Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 237
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
J Ultrasound Med ; 43(8): 1441-1448, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38700100

RESUMO

PURPOSE: To evaluate changes in dynamic cerebral autoregulation (CA) during short-term and long-term exposure to high altitude with ultrasonography, and also study the sex differences in the response of CA to altitude. METHODS: We assessed the differences in dynamic CA and measured with Doppler ultrasound of the bilateral internal carotid artery (ICA), vertebral artery (VA), and middle cerebral artery (MCA) and the values of basic information within 48 hours and at 2 years after arrival at Tibet in 65 healthy Han young Chinese volunteers, meanwhile, we compared the resistance index (RI) and pulsatility index (PI) of the right MCA at inhale oxygen 8 minutes when a newcomer with 2 years after arrival at Tibet. RESULTS: With 2 years of altitude exposure, the SaO2 of all subjects was above 90%, the mean PEF, DAP, and HR values decreased, HGB increased compared within 48 hours in same-gender groups. Comparisons of cerebral hemodynamics between before 2 years and after 2 years within male and female groups, the mean RI and PI values of bilateral MCA after 2 years were significantly higher than before 2 years, at the same time, the mean RI and PI values of bilateral ICA were significant differences (P < .05) between male groups, with regard to female groups, showed that the mean RI and PI values of bilateral VA were significant differences (P < .05). Comparisons of Right MCA hemodynamics between after oxygen uptake 8 minutes and 2 years, the mean RI and PI values were no significant difference within male and female groups (P > .05). CONCLUSIONS: Acute mountain sickness could result from an alteration of dynamic autoregulation of cerebral blood flow, but the impaired autoregulation may be corrected with the extension of time, furthermore, the response of CA to altitude in males and females are different.


Assuntos
Altitude , Circulação Cerebrovascular , Homeostase , Artéria Cerebral Média , Humanos , Masculino , Feminino , Homeostase/fisiologia , Circulação Cerebrovascular/fisiologia , Adulto Jovem , Adulto , Artéria Cerebral Média/diagnóstico por imagem , Artéria Cerebral Média/fisiologia , Artéria Cerebral Média/fisiopatologia , Artéria Carótida Interna/diagnóstico por imagem , Artéria Carótida Interna/fisiologia , Artéria Vertebral/diagnóstico por imagem , Artéria Vertebral/fisiologia , Artéria Vertebral/fisiopatologia , Valores de Referência , Fatores Sexuais , Fatores de Tempo
2.
J Coll Physicians Surg Pak ; 34(5): 617-619, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38720227

RESUMO

This cross-sectional study was aimed to compare insulin resistance, Triglyceride- Glucose (TyG) index, fatty liver index (FLI) and hepatic steatosis index (HSI), glycaemic and lipids among groups/quartiles based upon estimated Glucose Disposal Rate (eGDR) from August 2022 to December 2022 among 249 male participants. The eGDR results in (mg/kg/min) were divided into four quartiles as: Group-I: {<6.88, n = 62}, Group-II: {<6.88-9.45, n = 63}, Group-III: {9.46-10.39, n = 62}, and Group-IV: {>10.39, n = 62}. Fasting plasma glucose (FPG), HbA1c, low density lipoprotein (LDL), homeostasis model assessment for insulin-resistance (HOMAIR), and TyG index demonstrated significant worsening increase from high to low eGDR groups. Receiver operating curve (ROC) analysis to calculate area under curve (AUC) for diagnostic efficiency candidate indices for eGDR demonstrated highest AUC for FLI as AUC: 0.736 (95% CI: 0.669-0.803), p < 0.001, followed by FPG: AUC: 0.682 (95% CI: 0.606-0.757), HOMAIR: AUC: 0.670 (95% CI: 0.602-0.739), HSI: AUC: 0.660 (95% CI: 0.589-0.731), TyG index: 0.658 (95% CI: 0.583-0.732), and HbA1c: 0.639 (95% CI: 0.583-0.732). Glycaemic measures, lipid indices, insulin resistance and TyG index deteriorated with declining eGDR. Diagnostic performance as evaluated by AUC for eGDR was highest for FLI, followed by FPG, HOMAIR, HSI, TyG index, HbA1c, and triglycerides. Key Words: Triglyceride, Insulin, Glucose, Diabetes.


Assuntos
Glicemia , Homeostase , Resistência à Insulina , Triglicerídeos , Humanos , Resistência à Insulina/fisiologia , Masculino , Triglicerídeos/sangue , Estudos Transversais , Glicemia/metabolismo , Homeostase/fisiologia , Adulto , Pessoa de Meia-Idade , Fígado Gorduroso/diagnóstico , Fígado Gorduroso/sangue , Hemoglobinas Glicadas/metabolismo , Hemoglobinas Glicadas/análise
3.
Exp Physiol ; 109(4): 614-623, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38376110

RESUMO

The mean flow index-usually referred to as Mx-has been used for assessing dynamic cerebral autoregulation (dCA) for almost 30 years. However, concerns have arisen regarding methodological consistency, construct and criterion validity, and test-retest reliability. Methodological nuances, such as choice of input (cerebral perfusion pressure, invasive or non-invasive arterial pressure), pre-processing approach and artefact handling, significantly influence mean flow index values, and previous studies correlating mean flow index with other established dCA metrics are confounded by inherent methodological flaws like heteroscedasticity, while the mean flow index also fails to discriminate individuals with presumed intact versus impaired dCA (discriminatory validity), and its prognostic performance (predictive validity) across various conditions remains inconsistent. The test-retest reliability, both within and between days, is generally poor. At present, no single approach for data collection or pre-processing has proven superior for obtaining the mean flow index, and caution is advised in the further use of mean flow index-based measures for assessing dCA, as current evidence does not support their clinical application.


Assuntos
Pressão Arterial , Circulação Cerebrovascular , Humanos , Reprodutibilidade dos Testes , Homeostase/fisiologia , Circulação Cerebrovascular/fisiologia , Velocidade do Fluxo Sanguíneo/fisiologia , Ultrassonografia Doppler Transcraniana , Pressão Sanguínea/fisiologia
4.
Ann Hepatol ; 29(2): 101167, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37802415

RESUMO

INTRODUCTION AND OBJECTIVES: Acute liver failure, also known as fulminant hepatic failure (FHF), includes a spectrum of clinical entities characterized by acute liver injury, severe hepatocellular dysfunction and hepatic encephalopathy. The objective of this study was to assess cerebral autoregulation (CA) in 25 patients (19 female) with FHF and to follow up with seventeen of these patients before and after liver transplantation. PATIENTS AND METHODS: The mean age was 33.8 years (range 14-56, SD 13.1 years). Cerebral hemodynamics was assessed by transcranial Doppler (TCD) bilateral recordings of cerebral blood velocity (CBv) in the middle cerebral arteries (MCA). RESULTS: CA was assessed based on the static CA index (SCAI), reflecting the effects of a 20-30 mmHg increase in mean arterial blood pressure on CBv induced with norepinephrine infusion. SCAI was estimated at four time points: pretransplant and on the 1st, 2nd and 3rd posttransplant days, showing a significant difference between pre- and posttransplant SCAI (p = 0.005). SCAI peaked on the third posttransplant day (p = 0.006). Categorical analysis of SCAI showed that for most patients, CA was reestablished on the second day posttransplant (SCAI > 0.6). CONCLUSIONS: These results suggest that CA impairment pretransplant and on the 1st day posttransplant was re-established at 48-72 h after transplantation. These findings can help to improve the management of this patient group during these specific phases, thereby avoiding neurological complications, such as brain swelling and intracranial hypertension.


Assuntos
Encefalopatia Hepática , Falência Hepática Aguda , Transplante de Fígado , Humanos , Feminino , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Transplante de Fígado/efeitos adversos , Encefalopatia Hepática/diagnóstico por imagem , Encefalopatia Hepática/etiologia , Falência Hepática Aguda/diagnóstico , Falência Hepática Aguda/cirurgia , Falência Hepática Aguda/complicações , Homeostase/fisiologia
5.
Am J Physiol Renal Physiol ; 326(2): F178-F188, 2024 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-37994409

RESUMO

Chronic kidney disease is increasing at an alarming rate and correlates with the increase in diabetes, obesity, and hypertension that disproportionately impact socioeconomically disadvantaged communities. Iron plays essential roles in many biological processes including oxygen transport, mitochondrial function, cell proliferation, and regeneration. However, excess iron induces the generation and propagation of reactive oxygen species, which lead to oxidative stress, cellular damage, and ferroptosis. Iron homeostasis is regulated in part by the kidney through iron resorption from the glomerular filtrate and exports into the plasma by ferroportin (FPN). Yet, the impact of iron overload in the kidney has not been addressed. To test more directly whether excess iron accumulation is toxic to kidneys, we generated a kidney proximal tubule-specific knockout of FPN. Despite significant intracellular iron accumulation in FPN mutant tubules, basal kidney function was not measurably different from wild type kidneys. However, upon induction of acute kidney injury (AKI), FPN mutant kidneys exhibited significantly more damage and failed recovery, evidence for ferroptosis, and increased fibrosis. Thus, disruption of iron export in proximal tubules, leading to iron overload, can significantly impair recovery from AKI and can contribute to progressive renal damage indicative of chronic kidney disease. Understanding the mechanisms that regulate iron homeostasis in the kidney may provide new therapeutic strategies for progressive kidney disease and other ferroptosis-associated disorders.NEW & NOTEWORTHY Physiological iron homeostasis depends in part on renal resorption and export into the plasma. We show that specific deletion of iron exporters in the proximal tubules sensitizes cells to injury and inhibits recovery. This can promote a chronic kidney disease phenotype. Our paper demonstrates the need for iron balance in the proximal tubules to maintain and promote healthy recovery after acute kidney injury.


Assuntos
Injúria Renal Aguda , Proteínas de Transporte de Cátions , Sobrecarga de Ferro , Insuficiência Renal Crônica , Humanos , Rim/metabolismo , Injúria Renal Aguda/genética , Injúria Renal Aguda/metabolismo , Ferro/metabolismo , Sobrecarga de Ferro/metabolismo , Homeostase/fisiologia , Insuficiência Renal Crônica/genética , Insuficiência Renal Crônica/metabolismo
6.
PLoS One ; 18(6): e0287578, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37347763

RESUMO

PURPOSE: Recently, cerebral autoregulation indices based on moving correlation indices between mean arterial pressure (MAP) and cerebral oximetry (NIRS, ORx) or transcranial Doppler (TCD)-derived middle cerebral artery flow velocity (Mx) have been introduced to clinical practice. In a pilot study, we aimed to evaluate the validity of these indices using incremental lower body negative pressure (LBNP) until presyncope representing beginning cerebral hypoperfusion as well as lower body positive pressure (LBPP) with added mild hypoxia to induce cerebral hyperperfusion in healthy subjects. METHODS: Five male subjects received continuous hemodynamic, TCD and NIRS monitoring. Decreasing levels of LBNP were applied in 5-minute steps until subjects reached presyncope. Increasing levels of LBPP were applied stepwise up to 20 or 25 mmHg. Normobaric hypoxia was added until an oxygen saturation of 84% was reached. This was continued for 10 minutes. ORx and Mx indices were calculated using previously described methods. RESULTS: Both Indices showed an increase > 0.3 indicating impaired cerebral autoregulation during presyncope. However, there was no significant difference in Mx at presyncope compared to baseline (p = 0.168). Mean arterial pressure and cardiac output decreased only in presyncope, while stroke volume was decreased at the last pressure level. Neither Mx nor ORx showed significant changes during LBPP or hypoxia. Agreement between Mx and ORx was poor during the LBNP and LBPP experiments (R2 = 0.001, p = 0.3339). CONCLUSION: Mx and ORx represent impaired cerebral autoregulation, but in Mx this may not be distinguished sufficiently from baseline. LBPP and hypoxia are insufficient to reach the upper limit of cerebral autoregulation as indicated by Mx and ORx.


Assuntos
Pressão Arterial , Espectroscopia de Luz Próxima ao Infravermelho , Humanos , Masculino , Pressão Arterial/fisiologia , Projetos Piloto , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Ultrassonografia Doppler Transcraniana/métodos , Circulação Cerebrovascular/fisiologia , Velocidade do Fluxo Sanguíneo/fisiologia , Oximetria , Homeostase/fisiologia , Pressão Sanguínea/fisiologia
7.
Neurocrit Care ; 38(3): 591-599, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36050535

RESUMO

BACKGROUND: Pulse amplitude index (PAx), a descriptor of cerebrovascular reactivity, correlates the changes of the pulse amplitude of the intracranial pressure (ICP) waveform (AMP) with changes in mean arterial pressure (MAP). AMP relies on cerebrovascular compliance, which is modulated by the state of the cerebrovascular reactivity. PAx can aid in prognostication after acute brain injuries as a tool for the assessment of cerebral autoregulation and could potentially tailor individual management; however, invasive measurements are required for its calculation. Our aim was to evaluate the relationship between noninvasive PAx (nPAx) derived from a novel noninvasive device for ICP monitoring and PAx derived from gold standard invasive methods. METHODS: We retrospectively analyzed invasive ICP (external ventricular drain) and non-invasive ICP (nICP), via mechanical extensometer (Brain4Care Corp.). Invasive and non-invasive ICP waveform morphology data was collected in adult patients with brain injury with arterial blood pressure monitoring. The time series from all signals were first treated to remove movement artifacts. PAx and nPAx were calculated as the moving correlation coefficients of 10-s averages of AMP or non-invasive AMP (nAMP) and MAP. AMP/nAMP was determined by calculating the fundamental frequency amplitude of the ICP/nICP signal over a 10-s window, updated every 10-s. We then evaluated the relationship between invasive PAx and noninvasive nPAx using the methods of repeated-measures analysis to generate an estimate of the correlation coefficient and its 95% confidence interval (CI). The agreement between the two methods was assessed using the Bland-Altman test. RESULTS: Twenty-four patients were identified. The median age was 53.5 years (interquartile range 40-70), and intracranial hemorrhage (84%) was the most common etiology. Twenty-one (87.5%) patients underwent mechanical ventilation, and 60% were sedated with a median Glasgow Coma Scale score of 8 (7-15). Mean PAx was 0.0296 ± 0.331, and nPAx was 0.0171 ± 0.332. The correlation between PAx and nPAx was strong (R = 0.70, p < 0.0005, 95% CI 0.687-0.717). Bland-Altman analysis showed excellent agreement, with a bias of - 0.018 (95% CI - 0.026 to - 0.01) and a localized regression trend line that did not deviate from 0. CONCLUSIONS: PAx can be calculated by conventional and noninvasive ICP monitoring in a statistically significant evaluation with strong agreement. Further study of the applications of this clinical tool is warranted, with the goal of early therapeutic intervention to improve neurologic outcomes following acute brain injuries.


Assuntos
Lesões Encefálicas Traumáticas , Lesões Encefálicas , Adulto , Humanos , Pessoa de Meia-Idade , Pressão Intracraniana/fisiologia , Estudos Retrospectivos , Monitorização Fisiológica/métodos , Homeostase/fisiologia , Circulação Cerebrovascular/fisiologia , Lesões Encefálicas Traumáticas/diagnóstico
8.
Cells ; 11(14)2022 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-35883697

RESUMO

Impairments in cerebral autoregulation (CA) are related to poor clinical outcome. Near infrared spectroscopy (NIRS) is a non-invasive technique applied to estimate CA. Our general purpose was to study the clinical feasibility of a previously published 'NIRS-only' CA methodology in a critically ill intensive care unit (ICU) population and determine its relationship with clinical outcome. Bilateral NIRS measurements were performed for 1-2 h. Data segments of ten-minutes were used to calculate transfer function analyses (TFA) CA estimates between high frequency oxyhemoglobin (oxyHb) and deoxyhemoglobin (deoxyHb) signals. The phase shift was corrected for serial time shifts. Criteria were defined to select TFA phase plot segments (segments) with 'high-pass filter' characteristics. In 54 patients, 490 out of 729 segments were automatically selected (67%). In 34 primary neurology patients the median (q1-q3) low frequency (LF) phase shift was higher in 19 survivors compared to 15 non-survivors (13° (6.3-35) versus 0.83° (-2.8-13), p = 0.0167). CA estimation using the NIRS-only methodology seems feasible in an ICU population using segment selection for more robust and consistent CA estimations. The 'NIRS-only' methodology needs further validation, but has the advantage of being non-invasive without the need for arterial blood pressure monitoring.


Assuntos
Circulação Cerebrovascular , Espectroscopia de Luz Próxima ao Infravermelho , Estado Terminal , Estudos Transversais , Homeostase/fisiologia , Humanos , Estudos Prospectivos , Espectroscopia de Luz Próxima ao Infravermelho/métodos
9.
Neurocrit Care ; 36(1): 21-29, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34403122

RESUMO

BACKGROUND: Cerebral autoregulation plays an important role in safeguarding adequate cerebral perfusion and reducing the risk of secondary brain injury, which is highly important for patients in the neurological intensive care unit (neuro-ICU). Although the consensus white paper suggests that a minimum of 5 min of data are needed for assessing dynamic cerebral autoregulation with transfer function analysis (TFA), it remains unknown if the length of these data is valid for patients in the neuro-ICU, of whom are notably different than the general populations. We aimed to investigate the effect of data length using transcranial Doppler ultrasound combined with invasive blood pressure measurement for the assessment of dynamic cerebral autoregulation in patients in the neuro-ICU. METHODS: Twenty patients with various clinical conditions (severe acute encephalitis, ischemic stroke, subarachnoid hemorrhage, brain injury, cerebrovascular intervention operation, cerebral hemorrhage, intracranial space-occupying lesion, and toxic encephalopathy) were recruited for this study. Continuous invasive blood pressure, with a pressure catheter placed at the radial artery, and bilateral continuous cerebral blood flow velocity with transcranial Doppler ultrasound were simultaneously recorded for a length of 10 min for each patient. TFA was applied to derive phase shift, gain, and coherence function at all frequency bands from the first 2, 3, 4, 5, 6, 7, 8, 9, and 10 min of the 10-min recordings in each patient on both hemispheres. The variability in the autoregulatory parameters in each hemisphere was investigated by repeated measures analysis of variance. RESULTS: Forty-one recordings (82 hemispheres) were included in the study. According to the critical values of coherence provided by the Cerebral Autoregulation Research Network white paper, acceptable rates for the data were 100% with a length ≥ 7 min. The final analysis included 68 hemispheres. The effects of data length on trends in phase shift in the very low frequency (VLF) band (F1.801,120.669 = 6.321, P = 0.003), in the LF band (F1.274,85.343 = 4.290, P = 0.032), and in the HF band (F1.391,93.189 = 3.868, P = 0.039) were significant for 3-7 min, for 4-7 min, and for 5-8 min, respectively. Effects were also significant on the gain in the VLF band (F1.927,129.134 = 3.215, P = 0.045) for 2-8 min and on the coherence function in all frequency bands (VLF F2.846,190.671 = 90.247, P < 0.001, LF F2.515,168.492 = 55.770, P < 0.001, HF F2.411, 161.542 = 33.833, P < 0.001) for 2-10 min. CONCLUSIONS: Considering the acceptable rates for the data and the variation in the TFA variables (phase shift and gain), we recommend recording data for a minimum length of 7 min for TFA in patients in the neuro-ICU.


Assuntos
Circulação Cerebrovascular , Ultrassonografia Doppler Transcraniana , Velocidade do Fluxo Sanguíneo/fisiologia , Pressão Sanguínea/fisiologia , Circulação Cerebrovascular/fisiologia , Homeostase/fisiologia , Humanos , Unidades de Terapia Intensiva
10.
J Cereb Blood Flow Metab ; 42(3): 454-470, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34304623

RESUMO

Restoring perfusion to ischemic tissue is the primary goal of acute ischemic stroke care, yet only a small portion of patients receive reperfusion treatment. Since blood pressure (BP) is an important determinant of cerebral perfusion, effective BP management could facilitate reperfusion. But how BP should be managed in very early phase of ischemic stroke remains a contentious issue, due to the lack of clear evidence. Given the complex relationship between BP and cerebral blood flow (CBF)-termed cerebral autoregulation (CA)-bedside monitoring of cerebral perfusion and oxygenation could help guide BP management, thereby improve stroke patient outcome. The aim of INFOMATAS is to 'identify novel therapeutic targets for treatment and management in acute ischemic stroke'. In this review, we identify novel physiological parameters which could be used to guide BP management in acute stroke, and explore methodologies for monitoring them at the bedside. We outline the challenges in translating these potential prognostic markers into clinical use.


Assuntos
Circulação Cerebrovascular/fisiologia , Hemodinâmica/fisiologia , Homeostase/fisiologia , AVC Isquêmico/fisiopatologia , Neuroimagem/métodos , Pressão Sanguínea/fisiologia , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Humanos , AVC Isquêmico/diagnóstico por imagem
11.
Arch Pediatr ; 28(7): 588-593, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34598836

RESUMO

Phosphate homeostasis is a requirement for normal life. Phosphate is involved in the synthesis of membrane lipids, DNA, RNA, and energy-rich molecules (ATP and GTP), and the regulation of protein activity by phosphorylation/dephosphorylation. Moreover, phosphate is a component of apatite crystals, which provide stability to the bone, and is essential for normal growth. Phosphate balance in the body is the difference between net phosphate absorption through the intestine and phosphate excretion through the kidney. Numerous disorders, both genetic and acquired, may alter phosphate homeostasis. In affected individuals, it is crucial to identify the underlying mechanism(s) to provide adequate treatment; however, phosphate homeostasis assessment remains challenging. Besides the measurement of key hormones involved in the control of phosphate homeostasis (parathyroid hormone, vitamin D and metabolites, fibroblast growth factor 23), assessing the magnitude of phosphate reabsorption by the kidney is a crucial step. It makes it possible to distinguish between a primary disorder of renal phosphate reabsorption, associated with an intrinsic defect or endocrine disturbance, and a nutritional cause of phosphate deficiency. This strategy is described, and the potential consequences for therapeutic decisions are discussed.


Assuntos
Fenômenos Bioquímicos/fisiologia , Fatores de Crescimento de Fibroblastos/farmacologia , Homeostase/efeitos dos fármacos , Fosfatos/metabolismo , Fator de Crescimento de Fibroblastos 23 , Fatores de Crescimento de Fibroblastos/farmacocinética , Homeostase/fisiologia , Humanos
12.
Dev Biol ; 475: 234-244, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33582116

RESUMO

Sustaining life requires efficient uptake of nutrients and conversion to useable forms. Almost everything about this process is dynamic. Nutrient availability fluctuates and changing environmental conditions impose new demands that can tip the metabolic equilibrium from biosynthesis and macromolecule storage to energy expenditure. At the same time, the organism itself changes, particularly during the rapid growth and differentiation in early development and also later in life as the adult ages. Here we review what has been learned from Drosophila melanogaster as an experimental model about the connections between external signals, signaling pathways, tissues and organs that allow animals to balance energy storage with expenditure in the face of change, both intrinsic and extrinsic.


Assuntos
Drosophila melanogaster/embriologia , Metabolismo Energético/fisiologia , Homeostase/fisiologia , Animais , Proteínas de Drosophila/metabolismo , Nutrientes , Transdução de Sinais
13.
Diabetes Metab Res Rev ; 37(3): e3389, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32738094

RESUMO

AIMS: Hypothalamus-pituitary-adrenal (HPA) axis hyperactivity was suggested to be associated with the metabolic syndrome (MS), obesity and diabetes. The aim of this study was to test whether hypercortisolism was associated with altered glucose homeostasis and insulin resistance, hypertension and dyslipidemia in a homogeneous population of obese patients. MATERIALS/METHODS: In retrospective analysis of a set of data about obese patients attending the outpatient service of a single obesity centre between January 2013 and January 2020, 884 patients with BMI >30 kg/m2 were segregated in two subgroups: patients with urinary free cortisol (UFC) higher than normal (UFC+; n = 129) or within the normal range (UFC-; n = 755). RESULTS: The overall prevalence of UFC+ was 14.6% and double test positivity (morning cortisol >1.8 mcg/dL following overnight dexamethasone suppression test, ODST) was detected in 1.0% of patients. Prediabetes (OR 1.74; 95%CI 1.13-2.69; p = 0.012) and diabetes (OR 2.03; 95%CI 1.21-3.42; p = 0.008) were associated with higher risk of UFC+ when analysis was adjusted for confounding variables. Conversely, hypertension and dyslipidemia were not related to UFC+. Within the individuals with normal FPG and HbA1c, those with higher estimated insulin resistance (HOMA2-IR) maintained a higher risk of UFC+ (OR 2.84, 95%CI 1.06-7.63; p = 0.039) and this relationship was weakened only when the body fat percentage was included into the model. CONCLUSIONS: In obese patients, hypercortisolism was more frequent across the entire spectrum of altered glucose homeostasis including the very early stages; this relation could not be detected for the other criteria of the MS, as waist, hypertension and atherogenic dyslipidemia.


Assuntos
Síndrome de Cushing , Glucose , Homeostase , Obesidade , Cirurgia Bariátrica , Síndrome de Cushing/complicações , Glucose/metabolismo , Homeostase/fisiologia , Humanos , Obesidade/fisiopatologia , Obesidade/cirurgia , Estudos Retrospectivos
14.
Sci Rep ; 10(1): 9600, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32541858

RESUMO

Various methodologies to assess cerebral autoregulation (CA) have been developed, including model - based methods (e.g. autoregulation index, ARI), correlation coefficient - based methods (e.g. mean flow index, Mx), and frequency domain - based methods (e.g. transfer function analysis, TF). Our understanding of relationships among CA indices remains limited, partly due to disagreement of different studies by using real physiological signals, which introduce confounding factors. The influence of exogenous noise on CA parameters needs further investigation. Using a set of artificial cerebral blood flow velocities (CBFV) generated from a well-known CA model, this study aims to cross-validate the relationship among CA indices in a more controlled environment. Real arterial blood pressure (ABP) measurements from 34 traumatic brain injury patients were applied to create artificial CBFVs. Each ABP recording was used to create 10 CBFVs corresponding to 10 CA levels (ARI from 0 to 9). Mx, TF phase, gain and coherence in low frequency (LF) and very low frequency (VLF) were calculated. The influence of exogenous noise was investigated by adding three levels of colored noise to the artificial CBFVs. The result showed a significant negative relationship between Mx and ARI (r = -0.95, p < 0.001), and it became almost purely linear when ARI is between 3 to 6. For transfer function parameters, ARI positively related with phase (r = 0.99 at VLF and 0.93 at LF, p < 0.001) and negatively related with gain_VLF(r = -0.98, p < 0.001). Exogenous noise changed the actual values of the CA parameters and increased the standard deviation. Our results show that different methods can lead to poor correlation between some of the autoregulation parameters even under well controlled situations, undisturbed by unknown confounding factors. They also highlighted the importance of exogenous noise, showing that even the same CA value might correspond to different CA levels under different 'noise' conditions.


Assuntos
Cérebro/fisiologia , Homeostase/fisiologia , Modelos Neurológicos , Adulto , Lesões Encefálicas Traumáticas , Circulação Cerebrovascular/fisiologia , Feminino , Humanos , Masculino
16.
Methods Mol Biol ; 2139: 117-131, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32462582

RESUMO

Subcellular proteomics include, in its experimental workflow, steps aimed at purifying organelles. The purity of the subcellular fraction should be assessed before mass spectrometry analysis, in order to confidently conclude the presence of associated specific proteoforms, deepening the knowledge of its biological function. In this chapter, a protocol for isolating endoplasmic reticulum (ER) and purity assessment is reported, and it precedes the proteomic analysis through a gel-free/label-free proteomic approach. Dysfunction of quality-control mechanisms of protein metabolism in ER leads to ER stress. Additionally, ER, which is a calcium-storage organelle, is responsible for signaling and homeostatic function, and calcium homeostasis is required for plant tolerance. With such predominant cell functions, effective protocols to fractionate highly purified ER are needed. Here, isolation methods and purity assessments of ER are described. In addition, a gel-free/label-free proteomic approach of ER is presented.


Assuntos
Retículo Endoplasmático/metabolismo , Proteoma/metabolismo , Proteômica/métodos , Cálcio/metabolismo , Estresse do Retículo Endoplasmático/fisiologia , Homeostase/fisiologia , Espectrometria de Massas/métodos , Organelas/metabolismo , Frações Subcelulares/metabolismo
17.
J Diabetes Res ; 2020: 4950584, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32337294

RESUMO

AIMS: This study is aimed at assessing the association of previously developed indices of glucose homeostasis derived from principal component analysis (PCA) with parameters of insulin action, secretion, and beta cell function during pregnancy. METHODS: In this prospective longitudinal study, an oral glucose tolerance test was performed in sixty-seven pregnant women at two prepartum (12+0 to 22+6 and 24+0 to 28+6) and one postpartum (2 to 11 months) visits. Three principal component scores (PCS) were calculated based on measurements of glucose, insulin, C-peptide, age, and BMI to assess their association with fasting and dynamic indices of insulin action, secretion, and ß-cell function. RESULTS: PCS1 was positively associated with fasting and dynamic parameters of insulin sensitivity (Matsuda index: r = 0.93, p < 0.001), whereas a strong negative association was observed for early, late, and total insulin response. PCS2 was associated with higher mean glucose but negatively related to parameters of insulin secretion. PCS3 was significantly associated with fasting indices of insulin sensitivity. PCS1 to 3 assessed at early pregnancy were also associated with development of GDM, whereby random forest analysis revealed the highest variable importance for PCS1. PCS1 to 3 were significantly related to the oral disposition index explaining 49.0% of its variance. CONCLUSIONS: PCS1 to 3 behaved similarly as compared to previous observations in nonpregnant women and were furthermore associated with the development of GDM. These findings support our hypothesis that PCS1 to 3 could be used as novel indices of glucose disposal during pregnancy.


Assuntos
Glicemia/metabolismo , Diabetes Gestacional/diagnóstico , Homeostase/fisiologia , Secreção de Insulina/fisiologia , Adulto , Peptídeo C/sangue , Diabetes Gestacional/sangue , Feminino , Teste de Tolerância a Glucose , Humanos , Insulina/sangue , Resistência à Insulina/fisiologia , Gravidez , Análise de Componente Principal , Estudos Prospectivos , Adulto Jovem
18.
Chemosphere ; 251: 126393, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32155496

RESUMO

Fumonisin B1 (FB1) is a mycotoxin frequently found in agricultural commodities, and poses a considerable risk for human and animal health. The aim of this study was to investigate the toxic effect of FB1 in mice intestine. Male Kunming mice (n = 40) were treated with FB1 diet for 42 days. Histopathological and biochemical analyses, including ion concentrations, transcription of ATPase subunits and mRNA expression of cytochrome P450s (CYP450s) analyses were performed on duodenum, cecum and colon of mice. The results revealed that FB1 caused histological alterations, including partial shedding of villous epithelial cells and inflammatory cell infiltration. Furthermore, a significant change in Na+, K+ and Ca2+ in serum, and the mRNA expression of ATPase subunits and CYP450s in intestinal tracts were observed in FB1-exposed mice. Our results suggested that FB1 exposure induce histopathological injury via disrupting CYP isoforms transcription and triggering ion homeostasis imbalance in mice intestinal tracts.


Assuntos
Carcinógenos Ambientais/toxicidade , Sistema Enzimático do Citocromo P-450/metabolismo , Fumonisinas/toxicidade , Homeostase/fisiologia , Animais , Células Epiteliais , Humanos , Fígado/efeitos dos fármacos , Masculino , Camundongos , Micotoxinas/toxicidade
19.
Turk J Med Sci ; 50(2): 405-410, 2020 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-32041386

RESUMO

Background/aim: We aimed to revealthe incidence and predictive role of insulin resistance and distorted oral glucose tolerance test in nondiabetic patients withBell's Palsy (BP). Materials and methods: Eighty-sixpatients with BP and 28 control subjects; all with normal blood glucose levels and no history of diabetes, were enrolled in the study. We investigated insulin resistance (IR) in all subjects, in terms of HOMA-IR greater than 2.7. Sixty-two of the patients also underwent an oral glucose tolerance test (OGTT). Results: The mean HOMA-IR value was significantly increased in patients, compared to the control group (3.2 vs 1.6; P < 0.01). IR was detected more in BP patients than in controls (P < 0.05). The patients with higher HOMA-IR values had more severe facial dysfunction at the initial presentation and complete recovery time took longer than the patients with normal HOMA-IR value (75 days vs 42 days; P < 0.05). Following a 2h-OGTT, impaired glucose tolerance and newly diagnosed DM were found in 60% of the patients. Recovery time was significantly longer in prediabetics and newly diagnosed diabetic patients than in patients with normal glycemia (68 days, 52 days, and 32 days, respectively; P < 0.01). Conclusion: There is a strong linkage between HOMA-IR value and BP prognosis so HOMA-IR value may have a significant role of predicting BP prognosis at presentation.


Assuntos
Paralisia de Bell , Glicemia/análise , Resistência à Insulina/fisiologia , Estado Pré-Diabético , Paralisia de Bell/complicações , Paralisia de Bell/diagnóstico , Paralisia de Bell/epidemiologia , Estudos de Casos e Controles , Teste de Tolerância a Glucose , Homeostase/fisiologia , Humanos , Estado Pré-Diabético/complicações , Estado Pré-Diabético/diagnóstico , Estado Pré-Diabético/epidemiologia , Prognóstico
20.
Curr Top Med Chem ; 20(7): 524-539, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32003689

RESUMO

The gut and mitochondria have emerged as two important hubs at the cutting edge of research across a diverse array of medical conditions, including most psychiatric conditions. This article highlights the interaction of the gut and mitochondria over the course of development, with an emphasis on the consequences for transdiagnostic processes across psychiatry, but with relevance to wider medical conditions. As well as raised levels of circulating lipopolysaccharide (LPS) arising from increased gut permeability, the loss of the short-chain fatty acid, butyrate, is an important mediator of how gut dysbiosis modulates mitochondrial function. Reactive cells, central glia and systemic immune cells are also modulated by the gut, in part via impacts on mitochondrial function in these cells. Gut-driven alterations in the activity of reactive cells over the course of development are proposed to be an important determinant of the transdiagnostic influence of glia and the immune system. Stress, including prenatal stress, also acts via the gut. The suppression of butyrate, coupled to raised LPS, drives oxidative and nitrosative stress signalling that culminates in the activation of acidic sphingomyelinase-induced ceramide. Raised ceramide levels negatively regulate mitochondrial function, both directly and via its negative impact on daytime, arousal-promoting orexin and night-time sleep-promoting pineal gland-derived melatonin. Both orexin and melatonin positively regulate mitochondria oxidative phosphorylation. Consequently, gut-mediated increases in ceramide have impacts on the circadian rhythm and the circadian regulation of mitochondrial function. Butyrate, orexin and melatonin can positively regulate mitochondria via the disinhibition of the pyruvate dehydrogenase complex, leading to increased conversion of pyruvate to acetyl- CoA. Acetyl-CoA is a necessary co-substrate for the initiation of the melatonergic pathway in mitochondria and therefore the beneficial effects of mitochondria melatonin synthesis on mitochondrial function. This has a number of treatment implications across psychiatric and wider medical conditions, including the utilization of sodium butyrate and melatonin. Overall, gut dysbiosis and increased gut permeability have significant impacts on central and systemic homeostasis via the regulation of mitochondrial function, especially in central glia and systemic immune cells.


Assuntos
Disbiose/classificação , Disbiose/tratamento farmacológico , Microbioma Gastrointestinal/fisiologia , Homeostase/fisiologia , Lipopolissacarídeos/metabolismo , Mitocôndrias/metabolismo , Ácido Butírico/metabolismo , Linhagem Celular , Humanos , Sistema Imunitário/citologia , Inflamação/metabolismo , Melatonina/metabolismo , Neuroglia/citologia , Estresse Nitrosativo , Orexinas/metabolismo , Oxirredução , Estresse Oxidativo , Permeabilidade , Fosforilação , Psiquiatria/métodos , Transdução de Sinais
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA