Accumulation of organotin compounds and marine birnavirus detection in Korean ascidians

ABSTRACT:   Recently, a serious disease spread extensively in aquaculture sites of the ascidian Halocynthia roretzi in Korea. To understand circumstances of ascidians in Korean aquaculture sites, residue levels of organotin compounds were analyzed, and detection of a marine birnavirus (MABV) in tissues of H. roretzi was attempted. Korean H. roretzi showed high concentrations of butyltins (mono, di, and tributyltins), especially in the gill, hepatopancreas, and digestive tract. However, there was no significant difference in the residues of butyltins in the hepatopancreas between diseased and non-diseased ascidians. The positive rate of MABV detection was high in the hepatopancreas, but also no significant difference was observed between diseased and non-diseased individuals. These observations suggest that an accumulation of tributyltin and a latency of MABV in H. roretzi tissues does not directly relate to the occurrence of the disease.     

Interspecific variations in age and size at settlement of 8 emperor fishes (Lethrinidae) at the southern Ryukyu Islands,Japan

Molecular and otolith analyses were conducted for 173 settlement-stage larvae of emperor fishes (family Lethrinidae) collected by light traps at Ishigaki Island, southern Japan, in July and August (summer season), to (1) present diagnostic DNA markers for identification of lethrinid species and (2) compare the size and age at settlement of each species. PCR–RFLP and direct nucleotide sequencing analyses identified 8 species. Size (standard length, SL) at settlement differed significantly between species; Lethrinus ornatus (mean SL ± SD, 12.8 ± 1.5 mm), L. obsoletus (14.2 ± 0.8 mm) and L. harak (15.8 ± 1.6 mm) settled at a smaller size than L. atkinsoni (17.0 ± 1.3 mm), L. genivittatus (17.3 ± 1.0 mm), L. olivaceus (18.1 ± 0.6 mm), L. nebulosus (18.6 ± 4.2 mm), and L. sp.2 reported by Lo Galbo et al. (J Mol Evol 54:754–762, 2002) (21.7 ± 1.4 mm). Age at settlement tends to increase with settlement size; L. obsoletus (mean age ± SD, 25.6 ± 1.2 days), L. atkinsoni (26.1 ± 2.1 days) and L. ornatus (26.3 ± 2.9 days) were younger at settlement than L. nebulosus (28.4 ± 2.1 days), L. harak (29.2 ± 1.7 days), L. olivaceus (29.5 ± 1.0 days), L. genivittatus (30.5 ± 1.7 days) and L. sp.2 (31.0 ± 2.0 days). Although our study showed interspecific variation in body size and age at settlement among 8 lethrinid species, further seasonal replication is necessary to clarify the general patterns.     

Assessment of the decay risk of airborne wood-decay fungi III: decay risks at different sampling sites

The decay risk of airborne wood-decay fungi in the same volume of air was investigated by using an air sampler over the course of a year at three different sampling sites. Japanese cedar disks measuring 7.8 cm in diameter and about 3 mm in thickness, and with a moisture content of about 100 % were placed in a “BIOSAMP” air sampler and then exposed to 1000 l of air in the northern, central, and southwest parts of Japan. The exposed disks were incubated for 20 weeks in a damp container maintained at 26 ± 2 °C and degraded by fungi trapped on the disks. The decay risk was calculated from the mass loss during incubation, and the factors affecting the said risk were explored. The results showed that sampling sites apparently do not affect decay risk, even though the Scheffer’s climate indexes of the sites were quite different. The relation between the sampling month and decay risk reveals that decay risk remains virtually the same year-round. Relative humidity on a sampling day is one of the key factors affecting decay risk in sampling conducted at the central or southwest site. In contrast, no weather factors influenced decay risk at the northern sampling site.     

Pathological changes of tracheal mucosa in chickens infected with lentogenic Newcastle disease virus

Forty-day-old specific-pathogen-free chickens were exposed by aerosol to lentogenic Newcastle disease virus (NDV) and observed for 24 days for pathological changes in the tracheal mucociliary system. Specific fluorescence of NDV antigen was observed through day 5 postexposure (PE) in the cytoplasm of the tracheal epithelium and desquamated epithelium in the lumen. On day 1 PE, scanning electron microscopy revealed hypertrophy of goblet cells and small patches of the deciliated epithelium scattered mainly around the openings of mucous glands. The deciliated area of tracheal surface increased through day 4 PE. Light microscopy showed small vacuoles containing lymphocytes and heterophils in the epithelial layer. Immature epithelium proliferated in some areas. On days 5 and 6 PE, ciliated areas of the trachea tended to increase as a result of regeneration of the epithelium, still leaving many nonciliated patches of various sizes. On and after day 8 PE, there remained plaques with nonciliated flat epithelium, but most areas were covered with well-ciliated epithelium. Non-ciliated plaques were observed until day 24 PE, but they gradually decreased in size. These plaques were covered by a single layer of flat epithelium and were formed upon lymph follicles in subepithelial tissue.     

Escherichia coli multiplication and lesions in the respiratory tract of chickens inoculated with infectious bronchitis virus and/or E. coli.

Escherichia coli numbers and histopathological changes were studied in the respiratory tract of line 151 chickens intranasally inoculated with infectious bronchitis virus (IBV) and/or virulent E. coli; this line is highly susceptible to IBV. Chickens inoculated with IBV alone showed increased numbers of E. coli in the trachea and had tracheitis, airsacculitis, and bronchiolitis. One of 17 chickens inoculated with IBV alone died with fibrinopurulent serositis. Chickens inoculated with IBV and E. coli had more severe and persistent respiratory lesions than those inoculated with IBV alone. E. coli was isolated from tracheas of chickens inoculated with IBV and E. coli more frequently than from chickens inoculated with IBV alone. In this group, 14 of 27 chickens died with tracheal plugs or with fibrinopurulent serositis. There was neither increased numbers of E. coli nor significant lesions in the respiratory tract of the group inoculated with E. coli alone. These results suggest that IBV may facilitate E. coli invasion into the lower respiratory tract of the chicken.     

Effect of parthenocarpy,peeling and fruit age on the changes in volume and specific gravity of cucumber fruits during storage at 20°C

Either parthenocarpically grown, peeled or at any stage of picking, cucumber fruits showed a tendency to increase in volume and decrease in specific gravity while they were stored under unsaturated vapour pressure at 20°C. The amount of change varied according to the treatment.Recovery from a flaccid appearance occurred in all fruit except very young ones. In those fruits the incipient recovery from wilting, an increase in volume and a decrease in specific gravity, coincided.Parthenocarpic fruits showed an increase in volume at almost the same rate in any transverse quarter of a fruit, in contrast to the pollinated ones in which the most distal quarter enlarged more than the other parts. Pithy appearance of the fruit wall was evenly distributed through a parthenocarpic fruit to a moderate degree, but at the proximal half of a pollinated one it was severe.     

Inhibitory effect of several fluoroquinolones on hepatic microsomal cytochrome P-450 1A activities in dogs

We examined inhibitory effects of ofloxacin (OFX), orbifloxacin (OBFX), ciprofloxacin (CFX), enrofloxacin (EFX) and norfloxacin (NFX) on cytochrome P-450 1A (CYP1A) activities using hepatic microsomes from four beagle dogs. Ethoxyresorufin O-de-ethylation was referred as CYP1A activities. All the fluoroquinolones inhibited the reaction in a noncompetitive manner. The determined inhibitory constants were the followings; 10.1 +/- 3.8 mM for OFX, 6.43 +/- 2.01 mM for OBFX, 0.726 +/- 0.134 mM for CFX, 4.06 +/- 1.19 mM for EFX and 4.75 +/- 1.63 mM for NFX respectively. As these values are >100-fold of plasma concentrations after a clinical single dose of the fluoroquinolones, it is suggested that the inhibitory effect on CYP1A activities is not so high to elicit drug-drug interaction with CYP1A substrates, when these fluoroquinolones are co-administered. Mechanism based inhibition was also examined in this study. Of the five fluoroquinolones examined, OFX, OBFX and CFX had this inhibition manner. As this inhibition is irreversible, inhibitory effects of the three fluoroquinolones may accumulate, when they are repeatedly administered. Therefore, OFX, OBFX and CFX may result in substantial drug-drug interaction with a CYP1A substrate even in clinical states. As EFX is metabolized to CFX in the body, it may also have the same possibility.     

N-acetylglucosaminyltransferase I activity of bovine oviduct epithelial cells: stimulation by luteinizing hormone, vascular endothelial growth factor and tumor necrosis factor alpha

N-acetylglucosaminyltransferase I (GnT I; EC 2.4.1.101), which catalyzes the first step in the conversion of oligomannose to complex or hybrid N-glycans of glycoproteins, was found in media cultured with bovine oviduct epithelial cells (BOEC) obtained from non-pregnant cows during the follicular phase. Combined treatment with specific hormones increased GnT I release from BOEC. Luteinizing hormone (LH; 10 ng/ml) alone slightly, but together with 17beta-estradiol (E2; 1 ng/ml), synergistically increased GnT I activity. Vascular endothelial growth factor (VEGF) and tumor necrosis factor (TNF) alpha, which have been shown to have their highest activities in the bovine oviduct during the periovulatory period, also increased in GnT I activity. This study provides the first evidence of an increase of GnT I release from BOEC in vitro, and shows that endocrine as well as local factors such as LH, VEGF and TNFalpha increase this activity. The results suggest that GnT I activity in the bovine oviduct may contribute to the induction of glycosylation and thereby contributing to the provision of the optimal microenvironment for fertilization and early development of the embryos.