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Osteoporosis: HELP
Articles by Angela Xuereb-Anastasi
Based on 3 articles published since 2008
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Between 2008 and 2019, Angela Xuereb-Anastasi wrote the following 3 articles about Osteoporosis.
 
+ Citations + Abstracts
1 Article Biochemical Predictors of Low Bone Mineral Density and Fracture Susceptibility in Maltese Postmenopausal Women. 2016

Formosa, Melissa M / Xuereb-Anastasi, Angela. ·Department of Applied Biomedical Science, Faculty of Health Sciences, Block A, Level 1, Mater Dei Hospital, University of Malta, Msida, MSD 2080, Malta. melissa.m.formosa@um.edu.mt. · Department of Applied Biomedical Science, Faculty of Health Sciences, Block A, Level 1, Mater Dei Hospital, University of Malta, Msida, MSD 2080, Malta. ·Calcif Tissue Int · Pubmed #26400554.

ABSTRACT: Osteoporosis and fractures are complex conditions influenced by an interplay of genetic and environmental factors. The aim of the study was to investigate three biochemical parameters including total serum calcium, total serum alkaline phosphatase (sALP) and albumin in relation to bone mineral density (BMD) at the lumbar spine and femoral neck (FN), and with all-type of low-trauma fractures in Maltese postmenopausal women. Levels were also correlated with age and physical activity. A case-control study of 1045 women was performed. Women who suffered a fracture were classified as cases whereas women without a fracture history were included as controls subdivided into normal, osteopenic, or osteoporotic according to their BMD measurements. Blood specimens were collected following good standard practice and testing was performed by spectrophotometry. Calcium and sALP levels were weakly correlated with FN BMD levels (calcium: r = -0.111, p = 0.002; sALP: r = 0.089, p = 0.013). Fracture cases had the lowest serum levels of calcium, sALP and albumin relative to all other control groups, which decreased with increasing age, possibly increasing fracture risk. Biochemical levels were lowest in women who sustained a hip fracture and more than one fracture. Biochemical parameters decreased with reduced physical activity; however, this was most evident for fracture cases. Reduced physical activity was associated with lower BMD levels at the hip, and to a lower extent at the spine. In conclusion, results suggest that levels of serum calcium and albumin could be indicative of fracture risk, whereas calcium levels and to lower extent sALP levels could be indicators of hip BMD.

2 Article Functional polymorphisms within the TNFRSF11B (osteoprotegerin) gene increase the risk for low bone mineral density. 2011

Vidal, Christopher / Formosa, Robert / Xuereb-Anastasi, Angela. ·DNA Laboratory, Department of Applied Biomedical Science, Faculty of Health Sciences Department of Pathology, Faculty of Medicine and Surgery, University of Malta, Msida, Malta. ·J Mol Endocrinol · Pubmed #21994215.

ABSTRACT: Polymorphisms within the TNFRSF11B gene have been studied and associated with osteoporosis and fracture risk. Osteoprotegerin (OPG), the product of this gene, is a key negative regulator of osteoclastogenesis and is secreted by osteoblasts/stromal cells. A previous study in Maltese postmenopausal women showed positive association of low bone mineral density (BMD) with a polymorphism found within the promoter region of this gene (C950T). In this study, direct DNA sequencing revealed 12 variants with polymorphisms C950T, G1181C and rs4876869 observed to be in strong linkage disequilibrium. The constructed haplotype T-G-T was found to increase the risk for a low BMD, while C-G-T and C-C-C have a protective role; thus, we investigated the functional role of both C950T and rs4876869 in vitro. The promoter region, including the C950T alleles, was amplified by PCR, cloned into pGL3 enhancer vector and transfected into HeLa, COS-7 and RAW264.7 cell lines. After incubation, luciferase activity was measured. The T/C (rs4876869) change was tested for its possible effect on pre-mRNA splicing, using an exon-trapping vector. A statistical significant difference in gene expression was observed between the alleles for T950C, with the T allele showing a lower luciferase expression in all cell lines (P<0.01). For rs4876869, exon skipping was observed for the C allele, while only one transcript harbouring the whole exon was observed for the T allele. Our findings suggest that the T-G-T haplotype might be increasing the risk for osteoporosis due to lower quantities of the full OPG transcript being expressed resulting in a higher bone resorption.

3 Article Effects of a synonymous variant in exon 9 of the CD44 gene on pre-mRNA splicing in a family with osteoporosis. 2009

Vidal, Christopher / Cachia, Adela / Xuereb-Anastasi, Angela. ·Department of Pathology, University of Malta, Medical School, G'Mangia, Malta. ·Bone · Pubmed #19580891.

ABSTRACT: In a previous linkage study, suggestive linkage to osteoporosis was observed in marker D11S1392 on chromosome 11p12. The CD44 gene, found at this locus, was sequenced in one of the families studied. Sequencing all coding regions and promoter in affected and non-affected family members revealed a number of sequence variants, one of which was found to be linked and inherited identical by descent together with the linked STR allele. This G to A variant, which does not cause an amino acid change, was found in exon 9 of the CD44 gene, 32 base pairs upstream from the exon-intron junction. Preliminary analysis using a bioinformatics tool suggested that the presence of the A allele abolished an exon splicing enhancer (ESE) site, thus possibly affecting RNA splicing. It was observed using an exon-trapping vector, that in the presence of the A allele, only one transcript was observed in RAW264.7 cells, as opposed to two transcripts transcribed in the presence of the G allele. These observations suggest that the linked synonymous variant found in exon 9 of the CD44 gene might be increasing susceptibility to osteoporosis in this family by affecting the splicing mechanism.