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1.
Am J Physiol Lung Cell Mol Physiol ; 319(4): L670-L674, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32878480

RESUMO

The severity of coronavirus disease 2019 (COVID-19) is linked to an increasing number of risk factors, including exogenous (environmental) stimuli such as air pollution, nicotine, and cigarette smoke. These three factors increase the expression of angiotensin I converting enzyme 2 (ACE2), a key receptor involved in the entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-the etiological agent of COVID-19-into respiratory tract epithelial cells. Patients with severe COVID-19 are managed with oxygen support, as are at-risk individuals with chronic lung disease. To date, no study has examined whether an increased fraction of inspired oxygen (FiO2) may affect the expression of SARS-CoV-2 entry receptors and co-receptors, including ACE2 and the transmembrane serine proteases TMPRSS1, TMPRSS2, and TMPRSS11D. To address this, steady-state mRNA levels for genes encoding these SARS-CoV-2 receptors were assessed in the lungs of mouse pups chronically exposed to elevated FiO2, and in the lungs of preterm-born human infants chronically managed with an elevated FiO2. These two scenarios served as models of chronic elevated FiO2 exposure. Additionally, SARS-CoV-2 receptor expression was assessed in primary human nasal, tracheal, esophageal, bronchial, and alveolar epithelial cells, as well as primary mouse alveolar type II cells exposed to elevated oxygen concentrations. While gene expression of ACE2 was unaffected, gene and protein expression of TMPRSS11D was consistently upregulated by exposure to an elevated FiO2. These data highlight the need for further studies that examine the relative contribution of the various viral co-receptors on the infection cycle, and point to oxygen supplementation as a potential risk factor for COVID-19.


Assuntos
Infecções por Coronavirus/patologia , Proteínas de Membrana/metabolismo , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/patologia , Mucosa Respiratória/metabolismo , Serina Endopeptidases/metabolismo , Serina Proteases/metabolismo , Células Epiteliais Alveolares/metabolismo , Animais , Betacoronavirus , Células Cultivadas , Feminino , Humanos , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Oxigênio/administração & dosagem , Oxigênio/análise , Pandemias , Receptores Virais/metabolismo , Fatores de Risco , Serina Endopeptidases/genética , Serina Proteases/genética , Índice de Gravidade de Doença
2.
Sensors (Basel) ; 20(17)2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32872310

RESUMO

The non-invasive estimation of blood oxygen saturation (SpO2) by pulse oximetry is of vital importance clinically, from the detection of sleep apnea to the recent ambulatory monitoring of hypoxemia in the delayed post-infective phase of COVID-19. In this proof of concept study, we set out to establish the feasibility of SpO2 measurement from the ear canal as a convenient site for long term monitoring, and perform a comprehensive comparison with the right index finger-the conventional clinical measurement site. During resting blood oxygen saturation estimation, we found a root mean square difference of 1.47% between the two measurement sites, with a mean difference of 0.23% higher SpO2 in the right ear canal. Using breath holds, we observe the known phenomena of time delay between central circulation and peripheral circulation with a mean delay between the ear and finger of 12.4 s across all subjects. Furthermore, we document the lower photoplethysmogram amplitude from the ear canal and suggest ways to mitigate this issue. In conjunction with the well-known robustness to temperature induced vasoconstriction, this makes conclusive evidence for in-ear SpO2 monitoring being both convenient and superior to conventional finger measurement for continuous non-intrusive monitoring in both clinical and everyday-life settings.


Assuntos
Meato Acústico Externo , Hipóxia/diagnóstico , Monitorização Fisiológica/instrumentação , Oximetria/instrumentação , Fotopletismografia/instrumentação , Dispositivos Eletrônicos Vestíveis , Adulto , Betacoronavirus/fisiologia , Infecções por Coronavirus/sangue , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/terapia , Estudos de Equivalência como Asunto , Estudos de Viabilidade , Feminino , Dedos , Humanos , Hipóxia/sangue , Masculino , Monitorização Fisiológica/métodos , Oximetria/métodos , Oxigênio/análise , Oxigênio/sangue , Pandemias , Fotopletismografia/métodos , Pneumonia Viral/sangue , Pneumonia Viral/diagnóstico , Pneumonia Viral/terapia , Adulto Jovem
3.
J Chromatogr A ; 1626: 461355, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797835

RESUMO

Quantification of the gas streams from chemical systems such as catalytic reactors are routinely performed by on-line gas chromatography. Gas chromatographs used for this purpose are typically provided with a combination of thermal conductivity (TCD) and flame ionization (FID) detectors to be able to detect and quantify both permanent gases; COx, N2, H2, etc., and hydrocarbons. However, the accuracy of the quantification is hindered by the intrinsic limitations of each type of detector. Namely, TCD has low sensitivity and FID does not detect permanent gases. Therefore, modern gas chromatographs include methanizer units to partially overcome this shortcoming by converting COx to methane. However, as far as these authors know, the literature has not presented an analytical method to characterize gas streams with high accuracy by the simultaneous use of a combination of a TCD-FID detection system provided with a methanizer. This work is an attempt to solve this problematic; it consists of the formulation of a mathematical model for the well-known external and internal standard quantification methods in gas chromatography. The analysis of the gas stream from a catalytic reactor performing the combustion of methane was used to validate the developed method. The concentration ranges of the analysed gases were: 0.8-7.7 vol% of CH4, CO2, and CO, 7.7-38.5 vol.% of O2, and 46.2-90.8 vol.% of N2 at a total flow of 130 mL min-1. It was found that the commonly applied external standard method leads not only to inaccurate quantification but also to physically meaningless carbon balances and conclusions on the behaviour of the selected model system. In contrast, the internal standard method led to a highly accurate quantification with a physically meaningful carbon balance. Considering these findings, this contribution also draws attention to the need for a thoughtful application of chromatographic methods when studying the reactivity of gas systems.


Assuntos
Cromatografia Gasosa/métodos , Gases/análise , Sistemas On-Line , Carbono/análise , Catálise , Ionização de Chama , Metano/análise , Oxigênio/análise , Padrões de Referência , Reprodutibilidade dos Testes , Condutividade Térmica
4.
Environ Pollut ; 265(Pt B): 115066, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32806459

RESUMO

Hypoxia off the Changjiang Estuary (CE) and its adjacent waters is purported to be the most severe in China, attracting considerable concern from both the scientific community and the general public. Currently, continuous observations of dissolved oxygen (DO) levels covering hypoxia from its appearance to disappearance are lacking. In this study, twelve consecutive monthly cruises (from February 2015 to January 2016) were conducted. The consecutive spatiotemporal variations in hypoxia throughout the annual cycle were elucidated in detail, and the responses of annual variations in hypoxia to the different influential factors were explored. Overall, hypoxia experienced a consecutive process of expanding from south to north, then disappearing from north to south. The annual variations in hypoxia were mainly contingent on stratification variations. Among different stages, there was significant heterogeneity in the dominant factors. Specifically, low-DO waters initially appeared from the intrusion of nearshore Kuroshio branch current (NKBC), as NKBC intrusion provided a low-DO background and triggered stratification. Thereafter, stratification was enhanced and gradually expanded northward, which promoted the extension of low-DO areas. The formation of hypoxia was regionally selective, and more intense organic matter decomposition at local regions facilitated the occurrence and discontinuous distribution of hypoxia. Hypoxic zones were observed at the Changjiang bank and Zhejiang coastal region from August (most extensively at 14,800 km2) to October. Thereafter, increased vertical mixing facilitated the dissipation of hypoxia from north to south.


Assuntos
Estuários , Oxigênio/análise , China , Humanos , Hipóxia
5.
PLoS Negl Trop Dis ; 14(8): e0008406, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32776919

RESUMO

We hypothesized that Cholera (Vibrio cholerae) that appeared along Lake Kivu in the African Rift in the seventies, might be controlled by volcano-tectonic activity, which, by increasing surface water and groundwater salinity and temperature, may partly rule the water characteristics of Lake Kivu and promote V. cholerae proliferation. Volcanic activity (assessed weekly by the SO2 flux of Nyiragongo volcano plume over the 2007-2012 period) is highly positively correlated with the water conductivity, salinity and temperature of the Kivu lake. Over the 2007-2012 period, these three parameters were highly positively correlated with the temporal dynamics of cholera cases in the Katana health zone that border the lake. Meteorological variables (air temperature and rainfall), and the other water characteristics (namely pH and dissolved oxygen concentration in lake water) were unrelated to cholera dynamics over the same period. Over the 2016-2018 period, we sampled weekly lake water salinity and conductivity, and twice a month vibrio occurrence in lake water and fish. The abundance of V. cholerae in the lake was positively correlated with lake salinity, temperature, and the number of cholera cases in the population of the Katana health zone. V. cholerae abundance in fishes was positively correlated with V. cholerae abundance in lake water, suggesting that their consumption directly contaminate humans. The activity of the volcano, by controlling the physico-chemical characteristics of Lake Kivu, is therefore a major determinant of the presence of the bacillus in the lake. SO2 fluxes in the volcano plume can be used as a tool to predict epidemic risks.


Assuntos
Cólera/epidemiologia , Lagos/química , Lagos/microbiologia , Erupções Vulcânicas/efeitos adversos , Animais , República Democrática do Congo/epidemiologia , Condutividade Elétrica , Peixes/microbiologia , Humanos , Concentração de Íons de Hidrogênio , Oxigênio/análise , Ruanda , Salinidade , Dióxido de Enxofre/análise , Temperatura , Vibrio , Microbiologia da Água
6.
Mar Pollut Bull ; 157: 111311, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32658677

RESUMO

Hypoxia is often thought of as the key factor responsible for fish kill events in coastal areas but fish kill events are too complex to be governed by a single factor. The events are influenced by a combination of chemical, biological and physical processes. Hydrodynamics play a key role in understanding the formation of hypoxia in shallow waters. This study aims to identify the settings of the physical forces that lead to a large-scale depletion of dissolved oxygen in Kuwait Bay at the northwest of the Arabian Gulf. The assessment, made with a validated three-dimensional numerical model (Alosairi and Alsulaiman, 2019), revealed that the pollution from the outfalls leads to nearfield depletion of dissolved oxygen but has only a minor effect on the bay-scale dissolved oxygen. This is a result of the strong dynamics of Kuwait Bay, which mixes the pollutant rapidly before it is transported seawards. Offshore, a low dynamic region has been identified near Jahra Bay which is susceptible to occasional dissolved oxygen depletion. Assessment of the physical forces revealed that the density-driven current and, to a greater extent the wind regime, controlled the formation of a hypoxic parcel near Jahra Bay. The combination of neap tides and low mixed winds reduced mixing and enabled the longer residence times of Kuwait Bay. These are the most critical circumstances, as the average dissolved oxygen can be reduced by 50% during summer. The circumstance resulting in low dynamics near Jahra Bay were also found to be effective in explaining algal blooms.


Assuntos
Monitoramento Ambiental , Eutrofização , Animais , Hipóxia , Kuweit , Oxigênio/análise , Vento
7.
Proc Natl Acad Sci U S A ; 117(29): 17063-17067, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32631997

RESUMO

Little is known about the exchange of gaseous nitrogen (N2) with the atmosphere in freshwater systems. Although the exchange of N2, driven by excess or deficiencies relative to saturation values, has little relevance to the atmospheric N2 pool due to its large size, it does play an important role in freshwater and marine nitrogen (N) cycling. N-fixation converts N2 to ammonia, which can be used by microbes and phytoplankton, while denitrification/anammox effectively removes it by converting oxidized, inorganic N to N2 We examined N2 saturation to infer net biological nitrogen processes in 34 lakes across 5° latitude varying in trophic status, mixing regime, and bathymetry. Here, we report that nearly all lakes examined in the upper Midwest (USA) were supersaturated with N2 (>85% of samples, n = 248), suggesting lakes are continuously releasing nitrogen to the atmosphere. The traditional paradigm is that freshwaters compensate for N-limitation through N-fixation, but these results indicate that lakes were constantly losing N to the atmosphere via denitrification and/or anammox, suggesting that terrestrial N inputs are needed to balance the internal N cycle.


Assuntos
Lagos , Nitrogênio/análise , Argônio/análise , Gases de Efeito Estufa/análise , Lagos/análise , Lagos/química , Minnesota , Fixação de Nitrogênio , Oxigênio/análise
8.
Chemosphere ; 258: 127314, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32540543

RESUMO

The formation, fate, and toxicology of oxy-, hydroxy-, and carboxy- substituted PAH (OPAH, OHPAH, COOHPAH, respectively) alongside PAH in contaminated soils have received increasing attention over the past two decades; however, there are still to date no standardized methods available for their identification and quantitation in soil. Here we investigated and developed the first method using aminopropylsilica solid phase extraction (SPE) for these compounds. We further investigated the efficacy of the developed method for three soils representing a range of contamination levels and soil textural characteristics and evaluated the impact of different sample preparation steps on the recovery of targeted compounds. Average recovery of PAH, OPAH, and OHPAH standards were 99%, 84%, and 86%, respectively for the SPE method. In contrast, COOHPAH exhibited the lowest recovery (0-82%) and poor inter-batch reproducibility. Soil texture and contamination levels influenced full method efficiency. Specifically, soils with higher proportion of clay contributed to the loss of the higher molecular weight OHPAH prior to SPE. Soil with the highest contamination showed enhanced recovery of some lower-concentration mid weight PAH and OPAH, while the least contaminated soil showed greater sensitivity to evaporative losses during sample preparation. Recommendations for reducing matrix effects as well as the practice of using deuterated PAH surrogate standards for OPAH analysis are further discussed. Quantitation of recovered PAH and oxygenated PAH across the three soils showed high reproducibility (<10% relative standard deviation for a majority of compounds), supporting the use of this method for PAH, OPAH, and OHPAH at contaminated sites.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos/química , Poluentes do Solo/química , Extração em Fase Sólida/métodos , Respiração Celular , Argila , Monitoramento Ambiental/métodos , Poluição Ambiental/análise , Oxigênio/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Reprodutibilidade dos Testes , Dióxido de Silício/análise , Solo , Poluentes do Solo/análise
9.
J Environ Manage ; 270: 110834, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32507742

RESUMO

The biochemical oxygen demand (BOD), one of widely utilized variables for water quality assessment, is metric for the ecological division in rivers. Since the traditional approach to predict BOD is time-consuming and inaccurate due to inconstancies in microbial multiplicity, alternative methods have been recommended for more accurate prediction of BOD. This study investigated the capability of a novel deep learning-based model, Deep Echo State Network (Deep ESN), for predicting BOD, based on various water quality variables, at Gongreung and Gyeongan stations, South Korea. The model was compared with the Extreme Learning Machine (ELM) and two ensemble tree models comprising the Gradient Boosting Regression Tree (GBRT) and Random Forests (RF). Diverse water quality variables (i.e., BOD, potential of Hydrogen (pH), electrical conductivity (EC), dissolved oxygen (DO), water temperature (WT), chemical oxygen demand (COD), suspended solids (SS), total nitrogen (T-N), and total phosphorus (T-P)) were utilized for developing the Deep ESN, ELM, GBRT, and RF with five input combinations (i.e., Categories 1-5). These models were evaluated by root mean square error (RMSE), Nash-Sutcliffe efficiency (NSE), coefficient of determination (R2), and correlation coefficient (R). Overall evaluations suggested that the Deep ESN5 model provided the most reliable predictions of BOD among all the models at both stations.


Assuntos
Redes Neurais de Computação , Qualidade da Água , Análise da Demanda Biológica de Oxigênio , Monitoramento Ambiental , Oxigênio/análise , República da Coreia , Rios
10.
Mar Pollut Bull ; 152: 110912, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32479286

RESUMO

The oxygen minimum zones (OMZs) and other hypoxic seawaters are considered as the main areas of oceanic nitrogen loss. The laboratory simulation culture was conducted to study the main reactions, rates and proportions of dissolved inorganic nitrogen (DIN) in different dissolved oxygen concentrations seawater, with aim of clarifying the process of nitrogen loss in hypoxic seawater. The results showed that the change of DIN in hypoxic water could be divided into three stages. In the first stage, the main reactions were the dissimilatory nitrate reduction to ammonium (DNRA) and denitrification. In the second stage, anammox and denitrification were main reactions. In the last stage, anammox was the most important nitrogen loss reaction; nitrogen loss eventually reached a relative balance with the input from sediment mineralization. Based on the data obtained from the last stage, the annual nitrogen loss could be estimated to be about 240-260 Tg in the global OMZs.


Assuntos
Compostos de Amônio/análise , Nitrogênio/análise , Desnitrificação , Nitratos/análise , Oceanos e Mares , Oxirredução , Oxigênio/análise , Água do Mar
11.
Adv Exp Med Biol ; 1259: 53-76, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32578171

RESUMO

There are many reasons to try to achieve a good grasp of the distribution of oxygen in the tumor microenvironment. The lack of oxygen - hypoxia - is a main actor in the evolution of tumors and in their growth and appears to be just as important in tumor invasion and metastasis. Mathematical models of the distribution of oxygen in tumors which are based on reaction-diffusion equations provide partial but qualitatively significant descriptions of the measured oxygen concentrations in the tumor microenvironment, especially when they incorporate important elements of the blood vessel network such as the blood vessel size and spatial distribution and the pulsation of local pressure due to blood circulation. Here, we review our mathematical and numerical approaches to the distribution of oxygen that yield insights both on the role of the distribution of blood vessel density and size and on the fluctuations of blood pressure.


Assuntos
Hipóxia Celular , Modelos Biológicos , Neoplasias/metabolismo , Oxigênio/metabolismo , Microambiente Tumoral , Simulação por Computador , Difusão , Humanos , Neoplasias/irrigação sanguínea , Oxigênio/análise
12.
PLoS One ; 15(6): e0234507, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32526771

RESUMO

INTRODUCTION: Maximal oxygen uptake ([Formula: see text]) is a measure of cardiorespiratory fitness often used to monitor changes in fitness during and after treatment in cancer patients. There is, however, limited knowledge in how criteria verifying [Formula: see text] work for patients newly diagnosed with cancer. Therefore, the aim of this study was to describe the prevalence of fulfillment of typical criteria verifying [Formula: see text] and to investigate the associations between the criteria and the test leader's evaluation whether a test was performed "to exhaustion". An additional aim was to establish new cut-points within the associated criteria. METHODS: From the Phys-Can randomized controlled trial, 535 patients (59 ±12 years) newly diagnosed with breast (79%), prostate (17%) or colorectal cancer (4%) performed an incremental [Formula: see text] test on a treadmill. The test was performed before starting (neo-)adjuvant treatment and an exercise intervention. Fulfillment of different cut-points within typical criteria verifying [Formula: see text] was described. The dependent key variables included in the initial bivariate analysis were achievement of a [Formula: see text] plateau, peak values for maximal heart rate, respiratory exchange ratio (RER), the patients' rating of perceived exertion on Borg's scale6-20 and peak breathing frequency (fR). A receiver operating characteristic analysis was performed to establish cut-points for variables associated with the test leader's evaluation. Last, a cross-validation of the cut-points found in the receiver operating characteristic analysis was performed on a comparable sample of cancer patients (n = 80). RESULTS: The criteria RERpeak (<0.001), Borg's RPE (<0.001) and fR peak (p = 0.018) were associated with the test leader's evaluation of whether a test was defined as "to exhaustion". The cut-points that best predicted the test leader's evaluation were RER ≥ 1.14, RPE ≥ 18 and fR ≥ 40. Maximal heart rate and [Formula: see text] plateau was not associated with the test leader's evaluation. CONCLUSION: We recommend a focus on RER (in the range between ≥1.1 and ≥1.15) and RPE (≥17 or ≥18) in addition to the test leader's evaluation. Additionally, a fR peak of ≥40 breaths/min may be a cut-point to help the test leader evaluate the degree of exhaustion. However, more research is needed to verify our findings, and to investigate how these criteria will work within a population that are undergoing or finished with cancer treatment.


Assuntos
Aptidão Cardiorrespiratória/fisiologia , Teste de Esforço/métodos , Terapia por Exercício , Neoplasias/reabilitação , Oxigênio/análise , Idoso , Estudos de Coortes , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/diagnóstico , Neoplasias/fisiopatologia , Oxigênio/metabolismo , Consumo de Oxigênio , Esforço Físico/fisiologia , Curva ROC , Valores de Referência , Resultado do Tratamento
14.
Isotopes Environ Health Stud ; 56(3): 314-323, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32490744

RESUMO

A novel method of the accelerated equilibration of 18O between CO2 and H2O for the measurement of the 18O/16O isotope ratios in aqueous samples with natural isotope abundances is presented. This rapid equilibrium method is based on the in vitro application of the enzyme carbonic anhydrase (CA). The CA from bovine erythrocytes was adsorptively fixed to 3-mm glass beads with an etched surface. After the addition of this carrier-fixed CA catalyst to the water sample, the isotope equilibrium was already reached after 1 h. The previously used non-catalysed 18O isotope exchange in water samples needs about 24 h. Whole blood samples also showed fast 18O isotope equilibration, which definitely results from the native presence of CA in erythrocytes. By shortening the time for sample preparation, the CA catalysed technique can significantly increase the throughput of the samples to be measured, and also 18O and 2H measurement by means of isotope ratio mass spectrometry (IRMS) may be synchronized. The 2H and 18O sample preparation can be performed in the same reaction vessel because cross-effects at the simultaneous use of Pt and CA catalysts do not occur.


Assuntos
Dióxido de Carbono/análise , Anidrases Carbônicas/química , Deutério/análise , Isótopos de Oxigênio/análise , Oxigênio/análise , Animais , Bovinos , Espectrometria de Massas/métodos , Análise Espectral , Água/química
19.
Int J Food Microbiol ; 324: 108612, 2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32244103

RESUMO

Effect of in-bag dielectric barrier discharge cold plasma (IB-DBD-CP) on the keeping quality of Asian sea bass slices (ASBS) packaged under different gases during refrigerated storage at 4 °C was studied. ASBS without and with IB-DBD-CP treatment packaged under the gas combination of argon and oxygen (10:90) (gas A) or the mixtures of carbon dioxide, argon and oxygen (60:30:10) (gas B) and the control (kept in air) were monitored for quality changes up to 18 days. ASBS treated with IB-DBD-CP, regardless of gas composition, had lower microbial loads than those without treatment and the control (p < 0.05). The shelf-life of ASBS was prolonged to 9 and 12 days after being packaged under gas A and B, respectively without IB-DBD-CP treatment, while 6 days were recorded for the control. However, ASBS treated with IB-DBD-CP, packaged under gas A and B had the shelf-life of 12 and 15 days, respectively. Throughout the storage, trimethylamine content and total volatile nitrogen base content were lower in ASBS treated with IB-DBD-CP, particularly those packaged under gas B than that without treatment and the control (p < 0.05). Nevertheless, lipid oxidation as well as protein oxidation were higher in samples treated with IB-DBD-CP, regardless of gas composition used, in comparison with untreated counterpart. Therefore, IB-DBD-CP of ASBS packaged under high ratio of CO2 (60%) along with argon and oxygen was the potential method for augmenting the shelf-life of ASBS for >15 days at 4 °C.


Assuntos
Bass , Conservação de Alimentos/métodos , Armazenamento de Alimentos/métodos , Gases em Plasma/química , Alimentos Marinhos/análise , Animais , Argônio/análise , Bass/microbiologia , Dióxido de Carbono/análise , Qualidade dos Alimentos , Oxigênio/análise , Alimentos Marinhos/microbiologia
20.
Surgery ; 168(1): 178-184, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32223983

RESUMO

BACKGROUND: Fluorescence-based enhanced reality is a software that provides quantitative fluorescence angiography by computing the fluorescence intensity time-to-peak after intravenous indocyanine green. Hyperspectral imaging is a contrast-free, optical imaging modality which measures tissue oxygenation. METHODS: In 8 pigs, an ischemic bowel segment created by dividing the arcade branches was imaged using hyperspectral imaging and fluorescence-based enhanced reality. Tissue oxygenation values were acquired through a hyperspectral imaging system. Subsequently, fluorescence angiography was performed using a near-infrared laparoscopic camera after intravenous injection of 0.2 mg/kg of indocyanine green. The time-to-peak fluorescence signal was analyzed through a proprietary software to realize a perfusion map. This was overlaid onto real-time images to obtain fluorescence-based enhanced reality. Simultaneously, 9 adjacent regions of interest were selected and superimposed onto the real-time video, thereby obtaining hyperspectral-based enhanced reality. Fluorescence-based enhanced reality and hyperspectral-based enhanced reality were superimposed allowing a comparison of both imaging modalities. Local capillary lactate levels were sampled at the regions of interest. Two prediction models using the local capillary lactate levels were extrapolated based on both imaging systems. RESULTS: For all regions of interest, the mean local capillary lactate levels were 4.67 ± 4.34 mmol/L, the mean tissue oxygenation was 45.9 ± 18.9%, and the mean time-to-peak was 10 ± 9.4 seconds. Pearson's test between fluorescence-based enhanced reality-time-to-peak and hyperspectral imaging-tissue oxygenation at the corresponding regions of interest gave an R = -0.66 (P < .0001). The hyperspectral imaging lactate prediction model proved more accurate than the fluorescence-based enhanced reality-based model (P < .0001). CONCLUSION: Bowel perfusion was quantified using hyperspectral imaging and fluorescence angiography. Hyperspectral imaging yielded more accurate results than fluorescence angiography. Hyperspectral-based enhanced reality may prove to be a useful, contrast-free intraoperative tool to quantify bowel ischemia.


Assuntos
Angiofluoresceinografia , Verde de Indocianina , Enteropatias/diagnóstico por imagem , Isquemia/diagnóstico por imagem , Imagem Óptica/métodos , Animais , Ácido Láctico/análise , Masculino , Oxigênio/análise , Suínos
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