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Mitochondrial dysfunction as a target in spinal cord inj.ry:intimate correlation between pathological processes and therapeutic approaches

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Neural Regeneration Research 2023年第10期18卷 2161-2166页

作者： j.lieta Schmidt héctor Ramiro Quintá Universidad de Buenos Aires CABAArgentina Laboratorio de Medicina Experimental“Dr.j.Toblli” Hospital AlemánCABAArgentina Consej. Nacional de Investigaciones Científicas y Técnicas-CONICET CABAArgentina Rehabilitation Medicine Department University of MinnesotaTwin CitiesMINUSA

Traumatic spinal cord inj.ries interrupt the connection of all axonal proj.ctions with their neuronal targets below and above the lesion site. This interruption results in either temporary or permanent alterations in the locomotor, sensory, and autonomic functions. Damage in the spinal tissue prevents the re-growth of severed axons across the lesion and their reconnection with neuronal targets. Therefore, the absence of spontaneous repair leads to sustained impairment in voluntary control of movement below the inj.ry. For decades, axonal regeneration and reconnection have been considered the opitome of spinal cord inj.ry repair with the goal being the repair of the damaged long motor and sensory tracts in a complex process that involves:(1) resealing inj.red axons;(2) reconstructing the cytoskeletal structure inside axons;(3) re-establishing healthy growth cones;and(4) assembling axonal cargos. These biological processes require an efficient production of adenosine triphosphate, which is affected by mitochondrial dysfunction after spinal cord inj.ry. From a pathological standpoint, during the secondary stage of spinal cord inj.ry, mitochondrial homeostasis is disrupted, mainly in the distal segments of severed axons. This result in a reduction of adenosine triphosphate levels and subsequent inactivation of adenosine triphosphate-dependent ion pumps required for the regulation of ion concentrations and reuptake of neurotransmitters, such as glutamate. The consequences are calcium overload, reactive oxygen species formation, and excitotoxicity. These events are intimately related to the activation of necrotic and apoptotic cell death programs, and further exacerbate the secondary stage of the inj.ry, being a hallmark of spinal cord inj.ry. This is why restoring mitochondrial function during the early stage of secondary inj.ry could represent a potentially effective therapeutic intervention to overcome the motor and sensory failure produced by spinal cord inj.ry. This

关键词： adenosine triphosphate axonal regeneration creatine mitochondria dysfunction mitochondria spinal cord inj.ry

Multi-obj.ctive optimization design of bridge piers with hybrid heuristic algorithms

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j.urnal of Zhej.ang University-Science A(Applied Physics & Engineering) 2012年第6期13卷 420-432页

作者： Francisco j. MARTINEZ-MARTIN Fernando GONZALEZ-VIDOSA Antonio hOSPITALER Víctor YEPES Department of Geotechnical Engineering Universitat Politècnica de València 46022 Valencia Spain Department of Construction Engineering ICITECH Universitat Politècnica de València 46022 Valencia Spain

This paper describes one approach to the design of reinforced concrete (RC) bridge piers, using a three-hybrid multi- obj.ctive simulated annealing (SA) algorithm with a neighborhood move based on the mutation operator from the genetic algorithms (GAs), namely MOSAMO1, MOSAMO2 and MOSAMO3. The procedure is applied to three obj.ctive functions: the economic cost, the reinforcing steel congestion and the embedded CO 2 emissions. Additional results for a random walk and a descent local search multi-obj.ctive algorithm are presented. The evaluation of solutions follows the Spanish Code for structural concrete. The methodology was applied to a typical bridge pier of 23.97 m in height. This example involved 110 design variables. Results indicate that algorithm MOSAMO2 outperforms other algorithms regarding the definition of Pareto fronts. Further, the proposed procedure will help structural engineers to enhance their bridge pier designs.

关键词： Bridge piers Concrete structures Multi-obj.ctive optimization Simulated annealing (SA) Structural design

Arrhythmogenic mechanisms in ryanodine receptor channelopathies

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Science China(Life Sciences) 2015年第1期58卷 54-58页

作者： ZhAO Yan-Ting VALDIVIA Carmen R. GURROLA Georgina B. hERNNDEZ j.nathan j. VALDIVIA héctor h. Center for Arrhythmia Research Department of Internal MedicineCardiovascular DivisionUniversity of Michigan

Ryanodine receptors(Ry Rs) are the calcium release channels of sarcoplasmic reticulum(SR) that provide the maj.rity of calcium ions(Ca2+) necessary to induce contraction of cardiac and skeletal muscle *** their intracellular environment,Ry R channels are regulated by a variety of cytosolic and luminal factors so that their output signal(Ca2+) induces finely-graded cell contraction without igniting cellular processes that may lead to aberrant electrical activity(ventricular arrhythmias) or cellular *** importance of Ry R dysfunction has been recently highlighted with the demonstration that point mutations in RYR2,the gene encoding for the cardiac isoform of the Ry R(Ry R2),are associated with catecholaminergic polymorphic ventricular tachycardia(CPVT),an arrhythmogenic syndrome characterized by the development of adrenergically-mediated ventricular tachycardia in individuals with an apparently normal *** we summarize the state of the field in regards to the main arrhythmogenic mechanisms triggered by Ry R2 channels harboring mutations linked to *** CPVT mutations characterized to date endow Ry R2 channels with a gain of function,resulting in hyperactive channels that release Ca2+ spontaneously,especially during *** spontaneous Ca2+ release is extruded by the electrogenic Na+/Ca2+ exchanger,which depolarizes the external membrane(delayed afterdepolarization or DAD) and may trigger untimely action ***,a rare set of CPVT mutations yield Ry R2 channels that are intrinsically hypo-active and hypo-responsive to stimuli,and it is unclear whether these channels release Ca2+ spontaneously during *** discuss novel cellular mechanisms that appear more suitable to explain ventricular arrhythmias due to Ry R2 loss-of-function mutations.

关键词： ryanodine receptors CPVT sarcoplasmic reticulum cardiac arrhythmias

Isolation, Cultivation, and Morphological Characteristics of hair Follicle Adult Stem Cells in the Bulge Region in Mouse and human

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Microscopy Research 2020年第2期8卷 9-30页

作者： Bélgica j. Molina héctor j. Finol Center for Electron Microscopy Science Faculty Central University of Venezuela Caracas Venezuela Dermatology Service University Hospital of Caracas Caracas Venezuela

Skin contains various populations of stem cells (SCs). Among these are hair follicle stem cells (hFSCs) in the bulge region. The behavior of hFSCs deserves to be widely studied due to the benefits to be derived from their identification, isolation, and amplification. Skin samples of newborn mice (n = 32) and human adults (n = 10) were used, and the bulge region was isolated and cultured. The isolation and characterization of cells were conducted through immunocytochemistry and immunofluorescence, using mainly CD34 and CD200 monoclonal antibodies. Initially, cells grew slowly from the explant around the bulge region, accruing cells with different morphology in both mouse and human, latter being mostly polygonal;the mouse cells reaching confluence faster (5 to 7 days) than the human (12 to 15 days). It was possible to isolate into subcultures cells with small size (10 - 13 μm diameter), round-shape, scant cytoplasm, central prominent nucleus and with nucleolus, which formed colonies, maintaining their phenotype in a high proportion (77% - 83% and 91% in mouse and human, respectively), without showing changes in their morphology during almost 7 months in the mouse cells, and a month and a half in the human. These results demonstrate that the selection, the isolation, and the conditioned mediums allowed population increases of bulge cells and indicate that cultured cells may retain their sternness in that they maintained their phenotypic characteristics, expressed specific markers for SCs, and showed a high proliferative capacity for long periods. hair follicles, in mice and humans, are important repositories of multipotent stem cells, due to their tendency to differentiate into keratinocytes. human hFSCs, obtained by depilation, preserve their potential for proliferation and prove to be easily accessible. This suggests that the bulge cells may present an alternative source of autologous stem cells for tissue engineering and regenerative medicine.

关键词： Stem Cells hair Follicle Bulge Niche Alopecia

Identification of Bulge Stem Cells in Mouse and human hair Follicles

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Microscopy Research 2018年第3期6卷 19-29页

作者： Bélgica j. Molina Elda Giansante héctor j. Finol Center of Electron Microscopy Science Faculty Central University of Venezuela Caracas Venezuela Dermatology Service University hospital of Caracas Caracas Venezuela

The skin contains various populaions of stem cells, but its characterization has been hampered by lack of markers and unclear location. The hair follicle has a niche for stem cells called a “bulge” which acts as a reservoir of multipotent stem cells. In the study reported here, an immunohistochemical and immunofluorescence analysis was performed on mouse and human tissues in order to determine the possible presence of stem cells of hair follicle through cytokeratin 15 (CK15), CD34, and CD200 markers identified as crucial to the stem cells and to identify the bulge region. Mouse (n = 7) and human (n = 7) skin samples were used. The expression of proteins was determined by the indirect immunoperoxidase technique and a secondary antibody bound to a fluorochrome. The specificity of staining was evaluated by negative controls. The results revealed that the stem cells associated with CD34 and CD200 antibodies were differentially expressed in the interfollicular epidermis, sebaceous glands, and bulge region, indicating that, in mice, CD34 and, in humans, CD200 are more specific than CK15 in detecting bulge cells. It also suggests that CD34 is specific for mouse bulge cells, while CD200 might have specificity for progenitor cells and partially differentiated cells in humans.

关键词： Stem Cells hair Follicle Bulge CD34 CD200

Variable exponent hardy spaces associated with discrete Laplacians on graphs

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Science China Mathematics 2019年第1期62卷 73-124页

作者： Víctor Almeida j.rge j.Betancor Alej.NDro j.Castro Lourdes Rodríguez-Mesa Departamento de Análisis Matemático Universidad de La Laguna Department of Mathematics Nazarbayev University

In this paper we develop the theory of variable exponent hardy spaces associated with discrete Laplacians on infinite graphs. Our hardy spaces are defined by square integrals, atomic and molecular decompositions. Also we study boundedness properties of Littlewood-Paley functions, Riesz transforms, and spectral multipliers for discrete Laplacians on variable exponent hardy spaces.

关键词： graphs discrete Laplacian hardy spaces variable exponent square functions spectral multipliers

Population dynamics of three lizard species from the genus Sceloporus:short-term changes in demographic parameters

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Integrative Zoology 2019年第6期14卷 542-560页

作者： Selene VARGAS-GARCÍA Víctor ARGAEZ Israel SOLANO-ZAVALETA j.j.ime ZÚÑIGA-VEGA Graduate Program in Biological Sciences National Autonomous University of MexicoUniversity CityMexico CityMéxico Department of Ecology and Natural Resources Faculty of SciencesNational Autonomous University of MexicoUniversity CityMexico CityMéxico.

Most demographic studies focus on numerical changes that occur within populations across ***,typically studies at an interannual scale do not provide information on the particular times of the year(particular months or seasons)when rates of survival,recruitment,or migration increase or decrease due to physiological,behavioral or ecological *** monthly or seasonal changes in demographic parameters may lead to substantial variations in population *** this study,we collected capture-mark-recapture data on 3 species of lizards of the genus Sceloporus(Sceloporus torquatus,Sceloporus grammicus and Sceloporus megalepidurus)found in ecologically similar habitats to examine potential changes in demographic rates among 3 different climatic seasons:rainy,cold-dry and warm-dry *** tested different hypotheses about the effect of these seasons on survival,recruitment of new adults,and temporary *** found that during the season with severe thermal constraints,the cold-dry season,survival of *** decreased *** also detected a considerable increase in the recruitment rate of *** during the rainy season,when these lizards are establishing territories and finding *** contrast,we found no evidence of intra-annual changes in the rate of temporary *** addition,we calculated abundance and population growth rates for each species and for each *** study represents a significant contribution to the understanding of intra-annual demographic variation in lizards.

关键词： abundance recruitment Sceloporus lizards survival temporary emigration

A novel E153X point mutation in the androgen receptor gene in a patient with complete androgen insensitivity syndrome

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Asian j.urnal of Andrology 1999年第1期1卷 73-77页

作者： Silvia B Copelli Serge Lumbroso Francoise Audran Eliana h Pellizzari j.an j.heinrich Selva B Cigorraga Charles Sultan héctor E Chemes Laboratore d'hormonologie Hopital Lapeyronie et INSER U 439 Pathologie des recepteurs nucleaires.Unite d'Endocrinologie et Gynecologie PediatriquesHopital A.de VillenetiveMontpellier-France CEDIE-CONICET Division de EndocrinologtaHospital de Niflos"Ricardo Gutierrez"Buenos AiresArgentina

Aim:To study a 46,XY newborn patient with a phenotype suggestive of an androgen insensitivity syndrome toconfirn an anomaly in the AR ***:Genomic DNA from leukocytes was isolated in order to analyze SRYgene by PCR and sequencing of the eight exons of AR *** of human Leydig cell mesenchymal precursorsfrom the testis was performed in order to study testosterone production and response to hCG stimulation in ***:Surgical exploration disclosed two testes,no Wolffian structures and important Mullerian *** gene was present in peripheral blood *** of the AR gene evidenced a previously unreported Gto T transversion in exon 1 that changed the normal glutamine 153 codon to a stop *** cell culturesproduced sizable amounts of testosterone and were responsive to hCG ***:This E153X nonsensepoint mutation has not been described previously in cases of AIS,and could lead to the synthesis of a short truncated(153 vs 919 residues)non functional AR probably responsible for the phenotype of complete androgen insensitivitysyndrome(CAIS).

关键词： testicular feminization androgen receptor point mutation Mullerian ducts

Ultrastructural Aspects of Apoptosis in Systemic Sclerosis Inflammatory Myopathy

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Microscopy Research 2018年第1期6卷 1-7页

作者： héctor j. Finol héctor Luis Osorio-Vega Radharani Dorta-Ledezma Antonio Roschman-González Blanca Muller Israel Montes de Oca Center for Electron Microscopy Sciences Faculty Caracas Venezuela Laboratory of Cellular and Molecular Pathology Center for Experimental Medicine Venezuelan Institute for Scientific Research Miranda Venezuela Dentistry Faculty Central University of Venezuela Caracas Venezuela Medicine Service No. 2 Caracas University Hospital Caracas Venezuela

Muscle biopsies from two female patients with systemic sclerosis (SS) and an inflammatory myopathy were studied ultrastructurally in relation to the possible presence of apoptosis in skeletal muscle fibers. Undergoing apoptosis showed characteristic morphological features of this process, including chromatin aggregation as well as nuclear and sarcoplasmic partition into membrane bound-vacuoles (apoptotic bodies) which contained autophagosomes, mitochondria, isolated myofilaments and nuclear material. Vacuoles exhibited different diameters and were covered by single membranes, appearing beneath basement membrane. Apoptosis occurred in some fiber segments as in necrosis or included whole atrophied fibers. These results indicate that apoptosis coexists with necrosis in the inflammatory myopathy of SS.

关键词： Apoptosis Skeletal Muscle Fiber Systemic Sclerosis Inflammatory Myopathy Ultrastructure