣的临床成功率为 96 .6 % (5 6 /5 8) ,失败 2例。受供区并发症主要为血肿、积液、创口感染和腺瘘 ,有 4例为植皮坏死和创口感染 ,发生率为 2 4 .1% ,但不影响效果。结论 游离腓骨瓣在修复下颌骨缺损中具有操作灵活 ,安全可靠 ,制备简便 ,并发症少 。

软组织缺损伴感染创面的修复与功能重建

目的探讨应用皮瓣移植修复软组织缺损伴感染创面的体会。 方法自 1995年 3月以来采用筋膜皮瓣、肌皮瓣、岛状皮瓣移植治疗 5 7例 ,修复四肢软组织创伤 ,覆盖骨、肌腱、神经等深部组织裸露及局部发生感染的创面 ,其中游离皮瓣移植 3 2例 ,筋膜皮瓣 7例 ,岛状皮瓣 18例。 结果 5 4例创面Ⅰ期愈合 ,2例感染创面术后仍有化脓性分泌物 ,经换药创面延迟愈合 ,1例游离皮瓣发生部分坏死 ,清创植皮后愈合。 结论经过 2～ 4年的随访 ,皮瓣移植修复软组织缺损及并发感染的创面 ,功能恢复良好 ,形态满意。

ABC转运蛋白研究的新进展

ABC转运蛋白主要包括P-糖蛋白、多药耐药相关蛋白和乳腺癌耐药蛋白,它们属于同一家族,具有保守的功能结构域和多样化的生物学功能。ABC转运蛋白部分成员的过表达与肿瘤细胞的多药耐药性(MDR)密切相关,是导致化疗失败的主要原因。随着对MDR机制认识的深入,针对多药耐药蛋白的特异结构域已设计出多种形式的MDR逆转药物。近年来发现,ABC转运蛋白广泛存在于多种正常的组织和器官,参与药物和内、外源毒素的吸收、分布和排泄,行使解毒和防御保护的作用。因此,通过转植ABC转运蛋白基因有可能降低经济鱼类、虾等水产品中有毒污染物的积累。

碱性成纤维细胞生长因子基因转染对间充质干细胞生物学行为的调控

为探讨碱性成纤维细胞生长因子 (b FGF)基因转染对间充质干细胞 (MSCs)增殖、定向分化等生物学行为的调控作用 ,本文将体外具有促进 MSCs增殖分化及毛细血管增殖等多重生物学效应的 b FGF基因转入骨组织工程首选种子细胞—— MSCs,通过免疫组化 SABC法检测其瞬时与稳定表达 ,并检测转基因细胞增殖活力及碱性磷酸酶 (AL P)与骨钙素 (OC)合成情况。结果表明 ,b FGF基因能被转入 MSCs并得到稳定表达 ,转基因细胞增殖与OC合成明显增强 ,AL P活性无明显变化。因此 ,转基因 MSCs可使 b FGF持续高效发挥作用 ,克服了使用外源性b FGF半衰期短 ,需反复大剂量给药的缺点 ;b FGF基因转染可促进 MSCs增殖并调控其定向分化 ,使其获得良好的生物学活性 ;从而为把组织工程学与分子生物学有机结合 ,用分子组织工程学技术高质量地修复骨缺损奠定了良好的基础。

离子束辐照结合组织培养在植物诱变中的研究进展

简述了植物组织培养方法与离子束辐射相结合这一新诱变技术的研究进展,从原理、操作步骤、分子机理等诸方面对该方法进行了阐释。该诱变技术具备传统辐射诱变技术所不具备的优势,从而能够为利用无性繁殖技术进行后代繁衍的植物提供新的育种思路。与此同时,使用该方法还能够开展植物组织细胞的传能线密度(Linear energy transfer,LET)生物学效应的研究,从理论上及实践上进一步优化该技术。

组培微环境对葡萄风信子组培苗生长及移栽后生理特性的影响

研究了组培微环境对葡萄风信子组培苗生根阶段的苗生长及移栽后生理特性的影响。结果表明,生根培养时,光强和蔗糖对植株生长均有很大的影响,无论是有糖还是无糖培养,高光强均有利于植株干物质的积累,其中添加3%蔗糖有利于根的生长,并对根系活力和酶的活性有一定的促进作用,无糖处理有利于株高生长。移栽后,微环境调控对移栽成活率有一定的影响,有糖高光照处理的植株移栽后环境适应能力较强,存活率高,生长较好。

植入式医学装置电场耦合式电能传输新方法

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