Determinação da estrutura e estudo da função da metalotioneína de Synechococcus com ferramentas da bioinformática.

Este trabalho abordou a análise estrutural das MTs a fim de se modelar esta proteína e com isso compreender melhor o funcionamento da mesma. O conhecimento da cianobactéria e uma completa análise da MT poderia ser muito útil em um estudo de utilização desta na técnica da biorremediação para remover metais pesados do solo e da água decorrentes das praticas agrícolas atuais.bitstream/CNPTIA/9902/1/comuntec43.pdfAcesso em: 30 maio 2008

The physiological dilemma of the high progesterone syndrome in rabbit does

This work focused on the mechanisms that may cause multiple asynchronous ovulations and alter normal ovarian function in order to characterize the high progesterone (P+) syndrome in rabbit does, that, having abnormally high plasma progesterone concentration at the time of insemination, fail to become pregnant. At different luteal stages, at either days 4, 9, or 13 of pseudopregnancy, induced by GnRH injection (d-0), two groups of rabbits (n=5/group) were treated with saline or 0.8 \ub5g GnRH. Blood samples were collected from d-0 to d-26 of pseudopregnancy. At d-4, GnRH injection prolonged (P<0.05) the functional CL life span by 3 to 4 d over that of controls. At d-9, GnRH caused a transient decline (P<0.01) of progesterone for the following 3 d but, thereafter, increased again and remained higher (P<0.01) than controls up to d-26. At d-13, progesterone fell to 1 ng/ml within one day following GnRH, but then gradually increased. Based of these progesterone profiles, it can be argued that, at both mid- and late-luteal phase, GnRH triggered luteolysis and induced ovulation followed by the formation of a new generation of CL. For the in vitro study, CL, collected at days 4, 9, and 13 of pseudopregnancy, were incubated with GnRH, GnRH-antagonist, PLA2 inhibitor, and PLC inhibitor. GnRH decreased (P<0.01) progesterone secretion by d-9 and d-13 CL cultured in vitro; by converse, GnRH antagonist, increased (P<0.01) progesterone release from d-4 CL. Co-incubation of GnRH with GnRH antagonist increased (P<0.01) progesterone release in d-4 CL, but had an opposite effect (P<0.01) on d-9 and d-13 CL. PLC inhibitor reversed the GnRH effects in both d-9 and d-13 CL, while PLA2 inhibitor did not change progesterone release. These data suggest that rabbit CL express a functional receptor for GnRH, likely of type II, that utilizes the PLC post transductional cascade. Luteal FSH-R and LH-R mRNA relative abundances did not differ between d-4 and d-9 CL, but were two- to three-fold (P 640.01) higher, respectively, at d-13. StAR mRNA was highly expressed at d-4 of pseudopregnancy, but then markedly declined (P 640.01) at d-9 and d-13. Taken together, our results show that GnRH triggers i) functional regression when CL acquire luteolytic capacity from d 9 of pseudopregnancy onward, and ii) multiple asynchronous ovulations, thus partly explaining the P+ syndrome associated with the simultaneous coexistence of two population of \u201cfresh\u201d and \u201cold\u201d CL, although not yet the underlying causes

Expression patterns of cytokines, p53 and nitric oxide synthase enzymes in corpora lutea of pseudopregnant rabbits during spontaneous luteolysis

The gene expressions for macrophage chemoattractant protein-1 (MCP-1), interleukin (IL)-1 beta, IL-2 and p53 were examined by semi-quantitative RT-PCR in corpora lutea (CL) of rabbits during spontaneous luteolysis at days 13, 15, 18 and 22 of pseudopregnancy. In the same luteal tissue, total activity of nitric oxide (NO) synthase (NOS) and genes for both endothelial (eNOS) and inducible (iNOS) isoforms were also analysed. From day 13 to 15, MCP-1 and IL-1 beta mRNA levels rose (P < or = 0.01) almost 2-fold, and the transcript for p53 almost 8-fold, but then all dropped (P < or = 0.05) from day 18 onward. IL-2 mRNA abundance was higher (P < or = 0.01) on day 13 and then gradually declined. During luteolysis, eNOS mRNA decreased 40% (P < or = 0.05) by day 15, but thereafter remained unchanged, while iNOS mRNA was barely detectable and did not show any clear age-related pattern throughout the late luteal stages. Total NOS activity progressively increased (P < or = 0.01) from day 13 to 18 of pseudopregnancy and then dropped to the lowest (P < or = 0.01) levels on day 22. Luteal progesterone content also declined during CL regression from 411 to 17 pg/mg found on days 13 and 22 respectively, in parallel with the decrease in blood progesterone concentrations. These data further support a physiological role of NO as modulator of luteal demise in rabbits. Locally, luteal cytokines may be involved in the up-regulation of NOS activity, while downstream NO may inhibit steroroidogenesis and induce expression of p53 gene after removal of the protective action of progesterone

High-intensity interval exercise induces greater acute changes in sleep, appetite-related hormones, and free-living energy intake than does moderate-intensity continuous exercise

© 2019, Canadian Science Publishing. All rights reserved. The aim of this study was to compare the effect of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) on sleep characteristics, appetite-related hormones, and eating behaviour. Eleven overweight, inactive men completed 2 consecutive nights of sleep assessments to determine baseline (BASE) sleep stages and arousals recorded by polysomnography (PSG). On separate afternoons (1400–1600 h), participants completed a 30-min exercise bout: either (i) MICE (60% peak oxygen consumption) or (ii) HIIE (60 s of work at 100% peak oxygen consumption: 240 s of rest at 50% peak oxygen consumption), in a randomised order. Measures included appetite-related hormones (acylated ghrelin, leptin, and peptide tyrosine tyrosine) and glucose before exercise, 30 min after exercise, and the next morning after exercise; PSG sleep stages; and actigraphy (sleep quantity and quality); in addition, self-reported sleep and food diaries were recorded until 48 h after exercise. There were no between-trial differences for time in bed (p = 0.19) or total sleep time (p = 0.99). After HIIE, stage N3 sleep was greater (21% ± 7%) compared with BASE (18% ± 7%; p = 0.02). In addition, the number of arousals during rapid eye movement sleep were lower after HIIE (7 ± 5) compared with BASE (11 ± 7; p = 0.05). Wake after sleep onset was lower following MICE (41 min) compared with BASE (56 min; p = 0.02). Acylated ghrelin was lower and glucose was higher at 30 min after HIIE when compared with MICE (p ≤ 0.05). There were no significant differences between conditions in terms of total energy intake (p ≥ 0.05). HIIE appears to be more beneficial than MICE for improving sleep quality and inducing favourable transient changes in appetite-related hormones in overweight, inactive men. However, energy intake was not altered regardless of exercise intensity

A Genome-wide gene-expression analysis and database in transgenic mice during development of amyloid or tau pathology

We provide microarray data comparing genome-wide differential expression and pathology throughout life in four lines of "amyloid" transgenic mice (mutant human APP, PSEN1, or APP/PSEN1) and "TAU" transgenic mice (mutant human MAPT gene). Microarray data were validated by qPCR and by comparison to human studies, including genome-wide association study (GWAS) hits. Immune gene expression correlated tightly with plaques whereas synaptic genes correlated negatively with neurofibrillary tangles. Network analysis of immune gene modules revealed six hub genes in hippocampus of amyloid mice, four in common with cortex. The hippocampal network in TAU mice was similar except that Trem2 had hub status only in amyloid mice. The cortical network of TAU mice was entirely different with more hub genes and few in common with the other networks, suggesting reasons for specificity of cortical dysfunction in FTDP17. This Resource opens up many areas for investigation. All data are available and searchable at http://www.mouseac.org

Evening high-intensity interval exercise does not disrupt sleep or alter energy intake despite changes in acylated ghrelin in middle-aged men

© 2019 The Authors. Experimental Physiology © 2019 The Physiological Society New Findings: What is the central question of this study? What are the interactions between sleep and appetite following early evening high-intensity interval exercise (HIIE)? What is the main finding and its importance? HIIE can be performed in the early evening without subsequent sleep disruptions and may favourably alter appetite-related hormone concentrations. Nonetheless, perceived appetite and energy intake do not change with acute HIIE regardless of time of day. Abstract: Despite exercise benefits for sleep and appetite, due to increased time restraints, many adults remain inactive. Methods to improve exercise compliance include preferential time-of-day or engaging in short-duration, high-intensity interval exercise (HIIE). Hence, this study aimed to compare effects of HIIE time-of-day on sleep and appetite. Eleven inactive men undertook sleep monitoring to determine baseline (BASE) sleep stages and exclude sleep disorders. On separate days, participants completed 30 min HIIE (60 s work at 100% (Formula presented.), 240 s rest at 50% (Formula presented.)) in (1) the morning (MORN; 06.00–07.00 h), (2) the afternoon (AFT; 14.00–16.00 h) and (3) the early evening (EVEN: 19.00–20.00 h). Measures included appetite-related hormones (acylated ghrelin, leptin, peptide tyrosine tyrosine) and glucose pre-exercise, 30 min post-exercise and the next morning; overnight polysomnography (PSG; sleep stages); and actigraphy, self-reported sleep and food diaries for 48 h post-exercise. There were no between-trial differences for total sleep time (P = 0.46). Greater stage N3 sleep was recorded for MORN (23 ± 7%) compared to BASE (18 ± 7%; P = 0.02); however, no between-trial differences existed (P > 0.05). Rapid eye movement (REM) sleep was lower and non-REM sleep was higher for EVEN compared to BASE (P ≤ 0.05). At 30 min post-exercise, ghrelin was higher for AFT compared to MORN and EVEN (P = 0.01), while glucose was higher for MORN compared to AFT and EVEN (P ≤ 0.02). No between-trial differences were observed for perceived appetite (P ≥ 0.21) or energy intake (P = 0.57). Early evening HIIE can be performed without subsequent sleep disruptions and reduces acylated ghrelin. However, perceived appetite and energy intake appear to be unaffected by HIIE time of day

Pharmacokinetics and pharmacodynamics of a therapeutic dose of unfractionated heparin (200 U/kg) administered subcutaneously or intravenously to healthy dogs

Objectives: To evaluate the effects of 200 U/kg of sodium unfractionated heparin (UFH) on coagulation times in dogs after IV and SC administration and to compare these effects with plasma heparin concentrations assessed by its anti Xa activity. Methods: 200 U/kg of UFH were administered Intravenously (IV) and Subcutaneously (SC) to five healthy adult Beagle dogs with a wash out period of at least 3 days. Activated Partial Thromboplastin Time (APTT), Prothrombin Time (PT) and plasma anti-factor Xa (aXa) activity were determined in serial blood samples. Results: After IV injection, PT remained unchanged except for a slight increase in one dog; APTT was not measurable (> 60 s) for 45 to 90 min, then decreased regularly and returned to baseline values between 150 and 240 min. High plasma heparin concentrations were observed (C max = 4.64±1.4 aXa U/mL) and decreased according to a slightly concave-convex pattern on a semi-logarithmic curve but returned to baseline slightly more slowly (t240 to t300 min). After SC administration, APTT was moderately prolonged (mean±SD prolongation: 1.55±0.28 x APTT t0, range [1.35-2.01]) between 1 and 4 hours after administration. Plasma anti-factor Xa activity reached a maximum of 0.56±0.20 aXa U/mL, range: [0.42 - 0.9] after 132±26.8 min and this lasted for 102±26.8 min. Heparin concentrations were grossly correlated to APTT; prolongation of APTT of 120 to 160% corresponded to plasma heparin concentrations range of 0.3-0.7 aXa U/mL, considered as the therapeutic range in human medicine. Conclusions: As in human, pharmacokinetic of UFH in dogs is non linear. Administration of 200 U/kg of UFH SC in healthy dogs results in sustained plasma heparin concentrations in accordance with human recommendations for thrombosis treatment or prevention, without excessively increased bleeding risks. In these conditions, APTT can be used as a surrogate to assess plasma heparin concentrations. This has to be confirmed in diseased animals

Role of endothelin-1 system in the luteolytic process of pseudopregnant rabbits

The aim of this study was to better understand the role of the endothelin-1 (ET-1) system in the process of controlling the corpora lutea (CL) life span in rabbits. ET-1 (10 mug iv) administration at d 9 and 12 of pseudopregnancy induced a functional luteolysis within 24 h of injection, but it was ineffective at both d 4 and 6. Pretreatments with Bosentan, a dual ETA/ETB receptor antagonist, or cyclooxygenase ( COX) inhibitor blocked the luteolytic action of ET-1 but not that induced by prostaglandin F-2alpha (PGF(2alpha)). In CL cultured in vitro, ET-1 increased (P less than or equal to 0.01) both PGF(2alpha) production and luteal nitric oxide synthase activity but decreased (P less than or equal to 0.01) progesterone release. Addition of ETA receptor antagonist BQ123 or COX inhibitor blocked the ET-1 luteolytic effects. Positive staining for ET-1 receptors was localized in ovarian blood vessels, granulosa cells of large follicles, and luteal cells. Immunoblot analysis of ET-1 receptor protein revealed a strong band of approximately 48 kDa in d-9 CL. Up to d 6 of pseudopregnancy, ET-1 mRNA abundance in CL was poorly expressed but then increased (P less than or equal to 0.01) at d 9 and 13. ETA-receptor transcript increased (P less than or equal to 0.01) at d 6, remained at the same level up to d 13, and then declined to the lowest (P less than or equal to 0.01) levels at d 22. ETB-receptor mRNA increased (P less than or equal to 0.01) throughout the late-luteal stage from d 13 up to d 18. Our data suggest that the luteolytic action of ET-1 may be a result of PGF(2alpha) synthesis from both luteal and accessory cells, via the COX pathways

Leptin receptor expression and in vitro leptin actions on prostaglandin release and nitric oxide synthase activity in the rabbit oviduct

In this study, we have examined the presence and the distribution of receptors for leptin (Ob-R) in the oviduct of rabbits, and the effects of leptin on the release of prostaglandin (PG) F2alpha and PGE2 and on the activity of nitric oxide (NO) synthase (NOS) by oviducts cultured in vitro. Rabbits were killed during the follicular phase and the oviducts were incubated in vitro with leptin, PGF2alpha, PGE2, NO donor and inhibitors of NOS and cyclo-oxigenase (COX). Using immunohistochemistry, Ob-R-like positive reaction was observed only in the cytoplasm of secretory cells, having stronger intensity in the infundibulum and ampulla tracts than in the isthmus. Both leptin and NO donor inhibited PGE2 release, whereas they enhanced PGF2alpha release; NOS inhibitor alone or with leptin increased PGE2 and decreased PGF2alpha production; NOS activity was enhanced by leptin, while PGs did not affect this enzyme. This study suggests that the oviduct could be a potential target for endocrine regulation by leptin, whose circulating levels may act as a metabolic signal modulating oviductal PG release through mediation of the NOS/NO system

Leptin receptor expression and in vitro leptin actions on prostaglandin release and nitric oxide synthase activity in the rabbit oviduct

In this study, we have examined the presence and the distribution of receptors for leptin (Ob-R) in the oviduct of rabbits, and the effects of leptin on the release of prostaglandin (PG) F2alpha and PGE2 and on the activity of nitric oxide (NO) synthase (NOS) by oviducts cultured in vitro. Rabbits were killed during the follicular phase and the oviducts were incubated in vitro with leptin, PGF2alpha, PGE2, NO donor and inhibitors of NOS and cyclo-oxigenase (COX). Using immunohistochemistry, Ob-R-like positive reaction was observed only in the cytoplasm of secretory cells, having stronger intensity in the infundibulum and ampulla tracts than in the isthmus. Both leptin and NO donor inhibited PGE2 release, whereas they enhanced PGF2alpha release; NOS inhibitor alone or with leptin increased PGE2 and decreased PGF2alpha production; NOS activity was enhanced by leptin, while PGs did not affect this enzyme. This study suggests that the oviduct could be a potential target for endocrine regulation by leptin, whose circulating levels may act as a metabolic signal modulating oviductal PG release through mediation of the NOS/NO system