Publications by authors named "Hernando Perez"

Article Synopsis
  • Protein V in human adenovirus connects the inner capsid to the outer genome layer, playing a key role in the virus's structure.
  • When studying a variant without protein V (Ad5-ΔV), researchers found that these particles were softer and less brittle but were more likely to release pentons under mechanical stress.
  • The absence of protein V caused the core components to be more condensed and less likely to diffuse out during disruption, indicating that protein V helps maintain the structural integrity and facilitates genome release during the virus's entry into host cells.
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Colorectal cancer (CRC) is associated with mutations in APC/Wnt leading to c-myc activation and the overexpression of ODC1, the limiting step in polyamine synthesis. CRC cells also display a remodeling of intracellular Ca homeostasis that contributes to cancer hallmarks. As polyamines may modulate Ca homeostasis during epithelial tissue repair, we investigated whether polyamine synthesis inhibition may reverse Ca remodeling in CRC cells and, if so, the molecular basis for this reversal.

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Studies of virus adsorption on surfaces with optimized properties have attracted a lot of interest, mainly due to the influence of the surface in the retention, orientation and stability of the viral capsids. Besides, viruses in whole or in parts can be used as cages or vectors in different areas, such as biomedicine and materials science. A key requirement for virus nanocage application is their physical properties, i.

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The COVID-19 pandemic has provided an ultimate testing ground for evaluating the resilience and effectiveness of federal and decentralized systems. The article analyses how the Spanish asymmetrical system of decentralization has responded to the pandemic, focusing on the management developed by the sub-central governments (Autonomous Communities) during the first two waves of the pandemic in 2020. The research, which is both quantitative and qualitative, employs multidisciplinary tools and information sources, analyzing and linking fiscal and budgetary sources with the available statistics and information on health.

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Using new and original nineteenth-century sources, we analysed the epidemiology, clinical features and virology of the 1889 pandemic, which was referred to at the time as 'Russian flu' or 'Asiatic flu'. However, we rejected this identification of the disease as an 'influenza', which we believe to have been based on insufficient knowledge of the causative agent and instead posit that the pandemic was caused by a coronavirus. We provide a new account of the 1889-1893 pandemic, with a more detailed chronology that included at least four epidemiological waves.

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The molecular basis of amyloid toxicity in Alzheimer's disease (AD) remains controversial. Amyloid β (Aβ) oligomers promote Ca influx, mitochondrial Ca overload and apoptosis in hippocampal neurons in vivo and in vitro, but the primary Ca entry pathways are unclear. We studied Ca entry pathways induced by Aβ oligomers in rat hippocampal and cerebellar neurons.

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The adenovirus (AdV) icosahedral capsid encloses a nucleoprotein core formed by the dsDNA genome bound to numerous copies of virus-encoded, positively charged proteins. For an efficient delivery of its genome, AdV must undergo a cascade of dismantling events from the plasma membrane to the nuclear pore. Throughout this uncoating process, the virion moves across potentially disruptive environments whose influence in particle stability is poorly understood.

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Brain tumors comprise a large series of tumor cancer from benign to highly malignant gliomas and metastases from primary tumors outside the brain. Intracellular Ca homeostasis is involved in a large series of cell functions including cell proliferation, migration, and cell death. Store-operated Ca entry (SOCE), the most important Ca entry pathway in non-excitable cells, is involved in cell proliferation and migration and enhanced in tumor cells from breast cancer, colon cancer and cell lines derived from glioblastoma but there are almost no studies in human primary glioblastoma cells or other brain tumors.

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Enteric adenoviruses, one of the main causes of viral gastroenteritis in the world, must withstand the harsh conditions found in the gut. This requirement suggests that capsid stability must be different from that of other adenoviruses. We report the 4-Å-resolution structure of a human enteric adenovirus, HAdV-F41, and compare it with that of other adenoviruses with respiratory (HAdV-C5) and ocular (HAdV-D26) tropisms.

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Adenovirus minor coat protein VI contains a membrane-disrupting peptide that is inactive when VI is bound to hexon trimers. Protein VI must be released during entry to ensure endosome escape. Hexon:VI stoichiometry has been uncertain, and only fragments of VI have been identified in the virion structure.

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Aging is often associated with a cognitive decline and a susceptibility to neuronal damage. It is also the most important risk factor for neurodegenerative disorders, particularly Alzheimer's disease (AD). AD is related to an excess of neurotoxic oligomers of amyloid β peptide (Aβo); however, the molecular mechanisms are still highly controversial.

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The assembly of 3-dimensional covalent organic frameworks on the surface of carbon nanotubes is designed and successfully developed for the first time via the hybridization of imine-based covalent organic frameworks (COF-300) and oxidized MWCNTs by one-pot chemical synthesis. The resulting hybrid material ox-MWCNTs@COF exhibits a conformal structure that consists of a uniform amorphous COF layer covering the ox-MWCNT surface. The measurements of individual hybrid nanotube mechanical strength performed with atomic force microscopy provide insights into their stability and resistance.

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Some viruses package dsDNA together with large amounts of positively charged proteins, thought to help condense the genome inside the capsid with no evidence. Further, this role is not clear because these viruses have typically lower packing fractions than viruses encapsidating naked dsDNA. In addition, it has recently been shown that the major adenovirus condensing protein (polypeptide VII) is dispensable for genome encapsidation.

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Viruses undergo mesoscopic morphological changes as they interact with host interfaces and in response to chemical cues. The dynamics of these changes, over the entire temporal range relevant to virus processes, are unclear. Here, we report on creep compliance experiments on a small icosahedral virus under uniaxial constant stress.

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Alzheimer's disease (AD) is the most common neurodegenerative disorder and strongly associated to aging. AD has been related to excess of neurotoxic oligomers of amyloid β peptide (Aβo), loss of intracellular Ca homeostasis and mitochondrial damage. However, the intimate mechanisms underlying the pathology remain obscure.

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Store operated Ca entry (SOCE) is the most important Ca entry pathway in non-excitable cells. However, SOCE can also play a pivotal role in excitable cells such as anterior pituitary (AP) cells. The AP gland contains five different cell types that release six major AP hormones controlling most of the entire endocrine system.

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Microscopes are used to characterize small objects with the help of probes that interact with the specimen, such as photons and electrons in optical and electron microscopies, respectively. In atomic force microscopy (AFM) the probe is a nanometric tip located at the end of a micro cantilever which palpates the specimen under study as a blind person manages a walking stick. In this way AFM allows obtaining nanometric resolution images of individual protein shells, such as viruses, in liquid milieu.

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We use the nano-dissection capabilities of atomic force microscopy to induce structural alterations on individual virus capsids in liquid milieu. We fracture the protein shells either with single nanoindentations or by increasing the tip-sample interaction force in amplitude modulation dynamic mode. The normal behavior is that these cracks persist in time.

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While designing synthetic adhesives that perform in aqueous environments has proven challenging, microorganisms commonly produce bioadhesives that efficiently attach to a variety of substrates, including wet surfaces. The aquatic bacterium uses a discrete polysaccharide complex, the holdfast, to strongly attach to surfaces and resist flow. The holdfast is extremely versatile and has impressive adhesive strength.

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In Atomic Force Microscopy (AFM) the probe is a nanometric tip located at the end of a microcantilever which palpates the specimen under study as a blind person uses a white cane. In this way AFM allows obtaining nanometric resolution images of individual protein shells, such as viruses, in liquid milieu. Beyond imaging, AFM also enables the manipulation of single protein cages, and the characterization a variety physicochemical properties able of inducing any measurable mechanical perturbation to the microcantilever that holds the tip.

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A virus binding to a surface causes stress of the virus cage near the contact area. Here, we investigate the potential role of substrate-induced structural perturbation in the mechanical response of virus particles to adsorption. This is particularly relevant to the broad category of viruses stabilized by weak noncovalent interactions.

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Microscopes are used to characterize small objects with the help of probes that interact with the specimen, such as photons and electrons in optical and electron microscopies, respectively. In atomic force microscopy (AFM), the probe is a nanometric tip located at the end of a microcantilever which palpates the specimen under study just as a blind person manages a walking stick. In this way, AFM allows obtaining nanometric resolution images of individual protein shells, such as viruses, in a liquid milieu.

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Study Objectives: To describe a group of patients referred because of abnormal sleep behaviors that were suggestive of rapid eye movement (REM) sleep behavior disorder (RBD) in whom video-polysomnography ruled out RBD and showed the reported behaviors associated with vigorous periodic limb movements during sleep (PLMS).

Aims And Methods: Clinical history and video-polysomnography review of patients identified during routine visits in a sleep center.

Results: Patients were 15 men and 2 women with a median age of 66 (range: 48-77) years.

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It has been just over 100 years since inventor Joseph Coyle perfected the egg carton-a package format that has known very little changes since its first appearance ( Dhillon , S. B. C.

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Viral capsids are metastable structures that perform many essential processes; they also act as robust cages during the extracellular phase. Viruses can use multifunctional proteins to optimize resources (e.g.

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