Can paricalcitol increase the effectiveness of n-acetylcysteine in contrast induced acute kidney prophylaxis in rats? A biochemical and histopathological study / ¿Puede el paricalcitol aumentar la eficacia de la n-acetilcisteína en la profilaxis renal aguda inducida por contraste en ratas? Un estudio bioquímico e histopatológico

SUMMARY: N-Acetylcysteine (NAC) is used for contrast induced acut kidney injury (CI-AKI) prophylaxis because of its antioxidant effects. Paricalcitol, which has reno-protective effects, is likely to provide a more effective prophylaxis when added to NAC treatment. The study was designed based on this hypothesis. The study was organised to include 4 groups each consisting of 7 rats. Group 1 was the control group, and Group 2 included rats with CI-AKI. Rats in Group 3 were administered NAC at a dose of 100 mg/kg via oral gavage once a day for 5 days. Rats in group 4 were administered paricalcitol at a dose of 0.4 mcg/kg once a day for 5 days in addition to NAC. CI-AKI was induced after the treatments in both groups. The study was terminated on the sixth day. Samples were collected from the rats' sera and kidney tissues to study oxidant and antioxidant parameters; kidney function tests were also studied. There were significant differences between the contrast nephropathy group (Group 2) and NAC and NAC+paricalcitol groups with respect to serum urea and creatinine levels. When the same groups were compared regarding oxidant (TOS-MDA) and antioxidant (TAC-Paraoxonase) parameters, we observed that the oxidant parameters increased in serum and kidney tissue samples with NAC use, and that effect was strengthened by the addition of paricalcitol to NAC treatment. However, despite increased antioxidant effectiveness, we observed no decrease in urea and creatinine levels when paricalcitol was added for CI-AKI in rats. There was no significant difference between Group 3 and Group 4. Paricalcitol provides a more potent antioxidant effect in both serum and kidney tissue samples when added to NAC treatment in rats with CI-AKI. Despite increased antioxidant parameters, however, paricalcitol does not provide a significant decrease in urea and creatinine levels.

RESUMEN: Debido a sus efectos atioxidantes la N- acetilcisteína (NAC) se usa para la profilaxis de la lesión renal aguda inducida por contraste (CI-AKI). Es probable que el paricalcitol, que tiene efectos renoprotectores, proporcione una profilaxis más eficaz cuando se agrega al tratamiento con NAC. En base a esta hipótesis el estudio fue diseñado para incluir cuatro grupos cada uno compuesto por siete ratas. El grupo 1 fue el grupo control y el grupo 2 incluyó ratas con CI-AKI. A las ratas del Grupo 3 se les administró NAC con una dosis de 100 mg/kg por sonda oral una vez al día, durante 5 días. A las ratas del grupo 4 se les administró paricalcitol a una dosis de 0,4 mcg/kg una vez al día durante 5 días, además de NAC. Se indujo CI-AKI después de los tratamientos en ambos grupos. El estudio finalizó el sexto día. Se recolectaron muestras de suero y tejidos renales de ratas para estudiar los parámetros oxidantes y antioxidantes; También se estudiaron las pruebas de función renal. Hubo diferencias significativas entre el grupo de nefropatía por contraste (Grupo 2) y los grupos NAC y NAC+paricalcitol con respecto a los niveles séricos de urea y creatinina. Cuando se compararon los mismos grupos con respecto a los parámetros oxidantes (TOS-MDA) y antioxidantes (TAC-Paraoxonase), observamos que los parámetros oxidantes aumentaron en muestras de suero y tejido renal con el uso de NAC, y ese efecto se vio reforzado por la adición de paricalcitol a tratamiento NAC. Sin embargo, a pesar de una mayor eficacia antioxidante, no observamos una disminución en los niveles de urea y creatinina cuando se agregó paricalcitol para CI-AKI en ratas. No hubo diferencias significativas entre el Grupo 3 y el Grupo 4. El paricalcitol proporciona un efecto antioxidante más potente tanto en muestras de suero como de tejido renal cuando se agrega al tratamiento con NAC en ratas con CI-AKI. Sin embargo, a pesar del aumento de los parámetros antioxidantes, el paricalcitol no proporciona una disminución sig- nificativa en los niveles de urea y creatinina.

Uremic lion face syndrome / Face Leonina na Síndrome Urêmica

Abstract Mineral bone disorder is a common feature of chronic kidney disease. Lion face syndrome is rare complication of severe hyperparathyroidism in end-stage renal disease patients, which has been less commonly reported due to dialysis and medical treatment advances in the last decade. The early recognition of the characteristic facial deformity is crucial to prompt management and prevent severe disfigurement. The authors present a rare case of severe hyperparathyroidism presenting with lion face syndrome and bone fractures.

Resumo O distúrbio mineral e ósseo é uma característica comum da doença renal crônica. A síndrome da face leonina é uma complicação rara do hiperparatireoidismo grave em pacientes com doença renal terminal, que tem sido menos relatada devido aos avanços na diálise e tratamento médico na última década. O reconhecimento precoce da deformidade facial característica é crucial para estimular o tratamento precoce e prevenir a desfiguração severa. Os autores apresentam um caso raro de hiperparatireoidismo grave, apresentando síndrome da face leonina e fraturas ósseas.

Deficiência da Vitamina D e doenças cardiovasculares / Vitamin D deficiency and cardiovascular diseases

A vitamina D é considerada um hormônio esteroide com amplo espectro de atuação no organismo humano. Sua ação ocorre a partir da ligação do seu metabólito ativo (1α, 25-di-hidroxivitamina D) com seu receptor (VDR) que se encontra presente em todo o organismo, inclusive nas células musculares lisas vasculares e nos cardiomiócitos. Inicialmente, a deficiência de vitamina D havia sido relacionada apenas com alterações no sistema musculoesquelético. Porém, nos últimos anos, pesquisadores têm demonstrado sua relação com diversas patologias pertencentes a outros sistemas, tais como as doenças cardiovasculares. O objetivo deste trabalho foi revisar a fisiopatologia da vitamina D, descrever sua relação com as doenças cardiovasculares com base nas publicações mais recentes e destacar os resultados da suplementação vitamínica na prevenção de tais patologias

Effect of one time high dose "stoss therapy" of vitamin D on glucose homeostasis in high risk obese adolescents

ABSTRACT Objective To study the effect of using a one time high dose "stoss therapy" of vitamin D2 (ergocalciferol: VD2) on indices of insulin sensitivity {whole body sensitivity index: WBISI} and secretion {insulinogenic index: IGI} measured during an oral glucose tolerance test (OGTT) in obese adolescents with VDD (25 OHD; serum metabolite of vit D: < 30 ng/dL). Subjects and methods In a randomized placebo controlled cross over design 20 obese adolescents with vitamin D deficiency (VDD) had baseline OGTT. Arm A received one time high dose 300,000 IU of ergocalciferol and Arm B received placebo. After 6 weeks the adolescents were reassigned to Arm A if they were in Arm B and vice versa. 25OHD, calcium, parathyroid hormone, comprehensive metabolic panel, urine calcium creatinine ratio were measured at each study visit. OGTTs to assess indices of sensitivity and secretion were done at baseline, 6 weeks and 12 weeks respectively. Results Adolescents were obese and insulin resistant (mean ± SD: mean age = 15.1 ± 1.9 years; BMI: 32.7 ± 9.8; homeostatic model of insulin resistance: HOMA-IR: 4.2 ± 2.8). Stoss therapy with VD2 increased 25OHD from baseline (16.7 ± 2.9 to 19.5 ± 4.5; p = 0.0029) when compared to the placebo. WBISI (2.8 ± 1.9) showed a trend towards improvement in Rx group (p = 0.0577) after adjustment for covariates. IGI (3 ± 2.2) showed an improvement in both Rx and placebo groups. Conclusions Our study demonstrated that using a high dose of VD2 (300,000 IU) did not have any beneficial effect on insulin sensitivity (whole body sensitivity index {WBISI}) and secretory indices (insulinogenic index {IGI}) in obese adolescents. High dose "stoss therapy" of VD2 did not appear to have any beneficial effect on glucose homeostasis on obese adolescents.

Vitamin D in prostate cancer / 亚洲男科学杂志(英文版)

Signaling through the vitamin D receptor has been shown to be biologically active and important in a number of preclinical studies in prostate and other cancers. Epidemiologic data also indicate that vitamin D signaling may be important in the cause and prognosis of prostate and other cancers. These data indicate that perturbation of vitamin D signaling may be a target for the prevention and treatment of prostate cancer. Large studies of vitamin D supplementation will be required to determine whether these observations can be translated into prevention strategies. This paper reviews the available data in the use of vitamin D compounds in the treatment of prostate cancer. Clinical data are limited which support the use of vitamin D compounds in the management of men with prostate cancer. However, clinical trials guided by existing preclinical data are limited.

Efecto del ergocalciferol (vitamina D2) y el colecalciferol (vitamina D3) sobre el control de la glicemia en ratas / Effect of ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3) on glycemic control in rats

Objetivo: Determinar el efecto del Ergocalciferol (vitamina D2) y el colecalciferol (vitamina D3) sobre el control de la glicemia en ratas. Materiales y métodos: Estudio experimental. Se utilizó 48 ratas machos Wistar de 12 semanas de edad, con un peso de 200 ± 50 g, distribuidas de manera aleatoria en ocho grupos de seis: control negativo (suero fisiológico a 2 mL/dieta balanceada); control positivo (suero fisiológico a 2 mL/dieta modificada); EXP 1 (vitamina D2 a 10000 UI/kg /dieta modificada); EXP 2 (vitamina D2 a 35000 UI/kg /dieta modificada); EXP 3 (vitamina D2 a 70000 UI/kg /dieta modificada); EXP 4 (vitamina D3 a 10000 UI/kg /dieta modificada); EXP 5 (vitamina D3 a 35000 UI/kg /dieta modificada), y EXP 6 (vitamina D3 a 70000 UI/kg /dieta modificada); se administraron dos tipos de dietas (dieta balanceada y dieta modificada a base de colesterol y fructuosa) y vitaminas D2 y D3 de manera conjunta durante las 13 semanas de estudio. Resultados: El promedio de glicemia del grupo control negativo (CN) fue 80,17 mg/dL; en los grupos experimentales fueron: 91,17 mg/dL (EXP1); 90,17 mg/dL (EXP2); 87,67 mg/dL (EXP3); 91,67 mg/dL (EXP4); 88,33 mg/dL (EXP5); 81,83 mg/dL (EXP6), y en el grupo control positivo (CP) fue 134,84 mg/dL. Conclusión: Los grupos con dieta modificada y que recibieron ergocalciferol (vitamina D2) o colecalciferol (vitamina D3) mostraron niveles menores de glicemia en comparación con los que no recibieron suplementación, no habiendo diferencias significativas entre la utilización de algún tipo de vitamina D o las dosis de 35000 y 70000 UI.

Paricalcitol attenuates lipopolysaccharide-induced inflammation and apoptosis in proximal tubular cells through the prostaglandin E₂ receptor EP4

BACKGROUND: Vitamin D is considered to exert a protective effect on various renal diseases but its underlying molecular mechanism remains poorly understood. This study aimed to determine whether paricalcitol attenuates inflammation and apoptosis during lipopolysaccharide (LPS)-induced renal proximal tubular cell injury through the prostaglandin E₂ (PGE₂) receptor EP4. METHODS: Human renal tubular epithelial (HK-2) cells were pretreated with paricalcitol (2 ng/mL) for 1 hour and exposed to LPS (1 μg/mL). The effects of paricalcitol pretreatment in relation to an EP4 blockade using AH-23848 or EP4 small interfering RNA (siRNA) were investigated. RESULTS: The expression of cyclooxygenase-2, PGE₂, and EP4 were significantly increased in LPS-exposed HK-2 cells treated with paricalcitol compared with cells exposed to LPS only. Paricalcitol prevented cell death induced by LPS exposure, and the cotreatment of AH-23848 or EP4 siRNA offset these cell-protective effects. The phosphorylation and nuclear translocation of p65 nuclear factor-kappaB (NF-κB) were decreased and the phosphorylation of Akt was increased in LPS-exposed cells with paricalcitol treatment. AH-23848 or EP4 siRNA inhibited the suppressive effects of paricalcitol on p65 NF-κB nuclear translocation and the activation of Akt. The production of proinflammatory cytokines and the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positive cells were attenuated by paricalcitol in LPS exposed HK-2 cells. The cotreatment with an EP4 antagonist abolished these anti-inflammatory and antiapoptotic effects. CONCLUSION: EP4 plays a pivotal role in anti-inflammatory and antiapoptotic effects through Akt and NF-κB signaling after paricalcitol pretreatment in LPS-induced renal proximal tubule cell injury.

A lack of association between vitamin D-binding protein and 25-hydroxyvitamin D concentrations in pediatric type 1 diabetes without microalbuminuria

PURPOSE: Vitamin D deficiency is reported to be more common in type 1 diabetes patients and might be associated with the increased urinary loss of vitamin D binding protein (VDBP) consequent to impaired 25-hydroxyvitamin D (25(OH)D) circulation. We aimed to evaluate the possible increased urinary loss of VDBP, a correlation between VDBP and circulating 25(OH)D level, and risk factors influencing low vitamin D level in pediatric type 1 diabetes patients without microalbuminuria. METHODS: This is a cross-sectional study of subjects who visited Seoul National University Children’s Hospital between January and March 2013. Forty-two type 1 diabetes patients and 29 healthy controls were included. Biochemical parameters including serum and urine VDBP concentrations were analyzed. RESULTS: There was no significant difference in the frequency of vitamin D deficiency or serum 25(OH)D level between the 2 groups. The serum and urine VDBP concentrations did not show any difference between the 2 groups. Serum 25(OH) D level did not correlate with serum or urine VDBP. Multivariate regression analysis revealed that daylight outdoor hours (β=2.948, P=0.003) and vitamin D intake (β=2.865, P=0.003) affected the 25(OH)D level; the presence of type 1 diabetes or urinary VDBP excretion was not significant. CONCLUSIONS: In pediatric type 1 diabetes patients, urinary VDBP excretion did not contribute to low serum 25(OH)D level in the setting of normoalbuminuria. The factors associated with 25(OH)D level during winter periods were daylight outdoor hours and vitamin D intake. Further studies including both micro- and macroalbuminuria patients with type 1 diabetes are warranted.

Effectiveness and safety of a 6-month treatment with paricalcitol in patients on hemodialysis with secondary hyperparathyroidism / Eficácia e segurança do tratamento de 6 meses com paricalcitol em pacientes em hemodiálise com hiperparatiroidismo secundário

Abstract Introduction: The mineral bone disorder, particularly secondary hyperparathyroidism, in chronic kidney disease (CKD) has a systemic impact affecting not only bone metabolism. Therefore its correction is important to prevent cardiovascular, inflammatory and immune diseases. Objective To assess the effectiveness and safety of intravenous paricalcitol administered over a 6 month period for the treatment of secondary hyperparathyroidism (SHPT) in patients undergoing conventional hemodialysis, with close follow-up of treatment response. Methods: A phase 4 clinical trial was performed comparing clinical and laboratory data before and after 6 months of treatment. SHPT patients undergoing hemodialysis who were naïve to vitamin D metabolites or had failed to current therapy were included. Clinical and laboratory characteristics were analyzed. Efficacy analyses were based on intact parathyroid hormone (iPTH) levels and were performed using data from patients who completed 6 months of treatment. Results: Nineteen of the 26 patients enrolled completed 6 months of treatment. All patients exhibited reduced baseline iPTH levels (mean reduction, 371.8 pg/mL; 95% CI, 273.3-470.2 pg/mL]; 17 patients (89.5%) had reductions exceeding 30%. Twelve patients (63%) achieved therapeutic success (defined as iPTH serum levels 150-300 pg/mL), with a median time of 2 months from the beginning of treatment. All reported episodes of hypercalcemia (n = 2) and hyperphosphatemia (n = 34) were asymptomatic. No major therapy-related serious AEs were reported. Conclusion: Paricalcitol was safely administered and was associated with significant decreases in iPTH levels over the study period.

Resumo Introdução: A doença metabólica óssea, em particular o hiperparatireoidismo secundário, na doença renal crônica (DRC) tem um impacto sistêmico que afeta nem só o metabolismo ósseo. Por tanto, sua correção é importante para prevenir as doenças do sistema imunitário, inflamatório e cardiovascular. Objetivo: Avaliar a eficácia e a segurança do paricalcitol intravenoso administrado durante um período de 6 meses no tratamento do hiperparatireoidismo secundário (SHPT) em pacientes submetidos a hemodiálise convencional, com acompanhamento de perto da resposta do tratamento. Métodos: Realizou-se um ensaio clínico de fase 4 que comparava os dados clínicos com os dados do laboratório antes e depois dos 6 meses de tratamento. Incluíram-se os pacientes SHPT em hemodiálise sem experiência com os metabólitos da vitamina D ou que fracassaram com a terapia em uso. Analisaram-se as características clínicas e de laboratório. As análises de eficácia se basearam nos níveis do hormônio da paratireóide intacto (iPTH) e foram realizadas usando dados dos pacientes que completaram os 6 meses de tratamento. Resultados: Dezenove dos 26 pacientes registrados completaram os 6 meses de tratamento. Todos os pacientes mostraram níveis de referência iPTH reduzidos (redução média, 371,8 pg/mL; 95% CI, 273,3-470.2 pg/mL]; 17 pacientes (89,5%) tiveram reduções superiores a 30%. Doze pacientes (63%) conseguiram o sucesso terapêutico (definido como níveis de soros iPTH de 150-300 pg/mL), com um tempo médio de 2 meses a partir do início do tratamento. Todos os episódios de hipercalcemia (n = 2) e de hiperfosfatemia (n = 34) reportados foram assintomáticos. Não se informaram AEs graves importantes relacionados à terapia. Conclusão: O paricalcitol foi administrado de forma segura e se associou às reduções significativas nos níveis de iPTH durante o período do estudo.

Cost-effectiveness analysis of paricalcitol versus calcitriol for the treatment of SHPT in dialytic patients from the SUS perspective / Análise de custo-efetividade de paricalcitol versus calcitriol no tratamento do HPTS em pacientes do SUS dialíticos, da perspectiva

Abstract Introduction: Secondary hyperparathyroidism (SHPT) is a consequence of chronic kidney disease. The treatment at the Brazilian Unified Heath System (SUS) is performed with calcitriol, a drug which favors hypercalcemia and/or hyperphosphatemia, hindering the control of SHPT. Another option is paricalcitol, which causes parathormone (PTH) suppression faster than calcitriol, with minor changes in calcium-phosphorus product and calcium and phosphorus serum levels. Objective: This study aims to develop a cost-effectiveness analysis of paricalcitol versus calcitriol for patients in dialytic treatment with SHPT, from the SUS perspective. Methods: A Markov decision model was developed for patients ≥ 50 years old with end stage renal disease in dialytic treatment and SHPT. Quarterly cycles and a lifetime time horizon were considered. Life years (LY) gained were assessed as clinical outcome. Clinical and economic inputs were obtained from systematic literature review and official databases. Costs are presented in Brazilian real (BRL), for the year 2014. Results: In the base case: paricalcitol generated a clinical benefit of 16.28 LY gained versus 14.11 LY gained with calcitriol, total costs of BRL 131,064 and BRL 114,262, respectively, determining an incremental cost-effectiveness ratio of BRL 7,740 per LY gained. The data robustness was confirmed by the sensitivity analysis. Conclusions: According to cost-effectiveness threshold recommended by the World Health Organization for 2013, the treatment of SHPT in patients on dialysis with paricalcitol is cost-effective when compared to calcitriol, from the public healthcare system perspective, in Brazil.

Resumo Introdução: O hiperparatireoidismo secundário (HPTS) é uma consequência da doença renal crônica. O tratamento no SUS é realizado com calcitriol, que favorece a hipercalcemia e/ou hiperfosfatemia, dificultando o controle do HPTS. Uma opção clinicamente relevante é o paricalcitol, que ocasiona a supressão do paratormônio (PTH) de forma mais rápida que o calcitriol e com menores alterações nas taxas séricas de cálcio, fósforo e do produto cálcio-fósforo. Objetivo: Este trabalho tem como objetivo desenvolver uma análise de custo-efetividade de paricalcitol versus calcitriol para pacientes em diálise com HPTS, perspectiva do SUS. Métodos: Foi desenvolvido um modelo de decisão de Markov para a população ≥ 50 anos, com DRC em diálise e HPTS. Foram considerados ciclos trimestrais e um horizonte temporal lifetime. O desfecho clínico avaliado foram os anos de vida ganhos. Dados foram obtidos a partir de revisão sistemática da literatura e bases de dados oficiais. Custos em reais (R$), ano de 2014. Resultados: No caso base: paricalcitol gerou benefício clínico de 16,28 anos de vida ganhos versus 14,11 anos de vida ganhos com calcitriol, custos totais de R$ 131.064 e R$ 114.262, respectivamente. A razão de custo-efetividade incremental de R$ 7.740 por ano de vida salvo. Dados robustos confirmados pela análise de sensibilidade. Conclusão: De acordo com o limiar de custo-efetividade recomendado pela Organização Mundial de Saúde para o ano de 2013, o tratamento de pacientes com HPTS em diálise com paricalcitol é custo-efetivo, comparado ao calcitriol, perspectiva SUS.

Effect of multivitamin on serum 25-hydroxy vitamin D level in postmenopausal women: A randomized, double-blind, placebo-controlled trial

OBJECTIVE: To determine the effects of multivitamin vitamin D 300 or 600 units on serum 25 hydroxyvitamin D (25(OH)D) level after 4 weeks of supplementation in postmenopausal women with vitamin D insufficiency. STUDY DESIGN: Randomized double-blind, placebo-controlled trial. METHODS: Postmenopausal women who had vitamin D insufficiency were recruited into the study. The participants were randomized to 3 groups of 4-week treatment period with multivitamin (GPO, Governmental Pharmacy Organization) 2 tablets (contained vitamin D2 amount 600 units), multivitamin 1 tablet (contained vitamin D2 amount 300 units) or placebo. At baseline and after 4 weeks of supplementation, serum 25(OH)D were determined with electrochemilumines-cence immunoassay (Cobas, Roche Diagnostics) and level change of 25(OH)D level were compared among the groups. RESULTS: Out of 144 participants, 49.3% had vitamin D deficiency (<20 ng/ml) and 50.7% had vitamin D insufficiency (<30 ng/ml). However, after 4 weeks of the GPO oral multivitamin, serum 25(OH)D levels significantly increased from 19.4 ± 6.3 ng/ml at baseline to 22.2 ± 5.2 ng/ml (P = 0.01) and from 19.5 ± 5.0 ng/ml to 23.3 ± 5.2 ng/ml (P < 0.01) in the groups receiving vitamin D 300 IU and 600 IU/day, respectively. Approximately, 10% of those who took vitamin D had serum 25(OH)D level above the insufficiency level within 4 weeks. There was no significant changes of serum 25(OH)D after 4 weeks in the placebo group. CONCLUSION: Daily supplementation of the generic multivitamin containing vitamin D2 300 and 600 IU daily for 4 weeks significantly increased mean serum 25(OH)D from baseline up above the deficiency level.

Recomendações da Sociedade Brasileira de Endocrinologia e Metabologia (SBEM) para o diagnóstico e tratamento da hipovitaminose D / Recommendations of the Brazilian Society of Endocrinology and Metabology (SBEM) for the diagnosis and treatment of hypovitaminosis D

Objetivo Apresentar uma atualização sobre o diagnóstico e tratamento da hipovitaminose D baseada nas mais recentes evidências científicas. Materiais e métodos O Departamento de Metabolismo Ósseo e Mineral da Sociedade Brasileira de Endocrinologia e Metabologia (SBEM) foi convidado a conceber um documento seguindo as normas do Programa Diretrizes da Associação Médica Brasileira (AMB). A busca dos dados foi realizada por meio do PubMed, Lilacs e SciELO e foi feita uma classificação das evidências em níveis de recomendação, de acordo com a força científica por tipo de estudo. Conclusão Foi apresentada uma atualização científica a respeito da hipovitaminose D que servirá de base para o diagnóstico e tratamento dessa condição no Brasil. .

Objective The objective is to present an update on the diagnosis and treatment of hypovitaminosis D, based on the most recent scientific evidence. Materials and methods The Department of Bone and Mineral Metabolism of the Brazilian Society of Endocrinology and Metabology (SBEM) was invited to generate a document following the rules of the Brazilian Medical Association (AMB) Guidelines Program. Data search was performed using PubMed, Lilacs and SciELO and the evidence was classified in recommendation levels, according to the scientific strength and study type. Conclusion A scientific update regarding hypovitaminosis D was presented to serve as the basis for the diagnosis and treatment of this condition in Brazil. .

Papel de las mitocondrias y el estrés oxidativo en el proceso inflamatorio renal / Mitochondria and oxidative stress participation in renal inflammatory process

La muerte celular programada y la fibrosis renal son procesos inherentes a la enfermedad renal crónica y, en tal sentido, ha sido recientemente descripta una clara desregulación de la maquinaria respiratoria mitocondrial en pacientes con enfermedad renal crónica asociada con un aumento del estrés oxidativo. Las células tubulares lesionadas vinculadas a los macrófagos intersticiales y miofibroblastos producen citoquinas y factores de crecimiento que promueven un estado inflamatorio, inducen la apoptosis de las células tubulares y facilitan la acumulación de matriz extracelular. La angiotensina II desempeña un papel central en la fibrogénesis renal y conduce a una rápida progresión de la enfermedad renal crónica. Los niveles crecientes de la angiotensina II inducen citoquinas pro-inflamatorias, la activación de NF-kB, moléculas de adhesión, quimiocinas, factores de crecimiento y estrés oxidativo. Toda la evidencia actual sugiere que la angiotensina II aumenta el estrés oxidativo mitocondrial, regula la inducción de apoptosis y condiciona al estado inflamatorio. Por lo tanto, existiría un papel determinante de las mitocondrias y el estrés oxidativo en el proceso inflamatorio renal. Finalmente, esta revisión resume nuestro actual conocimiento acerca de los posibles mecanismos que contribuirían con la apoptosis modulada por la inflamación y/o el estrés oxidativo durante la enfermedad renal crónica. Además, se propone un nuevo concepto de herramientas anti-inflamatorias que regulan el estrés oxidativo mitocondrial lo cual afectaría directamente al proceso inflamatorio y la apoptosis. Esta idea podría tener consecuencias atractivas sobre el tratamiento de patologías inflamatorias renales y de otras afines.

The apoptosis and renal fibrosis are processes inherent to the chronic kidney disease, and consequently a clear deregulation of the mitochondrial respiratory mechanism has been described in patients with chronic renal disease associated to an increase of the oxidative stress. The injured tubular cells linked to the interstitial macrophages and myofibroblasts produce cytokines and growth factors that encourage an inflammatory condition, inducing the apoptosis of the tubular cells and enabling the accumulation of the extracellular matrix. The angiotensin II has a central role in the renal fibrogenesis leading to a rapid progression of the chronic kidney disease. The growing levels of the angiotensin II induce pro-inflammatory cytokines, the activation of NF-kB, adhesion molecules,chemokines, growth factors, and oxidative stress. The current evidence suggests that the angiotensin II increases the mitochondrial oxidative stress, regulates the induction of the apoptosis and conditions the inflammatory process. Therefore the mitochondria and the oxidative stress would play a determinant role in the renal inflammatory process. Finally, this review summarizes our present knowledge regarding the possible mechanisms that would contribute to the apoptosis conditioned by inflammation and/or oxidative stress during the chronic renal disease. Additionally, a new concept of the anti-inflammatory tools is proposed to regulate the mitochondrial oxidative stress that would directly affect the inflammatory process and apoptosis. This concept could have positive consequences on the treatment of renal inflammatory pathologies and related diseases.

Antiapoptotic Effect of Paricalcitol in Gentamicin-induced Kidney Injury

While the anti-apoptotic effect of paricalcitol has been demonstrated in various animal models, it is not yet clear whether paricalcitol attenuates the apoptosis in gentamicin (GM)-induced kidney injury. We investigated the effect of paricalcitol on apoptotic pathways in rat kidneys damaged by GM. Rats were randomly divided into three groups: 1) Control group (n=8), where only vehicle was delivered, 2) GM group (n=10), where rats were treated with GM (150 mg/kg/day) for 7 days, 3) PARI group (n=10), where rats were co-treated with paricalcitol (0.2 microg/kg/day) and GM for 7 days. Paricalcitol attenuated renal dysfunction by GM administration in biochemical profiles. In terminal deoxynucleotidyl transferase dUTP nick end labeling staining, increased apoptosis was observed in GM group, which was reversed by paricalcitol co-treatment. Immunoblotting using protein samples from rat cortex/outer stripe of outer medulla showed increased Bax/Bcl-2 ratio and cleaved form of caspase-3 in GM group, both of which were reversed by paricalcitol. The phosphorylated Jun-N-terminal kinase (JNK) expression was increase in GM, which was counteracted by paricalcitol. The protein expression of p-Akt and nitro-tyrosine was also enhanced in GM-treated rats compared with control rats, which was reversed by paricalcitol co-treatment. Paricalcitol protects GM-induced renal injury by antiapoptotic mechanisms, including inhibition of intrinsic apoptosis pathway and JNK.

Total 25-OH Vitamin D Concentrations in Chinese, Malays and Indians

No abstract available.

¿Es equivalente la suplementación diaria con vitamina D2 o vitamina D3 en adultos mayores? / Is daily supplementation with vitamin D2 equivalent to daily supplementation with vitamin D3 in the elderly?

Tanto la equivalencia entre colecalciferol (D3) y ergocalciferol (D2), como las dosis y forma de administración de ambos, son actualmente un tema controvertido. El objetivo de este estudio fue comparar la efectividad de 800 UI/día de D2 (gotas) y D3 (comprimidos) para alcanzar niveles adecuados de 25 hidroxivitamina D (25OHD) (= 30 ng/ml). Veintiún mujeres posmenopáusicas que vivían en la Ciudad de Buenos Aires, edad promedio ( ± DS) 77.1 ± 6.8 años fueron incluidas y asignadas en forma aleatoria a uno de los siguientes grupos: GD2 (n = 13): 800 UI (gotas) y GD3 (n = 8): 800 UI (comprimidos). Se midió 25OHD sérica (RIA-DIASORIN) basal y a los 7, 28 y 45 días del estudio. Basalmente, 19 de las 21 mujeres presentaron niveles de deficiencia de 25(OH)D (< 20 ng/ml): GD2: 14.0 ± 4.8 y GD3: 13.2 ± 4.9 (NS). Se observó en el día 7 un incremento del ~25% solo en GD3 y un aumento significativo al final del estudio en ambos grupos, sin alcanzar los valores adecuados de 25OHD (GD2: 17.4 ± 5.5 vs. GD3:22.9 ± 4.6 ng/ml p < 0.001). La administración por 45 días de 800 UI de vitamina D3 fue más efectiva que D2 para incrementar los niveles de 25OHD, aunque ambas fueron insuficientes para alcanzar niveles adecuados de 25OHD (= 30 ng/ml).

The equivalence of cholecalciferol (D3) and ergocalciferol (D2) as well as their corresponding doses and administration route remain controversial to date. The aim of this study was to compare the effectiveness of daily supplementation with 800 IU of D2 (drops) and D3 (pills) on 25-hydroxivitamin D (25OHD) levels (= 30 ng/ml). Twenty-one ambulatory postmenopausal women from Buenos Aires City with a mean ( ± SD) age of 77.1 ± 6.8 years were included. The participants were randomly assigned to one of the following groups: GD2 (n = 13): 800 IU (drops) and GD3 (n = 8): 800 IU (pills). Serum 25OHD levels were measured (RIA-DIASORIN) at baseline, and at 7, 28 and 45 days. Nineteen out of twenty one women showed deficient levels of 25OHD at baseline (< 20 ng/ml): GD2: 14.0 ± 4.8 ng/ml and GD3: 13.2 ± 4.9 ng/ml (NS). Whereas only GD3 exhibited an increase (~25%) at 7 days, both groups showed a significant increase at the end of the study. However, neither attained adequate 25OHD levels (GD2: 17.4 ± 5.5 vs. GD3:22.9 ± 4.6 ng/ml; p < 0.001). Administration of 800 IU of vitamin D3 during 45 days was more effective than D2 in increasing 25OHD, but both failed to achieve adequate levels of 25OHD (= 30 ng/ml). but neither succeeded in achieving adequate levels of 25OHD (= 30 ng/ml).

Cardiorenal syndrome and vitamin D receptor activation in chronic kidney disease

Cardiorenal syndrome (CRS) refers to a constellation of conditions whereby heart and kidney diseases are pathophysiologically connected. For clinical purposes, it would be more appropriate to emphasize the pathophysiological pathways to classify CRS into: (1) hemodynamic, (2) atherosclerotic, (3) uremic, (4) neurohumoral, (5) anemic??hematologic, (6) inflammatory-oxidative, (7) vitamin D receptor (VDR) and/or FGF23-, and (8) multifactorial CRS. In recent years, there have been a preponderance data indicating that vitamin D and VDR play an important role in the combination of renal and cardiac diseases. This review focuses on some important findings about VDR activation and its role in CRS, which exists frequently in chronic kidney disease patients and is a main cause of morbidity and mortality. Pathophysiological pathways related to suboptimal or defective VDR activation may play a role in causing or aggravating CRS. VDR activation using newer agents including vitamin D mimetics (such as paricalcitol and maxacalcitol) are promising agents, which may be related to their selectivity in activating VDR by means of attracting different post-D-complex cofactors. Some, but not all, studies have confirmed the survival advantages of D-mimetics as compared to non-selective VDR activators. Higher doses of D-mimetic per unit of parathyroid hormone (paricalcitol to parathyroid hormone ratio) is associated with greater survival, and the survival advantages of African American dialysis patients could be explained by higher doses of paricalcitol (>10 microg/week). More studies are needed to verify these data and to explore additional avenues for CRS management via modulating VDR pathway.

Suppressive Effect of 19-nor-1alpha-25-Dihydroxyvitamin D2 on Gastric Cancer Cells and Peritoneal Metastasis Model

The active metabolite of vitamin D, 1,25-dihydroxyvitamin D3 (calcitriol), inhibits the growth of several types of human cancer cells in vitro, but its therapeutic use is limited because it causes hypercalcemia. Among its analogs, 19-nor-1,25-dihydroxyvitamin D2 (paricalcitol), has fewer calcemic effects and exhibits an activity equipotent to that of calcitriol. We assessed the antitumor and anti-inflammatory effects of paricalcitol in gastric cancer cells, and evaluated the potential role of vitamin D in the treatment of peritoneal metastatic gastric cancer. In this study, treatment with paricalcitol inhibited gastric cancer cell growth and induced cell cycle arrest. Paricalcitol also induced apoptosis and showed anti-inflammatory activity. Moreover, the growth of intraperitoneal metastases in vivo was reduced in mice treated with paricalcitol. 18F-FDG uptake was significantly lower in the paricalcitol group compared to control group (SUV; control group 13.2 +/- 5.3 vs paricalcitol group 4.5 +/- 3.0). Intraperitoneal tumor volume was significantly lower in paricalcitol treated mice (control group 353.2 +/- 22.9 mm3 vs paricalcitol group 252.0 +/- 8.4 mm3). These results suggest that the vitamin D analog, paricalcitol, has anticancer activity on gastric cancer cells by regulation of the cell cycle, apoptosis, and inflammation.

relation between Vitamin D deficiency and fibromyalgia syndrome in women

To define the relationship between vitamin D deficiency and fibromyalgia syndrome. This is a prospective cohort study for description of a medical disorder. The study was carried out in Sultan Bin Abdulaziz Humanitarian City, Riyadh, Kingdom of Saudi Arabia from May 2007 to March 2010. One hundred women suffering from fibromyalgia syndrome were included. Blood level of 25-hydroxyvitamin D [25[OH] D] was estimated at initial visit and every 4 weeks until its level exceeded 50 ng/mL. The patients with vitamin D deficiency were treated with ergocalciferol 50,000 IU once weekly until their blood level of 25[OH] D exceeded 50 ng/mL. The number of tender points and the revised Fibromyalgia Impact Questionnaire [FIQR] score were used to assess the fibromyalgia before and after vitamin D repletion. Among the 100 fibromyalgia women, there were 61 women with 25[OH] D deficiency; with vitamin D supplementation, only 42 women showed a significant improvement when their blood level of 25 [OH] D became >30 ng/mL, this improvement became more significant when their blood level of 25[OH] D exceeded 50 ng/ mL. Vitamin D deficiency has to be considered in the management of fibromyalgia syndrome