Regulatory role of N-myc downregulated genes in amelogenesis in rats.

Cytodifferentiation of odontogenic cells, a late stage event in odontogenesis is based on gene regulation. However, studies on the identification of the involved genes are scarce. The present study aimed to search for molecules for the cytodifferentiation of ameloblastic cells in rats. Differential display-PCR revealed a differentially expressed gene between cap/early bell stage and hard tissue formation stage in molars. This gene was identified as N-myc Downregulated Gene 1 (Ndrg1), which is the first report in tooth development. Real time PCR and western blotting confirmed that the mRNA level of Ndrg1 was higher during enamel formation than the cap stage. Ndrg1 expression was upregulated in the early bell, crown, and root stages in a time-dependent manner. These patterns of expression were similar in Ndrg2, but Ndrg3 and Ndrg4 levels did not change during the developmental stages. Immunofluorescence revealed that strong immunoreactivity against Ndrg1 were detected in differentiated ameloblasts only, not inner enamel epithelium, odontoblasts and ameloblastic cells in defected enamel regions. Alkaline phosphatase and alizarin red s stains along with real time PCR, revealed that Ndrg1 and Ndrg2 were involved in cytodifferentiation and enamel matrix mineralization by selectively regulating amelogenin and ameloblastin genes in SF2 ameloblastic cells. These results suggest that Ndrg may play a crucial functional role in the cytodifferentiation of ameloblasts for amelogenesis.

Impact of the COVID-19 Pandemic on the Public Perceptions of the Roles and Functions of Community Pharmacies in South Korea: Updated Cross-Sectional Self-Reported Web-Based Survey.

BACKGROUND: Community pharmacists confronted dual burdens in response to the COVID-19 pandemic by expanding the scope of pharmaceutical practices. OBJECTIVE: This study aimed to assess the perceived roles and functions of community pharmacies during the pandemic and to explore their updated roles after the pandemic began. METHODS: We conducted a self-reported web-based survey in October 2022. Based on Korean census data, we recruited the study participants (n=1000) through quota sampling stratified by age, sex, and region, yielding a 7.45% (1000/13,423) response rate. The questionnaires were composed of 3 sections: demographics, the roles and functions of community pharmacies during the pandemic, and the updated roles of community pharmacies during disasters. Each question in the second and third sections was rated on a 5-point Likert scale from 1 (strongly disagree) to 5 (strongly agree), and each item's mean scores and SDs were reported. The study participants were categorized into 2 groups: individuals who had a family pharmacy and those who did not. A chi-square test and ordered logistic regression analyses were conducted. RESULTS: Out of 1000 respondents, 418 (41.8%) had a history of COVID-19, and 639 (63.9%) had a family pharmacy. Assigning specific roles and functions to community pharmacies during the pandemic contributed to positive assessments. Respondents gave higher scores to community pharmacies that had responded appropriately (a mean Likert score of 3.66, SD .077 out of 5) and provided continuous pharmaceutical services (mean 3.67, SD 0.87) during the pandemic. The pandemic served as an opportunity to positively recognize the role of community pharmacies (mean 3.59, SD 0.83). In the ordered logistic model, having a family pharmacy was consistently associated with positive perceptions. Respondents perceived that community pharmacies collaborated with general practitioners and health authorities. However, community pharmacies need to function appropriately in terms of knowledge. The mean score of the 4 domains of community pharmacy functions was the highest for collaboration (mean 3.66, SD 0.83), followed by communication (mean 3.57, SD 0.87), responsiveness (mean 3.54, SD 0.87), and knowledge (mean 3.41, SD 0.91). CONCLUSIONS: The pandemic resulted in interprofessional collaboration between community pharmacists and general practitioners. Family pharmacies could be a valuable asset to the comprehensive case management of patients. However, community pharmacists should have the expertise to build solid interprofessional collaborations and fulfill their expanded and updated roles.

Cost-Effectiveness of Clopidogrel vs Aspirin Monotherapy After Percutaneous Coronary Intervention: Results From the HOST-EXAM Study.

Background: The HOST-EXAM (Harmonizing Optimal Strategy for Treatment of Coronary Artery Disease-Extended Antiplatelet Monotherapy) trial showed superior efficacy and safety of clopidogrel monotherapy compared with aspirin monotherapy during the chronic maintenance period after percutaneous coronary intervention (PCI). Objectives: The goal of this study was to investigate the cost-effectiveness of clopidogrel monotherapy compared with that of aspirin monotherapy. Methods: A Markov model was developed for patients in the stable phase after PCI. From the perspectives of the South Korean, UK, and U.S. health care systems, the lifetime health care costs and quality-adjusted life-years (QALYs) of each strategy were estimated. Transition probabilities were obtained from the HOST-EXAM trial, and health care costs and health-related utilities were obtained from data and literature for each country. Results: From the perspective of the South Korean health care system, the base-case analysis showed that clopidogrel monotherapy was $3,192 higher in lifetime health care costs and 0.139 lower in QALYs compared with aspirin. This result was greatly influenced by the numerically but insignificantly higher cardiovascular mortality of clopidogrel compared with aspirin. In the analogous UK and U.S. models, clopidogrel monotherapy was projected to decrease health care costs by £1,122 and $8,920 per patient compared with aspirin monotherapy while reducing QALYs by 0.103 and 0.175, respectively. Conclusions: Based on empirical data from the HOST-EXAM trial, clopidogrel monotherapy was projected to lead to reduced QALYs compared with aspirin during the chronic maintenance period after PCI. These results were affected by a numerically higher rate of cardiovascular mortality in clopidogrel monotherapy reported from the HOST-EXAM trial. (Harmonizing Optimal Strategy for Treatment of Coronary Artery Stenosis-Extended Antiplatelet Monotherapy [HOST-EXAM]; NCT02044250).

Sclerostin in periodontal ligament: Homeostatic regulator in biophysical force-induced tooth movement.

AIM: To study the role of sclerostin in periodontal ligament (PDL) as a homeostatic regulator in biophysical-force-induced tooth movement (BFTM). MATERIALS AND METHODS: BFTM was performed in rats, followed by microarray, immunofluorescence, in situ hybridization, and real-time polymerase chain reaction for the detection and identification of the molecules. The periodontal space was analysed via micro-computed tomography. Effects on osteoclastogenesis and bone resorption were evaluated in the bone-marrow-derived cells in mice. In vitro human PDL cells were subjected to biophysical forces. RESULTS: In the absence of BFTM, sclerostin was hardly detected in the periodontium except in the PDL and alveolar bone in the furcation region and apex of the molar roots. However, sclerostin was up-regulated in the PDL in vivo by adaptable force, which induced typical transfiguration without changes in periodontal space as well as in vitro PDL cells under compression and tension. In contrast, the sclerostin level was unaffected by heavy force, which caused severe degeneration of the PDL and narrowed periodontal space. Sclerostin inhibited osteoclastogenesis and bone resorption, which corroborates the accelerated tooth movement by the heavy force. CONCLUSIONS: Sclerostin in PDL may be a key homeostatic molecule in the periodontium and a biological target for the therapeutic modulation of BFTM.

Perceived impact of the patent linkage system on pharmaceutical market from the viewpoint of the domestic manufacturers in South Korea.

BACKGROUND: The United States requires a patent linkage system in other countries as part of free trade agreements. However, introducing a patent linkage system could be a significant barrier to the timely approval of generic drugs. This study aimed to evaluate the perceived impact of the patent linkage system in South Korea held by domestic manufacturers and analyze variations in evaluating the system according to the characteristics of domestic manufacturers. METHODS: In 2020, we conducted a questionnaire survey of 39 domestic manufacturers. The survey consisted of perceptions of the system, factors affecting patent challenges, and the perceived impact of the system. A 5-point Likert scale was used to rate each item. Domestic manufacturers were categorized into three groups based on their experience of listing a patent and acquiring first generic exclusivity. RESULTS: More than half of the manufacturers surveyed had experience of listing a patent. The patent linkage system could protect the involved patents. However, manufacturers perceived that they could successfully challenge the validity of the involved patents and then obtained market approval for generic drugs. Manufacturers responded that market size, expectations for succeeding in litigation, and expectations for manufacturing the drug were the most relevant factors when they initiated patent challenges. Manufacturers reported that the system, in particular the first generic exclusivity, enhanced the research and development capability of generic manufacturers, increased their domestic sales, and improved access to generic drugs. CONCLUSIONS: The perceived impact of the patent linkage system was limited to the domestic market and generic drugs. In narrowing the impact to the effects on the domestic industry, the system had positive impacts of the system on generic manufacturers. The first generic drug exclusivity lies at the center of this positive perception. However, manufacturers perceived that the current system did not provide enough incentives for domestic manufacturers to be granted first generic drug exclusivity through patent challenges.

Patent challenges and factors associated with successful patent challengers under the patent linkage system: recent evidence from South Korea after the Korea United States free trade agreement.

OBJECTIVES: The patent linkage system upgraded patent challenges to an important factor in granting timely market approval for generic drugs. We aim to understand patent challenges and identify the factors that are associated with successful patent challengers under the patent linkage system in South Korea. METHODS: We constructed a novel dataset that combined information on manufacturers with detailed data about their patent challenges after introduction of the patent linkage system. Based on the number of successful patent challenges, manufacturers were categorized into non-challengers, passive challengers, and aggressive challengers. Then, two types of logistic models were applied to identify the factors associated with successful and aggressive challengers. FINDINGS: Only 39 active ingredients were challenged by 77 manufacturers from March 2015 to December 2019. Of 171 manufacturers, 94 (55 %) were non-challengers, 58 (34 %) were passive challengers who had succeeded in fewer than 4 patent challenges, and 19 (11 %) were aggressive challengers who had succeeded in 4 or more patent challenges. Higher sales, more employees, and a greater number of reimbursed drugs were associated with being a patent challenger, while a greater number of reimbursed drugs was associated with being an aggressive challenger. CONCLUSION: Some manufacturers utilize patent challenges to strengthen their product portfolios in the market. However, under the patent linkage system, the frequency of patent challenges is limited in South Korea compared to the United States. In particular, patent challenges against drugs in injection form and biologics are very rare.

SLPI in periodontal Ligament is not sleepy during biophysical force-induced tooth movement.

AIM: We aimed to identify a key molecule that maintains periodontal tissue homeostasis during biophysical force-induced tooth movement (BTM) by orchestrating alveolar bone (AB) remodelling. MATERIALS AND METHODS: Differential display-PCR was performed to identify key molecules for BTM in rats. To investigate the localization and expression of the identified molecules, immunofluorescence, real-time RT-PCR and Western blotting were performed in rats and human periodontal ligament (PDL) cells. Functional test and micro-CT analysis were performed to examine the in vivo effects of the identified molecules on BTM. RESULTS: Secretory leucocyte peptidase inhibitor (SLPI) in the PDL was revealed as a key molecule for BTM-induced AB remodelling. SLPI was enhanced in the PDL under both compression and tension, and downregulated by an adenyl cyclases inhibitor. SLPI induced osteoblastogenic genes including runt-related transcription factor 2 (Runx2) and synergistically augmented tension-induced Runx2 expression. SLPI augmented mineralization in PDL cells. SLPI induced osteoclastogenic genes including receptor activator of nuclear factor kappa-Β ligand (RANKL) and synergistically augmented the compression-induced RANKL and macrophage colony-stimulating factor (MCSF) expression. Finally, the in vivo SLPI application into the AB significantly augmented BTM. CONCLUSIONS: SLPI or its inhibitors might serve as a biological target molecule for therapeutic interventions to modulate BTM.

Regulatory role of insulin-like growth factor-binding proteins in odontogenic mineralization in rats.

Much information is currently available for molecules in early odontogenesis, but there is limited knowledge regarding terminal cytodifferentiation of ameloblasts and odontoblasts for the determination of normal crown morphology. The present differential display PCR (DD-PCR) revealed that insulin-like growth factor-binding protein 5 (IGFBP5) was differentially expressed in molar tooth germs between the cap (before crown mineralization) and root formation (after crown mineralization) stages. Real-time PCR confirmed that the expression levels of IGFBP1-4 were not significantly changed but those of IGFBP5-7 were upregulated in a time-dependent manner. Immunoreactivities for IGFBP5-7 were hardly seen in molar germs at the cap/early bell stage and protective-stage ameloblasts at the root formation stage. However, the reactivity was strong in odontoblasts and maturation-stage ameloblasts, which are morphologically and functionally characterized by wide intercellular space and active enamel matrix mineralization. The localization of each IGFBP was temporospatial. IGFBP5 was localized in the nuclei of fully differentiated odontoblasts and ameloblasts, while IGFBP6 was localized in the apical cytoplasm of ameloblasts and odontoblasts with dentinal tubules, and IGFBP7 was mainly found in the whole cytoplasm of odontoblasts and the intercellular space of ameloblasts. IGFBP silencing using specific siRNAs upregulated representative genes for dentinogenesis and amelogenesis, such as DMP1 and amelogenin, respectively, and augmented the differentiation media-induced mineralization, which was confirmed by alizarin red s and alkaline phosphatase staining. These results suggest that IGFBP5-7 may play independent and redundant regulatory roles in late-stage odontogenesis by modulating the functional differentiation of ameloblasts and odontoblasts.

Direct reprogramming of fibroblasts into diverse lineage cells by DNA demethylation followed by differentiating cultures.

Direct reprogramming, also known as a trans-differentiation, is a technique to allow mature cells to be converted into other types of cells without inducing a pluripotent stage. It has been suggested as a major strategy to acquire the desired type of cells in cell-based therapies to repair damaged tissues. Studies related to switching the fate of cells through epigenetic modification have been progressing and they can bypass safety issues raised by the virus-based transfection methods. In this study, a protocol was established to directly convert fully differentiated fibroblasts into diverse mesenchymal-lineage cells, such as osteoblasts, adipocytes, chondrocytes, and ectodermal cells, including neurons, by means of DNA demethylation, immediately followed by culturing in various differentiating media. First, 24 h exposure of 5-azacytidine (5-aza-CN), a well-characterized DNA methyl transferase inhibitor, to NIH-3T3 murine fibroblast cells induced the expression of stem-cell markers, that is, increasing cell plasticity. Next, 5-aza-CN treated fibroblasts were cultured in osteogenic, adipogenic, chondrogenic, and neurogenic media with or without bone morphogenetic protein 2 for a designated period. Differentiation of each desired type of cell was verified by quantitative reverse transcriptase-polymerase chain reaction/ western blot assays for appropriate marker expression and by various staining methods, such as alkaline phosphatase/alizarin red S/oil red O/alcian blue. These proposed procedures allowed easier acquisition of the desired cells without any transgenic modification, using direct reprogramming technology, and thus may help make it more available in the clinical fields of regenerative medicine.

The health-related quality-of-life of chronic obstructive pulmonary disease patients and disease-related indirect burdens.

BACKGROUND/AIMS: Many chronic obstructive pulmonary disease (COPD) patients have physical limitations. We investigated EuroQol five-dimensions five-level (EQ-5D-5L) of COPD patients to assess quality of life, and assessed indirect burden including time expenditure to visit doctor, home care rate, and caregiver related burden. METHODS: We recruited 355 COPD patients according to severity of airflow limitation that severity was set at 10% mild, 40% moderate, 30% severe, and 20% very severe in two primary and 11 secondary/tertiary hospitals. Eligible patients were aged ≥ 40 years, who have been diagnosed with COPD for more than 1 year. Patients were recruited between June 2015 and October 2016. RESULTS: The quality of life tended to decline with age, from mild to very severe impairment, as revealed by the EQ-5D-5L scores and the EQ visual analog scale. Family caregivers accompanied 22.6% of patients who visited outpatient clinics, and 25% of stage IV COPD patients. During emergency visits and hospitalization, this figure increased to > 60%. The home care rates were 28.5% for stage I patients, and 34.4, 31.8, and 52% for stage II to IV patients, respectively. The percentage of caregivers who stopped working was 13.6%. The EQ-5D index was strongly associated with the dyspnea scale (r = -0.64, p < 0.001). The average required time to see a doctor and visit the pharmacy was 154 minutes. CONCLUSION: In patients with COPD, the EQ-5D index decreased and disease-related home caregiving increased with airflow limitation. We considered the caregiver- related burden when making a strategy for COPD management.

Synergistic alveolar bone resorption by diabetic advanced glycation end products and mechanical forces.

BACKGROUND: The association between diabetes mellitus (DM) and bone diseases is acknowledged. However, the mechanistic pathways leading to the alveolar bone (AB) destruction remain unclear. This study aims to elucidate the mechanical forces (MF)-induced AB destruction in DM and its underlying mechanism. METHODS: In vivo periodontal tissue responses to MF were evaluated in rats with diabetes. In vitro human periodontal ligament (PDL) cells were either treated with advanced glycation end products (AGEs) alone or with AGEs and MF. RESULTS: In vivo, the transcription of VEGF-A, colony stimulating factor-1 (CSF-1), and Ager was upregulated in diabetes, whereas changes in DDOST and Glo1 mRNAs were negligible. DM induced VEGF-A protein in the vascular cells of the PDL and subsequent angiogenesis, but DM itself did not induce osteoclastogenesis. MF-induced AB resorption was augmented in DM, and such augmentation was morphologically substantiated by the occasional undermining resorption as well as the frontal resorption of the AB by osteoclasts. The mRNA levels of CSF-1 and vascular endothelial growth factor (VEGF) during MF application were highly elevated in diabetes, compared with those of the normal counterparts. In vitro, AGEs treatment elevated Glut-1 and CSF-1 mRNA levels via the p38 and JNK pathways, whereas OGT and VEGF levels remained unchanged. Compressive MF especially caused upregulation of VEGF, CSF-1, and Glut-1 levels, and such upregulation was further enhanced by AGEs treatment. CONCLUSIONS: Overloaded MF and AGEs metabolites may synergistically aggravate AB destruction by upregulating CSF-1 and VEGF. Therefore, regulating the compressive overloading of teeth, as well as the levels of diabetic AGEs, may prove to be an effective therapeutic modality for managing DM-induced AB destruction.

Direct and Indirect Costs of Chronic Obstructive Pulmonary Disease in Korea.

BACKGROUND: Understanding the burden of disease is important to establish cost-effective treatment strategies and to allocate healthcare resources appropriately. However, little reliable information is available regarding the overall economic burden imposed by chronic obstructive pulmonary disease (COPD) in Korea. METHODS: This study is a multicenter observational research on the COPD burden in Korea. Total COPD costs were comprised of three categories: direct medical, direct non-medical, and indirect costs. For direct medical costs, institutional investigation was performed at 13 medical facilities mainly based on the claims data. For direct non-medical and indirect costs, site-based surveys were administered to the COPD patients during routine visits. Total costs were estimated using the COPD population defined in the recent report. RESULTS: The estimated total costs were approximately 1,245 million US dollar (1,408 billion Korean won). Direct medical costs comprised approximately 20% of the total estimated costs. Of these, formal medical costs held more than 80%. As direct non-medical costs, nursing costs made up the largest percentage (39%) of the total estimated costs. Costs for COPD-related loss of productivity formed four fifths of indirect costs, and accounted for up to 33% of the total costs. CONCLUSION: This study shows for the first time the direct and indirect costs of COPD in Korea. The total costs were enormous, and the costs of nursing and lost productivity comprised approximately 70% of total costs. The results provide insight for an effective allocation of healthcare resources and to inform establishment of strategies to reduce national burden of COPD.

Evaluation of a technology-enhanced integrated care model for frail older persons: protocol of the SPEC study, a stepped-wedge cluster randomized trial in nursing homes.

BACKGROUND: Limited evidence exists on the effectiveness of the chronic care model for people with multimorbidity. This study aims to evaluate the effectiveness of an information and communication technology- (ICT-)enhanced integrated care model, called Systems for Person-centered Elder Care (SPEC), for frail older adults at nursing homes. METHODS/DESIGN: SPEC is a prospective stepped-wedge cluster randomized trial conducted at 10 nursing homes in South Korea. Residents aged 65 or older meeting the inclusion/exclusion criteria in all the homes are eligible to participate. The multifaceted SPEC intervention, a geriatric care model guided by the chronic care model, consists of five components: comprehensive geriatric assessment for need/risk profiling, individual need-based care planning, interdisciplinary case conferences, person-centered care coordination, and a cloud-based information and communications technology (ICT) tool supporting the intervention process. The primary outcome is quality of care for older residents using a composite measure of quality indicators from the interRAI LTCF assessment system. Outcome assessors and data analysts will be blinded to group assignment. Secondary outcomes include quality of life, healthcare utilization, and cost. Process evaluation will be also conducted. DISCUSSION: This study is expected to provide important new evidence on the effectiveness, cost-effectiveness, and implementation process of an ICT-supported chronic care model for older persons with multiple chronic illnesses. The SPEC intervention is also unique as the first registered trial implementing an integrated care model using technology to promote person-centered care for frail older nursing home residents in South Korea, where formal LTC was recently introduced. TRIAL REGISTRATION: ISRCTN11972147.

Morphological analysis of the occlusal surface of maxillary molars in Koreans.

OBJECTIVE: To determine the diameter of the crown, total crown area, individual cusp area, and occlusal table area in Korean maxillary permanent molars, as well as dental characteristics relevant to the hypocone reduction trait. MATERIALS AND METHODS: Subjects included 121 dental school students in Korea (81 men and 40 women). A digital image analysis system was used for measurements and we relied on visual scoring to assign categories of hypocone expression. RESULTS: The mean crown dimension was larger in the first molar (M1) than in the second molar (M2). Regarding differences according to gender, the crown diameter, total crown area, and individual cusp area were significantly larger in the men than in the women. The mean occlusal table area ratios were 61% for M1 and 57% for M2, and these ratios increased in proportion to the total crown area. With respect to the hypocone and other features of the maxillary molars, differences between the men and women were more prominent for M1 than for M2. The M2 hypocone tended to be smaller than the M1 hypocone, and hypocone reduction was inversely related to the cusp area of the protocone. The protocone area may be considered a reliable parameter for comparing race and/or gender differences in maxillary molars. CONCLUSION: This study concerning characteristics of the maxillary molar occlusal surface in Koreans provides useful information for comparative studies among human races.