97 research outputs found
The relationship between obesity and quality of life in Brazilian adults
The incidence of obesity has reached epidemic proportions, affecting 30% of the adult population globally. During the last decade, the rising rates of obesity in developing countries has been particularly striking. One potential consequence of obesity is a decline in quality of life. Thus, the objective of the present study was to investigate the possible relationship between obesity, defined by body mass index (BMI), and quality of life, evaluated using the short version of the World Health Organization Quality of Life (WHOQOL) scale in a Brazilian population. The sample consisted of 30 men and 30 women, divided into three groups according to BMI: normal weight, obese, and morbidly obese. All of the subjects responded to the WHOQOL inventories. The results indicated that the groups with lower BMIs had better quality of life than the groups with higher BMIs. Being overweight interfered with quality of life equally in both sexes, with no difference found between men and women. The results indicate the necessity of multidisciplinary care of obese individuals
Distinct Contributions of Median Raphe Nucleus to Contextual Fear Conditioning and Fear-Potentiated Startle
Ascending 5-HT projections from the
median raphe nucleus (MRN), probably to the
hippocampus, are implicated in the acquisition
of contextual fear (background stimuli), as
assessed by freezing behavior. Foreground cues
like light, used as a conditioned stimulus (CS) in
classical fear conditioning, also cause freezing
through thalamic transmission to the amygdala.
As the MRN projects to the hippocampus and
amygdala, the role of this raphe nucleus in fear
conditioning to explicit cues remains to be
explained. Here we analyzed the behavior of
rats with MRN electrolytic lesions in a
contextual conditioning situation and in a fear-potentiated
startle procedure. The animals
received MRN electrolytic lesions either before
or on the day after two consecutive training
sessions in which they were submitted to 10
conditioning trials, each in an experimental
chamber (same context) where they. received
foot-shocks (0.6 mA, 1 sec) paired to a 4-sec
light CS. Seven to ten days later, the animals
were submitted to testing sessions for assessing
conditioned fear when they were placed for five
shocks, and the duration of contextual freezing
was recorded. The animals were then submitted
to a fear-potentiated startle in response to a 4-sec
light-CS, followed by white noise (100 dB, 50 ms). Control rats (sham) tested in the same
context showed more freezing than did rats
with pre- or post-training MRN lesions. Startle
was clearly potentiated in the presence of light CS in the sham-lesioned animals. Whereas pretraining
lesions reduced both freezing and fear-potentiated
startle, the post-training lesions
reduced only freezing to context, without
changing the fear-potentiated startle. In a
second experiment, neurotoxic lesions of the
MRN with local injections of N-methyl-D-aspartate
or the activation of 5-HT1A somatodendritic
auto-receptors of the MRN by
microinjections of the 5-HT1A receptor agonist
8-hydroxy- 2-(di-n-propylamino)tetralin (8-OH-DPAT)
before the training sessions also reduced
the amount of freezing and the fear-potentiated
startle. Freezing is a prominent response of
contextual fear conditioning, but does not seem
to be crucial for the enhancement of the startle
reflex by explicit aversive cues. As fear-potentiated
startle may be produced in posttraining
lesioned rats that are unable to freeze
to fear contextual stimuli, dissociable systems
seem to be recruited in each condition. Thus,
contextual fear and fear-potentiated startle are
conveyed by distinct 5-HT-mediated circuits of
the MRN
\u3ci\u3eIn Situ\u3c/i\u3e Cardiac Performance of Pacific Bluefin Tuna Hearts in Response to Acute Temperature Change
This study reports the cardiovascular physiology of the Pacific bluefin tuna (Thunnus orientalis) in an in situ heart preparation. The performance of the Pacific bluefin tuna heart was examined at temperatures from 30°C down to 2°C. Heart rates ranged from 156 beats min–1 at 30°C to 13 beats min–1 at 2°C. Maximal stroke volumes were 1.1 ml kg–1 at 25°C and 1.3 ml kg–1 at 2°C. Maximal cardiac outputs were 18.1 ml kg–1 min–1 at 2°C and 106 ml kg–1 min–1 at 25°C. These data indicate that cardiovascular function in the Pacific bluefin tuna exhibits a strong temperature dependence, but cardiac function is retained at temperatures colder than those tolerated by tropical tunas. The Pacific bluefin tuna\u27s cardiac performance in the cold may be a key adaptation supporting the broad thermal niche of the bluefin tuna group in the wild. In situ data from Pacific bluefin are compared to in situ measurements of cardiac performance in yellowfin tuna and preliminary results from albacore tuna
Polycomb recruitment attenuates retinoic acid-induced transcription of the bivalent NR2F1 gene
Polycomb proteins play key roles in mediating epigenetic modifications that occur during cell differentiation. The Polycomb repressive complex 2 (PRC2) mediates the tri-methylation of histone H3 lysine 27 (H3K27me3). In this study, we identify a distinguishing feature of two classes of PRC2 target genes, represented by the Nr2F1 (Coup-TF1) and the Hoxa5 gene, respectively. Both genes are transcriptionally activated by all-trans retinoic acid (RA) and display increased levels of the permissive H3K9/K14ac and tri-methylated histone H3 lysine 4 epigenetic marks in response to RA. However, while in response to RA the PRC2 and H3K27me3 marks are greatly decreased at the Hoxa5 promoter, these marks are initially increased at the Nr2F1 promoter. Functional depletion of the essential PRC2 protein Suz12 by short hairpin RNA (shRNA) technology enhanced the RA-associated transcription of Nr2F1, Nr2F2, Meis1, Sox9 and BMP2, but had no effect on the Hoxa5, Hoxa1, Cyp26a1, Cyp26b1 and RARβ2 transcript levels in wild-type embryonic stem cells. We propose that PRC2 recruitment attenuates the RA-associated transcriptional activation of a subset of genes. Such a mechanism would permit the fine-tuning of transcriptional networks during differentiation
Bioanalysis for Cocaine, Opiates, Methadone and Amphetamines Exposure Detection during Pregnancy
Drug exposure during pregnancy constitutes a major legal issue and public health concern. Drug and metabolite determination in biological matrices from mother and newborn is an objective indication of prenatal drug exposure. However, limited data are available regarding the interpretation of these analytical results in terms of window of detection and degree of exposure. We collected paired maternal hair, meconium, placenta and umbilical cord from 727 mother-newborn dyads. We analyzed these specimens by liquid chromatography tandem mass spectrometry for the determination of cocaine, opioids, methadone and amphetamines, and compared the analytical results from the four different matrices. The cases were divided in non-exposure, low and frequent exposure, based on maternal hair concentrations and segmental analysis by trimesters. For cocaine, 64 cases tested positive in hair, 9 in meconium, 6 in placenta and 7 in umbilical cord. In the case of opioids, 14 maternal hair cases were positive, 11 meconium and umbilical cord and 9 placenta samples. For methadone, 11 cases were positive in hair, 9 in meconium and 6 in placenta and umbilical cord. For amphetamines, 18 cases were positive according to maternal hair, but all meconium, placenta and umbilical cord tested negative. Maternal hair was the most sensitive specimen to detect drug exposure during pregnancy. Meconium, placenta and umbilical cord tested positive if hair concentrations showed frequent drug use during the whole pregnancy, especially during the third trimester. Meconium, placenta and umbilical cord also tested positive for morphine and metabolites, if this drug was administered during labor and delivery
Reproductive Schedules in Southern Bluefin Tuna: Are Current Assumptions Appropriate?
Southern bluefin tuna (SBT) appear to comprise a single stock that is assumed to be both mixed across its distribution and having reproductive adults that are obligate, annual spawners. The putative annual migration cycle of mature SBT consists of dispersed foraging at temperate latitudes with migration to a single spawning ground in the tropical eastern Indian Ocean. Spawning migrations have been assumed to target two peaks in spawning activity; one in September-October and a second in February-March. SBT of sizes comparable to that of individuals observed on the spawning ground were satellite tagged in the Tasman Sea region (2003–2008) and demonstrated both migrations to the spawning grounds and residency in the Tasman Sea region throughout the whole year. All individuals undertaking apparent spawning migrations timed their movements to coincide with the second recognised spawning peak or even later. These observations suggest that SBT may demonstrate substantial flexibility in the scheduling of reproductive events and may even not spawn annually as currently assumed. Further, the population on the spawning grounds may be temporally structured in association with foraging regions. These findings provide new perspectives on bluefin population and spatial dynamics and warrant further investigation and consideration of reproductive schedules in this species
Involvement in surface antigen expression by a moonlighting FG-repeat nucleoporin in trypanosomes
Components of the nuclear periphery coordinate a multitude of activities, including macromolecular transport, cell-cycle progression, and chromatin organization. Nuclear pore complexes (NPCs) mediate nucleocytoplasmic transport, mRNA processing, and transcriptional regulation, and NPC components can define regions of high transcriptional activity in some organisms at the nuclear periphery and nucleoplasm. Lineage-specific features underpin several core nuclear functions and in trypanosomatids, which branched very early from other eukaryotes, unique protein components constitute the lamina, kinetochores, and parts of the NPCs. Here we describe a phenylalanine-glycine (FG)-repeat nucleoporin, TbNup53b, that has dual localizations within the nucleoplasm and NPC. In addition to association with nucleoporins, TbNup53b interacts with a known trans-splicing component, TSR1, and has a role in controlling expression of surface proteins including the nucleolar periphery-located, procyclin genes. Significantly, while several nucleoporins are implicated in intranuclear transcriptional regulation in metazoa, TbNup53b appears orthologous to components of the yeast/human Nup49/Nup58 complex, for which no transcriptional functions are known. These data suggest that FG-Nups are frequently co-opted to transcriptional functions during evolution and extend the presence of FG-repeat nucleoporin control of gene expression to trypanosomes, suggesting that this is a widespread and ancient eukaryotic feature, as well as underscoring once more flexibility within nucleoporin function
Heterochromatin Protein 1β (HP1β) has distinct functions and distinct nuclear distribution in pluripotent versus differentiated cells
Background: Pluripotent embryonic stem cells (ESCs) have the unique ability to differentiate into every cell type and to self-renew. These characteristics correlate with a distinct nuclear architecture, epigenetic signatures enriched for active chromatin marks and hyperdynamic binding of structural chromatin proteins. Recently, several chromatin-related proteins have been shown to regulate ESC pluripotency and/or differentiation, yet the role of the major heterochromatin proteins in pluripotency is unknown. Results: Here we identify Heterochromatin Protein 1β (HP1β) as an essential protein for proper differentiation, and, unexpectedly, for the maintenance of pluripotency in ESCs. In pluripotent and differentiated cells HP1β is differentially localized and differentially associated with chromatin. Deletion of HP1β, but not HP1aα, in ESCs provokes a loss of the morphological and proliferative characteristics of embryonic pluripotent cells, reduces expression of pluripotency factors and causes aberrant differentiation. However, in differentiated cells, loss of HP1β has the opposite effect, perturbing maintenance of the differentiation state and facilitating reprogramming to an induced pluripotent state. Microscopy, biochemical fractionation and chromatin immunoprecipitation reveal a diffuse nucleoplasmic distribution, weak association with chromatin and high expression levels for HP1β in ESCs. The minor fraction of HP1β that is chromatin-bound in ESCs is enriched within exons, unlike the situation in differentiated cells, where it binds heterochromatic satellite repeats and chromocenters. Conclusions: We demonstrate an unexpected duality in the role of HP1β: it is essential in ESCs for maintaining pluripotency, while it is required for proper differentiation in differentiated cells. Thus, HP1β function both depends on, and regulates, the pluripotent state
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