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Dorsal root ganglionectomy for the diagnosis of sensory neuropathies. Surgical technique and results

COLLI, Benedicto Oscar; CARLOTTI JR., Carlos Gilberto; ASSIRATI JR., Joao Alberto; LOPES, Luiza da Silva; MARQUES JR., Wilson; CHIMELLI, Leila; NEDER, Luciano; BARREIRA, Amilton Antunes
Fonte: ELSEVIER SCIENCE INC Publicador: ELSEVIER SCIENCE INC
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
66.57%
Background: Inflammatory diseases stand out among sensory neuronopathies because, in their active phase, they can be treated with immunosuppressive agents. Immunosuppressive therapy may present severe adverse effects and requires previous inflammatory activity confirmation. Sensory neuronopathies are diagnosed based on clinical and EMG findings. Diagnostic confirmation and identification of inflammatory activity are based on sensory ganglion histopathological examination. We describe the surgical technique used for dorsal root ganglionectomy in patients with clinical/EMG diagnosis of sensory neuronopathies. Methods: The sensory ganglion was obtained from 15 patients through a small T7-T8 hemilaminectomy and foraminotomy to expose the C7 root from its origin to the spinal nerve bifurcation. In 6 patients, the dural cuff supposed to contain the ganglion was resected en bloc; and in 9 patients, the ganglion was obtained through a longitudinal incision of the dural cuff and microsurgical dissection from the ventral and dorsal roots and radicular arteries. All ganglia were histopathologically examined. Results: No ganglion was found in the dural cuff in 2 patients submitted to en bloc removal, and the ganglion was removed in all patients who underwent microsurgical dissection. All but 2 patients that had ganglion examination presented a neuronopathy of nerve cell loss...

Rabies virus infection of cultured adult mouse dorsal root ganglion neurons

Castellanos,Jaime; Hurtado,Hernán; Arias,Janeth; Velandia,Alvaro
Fonte: Instituto Oswaldo Cruz, Ministério da Saúde Publicador: Instituto Oswaldo Cruz, Ministério da Saúde
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/1996 Português
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96.36%
An in vitro model of adult dorsal root ganglion neurons infection by rabies virus is described. Viral marked neurotropism is observed, and the percentage and the degree of infection of the neurons is higher than in non neuronal cells, even if neurons are the minority of the cells in the culture. The neuritic tree is also heavily infected by the virus.

Effects of dorsal root ganglion destruction by adriamycin in patients with postherpetic neuralgia

Chun-jing,He; yi-ran,Luo; hao-xiong,Nie
Fonte: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia Publicador: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2012 Português
Relevância na Pesquisa
66.47%
PURPOSE: To investigate the effects of dorsal root ganglion destruction in patients with postherpetic neuralgia (PHN). METHODS: Seventy-two patients with PHN selected were randomly divided into two groups (n=36). Group A was the control group (treated by injection) and group B was the group of dorsal root ganglion destruction by adriamycin. Visual analog scale scores (VAS), SAS, SF-MPQ scores. Clinical effects and therapy safety were evaluated before therapy, one week, three and six months after therapy. Forty-four patients were available for intention-to-treat analysis. RESULTS: The average pain scores on the Likert scale were significantly reduced at each point in group B. Patients in group B reported clinical effectiveness at six months as excellent response, good response, improved but unsatisfactory or unchanged 16, 12 and 8.VAS scores at each time point after the operation were lower than that before operation and in group A, there was significant difference. Patients showed significant improvement in sleep scores in group B. There was significant difference at T2 in group A than T1. There was no significant difference in group A at T3, T4 after the operation than that before operation. Between group comparison: there was significant difference between group A and group B at each time point after the operation. CONCLUSIONS: Dorsal root ganglion destruction by adriamycin under guidance of C-arm perspective...

Developing dorsal root ganglion neurons require trophic support from their central processes: evidence for a role of retrogradely transported nerve growth factor from the central nervous system to the periphery.

Yip, H K; Johnson, E M
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1984 Português
Relevância na Pesquisa
66.61%
Injury to the peripheral processes produces a profound cell loss (40-50%) in the dorsal root ganglion of newborn rats. Although division of central processes produces little or no cellular change in sensory ganglion of adult animals, no information has been available on the effect of dorsal root section in developing dorsal root ganglion. We show that 6 days after dorsal rhizotomy on newborn rats, there is a 50% decrease in neuronal number in L5 dorsal root ganglion. A combined central and peripheral lesion of the sensory process results in a greater decrease in neuronal number (70%). Both of these effects can be prevented by the concomitant treatment with nerve growth factor. We also demonstrate that 125I-Ia-labeled nerve growth factor is retrogradely transported with high selectivity from the spinal cord to the dorsal root ganglion via the dorsal roots. The results indicate that trophic support for developing sensory neurons is provided through the central processes. This is presumably due to the uptake and retrograde transport of a trophic factor by the terminals of the central processes. The data suggest that nerve growth factor may be the trophic factor.

Cisplatin-induced apoptosis in rat dorsal root ganglion neurons is associated with attempted entry into the cell cycle.

Gill, J S; Windebank, A J
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 15/06/1998 Português
Relevância na Pesquisa
66.47%
Platinum compounds induce apoptosis in malignant cells and are used extensively in the treatment of cancer. Total dose is limited by development of a sensory neuropathy. We now demonstrate that when rats are administered cisplatin (2 mg/kg i.p. for 5 d), primary sensory neurons in the dorsal root ganglion die by apoptosis. This was reproduced by exposure of dorsal root ganglion neurons and PC12 cells to cisplatin (3 microg/ml) in vitro. Apoptosis was confirmed by electron microscopy, DNA laddering, and inhibition by the caspase inhibitor z-VAD.fmk (100 microM). Cell death in vitro was preceded by upregulation of cyclin D1, cdk4, and increased phosphorylation of retinoblastoma protein; all are indicators of cell cycle advancement. The level of p16(INK4a), an endogenous inhibitor of the cyclin D1/cdk4 complex decreased. Exposure of PC12 cells and dorsal root ganglion neurons to increased levels of nerve growth factor (100 ng/ ml) prevented both apoptosis and upregulation of the cell cycle markers. Cancer cells without nerve growth factor receptors (gp140TrkA) were not protected by the neurotrophin. This indicated that cisplatin may kill cancer cells and neurons by a similar mechanism. In postmitotic neurons, this involves an attempt to re-enter the cell cycle resulting in apoptosis which is specifically prevented by nerve growth factor.

Calcium currents in aged rat dorsal root ganglion neurones.

Kostyuk, P; Pronchuk, N; Savchenko, A; Verkhratsky, A
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /02/1993 Português
Relevância na Pesquisa
66.47%
1. The whole-cell voltage clamp technique was used to record calcium currents in the somatic membrane of rat cultured dorsal root ganglion neurones. 2. Neurones were enzymatically isolated from animals of three age groups (neonatal, 2-7 days; adult, 7 months; and old, 30 months) and maintained in primary culture 3-14 days. 3. The neurones isolated from neonatal and old rats showed two distinct types of Ca2+ currents, a low-threshold transient current and a high-threshold sustained current, whereas neurones from old rats showed only a high-threshold calcium current. 4. The density of the high-threshold calcium current was 28.4 +/- 6.3 pA/pF (mean +/- S.E.M., n = 54) in neonatal, 39.1 +/- 7.2 pA/pF (n = 62) in adult and 11.0 +/- 4.6 pA/pF (n = 64) in old dorsal root ganglion neurones. 5. We found no difference in elementary high-threshold Ca2+ current characteristics in neurones from different age groups. The single-channel conductance was (with 60 mM Ca2+ in the recording pipette) 16.0 +/- 2.7 pS (mean +/- S.E.M., n = 9) in neonatal, 16.2 +/- 1.7 pS (n = 11) in adult and 16.4 +/- 1.2 pS (n = 12) in old neurones. 6. Current-voltage relations and kinetics of high-threshold calcium currents showed no detectable age-dependent difference. 7. The run-down of high-threshold calcium currents in dorsal root ganglion neurones from old rats was practically insensitive to intracellular administration of cyclic AMP and ATP. The same intervention caused a significant deceleration of Ca2+ current run-down in the majority of neonatal and in some adult cells. 8. We suggest that the disappearance of the low-threshold calcium current and reduction of high-threshold calcium current with ageing is due to a depression of calcium channel expression during late ontogenesis. The decrease of sensitivity of high-threshold calcium channels to phosphorylation by cyclic AMP-dependent protein kinase in aged neurones could also be a reason for altered turnover between silent and functional pools of calcium channels...

The structural effect of systemic NGF treatment on permanently axotomised dorsal root ganglion cells in adult rats

TANDRUP, T. ; VESTERGAARD, S. ; TOMLINSON, D. R. ; DIEMEL, L. T. ; JAKOBSEN, J.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /04/1999 Português
Relevância na Pesquisa
66.49%
The effect of systemic NGF treatment on loss and shrinkage of dorsal root ganglion cells was studied in adult male rats after permanent axotomy. Nineteen 16 to 18-wk-old rats had their right 5th lumbar spinal nerve ligated and cut approximately 7 mm peripheral to the ganglion. Two days before the operation, treatment with subcutaneous injections of human recombinant NGF (1.0–0.5 mg/kg/day) was started in 9 test rats; 10 controls were given saline injections. After 1 mo the levels of substance P (SP) and calcitonin gene related peptide (CGRP) were significantly increased in intact sciatic nerve. The number and mean volume of perikarya were estimated using assumption-free stereological techniques including vertical sections, the Cavalieri principle, optical disectors, the planar rotator and systematic sampling techniques. Systemic NGF administration had no influence on survival of primary sensory neurons after axotomy. The number of perikarya was 14300 ( S.D.=1800) in axotomised ganglia in control rats versus 14700 ( S.D.=2100) in axotomised ganglia of NGF treated rats. The reduction of perikarya volume after axotomy was significantly less after NGF treatment (11600 μm3 in the control group versus 8000 μm3 in the NGF treated group). However...

Methyllycaconitine, α-bungarotoxin and (+)-tubocurarine block fast ATP-gated currents in rat dorsal root ganglion cells

Lalo, Ulyana; Pankratov, Yuri; Krishtal, Oleg; Alan North, R
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
66.54%
The effects of nicotinic acetylcholine receptor antagonists were studied on currents evoked by application of ATP to rat isolated dorsal root ganglion cells, and human embryonic kidney 293 cells expressing rat P2X3 and P2X2/3 receptors.The rapidly desensitising (within 100 ms) current in dorsal root ganglion cells was inhibited by methyllycaconitine, α-bungarotoxin and (+)-tubocurarine (concentrations giving half-maximal inhibition were approximately 40, 60 and 800 nM, respectively), but not by hexamethonium (100 μM) or mecamylamine (100 μM). The sustained (>250 ms) current in dorsal root ganglion cells was inhibited by (+)-tubocurarine (80% by 10 μM), but not by methyllycaconitine (200 nM), α-bungarotoxin (200 nM), mecamylamine (100 μM) or hexamethonium (100 μM).Rapidly desensitising currents evoked by α,βmethylene-ATP in human embryonic kidney cells expressing P2X3 receptors were inhibited by methyllycaconitine and α-bungarotoxin, at concentrations similar to those effective in dorsal root ganglion cells.The results indicate that some nicotinic acetylcholine receptor antagonists are potent blockers of P2X receptors on neurons, particularly the homo-oligomeric P2X3 receptor. This finding suggests that these drugs should be used with care to discriminate between P2X and neuronal acetylcholine receptor types.

Dorsal root ganglionectomy for pseudotumor of the L3 dorsal root ganglion: a rare case and a rare treatment

Tekkök, Ismail H.; Ruacan, Şevket
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
66.55%
Dorsal root ganglia are oval enlargements on the dorsal nerve roots and contain the cell bodies of sensory neurons. Asymmetry of dorsal root ganglia may occur naturally, yet natural occurrence of gigantic dorsal root ganglion (DRG) is rare. The patient was 61-year-old woman who presented with atypical symptoms like neuropathic pain and urinary distention. Neuroimaging has shown left L3-4 far-lateral disc herniation and a gigantic L3 DRG. At surgery, the dural sheath of the ganglion had to be opened and a firm, yellow-colored abnormal tissue was exposed. The abnormal tissue considered to be a tumor of neural origin was gross totally excised and the patient’s symptoms ceased immediately after surgery. Histopathological examination of the specimen revealed nothing more than normal DRG morphology. At 4 months postoperatively, the patient is well with mild L3 hyperesthesia and hyperalgesia. Dural sheath opening in neurosurgery is not a routine practice. The sheath may need to be opened when surgeon suspects of a tumor, a free disc fragment and any inflammation within the ganglion. Operative morphology of a severely edematous but non-tumoral (pseudotumor) ganglion has not previously been documented.

A neuronal cell surface heparan sulfate proteoglycan is required for dorsal root ganglion neuron stimulation of Schwann cell proliferation

Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 01/09/1985 Português
Relevância na Pesquisa
66.47%
Axons of dorsal root ganglion neurons express on their surfaces one or more proteins which are mitogenic for Schwann cells (Salzer, J., R. P. Bunge, and L. Glaser, 1980, J. Cell Biol., 84:767-778). Incubation of co-cultures of dorsal root ganglion neurons and Schwann cells with 4- methylumbelliferyl-beta-D-xyloside, an inhibitor of proteoglycan biosynthesis, decreases the mitogenic response of the Schwann cell by over 95%. The effect of the beta-D-xyloside has been localized to the neurons; pretreatment of neurons but not of Schwann cells with the inhibitor causes a marked reduction of the mitogenic response. In addition, Schwann cells treated with beta-D-xyloside are still mitogenically responsive to soluble Schwann cell mitogens (cholera toxin and glial growth factor). Neurons treated with heparitinase and membrane vesicles prepared from heparitinase-treated neurons show diminished mitogenicity for Schwann cells, while other proteoglycan lyases have no effect. We conclude that a cell surface heparan sulfate proteoglycan is a component of the Schwann cell mitogen present on the surface of dorsal root ganglion neurons.

Neuroprotective effect of herpes simplex virus-mediated gene transfer of erythropoietin in hyperglycemic dorsal root ganglion neurons

Chattopadhyay, Munmun; Walter, Claire; Mata, Marina; Fink, David J.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
66.53%
We examined the efficacy of herpes simplex virus vector-mediated gene transfer of erythropoietin in preventing neuropathy in mouse model of streptozotocin-diabetes. A replication-incompetent herpes simplex virus vector with erythropoietin under the control of the human cytomegalovirus promoter (vector DHEPO) was constructed. DHEPO expressed and released erythropoietin from primary dorsal root ganglion neurons in vitro, and following subcutaneous inoculation in the foot, expressed erythropoietin in dorsal root ganglion neurons in vivo. At 2 weeks after induction of diabetes, subcutaneous inoculation of erythropoietin prevented the reduction in sensory nerve amplitude characteristic of diabetic neuropathy measured 4 weeks later, preserved autonomic function measured by pilocarpine-induced sweating, and prevented the loss of nerve fibres in the skin and reduction of neuropeptide calcitonin gene-related peptide in the dorsal horn of spinal cord of the diabetic mice. We further investigated whether vector-mediated local expression of erythropoietin in dorsal root ganglion neurons can protect in vivo as well as in vitro hyperglycemia-induced axonal degeneration. Our findings show that the AKT/GSK-3β dependent pathway plays an important role in mediating the protection of erythropoietin against diabetic neuropathy. Herpes simplex virus-mediated transfer of erythropoietin to dorsal root ganglia may prove useful in treatment of diabetic neuropathy.

Proteinase-activated receptor-1 mediates dorsal root ganglion neuronal degeneration in HIV/AIDS

Acharjee, Shaona; Zhu, Yu; Maingat, Ferdinand; Pardo, Carlos; Ballanyi, Klaus; Hollenberg, Morley D.; Power, Christopher
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
66.6%
Distal sensory polyneuropathy is a frequent complication of lentivirus infections of the peripheral nervous system including both human immunodeficiency virus and feline immunodeficiency virus. Proteinase-activated receptors are G protein-coupled receptors implicated in the pathogenesis of neuroinflammation and neurodegeneration. Proteinase-activated receptor-1 is expressed on different cell types within the nervous system including neurons and glia, but little is known about its role in the pathogenesis of inflammatory peripheral nerve diseases, particularly lentivirus-related distal sensory polyneuropathy. Herein, the expression and functions of proteinase-activated receptor-1 in the peripheral nervous system during human immunodeficiency virus and feline immunodeficiency virus infections were investigated. Proteinase-activated receptor-1 expression was most evident in autopsied dorsal root ganglion neurons from subjects infected with human immunodeficiency virus, compared with the dorsal root ganglia of uninfected subjects. Human immunodeficiency virus or feline immunodeficiency virus infection of cultured human or feline dorsal root ganglia caused upregulation of interleukin-1β and proteinase-activated receptor-1 expression. In the human immunodeficiency virus- or feline immunodeficiency virus-infected dorsal root ganglia...

Effect of type-2 astrocytes on the viability of dorsal root ganglion neurons and length of neuronal processes

Fan, Chunling; Wang, Hui; Chen, Dan; Cheng, Xiaoxin; Xiong, Kun; Luo, Xuegang; Cao, Qilin
Fonte: Medknow Publications & Media Pvt Ltd Publicador: Medknow Publications & Media Pvt Ltd
Tipo: Artigo de Revista Científica
Publicado em 15/01/2014 Português
Relevância na Pesquisa
66.54%
The role of type-2 astrocytes in the repair of central nervous system injury remains poorly understood. In this study, using a relatively simple culture condition in vitro, type-2 astrocytes, differentiated from oligodendrocyte precursor cells by induction with bone morphogenetic protein-4, were co-cultured with dorsal root ganglion neurons. We examined the effects of type-2 astrocytes differentiated from oligodendrocyte precursor cells on the survival and growth of dorsal root ganglion neurons. Results demonstrated that the number of dorsal root ganglion neurons was higher following co-culture of oligodendrocyte precursor cells and type-2 astrocytes than when cultured alone, but lower than that of neurons co-cultured with type-1 astrocytes. The length of the longest process and the length of all processes of a single neuron were shortest in neurons cultured alone, followed by neurons co-cultured with type-2 astrocytes, then neurons co-cultured with oligodendrocyte precursor cells, and longest in neurons co-cultured with type-1 astrocytes. These results indicate that co-culture with type-2 astrocytes can increase neuronal survival rate and process length. However, compared with type-1 astrocytes and oligodendrocyte precursor cells...

Expression of gamma-aminobutyric acid type A receptor α2 subunit in the dorsal root ganglion of rats with sciatic nerve injury★

Lian, Yu; Wang, Yang; Ma, Ketao; Zhao, Lei; Zhang, Zhongshuang; Shang, Yuanyuan; Si, Junqiang; Li, Li
Fonte: Medknow Publications & Media Pvt Ltd Publicador: Medknow Publications & Media Pvt Ltd
Tipo: Artigo de Revista Científica
Publicado em 15/11/2012 Português
Relevância na Pesquisa
66.55%
The γ-aminobutyric acid neurotransmitter in the spinal cord dorsal horn plays an important role in pain modulation through primary afferent-mediated presynaptic inhibition. The weakening of γ-aminobutyric acid-mediated presynaptic inhibition may be an important cause of neuropathic pain. γ-aminobutyric acid-mediated presynaptic inhibition is related to the current strength of γ-aminobutyric acid A receptor activation. In view of this, the whole-cell patch-clamp technique was used here to record the change in muscimol activated current of dorsal root ganglion neurons in a chronic constriction injury model. Results found that damage in rat dorsal root ganglion neurons following application of muscimol caused concentration-dependent activation of current, and compared with the sham group, its current strength and γ-aminobutyric acid A receptor protein expression decreased. Immunofluorescence revealed that γ-aminobutyric acid type A receptor α2 subunit protein expression decreased and was most obvious at 12 and 15 days after modeling. Our experimental findings confirmed that the γ-aminobutyric acid type A receptor α2 subunit in the chronic constriction injury model rat dorsal root ganglion was downregulated, which may be one of the reasons for the reduction of injury in dorsal root ganglion neurons following muscimol-activated currents.

Effects of acupuncture on the expression of glial cell line-derived neurotrophic factor (GDNF) and basic fibroblast growth factor (FGF-2/bFGF) in the left sixth lumbar dorsal root ganglion following removal of adjacent dorsal root ganglia

Wang, T.; Yuan, Y.; Kang, Y.; Yuan, W.L.; Zhang, H.T.; Linyan Wu, L.; Feng, Z.T.
Fonte: Elsevier Sci Ireland Ltd Publicador: Elsevier Sci Ireland Ltd
Tipo: Artigo de Revista Científica
Publicado em //2005 Português
Relevância na Pesquisa
76.36%
This investigation studied the temporal changes in the expression of GDNF and FGF-2 in the left sixth lumbar (L6) dorsal root ganglion (DRG) after acupuncture in adult cats subjected to unilateral removal of adjacent DRG. The cats were divided into three groups. Group I were normal control animals. Group II cats were subjected to removal of DRG associated with the left L1-L5 and L7-S2 spinal nerves, sparing the L6 DRG. Group III cats received similar treatment as Group II ones, but in addition were subjected to acupuncture on the left side at acupuncture points (xuewei ) the day after the operation. Both Groups II and III animals were perfused under anesthesia at 7 and 14 days post-operation (dpo) and their left DRG were processed for the immunohistochemical demonstration of GDNF and FGF-2. Following removal of adjacent DRG, the average number of all GDNF stained neurons in L6 DRG was decreased at 7 dpo and more so at 14 dpo. Acupuncture reversed this trend, as demonstrated in the increased average number of immunopositive small-to-medium sized neurons. FGF-2 expression was also less marked at 7 dpo but returned to normal at 14 dpo. Acupuncture significantly increased the average number of FGF-2 positive neurons compared with that in operated animals. This increase was observed in both large and small-to-medium sized neurons. In conclusion...

Effects of electro-acupuncture on the expression of c-jun and c-fos in spared dorsal root ganglion and associated spinal laminae following removal of adjacent dorsal root ganglia in cats

Wang, T.; Yuan, W.L.; Ke, Q.; Song, X.B.; Zhou, X.; Kang, Y.; Zhang, H.T.; Lin, Y.; Hu, Y.L.; Feng, Z.T.; Linyan Wu, L.; Zhou, X.F.
Fonte: Pergamon-Elsevier Science Ltd Publicador: Pergamon-Elsevier Science Ltd
Tipo: Artigo de Revista Científica
Publicado em //2006 Português
Relevância na Pesquisa
96.51%
This study evaluated the plastic changes of c-jun and c-fos in the right sixth lumbar dorsal root ganglion (L₆ DRG), Rexed’s lamina II in representative spinal segments L₃, L₅, and L₆ and in the nucleus dorsalis (ND) at L₃segments after electro-acupuncture (EA) in cats subjected to removal of L₁–L₅ and L₇–S₂DRG. Following dorsal root ganglionectomy, there was a significant increase in the density of c-jun immunoreactivity in the neurons and glia in spinal lamina II and in the ND; there was also marked elevation in the expression of c-fos in ND. In both cases there was no change in the c-jun and c-fos immunoreactivity in the DRG. After EA in the operated animals, there was an up-regulation in the expression of c-jun in the L₆ DRG and the associated spinal lamina II; however, increased c-fos expression was detected only in the L₆ DRG. Western blot and RT-PCR were also performed to quantitatively explore the mRNA and protein expression changes in the spinal dorsal horn and associated DRG. Following partial deafferentation, there was a significant increase in the protein level of both c-jun and c-fos in the dorsal horn, while, in both cases there was no change in c-jun and c-fos protein and mRNA in the DRG. After EA in the operated animals...

Target-dependence of sensory neurons: An ultrastructural comparison of axotomised dorsal root ganglion neurons with allowed or denied reinnervation of peripheral targets

Johnson, I.; Sears, T.
Fonte: Pergamon-Elsevier Science Ltd Publicador: Pergamon-Elsevier Science Ltd
Tipo: Artigo de Revista Científica
Publicado em //2013 Português
Relevância na Pesquisa
96.36%
Evidence is emerging for a role of rough endoplasmic reticulum (RER) in the form of stress granules, the unfolded protein response and protein bodies in the response of neurons to injury and in neurodegenerative diseases. Here, we have studied the role of the peripheral target in regulating the RER and polyribosomes of Nissl bodies in axotomised adult cat dorsal root ganglion (DRG) neurons where axonal regeneration and peripheral target reinnervation was either allowed or denied. Retrograde labelling with horseradish peroxidise was used as an independent marker to enable selection of only those DRG neuronal cell bodies with axons in the injured intercostal nerves. Indications of polyribosomal dispersal were seen by 6 h following axotomy, and by 24 h the normal orderly arrangement of lamellae of RER in Nissl bodies had become disorganised. These ultrastructural changes preceded light microscopical chromatolysis by 1–3 d. The retrograde response was maximal 8–32 d after axotomy. Clusters of debris-laden satellite cells/macrophages were present at this time but no ultrastructural evidence of neuronal apoptosis or necrosis was seen and there were no differences in the initial retrograde response according to the type of injury. By 64 d following axotomy with reinnervation...

An ultrastructural study of neuronal changes in dorsal root ganglia (DRG) of rats after chronic cisplatin administrations

Cece, R.; Petruccioli, M.G.; Cavaletti, G.; Barajon, I.; Tredici, G.
Fonte: Murcia : F. Hernández Publicador: Murcia : F. Hernández
Tipo: Artigo de Revista Científica Formato: application/pdf
Português
Relevância na Pesquisa
76.17%
ln humans, the main dose-limiting side-effect of cisplatin (CDDP) treatment is a peripheral sensory neuropathy secondary to dorsal root ganglion (DRG) neuron involvement. To investigate further for neuronal alterations responsible for CDDP neurotoxicity we undertook the present experimental ultrastructural study, based on observations of 3 different groups of rats (6 animals in each group). Group A rats were treated with 1 mg/kg weekly for 9 weeks: Group B with 2 mglkg weekly for 9 weeks; and group C rats served as untreated controls. At the end of the experiment, rats were perfused with 3% glutaraldehyde and lumbar DRGs were prepared for electron microscopic observations. In CDDP-treated rats somatic, nuclear and. above all, nucleolar size was reduced. Ultrastructurally, the nucleolus was the most affected structure. Nucleolar alterations were quantified morphometrically. Less marked changes were seen in the nucleus and in the RER and Golgi apparatus of the cytoplasm. The number of lysosomes and lipofuscins was greatly increased in CDDP-treated rats. The ultrastructural alterations observed in CDDP rats suggest that CDDP may be neurotoxic due to a reduction in protein synthesis. This assumption would explain why cells such as neurons...

Anatomical study on the relationship between the dorsal root ganglion and the intervertebral disc in the lumbar spine

Vialle,Emiliano; Vialle,Luiz Roberto; Contreras,William; Jacob Junior,Chárbel
Fonte: Sociedade Brasileira de Ortopedia e Traumatologia Publicador: Sociedade Brasileira de Ortopedia e Traumatologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2015 Português
Relevância na Pesquisa
66.49%
ABSTRACTOBJECTIVE: To describe the location of the dorsal root ganglion in relation to the intervertebral disc, including the "triangular" safety zone for minimally invasive surgery in the lumbar spine. METHODS: Eight adult cadavers were dissected bilaterally in the lumbar region, using a posterolateral approach, so as to expose the L3L4 and L4L5 spaces, thereby obtaining measurements relating to the space between the intervertebral disc, pedicles cranial and caudal to the disc, path of the nerve root, dorsal ganglion and safety triangle. RESULTS: The measurements obtained were constant, without significant differences between levels or any laterality. The dorsal ganglion occupied the lateral border of the triangular safety zone in all the specimens analyzed. CONCLUSION: Precise localization of the ganglion shows that the safety margin for minimally invasive procedures is less than what is presented in studies that only involve measurements of the nerve root, thus perhaps explaining the presence of neuropathic pain after some of these procedures.

O papel da interleucina-1'beta' produzida no gânglio da raiz dorsal no desenvolvimento da hiperalgesia inflamatória; The role of dorsal root ganglion-produced interleukin-1'beta' in development of inflammatory hyperalgesia

Dionésia Araldi
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 14/05/2012 Português
Relevância na Pesquisa
96.42%
A liberação de Interleucina-1? (IL-1?) no tecido periférico estimula a síntese de Prostaglandinas (PGs), especialmente, da Prostaglandina-E2 (PGE2), que leva a sensibilização dos nociceptores aferentes primários induzindo a hiperalgesia inflamatória. Recentemente demonstramos que a IL-1? pode ativar diretamente o receptor de Interleucina-1 (IL-1R) do nociceptor aferente periférico e levar a liberação de PGE2 associada ao desenvolvimento da hiperalgesia. A IL-1? também é liberada no Gânglio da Raiz Dorsal (GRD), entretanto a função que a IL-1? desempenha no GRD para o desenvolvimento da hiperalgesia inflamatória ainda não está clara. Portanto, o objetivo deste estudo foi investigar se a liberação de IL-1? e a ativação do Receptor de Interleucina-1 Tipo I (IL-1RI) no GRD estão envolvidos no desenvolvimento da hiperalgesia inflamatória. A administração de IL-1Ra (antagonista natural de receptor IL- 1, 6 ?g) no GRD de ratos preveniu a hiperalgesia mecânica (avaliada por meio do von Frey Eletrônico) induzida pela administração intraplantar (i.pl) de Adjuvante Completo de Freund (CFA, 100 ?L), Carragenina (Cg, 100 ?g) ou IL-1? (0,5 pg), mas não pela administração i.pl de PGE2 (100 ng), avaliadas 3 horas após suas administrações. Além disso...