Quantitative structure—activity studies of some octopaminergic agonists against Periplaneta americana

The quantitative relationship between the structure of 2-(arylimino) thiazolidines (AITs), arylethanolamines (AEAs) and 2-(arylalkylamino)-2-thi-azolines (AATs) and their octopamine (OA)-agonist activities against the ventral nerve cord of American cockroach, Periplaneta americana L., was analysed using reported physicochemical parameters and regression analysis. The electronic nature of a substituent was the most important factor for AAT, followed by the hydrophobic effects: the more electron-donating and the more hydrophobic the substituent, the greater the activity. The hydrophobic nature of a substituent in AEA was the most important factor, followed by the steric effects: the more hydrophobic the substituent, the greater the activity. The more electron-donating the substituent of AIT, the greater the activity.     

The first report of the ante-mortem diagnosis of Ollulanus tricuspis infection in two dogs

Ollulanus tricuspis is a small nematode parasite of the stomach, and its infection has been reported worldwide in cats but only one report in dogs as post-mortem diagnosis. Two dogs, kept in the Tokyo area, were presented for chronic vomiting. Chronic gastritis was diagnosed histologically, and many nematodes were detected in endoscopically-biopsied gastric samples and in the mucus of vomitus in both dogs. The parasites were small (<1 mm), and their morphological characteristics were consistent with those previously reported for O. tricuspis. The symptoms in one dog completely disappeared after anthelmintic therapy. To our knowledge, this is the first report describing ante-mortem diagnosis of spontaneous gastric O. tricuspis infection in dogs in which infectivity and pathogenicity of the nematode are suggested.     

Use of quantitative real-time RT-PCR to investigate the correlation between viremia and viral shedding of canine distemper virus,and infection outcomes in experimentally infected dogs

We used real-time RT-PCR and virus titration to examine canine distemper virus (CDV) kinetics in peripheral blood and rectal and nasal secretions from 12 experimentally infected dogs. Real-time RT-PCR proved extremely sensitive, and the correlation between the two methods for rectal and nasal (r=0.78, 0.80) samples on the peak day of viral RNA was good. Although the dogs showed diverse symptoms, viral RNA kinetics were similar; the peak of viral RNA in the symptomatic dogs was consistent with the onset of symptoms. These results indicate that real-time RT-PCR is sufficiently sensitive to monitor CDV replication in experimentally infected dogs regardless of the degree of clinical manifestation and suggest that the peak of viral RNA reflects active CDV replication.     

Identification and expression of a gene encoding an epitope that induces hemagglutination inhibition antibody to Avibacterium paragallinarum serovar A

The aims of this study were the identification, cloning, and expression of a genetic region encoding an epitope that induces hemagglutination inhibition (HI) antibody against Avibacterium paragallinarum serovar A and an evaluation of the recombinant protein for immunogenicity in chickens. Although two monoclonal antibodies (MAbs) with HI activity, designated S24-951 and S7-1716-5C, were generated in this study, no reactive proteins with both MAbs were identified by Western blot analysis. A gene fragment of 5157 bp, designated hpa5. 1, was cloned from genomic DNA, and a recombinant protein expressed by hpa5.1, designated HPA5.1, reacted with both MAbs on dot-blot analysis. HPA5.1 showed no hemagglutinating activity, but significantly absorbed HI antibodies in the chicken immune serum. Analysis using a series of deletion mutants prepared from hpa5.1 indicated that a 4.8 kbp gene in hpa5.1 is essential for the expression epitope recognized by MAb S24-951. In addition, chickens immunized once with HPA5.1 showed a high protection rate with sufficient HI antibody titers against challenge exposure with a virulent strain of A. paragallinarum serovar A strain 221. These results show that hpa5. I1 is responsible for the expression of an epitope that induces HI antibody, and HPA5.1 might be a candidate for the development of a new vaccine against avian infectious coryza caused by A. paragallinarum serovar A.     

Serum amyloid A and haptoglobin levels in bovine amyloidosis

Serum amyloid A (SAA) and haptoglobin (Hp) levels were determined in 25 cows suffering from amyloidosis. SAA levels in cows with amyloidosis ranged between < 0.3 and 225.8 microg/ml, with a median level of 105.1 microg/ml, and Hp levels ranged between < 20 and 1860 microg/ml, with a median level of 950 microg/ml. These levels were significantly higher than the levels observed in healthy cows (SAA levels ranged from < 0.3 to 13.5 microg/ml, with median of 1.4 microg/ml, and Hp levels were undetectable in all cases), but were not significantly different from the levels observed in control cows with chronic inflammation. There was a significant correlation between SAA and Hp levels in cows with chronic inflammation , but not in cows with amyloidosis. It was concluded that the serum SAA levels in cows with amyloidosis might be changed by some factor other than inflammation.     

Shiga toxin 2eB-transgenic lettuce vaccine: N-glycosylation is important for protecting against porcine edema disease

Porcine edema disease (ED) is a life-threatening toxemia caused by enteric infection with Shiga toxin 2e (Stx2e)-producing Escherichia coli (STEC) in weaned piglets. We previously reported that the stx2eB-transgenic lettuce 2BH strain shows potential for use as an oral vaccine candidate against ED. However, the 2BH strain expressed a hemagglutinin (HA)-tag together with Stx2eB and contained non-canonical N-glycosylation. Therefore, we developed two Stx2eB-lettuce strains, the 3 (G+) strain in which the HA-tag was removed from 2BH, and the 3 (G-) lettuce strain, in which the 73rd Asn was replaced with Ser to prevent non-canonical N-glycosylation of Stx2eB from the 3 (G+) strain. We examined the protective effect of these newly developed two strains compared with the previous 2BH strain against ED using a colostrum-deprived piglet STEC infection model. We found that the N-glycosylated 2BH and 3 (G+) strains relieved the pathogenic symptoms of ED in STEC-challenged piglets, whereas the non-glycosylated 3 (G-) strain did not. N-Glycosylation of the Stx2eB product in lettuce may be involved in the immune response in piglets.     

Modelling agricultural expansion in Kenya’s Eastern Arc Mountains biodiversity hotspot

The Taita Hills are the northernmost part of the Eastern Arc Mountains of Kenya and Tanzania, which is one of the most important regions for biological conservation in the world. The indigenous cloud forests in this area have suffered substantial degradation for several centuries due to agricultural expansion. In the Taita Hills, currently only 1% of the original forested area remains preserved. In order to create effective policies to preserve the natural resources and biodiversity of the Eastern Arc Mountains it is crucial to understand the causes and interactions involved in the landscape changes in the most degraded areas. The research presented here aimed to understand the role of landscape attributes and infrastructure components as driving forces of agricultural expansion in the Taita Hills. Geospatial technology tools and a landscape dynamic simulation model were integrated to identify and evaluate the driving forces of agricultural expansion and simulate future landscape scenarios. The results indicate that, if current trends persist, agricultural areas will occupy roughly 60% of the study area by 2030. Agricultural expansion will likely take place predominantly in lowlands and foothills throughout the next 20 years, increasing the spatial dependence on distance to rivers and other water bodies. The main factors driving the spatial distribution of new croplands were the distance to markets, proximity to already established agricultural areas and distance to roads. Other driving forces of the agricultural expansion, as well as their implications for natural resources conservation, are discussed. Further studies are necessary to integrate the effects of population pressure and climate change on the sustainability and characteristics of local agricultural systems.     

Responses of a beech (Fagus crenata Blume) stand to late spring frost damage in Morioka,Japan

Following two weeks of a warm period, beech trees at the study site began leafing. However, a spring frost occurred in the cold morning of April 21, 2001 (Day111, Julian day) and killed about 80% of the fresh leaves on a 40-year-old Siebold's beech (Fagus crenata Blume) stand in Morioka, Japan. Leaves emerged on sprouts from latent buds (latent leaves) 36 days after the frost. Field measurements between 1999 and 2003 revealed the following: (1) Leaf area index was about 4 in normal years and about 1.2 in 2001. (2) The elongation of latent leaves took 55 days about 40 days longer, and they matured about 30 days faster than normal leaves in regular years. (3) Photosynthetic capacities were similar between the latent leaves in 2001 and the normal leaves in 2002 at the top of the canopy. A longer leafing period, faster maturation and sustained photosynthetic capacity of the latent leaves would be helpful to reduce the impacts of frost damage on growth. (4) The frost damage greatly reduced NPP from about 2100 DW g m⁻² y⁻¹ in the previous two years to about 1000 DW g m⁻² y⁻¹ in 2001. However, NPP recovered almost completely (about 1800 DW g m⁻² y⁻¹) in 2002. (5) Seasonal NPP increased similarly in 2001 with other years before Day150 for 40 days after the frost, and decreased afterwards. Shoot elongation also stopped at approximately Day150 in normal years. These findings suggested that radial and height growth in the early growing season was supported by the storage of previous year photosynthesis. (6) A regression growth model was created using meteorological data from 1999 and 2000, and the model was applied to data from 2001 to estimate the potential growth under normal conditions. The ratio of measured and estimated NPP changed seasonally, greater than 0.4 between Day150 and Day210, but below 0.25 between Day210 and Day250. This suggests that beech allocated more photosynthetic products for the next year's growth rather than the current growth in the latter growing season, thereby achieving the same initial growth with other years and amazing recovery in 2002.