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91.
Cathepsin L-like proteases are secreted by several parasites including Taenia solium. The mechanism used by T. solium oncospheres to degrade and penetrate the intestine and infect the host is incompletely understood. It is assumed that intestinal degradation is driven by the proteolytic activity of enzymes secreted by the oncosphere. Blocking the proteolytic activity by an antibody response would prevent the oncosphere penetration and further infection. Serine and cysteine proteases including chymotrypsin, trypsin, elastase, and cathepsin L, are secreted by T. solium and Taenia saginata oncospheres when cultured in vitro, being potential vaccine candidates. However, the purification of a sufficient quantity of proteases secreted by oncospheres to conduct a vaccine trial is costly and lengthy. A 53/25 kDa cathepsin L-like fraction partially purified from T. solium cyst fluid was described previously as an important antigen for immunodiagnostics. In this study we found that this antigen is present in the T. solium oncosphere and is also secreted by the cysticercus. This protein fraction was tested for its ability to protect pigs against an oral challenge with T. solium oncospheres in a vaccine trial. IgG antibodies against the 53/25 kDa cathepsin L-like protein fraction were elicited in the vaccinated animals but did not confer protection.  相似文献   
92.
ObjectiveTo assess cardiopulmonary and analgesic effects after administration of ropivacaine into the caudal epidural space of cattle.Study designProspective, single-dose trial.AnimalsEight healthy mixed breed cows aged 8 ± 5 years and weighing 507 ± 112 kg.MethodsCaudal epidural anesthesia was produced in cows with 0.75% ropivacaine (0.11 mg kg?1). Onset time, duration and cranial spread of analgesia were recorded. Heart rate (HR), respiratory rate (fR), rectal temperature (RT), and mean arterial blood pressure (MAP) were measured prior to epidural administration (T0) and at 15, 30, 60, 120, 180 and 240 minutes after epidural administration (T15, T30, T60, T120, T180 and T240). Arterial blood acid-base balance (pH, standard bicarbonate and base excess), gas tension (PaO2, PaCO2, SaO2) and electrolytes (Na+, K+, iCa2+,Cl?) were recorded at T0, T30, T60, T120, T180 and T240. Ataxia was evaluated at T0, T30, T60, T120, T180 and T240 and at 1 hour intervals thereafter until analgesia was no longer present in each animal.ResultsEpidurally administered ropivacaine induced variable analgesia extending bilaterally from the coccyx to S3. Time to onset of analgesia and mean duration in the perineal area were 15 ± 4 and 359 ± 90 minutes, respectively. Respiratory rate and RT increased from T120 to T240 when compared to the value at T0. Ionized calcium and chloride concentrations increased at T180 and T240 when compared to T0. The other variables were not significantly different from baseline values (p> 0.05). Four animals were mildly ataxic.Conclusion and clinical relevanceRopivacaine (0.75%, 0.11 mg kg?1) can be administered by caudal epidural injection to produce prolonged bilateral perineal analgesia with minimal ataxia and cardiopulmonary changes in standing cattle.  相似文献   
93.
94.

Purpose

Soil organic carbon (SOC) and its labile fractions are strong determinants of physical, chemical and biological properties. The objective of the present work was to evaluate the effects of organic amendments (technosol made of wastes and biochar) and Brassica juncea L. on the soil C fractions in a reclaimed mine soil.

Materials and methods

The studied soil was from a former copper mine that was subsequently partially reclaimed with vegetation and wastes. A greenhouse experiment was carried out to amend the mine soil with different proportions of technosol and biochar mixture and planting B. juncea. B. juncea plants can tolerate high levels of metals and can produce a large amount of biomass in relatively short periods of time.

Results and discussion

The results showed that with the addition of biochar and wastes, soil pH increased from 2.7 to 6.18, SOC from undetectable to 105 g kg?1 and soil total nitrogen (TN) from undetectable to 11.4 g kg?1. Amending with wastes and biochar also increased dissolved organic carbon (DOC) from undetectable to 5.82 g kg?1, carbon in the free organic matter (FOM) from undetectable to 30.42 g kg?1, FAP (carbon in fulvic acids removed with phosphoric acid) from undetectable to 24.14 g kg?1 and also increased the humification ratio, the humification index, the polymerisation rate and the organic carbon in the humified fractions (humic acids, fulvic acids and humin). Soils amended and vegetated with B. juncea showed lower FOM values and higher humification index values than the soils amended only with biochar and wastes.

Conclusions

This study concludes that the combined addition of wastes and biochar has a greater potential for both increasing and improving organic carbon fractions in mine soils. The authors recommend the application of biochar and technosol made of wastes as a soil amendment combined with B. juncea on soils that are deficient in organic matter, since they increased all of the SOC fractions in the studied copper mine soil.
  相似文献   
95.
Knowledge about maize varieties is the key to rural households' survival in native Mexico. Native peoples relate to nature in particular ways and they play a crucial role in maintaining biodiversity. This paper discusses the relationship between native women's accumulated knowledge on maize varieties and the laboratory analysis of the species that they manage. Fieldwork was conducted in an Otomí community, San Pablo Arriba, located in the state of Mexico. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
96.
ABSTRACT

In the Pampas, nitrogen fertilization rates are low and soil organic matter impacts crop yield. Wheat (Triticum aestivum L.) yield was related to total soil nitrogen (total N) and to nitrogen mineralization potential (mineralized N) to determine whether the effects of organic matter may be attributed to its capacity to act as a nitrogen source or to the improvement of the soil physical condition. Data of 386 sites from throughout the region comprised in a recent soil survey were used, in which climate and soil properties to 1 m depth were determined. Artificial neural networks were applied for total N and mineralized N estimation using climate and soil variables as inputs (R2 = 0.59–0.70). The models allowed estimating total N and mineralizable N at county scale and related them to statistical yield information. Neural networks were also used for yield prediction. The best productivity model fitted (R2 = 0.85) showed that wheat yield could be predicted by rainfall, the photothermal quotient, and mineralized N. The soil organic matter effect on crop yield seems to be mainly related to its nitrogen mineralization capacity. Using mineralized N as predictor would be a valuable tool for rating soil productivity.  相似文献   
97.
Annatto is a natural food colorant extracted from the seeds of the Bixa orellana L. plant. Annatto is used in Latin American cuisine to add a deep red color as well as distinctive flavor notes to fish, meat, and rice dishes. In the United States, annatto extracts are primarily used to impart orange/yellow hues to cheese and other dairy foods. The objective of this study was to identify and compare volatile compounds present in water- and oil-soluble annatto extracts. Volatile compounds were recovered using dynamic headspace-solvent desorption sampling and analyzed using GC-MS. Compounds were identified by comparison to a mass spectral database, Kovats indexes, and retention times of known standards. Of the 107 compounds detected, 56 compounds were tentatively identified and 51 were positively identified. Volatile profile differences exist between water- and oil- soluble extracts, and annatto extracts contain odorants with the potential to influence food aroma.  相似文献   
98.
We examined the potential antioxidant activity and the immunopharmacological activity of new epicatechin conjugates obtained by depolymerization of grape polymeric flavanols in the presence of cysteamine or cysteine and with or without gallate. The compounds studied were (-)-epicatechin (1), cysteinyl-epicatechin (2), cysteamine-epicatechin (3), (-)-epicatechin gallate (4), cysteinyl-epicatechin gallate (5), and cysteamine-epicatechin gallate (6) When incubated with an erythrocyte suspension, flavanols protected the erythrocyte membrane from hemolysis induced by 2,2'-azobis(2-amidinopropane) dihydrochloride, an azo free-radical initiator. All the epicatechin derivatives tested were more efficient as antioxidant than epicatechin. The most potent antioxidant was compound 6. The compounds were tested for their capacity to modulate IL-1beta and IL-6, which are the main cytokine factors influencing the acute phase of the inflammatory response. (-)-Epicatechin and its related compounds inhibited the production of IL-1beta and IL-6 in whole blood incubated in the presence of Escherichia coli lipopolysaccharide. The most efficient inhibitor of cytokine formation was compound 3.  相似文献   
99.
Byproducts and wastes generated by agricultural, food, and forestry industries contain large amounts of polyphenols, which can be potentially used as sources of natural or semisynthetic antioxidants. This study examined and compared the protection against peroxidative damage induced in erythrocytes and 3T3 cell line of polyphenolic fractions from white grape pomace, pine bark, and witch hazel bark. The work pays special attention to the different degrees of polymerization and galloylation of the extracts to contribute to the understanding of their mechanisms of action. Fractions demonstrated different protections against erythrocyte lipid peroxidation, hemolysis, and 3T3 cytotoxicity caused by H(2)O(2). Galloylation is claimed to be related to antioxidant protective capacity, and it is also responsible for the pro-oxidant effect observed at high doses. The results show that not only the percentage of galloylation but also the degree of polymerization are important modulators of their antioxidant capacity. In this sense, it is crucial that novel polyphenolic fractions were prepared attending a value of 3 for the mean degree of polymerization and did not exceed a 30% of galloylation to reach the highest antioxidant capacity with the lowest cytotoxic effects. For this reason, the grape extracts appear to be the best strategy to fight against hydrogen peroxide cell damage.  相似文献   
100.
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