Yusaku Nogami

Benzo(a)pyrene adsorbed to suspended solids in fresh water

The solubility of benzo(a)pyrene (BaP) in water is small, and measured total BaP concentration (t‐BaP) in fresh water is the sum of BaP dissolved in water (d‐BaP) and BaP adsorbed to suspended solids (p‐BaP). We have collected fresh water samples in a lake and rivers in Okayama Prefecture, Japan, and measured both d‐BaP and p‐BaP in each sample. The blue rayon method or solid–liquid extraction was used for extraction of BaP in water or in suspended solids, respectively. The measurement of BaP was done using high‐performance liquid chromatography according to our previously reported method. The present data indicate that p‐BaP was about 1.5 to 5 times higher than d‐BaP. In general, the amount of suspended solids in each sample did not show a correlation to p‐BaP. These results suggest that BaP adsorbed to suspended solids must be taken into account when assessment of t‐BaP is done in any given fresh water sample. © 2000 John Wiley & Sons, Inc. Environ Toxicol 15: 500–503, 2000

Detection of benzo(a)pyrene and mutagenicity in water of Lake Baikal (Russia) and rivers in Okayama (Japan) using the blue rayon method: A simplified handling and transportation of samples from remote sites

Blue rayon, an adsorbent selective to compounds having three or more fused rings, for detecting benzo(a)pyrene and measuring mutagenicity was used in Lake Baikal (Russia), Asahi River, Sasagase River, and Lake Kojima (Okayama, Japan). One gram of blue rayon was immersed in 1 L of water in a bottle, and manually shaken for 30 min. The blue rayon was recovered and transported to the laboratory where the analyses for benzo(a)pyrene and the mutagenicity assay were performed. The recovered benzo(a)pyrene from the water sample ranged from 0.13 to 0.65 ng/L for Lake Baikal and from 0.13 to 1.41 ng/L for the rivers and the lake in Okayama. Six samples out of 11 from Lake Baikal showed positive but weak mutagenicity. No mutagenicity was found in the samples from the rivers and the lake in Okayama. The present method allows easy sampling at remote sites because there is no need for transporting voluminous water samples to the place where analysis is performed. ©1999 John Wiley & Sons, Inc. Environ Toxicol 14: 279–284, 1999

Measurement of a time-weighted average concentration of polycyclic aromatic hydrocarbons in seawater: An improved procedure of blue rayon hanging technique for monitoring benzo(a)pyrene

Abstract We have proposed a time-weighted measurement using blue rayon that selectively adsorbs and concentrates polycyclic aromatic hydrocarbons (PAH), e.g. benzo(a)pyrene (BaP). Though the method was demonstrated to be a convenient way to monitor PAH, the amount adsorbed to the blue rayon depends on the intensity of water stream and the level of PAH. The intensity of water stream was measured by ‘plaster ball’ method, while TWA of PAH in water was measured by a portable sampler using solid phase extraction cartridge. A level of BaP measured by the original blue rayon technique was corrected in this way by the water stream intensity, which correlated well with the TWA of BaP measured by the portable sampler. The improved blue rayon hanging method was applied to several field sites in the Seto Inland Sea of Japan. TWA of BaP ranged from 0.08 to 3.78 ngl−1. These results showed the possibility that the method could be used to evaluate pollution in aquatic environment.

Fibronectin-binding proteins of Clostridium perfringens recognize the III1-C fragment of fibronectin

The Clostridium perfringens strain 13 genome contains two genes (fbpA, fbpB) that encode putative Fbp. Both rFbpA and rFbpB were purified and their reactivity with human serum Fn was analyzed. To determine the region of the Fn molecule recognized by rFbp, a plate binding assay using N‐terminal 70‐kDa peptide, III1‐C peptide, and 110‐kDa peptide containing III2–10 of Fn was performed. Both rFbp bound to the III1‐C peptide of Fn but not to the other peptides. However, the III1‐C fragment of Fn is known to be cryptic in serum Fn. Then, rFbp‐BP from Fn were purified by rFbp‐affinity chromatography. The yield of purified proteins was approximately 1% of the applied Fn on a protein basis. Western blotting analysis of the rFbp‐BP, using four different anti‐Fn monoclonal antibodies, revealed that the rFbp‐BP carried partial Fn antigenicity. Bindings of rFbp to rFbp‐BP were inhibited by the presence of the III1‐C peptide, suggesting that rFbp‐BP express the III1‐C fragment. The binding of Fn to III1‐C was inhibited by the presence of either rFbpA or rFbpB. This result that suggests C. perfringens Fbps may inhibit the formation of Fn‐matrix in vivo.

Fibronectin-binding proteins ofClostridium perfringensrecognize the III1-C fragment of fibronectin

The Clostridium perfringens strain 13 genome contains two genes (fbpA, fbpB) that encode putative Fbp. Both rFbpA and rFbpB were purified and their reactivity with human serum Fn was analyzed. To determine the region of the Fn molecule recognized by rFbp, a plate binding assay using N-terminal 70-kDa peptide, III1-C peptide, and 110-kDa peptide containing III2-10 of Fn was performed. Both rFbp bound to the III1-C peptide of Fn but not to the other peptides. However, the III1-C fragment of Fn is known to be cryptic in serum Fn. Then, rFbp-BP from Fn were purified by rFbp-affinity chromatography. The yield of purified proteins was approximately 1% of the applied Fn on a protein basis. Western blotting analysis of the rFbp-BP, using four different anti-Fn monoclonal antibodies, revealed that the rFbp-BP carried partial Fn antigenicity. Bindings of rFbp to rFbp-BP were inhibited by the presence of the III1-C peptide, suggesting that rFbp-BP express the III1-C fragment. The binding of Fn to III1-C was inhibited by the presence of either rFbpA or rFbpB. This result that suggests C. perfringens Fbps may inhibit the formation of Fn-matrix in vivo.