Characterization of Avian Paramyxoviruses Isolated from Feral Ducks in Northern Japan: The Presence of Three Distinct Viruses in Nature

Seventy-eight strains of avian paramyxoviruses (PMV) were isolated from cloacal and/or tracheal swabs taken from 1,342 feral ducks, comprised of spot-bill ducks, mallards, pintails, teals, falcated teals, wigeons and buffie-heads, in Wakuya-cho, Miyagi Prefecture, Japan, between 1976 and 1979. Five and a half percent of the ducks were positive for virus. Serological and structural characterization indicated that three different avian paramyxoviruses arc prevalent in the Japanese feral duck population. The first group of PMV was Newcastle disease virus (NDV), and in vivo pathogenecity tests in embryonated chicken eggs and 1-day-old chicks revealed that all the NDV strains isolated were avirulent. The second and most prevalent strain was closely related to PMV-4, duck/Hong Kong/D3/75 strain. The viruses of the third group were recovered only from pintails. They cross-reacted antigenically with PMV-3 when antisera to the PMV-3 reference strains, turkey/Wisconsin/68 and parakeet/Netherlands/449/75, were employed. However, no cross-reaction was observed when antiserum to pintail/ Wakuya/20/78, the prototype of this group, was used. The viruses of the third group also differed in viral polypeptide profile from the reference strains of PMV-3.     

A novel opioid peptide, leumorphin, acts as an agonist at the kappa opiate receptor

The primary structure of the common precursor of porcine beta-neo-endorphin and dynorphin (preproenkephalin B) has shown the existence of a third leucine-enkephalin (leu-enkephalin) sequence with a C-terminal extension of 24 amino acids. This nonacosapeptide, named leumorphin, was approximately 70 times more potent than leu-enkephalin in inhibiting the contraction of the myenteric plexus-longitudinal muscle preparation of the guinea pig ileum. This action of leumorphin, like those of beta-neo-endorphin and dynorphin, was antagonized less effectively by naloxone than that of leu-enkephalin, but more effectively by Mr2266, an antagonist relatively specific for the kappa type opiate receptor. The inhibitory action of leumorphin or beta-neo-endorphin on the contraction of the guinea pig ileum muscle strip was reduced in a dose-dependent manner by pretreatment with dynorphin and vice versa. Leumorphin as well as beta-neo-endorphin and dynorphin inhibits the contraction of the rabbit vas deferens which is known to have only the kappa type opiate receptor. This action was also effectively antagonized by Mr2266. It is concluded that leumorphin has potent opioid activity and acts at the kappa receptor, like other opioid peptides derived from preproenkephalin B.     

Multi-scale spatial pattern of recruitment in the barnacles Semibalanus cariosus at fishing ports on the Kameda peninsula, southern Hokkaido, Japan

The potential causes of the variable nature of recruitment of marine organisms can be inferred from the scales over which they vary. Sampling for recruits of Semibalanus cariosus on the intertidal concrete tetrapods at 21 fishing ports along the Kameda Peninsula, southern Hokkaido, Japan, was conducted at the end of the recruitment season in 1994 at three spatial scales: at each fishing port, separated by several km; at two sites at each fishing port, separated by several hundred m; and on three blocks at each site, separated by 1–2 m. At all spatial scales, recruitment intensity was independent of adult densities. Recruitment densities significantly varied within all spatial-scales, however, 85.6% of the total variances was estimated to be due to variation among ports. Such km-scale variation of recruitment intensities coincided with the hydrographic pattern of the direction of coastal current.     

Further study on 1/f fluctuations observed in central single neurons during REM sleep

Recently, 1/f fluctuations have been discovered in the single-unit activity of mesencephalic reticular formation (MRF) neurons during REM sleep. In a previous paper, such behavior could satisfyingly be interpreted on the basis of the clustering Poisson process. The question of applicability of this model to other MRF neurons remained unanswered. The present paper reports on 1/f fluctuations in 12 MRF neurons all of which can satisfyingly be modeled by the clustering Poisson process.     

Characterization of Borrelia Species Isolated from Ixodid Ticks,Ixodes ovatus

Thirty-two Borrelia isolates were obtained from the adult stage of ixodid ticks, Ixodes ovatus, collected in various localities in Japan. Borrelial isolates were cultivated and analyzed by polyacrylamide gel electrophoresis, with monoclonal antibodies, by pulsed field gel electrophoresis, and by genomic Southern hybridization. All borrelial isolates showed similar protein profiles and monoclonal antibody reactivities, while plasmid profiles were rather diverse. Genomic hybridization using rRNA gene probes demonstrated the genetic similarities of those isolates. We found no significant differences among the borrelial isolates tested, and the restriction fragment length polymorphism patterns of I. ovatus isolates were quite distinct from those of borrelial strains associated with Lyme disease. Therefore, the isolates of Borrelia obtained from I. ovatus were thought to fall into different genospecies.