RESUMO
INTRODUCTION: Social Media (SoMe) offers excellent opportunities for scientific knowledge dissemination and its use has been extended in urology. However, there is controversy about its use. Live videos shared trough SoMe platforms offer many advantages, but at the same time disadvantages and potential risks including confidentiality, copyright infringement, among others. We aimed to assess the activity of shared videos on SoMe during urological conferences. MATERIALS AND METHODS: A comprehensive study of videos shared on SoMe during European Association of Urology congress was carried out from January 2016 to June 2018. The online tools Symplur (Symplur.com), Twitter, Periscope and YouTube were searched to collect data. Number of videos, transmission time and views were analyzed. Videos were classified as live or pre-recorded and as scientific or non-scientific. SPSS V22.0 was used to process data. RESULTS: We identified 108 videos shared on SoMe, 292.42minutes of transmission, 67732 views. 79 of 108 (73%) were live streaming videos, 78 (72%) of which were considered scientific vs. 30 (28%) non-scientific. An increase was observed trough the years of study (2016-2018) in transmission time (p=.031) number of videos, views (p=.018) and live videos (p=.019) during the annual congress of the European Association of Urology. CONCLUSIONS: Shared videos on SoMe from urological conferences are increasing. These provide advantages for communication, scientific dissemination and expand the scope of conferences. However, there is potential risk of sharing information in real time; that could not be in line with the recommendations for appropriate use of social networks.
Assuntos
Congressos como Assunto/estatística & dados numéricos , Disseminação de Informação/métodos , Mídias Sociais/estatística & dados numéricos , Urologia/estatística & dados numéricos , Gravação em Vídeo/estatística & dados numéricos , Autoria , Confidencialidade , Europa (Continente) , Humanos , Propriedade Intelectual , Aplicativos Móveis/estatística & dados numéricos , Fatores de Tempo , Gravação em Vídeo/classificaçãoRESUMO
Functional magnetic resonance imaging (fMRI) is increasingly used in cognitive neuroscience and has become a valuable tool in the study of auditory processing in zebra finches, a well-established model of learned vocal communication. Due to its sensitivity to head motion, most fMRI studies in animals are performed in anaesthetized conditions, which might significantly impact neural activity evoked by stimuli and cognitive tasks. In this study, we (1) demonstrate the feasibility of fMRI in awake zebra finches and (2) explore how light anaesthesia regimes affect auditory-evoked BOLD responses to biologically relevant songs. After an acclimation procedure, we show that fMRI can be successfully performed during wakefulness, enabling the detection of reproducible BOLD responses to sound. Additionally, two light anaesthesia protocols were tested (isoflurane and a combination of medetomidine and isoflurane), of which isoflurane alone appeared to be the most promising given the high success rate, non-invasive induction, and quick recovery. By comparing auditory evoked BOLD responses in awake versus lightly anaesthetized conditions, we observed overall effects of anaesthetics on cerebrovascular reactivity as reflected in the extent of positive and negative BOLD responses. Further, our results indicate that light anaesthesia has limited effects on selective BOLD responses to natural versus synthetic sounds.
Assuntos
Anestésicos/farmacologia , Potenciais Evocados Auditivos/efeitos dos fármacos , Vigília/efeitos dos fármacos , Estimulação Acústica , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Mapeamento Encefálico , Tentilhões , Cabeça/fisiologia , Isoflurano/farmacologia , Imageamento por Ressonância Magnética , MasculinoRESUMO
Developmental control of bone tissue-specific genes requires positive and negative regulatory factors to accommodate physiological requirements for the expression or suppression of the encoded proteins. Osteocalcin (OC) gene transcription is restricted to the late stages of osteoblast differentiation. OC gene expression is suppressed in nonosseous cells and osteoprogenitor cells and during the early proliferative stages of bone cell differentiation. The rat OC promoter contains a homeodomain recognition motif within a highly conserved multipartite promoter element (OC box I) that contributes to tissue-specific transcription. In this study, we demonstrate that the CCAAT displacement protein (CDP), a transcription factor related to the cut homeodomain protein in Drosophila melanogaster, may regulate bone-specific gene transcription in immature proliferating osteoblasts. Using gel shift competition assays and DNase I footprinting, we show that CDP/cut recognizes two promoter elements (TATA and OC box I) of the bone-related rat OC gene. Overexpression of CDP/cut in ROS 17/2.8 osteosarcoma cells results in repression of OC promoter activity; this repression is abrogated by mutating OC box I. Gel shift immunoassays show that CDP/cut forms a proliferation-specific protein/DNA complex in conjunction with cyclin A and p107, a member of the retinoblastoma protein family of tumor suppressors. Our findings suggest that CDP/cut may represent an important component of a cell signaling mechanism that provides cross-talk between developmental and cell cycle-related transcriptional regulators to suppress bone tissue-specific genes during proliferative stages of osteoblast differentiation.
Assuntos
Ciclina A/metabolismo , Proteínas Nucleares/metabolismo , Osteocalcina/genética , Regiões Promotoras Genéticas , Proteínas Repressoras/metabolismo , Transcrição Gênica , Animais , Sequência de Bases , Sítios de Ligação , Diferenciação Celular , Ciclina A/isolamento & purificação , Drosophila melanogaster/genética , Proteínas de Homeodomínio/metabolismo , Dados de Sequência Molecular , Proteínas Nucleares/isolamento & purificação , Osteoblastos/citologia , Osteossarcoma , Ratos , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Repressoras/isolamento & purificação , Proteína do Retinoblastoma/metabolismo , TATA Box , Transfecção , Células Tumorais CultivadasRESUMO
Mitochondria are 'life-essential' organelles for the production of metabolic energy in the form of ATP. Paradoxically mitochondria also play a key role in controlling the pathways that lead to cell death. This latter role of mitochondria is more than just a 'loss of function' resulting in an energy deficit but is an active process involving different mitochondrial proteins. Cytochrome c was the first characterised mitochondrial factor shown to be released from the mitochondrial intermembrane space and to be actively implicated in apoptotic cell death. Since then, other mitochondrial proteins, such as AIF, Smac/DIABLO, endonuclease G and Omi/HtrA2, were found to undergo release during apoptosis and have been implicated in various aspects of the cell death process. Members of the Bcl-2 protein family control the integrity and response of mitochondria to apoptotic signals. The molecular mechanism by which mitochondrial intermembrane space proteins are released and the regulation of mitochondrial homeostasis by Bcl-2 proteins is still elusive. This review summarises and evaluates the current knowledge concerning the complex role of released mitochondrial proteins in the apoptotic process.
Assuntos
Apoptose/fisiologia , Células Eucarióticas/metabolismo , Membranas Intracelulares/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Transdução de Sinais/fisiologia , Animais , HumanosRESUMO
A crucial event in the process of apoptosis is caspase-dependent generation of truncated Bid (tBid), inducing release of cytochrome c. In an in vitro reconstitution system we combined purified recombinant tBid with isolated liver mitochondria and identified the released proteins using a proteomic matrix-assisted laser desorption ionization post-source decay (MALDI-PSD) approach. In order to meet physiological conditions, the concentration of tBid was chosen such that it was unable to induce cytochrome c release in mitochondria derived from liver-specific Bcl-2-transgenic mice. Several mitochondrial proteins were identified to be released in a tBid-dependent way, among which cytochrome c, DIABLO/Smac, adenylate kinase 2, acyl-CoA-binding protein, endonuclease G, polypyrimidine tract-binding protein, a type-I RNA helicase, a WD-40 repeat-containing protein and the serine protease Omi. Western blotting confirmed the absence of adenylate kinase 3, a matrix mitochondrial protein. These results demonstrate that a physiologically relevant concentration of tBid is sufficient to induce release of particular intermembrane mitochondrial proteins belonging to a broad molecular-mass range.
Assuntos
Apoptose/fisiologia , Proteínas de Transporte/farmacologia , Mitocôndrias Hepáticas/efeitos dos fármacos , Proteínas Mitocondriais/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Adenilato Quinase/análise , Adenilato Quinase/metabolismo , Animais , Proteínas Reguladoras de Apoptose , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3 , Proteínas de Transporte/análise , Proteínas de Transporte/metabolismo , Grupo dos Citocromos c/análise , Grupo dos Citocromos c/metabolismo , Inibidor da Ligação a Diazepam/análise , Endodesoxirribonucleases/análise , Endodesoxirribonucleases/metabolismo , Serina Peptidase 2 de Requerimento de Alta Temperatura A , Isoenzimas/análise , Isoenzimas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias Hepáticas/metabolismo , Proteínas Mitocondriais/análise , Proteína de Ligação a Regiões Ricas em Polipirimidinas , Proteínas de Ligação a RNA/análise , Proteínas de Ligação a RNA/metabolismo , Proteínas Recombinantes/farmacologia , Ribonucleoproteínas/análise , Ribonucleoproteínas/metabolismo , Serina Endopeptidases/análise , Serina Endopeptidases/metabolismoRESUMO
Proteome analysis of supernatant of isolated mitochondria exposed to recombinant tBid, a proapoptotic Bcl-2 member, revealed the presence of the serine protease Omi, also called HtrA2. This release was prevented in mitochondria derived from Bcl-2-transgenic mice. Release of Omi under apoptotic conditions was confirmed in vivo in livers from mice injected with agonistic anti-Fas antibodies and was prevented in livers from Bcl-2 transgenic mice. Omi release also occurs in apoptotic dying but not in necrotic dying fibrosarcoma L929 cells, treated with anti-Fas antibodies and TNF, respectively. The amino acid sequence reveals the presence of an XIAP interaction motif at the N-terminus of mature Omi. We demonstrate an interaction between endogeneous Omi and recombinant XIAP. Furthermore we show that endogenous Omi is involved in enhanced activation of caspases in cytosolic extracts.
Assuntos
Apoptose/fisiologia , Caspases/metabolismo , Mitocôndrias/metabolismo , Proteínas/metabolismo , Serina Endopeptidases/metabolismo , Sequência de Aminoácidos , Animais , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3 , Proteínas de Transporte/farmacologia , Células Cultivadas , Citosol/metabolismo , Ativação Enzimática , Serina Peptidase 2 de Requerimento de Alta Temperatura A , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Mitocondriais , Dados de Sequência Molecular , Translocação Genética/efeitos dos fármacos , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo XRESUMO
A hallmark of apoptosis is the fragmentation of nuclear DNA. Although this activity involves the caspase-3-dependent DNAse CAD (caspase-activated DNAse), evidence exists that DNA fragmentation can occur independently of caspase activity. Here we report on the ability of truncated Bid (tBid) to induce the release of a DNAse activity from mitochondria. This DNAse activity was identified by mass spectrometry as endonuclease G, an abundant 30 kDa protein released from mitochondria under apoptotic conditions. No tBid-induced endonuclease G release could be observed in mitochondria from Bcl-2-transgenic mice. The in vivo occurrence of endonuclease G release from mitochondria during apoptosis was confirmed in the liver from mice injected with agonistic anti-Fas antibody and is completely prevented in Bcl-2 transgenic mice. These data indicate that endonuclease G may be involved in CAD-independent DNA fragmentation during cell death pathways in which truncated Bid is generated.
Assuntos
Apoptose/fisiologia , Caspases/metabolismo , Fragmentação do DNA , Endodesoxirribonucleases/fisiologia , Proteínas Mitocondriais/fisiologia , Animais , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3 , Proteínas de Transporte/farmacologia , Grupo dos Citocromos c/metabolismo , Endodesoxirribonucleases/metabolismo , Genes bcl-2/fisiologia , Camundongos , Proteínas Mitocondriais/metabolismoRESUMO
OBJECTIVE: To determine the experience of the relatives of organ and tissue donors, immediately before, during and soon after the donation procedure. DESIGN: Questionnaire. METHOD: At two national one-day meetings at which about 10% of the families of donors between 1991 and 1998 were represented, the participants completed a questionnaire with questions about their appreciation of the communication with the different health care professionals. The appreciation was scored on a 7-point scale. RESULTS: Most relatives looked back with satisfaction on the events in the hospital and soon thereafter; the appreciation was 'a little satisfied' to 'satisfied'. The relatives in non-heart-beating kidney transplantation were more satisfied compared to those confronted with the brain death transplantation, with regard to the conversation in which the death was announced as well as to the conversation regarding the donation procedure. Relatives in 1998 were more positive about some specific aspects than in 1995, notably concerning explanation of the phenomenon of brain death. Satisfaction was primarily influenced by the way in which the news of death was conveyed and the aftercare by the transplant coordinator. The moment donation was addressed and the moment the relatives said 'good-bye' to their beloved were the next important factors.
Assuntos
Atitude do Pessoal de Saúde , Morte Encefálica , Família/psicologia , Transplante de Rim/psicologia , Doadores de Tecidos/psicologia , Feminino , Humanos , Masculino , Países Baixos , Estudos Retrospectivos , Inquéritos e QuestionáriosRESUMO
A discussion is presented of the problems involved in the interpretation of linear dichroism and fluorescence depolarization experiments on macroscopically ordered membrane systems. Particular attention has been paid to ordered membranes containing photosynthetic pigment-protein complexes, but the mathematical treatment can equally well be applied to other systems. The information about the orientational properties of the pigments is obtained by the application of the theories developed for the characterization of the molecular orientational order in liquid-crystalline materials. It is shown that while linear dichroism only yields the order parameter S mu of the absorption transition moment, fluorescence depolarization experiments yield in addition the order parameter Sv of the emission transition moment as well as three orientational correlation functions of the two transition moments. It is argued that in general the latter information can only be obtained on utilizing a number of experimental scattering geometries. In particular, the merits of angle-resolved experiments are illustrated.
Assuntos
Membrana Celular/metabolismo , Fotossíntese , Pigmentos Biológicos/metabolismo , Proteínas/metabolismo , Fenômenos Biofísicos , Biofísica , Polarização de Fluorescência , Matemática , ProbabilidadeRESUMO
A model consisting of a spring loaded by a time-dependent mass is presented simulating the vertical and longitudinal horizontal ground reaction force patterns obtained from the hindlimb of a walking horse.
Assuntos
Gravitação , Membro Posterior/fisiologia , Cavalos/fisiologia , Locomoção , Modelos Biológicos , Animais , Fenômenos Biomecânicos , MatemáticaRESUMO
We have used a new and relatively easy approach to study the pigment-organization in chlorosomes from the photosynthetic bacterium Chloroflexus aurantiacus and in B800-850 antenna complexes of the photosynthetic purple bacterium Rhodobacter sphaeroides. These particles were embedded in compressed and uncompressed gels and the polarized fluorescence was determined in a 90 degrees setup. Assuming both a rotational symmetric distribution of the particles in the gel and of the transition dipole moments in the particles, the order parameters
and
, describing the orientation of the symmetry axis of the particles with respect to the direction of gel expansion can be determined. Moreover, the direction parameters, describing the orientation of the absorption and emission dipole moments with respect to the symmetry axis of the particles can be obtained.The value of
is essential for quantitative interpretation of linear dichroism measurements and usually it is estimated from theoretical approaches, which may lead to incorrect results. For the rod-like chlorosomes the value of
appears to be the same as predicted by the theoretical approach of Ganago, A. O., M. V. Fok, I. A. Abdourakhmanov, A. A. Solov'ev, and Yu. E. Erokhin (1980. Mol. Biol. [Mosc.]. 14:381-389). The agreement with linear dichroism results, analyzed with this theoretical approach shows that the transition dipole moments are indeed in good approximation distributed in a rotationally symmetric way around the long axis of the chlorosomes. Moreover, it appears those BChl c molecules, which fluoresce, are oriented in the same way with respect to the symmetry axis as the rest of these pigments, with the dipole moments close to parallel to the long axis.The B800-850 complexes appear to orient like discs, whereas the transition dipoles of the BChl a 800- and 850-nm bands are oriented almost perpendicular to the symmetry axis. These findings are in agreement with the minimal model for these complexes proposed by Kramer, H. J. M., R. van Grondelle, C. N. Hunter, W. H. J. Westerhuis, and J. Amesz (1984. Biochim. Biophys. Acta. 156-165).The amount of orientation of the particles appears to vary for different gels and it is lower than predicted by the theory of Ganago et al., showing that application of their approach for these particles leads to incorrect interpretations.The approach that is used in this study allows determination of orientations of those dipole moments, which transfer their excitation energy to the fluorescing species, in contrast to linear dichroism measurements, where the orientations of all absorbing dipole moments are studied. For the polarized fluorescence measurements, the amount of orientation of the particles is determined experimentally, whereas for linear dichroism this amount has to be estimated from theoretical models. The value of
that can be determined from the fluorescence measurements can, however, also be used for a quantitative interpretation of the linear dichroism results.
RESUMO
A dynamic model is developed to describe the swing phase of the hindlimb of a normally walking horse. The limb was represented by four rigid segments constrained to move in a sagittal plane only. The mathematical equations of motion of this four-element pendulum were formulated using Lagrange's theorem. The morphometric parameters from the hindlimb segments of 3 horses were determined using high-speed film analysis. Five muscle groups were incorporated in the model. Muscle activity was derived from earlier EMG measurements. Optimization of muscle moments resulted in a simulated swing movement that approximated that in the living animal.
Assuntos
Membro Posterior/fisiologia , Cavalos/fisiologia , Locomoção , Modelos Biológicos , AnimaisRESUMO
Yersinia enterocolitica induces apoptosis in macrophages by injecting the plasmid-encoded YopP (YopJ in other Yersinia species). Recently it was reported that YopP/J is a member of an ubiquitin-like protein cysteine protease family and that the catalytic core of YopP/J is required for its inhibition of the MAPK and NF-kappaB pathways. Here we analyzed the YopP/J-induced apoptotic signaling pathway. YopP-mediated cell death could be inhibited by addition of the zVAD caspase inhibitor, but not by DEVD or YVAD. Generation of truncated Bid (tBid) was the first apoptosis-related event that we observed. The subsequent translocation of tBid to the mitochondria induced the release of cytochrome c, leading to the activation of procaspase-9 and the executioner procaspases-3 and -7. Inhibition of the postmitochondrial executioner caspases-3 and -7 did not affect Bid cleavage. Bid cleavage could not be observed in a yopP-deficient Y. enterocolitica strain, showing that this event requires YopP. Disruption of the catalytic core of YopP abolished the rapid generation of tBid, thereby hampering induction of apoptosis by Y. enterocolitica. This finding supports the idea that YopP/J induces apoptosis by directly acting on cell death pathways, rather than being the mere consequence of gene induction inhibition in combination with microbial stimulation of the macrophage.
Assuntos
Apoptose/fisiologia , Proteínas de Bactérias/fisiologia , Proteínas de Transporte/metabolismo , Macrófagos/citologia , Transdução de Sinais , Yersinia enterocolitica/metabolismo , Sequência de Aminoácidos , Animais , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3 , Sequência de Bases , Caspases/metabolismo , Domínio Catalítico , Linhagem Celular , Grupo dos Citocromos c/metabolismo , Primers do DNA , Ativação Enzimática , Hidrólise , Macrófagos/metabolismo , CamundongosRESUMO
Caspases are a family of heteromeric (p20/p10) cysteine proteases with important functions in the regulation of apoptosis and inflammation. Up to now, tools to identify new substrates for caspases have mostly been limited to the random screening of in vitro translated proteins that are known, or assumed, to play a role in apoptosis. We describe the use of a yeast three-hybrid approach as a tool that adapts the classical two-hybrid system to the needs of heteromeric caspases for functional dissection of known interactions or screening for physiological substrates and inhibitors. Functional heteromeric caspase-1 was obtained by coexpression of p20(Cys285Ser) and p10 caspase-1 subunits that were each fused to the Gal4 DNA-binding domain. Upon coexpression of a third hybrid of the Gal4 activation domain and the viral caspase-1 pseudosubstrate inhibitors CrmA or p35, or the prototype physiological caspase-1 substrate prointerleukin-1beta, a functional Gal4 transcription factor could be reconstituted. In contrast, no interaction was found between CrmA or p35 and the immature p45 or p30 precursor forms of caspase-1. Therefore, the three-hybrid system might allow screening for new physiological substrates and inhibitors of heteromeric caspases.
Assuntos
Bioquímica/métodos , Caspase 1/metabolismo , Interleucina-1/metabolismo , Precursores de Proteínas/metabolismo , Serpinas/metabolismo , Proteínas Virais , Leveduras/genética , Caspase 1/genética , Inibidores de Caspase , Grânulos Citoplasmáticos/enzimologia , Células Híbridas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
Transcription of the genes for the human histone proteins H4, H3, H2A, H2B, and H1 is activated at the G1/S phase transition of the cell cycle. We have previously shown that the promoter complex HiNF-D, which interacts with cell cycle control elements in multiple histone genes, contains the key cell cycle factors cyclin A, CDC2, and a retinoblastoma (pRB) protein-related protein. However, an intrinsic DNA-binding subunit for HiNF-D was not identified. Many genes that are up-regulated at the G1/S phase boundary are controlled by E2F, a transcription factor that associates with cyclin-, cyclin-dependent kinase-, and pRB-related proteins. Using gel-shift immunoassays, DNase I protection, and oligonucleotide competition analyses, we show that the homeodomain protein CDP/cut, not E2F, is the DNA-binding subunit of the HiNF-D complex. The HiNF-D (CDP/cut) complex with the H4 promoter is immunoreactive with antibodies against CDP/cut and pRB but not p107, whereas the CDP/cut complex with a nonhistone promoter (gp91-phox) reacts only with CDP and p107 antibodies. Thus, CDP/cut complexes at different gene promoters can associate with distinct pRB-related proteins. Transient coexpression assays show that CDP/cut modulates H4 promoter activity via the HiNF-D-binding site. Hence, DNA replication-dependent histone H4 genes are regulated by an E2F-independent mechanism involving a complex of CDP/cut with cyclin A/CDC2/ RB-related proteins.