3,880 research outputs found
hrGH treatment of glucocorticoid-induced short stature in children
O uso crônico de glicocorticóides no tratamento de doenças sistêmicas causa diminuição da velocidade de crescimento (VC), podendo acarretar perda estatural final. As interações entre o eixo adrenal e o eixo GH-sistema IGF têm sido descritas, podendo ocorrer em nível hipotalâmico-hipofisário e na regulação do sistema IGF, inclusive modulando o sinal do IGF-1R. Pode-se dizer que o quadro clínico deve ser considerado como estado de deficiência de Igf-1, absoluta e/ou funcional. As intervenções que possibilitam a normalização funcional do eixo GH-IGF poderiam reduzir a perda estatural destas crianças. Os estudos realizados em pacientes com artrite reumatóide juvenil em tratamento com corticóides mostraram aceleração da VC e diminuição da perda protéica com o uso de GH recombinante humano (hrGH). A aceleração da VC foi também descrita em pacientes sob corticoterapia crônica por causa da doença intestinal inflamatória ou do transplante renal após o uso de hrGH. A dose de hrGH guarda correlação positiva com a aceleração da VC e os resultados reforçam que esta deficiência funcional do eixo GH-IGF pode ser revertida com a administração de hrGH. O efeito do hrGH é restrito ao período de tratamento e depende do esquema de reposição do hrGH, do estado nutricional e das condições da doença de base.The treatment of systemic diseases with glucocorticoids is often associated with decreased height velocity (HV), and can result in shorter final height. Interactions between adrenal and GH-IGF axis have been described and can occur at hypothalamic-pituitary level or at the regulation of IGF system, including the IGF1R signaling. The clinical state of these patients may be considered as an absolute and/or functional IGF-1 deficiency. Interventions aiming to restore the normal function of GH-IGF axis might reduce the glucocorticoids-induced growth suppression in these children. It has been shown that recombinant human GH (hrGH) induces an increase in HV and a decrease in protein loss in patients with juvenile idiopathic arthritis treated with glucocorticoids. Significant increment in HV was also described after hrGH treatment in children under glucocorticoid therapy due to inflammatory bowel disease or renal transplantation. There is a positive correlation between HV and the dose of hrGH. The results support that the IGF-1 deficiency in these children may be counteract by hrGH therapy. The effect of hrGH is observed only during the treatment period and depends on the replacement strategy, nutritional status and disease control
Argon Abundances in the Solar Neighborhood: Non-LTE Analysis of Orion Association B-type Stars
Argon abundances have been derived for a sample of B main-sequence stars in
the Orion association. The abundance calculations are based on NLTE metal
line-blanketed model atmospheres calculated with the NLTE code TLUSTY and an
updated and complete argon model atom. We derive an average argon abundance for
this young population of A(Ar) = 6.66 +- 0.06. While our result is in excellent
agreement with a recent analysis of the Orion nebula, it is significantly
higher than the currently recommended solar value which is based on abundance
measurements in the solar corona. Moreover, the derived argon abundances in the
Orion B stars agree very well with a measurement from a solar impulsive flare
during which unmodified solar photospheric material was brought to flare
conditions. We therefore argue that the argon abundances obtained independently
for both the Orion B stars and the Orion nebula are representative of the disk
abundance value in the solar neighborhood. The lower coronal abundance may
reflect a depletion related to the FIP effect. We propose a new reference value
for the abundance of argon in the solar neighborhood, A(Ar) = 6.63 +- 0.10,
corresponding to Ar/O = 0.009.Comment: to appear in Astrophysical Journal, 24 pages, 3 figures; minor
corrections after referee's repor
Macrophages down-regulate gene expression of intervertebral disc degenerative markers under a pro-inflammatory microenvironment
Low back pain is a highly prevalent clinical problem and intervertebral disc (IVD) degeneration is now accepted as the major pathophysiological mechanism responsible for this condition. Accumulating evidence suggests that inflammation plays a crucial role in the progression of human IVD degeneration, with macrophages being pointed as the key immune cell players in this process since their infiltration in degenerated IVD samples has been extensively demonstrated. Since they are highly plastic, macrophages can play different roles depending on the microenvironmental cues. The study of inflammation associated with IVD degeneration has been somehow neglected and one of the reasons is related with lack of adequate models. To overcome this, we established and characterized a new model of IVD organ culture under proinflammatory conditions to further dissect the role of macrophages in IVD associated immune response. For that, human monocyte-derived macrophages were co-cultured either with bovine caudal IVD punches in the presence of the pro-inflammatory cytokine IL-1ß, or IVD-conditioned medium (CM), to investigate how IVD-produced factors influence macrophage phenotype. After 72 h, metabolic activity, gene expression and cytokine profile of macrophages and IVD cells were measured. Our results show that macrophages and IVDs remain metabolically active in the presence of IL-1ß, significantly upregulate CCR7 gene expression and increase production of IL-6 on macrophages. When treating macrophages with IL-1ß-IVD-CM, CCR7 upregulation follows the same trend, while for IL-6 an opposite effect was observed. On the other hand, macrophages interfere with IVD ECM remodeling, decreasing MMP3 expression and downregulating aggrecan and collagen II gene expression in the presence of IL-1ß. Overall, the co-culture model established in this study can be considered a suitable approach to address the cellular and molecular pathways that regulate macrophage-IVD crosstalk, suggesting that degenerated IVD tissue tends to polarize human macrophages toward a more proinflammatory profile, which seems to aggravate IVD degeneration. This model could be used to improve the knowledge of the mechanisms that link IVD degeneration and the immune response.This work was financed by European Union funds through Bioengineered Therapies for infectious diseases and tissue regeneration (Norte-01-0145-FEDER-000012), Projetos Estruturados de I& D& I - Norte-01-0145-FEDER-000012, Portugal 2020 - FEDER, and through EUROSPINE TRF (2017_05) by the project Disc degeneration-, immune-, and neuro-modulation. The authors also acknowledge FCT – Fundação para a Ciência e a Tecnologia, in the framework of the FCT Investigator Grant of RMG (IF/00638/2014), CC Junior Research contract (DL 57/2016/CP1360/CT0004) and the Ph.D. grant of JF (PD/BI/128357/2017). The authors would like to thank Serviço de Imunohemoterapia of Centro Hospitalar Universitário de São João (CHUSJ), for kindly donating Buffy Coats
Effect of Nonionic Surfactants on the Crystallinity and Thermal Stability of Poly(vinyl alcohol) Film
In this study, poly(vinyl alcohol) (PVA)/surfactant films were prepared by casting technique. Two nonionic surfactants with different alkyl chain lenghts (Tween 20 and Tween 40) were used. PVA/Tween 20 and PVA/Tween 40 films were characterized by means of Fourier Transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). FTIR spectra of PVA/Tween films indicated the presence of hydrogen bond interactions between the Tween surfactants and PVA. XRD results showed that the incorporation of Tween 20 and 40 into the PVA film decreased the crystallinity of PVA.TGA curves revealed an increase in the thermal stability of PVA film in the presence of the surfactants.
DOI: http://dx.doi.org/10.17807/orbital.v12i4.151
Wireless ad hoc networks on underserved communities: an efficient solution for interactive digital TV
The Brazilian government intends to use the Digital TV technology as a vehicle of digital inclusion on underserved communities.
The wireless ad hoc network is a low-cost, scalable and easy solution to implement the return channel. This work analyzes the performance of an ad hoc return channel using the wireless IEEE 802.11 technology in different Brazilian geographical scenarios. The results show that a high connectivity is achieved when more than 20% of the nodes are turned on, regardless of the position of the gateway. The influence of the number of hops and the number of transmitting nodes is also analyzed. A minimum throughput of 2 Mbps can be reached for increasing number of hops in the forwarding chain for a one-node transmission. Besides, when the number of transmitting nodes increases, the aggregated throughput can achieve 3.5 Mbps. The results show that the ad hoc network is a promising solution for the return channel of the interactive Digital TV.8th IFIP/IEEE International conference on Mobile and Wireless CommunicationRed de Universidades con Carreras en Informática (RedUNCI
Optimization of clavulanic acid production by Streptomyces daufpe 3060 by response surface methodology
Clavulanic acid is a β-lactam antibiotic which has a potent β-lactamase inhibiting activity. In order to optimize its production by the new isolate Streptomyces DAUFPE 3060, the influence of two independent variables, temperature and soybean flour concentration, on clavulanic acid and biomass concentrations was investigated in 250 mL-Erlenmeyers according to a 2² central composite design. To this purpose, temperature and soybean flour (SF) concentration were varied in the ranges 26-34°C and 10-50 g/L, respectively, and the results evaluated utilizing the Response Surface Methodology. The experimental maximum production of clavulanic acid (629 mg/L) was obtained at 32°C and 40 g/L SF after 48 h, while the maximum biomass concentration (3.9 g/L) at 30°C and 50 g/L soybean flour, respectively. These values are satisfactorily close to those (640 mg/L and 3.75 g/L, respectively) predicted by the model, thereby demonstrating the validity of the mathematical approach adopted in this study.Brazilian Research Funding InstitutionsCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES
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