Deletion analysis of FUM genes involved in tricarballylic ester formation during fumonisin biosynthesis     

Butchko RA  Plattner RD  Proctor RH 《Journal of agricultural and food chemistry》2006,54(25):9398-9404

Fumonisins are carcinogenic mycotoxins produced by the maize ear rot pathogen Gibberella moniliformis (anamorph Fusarium verticillioides). These toxins consist of a linear polyketide-derived backbone substituted at various positions with an amine, one to four hydroxyl, two methyl, and two tricarballylic ester functions. In this study, we generated and characterized deletion mutants of G. moniliformis for five genes, FUM7, FUM10, FUM11, FUM14, and FUM16 in the fumonisin biosynthetic gene cluster. Functional analysis of mutants in four genes, predicted to encode unrelated proteins, affected formation of the tricarballylic esters. FUM7 deletion mutants produced a previously undescribed homologue of fumonisin B1 with an alkene function in both tricarballylic esters, FUM10 and FUM14 deletion mutants produced homologues of fumonisin B3 and fumonisin B4 that lack tricarballylic ester functions, and FUM11 deletion mutants produced fumonisins that lack one of the tricarballylic ester functions. These phenotypes indicated specific roles for FUM7, FUM10, FUM11, and FUM14 in fumonisin biosynthesis that are consistent with the predicted proteins encoded by each gene. Deletion of FUM16 had no apparent effect on fumonisin production. The phenotypes of the deletion mutants provide further insight into the order of steps in fumonisin biosynthesis.  相似文献   

Intraoperative use of ultrasonography during continuous dorsal laminectomy in two dogs with caudal cervical vertebral instability and malformation ("Wobbler syndrome")     

Nanai B  Lyman R  Bichsel P 《Veterinary surgery : VS》2006,35(5):465-469

OBJECTIVE: To describe an intraoperative ultrasound imaging technique during dorsal laminectomy in 2 dogs with caudal cervical vertebral instability and malformation (CCVIM, "Wobbler syndrome"). STUDY DESIGN: Clinical case report. SAMPLE POPULATION: Two dogs with CCVIM. RESULTS: On neurologic examination there was tetraparesis with upper motor neuron signs in the thoracic limbs and lower motor neuron signs in the pelvic limbs in dog 1, and hyperreflexia of the rear limbs, normoreflexia of the right front limb, and hyporeflexia of the left front limb of dog 2. Both dogs had signs of marked cervical pain and radiographic signs of cervical spinal cord compression. Intraoperative ultrasonography of the spinal cord revealed protruding intervertebral disc at C5-6 (dog 1) and C6-7 (dog 2), and the parallel borders of the spinal cord and central canal after decompression. Continuous dorsal laminectomy (CDL) resulted in improvement over 16 months (dog 1) and 20 months (dog 2). CONCLUSIONS: Intraoperative ultrasonographic imaging of the cervical spinal cord after CDL was helpful in determining adequate decompression (postlaminectomy) of the spinal cord in relation to the ventral and lateral compressive component(s) and to image the protruding intervertebral disc. CLINICAL RELEVANCE: Intraoperative ultrasonography can be used to provide valuable information on the spinal cord and surrounding soft tissues for the neurosurgeon.  相似文献   

Overcoming maternal antibody interference by vaccination with human adenovirus 5 recombinant viruses expressing the hemagglutinin and the nucleoprotein of swine influenza virus     

Wesley RD  Lager KM 《Veterinary microbiology》2006,118(1-2):67-75

Sows and gilts lack immunity to human adenovirus 5 (Ad-5) vectored vaccines so immunogens of swine pathogens can be expressed with these vaccines in order to immunize suckling piglets that have interfering, maternally derived antibodies. In this study 7-day-old piglets, that had suckled H3N2 infected gilts, were sham-inoculated with a non-expressing Ad-5 vector or given a primary vaccination with replication-defective Ad-5 viruses expressed the H3 hemagglutinin and the nucleoprotein of swine influenza virus (SIV) subtype H3N2. The hemagglutination inhibition (HI) titer of the sham-inoculated group (n = 12) showed continued antibody decay whereas piglets vaccinated with Ad-5 SIV (n = 23) developed an active immune response by the second week post-vaccination. At 4 weeks-of-age when the HI titer of the sham-inoculated group had decayed to 45, the sham-inoculated group and half of the Ad-5 SIV vaccinated pigs were boosted with a commercial inactivated SIV vaccine. The boosted pigs that had been primed in the presence of maternal interfering antibodies had a strong anamnestic response while sham-inoculated pigs did not respond to the commercial vaccine. Two weeks after the booster vaccination the pigs were challenged with a non-homologous H3N2 virulent SIV. The efficacy of the vaccination protocol was demonstrated by abrogation of clinical signs, by clearance of challenge virus from pulmonary lavage fluids, by markedly reduced virus shedding in nasal secretions, and by the absence of moderate or severe SIV-induced lung lesions. These recombinant Ad-5 SIV vaccines are useful for priming the immune system to override the effects of maternally derived antibodies which interfere with conventional SIV vaccines.  相似文献   

Cryptosporidium, Giardia and Enterocytozoon bieneusi in cats from Bogota (Colombia) and genotyping of isolates     

Santín M  Trout JM  Vecino JA  Dubey JP  Fayer R 《Veterinary parasitology》2006,141(3-4):334-339

The prevalence of Cryptosporidium, Giardia, and Enterocytozoon bieneusi in cats from Bogota (Colombia) was determined from fecal specimens and scrapings of duodenal and ileal mucosa screened by PCR. All PCR-positive specimens were sequenced to determine the genotype(s) present. Of 46 cats, 6 (13%) were positive for Cryptosporidium, 5 (11%) were infected with C. felis and one (2%) with C. muris. Three (6.5%) cats were infected with Giardia duodenalis Assemblage F. Eight (17%) cats were infected with four genotypes of E. bieneusi: genotype D-like (9%), K (4%), Peru 10 (2%), and Peru 5 (2%). This is the first report on the presence of zoonotic species/genotypes of Cryptosporidium and E. bieneusi in cats in Colombia.  相似文献   

Pharmacokinetics of acyclovir after single intravenous and oral administration to adult horses     

Bentz BG  Maxwell LK  Erkert RS  Royer CM  Davis MS  MacAllister CG  Clarke CR 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2006,20(3):589-594

The purpose of the study reported here was to describe the bioavailability and pharmacokinetics of acyclovir after intravenous and oral administration to horses. Six healthy adult horses were used in a randomized cross-over study with a 3 x 3 Latin square design. Three treatments were administered to each horse: 10 mg of injectable acyclovir/kg of body weight in 1 L of normal saline delivered as an infusion over 15 minutes; 10 mg of acyclovir/kg in tablets by nasogastric intubation; and 20 mg of acyclovir/kg in tablets by nasogastric intubation. A 2-week washout period was provided between each treatment. Serum samples were obtained for acyclovir assay using reversed-phase, high-performance liquid chromatography with fluorescence detection. Deproteinated serum was injected onto a C18 column, and elution occurred under isocratic conditions. The limit of quantification was 0.04 microg/mL. The assay exhibited suitable accuracy, precision, and recovery. The IV data were analyzed by a 3-compartment model, and oral data were analyzed noncompartmentally. Intragastric acyclovir administration at either dose was associated with high variability in serum acyclovir-time profiles, low Cmax, and poor bioavailability. The dosage of 20 mg/kg was associated with mean (+/- SD) Cmax of 0.19 +/- 0.10 microg/mL, and bioavailability was 2.8%. Inhibition of equine herpesvirus has been reported to require significantly higher acyclovir concentrations than those obtained here. The results of this study do not support a therapeutic benefit for the oral administration of acyclovir up to doses of 20 mg/kg.  相似文献   

A comparison of extradural and intravenous methadone on intraoperative isoflurane and postoperative analgesia requirements in dogs     

Leibetseder EN  Mosing M  Jones RS 《Veterinary anaesthesia and analgesia》2006,33(2):128-136

Objective To compare the effects of intravenous (IV) and extradural (ED) methadone on end‐tidal isoflurane concentration (Fe ′ISO) and postoperative analgesic requirements in dogs undergoing femoro‐tibial joint surgery. Study Design Randomized, blinded, clinical study. Animals Twenty‐four healthy client‐owned dogs undergoing surgical repair of ruptured cruciate ligaments. Methods Dogs were randomly assigned to two groups of 12 animals and received either ED or IV methadone (0.3 mg kg^?1 diluted with saline to 0.2 mL kg^?1). Pre‐anaesthetic medication was IV acepromazine (0.05 mg kg^?1). Anaesthesia was induced with propofol and maintained initially with an Fe ′ISO of 1.0% delivered in oxygen. Methadone was injected with the dogs in sternal recumbency; the observer was unaware of the administration route. At 10 minutes (stimulation 1) and 20 minutes (stimulation 2) after methadone administration pelvic limb reflexes were tested by digit‐clamping. The time at skin incision (stimulation 3), joint‐capsule incision (stimulation 4), tibial tuberosity drilling (stimulation 5), fabellar suturing (stimulation 6) and extracapsular tightening (stimulation 7) were noted. Changes in heart rate (HR) and respiratory rate and arterial blood pressure associated with surgery were recorded along with the corresponding Fe ′ISO. After 20 minutes of anaesthesia, Fe ′ISO was decreased to the minimum required to maintain stable anaesthesia. Immediately after tracheal extubation, 1, 2, 3 and 6 hours postoperatively and on the morning after surgery, the degree of pain present was assessed using a numerical rating scale. The HR, respiratory rates and blood pressure were also recorded at these times. Serum cortisol and blood glucose concentrations were measured before pre‐anaesthetic medication and at each postoperative pain scoring interval except at 1 and 2 hours. Ketoprofen (2 mg kg^?1), carprofen (4 mg kg^?1) or meloxicam (0.2 mg kg^?1) were given by subcutaneous injection whenever pain scoring indicated moderate discomfort was present. Results Controlled ventilation was required in six dogs which stopped breathing after IV methadone. The median Fe ′ISO at stimulus 5 was 1.0% in the IV and 0.83% in the ED group. At stimulus 6, Fe ′ISO was 1.0% in the IV and 0.8% in the ED group; the difference was statistically significant (p ≤ 0.05). There was no significant difference in the duration of postoperative analgesia associated with administration route. Conclusions Extradural methadone significantly reduces the isoflurane requirement compared with IV methadone during femoro‐tibial joint surgery in dogs. Clinical relevance Extradural methadone provides safe and effective pain relief in dogs undergoing cruciate ligament repair.  相似文献   

Effect of postharvest storage on the expression of the apple allergen Mal d 1     

Sancho AI  Foxall R  Browne T  Dey R  Zuidmeer L  Marzban G  Waldron KW  van Ree R  Hoffmann-Sommergruber K  Laimer M  Mills EN 《Journal of agricultural and food chemistry》2006,54(16):5917-5923

  相似文献   

Cross-modality of texture and aroma perception is independent of orthonasal or retronasal stimulation     

Visschers RW  Jacobs MA  Frasnelli J  Hummel T  Burgering M  Boelrijk AE 《Journal of agricultural and food chemistry》2006,54(15):5509-5515

To assess the influence of orthonasal and retronasal stimulation on cross-modal interactions between texture and flavor perception of food, a series of experiments have been conducted. Healthy human subjects were exposed to strawberry aroma pulses delivered by a computer-controlled stimulator based on air dilution olfactometry. Just prior to exposure to the aroma, the human subjects consumed water, custard, or protein gels with different textures without any added aroma. The aroma was delivered as a sequence of aroma pulses, in either an orthonasal or a retronasal fashion. The retronasal presentation of aroma with concomitant presentation of texture is thought to more closely mimick the in vivo flavor release of semisolid food products as compared to orthonasal stimulation. The time between oral consumption of the food, including swallowing, and the exposure to the aroma varied between 0.5 and 6.5 s. The subjects rated the intensity of the strawberry aroma. It was observed that the intensity of aroma decreased with increasing firmness of the food that was consumed. Aroma pulses delivered 6.5 s after swallowing were perceived as being more intense as compared to aroma pulses delivered immediately after swallowing. In conjunction with late delivery, the effect cross-modal interactions apparently decreased. Significantly higher odor intensities were reported for the aroma stimuli supplied orthonasally in comparison to retronasal administration. The observed cross-modal effect of texture on aroma intensity was not significantly altered by the mode of aroma delivery, i.e., orthonasal or retronasal stimulus administration.  相似文献   

Dimethylsulfoniopropionate uptake by marine phytoplankton     

Vila-Costa M  Simó R  Harada H  Gasol JM  Slezak D  Kiene RP 《Science (New York, N.Y.)》2006,314(5799):652-654

Dimethylsulfoniopropionate (DMSP) accounts for most of the organic sulfur fluxes from primary to secondary producers in marine microbial food webs. Incubations of natural communities and axenic cultures with radio-labeled DMSP showed that dominant phytoplankton groups of the ocean, the unicellular cyanobacteria Prochlorococcus and Synechococcus and diatoms, as well as heterotrophic bacteria take up and assimilate DMSP sulfur, thus diverting a proportion of plankton-produced organic sulfur from emission into the atmosphere.  相似文献   

Pharmacokinetics of intravenously administered caffeine in healthy alpacas (Lama pacos) and llamas (Lama glama)     

Lakritz J  Middleton JR  Anderson DE  Linden DR  Sams RA  Tessman RK  Tyler JW 《American journal of veterinary research》2006,67(6):1063-1069

  相似文献