Intestinal absorption of vitamin D: a systematic review.

Context: Vitamin D is frequently prescribed as a supplement, yet its absorption remains poorly understood. Objective: This systematic review was performed to evaluate data on mechanisms involved in the intestinal absorption of vitamin D. Data Sources: PubMed, Embase, and Cochrane Library databases were searched. Study Selection: The following studies were included: experimental laboratory studies of vitamin D absorption through the enterocyte brush-border membrane; absorption tests that used radiolabeled vitamin D; and clinical trials in adults that investigated a single dose of cholecalciferol or ergocalciferol and reported at least 2 measurements of serum cholecalciferol, ergocalciferol, or 25-hydroxyvitamin D. Data Extraction: From 2069 articles identified, 46 met the inclusion criteria. Results: Different methods were employed to evaluate vitamin D absorption. Recent research suggests that vitamin D absorption is not an exclusive simple diffusion process. Vitamin D was better absorbed when it was consumed with fat-containing meals, but absorption also occurred without fat or oily vehicles. Factors that modified cholesterol absorption also altered vitamin D absorption. Conclusion: Vitamin D is probably absorbed through passive diffusion and a mechanism involving membrane carriers, especially cholesterol transporters, although data remain scarce. Some data suggest that fat, when consumed concomitantly with vitamin D, improves vitamin D absorption.

Glycans as Regulatory Elements of the Insulin/IGF System: Impact in Cancer Progression.

The insulin/insulin-like growth factor (IGF) system in mammals comprises a dynamic network of proteins that modulate several biological processes such as development, cell growth, metabolism, and aging. Dysregulation of the insulin/IGF system has major implications for several pathological conditions such as diabetes and cancer. Metabolic changes also culminate in aberrant glycosylation, which has been highlighted as a hallmark of cancer. Changes in glycosylation regulate every pathophysiological step of cancer progression including tumour cell-cell dissociation, cell migration, cell signaling and metastasis. This review discusses how the insulin/IGF system integrates with glycosylation alterations and impacts on cell behaviour, metabolism and drug resistance in cancer.

From stable disease to acute-on-chronic liver failure: Circulating cytokines are related to prognosis in different stages of cirrhosis.

INTRODUCTION: Although both pro- and anti-inflammatory circulating cytokines are known to be elevated in liver cirrhosis, its clinical significance is not completely recognized. Our aim was to evaluate the prognostic significance of circulating cytokines interleukin (IL)-6, IL-17 and IL-10 in different stages of cirrhosis. METHODS: This prospective study included two cohorts: (1) stable cirrhosis attended in the Outpatient Clinic (n=118), and (2) subjects hospitalized for acute decompensation (AD) (n=130). Thirty healthy subjects served as control group. RESULTS: Patients with cirrhosis exhibited higher levels of cytokines as compared to controls. In stable cirrhosis, during a median follow-up of 17months, liver-related events occurred in 26 patients. Higher IL-10 levels and Child-Pugh B/C were independently associated with reduced event-free survival. In AD cohort, death after 90days of follow-up occurred in 39 patients and was independently associated with ascites, higher IL-6 and model for end-stage liver disease. IL-6 levels also showed higher AUROC than CRP for predicting bacterial infection in the AD cohort (0.831±0.043vs. 0.763±0.048, respectively). IL-17 decreased at third day of hospitalization only in patients who progressed to death. Higher IL-6 levels were observed in acute-on-chronic liver failure (ACLF) patients even in the absence of bacterial infection whereas IL-10 was higher only in subjects with infection-related ACLF. Higher IL-10 and IL-17 levels were associated with progression to death in ACLF. CONCLUSIONS: The pattern of immune response seems to vary according to the phase of cirrhosis and is related to prognosis, from stable disease to ACLF.

Autonomia profissional da enfermeira: algumas reflexões / Professional autonomy of the nurse: some reflections

Objetivo: Refletir sobre a autonomia profissional da enfermeira no contexto do modelo assistencial biomédico. Métodos: Reflexão construída a partir do referencial teórico sobre o processo de trabalho em saúde e em enfermagem. Resultados: Identificou-se que no modelo biomédico a autonomia profissional da enfermeira é limitada e condicionada pelas decisões do profissional médico (cujo processo de trabalho ordena o consumo de ações e serviços de saúde), pela frágil construção de um corpo de saberes próprio à profissão e pela crescente divisão técnica do trabalho em saúde e em enfermagem. Conclusão: A enfermeira poderá ampliar sua autonomia profissional em outros modelos assistenciais que permitam a construção de saberes próprios ao campo da enfermagem, como os campos da Saúde Mental, da Obstetrícia e da Atenção Primária em Saúde. Esses são espaços propícios para a enfermeira desenvolver uma prática profissional autônoma e consoante com o cuidado integral em saúde.

Impact of a cholesterol membrane transporter's inhibition on vitamin D absorption: A double-blind randomized placebo-controlled study.

Oral supplements are important to prevent and treat vitamin D deficiency. Despite the growing number of prescriptions, vitamin D's absorptive mechanisms are not clearly elucidated. By evaluating the effect of ezetimibe on vitamin D absorption, we aim to determine if the cholesterol transporter Niemann-Pick C1-Like 1 transporter contributes to it. This randomized, double-blind, placebo-controlled trial (ClinicalTrials.govNCT02234544) was developed in a South Brazilian University Hospital. Fifty-one medical students were randomized to ezetimibe 10mg/day or placebo for 5 days. On the fifth and 19th days, blood samples for 25-hydroxycholecalciferol (25OHD), parathyroid hormone (PTH), calcium, and albumin were collected. After the first blood sample collection, all participants received a single oral 50,000 IU cholecalciferol dose during a 15 g-fat meal. Serum 25OHD levels were measured by the immunoassay Diasorin Liaison®. Measurements were compared in a general linear model adjusted for multiple comparisons by the Bonferroni test. Before cholecalciferol administration, 25OHD was <30 ng/mL and <20 ng/mL, respectively, in all and in 82.3% of the participants. Fourteen days after a single 50,000 IU oral dose of cholecalciferol, mean (SD) changes in serum 25OHD were similar in both groups, after adjustment to BMI and 25OHD levels before cholecalciferol administration (p=0.26): 8.7 (3.7) ng/mL in the ezetimibe group, versus 10.0 (3.8) ng/mL in the placebo group. Mean serum 25OHD, PTH, calcium and albumin levels remained similar in both groups. We conclude that ezetimibe had no effect on the mean change in serum 25OHD after a single oral dose of cholecalciferol, in these healthy and young adults.

Does serum 25-hydroxyvitamin D decrease during acute-phase response? A systematic review.

Low levels of 25-hydroxyvitamin D, or 25(OH)D, are commonly associated with inflammatory diseases. These associations could be due to an increased prevalence of inflammatory diseases in hypovitaminosis D, although reverse causality cannot be excluded. We aimed to systematically review the longitudinal studies that reported serum 25(OH)D during an acute inflammatory response in humans. Using Ovid MEDLINE, EMBASE, and the Cochrane Library, an electronic search of the literature was conducted from database inception until January 2014 by combining the MeSH terms: vitamin D and acute-phase reactants. Other sources for obtaining articles were used as cross-referencing texts. Based on 670 titles and abstracts, 40 articles were selected for full-text review, and 8 of these studies met the final inclusion criteria. In 6 of the reviewed studies, 25(OH)D dropped after the inflammatory insult; this decrease was abrupt in the studies that measured 25(OH)D early after the insult. In 2 studies, there was no change of 25(OH)D during the course of the disease, but baseline levels were measured in both after days of symptoms onset. One study suggested that hemodilution decreased 25(OH)D, with no effect on inflammation. Serum C-reactive protein concentrations were used as inflammatory markers in almost all studies. The metabolic meaning and the functional importance of these changes are unknown. In light of the current evidence, the 25(OH)D measured during acute-phase response should be interpreted with care. Future research, including other markers of vitamin D adequacy, could help to clarify if hypovitaminosis D might be the cause or the consequence of inflammatory diseases.

IGF-I and IGFBP-3 serum levels in patients hospitalized for complications of liver cirrhosis.

BACKGROUND: IGF-I and IGFBP-3 are part of IGF system and, due to their predominantly hepatic synthesis, they seem to correlate with hepatic dysfunction intensity. AIMS: To investigate the significance of IGF-I and IGFBP-3 in patients with decompensated liver disease. MATERIAL AND METHODS: Cross-sectional study that included cirrhotic patients admitted to hospital due to complications of the disease, in whom IGF-I and IGFBP-3 serum levels were measured by chemiluminescence. RESULTS: Seventy-four subjects with a mean age of 53.1 ± 11.6 years were included in the study, 73% were males. IGF-I levels were positively correlated with IGFBP-3 and albumin, and negatively correlated with Child-Pugh, MELD, creatinine, INR and aPTT ratio. IGFBP-3 levels were positively correlated with IGF-I and albumin, and negatively correlated with Child-Pugh, MELD, creatinine, INR, total bilirubin and aPTT ratio. Significantly lower scores of IGF-I and IGFBP-3 were observed in patients with higher MELD values and higher Child-Pugh classes (P < 0.05). CONCLUSIONS: In cirrhotic patients admitted to hospital due to complications of the disease, IGF-I and IGFBP-3 serum levels were associated with variables related to liver dysfunction and to more advanced liver disease. The levels of these markers seem to undergo little influence from other clinical and laboratory variables, therefore mainly reflecting hepatic functional status.