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We evaluated the immunomodulatory effects of a proanthocyanidin-rich extract (PAE) from Pinus radiata bark in Korean native chickens. In experiment 1, proliferation of peripheral blood mononuclear cells was significantly enhanced in chickens administered 1.25, 2.5, 5, and 10 mg/kg of PAE for 2 wk once daily by oral gavage compared with no administration of PAE in vitro. Proliferation of splenocyte and thymocyte cells was also significantly enhanced in chickens administered 1.25, 2.5, 5, and 10 mg/kg of PAE for 5 wk. In experiment 2, proliferation of peripheral blood mononuclear cells, splenocytes, and thymocytes in chickens administered PAE for 6 wk was continuously higher than that in other groups. Additionally, increasing cell populations for which CD4(+)CD8(-)(Th cells) and Bu-1(+) (B cells) protein was expressed on the cell surface were significantly different after 4 wk of PAE administration in chickens. Thus, the immunomodulatory effects of a PAE from P. radiata bark differed by dosing period in chickens.

The complete A+T-rich region of mitochondrial DNA has been cloned and sequenced from 48 individuals of Gryllotalpa orientalis (Orthoptera: Gryllotalpidae), collected from five Korean localities. Thirty-six haplotypes acquired from 48 individuals were found to range in size from 917 to 925 bp, with a sequence divergence from 0.1% to 14.3% and an A+T content from 74.5 to 76.3%. Phylogeographic analysis of the G. orientalis haplotypes showed the presence of two clearly differentiated mitochondrial clades, separated by 13.4% of a minimum uncorrected sequence divergence, which suggests the presence of an unknown, similar Gryllotalpa species or a once isolated G. orientalis population. Structural analysis in search of the conserved structural elements previously described in the caeliferan Orthoptera and Diptera revealed that the G. orientalis A+T-rich region harbored a stretch of the [TA(A)]n sequence, which has been suggested to be involved in the control of transcription or replication. In contrast to the abundance of the sequence stretches containing the stem-and-loop structure in the G. orientalis A+T-rich region, the 3' flanking sequence "G(A)nT," which is well conserved in a variety of organisms, including the caeliferan Orthoptera and Diptera, was not conserved in the A+T-rich region of G. orientalis.

The prevalence and quantity of latent pseudorabies virus (PrV) in nervous tissues of pigs exposed to field strain in Korea was investigated by nested and real-time PCR. Nervous tissues including trigeminal ganglion (TG), olfactory bulb (OB), and brain stem (BS) were collected from 94 seropositive pigs. PrV latent infection in nervous tissues was initially investigated by nested PCR targeting three glycoprotein genes (gB, gE, and gG). Based on the obtained result, latent infection was detected in 95.7% of screened animals. Furthermore, it was revealed that the examined tissues harbored different copy numbers of latent PrV genome ranging from <10(2.0) to 10(7.1) copies per microgram of genomic DNA in real-time PCR analysis. These results show that under normal conditions, levels of latent PrV in the nervous tissues of pigs can vary across a wide range. Therefore, the data presented here provides information regarding control of the endemic state of PrV in Korea.