84 research outputs found
Antiretroviral Treatment in HIV-1-Positive Mothers: Neurological Implications in Virus-Free Children
Since the worldwide introduction of antiretroviral therapy (ART) in human immunodeficiency virus type 1, HIV-1-positive mothers, together with HIV-1 testing prior to pregnancy, caesarian birth and breastfeeding cessation with replacement feeding, a reduction of HIV-1 mother-to-child transmission (MTCT) has been observed in the last few years. As such, an increasing number of children are being exposed in utero to ART. Several questions have arisen concerning the neurological effects of ART exposure in utero, considering the potential effect of antiretroviral drugs on the central nervous system, a structure which is in continuous development in the fetus and characterized by great plasticity. This review aims at discussing the possible neurological impairment of children exposed to ART in utero, focusing attention on the drugs commonly used for HIV-1 MTCT prevention, clinical reports of ART neurotoxicity in children born to HIV-1-positive mothers, and neurologic effects of protease inhibitors (PIs), especially ritonavir-"boosted" lopinavir (LPV/r) in cell and animal central nervous system models evaluating the potential neurotoxic effect of ART. Finally, we present the findings of a meta-analysis to assess the effects on the neurodevelopment of children exposed to ART in utero
A method for estimating superplastic material parameters via free-inflation tests
In this work, a new methodology for evaluating the constitutive parameters of superplastic materials is presented. The proposed methodology provides the characterization of the material by means of a variable called apparent viscosity. This variable is calculated for three different materials through data collected by free inflation tests made at different temperatures and pressure values. The apparent viscosity was then used to calculate some material parameters by which the experimental tests were reproduced numerically in a finite element commercial code. The results obtained by numerical simulations were compared both with the experimental ones and with ones deriving by simulations run with material parameters calculated by a commonly used methodology. The proposed approach revealed to have a good prediction capability with deviations lower than the one found by the approach taken as reference. A second validation step was then performed by comparing the stress and strain-rate values found through the proposed methodology with the curves constructed by applying uniaxial tests results from literature. This latter comparison showed that results fit well with the behaviour shown using the standardised uniaxial tests
Zoledronic acid blocks overactive Kir6.1/SUR2-dependent KATP channels in skeletal muscle and osteoblasts in a murine model of CantĂş syndrome
CantĂş syndrome (CS) is caused by the gain of function mutations in th
Molecular determinants for the activating/blocking actions of the 2H-1,4-benzoxazine derivatives, a class of potassium channel modulators targeting the skeletal muscle KATP channels
The 2H-1,4-benzoxazine derivatives are modulators of the skeletal muscle ATP-sensitive-K+ channels (KATP), activating it in the presence of ATP but inhibiting it in the absence of nucleotide. To investigate the molecular determinants for the activating/blocking actions of these compounds, novel molecules with different alkyl or aryl-alkyl substitutes at position 2 of the 1,4-benzoxazine ring were prepared. The effects of the lengthening of the alkyl chain and of branched substitutes, as well as of the introduction of aliphatic/aromatic rings on the activity of the molecules, were investigated on the skeletal muscle KATP channels of the rat, in excised-patch experiments, in the presence or absence of internal ATP (10 -4 M). In the presence of ATP, the 2-n-hexyl analog was the most potent activator (DE50 = 1.08 × 10-10 M), whereas the 2-phenylethyl was not effective. The rank order of efficacy of the openers was 2-n-hexyl ≥2-cyclohexylmethyl >2-isopropyl = 2-n-butyl = 2-phenyl ≥ 2-benzyl = 2-isobutyl analogs. In the absence of ATP, the 2-phenyl analog was the most potent inhibitor (IC50 = 2.5 × 10-11 M); the rank order of efficacy of the blockers was 2-phenyl ≥ 2-n-hexyl > 2-n-butyl > 2-cyclohexylmethyl, whereas the 2-phenylethyl, 2-benzyl, and 2-isobutyl 1,4-benzoxazine analogs were not effective; the 2-isopropyl analog activated the KATP channel even in the absence of nucleotide. Therefore, distinct molecular determinants for the activating or blocking actions for these compounds can be found. For example, the replacement of the linear with the branched alkyl substitutes at the position 2 of the 1,4-benzoxazine nucleus determines the molecular switch from blockers to openers. These compounds were 100-fold more potent and effective as openers than other KCO against the muscle KATP channels. Copyright © 2008 The American Society for Pharmacology and Experimental Therapeutics
Structural nucleotide analogs are potent activators/inhibitors of pancreatic beta-cell KATP channels: an emerging mechanism supporting their use as anti-diabetic drugs.
The 2H-1,4-benzoxazine derivatives are novel drugs structurally similar to nucleotides; however, their actions on the pancreatic beta-cell ATP-sensitive-K(+)(KATP) channel and on glucose disposal are unknown. Therefore, the effects of the linear/branched alkyl substituents and the aliphatic/aromatic rings at position 2 of the 2H-1,4-benzoxazine nucleus on the activity of these molecules against the pancreatic beta-cell KATP channel and the Kir6.2C36 subunit were investigated using a patch-clamp technique. The effects of these compounds on glucose disposal that followed glucose loading by i.p. GTT and on fasted glycemia were investigated in normal mice. The 2-n-hexyl analog blocked the KATP(IC50=10.1x10(-9)M) and Kir6.2C36(IC50=9.6x10(-9)M) channels which induced depolarization. In contrast, the 2-phenyl analog was a potent opener(DE50=0.04x10(-9)M), which induced hyperpolarization. The ranked order of the potency/efficacy of the analog openers was 2-phenyl>2-benzyl>2-cyclohexylmethyl. The 2-phenylethyl and 2-isopropyl analogs were not effective as blockers/openers. The 2-n-hexyl (2-10 mg kg(-1)) and 2-phenyl analogs (2-30 mg kg(-1)) reduced and enhanced the glucose AUC curves, respectively, following the glucose loading in mice. These compounds did not affect the fasted glycemia as is observed with glibenclamide. The linear alkyl chain and the aromatic ring at position 2 of the 1,4-benzoxazine nucleus are the determinants, which respectively confer the KATP channel blocking action with glucose lowering effects and the opening action with increased glucose levels. The opening/blocking actions of these compounds mimic those that were observed with ATP and ADP. The results support the use of these compounds as novel anti-diabetic drugs
Plasma Plume Oscillations Monitoring during Laser Welding of Stainless Steel by Discrete Wavelet Transform Application
The plasma optical radiation emitted during CO2 laser welding of stainless steel samples has been detected with a Si-PIN photodiode and analyzed under different process conditions. The discrete wavelet transform (DWT) has been used to decompose the optical signal into various discrete series of sequences over different frequency bands. The results show that changes of the process settings may yield different signal features in the range of frequencies between 200 Hz and 30 kHz. Potential applications of this method to monitor in real time the laser welding processes are also discussed
First interception of Acrossidius tasmaniae (Hope, 1847) (Coleoptera Scarabaeidae Aphodiinae) in Europe
In April 2013, four adults of Acrossidius tasmaniae (Hope, 1847) (Coleoptera Scarabaeidae Aphodiinae) were found during the inspection of the Phytosanitary Service of Tuscany Region in the port of Leghorn, in a container from New Zealand. This is the first interception of this minor pest for cultivated plants in Europe.
Transcriptome Meta-Analysis Confirms the Hidradenitis Suppurativa Pathogenic Triad: Upregulated Inflammation, Altered Epithelial Organization, and Dysregulated Metabolic Signaling
Hidradenitis suppurativa (HS) is an inflammatory skin condition clinically characterized by recurrent painful deep-seated nodules, abscesses, and sinus tracks in areas bearing apocrine glands, such as axillae, breasts, groins, and buttocks. Despite many recent advances, the pathophysiological landscape of HS still demands further clarification. To elucidate HS pathogenesis, we performed a meta-analysis, set analysis, and a variant calling on selected RNA-Sequencing (RNA-Seq) studies on HS skin. Our findings corroborate the HS triad composed of upregulated inflammation, altered epithelial differentiation, and dysregulated metabolism signaling. Upregulation of specific genes, such as KRT6, KRT16, serpin-family genes, and SPRR3 confirms the early involvement of hair follicles and the impairment of barrier function in HS lesioned skin. In addition, our results suggest that adipokines could be regarded as biomarkers of HS and metabolic-related disorders. Finally, the RNA-Seq variant calling identified several mutations in HS patients, suggesting potential new HS-related genes associated with the sporadic form of this disease. Overall, this study provides insights into the molecular pathways involved in HS and identifies potential HS-related biomarkers.This work was supported by “Coordenação de Aperfeiçoamento de Pessoal de NĂvel Superior—Brasil (CAPES)”—Finance Code 001, Fondation RenĂ© Touraine, “Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq)” (311415/2020-2 and 430353/2018-9), and EraPerMed 2018-17 European Community funds. L.A.C.B. is supported by CNPq (311415/2020-2). This work was also supported by the Italian Ministry of Health, through the contribution given to the Institute for Maternal and Child Health IRCCS Burlo Garofolo, Trieste, Italy for the Starting Grant (SG-2019-12369421) and for RC03/2020
- …