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Correlation of Platelet Growth Factor Release in Jawbone Defect Repair – A Study in the Dog Mandible
Andreas LI Thor DDS PhD Jaan Hong PhD Göran Kjeller DDS PhD Lars Sennerby DDS PhD Lars Rasmusson DDS PhD 《Clinical implant dentistry and related research》2013,15(5):759-768
Background: Platelet concentrate/platelet‐rich plasma (PRP) has been studied extensively in various experimental models and there is some agreement among workers to its early effect in bone regeneration and healing. We have earlier showed in vitro that titanium in whole blood activates the thrombogenic response to a higher degree than PRP and that a fluoridated test surface augmented the effect compared with control. Purpose: We designed this study to evaluate the effect of PRP and whole blood on bone regeneration in a dog implant defect model and, in addition, the effect of a test surface modified in hydrofluoric acid. A correlation attempt between platelet count, release of growth factors, and bone regeneration was made. Materials and Methods: Six dogs were used and simultaneously with the experimental surgery and implant installation, autologous PRP was prepared. Defects were prepared (6 mm in diameter and 5 mm deep), and implants were installed (TiO2 gritblasted and hydrofluoric acid treated [test] or TiO2 gritblasted [control], 5 mm in diameter and 9 mm long) in defects filled with either PRP or whole blood. Randomization of sides between PRP and whole blood, and sites for test and control implants were made. Blood samples were collected from PRP and whole blood. The dogs were killed after 5 weeks of healing, and samples with implants and surrounding bone were collected and processed for analysis. Enzyme linked immunosorbent assays were used for detection of growth factors in PRP. Results: The mean increase of platelet count was 424% in PRP. A correlation for platelet counts and transforming growth factor β was found in each dog (r2 = 0.857). Approximately 50% of the region of interest (ROI) in the defects was filled with new bone after 5 weeks. No difference could be observed in ROI by using PRP or whole blood in the defects regarding new bone formation, bone in contact with implant, or distance to first bone contact. However, the fluoridated implants exhibited more new bone formation (p = .03) compared with control, regardless of comparing PRP or whole blood, and also displayed a shorter distance from first bone contact to the margin of the bone envelope (p = .05). Conclusions: Platelet concentrate/PRP failed to show more new bone regeneration in a peri‐implant defect model compared with whole blood. Implants treated with hydrofluoric acid displayed higher percentages of bone fill in the defect. 相似文献
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Congenital adrenal hyperplasia (CAH) is a group of disorders affecting adrenal steroid synthesis. The most common form, 21-hydroxylase deficiency, leads to decreased production of cortisol and aldosterone with increased androgen secretion. In classic CAH glucocorticoid treatment can be life-saving, and provides symptom control, but must be given in an unphysiological manner with the risk of negative long-term outcomes. A late diagnosis or a severe phenotype or genotype has also a negative impact. These factors can result in impaired quality of life (QoL), increased cardiometabolic risk, short stature, osteoporosis and fractures, benign tumors, decreased fertility, and vocal problems. The prognosis has improved during the last decades, thanks to better clinical management and nowadays the most affected patients seem to have a good QoL. Very few patients above the age of 60 years have, however, been studied. Classifying patients according to genotype may give additional useful clinical information. The introduction of neonatal CAH screening may enhance long-term results. Monitoring of different risk factors and negative consequences should be done regularly in an attempt to improve clinical outcomes further. 相似文献
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Aims To estimate the effect on violence of small changes in closing hours for on‐premise alcohol sales, and to assess whether a possible effect is symmetrical. Design, setting, and participants A quasi‐experimental design drawing on data from 18 Norwegian cities that have changed (extended or restricted) the closing hours for on‐premise alcohol sales. All changes were ≤ 2 hours. Measurements Closing hours were measured in terms of the latest permitted hour of on‐premise trading, ranging from 1 a.m. to 3 a.m. The outcome measure comprised police‐reported assaults that occurred in the city centre between 10 p.m. and 5 a.m. at weekends. Assaults outside the city centre during the same time window should not be affected by changes in closing hours but function as a proxy for potential confounders, and was thus included as a control variable. The data spanned the period Q1 2000–Q3 2010, yielding 774 observations. Findings Outcomes from main analyses suggested that each 1‐hour extension of closing hours was associated with a statistically significant increase of 4.8 assaults (95% CI 2.60, 6.99) per 100 000 inhabitants per quarter (i.e. an increase of about 16%). Findings indicate that the effect is symmetrical. These findings were consistent across three different modelling techniques. Conclusion In Norway, each additional 1‐hour extension to the opening times of premises selling alcohol is associated with a 16% increase in violent crime. 相似文献
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Kristian Bartnes Trude Sildnes Amjid Iqbal Øystein Dahl-Eriksen Thor Trovik Terje Kristian Steigen 《Scandinavian cardiovascular journal : SCJ》2013,47(2):83-86
Objectives. Angiography by selective catheterization is the reference standard for coronary bypass graft patency assessment but carries a risk of serious complications. We have investigated whether 16-slice multidetector spiral computed tomography (MDCT) can substitute for selective angiography. Design. Two to three years after coronary artery bypass grafting, 45 patients with a total of 156 bypasses (100 single and 28 sequential grafts) were examined with both MDCT and conventional selective angiography on the same day. The bypasses were classified as patent, stenotic or occluded. Results. The likelihood ratio for MDCT-detected occlusion was 40, reflecting a fairly high combined sensitivity and specificity. However, 24% of the distal anastomoses could not be evaluated by MDCT, mainly because of respiratory movements, artifacts due to metal clips, and small vessel dimensions. Moreover, seven out of 117 bypasses (6%) deemed evaluable by MDCT were wrongly classified by this method. Conclusions. At present, 16-slice MDCT cannot replace selective angiography for assessment of coronary bypass graft patency since 24% of bypasses could not be evaluated by this method, and an error rate of 6% is unacceptable. 相似文献
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Joar Hary Espen Guldahl Wiger Roald Bahr Thor Einar Andersen 《Scandinavian journal of medicine & science in sports》2019,29(8):1092-1100
Groin injuries represent a considerable problem in male football, accounting for 4%‐19% of all time‐loss injuries. The Adductor Strengthening Programme is the first groin‐specific prevention program shown to reduce the risk of groin problems. We aimed to use the RE‐AIM framework to examine the players’ experiences with the implementation of the program and player attitude toward groin injury prevention in football. Of the 632 players involved in the trial examining the effect of the Adductor Strengthening Programme, 501 agreed to participate in a survey at the end of the season. Most players thought that footballers are at moderate to high risk for groin injuries (87%) and that there is a need for preventive measures (96%). They also believed that a preventive program with strengthening exercises would reduce the risk of groin injuries (91%). Majority of the players reported using <5 minutes to complete the program (73%), and only 11% wanted additional exercises. However, only 46% reported to have performed the program as recommended, and an even smaller proportion (31%) planned to continue using it as recommended the next season. Our results suggest that footballers believe that prevention of groin injuries is needed. Attitude toward implementation of the Adductor Strengthening Programme was positive, and the single‐exercise approach was considered an important facilitator. However, in future dissemination of the program, the players’ reluctance to maintain the exercise protocol may be a potential barrier to implementation that should be addressed. 相似文献
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Fatima Jabbari Erika Reiser Andreas Thor Malin Hakelius Daniel Nowinski 《Upsala journal of medical sciences》2016,121(1):33-37
Objective To determine in individuals with unilateral cleft lip and palate the correlation between initial cleft size and dental anomalies, and the outcome of alveolar bone grafting.Methods A total of 67 consecutive patients with non-syndromic unilateral complete cleft lip and palate (UCLP) were included from the cleft lip and palate-craniofacial center, Uppsala University Hospital, Sweden. All patients were operated by the same surgeon and treated according to the Uppsala protocol entailing: lip plasty at 3 months, soft palate closure at 6 months, closure of the residual cleft in the hard palate at 2 years of age, and secondary alveolar bone grafting (SABG) prior to the eruption of the permanent canine. Cleft size was measured on dental casts obtained at the time of primary lip plasty. Dental anomalies were registered on radiographs and dental casts obtained before bone grafting. Alveolar bone height was evaluated with the Modified Bergland Index (mBI) at 1 and 10-year follow-up.Results Anterior cleft width correlated positively with enamel hypoplasia and rotation of the central incisor adjacent to the cleft. There was, however, no correlation between initial cleft width and alveolar bone height at either 1 or 10 years follow-up.Conclusions Wider clefts did not seem to have an impact on the success of secondary alveolar bone grafting but appeared to be associated with a higher degree of some dental anomalies. This finding may have implications for patient counseling and treatment planning. 相似文献