جستجوی مقالات مرتبط با کلیدواژه "bone formation" در نشریات گروه "پزشکی"

Mammals have limited limb regeneration compared to amphibians. The role of Wnt signaling pathways in limb regeneration has rarely been studied. So, this study aimed to investigate the effect of Wnt-signaling using chemicals CHIR99021 and IWP-2 on amputated mice digit tips regeneration in an in vitro organ culture system.

The distal phalanx of paws from C57BL/6J mouse fetuses at E14.5, E16.5, and E18.5 was amputated. Then, the hands were cultured for 7 days. Subsequently, paws were treated with 1–50 µg/ml concentration of CHIR99021 and 5–10 µg/ml concentration of IWP-2. Finally, the new tissue regrowth was assessed by histological analysis, immunohistochemistry for BC, TCF1, CAN, K14, and P63 genes, and beta-catenin and Tcf1 genes were evaluated with RT-qPCR. 

The paws of E14.5 and E16.5 days were shrinkaged and compressed after 7 days, so the paws of 18.5E that were alive were selected. As a result, newly-grown masses at digit tips were observed in 25 and 30 µl/ml concentrations of the CHR99021 group but not in the IWP2 treatment (*P<0.05; **P<0.01). qRT-PCR analysis confirmed the significant up-regulation of beta-catenin and Tcf1 genes in CHIR99021 group in comparison to the IWP-2 group (P<0.05). Moreover, Alcian-blue staining demonstrated the presence of cartilage-like tissue at regenerated mass in the CHIR group. In immunohistochemistry analysis beta-catenin, ACN, Keratin-14, and P63 protein expression were observed in digit tips in the CHIR-treated group.  

By activating the Wnt signaling pathway, cartilage-like tissue formed in the blastema-like mass in the mouse’s amputated digit tips.

On chronic exposure, Lead (Pb) deposits in the skeletal system, replaces calcium ions, and alters the normal physiological processes, which in turn, lead to stunting, delayed fracture healing, and high resorption of collagen molecules. The present study aimed to assess the association of musculoskeletal pain and discomfort with bone turnover markers (BTMs) among long-term Pb-exposed workers. Study design: A cross-sectional study.

The study recruited 176 male Pb-exposed workers and 80 control subjects who were matched for age, gender, and socio-economic status. Blood lead levels (BLLs), bone growth markers, such as serum osteocalcin (OC), alkaline phosphatase (ALP), bone alkaline phosphatase (BAP), and bone resorption markers: serum pyridinoline (Pry), deoxypyridinoline (DPry), tartrateresistant acid phosphatase-5b(TRACP-5b), and hydroxyproline in urine (HyP-U) of participants were investigated. Pain and discomfort in the musculoskeletal system were assessed using Nordic Musculoskeletal Questionnaire.

Pb-exposure was significantly associated with musculoskeletal discomfort of the lower back (P<0.001), upper back (P<0.001), and ankle/foot (P=0.011). Among bone formation markers, serum OC was significantly lower in musculoskeletal discomfort of elbows (P=0.033) and ankle/foot (P=0.042). Among bone resorption markers, serum DPry was significantly lower in musculoskeletal discomfort of the neck (P=0.049) and shoulders (P=0.023). HyP-U was significantly higher in musculoskeletal discomfort of shoulders (P=0.035) and lower back (P=0.036).

As evidenced by the obtained results, Pb-exposure was associated with musculoskeletal discomfort of the lower back, upper back, and ankle/foot. Lower bone formation (serum OC) marker was noted with musculoskeletal discomfort of elbows and ankle/foot. Furthermore, bone resorption markers were associated with musculoskeletal discomfort of the neck, shoulders, and lower back. The findings of the present study suggested that long-term Pbexposure and BTMs were associated with musculoskeletal discomfort.

The collagen membrane which obtained from bovine pericardium and human skin in Guided Bone Regeneration (GBR) is costly and may even cause transmission of diseases. Replacing conventional collagen membranes with a more easily accessible and cheaper ones will have economic benefits. The aim was to determine the osteogenic effect of collagen‑membrane derived from Rutilus kutum swim bladder on rat calvaria.

The study was experimental. Thirty‑six male albino rats of the Wistar strain were included in the study. The 5 mm surgical defects were created on calvarias and filled with allograft bone material and covered by R. kutum swim bladder (Group I), bovine derived pericardial membrane (Group II) and without membrane cover(Group III).The specimen were euthanized after 3, 5 and 8 weeks. The surrounding connective tissue was evaluated in term of osseous formation. Kruskal–Wallis, Univariant analysis of variance, and post hoc tests were used for statistical analysis. The P < 0.05 was considered statistically significant.

A significant differences between groups in terms of osseous formation (P = 0.001) was noted. The difference of osseous formation was significantly higher in 5 and 8 weeks than 3 weeks after operation in all groups (P = 0.03 and P = 0.006, respectively). The osseous formation in Group I and II were significantly higher than Group III (P = 0.023 and P = 0.001).

The R.kutum swim bladder had osteogenic effect on rat calvaria. R.kutum swim bladder can be a new source in natural derived collagen membrane in GBR.

Multiple osteoma cutis is a rare skin disorder characterized by tiny bone fragments deposition in the skin. It is a benign disease, which occurs as primary or secondary forms. Secondary osteoma cutis most commonly appears on the facial acne scars in middleaged women. The exact etiology of this phenomenon is unknown, but it may be induced by osteoblastic metaplasia of mesenchymal elements.

Herein, we report a 70-year-old man with a history of multiple basal cell carcinoma (BCC) of the scalp caused by radiotherapy, who referred to our tumor clinic with multiple skin-colored subcutaneous papules and nodules on his scalp from 2 years ago along with cutaneous side effect changes of radiodermatitis. In the histological examination of lesions with differential diagnosis of BCC, cysts, and adnexal tumors, the diagnosis of osteoma cutis was established without any evidence of BCC.

Osteoma cutis is a rare disorder most commonly affecting the face, but our patient had multiple lesions of the scalp. The inflammatory changes of radiodermatitis may be the principal cause of this change.

Autogenous bone grafts are considered the gold standard although they have several disadvantages, leading to a search for suitable alternative graft biomaterials. This study evaluates the histological and histomorphometric properties of regenerated bone in defects in rabbits following the application of two commercially available xenografts (Bio-Oss and Osteon).

This animal study was carried out on 14 New Zealand rabbit calvaria. Four 6.5-mm critical-size defect (CSD) models of bone regeneration were formed in each surgical site. The first defect was filled with Bio-Oss, the second with large Osteon (L-Osteon), the third with small Osteon (S-Osteon), and the last one remained unfilled (the control group). The cases were sacrificed. Bone forming properties (amount of new bone formation, inflammation, and foreign body reaction) were observed at 4- and 8-week intervals through histological and histomorphometric examinations. The Friedman test, Kruskal-Wallis test, and Wilcoxon test for multiple comparisons were used for data analysis. The level of statistical significance was set at 0.05.

There was no statistically significant difference for regenerated bone among the four groups (P>0.05). The L-Osteon site showed more inflammation and foreign body reaction compared to the other groups. 

The results of this study showed that Bio-Oss and Osteon appear to be highly biocompatible and osteoconductive and can thus successfully be used as bone substitutes in augmentation procedures.

Repair of bone defects is challenging for reconstructive and orthopedic surgeons. In this study, we aimedto histomorphometrically assess new bone formation in tibial bone defects filled with octacalcium phosphate (OCP),bone matrix gelatin (BMG), and a combination of both. A total of 96 male Sprague Dawley rats aged 6-8 weeks weighing 120-150 g were randomly allocatedinto three experimental (OCP, BMG, and OCP/BMG) and one control group (n=24 in each group). The defects inexperimental groups were filled with OCP (6 mg), BMG (6 mg), or a combination of OCP and BMG (6 mg, 2:1 ratio).No material was used to fill the defects in the control group and the defect was only covered with Surgicel. Sampleswere taken on days 7, 14, 21, and 56 after the surgery. The sections were stained with hematoxylin-eosin (H&E) andassessed using light microscopy. In our experimental groups, bone formation was started from the margins of the defect towards the centerwith an increasing rate during the study period. Moreover, the formed bone was more mature. Bone formation in ourcontrol group was only limited to the margins of the defect. The newly formed bone mass was significantly higher inthe experimental groups (P=0.001). OCP, BMG, and OCP/BMG compound enhanced osteoinduction in long bones.Level of evidence: III

Cadmium is one of the heavy metals with harmful effects on different body organs and systems. The aim of this study was to investigate the harmful effects of cadmium, as a heavy metal, on the histological structure of bone and the expression of osteocalcin gene. Forty chickens were obtained, anesthetized and their femurs were surgically removed. The real time polymerase chain reaction (PCR) was used to study the osteocalcin gene expression. The osteocalcin gene expression rate were: 1.000± 0.1; 0.86± 0.01; 0.63± 0.09, and 0.41± 0.06 in the controls, experiment I, experiment II and experiment III groups, respectively (P < 0.05). Also, the nuclear pyknosis in osteocytes and decreased bone formation were observed in the histology slides of the chicken bones. We conclude that cadmium adversely affected the chicken bones as evident by the decreased osteocalcin gene expression and the adverse effects on the bone histology. We recommend that plans be developed to prevent the outbreak of cadmium and other heavy metals in animal and human environment.

Some recent studies have proven that an association between inhaled glucocorticostroid and osteoporosis in asthma patients. The present study aimed to evaluate the effect of aerobic training program on serum osteocalcin and alkaline phosphatase as formation bone indicators in asthma patients.
In this semi-experimental study, twenty four sedentary middle-aged asthma males treatment with inhaled glucocorticostroid aged 38 ± 6 years; BMI, 31.5 ± 3 kg/m2 were randomized to aerobic training (n = 12) and control (n = 12) groups. Fasting blood samples (8:00 - 9:00 a.m.) were collected from the antecubital vein before and after aerobic training for measure serum osteocalcin and alkaline phosphatase of 2 groups. Anthropometrical markers were also measured in all subjects before and after training program. The exercise program consisted of 40 - 60 minutes on treadmill at intensity range of 55 - 75 (%) of maximal heart rate, 3 times per week for 3 months. Student’s t-tests (Version 15.0, SPSS Inc., IL, USA) were performed to determine whether there were significant within-group changes in the outcomes.
Aerobic intervention improved anthropometric parameters (P Based on these results, our finding indicates that a regular aerobic exercise program is a compensation intervention for osteoporosis in asthma patients with inhaled glucocorticostroid.

Efforts are being made to improve the efficacy of biomaterials used as bone substitutes for bone regeneration in the oral and maxillofacial region. Graft materials have been recently produced in Iran; however, studies are required to confirm their efficacy. This study aimed to compare the histomorphometric results of using mineralized allografts produced by the Hamanandsaz Baft Kish Company and the Iranian Tissue Bank (ITB) for regeneration of rabbit calvarial bone defects.
In this animal study, four similar holes with a minimum diameter of 6.5 mm were created in the calvaria of 14 white New Zealand rabbits. The defects were filled with Cenobone (Hamanandsaz Baft Kish Co.), ITB product and Cerabone (Botiss Co). One defect remained unfilled as the control group. One and two months after implantation, the animals were sacrificed and the defects was subjected to histologic and histomorphometric assessments. The amount of new bone formation and the volume of remaining biomaterials were analyzed using one-way ANOVA. The inflammatory reaction was analyzed by the Kruskal Wallis test and the foreign body reaction, bone quality and bone-graft interface pattern were analyzed using the Fisher’s exact test.
The amount of new bone formation was 0.060.1± and 0.11± 0.1, 0.040.08± and 0.110.09±, and 0.080.12± and 0.090.06± mm2 in the ITB, Cerabone and Cenobone groups at one and two months post-implantation, respectively.
The effect of time and type of biomaterial on the amount of new bone formation was not significant. At one month, significant differences were seen in the amount of remaining biomaterials in the defects among the three groups (P Bone allografts such as Cenobone and ITB had optimal efficacy for bone regeneration in rabbit calvarial defects comparable to that of Cerabone xenograft. Considering the limitations of in vitro studies, application of these biomaterials must be evaluated in clinical studies.

Heterotopic ossification (HO) is a complication after spinal cord injury. There are limited studies evaluating hip ossification in Iranian patients with spinal cord injury.. We designed this study to evaluate prevalence of HO in cases with spinal cord injury and clinical factors related to this finding..Patients and In this study, 135 patients with traumatic spinal cord injury who were referred to a spinal cord injury clinic were enrolled. A structured questionnaire was used to collect data. Hip radiography was performed for all patients to evaluate hip ossifications. An expert radiologist assessed the obtained radiographs.. Thirty one (23%) participants were women and 104 (77%) were men. The most common cause of injury was accident (66.7%) followed by falling (28.1%). HO was present in 51 (37.8%) cases, and hip X-ray was normal in 84 (62.2%) Duration of injury and bed sore were significantly higher in patients with HO. Logistic regression analysis considering HO as a dependent variable showed that only bedsore was an independent predictor of HO.. Evaluation for hip ossification should be considered in patients with spinal cord injury..

The presence of certain oral pathogens at implant sites can hinder the osseointegration process. However, it is unclear how and by what microorganisms it happens.. This study investigated whether the presence of oral pathogens of Porphyromonas gingivalis and Prevotella intermedia individually, play a role in the failure of bone formation by determining the expression profiles of Transforming Growth Factor Beta (TGF-β/Bone Morphogenic Protein (BMP) and Toll-Like Receptor (TLR) pathways in challenged osteoblasts.. Cell viability of P. gingivalis and P. intermedia challenged osteoblasts were determined by WST assay. Changes in osteoblast morphology and inhibition of mineralization were observed by Scanning Electron Microscopy (SEM) and Von Kossa staining, respectively. Expression of TGF-β and TLR pathway genes on challenged cells were identified by RT profiler array. Both P. gingivalis and P. intermedia challenges resulted in reduced viability and mineralization of osteoblasts.. Viability was reduced to 56.8% (P. gingivalis) and 52.75% (P. intermedia) at 1000 multiplicity. Amongst 48 genes examined, expressions of BMPER, SMAD1, IL8 and NFRKB were found to be highly upregulated by both bacterial challenges (Fold Change > 4).. P. gingivalis and P. intermedia could play a role in implant failure by changing the expression profiles of genes related to bone formation and resorption..

The purpose of this study was to perform a histological, histomorphometrical, and immunohistochemical evaluation of the effect of Enamel matrix derivative (EMD) on bone formation around titanium dental implant. In this animal study, 12 implants (10 × 3.8 mm) were inserted in the tibia bone of three dogs of Iranian breed. Two implants were placed in each tibia with EMD only on the left side. The dogs were sacrificed 2, 4, and 6 weeks after implantation. Following decalcification of the implants’ surrounding tissue and preparation of 4 μm thick sections, they were stained with hematoxylin and eosin (H and E) and immunohistochemical (IHC) stain for osteopontin (OPN) marker. Histomorphometric evaluation was performed via measurement of the percentage of the woven, lamellar, and total generated bone. Light microscopy osteoblastic intensity of OPN in osteoblasts and bone matrix was also evaluated Data were analyzed by Wilcoxon signed Ranks, and Mc Nemar tests. In both control and EMD‑applied groups, bone formation was recognized around the implants at the 4th week postimplantation. The percentage of total generated bone in the test group was higher than the control group, although being not statistically significant (P value = 0.917).Osteoclasts exhibited significantly higher proliferation activity compared the control group when stimulated by EMD (P value = 0.027). On average, the staining intensity in osteoblasts and extracellular matrix of bone, in EMD‑applied subjects was higher than those of the controls (P value = 0.167 and P value = 0.414, respectively). EMD enhanced bone formation around dental implants, but this increase was not significant.