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2.
Cells ; 11(13)2022 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-35805121

RESUMO

The overexpression of the Orai1 channel inhibits SOCE when using the Ca2+ readdition protocol. However, we found that HeLa cells overexpressing the Orai1 channel displayed enhanced Ca2+ entry and a limited ER depletion in response to the combination of ATP and thapsigargin (TG) in the presence of external Ca2+. As these effects require the combination of an agonist and TG, we decided to study whether the phosphorylation of Orai1 S27/S30 residues had any role using two different mutants: Orai1-S27/30A (O1-AA, phosphorylation-resistant) and Orai1-S27/30D (O1-DD, phosphomimetic). Both O1-wt and O1-AA supported enhanced Ca2+ entry, but this was not the case with O1-E106A (dead-pore mutant), O1-DD, and O1-AA-E106A, while O1-wt, O1-E106A, and O1-DD inhibited the ATP and TG-induced reduction of ER [Ca2+], suggesting that the phosphorylation of O1 S27/30 interferes with the IP3R activity. O1-wt and O1-DD displayed an increased interaction with IP3R in response to ATP and TG; however, the O1-AA channel decreased this interaction. The expression of mCherry-O1-AA increased the frequency of ATP-induced sinusoidal [Ca2+]i oscillations, while mCherry-O1-wt and mCherry-O1-DD decreased this frequency. These data suggest that the combination of ATP and TG stimulates Ca2+ entry, and the phosphorylation of Orai1 S27/30 residues by PKC reduces IP3R-mediated Ca2+ release.


Assuntos
Canais de Cálcio , Cálcio , Trifosfato de Adenosina/metabolismo , Trifosfato de Adenosina/farmacologia , Cálcio/metabolismo , Canais de Cálcio/metabolismo , Células HeLa , Humanos , Proteína ORAI1/metabolismo , Fosforilação , Proteína Quinase C/metabolismo , Tapsigargina/farmacologia
3.
Handb Exp Pharmacol ; 2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35768554

RESUMO

Various human tissues express the calcium-activated chloride channel Anoctamin 1 (ANO1), also known as TMEM16A. ANO1 allows the passive chloride flux that controls different physiological functions ranging from muscle contraction, fluid and hormone secretion, gastrointestinal motility, and electrical excitability. Overexpression of ANO1 is associated with pathological conditions such as hypertension and cancer. The molecular cloning of ANO1 has led to a surge in structural, functional, and physiological studies of the channel in several tissues. ANO1 is a homodimer channel harboring two pores - one in each monomer - that work independently. Each pore is activated by voltage-dependent binding of two intracellular calcium ions to a high-affinity-binding site. In addition, the binding of phosphatidylinositol 4,5-bisphosphate to sites scattered throughout the cytosolic side of the protein aids the calcium activation process. Furthermore, many pharmacological studies have established ANO1 as a target of promising compounds that could treat several illnesses. This chapter describes our current understanding of the physiological roles of ANO1 and its regulation under physiological conditions as well as new pharmacological compounds with potential therapeutic applications.

4.
Artigo em Inglês | MEDLINE | ID: mdl-35202806

RESUMO

The calcium-activated chloride channel TMEM16A (ANO1) supports the passive movement of chloride ions across membranes and controls critical cell functions. Here we study the block of wild-type and mutant TMEM16A channels expressed in HEK293 cells by oleic acid, a monounsaturated omega-9 fatty acid beneficial for cardiovascular health. We found that oleic acid irreversibly blocks TMEM16A in a dose- and voltage-dependent manner at low intracellular Ca2+. We tested whether oleic acid interacted with the TMEM16A pore, varying the permeant anion concentration and mutating pore residues. Lowering the permeating anion concentration in the intracellular side did nothing but the blockade was intensified by increasing the anion concentration in the extracellular side. However, the blockade of the pore mutants E633A and I641A was voltage-independent, and the I641A IC50, a mutant with the inner hydrophobic gate in disarray, increased 16-fold. Furthermore, the uncharged methyl-oleate blocked 20-24% of the wild-type and I641A channels regardless of voltage. Our findings suggest that oleic acid inhibits TMEM16A by an allosteric mechanism after the electric field drives oleic acid's charged moiety inside the pore. Block of TMEM16A might be why oleic acid has a beneficial impact on the cardiovascular system.


Assuntos
Canais de Cloreto , Ácido Oleico , Ânions/metabolismo , Anoctamina-1/genética , Anoctamina-1/metabolismo , Cálcio/metabolismo , Canais de Cloreto/química , Canais de Cloreto/genética , Canais de Cloreto/metabolismo , Células HEK293 , Humanos , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Ácido Oleico/farmacologia
5.
J Mol Histol ; 51(6): 701-716, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33070272

RESUMO

The kidney controls body fluids, electrolyte and acid-base balance. Previously, we demonstrated that hyperpolarization-activated and cyclic nucleotide-gated (HCN) cation channels participate in ammonium excretion in the rat kidney. Since acid-base balance is closely linked to potassium metabolism, in the present work we aim to determine the effect of chronic metabolic acidosis (CMA) and hyperkalemia (HK) on protein abundance and localization of HCN3 in the rat kidney. CMA increased HCN3 protein level only in the outer medulla (2.74 ± 0.31) according to immunoblot analysis. However, immunofluorescence assays showed that HCN3 augmented in cortical proximal tubules (1.45 ± 0.11) and medullary thick ascending limb of Henle's loop (4.48 ± 0.45) from the inner stripe of outer medulla. HCN3 was detected in brush border membranes (BBM) and mitochondria of the proximal tubule by immunogold electron and confocal microscopy in control conditions. Acidosis did not alter HCN3 levels in BBM and mitochondria but augmented them in lysosomes. HCN3 was also immuno-detected in mitoautophagosomes. In the distal nephron, HCN3 was expressed in principal and intercalated cells from cortical to medullary collecting ducts. CMA did not change HCN3 abundance in these nephron segments. In contrast, HK doubled HCN3 level in cortical collecting ducts and favored its basolateral localization in principal cells from the inner medullary collecting ducts. These findings further support HCN channels contribution to renal acid-base and potassium balance.


Assuntos
Acidose/etiologia , Acidose/metabolismo , Hiperpotassemia/etiologia , Hiperpotassemia/metabolismo , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/metabolismo , Néfrons/metabolismo , Canais de Potássio/metabolismo , Animais , Biomarcadores , Doença Crônica , Células Epiteliais/metabolismo , Imunofluorescência/métodos , Expressão Gênica , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/genética , Túbulos Renais Proximais/metabolismo , Alça do Néfron/metabolismo , Néfrons/ultraestrutura , Canais de Potássio/genética , Ratos
6.
Biochem Biophys Res Commun ; 524(4): 1030-1036, 2020 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-32063359

RESUMO

The hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are encoded by a family of four genes (HCN1-4). All isoforms are expressed in the heart, HCN4 being the most abundant in the sinoatrial node (SAN). HCN channels are responsible for the "funny" current (If) associated with the generation and autonomic control of the diastolic depolarization phase of cardiac action potential. In this work we performed a proteomic analysis of HCN4 transfected in HEK293 cells. Most of the identified proteins in the HCN4 network belonged to mitochondria. The subcellular localization of HCN channels was predicted in plasma membrane, mitochondria and nucleus. Experimentally, HCN2 (full-length, truncated), HCN3 (full-length, truncated) and HCN4 (truncated) were detected in rat heart mitochondria by immunoblotting. If sensitive to ZD7288, was recorded by patch-clamp in mitoplasts from cardiomyocytes. Mitochondrial membrane potential (ΔΨm) assessment in H9c2 cells revealed that ZD7288 induced almost 50% higher hyperpolarization respect to control at 30 min. Furthermore, ZD7288 reduced oxygen consumption attributed to ATP synthesis in H9c2 cells. In conclusion, we identify for the first time functional HCN channels in mammalian cardiac mitochondria and demonstrate their impact on ΔΨm and respiration.


Assuntos
Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/metabolismo , Potencial da Membrana Mitocondrial , Mitocôndrias Cardíacas/metabolismo , Consumo de Oxigênio , Animais , Linhagem Celular , Células HEK293 , Humanos , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/análise , Camundongos Endogâmicos BALB C , Miócitos Cardíacos/metabolismo , Ratos Wistar
7.
Int J Mol Sci ; 20(20)2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31601020

RESUMO

Hyperpolarization-activated cationic HCN channels comprise four members (HCN1-4) that control dendritic integration, synaptic transmission and action potential firing. In the kidney, HCN1, HCN2 and HCN3 are differentially expressed and contribute to the transport of sodium, potassium (K+) and ammonium into the nephrons. HCN3 is regulated by K+ diets in the kidney. In this work we performed a proteomic analysis of HCN3 expressed in human embryonic kidney cells (HEK293 cells). More than 50% of the interacting proteins belonged to mitochondria. Therefore, we explored the presence of HCN channels in kidney mitochondria. By immunoblotting and immunogold electron microscopy HCN3 protein expression was found in rat kidney mitochondria; it was also confirmed in human kidney. Patch-clamp recordings of renal mitochondria and mitochondria from HEK293 cells overexpressing HCN1, HCN2 and HCN3 channels, stained with MitoTracker Green FM, indicated that only HCN3 could produce inwardly K+ currents that were inhibited by ZD7288, a specific blocker of HCN channels. Furthermore, ZD7288 caused inhibition of the oxygen consumption coupled to ATP synthesis and hyperpolarization of the inner mitochondrial membrane. In conclusion, we show for the first time that pacemaker HCN channels contribute to K+ transport in mitochondria facilitating the activity of the respiratory chain and ATP synthesis by controlling the inner mitochondrial membrane potential.


Assuntos
Rim/metabolismo , Mitocôndrias/metabolismo , Canais de Potássio/metabolismo , Potenciais de Ação , Respiração Celular , Cromatografia Líquida , Ativação do Canal Iônico , Mitocôndrias/genética , Nucleotídeos Cíclicos/metabolismo , Proteoma , Proteômica/métodos , Espectrometria de Massas em Tandem
8.
Nutrients ; 11(7)2019 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-31261732

RESUMO

Oral diabetes-specific nutritional supplements (ONS-D) induce favourable postprandial responses in subjects with type 2 diabetes (DM2), but they have not been correlated yet with incretin release and subjective appetite (SA). This randomised, double-blind, cross-over study compared postprandial effects of ONS-D with isomaltulose and sucromalt versus standard formula (ET) on glycaemic index (GI), insulin, glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide 1 (GLP-1) and SA in 16 individuals with DM2. After overnight fasting, subjects consumed a portion of supplements containing 25 g of carbohydrates or reference food. Blood samples were collected at baseline and at 30, 60, 90, 120, 150 and 180 min; and SA sensations were assessed by a visual analogue scale on separate days. Glycaemic index values were low for ONS-D and intermediate for ET (p < 0.001). The insulin area under the curve (AUC0-180 min) (p < 0.02) and GIP AUC (p < 0.02) were lower after ONS-D and higher GLP-1 AUC when compared with ET (p < 0.05). Subjective appetite AUC was greater after ET than ONS-D (p < 0.05). Interactions between hormones, hunger, fullness and GI were found, but not within the ratings of SA; isomaltulose and sucromalt may have influenced these factors.


Assuntos
Regulação do Apetite , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/dietoterapia , Suplementos Nutricionais , Dissacarídeos/administração & dosagem , Frutose/administração & dosagem , Índice Glicêmico , Isomaltose/administração & dosagem , Hormônios Peptídicos/sangue , Administração Oral , Biomarcadores/sangue , Estudos Cross-Over , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/fisiopatologia , Diabetes Mellitus Tipo 2/psicologia , Dissacarídeos/efeitos adversos , Método Duplo-Cego , Feminino , Frutose/efeitos adversos , Polipeptídeo Inibidor Gástrico/sangue , Peptídeo 1 Semelhante ao Glucagon/sangue , Humanos , Insulina/sangue , Isomaltose/efeitos adversos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Resultado do Tratamento
9.
Rep Pract Oncol Radiother ; 24(2): 142-150, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30723385

RESUMO

AIM: To evaluate dose differences in lung metastases treated with stereotactic body radiotherapy (SBRT), and the correlation with local control, regarding the dose algorithm, target volume and tissue density. BACKGROUND: Several studies showed excellent local control rates in SBRT for lung metastases, with different fractionation schemes depending on the tumour location or size. These results depend on the dose distributions received by the lesions in terms of the tissue heterogeneity corrections performed by the dose algorithms. MATERIALS AND METHODS: Forty-seven lung metastases treated with SBRT, using intrafraction control and respiratory gating with internal fiducial markers as surrogates (ExacTrac, BrainLAB AG), were calculated using Pencil Beam (PB) and Monte Carlo (MC) (iPlan, BrainLAB AG).Dose differences between both algorithms were obtained for the dose received by 99% (D 99%) and 50% (D 50%) of the planning treatment volume (PTV). The biologically effective dose delivered to 99% (BED99%) and 50% (BED50%) of the PTV were estimated from the MC results. Local control was evaluated after 24 months of median follow-up (range: 3-52 months). RESULTS: The greatest variations (40.0% in ΔD 99% and 38.4% in ΔD 50%) were found for the lower volume and density cases. The BED99% and BED50% were strongly correlated with observed local control rates: 100% and 61.5% for BED99% > 85 Gy and <85 Gy (p < 0.0001), respectively, and 100% and 58.3% for BED50% > 100 Gy and <100 Gy (p < 0.0001), respectively. CONCLUSIONS: Lung metastases treated with SBRT, with delivered BED99% > 85 Gy and BED50% > 100 Gy, present better local control rates than those treated with lower BED values (p = 0.001).

10.
Nutr. hosp ; 34(6): 1455-1462, nov.-dic. 2017. graf, tab
Artigo em Espanhol | IBECS | ID: ibc-168988

RESUMO

Actualmente la industria alimentaria ha generado interés en edulcorantes no nutritivos, por ejemplo la estevia y en componentes especiales como la L-carnitina, utilizados en formulaciones de suplementos nutricionales para el control glicémico específicos para diabéticos. El presente estudio evaluó el efecto de la estevia y la L-carnitina sobre el índice glicémico (IG) y la carga glicémica (CG) de un suplemento nutricional en 19 sujetos sanos (9 hombres y 10 mujeres), quienes completaron aleatoriamente 3 pruebas de consumo, 1 para el suplemento y 1 para cada producto de referencia: solución glucosada (SG) y pan blanco (PB), obteniendo muestras de sangre a los tiempos 0, 15, 30, 45, 60, 90 y 120 min; para medición de glicemias, e insulina basal y postprandial. El área de incremento bajo la curva de glucosa (IAUC) fue menor para el suplemento 11.778,73 que para los productos de referencia (SG) 13.724,06; (PB) 13.153,56 α = p 0,005. El IG = (62) y la CG = (16) resultaron intermedios y más bajos que el del pan blanco IG = (69) y la CG = (18), sin diferencias en la insulina postprandial. Esto demuestra que este suplemento nutricional formulado con estevia y L-carnitina es capaz de prolongar la respuesta glicémica sin aumentar los requerimientos insulínicos en sujetos sanos. Se requieren estudios específicos en diabéticos para validar si el impacto glicémico es menor que el producto patrón. La presencia de otros nutrientes en la fórmula, influyentes en estos indicadores, no permite inferir que los resultados se deban únicamente al tipo de endulzante utilizado y a la L-carnitina (AU)


Currently the food industry has generated interest in non-nutritive sweeteners, for example Stevia and in special components such as L-carnitine, used in formulations of nutritional supplements for glycemic control specific for diabetics. The present study evaluated the effect of stevia and L-carnitine on the glycemic index (GI) and glycemic load (CG) of a nutritional supplement in 19 healthy subjects (9 men and 10 women), who randomly completed 3 consumption tests, 1 for the supplement and 1 for each reference product: Glucose solution (SG) and white bread (PB), obtaining blood samples at the 0, 15, 30, 45, 60, 90 and 120 min times; for measurement of blood glucose, basal and postprandial insulin. The increase area under the glucose curve (IAUC) was lower for supplement 11,778.73 than for reference products (SG) 13,724.06; (PB) 13,153.56 α = p 0.005. IG = (62) and CG = (16) were intermediate and lower than white bread IG = (69) and CG = (18), with no difference in postprandial insulin. This demonstrates that this nutritional supplement formulated with stevia and L-carnitine is able to prolong the glycemic response without increasing the insulin requirements in healthy subjects. Specific studies are required in diabetics to validate whether the glycemic impact is lower than the standard product. The presence of other nutrients in the formula, influential in these indicators, does not allow to infer that the results are due only to the type of sweetener used and the L-carnitine (AU)


Assuntos
Humanos , Masculino , Feminino , Adulto , Índice Glicêmico , Glicemia , Suplementos Nutricionais , Carnitina/uso terapêutico , Edulcorantes/metabolismo , Método Duplo-Cego , Estado Nutricional/fisiologia , Índice de Massa Corporal , Antropometria/métodos , 28599
11.
Rep Pract Oncol Radiother ; 22(2): 150-157, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28490986

RESUMO

AIM: To report the outcome and toxicity of sequential stereotactic body radiotherapy (SBRT) for multiple liver metastases in patients treated with ExacTrac Adaptive Gating. BACKGROUND: In selected patients with a limited number of liver metastases, SBRT has been evaluated as a safe and effective treatment, with minimal toxicity and high rates of local control. MATERIALS AND METHODS: From April 2008 to October 2013, 21 patients with multiple (3-14) liver metastases (n = 101) were treated sequentially with SBRT at our institution. Maximum tumor diameter was 7.5 cm. Prior to treatment, internal markers were placed inside or near the tumor. CT or PET-CT simulation was used for the definition of gross tumor volume (GTV). Median planning target volume was 32.3 cc (3.6-139.3 cc). Treatment consisted of 3 fractions (12-20 Gy/fraction) or 5 fractions (10 Gy/fraction), prescribed to the 90-95% of the PTV volume. Daily intra-fraction image guidance was performed with ExacTrac Adaptive Gating. Regular follow-up included CT or PET-CT imaging. RESULTS: After a median of 23.2 months, the estimated local control rate was 94.4%, 80.6%, 65% and 65% after 1, 2, 3 and 4 years; the median overall survival was 62 months (95% CI 49.12-74.87) and the actuarial survival reached at 60 months was 57.6%. The univariate data analysis revealed that only primary histology other than colorectal adenocarcinoma was shown as an independent significant prognostic factor for local control (p = 0.022). Number of treated metastases did not modify significantly the overall survival (p = 0.51). No toxicity higher than G3 (1 patient with chest wall pain) and no radiation-induced liver disease were observed. CONCLUSIONS: Sequential SBRT with ExacTrac Adaptive Gating for multiple liver metastases can be considered an effective, safe therapeutic option, with a low treatment-related toxicity. Excellent rates of local control and survival were obtained.

12.
Cell Calcium ; 65: 80-90, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28249687

RESUMO

It has been shown that 2-APB is a nonspecific modulator of ion channel activity, while most of the channels are inhibited by this compound, there are few examples of channels that are activated by 2-APB. Additionally, it has been shown that, 2-APB leads to a reduction in the luminal endoplasmic reticulum Ca2+ level ([Ca2+]ER) and we have carried out simultaneous recordings of both [Ca2+]i and the [Ca2+]ER in HeLa cell suspensions to assess the mechanism involved in this effect. This approach allowed us to determine that 2-APB induces a reduction in the [Ca2+]ER by activating an ER-resident Ca2+ permeable channel more than by inhibiting the activity of SERCA pumps. Interestingly, this effect of 2-APB of reducing the [Ca2+]ER is auto-limited because depends on a replete ER Ca2+ store; a condition that thapsigargin does not require to decrease the [Ca2+]ER. Additionally, our data indicate that the ER Ca2+ permeable channel activated by 2-APB does not seem to participate in the ER Ca2+ leak revealed by inhibiting SERCA pump with thapsigargin. This work suggests that, prolonged incubations with even low concentrations of 2-APB (5µM) would lead to the reduction in the [Ca2+]ER that might explain the inhibitory effect of this compound on those signals that require Ca2+ release from the ER store.


Assuntos
Compostos de Boro/farmacologia , Sinalização do Cálcio/efeitos dos fármacos , Cálcio/metabolismo , Retículo Endoplasmático/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/antagonistas & inibidores , Células HeLa , Humanos , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Tapsigargina/farmacologia
13.
Cell Calcium ; 65: 91-101, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28179072

RESUMO

We have studied in HeLa cells the molecular nature of the 2-APB induced ER Ca2+ leak using synthetic Ca2+ indicators that report changes in both the cytoplasmic ([Ca2+]i) and the luminal ER ([Ca2+]ER) Ca2+ concentrations. We have tested the hypothesis that Orai channels participate in the 2-APB-induced ER Ca2+ leak that was characterized in the companion paper. The expression of the dominant negative Orai1 E106A mutant, which has been reported to block the activity of all three types of Orai channels, inhibited the effect of 2-APB on the [Ca2+]ER but did not decrease the ER Ca2+ leak after thapsigargin (TG). Orai3 channel, but neither Orai1 nor Orai2, colocalizes with expressed IP3R and only Orai3 channel supported the 2-APB-induced ER Ca2+ leak, while Orai1 and Orai2 inhibited this type of ER Ca2+ leak. Decreasing the expression of Orai3 inhibited the 2-APB-induced ER Ca2+ leak but did not modify the ER Ca2+ leak revealed by inhibition of SERCA pumps with TG. However, reducing the expression of Orai3 channel resulted in larger [Ca2+]i response after TG but only when the ER store had been overloaded with Ca2+ by eliminating the acidic internal Ca2+ store with bafilomycin. These data suggest that Orai3 channel does not participate in the TG-revealed ER Ca2+ leak but forms an ER Ca2+ leak channel that is limiting the overloading with Ca2+ of the ER store.


Assuntos
Compostos de Boro/farmacologia , Canais de Cálcio/metabolismo , Sinalização do Cálcio/efeitos dos fármacos , Cálcio/metabolismo , Retículo Endoplasmático/metabolismo , Células HeLa , Humanos , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Tapsigargina/farmacologia
14.
Arch. latinoam. nutr ; 66(2): 113-120, June 2016. tab, graf
Artigo em Espanhol | LILACS, LIVECS | ID: lil-785930

RESUMO

Existen fórmulas enterales específicas para mejorar el control glicémico en diabéticos; con carbohidratos cuya respuesta glicémica sería de interés indagar. Se determinó el efecto del consumo de una fórmula con carbohidratos de liberación prolongada sobre la respuesta glicémica e insulina post-prandial en 21 sujetos sanos; (11 hombres y 10 mujeres) entre (17 y 25 años), quienes consumieron en 2 ocasiones la fórmula enteral polimérica para diabéticos y el alimento de referencia (pan blanco), en una cantidad de 50 g de carbohidratos disponibles. La glicemia fue medida a los 0, 15, 30,45, 60, 75, 90, 105 y 120 min y las concentraciones de insulina en ayuno y a los 120 min. El área bajo la curva de glicemia fue calculada resultando más baja para la fórmula 11718,20. ± 1112,38 que para el pan blanco 13269,18 ± 1351,05, (p<0,001). El índice glicémico (IG) resultó intermedio (63,33±5,22), y más bajo al compararlo con los rangos de IG publicados para el alimento de referencia(80-96). Se produjo una menor concentración de glicemia posterior al consumo de la fórmula; sin incrementos en los requerimientos de insulina, presumiendo un uso adecuado en diabéticos y una respuesta de saciedad más prolongada. Este efecto y la hemoglobina glicosilada deberían estudiarse tras el consumo en períodos prolongados en sujetos con diabetes(AU)


There are specific formulas of enteral nutrition to improve glycemic control in diabetic patients containing different types of carbohydrates which glycemic response should be investigated. The consumption effect of a formula with carbohydrates with extended release was determined on the glycemic response and postprandial insulin in 21 healthy individuals (11 men and 10 women) from 17 to 25 years old, who consumed in two different time the polymeric enteral formula for diabetics and the reference food (white bread) in a quantity of 50 g of available carbohydrates. The glycemia was measured at 0, 15, 30, 45, 60, 75, 90, 105 and 120 min and the insulin concentrations in fasting and within 120 min. The area in the glycemic curve was measured being the lowest the formula 11718.20. ± 1112.38 than in white bread 13269.18 ± 1351.05 (P<0.001). The glycemic index (GI) resulted to be intermediate (63.33±5.22) and lower when compared to the GI ranks published for the reference food (80-96). A lower concentration of glycemia occurred after the consumption of the formula, without increments in the insulin requirements; thus, assuming an adequate use in diabetic and a more extended feeling of fullness. This effect and the glycated hemoglobin should be studied after the extended consumption in people with diabetes(AU)


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Carboidratos , Nutrição Enteral , Índice Glicêmico , Insulina/análise , Análise Química do Sangue , Técnicas de Laboratório Clínico , Diabetes Mellitus Tipo 2
15.
Arch Latinoam Nutr ; 66(2): 113-120, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29737667

RESUMO

There are specific formulas of enteral nutrition to improve glycemic control in diabetic patients containing different types of carbohydrates which glycemic response should be investigated. The consumption effect of a formula with carbohydrates with extended release was determined on the glycemic response and postprandial insulin in 21 healthy individuals (11 men and 10 women) from 17 to 25 years old, who consumed in two different time the polymeric enteral formula for diabetics and the reference food (white bread) in a quantity of 50 g of available carbohydrates. The glycemia was measured at 0, 15, 30, 45, 60, 75, 90, 105 and 120 min and the insulin concentrations in fasting and within 120 min. The area in the glycemic curve was measured being the lowest the formula 11718.20. ± 1112.38 than in white bread 13269.18 ± 1351.05 (P<0.001). The glycemic index (GI) resulted to be intermediate (63.33±5.22) and lower when compared to the GT ranks published for the reference food (80-96). A lower concentration of glycemia occurred after the consumption of the formula, without increments in the insulin requirements; thus, assuming an adequate use in diabetic and a more extended feeling of fullness. This effect and the glycated hemoglobin should be studied after the extended consumption in people with diabetes.


Assuntos
Carboidratos da Dieta/farmacocinética , Alimentos Formulados , Índice Glicêmico/fisiologia , Insulina/sangue , Período Pós-Prandial/fisiologia , Adolescente , Adulto , Análise de Variância , Área Sob a Curva , Glicemia/análise , Estudos Transversais , Preparações de Ação Retardada , Diabetes Mellitus/metabolismo , Jejum/sangue , Feminino , Humanos , Masculino , Valores de Referência , Fatores Sexuais , Estatísticas não Paramétricas , Fatores de Tempo , Adulto Jovem
16.
Cell Calcium ; 56(5): 311-22, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25239386

RESUMO

The endoplasmic reticulum is the main intracellular Ca(2+) store for Ca(2+) release during cell signaling. There are different strategies to avoid ER Ca(2+) depletion. Release channels utilize first Ca(2+)-bound to proteins and this minimizes the reduction of the free luminal [Ca(2+)]. However, if release channels stay open after exhaustion of Ca(2+)-bound to proteins, then the reduction of the free luminal ER [Ca(2+)] (via STIM proteins) activates Ca(2+) entry at the plasma membrane to restore the ER Ca(2+) load, which will work provided that SERCA pump is active. Nevertheless, there are several noxious conditions that result in decreased activity of the SERCA pump such as oxidative stress, inflammatory cytokines, and saturated fatty acids, among others. These conditions result in a deficient restoration of the ER [Ca(2+)] and lead to the ER stress response that should facilitate recovery of the ER. However, if the stressful condition persists then ER stress ends up triggering cell death and the ensuing degenerative process leads to diverse pathologies; particularly insulin resistance, diabetes and several of the complications associated with diabetes. This scenario suggests that limiting ER stress should decrease the incidence of diabetes and the mobility and mortality associated with this illness.


Assuntos
Cálcio/metabolismo , Diabetes Mellitus/genética , Estresse do Retículo Endoplasmático/genética , Resistência à Insulina/genética , Sinalização do Cálcio/genética , Diabetes Mellitus/patologia , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/patologia , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Humanos , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/genética , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo
17.
Transfusion ; 54(2): 289-99, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23581484

RESUMO

BACKGROUND: Postoperative nosocomial infection (PNI) is a severe complication in surgical patients. Known risk factors of PNI such as allogeneic blood transfusions (ABTs), anemia, and iron deficiency are manageable with perioperative intravenous (IV) iron therapy. To address potential concerns about IV iron and the risk of PNI, we studied a large series of orthopedic surgical patients for possible relations between IV iron, ABT, and PNI. STUDY DESIGN AND METHODS: Pooled data on ABT, PNI, 30-day mortality, and length of hospital stay (LHS) from 2547 patients undergoing elective lower-limb arthroplasty (n = 1186) or hip fracture repair (n = 1361) were compared between patients who received either very-short-term perioperative IV iron (200-600 mg; n = 1538), with or without recombinant human erythropoietin (rHuEPO; 40,000 IU), or standard treatment (n = 1009). RESULTS: Compared to standard therapy, perioperative IV iron reduced rates of ABT (32.4% vs. 48.8%; p = 0.001), PNI (10.7% vs. 26.9%; p = 0.001), and 30-day mortality (4.8% vs. 9.4%; p = 0.003) and the LHS (11.9 days vs. 13.4 days; p = 0.001) in hip fracture patients. These benefits were observed in both transfused and nontransfused patients. Also in elective arthroplasty, IV iron reduced ABT rates (8.9% vs. 30.1%; p = 0.001) and LHS (8.4 days vs.10.7 days; p = 0.001), without differences in PNI rates (2.8% vs. 3.7%; p = 0.417), and there was no 30-day mortality. CONCLUSION: Despite known limitations of pooled observational analyses, these results suggest that very-short-term perioperative administration of IV iron, with or without rHuEPO, in major lower limb orthopedic procedures is associated with reduced ABT rates and LHS, without increasing postoperative morbidity or mortality.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Anemia Ferropriva/mortalidade , Transfusão de Sangue/estatística & dados numéricos , Infecção Hospitalar/mortalidade , Ferro/administração & dosagem , Procedimentos Ortopédicos/mortalidade , Idoso , Idoso de 80 Anos ou mais , Infecção Hospitalar/prevenção & controle , Eritropoetina/administração & dosagem , Feminino , Hematínicos/administração & dosagem , Humanos , Injeções Intravenosas , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Morbidade , Estudos Observacionais como Assunto , Período Perioperatório/mortalidade , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Reação Transfusional
18.
Am J Ther ; 17(3): 263-73, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20479580

RESUMO

Lipoprotein (a) [Lp(a)] was discovered by Kare Berg in 1963 from the study of low-density lipoprotein genetic variants. Lp(a) contains a unique protein, apolipoprotein(a), which is linked to the Apo B-100 through a disulfide bond that gives it a great structural homology with plasminogen, and confers it atherogenic and atherothrombotic properties. Interest in Lp(a) has increased because an important association between high plasma levels of Lp(a) and coronary artery disease and cerebral vascular disorders has been demonstrated. Numerous case control studies have confirmed that hyper-Lp(a) is a risk factor for premature cardiovascular disease. Lp(a) is identified as a genetic trait with autosomal transmission, codified by one of the most studied polymorphic genes in humans. It has been demonstrated that variations in this gene are a major factor in the serum levels of Lp(a). Variations differ considerably between individuals and sex across populations. Various approaches to drug treatment using fibric acid derivatives, growth hormone, insulin-like growth factor-1, alcohol extracted soy protein, niacin, and exercise have been proven to decrease Lp(a) in high risk patients, but none has really been an effective therapeutic option for successfully reducing Lp(a) plasma levels.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Hiperlipoproteinemias/complicações , Lipoproteína(a)/sangue , Doenças Cardiovasculares/etiologia , Transtornos Cerebrovasculares/etiologia , Transtornos Cerebrovasculares/prevenção & controle , Doença da Artéria Coronariana/etiologia , Doença da Artéria Coronariana/prevenção & controle , Feminino , Humanos , Hiperlipoproteinemias/tratamento farmacológico , Lipoproteína(a)/efeitos dos fármacos , Lipoproteína(a)/genética , Masculino , Polimorfismo Genético , Fatores de Risco
19.
Am J Ther ; 17(3): 284-7, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20224323

RESUMO

Latent Autoimmune Diabetes in Adults (LADA) is an autoimmune endocrine disorder in which despite the presence of antipancreatic islets antibodies in the moment of diagnostics, the progression to beta-cell secretory insufficiency is slow. It is often confused with others types of diabetes and therefore the management is frequently inadequate. We report a clinical case of a 23-year-old man with diagnosis of type 2 diabetes since 6 months ago, poorly controlled with a sulfonylurea, who initially presented 2 months ago from polyuria, polydipsia, and asthenia and 6 kg weight loss. History of past illness was negative, however, his mother relates exclusive breastfeeding during the first 15 days of life and later (until the 6 months) he was fed with infant formula (S-26). Family history revealed a first-degree relative (father) with diabetes mellitus secondary to steroid administration due to diagnosis of bone marrow hypoplasia. Also presents second-degree family history (uncle and grandfather) of type 2 diabetes mellitus. There were no pathologic findings at the physical examination. Anthropometry and laboratory tests were as follows: body mass index (BMI) = 19.66 kg/m, basal and postprandial glycemia = 108, and 276 mg/dL respectively, glycated haemoglobin = 8.9%, basal and postprandial C-peptide (2 hours) = 1.9, and 3.2 ng/mL, homeostasis model assessment of beta cell function: 87.5%, homeostasis model assessment of insulin resistance: 1.6. LADA presumptive diagnosis was confirmed with presence of autoantibodies anti-tyrosin-phosphatase and GAD65. At the time of diagnosis, individuals with LADA present an onset age <50, BMI <25 kg/m2, low magnitude postprandial and basal hyperglycemia, normal or close to normal C-peptide values, and thus not occur with acute hyperglycemic crises. Insulin therapy preserves pancreatic b-cell function, at the point that eventually prescribed insulin doses need to be reduced.


Assuntos
Autoanticorpos/sangue , Doenças Autoimunes/diagnóstico , Diabetes Mellitus/imunologia , Idade de Início , Doenças Autoimunes/imunologia , Diabetes Mellitus/diagnóstico , Diabetes Mellitus Tipo 2/diagnóstico , Humanos , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/uso terapêutico , Insulina/administração & dosagem , Insulina/uso terapêutico , Resistência à Insulina , Células Secretoras de Insulina/metabolismo , Masculino , Adulto Jovem
20.
Am J Ther ; 17(3): 341-50, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20019590

RESUMO

Coronary artery disease is the main cause of death worldwide. Lipoprotein(a) [Lp(a)], is an independent risk factor for coronary artery disease in which concentrations are genetically regulated. Contradictory results have been published about physical activity influence on Lp(a) concentration. This research aimed to determine associations between different physical activity levels and Lp(a) concentration. A descriptive and cross-sectional study was made in 1340 randomly selected subjects (males = 598; females = 712) to whom a complete clinical history, the International Physical Activity Questionnaire, and Lp(a) level determination were made. Statistical analysis was carried out to assess qualitative variables relationship by chi2 and differences between means by one-way analysis of variance considering a P value <0.05 as statistically significant. Results are shown as absolute frequencies, percentages, and mean +/- standard deviation according to case. Physical activity levels were ordinal classified as follows: low activity with 24.3% (n = 318), moderate activity with 35.0% (n = 458), and high physical activity with 40.8% (n = 534). Lp(a) concentration in the studied sample was 26.28 +/- 12.64 (IC: 25.59-26.96) mg/dL. Lp(a) concentration according to low, moderate, and high physical activity levels were 29.22 +/- 13.74, 26.27 +/- 12.91, and 24.53 +/- 11.35 mg/dL, respectively, observing statistically significant differences between low and moderate level (P = 0.004) and low and high level (P < 0.001). A strong association (chi2 = 9.771; P = 0.002) was observed among a high physical activity level and a normal concentration of Lp(a) (less than 30 mg/dL). A lifestyle characterized by high physical activity is associated with normal Lp(a) levels.


Assuntos
Estilo de Vida , Lipoproteína(a)/sangue , Atividade Motora/fisiologia , Adulto , Análise de Variância , Animais , Doença da Artéria Coronariana/epidemiologia , Doença da Artéria Coronariana/etiologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ratos , Ratos Wistar , Fatores de Risco , Inquéritos e Questionários , Venezuela , Adulto Jovem
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