In vivo evaluation of deer antler trabecular bone as a reconstruction material for bone defects.

Availability of graft materials to fill up osseous defects has always been a concern in orthopaedic surgeries. Deer antler material is a primary bone structure that is easy to collect and could serve as a xenograft. This study examines the behaviour of red deer antler trabecular cylinders in critical size distal femoral epiphyseal defects in 11 rabbits, and evaluates the effect of the decellularization protocols. Two preparation regimes (A and B) were used, with and without lipids and proteins. Radiographs were taken immediately after surgery and after euthanasia 12 weeks post-implantation. Histological evaluation was performed on non-decalcified 10-µm sections with a van Gieson picro-fuchsin staining protocol. A region of interest was defined for each histological section, evaluating the inflammatory reaction, the fibrosis process, and the osteogenesis. Each histological section was microradiographed to evaluate bone contact, presence of synostosis, remodelling and ossification processes. All antler cylinders were successfully implanted. Final radiographic analysis demonstrated osteointegration of most implants at various stages. Light to moderate inflammation around the grafts was noted with only one case showing full encapsulation. A variable degree of intimacy between implant and host bone was evidenced, with bone remodelling and osteogenesis of various intensity being present in all implanted sites. No differences were found between group A and B. Removal of lipids and proteins in the grafts surprisingly did not seem to matter. Decellularization and sterilization protocols may be advocated. Although it presents several limitations, this study shows some promising results regarding antler trabecular bone osteointegration.

Community Hospital Experience With Bovine Tissue in Infected Vascular Fields.

BACKGROUND: Vascular prosthetic graft infections are rare but associated with high morbidity and mortality. Treatment involves removal of the infected graft requiring arteriotomy closure. Previously this was performed with autologous graft, but bovine tissue has increasingly been used. The objective of this paper is to review the community hospital experience with bovine tissue repair in an infected vascular field. MATERIALS AND METHODS: A retrospective review of all cases performed by a single surgeon in a community hospital for infected prosthetic grafts was completed. Sixteen cases were included where bovine tissue was used for repair. Presentation, location of graft, and causative organism were reviewed, and outcomes including reoperation and mortality were recorded. RESULTS: Of the 16 patients, 15 (94%) had positive cultures of the graft. Methicillin-Resistant Staph Aureus was the most commonly isolated organism (50%). There were 3 unplanned reoperations including a revision from below to above knee amputation, drainage of a hematoma, and a wound debridement within the first year. Over the 1 year follow up period, 3 patients died for a mortality of 19%. There were no reinfections during follow-up. DISCUSSION: Prosthetic graft infection is a rare but serious vascular surgery complication. The causative organism has shifted in the last few years to become increasingly drug resistant. Treatment requires excision, and bovine tissue has been demonstrated to provide a safe and durable method of repair.

Pulmonary artery "conduit" reconstruction using bovine pericardium following long-segment sleeve resection: a unique "in situ tailor-made" sewing method.

We describe a unique technique for pulmonary artery reconstruction using a bovine pericardial conduit after long-segment sleeve resection of the pulmonary artery. In this technique, the conduit tube was not created in advance but was sewn in situ from a bovine pericardial "sheet" step-by-step to form a desirable diameter, length and curve to fit the vascular defect. This is a safe and secure method to create desirable conduit for long and complex pulmonary artery replacement.

Ultrasound-Guided Approaches to Improve Orthotopic Mouse Xenograft Models for Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is the second leading cause of cancer death worldwide. While curative approaches for early stage HCC exist, effective treatment options for advanced HCC are lacking. Furthermore, there are no efficient chemopreventive strategies to limit HCC development once cirrhosis is established. One challenge for drug development is unsatisfactory animal models. In this article, we describe an orthotopic xenograft mouse model of human liver cancer cell lines through image-guided injection into the liver. This technique provides a less invasive yet highly efficient approach to engraft human HCC into mouse liver. Similarly, image-guided injections are used to deliver chemotherapeutics locally, enabling reduction in potential systemic adverse effects, while reducing the required dose for a therapeutic effect. In summary, this image-guided strategy provides a novel and convenient approach to improve current HCC mouse models. © 2019 The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Pathogen elimination and prevention within a regulated, Designated Pathogen Free, closed pig herd for long-term breeding and production of xenotransplantation materials.

BACKGROUND: We established a Source Animal (barrier) Facility (SAF) for generating designated pathogen-free (DPF) pigs to serve as donors of viable organs, tissues, or cells for xenotransplantation into clinical patients. This facility was populated with caesarian derived, colostrum deprived (CDCD) piglets, from sows of conventional-specific (or specified) pathogen-free (SPF) health status in six cohorts over a 10-month period. In all cases, CDCD piglets fulfilled DPF status including negativity for porcine circovirus (PCV), a particularly environmentally robust and difficult to inactivate virus which at the time of SAF population was epidemic in the US commercial swine production industry. Two outbreaks of PCV infection were subsequently detected during sentinel testing. The first occurred several weeks after PCV-negative animals were moved under quarantine from the nursery into an animal holding room. The apparent origin of PCV was newly installed stainless steel penning, which was not sufficiently degreased thereby protecting viral particles from disinfection. The second outbreak was apparently transmitted via employee activities in the Caesarian-section suite adjacent to the barrier facility. In both cases, PCV was contained in the animal holding room where it was diagnosed making a complete facility depopulation-repopulation unnecessary. METHOD: Infectious PCV was eliminated during both outbreaks by the following: euthanizing infected animals, disposing of all removable items from the affected animal holding room, extensive cleaning with detergents and degreasing agents, sterilization of equipment and rooms with chlorine dioxide, vaporized hydrogen peroxide, and potassium peroxymonosulfate, and for the second outbreak also glutaraldehyde/quaternary ammonium. Impact on other barrier animals throughout the process was monitored by frequent PCV diagnostic testing. RESULT: After close monitoring for 6 months indicating PCV absence from all rooms and animals, herd animals were removed from quarantine status. CONCLUSION: Ten years after PCV clearance following the second outbreak, due to strict adherence to biosecurity protocols and based on ongoing sentinel diagnostic monitoring (currently monthly), the herd remains DPF including PCV negative.

Creation of Experimental Human Nose Model With Lyophilized and Decellularized Bovine Cartilage Xenograft.

The nose anatomy is a functional and aesthetically important organ because of its three-dimensional structure, visible location in the face region, and its connection with the respiratory tract. Aesthetic and reconstructive nasal surgery requires correction of deformations in cartilage and bone structures as well as preservation of the natural connections between all subunits. The minimal mistake made can result in functional or aesthetically bad results. In this study, the authors aimed to create an experimental nose model that help aesthetic and reconstructive nose surgery operations.

Desenvolvimento de xenotransplantes de tumores pancreáticos humanos para varredura genética de alvos moleculares com potencial terapêutico / Establishment of xenografts from human pancreatic tumors for genetic screening of molecular targets with therapeutic potential

O adenocarcinoma ductal pancreático (PDAC, pancreatic ductal adenocarcinoma), o tipo mais prevalente de câncer do pâncreas, é uma neoplasia extremamente agressiva e com elevado índice de letalidade. Há uma necessidade premente de identificação de vulnerabilidades no PDAC que possam ser exploradas como alvos terapêuticos, e a utilização de modelos pré-clínicos que recapitulem a complexidade biológica e heterogeneidade clínica da doença é um aspecto central para a realização dessa tarefa. Os xenotransplantes de tecido tumoral derivado de pacientes (PDX, patient-derived tumor tissue xenografts), realizados em camundongos imunodeficientes, replicam com grande similaridade as principais características do tumor original e, assim, constituem uma ferramenta valiosa para o teste de drogas e estudos funcionais. Neste trabalho, 17 amostras cirúrgicas de PDAC humano foram implantadas subcutaneamente em camundongos nude atímicos. Sete tumores (41%) foram enxertados com sucesso e têm sido mantidos em sucessivas gerações de animais receptores. O exame histológico de seis desses xenoenxertos identificou características morfológicas compatíveis com os padrões reconhecidos no PDAC humano, assim como uma consistente similaridade de seu status de diferenciação histológica em relação aos perfis verificados nos tumoresoriginais. O cultivo in vitro de células derivadas de um dos xenotumores resultou em uma nova linhagem de câncer de pâncreas, com morfologia e cinética de crescimento comparáveis às de outras linhagens celulares de câncer pancreático. O potencial tumorigênico dessa nova linhagem foi validado in vivo, com uma consistente formação de tumores após inoculação em camundongos nude. A fim de aproveitar esse recurso para a investigação de potenciais alvos terapêuticos no PDAC, um rastreamento de vulnerabilidades moleculares foi realizado por meio de silenciamento gênico em larga-escala com RNA de interferência (RNAi). Uma biblioteca lentiviral de 4492 shRNAs (short hairpin RNAs), alvejando cerca de 350 genes envolvidos na regulação epigenética, foi empregada para a triagem de genes de suscetibilidade nas células derivadas de PDX, e em outras cinco linhagens tumorais pancreáticas (AsPC-1, BxPC-3, Capan-1, MIA PaCa-2 e PANC-1). Inicialmente, foi realizada uma série de experimentos preliminares, visando à amplificação e controle de qualidade da biblioteca de silenciamento, à produção de vetores lentivirais e à padronização das condições experimentais para a transdução e seleção das células-alvo. Apenas três das linhagens avaliadas (AsPC-1, MIA PaCa-2 e PANC-1) mostraram-se permissíveis à transdução pelos vetores lentivirais, e foram assim utilizadas no screening de alvos epigenéticos. A análise dos dados obtidos nesse ensaio está em curso e os resultados serão utilizados para a definição de potenciais alvos candidatos. Em conclusão, recursos valiosos para apoiar a pesquisa sobre o câncer de pâncreas foram desenvolvidos. A coleção de PDXs estabelecida, bem como a linhagem celular recém-derivada, constituem uma fonte permanente e estável de células de PDAC para análises moleculares e estudos funcionais que busquem elucidar aspectos da doença ainda pouco compreendidos. Adicionalmente, os reagentes gerados e a expertise adquirida com os ensaiosrealizados com a biblioteca de shRNAs contra alvos epigenéticos serão de grande utilidade em futuras investigações para identificar genes com funções importantes na manutenção do fenótipo tumoral, e consequentemente com potencial para serem explorados terapeuticamente

Pancreatic ductal adenocarcinoma (PDAC), the most prevalent type of pancreatic cancer, is a highly aggressive and lethal neoplasm. There is a pressing need to identify vulnerabilities in PDAC suited to be exploited as therapeutic targets, and the use of preclinical models recapitulating the biological complexity and clinical heterogeneity of the disease is central to this task. Patient-derived tumor tissue xenografts (PDX), established in immunodeficient mice, replicate with great similarity the main characteristics of the original tumor and thus constitute a valuable tool for drug testing and functional studies. In this work, 17 surgical samples of human PDAC were implanted subcutaneously in athymic nude mice. Seven tumors (41%) were successfully grafted and have been maintained through successive generations of recipient animals. Histological examination of six of these xenografts identified morphological characteristics compatible with the recognized patterns of human PDAC, as well as a consistent similarity of their histological differentiation status in relation to the profiles verified in the original tumors. In vitro culture of cells derived from one of these xenografts resulted in a new pancreatic cancer cell line, with morphology and growth kinetics comparable to those of other pancreatic tumor cells. The tumorigenic potential of this freshly derived cell line was validated in vivo, with a consistent tumor formation following inoculation into nude mice. To take advantage ofthis resource to investigate potential therapeutic targets in PDAC, a screening of molecular vulnerabilities was performed through large-scale gene silencing with RNA interference (RNAi). A lentiviral library containing 4492 short hairpin RNAs (shRNAs), targeting about 350 genes involved in epigenetic regulation, was employed for the search of susceptibility genes in the PDX-derived cells and in other five pancreatic tumor cell lines (AsPC-1, BxPC -3, Capan-1, MIA PaCa-2 and PANC-1). Initially, a series of preliminary experiments were carried out aiming at the amplification and quality control of the silencing library, production of lentiviral vectors and adjustment of the experimental conditions for transduction and selection of the target cells. Only three of the cell lines evaluated (AsPC-1, MIA PaCa-2 and PANC-1) were permissible for transduction by the lentiviral vectors, and were accordingly used in the screening of epigenetic targets. The analysis of data obtained in this trial is ongoing and the results will be used for definition of potential candidate targets. In conclusion, valuable resources to support research on pancreatic cancer have been developed. The established collection of PDXs as well as the newly derived cell line constitutes a permanent and stable source of PDAC cells for molecular analyzes and functional studies seeking to elucidate aspects of this disease that are still poorly understood. Additionally, both the reagents generated and the expertise gained from the RNAi assay against epigenetic targets will have inordinate usefulness in future investigations to identify genes with major functions in maintaining the malignant phenotype, and consequently with the potential to be exploited therapeutically

Self Made Xeno-pericardial Aortic Tubes to Treat Native and Aortic Graft Infections.

OBJECTIVES: The most appropriate material for reconstruction of the aorta for native or graft infection remains a matter for debate. This study examines the mid-term outcome of patients and graft durability after in situ aortic reconstruction with self made bovine pericardial tube grafts. METHODS: This was a retrospective analysis of all patients who underwent in situ aortic reconstruction using self made bovine pericardial tube grafts between January 2008 and December 2015 at a tertiary referral centre. Peri-operative and mid-term outcomes including mortality and re-infection were analysed at the end of January 2017. Available follow-up imaging was reviewed to assess graft durability. RESULTS: Bovine pericardial aortic tube grafts were used in 35 patients (86% male) with a median age of 69 years (range 38-84) to reconstruct the ascending aorta or the aortic arch (7), the descending (7), the thoraco-abdominal (7), or the abdominal (14) aorta. Twelve patients (34%) were treated for infection of the native aorta and 23 (66%) for prosthetic graft infection. Twenty-two patients (63%) underwent emergency surgery. Thirty day mortality was 31% (n = 11). Additionally, six patients died during follow-up after a median of 33 months (range 3-70). For the remaining patients, mean follow-up was 48 months (± 26) with a mean Follow-Up Index of 0.98 ± 0.08. There were no readmissions or re-operations for re-infection or graft related complications. Follow-up imaging showed no signs of graft degeneration after a median of 15 months (range 3-68). CONCLUSIONS: Surgical treatment of native and aortic graft or endograft infection remains high risk. Self made bovine pericardial tube grafts for in situ reconstruction are a promising option offering many advantages. Despite high early mortality rates, early radiological and mid-term clinical results are good. Definitive eradication of the infection seems feasible after in situ insertion of xeno-pericardial material for aortic repair.

Xenotransplantation Model of Psoriasis.

Psoriasis is a chronic autoimmune skin disease affecting approximately 2 % of the population with a major psychosocial and socioeconomic impact. A causal therapy leading to permanent cure is not available, and current treatments only lead to limited amelioration, and therefore new therapeutic targets need to be identified. Recent works demonstrated a predominant role of TH17 cells in the pathogenesis of psoriasis; yet the underlying molecular mechanisms driving the development of the disease are still largely elusive. Several mouse models of psoriasis including drug-induced models (topical application of imiquimod to the skin) and genetically engineered mice (constitutive activation of epidermal STAT3, epidermal deletion of JunB/c-Jun, and epidermal overexpression of Tie2) have been used to study the pathophysiology of the disease; however such models cannot fully recapitulate all molecular and cellular pathways occurring in human psoriasis. Xenotransplantation of human pre-psoriatic skin onto immunodeficient mice and triggering its conversion into a psoriatic plaque is the best model to dissect the mechanisms occurring during the development of human psoriasis. One model is based on the transplantation of human pre-psoriatic skin onto SCID mice followed by the transfer of activated autologous T cells. The ex vivo activation of T cells required to induce the psoriatic conversion of the graft limits the study of early events in the pathogenesis of psoriasis. Another model is based on transplantation of human pre-psoriatic skin onto AGR129 mice. In this model, the skin grafting is sufficient to activate human cells contained in the graft and trigger the conversion of the graft into a psoriatic skin, without the need of transferring activated T cells. Here we review the methodological aspects of this model and illustrate how this model can be used to dissect early events of psoriasis pathogenesis.

The efficacy of an immunoisolating membrane system for islet xenotransplantation in minipigs.

Developing a device that protects xenogeneic islets to allow treatment and potentially cure of diabetes in large mammals has been a major challenge in the past decade. Using xenogeneic islets for transplantation is required in light of donor shortage and the large number of diabetic patients that qualify for islet transplantation. Until now, however, host immunoreactivity against the xenogeneic graft has been a major drawback for the use of porcine islets. Our study demonstrates the applicability of a novel immunoprotective membrane that allows successful xenotransplantation of rat islets in diabetic minipigs without immunosuppressive therapy. Rat pancreatic islets were encapsulated in highly purified alginate and integrated into a plastic macrochamber covered by a poly-membrane for subcutaneous transplantation. Diabetic Sinclair pigs were transplanted and followed for up to 90 days. We demonstrated a persistent graft function and restoration of normoglycemia without the need for immunosuppressive therapy. This concept could potentially offer an attractive strategy for a more widespread islet replacement therapy that would restore endogenous insulin secretion in diabetic patients without the need for immunosuppressive drugs and may even open up an avenue for safe utilization of xenogeneic islet donors.

Tratamiento de un defecto vertical profundo en un pilar protético mediante la técnica de regeneración tisular guiada: evaluación clínica y radiográfica con reentrada a los 12 meses (AU) / Treatment of a deep vertical intrabony defect in a prosthetic abutment by means of guided tissue regeneration: clinical and radiographic evaluation with re-entry procedure 12 months later

Objetivo: evaluar clínica y radiográficamente el tratamiento de un defecto vertical profundo en un pilar protético mediante la técnica de regeneración tisular guiada (RTG). Caso clínico: se presenta el tratamiento de un defecto vertical profundo mediante una técnica combinada de injerto bovino y membrana de colágeno. Los parámetros clínicos y radiográficos fueron evaluados al incicio y 12 meses después, momento en el cual se realizó una reentrada quirúrgica para evaluar la regeneración obtenida. Conclusión: los resultados clínicos mostraron una mejoría en los parámetros evaluados y radiográficamente, un año después, se observó un alto grado de regeneración. La utilización de esta técnica (RTG) en pilares dentarios estratégicos permite mejorar el pronóstico periodontal de la pieza dentaria y posteriormente, incluirlos en la futura rehabilitación protética. Más allá de las limitaciones de este estudio, los resultados sugieren que la terapia regenerativa combinada es eficaz para el tratamiento de pilares periodontalmente comprometidos.

Equine pericardial roll graft replacement of infected pseudoaneurysm of the aortic arch.

Resection of the infected aorta, debridement of the surrounding tissue, in situ graft replacement, and omentopexy is the standard procedure for treating infected aortic aneurysms, but the question of which graft material is optimal is still a matter of controversy. We recently treated a patient with an infected thoracic aortic aneurysm. The aneurysm was located in the proximal aortic arch. Because the patients had previously undergone abdominal surgery, the aortic arch were replaced in situ with a branched equine pericardial roll grafts. The patient is alive and well 23 months after the operation.

Torsional stability of interference screws derived from bovine bone--a biomechanical study.

BACKGROUND: In the present biomechanical study, the torsional stability of different interference screws, made of bovine bone, was tested. Interference screws derived from bovine bone are a possible biological alternative to conventional metallic or bioabsorbable polymer interference screws. METHODS: In the first part of the study we compared the torsional stability of self-made 8 mm Interference screws (BC) and a commercial 8 mm interference screw (Tutofix). Furthermore, we compared the torsional strength of BC screws with different diameters. For screwing in, a hexagon head and an octagon head were tested. Maximum breaking torques in polymethyl methacrylate resin were recorded by means of an electronic torque screw driver. In the second part of the study the tibial part of a bone-patellar tendon-bone graft was fixed in porcine test specimens using an 8 mm BC screw and the maximum insertion torques were recorded. Each interference screw type was tested 5 times. RESULTS: There was no statistically significant difference between the different 8 mm interference screws (p = 0.121). Pairwise comparisons did not reveal statistically significant differences, either. It was demonstrated for the BC screws, that a larger screw diameter significantly leads to higher torsional stability (p = 9.779 x 10(-5)). Pairwise comparisons showed a significantly lower torsional stability for the 7 mm BC screw than for the 8 mm BC screw (p = 0.0079) and the 9 mm BC screw (p = 0.0079). Statistically significant differences between the 8 mm and the 9 mm BC screw could not be found (p = 0.15). During screwing into the tibial graft channel of the porcine specimens, insertion torques between 0.5 Nm and 3.2 Nm were recorded. In one case the hexagon head of a BC screw broke off during the last turn. CONCLUSIONS: The BC screws show comparable torsional stability to Tutofix interference screws. As expected the torsional strength of the screws increases significantly with the diameter. The safety and in vivo performance of products derived from xenogeneic bone should be the focus of further investigations.

Cervical spinal cord therapeutics delivery: preclinical safety validation of a stabilized microinjection platform.

OBJECTIVE: The current series represents a preclinical safety validation study for direct parenchymal microinjection of cellular grafts into the ventral horn of the porcine cervical spinal cord. METHODS: Twenty-four 30- to 40-kg female Yorkshire farm pigs immunosuppressed with cyclosporine underwent a cervical laminectomy and ventral horn human neural progenitor cell injection. Cell transplantation in groups 1 to 3 (n = 6 pigs each) was undertaken with the intent of assessing the safety of varied injection volumes: 10, 25, and 50 microL injected at 1, 2.5, and 5 microL/min, respectively. Groups 4 and 5 (n = 3 pigs each) received prolonged immunosuppressant pretreatment in an attempt to demonstrate graft viability. The latter was undertaken in an alternate species (mini-pig versus Yorkshire pig). RESULTS: Neurological morbidity was observed in 1 animal and was attributable to the presence of a resolving epidural hematoma noted at necropsy. Although instances of ventral horn targeting were achieved in all injection groups with a coordinate-based approach, opportunities exist for improvement in accuracy and precision. A relationship between injection volume and graft site cross-sectional area suggested limited reflux. Only animals from group 5 achieved graft survival at a survival end point (t = 1 week). CONCLUSION: This series demonstrated the functional safety of targeted ventral horn microinjection despite evidence for graft site immune rejection. Improvements in graft delivery may be augmented with an adapter to improve control of the cannula entry angle, intraoperative imaging, or larger graft volumes. Finally, demonstration of long-term graft viability in future preclinical toxicity studies may require tailored immunosuppressive therapies, an allograft construct, or tailored choice of host species.

Contribution of the xenograft bone plate-screw system in lumbar transpedicular stabilization of dogs: an in-vitro study.

We performed biomechanical comparison of a xenograft bone plate-screw (XBPS) system for achieving cadaveric lumbar transpedicular stabilization (TS) in dogs. Twenty dogs' cadaveric L(2-4) lumbar specimens were harvested and their muscles were removed, but the discs and ligaments were left intact. These specimens were separated to four groups: the L(2-4) intact group as control (group I, n = 5), the L(3) laminectomy and bilateral facetectomy group (LBF) (group II, n = 5), the LBF plus TS with metal plate-screw group (group III, n = 5) and the LBF plus TS with XBPS group (group IV, n = 5). Five kinds of biomechanical tests were applied to the specimens: flexion, extension, left-right bending and rotation. The averages of the 16 stiffness values were calculated and then these were statistically analyzed. The statistical results show that the XBPS system contributes spinal stability and this system can be a good choice for achieving TS.

Expanding the utilization of Contegra for ventricular septal defect repair.

Different patch materials have been utilized in repairing ventricular septal defect (VSD) with great success. In this report, in addition to the right ventricular outflow tract reconstruction, the VSD was repaired successfully in all cases by fashioning a patch from a segment of the Contegra xenograft conduit. The freedom from infection, thromboembolism, and reintervention during follow-up, in addition to the advantage of ready availability and cost-effectiveness offered by using the same bovine material, imply that Contegra xenograft is a promising alternative patch material for VSD repair.

Progress towards clinical xenotransplantation.

Xenotransplantation has progressed from early heroic experiments on the path to meet the ever increasing demands of tissue and organ transplantation in patients with end-stage organ failure. The pig species is regarded as the most promising donor species. However, due to the evolutionary distance, innovative approaches are to be developed to permit life-supporting function in humans. Transplantation of organs from non-human primates has increased our knowledge on rejection mechanisms and provided opportunities for testing modified immunosuppression of the host and genetic modification of the donor. The development of transgenic animals expressing human complement-regulatory factors, and of animals lacking the target for naturally occurring anti-pig antibodies, has essentially eradicated hyperacute rejection of solid organs. However, there is still a need for tolerable immunosuppression or immune-tolerance regimens to provide broadly available procedures in the clinical setting. Safety concerns especially cross-species transmission of infectious pathogens, in particular of porcine endogenous retrovirus. Many studies have indicated that this is highly unlikely. At present, cell and tissue transplantation of islets of Langerhans to diabetic patients is close to being tested in well-designed clinical trials. Further research is required before other porcine xenografts can offer a broadly available therapeutic option in clinical medicine.

Mesa quirúrgica para la recepción y preparación de injertos óseos en bloque / Surgical table for the reception and preparation of block bone grafts

La Implantología provocó una bisagra en la Rehabilitación Bucal moderna. La predictibilidad de los implantes llegó a porcentajes quizás impensados. Sin embargo, el giro evolutivo encuentra a la profesión hoy, cuestionando la ya vieja visión de colocar los implantes en el hueso residual existente. La reconstrucción del reborde maxilar exiguo puede entre otras formas ser realizada a partir de los injertos en bloque. Esta técnica antigua pero delicada y necesariamente precisa, disponía de mucho instrumental de mano pero carecía de un lugar de trabajo en la clásica mesa de Finochietto o en algúnotro lugar del quirófano, adecuado para esos fines. La mesa que hoy se publica es una herramienta eficaz para el manejo mas exacto de los injertos en bloque autólogos, homólogos, heterólogos o sintéticos, permitiendouna técnica más segura y precisa.