424 research outputs found

    Interactions between endothelial cells and HIV-1.

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    Endothelial cells (EC) participate in inflammatory and immune reactions by producing and responding to soluble mediators. Human immunodeficiency virus (HIV)-1 profoundly alters the features of EC. In some anatomical districts, they are infected by the virus and may represent a relevant reservoir. During lymphomononuclear cell diapedesis, EC activate virus replication in crossing cells. Direct or indirect damage of EC is particularly relevant in central nervous system, where blood-brain barrier perturbation is pivotal in neuronal degeneration. The observed alterations of EC adhesive properties contribute in altered leukocyte traffic from blood to lymphoid organs and tissues and play a role in the onset of immune surveillance alteration. These alterations of EC functions are relevant for the general vasculopathy, which marks the acquired immunodeficiency syndrome, and in particular are instrumental in the pathogenesis of Kaposi's sarcoma. Here we discuss the biological and molecular activation of EC in HIV-1 infection that represents the basis to understand the pathogenesis of HIV-1 associated vascular diseases

    Integrins: A flexible platform for endothelial vascular tyrosine kinase receptors.

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    Compared to lower metazoans, vertebrates built up an exclusively new set of adhesion-related genes involved in the tissue development and in their functions. They include a large variety of extracellular matrix proteins and their heterodimeric integrin adhesive receptors. Integrins control the adhesive state of the cell through complex molecular mechanisms. Outside-in signalling informs the cell about the extracellular matrix environment, while Inside-out signalling results in changes in integrin functional activity. In the last 10 years it has well established a reciprocal integration of signals originating from integrins and receptors for soluble growth factors. This review summarizes the current understanding of this connection in vascular endothelial cells and highlights how integrins regulate a genetic program triggered by angiogenic inducers during embryo development and in adult life

    Int J Tuberc Lung Dis

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    BackgroundTherapeutic effects of antiretroviral therapy (ART) in patients with multidrug resistant tuberculosis (MDR-TB) and HIV infection have not been established.ObjectiveThe objective of this study was to assess therapeutic outcomes of ART integration with MDR-TB treatment.DesignA subgroup of MDR-TB patients from the SAPiT study, a randomized controlled trial, conducted in an out-patient clinic in Durban, South Africa from 2008\u20132012MethodsClinical outcomes at 18 months were compared in patients randomized to receive ART within 12 weeks of standard first-line tuberculosis treatment initiation with those who commenced ART after completing tuberculosis treatment.ResultsMycobacterium tuberculosis drug susceptibility was available in 489 (76%) of 642 SAPiT patients; 23 had MDR-TB, 14 in the integrated treatment arm and 9 in the sequential treatment arm. At 18 months, the mortality rate was 11.9/100 person-years (95% confidence interval (CI): 1.4\u201342.8) in the combined integrated treatment arm and 56.0/100 person-years (95%CI: 18.2\u2013130.8) in the sequential treatment arm, (Hazard Ratio adjusted for baseline CD4 count and whether MDR-TB treatment was initiated: 0.14; 95% CI: 0.02\u20130.94; P=0.04).ConclusionDespite the small sample size, the 86% reduction in mortality due to early initiation of ART in MDR-TB patients was statistically significant.D43TW00231/TW/FIC NIH HHS/United StatesD43 TW000231/TW/FIC NIH HHS/United States5U26PS001350/PS/NCHHSTP CDC HHS/United StatesU19 AI051794/AI/NIAID NIH HHS/United StatesU2G PS001350/PS/NCHHSTP CDC HHS/United StatesPEPFAR/United States2016-02-29T00:00:00Z24429305PMC47700138583vault:1580

    Three cases of cutaneous myiasis caused by Cordylobia rodhaini

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    Cordylobia sp. is a fly belonging to the Calliphoridae family. Three species of Cordylobia are known: C. anthropophaga, C. rodhaini and C. ruandae. The C. rodhaini Gedoelst 1909 lives in Sub-Saharan Africa, especially in rain forest areas. Usual hosts are rodents and antelopes. Humans are accidentally infested. Myiasis caused by C. rodhaini has been very rarely reported in the literature. We present three cases of C. rodhaini myiasis acquired in Ethiopia and Uganda

    Nutraceutical-Based Nanoformulations for Breast and Ovarian Cancer Treatment

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    Different strategies have been investigated for a more satisfactory treatment of advanced breast cancer, including the adjuvant use of omega-3 polyunsaturated fatty acids (PUFAs). These nutritional compounds have been shown to possess potent anti-inflammatory and antiangiogenic activities, the capacity to affect transduction pathways/receptors involved in cell growth and to reprogram tumor microenvironment. Omega-3 PUFA-containing nanoformulations designed for drug delivery in breast cancer were shown to potentiate the effects of enclosed drugs, enhance drug delivery to target sites, and minimize drug-induced side effects. We have critically analyzed here the results of the most recent studies investigating the effects of omega-3 PUFA-containing nanoformulations in breast cancer. The anti-neoplastic efficacy of omega-3 PUFAs has also been convincingly demonstrated by using preclinical in vivo models of ovarian cancer. The results obtained are critically analyzed here and seem to provide a sufficient rationale to move to still lacking interventional clinical trials, as well as to evaluate possible advantages of enclosing omega-3 PUFAs to drug-delivery nanosystems for ovarian cancer. Future perspectives in this area are also provided

    Percolation, Morphogenesis, and Burgers Dynamics in Blood Vessels Formation

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    Experiments of in vitro formation of blood vessels show that cells randomly spread on a gel matrix autonomously organize to form a connected vascular network. We propose a simple model which reproduces many features of the biological system. We show that both the model and the real system exhibit a fractal behavior at small scales, due to the process of migration and dynamical aggregation, followed at large scale by a random percolation behavior due to the coalescence of aggregates. The results are in good agreement with the analysis performed on the experimental data.Comment: 4 pages, 11 eps figure

    The GTPase-activating protein RN-tre controls focal adhesion turnover and cell migration.

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    SummaryBackgroundIntegrin-mediated adhesion of cells to the extracellular matrix (ECM) relies on the dynamic formation of focal adhesions (FAs), which are biochemical and mechanosensitive platforms composed of a large variety of cytosolic and transmembrane proteins. During migration, there is a constant turnover of ECM contacts that initially form as nascent adhesions at the leading edge, mature into FAs as actomyosin tension builds up, and are then disassembled at the cell rear, thus allowing for cell detachment. Although the mechanisms of FA assembly have largely been defined, the molecular circuitry that regulates their disassembly still remains elusive.ResultsHere, we show that RN-tre, a GTPase-activating protein (GAP) for Rabs including Rab5 and Rab43, is a novel regulator of FA dynamics and cell migration. RN-tre localizes to FAs and to a pool of Rab5-positive vesicles mainly associated with FAs undergoing rapid remodeling. We found that RN-tre inhibits endocytosis of β1, but not β3, integrins and delays the turnover of FAs, ultimately impairing β1-dependent, but not β3-dependent, chemotactic cell migration. All of these effects are mediated by its GAP activity and rely on Rab5.ConclusionsOur findings identify RN-tre as the Rab5-GAP that spatiotemporally controls FA remodeling during chemotactic cell migration

    seasonal abundance of the nearctic gall midge obolodiplosis robiniae in italy and the impact of its antagonist platygaster robiniae on pest populations

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    The Nearctic gall midge Obolodiplosis robiniae (Haldeman, 1847) (Diptera Cecidomyiidae) infesting black locusts, Robinia pseudoacacia L. (Fabaceae), was detected in Asia in 2002 and in Europe (first in Italy) in 2003. Its distribution in Europe has expanded dramatically, probably favored by extensive distribution of its host plant along the main routes. The results of a 3-yr study on the seasonal abundance of O. robiniae in northern Italy are reported here. O. robiniae can develop three to four generations per year by exploiting plants of different ages and vigor. Overwintering takes place as diapausing larvae and adults emerge in spring. Two generations are completed on mature plants where populations decline in summer. Two additional generations can develop on root suckers from midsummer onward. Pest population densities reach their highest levels in late spring. Gall midge larvae were attacked by various predators, but parasitism by the platygastrid Platygaster robiniae Buhl & Duso was particularly significant. The impact of parasitism by P. robiniae is indicated as a key factor in reducing O. robiniae population densities

    New insights on the effects of dietary omega‐3 fatty acids on impaired skin healing in diabetes and chronic venous leg ulcers

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    Long‐chain Omega‐3 polyunsaturated fatty acids (Omega‐3 PUFAs) are widely recognized as powerful negative regulators of acute inflammation. However, the precise role exerted by these dietary compounds during the healing process is still largely unknown, and there is increasing interest in understanding their specific effects on the implicated cells/molecular factors. Particular attention is being focused also on their potential clinical application in chronic pathologies characterized by delayed and impaired healing, such as diabetes and vascular diseases in lower limbs. On these bases, we firstly summarized the current knowledge on wound healing (WH) in skin, both in normal conditions and in the setting of these two pathologies, with particular attention to the cellular and molecular mechanisms involved. Then, we critically reviewed the outcomes of recent research papers investigating the activity exerted by Omega‐3 PUFAs and their bioactive metabolites in the regulation of WH in patients with diabetes or venous insufficiency and showing chronic recalcitrant ulcers. We especially focused on recent studies investigating the mechanisms through which these compounds may act. Considerations on the optimal dietary doses are also reported, and, finally, possible future perspectives in this area are suggested

    A multiscale hybrid model for pro-angiogenic calcium signals in a vascular endothelial cell

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    Cytosolic calcium machinery is one of the principal signaling mechanisms by which endothelial cells (ECs) respond to external stimuli during several biological processes, including vascular progression in both physiological and pathological conditions. Low concentrations of angiogenic factors (such as VEGF) activate in fact complex pathways involving, among others, second messengers arachidonic acid (AA) and nitric oxide (NO), which in turn control the activity of plasma membrane calcium channels. The subsequent increase in the intracellular level of the ion regulates fundamental biophysical properties of ECs (such as elasticity, intrinsic motility, and chemical strength), enhancing their migratory capacity. Previously, a number of continuous models have represented cytosolic calcium dynamics, while EC migration in angiogenesis has been separately approached with discrete, lattice-based techniques. These two components are here integrated and interfaced to provide a multiscale and hybrid Cellular Potts Model (CPM), where the phenomenology of a motile EC is realistically mediated by its calcium-dependent subcellular events. The model, based on a realistic 3-D cell morphology with a nuclear and a cytosolic region, is set with known biochemical and electrophysiological data. In particular, the resulting simulations are able to reproduce and describe the polarization process, typical of stimulated vascular cells, in various experimental conditions.Moreover, by analyzing the mutual interactions between multilevel biochemical and biomechanical aspects, our study investigates ways to inhibit cell migration: such strategies have in fact the potential to result in pharmacological interventions useful to disrupt malignant vascular progressio
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