Prevalence and importance of internal tandem duplications in exons 11 and 12 of c-kit in mast cell tumors of dogs

OBJECTIVE: To determine the prevalence of activating internal tandem duplications (ITDs) in exons 11 and 12 of c-kit in mast cell tumors (MCTs) of dogs and to correlate these mutations with prognosis. SAMPLE POPULATION: 157 formalin-fixed, paraffin-embedded MCTs from dogs in the pathology database of the Veterinary Medical Teaching Hospital at the University of California, Davis. PROCEDURE: Genomic DNA was isolated from tumor specimens and a polymerase chain reaction procedure was performed to determine whether there were ITDs in exons 11 and 12. RESULTS: We identified ITDs in 1 of 12 (8%) grade-I, 42 of 119 (35%) grade-lI, and 9 of 26 (35%) grade-ll tumors (overall prevalence, 52 of 157 [33%]). Logistic regression analysis revealed that the odds of grade-II and -III tumors possessing an ITD were approximately 5 times greater than that for grade-I tumors, although these odds did not differ significantly. Although MCTs possessing an ITD were twice as likely to recur after excision and twice as likely to result in metastasis as those without an ITD, these values also did not differ significantly. CONCLUSIONS AND CLINICAL RELEVANCE: These results provide evidence that ITDs in c-kit occur frequently in MCTs of dogs. The high prevalence of c-kit activating mutations in MCTs of dogs combined with the relative abundance of mast cell disease in dogs provide an ideal naturally developing tumor in which to test the safety and efficacy of novel small-molecule kinase inhibitors such as imatinib mesylate.     

Asset Management for Irrigation and Drainage Infrastructure – Principles and Case Study

This paper presents the general principles and functions of asset management for irrigation and drainage infrastructure: Asset planning and creation strategies, operation and maintenance, performance monitoring, accounting and economics and audit and renewal analysis. The various elements of the program are conceptually defined and their application is illustrated with the asset management program (AMP) formulated for the La Khe Irrigation System in Vietnam. It also identifies the role of the AMP within the framework of service oriented management of irrigation and drainage services. An infrastructure and investment profile developed from the asset survey identified the investment requirement over the next 40 years. The analysis of cost of service and revenues shows a shortfall of US£17.00/ha/annum to meet the investment requirement over this period. The asset audit and renewal analysis shows the upgrades of the main system needed to improve the current level of service.     

Use of kit internal tandem duplications to establish mast cell tumor clonality in 2 dogs

Mast cell tumor (MCT) is one of the most common tumors of dogs. Some affected dogs develop multiple cutaneous tumors in various locations over months to years. In these cases, it is not clear whether the tumors have arisen de novo, or if each tumor represents a recurrence of the previously excised original tumor (ie, distant metastasis). We used the presence of an internal tandem duplication (ITD) in c-kit to demonstrate that in 2 dogs with recurrent cutaneous MCT that had developed over 1-2 years, each recurrent MCT tumor possessed an identical ITD when compared to the original MCT, indicating that the multiple tumors were clonal in origin. This study demonstrates that similar to the situation in humans, specific somatic mutations identified in oncogenes found in canine neoplasms can be used to provide evidence of tumor clonality.     

Ammonia reduction in seawater by Yucca schidigera extract: efficacy analysis and empirical modelling

Yucca schidigera is a plant native to southwestern USA and Mexico. Its extract has been used in the livestock industry to control ammonia accumulation in animal holding facilities, and to reduce ammonia concentration in animal excreta. This study investigated the potential and effectiveness of Y. schidigera extract (YUPE) for ammonia reduction in seawater. A dose–response experiment was conducted to determine the effect of different concentrations of YUPE at 0, 18, 36, 72 and 108 mg L⁻¹ on total ammonia nitrogen (TAN) at 1, 3 and 9 mg L⁻¹. At a higher YUPE dosage rate, higher TAN reduction was observed, and TAN reduction was highest during the first 12 h, and decreased thereafter. A stepwise multiple linear regression that included the initial TAN, YUPE concentration and time was developed, which accurately predicted empirical TAN concentrations. Applications of this model for ammonia management strategies were formulated for hypothetical tiger prawn (Penaeus monodon) rearing conditions. YUPE's efficacy for ammonia reduction, natural origin and safety make YUPE a potentially suitable compound for water quality management in mariculture.     

Genetic structures of Calophyllum inophyllum L., a tree employing sea-drift seed dispersal in the northern extreme of its distribution

? Context

Little is known about the potential of gene flow and resulting genetic structures of trees employing sea-drifting seed dispersal in island populations.

? Aims

Current genetic structure and the magnitude of historical gene flow were estimated in island populations of Calophyllum inophyllum L., a typical plant employing sea-drifting seed dispersal.

? Methods

Samples were collected from the northern extreme of the species’ distribution (Taiwan and the Sakishima, Daito, and Ogasawara Islands, Japan) and genotyped using 15 EST-SSR markers. Genetic differentiation (F _ST and AMOVA), genetic structure (STRUCTRE analysis), and historical gene flow (assignment testing) were determined.

? Results

Frequent gene flow within and rare gene flow among island groups was determined using assignment testing. Clear genetic structures were also detected using the STRUCTURE analysis, which demonstrated differentiation between dominant clusters among geographically constructed island groups.

? Conclusions

The potential for gene flow via sea-drifting seed dispersal was high, and this was possible even among small islands. However, the extent and frequency of gene flow were not great enough to prevent genetic differentiation in a range of over a few hundred kilometers.     

Recognition of self antigens by skin-derived T cells with invariant gamma delta antigen receptors

Thy-1+ dendritic epidermal T cells (dECs) express invariant gamma delta antigen receptors and are found in intimate contact with keratinocytes in murine epidermis--thus raising the possibility that keratinocytes express a ligand for the antigen receptor of these T cells. Thy-1+ dECs were stimulated to produce lymphokines by interaction with keratinocytes in vitro. This stimulation was mediated through the dEC antigen receptor and did not appear to be restricted by the major histocompatibility complex. Thus, dECs can recognize self antigens and may participate in immune surveillance for cellular damage rather than for foreign antigens.     

Characterization of grape procyanidins using high-performance liquid Chromatography/Mass spectrometry and matrix-assisted laser Desorption/Ionization time-of-flight mass spectrometry

High-performance liquid chromatography/mass spectrometry (HPLC/MS) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) were used to characterize the procyanidin composition of the grape seed extract. The detection of the oligomers composed of (+)-catechin, (-)-epicatechin, and their galloylated derivatives in the grape seeds is demonstrated. With MALDI-TOF MS, oligomers up to nonamers were observed. The potential of the MALDI-TOF MS technique as a quantification tool is also discussed. The information presented in this study could lead to the determination of procyanidin content and their molecular weight distribution in grape seeds.     

Effect of high-oxygen atmospheres on blueberry phenolics, anthocyanins, and antioxidant capacity

The influence of high oxygen concentrations on total phenolic, total anthocyanin, individual phenolic compounds, and antioxidant capacity (measured as oxygen radical absorbance capacity, ORAC) in highbush blueberry fruit (Vaccinium corymbosum L. cv. Duke) was investigated. Freshly harvested blueberries were placed in jars ventilated continuously with air or with 40, 60, 80, or 100% O(2) at 5 degrees C for up to 35 days. Samples were taken initially and at 7-day intervals during storage. Whereas the quality parameters of titratable acidity, total soluble solids, and surface color were only slightly affected by the superatmospheric O(2) treatments, the antioxidant levels were markedly increased by 60-100% O(2) treatments as compared with 40% O(2) treatment or air control during 35 days of storage. Elevated O(2) between 60 and 100% also promoted increases of total phenolics and total anthocyanins as well as the individual phenolic compounds analyzed by HPLC. Fruit treated with O(2) concentrations of >/=60% also exhibited significantly less decay. Data obtained in this study suggest that high-oxygen treatments may improve the antioxidant capacity of blueberry fruit. Furthermore, antioxidant capacity may be correlated with total phenolic and anthocyanin contents in blueberries.     

Development of a molecular marker for a bruchid (Callosobruchus chinensis L.) resistance gene in mungbean

Bruchid, Callosobruchus spp. (Coleoptera: Bruchidae), is a serious pest during storage of seeds of mungbean (Vigna radiata (L.) Wilczek) and other Vigna species. A source of resistance to this pest has been identified in Vigna sublobata (Roxb.) Bairig. accession TC1966. Two hundred recombinant inbred lines at the F₁₂ generation have been developed for molecular mapping of bruchid resistance (Br) gene in TC1966. Through bulked segregant analysis (BSA), ten randomly amplified polymorphic DNA (RAPD) markers associated with the bruchid resistance gene were successfully identified. A total of four closely linked RAPDs were cloned and transformed into sequence characterized amplified region (SCAR) and cleaved amplified polymorphism (CAP) markers. Seven CAPs developed from the identified RAPD markers showed tighter linkage with the Br gene than the original RAPD. Through transformation of RAPDs into CAPs, codominant markers for bruchid resistance were successfully obtained. Homozygous genotypes of these PCR-based markers were estimated to contribute 85% of the variance for seed damage when the insect assay was performed under favorable growth conditions for bruchid.     

Engulfed pathogen-induced apoptosis in haemocytes of giant freshwater prawn, Macrobrachium rosenbergii

Haemocytes of the giant freshwater prawn, Macrobrachium rosenbergii, were investigated for the induction of apoptosis after phagocytosis of pathogenic yeasts, bacteria and non-pathogenic latex beads in vitro. Isolated haemocytes of M. rosenbergii were cultured at a ratio of 1:50 haemocytes to pathogen with the yeast Debaryomyces hansenii, the bacteria Aeromonas hydrophila or Enterococcus faecium, or with latex beads at 25 degrees C for 2 h, followed by washing to remove free particles. At least 200 haemocytes were counted to determine the phagocytosis rate, and the results showed that haemocytes engulfed latex beads at a higher rate than the aquatic pathogens. By transmission electron microscopy, the yeast- or bacterium-engulfing haemocytes displayed morphological changes characteristic of apoptosis, including formation of cytoplasmic vacuoles, chromatin condensation and fragmentation of nuclei. This pathogen-induced apoptosis was further confirmed by DNA laddering and TUNEL (terminal deoxynucleotidyl transferase-mediated deoxy-UTP nick-end-labelling) assays. Neither haemocytes treated with latex beads nor uninfected haemocytes (control group) showed signs of apoptosis after 48 h in culture.