External validation of risk prediction platforms for pancreatic fistula after pancreatoduodenectomy using nomograms and artificial intelligence

Purpose@#Postoperative pancreatic fistula (POPF) is a life-threatening complication following pancreatoduodenectomy (PD).We previously developed nomogram- and artificial intelligence (AI)-based risk prediction platforms for POPF after PD. This study aims to externally validate these platforms. @*Methods@#Between January 2007 and December 2016, a total of 1,576 patients who underwent PD in Seoul National University Hospital, Ilsan Paik Hospital, and Boramae Medical Center were retrospectively reviewed. The individual risk scores for POPF were calculated using each platform by Samsung Medical Center. The predictive ability was evaluated using a receiver operating characteristic curve and the area under the curve (AUC). The optimal predictive value was obtained via backward elimination in accordance with the results from the AI development process. @*Results@#The AUC of the nomogram after external validation was 0.679 (P < 0.001). The values of AUC after backward elimination in the AI model varied from 0.585 to 0.672. A total of 13 risk factors represented the maximal AUC of 0.672 (P < 0.001). @*Conclusion@#We performed external validation of previously developed platforms for predicting POPF. Further research is needed to investigate other potential risk factors and thereby improve the predictability of the platform.

A 4-Axis Technique for Three-Dimensional Printing of an Artificial Trachea

BACKGROUND: Several types of three-dimensional (3D)-printed tracheal scaffolds have been reported. Nonetheless, most of these studies concentrated only on application of the final product to an in vivo animal study and could not show the effects of various 3D printing methods, materials, or parameters for creation of an optimal 3D-printed tracheal scaffold. The purpose of this study was to characterize polycaprolactone (PCL) tracheal scaffolds 3D-printed by the 4-axis fused deposition modeling (FDM) method and determine the differences in the scaffold depending on the additive manufacturing method. METHODS: The standard 3D trachea model for FDM was applied to a 4-axis FDM scaffold and conventional FDM scaffold. The scaffold morphology, mechanical properties, porosity, and cytotoxicity were evaluated. Scaffolds were implanted into a 7 × 10-mm artificial tracheal defect in rabbits. Four and 8 weeks after the operation, the reconstructed sites were evaluated by bronchoscopic, radiological, and histological analyses. RESULTS: The 4-axis FDM provided greater dimensional accuracy and was significantly closer to CAD software-based designs with a predefined pore size and pore interconnectivity as compared to the conventional scaffold. The 4-axis tracheal scaffold showed superior mechanical properties. CONCLUSION: We suggest that the 4-axis FDM process is more suitable for the development of an accurate and mechanically superior trachea scaffold.

The Effects of Service Orientation on the Organizational Commitment and Management Performance of Public Health Center Workers / 한국직업건강간호학회지

PURPOSE: The purpose of this study was to identify the effects of service orientation on the organizational commitment and management performance of public health center workers. METHODS: A cross-sectional survey design was used. A convenience sample of 280 workers was recruited from six public health centers in J province, South Korea. Data were collected by self-report questionnaires, including general characteristics, service orientation, organizational commitment, and management performance. Data were analyzed with descriptive statistics, Pearson correlation coefficients, independent t-test, one-way ANOVA, and hierarchical regression using the SPSS 22.0 program. RESULTS: The service orientations explained 34.1%of the variance in organizational commitment and explained 31.4% of the variance in management performance. The service orientation was a significant predictor of organizational commitment and management performance. CONCLUSION: The results of this study suggest that better strategies for service orientations will be helpful to enhance organizational commitment and management performance in the public health center.

Application of a Collagen Patch Derived from Duck Feet in Acute Tympanic Membrane Perforation

We investigated the utility of the duck-feet collagen extraction patching procedure in the traumatic tympanic membrane (TM) perforation via a comparison with spontaneous healing or paper patch. Fifty-six ears of adult male Sprague-Dawley rats, each weighing in the range of 250 to 300 g, were used for the animal studies. Sixteen rats had one-side ear in the control group and the opposite-side ear in the treated groups. The remaining twelve rats had a one-side ear with the duck-feet collagen patch and the opposite-side ear with a paper patch. The proliferating cell nuclear antigen (PCNA) expression cells were calculated among the 200 basal cells, and the expression percentage was identified as the labeling index. The healing of the perforation in the duck-feet collagen patch group was confirmed to be more rapid compared to the healing of the other groups. PCNA staining was observed in the migrating portion of PCNA enhanced cell to collagen scaffold in Post operative day (POD) 7 of collagen patch group. Thus, the adhesive effect of the duck-feet collagen patch to perforated margin was better than that of the paper patch. After completing the healing process, the collagen patch shrank and detached from the tympanic membrane (POD 14). In this study, we confirmed that the use of a duck-feet collagen patch had the advantage of early healing, inducing natural TM contour, and disappearing ability after the patch effect is complete.

Fabrication and Characterization of Hydrocolloid Dressing with Silk Fibroin Nanoparticles for Wound Healing

Hydrocolloid dressings have been developed for many types of wound healing. In particular, dressing is a critical component in the successful recover of burn injuries, which causes a great number of people to not only suffer from physical but also psychological and economic anguish each year. Additionally, silk fibroin is the safest material for tissue engineering due to biocompatibility. In this study, we fabricated hydrocolloid dressings incorporating silk fibroin nanoparticles to enhance the efficacy of hydrocolloid dressing and then use this silk fibroin nanoparticle hydrocolloid dressing (SFNHD) in animal models to treat burn wounds. The structures and properties of SFNHD were characterized using tensile strength and Cell Counting Kit-8 assay. The results indicated the structural stability and the cellular biocompatibility of the hydrocolloid dressing suggesting that SFNHD can be applied to the treatment of wounds. To demonstrate the capacity of a silk fibroin hydrocolloid dressing to treat burn wounds, we compared SFNHD to gauze and Neoderm®, a commercially available dressing. This study clearly demonstrated accelerated wound healing with greater wound structural integrity and minimal wound size after treatment with SFNHD. These observations indicate that SFNHD may be an improvement upon current standard dressings such as Gauze and Neoderm® for burn wounds.

Factors Predicting Hypocalcemia after Total Thyroidectomy with Central Lymph Node Dissection in Papillary Thyroid Cancer / 대한내분비외과학회지

PURPOSE: Total thyroidectomy with central lymph node dissection (CLND) is a treatment modality of choice for thyroid cancer. Hypocalcemia is the most common complication after total thyroidectomy. The aim of the current study was to determine the association between surgery-related clinical factors and postoperative hypocalcemia. METHODS: A prospective analysis was performed for 101 patients who underwent total thyroidectomy with CLND for papillary cancer from June 2013 to June 2014. Correlation between clinicopathologic factors and postoperative hypocalcemia was analyzed. RESULTS: Based on the postoperative day-2 calcium, 56 patients (55%) developed hypocalcemia and 45 patients (45%) were normal. No significant differences in histopathologic (tumor size, tumor focality, histologic type, number of retrieved lymph nodes, metastatic lymph node, thyroiditis, retrieved parathyroid gland) findings were observed between the hypocalcemia group and normal calcium group. Mean value of the postoperative day-0 parathyroid hormone (PTH) was significantly lower in the hypocalcemia group (hypoca1cemia group: 14.3+/-9.4 pg/mL; normal group: 25.0+/-16.4 pg/mL; P<0.001). In logistic regression analysis, postoperative PTH was a factor significantly affecting postoperative hypocalcemia (OR 0.93; CI: 0.90-0.97; P<0.001). In ROC analysis, the cut-off value of PTH was 19.965 (sensitivity 79%, specificity 58%), and area under the curve (AUC) was 0.709 (95% CI: 0.607-0.811). CONCLUSION: Postoperative PTH was a factor predicting hypocalcemia after total thyroidectomy with CLND. Use of postoperative PTH as a screening tool for prediction of postoperative hypocalcemia would be useful in management of patients with hypocalcemia.

Validity and Reliability of a Service Orientation Scale for Health Care Organization / 간호행정학회지

PURPOSE: The purpose of this research was to develop and test the validity and reliability of the Service Orientation Scale for Health Care Organization. METHODS: The Service Orientation Scale for Health Care Organization, SERV*OR, was developed through forward-backward translation methods. Internal consistency and reliability, construct and criterion validity were calculated using SPSS Statistics WIN 17.0. Survey data were collected from 283 clinical nurses in a general hospital in J province. RESULTS: The Service Orientation Scale for Health Care Organization showed reliable internal consistency with Cronbach's alpha's for the total scale ranging from .85~.91. Factor loading of the 30 items on four sub-scales ranged from .67~.83. The sub scales were named service leadership, service system, customer focus, and service control. Item convergent and discriminant validity were also established for the Service Orientation Scale for Health Care Organization. Criterion validity showed a significant correlation with customer orientation. CONCLUSION: The findings of the study demonstrate that the Service Orientation Scale for Health Care Organization has satisfactory construct and criterion validity, and reliability and can be used to measure service orientation.

Analysis of Facial Deformities in Korean Leprosy

OBJECTIVES: The clinical features of various facial deformities in Korean leprosy patients were evaluated according to the type of leprosy. METHODS: One hundred ninety six patients with leprosy were examined for various facial deformities using a nasal speculum, endoscope, and digital camera. The frequency and severity of external nasal deformities and septal perforations were evaluated according to the type of leprosy. Eye deformities, ear deformities, and facial palsy were also assessed. RESULTS: Seventy-one patients (36.2%) displayed external nasal deformities: 28 minimal contractures, three cartilage contractures, two bony-cartilage contractures, and 38 skin defects. The external nasal deformity and severe form deformity in lepromatous types were more frequent compared to other types (P0.05 for each variable). Sixty-one patients (31.1%) had eye deformities and 19 patients (9.7%) had facial nerve palsy, common in the borderline type. No cases of ear deformities were observed. CONCLUSION: Korean patients had characteristic deformities according to the type of leprosy. They were different from those seen in the prior analyses of Caucasian populations.

xCITED2 Induces Neural Genes in Animal Cap Explants of Xenopus Embryos

Neural tissue is arisen from presumptive ectoderm via inhibition of bone morphogenetic protein (BMP) signaling during Xenopus early development. Previous studies demonstrate that ectopic expression of dominant negative BMP4 receptor (DNBR) produces neural tissue in animal cap explants (AC) and also increases the expression level of various genes involved in neurogenesis. To investigate detail mechanism of neurogenesis in transcriptional level, we analyzed RNAs increased by DNBR using total RNA sequencing analysis and identified several candidate genes. Among them, xCITED2 (Xenopus CBP/p300-interacting transcription activator) was induced 4.6 fold by DNBR and preferentially expressed in neural tissues at tadpole stage. Ectopic expression of xCITED2 induced anterior neural genes without mesoderm induction and reduced BMP downstream genes, an eye specific marker and posterior neural marker. Taken together, these results suggest that xCITED2 may have a role in the differentiation of anterior neural tissue during Xenopus early development.

Isolation of Early Neurogenesis Genes with Xenopus cDNA Microarray / 한국실험동물학회지

Neurogenesis is the process that develops neuroectoderm from ectoderm. Bone morphogenetic protein (BMP) inhibition in ectodermal cells is necessary and sufficient for neurogenesis in Xenopus embryos. To isolate genes involved in early neurogenesis, Xenous Affymetrix gene chips representing 14,400 genes were analyzed in early stage of neuroectodermal cells that were produced by inhibition of BMP signaling with overexpression of a dominant-negative receptor. We identified 265 candidate genes including 107 ESTs which were newly expressed during the early neurogenesis by blocking BMP signaling. The candidates of 10 ESTs were selected and examined for upregulation in neuroectoderm. Five EST genes were confirmed to be upregulated in neuroectoderm and examined for time-dependent expression patterns in intact embryos. Two EST genes were cloned and identified as a homology of CYP26c (Xl.1946.1.A1_at) and Kielin containing VWC domain (Xl.15853.1.A1_at). One of them, CYP26c, was further characterized for its transcriptional regulation and role of anterior-posterior patterning during neurogenesis. Taken together, we analyzed and characterized genes expressed in early neurogenesis. The results suggest that neurogenesis by inhibition of BMP provides useful system to isolate genes involved in early events of neurogenesis during early vertebrate embryogenesis.

Aging and UV Irradiation Related Changes of Gene Expression in Primary Human Keratinocytes

The epidermis is a physiological barrier to protect organisms against environment. During the aging process, skin tissues undergo various changes including morphological and functional changes. The transcriptional regulation of genes is part of cellular reaction of aging process. In order to examine the changes of gene expression during the aging process, we used the primary cell culture system of human keratinocytes. Since UV radiation is the most important environmental skin aggressor, causing skin cancer and other problems including premature skin aging, we examined the changes of gene expression in human keratinocytes after UV irradiation using oligonucleotide microarray containing over 10,000 genes. We also compared the gene expression patterns of the senescent and UV treated cells. Expression of the variety of genes related to transcription factors, cell cycle regulation, immune response was altered in human keratinocytes. Some of down-regulated genes are represented in both senescent and UV treated cells. The results may provide a new view of gene expression following UVB exposure and aging process in human keratinocytes.

The characteristics of the five cases of hepatic eosinophilic abscess / 대한내과학회지

Hepatic eosinophilic abscess is a very rare disease which has been reported in fascioliasis, and some gastrointestinal malignancy. We experienced 5 cases with hepatic eosinophilic abscesses which were caused by unknown etiology, confirmed by liver biopsy, from 1990 to 1994. The chracteristics of the cases including clinical menifestations, serologic findings, ultrasonography and abdominal computerizes tomogram(CT) were summerized. They had no characteristic findings except eosinophilia in clinical menifestations and they showed various ultrasonographic and CT findings which are different from the radiologic findings of liver abscesses by bacterial or amebic infection. We think that hepatic eosinophilic abscess must be included in differential diagnosis of all hepatic tumors.