Identification and characterization of Pyrenophora species causing leaf spot on oat (Avena sativa) in western China

Drechslera leaf spot (DLS) is a serious leaf disease of oats chiefly caused by Pyrenophora chaetomioides in the main oat-producing areas of the world. However, other species of Pyrenophora that may cause DLS have not been investigated in China. From 2018 to 2020, a total of 256 strains of Pyrenophora were isolated from nine oat-producing areas in three provinces in western China. Using a combination of morphological characteristics and phylogenetic analysis of the rDNA internal transcribed spacer (ITS), 28S ribosomal RNA gene (LSU), RNA polymerase second largest subunit region (RPB2), and glyceraldehyde-3-phosphate dehydrogenase region (GAPDH), 66% of the isolates were identified as P. chaetomioides and 34% of isolates belonged to P. avenicola. Pathogenicity tests confirmed that P. avenicola also infected oat and caused DLS, but it was less virulent than P. chaetomioides. From our survey, DLS caused by P. avenicola generally occurred in warm areas at lower altitude and the annual average temperature was above 0°C (Huan and Zhenyuan county in Gansu, Huize county in Yunnan), compared to high-altitude areas (Tianzhu county, Shandan county, Haiyan county). The combination of optimal and maximal temperature indicated that P. avenicola had greater tolerance to high temperature, which was also an important factor for its distribution on oats. Precise identification and understanding of virulence, distribution, and occurrence of these pathogens has significance for control of oat DLS in the future.     

Differential targeting of Gbetagamma-subunit signaling with small molecules

G protein betagamma subunits have potential as a target for therapeutic treatment of a number of diseases. We performed virtual docking of a small-molecule library to a site on Gbetagamma subunits that mediates protein interactions. We hypothesized that differential targeting of this surface could allow for selective modulation of Gbetagamma subunit functions. Several compounds bound to Gbetagamma subunits with affinities from 0.1 to 60 muM and selectively modulated functional Gbetagamma-protein-protein interactions in vitro, chemotactic peptide signaling pathways in HL-60 leukocytes, and opioid receptor-dependent analgesia in vivo. These data demonstrate an approach for modulation of G protein-coupled receptor signaling that may represent an important therapeutic strategy.     

Crusted scabies (sarcoptic mange) in four cats due to Sarcoptes scabiei infestation

Four new cases of sarcoptic mange in cats are described. Two cats resided in areas known to be frequented by foxes, another cohabited with a dog recently diagnosed with sarcoptic mange, while the final cat lived with a mixed breed dog that had been treated for sarcoptic mange 7 months previously. Three cases were diagnosed on the basis of characteristic mite size and morphology in skin scraping from representative lesions, situated on the head (two cases) or head and distal hind limbs (one case). Mites were highly mobile and abundant in all instances, and easily detected also in skin biopsy specimens procured from two cases. Eosinophilic inflammation, hyperkeratosis and parakeratosis were prominent in the tissue sections. In the remaining case, the diagnosis was presumptive, based on characteristic lesions, cohabitation with a canine scabies patient and positive response to scabicide therapy. Pruritus was not a prominent clinical feature in any patient and was considered to be absent in three of the four cases. Lesions in three cats with long-standing disease were reminiscent of crusted scabies (synonym: Norwegian scabies, parakeratotic scabies) as seen in human patients. In three cases, in-contact human carriers developed itchy cutaneous papular lesions. Two cases responded promptly to therapy with systemic avermectin drugs, while one responded to topical treatment with lime sulphur and the remaining cat received both a lime sulphur rinse and ivermectin. Sarcoptic mange should be considered in the differential diagnosis of cats with non-pruritic crusting skin diseases, especially when there is contact with foxes or dogs, and when owners have itchy papular lesions.     

'Wound cat'

'Wound man' refers to a stylised diagram used in early medical textbooks to illustrate the various injuries that the human body can sustain in battle. We have adapted this concept to create 'Wound cat', as a way to emphasise the type and location of injuries cats may inflict on one another during combat. We have further extended this concept to include wounds that may result from interactions with rodents and snakes. It is hoped that our 'Wound cat' concept will assist less experienced clinicians locate sites of cat bites and scratches, and to recognise why certain infections arise in particular stereotyped locations. In addition, this approach should assist veterinarians in determining which pathogens are most likely to be involved in wounds located in a given anatomical region.     

Pharmacokinetic Disposition of Subcutaneously Administered Enrofloxacin in Goats

The pharmacokinetic disposition of enrofloxacin was studied in goats after subcutaneous (s.c.) administration at a single dose of 7.5 mg/kg body weight. Blood samples were drawn from a jugular vein into heparinized tubes at predetermined time intervals after administration of the drug and the plasma was separated by centrifugation. The concentrations of enrofloxacin in the plasma were determined by a microbiological assay using Escherichia coli as the test organism. The plasma concentration–time data were analysed by non-compartmental methods. Enrofloxacin was rapidly absorbed, an appreciable concentration of the drug (0.30±0.13 g/ml) being present in the plasma by 5 min after s.c. administration. The maximum plasma concentration of enrofloxacin and the time to reach that maximum were 2.91±0.39 g/ml and 2.9±0.51 h, respectively. A detectable concentration of enrofloxacin persisted in the plasma for 12 h. The elimination half-life and mean residence time of enrofloxacin were 2.84±0.57 and 5.74±0.28 h, respectively. It is suggested that enrofloxacin given subcutaneously may be useful in the treatment of susceptible bacterial infections in goats.