Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 198
Filtrar
1.
J Environ Manage ; 345: 118699, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37536137

RESUMO

An amount of works has reported the effect of wastewater matrix composition on pollutants removal by different AOPs. The biggest challenge is that each wastewater source has a challenging composition (organic and inorganic compounds, pollutants, etc.) and not only the concentration of all these species but also the interaction between them may affect the effectiveness of the studied process. This work has been carried out to evaluate the photo-degradation kinetics of six different pesticides (flutriafol, imidacloprid, myclobutanil, pirimicarb, thiamethoxam and triadimenol) by solar photo-Fenton (SPF) process at acidic pH. First, oxidant concentration (H2O2) was optimized with an actual WWTP effluent. Then, the process was validated with two different secondary and tertiary WWTP effluents, in which main intermediate transformation by-products were identified. Finally, the effect of the inorganic water matrix components (bicarbonate, chloride, sulphate, nitrate and phosphate) was evaluated by a multivariate analysis. Once H2O2 has been optimized at 30 mg L-1, the photo-degradation efficiency of pesticides in real wastewater samples was compared. DOC content of both secondary and tertiary WWTP effluents was dropped by 67%. The identification of the main intermediate transformation by-products (such as 1H-1,2,4-triazole, desmethyl-formamido pirimicarb, thiamethoxam urea, chloronicotinic acid and imidacloprid urea) was reviewed. Following, the multivariate analysis on pesticides photo-degradation, generally, predicted four significant effects in common for the studied pesticides: a positive effect (interaction bicarbonate/nitrate) and three negative ones (chloride, phosphate and the interaction chloride/sulphate); among others. In addition, optimum values of inorganic ion concentrations, to obtain an optimum desirability on studied pesticides removal by SPF at acidic pH, were also evaluated.


Assuntos
Poluentes Ambientais , Praguicidas , Poluentes Químicos da Água , Águas Residuárias , Praguicidas/análise , Peróxido de Hidrogênio/química , Ferro/química , Tiametoxam/análise , Bicarbonatos/análise , Cloretos/análise , Nitratos/análise , Poluentes Ambientais/análise , Poluentes Químicos da Água/química , Oxirredução
2.
FEBS J ; 288(2): 699-712, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32383536

RESUMO

Neuronal intracellular chloride concentration ([Cl- ]i ) is a crucial determinant of transmission mediated by the γ-aminobutyric acid type A receptor (GABAA R), which subserves synaptic and extrasynaptic inhibition as well as excitation. The Cl- ion is the main carrier of charge through the GABAA R; however, bicarbonate ions ( HCO3- ) flowing in the opposite direction can also contribute to the net current. The direction of Cl- and HCO3- fluxes is determined by the underlying electrochemical gradient, which is controlled by Cl- transporters and channels. Accumulating evidence suggests that active mechanisms of chloride transport across the GABAA R pore can underlie the regulation of [Cl- ]i . Measurement of Cl- / HCO3- -ATPase activity and Cl- transport in HEK 293FT cells expressing homomeric or heteromeric GABAA R ensembles (α2, ß3, or γ2) with fluorescent dye for chloride demonstrated that receptor subtypes containing the ß3 subunit show enzymatic activity and participate in GABA-mediated or ATP-dependent Cl- transport. GABA-mediated flow of Cl- ions into and out of the cells occurred for a short time period but then rapidly declined. However, Cl- ion flux was stabilized for a long time period in the presence of HCO3- ions. The reconstituted ß3 subunit isoform, purified as a fusion protein, confirmed that ß3 is critical for ATPase; however, only the triplet variant showed the full receptor function. The high sensitivity of the enzyme to γ-phosphate inhibitors led us to postulate that the ß3 subunit is catalytic. Our discovery of a GABAA R type that requires ATP consumption for chloride movement provides new insight into the molecular mechanisms of inhibitory signaling.


Assuntos
Adenosina Trifosfatases/metabolismo , Bicarbonatos/metabolismo , Cloretos/metabolismo , Receptores de GABA-A/metabolismo , Adenosina Trifosfatases/análise , Animais , Bicarbonatos/análise , Células Cultivadas , Cloretos/análise , Células HEK293 , Humanos , Microscopia de Fluorescência , Ratos , Receptores de GABA-A/genética
3.
PLoS One ; 15(8): e0237596, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785283

RESUMO

Blood was collected from wild captured green and Kemp's ridley turtles off the west coast of Florida, USA. Blood gases and biochemical values were analyzed using a point of care (POC) device in the field. Analytes include pH, partial pressure of carbon dioxide (pCO2), partial pressure of oxygen (pO2), total carbon dioxide (TCO2), bicarbonate (HCO3), base excess (BE), oxygen saturation (sO2), lactate, sodium (Na), potassium (K), chloride (Cl), total carbon dioxide (TCO2), anion gap, ionized calcium, glucose, blood urea nitrogen (BUN), creatinine (Crea), hematocrit (Hct), and hemoglobin (Hb). These are novel data for wild healthy Kemp's ridley turtles, and results for green turtles were generally consistent with past studies of green turtles with exceptions primarily in blood gas values. Ninety percent of the green turtles had fibropapillomatosis (FP), but none of the blood analytes were correlated with disease severity. Only BUN was correlated with weight of green turtles, and there was no correlation between blood parameters and weight of Kemp's ridley turtles. This study provides data that are useful in understanding the physiologic status of sea turtles specific to this region, allowing for comparisons to other populations, life stages, and disease states.


Assuntos
Gasometria/veterinária , Nitrogênio da Ureia Sanguínea , Oxigênio/metabolismo , Tartarugas/metabolismo , Veias/metabolismo , Animais , Bicarbonatos/análise , Dióxido de Carbono/análise , Potássio/análise , Sódio/análise , Tartarugas/classificação
4.
J. bras. nefrol ; 42(2): 191-200, Apr.-June 2020. tab, graf
Artigo em Inglês, Português | LILACS | ID: biblio-1134816

RESUMO

ABSTRACT Introduction: National data on chronic dialysis treatment are essential for the development of health policies that aim to improve patient treatment. Objective: To present data from the Brazilian Society of Nephrology on patients with chronic dialysis for kidney disease in July 2018, making a comparative analysis of the past 10 years. Methods: Data collection from dialysis units, with filling in an online questionnaire for 2018. Data from 2009, 2013 and 2018 were compared. Results: 288 (36.6%) centers answered the questionnaire. In July 2018, the estimated total number of patients on dialysis was 133,464. Estimates of the prevalence and incidence rates of patients undergoing dialysis treatment per million of the population (pmp) were 640 and 204, respectively, with average annual increases of 23.5 pmp and 6 pmp for prevalence and incidence, respectively. The annual gross mortality rate was 19.5%. Of the prevalent patients, 92.3% were on hemodialysis and 7.7% on peritoneal dialysis, with 29,545 (22.1%) on the waiting list for transplantation. Median bicarbonate concentration in the hemodialysis bath was 32 mEq/L. Venous catheters were used as access in 23.6% of the hemodialysis patients. The prevalence rate of positive serology for hepatitis C showed a progressive reduction (3.2%). Conclusion: The absolute number of patients and rates of incidence and prevalence in dialysis in the country increased substantially in the period, although there are considerable differences in rates by state. There has been a persistent increase in the use of venous catheters as an access for dialysis; and reduction in the number of patients with positive serology for hepatitis C.


RESUMO Introdução: Dados nacionais sobre o tratamento dialítico crônico são essenciais para a elaboração de políticas de saúde que almejem melhora no tratamento dos pacientes. Objetivo: Apresentar dados do inquérito da Sociedade Brasileira de Nefrologia sobre pacientes com doença renal crônica dialítica em julho de 2018, fazendo análise comparativa dos últimos 10 anos. Métodos: Coleta de dados a partir das unidades de diálise, com preenchimento de questionário on-line referentes a 2018. Foram comparados dados de 2009, 2013 e 2018. Resultados: 288 (36,6%) centros responderam ao questionário. Em julho de 2018, o número total estimado de pacientes em diálise foi de 133.464. Estimativas das taxas de prevalência e incidência de pacientes em tratamento dialítico por milhão da população (pmp) foram de 640 e 204, respectivamente, com médias de aumento anuais de 23,5 pmp e 6 pmp para prevalência e incidência, respectivamente. Taxa anual de mortalidade bruta foi de 19,5%. Dos pacientes prevalentes, 92,3% estavam em hemodiálise e 7,7%, em diálise peritoneal, com 29.545 (22,1%) em fila de espera para transplante. Concentração mediana de bicarbonato no banho de hemodiálise foi de 32 mEq/L. Cateter venoso era usado como acesso em 23,6% dos pacientes em hemodiálise. Taxa de prevalência de sorologia positiva para hepatite C apresentou redução progressiva (3,2%). Conclusão: Número absoluto de pacientes e taxas de incidência e prevalência em diálise no país aumentaram substancialmente no período, embora haja diferenças consideráveis nas taxas por estado. Tem havido persistente aumento no uso de cateter venoso como acesso para diálise; e redução de pacientes com sorologia positiva para hepatite C.


Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Idoso , História do Século XXI , Transplante de Rim/estatística & dados numéricos , Diálise Peritoneal/estatística & dados numéricos , Censos/história , Falência Renal Crônica/terapia , Fatores de Tempo , Bicarbonatos/análise , Brasil/epidemiologia , Incidência , Inquéritos e Questionários , Listas de Espera , Hepatite C/epidemiologia , Cateteres Venosos Centrais/provisão & distribuição , Cateteres Venosos Centrais/estatística & dados numéricos , Nefrologia/organização & administração
5.
Sensors (Basel) ; 20(6)2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32168979

RESUMO

Bicarbonate plays a central role in human physiology from cellular respiration to pH homeostasis. However, so far, the measurement of bicarbonate concentration changes in living cells has only been possible by measuring intracellular pH changes. In this article, we report the development of a genetically encoded pH-independent fluorescence-based single-use sensory cellular test system for monitoring intracellular bicarbonate concentration changes in living cells. We describe the usefulness of the developed biosensor in characterizing the bicarbonate transport activities of anionophores-small molecules capable of facilitating the membrane permeation of this anion. We also demonstrate the ability of the bicarbonate sensory cellular test system to measure intracellular bicarbonate concentration changes in response to activation and specific inhibition of wild-type human CFTR protein when co-expressed with the bicarbonate sensing and reporting units in living cells. A valuable benefit of the bicarbonate sensory cellular test system could be the screening of novel anionophore library compounds for bicarbonate transport activity with efficiencies close to the natural anion channel CFTR, which is not functional in the respiratory epithelia of cystic fibrosis patients.


Assuntos
Bicarbonatos/análise , Técnicas Biossensoriais , Adenilil Ciclases/metabolismo , Animais , Bicarbonatos/metabolismo , Transporte Biológico/fisiologia , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Células CHO , Cricetinae , Cricetulus , Regulador de Condutância Transmembrana em Fibrose Cística/antagonistas & inibidores , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Humanos , Espaço Intracelular/química , Espaço Intracelular/metabolismo
6.
Int J Mol Sci ; 20(21)2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31717704

RESUMO

Adenosine regulates exocrine and endocrine secretions in the pancreas. Adenosine is considered to play a role in acini-to-duct signaling in the exocrine pancreas. To identify the molecular basis of functional adenosine receptors in the exocrine pancreas, immunohistochemical analysis was performed in the rat, mouse, and guinea pig pancreas, and the secretory rate and concentration of HCO3- in pancreatic juice from the rat pancreas were measured. The A2A adenosine receptor colocalized with ezrin, an A-kinase anchoring protein, in the luminal membrane of duct cells in the mouse and guinea pig pancreas. However, a strong signal ascribed to A2B adenosine receptors was detected in insulin-positive ß cells in islets of Langerhans. The A2A adenosine receptor agonist 4-[2-[[6-Amino-9-(N-ethyl-ß-D-ribofuranuronamidosyl)-9H-purin-2-yl]amino]ethyl]benzenepropanoic acid (CGS 21680) stimulated HCO3--rich fluid secretion from the rat pancreas. These results indicate that A2A adenosine receptors may be, at least in part, involved in the exocrine secretion of pancreatic duct cells via acini-to-duct signaling. The adenosine receptors may be a potential therapeutic target for cancer as well as exocrine dysfunctions of the pancreas.


Assuntos
Pâncreas/metabolismo , Receptores Purinérgicos P1/metabolismo , Roedores/metabolismo , Animais , Bicarbonatos/análise , Proteínas do Citoesqueleto/metabolismo , Feminino , Cobaias , Ilhotas Pancreáticas/metabolismo , Masculino , Camundongos , Pâncreas/química , Ductos Pancreáticos/metabolismo , Ratos
7.
Magn Reson Med ; 81(4): 2702-2709, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30375043

RESUMO

PURPOSE: To develop and translate a metabolite-specific imaging sequence using a symmetric echo planar readout for clinical hyperpolarized (HP) Carbon-13 (13 C) applications. METHODS: Initial data were acquired from patients with prostate cancer (N = 3) and high-grade brain tumors (N = 3) on a 3T scanner. Samples of [1-13 C]pyruvate were polarized for at least 2 h using a 5T SPINlab system operating at 0.8 K. Following injection of the HP substrate, pyruvate, lactate, and bicarbonate (for brain studies) were sequentially excited with a singleband spectral-spatial RF pulse and signal was rapidly encoded with a single-shot echo planar readout on a slice-by-slice basis. Data were acquired dynamically with a temporal resolution of 2 s for prostate studies and 3 s for brain studies. RESULTS: High pyruvate signal was seen throughout the prostate and brain, with conversion to lactate being shown across studies, whereas bicarbonate production was also detected in the brain. No Nyquist ghost artifacts or obvious geometric distortion from the echo planar readout were observed. The average error in center frequency was 1.2 ± 17.0 and 4.5 ± 1.4 Hz for prostate and brain studies, respectively, below the threshold for spatial shift because of bulk off-resonance. CONCLUSION: This study demonstrated the feasibility of symmetric EPI to acquire HP 13 C metabolite maps in a clinical setting. As an advance over prior single-slice dynamic or single time point volumetric spectroscopic imaging approaches, this metabolite-specific EPI acquisition provided robust whole-organ coverage for brain and prostate studies while retaining high SNR, spatial resolution, and dynamic temporal resolution.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Isótopos de Carbono , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Imagem Ecoplanar , Neoplasias da Próstata/diagnóstico por imagem , Artefatos , Bicarbonatos/análise , Encéfalo/diagnóstico por imagem , Calibragem , Humanos , Aumento da Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Ácido Láctico/análise , Masculino , Imagem Molecular , Imagens de Fantasmas , Próstata/diagnóstico por imagem , Ácido Pirúvico/análise , Razão Sinal-Ruído
8.
Int Urol Nephrol ; 50(6): 1151-1161, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29728994

RESUMO

BACKGROUND: Long-term exposure of conventional peritoneal dialysis (PD) fluid is associated with structural membrane alterations and technique failure. Previously, it has been shown that infiltrating IL-17-secreting CD4+T cells and pro-fibrotic M2 macrophages play a critical role in the PD-induced pathogenesis. Although more biocompatible PD solutions are recognized to better preserve the peritoneal membrane integrity, the impact of these fluids on the composition of the peritoneal cell infiltrate is unknown. MATERIALS AND METHODS: In a uremic PD mouse model, we compared the effects of daily instillation of standard lactate (LS) or bicarbonate/lactate-buffered solutions (BLS) and respective controls on peritoneal fibrosis, vascularisation, and inflammation. RESULTS: Daily exposure of LS fluid during a period of 8 weeks resulted in a peritoneal increase of αSMA and collagen accompanied with new vessel formation compared to the BLS group. Effluent from LS-treated mouse showed a higher percentage of CD4+ IL-17+ cell population while BLS exposure resulted in an increased macrophage population. Significantly enhanced inflammatory cytokines such as TGFß1, TNFα, INFγ, and MIP-1ß were detected in the effluent of BLS-exposed mice when compared to other groups. Further, immunohistochemistry of macrophage subset infiltrates in the BLS group confirmed a higher ratio of pro-inflammatory M1 macrophages over the pro-fibrotic M2 subset compared to LS. CONCLUSION: Development of the peritoneal fibrosis and angiogenesis was prevented in the BLS-exposed mice, which may underlie its improved biocompatibility. Peritoneal recruitment of M1 macrophages and lower number of CD4+ IL-17+ cells might explain the peritoneal integrity preservation observed in BLS-exposed mouse.


Assuntos
Bicarbonatos/análise , Soluções para Diálise/química , Ácido Láctico/análise , Diálise Peritoneal , Peritônio/metabolismo , Peritônio/patologia , Actinas/metabolismo , Animais , Bicarbonatos/administração & dosagem , Soluções Tampão , Contagem de Linfócito CD4 , Linfócitos T CD4-Positivos/metabolismo , Quimiocina CCL4/metabolismo , Colágeno/metabolismo , Modelos Animais de Doenças , Feminino , Interferon gama/metabolismo , Interleucina-17/análise , Ácido Láctico/administração & dosagem , Macrófagos , Macrófagos Peritoneais , Camundongos , Fator de Crescimento Transformador beta/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Uremia/terapia
9.
Artigo em Inglês | MEDLINE | ID: mdl-28974043

RESUMO

The purpose of this study was to identify the concentration of multi-elements (MEs) in source water (surface and drinking water) and assess their quality for sustainability. A total of 161 water samples including 88 tap drinking waters (DW) and 73 surface waters (SW) were collected from five cities in Xi'an, Yan'an, Xining, Lanzhou, and Urumqi in northwestern China. Eighteen parameters including pH, electrical conductivity (EC), total organic carbon (TOC) total nitrogen (TN), chemical compositions of anions (F-, Cl-, NO3-,HCO3-, SO42-), cations (NH4⁺, K⁺, Na⁺, Ca2+,Mg2+), and metals (lead (Pb), chromium (Cr), cadmium (Cd), copper (Cu)) were analyzed in the first time at the five cities . The results showed that pH values and concentrations of Cl-, SO42-, Na⁺, K⁺, Ca2+, Mg2+ and Cd, Cr, Cu in DW were within the permissible limits of the Chinese Drinking Water Quality Criteria, whereas the concentrations of other ions (F-, NO3-, NH4⁺ and Pb) exceeded their permissible values. In terms of the SW, the concentrations of F-, Cl-, NO3-, SO42- were over the third range threshold i.e., water suitable for fishing and swimming of the Surface Water Quality Standards in China. The spatial distributions of most MEs in source water are similar, and there was no clear variation for all ions and metals. The metals in DW may be caused by water pipes, faucets and their fittings. The noncarcinogenic risk of metals in DW for local children are in decreasing order Cr > Cd > Pb > Cu. The carcinogenic risk from Cr exposure was at the acceptable level according to threshold of USEPA. Although the comprehensive index of potential ecological assessment of Cr, Cd, Pb and Cu in SW ranked at low risk level and was in the order of Huang River in Xining > Peaceful Canal in Urumqi > Yan River in Yan'an > Yellow River in Lanzhou, their adverse effects to ecology and human health at a low concentration in local semi-arid and arid areas should not be ignored in the long run.


Assuntos
Poluentes Químicos da Água/análise , Compostos de Amônio/análise , Bicarbonatos/análise , Carbono/análise , Criança , China , Cloretos/análise , Cidades , Clima Desértico , Água Potável/análise , Monitoramento Ambiental , Fluoretos/análise , Humanos , Metais/análise , Nitratos/análise , Nitrogênio/análise , Medição de Risco , Rios/química , Sulfatos/análise
10.
NMR Biomed ; 30(9)2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28653507

RESUMO

In vivo pH mapping in tissue using hyperpolarized hydrogencarbonate-13 C has been proposed as a method to study tumor growth and treatment and other pathological conditions related to pH changes. The finite spin-lattice relaxation times (T1 ) of hyperpolarized media are a significant limiting factor for in vivo imaging. Relaxation times can be measured at standard magnetic fields (1.5 T, 3.0 T etc.), but no such data are available at low fields, where T1 values can be significantly shorter. This information is required to determine the potential loss of polarization as the agent is dispensed and transported from the polarizer to the MRI scanner. The purpose of this study is to measure T1 dispersion from low to clinical magnetic fields (0.4 mT to 3.0 T) of different hyperpolarized hydrogencarbonate formulations previously proposed in the literature for in vivo pH measurements. 13 C-enriched cesium and sodium hydrogencarbonate preparations were hyperpolarized using dynamic nuclear polarization, and the T1 values of different samples were measured at different magnetic field strengths using a fast field-cycling relaxometer and a 3.0 T clinical MRI system. The effects of deuterium oxide as a dissolution medium for sodium hydrogencarbonate were also analyzed. This study finds that the cesium formulation has slightly shorter T1 values compared with the sodium preparation. However, the higher solubility of cesium hydrogencarbonate-13 C means it can be polarized at greater concentration, using less trityl radical than sodium hydrogencarbonate-13 C. This study also establishes that the preparation and handling of sodium hydrogencarbonate formulations in relation to cesium hydrogencarbonate is more difficult, due to the higher viscosity and lower achievable concentrations, and that deuterium oxide significantly increases the T1 of sodium hydrogencarbonate solutions. Finally, this work also investigates the influence of pH on the spin-lattice relaxation of cesium hydrogencarbonate-13 C measured over a pH range of 7 to 9 at 0.47 T.


Assuntos
Bicarbonatos/análise , Isótopos de Carbono/análise , Césio/análise , Espectroscopia de Ressonância Magnética/métodos , Sódio/análise , Concentração de Íons de Hidrogênio , Marcadores de Spin
11.
Artigo em Inglês | MEDLINE | ID: mdl-28629192

RESUMO

In order to describe iron stability in plastic pipes and to ensure the drinking water security, the influence factors and rules for iron adsorption and release were studied, dependent on the Unplasticized poly (vinyl chloride) (PVC-U) drinking pipes employed in this research. In this paper, sulfate, chloride, and bicarbonate, as well as synthesized models, were chosen to investigate the iron stability on the inner wall of PVC-U drinking pipes. The existence of the three kinds of anions could significantly affect the process of iron adsorption, and a positive association was found between the level of anion concentration and the adsorption rate. However, the scaling formed on the inner surface of the pipes would be released into the water under certain conditions. The Larson Index (LI), used for a synthetic consideration of anion effects on iron stability, was selected to investigate the iron release under multi-factor conditions. Moreover, a well fitted linear model was established to gain a better understanding of iron release under multi-factor conditions. The simulation results demonstrated that the linear model was better fitted than the LI model for the prediction of iron release.


Assuntos
Ferro/química , Poluentes Químicos da Água/análise , Abastecimento de Água , Adsorção , Bicarbonatos/análise , Cloretos/análise , Cloreto de Polivinila/análise , Sulfatos/análise
12.
Perit Dial Int ; 36(5): 569-72, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27659931

RESUMO

Interference of conventional peritoneal dialysis fluids (cPDFs) with peritoneal membrane cell functions may be attributed to the dialysis fluid's low pH, high glucose concentration, and/or the presence of glucose degradation products (GDPs), the last of which leads to higher levels of advanced glycation end-products (AGEs). It has been suggested that the peritoneal membrane might be better preserved by using biocompatible solutions, including cancer antigetn 125 (CA125). This prospective, open-label, multicentre, randomized, controlled, cross-over phase IV study compared the in vivo biocompatibility of a neutral-pH, low-GDP peritoneal dialysis (PD) solution (balance) with a cPDF in automated PD (APD) patients. Our study revealed a significantly increased appearance rate and concentration of CA125 in the peritoneal effluent of APD patients treated with the neutral-pH, low-GDP solution balance versus a conventional PD solution.


Assuntos
Materiais Biocompatíveis/química , Soluções para Diálise/química , Diálise Peritoneal/métodos , Peritônio/efeitos dos fármacos , Equilíbrio Hidroeletrolítico/fisiologia , Adulto , Automação , Bicarbonatos/análise , Antígeno Ca-125/metabolismo , Intervalos de Confiança , Creatinina/urina , Estudos Cross-Over , Feminino , Glucose/análise , Humanos , Concentração de Íons de Hidrogênio , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Diálise Peritoneal/efeitos adversos , Peritônio/metabolismo , Estudos Prospectivos , Ureia/urina
13.
Bioresour Technol ; 211: 65-71, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26998799

RESUMO

Excessive acidification occurs frequently in food waste (FW) anaerobic digestion (AD) due to the high carbon-to-nitrogen ratio of FW. In this study, zero-valent iron (ZVI) was applied to prevent the excessive acidification. All of the control groups, without ZVI addition (pH∼5.3), produced little methane (CH4) and had high volatile fatty acids/bicarbonate alkalinity (VFA/ALK). By contrast, at OLR of 42.32gVS/Lreactor, the pH of effluent from the reactors with 0.4g/gVSFWadded of ZVI increased to 7.8-8.2, VFA/ALK decreased to <0.1, and the final CH4 yield was ∼380mL/gVSFWadded, suggesting inhibition of excessive acidification. After adding powdered or scrap metal ZVI to the acidogenic reactors, the fractional content of butyric acid changed from 30-40% to 0%, while, that of acetic acid increased. These results indicate that adding ZVI to FW digestion at high OLRs could eliminate excessive acidification by promoting butyric acid conversion and enhancing methanogen activity.


Assuntos
Alimentos , Ferro/química , Gerenciamento de Resíduos/métodos , Ácido Acético/análise , Ácido Acético/química , Ácido Acético/metabolismo , Anaerobiose , Bicarbonatos/análise , Bicarbonatos/química , Bicarbonatos/metabolismo , Reatores Biológicos , Ácido Butírico/análise , Ácido Butírico/química , Ácido Butírico/metabolismo , Carbono/análise , Carbono/metabolismo , Ácidos Graxos Voláteis/análise , Ácidos Graxos Voláteis/química , Ácidos Graxos Voláteis/metabolismo , Concentração de Íons de Hidrogênio , Metano/análise , Metano/química , Metano/metabolismo
14.
Theriogenology ; 85(2): 238-46, 2016 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-26483308

RESUMO

Secretions of chloride (Cl(-))- and bicarbonate (HCO3(-))-rich fluid by the seminal vesicles could involve cystic fibrosis transmembrane regulator (CFTR), which activity can be stimulated by cAMP generated from the reaction involving adenylate cyclase (AC). In this study, we investigated levels of CFTR, AC, and cAMP in the seminal vesicles under testosterone influence. Orchidectomized adult male rats received 7-day treatment with 125 or 250 µg/kg/day of testosterone with or without flutamide or finasteride. At the end of the treatment, animals were sacrificed and seminal vesicles were harvested for analyses of CFTR and AC protein expression level by Western blotting. Distribution of CFTR and AC in seminal vesicles was observed by immunohistochemistry. Levels of cAMP and dihydrotestosterone in seminal vesicle homogenates were measured by ELISA. Cystic fibrosis transmembrane regulator, AC, and cAMP levels increased with increasing doses of testosterone (P < 0.05 compared to nontreated orchidectomized rats). Cystic fibrosis transmembrane regulator and AC were expressed at the apical membrane of the epithelium lining the seminal vesicle lumen with higher expression levels observed in testosterone-treated rats than in non-treated orchidectomized rats (P < 0.05). The inhibitory effects of flutamide or finasteride on these parameters were greater in 250 µg/kg/day testosterone-treated rats than their effects in 125 µg/kg/day testosterone-treated rats. Higher dihydrotestosterone levels were observed in seminal vesicle homogenates after treatment with 250 µg/kg/day than with 125 µg/kg/day of testosterone (P < 0.05). Increased levels of CFTR, AC, and cAMP in seminal vesicles might contribute toward an increase in Cl(-) and HCO3(-) concentrations in the seminal fluid as reported under testosterone influence.


Assuntos
Adenilato Quinase/análise , AMP Cíclico/análise , Regulador de Condutância Transmembrana em Fibrose Cística/análise , Orquiectomia , Glândulas Seminais/efeitos dos fármacos , Testosterona/farmacologia , Inibidores de 5-alfa Redutase , Antagonistas de Androgênios , Animais , Bicarbonatos/análise , Western Blotting , Cloretos/análise , Di-Hidrotestosterona/análise , Finasterida/farmacologia , Flutamida/farmacocinética , Masculino , Ratos , Ratos Sprague-Dawley , Sêmen/química , Glândulas Seminais/química , Testosterona/fisiologia
15.
Eur J Oral Sci ; 123(1): 9-16, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25557910

RESUMO

Formation of crystals in the enamel space releases protons that need to be buffered to sustain mineral accretion. We hypothesized that apical cystic fibrosis transmembrane conductance regulator (CFTR) in maturation ameloblasts transduces chloride into forming enamel as a critical step to secrete bicarbonates. We tested this by determining the calcium, chloride, and fluoride levels in developing enamel of Cftr-null mice by quantitative electron probe microanalysis. Maturation-stage enamel from Cftr-null mice contained less chloride and calcium than did wild-type enamel, was more acidic when stained with pH dyes ex vivo, and formed no fluorescent modulation bands after in vivo injection of the mice with calcein. To acidify the enamel further we exposed Cftr-null mice to fluoride in drinking water to stimulate proton release during formation of hypermineralized lines. In Cftr-deficient mice, fluoride further lowered enamel calcium without further reducing chloride levels. The data support the view that apical CFTR in maturation ameloblasts tranduces chloride into developing enamel as part of the machinery to buffer protons released during mineral accretion.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/fisiologia , Fibrose Cística/metabolismo , Esmalte Dentário/química , Calcificação de Dente/fisiologia , Ameloblastos/metabolismo , Amelogênese/fisiologia , Animais , Bicarbonatos/análise , Soluções Tampão , Cálcio/análise , Cariostáticos/farmacologia , Cloretos/análise , Cloretos/metabolismo , Esmalte Dentário/efeitos dos fármacos , Microanálise por Sonda Eletrônica , Fluoresceínas , Corantes Fluorescentes , Fluoretos/análise , Fluoretos/sangue , Fluoretos/farmacologia , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Camundongos , Camundongos Endogâmicos CFTR , Microtomografia por Raio-X/métodos
16.
Arq. bras. med. vet. zootec ; 66(4): 1225-1233, 08/2014. tab
Artigo em Português | LILACS | ID: lil-722584

RESUMO

Foram analisados os níveis de pCO2, pO2, pH e HCO3 - de embriões e pintos de corte provenientes de matrizes novas e velhas, nos momentos anteriores à bicagem interna e externa da casca e ao nascimento, submetidos a diferentes períodos de transferência para as condições ambientais dos nascedouros. Os tratamentos foram definidos pela idade da matriz (33 e 63 semanas) e pela transferência para o nascedouro (aos 15, 17 e 19 dias). O delineamento experimental foi em parcelas subdivididas, sendo a parcela os três momentos de transferência e a subparcela as duas idades das matrizes. Foram utilizadas seis repetições para cada tratamento, e o embrião ou o pinto foi considerado uma repetição. Os dados normais e homogêneos foram submetidos às análises de variância, e as médias comparadas pelos testes F, de Tukey e SNK. Embriões cujos ovos foram transferidos aos 15 dias para o nascedouro apresentaram melhor equilíbrio ácido-básico durante as fases pré-natal e perinatal. Durante o último terço da incubação, independentemente das diferentes condições ambientais às quais os embriões são submetidos e da idade da matriz, há capacidade de resposta fisiológica que permite uma estabilidade no equilíbrio ácido-básico dos pintos após a eclosão...


We analyzed the levels of pCO2, pO2, pH and HCO3 - in embryos and chicks from young and older breeders, in the moments before internal pipping, external pipping and at hatch and submitted to different periods in the environmental conditions of hatchers. The treatments were defined by breeder age (33 and 63 weeks) and transfer to the hatcher (at 15, 17 and 19 days). The experimental design was split plots with three periods in the hatcher and the plots were the two breeder ages. We used six replicates per treatment and the embryo or chick was considered a repetition. The normal data forms were submitted to analysis of variance and means were compared by F, Tukey and SNK tests. Embryos transferred at 15 days to the hatcher had better acid-base balance during the pre-and perinatal phases. During the last third of incubation, regardless of the different environmental conditions which the embryos are subjected and breeder age, there is physiological responsiveness that allows for stability in acid-base balance of the chicks after hatching...


Assuntos
Animais , Embrião de Galinha , Bicarbonatos/análise , Dióxido de Carbono/análise , Galinhas/metabolismo , Gasometria/veterinária , Hidrogênio/análise , Oxigênio/análise , Equilíbrio Hidroeletrolítico , Distribuição por Idade , Análise de Variância
17.
Artif Organs ; 38(10): 883-8, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24393008

RESUMO

This work is focused on the problem of maintenance of intradialytic hemodynamic safety in unstable patients with acute kidney injury (AKI). A hypothesis that "small" quantities of acetate in standard bicarbonate dialysate can cause pronounced acetatemia and exacerbate cardiovascular instability was tested. In this prospective randomized study, a group of patients with AKI after cardiac surgery was treated with sustained low-efficiency dialysis with either acetate-containing bicarbonate dialysate or acetate-free dialysate, where acetate is replaced by hydrochloric acid. It was demonstrated that application of acetate-containing bicarbonate dialysate results in blood acetate levels up to 12 times the normal level. Additionally, it is associated with a 3.8-fold-increased risk of hemodynamic complications in comparison with acetate-free dialysate. The choice of acetate-free or acetate-containing bicarbonate dialysate does not influence adequacy of correction of the acid-base and electrolyte content of blood.


Assuntos
Ácido Acético/análise , Injúria Renal Aguda/terapia , Bicarbonatos/análise , Soluções para Hemodiálise/química , Diálise Renal/métodos , Injúria Renal Aguda/fisiopatologia , Idoso , Feminino , Hemodinâmica/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
18.
São Paulo; s.n; s.n; 2014. 145 p. tab, graf, ilus.
Tese em Português | LILACS | ID: biblio-847279

RESUMO

Bicarbonato é uma importante espécie química para os seres vivos, sendo o principal tampão celular, alem de apresentar uma negligenciada atividade redox. Isquemia é um evento no qual existe inibição do aporte de nutrientes e oxigênio, sendo a reperfusão o retorno do fluxo de nutrientes e oxigênio, que é acompanhada por alta produção de radicais livres e morte celular. Nessa tese estudamos o efeito da presença de bicarbonato durante a isquemia-reperfusão. Em nosso modelo nós mantivemos o pH constante e modulamos a quantidade de bicarbonato enquanto células, órgãos e animais foram submetidos a isquemia-reperfusão. Utilizamos condições sem a presença de bicarbonato, a concentração basal sanguínea e uma concentração mais alta simulando o acúmulo de bicarbonato em condições isquêmicas. Nesses diversos modelos mostramos que a presença de bicarbonato aumenta o dano provocado por isquemia-reperfusão e provoca um aumento do acúmulo de proteínas oxidadas. A presença do bicarbonato não modifica a respiração, produção de espécies reativas de oxigênio, ou a morfologia mitocondrial, também não detectamos mudança na atividade do proteassoma e nos indicadores de autofagia geral. Entretanto detectamos um acúmulo de marcadores autofágicos na fração mitocondrial indicando inibição da mitofagia. Essa inibição foi confirmada ao detectarmos o acúmulo de uma proteína degradada especificamente por mitofagia enquanto não houve mudança em outra degradada pelo proteassoma. Além disso, ao inibirmos farmacologicamente a autofagia, reproduzimos o fenótipo causado pelo bicarbonato mesmo na sua ausência. Em conclusão, a presença de bicarbonato é deletéria em condições de isquemia/reperfusão devido a inibição da mitofagia


Bicarbonate is an important molecule in all living being, acting as the main cellular buffer. However, its biological and redox activity has been mostly neglected to date. Ischemia is an event in which an inhibition of nutrient availablity and oxygen flow occurs, while reperfusion is the return of nutrients and oxygen, accompanied of a burst of reactive oxygen species production and cell death. Here, we studied the effects of bicarbonate during cardiac ischemia-reperfusion. In our model, we kept the pH stable and changed the concentration of the bicarbonate. We then subjected cells, organs and animals to ischemia-reperfusion under conditions where there was no presence, basal blood concentration or a higher concentration of bicarbonate. In these diverse models, we found that the presence of bicarbonate increased damage after a ischemia-reperfusion, and promoted the accumulation of oxidized proteins. Bicarbonate did not change respiration, production of reactive oxygen species or the morphology of the mitochondria. There were also no changes in proteasome activity and in global autophagy markers, although there was an accumulation of mitophagy markers. We also found that mitophagy was responsible for the increased damage observed, since pharmacological inhibiting of autophagy abolished the increased damage caused by the presence of bicarbonate. In conclusion the presence of bicarbonate is deleterious in ischemia-reperfusion due mitophagy inhibition


Assuntos
Animais , Masculino , Feminino , Ratos , Bicarbonatos/análise , Dióxido de Carbono/análise , Isquemia/fisiopatologia , Mitocôndrias , Mitofagia , Reperfusão
19.
Pancreas ; 42(7): 1101-6, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23921960

RESUMO

OBJECTIVES: Clinical and morphological criteria are not precise enough to diagnose early chronic pancreatitis (CP). We investigated if short endoscopic pancreas function testing as a part of routine upper endoscopy could improve clinical diagnostics. METHODS: Patients with suspected CP underwent modified secretin-stimulated upper endoscopy (short endoscopic secretin test, or EST). Duodenal juice was collected during 15 minutes starting 30 minutes after stimulation. A modified scoring system for CP after Layer with bicarbonate and fecal elastase 1 (FE1) was used. We tested with receiver operating characteristic curves the diagnostic accuracy of bicarbonate and FE1 and with analysis of variance how precise the 2 parameters can discriminate the groups. RESULTS: Fifty-two patients aged 19 to 67 years and 25 healthy controls aged 19 to 64 years were included. Twenty-four patients fulfilled the modified Layer Score for CP or non-CP. The overall accuracy of the EST versus FE1 test was 85%/71%, with positive and negative predictive values of 100%/79% and 80%/69%, respectively. CONCLUSIONS: Short EST is rapid and easy to perform and can be incorporated in daily routines. We demonstrate that EST is superior to FE1 in the assessment of pancreatic insufficiency and may prove to be useful in diagnosing early or mild CP.


Assuntos
Testes de Função Pancreática/métodos , Pancreatite Crônica/diagnóstico , Secretina , Adulto , Idoso , Bicarbonatos/análise , Estudos de Casos e Controles , Endoscopia do Sistema Digestório , Fezes/enzimologia , Feminino , Humanos , Secreções Intestinais/química , Masculino , Pessoa de Meia-Idade , Elastase Pancreática/análise , Testes de Função Pancreática/estatística & dados numéricos , Fatores de Tempo , Adulto Jovem
20.
JOP ; 14(3): 237-42, 2013 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-23669471

RESUMO

CONTEXT: Estrogens are thought to cause pancreatitis by raising triglyceride levels but whether there are other effects on the pancreas is debatable. OBJECTIVE: To better elucidate the relationship between estrogens and pancreatitis and pancreatic function in a pilot study. DESIGN/SETTING/PATIENTS: Our retrospectively collected database of 224 patients who had undergone secretin stimulation testing was queried for females with available medication histories, who were then divided into two groups: those taking estrogens (E) and those not on estrogens (N). Mann Whitney U and Fisher's exact tests were used. RESULTS: Seventy of the patients in the database were females with available medication histories. Thirty-five (50.0%) were taking estrogens. Twenty-nine (82.9%) of the E patients experienced any type of pancreatitis (i.e., acute pancreatitis, acute relapsing pancreatitis, chronic pancreatitis) while only 19 (54.3%) of the N patients did (P=0.019). During secretin stimulation testing, the peak bicarbonate levels for E and N patients were 80±18 and 90±23 mEq/L, respectively (P=0.058). When patients with any type of pancreatitis were excluded, E patients still displayed decreased peak bicarbonate levels in response to secretin (90±18 vs. 104±19 mEq/L; P=0.021). Weight, age, triglyceride levels, frequency of patients with cholecystectomy and biliary stones did not significantly differ between the two groups (E and N respectively). CONCLUSIONS: These pilot data suggest exogenous estrogens may be related to the development of acute pancreatitis and acute relapsing pancreatitis, and probably to a lesser degree chronic pancreatitis, perhaps through a triglyceride independent mechanism. During secretin stimulation testing, peak bicarbonate production may be diminished in women on estrogens (even in those who have never had pancreatitis). Further study is necessary to better define the relationship between estrogen use, pancreatitis, and pancreatic function.


Assuntos
Dor Abdominal/induzido quimicamente , Estrogênios/efeitos adversos , Pâncreas/efeitos dos fármacos , Pancreatite/induzido quimicamente , Adulto , Bicarbonatos/análise , Doença Crônica , Feminino , Humanos , Pessoa de Meia-Idade , Pâncreas/patologia , Pâncreas/fisiopatologia , Testes de Função Pancreática , Pancreatite/diagnóstico , Projetos Piloto , Estudos Retrospectivos , Fatores de Risco , Secretina
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA