No abstract

Lactococcus garvieae causes fatal haemorrhagic septicaemia in fish such as yellowtail. The comparative analysis of genomes of a virulent strain Lg2 and a non-virulent strain ATCC 49156 of L. garvieae revealed that the two strains shared a high degree of sequence identity, but Lg2 had a 16.5-kb capsule gene cluster that is absent in ATCC 49156. The capsule gene cluster was composed of 15 genes, of which eight genes are highly conserved with those in exopolysaccharide biosynthesis gene cluster often found in Lactococcus lactis strains. Sequence analysis of the capsule gene cluster in the less virulent strain L. garvieae Lg2-S, Lg2-derived strain, showed that two conserved genes were disrupted by a single base pair deletion, respectively. These results strongly suggest that the capsule is crucial for virulence of Lg2. The capsule gene cluster of Lg2 may be a genomic island from several features such as the presence of insertion sequences flanked on both ends, different GC content from the chromosomal average, integration into the locus syntenic to other lactococcal genome sequences, and distribution in human gut microbiomes. The analysis also predicted other potential virulence factors such as haemolysin. The present study provides new insights into understanding of the virulence mechanisms of L. garvieae in fish.

Proximal renal tubular acidosis associated with ocular abnormalities such as band keratopathy, glaucoma, and cataracts is caused by mutations in the Na + -HCO 3 -cotransporter (NBC-1). However, the mechanism by which NBC-1 inactivation leads to such ocular abnormalities remains to be elucidated. By immunological analysis of human and rat eyes, we demonstrate that both kidney type (kNBC-1) and pancreatic type (pNBC-1) transporters are present in the corneal endothelium, trabecular meshwork, ciliary epithelium, and lens epithelium. In the human lens epithelial (HLE) cells, RT-PCR detected mRNAs of both kNBC-1 and pNBC-1. Although a Na + -HCO 3 -cotransport activity has not been detected in mammalian lens epithelia, cell pH (pH i ) measurements revealed the presence of Cl --independent, electrogenic Na + -HCO 3 -cotransport activity in HLE cells. In addition, up to 80% of amiloride-insensitive pH i recovery from acid load in the presence of HCO 3 -/CO 2 was inhibited by adenovirus-mediated transfer of a specific hammerhead ribozyme against NBC-1, consistent with a major role of NBC-1 in overall HCO 3 -transport by the lens epithelium. These results indicate that the normal transport activity of NBC-1 is indispensable not only for the maintenance of corneal and lenticular transparency but also for the regulation of aqueous humor outflow.

The data in the present study suggest that immunotherapy for RSA induced a higher expression of PGR on progesterone-treated lymphocytes, which may be involved in successful pregnancy.

In the investigation reported here, intensity of blue fluorescence or coloration associated with human lens protein of nuclear cataract has been compared with that in the one of normal human. Blue fluorescence as well as coloration associated with proteins of aged normal lens and of nuclear cataractous lens appears to be localized in the nucleus which contains more water-insoluble protein than the cortex. In cortex and nucleus of normal lens, and in cortex of the cataractous lens, the blue fluorescence intensity of the lens protein seems to elevate linearly with an increase of percent urea-soluble protein, accompanied by a decrease of percent water-soluble protein. In nucleus of the cataractous lens, however, the fluorescence intensity tends to decrease significantly with an increase of percent urea-insoluble protein, mostly accompanied by a decrease of percent urea-soluble protein. Coloration of the lens protein tends to become deeper as human lens protein becomes insoluble. Particularly, in nucleus of the cataractous lens which contains urea-insoluble protein at a high concentration, the coloration seems to increase sharply as the content of urea-insoluble protein goes up. These results suggest the possibility that changes in the blue fluorescence intensity and coloration of human lens protein during aging of normal lens and development of nuclear cataract may be related to aggregation of the lens protein.