Postoperative pain and perioperative analgesic administration in dogs: practices, attitudes and beliefs of Queensland veterinarians.

OBJECTIVE: The aim of this study was to describe the practices, attitudes and beliefs of Queensland veterinarians in relation to postoperative pain and perioperative analgesia in dogs. METHODS: One veterinarian from each of the 50 randomly selected Queensland veterinary practices was enrolled after selection by convenience sampling. RESULTS: The study response rate was 94.3%. Demeanour, vocalisation and heart rate were the most common postoperative pain assessment tools used, even though the most sensitive tools were considered to be demeanour, heart rate and respiratory rate. Only 20% of respondents used formalised pain scoring systems. Preoperative analgesic administration was always used by 72% of respondents. There was marked variability in the frequency with which analgesia was administered perioperatively for ovariohysterectomy. Only 24% of veterinarians discharged animals with ongoing analgesia even though 38% agreed that pain is still present 7 days postoperatively. Multimodal analgesia was used by 82% of respondents. Epidural and local anaesthetic analgesic techniques were not being utilised by any respondents. Conclusions These results indicate that management of postoperative pain in dogs in Queensland is frequently suboptimal and, at times, is not consistent with the veterinarian's attitudes and beliefs. Continuing education into analgesic use and pain evaluation may be effective in addressing this.

Augmented Topological Descriptors of Pore Networks for Material Science.

One potential solution to reduce the concentration of carbon dioxide in the atmosphere is the geologic storage of captured CO2 in underground rock formations, also known as carbon sequestration. There is ongoing research to guarantee that this process is both efficient and safe. We describe tools that provide measurements of media porosity, and permeability estimates, including visualization of pore structures. Existing standard algorithms make limited use of geometric information in calculating permeability of complex microstructures. This quantity is important for the analysis of biomineralization, a subsurface process that can affect physical properties of porous media. This paper introduces geometric and topological descriptors that enhance the estimation of material permeability. Our analysis framework includes the processing of experimental data, segmentation, and feature extraction and making novel use of multiscale topological analysis to quantify maximum flow through porous networks. We illustrate our results using synchrotron-based X-ray computed microtomography of glass beads during biomineralization. We also benchmark the proposed algorithms using simulated data sets modeling jammed packed bead beds of a monodispersive material.

Influence of lateral intercellular spaces on current propagation in tubular epithelia as estimated by a multi-cable model.

A multiple cable model has been developed for tubular epithelia which allows current flow along the tubular lumen, along the cell layer and inside the lateral intercellular space (LIS) to be quantitatively assessed. In this model tubular lumen and cell layer are represented by two concentric cylinders and the LIS by n concentric interconnected fluid layers which are interposed between the cells, contact the lateral cell membranes and extend all along the tubular length. The innermost LIS layer connects to the tight junctions and the outermost layer to the peritubular space. Modelling each element by a cable-like structure the mathematical solution leads to n + 2 linear combinations of n + 2 exponential functions. Based on morphometric data and resistance measurements on Necturus proximal tubule [4,10] model calculations have been performed of the voltage attenuation along tubular lumen, cell layer and LIS for n = 3 or n = 6 assuming different LIS widths (0.02, 0.2, and 2.0 micron). The results show that the influence of LIS is insignificant in Necturus proximal tubule under control conditions, but may become significant in other functional states or other tubules. Collapsing the LIS increases predominantly the shunt resistance and the effective resistance of the lateral cell membrane but longitudinal current propagation along the LIS remains negligible at all space widths. In addition, model calculations are presented which allow errors in determining tight junction resistance and cell membrane resistances from a simple cable model to be quantified as function of LIS width.

Electrophoretic analysis of the molecular weight of murine mammary tumor virus RNA.

Molecular weight determinations of native and subunit RNAs of murine mammary tumor virus (MuMTV), a type B oncornavirus, were performed by polyacrylamide gel electrophoresis and compared with molecular weights of well-characterized avian cellular RNAs and tobacco mosaic virus RNA. From extrapolations of semilog plots of the molecular weights of the standard RNAs versus relative electrophoretic mobilities and Ferguson plots, the subunit and native RNAs of MuMTV were found to possess molecular weights of 2.93 X 10(6) and 6.45 X 10(6), respectively. These data support the assumption that two subunit molecules comprise the native RNA of MuMTV.

Analysis of oncornavirus RNA subunits by electron microscopy.

Subunits of oncornavirus (avian myeloblastosis virus) RNA were isolated from purified 60--70S viral RNA by heat dissociation. Molecules sedimenting at 35 S, assumed to be the major component of the viral genome, were visualized in the electron microscope and their lengths were statistically analyzed. The results indicate a rather heterogeneous population of molecules with five distinct, reproducible size groups, an observation that excludes the assumption of random degradation of the genome. In addition, molecules of 28 and 18S RNA, always present in oncornavirus RNA preparations, were examined with the same methods. Some of these molecules possess secondary-structure regions similar to those characteristic for ribosomal RNA.

Visualization of single-stranded nucleic acid of RNA tumor virus with the electron microscope.

60-70S RNA of avian myeloblastosis virus was spread with the Kleinschmidt method and examined in the electron microscope after being subjected to a variety of denaturing conditions. Extension of the molecules from a collapsed configuration was seen only under stringent denaturing conditions, resulting in molecules of 1-2 mum in length. Longer strands of these extremely fragile molecules cannot be obtained with the methods presently available.

Deoxyribonucleic acid polymerase activity associated with a plasma particulate fraction from patients with chronic lymphocytic leukemia.

Plasma from two cases of chronic lymphocytic leukemia have been examined for deoxyribonucleic acid (DNA) polymerase activity. In both cases, detectable enzyme activity was present. In the plasma from a patient known to have chronic lymphocytic leukemia for 10 years, the enzyme activity was sufficiently high to study product formation, buoyant density of the enzyme activity, deoxyribonucleoside triphosphate requirements, and kinetics of DNA synthesis. These studies are presented in this report.

Deoxyribonucleic acid polymerase activity associated with strain MC29 tumor virus.

Chick embryo cells infected with strain MC29 tumor virus yielded progeny virus that contained detectable deoxyribonucleic acid (DNA) polymerase within the first 48 hr after infection. The noninfected culture fluids displayed no such enzyme activity when examined in an identical manner. Enzyme activity was greatly stimulated by adding DNA template to the reaction mixture and required all four deoxyribonucleoside triphosphates for full activity. When calf thymus DNA was used to direct synthesis, the DNA polymerase from the MC29 virus catalyzed the formation of DNA product having a higher buoyant density in CsCl. DNA product formed in the reaction directed by Micrococcus lysodeikticus DNA had the same buoyant density as the template DNA.