Maturation and development of fetal pig intestinal tissue in immunodeficient mice

Purpose: This study aimed to compare the degree of maturation and development of fetal pig segmental intestinal tissue with that of spheroids created by in-vitro reaggregation of dissociated fetal intestinal cells after transplantation into immunodeficient mice. Methods: Fetal pig small intestines were transplanted as segmental grafts into the omentum and subrenal capsules of immunodeficient mice or enzymatically treated to generate single cells. Spheroids made by in-vitro reaggregation of these cells were transplanted into the subrenal capsules of immunodeficient mice. The segmental grafts and spheroids were harvested four and eight weeks after transplantation, and the structural maturity and in-vivo development of these specimens were histologically evaluated. Results: The spheroids were engrafted and supplied blood vessels from the host mice, but an intestinal layered structure was not clearly observed, and there was almost no change in size. On the other hand, the segmental grafts formed deep crypts in the mucus membrane, the inner circular layer, and outer longitudinal muscles. The crypts of the transplanted grafts harvested at eight weeks were much deeper, and the smooth muscle layer and the enteric nervous system were more mature than those of grafts harvested at the fourth week, although the intestinal peristaltic wave was not observed. Conclusions: Spheroids created from fetal small intestinal cells could not form layered structures or mature sufficiently. Conversely, segmental tissues structurally matured and developed after in-vivo transplantation and are therefore potential grafts for transplantation.

Modified posterior tibialis muscle transfer for treatment of foot drop and varus deformity after common peroneal nerve injury / 中华创伤杂志

Objective:To investigate the early effect of modified posterior tibialis muscle transfer in treating foot drop and varus deformity caused by common peroneal nerve injury.Methods:A retrospective case series study was conducted to analyze the clinical data of 6 patients with foot drop of common peroneal nerve palsy and varus deformity admitted to Beijing Jishuitan Hospital from December 2017 to October 2019, including 4 males and 2 females, aged 33-48 years [(39.5±6.0)years]. The left side was involved in 4 patients and the right side in 2 patients. All patients underwent posterior tibial muscle transfer. The insertion of posterior tibial muscle was reconstructed in the fourth metatarsal with the tendon allograft to correct foot drop and varus deformity. The range of motion of active ankle dorsiflexion and plantar flexion and range of motion of varus and valgus of foot were measured before operation and at the last follow-up. The isokinetic torque peak value of ankle dorsiflexion and plantar flexion at 60°/s angular velocity and peak isokinetic torque of foot varus and valgus at 60°/s angular velocity were measured before operation and at the last follow-up. The postoperative foot imaging evaluation was performed at the last follow-up, including Meary angle, calcaneal projection and diameter of the fourth metatarsal. The American Orthopaedic Foot & Ankle Association (AOFAS) ankle-hindfoot score was used to evaluate the ankle function.Results:All patients were followed up for 6-17 months [10(6, 15)months]. At the last follow-up, the range of motion of dorsiflexion of the ankle [6(0, 10)°] and foot valgus [3(0, 5)°] were significantly improved compared with the preoperative level [-31(-33, -28)°, -10(-12, -8)°] ( P<0.05); the ankle dorsiflexion torque [(7.7±0.8)Nm] and foot valgus torque [(7.2±0.7)Nm] were significantly improved compared with the preoperative level [(0.0±0.0)Nm, (2.1±0.6)Nm]at 60°/s angular velocity ( P<0.01). Imaging examination showed no acquired flat foot deformity and deformation of the fourth metatarsal insertion. The AOFAS ankle-hindfoot score increased from 50-73 points [(61.3±8.4)points] before operation to 75-97 points [(86.8±7.2)points] at the last follow-up ( P<0.01). Conclusion:For foot drop and varus caused by common peroneal nerve injury, modified posterior tibialis muscle transfer can increase the torque of ankle dorsiflexion and valgus, improve the ankle range of motion, and accelerate the ankle function recovery.

Surgical options for aortic root replacement in destructive endocarditis

Abstract Objective: To analyze patients' preoperative characteristics, surgical data, postoperative courses, and short- and long-term outcomes after implantation of different full-root prostheses for destructive aortic valve endocarditis. Methods: Between 1999 and 2018, 80 patients underwent aortic root replacement due to infective endocarditis in our institution. We analyzed the abovementioned data with standard statistical methods. Results: The Freestyle stentless porcine prostheses were implanted in 53 (66.25%) patients, biological valve conduits in 13 (16.25%), aortic root homografts in nine (11.25%), and mechanical valve conduits in five (6.25%). There were no significant preoperative differences between the groups. The incidence of postoperative complications and intensive care unit length of stay did not differ significantly between the groups. The 30-day mortality rate was low among Freestyle patients (n=8, 15.1%) and high in the mechanical conduit cohort (n=3, 60%), though with borderline statistical significance (P=0.055). The best mean survival rates were observed after homograft (13.7 years) and stentless prosthesis (8.1 years) implantation, followed by biological (2.8 years) and mechanical (1.4 years) conduits (P=0.014). The incidence of reoperations was low in the mechanical conduit group (0) and stentless bioroot group (n=1, 1.9%), but two (15.4%) patients with biological conduits and three (33.3%) patients with homografts required reoperations in the investigated follow-up period (P=0.005). Conclusion: In patients with the destructive form of aortic valve endocarditis, homografts and stentless porcine xenografts offer better survival rates than stented valve conduits; however, the reoperation rate among patients who received homograft valves is high.

Feasibility study on the application of the heterogeneous de protein cancellous bone in the treatment of lumber intertransverse process spinal fusion / 中国医师杂志

Objective To investigate application feasibility of the heterogeneous de protein cancellous bone in the treatment of lumber intertransverse process spinal fusion.Methods Thirty 6 ～ 8 month healthy male goats were selected to make intertransverse bone bed,and were randomly divided into groups Ⅰ and Ⅱ,with 15 in each group.Group Ⅰ was the left side implanted the tissue engineering bone (A group),and the right side implanted recombinant human bone morphogenetic protein-2 (rhBMP-2) composite bone (B group);Group Ⅱ was the left implanted autologous bone (C group),and the right side implanted simple heterogeneous de protein cancellous bone (D group).Each group was observed with the Xray,histological morphology,and maximum bending load.Results (1) In groups B and D,postoperative 4-,8-and 12-week X-ray scores were lower than that of group C (P ＜0.05);In group A,postoperative 4-,8-and 12-week X-ray score were (5.30 ± 0.41) points,(8.54 ± 0.89) points,and (11.25 ± 0.91)points,compared to group C,without statistically significant difference (P ＞ 0.05);(2) For groups A,B and D,postoperative 4-and 8-week histological scores were significantly lower than those in group C (P ＜0.05).For group A,postoperative 4-and 8-week histological scores were significantly higher than those of groups B and D (P ＜0.05).The histological scores of groups B and D postoperative 12 weeks were lower than those of group C (P ＜0.05).The histological score of group A postoperative 12 weeks was (11.04 ± 1.52) points,compared to group C without statistically significant difference (P ＞ 0.05);(3) The maximum bending load of groups B and D was lower than that of group C (P ＜ 0.05).The maximum bending load of group A was (60.32 ± 10.10) N,compared to group C without statistically significant difference (P ＞ 0.05).Conclusions The construction of tissue engineered bone by the heterogeneous de protein cancellous bone,its osteogenesis is close to autogenous bone,but simple heterogeneous de protein cancellous bone osteogenesis is poor.

Clinical effect of bioengineered cornea and in vivo confocal microscopy observation after human lamellar keraplasty / 中华实验眼科杂志

Background Xenotransplantation is arousing more attention of researchers because of the lack of corneal donors.Biological corneal scaffolds constructed by porcine corneal acellular stroma appears to have an acceptable biocompatibility.However,its clinical effects and the histomorphological features in the corneal tissue of receipts' are still unclear.Objective This study was to evaluate the viability of bioengineered corneas as a new material of human lamellar keratoplasty and observe the in viva biological features after human keratoplasty under the laser confocal microscope.Methods A prospective serial cases observational study was carried out.Fifteen eyes of 15 patients with infectious keratitis were enrolled in Henan Eye Hospital from February to August 2014 under the approval of Ethic Committee of Henan Eye Hospital and informed consent of each patient, including 4 eyes of fungal keratitis,1 eye of bacterial keratitis, 9 eyes of mixed infectious keratitis and 1 eye of leucoma.Corneal lamellar transplantation was performed on the eyes with the bioengineered corneas as grafts and the follow-up time was one year.The survival of grafts was assessed and scored, and the indices including corneal transparency,neovascularization, graft lysis or inflammatory recurrence and visual acuity (logMAR) were evaluated.The morphology and density of corneal epithelial cells and endothelial cells, corneal stroma and subepithelial neural fibers were examined by laser confocal microscope 3,6,9 and 12 months after surgery.Results Postoperative inflammatory response was seen 3 days and disappeared 7 days after surgery.The grafts were clear 1 month after surgery, and no corneal dissolution was found during the follow-up duration.Glaucoma occurred in 1 eye at 6 months and graft rejection occurred in another eye 12 months after surgery.The logMAR, corneal transparency scores and corneal neovascularization scores improved after surgery in comparison with before surgery,with a significant difference among various time points (x2 =92.63,59.37,10.50 ,all at P＜0.05).Complete epithelization of grafts was seen.Compared with the contralateral eyes,the morphology of epithelial cells was similar and endothelial cells were enlarged in the operated eyes.In addition,no stromal cell structure was seen in the corneal stroma in the operative eyes.Subepithelial nerve fibers appeared in 8 eyes at 6 months, but the fiber density was lower in the operated eyes than that in the contralateral eyes.Significant difference was found in epithelial cell density among different time points (F=1.48, P =0.22).The endothelial cell densities were (2 542 ± 119), (1 895 ± 129), (1 869 ± 135), (1 854 ± 101) and (1 844 ± 103)/mm2 before surgery and 3, 6, 9 and 12 months after surgery, showing significant differences between preoperation and postoperative time points (all at P＜0.05).The subepithelial nerve fibers densities were (1.26± 0.13),(3.62±0.81) and (5.98±0.44) mm/mm2 at 6,9 and 12 months after surgery,with significant differences between adjacent two time points (t'=-8.16 ,-7.24;both at P=0.00).Conclusions Bioengineered corneal grafts survive well in human eye after lamellar transplantation,which can reconstruct ocular surface and improve the visual acuity.Biological cornea can replace human corneal materials.

Research progress of patient-derived xenograft model / 国际外科学杂志

Tumor cell line culture technologies emerged as a strong impetus to the development of tumor biology research.However,cell line tumor model presented limited predictive value and instable properties in the clinical translational research of new cancer therapies.Recently Patient-derived Xenograft Model (PDX) has aroused researcher's attention and been widely applied to new cancer therapy research.This new model could highly retain the stroma heterogeneity、histological characteristics and molecular diversity of the original tumor,and is expected to bring new breakthroughs in individualized treatment of tumor patients.

Thin-thicknessversus blade-thickness micro-skin pulping covered with heterogeneous skin for repair of burn wounds / 中国组织工程研究

BACKGROUND:Autologous micro-skin graft covered with alogeneic skin has become a major means for repair of extremely severe burn wounds. Due to the limitation of the source of alogeneic skin, heterogeneous skin (pigskin) or artificial skin serves as a vector to cover the wound on the clinical use. OBJECTIVE: To observe the curative effect of thin-thickness micro-skin pulping covered with heterogeneous skin for repair of burn wounds in comparison with blade-thickness micro-skin pulping covered with heterogeneous skin. METHODS:A self-control study was performed in 36 patients with severe burns of bilateral limbs. There were 42 pairs of wounds, 32 of which were at joint sites. One or two pairs of III-degree burns treated with escharectomy were selected from each patient for self-control comparison. Covered with heterogeneous skin, thin-thickness micro-skin pulping and blade-thickness micro-skin pulping were used in the trial and control groups, respectively. The expansion ratio was controled at 1:8-1:12 in al patients. Wound healing time, degree of scar hyperplasia within 6 months to 2 years after transplantation, and ratio of reconstruction surgery at joint sites were observed and compared. The removed scars by surgery were analyzed based on the total score of the Vancouver Scar Scale. RESULTS AND CONCLUSION: The average wound healing time was (44.7±1.24) days in the trial group and (49.6±1.41) days in the control group, and there was a significant difference between the two groups (P 0.05). The reconstructive surgery ratio of the trial group was 38%, significantly lower than that of the control group (59.38%;P < 0.01). The total score on the Vancouver Scar Scale was less in the trial group than the control group (P < 0.05). These findings suggest that the thin-thickness micro-skin covered with heterogeneous skin is likely to be a better treatment to repair large ful-thickness skin burn by increasing the thickness of micro-skin, and it can obtain better wound healing quality.

Alpha-Gal antigen and immunity risk control of animal-derived medical devices / 中国组织工程研究

BACKGROUND:Medical devices from animals are commonly used in clinical application. Despite their efficiency is widely accepted, their safety, especialy immunity has been concerned. OBJECTIVE:To investigate immunity risk control to medical devices from animals for safety consideration. METHODS:Using “α-Gal antigen, immunity, xenotransplantation” in Chinese and English as the key words, the first author conducted a computer search of Science direct database (www.sciencedirect.com), Wiley-Blackewel database (http://onlinelibrary.wiley.com) and Wanfang database (www.wanfang.com.cn) through screening the titles and abstracts. RESULTS AND CONCLUSION:Increasing evidence shows that, Gal α1-3Gal antigen (α-Gal antigen) is recognized as the major antigen and abundantly expressed on glycoconjugates of non-primate mammals and New World monkeys. In contrast, the α-gal epitope is not expressed on glycoconjugates of humans and Old World monkeys. Instead, they produce a very large amount of natural anti-α-Gal antibody that specificaly binds the α-gal epitope. The binding of human natural anti-α-Gal to α-gal epitopes expressed on non-primate mammal animals was expected to be unique immunological barrier in xenotransplantation. Therefore, it is important to choose raw materials, reduce or eliminate the α-Ggal epitope, establish highα-Ggal epitope detection methods with high sensitivity and good repeatability for achieving a greater safety and efficiency of medical devices from animals.

Xenotransplante de células mesenquimais de tecido adiposo humano em modelo de lesão de raízes ventrais da medula espinal de rato / Xenotransplantation of mesenchymal stem cells from human adipose tissue in a rat model of ventral root lesions of the spinal cord

A avulsão de raízes motoras, na interface do sistema nervoso central e periférico, já bem descrito na literatura, promove uma significativa perda sináptica com degeneração de cerca de 80% dos motoneurônios afetados. Não existem estratégias eficazes que propiciem uma reversão ou amenização deste quadro, mas alguns estudos já mostram que o passo fundamental é preservar os motoneurônios afetados. Pesquisas em diferentes áreas com células-tronco (CT) adultas estão sendo realizadas nos últimos anos e apresentam resultados promissores para a medicina regenerativa. Investigações recentes têm apontado para diferentes fontes de CT em tecidos adultos tais como de medula óssea, de sangue de cordão umbilical, tecido muscular, tecido nervoso, líquido amniótico entre outras. De modo geral, estas células apresentam como características principais a capacidade de proliferação e a diferenciação para outros tipos celulares. Entretanto, os principais problemas para o uso clínico das CT adultas são: i) pequena quantidade de células multipotentes, ii) o controle da diferenciação, iii) insuficiência no número de células viáveis e iiii) difícil obtenção. Como alternativa às dificuldades anteriormente citadas, o tecido adiposo tem sido foco de intensos estudos, pois este tecido possui rica fonte de células pluripotentes, além de apresentarem características positivas como fácil acesso ao tecido adiposo subcutâneo, obtenção em quantidade abundante e processo de isolamento celular relativamente simples. Apesar deste tecido apresentar organização complexa, é na fração celular do estroma vascular que se encontra uma rica população de células pluripotentes. Dados de literatura demonstram que as células mesenquimais derivadas de tecido adiposo (AT-MSC - Células mesenquimais de tecido adiposo), mediante incubação com meios de cultura variados, diferenciam-se em adipócitos, osteócitos, mioblastos, hepatócitos, células vasculares entre outras.

It is well described in the literature that avulsion motor at the interface of the central and peripheral nervous system, promotes a significant loss of synaptic degeneration and 80% of motor neurons death. There is no effective strategies that favor a reversal or mitigation of this framework, but some studies have shown that the key step is to preserve motor neurons affected. Researches in different areas with stem cell (CT) adults are being undertaken in recent years and show promising results for regenerative medicine. Recent investigations have pointed to different sources of CT in adult tissues such as bone marrow, umbilical cord blood, brain, muscle tissue, amniotic fluid, among others. Generally, these cells have as main characteristics capacity for proliferation and differentiation to other cell types. However, the main problems for the clinical use of adult SC are: i) small amount of multipotent cells, ii) differentiation control, iii) low number of viable cells and iiii) difficulty to obtain. As an alternative to the difficulties mentioned above, adipose tissue has been the focus of intense study, because this tissue has a rich source of stem cells, in addition to having positive characteristics such as easy access to subcutaneous adipose tissue, obtained in abundant quantities and isolation process relatively simple. Despite the complex tissue organization, the stromal vascular fraction is rich of pluripotent population cells. Literature data show that stromal cells derived from adipose tissue (AT-MSC-adipose tissue mesenchymal stem cells) can differentiate by incubation with various culture media into adipocytes, osteocytes, myoblasts, hepatocytes, vascular cells, among others. The AT-MSC differentiation into neuronal cells is still subject of discussion and criticism in literature, since no established protocol has induced differentiation into function neuronal cells.

Resposta tecidual ao implante ósseo xenógeno inorgânico variando-se o método de esterilização: avaliação histomorfológica e histomorfométrica / Tissue response to inorganic xenograft implant: histomorphological and histomorphometrical evaluation

Proposição: Este estudo avaliou a resposta tecidual ao implante xenógeno inorgânico de osso bovino, por meio de análise histomorfológica e histomorfométrica, variando-se o método de esterilização. Materiais e Método: Discos de 8 mm costela bovina foram obtidos por processamento específico para remoção de parte orgânica e foram esterilizados por meio de autoclavagem ou radiação gama. Em seguida, 20 coelhos brancos (Nova Zelândia) foram cirurgiados para instalação dos discos na face lateral dos gônios mandibulares, bilateralmente, através de parafuso de fixação de enxertos, originando dois grandes grupos: Grupo EA - implante autoclavado; Grupo EI – implante gama-irradiado. As lâminas foram obtidas nos períodos de 15 e 45 dias pós-operatórios e as imagens teciduais foram analisadas qualitativa e quantitativamente. Resultados: O teste de Kruskal-Wallis foi aplicado e não identificou diferença significativa entre as medidas lineares das interfaces osso/implante (BIC) dos grupos dentro dos mesmos períodos (15 dias: p=0,100; 45 dias: p=0,940). Conclusão: De acordo com a metodologia aplicada, foi possível concluir que o estabelecimento da integração osso/implante cursou com atraso quando o implante foi esterilizado por radiação, porém, com a evolução da reparação, o método de esterilização não ocasionou alterações significativas no período final

Proposition: This study evaluated the tissue response to the implant inorganic xenogenic bovine bone through the histomorphological analysis, varying the method of sterilization. Materials and Methods: Discs of 8 mm bovine rib were obtained by specific processing to remove organics phase and were sterilized by autoclaving or gamma radiation. Then, 20 white rabbits (New Zealand) were operated for discs installation on gonion external side of mandibular, bilaterally, through screw grafts, yielding two large groups: EA - implant autoclaved; EI Group - gamma-irradiated implant. Slides were obtained at 15 and 45 days post-operative tissue and the images were analyzed qualitatively and quantitatively. Results: The Kruskal-Wallis test was used and no difference was found between linear interfaces of the bone / implant (BIC) groups within the same period (15 days: p = 0.100; 45 days: p = 0.940). Conclusion: According to the methodology, it was concluded that the establishment of integration bone / implant occurred later when the implant was sterilized by radiation in initial period, but with the evolution of repair, the method of sterilization did not cause significative changes in the final period

Articular cartilage defect treated with biological osteochondral xenogenic graft transplantation / 中国组织工程研究

BACKGROUND:The methods used to repair articular cartilage defects currently have the cons and pros. Fibrocartilages are commonly used to repair tissues, and the fibrocartilage lacks of the tissue biomechanical properties and chemical properties of normal hyaline cartilage. OBJECTIVE:To investigate the feasibility of biological osteochondral xenogenic graft transplantation to repair articular cartilage defects. METHODS:The normal goats were randomly divided into two groups. The donor pig knee joints were the experimental group. Cylindrical osteochondral with the diameter of 4.5 mm and length of 10 mm were col ected with the Smith&Nephew osteochondral transplantation device, and the patented technology was used for deantigen. The donor goat knee joint osteochondrals were the control group and preserved with cryopreservation. The lesions on femoral trochlea and weight-bearing surface of medial condyle were selected respectively for osteochondral implantation, and the animals were sacrificed at 16 and 32 weeks after operation for the general and pathological section observation. RESULTS AND CONCLUSION:General observation in the experimental showed that the lesions were covered by fibroid tissue;some cartilage of the grafts turned yel ow and there was clear boundary between the surface and the peripheral cartilages;the general and section observation under microscope showed that lesions of the control group were covered by the grafts basical y, and cracks could be seen on the edge of the transplant part. The results show that there is difference between effects of biological osteochondral xenogenic graft transplantation and osteochondral al ograft transplantation for the repairing of articular cartilage defects, and osteochondral al ograft transplantation bas better effect.

Resposta tecidual ao implante ósseo xenógeno inorgânico variando-se o método de esterilização: avaliação histomorfológica e histomorfométrica / Tissue response to inorganic xenograft implant: histomorphological and histomorphometrical evaluation

Proposição: Este estudo avaliou a resposta tecidual ao implante xenógeno inorgânico de osso bovino, por meio de análise histomorfológica e histomorfométrica, variando-se o método de esterilização. Materiais e Método: Discos de 8 mm costela bovina foram obtidos por processamento específico para remoção de parte orgânica e foram esterilizados por meio de autoclavagem ou radiação gama. Em seguida, 20 coelhos brancos (Nova Zelândia) foram cirurgiados para instalação dos discos na face lateral dos gônios mandibulares, bilateralmente, através de parafuso de fixação de enxertos, originando dois grandes grupos: Grupo EA - implante autoclavado; Grupo EI – implante gama-irradiado. As lâminas foram obtidas nos períodos de 15 e 45 dias pós-operatórios e as imagens teciduais foram analisadas qualitativa e quantitativamente. Resultados: O teste de Kruskal-Wallis foi aplicado e não identificou diferença significativa entre as medidas lineares das interfaces osso/implante (BIC) dos grupos dentro dos mesmos períodos (15 dias: p=0,100; 45 dias: p=0,940). Conclusão: De acordo com a metodologia aplicada, foi possível concluir que o estabelecimento da integração osso/implante cursou com atraso quando o implante foi esterilizado por radiação, porém, com a evolução da reparação, o método de esterilização não ocasionou alterações significativas no período final

Proposition: This study evaluated the tissue response to the implant inorganic xenogenic bovine bone through the histomorphological analysis, varying the method of sterilization. Materials and Methods: Discs of 8 mm bovine rib were obtained by specific processing to remove organics phase and were sterilized by autoclaving or gamma radiation. Then, 20 white rabbits (New Zealand) were operated for discs installation on gonion external side of mandibular, bilaterally, through screw grafts, yielding two large groups: EA - implant autoclaved; EI Group - gamma-irradiated implant. Slides were obtained at 15 and 45 days post-operative tissue and the images were analyzed qualitatively and quantitatively. Results: The Kruskal-Wallis test was used and no difference was found between linear interfaces of the bone / implant (BIC) groups within the same period (15 days: p = 0.100; 45 days: p = 0.940). Conclusion: According to the methodology, it was concluded that the establishment of integration bone / implant occurred later when the implant was sterilized by radiation in initial period, but with the evolution of repair, the method of sterilization did not cause significative changes in the final period

O conduto valvulado bovino contegra, um biomaterial para o tratamento cirúrgico de cardiopatias congênitas / The contegra valved bovine conduit: a biomaterial for the surgical treatment of congenital heart defects

O Contegra, um enxerto de veia jugular bovina, tem sido amplamente utilizado como biomaterial de preferência no tratamento cirúrgico das cardiopatias congênitas, especialmente como um conduto para a reconstrução da via de saída ventricular direita. Este artigo tem como objetivo fazer uma revisão abrangente sobre os desfechos clínicos do Contegra. Foram recuperados, coletados e analisados, relatos de Contegra publicados desde 2002. Havia 1.718 Contegra, aplicados em 1.705 pacientes. Os tamanhos dos condutos foram de 8-22 mm. As idades dos pacientes foram de recém-nascidos até 74,5 anos, com prevalência de pacientes pediátricos. O diagnóstico primário foi cardiopatia congênita em todos os casos, sendo os três diagnósticos principais: tetralogia de Fallot, tronco arterioso e atresia pulmonar, que representaram 25,6%, 16,7% e 13,1%, respectivamente. O Contegra foi utilizado como enxerto tubular na posição pulmonar em 1635 (95,9%) pacientes, como remendo monocúspide em 12 (0,7%), como enxerto na posição da valva pulmonar ou monocúspide em 40 (2,3%), e, como conduto artéria pulmonar-veia cava inferior na operação de Fontan, em 18 (1,1%) pacientes, respectivamente. O reimplante de conduto foi realizado em 141 (8,3%) pacientes, 33,8 ± 37 (8,6-106,8) meses após a inserção do conduto inicial. A plástica do conduto foi necessária em seis (0,4%) e a reintervenção em 83 (4,9%) dos pacientes. As indicações do reimplante do conduto incluíram estenose importante da anastomose distal, pseudoaneurisma da anastomose proximal e regurgitação importante do conduto. Quanto ao bom desempenho, disponibilidade e longevidade, o Contegra é um biomaterial adequado para a reconstrução da via de saída ventricular direita e como remendo para reparo de comunicação interventricular, mas não é apto para a operação de Fontan.

Contegra, a bovine jugular vein graft, has been widely used as a preferable biomaterial in the surgical treatment of congenital heart defects, especially as a conduit for the right ventricular outflow tract reconstruction. This article aims to make a comprehensive review on the clinical outcomes of Contegra. Reports of Contegra published since 2002 were comprehensively retrieved, collected and analyzed. There were 1718 Contegra, applied in 1705 patients. The sizes of the conduits were 8-22 mm. The patients aged from newborn to 74.5 years, prevailed by pediatrics. The primary diagnosis was congenital heart defects in all cases, with Tetralogy of Fallot, truncus arteriosus and pulmonary atresia being the first three diagnoses, representing 25.6%, 16.7%, and 13.1%, respectively. Contegra was used as a tube graft in the pulmonary position in 1635 (95.9%) patients, as a monocuspid patch in 12 (0.7%), as a graft in the position of the pulmonary valve or a monocusps in 40 (2.3%), and as an inferior vena cava-pulmonary artery conduit in the Fontan procedure in 18 (1.1%) patients, respectively. Conduit reimplantation was performed in 141 (8.3%) patients 33.8 ± 37 (8.6-106.8) months after the initial conduit insertion. Conduit plasty was necessary in 6 (0.4%), and reintervention in 83 (4.9%) patients. Indications for conduit reimplantation included severe stenosis of the distal anastomosis, pseudoaneurysm of the proximal anastomosis and severe conduit regurgitation. As for the good performance, availability and longevity, Contegra is a biomaterial suitable for the right ventricular outflow tract reconstruction and for patch repair for ventricular septal defect, but not apt for Fontan procedure.

Synergistic suppression of pre-perfusion of donor livers with recipient serum and cobra venom factor treatment on hyperacute rejection following liver xenotransplantation / Supressão sinérgica da rejeição hiperaguda no xenotransplante hepático com uso da pre-perfusão dos fígados doadores tratados com soro do receptor e com fator veneno de cobra

PURPOSE: To investigate synergistic suppression of donor liver pre-perfusion with recipient serum (RS) and cobra venom factor (CVF) treatment on hyperacute rejection (HAR) following liver xenotransplantation. METHODS: Guinea-pigs (GP, n=24) and Sprague-Dawley rats (SD, n=24) were recruited. Before transplantation, serum was collected from SD rats and used for preparation of inactivated complements. GP and SD rats were randomly assigned into four groups (n=6), respectively: RS group, CVF group, RS+CVF group and control group. Orthotopic liver xenotransplantation was performed with modified two-cuff technique. The survival time and liver function of recipients, morphological and pathological changes in rat livers were investigated. RESULTS: There was no piebald like change in the recipient livers in all experiment groups. The survival time of recipients in all experiment groups was longer than that in control group (p<0.05). Moreover, the survival time in the RS+CVF group was markedly longer than that in the RS group (p<0.01) and CVF group (p<0.05). The serum ALT level in all experiment groups were lower than that in the control group (p<0.05). Furthermore, the ALT level in the RS+CVF group was significantly lower than that in the CVF group (p<0.05) and RS group (p<0.01). The histological damages were significantly improved when compared with the control group, and the histological damages in the RS+CVF group were milder than those in the remaining groups (p<0.05) CONCLUSION: Pre-perfusion of donor liver with recipient serum and cobra venom factor treatment can exert synergistic suppressive effects on the hyperacute rejection following liver xenotransplantation.

OBJETIVO: Investigar a supressão sinérgica da pré-perfusão do doador de fígado com soro do receptor (SR) e tratamento com fator veneno de cobra (FVC) na rejeição hiperaguda (RHA) após o xenotransplante de fígado. MÉTODOS: Foram utilizados Cobaias (GP, n=24) e ratos Sprague-Dawley (SD, n=24). Antes do transplante foram coletadas amostras de soro dos ratos SD e usados para a preparação dos complementos inativados. Cobaias GP e ratos SD foram randomicamente distribuídos em quatro grupos (n=6), respectivamente: grupo RS, grupo FVC, grupo SR+FVC e grupo controle. Xenotransplante ortotópico do fígado foi realizado com a técnica de dois cuffs modificados. Foram investigados o de tempo de sobrevida, a função hepática dos receptores e alterações morfopatológicas em fígados de ratos. RESULTADOS: Não houve alteração na coloração do parênquima dos fígados nos receptores. O tempo de sobrevida dos receptores em todos os grupos experimentais foi mais longo do que o grupo controle (p<0,05). Além disso, o tempo de sobrevida do grupo SR+ FVC foi marcadamente maior do que o grupo SR (p<0,01) e o grupo FVC (p<0,05). O nível sérico ALT foi menor em todos os grupos experimentais do que o grupo controle (p<0,05). O nível de ALT no grupo SR+ FVC foi significantemente menor do que no grupo FVC (p<0,05) e o grupo SR (p<0,01). As alterações histológicas foram significantemente melhoradas quando comparado com o grupo controle, e os danos histológicos no grupo SR+ FVC foram mais moderados do que nos grupos restantes (p<0,05). CONCLUSÃO: Pré-perfusão do fígado doador com soro do receptor e fator veneno de cobra pode exercer efeito supressor sinérgico da rejeição hiperaguda após xenotransplante de fígado.

Xenograft Failure of Pulmonary Valved Conduit Cross-linked with Glutaraldehyde or Not Cross-linked in a Pig to Goat Implantation Model

BACKGROUND: Biologic valved grafts are important in cardiac surgery, and although several types of graft are currently available, most commercial xenografts tend to cause early disfiguration due to intimal proliferation and calcification. We studied the graft failure patterns on non-fixed and glutaraldehyde-fixed pulmonary xenograft in vivo animal experiment. MATERIALS AND METHODS: Pulmonary valved conduits were obtained from the right ventricular outflow tract of eleven miniature pigs. The grafts were subjected to 2 different preservation methods; with or without glutaraldehyde fixation: glutaraldehyde fixation (n=7) and non-glutaraldehyde fixation (n=4). The processed explanted pulmonary valved grafts of miniature pig were then transplanted into eleven goats. Calcium quantization was achieved in all of the explanted xenograft, hemodynamic, histopathologic and radiologic evaluations were performed in the graft which the transplantation period was over 300 days (n=7). RESULTS: Grafts treated with glutaraldehyde fixation had more calcification and conduit obstruction in mid-term period. Calcium deposition also appeared much higher in the glutaraldehyde treated graft compared to the non-glutaraldehyde treated graft (p<0.05). CONCLUSION: The present study suggests that xenografts prepared using glutaraldehyde fixation alone appeared to have severe calcification compared to the findings of non-glutaraldehyde treated xenografts and to be managed with proper anticalcification treatment and novel preservation methods. This experiment gives the useful basic chemical, histologic data of xenograft failure model with calcification for further animal study.

Research progress of clinical xenotransplantation / 国际外科学杂志

The shortage of organs and cells from the donors continues to restrict allotransplantation.To carry out the xenotransplantation of pig as the donor is a very important method to alleviate the problem.At present,the organs of pigs (such as islet cells,neurons,liver ceils and cornea) have been initially used in clinical practice.However,significant barriers to be overcome before pig organ xenotransplantation can become a clinical therapy because of the immune and physiological disorders.With pigs that express one or more human thromboregulatory or anti-inflammatory genes being developed,the research of the xenotransplantation has made significant progress,the survival time is logner,at the same time,risk of cross-infection between species is smaller.However,immune rejection and physiological obstacles still prevent organ xenotransplantation from clinical application.This review will draw attention to the latest progress of the xenotransplantation,and provide some references for researchers.

Descelularização como método anticalcificante em próteses valvares de pericárdio bovino sem suporte: estudo em ovinos / Decellularization as an anticalcification method in stentless bovine pericardium valve prosthesis: a study in sheep

OBJETIVO: Avaliar o processo de descelularização com dodecil sulfato de sódio (SDS) como método anticalcificante em próteses de pericárdio bovino fixadas em glutaraldeído, em modelo circulatório de ovinos. MÉTODOS: Tubos valvulados de pericárdio bovino foram implantados em posição pulmonar de ovinos por 180 dias. Os animais foram divididos em dois grupos com oito animais: grupo controle, com condutos de pericárdio fixado em glutaraldeído e grupo estudo, com pericárdio descelularizado com SDS 0,1% e posteriormente fixado em GDA. Os explantes foram submetidos à análise macroscópica, histológica com hematoxilina-eosina, alizarina-red e pentacrômico de Russel-Movatz, estudo radiológico e quantificação de cálcio com espectrometria de absorção atômica. RESULTADOS: Não houve mortalidade imediata, porém dois animais de cada grupo faleceram na evolução tardia. Os enxertos do grupo controle apresentavam intensa calcificação das cúspides e em algumas regiões dos condutos, enquanto que os enxertos descelularizados apresentavam-se preservados, sem calcificações macroscópicas evidentes. Esses resultados foram comprovados por análise histológica e radiográfica. Histologicamente, os enxertos descelularizados tiveram sua matriz melhor preservada e com diminuição acentuada da calcificação. O conteúdo de cálcio nos condutos foi de 35±42 µg/mg de tecido no grupo controle versus 15 ±10 µg/mg nos descelularizados. Nas cúspides valvares, esses valores foram de 264±126 µg/mg no grupo controle versus 94±27 µg/mg nos descelularizados (P=0,009). CONCLUSÃO: A descelularização com SDS 0,1% foi efetiva como método anticalcificante em condutos de pericárdio bovino implantados em modelo circulatório de ovinos por 180 dias.

OBJECTIVE: The objective was to analyze the decellularization process with SDS in glutaraldehyde-preserved bovine pericardium as an anticalcification method in a circulatory sheep model. METHODS: The valved tubs were implanted in pulmonary artery position in sheep by 180 days. The animals were divided in two groups of 8 animals: control group glutaraldehyde-preserved bovine pericardium and the study group - decellularized bovine pericardium with 0,1% SDS and glutaraldehyde-preserved. After explantation the tubs were analized by x-ray macroscopy, hematoxilin-eosin, alizarin-red and Russel-Movatz pentacromic histology. The calcium content was measured by flame atomic absorption spectrometry. RESULTS: There was no early mortality, but two animals in each group died during the study. All cusps in the control group were severely calcified and in some points in the conduits, while the decellularized group did not show macroscopic calcification. Data were proved by x-ray and histologycal exams. The matrix was preserved in histologycal analysis in decellularized group, without gross calcification. The wall conduits calcium content was 35,25±42,13 µg/mg in the control group versus 15,75±10,44 µg/mg in the decellularized one: in the cusps was 264,4±126,16 µg/mg in control group versus 94,29±27,05 µg/mg in decellularized group (P=0,009). CONCLUSION: The decellularization with 0.1% SDS was effective as an anticalcification method in bovine pericardial grafts implanted in a sheep circulatory model for 180 days.

Effect of Hyperkalemia and Hemolysis Caused by Hyperacute Rejection on Cardiac Function in Pig to Human Ex Vivo Xenogeneic Cardiac Perfusion Model

BACKGROUND AND OBJECTIVES: Hyperacute rejection (HAR) is a major obstacle to successful xenotransplantation of vascularized organs. This study was conducted to observe the effect of hemolysis of perfused human whole blood on pig heart function, and determine the major risk factors for preservation of xenoperfused cardiac function using ex-vivo pig to human xenogeneic cardiac perfusion model. MATERIALS AND METHODS: Harvested pig hearts were perfused with normal human whole blood (group 1), two different types of pre-treated human whole blood (group 2: immunoglobulins were depleted by plasmapheresis, group 3: pre-treated with plasmapheresis, GAS914, cobra venom factor (CVF) and steroid), and normal porcine whole blood as control (group 4) for 3 hours. RESULTS: Duration of heart beat was significantly prolonged in group 2 and group 3. Histological examination showed widespread HAR features but was gradually delayed in groups 2 and 3 compared to group 1. The absolute levels of serum creatine kinase-MB and Troponin I increased gradually, and was lower in group 3. Serum hemoglobin levels were rapidly increased in groups 3 and 4, compared to group 1. Extracellular potassium level increased sharply from the beginning of blood perfusion in groups 1, 2 and 3, compared to group 4. CONCLUSION: Pretreatment of human whole blood, including immunoglobulin depletion, CVF and steroid reduced and delayed the destruction of pig myocardium by HAR. However, the increased extracellular potassium levels in groups 1, 2 and 3 reflected that these treatments could not prohibit myocardial injury by HAR.

Research on Polyamidoamine Dendrimers Mediated Foreign Gene for Xenotransplantation Transfected Pig Sperm Cells / 天津医药

Objective:To investigate the effect of the new nanomaterials,polyamidoamine dendrimers PAMAM-D,mediated foreign gene human decay accelerating factor(hDAF) for xenotransplantation transfected pig sperm cells.Methods:PAMAM-D/hDAF cDNA compounds were made.The compounds were divided into 0.2 μg,0.4μg,0.6μg,0.8 μg and 1.0μg groups (each group adding corresponding dose of PAMAM-D in accordance with the N/P ratio 10:1,20:1,40:1),then were digested by restriction enzymes.The compounds were incubated with washed pig sperm cells.Then the transfection efficiency was detected by in situ hybridization in the different groups.Results:The PAMAM-D molecule can prevent electrophoretic migration of DNA in the compound.After digested the compounds by restriction enzymes,DNA can not be degraded.The transfection efficiency was different in different groups.Among the total,the efficiency was higher in both groups of 0.4 μg and 0.6μg than that of others.The top was the group of 0.4 μg linear plasmid plus PAMAM-D when the N/P ratio was 20:1(47.5%±O.2%,167% vs control group).Conclusion:PAMAM-D can improve the efficiency of exogenous gene transfeeted pig sperm cells,which can reinforce the stable binding of exogenous DNA to sperm cells.

Análise do comportamento biológico de heteroenxertos descelularizados e homoenxertos criopreservados: estudo em ovinos / Decellularized heterografts versus cryopreserved homografts: experimental study in sheep model

OBJETIVO: Este estudo avalia o comportamento biológico dos heteroenxertos porcinos descelularizados (Grupo Desc) comparados com os homoenxertos criopreservados (Grupo Crio) implantados em carneiros jovens. MÉTODOS: Foram implantados em cinco animais heteroenxertos pulmonares porcinos descelularizados e em outros cinco, homoenxertos pulmonares criopreservados. Os animais apresentaram seguimento médio de 280 ± 14 dias. O diâmetro valvar foi medido por ecocardiografia, a qual foi realizada no 30º pós-operatório e antes do explante. As valvas foram também avaliadas macroscopicamente. A avaliação histológica foi realizada utilizando-se coloração de H.E., Gomori e Weigert e imunohistoquímica (Fator VIII, CD3, Vimentina e CD68). A quantificação de cálcio foi realizada utilizando-se espectrometria de absorção atômica. RESULTADOS: Houve um óbito no Grupo Desc por endocardite. As valvas do Grupo Crio apresentaram decréscimo na celularidade, enquanto que as valvas do Grupo Desc demonstraram repovoamento da matriz com células endoteliais e intersticiais. No grupo Crio, observou-se perda na densidade e desarranjo da arquitetura das fibras colágenas. A espectrometria de absorção atômica demonstrou maior calcificação no conduto e nas cúspides dos enxertos criopreservados quando comparados aos descelularizados (P=0,016). O diâmetro médio valvar no explante foi significantemente maior no Grupo Desc (P=0,025). CONCLUSÃO: Heteroenxertos descelularizados apresentam um comportamento biológico diferente quando comparados aos homoenxertos criopreservados, tornando-se repovoados por células com características de fibroblastos e células endoteliais. A matriz permaneceu bem preservada, o que possibilitou um processo de regeneração celular.

OBJECTIVES: The aim of this study is to assess the biological behaviour of porcine decellularized heterografts (Desc group) compared with cryopreserved homografts (Crio group) implanted in juvenile sheep. METHODS: Decellularized porcine pulmonary heterografts were implanted in five animals and cryopreserved pulmonary homografts in another five. The animals were followed-up for a mean of 280 ± 14 days. The valve diameter was measured by echocardiography, which was performed at the 30th postoperative day, and before the explantation. The valves were also assessed macroscopically. Histological evaluation was performed using H.E., Gomori and Weigert staining. Immunohistochemistry specified different cell types (Factor VIII, CD3, Vimentin and CD68). Calcium quantity was analyzed using atomic absortion spectometry. RESULTS: There was one death in the Desc group due to endocarditis. The valves of Crio group showed decrease in the cellularity whereas the valves of Desc group showed matrix repopulation with endothelial and interstitial cells. Loss of collagen density and disarrangement of the normal fiber architecture was observed in Crio group. Calcium content demonstrated higher levels on the cusps and conduits in Crio group comparatively with Desc group. (P=0.016). The mean valvular diameter at the explantation was significantly increased (P=0.025) in the Desc group. CONCLUSIONS: Decellularized heterografts had a different biological behaviour when compared to cryopreserved homografts and become repopulated by cells with fibroblasts and endothelial cells characteristics. The matrix was preserved and some regenerative potential was present