Molecular evolution and diversification of snake toxin genes, revealed by analysis of intron sequences.

The genes encoding erabutoxin (short chain neurotoxin) isoforms (Ea, Eb, and Ec), LsIII (long chain neurotoxin) and a novel long chain neurotoxin pseudogene were cloned from a Laticauda semifasciata genomic library. Short and long chain neurotoxin genes were also cloned from the genome of Laticauda laticaudata, a closely related species of L. semifasciata, by PCR. A putative matrix attached region (MAR) sequence was found in the intron I of the LsIII gene. Comparative analysis of 11 structurally relevant snake toxin genes (three-finger-structure toxins) revealed the molecular evolution of these toxins. Three-finger-structure toxin genes diverged from a common ancestor through two types of evolutionary pathways (long and short types), early in the course of evolution. At a later stage of evolution in each gene, the accumulation of mutations in the exons, especially exon II, by accelerated evolution may have caused the increased diversification in their functions. It was also revealed that the putative MAR sequence found in the LsIII gene was integrated into the gene after the species-level divergence.

Histone deacetylase inhibitors such as sodium butyrate and trichostatin A induce apoptosis through an increase of the bcl-2-related protein Bad.

The effects of sodium butyrate (SB) and trichostatin A (TSA) on cell proliferation andapoptosis against human glioma T98G, U251MG, and U877MG cells were investigated. Upon exposure to either SB or TSA, cell proliferation was reduced, and apoptosis detected by DNA fragmentation analysis and the cleavage of CPP32 was induced. Previously, we reported that SB increased the expression levels of p21 (WAF-1) and inhibited G1-S transition of the cell cycle. In this study, we showed that TSA also increased p21 expression, suggesting that histone deacetylase (HDAC) inhibitors may up-regulate p21 protein in common and thus arrest proliferation in the G1 phase of the cell cycle. To further determine the underlying molecular mechanisms of apoptosis with either SB or TSA treatment, we studied the expression levels of apoptosis-related proteins in human glioma cells. SB increased the expression of the Bad protein, although the expression of Bcl-2, Bcl-xL, Bax, and Fas was not changed by theaddition of SB. TSA treatment also up-regulated the expression of Bad protein. The results suggest that HDAC inhibitors such as SB and TSA induce apoptosis through an increase in Bad protein in human glioma cells in vitro.

Laser microprobe and resonant laser ablation for depth profile measurements of hydrogen isotope atoms contained in graphite.

We measured the depth profile of hydrogen atoms in graphite by laser microprobing combined with resonant laser ablation. Deuterium-implanted graphite was employed for the measurements. The sample was ablated by a tunable laser with a wavelength corresponding to the resonant wavelength of 1S-2S of deuterium with two-photon excitation. The ablated deuterium was ionized by a 2 + 1 resonant ionization process. The ions were analyzed by a time-of-flight mass spectrometer. The deuterium ions were detected clearly with the resonant ablation. The detection limit was estimated to be less than 10(16) atoms/cm(3) in our experiments. We determined the depth profile by considering the etching profile and the etching rate. The depth profile agreed well with Monte Carlo simulations to within a precision of 23 mum for the center position and 4-mum precision for distributions for three different implantation depths.

[Estimation of healthy reference intervals for elderly people through the use of outpatient data].

It is important to determine transferable reference intervals as well as uniformity in measured values for inter-regional and inter-institutional availability of clinical test results. For that purpose, the National Committee for Clinical Laboratory Standards (NCCLS) issued forth guidelines in 1995. Some regional institutions in Japan are making efforts to determine normal reference intervals based on these guidelines. We, the Fukuoka Five Hospitals Group, have selected 3,375 healthy reference individuals and have determined the normal reference intervals for the age groups of 20-29, 30-39, 40-49, and 50-59 years old. The rapidly increasing percentage of elderly people gives rise to ever increasing health-care needs for the elderly, which requires normal reference intervals for older age groups. However, we were unable to collect the required number of the reference individuals above 60 years of age. To obtain reference intervals with adequate reliability and usefulness temporally, we made use of the laboratory data of outpatients at Kyushu University Hospital, and were then easily able to collect the required number of elderly individuals. By performing a very simple selection from among the outpatients, our outpatient group became virtually indistinguishable from the group of healthy reference individuals established by us, with regard to many clinical tests, thus enabling us to estimate reference intervals for older age groups. This approach could be adopted in other regions.