Infection by Henneguya sp. (Myxozoa) in the bone tissue of the gill filaments of the Amazonian catfish Hypophthalmus marginatus (Siluriformes) / Infecção por Henneguya sp. (Myxozoa) em tecido ósseo do filamento branquial do bagre amazônico Hypophthalmus marginatus (Siluriformes)

This study describes aspects of the infection caused by the myxosporean genus Henneguya, which forms cysts in the bony portion of the gill filaments of Hypophthalmusmarginatus. Specimens of this catfish were acquired dead from artisanal fishermen near the town of Cametá, state of Pará, northern Brazil, between July 2011 and May 2012. They were transported in refrigerated containers to the Carlos Azevedo Research Laboratory at the Federal Rural University of Amazonia, in Belém, where analyses were performed. After confirmation of parasitism by the genus Henneguya, observation were made using optical and differential interference contrast (DIC) microscopy. The histological technique of embedment in paraffin was used. Ziehl-Neelsen staining was applied to the histological sections. Necropsy analyses on specimens of H. marginatus showed that 80% of them (40/50) had cysts of whitish coloration inside the bony portion of the gill filaments, filled with Henneguya spores. The present study found inflammatory infiltrate in the vicinity of the cysts. Furthermore, the special Ziehl-Neelsen staining technique made it possible to mark the Henneguya sp. cysts in the bone tissue and in spore isolates in the gill tissue structure. The descriptions of these histopathological findings show that this parasite is very invasive and causes damage to its host tissues.

O presente estudo descreve os aspectos da infecção causada por mixosporídio do gênero Henneguya, formando cistos na porção óssea dos filamentos branquiais de Hypophthalmus marginatus. Espécimes desse bagre foram adquiridos mortos de pescadores artesanais perto da cidade de Cametá, Estado do Pará, Brasil, entre julho de 2011 e maio de 2012. Os animais foram transportados em contêineres refrigerados até o Laboratório de Pesquisa Carlos Azevedo, na Universidade Federal Rural da Amazônia, em Belém, onde se procederam as análises. Após a constatação do parasitismo pelo gênero Henneguya, foi realizada a observação em microscópio óptico e em microscópio de contraste de interferência diferencial (DIC). Foi realizada técnica histológica de impregnação em parafina e coloração dos cortes histológicos em Ziehl-Neelsen. As análises necroscópicas dos espécimes de H. marginatus revelaram que 80% (40/50) destes apresentavam cistos esbranquiçados na porção óssea dos filamentos branquiais, repletos de esporos do gênero Henneguya. O presente estudo revelou infiltrado inflamatório nas imediações dos cistos. Além disso, a técnica especial de coloração em Ziehl-Neelsen possibilitou marcar os cistos de Henneguya sp. no tecido ósseo e de esporos isolados na estrutura de tecido branquial. As descrições desses achados histopatológicos mostram que esse parasita é muito invasivo e produz danos aos seus tecidos do hospedeiro.

Morfometría, planimetría y estereología en el hueso sesamoídeo distal en manos de equinos con y sin síndrome navicular / Morphometry, planimetry and stereology in the distal sesamoid bone in equine foot with and without navicular syndrome

El Síndrome Navicular (SN) es una patología claudicógena bilateral crónica, degenerativa y progresiva, que compromete alhueso sesamoídeo distal (HSD), labolsa podotroclear, ligamentosy a las superficies adyacentes al tendón del músculo flexor digitalprofundo en manos de equinos. La hipótesis de que las características morfológicas del HSD en la mano de equinos varían en aquellos que presentan SN fue evaluada en este estudio. Para determinar cambios morfológicos en el HSD en manos de equinos con SN se realizó un estudio morfométrico, planimétrico y estereológico. Fueron evaluados dos grupos: No Afectadas (n=11) y Síndrome Navicular (n=11). Se evaluaron variables tales como peso, volumen, mediciones lineales, área y parámetros estereológicos tales como densidad de número (NA), volumen (VV) y superficie (SV). Los resultados obtenidos indican que a pesar de existir un proceso patológico e inflamatorio en la región del HSD que induce cambios mesoscópicos y microscópicos atribuibles a SN, no lograrían modificar sus características macroscópicas.

Navicular Syndrome (NS) is a chronic, degenerative and progressive bilateral claudication pathology, compromising the distal sesamoid bone (DSB), the podotrochlear bursa, ligaments and adjacent surfaces of the tendon of the deep digital flexor muscle of equine foot. The hypothesis that morphological characteristics of HSB in hand of horses vary in those with SN was evaluated in this study. A study was carried out to determine the morphological changes in the DSB in 22 left foot of horses with NS. We realized morphometrical, planimetrical and stereological studies in two groups of horses feet: Not Affected (n=11) and Navicular Syndrome (n=11). The following variables were quantified: weight, volume, linear measurements, area and stereological parameters: densities of number (NA), volume (VV) and surface (SV). Results indicate that although there is a pathological and inflammatory process in the region of DSB which induces mesoscopic and microscopic changes attributable to SN, their gross morphological features were not modified.

Histiocitosis dendrocítica (histiocitosis de células de langerhans), manifestaciones orales y craneofaciales: reporte de tres casos / Dendrocitic histiocytosis (langerhans cell histiocytosis), oral and craniofacial manifestations: report of three cases

La Histiocitosis de células de Langerhans (HCL) corresponde a una proliferación anormal de células dendríticas, de tipo clonal, cuyo espectro clínico general incluye compromiso de la piel y las mucosas, las uñas, el hueso, la médula ósea, el hígado, el bazo, linfonodos, el pulmón, el tracto gastrointestinal inferior, el sistema endocrino y el sistema nervioso central. En este trabajo presentamos tres casos de la enfermedad, con manifestaciones orales y craneofaciales, analizadas desde el punto de vista clínico (examen extra e intra oral), imagenológico (tomografías computadas) e histopatológico (expresión de marcador específico CD1a). Dos casos fueron clasificados como HCL de presentación aguda diseminada y uno como presentación crónica. Los pacientes fueron tratados oportunamente con quimioterapia según el protocolo del Programa Infantil Nacional de Drogas Antineoplásicas.

The Langerhans cell histiocytosis (LCH) corresponds to an abnormal proliferation of dendritic cells, clonal type, which usually involves compromise of skin and mucous membranes, nails, bone, bone marrow, liver, spleen, lymph nodes, lung, lower gastrointestinal tract, endocrine system and the central nervous system. We present three cases of the disease, with oral and craniofacial manifestations, analyzed from the clinical perspective (intra and extra oral exam), imaging (CT scans) and histopathological (specific marker CD1a expression). Two cases were classified as acute disseminated LCH presentation and one as a chronic disease. Patients were treated with chemotherapy timely according to the protocol of the National Child Program of Antineoplastic Drugs.

Bone disease in thyrotoxicosis.

Thyrotoxicosis, a clinical syndrome characterized by manifestations of excess thyroid hormone, is one of the commonly-recognised conditions of the thyroid gland. Thyrotoxicosis causes acceleration of bone remodelling and though it is one of the known risk factors for osteoporosis, the metabolic effects of thyroxine on bone are not well discussed. Studies show that thyroid hormones have effects on bone, both in vitro and in vivo. Treatment of thyrotoxicosis leads to reversal of bone loss and metabolic alterations, and decreases the fracture risk. There are limited studies in India as to whether these changes are fully reversible. In this review we discuss about the effects of thyrotoxicosis (endogenous and exogenous) on bone and mineral metabolism, effects of subclinical thyrotoxicosis on bone and mineral metabolism and effects of various forms of treatment in improving the bone mineral density in thyrotoxicosis.

Tumor odontogênico queratocístico em mandíbula: relato de caso clínico com acompanhamento de dois anos / Keratocyst odontogenic tumour in mandible: a case report with two years follow-up

O Tumor Odontogênico Queratocístico é uma lesão óssea benigna de natureza agressiva,com altas taxas de recidiva. A lesão é localizada frequentemente na região posterior do corpo e no ramo da mandibula. Radiograficamente apresenta-se com imagem radiotransparente uni ou multilocular. A tomografia computadorizada pode auxiliar no planejamento cirúrgico quando se pretende avaliar a extensão e limites anatômicos da lesão. Possui como característica histo¬lógica a presença de epitélio estratificado escamoso, na maioria dos casos paraqueratinizado. O tratamento usual é a enucleação com ou sem curetagem ou marsupialização. O objetivo deste trabalho será apresentar um caso clínico de Tumor Odontogênico Queratocístico em paciente q,Q gênero feminino de 39 anos de idade no qual foi realizado planejamento cirúrgico que consistiu em enucleação cirúrgica seguida de curetagem da loja cirúrgica. Após dois anos de acompanha¬mento clínico e radiográfico não houve recidiva da lesão.

The keratocyst odontogenic tumor is a benign intraosseous tumor, with an aggressive natu¬re and shows high recurrence rates. The lower jaw is the most commom si te of occurrence, es¬pecially in the posterior body and ramus regions. Radiographically it is radiolucency and it may be solitary or multiple. The computorized tomography provides confidence in the diagnois and dental planning. Histologically, keratocyst odontogenic tumor presents a characteristic lining of parakeratinized stratified squamous epithelium. The usual treatment includes enucleation, with or without curettage, or marsupialization. The objective of this report is to presents a case of patient which keratocyst odontogenic tumor and the treatment consisted in excisional bipsy and curettage. The clinical and radiography findings after 2years demonstrated absence of recu rrent lesion.

Gingival fibromatosis with hemi-osseous hyperplasia of jaws, focal maxillary viral papillomatosis of gingiva, fissured tongue and congenitally missing anterior teeth: A case report and surgical management of a new syndrome.

Gingival fibromatosis is characterized by fibrotic enlargement of the gingiva that can occur as inherited or sporadic form. Inherited form can be an isolated trait or as a component of a syndrome. This article reports a 35 year old male patient affected by gingival fibromatosis associated with hemiosseous hyperplasia of mandible, maxilla, and zygoma on the right side, viral papillomatosis of maxillary anterior gingiva, fissured tongue and congenitally missing anterior teeth. The patient was subjected to phase I and phase II periodontal therapy. There was no evidence of recurrence of the enlargement after one year but the papillomatosis recurred. Gingival fibromatosis has been reported to be associated with various other abnormalities but not with those described in our case. This observation raises the possibility that the coexistence of these entities in our case may represent a new syndrome.

Establishment of Efficacy and Safety Assessment of Human Adipose Tissue-Derived Mesenchymal Stem Cells (hATMSCs) in a Nude Rat Femoral Segmental Defect Model

Human adipose tissue-derived mesenchymal stem cell (hATMSC) have emerged as a potentially powerful tool for bone repair, but an appropriate evaluation system has not been established. The purpose of this study was to establish a preclinical assessment system to evaluate the efficacy and safety of cell therapies in a nude rat bone defect model. Segmental defects (5 mm) were created in the femoral diaphyses and transplanted with cell media (control), hydroxyapatite/tricalcium phosphate scaffolds (HA/TCP, Group I), hATMSCs (Group II), or three cell-loading density of hATMSC-loaded HA/TCP (Group III-V). Healing response was evaluated by serial radiography, micro-computed tomography and histology at 16 weeks. To address safety-concerns, we conducted a GLP-compliant toxicity study. Scanning electron microscopy studies showed that hATMSCs filled the pores/surfaces of scaffolds in a cell-loading density-dependent manner. We detected significant increases in bone formation in the hATMSC-loaded HA/TCP groups compared with other groups. The amount of new bone formation increased with increases in loaded cell number. In a toxicity study, no significant hATMSC-related changes were found in body weights, clinical signs, hematological/biochemical values, organ weights, or histopathological findings. In conclusion, hATMSCs loaded on HA/TCP enhance the repair of bone defects and was found to be safe under our preclinical efficacy/safety hybrid assessment system.

Proceso estiloides elongado: criterios diagnósticos y diagnóstico diferencial: a propósito de un caso / Elongated styloid process: diagnostic criteria and differential diagnosis: a case review

La elongación del proceso estiloides puede presentarse como una entidad patológica en el territorio craneocervical. Existe controversia en relación a los criterios para su diagnóstico, así como sus diagnósticos diferenciales. En el presente reporte se relata el caso de una paciente de 45 años con lumbagos crónicos, cefalea intermitente, dolor cervical y articular agudo, sin historia de quirúrgica o traumática craneocervical. Radiográficamente, destaca la elongación bilateral del proceso estiloides, determinando un diagnóstico presuntivo de Síndrome de Eagle. Se preconiza que los pacientes deben haber sido sometidos a tonsilectomía o trauma para padecer esta patología, condición ausente en este caso. La correcta discriminación de los signos y síntomas permite diferenciar la patología como síndrome estilohioideo. El presente reporte entrega los criterios a considerar en un paciente con el proceso estiloides elongado asociado a patología, con el fin de canalizar esa información hacia un diagnóstico certero.

The elongation of the styloid process may occur as a pathologic entity in the craniocervical area. There is controversy regarding the criteria for its diagnosis and its differential diagnosis. In this report we present the case of a 45 year old female with chronic low back pain, intermittent headache, neck pain and acute articular, no history of surgical or traumatic in the craniocervical area. Radiographically, bilateral elongation of the styloid process were detected, determining a presumptive diagnosis of Eagle syndrome. It requires that patients must have undergone tonsillectomy or trauma to suffer this disease, a condition absent in this case. The correct discrimination of the signs and symptoms distinguish this condition as stylohyoid syndrome. This report delivers the criteria to consider in a patient with elongated styloid process associated with pathology, to use that information and give an accurate diagnosis.

Recomendaciones para el procesamiento de especímenes en patología ósea. Experiencia del Instituto Nacional de Cancerología de Colombia / Recommendations for processing bone specimens in pathology: practice at the National Cancer Institute of Colombia

El procesamiento y estudio de la patología ósea es un reto diario para el patólogo debido a su complejidad diagnóstica. Las muestras con componente óseos requieren procedimientos como la manipulación de grandes piezas quirúrgicas y su descalcificación para obtener tejidos evaluables al microscopio. Lo anterior retarda el reporte patológico 20 a 30 días demorando el diagnóstico definitivo y el inicio de tratamiento o la evaluación de la respuesta a terapias neoadyudantes. Se desarrolló una guía de procesamiento de especímenes óseos que reduce los tiempos hasta el diagnóstico definitivo en 2 a 3 días para biopsias y en 13 a 15 días para amputaciones y resecciones en bloque. Presentamos una guía práctica, rápida y reproducible.

The processing and study of bone biopsias represent a challenge for the pathologist due to the complexity of diagnosis. Bone samples require special processing such as the manipulation and decalcification of big surgical specimens in order to obtain evaluable tissue under the microscope. Consequently, the pathology is performed in about 20-30 days delaying the final diagnosis, the beginning of treatment, or the evaluation of neoadyuvant therapy response. A practical guideline for bone specimen processing was developed reducing layout time for final diagnosis around 2-3 days for biopsies and 13-15 days for surgical specimens. A practical, nimble, and reliable guideline is presented.

Effects of folk medicinal plant extract Ankaferd Blood Stopper® on early bone healing

OBJECTIVE: Several haemostatic agents are available for clinical use. Ankaferd Blood Stopper® (ABS), a mixture of five medicinal plant extracts, has been used historically as a haemostatic agent. The aim of this in vivo study was to investigate the effects of ABS on early bone healing using a rat tibia defect model. MATERIAL AND METHODS: Sixteen male Wistar rats were randomized into two groups of 8 animals each. After deep anesthesia with ketamine, bone defects (3 mm diameter and 2 mm deep) were created in the right and left tibiae of all animals and either treated with 1 cc of ABS (Group 1) or left untreated (Group 2; control). Surgical areas were closed primarily. The animals were sacrificed on the 7th postoperative day and bone samples were collected from the tibias. The samples were examined histopathologically for infection, necrosis, fibrosis, new bone formation and foreign body reaction. The histomorphometric results were analyzed statistically by the chi square test, with the level of significance set at p<0.05. RESULTS: Significant differences were found in both groups in terms of inflammation, necrosis and new bone formation (p=0.001, p=0.0001, p=0.001). No foreign body reaction was observed in the experimental group. ABS application decreased fibrosis in the experimental group, but there were no statistically significant differences from the control group. CONCLUSIONS: Histopathologically, it was observed that the application of ABS decreased the occurrence of inflammation and necrosis, while increasing new bone formation in early bone healing period. Further in vitro and in vivo studies are necessary for evaluating the benefits and possible adverse effects of the application of this herbal product on wound healing.

Displasia fibrosa: a doença e a imagem / Fibrous dysplasia: the disease and imageologic findings

A displasia fibrosa é uma lesão benigna que afeta um ou mais ossos, caracterizada pela substituição gradativa de tecido ósseo por tecido fibra-ósseo. Radiograficamente, as lesões apresentam-se com o aspecto de "vidro despolido" ou de "casca de laranja". A tomografia óssea é o método ideal para estabelecimento de diagnóstico adequado e acompanhamento de pacientes com esta patologia. Este artigo relata um caso clínico em que a displasia fibrosa foi diagnosticada a partir da documentação radiográfica com a finalidade de colocação de implantes dentários. O objetivo desse relato é apresentar os aspectos clínicos e imaginológicos da displasia fibrosa e alertar o cirurgião-dentista para a identificação desta patologia na rotina diária.

Fibrous dysplasia is a benign disease that affects one ar more banes, characterized by the gradual replacement of the normal bane for a fibro-osseous tissue. Lesions are observed radiographically with a "ground qlass" appearance or orange peel. Computed tomography images proved to be the best way for diagnosis and for the evaluation of fibrous dysplasia lesions. This is a case of patient which fibrous dysplasia had been diagnosed during documentation for implants replacement. The objective of this report is to alert the dentist to make the identifications of this lesion in daily routine, presenting the clinic and imageologic findings of this lesion.

Síndrome de Eagle bilateral: reporte de un caso / Bilateral Eagle´s syndrome: a case report

El síndrome de Eagle se caracteriza por la elongación del proceso estiloides y/o la calcificación de los ligamentos presentes en él, los que provienen embriológicamente del cartílago del segundo arco faríngeo (Reichert). Esto produce dolor intenso en la región craneocervical y limitación de los movimientos cervicales. Generalmente es confundido con otras patologías, tales como disfunciones en la articulación témporomandibular. El diagnóstico de esta entidad es realizado a través de los correctos exámenes clínico y radiográfico. En este trabajo se reporto un caso y se hace una breve revisión de la literatura, mostrando la importancia del correcto diagnóstico de esta entidad y su sintomatología.

The Eagle's syndrome is characterized by the elongation of the styloid process and/or their ligaments calcification, which come embryologically from Reichert's cartilage or second branchial arch. This produces pain in thecraniocervical region and limitation of cervical movements. Generally is confused with other dysfunctions, such as temporomandibular joint dysfunction. The diagnosis of this entity is by the correct clinical and radiographic exam. In this work is done reporting a case and makes a brief review of the literature, showing the importance of this entity correct diagnosis and their symptoms.

Influence of simvastatin on bone regeneration of tibial defects and blood cholesterol level in rats

The purpose of this study was to evaluate the effects of simvastatin, by oral or subcutaneous administration, on tibial defects regeneration and blood cholesterol level in rats. A surgical defect was made on the right tibia of 40 male animals assigned to 4 groups (n=10), based on two routes of administration and on the use or not of simvastatin: subcutaneous injection of simvastatin (7 mg/kg) (group AT) or only the vehicle of drug suspension (group AC), above the defect area, for 5 days; and 20 mg/kg of simvastatin macerated on water (group BT) or only water (group BC), orally, daily, during the whole observation period. The animals were sacrificed after 15 or 30 days, when blood samples were analyzed to check plasma cholesterol levels. Tibiae were removed and, after decalcification and routine laboratorial processing, histological and histomorphometrical analyses were carried out. ANOVA was used for statistical analysis at 5 percent signficance level. The histological and histomorphometrical analyses showed significant differences only between the experimental periods (p<0.05). Animals sacrificed after 30 days showed better bone repair (p<0.05). There was no statistically significant difference (p>0.05) for blood cholesterol levels between the groups. In conclusion, simvastatin administration either orally or subcutaneously did not improve bone repair of experimental tibial defects and did not alter blood cholesterol levels in rats.

Este estudo avaliou a influência da sinvastatina, administrada por via oral ou subcutânea, na reparação de defeitos ósseos em tíbia e nos níveis de colesterol sangüíneo, em ratos. Foram realizados defeitos cirúrgicos nas tíbias direitas de 40 ratos machos, distribuídos em 4 grupos (n=10), tomando-se como base duas vias de administração e o uso ou não de sinvastatina: injeção subcutânea de sinvastatina (7 mg/kg) (grupo AT) ou apenas do veículo de suspensão da droga (grupo AC), sobre a região do defeito, durante 5 dias; 20 mg/kg de sinvastatina (grupo BT) ou água filtrada (grupo BC) via oral, diariamente, durante todo o período de observação. Os animais foram sacrificados após 15 ou 30 dias, quando amostras sangüíneas foram colhidas para análise do nível de colesterol. As tíbias foram removidas e, após descalcificação e procedimentos laboratoriais de rotina, procedeu-se à análise histológica e histomorfométrica. Para avaliação estatística utilizou-se ANOVA com nível de significância de 5 por cento. As análises histomorfométrica e histológica mostraram diferença entre os grupos apenas com relação ao período experimental (p<0,05), apresentando os melhores resultados os animais sacrificados em 30 dias (p<0,05). Quanto ao nível de colesterol sangüíneo, não houve diferença estatisticamente significante entre os grupos analisados (p>0,05). Concluiu-se que, nas condições utilizadas, a sinvastatina, administrada via oral ou subcutânea, não exerceu efeito estimulador sobre o reparo ósseo de defeitos experimentais em tíbias de ratos e não alterou os níveis de colesterol sangüíneo.

Análise imaginológica dos osteomas / Osteomas imaging evaluation

Osteomas são tumores osteoblásticos benignos, compostos de osso maduro, compacto ou medular. Possuem etiologia aparentemente desconhecida, apesar de existirem teorias para explicar sua aparição. São essencialmente restritos ao esqueleto craniofacial e raramente encontrados em outros ossos, sendo, geralmente, diagnosticados ao acaso durante tomadas radiográficas de rotina nessa região. Seu crescimento lento e com ausência de sintomatologia dolorosa dificulta ainda mais o diagnóstico precoce. Existem variações entre autores quanto à forma de abordagem e a técnica utilizada para intervenção, contudo, a indicação de tratamento é a remoção cirúrgica. Este trabalho tem como finalidade fazer uma breve revista de literatura e demonstrar algumas imagens de diversos osteomas

Displasia cleidocraniana: relato de caso clínico / Cleidocranial dysplasi: case report

Paciente de 24 anos, sexo feminino, portadora de sinais característicos da Displasia Cleidocraniana foi submetida a exames clínico e radiográfico, os quais evidenciaram anormalidades na aparência física e constituição esquelética da mesma, confirmando a suspeita diagnóstica. O tratamento proposto foi excisão cirúrgica de numerosos dentes inclusos, para viabilizar posterior reabilitação protética. A peça cirúrgica foi encaminhada para exame histopatológico, para avaliar a presença de lesão cística e possíveis distúrbios na constituição morfológica dos dentes removidos. Diante da raridade desta síndrome, este artigo objetiva relatar os aspectos gerais da doença e a terapêutica utilizada

Bilateral Transverse (Bowdler) Fibular Spurs with Hypophosphatasia in an Adolescent Girl

Hypophosphatasia is a clinically heterogeneous inheritable disorder characterized by defective bone mineralization and the deficiency of serum and tissue liver/bone/kidney alkaline phosphatase activities. Due to the mineralization defect of the bones, various skeletal findings can be radiologically observed in hypophosphatasia. Bowing and Bowdler spurs of long bones are the characteristic findings. The Bowdler spurs reported on in the previous pertinent literature were observed in the perinatal aged patients and these lesions have rarely involved adolescents. We herein report on a 14-year-old girl with fibular Bowdler spurs.

Efeito da associação hipertireoidismo-castração no osso de ratas adultas / Bone effects of the association hyperthyroidism-castration of adult female rats

Foi estudada a relação tireóide-gônadas e sua influência sobre a morfologia óssea de ratas Wistar, com cinco meses de idade, castradas e induzidas ao hipertireoidismo ou mantidas em eutireoidismo por período de 30, 60 e 90 dias. Ratas não castradas foram mantidas nas mesmas condições e serviram como controle. Ao final de cada período, foram determinadas as concentrações plasmáticas de T4 livre, progesterona e estradiol. Os ossos de cada grupo foram submetidos às análises radiológica e histológica. O hipertireoidismo nas ratas não castradas levou à alteração da morfologia do osso, variável ao longo do período experimental, conduzindo, aos 60 dias, à perda de osso trabecular por aumento da reabsorção óssea. Aos 90 dias não houve perda óssea porque o aumento da reabsorção foi acompanhado por maior aposição óssea. Nas ratas eutireóideas castradas, a diminuição dos níveis de progesterona inibiu a aposição óssea, causando, aos 30 dias, pequena perda do osso trabecular das vértebras lombares e do osso alveolar, que se intensificou aos 60 e 90 dias, atingindo também o osso cortical. A administração de tiroxina nas ratas castradas reduziu a osteopenia decorrente da castração aos 60 dias, mas não aos 90 dias, quando a perda óssea foi mais extensa. Conclui-se que o hipoprogesteronismo e o hipoestrogenismo alteram o metabolismo ósseo e que a resposta do osso ao hipertireoidismo depende do perfil plasmático dos esteróides sexuais, do tempo de exposição e da configuração do tecido ósseo.

Fibroma ossificante juvenil agressivo recidivante / Aggressive recurrent juvenile ossifying fibroma

O fibroma ossificante juvenil é um neoplasma óssseo benigno, porém localmente agressivo e com altos índices de recidiva. O presente caso é de uma paciente do sexo feminino que apresentou recidiva de lesão e que é bastante peculiar por acometer unicamente a mandíbula, fato este incomum na maioria dos casos desta lesão. Ressalta-se portanto a necessidade de um manejo cuidadoso destes pacientes no intuito de evitar sucessivas recidivas das lesões