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31.
Recent studies using several Babesia spp. have demonstrated that these species commonly recognize host sialic acids of red blood cells (RBCs) for their invasion. Glycophorin A (GPA), which is a major carrier of the sialic acids on RBCs, is a possible invasive receptor for Babesia parasites. In the present study, a variant of Babesia rodhaini was successfully isolated from a GPA homozygous knockout (GPA−/−) mouse infected with an Australian strain of B. rodhaini which had originally been unable to replicate in GPA−/− mice. The isolated parasite (designated as an OB1 variant) caused lethal infection to wild-type mice, as in the case of the parent Australian strain. However, although the growth of the OB1 variant in GPA−/− mice was comparable with that in wild-type mice at 1–4 days after infection, the growth was significantly inhibited from day 5 onward, leading to the eventual survival of the GPA−/− mice. Resistance of GPA−/− mice against OB1 infection was lost by splenectomy, although the cytokine responses to the infection in the sera of GPA−/− mice were similar to those of wild-type mice. The autoantibody levels to GPA-defective RBCs in the sera of GPA−/− mice were depressed at a lower level at 0–2 days after infection than those of wild-type mice, while the levels of GPA−/− mice progressively increased and reached comparable levels to those of wild-type mice at day 3 or later. These results indicate that the isolated OB1 variant has a GPA-independent invasion pathway into murine RBCs and suggest that the resistance of GPA−/− mice against infection with the OB1 variant may be attributed to the effective clearance of the parasitized RBCs lacking GPA in the spleen, possibly mediated by preferential autoantibody binding to the RBC membrane.  相似文献   
32.
The effect of feeding rotifers enriched with taurine on the growth performance and survival of larval amberjack Seriola dumerili was investigated. Rotifers were enriched with a commercial taurine supplement at four levels (0, 200, 400, and 800 mg/l). The larvae were fed the enriched rotifers in triplicate from 3 days post-hatch for 7 days under static conditions. The average taurine contents of the rotifers were 1.5, 2.7, 4.2, and 7.2 mg/g dry matter, respectively. The growth of the fish fed rotifers enriched with the taurine supplement at 800 mg/l was significantly (P < 0.05) improved compared with that of the fish fed the rotifers without taurine enrichment. The survival rate improved proportionally up to a taurine supplement level of 400 mg/l, but no significant differences in survival were observed among treatments. The fraction of the larvae with inflated swim bladders did not vary significantly between treatments. Taurine content in the whole fish body increased with the taurine level in the rotifers. These results suggest that taurine enrichment of rotifers is an effective method of enhancing the growth of amberjack larvae.  相似文献   
33.
Methane oxidation activity (MOA), methanotrophic bacteria (MOB), and CH4 emission in a paddy field fertilized with anaerobically digested slurry were compared between two varieties: a fodder rice variety Leaf star (LS) and a normal rice variety Kinuhikari (KN). Average MOA and MOB per unit dry root were significantly higher in KN (7.1?μmol?g?1 CH4?g?1 dry root h?1 and 3.7?×?107 MPN?g?1 dry root, respectively) than in LS (4.3?μmol?g?1 CH4?g?1 dry root h?1, 2.1?×?107 MPN?g?1 dry root), although MOA in the rice root per whole plant was not significantly different since root biomass of LS (1.5?g dry root plant?1) was significantly higher than that of KN (1.2?g dry root plant?1). MOA in the soil ranged from 0.031 to 0.087?μmol?g?1 CH4?g?1 dry soil h?1, but there were no significant differences in both depths (0–5 and 5–15?cm) between the two rice varieties. MOA in the rhizosphere soil was significantly different between the rice varieties at flowering, but not at tillering. Methane emission in the field was lower and MOA and MOB in the rice root were higher in LS than in KN at tillering, but the reverse results were found at flowering and maturity stages. Total CH4 emission during a growing period was not significantly different between LS (27.4?±?16.9?g CH4?m?2) and KN (24.0?±?19.5?g CH4?m?2). There was a significant negative relationship between CH4 emission and rice root MOB (P?<?0.01) or MOA (P?<?0.05) and significant positive relationship was observed between root MOA and MOB (P?<?0.01). This study revealed that choice of rice variety might be an important environmental issue in paddy cultivation since it can influence MOA and MOB in rice root and rhizosphere soil which relate with CH4 emission.  相似文献   
34.
The effect of docosahexaenoic acid (DHA) on the growth performance, survival and swim bladder inflation of larval Seriola dumerili during the rotifer feeding period was investigated in two feeding experiments. Amberjack larvae at 3 day post hatching were fed rotifers enriched with (1) freshwater C hlorella (Chlo), (2) a mixture (2:1, v/v) of Chlo and DHA‐enriched C hlorella (DHA‐Chlo), (3) DHA‐Chlo and (4) DHA‐Chlo and commercial DHA emulsion, in triplicate for 7 days. The average DHA contents of the rotifers were 0.0, 0.4, 1.0 and 1.9 mg g?1 DM respectively. The survival rate was improved by the enrichment of rotifers with DHA‐Chlo alone, and DHA‐Chlo and emulsion. Growth and swim bladder inflation of fish fed rotifers enriched with DHA‐Chlo were significantly (< 0.05) improved, however, with increased levels of DHA further improvement was not found. DHA content in the larval whole body proportionally increased with the DHA level in the rotifers. These results suggest that DHA enrichment of rotifers is effective to improve the growth, survival rate and swim bladder inflation of amberjack larvae. The DHA requirement of amberjack larvae is estimated to be 1.5 mg g?1 on a dry matter basis of rotifers.  相似文献   
35.
AIM: To study the expression and roles of muscarinic cholinergic receptor 3 (M3R) in human small cell lung cancer (SCLC) cells. METHODS: Human SCLC cell lines SBC3 and H82 were cultured in vitro. RT-PCR and Western blotting were used to investigate the expression of M3R. MTT assay and Boyden chamber assay were carried out to determine the roles of cholinergic receptor agonist acetylcholine iodide (ACh) and M3R antagonist 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP) in the proliferation and migration of SBC3 cells. RESULTS: M3R was expressed in SBC3 and H82 cells. The relative protein expression of M3R normalized with β-actin in SBC3 was 2.65-fold higher than that in H82. ACh stimulated SBC3 cell proliferation in a dose-dependent manner. Treatment with ACh at concentrations of 10-4 and 10-3 mol/L significantly stimulated SBC3 cell growth at 48 h and 72 h (P<0.01). SBC3 cell proliferation induced by ACh was inhibited by 4-DAMP in a dose-dependent manner. Pretreatment of the cells with 10-5 mol/L 4-DAMP suppressed the effect of ACh at 48 h (P<0.05). Pretreatment with 4-DAMP at concentrations of 10-6, 10-7 (P<0.05) and 10-5 mol/L (P<0.01) inhibited the effect of ACh at 72 h. Treatment with 10-5 or 10-6 mol/L 4-DAMP alone inhibited the cell proliferation at 48 h (P<0.01) and the inhibitory effect of 4-DAMP at concentration of 10-5 mol/L was stronger than that of 4-DAMP at concentration of 10-6 mol/L at 72 h. ACh increased the cell migration towards fibronectin (Fn) in a dose-dependent manner and ACh at concentration of 10-4 mol/L enhanced the cell migration by about 3 folds. The cell migration stimulated by 10-4 mol/L ACh was almost completely blocked by pretreatment with 4-DAMP at concentration of 10-6 or 10-5 mol/L (P<0.01). CONCLUSION: M3R is expressed in human SCLC cells. The M3R antagonist inhibits SBC3 cell proliferation and migration.  相似文献   
36.
37.
The relationship of steam cooking time with cellular strength of cultivars Chieftain, Kennebec, Russet Burbank and White Rose was compared within and among solids concentrations. Nitrogen fertilization had no discernible effect on cell wall strength. Cell strength of Kennebec and Russet Burbank was similar regardless of solids concentration or cooking time. However, cell strength of Chieftain and White Rose differed with solids concentration and cooking time. Knowledge of cell strength and its characteristics with cooking time appear important for understanding the differences in textural quality that exists between cultivars.  相似文献   
38.
The oil content of par-fried frozen French fries prepared by two methods, conventional and freeze-leached, was not affected by blanch temperatures when blanched for 15 minutes. Melting points of the frying oil did affect the oil content of par-fried French fries. The differences were variable and could not be explained by melting point alone. Blowing the potato strips with ambient air after the par-fry and cooling below the melting point of the frying oil had no effect on the oil content of the frozen product. Contrary to previous reports, the oil content of the French fries increased significantly as the par-frying temperature was increased from 160.0 to 185°C (320 to 365°F) with the greatest increase occurring between 171.1 and 185.0°C (340 and 365°F). The French fries par-fried 1 min at 171.1 and 185.0°C (340 and 365°F) were judged to have identical quality after finish frying 3 minutes at 185.0°C (365°F). A lower par-fry temperature or possibly a shorter par-fry time at the higher temperature would be an advantage to the processor who could use less oil and energy without adversely affecting the quality of the final consumable product.  相似文献   
39.
This study investigated the effect of different light intensities on feeding, growth and survival of early stage leopard coral grouper Plectropomus leopardus larvae. Four different light intensities (0, 500, 1000 and 3000 lx) were used and larvae were kept under constant light conditions from 0 day after hatching (DAH) to 5 DAH. The larvae were fed a small S-type of Thai strain rotifers at a density of 20 individuals/mL from 2 DAH. The number of rotifers in larval digestive organ and total length of larvae were examined at 3 h intervals between 04:00 and 22:00 h on 3 DAH, and thereafter at 6 h intervals until the end of the experiment (5 DAH). Four experimental trials of the larval rearing were repeated using by 60 kL mass-scale rearing tanks. The results indicate that coral grouper larvae are visual feeders and their food intake increases with increasing light intensity. Food intake of larvae reared at 3000 lx was significantly higher than those reared at 0–1000 lx on 3 DAH despite being the first-feeding day (< 0.01). On 4 DAH, total length of larvae reared at 3000 lx was significantly larger than those reared at the lower light intensities (0, 500 and 1000 lx), and thereafter light intensity significantly influenced larval feeding and growth until the end of the experiment. Survival on 5 DAH did not show a significant difference between light intensities, but survival rate at 3000 lx and 1000 lx had a tendency to be higher than those reared at the lower light intensities (0 and 500 lx). In contrast, larvae reared at 0 lx exhibited stagnant and/or negative growth. These results indicate that light intensity is significantly the factor affecting larval feeding, growth, and survival in coral grouper larvae under the rearing conditions.  相似文献   
40.
We determined the changes in the contents of three gamma-glutamyl peptides and four sulfoxides in garlic cloves during storage at -3, 4, and 23 degrees C for 150 days using a validated high-performance liquid chromatography method that we reported recently. When garlic was stored at 4 degrees C for 150 days, marked conversion of the gamma-glutamyl peptides, gamma-L-glutamyl-S-allyl-L-cysteine and gamma-L-glutamyl-S-(trans-1-propenyl)-L-cysteine (GSPC), to sulfoxides, alliin and isoalliin, was observed. Interestingly, however, when garlic was stored at 23 degrees C, a decrease in GSPC and a marked increase in cycloalliin, rather than isoalliin, occurred. To elucidate in detail the mechanism involved, the conversion of isoalliin to cycloalliin in both buffer solutions (pH 4.6, 5.5, and 6.5) and garlic cloves at 25 and 35 degrees C was examined. Decreases in the concentration of isoalliin in both the solutions and the garlic cloves during storage followed first-order kinetics and coincided with the conversion of cycloalliin. Our data indicated that isoalliin produced enzymatically from GSPC is chemically converted to cycloalliin and that the cycloalliin content of garlic cloves increases during storage at higher temperature. These data may be useful for controlling the quality and biological activities of garlic and its preparations.  相似文献   
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