Comparison of virulence of various hantaviruses related to hemorrhagic fever with renal syndrome in newborn mouse model

The virulence of hantaviruses that are antigenically related but have different genetic characteristics from the prototype of hantavirus, Hantaan (HTN) virus, was examined in newborn mice. The H5 and B78 strains of the Amur (AMR) genotype, the Bao14 strain of the Far East (FE) genotype, and the 76-118 strain of HTN virus were inoculated subcutaneously (1focus-forming unit; FFU) into newborn mice. All of the AMR and FE genotype viruses inoculated mice were died by 16 days post-infection (dpi) and 21 dpi, respectively, while 50% of the HTN virus inoculated mice survived until 30 dpi. The AMR and FE genotype viruses inoculated mice had high viral titers in the lung (1.3x10(6) to 1.3x10(8) FFU/gram [g] tissue) , brain (2.1x10(7) to 1.2x10(9) FFU/g tissue), and kidney(2.5x10(5) to 1.6x10(7) FFU/g tissue), and showed a detectable level of antibodies (titers 1:16-1:32) at 14 dpi. In contrast, the HTN virus infected mice had viruses only in the lungs at low titers (1.1-5.3x10(5) FFU/g tissue). Observations of body-weight changes revealed that the AMR and FE genotype viruses inoculated mice had lower growth rates than the HTN virus inoculated mice. These data suggest that the AMR and FE genotype viruses are more virulent than the HTN virus in newborn mice.     

Molecular cloning, chromosomal location, and biological activity of porcine interleukin-21

A pig interleukin-21 (IL-21) cDNA was successfully cloned and sequenced from porcine peripheral blood lymphocytes (PBL) stimulated with 10 microg/ml concanavalin A (ConA), 10 microg/ml phytohemagglutinin P (PHA), 50 ng/ml phorbol 12-myristate 13-acetate (PMA), and 0.5 microg/ml anti-porcine CD3 antibody for 48 hr. The open reading frame of the porcine IL-21 cDNA is 459 base pairs in length and encodes 152 amino acids. The predicted amino acid sequence of the porcine IL-21 shows 86.2%, 77.7%, and 58.4% identity to the bovine, human, and murine IL-21, respectively. The porcine IL-21 gene was mapped to porcine chromosome 8 (8q22-->q23) by means of fluorescence in situ hybridization and radiation hybrid mapping, where the porcine IL-2 gene had been mapped nearby. The recombinant porcine mature IL-21 expressed by E. coli induced dose-dependent proliferation and IFN-gamma production from a human NK cell line, NK0. The porcine IL-21 identified in this study will be helpful for the enhancement of innate immune responses of pigs.     

Xenografting of bovine secondary follicles into ovariectomized female severe combined immunodeficient mice

Xenografting of ovarian tissue into immunodeficient mice has been used as a model to study the dynamics of follicular development and provides an alternative method for the production of mature oocytes. In a previous experiment, we demonstrated that xenografted bovine secondary follicles developed to the antral stage in severe combined immunodeficient (SCID) mice. In the present study, we examined the development of bovine secondary follicles (140-190 microm in diameter) grafted into ovariectomized mice in comparison with intact female mice as a control. At 4 weeks after grafting, several antral follicles ranging from 350 to 550 microm (457.6 +/- 50.8 microm) in diameter were found in the control mice, while a single large (larger than 2.5 mm) antral follicle and other small follicles were observed in every ovariectomized mouse. At 6 weeks after grafting, the mean diameter of morphologically normal follicles had further increased in the control group (591.8 +/- 132.0 microm). In ovariectomized mice, however, the mean diameter of follicles decreased (4 weeks: 864.2 +/- 988.2 microm; 6 weeks: 496.5 +/- 137.6 microm), since the single large antral follicle observed at 4 weeks had degenerated by 6 weeks. In control mice, more than 70% of follicles were morphologically normal and formed an antrum, and most of the follicles contained morphologically normal oocytes which grew to 122.5 +/- 2.2 microm. In ovariectomized mice, morphologically normal oocytes also grew larger than before grafting, but their survival rate was significantly lower than that in control mice. These results suggest that ovariectomy of host mice alters the developmental pattern of xenografted bovine secondary follicles to accelerate a single follicle to develop in the graft.     

Inhibitory effects of Zingiber officinale Roscoe derived components on aldose reductase activity in vitro and in vivo

Ginger (Zingiber officinale Roscoe) continues to be used as an important cooking spice and herbal medicine around the world. Scientific research has gradually verified the antidiabetic effects of ginger. Especially gingerols, which are the major components of ginger, are known to improve diabetes including the effect of enhancement against insulin-sensitivity. Aldose reductase inhibitors have considerable potential for the treatment of diabetes, without increased risk of hypoglycemia. The assay for aldose reductase inhibitors in ginger led to the isolation of five active compounds including 2-(4-hydroxy-3-methoxyphenyl)ethanol (2) and 2-(4-hydroxy-3-methoxyphenyl)ethanoic acid (3). Compounds 2 and 3 were good inhibitors of recombinant human aldose reductase, with IC50 values of 19.2 +/- 1.9 and 18.5 +/- 1.1 microM, respectively. Furthermore, these compounds significantly suppressed not only sorbitol accumulation in human erythrocytes but also lens galactitol accumulation in 30% of galactose-fed cataract rat model. A structure-activity relationship study revealed that the applicable side alkyl chain length and the presence of a C3 OCH3 group in the aromatic ring are essential features for enzyme recognition and binding. These results suggested that it would contribute to the protection against or improvement of diabetic complications for a dietary supplement of ginger or its extract containing aldose reductase inhibitors.     

Effect of bread baking on the bioavailability of hydrogen-reduced iron powder added to unenriched refined wheat flour

Elemental iron powders are widely used to fortify flour and other cereal products. Our objective was to test the hypothesis that baking enhances the bioavailability of elemental iron powders by oxidizing Fe(0) to Fe(2+) or Fe(3+). An in vitro digestion/Caco-2 cell culture model and a piglet model were used to measure bioavailability. Bread flour, either unfortified or fortified with hydrogen-reduced (HR) iron powder or FeSO(4) (300 mg Fe/kg flour), was baked into bread. For the in vitro studies, bread samples were treated with pepsin at pH 2, 3, 4, 5, 6, or 7 and subsequently incubated with pancreatic enzymes at pH 7 in a chamber positioned above monolayers of cultured Caco-2 cells. Ferritin formation in the cells was used as an index of iron bioavailability. Ferritin formation in cells fed HR Fe bread was similar to cells fed FeSO(4) bread when the peptic digestion was conducted at a pH 2 but lower when the peptic phase was conducted at pH 3, 4, 5, 6, or 7 (P < 0.05). Pig diets containing 35% dried bread were prepared and fed to cross-bred (Hampshire x Landrace x Yorkshire) anemic pigs in two studies. The rate of increase in hemoglobin Fe over the feeding period was used to calculate relative biological value (RBV), an index of iron bioavailability. In the first pig study, RBV of HR Fe added to flour prior to baking was 47.9% when compared to FeSO(4) fortified flour (P < 0.05). In the second pig study, a third treatment consisting of unfortified bread with HR iron added during diet mixing (after bread baking) was included. RBVs of the HR Fe diet (Fe added after baking) and HR Fe diet (Fe added before baking) were 40.1% and 53.5%, respectively, compared to the FeSO(4) diet. Differences in RBV between the HR Fe (before and after baking) and FeSO(4) (before baking) treatment groups were significant, but the difference between the before and after HR treatment groups was not significant. We conclude that bread baking does not enhance the bioavailability of elemental iron powders.     

Changes in allergenicity and digestibility of squid tropomyosin during the Maillard reaction with ribose

The effect of the Maillard reaction on the allergenicity of squid tropomyosin (TM) was investigated. When TM was reacted with ribose (TM-ribose), its human-specific IgE-binding ability decreased markedly and alpha-chymotryptic digestibility of TM was also altered at the early stage of the Maillard reaction. On the other hand, the modification of the lysine residues in TM using 2,4,6-trinitrobenzenesulfonic acid had no effect on the allergenicity and alpha-chymotryptic digestibility of TM. Therefore, the structural change in TM induced by the Maillard reaction would cause the reduction of the allergenicity, rather than the block of lysine residues. Although peptic digestion diminished the specific IgE-binding ability of TM, the reduction of the allergenicity by the Maillard reaction remained after peptic digestion. These results suggest that hypersensitive reaction of TM-ribose in the human body might be lower than that of native TM.     

Bovine hepatocyte growth factor and its receptor c-Met: cDNA cloning and expression analysis in the mammary gland

Hepatocyte growth factor/scatter factor (HGF/SF) is a pleiotropic cytokine that plays a crucial role in the embryonic and postnatal development of various organs including the mammary gland. We cloned bovine HGF and its c-Met receptor cDNAs, and examined their expression during mammary gland development in dairy cows. The 2.5-kbp HGF cDNA clone contained a 2190 bp open reading frame coding a 730 amino acid protein, while the 4.8-kbp c-Met cDNA clone contained a 4152 bp open reading frame coding a 1384 amino acid protein. The bovine HGF and c-Met sequences exhibited more than 87% identity with those of other mammals. RT-PCR analysis revealed ubiquitous expression of both HGF and c-Met mRNAs in various bovine tissues tested. HGF mRNA was detected only in the inactive stage of bovine mammary gland development and not in the developing, lactating, and involuting stages, while c-Met mRNA was detected in the inactive and involuting stages. Immunohistochemical analysis demonstrated that the c-Met protein was found on mammary epithelial cells in the inactive, developing, and involuting stages, and on myoepithelial cells in all stages. These results suggest pivotal roles of HGF and c-Met in the development of bovine mammary gland.     

Polymorphisms in the canine glutamate transporter-1 gene: identification and variation among five dog breeds

Excitatory amino acid transporters (EAATs) are important for terminating glutamatergic neurotransmission and protect central nervous system (CNS) neurons from glutamatergic excitotoxicity. We selected these genes as targets that may relate to canine behavioral traits. After screening four EAAT genes (glutamate transporter-1; GLT-1, excitatory amino acid transporter 4; EAAT4, excitatory amino acid carrier; EAAC1, glutamate/aspartate transporter; GLAST) for single nucleotide polymorphisms (SNPs), we identified two silent SNPs (C129T and T471C) in the GLT-1 gene. We genotyped 193 dogs of 5 breeds and found significant variation among breeds in these two SNPs in GLT-1. The C129T polymorphism was not observed in Malteses and Miniature Schnauzers. These results suggest that polymorphisms in the GLT-1 gene may be useful markers for examining how the genetic background relates to the behavioral traits of dogs.     

A comparison of the behavioral profiles of purebred dogs in Japan to profiles of those in the United States and the United Kingdom

To clarify the behavioral profiles of 56 pure breeds of dogs in Japan, 96 small-animal veterinarians participated in a questionnaire survey using the same criteria as in preceding studies conducted in the United States and the United Kingdom. We found significant differences among breeds in all behavioral traits examined. In addition, gender differences were revealed in terms of aggression to dogs, territorial defense, excitability, general activity, dominance over owner, destructiveness, watchdog barking, and snapping at children, which were all rated higher in males than females, whereas obedience training and housebreaking ease were rated higher in females. No gender differences were evident in playfulness, excessive barking, or affection demand. Using factor analyses, "aggressiveness", "reactivity", and "trainability" were determined to be consistent with results found in the US and UK surveys. On the basis of these factor scores, seven groups of breeds were determined by cluster analysis to compare to the US survey; 22 of the 38 breeds common with the US survey were categorized into the same groups as those in that survey. The results demonstrated differences in canine behavioral predisposition among breeds and between genders. The similarity in the results between our study and previous surveys, which involved distinct geographical locales, suggests that the genetic basis of breed-specific temperamental traits is manifested irrespective of the cultural or regional identities of the owners.