Echolocation sounds and hearing of the greater Japanese horseshoe bat (Rhinolophus ferrumequinum nippon)

Summary The relationship between the orientation sounds and hearing sensitivity in the greater Japanese horseshoe bat,Rhinolophus ferrumequinum nippon was studied.An orientation pulse consisted of a constant frequency (CF) component followed by a short downward frequency-modulated (FM) component. Sometimes, an initial upward FM component preceded the CF component. Duration of pulses was about 30 ms and the CF of resting pulses (RF) averaged 65.5 kHz. The best frequency (BF) at the lowest threshold in audiograms as measured by the pinna reflex averaged 66.1 kHz. Audiograms showed remarkable sharp cut-offs on both sides near the BF. The frequency difference between the BF and the RF was about 0.6 kHz, and the RF was always below the BF. The values of RF and BF were characteristically different from those of the European subspecies,Rhinolophus ferrumequinum ferrumequinum.Abbreviations BF best frequency - CF constant frequency - FM frequency modulated - RF resting frequency     

Genotoxicity of ptaquiloside, a bracken carcinogen, in the hepatocyte primary culture/DNA-repair test

The genotoxicity of ptaquiloside (PT), recently isolated from bracken fern and shown to be carcinogenic, was examined by means of the hepatocyte primary culture/DNA-repair test. PT elicited clear unscheduled DNA synthesis with a dose-response effect. The result indicates that PT is a genotoxic carcinogen.     

Quantitative structure-activity relationships of structurally similar odorless and odoriferous benzenoid musks

To reveal the difference of molecular property between structurallysimilar odorless and odoriferous musk compounds, 10 pairs ofbenzenoids (monocyclic-, dicyclic- and tricyclic-) were examined.Molecular structures of all compounds were optimized by MNDO(modified neglect of diatomic differential overlap) consideringconformation. Parameters effective in discriminating two groups,group A of 10 odorless compounds and group B of 10 musk odorcompounds, were searched from 34 candidate parameters by adaptiveleast squares. The best three parameters found were log P value(octanol/water partition coefficient), the longest side lengthof hexahedron circumscribing a molecule, and the parameter whichexpresses structural hindrance to the functional group whena molecule approaches the receptor site. The two groups of compoundswere completely discriminated using these three parameters.     

Synthesis of Proteins Enriched in Li+- Induced Vegetalized Embryos of Sea Urchin during Early Development

Sea urchin embryos were vegetalized by a pulse treatment with 60 mM Li⁺ between 2.5 hr and 6 hr after fertilization at 20°C. Normal and Li⁺ -treated embryos were exposed to [³⁵S]-methionine for 2 hr at various stages and [³⁵S]-labeled proteins were analyzed by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE). On fluorograph of 2D-PAGE at the pre-hatching blastula stage, significant difference of labeled proteins between normal and vegetalized embryos was not observed in the range from neutral to acidic pH, but pls of several proteins were found to be shifted toward alkaline pH. At the mesechyme blastula stage, five major proteins [M.W. 36 K, 43 K (two species), 71 K and 150 K] were enriched in Li⁺-treated embryos among a few hundreds of synthesized proteins. At the late gastrula stage, the labeling intensities of these proteins except for one of 43 K proteins increased remarkably in Li⁺-treated embryos. Furthermore, two proteins (M.W. 105 K and 135 K) were also enriched in Li⁺-treated embryos at this stage. At the prism stage, these proteins enriched in Li⁺-treated embryos became hardly detectable, and the synthesis of at least four proteins (M.W. about 20 K, 41 K, 43 K and 200 K<) appeared to increase in normal embryos, but not in Li⁺-treated embryos. Synthesis of proteins eniched in Li⁺-treated embryos probably support endodermal cell differentiation.     

Synthesis of Collagen-Like Proteins in Embryonic Organs of the Sea Urchin, Hemicentrotus pulcherrimus

In sea urchin embryos exposed to ¹⁴C-proline at 20°C for 3 hr at the gastrula, prism or pluteus stage, ¹⁴C-radioactivity was found in hot acid-extractable proteins, in which more than 4% of the radioactivity was detectable in hydroxyproline residues. In these embryos, ¹⁴C-radioactivity in collagen-like proteins was found in the archenteron, spicule and embryo-wall cells. The rate of synthesis of collagen-like proteins was highest in the archenteron in the mid-gastrula stage, in the embryo-wall cells in the prism stage and in the spicule in the pluteus stage. The rate of synthesis decreased in the archenteron and increased in embryo-wall cells in the period between the mid- and late-gastrula stages, when the rate of synthesis in the spicule was quite low. Thereafter, the rate decreased slightly in the embryo-wall cells, was maintained in archenteron and increased markedly in the spicule. The rates of synthesis of collagen-like proteins are high in these embryonic organs at stages at which development and growth respectively, occur in embryos. Therefore, synthesis of collagen-like proteins probably supports morphogenesis in these embryonic organs.     

Molecular cloning and sequence analysis of cDNA for human hepatocyte growth factor

Amino acid sequences of four peptide fragments of human hepatocyte growth factor purified from the plasma of patients with fulminant hepatic failure were determined. Based on the amino acid sequence of one of the fragments, two oligodeoxyribonucleotide mixtures were synthesized and used to screen a human placenta cDNA library. On the screening, two overlapping cDNA clones for human hepatocyte growth factor were isolated and the nucleotide sequence of the cDNA was determined. The entire primary structure of the protein was deduced from the sequence. The protein consists of 728 amino acid residues, including a possible signal peptide at the N-terminus. The sequence revealed that the heavy and light chains which comprise the protein are encoded by the same mRNA and are produced from a common translation product by proteolytic processing.     

UDP-GalNAc : GalNAc-mucin α-N-acetylgalactosamine transferase activity in human intestinal cancerous tissues

GalNAc transferase activities of 6 human intestinal cancerous tissues were examined using bovine submaxillary gland mucin and its desialylated derivative, asialomucin, as acceptors. A Triton X-100 extract of these tissues was used as an enzyme source. All the tissues examined had GalNAc transferase that catalyzes the transfer of GalNAc from UDP-GalNAc to serine or threonine residues of the polypeptide chain. One of 6 specimens showed in addition UDP-GalNAc:GalNAc-mucin α-GalNAc transferase activity, synthesizing a disaccharide unit, GalNAcα→ GalNAc, when asialomucin was used as an acceptor. This carbohydrate structure was deduced on the basis of results of gel filtration, exoglycosidase digestion, and high-voltage paper electrophoresis.GalNAc transferaseHuman intestinal cancerous tissueBovine submaxillary gland mucin O-Glycosidically linked sugar chain     

A Study on Erythrocyte Membrane Plasmalogen in Myotonic Dystrophy

Phospholipid classes that included plasmalogens of erythrocyte membranes in seven myotonic dystrophy (MyD) patients and seven normal controls were analyzed by HPLC. No significant difference in phospholipid classes was found between patients with MyD and normal controls, but there was a visible difference in peak profiles of compounds of the phosphatidylethanolamine class. In the study of plasmalogens, we used two preparation methods: exposure to HCl and deacylation with mild alkaline. The area ratio of the plasmalogen form to the diacyl form in the phosphatidylethanolamine class of MyD erythrocyte membranes was significantly lower than that of normal controls. Fatty acid analyses showed that fatty acids of both phosphatidylethanolamine subclasses have less unsaturation in MyD.     

A microassay for the rapid and selective binding of cells from solid tumors to mouse macrophages

Summary A microassay was developed to study the rapid binding characteristics of murine macrophages activated by gamma interferon and muramyl dipeptide to adherent neoplastic or nonneoplastic target cells. The binding of tumor cells to both activated and nonactivated macrophages was time- and temperature-dependent, and independent of tumor cell type. Activated macrophages bound more tumor cells than nonactivated macrophages. The initial binding of macrophages to target cells did not necessarily lead to lysis. First, primed macrophages bound tumor cells but did not lyse them, and second, nonactivated macrophages bound nontumorigenic cells without subsequent lysis. The rapid binding assay described here could prove useful in investigating the recognition mechanism(s) between macrophages and tumor cells derived from solid primary and metastatic cancers.