Synthesis and evaluation of PDLs22 recombinant protein / 대한치주과학회지

Periodontal ligament (PDL) is the connective tissue located between the tooth root and alveolar bone. In a previous study, PDLs22 was isolated as a PDL-specific gene by using subtractive hybridization between cultured PDL fibroblasts and gingival fibroblasts. It was also suggested that PDLs22 plays important roles in the development, differentiation and maintenance of periodontal tissues. However, little is known about functional study of PDLs22 using recombinant protein in PDL fibroblast differentiation and periodontium formation. In this study, in order to produce the PDLs22 recombinat protein, PDLs22-expression vector were constructed and expressed its protein in various host cell and temperature conditions. The results were as follows: 1. PDLs22 protein was not strongly expressed in the induction system using pRSET-PDLs22 construct. 2. When the BL21(DE3) pLysS was used as a expression host, PDLS22 protein was strongly expressed in the induction system using pHCEIIBNd-PDLs22 construct. 3. The PDLs22 protein was recognized at a molecular weight of 28 kDa in western blots. 4. Almost of the expressed PDLs22 protein was not soluble and observed like as inclusion body. 5. The protein solubility was not improved after modification of induction time and temperature during PDLs22 protein production. In this study, the system for the PDLs22 protein production was connstructed. However, the results suggest that further studies will be needed to produce the considerable amount of PDLs22 recombinat protein, which can use for the periodontal regeneration.

Molecular Genetic Analysis of Dystrophin Gene in Duchenne/Becker Muscular Dystrophy / 대한소아신경학회지

PURPOSE: Duchenne/Becker muscular dystrophy(DMD/BMD) is an X-linked recessive disorder caused by mutations of dystrophin genes. The purpose of the present study is to determine the frequency and the patterns of dystrophin gene deletions and to investigate the correlation of genotypes and phenotypes. METHODS: There were included a total of 89 children(88 boys and 1 girl) diagnosed as DMD/BMD by immunohistochemistry and/or genetic analysis from 1999 to 2003 at Seoul National University Children's Hospital. We analyzed the genomic DNA by multiplex PCR using a 26 dystrophin exon primer set. Direct sequencing was performed on 23 exons(in which point mutations were detected in other previous reports) in 22 patients without deletions. Phenotype and genotype relationship analysis was performed on the basis of retrospective clinical reviews. RESULTS: The frequency of dysmorphin gene deletions was 54%(32/59), which is lower than that of European and American data. Exon deletions were detected in 59 cases and the deletion "hot spots" were exon 44-54 constituting 80% of all deletions. In 6 cases without detectable deletions, 6 point mutaions(3 nonsense mutations and 3 nucleotide variants) were detected. The patients whose deletions were in the central parts or the patients with multiple exon deletions tended to show earlier symptom onsets and more rapid progressions of weakness but there were no statistical significances. CONCLUSION: Since deletions in dystrophin genes were detected in about 50% of the patients, studies on dystrophin protein expressions using muscle biopsy samples must be done for correct diagnosis.

Molecular Genetic Analysis of Dystrophin Gene in Duchenne/Becker Muscular Dystrophy / 대한소아신경학회지

PURPOSE: Duchenne/Becker muscular dystrophy(DMD/BMD) is an X-linked recessive disorder caused by mutations of dystrophin genes. The purpose of the present study is to determine the frequency and the patterns of dystrophin gene deletions and to investigate the correlation of genotypes and phenotypes. METHODS: There were included a total of 89 children(88 boys and 1 girl) diagnosed as DMD/BMD by immunohistochemistry and/or genetic analysis from 1999 to 2003 at Seoul National University Children's Hospital. We analyzed the genomic DNA by multiplex PCR using a 26 dystrophin exon primer set. Direct sequencing was performed on 23 exons(in which point mutations were detected in other previous reports) in 22 patients without deletions. Phenotype and genotype relationship analysis was performed on the basis of retrospective clinical reviews. RESULTS: The frequency of dysmorphin gene deletions was 54%(32/59), which is lower than that of European and American data. Exon deletions were detected in 59 cases and the deletion "hot spots" were exon 44-54 constituting 80% of all deletions. In 6 cases without detectable deletions, 6 point mutaions(3 nonsense mutations and 3 nucleotide variants) were detected. The patients whose deletions were in the central parts or the patients with multiple exon deletions tended to show earlier symptom onsets and more rapid progressions of weakness but there were no statistical significances. CONCLUSION: Since deletions in dystrophin genes were detected in about 50% of the patients, studies on dystrophin protein expressions using muscle biopsy samples must be done for correct diagnosis.

Risk Factors Related to Progression to Threshold Retinopathy of Prematurity in Extremely Premature Infants

PURPOSE: This study was intended to evaluate the risk factors related to the progression to threshold retinopathy of prematurity(ROP) after the first diagnosis of ROP in extremely premature infants. METHODS: We retrospectively reviewed the medical records of 41 infants with gestational ages of less than 28 weeks and birth weight of less than 1,250 g who took ophtalmologic examination for ROP during admission to NICU from January 1997 to December 2001. The infants who were diagnosed as ROP were classified into two groups the group that progressed to threshold ROP ("threshold ROP group", n=15) and the self-regressed prethreshold ROP group("prethreshold ROP group", n=18). We compared the risk factors and the changes of daily transcutaneous oxygen saturation during the two weeks after the first diagnosis of ROP between these two groups. RESULTS: Thirty three(80.5%) of 41 infants developed ROP. Fifteen(36.6%) progressed to threshold ROP after the diagnosis of ROP. The incidences of threshold ROP increased according to the lower birth weight in extremely premature infants. The progression to threshold ROP after the first diagnosis of ROP was significantly associated with the number of transfusions and birth weight(P<0.05, P<0.05, respectively). Daily mean arterial oxygen saturations of infants with threshold ROP during two weeks after the first diagnosis of ROP were higher than those of infants with prethreshold ROP(P<0.05). CONCLUSION: The occurrences of threshold ROP were related to lower birth weight and more frequent transfusions and higher daily mean transcutaneous oxygen saturation during two weeks after the first diagnosis of ROP.

Atypical Kawasaki Disease Presented with Toxic Shock Syndrome

Toxic shock syndrome(TSS) is clinically similar to Kawasaki disease(KD) in that both of them are characterized by fever, desquamating rash and mucous membrane erythema. In contrast the main feature of TSS is hypotension, whereas the complication of KD is coronary vasculitis. We report an 8-year-old boy who fulfilled the crireria for TSS and KD. Initially he showed clinical features of TSS, so he was treated with intravenous antibiotics and supportive management. But the fever sustained, and the coronary aneurysm that is the main complication of Kawasaki disease was shown by echocardiogram on Day 14. He was treated with intravenous immunoglobulin twice and the fever subsided and general condition was improved.

A Case of X-Linked Agammaglobulinemia Associated with Severe Neutropenia / 소아알레르기및호흡기학회지

X-linked agammaglobulinemia(XLA) is characterized by markedly reduced number of B lymphocytes, panhypogammaglobulinemia, recurrent bacterial infections in the first few years of life because of genetic defect for Bruton's tyrosine kinase at Xq22 region. Although XLA is a typical humoral immunodeficiency disease, severe neutropenia is sometimes presented in acute infection phase. We report a 23-month-boy with XLA who presented prolonged pneumonia, severe neutropenia over one month and profound panhypogammaglobulinemia. As his pneumonia improved, neutropenia subsided, but panhypogammaglobulinemia sustained. He was confirmed to have a point mutation in Btk-gene by direct-sequencing of Btk-gene.