Has bovine somatotropin (BST) an effect upon drug disposition? Comparative studies in goats and cattle with sulphadimidine and antipyrine after parenteral administration of BST,zeranol and proligestone

Daily subcutaneous BST injection in lactating cows, bulls and castrated male dwarf goats did not induce significant changes in the pharmacokinetic parameters of antipyrine (AP) and sulphadimidine (SDD). Similarly, no changes were obtained after injection of slow-release BST formulations in lactating cows and non-lactating female goats. In contrast to androgenic hormones, both zeranol and proligestone had no effect upon the disposition of AP and SDD, although both synthetic hormones did induce enhanced plasma somatotropin concentrations. In goats, metabolic effects induced by zeranol and BST included significant reductions in plasma urea values, whereas plasma creatinine levels were somewhat lower after daily BST administration.     

Testing of Imported Potato Genotypes for Potato Spindle Tuber Viroid with a Tomato-intermediate /Electrophoresis Combined Method

The polyacrylamide gel electrophoresis (PAGE) test of Morris & Smith (1977) was evaluated for detection of potato spindle tuber viroid (PSTV) in breeding material. Number, density and mobility of nucleic acid bands in the electropherograms were influenced by genotype and growing temperature. So direct testing of genotypes was not reliable. After an intermediate viroid multiplication in tomato host plants at about 30oC and high irradiance, PSTV was reliably detectable with PAGE in inocula of potato samples of diverse origin. A 4-week incubation period proved to be suitable for inocula with low and high concentrations of a mild strain of PSTV (m-PSTV) as well as a severe strain of PSTV (s-PSTV). If incidence of PSTV is expected to be low, testing can be speeded up by bulking samples. With the combined tomato-intermediate/ PAGE assay, one m-PSTV or one s-PSTV infected leaf disk in 200 healthy ones was consistently detectable. Occasionally gels with a nucleic acid band of about the same relative mobility as the viroid band were found. Evidence that these bands were not caused by viroid is presented. A procedure to resolve such questionable test results is described. Infectivity of s-PSTV was higher than that of m-PSTV. Concentration of viroids in the inoculum influenced appearance of mild or severe symptoms and the rate of symptom production.     

The pharmacokinetics and tissue levels of polymyxin B, colistin and gentamicin in calves

Following a single intravenous injection of polymyxin B, colistin (5 mg/kg, each) and gentamicin (3 mg/kg) to calves, the decline in serum antibiotic concentration generally suggested a three-compartment (open system) pharmacokinetic model. Tissue binding is a dominant factor in the distribution and elimination kinetics of the drugs. Less than 65% of the dose of polymyxin B and colistin was recovered in the urine during 48 h after treatment. Concentrations of nonbound polymyxin B and colistin in the kidney, liver, lung, heart, and skeletal muscles were similar to total (free and bound) serum drug levels, but considerably higher concentrations were found, in bound form, in chloroform-ethanol extracts of these organs.
At 24 h after treatment, more than 50% of the doses of polymyxin B and colistin were present bound to the tissues; the largest amount was in the skeletal muscles. Gentamicin was concentrated in the kidney, predominantly in the free form. At 48 h after treatment the amount of gentamicin in the kidney was 6.3% of the administered dose, being more than five times greater than the corresponding amounts of polymyxin B and colistin.
The extent of tissue uptake of polymyxin B and colistin limits the usefulness of kinetic values, which are derived from the analysis of serum drug levels, for the purpose of designing dosage schedules. The strong affinity of the polymyxins to the muscle tissue, and gentamicin to the kidney, can result in drug residues persisting in the body for several weeks.     

Determination of red blood cell potassium content in horses with diarrhoea: A practical approach for therapy

The concentration of potassium in the red blood cells in 15 horses with severe diarrhoea was determined. The red blood cell potassium content (RBCK⁺) was low compared with levels obtained in normal horses. The decrease in the RBCK⁺ was used to evaluate the total body potassium deficit. This calculated amount was administered orally, following each RBCK⁺ determination. In those horses which recovered, RBCK⁺ content returned to normal levels. During treatment, refilling of the red blood cells with potassium occurred only gradually as long as the diarrhoea persisted. In each case, oral loading with the calculated dose resulted in an improvement of the general condition and no side effects were observed. The importance of using RBCK⁺ levels as a diagnostic and therapeutic parameter is discussed.     

Testing the spatial significance of weed patterns in arable land using Mead's test

There is a need in weed science for statistical tests for patchiness and spatial pattern. The objective of this study was to investigate the performance of Mead’s test for detecting patterns in synthetic data and in real weed counts made in maize, and making a first assessment of its applicability in ecological studies on weeds. In an extension to Mead’s test, made here for the first time, we merge original quadrat count data into rectangular cells of m by n quadrats. Care was taken to rule out the effect of starting point on the test result. Using the synthetic data, we demonstrate the ability of the test to detect both patchiness and homogeneity as deviations from randomness. The first deviation results in right‐sided significance, and the second in left‐sided significance of the test. Analysis of the real weed patterns demonstrated patchiness at many scales for five of the six investigated species and lack of any deviation from randomness in the sixth: Taraxacum officinale. The latter was the only wind dispersing species in the dataset. No deviation towards homogeneity was found in any of the real weed species at any scale. All patchy patterns showed anisotropy, being elongated in the direction of field traffic. As it turns out, Mead’s test is well suited to detect departures from randomness in observed weed patterns and enhances the suite of diagnostic tools that can be employed by weed ecologists.     

Oral treatment with ketoconazole of plantar candidosis in a mute swan

Candida albicans infection of the plantar region of the digit was diagnosed in a mute swan (Cygnus olor). Diagnosis was based on histological examination and on cultures. The pathogenicity of the C. albicans isolate was proven by inoculation in laboratory animals. Oral treatment with ketoconazole resulted in complete clinical recovery; no relapse occurred during a sixteen-month follow-up period.     

THE MOVEMENT OF LABELLED 2,4-D IN YOUNG BARLEY PLANTS

Summary. After the 4- or 5-leaf stage in young barley plants, there is a decrease in the translocation of 2,4-D from the leaves to the root system. It is shown that there is no relation between this phenomenon and ear initiation, which occurs at this stage of development. Movement of 2,4-D out of leaves of the tiller in the axils of the 1st and 2nd leaves was also shown to be very small. There is some evidence for a'block'in the movement of 2,4-D in established grass plants.
La migration du 2,4-D marqué dans l'orge     

Disease resistance of carp, Cyprinus carpio L.: identification of individual genetic differences by bath challenge with atypical Aeromonas salmonicida

Abstract. The present study was undertaken to identify female breeders, resistant or susceptible to disease, which might be used to obtain gynogenetically cloned carp lines differing in disease resistance. Experimentally induced erythrodermatitis was used as the disease model. Firstly, the effect of age on the resistance to bath challenge with atypical Aeromonas salmonicida was examined. These challenges indicated a shift from subacute to chronic infection with increasing age, as shown by a lower survival at 3 and 5 months (both 15%) compared to 10 months of age (60%). Then, to conserve and characterize breeder females, offspring of two females (nos 21 and 38), including F1, F2 and backcross (B1 and B2) progenies, were bath challenged at the age of 3 months. Comparison of the survival data showed a segregation into two groups of progenies: one resistant with nearly 100% survivors (W, F1 and B2), and one relatively susceptible group with 25% (R8 and F2) or 50% (B1) mortality. Analysis of inheritance indicated dominance of the resistant phenotype. Thus, the results identified two breeder females whose (gynogenetic) progeny might be expected to differ in resistance to bath challenge with atypical A. salmonicida.