1,751 research outputs found
Leucine-rich diet supplementation modulates foetal muscle protein metabolism impaired by Walker-256 tumour
Cancer-cachexia induces a variety of metabolic disorders of protein turnover and is more pronounced when associated with pregnancy. Tumour-bearing pregnant rats have impaired protein balance, which decreases protein synthesis and increases muscle breakdown. Because branched-chain amino acids, especially leucine, stimulate protein synthesis, we investigated the effect of a leucine-rich diet on protein metabolism in the foetal gastrocnemius muscles of tumour-bearing pregnant rats. Foetuses of pregnant rats with or without Walker 256 tumours were divided into six groups. During the 20 days of the experiment, the pregnant groups were fed with either a control diet (C, control rats; W, tumour-bearing rats; Cp, rats pair-fed the same normoprotein-diet as the W group) or with a leucine-rich diet (L, leucine rats; LW, leucine tumour-bearing rats; and Lp, rats pair-fed the same leucine-rich diet as the LW group). After the mothers were sacrificed, the foetal gastrocnemius muscle samples were resected, and the protein synthesis and degradation and tissue chymotrypsin-like, cathepsin and calpain enzyme activities were assayed. The muscle oxidative enzymes (catalase, glutathione-S-transferase and superoxide dismutase), alkaline phosphatase enzyme activities and lipid peroxidation (malondialdehyde) were also measured. Tumour growth led to a reduction in foetal weight associated with decreased serum protein, albumin and glucose levels and low haematocrit in the foetuses of the W group, whereas in the LW foetuses, these changes were less pronounced. Muscle protein synthesis (measured by L-[3H]-phenylalanine incorporation) was reduced in the W foetuses but was restored in the LW group. Protein breakdown (as assessed by tyrosine release) was enhanced in the L and W groups, but chymotrypsin-like activity increased only in group W and tended toward an increase in the LW foetuses. The activity of cathepsin H was significantly higher in the W group foetuses, but the proteolytic calcium-dependent pathway showed similar enzyme activity. In parallel, an intense oxidative stress process was observed only in the group W foetuses. These data suggested that the proteasomal and lysosomal proteolytic pathways and oxidative stress are likely to participate in the process of foetal muscle catabolism of Walker's tumour-bearing pregnant rats. The present work shows that foetal muscle can be protected by supplementation with a leucine-rich diet
Influencia de la divergencia facial en la posición y angulación del hueso hioides en sujetos con diferentes maloclusiones
OBJETIVO: Comparar la posición vertical, horizontal e inclinación del hueso hioides en radiografías laterales de cabezade pacientes con diferentes maloclusiones y divergencia facial.MATERIALES Y MÉTODOS: Se realizaron 13 mediciones cefalométricas en 181 sujetos, divididos en 7 grupos: Normodivergentes Clase I (n=31), Clase II (n=31) y Clase III (n=31); Hiperdivergentes Clase II (n=30), Clase III (n=20) e Hipodivergentes Clase II (n=18), Clase III (n=20). Las medidas obtenidas compararon la posición anteroposterior, vertical e inclinación del hueso hioides en relación al cuerpo mandibular y a los otros planos esqueléticos de referencia. Las pruebas estadísticas utilizadas fueron Anova y comparaciones múltiples de Tukey.RESULTADOS: Sólo se encontraron diferencias significativas al comparar la posición horizontal del hueso hioides entreClase II hiperdivergente y Clase III normo e hipodivergente, lo mismo para Clase II normodivergente en comparacióncon Clase III normo e hipodivergente. No se encontraron diferencias significativas en la posición vertical ni en la angulación del hueso hioides entre las clases esqueléticas ni en el patrón vertical.CONCLUSIÓN: La posición horizontal del hueso hioides se ve afectado principalmente en la Clase II hiperdivergente ynormodivergente encontrándose retrasada a diferencia de las otras maloclusiones. La posición vertical y angulación delhueso hioides no se ven afectadas por la maloclusión y el patrón vertical
Dynamic Environmental Photosynthetic Imaging Reveals Emergent Phenotypes.
Understanding and improving the productivity and robustness of plant photosynthesis requires high-throughput phenotyping under environmental conditions that are relevant to the field. Here we demonstrate the dynamic environmental photosynthesis imager (DEPI), an experimental platform for integrated, continuous, and high-throughput measurements of photosynthetic parameters during plant growth under reproducible yet dynamic environmental conditions. Using parallel imagers obviates the need to move plants or sensors, reducing artifacts and allowing simultaneous measurement on large numbers of plants. As a result, DEPI can reveal phenotypes that are not evident under standard laboratory conditions but emerge under progressively more dynamic illumination. We show examples in mutants of Arabidopsis of such "emergent phenotypes" that are highly transient and heterogeneous, appearing in different leaves under different conditions and depending in complex ways on both environmental conditions and plant developmental age. These emergent phenotypes appear to be caused by a range of phenomena, suggesting that such previously unseen processes are critical for plant responses to dynamic environments
Evaluation of Xpert® MTB/RIF and ustar easyNAT™ TB IAD for diagnosis of tuberculous lymphadenitis of children in Tanzania : a prospective descriptive study
Fine needle aspiration biopsy has become a standard approach for diagnosis of peripheral tuberculous lymphadenitis. The aim of this study was to compare the performance of Xpert MTB/RIF and Ustar EasyNAT TB IAD nucleic acid amplification assays, against acid-fast bacilli microscopy, cytology and mycobacterial culture for the diagnosis of TB lymphadenitis in children from a TB-endemic setting in Tanzania.; Children of 8 weeks to 16 years of age, suspected of having TB lymphadenitis, were recruited at a district hospital in Tanzania. Fine needle aspirates of lymph nodes were analysed using acid-fast bacilli microscopy, liquid TB culture, cytology, Xpert MTB/RIF and EasyNAT. Latent class analysis and comparison against a composite reference standard comprising "culture and/or cytology" was done, to assess the performance of Xpert MTB/RIF and EasyNAT for the diagnosis of TB lymphadenitis.; Seventy-nine children were recruited; 4 were excluded from analysis. Against a composite reference standard of culture and/or cytology, Xpert MTB/RIF and EasyNAT had a sensitivity and specificity of 58 % and 93 %; and 19 % and 100 % respectively. Relative to latent class definitions, cytology had a sensitivity of 100 % and specificity of 94.7 %.; Combining clinical assessment, cytology and Xpert MTB/RIF may allow for a rapid and accurate diagnosis of childhood TB lymphadenitis. Larger diagnostic evaluation studies are recommended to validate these findings and on Xpert MTB/RIF to assess its use as a solitary initial test for TB lymphadenitis in children
Stem cell differentiation increases membrane-actin adhesion regulating cell blebability, migration and mechanics
This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder in order to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/K. S. is funded by an EPSRC PhD studentship. S.T. is funded by an EU Marie Curie Intra European Fellowship (GENOMICDIFF)
Integer and half-integer flux-quantum transitions in a niobium/iron-pnictide loop
The recent discovery of iron-based superconductors challenges the existing
paradigm of high-temperature superconductivity. Owing to their unusual
multi-orbital band structure, magnetism, and electron correlation, theories
propose a unique sign reversed s-wave pairing state, with the order parameter
changing sign between the electron and hole Fermi pockets. However, because of
the complex Fermi surface topology and material related issues, the predicted
sign reversal remains unconfirmed. Here we report a novel phase-sensitive
technique for probing unconventional pairing symmetry in the polycrystalline
iron-pnictides. Through the observation of both integer and half-integer
flux-quantum transitions in composite niobium/iron-pnictide loops, we provide
the first phase-sensitive evidence of the sign change of the order parameter in
NdFeAsO0.88F0.12, lending strong support for microscopic models predicting
unconventional s-wave pairing symmetry. These findings have important
implications on the mechanism of pnictide superconductivity, and lay the
groundwork for future studies of new physics arising from the exotic order in
the FeAs-based superconductors.Comment: 23 pages, including 4 figures and supplementary informatio
Digital Elevation Models: Terminology and Definitions
Digital elevation models (DEMs) provide fundamental depictions of the three-dimensional shape of the Earth’s surface and are useful to a wide range of disciplines. Ideally, DEMs record the interface between the atmosphere and the lithosphere using a discrete two-dimensional grid, with complexities introduced by the intervening hydrosphere, cryosphere, biosphere, and anthroposphere. The treatment of DEM surfaces, affected by these intervening spheres, depends on their intended use, and the characteristics of the sensors that were used to create them. DEM is a general term, and more specific terms such as digital surface model (DSM) or digital terrain model (DTM) record the treatment of the intermediate surfaces. Several global DEMs generated with optical (visible and near-infrared) sensors and synthetic aperture radar (SAR), as well as single/multi-beam sonars and products of satellite altimetry, share the common characteristic of a georectified, gridded storage structure. Nevertheless, not all DEMs share the same vertical datum, not all use the same convention for the area on the ground represented by each pixel in the DEM, and some of them have variable data spacings depending on the latitude. This paper highlights the importance of knowing, understanding and reflecting on the sensor and DEM characteristics and consolidates terminology and definitions of key concepts to facilitate a common understanding among the growing community of DEM users, who do not necessarily share the same backgroun
Challenges in clinical and laboratory diagnosis of androgen insensitivity syndrome: a case report
<p>Abstract</p> <p>Introduction</p> <p>Androgen is a generic term usually applied to describe a group of sex steroid hormones. Androgens are responsible for male sex differentiation during embryogenesis at the sixth or seventh week of gestation, triggering the development of the testes and penis in male fetuses, and are directed by the testicular determining factor: the gene <it>SRY </it>(sex determining region on Y chromosome) located on the short arm of chromosome Y. The differentiation of male external genitalia (penis, scrotum and penile urethra) occurs between the 9th and 13th weeks of pregnancy and requires adequate concentration of testosterone and the conversion of this to another more potent androgen, dihydrotestosterone, through the action of 5α-reductase in target tissues.</p> <p>Case presentation</p> <p>This report describes the case of a teenage girl presenting with a male karyotype, and aims to determine the extension of the mutation that affected the AR gene. A Caucasian girl aged 15 was referred to our laboratory for genetic testing due to primary amenorrhea. Physical examination, karyotype testing and molecular analysis of the androgen receptor were critical in making the correct diagnosis of complete androgen insensitivity syndrome.</p> <p>Conclusions</p> <p>Sex determination and differentiation depend on a cascade of events that begins with the establishment of chromosomal sex at fertilization and ends with sexual maturation at puberty, subsequently leading to fertility. Mutations affecting the <it>AR </it>gene may cause either complete or partial androgen insensitivity syndrome. The case reported here is consistent with complete androgen insensitivity syndrome, misdiagnosed at birth, and consequently our patient was raised both socially and educationally as a female. It is critical that health care providers understand the importance of properly diagnosing a newborn manifesting ambiguous genitalia. Furthermore, a child with a pseudohermaphrodite phenotype should always undergo adequate endocrine and genetic testing to reach a conclusive diagnosis before gender is assigned and surgical interventions are carried out. Our results show that extreme care must be taken in selecting the genetic tools that are utilized for the diagnosis for androgen insensitivity syndrome.</p
New insights into the classification and nomenclature of cortical GABAergic interneurons.
A systematic classification and accepted nomenclature of neuron types is much needed but is currently lacking. This article describes a possible taxonomical solution for classifying GABAergic interneurons of the cerebral cortex based on a novel, web-based interactive system that allows experts to classify neurons with pre-determined criteria. Using Bayesian analysis and clustering algorithms on the resulting data, we investigated the suitability of several anatomical terms and neuron names for cortical GABAergic interneurons. Moreover, we show that supervised classification models could automatically categorize interneurons in agreement with experts' assignments. These results demonstrate a practical and objective approach to the naming, characterization and classification of neurons based on community consensus
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