Uncertainty analysis of a dynamic vapor sorption-fast gas chromatography-flame ionization detection method for the rapid analysis of volatile release from glassy matrices

Uncertainty analysis was conducted with a dynamic vapor sorption-fast gas chromatography-flame ionization detection (DVS-fast GC-FID) method, developed to rapidly analyze the extent of volatile release that occurs from carbohydrate glasses due to humidification and temperature increases. Triplicate samples progressed through a two-step special automatic operation method in the DVS. Samples were exposed to relative humidities ranging from 40 to 90% (in 10% increments) at 15, 25, and 35 degrees C. Uncertainty analysis shows that the DVS-fast GC-FID method uncertainty is smaller than the natural sample uncertainty, indicating that the variability in a sample's physical properties has a dominant impact on the overall uncertainty of the volatile retention results obtained using the DVS-fast GC-FID method. Uncertainty analysis also indicates that the variance associated with the mass of benzaldehyde measured by the DVS-fast GC-FID is the largest contributor to the overall benzaldehyde retention variance when the cumulative mass of benzaldehyde measured is small.     

Relationship between European corn borer resistance and concentration of mycotoxins produced by Fusarium spp. in grains of transgenic Bt maize hybrids, their isogenic counterparts, and commercial varieties

The European corn borer (ECB), Ostrinia nubilalis Hb., is a major pest of maize in central Europe and promotes the infection of maize with Fusarium spp. In this study, transgenic Bt maize hybrids were compared with their isogenic counterparts, and with commercial hybrids from the recommended list with regard to their level of ECB resistance and their concentration of deoxynivalenol (DON), its 15‐acetyl (15‐A‐DON) and 3‐acetyl (3‐A‐DON) derivatives, nivalenol (NIV), fusarenon‐X (FUS‐X), fumonisins (FUM), and zearalenon (ZEN) in harvested grains. The field experiments were performed in Germany at four locations in 1999 and at five locations in 2000. Transgenic Bt hybrids showed significantly lower means than their corresponding isogenic counterparts and than commercial hybrids for all resistance traits: damage rating of stalks, number of larvae per plant, number of larvae per ear, and percentage of damaged plants or ears under infestation. Among all mycotoxins analysed, DON consistently showed the highest concentration across all year × location combinations. Mycotoxin concentrations varied significantly between locations, years and genotypes, whereas mycotoxin concentrations were not significantly different between infested and protected plots. Associations between ECB resistance traits and mycotoxin concentrations were not consistent across years. It is concluded that under central European conditions, the use of Bt maize hybrids will only slightly reduce the contamination of maize kernels with mycotoxins produced by Fusarium spp.     

An ethogram of post-anesthetic recovery behaviors in horses: comparison of pre- and post-anesthetic behaviors

Pain management is an important post-operative concern. Pain scales may rely on the observer's subjective assessment of the level of discomfort and may not correlate with physiologic or pharmacologic measures of pain. The purpose of this study was to develop an objective measure of behavior in healthy pain-free horses recovering from anesthesia that could be used for comparison with the behavior of horses recovering from a surgical procedure.
Focal sampling with videotape and observation was done on five healthy horses before anesthesia to establish baselines. Behavioral measures included head turns, tail swishes, eyelid aperture/size, ear position, angle of neck, weight shifts, and ambulation. Physiologic measures included heart rate, respiratory rate, and temperature. The horses were anesthetized for 2 hours with isoflurane, and in the recovery stall, data were collected continuously on videotape from the time of extubation to standing. Focal sampling of 15 minutes was repeated at 1, 2, 4, and 24 hours after the horses returned to their stalls. Video data were analyzed using the Noldus Observer Video Analysis System.
A wide variation in behavior was observed between horses in the recovery stall. Observations at 1, 2, and 4 hours revealed change from the up/forward ear position to the down ear position, and a decrease in weight bearing of the hind limb from a baseline of 11–12 minutes out of 15 minutes to 7–9 minutes with an increase in toe pointing. Time spent standing was similar to baseline of 93.8%, and the neck angle was not changed from baseline of 173.5°. Values had returned to baseline at 24 hours.
Changes in behavior were induced by anesthesia alone and must be taken into consideration when evaluating analgesic treatments.     

Anticholinergic medication in the dog before and during anesthesia

In clinical studies in dogs of all categories of age, which were predicted for surgical purposes under a combination anaesthesia with Fluanisone/Fentanyl/Nitrous oxide/Halothane, investigations after treatment with atropine or glycopyrrolate were performed. In experimental studies investigations about heart-rate and heart work (rate-pressure-product RPP) under different injection anaesthesia-methods (Fluanisone/Fentanyl/Metomidate, Climazolam/Fentanyl, Xylazine/l-Methadone) are performed. In the clinical studies many of the dogs produce elevated heart-rates after anticholinergic premedication. After special indicated treatment of dysrhythmias with glycopyrrolate or atropine in all cases normorhythmia can be achieved. An increase in heart rate during awaking time can be seen in non premedicated as well as in anticholinergic treated animals for a short period of time. In the experimental studies the anticholinergic treatment leads to increased heart rate and/or elevated arterial pressure, which produce an enormous increase in the rate pressure product and oxygen consumption. In conclusion a general anticholinergic premedication can not be recommended. Its use should be special indicated for bradycardia and/or dysrhythmias in the sense of AV-conduction disturbances.     

Microscopic detection of Leptospira bacterial organisms in urine sediment from a young dog with leptospirosis and a review of the pathobiology and diagnosis of canine leptospirosis

Samples collected from an 11-month-old Dachshund-mix dog with a history of acute azotemia, fever, and enlarged and irregular kidneys were received at the Colorado State Veterinary Diagnostic Laboratory (CSU VDL). The submitting veterinarians were concerned about lymphoma versus acute nephritis/pyelonephritis. The CSU clinical pathology laboratory received urine for urinalysis and kidney aspirates for cytologic evaluation. Urine had also been submitted for aerobic culture and Leptospirosis PCR, and serum was submitted for Lepto-5 microscopic agglutination testing (MAT). Upon examination of a wet mount of the urine sediment, technical staff noted “vibrating” clumps of granular-appearing material throughout the slide, which prompted the preparation of a stained sediment slide for pathologist review. Very small, faintly staining organisms were observed, and an attempt was made to picture-match these with published reports of Leptospira in dog urine, but none could be found. In addition, some references claimed that Leptospira organisms are not seen in urine with light microscopy. The suspicion that these organisms were Leptospira sp. was supported by the MAT results and later confirmed by PCR. The organisms subsequently exhibited strong positive immunolabeling for the Leptospira antigen. This case report provides a searchable record of Leptospira organisms visualized by routine light microscopy in dog urine during natural infection and a review of canine leptospirosis pathobiology and diagnosis.     

Colour Doppler Ultrasonography as a Tool to Assess Luteal Function in Santa Inês Ewes

The aim of this study was to evaluate luteal dynamics in the Santa Inês ewes using colour Doppler (CD) ultrasonography. Oestrus was synchronized in nulliparous females (n = 18), and subsequently, they were only teased (n = 6) or teased and mated (n = 12). Blood samples were collected daily for plasma progesterone (P₄) concentrations. Ultrasonographic images of corpora lutea (CL) in CD mode were obtained for further analysis in its largest diameter. The CD mode allowed an early sequential monitoring of CL that was visualized by the first time 0.77 ± 0.62 days after ovulation, with luteal area 29.68 ± 13.21 mm². During the luteogenesis, a progressive increase was observed, followed by a plateau of luteal area, vascularization area and plasma concentrations of P₄ reaching maximum values in D11 (124.0 ± 38.0 mm², 52.78 ± 24.08 mm² and 11.23 ± 4.89 ng/ml, respectively). In the luteolysis, the plasma concentrations of P₄ decreased sharply, whereas luteal and vascularization area gradually. The vascularization area was positively correlated with plasma concentrations of P₄ during the luteogenesis (r = 0.22) and luteolysis (r = 0.48). The luteal dynamics of Santa Inês ewes showed patterns similar to those observed in other sheep breeds studied. The CD ultrasonography has the potential to be used as a tool to assess luteal function in sheep.     

Anaesthesia with ketamine/medetomidine in the rabbit: influence of route of administration and the effect of combination with butorphanol

Objective To compare the characteristics of anaesthesia induced with ketamine/medetomidine administered by the subcutaneous and intramuscular routes and to assess the effects of the addition of butorphanol to this combination. Study design Prospective randomised study. Animals Six female New Zealand White rabbits. Methods Rabbits were given one of four combinations of ketamine and medetomidine (K/M) either subcutaneously (SC) or intramuscularly (IM) on four successive occasions with a 7‐day interval between treatments. The dose combinations were; 15/0.25 mg kg^?1 SC; 15/0.25 mg kg^?1 IM; 15/0.5 mg kg^?1 SC, and 15/0.25 mg kg^?1 together with 0.4 mg kg^?1 butorphanol (K/M/B) SC. The effects of anaesthesia on arterial blood gas values and cardiovascular variables were recorded at predetermined time points. Toe and ear pinch reflexes were judged to determine the duration of surgical anaesthesia. Loss of the righting reflex was used to measure the duration of sleep time. Analyses used repeated measures analysis of variance. Results All groups lost the righting reflex and ear pinch response. Three animals in the groups that received K/M alone lost their toe pinch reflex, whereas four lost this reflex when given K/M/B. Time of onset of loss of the righting, toe and ear pinch reflexes did not differ significantly among the groups. The higher dose combination of medetomidine with ketamine and the combination of K/M/B produced a greater duration of loss of the ear pinch response than the lower dose of K/M administered by either route. No significant differences were found among the groups in the duration of loss of the toe pinch reflex. All animals developed a moderate bradycardia (mean heart rate <166 beats minute^?1) and moderate hypoxaemia (mean P_aO₂ < 6.0 kPa). Animals given butorphanol showed the greatest reduction in respiratory rate (31 ± 13 breaths minute^?1, p < 0.05) but this was not reflected in any significant differences in arterial PCO₂, PO₂ or pH among the groups. Conclusions Administration of K/M by the SC route produced equivalent effects in comparison to intramuscular administration. The addition of butorphanol increased the duration of anaesthesia, but produced a slight increase in the degree of respiratory depression. All dose rates resulted in hypoxaemia so oxygen should be administered when these combinations are used in rabbits. Clinical relevance Subcutaneous administration is both technically simpler and may cause less discomfort to the animal than IM injection, and so is preferred. The combination of K/M with butorphanol has relatively minor effects on the depth and duration of anaesthesia, so offers little advantage to the use of K/M alone.     

Isolation and molecular characterisation of Neospora caninum in cattle in New Zealand

AIM: To isolate Neospora caninum from the brains of naturally infected cattle and use molecular techniques to characterise the isolates.

METHODS: Neospora caninum tachyzoites were isolated in Vero cell culture from the brains of a cow and two calves. The isolates were characterised using polymerase chain reaction (PCR) methods, DNA sequencing, an immunofluorescent anti-body test (IFAT), transmission electron microscopy (TEM), and immunohistochemistry (IHC). The brains of the three cattle were subjected to histopathological examination. A pathogenicity study was conducted in 120 BALB/c mice.

RESULTS: Neospora caninum tachyzoites were isolated from all three cases and first observed in vitro between 14 and 17 days post-inoculation. Parasites were sub-cultured and maintained in Vero cell culture for more than 6 months. PCR products were generated for all three isolates, using two different primers. Sequencing of the PCR products and a subsequent BLAST search identified the isolates as N. caninum. In addition, the isolates tested positive using IFAT and IHC, and ultrastructure revealed by TEM was characteristic of N. caninum. Histopathological examination revealed lesions characteristic of N. caninum in 1/3 brains. In the pathogenicity study using BALB/c mice, the mortality rate was 3–7%.

CONCLUSION: This was the first successful isolation of N. caninum in New Zealand confirmed using molecular characterisation tests.