Effects of intravenous injection of Salmonella antigen on the distribution of major histocompatibility complex class II positive cells in the ovarian follicles of hens

The goal of this study was to determine whether the distribution of major histocompatibility complex class II positive (MHC class II+) cells was affected by foreign agents in the blood circulation. White Leghorn layers were injected intravenously with or without formalin fixed Salmonella paratyphi , and the area of MHC class II+ cells in the ovarian follicles, which included the largest (F1) and third largest follicles (F3), white follicles (WF) and cortical follicles, was examined by immunocytochemistry. The immunoreaction products for MHC class II were observed in cells of the thecal layer of all follicles in both treated and control birds. Salmonella paratyphi antigen caused a significant increase in the area of MHC class II+ cells in the theca of the F1, F3 and WF, but not in the cortical follicles. The results suggest that the MHC class II+ cells in the theca increase in response to circulating foreign agents, and play a significant role in ovarian local immunity.     

Mercury Speciation in the Water of Minamata Bay, Japan

The speciation of mercury (Hg) in Minamata Bay (Japan) was studied over a 2-year period (2006?C2008). Concentrations of dissolved total Hg, dissolved methylmercury (MeHg), particulate total Hg, and suspended solids were 0.43?±?0.14 ng/l (mean?±?standard deviation), 0.10?±?0.06 ng/l, 3.04?±?2.96 ng/l, and 5.94?±?2.10 mg/l, respectively. Correlations between concentrations of particulate total Hg and suspended solids at four depths (surface: 0 m; mid-depth: ?6 m, ?10 m; and bottom +1 m layer) were only significant in the bottom +1 m layer. The mean dissolved MeHg concentration and the ratio of dissolved MeHg to dissolved total Hg were considerably higher in summer compared to other seasons. The data suggest that bottom sediment was not the sole source of MeHg, and that MeHg may be produced in the water column by the conversion of divalent Hg eluted from resuspended bottom sediment. The correlation between seawater characteristics such as salinity, temperature, dissolved oxygen (DO), and dissolved MeHg concentration indicates that Hg methylation could be influenced by the heterotrophic activity of microorganisms in the seawater. In particular, inverse correlations were observed between DO, salinity, and MeHg concentration. However, dissolved MeHg concentrations did not correlate with seawater characteristics such as pH or chlorophyll-a.     

Bi-directional sex change and its steroidogenesis in the wrasse, Pseudolabrus sieboldi

The protogynous wrasse, Pseudolabrus sieboldi, is a good model for studying the physiological mechanism of sex change in teleosts. We established a way to induce sex change bidirectionally by controlling the social conditions in captivity. This is the first report of a reversed sex change in a promiscuous species. After identifying all the steroid hormones produced in the ovarian follicles and testis, and clarifying their synthetic pathways, we examined the function of the sex steroids in the sex change of P. sieboldi. We concluded that the activation of 17β-HSD-III is the first step in inducing morphological and functional change from an ovary to a testis.     

GnRHa-induced spawning of wild-caught jack mackerel Trachurus japonicus

The jack mackerel Trachurus japonicus is a key commercially exploited fish species in Japan. The rearing experiment often provides information that is useful for understanding the reproductive characteristics of wild stocks; however, there has been no study on spawning in captive T. japonicus. In the study reported here, we induced spawning in T. japonicus caught in the wild by hook and line. Females with fully vitellogenic oocytes and males during spermiation were selected by gonadal biopsy and injected with gonadotropin-releasing hormone analog (GnRHa) mixed in molten coconut butter. This treatment was performed four times in different groups of four females and five to eight males, and each group was maintained in a 3-m³ concrete tank. We observed the first spawning at 1 or 2 days post-injection and collected between 41,690 and 149,450 eggs. Spawning was recorded on 18 consecutive days in one experiment and for 3 days continuously in the other experiments. In the former, spawning ended when the water temperature reached 23 °C and occurred mainly between 2100 and 2400 hours. These results indicate that GnRHa-induced spawning may be useful for evaluating the reproductive characteristics of T. japonicus and obtaining fertilized eggs to conduct larval experiments.     

Horizontal and vertical variations in survival rates of juvenile bivalves,Anadara kagoshimensis (Tokunaga, 1906), Ruditapes philippinarum (Adams & Reeve, 1850) and Atrina sp., experimentally caged in the inner area of the Sea of Ariake,Japan

International Aquatic Research - In the inner area of the Sea of Ariake, rearing experiments were conducted to examine how the survival rates of juveniles of three bivalve species (Anadara...     

Treatment of myeloid neoplasia with doxorubicin and cytarabine in 11 dogs

Myelodysplastic syndrome (MDS) and acute myeloid leukaemia (AML) are primary myeloid neoplasms in dogs generally considered to have a poor outcome. In this study, we assessed toxicity, efficacy and outcome of concurrent administration of doxorubicin and cytarabine in 11 dogs with myeloid neoplasia. Bone marrow specimens were reviewed by three pathologists and classified as either MDS (n = 2), high grade MDS/early AML (MDS/AML; n = 4) or AML (n = 5). The median number of treatment cycles was 5 (range 1–9) and resolution of cytopenia was reported in 7 of 11 dogs including 2 dogs with MDS, 2 dogs with MDS/AML, and 3 dogs with AML. The median duration of remission in the seven responders was 344 days (range 109–1428) and the median overall survival for all dogs was 369 days. Adverse events consisted of predominantly low-grade gastrointestinal illness and myelosuppression. Three dogs developed grade V toxicity manifesting with heart failure (n = 2) at 369 and 1170 days after diagnosis and acute gastrointestinal side effects (n =1). Despite a limited sample size, these results suggest that a doxorubicin and cytarabine protocol may be considered as a therapeutic option in dogs with myeloid neoplasia. Protocol safety, in particular regarding myocardial toxicity, and efficacy should be further investigated.     

Lactation and digestion in dairy cows fed ensiled total mixed ration containing steam‐flaked or ground rice grain

The objective of this experiment was to investigate the effect of feeding ensiled total mixed ration (TMR) containing steam‐flaked (SF) or ground brown rice (Oryza satira L.; BR) on feed intake, lactation performance, digestion, ruminal fermentation and nitrogen (N) utilization in dairy cows. Eight multiparous Holstein cows were used in a crossover design with two dietary treatments: diets containing either SF or fine ground (FG) BR at 24% of dietary dry matter. Dietary treatment did not affect dry matter intake or milk yield and composition. The whole‐tract digestibility of organic matter and fiber decreased, and the digestibility of starch increased with the replacement of SF with FG in ensiled TMR, but these differences were small between diets. Crude protein digestibility was not different between diets. The processing method of BR did not affect ruminal pH, total volatile acid concentration, or volatile fatty acid proportion in cows. The N intake, milk N secretion, fecal and urinary N excretion and N retention were not influenced by dietary treatment. These results show that feeding ensiled TMR containing FG instead of SF reduces fiber digestibility but has little impact on lactation and N utilization when diets contained 24% on a dry matter basis.     

Isolation and sequence analysis of the promoter and an allelic sequence of the iron-sulfur protein subunit gene from the white-rot fungusPleurotus ostreatus

We have isolated a structural gene ofsdil, which encodes the iron-sulfur protein (Ip) subunit of succinate dehydrogenase (EC 1.3.99.1), from a white-rot basidiomycete,Pleurotus ostreatus. Here we report isolation of the promoter region ofsdil and an allelic sequence encoding the second-type cDNA fragment isolated in the former experiments. The nucleotide sequence analysis of the promoter region revealed the existence of putative CAAT and TATA boxes, which permits us to develop an expression system in this species. The Southern blot analysis and the restriction fragment length polymorphism assay using monokaryotic strains demonstrated that no family genes tosdil exist in the haploid genome ofP. ostreatus. Moreover, a genetic analysis to detect a linkage between thesdil genotypes and flutolanil resistance in the mutantP. ostreatus strains was also developed.     

Effects of irradiance of various wavelengths from light-emitting diodes on the growth of the harmful dinoflagellate <Emphasis Type="Italic">Heterocapsa circularisquama</Emphasis> and the diatom <Emphasis Type="Italic">Skeletonema costatum</Emphasis>

ABSTRACT:   We investigated the effects of specific light wavelengths from light-emitting diodes (LEDs) on the growth of the dinoflagellate Heterocapsa circularisquama , which kills bivalves, and the diatom Skeletonema costatum , which is an important food source for bivalves. Growth of H. circularisquama was obviously inhibited at 590 nm and a photon flux density less than 75 μmol quanta/m²/s. However, growth of S. costatum was not suppressed by irradiance from any LEDs tested from near-ultraviolet to near-infrared wavelengths at 75 μmol quanta/m²/s. The growth rate of H. circularisquama in an experimental treatment group with irradiance provided by both cool-white fluorescent lamps (12:12 h L : D cycle) and a 590-nm LED (continuous irradiance) was 0.43/day. In the control group with irradiance provided only by cool-white fluorescent lamps (12:12 h L : D cycle), the growth rate was 0.63/day, indicating that growth of H. circularisquama was suppressed by 590 nm (less than 75 μmol quanta/m²/s) irradiance from the LED and the continuous irradiance. The use of 590-nm LEDs in bivalve culture at irradiance levels less than 75 μmol quanta/m²/s might encourage the growth of the useful diatom S. costatum without stimulating growth of the harmful dinoflagellate H. circularisquama .