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941.
E. A. Marques V. Gudnason G. Sigurdsson T. Lang F. Johannesdottir K. Siggeirsdottir L. Launer G. Eiriksdottir T. B. Harris 《Osteoporosis international》2016,27(5):1765-1776
Summary
Association between serum bone formation and resorption markers and bone mineral, structural, and strength variables derived from quantitative computed tomography (QCT) in a population-based cohort of 1745 older adults was assessed. The association was weak for lumbar spine and femoral neck areal and volumetric bone mineral density.Introduction
The aim of this study was to examine the relationship between levels of bone turnover markers (BTMs; osteocalcin (OC), C-terminal cross-linking telopeptide of type I collagen (CTX), and procollagen type 1N propeptide (P1NP)) and quantitative computed tomography (QCT)-derived bone density, geometry, and strength indices in the lumbar spine and femoral neck (FN).Methods
A total of 1745 older individuals (773 men and 972 women, aged 66–92 years) from the Age, Gene/Environment Susceptibility (AGES)–Reykjavik cohort were studied. QCT was performed in the lumbar spine and hip to estimate volumetric trabecular, cortical, and integral bone mineral density (BMD), areal BMD, bone geometry, and bone strength indices. Association between BTMs and QCT variables were explored using multivariable linear regression.Results
Major findings showed that all BMD measures, FN cortical index, and compressive strength had a low negative correlation with the BTM levels in both men and women. Correlations between BTMs and bone size parameters were minimal or not significant. No associations were found between BTMs and vertebral cross-sectional area in women. BTMs alone accounted for only a relatively small percentage of the bone parameter variance (1–10 %).Conclusion
Serum CTX, OC, and P1NP were weakly correlated with lumbar spine and FN areal and volumetric BMD and strength measures. Most of the bone size indices were not associated with BTMs; thus, the selected bone remodeling markers do not reflect periosteal bone formation. These results confirmed the limited ability of the most sensitive established BTMs to predict bone structural integrity in older adults.942.
943.
Two Rare Mutations in the COL1A2 Gene Associate With Low Bone Mineral Density and Fractures in Iceland
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Unnur Styrkarsdottir Gudmar Thorleifsson Berglind Eiriksdottir Sigurjon A Gudjonsson Thorvaldur Ingvarsson Jacqueline R Center Tuan V Nguyen John A Eisman Claus Christiansen Unnur Thorsteinsdottir Gunnar Sigurdsson Kari Stefansson 《Journal of bone and mineral research》2016,31(1):173-179
We conducted a genome‐wide association study of low bone mineral density (BMD) at the hip and spine utilizing sequence variants found through whole‐genome sequencing of 2636 Icelanders. We found two rare missense mutations, p.Gly496Ala and p.Gly703Ser, in the COL1A2 gene that associate with measures of osteoporosis in Icelanders. Mutations in COL1A2 are known to cause the autosomal dominant disorder osteogenesis imperfecta. Both variants associate with low BMD and with osteoporotic fractures. p.Gly496Ala (frequency of 0.105%) shows the strongest association with low BMD at the spine (p = 1.8 × 10?7, odds ratio [OR] = 4.61 [95% confidence interval (CI) 2.59, 8.18]), whereas p.Gly703Ser (frequency of 0.050%) is most strongly associated with low BMD at the hip (p = 1.9 × 10?8, OR = 9.34 [95% CI 4.28, 20.3]). Association with fractures was p = 2.2 × 10?5, OR = 3.75 (95% CI 2.03, 6.93) and p = 0.0023, OR = 4.32 (95% CI 1.69, 11.1), respectively. The carriers of these variants do not have signs of osteogenesis imperfecta other than low BMD, demonstrating that similar mutations in COL1A2 can affect skeletal phenotypes in more than one way. © 2015 American Society for Bone and Mineral Research. 相似文献
944.
Periodontal repair in dogs: effect of transforming growth factor-beta 1 on alveolar bone and cementum regeneration 总被引:2,自引:0,他引:2
Tatakis DN Wikesjö UM Razi SS Sigurdsson TJ Lee MB Nguyen T Ongpipattanakul B Hardwick R 《Journal of clinical periodontology》2000,27(9):698-704
BACKGROUND: Transforming growth factor-beta (TGF-beta) represents a family of growth-modulating proteins with fundamental roles in connective tissue and bone development. The objective of this study was to evaluate the potential for regeneration of alveolar bone and cementum following surgical implantation of recombinant human TGF-beta 1 (rhTGF-beta 1). METHOD: Bilateral, critical size, supra-alveolar periodontal defects in 5 beagle dogs were surgically implanted with rhTGF-beta 1 in a calcium carbonate carrier (CaCO3) or with carrier alone. The animals were euthanized at 4 weeks postsurgery and block-biopsies of the defects were processed for histologic and histometric analysis. RESULTS: Surgical implantation of rhTGF-beta 1 resulted in minimal, if any, stimulation of alveolar bone or cementum regeneration. Linear bone and cementum regeneration in rhTGF-beta 1-treated defects was 1.2+/-0.6 and 0.01+0.01 mm, respectively. Corresponding values for the controls were 1.0+/-0.6 and 0.01+/-0.03 mm. CONCLUSIONS: The results suggest that, under the conditions (dose, carrier, defect type) evaluated here, treatment of periodontal defects in beagle dogs with rhTGF-beta 1 may be of limited clinical benefit. 相似文献
945.
Guidelines for the management of traumatic dental injuries. I. Fractures and luxations of permanent teeth 总被引:2,自引:0,他引:2
Marie Therese Flores Lars Andersson Jens Ove Andreasen Leif K. Bakland Barbro Malmgren Frederick Barnett Cecilia Bourguignon Anthony DiAngelis Lamar Hicks Asgeir Sigurdsson Martin Trope Mitsuhiro Tsukiboshi Thomas von Arx 《Dental traumatology》2007,23(2):66-71
Abstract – Crown fractures and luxations occur most frequently of all dental injuries. An appropriate treatment plan after an injury is important for a good prognosis. Guidelines are useful for delivering the best care possible in an efficient manner. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the group. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion of the IADT board members. The guidelines represent the current best evidence, based on literature research and professional opinion. In this first article of three, the IADT Guidelines for management of fractures and luxations of permanent teeth will be presented. 相似文献
946.
Guidelines for the management of traumatic dental injuries. II. Avulsion of permanent teeth 总被引:3,自引:0,他引:3
Marie Therese Flores Lars Andersson Jens Ove Andreasen Leif K. Bakland Barbro Malmgren Frederick Barnett Cecilia Bourguignon Anthony DiAngelis Lamar Hicks Asgeir Sigurdsson Martin Trope Mitsuhiro Tsukiboshi Thomas von Arx 《Dental traumatology》2007,23(3):130-136
Abstract – Avulsion of permanent teeth is the most serious of all dental injuries. The prognosis depends on the measures taken at the place of accident or the time immediately after the avulsion. Replantation is the treatment of choice, but cannot always be carried out immediately. An appropriate emergency management and treatment plan is important for a good prognosis. Guidelines are useful for delivering the best care possible in an efficient manner. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the group. In cases in which the data did not appear conclusive, recommendations were based on the consensus opinion of the IADT board members. The guidelines represent the current best evidence based on literature research and professional opinion. In this second article of three, the IADT Guidelines for management of avulsed permanent teeth are presented. 相似文献
947.
Sigurdsson S Bödvarsdottir SK Anamthawat-Jonsson K Steinarsdottir M Jonasson JG Ogmundsdottir HM Eyfjörd JE 《Cancer Genetics and Cytogenetics》2000,121(2):150-155
To clarify the important role of the tumor-suppressor gene p53 in maintaining genetic integrity, we estimated chromosome instability and staining of overexpressed p53 protein in the same cells of five primary breast carcinomas. The method included both fluorescence immunohistochemistry and fluorescence in situ hybridization (FISH) on sections from formalin-fixed, paraffin-embedded breast cancer tissue. By using a centromeric FISH probe for chromosome 17 on interphase cells in these sections, we showed that cells with abnormal p53 protein expression had a statistically significant higher number of chromosome 17 than did cells with no p53 protein staining in the same samples as well as cells in four other tumor samples with no p53 protein staining. The samples identified positive for p53 abnormality by immunostaining were shown to have p53 mutation by constant denaturing gel electrophoresis analysis and DNA sequencing. These mutated samples were characterized by high DNA index, high S-phase, abnormal karyotype, and aneuploidy. The results strongly implicate p53 mutation as a cause for chromosomal instability and a crucial step in mammary carcinogenesis. 相似文献
948.
Anderson RA; Wallace EM; Groome NP; Bellis AJ; Wu FC 《Human reproduction (Oxford, England)》1997,12(4):746-751
Inhibin has been postulated to be secreted by Sertoli cells in response to
follicle stimulating hormone (FSH) and in turn to exert an inhibitory
effect on FSH production. We have investigated this relationship using an
assay specific for dimeric inhibin B. A total of 56 normal men received 200
mg testosterone enanthate (TE) i.m. weekly, for 65 +/- 1 weeks in a trial
of hormonal male contraception. Before treatment a significant negative
correlation between inhibin B and FSH concentration (r = 0.49, P <
0.001) was observed. During TE treatment, luteinizing hormone (LH) and FSH
were rapidly suppressed. This was followed by a parallel decline in inhibin
B and sperm concentration. During the early recovery phase, inhibin B
concentrations remained suppressed in men who showed a delay in resumption
of spermatogenesis, despite higher FSH concentrations. Inhibin B returned
to pretreatment concentrations after 24 weeks recovery, when the inverse
relationship with FSH was restored. Our results showed the expected inverse
physiological relationship between inhibin B and FSH in normal men, with a
decline during TE treatment and alpha subsequent resumption of the inverse
relationship during recovery. These data clearly support the hypothesis
that inhibin B plays a physiological role in the feedback control of FSH
secretion, and reflects FSH-stimulated Sertoli cell function.
相似文献
949.
Summary The virus of Visna, a slow, demyelinating leucoencephalitis of sheep, has been cultivated in tissue culture. The cells employed are derived from the chorioid plexus of sheep. The virus causes characteristic cytopathic changes in the culture, so that the method may be used to detect virus activity and measure the activity of virus containing material.Virus which had undergone 3, 11, and 12 passages in TC was injected intracerebrally into sheep and found to produce typical Visna lesions.Neutralizing antibody has been detected in sera from a certain proportion of sheep affected with Visna.The rate of virus multiplication in tissue culture after inocula of varying size has been studied. Small inocula tend to give rise to a mild infection which persists in the culture for long periods of time without destroying more than a certain proportion of the cells.The possible relationship between this relatively stable balance between virus and cells and the extraordinarily slow progress of Visna in the CNS of sheep is discussed. 相似文献
950.
Quality of life and functional outcome following anterior or abdominoperineal resection for rectal cancer. 总被引:9,自引:0,他引:9
M G Guren M T Eriksen J N Wiig E Carlsen A Nesbakken H K Sigurdsson A Wibe K M Tveit 《European journal of surgical oncology》2005,31(7):735-742
AIMS: The aims of the study were (1) to evaluate quality of life (QoL) and functional outcome in patients following anterior resection (AR) or abdominoperineal resection (APR) for rectal cancer, and (2) whether these outcomes were dependent on the level of anastomosis. METHODS: Patients who were without recurrent or metastatic disease were identified from the Norwegian Rectal Cancer Registry. QoL was assessed by the EORTC questionnaires QLQ-C30 and QLQ-CR38, and rectal function by a short questionnaire. Of 319 patients studied, 229 had undergone AR and 90 APR. The median age was 73 years, and the median time since surgery was 64 months. RESULTS: Mean QoL scores for body image and male sexual problems were better following AR than APR (P<0.01), also in patients with a low (< or = 3 cm) anastomosis. Patients who had undergone AR had higher mean scores for constipation (P<0.001) and more often used anti-diarrhoeal medication (P=0.005), than patients who had undergone APR. Patients with a low anastomosis (< or = 3 cm) had more incontinence for gas and solid stools (P<0.05), and had more incontinence (P=0.006) compared with patients with higher anastomosis, but there was no difference in QoL. Subgroup analysis showed that irradiated patients (n=34) had worse rectal function in terms of frequency, urgency, and incontinence (P<0.01). CONCLUSIONS: Although rectal function was impaired in patients with low anastomosis, patients who had undergone AR had better QoL than patients who had undergone APR. 相似文献