Characterisation of the porcine cytokines which activate the CD131ßc common sub-unit, for potential immune-augmentation.

Early acting cytokines and growth factors such as those of the CD131 ßc subunit, may offer an alternative method to the current use of antibiotics and chemicals such as anthelmintics in maintaining Porcine (Po) health. Thus far, the recombinant Po (rPo) Granulocyte-macrophage colony-stimulating factor (GM-CSF), rPo interleukin-3 (IL-3) and rPo interleukin-5 (IL-5) proteins have been identified and cloned and the biological activity of each cytokine has been confirmed in vitro, however, in vivo immune system regulation and hematopoietic stem cell (HSC) augmentation are regulated by numerous cytokines and cellular signals within the bone marrow (BM) niche. In order to quantify the use of recombinant cytokines in augmenting the immune response, it is necessary to determine the stages of hematopoiesis induced by each cytokine and possible areas of synergy requiring further investigation. Here we used the chemotherapeutic agent 5-fluorouracil (5-FU), to chemically induce a state of myelosuppression in young pigs. This allowed for the monitoring of both the autologous BM reconstitution and recombinant cytokine induced BM repopulation, precursor cell proliferation and cellular differentiation. The recombinant cytokines PoGM-CSF, PoIL-3 and PoIL-5 were administered by intramuscular injections (i.m.) following confirmation of 5-FU induced leukocytopenia. Blood and BM samples were collected and then analysed for cell composition. Statistically significant results were observed in several blood cell populations including eosinophils for animals treated with rPoIL-5, rPoGM-CSF and basophils for animals treated with rPoIL-3. BM analysis of CD90+ and CD172a+ cells confirmed myelosuppression in week one with significant results observed between rPoIL-3 and the 5-FU control group in week two and for the rPoGM-CSF group in week three. These results have demonstrated the effects of each of these rPo cytokines within the hematopoietic processes of the pig and may demonstrate similar outcomes in other mammalian models including human.

Diocotron and Kelvin mode damping from a flux through the critical layer.

Experiments and theory characterize a novel type of spatial Landau damping, caused by a flux of particles through the wave or rotation resonance (critical) layer. Pure electron plasma experiments demonstrate that a steady flux of particles causes algebraic damping of diocotron mode amplitudes for azimuthal modes m = 1 and m = 2, and a simple model of dynamics in the nonlinear cat's eye clarifies the observations. This flux-driven algebraic damping is related to, but distinct from, the exponential decay characteristic of Landau damping. This flux-driven damping applies also to Kelvin waves on 2D vortices, and so may be broadly relevant to plasmas and geophysical flows.

Effective strategy for decreasing blood culture contamination rates: the experience of a Veterans Affairs Medical Centre.

Contaminated blood cultures constitute diagnostic challenges and place a burden on healthcare services. An observational retrospective study was undertaken to evaluate the effect of routine labelling of blood culture bottles with the initials of the healthcare worker who drew them, followed by individualized feedback, on blood culture contamination rates. The contamination rate of the entire facility was 2.6% before the procedural change, and this decreased significantly to 1.5% after the procedural change (P < 0.001) over the first 12 months of the intervention. Routine labelling of blood culture bottles with the initials of the healthcare worker who drew them, followed by individualized feedback, was effective in reducing blood culture contamination rates.

Evidence that mechanosensors with distinct biomechanical properties allow for specificity in mechanotransduction.

Various cell types can sense and convert mechanical forces into biochemical signaling events through a process called mechanotransduction, and this process is often highly specific to the types of mechanical forces applied. However, the mechanism(s) that allow for specificity in mechanotransduction remain undefined. Thus, the goal of this study was to gain insight into how cells distinguish among specific types of mechanical information. To accomplish this goal, we determined if skeletal myoblasts can distinguish among differences in strain, strain rate, and strain-time integral (STI). Our results demonstrate that mechanically induced signaling through the c-jun N-terminal kinase 2 [JNK2] is elicited via a mechanism that depends on an interaction between the magnitude of strain and strain rate and is independent of STI. In contrast to JNK2, mechanically induced signaling through the ribosomal S6 kinase [p70(389)] is not strain rate sensitive, but instead involves a magnitude of strain and STI dependent mechanisms. Mathematical modeling also indicated that mechanically induced signaling through JNK2 and p70(389) can be isolated to separate viscous and elastic mechanosensory elements, respectively. Based on these results, we propose that skeletal myoblasts contain multiple mechanosensory elements with distinct biomechanical properties and that these distinct biomechanical properties provide a mechanism for specificity in mechanotransduction.

Measurement of correlation-enhanced collision rates.

We measure the perpendicular-to-parallel collision rate nu perpendicular parallel in laser-cooled magnetized ion plasmas, spanning the uncorrelated to correlated regimes. In correlated regimes, we measure collision rates consistent with the "Salpeter correlation enhancement" of roughly exp(Gamma), for correlation parameters Gamma less, similar 4. This enhancement also applies to fusion in dense plasmas such as stars.

The role of phosphoinositide 3-kinase and phosphatidic acid in the regulation of mammalian target of rapamycin following eccentric contractions.

Resistance exercise induces a hypertrophic response in skeletal muscle and recent studies have begun to shed light on the molecular mechanisms involved in this process. For example, several studies indicate that signalling by the mammalian target of rapamycin (mTOR) is necessary for a hypertrophic response. Furthermore, resistance exercise has been proposed to activate mTOR signalling through an upstream pathway involving the phosphoinositide 3-kinase (PI3K) and protein kinase B (PKB); however, this hypothesis has not been thoroughly tested. To test this hypothesis, we first evaluated the temporal pattern of signalling through PI3K-PKB and mTOR following a bout of resistance exercise with eccentric contractions (EC). Our results indicated that the activation of signalling through PI3K-PKB is a transient event (<15 min), while the activation of mTOR is sustained for a long duration (>12 h). Furthermore, inhibition of PI3K-PKB activity did not prevent the activation of mTOR signalling by ECs, indicating that PI3K-PKB is not part of the upstream regulatory pathway. These observations led us to investigate an alternative pathway for the activation of mTOR signalling involving the synthesis of phosphatidic acid (PA) by phospholipase D (PLD). Our results demonstrate that ECs induce a sustained elevation in [PA] and inhibiting the synthesis of PA by PLD prevented the activation of mTOR. Furthermore, we determined that similar to ECs, PA activates mTOR signalling through a PI3K-PKB-independent mechanism. Combined, the results of this study indicate that the activation of mTOR following eccentric contractions occurs through a PI3K-PKB-independent mechanism that requires PLD and PA.

Wave-particle interactions in electron acoustic waves in pure ion plasmas.

Electron acoustic waves (EAW) with a phase velocity less than twice the plasma thermal velocity are observed on pure ion plasma columns. At low excitation amplitudes, the EAW frequencies agree with theory, but at moderate excitation the EAW is more frequency variable than typical Langmuir waves, and at large excitations resonance is observed over a broad range. Laser induced fluorescence measurements of the wave-coherent ion velocity distribution show phase reversals and wave-particle trapping plateaus at +/-vph, as expected, and corroborate the unusual role of kinetic pressure in the EAW.

Resonant drift-wave coupling modified by nonlinear separatrix dissipation.

Resonant drift-wave coupling experiments characterize a new dissipative coupling term caused by a trapping separatrix. The system is a cylindrical pure-electron plasma with an axial trapping separatrix generated by an applied theta-symmetric wall voltage. The resonant decay of m_{theta}=2 diocotron modes into m_{theta}=1 trapped-particle diocotron modes is measured and compared to parametric mode coupling theory. Experiments quantify the traditional nonlinear mode coupling term, plus a new separatrix-generated dissipative coupling term which is not yet characterized theoretically.

High-density fixed point for radially compressed single-component plasmas.

Rotating electric fields are used to compress electron plasmas confined in a Penning-Malmberg trap. Bifurcation and hysteresis are observed between low-density and high-density steady states as a function of the applied electric field amplitude and frequency. These observations are explained in terms of torque-balanced fixed points using a simple model of the torques on the plasma. Perturbation experiments near the high-density fixed point are used to determine the magnitude, frequency, and voltage dependence of the drive torque. The broader implications of these results are discussed.

Fluid echoes in a pure electron plasma.

Experimental observations of diocotron wave echoes on a magnetized electron column are reported, representing Kelvin wave echoes on a rotating near-ideal fluid. The echoes occur by reversal of an inviscid wave damping process, and the phase-space mixing and unmixing are directly imaged. The basic echo characteristics agree with a simple nonlinear ballistic theory. At late times, the echo is degraded, and the maximal observed echo times agree with a theory of electron-electron collisions acting on separately evolving velocity classes.

Polarization and trapping of weakly bound atoms in penning trap fields.

The ATHENA and ATRAP groups at CERN recently reported the production of weakly bound antihydrogen atoms in a non-neutral positron-antiproton plasma. This Letter derives an equation of motion for weakly bound atoms in the electric and magnetic fields of the plasma and trap. The atoms are polarized by the electric field and can be trapped radially in the edge region of the plasma where the electric field is maximum.

Damping of the trapped-particle diocotron mode.

The damping mechanism of a recently discovered trapped-particle mode is identified as collisional velocity scattering of marginally trapped particles. The mode exists on non-neutral plasma columns that are partially divided by an electrostatic potential. This damping mechanism is similar to that responsible for damping of the dissipative trapped-ion mode. The damping rate is calculated using a Fokker-Planck analysis and agrees with measurement to within 50%. Also, an experimental signature confirms a causal relation between scattering of marginally trapped particles and damping.

Numerical simulation of ultracold plasmas: how rapid intrinsic heating limits the development of correlation.

In recent experiments, ultracold plasmas were produced by photoionizing small clouds of laser-cooled atoms. It has been suggested that the low initial temperature of these novel plasmas leads directly to strong correlation and order. In contrast, we argue that rapid intrinsic heating raises the electron temperature to the point where strong correlation cannot develop. The argument is corroborated by a molecular-dynamics simulation of the early-time plasma evolution.

Cervical dystonia severity scale reliability study.

Cervical dystonia (CD) is characterized by sustained contractions of the neck musculature, resulting in abnormal head postures. The Cervical Dystonia Severity Scale (CDSS) was developed to provide a reliable measure of treatment response in patients with CD. The CDSS uses a protractor and wall chart to rate the severity of the head's deviation from neutral in each of three planes of motion (rotation, laterocollis, anterocollis/retrocollis), which is then scored in 5 degree intervals (1 degree to 5 degrees deviation = 1; 86 degree to 90 degrees deviation = 18). To test the reliability of the CDSS, four centers, each with two independent examiners, evaluated 42 patients with CD. At each site, each of the two examiners used the CDSS to evaluate the head position of each patient twice, on the same day, for a total of four evaluations. The kappa value for intra-examiner agreement was 0.94 (95% confidence limit of 0.900-0.972), indicating excellent intra-examiner reliability. The kappa value for interexaminer reliability was 0.79 for the first evaluation and 0.86 for the second evaluation (95% confidence limits of 0.668-0.920 and 0.790-0.920) indicating excellent interexaminer reliability. Thus, the CDSS was highly reliable in both intra-examiner and interexaminer scoring comparisons.

Trapped-particle asymmetry modes in single-species plasmas.

Novel trapped-particle asymmetry modes propagate on cylindrical electron columns when axial variations in the wall voltage cause particle trapping. These modes consist of E x B drifts of edge-trapped particles, partially shielded by axial flows of interior untrapped particles. A simple model agrees well with the observed frequencies and eigenfunctions, but the strong mode damping is as yet unexplained. These modes may be important in coupling trap asymmetries to particle motions and low frequency E x B drift modes.

High-level production of recombinant chicken interferon-gamma by Brevibacillus choshinensis.

Cytokines, such as interferon-gamma have been shown to have adjuvant and growth promoting activity in poultry and livestock and have the potential to be used as alternatives to antibiotics. We have developed an efficient system for commercial-scale synthesis of recombinant chicken interferon-gamma (ChIFN-gamma) using Brevibacillus choshinensis as the host for protein production. The ChIFN-gamma expression vector, pNCIFN, was constructed using the novel Escherichia coli-B. choshinensis shuttle vector, pNCMO2. ChIFN-gamma expression was optimized by investigating different culture conditions and different host B. choshinensis mutants. The highest level of production was observed using the B. choshinensis HPD31-MB2 strain grown at 30 degrees C, where ChIFN-gamma was produced at approximately 300-500 mg/L. ChIFN-gamma was also produced as a His-tagged fusion protein by using the pNCHis-IFN expression vector, a derivative of pNCMO2. The protein was constitutively secreted into the culture supernatant and could be partially purified in a single step using a Ni-nitrilotriacetic acid column. This recombinant His-ChIFN-gamma was shown to have the same biological activity as native ChIFN-gamma.

Positive and negative daily events, perceived stress, and alcohol use: a diary study.

Using daily diary methodology, the authors examined over 60 days the within-person associations among positive and negative daily experiences, perceptions of stress, desire to drink, and alcohol consumption in a sample of 83 regular drinkers. Multilevel regression analyses indicated that days on which individuals reported more positive and negative nonwork events were also days they reported higher levels of desire to drink and actual consumption. Days on which individuals reported more negative work events were also days they reported a greater desire to drink, and days on which individuals reported more positive and negative health events were also days they reported lower levels of desire to drink and actual consumption. Weak evidence was found for the mediating effects of perceived stress in these associations. Several of the within-person associations varied as a function of gender, neuroticism, and drinking to cope; no moderating effects were found for extraversion.

Stress and alcohol use: a daily process examination of the stressor-vulnerability model.

The authors used a daily diary methodology to examine over 60 days how the within-person associations among event stress, alcohol consumption, and desire to drink varied as a function of gender, positive and negative alcohol-outcome expectancies, and avoidant coping in a sample of 88 regular drinkers. Multilevel regression analyses indicated that men who more strongly anticipated positive outcomes or a sense of carelessness from drinking drank relatively more on stressful days compared with low-stress days. Similar results were found predicting desire to drink. Men who anticipated greater impairment from drinking drank relatively less on stressful days. In general, these effects did not hold for women. Little evidence was found for the predicted effects for avoidant coping style, and some results showed that avoidant coping style buffered the exacerbating effects of careless unconcern expectancies.

Cytokine therapy: a natural alternative for disease control.

Disease control in food production animals is normally mediated through the use of vaccines, chemicals and antibiotics. However, the extensive use of antibiotics and chemicals in livestock has resulted in environmental and human health concerns, particularly with regard to the emergence of drug-resistant bacteria in the food chain. In fact, the World Health Organisation (WHO) has now urged meat producers to use environmentally-friendly alternative methods to control disease. Cytokines, as natural mediators of the immune response, offer exciting alternatives to conventional therapeutics. The utilisation of cytokines is becoming more feasible with the recent cloning of a number of cytokine genes. Since the chicken's immune system is similar to that of mammals, they offer an attractive model system with which to study the effectiveness of cytokine therapy in the control of disease in intensive livestock. In this report we will review our recent studies on the therapeutic potential of chicken interferon gamma (ChIFN-gamma) as a vaccine adjuvant and a growth promoter.

Design and in vivo analysis of potent non-thiol inhibitors of farnesyl protein transferase.

Inhibitors of farnesyl protein transferase (FPTase) based upon a pseudotripeptide template are described that comprise an imidazole group substituted with a hydrophobic substituent. (1, 5)-Disubstitution of the imidazole group is shown to be the optimal array that leads to potent and selective inhibitors of FPTase. A variety of aryl and isoprenyl substituents are shown to afford effective inhibitors, and the mechanism by which these compounds inhibit FPTase has been investigated. The biochemical behavior of these compounds suggests that they bind to FPTase at the site usually occupied by the protein substrate. In experiments in cell culture, the methyl ester prodrugs of these inhibitors are cell permeant and potently inhibit the posttranslational modification of H-Ras protein. Additionally, these molecules revert the phenotype of ras transformed cells as evidenced by their ability to slow the growth of ras transformed cell lines in soft agar. One of the inhibitors, as its methyl prodrug, was evaluated in two in vivo models of tumor growth. The compound selectively inhibited the growth of tumors derived from H-ras transformed cells, in nude mice, and caused the regression of preexisting tumors in an H-ras transgenic animal model.