Ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME) can affect distribution pattern of inorganic N in soil

Ethyl tert-butyl ether (ETBE) and tert-amyl methyl ether (TAME) are synthetic compounds that are used as gasoline additives in order to reduce emissions from vehicles. In the present study, effects of these compounds were investigated on the dynamics of inorganic N in soil. Therefore, soil samples with different water contents were contaminated with ETBE and TAME, respectively. It could be shown that in the presence of TAME and ETBE, NH₄⁺–N accumulated; moreover, ETBE addition to soil resulted in increased NO₂⁻–N concentrations. These results indicated for the first time that ETBE and TAME can affect nitrification in soil. Thus, their impact on soil ecology should be investigated more intensively.     

The corky root rot pathogen Pyrenochaeta lycopersici secretes a proteinaceous inducer of cell death affecting host plants differentially

Pathogenic isolates of Pyrenochaeta lycopersici, the causal agent of corky root rot of tomato, secrete cell death in tomato 1 (CDiT1), a homodimeric protein of 35 kDa inducing cell death after infiltration into the leaf apoplast of tomato. CDiT1 was purified by fast protein liquid chromatography, characterized by mass spectrometry and cDNA cloning. Its activity was confirmed after infiltration of an affinity-purified recombinant fusion of the protein with a C-terminal polyhistidine tag. CDiT1 is highly expressed during tomato root infection compared with axenic culture, and has a putative ortholog in other pathogenic Pleosporales species producing proteinaceous toxins that contribute to virulence. Infiltration of CDiT1 into leaves of other plants susceptible to P. lycopersici revealed that the protein affects them differentially. All varieties of cultivated tomato (Solanum lycopersicum) tested were more sensitive to CDiT1 than those of currant tomato (S. pimpinellifolium). Root infection assays showed that varieties of currant tomato are also significantly less prone to intracellular colonization of their root cells by hyphae of P. lycopersici than varieties of cultivated tomato. Therefore, secretion of this novel type of inducer of cell death during penetration of the fungus inside root cells might favor infection of host species that are highly sensitive to this molecule.     

Reactivity of lysine moieties toward an epoxyhydroxylinoleic acid derivative: aminolysis versus hydrolysis.

Epoxyols are generally accepted as crucial intermediates in lipid oxidation. The reactivity of tert-butyl (9R,10S,11E,13S)-9, 10-epoxy-13-hydroxy-11-octadecenoate (11a,b) toward lysine moieties is investigated, employing N(2)-acetyllysine 4-methylcoumar-7-ylamide (12) as a model for protein-bound lysine. The prefixes R and S denote the relative configuration at the respective stereogenic centers. Independent synthesis and unequivocal structural characterization are reported for 11a,b, its precursors, and tert-butyl (9R,10R,11E, 13S)-10-(?5-(acetylamino)-6-[(4-methyl-2-oxo-2H-chromen-7-yl)amino ]-6 -oxohexyl?amino)-9,13-dihydroxy-11-octadecenoate (13a-d). Reactions of 11a,b and 12 in 1-methyl-2-pyrrolidone (MP) and MP/water mixtures at pH 7.4 and 37 degrees C for 56 days show formation of the aminols 13a-d to be favored by an increased water content. The same trend is observed for hydrolytic cleavage of 11a,b to tert-butyl (E)-9,10, 13-trihydroxy-11-octadecenoate (14) and tert-butyl (E)-9,12, 13-trihydroxy-10-octadecenoate (15). Under the given conditions, aminolysis proceeds via an S(N)2 substitution, in contrast with the S(N)1 process for hydrolysis. In the MP/water (8:2) incubation, 15. 8% of 12 has been transformed to 13a-d and 10.5% of 11a,b hydrolyzed to the regioisomers 14 and 15 after 8 weeks, respectively. Aminolysis of alpha,beta-unsaturated epoxides by lysine moieties therefore is expected to be an important mode of interaction between proteins and lipid oxidation products.     

Mydriatic effect of topically applied rocuronium bromide in tawny owls (Strix aluco): comparison between two protocols

Objective To evaluate the mydriatic efficacy of a neuromuscular blocking agent (rocuronium bromide) applied topically to only one eye of nocturnal birds of prey and to assess for any general and/or local adverse effects due to its use. Animal studied Twelve healthy adult tawny owls (Strix aluco) were randomly divided in two groups. Procedures Six birds (Group 1) received a single dose of 0.35 mg of rocuronium bromide. The second group of subjects (Group 2) received two doses of 0.35 mg of rocuronium bromide (total 0.70 mg/eye). In both groups, the curariform agent was instilled topically. Pupil diameter was measured with a pupillary gauge in 10 min intervals for a total of 100 min and then every 20 min for a total of 240 min. The assessment of the pupillary light reflex was performed using a standard light source during pupillary size recording. Results Maximal pupillary diameter was 11.5 ± 0.3 mm for Group 1 and 11.0 ± 0.6 mm for Group 2 and no statistically significant differences were detected among the two groups. The maximal pupillary diameter was achieved at T80 for Group 1, and at T60 for Group 2. A complete fundus examination was possible on all treated eyes of subjects of both groups. The drug did not cause any noticeable adverse effects in any of the examined birds. Conclusion Results of the present study suggest that a single topical administration of 0.35 mg of rocuronium bromide to the eyes of healthy tawny owls results in sufficient mydriasis to allow for a complete examination of the fundus.     

Effect of levothyroxine administration on hemostatic analytes in Doberman Pinschers with von Willebrand disease

Levothyroxine administration has been suggested to be an effective treatment for canine von Willebrand disease (vWd), but evidence supporting this treatment is lacking. Effects of levothyroxine administration were evaluated in 8 euthyroid Doberman Pinschers with plasma von Willebrand factor (vWf) concentrations < 15%, characteristic of type 1 vWd. Levothyroxine (0.04 mg/kg PO q12h) and placebo were administered for 30 days in a 2-period, 2-treatment, double-blinded, crossover design with a 30-day washout period between treatments. Buccal mucosal bleeding time (BMBT), plasma vWf concentration (vWf: Ag), vWf collagen binding activity (vWf:CBA), factor VIII coagulant activity (FVIII:C), and serum concentrations of total thyroxine (T4), free thyroxine (fT4), 3,5,3'-triiodothyronine (T3), and thyroid-stimulating hormone (TSH) were measured on days 0, 2, and 30 of each treatment period. The 8 dogs (1 male, 7 females) had markedly low plasma vWf:Ag (mean, 8.9%; reference range, 70-180%) and vWf:CBA (mean, 11.1%; reference range, >70%). Response to placebo versus levothyroxine treatment was not significantly different between groups at day 0, 2, or 30 for BMBT, vWf:Ag, vWf:CBA, and FVIII:C. Serum T4, fT4, and T3 concentrations were significantly higher and serum TSH significantly lower in the levothyroxine-treated group than in the placebo group at days 2 and 30. Administration of levothyroxine at 0.04 mg/kg caused laboratory evidence of hyperthyroidism but did not affect plasma FVIII:C and vWf:Ag concentrations or vWf-dependent collagen binding and BMBT. The results of this study failed to identify a direct action of levothyroxine supplementation on plasma vWf concentration or activity in euthyroid Doberman Pinschers with vWd.     

Cultivation and expansion of canine Schwann cells using reexplantation

Despite the numerous available possibilities for the surgical treatment of peripheral nerve lesions found in the dog, the success of these treatments is often unsatisfactory. It has been proven that Schwann cells (SC) have a positive influence on the regeneration of nerve stumps. Implanting a guidance channel seeded with autologous SC at the lesion site could be a new therapeutic approach. The aim of this research was to investigate the in vitro cultivation and expansion of canine SC as the main requirement for the treatment referred to above. Biopsies were carried out on 17 nerve samples originating from dogs of different breed, age, gender and condition. The reexplantation method was employed, followed by dissociation using hyaluronidase, collagenase and trypsin and further expansion. The samples were divided into six groups which were treated with a varying combination of mitogens (forskolin, bovine PEX, choleratoxin, heregulin). To obtain the quantities of SC, the specimens were immunostained by a p75-antibody. By employing a growing number of agents it was possible to obtain an increase in both the quantity of cells and purity of cultures. A maximum of 16x10(5) cells per millilitre of suspension was achieved. The largest SC purity measured 27.1%. The maximum SC quantity achieved was 43.3x10(4) SC per millilitre.     

Cutaneous and ocular habronemiasis in horses: 63 cases (1988-2002)

OBJECTIVE: To describe clinical manifestations of cutaneous and ocular habronemiasis in horses and evaluate outcome of treatment. DESIGN: Retrospective study. ANIMALS: 63 horses. PROCEDURE: The diagnosis was made on the basis of history, clinical signs, and identification of calcified concretions (sulfur granules) in lesions. Histologic examination of biopsy specimens was used to confirm the diagnosis. Case horses were compared with a control population of 12,720 horses examined during the same period. RESULTS: Arabians, gray horses, and horses with diluted coat colors were overrepresented; Thoroughbreds were underrepresented. Lesions were identified most often during the summer and early fall. The medial canthus of the eye, male genitalia, third eyelid, and distal portions of the extremities were the most commonly affected locations. Twenty-five lesions were biopsied, and results of histologic examination were consistent with a diagnosis of habronemiasis. However, nematode larvae were seen in only 11 (44%) biopsy specimens. Treatment consisted of surgical removal (7 horses) or medical treatment (56) consisting of debulking granulation tissue and topical, intralesional, or systemic treatment with corticosteroids. All horses were treated with ivermectin. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that cutaneous and ocular habronemiasis should be considered when examining a horse during the summer months with a proliferative, moist, granulomatous lesion. Treatment should be aimed at decreasing the size of the lesion, reducing inflammation, and preventing recurrence. In general, the prognosis was good, and healing occurred within a few weeks. Fly control and regular deworming with ivermectin are recommended to reduce the incidence of habronemiasis.     

Case-control study of factors associated with fibrinous pericarditis among horses in central Kentucky during spring 2001

OBJECTIVE: To identify factors significantly associated with an epidemic of fibrinous pericarditis during spring 2001 among horses in central Kentucky. DESIGN: Case-control study. ANIMALS: 38 horses with fibrinous pericarditis and 30 control horses examined for other reasons. PROCEDURE: A questionnaire was developed to solicit information regarding a wide range of management practices and environmental exposures from farm owners or managers. RESULTS: The following factors were found in bivariate analyses to be significantly associated with an increased risk of pericarditis: being from a farm with mares and foals affected by mare reproductive loss syndrome, exposure to Eastern tent caterpillars in or around horse pastures, younger age, shorter duration of residence in Kentucky and at the farm of current residence, being fed hay grown outside Kentucky, a lack of access to pond water, access to orchard grass for grazing, and a lack of direct contact with cattle. In multivariate logistic regression analyses, only variables related to caterpillar exposure and age were significantly associated with fibrinous pericarditis. CONCLUSIONS AND CLINICAL RELVANCE: Results suggest that fibrinous pericarditis in horses may be associated with mare reproductive loss syndrome. Exposure to Eastern tent caterpillars was the greatest risk factor for development of fibrinous pericarditis. The distribution of times of diagnosis of fibrinous pericarditis was consistent with a point-source epidemic.