• Title/Summary/Keyword: 고대 DNA

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Characterization of a bacterium isolated from diseased rock sea bream, Oplegnathus fasciatus, during low water temperature season in Jeju island (저수온기의 제주도 양식 돌돔, Oplegnathus fasciatus, 병어로부터 분리한 병원세균의 특성)

  • Go, Dae-Hui;Jin, Chang-Nam;Lee, Chang-Hun;Park, Geun-Tae;Heo, Mun-Su
    • Journal of fish pathology
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    • v.17 no.2
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    • pp.83-90
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    • 2004
  • The outbreak of haemorrhagic specticemia and lesions in dermis, frequently associated with keratitis have occured on rock sea bream (Oplegnathus fasciatus) reared in Jeju island. A bacterium isolated from the diseased fish identified as Pseudomonas sp. by morphologic, cultural, and biochemical tests. The bacterium was identified Pseudomonas anguilliseptica according to 16S rDNA sequence analysis. The highest growth rate of this strain was obtained at 20 to $\25^circ{C}$ although the disease occurred mostly below $16^\circ{C}$. The challenge test by ip injection revealed that this bacterium was pathogenic to rock sea bream. All experimental fish in challenged by ip injection died within 21 days but there was no death in control group. The bacterium was sensitive to Doxycycline, Chloramphenicol, Ciprofloxacin, Erythromycin, Flumequine, Nalidixic acid, Norfloxacin, and Ofloxacin.

Human Y Chromosome: Structure, Function and Evolution (인간 Y 염색체: 구조, 기능 그리고 진화)

  • 홍경원;허재원;김희수
    • Journal of Life Science
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    • v.13 no.6
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    • pp.958-969
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    • 2003
  • The human Y chromosome is strictly paternally inherited and does not X-Y crossing over during male meiosis in most of its length. Although this region came to be known as the non-recombining region Y (NRY), it was renamed as male-specific region Y (MSY) due to abundant recombination. The MSY is a mosaic of heterochromatic sequences and three classes of euchromatic sequences: X-transposed, X-degenerated and ampliconic. The X-transposed sequences exhibit 99% identity to the X chromosomal sequences. The X-degenerate sequences are remnants of ancient autosomes from which the modem X and Y chromosomes evolved. Eight palindromes of the ampliconic comprise one-quarter of the euchromatic DNA of the male-specific region of the human Y chromosome. They contain many testis-specific genes and typically exhibit 99.97% intra-palindromic (arm-to-arm) sequence identity. The arms of these palindromes must have subsequently engaged in gene conversion, driving the pair arms to evolve it concert. Averages of approximately 600 nucleotides per newborn male have undergone Y-Y gene conversion, which has had an important role in the evolution of multi-copy testis gene families in the MSY.

Therapeutic Efficacy of Lamivudine in Children and Adolescents with Chronic Hepatitis B (만성 B형 간염 소아청소년 환자에서의 라미부딘 치료 효과)

  • Choi, Yujung;Bae, Kil Seoung;Kim, Ki Hwan;Koh, Dae Kyun;Kim, Jong-Hyun
    • Pediatric Infection and Vaccine
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    • v.25 no.2
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    • pp.72-81
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    • 2018
  • Purpose: This prospective study aimed to investigate the therapeutic efficacy of lamivudine in children with chronic hepatitis B virus (HBV) infection. Methods: During July 2003 through October 2015, children with chronic hepatitis B who visited our institution were included in this study. Fifty-five patients, who received first-line treatment of lamivudine (3 mg/kg, 100 mg maximum) for over three months, were enrolled. After initiating lamivudine, alanine aminotransferase (ALT), HBV-DNA, and HBV markers were followed up at 1 month, 3 months, and every 3 months, thereafter. The treatment endpoint was determined as 1) normalization of ALT, 2) HBeAg seroconversion, and 3) anti-HBe positivity for twelve consecutive months. Results: Thirty-one male (56.4%) and 24 female (43.6%) patients were included. The mean age at treatment initiation was 8.1 years. The mean duration of treatment was 23.4 months. ALT normalization was found in 98.2% (54 of 55). Anti-HBe seroconversion was found in 70.6% (36/51). Loss of HBsAg was found in 10.9% (6/55). All biochemical responses occurred under age seven. The rate of virologic response (defined as HBV-DNA <2,000 IU/mL) at six months after treatment initiation was 78.7% (37/47). At twelve months after reaching treatment endpoint, 87.2% (34/39) maintained their virologic response. Resistance to lamivudine was found in 16.4% (9/55). Conclusions: Lamivudine treatment in Korean pediatric patients with chronic hepatitis B showed better outcomes compared with other studies that implemented similar protocols in foreign populations. Further studies are needed to investigate the efficacy of newly recommended antiviral drugs on the Korean pediatric population.