Plasma cortisol responses to three cortico-trophic preparations in normal dogs

Objective To compare cortisol responses to three corticotrophic preparations in normal dogs.
Animals Eight clinically normal dogs (four intact males, four intact females) of medium size.
Procedures Each dog received four treatments on four separate occasions in a duplicated Latin square pattern. Treatments were two adrenocorticotrophin (ACTH) preparations given intramuscularly at 2.2 U/kg, one of the ACTH preparations given intramuscularly at 1 U/kg and a synthetic polypeptide with ACTH-like activity (tetracosactrin, cosyntropin) given intravenously at 5 μg/kg. Plasma samples were taken for cortisol assay before and at 0.5, 1, 2 and 4 h after treatment.
Results Plasma cortisol concentrations were similar with the two ACTH preparations and at both dose rates. Tetracosactrin produced smaller mean peak cortisol concentrations, which tended to occur earlier than with ACTH, and smaller values for the area under the curve of plasma cortisol concentration from zero time to 4 h.
Conclusion The findings suggest that canine adrenal function can be tested adequately by giving ACTH intramuscularly at 1 U/kg and measuring plasma cortisol in samples taken at 0 and 2 h, or by giving tetracosactrin intravenously at 5 μg/kg and determining cortisol concentration at 0 and 1 h.     

Inhibition on human liver cytochrome P450 3A4 by constituents of fennel (Foeniculum vulgare): identification and characterization of a mechanism-based inactivator

Fennel, a seed of Foeniculum vulgare, is used as a culinary spice and traditional medicine. The methanolic extract of fennel showed a characteristic of mechanism-based inactivation on erythromycin N-demethylation mediated by human liver microsomal cytochrome P450 3A4 (CYP3A4). The present study was conducted to identify the fennel constituent having the inhibition. Thirteen compounds have been isolated from a methanol extract of fennel and tested for their inhibition on CYP3A4. Among them, 5-methoxypsoralen (5-MOP) showed the strongest inhibition with an IC50 value of 18.3 microM and a mixed type of inhibition. In addition, with the preincubation time of 20 min only 5-MOP showed preincubation time dependency; the IC50 value decreased from 18.3 microM with a preincubation time of 0 min to 4.6 microM with a preincubation time of 20 min. Further investigation on 5-MOP showed the characteristics of time-dependent inhibition, requirement of NADPH, lack of protecting effect of nucleophiles, and recovery of CYP3A4 activity by the competitive inhibitor. This result suggests that the inhibitory activity of CYP3A4 by 5-MOP was a mechanism-based inactivation. The kinetic parameter for mechanism-based inactivation was characterized by a KI value of 15.0 microM and a kinact value of 0.098 min(-1).     

Host resistance to lung infection mediated by major vault protein in epithelial cells

The airway epithelium plays an essential role in innate immunity to lung pathogens. Ribonucleoprotein particles primarily composed of major vault protein (MVP) are highly expressed in cells that encounter xenobiotics. However, a clear biologic function for MVP is not established. We report here that MVP is rapidly recruited to lipid rafts when human lung epithelial cells are infected with Pseudomonas aeruginosa, and maximal recruitment is dependent on bacterial binding to the cystic fibrosis transmembrane conductance regulator. MVP was also essential for optimal epithelial cell internalization and clearance of P. aeruginosa. These results suggest that MVP makes a substantial contribution to epithelial cell-mediated resistance to infection.     

The adsorption characteristics of soils and removal of cadmium and nickel from wastewaters

The interactions between the adsorption characteristics of 27 experimental soils and the sorption of Cd and Ni from the municipal wastewaters were investigated in this study. The removal of these elements from soil solution was followed for 50 days. All the adsorption characteristics, except cation exchange capacity and organic matter, were significantly correlated to the sorption of Cd after one day shaking. After 7 days of shaking, none of the soil adsorption characteristics except free CaCO₃ was significantly correlated to Cd removal from wastewater. The soil saturated paste pH and suspension pH were strongly correlated to Cd sorption throughout this experiment. The behavior of Ni in soils was different from that of Cd. Surface area, total Fe, and total Al were significantly correlated to Ni sorption. The correlation between Ni removal and pH was the strongest than any other parameter studied. After 7 days shaking, clay content and total Ca were not significantly correlated to Ni sorption. The cation exchange capacity of the soils was not significantly correlated to Cd or Ni sorption in this experiment. It seems that in the experimental soils, concentration of Cd and Ni were probably not controlled by adsorption process. The precipitation process was probably playing a major role in the removal of these elements from the municipal wastewaters. As observed in this experiment, the cation exchange capacity of experimental soils was a poor parameter to define sorption capacity of these soils for Cd and Ni. The guidelines for determining the soil sludge load, which are mainly based on the cation exchange capacity of soils, should be revised.     

Stage Sensitivity of Mungbean (Vigna radiata L. Wilczek) to an Elevated Level of Carbon Dioxide

An experiment was undertaken using open‐top chambers to study the effect of CO₂ enrichment on crop growth and to assess the variation related to the time of CO₂ exposure. In general, enriched CO₂ conditions (600 ± 50 p.p.m.) in the chamber positively affected the growth and development of mungbean (Vigna radiata), a short‐duration (60–65 days) summer pulse crop. However, there was significant variability in the effect of the crop stage/time of CO₂ exposure. It was observed that high CO₂ exposure at an early growth stage [0–20 days after germination (DAG)] had a larger effect than that at a later growth stage (21–40 DAG). The experiment also provided a means of assessing the short‐ and long‐term effects of elevated CO₂ on the carbon exchange rate at both stages of exposure. The study revealed that the sensitivity of plants to high CO₂ was more pronounced with respect to net photosynthetic rate. The overall photosynthetic activity gave greater growth and development of plants under high CO₂.     

Molecular phylogeny and pathotyping of Fusarium solani: a causal agent of Dalbergia sissoo decline

Sissoo (Dalbergia sissoo), commonly known as shisham, is amongst the finest woods of South Asia, but ‘wilt’ disease has caused a rapid decline in this species. The cause of the disease remains uncertain. The aim of this study is to identify the causal agent of the disease and characterize isolates made from diseased trees, based on genomic data and variations in virulence. Samples of infected roots, stems and the ooze exuded from infected trees were obtained from plants showing symptoms in different geographical regions of India for the isolation of microorganisms. Isolates were used to inoculate healthy plants. Based on the morphological characteristics, genus‐ and species‐specific PCR, and in silico analysis of 5.8S rDNA‐ITS regions, of the 38 fungal isolates, 24 and 14 were identified as Fusarium solani and Fusarium sp., respectively. In a pathotyping study, eighteen F. solani isolates, isolated from roots and stem parts of symptomatic plants, induced typical wilt symptoms when inoculated through soil and roots on D. sissoo seedlings of 1–15 months in age. The population of F. solani was the highest in infected roots and the lowest in parts of stems, gradually decreasing with height, and was isolated constantly up to approximately 40% height of the seedling. F. solani isolates used in inoculations were successfully re‐isolated from the rhizosphere, infected roots and wilted stems, as confirmed using isolate‐specific DNA fingerprints. Molecular phylogenies based on rDNA‐ITS sequences showed that the 38 isolates fell into 2 groups. Group I comprised of F. solani isolates from D. sissoo and F. solani sequences in the NCBI GenBank database, whereas group II included Fusarium isolates other than F. solani. These results are helpful in developing integrated control measures for this highly variable pathogen and to establish a base for future population studies.     

Possible parachordoma in a dog

Abstract

CASE HISTORY: A 15-mm diameter mass developed in the S/C tissue overlying the right lateral gluteal muscle of a 6½-year-old female Flat-coated Retriever.

PATHOLOGICAL FINDINGS: Cytological preparations following aspiration of the mass were highly cellular and consisted of a population of large polygonal cells containing single to multiple nuclei, large prominent nucleoli, and intracytoplasmic vacuoles. Histologically, the neoplasm consisted of similar large cells surrounded by thick fibrous connective tissue trabeculae. The large polygonal cells reacted positively with antibodies against vimentin, low- and high-molecular-weight variants of cytokeratin (AE1/AE3), but not with antibodies to desmin or glial fibrillary acidic protein (GFAP).

DIAGNOSIS: The clinical, gross, histological and immunohistochemical findings are similar to those reported for parachordomas in humans. Neither recurrence nor metastases were noted 18 months after surgical excision of the mass.

CLINICAL RELEVANCE: This is the first reported case of a possible parachordoma in a dog, a benign tumour with cytological features of malignancy.     

Pseudogout in two dogs

Extract

Pseudogout is a common condition in elderly people in which sudden onset of intense joint pain and synovitis develop. Peri-synovial calcium crystal deposition is the cause of the synovitis rather than the uric acid deposition in common gout. It is a rare condition in dogs, having only been reported twice before. Two dogs presenting with acute lameness and pyrexia showed many macrophages and occasional neutrophils containing intracellular crystals on cytological examination of synovial fluid. The crystals were single or multiple, small to large, clear, square or rhomboid-shaped, weakly birefringent and resembled those described for pseudogout. Occasional crystals were also present free in the matrix. Non-steroidal anti-inflammatory drugs that are effective in reducing pain in people with pseudogout provided no relief to either patient, but twice daily oral prednisolone therapy was successful. Dosage was gradually tapered as clinical signs improved over a period of 6 weeks.