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1.
J Small Anim Pract ; 64(11): 696-703, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37565533

RESUMO

OBJECTIVES: Metabolic alkalosis, although uncommon in small animals, has been previously associated with gastrointestinal obstructions. Depending on the population and disease process evaluated, previous prevalence of metabolic alkalosis is reported as ranging from 2% to 45% in canine patients. The objective of this study was to determine the prevalence of metabolic alkalosis and other acid-base and electrolyte disorders in a cohort of dogs with a confirmed upper gastrointestinal obstruction. MATERIALS AND METHODS: Electronic medical records were reviewed to identify dogs who presented for vomiting with evidence of an upper gastrointestinal obstruction from January 2015 to October 2021. Patients were enrolled only if a preoperative venous blood gas was obtained and analysed in house. Traditional acid-base analysis was utilised to determine an acid-base status before relieving the obstruction. When available, post-operative venous acid-base status was determined within 24 hours after surgery, and compared to preoperative results. RESULTS: A total of 115 dogs were included in the study. Twenty-five out of 115 (22%) dogs displayed either a simple metabolic alkalosis or a mixed acid-base disturbance before surgery. Twenty-seven out of 115 dogs (37%) had a normal acid-base status at entry. Seventy-one dogs had pre- and post-operative venous blood gas results available. Metabolic alkalosis was resolved in nearly all patients post-operatively, with no patients displaying a simple metabolic alkalosis. A mixed metabolic acidosis and respiratory alkalosis was the most common condition post-operatively, found in 25 of 71 (35%) dogs. Severe derangements of electrolytes were infrequent preoperatively (3/115; 2.6%). A majority of patients in this study exhibited hypokalaemia (64.4%), hypochloraemia (72.8%) and hyponatraemia (77.4%) on preoperative venous blood gases. Venous pH, Pv CO2 , bicarbonate and base excess were significantly higher preoperatively when compared to the post-operative results. CLINICAL SIGNIFICANCE: This study found the prevalence of pre-operative metabolic alkalosis in dogs with a documented upper gastrointestinal obstruction to be lower than previously reported. Surgical or endoscopic alleviation of the upper gastrointestinal obstruction resulted in resolution of metabolic alkalosis in nearly all patients.


Assuntos
Desequilíbrio Ácido-Base , Acidose , Alcalose , Doenças do Cão , Obstrução Intestinal , Humanos , Cães , Animais , Alcalose/veterinária , Alcalose/complicações , Desequilíbrio Ácido-Base/veterinária , Desequilíbrio Ácido-Base/metabolismo , Acidose/complicações , Acidose/veterinária , Eletrólitos , Obstrução Intestinal/veterinária , Concentração de Íons de Hidrogênio , Equilíbrio Ácido-Base , Doenças do Cão/cirurgia
2.
Int J Mol Sci ; 23(16)2022 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-36012667

RESUMO

Pannexin 1 (PANX1) was proposed to drive ATP release from red blood cells (RBCs) in response to stress conditions. Stomatin, a membrane protein regulating mechanosensitive channels, has been proposed to modulate PANX1 activity in non-erythroid cells. To determine whether stomatin modulates PANX1 activity in an erythroid context, we have (i) assessed the in situ stomatin-PANX1 interaction in RBCs, (ii) measured PANX1-stimulated activity in RBCs expressing stomatin or from OverHydrated Hereditary Stomatocytosis (OHSt) patients lacking stomatin, and in erythroid K562 cells invalidated for stomatin. Proximity Ligation Assay coupled with flow imaging shows 27.09% and 6.13% positive events in control and OHSt RBCs, respectively. The uptake of dyes 5(6)-Carboxyfluorescein (CF) and TO-PRO-3 was used to evaluate PANX1 activity. RBC permeability for CF is 34% and 11.8% in control and OHSt RBCs, respectively. PANX1 permeability for TO-PRO-3 is 35.72% and 18.42% in K562 stom+ and stom- clones, respectively. These results suggest an interaction between PANX1 and stomatin in human RBCs and show a significant defect in PANX1 activity in the absence of stomatin. Based on these results, we propose that stomatin plays a major role in opening the PANX1 pore by being involved in a caspase-independent lifting of autoinhibition.


Assuntos
Desequilíbrio Ácido-Base , Conexinas , Eritrócitos , Proteínas de Membrana , Proteínas do Tecido Nervoso , Desequilíbrio Ácido-Base/metabolismo , Trifosfato de Adenosina/metabolismo , Anemia Hemolítica Congênita , Conexinas/metabolismo , Eritrócitos/metabolismo , Eritrócitos Anormais/metabolismo , Humanos , Proteínas de Membrana/metabolismo , Erros Inatos do Metabolismo , Proteínas do Tecido Nervoso/metabolismo
3.
Am J Kidney Dis ; 78(2): 293-304, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33972146

RESUMO

Urinary diversion after cystectomy has been a historical standard for the treatment of numerous benign and malignant diseases of the bladder. Since the first published description in the early 1900s, improvements in surgical technique and a better understanding of the metabolic sequelae postoperatively have greatly enhanced patient outcomes. Both continent and incontinent diversions are available to patients after cystectomy. In appropriately selected patients, orthotopic neobladder reconstruction can offer preservation of body image and continence, and continent cutaneous diversions represent a reasonable alternative. Conduit diversion, which remains the most commonly performed diversion technique, is ideal for patients who would benefit from a less morbid surgical procedure that negates the need for self-catheterization. This installment of the Core Curriculum in Nephrology outlines numerous aspects of urinary diversion, in which a multidisciplinary approach to postoperative management at the intersection of nephrology and urology is required to effectively optimize patient outcomes. This article includes a discussion of the various reconstructive options after cystectomy as well as a comprehensive review of frequently encountered short-term and long-term metabolic abnormalities associated with altered electrolyte and acid-base homeostasis.


Assuntos
Cistectomia , Derivação Urinária , Desequilíbrio Ácido-Base/metabolismo , Desequilíbrio Ácido-Base/terapia , Diarreia/metabolismo , Diarreia/terapia , Humanos , Síndromes de Malabsorção/metabolismo , Síndromes de Malabsorção/terapia , Nefrologia , Cuidados Pós-Operatórios , Complicações Pós-Operatórias/metabolismo , Complicações Pós-Operatórias/terapia , Coletores de Urina , Urolitíase/metabolismo , Urolitíase/terapia , Urologia , Desequilíbrio Hidroeletrolítico/metabolismo , Desequilíbrio Hidroeletrolítico/terapia
4.
Biochem Pharmacol ; 183: 114278, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33039418

RESUMO

Baking soda and vinegar have been used as home remedies for generations and today we are only a mouse-click away from claims that baking soda, lemon juice, and apple cider vinegar are miracles cures for everything from cancer to COVID-19. Despite these specious claims, the therapeutic value of controlling acid-base balance is indisputable and is the basis of Food and Drug Administration-approved treatments for constipation, epilepsy, metabolic acidosis, and peptic ulcers. In this narrative review, we present evidence in support of the current and potential therapeutic value of countering local and systemic acid-base imbalances, several of which do in fact involve the administration of baking soda (sodium bicarbonate). Furthermore, we discuss the side effects of pharmaceuticals on acid-base balance as well as the influence of acid-base status on the pharmacokinetic properties of drugs. Our review considers all major organ systems as well as information relevant to several clinical specialties such as anesthesiology, infectious disease, oncology, dentistry, and surgery.


Assuntos
Equilíbrio Ácido-Base/fisiologia , Desequilíbrio Ácido-Base/metabolismo , Desequilíbrio Ácido-Base/terapia , Equilíbrio Ácido-Base/efeitos dos fármacos , Animais , COVID-19/metabolismo , COVID-19/terapia , Homeostase/efeitos dos fármacos , Homeostase/fisiologia , Humanos , Medicina Tradicional/métodos , Medicina Tradicional/tendências , Bicarbonato de Sódio/administração & dosagem , Bicarbonato de Sódio/metabolismo
5.
Dokl Biochem Biophys ; 495(1): 307-310, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33368041

RESUMO

A new form of open-angle glaucoma has been identified, in which calcification and silicification of the trabecular meshwork is a potentially significant component of outflow obstruction. It is noted that the mineralization of this area is promoted by various disturbances in the acid-base balance in the tissue. The role of melanosomal enzymes in the initiation of the formation of mineral calcium phosphate in trabecular tissue in open-angle glaucoma is considered.


Assuntos
Calcinose/patologia , Glaucoma de Ângulo Aberto/patologia , Malha Trabecular/patologia , Desequilíbrio Ácido-Base/metabolismo , Desequilíbrio Ácido-Base/patologia , Biomineralização , Calcinose/metabolismo , Glaucoma de Ângulo Aberto/metabolismo , Humanos , Melanossomas/metabolismo , Melanossomas/patologia , Microscopia Eletrônica de Varredura/métodos , Malha Trabecular/metabolismo
6.
Respir Med ; 154: 18-26, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31203096

RESUMO

RATIONALE: Alterations of acid-base metabolism are an important outcome predictor in acute exacerbations of COPD, whereas sufficient metabolic compensation and adequate renal function are associated with decreased mortality. In stable COPD there is, however, only limited information on the combined role of acid-base balance, blood gases, renal and respiratory function on exacerbation risk grading. METHODS: We used baseline data of the COPD cohort COSYCONET, applying linear and logistic regression analyses, the results of which were implemented into a comprehensive structural equation model. As most informative parameters it comprised the estimated glomerular filtration rate (eGFR), lung function defined via forced expiratory volume in 1 s (FEV1), intrathoracic gas volume (ITGV) and (diffusing capacity for carbon monoxide (DLCO), moreover arterial oxygen content (CaO2), partial pressure of oxygen (PaCO2), base exess (BE) and exacerbation risk according to GOLD criteria. All measures were adjusted for age, gender, body-mass index, the current smoking status and pack years. RESULTS: 1506 patients with stable COPD (GOLD grade 1-4; mean age 64.5 ±â€¯8.1 y; mean FEV1 54 ±â€¯18 %predicted, mean eGFR 82.3 ±â€¯16.9 mL/min/1.73 m2) were included. BE was linked to eGFR, lung function and PaCO2 and played a role as indirect predictor of exacerbation risk via these measures; moreover, eGFR was directly linked to exacerbation risk. These associations remained significant after taking into account medication (diuretics, oral and inhaled corticosteroids), whereby corticosteroids had effects on exacerbation risk and lung function, diuretics on eGFR, BE and lung function. CONCLUSION: Even in stable COPD acid-base metabolism plays a key integrative role in COPD risk assessment despite rather small deviations from normality. It partially mediates the effects of impairments in kidney function, which are also directly linked to exacerbation risk.


Assuntos
Desequilíbrio Ácido-Base/complicações , Doença Pulmonar Obstrutiva Crônica/sangue , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Desequilíbrio Ácido-Base/metabolismo , Idoso , Gasometria , Monóxido de Carbono/metabolismo , Estudos de Coortes , Comorbidade , Estudos Transversais , Progressão da Doença , Feminino , Volume Expiratório Forçado , Taxa de Filtração Glomerular/fisiologia , Humanos , Testes de Função Renal , Masculino , Pessoa de Meia-Idade , Pressão Parcial , Capacidade de Difusão Pulmonar/fisiologia , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Testes de Função Respiratória , Medição de Risco/métodos
7.
Am J Nurs ; 119(3): 52-56, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30801317

RESUMO

Arterial blood gas (ABG) analysis assesses the adequacy of ventilation, oxygenation, and the acid-base status of the body by measuring the levels of pH, oxygen, carbon dioxide, and bicarbonate in arterial blood. Interpretation of ABG results, which can play a major role in diagnosis and treatment of patients with pulmonary and other critical conditions, can sometimes be difficult. This article focuses on basic ABG analysis and interpretation, discusses the combinations of imbalances that may occur, and reviews the compensatory mechanisms that arise as a result.


Assuntos
Desequilíbrio Ácido-Base/diagnóstico , Desequilíbrio Ácido-Base/metabolismo , Gasometria , Dióxido de Carbono/sangue , Oxigênio/sangue , Humanos
8.
Braz. j. med. biol. res ; 52(1): e7974, 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-974268

RESUMO

Details about the acid-base changes in hemodialysis are scarce in the literature but are potentially relevant to adequate management of patients. We addressed the acid-base kinetics during hemodialysis and throughout the interdialytic period in a cross-sectional study of adults undergoing conventional hemodialysis. Samples for blood gas analysis were obtained from the arterial limb of the arteriovenous fistula before the first session of the week (HD1), immediately at the end of HD1, and on sequential collections at 15, 30, 45, 60, and 120 min post-HD1. Additional blood samples were collected after ∼20 h following the end of the first dialysis and immediately prior to the initiation of the second dialysis of the week. Thirty adult patients were analyzed (55±15 years, 50% men, 23% diabetic; dialysis vintage 69±53 months). Mean serum bicarbonate levels increased at the end of HD1 (22.3±2.7 mEq/L vs 17.5±2.3 mEq/L, P<0.001) and remained stable until 20 h after the end of the session. The mean values of pCO2 before HD1 were below reference and at 60 and 120 min post-HD1 were significantly lower than at the start (31.3±2.7 mmHg and 30.9±3.7 mmHg vs 34.3±4.1 mmHg, P=0.041 and P=0.010, respectively). The only point of collection in which mean values of pCO2 were above 35 mmHg was 20 h post-dialysis. Serum bicarbonate levels remained stable for at least 20 h after the dialysis sessions, a finding that may have therapeutic implications. During dialysis, the respiratory response for correction of metabolic acidosis (i.e., pCO2 elevation) was impaired.


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Equilíbrio Ácido-Base/fisiologia , Desequilíbrio Ácido-Base/sangue , Diálise Renal , Falência Renal Crônica/metabolismo , Fatores de Tempo , Desequilíbrio Ácido-Base/metabolismo , Gasometria , Estudos Transversais , Falência Renal Crônica/sangue , Falência Renal Crônica/terapia
9.
Braz. j. med. biol. res ; 49(2): e5007, 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-766980

RESUMO

Metabolic acidosis has profound effects on vascular tone. This study investigated the in vivo effects of acute metabolic acidosis (AMA) and chronic metabolic acidosis (CMA) on hemodynamic parameters and endothelial function. CMA was induced by ad libitum intake of 1% NH4Cl for 7 days, and AMA was induced by a 3-h infusion of 6 M NH4Cl (1 mL/kg, diluted 1:10). Phenylephrine (Phe) and acetylcholine (Ach) dose-response curves were performed by venous infusion with simultaneous venous and arterial blood pressure monitoring. Plasma nitrite/nitrate (NOx) was measured by chemiluminescence. The CMA group had a blood pH of 7.15±0.03, which was associated with reduced bicarbonate (13.8±0.98 mmol/L) and no change in the partial pressure of arterial carbon dioxide (PaCO2). The AMA group had a pH of 7.20±0.01, which was associated with decreases in bicarbonate (10.8±0.54 mmol/L) and PaCO2 (47.8±2.54 to 23.2±0.74 mmHg) and accompanied by hyperventilation. Phe or ACh infusion did not affect arterial or venous blood pressure in the CMA group. However, the ACh infusion decreased the arterial blood pressure (ΔBP: -28.0±2.35 mm Hg [AMA] to -4.5±2.89 mmHg [control]) in the AMA group. Plasma NOx was normal after CMA but increased after AMA (25.3±0.88 to 31.3±0.54 μM). These results indicate that AMA, but not CMA, potentiated the Ach-induced decrease in blood pressure and led to an increase in plasma NOx, reinforcing the effect of pH imbalance on vascular tone and blood pressure control.


Assuntos
Animais , Masculino , Coelhos , Acetilcolina/administração & dosagem , Acidose/fisiopatologia , Pressão Sanguínea/efeitos dos fármacos , Endotélio Vascular/fisiopatologia , Hipotensão/induzido quimicamente , Doença Aguda , Desequilíbrio Ácido-Base/metabolismo , Acidose/induzido quimicamente , Acidose/metabolismo , Determinação da Pressão Arterial , Bicarbonatos/sangue , Pressão Sanguínea/fisiologia , Doença Crônica , Dióxido de Carbono/análise , Endotélio Vascular/metabolismo , Hemodinâmica/fisiologia , Hiperventilação/metabolismo , Luminescência , Nitratos/sangue , Óxido Nítrico/metabolismo , Nitritos/sangue
10.
Adv Chronic Kidney Dis ; 22(4): 320-4, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26088077

RESUMO

Bladder augmentation and urinary diversion have become standard of care as surgical treatments for structural and functional disorders affecting the bladder, both in children and adults. With improved medical care, long-term survival of these patients is expected. Common medical problems that can occur such as metabolic side effects including acid-base imbalances and nutritional issues need to be anticipated and addressed. In addition, surgical problems caused by impaired urinary drainage, namely stones and urinary tract infections, and mechanical factors related to catheterizable channels and continence also may compound postoperative management. The risk of malignancy after bladder augmentation and substitution, and appropriate surveillance for this, remains to be clearly defined.


Assuntos
Intestinos/transplante , Procedimentos de Cirurgia Plástica/métodos , Complicações Pós-Operatórias/metabolismo , Bexiga Urinária/cirurgia , Derivação Urinária/métodos , Doenças Urológicas/cirurgia , Desequilíbrio Ácido-Base/metabolismo , Desmineralização Patológica Óssea/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Deficiência de Vitamina B 12/metabolismo , Desequilíbrio Hidroeletrolítico/metabolismo
11.
BMC Cancer ; 14: 734, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25269858

RESUMO

BACKGROUND: Cancer stem cells are hypoxia-resistant and present a preponderant glycolytic metabolism. These characteristics are also found in basal-like breast carcinomas (BLBC), which show increased expression of cancer stem cell markers.Recently, we demonstrated that P-cadherin, a biomarker of BLBC and a poor prognostic factor in this disease, mediates stem-like properties and resistance to radiation therapy. Thus, the aim of the present study was to evaluate if P-cadherin expression was associated to breast cancer cell populations with an adapted phenotype to hypoxia. METHODS: Immunohistochemistry was performed to address the expression of P-cadherin, hypoxic, glycolytic and acid-resistance biomarkers in primary human breast carcinomas. In vitro studies were performed using basal-like breast cancer cell lines. qRT-PCR, FACS analysis, western blotting and confocal microscopy were used to assess the expression of P-cadherin after HIF-1α stabilization, achieved by CoCl2 treatment. siRNA-mediated knockdown was used to silence the expression of several targets and qRT-PCR was employed to evaluate the effects of P-cadherin on HIF-1α signaling. P-cadherin high and low breast cancer cell populations were sorted by FACS and levels of GLUT1 and CAIX were assessed by FACS and western blotting. Mammosphere forming efficiency was used to determine the stem cell activity after specific siRNA-mediated knockdown, further confirmed by western blotting. RESULTS: We demonstrated that P-cadherin overexpression was significantly associated with the expression of HIF-1α, GLUT1, CAIX, MCT1 and CD147 in human breast carcinomas. In vitro, we showed that HIF-1α stabilization was accompanied by increased membrane expression of P-cadherin and that P-cadherin silencing led to a decrease of the mRNA levels of GLUT1 and CAIX. We also found that the cell fractions harboring high levels of P-cadherin were the same exhibiting more GLUT1 and CAIX expression. Finally, we showed that P-cadherin silencing significantly decreases the mammosphere forming efficiency in the same range as the silencing of HIF-1α, CAIX or GLUT1, validating that all these markers are being expressed by the same breast cancer stem cell population. CONCLUSIONS: Our results establish a link between aberrant P-cadherin expression and hypoxic, glycolytic and acid-resistant breast cancer cells, suggesting a possible role for this marker in cancer cell metabolism.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Caderinas/metabolismo , Carcinoma Ductal de Mama/metabolismo , Glicólise , Desequilíbrio Ácido-Base/metabolismo , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Anidrase Carbônica IX , Anidrases Carbônicas/genética , Anidrases Carbônicas/metabolismo , Linhagem Celular Tumoral , Feminino , Expressão Gênica , Transportador de Glucose Tipo 1/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Fenótipo , Esferoides Celulares/metabolismo , Análise Serial de Tecidos
12.
J Biol Chem ; 289(28): 19531-7, 2014 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-24898253

RESUMO

Transmembrane lipid transporters are believed to establish and maintain phospholipid asymmetry in biological membranes; however, little is known about the in vivo function of the specific transporters involved. Here, we report that developing erythrocytes from mice lacking the putative phosphatidylserine flippase ATP11C showed a lower rate of PS translocation in vitro compared with erythrocytes from wild-type littermates. Furthermore, the mutant mice had an elevated percentage of phosphatidylserine-exposing mature erythrocytes in the periphery. Although erythrocyte development in ATP11C-deficient mice was normal, the mature erythrocytes had an abnormal shape (stomatocytosis), and the life span of mature erythrocytes was shortened relative to that in control littermates, resulting in anemia in the mutant mice. Thus, our findings uncover an essential role for ATP11C in erythrocyte morphology and survival and provide a new candidate for the rare inherited blood disorder stomatocytosis with uncompensated anemia.


Assuntos
Adenosina Trifosfatases/metabolismo , Membrana Eritrocítica/enzimologia , Fosfolipídeos/metabolismo , Desequilíbrio Ácido-Base/genética , Desequilíbrio Ácido-Base/metabolismo , Desequilíbrio Ácido-Base/patologia , Adenosina Trifosfatases/genética , Anemia Hemolítica Congênita/genética , Anemia Hemolítica Congênita/metabolismo , Anemia Hemolítica Congênita/patologia , Animais , Transporte Biológico Ativo , Sobrevivência Celular/fisiologia , Membrana Eritrocítica/genética , Eritrócitos Anormais/metabolismo , Eritrócitos Anormais/patologia , Erros Inatos do Metabolismo/genética , Erros Inatos do Metabolismo/metabolismo , Erros Inatos do Metabolismo/patologia , Camundongos , Camundongos Mutantes , Fosfolipídeos/genética
13.
Am J Physiol Renal Physiol ; 305(12): F1747-64, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24133121

RESUMO

The renal proximal tubule (PT) is a major site for maintaining whole body pH homeostasis and is responsible for reabsorbing ∼80% of filtered HCO3(-), the major plasma buffer, into the blood. The PT adapts its rate of HCO3(-) reabsorption (JHCO3(-)) in response to acute acid-base disturbances. Our laboratory previously showed that single isolated perfused PTs adapt JHCO3(-) in response to isolated changes in basolateral (i.e., blood side) CO2 and HCO3(-) concentrations but, surprisingly, not to pH. The response to CO2 concentration can be blocked by the ErbB family tyrosine kinase inhibitor PD-168393. In the present study, we exposed enriched rabbit PT suspensions to five acute acid-base disturbances for 5 and 20 min using a panel of phosphotyrosine (pY)-specific antibodies to determine the influence of each disturbance on pan-pY, ErbB1-specific pY (four sites), and ErbB2-specific pY (two sites). We found that each acid-base treatment generated a distinct temporal pY pattern. For example, the summated responses of the individual ErbB1/2-pY sites to each disturbance showed that metabolic acidosis (normal CO2 concentration and reduced HCO3(-) concentration) produced a transient summated pY decrease (5 vs. 20 min), whereas metabolic alkalosis produced a transient increase. Respiratory acidosis (normal HCO3(-) concentration and elevated CO2 concentration) had little effect on summated pY at 5 min but produced an elevation at 20 min, whereas respiratory alkalosis produced a reduction at 20 min. Our data show that ErbB1 and ErbB2 in the PT respond to acute acid-base disturbances, consistent with the hypothesis that they are part of the signaling cascade.


Assuntos
Desequilíbrio Ácido-Base/metabolismo , Acidose/metabolismo , Alcalose/metabolismo , Receptores ErbB/metabolismo , Túbulos Renais Proximais/metabolismo , Receptor ErbB-2/metabolismo , Animais , Bicarbonatos/metabolismo , Dióxido de Carbono/metabolismo , Inibidores Enzimáticos/farmacologia , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/efeitos dos fármacos , Feminino , Concentração de Íons de Hidrogênio , Modelos Animais , Fosforilação , Coelhos , Receptor ErbB-2/antagonistas & inibidores , Receptor ErbB-2/efeitos dos fármacos , Transdução de Sinais/fisiologia , Fatores de Tempo
14.
Patol Fiziol Eksp Ter ; (3): 87-93, 2012.
Artigo em Russo | MEDLINE | ID: mdl-23072118

RESUMO

Endoplasmic reticulum stress - typical molecular pathophysiological process that underlies many cardiovascular, endocrine and other diseases. Violations of the protein conformational maturation processes in the endoplasmic reticulum can cause proteotoxic stress. Compensatory mechanisms are activated in response to ER stress include increased expression of enzymes involved in the formation of disulfide bonds in proteins. The sulfhydryl groups oxidation in the electron transport chain (PDI-ERO1-O2) is associated with reactive oxygen species (ROS) generation. Increased activity of oxidoreductase ERO1 could be one of the mechanisms of oxidative stress - however, a direct relationship of ER stress with the overproduction of ROS remains a subject of debate. In this study we have shown that induced by dithiothreitol (DTT) violation of the redox balance with low ROS production leads to the endoplasmic reticulum stress in Jurkat cells. ER-stress in these cells is not associated with increased ROS production, DTT treatment leads to induction of apoptosis. Modulation of intracellular levels of ROS can influence the apoptosis-inducing effects of ER-stress. Given the possible involvement of ROS in the generation of disulfide bonds, the role of ROS in ER stress may be a modulation of disulfide proteome including client proteins.


Assuntos
Desequilíbrio Ácido-Base/metabolismo , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/efeitos dos fármacos , Desequilíbrio Ácido-Base/induzido quimicamente , Apoptose/efeitos dos fármacos , Técnicas de Cultura de Células , Ditiotreitol/farmacologia , Relação Dose-Resposta a Droga , Retículo Endoplasmático/metabolismo , Citometria de Fluxo , Homocisteína/farmacologia , Humanos , Immunoblotting , Imuno-Histoquímica , Células Jurkat , Microscopia Confocal , Espécies Reativas de Oxigênio/metabolismo , Resposta a Proteínas não Dobradas/efeitos dos fármacos
15.
Pediatr Surg Int ; 27(7): 695-8, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21221604

RESUMO

PURPOSE: Hypertrophic pyloric stenosis (HPS) is a common condition of infancy, often presenting with marked biochemical derangement, requiring correction. Previous studies have looked at the relationship between serum electrolytes and acid-base balance in HPS but not at the relationship between the degree of biochemical derangement and time taken to resolve the biochemical abnormality. METHODS: Retrospective analysis was performed on all 151 infants undergoing pyloromyotomy over a 3 year period. Of these, 105 met the inclusion criteria of: compliance with the unit HPS fluid protocol, and the documentation of at least three serial biochemical investigations. The rate of correction for each biochemical marker (sodium, potassium, chloride, urea, pCO2, hydrogen ion concentration, bicarbonate and the base excess) was plotted against the degree of disturbance and then against time. RESULTS: A significant relationship (P < 0.01) was found between the rate of correction of an abnormal chloride, urea or base excess and the degree of initial derangement. This enables the prediction of the time taken for the required correction of biochemical abnormalities prior to theatre. CONCLUSION: This method of analysis may be of value in comparing the effectiveness of different fluid regimes in use for the correction of biochemical abnormalities in infants with IHPS.


Assuntos
Desequilíbrio Ácido-Base/metabolismo , Estenose Pilórica Hipertrófica/metabolismo , Piloro/fisiopatologia , Desequilíbrio Ácido-Base/etiologia , Desequilíbrio Ácido-Base/terapia , Cloretos/sangue , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Progressão da Doença , Feminino , Hidratação/métodos , Humanos , Concentração de Íons de Hidrogênio , Lactente , Recém-Nascido , Masculino , Potássio/sangue , Prognóstico , Estenose Pilórica Hipertrófica/complicações , Estenose Pilórica Hipertrófica/terapia , Piloro/cirurgia , Estudos Retrospectivos , Sódio/sangue
16.
Biol Reprod ; 82(5): 948-57, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20130267

RESUMO

Male mice deficient in ESR1 (ERalpha) (Esr1KO mice) are infertile, and sperm recovered from the cauda epididymis exhibit reduced motility and fail to fertilize eggs in vitro. These effects on sperm appear to result from defective epididymal function and not a direct effect on spermatogenesis, as Esr1KO germ cells transplanted into wild-type testes yield normal offspring. We hypothesized that the previously described defect in efferent duct fluid reabsorption would lead to alterations in the epididymal fluid milieu, which would negatively impact sperm function. Analysis of the epididymal fluid revealed that the Esr1KO maintains a higher luminal pH throughout the epididymis, confirming an inability of the efferent ducts and/or epididymis to properly acidify the luminal contents. Subsequent studies showed that these abnormalities were not the result of global defects in epididymal function since protein secretion by the Esr1KO epididymis appeared normal as judged by SDS-PAGE of total secreted proteins and by immunoblotting of candidate secreted proteins. To gain insight into the basis of the aberrant fluid homeostasis in the Esr1KO epididymis, the expression of several enzymes and transporters known to be involved in acid/base regulation were analyzed. The levels of SLC9A3 (NHE3) as well as carbonic anhydrase XIV and SLC4A4 (NBC1) were all reduced in the proximal portion of the Esr1KO epididymis, while other components appeared unaffected, including other ion transporters and ATP6V0A1 (V-ATPase). The altered luminal milieu of the Esr1KO epididymis was shown to lead to a corresponding increase in the intracellular pH of Esr1KO sperm, relative to sperm from control animals. Since pH and bicarbonate ions are critical regulators of sperm cAMP levels and motility, we attempted to bypass the abnormal luminal and intracellular environment by supplementing sperm with exogenous cAMP. This treatment rescued all defective motility parameters, as assayed by CASA, further showing that motility defects are not intrinsic to the sperm but, rather, result from the abnormal epididymal milieu.


Assuntos
Desequilíbrio Ácido-Base/metabolismo , Proteínas Secretadas pelo Epidídimo/metabolismo , Epididimo/metabolismo , Receptor alfa de Estrogênio/metabolismo , Motilidade dos Espermatozoides/fisiologia , Desequilíbrio Ácido-Base/genética , Animais , AMP Cíclico/metabolismo , Receptor alfa de Estrogênio/genética , Concentração de Íons de Hidrogênio , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Maturação do Esperma/fisiologia , Transporte Espermático/fisiologia , Espermatozoides/metabolismo
17.
Interact Cardiovasc Thorac Surg ; 7(6): 969-72, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18718953

RESUMO

Pediatric cardiopulmonary bypass (CPB) involves a high ratio of priming blood volume to patient blood volume. The composition of packed red blood cells (RBCs) is very unphysiological in terms of acid-base, electrolyte and metabolite values. Therefore, we tested the hypothesis whether ultrafiltration of the prime and replacement with bicarbonate buffered hemofiltration solution (BB-HS) is sufficient for reducing the metabolic load and reaching a physiologic state. For planned surgery of congenital heart defects with cardiopulmonary bypass, 20 CPB circuits were primed with BB-HS, gelatin and 1 unit of RBCs. The fluid was hemofiltrated using an ultrahemofilter at 300 ml/min until approximately 1000 ml of ultrafiltrate was restored with BB-HS. Blood gas analyses were obtained from the priming blood, once before and once after bicarbonate buffered ultrafiltration (BBUF). The measured substrates decreased significantly (P<0.001) after BBUF (glucose from 13.0+/-2.6 to 6.3+/-1.0 and lactate from 3.8+/-1.5 to 2.3+/-1.0 mmol/l). Acid-base parameters increased (P<0.001) to normal or high normal values (pH from 7.01+/-0.09 to 7.68+/-0.12; HCO(3) from 12.1+/-2.4 to 25.4+/-3.6 mmol/l and BE from -15.4+/-3.6 to -0.8+/-3.7 mmol/l). Even the electrolytes sodium, potassium and calcium changed significantly (P<0.001) toward the physiologic range. BBUF is an efficient method of reducing the metabolic load of priming. After BBUF, even the electrolyte and acid-base balance reached a physiologic state, which is important for minimizing electrolyte and acid-base disturbances after initiation of CPB.


Assuntos
Desequilíbrio Ácido-Base/prevenção & controle , Bicarbonatos/administração & dosagem , Procedimentos Cirúrgicos Cardíacos , Soluções Cardioplégicas/administração & dosagem , Ponte Cardiopulmonar , Cardiopatias Congênitas/cirurgia , Hemofiltração , Equilíbrio Ácido-Base/efeitos dos fármacos , Desequilíbrio Ácido-Base/etiologia , Desequilíbrio Ácido-Base/metabolismo , Soluções Tampão , Ponte Cardiopulmonar/efeitos adversos , Eletrólitos/sangue , Cardiopatias Congênitas/metabolismo , Humanos , Lactente , Recém-Nascido , Estudos Prospectivos , Resultado do Tratamento
18.
Acta Pharmacol Sin ; 28(11): 1731-6, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17959023

RESUMO

AIM: To investigate the underlying mechanism of acid-sensing ion channel (ASIC) 1a involved in the acidosis-induced cytotoxicity of rat C6 glioma cells. METHODS: The stable ASIC1a-silenced C6 cells built with the RNA interference technology were confirmed by RT-PCR and Western blot analysis. Intracellular calcium ([Ca2+]i) in both the wild-type rat C6 glioma cells and the ASIC1a-silenced C6 cells were analyzed before and after acid application/exposure with the calcium imaging experiment. RESULTS: The rapid extracellular pH drop induced the increase of [Ca2+]i in the wild-type C6 cells, but not in the ASIC1a-silenced C6 cells. During the prolonged acid exposure, [Ca2+]i was lower in the ASIC1a-silenced C6 cells than that in the control cells. CONCLUSION: The resultant toxicity of [Ca2+]i might contribute to the acidosis-induced cytotoxicity.


Assuntos
Desequilíbrio Ácido-Base/metabolismo , Glioma/metabolismo , Ácido Clorídrico/toxicidade , Proteínas do Tecido Nervoso/fisiologia , Canais de Sódio/fisiologia , Canais Iônicos Sensíveis a Ácido , Animais , Cálcio/metabolismo , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Ácido Clorídrico/administração & dosagem , Técnicas In Vitro , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Interferência de RNA , RNA Mensageiro/metabolismo , Ratos , Canais de Sódio/genética , Canais de Sódio/metabolismo
19.
Eur J Haematol ; 75(6): 449-60, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16313256

RESUMO

BACKGROUND AND AIM: A wide array of disturbances in electrolyte equilibrium is commonly seen in patients with acute leukemia (AL). These abnormalities present a potential hazard in these patients, as that of enhancing the cardiotoxic effects of certain chemotherapeutic regimens. The literature dealing with AL-related electrolyte abnormalities and their interactions in leukemic patients was reviewed. DATA SYNTHESIS: Sources included MEDLINE and EMBASE. The search strategy was based on the combination of 'acute leukemia', 'electrolyte abnormalities', 'acid-base disorders', 'potassium', 'sodium', 'magnesium', 'calcium', and 'phosphorus'. References of retrieved articles were also screened. A decrease in serum potassium, mainly owing to lysozyme-induced tubular damage, appears to be one of the most frequent and potentially hazardous abnormalities. Other clinically significant metabolic perturbations include hyponatremia and hypercalcemia. CONCLUSION: A broad spectrum of electrolyte abnormalities is encountered in the clinical setting of AL, which are related to the disease process per se and/or to the therapeutic interventions. Clinicians should be vigilant for early detection and appropriate management of these disorders before the initiation of chemotherapy regimens as well as during treatment.


Assuntos
Desequilíbrio Ácido-Base , Leucemia , Desequilíbrio Hidroeletrolítico , Desequilíbrio Ácido-Base/etiologia , Desequilíbrio Ácido-Base/metabolismo , Antineoplásicos/efeitos adversos , Antineoplásicos/metabolismo , Antineoplásicos/uso terapêutico , Cardiopatias/induzido quimicamente , Humanos , Leucemia/complicações , Leucemia/tratamento farmacológico , Leucemia/metabolismo , MEDLINE , Desequilíbrio Hidroeletrolítico/etiologia , Desequilíbrio Hidroeletrolítico/metabolismo
20.
Curr HIV/AIDS Rep ; 2(3): 109-15, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16091256

RESUMO

Renal electrolyte disorders, acute renal failure, and a variety of chronic renal diseases are common in HIV-infected patients. Glomerular disorders include IgA nephropathy, cryoglobulinemia, amyloidosis, and a lupus-like immune complex glomerulopathy. The most attention has been focused on collapsing glomerulopathy associated with nephrotic syndrome and progressive renal failure, which appears to be unique for patients with HIV/AIDS, called HIV-associated nephropathy (HIVAN), and it occurs predominantly in African American patients. Investigations in humans and in a transgenic mouse model reveal direct infection of renal epithelial cells by HIV and toxic cellular and immunologic processes mediated by HIV glycoproteins as the principal pathophysiology of HIVAN. Highly active antiretroviral treatment may be associated with an improved renal outcome and even reversal of kidney disease in some patients. Treatment with angiotensin-converting enzyme inhibitors may avert progression of HIVAN to end-stage kidney disease and result in superior patient and kidney survival as compared with untreated patients.


Assuntos
Nefropatia Associada a AIDS , Desequilíbrio Ácido-Base , Corticosteroides/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Nefropatia Associada a AIDS/tratamento farmacológico , Nefropatia Associada a AIDS/etiologia , Nefropatia Associada a AIDS/fisiopatologia , Desequilíbrio Ácido-Base/etiologia , Desequilíbrio Ácido-Base/metabolismo , Desequilíbrio Ácido-Base/fisiopatologia , Corticosteroides/efeitos adversos , Adulto , Animais , Humanos , Masculino
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