心脏组织工程瓣脉动流培养系统的设计与构建

自行设计和制造平面和三维立体培养室及贮液室等构件,用医用硅胶管连接;转子泵作为动力源,贮液室通气口供给5%CO2 95%空气,恒温水浴箱保持构件37℃恒温,这样组成了种植细胞与生物瓣支架复合体的脉动培养系统,并进行生物力学和生物相容性测试,为心脏组织工程瓣的体外构建提供研究器材。结果显示,该装置密闭性能好,内环境能保持37±1℃、CO2浓度5%±1%、pH值6.8～7.5;流量在0.125～6.0L/min的范围内任意调节;同种瓣膜上的内皮细胞经2周培养后扩增约10倍;瓣膜支架的细菌和霉菌培养均为阴性,说明我们构建的脉动流培养系统能有效地模拟体内脉动流场实现种植细胞在体外的增殖、重塑,为心脏组织工程瓣的体外构建提供了一种新的实验方法。     

Postmortem Diagnosis of Acute Megakaryocytic Leukemia Usefulness of lmmunohistochemistry and Tissue Hemogram

An autopsy case of acute megakaryocytic leukemia (AMKL) is presented. The bone marrow was hypercellular with proliferation of three lineages, especially megakaryocytes. Immunohistochemical examination revealed many platelet glycoprotein IIb/IIIa (GP IIb/IIIa)- positive blast cells in bone marrow. The proportion of the blasts was 26.4% by tissue hemogram. GP IIb/IIIa-positive blasts and megakaryoblasts were deposited massively in lymph nodes. lmmunohistochemistry against GP IIb/IIIa and tissue hemograms by paraffin section are needed to diagnose AMKL by postmortem examination, since the identification of ultra-structural platelet peroxidase in autopsy materials is difficult.     

新型可降解聚合物聚乙二醇对苯二甲酸酯/聚对苯二甲酸丁二醇酯的细胞相容性研究

目的：研究新型可降解聚合物聚乙二醇对苯二甲酸酯／聚对苯二甲酸丁二醇酯(PEGT／PBT)的人脐静脉内皮细胞(HUVEC)相容性，对其在组织工程血管中的应用进行探讨。方法：对PEGT／PBT进行细胞毒性评价。观察并检测HUVEC在PEGB／PBT、Ⅰ型胶原改性(Col-)的PEGT／PBT、纤维连接蛋白改性(Fn-)的PEGT／PBT上的粘附和增殖，对细胞在粘附过程中的粘着斑蛋白进行免疫荧光染色观察。结果：PEGT／PBT细胞毒性不大于1级，能支持脐静脉内皮细胞的粘附和增殖。纤维连接蛋白和Ⅰ型胶原处理可促进HLIVEC在PEGT／PBT膜上的增殖，而且纤维连接蛋白可增加HUVEC在PEGT／PBT上20min、2h的粘附率，并促进细胞形成局部粘附结构。结论：新型可降解聚合物PEGT／PBT具有良好的血管细胞相容性，对其在组织工程血管中的应用值得进一步开发研究。     

Immunity to type IX collagen in rodents: a study of type IX collagen for autoimmune and arthritogenic activities

Type IX collagen (CIX), a cartilage-specific glycoprotein, constitutes ≤ 10% of cartilage collagen. To ascertain whether CIX can induce arthritis as shown for type II and XI collagen (CII and CXI), outbred rats were sensitized with bovine, chick and human CIX; inbred rats, mice, and guinea pigs were sensitized with bovine CIX. Mice and guinea pigs proved resistant to arthritis, as did rats sensitized with CIX/Freund's incomplete adjuvant (FIA). Arthritis was seen in rats when 100 μg of Mycobacterium tuberculosis (Mtb) were added to FIA, but seldom with smaller doses of Mtb, suggesting the arthritis was adjuvant-induced. High levels of antibodies to rat CIX, containing complement-fixing subclasses, were detected in rat sera in addition to DTH and lymphocyte proliferation responses to rat CIX. Given the potential for CIX-induced disease, CIX-sensitized rats were injected intraperitoneally with lipopolysaccharide (LPS) to stimulate proinflammatory cytokine release, and intra-articularly with rat CIX to stimulate arthritis. LPS stimulation was ineffective; however, intra-articularly injected CIX produced transient synovitis. When rats with stable adjuvant arthritis were sensitized with CIX/FIA, significant increases in paw volume were measured compared with controls given CI/FIA. Immunohistochemical studies of actively and passively sensitized rats revealed deposits of CIX antibody, but not C3, at the joint margins where proteoglycan staining was weak. Together, these findings suggest that autoimmunity to CIX, in contrast to CII and CXI, is not directly pathogenic but may contribute to joint injury provided arthritis is initiated by an independent disease process.     

Minimally immunogenic decellularized porcine valve provides in situ recellularization as a stentless bioprosthetic valve

Currently used bioprosthetic valves have several limitations such as calcification and functional deterioration, and revitalization through cellular ingrowth is impossible. To overcome these obstacles, we have developed a minimally immunogenic tissue-engineered valve that consists of an unfixed, decellularized porcine valve scaffold capable of being spontaneously revitalized in vivo after implantation. Porcine aortic root tissue was decellularized using detergents such as sodium lauryl sulfate and Triton X-100. The porcine valve was treated very gently and plenty of time was allowed for constituents to diffuse in and out of the matrix. In a preliminary study, a piece of decellularized porcine valve tissue was implanted into the rat subdermal space for 14 and 60 days and the structural integrity and calcification were evaluated. As an in vivo valve replacement model, the decellularized porcine valve was implanted in the pulmonary valve position in dogs and functional and histological evaluation was performed after 1, 2, and 6 months. Histological examination showed that the newly developed detergent treatment effectively removed cellular debris from the porcine aortic tissue. Decellularized porcine valve tissue implanted subdermally in rats showed minimal inflammatory cell infiltration and calcification. In the valve replacement model, spontaneous reendothelialization and repopulation of the medial cells were observed within 2 months, and good valve function without regurgitation was observed by echocardiography up to 6 months. The minimally immunogenic decellularized porcine valve proved effective in mitigating postimplant calcification and provided a suitable matrix for revitalizing prostheses through in situ recellularization, cellular ingrowth, and tissue remodeling.     

Fetal and postnatal development of the patella, patellar tendon and suprapatella in the rabbit; changes in the distribution of the fibrillar collagens

The development of the patella, its associated tendons, and suprapatella of the rabbit knee joint is described from the 17 d fetus to the mature adult. The patellar tendon (ligament) with the patella on its posterior surface is seen in the 17 d fetus and is fully developed by 1 postnatal wk. It is composed of bundles of types I and V collagens separated by endotenons of types III and V collagens. Anteriorly there is an epitenon of types III and V collagens while synovium and a fat pad cover its posterior surface. In the 25 d fetus, the patella is cartilaginous and is separated from the femoral condyles. The cartilage contains type II collagen, but types I, III and V collagens are found along the articular surface. Ossification starts 1 postnatal wk and at 6 wk only the articular cartilage remains. In addition to type II, types III and V collagens are located around the chondrocyte lacunae. The long anterior junction between the patella and its tendon is fibrocartilaginous at 1 wk, but as ossification proceeds this is replaced by bone. Types I and V collagens are found in this region. The suprapatella on the posterior surface of the quadriceps tendon is first seen 1 wk postnatally as an area of irregularly organised fibres and chondrocyte-like cells. Types I, II, III and V collagens are present from 3 wk onwards. It is compared with the fibrocartilage of other tendons that are under compression. The arrangement of the collagens in the patellar tendon is discussed in relation to its use as a replacement for injured anterior cruciate ligaments. It is suggested that the structural differences between the patellar tendon and anterior cruciate ligament preclude the translocated tendon acquiring mechanical strength similar to that of a normal cruciate ligament. The designation 'patellar ligament' as opposed to 'patellar tendon' is questioned. It is argued that the term patellar tendon reflects its structure more accurately than patellar ligament.     

胸腹水组织因子及组织因子途径抑制物的检测及其意义

目的研究三组疾病胸腹水组织因子(Tissue factor,TF)及组织因子途径抑制物(Tissue factor pathway inhibitor,TFPI)的表达及其鉴别诊断意义。方法TF和TFPI采用ELISA法测定抗原表达。结果胸腹水TF水平和TFPI水平,恶性肿瘤组(570.04±627.53)ng/L,(28.60±15.57)μg/L和结核病组(283.82±143.16)ng/L,(31.16±12.26)μg/L明显高于肝硬化组(60.83±66.87)ng/L,(7.84±5.45)μg/L,P<0.01。TF/TFPI比值则为恶性肿瘤组(32.17±44.19)明显高于结核病组(13.55±13.15)和肝硬化组(11.22±9.05,P<0.05)。在恶性肿瘤组中,胸腹水癌细胞阳性组的TF表达(1106.92±1244.28)ng/L高于阴性组(331.08±295.84)ng/L,P<0.05。而阳性组的TFPI水平(27.35±17.75)μg/L与阴性组(30.34±13.20)μg/L无明显差异(P>0.05)。TF/TFPI比值则为阳性组(59.59±65.10)明显高于阴性组(11.54±8.37,P<0.01)。结论检测胸腹水TF和TFPI并分析TF/TFPI比值可以作为临床实验室有鉴别诊断意义的辅助指标,同时还可了解疾病的某些病理机制,尤其是肿瘤的某些生物学行为。     

正常国人腰间盘纤维软骨粘弹性实验研究

研究了正常国人急性外伤致死的成人新鲜尸体10个腰间盘L3-4、14-5纤维软骨的力学性质。以一维拉伸的方法得出了L3-4、L4-5腰间盘纤维软骨的破坏载荷、伸长比、Lagrange张应力、Lagrange张应变等数据。以多项式，用回归分析方法得出椎间盘L3-4、L4-5纤维软骨的应力-应变关系表达式及应力-应变曲线。还对椎间盘L3-4、L4-5纤维软骨进行拉伸应力松弛、蠕变实验。得出了椎间盘L3-4、L4-5纤维软骨的归一化应力松弛函数、蠕变函数G(t)、J(t)表达式。以冯元桢教授的软组织大变形准线性理论，构建了L3-4、L4-5椎间盘纤维软骨的松弛函数K(λ，t)=G(t)T^(e)(λ)的表达式，对实验结果进行分析讨论。     

工程化肌腱修复肌腱缺损后力学特性的组织学基础

探讨组织工程化肌腱修复肌腱缺损后体内愈合过程中力学特性的组织学基础。取罗曼鸡肌腱细胞 ,经体外培养、扩增 ,与可降解生物材料聚羟基乙酸筛网构建工程化肌腱 ;将其植入修复 2 0只罗曼鸡第二趾深屈肌腱0 .5～ 0 .8cm缺损。术后第 2、4、6、8周取材 ,对标本进行大体、组织学及生物力学测定。植入 2、4、6、8周 ,新生肌腱在大体形态、细胞及胶原纤维排列方式上与正常肌腱相似 ,但新生肌腱的胶原纤维束并未形成较多的沿肌腱长度方向的致密结构 (“塑形”) ,导致其最大张力增加缓慢 ,到 8周时为 15 .4 0± 10 .6 3N,仅达正常肌腱的 2 3 ;8周时最大张应变为 2 2 .4 9± 10 .2 1 ,比正常肌腱大 10。结果表明 ,单纯聚羟基乙酸作支架 ,材料降解过快 ,新生肌腱失去了正常的力学刺激 ,“塑形”能力差 ,其生物力学强度低。提示 ,保持新生肌腱形成过程中正常的力学刺激对新生肌腱的“塑形”可能是至关重要的。