Differences in lectin-binding properties between the common mucosal epithelium and follicle-associated epithelium in the rabbit small intestine

Differences in sugar distribution between the villous epithelium and follicle-associated epithelium (FAE) were compared using lectins in the rabbit small intestine. In every portion, villous columnar epithelial cells primarily exhibited a positive reaction to the GalNAc, GlcNAc, galactose, and oligosaccharide. In the ileal Peyer's patch (PP), whereas microvillous epithelial cells exhibited positive reactions, M cells tended to be negative. The villous epithelial reaction to the fucose group was negative, but M cells and microvillous epithelial cells showed a positive to the fucose. No epithelium had a positive reaction to the mannose and glucose. The variety of lectin-binding properties of villous epithelial cells and M cells may reflect specificity for the recognizing luminal substances such as antigenic molecules and bacterial elements.     

Interannual variability in stock abundance of the neon flying squid, Ommastrephes bartramii, in the North Pacific Ocean during 1979–1998: impact of driftnet fishing and oceanographic conditions

Variability in catch-per-unit-effort (CPUE) was examined for the autumn cohort of Ommastrephes bartramii collected with research driftnets during 1979–1998 along five longitudinal transects passing through the Subarctic, Transitional and Subtropical Domains in the North Pacific. CPUE was generally low during the period of intensive commercial driftnet fishing (1980–1992) and increased following the 1992 moratorium on the use of large-scale driftnets. However, CPUE levels were low for the cohorts hatched in 1992 and 1996 (captured in subsequent years owing to a one-year life of O. bartramii ) that experienced low sea surface temperatures from hatching to recruitment. Among similar-aged squid collected from 180° and 179°30'W in June, mantle lengths were significantly greater in 1997 than during 1995–96. These findings suggest that the driftnet fishery and sea surface temperatures from hatching to recruitment strongly affected stock abundance and possibly growth.     

Interdigital involvement in a case of primary cutaneous canine histoplasmosis in Japan

A 5-year-old male Siberian husky bred outdoor in Tokyo had a swollen paw with interdigital granulomatous lesions in the left hindlimb. The dog had no apparent pulmonary or gastrointestinal involvement. Histopathological analysis of the skin lesions demonstrated yeast-like organisms predominantly within macrophages. Sequence analysis of fungal ribosome RNA gene isolated from a paraffin sample revealed a 100% homology with the teleomorph of Histoplasma capsulatum. The present case may support the concept of primary cutaneous canine histoplasmosis as an endemic phenotype recognized in Japan.     

Alleviation of manganese toxicity and manganese-induced iron deficiency in barley by additional potassium supply in nutrient solution

Barley plants were grown hydroponically at two levels of K (3.0 and 30 mm) and Fe (1.0 and 10 μm) in the presence of excess Mn (25 μm) for 14 d in a phytotron. Plants grown under adequate K level (3.0 mm) were characterized by brown spots on old leaves, desiccation of old leaves, interveinal chlorosis on young leaves, browning of roots, and release of phytosiderophores (PS) from roots. These symptoms were more pronounced in the plants grown under suboptimal Fe level (1.0 p,M) than in the plants grown under adequate Fe level (10 μm). Plants grown in 10 μm Fe with additional K (30 mm) produced a larger amount of dry matter and released less PS than the plants grown under adequate K level (3.0 mm), and did not show leaf injury symptoms and root browning. On the other hand, the additional K supply in the presence of 1.0 μM Fe decreased the severity of brown spots, prevented leaf desiccation, and increased the leaf chlorophyll content, which was not sufficient for the regreening of chlorotic leaves. These results suggested that the additional K alleviated the symptoms of Mn toxicity depending on the Fe concentration in the nutrient solution. The concentration (per g dry matter) and accumulation (per plant) of Mn in shoots and roots of plants grown in 10 μm Fe and 30 mm K were much lower than those of the plants grown in 10 μm Fe and 3.0 mm K, indicating that additional K repressed the absorption of Mn. The concentration and accumulation of Fe in the shoots and roots of the plants grown in 10 μm Fe and 30 mm K were higher than those of the plants grown in 10 μm Fe and 3.0 mm K, indicating that the additional K increased the absorption of Fe under excess Mn level in the nutrient solution. The release of PS, chlorophyll content, and shoot Fe concentration were closely correlated.     

Diurnal variations in absorption and translocation of a ferrated phytosiderophore in barley as affected by iron deficiency

The release of phytosiderophore (PS) from roots of Fe-deficient graminaceous plants follows a distinct diurnal rhythm with maximum release rates occurring usually 3 to 4 hours after the onset of light. However, it remains to be determined whether absorption of the PS-Fe³⁺ complex shows a diurnal rhythmicity similar to that of PS release, Barley plants grown with or without 10 µM FeEDTA for 7 days were fed with ferreted PS (10 µM labelled with ⁵⁹Fe) at 4-h intervals to study the diurnal variations in the absorption and transloca tion of ⁵⁹Fe, The absorption of ⁵⁹Fe, irrespective of the Fe nutritional status of the plants, was higher during the day and lower during the night but did not show any peak throughout the day-night cycle. On the other hand, the translocation of ⁵⁹Fe into shoots of Fe-deficient plants was lower than that of Fe-sufficient plants, while the Fe nutritional status of the plants did not affect the absorption of ⁵⁹Fe by roots, The formation of root apoplastic ⁵⁹Fe was lower during the day and higher during the night, regardless of the Fe nutritional status of plants. Our results showed that the absorption of the PS-Fe³⁺ complex by roots did not follow the PS release pattern.     

Effectiveness of Phytosiderophore in Absorption and Translocation of 59Iron in Barley in the Presence of Plant-Borne,Synthetic, and Microbial Chelators

The mechanisms of iron (Fe) absorption and translocation in plants have received much study because they are the key processes in the supply of Fe to plants. The objective of this research was to study the effectiveness of phytosiderophore (PS) in the absorption and translocation of ⁵⁹Fe in Fe-deficient barley (Hordeum vulgare L. cv. ‘Minorimugi’) plants in the presence of plant-borne, synthetic, or microbial chelators. Plants grown under Fe-deficient conditions in a phytotron at pH 5.5 for 7–18 d were fed with Fe³⁺ (10 μ M labeled with ⁵⁹Fe) in the presence of 10 μ M of different chelators with or without 10 μ M PS for 4 h starting at 2 p.m. (6 h after the onset of light period). The absorption and translocation of ⁵⁹Fe in plants treated with PS and Fe^{3 +} were increased relative to plants fed solely with Fe^{3 +} (control). There was no effect found on absorption and translocation of ⁵⁹Fe in plants treated with EDTA or p-coumarate relative to the control, but a differential increase was observed in ⁵⁹Fe absorption and translocation in plants treated with EDTA or p-coumarate in the presence of PS. In comparison with the control, a decrease in ⁵⁹Fe absorption and translocation was observed in plants treated with HEDTA or EDDHA or FOB, but this decrease was avoided in plants treated with HEDTA or EDDHA or FOB in the presence of PS. The enhancement of ⁵⁹Fe absorption and translocation in plants treated with citrate, and the highest ⁵⁹Fe absorption and translocation in plants treated with citrate and PS, indicated that citrate had an additive effect on Fe absorption and translocation in plants. Our results showed that PS effectively played a role in Fe absorption and translocation in plants in the presence of other chelators. Plants treated with any chelators had lower extracellular ⁵⁹Fe in the roots compared with the control.     

Degradation of endosulfan and endosulfan sulfate by white-rot fungus <Emphasis Type="Italic">Trametes hirsuta</Emphasis>

Endosulfan, an organochlorine insecticide, and its metabolite endosulfan sulfate are persistent in environments and are considered toxic. We investigate the possible nontoxic bioremediation of endosulfan. An endosulfandegrading fungus that does not produce endosulfan sulfate was selected from eight species of white-rot fungi. High degradation of endosulfan and low accumulation of endosulfan sulfate were found in cultures of Trametes hirsuta. A degradation experiment using endosulfan sulfate as the substrate revealed that T. hirsuta is able to further degrade endosulfan sulfate following the oxidative conversion of endosulfan to endosulfan sulfate. Endosulfan and endosulfan sulfate were converted to several metabolites via hydrolytic pathways. In addition, endosulfan dimethylene, previously reported as a metabolite of the soil bacterium Arthrobacter sp., was detected in T. hirsuta culture containing endosulfan sulfate. Our results suggest that T. hirsuta has multiple pathways for the degradation of endosulfan and endosulfan sulfate and thus has great potential for use as a biocatalyst in endosulfan bioremediation.     

NH4-N Removal Through Nitrification and Hydrogenotrophic Denitrification in Simple Attached Growth Reactors

To provide good quality of drinking water, a biological system to remove ammonium-nitrogen (NH₄-N) from groundwater was studied in this research. The NH₄-N removal system consists of two attached growth reactors: one for nitrification and the other for hydrogenotrophic denitrification (H. denitrification). The nitrification reactor, fed by the NH₄-N contained water, could remove NH₄-N without any need of aeration. The nitrification efficiency was increased by reactor length; the highest efficiency of 92?% was achieved at the longest reactor of 100?cm. A high Fe in groundwater affected the reactor performance by decreasing the efficiency, while a low inorganic carbon (IC) had no effects. Despite of good efficiency in terms of NH₄-N removal, the nitrification reactor increased the concentration of NO₃-N in its effluent. To treat the NO₃-N, a H. denitrification reactor was set up after the nitrification reactor. Efficiency of the H. denitrification reactor was enhanced by increasing H₂ flow rates. The efficiencies were 3, 27, and 90?% for 30, 50, and 70?mL/min of H₂ flow rates, respectively. It was also found that the NO₃-N contained water (water from the nitrification reactor) had to supply IC (i.e., NaHCO₃ or CO₂) for efficient H. denitrification; however, an on-site reactor showed that it can be achieved even without IC addition. The treated water contained low NH₄-N and NO₃-N of <1.5 and <11.3?mg/L, respectively, which comply with drinking water standards. The good performance of the reactors in terms of high efficiency, no aeration need, and low H₂ supply indicated appropriateness of the system for groundwater treatment.