922 resultados para Mineral carbonation
Resumo:
The aim of this study was to analyze vitamin D levels and their association with bone mineral density and body composition in primary antiphospholipid syndrome. For this cross-sectional study 23 premenopausal women with primary antiphospholipid syndrome (Sapporo criteria) and 23 age- and race-matched healthy controls were enrolled. Demographic, anthropometric, clinical and laboratorial data were collected using clinical interview and chart review. Serum 25-hydroxyvitamin D levels, parathormone, calcium and 24-hour urinary calcium were evaluated in all subjects. Bone mineral density and body composition were studied by dual X-ray absorptiometry. The mean age of patients and controls was 33 years. Weight (75.61 [20.73] vs. 63.14 [7.34] kg, p=0.009), body mass index (29.57 [7.17] vs. 25.35 [3.37] kg, p=0.014) and caloric ingestion (2493 [1005.6] vs. 1990 [384.1] kcal/day, p=0.03) were higher in PAPS than controls. All PAPS were under oral anticoagulant with INR within therapeutic range. Interestingly, biochemical bone parameters revealed lower levels of 25-hydroxyvitamin D [21.64 (11.26) vs. 28.59 (10.67) mg/dl, p=0.039], serum calcium [9.04 (0.46) vs. 9.3 (0.46) mg/dl, p=0.013] and 24-hour urinary calcium [106.55 (83.71) vs. 172.92 (119.05) mg/d, p=0.027] in patients than in controls. Supporting these findings, parathormone levels were higher in primary antiphospholipid syndrome than in controls [64.82 (37.83) vs. 44.53 (19.62) pg/ml, p=0.028]. The analysis of osteoporosis risk factors revealed that the two groups were comparable (p>0.05). Lumbar spine, femoral neck, total femur and whole body bone mineral density were similar in both groups (p>0.05). Higher fat mass [28.51 (12.93) vs. 20.01 (4.68) kg, p=0.005] and higher percentage of fat [36.08 (7.37) vs. 31.23 (4.64)%, p=0.010] were observed in PAPS in comparison with controls; although no difference was seen regarding lean mass. In summary, low vitamin D in primary antiphospholipid syndrome could be secondary to higher weight and fat mass herein observed most likely due to adipocyte sequestration. This weight gain may also justify the maintenance of bone mineral density even with altered biochemical bone parameters. Lupus (2010) 19, 1302-1306.
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To investigate bone mineral accretion in growing children, the Saskatchewan Pediatric Bone Mineral Accrual Study was initiated in 1991. The study involves the collection of dietary and physical activity information along with anthropometric growth and maturity measurements every 6 months and dual-energy X-ray absorptiometer (DXA) bone scans of the whole body, AP lumbar spine and proximal femur taken annually, The study has now finished its 6th year and 68 males and 72 females from an original sample of 228 elementary schoolchildren are still involved, To investigate how bone mineral at clinically important sites proceeds in relation to maturation we developed distance and velocity growth curves for height and bone mineral content (BMC) for the AP lumbar spine, the femoral neck and the whole body, In both boys and girls, over 35% of total body and AP spine bone mineral and over 27% of the bone mineral at the femoral neck was laid down during the 4-year adolescent period surrounding peak linear growth velocity. The clinical significance of these values can be appreciated by consideration of the fact that as much bone mineral will be laid down during these 4 adolescent growing years as most people will lose during all of adult life.
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We measured bone mineral content (BMC) and estimated calcium accretion in children to provide insight into dietary calcium requirements during growth. Anthropometric measurements were done semiannually and whole-body BMC was measured annually by dual-energy X-ray absorptiometry for 4 y in 228 children (471 scans in 113 boys and 507 scans in 115,girls). Mean values for BMC, skeletal area, and height were calculated for 1-y age groups from 9.5 to 19.5 y of age. Cross-sectional analysis of the pooled data gave peak height velocity and peak BMC velocity (PBMCV) and the ages at which these occurred (13.3 y in boys and 11.4 y in girls). PBMCV did not peak until 1.2 y after peak height velocity in boys and 1.6 y after peak height velocity in girls. Within 3 y on either side of PBMCV, boys had consistently higher BMC and BMC velocity compared with girls and the discrepancy increased steadily through puberty. Three years before PBMCV, BMC Values in girls were 69% of those in boys; 3 y after peak height velocity this proportion fell to 51%. PBMCV was 320 g/y in boys and 240 g/y in girls. Under the assumption that bone mineral is 32.2% calcium, these values corresponded to a daily calcium retention of 282 mg in boys and 212 mg in girls. Individual Values could be much greater. In one boy in a group of six subjects for whom there were enough data for individual analysis through puberty, PBMCV was 555 g Ca/y or 490 mg Ca/d. Such high skeletal demands for calcium require large dietary calcium intakes and such requirements may not be met immediately in some children.
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Maximization of bone accrual during the growing years is thought to be an important factor in minimizing fracture risk in old age. Mechanical loading through physical activity has been recommended as a modality for the conservation of bone mineral in adults; however, few studies have evaluated the impact of different loading regimes in growing children. The purpose of this study was to compare bone mineral density (BMD) in weight-bearing and non-weight-bearing limbs in 17 children with unilateral Legg Calve Perthes Disease (LCPD). Children with this condition have an altered weight-bearing pattern whereby there is increased mechanical loading on the noninvolved normal hip and reduced loading on the involved painful hip. Thus, these children provide a unique opportunity to study the impact of differential mechanical loading on BMD during the growing years while controlling for genetic disposition. BMD at four regions of the proximal femur (trochanter, intertrochanter, femoral neck, total of the regions) was measured using dual energy x-ray absorptiometry (DXA), and the values were compared between the involved and noninvolved sides of the children with LCPD. The BMD of both sides also were compared with normative values based on both chronological and skeletal age data. A significantly higher BMD was found on the noninvolved side over the involved side for all regions (P
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Objective: Only few large families with multiple endocrine neoplasia type 1 (MEN1) have been documented. Here, we aimed to investigate the clinical features of a seven-generation Brazilian pedigree. which included 715 at-risk family members. Design: Genealogical and geographic analysis was used to identify the MEN1 pedigree. Clinical and genetic approach was applied to characterize the phenotypic and genotypic features of the family members. Results: Our genetic data indicated that a founding mutation in the MEN1 gene has occurred in this extended Brazilian family. Fifty family members were diagnosed with MEN1. Very high frequencies of functioning and non-functioning MEN1-related tumors were documented and the prevalence of prolactinoma (29.6%) was similar to that previously described in prolactinoma-variant Burin (32%). In addition, bone mineral density analysis revealed severe osteoporosis (T,-2.87 +/- 0.32) of compact bone (distal radius) in hyperparathyroidism (HPT)/MEN1 patients. while marked bone mineral loss in the lumbar spine (T,-1.95 +/- 0.39). with most cancellous bone, and femoral neck (mixed composition: T,-1.48 +/- 0.27) were also present. Conclusions: In this study, we described clinically and genetically the fifth largest MEN1 family in the literature. Our data confirm previous findings suggesting that prevalence of MEN1-related tumors in large families may differ from reports combining cumulative data of small families. Furthermore. we were able to evaluate the bone status in HPT/MEN1 cases, a subject that has been incompletely approached in the literature. We discussed the bone loss pattern found in our MEN1 patients comparing with that of patients with sporadic primary HPT.
Resumo:
Differences in bone mineral density (BMD) patterns have been recently reported between multiple endocrine neoplasia type 1-related primary hyperparathyroidism (HPT/MEN1) and sporadic primary HPT However studies on the early and later outcomes of bone/renal complications in HPT/MEN1 are lacking In this cross sectional study performed in a tertiary academic hospital 36 patients cases with uncontrolled HPT from 8 unrelated MEN1 families underwent dual energy X ray absorptiometry (DXA) scanning of the proximal one third of the distal radius (1/3DR) femoral neck, total hip, and lumbar spine (LS) The mean age of the patients was 389 +/- 145 years Parathyroid hormone (PTH)/calcium values were mildly elevated despite an overall high percentage of bone demineralization (77 8%) In the younger group (<50 years of age) demineralization in the 1/3DR was more frequent more severe and occurred earlier (40% Z-score 1 81 +/- 0 26) The older group (>50 years of age) had a higher frequency of bone demineralization at all sites (p < 005) and a larger number of affected bone sites (p < 0001), and BMD was more severely compromised in the 1/3DR (p = 007) and LS (p= 002) BMD values were lower in symptomatic (88 9%) than in asymptomatic HPT patients (p < 006) Patients with long standing HPT (>10 years) and gastnnoma/HPT presented significantly lower 1/3DR BMD values Urolithiasis occurred earlier (<30 years) and more frequently (75%) and was associated with related renal comorbidities (50%) and renal insufficiency in the older group (33%) Bone mineral- and urolithiasis-related renal complications in HPT/MEN1 are early onset frequent extensive severe and progressive These data should be considered in the individualized clinical/surgical management of patients with MEN1 associated HPT (C) 2010 American Society for Bone and Mineral Research
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P>Objective Limited data have been reported on the effect of parathyroidectomy (PTx) on bone mineral density (BMD) in the setting of patients with hyperparathyroidism (HPT) associated with multiple endocrine neoplasia type 1 (MEN1). This study investigates the impact of total PTx on BMD in patients with HPT/MEN1. Design and patients A case series study was performed in a tertiary academic hospital. A total of 16 HPT/MEN1 patients from six families harbouring MEN1 germline mutations were subjected to total PTx followed by parathyroid auto-implant in the forearm. Measurements Bone mineral density values were assessed using dual-energy X-ray absorptiometry. Results Before PTx, reduced BMD (Z-score <-2 center dot 0) was highly prevalent in the proximal one-third of the distal radius (1/3 DR) (50%), lumbar spine (LS) (43 center dot 7%), ultradistal radius (UDR) (43 center dot 7%), femoral neck (FN) (25%) and total femur (TF) (18 center dot 7%) in the patients. Fifteen months after PTx, we observed a BMD improvement in the LS (from 0 center dot 843 to 0 center dot 909 g/cm2; +8 center dot 4%, P = 0 center dot 001), FN (from 0 center dot 745 to 0 center dot 798 g/cm2; +7 center dot 7%, P = 0 center dot 0001) and TF (from 0 center dot 818 to 0 center dot 874 g/cm2; +6 center dot 9%, P < 0 center dot 0001). No significant change was noticed in the 1/3 DR and UDR after PTx. Conclusions This data confirmed BMD recovery in the LS and FN after PTx in HPT/MEN1 patients. We also documented a significant BMD increase in the TF and no change in both the 1/3 DR and UDR BMD after PTx. Our data suggest that LS and proximal femur are the most informative sites to evaluate the short-term BMD outcome after PTx in HPT/MEN1 subjects.
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Objective: The study was designed to evaluate the effects of strength training (ST) on the bone mineral density (BMD) of postmenopausal women without hormone replacement therapy. Method: Subjects were randomized into untrained (UN) or trained (TR) groups. The TR group exercised three ST sessions per week for 24 weeks, and body composition, muscular strength, and BMD of the lumbar spine and femur neck were evaluated. Results: Body weight, mass index, and fat percentage were lower after 24 weeks only in the TR group (p < .05). SR also improved the one repetition maximum test in 46% and 39% of upper and lower limbs, respectively. The percentage of demineralization was higher in the UN group than in the TR group at the lumbar spine and femoral neck (p < .05). Discussion: Results indicated that 24 weeks of ST improved body composition parameters, increased muscular strength, and preserved BMD in postmenopausal women.
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The present randomized, controlled prospective study evaluated the histomorphological response of human dental pulps capped with two grey mineral trioxide aggregate (MTA) compounds. Pulp exposures were performed on the occlusal floor of 40 human permanent pre-molars. The pulp was capped either with ProRoot (Dentsply) or MTA-Angelus (Angelus) and restored with zinc oxide eugenol cement. After 30 and 60 days, teeth were extracted and processed for histological examination and the effects on the pulp were scored. The data were subjected to Kruskal-Wallis and Conover tests (alpha = 0.05). In five out of the 40 teeth bacteria were present in pulp tissue. No significant difference was observed between the two materials (P > 0.05) in terms of overall histological features (hard tissue bridge, inflammatory response, giant cells and particles of capping materials). Overall, 94% and 88% of the specimens capped with MTA-Angelus and ProRoot, respectively, showed either total or partial hard tissue bridge formation (P > 0.05). Both commercial materials ProRoot (Dentsply) and MTA-Angelus (Angelus) produced similar responses in the pulp when used for pulp capping in intact, caries-free teeth.
Resumo:
Introduction: An experimental mineral trioxide aggregate sealer (MTAS) has been developed for use as a root canal sealer. The aim of this study was to evaluate the setting time, pH, and calcium ion release of MTAS compared with white Portland cement (CPB-40; Votorantin Cimentos, Camargo Correa SA, Pedro Leopoldo, MG, Brazil), white MTA Angelus (MTA; Angelus, Londrina, PR, Brazil), and AH Plus (Dentsply DeTrey, Konstanz, Germany). Methods: For the evaluation of setting time, each material was analyzed using Gilmore-type needles. Polyethylene tubes with the materials were immersed in distilled water for the measurement of pH (digital pH meter) and calcium release (atomic absorption spectrophotometry). The evaluations were performed at 3, 6, 12, 24, and 48 hours and 7, 14, and 28 days. Data were analyzed by analysis of variance and the Tukey test at 5% significance level. Results: MTAS showed higher calcium release at all experimental periods, a greater increase in pH up to 48 hours and the longest setting time. Conclusions: MTAS presented favorable properties for its indication as a root canal sealer. (J Endod 2011;37:844-846)
Resumo:
Introduction: To evaluate calcium ion release and pH of Sealer 26 (S26) (Dentsply, Rio de Janeiro, RJ, Brazil), white mineral trioxide aggregate (MTA), Endo CPM Sealer (CPM1) (EGEO SRL Bajo licencia MTM Argentina SA, Buenos Aires, Argentina), Endo CPM Sealer in a thicker consistency (CPM 2), and zinc oxide and eugenol cement (ZOE). Methods: Material samples (n = 10) were placed in polyethylene tubes and immersed in 10 mL of distilled water. After 3, 6,12,24, and 48 hours and 7,14, and 28 days, the water pH was determined with a pH meter, and calcium release was assessed by atomic absorption spectrophotometry. An empty tube was used as the control group. Results: The control group presented a pH value of 6.9 at all studied periods and did not show the presence of calcium ion. S26 presented greater hydroxyl ion release up to 12 hours (p < 0.05). From 24 hours until 28 days, S26, MTA, CPM1, and CPM2 had similar results. in ail periods, ZOE presented the lowest hydroxyl ion release. CPM1, followed by CPM2, released the most calcium ions until 24 hours (p < 0.05). Between 48 hours and 7 days, CPM1 and CPM2 had the highest release. A greater calcium ion release was observed for CPM2, followed by CPM1 at 14 days and for S26, CPM1, and CPM2 at 28 days. ZOE released the least calcium ions in all periods. Conclusion: Sealer 26, MTA, and Endo CPM sealer at normal or thicker consistency release hydroxyl and calcium ions. Endo CPM sealer may be an alternative as root-end filling material. (J Endod 2009;35:1418-1421)
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This study evaluated the influence of addition of 10% calcium chloride (CaCl(2)) on the setting time, solubility, disintegration, and pH of white MTA (WMTA) and white Portland cement (WPC). A test of the setting time was performed following the #57 ADA specifications and a test of the final setting time according to the ASTM. For the solubility tests disintegration and pH, Teflon rings were filled with the cements and weighed after setting. After 24 h in a desiccator, they were once again weighed. Thereafter, they were immersed in MiliQ water for 24 and 72 h and 7, 14, and 28 days, with maintenance in the desiccator and weighing between periods. The pH of water in which the rings were immersed was measured immediately after contact with them and in the other periods. The addition of CaCl(2) provided a significant reduction (50%) in the initial setting time of cements. The final setting time of WMTA was reduced in 35.5% and the final setting time of WPC in 68.5%. The WMTA with CaCl(2) absorbed water and gained weight with time, except for in the 24-h period. The addition of CaCl(2) to the WPC reduced its solubility. The addition of CaCl(2) increased the pH of WMTA in the immediate period and at 24 and 72 h and for WPC in the immediate period and at 24 h. The addition of CaCl(2) to WMTA and WPC reduced the setting times and solubility of both and increased the pH of cements in the initial periods. (J Endod 2009;35:550-554)
Resumo:
The aim of this study was to evaluate the reaction of the pulp tissue against mineral trioxide aggregate (MTA) with or without 10% calcium chloride (CaCl2). Pulpotomies were performed in 4 canines and 8 premolars of two 8-month-old dogs. MTA with or without CaCl2 was applied on the pulp tissue. The animals were killed after 90 days, and the specimens were processed for the microscopic analysis. Pulp tissue response was similar for MTA with and without CaCl2 Pulp vitality was present in all specimens, along with pulp repair with formation of mineralized tissue bridging. The addition of CaCl2 to MTA did not change its biologic properties in formation of mineralized barrier after pulpotomy.