Biomedical subjects

Dal-Soo Kim

Publications and source records attributed to Dal-Soo Kim.

9 recordsLinked to original sources

PubMed2006

Surgical results in pediatric moyamoya disease: angiographic revascularization and the clinical results.

OBJECTIVE: We retrospectively reviewed the pediatric patients with moyamoya disease (MMD) who underwent bypass surgery at our institution to compare the surgical results according to the surgical procedures. PATIENTS AND METHODS: There were 24 total patients (age range: 2-15 years; mean age: 8.2 years). Twelve patients underwent encephalo-duro-arterio-synangiosis (EDAS) on 16 sides, 5 patients underwent encephalo-duro-arterio-myo-synangiosis (EDAMS) on 8 sides and 7 patients underwent combined superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis with EDAMS (STA-MCA-EDAMS) on 12 sides. The postoperative results were evaluated between 4 months and 5 years following surgery in terms of the angiographic revascularization and the clinical outcome. RESULTS: EDAMS, regardless of the combined STA-MCA anastomosis, was significantly effective for achieving a good extent of the postoperative angiographic revascularization as compared with simple EDAS (P<0.05). STA-MCA-EDAMS tended to be better with respective to the relief of preoperative ischemic symptoms as compared with simple EDAS, although there was no significant statistical difference. CONCLUSION: These results suggest that EDAMS with or without the combination of STA-MCA anastomosis was very useful for the formation of collateral circulation in comparison with simple EDAS for treating the pediatric patients with MMD, although these findings were not well correlated with the clinical outcomes.

Adolescent↗

PubMed2006

Combined direct anastomosis and encephaloduroarteriogaleosynangiosis using inverted superficial temporal artery-galeal flap and superficial temporal artery-galeal pedicle in adult moyamoya disease.

BACKGROUND: We evaluated the efficacy of combined STA-MCA anastomosis and EDAGS using inverted STAGF and STAGP for the treatment of adult MMD. METHODS: This study included 8 patients with nonhemorrhagic MMD. There were 6 women and 2 men who were between 23 and 62 years old (mean = 37.8 years) in the sample. The combined surgery was performed on 12 sides in the 8 patients. The surgical results were assessed for clinical outcome, angiographic revascularization, and hemodynamic change on HMPAO brain SPECT. The follow-up period ranged from 6 to 62 months (mean = 27 months). RESULTS: Clinical symptoms and signs were improved or stabilized, and the extent of revascularization evident on external carotid angiograms was excellent in all 8 patients. The CBF on HMPAO SPECT also improved in all 12 sides that were operated on with the combined surgery, except for the preexisting infarcted area, on the basal as well as Diamox stimulation studies. One patient had a transient speech disturbance after surgery, and another patient had delayed wound healing. CONCLUSIONS: The combined STA-MCA anastomosis and EDAGS using inverted STAGF/P seems to be one of the most effective surgical modalities for the treatment of nonhemorrhagic MMD in adults.

Adult↗

PubMed2006

Diagnostic method for differentiating external hydrocephalus from simple subdural hygroma.

OBJECT: The various terms used to describe subdural fluid collection--"external hydrocephalus", "subdural hygroma", "subdural effusion", "benign subdural collection", and "extraventricular obstructive hydrocephalus"-reflect the confusion surrounding the diagnoses of these diseases. Differentiating external hydrocephalus from simple subdural hygroma may be difficult, but the former appears to be a distinct clinical entity separate from the latter. In this report, the authors present a diagnostic method for differentiating external hydrocephalus from simple subdural hygroma, based on their clinical experience in treating subdural fluid collection after mild head trauma. METHODS: Twenty patients with subdural fluid collection after mild head trauma were included in this study. Ventricle size was measured using a modified frontal horn index (mFHI); that is, the largest width of the frontal horns divided by the bicortical distance in the same plane, instead of the inner table distance. Bur hole trephination was performed on the appearance of a subdural fluid collection thicker than 15 mm on computed tomography (CT), persistent (longer than 4 weeks) or increasing in size, and accompanied by neurological symptoms (confusion or memory impairment). During the procedure, subdural pressure was measured using a manometer before opening the dura mater. Subdural pressure varied among the patients, ranging from 3 to 27.5 cm H2O. Four patients with a subdural pressure greater than 15 cm H2O had hydrocephalus after surgery (p < 0.05). Hydrocephalus developed in a pediatric patient (2 years old) with a subdural pressure of 12 cm H2O. All of the patients in whom hydrocephalus developed after bur hole trephination had had enlarged ventricles (mFHI > 33%) on preoperative CT scans. CONCLUSIONS: Monitoring subdural pressure may be a valuable tool for differentiating subdural hygroma from external hydrocephalus in patients with mild head trauma. Additionally, the mFHI reflects the nature of the subdural collection more accurately than the standard frontal horn index.

Adolescent↗

PubMed2005

Role of phospholipase D1 in neurite outgrowth of neural stem cells.

Employing neural stem cells from the brain cortex of E12 rat embryos, we investigated the possible role of phospholipase D (PLD) in the synaptogenesis and neurite formation of neural cells during differentiation. Expression level of PLD1 increased during neuronal differentiation of the neural stem cells, resulting in increased PLD activity. Expression level of synapsin I, a marker of synaptogenesis, also increased as the differentiation of neural stem cells progressed. To figure out the effect of PLD on synapsin I expression, we treated the neural stem cells with phorbol myristate acetate (PMA) to stimulate PLD activity. Increased PLD activity induced by PMA treatment resulted in elevated synapsin I expression and neurite outgrowth during neuronal differentiation. To further confirm the role of PLD in neurite outgrowth, we transfected the dominant-negative form of rat PLD1 cDNA (DN-rPLD1) into neural stem cells to downregulate PLD activity. Overexpression of DN-rPLD1 showed the complete inhibition of neurite outgrowth of neural stem cells under differentiation condition. While transfection of DN-rPLD1 did not affect the synapsin I expression, overexpression of rPLD1 resulted in increased synapsin I expression of the neural cells. These results suggest that PLD1 plays a critical role in neurite outgrowth during differentiation of the neural stem cells. In conclusion, this is the first evidence to show that PLD1 acts as an important regulator of neurite outgrowth in neural stem cell by promoting neuronal differentiation via increase of synapsin I expression.

Animals↗

PubMed2005

In vivo effects of the fungicide ethaboxam on microtubule integrity in Phytophthora infestans.

The effects of ethaboxam (LGC-30473), a novel thiazole carboxamide, on microtubule organization was investigated in Phytophthora infestans (Mont) de Bary (Oomycota) at the light microscope level using standard immunofluorescence and laser scanning confocal microscopy. Hyphal cells were exposed to various concentrations ranging from 0.01 to 1.0 microg ml(-1) of ethaboxam at incubation times of 30, 60 and 120 min. Microtubules were disrupted after exposure to ethaboxam for 30 min at 0.01 microg ml(-1). Similar experimental conditions were used to document the effects of ethaboxam on microtubule integrity in the model fungus Aspergillus nidulans (Eidam) Winter (Ascomycota) and in mammalian mouse 17 clone 1 cells. Under these conditions, there was no evidence to suggest that microtubules in A. nidulans and mouse culture cells were affected by the ethaboxam. These results indicate that ethaboxam is specific for the targeting of microtubule disruption in P. infestans.

Animals↗

PubMed2004

Synthesis and fungicidal activity of ethaboxam against Oomycetes.

This study describes the chemical synthesis and intrinsic fungicidal activity of ethaboxam [(RS)-N-(alpha-cyano-2-thenyl)-4-ethyl-2-(ethylamino)-1,3-thiazole-5-carboxamide], a new Oomycetes fungicide. In in vitro tests, ethaboxam showed inhibitory activity against isolates of Phytophthora and some Pythium spp, with MIC values ranging from 0.1 to 0.5 mg litre(-1) for nine isolates of Phytophthora infestans (Montagne) de Bary and from 1.0 to 5.0 mg litre(-1) for eight isolates of Phytophthora capsici Leonian. In tests to determine time and concentration for complete inactivation of each pathogen (five isolates of P infestans and five isolates of P capsici), ethaboxam inactivated all isolates of P infestans within 48h at 10 mg litre(-1) and those of P capsici within 96 h at 10 mg litre(-1). Ethaboxam effectively suppressed development of tomato late blight caused by P infestans and pepper Phytophthora blight caused by P capsici in the studies conducted to determine its preventive, curative, persistent and systemic activity. These results show that ethaboxam has desirable fungicidal characteristics as an Oomycetes fungicide.

Fungicides, Industrial↗

PubMed2004

Paenibacillus elgii sp. nov., with broad antimicrobial activity.

Two novel spore-forming bacteria with broad antimicrobial activity were isolated from roots of Perilla frutescens. The isolates, SD17(T) and SD18, were facultatively anaerobic and showed variable Gram reaction. Growth was observed between 20 and 45 degrees C. DNA G+C content of SD17(T) was 51.7 mol%, and the major fatty acid was anteiso-C(15 : 0) (54.1 %). 16S rRNA gene sequence similarity of SD17(T) ranged from 98.6 to 91.3 % with other Paenibacillus species. The phylogenetic tree showed that isolate SD17(T) formed a significant monophyletic clade with Paenibacillus koreensis KCTC 2393(T) and Paenibacillus ehimensis IFO 15659(T). DNA-DNA relatedness values for strain SD17(T) with Paenibacillus koreensis KCTC 2393(T) and Paenibacillus ehimensis IFO 15659(T) were 17.4 and 19.8 %, respectively. These isolates thus merit species status within Paenibacillus, for which the name Paenibacillus elgii sp. nov. is proposed. The type strain is SD17(T) (=KCTC 10016BP(T)=NBRC 100335(T)).

Anaerobiosis↗

PubMed2003

Advanced lipid extraction method for the determination of the phospholipase D activity.

Phospholipase D is a ubiquitous enzyme that plays an important role in various lipid mediated cellular signaling pathways and produces rare phospholipids, phosphatidylethanol or phosphatidylbutanol, instead of phosphatidic acid with unique catalytic activity transphosphatidylation in the presence of primary alcohols. The reaction products, phosphatidylethanol or phosphatidylbutanol are used as markers of in vitro phospholipase D activity in many studies. For the sensitive detection of the phospholipase D products, we developed an advanced lipid extraction method that facilitates recovery of the compounds. With the new method, the activity change of phospholipase D by agonists could be detected more easily and the recovery rate was also increased. The increase of detected enzyme activity change was about double fold compared to the conventional lipid extraction method. This method provides selective force for the phospholipase D products in the extraction procedure.

Cell Line, Tumor↗

PubMed2003

Associations of Moyamoya patients with HLA class I and class II alleles in the Korean population.

Moyamoya disease is characterized by progressive cerebrovascular occlusion at the peripheral internal carotid artery and development of abnormal collateral circulation at the cerebral basal region. Although abnormal thrombogenesis, inflammation and autoimmune process might be involved in the etiology, the genetic pathogenesis of Moyamoya disease is still unknown. To evaluate the association of Moyamoya disease with HLA alleles in the Korean population, we investigated HLA class I and class II alleles in 28 Moyamoya patients and 198 unrelated healthy controls. The frequency of HLA-B35 allele was significantly increased in the patients compared to the controls (32.1% vs. 10.1%, RR=4.2, p<0.008). Further analysis of HLA-B35 on onset age and sex showed that this allele was significantly increased compared to the controls in both late-onset and female group. Especially, HLA-B35 was the most significantly increased in female of late-onset group compared to the controls. These results suggest that HLA-B35 may be an useful genetic marker for Moyamoya disease, and particularly in females of late onset group in the Korean population.

Adolescent↗