Characterization of Quasi-Keplerian, Differentially Rotating, Free-Boundary Laboratory Plasmas

We present results from pulsed-power driven differentially rotating plasma experiments designed to simulate physics relevant to astrophysical disks and jets. In these experiments, angular momentum is injected by the ram pressure of the ablation flows from a wire array Z pinch. In contrast to previous liquid metal and plasma experiments, rotation is not driven by boundary forces. Axial pressure gradients launch a rotating plasma jet upward, which is confined by a combination of ram, thermal, and magnetic pressure of a surrounding plasma halo. The jet has subsonic rotation, with a maximum rotation velocity 23±3  km/s. The rotational velocity profile is quasi-Keplerian with a positive Rayleigh discriminant κ^{2}∝r^{-2.8±0.8}  rad^{2}/s^{2}. The plasma completes 0.5-2 full rotations in the experimental time frame (∼150  ns).

Perpendicular Subcritical Shock Structure in a Collisional Plasma Experiment

We present a study of perpendicular subcritical shocks in a collisional laboratory plasma. Shocks are produced by placing obstacles into the supermagnetosonic outflow from an inverse wire array z pinch. We demonstrate the existence of subcritical shocks in this regime and find that secondary shocks form in the downstream. Detailed measurements of the subcritical shock structure confirm the absence of a hydrodynamic jump. We calculate the classical (Spitzer) resistive diffusion length and show that it is approximately equal to the shock width. We measure little heating across the shock (<10% of the ion kinetic energy) which is consistent with an absence of viscous dissipation.

An imaging refractometer for density fluctuation measurements in high energy density plasmas

We report on a recently developed laser-probing diagnostic, which allows direct measurements of ray-deflection angles in one axis while retaining imaging capabilities in the other axis. This allows us to measure the spectrum of angular deflections from a laser beam, which passes through a turbulent high-energy-density plasma. This spectrum contains information about the density fluctuations within the plasma, which deflect the probing laser over a range of angles. We create synthetic diagnostics using ray-tracing to compare this new diagnostic with standard shadowgraphy and schlieren imaging approaches, which demonstrates the enhanced sensitivity of this new diagnostic over standard techniques. We present experimental data from turbulence behind a reverse shock in a plasma and demonstrate that this technique can measure angular deflections between 0.06 and 34 mrad, corresponding to a dynamic range of over 500.

Collective optical Thomson scattering in pulsed-power driven high energy density physics experiments (invited)

Optical collective Thomson scattering (TS) is used to diagnose magnetized high energy density physics experiments at the Magpie pulsed-power generator at Imperial College London. The system uses an amplified pulse from the second harmonic of a Nd:YAG laser (3 J, 8 ns, 532 nm) to probe a wide diversity of high-temperature plasma objects, with densities in the range of 10¹⁷-10¹⁹ cm^-3 and temperatures between 10 eV and a few keV. The scattered light is collected from 100 μm-scale volumes within the plasmas, which are imaged onto optical fiber arrays. Multiple collection systems observe these volumes from different directions, providing simultaneous probing with different scattering K-vectors (and different associated α-parameters, typically in the range of 0.5-3), allowing independent measurements of separate velocity components of the bulk plasma flow. The fiber arrays are coupled to an imaging spectrometer with a gated intensified charge coupled device. The spectrometer is configured to view the ion-acoustic waves of the collective Thomson scattered spectrum. Fits to the spectra with the theoretical spectral density function S(K, ω) yield measurements of the local plasma temperatures and velocities. Fitting is constrained by independent measurements of the electron density from laser interferometry and the corresponding spectra for different scattering vectors. This TS diagnostic has been successfully implemented on a wide range of experiments, revealing temperature and flow velocity transitions across magnetized shocks, inside rotating plasma jets and imploding wire arrays, as well as providing direct measurements of drift velocities inside a magnetic reconnection current sheet.

Evaluation of brain-derived neurotrophic factor in menstrual blood and its identification in human endometrium

The presence of high-affinity brain-derived neurotrophic factor receptor Trk B in mouse and in human fetal oocytes, together with the presence of neurotrophins in human follicular fluid suggests a paracrine role for brain-derived neurotrophic factor (BDNF) in female biology. This study aims to evaluate if BDNF is present and quantitatively determined in human menstrual blood and endometrium. Twenty-one women were studied and subdivided in two groups: A, 11 fertile women (27 ± 2 days cycle length) and B, 10 anovulatory women and/or women with inadequate luteal phase (36 ± 2 days cycle length). In fertile women menstrual BDNF levels was higher than plasma (679.3 ± 92.2 vs 301.9 ± 46.7 pg/ml p <0.001). Similarly, in Group B, BDNF in menstrual blood was higher than plasma (386.1 ± 85.2 vs 166.8 ± 24.1 pg/ml p < 0.001). Moreover, both menstrual and plasma BDNF concentrations in Group A were significantly higher respect to Group B (679.3 ± 92.2 vs 386.1 ± 85.2 pg/ml p < 0.001; 301.9 ± 46.7 vs 166.8 ± 24.1 pg/ml p < 0.001). Immunohistochemistry evidence of BDNF in endometrium, during follicular and luteal phase, was also shown. The detection of BDNF in the human menstrual blood and endometrium further supports the role of this neurotrophin in female reproductive function.

Central modifications of allopregnanolone and beta-endorphin following subcutaneous administration of Nestorone

The aim of the present study was to evaluate the potential action of Nestorone (alone or in combination with estradiol valerate) on the level of allopregnanolone and of the opioid beta-endorphin in selected brain areas. Wistar ovariectomized rats were given 0.05 mg/(kg day) of estradiol valerate (E2V) or subcutaneous Nestorone at three dose levels: low dose (10 microg/(kg day)), antiovulatory dose (50 micro/(kg day)) and high dose (250 microg/(kg day)) with and without E2V. E2V therapy reversed the reduction of allopregnanolone and beta-endorphin induced by ovariectomy anywhere was analyzed except for the adrenal gland. Nestorone showed no effect on allopregnanolone concentration in serum or any part of the brain tissue when given alone while it had a synergistic increasing effect in allopregnanolone concentration in some parts of the brain (hippocampus, hypothalamus, anterior pituitary and serum) when given at high dose of 250 microg/(kg day) in combination with E2V. At lower doses it possesses a synergistic effect with E2V only in the hippocampus (at 50 microg/(kg day)) and in the anterior pituitary (at 10 and 50 microg/(kg day)). Nestorone administered alone at any dose led to significant increase in beta-endorphin levels in the hippocampus only while, in the high dose group, there was a significant increase in endorphin levels in anterior pituitary and hypothalamus in addition to hippocampus as compared to ovariectomized control rats. In addition, only the highest dose of Nestorone added to estrogen increased beta-endorphin levels of hippocampus and plasma. Thus the lower doses of Nestorone alone or in combination with estrogen do not seem to exert any great effect on both allopregnanolone and beta-endorphin. It is only the highest dose of Nestorone that increases allopregnanolone and beta-endorphin levels in selected brain areas, which are the hippocampus, the hypothalamus, the anterior pituitary and serum/plasma. This suggests that Nestorone at the antiovulatory dose levels may not alter the positive effects of estrogen treatment on mood and behaviour.

Progestogens and brain: an update

Each synthetic progestins has its own specific activities on different tissues, which can vary significantly between progestins of different classes and even within the same class. Indeed, different progestins may support or oppose the effects of estrogen depending on the tissue, thereby supporting the concept that the clinical selection of progestins for HRT is critical in determining potential positive or detrimental effects. These actions might be particularly relevant in the central nervous system (CNS) where progesterone (P) has pivotal roles besides reproduction and sexual behavior, going from neuropsychological effects to neuroprotective functions. Growing evidence supports the idea that synthetic progestins differ significantly in their brain effects, and clinical studies indicate that these differences also occur in women. Molecular and cellular characterization of the signaling properties of synthetic progestins in brain cells is therefore required and is hoped will lead to a better clinical utilization of the available compounds, as well as to new concepts in the engineering of new molecules. The aim of the present paper is to briefly review and compare neuroendocrine effects of progestogens with special reference to P metabolism into neuroactive steroids and the opioids system.

Influence of co-medication with sirolimus or cyclosporine on mycophenolic acid pharmacokinetics in kidney transplantation

The pharmacokinetics of mycophenolic acid (MPA)--the active metabolite of mycophenolate mofetil (MMF)--is significantly influenced by co-medications. The impact of sirolimus on daily MPA exposure, however, has not been investigated so far. As a part of the study aimed at investigating the efficacy of Campath-1H induction therapy in a steroid-free regimen in kidney transplantation, MPA plasma levels were serially measured in 21 patients treated with low-dose sirolimus (SRL) or low-dose CsA both in addition to low-dose MMF over 12 months post-operatively. Full pharmacokinetic profiles were compared at month 6 and 12 post-surgery. Mean dose-adjusted MPA trough levels were 4.4-fold higher in patients on combined SRL and MMF than in those given CsA and MMF. Pharmacokinetic studies demonstrated that mean MPA C(max) and T(max) were comparable in the two groups, while mean MPA AUC(0-12) was higher in SRL than CsA treated patients. The pharmacokinetic profile of SRL- but not of CsA-group showed a second peak consistent with the enterohepatic recirculation of MPA. These findings suggest that SRL and CsA have different effects on MPA metabolism and/or excretion eventually affecting its immunosuppressive property and/or toxicity. CsA, but not SRL, inhibits MPA enterohepatic recirculation, reducing MPA daily exposure.

Eotaxin and CCR3 are up-regulated in exacerbations of chronic bronchitis

BACKGROUND

Eosinophils and T lymphocytes represent constant features in the airways of subjects with exacerbated chronic bronchitis. Eotaxin is the most potent and selective eosinophil chemoattractant which can also attracts lymphocytes. The aim of the study was to evaluate the expression of eotaxin and its receptor, CCR3, in bronchial airways during exacerbation of chronic bronchitis.

METHODS

By immunohistochemistry we studied eotaxin and CCR3 expression in the lamina propria of 14 subjects with acute exacerbation of chronic bronchitis. 20 asthmatics, and 8 healthy subjects. We determined the cell types expressing the CCR3 receptor by colocalization experiments. We finally studied the relationship between eotaxin and CCR3 and eosinophils and T lymphocytes.

RESULTS

The number of eotaxin+ and CCR3+ cells was significantly higher in exacerbated chronic bronchitis (P<0.003 and P<0.002) and asthma (P<0.002 and P<0.0001) when compared to healthy subjects. CCR3 was mainly expressed by eosinophils and to a lesser extent by CD4+ and CD8+ lymphocytes. In exacerbated chronic bronchitis the number of CCR3+ cells was strongly correlated to the number of eosinophils (P<0.0002. r=0.85) and to the number of CD4+ lymphocytes (P<0.05, r=0.57).

CONCLUSION

Our study suggests that eotaxin and CCR3 are up-regulated and could be involved in the eosinophil and CD4+ lymphocyte recruitment into the airways which occur during acute exacerbations of chronic bronchitis.

Iopiperidol: nonionic iodinated contrast medium with promising anticoagulant and antiplatelet properties

RATIONALE AND OBJECTIVES

The purpose of this study was to determine the anticoagulant and antiplatelet characteristics of iopiperidol, a nonionic, triiodinated contrast agent.

MATERIALS AND METHODS

Anticoagulant effects of iopiperidol were assessed both in vitro and in vivo after single or repeated intravenous administrations to rats. To this aim, results of prothrombin time, activated partial thromboplastin time, thrombin time, and fibrinogen tests were evaluated. To define better the mechanism of action of iopiperidol and of the contrast media used for comparison, in vitro tests to study the effects on thrombin activity and on thrombin generation were performed. In addition, the effect of iopiperidol was studied on adenosine diphosphate- and collagen-induced platelet aggregation both in vitro and in vivo after single or repeated intravenous administrations in the rat.

RESULTS

In vitro, iopiperidol showed anticoagulant properties similar or superior to those of the ionic ioxaglate. Iopiperidol also inhibited collagen-induced platelet aggregation statistically significantly more than iodixanol and ioxaglate (P < .05). In vivo, no significant differences between iopiperidol and ioxaglate were observed after single or repeated administrations.

CONCLUSION

The in vitro anticoagulant effect of iopiperidol is similar or even superior to that of ioxaglate; the in vivo effect is similar to that of reference nonionic contrast media.

ATPase activity defects in alloxan-induced diabetic sciatic nerve recovered by ganglioside treatment

ATPase activities were measured in sciatic nerves from rats with alloxan-induced diabetes (ALX-D) of various duration (2 wk, 5 wk, 9 wk, and 6 mo). Our data confirm that sciatic nerve Na+-K+-ATPase abnormalities are present very early in ALX-D rats, similar to results previously described in streptozocin-induced diabetic rats, spontaneously diabetic BB Wistar rats, and ALX-D rabbits. Na+-K+-ATPase activity decreased by 26-47% in ALX-D rats compared with age-matched controls. Ganglioside treatment (10 mg/kg i.p. for 10 or 30 days starting 1 wk after ALX injection) completely impeded the enzyme reduction. The effect observed at the end of either 10 or 30 days of treatment lasted greater than or equal to 1 mo. Chronic diabetic groups treated for 30 days before killing also presented normal ATPase activity at the end of treatment. Therefore, gangliosides are effective on Na+-K+-ATPase even in animals with a longer duration of diabetes. The maintenance of fairly normal ATPase activity by ganglioside treatment could mirror a more general recovery from early metabolic dysfunction and/or late structural abnormalities in diabetic nerve fibers.