Objective: To develop a deep-learning-based bone age prediction model optimized for Korean children and adolescents and evaluate its feasibility by comparing it with a Greulich-Pyle-based deep-learning model. Materials and Methods: A convolutional neural network was trained to predict age according to the bone development shown on a hand radiograph (bone age) using 21036 hand radiographs of Korean children and adolescents without known bone development-affecting diseases/conditions obtained between 1998 and 2019 (median age [interquartile range {IQR}], 9 [7–12] years; male:female, 11794:9242) and their chronological ages as labels (Korean model). We constructed 2 separate external datasets consisting of Korean children and adolescents with healthy bone development (Institution 1: n = 343;median age [IQR], 10 [4–15] years; male: female, 183:160; Institution 2: n = 321; median age [IQR], 9 [5–14] years; male:female, 164:157) to test the model performance. The mean absolute error (MAE), root mean square error (RMSE), and proportions of bone age predictions within 6, 12, 18, and 24 months of the reference age (chronological age) were compared between the Korean model and a commercial model (VUNO Med-BoneAge version 1.1; VUNO) trained with Greulich-Pyle-based age as the label (GP-based model). Results: Compared with the GP-based model, the Korean model showed a lower RMSE (11.2 vs. 13.8 months; P = 0.004) and MAE (8.2 vs. 10.5 months; P = 0.002), a higher proportion of bone age predictions within 18 months of chronological age (88.3% vs. 82.2%; P = 0.031) for Institution 1, and a lower MAE (9.5 vs. 11.0 months; P = 0.022) and higher proportion of bone age predictions within 6 months (44.5% vs. 36.4%; P = 0.044) for Institution 2. Conclusion The Korean model trained using the chronological ages of Korean children and adolescents without known bone development-affecting diseases/conditions as labels performed better in bone age assessment than the GP-based model in the Korean pediatric population. Further validation is required to confirm its accuracy.

BACKGROUND: Chromosomal abnormalities are confirmed as one of the frequent causes of male infertility. The microdeletion of the azoospermia factor (AZF) region in the Y chromosome was discovered as another frequent genetic cause associated with male infertility. The aim of this study was to evaluate the frequency and type of chromosomal abnormalities and Y chromosome microdeletions in Korean infertile men. METHODS: A total of 846 infertile men with azoospermia and severe oligozoospermia were included for genetic screening. Cytogenetic analyses using G-banding and screening for Y chromosome microdeletions by multiplex PCR for AZF genes were performed. RESULTS: Chromosomal abnormalities were detected in 112 infertile men (13.2%). Of these, Klinefelter's syndrome was the most common (55.4%, 62/112), followed by balanced translocation including translocation between sex chromosome and autosome (14.3%), Yq deletion (13.4%), X/XY mosaicism with Yq deletion (12.5%), and XX male (4.5%). The overall prevalence of Y chromosome microdeletions was 9.2% (78/846). Most microdeletions were in the AZFc region (51.3%) with a low incidence in AZFa (7.7 %) and AZFb (6.4 %). Combined deletions involving the AZFbc and AZFabc regions were detected in 26.9 % and 7.7 % of men, respectively. Among the infertile men with Y chromosome microdeletions, the incidence of chromosomal abnormality was 25.6% (20/78). CONCLUSIONS: There was a high incidence (20.1%) of chromosomal abnormalities and Y chromosome microdeletions in Korean infertile men. These findings strongly suggest that genetic screening for chromosomal abnormalities and Y chromosome microdeletions should be performed, and genetic counseling should be provided before starting assisted reproductive techniques.
Azoospermia ; Chromosome Aberrations* ; Cytogenetic Analysis ; Genetic Counseling ; Genetic Testing* ; Humans ; Incidence ; Infertility, Male ; Klinefelter Syndrome ; Male ; Mass Screening ; Mosaicism ; Multiplex Polymerase Chain Reaction ; Oligospermia ; Prevalence ; Reproductive Techniques, Assisted ; Sex Chromosomes ; Y Chromosome*

Vasospasm has been known as one of the most potent causes of delayed ischemic neurologic deficits (DINDs) after aneurysmal subarachnoid hemorrhage (SAH). An established effective therapy for vasospasm has been used in preventing cerebral ischemia. Nevertheless, several reports suggested the possibility that there may be other causes of DINDs from the cases which couldn't be explained by hemodynamic vasospasm. Authors experienced two cases of thromboembolic infarction as a cause of DINDs after aneurysmal SAH. We propose that thromboembolism can be a considerable cause of DINDs independent of hemodynamic vasospasm.
Aneurysm ; Brain Ischemia ; Hemodynamics ; Infarction ; Neurologic Manifestations ; Subarachnoid Hemorrhage ; Thromboembolism

OBJECTIVE: Acute cerebral infarction is often accompanied by transtentorial herniation which can be fatal. The aim of this study is to determine the timing of surgical intervention and prognostic factors in patients who present with acute cerebral infarction. METHODS: We reviewed retrospectively 23 patients with acute cerebral infarction, who received decompressive craniectomy or conservative treatment from January 2002 to December 2004. We divided patients into two groups according to the treatment modalities (Group 1: conservative treatment, Group 2: decompressive craniectomy). In all patients, the outcome was quantified with Glasgow Outcome Scale and Barthel Index. RESULTS: Of the 23 patients, 11 underwent decompressive craniectomy. With decompressive craniectomy at the time of loss of pupillary light reflex, we were able to prevent death secondary to severe brain edema in all cases. Preoperative Glasgow Coma Scale and loss of pupillary light reflex were significant to the clinical outcome statistically. With conservative treatment, 9 of the 12 patients died secondary to transtentorial herniation. The clinical outcomes of remaining 3 patients were poor. CONCLUSION: This study confirms the value of life-saving procedure of decompressive craniectomy after acute cerebral infarction. We propose that the loss of pupillary light reflex should be considered one of the most important factors to determine the timing of the decompressive craniectomy.
Brain Edema ; Cerebral Infarction* ; Decompressive Craniectomy* ; Glasgow Coma Scale ; Glasgow Outcome Scale ; Humans ; Reflex ; Retrospective Studies

OBJECTIVE: Neurosurgeons occasionally advocated intraoperative ventriculostomy to prevent traumatic brain retraction because of severe brain swelling in an acute stage of aneurysmal subarachnoid hemorrhage (SAH) surgery. The authors investigated the impact of the intraoperative ventriculostomy on the occurrence of shunt-dependent hydrocephalus in acute SAH. METHODS: The data of 141 ruptured aneurysm patients who underwent aneurysmal neck clipping in an acute stage were retrospectively reviewed. The patients were divided into three groups according to the cerebrospinal fluid (CSF) drainage amount via intraoperative ventriculostomy. Group 1 (n=44) included the patients who were not performed the intraoperative ventriculostomy, Group 2 (n=34) consisted of patients who were drained the CSF less than 40 cc (< 40 cc) via intraoperative ventriculostomy, and Group 3 (n=63) drained the CSF more than 40 cc (> or = 40 cc). By using statistical methods, the authors analyzed the influences of various variables including Hunt-Hess grade, Fisher grade, Glasgow coma scale, Glasgow outcome scale, presence of acute hydrocephalus and intraventricular hemorrhage (IVH) at admission on the occurrence of hydrocephalus. And also, we analyzed the relationships among the cisternal drainage, lamina terminalis fenestration, and the shunt-dependent hydrocephalus. RESULTS: Concerning the amount of CSF drainage via intraoperative ventriculostomy, the incidence of shunt-dependent hydrocephalus did not show any difference in three groups (p=0.146). Presence of the acute hydrocephalus, lamina terminalis fenestration, and cisternal drainage did not exert any influence on the incidence of shunt-dependent hydrocephalus, respectively (p=0.124, p=0.168, p=0.452). However, the incidence of shunt-dependent hydrocephalus in patients who had IVH at admission was significantly higher than in who did not have (p=0.010). CONCLUSIONS: Routine intraoperative ventriculostomy dose not increase the incidence of shunt-dependent hydrocephalus. Moreover, it obtains an adequate intraoperative brain relaxation, which results in the decrease of the brain retraction injury and the operation time.
Aneurysm* ; Aneurysm, Ruptured ; Brain ; Brain Edema ; Cerebrospinal Fluid ; Drainage ; Glasgow Coma Scale ; Glasgow Outcome Scale ; Hemorrhage ; Humans ; Hydrocephalus* ; Hypothalamus ; Incidence ; Neck ; Relaxation ; Retrospective Studies ; Subarachnoid Hemorrhage* ; Ventriculostomy*

PURPOSE: We recently experienced 3 consecutive cases of bile peritonitis due to tract rupture following T-tube removal at about 6 weeks after choledocholithotomy with using a new tube (1.1% silica-filled rubber). These unexpected cases of bile peritonitis have raised questions related to the tube material factor for the rupture. The aim of this study was to compare three kinds of T-tubes [ (100% silicone (SIL), 1.1% silica-filled rubber (SFR), and 100% rubber (RUB) ] from the point of view of fistula maturation as is related to the physicochemical properties of the tube materials. METHODS: SIL, SFR and RUB tubes were implanted into the subcutaneous space in rats. Histologically, the degree of fistula maturation was estimated by an inflammation score, the thickness of inflammation and the fibrosis. The physical properties of the tube materials were estimated by their modulus and elasticity. RESULTS: SFR and RUB tube had no statistically significant difference for the thickness of the inflammation and fibrosis. Yet there were difference in their modulus and elasticity. The modulus, elasticity, thickness of the inflammation and the fibrosis were difference in the SIL versus SFR and the SIL versus RUB. CONCLUSION: There were no statistically significant differences in the degree of fistula maturation between the SFR and RUB tubes. The rubber tube tended to show a more severe inflammatory reaction and better maturation of the fistula. Moreover, the flexibleness of the RUB tube make easy to experience collapse of the tube. The degree of maturation mostly depends upon the chemical property of the tube materials. However, the tract rupture that happens is due to the physical properties rather than the chemical properties of the tube. We recommend RUB for the T-tube to prevent the tube related complication such as tract rupture.
Animals ; Bile ; Choledochostomy ; Elasticity ; Fibrosis ; Fistula* ; Inflammation ; Latex ; Peritonitis ; Rats ; Rubber ; Rupture ; Silicones

In rare cases, early gastric cancer resembles the endoscopic features of a submucosal tumor (SMT). A correct histological diagnosis is difficult with repeated biopsy specimens because they are covered with normal mucosa. Some features known to suggest malignant SMT include a size greater than 3 to 5 cm, a rapid growth rate, echoheterogeneity and irregular margins on endoscopic ultrasonography (EUS). Various techniques including US-guided biopsy, partial removal by an endoscopic snare excision, as well as EUS with a fine needle aspiration were used to enhance the diagnostic accuracy. We recently experienced a case of early gastric cancer, presenting as a submucosal tumor-like lesion, which was confirmed by endoscopic mucosal resection. We report this case with a review of the relevant literature.
Adenocarcinoma* ; Biopsy ; Biopsy, Fine-Needle ; Diagnosis ; Endosonography ; Mucous Membrane ; SNARE Proteins ; Stomach Neoplasms

Backgrounds/Aims: This study aimed to estimate the seroepidemiology of hepatitis B virus (HBV) infection with emphasis on the transmission of HBV infection between mothers and their children. METHODS: For 452 patients with HBV associated chronic liver disease, and 1,098 of their offspring, who visited Korea University Kuro Hospital from February, 2000 to February, 2001, HBsAg was tested by radioimmunoassay. RESULTS: Among siblings whose mothers were HBsAg-positive, the overall prevalence rate of HBV infection was 44.9% (140/312) and decreased with decreasing age (54.7% in > or =20 years old age group, 33.3% in 10-19 years old age group, 7.6% in <10 years old age group). The estimated proportion of perinatal infection out of modes of HBV transmissions in the general population was 38% in <10 years and 63.4% in 10-19 years. CONCLUSION: The present hepatitis B vaccination strategies -especially against perinatal infection- of Korea have performed to their utmost. More effective methods for the prevention of HBV transmission are now needed.
Child ; Epidemiology ; Hepatitis B Surface Antigens ; Hepatitis B virus ; Hepatitis B* ; Hepatitis* ; Humans ; Korea ; Liver Diseases* ; Liver* ; Mothers ; Prevalence ; Radioimmunoassay ; Siblings* ; Vaccination

BACKGROUND: The dominant innervation of airway smooth muscle is parasympathetic fibers which are carried in the vagus nerve. Activation of these cholinergic nerves releases acetylcholine which binds to M3 muscarinic receptors on the smooth muscle causing bronchocontraction. Acetylcholine also feeds back onto neuronal M2 muscarinic receptors located on the postganglionic cholinergic nerves. Stimulation of these receptors further inhibits acetylcholine release, so these M2 muscarinic receptors act as autoreceptors. Loss of function of these M2 receptors, as it occres in animal models of hyperresponsiveness, leads to an increase in vagally mediated hyperresponsiveness. However, there are limited data pertaining to whether there are dysfunctions of these receptors in patients with asthma. The aim of this study is to determine whether there are dysfunction of M2 muscarinic receptors in asthmatic patients and difference of function of these receptors according to severity of asthma. METHODS: We studied twenty-seven patients with asthma who were registered at Pulmonology Division of Korea University Hospital. They all met asthma criteria of ATS. Of these patients, eleven patients were categorized as having mild asthma, eight patients moderate asthma and eight patients severe asthma according to severity by NAEPP Expert Panel Report 2(1997). All subjects were free of recent upper respiratory tract infection within 2 weeks and showed positive methacholine challenge test(PC 20<16mg/ml). Methacholine provocation tests performed twice on separate days allowing for an interval of one week. In the second test, pre-treatment with the M2 muscarinic receptor agonist pilocarpine(180µg) through inhalation was performed before the routine procedures. RESULTS: Eleven subjects with mild asthma and eight aubjects with moderate asthma showed significant increase of PC20 from 5.30±5.23mg/ml(mean±SD) to 20.82±22.56mg/ml(p=0.004) and from 2.79±1.5mg/ml to 4.67±3.53mg/ml(p=0.012) after pilocarpine inhalation, respectively. However, in the eight subjects with severe asthma significant increase of PC20 from 1.76±1.50mg/ml to 3.18±4.03mg/ml(p=0.161) after pilocarpine inhalation was not found. CONCLUSION: In subjects with mild and moderate asthma, function of M2 muscarinic receptors was normal, but there was a dysfunction of these receptors in subjects with severe asthma. These results suggest that function of M2 muscarinic receptors is different according to severity of asthma.
Acetylcholine ; Asthma ; Autoreceptors ; Humans ; Inhalation ; Korea ; Methacholine Chloride ; Models, Animal ; Muscle, Smooth ; Neurons* ; Pilocarpine ; Pulmonary Medicine ; Receptors, Muscarinic* ; Respiratory Tract Infections ; Vagus Nerve

No abstract available.
Alopecia* ; Tissue Expansion Devices*