Phenotype and function of murine peritoneal cavity macrophage derived-dendritic cells

The accessory activity was reported in murine peritoneal cavity macrophage derived dendritic cells (PEC-DC) in a mixed lymphocyte reaction (MLR). Here we continue the characterization of the generated PEC-DC using the criteria of morphology, phenotype and other accessory function. We have demonstrated that murine peritoneal cavity macrophages can be induced to differentiate in vitro into cells exhibiting typical dendritic cell (DC) morphology, phenotype and function. The proliferative capacity of the progenitors was amplified in the first step of the culture (day 0-7) using a combination of early cytokines: interleukin 4 and granulocyte-macrophage colony-stimulating factor. The second step of the culture started at day 7 with the removal of early growth factors to allow differentiation and final maturation of DC during 2 days of culture with interferon gamma plus either Toxoplasma lysate antigen (TLA) or lipopolysaccharide (LPS), a bacterial agent as a DC maturing agent. The resulting DC population exhibited typical DC morphology and expressed higher levels of MHC class II and the co-stimulatory molecules CD80 and CD86 compared to the untreated peritoneal cells. The generated DC cells efficiently presented soluble protein antigen to CD3(+) spleen T cells.     

Serum leptin levels during the periparturient period in cows

Serum leptin concentrations were measured in antenatal and postnatal cows housed at two different locations. The mean serum leptin concentration was 9.2 +/- 0.6 ng/m l (n=22) in one group, and was slightly lower in the other (7.4 +/- 0.4 ng/ml, n=54), probably because of the different nutritional conditions between the two groups. There was no consistent variation in relation to the menstrual cycle and the periparturient period in both groups. Moreover, serum leptin concentrations during the periparturient period were independent of the number of delivery and the incidence of mastitis and milk fever. These results are quite different from those in rodents and human, suggesting the different regulatory mechanism of circulating leptin concentration in cows.     

Relationships between the conception rate of estrus synchronization using estradiol benzoate and CIDR (progesterone) and other parameters in holstein lactating dairy cows

The purpose of this study was to determine the relationships between conception rate and other parameters before estrus synchronization with a Controlled Internal Drug Release Device (CIDR) and estradiol benzoate (EB). In the estrus synchronization program, animals were injected with 2 mg EB and then received a CIDR. Seven days later, the CIDR was removed and the animals were given an injection of Prostaglandin F(2alpha). Twenty-four hours later, they received an injection of 1 mg EB, and they were artificially inseminated 24 h after that. This program was applied to 258 Holstein cows in Tohoku-machi (Aomori, Japan). Blood was collected at the beginning of the program, and the conception rate was determined about 40 days after insemination. The relationships among conception rate, blood biochemical values, age, body condition score and days in milk were statistically analyzed to determine better conditions for cow conception. The conception rate of the cows in the high progesterone group (more than 1 ng/ml, P(4)+) was significantly higher than that of the low progesterone group (less than 1 ng/ml, P(4)-; 47.9% vs. 28.6% P<0.01). In the P(4)- groups, the serum phospholipid level was significantly higher in the conception group than in the non-conception group, and the same tendency was seen in the P(4)+ groups. Blood urea nitrogen (BUN), albumin (Alb), and total cholesterol (TChol) were significantly higher in the conception group compared with the non-conception group, but no with P(4) was observed. We concluded that 1) the conception rate of the P(4)- group was remarkably low, that 2) the low conception rate and low P(4) level was related to a low PL level and that 3) BUN, Alb and TChol were higher in the conception group, although no relation with P(4) was found.     

Surveillance of avian influenza viruses in Northern pintails (Anas acuta) in Tohoku District, Japan

Among winter migratory waterfowl, Northern pintails (Anas acuta), in one of the largest flocks in Tohoku district, northeast Japan, were surveyed for influenza A viruses at five wintering sites in three prefectures, viz., Aomori, Akita, and Miyagi. A total of 38 influenza A viruses were isolated from 2066 fecal samples collected during November 2006 through March 2007. The overall isolation rate was 1.84%. Eleven different subtypes were isolated, including nine H5N2, seven H6N8, seven H10N1, four H4N6, three H6N1, three H11N9, and one each of H1N1, H6N2, H6N5, H10N9, H11N1. Only the H4N6 subtype was detected during two successive months, November and December, from Lake Ogawara of Aomori prefecture. One wintering site, Lake Izunuma of Miyagi prefecture, was negative for virus isolation throughout the study period. During the sampling period, the highest virus isolation rate was in December (4.90%) followed by November (2.18%), January (0.91%), and February (0.30%). Virus isolation was negative for samples collected in March 2007. These results suggest that influenza viruses are introduced by Northern pintail when they migrate into Japan, but the viruses are not maintained in the flocks, most likely because the birds are not breeding during the winter. We believe that this relatively large data set creates a strong foundation for future studies of avian influenza virus (AIV) prevalence, evolution, and ecology in wintering sites, along with the role of Northern pintails in the spread of AIV during their migration from northern Russia and Asia to Japan.     

Differences in longitudinal distribution patterns along a Honshu stream of brown trout <Emphasis Type="Italic">Salmo trutta</Emphasis>, white-spotted charr <Emphasis Type="Italic">Salvelinus leucomaenis</Emphasis> and masu salmon <Emphasis Type="Italic">Oncorhynchus masou</Emphasis>

Brown trout Salmo trutta were first introduced into Japan in 1892, and they currently naturally reproduce in several rivers in Honshu and Hokkaido, Japan. Although negative impacts of brown trout introductions on native salmonid fishes have been documented in some Hokkaido rivers, studies of ecological interactions between brown trout and native salmonid fishes on Honshu are limited. In this study, we describe the longitudinal distribution patterns of introduced brown trout, white-spotted charr Salvelinus leucomaenis and masu salmon Oncorhynchus masou in a 4 km stretch of a stream in central Honshu. Underwater observations were conducted in all pools within upstream, middle and downstream sections (190–400 m in length) of this stretch in order to estimate the densities of these species. Only white-spotted charr was observed in the upstream section, while brown trout and masu salmon were observed in the middle and downstream sections. Masu salmon densities, however, were much lower than brown trout densities. In the downstream section, white-spotted charr was absent. These results are consistent with results from previous studies of Hokkaido rivers, where it was found that white-spotted charr in low-gradient areas tend to be displaced by brown trout.     

Confirmation of yessotoxin production by the dinoflagellate <Emphasis Type="Italic">Protoceratium reticulatum</Emphasis> in Mutsu Bay

ABSTRACT:   Yessotoxin (YTX) is a shellfish toxin and its contamination in bivalves has seriously damaged shellfish industries. The biogenetic origin of YTX was identified as the dinoflagellate Protoceratium reticulatum (Claparède et Lachmann) Bütschli collected in New Zealand and Yamada Bay, Iwate in Japan. Scallops cultured in Mutsu Bay, Japan, were frequently contaminated with YTX, however, occurrence of P. reticulatum in this bay and YTX production by the local strains have not been investigated. Eight strains of P. reticulatum , isolated from the bay, were cultured in the laboratory, and analyzed by fluorometric high-pressure liquid chromatography and liquid chromatography/mass spectrometry methods for YTX production and composition. All strains tested were confirmed to produce YTX, and none of them produced known YTX analogs. Toxin amount and composition differed from strain to strain. This result is also confirmation of one of the biogenetic origins of YTX in Mutsu Bay.     

Comparison of behavioral responses to a novel environment between three teleosts,bluegill <Emphasis Type="Italic">Lepomis macrochirus</Emphasis>, crucian carp <Emphasis Type="Italic">Carassius langsdorfii</Emphasis>, and goldfish <Emphasis Type="Italic">Carassius auratus</Emphasis>

To investigate the emotional reactivity of fish in a novel environment, the swimway test was developed. The swimway apparatus consists of a shaded start chamber and an open, illuminated swimway. Fish were first introduced and habituated to the start chamber. A door partitioning the start chamber from the swimway was then opened, and behavioral responses of the fish in the apparatus were measured. By using the swimway test, behavioral responses to a novel environment of bluegill Lepomis macrochirus, crucian carp Carassius langsdorfii, and goldfish Carassius auratus were quantified and compared. The emotional reactivities in blue gill were found to be the lowest and crucian carp the highest, indicating bluegill are relatively active or ‘bold’, and that the crucian carp are relatively passive or ‘shy’, in a novel environment. It is suggested that the swimway test is applicable to examning inter-species differences in relative emotional reactivity or boldness in a simplified novel situation.     

Plasma concentration of vitamin C in dogs with a portosystemic shunt

Most mammals, including dogs, synthesize vitamin C in the liver. We measured the plasma concentration of vitamin C to assess the body vitamin C status in 15 dogs with a portosystemic shunt (PSS). The plasma biochemical parameters indicated liver abnormalities in all the dogs. In contrast, the plasma concentration of vitamin C ranged from 2.21 to 9.03 mg/L in the 15 dogs and was below the reference range (3.2 to 8.9 mg/L) in only 2 dogs. These findings suggest that vitamin C status is not impaired in dogs with PSS.     

Adrenocortical responses to tumor necrosis factor-alpha and interferon-gamma in cattle

The responses of plasma cortisol and adrenocorticotropic hormone (ACTH) were examined to intravenous injection of recombinant bovine tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (INF-gamma) in Holstein cows. INF-gamma induced dose-dependent rises in the plasma levels of both cortisol and ACTH, while TNF-alpha induced comparable plasma cortisol responses with much smaller rises in plasma ACTH. The results suggest a direct stimulatory action of TNF-alpha on cortisol secretion from the adrenal gland in cattle.     

Identification of the feline CD63 homologue using retrovirus-mediated expression cloning

Recently, we combined a retrovirus-mediated expression cloning with a simple screening method using non-adherent cells and panning [Anal. Biochem. 315 (2003) 138]. In this study, we applied this method to identify the antigen recognized by an uncharacterized monoclonal antibody raised against a feline cell line, and identified it as the feline homologue of CD63. This simple method is useful for characterizing unknown antibodies that recognize cell surface molecules. Furthermore, the monoclonal antibody identified as an anti-feline CD63 antibody will be useful for studying feline molecular function(s).