• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • Tagged with
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Post mortem microstructural change to the skeleton

Bell, Lynne Sevon January 1995 (has links)
The microstructural impact of diagenetic or post mortem alteration has been assessed in predominately human skeletal tissues. The method of assessment selected was microscopical analysis, mainly using backscattered electron imaging in a scanning electron microscope and, to a lesser extent, confocal reflection microscopy. The microstructural morphologies of post mortem alteration were investigated in archaeological material, both normal and pathological, from terrestrial and marine contexts. Further studies were undertaken on a case-by-case basis on skeletal material which offered some unique pathology, environmental context, spatial relationship, time variable, or mortuary practice. Additionally, the effect of diagenetic change on mitochondrial DNA (mtDNA) recovery and the potential location of DNA within the skeletal tissues were investigated. Two quantitative studies were undertaken to validate and measure the observed mineral density changes. The investigations showed that post mortem alteration or diagenetic change to skeletal material can be extensive, and can occur shortly after death. Diagenesis did not represent a post burial phenomenon as the term diagenesis suggests, but was found to have begun above ground in a range of exposural contexts. The implication of gut bacteria in the promotion of early bacterially-related microstructural change was strong, and it is proposed that body status at the point of, or soon after, death is important. Post mortem alteration to skeletal microstucture can provide environmental information, since terrestrial and marine contexts exhibited distinct morphologies. It may also provide localized environmental information within a stratigraphic matrix. Characterizing the post mortem microstructural and density changes to bone has helped to elucidate the preservational status of mtDNA in terms of its relative retrieval in archaeological specimens, and the potential location of mtDNA in bone. It is proposed that the shift in mineral density that was found in bacterially-remodelled specimens from terrestrial contexts, relative to the excellent preservation of marine specimens, may help to explain why marine vertebrates far outnumber terrestrial ones in the fossil record, since bacterially driven microstructural change is here considered to be a destructive form of fossilisation.
2

Efeito do canabidiol no processo cicatricial de defeitos ?sseos cr?ticos mecanicamente induzidos em calota craniana de ratos : avalia??o cl?nica e histol?gica

Noronha, Rafael de Ara?jo 28 March 2018 (has links)
Submitted by PPG Odontologia (odontologia-pg@pucrs.br) on 2018-06-27T16:07:31Z No. of bitstreams: 1 RAFAEL_DE_ARAUJO_NORONHA_DIS.pdf: 673617 bytes, checksum: 0e6162f0003c8204cabce0b4b4b0a140 (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-07-04T14:34:33Z (GMT) No. of bitstreams: 1 RAFAEL_DE_ARAUJO_NORONHA_DIS.pdf: 673617 bytes, checksum: 0e6162f0003c8204cabce0b4b4b0a140 (MD5) / Made available in DSpace on 2018-07-04T14:52:03Z (GMT). No. of bitstreams: 1 RAFAEL_DE_ARAUJO_NORONHA_DIS.pdf: 673617 bytes, checksum: 0e6162f0003c8204cabce0b4b4b0a140 (MD5) Previous issue date: 2018-03-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Maxillofacial fractures of traumatic origin have a high incidence in the world population. These can be treated in different ways, ranging from conservative methods to widely invasive procedures. Among the multiple possibilities of treatment of this type of disease is the use of herbal medicines, where cannabidiol (CBD) is inserted. This is the main non-psychomimetic component of Cannabis sativa (Can-ns) and plays potent anti-inflammatory, antioxidant and analgesic effects in a variety of pathological conditions. The present dissertation is structured in the form of 2 scientific papers. The first one consists of a literature review, whose objective was to evaluate the mechanisms of action of CBD that may be involved in bone repair. The results of this study suggest that CBD is unable substance of interfering in the healing process of bone defects from its anti-inflammatory and antioxidant potential. The second is an experiment in an animal model, using 64 Wistar rats, divided into two groups (test with CBD and control). At the periods of two, four, six and eight weeks, they were evaluated clinically and histologically in the cicatricial process of mechanically induced bone defects in the skull cap of rats. It was found that the CBD exerted a beneficial effect in the fourth week after treatment where an increase in the mean of neoformed bone within the defect was observed, however, no statistically significant difference was observed in the healing process of the bone defects at the times analyzed. These results suggest the need to deepen the theme, aiming at a better understanding of the possible effects of CBD on bone metabolism and repair. / As fraturas ?sseas bucofaciais de origem traum?tica possuem uma elevada incid?ncia na popula??o mundial. Estas podem ser tratadas de distintas formas, que variam desde m?todos conservadores at? procedimentos amplamente invasivos. Dentre as m?ltiplas possibilidades de tratamento deste tipo de enfermidade, est? a utiliza??o de fitoter?picos, onde insere-se o canabidiol (CBD). Esse ? o principal componente n?o-psicomim?tico da Cannabis sativa (Can-ns) e desempenha potentes efeitos anti-inflamat?rios, antioxidantes e analg?sicos em diversas condi??es patol?gicas. A presente disserta??o est? estruturada na forma de 2 artigos cient?ficos. No primeiro foi realizada uma revis?o de literatura, cujo objetivo foi avaliar os mecanismos de a??o do CBD que possam estar envolvidos no reparo ?sseo. Os resultados deste estudo sugerem que o CBD ? uma subst?ncia capaz de interferir no processo cicatricial de defeitos ?sseos a partir do seu potencial antiinflamat?rio. O segundo trata de um experimento desenvolvido em modelo animal, utilizando 64 ratos Wistar, divididos randomicamente em 2 grupos (teste com CBD e controle). Avaliou-se cl?nica e histologicamente o efeito da administra??o intraperitoneal do CBD, na dose de 10 mg/kg/dia, por duas, 4, 6 e 8 semanas, no processo cicatricial de defeitos ?sseos mecanicamente induzidos em calota craniana de ratos. Constatou-se que o CDB exerceu um efeito ben?fico na quarta semana p?s tratamento onde observou-se um aumento na m?dia de osso neoformado no interior do defeito. Contudo n?o foi observada diferen?a estatisticamente significativa no processo cicatricial dos defeitos ?sseos nos tempos analisados. Estes resultados sugerem a necessidade de aprofundar o tema, visando uma melhor compreens?o sobre poss?veis efeitos do uso do CBD no metabolismo e reparo ?sseo.
3

NEOPLASMAS ÓSSEOS E OSTEOPATIA HIPERTRÓFICA EM CÃES / BONE NEOPLASMS AND HYPERTROPHIC OSTEOPATHY IN DOGS

Trost, Maria Elisa 19 February 2013 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / This doctoral thesis involved the study of three groups of neoplasms that affect bones of dogs (primary bone neoplasms, bone metastases, and multicentric neoplasms with bone involvement) and a bone lesion, often paraneoplastic, known as hypertrophic osteopathy. The study of primary bone neoplasms covered important pathological and epidemiological aspects for the diagnosis of this group of tumors, with emphasis on osteosarcomas. It was retrospectively performed, covering a period of 22 years. Reports of biopsy and necropsy cases of dogs received at the Laboratório de Patologia Veterinária, Universidade Federal de Santa Maria (LPVUFSM) were analyzed. Out of the 90 primary bone neoplasms diagnosed in this period, 89 were malignant. Osteosarcoma was the most prevalent (86.7%) neoplasm. Regarding osteosarcomas, most cases occurred in large and giant breed dogs, between six and 10 years of age. The neoplasms predominantly involved the appendicular skeleton and were 3.5 times more prevalent in the forelimbs than in the hindlimbs. The predominant histologic subtype was the osteoblastic. For the study of neoplasms that comprise the second and third groups, i.e., neoplasms with bone metastases or with bone involvement by multicentric neoplasms, a prospective study was conducted over a period of three years. The skeleton of 110 dogs, with 118 malignant neoplasms of different origins received in the necropsy service of the LPV-UFSM were examined for bone lesions. Twenty-one cases of bone metastases or bone involvement by multicentric neoplasms (19.1%) were detected. In general, the bone lesions affected more female dogs. However, when mammary gland neoplasms were not considered, the distribution of cases according to the sex was very similar. The mean age was 9-years-old and dogs of different breeds were affected. The mammary gland was the primary site of most bone metastases, followed by neoplasms of the musculoskeletal and respiratory systems. Most metastases were observed grossly and occurred in multiple bones. However, in 23% of the cases metastases could only be observed microscopically. Vertebrae and humerus were the mosdt frequently affected bones. Simultaneously, seven cases of hypertrophic osteopathy, diagnosed in a period of 11 years at the LPV-UFSM, were retrospectively and prospectively studied. Affected dogs had clinical signs of bone involvement and lesions mainly in the long bones of the limbs. The lesions consisted of periosteal bone neoformation, detected on radiographs, bone inspection during necropsy, and with great level of detail, in macerated bone specimens. The bone proliferation was partially circumferential and occurred mainly in the diaphysis of long bones. It consisted of bone trabeculae of irregular size and thickness, which were arranged perpendicularly to the original cortical bone. In all cases, the lesions of hypertrophic osteopathy were associated with lung neoplasms (primary or metastatic). In two of the seven cases, the lung metastases were of primary bone sarcomas and, in one case, there was a primary lung osteosarcoma (extra-skeletic). / Esta tese envolveu o estudo de três grupos de neoplasmas que afetam os ossos de cães (neoplasmas ósseos primários, metástases ósseas e neoplasmas multicêntricos com envolvimento ósseo) e uma alteração óssea, muitas vezes paraneoplásica, conhecida como osteopatia hipertrófica. O estudo dos neoplasmas ósseos primários envolveu aspectos epidemiológicos e patológicos importantes para o diagnóstico deste grupo de tumores, com ênfase nos osteossarcomas. Foi realizado de forma retrospectiva, compreendo um período de 22 anos. Foram analisados laudos de casos de biópsias e necropsias de cães recebidos no Laboratório de Patologia Veterinária da Universidade Federal de Santa Maria (LPV-UFSM). Dos 90 neoplasmas ósseos primários diagnosticados neste período, 89 eram malignos, sendo os osteossarcomas os mais prevalentes (86,7%). Em relação aos osteossarcomas, a maioria dos casos ocorreu em cães de raças grandes e gigantes e entre seis e 10 anos de idade. Os neoplasmas envolvendo o esqueleto apendicular predominaram e foram 3,5 vezes mais prevalentes nos membros anteriores que nos posteriores. O subtipo histológico predominante foi o osteoblástico. Para o estudo dos neoplasmas que compreenderam o segundo e o terceiro grupos, ou seja, neoplasmas com metástases ósseas ou o envolvimento ósseo em neoplasmas multicêntricos, foi realizado um estudo prospectivo durante um período de três anos. Neste período, cães provenientes do serviço de necropsias do LPV-UFSM foram avaliados. O esqueleto de 110 cães portadores de 118 neoplasmas malignos de diferentes origens foi examinado em busca de lesões ósseas. Foram encontrados vinte e um casos de metástases ou neoplasmas multicêntricos com envolvimento ósseo (19,1%). Em geral, as lesões ósseas afetaram mais as fêmeas. No entanto, quando os neoplasmas originados na glândula mamária foram desconsiderados, a distribuição dos casos de acordo com o sexo foi muito semelhante. Foram afetados cães com idade média de 9 anos e de diferentes raças. A glândula mamária foi a origem da maioria dos tumores que metastatizaram para os ossos, seguida do sistema músculo-esquelético e respiratório. A maioria das metástases foi detectada macroscopicamente e ocorreu em múltiplos ossos. Entretanto, em 23% dos casos as metástases só puderam ser observadas microscopicamente. Dentre os ossos afetados, vértebras e úmero foram os mais frequentemente acometidos. Paralelamente foram estudados, de forma retrospectiva, sete casos de osteopatia hipertrófica diagnosticados em um período de 11 anos no LPV-UFSM. Os cães afetados apresentavam sinais clínicos indicativos de envolvimento ósseo e lesões macroscópicas principalmente nos ossos longos dos membros. As lesões consistiram de neo-formação óssea periosteal, detectada em exame radiográfico, na inspeção óssea durante a necropsia e, com grande nível de detalhamento, em espécimes ósseos macerados. A proliferação óssea observada era parcialmente circunferencial e ocorreu principalmente na diáfise dos ossos longos. Era constituída por trabéculas ósseas de tamanho e espessura irregulares que estavam dispostas de forma perpendicular ao córtex ósseo original. Em todos os casos, as lesões de osteopatia hipertrófica foram associadas a neoplasmas pulmonares (primários ou metastáticos). Em dois dos sete casos, as metástases pulmonares eram de sarcomas ósseos e, em um caso, havia um osteossarcoma primário pulmonar (extraesquelético).

Page generated in 0.0646 seconds