旋毛虫新生幼虫差减cDNA文库的构建及其步筛选   总被引：3，自引：6，他引：3  

刘明远  黎诚耀  吴秀萍  J F Fabien  付宝权  C Trap  卢强  张西臣  P Boireau 《中国兽医学报》2001,21(4):355-358

利用差减杂交（减法杂交，subtractive hybridization)技术，以旋毛虫新生幼虫（newborn larvae,NBL)的cDNA作为试验方（tester)，以肌幼虫＋成虫的cDNA作为驱动方（driver)，制备新生幼虫差减cDNA,利用T载体构建NBL差减cDNA文库，获克隆株90个，以试验方的差减cDNA第2次PCR产物＋未差减cDNA为试验方探针，以驱动方的差减cDNA第2次PCR产物＋未差减cDNA为驱动方探针，在NBL差减cDNA文库中初筛NBL的期特异性克隆，获初筛克隆24个。这些初筛斯异性克隆进一步用Southern blot确认鉴定，获直阳性期特异性克隆2个（NBL SSC1，NBL SSC2）.DNASIS以及Blaster的分析结果显示，这2个克隆为旋毛虫的2个新基因，其中NBL SSC1编码糖蛋白，NBL SSC2编码丝氨本蛋白酶，本试验为旋毛虫期特异性基困全长序列的调取，分析，鉴定以及强保护性抗原基因的筛选奠定了基础。  相似文献   

Development of an oat-based biorefinery for the production of L(+)-lactic acid by Rhizopus oryzae and various value-added coproducts     

Koutinas AA  Malbranque F  Wang R  Campbell GM  Webb C 《Journal of agricultural and food chemistry》2007,55(5):1755-1761

A novel oat-based biorefinery producing L(+)-lactic acid and various value-added coproducts (e.g., beta-glucan, anti-irritant solution) is proposed. Pearling is employed for sequential separation of bran-rich fractions for the extraction of value-added coproducts. Lactic acid production is achieved via fungal fermentation of Rhizopus oryzae on pearled oat flour. Maximum lactic acid concentration (51.7 g/L) and starch conversion yield (0.68 g/g) were achieved when an oat flour concentration of 116.5 g/L was used. Oxygen transfer played a significant role with respect to lactic acid production and starch conversion yield. Rhizopus oryzae produced a range of enzymes (glucoamylase, protease, phosphatase) for the hydrolysis of cereal flour macromolecules. Enzyme production during fungal fermentation has been reported. The proposed biorefining strategy could lead to significant operating cost reduction as compared to current industrial practices for lactic acid production from pure glucose achieved by bacterial fermentations.  相似文献   

Breakdown of the Scab Resistance Gene Vf in Apple Leads to a Founder Effect in Populations of the Fungal Pathogen Venturia inaequalis     

Guérin F  Le Cam B 《Phytopathology》2004,94(4):364-369

ABSTRACT The recent breakdown of Vf, a major resistance gene to apple scab, provided an opportunity to analyze a population genetic process within the matching virulent subpopulation of the fungus Venturia inaequalis. We utilized the amplified fragment length polymorphism technique and allelic variation at four microsatellite loci to assess genetic structure of 133 isolates of V. inaequalis from a single commercial apple orchard sampled from one cultivar carrying the Vf gene (Judeline) and three cultivars devoid of the Vf gene. Both analyses indicated a strong decrease of the genetic diversity among isolates from the Vf cultivar compared with the high level of diversity among isolates from the three other cultivars. This leads to a high genetic differentiation between virVf and avrVf groups (F(ST) > 0.17). Analyses of the genetic distance between AFLP patterns based on the Jaccard index indicate that all virVf isolates could be assigned to a single clonal lineage. These results lead us to conclude that the clonal structure of the population isolated from the Vf cultivar is an example of a founder effect in response to a resistance gene breakdown and it is likely that this event occurred in the orchard during the sampling year.  相似文献   

Evaluation of a thoracoscopic technique using ligating loops to obtain large lung biopsies in standing healthy and heaves-affected horses     

Relave F  David F  Leclère M  Alexander K  Bussières G  Lavoie JP  Marcoux M 《Veterinary surgery : VS》2008,37(3):232-240

Objective— To evaluate use of pre‐tied ligating loop to perform thoracoscopic, large lung biopsy in normal and heaves‐affected horses. Study Design— Prospective clinical study. Animals— Normal (n=5) and heaves‐affected (n=6) horses. Methods— Lung biopsies, 1 from each hemithorax, were collected thoracoscopically using a pre‐tied ligating loop. Horses were either normal (C) or heaves‐affected with the latter being in remission (Ha) for the initial biopsy and in exacerbation (Hs) for the 2nd biopsy. Clinical variables, PaO₂, and PaCO₂ were used to determine the effect of surgical biopsy. Postoperative pneumothorax was monitored by serial thoracic radiographic examinations. Results— Thoracoscopic lung biopsy (n=29, 22 procedures) was well tolerated by all horses. Complication rate was 31%, including 8 ligature slippage and 1 pulmonary hemorrhage. Intranasal oxygen was administered intraoperatively to 6 horses (2 C, 1 Ha, 3 Hs) with severe hypoxemia or labored breathing. There was a significant decrease in PaO₂ during surgery in horses not supplemented with oxygen. Postoperative pneumothorax (21/22 procedures) detected radiographically resolved within 3 weeks. Conclusion— Thoracoscopic lung biopsy using pre‐tied ligating loops was minimally invasive, relatively inexpensive, and fairly efficient. Heaves‐affected horses tolerated the surgery well, even when in exacerbation; however, the technique was associated with non life‐threatening complications in 31% of the biopsies, most of which required correction with additional ligating loops or more sophisticated instrumentation. Clinical Relevance— Using laparoscopic pre‐tied ligating loop for thoracoscopically‐assisted lung biopsy can be considered in horses with normal and impaired lung function but alternative instrumentation and access to intranasal oxygen must be available to the surgeon in case of complications.  相似文献   

Innate or adaptive immunity? The example of natural killer cells     

Vivier E  Raulet DH  Moretta A  Caligiuri MA  Zitvogel L  Lanier LL  Yokoyama WM  Ugolini S 《Science (New York, N.Y.)》2011,331(6013):44-49

Natural killer (NK) cells were originally defined as effector lymphocytes of innate immunity endowed with constitutive cytolytic functions. More recently, a more nuanced view of NK cells has emerged. NK cells are now recognized to express a repertoire of activating and inhibitory receptors that is calibrated to ensure self-tolerance while allowing efficacy against assaults such as viral infection and tumor development. Moreover, NK cells do not react in an invariant manner but rather adapt to their environment. Finally, recent studies have unveiled that NK cells can also mount a form of antigen-specific immunologic memory. NK cells thus exert sophisticated biological functions that are attributes of both innate and adaptive immunity, blurring the functional borders between these two arms of the immune response.  相似文献   

Potential of gas chromatography-orthogonal acceleration time-of-flight mass spectrometry (GC-oaTOFMS) in flavor research     

Fay LB  Newton A  Simian H  Robert F  Douce D  Hancock P  Green M  Blank I 《Journal of agricultural and food chemistry》2003,51(9):2708-2713

Gas chromatography-orthogonal acceleration time-of-flight mass spectrometry (GC-oaTOFMS) is an emerging technique offering a straightforward access to a resolving power up to 7000. This paper deals with the use of GC-oaTOFMS to identify the flavor components of a complex seafood flavor extract and to quantify furanones formed in model Maillard reactions. A seafood extract was selected as a representative example for complex food flavors and was previously analyzed using GC-quadrupole MS, leaving several molecules unidentified. GC-oaTOFMS analysis was focused on these unknowns to evaluate its potential in flavor research, particularly for determining exact masses. N-Methyldithiodimethylamine, 6-methyl-5-hepten-2-one, and tetrahydro-2,4-dimethyl-4H-pyrrolo[2,1-d]-1,3,5-dithiazine were successfully identified on the basis of the precise mass determination of their molecular ions and their major fragments. A second set of experiments was performed to test the capabilities of the GC-oaTOFMS for quantification. Calibration curves were found to be linear over a dynamic range of 10(3) for the quantification of furanones. The quantitative data obtained using GC-oaTOFMS confirmed earlier results that the formation of 4-hydroxy-2,5-dimethyl-3(2H)-furanone was favored in the xylose/glycine model reaction and 2(or 5)-ethyl-4-hydroxy-5(or 2)-methyl-3(2H)-furanone in the xylose/alanine model reaction. It was concluded that GC-oaTOFMS may become a powerful analytical tool for the flavor chemist for both identification and quantification purposes, the latter in particular when combined with stable isotope dilution assay.  相似文献   

Formation of odorants in Maillard model systems based on l-proline as affected by pH   总被引：2，自引：0，他引：2  

Blank I  Devaud S  Matthey-Doret W  Robert F 《Journal of agricultural and food chemistry》2003,51(12):3643-3650

Formation of the odorants acetic acid, 4-hydroxy-2,5-dimethyl-3-(2H)-furanone (HDMF), 6-acetyl-1,2,3,4-tetrahydropyridine (ATHP), and 2-acetyl-1-pyrroline (AP) was monitored by isotope dilution assays at pH 6, 7, and 8 in Maillard model reactions containing glucose and proline (Glc/Pro) or the corresponding Amadori compound fructosyl-proline (Fru-Pro). In general, higher yields were obtained at pH 7 and 8. Acetic acid was the major odorant with up to 40 mg/mmol precursor followed by HDMF (up to 0.25 mg/mmol), the formation of which was favored in the Fru-Pro reaction systems. On the contrary, ATHP (up to 50 microg/mmol) and AP (up to 5 microg/mmol) were more abundant in Glc/Pro. However, the sensory relevance of the two N-heterocycles was more pronounced on the basis of odor activity values, confirming their contribution to the overall roasty note of the reaction samples. It was also found that formation and decomposition of Fru-Pro were faster at pH 7 as compared to pH 6, explaining in part the preferred formation of the four odorants studied under neutral and slightly alkaline conditions. After 4 h of reaction at pH 7 in the presence of proline, about one-fourth of the glucose was consumed leading to acetic acid with a transformation yield of almost 40 mol %.  相似文献   

In-depth mechanistic study on the formation of acrylamide and other vinylogous compounds by the maillard reaction   总被引：2，自引：0，他引：2  

Stadler RH  Robert F  Riediker S  Varga N  Davidek T  Devaud S  Goldmann T  Hau J  Blank I 《Journal of agricultural and food chemistry》2004,52(17):5550-5558

The formation of acrylamide was studied in low-moisture Maillard model systems (180 degrees C, 5 min) based on asparagine, reducing sugars, Maillard intermediates, and sugar degradation products. We show evidence that certain glycoconjugates play a major role in acrylamide formation. The N-glycosyl of asparagine generated about 2.4 mmol/mol acrylamide, compared to 0.1-0.2 mmol/mol obtained with alpha-dicarbonyls and the Amadori compound of asparagine. 3-Hydroxypropanamide, the Strecker alcohol of asparagine, generated only low amounts of acrylamide ( approximately 0.23 mmol/mol), while hydroxyacetone increased the acrylamide yields to more than 4 mmol/mol, indicating that alpha-hydroxy carbonyls are much more efficient than alpha-dicarbonyls in converting asparagine into acrylamide. The experimental results are consistent with the reaction mechanism based on (i) a Strecker type degradation of the Schiff base leading to azomethine ylides, followed by (ii) a beta-elimination reaction of the decarboxylated Amadori compound to afford acrylamide. The beta-position on both sides of the nitrogen atom is crucial. Rearrangement of the azomethine ylide to the decarboxylated Amadori compound is the key step, which is favored if the carbonyl moiety contains a hydroxyl group in beta-position to the nitrogen atom. The beta-elimination step in the amino acid moiety was demonstrated by reacting under low moisture conditions decarboxylated model Amadori compounds obtained by synthesis. The corresponding vinylogous compounds were only generated if a beta-proton was available, for example, styrene from the decarboxylated Amadori compound of phenylalanine. Therefore, it is suggested that this thermal pathway may be common to other amino acids, resulting under certain conditions in their respective vinylogous reaction products.  相似文献   

Survey of cytokines on ocular surfaces of atopic dogs by multiplex analysis using two sampling methods – a pilot study     

Charline Pressanti  Elodie Ravailhe  Jessie Castellote-Brun  Nicolas Amalric  Line-Alice Lecru  Jevgenija Kondratjeva  Fabien Moog  Daniel Combarros  Jean-Yves Douet  Marie Christine Cadiergues 《Veterinary dermatology》2021,32(6):625-e167

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Testing new compounds for efficacy against Varroa destructor and safety to honey bees (Apis mellifera)     

Cameron J Jack  Kaylin Kleckner  Fabien Demares  Leslie C Rault  Troy D Anderson  Paul R Carlier  Jeffrey R Bloomquist  James D Ellis 《Pest management science》2022,78(1):159-165

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