Elimination of salicylic acid in goats and cattle

Sodium salicylate was administered to cattle and goats IV and PO according to a crossover design. Total urinary excretion of SA and its metabolites was measured for 3 days after dosing. Salicyluric acid (SUA) was the only metabolite detected in urine of either species. Recovery of sodium salicylate and SUA in goats amounted to 67.9 and 34.6% of the dose, respectively, after IV administration. After oral dosing, total recoveries were 30.2% (sodium salicylate) and 71.7% (SUA) of dose. By comparison, cattle excreted significantly (P less than 0.05) less sodium salicylate (54.0%) and more SUA (49.9%) after IV dosing. The same pattern was observed after oral administration, wherein cattle excreted less than 12% as sodium salicylate and more than 99% as SUA. In both species, almost 90% of the drug excreted as sodium salicylate was found in urine within the first 12 hours after an IV dose and within 24 hours after oral dosing. The excretion of SUA was somewhat slower in both species, especially after oral administration. The data suggested that there were only quantitative differences in the metabolism and elimination of sodium salicylate between the 2 species, with cattle excreting a higher proportion of the drug as the glycine conjugate SUA.     

A dominant antigenic epitope on SARS-CoV spike protein identified by an avian single-chain variable fragment (scFv)-expressing phage

Severe acute respiratory syndrome (SARS) is a newly emergent human disease, which requires rapid diagnosis and effective therapy. Among antibody sources, immunoglobulin Y (IgY) is the major antibody found in chicken eggs and can be used as an alternative to mammalian antibodies normally used in research and immunotherapy. In this study, phage-expressing chicken monoclonal scFv antibody was chosen and characterized with phage display antibody technology. Truncated fragments of SARS-CoV spike protein were cloned in pET-21 vector and expressed in BL-21 Escherichia coli (E. coli) cells. After purification, the purity of these recombinant spike proteins was examined on SDS-PAGE and their identity verified with Western blot analysis using anti-his antibodies and sera from convalescent stage SARS-CoV-infected patients. Using these bacteria-derived proteins to immunize chickens, it was found that polyclonal IgY antibodies in the egg yolk and sera were highly reactive to the immunogens, as shown by Western blot and immunocytochemical staining analysis. A phage displaying scFv library was also established from spleen B cells of immunized chicken with 5 x 10(7) clones. After four panning cycles, the eluted phage titer showed a 10-fold increase. In sequence analysis with chicken germline gene, five phage clones reacted, with large dissimilarities of between 31 and 62%, in the complementarity-determining regions, one dominant phage 4S1 had strong binding to fragment Se-e, located between amino acid residues 456-650 of the spike protein and this particular phage had significantly strong binding to SARS-CoV-infected Vero E6 cells. Based on the results, we conclude that generating specific scFv-expressing phage binders with the phage display system can be successfully achieved and that this knowledge can be applied in clinical or academic research.     

江苏省土壤钾素的供应能力与钾肥施用问题

随着我国农业生产的不断发展,复种指数和单位面积产量的不断提高,南方不少地区施用钾肥已成为夺取高产稳产的重要条件之一,有关土壤钾素状况和钾肥施用问题愈来愈受到人们的重视.江苏省地处我国南北的过渡带,其土壤是否缺钾,钾肥的需要程度如何,是生产实践上有待明确的一个问题.     

Aflatoxicol: major aflatoxin B1 metabolite in rat plasma

Aflatoxicol, a carcinogenic metabolite of the foodborne carcinogen aflatoxin B1 previously known only as a bioreduction product in vitro, was identified as the major aflatoxin metabolite in the plasma of Sprague-Dawley rats, a susceptible species, that had been doses orally or intravenously with aflatoxin B1 labeled with carbon-14. Alfatoxicol, however, was not detected in the plasma of similarly dosed mice and monkeys, which are both resistant to aflatoxin B1-induced cardinogenesis. The formation of aflatoxicol both in vitro and in vivo may be an indicatory of species sensitivity to aflatoxin-induced carcinogenesis and may be useful in the prediction of human susceptibility.     

艾灸对免疫系统作用的研究——Ⅰ.艾灸对家兔胸腺依赖淋巴细胞作用的研究

本项试验以酯酶染色法和E-玫瑰花环形成试验,对兔抢风、百会穴灸前及灸后不同时间(3、6、12、24、48、72、96小时)测定淋巴细胞值%,经148只次的测定结果表明:艾灸对T淋巴细胞表现有明显的激励作用(P<0.01),并呈现一定的规律性;灸后3小时T淋巴细胞值%开始升高,至24小时达高峰,然后逐渐下降.艾灸对T淋巴细胞的激励作用,可能是艾灸治病的机理之一。预示着,测定T淋巴细胞值有可能作为判定艾灸疗效的一种手段。     

Stable RNA/DNA hybrids in the mammalian genome: inducible intermediates in immunoglobulin class switch recombination

Although it is well established that mammalian class switch recombination is responsible for altering the class of immunoglobulins, the mechanistic details of the process have remained unclear. Here, we show that stable RNA/DNA hybrids form at class switch sequences in the mouse genome upon cytokine-specific stimulation of class switch in primary splenic B cells. The RNA hybridized to the switch DNA is transcribed in the physiological orientation. Mice that constitutively express an Escherichia coli ribonuclease H transgene show a marked reduction in RNA/DNA hybrid formation, an impaired ability to generate serum immunoglobulin G antibodies, and significant inhibition of class switch recombination in their splenic B cells. These data provide evidence that stable RNA/DNA hybrids exist in the mammalian nuclear genome, can serve as intermediates for physiologic processes, and are mechanistically important for efficient class switching in vivo.     

Automatic screening of biological specimens by optical correlation

An optical analog correlation technique was used to detect morphologic abnormalities in rat liver cells. The method employs an optical matched filter for correlating a test pathological specimen with a control specimen. Experimental results show appreciable promise that such an optical correlator can be employed as a tool for rapid mass screening of a variety of pathological specimens.     

Anti-inflammatory effects of resveratrol and oligostilbenes from Vitis thunbergii var. taiwaniana against lipopolysaccharide-induced arthritis

Vitis thunbergii Sieb. and Zucc. var. taiwaniana Lu is an endemic plant in Taiwan used as a dietary supplement for bone health. In this study, human chondrocytes were induced to produce COX-2, MMP-3, -13, and PGE(2) by LPS. An (18)F-FDG microPET imaging system was used to evaluate the anti-inflammatory arthritic effects in vivo. Six stilbenes, resveratrol (1), (+)-ε-viniferin (2), ampelopsin C (3), ampelopsin A (4), (-)-vitisin B (5), and (+)-vitisin A (6), were isolated from the stem part of V. thunbergii, which displayed the strongest PGE(2) inhibition. Among these compounds, 1 significantly decreased COX-2 activity, PGE(2), MMP-3, and -13 production in vitro, and (18)F-FDG uptake and serum PGE(2) in rabbits in vivo. Anti-inflammatory effects were enhanced through the combined usage of 1 and other oligostilbenes. Taken together, the synergistic effects of 1 and oligostilbenes resulted in stem part extracts with lower 1 content displaying the better anti-inflammatory arthritis effects.     

Hibiscus protocatechuic acid or esculetin can inhibit oxidative LDL induced by either copper ion or nitric oxide donor

Oxidation of low-density lipoprotein (LDL) could increase the incidence of atherosclerosis. Previous studies have shown that copper and sodium nitroprusside (SNP) possess the ability to oxidize LDL in a dose-dependent condition. They increase the existing negative charge in LDL and increase the electrophoretic mobility. In this study, we used protocatechuic acid (PCA) and/or esculetin (ECT) to define the antioxidative activity in oxidative LDL by relative electrophoretic mobility (REM) and thiobarbituric acid-relative substances (TBARS). The data showed that ECT and PCA possessed stronger antioxidative activity than vitamin E in oxidative LDL. A previous study showed that the level of oxidative LDL can be determined by the cholesterol degradation and fragmentation of Apo B. Our results showed that Cu(2+)-mediated oxidative LDL can induce 31% cholesterol degradation and significant fragmentation of Apo B. Both PCA and ECT exhibited remarkable ability to rescue the cholesterol degradation and Apo B fragmentation. Taken together, both PCA and ECT showed strong potency to inhibit oxidative LDL induced by copper or an NO donor. Additionally, their nontoxic characteristics elevated the possibility for their use in the daily diet; and should further prevent atherosclerosis effectively.     

Molecular phylogenetic relationships of puffer fish inferred from partial sequences of cytochrome b gene and restriction fragment length polymorphism analysis

Phylogenetic relationships among puffer fish were investigated by comparing cytochrome b gene sequences and restriction endonuclease assays of 16 species from Taiwan. DNA was prepared for sequencing by PCR. No variation in sequences was detected among individuals within each species. Direct estimates of mitochondrial cytochrome b gene sequence divergence among 16 puffer fish were from 3.41 to 31.78%. Different restriction patterns were found among 16 puffer fish with 10 restriction endonucleases, whereas no variation in patterns was detected among individuals within each species. The polymorphisms obtained by RFLP have provided a new set of genetic markers for the accurate identification of sibling puffer species. It is the first molecularly based study of puffer diversity and sheds light on the evolution and taxonomy of this major puffer fish family.