While reduced estrogen levels have been shown to increase bone turnover and induce bone loss, there has been little analysis of the effects of diminished estrogen levels on the lacunar-canalicular porosity that houses the osteocytes. Alterations in the osteocyte lacunar-canalicular microenvironment may affect the osteocyte’s ability to sense and translate mechanical signals, possibly contributing to bone degradation during osteoporosis. To investigate whether reduced estrogen levels affect the osteocyte microenvironment, this study used high-resolution microscopy techniques to assess the lacunar-canalicular microstructure in the rat ovariectomy (OVX) model of postmenopausal osteoporosis. Confocal microscopy analyses indicated that OVX rats had a larger effective lacunar-canalicular porosity surrounding osteocytes in both cortical and cancellous bone from the proximal tibial metaphysis, with little change in cortical bone from the diaphysis or cancellous bone from the epiphysis. The increase in the effective lacunar-canalicular porosity in the tibial metaphysis was not due to changes in osteocyte lacunar density, lacunar size, or the number of canaliculi per lacuna. Instead, the effective canalicular size measured using a small molecular weight tracer was larger in OVX rats compared to controls. Further analysis using scanning and transmission electron microscopy demonstrated that the larger effective canalicular size in the estrogen-deficient state was due to nanostructural matrix-mineral level differences like loose collagen surrounding osteocyte canaliculi. These matrix-mineral differences were also found in osteocyte lacunae in OVX, but the small surface changes did not significantly increase the effective lacunar size. The alterations in the lacunar-canalicular surface mineral or matrix environment appear to make OVX bone tissue more permeable to small molecules, potentially altering interstitial fluid flow around osteocytes during mechanical loading.

Multiple myeloma (MM) is the second most common hematologic malignancy and the most common malignancy to involve bone. More than 85% of patients with MM have bone involvement, which can be devastating. Bisphosphonate therapy is the mainstay of treatment for MM bone disease; it has decreased the frequency of skeletal events in MM and delayed their development. Further, the toxicity of these drugs is low and generally manageable. Whether bisphosphonates have any antitumor effects in MM patients (in contrast to what has been reported in preclinical models) is unclear and requires further study. Although bisphosphonates have been extremely effective for treating MM bone disease, they do not completely inhibit the development of skeletal events, but only decrease them significantly. Other antiresorptive agents now being developed may further enhance the quality of life for MM patients when used in combination with bisphosphonates.

Abstract. Background and aims: Magnesium plays a key role in glucose metabolism, vascular tone, and inflammation. Therefore, it might be a dietary risk factor for cardiovascular diseases. In vitro and animal studies have suggested a decrease in vascular calcification with an increase in the magnesium intake. The objective of the present study was to investigate the association between magnesium intake and coronary artery calcium (CAC) score among participants of the ELSA-Brasil. Methods: This is an observational, cross-sectional study undertaken with a sub-sample from the ELSA-Brasil baseline data. In this sub-sample, only participants with CAC examination data were included (n = 4,306). Dietary intake was assessed by a validated food frequency questionnaire. The association between magnesium intake and presence of CAC (0 versus > 0) was investigated using multiple logistic regression models. Results: The participants were predominantly female (54.4 %), with self-reported white skin color (59.1 %), no smoking habit (53.7 %) and undergraduate or postgraduate education (44.4 %). The range of magnesium consumption was 37.24 – 1266.31 mg/day. CAC prevalence was 28.4 %. No significant association was found between magnesium intake and CAC after adjustments for diet, lifestyle, and clinical characteristics. In a first univariate model, the fifth quintile of magnesium intake, in comparison to the first quintile (lowest intake), resulted in an OR = 1.25, 95 % CI: 1.01 – 1.54 ( P-linear trend = 0.005). However, in the last fully adjusted model, the fifth quintile of magnesium intake resulted in OR = 0.86, 95 % CI: 0.64 – 1.17 ( P-linear trend = 0.239). Conclusions: In ELSA-Brasil, the intake of magnesium was not associated with the presence of coronary artery calcification.

Existing methods for assessing food consumption are subject to measurement errors, especially the underreporting of energy intake, characterized by reporting energy intake below the minimum necessary to maintain body weight. This study aimed to compare the identification of energy intake underreporters using different predictive equations and instruments to collect dietary data. The study was conducted with 101 selected participants in the third wave of the Longitudinal Study of Adult Health (ELSA-Brasil) at the University Hospital of the University of São Paulo. For the dietary assessment, we applied a food frequency questionnaire (FFQ), two 24-hour diet recall (24hR) using the GloboDiet software, and two 24hR using the Brasil-Nutri software. The energy intake underreport obtained from the FFQ was 13%, 16%, and 1% using the equations proposed by Goldberg et al. (1991), Black (2000), and McCrory et al. (2002), respectively. With these same equations, the 24hR described an underreport of 9.9%, 14.9%, and 0.9% respectively with the GloboDiet software and 14.7%, 15.8%, and 1.1% respectively with the Brasil-Nutri software. We verified a low prevalence of underreported energy intake among the three self-report-based dietary data collection methods (FFQ, 24hR with GloboDiet, and Brasil-Nutri). Though no statistically significant differences were found among three methods, the equations for each method differed among them. The agreement of energy intake between the methods was very similar, but the best was between GloboDiet and Brasil-Nutri.

Background: Coronary Artery Calcification (CAC) is considered an important cardiovascular risk factor. There is evidence that CAC is associated with an increased risk of atherosclerosis, coronary events and cardiovascular mortality. Inflammation is one of the factors associated with CAC and despite the interest in antioxidant compounds that can prevent CAC, its association with antioxidants remains unclear. Objective: This study aimed to systematically review the association between vitamins and minerals with antioxidant effects and CAC in adults and older adults. Methods: We conducted a systematic review using PubMed for articles published until October 2018. We included studies conducted in subjects aged 18 years and older with no previous cardiovascular disease. Studies involving animal or in vitro experiments and the ones that did not use reference methods to assess the CAC, dietary intake or serum levels of vitamin or mineral were excluded. Results: The search yielded 390 articles. After removal of duplicates, articles not related to the review, review articles, editorials, hypothesis articles and application of the inclusion and exclusion criteria, 9 articles remained. The results of the studies included in this systematic review suggest that magnesium is inversely associated with CAC and results on the association between CAC and vitamin E have been conflicting. Conclusion: Additional prospective studies are needed to elucidate the role of these micronutrients on CAC.

The yellow color of 9,IO-phenanthrenequinone in alcohol solution is bleached under the influence of exciting radiation in a band of wavelengths extending from the ultraviolet to the visible green. The bleaching is due to a photoreduction of the quinone yielding 9,lOdihydroxyphenanthrene. In the presence of certain divalent metal ions, irradiation of the quinoid material results in a blue-green long lived intermediate which may be further photoreduced to the colorless 9.1 0-diol. The blue-green photo-intermediate is a cation-semiquinone complex.

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