B-factory Physics from Effective Supersymmetry

We discuss how to extract non-Standard Model effects from B-factory phenomenology. We then analyze the prospects for uncovering evidence for Effective Supersymmetry, a class of supersymmetric models which naturally suppress flavor changing neutral currents and electric dipole moments without squark universality or small CP violating phases, in experiments at BaBar, BELLE, HERA-B, CDF/D0 and LHC-B.Comment: 5 pages, 2 figures, revtex, eps

MR diffusion tensor imaging and fiber tracking in 5 spinal cord astrocytomas.

International audienceSpinal cord astrocytomas are rare neoplasms that can result in alteration of the spinal cord structural integrity, which can be assessed by using diffusion tensor imaging methods. Our objective was to visualize the deformation of the posterior spinal cord lemniscal and corticospinal tracts in 5 patients with low-grade astrocytomas compared with 10 healthy volunteers by using 3D fiber-tracking reconstructions

Comparison of the pharmacological properties of GK11 and MK801, two NMDA receptor antagonists: towards an explanation for the lack of intrinsic neurotoxicity of GK11.

International audienceOver-stimulation of NMDA receptors (NMDARs) is involved in many neurodegenerative disorders. Thus, developing safe NMDAR antagonists is of high therapeutic interest. GK11 is a high affinity uncompetitive NMDAR antagonist with low intrinsic neurotoxicity, shown to be promising for treating CNS trauma. In the present study, we investigated the molecular basis of its interaction with NMDARs and compared this with the reference molecule MK801. We show, on primary cultures of hippocampal neurons, that GK11 exhibits neuroprotection properties similar to those of MK801, but in contrast with MK801, GK11 is not toxic to neurons. Using patch-clamp techniques, we also show that on NR1a/NR2B receptors, GK11 totally blocks the NMDA-mediated currents but has a six-fold lower IC(50) than MK801. On NR1a/NR2A receptors, it displays similar affinity but fails to totally prevent the currents. As NR2A is preferentially localized at synapses and NR2B at extrasynaptic sites, we investigated, using calcium imaging and patch-clamp approaches, the effects of GK11 on either synaptic or extrasynaptic NMDA-mediated responses. Here we demonstrate that in contrast with MK801, GK11 better preserve the synaptic NMDA-mediated currents. Our study supports that the selectivity of GK11 for NR2B containing receptors accounts contributes, at least partially, for its safer pharmacological profile

High-performance liquid chromatography analysis of circulating insulins distinguishes between endogenous insulin production (a potential pitfall with streptozotocin diabetic rats) and islet xenograft function

Porcine islets of Langerhans were microencapsulated according to the alginate-polylysine procedure, and implanted into the peritoneal cavity of 15 streptozotocin-induced (70 mg/kg) diabetic rats (6000 microencapsulated islets per rat). In four animals, a sustained decrease in plasma glucose level below 8.3 mmol/l was observed for up to nine months. However, it was possible to recover microcapsules from the peritoneal cavity of only one rat, and they were found to be damaged and containing no detectable tissue. When insulin in the plasma of three of these animals was analysed by reversed phase high-performance liquid chromatography, only rat insulins I and II, but not porcine insulin was detectable, indicating unambiguously that at the time of analysis, the correction of diabetes in these animals was due to the function of the recipient's own pancreas rather than the continued, long-term, function of the implanted porcine islets. These data confirm that in this model of diabetes, function of the host pancreas can resume following islet transplantation, leading in turn to the potential for a major bias in the interpretation of the data. In the case of an islet xenograft, when the donor's and recipient's insulins can be separated by high-performance liquid chromatography, this non-invasive analytical method should prove useful for identifying the source of insulin in the circulation, and thus the relative functional status of the endogenous and transplanted islets