Baseline correction using asymmetrically reweighted penalized least squares smoothing.

Baseline correction methods based on penalized least squares are successfully applied to various spectral analyses. The methods change the weights iteratively by estimating a baseline. If a signal is below a previously fitted baseline, large weight is given. On the other hand, no weight or small weight is given when a signal is above a fitted baseline as it could be assumed to be a part of the peak. As noise is distributed above the baseline as well as below the baseline, however, it is desirable to give the same or similar weights in either case. For the purpose, we propose a new weighting scheme based on the generalized logistic function. The proposed method estimates the noise level iteratively and adjusts the weights correspondingly. According to the experimental results with simulated spectra and measured Raman spectra, the proposed method outperforms the existing methods for baseline correction and peak height estimation.

Cancer cell growth inhibitory effect of bee venom via increase of death receptor 3 expression and inactivation of NF-kappa B in NSCLC cells.

Our previous findings have demonstrated that bee venom (BV) has anti-cancer activity in several cancer cells. However, the effects of BV on lung cancer cell growth have not been reported. Cell viability was determined with trypan blue uptake, soft agar formation as well as DAPI and TUNEL assay. Cell death related protein expression was determined with Western blotting. An EMSA was used for nuclear factor kappaB (NF-κB) activity assay. BV (1-5 µg/mL) inhibited growth of lung cancer cells by induction of apoptosis in a dose dependent manner in lung cancer cell lines A549 and NCI-H460. Consistent with apoptotic cell death, expression of DR3 and DR6 was significantly increased. However, deletion of DRs by small interfering RNA significantly reversed BV induced cell growth inhibitory effects. Expression of pro-apoptotic proteins (caspase-3 and Bax) was concomitantly increased, but the NF-κB activity and expression of Bcl-2 were inhibited. A combination treatment of tumor necrosis factor (TNF)-like weak inducer of apoptosis, TNF-related apoptosis-inducing ligand, docetaxel and cisplatin, with BV synergistically inhibited both A549 and NCI-H460 lung cancer cell growth with further down regulation of NF-κB activity. These results show that BV induces apoptotic cell death in lung cancer cells through the enhancement of DR3 expression and inhibition of NF-κB pathway.

Molecular epizootiology of recurrent low pathogenic avian influenza by H9N2 subtype virus in Korea.

The first outbreak of low pathogenic avian influenza (LPAI), H9N2 virus subtype, in 1996 prompted an eradication response, but LPAI returned to Korea in 1999. The relationship between the first and the recurrent viruses is unclear. To determine the molecular epizootiology of recurrent LPAI, we performed phylogenetic analysis with partial nucleotide sequences of four gene segments (HA, NA, NP and PB2) from eight chicken-origin H9N2 viruses. The recurrent H9N2 viruses showed higher nucleotide similarity in haemagglutinin and neuraminidase genes to the 1996 Korean isolates than other Eurasian viruses, and formed a distinct cluster with the early Korean isolates and some isolates from migratory and domestic ducks in Japan and China. Phylogenetic analysis with internal genes showed that some Korean isolates formed a cluster with other subtypes, such as H5N1, H6N1, and H6N2 in China and Taiwan. These results suggest that the recurrent viruses are progeny of the early Korean H9N2 isolates, but further studies are required to explain their phylogenetic relatedness to viruses in China.

Molecular epidemiology of Newcastle disease in Republic of Korea.

Twenty-three strains of Newcastle disease virus (NDV) isolated between 1988 and 1999 in Republic of Korea were studied by partial nucleotide sequencing of fusion (F) gene and phylogenetic analysis. Most of Korean strains formed a distinctive cluster in genotype VI and they were genetically distant (4.0-8.7%) from other subtypes (a, b, c, d, and e), and termed provisionally VIf. Some Korean strains isolated in 1995 were grouped into genotype VIIa and they were closer to Taiwan strains than western Europe. The results suggest that the genotype VIf strains have been maintained by enzootic infections during the past decade, while genotype VIIa appears to be introduced more recently in Republic of Korea.