Bone reformation and implant integration following maxillary sinus membrane elevation: An experimental study in primates

Background: Recent clinical studies have described maxillary sinus floor augmentation by simply elevating the maxillary sinus membrane without the use of adjunctive grafting materials. Purpose: This experimental study aimed at comparing the histologic outcomes of sinus membrane elevation and simultaneous placement of implants with and without adjunctive autogenous bone grafts. The purpose was also to investigate the role played by the implant surface in osseointegration under such circumstances. Materials and Methods: Four tufted capuchin primates had all upper premolars and the first molar extracted bilaterally. Four months later, the animals underwent maxillary sinus membrane elevation surgery using a replaceable bone window technique. The schneiderian membrane was kept elevated by insertion of two implants (turned and oxidized, Brånemark System®, Nobel Biocare AB, Göteborg, Sweden) in both sinuses. The right sinus was left with no additional treatment, whereas the left sinus was filled with autogenous bone graft. Implant stability was assessed through resonance frequency analysis (Osstell™, Integration Diagnostics AB, Göteborg, Sweden) at installation and at sacrifice. The pattern of bone formation in the experimental sites and related to the different implant surfaces was investigated using fluorochromes. The animals were sacrificed 6 months after the maxillary sinus floor augmentation procedure for histology and histomorphometry (bone-implant contact, bone area in threads, and bone area in rectangle). Results: The results showed no differences between membrane-elevated and grafted sites regarding implant stability, bone-implant contacts, and bone area within and outside implant threads. The oxidized implants exhibited improved integration compared with turned ones as higher values of bone-implant contact and bone area within threads were observed. Conclusions: The amount of augmented bone tissue in the maxillary sinus after sinus membrane elevation with or without adjunctive autogenous bone grafts does not differ after 6 months of healing. New bone is frequently deposited in contact with the schneiderian membrane in coagulum-alone sites, indicating the osteoinductive potential of the membrane. Oxidized implants show a stronger bone tissue response than turned implants in sinus floor augmentation procedures. © 2006 Blackwell Publishing, Inc.

Histological findings following the use of a space-making device for bone reformation and implant integration in the maxillary sinus of primates

Background: Previous studies have shown that membrane elevation results in predictable bone formation in the maxillary sinus provided that implants can be placed as tent poles. In situations with an extremely thin residual crest which impairs implant placement, it is possible that a space-making device can be used under the sinus membrane to promote bone formation prior to placement of implants. Purpose: The present study was conducted to test the hypothesis that the use of a space-making device for elevation of the sinus membrane will result in predictable bone formation at the maxillary sinus floor to allow placement of dental implants. Materials and Methods: Eight tufted capuchin primates underwent bilateral sinus membrane elevation surgery, and a bioresorbable space-making device, about 6 mm wide and 6 mm in height, was placed below the elevated membrane on the sinus floor. An oxidized implant (Nobel Biocare AB, Gothenburg, Sweden) was installed in the residual bone protruding into the created space at one side while the other side was left without an implant. Four animals were sacrificed after 6 months of healing. The remaining four animals received a second implant in the side with a space-making device only and followed for another 3 months before sacrifice. Implant stability was assessed through resonance frequency analysis (RFA) using the Osstell™ (Osstell AB, Gothenburg, Sweden) at installation, 6 months and 9 months after the first surgery. The bone-implant contact (BIC) and bone area inside the threads (BA) were histometrically evaluated in ground sections. Results: Histologically there were only minor or no signs of bone formation in the sites with a space-making device only. Sites with simultaneous implant placement showed bone formation along the implant surface. Sites with delayed implant placement showed minor or no bone formation and/or formation of a dense fibrous tissue along the apical part of the implant surface. In the latter group the apical part of the implant was not covered with the membrane but protruded into the sinus cavity. Conclusions: The use of a space-making device, with the design used in the present study, does not result in bone formation at the sinus floor. However, membrane elevation and simultaneous placement of the device and an implant does result in bone formation at the implant surface while sites with implants placed 6 months after membrane elevation show only small amounts of bone formation. It is suggested that lack of stabilization of the device and/or a too extensive elevation of the membrane may explain the results. © 2009, Wiley Periodicals, Inc.

Demanda heterogénea y segmentación de mercado: el sistema argentino de fondos de pensiones

Incluye Bibliografía

Heterogeneous demand and market segmentation: the Argentine pension funds system

Includes bibliography

Conjunctival flora, Schirmer's tear test, intraocular pressure, and conjunctival cytology in neotropical primates from Salvador, Brazil

Background: This study aimed to establish reference values for selected ophthalmic diagnostic tests in healthy neotropical primates from Salvador, Brazil. Methods: A total of 73 intact adults, including Callithrix jacchus (n = 31), Callithrix penicillata (n = 8), Cebus sp. (n = 22), and Cebus xanthosternos (n = 9) were used to evaluate the normal conjunctival bacterial flora. Cebus xanthosternos (n = 12) were used to evaluate tear production with Schirmer's tear test (STT), intraocular pressure (IOP), and conjunctival cytology. Results: For all animals evaluated, Gram-positive bacteria were predominant. Results of the diagnostic tests in Cebus xanthosternos were as follows: STT: 14.92 ± 5.46 mm/minutes, IOP: 19.62 ± 4.57 mmHg, and conjunctival cytology revealed intermediate squamous epithelial cells in great quantities. Conclusions: These ophthalmic reference values will be particularly useful to diagnose discrete or unusual pathological changes in the neotropical primates eye. © 2013 John Wiley & Sons A/S.

Cambio demográfico y desafíos económicos y sociales en el Uruguay del siglo XXI

Los avances en el proceso de desarrollo del Uruguay en las últimas décadas se manifiestan en diversas dimensiones, entre ellas, la caída de la mortalidad y el descenso de la fecundidad, que reflejan la creciente capacidad de los uruguayos de decidir sobre el tamaño de sus familias. Estos cambios afectan la estructura etaria de la población. El Uruguay atraviesa un proceso de envejecimiento poblacional, que continuará en los próximos años y que motiva las reflexiones contenidas en este libro. Estas tendencias demográficas son una buena noticia ya que el envejecimiento de la población uruguaya es un potente indicador de desarrollo. Pero no podemos desconocer que un cambio de tal magnitud plantea importantes desafíos en diversas dimensiones: en el largo plazo —con el horizonte de 2100— la proporción de la población en edades activas caerá, lo que tendrá diversos impactos sobre el mercado de trabajo y las cuentas públicas. En este libro se exploran los efectos potenciales del cambio demográfico sobre la protección social, las demandas de servicios de salud y educación, el funcionamiento del mercado de trabajo y la dinámica macroeconómica, considerando los cambios institucionales y normativos que serán necesarios para responder a esa nueva realidad.

Caracterização morfológica e molecular de Strongyloides ophidiae (nematoda, strongyloididae) parasitas de serpentes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Molecular phylogeny of the genus Saguinus (Platyrrhini, Primates) based on the ND1 mitochondrial gene and implications for conservation

The systematics of the subfamily Callitrichinae (Platyrrhini, Primates), a group of small monkeys from South America and Panama, remains an area of considerable discussion despite many investigations, there being continuing controversy over subgeneric taxonomic classifications based on morphological characters. The purpose of our research was to help elucidate the phylogenetic relationships within the monkey genus Saguinus (Callitrichinae) using a molecular approach to discover whether or not the two different sections containing hairy-faced and bare-faced species are monophyletic, whether Saguinus midas midas and Saguinus bicolor are more closely related than are S. midas midas and Saguinus midas niger, and if Saguinus fuscicollis melanoleucus and Saguinus fuscicollis weddelli really are different species. We sequenced the 957 bp ND1 mitochondrial gene of 21 Saguinus monkeys (belonging to six species and nine morphotypes) and one Cebus monkey (the outgroup) and constructed phylogenetic trees using maximum parsimony, neighbor joining, and maximum likelihood methods. The phylogenetic trees obtained divided the genus Saguinus into two groups, one containing the small-bodied species S. fuscicollis and the other, the large-bodied species S. mystax, S. leucopus, S. oedipus, S. midas, S. bicolor. The most derived taxa, S. midas and S. bicolor, grouped together, while S. fuscicollis melanoleucus and S. f. weddelli showed divergence values that did not support the division of these morphotypes into subspecies. On the other hand, S. midas individuals showed divergence compatible with the existence of three subspecies, two of them with the same morphotype as the subspecies S. midas niger. The results of our study suggest that there is at least one Saguinus subspecies that has not yet been described and that the conservation status of Saguinus species and subspecies should be carefully revised using modern molecular approaches.

The current status of the new world monkey phylogeny

Four DNA datasets were combined in tandem (6700 bp) and Maximum parsimony and Neighbor-Joining analyses were performed. The results suggest three groups emerging almost at the same time: Atelidae, Pitheciidae and Cebidae. The total analysis strongly supports the monophyly of the Cebidae family, grouping Aotus, Cebus and Saimiri with the small callitrichines. In the callitrichines, the data link Cebuela to Callithrix, place Callimico as a sister group of Callithrix/Cebuella, and show Saguinus to be the earliest offshoot of the callitrichines. In the family Pithecidae, Callicebus is the basal genus. Finally, combined molecular data showed congruent branching in the atelid clade, setting up Alouatta as the basal lineage and Brachyteles-Lagothrix as a sister group and the most derived branch. Two major points remain to be clarified in the platyrrhine phylogeny: (i) what is the exact branching pattern of Aotus, Cebus, Saimiri and the small callitrichines, and (ii), which two of these three lineages, pitheciines, atelines or cebids, are more closely related?

Divergent evolution and purifying selection of the H (FUT1) gene in New World monkeys (Primates, Platyrrhini)

In the present study, the coding region of the H gene was sequenced and analyzed in fourteen genera of New World primates (Alouatta, Aotus, Ateles, Brachyteles, Cacajao, Callicebus, Callithrix, Cebus, Chiropotes, Lagothrix, Leontopithecus, Pithecia, Saguinus, and Saimiri), in order to investigate the evolution of the gene. The analyses revealed that this coding region contains 1,101 nucleotides, with the exception of Brachyteles, the callitrichines (Callithrix, Leontopithecus, and Saguinus) and one species of Callicebus (moloch), in which one codon was deleted. In the primates studied, the high GC content (63%), the nonrandom distribution of codons and the low evolution rate of the gene (0.513 substitutions/site/MA in the order Primates) suggest the action of a purifying type of selective pressure, confirmed by the Z-test. Our analyses did not identify mutations equivalent to those responsible for the H-deficient phenotypes found in humans, nor any other alteration that might explain the lack of expression of the gene in the erythrocytes of Neotropical monkeys. The phylogenetic trees obtained for the H gene and the distance matrix data suggest the occurrence of divergent evolution in the primates.

Comportamento e dieta de Chiropotes albinasus (I. Geoffroy & Deville, 1848) - cuxiú-de-nariz-vermelho

Os cuxiús-de-nariz-vermelho são primatas neotropicais pouco conhecidos e encontramse na Lista de Espécies Ameaçadas da IUCN na categoria “Ameaçada de Extinção”. Este estudo foi desenvolvido com um grupo desta espécie de primatas na RPPN Cristalino, MT. Foi estudado o orçamento de atividades, uso de espaço e a ecologia alimentar do grupo, através do método de “Varredura Instantânea”. O grupo foi acompanhado durante 6 meses, incluindo 2 meses na estação chuvosa e 4 meses na estação seca. As categorias comportamentais Deslocamento, Alimentação e Parado foram responsáveis por 81,17% dos registros gerais de atividades. Os animais utilizaram com maior intensidade o estrato intermediário da floresta (entre 16 e 20 metros). A dieta do grupo foi preferencialmente frugívora (82,52%), mas também se alimentaram de invertebrados. Cerca de 18 famílias botânicas foram consumidas. Sendo os taxons Arrabidaea sp. e Brosimum latescens os mais comuns. Nos meses de seca houve um maior acréscimo de outros itens alimentares, como flores e invertebrados na dieta dos cuxiús. O tamanho do grupo variou entre 1 e 19 indivíduos ao longo do estudo, assim como a estrutura sexual que também variou bastante. Foi observado o cuidado parental por parte dos machos, além de interações agonísticas interespecíficas entre Ateles marginatus e Sapajus apella.

Efeitos do tipo de floresta e da estrutura de habitat em assembléias de primatas no sudoeste da Amazônia

A heterogeneidade ambiental expressa diferenças naturais entre áreas e é um fator determinante para a riqueza e abundância local de primatas. Neste estudo nós investigamos a composição e estrutura de assembléias de primatas em quatro tipos de floresta: floresta de terra firme, florestas de igapó sazonalmente inundáveis por rios de águas claras (aberta e densa) e cerradão na Reserva Biológica do Guaporé, sudoeste da Amazônia Brasileira. Além disso, avaliamos a associação entre a ocorrência e abundância dos primatas com diferenças estruturais das florestas. Realizamos 617,8 km de censos pelo método de transecção linear (~154 km por tipo de floresta) e avaliamos a estrutura da vegetação em 108 parcelas de 200 m² (0,54 ha por tipo de floresta). Dez espécies de primatas foram registradas durante os 11 meses deste estudo. A floresta de terra firme apresentou o maior número de espécies e a maior densidade de primatas, principalmente devido à presença exclusiva de Callicebus moloch e a maior abundância de Sapajus apella. A elevada densidade de Ateles chamek na floresta aberta inundável foi preponderante para a maior biomassa de primatas neste tipo de floresta. Nas florestas inundáveis e na terra firme, Ateles chamek e Sapajus apella responderam juntas por mais de 70% da biomassa de primatas, e no cerradão apenas Sapajus apella foi responsável por 68% da biomassa. Diferenças entre tipos de floresta na composição específica e abundância relativa de primatas foram associadas com o regime de inundação e com algumas variáveis de estrutura de habitat (densidade de árvores no sub-bosque e no dossel, abertura do dossel, altura total do dossel e densidade de palmeiras e lianas). Nossos resultados reforçam a importância de paisagens heterogêneas na Amazônia, pois estas áreas tendem a contribuir para uma maior diversidade de espécies em uma escala de paisagem.

Caracterização e dinâmica espacial da caça de primatas em comunidades ribeirinhas da Amazônia Central

Os primatas são importante item alimentar para as populações que vivem em locais isolados, e estão entre as espécies mais caçadas por populações tradicionais e indígenas, principalmente nas regiões neotropicais. No entanto, pouco se conhece sobre as características e os padrões espaciais da atividade de caça, e sua abrangência no espaço e no tempo, impedindo uma real avaliação do impacto desta atividade. O objetivo deste trabalho foi descrever, quantificar e analisar a dinâmica espacial da caça de primatas na Amazônia Central, em ambientes de várzea e de terra firme, através de dados de monitoramento de pequenas comunidades ribeirinhas acumulados ao longo de 11 anos. Neste período, o sistema de monitoramento registrou 402 caçadas de primatas, totalizando 541 animais abatidos de nove espécies: Alouatta juara, Aotus cf. vociferans, Ateles chamek, Cacajao ouakary, Callicebus torquatus, Cebus albifrons, Saguinus inustus, Saimiri cassiquiarensis e Sapajus macrocephalus. Destas caçadas, 240 ocorreram em Amanã e 162 em Mamirauá. As distâncias percorridas pelos caçadores a partir das suas comunidades foram significativamente diferentes nos dois ambientes (T= -2,451; gl = 41; p <0,05), os caçadores de terra firme caçam em locais mais distantes que os caçadores de várzea. Quando analisamos o tamanho das áreas utilizadas pelos caçadores, as de terra firme também foram significativamente maiores do que a várzea (F(2,56)=21,471; P<0,01). Embora a contribuição da biomassa de primatas seja pequena, quando comparada a outras espécies, como queixada e paca, o guariba ainda é uma das espécies mais caçadas na Amazônica Central. Para conhecermos o real impacto da atividade de caça entre os primatas, o estudo comprova a necessidade de um monitoramento contínuo das áreas de caça, bem como a análise da sua variação espacial ao longo dos anos.

Goniometric evaluation of both forelimbs and hind limbs in two species of Neotropical monkeys

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)