Effects of deltamethrin on ventral nerve cord activity in the cockroach

The effects of varying concentrations of deltamethrin on a number of the parameters of electrophysiological activity in the cockroach ventral nerve cord have been studied. Deltamethrin, at concentrations greater than 100 nM, caused repetitive firing in the central nervous system (CNS), prior to conduction block, the effect getting faster as the concentration was increased. Whilst 10-nM deltamethrin eventually caused conduction block with no apparent increase in the level of CNS activity, it induced a gradual decrease in the amplitudes of all spike activity. Deltamethrin at 10μM induced a significant increase in the latency of electrically evoked responses, and this was attributed to a synaptic mechanism. It was shown for the first time that 10-μM deltamethrin causes a significant elevation of the extra-axonal K⁺ activity; the possible consequences of this are discussed.     

Infection rates of Theileria annulata in the salivary glands of the tick Hyalomma marginatum rufipes

Theileria annulata was experimentally transmitted to cattle on two occasions by the two-host tick Hyalomma marginatum rufipes. Transmission was transstadial; engorged nymphs fed on Theileria annulata-infected calves transmitted the disease as adults. Salivary glands of all partially fed and incubated adult ticks were heavily infected with Theileria parasites. Immatures attached rapidly and fed successfully on cattle. However, since the immature stages of this species normally feed on birds, this tick is unlikely to be an important vector in the field.     

On the species ofRhyacionia Hübner [1825] (Lepidoptera: Tortricidae) in Turkey

Three forest pest species of the genusRhyacionia Hübner [1825] (Lepidoptera: Tortricidae) that are known to damagePinus species are found in Turkey:R. buoliana ([Denis & Schiffermüller], 1775),R. pinicolana, (Doubleday, 1849) andR. pinivorana (Lienig & Zeller, 1846).R. pinivorana is recorded for the first time from Turkey.R. pinicolana, first recorded in 1999, is now reported for the second time from Turkey. Photographs are presented of adult males and their genitalia of all taxa and the species distribution is shown on a map.     

Clodronate treatment of vitamin D-induced hypercalcemia in dogs

Objective: To determine the effects of clodronate on vitamin D₃‐induced hypercalcemia in dogs. Design: Prospective experimental study. Settings: University research laboratory. Animals: Fourteen healthy intact adult male and female mixed breed dogs. Interventions: Dogs received 7.5 mg of vitamin D₃/kg of body weight once orally and were randomly assigned to 2 groups of 7 dogs each. Dogs in the saline control group were given intravenous infusions of 150 mL 0.9% NaCl solution 24 hours after vitamin D₃ administration. Dogs in the clodronate group were given an infusion of 4 mg/kg of clodronate in 150 mL 0.9% NaCl solution 24 hours after vitamin D₃ administration. Measurements and main results: Clinical signs of vitamin D₃ toxicosis were evaluated 48 hours after ingestion of vitamin D₃. Dogs that were given clodronate had significantly lower serum calcium (Ca), phosphorus (P), urea, and Ca × P values than dogs in the control group on days 4, 7, and 12 after administration. Additionally, alkaline phosphatase activity was significantly lower in the clodronate group compared with dogs in the control group on days 4 and 7. Conclusions: Parenteral administration of clodronate, a biphosphonate compound and osteoclastic activity inhibitor, may be a useful therapy when administered within the first 24 hours after ingestion of toxic doses of vitamin D₃.     

Farm-management and milking practices associated with the presence of Listeria monocytogenes in New York state dairy herds

Knowledge of the relationship between dairy herd management and milking practices with the occurrence of Listeria monocytogenes on dairy farms might assist in the development of intervention strategies aimed at eliminating this organism at the pre-harvest dairy-food-production level. This paper represents a first step towards that goal. We carried out a cross-sectional study to identify farm factors that were associated with isolation of L. monocytogenes from on-farm in-line milk-filters. Data on these factors were collected by personal interview of the farm owners or managers.Logistic regression was used to evaluate the significance of association of each factor while simultaneously controlling for the presence of other factors. A systematic approach was developed in which the bivariable association of the hypothesized factors initially was evaluated. All significant factors were then jointly evaluated in a multivariable logistic model.Farms that used a bucket system had significantly higher odds of L. monocytogenes as compared to farms that used a round-the-barn pipeline milking system (OR=0.35,P=0.05) or milking parlor (OR=0.21,P=0.01). There was a significant association between pre-milking teat disinfection (OR=0.26,P=0.001) and pre-milking examination of abnormal appearance of milk (OR=0.4,P=0.01) against the occurrence of L. monocytogenes. We also found a significant association between the use of E. coli J5 vaccine (OR=3.3,P=0.03) and how long dry-cow therapy had been used on farm (OR=0.34,P=0.04).     

Detection of Cryptosporidium oocysts in soil samples by enzyme-linked immunoassay

An ELISA protocol was adapted for detection of Cryptosporidium parvum oocysts in soil samples and the limit of detection of the test was determined. A modified indirect antigen capture ELISA protocol was developed using monoclonal antibodies against the oocyst outer wall. The accuracy of the ELISA was compared to spiked soil samples and measured in terms of sensitivity and specificity of the test. The performance of the ELISA was evaluated in field soil samples and measured using the kappa-statistics. Similarly, the performance of the ELISA was compared to the concentration flotation method, to a modified concentration flotation method and to a commercial ELISA (ProSpecT) in field fecal and soil samples.The limit of detection of the test was selected to be 10,000 oocysts/g. At this limit of detection, the ELISA had a sensitivity of 95% and specificity of 100%. The agreement between the ELISA and the modified flotation-concentration method in detecting Cryptosporidium oocysts in soil samples was 32% (kappa=0.32). The ELISA had the same relative sensitivity (82%) in comparison to both the flotation and ProSpecT in determining Cryptosporidium-infection status of an animal. The kappa-statistics was 0.26 for both tests. The developed ELISA proved to be a valuable diagnostic test for detecting oocysts in soil samples and has a potential application in determining the infection status of animals.     

Number of Cryptosporidium parvum oocysts or Giardia spp cysts shed by dairy calves after natural infection

OBJECTIVE: To determine the total number of Cryptosporidium parvum oocysts and Giardia spp cysts shed by dairy calves during the period when they are most at risk after natural infection. ANIMALS: 478 calves naturally infected with C. parvum and 1,016 calves naturally infected with Giardia spp. PROCEDURE: Oocysts or cysts were enumerated from fecal specimens. Distribution of number of oocysts or cysts versus age was used to determine the best fitting mathematic function. Number of oocysts or cysts per gram of feces for a given duration of shedding was computed by determining the area under the curve. Total number of oocysts or cysts was calculated by taking the product of the resultant and the expected mass of feces. Results: Intensity of Cparvum oocyst shedding was best described by a second-order polynomial function. Shedding increased from 4 days of age, peaked at day 12, and then decreased. An infected 6-day-old calf would produce 3.89 x 10(10) oocysts until 12 days old. Pattern of shedding of Giardia spp cysts was best described by exponential functions. Intensity of shedding increased from 4 days of age, peaked at day 14, and then decreased. An infected calf would produce 3.8 x 10(7) cysts from day 50 until day 56. CONCLUSIONS AND CLINICAL RELEVANCE: The large number of oocysts and cysts shed indicates that shedding by dairy cattle poses a risk for susceptible calves and people. Estimates reported here may be useful to aid in designing cost-effective strategies to manage this risk.