Histochemical distribution of intestinal enzymes of juvenile pacu (Piaractus mesopotamicus) fed lyophilized bovine colostrum

Enzyme activity was evaluated in the intestine of juvenile pacu, Piaractus mesopotamicus, fed diets containing 0, 10 or 20 % of lyophilized bovine colostrum (LBC) inclusion for either 30 or 60 days. The enzymes intestinal acid and alkaline phosphatase (ACP and ALP, respectively), nonspecific esterase (NSE), lipase (LIP), dipeptidyl aminopeptidase IV (DAP IV) and leucine aminopeptidase (LAP) were studied using histochemistry in four intestinal segments (S1, S2, S3 and rectum). Moderate activity of the DAP IV was detected in the three last intestinal segments, but no differences among the treatments were detected. Enzymes LAP, NSE and LIP were weakly stained in all intestinal segments and the inclusion of 10 or 20 % of LBC in the diet commanded a moderate reaction to NSE in the S3 segment at day 60. ACP activity was detected only in the brush border of the S1 segment of fish fed 0 % LBC for either 30 or 60 days. The activity of ALP was very strong in the first intestinal segment, but a weak reaction was seen in the last segments. The inclusion of 20 % of LBC changed the pattern of staining to the ALP, eliciting moderate staining in S2 at day 30 and S1 at day 60. The consumption of diets containing LBC by juvenile pacu did not have significant implications in intestinal enzymatic activity, which still was not fully stimulated.     

Compounds from Ageratum conyzoides: isolation, structural elucidation and insecticidal activity

This work aimed at identifying plant compounds with insecticidal activity against Diaphania hyalinata (L.) (Lepidoptera: Pyralidae), Musca domestica (L.) (Diptera: Muscidae), Periplaneta americana (L.) (Blattodea: Blattidae) and Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae). The plant species used were: basil (Ocimum selloi Benth.), rue (Ruta graveolens L.), lion's ear (Leonotis nepetaefolia L.), Jimson weed (Datura stramonium L.), 'baleeira' herb (Cordia verbenaceae L.), mint (Mentha piperita L.), wild balsam apple (Mormodica charantia L.) and billy goat weed (Ageratum conyzoides L.). Firstly, the insecticidal activities of hexane and ethanol plant extracts were evaluated against adults of R. dominica. Among them, only the hexane extract of A. conyzoides showed insecticidal activity. The hexane extract of this plant species was therefore fractionated by silica gel column chromatography to isolate and purify its bioactive chemical constituents. Three compounds were identified using IR spectra, (1)H NMR, (13)C NMR, HMBC and NOE after gel chromatography: 5,6,7,8,3', 4', 5'-heptamethoxyflavone, 5,6,7,8,3'-pentamethoxy-4', 5'-methylenedioxyflavone and coumarin. The complete assignment of (13)C NMR to 5,6,7,8,3'-pentamethoxy-4', 5'-methylenedioxyflavone was successfully made for the first time. 5,6,7,8,3'-Pentamethoxy-4', 5'-methylenedioxyflavone did not show any insecticidal activity against the four insect species tested. 5,6,7,8,3', 4', 5'-Heptamethoxyflavone showed low activity against D. hyalinata and R. dominica and was not toxic to M. domestica or P. americana. In contrast, coumarin showed insecticidal activity against all four insect pest species tested, with the following order of susceptibility: R. dominica < P. americana < D. hyalinata < M. domestica after 24 h exposure.     

Identification, isolation, and partial characterization of a novel Streptococcus uberis adhesion molecule (SUAM)

The ability to attach to the host cell surface has been considered an important virulence strategy in many bovine mammary gland pathogens, including Streptococcus uberis. Research conducted in our laboratory lead to the identification of an S. uberis adhesion molecule (SUAM) with affinity for bovine lactoferrin (LF) and delineation of its role in adherence of S. uberis to bovine mammary epithelial cells. Using a selected bacterial surface protein extraction protocol and affinity chromatography, a 112-kDa protein that had a similar molecular mass and the LF affinity as one of the identified S. uberis LBP described by Fang and Oliver in 1999 was found. To further characterize SUAM, the N-terminal amino acid sequence of this protein was elucidated. A protein query versus translated database TBLASTN search of the National Center for Biotechnology (NCBI), non-redundant database, nr, with the LBP N-terminal amino acid sequence showed no significant similarity with previous entries. Antibodies directed against SUAM and a 17 amino acid long N-terminal sequence (pep-SUAM) inhibited adherence to and internalization of S. uberis UT888 into bovine mammary epithelial cells. Data presented suggests that we have discovered a novel bacterial protein involved in the pathogenesis of this economically important mastitis pathogen.     

Phosphine-induced walking response of the lesser grain borer (Rhyzopertha dominica)

BACKGROUND: In spite of the intensive worldwide use of phosphine against stored-product insects, its potential sublethal effects on targeted insect species is seldom recognised and may compromise the efficacy of this fumigant, particularly against phosphine-resistant insects. Therefore, the behavioural response of three populations of the lesser grain borer Rhyzopertha dominica (Coleoptera: Bostrichidae) to sublethal phosphine exposure was assessed. RESULTS: Concentration-mortality bioassays with phosphine confirmed the resistance status of the insect populations studied, with levels of phosphine resistance of 40.8-fold and 85.7-fold compared with the susceptible population. Regarding walking behaviour, determined using a digital video-tracking system, the phosphine-resistant populations were less active than the susceptible population. In addition, sublethal phosphine exposure decreased the walking activity of all three populations. CONCLUSION: Phosphine exposure decreased walking ativity. Such reduced walking activity is likely to lower the respiration rate, thereby minimising phosphine uptake. As higher phosphine resistance was also associated with reduced walking activity, phosphine-resistant populations may resist phosphine fumigation even more efficiently on account of this behavioural trait, further aiding their physiological resistance, and should be a matter of concern. Copyright © 2012 Society of Chemical Industry     

Transforming fusions of FGFR and TACC genes in human glioblastoma

The brain tumor glioblastoma multiforme (GBM) is among the most lethal forms of human cancer. Here, we report that a small subset of GBMs (3.1%; 3 of 97 tumors examined) harbors oncogenic chromosomal translocations that fuse in-frame the tyrosine kinase coding domains of fibroblast growth factor receptor (FGFR) genes (FGFR1 or FGFR3) to the transforming acidic coiled-coil (TACC) coding domains of TACC1 or TACC3, respectively. The FGFR-TACC fusion protein displays oncogenic activity when introduced into astrocytes or stereotactically transduced in the mouse brain. The fusion protein, which localizes to mitotic spindle poles, has constitutive kinase activity and induces mitotic and chromosomal segregation defects and triggers aneuploidy. Inhibition of FGFR kinase corrects the aneuploidy, and oral administration of an FGFR inhibitor prolongs survival of mice harboring intracranial FGFR3-TACC3-initiated glioma. FGFR-TACC fusions could potentially identify a subset of GBM patients who would benefit from targeted FGFR kinase inhibition.     

Effect of Conditioning Horses Once,Twice, or Thrice a Week with High-Intensity Intermittent Exercise on v4

Intensive short intervals of exercise are used to condition horses for racing. In this study, the effect of exercising horses one, two, or three times a week during 6 weeks using two intervals with near-maximal speed over 100 m on v₄ (speed at which, under defined conditions, the blood lactate concentration reaches 4 mmol/L) and muscle thickness (MT) of supraspinatus and extensor carpi radialis was examined. Thoroughbreds (4-5 years of age) were exercised twice at near-maximal speed over 100 m, separated by a 10-minute period at walk, on dirt track during conditioning periods (CP) of 6-week duration. This exercise was undertaken once (six horses), twice (six horses), or thrice (five horses) a week during a CP. Before, every 2 weeks during, and 2 weeks after the CP, horses were subjected to a standardized exercise test to determine their v₄. Before and after CP, the MT of the extensor carpi radialis and the supraspinatus was examined by ultrasonography. There was no differential effect of the number of weekly exercises on v₄. Pooling the data of all horses, a decrease of v₄ was found. The decrease became evident after the sixth week of conditioning. MT did not change. The results indicate that the examined exercise protocols could negatively impact racing performance of horses.     

Seroprevalence and risk factors associated with bovine viral diarrhea virus (BVDV) infection in non-vaccinated dairy and dual purpose cattle herds in Ecuador

A cross-sectional study was carried out to determine the seroprevalence and risk factors associated with Bovine viral diarrhea virus (BVDV) infection in non-vaccinated dairy and dual-purpose cattle herds from Ecuador. A total of 2,367 serum samples from 346 herds were collected from June 2008 through February 2009. A questionnaire, which included variables related to cattle, health, management measures, and the environment, was filled out in each herd. A commercial indirect enzyme-linked immunosorbent assay test was used to determine the seropositivity. A logistic regression model was used to determine risk factors at herd level. The individual seroprevalence for BVDV in non-vaccinated herds in Ecuador was 36.2% (857/2,367; CI_95%, 34.3–38.1%). The herd prevalence was 74% (256/346; CI_95%, 69.4–78.6%) and the intra-herd prevalence ranged between 11.1% and 100% (mean = 51.6%). The logistic regression model showed that the density of cattle farms in the area (more than 70%; OR, 1.94; CI_95%, 1.21–3.2) and the altitude (higher than 2,338 m above sea level; 2.33; CI_95%, 1.4–3.9) are potential risk factors associated with BVDV infection.