• Korean Journal of Biological Psychiatry
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• v.22 no.4
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• pp.205-215
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• 2015

Objectives Sex hormones exposure during the prenatal period has an effect on cerebral lateralization. Male brains are thought to be more lateralized than female brains. Bipolar disorder was known to show abnormalities in cerebral laterality whose characteristics could be estimated by electroencephalography (EEG) coherences. We studied sex-related differences of EEG coherences between healthy controls and patients with bipolar disorder to examine the sex effects in the genesis of bipolar disorder. Methods Participants were 25 patients with bipolar disorder (11 male, 14 female) and 46 healthy controls (23 male, 23 female). EEG was recorded in the eyes closed resting state. To examine dominant EEG coherence associated with sex differences in both groups within five frequency bands (delta, theta, alpha, beta, and gamma) across several brain regions, statistical analyses were performed using analysis of covariance. Results Though statistically meaningful results were not found, some remarkable findings were noted. Healthy control females showed more increased interhemispheric coherences than control males in gamma frequency band. There were no differences in the intrahemispheric coherences between the healthy control males and females. In patients with bipolar disorder, female dominant pattern in interhemispheric coherences was attenuated compared with healthy control. Conclusions Sex differences of EEG coherences, which could be a marker for cerebral laterality, were attenuated in patients with bipolar disorder compared with healthy controls. These results imply that abnormal sex hormone exposure during early development might play some role in the pathogenesis of bipolar disorder.

• Journal of the Korean Society of Radiology
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• v.81 no.4
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• pp.979-984
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• 2020

Cri-du-chat syndrome is a rare genetic disorder in which the patient presents with a characteristic high-pitched monotonous cry and recurrent aspiration pneumonia, attributed to abnormalities in the larynx, epiglottis, and nervous system. The most prominent brain MRI findings are the presence of pontine and cerebellar hypoplasia, which primarily involve posterior cranial fossa structures. Although atrophy of supratentorial structures were also a common radiological finding, it was considered to be a secondary change due to pontine hypoplasia. Here, we present the case of a three-month-old patient presenting with cri-du-chat at our institution. The patient also showed the presence of prominent pontine hypoplasia similar to previously reported cases; however, contrary to other cases, there was a general delayed myelination of brain instead of decreased myelination of anterior limb of internal capsule. Since the larynx, pons, and cerebellum all originated from similar notochord level, which suggests anomaly in early stage of development, laryngeal, and brain anomaly characteristically observed in the cridu-chat syndrome.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.97-97
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• 2003

For many animals the centrosome consists of a pair of centrioles and surrounding pericentriolar materials (PCMs). PCMs have been known to play roles during cell division. It is known that centrioles are necessary to assemble centrosomal components. However, many types of oocytes undergo meiosis without centrioles. It is known that in nonmurine mammalian species, the sperm introduces an intact proximal centriole unlike sea urchin where two centrioles are introduced. In case of mouse sperm, the presence of centrosome is not clear In this study, a monoclonal antibody was developed to investigate centrosome during mouse germ cell and early embryo development. Results of immunostaining and Western blotting in CHO cells suggest that the monoclonal antibody recognizes a nuclear and centrosomal protein, thus called NCP. The NCP monoclonal antibody was used to screen a cDNA expression library prepared from 12.5 mouse brain to isolate NCP gene. Nucleotide size of NCP gene obtained from immunoscreening was about 5.5kb. It is determined that the NCP may be closely related with pericentriolar material -1 gene (Pcm-1) from the result of sequencing analysis. The molecular weight, 66kDa, calculated by known DNA sequence in database is consistent with that of detected from Western blotting using CHO cell lysates. Therefore, it is assumed that NCP may be alternative splicing form of Pcm-1 of which molecular weight is 228kDa. In mouse oocytes, NCP was distributed in nucleus as in CHO cells. It was shown that the NCP was localized around neck region, probably the centrosome in mouse neck region. Interestingly, dramatic change in distribution of NCP was also shown in male germ cell development. Finally, we observed the cellular distribution of NCP during early embryo development. NCP was detected in nucleus as well as centrosome foci. It is suggested that the centrioles reassembly we occurring in blastocysts and then affects the distribution of NCP.

• Development and Reproduction
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• v.16 no.4
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• pp.371-378
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• 2012

Notch signaling plays fundamental roles in various animal development. It has been suggested that Hr-Notch, a Notch homologue in the ascidian Halocynthia roretzi, is involved in the formation of peripheral neurons by suppressing the neural fates and promoting the epidermal differentiation. However, roles of Notch signaling remain controversial in the formation of nervous system in ascidian embryos. To precisely investigate functions of Notch signaling, we have isolated and characterized Hr-Numb, a Numb homologue which is a negative regulator of Notch signaling, in H. roretzi. Maternal expression of Hr-Numb mRNAs was detected in egg cytoplasm and the transcripts were inherited by the animal blastomeres. Its zygotic expression became evident by the early neurula stage and the transcripts were detected in dorsal neural precursor cells. Suppression of Hr-Numb function by an antisense morpholino oligonucleotide resulted in larvae with defect in brain vesicle and palps formation. Similar results have been obtained by overexpression of the constitutively activated Hr-Notch forms. Therefore, these results suggest that Hr-Numb is involved in Notch signaling during ascidian embryogenesis.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.129-131
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• 2009

Hearing loss is one of the most common birth defects among infants. Most hearing-impaired children are not diagnosed until one to three years of age, which is too late to treat for normal speech and language development. If a hearing impairment is identified and treated in its early stage, child's speech and language skills could be comparable to his or her normal-hearing peers. In this study, we applied the 'Fsp' method to distinguish between normal and impaired hearing. We have developed a battery-operated portable A - ABR(automated auditory brain stem response) system that automatically detects hearing impairment for neonates or infants in a nursery room, as well as in a sound-proof room. We partially validated the accuracy of the system in five normal-hearing adults.

• The Korean Journal of Zoology
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• v.32 no.1
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• pp.55-73
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• 1989

The effect of tryptophan or serotonin on the early stage of chick brain development has been morphologically investigated using an electron microscope. The electron micrographs of neural plate cells of 1-day chick embryo treated with tryptophan or serotonin showed irregularity, evagination and disruption of nuclear membrane and nuclear chromatin condenstation, nucleolar margination and segregation. Hypertrophy of stalks, vesicles and vaculoes were seen and dilated and disrupted rough endoplasmic reticulum and underdeveloped neurotubules were also observed. In mesenchyme cells of tryptophan or serotonin administered 18 hr embryo, irregular nuclear membrane, swollen mitochondria, dilated rough endoplasmic reticulum and very large yolk granules were observed. Furthermore, DNA, RNA and protein contents of the embryos treated with typtophan or serotonin were considerably lower than those of control group. The amount of tubulin of the experimental groups was also greatly lower than that of control, suggesting that the impairment of microtubule formation occurred. Tryptophan or serotonin administration might depress the biosynthesis, of nucleic acid and protein including some enzymes tested. It seems that the serotonin formed from exogeneous tryptophan might inhibit the degradation of yolk granule by feedback regulation mechanism so as to impair microtububle and microvilli formation followed by a malformation of chick embryos.

• Journal of the Korean Society of Radiology
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• v.83 no.3
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• pp.473-485
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• 2022

The incidence of neurodegenerative diseases in the older population has increased in recent years. A considerable number of studies have been performed to characterize these diseases. Imaging analysis is an important biomarker for the diagnosis of neurodegenerative disease. Objective and reliable assessment and precise detection are important for the early diagnosis of neurodegenerative diseases. Artificial intelligence (AI) using brain MRI applied to the study of neurodegenerative diseases could promote early diagnosis and optimal decisions for treatment plans. MRI-based AI software have been developed and studied worldwide. Representatively, there are MRI-based volumetry and segmentation software. In this review, we present the development process of brain volumetry analysis software in neurodegenerative diseases, currently used and developed AI software for neurodegenerative disease in the Republic of Korea, probable uses of AI in the future, and AI software limitations.

• Journal of Nutrition and Health
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• v.29 no.8
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• pp.849-860
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• 1996

The supply of different fatty acids during the development period has significant effects. This study examined the effects of dietary $\omega$3 and $\omega$6 fatty acid compositions on phospholipids (PLs) of RBC and rat brain subcellular fractions (synaptosome, microsome, mitochondria), and on learning ability of the 2nd generation rat. Rats were fed experimental diets 3-4 wks prior to the conception. Early in the lactation period, the feeding mothers were exchanged. Diets consisted of 10% fat(by weight), which was either safflower oil('S') poor in $\omega$3 fatty acids or computer-searched mixed oil('M') with P/M/S ratio, 1/1.4/1 and $\omega$6/$\omega$3 ratio, 6.1/1. The 'S' and 'M' rats were subdivided further into SS, SM, MS & MM rats according to their lactation stauts. At 3 (weaning) & 9 wks of age, the percentage of total $\omega$3 fatty acids to their lactation status. At 3 (weaning) & 9 wks of age, the percentage of total $\omega$3 fatty acids and the ratios of $\omega$3/$\omega$6 fatty acids in PLs of RBC and brain subcellular fractions in SM and MM groups fed milk from the mixed oil-fed mothers for 2 wks tended to be higher than those in SS and MS groups respectively. In contrast, the concentrations of $\omega$6 fatty acids, especially 22:5$\omega$6 in all fractions, were significantly lower in the SM & MM groups compared to those of the SS & MS groups respectively. In contrast, the concentration of $\omega$6 fatty acids, especially 22:5$\omega$6 in all fractions, were significantly lower in the SM & MM groups compared to those of the SS & MS groups, The values for the DHA$\omega$3/22:5$\omega$6 ratios after the lactation period were markedly higher in the groups (SM & MM) which were reared by mixed oil(MO) fed mothers. In carring out Y-water maze at 9th wk of age, the SM(4.2$\pm$0.5) & MM (5.3$\pm$0.5) groups made significantly less errors compared to the SS(6.2$\pm$0.6, p<0.05 compared with SM) & MM (7.2$\pm$0.5, p<0.05 compared with MM) groups which were lactated by the safflower oilfed mothers. Therefore, by feeding a balanced fatty acid diet from the lactation period up to 9 wks of age as compared with the groups fed $\omega$3 fatty acid-deficient diet regardless of mother's diet given before parturition. The levels of DHA(synaptosome) and 22:5$\omega$3 (mitochondria) were positively correlated not only with these values in RBC but also with visual discriminating ability. The levels of DHA and 22:5$\omega$3 in RBC can, therfore, reflect visual discriminatng ability in the rat.

• Korean Journal of Veterinary Research
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• v.59 no.4
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• pp.201-205
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• 2019

This study presents neurogenesis and neuronal migration patterns of gamma-aminobutyric acid-ergic (GABAergic) neurons during mesencephalic development of mouse. After neurons from embryonic day (E) 10-16 were labelled by a single injection of 5-bromo-2'-deoxyuridine (BrdU), immunohistochemistry was performed. Neurogenesis were mainly generated in the mesencephalic region at E10 to E13. After E14, BrdU positive cells were observed only in the dorsal mesencephalon. GABAergic neurons were mainly originated in the ventrolateral region of the mesencephalon at the early embryonic stage, especially at E11 to E13. E10-labeled cells showed positive for GABAergic neuron in the basal plate of the mesencephalon at E13. At E15, GABAergic neurons were observed in the entire basal plate and some regions of the ventral and dorsal mesencephalon. They were present in the whole basal plate, the ventral and dorsal mesencephalon of E17, spreading more outward of the mesencephalon at P0. Our study demonstrates that major neurogenesis of GABAergic neurons occurs at E11 to E13. However, neuronal migration continues until neonatal period during mesencephalic development.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.454-461
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• 2017

This study was conducted to investigate the optimal conditions for spore germination, prothallus propagation, sporophyte formation, and seedling growth in Polystichum braunii (Spenn.) $F{\acute{e}}e$. The rate of spore germination and early prothalium development was high in Knop (41.2%), which had low mineral content. The optimal medium for prothallus propagation and sexual organ formation was 2MS medium (2% sucrose). Among the various mixtures of cultivation soil (bedding soil, peat moss, perlite, and decomposed granite), a mixture of bedding soil and decomposed granite at a ratio of 2:1 (v:v) had a positive effect on sporophyte formation (276.3 ea/$7.5m^2$). The most efficient conditions for promoting the growth of sporophytes were pots filled with only bedding soil.