Zinc oxide nanoparticles as selective killers of proliferating cells

Background: It has recently been demonstrated that zinc oxide nanoparticles (ZnO NPs) induce death of cancerous cells whilst having no cytotoxic effect on normal cells. However, there are several issues which need to be resolved before translation of zinc oxide nanoparticles into medical use, including lack of suitable biocompatible dispersion protocols and a better understanding being needed of the mechanism of their selective cytotoxic action. Methods: Nanoparticle dose affecting cell viability was evaluated in a model of proliferating cells both experimentally and mathematically. The key issue of selective toxicity of ZnO NPs toward proliferating cells was addressed by experiments using a biological model of noncancerous cells, ie, mesenchymal stem cells before and after cell differentiation to the osteogenic lineage. Results: In this paper, we report a biocompatible protocol for preparation of stable aqueous solutions of monodispersed zinc oxide nanoparticles. We found that the threshold of intracellular ZnO NP concentration required to induce cell death in proliferating cells is 0.4 ± 0.02 mM. Finally, flow cytometry analysis revealed that the threshold dose of zinc oxide nanoparticles was lethal to proliferating pluripotent mesenchymal stem cells but exhibited negligible cytotoxic effects to osteogenically differentiated mesenchymal stem cells. Conclusion: Results confirm the ZnO NP selective cytotoxic action on rapidly proliferating cells, whether benign or malignant

Percepções de professores e alunos de uma região semiárida brasileira sobre educação ambiental e água

A água se constitui em um tema muito adequado para a realização de atividades de educação ambiental. No entanto, o conhecimento prévio sobre a concepção dos envolvidos nestas atividades através de pesquisas de percepção ambiental pode ajudar a dinamizar o processo de sensibilização. Com o objetivo de entender a concepção de professores e alunos da rede pública de uma cidade de região semiárida nordestina sobre o desenvolvimento de atividades de educação ambiental relacionadas ao tema água foi aplicado um questionário, como instrumento de coleta. A análise dos dados permitiu observar os professores se dizem envolvidos em atividades de educação ambiental e desenvolvem ações para minimizar os problemas da água, no entanto, não revelam concretamente como fazem isso, além de os alunos participarem pouco dessas ações

Auditory disorders and acquisition of the ability to localize sound in children born to HIV-positive mothers

The objective of the present study was to evaluate children born to HIV-infected mothers and to determine whether such children present auditory disorders or poor acquisition of the ability to localize sound. The population studied included 143 children (82 males and 61 females), ranging in age from one month to 30 months. The children were divided into three groups according to the classification system devised in 1994 by the Centers for Disease Control and Prevention: infected; seroreverted; and exposed. The children were then submitted to audiological evaluation, including behavioral audiometry, visual reinforcement audiometry and measurement of acoustic immittance. Statistical analysis showed that the incidence of auditory disorders was significantly higher in the infected group. In the seroreverted and exposed groups, there was a marked absence of auditory disorders. In the infected group as a whole, the findings were suggestive of central auditory disorders. Evolution of the ability to localize sound was found to be poorer among the children in the infected group than among those in the seroreverted and exposed groups.University of São Paulo School Infectious Diseases Division Department of PediatricsFederal University of São Paulo Department of Speech-Language and Hearing ScienceFederal University of São Paulo Department of Pediatric InfectologyUNIFESP, Department of Speech-Language and Hearing ScienceUNIFESP, Department of Pediatric InfectologySciEL

Spheroids from equine amnion mesenchymal stem cells: an in vitro study

Background: Equine amnion mesenchymal stem cells (EAMSCs) from amnion isolated after the foal birth represented an alternative source of easy collection of mesenchymal cells used in equine regenerative medicine. Methods: These cells grown as 2D culture in α-MEM medium supplemented with EGF were differentiated in adipogenic, chondrogenic and osteogenic cells. Half a million cells as pellet were left in 15ml tubes with the same differentiation media for 20 days. After the pellets were collected, embedded in paraffin for morphological study. Results: 2D culture showed EAMSCs with an embryonic phenotype (C-kit+, CD105+, Oct-4+) and a differentiation potential in adipogenic, chondrogenic and osteogenic multipotent cells. By a reproducible method of 3D culture, at day 20 the Authors evidenced a formation of small aggregated spheroids gradually gathering. In cross sections the surface of spheroid evidenced flattened cells embedded in a red matrix by Alizarin staining and occasionally a core of calcium precipitation. A network of apoptotic or necrotic cells in a not mineralized matrix was present into the center of nodules. The 3D spheroids appeared larger (mean diameter of 605±53 µm for gathering spheroids and 1486±79 µm for spheroids already gathered) than those from standard monolayer cultures (mean diameter of 200 ± 73 µm). Conclusions: EAMSCs cultured in 3D method preserve their in vitro multipotent differentiation than adherent 2D culture method. These EAMSCs included in extracellular matrix not mineralized at day 20 seem to be a good source of MSCs for tissue repair and regeneration in equine medicine

3-D Fibrin Scaffold Improves Stemness of Human Peripheral Blood Endothelial Progenitor Cells

Aims Fibrin is a natural biopolymer appealing for cell-based regenerative therapies, because it can support growth, migration and differentiation of different cell types. Endothelial progenitor cells (EPC) represent a very interesting alternative cell source for mature endothelial cells; the fact that can easily isolated from the peripheral blood, thereby eliminating donor morbidity, makes them ideal in applications in the field of regenerative medicine. We have demonstrated that fibrin can support EPC viability and growth. Aim of this study was to evaluate if fibrin can affect EPC differentiation and stem cell markers expression. Methods Fibrin was prepared mixing commercially available (Kedrion S.p.A. Lucca, Italy) fibrinogen (9 mg/ml) and thrombin (25 U/ml). Clot ultrastructure was investigated by scanning electron microscopy (SEM) and cryogenic SEM (CRYO-SEM) to measure fibre diameter and density. Clot elasticity was evaluated by atomic force microscopy (AFM), measuring the tip-sample force by cantilever displacement. EPC were obtained from peripheral blood and cultured on fibrin at the concentration of 1x106cell/cm2. Fibronectin coating was used as a control. Metabolic activity was assessed after 7 and 14 days by WST1 assay and viability by confocal microscopy (calcein incorporation). The expression of both endothelial (CD31, KDR, vWF, Ve-Cadherin) and stem cell markers (nanog, oct-4) was assessed by flow cytometry, confocal microscopy and Real Time RT-PCR. Results SEM analysis revealed a nanometric fibrous structure, with mean fiber diameter of 165?4 nm and mean density of 95.9?0.2 %. CRYO-SEM suggested a reticulate structure with mesh-size up to 10 ?m. Fibrin clot elasticity was 1.78 MPa, as in literature. WST1 assay showed that fibrin increased EPC metabolic activity as compared to fibronectin (fibrin: 0.606?0.056 a.u. vs. fibronectin: 0.311?0.067). Calcein staining demonstrated that EPC were still viable at 14 days. Flow cytometry showed the expression of endothelial markers (CD31=41.8?8.4%; vWF=32.3?3.0%; KDR=89.3?3.7%; VE-Cadherin=41.2?3.8%), confirmed also by confocal microscopy and Real Time RT-PCR. Interestingly, nanog and oct-4 (embryonic stem cell markers) expression was significantly greater on fibrin (p<0.001) as compared to fibronectin. Conclusions These findings suggest that fibrin it is not only a suitable scaffold for EPC growth and viability but also induces EPC differentiation. The observation that Nanog, known as the most important marker of stemness, is maintained longer than on fibronectin, may offer a surplus value to stem cell-based therapies

Next Generation Molecular Diagnosis of Hereditary Spastic Paraplegias: An Italian Cross-Sectional Study

Hereditary spastic paraplegia (HSP) refers to a group of genetically heterogeneous neurodegenerative motor neuron disorders characterized by progressive age-dependent loss of corticospinal motor tract function, lower limb spasticity, and weakness. Recent clinical use of next generation sequencing (NGS) methodologies suggests that they facilitate the diagnostic approach to HSP, but the power of NGS as a first-tier diagnostic procedure is unclear. The larger-than-expected genetic heterogeneity-there are over 80 potential disease-associated genes-and frequent overlap with other clinical conditions affecting the motor system make a molecular diagnosis in HSP cumbersome and time consuming. In a single-center, cross-sectional study, spanning 4 years, 239 subjects with a clinical diagnosis of HSP underwent molecular screening of a large set of genes, using two different customized NGS panels. The latest version of our targeted sequencing panel (SpastiSure3.0) comprises 118 genes known to be associated with HSP. Using an in-house validated bioinformatics pipeline and several in silico tools to predict mutation pathogenicity, we obtained a positive diagnostic yield of 29% (70/239), whereas variants of unknown significance (VUS) were found in 86 patients (36%), and 83 cases remained unsolved. This study is among the largest screenings of consecutive HSP index cases enrolled in real-life clinical-diagnostic settings. Its results corroborate NGS as a modern, first-step procedure for molecular diagnosis of HSP. It also disclosed a significant number of new mutations in ultra-rare genes, expanding the clinical spectrum, and genetic landscape of HSP, at least in Italy

Acute Delta Hepatitis in Italy spanning three decades (1991–2019): Evidence for the effectiveness of the hepatitis B vaccination campaign

Updated incidence data of acute Delta virus hepatitis (HDV) are lacking worldwide. Our aim was to evaluate incidence of and risk factors for acute HDV in Italy after the introduction of the compulsory vaccination against hepatitis B virus (HBV) in 1991. Data were obtained from the National Surveillance System of acute viral hepatitis (SEIEVA). Independent predictors of HDV were assessed by logistic-regression analysis. The incidence of acute HDV per 1-million population declined from 3.2 cases in 1987 to 0.04 in 2019, parallel to that of acute HBV per 100,000 from 10.0 to 0.39 cases during the same period. The median age of cases increased from 27 years in the decade 1991-1999 to 44 years in the decade 2010-2019 (p &lt; .001). Over the same period, the male/female ratio decreased from 3.8 to 2.1, the proportion of coinfections increased from 55% to 75% (p = .003) and that of HBsAg positive acute hepatitis tested for by IgM anti-HDV linearly decreased from 50.1% to 34.1% (p &lt; .001). People born abroad accounted for 24.6% of cases in 2004-2010 and 32.1% in 2011-2019. In the period 2010-2019, risky sexual behaviour (O.R. 4.2; 95%CI: 1.4-12.8) was the sole independent predictor of acute HDV; conversely intravenous drug use was no longer associated (O.R. 1.25; 95%CI: 0.15-10.22) with this. In conclusion, HBV vaccination was an effective measure to control acute HDV. Intravenous drug use is no longer an efficient mode of HDV spread. Testing for IgM-anti HDV is a grey area requiring alert. Acute HDV in foreigners should be monitored in the years to come

Reduced cAMP, Akt Activation and p65-c-Rel Dimerization: Mechanisms Involved in the Protective Effects of mGluR3 Agonists in Cultured Astrocytes

In recent decades, astrocytes have emerged as key pieces in the maintenance of normal functioning of the central nervous system. Any impairment in astroglial function can ultimately lead to generalized disturbance in the brain, thus pharmacological targets associated with prevention of astrocyte death are actually promising. Subtype 3 of metabotropic glutamate receptors (mGluR3) is present in astrocytes, its activation exerting neuroprotective roles. In fact, we have previously demonstrated that mGluR3 selective agonists prevent nitric oxide (NO)-induced astrocyte death. However, mechanisms responsible for that cytoprotective property are still subject to study. Although inhibition of adenylyl cyclase by mGluR3 activation was extensively reported, the involvement of reduced cAMP levels in the effects of mGluR3 agonists and the association between cAMP decrease and the downstream pathways activated by mGluR3 remain neglected. Thus, we studied intracellular signaling mediating anti-apoptotic actions of mGluR3 in cultured rat astrocytes exposed to NO. In the present work, we showed that the cytoprotective effect of mGluR3 agonists (LY379268 and LY404039) requires both the reduction of intracellular cAMP levels and activation of Akt, as assessed by MTT and TUNEL techniques. Moreover, dibutyryl-cAMP impairs Akt phosphorylation induced by LY404039, indicating a relationship between mGluR3-reduced cAMP levels and PI3K/Akt pathway activation. We also demonstrated, by co-immunoprecipitation followed by western-blot, that the mGluR3 agonists not only induce per se survival-linked interaction between members of the NF-κB family p65 and c-Rel, but also impede reduction of levels of p65-c-Rel dimers caused by NO, suggesting a possible anti-apoptotic role for p65-c-Rel. All together, these data suggest that mGluR3 agonists may regulate cAMP/Akt/p65-c-Rel pathway, which would contribute to the protective effect of mGluR3 against NO challenge in astrocytes. Our results widen the knowledge about mechanisms of action of mGluR3, potential targets for the treatment of neurodegenerative disorders where a pathophysiological role for NO has been established