Pharmacological interrogation of a rodent forced ambulation model: leveraging gait impairment as a measure of pain behavior pre-clinically.

OBJECTIVE: The aim of this study was to investigate whether inflammogen-induced temporal and spatial gait changes in a rodent forced-ambulation paradigm were sensitive to pharmacological intervention with both clinically validated and novel analgesics. METHODS: Using the GaitScan (CleverSys Inc., Reston, VA) treadmill system, we identified four functional endpoints inspired by clinical literature and sensitive to unilateral joint injury induced by intra-articular Complete Freund's Adjuvant (CFA). These endpoints included: range of motion, normalized stance distance, stance/swing ratio, and paw print size as a measure of guarding; collectively, these measures are proposed to serve as a high fidelity index of joint pain. We then examined the ability of known analgesic mechanisms to attenuate gait impairment as measured by this index. RESULTS: Clinically efficacious opioids, Nonsteroidal anti-inflammatory drugs (NSAIDs), and the yet unapproved anti-NGF antibody dose-dependently attenuated the CFA)-induced gait deficits, while a TNF-alpha fusion protein blocker had no effect on gait, but did produce a reduction in swelling. As well, the time course for gait impairment in the model appears to be distinct from the traditional endpoint of tactile hypersensitivity, offering the potential to assess a novel functional pain phenotype. CONCLUSIONS: In response to the call for more functional pain measures, we submit this composite gait score as a novel endpoint to interrogate joint pain pre-clinically. As the etiology of human osteoarthritis (OA) remains unclear, this model/endpoint cannot attempt to improve construct validity, but may provide an additional dimension to interrogate pain-induced gait deficits.

Survival of Helicobacter pylori in a natural freshwater environment.

The mode by which Helicobacter pylori, the causative agent of most gastric ulcers, is transmitted remains undetermined. Epidemiological evidence suggests these organisms are waterborne; however, H. pylori has rarely been grown from potential water sources. This may be due to the ability of this organism to rapidly enter the viable but nonculturable (VBNC) state. Our investigation examines the entrance of H. pylori into this state in laboratory cultures and a natural freshwater environment as well as the relationship between morphology and culturability. To this end, membrane diffusion chambers were utilized to expose the cells to the natural fluctuations of a freshwater stream. In both the laboratory and environment, samples were assayed for culturability using plate counts and stained using a LIVE/DEAD BacLight assay for viability and morphological determinations. Additionally, water samples were collected, six environmental parameters were measured, and resuscitation conditions were examined. H. pylori was observed to lose culturability in the laboratory and stream, although viability was maintained. While the results of our study agree with those of previous studies which suggested that there is a transition in morphology from rods to cocci as culturability is lost, the morphological distribution of cells did not change as culturability was lost in the environment. The majority of cells in the VBNC state in the laboratory are cocci; however, all morphological forms were present in the environment. The results of these studies suggest that H. pylori persists in laboratory cultures and the environment in the VBNC state and that cells in this state represent a public health hazard.

Mapping the mesoscale interface structure in polycrystalline materials.

A new experimental approach to the quantitative characterization of polycrystalline microstructure by scanning electron microscopy is described. Combining automated electron backscattering diffraction with conventional scanning contrast imaging and with calibrated serial sectioning, the new method (mesoscale interface mapping system) recovers precision estimates of the 3D idealized aggregate function G(x). This function embodies a description of lattice phase and orientation (limiting resolution approximately 1 degree) at each point x (limiting spatial resolution approximately 100 nm), and, therefore, contains a complete mesoscale description of the interfacial network. The principal challenges of the method, achieving precise spatial registry between adjacent images and adequate distortion correction, are described. A description algorithm for control of the various components of the system is also provided.

Nursing education for critical thinking: an integrative review.

This integrative review summarizes 20 research studies reported from 1977 to 1995 that review change in the critical thinking abilities of professional nursing students. The Watson-Glaser Critical Thinking Analysis was used in 18 of 20 studies. The primary assumption was that critical thinking skills would increase during nursing education. However, the results of this review are mixed and contradictory. Possible reasons for these results are discussed.

Single photon emission computerized tomography in obsessive compulsive disorder: a preliminary study.

Patterns of cerebral perfusion in patients with obsessive compulsive disorder were evaluated using single photon emission computerized tomography. Eleven patients, who satisfied the DSM-III-R criteria and Research Diagnostic Criteria for the disorder, were evaluated using the distribution of 99m-Tc-HMPAO as a radiotracer. The Yale-Brown Obsessive Compulsive Scale was administered to each patient to assess the severity of their symptoms. The images obtained were evaluated qualitatively and semi-quantitatively by a physician in nuclear medicine who was blind to the patients' diagnoses. Eight of the 11 patients demonstrated asymmetric perfusion of the basal ganglia; the left side showed impaired perfusion in six patients.

The effect of "cap" analogs on reovirus mRNA binding to wheat germ ribosomes. Evidence for enhancement of ribosomal binding via a preferred cap conformation.

A variety of compounds related to the 5'-terminal "cap" (m7GpppN) of eukaryotic mRNA's were chemically synthesized and tested as inhibitors of reovirus mRNA binding to wheat germ ribosomes. Under our conditions of mRNA binding to ribosomes, 7-methyl-, 7-ethyl-, and 7-benzyl-GDP, but not GDP, decreased stable initiation complex formation by 70 to 80% at a concentration of 0.1 mM indicating that 7-substitution, but not a specific substituent, was required for the effect. Elimination of the positive charge on the imidazole of the 7-substituted compounds by treatment with alkali destroyed their inhibitory activity. Similarly, reduction to 8-hydro-m7GDP reversibly decreased the activity of m7GDP. The results were consistent with the hypothesis that the positive charge resulting from 7-alkylation provides an active cap conformer for binding via interaction of phosphate oxygens with the positively charged imidazole moiety. In accord with this suggestion, 7-carboxymethyl GDP and 7,8-dimethyl GDP were found to be less inhibitory than m7GDP. A 2-amino group was also important since m7IDP was less effective than m7GDP and 0.1 mM m7XDP did not inhibit ribosome binding. Other poor inhibitors were 6-Cl-m7GDP and 1,7-dimethyl GDP but N2,7-dimethyl GDP, 2'-deoxy-m7GDP, and m7GppI had essentially the same activity as m7GDP.

Immunologic responses to Candida albicans. III. Effects of passive transfer of lymphoid cells or serum on murine candidiasis.

Passive transfer of immune serum gave a significant degree of protection against deep seated candidiasis in mice. Repeated attempts to transfer resistance by the transfer of sensitized lymphoid cells gave negative results, even though cutaneous delayed hypersensitivity was transferred by the cells. The results suggest that cell-mediated immunity is not of primary importance in this model of murine candidiasis, and that humoral immunity contributes to protection.

Steelhead migration: potential temperature effects as indicated by gill adenosine triphosphatase activities.

Yearling steelhead trout held in fresh water at cold temperatures (6.5 degrees or 10 degrees C) showed an increase in gill microsomal Na(+), K(+)-stimulated adenosine triphosphatase activity during parr-smolt transformation, whereas trout held in warm water (15 degrees or 20 degrees C) did not. Adenosine triphosphatase activity increased and other indications of transformation were observed in fish transferred from warm to cold water, whereas the reverse occurred on transfer from cold to warm water.