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51.
52.
Genotyping of Giardia duodenalis from Southern Brown Howler Monkeys (Alouatta clamitans) from Brazil
Volotão AC Júnior JC Grassini C Peralta JM Fernandes O 《Veterinary parasitology》2008,158(1-2):133-137
Giardia duodenalis is a widespread intestinal protozoan that can infect humans and animals, both domestic and wild. Independent of host, infections present with the same symptoms. However, based on host specificity, Giardia isolates have been grouped into genotypes A to G. Parasites of assemblage A and B are known to infect humans, in addition to primates and a wide variety of mammals. In Brazil, hitherto Giardia genotypes were defined only for humans and domestic animals. To evaluate the genotypes of different Giardia present among other animals, fecal samples from 28 Southern Brown Howler Monkeys (Alouatta clamitans) kept in captivity from South Brazil were screened for G. duodenalis using parasitological methods. All of them were asymptomatic, but positive for Giardia. The genotype of the G. duodenalis circulating among these animals was ascertained by molecular typing, performed using amplification and sequencing of the beta-giardin gene. Sixteen of 28 samples were successfully amplified by PCR and sequencing of this gene s revealed that all of them were of the genotype A1. These findings suggest that A. clamitans represent a potential risk of environmental contamination of a G. duodenalis genotype that also infect humans, and therefore can be considered a potential reservoir for G. duodenalis of a genotype that can also infects humans. Therefore, these results highlight a potential public health problem due to the epidemiological and molecular evidence for anthropozoonotic transmission. 相似文献
53.
Ahmad Yar Ranjha Richard C. Peralta Antonio Maria Requena Howard M. Deer Majid Ehteshami Robert W. Hill Wynn R. Walker 《Irrigation Science》1992,13(1):9-14
Summary Effects of furrow irrigation designs, water management practices (irrigation scheduling, etc.), soil types and pesticide parameters on pesticide leaching were simulated. A hydraulic kinematic-wave irrigation model was used to estimate water infiltration for alternative furrow lengths and inflow rates. A one-dimensional simulation model then simulated the movement of pesticides through soils following furrow irrigation. Potential ground-water contamination by pesticides can be reduced by an integrated use of the best management practices (BMPs) such as careful selection and use of pesticides, efficient furrow irrigation designs and improved water management techniques (irrigation scheduling, etc.). Procedures for designing an appropriate furrow irrigation system for a particular site and pesticide, and selecting pesticides for a particular site, crop and furrow irrigation system are illustrated. These procedures are being used to develop decision support computer models for developing different BMPs for pesticide-agricultural management decisions. 相似文献
54.
Two trials were carried out to determine the effect of feed acidification upon Salmonella carriage in market-age pigs. In the first trial, the administration for the last 14 weeks of the fattening period of a commercial pelleted feed added with 0.6% lactic acid plus 0.6% formic acid (Lac-Formic-1.2) was compared to an unacidified standard diet (STD). A second experiment was carried out in two herds of growing pigs (Herd I, 3000 pigs; Herd II, 900 pigs) in which three different diets were assayed during the last 8-9 weeks of the fattening period: a diet containing 0.8% formic acid (Formic-0.8), a diet containing 0.4% lactic acid plus 0.4% formic acid (Lac-Formic-0.8) and a STD. In the first experiment, serological evolution of the infection was examined by ELISA and microbiological cultures (rectal samples and mesenteric lymph nodes) were also done. Feed intake by pen and the individual weight of the animals were also measured. In the second trial, blood, rectal samples and mesenteric lymph nodes were collected at slaughter in both herds (30 pigs per experimental group). In the first experiment, the acidified diet (Lac-Formic-1.2) reduced Salmonella carriers in mesenteric lymph nodes (Fisher's exact P < 0.01). In the second trial, Lac-Formic-0.8 diet significantly reduced Salmonella seroprevalence compared to the STD (P = 0.001) in both herds. Also Lac-Formic-0.8 and Formic-0.8 diets in Herd II showed a lower faecal excretion and Salmonella carriage in mesenteric lymph nodes than the STD (P < 0.05). Our results suggest that the administration of a combination of lactic and formic acids at the levels used in this study could be used to reduce Salmonella prevalence in finishing pigs. 相似文献
55.
Stéphane Marchandeau Dominique Pontier Jean-Sébastien Guitton Jér?me Letty David Fouchet Jacky Aubineau Francis Berger Yves Léonard Alain Roobrouck Jacqueline Gelfi Brigitte Peralta Stéphane Bertagnoli 《Veterinary research》2014,45(1):26
The role of maternal antibodies is to protect newborns against acute early infection by pathogens. This can be achieved either by preventing any infection or by allowing attenuated infections associated with activation of the immune system, the two strategies being based on different cost/benefit ratios. We carried out an epidemiological survey of myxomatosis, which is a highly lethal infectious disease, in two distant wild populations of rabbits to describe the epidemiological pattern of the disease. Detection of specific IgM and IgG enabled us to describe the pattern of immunity. We show that maternal immunity attenuates early infection of juveniles and enables activation of their immune system. This mechanism associated with steady circulation of the myxoma virus in both populations, which induces frequent reinfections of immune rabbits, leads to the maintenance of high immunity levels within populations. Thus, myxomatosis has a low impact, with most infections being asymptomatic. This work shows that infection of young rabbits protected by maternal antibodies induces attenuated disease and activates their immune system. This may play a major role in reducing the impact of a highly lethal disease when ecological conditions enable permanent circulation of the pathogen. 相似文献
56.
Laszlo Horvath Ilona Peszlen Perry Peralta Steve Kelley 《Wood Science and Technology》2011,45(2):303-314
The investigation of genetically modified trees requires rapid and reliable techniques to measure the mechanical properties
at an early age in order to give timely feedback to forest geneticists. In this study, transmittance near-infrared (NIR) spectroscopy
was used to predict the green mechanical properties of 1- and 2-year-old transgenic and wild-type aspen. Green modulus of
elasticity (MOE) in three-point bending and green ultimate compression strength (UCS) parallel to the grain were predicted
from the NIR spectra of dry wood meal pellets. Green UCS had strong correlation (R
2 = 0.91) and green MOE had good correlation (R
2 = 0.78) with the spectra. The latter could be explained by the moderate correlation of MOE with the lignin content of the
transgenic samples, suggesting that besides chemical composition MOE also depends on anatomical properties. The ratio of performance
to deviation value suggested that the calibration model of both UCS (2.94) and MOE (1.91) could be used for screening. 相似文献
57.
An M2 muscarinic receptor subtype coupled to both adenylyl cyclase and phosphoinositide turnover 总被引:20,自引:0,他引:20
A Ashkenazi J W Winslow E G Peralta G L Peterson M I Schimerlik D J Capon J Ramachandran 《Science (New York, N.Y.)》1987,238(4827):672-675
To investigate whether a particular receptor subtype can be coupled to multiple effector systems, recombinant M2 muscarinic receptors were expressed in cells lacking endogenous receptor. The muscarinic agonist carbachol both inhibited adenylyl cyclase and stimulated phosphoinositide hydrolysis. The stimulation of phosphoinositide hydrolysis was significantly less efficient and more dependent on receptor levels than the inhibition of adenylyl cyclase. Both responses were mediated by guanine nucleotide binding proteins, as evidenced by their inhibition by pertussis toxin; the more efficiently coupled adenylyl cyclase response was significantly more sensitive. Thus, individual subtypes of a given receptor are capable of regulating multiple effector pathways. 相似文献
58.
Bruni R Rossi D Muzzoli M Romagnoli C Paganetto G Besco E Choquecillo F Peralta K Lora WS Sacchetti G 《Fitoterapia》2006,77(7-8):538-545
The hydroalcoholic extract of Maytenus krukovii bark was investigated for its in vitro mutageno-protective activities by means of the Ames Salmonella/microsome assay. The extract showed an inhibitory effect in both T98 and T100 strains against the mutagenic activity of promutagen 2-aminoanthracene but was not protective against directly acting mutagens sodium azide and 2-nitrofluorene. When tested as a radical scavenger and antioxidant it produced a dose-dependent inhibition. The extract did not show significant antibacterial properties, and was weakly active against dermatophyte and phytopathogenic fungi, but inhibited the growth of phytopathogen Pithyum ultimum. 相似文献
59.
Migration of bisphenol A (BPA) from epoxy can coatings to jalapeño peppers and an acid food simulant
Munguia-Lopez EM Peralta E Gonzalez-Leon A Vargas-Requena C Soto-Valdez H 《Journal of agricultural and food chemistry》2002,50(25):7299-7302
Effects of heat processing, storage time, and temperature on migration of bisphenol A (BPA) from an epoxy type can coating to an acid food simulant and jalape?o peppers were determined. Commercial jalape?o pepper cans (8 oz, dimensions 211 x 300) were stored at 25 degrees C for 40, 70, and 160 days. A solution of 3% acetic acid was canned in 211 x 300 cans from the same batch used for jalape?o peppers. Heat processing was applied to two-thirds of the cans, and the remaining cans were not heat processed. Cans were stored at 25 and 35 degrees C for 0, 40, 70, and 160 days. Results showed that there is a minimal effect of heat treatment. An effect of storage time on migration of BPA during the first 40 days at 25 degrees C was observed. An increase on migration of BPA was observed with storage time at 35 degrees C. The highest level of migration was 15.33 microg/kg of BPA at 160 days at 35 degrees C. A correction factor of approximately 0.4 was calculated for migration under simulating conditions of storage compared to the real ones. The highest level of BPA found in jalape?o peppers cans, surveyed from three supermarkets, was 5.59 +/- 2.43 microg/kg. Migration of BPA, performed according to the European and Mercosur conditions, was 65.45 +/- 5.29 microg/kg. All the migration values found in this study were below those legislation limits (3 mg/kg). 相似文献