Selenium Compound Protects Corneal Epithelium against Oxidative Stress

The ocular surface is strongly affected by oxidative stress, and anti-oxidative systems are maintained in corneal epithelial cells and tear fluid. Dry eye is recognized as an oxidative stress-induced disease. Selenium compound eye drops are expected to be a candidate for the treatment of dry eye. We estimated the efficacy of several selenium compounds in the treatment of dry eye using a dry eye rat model. All of the studied selenium compounds were uptaken into corneal epithelial cells in vitro. However, when the selenium compounds were administered as eye drops in the dry eye rat model, most of the selenium compounds did not show effectiveness except for Se-lactoferrin. Se-lactoferrin is a lactoferrin that we prepared that binds selenium instead of iron. Se-lactoferrin eye drops suppressed the up-regulated expression of heme oxygenase-1, cyclooxygenase-2, matrix metallopeptidase-9, and interleukin-6 and also suppressed 8-OHdG production in the cornea induced by surgical removal of the lacrimal glands. Compared with Se-lactoferrin, apolactoferrin eye drops weakly improved dry eye in high dose. The effect of Se-lactoferrin eye drops on dry eye is possibly due to the effect of selenium and also the effect of apolactoferrin. Se-lactoferrin is a candidate for the treatment of dry eye via regulation of oxidative stress in the corneal epithelium.     

Genetic activity of bleomycin in Escherichia coli

The induction of umuC gene expression, cell lethality, induction of W-reactivation of UV-irradiated λ-phage and the induction of mutagenesis caused by bleomycin (Blm) were studied in Escherichia coli K-12 strains with special references to the effects of SOS repair deficiencies. (1) The umuC gene is inducible by Blm and the induction is regulated by the lexA and recA genes. (2) The lexA and recA mutants are slightly more sensitive to Blm-killing than wild-type strain. (3) The plating efficiency of UV-irradiated λ-phage increased by Blm treatment of the host cell. This increase was not observed in the umuC mutant. The plating efficiency of UV-irradiated λ-phage was drastically reduced in the lexA and recA strains treated with Blm. (4) No significant increase of the reversion of nonsense mutation (his-4 to His⁺) in AB1157 by the treatment of Blm was observed. Possible implications of these results are discussed.     

Synthesis and Herbicidal Activities of 1,2-Benzisoxazole-3-acetamide Derivatives

Many 1,2-benzisoxazole-3-acetamides were synthesized and their herbicidal activities in the paddy field were studied. Of the compounds tested, N-α,α-dimethylbenzyl-2-bromo-(1,2-benzisoxazol-3-yl)acetamide 10a was the most effective. Details of the synthesis and the results of herbicidal evaluations are given.     

Studies on Lotus Seed Protease

A protease from the lotus seed (Nelumbo nucifera Gaertn) was purified by acid-treatment, ammonium sulfate-fractionation, ethylalcohol-fractionation, TEAE-cellulose-treatment and Sephadex G-100 gel-filtration.

The enzyme was purified about 870-fold and was homogeneous in electrophoretic and ultracentrifugal analyses.

Purified lotus seed protease is an acid protease with a pH optimum at 3.8 toward urea-denatured casein. It is active for casein and hemoglobin. But other proteins such as edestin, zein, lotus seed globulin and soybean casein are slightly hydrolyzed and egg albumin is hardly hydrolyzed. This enzyme is most stable at pH 4.0 below 40°C. The enzyme is not a thiol protease, and its activity was completely inhibited by potassium permanganate, remarkably inhibited by sodium dodecylsulfate and accelerated by hydrogen peroxide.     

Exclusion of the expansion of CAG/CTG repeats at thirteen loci on chromosome 12 as a candidate genetic mutation in scapuloperoneal spinal muscular atrophy with anticipation

Scapuloperoneal spinal muscular atrophy (SPSMA) is a neuromuscular disorder characterized by weakness in the distribution of shoulder girdle and peroneal muscles. We have previously described a large New England kindred with autosomal dominant SPSMA and have subsequently linked this family trait to 12q24.1-q24.31. In this family, disease expression becomes more severe and progressive in successive generations, suggesting genetic anticipation. Accordingly, we have investigated the thirteen known CAG/CTG repeat loci on chromosome 12 that could be tested by using the polymerase chain reaction as candidate genetic mutations in SPSMA. None of these loci is expanded. Received: 12 June 1996 / Revised: 24 January 1997     

Identification of the replication region of Lactobacillus acidophilus plasmid pLA103

Abstract The structure of the region necessary for replication of the plasmid pLA103 from Lactobacillus acidophilus TK8912 has been characterized. Sequence analysis revealed that the replication region contained an open reading frame (OrfA) encoding a 282-amino acid peptide preceded by a 22-bp tandem repeat sequence region. The predicted OrfA protein showed homology to the replication protein of a plasmid from Pediococcus halophilus . The plasmid containing the repeat sequence region preceding OrfA was able to replicate in the Lactobacillus host when provided with OrfA in trans , suggesting that the repeat sequence region contains the origin sequence essential for the pLA103 replication.     

Tandem location of the cellulase genes on the chromosome of Bacillus sp. strain N-4

Abstract A 5.7-kb Eco RI DNA fragment has been isolated from Bacillus sp. strain N-4 chromosome DNA. This fragment contained both the pNK1-encoded cellulase ( celB ) gene and the pNK2-encoded cellulase ( celA ) gene which were highly homologous [13]. These results demonstrate the tandem location of these genes on the chromosomal DNA. The homologous sequence, which may play an important role for the gene duplication, were observed 5' upstream of the celA gene, between the celA and celB genes, and 3' downstream from the celB gene.