Biomedical subjects

S-G Kim

Publications and source records attributed to S-G Kim.

7 recordsLinked to original sources

PubMed2006

Metastatic tumours to the jaws and oral soft tissues: a retrospective analysis of 41 Korean patients.

This article describes a pooled analysis of 41 Korean patients with metastatic oral tumours. The data reviewed are from Korean dental and medical case reports published between 1983 and 2004. The mean age was 55.2 years, and the male-to-female ratio was 1.9:1. There were more metastases in the jawbone than in oral soft tissues. The lung was the most common primary site for jawbone metastases, whereas the liver was for those of oral soft tissues. In contrast to reports in Western literature of the breast being the most common primary site, the liver was the most common primary site, followed by the lung and thyroid. These differences may be caused by a relatively high incidence rate of hepatocellular carcinoma in Korea.

Adult↗

PubMed2006

Apoptosis of oral epithelial cells in oral lichen planus caused by upregulation of BMP-4.

BACKGROUND: Bone morphogenic protein (BMP-4) is a member of transforming growth factor (TGF-beta) family and involved in various functions including apoptosis during neural ectoderm development. The objective of this study is to determine whether BMP-4 is involved in apoptosis, one characteristic, of human oral lichen planus (OLP). METHODS: Immunohistochemistry and in situ hybridization for BMP-4 were carried out in OLP (n = 21) and normal human oral mucosa (NOM, n = 31). Five tissue samples from NOM and OLP were underwent reverse transcriptase-polymerase chain reaction (RT-PCR). In vitro organ culture of oral mucosa was carried out with beads soaked with various concentration of BMP-4 (0.1, 1, and 10 microg/ml). The samples from in vitro organ culture were undergone haematoxylin and eosin staining, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labelling technique (TUNEL) assay, and immunohistochemical study with p53, matrix metalloproteinases (MMP)-1, and MMP-3. Involucrin expression was determined by western blot analysis after treatment with BMP-4 or TGF-beta1 on human oral keratinocytes. RESULTS: In immunohistochemical analysis, expression of BMP-4 was higher in OLP than NOM. BMP-4 mRNA expression was also detected in epithelial cells of both NOM and OLP together with underlying T-lymphocytes by in situ hybridization and RT-PCR. In oral mucosa organ culture, BMP-4 soaked beads induced apoptosis of epithelial cells. Acantolysis combined with apoptosis in oral epithelium was observed at 1 microg/ml of BMP-4 beads and it was due in part to the induction of p53 and MMP-1. Even MMP-3 induction was found in lower concentration of BMP-4 (0.1 and 1 microg/ml). Moreover, the expression of MMP-1 and MMP-3 was also observed in OLP. Recombinant BMP-4 or TGF-beta1 increased involucrin expression in human oral keratinocytes cell line. CONCLUSIONS: Expression of BMP-4 of epithelial cells was higher in OLP than NOM. High concentration of BMP-4 caused an apoptosis of oral epithelial cells in oral mucosa organ culture. Therefore, over-expression of BMP-4 is one causing factor for apoptosis of oral epithelial cells through upregulation of p53, MMP1 and MMP3 in OLP.

Adult↗

PubMed2005

Neural correlates of encoding and expression in implicit sequence learning.

In the domain of motor learning it has been difficult to separate the neural substrate of encoding from that of change in performance. Consequently, it has not been clear whether motor effector areas participate in learning or merely modulate changes in performance. Here, using a variant of the serial reaction time task that dissociated these two factors, we report that encoding during procedural motor learning does engage cortical motor areas and can be characterized by distinct early and late encoding phases. The highest correlation between activation and subsequent changes in motor performance was seen in the motor cortex during early encoding, and in the basal ganglia during the late encoding phase. Our results show that rapid encoding during procedural motor learning involves several distinct processes, and is represented primarily within motor system structures.

Adult↗

PubMed2005

Harvesting of Spirulina platensis by cellular flotation and growth stage determination.

AIM: To investigate an effective harvesting method for Spirulina platensis. METHODS AND RESULTS: Eighty per cent of S. platensis cells in the logarithmic growth phase were harvested by flotation when the cells were set in a static condition for 2 h. The optimum harvesting time was about day 6 of cultivation. The flotation activity of S. platensis cells was enhanced by the addition of NaCl. CONCLUSIONS: The harvesting of S. platensis by flotation is a cost-effective and straightforward method that can retain the algal quality. The optimum harvesting time of S. platensis can be predicted by the cellular protein to carbon ratio. SIGNIFICANCE AND IMPACT OF THE STUDY: Flotation harvesting is also applicable to other cyanobacteria with gas vesicles.

Bacteriological Techniques↗

PubMed2004

Nevoid basal cell carcinoma syndrome: a retrospective analysis of 33 affected Korean individuals.

This article describes a pooled analysis of Korean individuals with nevoid basal cell carcinoma syndrome (NBCCS). The data upon which this review is based has been retrieved from published case reports in Korean dental and medical literature between the years 1981 to 2002. We found 33 subjects who met the diagnostic criteria for NBCCS. Relative frequencies of associated complications are presented and compared with those of the English literature. Odontogenic keratocyst (OKC) and palmar and/or plantar pits, and hypertelorism were the most frequently observed anomalies. OKCs are often the first signs of NBCCS and can be detected in patients younger than 20 years of age. However, the incidence and clinical manifestations of NBCCS in Korean individuals were found to be rather different from those of other countries. The relatively low frequency of basal cell carcinomas and falx calcification among the major criteria were two major differences. The frequencies of the minor criteria concur in general with the ranges given by some others. It is concluded that these differences may be attributed to genetic and geographic differences.

Adolescent↗

PubMed2004

The expression of NMDA receptor 1 is associated with clinicopathological parameters and prognosis in the oral squamous cell carcinoma.

BACKGROUND: Glutamate activates the N-methyl-d-aspartate (NMDA) receptors and this receptor is involved in the proliferation and migration of various tumour cells in vitro. However, the relationship between NMDA receptor expression and clinical parameters in cancer patients is unclear. Therefore, NMDA receptor 1 (NMDAR1) expression along with its clinical significance was examined in patients with oral squamous cell carcinoma (OSCC). METHODS: Eighty-one tumour specimens from OSCC patients were used to determine the NMDAR1 expression level by immunohistochemical staining. The control was obtained from a matched normal adjacent mucosa. The cases were considered to be positive if reactivity was displayed in >25% of the cells. RESULTS: The NMDAR1 reactivity was positive in 50 of 81 cases, while it was negative in the control. NMDAR1 expression was significantly associated with a lymph node metastasis (P = 0.008), the tumour size (P < 0.001), and the cancer stage (P = 0.034). The patients whose tumours expressed NMDAR1 had a significantly poorer survival than the patients who were NMDAR1-negative (log-rank = 6.45, d.f. = 1, P = 0.011). CONCLUSIONS: The NMDAR1 overexpression was significantly associated with the prognosis-related factors. Therefore, it might be one of the prognostic markers of OSCC.

Aged↗

PubMed2002

Cerebellum activation associated with performance change but not motor learning.

The issue of whether the cerebellum contributes to motor skill learning is controversial, principally because of the difficulty of separating the effects of motor learning from changes in performance. We performed a functional magnetic resonance imaging investigation during an implicit, motor sequence-learning task that was designed to separate these two processes. During the sequence-encoding phase, human participants performed a concurrent distractor task that served to suppress the performance changes associated with learning. Upon removal of the distractor, participants showed evidence of having learned. No cerebellar activation was associated with the learning phase, despite extensive involvement of other cortical and subcortical regions. There was, however, significant cerebellar activation during the expression of learning; thus, the cerebellum does not contribute to learning of the motor skill itself but is engaged primarily in the modification of performance.

Brain↗