Assessing the Replacement of Electrical Home Appliances for the Environment

To evaluate whether replacing an existing product with a new, more energy‐efficient product is environmentally preferable, we used an assessment approach based on life cycle assessment. With this approach, consumers can assess various replacement products, including products of different sizes or environmental performance in addition to consideration of various conditions of product use. The approach utilizes a diagram in which replacement conditions of products are compared with iso‐environmental‐load lines to determine the appropriateness of replacement. The approach also allows the assessment of energy and resource consumption and environmental impacts not only during the use stage, but also at other product stages. Iso‐environmental‐load lines to assess delayed replacement were also examined and derived. We then applied the approach in a case study of energy consumption by replacing three types of electric home appliances in Japan: TVs, air conditioners, and refrigerators. The results of assessment showed that replacing refrigerators after 8–10 years of use was preferable even if the replacement product was larger. The appropriateness of replacing TVs and air conditioners based on energy consumption depended on the replacement product and on the duration of daily use, and in several cases, delayed replacement was preferable. Replacement of air conditioners after 8–10 years of use was not preferable if the consumer already owned the most energy‐efficient product at the time of the purchase. The necessity of accounting for a variety of available replacement products was confirmed.     

Isolation and characterization of 3-N-trimethylamino-1-propanol-degrading Rhodococcus sp. strain A2

The aerobic degradation of 3- N -trimethylamino-1-propanol (homocholine) as a sole source of carbon and nitrogen has been found for a Rhodococcus sp. bacterium isolated from soil. The isolate was identified as Rhodococcus sp. strain A2 based on its phenotypic features, physiological and biochemical characteristics, and results of phylogenetic analysis. The washed cells of strain A2 completely degraded homocholine within 6 h, with concomitant formation of several metabolites. Analysis of the metabolites using capillary electrophoresis, fast atom bombardment–MS, and GC–MS showed that trimethylamine was the major metabolite, in addition to β-alanine betaine (β-AB) and trimethylaminopropionaldehyde. Therefore, the possible degradation pathway of homocholine in the isolated strain is through consequent oxidation of the alcohol group (-OH) to aldehyde (-CHO) and acid (-COOH). Thereafter, the cleavage of β-AB C–N bonds yielded trimethylamine and alkyl chain.     

In vivo genotoxicity of ortho-phenylphenol, biphenyl, and thiabendazole detected in multiple mouse organs by the alkaline single cell gel electrophoresis assay

In Japan, ortho-phenylphenol (OPP), biphenyl (BP), and thiabendazole (2-(4'-thiazolyl)benzimidazole, TBZ) are commonly used as a postharvest treatment to preserve imported citrus fruits during transport and storage. We used a modification of the alkaline single cell gel electrophoresis (SCG) (Comet) assay to test the in vivo genotoxicity of those agents in mouse stomach, liver, kidney, bladder, lung, brain, and bone marrow. CD-1 male mice were sacrificed 3, 8, and 24 h after oral administration of the test compounds. OPP (2000 mg/kg) induced DNA damage in the stomach, liver, kidney, bladder, and lung, BP (2000 mg/kg) and TBZ (200 mg/kg) induced DNA damage in all the organs studied. For OPP, increased DNA damage peaked at 3–8 h and tended to decrease at 24 h. For BP, on the contrary, increased DNA migration peaked at 24 h. That delay may have been due to the fact that OPP is metabolized by cytochrome 450 and prostaglandin H synthase to phenylbenzoquinone (PBQ), a DNA binding metabolite, and BP is metabolized to PBQ via OPP and m-phenylphenol. The positive response to TBZ, an aneugen, supports the in vivo DNA-damaging action of TBZ.     

Primary structure of human salivary alpha-amylase gene

A recombinant clone which covers the human salivary alpha-amylase gene in a single insert has been isolated from a human genomic DNA library using a human salivary alpha-amylase cDNA as a probe. Restriction mapping and nucleotide (nt) sequence analysis revealed that this gene is approx. 10 kb long and is separated into eleven exons by ten introns. Its 5'-flanking region has some sequence homology with that of mouse salivary alpha-amylase gene [Schibler et al., J. Mol. Biol. 155 (1982) 247-266].