Isotope-edited nuclear magnetic resonance: novel methodologies for investigating metabolism

While the use of NMR and stable isotopes in metabolism studies is hardly new, it is only recently that isotope-edited NMR spectroscopy has been applied in kinetic studies of glyphosate metabolism of soil microbes. NMR can detect multiple species simultaneously and non-destructively, yielding valuable information on structural identification of metabolites. T riple R esonance I sotope ED ited spectroscopy (TRIED), [²H]NMR, and [²H–¹³C] INEPT (I nsensitive N ucleus E nhancement through P olarization T ransfer) are three isotope-edited techniques which have been used in combination to examine the microbial degradation of glyphosate (N-phosphonomethylglycine). Using ¹³C- and ¹⁵N-labeled glyphosate, TRIED can detect multiple metabolites in crude matrices at submicrogram levels, an improvement over earlier techniques where milligrams were needed. It can detect 500 nanograms of ¹³C–¹⁵N-labeled compound in a crude sample (1 : 1400 mass ratio), only a few hours work being required. [²H]NMR and [²H–¹³C]INEPT were also used as complementary techniques to further examine metabolites whose ¹³C–¹⁵N bond has been cleaved. The three-isotope-edited methods produced results consistent with both radioactivity and HPLC analyses. Accordingly, we are able to detect minute levels of metabolites in the presence of complex mixtures, minimizing the costs and time of sample purification. ©1999 Society of Chemical Industry     

Effects of Temperature on Feeding Activity of the White River Crayfish Procambarus acutus acutus1

Feed consumption by white river crayfish Procambarus acutus acutus in a 56-d laboratory study increased at a linear rate with water temperature over a range of 5 to 25 C. Feed consumption changed as water temperatures were cycled from 20–8–20 C (0.5 C/d) over a 68-d period and was the highest at the initial 20 C level and the lowest at 8 C. As water temperature increased, feed consumption rate increased; however, consumption never reached the initial rate at 20 C. Crayfish fed 3% and 6% of body weight were significantly larger than animals fed at 1% of body weight after 8 wk. Feed conversion ratios increased significantly with feeding rate. Based on this laboratory study, white river crayfish feed most effectively when water temperature is ≥ 15 C and the feeding rate is 3% of body weight/d.     

The Kinetics of Spinning-Disc Atomizers Applied to Seed Treatment Machinery1

Spinning disc-atomizers are widely used in seed-dressing machines. They not only give an initial velocity to the droplet but deliver air as well, consequently the droplet enters a moving medium. Computer analysis shows the influence of this mutual motion in the case of linear, parabolic and hyperbolic air velocity decrease. The moving air exerts a significant effect on the ideal encounter zone of liquid and seed. This effect should be taken into consideration in designing the dressing chamber of seed treatment machinery.     

Comparative Earth History and Late Permian Mass Extinction

The repeated association during the late Neoproterozoic Era of large carbon-isotopic excursions, continental glaciation, and stratigraphically anomalous carbonate precipitation provides a framework for interpreting the reprise of these conditions on the Late Permian Earth. A paleoceanographic model that was developed to explain these stratigraphically linked phenomena suggests that the overturn of anoxic deep oceans during the Late Permian introduced high concentrations of carbon dioxide into surficial environments. The predicted physiological and climatic consequences for marine and terrestrial organisms are in good accord with the observed timing and selectivity of Late Permian mass extinction.     

The importance of habitat resistance for movement decisions in the common lizard, Lacerta vivipara

ABSTRACT: BACKGROUND: Movement behaviour can be influenced by a multitude of biotic and abiotic factors. Here, we investigate the speed of movement in relation to environmental and individual phenotypic properties in subadult common lizards (Lacerta vivipara). We aim to disentangle the importance of substrate, cover, humidity, basking opportunity and individual phenotype on moving tendencies in 12 treatment combinations, at which each lizard was tested. RESULTS: We find that movement behaviour depends on the starting conditions, the physical properties of the dispersal corridor, and on the individuals' phenotype. Specifically, the presence of cover and substrate providing suitable traction in the corridor had positive effects on individual movement decisions. Additionally, we find high phenotypic variation in the propensity to move dependent on the presence of cover. Individual back patterns also strongly affected movement decisions in interaction with the physical properties of the dispersal corridor. CONCLUSIONS: Our results highlight the importance of understanding the habitat resistance for movement patterns, with humid habitats with covering vegetation providing the best conditions to initiate movement in the common lizard. In addition, population effects, differences in back pattern phenotype and individual plasticity were identified as key parameters influencing movement behaviour.     

The Current State of Solar Modeling

Data from the Global Oscillation Network Group (GONG) project and other helioseismic experiments provide a test for models of stellar interiors and for the thermodynamic and radiative properties, on which the models depend, of matter under the extreme conditions found in the sun. Current models are in agreement with the helioseismic inferences, which suggests, for example, that the disagreement between the predicted and observed fluxes of neutrinos from the sun is not caused by errors in the models. However, the GONG data reveal subtle errors in the models, such as an excess in sound speed just beneath the convection zone. These discrepancies indicate effects that have so far not been correctly accounted for; for example, it is plausible that the sound-speed differences reflect weak mixing in stellar interiors, of potential importance to the overall evolution of stars and ultimately to estimates of the age of the galaxy based on stellar evolution calculations.     

Biochemical analysis of uterine fluid for identification of indicators for subclinical endometritis in the water buffalo (Bubalus bubalis)

Alterations in biochemical constituents of uterine fluid have been suggested for diagnosis of subclinical uterine infection in the bovine. This study was undertaken to investigate whether uterine fluid biomolecules could act as tool for diagnosis of subclinical endometritis in the buffalo. Uterine fluid samples from normal (n = 22) and subclinical endometritis (n = 18; diagnosed based on uterine cytology)‐affected buffaloes were subjected to biochemical analysis. Among the different biochemical constituents estimated, urea, urea N, cholesterol, total bilirubin and alkaline phosphatase (ALP) concentrations were significantly (p < 0.05) higher in uterine fluid obtained from subclinical endometritis‐affected buffaloes. The extent of difference between normal and subclinical endometritis‐affected buffaloes was highest in ALP (69%) followed by cholesterol (55%), bilirubin (48%), urea (30%) and urea N (30%) concentrations. Receiver operating characteristic (ROC) analysis indicated that the likelihood ratio (LR) was 3.63 for urea, indicating that buffaloes having less than the threshold concentration (47.5 mg/dl) of urea in their uterine fluid were at 3.6 times more risk to be affected with SE. The LRs for urea N, cholesterol, ALP and bilirubin were 2.33, 2.54, 2.12 and 1.65, respectively. It was concluded that ALP, urea, urea N and cholesterol concentrations in uterine fluid may serve as an aid for diagnosing subclinical endometritis in the buffalo.     

Canine histiocytic ulcerative colitis

Objective To assess prevalence, breed predilection, response to therapy and prognosis of canine histiocytic ulcerative colitis (CHUC).
Design A retrospective study of cases of CHUC seen at Sydney University Veterinary Teaching Hospital (SUVTH) over a 20-year period (1975 -1994).
Procedure Case records of all dogs in which colitis was suspected were reviewed. Dogs were diagnosed with CHUC based on colonorectal biopsy and histopathological examination.
Results CHUC was diagnosed in 8 of 57 dogs presented for colitis. All affected dogs were Boxers and six were female. Dogs with milder clinical signs showed moderately good response to therapy. Four dogs were still alive 1 to 7 years after diagnosis. Three dogs were euthanased, one for reasons other than CHUC, and one was lost to follow-up.
Conclusions Young boxer dogs with relatively mild signs of CHUC may respond moderately well to medical and dietary therapy with fair prognosis. Euthanasia early in the course of the disease may be unwarranted. Prevalence may be increasing within the SUVTH referral population.     

Ovsynch Plus protocol improves ovarian response in anovular Murrah buffaloes in low‐breeding season

The objective of the study was to evaluate the efficacy of ovarian response and pregnancy rate in anovular buffaloes following Ovsynch and Ovsynch Plus protocols. Buffaloes (n = 55) were divided into two groups: Ovsynch group (n = 26): GnRH (10 μg, GnRH1) on Day 0, PGF₂α (25 mg) on Day 7, GnRH (10 μg, GnRH2) on Day 9; Ovsynch Plus group (n = 29): 500 IU equine chorionic gonadotropin (eCG) 72 hr (day ?3) prior to Ovsynch protocol, followed by fixed timed artificial insemination (FTAI) 6 and 24 hr after GnRH2 injection in bot groups. Transrectal ultrasonography was performed daily, that is, from day 0 and ?3 in Ovsynch and Ovsynch Plus group, respectively for ovarian response and pregnancy diagnosis at day 30 post‐insemination. In Ovsynch Plus group, administration of eCG prior to GnRH1 increased (p < .001) the diameter (mm) of dominant follicle (DF) from 10.15 ± 0.26 to 12.23 ± 0.34 within 72 hr of treatment resulting higher ovulatory response to GnRH1. Ovulation after GnRH1 was higher (p < .01) in Ovsynch Plus group (96.6%) than Ovsynch group (61.5%). However, ovulation rate to GnRH2 was similar (p > .05) between groups (Ovsynch group: 76.9% vs. Ovsynch Plus group: 70.0%). Mean DF diameter (mm) that ovulated to both GnRHs was higher (p < .01) than non‐ovulated counterparts in both groups (Ovsynch group: 10.80 ± 0.27 vs. 8.47 ± 0.53; Ovsynch Plus group: 11.99 ± 0.24 vs. 9.5 ± 0.63). Pregnancy was established in buffaloes which responded to both GnRHs, irrespective of groups, being higher (p = .52) in Ovsynch Plus group (34.5%) than Ovsynch group (23.1%), though non‐significant. In summary, this study showed that eCG inclusion prior to Ovsynch regimen improves ovulatory response in anovular buffaloes during low‐breeding season.     

Experience and confidence of final year veterinary students in performing desexing surgeries

AIMS: To describe the level of experience and confidence of veterinary students in performing canine and feline desexing procedures at the end of their final clinical year.

METHOD: A cross-sectional survey was conducted with veterinary students at Massey University in November 2017 after completion of their final clinical year. The questions included career plans after graduation, number of assisted and unassisted desexing procedures performed, approximate time to complete desexing surgeries, level of confidence with different aspects of desexing surgeries, what aspects of their desexing surgery training were most helpful, and what could be done to improve training in desexing surgical skills in veterinary school.

RESULTS: The survey was completed by 70/95 (74%) students in their final clinical year. Among respondents, 55/70 (70%) had performed >2 unassisted feline neuters before graduation. However 38/70 (54%) students had never performed an unassisted feline spay, 31/70 (44%) had never performed an unassisted canine neuter, and 44/70 (63%) students had never performed an unassisted canine spay. The median reported times to complete a feline neuter, feline spay, canine neuter, and canine spay were 9, 40, 30 and 60 minutes, respectively. The median level of confidence for these procedures were 9, 6, 7 and 5 (on a scale from 1=least confident to 10=most confident), respectively. The reported time to complete procedures and the confidence in performing procedures did not change markedly with increasing total number of procedures performed. Students were most concerned about their ability to perform the desexing procedures in a reasonable amount of time and to prevent post-operative bleeding from occurring. Students were least concerned with their ability to manage post-operative pain in patients and to select the appropriate suture material. Free-text comments revealed that 62/70 (89%) students wanted more hands-on surgical experience prior to graduation.

CONCLUSION AND CLINICAL RELEVENCE: Many students are currently completing veterinary school with limited experience and low confidence with performing routine canine and feline desexing procedures. Further research is needed to identify the most effective ways for addressing this issue within the constraints of the veterinary curriculum and teaching hospital resources.