944 resultados para 25-hydroxyvitamine-D


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Evidence for the presence of the vitamin D receptor in brain implies this vitamin may have some function in this organ. This study investigates whether vitamin D-3 acts during brain development. We demonstrate that rats born to vitamin D-3-deficient mothers had profound alterations in the brain at birth. The cortex was longer but not wider, the lateral ventricles were enlarged, the cortex was proportionally thinner and there was more cell proliferation throughout the brain. There were reductions in brain content of nerve growth factor and glial cell line-derived neurotrophic factor and reduced expression of p75(NTR), the low-affinity neurotrophin receptor. Our findings would suggest that low maternal vitamin D3 has important ramifications for the developing brain. (C) 2003 IBRO. Published by Elsevier Science Ltd. All rights reserved.

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Background - Specific treatments targeting the pathophysiology of hypertensive heart disease are lacking. As aldosterone has been implicated in the genesis of myocardial fibrosis, hypertrophy, and dysfunction, we sought to determine the effects of aldosterone antagonism on myocardial function in hypertensive patients with suspected diastolic heart failure by using sensitive quantitative echocardiographic techniques in a randomized, double-blinded, placebo-controlled study. Methods and Results - Thirty medically treated ambulatory hypertensive patients (19 women, age 62 +/- 6 years) with exertional dyspnea, ejection fraction >50%, and diastolic dysfunction (E/A 250m/sec) and without ischemia were randomized to spironolactone 25 mg/d or placebo for 6 months. Patients were overweight (31 +/- 5 kg/m(2)) with reduced treadmill exercise capacity (6.7 +/- 2.1 METS). Long-axis strain rate (SR), peak systolic strain, and cyclic variation of integrated backscatter (CVIB) were averaged from 6 walls in 3 standard apical views. Mean 24-hour ambulatory blood pressure at baseline (133 +/- 17/80 +/- 7mm Hg) did not change in either group. Values for SR, peak systolic strain, and CVIB were similar between groups at baseline and remained unchanged with placebo. Spironolactone therapy was associated with increases in SR (baseline: -1.57 +/- 0.46 s(-1) versus 6-months: -1.91 +/- 0.36 s(-1), P < 0.01), peak systolic strain (-20.3 &PLUSMN; 5.0% versus -26.9 &PLUSMN; 4.3%, P < 0.001), and CVIB (7.4 +/- 1.7dB versus 8.6 +/- 1.7 dB, P = 0.08). Each parameter was significantly greater in the spironolactone group compared with placebo at 6 months (P = 0.05, P = 0.02, and P = 0.02, respectively), and the increases remained significant after adjusting for baseline differences. The increase in strain was independent of changes in blood pressure with intervention. The spironolactone group also exhibited reduction in posterior wall thickness (P = 0.04) and a trend to reduced left atrial area (P = 0.09). Conclusions - Aldosterone antagonism improves myocardial function in hypertensive heart disease.

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Growth hormone (GH) regulates many of the factors responsible for controlling the development of bone marrow progenitor cells (BMPCs). The aim of this study was to elucidate the role of GH in osteogenic differentiation of BMPCs using GH receptor null mice (GHRKO). BMPCs from GHRKO and their wild-type (WT) littermates were quantified by flow cytometry and their osteogenic differentiation in vitro was determined by cell morphology, real-time RT-PCR, and biochemical analyses. We found that freshly harvested GHRKO marrow contains 3% CD34 (hernatopoietic lineage), 43.5% CD45 (monocyte/macrophage lineage), and 2.5% CD106 positive (CFU-F/BMPC) cells compared to 11.2%, 45%, and 3.4% positive cells for (WT) marrow cells, respectively. When cultured for 14 days under conditions suitable for CFU-F expansion, GHRKO marrow cells lost CD34 positivity, and were markedly reduced for CD45, but 3- to 4-fold higher for CD106. While WT marrow cells also lost CD34 expression, they maintained CD45 and increased CD106 levels by 16-fold. When BMPCs from GHRKO mice were cultured under osteogenic conditions, they failed to elongate, in contrast to WT cells. Furthermore, GHRKO cultures expressed less alkaline phosphatase, contained less mineralized calcium, and displayed lower osteocalcin expression than WT cells. However, GHRKO cells displayed similar or higher expression of cbfa-1, collagen 1, and osteopontin mRNA compared to WT. In conclusion, we show that GH has an effect on the proportions of hematopoietic and mesenchymal progenitor cells in the bone marrow, and that GH is essential for both the induction and later progression of osteogenesis. (c) 2005 Elsevier Inc. All rights reserved.

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We have observed that vitamin A levels, deficient in patients with severe disease, returned to normal post lungtransplant independent of oral supplementation or pancreatic sufficiency. We hypothesised that vitamin A is associated with disease severity and the inflammatory marker C-related peptide (CRP). Data from RCH paediatric and TPCH adult CF clinic subjects (ns138 CF, 138 control, aged 5–56 yr), who had participated in a study of bone mineral density (BMD) in which vitamins A, E, D, and CRP, height, weight and lung function had been measured was used. Groups were compared using t- or Wilcoxon-tests, and predictors of vitamin A examined usingmultiple regression. Vitamin A was lower in CF subjects (1.23"0.5 vs. 1.80"0.6 mmolyl, P-0.0001), increasingwith age in paediatric subjects but to a lesser extent in the CF group (Ps0.0007). CRP was correlated with age (rs0.6, P-0.0001). FEV1% predicted (FEV) (57.93"23.0 vs. 70.63"21.8, Ps0.0014), weight z-score (WTZ) (y0.76"0.9 vs. y0.12"1.0, Ps0.0002), lumbar spine BMD z-score (y1.08"1.3 vs. y0.50"1.2, Ps0.009) were lower, and CRP higher (median 7.0, IQR 2–4 vs. median 1.0, IQR 1–3 mgy l, P-0.0001) in vitamin A insufficient CF subjects (61 insufficient vs. 71 sufficient). In all subjects, control status (P-0.0001), WTZ (Ps0.02), vitamin E (Ps 0.0003), CRP (Ps0.001), 1,25 dihydroxy vitamin D (1,25 vit. D) (Ps0.0007), and child, adolescent or adult grouping (all P-0.0001) were predictive of vitamin A. In the CF group, CRP (Ps0.01), Vitamin E (P-0.0001) and 1.25 vit. D (Ps 0.006), but not FEV, were predictive. The normal increase in vitamin A with age was not observed in CF subjects, who had lower levels at any age. This failure of normal increase in vitamin A had a consistent association with increasingCRP , supportingthe hypothesis that increased inflammation may result in increased vitamin A consumption.

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Epidemiological evidence suggests that diets rich in fruits, vegetables and pulses reduce the risk of CVD. The Physicians Health Study has demonstrated reduction of CHD death with regular nut consumption1. One major modifiable risk factor for CHD is an unhealthy diet. Thus, an almondenrichment study has been undertaken to examine the benefit of almonds (Prunus amygdalis) in healthy individuals either with or without significant risk of vascular disease. Almonds contain various macronutrients (low SFA content, absence of cholesterol and high MUFA content) and micronutrients, including vitamin E, polyphenols and arginine, which afford vascular benefit. The effects of almond consumption (25 g/d for 4 weeks followed by 50 g/d for 4 weeks) were evaluated in three non-smoking subject groups: healthy male volunteers between the ages of 18 and 35 years (n 15); men at risk of heart disease between the ages of 18 and 35 years (n 12); mature men and women >50 years of age (n 18). A fourth control group (n 14) were followed over 8 weeks without dietary almond enrichment as a treatment control. None of the subjects withdrew from the study and 90% completed the study. The interim results of the study showed that in the three active groups there was little evidence for a change in total cholesterol, LDL-cholesterol or HDL-cholesterol. In the mature group there was a trend towards increasing HDL-cholesterol. The mature and ‘at-risk’ groups also showed a significant changes in systolic blood pressure (P<0.05) during almond consumption. The healthy group showed a decrease in diastolic blood pressure (P<0.05). The ‘at-risk’ group showed a significant increase (P<0.05) in flowmediated dilation after 8 weeks of almond consumption. Data analysis is ongoing, with completion of the study in November 2007. The beneficial effects of almond consumption on flow-mediated dilation and blood pressure may be attributed to the high content in almonds of arginine, which serves as a precursor to the vasodilatory molecule, NO.

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Purpose: A retrospective study of longitudinal case histories, undertaken to establish the clinical and statistical characteristics of unilateral myopic anisometropia (UMA) amongst the juvenile and adolescent population at an optometric practice, is reported. UMA was defined as that specific refractive state where an unequivocally myopic eye is paired with a 'piano' [spherical equivalent refraction, (SER) = ±0.25 Dioptres (D)] companion eye. Methods: The clinical records of all patients aged <19 years on file at an established independent optometric practice were categorised as 'myopic' (SER ≤-0.50 D), 'hypermetropie' (≥+0.75 D) or 'emmetropic' (≥-0.37≤+0.62 D). Subsequently all juvenile patients matching the UMA criterion, together with a case-matched group of bilaterally myopic individuals, were selected as the comparative study populations. Results: A total of 14.4% (n = 21 of 146) of the juvenile myopic case histories were identified as cases of UMA. More than half of these UMA cases emerged between the ages of 11.5 and 13.5 years. There was a marked female gender bias. The linear gradient of the age-related mean refractive trend in the myopic eye of the UMA population was not statistically significantly different (p > 0.1) to that fitted to the ametropic progression recorded in either eye of the case-matched population of young bilateral myopes; uniquely the slope associated with the companion eye of UMA cases was statistically significantly (p < 0.025) less steep. Compared with bilateral myopes fewer cases of UMA required a refractive correction to relieve visual or asthenopic symptoms, and this initial correction was dispensed on average 1 year later (at age 12.7 years) in UMA patients. Conclusions: Individuals identified as demonstrating clinically-defined UMA can be considered as distinct but functionally normal cases on the continuum of human refractive error. However, any unilaterally-acting determining factor(s) underlying the genesis of the condition remain obscure. © 2004 The College of Optometrists.

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PURPOSE: To validate a new miniaturised, open-field wavefront device which has been developed with the capacity to be attached to an ophthalmic surgical microscope or slit-lamp. SETTING: Solihull Hospital and Aston University, Birmingham, UK DESIGN: Comparative non-interventional study. METHODS: The dynamic range of the Aston Aberrometer was assessed using a calibrated model eye. The validity of the Aston Aberrometer was compared to a conventional desk mounted Shack-Hartmann aberrometer (Topcon KR1W) by measuring the refractive error and higher order aberrations of 75 dilated eyes with both instruments in random order. The Aston Aberrometer measurements were repeated five times to assess intra-session repeatability. Data was converted to vector form for analysis. RESULTS: The Aston Aberrometer had a large dynamic range of at least +21.0 D to -25.0 D. It gave similar measurements to a conventional aberrometer for mean spherical equivalent (mean difference ± 95% confidence interval: 0.02 ± 0.49D; correlation: r=0.995, p<0.001), astigmatic components (J0: 0.02 ± 0.15D; r=0.977, p<0.001; J45: 0.03 ± 0.28; r=0.666, p<0.001) and higher order aberrations RMS (0.02 ± 0.20D; r=0.620, p<0.001). Intraclass correlation coefficient assessments of intra-sessional repeatability for the Aston Aberrometer were excellent (spherical equivalent =1.000, p<0.001; astigmatic components J0 =0.998, p<0.001, J45=0.980, p<0.01; higher order aberrations RMS =0.961, p<0.001). CONCLUSIONS: The Aston Aberrometer gives valid and repeatable measures of refractive error and higher order aberrations over a large range. As it is able to measure continuously, it can provide direct feedback to surgeons during intraocular lens implantations and corneal surgery as to the optical status of the visual system.

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Mathematics Subject Classification: 43A20, 26A33 (main), 44A10, 44A15

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Poster Purpose: A study to validate a prototype Hartmann-Shack (HS) wavefront aberrometer. Methods: The dynamic range was assessed using a calibrated model eye. It was validated against a conventional HS-aberrometer (Topcon KR1W) in 75 eyes using both instruments in random order. Additionally, intra-sessional repeatability was tested. Results: The aberrometer showed a large dynamic range of +21.0 D to −25.0 D. It was comparable to a conventional HS aberrometer for spherical-equivalent SE (MD ± 95% CI: 0.02 ± 0.49D; correlation: r = 0.995, p < 0.001), astigmatic components (J0: 0.02 ± 0.15D; r = 0.977, p < 0.001; J45: 0.03 ± 0.28; r = 0.666, p < 0.001) and HOAs RMS (0.02 ± 0.20D; r = 0.620, p < 0.001). Intra-sessional repeatability correlation was also excellent (SE = 1.000, p < 0.001; astigmatic-components J0 = 0.998, p < 0.001, J45 = 0.980, p < 0.01; HOAs RMS = 0.961, p < 0.001). Conclusions: This study confirms the validity of the prototype aberrometer. The prototype aberrometer can measure continuously to provide direct feedback of the optical status of the eye during surgery.

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The cross sectional study investigated the association of tobacco smoke, vitamin D status, anthropometric parameters, and kidney function in Turkish immigrants with type 2 diabetes (T2D) living in the Netherlands. Study sample included a total of 110 participants aged 30 years and older (males= 46; females= 64). Serum cotinine, a biomarker for smoke exposure, was measured with a solid-phase competitive chemiluminescent immunoassay. Serum 25-hydroxyvitamin D [25(OH)D] was determined by electrochemiluminescence immunoassay (ECLIA). Measures of obesity including: body weight, body mass index (BMI), waist circumference (WC), and hip circumference (HC) were measured. Waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) were calculated. Urine albumin was measured by immunoturbidimetric assay. Urine creatinine was determined using the Jaffe method. All statistical analyses were performed using SPSS, version 19.0 (SPSS Inc., Chicago, IL, USA). Independent samples t-test, chi-squared tests, multiple linear regression and logistic regression analysis were used. Cotinine levels were positively associated with cholesterol to HDL ratio and atherosclerosis-index. Serum 25(OH)D levels were negatively associated with diastolic blood pressure. Gender-specific associations between anthropometric measures and high sensitivity C-reactive protein (hs-CRP) levels were observed. Hs-CRP was positively associated with WC and WHR in males and WHtR in females. Microalbuminuria (MAU), as determined by albumin-to-creatinine ratio, was present in 21% of the Turkish immigrants with T2D. Participants with hypertension were 6.58 times more likely (adjusted odds ratio) to have positive MAU as compared to normotensive participants. Our findings indicate that serum cotinine, 25(OH)D, hs-CRP, and MAU may be assessed as a standard of care for T2D management in the Turkish immigrant population. Further research should be conducted following cohorts to determine the effects of these biomarkers on CVD morbidity and mortality.

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