Isolation and characterization of a low molecular weight peptide contained in sourdough

To investigate a sourdough-specific peptide, low molecular weight peptides were extracted from sourdough. The peptide fraction was subjected to two kinds of chromatography to separate the peptides. Reverse-phase chromatography of the peptide fraction in the sourdough showed certain specific peptides. The specific peptide fraction was further separated by gel filtration chromatography. Liquid chromatography tandem mass spectrometry analysis identified one of the peptides as VPFGVG (six-mer). This sequence was estimated to occur at the 287-292 position of a low molecular weight glutenin subunit. The peptide (designed as SDP1) was produced by proteases derived from wheat flour. SDP1 showed angiotensin-converting enzyme (ACE) inhibitory activity, and the 50% inhibitory peptide concentration (IC50) was 336 microM. It is possible that the SDP1 peptide partially confers ACE inhibitory activity in sourdough.     

Subcutaneous Soft Tissue Sarcoma with Rhabdoid Features in a Dog

A nine-year-old male beagle dog had a white spherical mass in the subcutis of the left lumbar region. Microscopically, spindle to oval cells diffusely proliferated in the fibrous and myxoid stroma. Many neoplastic cells showed rhabdoid features or vacuolated cytoplasm. Immunohistochemically, the neoplastic cells were positive for vimentin and S100 and partly positive for neuron-specific enolase and glial fibrillary acidic protein but were negative for von Willebrand factor, desmin and α-smooth muscle actin. Ultrastructurally, the neoplastic cells had abundant cytoplasmic processes and desmosome-like structures. Cytoplasmic inclusions of rhabdoid-featured cells in HE sections were composed of aggregates of intermediate filaments, and cytoplasmic vacuoles were identified as an invagination of cytoplasm. Although malignant peripheral nerve sheath tumor was suggested according to these results, the present case was diagnosed as a soft tissue sarcoma with rhabdoid features due to a lack of identification of the basal lamina under electron microscopy.     

An evaluation of one example of biotope roof in Japan: Plant development and invertebrate colonisation after 8 years

Biotope roofs in Japan are usually intensive green roofs that primarily include native plants and food plants for invertebrates and a pond and stones to create a wide range of habitats. The study aimed to evaluate the survivability of planted species, and colonisation by plants and invertebrates on a biotope roof and to suggest an appropriate planting design and maintenance scheme to optimize biodiversity benefits. An intensive green roof (150 m², substrate depth of 50 cm) was installed in 2002 on the ninth storey of a building at Chiba University, Japan. Twelve species of trees, 18 species of shrubs and 8 species of forbs (mainly native species) were planted and volcanic stones were used as mulch and to create habitats for invertebrates. No maintenance and no irrigation were applied for almost 8 years. A limited number of tree species, such as Myrica rubra and Cinnamomum camphora could grew well without maintenance and irrigation at a substrate depth of 50 cm. Overall, shrubs grew successfully and a high density planting seemed effective in increasing wind resistance. Most forbs disappeared, probably because of drought and competition with these colonising plants. Eleven plant species spontaneously colonised resulting in domination by Solidago altissima and Miscanthus sinensis. These two species were too aggressive, and selective weeding is required for species richness. In an invertebrate study, 46 species in 11 orders were observed and the highest number of invertebrate species was observed in the pond and shady areas.     

Chromosomes responsible for sensitivity of embryo to abscisic acid and dormancy in wheat

The sensitivity of the embryo to abscisic acid (ABA) has been reported toplay an important role in seed dormancy. Using ditelocentric lines of wheatcv. Chinese Spring (CS, nondormant and ABA insensitive), F₂ seedsbetween monosomic lines of CS and a wheat line Kitakei-1354 (dormant,ABA sensitive) and deletion lines of CS chromosome 4A, germinability ofseeds and embryo-half seeds incubated in water and ABA were examined. The results indicated that the long arm of chromosome 4A carried majorgene(s) for the embryo sensitivity to ABA and dormancy. Chromosome2D might be also involved in the sensitivity to ABA.     

Axle-less F1-ATPase rotates in the correct direction

F1-adenosine triphosphatase (ATPase) is an ATP-driven rotary molecular motor in which the central gamma subunit rotates inside a cylinder made of three alpha and three beta subunits alternately arranged. The rotor shaft, an antiparallel alpha-helical coiled coil of the amino and carboxyl termini of the gamma subunit, deeply penetrates the central cavity of the stator cylinder. We truncated the shaft step by step until the remaining rotor head would be outside the cavity and simply sat on the concave entrance of the stator orifice. All truncation mutants rotated in the correct direction, implying torque generation, although the average rotary speeds were low and short mutants exhibited moments of irregular motion. Neither a fixed pivot nor a rigid axle was needed for rotation of F1-ATPase.     

Full three-dimensional photonic bandgap crystals at near-infrared wavelengths

An artificial crystal structure has been fabricated exhibiting a full three-dimensional photonic bandgap effect at optical communication wavelengths. The photonic crystal was constructed by stacking 0.7-micrometer period semiconductor stripes with the accuracy of 30 nanometers by advanced wafer-fusion technique. A bandgap effect of more than 40 decibels (which corresponds to 99.99% reflection) was successfully achieved. The result encourages us to create an ultra-small optical integrated circuit including a three-dimensional photonic crystal waveguide with a sharp bend.     

GaN photonic-crystal surface-emitting laser at blue-violet wavelengths

Shorter-wavelength surface-emitting laser sources are important for a variety of fields, including photonics, information processing, and biology. We report on the creation of a current-driven blue-violet photonic-crystal surface-emitting laser. We have developed a fabrication method, named "air holes retained over growth," in order to construct a two-dimensional gallium nitride (GaN)/air photonic-crystal structure. The resulting periodic structure has a photonic-crystal band-edge effect sufficient for the successful operation of a current-injection surface-emitting laser. This represents an important step in the development of laser sources that could be focused to a size much less than the wavelength and be integrated two-dimensionally at such short wavelengths.     

Effect of 3-O-octanoyl-(+)-catechin on the responses of GABA(A) receptors and Na+/glucose cotransporters expressed in xenopus oocytes and on the oocyte membrane potential

Recently, 3-O-octanoyl-(+)-catechin (OC) was synthesized from (+)-catechin (C) by incorporation of an octanoyl chain into C in the light of (-)-epicatechin gallate (ECg) and (-)-epigallocatechin gallate (EGCg), which are the major polyphenols found in green tea and have strong physiological activities. OC was found to inhibit the response of ionotropic gamma-aminobutyric acid (GABA) receptors (GABA(A) receptors) and Na+/glucose cotransporters expressed in Xenopus oocytes in a noncompetitive manner more strongly than does C. OC also induced a nonspecific membrane current and decreased the membrane potential of the oocyte, and thus death of the oocyte occurred even at lower concentrations than that induced by C or EGCg. Although EGCg produced H2O2 in aqueous solution, OC did not. This newly synthesized catechin derivative OC possibly binds to the lipid membrane more strongly than does C, Ecg, or EGCg and as a result perturbs the membrane structure.