The antibacterial activity of plaunotol against Staphylococcus aureus isolated from the skin of patients with atopic dermatitis.

Plaunotol was tested for possible antibacterial activity against twenty strains of methicillin-resistant Staphylococcus aureus (MRSA) and fourteen strains of methicillin-sensitive S. aureus (MSSA) which had been isolated from the skin of patients with atopic dermatitis under growth-promoting conditions. Plaunotol was effective against all strains tested. The dose of plaunotol for 50% inhibition of growth (ID50) ranged from 2.5 to 16 micrograms/ml for strains of MRSA and from 2.5 to 7.0 micrograms/ml for those of MSSA. These results suggest that plaunotol may be useful in the prevention of infection by MRSA and in skin care for patients with atopic dermatitis.     

Switching of metabolic-rate scaling between allometry and isometry in colonial ascidians

The metabolic rate and its scaling relationship to colony size were studied in the colonial ascidian Botrylloides simodensis. The colonial metabolic rate, measured by the oxygen consumption rate (V(O2) in millilitres of O(2) per hour) and the colony mass (wet weight M(w) in grams) showed the allometric relationship (V(O2) = 0.0412 M(w)(0.799). The power coefficient was statistically not different from 0.75, the value for unitary organisms. The size of the zooids and the tunic volume fraction in a colony were kept constant irrespective of the colonial size. These results, together with the two-dimensional colonial shape, excluded shape factors and colonial composition as possible causes of allometry. Botryllid ascidians show a takeover state in which all the zooids of the parent generation in a colony degenerate and zooids of a new generation develop in unison. The media for connection between zooids such as a common drainage system and connecting vessels to the common vascular system experienced reconstruction. The metabolic rate during the takeover state was halved and was directly proportional to the colonial mass. The scaling thus changed from being allometric to isometric. The alteration in the scaling that was associated with the loss of the connection between the zooids strongly support the hypothesis that the allometry was derived from mutual interaction among the zooids. The applicability of this hypothesis to unitary organisms is discussed.     

Auxin-inducible protein depletion system in fission yeast

Background  

Inducible inactivation of a protein is a powerful approach for analysis of its function within cells. Fission yeast is a useful model for studying the fundamental mechanisms such as chromosome maintenance and cell cycle. However, previously published strategies for protein-depletion are successful only for some proteins in some specific conditions and still do not achieve efficient depletion to cause acute phenotypes such as immediate cell cycle arrest. The aim of this work was to construct a useful and powerful protein-depletion system in Shizosaccaromyces pombe.     

Chromosome banding and FISH with rDNA probe in the diploid and tetraploid loach Misgurnus anguillicaudatus

The chromosomes of the diploid and tetraploid loach Misgurnus anguillicaudatus were analyzed by staining with Ag, chromomycin A₃ (CMA₃)/distamycin A (DA), and DA/4′,6-diamidino-2-phenylindole (DAPI), and using fluorescence in situ hybridization (FISH) with 5.8S + 28S rDNA as a probe. Nucleolus organizer regions (NORs) were mapped to the telomeric region of the short arms of the largest (first) metacentric chromosome pair in the diploid loach with 2n = 50 and the homologous quartet in the tetraploid loach with 4n = 100. The NORs were positive at the same region of the first metacentric chromosome for Ag and CMA₃/DA stainings, but negative for DA/DAPI staining. Four signals at the homologs within the same quartet suggest the duplication of the entire genome from diploid to tetraploid status. However, a size difference was detected between the rDNA signals by FISH and CMA₃ banding.     

Association between dental health behaviours, mental/physical function and self-feeding ability among the elderly: a cross-sectional survey

Objectives : The aim of this study was to determine the association between dental health behaviour, mental/physical function and self‐feeding ability among the elderly. Subjects : A total of 414 elderly dental patients aged 65 years and older participated in this study. Methods : A survey was carried out for three years and seven months starting in January 1998 at the Chubu National Hospital. The patients or their carers were examined/interviewed about the severity of senile dementia, dental health behaviour, ability to rinse their mouths, ability to manage dentures, and ability to sit at a table during meals. To assess the association with self‐feeding ability among the elderly, cut‐offs were given for these variables, and then the odds ratios were calculated. Results : The strongest association to self‐feeding ability was marked by inability to rinse their own mouth, followed by inability to manage dentures, inability to sit at a table during meals, severe senile dementia and less frequency of toothbrushing. Conclusion : Elderly who have lost the feeding ability often could not maintain their dental health by themselves. Carers must provide not only a feeding service with acknowledgement of aspiration but oral care to prevent dental disease and fatal pneumonia in the elderly.     

Testing the relationship between foldability and the early folding events of dihydrofolate reductase from Escherichia coli

A "folding element" is a contiguous peptide segment crucial for a protein to be foldable and is a new concept that could assist in our understanding of the protein-folding problem. It is known that the presence of the complete set of folding elements of dihydrofolate reductase (DHFR) from Escherichia coli is essential for the protein to be foldable. Since almost all of the amino acid residues known to be involved in the early folding events of DHFR are located within the folding elements, a close relationship between the folding elements and early folding events is hypothesized. In order to test this hypothesis, we have investigated whether or not the early folding events are preserved in circular permutants and topological mutants of DHFR, in which the order of the folding elements is changed but the complete set of folding elements is present. The stopped-flow circular dichroism (CD) measurements show that the CD spectra at the early stages of folding are similar among the mutants and the wild-type DHFR, indicating that the presence of the complete set of folding elements is sufficient to preserve the early folding events. We have further examined whether or not sequence perturbation on the folding elements by a single amino acid substitution affects the early folding events of DHFR. The results show that the amino acid substitutions inside of the folding elements can affect the burst-phase CD spectra, whereas the substitutions outside do not. Taken together, these results indicate that the above hypothesis is true, suggesting a close relationship between the foldability of a protein and the early folding events. We propose that the folding elements interact with each other and coalesce to form a productive intermediate(s) early in the folding, and these early folding events are important for a protein to be foldable.     

Isolation and sequence determination of rat cardiac natriuretic peptide

We have isolated a cardiac natriuretic peptide of 5K daltons from the rat atrium and determined its amino acid sequence. The 5K cardiac natriuretic peptide was elucidated to be a 45-amino acid peptide with the sequence of S-Q-D-S-A-F-R-I-Q-E-R-L-R-N-S-K-M-A-H-S-S-S-C-F-G-Q-K-I-D-R-I-G-A-V-S-R- L-G-C-D - G-L-R-L-F by sequencing the native peptide and its lysyl endopeptidase digests. The sequence of this peptide was identical to the amino acid sequence [51-95] of the rat brain natriuretic peptide (BNP) precursor deduced from the cDNA sequence. The 5K cardiac natriuretic peptide, or BNP[51-95], was identified as the major storage and secretory form derived from the BNP precursor in the rat heart.     

Estrogen regulation of nitric oxide synthesis in the porcine oocyte

The endothelial type (NOS-3) of three isoforms of nitric oxide (NO) synthase occurs in porcine oocytes and granulosa cells, but the regulation of NO synthesis in oocytes remains unknown. The present study was designed to evaluate steroid control in the process of oocyte NO synthesis. Cumulus-oocyte complexes (COCs), obtained from small-sized antral follicles of immature porcine ovaries, were cultured in estrogen-deprived medium, and the effect of steroids or steroid-free porcine follicular fluids on the NO release from oocytes was investigated. Oocytes that were isolated from cultured COCs were incubated with 1 microM ionomycin. The NO metabolites were identified using a NO detector-high-pressure liquid chromatography system. Oocytes from COCs cultured with 10 nM 17beta-estradiol (E2) released NO in response to ionomycin, whereas progesterone and testosterone had little effect on the synthesis of NO. An inhibitor of NOS suppressed the synthesis of NO. The maximal synthesis was observed after a 15 h-culture with E2. However, oocytes freshly obtained from antral follicles did not response to ionomycin, and the E2 action was suppressed by the addition of steroid-free follicular fluids. Analyses of RT-PCR and Western blotting showed that E2 did not increase NOS-3 expression. In addition, estrogen receptor beta was detected in oocytes and cumulus cells, and estrogen receptor alpha was detected only in cumulus cells. These findings suggest that oocyte NOS-3 is promoted for the synthesis of NO by E2 without increases in NOS-3 expression, but the synthesis of NO is suppressed, at least in the oocytes of early antral follicles.