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1.
Am J Respir Cell Mol Biol ; 61(4): 512-524, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30951642

RESUMO

Inflammation and vascular smooth muscle cell (VSMC) phenotypic switching are causally linked to pulmonary arterial hypertension (PAH) pathogenesis. Carbonic anhydrase inhibition induces mild metabolic acidosis and exerts protective effects in hypoxic pulmonary hypertension. Carbonic anhydrases and metabolic acidosis are further known to modulate immune cell activation. To evaluate if carbonic anhydrase inhibition modulates macrophage activation, inflammation, and VSMC phenotypic switching in severe experimental pulmonary hypertension, pulmonary hypertension was assessed in Sugen 5416/hypoxia (SU/Hx) rats after treatment with acetazolamide or ammonium chloride (NH4Cl). We evaluated pulmonary and systemic inflammation and characterized the effect of carbonic anhydrase inhibition and metabolic acidosis in alveolar macrophages and bone marrow-derived macrophages (BMDMs). We further evaluated the treatment effects on VSMC phenotypic switching in pulmonary arteries and pulmonary artery smooth muscle cells (PASMCs) and corroborated some of our findings in lungs and pulmonary arteries of patients with PAH. Both patients with idiopathic PAH and SU/Hx rats had increased expression of lung inflammatory markers and signs of PASMC dedifferentiation in pulmonary arteries. Acetazolamide and NH4Cl ameliorated SU/Hx-induced pulmonary hypertension and blunted pulmonary and systemic inflammation. Expression of carbonic anhydrase isoform 2 was increased in alveolar macrophages from SU/Hx animals, classically (M1) and alternatively (M2) activated BMDMs, and lungs of patients with PAH. Carbonic anhydrase inhibition and acidosis had distinct effects on M1 and M2 markers in BMDMs. Inflammatory cytokines drove PASMC dedifferentiation, and this was inhibited by acetazolamide and acidosis. The protective antiinflammatory effect of acetazolamide in pulmonary hypertension is mediated by a dual mechanism of macrophage carbonic anhydrase inhibition and systemic metabolic acidosis.


Assuntos
Acetazolamida/uso terapêutico , Cloreto de Amônio/uso terapêutico , Inibidores da Anidrase Carbônica/uso terapêutico , Anidrases Carbônicas/fisiologia , Hipertensão Pulmonar/tratamento farmacológico , Acidose/induzido quimicamente , Acidose/complicações , Acidose/imunologia , Animais , Diferenciação Celular/efeitos dos fármacos , Proteínas Contráteis/biossíntese , Proteínas Contráteis/genética , Avaliação Pré-Clínica de Medicamentos , Humanos , Hipertensão Pulmonar/enzimologia , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/patologia , Hipóxia/complicações , Inflamação , Macrófagos/efeitos dos fármacos , Macrófagos/enzimologia , Macrófagos Alveolares/efeitos dos fármacos , Macrófagos Alveolares/enzimologia , Masculino , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/enzimologia , Isoformas de Proteínas/antagonistas & inibidores , Artéria Pulmonar/patologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Ratos , Ratos Sprague-Dawley
2.
J Pain ; 18(5): 526-534, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28062311

RESUMO

Acidosis occurs in a variety of pathophysiological and painful conditions where it is thought to excite or contribute to excitation of nociceptive neurons. Despite potential clinical relevance the principal receptor for sensing acidosis is unclear, but several receptors have been proposed. We investigated the contribution of the acid-sensing ion channels, transient receptor potential vanilloid type 1 (TRPV1) and transient receptor potential ankyrin type 1 (TRPA1) to peripheral pain signaling. We first established a human pain model using intraepidermal injection of the TRPA1 agonist carvacrol. This resulted in concentration-dependent pain sensations, which were reduced by experimental TRPA1 antagonist A-967079. Capsaicin-induced pain was reduced by the TRPV1 inhibitor BCTC. Amiloride was used to block acid-sensing ion channels. Testing these antagonists in a double-blind and randomized experiment, we probed the contribution of the respective channels to experimental acidosis-induced pain in 15 healthy human subjects. A continuous intraepidermal injection of pH 4.3 was used to counter the buffering capacity of tissue and generate a prolonged painful stimulation. In this model, addition of A-967079, BCTC or amiloride did not reduce the reported pain. In conclusion, target-validated antagonists, applied locally in human skin, have excluded the main hypothesized targets and the mechanism of the human acidosis-induced pain remains unclear. PERSPECTIVE: An acidic milieu is a trigger of pain in many clinical conditions. The aim of this study was to identify the contribution of the currently hypothesized sensors of acid-induced pain in humans. Surprisingly, inhibition of these receptors did not alter acidosis-induced pain.


Assuntos
Acidose/complicações , Analgésicos/uso terapêutico , Dor/tratamento farmacológico , Dor/etiologia , Canal de Cátion TRPA1/antagonistas & inibidores , Canais de Cátion TRPV/antagonistas & inibidores , Bloqueadores do Canal Iônico Sensível a Ácido/uso terapêutico , Adulto , Amilorida/uso terapêutico , Análise de Variância , Capsaicina/efeitos adversos , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oximas/uso terapêutico , Medição da Dor , Pirazinas/uso terapêutico , Piridinas/uso terapêutico
3.
Neuropediatrics ; 48(2): 108-110, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27875839

RESUMO

Leukoencephalopathy with thalamus and brainstem involvement and high lactate (LTBL) is a recently described autosomal recessive mitochondrial disease characterized by early onset of neurological symptoms, a biphasic clinical course, and distinctive neuroimaging. Pathogenic variants in the EARS2 gene that encode for mitochondrial glutamyl-tRNA synthetase are responsible for LTBL. Here, we describe the clinical course of an infant diagnosed with an acute crisis of LTBL and severe liver disease. This article illustrates the utility of blood lactate quantification in addition to basic metabolic testing and brain imaging in a child with low tone and poor growth. In addition, this case demonstrates the utility of current genetic diagnostic testing, in lieu of more invasive procedures, in obtaining rapid answers in this very complicated group of disorders.


Assuntos
Acidose/diagnóstico , Tronco Encefálico/diagnóstico por imagem , Ácido Láctico/sangue , Leucoencefalopatias/diagnóstico , Doenças Mitocondriais/diagnóstico , Tálamo/diagnóstico por imagem , Acidose/complicações , Acidose/terapia , Diagnóstico Diferencial , Glutamato-tRNA Ligase/genética , Humanos , Lactente , Leucoencefalopatias/complicações , Leucoencefalopatias/terapia , Hepatopatias/sangue , Hepatopatias/complicações , Hepatopatias/diagnóstico por imagem , Hepatopatias/terapia , Masculino , Doenças Mitocondriais/complicações , Doenças Mitocondriais/terapia
4.
Blood Purif ; 39(1-3): 84-92, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25662331

RESUMO

BACKGROUND: Despite recent advances in chronic kidney disease (CKD) and end-stage renal disease (ESRD) management, morbidity and mortality in this population remain exceptionally high. Persistent, low-grade inflammation has been recognized as an important component of CKD, playing a unique role in its pathophysiology and being accountable in part for cardiovascular and all-cause mortality, as well as contributing to the development of protein-energy wasting. SUMMARY: The variety of factors contribute to chronic inflammatory status in CKD, including increased production and decreased clearance of pro-inflammatory cytokines, oxidative stress and acidosis, chronic and recurrent infections, including those related to dialysis access, altered metabolism of adipose tissue, and intestinal dysbiosis. Inflammation directly correlates with the glomerular filtration rate (GFR) in CKD and culminates in dialysis patients, where extracorporeal factors, such as impurities in dialysis water, microbiological quality of the dialysate, and bioincompatible factors in the dialysis circuit play an additional role. Genetic and epigenetic influences contributing to inflammatory activation in CKD are currently being intensively investigated. A number of interventions have been proposed to target inflammation in CKD, including lifestyle modifications, pharmacological agents, and optimization of dialysis. Importantly, some of these therapies have been recently tested in randomized controlled trials. KEY MESSAGES: Chronic inflammation should be regarded as a common comorbid condition in CKD and especially in dialysis patients. A number of interventions have been proven to be safe and effective in well-designed clinical studies. This includes such inexpensive approaches as modification of physical activity and dietary supplementation. Further investigations are needed to evaluate the effects of these interventions on hard outcomes, as well as to better understand the role of inflammation in selected CKD populations (e.g., in children).


Assuntos
Acidose/terapia , Doenças Cardiovasculares/terapia , Falência Renal Crônica/terapia , Diálise Renal , Síndrome de Emaciação/terapia , Acidose/complicações , Acidose/mortalidade , Acidose/patologia , Anti-Inflamatórios/uso terapêutico , Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/patologia , Citocinas/biossíntese , Suplementos Nutricionais , Exercício Físico , Taxa de Filtração Glomerular , Humanos , Inflamação/complicações , Inflamação/mortalidade , Inflamação/patologia , Inflamação/terapia , Falência Renal Crônica/complicações , Falência Renal Crônica/mortalidade , Falência Renal Crônica/patologia , Estresse Oxidativo , Ensaios Clínicos Controlados Aleatórios como Assunto , Análise de Sobrevida , Síndrome de Emaciação/complicações , Síndrome de Emaciação/mortalidade , Síndrome de Emaciação/patologia
5.
Fetal Pediatr Pathol ; 34(1): 18-20, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25166299

RESUMO

Glutathione synthetase deficiency (GSSD) is a rare disorder of glutathione metabolism with varying clinical severity. Patients may present with hemolytic anemia alone or together with acidosis and central nervous system impairment. Diagnosis is made by clinical presentation and detection of elevated concentrations of 5-oxoproline in urine and low glutathione synthetase activity in erythrocytes or cultured skin fibroblasts. The prognosis seems to depend on early diagnosis and treatment. We report a 4 months old Tunisian male infant who presented with severe metabolic acidosis with high anion gap and hemolytic anemia. High level of 5-oxoproline was detected in her urine and diagnosis of GSSD was made. Treatment consists of the correction of acidosis, blood transfusion, and supplementation with antioxidants. He died of severe metabolic acidosis and sepsis at the age of 15 months.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/diagnóstico , Anemia Hemolítica/diagnóstico , Glutationa Sintase/deficiência , Glutationa Sintase/urina , Ácido Pirrolidonocarboxílico/urina , Acidose/complicações , Erros Inatos do Metabolismo dos Aminoácidos/complicações , Anemia Hemolítica/complicações , Antioxidantes/química , Eritrócitos/enzimologia , Evolução Fatal , Febre/complicações , Fibroblastos/enzimologia , Humanos , Lactente , Infecções por Klebsiella/complicações , Masculino , Sepse/complicações , Pele/citologia , Resultado do Tratamento , Tunísia
6.
Minerva Anestesiol ; 81(1): 65-75, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24608516

RESUMO

Acidosis, hypothermia and hypocalcaemia are determinants for morbidity and mortality during massive hemorrhages. However, precise pathological mechanisms of these environmental factors and their potential additive or synergistic anticoagulant and/or antiplatelet effects are not fully elucidated and are at least in part controversial. Best available evidences from experimental trials indicate that acidosis and hypothermia progressively impair platelet aggregability and clot formation. Considering the cell-based model of coagulation physiology, hypothermia predominantly prolongs the initiation phase, while acidosis prolongs the propagation phase of thrombin generation. Acidosis increases fibrinogen breakdown while hypothermia impairs its synthesis. Acidosis and hypothermia have additive effects. The effect of hypocalcaemia on coagulopathy is less investigated but it appears that below the cut-off of 0.9 mmol/L, several enzymatic steps in the plasmatic coagulation system are blocked while above that cut-off effects remain without clinical sequalae. The impact of environmental factor on hemostasis is underestimated in clinical practice due to our current practice of using routine coagulation laboratory tests such as partial thromboplastin time or prothrombin time, which are performed at standardized test temperature, after pH correction, and upon recalcification. Temperature-adjustments are feasible in viscoelastic point-of-care tests such as thrombelastography and thromboelastometry which may permit quantification of hypothermia-induced coagulopathy. Rewarming hypothermic bleeding patients is highly recommended because it improves patient outcome. Despite the absence of high-quality evidence, calcium supplementation is clinical routine in bleeding management. Buffer administration may not reverse acidosis-induced coagulopathy but may be essential for the efficacy of coagulation factor concentrates such as recombinant activated factor VII.


Assuntos
Acidose/complicações , Acidose/terapia , Transtornos da Coagulação Sanguínea/etiologia , Hemorragia/complicações , Hemorragia/terapia , Hipocalcemia/complicações , Hipocalcemia/terapia , Hipotermia/complicações , Hipotermia/terapia , Humanos
7.
J Ren Nutr ; 23(6): 399-405, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24070587

RESUMO

Vegetarian diet is a very old practice that is liable to confer some health benefits. Recent studies have demonstrated that modification of the dietary pattern with a reduction of animal protein intake and increased consumption of plant-based foods could influence cardiovascular risk profile and mortality rate. Moreover, phosphate bioavailability from plant proteins is reduced. These statements could lead to some benefits for chronic kidney disease (CKD) patients. This review summarizes the characteristics and benefits of vegetarian diets in the general population and the potential beneficial effects of such a diet on phosphate balance, insulin sensitivity, and the control of metabolic acidosis in CKD patients. Potential drawbacks exist when a vegetarian diet is associated with protein intake that is too restrictive and/or insufficient energy intake, justifying an early and regular nutritional follow-up jointly assumed by a nephrologist and a renal dietitian.


Assuntos
Dieta Vegetariana/efeitos adversos , Insuficiência Renal Crônica , Acidose/complicações , Acidose/prevenção & controle , Animais , Doenças Cardiovasculares/prevenção & controle , Dieta , Proteínas Alimentares/administração & dosagem , Ingestão de Energia , Humanos , Hiperfosfatemia/complicações , Hiperfosfatemia/prevenção & controle , Resistência à Insulina , Terapia Nutricional , Fenômenos Fisiológicos da Nutrição , Fosfatos/administração & dosagem , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/dietoterapia , Fatores de Risco
8.
Proc Nutr Soc ; 71(4): 566-75, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22429879

RESUMO

Nutritional interventions that might influence sarcopenia, as indicated by literature reporting on sarcopenia per se as well as dynapenia and frailty, are reviewed in relation to potential physiological aetiological factors, i.e. inactivity, anabolic resistance, inflammation, acidosis and vitamin D deficiency. As sarcopenia occurs in physically active and presumably well-nourished populations, it is argued that a simple nutritional aetiology is unlikely and unequivocal evidence for any nutritional influence is extremely limited. Dietary protein is probably the most widely researched nutrient but only for frailty is there one study showing evidence of an aetiological influence and most intervention studies with protein or amino acids have proved ineffective with only a very few exceptions. Fish oil has been shown to attenuate anabolic resistance of muscle protein synthesis in one study. There is limited evidence for a protective influence of antioxidants and inducers of phase 2 proteins on sarcopenia, dynapenia and anabolic resistance in human and animal studies. Also fruit and vegetables may protect against acidosis-induced sarcopenia through their provision of dietary potassium. While severe vitamin D deficiency is associated with dynapenia and sarcopenia, the evidence for a beneficial influence of increasing vitamin D status above the severe deficiency level is limited and controversial, especially in men. On this basis there is insufficient evidence for any more specific nutritional advice than that contained in the general healthy lifestyle-healthy diet message: i.e. avoiding inactivity and low intakes of food energy and nutrients and maintain an active lifestyle with a diet providing a rich supply of fruit and vegetables and frequent oily fish.


Assuntos
Antioxidantes/uso terapêutico , Dieta , Proteínas Alimentares/uso terapêutico , Óleos de Peixe/uso terapêutico , Estado Nutricional , Sarcopenia/prevenção & controle , Vitamina D/uso terapêutico , Acidose/complicações , Acidose/prevenção & controle , Animais , Humanos , Masculino , Proteínas Musculares/biossíntese , Sarcopenia/etiologia
9.
J Ren Nutr ; 22(2 Suppl): S1-21, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22365371

RESUMO

Chronic kidney disease (CKD) is increasingly common, and there is an increasing awareness that every strategy should be used to avoid complications of CKD. Restriction of dietary protein intake has been a relevant part of the management of CKD for more than 100 years, but even today, the principal goal of protein-restricted regimens is to decrease the accumulation of nitrogen waste products, hydrogen ions, phosphates, and inorganic ions while maintaining an adequate nutritional status to avoid secondary problems such as metabolic acidosis, bone disease, and insulin resistance, as well as proteinuria and deterioration of renal function. This supplement focuses on recent experimental and clinical findings related to an optimized dietary management of predialysis, dialysis, and transplanted patients as an important aspect of patient care. Nutritional treatment strategies are linked toward ameliorating metabolic and endocrine disturbances, improving/maintaining nutritional status, as well as delaying the renal replacement initiation and improving outcomes in CKD patients. A final consensus states that dietary manipulations should be considered as one of the main approaches in the management program of CKD patients and that a reasonable number of patients with moderate or severe CKD benefit from dietary protein/phosphorus restriction.


Assuntos
Aminoácidos/uso terapêutico , Dieta com Restrição de Proteínas/métodos , Cetoácidos/uso terapêutico , Falência Renal Crônica/dietoterapia , Acidose/complicações , Acidose/dietoterapia , Acidose/metabolismo , Aminoácidos/metabolismo , Animais , Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/dietoterapia , Doenças Cardiovasculares/metabolismo , Suplementos Nutricionais , Humanos , Resistência à Insulina , Cetoácidos/metabolismo , Falência Renal Crônica/complicações , Falência Renal Crônica/metabolismo , Desnutrição/complicações , Desnutrição/dietoterapia , Desnutrição/metabolismo , Camundongos , Estado Nutricional , Estresse Oxidativo , Proteinúria/complicações , Proteinúria/dietoterapia , Proteinúria/metabolismo , Ratos , Terapia de Substituição Renal , Resultado do Tratamento
10.
Indian J Pediatr ; 77(11): 1322-5, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20886316

RESUMO

Airway pressure release ventilation (APRV) is a relatively new mode of mechanical ventilation. The use of this model of ventilation in pediatrics has been limited. The authors describe their experience with this mode of ventilation in a series of pediatric hypoxemic respiratory failure patients. Three patients with acute hypoxemic respiratory failure (AHRF) were treated with APRV, when oxygenation did not improve with pressure control ventilation (PCV). The mean age of the patients was 5.8 ± 1.3 months. Fractional oxygen concentration decreased from 0.97 ± 0.02 for PCV to 0.68 ± 0.12 for APRV, peak airway pressure fell from 36.6 ± 11.5 cm H2O for PCV to 33.3 ± 5.7 cm H2O for APRV, mean airway pressure increased from 17.9 ± 5.9 cmH2O for PCV to 27 ± 2.6 cm H2O for APRV and release tidal volume increased from 8.3 ± 1.5 mL/kg for PCV to 13.2 ± 1.1 mL/kg for APRV after 1 h. APRV may improve oxygenation in pediatric AHRF when conventional mechanical ventilation fails. The APRV modality may provide better oxygenation with lower peak airway pressure.


Assuntos
Pressão Positiva Contínua nas Vias Aéreas , Hipóxia/terapia , Insuficiência Respiratória/terapia , Acidose/complicações , Acidose/terapia , Bacteriemia/complicações , Bacteriemia/terapia , Infecção Hospitalar/complicações , Infecção Hospitalar/terapia , Feminino , Humanos , Hipóxia/etiologia , Lactente , Masculino , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/terapia , Insuficiência Respiratória/etiologia , Convulsões/complicações , Convulsões/terapia , Sepse/complicações , Sepse/terapia
11.
Proc Nutr Soc ; 69(1): 166-73, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19954569

RESUMO

There is growing evidence that consumption of a Western diet is a risk factor for osteoporosis through excess acid supply, while fruits and vegetables balance the excess acidity, mostly by providing K-rich bicarbonate-rich foods. Western diets consumed by adults generate approximately 50-100 mEq acid/d; therefore, healthy adults consuming such a diet are at risk of chronic low-grade metabolic acidosis, which worsens with age as a result of declining kidney function. Bone buffers the excess acid by delivering cations and it is considered that with time an overstimulation of this process will lead to the dissolution of the bone mineral content and hence to reduced bone mass. Intakes of K, Mg and fruit and vegetables have been associated with a higher alkaline status and a subsequent beneficial effect on bone health. In healthy male volunteers an acid-forming diet increases urinary Ca excretion by 74% and urinary C-terminal telopeptide of type I collagen (C-telopeptide) excretion by 19% when compared with an alkali (base-forming) diet. Cross-sectional studies have shown that there is a correlation between the nutritional acid load and bone health measured by bone ultrasound or dual-energy X-ray absorptiometry. Few studies have been undertaken in very elderly women (>75 years), whose osteoporosis risk is very pertinent. The EVAluation of Nutrients Intakes and Bone Ultra Sound Study has developed and validated (n 51) an FFQ for use in a very elderly Swiss population (mean age 80.4 (sd 2.99) years), which has shown intakes of key nutrients (energy, fat, carbohydrate, Ca, Mg, vitamin C, D and E) to be low in 401 subjects. A subsequent study to assess net endogenous acid production (NEAP) and bone ultrasound results in 256 women aged > or = 75 years has shown that lower NEAP (P=0.023) and higher K intake (P=0.033) are correlated with higher bone ultrasound results. High acid load may be an important additional risk factor that may be particularly relevant in very elderly patients with an already-high fracture risk. The latter study adds to knowledge by confirming a positive link between dietary alkalinity and bone health indices in the very elderly. In a further study to complement these findings it has also been shown in a group of thirty young women that in Ca sufficiency an acid Ca-rich water has no effect on bone resorption, while an alkaline bicarbonate-rich water leads to a decrease in both serum parathyroid hormone and serum C-telopeptide. Further investigations need to be undertaken to study whether these positive effects on bone loss are maintained over long-term treatment. Mineral-water consumption could be an easy and inexpensive way of helping to prevent osteoporosis and could be of major interest for long-term prevention of bone loss.


Assuntos
Acidose/complicações , Densidade Óssea , Osso e Ossos/metabolismo , Dieta , Águas Minerais/uso terapêutico , Osteoporose/etiologia , Equilíbrio Ácido-Base/fisiologia , Acidose/dietoterapia , Acidose/metabolismo , Adulto , Idoso , Bicarbonatos/uso terapêutico , Reabsorção Óssea , Osso e Ossos/diagnóstico por imagem , Cálcio/administração & dosagem , Cálcio/urina , Colágeno Tipo I/metabolismo , Inquéritos sobre Dietas , Feminino , Fraturas Ósseas/etiologia , Humanos , Masculino , Osteoporose/metabolismo , Hormônio Paratireóideo/sangue , Peptídeos/metabolismo , Potássio na Dieta/administração & dosagem , Fatores de Risco , Inquéritos e Questionários , Suíça , Ultrassonografia , Adulto Jovem
12.
Exp Clin Endocrinol Diabetes ; 118(2): 105-12, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19449283

RESUMO

BACKGROUND: Chronic metabolic acidosis (CMA) is known to induce renal phosphate wasting and hypophosphatemia by enhancing bone resorption and inhibiting renal phosphate reabsorption. However, nothing is known regarding changes in the plasma levels of phosphate-regulating hormones during CMA, especially in humans with normal kidney function. METHODS: Fifteen healthy Thai female volunteers were given NH (4)Cl orally for 7 days to induce CMA with or without oral phosphate supplementation. Blood and 24-h urine specimens were collected prior to and after CMA induction. Plasma concentrations and fractional excretion of calcium and inorganic phosphate as well as plasma levels of fibroblast growth factor (FGF) 23, 25(OH)D (3), 1,25(OH) (2)D (3) and intact parathyroid hormone (iPTH) were determined. RESULTS: CMA led to hypophosphatemia and hypocalcemia with increases in the fractional excretion of calcium and phosphate. Plasma concentrations of FGF23, 25(OH)D (3) and iPTH were decreased, whereas that of 1,25(OH) (2)D (3) was increased. After oral phosphate supplementation, CMA-induced changes in the concentrations of the studied ions, FGF23 and 25(OH)D (3), but not those of 1,25(OH) (2)D (3) and iPTH, were diminished. CONCLUSIONS: The CMA-induced hypophosphatemia was likely to initiate a negative feedback response, thereby leading to reduction in the plasma levels of hyperphosphaturic hormones, FGF23 and PTH. An increase in the plasma 1,25(OH) (2)D (3) level, despite diminishing 25(OH)D (3) storage pool, may help enhance the intestinal phosphate absorption. Oral phosphate supplementation abolished the effects of CMA on FGF23 and 25(OH)D (3) levels, suggesting that the plasma phosphate concentration is the primary regulator of the plasma levels of these hormones during CMA.


Assuntos
Acidose/induzido quimicamente , Acidose/tratamento farmacológico , Calcifediol/sangue , Fatores de Crescimento de Fibroblastos/sangue , Hipofosfatemia/tratamento farmacológico , Fosfatos/uso terapêutico , Acidose/complicações , Administração Oral , Adulto , Cloreto de Amônio , Doença Crônica , Feminino , Fator de Crescimento de Fibroblastos 23 , Humanos , Hipofosfatemia/induzido quimicamente , Hipofosfatemia/etiologia , Pessoa de Meia-Idade , Estatísticas não Paramétricas
13.
Fiziol Zh (1994) ; 55(3): 118-24, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19526864

RESUMO

This study was conducted to evaluate acid-base status and fructose diphosphatase (FDPase) activity in 40 (4 groups of 10) male Wistar rats. One group of rats was left untreated as control, fed a standard diet, and given distilled water. Periodontitis model induced with 5 mg/kg NH4Cl (group 1), exposed to sodium fluoride (NaF) at the concentration 5 mg/l (group 2), exposed to NaF (5 mg/l) and supplemented with minerals and vitamins (group 3). At the termination of experimental period (30 days) the pH and pCO2 value of arterial blood were analysed. Then, the FDPase activity in the hemogenized heart, kidney liver, mandible, pelvis, and teeth were determined by measuring inorganic phosphate that converts from fructose-1.6-diphosphate and using spectrophotometer at 350 nm. The differences in the acid-base status and FDPase activity in the groups 1 and 2 were statistically significant in comparison with the control and group 3 (P < 0.001). Increased FDPase activities are associated with acid-base status. The minerals and vitamins supplementation proved to restore acid-base balance, reduce toxicity and establish steady enzyme activity, which has not been previously reported.


Assuntos
Equilíbrio Ácido-Base , Acidose/enzimologia , Frutose-Bifosfatase/metabolismo , Periodontite/enzimologia , Fluoreto de Sódio/toxicidade , Equilíbrio Ácido-Base/efeitos dos fármacos , Acidose/sangue , Acidose/complicações , Animais , Dióxido de Carbono/sangue , Modelos Animais de Doenças , Concentração de Íons de Hidrogênio , Masculino , Minerais/farmacologia , Especificidade de Órgãos , Periodontite/sangue , Periodontite/induzido quimicamente , Periodontite/complicações , Ratos , Ratos Wistar , Vitaminas/farmacologia
15.
J Appl Physiol (1985) ; 102(4): 1357-66, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17138840

RESUMO

The preoptic-anterior hypothalamus (POAH) controls body temperature, and thermoregulatory responses are impaired during hypercapnia. If increased CO(2) or its accompanying acidosis inhibits warm-sensitive POAH neurons, this could provide an explanation for thermoregulatory impairment during hypercapnia. To test this possibility, extracellular electrophysiological recordings determined the effects of CO(2) and pH on the firing rates of both temperature-sensitive and -insensitive neurons in hypothalamic tissue slices from 89 male Sprague-Dawley rats. Firing rate activity was recorded in 121 hypothalamic neurons before, during, and after changing the CO(2) concentration aerating the tissue slice chamber or changing the pH of the solution bathing the tissue slices. Increasing the aeration CO(2) concentration from 5% (control) to 10% (hypercapnic) had no effect on most (i.e., 69%) POAH temperature-insensitive neurons; however, this hypercapnia inhibited the majority (i.e., 59%) of warm-sensitive neurons. CO(2) affected similar proportions of (non-POAH) neurons in other hypothalamic regions. These CO(2) effects appear to be due to changes in pH since the CO(2)-affected neurons responded similarly to isocapnic acidosis (i.e., normal CO(2) and decreased pH) but were not responsive to isohydric hypercapnia (i.e., increased CO(2) and normal pH). These findings may offer a neural explanation for some heat-related illnesses (e.g., exertional heat stroke) where impaired heat loss is associated with acidosis.


Assuntos
Acidose/fisiopatologia , Regulação da Temperatura Corporal , Dióxido de Carbono/metabolismo , Golpe de Calor/fisiopatologia , Hipercapnia/fisiopatologia , Hipotálamo/fisiopatologia , Neurônios Aferentes/metabolismo , Acidose/complicações , Animais , Células Cultivadas , Golpe de Calor/etiologia , Temperatura Alta , Concentração de Íons de Hidrogênio , Hipercapnia/complicações , Masculino , Inibição Neural , Ratos , Ratos Sprague-Dawley
16.
Minerva Anestesiol ; 71(5): 237-42, 2005 May.
Artigo em Inglês, Italiano | MEDLINE | ID: mdl-15834352

RESUMO

The aim of the paper was to describe an unusual case of non lactic metabolic acidosis connected to hypophosphatemia and refractory to infusion of bicarbonate. A 37 year old man was admitted to Intensive Care Unit with a severe metabolic acidosis. On admission the arterial gas analysis showed non lactic metabolic acidosis (pH 7.17; base excess [BE] -20.3; lactic acid 0.8 mMol/L), with hypoxemia and critical hypocapnia. Despite therapy with bicarbonate the acidosis persisted. After 4 hours glucose phosphate was administered, although the phosphoremia was unknown. After phosphate supplementation an improvement of acidosis was observed. Our hypothesis is that in the kidney phosphate depletion caused impaired tubular reabsorption of bicarbonate, which led to a non lactic metabolic acidosis.


Assuntos
Acidose/complicações , Hipofosfatemia/complicações , Acidose/tratamento farmacológico , Adulto , Bicarbonatos/uso terapêutico , Gasometria , Soluções Tampão , Cuidados Críticos , Humanos , Hipofosfatemia/tratamento farmacológico , Ácido Láctico/sangue , Masculino , Fosfatos/uso terapêutico
17.
Kidney Int ; 58(2): 748-52, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10916098

RESUMO

BACKGROUND: The chronic low-grade metabolic acidosis that occurs in various renal disorders and in normal people, and that is related both to dietary net acid load and age-related renal functional decline, may contribute to osteoporosis by increasing urine calcium excretion. Administration of potassium (K) alkali salts neutralizes acid and lowers urine calcium excretion. Urine calcium excretion also can be reduced by the administration of thiazide diuretics, which are often given with supplemental K to avoid hypokalemia. We determined whether the K alkali salt potassium bicarbonate (KHCO3) and the thiazide diuretic hydrochlorothiazide (HCTZ) combined is more effective in reducing urinary calcium than KHCO3 alone or HCTZ combined with the conventionally coadministered nonalkalinizing K salt potassium chloride (KCl). METHODS: Thirty-one healthy men and women aged 50 or greater were recruited for a four-week, double-blind, randomized study. After a baseline period of 10 days with three 24-hour urine and arterialized blood collections, subjects were randomized to receive either HCTZ (50 mg) plus potassium (60 mmol daily) as either the chloride or bicarbonate salt. Another 19 women received potassium bicarbonate (60 mmol) alone. After two weeks, triplicate collections of 24-hour urines and arterialized bloods were repeated. RESULTS: Urinary calcium excretion decreased significantly in all groups. KHCO3 alone and HCTZ + KCl induced similar decreases (-0.70 +/- 0.60 vs. -0.80 +/- 1. 0 mmol/day, respectively). Compared with those treatments, the combination of HCTZ + KHCO3 induced more than a twofold greater decrease in urinary calcium excretion (-1.8 +/- 1.2 mmol/day, P < 0. 05). Both HCTZ + KHCO3 and KHCO3 alone reduced net acid excretion significantly (P < 0.05) to values of less than zero. CONCLUSIONS: KHCO3 was superior to KCl as an adjunct to HCTZ, inducing a twofold greater reduction in urine calcium excretion, and completely neutralizing endogenous acid production so as to correct the pre-existing mild metabolic acidosis that an acid-producing diet usually induces in older people. Accordingly, for reducing urine calcium excretion in stone disease and osteoporosis, the combination of HCTZ + KHCO3 may be preferable to that of HCTZ + KCl.


Assuntos
Bicarbonatos/administração & dosagem , Cálcio/urina , Hidroclorotiazida/administração & dosagem , Cloreto de Potássio/administração & dosagem , Inibidores de Simportadores de Cloreto de Sódio/administração & dosagem , Equilíbrio Ácido-Base/efeitos dos fármacos , Acidose/complicações , Acidose/tratamento farmacológico , Idoso , Creatinina/urina , Diuréticos , Método Duplo-Cego , Feminino , Humanos , Concentração de Íons de Hidrogênio , Cálculos Renais/etiologia , Cálculos Renais/prevenção & controle , Masculino , Pessoa de Meia-Idade , Osteoporose/etiologia , Osteoporose/prevenção & controle , Potássio/urina , Sódio/urina
18.
Mayo Clin Proc ; 74(3): 259-63, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10089995

RESUMO

We describe a 19-year-old patient who was receiving home parenteral nutrition in whom lactic acidosis developed. A review of her home parenteral nutrition formula revealed the absence of multivitamins, most significantly thiamine. After thiamine administration, the acidosis resolved, and the patient experienced pronounced clinical improvement. Clinicians must be aware that thiamine is essential for normal glucose metabolism and that thiamine deficiency can lead to lactic acidosis. Thiamine deficiency should be included in the differential diagnosis of lactic acidosis. The recent shortage of intravenous multivitamin preparations has led to documented cases of lactic acidosis as a result of thiamine deficiency, and a previous shortage led to several deaths due to lactic acidosis as a consequence of thiamine deficiency. All patients receiving parenteral nutrition must also receive adequate vitamin supplementation.


Assuntos
Acidose/complicações , Deficiência de Tiamina/etiologia , Acidose/etiologia , Acidose/metabolismo , Acidose Láctica/complicações , Adulto , Feminino , Humanos , Nutrição Parenteral Total/efeitos adversos , Deficiência de Tiamina/metabolismo
19.
Intern Med ; 37(11): 958-61, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9868960

RESUMO

A 69-year-old man with chronic alcoholism was admitted to our hospital due to disturbance of consciousness and oliguria. Emergency laboratory examination revealed metabolic acidosis, hypoglycemia, hyponatremia, mild liver dysfunction, acute renal failure and rhabdomyolysis. After administration of fluids and nutrients and continuous hemodiafiltration, he recovered from all signs and symptoms except for disturbance of consciousness after 7 days. Since severe hypophosphatemia persisted, we administered adequate phosphates, and then his level of consciousness normalized. We discuss the relationships among alcohol abuse, hypophosphatemia and disturbance of consciousness, and recommend that hypophosphatemia be considered a potential cause of disturbance of consciousness in alcoholic patients.


Assuntos
Alcoolismo/complicações , Transtornos da Consciência/etiologia , Hipofosfatemia/complicações , Acidose/sangue , Acidose/complicações , Acidose/terapia , Injúria Renal Aguda/sangue , Injúria Renal Aguda/complicações , Injúria Renal Aguda/terapia , Idoso , Alcoolismo/sangue , Transtornos da Consciência/sangue , Creatinina/sangue , Seguimentos , Hemodiafiltração , Humanos , Hipoglicemia/sangue , Hipoglicemia/complicações , Hipoglicemia/terapia , Hiponatremia/sangue , Hiponatremia/complicações , Hiponatremia/terapia , Hipofosfatemia/sangue , Hipofosfatemia/tratamento farmacológico , Masculino , Mioglobina/sangue , Fosfatos/sangue , Fosfatos/uso terapêutico , Fósforo/sangue , Fósforo/uso terapêutico , Rabdomiólise/sangue , Rabdomiólise/complicações , Rabdomiólise/terapia
20.
Ann Pharmacother ; 31(4): 432-4, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9101004

RESUMO

OBJECTIVE: To report a case of hypocalcemia and hypomagnesemia after ibuprofen overdose. CASE SUMMARY: A 21-month-old boy developed acute renal failure with severe metabolic acidosis after ingestion of ibuprofen 8 g. The infant developed tonic-clonic seizures 46 hours after ingestion, with significant hypocalcemia and hypomagnesemia that required electrolyte replacement to control the seizures. DISCUSSION: To our knowledge this is the first case report of hypocalcemia, hypomagnesemia, and seizures in a patient after ibuprofen overdose. The mechanism is unclear, the situation was probably aggravated by the use of sodium polystyrene sulfonate and furosemide. CONCLUSIONS: In patients with ibuprofen overdose, serum calcium and magnesium concentrations should be evaluated since seizures may be associated with a deficiency of these cations. The management of these patients should include calcium and/or magnesium supplementation when required and furosemide should be avoided.


Assuntos
Anti-Inflamatórios não Esteroides/intoxicação , Hipocalcemia/induzido quimicamente , Ibuprofeno/intoxicação , Magnésio/sangue , Acidose/induzido quimicamente , Acidose/complicações , Overdose de Drogas , Humanos , Hipocalcemia/complicações , Lactente , Masculino , Insuficiência Renal/induzido quimicamente , Insuficiência Renal/complicações , Convulsões/induzido quimicamente , Convulsões/complicações
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