Displaying publications 1 - 20 of 249 in total

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  1. Chin KY, Pang KL, Mark-Lee WF
    Int J Med Sci, 2018;15(10):1043-1050.
    PMID: 30013446 DOI: 10.7150/ijms.25634
    Bisphenol A (BPA) is an endocrine disruptor which can bind to the oestrogen receptor. It also possesses oestrogenic, antiandrogenic, inflammatory and oxidative properties. Since bone responds to changes in sex hormones, inflammatory and oxidative status, BPA exposure could influence bone health in humans. This review aimed to summarize the current evidence on the relationship between BPA and bone health derived from cellular, animal and human studies. Exposure to BPA (0.5-12.5 µM) decreased the proliferation of osteoblast and osteoclast precursor cells and induce their apoptosis. Bisphenol AF (10 nM) enhanced transforming growth factor beta signalling but bisphenol S (10 nM) inhibited Wnt signalling involved in osteoblast differentiation in vitro. In animals, BPA and its derivatives demonstrated distinct effects in different models. In prenatal/postnatal exposure, BPA increased femoral bone mineral content in male rats (at 25 ug/kg/day) but decreased femoral mechanical strength in female mice (at 10 µg/kg/day). In oestrogen deficiency models, BPA improved bone mineral density and microstructures in aromatase knockout mice (at very high dose, 0.1% or 1.0% w/w diet) but decreased trabecular density in ovariectomized rats (at 37 or 370 ug/kg/day). In contrast, bisphenol A diglycidyl ether (30 mg/kg/day i.p.) improved bone health in normal male and female rodents and decreased trabecular separation in ovariectomized rodents. Two cross-sectional studies have been performed to examine the relationship between BPA level and bone mineral density in humans but they yielded negligible association. As a conclusion, BPA and its derivatives could influence bone health and a possible gender effect was observed in animal studies. However, its effects in humans await verification from more comprehensive longitudinal studies in the future.
    Matched MeSH terms: Bone and Bones/drug effects*
  2. Chai, W.L.
    Ann Dent, 2009;16(1):24-30.
    MyJurnal
    This systematic review focuses on the management of two types of osseous defects, i.e. dehiscence and fenestration that arise during the placement of dental implant in the edentulous area (delayed implant placement). A systematic online search of main database from 1975 to 2009 was made. Five randomised controlled trials have been identified based on the inclusion criteria. Different management procedures were identified, in which guided bone regeneration procedure was most commonly advocated. Resorbable and non-resorbable m'embranes were compared, in which resorbable membrane was preferred as it caused less complicatiQn of membrane exposure or risk of infection. The benefit of using bone substitute along with membrane in rypairing bony defects cannot be concluded.
    Matched MeSH terms: Bone and Bones
  3. Vafa E, Tayebi L, Abbasi M, Azizli MJ, Bazargan-Lari R, Talaiekhozani A, et al.
    Environ Sci Pollut Res Int, 2023 Nov;30(55):116960-116983.
    PMID: 36456674 DOI: 10.1007/s11356-022-24176-1
    The introduction of bioactive glasses (BGs) precipitated a paradigm shift in the medical industry and opened the path for the development of contemporary regenerative medicine driven by biomaterials. This composition can bond to live bone and can induce osteogenesis by the release of physiologically active ions. 45S5 BG products have been transplanted effectively into millions of patients around the world, primarily to repair bone and dental defects. Over the years, many other BG compositions have been introduced as innovative biomaterials for repairing soft tissue and delivering drugs. When research first started, many of the accomplishments that have been made today were unimaginable. It appears that the true capacity of BGs has not yet been realized. Because of this, research involving BGs is extremely fascinating. However, to be successful, it requires interdisciplinary cooperation between physicians, glass chemists, and bioengineers. The present paper gives a picture of the existing clinical uses of BGs and illustrates key difficulties deserving to be faced in the future. The challenges range from the potential for BGs to be used in a wide variety of applications. We have high hopes that this paper will be of use to both novice researchers, who are just beginning their journey into the world of BGs, as well as seasoned scientists, in that it will promote conversation regarding potential additional investigation and lead to the discovery of innovative medical applications for BGs.
    Matched MeSH terms: Bone and Bones
  4. Mohamad NV, Soelaiman IN, Chin KY
    Clin Interv Aging, 2016;11:1317-1324.
    PMID: 27703340
    Osteoporosis is a condition causing significant morbidity and mortality in the elderly population worldwide. Age-related testosterone deficiency is the most important factor of bone loss in elderly men. Androgen can influence bone health by binding to androgen receptors directly or to estrogen receptors (ERs) indirectly via aromatization to estrogen. This review summarized the direct and indirect effects of androgens on bone derived from in vitro, in vivo, and human studies. Cellular studies showed that androgen stimulated the proliferation of preosteoblasts and differentiation of osteoblasts. The converted estrogen suppressed osteoclast formation and resorption activity by blocking the receptor activator of nuclear factor k-B ligand pathway. In animal studies, activation of androgen and ERα, but not ERβ, was shown to be important in acquisition and maintenance of bone mass. Human epidemiological studies demonstrated a significant relationship between estrogen and testosterone in bone mineral density and fracture risk, but the relative significance between the two remained debatable. Human experimental studies showed that estrogen was needed in suppressing bone resorption, but both androgen and estrogen were indispensable for bone formation. As a conclusion, maintaining optimal level of androgen is essential in preventing osteoporosis and its complications in elderly men.
    Matched MeSH terms: Bone and Bones/physiology*
  5. Boukari Y, Qutachi O, Scurr DJ, Morris AP, Doughty SW, Billa N
    J Biomater Sci Polym Ed, 2017 Nov;28(16):1966-1983.
    PMID: 28777694 DOI: 10.1080/09205063.2017.1364100
    The development of patient-friendly alternatives to bone-graft procedures is the driving force for new frontiers in bone tissue engineering. Poly (dl-lactic-co-glycolic acid) (PLGA) and chitosan are well-studied and easy-to-process polymers from which scaffolds can be fabricated. In this study, a novel dual-application scaffold system was formulated from porous PLGA and protein-loaded PLGA/chitosan microspheres. Physicochemical and in vitro protein release attributes were established. The therapeutic relevance, cytocompatibility with primary human mesenchymal stem cells (hMSCs) and osteogenic properties were tested. There was a significant reduction in burst release from the composite PLGA/chitosan microspheres compared with PLGA alone. Scaffolds sintered from porous microspheres at 37 °C were significantly stronger than the PLGA control, with compressive strengths of 0.846 ± 0.272 MPa and 0.406 ± 0.265 MPa, respectively (p 
    Matched MeSH terms: Bone and Bones/cytology*
  6. Tan, S.L., Selvaratnam, L., Ahmad, T.S.
    JUMMEC, 2015;18(2):1-14.
    MyJurnal
    Tendon is a dense connective tissue that connects muscle to bone. Tendon can adapt to mechanical forces passing across it, through a reciprocal relationship between its cellular components (tenocytes and tenoblasts) and the extracellular matrix (ECM). In early development, the formation of scleraxis-expressing tendon progenitor population in the sclerotome is induced by a fibroblast growth factor signal secreted by the myotome. Tendon injury has been defined as a loss of cells or ECM caused by trauma. It represents a failure of cells and matrix adaptation to mechanical loading. Injury initiates attempts of tendon to repair itself, which has been defined as replacement of damaged or lost cells and ECM by new cells or new matrices. Tendon healing generally consists of four different phases: the inflammatory, proliferation, differentiation and remodelling phases. Clinically, tendons are repaired with a variety of surgical techniques, which show various degrees of success. In order to improve the conventional tendon repair methods, current tendon tissue engineering aims to investigate a repair method which can restore tissue defects with living cells, or cell based therapy. Advances in tissue engineering techniques would potentially yield to a cell-based product that could regenerate functional tendon tissue.
    Matched MeSH terms: Bone and Bones
  7. Al-Abdullah KI, Lim CP, Najdovski Z, Yassin W
    Int J Med Robot, 2019 Jun;15(3):e1989.
    PMID: 30721570 DOI: 10.1002/rcs.1989
    BACKGROUND: This paper presents a model-based bone milling state identification method that provides intraoperative bone quality information during robotic bone milling. The method helps surgeons identify bone layer transitions during bone milling.

    METHODS: On the basis of a series of bone milling experiments with commercial artificial bones, an artificial neural network force model is developed to estimate the milling force of different bone densities as a function of the milling feed rate and spindle speed. The model estimations are used to identify the bone density at the cutting zone by comparing the actual milling force with the estimated one.

    RESULTS: The verification experiments indicate the ability of the proposed method to distinguish between one cortical and two cancellous bone densities.

    CONCLUSIONS: The significance of the proposed method is that it can be used to discriminate a set of different bone density layers for a range of the milling feed rate and spindle speed.

    Matched MeSH terms: Bone and Bones
  8. Mansur SA, Mieczkowska A, Flatt PR, Bouvard B, Chappard D, Irwin N, et al.
    Bone, 2016 06;87:102-13.
    PMID: 27062994 DOI: 10.1016/j.bone.2016.04.001
    Obesity and type 2 diabetes mellitus (T2DM) progress worldwide with detrimental effects on several physiological systems including bone tissue mainly by affecting bone quality. Several gut hormones analogues have been proven potent in ameliorating bone quality. In the present study, we used the leptin receptor-deficient db/db mice as a model of obesity and severe T2DM to assess the extent of bone quality alterations at the organ and tissue levels. We also examined the beneficial effects of gut hormone therapy in this model by using a new triple agonist ([d-Ala(2)]GIP-Oxm) active at the GIP, GLP-1 and glucagon receptors. As expected, db/db mice presented with dramatic alterations of bone strength at the organ level associated with deterioration of trabecular and cortical microarchitectures and an augmentation in osteoclast numbers. At the tissue level, these animals presented also with alterations of bone strength (reduced hardness, indentation modulus and dissipated energy) with modifications of tissue mineral distribution, collagen glycation and collagen maturity. The use of [d-Ala(2)]GIP-Oxm considerably improved bone strength at the organ level with modest effects on trabecular microarchitecture. At the tissue level, [d-Ala(2)]GIP-Oxm ameliorated bone strength reductions with positive effects on collagen glycation and collagen maturity. This study provides support for including gut hormone analogues as possible new therapeutic strategies for improving bone quality in bone complications associated to T2DM.
    Matched MeSH terms: Bone and Bones/drug effects; Bone and Bones/pathology*; Bone and Bones/physiopathology*
  9. Mehboob H, Tarlochan F, Mehboob A, Chang SH, Ramesh S, Harun WSW, et al.
    J Mater Sci Mater Med, 2020 Aug 20;31(9):78.
    PMID: 32816091 DOI: 10.1007/s10856-020-06420-7
    The current study is proposing a design envelope for porous Ti-6Al-4V alloy femoral stems to survive under fatigue loads. Numerical computational analysis of these stems with a body-centered-cube (BCC) structure is conducted in ABAQUS. Femoral stems without shell and with various outer dense shell thicknesses (0.5, 1.0, 1.5, and 2 mm) and inner cores (porosities of 90, 77, 63, 47, 30, and 18%) are analyzed. A design space (envelope) is derived by using stem stiffnesses close to that of the femur bone, maximum fatigue stresses of 0.3σys in the porous part, and endurance limits of the dense part of the stems. The Soderberg approach is successfully employed to compute the factor of safety Nf > 1.1. Fully porous stems without dense shells are concluded to fail under fatigue load. It is thus safe to use the porous stems with a shell thickness of 1.5 and 2 mm for all porosities (18-90%), 1 mm shell with 18 and 30% porosities, and 0.5 mm shell with 18% porosity. The reduction in stress shielding was achieved by 28%. Porous stems incorporated BCC structures with dense shells and beads were successfully printed.
    Matched MeSH terms: Bone and Bones/pathology
  10. Lai P, Nagammai T, Vethakkan S
    Malays Fam Physician, 2013;8(2):47-52.
    PMID: 25606283 MyJurnal
    Bisphosphonates are pyrophosphate analogues, with a strong affinity for bones. They inhibit bone resorption and are currently the first choice of treatment for osteoporosis. Bisphosphonates should be taken in a specific manner and for at least one year to be effective in the maintenance and improvement of bone mineral density (BMD), as well as for protection against fractures. We report a case of a postmenospausal osteoporotic woman who lost BMD despite being on bisphosphonate therapy for eight years, highlighting issues that a primary care doctor needs to address before deciding on the next best option.
    Matched MeSH terms: Bone and Bones
  11. Razak M, Ismail MM, Omar A
    Med J Malaysia, 1998 Sep;53 Suppl A:83-5.
    PMID: 10968187
    We review 81 cases of acute haematogenous osteomyelitis from 1983 to 1990 to establish current pattern of clinical presentation, modes of treatment and success of therapy. Majority of the patient (70%) presented within a week of symptom and significant number of them came with fever and swelling of the affected limb. Sedimentation rate was found to be raised in all of them. Fifty-four (55%) of them were treated surgically. The average antibiotic time was one week by intravenous administration followed by additional oral therapy for period up to four weeks. Average follow-up was 9 months. Six of them (7.5%) end up with various complication which was believed to be due to delay in getting medical treatment.
    Matched MeSH terms: Bone and Bones/metabolism*
  12. Krishnamurithy, G.
    JUMMEC, 2013;16(2):1-6.
    MyJurnal
    The biocompatibility and similarity of hydroxyapatite (HA) to the mineral composition of the bone has made HA a potential candidate in bone tissue engineering (BTE). Over the past few decades, its application as bone graft in combination with stem cells has gained much importance. The use of bone marrow-derived mesenchymal stromal cells (MSCs) will enhance the rate and quality of defect repair. However, application of hydroxyapatite as a material to develop a 3-dimension scaffold or carrier to support MSCs in vitro is still in its infant stage. This review will discuss the source, manufacturing methods and advantages of using HA scaffolds in bone tissue engineering applications.
    Matched MeSH terms: Bone and Bones
  13. Chin KY
    J Osteoporos, 2017;2017:3710959.
    PMID: 28163951 DOI: 10.1155/2017/3710959
    Aspirin is a cyclooxygenase inhibitor commonly used in primary prevention of cardiovascular diseases and cancers. Its users are elderly population susceptible to osteoporosis. It also inhibits the synthesis of prostaglandin E2 essential in bone remodeling. This prompts the question whether it can influence bone health among users. This review aimed to summarize the current literature on the use of aspirin on bone health. A literature search on experimental and clinical evidence on the effects of aspirin on bone health was performed using major scientific databases. In vitro studies showed that aspirin could enhance the survival of bone marrow mesenchymal stem cells, the progenitors of osteoblasts, and stimulate the differentiation of preosteoblasts. Aspirin also inhibited the nuclear factor kappa-B (NFκB) pathway and decreased the expression of receptor activator of NFκB ligand, thus suppressing the formation of osteoclast. Aspirin could prevent bone loss in animal models of osteoporosis. Despite a positive effect on bone mineral density, the limited human epidemiological studies revealed that aspirin could not reduce fracture risk. A study even suggested that the use of aspirin increased fracture risk. As a conclusion, aspirin may increase bone mineral density but its effect on fracture prevention is inconclusive. More data are needed to determine the effects of aspirin and bone health in human.
    Matched MeSH terms: Bone and Bones
  14. Ali M, Mohd Noor SNF, Mohamad H, Ullah F, Javed F, Abdul Hamid ZA
    Biomed Phys Eng Express, 2024 Apr 17;10(3).
    PMID: 38224615 DOI: 10.1088/2057-1976/ad1e75
    Guided tissue/bone regeneration (GTR/GBR) is a widely used technique in dentistry to facilitate the regeneration of damaged bone and tissue, which involves guiding materials that eventually degrade, allowing newly created tissue to take its place. This comprehensive review the evolution of biomaterials for guided bone regeneration that showcases a progressive shift from non-resorbable to highly biocompatible and bioactive materials, allowing for more effective and predictable bone regeneration. The evolution of biomaterials for guided bone regeneration GTR/GBR has marked a significant progression in regenerative dentistry and maxillofacial surgery. Biomaterials used in GBR have evolved over time to enhance biocompatibility, bioactivity, and efficacy in promoting bone growth and integration. This review also probes into several promising fabrication techniques like electrospinning and latest 3D printing fabrication techniques, which have shown potential in enhancing tissue and bone regeneration processes. Further, the challenges and future direction of GTR/GBR are explored and discussed.
    Matched MeSH terms: Bone and Bones
  15. Mieczkowska A, Mansur SA, Irwin N, Flatt PR, Chappard D, Mabilleau G
    Bone, 2015 Jul;76:31-9.
    PMID: 25813583 DOI: 10.1016/j.bone.2015.03.010
    Type 1 diabetes mellitus (T1DM) is a severe disorder characterized by hyperglycemia and hypoinsulinemia. A higher occurrence of bone fractures has been reported in T1DM, and although bone mineral density is reduced in this disorder, it is also thought that bone quality may be altered in this chronic pathology. Vibrational microscopies such as Fourier transform infrared microspectroscopy (FTIRM) represent an interesting approach to study bone quality as they allow investigation of the collagen and mineral compartment of the extracellular matrix in a specific bone location. However, as spectral feature arising from the mineral may overlap with those of the organic component, the demineralization of bone sections should be performed for a full investigation of the organic matrix. The aims of the present study were to (i) develop a new approach, based on the demineralization of thin bone tissue section to allow a better characterization of the bone organic component by FTIRM, (ii) to validate collagen glycation and collagen integrity in bone tissue and (iii) to better understand what alterations of tissue material properties in newly forming bone occur in T1DM. The streptozotocin-injected mouse (150 mg/kg body weight, injected at 8 weeks old) was used as T1DM model. Animals were randomly allocated to control (n = 8) or diabetic (n = 10) groups and were sacrificed 4 weeks post-STZ injection. Bones were collected at necropsy, embedded in polymethylmethacrylate and sectioned prior to examination by FTIRM. FTIRM collagen parameters were collagen maturity (area ratio between 1660 and 1690 cm(-1) subbands), collagen glycation (area ratio between the 1032 cm(-1) subband and amide I) and collagen integrity (area ratio between the 1338 cm(-1) subband and amide II). No significant differences in the mineral compartment of the bone matrix could be observed between controls and STZ-injected animals. On the other hand, as compared with controls, STZ-injected animals presented with significant higher value for collagen maturity (17%, p = 0.0048) and collagen glycation (99%, p = 0.0121), while collagen integrity was significantly lower by 170% (p = 0.0121). This study demonstrated the profound effect of early T1DM on the organic compartment of the bone matrix in newly forming bone. Further studies in humans are required to ascertain whether T1DM also lead to similar effect on the quality of the bone matrix.
    Matched MeSH terms: Bone and Bones/metabolism; Bone and Bones/pathology*
  16. Le MHT, Noor Hayaty AK, Zaini ZM, Dom SM, Ibrahim N, Radzi ZB
    Korean J Orthod, 2019 Jul;49(4):235-245.
    PMID: 31367578 DOI: 10.4041/kjod.2019.49.4.235
    Objective: This study examined bone microstructure restoration after rapid maxillary expansion (RME) with and without corticotomy over multiple retention periods.

    Methods: Eighteen male Dorper sheep were randomly distributed into three groups (n = 6 each group): group 1, RME with corticotomy on the buccal and palatal sides; group 2, conventional RME treatment; and group 3, no treatment. Post-RME, trabecular bone microstructure and new bone formation were evaluated by using microcomputed tomography (microCT) and histomorphometry after a 4- or 12-week retention period. Intergroup differences in bone quality and bone remodeling were analyzed by using two-way analysis of variance with Bonferroni post-hoc test.

    Results: The bone volume fraction (bone volume [BV]/total volume [TV]) values relative to the control in groups 1 and 2 were 54.40% to 69.88% after the 4-week retention period and returned to approximately 80% after the 12-week retention period. The pooled BV/TV values of the banded teeth in groups 1 and 2 were significantly lower than those of the control after the 4-week retention period (p < 0.05). However, after the 12-week retention period, the pooled BV/TV values in group 2 were significantly lower than those in groups 1 and 3 (p < 0.05). Histomorphological analysis showed that the new bone formation area in group 1 was approximately two to three times of those in group 2 and control.

    Conclusions: Corticotomy significantly enhanced the restoration of bone quality after the retention periods for banded teeth. This benefit might result from the increased new bone formation after corticotomy.

    Matched MeSH terms: Bone and Bones
  17. Khoo SP, Ong ST
    Ann Dent, 1998;5(1):49-52.
    MyJurnal
    Odontogenic carcinomas of the jaws are subclassified into malignant ameloblastoma, ameloblastic carcinoma and primary intraosseous carcinoma arising from within the bone. These may arise from residual islands of epithelium derived from dental lamina or epithelial lining of dental cysts. Ameloblastic carcinoma is extremely rare. An aggressive case of ameloblastic carcinoma occumng in a 59-year-old Malay man is presented. Wide excision of the primary lesion with radical neck dissection was carried out. He developed lung metastasis 4 months post-operatively. Despite chemotherapy upon discovery of lung metastasis, he expired 7 months following the initial diagnosis.
    Matched MeSH terms: Bone and Bones
  18. Mansourvar M, Shamshirband S, Raj RG, Gunalan R, Mazinani I
    PLoS One, 2015;10(9):e0138493.
    PMID: 26402795 DOI: 10.1371/journal.pone.0138493
    Assessing skeletal age is a subjective and tedious examination process. Hence, automated assessment methods have been developed to replace manual evaluation in medical applications. In this study, a new fully automated method based on content-based image retrieval and using extreme learning machines (ELM) is designed and adapted to assess skeletal maturity. The main novelty of this approach is it overcomes the segmentation problem as suffered by existing systems. The estimation results of ELM models are compared with those of genetic programming (GP) and artificial neural networks (ANNs) models. The experimental results signify improvement in assessment accuracy over GP and ANN, while generalization capability is possible with the ELM approach. Moreover, the results are indicated that the ELM model developed can be used confidently in further work on formulating novel models of skeletal age assessment strategies. According to the experimental results, the new presented method has the capacity to learn many hundreds of times faster than traditional learning methods and it has sufficient overall performance in many aspects. It has conclusively been found that applying ELM is particularly promising as an alternative method for evaluating skeletal age.
    Matched MeSH terms: Bone and Bones/physiology*; Bone and Bones/radiography
  19. Mohamed Abdelrasoul, Jahangir Bin Kamaldin, Jer Ping Ooi, Ahmed Abd El-Fattah, Gihan Kotry, Omneya Ramadan, et al.
    MyJurnal
    Introduction: Melatonin (MEL) loaded alginate-chitosan/beta-tricalcium phosphate (Alg-CH/β-TCP) composite hy- drogel has been formulated as a scaffold for bone regeneration. MEL in the scaffold was anticipated to accelerate bone regeneration. The objective of this study is to observe signs of systemic toxicity and physical changes on surface defected bone for bone regenerative performance of the composite. Methods: The proximal-medial metaphyseal cortex of the left tibia of New Zealand white rabbit was the surgical site of the defect. A total of nine rabbits were randomly allocated to three groups; Group I; implanted with MEL loaded Alg-CH/β-TCP, Group II; Alg-CH/β-TCP and Group III defects were sham control. The rabbits were daily observed to determine systemic toxicity effects by composites. The physical changes to implanted site were observed using digital x-ray radiography and computerized tomography at weeks 0, 2, 4, 6 and 8 of post-implantation. Results: There were no clinical signs of systemic toxicity for all groups of rabbits. Digital radiography did not show adverse effects to the bone. Computerized tomography showed reduction in the area size and depth volume of the implantation site, but accelerated regeneration within the 8 weeks was not significantly different (P
    Matched MeSH terms: Bone and Bones
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