Study of the glial cytoarchitecture of the developing olfactory bulb of a shark using immunochemical markers of radial glia

During development of the olfactory bulb (OB), glial cells play key roles in axonal guiding/targeting, glomerular formation and synaptic plasticity. Studies in mammals have shown that radial glial cells and peripheral olfactory glia (olfactory ensheathing cells, OECs) are involved in the development of the OB. Most studies about the OB glia were carried out in mammals, but data are lacking in most non-mammalian vertebrates. In the present work, we studied the development of the OB glial system in the cartilaginous fish Scyliorhinus canicula (catshark) using antibodies against glial markers, such as glial fibrillary acidic protein (GFAP), brain lipid-binding protein (BLBP), and glutamine synthase (GS). These glial markers were expressed in cells with radial morphology lining the OB ventricle of embryos and this expression continues in ependymal cells (tanycytes) in early juveniles. Astrocyte-like cells were also observed in the granular layer and surrounding glomeruli. Numerous GS-positive cells were present in the primary olfactory pathway of embryos. In the developmental stages analysed, the olfactory nerve layer and the glomerular layer were the regions with higher GFAP, BLBP and GS immuno-reactivity. In addition, numerous BLBP-expressing cells (a marker of mammalian OECs) showing proliferative activity were present in the olfactory nerve layer. Our findings suggest that glial cells of peripheral and central origin coexist in the OB of catshark embryos and early juveniles. These results open the path for future studies about the differential roles of glial cells in the catshark OB during embryonic development and in adulthood.

Effect of multisegmental electrical stimulation in combination with proprioceptive stimulation of the spinal cord on changes in reflex excitability of motor neurons

The study involved 15 men with movement disorders of central origin. We used percutaneous electrical stimulation of the spinal cord with the application of electrodes in the projection of the lumbar thickening, proprioceptive stimulation, and their combination. The data obtained showed the effectiveness of the combined course of percutaneous electrical stimulation of the spinal cord and proprioceptive stimulation on changes in the excitability of spinal locomotor neural networks. Key words: electrical stimulation, spinal cord, proprioceptive stimulation, rehabilitation, motor neuron.

Hypothalamic Hamartoma Revealed by Precocious Puberty in Girls: About A New Case

Precocious puberty is a multifactorial process whose diagnosis is based, first of all, on the clinic but also on the realization of the bone age, the pelvic ultrasound and the cerebral IRM. Moreover, the GnRH test constitutes the cornerstone to highlight a premature activation of the Hypothalamo-hypophyseal axis. We report the case of a 3-year-old girl admitted for exploration of precocious puberty. The central origin was confirmed by a GnRH test with a peak reaching 45 mIU/L. A hypothalamohypophyseal MRI was performed, showing a mass consistent with a hypothalamic hamartoma. Treatment with GnRH analogues is the treatment of choice for central precocious puberty.

Hypothalamic GPCR Signaling Pathways in Cardiometabolic Control

Obesity is commonly associated with sympathetic overdrive, which is one of the major risk factors for the development of cardiovascular diseases, such as hypertension and heart failure. Over the past few decades, there has been a growing understanding of molecular mechanisms underlying obesity development with central origin; however, the relative contribution of these molecular changes to the regulation of cardiovascular function remains vague. A variety of G-protein coupled receptors (GPCRs) and their downstream signaling pathways activated in distinct hypothalamic neurons by different metabolic hormones, neuropeptides and monoamine neurotransmitters are crucial not only for the regulation of appetite and metabolic homeostasis but also for the sympathetic control of cardiovascular function. In this review, we will highlight the main GPCRs and associated hypothalamic nuclei that are important for both metabolic homeostasis and cardiovascular function. The potential downstream molecular mediators of these GPCRs will also be discussed.

Phytophthora alni species complex (alder Phytophthora).

The alder Phytophthora species complex of oomycetes encompasses the hybrid P. ×alni and its two parental species, P. uniformis and P. × multiformis (Brasier et al., 1999; Husson et al., 2015). It emerged in the early 1990s and is associated with severe decline of alder trees on river banks of Europe. The main pathogen involved, P. ×alni, was previously unreported. Its pattern of occurrence suggests an invasive species, but one that arose from several hybridization events in different places rather than spreading from a central origin. The population structure of P. uniformis, one of the parental species, suggests that it is introduced in Europe and native in North America (Aguayo et al., 2013); the origin of the second parent, P. × multiformis, remains unknown. Long-range spread is mainly through planting of infected nursery stock, followed by downstream spread in river water by motile zoospores. The pathogen was on the EPPO alert list from 1996 to 2001.

Phytophthora alni species complex (alder phytophthora).

The alder Phytophthora species complex of oomycetes encompasses the hybrid P. ×alni and its two parental species, P. uniformis and P. ×multiformis (Brasier et al., 1999; Husson et al., 2015). It emerged in the early 1990s and is associated with severe decline of alder trees on river banks of Europe. The main pathogen involved, P. ×alni, was previously unreported. Its pattern of occurrence suggests an invasive species, but one that arose from several hybridization events in different places rather than spreading from a central origin. The population structure of P. uniformis, one of the parental species, suggests that it is introduced in Europe and native in North America (Aguayo et al., 2013); the origin of the second parent, P. ×multiformis, remains unknown. Long-range spread is mainly through planting of infected nursery stock, followed by downstream spread in river water by motile zoospores. The pathogen was on the EPPO alert list from 1996 to 2001.

Thrombotic Thrombocytopenic Purpura Without Schistocytes: Beware of Misdiagnosis

A 43-year old woman was admitted for acute unusual headache, vertigo and left upper limb weakness. She had been complaining of asthenia for the past few weeks. Past medical history included uterine cervix cancer treated with conisation and two pregnancies without serious complications. No allergy or recent drug introduction was noted. After ruling out current pregnancy, Magnetic Resonance Imaging (MRI) was immediately performed and showed recent ischemic strokes in multiple territories. Doppler ultrasound imaging showed no carotid or vertebral arteries lesion. Electrocardiogram showed no ST elevation or atrial fibrillation and echocardiography did not reveal embolic lesion or patent foramen ovale. Blood cell count showed thrombocytopenia at 17 x 109/L (confirmed in citrate tube) and hyperleukocytosis at 18 x 109/L without anemia (hemoglobin at 12,9 g/dL). Basic metabolic profile, kidney and liver function tests were normal. Hemolysis signs were present: reticulocytes, total bilirubin, Lactate dehydrogenase (LDH) and haptoglobin levels were at 147 x 109/L, 27,2 μmol/L, 454 U/L and bellow 0.08 g/L respectively. Repeated blood smears showed no schistocytes. A disseminated intravascular coagulation was ruled out (normal APTT and prothrombin time, fibrinogen at 3,6 g/L), as well as autoimmune cytopenia (Coombs test was negative), hyperhomocysteinemia, vitamin deficiencies (B9, B12) and paroxysmal nocturnal hemoglobinuria. Bone marrow examination showed increased megakaryocytes with normal morphology excluding a central origin. Lupus anticoagulant (LA), anticardiolipin (aCL) and anti- β2gp1 antibodies were negative. A thoraco-abdominopelvic scan with contrast showed small renal and splenic infarcts; no suspect tumor was observed.

Neurological examination as an impressive factor in the dizziness assessment

Context: Dizziness or vertigo is a very common clinical manifestation, usually of labyrinthic origin. However, an accurated neurological clinical examination is crucial for the diagnosis of central origin. Case report: D.F.A, 40 years old, female, white, Brazilian. She has been reportining of intense dizziness for a few months and relevant postural instability. She reports two previous hospitalizations, without a closed diagnosis, and is then referred to the specialist. On clinical examination, she had bilateral internuclear ophthalmoparesis and bidirectional nystagmus in her right eye. Requested magnetic resonance imaging (MRI) of the skull suggestive of demyelinating lesions in the wall of the fourth ventricle, pons and, especially, in transition between medulla oblongata and spinal cord, compatible with Neuromyelitis Optica (NMO) with manifestations of trunk syndrome. After pulse therapy, she obtained a good clinical evolution, with the maintenance of sensory deficits as a result of the injury, but with significant improvement in bilateral ophthalmoparesis and balance. Some studies already report brainstem involvement in patients with NMO, describing the presence of brainstem´s signals. Conclusion: In the case in question, therefore, the patient remained for almost two months without an accurate diagnosis, being the neurological examination the crucial factor for the suggestion of a disease of central origin, reporting a case of onset NMO with of brainstem´s signals.