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Simulation Study of Radio Frequency Safety and the Optimal Size of a Single-Channel Surface Radio Frequency Coil for Mice at 9.4 T Magnetic Resonance Imaging. SENSORS 2022; 22:s22114274. [PMID: 35684895 PMCID: PMC9185248 DOI: 10.3390/s22114274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 05/22/2022] [Accepted: 06/01/2022] [Indexed: 12/04/2022]
Abstract
The optimized size of a single-channel surface radio frequency (RF) coil for mouse body images in a 9.4 T magnetic resonance imaging (MRI) system was determined via electromagnetic-field analysis of the signal depth according to the size of a single-channel coil. The single-channel surface RF coils used in electromagnetic field simulations were configured to operate in transmission/reception mode at a frequency of 9.4 T–400 MHz. Computational analysis using the finite-difference time-domain method was used to assess the single-channel surface RF coil by comparing single-channel surface RF coils of varying sizes in terms of |B1|-, |B1+|-, |B1−|- and |E|-field distribution. RF safety for the prevention of burn injuries to small animals was assessed using an analysis of the specific absorption rate. A single-channel surface RF coil with a 20 mm diameter provided optimal B1-field distribution and RF safety, thus confirming that single-channel surface RF coils with ≥25 mm diameter could not provide typical B1-field distribution. A single-channel surface RF coil with a 20 mm diameter for mouse body imaging at 9.4 T MRI was recommended to preserve the characteristics of single-channel surface RF coils, and ensured that RF signals were applied correctly to the target point within RF safety guidelines.
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Ullrich N, Schröder A, Bauer M, Spanier G, Jantsch J, Deschner J, Proff P, Kirschneck C. The role of HIF-1α in nicotine-induced root and bone resorption during orthodontic tooth movement. Eur J Orthod 2020; 43:516-526. [PMID: 33043973 DOI: 10.1093/ejo/cjaa057] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND In orthodontic tooth movement (OTM), pseudo-inflammatory processes occur that are similar to those of nicotine-induced periodontitis. Previous studies have shown that nicotine accelerates OTM, but induces periodontal bone loss and dental root resorption via synergistically increased osteoclastogenesis. This study aimed to investigate the role of hypoxia-inducible factor 1 alpha (HIF-1α) in nicotine-induced osteoclastogenesis during OTM. MATERIALS/METHODS Male Fischer-344 rats were treated with l-Nicotine (1.89 mg/kg/day s.c., N = 10) or NaCl solution (N = 10). After a week of premedication, a NiTi spring was inserted to mesialize the first upper left molar. The extent of dental root resorption, osteoclastogenesis, and HIF-1α protein expression was determined by (immuno)histology, as well as bone volume (BV/TV) and trabecular thickness (TbTh) using µCT. Receptor activator of nuclear factor of activated B-cells ligand (RANK-L), osteoprotegerin (OPG), and HIF-1α expression were examined at the protein level in periodontal ligament fibroblasts (PDLF) exposed to pressure, nicotine and/or hypoxia, as well as PDLF-induced osteoclastogenesis in co-culture experiments with osteoclast progenitor cells. RESULTS Nicotine favoured dental root resorptions and osteoclastogenesis during OTM, while BV/TV and TbTh were only influenced by force. This nicotine-induced increase does not appear to be mediated by HIF-1α, since HIF-1α was stabilized by force application and hypoxia, but not by nicotine. The in vitro data showed that the hypoxia-induced increase in RANK-L/OPG expression ratio and PDLF-mediated osteoclastogenesis was less pronounced than the nicotine-induced increase. CONCLUSIONS Study results indicate that the nicotine-induced increase in osteoclastogenesis and periodontal bone resorption during OTM may not be mediated by hypoxic effects or HIF-1α stabilization in the context of nicotine-induced vasoconstriction, but rather by an alternative mechanism.
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Affiliation(s)
- Niklas Ullrich
- Department of Orthodontics, University Medical Centre of Regensburg, Germany
| | - Agnes Schröder
- Department of Orthodontics, University Medical Centre of Regensburg, Germany
| | - Maria Bauer
- Department of Orthodontics, University Medical Centre of Regensburg, Germany
| | - Gerrit Spanier
- Department of Oral and Maxillofacial Surgery, University Medical Centre of Regensburg, Germany
| | - Jonathan Jantsch
- Department of Medical Microbiology and Hygiene, University Medical Centre of Regensburg, Germany
| | - James Deschner
- Department of Periodontology and Operative Dentistry, University Medicine Mainz, Germany
| | - Peter Proff
- Department of Orthodontics, University Medical Centre of Regensburg, Germany
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Buduneli N, Scott DA. Tobacco-induced suppression of the vascular response to dental plaque. Mol Oral Microbiol 2018; 33:271-282. [PMID: 29768735 PMCID: PMC8246627 DOI: 10.1111/omi.12228] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/02/2018] [Indexed: 12/26/2022]
Abstract
Cigarette smoking presents oral health professionals with a clinical and research conundrum: reduced periodontal vascular responsiveness to the oral biofilm accompanied by increased susceptibility to destructive periodontal diseases. This presents a significant problem, hampering diagnosis and complicating treatment planning. The aim of this review is to summarize contemporary hypotheses that help to explain mechanistically the phenomenon of a suppressed bleeding response to dysbiotic plaque in the periodontia of smokers. The influence of smoke exposure on angiogenesis, innate cell function, the production of inflammatory mediators including cytokines and proteases, tobacco-bacteria interactions, and potential genetic predisposition are discussed.
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Affiliation(s)
| | - David A. Scott
- Department of Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, KY, USA
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Kirschneck C, Maurer M, Wolf M, Reicheneder C, Proff P. Regular nicotine intake increased tooth movement velocity, osteoclastogenesis and orthodontically induced dental root resorptions in a rat model. Int J Oral Sci 2018; 9:174-184. [PMID: 28960194 PMCID: PMC5709548 DOI: 10.1038/ijos.2017.34] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/01/2017] [Indexed: 12/25/2022] Open
Abstract
Orthodontic forces have been reported to significantly increase nicotine-induced periodontal bone loss. At present, however, it is unknown, which further (side) effects can be expected during orthodontic treatment at a nicotine exposure corresponding to that of an average European smoker. 63 male Fischer344 rats were randomized in three consecutive experiments of 21 animals each (A/B/C) to 3 experimental groups (7 rats, 1/2/3): (A) cone-beam-computed tomography (CBCT); (B) histology/serology; (C) reverse-transcription quantitative real-time polymerase chain reaction (RT-qPCR)/cotinine serology—(1) control; (2) orthodontic tooth movement (OTM) of the first and second upper left molar (NiTi closed coil spring, 0.25 N); (3) OTM with 1.89 mg·kg−1 per day s.c. of L(−)-nicotine. After 14 days of OTM, serum cotinine and IL-6 concentration as well as orthodontically induced inflammatory root resorption (OIIRR), osteoclast activity (histology), orthodontic tooth movement velocity (CBCT, within 14 and 28 days of OTM) and relative gene expression of known inflammatory and osteoclast markers were quantified in the dental-periodontal tissue (RT–qPCR). Animals exposed to nicotine showed significantly heightened serum cotinine and IL-6 levels corresponding to those of regular European smokers. Both the extent of root resorption, osteoclast activity, orthodontic tooth movement and gene expression of inflammatory and osteoclast markers were significantly increased compared to controls with and without OTM under the influence of nicotine. We conclude that apart from increased periodontal bone loss, a progression of dental root resorption and accelerated orthodontic tooth movement are to be anticipated during orthodontic therapy, if nicotine consumption is present. Thus patients should be informed about these risks and the necessity of nicotine abstinence during treatment.
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Affiliation(s)
- Christian Kirschneck
- Department of Orthodontics, University Medical Centre of Regensburg, Regensburg, Germany
| | - Michael Maurer
- Department of Oral and Maxillofacial Surgery, University Medical Centre of Regensburg, Regensburg, Germany
| | - Michael Wolf
- Department of Orthodontics, Rheinische Friedrich Wilhelm University of Bonn, Bonn, Germany
| | - Claudia Reicheneder
- Department of Orthodontics, University Medical Centre of Regensburg, Regensburg, Germany
| | - Peter Proff
- Department of Orthodontics, University Medical Centre of Regensburg, Regensburg, Germany
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Garcia VG, Gualberto EC, Ervolino E, Nagata MJH, de Almeida JM, Theodoro LH. aPDT for periodontitis treatment in ovariectomized rats under systemic nicotine. Photodiagnosis Photodyn Ther 2018; 22:70-78. [DOI: 10.1016/j.pdpdt.2018.02.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Revised: 02/18/2018] [Accepted: 02/21/2018] [Indexed: 01/04/2023]
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Pasupuleti MK, Molahally SS, Salwaji S. Ethical guidelines, animal profile, various animal models used in periodontal research with alternatives and future perspectives. J Indian Soc Periodontol 2016; 20:360-368. [PMID: 28298815 PMCID: PMC5341308 DOI: 10.4103/0972-124x.186931] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Laboratory animal models serve as a facilitator to investigate the etiopathogenesis of periodontal disease, are used to know the efficacy of reconstructive and regenerative procedures, and are also helpful in evaluation of newer therapeutic techniques including laser and implant therapies prior to application in the human beings. The aim of this review is to know the different animal models used in various specialties of dental research and to know the ethical guidelines prior to the usage of experimental models with main emphasis on how to refine, replace, and reduce the number of animal models usage in the laboratory. An online search for experimental animal models used in dental research was performed using MEDLINE/PubMed database. Publications from 2009 to May 2013 in the specialty of periodontics were included in writing this review. A total of 652 references were published in PubMed/MEDLINE databases based on the search terms used. Out of 245 studies, 241 were related to the periodontal research published in English from 2009 to 2013. Relevant papers were chosen according to the inclusion and exclusion criteria. After extensive electronic and hand search on animal models, it has been observed that various animal models were used in dental research. Search on animal models used for dental research purpose revealed that various animals such as rats, mice, guinea pigs, rabbit, beagle dogs, goats, and nonhuman primates were extensively used. However, with the new advancement of ex vivo animal models, it has become easy to investigate disease pathogenesis and to test the efficacy of newer therapeutic modalities with the reduced usage of animal models. This review summarized the large amount of literature on animal models used in periodontal research with main emphasis on ethical guidelines and on reducing the animal model usage in future perspective.
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Affiliation(s)
- Mohan Kumar Pasupuleti
- Department of Periodontics, St. Joseph Dental College, Duggirala, Eluru, West Godavari, Andhra Pradesh, India
| | | | - Supraja Salwaji
- Department of Oral and Maxillofacial Pathology, St. Joseph Dental College, Duggirala, Eluru, West Godavari, Andhra Pradesh, India
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Sadaoka S, Yagami K, Maki S. Nicotine in cigarettes promotes chromogranin A production by human periodontal ligament fibroblasts. Arch Oral Biol 2013; 58:1029-33. [DOI: 10.1016/j.archoralbio.2013.02.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 12/29/2012] [Accepted: 02/26/2013] [Indexed: 01/07/2023]
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Deliaert AEK, Van den Kerckhove E, Tuinder S, Noordzij SMJS, Dormaar TS, van der Hulst RRWJ. Smoking and its effect on scar healing. EUROPEAN JOURNAL OF PLASTIC SURGERY 2012; 35:421-424. [PMID: 22661831 PMCID: PMC3353110 DOI: 10.1007/s00238-011-0661-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2011] [Accepted: 11/09/2011] [Indexed: 12/26/2022]
Abstract
Scar formation is influenced by several factors such as wound infection, tension, wound depth and anatomical localization. Hypertrophic scarring is often the result of an imbalance in the wound and scar healing process. The exact underlying pathophysiological mechanism remains unclear. Smoking has a higher risk of postoperative complications probably due to a diminished macrophage induction. Following our clinical impression that smokers without postoperative wound infections show esthetically better scars, we evaluated the scars after a reduction mammaplasty in smoking and nonsmoking patients in a prospective clinical trial. Between July 2006 and September 2007, 13 smokers and 30 non smokers with a reduction mammaplasty were included. They were recruited from Viecuri Medical Centre and Atrium Medical Centre in the Netherlands after written consent. Surgical data and data of the patients' condition were collected. Follow-up for erythema values of the scars was done with a colorimeter (The Minolta CR-300, Minolta Camera Co., Ltd., Osaka Japan) at 1, 3, 6 and 9 months postoperatively on four standardized postsurgical sites. ANOVA and Chi-square test were used for statistical analysis. In the smoking group, the scars were significantly less red compared to the nonsmoking group. No significant differences were found in BMI, resection weight and drain production between both groups. Although smoking is certainly not recommended as a preventive therapy to influence scar healing, this study confirms our assumption that smokers tend to have faster and less erythemateous scar healing to nonsmokers. Further research is needed to understand the mechanism of the effect of smoking on scars.
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Affiliation(s)
- A. E. K. Deliaert
- Department of Plastic Surgery, Maastricht University Medical Centre, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands
| | - E. Van den Kerckhove
- Department of Plastic Surgery, Maastricht University Medical Centre, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands
- Department of Rehabilitation Sciences and Kinesiology, Katholieke Universiteit Leuven, Leuven, Belgium
- Department of Physical Medicine and Rehabilitation and Burns Center, Katholieke Universiteit Leuven, Leuven, Belgium
| | - S. Tuinder
- Department of Plastic Surgery, Maastricht University Medical Centre, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands
| | - S. M. J. S. Noordzij
- Department of Radiology, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - T. S. Dormaar
- Department of Plastic Surgery Viecuri Medical Centre, Venlo, The Netherlands
| | - R. R. W. J. van der Hulst
- Department of Plastic Surgery, Maastricht University Medical Centre, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands
- Department of Plastic Surgery Viecuri Medical Centre, Venlo, The Netherlands
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Zhang Z, Bai X, Du K, Huang Y, Wang W, Zhao Y, Pei Y, Mu J, Han H, Hu S, Li S, Dong H, Lu Y, Hou L, Xiong L. Activation of cholinergic anti-inflammatory pathway contributes to the protective effects of 100% oxygen inhalation on zymosan-induced generalized inflammation in mice. J Surg Res 2011; 174:e75-83. [PMID: 22261596 DOI: 10.1016/j.jss.2011.10.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 10/14/2011] [Accepted: 10/26/2011] [Indexed: 10/15/2022]
Abstract
BACKGROUND The 100% oxygen inhalation has been demonstrated to have a protective effect on mice with zymosan-induced generalized inflammation. However, the underlying mechanism is largely unknown. The present study was designed to explore the role of the cholinergic anti-inflammatory pathway in this animal model. METHODS Oxygen inhalation was given to mice at 4 and 12 h after zymosan injection. One group of mice underwent vagotomy 7 d before zymosan injection. The other two groups of mice either received nicotinic acetylcholine receptor (nAChR) antagonist mecamylamine, or α7 nicotinic acetylcholine receptor (α7nAChR) antagonist methyllycaconitine 30 min before oxygen was given. RESULTS The 100% oxygen treatment significantly decreased the serum level of TNF-α and increased the serum level of IL-10. The pathologic changes of the heart, lung, liver, and kidney were attenuated, as well as the dysfunction of liver and kidney. The 7-d survival rate of zymosan-challenged mice was also improved. Conversely, all these protective effects caused by pure oxygen treatment were abolished in those animals that received anti-cholinergic treatments. CONCLUSIONS The cholinergic anti-inflammatory pathway may be involved in the 100% oxygen protective mechanism against zymosan-induced generalized inflammation in mice.
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Affiliation(s)
- Zishen Zhang
- Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi Province, PR China
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Gonçalves RB, Coletta RD, Silvério KG, Benevides L, Casati MZ, da Silva JS, Nociti FH. Impact of smoking on inflammation: overview of molecular mechanisms. Inflamm Res 2011; 60:409-24. [PMID: 21298317 DOI: 10.1007/s00011-011-0308-7] [Citation(s) in RCA: 203] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 11/25/2010] [Accepted: 01/03/2011] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Inflammation is a critical component of normal tissue repair, as well as being fundamental to the body's defense against infection. Environmental factors, such as smoking, have been reported to modify the host response and hence modify inflammation progression, severity and outcome. Therefore, a comprehensive understanding of the molecular mechanisms by which smoking affects inflammation is vital for preventive and therapeutic strategies on a clinical level. AIM The purpose of the present article is to review the potential biological mechanisms by which smoking affects inflammation, emphasizing recent developments. RESULTS Smoking is reported to effect a number of biological mediators of inflammation through its effect on immune-inflammatory cells, leading to an immunosuppressant state. Recent evidence strongly suggests that the molecular mechanisms behind the modulation of inflammation by smoking mainly involve the nuclear factor-kappa B (NF-kB) family, through the activation of both an inhibitor of IkB kinase (IKK)-dependent and -independent pathway. In addition to NF-kB activation, a number of transcriptional factors including GATA, PAX5 and Smad 3/4, have also been implicated. CONCLUSION Multiple mechanisms may be responsible for the association of smoking and inflammation, and the identification of potential therapeutic targets should guide future research.
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Affiliation(s)
- R B Gonçalves
- Department of Periodontology and Research Group in Oral Ecology, Faculty of Dentistry, Laval University, Quebec City, Canada
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