Renal cell carcinoma with an "uncoiling" tumor thrombus: intraoperative shift from level III to level IV.

BACKGROUND: The gold standard treatment for renal cell carcinoma (RCC) with tumor thrombus (TT) is complete surgical excision. The surgery is complex and challenging to the surgeon, especially with large tumor thrombus extending into the inferior vena cava (IVC) and right atrium. Traditionally, these difficult cases required the use of cardiopulmonary bypass (CPB) with or without deep hypothermic cardiac arrest, but in recent years, different surgical techniques derived from the field of liver transplantation have been used in efforts to avoid CPB. CASE PRESENTATION: We present a case of RCC with TT level IIIc (extending above major hepatic veins) that "uncoiled" intraoperatively into the right atrium after division of the IVC ligament, transforming into a level IV TT. Despite the new TT extension, the surgery was successfully completed exclusively through an abdominal approach without CPB and while using intraoperative transesophageal echocardiography (TEE) monitoring and a cardiothoracic team standby. CONCLUSIONS: This case highlights the need for a multidisciplinary approach and the utility of intraoperative continous TEE monitoring which helped to visualize the change of the TT venous extension, allowing the surgical teamto modify their surgical approach as needed avoiding a catastrophic event.

Impact of SAfinamide on Depressive Symptoms in Parkinson's Disease Patients (SADness-PD Study): A Multicenter Retrospective Study.

BACKGROUND: We aimed to assess the effects of safinamide on depression, motor symptoms, and the serotonin syndrome related to its co-administration with antidepressants in patients with Parkinson's disease (PD). METHODS: We retrospectively analyzed the data of patients at 1 and 3 months of follow-up compared to baseline. RESULTS: n = 82 (safinamide 50 mg = 22, 100 mg = 60, with antidepressants = 44). First, we found improvement in depression (Hamilton Depression Rating Scale: -6 ± 5.10 at 1 month and -7.27 ± 5.10 at 3 months, p < 0.0001; Patient Global Impression of Improvement Scale: 60.3% and 69.5% of patients at 1 and 3 months reported some improvement). Second, safinamide improved the daily life activities and motor symptoms/motor complications (Unified Parkinson's Disease Rating Scale (UPDRS-II): -2.51 ± 6.30 and -2.47 ± 6.11 at 1 and 3 months, p < 0.0001; III: -3.58 ± 8.68 and -4.03 ± 8.95 at 1 and 3 months, p < 0.0001; IV: -0.61 ± 2.61 and -0.8 ± 2.53 at 1 and 3 months, p < 0.0001). Third, 7.31% and 8.53% of patients developed non-severe adverse events related to safinamide at 1 and 3 months. Serotonin syndrome was not observed in the patients treated with antidepressants; some isolated serotonin syndrome symptoms were reported. CONCLUSIONS: Safinamide could be useful for treating depression in PD; it was effective for motor symptoms and motor complications and safe even when co-administered with antidepressants.

Experiencia clínica en el tratamiento de las fluctuaciones motoras en la enfermedad de Parkinson. Consenso Delphi de un grupo / Clinical experience in the treatment of motor fluctuations in Parkinsons disease. Delphi consensus of a group of experts in movement disorders

INTRODUCCIÓN: Las fluctuaciones motoras son una de las complicaciones más frecuentes en la enfermedad de Parkinson y su tratamiento sigue siendo complejo. Por ello, desde el Grupo de Trastornos del Movimiento de la Asociación Madrileña de Neurología presentamos nuestra experiencia clínica en el tratamiento de estas complicaciones, con la intención de que sea de utilidad en la toma de decisiones en la práctica clínica diaria. DESARROLLO: Se elaboraron 19 preguntas a partir de una revisión bibliográfica y una encuesta abierta respondida por los miembros de dicho grupo. Dichas cuestiones se debatieron en dos fases, utilizando la metodología Delphi. Considerando los resultados de la encuesta, el ajuste de la dosis de levodopa y los agonistas dopaminérgicos son la opción con mejor relación eficacia/tolerabilidad en el tratamiento de las fluctuaciones motoras. La rotigotina es útil en las fluctuaciones motoras asociadas a gastroparesia, y la apomorfina subcutánea intermitente, en pacientes con off impredecible. El efecto adverso más relevante asociado a los agonistas dopaminérgicos es el trastorno del control de impulsos. Los inhibidores de la catecol-O-metiltransferasa son útiles en las fluctuaciones motoras de inicio, especialmente en el wearing off. Los inhibidores de la monoaminooxidasa son fármacos, en general, bien tolerados y útiles en las fluctuaciones motoras. En caso de que estas medidas no resulten eficaces, se deben indicar terapias de segunda línea de manera individualizada. CONCLUSIÓN: El perfil clínico del paciente con enfermedad de Parkinson es primordial para decidir la terapia más adecuada en el tratamiento de las fluctuaciones motora

INTRODUCTION. Motor fluctuations are one of the most common complications of Parkinsons disease and their treatment is still a complex matter. Therefore, from the Neurology Movement Disorders Group we present our clinical experience in the treatment of these complications, with the intention of it being useful in decision-making in daily clinical practice. DEVELOPMENT. Nineteen questions were developed based on a literature review and an open survey answered by members of this group. These issues were discussed in two phases, using the Delphi methodology. Considering the results of the survey, levodopa dose adjustment and dopamine agonists are the option with the best efficacy/tolerability ratio in the treatment of motor fluctuations. Rotigotine is useful in the motor fluctuations associated with gastroparesis, and intermittent subcutaneous apomorphine has positive effects in patients with unpredictable off periods. The most relevant adverse effect associated with dopamine agonists is impulse control disorder. Catechol-O-methyltransferase inhibitors are useful in the initial stages of motor fluctuations, especially in wearing off. Monoamine oxidase inhibitors are generally drugs that are well-tolerated and useful in motor fluctuations. If these measures are not effective, second-line treatments should be indicated on a case-by-case basis. CONCLUSION. The clinical profile of patients with Parkinson's disease is paramount in deciding the most appropriate therapy for the treatment of motor fluctuations

Sexual Dysfunction in Early-Onset Parkinson's Disease: A Cross-Sectional, Multicenter Study.

BACKGROUND: Sexual dysfunction (SD) is one of the least studied non-motor symptoms in Parkinson's disease (PD). OBJECTIVES: To assess sexual function in a cohort of patients with early-onset PD (EOPD) and compare it to a group of healthy controls. METHODS: In this cross-sectional multicenter study, SD was assessed with gender-specific multi-dimensional self-reported questionnaires: The Brief Male Sexual Function Inventory (BSFI-M) and the Female Sexual Function Index (FSFI). Scores between patients and controls were compared and associations between SD and demographical and clinical variables were studied. RESULTS: One hundred and five patients (mean age 47.35±7.8, disease duration 6 (3-11) years, UPDRS part III 17 (10-23) and 90 controls were recruited. The BSFI-M total score was lower in EOPD men than in controls, and specific items were also significantly lower, such as drive, erections, ejaculation, and satisfaction. EOPD women had lower scores than controls in totalFSFI, and certain domains such as lubrication and pain. SD was present in 70.2% of patients and 52.5% of controls. Sexual satisfaction in 35.2% of patients and 81.2% of controls. By gender, male and female patients had more SD than controls but only male patients had more dissatisfaction than controls. Gender, higher depression scores and urinary dysfunction were associated with SD in multivariate analysis; and gender, UPDRS and urinary dysfunction with sexual satisfactionConclusion:In this Spanish cohort, SD and sexual dissatisfaction was more prevalent in EOPD patients than in the general population. Gender and urinary disfunction were associated with SD and sexual dissatisfaction.

Behavioral addictions in early-onset Parkinson disease are associated with DRD3 variants.

BACKGROUND: Impulse control disorders (ICDs) comprise abnormal behaviors frequently found in patients with Parkinson's disease (PD) receiving antiparkinsonian medication. ICDs in PD would develop when dopaminergic treatment overstimulates the dopamine receptor D3 (DR3). Here we studied whether DR3 gene (DRD3) is associated to ICD in PD patients with early-onset (EOPD). METHODS: We performed association analysis of the rs6280 DRD3 single nucleotide variation (SNV) (Ser9Gly) in a clinical sample of 126 non early-onset PD (NEOPD) and 73 EOPD (age at onset < 45). ICD was evaluated using the Questionnaire for Impulsive-Compulsive Disorders (QUIP) in PD. RESULTS: In the total sample, we found that a younger onset of PD is linked to ICD traits with a potentially addictive reinforcement (ICDARs, behavioral addictions) (p = .017) and a trend for total ICDs (p = .078) while punding was not associated (p = .75). EOPD sample showed an increase of DRD3 C+ genotype for ICD (p = .022) and ICDARs (p = .043) but not for punding (p = .170). The post-hoc analyses including the time of evolution and Pramipexol or Ropinirole treatments, confirmed the independent effect of the DRD3 upon ICDs (p = .028) and ICDARs (p = .041) as well as the interaction between DRD3 and Pramipexol treatment upon ICDARs (OR = 4.60, 95% CI 1.20-17.632, p = .026). The NEOPD group showed no association between DRD3 and ICDs. CONCLUSIONS: We found that behavioral addictions in PD are associated with an early onset of the disease, the rs6280 DRD3 SNV and the type of dopamine agonist. Further investigation in independent samples is warranted.

Effects of Stress, Reactive Oxygen Species, and the SOS Response on De Novo Acquisition of Antibiotic Resistance in Escherichia coli.

Strategies to prevent the development of antibiotic resistance in bacteria are needed to reduce the threat of infectious diseases to human health. The de novo acquisition of resistance due to mutations and/or phenotypic adaptation occurs rapidly as a result of interactions of gene expression and mutations (N. Handel, J. M. Schuurmans, Y. Feng, S. Brul, and B. H. Ter Kuile, Antimicrob Agents Chemother 58:4371-4379, 2014, http://dx.doi.org/10.1128/AAC.02892-14). In this study, the contribution of several individual genes to the de novo acquisition of antibiotic resistance in Escherichia coli was investigated using mutants with deletions of genes known to be involved in antibiotic resistance. The results indicate that recA, vital for the SOS response, plays a crucial role in the development of antibiotic resistance. Likewise, deletion of global transcriptional regulators, such as gadE or soxS, involved in pH homeostasis and superoxide removal, respectively, can slow the acquisition of resistance to a degree depending on the antibiotic. Deletion of the transcriptional regulator soxS, involved in superoxide removal, slowed the acquisition of resistance to enrofloxacin. Acquisition of resistance occurred at a lower rate in the presence of a second stress factor, such as a lowered pH or increased salt concentration, than in the presence of optimal growth conditions. The overall outcome suggests that a central cellular mechanism is crucial for the development of resistance and that genes involved in the regulation of transcription play an essential role. The actual cellular response, however, depends on the class of antibiotic in combination with environmental conditions.

Impulse control disorder in patients with Parkinson's disease under dopamine agonist therapy: a multicentre study.

BACKGROUND: Impulse control disorders (ICDs) encompass a wide spectrum of abnormal behaviour frequently found in cases of Parkinson's disease (PD) treated with dopamine agonists (DAs). The main aim of this study was to analyse ICD prevalence with different DAs. METHODS: We carried out a multicentre transversal study to evaluate the presence of ICDs in patients with PD chronically treated (>6 months) with a single non-ergolinic DA (pramipexole, ropinirole, or rotigotine). Clinical assessment of ICD was performed using the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's disease. RESULTS: Thirty-nine per cent of patients (91/233) fulfilled the clinical criteria for ICD. The group of patients with ICD symptoms (ICD+) differed from those without ICD symptoms (ICD-) in younger age and type of DA intake. Oral DA treatment (pramipexole and ropinirole) was associated with higher risk of ICDs compared with transdermal DA (rotigotine): 84/197 (42%) patients treated with oral DA developed ICD, versus 7/36 (19%) patients treated with transdermal DA (Fisher's exact text <0.01). In univariate analysis, a younger age (p<0.01), treatment with rasagiline (p<0.05), and especially treatment with an oral DA (pramipexole or ropinirole) (p<0.01) were significantly associated with ICD. Multivariate analysis confirmed that oral DA remained significantly associated with ICD (p: 0.014, OR: 3.14; 1.26-7.83). CONCLUSIONS: ICD was significantly associated with the use of the non-ergolinic oral DA (pramipexole and ropinirole) when compared with transdermal non-ergolinic DA (rotigotine). Since pramipexole, ropinirole and rotigotine are non-ergolinic DAs with very similar pharmacodynamic profiles, it is likely that other factors including route of administration (transdermal vs oral) explain the difference in risk of ICD development.

HspB1 silences translation of PDZ-RhoGEF by enhancing miR-20a and miR-128 expression to promote neurite extension.

HspB1 is a small heat shock protein implicated in neuronal survival and neurite growth; mutations in HspB1 have been identified in hereditary motor neuronopathies and Charcot Marie Tooth Type 2 neuropathies. In cortical neurons we found that expression of HspB1 decreased RhoA activity and RhoA-GTP protein, and reversed the inhibition of neurite extension induced by NogoA. HspB1 decreased PDZ-RhoGEF, a RhoA specific guanine nucleotide exchange factor, while other regulators of RhoA activity were unchanged. The decrease in PDZ-RhoGEF was independent of proteasomal or lysosomal degradation pathways and was not associated with changes in PDZ-RhoGEF mRNA. We sequenced the 3'UTR of rat PDZ-RhoGEF and found binding sites for miRNAs miR-20a, miR-128 and miR-132. Expression of these microRNAs was substantially increased in cortical neurons transfected with HspB1. Co-transfection of HspB1 with specific inhibitors of miR-20a or miR-128 prevented the decrease in PDZ-RhoGEF and blocked the neurite growth promoting effects of HspB1. Using the 3'UTR of PDZ-RhoGEF mRNA in a luciferase reporter construct we observed that HspB1, miR-20a and miR-128 each inhibited luciferase expression. We conclude that HspB1 regulates RhoA activity through modulation of PDZ-RhoGEF levels achieved by translational control through enhanced expression of specific miRNAs (miR-20a and miR-128). Regulation of RhoA activity by translational silencing of PDZ-RhoGEF may be the mechanism through which HspB1 is involved in regulation of neurite growth. As RhoA-GTPase plays a regulatory role in the organization and stability of cytoskeletal networks through its downstream effectors, the results suggest a possible mechanism linking HspB1 mutations and axonal cytoskeletal pathology.

Post-transcriptional regulation of GABAB receptor and GIRK1 channels by Nogo receptor 1.

BACKGROUND: Type B GABA receptors (GABA Rs) play a critical role in synaptic transmission. We carried out studies to determine whether neuronal cell surface expression of GABAB-Rs might be regulated by the Nogo receptor 1 (NgR1). RESULTS: siRNA knock-down of NgR1 resulted in a selective increase of GABAB R1 and GABAB R2 protein without altering the expression of GABAA receptor or GAD65. The increase in GABAB receptor subunits was unaccompanied by a change in mRNA, but inhibition of mTOR by rapamycin blocked the increase in GABAB protein. NgR1 siRNA also caused an increase in G protein coupled inwardly rectifying potassium channel (GIRK1). The increase in GABAB receptor and GIRK1 channel proteins was in the plasma membrane, determined by cell surface biotinylation. In NgR1 knockout mice, the amount of GABAB R2 and GIRK1 in hippocampus-derived synaptosomes was increased. CONCLUSIONS: Together these findings suggest that NgR1 mediated modulation of synaptic transmission may be accomplished, at least in part, through modulation of G protein coupled receptors and channels.

Full-length membrane-bound tumor necrosis factor-α acts through tumor necrosis factor receptor 2 to modify phenotype of sensory neurons.

Neuropathic pain resulting from spinal hemisection or selective spinal nerve ligation is characterized by an increase in membrane-bound tumor necrosis factor-alpha (mTNFα) in spinal microglia without detectable release of soluble TNFα (sTNFα). In tissue culture, we showed that a full-length transmembrane cleavage-resistant TNFα (CRTNFα) construct can act through cell-cell contact to activate neighboring microglia. We undertook the current study to test the hypothesis that mTNFα expressed in microglia might also affect the phenotype of primary sensory afferents, by determining the effect of CRTNFα expressed from COS-7 cells on gene expression in primary dorsal root ganglia (DRG) neurons. Co-culture of DRG neurons with CRTNFα-expressing COS-7 cells resulted in a significant increase in the expression of voltage-gated sodium channel isoforms NaV1.7 and NaV1.8, and voltage-gated calcium channel subunit CaV3.2 at both mRNA and protein levels, and enhanced CCL2 expression and release from the DRG neurons. Exposure to sTNFα produced an increase only in CCL2 expression and release. Treatment of the cells with an siRNA against tumor necrosis factor receptor 2 (TNFR2) significantly reduced CRTNFα-induced gene expression changes in DRG neurons, whereas administration of CCR2 inhibitor had no significant effect on CRTNFα-induced increase in gene expression and CCL2 release in DRG neurons. Taken together, the results of this study suggest that mTNFα expressed in spinal microglia can facilitate pain signaling by up-regulating the expression of cation channels and CCL2 in DRG neurons in a TNFR2-dependent manner.

Levodopa en el tratamiento de la enfermedad de Parkinson: mitos y realidades / Levodopa in the treatment of Parkinson’s disease: myths and realties

Durante los últimos años hemos sido testigos de una utilización preferente de agonistas dopaminérgicos (AD) como tratamiento de la enfermedad de Parkinson (EP), con la intención de retrasar en lo posible el desarrollo de fluctuaciones y discinesias. Sin embargo, la levodopa continúa siendo el fármaco antiparkinsoniano más eficaz y, probablemente, el que mejora un mayor número de síntomas de la enfermedad. En este artículo se ha realizado una revisión exhaustiva de la literatura por parte de un grupo de neurólogos expertos y miembros del Grupo de Trastornos del Movimiento de la Sociedad Española de Neurología sobre los beneficios y riesgos del tratamiento con levodopa en pacientes con EP. La principal conclusión de este artículo es que la levodopa continúa siendo el tratamiento más eficaz para la EP. Aunque el riesgo y la incidencia de desarrollar discinesias se mantiene en un nivel menor en el grupo tratado inicialmente con AD, el número de pacientes que desarrollan discinesias incapacitantes es muy bajo en todos los estudios y similar para los AD y la levodopa, y las escalas de calidad de vida son también similares en ambos grupos, lo que cuestiona el impacto que estas complicaciones motoras tienen sobre la calidad de vida de los pacientes con EP. A la vista de estos resultados, deberíamos plantearnos si está justificado privar a los pacientes del buen control de los síntomas que proporciona la levodopa por el temor a que desarrollen discinesias o fluctuaciones motoras leves que no van a mermar su calidad de vida. A ello hay que añadir la posibilidad de que desarrollen efectos secundarios graves, que son más frecuentes con el uso de AD (AU)

In recent years we have witnessed a growing tendency to opt for the use of dopamine agonists (DA) as treatment for Parkinson’s disease (PD), with the aim of delaying as far as possible the development of fluctuations and dyskinesias. Yet, levodopa continues to be the most effective antiparkinson drug and is probably the one that improves the greatest number of symptoms of the disease. This article reports on the results of a comprehensive review of the literature dealing with the benefits and risks of levodopa treatment in patients with PD which was conducted by a group of expert neurologists and members of the Spanish Neurology Society’s Movement Disorder Group. The main conclusion reached in this article is that levodopa continues to be the most effective treatment for PD. Although the risk and incidence of developing dyskinesias remains at a lower level in the group initially treated with DA, the number of patients who develop disabling dyskinesias is very low in all the studies and is similar for DA and for levodopa. Scores on the quality of life scales are also similar in the two groups, which casts some doubt on the impact that these motor complications have on the quality of life of patients with PD. In view of these findings, we should consider whether there is any real justification for depriving patients of the good control of their symptoms offered by levodopa owing to the fear of developing dyskinesias or mild motor fluctuations that are not really going to have any negative effect on their quality of life. There is also the possibility of their developing severe side effects, which are more frequent with the use of DA (AU)

[Candidate patient for subcutaneous apomorphine injection]. / Pacientes candidatos a apomorfina en inyección subcutánea intermitente.

Subcutaneous apomorphine injection is a fast-action, effective treatment option, that enables many patients to be rescued from predictable and non-predictable off episodes. It is an easy-to-use technique after minimum training. The neurologist can use it on patients with advanced Parkinson's disease only by following some basic procedures which are easily implemented in outpatient setting.

[Levodopa in the treatment of Parkinson's disease: myths and realties]. / Levodopa en el tratamiento de la enfermedad de Parkinson: mitos y realidades.

In recent years we have witnessed a growing tendency to opt for the use of dopamine agonists (DA) as treatment for Parkinson's disease (PD), with the aim of delaying as far as possible the development of fluctuations and dyskinesias. Yet, levodopa continues to be the most effective antiparkinson drug and is probably the one that improves the greatest number of symptoms of the disease. This article reports on the results of a comprehensive review of the literature dealing with the benefits and risks of levodopa treatment in patients with PD which was conducted by a group of expert neurologists and members of the Spanish Neurology Society's Movement Disorder Group. The main conclusion reached in this article is that levodopa continues to be the most effective treatment for PD. Although the risk and incidence of developing dyskinesias remains at a lower level in the group initially treated with DA, the number of patients who develop disabling dyskinesias is very low in all the studies and is similar for DA and for levodopa. Scores on the quality of life scales are also similar in the two groups, which casts some doubt on the impact that these motor complications have on the quality of life of patients with PD. In view of these findings, we should consider whether there is any real justification for depriving patients of the good control of their symptoms offered by levodopa owing to the fear of developing dyskinesias or mild motor fluctuations that are not really going to have any negative effect on their quality of life. There is also the possibility of their developing severe side effects, which are more frequent with the use of DA.

HSV-mediated gene transfer of C3 transferase inhibits Rho to promote axonal regeneration.

Although surgical re-implantation of spinal roots may improve recovery of proximal motor function after cervical root avulsion, recovery of sensory function necessary for fine motor coordination of the hand has been difficult to achieve, in large part because of failure of regeneration of axons into the spinal cord. In order to enhance regeneration, we constructed a non-replicating herpes simplex virus (HSV)-vector carrying the gene coding for bacterial C3 transferase (C3t). Subcutaneous inoculation of the vector into the skin of the forepaw 1 week after a dorsal C5-T1 rhizotomy resulted in expression of C3t in dorsal root ganglion (DRG) neurons and inhibition of Rho GTPase activity, resulting in extensive axonal regeneration into the spinal cord that correlated with improved sensory-motor coordination of the forepaw.

Herpes simplex virus vector-mediated expression of interleukin-10 reduces below-level central neuropathic pain after spinal cord injury.

BACKGROUND: Neuroimmune activation in the spinal dorsal horn plays an important role in the pathogenesis of chronic pain after peripheral nerve injury. OBJECTIVE: The aim of this study was to examine the role of neuroimmune activation in below-level neuropathic pain after traumatic spinal cord injury (SCI). METHODS: Right hemilateral SCI was created in male Sprague-Dawley rats by controlled blunt impact through a T12 laminectomy. Pain-related behaviors were assessed using both evoked reflex responses and an operant conflict-avoidance test. Neuroimmune activation was blocked by the anti-inflammatory cytokine interleukin-10 (IL-10) delivered by a nonreplicating herpes simplex virus (HSV)-based gene transfer vector (vIL10). Markers of neuroimmune activation were assessed using immunohistochemistry and Western blot. RESULTS: One week after SCI, injured animals demonstrated mechanical allodynia, thermal hyperalgesia, and mechanical hyperalgesia in the hind limbs below the level of injury. Animals inoculated with vIL10 had a statistically significant reduction in all of these measures compared to injured rats or injured rats inoculated with control vector. Conflict-avoidance behavior of injured rats inoculated with vIL10 was consistent with significantly reduced pain compared with injured rats injected with control vector. These behavioral results correlated with a significant decrease in spinal tumor necrosis factor α (mTNFα) expression assessed by Western blot and astrocyte activation assessed by glial fibrillary acidic protein immunohistochemistry. CONCLUSION: Below-level pain after SCI is characterized by neuroimmune activation (increase mTNFα and astrocyte activation). Blunting of the neuroimmune response by HSV-mediated delivery of IL-10 reduced pain-related behaviors, and may represent a potential novel therapeutic agent.

Targeted drug delivery to the peripheral nervous system using gene therapy.

Gene transfer to target delivery of neurotrophic factors to the primary sensory afferent for treatment of polyneuropathy, or of inhibitory neurotransmitters for relief of chronic pain, offers the possibility of a highly selective targeted release of bioactive molecules within the nervous system. Preclinical studies with non-replicating herpes simplex virus (HSV)-based vectors injected into the skin to transduce neurons in the dorsal root ganglion have demonstrated efficacy in reducing-pain related behaviors in animal models of inflammatory pain, neuropathic pain, and pain caused by cancer, and in preventing progression of sensory neuropathy caused by toxins, chemotherapeutic drugs or resulting from diabetes. Successful completion of the first phase 1 clinical trial of HSV-mediated gene transfer in patients with intractable pain from cancer has set the stage for further clinical trials of this approach.

Reduction of voltage gated sodium channel protein in DRG by vector mediated miRNA reduces pain in rats with painful diabetic neuropathy.

BACKGROUND: Painful neuropathy is a common complication of diabetes. Previous studies have identified significant increases in the amount of voltage gated sodium channel isoforms Na(V)1.7 and Na(V)1.3 protein in the dorsal root ganglia (DRG) of rats with streptozotocin (STZ)-induced diabetes. We found that gene transfer-mediated release of the inhibitory neurotransmitters enkephalin or gamma amino butyric acid (GABA) from DRG neurons in diabetic animals reduced pain-related behaviors coincident with a reduction in Na(V)1.7 protein levels in DRG in vivo. To further evaluate the role of Na(V)α subunit levels in DRG in the pathogenesis of pain in diabetic neuropathy, we constructed a non-replicating herpes simplex virus (HSV)-based vector expressing a microRNA (miRNA) against Na(V)α subunits. RESULTS: Subcutaneous inoculation of the miRNA-expressing HSV vector into the feet of diabetic rats to transduce DRG resulted in a reduction in Na(V)α subunit levels in DRG neurons, coincident with a reduction in cold allodynia, thermal hyperalgesia and mechanical hyperalgesia. CONCLUSIONS: These data support the role of increased Na(V)α protein in DRG in the pathogenesis of pain in diabetic neuropathy, and provide a proof-of-principle demonstration for the development of a novel therapy that could be used to treat intractable pain in patients with diabetic neuropathy.

Neuronal Nogo-A regulates glutamate receptor subunit expression in hippocampal neurons.

Nogo-A and its cognate receptor NogoR1 (NgR1) are both expressed in neurons. To explore the function of these proteins in neurons of the CNS, we carried out a series of studies using postnatal hippocampal neurons in culture. Interfering with the binding of Nogo-A to NgR1 either by adding truncated soluble fragment of NgR1 (NgSR) or by reducing NgR1 protein with a specific siRNA, resulted in a marked reduction in Nogo-A expression. Inhibition of Rho-ROCK or MEK-MAPK signaling resulted in a similar reduction in neuronal Nogo-A mRNA and protein. Reducing Nogo-A protein levels by siRNA resulted in an increase in the post-synaptic scaffolding protein PSD95, as well as increases in GluA1/GluA2 AMPA receptor and GluN1/GluN2A/GluN2B NMDA glutamate receptor subunits. siRNA treatment to reduce Nogo-A resulted in phosphorylation of mTOR; addition of rapamycin to block mTOR signaling prevented the up-regulation in glutamate receptor subunits. siRNA reduction of NgR1 resulted in increased expression of the same glutamate receptor subunits. Taken together the results suggest that transcription and translation of Nogo-A in hippocampal neurons is regulated by a signaling through NgR1, and that interactions between neuronal Nogo-A and NgR1 regulate glutamatergic transmission by altering NMDA and AMPA receptor levels through an rapamycin-sensitive mTOR-dependent translation mechanism.

TNFα is involved in neuropathic pain induced by nucleoside reverse transcriptase inhibitor in rats.

In patients with HIV/AIDS, neuropathic pain is a common neurological complication. Infection with the HIV itself may lead to neuropathic pain, and painful symptoms are enhanced when patients are treated with nucleoside reverse transcriptase inhibitors (NRTIs). The mechanisms by which NRTIs contribute to the development of neuropathic pain are not known. In the current studies, we tested the role of TNFα in antiretroviral drug-induced neuropathic pain. We administered 2',3'-dideoxycytidine (ddC, one of the NRTIs) systemically to induce mechanical allodynia. We found that ddC induced overexpression of both mRNA and proteins of GFAP and TNFα in the spinal dorsal horn. TNFα was colocalized with GFAP in the spinal dorsal horn and with NeuN in the DRG. Knockdown of TNFα with siRNA blocked the mechanical allodynia induced by ddC. Intrathecal administration of glial inhibitor or recombinant TNF soluble receptor, reversed mechanical allodynia induced by ddC. These results suggest that TNFα is involved in NRTI-induced neuropathic pain.

Gene therapy for pain: results of a phase I clinical trial.

OBJECTIVE: Preclinical evidence indicates that gene transfer to the dorsal root ganglion using replication-defective herpes simplex virus (HSV)-based vectors can reduce pain-related behavior in animal models of pain. This clinical trial was carried out to assess the safety and explore the potential efficacy of this approach in humans. METHODS: We conducted a multicenter, dose-escalation, phase I clinical trial of NP2, a replication-defective HSV-based vector expressing human preproenkephalin (PENK) in subjects with intractable focal pain caused by cancer. NP2 was injected intradermally into the dermatome(s) corresponding to the radicular distribution of pain. The primary outcome was safety. As secondary measures, efficacy of pain relief was assessed using a numeric rating scale (NRS), the Short Form McGill Pain Questionnaire (SF-MPQ), and concurrent opiate usage. RESULTS: Ten subjects with moderate to severe intractable pain despite treatment with >200mg/day of morphine (or equivalent) were enrolled into the study. Treatment was well tolerated with no study agent-related serious adverse events observed at any point in the study. Subjects receiving the low dose of NP2 reported no substantive change in pain. Subjects in the middle- and high-dose cohorts reported pain relief as assessed by NRS and SF-MPQ. INTERPRETATION: Treatment of intractable pain with NP2 was well tolerated. There were no placebo controls in this relatively small study, but the dose-responsive analgesic effects suggest that NP2 may be effective in reducing pain and warrants further clinical investigation.