Isolation of a methylated mannose-binding protein from terrestrial worm Enchytraeus japonensis.

To elucidate a biological role of the methylated mannose residues found in N-glycans of terrestrial worm Enchytraeus japonensis, we first synthesized 3-O-methyl mannose- and 4-O-methyl mannose-derivatives and immobilized them to Sepharose 4B beads in order to isolate the sugar-binding protein. When whole protein extracts from the worms was applied to a series of the columns immobilized with the modified and unmodified mannose-derivatives, respectively, a protein with a molecular weight of 25,000 was isolated by 4-O-methyl mannose-immobilized column chromatography, and termed as a methylated mannose-binding protein (mMBP). mMBP bound weakly to a mannose-immobilized column and moderately to a 3-O-methyl mannose-immobilized column. The N-terminal amino acid sequences of mMBP and its endoprotease-digested peptides were determined. Using the degenerate first primers synthesized based on the primary sequence, a genomic DNA fragment was isolated. Then, the second primers were synthesized based on the genomic DNA fragment, and with use of them two cDNA fragments were obtained by the 3'- and 5'-RACE methods. Finally, the third primers were synthesized based on the sequences of the two cDNA fragments and one genomic DNA fragment, and with use of them a full-length cDNA of mMBP was isolated and shown to comprise a putative 633 bp open reading frame encoding 210 amino acid residues. BLAST analysis revealed that mMBP has identities by 26 ~ 55% to several proteins including the regeneration-upregulated protein 3 from the same species. Whether mMBP is involved in the regeneration of the worm is under investigation.

Imaging aid for thoracic surgery: multidetector-row computed tomography evaluation of the tracheobronchial structure and bronchial tube selection for one-lung anesthesia.

OBJECTIVE: The tracheobronchial structures were evaluated by multidetector-row computed tomography (MDCT), which provided imaging information for one-lung anesthesia during thoracic surgery. METHODS: The subjects consisted of 100 patients. Three-dimensional (3D) images of the tracheobronchial structures and the bronchial tubes were created. RESULTS: Individual differences were found in the tracheobronchial structures in 100 patients. The length and the diameter of the right main bronchus were measured with 3D images and were not related to the patient's physical appearance, such as body height. Problematic intubation cases included a short right main bronchus <10 mm, an anomaly of the right bronchus, and tracheal stenosis. CONCLUSION: The 3D images demonstrated problematic areas of the tracheobronchial structure and helped the anesthesiologists select the most appropriate bronchial tube suitable for the tracheobronchial structure variations. Therefore, this technique is considered to contribute to safer performance of one-lung anesthesia.

Mitochondria are more numerous and smaller in pink-eyed dilution melanoblasts and melanocytes than in wild-type melanocytes in the neonatal mouse epidermis.

Abstract The mouse pink-eyed dilution (p) locus is known to control the melanin content in melanocytes. However, it was not known whether the p gene is involved in regulating the proliferation and differentation of melanocytes during development, especially the biogenesis of melanosomes and other organelles. Epidermal cell suspensions of neonatal dorsal skin derived from mice wild type for the p locus (black, C57BL/10JHir-P/P) and their congenic mutant phenotype (pink-eyed dilution, C57BL/10JHir-p/p) were cultured in serum-free melanocyte-proliferation medium (MDMD). The supplement of additional L-tyrosine (Tyr) into the MDMD stimulated the differentiation of p/p melanoblasts into melanocytes. Electron microscopy revealed that in p/p melanoblasts and melanocytes treated with L-Tyr, the number of stage II and III melanosomes dramatically increased. Moreover, p/p melanoblasts possessed smaller but more numerous mitochondria than P/P melanocytes. The treatment of p/p melanoblasts and melanocytes with L-Tyr decreased the number of mitochondria. The supplement of 2, 4-dinitrophenol (DNP), an inhibitor of mitochondrial function, into the MDMD stimulated both the proliferation and differentiation of p/p melanoblasts. Simultaneous treatment of DNP and L-Tyr dramatically stimulated the differetiation of p/p melanocytes. These results suggest that L-Tyr and some unknown factors related to mitochondrial function may influence the differentiation of melanoblasts in the epidermis of p/p mice.

Behavior of nuclei during zoosporogenesis in Bryopsis plumosa (Bryopsidales, Chlorophyta).

The behavior of nuclei during zoosporogenesis in Bryopsis plumosa (Bryopsidales, Chlorophyta) was examined by fluorescence and electron microscopy. Each mature filamentous sporophyte had a single lenticular nucleus, which was about 25 microm in diameter and embedded in a thick cytoplasmic layer. At the commencement of multinucleation, giant nuclei with large vacuolated nucleoli, giant nuclei containing chromosomes, and dumbbell-shaped nuclei were observed. Sometimes, two small nuclei also appeared in the thick cytoplasm where the giant nucleus had presumably been present. Electron microscopy revealed the existence of ribbon-like structures resembling synaptonemal complexes within the nucleus having a large vacuolated nucleolus. Nuclei extended their distribution by repetitive divisions. A pair of centrioles was adjacent to the interphase nucleus. When the nuclei were distributed throughout the cell, they became localized nearly equidistantly from one another, each being surrounded by several chloroplasts. At this stage, many centrioles lay along the nuclear surface. The bulk of cytoplasm was then divided into many masses of protoplasm, each of which developed into a uninucleate, stephanokontic zoospore with a whorl of flagella.

Stem water transport of Lithocarpus edulis, an evergreen oak with radial-porous wood.

The stem water conducting system of an evergreen broad-leaved oak, Lithocarpus edulis (Mak.) Nakai, was investigated. Evergreen broad-leaved oaks (Lithocarpus, Castanopsis, Cyclobalanopsis, Quercus) belonging to the Quercoideae are a major component of Asian monsoon forests, and are characterized by the possession of radial-porous wood. A characteristic of radial-porous wood is the development of aggregate rays between radially oriented files of vessels. We measured the distribution of vessel lumen diameters in a stem cross section and calculated the theoretical water conductivity of the wood. The radial profile of the heat pulse velocity (HPV) was measured for an intact whole tree under field conditions and compared with the theoretical distribution of water conductivity. Soft X-ray photographs of frozen stem sections indicated that most of the vessel lumina were filled with water, including those of vessels more than 20 years old. Even when vessels were relatively wide (lumen diameters > 100 microm), cavitation was negligible. The rate of water uptake from the cut stem base correlated closely with HPV (r = 0.96), and HPV closely reflected the mean volume flow per stem sectional area (SFVS) around the sensor probes. However, the ray tissue sharply inhibited heat transfer, and the positioning of the probes strongly affected the absolute value of HPV. It was also found that HPV more closely reflected the mean sap flow velocity in the vessels than did SFVS.

Purification and properties of a lectin from ascomycete mushroom, Ciborinia camelliae.

A lectin was isolated from an ascomycete mushroom, Ciborinia camelliae which was specific to N-acetyl-D-galactosamine. On SDS-polyacrylamide gel electrophoresis; this lectin gave a single band of approximately 17-kDa in the presence of 2-mercaptoethanol, but formed dimers, trimers and tetramers in its absence. Amino acid analysis revealed the lectin contained two cysteines and no methionine. The N-terminal sequence was determined up to residue 21, and no homologous proteins including other ascomycete lectins were found.