1,720,993 research outputs found
Gastric and esophagus events before and during treatment of osteoporosis
No full textUdgivelsesdato: 2010-FebPrior studies have indicated an excess risk of gastroduodenal ulcers and esophagus perforations with the use of bisphosphonates. However, little is known about the contribution of comorbid conditions and concomitant drug use on this risk. We studied the risk of esophagus and gastric events in patients on a wide range of drugs against osteoporosis both before and after initiation of these drugs. We studied a nationwide register-based cohort from Denmark with all users of drugs against osteoporosis between 1996 and 2006 (n = 103,562) as cases and three age- and sex-matched controls from the general population (n = 310,683). In a crude analysis, most drugs were already associated with an increased risk of esophagitis, esophageal ulcerations, or esophageal perforations or gastroduodenal ulcers before initiation of the drugs. Upon adjustment, this excess risk disappeared for most drugs except parathyroid hormone and its analogues, etidronate and clodronate. Only for etidronate, alendronate, and raloxifene were sufficient data present for events after initiation of the drugs, and for these, an increased risk was present for all events except gastroduodenal ulcers with raloxifene. Several drugs against osteoporosis are associated with an increased risk of esophagitis, esophageal ulcers, esophageal perforation, and gastroduodenal ulcers. However, the increase was already present before initiation of the drug for several types of drugs against osteoporosis. This points at an effect of the underlying condition being treated or comorbid conditions and drugs being provided in patients with osteoporosis, such as nonsteroidal anti-inflammatory drugs and corticosteroids
Adipose derived mesenchymal stem cells – Their osteogenicity and osteoblast in vitro mineralization on titanium granule carriers
No full textPurpose: Adipose derived mesenchymal stem cells (ADMSCs) may be osteogenic, may generate neoangiogenisis and may be progenitors for differentiated osteoblast mineralization. Titanium granules may be suitable as carriers for these cells. The aim was to demonstrate the osteogenic potential of ADMSCs and the effect of porous non-oxidized (Ti) and oxidized titanium (TiO 2) granules as carriers for ADMSCs mineralization in vitro. Materials and methods: ADMSCs were isolated, cultivated in osteoblast medium and evaluated for alkaline phosphatase (ALP) assay, RNA isolation, and ALP staining. Osteoblast in vitro mineralization cells without granules or seeded on Ti or TiO 2 granules were evaluated for Alizarin Red assay and RNA isolation for later gene expressing. Results: ADMSCs express osteoblastic lineage genes, CBFA-1 and stain strongly for ALP. Mineralization was significantly higher for cells seeded on TiO 2 than on Ti granules or pure cells. Expression of ALPL and RUNX2 was significantly higher for cells seeded on TiO 2 granules and expression of COL1α1 for pure cells was significantly higher than for cells seeded on granules. Conclusion: ADMSCs have osteogenic potential. Mineralization was significantly high when cells were seeded on TiO 2 granules. TiO 2 granules may be used as carriers for adipose derived mesenchymal osteoblastic cells from laboratory bench to the patient.</p
Risk of atrial fibrillation associated with use of bisphosphonates and other drugs against osteoporosis: a cohort study
No full textUdgivelsesdato: 2010-MayWe studied the association between bisphosphonate use and risk of atrial fibrillation or flutter and the effect of confounders such as heart and lung disease in a nationwide retrospective cohort from Denmark. All users of bisphosphonates and other drugs against osteoporosis between 1996 and 2006 (n = 103,562) were the exposed group and three age- and gender-matched controls from the general population (n = 310,683) were the nonexposed group. The main outcome measure was atrial fibrillation or atrial flutter. Before initiation of treatment against osteoporosis, no excess of atrial fibrillation or flutter was present for any drug except for etidronate (OR = 1.22, 95% CI 1.15-1.29). After initiation of treatment, raloxifene was not associated with any excess risk of atrial fibrillation (OR = 0.98, 95% CI 0.72-1.33). Etidronate (HR = 1.08, 95% CI 1.02-1.14) and alendronate (HR = 1.09, 95% CI 1.00-1.20) were associated with an excess risk of atrial fibrillation after treatment start if statistical adjustments were made for cardiovascular disease. However, this association disappeared upon statistical adjustment for chronic obstructive pulmonary disease (COPD) (etidronate HR = 1.04, 95% CI 0.98-1.10; alendronate HR = 1.05, 95% CI 0.96-1.15). In patients using etidronate (12.5% vs. 3.8%) and alendronate (11.4% vs. 4.6%) major differences were present in prevalence of COPD at start of treatment compared to matched controls. In conclusion, oral bisphosphonates do not seem to be associated with an excess risk of atrial fibrillation. Any excess risk seen in prior studies may be due to confounding from COPD
Carriers in mesenchymal stem cell osteoblast mineralization-State-of-the-art
No full textPURPOSE: Tissue engineering is a new way to regenerate bone tissue, where osteogenic capable cells combine with an appropriate scaffolding material. Our aim was in a Medline Search to evaluate osteoblast mineralization in vitro and in vivo including gene expressing combining mesenchymal stem cells (MSCs) and five different carriers, titanium, collagen, calcium carbonate, calcium phosphate and polylactic acid-polyglycolic acid copolymer for purpose of a meta-or a descriptive analysis. MATERIALS AND METHODS: The search included the following MeSH words in different combinations-mesenchymal stem cells, alkaline phosphatase, bone regeneration, tissue engineering, drug carriers, tissue scaffolds, titanium, collagen, calcium carbonate, calcium phosphates and polylactic acid-polyglycolic acid copolymer. RESULTS: Two out of 80 articles included numerical values and as control, carriers and cells, on mineralization and gene expression. ß-tricalcium phosphate (ß-TCP) revealed elevated alkaline phosphatase activity, and calcium-deficient hydroxyapatite a greater gene expression of osteocalcin when seeded with induced MSCs. CONCLUSION: No data are published on titanium used as a carrier in MSC osteoblast mineralization. A meta- as well as a descriptive analysis includes numerical values of test materials and of control reactions from carrier and cells, respectively. Only two articles fulfilled these requirements
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A Novel Quality Register Study and Review of Implant Treatment of Patients with Dental Agenesis
No full textPURPOSE: (1) To present a Danish quality register (AMETO) concerning dental implant treatment for dental agenesis, assess its indicators and standards, and compare them with those acknowledged and outlined by the Institute of Medicine (IoM), World Health Organization (WHO), and Organization for Economic Cooperation and Development (OECD), classified as the quality domains efficiency, effectiveness, patient-centered care, timely care, safety, and equitability; and (2) to perform a systematic literature search and review to verify whether any quality register exists according to the six quality domains.MATERIALS AND METHODS: (1) The AMETO register is comprised of 16 process and result indicators and standards, which were compared to the six quality domains outlined by the IoM and WHO. (2) A systematic literature search was carried out using the search engines PubMed, Embase, CINAHL, Web of Science, and SveMed+. The included articles were assessed for quality indicators and standards to determine whether they conformed to the six quality domains.RESULTS: AMETO indicators and standards conformed to the quality domains outlined by the IoM. A search of "(dental agenesis) AND (dental implants)" yielded a total of 381 publications, of which 27 were included for qualitative synthesis. A search on quality indicators and dental agenesis registries yielded no results. Due to considerable heterogeneity in the reported quality indicators related to effectiveness, patient-centered care, and safety, a meta-analysis could not be conducted.CONCLUSION: AMETO conforms to the quality domains described by the IoM, WHO, and OECD. Few studies have investigated dental implant treatment of dental agenesis. Moreover, no published quality register for dental implant treatment currently exists.</p
State of the Art of Short Dental Implants:A Systematic Review of the Literature
No full textBackground: Short implants (=8 mm) are manufactured for use in atrophic regions of the jaws. As implant length in many studies has been proven to play a major role in implant survival it is indicated to evaluate survival of short implants in the present literature. Purpose: The purpose of this study was systematically to evaluate publications concerning short dental implants defined as an implant with a length of =8 mm installed in the maxilla or in the mandible with special reference to implant type, survival rate, location of implant site, and observation time. Materials and Methods: A Medline and a hand search were conducted to identify studies concerning short dental implants of length =8 mm published between 1992 and October 2009. The articles included in this study report data on implant length =8 mm, implant surface, registered region of installment, observation time, single tooth restorations, supporting overdentures, splinted implants, and implants used for prostheses. Results: The 27 included studies represent zero randomized clinical trial studies, 15 prospective nonrandomized, noncontrolled clinical trials, 11 retrospective nonrandomized, noncontrolled clinical trials, and one review. Data on 6-mm implants were few and most frequent represented was manufactured Straumann implants representing 441 out of 549 implants. Brånemark implants, 7 mm in length, comprised 1607 implants out of 1808. Straumann implants, 8 mm in length, comprised 2040 out of 2352 implants. Failures varied between 0 and 14.5%, 0 and 37.5% and 0 and 22.9% of the 6-, 7-, and 8-mm-long implants, respectively. Conclusion: Short implant length was not related to observation time, installment region, failures, and dropouts were not specified, subsequently a meta-analysis was not possible to perform
Synchrotron μCT Imaging of Bone, Titanium implants and Bone Substitutes -a Systematic Review of the Literature
No full textToday x-ray micro computer tomography (μCT) imaging is used to investigate bone microarchitecture. μCT imaging is obtained by polychromatic x-ray beams, resulting in images with beam hardening artifacts, resolution levels at 10 μm, geometrical blurring, and lack of contrasts. When μCT is coupled to synchrotron sources (SRμCT) a spatial resolution up to one tenth of a μm may be achieved. A review of the literature concerning SRμCT was performed to investigate its usability and its strength in visualizing fine bone structures, vessels, and microarchitecture of bone. Although mainly limited to in vitro examinations, SRμCT is considered as a gold standard to image trabecular bone microarchitecture since it is possible in a 3D manner to visualize fine structural elements within mineralized tissue such as osteon boundaries, rods and plates structures, cement lines, and differences in mineralizatio
- …
