Partial characterization of the extracellular matrix released onto hydrophobic surfaces by conidia and conidial germlings ofColletotrichum graminicola

The extracellular matrix (ECM) released by conidia ofColletotrichum graminicolawhen incubated on artificial hydrophobic substrata was investigated. Time-course experiments revealed that proteins and carbohydrates were released in the ECM of both ungerminated and germinated conidia. Stains for protein and carbohydrate revealed that part of the ECM remained attached to the substratum after the fungus had been removed. The ECM isolated from substrata where ungerminated conidia had adhered and from substrata where germinated conidia had adhered exhibited the same profiles when analysed by SDS-PAGE for proteins and glycoproteins and by HPLC for carbohydrate analysis. The ECM was found to be composed of glycoproteins with a molecular weight of around 200 kDa. Deglycosylation of the isolated ECM material resulted in the release of a protein with a molecular weight of approx. 116 kDa, indicating that the original protein was extensively glycosylated. Carbohydrate analysis demonstrated that mannose was the predominant sugar. That the ECM remained attached to the surface of the hydrophobic substrata suggests that it has a role in adhesion.     

Comparative study of the microbial profile from bilateral canine otitis externa

Fifty dogs with bilateral otitis externa were studied over a 10-month period. The exudates of both external ears were obtained, using sterile swabs, and microorganisms were isolated according to standard microbiological techniques. Antimicrobial susceptibility testing of Staphylococcus intermedius was done by the agar diffusion method. There was bacterial and/or fungal growth in all of the samples. These were all polymicrobial infections. Anaerobic bacteria were not isolated in any sample. The most common pathogens isolated were S. intermedius and Malassezia pachydermatis. A statistically significant difference (P < 0.05) was observed in the isolation pattern between the right and left ears in 34 of the 50 animals (68%). High resistance rates of S. intermedius strains to penicillin, ampicillin, erythromycin, tetracycline, and clindamycin were found. The results suggest that in bilateral canine otitis externa, each ear should be cultured separately and considered as separate units.     

Note: Flight capacity,parasitism and emergence of five<Emphasis Type="Italic">Trichogramma</Emphasis> (Hymenoptera: Trichogrammatidae) species from forest areas in Brazil

The flight and parasitism capacities and emergence rate of fiveTrichogramma species [T. acacioi (Brun),T. bruni (Nagaraja),T. demoraesi (Nagaraja),T. maxacalii (Voegelé & Pointel) andT. soaresi (Nagaraja)] were compared. The flight capacity of these parasitoids was assessed in test units. A tube was placed inside each test unit with a piece of card with 300Anagasta kuehniella (Zeller) (Lepidoptera: Pyralidae) eggs parasitized by one of theTrichogramma species. The emerged adults inside the test units were classified according to their position as flyers, non-flyers and walkers. Cards withA. kuehniella eggs, parasitized by one of theTrichogramma species, were assessed to determine the parasitism rate and emergence of these natural enemies. The data were submitted to analysis of variance and the means compared by the Scott-Knott test at 5% probability.Trichogramma maxacalii exhibited better flight capacity than the other species, in addition to good parasitism rate and high percentage of emergence. http://www.phytoparasitica.org posting May 10, 2007.     

Parasitic helminth infection in young cattle raised on silvopasture and open-pasture in Southeastern Brazil

More than 95 % of Brazil’s beef production occurs in pastures where parasitic helminths are a serious problem, potentially inhibiting an average annual weight gain of 8 kg per young animal. Current pharmaceutical treatments for parasitic infestation are expensive (estimated to cost Brazil 370 million U.S. dollars per year) and sometimes inefficient due to rapid adaptation of worms to new drugs. The presence of trees in pastures (silvopasture) has proven to be environmentally beneficial, but may favor multiplication of parasites and cause higher infestation rates compared to traditional pastures. This study in Southeastern Brazil compared the weight gains of crossbred Holstein and Gir (Zebu) bovines, 8–24 months of age, under two different grazing systems: open (tree-less) pasture, and silvopasture (primarily “Sucupiras Brancas” at 156 trees ha^?1). Despite the favorable environment for helminths, silvopasture did not increase the worm egg count per gram of animal feces and did not create overall weight or weight gain patterns different from those of animals grazing on the open pasture. The experiment took place from August 2008 to February 2009, encapsulating the transition from the dry to rainy season; a period when worm infection rates are highest, causing the greatest impact in animal development. The significance of this period aside, the results must be taken as indicative due to the short time frame and the extraneous challenges of climate variation, individual immune system resistance development, and natural helminth predator growth conditions.     

Immunolocalization of the Cholesterol Transporters ABCA1 and ABCG1 in Canine Reproductive Tract Tissues and Spermatozoa

The mammalian sperm membrane undergoes cholesterol efflux during maturation and fertilization. Although ATP‐binding cassette (ABC) transporters are known to transport cholesterol through cell membranes in other organs, their presence in canine testis, epididymis and sperm has not been proven to date. Hence, the aim of the present study was to localize the ABC transporters ABCA1 and ABCG1 in canine testicular and epididymidal tissue as well as in spermatozoa membranes. To this end, semen samples from 12 dogs as well as testicles and epididymides of four young and healthy dogs were prepared for immunohistochemistry, respectively. Capacitation and acrosome reaction (AR) were induced in aliquots of the semen samples before immunostaining to assess changes in the expression of ABCA1 and ABCG1. Evaluation by confocal microscopy revealed the presence of both ABCA1 and ABCG1 in canine testicles and of ABCA1 in the epididymides. In spermatozoa, only ABCA1 immunoreactivity was detected, mainly in the region of the acrosome and midpiece. After induction of capacitation, ABCA1 signal persisted in the acrosome but disappeared after AR, indicating a loss of ABCA1 with the loss of the acrosome. We conclude that ABCA1 and ABCG1 are expressed in canine testis, whereas only ABCA1 is expressed in epididymis and spermatozoa membrane, both transporters probably contributing to the regulation of membrane cholesterol content.     

Tantalum Dissolution Rate in Simulant Lung Fluid

The aim of this study is to determine the solubility rate of tantalum contained in pyrochlore, columbite–tantalite and columbite in simulant lung fluid. The International Commission on Radiological Protection (ICRP), in its recommendation for limiting intakes of radionuclide by workers, has consistently recognized that the biological behavior of any specific material after incorporation can significantly diverge from model prevision. Model parameters should be adjusted to adapt the model for each specific substance material in order to estimate the dose due to this element intake. The most recent ICRP publication 66, respiratory tract dosimetry model, point out that information as data like particle size, aerosols solubility and the material chemical compounds are important parameters in the dose coefficients calculation. This paper studies the solubility in Simulant Lung Fluid (SLF) of Ta present in mineral dust particles. For this study 3 minerals were selected: pyrochlore, columbite–tantalite and columbite. Tantalum dissolution in vitro samples were obtained using the Gamble solution and PIXE (Particle Induced X-ray Emission) as analytical technique. In order to characterize the worker exposure to Ta bearing particles, one Brazilian niobium mine was selected. The mineral dust particles were collected using a six-stage cascade impactor and the elemental mass concentrations and the MMAD (Mass Median Aerodynamic Diameter) were determined. Concentrations of radionuclides from natural series of thorium and uranium were also determined. The results show that the workers are exposed to Ta bearing particles in the respirable fraction of aerosols (aerodynamic diameter (d _aer) <2.5 μm) during the mineral processing to obtain Fe–Nb alloy. The solubility in Simulant Lung Fluid (SLF) of Ta present in mineral dust particles depends on the mineral characteristics. The solubility half-time varies between 34 and 62 h depending on the associated mineral.     

Shading effect on physiological parameters and in vitro embryo production of tropical adapted Nellore heifers in integrated crop-livestock-forest systems

Tropical Animal Health and Production - The aim of this study was to evaluate the impact of increased shadow supply in integrated crop-livestock-forest systems on in vitro embryonic development and...