ras p21 expression in ovine pulmonary carcinoma

We have adapted an enzyme-linked immunoblot assay (ELIBA) for the detection of a c-ras proto-oncogene and oncogene protein products in human cell lines and tumors of 21,000 daltons molecular weight (p21ras) to studies of tissues derived from sheep. In the ELIBA, a double antibody system is used in which p21ras proteins are initially immunoprecipitated from protein extracts with monoclonal antibodies, and subsequently identified using additional anti-ras antibodies. Binding is identified with a non-radioactive enzyme-linked colorimetric detection system. In the present study, the ELIBA system was used to study twenty-seven ovine lung specimens, representing normal lung, inflammatory, and neoplastic lesions. We detected p21ras protein expression in every tissue examined, but the nature and amount of the protein product varied significantly among the tissues examined. Some tissues expressed multiple ras species. Broncho-alveolar carcinoma specimens were most likely to express c-Ki-ras proteins. Mutant proteins of c-N-ras and c-Ki-ras were detected in several bronchoalveolar carcinoma specimens, based on migrational differences between mutant and normal proteins in 15% polyacrylamide gels. The results of this study demonstrate the utility of the ELIBA system for detection of c-ras expression in ovine lung tissues, and demonstrate the ability of the system to discriminate specific ras protein species. The prognostic significance of ras expression in sheep pulmonary carcinoma has yet to be determined.     

Type-I hypersensitivity as a component of eosinophilic myositis (muscular sarcocystosis) in cattle

Eight bovine hearts with lesions of eosinophilic myositis (EM) and 2 bovine hearts without EM lesions were collected at slaughter. Blood samples from these 10 hearts, and the heart of a newborn calf also were collected. Histologically, Sarcocystis cruzi was identified in the 8 hearts with EM lesions and the 2 hearts without EM lesions, but not in the heart of the newborn calf. Serum was harvested from the 10 blood samples and was used in homologous, modified, passive cutaneous anaphylaxis tests. Antigen was prepared from S cruzi bradyzoites isolated from the 2 hearts without EM lesions. Serum samples from the 8 cattle with EM lesions reacted positively to S cruzi antigen. When heat-inactivated IgE in serum (56 C for 4 hours) was used, all passive cutaneous anaphylaxis responses were considered negative. Using ELISA, serum IgE concentrations from the 10 cattle with and without EM lesions were 2.2 to 9 U/ml. As determined by radial immunodiffusion, IgM concentrations were 80 to 215 mg/dl. Immunoglobulin G concentrations were 420 to 2,050 mg/dl, but most were less than or equal to 1,700 mg/dl. Immunoglobulin A concentrations were 0 to 62 mg/dl; 1 steer with EM lesions had 0 mg/dl. Double-gel immunodiffusion confirmed the presence of Sarcocystis-specific precipitating antibodies. Sera from the 10 cattle with and without EM lesions formed at least 1 precipitin band.     

Bovine Leukocyte Adhesion Deficiency in Danish Holstein-Friesian Cattle: I. PCR Screening and Allele Frequency Estimation

Jergensen, C. B., J. S. Agerholm, J. Pedersen and P. D. Thomsen: Bovine leukocyte adhesion deficiency in Danish Holstein-Friesian Cattle I. PCR screening and allele frequency estimation. Acta vet. Scand. 1993,34,231-236.–A screening program for bovine leukocyte adhesion deficiency (BLAD) in Danish Holstein-Friesian cattle has been initiated. During the first months 1611 animals were tested by a PCR based assay. Of these animals 1256, 346, and 8 were assigned normal, BLAD carriers, and BLAD affected animals, respectively One bull, born as a co-twin, showed weak reaction for the BLAD allele on DNA isolated from leukocytes, but a normal genotype on DNA isolated from semen. Chromosome analysis showed that this bull was a blood chimaera. Estimation of the BLAD allele frequency upon the PCR test results showed that around 450 Danish calves born in 1991 might have been affected with the recessive disorder.     

Preliminary investigations into factors that affect plasma aldosterone concentrations in horses

The effect of feeding diets with low, adequate and high sodium contents on plasma aldosterone concentrations in horses and ponies was evaluated using human immunoassay kits. The effect of moderate to high intensity exercise of up to six minutes duration on plasma aldosterone concentrations in three thoroughbred- horses was also investigated. On an adequate sodium diet plasma aldosterone concentrations increased to a peak around four hours after feeding. Little daily variation was found in the pre-feeding aldosterone concentrations over three days. Feeding additional salt resulted initially in no increase in plasma aldosterone concentrations in three out of four animals. After five days all four animals had lower pre-feeding concentrations, an increase in the magnitude of the response to feeding but a decreased rise in absolute concentration. Feeding a diet with a decreased sodium content for several months did not result in a consistent change in the pre-feeding aldosterone concentrations although there were times when all three animals showed an increase in the magnitude of the aldosterone response to feeding. No correlation between changes in the fractional electrolyte excretion values determined and alterations in aldosterone response was found. Exercise resulted in a marked increase in aldosterone concentrations. The expected biological response to feeding and exercise was demonstrated with an acceptable level of reproducibility and repeatability. Samples had similar values when assayed by either of the kits evaluated.     

Hyperplastic canker – a perennial disease of almond caused by Pseudomonas amygdali

The history of hyperplastic canker of almond, caused by Pseudomonas amygdali , its evolution and the present situation in Greece are reviewed. Its main aspects, causal agent, symptomatology, epidemiology and control measures are described. The main characteristics differentiating the pathogen from some other pseudomonads pathogenic to fruit trees are also reported.     

The effects of stubble burning and tillage on soil carbon sequestration and crop productivity in southeastern Australia

Abstract. In Australia, stubble burning and tillage are two of the major processes responsible for the decline of soil organic carbon concentration in cropped soils, and the resulting soil degradation. However, the relative importance of these two practices in influencing the soil organic carbon concentration and the long-term impact on soil quality and productivity are not clear. The effects of stubble burning as practised by farmers in southeastern Australia were evaluated in two field trials, one of 19 years duration, the other of 5 years. Conventional tillage (three tillage passes) led to greater loss of soil organic carbon than stubble burning. Loss of total soil organic carbon attributed to stubble burning in the 0–10 cm layer was estimated to be 1.75 t C ha⁻¹ over the period of the 19-year trial, equivalent to 29% of that lost due to tillage. In the 5-year trial, no change in soil organic carbon due to stubble burning was detectable. Changes in soil quality associated with stubble burning detected in the longer trial included a reduction in macro-aggregate stability, and increases in pH and exchangeable K⁺. Only the latter two were detected in the shorter trial. A higher mean wheat yield (average 0.15 t ha⁻¹) following stubble burning was observed in the 19-year trial but not in the 5-year trial. Research to monitor the longer term effects of stubble burning is needed, and to identify conditions where loss of soil organic carbon is minimized.     

In vitro activity of danofloxacin, tylosin and oxytetracycline against mycoplasmas of veterinary importance

The activities of danofloxacin, a novel fluoroquinolone, and two other antimicrobials were determined in vitro against field isolates of seven Mycoplasma species of veterinary importance isolated from cattle, swine and poultry in five European countries. The minimum inhibitory concentrations (MIC) of danofloxacin, tylosin and oxytetracycline were determined against a total of 68 isolates. Danofloxacin showed excellent activity against isolates of all Mycoplasma species (range 0·008 to 0·5 μg ml⁻¹), but in some isolates there was evidence of reduced sensitivity to tylosin (range 0·008 to 2·0 μg ml⁻¹) and oxytetracycline (range 0·008 to over 16·0 μg ml⁻¹). Danofloxacin was more active than other antimicrobials against, M hyopneumoniae, M dispar and M bovigenitalium, and showed activity similar to that of tylosin against M bovis and M gallisepticum. Tylosin was the most active against M synoviae and M hyosynoviae. Generally, oxytetracycline showed the poorest activity, but was superior to tylosin against M bovigenitalium. A second (final) MIC reading was taken for all isolates 14 or 21 days after the initial reading, and MIC values rose during that time. However, the increase seen in danofloxacin values (typically one to two dilutions) was less than that seen for tylosin and oxytetracycline. It is concluded that danofloxacin is highly active in vitro against all of the Mycoplasma species tested, and thus shows great potential for the treatment of respiratory and other infections caused by Mycoplasma species in cattle, pigs and poultry.     

Aerosol therapy in the equine species

Inhalation therapy plays an increasing role in the management of equine respiratory disorders. Thisalternative to systematic treatment permits a high concentration of medication to act locally while minimizing side effects and residues. In human medicine, literature in this field is prolific and continuously renewed, whereas in veterinary medicine, applications of aerosol therapy are less extensive. This review considers the principles of action of the different types of devices used for inhalation, i.e., nebulization, metered-dose inhalation and dry powder inhalation, describes the technical and practical requirements for their use in the equine species and considers the advantages and disadvantages of each inhalation device. The pharmacological agents currently administered to horses by inhalation are also discussed. Perspectives of aerosol therapy in the equine species, including aerosols already used in human medicine and their potential applications for horses are described.     

Effect of Integration of Fertilizer and Green Manure Nitrogen on Yield Attributes, Nitrogen Uptake and Yield of Lowland Rice (Oryza sativa L.)

Field experiments were conducted at Tamil Nadu Rice Research Institute, Aduthurai, India, during the wet seasons of 1992 and 1993 to study the effect of full and partial substitution of fertiliser N with green manure N (Sesbania rostrata) on nitrogen uptake, yield attributes and yield of rice. The experiment consisted of eight treatments with two levels of N (100 and 200 kg ha⁻¹) and three sources of N application viz., fertilizer, integrated (1:1 fertilizer and green manure N) and green manure N compared to the recommended practice (150 kg fertilizer plus 6.25 t ha⁻¹ (72 kg N) green manure) and a no N control. Nitrogen application markedly increased the N uptake. Combined use of the two N sources at 200 and 222 kg N ha⁻¹ and of single fertilizer N at 200 kg N ha⁻¹ recorded the maximum N uptake, increased the yield attributes such as number of panicles per unit area, weight per panicle, number of total and filled grains per panicle and test weight. At 200 kg N ha⁻¹ full substitution of N by green manure reduced the grain yield but only partial substitution of N by green manure resulted in almost similar yield as single fertilizer N. Thus 200 kg N ha⁻¹ applied in equal proportions of fertilizer and green manure N can be recommended for medium duration rice cultivars.