Altered loading patterns and femoral bone mineral density in children with unilateral Legg-Calve-Perthes disease

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

Multiple endocrine neoplasia type 1 in Brazil: MEN1 founding mutation, clinical features, and bone mineral density profile

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.

Early-Onset, Progressive, Frequent, Extensive, and Severe Bone Mineral and Renal Complications in Multiple Endocrine Neoplasia Type 1-Associated Primary Hyperparathyroidism

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

Bone mineral density analysis in patients with primary hyperparathyroidism associated with multiple endocrine neoplasia type 1 after total parathyroidectomy

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.

Strength Training Preserves the Bone Mineral Density of Postmenopausal Women Without Hormone Replacement Therapy

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.

Bovine Bone Screws: Metrology and Effects of Chemical Processing and Ethylene Oxide Sterilization on Bone Surface and Mechanical Properties

We assess the effects of chemical processing, ethylene oxide sterilization, and threading on bone surface and mechanical properties of bovine undecalcified bone screws. In addition, we evaluate the possibility of manufacturing bone screws with predefined dimensions. Scanning electronic microscopic images show that chemical processing and ethylene oxide treatment causes collagen fiber amalgamation on the bone surface. Processed screws hold higher ultimate loads under bending and torsion than the in natura bone group, with no change in pull-out strength between groups. Threading significantly reduces deformation and bone strength under torsion. Metrological data demonstrate the possibility of manufacturing bone screws with standardized dimensions.

Angiotensin processing is partially carried out by carboxypeptidases in the rat mesenteric arterial bed perfusate

Here we investigated the possible association between the carboxypeptidase A (CPA)-like activity of the rat mesenteric arterial bed (MAB) perfusate and the ability of this fluid of forming angiotensin (Ang) 1-9 and Ang 1-7 upon incubation with Ang I and Ang II, respectively. Initially, we observed that anion exchange chromatography of the perfusate would consistently split the characteristic Z-Val-Phe-hydrolyzing activity of CPA-like enzymes into five distinct peaks, whose proteolytic activities were then determined using also Ang I and Ang II as substrates. The resulting proteolytic profile for each peak indicated that rat MAB perfusate contains a complex mixture of carboxypeptidases; tentatively, five carboxypeptidases were distinguished based on their substrate preferences toward Z-Val-Phe. Ang I and Ang II. The respective reactions, namely, Z-Val-Phe cleavage, Ang I to Ang 1-9 conversion and Ang II to Ang 1-7 conversion, were inhibited by 1,10-phenanthroline and nearly fully blocked by potato carboxypeptidase inhibitor. Also, all the CPA-like activity peaks prepared by anion exchange chromatography were tested negative for contaminating Ang I-converting enzyme-2, cathepsin A and prolylcarboxypeptidase. Overall, our results indicate that rat MAB perfusate contains a multiplicity of Ang I and Ang II-processing CPA-like enzymes whose proteolytic specificities suggest they might perform peculiar regulatory roles in the local resin-angiotensin system. (C) 2008 Elsevier B.V. All rights reserved.