• Journal of the korean academy of Pediatric Dentistry
• /
• v.30 no.1
• /
• pp.171-180
• /
• 2003

The development of calvarial bones is tighly co-ordinated with the growth of the brain and needs of harmonious interactions between different tissues within the calvarial sutures. Premature fusion of cranial sutures, known as craniosynostosis, presumably involves disturbance of these interactions. Mutations in the homeobox-containg gene Msx2 cause human craniosynostosis syndrome. Msx genes, which are consist of Msx1, Msx2 and Msx3, are homeobox-containg transcripton factors, and were originally identified as homologue of Drosophila msh(muscle segment homeobox) gene. Msx1 and Msx2 genes, expressed mostly in overlapping patterns at multiple site of tissue interactions during vertebrate development, are associated with epithelial-mesenchymal interactions during organogenesis, targets of BMP and FGF signaling. To elucidate the function of Msx genes in the early morphogenesis of mouse cranial suture, we analyzed the expression of them by in situ hybridization during embryonic(E15-E18) stage, and did vivo experiments in E15.5 mouse using rhBMP-2, rhFGF-2 protein soaked bead. In the sagittal suture, Msx1 was expressed in the mesenchyme of suture and the dura mater, Msx2 was intensely expressed in the sutural mesenchyme and the dura mater. In the coronal suture both of Msx genes were expressed intensely in the sutural mesenchyme and expressed in the periosteum also. Msx1 had a broader expression pattern than Msx2. BMP2 beads induced expression of both Msx1 and Msx2, FGF2 beads induced expression of Msx1, but not Msx2. Taken together, these data suggest that Msx1 and Msx2 genes have important role in regulating the morphogenesis and maintenance of embryonic cranial suture. Both of Msx genes are expressed similarly but because of their upstream signaling, they function dependently or cooperatively according to change of signaling molecule.

• The korean journal of orthodontics
• /
• v.38 no.2
• /
• pp.133-143
• /
• 2008

Objective: This study was performed to identify the characteristics of the MSX1 gene (locus chromosome 4p16) in Korean nonsyndromic cleft lip and palate (CL/P), which is assumed to be a major candidate gene acting as a causal factor in nonsyndromic CL/P and missing teeth. Methods: The 36 individuals (23 males and 13 females) who had visited the department of orthodontics at from 1998 to 2002 and who had nonsyndromic CL/P were included in the study. Using a PCR-based assay, the MSX1 gene was amplified, sequenced, and searched for inferred protein products (Reference: Homo sapiens MSX1, accession number AF426432 and NP_002439). The common single nucleotide polymorph isms were observed. Results: In exon 1, nucleotide "A" of the 253 basepair (bp) region was substituted for "G", and in the 255 bp region, nucleotide "G" was inserted. In exon 2, nucleotide "C" of the 11 bp region was substituted for "A", and "T" or "G" was inserted into the 351 bp region whereas "T" or "A" was inserted into the 352 bp region. In protein analysis, "Thr85Ala" missense mutation was found. The "Thr85Ala" missense mutation in this study is different from those of studies using subjects of other races. Conclusions: The results suggest that there is specific mutation of MSX1 in Korean and it plays an important role in Korean nonsyndromic CL/P. However, any distinct genetic polymorphisms between CL/P with missing teeth in the cleft region and CL/P without missing teeth could not be found.

• Korean Journal of Microbiology
• /
• v.24 no.2
• /
• pp.113-118
• /
• 1986

Optimum temperature and pH of glutamine synthetase activity (E.C. 3.6.1.2.) of R. sphaeroides D-230 was $35^{\circ}C$ and 6.8, respectively. The adenylated state of GS in R. sphaeroides D-230 was stabilized by addition of 0.2mg/ml of cethyltrimethylammoniumbromide. Valine, histidine, proline, isoleucine, and lysine were good nitrogen source for the growth of R. sphaeroides D-230. The growth of R. sphaeroides D-230 in $N_2,\;NaNO_3\;or\;NH_4Cl$ as sole nitrogen source was lower than in any otherculture conditions. GS activity was inhibited, more or less, by various amino acid. THe relative inhibition rate of the enzyme by added 7mM arginine, $NH_4Cl,\;N_2,\;and\;NaNO_3$ was 63.8%, 26.79%, 6.24%, and 10.64%, drespectively. THe hydrogen evolution of R. sphaeroides D-230 grown in N-limited media was inhibited by 0.1mM MSX, irreversible GS inhibitor. GS activity was completely inhibited by 1.0mM MSX but ammonia released maximally at the same concentration of MSX. Ammonia release by added MSX was increased up to 1.0mM MS, but decreased above 1.0mM MSX. It is probably due to inhibition of nitrogenase actixity by MSX. Nitrogenase activity was not inhibited at low concentration of MSX. These results suggests that the inhibition of nitrogenase activity by ammonia is mediated by products of ammonia assimilation rather than by ammonia itself.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.30 no.3
• /
• pp.391-405
• /
• 2003

Craniosynostosis, known as a premature fusion of cranial sutures, is a developmental disorder characterized by precocious differentiation and mineralization of osteoblasts in the calvarial sutures. Recent genetic studies have demonstrated that mutation in the homeobox gene Msx2 causes Boston-type human craniosynostosis. Additionally, the phenotype of Dlx5 homozygote mutant mouse presents craniofacial abnormalities including a delayed ossification of calvarial bone. Furthermore transcription of osteocalcin, a mature osteoblast marker, is reciprocally regulated by the homeodomain proteins Msx2 and Dlx5. These facts suggest important roles of osteocalcin, Msx2 and Dlx5 genes in the calvarial bone growth and suture morphogenesis. To elucidate the function of these molecules in the early morphogenesis of mouse cranial sutures, we have first analyzed by in situ hybridization the expression of osteocalcin, Msx2 and Dlx5 genes in the developing parietal bone and sagittal suture of mouse calvaria during the embryonic (E15-E18) stage. Osteocalcin mRNA was found in the periosteum of parietal bones from E15, and gradually more highly expressed with aging. Msx2 mRNA was intensely expressed in the sutural mesenchyme, osteogenic fronts and mildly expressed in the dura mater during the embryonic stage. Dlx5 mRNA was intensely expressed osteogenic fronts and the periostem of parietal bones. To further examine the upstream signaling molecules of transcription factor Msx2 and Dlx5, we have done in vitro experiments in E15.5 mouse calvarial explants. Interestingly, implantation of BMP2-, BMP4-soaked beads onto the osteogenic fronts after 48 hours organ culture induced etopic expressions of Msx2 and Dlx5 genes. On the other hand, overexpression of $TGF{\beta}1$, GDF-6, -7, FGF-2, -4 and Shh did not induce the expression of Msx2 and Dlx5. Taken together. these data indicate that transcription factor Msx2 and Dlx5 play critical roles in the calvarial bone and suture development, and that BMP siganling is involved in the osteogenesis of calvarial bones and the maintenance of cranial sutures through regulating these two transcriotpn factors. Furthermore, different expression patterns between Msx2 and Dlx5 suggest their specific functions in the osteoblast differentiation.

• 한국생물공학회:학술대회논문집
• /
• 2002.04a
• /
• pp.309-312
• /
• 2002

Exogenous glutamine synthetase (GS) was used efficiently as a selectable marker to identify successful transfectants for the production of erythropoietin (EPO) in Chines hamster ovary (CHO-K1) cells in the absence of glutamine. Inclusion of methionine sulphoximine (MSX), an inhibitor of glutamine synthetase, enabled further selection of clones with relatively high levels of transfected glutamine synthetase and EPO genes which were coupled together. In this study, a new cell line was established by using GS system and enhancement of EPO production by zinc ion was evaluated using the transfected CHO-K1 cell line under normal condition. It was found that EPO production from CHO-K1 cells was enhanced 40% when the optimal amount of zinc ion was added.

• The Bulletin of The Korean Astronomical Society
• /
• v.35 no.1
• /
• pp.60.2-60.2
• /
• 2010

We have studied the abundance ratio of HNC and HCN toward the Red MSX Sources (RMS) using HCN (J=1-0), HNC (J=1-0), $H^{13}CN$ (J=1-0), $HN^{13}C$ (J=1-0),and $N_2H^+$ (J=1-0) lines observed with the Mopra 22 m radio telescope. The RMS are massive young stellar objects identified by the MSX satellite data combined with the 2MASS data. HCN and HNC (a geometrical isomer of HCN) are among the most basic interstellar molecules. According to our analysis, the column density of HCN is found to be correlated with that of HNC. Additionally, the [HNC]/[HCN] abundance ratio is sensitive to the core temperature because HNC is depleted in high temperature regions. This result is consistent with the previous results seen in low mass starless or protostellar cores.

• 대한예방의학회:학술대회논문집
• /
• 2004.10a
• /
• pp.40.2-41
• /
• 2004

• BMB Reports
• /
• v.44 no.7
• /
• pp.478-483
• /
• 2011

Hairless (HR), a transcriptional cofactor, is highly expressed in the skin and brain. To characterize the effects of HR expression in the skin, we examined its capacity for transcriptional regulation of its target genes in mouse skin and keratinocytes. We found that Foxe1 mRNA expression was suppressed in HR-overexpressing skin, as well as in HR-expressing keratinocytes. In turn, Msx1 expression was downregulated contingent on Foxe1 downregulation in skin and keratinocytes. We also found that expression of Sfrp1 was also correlated with that of Foxe1. Further investigation of the mechanisms involved in the transcriptional regulation of these genes will facilitate our understanding of the relationship among genes involved in hair follicle morphogenesis and cycling.

• KSBB Journal
• /
• v.6 no.2
• /
• pp.181-187
• /
• 1991

Physiological and morphological characteristics of Anabaena azollae cells immobilized in a synthetic polymer, polyvinyl(PV), were investigated. The cell density of the non-immersed PV foam reached 4.4mg Chl/g dry wt. PV foam. This is 8 times higher than that of PV-immobiliz action in immersed batch system. And MSX-induced ammonia productivity and the photosynthectic oxygen evolution activity are higher than that of free cells after short-term dark storage. Nitrogenase activity and thermostability of photosynthetic activity are also higher than that of free Anabaena cells after immobilization. Total hydrogen production reached to 1.6ml $H_2$ per reactor (total 4mg Chl) after 6 days.

• Biomolecules & Therapeutics
• /
• v.6 no.2
• /
• pp.219-224
• /
• 1998

The bioequivalence of two clarithromvcin products was evaluated with 16 normal male volunteers (age 23-28 yr, body weight 57.5-75.517g) following single oral dose. Test product was ReYon Clarithromycin tablets (ReYon Pharm. Corp., Korea) and reference product was Klarici $d_{R}$ tablets (Abbott Korea). Both products contain 250 mg of clarithromucin. One tablet of the test or the reference product was administered to the volunteers, respectively, by randomized two period cross-over study (2$\times$2 Latin square method). The determination of clarithromycin was accomplished using a modified agar well diffusion bioassay. As a result of the assay validation, the quantification of clarithromycin in human serum by this technique was possible down to 0.03$\mu$g/ml using 100$\mu$l of serum. The coefficient of variation (C.V.) was less than 10%. Average drug concentrations at each sampling time and pharmacokinetic parameters calculated were not significantly different between two products P>0.05); the area under the curve to last sampling time (24 hr) (AU $Co_{24hr}$ (8.10$\pm$ 1.26 vs 8.22$\pm$ 1.627g . hr/ml), AUC from time zero to infinite (AU $Co_{\infty}$) (8.61 $\pm$ 1.28 vs 8.84$\pm$ 1.71 $\mu$g . hr/ml), maximum plasma concentration ( $C_{msx}$) (0.87$\pm$0.22 vs 0.88$\pm$0.19 $\mu$g/ml) and time to maximum plasma concentration ( $T_{max}$) (2.69 $\pm$0.48 vs 2.56$\pm$ 0.51 hr). The differences of mean AU $Co_{24h}$, $C_{msx}$ and $T_{msx}$ between the two products (1.44, 1.39, and 4.65%, respectively) were less than 20%. The power (1-$\beta$) and treatment difference ($\Delta$) for AU $Co_{24hr}$, and $C_{max}$ were more than 0.8 and less than 0.2, respectivly. Although the power for $T_{max}$ was under 0.8, $T_{max}$. of the two products was not significantly different each other (p>0.05). These results suggest that the bioavailability of ReYon Clarithromycin tablets is not significantly different from that of Klarici $d_{R}$ tablets. Therefore, two products are bioequivalent based on the current results. results.sults.sults.s.s.s.s.s.s.s.