• Title/Summary/Keyword: Model surgery

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Characteristics of Patients with Surgical Closure of an Atrial Septal Defect during Infancy

  • Byeong A Yoo;Su Jin Kwon;Yu-Mi Im;Dong-Hee Kim;Eun Seok Choi;Bo Sang Kwon;Chun Soo Park;Tae-Jin Yun
    • Journal of Chest Surgery
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    • v.56 no.3
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    • pp.155-161
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    • 2023
  • Background: Surgical closure of an atrial septal defect (ASD) is infrequently indicated during infancy. We evaluated the clinical characteristics and outcomes of patients who underwent surgical ASD closure during infancy. Methods: A single-center retrospective review was performed for 39 patients (19 males) who underwent surgical ASD closure during infancy between 1993 and 2020. The median body weight percentile at the time of operation was 9.3. Results: During a median follow-up of 60.9 months, 4 late deaths occurred due to chronic respiratory failure. A preoperative history of bronchopulmonary dysplasia (BPD) was the only risk factor for late mortality identified in Cox regression (hazard ratio, 3.54; 95% confidence interval [CI], 1.75-163.04; p=0.015). The 5-year survival rate was significantly lower in patients with preoperative history of BPD (97.0% vs. 50.0%, p<0.001) and preoperative ventilatory support (97.1% vs. 40.4%, p<0.001). There were significant postoperative increases in left ventricular end-diastolic (p=0.017), end-systolic (p=0.014), and stroke volume (p=0.013) indices. A generalized estimated equation model showed significantly better postoperative improvement in body weight percentiles in patients with lower weight percentiles at the time of operation (<10th percentile, p=0.01) and larger indexed ASD diameter (≥45 mm/m2, p=0.025). Conclusion: Patients with ASD necessitating surgical closure during infancy are extremely small preoperatively and remain small even after surgical closure. However, postoperative somatic growth was more prominent in smaller patients with larger defects, which may be attributable to an increase in postoperative cardiac output due to changes in ventricular septal configuration. The benefits of ASD closure in patients with BPD are undetermined.

Semiparametric and Nonparametric Modeling for Matched Studies

  • Kim, In-Young;Cohen, Noah
    • Proceedings of the Korean Statistical Society Conference
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    • 2003.10a
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    • pp.179-182
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    • 2003
  • This study describes a new graphical method for assessing and characterizing effect modification by a matching covariate in matched case-control studies. This method to understand effect modification is based on a semiparametric model using a varying coefficient model. The method allows for nonparametric relationships between effect modification and other covariates, or can be useful in suggesting parametric models. This method can be applied to examining effect modification by any ordered categorical or continuous covariates for which cases have been matched with controls. The method applies to effect modification when causality might be reasonably assumed. An example from veterinary medicine is used to demonstrate our approach. The simulation results show that this method, when based on linear, quadratic and nonparametric effect modification, can be more powerful than both a parametric multiplicative model fit and a fully nonparametric generalized additive model fit.

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Lack of Association of Three Common Polymorphisms in Toll-like receptors (TLRs), TLR2+597T>C, +1350C>T and Arg753Gln with Cancer Risk: a Meta-analysis

  • Yang, Xin;Wang, Xiao-Xiao;Qiu, Man-Tang;Hu, Jing-Wen;Yin, Rong;Xu, Lin;Zhang, Qin
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.10
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    • pp.5871-5876
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    • 2013
  • Background: Single nucleotide polymorphisms (SNPs) occurring in Toll-like receptors (TLRs) may contribute to cancer risk. Many polymorphisms of TLR2 have been studied for associations, but the findings are conflicting. Methodology/Principal Findings: We performed a meta-analysis of 14 studies to confirm the association between TLR2+597T>C (rs3804099), +1350C>T (rs3804100) and Arg753Gln (rs5743708) polymorphisms and cancer risk. Odds ratio (OR) and 95% confidence intervals (95% CI) were used to assess the strength of associations. There was no significant association between TLR2+597T>C and cancer risk in the codominant models (CC vs. TT: OR = 1.01, 95%CI = 0.86-1.17, $P_{heterogeneity}=0.148$; CT vs. TT: OR = 0.92, 95%CI = 0.69-1.23, $P_{heterogeneity}$ < 0.001), the recessive model (CC vs. CT+TT: OR = 0.86, 95%CI = 0.67-1.10, $P_{heterogeneity}=0.007$), the dominant model (CC+CT vs. TT: OR = 0.93, 95%CI = 0.76-1.15, $P_{heterogeneity}=0.001$) and the allele model (C vs. T: OR =0.93, 95%CI = 0.81-1.08, $P_{heterogeneity}=0.019$). Similarly, no significant associations between TLR2+1350C>T, Arg753Gln polymorphisms and cancer risk were found. However, in the sub-group analysis of ethnicities, the trend of pooled ORs in Asians was opposite to Caucasians. Conclusions: The present meta-analysis suggests that TLR2+597T>C (rs3804099), +1350C>T (rs3804100) and Arg753Gln (rs5743708) polymorphisms are not associated with cancer risk.

Development of 3D Printing System for Human Bone Model Manufacturing Using Medical Images (의료 영상을 이용한 인체 골 모형 제작의 3차원 프린팅 시스템 개발)

  • Oh, Wang-Kyun
    • Journal of radiological science and technology
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    • v.40 no.3
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    • pp.433-441
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    • 2017
  • The 3D printing selective laser sintering (SLS) and stereo lithography apparatus (SLA) method used for bone model production has good precision and resolution, but the printers are expensive and need professional knowledge for operation. The program that converts computed tomography digital imaging and communications in medicine (DICOM) file into STL (stereolithography) file is also expensive so requesting 3D printing companies takes a lot of time and cost, which is why they are not generally utilized in surgery. To produce bone models of fractured patients, the use of 3D imaging conversion program and 3D printing system should be convenient, and the cost of device and operation should be low. Besides, they should be able to produce big size bone models for application to surgery. Therefore, by using an fused deposition modeling (FDM) method 3D printer that uses thermoplastic materials such as DICOM Viewer OsiriX and plastic wires, this study developed 3D printing system for Fracture surgery Patients customized bone model production for many clinics to use for surgery of fracture patients by universalizing with no limit in printing sizes and low maintenance and production cost. It is expected to be widely applied to the overall areas of orthopedics' education, research and clinic. It is also expected to be conveniently used in not only university hospitals but also regular general hospitals.

Effect of Zhongyi paste on inflammatory pain in mice by regulation of the extracellular regulated protein kinases 1/2-cyclooxygenase-2-prostaglandin E2 pathway

  • Xiao, Ailan;Wu, Chuncao;Kuang, Lei;Lu, Weizhong;Zhao, Xin;Kuang, Zhiping;Hao, Na
    • The Korean Journal of Pain
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    • v.33 no.4
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    • pp.335-343
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    • 2020
  • Background: Zhongyi paste is a traditional Chinese medicine herbal paste that is externally applied to reduce inflammation and relieve pain. Methods: An acute foot swelling inflammation model in C57BL/6J mice was established by carrageenan-induced pathogenesis. Zhongyi paste raised the pain threshold and also reduced the degree of swelling in mice with carrageenan-induced foot swelling. Results: Analysis indicated that serum tumor necrosis factor-alpha, interleukin-1 beta, and prostaglandin E2 (PGE2) cytokine levels and PGE2 levels in the paw tissue of the mice were decreased by Zhongyi paste treatment. The quantitative polymerase chain reaction and western blot results showed that Zhongyi paste downregulated the mRNA and protein expression of extracellular signal-regulated kinase 1/2 (ERK1/2), and cyclooxygenase-2 (COX-2), and also downregulated the mRNA expression of PGE2. At the same time, the Zhongyi paste exerted a stronger effect as an external drug than that of indomethacin, which is an oral drug, and voltaren, which is an externally applied drug. Conclusions: Our results indicated that Zhongyi paste is a very effective drug to reduce inflammatory swelling of the foot, and its mechanism of action is related to regulation of the ERK1/2-COX-2-PGE2 pathway.

Validation of Nafamostat Mesilate as an Anticoagulant in Extracorporeal Membrane Oxygenation: A Large-Animal Experiment

  • Han, Sung Joon;Han, Woosik;Song, Hee-Jung;Kim, Cuk-Seong;Jeong, Seong-Mok;Kang, Min Woong
    • Journal of Chest Surgery
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    • v.51 no.2
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    • pp.114-121
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    • 2018
  • Background: Unfractionated heparin is commonly used for anticoagulation in extracorporeal membrane oxygenation (ECMO). Several studies have shown that nafamostat mesilate (NM) has comparable clinical outcomes to unfractionated heparin. This study compared anticoagulation with NM and heparin in a large-animal model. Methods: Beagle dogs (n=8; weight, 6.5-9 kg) were placed on venovenous ECMO. Blood samples were taken every hour and the following parameters were compared: hemoglobin level, activated partial thromboplastin time (aPTT), thromboelastography (TEG) data, platelet function, and inflammatory cytokine levels. Results: In both groups, the aPTT was longer than the baseline value. Although the aPTT in the NM group was shorter than in the heparin group, the TEG parameters were similar between the 2 groups. Hemoglobin levels decreased in both groups, but the decrease was less with NM than with heparin (p=0.049). Interleukin $(IL)-1{\beta}$ levels significantly decreased in the NM group (p=0.01), but there was no difference in the levels of tumor necrosis factor alpha or IL-10 between the 2 groups. Conclusion: NM showed a similar anticoagulant effect to that of unfractionated heparin, with fewer bleeding complications. NM also had anti-inflammatory properties during ECMO. Based on this preclinical study, NM may be a good alternative candidate for anticoagulation in ECMO.

Growth of Human Colon Cancer Cells in Nude Mice is Delayed by Ketogenic Diet With or Without Omega-3 Fatty Acids and Medium-chain Triglycerides

  • Hao, Guang-Wei;Chen, Yu-Sheng;He, De-Ming;Wang, Hai-Yu;Wu, Guo-Hao;Zhang, Bo
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.5
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    • pp.2061-2068
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    • 2015
  • Background: Tumors are largely unable to metabolize ketone bodies for energy due to various deficiencies in one or both of the key mitochondrial enzymes, which may provide a rationale for therapeutic strategies that inhibit tumor growth by administration of a ketogenic diet with average protein but low in carbohydrates and high in fat. Materials and Methods: Thirty-six male BALB/C nude mice were injected subcutaneously with tumor cells of the colon cancer cell line HCT116. The animals were then randomly split into three feeding groups and fed either a ketogenic diet rich in omega-3 fatty acids and MCT (MKD group; n=12) or lard only (LKD group; n=12) or a standard diet (SD group; n=12) ad libitum. Experiments were ended upon attainment of the target tumor volume of $600mm^3$ to $700mm^3$. The three diets were compared for tumor growth and survival time (interval between tumor cell injection and attainment of target tumor volume). Results: The tumor growth in the MKD and LKD groups was significantly delayed compared to that in the SD group. Conclusions: Application of an unrestricted ketogenic diet delayed tumor growth in a mouse xenograft model. Further studies are needed to address the mechanism of this diet intervention and the impact on other tumor-relevant parameters such as invasion and metastasis.

Narrow-diameter implants with conical connection for restoring the posterior edentulous region

  • Woo, In-Hee;Kim, Ju-Won;Kang, So-Young;Kim, Young-Hee;Yang, Byoung-Eun
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.38
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    • pp.31.1-31.7
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    • 2016
  • Background: The objective of this retrospective study was to show results from platform-switched narrow-diameter implants in the posterior edentulous region, which we followed up for more than 1 year after functional loading. Methods: Ninety-eight narrow implants were inserted into 66 patients. After healing, fixed implant-supported prostheses were delivered to the patients, and Periotest and radiographic examinations were performed. After the first year of loading, the implant outcome was again evaluated clinically and radiographically using the Periotest analysis. Crestal bone loss and Periotest values (PTVs) were used to evaluate the effect of surgery, prosthesis, implant, and a host-related factor. A general linear model was used to statistically detect variables statistically associated with crestal bone loss and Periotest value. Results: We followed up on the implants over 1 to 4 years after loading; their survival rate was 100 %, and pronounced differences from PTVs were noted among jaw location, bone quality, and loading period. No difference was detected in bone loss among the variables studied. Bone loss after functional loading was $0.14{\pm}0.39mm$. The stability value from the Periotest was $-3.29{\pm}0.50$. Conclusions: Within the limitations of this study, judicious use of platform-switched narrow implants with a conical connection must be considered an alternative for wide-diameter implants to restore a posterior edentulous region.