Impact of Collared Peccaries Dycotiles tajacu (Artiodactyla: Tayassuidae) on understory vegetation in the tropical rainforest of the Nogal-La Selva Biological Corridor, Costa Rica / Impacto del pecarí de collar, Dycotiles tajacu (Artiodactyla: Tayassuidae) en la vegetación del sotobosque del bosque tropical húmedo del Corredor Biológico Local Nogal-La Selva, Costa Rica

Abstract Introduction: Evidence suggests that herbivores, such as peccaries, shape vegetation structure and diversity through predation, trampling, dispersal, and rooting behavior. Objective: To evaluate the impact of peccaries (Dycotiles tajacu) on the understory vegetation of the tropical rainforest in the Nogal-La Selva Local Biological Corridor, Costa Rica, comparing a site with the absence of peccaries to another with the presence of these animals. Methodology: From June to November 2021, 20 experimental exclusions and 20 free access plots, each measuring 2 m2 were used to quantify herbivory, the number of leaf blades, damaged leaves, healthy leaves, sapling height, and fallen biomass at both sites. Results: A higher sapling density was found in the Nogal Reserve, but a lower sapling diversity, while in La Selva there was a higher sapling diversity, but a lower density of seedlings. Herbivory and sapling height in La Selva exceeded those in Nogal. The exclusion of peccaries reduced seedling damage but did not affect the dynamics of fallen biomass. Conclusion: For the design, implementation, and evaluation of the effectiveness of biological corridors, it is crucial to consider plant-animal interactions to enhance the flow of ecological processes through functional and structural connectivity, analyzed from interactions such as those presented in this paper.

Resumen Introducción: Existe evidencia que herbívoros, como los saínos, dan forma a la estructura y diversidad de la vegetación a través del comportamiento de depredación, pisoteo, dispersión y enraizamiento. Objetivo: Evaluar el impacto de los saínos (Dycotiles tajacu) en la vegetación del sotobosque del bosque tropical húmedo en el Corredor Biológico Local Nogal-La Selva, Costa Rica, en un sitio con ausencia y en otro con presencia de saínos. Métodos: De junio a noviembre de 2021 se utilizaron 20 exclusiones experimentales y 20 parcelas de acceso libre de 2 m2, se cuantifico la herbivoría, número de láminas foliares, hojas dañadas, hojas sanas, altura de brinzales y biomasa caída en ambos sitios. Resultados: Se encontró una mayor densidad de brinzales en Reserva Nogal pero una menor diversidad, contrario en La Selva donde se encontró una mayor diversidad de brinzales, pero una menor densidad de plántulas. La herbivoría y la altura de brinzales en La Selva fue mayor que en Nogal. La exclusión de los saínos disminuyó el daño a las plántulas, pero no afectó la dinámica de la biomasa caída. Conclusión: Es necesario contemplar para el diseño, implementación y evaluación de la efectividad de corredores biológicos, las interacciones planta-animal, para potencializar el flujo de procesos ecológicos mediante la conectividad funcional y estructural, analizada a partir de interacciones como las presentadas en este trabajo.

Analysis of the Chemical Composition, Morphological Characterization, and Porosimetry of Allograft and Comparison with Xenograft for Dental Applications / Análisis de la Composición Química, Caracterización Morfológica y Porosimetría de Aloinjerto y Comparación con Xenoinjerto para Aplicaciones Odontológicas

SUMMARY: Tissue engineering aims to fabricate a scaffold that exhibits a suitable surface topography for a desired cellular response. Therefore, a study analyzing the characteristics of bone grafts is important for future research directions. This work aims to analyze the physical-chemical characteristics of commercially available bone grafts of human and bovine origin for dental use, using morphological analysis of the surface and chemical composition by variable pressure scanning electron microscope (VP-SEM) and energy-dispersive x-ray (EDX) spectrometry. In addition, pore diameter and surface area were analyzed by degassing method using a porosimeter, and particle size by laser diffraction. The analyzed allograft and xenograft particles differ in morphological characteristics and chemical composition. The allograft particles present a cuboidal and prismatic geometric morphology with angled edges and the absence of macropores. On the contrary, the xenograft particles present an irregular morphology with macropores in their structure. There is a statistically significant difference in C, P, and Ca between the xenograft and allografts (p < 0,05). The analyzed composition of allografts showed mainly the presence of C and O. In contrast, the composition of the xenograft was mainly Ca. These differences could influence the osteogenic properties of allografts and xenografts. This analysis provides basic information to understand the physicochemical properties of allografts and xenografts that facilitate cell-graft interaction.

La ingeniería de tejidos tiene como objetivo fabricar un andamio que muestre una topografía de superficie adecuada para una respuesta celular deseada. Por tanto, un estudio que analice las características de los injertos óseos es importante para futuros enfoques de investigación. Este trabajo tiene como objetivo analizar las características físico-químicas de injertos óseos de origen humano y bovino disponibles comercialmente para uso odontológico, mediante análisis morfológico de la superficie y composición química mediante microscopio electrónico de barrido de presión variable (VP-SEM) y x-dispersivo de energía. espectrometría de rayos (EDX). Además, el diámetro de los poros y el área superficial se analizaron mediante el método de desgasificación utilizando un porosímetro y el tamaño de las partículas mediante difracción láser. Las partículas de aloinjerto y xenoinjerto analizadas difieren en características morfológicas y composición química. Las partículas del aloinjerto presentan una morfología geométrica cúbica y prismática con bordes angulados y ausencia de macroporos. Por el contrario, las partículas de xenoinjerto presentan una morfología irregular con macroporos en su estructura. Existe una diferencia estadísticamente significativa en C, P y Ca entre el xenoinjerto y los aloinjertos (p < 0,05). La composición analizada de los aloinjertos mostró principalmente la presencia de C y O. Por el contrario, la composición del xenoinjerto fue principalmente Ca. Estas diferencias podrían influir en las propiedades osteogénicas de los aloinjertos y xenoinjertos. Este análisis proporciona información básica para comprender las propiedades fisicoquímicas de aloinjertos y xenoinjertos que facilitan la interacción célula-injerto.

Reparación tisular de los tejidos orales: una revisión de la literatura / Oral tissues healing: a review of the literature

El odontólogo realiza de forma rutinaria procedimientos que generan lesiones en los tejidos duros y blandos, por lo que resulta importante que el profesional conozca los procesos normales de cicatrización y reparación. La cicatrización es un fenómeno fisiológico que se presenta en cualquier tejido vivo que ha sido lesionado, que tiene importantes componentes vasculares y celulares que llevan una secuencia específica y que dependiendo de la magnitud de la lesión, el tejido podrá regenerar o cicatrizar según sea el caso. Asimismo, existen patologías sistémicas específicas y locales capaces de retrasar el proceso normal de cicatrización. El objetivo del presente artículo es explicar el proceso normal de reparación tisular de los tejidos orales y periorales (AU)

The dentist routinely performs procedures that generate injuries to hard and soft tissues, so it is important that the professional knows the normal healing and repair processes. Cicatrization is a physiological phenomenon that occurs in any living tissue that has been injured that has important vascular and cellular components that carry a specific sequence and that, depending on the magnitude of the lesion, the tissue may regenerate or heal as the case may be. Likewise, there are specific systemic and local pathologies capable of delaying the normal healing process. The aim of this article is to explain the normal tissue repair process of oral and perioral tissues (AU)

Implante Inmediato en Zona Estética Anterior con Pérdida Parcial de la Cortical Vestibular: Reporte De Caso y Revisión de Literatura

El tratamiento con implantes dentales hoy en día es un procedimiento clínico de rutina que permite rehabilitar a los pacientes con prótesis fijas. En este caso presentamos un tratamiento complejo de implantación inmediata del sector anterior con pérdida parcial de la cortical vestibular en el que se realizó una regeneración ósea guiada y provisionalización en un tiempo quirúrgico en un paciente con patología renal. Complementamos el estudio con una revisión de la efectividad de las técnicas utilizadas y las posibles respuestas celular asociadas a la patología renal.

Treatment with dental implants nowadays is a routine clinical procedure that allows patient rehabilitation with fixed prostheses. In this case we present a complex treatment of immediate implantation of the anterior sector with partial loss of the vestibular cortex, in which guided bone regeneration and provisionalization was performed in surgical time in a patient with kidney pathology. The study was complemented with a review of the effectiveness of the techniques used and the possible cellular responses associated with kidney pathology.

Effectiveness of leukocyte- and platelet-rich fibrin in the management of medication-related osteonecrosis of the jaws ­ a systematic review / Efectividad de la fibrina rica en leucocitos y plaquetas en el tratamiento de osteonecrosis mandibular relacionada con medicamentos: una revisión sistemática

Background: Medication-related osteonecrosis of the jaw (MRONJ) is a rare, but significant adverse event primarily associated with the intake of antiresorptive and antiangiogenic medications. Although antiresorptive and antiangiogenic the-rapies improve life expectancy, particularly in cancer patients, MRONJ may hamper the patient's quality of life due to pain, discomfort, anxiety, depression, speech impairment, difficulty in swallowing and eating, frequent medical and dental evaluations and treatments, and the possibility of treatment discontinuation. Leukocyte­ and Platelet-rich Fibrin (L-PRF) is an autologous platelet aggregate that promotes wound healing by stimulating re-epithelialization, angiogenesis, and extracellular matrix production. Aim: The present systematic review aimed to compare the results in the published literature on whether L-PRF is an effective and predictable adjuvant to surgical debridement of necrotic bone for improving the healing efficacy in patients with MRONJ. Materials and Methods: The PubMed, Scopus, Cochrane, Science Direct, LILACS, and Web of Science databases were searched using the predetermined MeSH terms and eligibility criteria, and the search yielded a total of five articles. Two studies were retrospective, and three studies were case series. Results: Seventeen participants received a combination of surgical debridement, L-PRF membrane, and antibiotics. Complete wound healing was observed in 70% of the participants, and most of them healed without any complications. Conclusions: L-PRF as an adjuvant to surgical debridement of necrosed bone appears to have a positive association with the healing outcome in patients with MRONJ.

Introducción: La osteonecrosis mandibular relacionada con medicamentos (ONMRM) es un evento adverso raro pero significativo asociado principalmente con la ingesta de medicamentos antirresortivos y antiangiogénicos. Aunque las terapias antirresortivas y antiangiogénicas mejoran la esperanza de vida, particularmente en pacientes con cáncer, la ONMRM puede obstaculizar la calidad de vida del paciente debido a dolor, incomodidad, ansiedad, depresión, discapacidad del habla, dificultad para tragar y comer, evaluaciones y tratamientos médicos y dentales frecuentes, y la posibilidad de interrupción del tratamiento. La fibrina rica en plaquetas y leucocitos (L-PRF) es un agregado de plaquetas autólogo que promueve la curación de heridas al estimular la reepitelización, la angiogénesis y la producción de la matriz extracelular. Objetivo: La presente revisión sistemática tuvo como objetivo comparar los resultados en la literatura publicada sobre si L-PRF es un adyuvante efectivo y predecible al desbridamiento quirúrgico del hueso necrótico para mejorar la eficacia curativa en pacientes con ONMRM. Materiales y Métodos: Las bases de datos de PubMed, Scopus, Cochrane, ScienceDirect, LILACS y Web of Science se registraron utilizando los términos DeCS/MeSH predeterminados y los criterios de elegibilidad, y la búsqueda arrojó un total de cinco artículos. Dos estudios fueron retrospectivos, y tres estudios fueron series de casos. Resultado: Diecisiete participantes recibieron una combinación de desbridamiento quirúrgico, membrana L-PRF y antibióticos. Se observó curación completa de heridas en el 70% de los participantes, y la mayoría de ellos se curaron sin ninguna complicación. Conclusión: L-PRF como adyuvante para el desbridamiento quirúrgico del hueso necrótico parece tener una asociación positiva con el resultado de curación en pacientes con ONMRM.

Células tronco e endodontia regenerativa / Stem cells and regenerative endodontics

Desde o incremento das pesquisas das células-tronco em 1961, por cientistas canadenses, os avanços em estudos, pesquisas e o desenvolvimento de novos tratamentos com esse tipo de recurso se mostram promissores. O uso de células-tronco é uma grande aposta tanto para a medicina quanto para a odontologia regenerativa. Os tratamentos com essa terapia podem oferecer mais qualidade de vida para as pessoas. O potencial dessas células tão especiais se encontra em duas características peculiares: elas são capazes de se multiplicarem e de se diferenciarem em outros tipos de células, como de tecidos, cartilagens e neurônios. É dessa maneira que elas têm um papel fundamental para estudos e tratamentos relacionados à regeneração. O uso de células-tronco na Odontologia torna possível diferentes processos odontológicos que oferecem mais qualidade de vida ao paciente. Isso porque fatores como defeitos genéticos, hábitos nocivos, cáries dentárias e perdas precoces dos dentes contribuem com a perda de dentes ao longo da vida. No início do século XXI, por volta dos anos de 2005, 2006, pesquisadores começaram a publicar em revistas internacionais da área uma nova técnica baseada no uso de célulastronco existentes no osso de sustentação dos dentes e na articulação dento alveolar. Esta técnica, chamada de Revascularização, promove o aparecimento de um novo tecido pulpar sadio, devolvendo ao dente sua vitalidade e higidez(AU)

Since the increase in stem cell research in 1961 by Canadian scientists, advances in studies, research and the development of new treatments with this type of resource have shown promise. The use of stem cells is a big bet for both medicine and regenerative dentistry. Treatments with this therapy can offer more quality of life for people. The potential of these very special cells lies in two peculiar characteristics: they are able to multiply and differentiate into other types of cells, such as tissues, cartilage and neurons. It is in this way that they play a key role for studies and treatments related to regeneration. The use of stem cells in dentistry makes possible different dental processes that offer more quality of life to the patient. That's because factors such as genetic defects, harmful habits, tooth decay, and early tooth loss all contribute to lifelong tooth loss. At the beginning of the twenty-first century, around the years 2005, 2006, researchers began to publish in international journals of the area a new technique based on the use of existing stem cells in the supporting bone of the teeth and in the alveolar tooth joint. This technique, called Revascularization, promotes the appearance of a new healthy pulp tissue, returning to the tooth its vitality and hygiene(AU)

Injertos Óseos en Quistes de los Maxilares. Reporte de un Caso

Los quistes de los maxilares son las lesiones óseas más comunes en la región maxilofacial. La enucleación de las lesiones y el cierre primario de los defectos, son en conjunto, el tratamiento óptimo hoy en día. En algunas ocasiones el defecto óseo resultante puede ser de un tamaño tan grande que afecta la estabilidad de dientes vecinos, comprometa la indemnidad del hueso o produce un retraso cicatrizal que incluso puede impedir una regeneración ósea completa. Se considera que esta falta de regeneración expone al paciente a riesgos de infección tardía, retraso de los tratamientos rehabilitadores en zonas de alta demanda estética y pérdida de vitalidad dentaria. Para disminuir el riesgo de alteraciones en la regeneración ósea completa de cavidades quísticas, se ha propuesto la posibilidad de que tras la enucleación del quiste se rellenen estos defectos con injertos óseos u otras técnicas de preservación alveolar para favorecer la cicatrización. Teóricamente el uso de estos injertos mejora la calidad y disminuye el tiempo de cicatrización ósea, permitiendo que el paciente recupere rápidamente las funciones habituales del componente dentoalveolar, acortando el periodo de cuidados postoperatorios que restringen la alimentación, los deportes o la rehabilitación oral. El actual trabajo tiene como objetivo realizar una revisión de la literatura respecto a los beneficios del uso de injertos óseos en el tratamiento quirúrgico de los quistes maxilares y presentar un caso clínico con los detalles quirúrgicos de esta técnica.

Jaw cysts are the most common bone lesions in the maxillofacial region. Enucleation of the lesions along with the primary closure of the defects are the optimal treatment nowadays. On some occasions, the resulting bone defect can be so large that it affects the stability of neighboring teeth, compromises the integrity of the bone, or produces a delayed healing that can even prevent complete bone regeneration. It is considered that the lack of regeneration exposes the patient to risk of infection, delay of rehabilitation treatments in areas of high aesthetic demand and loss of dental vitality. To reduce the risk of alterations in complete bone regeneration of cystic cavities, the possibility of filling these defects with bone grafts or other alveolar preservation techniques to promote healing, has been proposed after cyst enucleation. Theoretically, the use of these grafts improves the quality and decreases the bone healing time, allowing the patient to quickly recover the usual functions of the dentoalveolar component, limiting the period of postoperative care that restricts eating, sports or oral rehabilitation. The present work aims to carry out a review of the literature regarding the benefits of the use of bone grafts in the surgical treatment of maxillary cysts and to present a clinical case with the surgical details of this technique.

Fibrina rica en plaquetas como parte de la regeneración tisular en procedimientos quirúrgicos odontológicos / Platelet-rich fibrin as part of tissue regeneration in dental surgical procedures

Uno de los mejores biomateriales usados en odontología es la fibrina rica en plaquetas (PRF), es un concentrado plaquetario de segunda generación que se obtiene a partir de la centrifugación de sangre autóloga y no necesita aditivos. El presente documento busca determinar la eficacia del uso del PRF como parte de la regeneración de tejidos en procedimientos quirúrgicos odontológicos, tomando como base la literatura publicada en PubMed, Elsevier y Semantic Scholar entre 2018 y 2023, la búsqueda de artículos científicos fue ejecutada empleando las palabras clave platalet rich fibrin, regeneration, dentistry, blood buffy coat. La evidencia científica muestra que el PRF puede ser usado en su forma de membrana, gel, tapón, solo o combinado con otro biomaterial para conseguir propiedades biológicas exclusivas que promueven la regeneración y cicatrización mientras reduce los efectos adversos de los procedimientos quirúrgicos. Un ensayo clínico refirió la curación de alvéolos post exodoncia atraumática, y comprobó que la cicatrización con PRF muestra un índice de curación más alto en comparación con el grupo control. El sustento biológico de su eficacia radica en su capacidad para proliferar células que promueven la angiogénesis, osteogénesis y diferenciación celular, es decir, el reparo de tejidos lesionados. Todo esto nos permite llegar a la conclusión de que el PRF representa una alternativa viable y eficaz en procesos de regeneración de tejidos en procedimientos quirúrgicos odontológicos.

One of the best biomaterials used in dentistry is platelet-rich fibrin (PRF). It is a second-generation platelet concentrate obtained by centrifugation of autologous blood and requires no additives. The aim of this article is to determine the effectiveness of using PRF for tissue regeneration in dental surgery. The methodology used consists of a descriptive search of scientific articles that employ or study PRF as a biomaterial for tissue healing in the dental field and are available on PubMed, Elsevier, and Semantic Scholar. The literature shows that PRF can be used as a membrane, gel, cap form, alone or combined with other biomaterials to achieve unique biological properties that promote regeneration and healing while reducing the adverse effects of surgical procedures. For example, a clinical trial demonstrated healing of post-traumatic alveolar exodontia, proving that healing with PRF had a higher healing rate than in the control group. The biological basis of PRF's efficacy lies in its ability to proliferate cells that promote angiogenesis, osteogenesis, and cellular differentiation, and thus repair damaged tissue. All this leads us to conclude that PRF represents a viable and effective alternative in tissue regeneration processes in dental surgery procedures.

Fibroma ameloblástico mandibular: caso clínico / Fibroblastic fibroma mandibular: a clinical case

El fibroma ameloblástico (FA) se describe como una neoplasia benigna de origen odontogénico mixto que suele presentarse entre la primera y segunda década de vida, frecuentemente en los molares permanentes inferiores. Por lo general es asintomático, pero las lesiones de gran tamaño suelen acompañarse con dolor e inflamación. Su tratamiento por lo regular es conservador. Se describe el caso de un fibroma ameloblástico en un paciente de 13 años de edad, que involucraba cuerpo y ángulo mandibular izquierdo, tratado de manera conservadora, se realiza extirpación del tumor, regeneración ósea guiada y rehabilitación con implante dental (AU)

Ameloblastic fibroma (AF) is described as a benign neoplasm of mixed odontogenic origin that usually presents between the first and second decade of life, frequently in lower permanent molars. It is usually asymptomatic, but large lesions are usually accompanied by pain and inflammation. His treatment is generally conservative. The clinical case of an ameloblastic fibroma in a 13-year-old patient is described, involving the left mandibular body and angle, treated conservatively, tumor removal, guided bone regeneration and rehabilitation with dental implants are performed (AU)

Temporal evolution of postsurgical bone repair in a rabbit model: A [99mTc]Tc-MDP scintigraphic study

Abstract Bone regeneration is crucial for repairing bone tissue following various injuries. Research techniques that enable the study of metabolic changes in bone tissue under different conditions are important for understanding bone repair and remodeling. This study used bone scintigraphy to evaluate osteogenesis secondary to osteotomy in a preclinical model of New Zealand rabbits. For this purpose, we conducted a longitudinal, prospective, case-control study in which scintigraphic variables were measured in both the right forearm (case-operated) and the left forearm (control - non-operated). The study sample consisted of 10 rabbits subjected to osteotomy, followed by a 12-week postoperative evaluation period, divided into six imaging stages at 1, 2, 3, 4, 8, and 12 weeks. We observed that the operated forearm showed significantly higher external radiation than the control side, using the pinhole collimator, denoting an increase in the biodistribution and tropism of the radiopharmaceutical to the operated forearm. Among the three evaluated time points, osteoblastic activity was highest in the second week and presented a significant decline in the 8th and 12th weeks, denoting regeneration and resolution of the surgical injury; the control forearm was also influenced by the inactivity imposed by the operated forearm. This fact was notably evidenced by the reduction in the metabolic activity of osteoblasts in the left forearm. Our study suggested that bone scintigraphy was sensitive enough to semi-quantitatively differentiate the metabolic activity of osteoblasts in the operated forearm in the three temporal landmarks evaluated in the study.

The applications of the plasma matrix in the treatments of dental pulp and periapical diseases / 口腔疾病防治

@#The plasma matrix is a kind of autologous blood conduct. It has been widely used in maxillofacial tissue regeneration, skin cosmetology and some other fields. Recently, to preserve the dental pulp as well as the teeth, pulp regeneration therapy and apical surgery have become increasingly important as well as the applications of bioactive materials. As a kind of autologous bioactive material, the plasma matrix has some natural advantages as it is easy to obtain and malleable. The plasma matrix can be used in the following cases: ①pulp revascularization of young permanent teeth with open apical foramina that cannot stimulate apical bleeding; ② apical barrier surgery with bone defects and large area perforation repair with bone defects or root sidewall repair surgery; ③ apical surgeries of teeth with large area of apical lesions, with or without periodontal diseases. The plasma matrix is a product derived from our blood, and there are no obvious contraindications for its use. Several systematic reviews have shown that the plasma matrix can effectively promote the regenerative repair of dental pulp in patients with periapical diseases. However, the applications of plasma matrix are different because its characteristics are affected by different preparation methods. In addition, there is still a lack of long-term clinical researches on the plasma matrix, and the histological evidences are difficult to obtain, so a large number of in vitro and in vivo experimental studies are still needed. This article will describe the applications of different kinds of plasma matrix for dental pulp regeneration and bone tissue regeneration in apical surgeries to provide references for clinicians in indication selection and prognosis evaluation.

Research progress on cemental tears in terms of clinical diagnosis and treatment / 口腔疾病防治

@#A cemental tear is defined as an incomplete or complete detachment of the cementum along the dentino-cemental junction (CDJ) or the incremental line within the body of the cementum, which can also involve part of the root dentine adjacent to the cementum. The pathogenesis of cemental tears is not fully elucidated. From the literature review, possible predisposing factors were identified, including tooth type, sex, age, periodontitis, previous periodontal treatment or root canal treatment, history of dental trauma, and occlusal trauma or excessive occlusal force. The morphology of cemental tears can be either piece-shaped or U-shaped, which usually contributes to periodontal and periapical breakdown. Clinically, cemental tears have a unitary periodontal pocket and present with symptoms mimicking localized periodontitis, apical periodontitis, and vertical root fractures. Imaging examination is of great significance for the clinical diagnosis of cemental tears, which often manifest as thin ‘prickle-like’ radiopaque masses located longitudinally adjacent to the affected root surface. Exploratory surgery is needed in some cases. Although intraoperative cemental fragments and cemental lines on the root surface can assist in the diagnostic process, histopathology examination is the gold standard for the diagnosis of cemental tears. The treatment methods vary depending on the timing of the correct diagnosis and the clinical or radiological manifestations. With the development of regenerative biomaterials and the development of intentional replantation, an increasing number of affected teeth can survive for a long time. The aim of this review is to systematically describe the biological basis and predisposing factors, clinical features, radiographic and histological characteristics, diagnosis and clinical management of cemental tears, and treatment outcomes to help make a clear diagnosis and develop a personalized treatment plan.

Summary of basic research on liver transplantation in China of 2023 / 器官移植

Liver transplantation is the optimal treatment for end-stage liver disease and hepatocellular carcinoma, which can significantly improve clinical prognosis and quality of life of patients. However, multiple challenges, such as rejection, immune tolerance, shortage of donor liver, preservation of donor liver, ischemia-reperfusion injury and postoperative complications, <i>etc.</i>, limit the efficacy of liver transplantation in clinical practice. Research teams in China have made significant contributions to the basic research related to liver transplantation by making continuous efforts and combining the development of emerging technologies, interdisciplinary integration and other emerging fields. In this article, the frontier progress in the basic research of liver transplantation in 2023 was reviewed, highlighting the progress made by Chinese research teams in the basic research of liver transplantation, aiming to provide reference for promoting the integration of Chinese characteristics into the research of liver transplantation, accelerate the integration of Chinese liver transplantation research with international community, and promote further advancement of liver transplantation in China.

Bionic design,preparation and clinical translation of oral hard tissue restorative materials / 北京大学学报(医学版)

Oral diseases concern almost every individual and are a serious health risk to the popula-tion.The restorative treatment of tooth and jaw defects is an important means to achieve oral function and support the appearance of the contour.Based on the principle of"learning from the nature",Deng Xu-liang's group of Peking University School and Hospital of Stomatology has proposed a new concept of"microstructural biomimetic design and tissue adaptation of tooth/jaw materials"to address the worldwide problems of difficulty in treating dentine hypersensitivity,poor prognosis of restoration of tooth defects,and vertical bone augmentation of alveolar bone after tooth loss.The group has broken through the bottle-neck of multi-stage biomimetic technology from the design of microscopic features to the enhancement of macroscopic effects,and invented key technologies such as crystalline/amorphous multi-level assembly,ion-transportation blocking,and multi-physical properties of the micro-environment reconstruction,etc.The group also pioneered the cationic-hydrogel desensitizer,digital stump and core integrated restora-tions,and developed new crown and bridge restorative materials,gradient functionalisation guided tissue regeneration membrane,and electrically responsive alveolar bone augmentation restorative membranes,etc.These products have established new clinical strategies for tooth/jaw defect repair and achieved inno-vative results.In conclusion,the research results of our group have strongly supported the theoretical im-provement of stomatology,developed the technical system of oral hard tissue restoration,innovated the clinical treatment strategy,and led the progress of the stomatology industry.

Risk factors of perioperative hypertension in dental implant surgeries with bone augmentation / 北京大学学报(医学版)

Objective:To investigate the characteristics and risk factors of perioperative hypertension during dental implant surgeries with bone augmentation.Methods:A retrospective cohort study was con-ducted.Seven hundred and twenty-eight cases underwent dental implant placement and bone augmenta-tion in Peking University School and Hospital of Stomatology from September 2021 to August 2022 were recruited in this study according to the inclusion and exclusion criteria.They were divided into different groups according to the exposure factors which were gender,age,surgical time,and surgical approach.The correlation between perioperative hypertension and the exposure factors was analyzed.Results:The average systolic blood pressure variability was 9.93％±6.63％(maximum 50.41％),the average dias-tolic blood pressure variability was 12.45％±8.79％(maximum 68.75％),and the average mean arte-rial pressure variability was 10.02％±6.61％(maximum 49.48％).The incidence rate of perioperative hypertension was 26.77％.Male,age ≥ 60 years,and surgical time＞60 minutes were risk factors for perioperative hypertension(P＜0.05),and the relative risks(95％CI)were 1.74(1.21-2.50),2.35(1.54-3.58),and 1.65(1.15-2.38),respectively.There was no significant difference in the inci-dence of perioperative hypertension among the guided bone regeneration,sinus floor elevation with transal-veolar approach,and sinus floor elevation with lateral window approach(P＞0.05).However,the risk factors varied according to bone augmentation approaches.For the patients underwent guided bone rege-neration,the risk factors for perioperative hypertension included male,age≥60 years,and surgical time＞60 minutes(P＜0.05).For the patients underwent maxillary sinus lift with transalveolar approach,the risk factor for perioperative hypertension was age ≥ 60 years(P＜0.05).For the patients underwent maxillary sinus lift with lateral window approach,male,age ≥60 years,and surgical time＞60 minutes were not risk factors for perioperative hypertension(P＞0.05).Conclusion:There was a certain risk of periopera-tive hypertension in oral implantation with bone augmentation.The influence of male,age ≥60 years and sur-gical time＞60 minutes on perioperative hypertension was related to the approach of bone augmentation.

Improvement effect of ligustilide on rats with heart failure by regulating PKD1/HIF-1α/VEGF pathway / 吉林大学学报(医学版)

Objective:To discuss the effect of ligustilide on the cardiac function and angiogenesis in the rats with heart failure,and to clarify its regulatory effect on protein kinase D1(PKD1)/hypoxia-inducible factor-1α(HIF-1α)/vascular endothelial growth factor(VEGF)pathway.Methods:The SD rats were randomly divided into sham operation group,model group,ligustilide group,PKD1/HIF-1α/VEGF signaling pathway inhibitor CID755673(CID)group,and ligustilide+CID group.The heart failure rat model was established by ligation of the left anterior descending coronary artery.The rats in ligustilide group were injected intravenously with 20 mg·kg-1 ligustilide,the rats in CID group were injected intraperitoneally with 50 mg·kg-1 CID,and the rats in ligustilide+CID group were injected intraperitoneally with 50 mg·kg-1 CID followed by intravenous injection of 20 mg·kg-1 ligustilide,once per day for 4 consecutive weeks.The cardiac function indexes of the rats in various groups were detected by echocardiography;the percentages of myocardial infarction areas of the rats in various groups were detected by 2,3,5-triphenyltetrazolium chloride(TTC)staining;the pathomorphology of myocardium tissue of the rats in various groups was observed by HE staining;the expression levels of PKD1,HIF-1α,CD31,and VEGF mRNA and proteins in ischemic area of myocardium tissue of the rats in various groups were detected by real-time fluorescence quantitative PCR(RT-qPCR)and Western blotting methods.Results:Compared with sham operation group,the rats in model group and CID group had altered myocardial cell morphology,increased intercellular gaps,disorganized arrangement,visible muscle fiber breaks and inflammatory cell infiltration;the rats in ligustilide group and ligustilide+CID group had relatively orderly myocardial fiber arrangement,fewer myocardial fiber breaks and decreased number of inflammatory cells.Compared with sham operation group,the left ventricular ejection fraction(LVEF)and left ventricular fractional shortening(LVFS)of the rats in model group were decreased(P<0.05),the left ventricular end-systolic diameter(LVESD)and left ventricular end-diastolic diameter(LVEDD)were increased(P<0.05),and the expression levels of PKD1,HIF-1α,CD31,and VEGF mRNA and proteins in myocardium tissue were decreased(P<0.05).Compared with model group,the LVEF and LVFS of the rats in ligustilide group were increased(P<0.05),the LVESD and LVEDD were decreased(P<0.05),the percentage of myocardium infarction area was decreased(P<0.05),and the expression levels of PKD1,HIF-1α,CD31,and VEGF mRNA and proteins in myocardium tissue were increased(P<0.05);compared with model group,the LVEF and LVFS of the rats in CID group were decreased(P<0.05),the LVESD and LVEDD were increased(P<0.05),the percentage of myocardium infarction area was increased(P<0.05),and the expression levels of PKD1,HIF-1α,CD31,and VEGF mRNA and proteins in myocardium tissue were decreased(P<0.05);compared with ligustilide group,the LVEF and LVFS of the rats in ligustilide+CID group were decreased(P<0.05),the LVESD and LVEDD were increased(P<0.05),the percentage of myocardium infarction area was increased(P<0.05),and the expression levels of PKD1,HIF-1α,CD31,and VEGF mRNA and proteins in myocardium tissue were decreased(P<0.05);compared with CID group,the LVEF and LVFS of the rats in ligustilide+CID group were increased(P<0.05),the LVESD and LVEDD were decreased(P<0.05),the percentage of myocardium infarction area was decreased(P<0.05),and the expression levels of PKD1,HIF-1α,CD31,and VEGF mRNA and proteins in myocardium tissue were increased(P<0.05).Conclusion:Ligustilide can promote the angiogenesis,reduce the myocardium infarction area,and improve the cardiac function in the rats with heart failure;it works through activation of the PKD1/HIF-1α/VEGF pathway.

Progress of LINGO-1 in neurological diseases / 国际儿科学杂志

LINGO-1，a Nogo receptor-interacting protein-1 rich in leucine repeat sequences and immunoglobulin structural domains，which is specifically expressed in neurological diseases. In recent years，more and more evidences indicate that LINGO-1 plays an important role in glial scar formation，cell death and inflammatory reaction. LINGO-1 inhibits oligodendrocyte activation，and prevents axon and myelin formation and functional recovery，and is therefore considered to be a negative regulator of neuronal survival，neurite extension and axon myelination. The change of LINGO-1 level is related to the occurrence and development of many neurological diseases. This article reviews the physiological function of LINGO-1 and summarizes the latest research progress of LINGO-1 in multiple sclerosis，spinal cord injury，neonatal brain injury and epilepsy，so as to explore new strategies for the treatment of neurological diseases.

Research Progress on the Mechanism of Acupuncture Intervention on Alzheimer's Disease / 广州中医药大学学报

Alzheimer's disease(AD)is a multi-cause neurodegenerative disease characterized by memory impairment.There have been serious obstacles to the effective treatment of AD.Acupuncture,as a component of traditional Chinese medicine,plays an important role in the treatment of AD.Acupuncture has been shown to protect neurons from degeneration and promotes axonal regeneration in neurodegenerative diseases such as AD.According to existing studies,the mechanisms of acupuncture on AD include the following aspects:modulation of Aβ metabolism,tau phosphorylation,cholinergic neurotransmitters,neuroinflammation,synaptic and neuronal function,autophagy,brain glucose metabolism,intestinal flora,and inhibition of nerve cell apoptosis,which in turn improves cognition.

Establishment and application of animal models of myocardial infarction / 解剖学报

Myocardial infarction is one of the severe cardiovascular diseases.The patients with myocardial infarction die of heart failure or arrhythmia.In recent years,the studies in myocardial infarction therapies have advanced greatly,especially the preclinical experimental studies.The experimental studies of myocardial infarction often rely on animal models.Therefore,successful establishment of the myocardial infarction models has important application value in exploring the new techniques and measures for repairing the infarcted myocardium.In this paper,the techniques in establishment of the myocardial infarction models and strategies of their application are summarized.

Observation on A-PRF promoting regeneration of osteochondral defects in rabbit knee joints / 上海交通大学学报（医学版）

Objective·To explore the role of advanced platelet-rich fibrin(A-PRF)in osteochondral regeneration.Methods·Bone-marrow mesenchymal stem cells(BMSCs)and knee joint chondrocytes were obtained from New Zealand rabbits.A-PRF was obtained by low-speed centrifugation of the heart blood of rabbits.The histological structure of A-PRF was observed by an optical microscope.The release of growth factors in A-PRF was detected by ELISA,including platelet-derived growth factor,transforming growth factor-β,insulin-like growth factor,vascular endothelial growth factor,epidermal growth factor and fibroblast growth factor.A-PRF's cytotoxicity and capability for promoting the proliferation of rabbit BMSCs were detected by live/dead double staining and MTT methods.The effect of A-PRF on the gene expression of type Ⅱ collagen,aggrecan,alkaline phosphatase(ALP)and osteocalcin(OCN)in rabbit BMSCs was detected by real-time fluorescence quantitative polymerase chain reaction(qRT-PCR).Transwell chambers were used to determine the effect of A-PRF on the migration ability of rabbit BMSCs and the chondrocytes.Rabbit knee osteochondral defect models were established,and 18 rabbits were randomly divided into 3 groups.The A-PRF group(n=6)was implanted with A-PRF in the defect,the A-PRF+BMSCs group(n=6)was implanted with rabbit BMSCs on A-PRF,and the control group(n=6)did not undergo implantation.The rabbits were sacrificed 12 weeks after surgery and the knee joint specimens were stained with hematoxylin-eosin(H-E),toluidine blue and safranin O/fast green.Based on the surface morphology and histology of the knee joints,the International Cartilage Repair Society(ICRS)scoring system was used for macroscopic and histological scoring.Results·A-PRF had a loose network structure and can slowly release growth factors.No cytotoxicity to rabbit BMSCs was observed after adding A-PRF,and the the capability for promoting the proliferation of rabbit BMSCs was significantly increased at 24,48 and 72 h after adding A-PRF(all P<0.05).Chondrogenesis-related gene Ⅱ collagen and aggrecan,as well as osteogenesis-related genes ALP and OCN were significantly up-regulated(all P<0.05).After adding A-PRF,the migration abilities of rabbit BMSCs and chondrocytes were significantly enhanced(both P<0.05),and the migration ability of rabbit BMSCs was significantly higher than that of chondrocytes(P=0.025).The joint surface morphology in the rabbit knee joint defect models was observed.It can be seen that the defects in the A-PRF group and the A-PRF+BMSCs group were basically restored,while the the defects in the control group were only covered by soft tissue.In the ICRS macroscopic score,there was no statistical difference between the A-PRF group and the A-PRF+BMSCs group,but the scores of the two groups were all significantly higher than those of the control group(all P<0.05).According to the histological results,both the A-PRF group and the A-PRF+BMSCs group formed osteochondral repair,but the cartilage in the A-PRF group was more mature,while the control group formed fibrous repair.In the ICRS histological score,there was no statistical difference between the A-PRF group and the A-PRF+BMSCs group,but the scores of both the groups were significantly higher than those of the control group(both P<0.05).Conclusion·Autologous A-PRF has good biocompatibility and the capability for promoting the proliferation of BMSCs.It can promote the repair of cartilage and subchondral bone both in vitro and in vivo.