Maria das Graças Farias Pinto

Bisphosphonates: Pharmacokinetics, bioavailability, mechanisms of action, clinical applications in children, and effects on tooth development

Bisphosphonates (BPs) avidly bind to calcium crystals and inhibit osteoclastic bone resorption, making them useful for treatment of skeletal disorders such as osteoporosis, Pagets disease, osteogenesis imperfecta and metastatic bone diseases. BPs therapeutically act by causing toxic effects on osteoclasts or interfering with specific intracellular pathways in those cells. BPs that possess nitrogen in their composition are called nitrogen-containing BPs (NBPs) and include alendronate, pamidronate, risedronate, ibandronate, and zoledronate. Simple BPs or non-NBPs do not have nitrogen in their composition, include etiodronate and clodronate, and were the first to be tested in animals and clinically used. Because BPs may be administered to pregnant women or children during deciduous and permanent teeth development, it is expected that they might disturb tooth eruption and development. A review of current literature on pharmacokinetics, bioavailability, mechanisms of action, and clinical applications of BPs in children, and their effects on tooth eruption and development is presented.

Características anatômicas do plexo braquial de tamanduá-mirim (Tamandua tetradactyla Linnaeus, 1758)

The aim of this study was to identify the origin, composition and the nerves from the brachial plexus of the lesser anteater. Two cadavers were given by the Wild Animals Screening Center (CETAS Chico Mendes), Salvador city, Brazil and the execution of the project was authorized by the System of Authorization and Information in Biodiversity (SISBIO – IBAMA) n°20268-1 (29/05/2009). The results were described, schematized and photographed, and the anatomic terms adopted were the ones recommended by the International Committee on Veterinary Gross Anatomical Nomenclature. The brachial plexus received contribution from the spinal cord segments C5; C6; C7; C8 and T1 with the formation of three trunks: cranial (C5 and C6), median (C7) and caudal (C8 and T1) which originated the nerves derived from the plexus, except the antebrachial medial cutaneous nerve that was of a monosegmental origin. The brachial plexus of the lesser anteater presented origin, composition and formation of peripheral nerves similar to the observed in several other domestic and wild mammals.

Scanning electron microscopy of the choroid plexus of the lateral ventricle of the horse.

The present study examined the ultrastructure of the choroid plexus of the lateral ventricle of the horse. The material was fixed in 2.5% glutaraldehyde in 0.1 m sodium phosphate buffer, pH 7.3, processed and analysed by scanning electron microscopy. The choroid plexus was characterized by regions with a predominance of villi, which resembled finger‐like projections or bunches of grapes, and others where straight and uniform folds predominated. Epithelial cells projected into the ventricle and large amounts of cilia and microvilli were observed on their surface. The choroid glomus corresponded to a dilatation of the choroid plexus and was characterized by blood vessels of different calibres surrounded by connective tissue.

Patterns of arterial vascularization in swine hearts

This study aimed to characterize the patterns of arterial vascularization in swine hearts. Ninety swine hearts were submitted to the Spalteholz diaphanization technique in order to dissect the coronary arteries. Three types of arterial vascularization patterns were characterized through the behaviorof the rami circumflexus and interventricularis, namely: balanced, right and left types. The balanced pattern was the most frequently (42.2%); in this case, the rami circumflexus and interventricularis occupied their respective sulci. The right type (40%) was further categorized into three vascularization subtypes. In the first, ramus circumflexus dexter branched from the ramus interventricularis subsinuosus. In the second, the arteria coronaria dextra branched from ramus interventricularis subsinuosus and ramus circumflexus. In the third model, arteria coronaria sinister branched from ramus interventricularis paraconalis. The left type (17.7%) exhibited two subtypes. In the first, ramus interventricularis paraconalis ran through the entire corresponding sulcus and the ventral third of sulcus interventricularis subsinuosus, and ramus interventricularis subsinuosus occupied the dorsal and middle third of its respective sulcus. In the second, ramus interventricularis subsinuosus branched from arteria coronaria dextra and ran through the dorsal and medium thirds of its respective sulcus, and the ventral third was occupied by the collateral branch of ramus circumflexus sinister. Our results reinforce the thesis that the blood distribution system through the coronary artery in swine is similar to human, not only in qualitative but also by a quantitative comparison.

Effects of Pamidronate on Dental Enamel Formation Assessed by Light Microscopy, Energy-Dispersive X-Ray Analysis, Scanning Electron Microscopy, and Microhardness Testing.

The aim of the present work was to investigate birefringence and morphology of the secretory-stage enamel organic extracellular matrix (EOECM), and structural and mechanical properties of mature enamel of upper incisors from adult rats that had been treated with pamidronate disodium (0.5 mg/kg/week for 56 days), using transmitted polarizing and bright-field light microscopies (TPLM and BFLM), energy-dispersive X-ray (EDX) analysis, scanning electron microscopy (SEM) and microhardness testing. BFLM showed no morphological changes of the EOECM in pamidronate and control groups, but TPLM revealed a statistically significant reduction in optical retardation values of birefringence brightness of pamidronate-treated rats when compared with control animals (p0.05). The present study indicates that pamidronate can affect birefringence of the secretory-stage EOECM, which does not seem to be associated with significant changes in morphological and/or mechanical properties of mature enamel.

Topografia vertebromedular de irara (Eira barbara Linnaeus, 1758)

Um cadaver macho, adulto de irara (Eira barbara) foi cedido pelo Centro de Triagem de Animais Silvestres (Cetas), localizado em Salvador/Bahia, ao Setor de Anatomia Veterinaria da Escola de Medicina Veterinaria e Zootecnia da Universidade Federal da Bahia. Trata-se de um mamifero carnivoro que pertence a Familia Mustelidae e Subfamilia Mustelinae que contem o Genero Eira, representado apenas pela Especie Eira barbara. Objetivamos a investigacao da topografia vertebromedular do especime e assim verificar a relacao da medula espinal com o canal vertebral; a identificacao, origem, emergencia e quantificacao dos nervos espinhais relacionados com a medula espinal. Pesquisa numero 43245-1 autorizada pelo Sistema de Autorizacao e Informacao em Biodiversidade (Sisbio-ICMBio/IBAMA). O exemplar foi fixado em solucao de formaldeido a 10% e posteriormente dissecado e radiografado. Foram identificados oito pares de nervos espinhais cervicais, quatorze toracicos e na porcao lombossacral da medula espinhal seis nervos espinais lombares, tres sacrais e mais de tres nervos espinhais caudais. O termino da medula espinal ocorreu no nivel quinta vertebra lombar. Os oito segmentos medulares cervicais localizaram-se entre a primeira e setima vertebras cervicais. Os quatorze nervos espinais toracicos originaram-se na porcao cranial das vertebras respectivas. Os segmentos medulares lombares, sacrais e caudais restringiram-se a regiao lombar da coluna vertebral. O deslocamento cranial dos segmentos medulares foi observado no oitavo cervical, terceiro, quarto e quinto lombares e todos os segmentos sacrais e caudais. As informacoes obtidas poderao ser utilizadas para analises comparativas com as demais especies e com a adocao de medidas que visem proporcionar o bem-estar animal e a preservacao da especie.