Existence of muscarinic acetylcholine receptor (mAChR) and fibroblast growth factor receptor (FGFR) heteroreceptor complexes and their enhancement of neurite outgrowth in neural hippocampal cultures.

BACKGROUND: Recently, it was demonstrated that G-protein-coupled receptors (GPCRs) can transactivate tyrosine kinase receptors in absence of their ligands. In this work, driven by the observation that mAChRs and fibroblast growth factor receptors (FGFRs) share signalling pathways and regulation of brain functions, it was decided to explore whether mAChRs activation may transactivate FGFRs and, if so, to characterize the related trophic effects in cultured hippocampal neurons. METHODS: Oxotremorine-M transactivation of FGFRs and related trophic effects were tested in primary hippocampal neurons. Western blotting and in situ proximity ligation assay (PLA) were used to detect FGFR phosphorylation (pFGFR) levels and M1R-FGFR1 heteroreceptor complexes, respectively. RESULTS: Oxotremorine-M, a non-selective mAChRs agonist, was able to transactivate FGFR and this transactivation was blocked by Src inhibitors. Oxotremorine-M treatment produced a significant increase in the primary neurite outgrowth that was blocked by pre-treatment with the pFGFR inhibitor SU5402 and Src inhibitors. This trophic effect was almost similar to that induced by fibroblast growth factor-2 (FGF-2). By using atropine as nonselective mAChRs or pirenzepine as selective antagonist for M1 receptor (M1R) we could show that mAChRs are involved in modulating the pFGFRs. Using PLA, M1R-FGFR1 heteroreceptor complexes were identified in the hippocampus and cerebral cortex. CONCLUSION: The current findings, by showing functional mAChR-FGFR interactions, will contribute to advance the understanding of the mechanisms involved in the actions of cholinergic drugs on neuronal plasticity. GENERAL SIGNIFICANT: Data may help to develop novel therapeutic strategies not only for neurodegenerative diseases but also for depression-induced atrophy of hippocampal neurons.

MRI in the assessment of prolapsed pedunculated submucous leiomyomas: two case reports.

Uterine leiomyomas are the most common benign gynecological tumors affecting 20-30% of women in reproductive age. Despite their benignity, in some cases several symptoms may require surgical intervention. Submucosal leiomyomas are less frequent (5-10%), but are usually symptomatic. Approximately 2.5% of the myomas are pedunculated and can protrude in the cervical canal. Symptomatic leiomyomas can be treated either by hysterectomy or myomectomy, and these procedures can be performed with several techniques. Whenever possible, hysteroscopic myomectomy is better because it has many advantages, as it also preserves future fertility. Two interesting cases of prolapsed pedunculated submucous leiomyomas are reported in order to prove that magnetic resonance imaging (MRI) is essential to choose the most appropriate treatment and to perform an adequate presurgical planning, which must be based on an overall assessment of the leiomyoma's characteristics (number, location, size and presence or absence of a stalk) and the patient's characteristics.

The FGF-2/FGFRs neurotrophic system promotes neurogenesis in the adult brain.

Neurogenesis occurs in two regions of the adult brain, namely, the subventricular zone (SVZ) throughout the wall of the lateral ventricle and the subgranular zone (SGZ) of the dentate gyrus (DG) in hippocampal formation. Adult neurogenesis requires several neurotrophic factors to sustain and regulate the proliferation and differentiation of the adult stem cell population. In the present review, we examine the cellular and functional aspects of a trophic system mediated by fibroblast growth factor-2 (FGF-2) and its receptors (FGFRs) related to neurogenesis in the SVZ and SGZ of the adult rat brain. In the SVZ, FGF-2 is expressed in GFAP-positive cells of SVZ but is not present in proliferating precursor cells, which instead express FGFR-1 and FGFR-2, but not FGFR-3 mRNA, although expressed in the SVZ, and FGFR-4. Therefore, it seems that in the SVZ FGF-2 may be released by GFAP-positive cells, different from the precursor cell lineage, and via volume transmission it reaches the proliferating precursor cells. FGFR-1 mRNA is also expressed in the SGZ and is localized in BrdU-labeled precursor cells, whereas FGFR-2 and FGFR-3 mRNA, although expressed in the SGZ, are not located within proliferating precursor cells. An aged-related decline of proliferating precursor cells in the SVZ and DG of old rats has been well documented, and there is the suggestion that in part it could be the consequence of alterations in growth factor expression levels. Thus, the old precursors may respond to growth factors, suggesting that during aging the basic components for neuronal precursor cell proliferation are retained and the capacity to increase neurogenesis after appropriate stimulation is still preserved. In conclusion, the trophic system mediated by FGF-2 and its receptors contributes to create an important micro-environmental niche that promotes neurogenesis in the adult and aged brain.

A Case of Primary T-Cell Central Nervous System Lymphoma: MR Imaging and MR Spectroscopy Assessment.

Primary central nervous system lymphomas (PCNSLs) are mainly B-cells lymphomas. A risk factor for the development of PCNSL is immunodeficiency, which includes congenital disorders, iatrogenic immunosuppression, and HIV. The clinical course is rapidly fatal; these patients usually present signs of increased intracranial pressure, nausea, papilledema, vomiting, and neurological and neuropsychiatric symptoms. PCNSL may have a characteristic appearance on CT and MR imaging. DWI sequences and MR spectroscopy may help to differentiate CNS lymphomas from other brain lesions. In this paper, we report a case of a 23-year-old man with T-primary central nervous system lymphoma presenting with a mass in the right frontotemporal lobe. We describe clinical, CT, and MRI findings. Diagnosis was confirmed by stereotactic biopsy of the lesion.

Group II metabotropic glutamate receptor activation by agonist LY379268 treatment increases the expression of brain derived neurotrophic factor in the mouse brain.

A number of in vitro and in vivo studies using selective agonists have indicated a neuroprotective role for group-II metabotropic glutamate (mGlu2/3) receptors in various models of neuronal injury. Although an interplay among neurotrophic factors and mGlu2/3 receptors signalling system has been suggested as possible mechanism involved on neuroprotection, at present poor information are available concerning the in vivo regulation by mGlu2/3 receptors activation of specific neurotrophic factors. By using in situ hybridization and western blotting methods the aim of present study was to analyse the potential regulatory role of selective mGluR2/3 agonist LY379268 treatment on brain derived neurotrophic factor (BDNF) expression in the mouse brain. The treatment with LY379268 evidenced a significant upregulation of BDNF mRNA levels in the cerebral cortex and in the hippocampal formation with a peak at 3 h from treatment and its disappearance already at 6 h from treatment. An analysis of dose-effect curve revealed that LY379268 may significantly enhance BDNF mRNA expression already at dose of 0.250 mg/kg b.w. The upregulation of BDNF mRNA expression was followed by a significant increase of BDNF protein levels at 24 h from LY379268 treatment. These effects of LY379268 treatment on BDNF expression were restricted to neuronal cells and were blocked by the new selective mGlu2/3 receptor antagonist LY341495, suggesting a receptor specificity. Taken together these findings suggest that several previous observed neuroprotective and trophic actions of mGluR2/3 agonists treatment may be mediated, at least in the cerebral cortex and hippocampal formation, by upregulation of BDNF expression.

Abuse of combinations of carisoprodol and tramadol.

Neither carisoprodol (Soma) nor tramadol (Ultram) is a controlled substance at the federal level. However, evidence indicates that these medications may have abuse potential, particularly in patients with a history of substance abuse. We report three cases in which a combination of carisoprodol and tramadol was used illicitly to obtain psychotropic effects. Carisoprodol or tramadol should be prescribed with caution for patients at risk for substance abuse, and extreme caution should be used when prescribing both drugs simultaneously for any patient.