1,668 research outputs found
Serum, Saliva, and Gingival Crevicular Fluid Osteocalcin: Their Relation to Periodontal Status and Bone Mineral Density in Postmenopausal Women
Background: Periodontitis and osteoporosis are characterized by the loss of bone mass. Osteocalcin levels have been postulated as a marker of inhibition of bone formation. The aim of the present study was to assess plasma, saliva, and gingival
crevicular fluid (GCF) levels of osteocalcin and correlate them with periodontitis and osteoporosis.
Methods: Seventy-three postmenopausal women, over 35 years old, were recruited for the study. Serum, saliva, and GCF osteocalcin were measured. Vertebral bone mineral density was measured by dual-energy x-ray absorptiometry. Differences between groups were assessed by analysis of variance (ANOVA), chi-square test, and non-parametric Kruskal-Wallis test.
Results: Thirty-four (46.6%) were classified in the normal healthy bone group, 11 women (15.1%) in the osteopenic group,
and 28 women (38.4%) in the osteoporotic group. No statistically significant differences between these densitometric groups were observed in probing depth (P = 0.24); clinical attachment level (P = 0.11); or mean osteocalcin concentrations in serum, saliva, and GCF. Twenty-seven (37.0%) of the women were classified without periodontitis (NPG) and 63.0% (N = 46) with periodontal disease (PG). There were no statistical differences in serum and saliva osteocalcin concentrations between these two groups. GCF osteocalcin concentrations were significantly higher in the PG women than in the NPG group (P = 0.008). Mean probing depth correlated significantly with GCF osteocalcin concentrations (r = 0.35; P = 0.002).
Conclusion: The results further support the concept that osteocalcin levels in GCF correlates with periodontal but not with
osteoporosis status
Identification of an osteocalcin isoform in fish with a large acidic prodomain
Osteocalcin is a small, secreted bone protein whose gene consists of four exons. In the course of analyzing the structure of fish osteocalcin genes, we recently found that the spotted green pufferfish has two possible exon 2 structures, one of 15 bp and the other of 324 bp. Subsequent analysis of the pufferfish cDNA showed that only the transcript with a large exon 2 exists. Exon 2 codes for the osteocalcin propeptide, and exon 2 of pufferfish osteocalcin is ∼3.4-fold larger than exon 2 previously found in other vertebrate species. We have termed this new pufferfish osteocalcin isoform OC2. Additional studies showed that the OC2 isoform is restricted to a unique fish taxonomic group, the Osteichthyes; OC2 is the only osteocalcin isoform found so far in six Osteichthyes species, whereas both OC1 and OC2 isoforms coexist in zebrafish and rainbow trout. The larger size of the OC2 propeptide is due to an acidic region that is likely to be highly phosphorylated and has no counterpart in the OC1 propeptide. We propose 1) that OC1 and OC2 are encoded by distinct genes that originated from a duplication event that probably occurred in the teleost fish lineage soon after divergence from tetrapods and 2) that the novel OC2 propeptide could be, if secreted, a phosphoprotein that participates in the regulation of biomineralization through its large acidic and phosphorylated propeptide
Mesenchymal Differentiation and Organ Distribution of Established Human Stromal Cell Lines in NOD/SCID Mice
Two human stromal cell lines were established previously from bone marrow-derived primary long-term cultures by immortalization using the SV40 large T antigen and cellular cloning. After irradiation, the fibroblast-like cell lines L87/4 and L88/5 support hematopoietic differentiation of allogeneic cord blood cells in vitro. The stromal cells do not express CD34 and CD50, but some adhesion molecules and integrins, such as CD44, CD54 and CD58. Their expression profiles on RNA and protein levels are suggestive of their osteogenic potency. The quality and quantity of osteocalcin and osteopontin protein expression depended on the culture conditions. Expression of the osteogenic markers increased over time in culture, especially in cells growing in clusters. The stromal cells also expressed collagens I and V, but did not show any expression of collagens II and III. The potentially osteoblastic stromal cells were transplanted into NOD/SCID recipient mice by intravenous injection and were found in various mesenchymal organs up to 10 weeks after transplantation. Osteocalcin-positive human stromal cells could be detected in the bone marrow, thymus, liver, brain and gut of the recipient animals. In summary, there is evidence that human bone-marrow-derived stromal cells have to be considered mesenchymal progenitors, persistently expressing osteogenic markers in vitro and in vivo. Copyright (C) 2001 S, Karger AG, Basel
Factors Affecting Attribution: The Burlington Glass Works
L'exploitation tardive de l'industrie du verre au Canada, l'influence des verriers étrangers et l'avènement de la technologie ont empêché l'instauration d'une tradition purement canadienne. Une étude consacrée à l'utilisation des débris de verre (calcin) et des moules à verre, notamment à la verrerie Burlington, montre à quel point les fabriques canadiennes se sont inspirées des motifs et procédés américains
Osteoblasts mediate the adverse effects of glucocorticoids on fuel metabolism
Long-term glucocorticoid treatment is associated with numerous adverse outcomes, including weight gain, insulin resistance, and diabetes; however, the pathogenesis of these side effects remains obscure. Glucocorticoids also suppress osteoblast function, including osteocalcin synthesis. Osteocalcin is an osteoblast-specific peptide that is reported to be involved in normal murine fuel metabolism. We now demonstrate that osteoblasts play a pivotal role in the pathogenesis of glucocorticoid-induced dysmetabolism. Osteoblast-targeted disruption of glucocorticoid signaling significantly attenuated the suppression of osteocalcin synthesis and prevented the development of insulin resistance, glucose intolerance, and abnormal weight gain in corticosterone-treated mice. Nearly identical effects were observed in glucocorticoid-treated animals following heterotopic (hepatic) expression of both carboxylated and uncarboxylated osteocalcin through gene therapy, which additionally led to a reduction in hepatic lipid deposition and improved phosphorylation of the insulin receptor. These data suggest that the effects of exogenous high-dose glucocorticoids on insulin target tissues and systemic energy metabolism are mediated, at least in part, through the skeleton.NHMRC Grants 402462 and 63281
Osteocalcin: A non-invasive index of metabolic bone disease in patients treated by CAPD
Osteocalcin: A non-invasive index of metabolic bone disease in patients treated by CAPD. Serum osteocalcin has been found to correlate with bone formation. However, present literature gives only limited data on osteocalcin and bone histomorphometry in patients undergoing peritoneal dialysis. This study assessed serum osteocalcin, dialysate osteocalcin, peritoneal clearance of osteocalcin (Clp-osteocalcin) and mass transfer of osteocalcin (MTp-osteocalcin), and evaluated relationships between these values and bone histomorphometry. Eighteen patients were treated by continuous ambulatory peritoneal dialysis (CAPD). Bone biopsies, serum and dialysate osteocalcin, serum levels of parathyroid hormone, alkaline phosphatase, aluminum, phosphate, Ca2+ and vitamin D3 metabolites were measured at the start and in 10 of the patients a year later. Serum osteocalcin was found to be elevated. Osteocalcin was detected in the dialysate resulting in significant values of Clp-osteocalcin and MTp-osteocalcin. Serum and dialysate levels of osteocalcin correlated significantly (r = 0.66, P < 0.001) and like MTp-osteocalcin with serum levels of alkaline phosphatase and PTH. Histomorphometry showed that osteitis fibrosa was the predominant bone disease detected. Serum concentration of osteocalcin correlated with osteoid thickness, eroded and osteoclast surfaces, aluminum staining, and some of the bone dynamic parameters. Dialysate osteocalcin, MTp-osteocalcin, PTH and alkaline phosphatase correlated with practically the same histomorphometric parameters as serum osteocalcin. No correlations were seen between Clp-osteocalcin and any histomorphometric parameters. Serum osteocalcin was elevated above the normal range, and significant positive correlations between serum osteocalcin and bone formation parameters were found. Serum osteocalcin correlated with almost the same histomorphometric parameters as PTH. Thus, serum levels of PTH and osteocalcin gave additional information to one another as non-invasive parameters in this group of patients. Hence, serum osteocalcin is a valuable non-invasive index of metabolic bone disease in patients treated by CAPD. The transperitoneal removal of osteocalcin does not appear to be clinically significant
Utilidad Del Módulo Ecologista Para El Logro De Capacidades En El Área De Ciencia Tecnología Y Salud En Los Estudiantes Del Tercer Ciclo Del Centro De Educación Básica Alternativa Crl Francisco Bolognesi
El propósito de la tesis fue determinar en qué medida la aplicación del “Módulo
Ecologista” logra el desarrollo de las capacidades en el área de Ciencia Tecnología y
Salud, de los estudiantes del tercer ciclo del Centro de Educación Básica Alternativo
Crl Francisco Bolognesi.
El tipo de estudio es aplicativo experimental con diseño pre experimental con pre y
post prueba, aplicado a una muestra de 30 alumnos de un total de 118. Para recoger
los datos se utilizó un cuestionario de 16 preguntas divididas en dos grupos de ocho
que corresponden a las dimensiones de la variable dependiente, (desarrollo de
capacidades del área de CTA), luego se aplicó el Módulo Ecologista, para finalmente
realizar una nueva medición de la variable dependiente, que nos dio a conocer los
cambios producidos en el logro de las capacidades de área. Los datos fueron
analizados a través del programa de cálculo Excel
Luego de la aplicación de los pre y post test además del Módulo Ecologista, se refleja
en términos generales un incremento en el desarrollo de las capacidades del área de
Ciencia Tecnología y Ambiente en un 37 % en la capacidad de Diseña prototipos
tecnológicos para resolver problemas de su entorno; y un 43% en la capacidad de de
Construye una posición crítica sobre la ciencia y tecnología, que se traduce en la
asimilación de su realidad concreta, conocimientos, habilidades, desarrollo de la
conciencia ambiental y actitudes positivas de los estudiantes en relación a su
entorno, en tal sentido asumimos la validez del Módulo Ecologista, en el propósito de
mejorar el desarrollo de capacidades de los estudiantes
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