Son-Il Pak

Prevalence of Human Astrovirus in Patients with Acute Gastroenteritis

The prevalence of human astroviruses was tested in patients with acute gastroenteritis by using conventional duplex reverse transcription (RT)-PCR and electrophoresis. Diarrheal fecal samples were collected from 9,597 patients at local hospitals in Seoul. The prevalence of astroviruses was 1.0% (94/9,597 patients; mostly infants), and that of sapoviruses was 0.1% (14/9,597 patients). Age- and gender-wise analyses were carried out on 29 astrovirus-positive patients having complete information on file regarding their age, gender, and other particulars. The results were higher in patients of ages 0 to 14 yr, and 69.0% of the astrovirus-positive patients were females, of which 69.2% were infants (0 to 12 months), and 61.5% were 1-4 yr old. Notably, in the case of 5 to 78-yr-old acute gastroenteritis patients, 100% were females.

Epidemiological Characterization of Respiratory Viruses Detected from Acute Respiratory Patients in Seoul

Background: Viruses that cause acute respiratory infection include adenovirus (ADV), respiratory syncytial virus A and B (RSV(A), RSV(B)), influenza virus A and B (FluA, FluB), parainfluenza virus 1, 2 and 3 (PIV1, PIV2, PIV3), human metapneumovirus (hMPV), human coronavirus (hCoV), human rhinovirus (hRV), and enterovirus, among others. Methods: Viral incidence was evaluated in acute respiratory patients in Seoul, Korea from 2010 to 2012. A total of 2,544 oropharyngeal swab specimens were tested by real-time polymerase chain reaction (PCR) methods. RNA viruses (hRV, PIV, RSV, hCoV, and hMPV) and DNA viruses (ADV and bocavirus) were detected using the one-step reverse transcriptase PCR (RT-PCR) premix kit (SolGent, Korea) from January 2010 to June 2011, and using the real-time PCR kit (Kogenebiotech, Korea) from July 2011 to December 2012. Results: Thirty-two percent (813/2,544) of specimens were positive; 31.9% (294/923) in 2010, 31.4% (232/ 738) in 2011, and 32.5% (287/883) in 2012. The most frequently isolated virus was hRV (40.7%, 331/813), followed by ADV (23.9%, 194/813), RSV (14.1%, 115/ 813), PIV (12.3%, 100/813), and hCoV (8.7%, 71/813). PIV1 was the most commonly isolated PIV, followed by PIV3 and PIV2, respectively. hCo OC43 was the most commonly isolated hCoV, followed by hCoV NL63 and hCoV 229E, respectively. Conclusion: Information on respiratory viruses circulating in Seoul, Korea over the last three years will be helpful in the management of acute respiratory infections, and for larger-scale epidemiological studies. (Ann Clin Microbiol 2013;16:188-195)

Epidemiological Characterization of Influenza Viruses detected from Acute Respiratory Patients in Seoul during 2010-2012

Objectives: For our survey of the incidence of influenza viruses among respiratory viral infections in Seoul, we evaluated their prevalence among infectious acute respiratory viral patients in Seoul from 2010 to 2012 through regular surveillance. Methods: For influenza virus detection, we conducted real-time PCR analyses on 2,544 throat specimens collected from patients with respiratory viral infections in Seoul between 2010 and 2012. They were collected and then tested for the presence of influenza viruses through reverse transcription (RT) - polymerase chain reaction (PCR). Results: 19.1% (486/2,544) of the throat specimens were determined to be positive for influenza viruses. The incidences of influenza viral infection in the case of respiratory viral infections through regular surveillance in Seoul were 23.0% (212/923) in 2010, 6.4% (47/738) in 2011, and 25.7% (227/883) in 2012, and 10.8% (275/2,544) of type A, and 8.3% (211/2,544) type B influenza viruses. In addition, the greatest prevalence was in the 20-49 age group (51.6% ), which shows that influenza viruses constituted a major causative agent of acute respiratory viral infections. Conclusions: The distributions of influenza viruses and the epidemiologic patterns of the viral pathogen in acute respiratory viral infectious patients may provide potentially effective data for epidemiological studies in Seoul, Korea.

Repeated injection of KMRC011, a medical countermeasure for radiation, can cause adverse health effects in cynomolgus monkeys: Possible toxicity of KMRC011, a medical countermeasure for radiation

High‐dose radiation‐induced tissue damage is a major limiting factor in the medical application of nuclear technology. Herein, we tested 28‐day repeated‐dose toxicity of KMRC011, an agonist of toll‐like receptor (TLR) 5, which is being developed as a medical countermeasure for radiation, using cynomolgus monkeys. KMRC011 (0.01, 0.02 or 0.04 mg/kg/day) was intramuscularly injected once daily for 4 weeks, and each two monkeys in both control and 0.04 mg/kg/day group were observed for an additional 2‐week recovery period. There were no dose‐related toxicological changes in mortality, clinical observations, body weight, food consumption, ophthalmological findings, electrocardiographs, coagulation, serum chemistry, organ weights, or urinalysis and urine chemistry. Although treatment‐related changes, such as increased white blood cells, increased absolute and relative neutrophils, decreased relative lymphocytes and inflammatory lesions, were noted in the maximum dose group, these findings were not observed after the 2‐week recovery period. Further, we considered that the kidneys and heart may be target organs of TLR5 agonists, as well as the spleen, and that autophagic signals can be triggered in tissue damage and the repair process. Importantly, accumulation of p62 protein, an indicator of autophagy, and a decrease of caveolin‐1 protein, a regulator of TLR5 protein half‐life, were found in both tissues from the highest dose group. Therefore, we conclude that the no‐observed‐adverse‐effect level for KMRC011 may be greater than 0.04 mg/kg/day in male and female monkeys. Additionally, we propose that further studies are needed to identify the molecular signals, which are related to KMRC011‐induced adverse effects.