Quantitative analysis of hindlimbs locomotion kinematics in spinalized rats treated with Tamoxifen plus treadmill exercise.

Locomotion recovery after a spinal cord injury (SCI) includes axon regeneration, myelin preservation and increased plasticity in propriospinal and descending spinal circuitries. The combined effects of tamoxifen and exercise after a SCI were analyzed in this study to determine whether the combination of both treatments induces the best outcome in locomotion recovery. In this study, the penetrating injury was provoked by a sharp projectile that penetrates through right dorsal and ventral portions of the T13-L1 spinal segments, affecting propriospinal and descending/ascending tracts. Intraperitoneal application of Tamoxifen and a treadmill exercise protocol, as rehabilitation therapies, separately or combined, were used. To evaluate the functional recovery, angular patterns of the hip, knee and ankle joints as well as the leg pendulum-like movement (PLM) were measured during the unrestricted gait of treated and untreated (UT) animals, previously and after the traumatic injury (15 and 30days post-injury (dpi)). A pattern (curve) comparison analysis was made by using a locally designed Matlab script that determines the Frechet dissimilarity. The SCI magnitude was assessed by qualitative and quantitative histological analysis of the injury site 30days after SCI. Our results showed that all treated groups had an improvement in hindlimbs kinematics compared to the UT group, which showed a poor gait locomotion recovery throughout the rehabilitation period. The group with the combined treatment (tamoxifen+exercise (TE)) presented the best outcome. In conclusion, tamoxifen and treadmill exercise treatments are complementary therapies for the functional recovery of gait locomotion in hemi-spinalized rats.

The hippocampus participates in the control of locomotion speed.

The hippocampus role in sensory-motor integration remains unclear. In these experiments we study its function in the locomotor control. To establish the connection between the hippocampus and the locomotor system, electrical stimulation in the CA1 region was applied and EMG recordings were obtained. We also evaluated the hindlimbs and forelimbs kinematic patterns in rats with a penetrating injury (PI) in the hippocampus as well as in a cortex-injured group (CI), which served as control. After the PI, tamoxifen a selective estrogen receptor modulator (SERM) that has been described as a neuroprotector and antiinflammatory drug, or vehicle was administered. Electrical stimulation in the hippocampus produces muscle contractions in the contralateral triceps, when 6 Hz or 8 Hz pulse trains were applied. The penetrating injury in the hippocampus reduced the EMG amplitude after the electrical stimulation. At 7 DPI (days post-injury) we observed an increase in the strides speed in all four limbs of the non-treated group, decreasing the correlation percentage of the studied joints. After 15 DPI the strides speed in the non-treated returned to normal. These changes did not occur in the tamoxifen group nor in cortex-injured group. After 30 days, the nontreated group presented a reduction in the number of pyramidal cell layer neurons at the injury site, in comparison to the tam-treated group. The loss of neurons, may cause the interruption of the trisynaptic circuit and changes in the locomotion speed. Tamoxifen preserves the pyramidal neurons after the injury, probably resulting in the strides speed recovery.

Aromatase and estrogen receptor alpha mRNA expression as prognostic biomarkers in patients with astrocytomas.

Estrogens are oncogenic hormones at a high level in breast, prostate, endometrial and lung cancer. Estrogens are synthesized by aromatase which has been used as a biomarker both in breast and lung cancer. Estrogen biological activities are executed by their classic receptors (ERα and ERß). ERα has been described as a cancer promoter and ERß, as a possible tumor suppressor. Both receptors are present at low levels in primary multiforme glioblastoma (GBM). The GBM frequency is 50 % higher in men than in women. The GBM patient survival period ranges from 7 to 18 months. The purpose of this pilot study was to evaluate aromatase and estrogen receptor expression, as well as 17ß-estradiol concentration in astrocytoma patients biopsies to obtain a prognosis biomarker for these patients. We analyzed 36 biopsies of astrocytoma patients with a different grade (I-IV) of malignity. Aromatase and estrogen receptor mRNA expression were analyzed by semiquantitative RT-PCR, and the E2 levels, by ELISA. E2 concentration was higher in GBM, compared to grade II or III astrocytomas. The number of cells immunoreactive to aromatase and estrogen receptors decreased as the grade of tumor malignity increased. Aromatase mRNA expression was present in all biopsies, regardless of malignity grade or patient age or gender. The highest expression of aromatase mRNA in GBM patients was associated to the worst survival prognostic (6.28 months). In contrast lowest expression of ERα mRNA in astrocytoma patients had a worst prognosis. In conclusion, aromatase and ERα expression could be used as prognosis biomarkers for astrocytoma patients.

Tamoxifen favoured the rat sensorial cortex regeneration after a penetrating brain injury.

A penetrating brain injury produces a glial scar formed by astrocytes, oligodendrocytes, microglia and NG2 cells. Glial scar is a barrier preventing the extent of damage but it has deleterious effects in the regeneration of the axons. Estradiol and tamoxifen reduce gliosis and have neuroprotective effects in the hippocampus and the spinal cord. We evaluated the proliferation of glia and the electrocorticogram in the sensorial cortex in a brain injury model. At seven days post-injury, estradiol, tamoxifen and estradiol plus tamoxifen reduced the number of resident and proliferative NG2 and reactive astrocyte vimentin+ cells. Estradiol and tamoxifen effects on NG2 cells could be produced by the classical oestrogen receptors found in these cells. The glial scar was also reduced by tamoxifen. At thirty days post-injury, the amount of resident and proliferative astrocytes increased significantly, except in the estradiol plus tamoxifen group, whilst the oligodendrocytes proliferation in the glial scar was reduced in treated animals. Tamoxifen promotes the survival of FOX-3+ neurons in the injured area and a recovery in the amplitude of electrocorticogram waves. At thirty days, estradiol did not favour the survival of neurons but produced a greater number of reactive astrocytes. In contrast, the number of oligodendrocytes was reduced. Tamoxifen could favour brain repair promoting neuron survival and adjusting glial cell number. It seems to recover adequate neural communication.

Electrophysiological and morphological alterations in peripheral nerves by the pig paramyxovirus of blue eye disease in neonatal pigs.

The pig paramyxovirus of blue eye disease (PPBED) produces central nervous system (CNS) damage leading to death in piglets. However, when PPBED was injected into the muscle and came into contact with hind limb peripheral nerves and was transported to the CNS, it did not cause death and could be a mechanism by which to induce protection. This study analyses whether PPBED causes electrophysiological and morphological alterations in infected hind limb peripheral nerves. It also studies, whether PPBED induces the onset of haemagglutination inhibitory antibodies (HIA) when it is transported to the spinal cord after medial gastrocnemius (MG) intramuscular injection. PPBED was detected by an immunohistochemical method and nerve morphology was studied using electron microscopy. The physiological status of the nerve was evaluated with electrophysiological techniques. The electrical threshold of the infected MG nerve increased four- or five fold compared to that in the ipsilateral lateral gastrocnemius or in the MG nerve on the control side. The infected nerve fibres underwent myelin sheet disarrangement and their internal fibre diameter decreased. PPBED induced the onset of HIA.

Pig paramyxovirus of the blue eye disease binding to a 116 kDa glycoprotein expressed in pig neuronal membranes.

UNLABELLED: Pig paramyxovirus of the blue eye disease (PPBED) is a novel member of the paramyxoviridac family which infects pigs. In neonatal pigs it causes neurological damage, whereas in adult pigs it affects the reproductive function. As PPBED damages the new-born pig central nervous system (CNS), it is important to study whether PPBED binds to the membrane proteins of all brain tissue, or selectively binds to neuronal tissue of the brain stem, olfactory bulb, hippocampus, cerebellum, frontal, temporal and parietal brain cortex. It is also important to establish whether it also infects neurones obtained from new-born, 60-day-old and adult pigs, and the role of carbohydrate residues in virus binding. The effect on virus binding of polyclonal antibodies against viral envelope proteins was also studied. Binding studies were performed using dot blot and virus overlay protein binding assays. PPBED was able to bind to membrane proteins from all brain regions, particularly to a protein band of approximately 116 kDa. Neuraminidase treatment of neuronal membrane proteins decreased virus binding; subsequent treatments with beta-galactosidase and manosidase did not increase virus binding inhibition. N-glycosidase F and trypsin also decreased virus binding, but not the O-glycanase. Antibodies against viral haemagglutinin-neuraminidase blocked virus binding more efficiently than antibodies against viral fusion protein. IN CONCLUSION: (1) PPBFD is able to bind to pig neurones of all brain regions studied and at all ages analysed; (2) a 116 kDa membrane protein containing sialic acid residues with an N-linked oligosaccharide chain was specifically recognized; (3) PPBED haemagglutinin-neuraminidase protein seems to play a central role in neural receptor recognition.