Bioremediation of organically enriched sediment deposited below fish farms with artificially mass-cultured colonies of a deposit-feeding polychaete <Emphasis Type="Italic">Capitella</Emphasis> sp. I

ABSTRACT:   For bioremediation of organically enriched sediment deposited below fish farms, the extremely high potential for population growth of a deposit-feeding polychaete, Capitella sp. I, in the organically enriched sediment, and the effect on decomposition of organic matter in the sediment, were examined. A mass-culturing technique was conducted for this species. Bioremediation experiments were conducted on the organically enriched sediment in a fish farm in Kusuura Bay, Japan in 2003–2006. Approximately 1.7 million individuals of the worms were placed on the sediment below one net pen in December 2003, 9.3 million individuals in November 2004, and 2.2 million individuals in November 2005. After the worms were spread on the sediment, they rapidly increased in number and reached the highest densities of approximately 134 000 inds/m² in February 2004, 527 000 inds/m² in March 2005 and 103 000 inds/m² in January 2006. In the process of rapid population growth, the decomposition of the organic matter of the sediment was enhanced markedly. Our results demonstrate that the promotion of population growth by spreading cultured colonies of Capitella can enhance the decomposition rate of organic matter markedly in organically enriched sediment below fish farms. This method is promising for minimization of the negative effects of fish farms.     

Protective Effect of Stachybotrys microspora Triprenyl Phenol-7on the Deposition of IgA to the Glomerular Mesangium in Nivalenol-induced IgA Nephropathy Using BALB/c Mice

Activators of tissue proteolysis including Stachybotrys microspora triprenyl phenol (SMTP)-7 are a new class of agents that are expected to be effective for amelioration of chronic tissue destructive diseases. The present study was performed to examine whether SMTP-7 is effective for the amelioration or protection of early-stage IgA nephropathy (IgAN) induced by nivalenol (NIV) in female BALB/c mice. In Experiment 1, mice were administered NIV at 24 ppm in diet for 8 weeks, and during the NIV treatment, they were intraperitoneally injected with SMTP-7 (10 mg/kg) three times a week. In Experiment 2, mice were injected similarly with SMTP-7 during the last 4 weeks of a 16-week NIV treatment. Immunofluorescence analysis revealed an inhibitory effect of SMTP-7 on the glomerular deposition of IgA in Experiment 1; however, it was ineffective in Experiment 2. On the other hand, SMTP-7 did not affect the serum concentration of IgA in both experiments. These results suggest that SMTP-7 has a potential to decrease the progression of IgAN induced by NIV through inhibition of local accumulation of IgA in the glomerular mesangium, while it was ineffective for suppression of IgA production. On the other hand, SMTP-7 was found to be ineffective for already deposited IgA, suggesting that SMTP-7 may not be effective for ameliorating advanced IgAN.     

Myogenetic oligodeoxynucleotide complexed with berberine promotes differentiation of chicken myoblasts

Myoblasts are myogenic precursors that develop into myotubes during muscle formation. Improving efficiency of myoblast differentiation is important for advancing meat production by domestic animals. We recently identified novel oligodeoxynucleotides (ODNs) termed myogenetic ODNs (myoDNs) that promote the differentiation of mammalian myoblasts. An isoquinoline alkaloid, berberine, forms a complex with one of the myoDNs, iSN04, and enhances its activities. This study investigated the effects of myoDNs on chicken myoblasts to elucidate their species-specific actions. Seven myoDNs (iSN01–iSN07) were found to facilitate the differentiation of chicken myoblasts into myosin heavy chain (MHC)-positive myotubes. The iSN04–berberine complex exhibited a higher myogenetic activity than iSN04 alone, which was shown to enhance the differentiation of myoblasts into myotubes and the upregulation of myogenic gene expression (MyoD, myogenin, MHC, and myomaker). These data indicate that myoDNs promoting chicken myoblast differentiation may be used as potential feed additives in broiler diets.     

An estuarine neritid gastropod, Clithon corona, a potential reservoir of thermostable direct hemolysin-producing Vibrio parahaemolyticus

An estuarine neritid gastropod, Clithon corona, maintained in UV-irradiated recirculating artificial seawater with a salinity of 15 per mil (%o) was found to retain thermostable direct hemolysin (TDH)-producing Vibrio parahaemolyticus in the gut at significantly higher levels than TDH-non-producing one for at least 14 days. Another estuarine neritid gastropod, C. sowerbianus, was not able to support the preferential survival of TDH-producing organisms. This evidence suggests that, if TDH-producing vibrios are brought to estuaries inhabited by C. corona, repeated ingestion of V. parahaemolyticus by this gastropod could lead to accumulation of TDH-producing vibrios in the estuaries.     

Mice cloned by nuclear transfer from somatic and ntES cells derived from the same individuals

The current success rate of cloned mice from adult somatic cell nuclei is very low, whereas it is relatively high for cloned mice from ES cell nuclei. In this experiment, we examined whether the success rate of cloning from somatic cells could be improved via nuclear transfer embryonic stem cells (ntES cells) established from somatic cell nuclei. We obtained 11 cloned mice and 68 ntES cell lines from the somatic cell nuclei of 7 mice, and cloned 41 mice were cloned from the ntES cell nuclei. Unexpectedly, the overall success rate of cloning from ntES cell nuclei in this series was no better than when using somatic cell nuclei. Interestingly, full-term cloned mice were produced only via ntES cells from two individuals, but not by direct nuclear transfer from the somatic cells, and vice versa. Ultimately, we were able to obtain clone mice from 6 out of 7 individuals using either somatic cells or ntES cells. Thus, although ntES cells as donor nuclei do not absolutely assure a better success rate for mouse cloning than somatic cells, to preserve and clone valuable individuals, we recommend that ntES cell lines be established. These can then be used as an unlimited source of donor nuclei for nuclear transfer, and thus complement conventional somatic cell nuclear transfer cloning approaches.     

Sequences and polymorphisms of the canine monoamine transporter genes SLC6A2, SLC6A3, and SLC6A4 among five dog breeds

Monoamine transporters have roles to regulate the monoamine concentrations in synaptic clefts in the central nervous system and are the targets of antidepressants and psychostimulants. They include transporters for norepinephrine, dopamine and serotonin, which are encoded by the SLC6A2, SLC6A3, and SLC6A4 genes, respectivily. We sequenced the full lengths of the coding regions of these genes for dogs and identified four single nucleotide polymorphisms (SNPs) in SLC6A2 and four in SLC6A3. One SLC6A3 SNP was non-synonymous and caused an amino acid substitution from threonine to serine. The genotype frequencies of these polymorphisms differed significantly among five breeds with different behavioral traits, suggesting that novel SLC6A2 and SLC6A3 SNPs would provide additional useful information for behavioral genetic studies in dogs.     

Clinical oral doses of dexamethasone decreases intrinsic clearance of quinidine, a cytochrome P450 3A substrate in dogs

We investigated the effect of dexamethasone (DEX) at clinical doses on the pharmacokinetics of quinidine (QN) in dogs. Dogs (5 healthy 1-year-old male beagles) were orally administered DEX once daily for 5 days at 2.5 or 7.5 mg/day. QN (2 mg/kg) was intravenously injected 3 weeks before and one day after the DEX treatment. The plasma concentration of QN was determined by high-performance liquid chromatography with fluorometric detection. Plasma concentrations of albumin and alpha(1)-acid glycoprotein (AGP) were determined by a bromocresol green method and a single immunodiffusion method, respectively. In order to calculate unbound concentrations of QN in plasma, the binding kinetics of QN in plasma was examined by an ultrafiltration method using pooled plasma from the 5 dogs when they were drug-free. Total body clearance of QN was decreased dose-dependently By the DEX treatment, although the decrease was not statistically significant. Elimination half-lives significantly increased (more than twice at 7.5 mg), and intrinsic clearance significantly decreased (about 50%). The volume of distribution increased significantly (about two-fold). Plasma levels of AGP significantly decreased, and the unbound fraction of QN in plasma significantly increased. Our results demonstrate that clinical doses of DEX significantly affect the pharmacokinetics of QN, a CYP3A substrate in dogs, by decreasing CYP3A activity and plasma AGP levels. There is a possibility that adverse drug-drug interaction occurs during DEX therapy through its effects on CYP3A activity and plasma AGP levels.     

Radiographic evaluation of caudal vena cava size as a useful parameter for the diagnosis of heart disease in dairy cattle

To quantify the radiographic parameters of the caudal vena cava (CVC) in healthy cattle and demonstrate their clinical usefulness, the present study compared the ratios of the diameter of the thoracic CVC to the diameter of the aorta (Ao) and length of the thoracic vertebrae (VL), which are all positioned in the same intercostal space, in 81 healthy control cattle (43 growing, 38 adult) and 10 cattle with heart disease. The average diameter of the CVC (CVCave) was correlated with the size of the Ao and VL in the control cows. Although the diameter and pulsation index of the CVC differed significantly between the growing and adult cows, the ratios of CVC/Ao and CVC/VL were fixed values for both the growing and mature cattle. However, in the cattle with heart disease, the pulsation index of the CVC was significantly lower or there was absence of pulsation due to a dilated CVC, and the ratio of CVCave/Ao and CVCave/VL were significantly higher than those in the healthy cattle.     

Endocrine mechanisms responsible for different follicular development during the estrous cycle in Hatano high- and low-avoidance rats

Hatano high- and low-avoidance rats (HAA and LAA strains, respectively) were selected and bred according to the avoidance rate in a shuttle-box task. Although they have clear strain differences in ovarian function, their endocrine mechanisms still remain to be clarified. Differences in female reproductive endocrinology between the strains were investigated by means of measuring the plasma concentration of reproductive hormones during the estrous cycle. LAA rats showed approximately threefold lower basal and surge levels of LH, a more than fourfold lower level of FSH surges and higher levels of inhibin A and inhibin B during the estrous cycle compared with the levels seen in HAA rats. The concentration of estradiol-17β in the proestrous stage was significantly lower in LAA rats than in HAA rats. Additionally, LH and FSH secretions from primary cultured anterior pituitary cells with or without in vitro GnRH stimulation were lower in the cells derived from LAA rats and, in terms of FSH secretion, were unresponsive to GnRH in contrast to cells derived from HAA rats. Although an increased number of preantral follicles in diestrus were observed in LAA rats, number of hCG-induced ovulation was lower in LAA rats. LAA rats may have much more follicle growth during the early stage of folliculogenesis, but most follicles might not grow into mature follicles. These results strongly suggest that the strain difference in ovarian function of these two Hatano rats is due to the difference in the regulation of hypothalamo-hypophyseal system for gonadotropins secretion.