Endothelial assessment of donated tectonic corneas: a viable option for posterior lamellar transplantation.

PURPOSE: Donated corneas are classified as tectonic if there are defects within any layers of the cornea which would prevent a satisfactory visual outcome after transplantation. This study aimed to evaluate whether some tectonic corneas have sufficient endothelial characteristics to allow their use in posterior lamellar keratoplasty, and explored their reclassification for use in this sight-improving procedure. METHODS: A retrospective review of all corneal tissues preserved by the Sorocaba Eye Bank from January to April of 2014 was performed. All donated corneas classified as tectonic were included. Endothelial tissue was defined as healthy and viable for posterior lamellar keratoplasty if endothelial cell density was ≥2000 cells/mm2. Additional parameters analyzed included Descemet folds and stretch marks, loss of endothelial cells, corneal endothelial polymegathism/ pleomorphism, pseudo-guttata, and reflectivity. RESULTS: During the study period, 2,847 corneas were preserved, of which 423 (14.85%) were classified as tectonic. Of these, 87 (20.56%) were reported as having endothelial viability and were included in the posterior lamellar keratoplasty group. Average corneal endothelial cell density of this group was 2,471 SD ± 256 cells/mm2 (range 2012-2967 cells/mm2). CONCLUSION: A significant number of corneas classified as tectonic showed endothelial viability and were included in the posterior lamellar keratoplasty group (20.56%). Despite stromal and/or epithelial alterations, these corneas could have been potentially distributed for posterior lamellar transplantation to improve vision, thus reducing the corneal transplantation waiting period. This study highlights how corneal tissue reclassification could increase the potential amount of corneal tissue available for optical transplantation.

Endothelial assessment of donated tectonic corneas: a viable option for posterior lamellar transplantation / Avaliação da viabilidade do uso de córneas tectônicas em transplantes lamelares posteriores a partir da análise da vitalidade das células endoteliais

ABSTRACT Purpose: Donated corneas are classified as tectonic if there are defects within any layers of the cornea which would prevent a satisfactory visual outcome after transplantation. This study aimed to evaluate whether some tectonic corneas have sufficient endothelial characteristics to allow their use in posterior lamellar keratoplasty, and explored their reclassification for use in this sight-improving procedure. Methods: A retrospective review of all corneal tissues preserved by the Sorocaba Eye Bank from January to April of 2014 was performed. All donated corneas classified as tectonic were included. Endothelial tissue was defined as healthy and viable for posterior lamellar keratoplasty if endothelial cell density was ≥2000 cells/mm2. Additional parameters analyzed included Descemet folds and stretch marks, loss of endothelial cells, corneal endothelial polymegathism/ pleomorphism, pseudo-guttata, and reflectivity. Results: During the study period, 2,847 corneas were preserved, of which 423 (14.85%) were classified as tectonic. Of these, 87 (20.56%) were reported as having endothelial viability and were included in the posterior lamellar keratoplasty group. Average corneal endothelial cell density of this group was 2,471 SD ± 256 cells/mm2 (range 2012-2967 cells/mm2). Conclusion: A significant number of corneas classified as tectonic showed endothelial viability and were included in the posterior lamellar keratoplasty group (20.56%). Despite stromal and/or epithelial alterations, these corneas could have been potentially distributed for posterior lamellar transplantation to improve vision, thus reducing the corneal transplantation waiting period. This study highlights how corneal tissue reclassification could increase the potential amount of corneal tissue available for optical transplantation.

RESUMO Objetivo: Avaliar a vitalidade endotelial das córneas classificadas como tectônicas e discutir a viabilidade de seu uso na ceratoplastia lamelar posterior. Métodos: Realizou-se uma revisão retrospectiva de todos os tecidos corneanos preservados pelo Banco de Olhos Sorocaba de janeiro a abril de 2014. Todas as córneas doadas classificadas como tectônicas foram incluídas e avaliadas com ênfase na vitalidade endotelial. Os parâmetros de avaliação da lâmpada de fenda de cada córnea e densidade de células endoteliais medidos por microscópio especular foram registrados: córneas que apresentavam vitalidade endotelial apesar de alterações no estroma e/ou no epitélio foram selecionadas e incluídas em um grupo denominado grupo lamelar posterior. O tecido endotelial foi definido como saudável e viável para a ceratoplastia lamelar posterior, se houvesse uma densidade de células endoteliais ≥2.000 células/mm2. Outros parâmetros também foram analisados, incluindo; estrias ou pregas na Descemet, perda de células endoteliais, polimegatismo e pleomorfismo endotelial, pseudo-guttata e reflexividade endotelial. Resultados: Durante o período do estudo, foram preservadas 2.847 córneas, das quais 423 (14,85%) foram classificadas como tectônicas. Dessas, 87 (20,56%) apresentaram vitalidade endotelial e foram incluídos no grupo lamelar posterior. A densidade média das células endoteliais da córnea deste grupo era de 2.471 SD ± 256 células/mm2, variando de 2.012 a 2.967 células/mm2. Conclusão: Um número significativo de córneas classificadas como tectônicas apresentaram vitalidade endotelial e foram incluídas no grupo lamelar posterior (20,56%). Apesar de alterações estromais e/ou epiteliais, estas córneas poderiam ter sido potencialmente distribuídas para transplantes lamelares posteriores com finalidade ótica, otimizando a disponibilidade de tecidos, com impacto positivo na saúde pública.

Diaphanization: a standardized protocol for non-fetal tissue preservation / Diafanización: un protocolo estandarizado para la preservación de tejido adulto

In response to the arising difficulty of dissection use during anatomy courses, medical schools have been forced to research alternative teaching methods. These are meant to help students develop three dimensional mental images of the human body and increase spatial reasoning, thus improving the learning process of human morphology. One of those methods, used at the Universidad de los Andes is the Diaphanization process. This technique is a well-known method for specimen preservation, used as an anatomy research and teaching tool. Even though it is frequently used, finding a standardized protocol in indexed journals is not possible, which hinders the use of the technique. The standardization of an updated protocol is a need in order to continue exploiting the maximum educational capacity of the specimens used during classwork. The process used at the Universidad de los Andes for non-fetal tissue preservation by Diaphanization is described, with a detailed explanation of its five main stages: Injection, Fixation, Dehydration, Bleaching (or Maceration) and Final preservation. The final result should be an organ preserved in an acrylic box which allows clear three dimensional visualization of anatomical structures that can be used for the study and description of general anatomy and vascular structure. It also helps with spatial reasoning and represents little to no biological risk, leading to a new level of anatomical teaching and experimenting. Several specimens obtained at our laboratory through this technique are presented.

Como respuesta a la dificultad del uso de disección como una herramienta en el curso de anatomía, las escuelas de medicina se han visto forzadas a investigar y desarrollar métodos alternativos que la reemplacen. Estos pretenden estimular el desarrollo de la percepción tridimensional de los estudiantes, logrando mejor racionamiento espacial, y así, mejorando el proceso de aprendizaje de la morfología humana. Uno de estos métodos, en uso en la Universidad de los Andes, es el proceso de diafanización. Esta técnica es ampliamente conocida en el ámbito de preservación de tejidos, y empleada en investigación y educación. Aún con su uso frecuente, un protocolo estandarizado que la describa no está disponible en la literatura indexada, lo cual limita su uso. La estandarización de un protocolo actualizado es necesaria para permitir el continuo uso de esta técnica. Se describe el proceso de preservación de tejido adulto mediante la diafanización, con una explicación detallada de los 5 pasos que la componen: Inyección, Fijación, Deshidratación, Macerado y Preservación final. El resultado es un órgano inmerso en glicerina en un contenedor de acrílico que permite una visualización tridimensional de las estructuras anatómicas del espécimen, que puede ser empleado por los estudiantes para su estudio, y permite una descripción de la anatomía general del modelo y su estructura vascular. Adicionalmente incrementa el razonamiento espacial de los estudiantes, y no presenta ningún riesgo biológico. Se presentan una variedad de especímenes de características particulares obtenidos mediante la aplicación de esta técnica.

[Mexican National Consensus on Assisted Reproduction Treatment]. / Consenso Nacional Mexicano de Reproducción Asistida.

BACKGROUND: It is estimated that 15% of couples living in industrialized countries are infertile, ie have failed to conceive, reproductive age, after 12 months ormore of regular intercourse without contraception. During the past decade has increased the demand for fertility treatments because they believe are moreeffective now. OBJECTIVE: To unify the therapeutic approach and service to patients and set a precedent for a Mexican Official Standard respect and support for the legislation of these procedures. METHOD: Consensus by technical experts group panel with the participation of 34 national centers accredited for use in assisted reproduction. He organized seven workshops with the following themes: 1) selection of patients for assisted reproduction treatment, 2) schemes controlled ovarian stimulation for assisted reproduction techniques of high complexity, 3) preparation and egg retrieval technique, 4) transferembryo; 5) luteal phase supplementation; 6) indications and techniques of cryopreservation and 7) informed consent. Each table had a coordinator who wrote and presented the findings to the full, it made a number of observations until they reached unanimity of criteria, which are reflected in this document. RESULTS: Patient selection for assisted reproduction techniques is the first step of the process. Proper selection lead to success, in the same way that a bad pick up for failure. In the case of egg donation the most important recommendation is that only one to two embryos transferred in order to reduce multiple pregnancy rates and maintaining high pregnancy rates.

Microbiota bacteriana aeróbia da conjuntiva de doadores de córnea / Aerobic bacterial microbiota of the conjunctiva of cornea donors

OBJETIVOS: Determinar a microbiota bacteriana aeróbia da conjuntiva de doadores de córnea e seu padrão de suscetibilidade a antibióticos; verificar o número de córneas utilizadas para transplante e a média de tempo de preservação em solução preservante com gentamicina e estreptomicina; traçar o perfil dos doadores e receptores de córnea. MÉTODOS: Espécimes clínicos foram colhidos de saco inferior da conjuntiva de ambos os olhos, de 40 doadores de córnea. As amostras foram inoculadas em ágar sangue azida, ágar chocolate e ágar MacConkey e o antibiograma foi realizado pelo método de Kirby-Bauer. RESULTADOS: A freqüência de cultura positiva da conjuntiva de doadores de córnea foi de 72,5 por cento, sendo que Gram-positivos totalizaram 81,6 por cento e apenas 18,4 por cento das amostras foram identificadas como Gram-negativos. Vancomicina inibiu 100 por cento dos Gram-positivos, ao passo que a sensibilidade dos Gram-negativos à gentamicina foi de 53,8 por cento e à estreptomicina foi de 30 por cento. O sexo masculino predominou entre os doadores e receptores, a média de tempo entre o óbito e a enucleação foi de 2h e a de preservação em solução preservante com gentamicina e estreptomicina foi de 7 dias. Neoplasia e mais de uma causa associada foram as causas de óbito mais freqüentes. O ceratocone foi a principal indicação para transplante (51,7 por cento). CONCLUSÕES: Staphylococcus coagulase negativo foi o microrganismo com o maior número de isolamentos, apresentando sensibilidade variada aos antimicrobianos. A quantidade de córneas utilizadas para transplante foi bastante inferior em relação ao total de captações. O perfil dos doadores e receptores de córnea mostrou-se heterogêneo para grande parte das variáveis analisadas.

PURPOSE: To determine aerobic bacterial microbiota of the conjunctiva of cornea donors and its patterns of susceptibility to antibiotics; verify the number of corneas used for transplant and the average time of preservation in solutions with gentamicin and streptomycin; trace the profile of donors and receptors of cornea. METHODS: Clinical specimens were collected from the inferior bag of the conjunctiva of both eyes of 40 cornea donors. The samples were inoculated into acid blood, chocolate and MacConkey agars, and the antibiogram was performed by the Kirby-Bauer method. RESULTS: The frequency of positive cultures of the conjunctiva of cornea donors was 72.5 percent, with Gram-positive totalling 81.6 percent and only 18.4 percent of the samples were identified as Gram-negative. Vancomycin inhibited 100 percent of Gram-positive microorganisms, while sensitivity of the Gram-negative to gentamicin was 53.8 percent and to streptomycin 30 percent. Most donors and recipients were men, the average time between death and enucleation was approximately 2 hours and preservation in solution with gentamicin and streptomycin was around 7 days. Neoplasms and more than one associated cause were the most frequently causes of death. Keratoconus was the main indication for transplant (51.7 percent). CONCLUSIONS: Coagulase-negative Staphylococcus was the most frequently isolated microorganism, presenting variable sensitivity to antimicrobians. The amount of corneas used for transplant was below the number of available corneas. Donor and receptor profiles were very heterogeneous regarding most of the analyzed variables.

Comparative study of cryopreserved bone tissue and tissue preserved in a 98% glycerol solution.

OBJECTIVE: To compare the bone graft cryopreservation method (at -80 degrees C) with a preservation method using a 98% glycerol solution at room temperature (10 degrees C-35 degrees C), by testing the antibacterial and fungal effects of 98% glycerol and comparatively analyzing the observed histological changes resulting from the use of both methods. METHOD: This study was of 30 samples of trabecular bone tissue from 10 patients undergoing total hip arthroplasty. Each femoral head provided 3 samples that were randomized into 3 groups, namely, the control group, the cryopreserved group, and the group preserved in a 98% glycerol at room temperature for 1 year. The samples were submitted to histomorphologic, cell feasibility, and microbiologic analyses. The results were statistically analyzed using the McNemar test, with a statistical significance index of 0.05. RESULTS: Values obtained using the McNemar test to compare probability distributions of histomorphologic variables (mature or lamellar bone, immature bone, and necrosis) and cell feasibility (osteoblasts and osteoclasts) indicated that there is no difference between the distributions of variables under the 3 experimental conditions. Microbiological analysis of the 98% glycerol solution and bone fragments from samples stored for 1 year at room temperature did not show bacterial or fungal growth. The histological and microbiological investigation were performed at 2 different time points: immediately after the sample processing and after 1 year. CONCLUSION: The method used to preserve bone grafts kept in 98% glycerol at room temperature (10 degrees C-35 degrees C) was similar to cryopreservation in terms of bone matrix preservation; no bacteria or fungi were found in the samples.

Comparative study of cryopreserved bone tissue and tissue preserved in a 98 percent glycerol solution / Estudo comparativo entre o tecido ósseo criopreservado e o conservado em glicerol a 98 por cento

OBJECTIVE: To compare the bone graft cryopreservation method (at -80°C) with a preservation method using a 98 percent glycerol solution at room temperature (10°C-35°C), by testing the antibacterial and fungal effects of 98 percent glycerol and comparatively analyzing the observed histological changes resulting from the use of both methods. METHOD: This study was of 30 samples of trabecular bone tissue from 10 patients undergoing total hip arthroplasty. Each femoral head provided 3 samples that were randomized into 3 groups, namely, the control group, the cryopreserved group, and the group preserved in a 98 percent glycerol at room temperature for 1 year. The samples were submitted to histomorphologic, cell feasibility, and microbiologic analyses. The results were statistically analyzed using the McNemar test, with a statistical significance index of 0.05. RESULTS: Values obtained using the McNemar test to compare probability distributions of histomorphologic variables (mature or lamellar bone, immature bone, and necrosis) and cell feasibility (osteoblasts and osteoclasts) indicated that there is no difference between the distributions of variables under the 3 experimental conditions. Microbiological analysis of the 98 percent glycerol solution and bone fragments from samples stored for 1 year at room temperature did not show bacterial or fungal growth. The histological and microbiological investigation were performed at 2 different time points: immediately after the sample processing and after 1 year. CONCLUSION: The method used to preserve bone grafts kept in 98 percent glycerol at room temperature (10°C-35°C) was similar to cryopreservation in terms of bone matrix preservation; no bacteria or fungi were found in the samples.

OBJETIVO: Comparar o método da criopreservação de enxertos ósseos (- 80° C) com o da conservação em glicerol a 98 por cento em temperatura ambiente (10° C a 35° C), testando os efeitos antibacterianos e antifúngicos do glicerol a 98 por cento e analisando comparativamente as alterações histológicas verificadas e decorrentes do emprego dos dois métodos. MÉTODO: Este estudo foi constituído de 30 amostras de tecido ósseo trabecular provenientes de 10 pacientes, submetidos a Artroplastia Total do Quadril. Cada cabeça femoral forneceu 3 amostras e estas foram divididas aleatoriamente em 3 grupos, a saber: controle, criopreservado e conservado em glicerol a 98 por cento à temperatura ambiente durante um ano. As amostras foram encaminhadas à Anatomia Patológica para estudo histomorfologico, de viabilidade celular, e microbiológico. Os resultados foram analisados estatisticamente pelo método de McNemar, com índice de significância de 0,05. RESULTADOS: A análise dos valores obtidos no teste de McNemar na comparação das distribuições de probabilidades das variáveis da histomorfologia (osso maduro ou lamelar, osso imaturo e necrose) e da viabilidade celular (osteoblastos e osteoclastos) indica não haver diferença entre as distribuições das variáveis nas três condições experimentais. A análise microbiológica da solução de glicerol a 98 por cento e dos fragmentos ósseos das amostras armazenadas durante um ano em temperatura ambiente não apresentou crescimento bacteriano ou de fungos. As espécimens do grupo controle foram analisadas histológica e microbiologicamente logo após a coleta das mesmas. CONCLUSÃO: O método de conservação de enxertos ósseos mantidos no glicerol a 98 por cento em temperatura ambiente (10°C a 35°C) foi similar ao da criopreservação quanto à preservação da matriz óssea e à ausência de crescimento de bactérias ou fungos.

Recomendaciones para el estudio microbiológico de tejidos preservados para implantes / Recommendations for the microbiological study of tissues preserved for implants

El uso de los implantes de tejido en medicina ha mejorado el pronóstico y/o la calidad de vida de muchas enfermedades, sin embargo, su utilización no está exenta de riesgos para el receptor. Es por esto que la cuidadosa selección del donante vivo o cadáver y el control microbiológico de los tejidos antes de su utilización son procesos muy importantes para asegurar la calidad del procedimiento. La contaminación de los tejidos puede ser intrínseca (por una infección no diagnosticada en el donante) o extrínseca (una vez que el tejido ya ha sido procurado). Estas recomendaciones se refieren al control microbiológico de las contaminaciones extrínsecas, ya sea durante la manipulación, durante la obtención de los tejidos o durante el procesamiento para la preservación de ellos. Se analizan los implantes de uso más frecuente en nuestro país (válvulas cardíacas, tejido óseo, piel, células progenitoras hematopoyéticas y córnea) y se describe la metodología según datos existentes en la literatura y de procedimientos adaptados de centros foráneos. Dado que ningún implante es absolutamente estéril es muy importante analizar también las recomendaciones frente a cultivos contaminados. Los autores esperamos que este documento sea de utilidad y que en un futuro próximo, podamos exhibir cifras nacionales multicéntricas con metodologías comparables.

Effect of coconut water and Braun-Collins solutions at different temperatures and incubation times on the morphology of goat preantral follicles preserved in vitro.

Preservation of preantral follicles becomes very important to ensure follicle quality at the onset of cryopreservation or in vitro culture. However, for domestic animals, the ovarian donor of preantral follicles for in vitro studies is commonly encountered far away from reproduction laboratories. We investigated the effectiveness of coconut water and Braun-Collins solutions on the preservation of goat preantral follicles. At the slaughterhouse, the ovarian pair of each animal was divided into 19 fragments. One ovarian fragment was immediately fixed (Control - Time 0). The other 18 fragments were randomly distributed into tubes containing 2 mL of coconut water or Braun-Collins solution at 4 degrees, 20 degrees or 39 degrees C and then stored for 4, 12 or 24 h. Histological analysis showed that the storage of ovarian fragments in coconut water and Braun-Collins solutions at 20 degrees or 39 degrees C for 12 or 24 h significantly reduced (P < 0.05) the percentage of morphologically normal preantral follicles when compared with the control. However, storage in coconut water at 20 degrees C for 4 h and in both solutions at 4 degrees C kept the percentage at control values. Ultrastructural analysis of follicles exposed to the stated conditions confirmed the integrity of preantral follicles stored at 4 degrees C in Braun-Collins and coconut water solutions for up to 12 and 24 h, respectively. Reduced cellular metabolism at 4 degrees C may explain why the best preservation of preantral follicles was at 4 degrees C, which may suggest a useful method for ovary transport in the future.

Trasplante cardíaco: experiencia inicial / Cardiac transplantation: experience inicial

Se presenta la experiencia inicial de 7 trasplantes cardíacos efectuados en un centro privado de la Ciudad de Rosario. Se describen la indicación etiológica, las técnicas empleadas y se analizan sus resultados. Se destaca la importancia del apoyo institucional necesario para este emprendimiento, así como las dificultades inherentes al medio nacional

Trasplante cardíaco: experiencia inicial / Cardiac transplantation: experience inicial

Se presenta la experiencia inicial de 7 trasplantes cardíacos efectuados en un centro privado de la Ciudad de Rosario. Se describen la indicación etiológica, las técnicas empleadas y se analizan sus resultados. Se destaca la importancia del apoyo institucional necesario para este emprendimiento, así como las dificultades inherentes al medio nacional