A preliminary investigation of Ehrlichia species in ticks, humans, dogs, and capybaras from Brazil

A molecular epidemiologic investigation in two Brazilian states (Rondônia and São Paulo) was undertaken to determine if Ehrlichia species responsible for human and animal ehrlichioses in North America could be found in Brazilian vectors, potential natural mammalian reservoirs and febrile human patients with a tick bite history. Samples, including 376 ticks comprising 9 Amblyomma species, 29 capybara (Hydrochaeris hydrochaeris) spleens, 5 canine blood, and 75 human blood samples from febrile patients with history of tick bites were tested by a real-time PCR assay targeting a fragment of the Ehrlichia dsb gene. Ehrlichia DNA was not detected in any tick, capybara or human samples. In contrast, 4 out of 5 dogs contained Ehrlichia canis DNA in their blood, which were sequenced, representing the first report of E. canis infecting dogs in the Amazon region of Brazil. Further studies are needed to evaluate the presence of other agents of human and animal ehrlichioses in Brazil.     

Immunization against 5α-androstenone in boarsL'immunisation contre la 5-androsténone chez le verratImmunisierung gegen 5α-Androstenon in Ebern

The effects of specific immunization against 5α-androstenone have been examined in large, genetically homologous groups of boars reared either to bacon weight (90–95 kg live weight) or to heavy manufacturing weight (115–120 kg live weight). At the lighter weight, immunization significantly (P < 0.05) reduced the concentration of androstenone in the adipose tissue from a mean value of 1.77 (S.E. 0.2) μg g^?1 fat in untreated boars (n=39) to 1.10 (S.E. 0.18) μg g^?1 for animals (n=19) treated with 5α-androstene-3-BSA. In contrast, boars (n=20) treated with 5α-androstenone-11-BSA as immunogen accumulated androstenone to a level of 1.99 μg g^?1 fat (S.E. 0.38). At the heavier weight, immunization reduced the accumulation of androstenone in adipose tissue from a mean value of 1.81 μg g^?1 fat (S.E. 0.22) in untreated boars (n=76) to 1.17 μg g^?1 (S.E. 0.19) for animals (n=22) treated with androstene-3-BSA as immunogen. In contrast, boars (n=21) treated with androstenone-11-BSA as immunogen accumulated androstenone to a mean level of 1.74 μg g^?1 fat (S.E. 0.46). No detrimental side-effects were observed in the immunized animals and the advantages of male-type performance and carcass composition were fully preserved.     

Identification of trichomonadid protozoa from the bovine preputial cavity by polymerase chain reaction and restriction fragment length polymorphism typing.

Accurate identification of the bovine pathogen Tritrichomonas foetus is sometimes complicated by the presence of other trichomonadid protozoa in clinical samples. A highly specific and reproducible approach for differentiating 3 common types of bovine trichomonadid protozoa found in the bovine preputial cavity, T. foetus, Pentatrichomonas hominis, and a Tetratrichomonas species, was developed using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. Universal trichomonadid protozoa primers, TFR1 and TFR2, were used to amplify the 5.85 rRNA gene and internal transcribed spacer regions (ITSRs), and the products were digested with the restriction enzyme HpyCH4IV. Restriction fragment length polymorphism analysis was performed on 55 trichomonad isolates from bovine preputial washing and scraping samples. The RFLP results correlated 100% with 5.85 rRNA gene and ITSR sequence resultsand PCR results with primers specific for T. foetus. The results of this study demonstrate that PCR and RFLP analysis can be used in lieu of DNA sequencing to identify the specific trichomonadid protozoa isolated from the bovine preputial cavity.     

Heart failure caused by gossypol poisoning in two dogs

Two hound-type dogs from the same kennel were admitted in terminal stages of congestive heart failure. An investigation revealed the owner had been feeding the dogs cottonseed meal daily with their kibbled meal. Gossypol toxicosis from feeding this meal caused marked abnormalities in myocardial contractility. Although in severe congestive heart failure, one dog had only minimal dilatation of its heart, as revealed by thoracic radiography. Disseminated intravascular coagulopathy also was diagnosed in this dog. Gossypol is a cumulative toxin; the amount of free gossypol fed was approximately 5.4 to 5.7 mg/kg/day for an unknown duration.     

Effects of intraoperative irradiation on gastric and urinary bladder incisions in the dog

Fourteen adult dogs of mixed breeding were given intraoperative irradiation (25 Gy) after surgical incisions were made into the greater curvature of the stomach and the ventral surface of the urinary bladder. Sequential biopsy samples were obtained 10 days to 180 days after surgical operation. All irradiated stomachs developed gastritis and persistent ulceration of the irradiated field. Microscopic changes induced by irradiation of both the bladder and stomach progressed from severe submucosal edema to severe submucosal fibrosis. A parallel progression of fibrinoid degeneration of the small blood vessels was seen in both organs. Severe gastric ulceration persisted up to 180 days after irradiation, although a degree of mucous neck cell and gastric gland regeneration did occur. Pathologic changes were less severe in the bladder than in the stomach. The bladder had greater resiliency and capability for healing and, in contrast to the stomach, showed a capability to reepithelialize the radiation-induced ulcers. Conclusions of this study are as follows: (a) the canine urinary bladder tolerated intraoperative radiation therapy after tissue resection better than did the canine stomach, (b) the combination of surgical operation and irradiation resulted in a more prolonged and complicated healing pattern than did either procedure alone, and (c) the introduction of a surgical procedure upon irradiated tissue within an undetermined time span relative to irradiation resulted in a similar pattern of disturbed healing.     

The Influence of Heavy Metals and Mineral Nutrient Supply on Bituminaria bituminosa

With a view to the selection of plants for the re-vegetation of contaminated, semi-arid land, two populations of the perennial species Bituminaria bituminosa (Fabaceae) from the south of Spain were studied: one (“LA”) from a non-contaminated soil and the other (“C2”) from a similar soil having elevated total levels of Pb and Zn (1,112 and 4,249 μg g^?1, respectively). For sand-cultured plants receiving nutrient solution, flow cytometry showed that heavy metals, at the concentrations measured in aqueous extracts from contaminated soils, had only slight genotoxic effects on root tip cell nuclei. Both populations were also grown in both soils, in two pot experiments. In the first, shoot biomass of LA and C2 in the contaminated soil was decreased to similar extents, with respect to the “clean” soil. Tissue heavy metal concentrations were unlikely to have been phytotoxic, except in the case of shoot Zn for population LA, but there were tissue deficiencies of P and K for populations LA and C2, respectively. In the second pot assay, the stimulation of growth by NPK fertiliser confirmed that even though this soil had high total heavy metal levels, nutrient availability was the principal factor limiting growth. The lesser transport of heavy metals (Cd, Mn and Zn) to the shoot by the population from the contaminated site is a factor that should be considered when selecting B. bituminosa lines for the phytostabilisation of such sites.     

Inconspicuous Nutrient Laden Surface Runoff from Mature Forest Sierran Watersheds

It is generally held that surface runoff in heavily forested ecosystems is minimal and therefore nutrient fluxes via runoff are unimportant. This is based in large measure on the absence of direct observation or remnant physical evidence. It is further held that protected forests with heavy understory and litter serve as a nutrient sink due to maximum uptake and interception. Our Sierran studies have detected the presence of surface runoff at several sites in the form of both overland and litter interflow with concentrations of NH₄-N as high as 87.2 mg L^?1, NO₃-N as high as 95.4 mg L^?1, and PO₄-P as high as 24.4 mg L^?1. Data suggest that nutrients are derived from the mature O-horizons, and that there has been little contact with the mineral soil or root zone where strong retention and/or uptake of these ions would be expected. Such contributions from overland/interflow could be particularly important in areas where ultra-oligotrophic lakes (e.g., Lake Tahoe) are now trending towards meso-oligotrophic status. We believe that fire exclusion in these systems may have exacerbated N and P inputs to Lake Tahoe and elsewhere by allowing unnatural buildups of O-horizons that are apparently a source of nutrients to surface runoff.     

Estimating stomatal diffusion resistance for Douglas-fir,lodgepole pine and white oak under light saturated conditions

Stomatal diffusion (leaf) resistance (r_s) of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), lodgepole pine (Pinus contorta Dougl. ex Loud.) and white oak (Quercus alba L.) in a variety of natural environments is described during conditions of light saturation as a function of the product of the predawn (base) xylem pressure potential of twigs (ψ_xb) or the soil water potential (ψ_s), and the saturation deficit of the atmosphere (δ_e). This general functional form was derived from an analysis based on an Ohm's law analog for water flow in the soil—plant—atmosphere system. The specific form used in each case was determined using regression analysis, where dependent variables considered were xylem pressure potential of the twigs or leaves (ψ_x) and air temperature (T) as well as δe and ψ_xb (or ψ_s). For three independent sets of Douglas-fir data, it is shown qualitatively that a single function describes the combined data as well as the functions derived for each of three data sets individually. The results imply that it may be possible to describe stomatal response of Douglas-fir, and perhaps other species, over a range of environmental conditions using the same model.     

Phonotaxis of crickets in flight: attraction of male and female crickets to male calling songs

Large numbers of two species of mole crickets flew to loudspeakers playing the appropriate calling song outdoors. Mated females were more frequently captured than unmated ones, and males were 12 percent of the catch. Crickets of three other subfamilies were trapped as they flew to mole cricket songs resembling their own.