Human Coronavirus in the 2014 Winter Season as a Cause of Lower Respiratory Tract Infection

PURPOSE: During the late autumn to winter season (October to December) in the Republic of Korea, respiratory syncytial virus (RSV) is the most common pathogen causing lower respiratory tract infections (LRTIs). Interestingly, in 2014, human coronavirus (HCoV) caused not only upper respiratory infections but also LRTIs more commonly than in other years. Therefore, we sought to determine the epidemiology, clinical characteristics, outcomes, and severity of illnesses associated with HCoV infections at a single center in Korea. MATERIALS AND METHODS: We retrospectively identified patients with positive HCoV respiratory specimens between October 2014 and December 2014 who were admitted to Severance Children’s Hospital at Yonsei University Medical Center for LRTI. Charts of the patients with HCoV infection were reviewed and compared with RSV infection. RESULTS: During the study period, HCoV was the third most common respiratory virus and accounted for 13.7% of infections. Coinfection was detected in 43.8% of children with HCoV. Interestingly, one patient had both HCoV-OC43 and HCoV-NL63. Mild pneumonia was most common (60.4%) with HCoV, and when combined with RSV, resulted in bronchiolitis. Two patients required care in the intensive care unit. However, compared with that of RSV infection, the disease course HCoV was short. CONCLUSION: Infections caused by HCoVs are common, and can cause LRTIs. During an epidemic season, clinicians should be given special consideration thereto. When combined with other medical conditions, such as neurologic or cardiologic diseases, intensive care unit (ICU) care may be necessary.

Ser1778 of 53BP1 Plays a Role in DNA Double-strand Break Repairs

53BP1 is an important genome stability regulator, which protects cells against double-strand breaks. Following DNA damage, 53BP1 is rapidly recruited to sites of DNA breakage, along with other DNA damage response proteins, including gamma-H2AX, MDC1, and BRCA1. The recruitment of 53BP1 requires a tandem Tudor fold which associates with methylated histones H3 and H4. It has already been determined that the majority of DNA damage response proteins are phosphorylated by ATM and/or ATR after DNA damage, and then recruited to the break sites. 53BP1 is also phosphorylated at several sites, like other proteins after DNA damage, but this phosphorylation is not critically relevant to recruitment or repair processes. In this study, we evaluated the functions of phosphor-53BP1 and the role of the BRCT domain of 53BP1 in DNA repair. From our data, we were able to detect differences in the phosphorylation patterns in Ser25 and Ser1778 of 53BP1 after neocarzinostatin-induced DNA damage. Furthermore, the foci formation patterns in both phosphorylation sites of 53BP1 also evidenced sizeable differences following DNA damage. From our results, we concluded that each phosphoryaltion site of 53BP1 performs different roles, and Ser1778 is more important than Ser25 in the process of DNA repair.

Human metapneumovirus infection in Korean children / 소아과

PURPOSE: Human metapneumovirus(hMPV) is a respiratory viral pathogen that causes a wide spectrum of illnesses, ranging from asymptomatic infection to severe bronchiolitis. The virus has been identified world widely, but so far it has not been published in Korea. METHODS: We obtained clinical samples by nasopharyngeal aspiration from 218 children hospitalized due to acute lower respiratory tract infections at Soonchunhyang University Hospital in Cheonan from October, 2004 to April, 2005. We designed specific primers from conserved region of fusion glycoprotein of hMPV. Total RNA was extracted and RT-PCR was performed, and single specific 423 bp product was obtained. The PCR product was confirmed to be fusion glycoprotein RNA by sequencing. RESULTS: We detected hMPV in 15(6.9 percent) of the 218 hospitalized children. The infected children comprised nine boys and six girls; their mean age was 2.8 years(5 mo-12 yrs) and they were diagnosed with pneumonia(60 percent), bronchiolitis(33.3 percent), croup(6.6 percent). The number of cases of detected hMPV in Korea increased dramatically during the period from March to May 2005. CONCLUSION: hMPV is circulating in Korean children and is associated with respiratory tract infection. Additional studies are required to define the epidemiology and the extent of diseases in the general population caused by hMPV.

Immunophenotypic Analysis of Long-term Culture-Initiating Cells in Long-term Liquid Culture / 대한소아혈액종양학회지

Purpose: Long-term culture- initiating cells(LTC-IC) are stem cells that have the capacities of long-term engraftment and helping to establish hematopoietic microenvironment. For evaluation of the LTC-IC, we measured the counts and function with multidimentional flowcytometry in long-term culture media. METHODS: Samples were obtained from umbilical cord blood, leukapheresis products and bone marrow(BM). LTC-IC were counted with flowcytometric analysis using anti- CD34, anti-CD38, and anti-HLA-DR antibodies at 0, 5, and 8 weeks. Cell adhesion molecule related with stem cell were evaluated with flowcytometric analysis also using anti-VCAM-1(CD106) and anti-VLA-4(CD49d) at 0 and 8 weeks. RESULTS: The proportion of CD34+/CD38- cell from fractionated mononuclear cells at 0 week were 0.46%, 0.044%, and 0.038% for BM, leukapheresis products, and umbilical cord blood respectively and then rapidly decreased at 5 weeks, but still persisted at 8 weeks in all three groups. The proportion of CD34+/HLA-DR- cells was the same tendency to CD34+/CD38-. VCAM+ expression rate from fractionated CD34+ cells at 0 and 8 weeks were 67.3% and 40.2% for BM and 64.1% 44.2% for umbilical cord blood but it was very low 31.2% and 5.1% for leukapheresis products. VLA-4+ expression rate for fractionated CD34+ cells at 0 and 8 weeks were similar tendency to VCAM+ cells. CONCLUSION: This study suggest that the count of LTC-IC decreased with time but still persisted until 8 weeks. Umbilical cord blood including BM help to establish the hematopoietic microenvironments.