277 research outputs found
Urophyseal control of plasma ionic concentration in Oreochromis mossambicus (Pisces) exposed to osmotic stress
Freshwater-and seawater-adapted Oreochromis mossambicus were submitted to 5 different treatments (urophysectomy, sham operation, urophyseal extract injection, saline injection and control) and transferred to brackish water. In freshwater – adapted fish transfarred to brackish water, urophysectomy increases plasma Na+, K+, Ca+ and osmotic concentrations. In seawater-adapted fish transferred to brackish water, plasma Na+ and K+ concentration were lower in control than other treatment group. The utophysis seems to act only in the “fine tuning” of osmoregulatory processes. Adaptations to changes in the salinity of the medium probably are regulated mainly by prolactin and cortisol.Exemplares de Oreochromis mossambicus adaptados à água doce e à água salgada foram submetidos a 5 tratamentos diferentes (urofisectomia, operação testemunho, injeção de extrato urofisário, injeção de salina e controle) e transferidos para água salobra. os peixes adaptados à água doce transferidos para água salobra a urofisectomia aumenta as concentrações de Na+, K+, Ca++ e osmótica do plasma. Em peixes adaptados à água salgada transferidos para água salobra as concentrações plasmáticas de Na+ e K+ são mais baixas no grupo controle do que nos outros grupos experimentais. A urófise parece atuar apenas no "ajuste fino" dos processos osmorregulatórios. A adaptação às mudanças de salinidade do meio provavelmente são reguladas principalmente pela prolactina e pelo cortisol
Biochemical parameters of silver catfish (Rhamdia quelen) after transport with eugenol or essential oil of Lippia alba added to the water
The transport of live fish is a routine practice in aquaculture and constitutes a considerable source of stress to the animals. The addition of anesthetic to the water used for fish transport can prevent or mitigate the deleterious effects of transport stress. This study investigated the effects of the addition of eugenol (EUG) (1.5 or 3.0 mu L L-1) and essential oil of Lippia alba (EOL) (10 or 20 mu L L-1) on metabolic parameters (glycogen, lactate and total protein levels) in liver and muscle, acetylcholinesterase activity (AChE) in muscle and brain, and the levels of protein carbonyl (PC), thiobarbituric acid reactive substances (TBARS) and nonprotein thiol groups (NPSH) and activity of glutathione-S-transferase in the liver of silver catfish (Rhamdia quelen; Quoy and Gaimard, 1824) transported for four hours in plastic bags (loading density of 169.2 g L-1). The addition of various concentrations of EUG (1.5 or 3.0 mu L L-1) and EOL (10 or 20 mu L L-1) to the transport water is advisable for the transportation of silver catfish, since both concentrations of these substances increased the levels of NPSH antioxidant and decreased the TBARS levels in the liver. In addition, the lower liver levels of glycogen and lactate in these groups and lower AChE activity in the brain (EOL 10 or 20 mu L L-1) compared to the control group indicate that the energetic metabolism and neurotransmission were lower after administration of anesthetics, contributing to the maintenance of homeostasis and sedation status.Fundacao de Amparo a Pesquisa do Estado do Rio Grande do Sul (FAPERGS/PRONEX) [10/0016-8]; Conselho Nacional de Pesquisa e Desenvolvimento Cientifico (CNPq) [470964/2009-0]; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES); CNPqinfo:eu-repo/semantics/publishedVersio
Transcultural adaptation to the Brazilian Portuguese of the Postpartum Bonding Questionnaire for assessing the postpartum bond between mother and baby
The establishment of the bond between mother and baby in the postpartum period is important for ensuring the physical and psychological health of both. This short communication reports the first phase of the cross-cultural translation and adaptation to the Brazilian context of the Postpartum Bonding Questionnaire (PBQ). Four aspects of equivalence between the original scale and the Portuguese version were evaluated: the conceptual, semantic, operational and item equivalences. Literature review, the study of PBQ history, translation, expert evaluation, back-translation and pretests involving 30 mothers with children aging up to 7 months using a primary healthcare unit were conducted. Each step demonstrated the need for adjustments, which were made during the adaptation process. At the end of the study, a version of PBQ in Brazilian Portuguese equivalent to the original one was obtained, offering promise for national studies on the mother-baby bond, and its influence on health, and for use in health services
In the lycophyte Selaginella martensii is the "extra-qT" related to energy spillover? Insights into photoprotection in ancestral vascular plants
Lycophytes are early diverging vascular plants, representing a minor
group as compared to the dominating euphyllophytes, mostly angiosperms.
Having maximally developed in a CO2-rich atmosphere, extant
lycophytes are characterized by a low carbon fixing capacity, which is
compensated by a marked ability to induce the non-photochemical
quenching of chlorophyll fluorescence (NPQ). Different kinetic
components contribute to NPQ, in particular the fast relaxing
high-energy quenching qE, the middle relaxing qT, and the slowly
relaxing qI. Unlike angiosperms, lycophytes enhance the qT component
under high light, originating from an "extra-qT". In this research, we
analyze whether in Selaginella martensii the extra-qT can reflect a
photosystem (PS) I-based quenching mechanism activated upon saturation
of qE capacity. From comparative analyses of fluorescence quenching
parameters, carbon fixation, in vivo low- and room-temperature
fluorescence spectroscopy, and thylakoid protein phosphorylation, it is
proposed that the extra-qT is not mechanistically separate from the
ordinary qT. The results suggest a relationship between qT and
photoprotective energy spillover to PSI, which is activated upon sensing
the excitation energy pressure inside PSII and is possibly facilitated
by phosphorylation of Lhcb6, a minor antenna protein of PSII. Energy
spillover emphasizes 77K fluorescence emission from PSI core (F714) and
becomes more relevant at irradiance levels corresponding to the CO2-limited,
potentially photoinhibiting phase of photosynthesis. At the highest
irradiances, when Lhcb6 phosphorylation potential has been saturated,
the major LHCII increases in turn its phosphorylation level, probably
leading to the full exploitation of PSI as a safe excitation sink. It is
suggested that the low photosynthetic capacity of lycophytes could
allow an easier experimental access to the use of PSI as a safe
excitation quencher for PSII, a debated, emerging issue about thylakoid
photoprotection in angiosperms.</p
Bone Mineral Density and Trabecular Bone Score Changes throughout Menopause in Women with HIV
Objective: The objectives of this study were to describe the trajectories of bone mineral density (BMD) and trabecular bone score (TBS) changes throughout pre-menopause (reproductive phase and menopausal transition) and post-menopause (early and late menopause) in women with HIV (WWH) undergoing different antiretroviral therapies (ARTs) and explore the risk factors associated with those changes. Methods: This was an observational longitudinal retrospective study in WWH with a minimum of two DEXA evaluations comprising BMD and TBS measurements, both in the pre-menopausal and post-menopausal periods. Menopause was determined according to the STRAW+10 criteria, comprising four periods: the reproductive period, menopausal transition, and early- and late-menopausal periods. Mixed-effects models were fitted to estimate the trajectories of the two outcomes (BMD and TBS) over time. Annualized lumbar BMD and TBS absolute and percentage changes were calculated in each STRAW+10 time window. A backward elimination procedure was applied to obtain the final model, including the predictors that affected the trajectories of BMD or TBS over time. Results: A total of 202 WWH, all Caucasian, were included. In detail, 1954 BMD and 195 TBS data were analyzed. The median number of DEXA evaluations per woman was 10 (IQR: 7, 12). The median observation periods per patient were 12.0 years (IQR = 8.9-14.4) for BMD and 6.0 years (IQR: 4.3, 7.9) for TBS. The prevalence of osteopenia (63% vs. 76%; p < 0.001) and osteoporosis (16% vs. 36%; p < 0.001) increased significantly between the pre-menopausal and post-menopausal periods. Both BMD (1.03 (+/- 0.14) vs. 0.92 (+/- 0.12) g/cm2; p < 0.001) and TBS (1.41 (IQR: 1.35, 1.45) vs. 1.32 (IQR: 1.28, 1.39); p < 0.001) decreased significantly between the two periods. The trend in BMD decreased across the four STRAW+10 periods, with a slight attenuation only in the late-menopausal period when compared with the other intervals. The TBS slope did not significantly change throughout menopause. The delta mean values of TBS in WWH were lower between the menopausal transition and reproductive period compared with the difference between menopause and menopausal transition. Conclusions: Both BMD and TBS significantly decreased over time. The slope of the change in BMD and TBS significantly decreased in the menopausal transition, suggesting that this period should be considered by clinicians as a key time during which to assess bone health and modifiable risk factors in WWH
Anesthesia of Epinephelus marginatus with essential oil of Aloysia polystachya: an approach on blood parameters
This study investigated the anesthetic potential of the essential oil (EO) of Aloysia polystachya in juveniles of dusky grouper (Epinephelus marginatus). Fish were exposed to different concentrations of EO of A. polystachya to evaluate time of induction and recovery from anesthesia. In the second experiment, fish were divided into four groups: control, ethanol and 50 or 300 mu L L-1 EO of A. polystachya, and each group was submitted to induction for 3.5 min and recovery for 5 or 10 min. The blood gases and glucose levels showed alterations as a function of the recovery times, but Na+ and K+ levels did not show any alteration. In conclusion, the EO from leaves of A. polystachya is an effective anesthetic for dusky grouper, because anesthesia was reached within the recommended time at EO concentrations of 300 and 400 mu L L-1. However, most evaluated blood parameters showed compensatory responses due to EO exposure.Fundacao de Amparo a Pesquisa do Estado do Rio Grande do Sul/Programa de Apoio a Nucleos de Excelencia (FAPERGS/PRONEX) [10/0016-8]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) [470964/2009-0]; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior, Brazil (CAPES)info:eu-repo/semantics/publishedVersio
Reactivity of Metal-Free and Metal-Associated Amyloid-?? with Glycosylated Polyphenols and Their Esterified Derivatives
Both amyloid-?? (A??) and transition metal ions are shown to be involved in the pathogenesis of Alzheimer???s disease (AD), though the importance of their interactions remains unclear. Multifunctional molecules, which can target metal-free and metal-bound A?? and modulate their reactivity (e.g., A?? aggregation), have been developed as chemical tools to investigate their function in AD pathology; however, these compounds generally lack specificity or have undesirable chemical and biological properties, reducing their functionality. We have evaluated whether multiple polyphenolic glycosides and their esterified derivatives can serve as specific, multifunctional probes to better understand AD. The ability of these compounds to interact with metal ions and metal-free/-associated A??, and further control both metal-free and metal-induced A?? aggregation was investigated through gel electrophoresis with Western blotting, transmission electron microscopy, UV-Vis spectroscopy, fluorescence spectroscopy, and NMR spectroscopy. We also examined the cytotoxicity of the compounds and their ability to mitigate the toxicity induced by both metal-free and metal-bound A??. Of the polyphenols investigated, the natural product (Verbascoside) and its esterified derivative (VPP) regulate the aggregation and cytotoxicity of metal-free and/or metal-associated A?? to different extents. Our studies indicate Verbascoside represents a promising structure for further multifunctional tool development against both metal-free A?? and metal-A??.open0
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