A multicentre placebo‐controlled clinical trial on the efficacy of oral ciclosporin A in the treatment of canine idiopathic sebaceous adenitis in comparison with conventional topical treatment

Canine idiopathic sebaceous adenitis (ISA) is an inflammatory reaction of sebaceous glands, potentially resulting in their complete loss. It is considered a T‐cell‐mediated disease, but its precise pathogenesis is still unknown. Topical treatment with oil soaks, humectants and shampoos is effective but laborious. Ciclosporin A (CsA), an immunomodulatory drug, has recently been shown to ameliorate the clinical picture of ISA and to reduce inflammation greatly. It is, however, an expensive treatment option. The objective of this multicentre, partly double‐blinded, randomized controlled study was to evaluate the efficacy of ciclosporin A, either alone or with topical therapy, in comparison to conventional topical treatment alone, as measured by the primary end‐points alopecia and scaling, and multiple histopathological secondary objectives. Thirty‐four dogs with an established diagnosis were treated for 4–6 months and were evaluated before, during and after therapy. Both CsA and topical therapy demonstrated efficacy in this study. Differences between the treatment protocols were marginal. Topical treatment, both alone and in combination with CsA, appeared to reduce scaling more effectively than CsA alone. Both therapies reduced alopecia. There is evidence of a synergistic benefit on both scaling and alopecia, if both treatment options are combined. Inflammation of the sebaceous glands is also best reduced by a combination of both CsA and topical therapy. There is evidence that regeneration of sebaceous glands is best achieved by CsA, either given alone or in combination with topical treatment.     

Method of evaluating diversity of carrot roots using a self-organizing map and image data

Carrot cultivars differ in nutritional value, and the quality of individual pieces may differ from the average, which can be troublesome for companies that process carrots. What is needed is a tool for quick confirmation of the existence and definition of the nature of the differences between the carrot roots. The aim of the experiment was to test whether the simple image parameters, such as colour, will determine the variation within populations of carrot and what kind of information about this differentiation may be provided by a self-organizing map. We indicated that the image data in combination with the self-organization algorithm can provide useful information about carrot roots. However analysis of each individual neural neuron could produce too many summaries to be useful. Therefore, the map was segmented into clusters using k-means method. Segmentation of the self-organizing map allowed to make a comprehensive evaluation of the roots. From the practical point of view such segmentation could help in sorting material, for example, taking into account suitability for processing. The proposed method is sensitive to changes in the processing features of the raw material and is able to locate it in the appropriate area of the topological map. This makes the processor can quickly check whether the raw material he received meets the standards established by a food processing plant. This information is important for the processing industry, in which final product parameters depend on the quality of raw material.     

Molecular mapping of cereal cyst nematode resistance in <Emphasis Type="Italic">Triticum monococcum</Emphasis> L. and its transfer to the genetic background of cultivated wheat

Triticum monococcum, the diploid A genome species, harbours enormous variability for resistance to biotic stresses. A spring type T. monococcum acc. 14087 was found to be resistant to Heterodera avenae (cereal cyst nematode, CCN). A recombinant inbred line population (RIL) developed by crossing this accession with a CCN susceptible T. boeoticum acc. 5088 was used for studying the inheritance and map location of the CCN resistance. Based on composite interval mapping two QTL, one each on chromosome 1AS and 2AS, were detected. The QTL on 1A, designated as Qcre.pau-1A, appeared to be a major gene with 26% contribution to the overall phenotypic variance whereas the QTL on 2A designated as Qcre.pau-2A contributed 13% to total phenotypic variation. Qcre.pau-1A is novel, being the only CCN resistance gene mapped in any ‘A’ genome species and none of the other known genes have been mapped on chromosome 1A. The QTL Qcre.pau-2A might be allelic to Cre5, a CCN resistance gene transferred from Ae. ventricosa and mapped on 2AS. The Qcre.pau-1A was transferred to cultivated wheat using T. durum cv. PBW114 as the bridging species. Selected CCN resistant F₈ lines showed introgression for the molecular markers identified to be linked with CCN resistance locus Qcre.pau-1A. Thus, this gene alone could impart complete resistance against CCN. These introgression lines can be used for marker-assisted transfer of Qcre.pau-1A to elite wheat cultivars.     

Calibrating the leaf colour chart for need based fertilizer nitrogen management in different maize (Zea mays L.) genotypes

Large field to field variability restricts efficient fertilizer N management when broad based blanket recommendations are used in maize (Zea mays L.). To achieve higher yields and to avoid nitrogen (N) deficiency risks, many farmers apply fertilizer N in excess of crop requirement in maize. Field experiments were conducted for five years (2005–2009) to establish and evaluate threshold leaf colour to guide in-season need based fertilizer N topdressings in four maize genotypes. Colour (of the first top maize leaf with fully exposed collar) as measured by comparison with different shades of green colour on a leaf colour chart (LCC) and maize grain yield was significantly correlated. The Cate–Nelson plot of chlorophyll (SPAD) meter/leaf colour chart values against relative grain yield of 0.93 for the experiments conducted during first two years indicated that LCC shade 5 during vegetative growth stages and LCC shade 5.5 at silking stage (R1) can guide crop demand driven N applications in maize. Evaluation of the established threshold leaf greenness during the next three years revealed that fertilizer N management using LCC 5 starting from six-leaf (V6) stage to before R1 stage resulted in improved agronomic and N recovery efficiency in different maize genotypes. There was no response to fertilizer N application at R1 stage. The study revealed that in maize, fertilizer N can be more efficiently managed by applying fertilizer N dose based on leaf colour as measured by LCC than blanket recommendation.     

A miniaturized curcumin method for the determination of boron in solutions and biological samples

Methods for the determination of boron require either sophisticated and expensive equipment (e.g. ICP-OES or ICP-MS) or a relatively large sample volume (e.g. spectrophotometric methods). A modified and miniaturized spectrophotometric curcumin method is presented which allows the determination of boron in sample volumes of 50—150 μl with a detection limit of 0.010 mg B l¹. The calibration curve is linear up to a concentration of 3 mg B l¹. Interferences with other ions are eliminated by extraction of boron with 2-ethyl-1,3-hexanediol in chloroform. Simultaneously, enrichment of boron in the sample can be performed within the same extraction step. Results show good reproducibility with a relative standard deviation of 15% at B concentrations between 0.05 and 0.40 mg B l^—1. In different types of solutions, recovery of added boron was in the range of 98 to 99%. For several plant materials containing from 18 to 58 μg B (g dw)¹, an overall relative standard deviation of 4.5% was established. So far, the method has been successfully applied to determine boron in waters, nutrient solutions, different plant parts (roots, stems and leaves) as well as in phloem sap and apoplastic washing fluid of several plant species.     

Rapid response reactions of roots to boron deprivation

Upon B removal from the nutrient solution, several response reactions of root cells can be measured within minutes. These include: reduction of cell wall elasticity modulus ε, increase of hydraulic conductivity, reduced activity of plasmalemma-bound inducible (NADH) reductase, (smaller) changes of the membrane potential, and liberation of Ca²⁺ (apoplastic and membrane-bound). The B most demanding (root) tissues are epidermal and outer cortical cells of the extension zone, xylem vessels, and root hair tips. Deprivation of B leads to morphological changes which can be noticed within hours to days, including browning of tissues, growth inhibition, death of apical meristems, and lack of root hairs. How the primary response reaction(s) lead to the expression of visible symptoms, however, is not yet clear. The present review summarizes rapid responses to B deprivation and shows several possibilities how primary might be linked to secondary reactions, including cytoskeleton-mediated responses.     

Buchbesprechung

F. Schinner, R. Sonnleitner: Bodenokologie: Mikrobiologie und Bodenenzymatik, Band I: Grundlagen, Klima, Vegetation und Bodentyp. Springer 1996     

Plant UVR8 photoreceptor senses UV-B by tryptophan-mediated disruption of cross-dimer salt bridges

The recently identified plant photoreceptor UVR8 (UV RESISTANCE LOCUS 8) triggers regulatory changes in gene expression in response to ultraviolet-B (UV-B) light through an unknown mechanism. Here, crystallographic and solution structures of the UVR8 homodimer, together with mutagenesis and far-UV circular dichroism spectroscopy, reveal its mechanisms for UV-B perception and signal transduction. β-propeller subunits form a remarkable, tryptophan-dominated, dimer interface stitched together by a complex salt-bridge network. Salt-bridging arginines flank the excitonically coupled cross-dimer tryptophan "pyramid" responsible for UV-B sensing. Photoreception reversibly disrupts salt bridges, triggering dimer dissociation and signal initiation. Mutation of a single tryptophan to phenylalanine retunes the photoreceptor to detect UV-C wavelengths. Our analyses establish how UVR8 functions as a photoreceptor without a prosthetic chromophore to promote plant development and survival in sunlight.     

Abnormal sebaceous gland differentiation in 10 kittens ('sebaceous gland dysplasia') associated with generalized hypotrichosis and scaling

A rare congenital dermatosis, characterized by progressive hypotrichosis with variable scaling and crusting, occurred in 10 short-haired kittens in North America and Europe. Lesions appeared at between 4 and 12 weeks of age, commencing on the head and becoming generalized. The tail was spared in two kittens. Generalized scaling was mild to moderate, often with prominent follicular casts. Periocular, perioral, pinnal and ear canal crusting was occasionally severe. The skin was thick and wrinkled in two kittens. Histologically, the main lesion was abnormal sebaceous gland morphology. Instead of regular differentiation from basal cells to mature sebocytes, the glands were composed of a haphazard collection of undifferentiated basaloid cells, some partly vacuolated and a few containing eosinophilic globules. Mitotic figures and apoptotic cells were present in an irregularly thickened follicular isthmus. Lymphocytic mural folliculitis and mild sebaceous adenitis were rare. Orthokeratotic hyperkeratosis and follicular casts were present. Hair follicles were of normal density and were mostly in anagen, but some contained malacic hair shafts. Perforating folliculitis, leading to dermal trichogranuloma formation, occurred occasionally. Further biopsy samples taken at 2 years and at 3 and 4 years, respectively, from two kittens revealed similar but often more severe sebaceous gland lesions. Hair follicles were smaller, with many in telogen. The young age of onset suggests a genetic defect interfering with sebaceous and, possibly, follicular development. These lesions are discussed with reference to studies of mouse mutants in which genetic defects in sebaceous differentiation cause a similar phenotype of hyperkeratosis and progressive alopecia.