Identification and characterization of a rich population of CD34+ mesenchymal stem/stromal cells in human parotid, sublingual and submandibular glands.

Mesenchymal stem/stromal cells (MSCs) play crucial roles in maintaining tissue homeostasis during physiological turnovers and injuries. Very little is known about the phenotype, distribution and molecular nature of MSCs in freshly isolated human salivary glands (SGs) as most reports have focused on the analysis of cultured MSCs. Our results demonstrate that the cell adhesion molecule CD34 was widely expressed by the MSCs of human major SGs, namely parotid (PAG), sublingual (SLG) and submandibular (SMG) glands. Further, gene expression analysis of CD34+ cells derived from fetal SMGs showed significant upregulation of genes involved in cellular adhesion, proliferation, branching, extracellular matrix remodeling and organ development. Moreover, CD34+ SMG cells exhibited elevated expression of genes encoding extracellular matrix, basement membrane proteins, and members of ERK, FGF and PDGF signaling pathways, which play key roles in glandular development, branching and homeostasis. In vitro CD34+ cell derived SG-MSCs revealed multilineage differentiation potential. Intraglandular transplantation of cultured MSCs in immunodeficient mice led to their engraftment in the injected and uninjected contralateral and ipsilateral glands. Engrafted cells could be localized to the stroma surrounding acini and ducts. In summary, our data show that CD34+ derived SG-MSCs could be a promising cell source for adoptive cell-based SG therapies, and bioengineering of artificial SGs.

Fratura mandibular durante remoção do terceiro molar: fatores de risco, medidas preventivas e métodos de tratamento / Mandibular fracture during third molar removal: risk factors, preventive measures and treatment methods

Fraturas mandibulares durante à extração do terceiro molar é uma complicação incomum, com consequências graves. Ocorrem quando a força de resistência do tecido ósseo e menor que as forças aplicadas durante o procedimento. O objetivo deste trabalho consiste em apresentar um caso clínico de fratura mandibular durante a exodontia do terceiro molar e também discutir os riscos, medidas preventivas e métodos de tratamento.

Mandibular fracture during third molar removal is an uncommon complication, with serious consequences. This occurs when the forces applied during surgery exceeds the strength of bone. The objective of this work is present a clinical case of mandibular fracture during third molar removal and also, discuss the risks, preventive measures and treatment methods.

Fratura mandibular após ferimento por arma branca: diagnóstico e conduta clínica / Mandibular fracture after stab wounds: diagnosis and clinical conduct

INTRODUÇÃO - Os ferimentos em face por armas brancas são raros, mas quando ocorrem, o cirurgião Buco-Maxilo-Facial deve estar apto a tratar esse tipo de lesão, haja vista que os insucessos podem resultar em alterações estético-funcionais que podem ser prejudiciais tanto funcional como psicologicamente. OBJETIVO - O artigo em questão buscou relatar um caso clinico de um paciente vitima de agressão física com extensa laceração em face por arma branca. CONCLUSÃO - O conhecimento dos princípios básicos de tratamento de lesões nos tecidos moles da face por arma branca é de suma importância para o alcance a resultados estéticos e funcionais satisfatórios.

INTRODUCTION - Facial stab wounds are rare but when occurs, the Maxillo-Facial surgeon should be able to treat this injury, given that failures can result in aesthetic and functional changes that can be functionally and psychologically harmful. OBJECTIVE - The article in question report a clinical case of a patient victim of assault with extensive facial laceration by a knife. CONCLUSION - Treatments knowledge about soft tissue injuries by facial stab wounds has a great importance to achievinga satisfactory aesthetic and functional result.

Ultrastructure of motor nerve terminals in the anterior third of Wistar rat tongue.

The nerve terminals of intrinsic muscular fibers of the tongue of adult wistar rats was studied by using silver impregnation techniques, transmission electron microscopy (TEM), and high resolution scanning electron microscopy (HRSEM) to observe the nerve fibers and their terminals. Silver impregnation was done according to Winkelman and Schmit, 1957. For TEM, small blocks were fixed in modified Karnovsky solution, postfixed in 1% buffered osmium tetroxide solution, and embedded in Spurr resin. For HRSEM, the parts were fixed in 2% osmium tetroxide solution with 1/15 M sodium phosphate buffer (pH 7.4) at 4 degrees C for 2 h, according to the technique described by Tanaka, 1989. Thick myelinated nerve bundles were histologically observed among the muscular fibers. The intrafusal nerve fiber presented a tortuous pathway with punctiform terminal axons in clusters contacting the surface of sarcolemma. Several myelinated nerve fibers involved by collagen fibers of the endoneurium were observed in HRSEM in three-dimensional aspects. The concentric lamellae of the myelin sheath and the axoplasm containing neurofilaments interspersed among the mitochondria were also noted. In TEM, myofibrils, mitochondria, rough endoplasmic reticulum, Golgi's apparatus, and glycogen granules were observed in sarcoplasm. It is also noted that the sarcomeres constituted by myofilaments with their A, I, and H bands and the electron dense Z lines. In areas adjacent to muscular fibers, there were myelinated and unmyelinated nerve fibers involved by endoneurium and perineurium. In the region of the neuromuscular junction, the contact with the sarcolemma of the muscular cell occurs forming several terminal buttons and showing numerous evaginations of the cell membrane. In the terminal button, mitochondria and numerous synaptic vesicles were observed.

Structure and microstructure of coronary dentin in non-erupted human deciduous incisor teeth.

The dentin structure of non-erupted human deciduous mandibular and maxillary central and lateral incisor teeth was studied employing light and scanning electron microscopy. For light microscopy, nitric-acid-demineralized and ground sections were used. The sections were stained by hematoxylin-eosin, picrosirius and azo-carmine methods, and ground specimens were prepared using a carborundum disk mounted in a handpiece. For SEM study, teeth were frozen in liquid nitrogen and fractured at longitudinal and transversal directions. Structurally, demineralization and ground methods revealed tubules with primary and secondary curvatures, canaliculi, giant tubules, interglobular dentin, predentin, and intertubular dentin. Scanning electron microscopy showed three-dimensional aspects of dentinal tubules, canaliculi, peritubular dentin, intertubular dentin, and predentin. This study contributes to knowledge about dentin morphology showing characteristics of teeth not yet submitted to mastication stress.

Structure and microstructure of coronary dentin in non-erupted human deciduous incisor teeth

The dentin structure of non-erupted human deciduous mandibular and maxillary central and lateral incisor teeth was studied employing light and scanning electron microscopy. For light microscopy, nitric-acid-demineralized and ground sections were used. The sections were stained by hematoxylin-eosin, picrosirius and azo-carmim methods, and ground specimens were prepared using a carborundum disk mounted in a handpiece. For SEM study, teeth were frozen in liquid nitrogen and fractured at longitudinal and transversal directions. Structurally, demineralization and ground methods revealed tubules with primary and secondary curvatures, canaliculi, giant tubules, interglobular dentin, predentin, and intertubular dentin. Scanning electron microscopy showed three-dimensional aspects of dentinal tubules, canaliculi, peritubular dentin, intertubular dentin, and predentin. This study contributes to knowledge about dentin morphology showing characteristics of teeth not yet submitted to mastication stress