Made available in DSpace on 2014-06-11T19:25:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-08-28Bitstream added on 2014-06-13T19:53:40Z : No. of bitstreams: 1 gasparelli_erf_me_araca.pdf: 500187 bytes, checksum: 20384c22730ccd6e17828305c437e923 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Foram acompanhados 310 parturições de receptoras, com embriões fertilizados in vivo (FV) e in vitro (FIV) da raça Nelore, para determinar os índices de partos distócicos em receptoras meio sangue das raças Braford/Nelore, Hereford/Nelore, Simental/Nelore, Red Angus/Nelore, Nelore e anelorados, com idade entre três e seis anos, assim como avaliar o estado de saúde dos bezerros obtidos por intermédio de transferência de embriões, resultantes das técnicas de fertilização in vivo (FV) ou fertilização in vitro (FIV). Observou-se a ocorrência de 38 partos distócicos (38/310) e oito abortos (8/310), dos quais cinco fetos eram oriundos da técnica de fertilização in vivo (FV) e três da técnica de fertilização in vitro (FIV). A taxa de mortalidade em animais neonatos foi de 3,4% (10/290). Os bezerros nascidos de partos distócicos mais duradouros, entre quatro e seis horas, apresentaram os maiores valores médios de freqüência respiratória. A temperatura retal foi mais elevada em animais nascidos de partos laboriosos do que naqueles nascidos de partos normais. / Three hundred and ten parturitions of receivers were accompanied, with Nellore embryos fertilized in vivo (FV) and in vitro (FIV), to determine the indices of dystocic calving in Braford/Nellore, Hereford/Nellore, Simental/Nellore, Red Angus/Nellore, Nellore and Zebu crossbreed recipients cows, aged between three and six years, as well as, to evaluate health condition of calves obtained through embryos transfer, resulting from in vivo fertilization (FV) and in vitro fertilization (FIV) techniques. The occurrence of 38 dystocic calving (38/310) and eight abortions (8/310) were observed, in which five embryos were arisen by in vivo fertilization technique (FV) and three embryos by in vitro fertilization technique (FIV). In neonate animals, the mortality rate was 3,2% (10/310). Calves born by lasting dystocic calving, between four and six hours, presented the biggest average values of respiratory frequency. Animals born by laborious calving showed higher retal temperature than those born by normal calving.

Tyrosine is involved in many biological processes including protein synthesis. This dissertation is focused on two different aspects: tyrosine catabolism and tyrosine derivative metabolism. Tyrosine undergoes degradation via tyrosine aminotransferase (TAT). Deficiency of TAT leads to some disease conditions or tyrosinemia type II. TAT has been characterized in several species, including humans. Mouse tyrosine aminotransferase was used as a model protein for the tyrosine catabolism portion of this study. Characterization of TAT included its expression in a bacterial expression system, purification using various chromatographic techniques, crystallization under different conditions, and its kinetic analysis, and molecular dynamics simulations. Based on sequence, structure, and kinetic data we have shown that mouse TAT behaves like human TAT. Our crystallization studies added new insights into the mechanism of TAT by shedding light on involvement of a disulfide bond in the regulation of mTAT. Molecular dynamics analysis provided perspective on the differences (preferences) in the substrate specificities of mouse and Trypanosome cruzi TAT. Tyrosine is a precursor of several key neurotransmitters. These neurotransmitters must be regulated in order to function properly. The hypothetical N-acetyltransferases from Aedes aegypti were used as model proteins for investigation of tyrosine derivative metabolism. We found nine potential arylalkylamine N-acetyltransferase (AANAT) genes in Ae. aegypti. Phylogenetic analysis suggests that these Ae. aegypti AANATs (AeAANATs) can be further divided into three clusters. Phylogenetic analysis suggests that insect AANATs may have different functions as compared with the mammalian AANATs, for which function is specific to circadian rhythm regulation. PCR amplification indicates that eight of the nine putative AeAANATs are expressed in the mosquito. Expression of the eight putative AeAANATs and substrate screening of their recombinant proteins against dopamine, octopamine, tyramine, epinephrine, tryptamine, 5-hydroxytryptamine, and methoxytryptamine established that five of the eight putative AeAANATs are true AANATs. The discontinuous expression profiles of AeAANAT genes were studied in detail. Six of the AeAANATs were expressed in the head before and after blood feeding, suggesting their potential role in neurotransmission inactivation. Down-regulation of these genes after blood feeding suggests that blood feeding or factors related to blood feeding impact on the regulation of these genes. Kinetic studies determined that two AeAANAT proteins are highly efficient in mediating the acetylation of dopamine and 5-hydroxytryptamine. Substrate analysis of AeAANATs supports the notion that acetylation of arylalkylamines is vital to the biology of mosquito species, and that these genes emerged in response to specific pressures related to necessities for biogenic amine acetylation. / Ph. D.

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

Ornithine-$ delta$-biaminotransferase (OAT) is a mitochondrial matrix a enzyme which catalyzes the reversible conversion of ornithine to glutamic semialdehyde. In the retinoblastoma cell line Y79, the 5$ sp prime$ UTR of the OAT mRNA is alternatively-spliced. Previous work has shown that the two alternatively-spliced 5$ sp prime$ UTR are translated with different efficiencies. / The alternatively-spliced 5$ sp prime$ UTRs were isolated and subcloned. Expression vectors were constructed containing each of the OAT 5$ sp prime$ UTRs and the human growth hormone as a reporter gene. Transient transfection expression analysis in COS-1 cells confirmed that the 5$ sp prime$ UTRs conferred differential expression on the reporter gene. The shorter 5$ sp prime$ UTR was expressed at a level 3-fold higher than that of the longer 5$ sp prime$ UTR. / RNA mobility shift assays were performed to determine whether a transacting factor was interacting with one of the alternatively-spliced 5$ sp prime$ UTRs. A binding activity was detected that bound to the longer, exon 2-containing 5$ sp prime$ UTR with a significantly higher affinity than the shorter 5$ sp prime$ UTR. Competition studies demonstrated that this binding activity was specific for the longer 5$ sp prime$ UTR.

Orientador: Francisco Leydson Formiga Feitosa / Banca: Alice Maria Melville Paiva Della Libera / Banca: José Jurandir Agliari / Resumo: Foram acompanhados 310 parturições de receptoras, com embriões fertilizados in vivo (FV) e in vitro (FIV) da raça Nelore, para determinar os índices de partos distócicos em receptoras meio sangue das raças Braford/Nelore, Hereford/Nelore, Simental/Nelore, Red Angus/Nelore, Nelore e anelorados, com idade entre três e seis anos, assim como avaliar o estado de saúde dos bezerros obtidos por intermédio de transferência de embriões, resultantes das técnicas de fertilização in vivo (FV) ou fertilização in vitro (FIV). Observou-se a ocorrência de 38 partos distócicos (38/310) e oito abortos (8/310), dos quais cinco fetos eram oriundos da técnica de fertilização in vivo (FV) e três da técnica de fertilização in vitro (FIV). A taxa de mortalidade em animais neonatos foi de 3,4% (10/290). Os bezerros nascidos de partos distócicos mais duradouros, entre quatro e seis horas, apresentaram os maiores valores médios de freqüência respiratória. A temperatura retal foi mais elevada em animais nascidos de partos laboriosos do que naqueles nascidos de partos normais. / Abstract: Three hundred and ten parturitions of receivers were accompanied, with Nellore embryos fertilized in vivo (FV) and in vitro (FIV), to determine the indices of dystocic calving in Braford/Nellore, Hereford/Nellore, Simental/Nellore, Red Angus/Nellore, Nellore and Zebu crossbreed recipients cows, aged between three and six years, as well as, to evaluate health condition of calves obtained through embryos transfer, resulting from in vivo fertilization (FV) and in vitro fertilization (FIV) techniques. The occurrence of 38 dystocic calving (38/310) and eight abortions (8/310) were observed, in which five embryos were arisen by in vivo fertilization technique (FV) and three embryos by in vitro fertilization technique (FIV). In neonate animals, the mortality rate was 3,2% (10/310). Calves born by lasting dystocic calving, between four and six hours, presented the biggest average values of respiratory frequency. Animals born by laborious calving showed higher retal temperature than those born by normal calving. / Mestre

No description available.

No description available.

Ornithine Aminotransferase (OAT) is expressed at high levels in liver, kidney, and retina. Tissue-specific regulation of OAT has been described for rat kidney and liver. To characterize OAT regulation in retinal lines, we studied OAT synthesis in retinoblastomas RB355 and Y79. / OAT transcription and mRNA levels in the two lines were similar, but 3-fold greater immunoreactive OAT protein and enzyme activity were observed for Y79. Characterization of polysome-associated OAT mRNAs indicated that they were translated less efficiently, due to decreased initiation, in RB355. Initiation factor eIF-4E mRNA and protein were reduced in RB355; eIF-4E overexpression in RB355 increased OAT translation and OAT protein to the level observed in Y79. / Estrogen and thyroid hormone increased OAT expression in both strains. Estrogen increased translational initiation, with no effect on transcription, whereas thyroid hormone was primarily a transcriptional activator. / An alternatively-spliced OAT mRNA was identified in these retinoblastomas; this mRNA was poorly translated and was not affected by eIF-4E overexpression, estrogen, or thyroid hormone. / This study has demonstrated several post-transcriptional regulatory mechanisms for OAT in retinal tissue.

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

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