A novel mitochondria-targeting method using special staining for the detection of apoptotic hepatocytes.

Early detection of apoptotic cells on histological slides is of major importance for both diagnostic and research areas. In the current study, the aim was to propose a convenient method to stain the mitochondria and establish whether hepatocytes undergoing apoptosis can be identified in tissue sections using the proposed method. Liver tissue from five adult chinchillas was fixed with 10% neutral buffered formalin for Goldner's trichrome (GT) and Groat's iron hematoxylin and eosin (HE) stains and with Kolster's fixative for the Heidenhain's iron hematoxylin procedure. The HE and GT-stained sections showed the morphological features consistent with apoptosis i.e., homogenous intensely acidophilic cytoplasm, cell shrinkage with an irregular outline, nuclear shrinkage with cloudy karyoplasm, and karyopyknosis in the late stage. Sections stained with Heidenhain's iron hematoxylin method was used to pinpoint mitochondria and revealed cells which were undergoing the first stages of the apoptosis process i.e., disappearance of mitochondria from the cell, chromatin condensation and margination, paracentral localization of nucleoli, and vacuolated nuclei. In more advanced stages of apoptosis, cells presented significant nuclear and cytoplasmic changes. It was concluded that this is the first report targeting the mitochondria, by performing inexpensive histological staining techniques, in order to assess dead cells in situ.

Osseointegration of titanium scaffolds manufactured by selective laser melting in rabbit femur defect model.

The aim of this study was to assess the osseointegration of two series of titanium (Ti) scaffolds with 0.8 and 1 mm cell size obtained by Selective Laser Melting (SLM) technique. One of the series had the Ti surface unmodified, while the other had the Ti surface coated with silicon-substituted nano-hydroxyapatite (nano-HapSi). The scaffolds were implanted in the femur bone defects of 6 White Californian male rabbits: three animals were implanted with 0.8 mm cell size scaffolds and three animals with 1 mm cell size scaffolds, respectively. The bone fragments and scaffolds harvested at 2, 4 and 6 months were histologically analyzed using conventional light microscopy (LM) and scanning electron microscopy (SEM) for the qualitative evaluation of the bone tissue formed in contact with the scaffold. Both LM and SEM images indicated a better osseointegration for nano-HapSi coated Ti scaffolds. LM revealed that the compact bone formed in the proximity of nano-HapSi-coated scaffolds was better organized than spongy bone associated with unmodified scaffolds. Moreover, Ti scaffolds with meshes of 0.8 mm showed higher osseointegration compared with 1 mm. SEM images at 6 months revealed that the bone developed not only in contact with the scaffolds, but also proliferated inside the meshes. Nano-HapSi-coated Ti implants with 0.8 mm meshes were completely covered and filled with new bone. Ti scaffolds osseointegration depended on the mesh size and the surface properties. Due to the biocompatibility and favorable osseointegration in bone defects, nano-HapSi-coated Ti scaffolds could be useful for anatomical reconstructions.

Diagnostic and therapeutic approaches in oral cavity granulomas based on new data concerning their origin and pathogenesis.

Giant cell granulomas in the oral cavity are reactive hyperplastic lesions that arise either peripherally in the mucoperiosteum or centrally in the bone. The peripheral giant cell granuloma (PGCG) is a benign lesion induced by local chronic irritation. It may develop at any age, and tends to be more frequent in females. Central giant cell granuloma (CGCG) is a reactive lesion of unknown etiology. It commonly occurs in children and young adults. It is also predominant in females and frequently located in the anterior part of the mandible. Histologically, PGCG and CGCG have similar features. The lesions are non-encapsulated proliferations of oval and spindle-shaped mononuclear cells (MCs) and multiple multinucleated giant cells (MGCs) in a vascular supporting stromal tissue, associated with foci of hemorrhage. Despite the similar microscopic features, PGCG and CGCG have different clinical behavior. PGCG is usually reduced in size and asymptomatic. It grows locally, as an exophytic lesion on the alveolar mucosa, but may become slightly infiltrative in the underlying periosteum and bone. After complete excision and curettage, it has a low recurrence rate. Contrarily, CGCG has an aggressive behavior, with rapid growth and intense osteolytic activity causing perforation of the cortical plate, teeth malposition and pain. Moreover, it is characterized by a high recurrence rate. This review focuses on the origin and activating pathways of MCs and MGCs, discusses the mechanisms underlying their biological activity, tries to explain the variable clinical behavior and proposes therapeutic approaches for the granulomas associated with the jaw bones.

Osseointegration of zirconium dental implants three months after insertion in rabbit femur. Histopathological study.

Implantology is a highly researched field with a constant concern in finding and studying new implant materials. Lately, zirconium has become a very attractive alternative to the detriment of titanium, but the research results were sometimes contradictory. Thus, we considered as opportune to study the osseointegration of zirconium dental implants in rabbit femur, three months after insertion. The biological material was represented by five rabbits and the experimental protocol was approved by the Ethics Committee of the University of Oradea, Romania. The implants (zirconium ceramic dental implants: 5 mm length, 2.6 mm diameter) were inserted in the femur under controlled conditions, after creating a bone defect. The animals received the appropriate postoperative care. Three months later, the implantation area was harvested and processed for histological examination. The assessment of the osseointegration process of the zirconium implants showed that they were very well tolerated by the host organism that did not trigger any rejection processes. Approximately 80% of the compromised bone was replaced with newly formed bone in advanced stages of remodeling and consolidation. The proliferated bone near the implants acquired a structure similar to the rabbit diaphyseal bone, but with higher density and size of the osteons. The stage reached by the osseointegration process three months after the insertion of the implants, ensures a good consolidation of the implants that supports the prosthetic structures, which are to be built on them.

Mandibular aneurysmal bone cyst in an elderly patient: Case report.

OBJECTIVE: The article aims to highlight the challenge of establishing the presumptive aetiological diagnosis when unilocular or multilocular radiolucencies are identified in an elderly patient's jawbones. MATERIALS AND METHODS: A mandibular cyst-like lesion was identified in a 73-year-old patient. The therapeutic decision was cyst enucleation and grafting of the bone defect. RESULTS: The initial presumptive diagnosis was invalidated by the histopathological examination that revealed the features characteristic for the aneurysmal bone cyst. CONCLUSION: Aneurysmal bone cyst in an elderly patient is a rare condition.

The effect of plasma rich in growth factors in bone augmentation after sinus lift complications: a case report.

The case report describes a sinus membrane elevation procedure, where the augmentation was performed exclusively with plasma rich in growth factors (PRGF) and fibrin clot, followed by osseous regeneration at eight months. The patient exhibited a marked osseous atrophy in the premolar-molar area of the left superior alveolar process. Initially, we performed a sinus membrane elevation, with autologous bone on the sinus floor and bovine bone, followed by horizontal augmentation with autologous bone harvested from the mandibular ramus. The fragments were covered with PRGF and fibrin clot. Implants were inserted six months post-intervention, but due to the insertion high speed, a vestibular abscess occurred three months later. The implants and sinus graft were removed; after curettage, the sinus was filled with PRGF and fibrin clot. Eight months later, we observed the bone regeneration and the implants were reinserted. Along with implant insertion, bone was harvested for histological examination. Microscopically, the bone formation was revealed in the sinus, with differences between crestal and apical zones. The bone remodeling process was more advanced in the crestal zone compared with the apical zone. Bone regeneration was complete, and the bone density allowed the implant insertion with appropriate primary stability. Four months after implant insertion, the panoramic radiography and cone-beam computed tomography (CBCT) confirmed the implant osseointegration. Results obtained after using PRGF and fibrin clot alone as osseous addition materials in sinus lifting are highly promising, but in order to draw scientifically reasoned conclusions, further clinical studies are required.

Comparative immunohistochemical assessment of the effect of repetitive anesthesia with isoflurane and sevoflurane on rat liver / Avaliação imunohistoquímica comparativa do efeito da anestesia repetitiva com isoflurano e sevoflurano sobre o fígado de rato

Abstract Background and objectives: Inhalation anesthetics are used in human, as well as veterinary medical practice. In the present study we investigated the effect of isoflurane and sevoflurane on rat hepatocytes. Methods: A total of 40 Wistar female rats were used in this study. Animals were divided in groups of 5 rats. Groups IM, SM served as control groups. Groups I1, I2, I3 were used to study isoflurane and S1, S2, S3 for sevoflurane study. They were anesthetized 3 times, for 2 h long, at 2 days interval with a concentration of: 1.5% isoflurane (I1, I2, I3) and 2% sevoflurane (S1, S2, S3). The oxygen supply throughout the anesthesia was 1 L O2/min. Groups IM, IS, I1, S1 were sacrificed immediately after the last anesthesia. Groups I2, S2 were sacrificed 6 h after the last anesthesia, and groups I3, S3, 24 h post-anesthesia. Liver samples were harvested to highlight caspase-3 in apoptotic hepatocytes. Results: Following isoflurane administration, there were less than 1% cells in apoptosis highlighted in rat livers from groups IM, I1 and I2. At 24 h post-anesthesia (group I3), a small number of apoptotic hepatocytes was highlighted (around 3.23% cells in apoptosis), with a strictly periacinar disposition, randomly distributed in a small number of hepatic lobules. After sevoflurane administration, less than 1% apoptotic hepatocytes were identified at all control moments throughout the study. Conclusions: The results suggest that the anesthetics do not present a considerable hepatotoxicity. The comparative assessment of the two anesthetics shows that sevoflurane is superior to isoflurane.

Resumo Justificativa e objetivos: Anestésicos inalatórios são usados em humanos e também na prática médica veterinária. No presente estudo investigamos o efeito de isoflurano e sevoflurano em hepatócitos de rato. Métodos: Foram usados neste estudo 40 ratos Wistar fêmeas. Os animais foram divididos em grupos de cinco. Os grupos IM e SM serviram como controle. Os grupos I1, I2 e I3 foram usados para o estudo de isoflurano e os grupos S1, S2 e S3 para o estudo de sevoflurano. Os ratos foram anestesiados três vezes, durante duas horas em intervalos de dois dias, com uma concentração de 1,5% de isoflurano (I1, I2, I3) e 2% de sevoflurano (S1, S2, S3). O fornecimento de oxigênio durante a anestesia foi de 1 L O2/min. Os grupos IM, IS, I1 e S1 foram sacrificados imediatamente após a última anestesia. Os grupos I2 e S2 foram sacrificados seis horas após a última anestesia e os grupos I3 e S3 foram sacrificados 24 horas após a anestesia. Amostras dos fígados foram colhidas para ressaltar a caspase-3 em hepatócitos apoptóticos. Resultados: Após a administração de isoflurano, havia menos de 1% das células em apoptose em destaque nos fígados dos ratos dos grupos IM, I1 e I2. Às 24 horas após a anestesia (grupo I3), um pequeno número de hepatócitos apoptóticos foi destacado (3,23% de células em apoptose), com uma disposição estritamente periacinar, distribuídos aleatoriamente em um pequeno número de lóbulos hepáticos. Após a administração do sevoflurano, menos de 1% de hepatócitos apoptóticos foi identificado em todos os momentos de controle ao longo do estudo. Conclusões: Os resultados sugerem que os anestésicos não apresentam uma hepatotoxicidade considerável. A avaliação comparativa dos dois anestésicos mostra que sevoflurano é superior ao isoflurano.

Comparative immunohistochemical assessment of the effect of repetitive anesthesia with isoflurane and sevoflurane on rat liver.

BACKGROUND AND OBJECTIVES: Inhalation anesthetics are used in human, as well as veterinary medical practice. In the present study we investigated the effect of isoflurane and sevoflurane on rat hepatocytes. METHODS: A total of 40 Wistar female rats were used in this study. Animals were divided in groups of 5 rats. Groups IM, SM served as control groups. Groups I1, I2, I3 were used to study isoflurane and S1, S2, S3 for sevoflurane study. They were anesthetized 3 times, for 2h long, at 2 days interval with a concentration of: 1.5% isoflurane (I1, I2, I3) and 2% sevoflurane (S1, S2, S3). The oxygen supply throughout the anesthesia was 1LO2/min. Groups IM, IS, I1, S1 were sacrificed immediately after the last anesthesia. Groups I2, S2 were sacrificed 6h after the last anesthesia, and groups I3, S3, 24h post-anesthesia. Liver samples were harvested to highlight caspase-3 in apoptotic hepatocytes. RESULTS: Following isoflurane administration, there were less than 1% cells in apoptosis highlighted in rat livers from groups IM, I1 and I2. At 24h post-anesthesia (group I3), a small number of apoptotic hepatocytes was highlighted (around 3.23% cells in apoptosis), with a strictly periacinar disposition, randomly distributed in a small number of hepatic lobules. After sevoflurane administration, less than 1% apoptotic hepatocytes were identified at all control moments throughout the study. CONCLUSIONS: The results suggest that the anesthetics do not present a considerable hepatotoxicity. The comparative assessment of the two anesthetics shows that sevoflurane is superior to isoflurane.

[Comparative immunohistochemical assessment of the effect of repetitive anesthesia with isoflurane and sevoflurane on rat liver]. / Avaliação imunohistoquímica comparativa do efeito da anestesia repetitiva com isoflurano e sevoflurano sobre o fígado de rato.

BACKGROUND AND OBJECTIVES: Inhalation anesthetics are used in human, as well as veterinary medical practice. In the present study we investigated the effect of isoflurane and sevoflurane on rat hepatocytes. METHODS: A total of 40 Wistar female rats were used in this study. Animals were divided in groups of 5 rats. Groups IM, SM served as control groups. Groups I1, I2, I3 were used to study isoflurane and S1, S2, S3 for sevoflurane study. They were anesthetized 3 times, for 2h long, at 2 days interval with a concentration of: 1.5% isoflurane (I1, I2, I3) and 2% sevoflurane (S1, S2, S3). The oxygen supply throughout the anesthesia was 1LO2/min. Groups IM, IS, I1, S1 were sacrificed immediately after the last anesthesia. Groups I2, S2 were sacrificed 6h after the last anesthesia, and groups I3, S3, 24h post-anesthesia. Liver samples were harvested to highlight caspase-3 in apoptotic hepatocytes. RESULTS: Following isoflurane administration, there were less than 1% cells in apoptosis highlighted in rat livers from groups IM, I1 and I2. At 24h post-anesthesia (group I3), a small number of apoptotic hepatocytes was highlighted (around 3.23% cells in apoptosis), with a strictly periacinar disposition, randomly distributed in a small number of hepatic lobules. After sevoflurane administration, less than 1% apoptotic hepatocytes were identified at all control moments throughout the study. CONCLUSIONS: The results suggest that the anesthetics do not present a considerable hepatotoxicity. The comparative assessment of the two anesthetics shows that sevoflurane is superior to isoflurane.

Role of nitro-oxidative stress in the pathogenesis of experimental rat periodontitis.

BACKGROUND AND AIMS: Periodontitis is a common chronic adult condition that implicates oxidative damage to gingival tissue, periodontal ligament and alveolar bone. This study aimed at assessing the association between the nitro-oxidative stress and the periodontal tissues destructions in experimental rat periodontitis. METHODS: Periodontitis was induced in 15 male albino rats by repetitive lesions to the gingiva adjacent to the inferior incisors, performed daily, for 16 days. On D1, D3, D6, D8, and D16 the onset and evolution of periodontitis were monitored by clinical and histopathological examinations; blood was collected and serum nitro-oxidative stress was evaluated through total nitrites and nitrates, total oxidative status, total antioxidant capacity, and oxidative stress index. RESULTS: The results demonstrated that there was a graded and continuous increase in serum levels of total nitrites and nitrates, total oxidative status and oxidative stress index, which was consistent with the severity of periodontal destructions during periodontitis progression. However, total antioxidant capacity was not significantly influenced by the disease progression. CONCLUSIONS: In experimental rat periodontitis, the systemic nitro-oxidative stress was associated with the severity of periodontal destructions assessed clinically and histopathologically. Therefore, systemic nitro-oxidative stress parameters might be used as diagnostic tools in periodontitis.