Distribution of the pores of epithelial basement membrane in the rat small intestine

The distribution and diameter of the pores of epithelial basement membrane in the intestinal villi and the lymph nodules of ileal Peyer's patches were investigated in the rat small intestine by scanning electron microscopy after the removal of the overlying epithelial cells with OsO(4) maceration. In the duodenum, jejunum and ileum, the pores were mainly distributed at the upper three fourths of the villi, but were scarce around the top of the villi. The diameter of some of the pores in the upper three fourths of the villi was larger than that of those in the lower portion. The protrusion of lymphocytes and the cytoplasmic processes of macrophages were also seen at the orifices of the pores. In ileal Peyer's patches, in contrast, pores were densely distributed in the lower one third of the follicle-associated epithelium (FAE) where M cells were mainly seen. Furthermore, these pores were larger than those found in the upper two thirds. Lymphocytes or cytoplasmic processes of macrophages were frequently seen in the lower one third of FAE. These results suggest that the pores at the basement membrane correspond to the passage of the immunocompetent cells which are in contact with M cells or villous columnar epithelial cells and that the abundance of pores is a sign of aggressive interaction between the particular epithelial cells and the immunocompetent cells at the upper three fourths of intestinal villi and the lower one third of FAE in the rat small intestine.     

Importance of shingle beaches as habitat for Manila clam Ruditapes philippinarum

Fisheries Science - We carried out surveys to clarify how the density (no. of individuals/m2) and condition factor (CF) of Manila clam Ruditapes philippinarum differ between estuarine tidal flats...     

Inhibitory effects of seaweeds on histamine release from rat basophile leukemia cells (RBL-2H3)

ABSTRACT:   The effects of 80% methanol extracts from frozen samples of 41 macroalgae and one sea grass collected in the Ise-Shima region of Japan were investigated on histamine release from rat basophile leukemia cells (RBL-2H3) sensitized with antidinitrophenyl (DNP) IgE and stimulated with DNP-BSA. Of the 21 brown algae, five green and 15 red algae, and one sea grass tested, only extracts from seven brown algae suppressed histamine release from RBL cells, as determined by high-performance liquid chromatography (HPLC) analysis. When the cytotoxic effects of the seven brown algal extracts were investigated by Trypan blue staining, only Eisenia arborea and Sargassum thunbergii did not show cytotoxic effects. Therefore, we conclude that E. arborea and S. thunbergii may contain compounds that have antiallergic effects without inducing cell death.     

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.     

Hypereosinophilic syndrome in two cats

Two cats showing chronic vomiting, diarrhea and weight loss were found to have leukocytosis with marked eosinophilia. Both cats were diagnosed with hypereosinophilic syndrome by the findings of increased eosinophils and their precursors in the bone marrow, eosinophilic infiltration into multiple organs, and exclusion of other causes for eosinophilia. Although cytoreductive chemotherapy with hydroxycarbamide and prednisolone was performed, these two cats died 48 days and 91 days after the initial presentation.     

Biological and phylogenetic characterization of Fusarium oxysporum complex, which causes yellows on Brassica spp., and proposal of F. oxysporum f. sp. rapae, a novel forma specialis pathogenic on B. rapa in Japan

Although the causal agent of yellows of Brassica rapa (turnip, pak choi, and narinosa) in Japan was reported in 1996 to be Fusarium oxysporum f. sp. conglutinans, this classification has remained inconclusive because of a lack of detailed genetic and pathogenic studies. Therefore, we analyzed the taxonomic position of this organism using Japanese isolates of F. oxysporum complex obtained from diseased individuals of various B. rapa subspecies. Phylogenetic analyses using partial sequences of the rDNA intergenic spacer region and the mating-type gene (MAT1-1-1alpha-box) showed that B. rapa and cabbage isolates belong to different monophyletic clades that separated at early evolutionary stages. Additionally, correlations were observed between the molecular phylogeny and the vegetative compatibility groups. Isolates from turnip, komatsuna, and narinosa (B. rapa group) did not show pathogenicity against cabbage or broccoli (B. oleracea group), although they caused severe symptoms on their original host species. In contrast, cabbage isolates had significantly higher (P = 0.05) virulence on B. oleracea than on B. rapa crops. Our results indicate that F. oxysporum complex isolates from B. rapa and B. oleracea are not only phylogenetically distinct but also differ in host specificity. Therefore, we propose a novel forma specialis, F. oxysporum f. sp. rapae, which causes yellows on B. rapa, including turnip, komatsuna, pak choi, and narinosa.     

Anatomical characterization of decayed wood in standing light red meranti and identification of the fungi isolated from the decayed area

To further our understanding of wood decay in living light red meranti (Shorea smithiana) trees, microscopic characteristics of the cell and cell wall degradations of S. smithiana wood in the presence of the decay fungi, the identity of the causal fungi, and the decay potential and pattern by an isolated fungus were investigated. Cell wall degradations, including cell wall thinning, bore holes formation, rounded pit erosion, and eroded channel opening were clearly observed under light and scanning electron microscopy. In transverse view, many large voids resulting from a coalition of degraded wood tissue appeared in the decayed canker zone. All these observations suggest the well-known simultaneous decay pattern caused by white-rot fungi. By phylogenetic analysis based on the sequences of internal transcribed spacer region of ribosomal DNA, a basidiomycete fungus isolated from the decayed wood was identified as Schizophyllum commune. The degradation caused by this fungus on sound S. smithiana wood in an in situ laboratory decay test was classified as the early stage of simultaneous decay, and showed a similar pattern to that observed in the wood samples naturally decayed.     

Understanding patterns of tree adoption on farms in semi-arid and sub-humid Ethiopia

Trees on farms are a widespread feature of landscapes across a large part of Ethiopia with an important role in enhancing the resilience of smallholder livelihoods through the provision of ecosystem services. Despite their importance, little is known about what trees are planted or retained from natural regeneration by different types of farmers that results in the pattern of tree cover found in the region. We address this knowledge gap through analysis of household survey data from semi-arid and sub humid areas of Oromia regional state. A set of composite variables that represent distinctive patterns of tree cover on farms were derived from principal component analysis and Pearson correlation analysis. This revealed two major tree adoption strategies: farmer managed natural regeneration (FMNR) of trees to meet subsistence needs as well as contributing to other ecosystem services; and, high value agroforestry (HVAF) involving planted trees used largely to produce fruits, timber and fodder. Regression analysis further identified fine-scale variation in ecological and socio-economic factors that affect which of these two broad strategies are adopted by farmers. Favorable climatic conditions coupled with institutional arrangements to control free grazing were pre-conditions for HVAF, whereas poor biophysical potential and sloping land provided a positive incentive for farmers to adopt FMNR. Farmers with preferences for tree species with multiple utilities and locational flexibility favored FMNR while adoption of HVAF was more asset-driven. Our findings reveal that farmers integrate many native and exotic tree species on their farms to meet their variable farm conditions, needs and asset profiles in stark contrast to most tree promotion efforts that focus on a few, usually exotic, tree species. We recommend that future agroforestry promotion should embrace a diversity of tree species appropriate to matching the fine scale variation in ecological conditions and farmer circumstances encountered in the field.     

Productivity of Jatropha curcas under smallholder farm conditions in Kenya

With the global bioenergy boom, the planting of jatropha (Jatropha curcas) was widely promoted by the private sector and non-government organizations as one of the candidate tree species for bioenergy in Kenya. This was motivated by the belief that it grows easily with minimal management requirements. The present study attempts to determine whether management practices by smallholder farmers, which are heterogeneous, are optimal for jatropha yields in Kenya. A survey conducted in different agro-ecological zones showed that yields are very low under Kenyan farm conditions. Regardless of the age and management condition, 41 % of the farmers obtained no seed yield, while 79 % obtained up to 0.1 kg/tree. This is dismal in comparison with the figures (up to 2.0 kg/tree) reported from elsewhere for 1–5 year old trees grown under similar conditions. Examination of farmer management practices indicated that irrigation, manuring and weeding, in order to maximize yields, could be offset by misapplication of other components especially, selection of planting materials, timing of planting and choice of intercrops during the establishment phases. This indicates that the anticipated high yields have not been achieved partly because growers are still using unimproved germplasm, management practices are sub-optimal, and the biophysical boundaries of high jatropha yield are poorly defined. Thus at the current stage, jatropha should not be grown by smallholder farmers in Kenya because of low or dismal productivity. If jatropha is to play a role in the pro-poor bioenergy development, future projects need to identify management recommendations that optimize yields. This also needs to take into consideration the preferences and constraints of farm households on labor and land allocation to other farm and livelihood activities.