Population pharmacokinetic analysis and modeling procedures typically require estimates of both population and individual pharmacokinetic parameters. However, only some of these parameters are contained in models and only parameters in the model can be estimated. In this paper, we introduce a new R package, PKconverter, to calculate pharmacokinetic parameters using the relationships among them. After fitting the model, other parameters can be calculated from the functional relationship among the parameters. PKconverter provides the functions to calculate whole parameters along with a Shiny application for converting the parameters. With this package, it is also possible to calculate the standard errors of the other parameters that are not in the model and estimate individual parameters simultaneously.
Drug Packaging ; Pharmaceutical Preparations ; Models, Biological ; Computer Simulation ; Software

OBJECTIVES: In establishing policies for agricultural safety, evaluating injury burdens as well as investigating the rates and characteristics of work injury is important. This study investigated the types and characteristics of agricultural injury subjective burdens. METHODS: By analyzing the injured farmers identified in the 2013 Korean Farmers' Occupational Injury Survey, the burdens caused by injuries were categorized using one direct cost item (medical costs) and five indirect cost items (including productivity decreases and wage increases). Statistical differences among the burden items were analyzed using logistic regression analysis according to the characteristics of the farmers and their farm injuries. RESULTS: Among the subjective burdens indicated by the 457 injured farmers, disruption to work was most common. The major influences on each subjective burden item are as follows: for the item of disruption to work, age, time of injury occurrence, treatment period, and farming machine use were influential; for an increased family member's burden of farm works, the number of family members and treatment period were influential. Regarding cost burden of treatment, the results varied according to whether or not the patient was hospitalized and annual income. CONCLUSION: Subjective burdens induced by indirect costs rather than those induced by direct costs were found to be higher in ratio. In regard to each burden item, the results varied according to the characteristics of the farmers and their farm injuries. To support injured farmer, setting goals to reduce indirect cost burdens and preparing concrete methods is necessary.
Efficiency ; Humans ; Logistic Models ; Occupational Injuries ; Salaries and Fringe Benefits

OBJECTIVE: Assessment of health-related quality of life in patients with rheumatoid arthritis (RA) has become important in health research. Health economists have used linear regression equations to mathematically transform changes in HAQ scores into EQ5D data, which can be used to calculate quality adjusted life years (QALYs). We aimed to examine whether a given approach is justified. METHODS: A total of 223 patients with RA were recruited from the Hospital for Rheumatic Diseases at Hanyang University. They completed the HAQ and EQ5D and a correlation analysis was performed between the two instruments. We compared HAQ and EQ5D score changes for patients who completed the EQ5D and HAQ at first and second visits (n=159). Predicted EQ5D was estimated from the HAQ using the calculating method of Bansnack et al. The mean difference between the predicted EQ5D from the HAQ and observed health utility score at the first visit and change during the study were tested by the paired t-test. RESULTS: In the cross-sectional study, EQ5D scores were moderately inversely correlated with HAQ (r=-0.716, p<0.001). However, the predicted EQ5D from the HAQ was significantly different from the observed EQ5D (p=0.001; 95% confidence interval [CI] 0.020~0.079). The change in EQ5D was also inversely correlated with the change in the HAQ (r=-0.615, p<0.001), and change in the predicted EQ5D scores corresponded well with changes in observed health utility scores (p=0.155; 95% CI (-0.0873~0.0140). CONCLUSION: Changes in predicted EQ5D corresponded with observer changes in EQ5D, suggesting that it may be better to use predicted EQ5D form HAQ to identify change in the quality of life.
Arthritis, Rheumatoid ; Cross-Sectional Studies ; Humans ; Linear Models ; Mitoxantrone ; Quality of Life ; Quality-Adjusted Life Years ; Surveys and Questionnaires ; Rheumatic Diseases

OBJECTIVES: This study estimated the rate of agricultural injury using a nationwide survey and identified factors associated with these injuries. METHODS: The first Korean Farmers' Occupational Disease and Injury Survey (KFODIS) was conducted by the Rural Development Administration in 2009. Data from 9,630 adults were collected through a household survey about agricultural injuries suffered in 2008. We estimated the injury rates among those whose injury required an absence of more than 4 days. Logistic regression was performed to identify the relationship between the prevalence of agricultural injuries and the general characteristics of the study population. RESULTS: We estimated that 3.2% (+/-0.00) of Korean farmers suffered agricultural injuries that required an absence of more than 4 days. The injury rates among orchard farmers (5.4 +/- 0.00) were higher those of all non-orchard farmers. The odds ratio (OR) for agricultural injuries was significantly lower in females (OR: 0.45, 95% CI = 0.45-0.45) compared to males. However, the odds of injury among farmers aged 50-59 (OR: 1.53, 95% CI = 1.46-1.60), 60-69 (OR: 1.45, 95% CI = 1.39-1.51), and > or =70 (OR: 1.94, 95% CI = 1.86-2.02) were significantly higher compared to those younger than 50. In addition, the total number of years farmed, average number of months per year of farming, and average hours per day of farming were significantly associated with agricultural injuries. CONCLUSIONS: Agricultural injury rates in this study were higher than rates reported by the existing compensation insurance data. Males and older farmers were at a greater risk of agriculture injuries; therefore, the prevention and management of agricultural injuries in this population is required.
Adult ; Agriculture ; Compensation and Redress ; Family Characteristics ; Female ; Humans ; Insurance ; Logistic Models ; Male ; Occupational Diseases* ; Occupational Injuries ; Odds Ratio ; Prevalence ; Social Planning

OBJECTIVE: The aim of this study is to describe the general characteristics and potential susceptibility genes of a large cohort of Korean rheumatoid arthritis (RA) patients. METHODS: After giving consent, the patients were invited to undergo a structured interview and clinical examination that were performed by rheumatologists and a specially trained research nurse. When appropriate, the information obtained by interview was supplemented by information from the patient's medical record. We reviewed the genetic studies for the subjects in the Hanyang RA cohort to investigate the genetic characteristics of Korean RA patients. RESULTS: The mean age of the Hanyang RA cohort was 51.6+/-12.4 years, and 88.1% were women. The unemployment rate was 19.6%, and 52.2% of the patients had limitation of everyday life or their work life. The mean age at the time of disease onset was 41.0+/-12.9 years and the duration from disease onset to initiation of treatment was 23.6+/-57.1 months. The smoking rate of the Hanyang RA cohort was 16.8%, and 30.8% of the patients were exposed to passive smoking. Total joint arthroplastys were performed in 158 (10.3%) patients, and the most common operation site was the knee. On the review of the genetic studies for the Hanyang RA cohort, the representative susceptibility genes for the development of RA were HLA-DRB1, PADI4, STAT4 and TRAF1-C5. CONCLUSION: This data of Korean RA patients can be used as the preliminary data for important studies. Establishment of a large prospective, multicenter cohort is imperative to determine the characteristics of Korean RA, and the Hanyang RA cohort is expected to play a lead role for this.
Arthritis, Rheumatoid ; Cohort Studies ; Female ; HLA-DRB1 Chains ; Humans ; Joints ; Knee ; Medical Records ; Smoke ; Smoking ; Tobacco Smoke Pollution ; Unemployment

17α-hydroxylase deficiency is a rare cause of congenital adrenal hyperplasia and is characterized by primary amenorrhea, delayed puberty and hypertension. Although 17α-hydroxylase deficiency mimics mineralocorticoid-induced hypertension, impaired sexual development can aid in the differential diagnosis of this disease. A 32-year-old woman, who had a history of testicular feminization syndrome, presented with hypertension. Her aldosterone level was elevated whereas plasma renin activity was reduced, and her computed tomography scan showed a left adrenal adenoma, which was thought to be an aldosterone producing adenoma. A left adrenalectomy was performed to treat hypertension; however, the condition did not improve. The hormonal tests revealed high levels of plasma progesterone, mineralocorticoid and adrenocorticotropic hormone, and low levels of 17a hydroxyprogesterone, cortisol and sex hormones. The patient was diagnosed with 17α-hydroxylase deficiency and commenced on prednisolone, which controlled hypertension. Here, we report a case of 17α-hydroxylase deficiency mimicking hyperaldosteronism via aldosterone-producing adrenal adenoma.
Adenoma* ; Adrenal Hyperplasia, Congenital ; Adrenalectomy ; Adrenocortical Adenoma ; Adrenocorticotropic Hormone ; Adult ; Aldosterone ; Amenorrhea ; Androgen-Insensitivity Syndrome ; Diagnosis, Differential ; Female ; Gonadal Steroid Hormones ; Humans ; Hydrocortisone ; Hyperaldosteronism* ; Hypertension ; Male ; Plasma ; Prednisolone ; Progesterone ; Puberty, Delayed ; Renin ; Sexual Development

Tooth wear is gradually increasing with increasing life expectancy. In particular, it is important to establish a treatment plan in the early stages so that it does not proceed to moderate or severe wear stages. It is essential to diagnose tooth wear accurately in order to plan a treatment for it. There are many risk factors including age, diet, and drugs which affects tooth wear. For the diagnosis of a tooth wear, appropriate index and evaluation method should be used. There were various tooth wear indices such as TWI, Lussi index, BEWE, and TWES. The evaluation method includes clinical examination, dental cast examination and clinical photographs. Recently, a 3D scanner is being used to assess tooth wear. The risk factors, tooth wear evaluation system, the methods of measuring tooth wear, and related literature were reviewed. The strengths and weaknesses of each index and evaluation methods were compared to derive a proper way to diagnose tooth wear.
Diagnosis ; Diet ; Life Expectancy ; Methods ; Risk Factors ; Tooth Wear ; Tooth

PURPOSE: Malignant central nervous system (CNS) germ cell tumors (GCTs), although rare, are thought to occur more frequently among Asians. However, a recent population-based study revealed no differences in GCT incidence between Asians and Caucasians. Therefore, this study was conducted to determine the incidence and survival rates of CNS GCTs using the national cancer incidence database, and to compare these rates to those in the United States and Japan. MATERIALS AND METHODS: We extracted CNS GCT patients diagnosed between 2005 and 2012 from the Korea Central Cancer Registry database. Age-standardized rates (ASRs), annual percentage change, and the male-female incidence rate ratios (IRRs) were calculated. To estimate the survival rate, we used data for patients diagnosed between 2005 and 2010 and followed their cases until December 31, 2013. RESULTS: The ASR for CNS GCT between 2005 and 2012 was 0.179 per 100,000 (95% confidence interval, 0.166 to 0.193), with an overall male-to-female (M:F) IRR of 2.95:1. However, when stratified by site, the M:F IRR was 13.62:1 for tumors of the pineal region and 1.87:1 for those located in nonpineal regions. The most frequent histologic type was germinoma (76.0%), and the most frequent location was the suprasellar region (48.5%). The 5-year survival rate of germinoma patients was 95.3%. CONCLUSION: The incidence rate of CNS GCTs in Korea during 2005-2012 was 0.179 per 100,000, which was similar to that of the Asian/Pacific Islander subpopulation in the United States. Moreover, the CNS GCT survival rate in Korea was similar to rates in Japan and the United States.
Asian Continental Ancestry Group ; Central Nervous System* ; Germ Cells* ; Germinoma ; Humans ; Incidence* ; Japan ; Korea* ; Neoplasms, Germ Cell and Embryonal* ; Survival Rate* ; United States

Infantile cortical hyperostosis, or Caffey's disease, usually presents with typical radiological features of soft tissue swelling and cortical thickening of the underlying bone. The disease can be fatal when it presents antenatally, especially before a gestational age of 35 weeks. This fatal, premature form of the disease is known to occur in various ethnic groups around the globe, and approximately 30 cases have been reported in English literature. This paper is unique in that it is the first paper to report a lethal form of prenatal-type infantile cortical hyperostosis diagnosed in South Korea. Born at gestational age of 27 weeks and 4 days, the patient had typical features of polyhydramnios, anasarca, hyperostosis of multiple bones, micrognathia, pulmonary hypoplasia, and hepatomegaly. The patient was hypotonic, and due to pulmonary hypoplasia and persistent pulmonary hypertension, had to be supported with high frequency ventilation throughout the entire hospital course. Due to the disease entity itself, as well as prolonged parenteral nutrition, liver failure progressed, and the patient expired on day 38 when uncontrolled septic shock was superimposed. The chromosome karyotype of the patient was normal, 46, XX, and COL1A1 gene mutation was not detected.
Edema ; Ethnic Groups ; Gestational Age ; Hepatomegaly ; High-Frequency Ventilation ; Humans ; Hyperostosis ; Hyperostosis, Cortical, Congenital ; Hypertension, Pulmonary ; Infant, Newborn ; Infant, Premature ; Karyotype ; Korea ; Liver Failure ; Micrognathism ; Parenteral Nutrition ; Polyhydramnios ; Shock, Septic

Remote cerebellar hemorrhage (RCH) is a rare complication of neurosurgical procedures and is characterized by a typical bleeding pattern defined as the “zebra sign.” Only few cases of RCH have been reported in the English literature, and its pathophysiology remains unclear. In this report, we present the cases of three patients with RCH after three different procedures: burr-hole trephination and chronic subdural hematoma evacuation of bilateral cerebral convexity with subsequent subdural drain insertion, lumbar drainage for cerebrospinal fluid divergence for thoracic endovascular aortic repair, and combined bypass surgery for moyamoya disease.