Differing effects of forage and concentrate diets on the oleic acid and conjugated linoleic acid content of sheep tissues: the role of stearoyl-CoA desaturase   总被引：7，自引：0，他引：7  

Daniel ZC  Wynn RJ  Salter AM  Buttery PJ 《Journal of animal science》2004,82(3):747-758

Feeding sheep concentrate-based diets increases the oleic acid content of their tissues, whereas the cis-9, trans-11 conjugated linoleic acid (CLA) content is increased by feeding forage diets. Both these metabolic transformations could be attributable to increased activity of stearoyl-CoA desaturase (SCD). Therefore, the effect of forage or concentrate feeding regimens on the fatty acid composition of sheep tissues were investigated to determine whether any changes are related to an alteration of SCD mRNA levels. Twenty-four ewe lambs were randomly allotted to one of three dietary treatment groups: 1) dehydrated grass pellets, 2) concentrate diet fed to achieve a growth rate similar to that of the dehydrated grass pellets, and 3) the same concentrate diet approaching ad libitum intake. As expected, animals fed ad libitum concentrates grew at a greater (P = 0.001) rate (280 g/d) than those fed either of the other two diets (180 g/d), which were similar. In samples of liver and the three adipose tissue depots studied, the concentration of oleic acid from sheep fed either level of the concentrate diet was greater (P < 0.001) than from animals fed forage. This was associated with an increase (P < 0.05) in the ratio of SCD to acetyl-CoA carboxylase mRNA in adipose tissue and liver. Compared with concentrate-fed, the forage-fed lambs had increased (P < 0.05) levels of the cis-9, trans-11 isomer of CLA and C18:1, trans-11 in all their tissues, although the levels of SCD mRNA were lower. It therefore seems that the increased oleic acid content of sheep tissues in response to concentrate-rich diets is associated with an increase in SCD gene expression. By contrast, the increased concentration of CLA in animals fed forage-based diets is associated with an increase in substrate (C18:1 trans-11) availability.  相似文献   

Monitoring glyphosate residues in transgenic glyphosate-resistant soybean     

Arregui MC  Lenardón A  Sanchez D  Maitre MI  Scotta R  Enrique S 《Pest management science》2004,60(2):163-166

The availability of Roundup Ready (RR) varieties of soybean has increased the use of glyphosate for weed control in Argentina. Glyphosate [(N-phosphonomethyl)glycine] is employed for the eradication of previous crop vegetation and for weed control during the soybean growing cycle. Its action is effective, and low environmental impact has been reported so far. No residues have been observed in soil or water, either of glyphosate or its metabolite, AMPA (aminomethylphosphonic acid). The objective of this work was to monitor glyphosate and AMPA residues in soybean plants and grains in field crops in Santa Fe Province, Argentina. Five sites were monitored in 1997, 1998 and 1999. Individual soybean plants were sampled from emergence to harvest, dried and ground. Analysis consisted in residue extraction with organic solvents and buffers, agitation, centrifugation, clean-up and HPLC with UV detection. In soybean leaves and stems, glyphosate residues ranged from 1.9 to 4.4 mg kg(-1) and from 0.1 to 1.8 mg kg(-1) in grains. Higher concentrations were detected when glyphosate was sprayed several times during the crop cycle, and when treatments approached the flowering stage. AMPA residues were also detected in leaves and in grains, indicating metabolism of the herbicide.  相似文献   

Electronic publishing. Who owns,who pays? U.K., U.S. offer answers for journals     

Malakoff D  Bachtold D 《Science (New York, N.Y.)》2003,301(5629):29

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Toxicology. Arsenic victims to take British science body to court     

Bachtold D 《Science (New York, N.Y.)》2003,300(5622):1066

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Alginate as a new biomaterial for the growth of porcine retinal pigment epithelium   总被引：2，自引：0，他引：2  

Eurell TE  Brown DR  Gerding PA  Hamor RE 《Veterinary ophthalmology》2003,6(3):237-243

Objective Determine the effect of a 3‐dimensional alginate matrix on the growth and differentiation of cells isolated from porcine retinal pigment epithelium (RPE). Procedures Porcine RPE cells were harvested from enucleated eyecups, isolated by differential gravity sedimentation and cultured in either alginate alone (Group 1) or on plastic tissue culture plates followed by alginate (Group 2). Group 1 cells were cultured in alginate to evaluate the efficacy of the matrix as a culture medium. Group 2 cells were initially cultured on plastic to induce dedifferentiation. The cells were then harvested, suspended in alginate beads, and incubated for a second culture period to determine if the induced dedifferentiation was reversible. Results The number of Group 1 cells was significantly greater (P ≤ 0.01) at the end of the culture period. The amount of pigment and cell morphology of Group 1 cells at the end of the culture period was similar to that seen at initial cell isolation. The initial culture of Group 2 cells on plastic showed characteristic features of dedifferentiation marked by the loss of pigment and alterations in microscopic appearance. Secondary culture of dedifferentiated Group 2 cells in alginate beads resulted in a return to pigmentation and characteristic morphology for a majority of the cultured cells. Conclusions Porcine RPE cells can be propagated in alginate culture with a significant increase in cell numbers while maintaining normal morphology. Under the conditions described in the present study, the dedifferentiation of porcine RPE induced by standard in vitro culture methods is reversible.  相似文献   

Human-animal interactions--the importance of examining the whole of a subject     

Mills DS 《Veterinary journal (London, England : 1997)》2003,165(3):180-181

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Use of client-specific outcome measures to assess treatment effects in geriatric,arthritic dogs: controlled clinical evaluation of a nutraceutical     

Gingerich DA  Strobel JD 《Veterinary therapeutics : research in applied veterinary medicine》2003,4(1):56-66

A questionnaire method was designed for dog owners to monitor the orthopedic disabilities of their pets for evaluation of a nutraceutical with joint health claims. Fifty large-breed dogs, 7 to 12 years of age, presenting with signs of osteoarthritis, were randomly allocated to placebo and active treatment groups. Degree of disability was assessed by physical examination, a standard questionnaire on daily activities, and a case-specific questionnaire that monitored specific impairments of each dog. The test product was a special milk protein concentrate (SMPC) from hyperimmunized cows, previously shown to express antiinflammatory and antiarthritic activity in humans. After a 1-week run-in period of dosing with placebo, each dog was randomly assigned to a treatment and given gelatin capsules containing either SMPC or a placebo twice daily for 8 weeks. Overall improvement was noted in 68% and 35% of the SMPC and placebo groups, respectively. Significant (P <.05) improvement in mean standardized and patient- specific questionnaire scores and in owner global assessments was detected in the SMPC group but not in the placebo group. Compared with the placebo group, the treatment response was significantly better in the SMPC group with regard to case-specific scores (P <.001) and owner global assessments (P =.004). The product was well tolerated and serum chemistry findings remained within normal limits.  相似文献   

Multiplex Polymerase Chain Reaction Identification of Single Individuals of the Longidorid Nematodes Xiphinema index, X. diversicaudatum, X. vuittenezi, and X. italiae Using Specific Primers from Ribosomal Genes     

Wang X  Bosselut N  Castagnone C  Voisin R  Abad P  Esmenjaud D 《Phytopathology》2003,93(2):160-166

ABSTRACT The species X. index, X. diversicaudatum, X. vuittenezi, and X. italiae are established (E) or putative (P) vectors of Grapevine fanleaf virus (GFLV) (E), Arabis mosaic virus (E), Grapevine chrome mosaic virus (P), and GFLV (P) nepoviruses of grapevine, respectively. All four species are very closely related taxonomically and their low field densities make them difficult to identify from morphological and morphometrical diagnostic characters when only single or few individuals are detected. To improve diagnostic accuracy, a simple method was developed. The internal transcribed spacer 1 (ITS1) region spanning the 18S and 5.8S ribosomal genes was sequenced in one population of each species using two conserved primers from these genes. The ITS1 fragments were 1,132 bp (X. vuittenezi), 1,153 bp (X. index), 1,175 bp (X. diversicaudatum), and 1,190 bp (X. italiae), i.e., a difference of over 5% between the extremes. The sequence variability made it possible to design species-specific internal sense primers that amplified, in combination with the same antisense ITS1 primer, a single signature fragment (340 bp for X. index, 414 bp for X. italiae, 591 bp for X. vuittenezi, and 813 bp for X. diversicaudatum). Tests with DNA from a single adult or juvenile nematode confirmed the specificity of the primers from diverse isolates or populations. The primers were successfully used in a multiplex test for the reliable detection of two to four mixed species, each represented by a single individual. This multiplex-based diagnostic tool will be particularly useful for successful nematode management practices in vineyards.  相似文献   

Diagnosis of three <Emphasis Type="Italic">Tospovirus</Emphasis> species by rapid immunofilter paper assay     

Paola López?Lambertini  Laura?Williams  Kenichiro?Shohara  Daniel?DucasseEmail author 《Journal of General Plant Pathology》2003,69(5):339-341

The rapid immunofilter paper assay (RIPA) was developed to detect Tomato spotted wilt virus (TSWV), Groundnut ringspot virus (GRSV), and Tomato chlorotic spot virus (TCSV) using antisera against recombinant nucleocapsid (N) proteins of each tospovirus. The two-step RIPA was sensitive enough to detect each pecies specifically in only 30min. This technique is proposed as an excellent tool for routine Tospovirus diagnosis and field epidemiological studies.  相似文献   

United States Department of Agriculture-Agricultural Research Service research on alternatives to methyl bromide: pre-plant and post-harvest   总被引：2，自引：0，他引：2  

Schneider SM  Rosskopf EN  Leesch JG  Chellemi DO  Bull CT  Mazzola M 《Pest management science》2003,59(6-7):814-826

Methyl bromide is a widely used fumigant for both pre-plant and post-harvest pest and pathogen control. The Montreal Protocol and the US Clean Air Act mandate a phase-out of the import and manufacture of methyl bromide, beginning in 2001 and culminating with a complete ban, except for quarantine and certain pre-shipment uses and exempted critical uses, in January 2005. In 1995, ARS built on its existing programs in soil-borne plant pathology and post-harvest entomology and plant pathology to initiate a national research program to develop alternatives to methyl bromide. The focus has been on strawberry, pepper, tomato, perennial and nursery cropping systems for pre-plant methyl bromide use and fresh and durable commodities for post-harvest use. Recently the program has been expanded to include research on alternatives for the ornamental and cut flower cropping systems. An overview of the national research program is presented. Results from four specific research trials are presented, ranging from organic to conventional systems. Good progress on short-term alternatives is being made. These will be used as the foundation of integrated management systems which begin with pre-plant management decisions and continue through post-harvest processing.  相似文献