The impact of synthetic bone grafting for tissue regeneration: an in vivo study

Aims: This study aimed to examine the biological response of synthetic nanocomposite material on canine mandibular bone. Methods: Nine healthy adult male local breed dogs aged 12 to 18 months and weighing 10.2 to 15.2 kg were used in the study. Based on healing intervals of 1 and 2 months, the dogs were divided into 2 groups. Each group had 3 subgroups with 3 dogs each. The division was based on the grafting material used to fill the created defect: an empty defect (Control-ve), Beta-Tricalcium Phosphate, and nanocomposite (Beta-Tricalcium Phosphate and nanosilver 1%) . Surgery started after the dogs were anaesthetized. The surgical procedure began with a 5 cm parallel incision along the mandible's lower posterior border. After exposing the periosteum, a three 5mm-diameter, 5-mmdeep critical-size holes were made, 5mm between each one. Each group's grafting material had independent 3 holes. The defects were covered with resorbable collagen membranes followed by suturing of the mucoperiosteal flap. Results: Total densitometric analysis showed no significant differences between groups at 1-month intervals, with the nanocomposite group having a higher mean rank (165.66± 31.21) in comparison to other groups while at 2 months intervals that there was a highly significant difference between three groups as the P-value was (0.000) with the nanocomposite group having a higher mean rank (460.66± 26.40). Conclusions: In the current study, the use of nanocomposites improved osteoconductivity by accelerating new bone formation. Moreover, the encorporation of nanosilver enhanced growth factor activity. These attributes make nanocomposites a promising material for enhancing the bone healing process

Descelularización y regeneración de tráquea porcina: un acercamiento a la ingeniería tisular / Decellularization and Regeneration of Porcine Trachea: an Approach to Tissue Engineering

Resumen Antecedentes: la ingeniería tisular permite obtener órganos como injertos a partir de tejidos descelularizados, regenerados con células autólogas. Objetivo: descelularizar y regenerar tráqueas porcinas. Material y métodos: se descelularizaron tráqueas porcinas colocándolas cada una en el epiplón de cuatro cerdos Yorkshire para su regeneración in vivo. Una tráquea desce-lularizada con tritón (DT), descelularizada con desoxicolato (DD), descelularizada con desoxicolato y reforzada con un polímero y células epiteliales (DDR), y una nativa crio-preservada (NC). Después de 8 días se obtuvieron la DD, NC y DDR; y al día 15, la DT. Se las evaluó mecánica e histológicamente, se realizó el análisis casuístico. Resultados: las tráqueas descelularizadas conservaron la integridad del cartílago, sin diferencias mecánicas, excepto la DDR con mayor rigidez. Las tráqueas regeneradas presentaron menor rigidez, excepto la DDR que además perdió el epitelio y la vascula-ridad. Las DT, DD mostraron epitelio no respiratorio, fibrosis y vasculogénesis con in-flamación. Conclusiones: las matrices conservaron sus características mecánicas. La regenera-ción in vivo ofrece ventajas como la esterilidad, interacción celular, nutrientes; es senci-llo, factible y económico, pero no hay control del crecimiento celular y vascularización, y los tejidos presentaron alteraciones mecánicas e histológicas. El polímero impidió la re-epitelialización y revascularización. Este estudio abre la posibilidad de mejorar las me-todologías de ingeniería tisular aplicadas al tejido traqueal.

Abstract Introduction: tissue engineering makes it possible to obtain organs as grafts from de-cellularized tissues, regenerated with autologous cells.Objective: decellularize and regenerate porcine tracheas.ARTÍCULO ORIGINAL | Respirar, 2023; 15(3): 188-199 | ISSN 2953-3414 | https://doi.org/10.55720/respirar.15.3.5RECIBIDO: 9 agosto 2023ACEP TADO: 31 agosto 2023 Elisa Barrera-Ramírezhttps://orcid.org/0000-0002-2778-0882Rubén Efraín Garrido-Cardonahttps://orcid.org/0000-0001-6083-5403Alejandro Martínez-Martínezhttps://orcid.org/0000-0003-3448-910XLuis Fernando Plenge-Tellecheahttps://orcid.org/0000-0002-1619-5004Edna Rico-Escobarhttps://orcid.org/0000-0002-0933-0220Esta revista está bajo una licencia de Creative Commons Reconocimiento 4.0 Internacional. Respirar 2023; 15 (3): 189ARTÍCULO ORIGINAL / E. Barrera-Ramírez, R.E. Garrido-Cardona, A. Martínez-Martínez, L.F. Plenge-Tellechea, E. Rico-EscobarDescelularización y regeneración de tráqueaISSN 2953-3414Materials and Methods: Porcine tracheas were decellularized by placing each one in the omentum of four Yorkshire pigs for regeneration in vivo. A trachea decellularized with triton (DT), decellularized with deoxycholate (DD), decellularized with deoxycho-late and reinforced with a polymer, and epithelial cells (DDR), and a cryopreserved na-tive (NC). After 8 days, the DD, NC and DDR were obtained; and on day 15, the DT. The evaluation was mechanically and histologically, performing the case analysis.Results: the decellularized tracheas preserved the integrity of the cartilage, with no me-chanical differences, except for the DDR with greater rigidity. The regenerated trache-as presented less rigidity, except the DDR, which also lost the epithelium and vascular-ity. The DT, DD showed non-respiratory epithelium, fibrosis and vasculogenesis with inflammation.Conclusions: the matrices retained their mechanical characteristics, in vivo regenera-tion offers advantages such as sterility, cell interaction, nutrients; it is simple, feasible and economical, but there is no control of cell growth and vascularization, and the tis-sues presented mechanical and histological alterations. The polymer prevented re-epi-thelialization and revascularization. This study opens the possibility of improving tissue engineering methodologies applied to tracheal tissue.

Socket regeneration after immediate loading implants with tissue and bone graft: 1-year clinical follow-up

Evaluation of ridge alteration after 1 year follow up after immediate loading implant placement. Methods: Ten patients were included in the study, in whom the ridge volume, height, and thickness were evaluated from region of interest (ROI) of tomographic images of the operated areas (test group) and compared to the opposite tooth (control group). Results: After one year, there was no implant loss and all patients were satisfied with the treatment. In the test group there was a statistically significant increase in ridge height (2.89±1.05 mm) when compared to the control group. No significant difference in relation to ridge volume and thickness was observed. In the intragroup evaluation, a significant gain in ridge height (2.65±3.08 mm) was observed when compared to baseline. Conclusion: The placement of an immediate implant, temporary crown, and tissue regeneration in sockets with buccal defects promotes the regeneration of the buccal wall while preventing the reduction of bone volume and thickness

Treatment of Muscle Injury with Stem Cells - Experimental Study in Rabbits / Tratamento da lesão muscular com células-tronco - Estudo experimental em coelhos

Abstract Objective Histological and macroscopic evaluation of the healing process of acute lesions of the femoral rectus muscle using stem cells derived from adipose tissue-derived stem cells (ADSCs). Method An experimental study was conducted with 18 hind legs of New Zealand rabbits, which were divided into three study groups according to the intervention to be performed. In group I, no surgical procedure was performed; in group II—SHAN, the experimental lesion was performed without any additional intervention protocol; in group III—Intervention, the addition of ADSCs was performed in the same topography of the experimental lesion. After the proposed period, 2 weeks, the material was collected and submitted to macroscopic and histological evaluation. Results The quantitative analysis showed that the addition of ADSCs is related to the reduction of inflammatory cells in the 2-week evaluation (164.2 cells in group II - SHAN to 89.62 cells in group III - ADSC). The qualitative analysis of the slides with Picrosirius red, noticed an increase in orange/yellow fibers in group III - ADSC, which evidences a final healing process. The macroscopic evaluation found no difference between the groups. Conclusion The use of ADSCs in the treatment of acute muscle injury presented histological advantages when compared to their non-use.

Resumo Objetivo Avaliação histológica e macroscópica do processo de cicatrização das lesões agudas do músculo reto femoral, com utilização de células-tronco derivadas de tecido adiposo (ADSCs, na sigla em inglês). Método Foi realizado um estudo experimental com 18 patas traseiras de coelhos Nova Zelândia, que foram divididos em três nos grupos de estudo de acordo com a intervenção a ser realizada. No grupo I não foi realizado procedimento cirúrgico; no grupo II - SHAN foi realizado a lesão experimental sem nenhum protocolo de intervenção adicional; e no grupo III - Intervenção foi realizado a adição de ADSCs na mesma topografia onde foi realizada a lesão experimental. Após o período proposto, 2 semanas, o material foi coletado, submetido a avaliação macroscópica e histológica. Resultados A análise quantitativa demonstrou que a adição de ADSCs está relacionada com a diminuição de células inflamatórias na avaliação com 2 semanas (164,2 células no grupo II - SHAN para 89,62 células no grupo III - ADSC). A análise qualitativa das lâminas coradas com Picrosírius red demonstrou um aumento das fibras de cor laranja/amarela no grupo III - ADSC, o que evidencia um processo final de cicatrização. A avaliação macroscópica não encontrou diferença entre os grupos. Conclusão A utilização de ADSCs no tratamento de lesão muscular aguda apresentou vantagens histológicas quando comparada a sua não utilização.

Células madre en odontología: nuevas perspectivas / Stem cells in dentistry: new perspectives

En el campo de la odontología, prevalecen actualmente alternativas terapéuticas con una filosofía conservadora. Sin embargo, con el advenimiento de los tratamientos con células madre (CM), se amplían las posibilidades terapéuticas, que buscan la combinación y el equilibrio entre la intervención tradicional y las posibilidades de reposición de estructuras anatómicas dañadas, a través de la regeneración de tejidos utilizando células madre o sus derivados (AU)

In the dentistry field, therapeutic alternatives with a conservative philosophy currently prevail. However, with the advent of stem cell (SC) treatments, therapeutic possibilities are expanding, seeking a combination and balance between traditional intervention and the pos- sibility of replacing damaged anatomical structures through tissue regeneration, using stem cells or their derivatives (AU)

Biochemical and histopathological evaluations of chronic renal failure rats treated with pluripotent human stem cells

Abstract Regeneration of damaged kidney cells using stem cells is the current research approach in the treatment of chronic renal failure (CRF). In the present study, the histopathological and biochemical techniques were used to evaluate stem cells' (SCs) role in treatment of CRF. Sixty-four rats were divided into eight groups. Group I (GI): rats were injected with doxorubicin (15 mg/kg) to initiate CRF. GII-GVII: rats were injected with doxorubicin and treated with SCs (1x106 MSCs or/and 2x104 HSCs/rat) with/without growth factors extract (200 µL/rat) and/or immunosuppressor (cyclosporine A, 5 mg/kg/day). GVIII: rats treated with PBS (100 µL/kg/day). Levels of creatinine, urea and uric acid were increased in rats sera after injection with doxorubicin, while blood electrolyte levels of Na, K, P and Mg were decreased. Also, histopathological abnormalities such as hyalinized blood vessels, degenerated hyalinized glomerulus tubules and cell debris in the lumen and degeneration of renal tissues were observed in these rats. After treatment with SCs, all these parameters restore their normal values with regeneration of the damaged cells as demonstrated in histopathology of the treated groups. It can be concluded that, the use of SCs in treatment of kidney diseases is a promising approach and needs more efforts.

Quantitative evaluation of the regenerated dura mater in a decompressive skull trepanation model in rats / Evaluación cuantitativa de la duramadre regenerada en un modelo de perforación cranial descompresiva en ratas

SUMMARY: Regeneration of the dura mater following duraplasty using a collagen film, a chitosan film, or a combination of both with gelatin, was studied in a craniotomy and penetrating brain injury model in rats. Collagen autofluorescence in the regenerated dura mater was evaluated using confocal microscopy with excitation at λem = 488 nm and λem = 543 nm. An increase in regeneration of the extracellular matrix of connective tissue and an increase in matrix fluorescence were detected at 6 weeks after duraplasty. The major contributors to dura mater regeneration were collagen films, chitosan plus gelatin-based films, and, to a much lesser extent, chitosan-based films. By using autofluorescence densitometry of extracellular matrix, the authors were able to quantify the degree of connective tissue regeneration in the dura mater following duraplasty.

RESUMEN: Se estudió la regeneración de la duramadre después de una duraplastía utilizando una lámina de colágeno, una lamina de quitosano o una combinación de ambas con gelatina en un modelo de craneotomía y lesión cerebral en ratas. La autofluorescencia del colágeno en la duramadre regenerada se evaluó mediante microscopía confocal con excitación a λem = 488 nm y λem = 543 nm. Se observó un aumento en la regeneración de la matriz extracelular del tejido conectivo y un aumento en la fluorescencia de la matriz a las 6 semanas después de la duraplastía. Se observe un efecto significativo en la regeneración de la duramadre con las láminas de colágeno, las láminas en base de quitosano más gelatina y, en un menor grado, las láminas a base de quitosano. Mediante el uso de densitometría de autofluorescencia de la matriz extracelular, los autores lograron cuantificar el grado de regenera- ción del tejido conectivo en la duramadre después de la duraplastía.

Reconstrucción de la fosa poplítea con colgajo fasciocutáneo de la arteria safena / Reconstruction of the popliteal fossa with fasciocutaneous flap of the saphenous artery

INTRODUCCIÓN. Los defectos de la fosa poplítea suponen un desafío reconstructivo para el cirujano plástico, dada la relación íntima de esta área con la articulación de la rodilla y la neurovasculatura vital subyacente. El propósito de éste informe fie compartir la experiencia en la utilización de un colgajo fasciocutaneode la arteria safena. CASO CLÍNICO. Paciente de 5 años de edad que sufrió quemadura térmica en miembros inferiores con dos años y medio de evolución, ameritó injertos, presentó contractura por tejido cicatricial en fosa poplítea, dificultó la deambulación y desarrollo neuro osteomuscular. Se realizó reconstrucción de la fosa poplítea con colgajo fasciocutáneo de la arteria safena. RESULTADOS. El colgajo fasciocutáneo de la arteria safena dio cobertura al defecto en fosa poplítea izquierda tras retiro del tejido cicatricial que producía contractura, limitaba la marcha y el desarrollo neuro osteo-muscular. Seis meses postquirúrgicos brindó cobertura cutánea definitiva y estable en el área crítica, que permitió la deambulación con movimientos de extensión y flexión de rodilla conservados. DISCUSIÓN. Este colgajo al igual que en otros estudios que respaldan su ejecución brindó excelentes resultados en defectos de partes blandas a nivel de la articulación de la rodilla. CONCLUSIÓN. El colgajo fasciocutáneo de la arteria safena demostró utilidad para la reconstrucción del defecto de la fosa poplítea, posibilitó una cobertura definitiva, funcional y estética, restableció los ángulos de movilidad y favoreció el desarrollo pondoestatural del paciente.

INTRODUCTION. Defects of the popliteal fossa pose a reconstructive challenge for the plastic surgeon, because of the intimate relation of this area with the knee joint and the near vital neurovasculature; the purpose of this report was to share the experience of using a fasciocutaneous flap of the saphenous artery. CLINICAL CASE. A 5 year old patient who suffered thermal burn in lower limbs with two and a half years of evolution, he nedeed grafts and presented tissue contracture because the scar in the popliteal fossa hindered ambulation and neuro-osteomuscular growth. Reconstruction of the popliteal fossa was made it with a fasciocutaneous flap of the saphenous artery. RESULTS. The fasciocutaneous flap of the saphenous artery covered the defect in the left popliteal fossa after removal of the scar tissue that caused contracture, limited to walk and growth. Six months after surgery the flap provided definitive and secure skin coverage in the critical area, which allowed to walk with preserved knee extension and flexion movements. DISCUSSION. This flap was useful for the recons-truction of the defect of the popliteal fossa and provided excellent results in soft tissue defects in this area of the knee joint. CONCLUSION. The fasciocutaneous flap of the saphenous artery proved useful for the reconstruction of the popliteal fossa defect, it permited a definitive, functional and esthetic coverage, reestablished the angles of mobility and helped with the patient growth

Alcance de las células madre derivadas de tejido adiposo / Scope of stem cells derived from adipose tissue

Introducción: En el tejido adiposo se han identificado células madre mesenquimales con capacidad autorrenovadora y multipotencial. Mediante digestión enzimática y centrifugado del lipoaspirado se libera una población heterogénea de células denominada fracción vascular estromal, con innumerables potencialidades terapéuticas en el campo de la medicina regenerativa. Objetivo: Actualizar el alcance de las células madre derivadas de tejido adiposo en la terapia regenerativa. Método: Se revisaron 38 artículos entre los años 2000 y 2019 en las bases de datos Scielo, ScienceDirect, Medline y Pubmed. Desarrollo: Las células de la fracción vascular estromal se caracterizan por su capacidad de generar tejido adiposo y vasos sanguíneos, y por la producción de factores de crecimiento que ayudan en la supervivencia de los adipocitos y la formación de una red vascular. El principal mecanismo de acción de las células madre derivadas de tejido adiposo parece deberse a su acción paracrina y a la sinergia con células endoteliales. En el campo de la medicina regenerativa se han utilizado en el tratamiento de cicatrices patológicas y de fibrosis deformantes con impotencia funcional, en las reconstrucciones de secuelas por cáncer y en el cierre precoz de zonas cruentas. Conclusiones: La lipotransferencia es un procedimiento con un mínimo de complicaciones que constituye una de las opciones terapéuticas más empleadas para corregir defectos en los tejidos, debido a que no solo es un medio de relleno, sino que también permite la regeneración y restauración tisular. La presencia de células madre en el tejido adiposo, unido a su accesibilidad, disponibilidad e histocompatibilidad, ha motivado su aplicación cada vez más expandida en la medicina estética, reconstructiva y regenerativa(AU)

Introduction: Mesenchymal stem cells with self-renewing and multipotential capacity have been identified in adipose tissue. By means of enzymatic digestion and centrifugation of the lipoaspirate a heterogeneous population of cells called vascular stromal fraction is released. It has innumerable therapeutic potentialities in the field of regenerative medicine. Objective: To update the scope of stem cells derived from adipose tissue in regenerative therapy. Method: 38 articles published between 2000 and 2019 in the Scielo, ScienceDirect, Medline and Pubmed databases were reviewed. Development: The cells of the vascular stromal fraction are characterized by generating adipose tissue and blood vessels and by the production of growth factors that help in the survival of adipocytes and the formation of a vascular network. The main mechanism of action of stem cells derived from adipose tissue appears to be due to their paracrine action and synergy with endothelial cells. Stem cells derived from adipose tissue have been used in regenerative medicine for the treatment of pathological scars and deforming fibrosis with functional impotence, in the reconstruction of cancer sequelae and in the early closure of bloody areas. Conclusions: Lipotransfer is a procedure with a minimum of complications that constitutes one of the most widely used therapeutic options to correct tissue defects, since it is not only a filling medium, but also allows tissue regeneration and restoration. The presence of stem cells in adipose tissue, together with their accessibility, availability and histocompatibility, has motivated their increasingly widespread application in aesthetic, reconstructive and regenerative medicine(AU)

Different techniques for the treatment of teeth with an incomplete root development and pulp necrosis: a systematic review / Diferentes técnicas para o tratamento de dentes com rizogênese incompleta e necrose pulpar: uma revisão sistemática

Introduction: The objective of this systematic review was to compare the apexification techniques of calcium hydroxide (Ca(OH)2), or mineral trioxide aggregate (MTA), with the pulp regeneration technique, using cohort studies, and non-randomized and randomized clinical trials. Methods: The methodology was based on electronic research in the following databases: PubMed, MEDLINE, Google Scholar, SciELO, and LILACS. In addition, a manual search was carried out using the references that were listed in the articles found. Results: A total of 403 potentially eligible studies were found, with seven being included in the inclusion criteria of this systematic review. The seven studies involved a total of 312 teeth. The minimum time of a follow-up period was 12 months. The irrigation solution most used was sodium hypochlorite, for both of the apexification and revascularization techniques. The medication commonly chosen in the apexification groups was Ca(OH)2, with antibiotic triple paste in the revascularization groups. The clinical rate of success in the groups treated with revascularization varied from 76% to 100%, while in the groups treated with apexification, it ranged from 68% to 100%. Only two studies reached a success rate equal to 100%. Conclusions: Variable levels of evidence were observed in relation to the treatments. However, it was confirmed that revascularization is an excellent option since its outcomes produced a greater gain of thickness and root length, besides developing a decrease in the apical foramen.

Introdução: O objetivo desta revisão sistemática foi comparar as técnicas de apexificação, com hidróxido de cálcio (Ca(OH)2) ou agregado trióxido mineral (MTA), com a técnica de regeneração pulpar, utilizando estudos coorte, ensaio clínico não randomizado e randomizado. Métodos: A metodologia foi baseada em pesquisa eletrônica nas seguintes bases de dados: PubMed, MEDLINE, Google Acadêmico, SciELO e LILACS. Além disso, foi realizada uma pesquisa manual utilizando as referências listadas nos artigos encontrados. Resultados: Foram encontrados 403 estudos potencialmente elegíveis, sendo sete incluídos nos critérios de inclusão desta revisão sistemática. Os sete estudos envolveram um total de 312 dentes. O tempo mínimo de um período de acompanhamento foi de 12 meses. A solução de irrigação mais utilizada foi o hipoclorito de sódio, para as técnicas de apexificação e revascularização. O medicamento comumente escolhido nos grupos de apexificação foi o Ca(OH)2, com pasta tripla antibiótica nos grupos de revascularização. A taxa clínica de sucesso nos grupos tratados com revascularização variou de 76% a 100%, enquanto nos grupos tratados com apexificação variou de 68% a 100%. Apenas dois estudos atingiram uma taxa de sucesso igual a 100%. Conclusões: Níveis variáveis de evidência foram observados em relação aos tratamentos. No entanto, confirmou-se que a revascularização é uma excelente opção, pois seus desfechos produzem maior ganho de espessura e comprimento radicular, além de diminuir o forame apical.

Banco de semillas de relaves mineros como indicador de recuperación de vegetación en Mariana, Brasil / Seed bank of mining tailings as indicator of vegetation regeneration in Mariana, Brazil

Resumen Introducción: El banco de semillas en el suelo es uno de los indicadores ecológicos más importantes para la evaluación y monitoreo de recuperación de ecosistemas degradados. Así mismo, actualmente indicadores ecológicos de restauración son usados en áreas afectadas por la ruptura de la represa de relaves de Fundão en Mariana, Minas Gerais, Brasil. Objetivo: En este estudio se evaluó la variación de la riqueza, composición de especies, densidad y parámetros fitosociológicos del banco de semillas en dos profundidades de relaves mineros en Mariana, municipio de Mariana, Minas Gerais, Brasil. Métodos: Se recolectaron 15 muestras por nivel de profundidad, en la capa superior (Profundidad1, P1 = 0-2.5 cm) y capa inferior (Profundidad2, P2 = 2.5-5.0 cm) del relave de minería para examinar el banco de semillas viable, que luego se colocó en un invernadero para la germinación. Posteriormente se contaron e identificaron semanalmente todos los individuos de cada especie durante un período de seis meses. Resultados: Se demostró que existe un banco de semillas en las capas superficiales de relaves mineros acumulados en las áreas afectadas de Mariana, con una marcada diferencia entre profundidades en términos de riqueza de especies y densidad de individuos. Se observó una mayor riqueza y número de individuos en P1, (1 165 semillas germinadas), pertenecientes a 18 familias y 47 especies, en comparación a P2 (197 individuos), pertenecientes a 12 familias y 23 especies. El banco de semillas de la capa P1 está influenciado por la lluvia de semillas del bosque cercano. Por otro lado, el banco de semillas de P2, puede ser característico de los relaves mineros. Conclusiones: El banco de semillas estudiado puede tener efectos positivos sobre la recuperación en el área de estudio, debido a la alta proporción de especies nativas, pioneras y anemocóricas típicas de etapas iniciales de sucesión secundaria.

Abstract Introduction: The soil seed bank is one of the most important ecological indicators for evaluating and monitoring the resilience of degraded ecosystems. Likewise, ecological restoration indicators are currently used in areas affected by the rupture of the Fundão tailings dam in Mariana, Minas Gerais, Brazil. Objective: To evaluate the seed bank at two depths of areas affected by mining tailings, Mariana municipality, Minas Gerais, Brazil. Methods: 15 samples (40 × 40 cm) were collected per level of depth, in the upper layer (Depth1, P1 = 0-2.5 cm), and lower layer (Depth2, P2 = 2.5-5.0 cm) of the mining tailings to survey the viable seed bank, which was later placed in a greenhouse for germination and seedling identification. The samples were placed in plastic trays to germinate in the nursery, then counted and identified weekly for six months. Results: The results showed that there is a seed bank in the surface layers of accumulated mining tailings in the affected areas of Mariana, with a marked difference between depths in terms of species richness and density of individuals. Higher species richness and number of individuals were observed in P1, (1 165 germinated seeds), belonging to 18 families and 47 species, in comparison to P2 (197 individuals), belonging to 12 families and 23 species. Probably the seed bank of layer P1 is influenced by the rain of seeds from the nearby forest. On the other hand, the P2 seed bank can be characteristic of mining tailings. Conclusions: Seed bank patterns can have positive effects on forest resilience at the local-scale, due to the high proportion of native, pioneer and anemochorical species of early successional stages.

Regeneración de un bosque secundario afectado por el Huracán Otto en Costa Rica / Regeneration of a secondary forest affected by Hurricane Otto in Costa Rica

Resumen Introducción: Se han realizado múltiples estudios en bosques afectados por huracanes, pero la información obtenida para Costa Rica es escasa, o nula en el caso de impactos directos como lo fue Otto, por lo que es necesario ampliar el conocimiento que se tiene acerca de los efectos de estos fenómenos en bosques tropicales y los mecanismos de recuperación de estos biomas. Consecuentemente se vuelve necesario identificar la vulnerabilidad de los ecosistemas a largo plazo y cuantificar las pérdidas que se generan a diferentes escalas, producto de los intensos eventos pluviales y los fuertes vientos. Objetivo: Determinar el comportamiento y estado de la recuperación en un bosque secundario afectado directamente por el huracán Otto en Boca Tapada, Pital, San Carlos, Costa Rica. Métodos: Se establecieron 10 unidades de muestreo de 20 x 50 m distribuidas de forma sistemática dentro de un bosque secundario afectado por el huracán Otto en Boca Tapada de San Carlos. Se evaluó la condición actual del bosque, se identificaron las especies que más daño recibieron por consecuencia de los fuertes vientos, así como las que poseen capacidad de recuperarse a través de rebrotes. Se realizó un sobrevuelo con un vehículo no tripulado, y se construyó un ortomosaico que fue posteriormente digitalizado y clasificado de acuerdo con el estado de la cobertura forestal presente en tres tiempos evaluados, condición inicial, después del aprovechamiento forestal y la condición al momento de realizado el muestreo. Se comparó la densidad poblacional, diversidad y área basal con lo presentado para un bosque primario aledaño al sitio de estudio, que también fue afectado por el paso del huracán Otto. Resultados: Se obtuvo que un 69.5 % de los individuos con d ≥ 5 cm se encuentran en buen estado, un 20.3 % fue descopado y un 12.7 % inclinado sin exposición de raíces. La familia que más riqueza de especies aporta es Fabaceae, esta misma es la que más abundancia de individuos dañados posee y la que presentó mayor cantidad de especies con capacidad de rebrotar. La especie que más daños sufrió fue Couma macrocarpa (Euphorbiaceae). El área de cobertura boscosa inicial fue afectada en un 7,63 % por el aprovechamiento forestal, y en un 44.25 % por el paso del huracán Otto. Se determinó que existen diferencias significativas en la diversidad de especies (P = 0.0004; α = 0.05) y en la densidad de individuos (P = 0.0011; α = 0.05), el bosque secundario es quien posee la mayor media. No se presentaron diferencias significativas en los valores de área basal (P = 0.6951; α = 0.05). Conclusiones: Un 30,5 % de la masa forestal fue afectada por el paso del huracán Otto y la familia Fabaceae representa un papel importante en la recuperación del bosque. Además, el aprovechamiento forestal en un bosque puede aumentar el riesgo de afectación por el paso de huracanes y el bosque secundario posee mayor diversidad de especies y mayor densidad de individuos que el bosque primario.

Abstract Introduction: Multiple studies have been carried out in forests affected by hurricanes, but the information obtained for Costa Rica is scarce or null, in the case of direct impacts such as Otto, so it is necessary to expand the existing knowledge about the effects of these phenomena on tropical forests and the recovery mechanisms of these biomes. Consequently, it is necessary to identify the vulnerability of ecosystems in long term and quantify the losses that are generated at different scales, as a result of the intense events of rain and strong winds. Objective: Determining behavior and recovery status in a secondary forest directly affected by Hurricane Otto in Boca Tapada, Pital, San Carlos, Costa Rica. Methods: Ten 20 x 50 m sampling units were systematically distributed within a secondary forest affected by Hurricane Otto in Boca Tapada, San Carlos. The current condition of the forest was evaluated, the species that received the most damage due to high winds were identified, as well as those that have the capacity to recover through regrowths. An overflight was carried out with an unmanned aerial vehicle and an orthomosaic was constructed, subsequently digitized, and classified according to the state of the forest cover presented in three evaluated moments, initial condition, after logging and the condition at the time of sampling. Population density, diversity, and basal area, were compared to data obtained in an adjacent primary forest also affected by the passage of Hurricane Otto. Results: It was obtained that 69.5 % of individuals with d ≥ 5 cm are in good condition, 20.3 % were broken in the tree canopy and 12.7% inclined without exposure of the roots. The family that provided the greatest species richness is Fabaceae, which is the same with the greatest abundance of damaged individuals and the one with the highest number of species with the ability to resprouting. The species that suffered the most damage was Couma macrocarpa (Euphorbiaceae). The initial area of forest cover was reduced by 7.63 % due to logging and 44.25 % due to Hurricane Otto. It was determined that there are significant differences in species diversity (P = 0.0004; α = 0.05) and in the density of individuals (P = 0.0011; α = 0.05). The secondary forest has the highest average in both cases. There are no significant differences in the values of the basal area (P = 0.6951; α = 0.05). Conclusions: 30.5 % of the forest mass was affected by the passage of Hurricane Otto and the Fabaceae family plays an important role in forest recovery. In addition, forest harvesting in a forest can increase the risk of being affected by the passage of hurricanes and the secondary forest has a greater diversity of species and a higher density of individuals than the primary forest.

Combined periodontal regeneration of molar severely compromised by furcation, intrabony defects and attachment loss to the apex: a case report / Regeneración periodontal combinada de molar gravemente comprometido por furcación, defectos intraóseos y pérdida de inserción en el ápice: reporte de un caso

Introduction: Clinicians tend to encounter unfavorable situations in the treatment of teeth with severe attachment loss. Periodontal regeneration has been a successful therapeutic approach in treatments that require a long-term prognosis improvement. This case shows the benefits of combined regenerative periodontal therapy in a patient with a molar severely compromised by furcation, intrabony defects and attachment loss to the apex. Case Report: The clinical case included an endo-periodontal, class III furcation and intrabony defects in a generalized periodontitis, Stage III Grade C patient. After non-surgical periodontal treatment and re-evaluation, a full-thickness flap and surgical debridement were performed. Dental root surface was treated with EDTA and enamel matrix derivatives and the defects were filled with allograft and platelet-rich fibrin, additionally a collagen membrane was applied over the graft. After a 12-month follow-up there was a resolution of the intrabony defects and periodontal regeneration. Clinical and radiographic evaluation also showed the partial resolution of the class III furcation defect. Conclusion: Combined periodontal regeneration can be a therapeutic approach to improve the prognosis and prevent the extraction of molars severely compromised by furcation, intrabony defects and attachment loss to the apex.

Introducción: Los clínicos tienden a encontrar situaciones desfavorables en el tratamiento de dientes por pérdida de inserción severa. La regeneración periodontal ha sido un enfoque terapéutico exitoso en tratamientos que requieren una mejora del pronóstico a largo plazo. Este caso demuestra los beneficios de la terapia periodontal regenerativa combinada en un paciente con un molar gravemente comprometido por furcación, defectos intraóseos y por pérdida de inserción hasta el ápice. Reporte de caso: El caso clínico incluyó un defecto endoperiodontal, furcación clase III y defectos intraóseos en una Periodontitis estadio III generalizada grado C. Tras el tratamiento periodontal no quirúrgico y la reevaluación, se realizó un colgajo de espesor total y un desbridamiento quirúrgico. La superficie de la raíz dental se trató con EDTA y derivados de la matriz de esmalte y los defectos se rellenaron con aloinjerto y fibrina rica en plaquetas, adicionalmente se aplicó una membrana de colágeno sobre el injerto. Después de un seguimiento de 12 meses hubo resolución de los defectos intraóseos y regeneración periodontal. La evaluación clínica y radiográfica también mostró la resolución parcial del defecto de furcación de clase III. Conclusión: La regeneración periodontal combinada puede ser un abordaje terapéutico para mejorar el pronóstico y prevenir la extracción de molares severamente comprometidos por furcación, por defectos y hasta el ápice.

Biological and physico-mechanical properties of poly (methyl methacrylate) enriched with graphene oxide as a potential biomaterial / Propiedades físicas-mecánicas-biológicas del poli (metilmetacrilato) enriquecido con óxido de grafeno como potencial biomaterial

Objective: To determine the cytotoxicity and effects of graphene oxide (GO) on cellular proliferation of gingival-fibroblasts, pulp-dental cells and human osteoblasts in culture, and to determine the physical, mechanical and biological properties of poly (methyl methacrylate) (PMMA) enriched with GO. Material and Methods: The GO was characterized with SEM. Cytotoxicity and cell proliferation were determined by the MTT bioassay. The physical mechanical tests (flexural strength and elastic modulus) were carried out with a universal testing machine. Sorption and solubility were determined by weighing before and after drying and immersion in water. Porosity was evaluated by visual inspection. Data were analyzed with Student's t-test and Tukey's posthoc ANOVA. Results: The GO has a heterogeneous morphology and a particle size of 66.67±64.76 µm. GO has a slight to no-cytotoxicity (>50-75% viability) at 1-30 days, and at 24 hours incubation of PMMA with GO significantly stimulates osteoblasts (45±8%, p<0.01). The physical and mechanical properties of PMMA with GO increase considerably without altering sorption, solubility and porosity. Conclusion: GO alone or with PMMA has an acceptable biocompatibility, could contribute to cell proliferation, cell regeneration and improve the physical mechanical properties of PMMA.

Objective: To determine the cytotoxicity and effects of graphene oxide (GO) on cellular proliferation of gingival-fibroblasts, pulpdental cells and human osteoblasts in culture, and to determine the physical, mechanical and biological properties of poly (methyl methacrylate) (PMMA) enriched with GO. Material and Methods: T he G O w as c haracterized with SEM. Cytotoxicity and cell proliferation were determined by the MTT bioassay. The physical-mechanical tests (flexural strength and elastic modulus) were carried out with a universal testing machine. Sorption and solubility were determined by weighing before and after drying and immersion in water. Porosity was evaluated by visual inspection. Data were analyzed with Student's t-test and Tukey's post-hoc ANOVA. Results: The GO has a heterogeneous morphology and a particle size of 66.67±64.76 ?m. GO has a slight to no-cytotoxicity (>50-75% viability) at 1-30 days, and at 24 hours incubation of PMMA with GO significantly stimulates osteoblasts (45±8%, p<0.01). The physical and mechanical properties of PMMA with GO increase considerably without altering sorption, solubility and porosity. Conclusion: GO alone or with PMMA has an acceptable biocompatibility, could contribute to cell proliferation, cell regeneration and improve the physical-mechanical properties of PMMA.

Papila Apical Dentaria como fuente de Células Madre: Relato del Caso / Papila Apical Dentária como Fonte de Células Tronco: Relato de Caso / Dental Apical Papila Stem Cell: Case Report

Las células madre mesenquimales (MSCs) son células madre adultas que tienen la capacidad de diferenciarse en varios tipos de células. Una rica fuente de células madre mesenquimales puede ser obtenida de tejidos dentales como la papila apical. El objetivo de este trabajo fue extraer las células madre de la papila apical de terceros molares humano para mirar su viabilidad de usarse en la práctica clínica. La de separación celular con Stro-1 y estudio de cinéticas fueron realizados. Como resultado, esas células, presentaron alta tasa de proliferación, formación de colonias y fácil acceso. Concluimos que el uso de células madre obtenidas de diente puede ser una buena alternativa por ser de fácil acceso, alta viabilidad celular y expresión positiva para marcadores celulares mesenquimales. La regeneración tisular o la formación de estructuras craneofaciales constituyen el futuro de la medicina regenerativa, ofreciendo una posibilidad para el tratamiento de malformaciones congénitas, traumas y otras enfermedades.

As células tronco mesenquimais (CTMs) são células-tronco adultas que têm a capacidade de diferenciar em vários tipos de células. Uma rica fonte de células tronco mesenquimais pode ser obtida de tecidos dentais como a papila apical. O objetivo deste trabalho foi extrair as células tronco da papila apical de terceiros molares humano para ver sua viabilidade de ser usado na prática clinica. Teste separação celular com Stro-1 e estudo de cinéticas foram realizados. Como resultado essas células apresentaram alta taxa de proliferação, formação de colônias e de fácil acesso. Concluímos que o uso de células tronco obtidas de dente pode ser uma boa alternativa por ser fácil acesso, alta viabilidade celular e expressão positiva para marcadores celulares mesenquimais. A regeneração tecidual ou a formação de novo de estruturas craniofaciais é o futuro da medicina regenerativa, oferecendo uma possibilidade para tratamento de malformações congênitas, traumas e outras doenças.

Mesenchymal stem cells (MSCs) are adult stem cells that have the ability to diffe-rentiate into various cell types. A rich source of mesenchymal stem cells can be obtained from dental tissues such as the apical papilla. The objective of this work was to extract stem cells from the apical papilla of third human molars to see its feasibility to be used in clinical practice. Testing of cell separation with Stro-1 and study of kinetics were performed. As a result, these cells had a high rate of pro-liferation, formation of colonies and easy access. We conclude that the use of stem cells obtained from teeth can be a good alternative because they are easy to ac-cess, high cell viability and positive ex-pression for mesenchymal cell markers. Tissue regeneration or new formation of craniofacial structures is the future of re-generative medicine, offering a possibili-ty for treatment of congenital malforma-tions, traumas and other diseases.

Focus on periodontal engineering by 3D printing technology ­ a systematic review / Enfoque en la ingeniería periodontal mediante la tecnología de impresión 3D: una revisión sistemática

Three-dimensional (3D) bioprinting of cells is an emerging area of research but has not been explored yet in the context of periodontal tissue engineering. Objetive: This study reports on the optimization of the 3D bioprinting scaffolds and tissues used that could be applied clinically to seniors for the regenerative purpose to meet individual patient treatment needs. Material and Methods: We methodically explored the printability of various tissues (dentin pulp stem/progenitor cells, periodontal ligament stem/progenitor cells, alveolar bone stem/progenitor cells, advanced platelet-rich fibrin and injected platelet-rich fibrin) and scaffolds using 3D printers pertaining only to periodontal defects. The influence of different printing parameters with the help of scaffold to promote periodontal regeneration and to replace the lost structure has been evaluated. Results: This systematic evaluation enabled the selection of the most suited printing conditions for achieving high printing resolution, dimensional stability, and cell viability for 3D bioprinting of periodontal ligament cells. Conclusion: The optimized bioprinting system is the first step towards the reproducible manufacturing of cell laden, space maintaining scaffolds for the treatment of periodontal lesions.

La bioimpresión tridimensional (3D) de células es un área emergente de investigación, pero aún no se ha explorado en el contexto de la ingeniería de tejidos periodontales. Objetivo: Este estudio informa sobre la optimización de los tejidos y andamios de bioimpresión 3D utilizados que podrían aplicarse a personas mayores en el entorno clínico con fines regenerativos para satisfacer las necesidades de tratamiento de cada paciente. Material y Métodos: Exploramos metódicamente la capacidad de impresión de varios tejidos (células madre / progenitoras de la pulpa de dentina, células madre / progenitoras del ligamento periodontal, células madre / progenitoras de hueso alveolar, fibrina rica en plaquetas avanzada y fibrina rica en plaquetas inyectada) y andamios utilizando impresoras 3D que pertenecen solo a defectos periodontales. Se ha evaluado la influencia de diferentes parámetros de impresión con la ayuda de andamios para promover la regeneración periodontal y reemplazar la estructura perdida. Resultados: Esta evaluación sistemática permitió la selección de las condiciones de impresión más adecuadas para lograr una alta resolución de impresión, estabilidad dimensional y viabilidad celular para la bioimpresión 3D de células del ligamento periodontal. Conclusión: El sistema de bioimpresión optimizado es el primer paso hacia la fabricación reproducible de andamios de mantenimiento de espacio cargados de células para el tratamiento de lesiones periodontales

Improving micropropagation of some grape cultivars via boron, calcium and phosphate

BACKGROUND: An efficient regeneration protocol is a priority for the successful application of plant biotechnology. Grape nodal explants were used to develop a micropropagation protocol for Thompson Seedless and Taify cvs. Explants were cultured on MS medium supplemented with Kinetin or benzylaminopurine (BA) and indolebutyric acid (IBA). RESULTS: For both cultivars, axillary buds were grown, only, on a medium enriched with kinetin, moreover, shoot tip necrosis and callus formation were observed on Thompson Seedless cv. cultures grown on a medium with BA. Supplementing the growth medium with 100 mM (boron) B and 2.5 mM (calcium) Ca successfully help overcome these phenomena. The highest regenerated shoot numbers (14 and 6.2 explant 1 ) for Taify and Thompson Seedless cvs., respectively, were on media supplemented with 13.2 mM BA + 4.9 mM IBA and BA 13.2 mM + 5.8 mM IBA, respectively. Moreover, these media supported the developing shoots to have the heaviest dry weights (1.46 and 0.72 mg explant 1 ) for Taify and Thompson Seedless cvs., respectively. Thompson Seedless cv. regenerated shoot numbers and their dry weights were significantly increased by increasing the MS medium PO4 concentration. However, these two parameters were significantly decreased for Taify cv. Developing shoots were elongated and rooted on MS medium enriched with 4.9 mM, IBA 100 mM B and 2.5 mM Ca. Plantlets were acclimatized and successfully transferred to the greenhouse conditions. CONCLUSIONS: A novel promising protocol for Thomson Seedless and Taify cvs. micropropagation using single nodes has been developed.

A double fluorescence chimeric limb regeneration model reveals muscle fiber reconnection during axolotl limb regeneration / Modelo de regeneración quimérica de doble fluorescencia del miembro revela la reconexión de la fibra muscular durante la regeneración del miembro axolotl

SUMMARY: Axolotl limb regeneration is a fascinating characteristic that has attracted attention for several decades. Our previous studies on axolotl limb regeneration indicated that the satellite cells in the remnant muscles move distally into the blastema to regenerate new muscles that are separated by a gap from remnant muscles. Thereafter, the regenerative muscle fibers start to reconnect with remnant ones. In this study, the reconnection at the individual muscle fiber level was elucidated to test the hypothesis that this reconnection happens synchronously among involved muscles. Three pairs of EGFP+ mid-bud stage blastemas were transplanted onto freshly amputated stumps of RFP+ axolotls at the same thigh position to generate double fluorescence chimeric regenerative hindlimbs. These regenerative limbs were harvested very late far beyond they had reached the late differentiation stage. Fluorescence imaging of these limbs in cross sections revealed that in the proximal remnant part of the muscle fiber, reconnection occurred at a different pace among the muscles. In the major thigh muscle gracilis, the reconnection started from the periphery before it was completed. Furthermore, RFP+ muscle fibers contributed to muscle regeneration in the distal regenerative parts. Intriguingly, this red cell contribution was limited to ventral superficial muscles of the calf. This kind of double fluorescence chimeric limb regeneration model may help increase the understanding of the patterning of axolotl limb regeneration in late stages.

RESUMEN: La regeneración del miembro de Axolotl es una característica fascinante que ha llamado la atención durante varias décadas. Nuestros estudios previos sobre la regeneración del miembro del Axolotl indicaron que las células satélite en los músculos remanentes se mueven distalmente hacia el blastema para regenerar nuevos músculos que están separados por una brecha de músculos remanentes. A partir de entonces, las fibras musculares regenerativas comienzan a reconectarse con las restantes. En este estudio, se aclaró la reconexión a nivel de fibra muscular individual para probar la hipótesis de que esta reconexión ocurre sincrónicamente entre los músculos involucrados. Se trasplantaron tres pares de blastemas EGFP+ en la etapa de yema media en tocones recién amputados de axolotls RFP+ en la misma posición del muslo para generar miembros posteriores regenerativos quiméricos de fluorescencia doble. Estos miembros regenerativos se cosecharon muy tarde mucho más allá de haber alcanzado la etapa de diferenciación tardía. Las imágenes de fluorescencia de estos miembros en secciones transversales revelaron que en la parte remanente proximal de la fibra muscular, la reconexión se produjo a un ritmo diferente entre los músculos. En el músculo grácil, la reconexión comenzó desde la periferia antes de completarse. Además, las fibras musculares RFP+ contribuyeron a la regeneración muscular en las partes regenerativas distales. Curiosamente, esta contribución de glóbulos rojos se limitó a los músculos superficiales ventrales de la pantorrilla. Este tipo de modelo de regeneración quimérica de doble fluorescencia del miembro puede ayudar a aumentar la comprensión del patrón de la regeneración del miembro del Axolotl en etapas tardías.

Factor de crecimiento de hepatocitos intramuscular para la isquemia crítica de extremidades / Intramuscular injection of hepatocyte growth factor for critical limb ischemia

El pronóstico de la enfermedad arterial periférica, especialmente la isquemia crítica de las extremidades (CLI, por sus siglas en inglés) es malo, a pesar de la terapia endovascular, y muchos pacientes requieren la amputación del miembro inferior. En los estudios de los últimos años se ha propuesto la terapia con el factor de crecimiento de hepatocitos (HGF, también por sus siglas en inglés) en pacientes con CLI. Un factor que promueve la angiogénesis, regula la inflamación, inhibe la fibrosis y activa la regeneración de los tejidos es HGF(AU)