Absence of three known benzimidazole resistance mutations in Trichostrongylus tenuis, a nematode parasite of avian hosts

Benzimidazole (BZ) resistance is widespread in nematode parasites of livestock, but very little is known about the levels of BZ resistance in parasites with avian hosts. We investigated BZ resistance in Trichostrongylus tenuis, a nematode parasite of red grouse, Lagopus lagopus scotica. BZ anthelmintics had been in use in this system for up to 15 years, yet existing phenotypic evidence for resistance was inconclusive. We screened 1530 individuals from 14 populations at the principal β-tubulin locus for BZ resistance (isotype 1, residue 200) and 940 of these at two further resistance sites (isotype 1, residue 167; isotype 2, residue 200). No BZ resistant genotypes were found. Alternative mechanisms may be responsible for BZ resistance in this system, or the method and timing of treatments may reduce selection pressure for BZ resistance by creating substantial refugia for susceptible genotypes.     

High-throughput assay for detection of soybean lipoxygenase-1

A high-throughput assay was developed to detect soybean lipoxygenase 1 (LOX-1) using a multilabel plate reader. The assay was also adapted to a single cell fluorometer. Fluorescein is degraded by linoleic hydroperoxide produced from soybean lipoxygenase and linoleic acid. The decrease in fluorescence is measured over time, and the area-under-the-curve (AUC) is used to quantify the LOX-1 content of soybean extract. A dose-dependent response is seen with varied dilutions of pure LOX enzyme or soybean extracts. Percent recovery was between 97% and 108%, and relative standard deviation was 4.3%. Advantages of the assay include the reduced preparation time of samples and reduced use of reagents in the high-throughput assay. Multiple samples can be measured in a single run with a multilabel plate reader.     

Effect of photoperiod on hepatic growth hormone receptor 1A expression in steer calves

Photoperiod manipulation, specifically a long-day photoperiod (LDPP), increases milk production in lactating cattle. We have previously reported that the galactopoietic effect of LDPP is associated with an increase in circulating IGF-I, which seems to occur independently of changes in concentrations of GH, IGFBP-2, and IGFBP-3. This study tested the hypothesis that LDPP increases the expression of GH receptor (GHR) 1A messenger RNA (mRNA) in the liver. Two groups of Holstein steer calves (98 +/- 4 d old) were maintained indoors and exposed to LDPP (16-h light: 8-h dark; n = 6) or short-day photoperiod (SDPP; 8-h light: 16-h dark; n = 6) for 60 d. Calves were individually fed a grain- and alfalfa-based diet. Jugular blood samples were collected weekly and via cannula at 15-min intervals for a 4-h period on d 1, 26, and 55 of the study to monitor pulsatile hormone secretion. Serum was harvested and assayed for IGF-I, prolactin (PRL), and GH using RIA. Liver biopsies were obtained at 3-wk intervals to quantify changes in hepatic IGF-I and GHR 1A mRNA using real-time PCR. Steer BW increased during the study but did not differ between treatments. No differences in ADG or total DMI were observed. Relative to SDPP, calves on LDPP had higher (P < 0.05) serum IGF-I concentrations. Concentrations of PRL increased (P < 0.01) in calves exposed to LDPP compared with calves exposed to SDPP. Differences (P < 0.05) in pulsatile GH secretion were also detected. Hepatic IGF-I and GHR 1A mRNA were positively correlated with circulating IGF-I concentrations, and although both increased with time, they were not affected by photoperiod treatment. These results confirm that LDPP increases circulating concentrations of IGF-I, but this occurs independently of changes in IGF-I synthesis and GHR 1A mRNA expression in the liver. Therefore, our hypothesis that LDPP increases the expression of GHR 1A mRNA in the bovine liver is rejected.     

Diagnosis and treatment of presumptive pyelonephritis in an Asian elephant (Elephas maximus).

A 37-yr-old female Asian elephant (Elephas maximus) presented with anorexia, restlessness, and dark-colored urine. Urinalyses showed hematuria, leukocyturia, isosthenuria, proteinuria, granular casts, and no calcium oxalate crystals. Bloodwork revealed azotemia. Urine culture revealed a pure growth of Streptococcus zooepidemicus resistant to sulfamethoxazole-trimethoprim but susceptible to cephalosporins. A presumptive diagnosis of pyelonephritis was made based on bloodwork, urinalysis, and urine culture. The animal was treated with intravenous ceftiofur, and intravenous and per rectum fluids were given for hydration. The elephant's attitude and appetite returned to normal, the abnormal blood parameters resolved, and urinary calcium oxalate crystals reappeared after treatment, supporting presumptive diagnosis. Follow-up ultrasonography revealed an abnormal outline of both kidneys with parenchymal hyperechogenicity and multiple uterine leiomyomas.     

Black soybean promotes the formation of active components with antihepatoma activity in the fermentation product of Agaricus blazei

The antihepatoma activity and related active components in the fermentation products of Agaricus blazei (AB) cultured in the medium containing soybean (S) or black soybean (BS) were investigated. AB(BS)-pE and AB(S)-pE were the ethanolic extracts from the fermentation products of AB(BS) and AB(S), respectively. According to the IC 50 values, AB(BS)-pE (161.1 and 24.0 microg/mL for Hep 3B and Hep G2 cells, respectively) exhibited stronger cytotoxicities against hepatoma cells than AB(S)-pE (>200 and 99.9 microg/mL for Hep 3B and Hep G2 cells, respectively). AB(BS)-pE was separated by silica gel column chromatography and eluted with n-hexane/ethyl acetate/methanol gradient solvent system into 21 fractions. Fraction 3 [AB(BS)-pE-F3], eluted with n-hexane/ethyl acetate (97:3 and 19:1, v/v), was the most active fraction having inhibitory activity on the proliferation of Hep 3B and Hep G2 cells (IC 50 of 3.6 and 1.9 microg/mL, respectively). Three major compounds, compounds 1- 3, were further isolated from the AB(BS)-pE-F3 fraction by reversed-phase semipreparative high-performance liquid chromatography. Compounds 2 and 3 gave better antihepatoma activity than that of compound 1. The IC 50 values of compounds 2 and 3 were 2.8 and 4.5 microg/mL for Hep 3B cells and 1.4 and 2.0 microg/mL for Hep G2 cells, respectively. The structures of compounds 2 and 3 were identified by UV, IR, electron impact mass spectrometry, and (1)H and (13)C NMR to be blazeispirols A and C, respectively. Blazeispirols A and C existed in the mycelia but not in the broth and were more in AB(BS)-pE (49.9 +/- 8.9 and 14.2 +/- 2.4 mg/g, respectively) than AB(S)-pE (15.9 +/- 1.7 and 3.9 +/- 0.6 mg/g, respectively). Additionally, the result shows that the production of blazeispirols A and C was increased after cultivation in the medium containing black soybean on day 6 and reached the maximum on day 12, and the contents of blazeispirols A and C were negatively correlated with Hep 3B and Hep G2 cell viabilities ( r = -0.84 to -0.93, P < 0.01). It suggests that blazeispirols A and C could be used as biomarkers to produce the fermentation product of A. blazei with antihepatoma activity.     

A leakiness index for assessing landscape function using remote sensing

The cover, number, size, shape, spatial arrangement and orientation of vegetation patches are attributes that have been used to indicate how well landscapes function to retain, not ‘leak’, vital system resources such as rainwater and soil. We derived and tested a directional leakiness index (DLI) for this resource retention function. We used simulated landscape maps where resource flows over map surfaces were directional and where landscape patch attributes were known. Although DLI was most strongly related to patch cover, it also logically related to patch number, size, shape, arrangement and orientation. If the direction of resource flow is multi-directional, a variant of DLI, the multi-directional leakiness index (MDLI) can be used. The utility of DLI and MDLI was demonstrated by applying these indices to three Australian savanna landscapes differing in their remotely sensed vegetation patch attributes. These leakiness indices clearly positioned these three landscapes along a function-dysfunction continuum, where dysfunctional landscapes are leaky (poorly retain resources). This revised version was published online in July 2006 with corrections to the Cover Date.     

Prognosis for Neonatal Foals in an Intensive Care Unit

This study was conducted to develop an equation for the prediction of outcome in neonatal foals undergoing treatment in an intensive care unit (ICU). Fifty-three physical examination, historical, and clinicopathologic variables were analyzed from the records of 99 neonatal foals (<14 days of age) treated in the neonatal ICU of the Equine Medical Center. The outcome was recorded and the results were categorized into either surviving or nonsurviving groups. The mean values for the 2 groups were compared, and variables that differed significantly between the two groups were retained and used to construct a logistic regression equation. Retained variables were heart rate, temperature, and neutron phil count. The predictive equation then was tested prospectively in 2 additional groups of foals from 2 separate ICUs. The predicted outcome was compared to the actual outcome, and performance variables were calculated. Sensitivity (.83), specificity (.87), negative predictive value (.72), and positive predictive value (.93) were determined for foals from one neonatal ICU; the sensitivity (.83), specificity (.44), negative predictive value (.44), and positive predictive value (.83) were lower for foals at a second, separate ICU.     

Molecular species of acylglycerols incorporating radiolabeled fatty acids from castor (Ricinus communis L.) microsomal incubations

Sixty-one molecular species of triacylglycerols (TAG) and diacylglycerols produced from castor microsomal incubations incorporating six different (14)C-labeled fatty acids have been identified and quantified. The preference for incorporation into TAG was in the order ricinoleate > oleate > linoleate > linolenate > stearate > palmitate. Ricinoleate was the major fatty acid incorporated, whereas stearate, linolenate, and palmitate were incorporated at low levels. Twenty-one molecular species of acylglycerols (HPLC peaks) in castor oil have also been assigned. The levels of TAG in castor oil are RRR (triricinolein) > RR-TAG > R-TAG > no R-TAG. The levels of the molecular species within the groups of RR-TAG, RL-TAG, and LL-TAG individually are ricinoleate > linoleate > oleate > linolenate, stearate, and palmitate. The results of the labeled fatty acid incorporation are consistent with ricinoleate being preferentially driven into TAG and oleate being converted to ricinoleate in castor oil biosynthesis.     

Suppressive effect of a proanthocyanidin-rich extract from longan (Dimocarpus longan Lour.) flowers on nitric oxide production in LPS-stimulated macrophage cells

Anthocyanidins found in certain flowers have been shown to act as strong antioxidants in various systems, exhibiting multiple biological actions. The antioxidative effects of water extract and ethanolic extract of longan (Dimocarpus longan Lour.) flowers were evaluated by radical scavenging activity and compared to those of gallic acid, myricetin, and epigallocatechin gallate. In this study, the suppressive effects of longan flower extracts on nitric oxide and prostaglandin E2 production were investigated using a lipopolysaccharide-stimulated RAW 264.7 cell model. Abundant levels of phenolic compounds including flavonoids, condensed tannins, and proanthocyanidins were found in water or ethanolic extracts prepared from dried longan flowers. The antioxidative effect of longan flower extract was similar to the effect exhibited by pure antioxidants. Moreover, longan flower extract showed prominent inhibitory effects on prostaglandin E2 production. Significant concentration-dependent inhibition of nitric oxide production was detected when cells were cotreated with lipopolysaccharide and various concentrations of longan flower extracts. These inhibitory effects were further attributed to suppression of inducible nitric oxide synthase protein expression and not to reduced enzymatic activity. These results suggest that longan flower crude extracts, especially ethanolic extract, have antioxidant and anti-inflammatory effects, and the probable mechanism involves inhibition of inflammation by proanthocyanidins. Preliminary observations suggest that longan flower extract, especially alcoholic extract, could be another potential source of natural dietary antioxidant and anti-inflammatory agent.