Significant Decrease In Bone Density Research Articles

7588 Coexistent Toxic Nodular Goiter And Primary Hyperparathyroidism (PHPT), A Combo With Diagnostic And Management Implications

Abstract Disclosure: D. Dave: None. A. Bhan: None. S.D. Rao: None. About 17-84% of patients with PHPT have concomitant thyroid disorders, but the prevalence of coexistent hyperthyroidism in PHPT varies 9-14 %. A vast majority had Graves’ disease with only 3 cases of toxic multinodular goiter (MNG) and PHPT reported in the literature as of 2022 ([1]). We present a rare case of coexistent toxic MNG and PHPT. Case Description: A 68y woman presented with recent 23 kg unintended weight loss and palpitations, but no other symptoms. Denied having kidney stones or fractures. On examination she had fine tremors of hands, MNG without exophthalmos. An ultrasound showed multinodular MNG with cystic lesions. A diagnosis of toxic MNG was made. Laboratory results were: TSH (<0.01 uIU/mL), free T4 1,68 ng/dL (normal: 0.61-1.44 ng/ml), high serum Ca (11.0 - 11.4 mg/dl) over 4y, but PTH was unavailable prior to the visit when it was 107 pg/ml and 89 pg/ml after 3 months of antithyroid therapy. Despite clinical and biochemical euthyroidism after 3 months, serum Ca and PTH levels remained high (11.4 mg/dl and 89 pg/ml respectively). Because she had pulmonary embolism a few years ago, we deferred parathyroidectomy until complete remission of hyperthyroidism. Discussion: Hypercalcemia is the biochemical hallmark of PHPT but can occur in 2-10% of patients with hyperthyroidism alone but only 1% of those will have coexistent PHPT. When these two conditions coexist, hypercalcemia is moderate to severe, and an occasional patient may present with hypercalcemic crisis (2). Prior to the availability of PTH assays, it was a challenge to diagnose coexistent PHPT. Hypercalcemia in hyperthyroidism responds to propranolol but not in PHPT, although the response is variable (3). With the availability of sensitive PTH assays, this maneuver is not necessary. In most cases, current PTH assays distinguish hypercalcemia of hyperthyroidism with suppressed PTH from coexistent PHPT in whom PTH level is non-suppressed or elevated. Monitoring serum Ca and PTH levels during therapy of hyperthyroidism would be useful as normalization of serum Ca and PTH has occasionally been reported (4). In our patient, serum Ca and PTH levels remained high with 3-months of methimazole and atenolol. The impact of both conditions on bone and mineral metabolism are profound, with fractures and kidney stones. Since kidney stones are uncommon in hyperthyroidism, presence of kidney stone in a hyperthyroid hypercalcemic patient should alert the possibility of PHPT. Similarly, significant decrease in bone density in such patient also raises the possibility of PHPT. Prompt diagnosis and appropriate treatment of both conditions is necessary to avoid irreversible complications.

Retrieval of a displaced implant from the mandibular body: A clinical report

The posterior mandible is often regarded as a reliable area for achieving primary stability during implant placement. However, in rare instances, implant displacement can occur in this region because of a significant decrease in bone density. Typically, surgical procedures such as the lateral or crestal approach have been used to remove displaced implants, requiring extensive bone removal and postponing implant placement for between 3 and 6 months. This clinical report presents an uncommon occurrence of implant displacement in the posterior mandible and introduces a less invasive approach to recovering it. This technique utilized the long screw of an open-tray impression post and an abutment to retrieve the displaced implant while simultaneously performing implant placement at the same site.

Biomodulation of Induced Tooth Movement by Three Methods, Corticopuncture, Photobiomodulation, and Their Combination: An Animal Study.

Objective: The aim of this study was to assess the effects of accelerated tooth movement (ATM) methods: corticopuncture (CP), photobiomodulation (PBM), and their combination (CP + PBM) by evaluating tooth displacement, alveolar bone changes, and molecular and cellular response compared with conventional induced tooth movement. Materials and methods: Tooth movement and bone changes were evaluated on days 1, 3, and 7 (9 animals per time point) using microtomography, histological, and immunohistochemical evaluation, at compression and tension sites. CP groups received two perforations in the palate and one mesial to the molars. PBM was performed using GaAlAs diode laser applied every other day for 7 days (λ = 808 nm, 100 mW) in two points for 15 sec/point and total energy of 3 J. Results: Tooth movement was significantly increased in all three ATM groups after 7 days compared with the control group (mean 0.24 mm) by 27% PBM (0.31 mm), 45% CP (0.35 mm), and 57% CP + PBM (0.38 mm) (p < 0.05). At the compression side, all ATM groups showed significant decrease in bone density on day 3 (p < 0.05) and significant less bone volume on day 7 compared with Control (p < 0.05). At the tension side, PBM group showed a significant increase in bone density and volume on day 3 (p < 0.05). Immunohistochemistry analysis showed that at the compression side, tartrate-resistant acid phosphatase-positive cells, RANKL, and tumor necrosis factor-alpha expression were highly marked of the PBM and the combined method groups (p < 0.05). PBM and CP + PBM groups showed a significant increase in expression Runt-related transcription factor 2 and osterix (p < 0.05) at the tension side. Conclusions: All ATM groups showed increase on tooth displacement with CP + PBM group showing greatest tooth displacement. CP method appears to stimulate bone catabolism, PBM has more effect on bone formation, and the combined method showing a synergistic effect on bone remodeling.

Non-alcoholic fatty liver disease is associated with decreased bone mineral density in upper Egyptian patients

Nonalcoholic fatty liver disease (NAFLD) has been linked with a number of extra hepatic diseases and could be a potential risk factor of decreasing bone mineral density. To determine whether Upper Egyptian patients with NAFLD are at risk of developing osteoporosis. Cross sectional study was done on a total 100 individuals; 50 patients diagnosed with NAFLD (based on ultrasound imaging) crossed-matched with 50 individuals without NAFLD based on age, sex and body mass index. Bone mineral density, serum calcium and phosphorus levels, serum parathyroid hormone, serum vitamin D and fasting insulin level were assessed. Osteoporosis was prevalent in NAFLD patients versus to controls (19/50 vs. 0/50; P < 0.001). There was significant decrease in bone mineral density in NAFLD patients than controls (− 2.29 ± 0.4 vs. − 1.53 ± 0.1; P < 0.001). There was a statistical significance decrease in serum vitamin D and calcium levels in NAFLD patients than controls. Furthermore, vitamin D levels in the NAFLD group was a predictor for osteoporosis (OR 0.614; 95% CI 0.348–0.825). Patients with NAFLD tend to have a significant decrease in bone density, vitamin D, and serum calcium levels than controls.

Прочность костной ткани по результатам ультразвуковой денситометрии у детей, рожденных после проведения экстракорпорального оплодотворения (ЭКО) с массой тела менее 1500 г

Aim: to assess the status of bone mineral density (BMD) using the ultrasound densitometry as a screening technique in premature in vitro fertilization (IVF) and non-IVF infants weighing less than 1500 g at birth. Patients and Methods: the study included 189 premature babies who stayed in the department for newborns and premature infants with health problems. The infants were divided into two groups, depending on the IVF use: born through the IVF or conceived naturally. Each of the groups was divided into two subgroups based on the infant weight at birth: subgroups A consisted of very low birth weight (VLBW) babies and subgroups B consisted of extremely low birth weight (ELBW) babies. The first group (n=101) consisted of IVF-infants, 52 and 49 of them were included in subgroups 1A and 1B, respectively. The second group (comparison, n=88) consisted of the naturally conceived infants, 46 and 42 of them were included in subgroups 2A and 2B, respectively. BMD was measured using the ultrasound densitometry method. The evaluated parameters comprised the speed of sound (SOS) and Z-score, representing the difference in BMD between the studied infants and the mean BMD of other children of the same age and gender (standard deviation (SD) for the tibia). Z-score &lt;-1 SD (SOS &lt;10 ‰ and &gt;3‰) was associated with a low bone density and Z-score &lt;-2 SD (SOS &lt;3 ‰) – with a clinically significant low bone density. Results: the normal values of bone density were found in 39 (38.6%) infants of group 1 and 58 (65.9%) infants of group 2 (p&gt;0.05). In the group 1 infants a decrease in bone density was found more frequently than in the group 2 infants: 49 (48.5%) and 21 (23.8%), respectively, p&lt;0.05, and the difference was statistically significant (&lt;-1SD). A clinically significant low bone density (SOS &lt;3‰) found in 13 (12.8%) IVF- babies. The extremely low birth weight (ELBW) in IVF-babies is a risk factor for osteopenia and osteoporosis. Conclusion: a significant decrease in the bone density values (SOS &lt;10‰ and &gt;3‰) was found in IVF-infants as compared to those in naturally conceived infants. A clinically significant decrease in bone density in premature IVF-infants with ELBW was reported in 12.8% of cases. The early diagnosis of osteopenia can be established by using a safe technique — the ultrasound densitometry. KEYWORDS: bone mineral density, densitometry, in vitro fertilization, IVF, premature babies, osteopenia, bone tissue, screening, very low birth weight, extremely low birth weight. FOR CITATION: Merzlyakova D.R., Hafizova N.R., Vakhitova G.A. et al. The assessment of bone strength based on the results of ultrasound densitometry in infants born after in vitro fertilization (IVF) weighing less than 1500 g. Russian Journal of Woman and Child Health. 2023;6(1):34–38 (in Russ.). DOI: 10.32364/2618-8430-2023-6-1-34-38.

Characteristics of the state of bone tissue in genetically modified mice with impaired enzymatic regulation of steroid hormone metabolism

Introduction: The aim was to evaluate the structural and functional changes of bone tissue in mice with null expression of 11β-HSD2 or both 11β-HSD2 and Apolipoprotein E.&#x0D; Materials and methods: The experimental study was performed in 60 male mice, weighting 24–30 g. The animals were kept in accordance with the rules of laboratory practice for preclinical studies on the territory of the Russian Federation. Mice lacking 11β-HSD2 (Hsd2-/-) and male mice lacking 11β-HSD2 and Apolipoprotein E (Hsd2-/-/Apoe-/-) were used in the study. We studied and characterized the state of bone tissue, indicators of bone density, microcircu­lation in bone tissue, endothelial dysfunction coefficient, width of bone trabeculae, as well as serum concentrations of bone alkaline phosphatase, hydroxyproline, deoxyprinoline and expression levels of p53, Bcl2, Bax, eNOS genes.&#x0D; Results and discussion: We showed that mice with the Hsd2-/- genotype with no expression of 11ß-HSD2 by the 6th month of life showed a statistically significant decrease in bone density, which progresses to the 7th and 8th months of life. At the 8th month of animal life, a decrease in bone density is accompanied by a statistically significant decrease in the level of microcirculation in the bone and an increase in the coefficient of endothelial dysfunction. Taking into account the relationship of endothelial dysfunction, atherogenesis and disorders in the processes of bone remodeling, in the framework of this study, we also assessed the state of bone tissue in double transgenes with the genotype Hsd2-/-/Apoe-/-, which lack the expression of both 11ß-HSD2 and Apolipoprotein E. In this study, we also saw increased acti­vation of processes leading to disruption of bone remodeling processes. In the group of the animals with the genotype Hsd2-/-/Apoe-/-, we found statistically significant differences from the mice with no expression of 11ß-HSD2 in bone density and microcirculation, and the width of bone trabeculae. Also, a statistically significant increase in hydroxypro­line and deoxyprinoline was found in the group of double transgenes, in the absence of significant changes in the con­centration of bone alkaline phosphatase. This fact indicates a pronounced activation of bone resorption processes in the absence of activation of osteosynthesis processes, which leads to the detected violation of bone remodeling processes.&#x0D; Conclusion: Thus, we have shown that a violation of the metabolic regulation of steroid hormone metabolism in ani­mals with null expression of the 11ß-HSD2 (Hsd2-/- genotype) leads to the development of signs of osteoporosis – bone density decreases, which is accompanied by a decrease in the width of bone trabeculae, the level of microcirculation in bone tissue decreases simultaneously with an increase in the coefficient of endothelial dysfunction. The additional null expression of ApoE gene in double transgenes with the genotype Hsd2-/-/Apoe-/- leads to an increase in the severity of changes associated with a violation of bone remodeling processes and, in addition to a more pronounced change in bone tissue density, bone trabecular width, microcirculation and the coefficient of endothelial dysfunction leads to an increase in the concentration of biochemical markers of bone resorption. These changes indicate the important role of the enzyme 11ß-hydroxysteroid dehydrogenase type 2 in the processes of bone remodeling disorders.&#x0D; Graphical abstract:

형태와 빈도에 따른 저강도 운동이 근감소증 비만 고령여성의 신체조성 변화에 관한 연구

The purpose of this study is to investigate any changes in body composition, such as muscle mass, %fat, and bone density, in exercise intervention according to the frequency of low-intensity aerobic exercise and resistance exercise for 16 weeks.BRThe subjects of the study were women aged over 75 yrs older living in Jin-gu, Busan, who were selected for sarcopenia by diagnosis of sarcopenia (ASM/weight, % ; 25.6% or less) and obesity (% fat, % ; 30% or over), Through drawing lots, a total of 104 people participated in the experiment, 29 people were eliminated from the pre-test measurement. And 29 people were excluded from the exercise intervention. The participants were randomly assigned into 5 groups; low intensity aerobic exercise 3 times per week group (n=10, 75.6±3.5 yrs), low intensity aerobic exercise 5 times per week group (n=8, 74.2±3.9 yrs), low intensity resistance exercise 3 times per week group (n=10, 75.4±3.7 yrs), low intensity resistance exercise 5 times per week group(n=8, 75.6±4.1 yrs) and a control group (n=10, 77.7±3.8 years).BRFor the statistical analysis, such as One-Way ANOVA, t-test, and Two-Way Repeated measures ANOVA was calculated using SPSS Version 22.0. To verify mean differences between the 5 groups, two-way repeated measures ANOVA was used.BRAs a result of the study, the interaction effect of the group and time period of %fat was shown (p＜.05), As a result of post-verification, A5-G and R5-G were higher than CG. In the change in the main effect of the time period within the group, there was a significant decrease in A5-G (p＜.001) and R5-G (p＜.01). And in the change in LBM, there were no interaction effects and main effects. And the interaction effect was not shown in the change in Total BMD, but a significant decrease was shown in R3-G (p＜.01) and CG (p＜.05) in the change in the main effect.BRBased on the research results, The interaction effect of aerobic exercise and resistance exercise 5 times a week was shown in the body fat rate change according to the low intensity form and frequency of exercise for 16 weeks in elderly women with muscle fat and bone density. However, through this study, there is a significant decrease in bone density in older women in the control group and aerobic exercise and resistance exercise group conducted three times a week, so it seems to play a role in suppressing fat and bone density due to aging.

Cone Beam Computed Tomography Assessment of Cervical Spine Bone Density

Age-related loss of bone density is a characteristic of osteoporosis, leading to reduced bone strength and increased risk of fracture. In spine surgery patients, osteoporosis also leads to poor outcomes, including pedicle screw loosening, proximal junctional failure, cage subsidence, and adjacent segment disease. Osteoporosis screening is generally performed using dual energy X-ray absorptiometry (DXA) to assess bone density. Cone beam computed tomography (CBCT) is widely used in orthopedic surgeries, including spine surgeries, and in dental and maxillofacial surgery to visualize teeth and jaws for pathology, surgical planning for jaw and TMJ joint reconstruction, structural maxillofacial deformity, pre-operative implant site assessment, 3D cephalometry, and appropriate treatment planning. CBCT is also used for evaluation of cervical vertebrae in skeletal maturation - growth assessment, diagnosis of obstructive sleep apnea, and temporomandibular disorders. In comparison to traditional computed tomography (CT), CBCT introduces several advantages including high spatial resolution (favorable for bone architecture evaluation); high image accuracy; low cost, faster scan time, ease of use, compact machinery, and low radiation exposure. Few studies have investigated the potential use of CBCT images for opportunistic assessment of bone health as an alternative to traditional CT and DXA. This study investigates whether bone density in the C3 vertebrae as determined by CBCT image analysis aligns with previously known trends of age-related bone loss in women post-menopause. Specifically, this study examines changes in bone density of the C3 vertebrae in females, beginning from puberty to post-menopause to late adulthood. Since the use of CBCT beyond dentistry is not well-established, the overarching goal of this study is to provide support for the reliability of dental CBCT images in the determination of bone health for orthopedic applications. This study aims to provide support for the reliability of cone beam CT in allowing for measurements of bone density. The use of CBCT for opportunistic screening of osteoporosis and potentially orthopedic surgeries is highly relevant for medical and dental professionals. The various advantages of CBCT, including high accuracy, low costs, and greater convenience strengthens its position as a potential alternative to traditional CT. Also, as a result of longer life expectancies, more osteoporotic patients are visiting dental clinics, and existing CBCT scans could be utilized to assess osteoporosis risk. Cone beam scans of 416 female patients with ages ranging from 10 to 93 years were obtained between 2010 - 2019. CBCT scans included visualization of the patient's skull, jaw, facial bones, and upper portion of the cervical spine. Sagittal views of the scans were analyzed, with a specific focus on the C3 vertebrae. ImageJ analysis was used to quantify the intensity of the C3 vertebrae region of interest, as a measure of bone density after calibration. Intensity of the muscle area adjacent to the C3 vertebrae and intensity of air in the lungs were measured for the internal calibration of CT Hounsfield units (HU). A linear and spline lines of fit showing changes in bone density values as a function of age were generated to display the overall decline in bone density in females. The linear lines of fit, confidence intervals, linear equations, and R values were calculated using JMP statistical software based on measurements retrieved from the 416 patient scans. A decline in bone density with age was observed (-2.83 HU/year, p< 0.0001). A rapid decline was observed after 50 years of age (-3.72 HU/year, p=0.0001). These findings are consistent with previously established trends depicting changes in BMD as a function of age in females, such that peak loss of bone density occurs during the first few year's post-menopause, beginning around ages 50 to 54. The finding that female subjects aged 50-93 years exhibited a significant decrease in bone density is in line with scientific literature exploring the increased prevalence of osteoporosis in postmenopausal women. The ability to identify these established trends using CBCT scans provides evidence for the utility of obtaining bone density measurements through CBCT image analysis. Our findings may be useful in providing evidence in support of CBCT scans as an alternative method of osteoporosis screening and assessment of bone quality in orthopedic and dental surgery patients. Notable limitations of the present study include the exclusion of body mass index (BMI) and race, among other demographic information. Further efforts to obtain this demographic information would be crucial in developing a more complete understanding of our sample data.

Dental implant displacement into the mandibular body: a case report

Posterior mandible region is considered a highly predicable place for primary stability during dental implant placement. Although, this region can present a significant decrease in bone density, which can lead to implant dislocation during insertion. The present case reports an unusual dislocation of dental implant in a 59 old healthy patient's mandible and a secure solution for this kind of complication. During the drilling, bone quality type IV was observed. In sequence, implant was abruptly inserted in the perforation site and dropped into the bone marrow. Panoramic radiograph showed the implant inside bone marrow, close to mandibular base. The implant was removed through the surgical site. The screw of the implant prosthesis transfer was used to reach the displaced implant. A second implant with the same dimensions as the first one, differing by the external hexagon, was inserted into the same implant site. Therefore, the authors strongly recommend the use of the presented technique prior to osteotomy on mandibular body, reserving the second in the impossibility of reaching the internal connection of the displaced implant.

Study of bone remodeling in corticotomy-assisted orthodontic tooth movement in rats.

The goal of this study was to determine the structure change of the alveolar bone and the expression of a group of bone remodeling-related factors. Sixty healthy male Wistar rats were randomly divided into three groups. Selective alveolar decortication (SAD), tooth movement (TM), and "combined therapy" (SAD+TM) was performed in group I, II, and III, respectively. On days 0, 7, 14, 21, and 42, a Micro-CT scan was performed on the maxillary alveolar bone and tooth. In addition, on days 0, 7, 14, 21, 28, and 42, some of the rats were killed by cervical dislocation and tissues were harvested. Analysis of scan data revealed a significant decrease in bone density of the alveolar bone at 14 days post-surgery, and increased at 42 days post-surgery to a level higher than that before the surgery. Microarray and bioinformatics analysis were performed to explore gene expression profile in three groups (SAD, TM, and SAD+TM),and a large number of differentially expressed genes were identified. In addition, real-time polymerase chain reaction was performed to determine the expression of bone remodeling-related factors. The expression of osteoblast-related cytokines, including osteopontin, bone sialoprotein, and osteocalcin,and osteoclast regulators macrophage-colony stimulating factor (M-CSF) and RANKL (activator of nuclear factor KB receptor ligand) were increased in group III, suggesting that there was increased bone synthesis and activation of bone absorption. Moreover, group III had a unique alveolar bone remodeling pattern: RANKL and osteoprotegerin-promoted alveolar remodeling. In conclusion, during the early stage of orthodontic tooth movement, corticotomy can accelerate the movement of teeth, modulate the state of bone metabolism, and activate osteogenesis and osteoclast, which support the theory of regional acceleratory phenomenon.

Mineral Density Levels in Male and Female Collegiate Cross Country Runners: Is there Reason for Concern?

Introduction: The results of several recent studies have questioned the consequences of high levels of running on bone mineral density (BMD). Elite endurance athletes experience high physiological stress which may negatively impact bone health. Thus, the purpose of this study was to examine the change in BMD in male and female Division I collegiate runners during a competitive Cross Country (CC) season. Methods: T wenty-three (1 1 male and 12 female) Division I collegiate CC runners (ages 18-22 year) were recruited for this study. Total/regional BMD and body composition was determined using dual x-ray absorptiometry. Caloric intake and running mileage was obtained from self-reported diet and training logs. All measures were performed prior to the start (pre) and immediately following (post) a three month collegiate CC season. Results: Males did not demonstrate any significant changes in body composition from pre-post CC whereas females had a significant increase (2.7 ± 1.7 lbs or 2.1%) in total mass, with non-significant increases in fat free and fat mass. From pre- post CC, males did not have any significant changes in bone density whereas females had a statistically significant decrease in bone density of lumbar vertebrae. While no other changes in total or regional BMD were observed, ~ 50% of the both male and female athletes tested in this study had total BMD lower than the age-based reference value. Conclusion: The results of this study suggest that a single competitive CC season can result in a decrease in the lumbar spine BMD in female collegiate distance runners. Moreover, this study revealed that a large percentage (~ 50%) of both male and female distance runners had lower than age-adjusted normal BMD level, raising concerns about long-term bone health in these athletes. Verification of these findings in a larger more diverse population of young athletes is warranted to determine the long term consequences of distance running on bone health.

Vitamin D status and viral response to therapy in hepatitis C infected children.

To study the frequency of vitamin D deficiency in patients with hepatitis C virus (HCV) infection and to evaluate the role of vitamin D supplementation in improving antiviral therapy. Sixty-six children aged from 7-14 years (mean ± SD, 11.17±2.293) diagnosed with HCV infection were matched to 28 healthy controls. Serum levels of 25 (OH) D3, calcium, phosphorus, alkaline phosphatase and plasma level of parathormone were measured. Quantitative PCR for HCV was performed Bone density was determined by dual energy X-ray absorptiometry. All cases received conventional therapy, and only 33 patients received vitamin D supplementation. Children with HCV showed significantly increased levels of HCV RNA (P<0.001), parathormone (P<0.01) and decreased vitamin D levels (P<0.05) (33.3% deficient and 43.3% insufficient) compared with controls. Abnormal bone status (Z score -1.98±0.75) was found in ribs, L-spine, pelvis and total body. Cases treated with vitamin D showed significant higher early (P<0.04) and sustained (P<0.05) virological response. There was a high frequency of vitamin D deficiency among the Egyptian HCV children, with significant decrease in bone density. The vitamin D level should be assessed before the start of antiviral treatment with the correction of any detected deficiency. Adding vitamin D to conventional Peg/RBV therapy significantly improved the virological response and helped to prevent the risk of emerging bone fragility.

Polycystin‐1 stimulates skeletogenesis via TAZ‐mediated activation of RunX2

Polycystin‐1 (PC1) plays an important regulatory role in bone growth and development, as evidenced by decreased bone density found in Pkd1 mutant mice. The activity of the transcription factor RunX2, the master control gene for osteoblast differentiation, is downregulated in Pkd1 mutant mice, suggesting a relationship between PC1 and RunX2. The mechanism of RunX2 activation by PC1, however, has not yet been established. We have shown that the carboxy‐terminal tail of PC1 (PC1‐CTT) is released by a γ‐secretase‐mediated cleavage and traffics to the nucleus, where it regulates the activity of nuclear signaling proteins. Using a novel ‘Co‐Activator Trap’ screen consisting of a library of Gal‐4 tagged transcription factors, the activity of which can be monitored by luciferase production, we identified the transcriptional co‐activator TAZ (Wwtr1) to be highly stimulated by the PC1‐CTT. The PC1‐CTT strongly stimulates RunX2 activity in a TAZ‐dependent manner, and enhances the ability of TAZ/RunX2 to recruit the transcriptional co‐activator p300. Loss of the two Pkd1 alleles in zebrafish results in a significant decrease in bone density, which can be partially rescued with reintroduction of the PC1‐CTT. TAZ is an essential co‐activator of RunX2 activity and may thus represent the missing mechanistic link between PC1 and RunX2.

SURGICAL TREATMENT OF SPINAL DEFORMITIES ASSOCIATED WITH TYPE I NEUROFIBROMATOSIS USING TRANSPEDICULAR FIXATION

The paper presents three cases of surgical treatment for spinal deformities in neurofibromatosis using third-generation segmental instrumentation with transpedicular fixation. Transpedicular fixation provided good clinical effect despite significant decrease in bone density associated with type I neurofibromatosis.

Micro-Computed Tomography and Histologic Evaluation of the Interface of Hydrogel Expander and Underlying Bone: Influence of Pressure Distributors on Bone Resorption

Tissue expanders lead to changes in the underlying bone and can cause bone resorption. We investigated whether the insertion of mechanical devices that distribute the load on the bone can influence these effects. A total of 28 Lewis rats were assigned to 1 of 4 groups. Hydrogel expanders were placed subcutaneously either directly on the calvaria, on titanium mesh, or on a titanium plate. The fourth group of rats served as the controls. The bone quality and thickness were assessed beneath, and at the periphery of, the expanders using micro-computed tomography and histologic examination. Micro-computed tomography images were obtained before and 21 days after insertion. The images revealed a significant decrease in hydroxyapatite density beneath the expanders in the group with only expanders. This decrease was reduced with the use of titanium mesh and completely prevented with the use of titanium plates. Histologic examination revealed a significant decrease in bone density and marked lacunae beneath the hydrogel expanders in the group with only expanders. In contrast, the titanium mesh decreased the size of the lacunae, and the titanium plates completely prevented both the formation of lacunae and the decrease in bone thickness. The bone resorption caused by hydrogel expanders can be diminished using titanium mesh and completely prevented by the insertion of a titanium plate.

Bone density of the femoral neck following Birmingham hip resurfacing

Background Resurfacing is a popular alternative to a standard hip replacement in young arthritic patients. Despite bone preservation around the femoral component, there is little information regarding the bone quality.Patients and methods 32 patients underwent consecutive Birmingham hip resurfacing. The bone density of the femoral neck was measured preoperatively and then at 6 weeks, 3 months, 1 year, and 2 years. The femoral neck was divided into regions of interest. Results were available for 27 hips in 26 patients.Results The overall femoral neck bone density showed a trend towards a decrease at 6 weeks and 3 months but returned to the preoperative level at 1 year, and was maintained at 2 years. The combined superior regions of the neck showed a statistically significant decrease in bone density at 6 weeks and 3 months. This returned to preoperative levels at 1 year and was maintained at 2 years.Interpretation Bone density appears to decrease at 6 weeks and 3 months, suggesting that care is necessary until bone density begins to recover.

Prevention of osteoporosis by angiotensin-converting enzyme inhibitor in spontaneous hypertensive rats

A recent analysis of clinical studies suggests that angiotensin-converting enzyme (ACE) inhibitors might reduce bone fractures. In this study, we examined whether an ACE inhibitor might attenuate osteoporosis in a hypertensive rat model. In spontaneous hypertensive rats (SHRs), estrogen deficiency induced by ovariectomy (OVX) resulted in a significant increase in osteoclast activation as assessed by the tartrate-resistant acid phosphatase (TRAP) activity in the tibia, accompanied by a significant decrease in bone density evaluated by dual-energy X-ray absorptiometry and an increase in urinary deoxypyridinoline. Treatment with an ACE inhibitor, imidapril, attenuated OVX-induced decrease in bone density and increase in TRAP activity and urinary deoxypyridinoline. As ACE inhibitors possess the effects of blockade of the renin-angiotensin system (RAS) and activation of the bradykinin-nitric oxide pathway, we examined the contribution of both pathways in an OVX-induced osteoporosis model. Administration of nitro-L-arginine methylester (L-NAME) did not alter TRAP activity, urinary deoxypyridinoline or bone density, whereas the administration of a subpressor dose of angiotensin II accelerated the increase in TRAP activity in the tibia, accompanied by a significant decrease in bone density and an increase in urinary deoxypyridinoline. Thus, ACE inhibitors prevented osteoporosis, probably because of the inhibition of RAS, but not of nitric oxide. Overall, ACE inhibitors attenuated osteoporosis in a hypertensive rat model through the blockade of RAS.

Site-Specific Deterioration of Trabecular Bone Architecture in Men and Women With Advancing Age

We tested the hypothesis that the age dependence of trabecular bone microstructure differs between men and women and is specific to skeletal site. Furthermore, we aimed to investigate the microstructural pattern of bone loss in aging. Microstructural properties of trabecular bone were measured in vitro in 75 men and 75 age-matched women (age, 52-99 yr) using microCT. Trabecular bone samples were scanned at a 26-microm isotropic resolution at seven anatomical sites (i.e., distal radius, T(10) and L(2) vertebrae, iliac crest, femoral neck and trochanter, and calcaneus). DXA measurements were obtained at the distal radius and proximal femur and QCT was used at T(12). No significant decrease in bone density or structure with age was found in men using microCT, DXA, or QCT at any of the anatomical sites. In women, a significant age-dependent decrease in BV/TV was observed at most sites, which was strongest at the iliac crest and weakest at the distal radius. At most sites, the reduction in BV/TV was associated with an increase in structure model index, decrease in Tb.N, and an increase in Tb.Sp. Only in the calcaneus was it associated with a significant decrease in Tb.Th. In conclusion, a significant, site-specific correlation of trabecular bone microstructure with age was found in women but not in men of advanced age. The microstructural basis by which a loss of BV/TV occurs with age can vary between anatomical sites.

Angiotensin II accelerates osteoporosis by activating osteoclasts

Recent clinical studies suggest that several antihypertensive drugs, especially angiotensin-converting enzyme inhibitors, reduced bone fractures. To clarify the relationship between hypertension and osteoporosis, we focused on the role of angiotensin II (Ang II) on bone metabolism. In bone marrow-derived mononuclear cells, Ang II (1x10(-6) M) significantly increased tartrate-resistant acid phosphatase (TRAP) -positive multinuclear osteoclasts. Of importance, Ang II significantly induced the expression of receptor activator of NF-kappaB ligand (RANKL) in osteoblasts, leading to the activation of osteoclasts, whereas these effects were completely blocked by an Ang II type 1 receptor blockade (olmesartan) and mitogen-activated protein kinase kinase inhibitors. In a rat ovariectomy model of estrogen deficiency, administration of Ang II (200 ng/kg/min) accelerated the increase in TRAP activity, accompanied by a significant decrease in bone density and an increase in urinary deoxypyridinoline. In hypertensive rats, treatment with olmesartan attenuated the ovariectomy-induced decrease in bone density and increase in TRAP activity and urinary deoxypyridinoline. Furthermore, in wild-type mice ovariectomy with five-sixths nephrectomy decreased bone volume by microcomputed tomography, whereas these change was not detect in Ang II type 1a receptor-deficient mice. Overall, Ang II accelerates osteoporosis by activating osteoclasts via RANKL induction. Blockade of Ang II might become a novel therapeutic approach to prevent osteoporosis in hypertensive patients.

Longitudinal evaluation of perimenopausal bone loss: Effects of different low dose oral contraceptive preparations on bone mineral density

Objectives To evaluate the pattern of mineral density in eumenorrhoic and oligomenorrhoic perimenopausal women, and assess the effects of different low dose oral contraceptives (OC) on bone metabolism and spine bone density. Methods Spine bone density was evaluated in a longitudinal 2-year follow-up, randomized, unblinded, uncontrolled clinical trial conducted in healthy, normally menstruating perimenopausal women, perimenopausal oligomenorrhoic women and in perimenopausal oligomenorrhoic women treated with an oral contraceptive containing 20 mcg ethinyl estradiol plus 0.15 mg desogestrel, 0.100 mg levonorgestrel, 0.75 mg of gestodene ( n = 15 in each group). The results were analyzed by factorial or repeated measures analysis of variance, as appropriate. Results During the observation period, in normal menstruating women there were no changes in menstrual cycle, plasma FSH and estradiol levels, and spine bone density. In oligomenorrhoic untreated women an increase in cycle length, with a concomitant decrease in plasma estradiol and an increase in plasma FSH levels were evidenced ( p < 0.05). In this group a significant decrease in bone density ( p < 0.05) occurred. In OC-treated women, a significant ( p < 0.05) increase in bone density was observed, with no differences among different groups. Conclusion Different progestins used in OC preparations do not modify the bone sparing effect of perimenopausal OC administration avoiding the decrease in bone density.