Quantitation of house dust mite allergens (Der f 1 and group 2) on the skin and hair of dogs

OBJECTIVE: To determine the concentration of house dust mite (HDM) allergens, Der f 1 and group 2, on the skin and hair of dogs and whether associations exist between the presence of Der f 1 and group 2 allergens on the skin and hair of dogs and household and dog characteristics. ANIMALS: 63 pet dogs from 50 homes. PROCEDURE: Dogs were weighed and body surface area in square meters was determined. Skin and hair samples were obtained by vacuuming dogs. Collected dust was analyzed by use of standard ELISA techniques. RESULTS: HDM allergen was detected in 21 of 59 skin and hair samples. Presence of group 2 allergen on skin and hair of dogs was significantly associated with long hair, compared with short or medium length hair. Median house dust sample concentrations of Der f 1 and group 2 allergens were high in homes with dogs that had skin and hair samples that were positive for Der f 1 and group 2 allergens. Dogs with skin and hair samples that were positive for Der f 1 and group 2 allergens resided in homes with a high number of house dust samples that were positive for Der f 1, group 2, or both allergens and in homes with a mean house dust sample allergen concentration of > or =2 microg/g of dust. CONCLUSIONS AND CLINICAL RELEVANCE: Associations exist between environmental HDM allergen concentrations and HDM allergens on the skin and hair samples of dogs. Environmental allergen load is a major factor in accumulation of allergens on the skin and hair of dogs.     

维生素B1和B2的萤光光度同时测定法

探讨了用同步荧光法测定维生素Ｂ１和Ｂ２的操作步骤和条件。维生素Ｂ１和Ｂ２的测定范围分别为质量浓度０．００１￣４．０００ｍｇ／Ｌ，０．０００５￣５．０００ｍｇ／Ｌ。该方法维生素Ｂ１的回收率在１０２％￣１０６％之间，维生素Ｂ２在８５．５％￣１０３．１％之间。     

Evaluation of microbial culture of pooled fecal samples for detection of Mycobacterium avium subsp paratuberculosis in large dairy herds

OBJECTIVE: To evaluate sensitivity of microbial culture of pooled fecal samples for detection of Mycobacterium avium subsp paratuberculosis (MAP) in large dairy herds and assess the use of the method for estimation of MAP prevalence. ANIMALS: 1,740 lactating cows from 29 dairy herds in California. PROCEDURE: Serum from each cow was tested by use of a commercial ELISA kit. Individual fecal samples were cultured and used to create pooled fecal samples (10 randomly selected fecal samples/pool; 6 pooled samples/herd). Sensitivity of MAP detection was compared between Herrold's egg yolk (HEY) agar and a new liquid culture method. Bayesian methods were used to estimate true prevalence of MAP-infected cows and herd sensitivity. RESULTS: Estimated sensitivity for pooled fecal samples among all herds was 0.69 (25 culture-positive pools/36 pools that were MAP positive). Sensitivity increased as the number of culture-positive samples in a pool increased. The HEY agar method detected more infected cows than the liquid culture method but had lower sensitivity for pooled fecal samples. Prevalence of MAP-infected cows was estimated to be 4% (95% probability interval, 2% to 6%) on the basis of culture of pooled fecal samples. Herd-level sensitivity estimate ranged from 90% to 100% and was dependent on prevalence in the population and the sensitivity for culture of pooled fecal samples. CONCLUSIONS AND CLINICAL RELEVANCE: Use of pooled fecal samples from 10 cows was a cost-effective tool for herd screening and may provide a good estimate of the percentage of MAP-infected cows in dairy herds with a low prevalence of MAP.     

Regional risk of exporting cattle seropositive for bluetongue virus from the United States

OBJECTIVE: To create a stochastic model to quantify the risk that shipments of cattle from regions within the United States would contain animals seropositive for bluetongue virus and to determine shipment-level accuracy of serologic testing by use of a competitive ELISA (c-ELISA). SAMPLE POPULATION: 19,216 shipments containing 528,918 cattle and calves. PROCEDURE: Data were obtained on number of animals and state of origin of cattle in export shipments originating within the United States between January 1994 and March 2002. Probability distributions for size of export shipments were determined for all states within the United States, and distributions for agar gel immunodiffusion and c-ELISA accuracy (sensitivity and specificity) were determined from expert opinion and review of the literature. The model simulated selection of a shipment and then determined the probability that a threshold number or percentage of cattle within that shipment would have a positive c-ELISA result. Shipment-level sensitivity, specificity, positive-predictive value, and negative-predictive value were calculated. RESULTS: Substantial differences were evident in the regional probability of a shipment being declared positive, with shipments from northeastern states having the lowest probability and shipments from southwestern states having the highest probability. The c-ELISA had variable predictive values at the shipment level, depending on the threshold used and the prevalence of antibody-positive cattle within the region. CONCLUSIONS AND CLINICAL RELEVANCE: Results from this study will aid importers in making scientifically based decisions regarding risk of importing antibody-positive cattle.     

Unity in function in the absence of consensus in sequence: role of leader peptides in export

Passage of proteins across membranes during export from their site of synthesis to their final destination is mediated by leader peptides that paradoxically exhibit a unity of function in spite of a diversity of sequence. These leader peptides act in at least two stages of the export process: at entry into the pathway and subsequently during translocation across the membrane. How selectivity is imposed on the system in the absence of a consensus among the sequences of leader peptides is the main issue discussed here.     

Aesthetic preferences of non-farmers and farmers for different land-use types and proportions of ecological compensation areas in the Swiss lowlands

Beyond its traditional function of food production, agricultural land offers public amenities such as the protection of natural resources and landscape scenery. This study investigates the preferences of non-farmers and farmers for nine landscape scenarios in the Swiss lowlands. The nine landscapes were the result of a photo editing process combining three land-use types (arable crops, grassland and a mixture of both) and three proportions of ecological compensation areas (0%, 10% and 30%). The landscape photographs were randomly arranged on one page of a paper-based questionnaire which was sent to a random sample of 4000 Swiss households (non-farmers) and 500 farmers. The respondents (1376 non-farmers and 276 farmers) rated each landscape by attractiveness. Both non-farmers and farmers preferred a mixed land-use type or one dominated by arable crops over one dominated by grassland. Non-farmers’ preference ratings were highly influenced by the proportion of ecological compensation areas (ECAs) in the rated landscape: Non-farmers rated a landscape with a mixed land-use type and 30% ECAs highest, whereas farmers rated a landscape dominated by arable crops and 10% ECAs highest. The results indicate that heterogeneous landscapes (mixed land use, high proportion of ECAs) influence scenic beauty positively. Thus, farming practices and agro-environment schemes such as ECAs can have an impact on the visual attractiveness of a landscape.     

Amikacin therapy for Pseudomonas cellulitis in an Amazon parrot

Amikacin sulfate, an aminoglycoside antibiotic, was used successfully to treat a case of severe Pseudomonas cellulitus in an Amazon parrot. Side effects of polyuria and polydipsia occurred, but resolved without treatment 3 weeks after the antibiotic regimen. Amikacin sulfate was given at a dosage of 0.04 mg/g of body weight, IM, twice a day, based on antimicrobial sensitivity results. Amikacin sulfate is indicated for P aeruginosa cellulitis that is resistant to gentamicin sulfate. Although it is potentially nephrotoxic, it can be used successfully in birds without permanent clinically evident renal effects.     

Estimate of digestibility in dairy cows using an indicator method in comparison to the Hohenheimer feed value test

In order to measure the digestibility of feed with an indicator method two trials were realized on the dairy research farm "Karkendamm". The first trial was to test the suitability of TiO2 as an indicator to determine the digestibility in cows. The rate of recovery of the indicator was 98.8% (95.5%-101.9%). The concentration of TiO2 of the rectal samples in the morning (daily or every second day) corresponded very well with the values from total faeces collection. The samples taken in the evening showed lower concentrations. The estimation of digestibility of organic matter led to the same values with the total collection or the indicator method with morning samples. The digestibility derived from evening samples were 1.7-2.3%-units digestibility derived from evening samples were 1.7-2.3%-units lower in comparison to total collection. In the second trial the digestibility derived from the in vitro method "Hohenheimer-Futterwert-Test" and from a digestion trial with 30 cows using the indicator method were compared. The digestibility calculated from the date of the in vivo trial was 9.9%-units lower than the one from the "Hohenheimer-Futterwert-Test". The depression of digestibility was due to the variation in concentrate feeding between cows. If the cows got less than 8 kg concentrates the depression in digestibility was 1.9% when increasing the level of feeding one unit of maintenance requirement. If the cows got more than 8 kg concentrates the depression was 3.1%-units. It could be concluded that the "Hohenheimer-Futterwert-Test" underestimates the digestibility if the level of feeding is increased to a certain extent.     

Evaluation of bluetongue virus diagnostic tests in free-ranging bighorn sheep

Five bluetongue virus (BTV) diagnostic tests were evaluated for use in free-ranging bighorn sheep. We sampled one bighorn sheep population four times between 1989 and 1995. The tests evaluated included virus isolation (VI), polymerase-chain reaction (PCR), serum neutralization (SN), agar-gel immunodiffusion (AGID), and competitive enzyme-linked immunosorbent assay (c-ELISA). The c-ELISA, AGID and SN tests had high levels of agreement in determining serogroup exposure in bighorn sheep. We used maximum-likelihood algorithms to estimate the parameters of each diagnostic test used. Although the c-ELISA and AGID had high sensitivity and specificity, the SN had perfect specificity but lower apparent sensitivity. Due to the potential of cross-reactions among multiple serotypes, results of the SN must be interpreted with caution when assessing serotype exposure in an area where multiple serotypes are endemic. The PCR assay delineated convalescent antibody titers from more-recent infections, and consequently, was pivotal in distinguishing a different exposure pattern between the bighorn sheep and cattle in an adjacent herd. Based on an increasing seroprevalence (50% to 100%), BTV circulated through this bighorn sheep population between 1989 and 1993. This increase in seroprevalence coincided with a bighorn die-off due to BTV infection in June, 1991. An adjacent cattle herd was sampled in 1995 for comparison. The bighorn sheep and adjacent cattle had different patterns of exposure to BTV between 1994 and 1995. There was no evidence that BTV circulated through the bighorn sheep population from 1994 to 1995. In 1995, seroprevalence to BTV decreased to 72%, none of yearling bighorn was seropositive, and all of the 39 bighorn sheep were PCR-negative. In contrast, all adult cattle were seropositive to BTV by c-ELISA and SN, and 4 of the calves were seropositive; 11 of the 24 cattle were PCR-positive, including all five calves. Overall, the pattern of temporal herd immunity in the bighorn sheep appeared to follow a classic epidemic curve, with the appearance and subsequent disappearance of herd immunity coinciding with the 1991 die-off in this population. As low levels of herd immunity and high proportions of susceptible animals are key factors in the development of epidemics, this population of bighorn sheep may be at increased risk for a BTV epidemic in the future.