Distribution of alpha- and gamma-synucleins in the adult rat brain and their modification by high-dose cocaine treatment

Synucleins have attracted much attention because of their involvement in several neurodegenerative disorders. In a screening for genes differentially expressed after high-dose cocaine exposure, we found gamma-synuclein as a major upregulated candidate in the tegmentum. Overexpression of both alpha- and gamma-synuclein after drug treatment was confirmed by means of microarrays, yielding an increase in the hippocampus, the striatum and the tegmentum (2.65 x, 1.96 x and 3.5 x, respectively, for alpha-synuclein vs. 2.7 x, 1.96 x and 7.16 x for gamma-synuclein), but no change in the nucleus accumbens. Investigation of the distribution of mRNA (by in situ hybridization) and of the proteins (by immunocytochemistry) shows in both cases a clearly distinct pattern of expression for alpha- and gamma-synuclein. alpha-synuclein displays a very characteristic distribution, confined to specific nuclei, whereas gamma-synuclein is more widely expressed throughout the brain. mRNA of both alpha- and gamma-synucleins display a complementary pattern of expression all over the cortex. In contrast to gamma-synuclein, alpha-synuclein is neuronal, being only found in NeuN-expressing cells, and is expressed in the basal ganglia (faintly) and in the substantia nigra compacta where it is highly correlated with tyrosine hydroxylase. Immunocytochemistry shows that gamma-synuclein generally colocalizes with glial fibrillary acidic protein-expressing cells and is abundant in the red nucleus, the substantia nigra reticulata and the anterior commissure, while gamma-synuclein mRNA labels the matrix compartments of the caudate-putamen. The role of synucleins in relation to cocaine-induced plasticity or neurotoxicity is discussed.     

Size-exclusion chromatography purification of high-titer vesicular stomatitis virus G glycoprotein-pseudotyped retrovectors for cell and gene therapy applications

Vesicular stomatitis virus G glycoprotein (VSV-G)-pseudotyped replication-defective retroviral particles are pantropic and amenable to concentration to high titer by ultracentrifugation. These features have allowed development of effective retroviral transduction protocols for stem cells in vitro as well as for tissue engineering in vivo. However, retroparticle ultracentrifugation protocols will also copellet cellular and subcellular debris released from retroviral producer cell lines during vector manufacture. We have analyzed concentrated vector preparations by chromatography and have found that a significant amount of genomic DNA released from producer cells coconcentrates with retroviral particles. In an effort to generate high-purity retroparticle preparations, devoid of subcellular contaminants and contaminating genomic DNA, we have developed a process using size-exclusion chromatography combined with host cell nucleic acid digestion and concentration by ultrafiltration. The procedure allowed for a final recovery of 19 +/- 0.4% infectious viral particles from unfractionated starting material, with an average retroparticle concentration of 7.7 x 10(7) +/- 1.5 x 10(6)/ml. The intact virus is of high purity, >90% as determined by anion-exchange high-performance liquid chromatography. Retroparticle structure appeared intact as determined by negative stain electron microscopy and purified virus was functional and allowed for efficient transduction of primary human bone marrow stromal cells in vitro. In conclusion, we have developed a VSV-G retrovector purification process that can be applied to large-scale retroviral production ideal for cell and gene therapy applications.     

Association between HLA-A/-B antigens and -DRB1 alleles and nasopharyngeal carcinoma in Tunisia

Using serologic and molecular methods, 45 nasopharyngeal carcinoma (NPC) patients were typed for HLA class I and class II and were compared to 100 unrelated normal Tunisians. Our results showed that the antigen frequency of HLA-B13 and allelic frequencies of DRB1*03, DRB1*15 were significantly higher in the NPC patients than in the control group (15.5 vs. 4; 26.4 vs. 11.5, and 14.4 vs. 6.5%, respectively) probably indicating a positive association with NPC. Moreover, we observed that HLA-A23 was absent in our NPC sample and was present in 18% of normal controls, and HLA-DRB1*11 was less frequent among the patients compared to the controls (5.5 vs. 14%) suggesting a protective effect of this association with NPC.     

Epidemiology and development of macular edema in the diabetic

Macular edema is the first cause of blindness in diabetics. Macular edema is defined by macular thickening or deposits of hard exudates. On 1000 diabetics examined over 2 years, 60 patients had a macular edema of which we retained 38 cases(54 eyes). All the patients had an ophthalmologic examination with a retinal angiography. Laser photocoagulation with green Argon laser was instituted in 50 eyes. 63% had background rethinopathy. Total or partial regression of the edema happened in 84.4%. Laser photocoagulation decrease by the half vision loss risk. Interest of early detection and treatment to decrease blindness incidence of macular edema in diabetics.     

Antidyskinetic effect of JL-18, a clozapine analog, in parkinsonian monkeys

Clozapine reduces L-3,4-dihydroxyphenylalanine (L-Dopa)-induced dyskinesias in parkinsonian patients. To test if the antidyskinetic effect of clozapine is related to antagonism at the dopamine D(4) receptor, we investigated the effect of 8-methyl-6-(4-methyl-1-piperazinyl)-11H-pyrido[2,3-b][1, 4]benzodiazepine (JL-18), a structural analog of clozapine which is more selective for this receptor. Four 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine (MPTP)-treated cynomolgus monkeys with a stable parkinsonian syndrome and reproducible dyskinesias to L-Dopa were used in this study. They were injected subcutaneously (s.c.) with L-Dopa methyl ester (125 mg per animal) plus benserazide (50 mg per animal; L-Dopa/benserazide) alone or in combination with JL-18 (at the doses of 0.1, 0.3, or 0.9 mg/kg, s.c.). Subcutaneous injection of sterile saline was used as control. L-Dopa/benserazide increased locomotion and improved parkinsonism but also induced dyskinesias. Co-administration of JL-18, at low doses (0.1, 0.3 mg/kg) with L-Dopa/benserazide, produced a dose-dependent reduction in L-Dopa-induced dyskinesias without a parallel return to parkinsonism. The present results suggest that novel selective dopamine D(4) receptor antagonists may represent a useful tool to reduce L-Dopa-induced dyskinesias.     

New trends in the management of head and neck cancers

Head and neck cancers affect more than half million person a year worldwide. More than 40% have an advanced stage at diagnosis. The incidence in Lebanon according to the statistics of the Ministry of Public Health was 268 new cases in 2007. The tumors and their treatment modalities have an important impact on the quality of life because they influence communication, breathing and4 swallowing. Treatment modalities are evolving to more conservative approaches for better functional results without impeding survival. We present in this review the state of the art of the management of head and neck cancer in 2011 with emphasis on the most recent advances in the assessment, treatment and follow-up.     

Microparticles from apoptotic monocytes enhance nitrosative stress in human endothelial cells

Microparticles are membrane vesicles with procoagulant and proinflammatory properties released during cell activation or apoptosis. Microparticles from monocytes have been implicated in atherosclerosis and vascular inflammation, but their direct effects on endothelial cells are not completely elucidated. The present study was designed to dissect the signaling pathways of monocytic microparticles in endothelial cells with respect to both NO pathway and reactive oxygen species. Microparticles were produced by treatment of human monocytic cell line THP-1 with the apoptotic agent VP-16. Human endothelial cells were treated with monocytic microparticles and then, we studied their effects on nitrosative and oxidative stresses. Incubation of human endothelial cells with microparticles enhanced the production of NO without affecting superoxide anions generation. Microparticles did not affect endothelial NO synthase expression and its phosphorylation. Interestingly, microparticles decreased caveolin-1 expression and increased its phosphorylation. Inhibition of PI-3-kinase or MEK1/2 reversed the effects of microparticles on caveolin-1 expression but not its phosphorylation. Moreover, microparticles increased nitration of several proteins, reflecting peroxynitrite production, which was prevented by blockade of PI-3-kinase pathway. In summary, monocyte microparticles active multiple pathways related to nitrosative stress in endothelial cells including both PI-3-kinase and ERK1/2 in the regulation of caveolin-1 expression. These data underscore the pleiotropic effect of microparticles on endothelial cells and suggest that they probably play a critical role on vascular function.     

Spontaneous rupture and hemorrhage of hepatic focal nodular hyperplasia in lobus caudatus

In general, focal nodular hyperplasia lesions of the liver have a benign natural course; the majority of cases remain asymptomatic and complications are rare. We report a case of spontaneous rupture and hemorrhage of focal nodular hyperplasia, which is extremely rare in the literature. A 35-year-old woman was admitted with severe upper abdominal pain and unstable hemodynamic status. No major abdominal trauma was noted. Radiology findings suggested a diffuse hemoperitoneum. Emergent surgical exploration showed a hemoperitoneum due to the rupture of a hepatic mass lesion in segment I. Suture of the rupture was undertaken with success. After this lifesaving emergent surgery, further investigations, including ultrasound, contrast-enhanced computed tomography, and magnetic resonance imaging, were undertaken, and a 5.7 × 9.8 × 6.4-cm focal nodular hyperplasia lesion was identified in segment I. Two weeks after the first surgical hemostasis, surgical removal of segment I, including the mass, was performed. The postoperative course was uneventful. Pathological evaluation confirmed the nature of focal nodular hyperplasia. The patient remains asymptomatic without evidence of recurrence 3 years and 6 months after surgery. To our knowledge, this is the firstcase of spontaneous rupture and hemorrhage of focal nodular hyperplasia that needed two consecutive surgical operations.     

Transfusion-related acute lung injury (TRALI) during remission induction course of acute myeloid leukemia: A possible role for all-transretinoic-acid (ATRA)?

Transfusion-related acute lung injury (TRALI) is a clinical syndrome characterized by sudden onset of respiratory distress due to pulmonary edema during or following transfusion. Two proposed pathophysiologic mechanisms for TRALI were proposed: the antibody hypothesis and the two-event hypothesis. The two-event hypothesis postulates that a pathway to neutrophil activation and aggregation can occur without leukocyte antibodies. We report a case of TRALI occurring during remission induction course of acute myeloid leukemia in a 27-year-old woman who received All-transretinoic-acid (ATRA). We postulate that ATRA may have played a role in this life-threatening complication by priming neutrophil and enhancing their adherence and their activation in the pulmonary endothelium. TRALI improved with non-invasive ventilation support and use of high dose corticosteroids.