Dose-dependent new bone formation by extracorporeal shock wave application on the intact femur of rabbits

Background: Whereas various molecular working mechanisms of shock waves have been demonstrated, no study has assessed in detail the influence of varying energy flux densities (EFD) on new bone formation in vivo. Methods: Thirty Chinchilla bastard rabbits were randomly assigned to 5 groups (EFD 0.0, 0.35, 0.5, 0.9 and 1.2 mJ/mm(2)) and treated with extracorporeal shock waves at the distal femoral region (1,500 pulses; 1 Hz frequency). To investigate new bone formation, animals were injected with oxytetracycline at days 5-9 after shock wave application and sacrificed on day 10. Histological sections of all animals were examined using broad-band epifluorescent illumination, contact microradiography and Giemsa-Eosin staining. Results: Application of shock waves induced new bone formation beginning with 0.5 mJ/mm(2) EFD and increasing with 0.9 mJ/mm(2) and 1.2 mJ/mm(2). The latter EFD resulted in new bone formation also on the dorsal cortical bone; cortical fractures and periosteal detachment also occurred. Conclusion: Here, for the first time, a threshold level is presented for new bone formation after applying shock waves to intact bone in vivo. The findings of this study are of considerable significance for preventing unwanted side effects in new approaches in the clinical application of shock waves. Copyright (c) 2008 S. Karger AG, Basel

З історії озброєння козацького війська першої половини 18 ст.

В низці реформ, які спіткали у 18 ст. військо гетьманського регіменту, та їхня невелика частина, котра стосувалася озброєння є чи не найменше відомою не тільки широкому загалу істориків, але й вузьким спеціалістам з періоду. Перші спроби прищеплення козакам “регулярства” ще з часів Петра І були спрямовані головним чином, на впровадження адміністративних і організаційних новацій, впорядкування фінансування й забезпечення при одночасному нехтуванні власне озброєнням і бойовою підготовкою війська. Втім, саме вони після Північної війни і “Низових” походів, які виявили всі недоліки, притаманні становій організації збройних сил, дуже гостро поставили питання боєздатності козацьких полків. Наріжною проблемою була якість озброєння реєстрових козаків. Як відомо, для цієї частини гетьманського війська традиційно не існувало жодних регламентацій, що б визначали види й перелік озброєння, термін його служби, навчання застосування тощо. Виняток становили лише наймані формування, забезпечення яких вогнепальною й деякими іншими видами зброї, а також боєприпасами, перебрала на себе держава [1]. На початку 18 ст. комплекс озброєння лівобережного козацтва загалом мало чим відрізнявся від попереднього століття, складаючись з традиційних піки, шаблі, різноманітних видів рушниць й іноді – пістолів і луків зі стрілами [2]. Кожен козак мусив власним коштом купувати необхідну йому амуніцію та зброю, вряди-годи дістаючи зі скарбу лише боєприпаси до неї. В умовах постійно прогресуючої майнової диференціації козацтва це призводило з одного боку до того, що частина збіднілого товариства взагалі не могла відбувати воєнну службу, а та, що була спроможною оплачувати спорядження, озброювалася відповідно не до воєнних потреб, а своїх матеріальних можливостей і бажання. Так, при підготовці кампанії 1707 р., Петро І наказував Мазепі виправити до діючої армії виборних козаків і компанійців, “которые б имели добрые кони и ружье”, дорікаючи за минулорічні бої в яких у козаків “почитай что ни у кого сабли не видали, кроме пищалей и сайдаков” [3]. Стан озброєності істотно погіршився ще й внаслідок поразок гетьманського війська у битвах зі шведами, виснажливих чергувань на форпостах і походів на Каспій. Годі й говорити, що за таких умов будь-яка уніфікація козацького озброєння була справою бажаною, але надзвичайно складною. Скарб Гетьманщини після численних реформ Малоросійської колегії й хронічної децентралізованості фінансового господарства навряд чи зміг би подужати проведення подібних заходів. Окрім того, в Україні практично не існувало ані необхідної сировинної бази, ані мережі зброярських підприємств мануфактурного типу, котрі б працювали на державне замовлення й могли б виконувати великі замовлення. Розвиток численних рудень Лівобережжя, котрі були зобовязані віддавати частину продукованого ними заліза на потребу війська, як відомо, не призвів до їх перетворення на металургійні заводи

Osteonecrosis of the jaw as a possible rare side effect of annual bisphosphonate administration for osteoporosis: A case report

<p>Abstract</p> <p>Introduction</p> <p>Osteonecrosis of the jaw is a serious side effect in patients receiving nitrogen-containing bisphosphonates intravenously due to malignant diseases. Albeit far less frequently, osteonecrosis of the jaw has also been reported to occur due to the oral administration of nitrogen-containing bisphosphonates due to osteoporosis. Annual infusions of zoledronic acid have been recommended in order to improve patient compliance, to optimize therapeutic effects and to minimize side effects. To date, osteonecrosis of the jaw has not been linked to the annual administration of bisphosphonates.</p> <p>Case presentation</p> <p>We report the case of a 65-year-old Caucasian woman suffering from osteoporosis who developed early stage osteonecrosis of the jaw in two locations, with chronic infections, after two months of oral bisphosphonate treatment and three annual administrations of zoledronic acid. Our patient was treated by fluorescence-guided resection of the necrotic jaw bone areas; local inflammation was treated by removal of a wisdom tooth and repeat root resections. Histopathology revealed typical hallmarks of osteonecrosis of the jaw.</p> <p>Conclusion</p> <p>Osteonecrosis of the jaw may occur as a consequence of annual administrations of zoledronic acid. It is conceivable that, due to the pharmacological properties of bisphosphonates, a jaw bone that encounters frequent local inflammations is more likely to develop osteonecrosis.</p

The Bone-Forming Effects of HIF-1α-Transduced BMSCs Promote Osseointegration with Dental Implant in Canine Mandible

The presence of insufficient bone volume remains a major clinical problem for dental implant placement to restore the oral function. Gene-transduced stem cells provide a promising approach for inducing bone regeneration and enhancing osseointegration in dental implants with tissue engineering technology. Our previous studies have demonstrated that the hypoxia-inducible factor-1α (HIF-1α) promotes osteogenesis in rat bone mesenchymal stem cells (BMSCs). In this study, the function of HIF-1α was validated for the first time in a preclinical large animal canine model in term of its ability to promote new bone formation in defects around implants as well as the osseointegration between tissue-engineered bone and dental implants. A lentiviral vector was constructed with the constitutively active form of HIF-1α (cHIF). The ectopic bone formation was evaluated in nude mice. The therapeutic potential of HIF-1α-overexpressing canine BMSCs in bone repair was evaluated in mesi-implant defects of immediate post-extraction implants in the canine mandible. HIF-1α mediated canine BMSCs significantly promoted new bone formation both subcutaneously and in mesi-implant defects, including increased bone volume, bone mineral density, trabecular thickness, and trabecular bone volume fraction. Furthermore, osseointegration was significantly enhanced by HIF-1α-overexpressing canine BMSCs. This study provides an important experimental evidence in a preclinical large animal model concerning to the potential applications of HIF-1α in promoting new bone formation as well as the osseointegration of immediate implantation for oral function restoration

Morphologic characterization of osteosarcoma growth on the chick chorioallantoic membrane

<p>Abstract</p> <p>Background</p> <p>The chick chorio-allantoic membrane (CAM) assay is a commonly used method for studying angiogenic or anti-angiogenic activities <it>in vivo</it>. The ease of access allows direct monitoring of tumour growth by biomicroscopy and the possibility to screen many samples in an inexpensive way. The CAM model provides a powerful tool to study effects of molecules, which interfere with physiological angiogenesis, or experimental tumours derived from cancer cell lines. We therefore screened eight osteosarcoma cell lines for their ability to form vascularized tumours on the CAM.</p> <p>Findings</p> <p>We implanted 3-5 million cells of human osteosarcoma lines (HOS, MG63, MNNG-HOS, OST, SAOS, SJSA1, U2OS, ZK58) on the CAM at day 10 of embryonic development. Tumour growth was monitored by <it>in vivo </it>biomicroscopy at different time points and tumours were fixed in paraformaldehyde seven days after cell grafting. The tissue was observed, photographed and selected cases were further analyzed using standard histology.</p> <p>From the eight cell lines the MNNG-HOS, U2OS and SAOS were able to form solid tumours when grafted on the CAM. The MNNG-HOS tumours showed the most reliable and consistent growth and were able to penetrate the chorionic epithelium, grow in the CAM stroma and induce a strong angiogenic response.</p> <p>Conclusions</p> <p>Our results show that the CAM assay is a useful tool for studying osteosarcoma growth. The model provides an excellent alternative to current rodent models and could serve as a preclinical screening assay for anticancer molecules. It might increase the speed and efficacy of the development of new drugs for the treatment of osteosarcoma.</p

Detection and Characterization of CD133+ Cancer Stem Cells in Human Solid Tumours

Osteosarcoma is the most common primary tumour of bone. Solid tumours are made of heterogeneous cell populations, which display different goals and roles in tumour economy. A rather small cell subset can hold or acquire stem potentials, gaining aggressiveness and increasing expectancy of recurrence. The CD133 antigen is a pentaspan membrane glycoprotein, which has been proposed as a cancer stem cell marker, since it has been previously demonstrated to be capable of identifying a cancer initiating subpopulation in brain, colon, melanoma and other solid tumours. Therefore, our aim was to observe the possible presence of cells expressing the CD133 antigen within solid tumour cell lines of osteosarcoma and, then, understand their biological characteristics and performances.In this study, using SAOS2, MG63 and U2OS, three human sarcoma cell lines isolated from young Caucasian subjects, we were able to identify and characterize, among them, CD133+ cells showing the following features: high proliferation rate, cell cycle detection in a G2\M phase, positivity for Ki-67, and expression of ABCG2 transporters. In addition, at the FACS, we were able to observe the CD133+ cell fraction showing side population profile and forming sphere-clusters in serum-free medium with a high clonogenic efficiency.Taken together, our findings lead to the thought that we can assume that we have identified, for the first time, CD133+ cells within osteosarcoma cell lines, showing many features of cancer stem cells. This can be of rather interest in order to design new therapies against the bone cancer

Influence of ARHGEF3 and RHOA Knockdown on ACTA2 and Other Genes in Osteoblasts and Osteoclasts

Osteoporosis is a common bone disease that has a strong genetic component. Genome-wide linkage studies have identified the chromosomal region 3p14-p22 as a quantitative trait locus for bone mineral density (BMD). We have previously identified associations between variation in two related genes located in 3p14-p22, ARHGEF3 and RHOA, and BMD in women. In this study we performed knockdown of these genes using small interfering RNA (siRNA) in human osteoblast-like and osteoclast-like cells in culture, with subsequent microarray analysis to identify genes differentially regulated from a list of 264 candidate genes. Validation of selected findings was then carried out in additional human cell lines/cultures using quantitative real-time PCR (qRT-PCR). The qRT-PCR results showed significant down-regulation of the ACTA2 gene, encoding the cytoskeletal protein alpha 2 actin, in response to RHOA knockdown in both osteoblast-like (P<0.001) and osteoclast-like cells (P = 0.002). RHOA knockdown also caused up-regulation of the PTH1R gene, encoding the parathyroid hormone 1 receptor, in Saos-2 osteoblast-like cells (P<0.001). Other findings included down-regulation of the TNFRSF11B gene, encoding osteoprotegerin, in response to ARHGEF3 knockdown in the Saos-2 and hFOB 1.19 osteoblast-like cells (P = 0.003– 0.02), and down-regulation of ARHGDIA, encoding the Rho GDP dissociation inhibitor alpha, in response to RHOA knockdown in osteoclast-like cells (P<0.001). These studies identify ARHGEF3 and RHOA as potential regulators of a number of genes in bone cells, including TNFRSF11B, ARHGDIA, PTH1R and ACTA2, with influences on the latter evident in both osteoblast-like and osteoclast-like cells. This adds further evidence to previous studies suggesting a role for the ARHGEF3 and RHOA genes in bone metabolism

Differences in the pattern and regulation of mineral deposition in human cell lines of osteogenic and non-osteogenic origin

Bone marrow-derived mesenchymal stem cells (MSCs) are widely used as a cellular model of bone formation, and can mineralize in vitro in response to osteogenic medium (OM). It is unclear, however, whether this property is specific to cells of mesenchymal origin. We analysed the OM response in 3 non-osteogenic lines, HEK293, HeLa and NTera, compared to MSCs. Whereas HEK293 cells failed to respond to OM conditions, the 2 carcinoma-derived lines NTera and HeLa deposited a calcium phosphate mineral comparable to that present in MSC cultures. However, unlike MSCs, HeLa and NTera cultures did so in the absence of dexamethasone. This discrepancy was confirmed, as bone morphogenetic protein inhibition obliterated the OM response in MSCs but not in HeLa or NTera, indicating that these 2 models can deposit mineral through a mechanism independent of established dexamethasone or bone morphogenetic protein signalling