Development and biological properties of a new live attenuated mumps vaccine

To develop a new live attenuated mumps vaccine, a wild mumps Y7 strain isolated from a patient who developed mild parotitis was treated with nitrosoguanidine and ultraviolet, followed by selection of a temperature-sensitive clone. The selected clone, Y125, showed stable temperature-sensitivity in Vero cells. Intraspinal inoculation of marmosets with the Y125 produced only minimal histopathological changes, while intracerebral inoculation of neonatal rats revealed that the Y125 did not cause hydrocephalus. Both these effects of the Y125 were similar to those of the non-neurovirulent Jeryl Lynn strain. Furthermore, subcutaneous inoculation of the Y125 induced high levels of neutralizing antibodies in all Cercopithecus monkeys examined. Although the safety and immunogenicity should be confirmed in further field trials in humans, the present results indicate that the Y125 could be a promising vaccine candidate.     

Nuclear genome constitution and other characteristics of somatic hybrids between dihaploid Solanum acaule and tetraploid S. tuberosum

Eleven somatic hybrids (2n = 68 to 74) obtained between S. tuberosum ssp. tuberosum cv. Dejima (2n = 48) and ATDH-1 (2n = 24), an anther-culture-derived dihaploid of S. acaule (Yamada et al., 1997), were characterized by nuclear RFLP markers using 49 single-copy DNA probes distributed throughout the potato genome (2 to 6 probes per chromosome). One of the somatic hybrids, DA8-2, had 72 chromosomes and all the Dejima- and ATDH-1-specific markers (124 and 103 bands, respectively), suggesting the presence of a whole set of both parental chromosomes. The other somatic hybrids lost varying numbers of markers up to seventeen. The pattern of the loss of markers indicated the elimination of five chromosomes among four somatic hybrids. A nucleolar organizer region of chromosome 2 was often eliminated in the somatic hybrids. The somatic hybrids studied here had higher frequencies of multivalent formation than the S. tuberosum parent. They had reasonably good seed set when pollinated with S. tuberosum pollen. Hence, homoeologous recombination between S. acaule and S. tuberosum chromosomes is possible and useful traits from S. acaule may be transferred to the S. tuberosum gene pool. This revised version was published online in July 2006 with corrections to the Cover Date.     

Comparison of the amino acid sequences of acorn barnacle lectins showing different inhibitory activities toward the crystal growth of calcium carbonate

ABSTRACT: The amino acid sequence of a D -galactose-binding lectin isolated from the hemolymph of the acorn barnacle Balanus rostratus was determined. The lectin (BRL) ( M _r 120K) is a multimeric protein whose subunit consists of 182 amino acids. The amino acid sequence was compared with those of multiple lectins (BRA-2, BRA-3) from Megabalanus rosa to explore the relationship between the structures and the inhibitory activity toward the crystal growth of calcium carbonate. Although BRL was 46% identical to BRA-2 and 15% identical to BRA-3, the lectin had no inhibitory activity, unlike BRA-2 and BRA-3. Both the number and the localization of acidic amino acid residues and their amide forms were different among them. Observations by scanning electron microscopy revealed modifications in the size and morphology of the calcium carbonate crystals grown in the presence of the lectins.     

Vortex flow produced by schooling behavior of arabesque greenling <Emphasis Type="Italic">Pleurogrammus azonus</Emphasis>

Arabesque greenling Pleurogrammus azonus form schools of 30,000–60,000 individuals to feed on mesozooplankton near the sea surface. The fish need to be close to the surface where mesozooplankton production occurs, but the food is not sufficiently dense there for the fish to grow optimally while avoiding predation by sea birds. Arabesque greenling use a unique method to optimize their feeding conditions while avoiding staying on the sea surface. When the school swims upward, water is pushed downward. Upward swimming of a school of 30,000 individuals generates a downward stream of about 0.8–1.1 m/s, resulting in a convergent flow near the surface. This convergence concentrates the mesozooplankton on the sea surface and transports them into deeper layers with a strong vortex about 3.0 m in diameter and 10–20 m long. Thus, schooling of this fish induces vortex flows that provide a rich feeding environment.     

Microarray-based gene expression analysis combined with laser capture microdissection is beneficial in investigating the modes of action of ocular toxicity

The retina consists of several layers, and drugs can affect the retina and choroid separately. Therefore, investigating the target layers of toxicity can provide useful information pertaining to its modes of action. Herein, we compared gene expression profiles obtained via microarray analyses using samples of target layers collected via laser capture microdissection and samples of the whole globe of the eye of rats treated with N-methyl-N-nitrosourea. Pathway analyses suggested changes in the different pathways between the laser capture microdissection samples and the whole globe samples. Consistent with the histological distribution of glial cells, upregulation of several inflammation-related pathways was noted only in the whole globe samples. Individual gene expression analyses revealed several gene expression changes in the laser capture microdissection samples, such as caspase- and glycolysis-related gene expression changes, which is similar to previous reports regarding N-methyl-N-nitrosourea-treated animals; however, caspase- and glycolysis-related gene expressions did not change or changed unexpectedly in the whole globe samples. Analyses of the laser capture microdissection samples revealed new potential candidate genes involved in the modes of action of N-methyl-N-nitrosourea-induced retinal toxicity. Collectively, our results suggest that specific retinal layers, which may be targeted by specific toxins, are beneficial in identifying genes responsible for drug-induced ocular toxicity.     

Determination of mechanism of flock sediment formation in tea beverages

The mechanism of sediment formation during the storage of green tea beverage was investigated. Green tea extract was separated by Diaion HP-20 column chromatography, and a sediment-formation test was performed. Results showed that at least one compound of the substance causing flock sediment was contained in each of the HP-20 nonadsorbed and adsorbed fractions. From the following fractionations and structure analyses, the substance in the HP-20 adsorbed fraction was determined to be 1-O-galloyl-4,6-O-(S)-hexahydroxydiphenoyl-beta-D-glucose (strictinin), which is one of the ellagitannins. Strictinin was hydrolyzed to ellagic acid by heat-sterilization processes such as retort sterilization or the ultra-high temperature processing used during the manufacturing of tea beverages. Ellagic acid combined with proteins in the HP-20 nonadsorbed fraction to form an irreversible sediment of green tea beverage; ellagic acid and proteins were confirmed to be present in that sediment. The HP-20 adsorbed fraction contained little strictinin and formed hardly any sediment, suggesting that control of the strictinin content is significant in avoiding sediment formation during the manufacturing process of tea beverages.     

Cryopreservation for preservation of potato genetic resources

Cryopreservation is becoming a very important tool for the long-term storage of plant genetic resources and efficient cryopreservation protocols have been developed for a large number of plant species. Practical procedures, developed using in vitro tissue culture, can be a simple and reliable preservation option of potato genetic resources rather than maintaining by vegetative propagation in genebanks due their allogamous nature. Cryopreserved materials insure a long-term backup of field collections against loss of plant germplasm. Occurrence of genetic variation, in tissue culture cells during prolonged subcultures, can be avoided with suitable cryopreservation protocols that provide high regrowth, leading and facilitating a systematic and strategic cryo-banking of plant genetic resources. Cryopreservation protocols for potato reviewed here, can efficiently complement field and in vitro conservation, providing for preservation of genotypes difficult to preserve by other methods, wild types and other species decided as priority collections.