Sensing of oligopeptides using localized surface plasmon resonances combined with Surface-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

Gold nanorods were fixed on an ITO plate and used for the spectroscopic sensing and Surface-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (SALDI-MS) of oligopeptides (angiotensin I). The longitudinal surface plasmon bands of the gold nanorods responded to the 10(-10) M angiotensin solution that was cast on the ITO plate. The SALDI-MS measurements had an ultra-high sensitivity to the angiotensin on the ITO plate. A very small surface density (5 × 10(-19) mol cm(-2)) of angiotensin could be detected at m/z = 1297 with a good signal/noise ratio (S/N = 11). The ITO plate, which was modified with gold nanorods, was found to be effective in collecting angiotensin molecules adjacent to the gold nanorods, and the SALDI processes that were induced by the photoabsorption of the gold nanorods efficiently contributed to the desorption and ionization of the angiotensin.     

Evaluation of Pulmonary Toxicity of Zinc Oxide Nanoparticles Following Inhalation and Intratracheal Instillation

We conducted inhalation and intratracheal instillation studies of zinc oxide (ZnO) nanoparticles in order to examine their pulmonary toxicity. F344 rats were received intratracheal instillation at 0.2 or 1 mg of ZnO nanoparticles with a primary diameter of 35 nm that were well-dispersed in distilled water. Cell analysis and chemokines in bronchoalveolar lavage fluid (BALF) were analyzed at three days, one week, one month, three months, and six months after the instillation. As the inhalation study, rats were exposed to a concentration of inhaled ZnO nanoparticles (2 and 10 mg/m³) for four weeks (6 h/day, 5 days/week). The same endpoints as in the intratracheal instillation study were analyzed at three days, one month, and three months after the end of the exposure. In the intratracheal instillation study, both the 0.2 and the 1.0 mg ZnO groups had a transient increase in the total cell and neutrophil count in the BALF and in the expression of cytokine-induced neutrophil chemoattractant (CINC)-1, CINC-2, chemokine for neutrophil, and heme oxygenase-1 (HO-1), an oxidative stress marker, in the BALF. In the inhalation study, transient increases in total cell and neutrophil count, CINC-1,-2 and HO-1 in the BALF were observed in the high concentration groups. Neither of the studies of ZnO nanoparticles showed persistent inflammation in the rat lung, suggesting that well-dispersed ZnO nanoparticles have low toxicity.     

Evaluation of gene index for identification of Byssochlamys spp

Comparative sequence analysis was performed on the 18S rRNA gene (1,676 bp), 26/28S rRNA gene D2 region (321 bp) and lys2 (997 bp) to evaluate the gene index for rapid, accurate and convenient identification of Byssochlamys spp. and related species. The results showed that 26 strains (11 species) of the clade could be identified or grouped by means of each gene sequence. The highest resolution to discriminate these species was observed with lys2, but 26/28S rRNA gene D2 region was considered to be the best index for convenient identification. In addition, phylogenetic analysis based on these genes indicated that genus Byssochlamys is not monophyletic, although species in the clade are closely related to each other. Re-classification will be necessary, based on detailed morphological observations.     

Optimisation of vacuum impregnation of blackcurrant‐infused apple cubes: application of response surface methodology

The response surface methodology was used to investigate the effects of blackcurrant concentrate level, vacuum pressure and time on the mass transfer and nutritional properties of vacuum‐impregnated apple cubes. There were higher water loss and weight reduction in the samples at the middle‐level vacuum pressure, but the other factors had no effect on these properties. The higher the vacuum pressure and time, the higher the solids gain of the samples. There was opposing results of the antioxidant capacity of the samples in the middle and high blackcurrant concentrate level and vacuum pressure when compared with the low blackcurrant concentrate level and high vacuum pressure. The middle blackcurrant concentrate level gave higher ascorbic acid content of the samples, while the middle vacuum pressure gave lower values. The optimised conditions for vacuum impregnation of the apple cubes were 18–20% blackcurrant concentrate level, 77–80 kPa vacuum pressure and 38–45 min vacuum time.     

Embryoid body culture of mouse embryonic stem cells using microwell and micropatterned chips

The proliferation and differentiation properties of embryoid bodies (EB) from mouse embryonic stem (ES) cells were compared under two microchip conditions: microwell chip and micropatterned chip. The microwell chip contained 270 microwells (diameter, 600 μm; depth, 600 μm) on a polymethylmethacrylate plate and was surface-modified with polyethylene glycol (PEG) to render it non-adhesive. The micropatterned chip contained 270 gelatin spots (diameter, 200 μm) as the cell adhesion area on a glass plate; the region lacking these spots was PEG-modified to render it non-adhesive. The ES cells spontaneously formed the EBs from cell aggregates in each microwell in the chip. In contrast, cells inoculated onto the patterned chip formed a monolayer on the gelatin spots and gradually proliferated to form EBs. The EBs in the patterned chip maintained the high cell growth rate and the expression of endoderm (TTR and AFP) and mesoderm (Nkx2.5, αMHC, Flk1, and PDGFRβ) markers was increased, and these cell properties were similar to the previous methods (hanging drop and round-bottomed 96-well plate cultures). In contrast, the proliferation of ES cells in the microwell chip was lower than in the patterned chip and previous methods, and the EB differentiation proceeded slowly and only formed a small amount of endoderm. These results indicate that the difference of EB generating process in the microchip cultures may affect to the proliferation and differentiation of ES cells, and the existence of microwell structure in the microchip downregulates the cell proliferation and the differentiated progress of ES cells.     

Bacterial contamination in an egg-breaking factory and its control

From January to November, 2003, bacterial contamination was surveyed in a small egg-breaking factory that produced non pasteurized liquid egg. Test egg samples were taken at various stages of the egg processing operation. Salmonella Enteritidis was isolated from liquid egg yolk and liquid egg white on October, but was not found in any other samples (50 liquid egg samples, 21 containers and 94 attached production facilities and gloves). The data suggest that the contamination rate (3.8%) is lower than those reported previously. Levels of bacterial standard plate counts, gram-positive bacterial counts and gram-negative bacterial counts were in the ranges of 2 to 5 log CFU/g, 2 to 3 log CFU/g, 2 to 5 log CFU/g, respectively. Liquid egg containers returned from customers was contaminated with bacteria at the level of 8 log CFU per container. However, washing and application of a sanitizer containing sodium hypochlorite reduced the bacterial counts.     

Deciphering cellular functions of protein phosphatases by comparison of gene expression profiles in Saccharomyces cerevisiae

Expression profiles of protein phosphatase (PPase) disruptants were analyzed by use of Pearson's correlation coefficient to find profiles that correlated with those of 316 Reference Gene (RG) disruptants harboring deletions in genes with known functions. Twenty-six Δppase disruptants exhibited either a positive or negative correlation with 94 RG disruptants when the p value for Pearson's correlation coefficient was > 0.2. Some of the predictions that arose from this analysis were tested experimentally and several new Δppase phenotypes were found. Notably, Δsit4 and Δsiw14 disruptants exhibited hygromycin B sensitivity, Δsit4 and Δptc1 disruptants grew slowly on glycerol medium, the Δptc1 disruptant was found to be sensitive to calcofluor white and congo red, while the Δppg1 disruptant was found to be sensitive to congo red. Because on-going analysis of expression profiles of Saccharomyces cerevisiae disruptants is rapidly generating new data, we suggest that the approach used in the present study to explore PPase function is also applicable to other genes.     

The microbial community in a 2,4-dinitrophenol-digesting reactor as revealed by 16S rDNA gene analysis

The microbial community of a 2,4-dinitrophenol-digesting reactor was investigated using different molecular biological techniques based on 16S rDNA gene sequences. A PCR-denaturing gradient gel electrophoresis (DGGE) analysis of the bacterial community in the reactor showed that one strong and five minor bands were observed in the DGGE profile. The results of excising and sequencing DGGE bands suggested that members of Rhodococcus, Nocardioides, and Nitrospira species were present in the reactor. Partial sequencing of cloned 16S rDNAs revealed diversity among the six main divisions--the alpha, delta subclasses of Proteobacteria, Nitrospira, Cytophagal Flexibacter/Bacteroides, Verrucomicrobia, and Actinobacteria--in the reactor. Two cloned sequence types were not closely affiliated with any described bacterial divisions. The isolation and phylogenetic analysis of 2,4-DNP-degrading bacteria from the reactor revealed that isolated strains were classified into two types of bacteria having different 16S rDNA sequences. One of these strain types was identified as a relative of Rhodococcus koreensis, and the other was identified as a relative of Nocardioides simplex FJ21-A.