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1.
J Acoust Soc Am ; 155(1): 284-293, 2024 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-38227426

RESUMO

Spatial release from masking (SRM) in speech-on-speech tasks has been widely studied in the horizontal plane, where interaural cues play a fundamental role. Several studies have also observed SRM for sources located in the median plane, where (monaural) spectral cues are more important. However, a relatively unexplored research question concerns the impact of head-related transfer function (HRTF) personalisation on SRM, for example, whether using individually-measured HRTFs results in better performance if compared with the use of mannequin HRTFs. This study compares SRM in the median plane in a speech-on-speech virtual task rendered using both individual and mannequin HRTFs. SRM is obtained using English sentences with non-native English speakers. Our participants show lower SRM performances compared to those found by others using native English participants. Furthermore, SRM is significantly larger when the source is spatialised using the individual HRTF, and this effect is more marked for those with lower English proficiency. Further analyses using a spectral distortion metric and the estimation of the better-ear effect, show that the observed SRM can only partially be explained by HRTF-specific factors and that the effect of the familiarity with individual spatial cues is likely to be the most significant element driving these results.


Assuntos
Sinais (Psicologia) , Manequins , Humanos , Idioma , Reconhecimento Psicológico , Fala
2.
Sensors (Basel) ; 22(8)2022 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-35458893

RESUMO

The Radiation and Dust Sensor is one of six sensors of the Mars Environmental Dynamics Analyzer onboard the Perseverance rover from the Mars 2020 NASA mission. Its primary goal is to characterize the airbone dust in the Mars atmosphere, inferring its concentration, shape and optical properties. Thanks to its geometry, the sensor will be capable of studying dust-lifting processes with a high temporal resolution and high spatial coverage. Thanks to its multiwavelength design, it will characterize the solar spectrum from Mars' surface. The present work describes the sensor design from the scientific and technical requirements, the qualification processes to demonstrate its endurance on Mars' surface, the calibration activities to demonstrate its performance, and its validation campaign in a representative Mars analog. As a result of this process, we obtained a very compact sensor, fully digital, with a mass below 1 kg and exceptional power consumption and data budget features.


Assuntos
Poeira , Meio Ambiente Extraterreno , Atmosfera
3.
J Acoust Soc Am ; 149(4): 2573, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33940900

RESUMO

When performing binaural spatialisation, it is widely accepted that the choice of the head related transfer functions (HRTFs), and in particular the use of individually measured ones, can have an impact on localisation accuracy, externalization, and overall realism. Yet the impact of HRTF choices on speech-in-noise performances in cocktail party-like scenarios has not been investigated in depth. This paper introduces a study where 22 participants were presented with a frontal speech target and two lateral maskers, spatialised using a set of non-individual HRTFs. Speech reception threshold (SRT) was measured for each HRTF. Furthermore, using the SRT predicted by an existing speech perception model, the measured values were compensated in the attempt to remove overall HRTF-specific benefits. Results show significant overall differences among the SRTs measured using different HRTFs, consistently with the results predicted by the model. Individual differences between participants related to their SRT performances using different HRTFs could also be found, but their significance was reduced after the compensation. The implications of these findings are relevant to several research areas related to spatial hearing and speech perception, suggesting that when testing speech-in-noise performances within binaurally rendered virtual environments, the choice of the HRTF for each individual should be carefully considered.


Assuntos
Percepção da Fala , Fala , Limiar Auditivo , Audição , Humanos , Ruído , Teste do Limiar de Recepção da Fala
4.
J Eukaryot Microbiol ; 66(3): 385-392, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30076737

RESUMO

Since the observation of the great pleomorphism of fish trypanosomes, in vitro culture has become an important tool to support taxonomic studies investigating the biology of cultured parasites, such as their structure, growth dynamics, and cellular cycle. Relative to their biology, ex vivo and in vitro studies have shown that these parasites, during the multiplication process, duplicate and segregate the kinetoplast before nucleus replication and division. However, the inverse sequence (the nucleus divides before the kinetoplast) has only been documented for a species of marine fish trypanosomes on a single occasion. Now, this previously rare event was observed in Trypanosoma abeli, a freshwater fish trypanosome. Specifically, from 376 cultured parasites in the multiplication process, we determined the sequence of organelle division for 111 forms; 39% exhibited nucleus duplication prior to kinetoplast replication. Thus, our results suggest that nucleus division before the kinetoplast may not represent an accidental or erroneous event occurring in the main pathway of parasite reproduction, but instead could be a species-specific process of cell biology in trypanosomes, such as previously noticed for Leishmania. This "alternative" pathway for organelle replication is a new field to be explored concerning the biology of marine and freshwater fish trypanosomes.


Assuntos
Organelas/fisiologia , Trypanosoma/fisiologia , Animais , Peixes-Gato/parasitologia , Divisão Celular/fisiologia , Doenças dos Peixes/parasitologia , Tripanossomíase/parasitologia , Tripanossomíase/veterinária
5.
Geophys Res Lett ; 45(11): 5329-5335, 2018 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-32546873

RESUMO

In October and November 2014, spectra covering the 1.436 - 1.863-µm wavelength range from the SINFONI Integral Field Unit Spectrometer on the Very Large Telescope showed the presence of a vast bright North polar cap on Uranus, extending northward from about 40°N and at all longitudes observed. The feature, first detected in August 2014 from Keck telescope images, has a morphology very similar to the southern polar cap that was seen to fade before the 2007 equinox. At strong methane-absorbing wavelengths (for which only the high troposphere or stratosphere is sampled) the feature is not visible, indicating that it is not a stratospheric phenomenon. We show that the observed northern bright polar cap results mainly from a decrease in the tropospheric methane mixing ratio, rather than from a possible latitudinal variation of the optical properties or abundance of aerosol, implying an increase in polar downwelling near the tropopause level.

6.
Int Braz J Urol ; 44(5): 914-919, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30130021

RESUMO

INTRODUCTION: We report on the surgical results of a series of 91 patients who received gastric neobladders as urinary diversion after radical cystectomies performed for the treatment of muscle-invasive bladder cancers. MATERIALS AND METHODS: We report on a retrospective case series of 91 patients who received gastric neobladders as urinary diversion after radical cystectomies performed for the treatment of muscle-invasive bladder cancers. Different techniques of gastric neobladders were employed from 1988 to 2013 at a university hospital in the South of Brazil. RESULTS: Initial outcomes utilizing Leong (Antral) and Nguyen-Mitchell (Wedge) technique were unsatisfactory, yielding high pressure, low capacity reservoirs. Further developments of these techniques, with the detubularized gastric neobladder and the "spherical" gastric neobladders resulted in low pressure, high capacity reservoirs, with better surgical and urodynamic outcomes. Complication and perioperative mortality rates of our series of gastric neobladders were significantly higher than historical results of techniques using ileum or colon. CONCLUSIONS: Stomach is an exceptional option for the creation of neobladders after radical cystectomies, but due to the increased complication rates it should be reserved for specific situations (e.g., renal insufficiency, previous pelvic/abdominal radiotherapy, short bowel syndromes).


Assuntos
Cistectomia/métodos , Neoplasias da Bexiga Urinária/cirurgia , Derivação Urinária/métodos , Coletores de Urina , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Complicações Pós-Operatórias , Estudos Retrospectivos , Resultado do Tratamento , Coletores de Urina/efeitos adversos
7.
Mediators Inflamm ; 2012: 478601, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22619483

RESUMO

The flagellated protozoa Trypanosoma cruzi is the causal agent of Chagas' disease, a significant public health issue and still a major cause of morbidity and mortality in Latin America. Acute Chagas' disease elicits a strong inflammatory response. In order to control the parasite multiplication, cells of the monocytic lineage are highly mobilized. Monocyte differentiation leads to the formation of phagocytosing macrophages, which are strongly activated and direct host defense. A distinguishing feature of Chagas' disease-triggered macrophages is the presence of increased numbers of distinct cytoplasmic organelles termed lipid bodies or lipid droplets. These organelles are actively formed in response to the parasite and are sites for synthesis and storage of inflammatory mediators. This review covers current knowledge on lipid bodies elicited by the acute Chagas' disease within inflammatory macrophages and discusses the role of these organelles in inflammation. The increased knowledge of lipid bodies in pathogenic mechanisms of infections may not only contribute to the understanding of pathogen-host interactions but may also identify new targets for intervention.


Assuntos
Doença de Chagas/parasitologia , Interações Hospedeiro-Patógeno , Monócitos/parasitologia , Trypanosoma cruzi/fisiologia , Animais , Apoptose , Doença de Chagas/imunologia , Técnicas de Cocultura , Citoplasma/metabolismo , Modelos Animais de Doenças , Humanos , Imunidade Inata , Inflamação , Lipídeos/química , Macrófagos/imunologia , Macrófagos/parasitologia , Camundongos , Microscopia de Fluorescência/métodos , Monócitos/citologia , Organelas/parasitologia , Ratos , Trypanosoma cruzi/metabolismo
8.
Acta Ortop Bras ; 30(5): e256113, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36451783

RESUMO

Objective: To evaluate and compare the proportions of complications and radiographic findings of osteosynthesis of 2- and 3-part proximal humerus fractures with two methods of treatment: third-generation antegrade nailing and locking plate. Methods: 46 patients with a mean age of 58.9 ± 16.6 years between January 2020 and January 2021 were evaluated. In sixteen cases (34.8%), antegrade nailing was used, and in thirty cases (65, 2%), a locking proximal humerus plate. The method used included the rate of complications with a minimum follow-up of 6 months after surgery and radiographic evaluation. Results: There was no difference between the groups regarding the proportion of complications (nail group 18.8%, plate group 13.3%; p = 0.681). The nail group had less residual varus loss (cervicodiaphyseal angle nail group with 132.1º ± 2.3º, plate group 123.8º ± 10.1º; p < 0.001). In the plate group, women had the lowest value (1.43 ± 0.22) of the deltoid tuberosity index (DTI) compared to men (1.58 ± 0.11) (p = 0.022). Conclusion: Osteosynthesis, with a locking plate and antegrade nailing, did not show differences in the proportion of complications. The nail group had less change in the postoperative cervicodiaphyseal angle, however, there were two serious complications with screw cut-out and varus deviation, requiring surgical reapproach. Level of Evidence II, Retrospective Observational Study.


Objetivo: Avaliar retrospectivamente e comparar proporções de complicações e achados radiográficos da osteossíntese da fratura do úmero proximal em duas e três partes com dois métodos de tratamento: haste intramedular bloqueada de terceira geração e placa bloqueada. Métodos: Foram avaliados 46 pacientes com idade média de 58,9 ± 16,6 entre janeiro de 2020 a janeiro de 2021. Em 16 casos (34,8%), utilizou-se a haste intramedular e, em 30 casos (65,2%), a placa bloqueada de úmero proximal. A avaliação incluiu a taxa de complicações com seguimento mínimo de seis meses de pós-operatório e avaliação radiográfica. Resultados: Não houve diferença significativa entre os grupos quanto à proporção de complicações (grupo haste: 18,8%; grupo placa: 13,3%; p = 0,681). O grupo haste apresentou menor perda residual em varo (ângulo cervicodiafisário: grupo haste com 132,1º ± 2,3º; grupo placa com 123,8º ± 10,1º; p < 0,001). No grupo placa, as mulheres apresentaram menor índice de tuberosidade-deltoide (DTI) (1,43 ± 0,22) em relação aos homens (1,58 ± 0,11) (p = 0,022). Conclusão: No seguimento de curto prazo, a osteossíntese, com placa bloqueada ou haste intramedular, não apresentou diferenças nas proporções de complicações. O grupo haste apresentou menor alteração do ângulo cervicodiafisário no pós-operatório; entretanto, ocorreram duas complicações graves com cut out e desvio em varo com necessidade de reabordagem cirúrgica no grupo haste. Nível de Evidência II, Estudo Retrospectivo Observacional.

9.
Sci Adv ; 8(21): eabn3783, 2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35613267

RESUMO

Despite the importance of sand and dust to Mars geomorphology, weather, and exploration, the processes that move sand and that raise dust to maintain Mars' ubiquitous dust haze and to produce dust storms have not been well quantified in situ, with missions lacking either the necessary sensors or a sufficiently active aeolian environment. Perseverance rover's novel environmental sensors and Jezero crater's dusty environment remedy this. In Perseverance's first 216 sols, four convective vortices raised dust locally, while, on average, four passed the rover daily, over 25% of which were significantly dusty ("dust devils"). More rarely, dust lifting by nonvortex wind gusts was produced by daytime convection cells advected over the crater by strong regional daytime upslope winds, which also control aeolian surface features. One such event covered 10 times more area than the largest dust devil, suggesting that dust devils and wind gusts could raise equal amounts of dust under nonstorm conditions.

10.
Rev Bras Ortop (Sao Paulo) ; 56(6): 733-740, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34900101

RESUMO

Objective To evaluate and compare the glenoid track method in 3D-reconstructed computed tomography (3D-CT) scans with magnetic resonance imaging (MRI) and/or arthro-MRI. Methods Forty-four shoulders with clinical and radiographic diagnosis of traumatic anterior instability were assessed using 3D-CT, MRI, and/or arthro-MRI scans. Glenoid track (GT), Hill-Sachs interval (HSI), and glenoid bone loss (GBL) were determined by a radiologist using 3D-CT images, and classified as on-track/off-track. Three surgeons, blinded to the radiologist's evaluation, performed the same determinations using MRI/arthro-MRI. Descriptive analysis, variance analysis, results disagreement analysis, and receiver operating characteristic (ROC) curves were performed. Results Results from the 4 examiners were fully consistent in 61.4% of the cases. Magnetic resonance imaging/arthro-MRI diagnosed off-track injuries with 35 to 65% sensitivity and on-track injuries, with 91.67 to 95.83% specificity. Accuracy ranged from 68.1 to 79.5%. The greatest data divergence occurred for off-track injuries diagnosed by MRI/arthro-MRI. The greatest data variability referred to HSI calculation. Higher HSI and GBL values were associated with greater disagreement among examiners. Hill-Sachs interval values were lower at MRI/arthro-MRI when compared to 3D-CT. Agreement between CT and MRI/arthro-MRI for the GT method was only moderate (kappa value, 0.325-0.579). Conclusion Magnetic resonance imaging/arthro-MRI showed low accuracy and moderate agreement for the GT method; as such, it should be used with caution by surgeons.

11.
JSES Int ; 5(4): 616-622, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34223405

RESUMO

BACKGROUND: The investigation of Hill-Sachs and bony Bankart lesions continues to evolve. Patients with large bone lesions can present with a positive apprehension test even at ranges below 45° of abduction and external rotation of the shoulder. Modern concepts, such as glenoid track and quantification of glenoid bone loss, have been increasingly applied to shoulder instability. The objective of this study was to assess the correlation of the glenoid track and glenoid bone loss on the apprehension test conducted at 0°, 45°, and 90° of shoulder abduction. METHODS: Ninety-four shoulders of 90 patients with anterior glenohumeral instability were retrospectively assessed. The apprehension test was performed at 0°, 45°, and 90° of shoulder abduction. Computed tomography, magnetic resonance imaging, or magnetic resonance arthrogram scans were performed to calculate the glenoid track and glenoid bone loss. A descriptive analysis, an association analysis, and a logistic regression analysis were used in this study. Logistic regression analysis was used to assess the influence of glenoid track and glenoid bone loss when the apprehension test was positive in lower degrees of abduction. RESULTS: A positive apprehension test at 0°, 45°, and 90° of abduction revealed significant association with off-track lesions, glenoid bone losses greater than 13.5%, and bipolar bone lesions. Shoulders classified as off-track were 36.4 times more likely to test positive at 0°, 45°, and 90° than on-track shoulders. The logistic regression analysis revealed that the positive apprehension test at 0°, 45°, and 90° of abduction seems to be more influenced by off-track lesions than by glenoid bone loss greater than the 13.5% threshold. CONCLUSION: Shoulders with a positive apprehension test at 0°, 45°, and 90° are significantly associated with off-track lesions, bipolar bone lesions, and glenoid bone losses greater than 13.5%.

12.
Space Sci Rev ; 216(2): 21, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32165773

RESUMO

Atmospheric circulation patterns derived from multi-spectral remote sensing can serve as a guide for choosing a suitable entry location for a future in situ probe mission to the Ice Giants. Since the Voyager-2 flybys in the 1980s, three decades of observations from ground- and space-based observatories have generated a picture of Ice Giant circulation that is complex, perplexing, and altogether unlike that seen on the Gas Giants. This review seeks to reconcile the various competing circulation patterns from an observational perspective, accounting for spatially-resolved measurements of: zonal albedo contrasts and banded appearances; cloud-tracked zonal winds; temperature and para-H2 measurements above the condensate clouds; and equator-to-pole contrasts in condensable volatiles (methane, ammonia, and hydrogen sulphide) in the deeper troposphere. These observations identify three distinct latitude domains: an equatorial domain of deep upwelling and upper-tropospheric subsidence, potentially bounded by peaks in the retrograde zonal jet and analogous to Jovian cyclonic belts; a mid-latitude transitional domain of upper-tropospheric upwelling, vigorous cloud activity, analogous to Jovian anticyclonic zones; and a polar domain of strong subsidence, volatile depletion, and small-scale (and potentially seasonally-variable) convective activity. Taken together, the multi-wavelength observations suggest a tiered structure of stacked circulation cells (at least two in the troposphere and one in the stratosphere), potentially separated in the vertical by (i) strong molecular weight gradients associated with cloud condensation, and by (ii) transitions from a thermally-direct circulation regime at depth to a wave- and radiative-driven circulation regime at high altitude. The inferred circulation can be tested in the coming decade by 3D numerical simulations of the atmosphere, and by observations from future world-class facilities. The carrier spacecraft for any probe entry mission must ultimately carry a suite of remote-sensing instruments capable of fully constraining the atmospheric motions at the probe descent location.

13.
PLoS One ; 14(3): e0211899, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30856198

RESUMO

The 3D Tune-In Toolkit (3DTI Toolkit) is an open-source standard C++ library which includes a binaural spatialiser. This paper presents the technical details of this renderer, outlining its architecture and describing the processes implemented in each of its components. In order to put this description into context, the basic concepts behind binaural spatialisation are reviewed through a chronology of research milestones in the field in the last 40 years. The 3DTI Toolkit renders the anechoic signal path by convolving sound sources with Head Related Impulse Responses (HRIRs), obtained by interpolating those extracted from a set that can be loaded from any file in a standard audio format. Interaural time differences are managed separately, in order to be able to customise the rendering according the head size of the listener, and to reduce comb-filtering when interpolating between different HRIRs. In addition, geometrical and frequency-dependent corrections for simulating near-field sources are included. Reverberation is computed separately using a virtual loudspeakers Ambisonic approach and convolution with Binaural Room Impulse Responses (BRIRs). In all these processes, special care has been put in avoiding audible artefacts produced by changes in gains and audio filters due to the movements of sources and of the listener. The 3DTI Toolkit performance, as well as some other relevant metrics such as non-linear distortion, are assessed and presented, followed by a comparison between the features offered by the 3DTI Toolkit and those found in other currently available open- and closed-source binaural renderers.


Assuntos
Estimulação Acústica/métodos , Software , Localização de Som , Humanos , Psicofísica/métodos
14.
Front Microbiol ; 9: 499, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29616011

RESUMO

During Chagas disease, the Trypanosoma cruzi can induce some changes in the host cells in order to escape or manipulate the host immune response. The modulation of the lipid metabolism in the host phagocytes or in the parasite itself is one feature that has been observed. The goal of this mini review is to discuss the mechanisms that regulate intracellular lipid body (LB) biogenesis in the course of this parasite infection and their meaning to the pathophysiology of the disease. The interaction host-parasite induces LB (or lipid droplet) formation in a Toll-like receptor 2-dependent mechanism in macrophages and is enhanced by apoptotic cell uptake. Simultaneously, there is a lipid accumulation in the parasite due to the incorporation of host fatty acids. The increase in the LB accumulation during infection is correlated with an increase in the synthesis of PGE2 within the host cells and the parasite LBs. Moreover, the treatment with fatty acid synthase inhibitor C75 or non-steroidal anti-inflammatory drugs such as NS-398 and aspirin inhibited the LB biogenesis and also induced the down modulation of the eicosanoid production and the parasite replication. These findings show that LBs are organelles up modulated during the course of infection. Furthermore, the biogenesis of the LB is involved in the lipid mediator generation by both the macrophages and the parasite triggering escape mechanisms.

16.
Acta ortop. bras ; 30(5): e256113, 2022. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1403048

RESUMO

ABSTRACT Objective: To evaluate and compare the proportions of complications and radiographic findings of osteosynthesis of 2- and 3-part proximal humerus fractures with two methods of treatment: third-generation antegrade nailing and locking plate. Methods: 46 patients with a mean age of 58.9 ± 16.6 years between January 2020 and January 2021 were evaluated. In sixteen cases (34.8%), antegrade nailing was used, and in thirty cases (65, 2%), a locking proximal humerus plate. The method used included the rate of complications with a minimum follow-up of 6 months after surgery and radiographic evaluation. Results: There was no difference between the groups regarding the proportion of complications (nail group 18.8%, plate group 13.3%; p = 0.681). The nail group had less residual varus loss (cervicodiaphyseal angle nail group with 132.1º ± 2.3º, plate group 123.8º ± 10.1º; p < 0.001). In the plate group, women had the lowest value (1.43 ± 0.22) of the deltoid tuberosity index (DTI) compared to men (1.58 ± 0.11) (p = 0.022). Conclusion: Osteosynthesis, with a locking plate and antegrade nailing, did not show differences in the proportion of complications. The nail group had less change in the postoperative cervicodiaphyseal angle, however, there were two serious complications with screw cut-out and varus deviation, requiring surgical reapproach. Level of Evidence II, Retrospective Observational Study.


RESUMO Objetivo: Avaliar retrospectivamente e comparar proporções de complicações e achados radiográficos da osteossíntese da fratura do úmero proximal em duas e três partes com dois métodos de tratamento: haste intramedular bloqueada de terceira geração e placa bloqueada. Métodos: Foram avaliados 46 pacientes com idade média de 58,9 ± 16,6 entre janeiro de 2020 a janeiro de 2021. Em 16 casos (34,8%), utilizou-se a haste intramedular e, em 30 casos (65,2%), a placa bloqueada de úmero proximal. A avaliação incluiu a taxa de complicações com seguimento mínimo de seis meses de pós-operatório e avaliação radiográfica. Resultados: Não houve diferença significativa entre os grupos quanto à proporção de complicações (grupo haste: 18,8%; grupo placa: 13,3%; p = 0,681). O grupo haste apresentou menor perda residual em varo (ângulo cervicodiafisário: grupo haste com 132,1º ± 2,3º; grupo placa com 123,8º ± 10,1º; p < 0,001). No grupo placa, as mulheres apresentaram menor índice de tuberosidade-deltoide (DTI) (1,43 ± 0,22) em relação aos homens (1,58 ± 0,11) (p = 0,022). Conclusão: No seguimento de curto prazo, a osteossíntese, com placa bloqueada ou haste intramedular, não apresentou diferenças nas proporções de complicações. O grupo haste apresentou menor alteração do ângulo cervicodiafisário no pós-operatório; entretanto, ocorreram duas complicações graves com cut out e desvio em varo com necessidade de reabordagem cirúrgica no grupo haste. Nível de Evidência II, Estudo Retrospectivo Observacional.

17.
Front Immunol ; 7: 174, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27199996

RESUMO

Pathogens induce several changes in the host cell signaling and trafficking mechanisms in order to evade and manipulate the immune response. One prominent pathogen-mediated change is the formation of lipid-rich organelles, termed lipid bodies (LBs) or lipid droplets, in the host cell cytoplasm. Protozoan parasites, which contribute expressively to the burden of infectious diseases worldwide, are able to induce LB genesis in non-immune and immune cells, mainly macrophages, key players in the initial resistance to the infection. Under host-parasite interaction, LBs not only accumulate in the host cytoplasm but also relocate around and move into parasitophorous vacuoles. There is increasing evidence that protozoan parasites may target host-derived LBs either for gaining nutrients or for escaping the host immune response. Newly formed, parasite-induced LBs may serve as lipid sources for parasite growth and also produce inflammatory mediators that potentially act in the host immune response deactivation. In this mini review, we summarize current knowledge on the formation and role of host LBs as sites exploited by intracellular protozoan parasites as a strategy to maintain their own survival.

18.
Rev. bras. ortop ; 56(6): 733-740, Nov.-Dec. 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1357128

RESUMO

Abstract Objective To evaluate and compare the glenoid track method in 3D-reconstructed computed tomography (3D-CT) scans with magnetic resonance imaging (MRI) and/or arthro-MRI. Methods Forty-four shoulders with clinical and radiographic diagnosis of traumatic anterior instability were assessed using 3D-CT, MRI, and/or arthro-MRI scans. Glenoid track (GT), Hill-Sachs interval (HSI), and glenoid bone loss (GBL) were determined by a radiologist using 3D-CT images, and classified as on-track/off-track. Three surgeons, blinded to the radiologist's evaluation, performed the same determinations using MRI/arthro-MRI. Descriptive analysis, variance analysis, results disagreement analysis, and receiver operating characteristic (ROC) curves were performed. Results Results from the 4 examiners were fully consistent in 61.4% of the cases. Magnetic resonance imaging/arthro-MRI diagnosed off-track injuries with 35 to 65% sensitivity and on-track injuries, with 91.67 to 95.83% specificity. Accuracy ranged from 68.1 to 79.5%. The greatest data divergence occurred for off-track injuries diagnosed by MRI/arthro-MRI. The greatest data variability referred to HSI calculation. Higher HSI and GBL values were associated with greater disagreement among examiners. Hill-Sachs interval values were lower at MRI/arthro-MRI when compared to 3D-CT. Agreement between CT and MRI/arthro-MRI for the GT method was only moderate (kappa value, 0.325-0.579). Conclusion Magnetic resonance imaging/arthro-MRI showed low accuracy and moderate agreement for the GT method; as such, it should be used with caution by surgeons.


Resumo Objetivo Comparar a avaliação do método glenoid-track (GT) em exames de tomografia computadorizada com reconstrução 3-D (TC-3D) com a avaliação realizada em exames de ressonância magnética (RM) e/ou artro-ressonância magnética (ARM). Métodos Quarenta e quatro ombros com diagnóstico clínico e radiográfico de instabilidade anterior traumática foram avaliados por meio de exames de TC-3D, RM e/ou ARM. As variáveis GT, intervalo de Hill-Sachs (IHS) e a perda óssea da glenoide (POG) foram realizadas por um médico radiologista, utilizando imagens de TC-3D, e classificadas em on-track/off-track. Três cirurgiões cegos à avaliação do radiologista realizaram o mesmo método utilizando RM/ARM. O estudo realizou análise descritiva, de variância, de associação da discordância de resultados, de concordância e curva característica de operação do receptor. Resultados Os resultados dos 4 examinadores foram totalmente concordantes em 61,4%. A RM/ARM diagnosticou lesões off-track com a sensibilidade variando de 35 a 65%, e lesões on-track com a especificidade variando de 91,67 a 95,83%. A acurácia variou de 68,1 a 79,5%. A maior divergência de dados ocorreu para o diagnóstico por RM/ARM de lesões off-track. A maior variabilidade dos dados ocorreu para o cálculo do IHS. Valores maiores de IHS e de POG foram associados a maior discordância entre os examinadores. A RM/ARM apresentou menor medida de valores de IHS quando comparado com a TC-3D. Ocorreu apenas moderada concordância no método GT entre a TC e a RM/ARM (Kappa 0,325-0,579). Conclusão A RM/ARM apresentou baixa acurácia e moderada concordância para o método GT, devendo ser utilizada com cautela por cirurgiões.


Assuntos
Humanos , Espectroscopia de Ressonância Magnética , Tomografia Computadorizada por Raios X , Diagnóstico Clínico , Cavidade Glenoide , Lesões do Ombro
19.
Rev. cuba. cir ; 60(3): e1090, 2021.
Artigo em Espanhol | LILACS, CUMED | ID: biblio-1347385

RESUMO

Introducción: Los cirujanos pueden desempeñar un papel valioso en la realización de traqueostomía para apoyar a los equipos de cuidados críticos durante la pandemia global de la COVID-19. Objetivo: Diseñar un protocolo para realizar la traqueostomía en pacientes con la COVID-19. Métodos: Se realizó un estudio descriptivo durante el periodo de marzo a diciembre del año 2020 en el Hospital "Comandante Manuel Fajardo Rivero", de Santa Clara, Villa Clara. Se emplearon como métodos teóricos: el análisis-síntesis e inductivo-deductivo; y como empíricos: análisis documental, grupo nominal y el criterio de especialistas para la valoración del producto diseñado. Resultados: El protocolo fue estructurado en: título, propósito, normas organizativas institucionales, indicaciones, procedimiento de actuación y evaluación. Según el criterio de los especialistas consultados el protocolo diseñado, es pertinente, factible y válido. Conclusiones: Para el diseño del protocolo fue fundamental aplicar y adaptar cuidadosamente la mejor evidencia existente sobre la realización de la traqueostomía. Su estructura permite brindar la mejor atención al paciente con la COVID-19 al tiempo que protege al equipo quirúrgico(AU)


Introduction: Surgeons can play a valuable role in performing tracheostomy, as a support for critical care teams during the global COVID-19 pandemic. Objective: To design a protocol for performing the tracheostomy in patients with COVID-19. Methods: A descriptive study was carried out, during the period from March to December 2020, at Comandante Manuel Fajardo Rivero Hospital, in Santa Clara City, Villa Clara Province. The following theoretical methods were used: analysis-synthesis and inductive-deductive; as well as empirical ones: documentary analysis, nominal group and criteria of specialists for the evaluation of the designed product. Results: The protocol was structured into title, purpose, institutional organizational norms, indications, procedure of action and evaluation. According to the criteria of the specialists consulted, the designed protocol is pertinent, feasible and valid. Conclusions: For the design of the protocol, it was essential to apply and adapt, carefully, the best existing evidence on tracheostomy performance. Its structure allows to provide the best care to the patient with COVID-19 while protecting the surgical team(AU)


Assuntos
Humanos , Traqueostomia/métodos , Protocolos Clínicos , Cuidados Críticos/métodos , Assistência ao Paciente/efeitos adversos , COVID-19/etiologia , Epidemiologia Descritiva
20.
PLoS One ; 11(8): e0160433, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27490663

RESUMO

Most eukaryotic cells contain varying amounts of cytosolic lipidic inclusions termed lipid bodies (LBs) or lipid droplets (LDs). In mammalian cells, such as macrophages, these lipid-rich organelles are formed in response to host-pathogen interaction during infectious diseases and are sites for biosynthesis of arachidonic acid (AA)-derived inflammatory mediators (eicosanoids). Less clear are the functions of LBs in pathogenic lower eukaryotes. In this study, we demonstrated that LBs, visualized by light microscopy with different probes and transmission electron microscopy (TEM), are produced in trypomastigote forms of the parasite Trypanosoma cruzi, the causal agent of Chagas' disease, after both host interaction and exogenous AA stimulation. Quantitative TEM revealed that LBs from amastigotes, the intracellular forms of the parasite, growing in vivo have increased size and electron-density compared to LBs from amastigotes living in vitro. AA-stimulated trypomastigotes released high amounts of prostaglandin E2 (PGE2) and showed PGE2 synthase expression. Raman spectroscopy demonstrated increased unsaturated lipid content and AA incorporation in stimulated parasites. Moreover, both Raman and MALDI mass spectroscopy revealed increased AA content in LBs purified from AA-stimulated parasites compared to LBs from unstimulated group. By using a specific technique for eicosanoid detection, we immunolocalized PGE2 within LBs from AA-stimulated trypomastigotes. Altogether, our findings demonstrate that LBs from the parasite Trypanosoma cruzi are not just lipid storage inclusions but dynamic organelles, able to respond to host interaction and inflammatory events and involved in the AA metabolism. Acting as sources of PGE2, a potent immunomodulatory lipid mediator that inhibits many aspects of innate and adaptive immunity, newly-formed parasite LBs may be implicated with the pathogen survival in its host.


Assuntos
Ácido Araquidônico/metabolismo , Gotículas Lipídicas/metabolismo , Trypanosoma cruzi/metabolismo , Doença de Chagas/metabolismo , Dinoprostona/metabolismo , Gotículas Lipídicas/ultraestrutura , Prostaglandina-E Sintases/biossíntese , Proteínas de Protozoários/biossíntese , Trypanosoma cruzi/ultraestrutura
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