Isolation of a cardiotonic glycoprotein,striatoxin, from the venom of the marine snail Conus striatus

Striatoxin, a powerful cardiotonic glycoprotein has been isolated from the venom of the marine snail Conus striatus, monitored by the inotropic action on the guinea-pig left atria. The molecular weight was estimated to be 25,000 by gel filtration. The purified glycoprotein is electrophoretically homogeneous. The toxin at concentrations above 10^?7 g/ml has a long-lasting inotropic action, which was abolished by tetrodotoxin (10^?6 M). The minimum lethal dose in the fish Rhodeus ocellatus smithi was 1 μg/g body weight. A possible biological role of striatoxin in C. striatus is briefly discussed.     

The effect of sound location in a song-discrimination task by Bengalese finches (<Emphasis Type="Italic">Lonchura striata</Emphasis> var. <Emphasis Type="Italic">domestica</Emphasis>)

To understand the relationship between song perception and stimulus location, Bengalese finches were trained to discriminate between a normally played conspecific song and the reversed song. Loudspeakers on the opposite side of the response key (experimental condition) and above the subject (control condition) were used to present stimuli. All control birds learned the task, whereas some experimental subjects did not. In general, controls learned the task more quickly than experimental animals. These results suggest that sound location may be closely associated with behavioral responses in this species. Bioacoustical investigations should be performed while taking these results into consideration.     

Flexibacter japonensis sp. nov., a New Species That Produces a Novel Inhibitor of Human Leukocyte Elastase Isolated from Soil

This strain 758 of a new member of Flexibacter species isolated from a soil is a Gram-negative, nonflagellated, gliding, long rod or filamentous. The GC contents of the deoxyribonucleic acid of this strain is 49.8 mol %GC. The isolate can be distinguished from other Flexibacter species on the basis of physiological and biochemical properties and DNA relatedness data. Therefore, we propose a new species, Flexibacter japonensis, for this strain. The strain 758 is deposited to the Japan Collection of Microorganisms as JCM 9735. Received: 27 November 1995 / Accepted: 30 January 1996     

New O and H antigens ofPlesiomonas shigelloides and their O antigenic relationships toShigella boydii

Twenty six new O (O51-O76) and 24 new H (H18-H41) antigens forPlesiomonas shigelloides serotyping scheme were defined. The O antigens 54 and 57 were closely related to those ofShigella boydii 2 and 9, respectively, in an a, b-a, c type of relationship.     

Marked Alteration at Midblastula Transition in the Effect of Lithium on Formation of the Larval Body Pattern of Xenopus laevis

Embryos of Xenopus laevis were exposed to 0.4 M LiCl for 5 min at various stages of development. The effect of lithium on the larval body pattern could be detected from the 2-cell to the late gastrula stage, but changed from reduction of posterior structures ("anteriorization") to reduction of anterior structures ("posteriorization") just after the 12th cleavage, the time of midblastula transition (MBT). Temporal coincidence of MBT with alteration of the effect of lithium was observed even with embryos derived from half-egg fragment, in which MBT occurs just after the 11th cleavage. These results suggest the existence of a mechanism for formation of the basic plan of the larval body whose function changes at MBT. Combinations of the pre- and post-MBT exposures to lithium induced marked posteriorization in most larvae, indicating that the basic plan is not irreversibly determined until MBT, but is fixed during post-MBT stages.     

Immunohistochemical localization of Met-enkephalin, Met-enkephalin-Arg6-Gly7-Leu8, Met-enkephalin-Arg6-Phe7 and Leu-enkephalin in human adrenal medulla and pheochromocytomas

Immunohistochemical localization of Met-enkephalin, Met-enkephalin-Arg6-Gly7-Leu8, Met-enkephalin-Arg6-Phe7 and Leu-enkephalin was studied in human adrenal medulla and pheochromocytomas at the light and electron microscopic levels. Both adrenal medulla and pheochromocytomas (4 adrenal, 1 extra-adrenal) showed scattered or clustered cells which contained all of the above peptides and suggested the production of proenkephalin A. The presence of these peptides predominantly in the secretory granules suggested that proenkephalin A is processed to final products mainly in the secretory granules. The localization of Met-enkephalin-Arg6-Gly7-Leu8 and Met-enkephalin-Arg6-Phe7 in cisternae of rough endoplasmic reticula indicated their actual production in pheochromocytomas.     

Magnetic circular dichroism and spin equilibrium of methemoglobin and its subunits

The intensity of the Soret magnetic circular dichroism (MCD) spectra of various complexes of methemoglobin subunits (α⁺ and β⁺) as well as methemoglobin (metHb A) was correlated well with the spin states of ferric heme. Upon the subunit association, spin state transition toward higher spin was observed only in high spin derivatives and the changes in spin state were due to mainly those of β⁺ chains. The effect of an allostric effector, inositol hexaphosphate (IHP), on the MCD spectra of metHb A derivatives was observed much significantly for high spin forms than low spin ones.