Experimental Observation of Proton Bunch Modulation in a Plasma at Varying Plasma Densities

We give direct experimental evidence for the observation of the full transverse self-modulation of a long, relativistic proton bunch propagating through a dense plasma. The bunch exits the plasma with a periodic density modulation resulting from radial wakefield effects. We show that the modulation is seeded by a relativistic ionization front created using an intense laser pulse copropagating with the proton bunch. The modulation extends over the length of the proton bunch following the seed point. By varying the plasma density over one order of magnitude, we show that the modulation frequency scales with the expected dependence on the plasma density, i.e., it is equal to the plasma frequency, as expected from theory.

Experimental Observation of Plasma Wakefield Growth Driven by the Seeded Self-Modulation of a Proton Bunch

We measure the effects of transverse wakefields driven by a relativistic proton bunch in plasma with densities of 2.1×10^{14} and 7.7×10^{14}  electrons/cm^{3}. We show that these wakefields periodically defocus the proton bunch itself, consistently with the development of the seeded self-modulation process. We show that the defocusing increases both along the bunch and along the plasma by using time resolved and time-integrated measurements of the proton bunch transverse distribution. We evaluate the transverse wakefield amplitudes and show that they exceed their seed value (<15  MV/m) and reach over 300  MV/m. All these results confirm the development of the seeded self-modulation process, a necessary condition for external injection of low energy and acceleration of electrons to multi-GeV energy levels.

Development of a BiTE®-mediated CD8+ cytotoxic T-lymphocyte activity assay to assess immunomodulatory potential of drug candidates in Cynomolgus macaque

The immunotoxic potential of drug candidates is assessed through the examination of results from a variety of studies and endpoints. While the functional assessment of CD8⁺ cytotoxic T-lymphocytes (CTL) is well-characterized in the clinic, the lack of a robust macaque CTL functional assay has been an important hurdle in evaluating and accurately quantifying cell-mediated CD8⁺ T-cell effector responses in the nonclinical setting. This paper describes the development of an assay to measure CTL activity in peripheral blood mononuclear cells (PBMC) isolated from Cynomolgus macaques. A human EGFR/CD3 Bispecific T-cell Engager (BiTE^®) was used to mount a robust CD8⁺ T-cell response in the presence of target-expressing cells. Upon target engagement, degranulation of CD107a and production of interferon (IFN)-γ both reliably indicated a robust functional response in CD8⁺ T-cells. The BiTE^®-mediated stimulation method proved to be favorable when compared to other methods of stimulation in the absence of target cells. These studies demonstrated acceptable longitudinal variability of the functional assay and sensitivity to dexamethasone-mediated immunosuppression. Taken together, the results indicated an assay leveraging CD3-bispecific antibodies and target-expressing cells can provide a robust approach to the in vitro or ex vivo assessment of CTL function in Cynomolgus macaques. Because the impairment of CTL activity by immunomodulators is recognized to be an important contributor to decreased antiviral defense and increased carcinogenicity risk, we believe that this novel assay to be a valuable addition to the immunotoxicology assessment of therapeutic drug candidates.

Behaviour of the Contact Phase of Blood Coagulation in the Adult Respiratory Distress Syndrome (ARDS)

In order to assess the role of the kallikrein-kinin (K-K) system in the pathogenesis of the adult respiratory distress syndrome (ARDS) we have prospectively determined coagulation contact phase, blood gas and hemodynamic parameters in patients with ARDS at 0, 36 and 72 h from diagnosis.

Compared to normal values, significantly lower mean levels of factor XII (71.4 ± 9.8%, p <0.0005), prekallikrein (PPK) (52 ± 5.7%, p <0.0005), high molecular weight kininogen (HMWK) (73 ± 2%, p <0.0005) and α2-macroglobulin (α2-M) (51 ± 7.1%, p <0.0005) were found in ARDS patients.

The functional kallikrein inhibitory activity (KKI) and Cr esterase inhibitor antigenic (CIINH) were significantly higher in these patients (113.2 ± 5, p <0.005 and 124.7 ± 7.6, p <0.0005 respectively) compared with normal values during the entire study period.

The KKI/CIINH ratio decreased significantly in our ARDS patients at 0, 36 and 72 h (p <0.025; p <0.05 and p <0.005 respectively).

We found a significant correlation between PPK levels and oxigenation index (r = 0.69, p <0.001), PPK and the static thoracic compliance values (r = 0.64, p <0.001). There was also a significant correlation between PPK levels and Qs/Qt (r = -0.89, p <0.001). ARDS patients that survived presented a stability in the PPK values in successive tests. Nevertheless non-survivors showed a progressive decrease in PPK levels during the follow-up period.

Our results suggest that the plasma kallikrein system becomes activated during ARDS and that this activation might increase the lung vessels’ permeability. In addition, PPK levels are in our opinion a useful prognostic parameter in predicting the outcome of ARDS patients.

Consumer acceptability of beef from two sexes supplemented with essential oil mix

Essential oils are natural extracts from plants which can be included in cattle diets as an alternative to additives, such as ionophores, to improve the shelf life of meat. The aim of this study was to evaluate the sensory acceptability of meat from 57 crossbred (1/2 Angus–1/2 Nellore) animals of different sexes [heifers n = 30, and young bulls n = 27], finished in feedlot with isoenergetic and isonitrogenous diets, which differed in the level of supplementation (0.0, 3.5 or 7.0 g/animal/day) with a commercial mix of essential oils (Mixoil®) from seven plants: oregano, garlic, lemon, rosemary, thyme, eucalyptus and sweet orange. The Longissimus thoracis muscle, aged for 24 h, was evaluated by 120 consumers who scored tenderness acceptability, flavour acceptability and overall acceptability using a hedonic 9-point scale. The inclusion of essential oils affected tenderness acceptability and flavour acceptability (P ≤ 0.01), with a tendency (P < 0.10) for overall acceptability. Meat from heifers was more appreciated by consumers than that from young bulls in all attributes (P ≤ 0.001), however, different groups of consumers had different preferences. The inclusion of a mix of essential oils in beef diets was well accepted by consumers, and could improve the acceptability of meat from young bulls, when is added at a concentration of 3.5 g/animal/day during the last 4 months of fattening.

Experience in the treatment of osseous hydatidosis

Osseous hydatidosis is a very uncommon disease which often recurs after treatment. There is no well-established effective method of management. Radical excision may produce serious mutilation and often fails to control the disease. We have used oral mebendazole as adjuvant treatment in four patients. Two also underwent radical excision, one had received limited excision elsewhere and the other did not have operative treatment. The patients who underwent radical excision and the other who did not have an operation became and remain free of symptoms and are serologically negative.A combination of excision and treatment with mebendazole may have a role in the management of this complex disease.

Assessing the immunomodulatory potential of therapeutic agents in cynomolgus macaque cytotoxic T lymphocytes

The preclinical evaluation of therapeutic agents contributes to the understanding of associated risks and benefits. The non-human primate, and notably the cynomolgus macaque, is often a species of choice for such pharmacological and toxicological assessments. The degree of immunomodulation associated with these agents, intended or not, is a critical point to consider in that context. While there are tools to immunophenotype and enumerate effector T cells, the knowledge gap surrounding the functional characterization of cytotoxic T lymphocytes (CTL) persists. Here we present a multi-parametric cynomolgus macaque CTL functional assay. By using an EGFR expressing target cell line co-cultured with cynomolgus peripheral blood mononuclear cells (PBMC) and an EGFR Bispecific T Cell Engager (BiTE®), we were able to redirect lysis in a target-specific manner. In this assay we simultaneously monitored cytolytic potential (CD107a) and cytokine secretion (IFN-γ and TNF-α) of effector CTL against target cell growth. Overall our results demonstrate the ability to assess cynomolgus CTL function under known immunosuppressive agents, thereby enabling a multi-parametric approach of monitoring the impact of investigational drugs on an important component of the immune system.