Putative role of pith cell wall phenylpropanoids in Sesamia nonagrioides (Lepidoptera: Noctuidae) resistance

The stem borer Sesamia nonagrioides (Lefèbvre) is the most important insect pest that attacks maize, Zea mays L., in northwestern Spain. Host plant resistance to this borer was investigated in relation to the cell wall phenylpropanoids content in the pith. Eight inbred lines that differ in resistance were analyzed. Three major simple phenolic acids, p-coumaric, trans-ferulic, and cis-ferulic acids, and three isomers of diferulic acid, 8-5', 8-O-4', and 8-5'b (benzofuran form), were identified. The amount of all these compounds was correlated with the resistance level in the genotypes, with the resistant inbreds having the highest concentrations. The role of these compounds in cell wall fortification and lignification is well-documented, suggesting their possible intervention in S. nonagrioides resistance. Future studies that focus on these compounds could be useful to enhance S. nonagroides resistance.     

Determination of usnic acid in lichen toxic to elk by liquid chromatography with ultraviolet and tandem mass spectrometry detection

Usnic acid is unambiguously confirmed by tandem mass spectrometry (MS/MS) in tumbleweed shield lichen, Xanthoparmelia chlorochroa. The lichen contains 2% usnic acid by liquid chromatography with UV quantification at 282 nm. The UV linear range for usnic acid quantification is from its 4 ng limit of detection to 2 microg injected. UV signal saturation is recognized by distortion of the usnic acid UV spectrum. Positive ion electrospray-tandem mass spectrometry offers no similar means to recognize quantification data recorded above the linear range of electrospray. Electrospray ionization capacity and matrix effects limit the reliability of tandem mass spectrometry quantification. The combination of UV quantification and MS confirmation provides a reliable analytical method for measuring usnic acid levels in plant material.     

Lipolysis during ripening of Emmental cheese considering organization of fat and preferential localization of bacteria

This study followed the progression of lipolysis in Emmental cheese by quantifying the concentrations of individual free fatty acids (FFA) released during ripening in each of the different rooms: 12 days at 12 degrees C, 28 days at 21 degrees C, and 8 days at 4 degrees C. Lipolysis, which corresponded to 1.56% of fat, mainly occurred in the 21 and 4 degrees C rooms, with 68 and 16.5% of total FFA, respectively. The nonselectivity of lipolytic enzymes was evidenced: all fatty acids were released with level of > or =1%. Differential scanning calorimetry experiments showed that the thermal properties of cheese were affected by (i) lipolysis of fat, that is, the monoacylglycerols, diacylglycerols, and FFA that may be localized at the fat/whey interface, and/or by (ii) hydrolysis of high-melting-point triacylglycerols constituted mainly by long-chain saturated fatty acids (e.g., palmitic acid). Analysis of the cheese microstructure was performed using confocal laser scanning microscopy. Fat globules were mainly disrupted after pressing of curd grains, leading to the release of the milk fat globule membrane (MFGM); fat inclusions were surrounded by pockets of whey, delimited by casein strands. Moreover, colonies of bacteria were preferentially localized in situ at the fat/protein interface. This study showed that both the localization of bacteria and the supramolecular organization of fat which was not protected by the MFGM can help the accessibility of milk fat to lipolytic enzymes and then contribute to the quality of cheese.     

Enzymatic O-methylation of flavanols changes lag time, propagation rate, and total oxidation during in vitro model triacylglycerol-rich lipoprotein oxidation

3'-O-Methyl derivatives of flavan-3-ols, (+)-catechin (C), (-)-epicatechin (EC), and (-)-catechin gallate (CG) were prepared enzymatically. Hexanal (EC and CG family, 5 mmol/L) and conjugated diene (C and EC family, 0.25-10 mmol/L) formation following CuSO4-mediated triacylglycerol-rich lipoprotein oxidation was measured. All EC and CG compounds significantly reduced hexanal formation (p < 0.02). O-Methylation improved the ability of CG (more polar) while reducing the ability of EC (less polar) to limit hexanal formation. 3'-O-methyl EC was 18% (p < 0.001) and 4'-O-methyl 65% (p < 0.001) less able than EC to suppress hexanal formation. At >1 micromol/L all EC and C compounds significantly increased lag time. Parent compounds were more effective (> 4-fold increase) than metabolites (1.5-fold increase). Parent compounds did not influence propagation rate (DeltaOD/min). At >1 mmol/L O-methylated EC and C reduced propagation by 20-40% (p < 0.01). Notably, at 0.25 mmol/L O-methylated EC and C increased propagation rates 22% (p < 0.01) despite prolonging lag time.     

Chocolate is a powerful ex vivo and in vivo antioxidant, an antiatherosclerotic agent in an animal model, and a significant contributor to antioxidants in the European and American Diets

Chocolate today is often viewed as a food or snack with little nutritional value. The high saturated fat content of chocolate has also contributed to the belief that its consumption increases the risk of heart disease. However, recent human studies have proven that chocolate has beneficial effects on some pathogenic mechanisms of heart disease such as endothelial function and blood pressure. Although the antioxidant properties of chocolate have been known for some time, there has been no examination of its place in the U.S. diet as a source of antioxidants. This paper demonstrates that chocolate makes a significant contribution to U.S. per capita dietary antioxidants and by inference the European Community's. In the U.S. diet chocolate is the third highest daily per capita antioxidant source. An ex vivo study shows that epicatechin, a major polyphenol in chocolate and chocolate extracts, is a powerful inhibitor of plasma lipid oxidation due to polyphenols' ability to bind to lower density lipoproteins. Conversely, the fat from chocolate alone is a pro-oxidant in this model. This is also demonstrated in an in vivo human study. After consumption of dark chocolate and cocoa powder, the lower density lipoproteins isolated from plasma were protected from oxidation compared to the lipoproteins isolated after cocoa butter consumption, which were put under oxidative stress. In an animal model of atherosclerosis, cocoa powder at a human dose equivalent of two dark chocolate bars per day significantly inhibited atherosclerosis, lowered cholesterol, low-density lipoprotein, and triglycerides, raised high-density lipoprotein, and protected the lower density lipoproteins from oxidation. Chocolate has thus been shown to have potential beneficial effects with respect to heart disease.     

Disease constraints for utilization of the African buffalo (Syncerus caffer) on game ranches in Zambia

Eco-tourism depending on wildlife is becoming increasingly profitable and landowners are beginning to favor game farming and ecotourism. In these areas, large-scale translocation of wildlife involves a diversity of species and large populations. The African buffalo (Syncerus caffer) is one of the major tourist attractions in Zambia. It accounts for 8.7% and 12.4% of the total animal species hunted in the Game Management Areas and the total hunting revenue earned in Zambia, respectively. It is ecologically an important animal species essential for the purpose of habitat control and facilitating the provision of suitable grazing pastures. However, the rearing of the African buffalo on game ranches has been hampered by its carrier state of the Southern Africa Terroritory (SAT) serotypes of foot and mouth disease virus (FMD). The African buffalo is also known to be a carrier of Theileria parva lawrencei, the causative agent of corridor disease (CD) that continues to have devastating effects on the livestock industry in Zambia. In addition, the importation of buffaloes from countries with populations endemic to bovine tuberculosis is highly restricted. Veterinary regulations in Zambia, strongly advocate against the translocation of buffaloes from protected areas to private ranches for disease control purposes thereby mounting a considerable constraint on the economic and ecological viability of the industry. It is hoped that this review will motivate the relevant government authorities in exploiting ways in which this animal species play a central role in eco-tourism.     

Comparison of biopsy samples obtained using standard endoscopic instruments and the harmonic scalpel during laparoscopic and laparoscopic-assisted surgery in normal dogs

Objectives— To compare tissue specimens of canine abdominal organs collected by standard techniques (ST) and harmonic scalpel (HS) and to determine the effect of each technique on wound healing.
Study Design— Experimental.
Animals— Twelve dogs.
Methods— Paired biopsy samples (ST, HS) were collected from liver, spleen, adrenal gland, pancreas, stomach, jejunum, and bladder using laparoscopic or laparoscopic-assisted methods. Hemorrhage at biopsy sites was assessed (present or absent). Specimens were evaluated for diagnostic quality and histologic changes. Dogs were necropsied at 4 or 14 days postoperatively.
Results— HS incision caused less frequent hemorrhage of all organs except spleen. HS specimens had more coagulation necrosis than ST specimens, but both techniques yielded specimens that were sized similarly and were of diagnostic quality. At necropsy, HS biopsy sites of the stomach, jejunum, bladder, adrenal gland, and pancreas were more hyperemic than ST sites. There were more adhesions at jejunal and pancreatic ST biopsy sites. HS biopsy sites had more coagulation necrosis at days 4 and 14 postoperatively. Differences in fibrin deposition, inflammation, and fibrosis were present at biopsy sites of some organs at days 4 or 14 and in comparisons between days 4 and 14.
Conclusions— Diagnostic quality biopsy specimens were obtained with HS and ST. Although HS-induced gross and histologic changes during the first 2 postoperative weeks, no clinical complications were observed.
Clinical Relevance— Both HS and ST can yield specimens with minimal hemorrhage and HS resulted in no apparent postoperative problems in normal dogs. Although HS caused more inflammation and adhesions at biopsy sites of the pancreas, adrenal gland, and jejunum, no clinical complications occurred.     

Radiographic evaluation of the Zurich cementless total hip acetabular component

OBJECTIVE: To radiographically evaluate the Zurich cementless total hip (ZCTH) cup and correlate lucency with clinical signs of implant instability, time since surgery, and implant generation, using zonal analysis. STUDY DESIGN: Retrospective study. ANIMALS: Client-owned dogs (n = 53). METHODS: Radiographs of dogs that had ZCTH arthroplasty (>1 year) were evaluated using zonal analysis, for lucency surrounding the cup-bone interface (number of zones, length, area). Dogs were examined for clinical signs of implant instability (lameness, hip pain). Lucency was correlated with lameness, time after surgery, and implant generation. RESULTS: Radiographs of 68 implants (18 generation I, 50 generation II) were evaluated. Eight dogs were lame (11.8%). Dogs with lameness were more likely to have lucency in > or =2 zones of analysis (per view), have >2 times the average curvilinear length of lucency, and have >4 times the average area of lucency surrounding the implant compared with non-lame dogs. A weak relationship was observed between time after surgery and implant generation; however, there was no relationship between time after surgery and lucency. CONCLUSIONS: Dogs with lameness after ZCTH arthroplasty were more likely to have lucency at the cup-bone interface. Lucency was better evaluated by radiographic projection than zonal analysis. Temporal progression of lucency was weakly correlated with implant generation. CLINICAL RELEVANCE: Dogs with lucency in > or =2 zones of analysis should be evaluated more frequently for clinical signs of implant loosening. Further investigation of serial radiographs after ZCTH arthroplasty is warranted.     

Cloning and radiation hybrid mapping of bovine toll-like receptor-4 (TLR-4) signaling molecules

Toll-like receptor (TLR)-4 is a transmembrane receptor for lipopolysaccharide, a highly pro-inflammatory component of the outer membrane of Gram-negative bacteria. To date, molecules of the TLR-4 signaling pathway have not been well characterized in cattle. The goal of this study was to clone and sequence the full-length coding regions of bovine genes involved in TLR-4 signaling including CASP8, IRAK1, LY96 (MD-2), TICAM2, TIRAP, TOLLIP and TRAF 6 and to position these genes, as well as MyD88 and TICAM1, on the bovine genome using radiation hybrid mapping. Results of this work indicate differences with a previously published bovine sequence for LY96 and a predicted sequence in the GenBank database for TIRAP based on the most recent assembly of the bovine genome. In addition, discrepancies between actual and predicted chromosomal map positions based on the Btau_2.0 genome assembly release were identified, although map positions were consistent with predicted locations based on the current bovine-human comparative map. Alignment of the bovine amino acid sequences with human and murine sequences showed a broad range in conservation, from 52 to 93%. Overall, this work should assist in the assembly and annotation of the bovine genome sequence, the identification of variations in genes critically involved in host innate immunity, and facilitate the study of TLR-4 signaling pathways in cattle.     

Role of lymph-borne cells in the early stages of scrapie agent dissemination from the skin

Scrapie is a natural transmissible spongiform encephalopathy (TSE) of sheep, infecting the animal via the gastrointestinal tract or the skin. This project tested the hypotheses that lymph-borne cells (especially dendritic cells) are crucial for the systemic dissemination of the infectious agent from the site of infection in the skin, that PrP genotype affects PrPSC association with dendritic cells and that PrPSC carriage by cells affects their expression of cytokines. Skin, of scrapie-susceptible VRQ/ARR and scrapie-resistant ARR/ARR PrP genotypes, was scarified with FITC-labelled PrPSC. Pseudoafferent lymphatic cannulation was then used to monitor the presence of FITC-PrPSC over time in different lymph cell populations and plasma in the draining afferent lymphatics. The major observation was that PrPSC did not associate significantly with any lymphocyte or dendritic cell population in the 5 days following PrPSC scarification. The only cells seen to associate with PrPSC were neutrophils. Furthermore, despite the quantity of PrPSC used for scarification being equivalent to a standard infectious dose (the VRQ/ARR sheep dying at approximately 260 days) the only PrP found in afferent lymph during the 0-5-day period was proteinase K sensitive (i.e. soluble PrPC). No differences were observed between the PrP genotypes. Analysis of the effects of PrPSC scarification of cellular cytokine mRNA expression (by a nuclease protection assay) showed raised levels of IL-1beta and IL-8 in the susceptible VRQ/ARR group and raised levels of IFNgamma in the resistant ARR/ARR animals.