• Development and Reproduction
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• v.12 no.1
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• pp.1-8
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• 2008

Specific protocols to increase the differentiation of neuronal cells from embryonic stem (ES) cells have been well established, such as retinoic acid induction and lineage selection of neuronal cells. For the neuropathological studies, ES-derived neurons (ES neurons) must show normal physiological characteristics related to cell death and survival and should be maintained in vitro for a sufficient time to show insults-specific cell death without spontaneous death. When mouse ES cells were plated onto astrocytes monolayer after retinoic acid induction, most ES cells differentiated into neuronal cells, which were confirmed by the presence of specific neuronal markers, and the cultures were viable for at least four weeks. When these cultures were examined for vulnerability to glutamate excitotoxicity, ES neurons were vulnerable to excitotoxic insults mediated by agonist-specific receptors. The vulnerability to excitotoxic death increased with developmental age of ES neurons in vitro. Specific receptors for Neurotrophin and GDNF family ligands were present in ES neurons. GDNF and NT-3 could modulate the survival and excitotoxic vulnerability of ES neurons. The vulnerability and resistance to toxic insults, which are essential requirements of model culture systems for neuropathological studies, make ES neurons to a useful model culture system. Especially ES cell are highly amenable to genetic modification unlikely to primary neuronal cells, which will give us a chance to answer more complicated neurophysiological questions. Recently there was an outstanding attempt to explore the cellular toxicity using human ES cells (Schrattenholz & Klemm, 2007) and it suggested that ES cells could be a new model system for neurophysiological studies soon and go further a large-scale screening system for pharmacological compounds in the future.

• Clinical and Experimental Pediatrics
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• v.45 no.6
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• pp.754-763
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• 2002

Purpose : The incidence of type 2 diabetes in children and adolescents has been reported to increase recently. The aim of this study is to investigate the clinical features of type 2 diabetes developing during childhood and adolescent period. Methods : The medical records of 33 patients with type 2 diabetes were reviewed. We analysed clinical manifestations, demographic data, and modes and responses of treatment. Results : Age at diagnosis was $13.4{\pm}1.8$ years. Seventy percent of patients revealed pubertal signs at diagnosis. Half of the patients had BMI more than $25kg/m^2$. Seventy-three percent of patients had family history of type 2 diabetes. Acanthosis nigricans were found in 18% of patients. Nineteen(57.6%) patients were diagnosed incidentally by random urine or blood glucose test without any typical diabetic symptom or sign. The modes of therapy to control hyperglycemia were insulin alone(75.8%), oral hypoglycemic agents alone(9.1%), insulin and oral hypoglycemia agents(9.1%), and only diet with exercise(6%). At the time of investigation, 45.5% of patients were not using insulin. The typical diabetic symptoms at diagnosis were more prevalent in patients who required insulin for more than two years than patients who did not(P<0.05). Conclusion : The development of type 2 diabetes in children and adolescents is possibly related to puberty, obesity, family history, and defects in insulin secretion rather than insulin resistance. Many children and adolescents with type 2 diabetes required insulin initially and some of them could discontinue. More than half of the patients were diagnosed as diabetes without any typical symptom or sign, which might be one of the predictive factors of the prolonged insulin requirement.

• Clinical and Experimental Pediatrics
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• v.50 no.10
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• pp.987-994
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• 2007

Purpose : This study investigated the clinical significance of AN in children and adolescents with obesity induced metabolic complications. Methods : Forty-nine patients who had obesity induced metabolic complications were participated in this cross-sectional study. Obesity induced metabolic complications are as follows: hypertension, dyslipidemia, impaired fasting glucose (IFG), impaired glucose tolerance (IGT), nonalcoholic steatohepatitis (NASH), homeostasis model assessment of insulin resistance (HOMA-IR)>3.16. Clinical characteristics, such as, age, percentage-weight-for-height (PWH), pubertal status, blood pressure (BP), fasting plasma insulin level, fasting and post-oral glucose tolerance test 2-hour glucose levels, liver function test, lipid profile, HOMA-IR were compared according to the presence of AN. Results : Sixty-five percent of patients had AN, 57.1% NASH, 57.1% dyslipidemia, 55.1% hypertension, 46.9% IFG, 24.5% HOMA-IR>3.16 and 16.2% IGT. The patients who were moderately to severely obese with AN had higher incidence of IGT and HOMA-IR>3.16. The patients with AN had significantly higher diastolic BP ($79.4{\pm}6.9$ vs $75.4{\pm}5.6mmHg$), fasting levels of plasma insulin ($10.6{\pm}6.0$ vs $6.2{\pm}5.4{\mu}IU/mL$), HOMA-IR index ($2.6{\pm}1.4$ vs $1.4{\pm}1.3$) and PWH ($42.4{\pm}13.0$ vs $34.3{\pm}1.8%$). The increasing tendency for the presence of AN was significantly related to the cumulative number of obesity induced metabolic complications. Binary logistic regression analysis revealed that the presence of AN was significantly associated with fasting plasma insulin level, PWH and IFG. Conclusion : AN could be useful as a clinical surrogate of obesity induced metabolic complications.

• Journal of Veterinary Clinics
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• v.21 no.4
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• pp.329-335
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• 2004

Dog spermatozoa were recovered from the caudae epididymides of 23 domestic dogs which were 11 pure breed and 12 mix-breed dogs ranging in age from 0.6 to 3 years. The experimental designs were as follows: 1) the effect of chilling to 0. 10 or 37$^{\circ}C$. 2) the kinetics of chilling injury at 0 or 4$^{\circ}C$, and 3) the effect of sugars at $0^{\circ}C$. Viable spermatozoa were recovered by percoll gradient separation and adjusted to 5${\times}$10$^{7}$ spermatozoa/ml. In experiment 1, spermatozoa were diluted with 0.33 M glucose supplemented with 3% BSA (G-BSA) at 1:2 dilution. Spermatozoa were loaded into straws and exposed at 0, 10 or 37$^{\circ}C$ for 30 min. In experiment 2, spermatozoa were prepared as the experiment 1 and exposed for 0.5, 5, 15, or 30 min at 0 or 4$^{\circ}C$. In experiment 3, spermatozoa were diluted with different sugars (0.33 M galactose, glucose, fructose, mannitol, lactose, sucrose, raffinose) and cooled to $0^{\circ}C$ for 30 min. Sperm membrane integrity, motility and acrosome integrity were assayed after rewarming at 37$^{\circ}C$ for 5 min. Sperm motility and membrane integrity abruptly decreased with decreasing temperature but acrosome integrity gradually decreased (P<0.05). Sperm motility was more sensitive to cold shock than membrane integrity and acrosome integrity. Spermatozoa cooled to $0^{\circ}C$ were more damaged than those at 4$^{\circ}C$. Sperm motility was not different among exposed times at both. 0 and 4$^{\circ}C$. However, membrane integrity of spermatozoa exposed for 30 min at both 0 and 4$^{\circ}C$ was significantly lower (P<0.05). Spermatozoa diluted in 0.33 M fructose or galactose showed lower motility and higher morphological abnormality with coiled tail at $0^{\circ}C$. These sperm characteristics were strongly related. These results indicate that dog epididymal spermatozoa are relatively sensitive to rapid cooling and higher morphological abnormality at $0^{\circ}C$ was shown in spermatozoa diluted in fructose and galactose.

• Journal of Chest Surgery
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• v.41 no.1
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• pp.1-11
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• 2008

Background: The Damus-Kaye-Stansel (DKS) procedure is a proximal MPA-ascending aorta anastomosis used to relieve systemic ventricular outflow tract obstructions (SVOTO) and pulmonary hypertension. The purpose of this study was to review the indications and outcomes of the DKS procedure, including the DKS pathway and semilunar valve function. Material and Method: A retrospective review of 28 patients who underwent a DKS procedure between May 1994 and April 2006 was performed. The median age at operation was 5.3 months ($13\;days{\sim}38.1\;months$) and body weight was 5.0 kg ($2.9{\sim}13.5\;kg$). Preoperative pressure gradients were $25.3{\pm}15.7\;mmHg$ ($10{\sim}60\;mmHg$). Eighteen patients underwent a preliminary pulmonary artery banding as an initial palliation. Preoperative main diagnoses were double outlet right ventricle in 9 patients, double inlet left ventricle with ventriculoarterial discordance in 6,. another functional univentricular heart in 5, Criss-cross heart in 4, complete atrioventricular septal defect in 3, and hypoplastic left heart variant in 1. DKS techniques included end-to-side anastomosis with patch augmentation in 14 patients, classical end-to-side anastomosis in 6, Lamberti method (double-barrel) in 3, and others in 5. The bidirectional cavopulmonary shunt and Fontan procedure were concomitantly performed in 6 and 2 patients, respectively. Result: There were 4 hospital deaths (14.3%), and 3 late deaths (12.5%) with a follow-up duration of $62.7{\pm}38.9$ months ($3.3{\sim}128.1$ months). Kaplan-Meier estimated actuarial survival was $71.9%{\pm}9.3%$ at 10 years. Multivariate analysis showed right ventricle type single ventricle (hazard ratio=13.960, p=0.004) and the DKS procedure as initial operation (hazard ratio=6.767, p=0.042) as significant mortality risk factors. Four patients underwent staged biventricular repair and 13 received Fontan completion. No SVOTO was detected after the procedure by either cardiac catheterization or echocardiography except in one patient. There was no semiulnar valve regurgitation (>Gr II) or semilunar valve-related reoperation, but one patient (3.6%) who underwent classical end-to-side anastomosis needed reoperation for pulmonary artery stenosis caused by compression of the enlarged DKS pathway. The freedom from reoperation for the DKS pathway and semilunar valve was 87.5% at 10 years after operation. Conclusion: The DKS procedure can improve the management of SVOTO, and facilitate the selected patients who are high risk for biventricular repair just after birth to undergo successful staged biventricular repair. Preliminary pulmonary artery banding is a safe and effective procedure that improves the likelihood of successful DKS by decreasing pulmonary vascular resistance. The long-term outcome of the DKS procedure for semilunar valve function, DKS pathway, and relief of SVOTO is satisfactory.