Nuclear structure in Parity Doublet Model

Using an extended parity doublet model with the hidden local symmetry, we study the properties of nuclei in the mean field approximation to see if the parity doublet model could reproduce nuclear properties and also to estimate the value of the chiral invariant nucleon mass $m_0$ preferred by nuclear structure. We first determined our model parameters using the inputs from free space and from nuclear matter properties. Then, we study some basic nuclear properties such as the nuclear binding energy with several different choices of the chiral invariant mass. We observe that our results, especially the nuclear binding energy, approach the experimental values as $m_0$ is increased until $m_0=700$ MeV and start to deviate more from the experiments afterwards with $m_0$ larger than $m_0=700$ MeV, which may imply that $m_0=700$ MeV is preferred by some nuclear properties.Comment: 8 pages, 2 figure

Toxocariasis Might be an Important Cause of Atopic Myelitis in Korea

Atopic myelitis is defined as myelitis with atopic diasthesis but the cause is still unknown. Toxocariasis is one of the common causes of hyperIgEaemia that may lead to neurologic manifestations. The purpose of this study was to evaluate the sero-prevalence of Toxocara specific IgG Ab among the atopic myelitis patients. We evaluated the medical records of 37 patients with atopic myelitis whose conditions were diagnosed between March 2001 and August 2007. Among them, the 33 sera were analyzed for specific serum IgG Ab to Toxocara excretory-secretory antigens (TES). All of 37 patients had hyperIgEaemia. Specific IgE to D. pteronyssinus and D. farinae was detected in 22 (64.7%) and 34 (100%) patients, respectively, of the 34 patients. Thirty-one of 33 patients (93.9%) were found to be positive by TES IgG enzyme-linked immunosorbent assay (ELISA). Based on the image findings of eosinophilic infiltrations in the lung and liver, 8 patients had positive results. These results inferred that the prevalence of toxocariasis was high in patients with atopic myelitis. Our results suggest that toxocariasis might be an important cause of atopic myelitis and Toxocara ELISA is essential for evaluating the causes of atopic myelitis

Volume stability of the augmented sinus using a collagenated bovine bone mineral grafted in case of a perforated Schneiderian membrane: An experimental study in rabbits

Objectives: To determine the volume stability of a sinus augmented with a collagenated bovine bone mineral (CBBM) in case of an intact or perforated Schneiderian membrane (SM). Materials and methods: A bilateral sinus augmentation procedure was performed in eight rabbits. The SM was intentionally perforated in one side (SMP group), while it remained intact in contra-lateral side (control group) and the same amount of CBBM was then grafted. At 12 weeks, the animals were euthanized for radiographic and histomorphometric analyses. Results: The augmented volume did not differ significantly between the two groups: 262.2 ± 32.1 mm3 in SMP group and 261.9 ± 48.5 mm3 in the control group (p = .959). There was no significant difference in the total augmented area: 24.7 ± 5.2 mm2 in SMP group and 23.2 ± 2.9 mm2 in the control group (p = .773). The areas of newly formed bone also did not differ significantly between the two groups, but was significantly lower at the centre of the augmented region than in the region of the surgical window in both groups (p < .05). Conclusion: A perforation of the SM in a rabbit model does neither impact the augmented volume nor new bone formation following grafting of the sinus with a CBBM. Keywords: Schneiderian membrane; animal study; volume stability; xenograft. © 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

Dimensional changes of the maxillary sinus augmented with a collagenated synthetic bone block or synthetic bone particulates: A pre-clinical study in rabbits

OBJECTIVE to compare the efficacy of a collagenated synthetic bone substitute (C-SBS) to a particulated synthetic bone substitute (P-SBS) in volume maintenance and new bone formations in a rabbit sinus model. MATERIALS AND METHODS Either C-SBS or P-SBS was grafted in both sinuses of 16 rabbits. Four (N = 8) or 12 (N = 8) weeks after the surgery, total augmented volume (TAV) and area (TAA), as well as new bone volume (NBV) and area (NBA), were statistically compared by radiographic and histomomertric analyses (p < 0.05). RESULTS The differences in TAV, NBV, TAA and NBA between C-SBS and P-SBS groups at 4 weeks were not statistically significant. The TAV (267.13 ± 62.08 vs. 200.18 ± 40.32 mm$^{3}$ ) and NBV (103.26 ± 10.50 vs. 71.10 ± 7.58 mm$^{3}$ ) in group C-SBS were significantly higher than in group P-SBS at 12 weeks (p < 0.05). The TAA (19.36 ± 2.88 vs. 14.48 ± 2.08 mm$^{2}$ ) and NBA (5.43 ± 1.20 vs. 3.76 ± 0.78 mm2) in group C-SBS were significantly higher than in group P-SBS at 12 weeks (p < 0.05). CONCLUSIONS C-SBS grafted in rabbit sinuses demonstrated more favorable outcomes across all outcome measures compared to P-SBS at 12 weeks

Effect of collagen membrane and of bone substitute on lateral bone augmentation with titanium mesh: An experimental in vivo study

AIM The aim of this study was to identify the additional effects of collagen membrane (CM) and of synthetic bone substitute (BS) on lateral bone augmentation of chronic peri-implant defect with titanium mesh (TM). MATERIALS AND METHODS Atrophic alveolar ridge was induced in six canine mandibles, and 5 peri-implant defects were achieved in each hemi-mandible. Bone augmentation was attempted using the following randomly allocated modalities: (1) Control: no treatment, (2) TM only group: blood clot covered by TM, (3) TM+BS group: BS covered by TM, (4) TM+CM group: blood clot covered by TM and CM, and (5) TM+BS+CM group: BS covered by TM and CM. After 16 weeks of submerged healing, micro-CT and histomorphometric analyses were performed. RESULTS TM exposure occurred in one case in the TM only group, one case in the TM+CM group, and two cases in the TM+BS+CM group. Histologically, pseudo-periosteum was observed along the inner and outer surfaces of TM, and the directions of the collagen fiber within the pseudo-periosteum differed according to the additional use of CM. In general, the TM only group rendered higher values in vertical defect fill and dimension of the augmented hard tissue in comparison with the other treatment groups. CONCLUSIONS Due to the small sample size, this pilot study remains inconclusive. Within the limitations of the study, the use of CM and/or BS did not appear to have an additional benefit on lateral bone augmentation of peri-implant defect with TM

Secondary stability achieved in dental implants with a calcium-coated sandblasted, large-grit, acid-etched (SLA) surface and a chemically modified SLA surface placed without mechanical engagement: A preclinical study

OBJECTIVES To assess the osseointegration of calcium-coated (CS) and chemically modified, sandblasted, large-grit, acid-etched (MS) dental implants with a lack of primary mechanical stability. MATERIALS AND METHODS Eighteen implants in CS and MS groups each were loosely placed in the mandible of six mongrel dogs and allowed to heal for 2, 4 and 8 weeks. Implant stability quotient (ISQ) and implant stability test (IST) values recorded periodically and bone-to-implant contact (BIC) and the number of Haversian canals per 1 mm$^{2}$ measured histologically were statistically analysed (p < .05). RESULTS All CS and MS implants placed survived. Compared with immediately after installation, ISQ and IST values in both groups increased significantly to over 76 at 2 weeks (p < .0083) and remained stable thereafter. BIC was significantly greater at 8 weeks (61.3 ± 13.6% in CS group; 57.6 ± 5.9% in MS group) compared to 2 and 4 weeks in both groups (p < .017). There were no significant intergroup differences in ISQ, IST or BIC at different time points. Significantly more Haversian canals were observed in group CS (6.2 ± 1.0/mm$^{2}$ ) compared with group MS at 4 weeks (3.7 ± 1.8 /mm$^{2}$ ; p < .05), while intergroup difference was not significant at 8 weeks. CONCLUSION Both CS and MS implants inserted without primary stability obtained osseointegration within 2 weeks, and lamellar bone adjacent to the implants was first observed at 8 weeks. The formation of primary osteons was more active at 4 weeks in group CS than in group MS

Immediate versus delayed application of bone morphogenetic protein-2 solution in damaged extraction sockets: a preclinical in vivo investigation

Objective: To compare the clinical, radiographic, and histological healing patterns between the immediate and delayed applications of bone morphogenetic protein-2 (BMP-2) in damaged extraction sockets in dogs. Materials and methods: The distal roots of the fourth premolars of the mandible were extracted bilaterally in five beagle dogs, and buccal bone defects (4 mm wide and 9 mm high) were surgically created. Collagenated biphasic calcium phosphate (CBCP) soaked for 10 min in 100 μL of BMP-2 solution was applied immediately to the defect site in the control group. In the test group, the BMP-2 solution of same dose was injected into the grafted site 2 weeks after grafting with a saline-soaked CBCP. The dogs were sacrificed 2 weeks later. Clinical, histological, and radiographic analyses were followed. Results: Swelling and inflammatory reactions were predominantly observed in the control group at 2 weeks. The area of new bone formation was significantly larger in the control group compared with the test group (10.8 ± 7.0 mm2 [mean ± SD] and 6.3 ± 3.1 mm2, respectively; p = 0.043). No significant difference was found in ridge width at 2 mm, 4 mm and 6 mm below the lingual bone crest between the control (2.6 ± 1.0 mm, 3.2 ± 0.9 mm and 4.5 ± 0.5 mm, respectively) and test group (3.3 ± 1.0 mm, 3.7 ± 1.3 mm and 4.2 ± 1.0 mm; all p > 0.05). Conclusions: Delayed application of BMP-2 2 weeks after surgery did not show any advantage over immediate application of BMP-2 in terms of new bone formation. Clinical relevance: This study suggests that it might be better to apply BMP-2 immediately in alveolar ridge preservation, instead of delayed application, in order to enhance new bone formation. Keywords: Alveolar ridge augmentation; Animal experimentation; Bone morphogenetic protein 2; Bone substitutes; Damaged extraction socket; Extraction socket regeneration; Tooth extraction

Efficacy of Local Minocycline Agents in Treating Peri-Implantitis: An Experimental In Vivo Study in Beagle Dogs

Background: Local delivery agents (LDA) have the advantage of delivering the antibiotics at high concentrations to the targeted sites. However, the constant flow of gingival crevicular fluids and saliva may restrict their efficacy. Therefore, the drug sustainability and pharmacodynamic properties of any proposed LDA should be evaluated. Methods: Four dental implants were placed unilaterally in the edentulous mandible of six beagle dogs. Peri-implantitis were experimentally induced using silk-ligatures. Each implant was randomly allocated to receive one of the following four treatments: (i) MC (Chitosan-alginate (CA) minocycline), (ii) MP (CA-without minocycline), (iii) PG (Polyacrylate-glycerin minocycline), and (iv) Control (mechanical debridement only). Mechanical therapies and LDAs were administered into the gingival sulcus two times at a 4-week interval. Drug sustainability as well as clinical, radiographical, and immunohistochemical (IHC) analyses were conducted to evaluate the efficacies of treatments. Results: Reduced mean probing depth was observed in all of the test groups after the second delivery. A minimal marginal bone level change was observed during the treatment period (MP (&minus;0.06 &plusmn; 0.53 mm) to PG (&minus;0.25 &plusmn; 0.42 mm)). The distribution of IHC cell marker analysis of all targeted antibodies ranged from 6.34% to 11.33%. All treatment outcomes between the test groups were comparable. A prolonged retention of LDA was observed from CA microspheres (MC and MP) at both administrations (p &lt; 0.017) and prolonged sustainability of bacteriostatic effect was observed from MC compared to PG after the second administration (p &lt; 0.05). Conclusions: Prolonged retention of CA microspheres was observed and the longer bacteriostatic effect was observed from the MC group. Mechanical debridement with adjunct LDA therapy may impede peri-implantitis progression, however, prolonged drug action did not lead to improved treatment outcome

Comparison of maximal elastance and systolic wall thickening using arterial tonometry and gated myocardial SPECT in patients undergoing coronary artery bypass grafting

Myocardial SPECT using (99m)Tc-sestamibi, (99m)Tc-tetrofosmin, (201)Thallium is widely used in nuclear cardiology. Left ventricular systolic wall thickening (SWT) by SPECT and regional maximal elastance (rE(max)) using arterial tonometry were compared. rE(max) was calculated from time-pressure and time-volume curves. In normal heart, improvement of SWT was 4.1 +/- 11%, while 6.0 +/- 16% in dilated heart. Improvement of rE(max) was 0.67 +/- 1.0 mmHg/mL in normal heart and 0.32 +/- 0.7 mmHg/mL in dilated heart (p < 0.05). rE(max) can be an alternative variable as an index of regional contractility. (C) 2009 Elsevier Ltd. All rights reserved.This studywassupportedbyClinicalResearchInstituteSeoul NationalUniversityHospital(04-2006-015-0).Nakajima K, 2007, EUR J NUCL MED MOL I, V34, P1088, DOI 10.1007/s00259-006-0321-1Suga H, 2003, CLIN EXP PHARMACOL P, V30, P580Suga H, 2003, J BIOMECH, V36, P713, DOI 10.1016/S0021-9290(02)00449-9LEE E, 2003, PLOS BIOL, V1, P10LEE BI, 2003, KOREAN J NUCL MED, V37, P355LEE BI, 2002, P IEEE MIC M10 29Sharir T, 2001, J NUCL MED, V42, P1630Paeng JC, 2001, J NUCL MED, V42, P695KIM KM, 2001, KOREAN J NUCL MED, V35, P152Lee DS, 1999, J NUCL CARDIOL, V6, P657Germano G, 1997, J AM COLL CARDIOL, V30, P1360SENZAKI H, 1996, CIRCULATION, V94, P506GERMANO G, 1995, J NUCL MED, V36, P2138SUGA H, 1994, JPN HEART J, V35, P263

Development of a sodium/iodide symporter (NIS)-transgenic mouse for imaging of cardiomyocyte-specific reporter gene expression

Development of a small animal imaging system for differentiated cell-specific reporter gene expression will enable us to image cellular differentiation in vivo. In this study, we developed a sodium/iodide symporter (NIS)-transgenic mouse in which NIS is constitutively expressed as an imaging reporter gene only in cardiomyocytes. METHODS: To express NIS gene in cardiomyocytes, alpha-myosin heavy chain (alpha-MHC)-NIS was constructed and used for the production of NIS-transgenic mice. Twelve lines of positive founder were obtained. The adequacy of the transgenic mouse model was tested by in vivo scintigraphy, microPET, and a biodistribution study. RESULTS: The myocardium of transgenic mice showed rapid and intense uptake of 131I, which was much higher than that of the thyroid, and also showed long retention by gamma-camera pinhole imaging. The relative uptake ratio of the heart of transgenic mice was 4.6 +/- 1.5, which was 3.8 +/- 1.2 times higher than that of control wild-type mice. The uptake of the heart was completely blocked by oral administration of KClO4, an NIS inhibitor. The heart of transgenic mouse was also clearly and intensely visualized on microPET using 124I. Biodistribution data of these mice showed the uptake of 40-160 %ID/g (percentage injected dose per gram of tissue) of (99m)Tc-pertechnetate in the heart compared with 40-60 %ID/g in the stomach, respectively. NIS expression in the myocardium was confirmed by immunohistochemistry using a NIS-specific antibody. CONCLUSION: We developed a transgenic mouse model to image cardiomyocytes with a gamma-camera and microPET using an alpha-MHC promoter and NIS. The transgenic mouse can be used as an imaging model for cardiomyocyte-specific reporter gene expression and cellular differentiation into cardiomyocytes after cardiac stem or progenitor cell transplantation