Roles of the hypocretin/orexins in the regulation of sleep and wakefulness

Hypocretin/orexin is produced exclusively in the dorsal and lateral hypothalamus but its projection is widespread within the brain and plays important roles. In this paper, we review the independent discoveries of the hypocretin/orexin peptides, the neuroanatomy of this system, and the link to the sleep disorder narcolepsy that has led to the idea that this system plays a crucial role in the regulation of sleep and wakefulness.     

Characteristic of Inflammatory Airway Disease in Japanese Thoroughbred Racehorses

Inflammatory airway disease (IAD) is a common cause of poor performance, interruption of training and premature retirement in racehorses. It is also reported that up to 80% of horses are affected at some point in the first years of training in UK and Australia. However, no studies with regard to the information on occurrence of IAD in Japanese Thoroughbred racehorses have been reported. To investigate the occurrence and the characteristics of IAD, epidemic research including endoscopic examination of the airway tract and trachea wash was conducted for Thoroughbred racehorses presenting coughs or poor performance which airway tract disease was suspected stalled in training facility managed by Japan Racing Association. Fifty-six out of 76 Thoroughbred racehorses (73.7%) presenting coughing or poor performance were diagnosed as IAD. Mean incidence rate of IAD was 0.3% and it has been confirmed that constant number of IAD exists in Japan. Up to 35.7% of IAD horses showed upper airway abnormalities in some extent. There was a trend for IAD horses to use wood shavings for bedding and fed hay from the ground compared with the control group. Therefore, improvement of stabling environment may aid in preventing IAD. This study demonstrated that Japanese Thoroughbred racehorses are affected by IAD likewise other countries as well as demonstrated the characteristics of IAD which may contribute to the clarification of the pathogenesis of IAD.     

Effect of feeding wood kraft pulp on the growth performance,feed digestibility,blood components,and rumen fermentation in Japanese Black fattening steers

This study aimed to examine the effects of feeding kraft pulp (KP) on the growth performance, feed digestibility, and rumen fermentation of Japanese Black fattening steers. Ten Japanese Black fattening steers (aged 26 months) were randomly divided into control and KP groups. The control group (n = 5) was fed concentrate feed without KP, and the KP group (n = 5) was fed concentrate feed containing 10% KP. Both the groups were provided rice straw as roughage. The experiment was conducted over a period of 12 weeks. There was no significant difference in dry matter intake, daily body weight gain, and nutrient digestibility between both groups. No difference was observed in the ruminal concentrations of volatile fatty acids among the groups. At weeks 8 and 12 after the onset of the experiment, the acetate‐to‐propionate ratio in the ruminal fluid of the KP group was significantly higher than that of the control group. The average daily pH of ruminal fluid and activity of ruminal lipopolysaccharide did not differ between the groups. Our results suggested that the growth performance and feed digestibility in the Japanese Black fattening steers were not influenced by replacing concentrate feed with KP.     

Gastrointestinal motility modulation by stress is associated with reduced smooth muscle contraction through specific transient receptor potential channel

Excessive stress response causes disability in social life. There are many diseases caused by stress, such as gastrointestinal motility disorders, depression, eating disorders, and cardiovascular diseases. Transient receptor potential (TRP) channels underlie non-selective cation currents and are downstream effectors of G protein-coupled receptors. Ca²⁺ influx is important for smooth muscle contraction, which is responsible for gastrointestinal motility. Little is known about the possible involvement of TRP channels in the gastrointestinal motility disorders due to stress. The purpose of this study was to measure the changes in gastrointestinal motility caused by stress and to elucidate the mechanism of these changes. The stress model used the water immersion restraint stress. Gastrointestinal motility, especially the ileum, was recorded responses to electric field stimulation (EFS) by isometric transducer. EFS-induced contraction was significantly reduced in the ileum of stressed mouse. Even under the conditions treated with atropine, EFS-induced contraction was significantly reduced in the ileum of stressed mouse. In addition, carbachol-induced, neurokinin A-induced, and substance P-induced contractions were all significantly reduced in the ileum of stressed mouse. Furthermore, the expression of TRPC3 was decreased in the ileum of stressed mouse. These results suggest that the gastrointestinal motility disorders due to stress is associated with specific non-selective cation channel.     

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.     

Magnetic resonance imaging of alveolar echinococcosis experimentally induced in the rat lung

Pulmonary alveolar echinococcosis (AE) caused by the metacestode of Echinococcus multilocularis is a lethal zoonosis and is a lesion secondarily induced by hematogenous dissemination from hepatic AE lesions. In the present study, a hematogenous pulmonary AE model was experimentally induced in rats by the injection of echinococcal larval tissue homogenate to the tail vein, and then the pathological and diagnostic aspects of pulmonary AE were examined by magnetic resonance imaging (MRI). Histological primary, mature and degenerated AE lesions were observed 5, 18 and 50 weeks after injection, respectively. These lesions were discriminated as signal-void, hypointense and hyperintense regions in T1-weighted MRI (T1WI), respectively. The change in signal intensity in T1WI might reflect the content of proteinaceous fluid as a result of AE cyst degeneration. Western blot analysis of sera with antibodies of two epitopes (Em18 and Em16) of E. multilocularis provided evidence for AE infection in the early stage. T1WI in combination with Western blot analysis could possibility become definitive and early signs of hematogenous pulmonary AE infection.     

Involvement of a host erythrocyte sialic acid content in Babesia bovis infection

Host sialic acid (SA) has recently been suggested to play an important role in erythrocyte (RBC) infection by Babesia spp. The present study attempted to further determine the specific type of SAs important in the RBC invasion. Bovine RBC was found to bear abundant alpha2-3-linked SA residues but not alpha2-6-linked SA in nature, confirmed by flow cytometric analysis of the neuraminidase (Nm)-treated RBCs. Lectin-blot analyses revealed the removal of alpha2-3-linked SAs from the 97-, 33-, and 31-kDa bands by the Nm treatment. Addition of the Nm-treated RBCs into an in vitro culture of B. bovis resulted in a decreased population of the parasitized RBCs. The thin smear samples from the cultures were then observed under a confocal laser scanning microscope after staining with the alpha2-3-linked SA-specific lectin: a selective invasion of B. bovis was found only in the intact RBCs bearing the SAs, but not in the desialylated RBCs. Furthermore, a significant reduction of the parasitized RBCs was also observed in the culture supplemented with exogenous 3'-sialyllactose containing the alpha2-3-linked SAs. However, the complete inhibition of parasite proliferation was not achieved in the culture. These findings indicate that while the alpha2-3-linked SA-dependent pathway is needed for highly efficient invasion of host RBCs by B. bovis, there might also be other potential alternative pathways.     

Effects of leptin and tumor necrosis factor-alpha on degranulation and superoxide production of polymorphonuclear neutrophils from Holstein cows

Leptin, a pleiotropic hormone regulating food intake and energy expenditure, has been shown to directly modulate human polymorphonuclear neutrophil (PMN) functions or indirectly through the action of tumor necrosis factor-alpha (TNF-alpha). Bovine PMN have considerable different characteristics from human PMN. For example, it does not respond to N-formyl-Methionyl-Leucyl-phenylalanine, a well known human PMN activator. In the present study, we tested the effects of leptin and TNF-alpha on superoxide production and degranulation of bovine peripheral PMN, in which both long isoform of leptin receptor (Ob-Rb) and TNF receptor 1 were expressed. Human leptin, human TNF-alpha, phorbol myristate acetate (PMA) and opsonized zymosan particles (OZP) did not stimulate degranulation responses, while zymosan-activated serum (ZAS) did. Neither leptin nor TNF-alpha enhanced the ZAS-induced degranulation responses. TNF-alpha, PMA, OZP and ZAS increased superoxide production in different magnitudes, whereas leptin did not. TNF-alpha, but not leptin, enhanced OZP- and ZAS-induced superoxide production, possibly, in part due to facilitating translocation of p47(phox), a component of NADPH oxidase. These results indicate that, unlike in human PMN, leptin does not have any direct effect on degranulation and superoxide production in bovine PMN, although TNF-alpha influences superoxide production.     

Cloning of bovine MAIL and its mRNA expression in white blood cells of Holstein cows

Molecule possessing ankyrin-repeats induced by lipopolysaccharide (MAIL) is known as an IkappaB protein induced after administration of bacterial lipopolysaccharide (LPS) to mice. In the present study, we cloned bovine MAIL cDNA and examined its mRNA expression in white blood cells isolated from Holstein cows. Bovine MAIL had more than 80% amino acid identities with murine and human MAILs, highly conserved ankyrin-repeat motifs and PEST-like sequences. Bovine MAIL mRNA was undetectable in isolated peripheral white blood cells, but rapidly induced (<1h) after stimulation by LPS and lipid A in vitro in a dose-dependent manner. The lipid A-induced MAIL mRNA expression was found in polymorphonuclear cells, monocytes/macrophages and total lymphocytes, but not in T-lymphocytes. MAIL mRNA was also induced in vivo in peripheral blood leukocytes of cows after intramammary injection of Escherichia coli derived from coliform mastitis. Thus, bovine MAIL, as rodent MAILs, is induced by inflammatory stimuli in specific immune cells in vitro and in vivo, suggesting a role in inflammatory responses to bacterial infection in cattle.     

Odontoclastic resorptive lesions in a dog

We found odontoclastic resorptive lesions on premolars and molars in a 4- year-old miniature dachshund. The teeth had been extracted because the dentin was resorbed. In some teeth, the roots had been replaced by hard tissue, and so we amputated the crowns and curetted roots and alveolar bone. Histopathological examination revealed that the dentin was resorbed by odontoclasts and was replaced with bony tissue. Ten months later we found resorptive lesions in other teeth, and we treated them along with the first treatment. At the time of writing, since this is the first report of a dog with the same lesion in other teeth after the first treatment, we hope to establish better treatment and prevention methods.