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1.
Soc Psychiatry Psychiatr Epidemiol ; 53(6): 555-566, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29696304

RESUMEN

PURPOSE: This work complements a quantitative review by Nortje et al. (Lancet Psychiatry 3(2):154-170, 2016) by exploring the qualitative literature in regard to the perceived effectiveness of traditional and faith healing of mental disorders. METHOD: Qualitative studies focusing specifically on traditional and/or faith healing practices for mental illness were retrieved from eight databases. Data were extracted  into basic coding sheets to facilitate the assessment of the quality of eligible papers using the COREQ. RESULTS: Sixteen articles met the inclusion criteria. Despite methodological limitations, there was evidence from the papers that stakeholders perceived traditional and/or faith healing to be effective in treating mental illness, especially when used in combination with biomedical treatment. CONCLUSION: Patients will continue to seek treatment from traditional and/or faith healers for mental illness if they perceive it to be effective regardless of alternative biomedical evidence. This provides opportunities for collaboration to address resource scarcity in low to middle income countries.


Asunto(s)
Curación por la Fe , Medicina Tradicional , Trastornos Mentales/terapia , Evaluación del Resultado de la Atención al Paciente , Humanos , Investigación Cualitativa
2.
Phys Med Biol ; 68(20)2023 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-37748504

RESUMEN

A subcommittee of the Netherlands Commission on Radiation Dosimetry (NCS) was initiated in 2018 with the task to update and extend a previous publication (NCS-15) on the quality assurance of treatment planning systems (TPS) (Bruinviset al2005). The field of treatment planning has changed considerably since 2005. Whereas the focus of the previous report was more on the technical aspects of the TPS, the scope of this report is broader with a focus on a department wide implementation of the TPS. New sections about education, automated planning, information technology (IT) and updates are therefore added. Although the scope is photon therapy, large parts of this report will also apply to all other treatment modalities. This paper is a condensed version of these guidelines; the full version of the report in English is freely available from the NCS website (http://radiationdosimetry.org/ncs/publications). The paper starts with the scope of this report in relation to earlier reports on this subject. Next, general aspects of the commissioning process are addressed, like e.g. project management, education, and safety. It then focusses more on technical aspects such as beam commissioning and patient modeling, dose representation, dose calculation and (automated) plan optimisation. The final chapters deal with IT-related subjects and scripting, and the process of updating or upgrading the TPS.

3.
Science ; 260(5108): 692-5, 1993 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-8480180

RESUMEN

Sensorineural hearing loss resulting from the loss of auditory hair cells is thought to be irreversible in mammals. This study provides evidence that retinoic acid can stimulate the regeneration in vitro of mammalian auditory hair cells in ototoxic-poisoned organ of Corti explants in the rat. In contrast, treatment with retinoic acid does not stimulate the formation of extra hair cells in control cultures of Corti's organ. Retinoic acid-stimulated hair cell regeneration can be blocked by cytosine arabinoside, which suggests that a period of mitosis is required for the regeneration of auditory hair cells in this system. These results provide hope for a recovery of hearing function in mammals after auditory hair cell damage.


Asunto(s)
Células Ciliadas Auditivas/efectos de los fármacos , Órgano Espiral/efectos de los fármacos , Regeneración/efectos de los fármacos , Tretinoina/farmacología , Animales , Citarabina/farmacología , Células Ciliadas Auditivas/fisiología , Células Ciliadas Auditivas/ultraestructura , Microscopía Electrónica , Neomicina/toxicidad , Técnicas de Cultivo de Órganos , Órgano Espiral/fisiología , Órgano Espiral/ultraestructura , Ratas
4.
Neuron ; 14(6): 1153-64, 1995 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-7605630

RESUMEN

The physiological role of BDNF and NT-3 in the development of the vestibular and auditory systems was investigated in mice that carry a deleted BDNF and/or NT-3 gene. BDNF was the major survival factor for vestibular ganglion neurons, and NT-3, for spiral ganglion neurons. Lack of BDNF and NT-3 did not affect ingrowth of nerve fibers into the vestibular epithelium, but BDNF mutants failed to maintain afferent and efferent innervation. In the cochlea, BDNF mutants lost type 2 spiral neurons, causing an absence of outer hair cell innervation. NT-3 mutants showed a paucity of afferents and lost 87% of spiral neurons, presumably corresponding to type 1 neurons, which innervate inner hair cells. Double mutants had an additive loss, lacking all vestibular and spiral neurons. These results show that BDNF and NT-3 are crucial for inner ear development and, although largely coexpressed, have distinct and nonoverlapping roles in the vestibular and auditory systems.


Asunto(s)
Factores de Crecimiento Nervioso/fisiología , Proteínas del Tejido Nervioso/fisiología , Vestíbulo del Laberinto/inervación , Vías Aferentes/citología , Animales , Factor Neurotrófico Derivado del Encéfalo , Cóclea/inervación , Vías Eferentes/citología , Células Ciliadas Auditivas/fisiología , Inmunohistoquímica , Ratones , Mutación , Factores de Crecimiento Nervioso/genética , Proteínas del Tejido Nervioso/genética , Neuronas/citología , Neuronas/fisiología , Neurotrofina 3 , Vestíbulo del Laberinto/fisiología
5.
Neuroscience ; 157(2): 405-13, 2008 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-18838114

RESUMEN

OBJECTIVE: Determine the molecular mechanism(s) behind tumor necrosis factor-alpha (TNFalpha)-induced loss of auditory hair cells and the ability of dexamethasone base (DXMb) to protect against TNFalpha ototoxicity. METHODS: Hair cell counts: Three-day-old rat organ of Corti explants were cultured under three different conditions: 1) untreated-control; 2) TNFalpha (2 mug/ml); and 3) TNFalpha (2 mug/ml)+DXMb (70 mug/ml) for 4 days, fixed, and stained with FITC-phalloidin. Hair cells were counted in the basal and middle turns. Gene expression: total RNA was extracted from the three different groups of explants at 0, 12, 24 and 48 h. Using quantitative real-time RT-PCR, mRNAs were transcribed into cDNAs and amplification was performed using primers for rat ss-actin (housekeeping gene), TNFR1, Bcl-2, Bax, and Bcl-xl. RESULTS: DXMb protected explant hair cells from TNFalpha-induced loss. Bax gene expression was greater in TNFalpha-exposed explants compared with TNFalpha+DXMb-treated explants at 48 h (P=0.023), confirmed by the increase in the Bax/Bcl-2 ratio at 48 h (P<0.001). These results correlated with increased TNFR1 expression at 24 h (P=0.038). DXMb otoprotection in TNFalpha-exposed cultures was accompanied by an up-regulation of Bcl-xl at both the 24 (P<0.001) and 48 h time points (P=0.030) and up-regulation of Bcl-2 expression at 24 h (P=0.018). DXMb treatment also prevented increases in the expression levels of Bax, TNFR1, and the Bax/Bcl-2 ratio that occurred in untreated TNFalpha-exposed explants. CONCLUSIONS: TNFalpha's ototoxicity may be mediated through an up-regulation of Bax and TNFR1 expression as well as an increase in the Bax/Bcl-2 ratio. DXMb protects the organ of Corti against TNFalpha ototoxicity by up-regulating Bcl-2 and Bcl-xl expression and by inhibiting TNFalpha-induced increases in Bax, TNFR1, and the Bax/Bcl-2 ratio. These results support the use of local dexamethasone treatment to conserve hearing following a trauma.


Asunto(s)
Apoptosis/efectos de los fármacos , Dexametasona/farmacología , Expresión Génica/efectos de los fármacos , Glucocorticoides/farmacología , Células Ciliadas Auditivas/efectos de los fármacos , Órgano Espiral/citología , Análisis de Varianza , Animales , Animales Recién Nacidos , Apoptosis/genética , Técnicas de Cultivo de Órganos , Órgano Espiral/efectos de los fármacos , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Ratas , Ratas Sprague-Dawley , Receptores Tipo I de Factores de Necrosis Tumoral/genética , Receptores Tipo I de Factores de Necrosis Tumoral/metabolismo , Factores de Tiempo , Factor de Necrosis Tumoral alfa/toxicidad , Proteína X Asociada a bcl-2/genética , Proteína X Asociada a bcl-2/metabolismo , Proteína bcl-X/genética , Proteína bcl-X/metabolismo
6.
Curr Opin Neurobiol ; 8(4): 480-7, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9751665

RESUMEN

Damaged hair cells in the avian basilar papilla are replaced by regenerative proliferation of supporting cells and transdifferentiation of supporting cells into hair cells. In the mammalian vestibular system, transdifferentiation and, possibly, the repair of damaged hair cells appear to play significant roles. Several growth factors have been found to be associated with the regeneration/repair process: insulin, insulin-like growth factor 1 (IGF-1), and fibroblast growth factors are important for avian inner ear regeneration/repair, whereas epidermal growth factor, transforming growth factor alpha, insulin, IGF-1, and IGF-2 are important for regeneration/repair in the mammalian labyrinth. Increasing evidence suggests that regeneration/repair of mammalian auditory hair cells is possible during the early neonatal period and may exist to a very limited degree at later times.


Asunto(s)
Aves/fisiología , Sustancias de Crecimiento/fisiología , Células Ciliadas Auditivas Internas/fisiología , Mamíferos/fisiología , Regeneración/fisiología , Células Receptoras Sensoriales/fisiología , Animales , Vías Auditivas/fisiología , Vestíbulo del Laberinto/fisiología
7.
Artículo en Inglés | MEDLINE | ID: mdl-28596897

RESUMEN

BACKGROUND: Lower and middle income countries (LMICs) are home to >80% of the global population, but mental health researchers and LMIC investigator led publications are concentrated in 10% of LMICs. Increasing research and research outputs, such as in the form of peer reviewed publications, require increased capacity building (CB) opportunities in LMICs. The National Institute of Mental Health (NIMH) initiative, Collaborative Hubs for International Research on Mental Health reaches across five regional 'hubs' established in LMICs, to provide training and support for emerging researchers through hub-specific CB activities. This paper describes the range of CB activities, the process of monitoring, and the early outcomes of CB activities conducted by the five research hubs. METHODS: The indicators used to describe the nature, the monitoring, and the early outcomes of CB activities were developed collectively by the members of an inter-hub CB workgroup representing all five hubs. These indicators included but were not limited to courses, publications, and grants. RESULTS: Results for all indicators demonstrate a wide range of feasible CB activities. The five hubs were successful in providing at least one and the majority several courses; 13 CB recipient-led articles were accepted for publication; and nine grant applications were successful. CONCLUSIONS: The hubs were successful in providing CB recipients with a wide range of CB activities. The challenge remains to ensure ongoing CB of mental health researchers in LMICs, and in particular, to sustain the CB efforts of the five hubs after the termination of NIMH funding.

8.
Neuroscience ; 316: 261-78, 2016 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-26718602

RESUMEN

Cochlear fibrosis is a common finding following cochlear implantation. Evidence suggests that cochlear fibrosis could be triggered by inflammation and epithelial-to-mesenchymal cell transition (EMT). In this study, we investigate the mechanisms of cochlear fibrosis and the risk/benefit ratio of local administration of the anti-inflammatory drug dexamethasone (DEX) and antimitotic drug aracytine (Ara-C). Cochlear fibrosis was evaluated in cochlear fibrosis models of rat cochlear slices in vitro and in KLH-induced immune labyrinthitis and platinum wire cochlear implantation-induced fibrosis in vivo. Cochleae were invaded with tissue containing fibroblastic cells expressing α-SMA (alpha smooth muscle actin), which along with collagen I, fibronectin, and laminin in the extracellular matrix, suggests the involvement of a fibrotic process triggered by EMT in vitro and in vivo. After perilymphatic injection of an adenoviral vector expressing GFP in vivo, we demonstrated that the fibroblastic cells derived from the mesothelial cells of the scalae tympani and vestibuli. Activation of inflammatory and EMT pathways was further assessed by ELISA analysis of the expression of IL-1ß and TGF-ß1. Both markers were elevated in vitro and in vivo, and DEX and Ara-C were able to reduce IL-1ß and TGF-ß1 production. After 5days of culture in vitro, quantification of calcein-positive cells revealed that Ara-C was 30-fold more efficient in preventing fibrosis, and provoked less sensory hair cell loss, than DEX. In KLH-induced immune labyrinthitis and platinum wire-implanted models, Ara-C was more efficient in preventing proliferation of fibrosis with less side effects on hair cells and neurons than DEX. In conclusion, DEX and Ara-C both prevent fibrosis in the cochlea. Analysis of the risk/benefit ratio favors the use of Ara-C for preventing cochlear fibrosis.


Asunto(s)
Antiinflamatorios/farmacología , Cóclea , Citocinas/metabolismo , Heridas y Lesiones/complicaciones , Adyuvantes Inmunológicos/toxicidad , Animales , Cóclea/efectos de los fármacos , Cóclea/lesiones , Cóclea/patología , Cóclea/ultraestructura , Colágeno/metabolismo , Dexametasona/farmacología , Modelos Animales de Enfermedad , Electrodos Implantados/efectos adversos , Potenciales Evocados Auditivos del Tronco Encefálico/efectos de los fármacos , Fibronectinas/metabolismo , Fibrosis/tratamiento farmacológico , Fibrosis/etiología , Células Ciliadas Auditivas/efectos de los fármacos , Células Ciliadas Auditivas/patología , Hemocianinas/toxicidad , Técnicas In Vitro , Laminina/metabolismo , Técnicas de Cultivo de Órganos , Ratas , Ratas Wistar , Células Receptoras Sensoriales/efectos de los fármacos , Factores de Tiempo
9.
J Neurosci ; 23(24): 8596-607, 2003 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-13679429

RESUMEN

Hearing loss can be caused by a variety of insults, including acoustic trauma and exposure to ototoxins, that principally effect the viability of sensory hair cells via the MAP kinase (MAPK) cell death signaling pathway that incorporates c-Jun N-terminal kinase (JNK). We evaluated the otoprotective efficacy of D-JNKI-1, a cell permeable peptide that blocks the MAPK-JNK signal pathway. The experimental studies included organ cultures of neonatal mouse cochlea exposed to an ototoxic drug and cochleae of adult guinea pigs that were exposed to either an ototoxic drug or acoustic trauma. Results obtained from the organ of Corti explants demonstrated that the MAPK-JNK signal pathway is associated with injury and that blocking of this signal pathway prevented apoptosis in areas of aminoglycoside damage. Treatment of the neomycin-exposed organ of Corti explants with D-JNKI-1 completely prevented hair cell death initiated by this ototoxin. Results from in vivo studies showed that direct application of D-JNKI-1 into the scala tympani of the guinea pig cochlea prevented nearly all hair cell death and permanent hearing loss induced by neomycin ototoxicity. Local delivery of D-JNKI-1 also prevented acoustic trauma-induced permanent hearing loss in a dose-dependent manner. These results indicate that the MAPK-JNK signal pathway is involved in both ototoxicity and acoustic trauma-induced hair cell loss and permanent hearing loss. Blocking this signal pathway with D-JNKI-1 is of potential therapeutic value for long-term protection of both the morphological integrity and physiological function of the organ of Corti during times of oxidative stress.


Asunto(s)
Inhibidores Enzimáticos/farmacología , Células Ciliadas Auditivas/efectos de los fármacos , Pérdida Auditiva Provocada por Ruido/prevención & control , Pérdida Auditiva/prevención & control , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Órgano Espiral/efectos de los fármacos , Péptidos/farmacología , Estimulación Acústica , Aminoglicósidos/antagonistas & inhibidores , Aminoglicósidos/toxicidad , Animales , Muerte Celular/efectos de los fármacos , Células Cultivadas , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Vías de Administración de Medicamentos , Evaluación Preclínica de Medicamentos , Cobayas , Células Ciliadas Auditivas/citología , Pérdida Auditiva/inducido químicamente , Pruebas Auditivas , Técnicas In Vitro , Proteínas Quinasas JNK Activadas por Mitógenos , Ligandos , Ratones , Fármacos Neuroprotectores/farmacología , Órgano Espiral/citología , Proteínas Proto-Oncogénicas c-fos/metabolismo , Transducción de Señal/efectos de los fármacos
10.
Hum Gene Ther ; 7(2): 173-82, 1996 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-8788168

RESUMEN

The neurotrophins are a family of growth factors that play an important role in the development and maintenance of the nervous system. Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family that appears to participate in the maturation and function of mammalian auditory neurons. Forms of deafness due to varied injurious stimuli that are amenable to treatment with implantable prosthetic devices require the survival of these BDNF-responsive auditory neurons for effective outcome. To evaluate the feasibility of developing a gene therapy for deafness that may be used in conjunction with a prosthetic device, we constructed replication-defective herpes simplex virus (HSV) amplicon vectors that carry the human BDNF cDNA. Using these vectors, HSVbdnf and HSVbdnflac (expresses BDNF and Escherichia coli beta-galactosidase), we evaluated the expression and biological activity in established cell lines and explant cultures prepared from spiral ganglia of the murine ear. Gene transfer with HSVbdnf resulted in the efficient expression of human BDNF mRNA in murine fibroblasts. Using two BDNF-responsive cell lines, PC12trkB and MG87trkB, we demonstrate efficient secretion of biologically active BDNF. Finally, transduction of explanted spiral ganglia with HSVbdnflac elicited robust neuritic process outgrowth comparable to exogenously added BDNF. Overall, these data demonstrate that HSV vectors can efficiently transfer and express the BDNF gene in many cell types, including auditory neurons. Moreover, they suggest that similar vectors may be used to express the neurotrophin in auditory neurons in vivo and perhaps as adjunctive gene therapy for deafness.


Asunto(s)
Nervio Coclear/fisiología , Vectores Genéticos/genética , Factores de Crecimiento Nervioso/genética , Regeneración Nerviosa , Proteínas del Tejido Nervioso/genética , Simplexvirus/genética , Animales , Secuencia de Bases , Factor Neurotrófico Derivado del Encéfalo , Línea Celular , Técnicas de Cultivo , Expresión Génica , Técnicas de Transferencia de Gen , Humanos , Ratones , Datos de Secuencia Molecular , Degeneración Nerviosa , Factores de Crecimiento Nervioso/biosíntesis , Proteínas del Tejido Nervioso/biosíntesis , Neuritas/fisiología , ARN Mensajero/biosíntesis , Ratas , Ratas Wistar , Ganglio Espiral de la Cóclea/fisiología
11.
Curr Drug Targets CNS Neurol Disord ; 3(4): 325-32, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15379608

RESUMEN

The c-Jun N-terminal kinases (JNKs) are also called stress activated protein kinases (SAPKs) and are members of the family of mitogen activated protein kinases (MAPKs). While the functions of the JNKs under physiological conditions are diverse and not completely understood, there is increasing evidence that JNKs are potent effectors of apoptosis of oxidative stress-damaged cells in both the brain and the mammalian inner ear following a trauma. The activation of the inducible transcription factor c-Jun by N-terminal phosphorylation is a central event in JNK-mediated apoptosis of oxidative stress-damaged auditory hair cells following exposure to either acoustic trauma or a toxic level of an aminoglycoside antibiotic and also the apoptosis of auditory neurons as a consequence of a loss of the trophic support provided by the auditory hair cells. In this review, we summarise what is known about the expression and activation of G-proteins, JNKs, c-Jun and c-Fos under oxidative stress conditions within the mammalian cochlea. A particular focus is put on a new peptide conjugate that is a promising protective agent(s) and pharmacological strategies for preventing cochlear damage induced by both acoustic trauma and aminoglycoside ototoxic damage.


Asunto(s)
Apoptosis/fisiología , Sordera/enzimología , Sistema de Señalización de MAP Quinasas/fisiología , Degeneración Nerviosa/enzimología , Estrés Oxidativo/fisiología , Péptidos/farmacología , Aminoglicósidos/antagonistas & inhibidores , Aminoglicósidos/toxicidad , Animales , Apoptosis/efectos de los fármacos , Sordera/tratamiento farmacológico , Sordera/fisiopatología , Células Ciliadas Auditivas/efectos de los fármacos , Células Ciliadas Auditivas/enzimología , Células Ciliadas Auditivas/patología , Humanos , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Degeneración Nerviosa/tratamiento farmacológico , Degeneración Nerviosa/fisiopatología , Ruido/efectos adversos , Estrés Oxidativo/efectos de los fármacos , Péptidos/uso terapéutico
12.
Biotechniques ; 16(1): 76-80, 1994 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8136146

RESUMEN

Detection in combination with localization of low copy gene expression can be difficult to achieve. The use of reverse transcription PCR on tissue sections with a fluorescent marker provides localization of mRNA expression on a cellular level, and when combined with confocal microscopy and image analysis it also allows for an estimate of the relative intensity of fluorescence. A good example of the application of this method is the localization of nerve growth factor (NGF) mRNA expression in the inner ear. NGF through indirect tests appears to be present in this system, yet NGF mRNA could not be localized with in situ hybridization using radiolabeled riboprobes. Using fluorescent in situ RT-PCR, we can easily detect the presence of NGF mRNA and localize it to specific cell types within the maturing inner ear.


Asunto(s)
Factores de Crecimiento Nervioso/genética , Reacción en Cadena de la Polimerasa/métodos , ARN Mensajero/análisis , Animales , Secuencia de Bases , Expresión Génica , Masculino , Datos de Secuencia Molecular , Ratas
13.
Brain Res Mol Brain Res ; 50(1-2): 71-8, 1997 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-9406919

RESUMEN

Previous studies have shown that brain derived neurotrophic factor (BDNF) can protect auditory neurons from cisplatin toxicity in vitro. To explore the mechanism of BDNF mediated neuronal protection sequential confocal microscopic sampling of auditory neurons measured intracellular levels of reactive oxygen species (ROS) in response to withdrawal of BDNF supplementation, cisplatin exposure, and BDNF protection from cisplatin damage in normal and oxidative stress states. Additionally, we examined intraneuronal levels of the free radical scavenger glutathione (GSH) in response to withdrawal of BDNF. Withdrawal of BDNF resulted in increased production of ROS and decreased survival of auditory neurons. Levels of GSH within neurons increased after BDNF withdrawal, and this increase was shown to lag behind the production of ROS. Auditory neurons in cultures supplemented with BDNF and exposed to cisplatin showed significantly lower levels of ROS and increased survival compared to neurons in unprotected, cisplatin exposed cultures. Neurons treated with buthionine sulfoximine (an inhibitor of GSH synthesis), supplemented with BDNF, and exposed to cisplatin showed significantly higher intracellular levels of ROS compared to the neurons in BDNF supplemented cultures exposed to cisplatin. These results suggest that intracellular levels of ROS play an important role in cisplatin induced cell death of auditory neurons and that production of ROS can be ameliorated through supplementation with BDNF. GSH appears to mediate BDNF protection of these neurons from cisplatin induced ROS and subsequent damage.


Asunto(s)
Antineoplásicos/antagonistas & inhibidores , Vías Auditivas/efectos de los fármacos , Factor Neurotrófico Derivado del Encéfalo/farmacología , Cisplatino/antagonistas & inhibidores , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Animales , Antineoplásicos/toxicidad , Vías Auditivas/metabolismo , Butionina Sulfoximina/farmacología , Supervivencia Celular/efectos de los fármacos , Cisplatino/toxicidad , Glutatión/metabolismo , Microscopía Confocal , Neuronas/metabolismo , Ratas , Ratas Wistar , Especies Reactivas de Oxígeno/metabolismo , Ganglio Espiral de la Cóclea/citología , Ganglio Espiral de la Cóclea/efectos de los fármacos , Ganglio Espiral de la Cóclea/metabolismo
14.
Ann N Y Acad Sci ; 884: 171-91, 1999 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-10842593

RESUMEN

The pathologic similarities noted after ototoxic and/or traumatic injury to the cochlea as well as the key features of the cochlea that make it susceptible to reactive oxygen species (ROS) damage are reviewed. Recent evidence linking ROS to cochlear damage associated with both ototoxins and/or trauma are presented. Mechanisms of generation of ROS in the cochlea and how these metabolites damage the cochlea and impair function are also reviewed. Finally, examples of novel therapeutic strategies to prevent and reverse hearing loss due to noise and/or ototoxins are presented to illustrate the clinical relevance of these new findings.


Asunto(s)
Muerte Celular/fisiología , Sordera/metabolismo , Células Ciliadas Auditivas/fisiología , Pérdida Auditiva Provocada por Ruido/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Aminoglicósidos , Animales , Antibacterianos/efectos adversos , Antineoplásicos/efectos adversos , Antioxidantes/metabolismo , Antioxidantes/uso terapéutico , Muerte Celular/efectos de los fármacos , Cisplatino/efectos adversos , Sordera/inducido químicamente , Sordera/tratamiento farmacológico , Células Ciliadas Auditivas/efectos de los fármacos , Pérdida Auditiva Provocada por Ruido/tratamiento farmacológico
15.
Ann N Y Acad Sci ; 884: 345-60, 1999 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-10842605

RESUMEN

The application of gene therapy to the inner ear is an emerging field of study. Most studies report the expression of marker genes (e.g., galactosidase) within the tissues of the cochlea. The first biologic response of an inner ear tissue (i.e., auditory neurons) to transduction by a gene therapy vector expressing a therapeutic gene (a herpes amplicon vector containing a BDNF gene) was observed in spiral explants obtained from early postnatal rat cochleae. This study was important because it demonstrated the feasibility of a gene augmentation approach to treat traumatized cochleae. Long-term expression of transduced or transfected genes in cochlear tissues have been obtained with adenovirus, adeno-associated virus, and herpes amplicon vectors. The herpes amplicon vector (i.e., HSVbdnflac) that evoked a biologic response in vitro has also been successfully used to support the survival of auditory neurons in vivo following loss of the auditory hair cells (i.e., loss of trophic factor). Gene therapy has been successfully applied to the cochlea of a laboratory animal, and future studies will define the types of vectors and therapeutic genes that will work best for the treatment of inner ear diseases in the clinic.


Asunto(s)
Sordera/terapia , Oído Interno , Terapia Genética , Vectores Genéticos/uso terapéutico , Factores de Crecimiento Nervioso/uso terapéutico , Proteínas E1 de Adenovirus , Animales , Sordera/genética , Oído Interno/efectos de los fármacos , Predicción , Herpesvirus Humano 1 , Ratas , Ganglio Espiral de la Cóclea/efectos de los fármacos
16.
Neuroreport ; 2(6): 305-8, 1991 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-1655104

RESUMEN

Basic fibroblast growth factor (bFGF) has been shown to have neuronotrophic effects on cultured neurons. Transforming growth factor beta (TGFss1) has been implicated in the modulation of cellular receptors for bFGF in several cell types. In this study, we show that TGFss1 is expressed in cultured adult mouse auditory neurons in response to explanation injury and acts in an autocrine fashion to increase the level of expression of bFGF receptors message in these same neurons. Based on these in-vitro results, we propose that these trophic factors (i.e. TGFss1 and bFGF) play a significant role in the response to injury by the mature auditory system.


Asunto(s)
Receptores de Superficie Celular/fisiología , Factor de Crecimiento Transformador beta/fisiología , Animales , Secuencia de Bases , ADN sin Sentido/metabolismo , Ganglios/citología , Ganglios/fisiología , Ratones , Ratones Endogámicos CBA , Datos de Secuencia Molecular , Neuronas/citología , Neuronas/fisiología , Fosfopiruvato Hidratasa , ARN Mensajero/biosíntesis , ARN Mensajero/metabolismo , Receptores de Superficie Celular/genética , Receptores de Factores de Crecimiento de Fibroblastos
17.
Neuroreport ; 5(8): 865-8, 1994 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-8061284

RESUMEN

This study evaluates the trophic effects of three neurotrophins on traumatized adult auditory neurons in culture, and the presence of these neurotrophins in cochlear nucleus tissue. BDNF and NT-3 promoted survival but very limited neuritogenesis by adult auditory neurons in vitro, while NGF, although without a survival effect, evoked a robust neuritic outgrowth response when combined with BDNF. Messenger RNAs that encode for NGF, BDNF and NT-3 were detected by RT-PCR in RNA extracts from adult cochlear nuclei tissue. Based on these in vitro and in vivo findings, we propose NT-3 as the agent of the peripheral target-derived survival promoting effect and NGF, BDNF, and NT-3 as mediators of trophic influences originating from the central target (i.e. cochlear nucleus).


Asunto(s)
Factores de Crecimiento Nervioso/farmacología , Proteínas del Tejido Nervioso/farmacología , Neuritas/efectos de los fármacos , Neuronas Aferentes/efectos de los fármacos , Traumatismos del Nervio Vestibulococlear , Animales , Factor Neurotrófico Derivado del Encéfalo , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Núcleo Coclear/efectos de los fármacos , Núcleo Coclear/metabolismo , Peso Molecular , Factores de Crecimiento Nervioso/biosíntesis , Proteínas del Tejido Nervioso/biosíntesis , Neuritas/ultraestructura , Neuronas Aferentes/ultraestructura , Neurotrofina 3 , Reacción en Cadena de la Polimerasa , Ratas , Ratas Wistar , Nervio Vestibulococlear/citología
18.
Neuroreport ; 3(4): 295-8, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1325200

RESUMEN

Neuronotrophic factors (e.g. basic fibroblast growth factor, bFGF and nerve growth factor, NGF) have been demonstrated to respectively promote survival and neuritogenesis in cultures of dissociated adult rat spiral ganglia. Transforming growth factor beta (TGF beta 1) has been shown to modulate the response of cultured auditory neurons to bFGF through the induction of high affinity receptors for bFGF in the neurons. In this study, we show that TGF beta is expressed in situ by adult auditory neurons in response to traumatic injury (i.e. transection of the eighth cranial nerve). Based on these in vivo results and on the results from our previous in vitro studies, we propose that TFG beta 1 acts as an early autocrine signal involved in the response to injury by neurons of the peripheral auditor system.


Asunto(s)
Neuronas/fisiología , Factor de Crecimiento Transformador beta/genética , Nervio Vestibulococlear/fisiología , Animales , Sondas de ADN , ARN Mensajero/análisis , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas , Ratas Endogámicas , Receptores de Superficie Celular/metabolismo , Receptores de Factores de Crecimiento Transformadores beta , Factor de Crecimiento Transformador beta/biosíntesis
19.
Neuroreport ; 7(15-17): 2495-9, 1996 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-8981411

RESUMEN

CONFOCAL analysis of early postnatal auditory neurones in a bicompartmental culture system was used to test for chemoattractant properties of NGF, BDNF and NT-3 on neuronal process outgrowth. NT-3 exerted a strong tropic effect on neuritic outgrowth from auditory neurones in this system. BDNF and NGF did not have any tropic activity that directed processes outgrowth from auditory neurones. However, BDNF was important for the support of neuronal survival in NGF-treated cultures and for neuritogenesis in NT-3-treated cultures. Since NT-3 has been identified as both a survival factor and a chemotropic agent for auditory neurones, it is likely that this neurotrophin will be a useful therapeutic agent in the treatment of damaged cochleae for the recovery of hearing.


Asunto(s)
División Celular/efectos de los fármacos , Factores de Crecimiento Nervioso/farmacología , Nervio Vestibulococlear/fisiología , Animales , Animales Recién Nacidos/fisiología , Células Cultivadas , Técnicas In Vitro , Neurotrofina 3 , Ratas , Ratas Wistar
20.
Neuroreport ; 7(4): 889-94, 1996 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-8724667

RESUMEN

Destruction of auditory hair cells results in a subsequent loss of auditory neurons. In situ hybridization and neuronal cell culture studies as well as analyses of the inner ears of neurotrophin and neurotrophin receptor gene knockout mice have shown that NT-3 and BDNF mediate both the development and survival of auditory neurons. In this study guinea pigs were exposed to the ototoxic combination of an aminoglycoside antibiotic and a loop diuretic and then received 8 weeks of intracochlear infusion of either NT-3, BDNF or NT-3 + BDNF to determine whether site-specific application of these neurotrophins could prevent the loss of auditory neurons that follows a loss of auditory hair cells. Infusion of either NT-3 or NT-3 + BDNF into the scala tympani resulted in a > 90% survival of auditory neurons while BDNF infusion yielded a 78% survival rate, compared with a 14-24% neuronal survival rate in untreated ototoxin-exposed cochleae. These results show that loss of auditory neurons that occurs subsequent to a loss of auditory hair cells can be prevented by in vivo neurotrophin therapy with either NT-3 or BDNF.


Asunto(s)
Vías Auditivas/efectos de los fármacos , Factor Neurotrófico Derivado del Encéfalo/uso terapéutico , Células Ciliadas Auditivas/efectos de los fármacos , Factores de Crecimiento Nervioso/uso terapéutico , Neuronas/efectos de los fármacos , Animales , Vías Auditivas/citología , Recuento de Células/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Cóclea/citología , Cóclea/efectos de los fármacos , Cobayas , Neurotrofina 3 , Ganglio Espiral de la Cóclea/citología , Ganglio Espiral de la Cóclea/efectos de los fármacos
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