Search

Summary Costello syndrome (CS) is an autosomal dominant disorder caused by mutations in HRAS. Although CS patients have skeletal abnormalities, the role of mutated HRAS in bone development remains unclear. Here, we use CS induced pluripotent stem cells (iPSCs) undergoing osteogenic differentiation to investigate how dysregulation of extracellular matrix (ECM) remodeling proteins contributes to impaired osteogenesis. Although CS patient-derived iPSCs develop normally to produce mesenchymal stem cells (MSCs), the resulting CS MSCs show defective osteogenesis with reduced alkaline phosphatase activity and lower levels of bone mineralization. We found that hyperactivation of SMAD3 signaling during the osteogenic differentiation of CS MSCs leads to aberrant expression of ECM remodeling proteins such as MMP13, TIMP1, and TIMP2. CS MSCs undergoing osteogenic differentiation also show reduced β-catenin signaling. Knockdown of TIMPs permits normal differentiation of CS MSCs into osteoblasts and enhances β-catenin signaling in a RUNX2-independent manner. Thus, this study demonstrates that enhanced TIMP expression induced by hyperactivated SMAD3 signaling impairs the osteogenic development of CS MSCs via an inactivation of β-catenin signaling., Highlights • Enhanced p-SMAD3 signaling dysregulates ECM remodeling proteins in CS osteoblasts • Overexpression of TIMPs impairs osteogenesis of CS MSCs independent of RUNX2 • Elevated level of TIMPs reduces β-catenin activity and OSX expression • Gene correction of CS iPSCs reverts defective osteogenesis, In this article, Han and colleagues suggest new insights into the mechanisms by which mutated HRASG12S induces the bone abnormalities observed in CS patients. Furthermore, they suggest a model in which ECM remodeling proteins (MMP13, TIMP1, and TIMP2) and their related pathways (HRAS-MAPK, TGF-β, and β-catenin) help explain the impaired osteogenesis of CS MSCs.

Aims To investigate the intent to leave or stay among Korean hospital nurses, and to identify what factors influence their intent to leave or stay. Background Previous studies have simply measured nurses' intent to leave or stay; however, this study examines the associations of intent to leave and intent to stay with influential factors among Korean hospital nurses. Methods A cross-sectional study was conducted with 267 nurses working at four general hospitals in South Korea. Result The influencing factors on intent to leave were organisational commitment, practice environment and burnout, while intent to stay was influenced by organisational commitment. Conclusion The study demonstrates that, for Korean hospital nurses, intent to leave and intent to stay are not simply contrary concepts, but are different concepts influenced by varying factors. Implications for nursing management This study clarifies the difference between the concepts of intent to stay and intent to leave, and demonstrates that the variables affecting Korean nurses' intent to stay and intent to leave differ from each other. Therefore, focusing on improving nurses' intent to either leave or stay would be effective when developing personnel management policies for nurses, thereby contributing to enhancing nursing practice.

To evaluate the prevalence and risk factors of Clonorchis sinensis infection, an epidemiologic survey was performed (3,169 residents; age range: 30-87 years; mean age = 59; 1,973 women) in three areas with different mortality rates of cholangiocarcinoma. C. sinensis prevalence was 2.1% in Chuncheon, 7.8% in Chungju, and 31.3% in Haman, where cholangiocarcinoma incidence rate was 0.3, 1.8, and 5.5 per 100,000 persons, respectively. Of the four major risk factors for C. sinensis (male sex, alcohol consumption, raw freshwater fish intake, and area of residence), area was the strongest. Efforts to discourage raw freshwater fish intake, treat egg carriers, and protect water sources from C. sinensis contamination should be strengthened in the Republic of Korea.

Background. Little is known about the prevalence of human papillomavirus (HPV) infection in young adults in Asia. Methods. We invited female and male students in Busan, South Korea, to participate in a survey that included, for females, self-collection of vaginal cells and, for males, physician-performed collection of exfoliated genital cells. The prevalences of 25 HPV types were evaluated, by a polymerase chain reaction-based assay, in 672 female students (median age, 19 years) and in 381 male students (median age, 22 years). Results. HPV DNA was detected more frequently in female students (15.2%) than in male students (8.7%); in both sexes, high-risk HPV types were predominant. Among sexually active students, HPV prevalence was 38.8% in females and 10.6% in males. In female students, currently smoking cigarettes and having multiple lifetime sex partners were the strongest risk factors for HPV infection; in male students, associations between HPV prevalence and sexual habits were similar to those in female students but never attained statistical significance. Conclusions. Young women in South Korea start having penetrative sexual intercourse relatively late (median age, 18 years), but, once they begin, HPV prevalence quickly rises to levels comparable with those found in university students in the United States and in northern Europe. The high rate of participation in our study suggests that trials of new vaccines against HPV may be feasible among university students in South Korea.

To investigate the prevalence of hepatitis B and C virus infections and determine the associated risk factors among young adults in Busan, Korea, which is known to have a high incidence of liver cancer.The study population consisted of volunteer participants in a health survey during 2002, which included 1, 350 students (515 males and 835 females) aged between 16 and 24 years, from three different schools in Busan. The participating students were asked to fill in a selfadministered questionnaire which included lifestyle habits and risk factors of hepatitis. Sera obtained from the participants were studied for HBsAg, anti-HBs, and Anti- HCV by enzyme immunoassay (EIA) method and for liver function tests.Among the study subjects (N=1, 350), the seropositivities of HBsAg 7.9% (95% CI=7.8-8.0), 7.6% (95% CI=7.6-7.7) in male and 8.1% (95% CI=8.0-8.2) in female. And the seropositivity of Anti-HBs was 69.7% (95% CI=69.0- 70.4), 70.5% (95% CI=69.8-71.2) in male and 69.2% (95% CI=68.5-69.9) in female. The seropositivity of Anti-HCV was 0.4%, 0.2% in male and 0.5% in female. The seropositivity for HBsAg in the subjects not having a hepatitis B vaccination history was twice (95% CI=1.0-4.4) that of those that did. Also, the seropositivity for HBsAg in subjects having experienced sexual intercourse was 1.7 times (95% CI=0.9-3.0) that of the subjects who had not.The present study confirmed the high prevalence of HBsAg seropositivity and sexual transmission of HBV among adolescents and young adults may occur. Further studies to evaluate the relationship between HBV vaccination and sexual transmission are required for the young population in Korea.

Background: In areas where hepatitis is endemic, little is known about the sexual transmission of HBV after introduction of an HBV vaccination program.Methods: We used a self-administered questionnaire and serological tests for HBsAg, anti-HBs, anti-HBc, and anti-HCV to examine the role of sexual activity, as well as sociodemographic status, lifestyle habits, and a history of vaccinations, transfusions, and surgery, in the transmission of HBV and HCV in Korea. The subjects were 865 female and 541 male university students (median age, 19 years; age range, 16–25).Results: Overall seropositivity was 8.1% for HBsAg, 69.3% for anti-HBs, 21.3% for anti-HBc, and 0.4% for anti-HCV. Regarding HBV, 8% of the subjects were chronic carriers or had recently been infected, 22.8% were never exposed and nonvaccinated, 16.6% were exposed noncarriers, and 52.7% had most likely been vaccinated. We found a significant association between HBsAg seropositivity and history of sexual intercourse (Odds Ratio, 1.8; 95% CI, 1.1–2.8). Students without serologic evidence of immunization against HBV were more likely to have become HBsAg-positive after becoming sexually active.Conclusions: Our findings suggest that sexual transmission does occur among adolescents and young adults who have not been vaccinated, whereas vaccination protects individuals from becoming an HBV carrier after becoming sexually active.

Cervical cancer screening with the conventional Papanicolaou test is recommended for the women aged 30 years and more in Korea. Cervical infection with human papillomavirus (HPV) is the most important cause of cervical cancer and Chlamydia trachomatis (CT) is the most common bacterial sexually transmitted infection and may also be associated with risk of cervical cancer. A cross-sectional study of women attending the National Cervical Cancer Screening Program in Busan and Suwon was carried out. Exfoliated cervical cells were collected, and questionnaires were administered to 4595 women. High-risk HPV types and CT were tested by Hybrid Capture 2 (HC2). HPV genotyping of 355 high-risk HPV-positive women at HC2 was performed using linear array. Age-standardized prevalence of high-risk HPV types and CT was 10.4% (95% confidence interval: 9.5-11.3) and 4.3% (95% confidence interval: 3.7-4.8). That 68.5% of women were high-risk HPV-positive at HC2 was confirmed by Linear Array whereas 17.5% seemed to be infected with only low-risk HPV types, not normally detected by HC2. Korean women showed a relatively high prevalence of high-risk HPV and a rather low prevalence of CT. As in cancer-free women in other Asian populations, HPV 52, 58, and 39 were detected more frequently than HPV 16. Cross-reaction of HC2 with low-risk HPV types is of some concern, were the test to be used in primary screening.

In the absence of genital samples, human papillomavirus (HPV) serology may be useful to assess HPV infection in young men and women. HPV seroprevalence and determinants of seropositivity were assessed in 817 female and 518 male university students in Busan, South Korea, of whom 74% and 44%, respectively, reported never having had penetrative sexual intercourse. Type-specific HPV DNA status, assessed by a short PCR fragment primer set, was available from genital samples. Seropositivity to L1 proteins of HPV types 16, 18, 31, 33, 45, 52, and 58 were assessed using multiplex HPV serology. Among women, HPV seroprevalence was significantly higher among sexually active (26.1%) than nonsexually active students [11.1%, odds ratio (OR) = 2.9; 95% confidence interval (95% CI), 1.8-4.7], although the association was weaker than that for HPV DNA prevalence (OR, 14; 95% CI, 4.7-42). Furthermore, HPV seroprevalence was higher among HPV DNA-positive (24%) than HPV DNA-negative women (13%), and there was a positive correlation of type-specific seroprevalence with the presence of HPV DNA of the same type. In contrast, HPV seropositivity among men was not associated with sexual behavior or the presence of HPV DNA. Seroprevalence correlates with genital HPV exposure in young women, but its meaning in young men is unclear. (Cancer Epidemiol Biomarkers Prev 2007;16(9):1874–9)

To investigate the prevalence of Clonorchis sinensis infestation and to determine the associated risk factors among a population in a part of the rural area of Gyeongsangnam-do, Korea, which is an area known to have a high mortality from liver cancer and a high infection of C. sinensis.The study population consisted of those people who have lived in rural areas and who were over 40 years old. This study was performed in 5 areas during the period from 1999 to 2003. Informed consents were obtained from the 2,381 study participants, and these people were interviewed about their life style habits with using the structured questionnaire that was administered by trained staff members. The subjects underwent blood sampling and their stool specimens were examined by using the Formalin-ether sedimentation technique.Among the study subjects (N=2,381), the positivity for C. sinensis in the stool was 34.4% (95% CI= 36.3-42.5); it was 39.4% (95% CI=36.3-42.5) in the males and 30.9% (95% CI=28.5-33.3) in the females. The positivity for C. sinensis was associated with current alcohol drinking (odds ratio=1.8, 95% CI: 1.5-2.1) and raw fish consumption (odds ratio 1.2, 95% CI: 0.9-1.6).The present study confirmed the high prevalence of C. sinensis in the study subjects. It is necessary to establish consistent medical management and education programs for the treatment and prevention of C. sinensis infestation in the rural inhabitants of Korea.

Purpose: The purpose of this study was to facilitate home visits to assess the current rate of child abuse in order to provide an agenda for the early detection and prevention of child abuse and neglect in Korea. Methods: For this retrospective descriptive research, 20 public health centers were selected, 1,991 families were visited and 2,680 children were assessed. Results: We found 415 cases (15.5%) of potential abuse and 7 cases (0.3%) of actual abuse. The greatest risk group was to children age 4 to 6 years. According to the HOME Inventory, there were 17 infants (5.8%) presenting a potential risk for child abuse and neglect. Conclusion: Visitation screening is highly recommended for prevention in the high-risk preschool age group.