Objectives: Sarcopenia is defined using a variety of different muscle variables, muscle mass adjustment techniques and cut offs for each variable. The objectives of this thesis were to assess how operational differences in sarcopenia definitions impact the agreement between definitions and the association between sarcopenia and health outcomes such as falls. Methods: A list of sarcopenia definitions was developed which captured the combinations of muscle variables, muscle mass adjustment techniques, and cut offs used in the literature based on a systematic review conducted for this thesis. These definitions were applied to participants taking part in the Canadian Longitudinal Study on Aging, a national study of participants aged 45 to 85 years at baseline. The agreement between the definitions and the association of each definition with falls was assessed. Findings: Both the combination of muscle variables as well as the different muscle mass adjustment techniques generally had limited agreement. Sarcopenia definitions including muscle mass and muscle strength were associated with falls in males, but none of the sarcopenia definitions were associated with falls in females. Area under the curve analyses revealed that even sarcopenia definitions associated with more than two times the odds of falling in males, had a small impact on identifying fallers with values ≤0.56. Conclusions: The results of this thesis show that the existing range of definitions used to define sarcopenia are not equivalent based on the limited agreement and inconsistent association of sarcopenia with falls. The results also show that sarcopenia may have limitations as clinically useful diagnosis for identifying fallers with area under the curve values for all definitions showing that the identification of fallers based on sarcopenic status was at best, modestly better than chance alone. / Thesis / Doctor of Philosophy (PhD) / Definitions for sarcopenia differ in terms of which muscle variables are included, how muscle mass is adjusted, and which cut offs to use for each variables. This thesis assessed the impact of different methods of operationalizing sarcopenia on the proportion of sarcopenic participants, agreement between definitions, and the strength of the association between sarcopenia and falls. The variables used to operationalize sarcopenia as well as different techniques for adjusting muscle mass resulted in poor agreement between definitions. In males, these factors impacted which definitions were significantly associated with falls, and in females, sarcopenia was not associated with falls for any definition. For all definitions, sarcopenia status poorly discriminated between those that would or would not fall. Together, these results show that different sarcopenia definitions are not equivalent and that a standard definition is required. However, this thesis also shows that more work is required to determine the clinical utility of sarcopenia.

The non-pathogenic porcine circovirus type 1 (PCV1) was originally isolated as a persistent contaminant of the porcine kidney cell line PK-15. Whereas, porcine circovirus type 2 (PCV2) causes postweaning multisystemic wasting syndrome (PMWS) in pigs, which is devastating to the swine industry. My objectives were to determine the effect of maternally derived antibodies on PCV2 infection, assess the role of 2 amino acid substitutions in the PCV2 capsid protein in PCV2 attenuation, evaluate the effect of Rep gene exchange between PCV1 and PCV2 on growth characteristics of a chimeric PCV2, and evaluate the role of open reading frame (ORF) 3 of PCV2 in virus replication and pathogenesis in pigs. Under field conditions, PCV2 infection is widespread and most breeding pigs are seropositive. Assessment of the role of PCV2 maternal antibodies in preventing PCV2 infection in piglets provided evidence that higher levels of maternal antibody provide more protection to piglets. Two amino acid substitutions in the PCV2 capsid protein that enhanced virus replication in vitro and attenuated the virus in vivo were evaluated for their pathogenicity in pigs. The results indicated that P110A and R191S are collectively responsible for virus attenuation. PCV1 replicates better in PK-15 cells and grows at least 1-log titer higher than PCV2. A chimeric PCV with the rep gene of PCV1 replacing that of PCV2 in the genomic backbone of PCV2 replicated more rapidly than PCV1 and PCV2, and more efficiently than PCV2, although to a titer similar to PCV1. The ORF3 of PCV2 is believed to encode a protein involved in apoptosis. The ORF3 start codon was mutated from ATG to GTG and the resulting mutant muPCV2 was infectious in vitro and in pigs; therefore ORF3 is dispensable for virus replication. The pathogenicity of muPCV2 was compared with PCV2 in vivo. Delayed viremia and seroconversion, decreased viral loads, lower level of IgG antibodies, and lower amounts of PCV2 antigen in mesenteric lymph nodes suggested attenuation of muPCV2. However, there was no significant difference in histological or gross lesions in tissues between PCV2- and muPCV2-inoculated groups. The role of ORF3 in attenuation needs to be further elucidated. / Ph. D.

Private lands play a crucial role in protecting at-risk species in the Southeast, and finding ways to increase landowner participation in conservation efforts is essential. I surveyed non-industrial private forest owners in Mississippi to assess how their motivations for land management relates to their willingness to manage for at-risk species. I also assessed if landowners who hunt are more willing to manage for at-risk species. Results showed that landowners are motivated by a sense of stewardship for the land, but there is a lack of awareness about at-risk species. Although the effect size was minimal, there is a significant relationship between landowners who hunt and a willingness to manage for at-risk species. I also surveyed Mississippi landowners about chronic wasting disease (CWD) in white-tailed deer. Overall, there was moderate concern about CWD, but it had a minimal effect on landowners’ motivation for managing their land.

A síndrome de emagrecimento progressivo (SEP) dos calitriquídeos representa importante causa de morbidade e mortalidade de sagüis mantidas em cativeiro. A etiologia dessa síndrome não está estabelecida e suas principais características são emagrecimento progressivo, diarréia, colite, anemia, paralisia dos membros posteriores e alopecia. Com esse estudo pretende-se responder se a síndrome é um processo de má-absorção ou de desnutrição protéico-calórica primária, caracterizar o quadro histológico intestinal de base e a resposta imunológica tecidual local. Foram estudados três grupos de sagüis: 1) 40 doentes com SEP pertencentes ao criadouro Mucky, 2) 9 controles vivos sadios, 3) 8 necrópsias de controles sem SEP. Foi realizado acompanhamento clínico, exame laboratorial das fezes, teste de absorção de D-xilose, avaliação da composição nutricional e digestibilidade da dieta, estudo anatomopatológico, incluindo avaliação semiquantitativa e análise morfométrica do jejuno de sagüis que foram a óbito naturalmente por SEP e dos controles. Os resultados alcançados permitiram caracterizar o perfil dos animais acometidos no nosso meio; os sinais clínicos maiores e menores da síndrome; identificar esteatorréia; o comprometimento da função digestiva e absortiva do intestino delgado dos sagüis com SEP; caracterizar o quadro histopatológico como uma enterite com atrofia semelhante à doença celíaca humana. A associação dos resultados clínicos, laboratoriais e histológicos permitiu definir a SEP como processo de má-absorção, por perda de superfície absortiva de intestino delgado, decorrente de enterite crônica imunomediada, de padrão celíaco-like que leva a progressiva e grave desnutrição secundária dos animais acometidos. / Wasting marmoset syndrome (WMS) is an important cause of morbidity and mortality of marmosets and tamarins kept in captivity. The etiology of this syndrome has not been established and its main features are progressive weight loss, diarrhea, colitis, anemia, hind limb paralysis, and alopecia. The aims of this research were to demonstrate that WMS is a malabsorption process, and to analyze the underlying histological lesion of the intestine and to characterize the local immune response of the small intestine. The sick marmosets (n=40) were compared to live normal controls (n=9) or to necropsied marmosets that died of other diseases than WMS (n=8), regarding clinical follow up, fecal analysis, D-xylose absorption test, evaluation of the nutritional composition and digestibility of the diet, gross and histological examination and morphometric approach of the jejune of wasters and control marmosets. These data revealed general features of WMS under our general captivity conditions, major and minor clinical signs of waster marmosets, impaired absorptive and digestive function of small intestine with steatorrhea and atrophic enteritis similar to celiac disease. The clinical and laboratory data associated with pathology examination demonstrated that WMS is a malabsorption process due to loss of absorptive surface area that results in progressive secondary malnutrition of the waster marmosets. The major immunologic mechanism underlying the celiac-like enteritis of WMS is a T-cell immune mediated response that affects intestine architecture

Made available in DSpace on 2014-07-29T15:23:44Z (GMT). No. of bitstreams: 1 Dissertacao Marta I V Andrade.pdf: 1042992 bytes, checksum: 4667b810c3cd428f39ff87e1357a4645 (MD5) Previous issue date: 2012-03-02 / BACKGROUND: Protein energy wasting commonly occur in patients with chronic kidney disease. Changes in muscle function arise even before changes in anthropometric and biochemical parameters.Thus, a method for evaluating muscle function and strength becomes essential for these patients. OBJECTIVES: To evaluate the handgrip strength (HGS) and its association with nutritional status of patients with chronic kidney disease on hemodialysis. METHODS: A cross-sectional study conducted between May and July/2011. The sample included 90 patients, 48.8% male and 51.2% female. The HGS was performed three times with a hydraulic hand dynamometer (Takei) in the arm without fistula. For each patient were considered the best strength measure. Values lower than percentile 10 were considered as low HGS. The nutritional status diagnosis was given by Subjective Global Assessment (SGA). RESULTS: The average age was 52 ± 14.7 years. The hypertensive nephrosclerosis was the most frequent cause of chronic kidney disease (31.1%). The average HGS was among 32.0 ± 8.7kgf in men and 20.7 ± 6.1kgf in women (p<0.001). 11.3% of men and 21.7% of woman were classified as moderatey malnourished by SGA, 31.8% and 34.8% of men and women, respectively, were classified with low muscle function. Low HGS was associated with time on hemodialysis for men and showed good sensitivity (73.3%) and specificity (74.7%) for malnutrition diagnosis. In multiple logistic regression analysis, low-power handgrip strength prevalence was two times higher (PR =2.00, 95% CI: 1.19 to 3.34) for patients classified as moderate malnourished by SGA. CONCLUSION: This study showed high prevalence of low muscle function and good association between HGS and SGA in patients with chronic kidney disease on hemodialysis classified by dynamometry. It is suggested that HGS, an inexpensive and noninvasive measurement, can be used in clinical practice as a screening tool of nutritional status. It is sensitive for malnutrition diagnosis. / INTRODUÇÃO: A desnutrição energética proteica é frequente nos pacientes com doença renal crônica. As alterações da função do músculo surgem antes das modificações dos parâmetros antropométricos e bioquímicos. Assim, torna-se importante um método para avaliar a função e força muscular. OBJETIVOS: Avaliar a força de aperto de mão e sua associação com estado nutricional de pacientes com doença renal crônica em hemodiálise. MÉTODOS: Estudo transversal, realizado em maio a julho de 2011. Foram incluídos no total 90 pacientes. A Força de Aperto de Mão (FAM) foi realizada três vezes com dinamômetro hidráulico no braço sem a fístula. Considerou o melhor desempenho da medida da FAM. Os valores menores que o percentil 10 foram considerados como baixa FAM, de acordo com ponto de corte proposto para população para população de Niterói, Rio de Janeiro, Brasil. O diagnóstico do estado nutricional foi realizado por meio da Avaliação Subjetiva Global (ASG). RESULTADOS: Do total da amostra 48,8% eram do sexo masculino e 51,2% do sexo feminino. A média de idade foi 52±14,7 anos. A nefroesclerose hipertensiva foi a causa mais frequente de doença renal crônica (31,1%). A FAM média entre os homens foi de 32,0 ± 8,7kgf e entre as mulheres 20,7 ± 6,1kgf (p=<0,001). Pela classificação da ASG, 11,3% dos homens e 21,7% das mulheres foram classificados como desnutridos moderados; 31,8% e 34,8% dos homens e mulheres, respectivamente, foram classificados com baixa força de aperto de mão. Os homens com maior tempo em hemodiálise apresentaram baixa FAM. A sensibilidade (73,3%) e especificidade (74,7%) da FAM para o diagnóstico de desnutrição foi adequada. Na regressão logística múltipla a prevalência de baixa força de aperto de mão foi duas vezes maior (RP=2,00; IC95%: 1,19-3,34) para os pacientes classificados com desnutrição moderada pela ASG. CONCLUSÃO: Este estudo mostrou alta frequência de baixa FAM e associação da FAM com a ASG em pacientes com doença renal crônica em hemodiálise. Sugere-se que a FAM, uma medida barata e não invasiva, possa ser usada na prática clínica como ferramenta de triagem do estado nutricional, pois apresenta boa capacidade de predizer a desnutrição.

A síndrome de emagrecimento progressivo (SEP) dos calitriquídeos representa importante causa de morbidade e mortalidade de sagüis mantidas em cativeiro. A etiologia dessa síndrome não está estabelecida e suas principais características são emagrecimento progressivo, diarréia, colite, anemia, paralisia dos membros posteriores e alopecia. Com esse estudo pretende-se responder se a síndrome é um processo de má-absorção ou de desnutrição protéico-calórica primária, caracterizar o quadro histológico intestinal de base e a resposta imunológica tecidual local. Foram estudados três grupos de sagüis: 1) 40 doentes com SEP pertencentes ao criadouro Mucky, 2) 9 controles vivos sadios, 3) 8 necrópsias de controles sem SEP. Foi realizado acompanhamento clínico, exame laboratorial das fezes, teste de absorção de D-xilose, avaliação da composição nutricional e digestibilidade da dieta, estudo anatomopatológico, incluindo avaliação semiquantitativa e análise morfométrica do jejuno de sagüis que foram a óbito naturalmente por SEP e dos controles. Os resultados alcançados permitiram caracterizar o perfil dos animais acometidos no nosso meio; os sinais clínicos maiores e menores da síndrome; identificar esteatorréia; o comprometimento da função digestiva e absortiva do intestino delgado dos sagüis com SEP; caracterizar o quadro histopatológico como uma enterite com atrofia semelhante à doença celíaca humana. A associação dos resultados clínicos, laboratoriais e histológicos permitiu definir a SEP como processo de má-absorção, por perda de superfície absortiva de intestino delgado, decorrente de enterite crônica imunomediada, de padrão celíaco-like que leva a progressiva e grave desnutrição secundária dos animais acometidos. / Wasting marmoset syndrome (WMS) is an important cause of morbidity and mortality of marmosets and tamarins kept in captivity. The etiology of this syndrome has not been established and its main features are progressive weight loss, diarrhea, colitis, anemia, hind limb paralysis, and alopecia. The aims of this research were to demonstrate that WMS is a malabsorption process, and to analyze the underlying histological lesion of the intestine and to characterize the local immune response of the small intestine. The sick marmosets (n=40) were compared to live normal controls (n=9) or to necropsied marmosets that died of other diseases than WMS (n=8), regarding clinical follow up, fecal analysis, D-xylose absorption test, evaluation of the nutritional composition and digestibility of the diet, gross and histological examination and morphometric approach of the jejune of wasters and control marmosets. These data revealed general features of WMS under our general captivity conditions, major and minor clinical signs of waster marmosets, impaired absorptive and digestive function of small intestine with steatorrhea and atrophic enteritis similar to celiac disease. The clinical and laboratory data associated with pathology examination demonstrated that WMS is a malabsorption process due to loss of absorptive surface area that results in progressive secondary malnutrition of the waster marmosets. The major immunologic mechanism underlying the celiac-like enteritis of WMS is a T-cell immune mediated response that affects intestine architecture

Chronic wasting disease (CWD) has infected wild deer of Saskatchewan for at least the past 10 years. Disease management plans have evolved over the years, but without information on mule deer (<i>Odocoileus hemionus</i>) habits and movements in the grasslands of southern Saskatchewan. We radio-collared and monitored the survival and movements of 206 mule deer from 2006 to 2009. Long distance movements by deer have potential to transfer disease to previously naïve areas. Survival rates had not yet been evaluated in this area; baseline data will provide a useful measure for population-level impacts of the disease in the future.<p> Juvenile dispersals and adult migrations were contrasted from 4 study areas along the South Saskatchewan River. Dispersal distance (median = 22.8 km, n = 14) was similar to migration distance (median = 16.0 km, n = 49). Median migration distance was similar between males (15.7 km, n = 51) and females (19.7 km, n = 65). Obligatory migrants were more likely to be female. Deer from an area of extensive grassland were more likely to be migratory than their counterparts in fragmented grassland of an agricultural landscape. Maximum migration and dispersal distances were 113 km and 195 km, respectively. Movement paths of 33 GPS-collared deer were best explained by high terrain ruggedness values and proximity to grassland.<p> Seasonal survival rates showed that deer had lowest survival in autumn months during hunting season. Juveniles had lower survival than adults in all seasons. Harvest regime changes in 2008 improved the autumn survival of adult females but adult males had lower survival than in 2007. Body condition of captured deer was evaluated from residuals of mass-length regression. Cox regression analyses suggested that deer in good body condition (75th percentile) were half as likely to die and that those in very poor body condition (10th percentile) were twice as likely to die. Radio collars that weighed > 2% of body mass negatively affected survival and we recommend future researchers take this into consideration. <p> Survival, dispersal, and migration rates and patterns are crucial parameters in modeling CWD in local mule deer populations. Saskatchewan wildlife managers aim to prevent CWD spread into new areas, and can use mule deer movement orientations to target surveillance accordingly. White-tailed deer (<i>Odocoileus virginianus</i>) movements are briefly discussed; further knowledge of their movements is required for CWD management in all of Saskatchewan.

Chronic wasting disease (CWD) has infected wild deer of Saskatchewan for at least the past 10 years. Disease management plans have evolved over the years, but without information on mule deer (<i>Odocoileus hemionus</i>) habits and movements in the grasslands of southern Saskatchewan. We radio-collared and monitored the survival and movements of 206 mule deer from 2006 to 2009. Long distance movements by deer have potential to transfer disease to previously naïve areas. Survival rates had not yet been evaluated in this area; baseline data will provide a useful measure for population-level impacts of the disease in the future.<p> Juvenile dispersals and adult migrations were contrasted from 4 study areas along the South Saskatchewan River. Dispersal distance (median = 22.8 km, n = 14) was similar to migration distance (median = 16.0 km, n = 49). Median migration distance was similar between males (15.7 km, n = 51) and females (19.7 km, n = 65). Obligatory migrants were more likely to be female. Deer from an area of extensive grassland were more likely to be migratory than their counterparts in fragmented grassland of an agricultural landscape. Maximum migration and dispersal distances were 113 km and 195 km, respectively. Movement paths of 33 GPS-collared deer were best explained by high terrain ruggedness values and proximity to grassland.<p> Seasonal survival rates showed that deer had lowest survival in autumn months during hunting season. Juveniles had lower survival than adults in all seasons. Harvest regime changes in 2008 improved the autumn survival of adult females but adult males had lower survival than in 2007. Body condition of captured deer was evaluated from residuals of mass-length regression. Cox regression analyses suggested that deer in good body condition (75th percentile) were half as likely to die and that those in very poor body condition (10th percentile) were twice as likely to die. Radio collars that weighed > 2% of body mass negatively affected survival and we recommend future researchers take this into consideration. <p> Survival, dispersal, and migration rates and patterns are crucial parameters in modeling CWD in local mule deer populations. Saskatchewan wildlife managers aim to prevent CWD spread into new areas, and can use mule deer movement orientations to target surveillance accordingly. White-tailed deer (<i>Odocoileus virginianus</i>) movements are briefly discussed; further knowledge of their movements is required for CWD management in all of Saskatchewan.

Social perspectives on natural resources management have become an increasingly valuable part of natural resources management decision making, especially at the policy or governance level. However, due to the range of social contexts that can exist around management questions, not every technique for incorporating stakeholders into management is suited for every management problem. My research examines the social landscape around chronic wasting disease (CWD) management on the Canadian prairies in order to identify a way forward for stakeholder involvement in CWD management. CWD is a prion disease that results in neurodegeneration and death in cervids. CWD has the potential for broad social impact because it infects elk and deer, species which are both hunted and ranched. Furthermore, management and monitoring efforts in free-ranging cervids frequently incorporate hunting activity. Q methodology was used to survey stakeholders in Saskatchewan and Manitoba and synthesize perspectives about stakeholder understanding of CWD as a problem and preferences for potential solutions. The perspectives that emerged emphasized the importance of increasing knowledge about CWD and a generalized trust in government management, coupled with a desire for stakeholder consultation under the auspices of government leadership. I found that CWD management may not be ready for stakeholder spearheaded management activity due to ambivalence and uncertainty among stakeholders, but stakeholder involvement in CWD management can still offer valuable insight for managers. This is especially notable in light of the recent loss of Saskatchewan’s CWD monitoring program.

No description available.