• Korean Journal of Biological Psychiatry
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• v.25 no.2
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• pp.38-43
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• 2018

Objectives Dopamine dysregulation has been regarded as one of the core pathologies in patients with schizophrenia. Since dopamine synthesis capacity has found to be inconsistent in patients with schizophrenia, current classification of patients based on clinical symptoms cannot reflect the neurochemical heterogeneity of the disease. Here we performed new subtyping of patients with first-episode psychosis (FEP) through biotype-based cluster analysis. We specifically suggested basal ganglia structural changes as a biotype, which deeply involves in the dopaminergic circuit. Methods Forty FEP and 40 demographically matched healthy participants underwent 3T T1 MRI. Whole brain parcellation was conducted, and volumes of total 6 regions of basal ganglia have been extracted as features for cluster analysis. We used K-means clustering, and external validation was conducted with Positive and Negative Syndrome Scale (PANSS). Results K-means clustering divided 40 FEP subjects into 2 clusters. Cluster 1 (n = 25) showed substantial volume decrease in 4 regions of basal ganglia compared to Cluster 2 (n = 15). Cluster 1 showed higher positive scales of PANSS compared with Cluster 2 (F = 2.333, p = 0.025). Compared to healthy controls, Cluster 1 showed smaller volumes in 4 regions, whereas Cluster 2 showed larger volumes in 3 regions. Conclusions Two subgroups have been found by cluster analysis, which showed a distinct difference in volume patterns of basal ganglia structures and positive symptom severity. The result possibly reflects the neurobiological heterogeneity of schizophrenia. Thus, the current study supports the importance of paradigm shift toward biotype-based diagnosis, instead of phenotype, for future precision psychiatry.

• Development and Reproduction
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• v.23 no.1
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• pp.35-42
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• 2019

Fish shows great difference in growth rate between individuals during larval development and early growth. This difference seriously reduces the production efficiency in fish culture. Growth hormone (GH)/Insulin-like growth factor 1 (IGF1) system is said to play some pivotal roles in fish growth. In this study, we investigated differences of GH, IGF1 and GHR gene expressions in juvenile red spotted grouper (Epinephelus akaara) with different growth performance. Red spotted groupers were reared under the same environmental condition (water temperature $24{\pm}1^{\circ}C$, natural light) for 96 days after hatching. They were divided into 3 groups by size (fast growing, middle growing and slow growing groups: FGG, MGG, and SGG, respectively). RNA was extracted from the brain, liver and muscle tissues from each group, and target gene expression was examined by real-time PCR. In the brain with pituitary gland, expression of GH gene in FGG was significantly higher than the expression in SGG, but the expression of IGF1 and GHR genes in the muscle was highest in SGG. Difference of GHR and IGF1 mRNA in the liver between groups with different growth performance was less clear than that in other tissues, although level of IGF1 mRNA was higher in SGG than in MGG. These results suggest that hormonal governing of growth is not the same in fast growing and slow growing fish, and size grading could cause a shift of hormonal state and growth pattern in this species.

• Investigative Magnetic Resonance Imaging
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• v.6 no.1
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• pp.64-72
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• 2002

Purpose : To introduce and demonstrate the advantages of the new hybrid two-dimensional (2D) proton spectroscopic imaging (SI) over the single voxel spectroscopy (SVS) and conventional 2D SI in the clinical application of spectroscopy for pediatric cerebral disease. Materials and Methods : Eighty-one hybrid 2D proton spectroscopic imaging was performed in 79 children (36 normal infants and children, 10 with hypoxic-ischemic injury, 20 with toxic-metabolic encephalopathy, seven with brain tumor, three with meningoencephalitis, one with neurofibromatosis, one with Sturge-Weber syndrome and one with lissencephaly) ranging in age from the third day of life to 15 years. In adult volunteers (n=5), all three techniques including hybrid 2D proton SI, SVS using PRESS sequence, and conventional 2D proton SI were performed. Both hybrid 2D proton SI and SVS using PRESS sequence were performed in clinical cases (n=). All measurements were performed with a 1.5-T scanner using standard head quadrature coil. The 16$\times$16 phase encoding steps were set on variable field of view (FOV) depending on the size of the brain. The hybrid volume of interest inside FOV was set as $75{\times}75{\times}15{\;}\textrm{mm}^3$ or smaller to get rid of unwanted fat signal. Point-resolved spectroscopy (TR/TE=1,500 msec/135 or 270msec) was employed with standard chemical shift selective saturation (CHESSI pulses for water suppression. The acquisition time and spectral quality of hybrid 2D proton SI were compared with those of SVS and conventional 2D proton SI. Results : The hybrid 2D proton SI was successfully conducted upon all patients.

• Journal of Korean Neurosurgical Society
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• v.49 no.6
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• pp.355-358
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• 2011

Objective : Subdural hygroma (SDG) is a complication occurring after head trauma that may occur secondary to decompressive craniectomy (DC). However, the mechanism underlying SDG formation is not fully understood. Also, the relationship between the operative technique of DC or the decompressive effect and the occurrence and pathophysiology of SDG has not been clarified. Purpose of this study was to investigate the risk factors of SDG after DC in our series. Methods : From January 2004 to December 2008, DC was performed in 85 patients who suffered from traumatic brain injury. We retrospectively reviewed the clinical and radiological features. For comparative analysis, we divided the patients into 2 groups : one group with SDG after craniectomy (19 patients; 28.4% of the total sample), the other group without SDG (48 patients; 71.6%). The risk factors for developing SDG were then analyzed. Results : The mean Glasgow Outcome Scale (GOS) scores at discharge of the groups with and without SDG were 2.8 and 3.1, respectively (p<0.0001). Analysis of radiological factors showed that a midline shift in excess of 5 mm on CT scans was present in 19 patients (100%) in the group with SDG and in 32 patients (66.7%) in the group without SDG (p<0.05). An accompanying subarachnoid hemorrhage (SAH) was seen in 17 patients (89.5%) in the group with SDG and in 29 patients (60.4%) in the group without SDG (p<0.05). Delayed hydrocephalus accompanied these findings in 10 patients (52.6%) in the group with SDG, versus 5 patients (10.4%) in the group without SDG (p<0.05). On CT, compression of basal cisterns was observed in 14 members (73.7%) in the group with SDG and in 18 members of the group without SDG (37.5%) (p<0.007). Furthermore, tearing of the arachnoid membrane, as observed on CT, was more common in all patients in the group with SDG (100%) than in the group without SDG (31 patients; 64.6%) (p<0.05). Conclusion : GOS showed statistically significant difference in the clinical risk factors for SDG between the group with SDG and the group without SDG. Analysis of radiological factors indicated that a midline shifting exceeding 5 mm, SAH, delayed hydrocephalus, compression of basal cisterns, and tearing of the arachnoid membrane were significantly more common in patients with SDG.

• Journal of Korean Neurosurgical Society
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• v.39 no.5
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• pp.370-373
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• 2006

The case of postoperative hemorrhage occurring apart from the operative site as a complication of intracranial surgery is a rare malady, especially when it involves the cerebellum after supratentorial aneurysm surgery. In a review of the literature, the possible etiologies for cerebellar hemorrhage are: coagulopathy, intraoperative urokinase irrigation, excessive head rotation on positioning, brain shift due to excessive cerebrospinal fluid[CSF] and epidural hemovac drainage. We experienced six cases of cerebellar hemorrhage after supratentorial aneurysm surgery, and all of the patients were improved by instituting conservative medical treatment. The possible mechanism for the remote cerebellar hemorrhages seen in our series is probably a multifactorial effect, such as excessive epidural hemovac and CSF drainage, and jugular venous compression due to the operative position. The purpose of this report is to alert neurosurgeons to the existence of this syndrome and to suggest several ways of minimizing the possibility of their patients developing remote cerebellar hemorrhage.

• Journal of Korean Neurosurgical Society
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• v.45 no.3
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• pp.143-150
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• 2009

Objective : The purpose of this study was to investigate the reliable factors influencing the surgical outcome of the patients with traumatic acute subdural hematoma (ASDH) and to improve the functional outcome of these patients. Methods : A total of 256 consecutive patients who underwent surgical intervention for traumatic ASDH between March 1998 and March 2008 were reviewed. We evaluated the influence of perioperative variables on functional recovery and mortality using multivariate logistic regression analysis. Results : Functional recovery was achieved in 42.2% of patients and the overall mortality was 39.8%. Age (OR=4.91, p=0.002), mechanism of injury (OR=3.66, p=0.003), pupillary abnormality (OR=3.73, p=0.003), GCS score on admission (OR=5.64, p=0.000), and intraoperative acute brain swelling (ABS) (OR=3.71, p=0.009) were independent predictors for functional recovery. And preoperative pupillary abnormality (OR=2.60, p=0.023), GCS score (OR=4.66, p=0.000), and intraoperative ABS (OR=4.16, p=0.001) were independent predictors for mortality. Midline shift, thickness and volume of hematoma, type of surgery, and time to surgery showed no independent association with functional recovery, although these variables were correlated with functional recovery in univariate analyses. Conclusion : Functional recovery was more likely to be achieved in patients who were under 40 years of age, victims of motor vehicle collision and having preoperative reactive pupils, higher GCS score and the absence of ABS during surgery. These results would be helpful for neurosurgeon to improve outcomes from traumatic acute subdural hematomas.

• Biomolecules & Therapeutics
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• v.25 no.4
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• pp.390-395
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• 2017

The present study investigated the sedative effects of Sophora flavescens (SF) and its bioactive compound, matrine through performing locomotor activity test and the electroencephalography (EEG) analysis in the rat. The underlying neural mechanism of their beneficial effects was determined by assessing c-Fos immunoreactivity and serotonin (5-HT) in the brain utilizing immunohistochemical method and enzyme-linked immunosorbent assay. The results showed that SF and matrine administration had an effect on normalization of caffeine-induced hyperactivity and promoting a shift toward non-rapid eye movement (NREM) sleep. c-Fos-immunoreactivity and 5-HT level in the ventrolateral preoptic nucleus (VLPO), a sleep promoting region, were increased in the both SF and matrine-injected groups. In conclusion, SF and its bioactive compound, matrine alleviated caffeine-induced hyperactivity and promoted NREM sleep by activating VLPO neurons and modulating serotonergic transmission. It is suggested that SF might be a useful natural alternatives for hypnotic medicine.

• Journal of the Optical Society of Korea
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• v.15 no.2
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• pp.132-139
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• 2011

We investigate theoretically the combined effect of fiber chromatic dispersion and self-phase modulation (SPM) on multi-channel subcarrier multiplexed (SCM) optical transmission systems in terms of the detected RF carrier power and SPM-induced power gain after transmission over single-mode fiber (SMF) links. According to the calculated power gain due to the SPM effect at the transmission distance of P3dB using the detected radio-frequency (RF) carrier power after photo-detection, the power gain is significantly degraded with large optical modulation index (OMI), small SCM channel spacing, and large fiber launching power because of the increased interaction between subcarrier channels. The nonlinear phase shift due to linear and nonlinear fiber characteristics is investigated to explain these results in detail. The numerical simulation results show that the OMI per SCM channel has to be smaller than 10 % for the fiber launching power of 10 dBm to guarantee prevention of SPM-induced power gain degradation below 0.5 dB for the SCM system with the channel spacing of 100 MHz. This result is expected to be utilized for the optical transmission systems using the SCM technology in future radio-over-fiber (RoF) networks.

• Journal of the Korean Medical Association
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• v.61 no.12
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• pp.732-739
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• 2018

The frontal sinus is a functionally important structure. It serves as a cushioning buffer to protect the brain in cases of facial trauma. Fractures of the frontal sinus can lead to aesthetic problems by causing a visible depression in the center of the forehead. The goals of frontal sinus fracture treatment have been to protect intracranial structures and to prevent early and late complications, even with invasive methods. Recently, however, the goals have shifted to preservation of nasofrontal outflow tract function through close observation and the utilization of endoscopic procedures. Excellent cosmetic results can be achieved through minimally invasive surgery. This shift in goals took place due to the ease of diagnosis and treatment of early and late complications. Therefore, patients with a frontal sinus fracture should be followed up continuously to ensure that complications are detected promptly. Herein, the authors describe the methods and current trends of frontal sinus fracture treatment.

• Journal of the Korean Society of Radiology
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• v.83 no.3
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• pp.453-472
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• 2022

Over the past decades, the immense clinical need for early detection methods and treatments for dementia has become a priority worldwide. The advances in PET biomarkers play increasingly important roles in understanding disease mechanisms by demonstrating the protein pathology underlying dementia in the brain. Amyloid-β and tau deposition in PET images are now key diagnostic biomarkers for the Alzheimer's disease continuum. The inclusion of biomarkers in the diagnostic criteria has achieved a paradigm shift in facilitating early differential diagnosis, predicting disease prognosis, and influencing clinical management. Furthermore, in vivo images showing pathology could become prognostic as well as surrogate biomarkers in therapeutic trials. In this review, we focus on recent developments in radiotracers for amyloid-β and tau PET imaging in Alzheimer's disease and other neurodegenerative diseases. Further, we introduce their potential application as future perspectives.