Estrogenic activity of zinc pyrithione: an in vivo and in vitro study

Zinc pyrithione (ZP) is commonly used to prevent dandruff and seborrheic dermatitis. Many consumers are exposed daily to high doses of ZP, causing serious concerns about its toxicity. The reproductive and developmental toxicities were previously reported in pregnant rats. However, the estrogenic activity of ZP at varying degrees of exposure has been rarely studied. Thus, we performed an uterotrophic assay, E-screen assay, and gene expression profiling to assess the estrogenic activity of ZP. For the uterotrophic assay, ZP (2, 10, or 50 mg/kg/d) was subcutaneously administered to ovariectomized rats every day for three days. Uteri were extracted 24 hours after the last dose. Then, wet and blotted uterine weights were measured. For the E-screen essay, MCF-7 cells (a breast cancer cell line) were exposed to 10⁻⁹ to 10⁻⁶ M of ZP, and cell proliferation was then measured. For the gene expression analysis, changes of gene expression levels in uterine samples taken for the uterotrophic assay were analyzed. In the uterotrophic assay, the concentration of ZP had no significant effect on uterine weight. In the E-screen assay, ZP at any concentration showed no significant increase in MCF-7 cell proliferation, compared to the control group. However, 10⁻⁶ M of ZP significantly reduced cell viability. The changes in gene expression slightly differed between the ZP and control groups. The in vivo and in vitro assays, together with gene expression analysis, demonstrated that ZP showed no significant estrogenic activity.

Estrogenic activity of zinc pyrithione: an in vivo and in vitro study

Zinc pyrithione (ZP) is commonly used to prevent dandruff and seborrheic dermatitis. Many consumers are exposed daily to high doses of ZP, causing serious concerns about its toxicity. The reproductive and developmental toxicities were previously reported in pregnant rats. However, the estrogenic activity of ZP at varying degrees of exposure has been rarely studied. Thus, we performed an uterotrophic assay, E-screen assay, and gene expression profiling to assess the estrogenic activity of ZP. For the uterotrophic assay, ZP (2, 10, or 50 mg/kg/d) was subcutaneously administered to ovariectomized rats every day for three days. Uteri were extracted 24 hours after the last dose. Then, wet and blotted uterine weights were measured. For the E-screen essay, MCF-7 cells (a breast cancer cell line) were exposed to 10⁻⁹ to 10⁻⁶ M of ZP, and cell proliferation was then measured. For the gene expression analysis, changes of gene expression levels in uterine samples taken for the uterotrophic assay were analyzed. In the uterotrophic assay, the concentration of ZP had no significant effect on uterine weight. In the E-screen assay, ZP at any concentration showed no significant increase in MCF-7 cell proliferation, compared to the control group. However, 10⁻⁶ M of ZP significantly reduced cell viability. The changes in gene expression slightly differed between the ZP and control groups. The in vivo and in vitro assays, together with gene expression analysis, demonstrated that ZP showed no significant estrogenic activity.

Association of Polymorphisms in the Vitamin D Receptor Promoter with Idiopathic Short Stature

The genetic alterations of vitamin D receptor (VDR) are related with the growth of long bone. There were a lot of reports regarding an association of polymorphisms in the VDR promoter with many disorders, but not with idiopathic short stature (ISS). We investigated the association of them with ISS. A total of 50 subjects, including 29 ISS patients and 21 healthy controls with their heights within the normal range was recruited. We selected two single nucleotide polymorphisms (SNPs) from VDR promoter (rs11568820 at the Cdx-2 binding site upstream of exon 1e and rs4516035 at -1012 upstream of exon 1a) as candidates, respectively. In genotype analysis, the frequency of A/A genotype at the Cdx-2 binding site locus (rs11568820) upstream of exon 1e of VDR was decreased to 6.9% in ISS patients (28.6% in controls) (P = 0.027). The genetic variation at the Cdx-2 binding site of VDR promoter can be a contributing factor of growth of height.

Expression Patterns of Ki-67, Cyclin A, and Cyclin D1 during Tooth Development / 체질인류학회지

Dental epithelial and mesenchymal cells that form the teeth undergo dynamic changes in cell cycle during tooth development and morphogenesis. Although proliferation has been known as a key event during odontogenesis, the cell cycle phases and their relations with the complicated molecular mechanisms of tooth development are not fully understood yet. This study comparatively examined the expression patterns of Ki-67, cyclin A, and cyclin D1 during tooth development in the mouse incisor and molar in order to identify the cell-cycle characteristics during odontogenesis. We found that Ki-67 and cyclin A were expressed in the proliferating cells in the dental epithelial and mesenchymal tissues at the bud, cap and bell stages. Cycln D1 showed distinct expression in the incisor odontoblast region and the enamel knot, in which Ki-67 nor cyclin A was expressed. Our results provide specific information on the cell cycle phases during tooth development that may provide clues to relate them with the complex odontogenic mechanisms. Furthermore, we suggest that our findings enlightened the previous studies on the incisor odontoblasts and the enamel knot during tooth development.

Erratum: Correction of Nomenclature of Mutations

In the abstract, case description and figure 2, the nomenclature of two mutations was misprinted because of misreading the cDNA nucleotide sequences.

Novel Compound Heterozygous Mutations in the Vitamin D Receptor Gene in a Korean Girl with Hereditary Vitamin D Resistant Rickets

Hereditary vitamin D resistant rickets (HVDRR) is a rare genetic disorder caused by a mutation of vitamin D receptor (VDR) gene. A number of cases had been reported in many countries but not in Korea. We examined a three-year old Korean girl who had the typical clinical features of HVDRR including rickets, hypocalcemia, hypophosphatemia, elevated serum calcitriol level and secondary hyperparathyroidism. The girl and her father were both heterozygous for the 719 C-to-T (I146T) mutation in exon 4, whereas she and her mother were both heterozygous for 754 C-to-T (R154C) mutation in exon 5 of the VDR gene. In this familial study, we concluded that the girl had compound heterozygous mutations in her VDR gene which caused HVDRR. This is the first report of a unique mutation in the VDR gene in Korea.

Plaque Rupture is a Determinant of Vascular Events in Carotid Artery Atherosclerotic Disease: Involvement of Matrix Metalloproteinases 2 and 9

BACKGROUND AND PURPOSE: Unstable carotid atherosclerotic plaques are characterized by cap rupture, leading to thromboembolism and stroke. Matrix metalloproteinases (MMPs) have been implicated in the progression of atherosclerosis and plaque rupture. The aim of this study was to assess the relationship between the expressions of MMP-2 and MMP-9 and carotid plaque instability. METHODS: Eighty atherosclerotic plaques were collected from 74 patients undergoing carotid endarterectomy. Clinical information was obtained from each patient, and plaque morphology was examined at the macroscopic and microscopic levels. The immunohistochemical expressions of MMPs were graded using semiquantitative scales. RESULTS: Macroscopic ulceration (84.6% versus 63.4%, p=0.042) and microscopic cap rupture (79.5% versus 51.2%, p=0.010) were more common in symptomatic than in asymptomatic patients. Immunoreactivities of MMP-2 and MMP-9 were increased in 40 and 36 atheromatous plaques, respectively. Macroscopic ulceration was strongly correlated with the expressions of MMP-2 (p<0.001) and MMP-9 (p=0.001). There were significant correlations between increased MMP-2 expression and cap rupture (p=0.002), intraplaque hemorrhage (p=0.039), and a thin fibrous cap (p=0.002), and between increased MMP-9 expression and cap rupture (p=0.010) and a large lipid core (p=0.013). CONCLUSIONS: Plaque rupture was significantly associated with the development of vascular events in carotid atherosclerotic disease. MMP-2 and MMP-9 are strongly correlated with plaque instability.

Baicalein protects HT22 murine hippocampal neuronal cells against endoplasmic reticulum stress-induced apoptosis through inhibition of reactive oxygen species production and CHOP induction

Baicalein is one of the major flavonoids in Scutellaria baicalensis Georgi and possesses various effects, including cytoprotection and anti-inflammation. Because endoplasmic reticulum (ER) stress has been implicated in neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and cerebral ischemia, we investigated the effects of baicalein on apoptotic death of HT22 mouse hippocampal neuronal cells induced by thapsigargin (TG) and brefeldin A (BFA), two representative ER stress inducers. Apoptosis, reactive oxygen species (ROS) production, and mitochondrial membrane potential (MMP) were measured by flow cytometry. Expression level and phosphorylation status of ER stress-associated proteins and activation and cleavage of apoptosis-associated proteins were analyzed by Western blot. Baicalein reduced TG- and BFA-induced apoptosis of HT22 cells and activation and cleavage of apoptosis-associated proteins, such as caspase-12 and -3 and poly(ADP-ribose) polymerase. Baicalein also reduced the TG- and BFA-induced expression of ER stress-associated proteins, including C/EBP homologous protein (CHOP) and glucose-regulated protein 78, the cleavage of X-box binding protein-1 and activating transcription factor 6alpha, and the phosphorylation of eukaryotic initiation factor-2alpha and mitogen-activated protein kinases, such as p38, JNK, and ERK. Knock-down of CHOP expression by siRNA transfection and specific inhibitors of p38 (SB203580), JNK (SP600125), and ERK (PD98059) as well as anti-oxidant (N-acetylcysteine) reduced TG- or BFA-induced cell death. Baicalein also reduced TG- and BFA-induced ROS accumulation and MMP reduction. Taken together, these results suggest that baicalein could protect HT22 neuronal cells against ER stress-induced apoptosis by reducing CHOP induction as well as ROS accumulation and mitochondrial damage.

Prevalence of BRCA1 and BRCA2 Mutations in Korean Breast Cancer Patients

The incidence of breast cancer in Korea has been increasing in recent years, such that it is now the most common female cancer. Breast cancer in Korea is characterized by an earlier age of onset than in Western countries, suggesting that it would be related with genetic background. We assayed germline mutations in the BRCA genes to evaluate their genetic pathology in Korean breast cancer patients. The study subjects consisted of 173 patients at clinically higher risk and 109 unselected patients. Germline mutations in the entire coding sequences of the BRCA1 and BRCA2 genes were analyzed by Conformation-Sensitive Gel Electrophoresis (CSGE), and any aberrantly-sized band was sequenced. BRCA mutations were present in 12.7% of the high risk patients, compared with 2.8% of the unselected patients. Among high risk patients, mutations were most prevalent in patients with a family history of breast or first-degree ovarian cancer (22.1%), followed by those with male breast cancer (20%), bilateral breast cancer (20%), multiple organ cancer including breast (13%) and younger breast cancer patients (aged<35 yr) (8.1%). Moreover, BRCA mutations were detected in 34.8% of patients having two highrisk factors. These findings suggest that BRCA gene mutation analysis should be performed on Korean patients with high-risk factors for breast cancer.

No Association between Genetic Polymorphism of Tryptophan Hydroxylase A218C and Serotonin Transporter Linked Polymorphic Region and Panic Disorder

OBJECTIVES: Genetic variations of the tryptophan hydroxylase(TPH) gene and the serotonin transporter linked polymorphic region(5-HTTLPR) polymorphism have been associated with its functional capacity. The authors investigated whether the allelic constitution of the TPH gene and 5-HTTLPR are associated in Korean panic patients. METHODS: 244 Korean patients with panic disorder and 227 normal healthy controls were tested for a genetic polymorphism of TPH A218C and 5-HTTLPR polymorphism. To assess the severity of panic disorder during the last one month, anticipatory anxiety, panic difficulty, panic distress, agoraphobic difficulty and agoraphobic distress were measured with visual analogue scale(VAS) score, STAI-S & T, BDI, SCL-90-R, ASI-R, CGI, PDSS, and HAMD. RESULTS: There was no significant difference in genotype and allele frequencies of TPH A218C and 5-HTTLPR polymorphism between panic patients and controls. Although we observed some differences in genotype and allele frequencies of TPH A218C polymorphism among male subjects, these differences disappeared after Bonferroni correction. And there were no significant differences in clinical variables. CONCLUSION: Our results suggested that there are no association between the genetic polymorphism of TPH gene and 5-HTTLPR with panic disorder.

Genetic Association between Single Nucleotide Polymorphisms on COMT Gene and Schizophrenia in Korean Population / 대한정신약물학회지

OBJECTIVE: This study aimed to explore genetic relation between schizophrenia and COMT gene which plays an important role in metabolizing dopamine, one of the most intriguing neuro-transmitters for schizophrenia. METHODS: 1) Single Nucleotide Polymorphism (SNP) on exons of COMT gene was searched by F-CSGE (Fluorescent-Conformation Sensitive Gel Electrophoresis) method with 50 patients with schizophrenia to look for any SNP unique to Korean patients with schizophrenia. 2) Genotyping was done for five SNPs on COMT gene for 218 patients with schizophrenia and 199 normal controls by SNaPShot method. Allele frequencies, genotype frequencies and simulated haplotype frequencies were compared between patients with schizophrenia and normal controls. RESULTS: 1) No unique SNPs for Koreans was found on exons of COMT gene and seven SNPs were found, all of them are already reported to be found in other ethnic groups. 2) No significant difference between patients with schizophrenia and normal controls in terms of allele frequencies, genotype frequencies and haplotype frequencies was found in our sample. CONCLUSION: Genetic association between five SNPs on COMT gene and DSM-IV diagnosis of schizophrenia among Koreans was not able to be found in this study.

p53 Mutation and Epidermal Growth Factor Receptor Overexpression in Glioblastoma

Recent molecular studies indicate two different genetic pathways leading to the development of glioblastoma; final progression of astrocytoma and de novo formation. To define the mutual relationships of cytogenetic changes in the pathogenesis of glioblastoma, molecular histopathologic alterations of p53 and epidermal growth factor receptor (EGFR) were evaluated by single stranded conformational polymorphion, reverse transcriptase-polymerase chain reaction and immunohistochemical stains in 15 primary and 21 secondary glioblastomas. Mutations in p53 gene and positive immunoreactivity to p53 protein (DO1) were more prevalent in secondary glioblastomas than in primary glioblastomas. A correlation between p53 mutations and p53 immunopositivities in glioblastomas was observed in 83.3% of the cases. All cases with positive p53 immunoreactivities showed p53 mutations; however, 13.9% of glioblastomas with p53 immuno-positivities lacked the relevant mutations. EGFR amplifications were detected in 73.3% of primary glioblastomas and 9.5% of secondary glioblastomas (p<0.001). The concurrence of p53 mutation and EGFR amplification was revealed in only 2 out of 15 primary glioblastomas and none among the secondary glioblastomas. Immunoreactivities for EGFR were noted in 66.7% of primary glioblastomas and in 9.5% of secondary glioblastomas (p<0.001). A correlation between EGFR amplification and EGFR immunopositivity in glioblastomas was observed in 91.7% of the cases. These data indicate that EGFR amplification and p53 mutations are two independent genetic events in the development of glioblastomas.

p53 Mutations in Advanced Supraglottic Cancer / 대한방사선종양학회지

PURPOSE: To determine the prognostic significance of p53 mutations in advanced supraglottic cancer patients. MATERIALS AND METHODS: Twenty-six patients with pertinent tissue materials among 60 patients diagnosed as advanced supraglottic cancer in Kyung Hee university hospital and received total or partial laryngectomy followed by radiation therapy were enrolled. Immunohistochemical staining using DO7 monoclonal antibody was performed. Tumor specimens were analyzed for p53 mutations in exons 5 through 8 by using PCR-SSCP analysis followed by DNA sequencing of all variants. RESULTS: p53 mutations were present in 8 cases among 26 patiets. Mutations within exon 5 were 3 cases, exon 6 were 4 cases, and exon 7 was 1 case. Mean survival time was 70.2 months in patients without mutations, 61.3 months with mutations but there was no statistically significant differences (p=0.596). Mutations were 25% in stage III and 36% in stage IV but there was no statistically significant differences (p=0.563). Mutations were 25% in lymph node negative group and 42% in lymph node positive group but there was no statistically significant differences (p=0.437). CONCLUSION: The presence of a p53 mutation detected by PCR-SSCP is not associated with survival, stage and lymph node status.

Association Study of Functional Catechol-O-Methyltransferase Gene Polymorphism in Korean Schizophrenia / 신경정신의학

OBJECTIVES: Catechol-O-methyltransferase(COMT) is involved in the degradation of catecholamine neurotransmitters and has been investigated as a candidate gene in schizophrenia. Recently, possible relationship between functional COMT gene polymorphism and schizophrenia has been suggested. To address the possible role of functional COMT gene polymorphism in the predisposition to schizophrenia, we carried out an association study in Korean schizophrenic patients and controls. METHODS: One hundred and three Korean inpatients diagnosed as schizophrenia and 103 age and sex matched controls were selected as study subjects. Patients were subgrouped into two groups on the basis of history of aggressive behavior, family history of schizophrenia and related disorders, and age at onset. We determined COMT genotypes using PCR of the relevant region followed by digestion with NlaIII and electrophoresis. RESULTS: No significant differences of allele and genotype frequencies were noted between patients and controls. However, when patients were categorized by the presence of family history of schizophrenia and related disorders, patients with family history showed almost 4-fold higher frequency of having COMT L allele containing genotype compared to controls(p=0.02, OR=3.9, 95% CI=1.10-14.33). CONCLUSION: Although our results do not support an association between functional polymorphism of COMT gene and schizophrenia overall, the findings suggest an association between functional COMT gene polymorphism and familial schizophrenia. Further studies with large samples are needed to confirm this association.

Analysis of the Three Dimensional Structure of Envelope Protein of the Japnes Encephalitis virus Isolated in Korea

Three dimensional structures of envelope protein from Korean isolates and Nakayama-NIH strain of Japanese encephalitis virus (JEV) were deduced by a computer program (HyperChem 4.0 Chemplus 1.0) based on the data of the three dimentional structure of Tick-borne encephalitis virus. In the three dimensional structure of envelope protein, neutralizing epitope and T-helper cell recognition site of C-terminal region of Korean isolates were structually similar to those of Nakayama-NIH but the N-terminal region was not. Korean JE isolates were compared with Nakayama-NIH strain by using cross-neutralization antibody test. Neutralizing activities of Korean isolates derived from guinea pigs were higher than those of Nakayama-NIH strain against Korean isolates, although the polyclonal antibody titers of Nakayama-NIH showed 1:160 to 1:640 against Korean isolates. According to the results from three dimentional structures and cross-neutralization analyses, the antigenic difference between Korean JE isolates and Nakayama-NIH strain may be dependent on structural difference of envelope protein.

The Status of Central Nervous System Tumors in Chonnam and Chonbuk Provinces

The authors analized statistically 635 cases of pathologically confirmed central nervous system tumors in the Chonnam and Chonbuk provinces from 1987 to 1989. The results were as follows ; 1) Of the 635 cases, 327 cases(51.5%) were male and 308 cases(48.5%) were female. 2) Intracranial tumors were 518 cases(81.6%), spine and intraspinal tumors 94(14.8%), scalp and skull tumors 23(3.6%). 3) Average incidence rate of tumors was 3.5/year/100,000 population, 3.1 for Chonnam province, 4.4 for Chonbuk province. 4) Among the brain tumors, glial tumors were the most common(28.4%), and followed by meningiomas(18%), pituitary tumors(15.2%), metastatic tumors(8.9%), Among the intraspinal tumors, neurinomas and neurofibromas were found most frequently(41.5%), and rests were metastatic tumors(23.4%), meningiomas(9.5%) in order. 5) Sexual predilection of tumors was as follows : male preponderance was noted for oligodendrogliomas(9:1), metastatic tumors(2.3:1), glioblastomas multiforme(GM)(1.8:1) cysticercosis(1.6:1), and female preponderance for meningiomas(1:3.2), pituitary tumors(1:2), paragonimiases(1:1.5). 6) The incidence rate of brain tumors in children below 15 years was 11.8% and that which occured infratentorially was 47.5%. 7) The brain tumors were found mainly in cerebral hemispheres, in which area most of tumors were meningiomas, astrocytomas in order. In sellar, parasellar most of tumors were meningiomas astrocytomas in order. In sellar, parasellar and suprasellar region, the majority of tumors were pituitary tumors and meningiomas. 8) Cysticercosis showed a predilection for the sixth and seventh decades, meningiomas, metastatic tumors, neurinomas for sixth decade, GM and supratentorial astrocytomas for fourth, fifth and sixth decades, oligodendroliomas for fifth decade, infratentorial astrocytomas, medulloblastomas and craniopharyngiomas for first and second decades. 9) In the spinal tumors, the favorable site was thoracic region and majority of them were located intradural extramedullarily and extradurally in similar incidence.