PURPOSE: Many studies have proposed predictive models for type 2 diabetes mellitus (T2DM). However, these predictive models have several limitations, such as user convenience and reproducibility. The purpose of this study was to develop a T2DM predictive model using electronic medical records (EMRs) and machine learning and to compare the performance of this model with traditional statistical methods. MATERIALS AND METHODS: In this study, a total of available 8454 patients who had no history of diabetes and were treated at the cardiovascular center of Korea University Guro Hospital were enrolled. All subjects completed 5 years of follow up. The prevalence of T2DM during follow up was 4.78% (404/8454). A total of 28 variables were extracted from the EMRs. In order to verify the cross-validation test according to the prediction model, logistic regression (LR), linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), and K-nearest neighbor (KNN) algorithm models were generated. The LR model was considered as the existing statistical analysis method. RESULTS: All predictive models maintained a change within the standard deviation of area under the curve (AUC) < 0.01 in the analysis after a 10-fold cross-validation test. Among all predictive models, the LR learning model showed the highest prediction performance, with an AUC of 0.78. However, compared to the LR model, the LDA, QDA, and KNN models did not show a statistically significant difference. CONCLUSION: We successfully developed and verified a T2DM prediction system using machine learning and an EMR database, and it predicted the 5-year occurrence of T2DM similarly to with a traditional prediction model. In further study, it is necessary to apply and verify the prediction model through clinical research.
Area Under Curve ; Diabetes Mellitus ; Diabetes Mellitus, Type 2 ; Electronic Health Records ; Follow-Up Studies ; Humans ; Korea ; Learning ; Logistic Models ; Machine Learning ; Methods ; Prevalence

Neuropathic pain is a chronic pain disorder caused by nervous system lesions as a direct consequence of a lesion or by disease of the portions of the nervous system that normally signal pain. The spinal nerve ligation (SNL) model in rats that reflect some components of clinical pain have played a crucial role in the understanding of neuropathic pain. To investigate the direct effects of gabapentin on differential gene expression in cultured dorsal root ganglion (DRG) cells of SNL model rats, we performed a differential display reverse transcription-polymerase chain reaction analysis with random priming approach using annealing control primer. Genes encoding metallothionein 1a, transforming growth factor-beta1 and palmitoyl-protein thioesterase-2 were up-regulated in gabapentin-treated DRG cells of SNL model rats. The functional roles of these differentially expressed genes were previously suggested as neuroprotective genes. Further study of these genes is expected to reveal potential targets of gabapentin.
Animals ; Chronic Pain ; Diagnosis-Related Groups ; Ganglia, Spinal* ; Gene Expression ; Ligation ; Metallothionein ; Nervous System ; Neuralgia* ; Rats* ; Spinal Nerve Roots* ; Spinal Nerves

BACKGROUND: ABO genotyping is commonly used in cases of an ABO discrepancy between cell typing and serum typing, as well as in forensic practice for personal identification and paternity testing. We evaluated ABO genotyping via multiplex allele-specific PCR (ASPCR) amplification using whole blood samples without DNA purification. METHODS: A four-reaction multiplex ASPCR genotyping assay was designed to detect specific nucleotide sequence differences between the six ABO alleles A101, A102, B101, O01, O02, and cis-AB01. The ABO genotypes of 127 randomly chosen samples were determined using the new multiplex ASPCR method. RESULTS: The genotypes of the 127 samples were found to be A101/A102 (n=1), A102/A102 (n=9), A101/O01 (n=3), A102/O01 (n=12), A102/O02 (n=14), B101/B101 (n=5), B101/O01 (n=18), B101/O02 (n=15), O01/O01 (n=14), O02/O02 (n=8), O01/O02 (n=14) and A102/B101 (n=14), from which phenotypes were calculated to be A (n=39), B (n=38), O (n=36) and AB (n=14). The multiplex ASPCR assay results were compared with the serologically determined blood group phenotypes and genotypes determined by DNA sequencing, and there were no discrepancies. CONCLUSIONS: This convenient multiplex ASPCR assay, performed using whole blood samples, provides a supplement to routine serological ABO typing and might also be useful in other genotyping applications.
ABO Blood-Group System/*genetics ; *Alleles ; DNA/blood ; Genotype ; Humans ; Polymerase Chain Reaction/*methods

PURPOSE: There is increasing consideration about the preemptive transplantation, transplantation without any preceding dialysis, as a one of options of a renal replacement therapy (RRT). This study evaluates a beneficial effect on recipient and allograft survival of preemptive transplantation and compares the outcome to that according to the dialysis modality and duration. METHODS: All patient who had received a kidney transplant from a living donor in the Seoul National University Hospital (SNUH) between January 1990 and October 2004 are included in this retrospective study. Patients were subdivided into three groups; preemptive transplant group (group 1, n=47), hemodialysis group (group 2, n=307) and peritoneal dialysis group (group 3, n=52). RESULTS: The characteristics of each groups were not statistically different except recipient age. Ten-year patient survival was 97.8% in PE group, but is not significantly higher than in HD (89.4%) and in PD (90.7%) groups. However, 10-year graft survival was higher in PE group than in HD group (p<0.05; 100%, 74.7% respectively). The differential effect of pretransplant dialysis duration on graft survival was prominent if the patients had been on the pretransplant dialysis for more than 42 months (p<0.05; 10-year graft survival; PE, 100% and dialysis more than 42 months, 77.9% respectively) Compared with HD group as a pre-transplant dialysis modality, PD group showed better patient and graft survival rate, but not statistically significant. CONCLUSION: Depending on the above results, we may suggest PE or PD being a superior pre-transplant modality than HD. And we should be considerate of choosing treatment modality and duration before transplantation.
Allografts ; Dialysis* ; Graft Survival* ; Humans ; Kidney Transplantation* ; Kidney* ; Living Donors* ; Peritoneal Dialysis ; Renal Dialysis ; Renal Replacement Therapy ; Retrospective Studies ; Seoul ; Transplants*

BACKGROUND: Darbepoetin alfa is a new erythropoietic agent with a three fold longer terminal half-life than recombinant human erythropoietin (r- HuEPO). The aim of this randomized, open-label study is to determine whether darbepoetin alfa is as effective as r-HuEPO for the treatment of anemia in hemodialysis patients when administered at a reduced dosing frequency. METHODS: A total 74 Korean hemodialysis patients receiving r-HuEPO therapy by either the intravenous (IV) or subcutaneous (SC) route were randomized to continue r-HuEPO or to receive an equivalent dose of darbepoetin alfa at a reduced dosing frequency. Patients receiving r-HuEPO once weekly changed to once every other week darbepoetin alfa, and those receiving r-HuEPO two or three times weekly changed to once-weekly darbepoetin alfa. The initial dose of darbepoetin alfa was based on the r-HuEPO dose at the time of entry into the study, using a formula equating the peptide mass of the two molecules (200 IU r-HuEPO=1 microgram darbepoetin alfa). The doses of r-HuEPO and darbepoetin alfa were titrated to maintain hemoglobin concentrations within -1.0 to +1.5 g/dL of patients' baseline values and within a range of 8.0 to 13.0 g/ dL for up to 20 weeks (16-week dose-titration period followed by a 4-week evaluation period). The primary end point was change in hemoglobin level between baseline and the evaluation period. RESULTS: The mean change in hemoglobin from baseline to the evaluation period was similar in the darbepoetin alfa (-0.03+/-0.19 g/dL) and r-HuEPO (0.27+/-0.20 g/dL) groups, and the difference between the two treatments was -0.30 g/dL (95% CI, -0.84 to 0.23). This was not a statistically significant or clinically relevant difference, despite the reduced frequency of darbepoetin alfa administration. The safety profiles of darbepoetin alfa and r-HuEPO were similar. CONCLUSION: This study suggests that darbepoetin alfa maintains hemoglobin as effectively as r- HuEPO, but with reduced dose frequency.
Anemia* ; Erythropoietin ; Half-Life ; Hemoglobin A ; Humans ; Renal Dialysis* ; Darbepoetin alfa

BACKGROUND: Diagnosis of RTA (renal tubular acidosis) is not easy due to its nonspecific and various manifestations. To find out the clues to diagnosis, we investigated initial manifestations, laboratory features and clinical course of RTA patients. METHODS: Thirty-seven patients with RTA type I or II, whose follow-up period was over 6 months were included in the study. We reviewed their medical records retrospectively. RESULTS: Male to female ratio was 5:32 and the average age at the time of diagnosis was 38.7 (15~60). Twenty-five patients had RTA type I, nine had type II, and three had both. The average follow-up period was 6.4 years. Initial manifestations were asthenia (54%), nausea (46%), urinary stone (24%), paresthesia (24%), lower extremity weakness (22%), and paralysis (11%). Underlying diseases at the time of diagnosis include Sjogren's syndrome (14%), SLE (8%), drug-induced nephropathy (11%), diabetic nephropathy (5.4%), Sjogren's syndrome combined with SLE (2.7%), and medullary sponge kidney (2.7%). Laboratory tests revealed acidosis with hypokalemia (59%), acidosis without hypokalemia (14%), and hypokalemia without acidosis (24%). The level of total CO2 was 22 mmol/L or lower in 27 patients. The Na:Cl ratio on the average was 1:1.26 and for 33 patients below 1:1.35. Renal function deteriorated in 8 patients and 7 of them had underlying diseases. Urinary stone developed in 2 patients with RTA type I. CONCLUSION: When patients with nonspecific symptoms show decreased levels of serum total CO2, potassium, or Na:Cl ratio, RTA should always be considered.
Acidosis ; Acidosis, Renal Tubular* ; Asthenia ; Diabetic Nephropathies ; Diagnosis ; Female ; Follow-Up Studies ; Humans ; Hypokalemia ; Lower Extremity ; Male ; Medical Records ; Medullary Sponge Kidney ; Nausea ; Paralysis ; Paresthesia ; Potassium ; Retrospective Studies ; Sjogren's Syndrome ; Urinary Calculi

BACKGROUND: The antidiuretic action of oxytocin in human has been controversial. To investigate whether oxytocin directly acts on water balance in human, we evaluated the parameters of urinary concentration in response to administration of oxytocin in ten healthy male volunteers. METHODS: Oxytocin was infused intravenously at a rate of 20 mU/hour for 2.5 hours and urine was collected during the last 2 hours of oxytocin infusion. Changes in urine volume, urine osmolality, excretions of urine electrolytes and free water clearance after the administrartion of oxytocin were compared with the baseline data. RESULTS: The changes in the levels of serum electrolytes and osmolality after the administration of oxytocin were not significant compared with the baseline data. The volume of 2 hours' urine were 446+/-75 mL and 289+/-53 mL in the basal state and after the administration of oxytocin, respectively. The urine osmolality was increased significantly by the infusion of oxytocin(427+/-63 mOsm/kg) compared with that in the basal state(223+/-25 mOsm/kg)(p < 0.05). The free water clearance was 110+/-51 mL/2 hours in the basal state and decreased significantly to -57+/-51 mL/2 hours(p < 0.05). CONCLUSION: We conclude that administration of oxytocin to normal men enhances urinary concentration, evidenced by increased urinary osmolality and decreased free water clearance. In human, oxytocin may play an important role in the regulation of renal water excretion as an antidiuretic hormone.
Electrolytes ; Humans ; Male ; Osmolar Concentration ; Oxytocin* ; Volunteers ; Water

This paper presents the design and application of a clinical data warehouse. The clinical data warehouse is built based on past 10 years of clinical data of Seoul National University Hospital. We extracted the clinical data from the database of hospital information system database and the results of Health 21 Project' , which is mainly composed of chief complaints, final diagnosis, discharge notes and survival data. By normalizing the terms of chief complaint, we are able to analyze the distribution patterns of symptoms within a diagnosis, and that of diagnosis related with a certain clinical symptom. Through our involvement with this project, we have learned that in order for a useful clinical data warehouse system, normalization and structured data entry is the key element of building clinical data warehouse.
Diagnosis ; Hospital Information Systems ; Seoul

Recently, it becomes conspicuous that the network should have enough communication bandwidth and be organized with steadiness to operate and support hospital information system successfully. Seoul National University Hospital completed to reconstruct legacy network which had been used since 1995. We had a consultation to diagnose the current problems and reconstructed the network according to the consultation. The design of network architecture was mainly focused on the circuit route in case of error condition and the suitable bandwidth for the easy communication. We also regulated the use of unsuitable protocols which might broadcast inappropriate data packets over the whole network. After 6 months of operation we evaluated the performance of newly constructed network. The average traffic rate from the input port of main servers was 0.5% and that from the output port was 6% separately. The average traffic rate on the overall ATM backbone showed around 1 %.From the result, we concluded that the newly constructed network had such an enough capability supporting hospital information system without any interruption. Furthermore, we expect that it will be sufficient to support the additional traffic increment by PACS and group ware applications.
Hospital Information Systems ; Hospitals, General* ; Information Services* ; Information Systems* ; Seoul*

Mineralocorticoids influences on acid-base homeostasis by the regulation of urine acidification. But its mechanism of acion is not well known in human. This study compared the acid-base status and the indices of urine acidification before and after mineralocorticoid administration in human, and analyzed the effect of mineralocorticoids on human acid-base homeostasis. We administered 9a-fludrocortisone in 6 chronic renal failure patients and 6 normal controls 0.5mg daily for 7 days. The results were as following: 1) After administration of 9a-fludrocortisone in patients group, serum aldosterone level changed from 120.2+/-71.0pg/mL to 44.8+/-32.2pg/mL(mean+/-SD, p< 0.05). Serum HCO- level was not changed. Urine ammonium excretion was incresed from 24.6+/-12.3 mmol/day to 43.7+/-19.0 (p<0.05), but there were no change in urine pH and urine anion gap, Serum potassium level decreased from 5.5+/-0.7mBq/L to 4.1+/-0.5mEq/L (p<0.05), and TTKG increased from 3.9 to 8.9(p<0.05). 2) After administration of 9a-fludrocortisone in control group, serum aldosterone level changed from 99.7+/-44.5pg/mL to 25.1+/-3 mL(p<0.05). Serum HCO- level was not changed. Urine ammonium excretion was incresed from 44.3+/-21.6mmoVday to 76.3+/-19.6(p<0.05), but there were no change in urine pH and urine anion gap. Serum potassium level decreased from 4.8+/-0.5mEq/L to 3.9+/-0.2mHq/L(p< 0.05), but there was no change in TTKG. 3) No patient or control showed any discomfort after 9-fludrocortisone administration, and there was no elevation in diastolic blood pressure, increase in body weight, electrolyte abnormality. In summary, after 9alpha-fludrocortisane administration, urinary ammonium excretion increased in both patients and control group, and this phenomenon occured with correction of hyperkalemia without urine pH change. This result implies urinary ammonium excretion increase by mineralocorticoid. In human increase in renal distal acidification by mineralocorticoid is due to increase in renal ammoniagenesis rather than stimulation on proton excretion.
Acid-Base Equilibrium ; Aldosterone ; Ammonium Compounds* ; Blood Pressure ; Body Weight ; Homeostasis ; Humans ; Hydrogen-Ion Concentration ; Hyperkalemia ; Kidney Failure, Chronic ; Mineralocorticoids ; Potassium* ; Protons