Oxytocin promotes bone formation during the alveolar healing process in old acyclic female rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ectopic ossification presenting as osteoid metaplasia in a salivary mucocele in a Shih Tzu dog

Background: Salivary mucocele is an accumulation of saliva in a single or multiloculated cavity lined by connective tissue that is contiguous to a salivary gland-duct complex and is the most common condition affecting the salivary glands in dogs. Occasionally, different types of metaplastic lesions, such as squamous and osseous metaplasia - which are rare lesions in animals - can be observed in association with salivary mucocele.Case presentation: A right facial enlargement was suddenly observed in a 4-year-old non-spayed female Shih-Tzu dog. The lesion presented itself as a soft and fluctuant mass located in the right side of the face near to the neck. Histologically, the mass consisted of a cavitary formation without an epithelial lining. Additionally, microscopic examination revealed the presence of osteoid-producing cells which gave rise to areas of bone formation, probably induced by irritation due to the presence sialoliths. Such cells and bone formations were also present in the cavity wall, consequently leading us to classify the condition as a salivary mucocele with osseous metaplasia.Conclusions: In the present case, the pathogenesis was probably associated with the presence of sialoliths, which can behave as etiological agents for the metaplastic lesion. The occurrence of osteoid metaplasia is a rare peculiar condition in the canine salivar y gland, and due to the rarity and lack of information about this specific disease, no clinical data can yet be associated with the development of salivary mucocele with osseous metaplasia in dogs.

Biological response to wollastonite doped α-tricalcium phosphate implants in hard and soft tissues in rats

The biological response following subcutaneous and bone implantation of β-wollastonite(β-W)-doped α-tricalcium phosphate bioceramics in rats was evaluated. Tested materials were: tricalcium phosphate (TCP), consisting of a mixture of α- and β-polymorphs; TCP doped with 5 wt. % of β-W (TCP5W), composed of α-TCP as only crystalline phase; and TCP doped with 15 wt. % of β-W (TCP 15), containing crystalline α-TCP and β-W. Cylinders of 2×1 mm were implanted in tibiae and backs of adult male Rattus norvegicus, Holtzman rats. After 7, 30 and 120 days, animals were sacrificed and the tissue blocks containing the implants were excised, fixed and processed for histological examination. TCP, TCP5W and TCP15W implants were biocompatible but neither bioactive nor biodegradable in rat subcutaneous tissue. They were not osteoinductive in connective tissue either. However, in rat bone tissue β-W-doped α-TCP implants (TCP5W and TCP 15W) were bioactive, biodegradable and osteoconductive. The rates of biodegradation and new bone formation observed for TCP5W and TCP15W implants in rat bone tissue were greater than for non-doped TCP.

Reconstruction of the anterior wall of the frontal sinus using bovine bone matrix: histological study with monkeys

The purpose of this study was to evaluate the repair process in the reconstruction of the anterior wall of the frontal sinus of monkeys with bovine bone matrix. Four adult Cebus apella monkeys underwent an ostectomy of the anterior wall of the frontal sinus. The frontal sinus mucosa and the nasofrontal duct were not manipulated. Reconstruction occurred with implants of bovine bone matrix laminae measuring 2.0 x 2.5 cm and 0.4 mm thick, stabilized under pressure in the lateral wall of the frontal sinus. The monkeys were sacrificed over a period of 150 days and routine laboratory procedures were followed for hematoxylin-eosin staining and histologic evaluation of the specimens. Neoformed bone tissue was observed in contact with the frontal sinus mucosa and the bovine bone matrix. The frontal sinus mucosa remained whole without fibrous tissue or cystic formations. There was no occurrence of cellularization as well as revascularization of the bovine bone matrix, though it has permitted bone conduction on this surface. It was possible to conclude that the demineralized bovine bone matrix was biotolerable, being incorporated into the bone without the presence of inflammatory cells with characteristics of inertness and antigenicity and behaved as an osteoconductive material.

Exploratory Study Of The Effect Of Lifestyle Counselling On Bone Mineral Density And Body Composition In Users Of The Contraceptive Depot-medroxyprogesterone Acetate.

To compare variations in bone mineral density (BMD) and body composition (BC) in depot-medroxyprogesterone acetate (DMPA) users and nonusers after providing counselling on healthy lifestyle habits. An exploratory study in which women aged 18 to 40 years participated: 29 new DMPA users and 25 new non-hormonal contraceptive users. All participants were advised on healthy lifestyle habits: sun exposure, walking and calcium intake. BMD and BC were assessed at baseline and 12 months later. Statistical analysis included the Mann-Whitney test or Student's t-test followed by multiple linear regression analysis. Compared to the controls, DMPA users had lower BMD at vertebrae L1 and L4 after 12 months of use. They also had a mean increase of 2 kg in total fat mass and an increase of 2.2% in body fat compared to the non-hormonal contraceptive users. BMD loss at L1 was less pronounced in DMPA users with a calcium intake ≥ 1 g/day compared to DMPA users with a lower calcium intake. DMPA use was apparently associated with lower BMD and an increase in fat mass at 12 months of use. Calcium intake ≥ 1 g/day attenuates BMD loss in DMPA users. Counselling on healthy lifestyle habits failed to achieve its aims.

Focal Osteoporotic Bone Marrow Defect Mimicking A Mandibular Cystic Lesion.

An unusual presentation of a focal osteoporotic bone marrow defect (FOBMD) of the mandible mimicking a cystic lesion is documented. A definitive diagnosis could be established only on the basis of the histopathologic evaluation. A 66-year-old Brazilian woman was referred by her dentist for well-defined radiolucency of the mandibular molar region suggesting a cystic lesion of odontogenic origin. The computed tomography scan confirmed that the lesion did not affect the corticals. The biopsy confirmed the diagnosis of FOBMD. The diagnostic difficulty in the current case is obvious, because FOBMD, usually exhibiting an ill-defined radiolucency, is seldom suspected preoperatively when a differential diagnosis is considered for focal well-defined radiolucent areas in the jaws.

Discovery Of A Rare Pterosaur Bone Bed In A Cretaceous Desert With Insights On Ontogeny And Behavior Of Flying Reptiles.

A pterosaur bone bed with at least 47 individuals (wing spans: 0.65-2.35 m) of a new species is reported from southern Brazil from an interdunal lake deposit of a Cretaceous desert, shedding new light on several biological aspects of those flying reptiles. The material represents a new pterosaur, Caiuajara dobruskii gen. et sp. nov., that is the southermost occurrence of the edentulous clade Tapejaridae (Tapejarinae, Pterodactyloidea) recovered so far. Caiuajara dobruskii differs from all other members of this clade in several cranial features, including the presence of a ventral sagittal bony expansion projected inside the nasoantorbital fenestra, which is formed by the premaxillae; and features of the lower jaw, like a marked rounded depression in the occlusal concavity of the dentary. Ontogenetic variation of Caiuajara dobruskii is mainly reflected in the size and inclination of the premaxillary crest, changing from small and inclined (∼ 115°) in juveniles to large and steep (∼ 90°) in adults. No particular ontogenetic features are observed in postcranial elements. The available information suggests that this species was gregarious, living in colonies, and most likely precocial, being able to fly at a very young age, which might have been a general trend for at least derived pterosaurs.

Influence Of Delivery Method On Neuroprotection By Bone Marrow Mononuclear Cell Therapy Following Ventral Root Reimplantation With Fibrin Sealant.

The present work compared the local injection of mononuclear cells to the spinal cord lateral funiculus with the alternative approach of local delivery with fibrin sealant after ventral root avulsion (VRA) and reimplantation. For that, female adult Lewis rats were divided into the following groups: avulsion only, reimplantation with fibrin sealant; root repair with fibrin sealant associated with mononuclear cells; and repair with fibrin sealant and injected mononuclear cells. Cell therapy resulted in greater survival of spinal motoneurons up to four weeks post-surgery, especially when mononuclear cells were added to the fibrin glue. Injection of mononuclear cells to the lateral funiculus yield similar results to the reimplantation alone. Additionally, mononuclear cells added to the fibrin glue increased neurotrophic factor gene transcript levels in the spinal cord ventral horn. Regarding the motor recovery, evaluated by the functional peroneal index, as well as the paw print pressure, cell treated rats performed equally well as compared to reimplanted only animals, and significantly better than the avulsion only subjects. The results herein demonstrate that mononuclear cells therapy is neuroprotective by increasing levels of brain derived neurotrophic factor (BDNF) and glial derived neurotrophic factor (GDNF). Moreover, the use of fibrin sealant mononuclear cells delivery approach gave the best and more long lasting results.

Long-term Spinal Ventral Root Reimplantation, But Not Bone Marrow Mononuclear Cell Treatment, Positively Influences Ultrastructural Synapse Recovery And Motor Axonal Regrowth.

We recently proposed a new surgical approach to treat ventral root avulsion, resulting in motoneuron protection. The present work combined such a surgical approach with bone marrow mononuclear cells (MC) therapy. Therefore, MC were added to the site of reimplantation. Female Lewis rats (seven weeks old) were subjected to unilateral ventral root avulsion (VRA) at L4, L5 and L6 levels and divided into the following groups (n = 5 for each group): Avulsion, sealant reimplanted roots and sealant reimplanted roots plus MC. After four weeks and 12 weeks post-surgery, the lumbar intumescences were processed by transmission electron microscopy, to analyze synaptic inputs to the repaired α motoneurons. Also, the ipsi and contralateral sciatic nerves were processed for axon counting and morphometry. The ultrastructural results indicated a significant preservation of inhibitory pre-synaptic boutons in the groups repaired with sealant alone and associated with MC therapy. Moreover, the average number of axons was higher in treated groups when compared to avulsion only. Complementary to the fiber counting, the morphometric analysis of axonal diameter and g ratio demonstrated that root reimplantation improved the motor component recovery. In conclusion, the data herein demonstrate that root reimplantation at the lesion site may be considered a therapeutic approach, following proximal lesions in the interface of central nervous system (CNS) and peripheral nervous system (PNS), and that MC therapy does not further improve the regenerative recovery, up to 12 weeks post lesion.

[factors That Influence Bone Mass Of Healthy Children And Adolescents Measured By Quantitative Ultrasound At The Hand Phalanges: A Systematic Review].

To analyze the main factors that influence bone mass in children and teenagers assessed by quantitative ultrasound (QUS) of the phalanges. A systematic literature review was performed according to the PRISMA method with searches in databases Pubmed/Medline, SciELO and Bireme for the period 2001-2012, in English and Portuguese languages, using the keywords: children, teenagers, adolescent, ultrasound finger phalanges, quantitative ultrasound of phalanges, phalangeal quantitative ultrasound. 21 articles were included. Girls had, in QUS, Amplitude Dependent Speed of Sound (AD-SoS) values higher than boys during pubertal development. The values of the parameters of QUS of the phalanges and dual-energy X-ray Absorptiometry (DXA) increased with the increase of the maturational stage. Anthropometric variables such as age, weight, height, body mass index (BMI), lean mass showed positive correlations with the values of QUS of the phalanges. Physical activity has also been shown to be positively associated with increased bone mass. Factors such as ethnicity, genetics, caloric intake and socioeconomic profile have not yet shown a conclusive relationship and need a larger number of studies. QUS of the phalanges is a method used to evaluate the progressive acquisition of bone mass during growth and maturation of individuals in school phase, by monitoring changes that occur with increasing age and pubertal stage. There were mainly positive influences in variables of sex, maturity, height, weight and BMI, with similar data when compared to the gold standard method, the DXA.

Low Bone Mass In Human Immunodeficiency Virus-infected Climacteric Women Receiving Antiretroviral Therapy: Prevalence And Associated Factors.

Low bone mineral density (BMD) has been found in human immunodeficiency virus (HIV)-infected patients; however, data on associated factors remain unclear, specifically in middle-aged women. This study aims to evaluate factors associated with low BMD in HIV-positive women. In this cross-sectional study, a questionnaire was administered to 206 HIV-positive women aged 40 to 60 years who were receiving outpatient care. Clinical features, laboratory test results, and BMD were assessed. Yates and Pearson χ(2) tests and Poisson multiple regression analysis were performed. The median age of women was 47.7 years; 75% had nadir CD4 T-cell counts higher than 200, and 77.8% had viral loads below the detection limit. There was no association between low BMD at the proximal femur and lumbar spine (L1-L4) and risk factors associated with HIV infection and highly active antiretroviral therapy. Poisson multiple regression analysis showed that the only factor associated with low BMD at the proximal femur and lumbar spine was postmenopause status. Low BMD is present in more than one third of this population sample, in which most women are using highly active antiretroviral therapy and have a well-controlled disease. The main associated factor is related to estrogen deprivation. The present data support periodic BMD assessments in HIV-infected patients and highlight the need to implement comprehensive menopausal care for these women to prevent bone loss.

Vertical Bone Measurements From Cone Beam Computed Tomography Images Using Different Software Packages.

This article aimed at comparing the accuracy of linear measurement tools of different commercial software packages. Eight fully edentulous dry mandibles were selected for this study. Incisor, canine, premolar, first molar and second molar regions were selected. Cone beam computed tomography (CBCT) images were obtained with i-CAT Next Generation. Linear bone measurements were performed by one observer on the cross-sectional images using three different software packages: XoranCat®, OnDemand3D® and KDIS3D®, all able to assess DICOM images. In addition, 25% of the sample was reevaluated for the purpose of reproducibility. The mandibles were sectioned to obtain the gold standard for each region. Intraclass coefficients (ICC) were calculated to examine the agreement between the two periods of evaluation; the one-way analysis of variance performed with the post-hoc Dunnett test was used to compare each of the software-derived measurements with the gold standard. The ICC values were excellent for all software packages. The least difference between the software-derived measurements and the gold standard was obtained with the OnDemand3D and KDIS3D (-0.11 and -0.14 mm, respectively), and the greatest, with the XoranCAT (+0.25 mm). However, there was no statistical significant difference between the measurements obtained with the different software packages and the gold standard (p> 0.05). In conclusion, linear bone measurements were not influenced by the software package used to reconstruct the image from CBCT DICOM data.

Surgical treatment of patients with cervical spinal cord injury by anterior approach using bone graft

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Análise transversal da estrutura óssea e parâmetros hematológicos em futebolistas profissionais = : Cross-sectional analysis of bone structure and hematological parameters in professional soccer players

Universidade Estadual de Campinas. Faculdade de Educação Física

Bone response to biosilicates® with different crystal phases

The aim of this study was to investigate the histological and histomorphometrical bone response to three Biosilicates with different crystal phases comparing them to Bioglass®45S5 implants used as control. Ceramic glass Biosilicate and Bioglass®45S5 implants were bilaterally inserted in rabbit femurs and harvested after 8 and 12 weeks. Histological examination did not revealed persistent inflammation or foreign body reaction at implantation sites. Bone and a layer of soft tissue were observed in close contact with the implant surfaces in the medullary canal. The connective tissue presented few elongated cells and collagen fibers located parallel to implant surface. Cortical portion after 8 weeks was the only area that demonstrated significant difference between all tested materials, with Biosilicate 1F and Biosilicate 2F presenting higher bone formation than Bioglass®45S5 and Biosilicate® vitreo (p=0.02). All other areas and periods were statistically non-significant (p>0.05). In conclusion, all tested materials were considered biocompatible, demonstrating surface bone formation and a satisfactory behavior at biological environment.