Cardiopathological observation on a case of persistent ventricular tachycardia in a pony mare.

A 20-year-old pony mare with persistent ventricular tachycardia (VT) was examined cardiopathologically. At necropsy, the heart was enlarged and rounded with both ventricular dilatation. In a longitudinal section of the ventricular septum, a large grayish white patchy lesion (5 x 25 mm) was detected in the relatively higher portion. Microscopically, the lesion was extensive myocardial fibrosis located in the vicinity of the proximal part of the left bundle branch. Partially the fibrotic lesion was in contact with the branch. Such a lesion might play an important role in creating a suitable background for the development of VT via automaticity or reentry mechanism.     

Decreased transport of orally administered protein into the blood circulation of developing juveniles of Japanese eel Anguilla japonica

ABSTRACT: To clarify the quantitative changes in the transport of orally intubated protein into the blood circulation as macromolecules in development, immunoglobulin Y (IgY) extracted from chicken eggs was administered orally to juvenile Japanese eel, Anguilla japonica . For the first experiment, which was performed before the commencement of artificial feeding, the oral delivery of 2.0 μg/0.1 g bodyweight of IgY resulted in a rapid increase in plasma IgY to a maximum of 2.30 μg/mL. However, the transport of IgY into the blood decreased significantly in the experiments that followed, which were performed after 12, 25 and 42 days. During this period, bodyweight increased approximately by a factor of eight, and rapid growth of the stomach was observed histologically. Possible contributions for the development of the alimentary canal to the diminishment of intestinal protein assimilation are discussed.     

Increased expression of fractalkine and its receptor CX(3)CR1 in canine inflammatory bowel disease and their possible role in recruitment of intraepithelial lymphocytes

The interaction between fractalkine/CX(3)CL1 and its receptor CX(3)CR1 has been reported to play an important role in various human inflammatory diseases, including inflammatory bowel disease (IBD) mediated by lymphocyte chemoattraction. The objective of this study was to investigate the role of fractalkine and CX(3)CR1 in lymphocyte migration in canine IBD. IBD was diagnosed in 34 dogs, and 19 healthy beagles were used as normal controls. We quantified intestinal mRNA and protein expression of fractalkine and CX(3)CR1 by real-time RT-PCR and ELISA, respectively, and examined the localization of fractalkine in canine intestine by immunohistochemistry. The expression of CX(3)CR1 and surface antigens on peripheral blood mononuclear cells (PBMCs) and intraepithelial lymphocytes (IELs) was analyzed by flow cytometry. Intestinal fractalkine and CX(3)CR1 mRNA was significantly up-regulated in IBD dogs compared with the healthy control dogs. In addition, fractalkine expression on intestinal epithelial cells was significantly increased in the intestinal mucosa of IBD dogs compared with the healthy dogs. CX(3)CR1(+) PBMCs were significantly elevated in IBD dogs and positively correlated with the histopathological severity of IELs infiltration. These CX(3)CR1(+) PBMCs predominantly expressed markers for cytotoxic T cells. Almost all IELs expressed CD3, and the majority of cells expressed CD8 rather than CD4, which was analogous to the CX(3)CR1(+) PBMCs. These results suggest that the fractalkine-CX(3)CR1 interaction may contribute to the pathogenesis of canine IBD through migration of IELs.     

A case of canine multiple inflammatory colorectal polyps treated by endoscopic polypectomy and argon plasma coagulation

Endoscopic polypectomy and argon plasma coagulation (APC) were performed in a refractory case of inflammatory colorectal polyps in a 7-year-old male Miniature Dachshund. Colonoscopic examination revealed a large sessile polyp and multiple diffuse small polyps, localized to the descending colon and rectum. The case showed a poor therapeutic response to prednisolone and cyclosporine. Under anesthesia, piecemeal resections were performed by polypectomy. APC was carried out to cauterize the polyp remnants. After treatment, reduction of the lesions and the improvement in clinical signs were observed, without recurrence of lesions for at least 10 months. Endoscopic treatment by polypectomy and APC is suggested to be a therapeutic option for refractory cases of inflammatory colorectal polyps in dogs.     

The significance of meandering channel morphology on the diversity and abundance of macroinvertebrates in a lowland river in Japan

• 1. Many rivers and streams across the world have been channelized for various purposes. Channel cross‐sections of meandering rivers are asymmetrical and have cross‐sectional diversity in their physical environment; cross‐sections of a channelized river are typically trapezoidal and have little cross‐sectional diversity, both in physical and ecological conditions. Several programmes to restore stream meanders have been undertaken to improve river ecosystems degraded by channelization. However, the association between diversification in the physical environment due to meander restoration and the macroinvertebrate community structure is poorly known.
• 2. This study of a lowland river in Japan assessed how the cross‐sectional diversity of the physical environment changed with restoration of a meander in a channelized river, and how the macroinvertebrate communities responded to the changes in physical habitat variation. Comparisons were made between the macroinvertebrate communities of a channelized reach, the restored meandering reach, and a natural meandering reach.
• 3. Natural meandering and restored meandering reaches showed higher cross‐sectional diversity in physical variables and total taxon richness across a reach than did the channelized reach. Almost all taxa observed in the natural and restored meandering reaches were concentrated in the shallowest marginal habitats near the banks. Shear velocity increasing with water depth had a negative association with macroinvertebrate density and richness.
• 4. This study demonstrated that the shallow river bed along the inside of bends formed point bars that provided a highly stable substrate, a suitable habitat for macroinvertebrates in a lowland river. It is concluded that meander restoration could be an effective strategy for in‐stream habitat restoration in lowland meandering rivers.

Copyright © 2007 John Wiley & Sons, Ltd.     

Performance of Bangladesh indigenous rice in a weed infested field and separation of allelopathy from resource competition

This study aimed to identify the potential allelopathic indigenous rice (Oryza sativa L. ssp. indica) varieties from Bangladesh using a performance study in a weed‐infested field and to assess the extent of allelopathic interference relative to resource competition in a glasshouse experiment. Six varieties – namely, “Boterswar,” “Goria,” “Biron” and “Kartiksail” as the most allelopathic, “Hashikolmi” as weakly allelopathic and “Holoi” as nonallelopathic – were raised following a nonweed control method. The infestation levels of weed species were calculated using Simpson's Diversity Index (SDI), which ranged from 0.2 to 0.56. However, a significant correlation coefficient (0.87, P < 0.001) was obtained from these field data compared with the root inhibition percentage from the laboratory bioassay, and the “Boterswar” variety was the most allelopathic. The interactions between the allelopathic variety “Boterswar,” weakly allelopathic variety “Hashikolmi” and Echinochloa oryzicola via a target (rice)‐adjacent (E. oryzicola) cogrowth culture were determined in a hydroponic arrangement. The relative competitive intensity (RCI) and the relative neighbor effect (RNE) values showed that the crop–weed interaction was facilitation for “Boterswar” and competition for “Hashikolmi” and E. oryzicola in rice/E. oryzicola cogrowth cultures. The allelopathic effects of “Boterswar” were much higher than the resource competition in rice/E. oryzicola cogrowth cultures. The converse was observed for “Hashikolmi.” Moreover, the mineral content of E. oryzicola was severely affected by “Boterswar”/E. oryzicola cogrowth cultures’ exudate solution. Therefore, the allelopathic potential of “Boterswar” variety might be useful for developing the weed‐suppressing capacity of rice, which will likely have a significant influence on paddy weed control.     

Study of the Structure–Activity Relationship of an Anti-Dormant Mycobacterial Substance 3-(Phenethylamino)Demethyl(oxy)aaptamine to Create a Probe Molecule for Detecting Its Target Protein

The current tuberculosis treatment regimen is long and complex, and its failure leads to relapse and emergence of drug resistance. One of the major reasons underlying the extended chemotherapeutic regimen is the ability of Mycobacterium tuberculosis to attain a dormant state. Therefore, the identification of new lead compounds with chemical structures different from those of conventional anti-tuberculosis drugs is essential. The compound 3-(phenethylamino)demethyl(oxy)aaptamine (PDOA, 1), isolated from marine sponge of Aaptos sp., is known as an anti-dormant mycobacterial substance, and has been reported to be effective against the drug resistant strains of M. tuberculosis. However, its target protein still remains unclear. This study aims to clarify the structure–activity relationship of 1 using 15 synthetic analogues, in order to prepare a probe molecule for detecting the target protein of 1. We succeeded in creating the compound 15 with a photoaffinity group that retained antimicrobial activity, which proved to be a suitable probe molecule for identifying the target protein of 1.     

Effective Synthesis and Antifouling Activity of Dolastatin 16 Derivatives

Some derivatives of dolastatin 16, a depsipeptide natural product first obtained from the sea hare Dolabella auricularia, were synthesized through second-generation synthesis of two unusual amino acids, dolaphenvaline and dolamethylleuine. The second-generation synthesis enabled derivatizations such as functionalization of the aromatic ring in dolaphenvaline. The derivatives of fragments and whole structures were evaluated for antifouling activity against the cypris larvae of Amphibalanus amphitrite. Small fragments inhibited the settlement of the cypris larvae at potent to moderate concentrations (EC₅₀ = 0.60-4.62 μg/mL), although dolastatin 16 with a substituent on the aromatic ring (24) was much less potent than dolastatin 16.     

Characterisation of cross-reactivity of virus neutralising antibodies induced by feline panleukopenia virus and canine parvoviruses

It was recently reported that canine parvoviruses (CPV) had entered cat populations and induced disease in infected cats, while they had affected only dogs in the past. It is important to determine whether conventional feline panleukopenia virus (FPLV) vaccines protect against recent CPV infections. In this study, the cross-reactivity of virus-neutralising (VN) and haemagglutinin-inhibition (HI) antibodies in cats induced by FPLV and CPV s were examined. Lower cross-reactivities of VN and HI antibodies against each CPV strain were observed in cats experimentally inoculated with FPLV or vaccinated with an inactivated FPLV vaccine. In addition, we revealed the existence of a novel type of FPLV, which reacted weakly with antibodies induced by the conventional FPLV vaccine.     

Effect of ovarian hormones on maturation of dendritic cells from peripheral blood monocytes in dogs

Previously, we reported that ovarian hormones affect the immune response against E. coli isolated from the dogs affected with pyometra. In order to investigate mechanisms underlying the immune modulation, we examined the effects of ovarian hormones on the generation of dendritic cells (DCs), the most potent antigen presenting cell. DCs were differentiated from peripheral blood monocytes (PBMOs) using a cytokine cocktail. Both estrogen receptor and progesterone receptors were expressed by the PBMOs and immature DCs. When various ovarian hormones were added to the culture for the DC differentiation, progesterone significantly decreased the expression of DC maturation markers, such as CD1a, CD80 and CD86, on mature DCs. Conversely, the addition of estrogen to the cultures increased the expression of CD86, but not other maturation makers. Furthermore, DCs differentiated in the presence of progesterone did not stimulate allogeneic mononuclear cells in PB. Taken together, these results indicate that progesterone diminishes the maturation of DCs, leading to decreased immune responses against invading pathogens.