We compared a kinetic method (KM) and a colorimetric method (CM) for measuring erythrocyte aspartate aminotransferase (EAST) activity. Twenty-three healthy college students including 7 men and 16 women, aged from 22 to 40 years, participated in this study. Vitamin B-6 status was assessed by EAST activity coefficient (EAST-AC), the ratio of EAST stimulated activity by adding PLP in vitro (EAST-SA) to basal activity (EAST-BA). These subjects' EAST indices (EAST-BA, EAST-SA and EAST-AC) were compared to their plasma PLP concentration and their dietary intake of vitamin B-6 as determined by the food frequency questionnaire (FFQ) and 3-day dietary record. There was a significant correlation (r=0.59, p<0.01) in EAST-BA obtained by the two methods, while the correlation of EAST-SA values between the two methods was not significant (r=0.40, p=0.06). EAST-AC obtained with KM was linearly associated (r=0.57, p<0.01) to EAST-AC obtained with CM, but was 1.26 times higher (p<0.01) than that with CM. Thus, the method used for the determination of the normal EAST-AC value needs to be noted. None of EAST indices measured were significantly correlated with plasma PLP concentration. There was a high correlation for vitamin B-6 intake (r=0.65, p<0.01) and the ratio of vitamin B-6 to dietary protein (r=0.58, p<0.01) estimated between the FFQ and the 3-day dietary record. The results suggested the high validity of the FFQ for determining vitamin B-6 intake. Neither of these dietary methods was, however, correlated with any EAST activity indices or the plasma PLP concentration. / Graduation date: 1995

No description available.

Aim: To evaluate the association between elevated serum transaminase levels and insulin resistance (IR) in a population of healthy individuals. Methods: We define IR with a cut-off point of homeostatic model assessment (HOMA-IR) ≥ 3.8. For aspartate aminotransferase (AST), we consider elevated values >30 U/L in women and values >36 U/L in men. For alanine aminotransferase (ALT), we consider elevated values >30 U/L in women and values >40 U/L in men. We performed a crude and adjusted generalized linear model from Poisson family with robust variance, in order to evaluate the association between elevated serum transaminase levels and IR. The associations were presented as prevalence ratio (PR) with their respective 95% confidence intervals (95% CI). Results: We included 261 participants in the study. The median age was 39 years (31–45) and 23.7% of the participants were men. The prevalence of elevated serum transaminase for AST and ALT were, 13.8% and 26.1%, respectively. The prevalence of IR was 34.1%. In the crude analysis we found statistical significance between elevated AST and ALT with IR (PR = 3.18; 95% CI: 2.33–4.34 and PR = 2.44; 95% CI: 1.88–3.30; respectively). However, in the multivariate analysis, the association only remained statistically significance with ALT, but lost its significance with AST, PR = 1.90; CI 95%: 1.31–2.77 and a PR = 1.23; CI 95%: 0.93–1.61; respectively. Conclusion: Elevated serum levels of ALT were associated with insulin resistance. ALT could be used in clinical practice as an additional tool to assess IR in apparently healthy people. / Dirección de Gestión de la Investigación, Universidad de Antofagasta / Revisión por pares

The creation of enzymes displaying desired substrate specificity is an important objective of enzyme engineering. To help achieve this goal, computational protein design (CPD) can be used to identify sequences that can fulfill interactions required to productively bind a desired substrate. Standard CPD protocols find optimal sequences in the context of a single state, for example an enzyme structure with a single substrate bound at its active site. However, many enzymes catalyze reactions requiring them to bind multiple substrates during successive steps of the catalytic cycle. The design of multi-substrate enzyme specificity requires the ability to evaluate sequences in the context of multiple substrate-bound states because mutations designed to enhance activity for one substrate may be detrimental to the binding of a second substrate. Additionally, many enzymes undergo conformational changes throughout their catalytic cycle and the equilibrium between these conformations can have an impact on their substrate specificity. In this thesis, I present the development and implementation of two multistate computational protein design methodologies for the redesign of multi-substrate enzyme specificity and the modulation of enzyme conformational equilibrium. Overall, our approaches open the door to the design of multi-substrate enzymes displaying tailored specificity for any biocatalytic application.

Objetivo: Evaluar la asociación entre los niveles elevados de transaminasemia y resistencia a la insulina en una población de individuos sin alteraciones laboratoriales previas de glicemia, insulinemia, ni tiroideos. Métodos: Realizamos un modelo lineal generalizado crudo y ajustado de la familia Poisson con una varianza robusta, para evaluar la asociación entre los niveles elevados de transaminasemia y resistencia a la insulina. Las asociaciones se presentaron como razón de prevalencia (RP) con sus respectivos intervalos de confianza al 95%. Resultados: Se incluyeron 261 participantes. La mediana de edad fue de 39 años (31-45) y el 23,7% de los participantes eran hombres. La prevalencia de transaminasas séricas elevadas para TGO y TGP fue de 13.8% y 26.1%, respectivamente. La prevalencia de resistencia a la insulina fue del 34,1%. En el análisis en bruto encontramos significancia estadística entre TGP y TGO elevados y resistencia a la insulina (RP = 3,18; IC del 95%: 2,33-4,34 y RP = 2,44; IC del 95%: 1,88 a 3,30; respectivamente). Sin embargo, en el análisis multivariado ajustado, la asociación entre el nivel elevado de transaminasas séricas y la resistencia a la insulina permaneció estadísticamente significativa con TGP, pero se perdió con TGO; un PR = 1.90; CI95%: 1.31-2.77 y un PR = 1.23; CI95%: 0,93-1,61; respectivamente. Conclusión: niveles séricos elevados de TGP se asociaron con resistencia a la insulina. TGP podría usarse en la práctica clínica como una herramienta adicional para evaluar la resistencia a la insulina en personas sin alteraciones laboratoriales previas de glicemia, insulinemia, ni tiroideos. / Aim: To evaluate the association between elevated serum transaminase levels and insulin resistance in a population of individuals without alterations in their laboratorial values of glycemia, insulinemia and thyroid panel. Methods: We performed a crude and adjusted generalized linear model of the Poisson family with robust variance, in order to evaluate the association between elevated serum transaminase levels and insulin resistance. The associations were presented as prevalence ratio (PR) with their respective 95% confidence intervals (95% CI). Results: We included 261 participants in the study. The median age was 39 years (31-45) and 23,7% of the participants were men. The prevalence of elevated serum transaminase for TGO and TGP were, 13.8% and 26.1%, respectively. The prevalence of insulin resistance was 34,1%. In the crude analysis we found statistical significance between elevated TGP and TGO and insulin resistance (PR=3,18; 95% CI: 2,33-4,34 and PR=2.44; 95% CI: 1.88-3.30; respectively). However, in the multivariate analysis adjusted for age, sex, body mass index and thyroid hormones, the association between the elevated serum transaminase level and insulin resistance remained statistically significance with TGP, but lost its significance with TGO; a PR = 1.90; CI95%: 1.31-2.77 and a PR = 1.23; CI95%: 0.93-1.61; respectively. Conclusion: Elevated serum levels of TGP were associated with insulin resistance. TGP could be used in clinical practice as an additional tool to assess insulin resistance in people without laboratorial alterations in glycemia, insulinemia and thyroid panel. / Tesis

Submitted by JULIANA APARECIDA CERQUEIRA null (julianacerqueira.vet@gmail.com) on 2017-08-16T14:34:40Z No. of bitstreams: 1 Dissertação PDF.pdf: 1523644 bytes, checksum: 34b73cfc23737b94845062cc56505e49 (MD5) / Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-08-22T20:39:49Z (GMT) No. of bitstreams: 1 cerqueira_ja_me_jabo.pdf: 1523644 bytes, checksum: 34b73cfc23737b94845062cc56505e49 (MD5) / Made available in DSpace on 2017-08-22T20:39:49Z (GMT). No. of bitstreams: 1 cerqueira_ja_me_jabo.pdf: 1523644 bytes, checksum: 34b73cfc23737b94845062cc56505e49 (MD5) Previous issue date: 2017-07-28 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / As principais alterações fisiológicas ou patológicas induzidas pelo exercício que ocorrem na musculatura esquelética ou cardíaca podem ser identificadas por meio de biomarcadores séricos. Consolidados em atletas da espécie humana e equina, são praticamente inexistentes em cães estudos sobre a dinâmica destes biomarcadores relacionados com a prática de exercício máximo e treinamento. Objetivou-se determinar a cinética dos biomarcadores séricos musculares creatina quinase (CK), aspartato aminotransferase (AST), mioglobina; e cardíacos, troponina cardíaca I (cTnI) e creatina quinase isoenzima MB (CK-MB) de cães submetidos a esforço intenso e condicionamento aeróbio. A ação da venopunção sobre os biomarcadores também foi avaliada. Foram utilizados 18 cães hígidos da raça Beagle distribuídos em três grupos: sedentário (S), não treinado (NT) e treinado (T). Os cães foram submetidos a dois testes de esforço incremental (TEI-1 e TEI-2) para obtenção da curva lactato-velocidade (CLV). Verificou-se se a CLV teve modelo exponencial. O programa de treinamento foi realizado em esteira por 8 semanas na velocidade relacionada a 70-80 % do limiar de lactato (VLL). Determinou-se a velocidade correspondente a frequência cardíaca no momento da fadiga (VFCFadiga). Os biomarcadores séricos foram quantificados nos momentos basal, antes e 1, 6, 12, 24, 48 e 72 h após os TEIs. Aplicou-se análise de variância de dois fatores para amostras repetidas no tempo seguida por teste de Tukey e correlação de Pearson (P≤0,05). Elevação (P≤0,05) das velocidades correspondentes a VLL e VFCFadiga evidenciou melhora da aptidão aeróbia do grupo T. Observou-se aumento (P≤0,05) na atividade sérica de CK e AST, com valores máximos após 6 h em ambos os TEIs, com retorno aos valores basais após 12-24 h. Em conjunto, a avaliação do comportamento dos biomarcadores musculares revelou recuperação do tecido muscular após os TEIs. A cTnI e a mioglobina não se alteraram. A CK-MB apresentou pico de elevação (P≤0,05) após 1 h e retorno aos valores basais após 12 h em ambos os TEIs, apontando ausência de lesões musculares cardíacas. Observou-se forte correlação entre CK-AST (P=0,849) e correlação moderada entre CK-CK-MB (0,493) e AST-CK-MB (0,501). Parece que as atividades séricas da CK e AST podem sofrer interferência da venopunção jugular. Conclui-se que o exercício intenso provocou aumento fisiológico das atividades séricas das enzimas musculares e cardíacas com rápida recuperação, sem indicativo de lesões. O protocolo de condicionamento físico melhorou o rendimento dos cães, mas não influenciou a atividade sérica das enzimas musculares e cardíacas. Para o monitoramento desportivo em cães a CK-MB foi o biomarcador mais confiável. / The main physiological or pathological alterations induced by exercise on skeletal or cardiac musculature can be identified using serum biomarkers. While studies on the dynamics of such biomarkers are consolidated in humans and horses, they are virtually inexistent on maximum exercise and training among dogs. This study aimed to determine the kinetics of the muscle serum biomarkers creatine kinase (CK), aspartate aminotransferase (AST), and myoglobin and of cardiac biomarkers cardiac troponin I (cTnI) and creatine kinase isoenzyme MB (CK-MB) of dogs subjected to intense effort and aerobic conditioning. The effect of venipuncture on the biomarkers was also assessed. Eighteen healthy Beagle dogs were assigned to three groups: sedentary (S), untrained (U), and trained (T). The dogs were subjected to two incremental effort tests (IET-1 and IET-2) so that their lactate vs. velocity curve (LVC) could be obtained. It was verified whether LVC followed an exponential model. The eight-week training program was carried out on a treadmill with speed set to 70-80% of the velocity at lactate threshold (VLT). The velocity corresponding to the heart rate at the moment of fatigue (VHRFatigue) was determined. Serum biomarkers were quantified at the baseline, before, and 1, 6, 12, 24, 48, and 72 h after the IETs. Two-factor analysis of variance was applied for samples repeated over time followed by Tukey’s test and Pearson correlation (P≤0.05). The increase (P≤0.05) in the velocyties corresponding to VLT and VHRFatigue indicated an improvement in aerobic fitness of group T. Serum activity of CK and AST increased (P≤0.05), reached maximum values after 6 h in both IETs, and returned to baseline levels after 12-24 h. As a whole, the assessment of the behavior of muscle biomarkers showed recovery of muscle tissues after the IETs. Levels of cTnI and myoglobin were unaltered. Peak CK-MB (P≤0.05) was observed 1 h into the IETs and returned to baseline levels 12 h after they finished, indicating no cardiac muscle lesions. A strong correlation between CK and AST (P=0.849) and moderate correlations between CK and CK-MB (0.493) and AST and CK-MB were observed. Apparently, serum activities of CK and AST may be impacted by jugular venipuncture. It is concluded that intense exercise led to a physiological increase in serum activities of muscle and cardiac enzymes with rapid recovery and no apparent lesions. The physical conditioning protocol improved the performance of the dogs, but did not impact the serum activity of muscle and cardiac enzymes. CK-MB was the most reliable sports monitoring biomarker in dogs. / CNPq: 132811/2016-2

The objective of the present work was to identify serum copper levels and aspartateaminotransferase (AST) and gamagluthamyl transferase (GGT) activity in purebred show and field raised sheep and to contribute to formation of regional reference values. Blood samples of 120 show sheep and 110 field raised animals were collected independently of age, sex and breed. Means serum levels of copper for show and field sheep 66.14 ± 9.76 and 62.01 ±16.36 μg.dl-1 (P<0.0357), respectively; AST activity was higher in show sheep than in field animals (85.01 ±40.02 vs. 65.58 ±16.19 IU, P<0.0001); GGT activity was 41.02 ±10.61 and 41.91 ±9.49 IU with no differences between groups. In conclusion, serum copper levels in all show animals were within international reference values, whereas field raised animals presented several individuals that fell bellow the lower limit. Serum activitiy of AST and GGT appear not to be related to copper metabolism in these animals. / O objetivo desse trabalho foi identificar as concentrações séricas de cobre e enzimas aspartatoaminotransferase (AST) e gamaglutamiltransferase (GGT) tanto em ovinos preparados para exposição como criados a campo, a fim de contribuir para a formação de valores de referência e auxiliar no prognóstico da saúde desses animais. Colheram-se 120 amostras de sangue de animais de exposição e 110 de animais de campo, independente de sexo, raça e idade. Os níveis séricos médios de cobre, AST e GGT dos animais de exposição e a campo foi igual a 66,14 ±9,76 e 62,01 ±16,36 μg.dl-1 (P<0,0357); 85,01 ±40,02 e 65,58 ±16,19 UI (P<0,0001); 41,02 ±10,61 e 41,91 ±9,49 UI, respectivamente. Em conclusão, as médias do elemento cobre de animais preparados para exposição mostraram-se dentro dos valores de referência e as de alguns animais mantidos a campo abaixo do intervalo fisiológico. Os níveis séricos de AST e GGT aumentados no grupo exposição parecem não estar relacionados com o acúmulo hepático de cobre.

No description available.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2014-11-07T10:55:53Z No. of bitstreams: 2 Dissertação - Mirian de Sylvio - 2009.pdf: 865608 bytes, checksum: bba24a89ef1938c31376520a3eff1e60 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2014-11-07T11:29:38Z (GMT) No. of bitstreams: 2 Dissertação - Mirian de Sylvio - 2009.pdf: 865608 bytes, checksum: bba24a89ef1938c31376520a3eff1e60 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-11-07T11:29:38Z (GMT). No. of bitstreams: 2 Dissertação - Mirian de Sylvio - 2009.pdf: 865608 bytes, checksum: bba24a89ef1938c31376520a3eff1e60 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2009-12-15 / Infection with Toxoplasma gondii occurs throughout the globe, with a prevalence of up to 90% in the population. The physiological changes caused by this parasite are well studied in immunocompromised individuals and in cases of congenital transmission. In immunocompetent individuals the infection is usually asymptomatic and little explored by researchers. Experimental studies follow the pattern of human studies, and there fow mention about the biochemical changes (liver and kidney metabolisms) in the host infected by T. gondii. This study aimed the quantification of hepatic and kidney alterations caused by acute infections by T. gondii (non cystogenic strain – RH) and by chronic infections (cystogenic strain – ME-49). The control group was formed by mice without infection, only submitted to saline stress. Several enzymes were measured in serum and peritoneal exudate of mice infected and control such as: aspartate aminotransferase (AST), alanine aminotransferase (ALT), glutamyltransferase (GGT), alkaline phosphatase (ALP), urea, creatinine and lactate dehydrogenase, using an automated methodology. AST and ALT presented a significative difference in the serum of mice infected with RH strain when compared to controls indicating a destruction of liver cells. The peritoneal exudates did not present significative changes in relation to controls nor did the urea and creatinine levels. The séric lactate dehydrogenase showed gradual changes in all days of the infection in mice peritoneal exudates as early as this change was evident only in the fifth day of infection. All samples of the group infected with ME-49 strain showed changes in serum and peritoneal exudate during all days of analysis. Only ALT peritoneal exudates showed no change during all days of analysis. An increase in urea at all doses was observed, however, creatinine showed a change only within 120 days of infection. The LDH was altered in the serum in all days of analysis. In conclusion, the T. gondii infection may cause hepatic and kidney injuries either when caused by non-cystogenic as by cystogenic strains of the parasite. / A infecção pelo Toxoplasma gondii ocorre em todo o mundo, com prevalência de até 90% na população conforme seus hábitos culturais e condições socioeconômicas. As alterações fisiopatológicas provocadas por este parasito são muito estudadas nos indivíduos imunocomprometidos, nos casos de transmissão congênita, e nos indivíduos imunocompetentes a infecção é, geralmente, assintomática e pouco explorada pelos pesquisadores. Experimentalmente, os estudos seguem o padrão dos estudos humanos, e há pouca referência sobre as alterações bioquímicas (hepáticas e renais) no hospedeiro infectado pelo T. gondii. Este trabalho objetivou avaliar as alterações hepáticas e renais causadas por esse parasito em camundongos na fase aguda, usando a cepa não cistogênica (RH), e na fase crônica, com a cepa cistogênica (ME-49), tendo como controles camundongos sem infecção, somente submetidos ao estresse de inoculação com salina. Foram dosadas no soro e no exsudato peritoneal dos camundongos infectados e controles os níveis das enzimas Aspartato aminotransferase (AST), Alanina aminotransferase (ALT), Gamaglutamiltransferase (GGT), Fosfatase alcalina (FAL), desidrogenase lática (DHL) e dos seguintes compostos: uréia e creatinina, por metodologia automatizada. As enzimas AST e ALT apresentaram diferença significativa no soro de camundongos infectados com cepa RH, demonstraram alterações em relação aos controles indicando uma destruição das células hepáticas. No exsudato peritoneal não foram demonstradas alterações em relação aos controles. A uréia e creatinina dosadas não demonstraram alteração significativa. A enzima lactato desidrogenase sérica apresentou alterações gradativas em todos os dias de infecção do camundongo no soro, já no exsudato peritoneal essa alteração foi evidenciada somente no quinto dia da infecção, mostrando que com o aumento de parasitos e a destruição celular causada por esse, essa enzima presente em várias células é responsável por demonstrar aumentos consideráveis. Todas as amostras de soro analisadas do grupo infectado com a cepa ME-49 demonstraram alterações durante todo período de acompanhamento. Enquanto que no exsudato peritoneal não mostrou nenhuma alteração durante todo período analisado. Houve aumento crescente na uréia em todos os dias de analises, porém, a creatinina não apresentou nenhuma alteração. A LDH mostrou-se alterada no soro em todos os dias de analisado. Conclui-se que a infecção pelo T. gondii pode provocar alterações hepáticas e renais ao longo do curso de infecção, tanto em infecções com cepa cistogênica quanto com cepa não cistogênica.