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1.
Acta Odontol Scand ; 78(1): 31-37, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31349769

RESUMO

Objectives: To determine the baseline perfusion parameters of the alveolar mucosa using laser Doppler flowmetry and tissue spectrophotometry (LDF-TS) in healthy adults.Material and methods: Forty-two healthy adult subjects of either sex were tested. The perfusion of the alveolar mucosa was evaluated using a laser Doppler flowmetry and tissue spectrophotometry using O2C 'oxygen to see' device. The measurements encompassed the maxillary and mandibular mucosa at 20 different points.Results: The O2C device is a reliable method for noninvasive measurement of different perfusion parameters of the oral mucosa. The hemoglobin saturation values (So2 in %), as well as relative amount of hemoglobin in arbitrary units (AU) of the maxillary mucosa demonstrated lower values of that in the mandible. The flow value (AU) exhibited a significant difference in the posterior molar region only, while the velocity value (AU) showed a significant difference across all points except for the anterior region.Conclusion: the present study provides a set of brand-new perfusion parameters of the microcirculation of the alveolar mucosa using LDF-TS. The study suggests a variation of the perfusion parameters between the maxilla and the mandible. Differences in the anatomy of the blood supply, the thickness of the mucosa and the cortical bone, may be attributed to this variation. Further studies using different probes and a combination of ultrasonic measurements and SDF imaging will aid in giving a better overview of the perfusion in the oral mucosa.


Assuntos
Fluxometria por Laser-Doppler/métodos , Mandíbula/irrigação sanguínea , Maxila/irrigação sanguínea , Microcirculação/fisiologia , Mucosa Bucal/irrigação sanguínea , Oxigênio/fisiologia , Espectrofotometria/métodos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Perfusão
2.
Adv Exp Med Biol ; 1185: 413-417, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31884647

RESUMO

The retina is one of the tissues with the highest metabolic activity in the body, and the energy-demanding photoreceptors require appropriate oxygen levels for photo- and neurotransduction. Accumulating evidence suggests that age-related changes in the retina may reduce oxygen supply to the photoreceptors and trigger a chronic hypoxic response. A detailed understanding of the molecular response to hypoxia is crucial, as hindered oxygen delivery may contribute to the development and progression of retinal pathologies such as age-related macular degeneration (AMD). Important factors in the cellular response to hypoxia are microRNAs (miRNAs), which are small, noncoding RNAs that posttranscriptionally regulate gene expression by binding to mRNA transcripts. Here, we discuss the potential role of hypoxia-regulated miRNAs in connection to retinal pathologies.


Assuntos
Hipóxia/patologia , MicroRNAs/genética , Oxigênio/fisiologia , Retina/patologia , Envelhecimento , Humanos , Degeneração Macular/patologia , Doenças Retinianas/patologia
3.
Br J Radiol ; 92(1103): 20190198, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31538514

RESUMO

OBJECTIVE: Radiation therapy is among the most effective and widely used modalities of cancer therapy in current clinical practice. In this era of personalized radiation medicine, high-throughput data now provide the means to investigate novel biomarkers of radiation response. Large-scale efforts have identified several radiation response signatures, which poses two challenges, namely, their analytical validity and redundancy of gene signatures. METHODS: To address these fundamental radiogenomics questions, we curated a database of gene expression signatures predictive of radiation response under oxic and hypoxic conditions. RadiationGeneSigDB has a collection of 11 oxic and 24 hypoxic signatures with the standardized gene list as a gene symbol, Entrez gene ID, and its function. We present the utility of this database by gaining an understanding of hypoxia-associated miRNA by applying a penalized multivariate model; by comparing breast cancer oxic signatures in cell line data vs patient data; and by comparing the similarity of head and neck cancer hypoxia signatures at the pathway level in clinical tumour data. RESULTS: We obtained a set of miRNA highly associated both positively and negatively to the hypoxia gene signatures, across pan-cancer. In addition, we identified moderate correlations between breast cancer oxic signatures in patient data, and significant differences across molecular subtypes. Moreover, we also found that different set of pathways to be enriched using the head and neck hypoxia signatures, although, they are found to be concordant when applied on the patient data. CONCLUSION: This valuable, curated repertoire of published gene expression signatures provides motivating case studies for how to search for similarities in radiation response for tumours arising from different tissues across model systems under oxic and hypoxic conditions, and how a well-curated set of gene signatures can be used to generate novel biological hypotheses about the functions of non-coding RNA. ADVANCES IN KNOWLEDGE: We envision that RadiationSigDB database will help accelerate preclinical radiotherapeutic discovery pipelines in terms of analytical validity of novel biomarkers of radiation response and the need for ensemble approaches to clinical genomic biomarkers.


Assuntos
Neoplasias da Mama/genética , Bases de Dados Factuais , Neoplasias de Cabeça e Pescoço/genética , MicroRNAs/genética , Transcriptoma/genética , Pesquisa Biomédica , Neoplasias da Mama/radioterapia , Marcadores Genéticos/genética , Neoplasias de Cabeça e Pescoço/radioterapia , Humanos , Hipóxia/genética , Oxigênio/fisiologia , Células Tumorais Cultivadas
4.
An Acad Bras Cienc ; 91(3): e20180395, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31432900

RESUMO

The aquatic environment presents daily and/or seasonal variations in dissolved oxygen (DO) levels. Piava faces different DO levels in the water due to its distributional characteristics. The goal of this study was to describe the effects of low DO levels on plasma ion, biochemical and oxidative variables in piava juveniles. Fish were exposed to different DO levels, including 1.0, 2.0, 3.0, 4.0 and 5.0 mg L-1 of DO for 96 h, after which blood and tissue samples (liver, kidney, gill and muscle) were collected. The decrease in DO levels decreased plasma Na+, Cl-, K+ and NH3 levels as well as protein and glycogen levels in the liver, kidney and muscle; increased Na+/K+-ATPase activity in the gills and kidney as well as glucose and ammonia levels in the liver, kidney and muscle; and increased lactate levels in the kidney and muscle. Thiobarbituric acid-reacting substances, catalase and non-protein thiol levels decreased in the tissues of piavas exposed to low DO levels. It is concluded that piava can apparently cope with hypoxic conditions; however, low DO levels are a stressor, and the tolerance of piava to hypoxia involves iono-regulatory, metabolic and oxidative adjustments.


Assuntos
Adaptação Fisiológica/fisiologia , Caraciformes/fisiologia , Estresse Oxidativo/fisiologia , Oxigênio/fisiologia , Animais , Catalase/metabolismo , Caraciformes/metabolismo , Ácido Láctico/metabolismo , Oxigênio/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Superóxido Dismutase/metabolismo
5.
Zebrafish ; 16(5): 434-442, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31314708

RESUMO

Strategies to reduce reperfusion injury after ischemia have been considered in clinical practice, but few interventions have successfully passed the proof-of-concept stage. In this study, we developed a novel zebrafish larvae hypoxia/reoxygenation (H/R) model to simulate myocardial ischemia/reperfusion injury (MIRI), with potential utility as a drug screening tool. After H/R treatment, videos of transgenic [Tg(cmlc:EGFP)] larval zebrafish hearts were captured using a digital high-speed camera, and the heart rate, diastolic area, systolic area, and total fraction of area changed were quantified. The mRNA expression of tnnt2, bnp, and hif1α was quantified, and red blood cells (RBCs) were detected by O-dianisidine staining. We found that a decline in cardiac contractility occurred in zebrafish larvae 48 h after hypoxia treatment. Reoxygenation for 2-5 h after 48 h of hypoxia caused heart dysfunction in zebrafish larvae, and were determined to be the optimum conditions for simulating MIRI similar to mammalian models. Our results indicated that heart dysfunction after reoxygenation in zebrafish larvae was accompanied by an upregulated gene expression of a number of myocardial injury biomarkers and increased numbers of RBCs. In conclusion, the novel larval zebrafish H/R model developed in this study could be used for rapid in vivo screening and efficacy assessment of MIRI therapeutics.


Assuntos
Contração Miocárdica/fisiologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Oxigênio/fisiologia , Animais , Animais Geneticamente Modificados , Proteínas de Fluorescência Verde/metabolismo , Hipóxia , Larva/fisiologia , Peixe-Zebra
6.
An Acad Bras Cienc ; 91 Suppl 3: e20190260, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31166477

RESUMO

The Amazon basin houses a particular group of freshwater organisms, whose study tells the geological history of the region, how biological diversity was shaped, how it is maintained, and what it hides. The fish of the Amazon is represented by more than 3,000 known species distributed from the basal groups up to the more specialized ones. This species richness hides a diversity of adaptations that are dispersed at all levels of the biological organization. In this summary of the conference delivered at the Brazil-France Bilateral Symposium, held in Manaus in 2018, we describe two aspects of the hidden world of adaptive diversity: adaptations to changes in dissolved oxygen and the abilities of the Rio Negro fish to face acidic and ion-poor waters of their habitats. Also, we present the vulnerability of Amazonian fish to ongoing climate changes. Then, very briefly, we call attention to the many hidden biological processes that allow these fish species to survive their environments, much of which is unknown. Indeed, however, they are intricately related to men, either by responding to environmental disturbances that we have caused, or by containing information that contributes to improving the quality of the environment in which we live.


Assuntos
Adaptação Fisiológica/fisiologia , Biodiversidade , Ecossistema , Peixes/fisiologia , Oxigênio/fisiologia , Animais , Brasil , Mudança Climática , Peixes/classificação , Água Doce
7.
PLoS One ; 14(5): e0216938, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31091280

RESUMO

This paper aims to develop a novel computational technique for the detection of the transit through the anaerobic threshold. This technique uses only cardiac intervals derived from the electrocardiogram and is based on algebraic relationships between RR and QRS intervals. Electrocardiograms are measured during the load and the recovery processes. Algebraic relationships between cardiac intervals are used not only to identify the anaerobic threshold but also to characterise individual features of the person during the transit through the threshold. The ratio between carbon dioxide and oxygen in the exhaled air is used to validate the results. The algebraic relationship between cardiac intervals serves as a stand-alone indicator for both the determination of the anaerobic threshold and the characterization of the performance of the person during the load and the recovery processes.


Assuntos
Algoritmos , Limiar Anaeróbio/fisiologia , Eletrocardiografia/estatística & dados numéricos , Coração/fisiologia , Adulto , Dióxido de Carbono/fisiologia , Teste de Esforço , Expiração/fisiologia , Voluntários Saudáveis , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Oxigênio/fisiologia
9.
Sci Total Environ ; 666: 1071-1079, 2019 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-30970473

RESUMO

To study adaptation of largemouth bass (Micropterus salmoides) to hypoxic stress, we investigated physiological responses and lactate metabolism of the fish under acute hypoxia. The objectives of this study were to (a) observe changes in glucose, glycogen, and lactate content; (b) detect the activity of lactate dehydrogenase (LDH) in serum, brain, heart, and liver tissues; and (c) quantify the dynamic gene expression of AMP activated protein kinase alpha (AMPKα), hypoxia-inducible factor-1 alpha (HIF-1α), monocarboxylate transporter 1 (MCT1), monocarboxylate transporter 4 (MCT4), and lactate dehydrogenase-a (LDHa) following exposure to hypoxia. The fish were subjected to two hypoxia stresses (dissolved oxygen [DO] 1.20 ±â€¯0.2 mg/L and 3.50 ±â€¯0.3 mg/L, respectively) for 24 h. Our results showed that hypoxic stress significantly increased the decomposition of liver glycogen and significantly increased the concentration of blood glucose; however, the muscle glycogen content was not significantly decreased, which indicates that liver glycogen was the main energy source under acute hypoxia. Moreover, hypoxia led to accumulation of a large amount of lactic acid in tissues, possibly due to the activity of lactic acid dehydrogenase, but this process was delayed in the heart and brain relative to the liver. Additionally, hypoxia induced the expression of AMPKα, HIF-1α, MCT1, MCT4, and LDHa, suggesting that glycometabolism had switched from aerobic to anaerobic. Our results contribute to a better understanding of the molecular mechanisms of the response to hypoxia in largemouth bass.


Assuntos
Proteínas Quinases Ativadas por AMP/genética , Bass/fisiologia , Proteínas de Peixes/genética , Ácido Láctico/metabolismo , Oxigênio/fisiologia , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Proteínas de Peixes/metabolismo , Estresse Fisiológico
10.
Gene ; 704: 42-48, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30980943

RESUMO

Angiogenesis is recognized as a sign of cancer and facilitates cancer progression and metastasis. Suppression of angiogenesis is a desirable strategy for gastric cancer (GC) management. In this study, we showed a novel role of gastrin in angiogenesis of GC. We observed that treatment with gastrin 17 (G17) increased the proliferation of AGS cells and enhanced tube formation during normoxia and hypoxia. The expression level of VEGF were increased by G17 treatment as well. Experiments on the mechanism showed that G17 promoted HIF-1α expression, which subsequently enhanced ß-catenin nuclear localization and activation of TCF3 and LEF1 and finally resulted in angiogenesis by upregulating VEGF. An in vivo experiment confirmed that G17 enhanced GC cell proliferation and angiogenesis in the resultant tumor. In conclusion, our findings indicate that gastrin promotes angiogenesis via activating HIF-1α/ß-catenin/VEGF axis in GC.


Assuntos
Gastrinas/farmacologia , Neovascularização Patológica/induzido quimicamente , Neoplasias Gástricas/irrigação sanguínea , Neoplasias Gástricas/patologia , Animais , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Células Cultivadas , Gastrinas/fisiologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/fisiologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Oxigênio/farmacologia , Oxigênio/fisiologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Neoplasias Gástricas/genética , Hipóxia Tumoral/efeitos dos fármacos , Hipóxia Tumoral/genética , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , beta Catenina/genética , beta Catenina/metabolismo
11.
Clin Hemorheol Microcirc ; 71(4): 387-396, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31006676

RESUMO

Physiological modifications of blood rheology during pregnancy and their alterations in pregnant hypertensive women have been extensively studied in the 1980's. Since vascular resistance is higher in hypertensive pregnant women whose newborns are small-for gestational-age (SGA), we investigated in a personal database if growth retardation of newborns is related to the oxygen delivery index (ratio hematocrit/blood viscosity) and to the difference between hematocrit (Hct) and the prediction of its optimal valued based on Quemada's equation. A sample of 38 hypertensive pregnant women (age 29 yr±1) was compared with 64 controls matched for age and gestational age, studied at 35±1 weeks gestation, extracted from a larger series of 162 pregnant women. On the whole the hypertensive group gave birth to smaller children (p = 0.014). Plasma viscosity correlated with blood pressure (BP) only in hypertensive women (r = 0.403 p < 0.05). The bell-shaped curve of predicted optimal Hct of non hypertensive pregnant women was similar to that of non-pregnant women, but in hypertensive women it was shifted toward higher values (p = 0.07), and the predicted optimal Hct (but not the actual one) was correlated with systolic blood pressure (SBP) (r = 0.349 p < 0.001) and diastolic blood pressure (DBP) (r = 0.218 p < 0.05). The predicted optimal Hct/viscosity (h/η) ratio was higher in hypertensive women whose newborns exhibited a low birth weight (p = 0.03), resulting in a higher discrepancy between actual and model-predicted «ideal¼ values of h/η ratio (p = 0.03) and Hct (p = 0.02) compared with the subgroup with no growth retardation. Therefore, in hypertensive women whose newborns exhibited a low birth weight, hemorheological parameters predicting oxygen supply are shifted to lower values than predicted by the model.


Assuntos
Pressão Sanguínea/fisiologia , Viscosidade Sanguínea/fisiologia , Retardo do Crescimento Fetal/fisiopatologia , Hematócrito/métodos , Hemorreologia/fisiologia , Hipertensão/fisiopatologia , Oxigênio/fisiologia , Adulto , Feminino , Humanos , Recém-Nascido , Gravidez
12.
Nat Commun ; 10(1): 1140, 2019 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-30850610

RESUMO

Accurate estimates of the BOLD hemodynamic response function (HRF) are crucial for the interpretation and analysis of event-related functional MRI data. To date, however, there have been no comprehensive measurements of the HRF in white matter (WM) despite increasing evidence that BOLD signals in WM change after a stimulus. We performed an event-related cognitive task (Stroop color-word interference) to measure the HRF in selected human WM pathways. The task was chosen in order to produce robust, distributed centers of activity throughout the cortex. To measure the HRF in WM, fiber tracts were reconstructed between each pair of activated cortical areas. We observed clear task-specific HRFs with reduced magnitudes, delayed onsets and prolonged initial dips in WM tracts compared with activated grey matter, thus calling for significant changes to current standard models for accurately characterizing the HRFs in WM and for modifications of standard methods of analysis of functional imaging data.


Assuntos
Córtex Cerebral/fisiologia , Substância Cinzenta/fisiologia , Rede Nervosa/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Substância Branca/fisiologia , Adulto , Córtex Cerebral/diagnóstico por imagem , Circulação Cerebrovascular/fisiologia , Feminino , Substância Cinzenta/diagnóstico por imagem , Voluntários Saudáveis , Hemodinâmica/fisiologia , Hemoglobinas/análise , Hemoglobinas/fisiologia , Humanos , Imagem por Ressonância Magnética , Masculino , Rede Nervosa/diagnóstico por imagem , Oxigênio/análise , Oxigênio/fisiologia , Teste de Stroop , Substância Branca/diagnóstico por imagem
13.
Ecotoxicol Environ Saf ; 173: 436-443, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-30798187

RESUMO

This study investigated the effect of microcystin-LR (MC-LR) on in vivo cardiorespiratory function and on tissue biomarkers of oxidative stress in gills and liver of the trahira, a neotropical freshwater fish. Trahira were treated with an intraperitoneal injection of 100 µg MC-LR.kg-1 body mass or a saline, with the toxic effects of MC-LR then evaluated after 48 h. Rates of oxygen uptake (V̇O2) did not differ significantly between Control and the exposed group (Mcys), but exposure to MC-LR significantly reduced O2 extraction in the Mcys group at all O2 tensions. This was associated with higher gill ventilation volume (V̇G) in the Mcys group at all O2 tensions except 140 and 120 mmHg, and a higher tidal volume (VT) of the Mcys group at all tensions except 140 mmHg. Heart rate was also higher in the Mcys group, significantly so at an O2 tension of 40 mmHg. In the liver of trahira, exposure to MC-LR has significant effects on antioxidant defense systems, inducing a significant increase in the activity of the (GPx) glutathione peroxidase enzyme (100%) and in the reduced glutathione (GSH) content (70%) compared to the control group, but no effects on superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) enzymes. The liver showed no oxidative damage, when measured as lipid peroxidation (LPO) levels and protein carbonyl (PC) content. In the gills SOD and GPx enzyme activity increased significantly in the Mcys group (98% and 73% respectively) compared to the controls, although GSH, CAT and GST did not differ between groups. There was also no significant difference in GSH in this tissue. Levels of lipid peroxidation in the gills were 53% higher in the Mcys group, although carbonyl protein levels did not differ. In conclusion, these data show that MC-LR leads to development of hyperventilation and increased activity of the detoxification system and that this species was able to compensate the deleterious effects of microcystin on its vital functions. The antioxidant defense in the liver was able to contain the propagation of LPO and prevent the oxidation of proteins, although the gills of the fishes exposed to MC-LR were not able to contain the formation of reactive oxygen species and LPO, which led to the establishment of oxidative stress which impaired gill function.


Assuntos
Caraciformes/fisiologia , Microcistinas/toxicidade , Animais , Catalase/metabolismo , Proteínas de Peixes/metabolismo , Brânquias/efeitos dos fármacos , Brânquias/fisiologia , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Transferase/metabolismo , Frequência Cardíaca/efeitos dos fármacos , Inativação Metabólica , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Oxigênio/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo
14.
Artigo em Inglês | MEDLINE | ID: mdl-30654519

RESUMO

The aim was to analyze the effects of cardiorespiratory exercise and air pollution on cognition and cardiovascular markers in four groups of older women: the active/clean air group (AC), the active/polluted air group (AP), the sedentary/clean air group (SC), and the sedentary/polluted air group (SP). Active groups performed a training task based on progressive walking. Prior to and after the experiment, the following parameters were assessed: cognition, by Mini Mental State Examination (MMSE); maximum oxygen uptake (VO2max), estimated by the Six-Minute Walk Test (6mWT); heart rate (HR); and oxygen saturation (SpO2). There were significant differences (p < 0.05) between the AC and the SP in all the MMSE dimensions except "Registration", and in all the physiological variables (VO2max, SpO2, HR). Aerobic exercise may be a protective factor against the effects that pollution have on cognition and on the mechanisms of oxygen transport.


Assuntos
Poluição do Ar , Cognição , Exposição Ambiental , Exercício Físico/fisiologia , Idoso , Teste de Esforço , Feminino , Frequência Cardíaca , Humanos , Oxigênio/fisiologia , Consumo de Oxigênio/fisiologia
15.
Fish Physiol Biochem ; 45(2): 657-665, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30607683

RESUMO

Factor-inhibiting HIF-1 (FIH-1) is an asparagine hydroxylase that interacts with hypoxia-inducible factor 1α (HIF-1α) to regulate transcriptional activity of HIF-1. Few studies of fish FIH-1 have been reported to date. In this study, the cDNA of FIH-1 gene was cloned and characterized for bighead carp, Aristichthys nobilis (AnFIH-1). The AnFIH-1 cDNA is 2065 bp in length, encoding a protein of 357 amino acid (aa) residues, which contains a JmjC homology region of the jumonji transcription factors. AnFIH-1 shares high identities with other vertebrate FIH-1 (79.1-96.4%), especially in the JmjC homology region, suggesting its conserved function. During the embryonic stages of A. nobilis, AnFIH-1 had significantly high expression levels in unfertilized egg and blastula. In healthy tissues, its predominant mRNA expression was detected in muscle. The mRNA levels of AnFIH-1 were significantly upregulated in the liver, gill, hypothalamus, and spleen after hypoxic treatment, and then decreased to pretreatment levels after 6-h re-oxygenation. However, in the muscle, continual increasing of mRNA expression was observed after hypoxic shock and re-oxygenation. These results indicate that FIH-1 may play an important role in physiological regulation for adapting to hypoxia stress in A. nobilis.


Assuntos
Cyprinidae/metabolismo , Regulação da Expressão Gênica/fisiologia , Fator 1 Induzível por Hipóxia/metabolismo , Oxigênio/fisiologia , Estresse Fisiológico/fisiologia , Sequência de Aminoácidos , Animais , Clonagem Molecular , Fator 1 Induzível por Hipóxia/genética
16.
Plast Reconstr Surg ; 143(4): 848e-856e, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30676507

RESUMO

BACKGROUND: In the diabetic foot, the skin may crack and develop fissures, potentially increasing vulnerability to ulceration and infection. Therefore, maintaining adequate skin hydration may be crucial for diabetic wound healing. However, no clinical study has addressed this issue. This study aimed to determine and compare the effect of the skin hydration level on diabetic wound healing with that of the tissue oxygenation level, which is recognized as the most reliable parameter in predicting diabetic wound healing. METHODS: This retrospective study included 263 diabetic patients with forefoot ulcers. Skin hydration and transcutaneous oxygen pressure data collected before and after percutaneous transluminal angioplasty were analyzed. Skin hydration and tissue oxygenation were graded as poor, moderate, or acceptable. Wound healing outcomes were graded as healed without amputation, minor amputation, or major amputation. Wound healing outcomes were compared using four parameters: skin hydration at baseline, transcutaneous oxygen pressure at baseline, post-percutaneous transluminal angioplasty skin hydration, and post-percutaneous transluminal angioplasty transcutaneous oxygen pressure. RESULTS: Each of the four parameters exhibited statistically significant correlations with wound healing outcomes. In the concurrent analysis of both skin hydration and transcutaneous oxygen pressure, skin hydration was a dominant parameter (p = 0.0018) at baseline, whereas transcutaneous oxygen pressure was a dominant parameter (p < 0.0001) following percutaneous transluminal angioplasty. CONCLUSIONS: Skin hydration level might be a useful predictor for diabetic wound healing. In particular, the skin hydration level before recanalization was found to be superior to transcutaneous oxygen pressure in predicting wound healing. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.


Assuntos
Pé Diabético/fisiopatologia , Estado de Hidratação do Organismo/fisiologia , Fenômenos Fisiológicos da Pele , Cicatrização/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Amputação/estatística & dados numéricos , Angioplastia/estatística & dados numéricos , Pé Diabético/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oxigênio/fisiologia , Estudos Retrospectivos , Stents , Resultado do Tratamento
17.
J Plant Physiol ; 234-235: 60-70, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30665049

RESUMO

Gibberellins are central to the regulation of plant development and growth. Action of gibberellins involves the degradation of DELLA proteins, which are negative regulators of growth. In barley (Hordeum vulgare), certain mutations affecting genes involved in gibberellin synthesis or coding for the barley DELLA protein (Sln1) confer dwarfism. Recent studies have identified new alleles of Sln1 with the capacity to revert the dwarf phenotype back to the taller phenotypes. While the effect of these overgrowth alleles on shoot phenotypes has been explored, no information is available for roots. Here, we examined aspects of the root phenotypes displayed by plants with various Sln1 gene alleles, and tested responses to growth in an O2-deficient root-zone as occurs during soil waterlogging. One overgrowth line, bearing the Sln1d.8 allele carrying two amino acid substitutions (one in the amino terminus and one in the GRAS domain of the encoded DELLA protein), displays profound and opposite effects on shoot height and root length. While it stimulates shoot height, it severely compromises root length by a reduction of cell size in zones distal to the root apex. In addition, Sln1d.8 plants counteract the negative effect of the original mutation on the formation of adventitious roots. Interestingly, plants bearing this allele display enhanced resistance to flooding stress in a way non-related with increased root porosity. Thus, various Sln1 gene alleles contribute to root phenotypes and can also influence plant responses to root-zone O2-deficiency stress.


Assuntos
Aclimatação , Hordeum/genética , Proteínas de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Estresse Fisiológico , Biomassa , Giberelinas/metabolismo , Hordeum/crescimento & desenvolvimento , Hordeum/metabolismo , Mutação , Oxigênio/fisiologia , Folhas de Planta/crescimento & desenvolvimento , Brotos de Planta/crescimento & desenvolvimento
18.
Br J Anaesth ; 122(1): 86-91, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30579411

RESUMO

BACKGROUND: Obstetric airway guidelines recommend preoxygenation in preparation for general anaesthesia to achieve end-tidal oxygen concentrations (etO2) of ≥90%, and mention the potential use of high-flow humidified nasal oxygen (HFNO). We investigated the new HFNO technique (Optiflow™) in term pregnant women. METHODS: Seventy-three term participants underwent a 3 min HFNO protocol (30 L min-1 for 30 s, and then 50 L min-1 for 150 s). The etO2 was assessed for the first four breaths after simulated preoxygenation. The primary outcome was the proportion who achieved etO2 ≥90% for the first expired breath. The secondary outcomes were the proportion who achieved etO2 ≥80%; fetal heart rate before and after the test; the association of body mass index (BMI) to etO2 achieved with preoxygenation; and comfort levels of, and preference for, nasal and face mask preoxygenation. RESULTS: The proportion with first expired breath etO2 ≥90% was 60% [95% confidence interval (CI): 54-66%] and etO2 ≥80% was 84% (95% CI: 80-88%). There was no change in fetal heart rate from before to after the test (P=0.34). There was a negative association of BMI to etO2 achieved with preoxygenation (Pearson correlation: -0.26; P=0.027). There was no difference in comfort scores between nasal cannula and face mask (P=0.40). Forty-one (56%; 95% CI: 35-47%) women preferred the nasal cannula to the face mask. CONCLUSIONS: HFNO using this protocol is inadequate to preoxygenate term pregnant women. Despite encouraging results in the literature reporting results in non-pregnant women, further work is required before justifying its use in pregnant women. CLINICAL TRIAL REGISTRATION: ACTRN 12616000531415p.


Assuntos
Manuseio das Vias Aéreas/métodos , Anestesia Obstétrica/métodos , Oxigenoterapia/métodos , Adulto , Anestesia Geral/métodos , Cânula , Feminino , Humanos , Máscaras , Oxigênio/fisiologia , Gravidez , Estudos Prospectivos , Adulto Jovem
19.
Birth Defects Res ; 110(20): 1517-1530, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30576091

RESUMO

Low oxygen concentration (hypoxia) is part of normal embryonic development, yet the situation is complex. Oxygen (O2 ) is a janus gas with low levels signaling through hypoxia-inducible transcription factor (HIF) that are required for development of fetal and placental vasculature and fetal red blood cells. This results in coupling of fetus and mother around midgestation as a functional feto-placental unit (FPU) for O2 transport, which is required for continued growth and development of the fetus. Defects in these processes may leave the developing fetus vulnerable to O2 deprivation or other stressors during this critical midgestational transition when common septal and conotruncal heart defects (CHDs) are likely to arise. Recent human epidemiological and case-control studies support an association between placental dysfunction, manifest as early onset pre-eclampsia (PE) and increased serum bio-markers, and CHD. Animal studies support this association, in particular those using gene inactivation in the mouse. Sophisticated methods for gene inactivation, cell fate mapping, and a quantitative bio-reporter of O2 concentration support the premise that hypoxic stress at critical stages of development leads to CHD. The secondary heart field contributing to the cardiac outlet is a key target, with activation of the un-folded protein response and abrogation of FGF signaling or precocious activation of a cardiomyocyte transcriptional program for differentiation, suggested as mechanisms. These studies provide a strong foundation for further study of feto-placental coupling and hypoxic stress in the genesis of human CHD.


Assuntos
Hipóxia/embriologia , Troca Materno-Fetal/fisiologia , Oxigênio/metabolismo , Animais , Estudos de Casos e Controles , Modelos Animais de Doenças , Feminino , Feto/fisiopatologia , Idade Gestacional , Cardiopatias Congênitas/etiologia , Humanos , Hipóxia/metabolismo , Hipóxia/fisiopatologia , Camundongos , Oxigênio/fisiologia , Placenta/metabolismo , Placenta/fisiopatologia , Placentação/fisiologia , Pré-Eclâmpsia/etiologia , Gravidez , Cuidado Pré-Natal , Ratos , Transdução de Sinais
20.
Proc Natl Acad Sci U S A ; 115(45): 11555-11560, 2018 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-30348768

RESUMO

We describe a specimen of the basal ornithuromorph Archaeorhynchus spathula from the Lower Cretaceous Jiufotang Formation with extensive soft tissue preservation. Although it is the fifth specimen to be described, unlike the others it preserves significant traces of the plumage, revealing a pintail morphology previously unrecognized among Mesozoic birds, but common in extant neornithines. In addition, this specimen preserves the probable remnants of the paired lungs, an identification supported by topographical and macro- and microscopic anatomical observations. The preserved morphology reveals a lung very similar to that of living birds. It indicates that pulmonary specializations such as exceedingly subdivided parenchyma that allow birds to achieve the oxygen acquisition capacity necessary to support powered flight were present in ornithuromorph birds 120 Mya. Among extant air breathing vertebrates, birds have structurally the most complex and functionally the most efficient respiratory system, which facilitates their highly energetically demanding form of locomotion, even in extremely oxygen-poor environments. Archaeorhynchus is commonly resolved as the most basal known ornithuromorph bird, capturing a stage of avian evolution in which skeletal indicators of respiration remain primitive yet the lung microstructure appears modern. This adds to growing evidence that many physiological modifications of soft tissue systems (e.g., digestive system and respiratory system) that characterize living birds and are key to their current success may have preceded the evolution of obvious skeletal adaptations traditionally tracked through the fossil record.


Assuntos
Aves/anatomia & histologia , Fósseis/anatomia & histologia , Pulmão/anatomia & histologia , Oxigênio/fisiologia , Respiração , Adaptação Fisiológica , Animais , Evolução Biológica , Aves/classificação , Aves/fisiologia , China , Extinção Biológica , Plumas/anatomia & histologia , Plumas/fisiologia , Voo Animal/fisiologia , Fósseis/história , História Antiga , Pulmão/fisiologia , Filogenia
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