Cut-off values of distal forearm bone density for the diagnosis of central osteoporosis in black postmenopausal South African women

Background: The objective of this study was to establish a triage cut-off point or threshold for peripheral bone mineral density (BMD), applicable to black postmenopausal women, and that could be used as a screening method to differentiate between women with normal BMD, and those with possible central osteoporosis. This was a cross-sectional study design conducted in the North West province. Central and peripheral BMD was measured in 184 black, urban postmenopausal women.Method: Receiver operating curves (ROC) analysis was used to establish cut-off points. Sensitivity, specificity, positive and negative predictive value, odds ratios and likelihood ratios were determined.Results: The results showed a prevalence rate of 41.3% for central osteoporosis. The area under the curve (AUC) for osteoporosis at the hip was 0.818, and for the spine, it was 0.771. Using the optimum cut-off point (0.371 g/cm2), our results showed a misclassification rate of ≈ 49% for spine osteoporosis, and a negative predictive value of 0.825. Women who had a forearm BMD below this threshold were ~10 times more likely to have osteoporosis of the spine.Conclusion: We recommend using 0.371 g/cm2 as a cut-off point to differentiate between women who have normal BMD, and those with possible osteoporosis of the spine

Correlation between body condition score and body composition in a rat model for obesity research

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Body composition and intake of nutrients associated with bone metabolism in young adolescents in a peri-urban setting

Objective: The aim was to describe the anthropometry, bone mineral content (BMC), bone mineral density (BMD), dietary calcium intake and 25(OH)D3 levels in 11- and 12-year-old children in a peri-urban area. Design: A cross-sectional, descriptive study in the quantitative domain was undertaken. Setting: Bronkhorstspruit, Gauteng, South Africa. Subjects: Children, conveniently selected, were assessed in two groups. The first group comprised 70 children. From the 70 children, 20 children were conveniently selected to form a sub-sample (n = 20). Outcome measures: Anthropometric data (weight, height) and dietary data (three quantified /multi-pass 24-hour recalls). Children in the sub-sample additionally underwent body composition assessment (dual-energy X-ray absorptiometry; DXA scan) and a finger prick for 25(OH)D3. Results: BMI and body composition data (body fat mass and lean fat mass) showed that the girls exceeded the boys in all measurements. The girls had a non-significantly higher BMD and BMC than the boys. The mean and median values for 25(OH)D3 were lower than the reference range values. Dietary intake results showed that the children had a sufficient macronutrient intake, but a deficient intake of calcium, phosphate and vitamin D. The sub-sample had a mean vitamin D intake of 3.2 mcg. Conclusion: The girls exceeded the boys in all the anthropometric and body composition measurements. The calcium and vitamin D intake of the children were of concern. There were no significant differences or relationships in the bone measurements and vitamin D status between the boys and girls

Folate and Vitamin B-12 Status Is Associated With Bone Mineral Density and Hip Strength of Postmenopausal Chinese-Singaporean Women

The role of micronutrients such as folate and vitamin B-12 in bone quality has been widely studied with conflicting results. Ethnicity seems to play a large role on nutrient intake, as diet varies across cultures. In this study, we examined the relationships of BMD, proximal femur strength, and bone resorption with plasma folate and vitamin B-12 in a cohort of 93 healthy postmenopausal women of Chinese-Singaporean descent. The parameters examined were areal (aBMD) and volumetric BMD (vBMD) of the proximal femur and the third lumbar vertebra (L3), total body aBMD, proximal femur bending, compressive and impact strength indices (composite strength indices) and circulating levels of C-telopeptide of type I collagen. Eighteen participants (19.4%) had aBMD in the osteoporotic range (osteoporosis group), 59 (63.4%) in the osteopenic range (osteopenia group), and the remaining 16 (17.2%) in the normal range (normal BMD group). Circulating folate levels were significantly higher in the normal BMD group compared with the osteoporosis group. Using linear regression analysis, we found that overall, aBMD and vBMD are positively associated with folate concentrations, whereas composite strength indices were positively associated with vitamin B-12 concentrations. These findings support the existing literature and suggest a link between levels of circulating folate/vitamin B-12 and BMD/bone strength in the cohort examined. Further investigation is needed to examine if individuals with inadequate circulating levels of these nutrients could decrease their risk for fragility fractures through better nutrition or vitamin supplementation. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research

Urinary peptidomics and pulse wave velocity: The African-PREDICT study

Increased arterial stiffness is related to early vascular aging and is an independent predictor for cardiovascular disease and mortality. Molecular mechanisms underlying increased arterial stiffness are largely unexplored, especially at the proteome level. We aimed to explore the relationship between pulse wave velocity and urinary proteomics. We included 919 apparently healthy (no chronic illnesses) Black and White men and women (equally distributed) between 20 and 30 years from the African-PREDICT study. Capillary electrophoresis time-of-flight mass spectrometry was used to analyze the urinary proteome. We measured the carotid-femoral pulse wave velocity to estimate arterial stiffness. In the total group, pulse wave velocity correlated positively with collagen-derived peptides including collagen types I, II, III, IV, V, and IX and inversely with collagen type XI (adjusted for mean arterial pressure). Regarding noncollagen-derived peptides, pulse wave velocity positively correlated with polymeric immunoglobulin receptor peptides (n = 2) (all q-value ≤0.05). In multivariable adjusted analyses, pulse wave velocity associated positively and independently with seven urinary peptides (collagen type I, n = 5) (all p-value ≤0.05). We found significant positive and independent associations between pulse wave velocity and the collagen type I-derived peptides, suggesting that dysregulation of collagen type I in the extracellular matrix scaffold could lead to early onset of increased arterial stiffness

Mycobacterium tuberculosis ClpP Proteases Are Co-transcribed but Exhibit Different Substrate Specificities

PMCID: PMC3613350This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Improved Immunodetection of Endogenous α-Synuclein

α-Synuclein is a key molecule in understanding the pathogenesis of neurodegenerative α-synucleinopathies such as Parkinson's disease. Despite extensive research, however, its precise function remains unclear partly because of a difficulty in immunoblotting detection of endogenous α-synuclein. This difficulty has largely restricted the progress for α-synucleinopathy research. Here, we report that α-synuclein monomers tend to easily detach from blotted membranes, resulting in no or very poor detection. To prevent this detachment, a mild fixation of blotted membranes with paraformaldehyde was applied to the immunoblotting method. Amazingly, this fixation led to clear and strong detection of endogenous α-synuclein, which has been undetectable by a conventional immunoblotting method. Specifically, we were able to detect endogenous α-synuclein in various human cell lines, including SH-SY5Y, HEK293, HL60, HeLa, K562, A375, and Daoy, and a mouse cell line B16 as well as in several mouse tissues such as the spleen and kidney. Moreover, it should be noted that we could clearly detect endogenous α-synuclein phosphorylated at Ser-129 in several human cell lines. Thus, in some tissues and cultured cells, endogenous α-synuclein becomes easily detectable by simply fixing the blotted membranes. This improved immunoblotting method will allow us to detect previously undetectable endogenous α-synuclein, thereby facilitating α-synuclein research

Deep-Inelastic Inclusive ep Scattering at Low x and a Determination of alpha_s

A precise measurement of the inclusive deep-inelastic e^+p scattering cross section is reported in the kinematic range 1.5<= Q^2 <=150 GeV^2 and 3*10^(-5)<= x <=0.2. The data were recorded with the H1 detector at HERA in 1996 and 1997, and correspond to an integrated luminosity of 20 pb^(-1). The double differential cross section, from which the proton structure function F_2(x,Q^2) and the longitudinal structure function F_L(x,Q^2) are extracted, is measured with typically 1% statistical and 3% systematic uncertainties. The measured partial derivative (dF_2(x,Q^2)/dln Q^2)_x is observed to rise continuously towards small x for fixed Q^2. The cross section data are combined with published H1 measurements at high Q^2 for a next-to-leading order DGLAP QCD analysis.The H1 data determine the gluon momentum distribution in the range 3*10^(-4)<= x <=0.1 to within an experimental accuracy of about 3% for Q^2 =20 GeV^2. A fit of the H1 measurements and the mu p data of the BCDMS collaboration allows the strong coupling constant alpha_s and the gluon distribution to be simultaneously determined. A value of alpha _s(M_Z^2)=0.1150+-0.0017 (exp) +0.0009-0.0005 (model) is obtained in NLO, with an additional theoretical uncertainty of about +-0.005, mainly due to the uncertainty of the renormalisation scale.Comment: 68 pages, 24 figures and 18 table

A novel synthesis and detection method for cap-associated adenosine modifications in mouse mRNA

A method is described for the detection of certain nucleotide modifications adjacent to the 5' 7-methyl guanosine cap of mRNAs from individual genes. The method quantitatively measures the relative abundance of 2'-O-methyl and N6,2'-O-dimethyladenosine, two of the most common modifications. In order to identify and quantitatify the amounts of N6,2'-O-dimethyladenosine, a novel method for the synthesis of modified adenosine phosphoramidites was developed. This method is a one step synthesis and the product can directly be used for the production of N6,2'-O-dimethyladenosine containing RNA oligonucleotides. The nature of the cap-adjacent nucleotides were shown to be characteristic for mRNAs from individual genes transcribed in liver and testis