Epibulbar melanoma in a cat

In a nine-year-old female cat, the diagnostic procedure, therapy and differential diagnoses of a rare, primary, malignant, epibulbar melanoma are presented. Post-operatively no recidivation or metastases occurred within 18 months.     

Age-related resistance to Pseudomonas syringae pv. tomato is associated with the transition to flowering in Arabidopsis and is effective against Peronospora parasitica

As plants mature it has been observed that some become more resistant to normally virulent pathogens. The ability to manifest the Age-Related Resistance (ARR) response in Arabidopsis to Pseudomonas syringae pathovars tomato (Pst) coincided with the transition to flowering in plants both delayed and accelerated in the transition to flowering. ARR was also associated with a change in PR-1 gene expression, such that young plants expressed PR-1 abundantly at 3 days post inoculation (dpi) while mature plants expressed much less. The Arabidopsis ARR response requires SA accumulation via isochorismate synthase (ICS1) [24]. ICS1 was expressed one dpi with virulent and avirulent Pst in both young and mature plants. The ARR response was also effective versus avirulent Pst providing an additional 4-fold limitation in bacterial growth. Arabidopsis ARR was found to be ineffective against two necrotrophs, Erwinia carotovora subspecies carotovora (bacterium) and Botrytis cinerea (fungus) and one obligate biotroph, Erysiphe cichoracearum (fungus). However, mature wild type, SA-deficient sid2 and NahG plants supported little growth of the obligate biotrophic oomycete, Peronospora parasitica. Therefore ARR to P. parasitica appears to be SA-independent, however the level of ARR resistance was somewhat reduced in these mutants in some experiments. Thus, there may be numerous defence pathways that contribute to adult plant resistance in Arabidopsis.     

Biosynthesis of Depsipeptide Mycotoxins in Fusarium

The cyclic hexadepsipeptide enniatin is known as a phytopathogenic compound from Fusaria causing necrosis and wilt. The molecule consists of three alternating residues each of a branched chain amino acid and D-hydroxyisovaleric acid (D-Hiv). Enniatins are synthesized by a 347kDa multienzyme (enniatin synthetase) via a thiol template mechanism. The corresponding gene esyn1 has an open reading frame of 9393 nucleotides and harbours two modules, one responsible for D-hydroxy acid activation and one for L-amino acid activation with an integrated N-methyltransferase domain. Such methyltransferases build an homologous group among N-methyl peptide synthetases. Enniatins are synthesized by step-wise condensation of dipeptidol building blocks in an iterative manner resembling fatty acid synthesis. A key enzyme in enniatin biosynthesis is the NADPH-dependent D-2-hydroxyisovalerate dehydrogenase, that supplies enniatin synthetase with D-Hiv. Enniatins contribute to the wilt toxic character of Fusaria. Virulence was significantly reduced in F. avenaceum after disruption of the esyn1 gene.     

The Effect of Inoculation Treatment and Long-term Application of Moisture on Fusarium Head Blight Symptoms and Deoxynivalenol Contamination in Wheat Grains

Fusarium head blight (FHB) is an important disease of wheat, which can result in the contamination of grains with mycotoxins such as deoxynivalenol (DON). Artificial inoculation of flowering ears with conidial suspensions is widely used to study FHB diseases. Our goal was to compare four inoculation treatments in which a conidial suspension was sprayed on flowering ears and to study the effect of the application of moisture during kernel setting and filling with a mist-irrigation system. Ten wheat genotypes were inoculated with a DON-producing Fusarium culmorum strain. Inoculation treatments varied in time of application of the inoculum (morning or evening) and in the method of controlling humidity during inoculation (bagging or mist irrigation). A wet season was simulated with a mist-irrigation system, keeping the crop canopy wet for at least 26 days after flowering. The severity of FHB symptoms (area under disease progress curve (AUDPC)), yield loss and DON contamination in the grains were determined. AUDPC data obtained with the different inoculation treatments were highly correlated (r=0.85–0.95). Mist irrigation after inoculation resulted in a higher mean disease severity, but in a overall lower toxin contamination as compared to the non-irrigated treatments. Genotypic differences in DON accumulation were present: for one wheat line toxin contamination significantly increased when irrigated, while two genotypes accumulated significantly less toxin. The closest relationships (r=0.73–0.89) between the visual symptoms and the DON content were obtained under moderate mean infection pressure. This relation between visual symptoms and the DON content deteriorated at higher infection levels.     

Linking mesoscale landscape heterogeneity and biodiversity: gardens and tree cover significantly modify flower-visiting beetle communities

Landscape Ecology - Maintaining biodiversity in multifunction landscapes is a significant challenge. Planning for the impacts of change requires knowledge of how species respond to landscape...     

Evaluation of a combined transcutaneous carbon dioxide pressure and pulse oximetry sensor in adult sheep and dogs

OBJECTIVE: To evaluate a combined transcutaneous carbon dioxide pressure (tcPCO(2)) and pulse oximetry sensor in sheep and dogs. ANIMALS: 13 adult sheep and 11 adult dogs. PROCEDURES: During inhalation anesthesia, for the first 10 minutes following sensor placement, arterial blood gas was analyzed and tcPCO(2) was recorded every 2 minutes. Subsequently, the animals were hyper-, normo-, and hypoventilated. The simultaneously obtained tcPCO(2) and PaCO(2) values were analyzed by use of Bland-Altman statistical analysis. RESULTS: Mean +/- SD overall difference between tcPCO(2) and PaCO(2) 10 minutes after sensor application was 13.3 +/- 8.4 mm Hg in sheep and 8.9 +/- 12 mm Hg in dogs. During hyper-, normo-, and hypoventilation, mean difference (bias) and precision (limits of agreement [bias +/- 2 SD]) between tcPCO(2) and PaCO(2) values were 13.2 +/- 10.4 mm Hg (limits of agreement, -7.1 and 33.5 mm Hg) in sheep and 10.6 +/- 10.5 mm Hg (limits of agreement, -9.9 and 31.2 mm Hg) in dogs, respectively. Changes in PaCO(2) induced by different ventilation settings were detected by the tcPCO(2) sensor with a lag (response) time of 4.9 +/- 3.5 minutes for sheep and 6.2 +/- 3.6 minutes for dogs. CONCLUSIONS AND CLINICAL RELEVANCE: The tcPCO(2) sensor overestimated PaCO(2) in sheep and dogs and followed changes in PaCO(2) with a considerable lag time. The tcPCO(2) sensor might be useful for noninvasive monitoring of changes but cannot be used as a surrogate measure for PaCO(2).     

Biochemical and toxicological differences in the modes of action of the benzoylureas

The two insecticidal benzoylurea compounds, diflubenzuron and chlorfluazuron, show large differences in their toxicity against the larvae of insects like the tobacco budworm, Heliothis virescens, or the Egyptian cotton leafworm, Spodoptera littoralis, chlorfluazuron being about 100 times more toxic. This difference is due mainly to a much faster metabolism of diflubenzuron. Its half-life within the larvae is about 5 h, compared to about 50 h for chlorfluazuron. Chlorfluazuron is also the much better ovicide of the two, following injection of the compounds into the females of H. virescens. Again the difference in the rate of metabolism is the main cause. The rate of excretion of the parent benzoylureas is relatively low, but their metabolites are excreted very quickly.