Effect Of Bone Loss Research Articles

Koumine inhibits RANKL-induced ubiquitination and NF-κB activation to prevent ovariectomy and aging-induced bone loss.

Osteoporosis (OP) is a bone remodeling disease characterized by an imbalance between bone resorption and formation. Osteoclasts are the primary therapeutic targets for treating bone destruction. Koumine (KM), the most bioactive component in Gelsemium alkaloids, exhibits antitumor, immunosuppressive, anti-inflammatory, and analgesic properties. However, the effects of bone loss have not been well studied. This study conducted in vitro and in vivo verification experiments on KM. The results showed that KM inhibited bone resorption and tartrate-resistant acid phosphatase positive (TRAP+) osteoclasts development by mature osteoclasts in a dose-dependent manner. Moreover, KM prevented OVX-induced OP in vivo and potentially inhibited ubiquitination, a process closely related to various biological activities, including protein interaction, transcription, and transmembrane signal transduction regulation, especially within the nuclear factor-κB (NF-κB) pathway. Previous studies have demonstrated that several proteins ubiquitination promotes osteoclastogenesis, our study indicated that KM inhibits early NF-κB activation and receptor activator of NF-κB ligandinduced ubiquitination, a critical factor in osteoclast differentiation. In conclusion, our research suggests that KM holds potential as an effective therapeutic agent for OP.

Pantoprazole-Induced Bone Loss through Gastrin Secretion: A Stereological Study.

Recent researches have failed to uncover a clear explanation for proton pump inhibitors' bone-loss effects. In light of pantoprazole's effects on gastrin secretion, the goal of this study was to see if it caused bone loss through gastrin secretion. Forty male rats were divided into control, octreotide (Oct), pantoprazole (Pan), and pantoprazole plus octreotide (Pan+Oct) groups. Serum calcium, phosphorous, alkaline phosphatase, parathyroid hormone, and gastrin were measured before and three months after the treatment, and bone densitometry was examined. The rats' femoral bones were examined stereologically at the end of the investigation. The Pan group had considerably greater levels of serum alkaline phosphatase, parathyroid hormone (PTH), and gastrin, but this was prevented in the presence of Oct, a gastrin secretion inhibitor. All parameters of femoral bone densitometry in the Pan group were significantly lower than the control after treatment which was considerably inhibited in the presence of Oct. Furthermore, when compared to the control and Oct groups, the rats in the Pan group had a lower trabecular volume, femur bone weight, and volume, as well lower number of osteocytes. The amount of osteoclasts, on the other hand, was much higher in the Pan group than in the other groups. Overall findings revealed that pantoprazole caused bone loss, which could be prevented by adding octreotide. Because these detrimental effects were not detected in rats given both Oct and Pan, it was suggested that the effect of Pan on bone was produced by a hypergastrinemic condition.

Assessment of non-traumatic vertebral fractures in Cushing’s syndrome patients

Hypercortisolism has detrimental effects on bone metabolism with the consequences of bone loss and bone fractures. We aimed to evaluate the frequency of vertebral fragility fractures and to determine the factors associated with Cushing's syndrome (CS). A total of 135 patients diagnosed with Cushing's syndrome [108 patients with Cushing's disease and 27 patients with adrenocortical adenoma] and 107 healthy controls were included in this cross-sectional study. The available clinical, laboratory, and radiologic data of patients with CS were recorded, retrospectively. Lateral vertebral radiograms were evaluated for vertebral fragility fractures according to Genant's semi-quantitative method. Bone mineral density (BMD) was determined using a Dual-energy X-ray absorptiometry (DEXA). Vertebral fragility fractures (VFs) were observed in 75.3% (n = 61) of the patients. The median number of VFs was six (min-max: 2-12). All patients with vertebral fractures had thoracic VF, and 50.7% of the patients had lumbar fragility fractures. Thirty-three (40.7%) patients with vertebral fractures had normal bone densitometry values. Osteoporosis and osteopenia were observed in 16.2% and 40.7% of the patients, respectively. The duration of active disease, the presence of ACTH-secreting pituitary adenoma, and 24-h urinary cortisol did not influence the presence of vertebral fractures. Vertebral fractures were independently associated with age, FSH, LH levels, and lumbar BMD (R2 = 68.18%, p = 0.028). The femoral neck BMD (but not lumbar BMD) was independently associated with age, BMI, and PTH levels (R2 = 48.48%, p < 0.001). Vertebral fracture frequency was higher in CS patients. Most of the patients with vertebral fractures had multiple fractures. Although low lumbar BMD was associated with VF, patients with CS with normal bone densitometry could experience VF. Vertebral radiograph evaluations as a part of routine evaluation for silent vertebral fractures may help to prevent further fractures in patients with CS.

Effect of bone loss on the fracture resistance of narrow dental implants after implantoplasty. An in vitro study.

Background Implantoplasty (IP) involves polishing of the exposed surface of implants affected by peri-implantitis (PI). A study was made to determine whether the degree of bone loss influences the fracture resistance of implants with or without IP.Material and Methods An in vitro study was carried out on 32 narrow (3.5 mm) dental implants with a rough surface and external hexagonal connection. Implantoplasty was performed in half of the implants of the sample. Both the IP and control implants were divided into two subgroups according to the amount of bone loss (3 mm or 7.5 mm). Standardized radiographic assessment of implant width was performed using specific software. The main outcome variable was the maximum compression force (Fmax) of implants when subjected to static resistance to fracture tests. Implant fractures were subsequently analyzed by scanning electron microscopy. A descriptive and bivariate analysis of the data was performed.Results Significant changes in implant width were observed after IP (p<0.05). No significant differences between IP and control implants were recorded in terms of the Fmax values in the two bone loss subgroups (3 mm: control 854.37N 195.08 vs. IP 752.12N 186.13; p=0.302, and 7.5 mm: control 548.82N 80.02 vs. IP 593.69N 111.07; p=0.370). Greater bone loss was associated to a decrease in Fmax, which proved significant for the control implants (p=0.001). Fractures were more frequently located in the platform (n=13).Conclusions Implants with more apical bone levels appear to be more susceptible to fracture. On the other hand, IP does not seem to significantly decrease the fracture resistance of narrow (3.5 mm) platform dental implants with external hexagonal connections. The fact that most fractures occur in the platform area indicates that the latter is exposed to more mechanical stress. Key words:Peri-implantitis, dental implants, compressive strength, titanium, implantoplasty.

Outcomes After Revision Anterior Shoulder Stabilization: A Systematic Review.

Background:Primary shoulder stabilization is successful, but there continues to be a risk of recurrence after operative repair, particularly in the young athlete. It is important for surgeons to understand the outcomes after various revision stabilization techniques to best counsel patients and manage expectations.Purpose:To analyze recurrent instability and revision surgery rates in patients who underwent revision anterior glenohumeral stabilization procedures with either arthroscopic repair, open repair, coracoid transfer, free bone block, or capsular reconstruction.Study Design:Systematic review; Level of evidence, 4.Methods:We performed a systematic review of level 2 to 4 evidence studies using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Clinical studies of revision anterior glenohumeral stabilization (arthroscopic repair, open repair, coracoid transfer, free bone block, or capsular reconstruction) with a minimum 2-year follow-up were analyzed. The rate of recurrent instability, rate of revision surgery, patient-reported outcomes, and range of motion were extracted and reported. Study methodological quality was evaluated using the Downs and Black quality assessment score.Results:A total of 37 studies met inclusion criteria and were available for analysis: 20 studies evaluated arthroscopic repair, 8 evaluated open repair, 5 evaluated Latarjet procedure, 3 evaluated bone block, and 2 evaluated capsular reconstruction. There was 1 study included in both arthroscopic and Latarjet procedures, for a total of 1110 revision cases. There was 1 level 2 study, and the remainder were level 3 or 4 with poor Downs and Black scores. Participants analyzed were most commonly young (weighted mean age, 26.1 years) and male (78.4%). The weighted mean clinical follow-up after revision surgery was 47.8 months. The weighted mean rate of recurrent instability was 3.8% (n = 245) after the Latarjet procedure, 13.4% (n = 260) after open repair, 16.0% (n = 531) after arthroscopic repair, 20.8% (n = 72) after bone block, and 31.0% (n = 35) after capsular reconstruction. The weighted mean rate of additional revision surgery was 0.0% after bone block, 0.02% after the Latarjet procedure, 9.0% after arthroscopic repair, 9.3% after open repair, and 22.8% after capsular reconstruction. Patient-reported outcomes and objective measures of range of motion and strength improved with all revision techniques.Conclusion:The current review identifies a deficiency in the literature pertaining to consistent meaningful outcomes and the effect of bone loss after revision shoulder stabilization. Published studies demonstrate, however, that revision shoulder stabilization using arthroscopic, open, coracoid transfer, or bone block techniques yielded satisfactory objective and patient-reported outcomes. The Latarjet procedure exhibited the lowest recurrent instability rate. This study confirms that recurrent instability remains a common problem, despite revision shoulder stabilization. The quality of research in revision shoulder stabilization remains poor, and higher quality studies are needed to establish best practices for treatment of this complex problem.

Akt drives buffalo casein-derived novel peptide-mediated osteoblast differentiation

Milk is a potential nutraceutical with wide range of bioactive compounds that are antioxidative, antimicrobial, antithrombotic, immunomodulatory, opioid and antihypertensive. Various intervention studies with milk reflect its stupendous role in elevating bone mineral density. Milk and milk products have shown a preventive effect in bone loss during pre- and postmenopausal women. Since, milk is proved to have a vital role in bone health promotion, there is a need to identify bioactive compounds within it. Recently we have reported four novel peptides from milk casein for their osteoblast proliferation activity. Their role in differentiation and the signaling cascade evoked by them have not been studied. Thus, the present study has been designed to investigate the differentiation potential and signaling cascade of one of the novel peptides, that is, NAVPITPTL by analyzing osteoblast differentiation markers such as alkaline phosphatase activity, osteocalcin and mineral deposition. All the experimentations suggested a significant role of this peptide in osteoblast differentiation. The inhibitor studies, immunocytochemistry and immunoblotting have proven that the peptide-induced differentiation through pAkt signaling cascade as pAkt was observed in nucleus. Moreover, the peptide was found to be bioaccessible up to 1%.

Prognosis of implant longevity in terms of annual bone loss: a methodological finite element study

Dental implant failure is mainly the consequence of bone loss at peri-implant area. It usually begins in crestal bone. Due to this gradual loss, implants cannot withstand functional force without bone overload, which promotes complementary loss. As a result, implant lifetime is significantly decreased. To estimate implant success prognosis, taking into account 0.2 mm annual bone loss for successful implantation, ultimate occlusal forces for the range of commercial cylindrical implants were determined and changes of the force value for each implant due to gradual bone loss were studied. For this purpose, finite element method was applied and von Mises stresses in implant–bone interface under 118.2 N functional occlusal load were calculated. Geometrical models of mandible segment, which corresponded to Type II bone (Lekholm & Zarb classification), were generated from computed tomography images. The models were analyzed both for completely and partially osseointegrated implants (bone loss simulation). The ultimate value of occlusal load, which generated 100 MPa von Mises stresses in the critical point of adjacent bone, was calculated for each implant. To estimate longevity of implants, ultimate occlusal loads were correlated with an experimentally measured 275 N occlusal load (Mericske-Stern & Zarb). These findings generally provide prediction of dental implants success.

Female Adolescent Athletes’ Awareness of the Connection between Menstrual Status and Bone Health

Study Objective The aims of this study are to determine among female high school track athletes: (1) knowledge of the association between menstrual irregularity and bone health; (2) attitudes toward amenorrhea, specifically if amenorrhea is seen as a sign of athletic success; (3) the association between knowledge and attitudes based on athlete menstrual status. Design Cross-sectional survey. Setting Five public high schools in Texas. Participants 103 female high school track athletes ages 14–18 years. Intervention Participants completed a questionnaire that addressed menstrual history, details of track participation, knowledge of bone mineral density (BMD)/ menstrual status connection, and attitudes about the desirability of oligo/amenorrhea. Outcome Measures Frequencies of attitude and knowledge replies, summative knowledge score, and correlations between attitudes, knowledge, and menstrual status. Results Sixteen subjects (16.7%) met criteria for amenorrhea, 16 for oligomenorrhea (16.7%). Median summative knowledge score was one of six. Menstrual irregularity was associated with lower knowledge ( P = 0.035). Incorrect answers about consequences of bone loss and the link to menstrual irregularity were given by ≥90% of respondents. Lower knowledge was associated with a greater number of “don’t know” replies to attitude questions ( P = 0.002). Among more knowledgeable participants endorsing opinions, menstrual irregularity was not seen as a sign of athletic success. Conclusions The prevalence of irregular menses is high among adolescent track athletes and a larger-scale inquiry to clarify adolescent athletes’ knowledge of and attitudes about the link between menstrual patterns and BMD is indicated. Education may provide one key to improved health behavior among this at-risk population.

The effect of bone loss on rod-like and plate-like trabeculae in the cancellous bone of the mandibular condyle

Bone loss may affect the structure of cancellous bone. But its effect on trabeculae with different characteristics, like rods and plates, is not accurately known. This study analyzes the effect of bone loss on individual rod-like and plate-like trabeculae. 94 specimens were obtained from mandibular condyles from both dentate and edentate humans and scanned with a micro-CT scanner. The bone volume fraction (BV/TV) of these specimens ranged from 7% to 30%. Next, the rod-like and plate-like trabeculae were identified with an especially developed algorithm. Plate volume fraction (PV/TV), rod volume fraction (RV/TV), plate thickness, rod thickness, number of plates, and number of rods were determined. In individual specimens, the thickness of the rods ranged from 40 μm to 180 μm, while the thickness of the plates ranged from 40 μm to 300 μm. In every specimen, the thickness of the plates was larger than the thickness of the rods. Statistical analysis revealed that PV/TV was proportional ( r = 0.98, P < 0.001) and RV/TV inversely proportional ( r = −0.45, P < 0.001) to BV/TV. Also the thickness of the plates correlated with BV/TV ( r = 0.62, P < 0.001), while the thickness of the rods (mean = 90 μm, SD = 7 μm) remained constant ( r = −0.09, P = 0.378). A four-fold reduction of the bone volume fraction was accompanied by a three-fold reduction of the number of plates and a 40% reduction of their thickness, but also by a three-fold increase in the number of rods and RV/TV. It was concluded that the effect of bone loss on plate-like trabeculae was opposite to its effect on rod-like trabeculae. Remarkably, the thickness of the rods (90 μm) was independent of the bone volume fraction. This suggests that there is a minimal thickness for trabeculae.

L’ostéoporose cortisonique

A FREQUENT PRESCRIPTION: Corticosteroids are widely prescribed in the long-term treatment of various pathologies (chronic inflammatory rheumatic diseases, asthma and allergic diseases, auto-immune diseases...). CONSEQUENCE OF BONE LOSS: Corticosteroids can be responsible for side effects such as corticosteroid-induced osteoporosis and the increase in risk of fracture is one of the major problems. Great progress in the field of epidemiology, diagnosis, physiopathology and treatment has led to the elaboration of rational and efficient care of patients receiving corticosteroids.

Strategies for the prevention of senile (type II) osteoporosis: an update.

Hip fractures in the elderly represent a global issue, associated with significant morbidity and mortality. Considering the magnitude of the problem, any substantial reduction in the hip fracture burden depends on prevention. In view of the complex pathogenesis of senile (type II) osteoporosis, preventive strategies should focus on the frequency of falling in the elderly as well as on the prevalence of compromised femoral integrity as a consequence of bone loss. Although many risk factors for senile osteoporosis are potentially preventible or reversible with targeted interventions, the beneficial effects of most strategies have not yet been adequately documented, indicating the need for additional long-term controlled studies.