In vitro anti‐tubulin effects of mebendazole and fenbendazole on canine glioma cells

Benzimidazole anthelmintics have reported anti‐neoplastic effects both in vitro and in vivo. The purpose of this study was to evaluate the in vitro chemosensitivity of three canine glioma cell lines to mebendazole and fenbendazole. The mean inhibitory concentration (IC₅₀) (±SD) obtained from performing the MTT [3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide] assay after treating J3T, G06‐A, and SDT‐3G cells for 72 h with mebendazole were 0.030 ± 0.003, 0.080 ± 0.015 and 0.030 ± 0.006 μM respectively, while those for fenbendazole were 0.550 ± 0.015, 1.530 ± 0.159 and 0.690 ± 0.095 μM; treatment of primary canine fibroblasts for 72 h at IC₅₀ showed no significant effect. Immunofluorescence studies showed disruption of tubulin after treatment. Mebendazole and fenbendazole are cytotoxic in canine glioma cell lines in vitro and may be good candidates for treatment of canine gliomas. Further in vivo studies are required.     

Concentrations of total glutathione and cysteine in wheat flour as affected by sulfur deficiency and correlation to quality parameters

A method for the simultaneous quantitation of total glutathione and total cysteine in wheat flour by a stable isotope dilution assay using high-performance liquid chromatography/tandem mass spectrometry (HPLC-MS/MS) was developed. As internal standards, L-[(13)C3, (15)N]cysteine and L-gamma-glutamyl-L-[(13)C3, (15)N]cysteinyl-glycine were used. The method consisted of the extraction and reduction of flour with tris(2-carboxyethyl) phosphine after the addition of internal standards, protection of free thiol groups with iodoacetic acid, derivatization of free amino groups with dansyl chloride, and HPLC-MS/MS. The limits of detection and quantitation for glutathione were 0.75 nmol/g and 2.23 nmol/g flour, respectively. For cysteine, the limits of detection and quantitation were 0.72 nmol/g and 2.12 nmol/g flour, respectively. The developed method was found to be sensitive enough for quantitation of total glutathione and cysteine levels in wheat flour. This method was then utilized to investigate the effect of sulfur (S) deficiency on the amount of total glutathione and cysteine in flour. In S-deficient wheat, the concentrations of total glutathione and cysteine were proportional to the amount of S supplied during growth. The calculation of correlations revealed that GSH and Cys concentrations influenced the rheological dough properties and the baking performance at least as much as protein parameters. Thus, the low concentration of GSH and Cys in flour from S-deficient wheat had a similar effect on the technological properties as the altered composition of gluten proteins.     

Epidemic of blindness in kangaroos - evidence of a viral aetiology

OBJECTIVE: To determine the cause of an epidemic of blindness in kangaroos. DESIGN AND PROCEDURES: Laboratory examinations were made of eyes and brains of a large number of kangaroos using serological, virological, histopathological, electron microscopical, immunohistochemical methods, and PCR with cDNA sequencing. In addition, potential insect viral vectors identified during the disease outbreak were examined for specific viral genomic sequences. SAMPLE POPULATION: For histopathological analysis, 55 apparently blind and 18 apparently normal wild kangaroos and wallabies were obtained from New South Wales, Victoria, South Australia, and Western Australia. A total of 437 wild kangaroos and wallabies (including 23 animals with apparent blindness) were examined serologically. RESULTS: Orbiviruses of the Wallal and Warrego serogroups were isolated from kangaroos affected with blindness in a major epidemic in south-eastern Australia in 1994 and 1995 and extending to Western Australia in 1995/96. Histopathological examinations showed severe degeneration and inflammation in the eyes, and mild inflammation in the brains. In affected retinas, Wallal virus antigen was detected by immunohistochemical analysis and orbiviruses were seen in electron microscopy. There was serological variation in the newly isolated Wallal virus from archival Wallal virus that had been isolated in northern Australia. There were also variations of up to 20% in genotype sequence from the reference archival virus. Polymerase chain reactions showed that Wallal virus was present during the epidemic in three species of midges, Culicoides austropalpalis, C dycei and C marksi. Wallal virus nucleic acid was also detected by PCR in a paraffin-embedded retina taken from a blind kangaroo in 1975. CONCLUSION: Wallal virus and perhaps also Warrego virus are the cause of the outbreak of blindness in kangaroos. Other viruses may also be involved, but the evidence in this paper indicates a variant of Wallal virus, an orbivirus transmitted by midges, has the strongest aetiological association, and immunohistochemical analysis implicates it as the most damaging factor in the affected eyes.     

Fractionation of cereal flour by sedimentation in non-aqueous systems. I. Development of the method and chemical characterisation of the fractions

A method for the fractionation of wheat, rye, and barley flours without using aqueous solvents was developed. The separation of protein and starch was based on differences in their densities. Therefore, ball-milled flour was suspended in a mixture of inert solvents (toluene/tetrachoroethene) with a density of 1.47 g/cm³ and centrifuged. Owing to its higher density, the starch fraction was obtained as sediment whereas the protein fraction (PF) formed a layer on the surface of the solvent because of its lower density. The PF was enriched in a solvent mixture with a density of 1.355 g/cm³ yielding a middle fraction (sediment) and the enriched PF (upper layer). The latter was then defatted with toluene (0.87 g/cm) providing a lipid fraction in addition. The influence of ball milling under air or in the sedimentation solvent on the yield and the purity of the fractions was studied. Three varieties of wheat, and one rye and barley variety were fractionated by the optimised method and the obtained fractions were characterised by chemical methods e.g. gel permeation chromatography, SDS electrophoresis, and a combined extraction/HPLC method.     

The Biochemical Basis of Celiac Disease

Celiac disease (CD) is an inflammatory disorder of the upper small intestine triggered by the ingestion of wheat, rye, barley, and possibly oat products. The clinical feature of CD is characterized by a flat intestinal mucosa with the absence of normal villi, resulting in a generalized malabsorption of nutrients. The prevalence of CD among Caucasians is now thought to be in a range of 1:100–300. There is a strong genetic association with human leukocyte antigens (HLA‐)DQ2 and DQ8 and currently unknown non‐HLA genes. During the last decade, intense biochemical studies have contributed to substantial progress in understanding the general principles that determine the pathogenesis of CD. The precipitating factors of toxic cereals are the storage proteins, termed gluten in the field of CD (gliadins and glutenins of wheat, secalins of rye, and hordeins of barley). There is still disagreement about the toxicity of oat avenins. The structural features unique to all CD toxic proteins are sequence domains rich in Gln and Pro. The high Pro content renders these proteins resistant to complete proteolytic digestion by gastrointestinal enzymes. Consequently, large Pro‐ and Gln‐rich peptides are cumulated in the small intestine and reach the subepithelial lymphatic tissue. Depending on the amino acid sequences, these peptides can induce two different immune responses. The rapid innate response is characterized by the secretion of the cytokine interleukin‐15 and the massive increase of intraepithelial lymphocytes. The slower adaptive response includes the binding of gluten peptides (native or partially deamidated by tissue transglutaminase) to HLA‐DQ2 or ‐DQ8 of antigen presenting cells and the subsequent stimulation of T‐cells accompanied by the release of proinflammatory cytokines such as interferon‐γ and the activation of matrix metalloproteinases. Both immune responses result in mucosal destruction and epithelial apoptosis. Additionally, stimulated T‐cells activate B‐cells that produce serum IgA and IgG antibodies against gluten proteins (antigen) and tissue transglutaminase (autoantigen). These antibodies can be used for noninvasive screening tests to diagnose CD. The current essential therapy of CD is a strict lifelong adherence to gluten‐free diet. Dietetic gluten‐free foods produced for CD patients underlie the regulations of the Codex Alimentarius Standard for Gluten‐Free Foods. The “Draft Revised Codex Standard” edited in March 2006 proposes a maximum level of 20 mg of gluten/kg for naturally gluten‐free foods (e.g., based on rice or corn flour) and 200 mg/kg for foods rendered gluten‐free (e.g., wheat starch). Numerous analytical methods for gluten determination have been developed, mostly based on immunochemical assays, mass spectrometry, or polymerase chain reaction. So far, only two enzyme‐linked immunosorbent assays have been successfully ring‐tested and are commercially available. During the last decade, future strategies for prevention and treatment of CD have been proposed. They are based on the removal of toxic epitopes by enzymatic degradation or gene engineering and on blocking parts of the immune system. However, any alternative treatment should have a safety profile competitive with gluten‐free diet.     

Factors affecting nutrient digestibility in rainbow trout (Oncorhynchus mykiss) fed a plant protein–based diet supplemented with microbial phytase

Factors influencing apparent digestibility coefficient (ADC) of nutrients from a plant protein–based diet supplemented with microbial phytase were investigated in a series of experiments with rainbow trout (Oncorhynchus mykiss). The influence of phytase level, water temperature, feed particle size and addition of a protease/non‐starch polysaccharidase (PNSP) enzyme cocktail were tested in a phytase‐supplemented (2000 FTU kg^?1) diet. Finally, the influence of Ca/P ratio, addition of 1,25‐hydroxycholeocalciferol, or inclusion of lactic acid (LA) in diets with and without phytase was evaluated. Addition of microbial phytase improved ADC of dry matter (DM), protein, ash and minerals (P, Ca, Mg, Fe and Zn) (P < 0.05). Reducing feed particle size potentiated the effect of phytase on P and ash ADC, as did the addition of a PNSP enzyme cocktail; the latter also significantly improved DM ADC in both control and phytase‐supplemented diets. Increasing the Ca/P ratio reduced the effect of phytase on P and ash ADC. Addition of 1,25‐dihydroxycholecalciferol and LA had no effect on DM, P and ash ADC in control diets and tended to reduce the phytase‐induced increase in P ADC.     

Use of biofloc technology during the pre‐maturation period of Litopenaeus vannamei males: effect of feeds with different protein levels on the spermatophore and sperm quality

The objectives of this study were: (1) Compare two systems for pre‐maturation of Litopenaeus vannamei in terms of spermatophore and sperm quality, (2) Compare the effect of feeds with different protein levels on reproductive quality of males reared in a biofloc‐dominated system. Animals (36.40 ± 3.13 g) reared under biofloc technology (BFT) were used in the 30‐day experiment, which involved four treatments: one in a clear water system (CW) and other three in a BFT system. The BFT treatments were differentiated by feed: mix of fish, squid and crab (BFT+FF) composed of 68.48% dietary protein (DP); broodstock feed (BFT+BF) composed of 52.51% DP; and juvenile feed (BFT+JF) composed of 39.91% DP. Feed in the CW was also the mix of fresh food. Spermatophore and sperm quality were analyzed at the beginning and end of the experiment. Higher normal sperm rate was recorded in the CW compared with the BFT+FF. Among the BFT treatments, the BFT+FF had the lowest normal sperm rate. Thus, the use of BFT for pre‐maturation of L. vannamei allowed the reduction in dietary protein levels from 68.48% (BFT+FF) to 39.91% (BFT+JF) and the maintenance of spermatophore and sperm quality compared to the system based on high daily exchange rate.     

Genetic correlations between lean growth and litter traits in U.S. Yorkshire,Duroc, Hampshire,and Landrace pigs

The objective of this study was to estimate breed-specific genetic correlations between lean growth and litter traits for four U.S. swine breeds. Records for lean growth and litter traits on Yorkshire, Duroc, Hampshire, and Landrace pigs collected between 1990 and April 2000 in herds on the National Swine Registry Swine Testing and Genetic Evaluation System were analyzed. A bivariate animal model and restricted maximum likelihood procedures were used to estimate genetic and environmental correlations between lean growth rate, days to 113.5 kg, backfat, and loin muscle area with litter traits of number born alive, litter weight at 21 d, and number weaned. Most genetic correlation estimates between lean growth and litter traits were small in magnitude and consistent across breeds. Backfat had the largest within-breed genetic correlations with number born alive (0.18 to 0.20) and litter weight at 21 d (-0.27 to -0.30). Estimates of genetic correlations between lean growth traits and number weaned were very small. Estimates of the environmental correlations between lean growth and litter traits also were very small for all traits and for all four breeds. Results indicate that selection for lean growth traits could have a long-term effect on litter traits. Including lean growth traits in a maternal-line evaluation using a multiple-trait model could increase the accuracy of the genetic evaluation for litter traits.     

无芒雀麦引种适应性的观察

无芒雀麦是多年生根茎型丛生性禾本科牧草,在青海省贵南县海拔3400m的地区引种栽培,其结果表明:播种当年出苗整齐,第二年越冬良好,越冬率为91％;第二年、第三年的鲜草产量分别为10436.61kg/hm2、14100kg/hm2,其茎叶比分别为1.4:1、2.17:1,种子产量为87k/hm2,可以在贵南县进行大面积的推广种植,在无芒雀麦的开花盛期适时利用。