The aim was to analyze histologically the bone repair in a mandibular osteotomy model with different gaps between the segments. Nine male rabbits who underwent osteotomies on the mandibular body were fixed with a 1.5 system plate and no bone graft; group 1 (2 mm gap between segments), group 2 (5 mm gap between segments), and group 3 (8 mm gap between segments) were included. After 8 weeks they were euthanized and the sample was processed for histological analysis. Group 1 showed advanced bone repair with cartilaginous tissue and cancellous bone, showing osteoblasts and type III collagenous fibers. In group 2, a more delayed ossification was observed, with an extensive area of peripheral ossifying cartilage and chondrocytes in greater number at the center of the defect; group 3 showed no evidence of ossification with fibrous tissue, a very low level of chondrocytes, and some bone sequestrate. We can conclude that, in this animal model, 2 or 5 mm gap in the osteotomy could be repaired as bone when fixation is used. The size of the gap is an important factor for the use of bone grafts considering endochondral ossification. This model can be used for graft analysis and related technologies.

Regeneration of critical bone defects requires the use of biomaterials. The incorporation of osteoinductive agents, such as bone morphogenetic proteins (BMPs), improves bone formation. This study aimed to compare the efficacy of rhBMP‐2 in combination with different materials for bone regeneration in critical‐sized rat calvarial defects. This was an experimental animal study using 30 rats. In each rat, two 5‐mm critical‐size defects were made in the calvaria (60 bone defects in total) using a trephine. All rats were randomized to one of the six groups: control (C), autograft + rhBMP‐2 (A), absorbable collagen sponge + rhBMP‐2 (ACS), β‐tricalcium phosphate + rhBMP‐2 (B‐TCP), bovine xenograft + rhBMP‐2 (B), and hydroxyapatite + rhBMP‐2 (HA). The outcome was assessed after 4 and 8 weeks using histological description and the histological bone healing scale. Statistical analysis was performed using the Kruskal‐Wallis and Mann–Whitney U tests, with a p -value set at 0.05. The average bone healing scores per group were as follows: C group, 12.5; A group, 26.5; ACS group, 18.8; B‐TCP group, 26.2; HA group, 20.9; and B group, 20.9. The C group showed a significant difference between weeks 4 and 8 (p = 0.032). Among the 4‐week groups, the C group showed a significant difference compared to A (p = 0.001), ACS (p = 0.017), and B‐TCP (p = 0.005) groups. The 8‐week experimental group did not show any significant differences between the groups. The 5‐mm critical size defect in rat calvaria requires the use of bone biomaterials to heal at 4 and 8 weeks. rhBMP‐2, as applied in this study, showed no difference in new bone formation when combined with bovine, B‐TCP, or HA biomaterials.

Las glándulas anexas del sistema reproductor en mamíferos, presentan variaciones en relación a su localización, número, tamaño y forma. La próstata es impar, en perro y caballo su tamaño es similar a una castaña, en otros animales es difusa y extendida a lo largo de la uretra. En el hombre, es la glándula accesoria de mayor tamaño y en conejo se observa un complejo prostático formado por la propróstata, próstata y parapróstatas. Nuestro objetivo fue describir la morfología del complejo prostático de conejo, a través de estudios mesoscópicos, histológicos e histoquímicos y, de esta manera, sentar las bases para futuros estudios estereológicos y morfofuncionales. Utilizamos 5 conejos (Oryctolagus cuniculus), adultos, híbridos, alimentados con pellets y zanahorias ad libitum criados y mantenidos en cautiverio en el Bioterio de la Facultad de Medicina de la Universidad de La Frontera, Chile. Luego de sacrificados, los conejos fueron disecadas las glándulas anexas del sistema reproductor con la ayuda de una lupa ransor (10x), aislando el complejo prostático. Posteriormente, las muestras fueron fijadas en Bouin, durante 24 horas y procesadas para su inclusión en paraplast. Se realizaron cortes seriados de 5 µm de espesor, los cuales fueron teñidos para su análisis histológico e histoquímico. Los resultados anatómicos y mesoscópico del complejo prostático mostraron que la propróstata se localizaba caudal a la glándula vesicular y craneal a la próstata y esta última, craneal a la glándula bulbouretral. Ambas se relacionaban inferiormente con la uretra (parte mediana) y los conductos deferentes (parte lateral). Inferior y lateralmente a la propróstata se ubicaban las parapróstatas. Propróstata, próstata y parapróstatas presentaban conductos colectores que desembocaban en la uretra en forma separada. Histológicamente, estaban constituidas por acinos glandulares y tejido estromal formado por células musculares lisas y tejido conectivo. El epitelio es característico para cada glándula, observándose en la próstata y parapróstatas cálculos esféricos en el lumen de los acinos. La histoquímica reveló presencia de mucosustancias, principalmente en la próstata. Las glándulas del complejo prostático presentan claras diferencias anatómicas, histológicas e histoquímicas, lo que nos podría indicar que cada una de ellas, cumple roles funcionales específicos, en los procesos reproductivos

Aging is intricately linked to chronic low-grade systemic inflammation, which plays a significant role in various age-related conditions, including osteoarthritis (OA). The aging process significantly influences the development of OA due to alterations in cartilage composition, reduced proteoglycan content, dysregulation of growth factor signaling, and heightened oxidative stress. Propolis, a natural product renowned for its potent antioxidant and anti-inflammatory properties, has the potential to mitigate age-induced changes in cartilage. The primary objective of this study was to rigorously assess the impact of in vivo propolis treatment on the histopathological characteristics of knee articular cartilage in senescent rats. This study involved a cohort of twenty male Sprague–Dawley rats, randomly allocated into four distinct groups for comparative analysis: YR (control group consisting of young rats), SR (senescent rats), SR-EEP (senescent rats treated with an ethanolic extract of propolis, EEP), and SR-V (senescent rats administered with a control vehicle). This study employed comprehensive histological and stereological analyses of knee articular cartilage. Propolis treatment exhibited a significant capacity to alleviate the severity of osteoarthritis, enhance the structural integrity of cartilage, and augment chondrocyte density. These promising findings underscore the potential of propolis as a compelling therapeutic agent to counteract age-related alterations in cartilage and, importantly, to potentially forestall the onset of osteoarthritis.