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1.
Proc Natl Acad Sci U S A ; 120(10): e2214035120, 2023 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-36848574

RESUMO

Assessing environmental changes in Southern Ocean ecosystems is difficult due to its remoteness and data sparsity. Monitoring marine predators that respond rapidly to environmental variation may enable us to track anthropogenic effects on ecosystems. Yet, many long-term datasets of marine predators are incomplete because they are spatially constrained and/or track ecosystems already modified by industrial fishing and whaling in the latter half of the 20th century. Here, we assess the contemporary offshore distribution of a wide-ranging marine predator, the southern right whale (SRW, Eubalaena australis), that forages on copepods and krill from ~30°S to the Antarctic ice edge (>60°S). We analyzed carbon and nitrogen isotope values of 1,002 skin samples from six genetically distinct SRW populations using a customized assignment approach that accounts for temporal and spatial variation in the Southern Ocean phytoplankton isoscape. Over the past three decades, SRWs increased their use of mid-latitude foraging grounds in the south Atlantic and southwest (SW) Indian oceans in the late austral summer and autumn and slightly increased their use of high-latitude (>60°S) foraging grounds in the SW Pacific, coincident with observed changes in prey distribution and abundance on a circumpolar scale. Comparing foraging assignments with whaling records since the 18th century showed remarkable stability in use of mid-latitude foraging areas. We attribute this consistency across four centuries to the physical stability of ocean fronts and resulting productivity in mid-latitude ecosystems of the Southern Ocean compared with polar regions that may be more influenced by recent climate change.


Assuntos
Mudança Climática , Ecossistema , Animais , Regiões Antárticas , Efeitos Antropogênicos , Oceano Índico
2.
J Hered ; 111(3): 263-276, 2020 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-32347944

RESUMO

As species recover from exploitation, continued assessments of connectivity and population structure are warranted to provide information for conservation and management. This is particularly true in species with high dispersal capacity, such as migratory whales, where patterns of connectivity could change rapidly. Here we build on a previous long-term, large-scale collaboration on southern right whales (Eubalaena australis) to combine new (nnew) and published (npub) mitochondrial (mtDNA) and microsatellite genetic data from all major wintering grounds and, uniquely, the South Georgia (Islas Georgias del Sur: SG) feeding grounds. Specifically, we include data from Argentina (npub mtDNA/microsatellite = 208/46), Brazil (nnew mtDNA/microsatellite = 50/50), South Africa (nnew mtDNA/microsatellite = 66/77, npub mtDNA/microsatellite = 350/47), Chile-Peru (nnew mtDNA/microsatellite = 1/1), the Indo-Pacific (npub mtDNA/microsatellite = 769/126), and SG (npub mtDNA/microsatellite = 8/0, nnew mtDNA/microsatellite = 3/11) to investigate the position of previously unstudied habitats in the migratory network: Brazil, SG, and Chile-Peru. These new genetic data show connectivity between Brazil and Argentina, exemplified by weak genetic differentiation and the movement of 1 genetically identified individual between the South American grounds. The single sample from Chile-Peru had an mtDNA haplotype previously only observed in the Indo-Pacific and had a nuclear genotype that appeared admixed between the Indo-Pacific and South Atlantic, based on genetic clustering and assignment algorithms. The SG samples were clearly South Atlantic and were more similar to the South American than the South African wintering grounds. This study highlights how international collaborations are critical to provide context for emerging or recovering regions, like the SG feeding ground, as well as those that remain critically endangered, such as Chile-Peru.


Assuntos
Variação Genética , Baleias/genética , Distribuição Animal , Migração Animal , Animais , Brasil , Chile , Comportamento Alimentar , Feminino , Técnicas de Genotipagem , Ilhas , Masculino , Peru
3.
J Physiol ; 596(7): 1167-1179, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29462837

RESUMO

KEY POINTS: Hypoxaemia evokes a repertoire of homeostatic adjustments that maintain oxygen supply to organs and tissues including the brain and skeletal muscles. Because hypertensive patients have impaired endothelial-dependent vasodilatation and an increased sympathetic response to arterial oxygen desaturation, we investigated whether hypertension impairs isocapnic hypoxia-induced cerebral and skeletal muscle hyperaemia to an extent that limits oxygen supply. In middle-aged hypertensive men, vertebral and femoral artery blood flow do not increase in response to isocapnic hypoxia, limiting brain and peripheral hyperaemia and oxygen supply. Increased chemoreflex-induced sympathetic activation impairs skeletal muscle perfusion and oxygen supply, whereas an attenuation of local vasodilatory signalling in the posterior cerebrovasculature reduced brain hyperperfusion of hypertensive middle-aged men in response to isocapnic hypoxia. ABSTRACT: The present study investigated whether hypertension impairs isocapnic hypoxia (IH)-induced cerebral and skeletal muscle hyperaemia to an extent that limits oxygen supply. Oxygen saturation (oxymetry), mean arterial pressure (photoplethysmography) and muscle sympathetic nerve activity (MSNA; microneugraphy), as well as femoral artery (FA), internal carotid artery and vertebral artery (VA) blood flow (BF; Doppler ultrasound), were quantified in nine normotensive (NT) (aged 40 ± 11 years, systolic pressure 119 ± 7 mmHg and diastolic pressure 73 ± 6 mmHg) and nine hypertensive men (HT) (aged 44 ± 12 years, systolic pressure 152 ± 11 mmHg and diastolic pressure 90 ± 9 mmHg) during 5 min of normoxia (21% O2 ) and IH (10% O2 ). Total cerebral blood flow (tCBF), brain (CDO2 ) and leg (LDO2 ) oxygen delivery were estimated. IH provoked similar oxygen desaturation without changing mean arterial pressure. Internal carotid artery perfusion increased in both groups during IH. However, VA and FA BF only increased in NT. Thus, IH-induced increase in tCBF was smaller in HT. CDO2 only increased in NT and LDO2 decreased in HT. Furthermore, IH evoked a greater increase in HT MSNA. Changes in MSNA were inversely related to FA BF, LDO2 and end-tidal oxygen tension. In conclusion, hypertension disturbs regional and total cerebrovascular and peripheral responses to IH and consequently limits oxygen supply to the brain and skeletal muscle. Although increased chemoreflex-induced sympathetic activation may explain impaired peripheral perfusion, attenuated vasodilatory signalling in the posterior cerebrovasculature appears to be responsible for the small increase in tCBF when HT were exposed to IH.


Assuntos
Circulação Cerebrovascular , Hipertensão/etiologia , Hipóxia/fisiopatologia , Oxigênio/administração & dosagem , Fluxo Sanguíneo Regional , Vasodilatação , Adulto , Estudos de Casos e Controles , Feminino , Artéria Femoral/fisiopatologia , Hemodinâmica , Humanos , Hipertensão/patologia , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Nervos Periféricos/fisiopatologia , Artéria Vertebral/fisiopatologia
4.
J Acoust Soc Am ; 140(3): 1850, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27914379

RESUMO

Aiming to gather information on southern right whale (Eubalaena australis) mother-calf pairs' vocal behavior, archival acoustic recorders were deployed at a calving area off Brazil. Manual inspection of spectrograms revealed seven call classes: upcall, downcall, down-upcall, tonal variable, tonal constant, hybrid, and pulsive calls, which are consistent with those previously described for this species in Argentina. Gunshots and warbles, vocalizations described from other right whale species, were not detected. Mean values of start, end, maximum, minimum and peak frequencies, frequency bandwidth and duration were calculated for each call class. Start and end frequencies, frequency bandwidth and duration of upcalls recorded off Brazil were compared to those from other right whale populations and species. Only mean duration of upcalls from Brazil were significantly different from upcalls from all other populations. Differences in call duration may be driven by differences in demographic factors or background noise features among study areas. The repertoire characterization presented in this study will contribute to increase the utility of passive acoustic monitoring as a tool for conservation and research of southern right whales off Brazil as it provides important baseline information on the vocal behavior of this species.


Assuntos
Baleias , Acústica , Animais , Brasil , Feminino , Mães , Ruído , Vocalização Animal
5.
Eur J Clin Microbiol Infect Dis ; 34(3): 593-600, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25359581

RESUMO

The epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in the community in Portugal is not completely understood. To evaluate S. aureus and MRSA carriage among the elderly, we conducted a large cross-sectional study between April 2010 and December 2012. A total of 3,361 adults over 60 years of age were screened for S. aureus nasopharyngeal and oropharyngeal carriage. MRSA were characterized by staphylococcal cassette chromosome mec (SCCmec) typing, spa typing, multilocus sequence typing (MLST), and tested for the presence of Panton-Valentine leukocidin (PVL). Risk factors for MRSA carriage were identified by multiple logistic regression analysis. The prevalence of S. aureus and MRSA carriage among the elderly was 20.1 % and 1.8 %, respectively. The risk of being an MRSA carrier was higher among the elderly living in retirement homes [odds ratio (OR) = 2.90, 95 % confidence interval (CI): 1.48-5.48] and those that had been hospitalized in the previous year (OR = 2.64, 95 % CI: 1.47-4.58). Among the 62 MRSA isolates, 64.5 % were multidrug-resistant and none carried PVL. Most MRSA (82.3 %) were related to three hospital-associated (HA-MRSA) clones disseminated in Portugal: ST105-II (New York/Japan clone; 43.5 %), ST5-IVc (Pediatric clone; 19.4 %), and ST22-IVh (EMRSA-15 clone; 19.4 %). The New York/Japan and Pediatric clones were significantly associated with carriers living in retirement homes, while the EMRSA-15 clone was associated with carriers that had been hospitalized. We conclude that the elderly population in Portugal is essentially free of MRSA. Given the current European societal challenges for a healthy active aging, these results are of importance to healthcare professionals and public authorities to decide on strategies to promote health in this age group.


Assuntos
Portador Sadio/epidemiologia , Portador Sadio/microbiologia , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Idoso , Idoso de 80 Anos ou mais , Toxinas Bacterianas/genética , Análise por Conglomerados , Estudos Transversais , Exotoxinas/genética , Genótipo , Humanos , Leucocidinas/genética , Masculino , Pessoa de Meia-Idade , Tipagem Molecular , Nasofaringe/microbiologia , Orofaringe/microbiologia , Portugal/epidemiologia , Prevalência , Fatores de Risco
6.
J Esthet Restor Dent ; 27 Suppl 1: S49-57, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25886091

RESUMO

PURPOSE: This study evaluated the applicability of 9,10-phenanthrenequinone (PQ) in experimental dental composites. MATERIALS: Camphorquinone (CQ), PQ, ethyl 4-N,N-dimethylaminobenzoate (EDMAB) and diphenyliodonium salt (DPI) were employed. A mixture of 2,2-bis(4-[2-hydroxy-3-methacryloxypropoxy]phenyl)-propane/triethylene glycol dimethacrylate (60:40%) and silanated glass filler at 60% were used. A two-peak-based light-emitting diode (LED) was used. METHODS: The photoinitiator absorption and the light emission spectra were determined by a Ultraviolet-visible spectroscopy and a spectroradiometer, respectively. Relative photon absorption (RPabs) was calculated. Fourier-transformed infrared spectroscopy analysis was used to determine the degree of conversion (DC). The optical properties were determined with a spectrophotometer. Depth of cure was assessed from adapted International Organization for Standardization (ISO) 4049. Results were analyzed with descriptive analysis, analysis of variance, and Tukey's test (α = 5%). RESULTS: PQ showed higher RPabs than CQ. Regarding the DC, CQ + EDMAB (control), CQ + EDMAB + DPI, PQ + DPI, and PQ + EDMAB + DPI produced statistically similar results. Groups formulated with CQ presented higher depth of cure. Only the group formulated with CQ + EDMAB presented satisfactory color stability (ΔE < 3.3). CONCLUSION: PQ presented higher RPabs than CQ and it was able to produce DC similar to CQ + EDMAB, when used with DPI. However, groups formulated with PQ produced lower depth of cure, greater yellowing, and less color stability than the traditional combination CQ and amine. CLINICAL SIGNIFICANCE: Although research with novel photoinitiator systems should be encouraged, the traditional camphorquinone and amine pair remains as a reliable combination for the formulation of dental composites.


Assuntos
Cor , Resinas Compostas , Fenantrenos/química , Quinonas/química , Terpenos/química , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Salud Publica Mex ; 56(2): 221-5, 2014 Apr.
Artigo em Espanhol | MEDLINE | ID: mdl-25014429

RESUMO

Health care is one of the major issues in social policy, affected by multiple factors, such as the increase in health costs, crisis, and the degree of private participation in the financing of services. In this essay we reflect on this participation of the private sector in health care, with Brazil as a reference country and taking into account member states of the Union of South American Nations. Based on a qualitative study using data from national and international organizations, we found significant private participation in health care of countries in various continents, with an increase of public and private spending between 2000 and 2010. Regardless of the adopted health system, there was an increase of private spending in most countries analyzed, which emphasizes the need to further evaluate the performance of public and private sectors, as well as the regulatory frameworks for their participation in health care, thus enabling policies that promote quality improvement and the expansion of coverage.


Assuntos
Atenção à Saúde/organização & administração , Setor Privado , Setor Público , Brasil
8.
Clin Exp Pharmacol Physiol ; 39(12): 1034-7, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23734984

RESUMO

There is increasing evidence suggesting involvement of the renin-angiotensin system (RAS) in carbohydrate metabolism and its response to stress. Thus, the aim of the present study was to evaluate the effects of chronic inhibition of the RAS on glucose and insulin levels during acute restraint stress. Male Holtzman rats were treated with 10 mg/kg per day enalapril solution or vehicle for 14 days. After 14 days, rats were divided into three experimental groups: enalapril + restraint (ER), vehicle + restraint (VR) and enalapril + saline (ES). Rats in the restraint groups were subjected to 30 min restraint stress, whereas rats in the ES groups were given saline infusion instead. Blood samples were collected at baseline and after 5, 10, 20 and 30 min restraint stress or saline infusion. After restraint, a hyperglycaemic response was observed in the ER and VR groups that peaked at 20 and 10 min, respectively (P < 0.05 compared with baseline). The area under the glucose curve was markedly increased in the ER and VR groups compared with that in the ES group (P < 0.05 for both). Importantly, restraint induced a marked increase in insulin secretion in the ER group compared with only a mild elevation in the VR group; insulin secretion in both groups peaked at 20 min (P < 0.05 compared with baseline). Analysis of the area under the insulin curve confirmed an increase in insulin secretion in the ER compared with the VR and ES groups (P < 0.05 for both). The results of the present study reinforce that the RAS is involved in modulating responses to stress and suggest that RAS inhibition with enalapril may increase glucose-induced insulin secretion in response to acute restraint.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Enalapril/farmacologia , Glucose/metabolismo , Insulina/metabolismo , Sistema Renina-Angiotensina/efeitos dos fármacos , Estresse Psicológico/metabolismo , Animais , Glicemia/análise , Insulina/sangue , Secreção de Insulina , Masculino , Ratos , Ratos Sprague-Dawley , Sistema Renina-Angiotensina/fisiologia , Restrição Física , Estresse Psicológico/sangue , Estresse Psicológico/fisiopatologia , Fatores de Tempo
9.
Int J Sports Med ; 33(12): 970-4, 2012 12.
Artigo em Inglês | MEDLINE | ID: mdl-22895875

RESUMO

This study performed an exploratory analysis of the anthropometrical and morphological muscle variables related to the one-repetition maximum (1RM) performance. In addition, the capacity of these variables to predict the force production was analyzed. 50 active males were submitted to the experimental procedures: vastus lateralis muscle biopsy, quadriceps magnetic resonance imaging, body mass assessment and 1RM test in the leg-press exercise. K-means cluster analysis was performed after obtaining the body mass, sum of the left and right quadriceps muscle cross-sectional area (∑CSA), percentage of the type II fibers and the 1RM performance. The number of clusters was defined a priori and then were labeled as high strength performance (HSP1RM) group and low strength performance (LSP1RM) group. Stepwise multiple regressions were performed by means of body mass, ∑CSA, percentage of the type II fibers and clusters as predictors' variables and 1RM performance as response variable. The clusters mean ± SD were: 292.8 ± 52.1 kg, 84.7 ± 17.9 kg, 19249.7 ± 1645.5 mm(2) and 50.8 ± 7.2% for the HSP1RM and 254.0 ± 51.1 kg, 69.2 ± 8.1 kg, 15483.1 ± 1104.8mm(2) and 51.7 ± 6.2%, for the LSP1RM in the 1RM, body mass, ∑CSA and muscle fiber type II percentage, respectively. The most important variable in the clusters division was the ∑CSA. In addition, the ∑CSA and muscle fiber type II percentage explained the variance in the 1RM performance (Adj R2=0.35, p=0.0001) for all participants and for the LSP1RM (Adj R2=0.25, p=0.002). For the HSP1RM, only the ∑CSA was entered in the model and showed the highest capacity to explain the variance in the 1RM performance (Adj R2=0.38, p=0.01). As a conclusion, the muscle CSA was the most relevant variable to predict force production in individuals with no strength training background.


Assuntos
Desempenho Atlético/fisiologia , Força Muscular/fisiologia , Adolescente , Humanos , Masculino , Análise Multivariada , Adulto Jovem
10.
Sci Rep ; 10(1): 20008, 2020 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-33203946

RESUMO

We present estimates of the seasonal and spatial occupation by pinnipeds of the Wildlife Refuge of Ilha dos Lobos (WRIL), based on aerial photographic censuses. Twenty aerial photographic censuses were analysed between July 2010 and November 2018. To assess monthly differences in the numbers of pinnipeds in the WRIL we used a Generalized Linear Mixed Model. Spatial analysis was carried out using Kernel density analysis of the pinnipeds on a grid plotted along the WRIL. Subadult male South American sea lions (Otaria flavescens) were the most abundant pinniped in the WRIL. Potential females of this species were also recorded during half of the census. The maximum number of pinnipeds observed in the WRIL was 304 in September 2018, including an unexpected individual southern elephant seal (Mirounga leonina), and a high number of South American fur seal yearlings (Arctocephalus australis). However, there was no statistically significant difference in counts between months. In all months analysed, pinnipeds were most often found concentrated in the northern portion of the island, with the highest abundances reported in September. This study confirms the importance of the WRIL as a haulout site for pinnipeds in Brazil, recommends that land research and recreational activities occur in months when no pinnipeds are present, and encourages a regulated marine mammal-based tourism during winter and spring months.


Assuntos
Otárias/fisiologia , Leões-Marinhos/fisiologia , Animais , Brasil , Caniformia/fisiologia , Feminino , Masculino , Focas Verdadeiras/fisiologia , Estações do Ano
11.
Arch Endocrinol Metab ; 62(2): 236-263, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29768629

RESUMO

Prolactinomas are the most common pituitary adenomas (approximately 40% of cases), and they represent an important cause of hypogonadism and infertility in both sexes. The magnitude of prolactin (PRL) elevation can be useful in determining the etiology of hyperprolactinemia. Indeed, PRL levels > 250 ng/mL are highly suggestive of the presence of a prolactinoma. In contrast, most patients with stalk dysfunction, drug-induced hyperprolactinemia or systemic diseases present with PRL levels < 100 ng/mL. However, exceptions to these rules are not rare. On the other hand, among patients with macroprolactinomas (MACs), artificially low PRL levels may result from the so-called "hook effect". Patients harboring cystic MACs may also present with a mild PRL elevation. The screening for macroprolactin is mostly indicated for asymptomatic patients and those with apparent idiopathic hyperprolactinemia. Dopamine agonists (DAs) are the treatment of choice for prolactinomas, particularly cabergoline, which is more effective and better tolerated than bromocriptine. After 2 years of successful treatment, DA withdrawal should be considered in all cases of microprolactinomas and in selected cases of MACs. In this publication, the goal of the Neuroendocrinology Department of the Brazilian Society of Endocrinology and Metabolism (SBEM) is to provide a review of the diagnosis and treatment of hyperprolactinemia and prolactinomas, emphasizing controversial issues regarding these topics. This review is based on data published in the literature and the authors' experience.


Assuntos
Hiperprolactinemia/diagnóstico , Hiperprolactinemia/terapia , Neoplasias Hipofisárias/diagnóstico , Neoplasias Hipofisárias/terapia , Guias de Prática Clínica como Assunto , Prolactinoma/diagnóstico , Prolactinoma/terapia , Antineoplásicos/uso terapêutico , Brasil , Bromocriptina/uso terapêutico , Cabergolina , Agonistas de Dopamina/uso terapêutico , Ergolinas/uso terapêutico , Feminino , Humanos , Masculino , Prolactina/sangue
12.
Arq Bras Endocrinol Metabol ; 51(6): 1018-22, 2007 Aug.
Artigo em Português | MEDLINE | ID: mdl-17934672

RESUMO

The histiocytoses are rare diseases caused by alterations in the monocyte-histiocytic series with several clinical findings. Among the cutaneous syndromes of non-Langerhans cells, xanthoma disseminatum is the only disease of this group that has been classically associated to the central diabetes insipidus (CDI). The case reported describes a 30-year-old man that two years after presenting with CDI developed non confluent disseminated cutaneous brown papular lesions throughout the body. The histopathology, immunohistochemistry, and electronic microscopy were compatible with the diagnosis of non-Langerhans histiocytoses, suggesting the diagnosis of juvenile xanthogranuloma. The endocrine-metabolic evaluation did not show other alterations besides CDI in a 10-year follow up. The magnetic resonance of hypophysis showed absence of the pituitary hyperintense sign (bright spot). The radiologic and scinthigraphic evaluation of the bones did not show the presence of osteolytic lesions. This case prints out the importance of skin examination in cases of CDI and its association with cutaneous non-Langerhans histiocytoses in a broader spectrum, rather then restricted to the cases of xanthoma disseminatum.


Assuntos
Diabetes Insípido Neurogênico/etiologia , Histiocitose de Células de Langerhans/complicações , Adulto , Diabetes Insípido Neurogênico/patologia , Diagnóstico Diferencial , Histiocitose de Células de Langerhans/patologia , Humanos , Masculino , Microscopia Eletrônica , Xantogranuloma Juvenil/complicações , Xantogranuloma Juvenil/patologia
13.
Dent Mater ; 33(4): 394-401, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28245929

RESUMO

OBJECTIVE: This study has investigated the influence of BisGMA, BisEMA, BisEMA 30, and two UDMA-based monomers (UDMA and Fit 852), with TEGDMA as co-monomer, on the degree of conversion, water sorption, water solubility, and optical properties of experimental dental composites. METHODS: Materials were formulated at 70/30 molar rations using BisGMA, BisEMA, BisEMA 30, UDMA or FIT 852, as base monomers, combined with TEGDMA. 60wt% of silanated-glass particles was added. Degree of conversion (DC) and polymerization kinetics were monitored using Fourier-transformed infrared spectroscopy in the near-IR range. Water sorption (Wsp) and solubility (Wsl) were assessed using mass variation after 60days water storage. Color was evaluated using a digital spectrophotometer, applying the CIELab parameters 24h after dry storage and 60days after water immersion to calculate ΔE values. All data were analyzed using ANOVA and Tukey's test (pre-set alpha=0.05). RESULTS: The BisGMA-based co-monomer mixture presented the lowest DC (62±1%), whereas BisEMA 30 had the highest DC value (95±2%). The highest Wsp was observed for BisEMA 30 (12.2±0.8%), and the lowest for BisEMA (0.4±0.1%). BisEMA has shown the lowest Wsl (0.03±0.01%) and BisEMA 30 the highest one (0.97±0.1%). The ΔE values showed that BisEMA 30 (7.3 color units) and Fit 852 (3.8 color units) altered the color stability providing ΔE>3.3, which is considered clinically unacceptable. CONCLUSIONS: The chemical composition and structure of the base monomer influenced the degree of conversion, water sorption, water solubility, and color stability. Considering the overall results, it is possible to state that the base monomer BisEMA mixed with the co-monomer TEGDMA presented the best performance in terms of all the parameters tested. SIGNIFICANCE: The resin matrix composition might influence physical property degradation processes and color stability of dental resin composites. Formulations based on BisEMA seem most promising for materials' development.


Assuntos
Resinas Compostas , Materiais Dentários , Teste de Materiais , Metacrilatos , Polimerização , Solubilidade , Água
14.
Phytochemistry ; 139: 60-71, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28414935

RESUMO

The genus Swartzia is a member of the tribe Swartzieae, whose genera constitute the living descendants of one of the early branches of the papilionoid legumes. Legume lectins comprise one of the main families of structurally and evolutionarily related carbohydrate-binding proteins of plant origin. However, these proteins have been poorly investigated in Swartzia and to date, only the lectin from S. laevicarpa seeds (SLL) has been purified. Moreover, no sequence information is known from lectins of any member of the tribe Swartzieae. In the present study, partial cDNA sequences encoding L-type lectins were obtained from developing seeds of S. simplex var. grandiflora. The amino acid sequences of the S. simplex grandiflora lectins (SSGLs) were only averagely related to the known primary structures of legume lectins, with sequence identities not greater than 50-52%. The SSGL sequences were more related to amino acid sequences of papilionoid lectins from members of the tribes Sophoreae and Dalbergieae and from the Cladratis and Vataireoid clades, which constitute with other taxa, the first branching lineages of the subfamily Papilionoideae. The three-dimensional structures of 2 representative SSGLs (SSGL-A and SSGL-E) were predicted by homology modeling using templates that exhibit the characteristic ß-sandwich fold of the L-type lectins. Molecular docking calculations predicted that SSGL-A is able to interact with D-galactose, N-acetyl-D-galactosamine and α-lactose, whereas SSGL-E is probably a non-functional lectin due to 2 mutations in the carbohydrate-binding site. Using molecular dynamics simulations followed by density functional theory calculations, the binding free energies of the interaction of SSGL-A with GalNAc and α-lactose were estimated as -31.7 and -47.5 kcal/mol, respectively. These findings gave insights about the carbohydrate-binding specificity of SLL, which binds to immobilized lactose but is not retained in a matrix containing D-GalNAc as ligand.


Assuntos
DNA Complementar/genética , Fabaceae/genética , Lectinas Tipo C/genética , Lectinas de Plantas/genética , Sequência de Aminoácidos , Carboidratos/análise , Fabaceae/química , Galactose/metabolismo , Humanos , Modelos Moleculares , Simulação de Acoplamento Molecular , Dados de Sequência Molecular , Grupos Populacionais , Sementes/química
15.
Ecol Evol ; 7(21): 9131-9143, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29177038

RESUMO

Due to their worldwide distribution and occupancy of different types of environments, bottlenose dolphins display considerable morphological variation. Despite limited understanding about the taxonomic identity of such forms and connectivity among them at global scale, coastal (or inshore) and offshore (or oceanic) ecotypes have been widely recognized in several ocean regions. In the Southwest Atlantic Ocean (SWA), however, there are scarce records of bottlenose dolphins differing in external morphology according to habitat preferences that resemble the coastal-offshore pattern observed elsewhere. The main aim of this study was to analyze the genetic variability, and test for population structure between coastal (n = 127) and offshore (n = 45) bottlenose dolphins sampled in the SWA to assess whether their external morphological distinction is consistent with genetic differentiation. We used a combination of mtDNA control region sequences and microsatellite genotypes to infer population structure and levels of genetic diversity. Our results from both molecular marker types were congruent and revealed strong levels of structuring (microsatellites FST = 0.385, p < .001; mtDNA FST =  0.183, p < .001; ΦST = 0.385, p < .001) and much lower genetic diversity in the coastal than the offshore ecotype, supporting patterns found in previous studies elsewhere. Despite the opportunity for gene flow in potential "contact zones", we found minimal current and historical connectivity between ecotypes, suggesting they are following discrete evolutionary trajectories. Based on our molecular findings, which seem to be consistent with morphological differentiations recently described for bottlenose dolphins in our study area, we recommend recognizing the offshore bottlenose dolphin ecotype as an additional Evolutionarily Significant Unit (ESU) in the SWA. Implications of these results for the conservation of bottlenose dolphins in SWA are also discussed.

16.
Sci Rep ; 6: 28205, 2016 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-27306583

RESUMO

The reproductive success of southern right whale (Eubalaena australis) depends on body condition and, therefore, on foraging success. This, in turn, might be affected by climatically driven change in the abundance of the species main prey, krill (Euphausia superba), on the feeding grounds. Annual data on southern right whale number of calves were obtained from aerial surveys carried out between 1997 and 2013 in southern Brazil, where the species concentrate during their breeding season. The number of calves recorded each year varied from 7 to 43 ( = 21.11 ± 11.88). Using cross-correlation analysis we examined the response of the species to climate anomalies and krill densities. Significant correlations were found with krill densities (r = 0.69, p = 0.002, lag 0 years), Oceanic Niño Index (r = -0.65, p = 0.03, lag 6 years), Antarctic Oscillation (r = 0.76, p = 0.01, lag 7 years) and Antarctic sea ice area (r = -0.68, p = 0.002, lag 0 years). Our results suggest that global climate indices influence southern right whale breeding success in southern Brazil by determining variation in food (krill) availability for the species. Therefore, increased frequency of years with reduced krill abundance, due to global warming, is likely to reduce the current rate of recovery of southern right whales from historical overexploitation.


Assuntos
Mudança Climática , Euphausiacea/metabolismo , Cadeia Alimentar , Dinâmica Populacional , Comportamento Sexual Animal/fisiologia , Baleias/fisiologia , Animais , Regiões Antárticas , Clima , Reprodução
17.
Mol Cell Endocrinol ; 240(1-2): 82-93, 2005 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-16024167

RESUMO

The GLUT4 gene transcriptional activity has a profound impact on the insulin-mediated glucose disposal and it is, therefore, important to understand the mechanisms underlying it. Insulin and exercise modulate GLUT4 expression in vivo, but the net control and involved mechanisms of each one have not been established yet. This paper sought to discriminate, in soleus muscle, the effects of insulin and muscle contraction on GLUT4 gene expression, and the involvement of transcriptional factors: myocite enhancer factor 2 (MEF2 A/C/D), hypoxia inducible factor 1-a (HIF1-a) and nuclear factor-kappa B (NF-kappaB). The GLUT4 mRNA was reduced by fasting (40%), and increased by in vitro incubation with insulin (25%) or insulin plus glucose (40%), which was accompanied by opposite regulations of NF-kappaB mRNA. Differently, in vitro, muscle contraction led to a rapid increase (35-80%) in GLUT4, MEF2A, MEF2D and HIF1-a mRNAs. Additionally, electrophoretic mobility shift assay confirmed changes in the binding activity of nuclear proteins to consensus NF-kappaB, GLUT4-Ebox and GLUT4-AT-rich element probes, parallel to the mRNA changes of their respective transcriptional factors NF-kappaB, HIF1-a and MEF2s. Concluding, insulin- and contraction-induced regulation of GLUT4 expression involves distinct transcriptional factors.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica , Insulina/fisiologia , Contração Muscular , Músculo Esquelético/fisiologia , Fatores de Transcrição/metabolismo , Animais , Proteínas de Ligação a DNA/genética , Jejum , Expressão Gênica/efeitos dos fármacos , Insulina/farmacologia , Fatores de Transcrição MEF2 , Masculino , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Fatores de Regulação Miogênica/genética , Fatores de Regulação Miogênica/metabolismo , NF-kappa B/genética , NF-kappa B/metabolismo , Proteínas Nucleares/metabolismo , RNA Mensageiro/análise , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Fatores de Transcrição/genética
18.
PLoS One ; 9(3): e90489, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24598539

RESUMO

From the early 17th century to the 1970s southern right whales, Eubalaena australis, were subject to intense exploitation along the Atlantic coast of South America. Catches along this coast recorded by whalers originally formed a continuum from Brazil to Tierra del Fuego. Nevertheless, the recovery of the population has apparently occurred fragmentarily, and with two main areas of concentration, one off southern Brazil (Santa Catarina) and another off central Argentina (Peninsula Valdés). This pattern suggests some level of heterogeneity amongst the population, which is apparently contradicted by records that traced individuals moving throughout the whole geographical extension covered by the species in the Southwest Atlantic. To test the hypothesis of the potential occurrence of discrete subpopulations exploiting specific habitats, we investigated N, C and O isotopic values in 125 bone samples obtained from whaling factories operating in the early 1970s in southern Brazil (n=72) and from contemporary and more recent strandings occurring in central Argentina (n=53). Results indicated significant differences between the two sampling areas, being δ13C and δ18O values significantly higher in samples from southern Brazil than in those from central Argentina. This variation was consistent with isotopic baselines from the two areas, indicating the occurrence of some level of structure in the Southwest Atlantic right whale population and equally that whales more likely feed in areas commonly thought to exclusively serve as nursing grounds. Results aim at reconsidering of the units currently used in the management of the southern right whale in the Southwest Atlantic Ocean. In the context of the current die-off affecting the species in Peninsula Valdés, these results also highlight the necessity to better understand movements of individuals and precisely identify their feeding areas.


Assuntos
Baleias/metabolismo , Animais , Argentina , Oceano Atlântico , Osso e Ossos/metabolismo , Brasil , Isótopos de Carbono/metabolismo , Isótopos de Nitrogênio/metabolismo , Isótopos de Oxigênio/metabolismo , Dinâmica Populacional
19.
Dent Mater ; 30(10): e264-71, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24985934

RESUMO

OBJECTIVE: To establish the relationship between photoinitiator system and nanofiller size on the optical properties and cure efficiency of model composites. METHODS: Model composites based on BisGMA/TEGDMA (60:40mol%) were loaded with 40wt% of 7nm or 16nm-sized filler particles. One of the following photoinitiator systems was added: camphorquinone (CQ) associated with an amine (EDMAB), monoacylphosphine oxide (TPO), or bysacylphosphine oxide (BAPO). The optical properties of disk-shaped specimens were measured 24h after curing and repeated after storage in water for 90 days and coffee for 15 days. A large spectrum LED unit (Bluephase G2, Ivoclar Vivadent) was used for photoactivation. CIE L*a*b* parameters, color difference (ΔE), and translucency parameter (TP) were calculated. Knoop hardness readings were taken at top and bottom composite surfaces. Cure efficiency was determined by bottom/top hardness ratio. Data were statistically analyzed at α=0.05 significance level. RESULTS: Composites formulated with 16nm particles had higher CIE L* than those with 7nm particles in all storage conditions. BAPO-based composites generally had lower CIE a* than the other composites. The group TPO+16nm before storage and all groups with 16nm-sized particles after storage had lower CIE b* (i.e. lower degree of yellowing) than the other groups. TPO-based materials had higher color stability. The cure efficiency was not significantly affected by photoinitiator system or particle size. CQ+7nm had the lowest and BAPO+16nm the highest hardness values. SIGNIFICANCE: Combination of photoinitiator system and filler particle size might affect the optical properties of composites, with low influence on cure efficiency.


Assuntos
Resinas Compostas , Lâmpadas de Polimerização Dentária , Nanotecnologia , Cor
20.
J Dent ; 41 Suppl 3: e67-72, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23228497

RESUMO

OBJECTIVES: The aim of this study was to formulate materials with high color stability and reduced degradation by using photoinitiator systems derived from phosphine oxides alternative to the traditional camphorquinone (CQ)/amine system. METHODS: Materials were formulated with the monomers BisGMA and TEGDMA as organic matrix. The photoinitiators tested were CQ+amine (EDMAB), phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO), BAPO+EDMAB, diphenyl(2,4,6-trimethylbenzoyl)-phosphine oxide (TPO) and TPO+EDMAB. A 60% mass of silanated glass filler particles was added. Degree of CC conversion was evaluated by Fourier-transformed infrared spectroscopy 10min after photopolymerization. The color properties were evaluated by a digital spectrophotometer, applying the CIELab parameters, either before photoactivation, immediately after photoactivation, 24h after dry storage, and one month after water immersion. Water sorption and solubility were assessed by mass gain or loss after storage in water for 30 days. Data were analyzed using ANOVA and Tukey's test (5%). RESULTS: Degree of conversion did not differ statistically among all the tested formulations. Regarding color, only groups with TPO presented satisfactory color stability after one month of water storage (ΔE<3.3). Water sorption and water stability did not differ among the groups. CONCLUSIONS: Degree of conversion, water sorption and water solubility did not differ among all the tested groups. The TPO-based groups were the only materials with satisfactory color stability after one month of water storage. CLINICAL SIGNIFICANCE: The use of a photoinitiator system containing TPO might improve the color stability of resin composites compared with the traditional CQ/amine system while attaining similar physico-chemical properties for the composite.


Assuntos
Resinas Compostas/química , Materiais Dentários/química , Fotoiniciadores Dentários/química , Absorção , Adsorção , Bis-Fenol A-Glicidil Metacrilato/química , Cânfora/análogos & derivados , Cânfora/química , Carbono/química , Cor , Imersão , Fosfinas/química , Polietilenoglicóis/química , Polimerização , Ácidos Polimetacrílicos/química , Solubilidade , Espectrofotometria/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Temperatura , Fatores de Tempo , Água/química , para-Aminobenzoatos/química
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