Objectives: This study aimed to estimate the prevalence of Internet addiction (IA) among Korean adolescents and examine its association with psychiatric comorbidities and mental health symptoms. Methods: A total of 270 adolescents and their parents participated in this study. Parents completed the Internet Addiction Proneness Scale for Youth: Observer Version and the Diagnostic Predictive Scales, whereas adolescents completed the Center for Epidemiological Studies Depression Scale for Children, the Screen for Child Anxiety-Related Disorders, and the Youth Self-Report. Group differences in psychiatric disorders and mental health symptoms across IA levels were analyzed. Results: Of the participants, 86.3% were classified as general, 11.1% as potential high risk, and 2.6% as high risk for IA. The high risk IA group exhibited significantly higher rates of attention-deficit/hyperactivity disorder (42.9%), major depressive disorder (26.3%), and social anxiety (14.3%) as well as greater attentional and social difficulties. Effect sizes for group differences were small to moderate (ε2 = 0.041 for social problems; ε2 =0.033 for attentional problems). IA scores were positively correlated with attentional difficulties and anxiety. Anxiety was a significant predictor of IA in the regression analysis. Conclusion Adolescents with high IA risk exhibited elevated psychiatric comorbidities and mental health difficulties, with anxiety showing an independent association with IA. These findings suggest incorporating anxiety-management components into IA prevention and care. Given the small sample size of the high risk IA group, caution is warranted when generalizing these findings.

Hypercalcemia is a common clinical problem. The most frequent causes of hypercalcemia include primary hyperparathyroidism and malignancy; systemic lupus erythematosus (SLE) is a very rare cause of hypercalcemia. Here we describe a case of symptomatic severe hypercalcemia, which developed during a lupus flare. After treatment with intravenous fluids, diuretics, pamidronate, and hemodialysis, calcium levels normalized and were maintained on low-dose prednisolone treatment. To the best of our knowledge, this is the first case of hypercalcemia in a patient with SLE in Korea. Clinicians should consider lupus as a differential diagnosis for patients with severe hypercalcemia.
Calcium ; Diagnosis, Differential ; Diuretics ; Humans ; Hypercalcemia* ; Hyperparathyroidism, Primary ; Korea ; Lupus Erythematosus, Systemic* ; Parathyroid Hormone-Related Protein ; Prednisolone ; Renal Dialysis

Aged ; Contrast Media ; adverse effects ; Electrocardiography ; Heart Arrest ; therapy ; Humans ; Male ; Myocardial Infarction ; therapy

PURPOSE: To demonstrate the superficial hyperechoic band (SHEB) in articular cartilage by using ultrasonography (US) and to assess its correlation with histological images. METHODS: In total, 47 regions of interest (ROIs) were analyzed from six tibial osteochondral specimens (OCSs) that were obtained after total knee arthroplasty. Ultrasonograms were obtained for each OCS. Then, matching histological sections from all specimens were obtained for comparison with the ultrasonograms. Two types of histological staining were used: Safranin-O stain (SO) to identify glycosaminoglycans (GAG) and Masson's trichrome stain (MT) to identify collagen. In step 1, two observers evaluated whether there was an SHEB in each ROI. In step 2, the two observers evaluated which histological staining method correlated better with the SHEB by using the ImageJ software. RESULTS: In step 1 of the analysis, 20 out of 47 ROIs showed an SHEB (42.6%, kappa=0.579). Step 2 showed that the SHEB correlated significantly better with the topographical variation in stainability in SO staining, indicating the GAG distribution, than with MT staining, indicating the collagen distribution (P<0.05, kappa=0.722). CONCLUSION: The SHEB that is frequently seen in human articular cartilage on high-resolution US correlated better with variations in SO staining than with variations in MT staining. Thus, we suggest that a SHEB is predominantly related to changes in GAG. Identifying an SHEB by US is a promising method for assessing the thickness of articular cartilage or for monitoring early osteoarthritis.
Arthroplasty ; Cartilage ; Cartilage, Articular* ; Collagen ; Glycosaminoglycans ; Humans ; Knee ; Knee Joint ; Osteoarthritis ; Ultrasonography*

Placental site trophoblastic tumor (PSTT) is a rare form of gestational trophoblastic tumor (GTT) that has different behavior in disease process. The hysterectomy is general for PSTT, but hysterectomy is undesirable for patients who wish to remain fertile. We planned to preserve fertility of a young patient by first administering EMA/CO (Etoposide, methotrexate, actinomycin D/cyclophosphamide, vincristine) chemotherapy and then performing an open uterine surgery to remove residual tumor. The patient who attempted primary chemotherapy for PSTT must be undergone a hysterectomy because this conservative regimen showed sign of chemoresistance. We report a case of chemoresistant PSTT with trial to preserve fertility with a brief review of literatures.
Dactinomycin ; Drug Therapy ; Fertility ; Humans ; Hysterectomy ; Methotrexate ; Neoplasm, Residual ; Trophoblastic Neoplasms ; Trophoblastic Tumor, Placental Site*

The authors would like to amend a reference (Lee et al., 2003) that was cited in "Cell culture" section of "Materials and Methods". Instead of "(Lee et al., 2003)", we would like to change the reference to "(Kim et al., 2003)". In "References", it also needs to include the following reference. Kim YY, Seol HW, Ahn HJ. Temporal expression of differentiation markers in embryoid bodies from various human embryonic stem cell line. International Society for Stem Cell Research 1st Annual Meeting, Washington, DC. U.S.A. June 8-11, 2003, Abstract No. 35. The authors apologize for any inconvenience.

Human embryonic stem (hES) cells are capable of differentiating into pluralistic cell types, however, spontaneous differentiation generally gives rise to a limited number of specific differentiated cell types and a large degree of cell heterogeneity. In an effort to increase the efficiency of specified hES cell differentiation, we performed a series of transient transfection of hES cells with EGFP expression vectors driven by different promoter systems, including human cellular polypeptide chain elongation factor 1 alpha (hEF1alpha), human cytomegalo-virus, and chicken beta-actin. All these promoters were found to lead reporter gene expression in undifferentiated hES cells, but very few drug-selectable transfectants were obtained and failed to maintain stable expression of the transgene with either chemical or electroporation methods. In an attempt to increase transfection efficiency and obtain stable transgene expression, differentiated hES cells expressing both mesodermal and ectodermal markers were derived using a defined medium. Differentiated hES cells were electroporated with a hEF1alpha promoter-driven EGFP or human noggin expression vector. Using RT-PCR, immunocytochemistry and fluorescence microscopy, the differentiated hES cells transfected with foreign genes were confirmed to retain stable gene and protein expression during prolonged culture. These results may provide a new tool for introducing exogenous genes readily into hES cells, thereby facilitating more directed differentiation into specific and homogenous cell populations.
Actins/genetics ; Animals ; Bone Morphogenetic Proteins/genetics ; *Cell Differentiation ; Chickens ; Cytomegalovirus/genetics ; Drug Delivery Systems ; Embryo/*cytology ; *Gene Therapy ; Green Fluorescent Proteins/genetics/*metabolism ; Humans ; Immunoenzyme Techniques ; Microscopy, Fluorescence ; Peptide Elongation Factor 1/genetics ; Pluripotent Stem Cells/*cytology ; Promoter Regions (Genetics)/*genetics ; Research Support, Non-U.S. Gov't ; Reverse Transcriptase Polymerase Chain Reaction ; Transcription, Genetic/genetics

BACKGROUND: The studies on cryopreserved arterial allograft have been focused on cooling methods, pre-treatment, cryoprotectant agents, and preservation temperature. But recently, several studies have reported that thawing methods also play an important role in the occurrence of macroscopic and microscopic cracks. This study was designed to investigate the cell injury after thawing, using a rabbit model to clarify the effect of thawing methods on cryopreserved arteries. MATERIAL AND METHOD: Segments of the rabbit aorta were obtained and divided into 3 groups (n=60) according to whether the specimens were fresh (control, n=20), cryopreserved and rapidly thawed (RT) at 37oC (n=20), or cryopreserved and subjected to controlled, automated slow thawing (ST)(n=20). Cell damage was established using the TUNEL method and the morphological changes were also evaluated. RESULT: In the group that was rapidly thawed, the expression of TUNEL (+) cells increased significantly more than in the slowly thawed group. In addition, the endothelial denudation, microvesicles and edema were significant in the rapidly thawed group compared with those changes in the slowly thawed group. CONCLUSION: Our study suggests that the rapid thawing method may be one of the major causes of cellular damage and delayed rupture in cryopreserved arterial allografts. The expression of TUNEL (+) cells and structural changes were significantly low in the slowly thawed group, which might have contributed to the improvement of graft failure after transplantation.
Allografts ; Aorta* ; Arteries ; Cryopreservation ; Edema ; In Situ Nick-End Labeling ; Rupture ; Transplants

BACKGROUND: Tricuspid regurgitation has been considered as a secondary lesion when it is combined with left valvular heart diseases. However, there have been some reports which show that tricuspid regurgitation keeps going and results in congestive heart failure even after a successful operation for left valvular heart disease. So far, there are no definite operation indications and predictive factors for the tricuspid regurgitation which is resulted from the left sided valvular heart disease. We designed this study to evaluate the effects of pulmonary artery pressure and left ventricular ejection fraction on the prognosis of tricuspid regurgitation, and to make an operation indication for the patients with secondary tricuspid regurgitation. MATERIAL AND METHOD: We reviewed the medical records of patients who underwent surgery for the left sided valvular heart disease with tricuspid regurgitation and were followed for more than 1 year with echocardiograms. There was a total of 114 cases. We compared the grades of tricuspid regurgitations and pulmonary artery pressures and left ventricular ejection fractions on the basis of echocardiograms which were checked preoperatively and on the last follow up. RESULT: There were 43 cases of tricuspid annuloplasty. In these patients, the grades of tricuspid regurgitations were improved in 42 cases (97.7%). But in 71 cases without annuloplasty, 29 cases (41%) were improved, 32 cases (45%) had no change, and 10 cases (14%) were aggravated. This finding shows significant differences in the prognoses of tricuspid regurgitations between the two groups (p<0.05). There was no difference in pulmonary artery pressures and ejection fractions between the patients who showed progression of tricuspid regurgitations and those who didn't (p>0.05). The improvements of tricuspid regurgitations are not statistically related to the changes of pulmonary artery pressures or left ventricular ejection fractions. CONCLUSION: This study shows that it is impossible to predict the prognoses of tricuspid regurgitations with preoperative pulmonary artery pressures or left ventricular ejection fractions. Also, the excellent results of tricuspid annuloplasty is proven in controlling the secondary tricuspid regurgitations. Therefore, when tricuspid regurgitation is detected preoperatively, the procedures to correct the tricuspid regurgitation at the time of the operation for the left-sided valvular heart disease must be considered positively, regardless of the grades of tricuspid regurgitations, to prevent significant tricuspid regurgitation that may develop later.
Follow-Up Studies ; Heart Failure ; Heart Valve Diseases* ; Humans ; Medical Records ; Prognosis* ; Pulmonary Artery ; Stroke Volume ; Tricuspid Valve Insufficiency*

BACKGROUND: The pulmonary nodules (PN), when indicated, need thoracoscopic resection, especially in cases of non-diagnostic or technically infeasible PCNA (percutaneous needle aspiration). In the difficult situations of small or deeply seated PN, several techniques facilitating thoracoscopy have been used for detecting them. Our new protocol for managing PN was developed and prospectively reviewed. MATERIAL AND METHOD: In the procedure of PCNA, we firstly placed the tip of the needle in the center of, or just in contact with PN under CT guidance, and loaded one or two segments of platinum radiomarker inside the needle after removing the stylet. Then, we forced the radiomarker to move to the tip of the needle by pushing the stylet. Finally, if the tip of the needle was not within PN, it was reoriented to the their center to obtain the sample for PCNA. RESULT: Between May 1999 and May 2000, radiomarkers were successfully placed in 28 PN of 26 patients, with the exception of one. In 18 (85%) of 21 nodules needing throacoscopy, intraoperative fluoroscopy was used to detect them or guide stapling resection during thoracoscopy. CONCLUSION: The advantages of this technique are that there is that there is no need for further localization for thoracoscopy even in cases of unsuccessful PCNA, and it was more effective in respect to both cost and time. Therefore, this strategy for PN expecting thoracoscopy will be helpful to patients and medical staff alike.
Fluoroscopy ; Humans ; Medical Staff ; Needles ; Platinum ; Proliferating Cell Nuclear Antigen ; Prospective Studies ; Thoracoscopy