Complete sequence analysis of human norovirus GII.17 detected in South Korea.

Norovirus, a major cause of gastroenteritis in people of all ages worldwide, was first reported in South Korea in 1999. The most common causal agents of pediatric acute gastroenteritis are norovirus and rotavirus. While vaccination has reduced the pediatric rotavirus infection rate, norovirus vaccines have not been developed. Therefore, prediction and prevention of norovirus are very important. Norovirus is divided into genogroups GI-GVII, with GII.4 being the most prevalent. However, in 2012-2013, GII.17 showed a higher incidence than GII.4 and a novel variant, GII.P17-GII.17, appeared. In this study, 204 stool samples collected in 2013-2014 were screened by reverse transcriptase-polymerase chain reaction; 11 GI (5.39%) and 45 GII (22.06%) noroviruses were identified. GI.4, GI.5, GII.4, GII.6 and GII.17 were detected. The whole genomes of the three norovirus GII.17 were sequenced. The whole genome of GII.17 consists of three open reading frames of 5109, 1623 and 780 bp. Compared with 20 GII.17 strains isolated in other countries, we observed numerous changes in the protruding P2 domain of VP1 in the Korean GII.17 viruses. Our study provided genome information that might aid in epidemic prevention, epidemiology studies and vaccine development.

In vitro generation of immune effector cells from tumor-associated lymphocytes of human gastric cancer.

Despite recent advances in cellular immunotherapy of cancer, the effectiveness of this type of treatment is limited only to some types of cancer. This study was performed to generate tumor-specific cytotoxic T lymphocytes (CTL) for the treatment of gastric cancer and to find the optimal culture conditions for this CTL, because most immune effector cells used in the previous trials were non-specific killers. Lymphocytes were isolated from tumors, tumor-draining lymph nodes, malignant ascites and peripheral blood of 29 patients with gastric cancer. Lymphocytes from each source were then cultured for three weeks under one or more of the following conditions: 1) 50 U/ml of rIL-2; 2) 50 U/ml of rIL-2 + irradiated (6,000 rad) fresh autologous tumor cells (in vitro sensitization - IVS); 3) 1,000 U/ml of rIL-2; 4) 1,000 U/ml of rIL-2 + IVS. The study found that 1,000 U/ml of rIL-2 generated higher cytotoxicity against allogeneic tumor targets than 50 U/ml of rIL-2 (p < 0.05). However, neither the concentration of rIL-2, lymphocyte source, nor IVS produced any significant differences in cytotoxicity against fresh autologous tumor cell targets. The data suggested that immune effector cells for gastric cancer could be generated efficiently, but it was difficult to produce CTL specific for autologous tumor cells of gastric cancer using a low concentration of rIL-2 and/or in vitro sensitization with autologous irradiated tumor cells.

Human rotavirus genotypes in hospitalized children, South Korea, April 2005 to March 2007.

Availability of new rotavirus vaccines highlights the need to maintain and enhance rotavirus strain surveillance. We collected stool samples from children with gastroenteritis admitted to eight hospitals in South Korea from April 2005 to March 2007. Of the 6057 samples collected, 1337 (22%) were positive for rotavirus by one of several antigen detection assays. G and P genotypes were identified for 1299 (97%) of rotavirus-positive specimens. G1P[8] (36%) was the most prevalent strain, followed by G3P[8] (16%), G4P[6] (8.9%) and G1P[6] (8.2%). G1P[8] was also the most prevalent strain in each hospital. Seasonal peaks of rotavirus infection were noted from November 2005 to April 2006 and January to March 2007. This large-scale surveillance study provides important insights into rotavirus genotype distribution and pattern changes in South Korea.

Comparison of telomerase activity and GSTP1 promoter methylation in ejaculate as potential screening tests for prostate cancer.

New diagnostic tools are needed for the early detection of prostatic cancer. The molecular detection of prostate cancer cells in ejaculates was evaluated using complementary PCR-based methods. LNCaP cells, a cell line derived from prostatic carcinoma, were spiked into normal seminal ejaculates and the prostatic epithelial component of the specimens was isolated by immunomagnetic bead sorting, using a monoclonal antibody to prostate-specific membrane antigen (PSMA). Ejaculates from nine patients with a recent diagnosis of prostate cancer were processed in a similar fashion, using LNCaP-spiked aliquots as an internal positive control. Telomerase expression was evaluated by the telomeric repeat amplification protocol (TRAP) and glutathione S-transferase gene promoter (GSTP1) hypermethylation was evaluated by methylation-sensitive restriction endonuclease digestion and PCR amplification. Telomerase activity was detected in LNCaP cells recovered from normal seminal ejaculates but was not found in all nine samples from patients with prostate cancer. The sensitivity of GSTP1 analysis was similar to telomerase analysis for the detection of LNCaP cells from normal ejaculate samples but was positive in ejaculates from four out of nine patients with prostate cancer. GSTP1 DNA methylation status is more sensitive than telomerase analysis for the detection of malignant cells in seminal ejaculates from patients with prostate cancer.