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1.
J Orofac Orthop ; 75(3): 226-39, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24825834

RESUMEN

BACKGROUND: Primary failure of eruption (PFE) may be associated with pathogenic mutations in the PTHR1 gene. It has numerous manifestations and is characterized by severe posterior open bite. However, there are also phenotypically similar types of eruption anomalies not associated with a known pathogenic PTHR1 mutation. The purpose of this study was to evaluate whether a distinction can be made between PTHR1-mutation carriers and noncarriers based on clinical and radiological findings. PATIENTS AND METHODS: A total of 36 patients with suspected PFE diagnoses were included and analyzed in accordance with specific clinical and radiographic criteria. In addition, all patients underwent Sanger DNA sequencing analysis of all coding sequences (and the immediate flanking intronic sequences) of the PTHR1 gene. RESULTS: Of these patients, 23 exhibited a heterozygous pathogenic mutation in the PTHR1 gene (PTHR1-mutation carriers), while molecular genetic analysis revealed nosequence alteration in the other 13 patients (non-PTHR1-mutation carriers). Relevant family histories were obtained from 5 patients in the carrier group; hence, this group included a total of 13 familial and 10 simplex cases. The group of noncarriers revealed no relevant family histories. All patients in the carrier group met six of the clinical and radiographic criteria explored in this study: (1) posterior teeth more often affected; (2) eruption disturbance of an anterior tooth in association with additional posterior-teeth involvement; (3) affected teeth resorbing the alveolar bone located coronal to them; (4) involvement of both deciduous and permanent teeth; (5) impaired vertical alveolar-process growth; and (6) severe subsequent finding of posterior open bite. None of the analyzed criteria were, by contrast, met by all patients in the noncarrier group. All patients in the carrier group could be assigned to one of three classifications indicating the extent of eruption disturbance, whereas 4 of the 13 noncarriers presented none of these three patterns. The clinical and radiographic criteria employed in this study would have correctly identified 10 of the 13 PFE patients in the noncarrier group as possessing no detectable PTHR1 mutation. CONCLUSION: The evaluation of clinical and radiographic characteristics can heighten the specificity of ruling out suspected PTHR1 involvement in PFE patients. A hereditary element of PTHR1-associated PFE is clearly identifiable. More studies with more patients are needed to optimize the sensitivity of this preliminary approach on the differential identification of PTHR1-mutation carriers versus noncarriers by multivariate analysis.


Asunto(s)
Predisposición Genética a la Enfermedad/genética , Técnicas de Diagnóstico Molecular/métodos , Radiografía Dental/métodos , Receptor de Hormona Paratiroídea Tipo 1/genética , Enfermedades Dentales/diagnóstico por imagen , Enfermedades Dentales/genética , Adolescente , Niño , Diagnóstico Diferencial , Femenino , Marcadores Genéticos/genética , Humanos , Masculino , Mutación/genética , Variaciones Dependientes del Observador , Polimorfismo de Nucleótido Simple/genética , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Adulto Joven
2.
Neuropediatrics ; 41(1): 30-4, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20571988

RESUMEN

Mitochondrial NADH: ubiquinone oxidoreductase (complex I) deficiency accounts for most defects in mitochondrial oxidative phosphorylation. Pathogenic mutations have been described in all 7 mitochondrial and 12 of the 38 nuclear encoded subunits as well as in assembly factors by interfering with the building of the mature enzyme complex within the inner mitochondrial membrane. We now describe a male patient with a novel homozygous stop mutation in the NDUFAF2 gene. The boy presented with severe apnoea and nystagmus. MRI showed brainstem lesions without involvement of basal ganglia and thalamus, plasma lactate was normal or close to normal. He died after a fulminate course within 2 months after the first crisis. Neuropathology verified Leigh disease. We give a synopsis with other reported patients. Within the clinical spectrum of Leigh disease, patients with mutations in NDUFAF2 present with a distinct clinical pattern with predominantly brainstem involvement on MRI. The diagnosis should not be missed in spite of the normal lactate and lack of thalamus and basal ganglia changes on brain MRI.


Asunto(s)
Tronco Encefálico/patología , Complejo I de Transporte de Electrón/deficiencia , Enfermedad de Leigh/metabolismo , Enfermedad de Leigh/patología , Proteínas Mitocondriales/deficiencia , Análisis Mutacional de ADN/métodos , Fibroblastos/enzimología , Humanos , Lactante , Imagen por Resonancia Magnética/métodos , Masculino , Chaperonas Moleculares , Músculo Esquelético/enzimología , Mutación/genética
3.
Nervenarzt ; 80(2): 184-9, 2009 Feb.
Artículo en Alemán | MEDLINE | ID: mdl-19194685

RESUMEN

BACKGROUND: Telemedicine is increasingly used for acute stroke care, making neurological expertise available in nonspecialized hospitals. There are few data about telemedicine's acceptance by either medical staff or patients at treating hospitals. METHODS: Telemedicine's acceptance was evaluated in the Telemedical Project for Integrative Stroke Care (TEMPIS), a network of two stroke centers and 12 community hospitals in the German state of Bavaria; the grading of teleconsultation regarding video and audio quality, time consumption, and medical relevance was assessed in two periods, 2004 and 2007. Overall satisfaction with in-hospital treatment was compared between patients in telemedically-linked hospitals with specialized stroke care and patients treated in conventional community hospitals. With regard to sufficient follow-up rates, ratings were restricted to patients living at home without severe disability at 3 months after stroke. A second evaluation analyzed how the parameter "Telemedical assessment of patient" (36% of patients in TEMPIS hospitals) affected overall satisfaction. RESULTS: Respectively, 140 and 127 uses of telemedicine were assessed in the two evaluation periods. Video quality, time consumption, and medical relevance were graded "excellent" by over 50% in both periods. Audio quality was rated "excellent" by only 22% in the first period but 69% in the second. Excellent overall satisfaction was expressed significantly more frequently by patients at TEMPIS hospitals (total number 1044) than by those at control hospitals (total number 484; 56% vs 47% respectively, P<0.01). Patient consultation via telemedicine per se did not correlate with modified grading. CONCLUSIONS: Acceptance of telemedicine in acute stroke care was high and stable over a long period. This study suggests improved overall satisfaction with treatment in hospitals offering specialized care and linked via telemedicine. Clinical assessment via telemedicine had no major effect on satisfaction.


Asunto(s)
Actitud del Personal de Salud , Aceptación de la Atención de Salud/estadística & datos numéricos , Satisfacción del Paciente/estadística & datos numéricos , Garantía de la Calidad de Atención de Salud , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/terapia , Telemedicina/estadística & datos numéricos , Alemania , Humanos , Accidente Cerebrovascular/epidemiología
4.
Genes Brain Behav ; 5(1): 46-52, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16436188

RESUMEN

The neural cell adhesion molecule (NCAM) plays important roles in development of the nervous system and in synaptic plasticity and memory formation in the adult. The present study sought to further investigate the role of NCAM in learning by testing habituation and footshock sensitization learning of the startle response (SR) in NCAM null mutant (NCAM-/-) and wildtype littermate (NCAM+/+) mice. Whereas habituation is a form of non-associative learning, footshock sensitization is induced by rapid contextual fear conditioning. Habituation was tested by repetitive presentation of acoustic and tactile startle stimuli. Although NCAM-/- mice showed differences in sensitivity in both stimulus modalities, habituation learning was intact in NCAM-/- mice, suggesting that NCAM does not play a role in the mechanisms underlying synaptic plasticity in the startle pathway. Footshock sensitization was elicited by presentation of electric footshocks between two series of acoustic stimuli. In contrast to habituation, footshock sensitization learning was attenuated in NCAM-/- mice: the acoustic SR increase after the footshocks was lower in the mutant than in wildtype mice, indicating that NCAM plays an important role in the relevant brain areas, such as amygdala and/or the hippocampus.


Asunto(s)
Aprendizaje por Asociación/fisiología , Habituación Psicofisiológica/fisiología , Moléculas de Adhesión de Célula Nerviosa/fisiología , Reflejo de Sobresalto/fisiología , Estimulación Acústica , Animales , Umbral Auditivo/fisiología , Condicionamiento Operante/fisiología , Femenino , Habituación Psicofisiológica/genética , Audición/genética , Audición/fisiología , Ratones , Ratones Noqueados , Moléculas de Adhesión de Célula Nerviosa/genética , Plasticidad Neuronal/genética , Plasticidad Neuronal/fisiología , Reflejo de Sobresalto/genética , Tacto/genética , Tacto/fisiología
5.
Genes Brain Behav ; 1(3): 178-86, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12884974

RESUMEN

The inbred mouse strain BALB has been proposed to be an animal model for pathological anxiety. BALB exhibits a stronger acoustic startle response (ASR) than the 'less emotional' inbred strain DBA. Four experiments were conducted to determine whether this strong ASR is due to a higher anxiety level and/or to greater sensitization in BALB than in DBA, with the following results: (1) The ASR to the very first startle stimulus was found to be much stronger in BALB than in DBA, and freezing behavior evoked by startle stimuli was more pronounced in BALB than in DBA. These findings indicate a higher level of anxiety in this strain. (2) ASR amplitudes of BALB initially rose much higher during consecutive startle stimuli and remained at a high level much longer than in DBA. Thereafter, ASR amplitude dropped more slowly and to a lesser degree than in DBA. Startle amplitudes decreased similarly in both strains (strong exponential decrease) only when a low sound pressure level (SPL) was used which elicited approximately the same low ASR in both strains. These results can only be explained by increased sensitization in BALB. (3) The slope of the i/o-function, which represents the relation between sensory input and motor output, was steeper in BALB than in DBA. As it has been shown recently, sensitization increases the slope of the startle i/o-function indicating increased sensitization in BALB. It is discussed, however, whether anxiety also contributes to this effect. (4) Footshocks increased the ASR much less in BALB than in DBA, again showing increased sensitization in BALB. Both a higher level of anxiety and greater sensitization therefore determined the greater strength of the ASR in BALB than in DBA.


Asunto(s)
Nivel de Alerta/genética , Encéfalo/fisiología , Habituación Psicofisiológica/genética , Ratones Endogámicos BALB C/genética , Ratones Endogámicos DBA/genética , Reflejo de Sobresalto/genética , Estimulación Acústica , Animales , Nivel de Alerta/fisiología , Electrochoque , Femenino , Habituación Psicofisiológica/fisiología , Masculino , Ratones , Fenotipo , Reflejo de Sobresalto/fisiología , Espectrografía del Sonido , Especificidad de la Especie
6.
Behav Brain Res ; 125(1-2): 183-8, 2001 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11682109

RESUMEN

One current approach in investigating the neural basis of behavior is to use mutant mice with specific genetic alterations which affect neural functions. We are convinced that this approach is only effective if a behavioral model with sufficiently known underlying neuronal mechanisms is used. We present a model system which is well-suited for the above approach. Because the neural basis is known in great detail, in the startle system behavioral results can be very well interpreted. This is demonstrated here by using footshock sensitization of the acoustic startle response (ASR) as an example. Sensitization is elicited by aversive stimuli such as electric footshocks and causes an increase in ASR amplitude. The present experiment showed that this ASR increase is not due to a drop in the startle threshold but to increased gain in the response to suprathreshold stimuli. This makes it possible to draw conclusions about the neuronal site of the startle threshold in the startle pathway and the synapse at which the gain shift during sensitization occurs. The possibility of interpreting behavioral output on a well known neural basis (as demonstrated here) makes the ASR a promising model system for investigating (neuro-) genetic influences of behavior.


Asunto(s)
Nivel de Alerta/genética , Encéfalo/fisiología , Fenotipo , Reflejo de Sobresalto/genética , Amígdala del Cerebelo/fisiología , Animales , Variación Genética , Ratones , Ratones Endogámicos/genética , Especificidad de la Especie
7.
Hum Pathol ; 32(10): 1136-40, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11679949

RESUMEN

We report a 52-year-old woman who underwent otoneurosurgery to resect acoustic neurinoma. Bone reconstruction was performed with an aluminium (Al)-containing cement. Six weeks later the patient suffered from loss of consciousness, myoclonic jerks, and persistent grand mal seizures, clinical symptoms that resembled those of lethal dialysis encephalopathy of the 1960s and 1970s. She died 6 months later because of septic complications. Light- and electron-microscopic investigation of the central nervous system (CNS) showed pathognomonic Al-containing intracytoplasmic argyrophilic inclusions in choroid plexus epithelia, neurons, and cortical glia. These changes are characteristics of dialysis-associated encephalopathy (DAE), induced nowadays by long-term ingestion of Al-containing drugs (and with benign clinical courses). Atomic absorption spectrometry showed an increase of mean bulk Al concentration of the cortex and subcortex up to 9.3 microg/g (normal range <2 microg/g); laser microprobe showed the increase of Al in subcellular structures. This unique case again shows the extraordinary neurotoxicity of Al, which was, in our patient, initiated by an amount of about 30 mg Al and apparently caused by direct Al access to the brain parenchyma via a cerebrospinal fluid leakage.


Asunto(s)
Aluminio/envenenamiento , Encefalopatías/inducido químicamente , Oído Interno/cirugía , Complicaciones Posoperatorias , Aluminio/análisis , Silicatos de Aluminio/efectos adversos , Silicatos de Aluminio/química , Materiales Biocompatibles/efectos adversos , Materiales Biocompatibles/química , Cementos para Huesos/efectos adversos , Cementos para Huesos/química , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Encéfalo/patología , Química Encefálica , Encefalopatías/patología , Resultado Fatal , Femenino , Cementos de Ionómero Vítreo/efectos adversos , Humanos , Persona de Mediana Edad , Convulsiones/etiología
8.
Epilepsia ; 42(7): 950-3, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11488899

RESUMEN

We report a patient with early infantile epileptic encephalopathy (EIEE) with suppression-burst (Ohtahara syndrome) associated with olivary-dentate dysplasia and agenesis of mamillary bodies is reported. Although those with Ohtahara syndrome are a heterogeneous group, virtually all reported cases are secondary to neuronal migrational disorders, sometimes only identified by detailed neuropathologic examination, as in this case report, which describes mamillary body agenesis as a not-yet-recognized anomaly associated with Ohtahara syndrome. All children with Ohtahara syndrome should have high-resolution magnetic resonance imaging (MRI) and detailed postmortem neuropathologic examinations.


Asunto(s)
Núcleos Cerebelosos/anomalías , Epilepsia/diagnóstico , Epilepsia/patología , Tubérculos Mamilares/anomalías , Núcleo Olivar/anomalías , Núcleos Cerebelosos/patología , Corteza Cerebral/anomalías , Corteza Cerebral/patología , Electroencefalografía/estadística & datos numéricos , Humanos , Lactante , Recién Nacido , Imagen por Resonancia Magnética/estadística & datos numéricos , Tubérculos Mamilares/patología , Malformaciones del Sistema Nervioso/diagnóstico , Malformaciones del Sistema Nervioso/patología , Núcleo Olivar/patología , Espasmos Infantiles/diagnóstico , Espasmos Infantiles/patología , Síndrome , Tomografía Computarizada de Emisión de Fotón Único/estadística & datos numéricos
9.
Onkologie ; 24(1): 66-72, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11441284

RESUMEN

BACKGROUND: The development of a secondary neoplasm in childhood cancer survivors attains growing importance due to the reported excellent survival and therefore the long exposure to potentially carcinogenic effects of treatment. CASE REPORT: We report a 14-year-old girl in whom a large craniopharyngioma (CP) was diagnosed. After surgery, radiation therapy (RT) was given for residual tumour. Discrete progression necessitated further surgery, resulting in permanent tumour control. Soon after the second surgery hypothalamic-pituitary dysfunction developed together with obesity. Supportive hormone therapy was initiated. Growth hormone (GH) therapy was also given for 15 months. Four years after the diagnosis, a cerebropontine anaplastic astrocytoma WHO grade III was detected, with the main lesion being at the dorsal edge of the irradiated area. The girl died 1 month later from this secondary presumably radiation-induced tumour. Only recently a second child with RT for a CP was diagnosed with malignant glioma in our hospital. CASE REPORTS IN THE LITERATURE: 12 other cases of malignant glioma have been reported after RT for CP. Including our present cases, the mean latency period was 10.7 years (median 9.6 years). However, the shortest latency periods were found in patients who had received GH therapy. In numerous cases, the secondary tumour was seen at the edge of the irradiated volume, and not in the region with the highest absorbed dose. CONCLUSIONS: Therapy-induced secondary gliomas after treatment of CP or other intracranial tumours are rare but dramatic late events with a very poor prognosis. Including our own 2 patients, we reviewed 14 cases of CP with occurrence of a secondary, probably radiation-induced malignant glioma. The short latency periods for patients treated with GH is remarkable. We therefore suspect that GH therapy may accelerate the development of a secondary brain tumour. We are reluctant to recommend GH therapy in conventionally irradiated CP patients. In order to seriously answer the questions about therapy-induced secondary neoplasms, a life-long follow-up is mandatory for all patients who are survivors of childhood cancer.


Asunto(s)
Astrocitoma/diagnóstico , Neoplasias del Tronco Encefálico/diagnóstico , Neoplasias Cerebelosas/diagnóstico , Craneofaringioma/radioterapia , Neoplasias Inducidas por Radiación/diagnóstico , Neoplasias Primarias Secundarias/diagnóstico , Irradiación Hipofisaria , Neoplasias Hipofisarias/radioterapia , Adolescente , Cerebelo/patología , Terapia Combinada , Craneofaringioma/cirugía , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Neoplasias Hipofisarias/cirugía , Puente/patología , Radioterapia Adyuvante
10.
Behav Brain Res ; 121(1-2): 57-67, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11275284

RESUMEN

The spontaneous mutant mouse spasmodic (spd) carries a missense mutation affecting the glycine receptor alpha1-subunit gene. This results in a decreased binding affinity to glycine. Spd mutants show exaggerated acoustic startle responses (ASR). The present study sought to elucidate whether this increased ASR is due to a changed auditory processing or to stronger motor output resulting from a disinhibited motor system or, alternatively, to changes in modulatory influences on the startle pathway, namely in the mechanisms underlying habituation and sensitization. We found that in homozygous spd/spd mutants the startle threshold was lower, and the recorded slope of input/output (i/o) function, which reflects the relation between sensory input and motor output, was steeper. During repetitive presentation of high sound pressure level (SPL) startle stimuli (25 dB above startle threshold), ASR amplitudes did not decrease in spd/spd mutants as they do in the wildtype. In contrast, ASR amplitudes decreased when low SPL startle stimuli were presented. Footshocks presented after high SPL startle stimuli did not cause a further increase in ASR amplitudes of spd/spd mutants as in the wildtype. In heterozygous spd/+ mutants all these parameters were between those of spd/spd mutants and wildtype mice but closer to those of the wildtype. The steeper slope of i/o function in spd/spd mutants may be caused by both an increased sensory input and an increased motor output. The altered course of ASR amplitudes during repetitive stimulation and the deficit in additional footshock sensitization, however, can only be explained by an increased sensitization level in the spd/spd mutants. In accordance with the "dual process theory" strong sensitization evoked by high SPL startle stimuli supposedly counteracts habituation, leading to a constant high ASR amplitude. Furthermore, additional footshock sensitization is prevented. The increased sensitization level may be due to a change in auditory processing leading to a stronger sensitizing effect of the startle stimuli with high SPL. Alternatively, glycinergic tonic inhibition of sensitizing structures (e.g. the amygdala) in the wildtype may be diminished in spd/spd mutants, thus leading to a high sensitization level.


Asunto(s)
Nivel de Alerta/genética , Mutación Missense/genética , Receptores de Glicina/genética , Reflejo de Sobresalto/fisiología , Estimulación Acústica , Animales , Electrochoque , Miedo/fisiología , Femenino , Genotipo , Habituación Psicofisiológica/fisiología , Heterocigoto , Masculino , Ratones , Ratones Mutantes Neurológicos , Fenotipo
11.
Ann Neurol ; 48(3): 372-6, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10976644

RESUMEN

We report on the pathological findings in the brains of 8 Parkinson's disease patients treated with deep brain stimulation (DBS) of the thalamic ventral intermediate nucleus (6 cases) and subthalamic nucleus (2 cases). DBS was performed continuously for up to 70 months. All brains showed well-preserved neural parenchyma and only mild gliosis around the lead track compatible with reactive changes due to surgical placement of the electrode. We conclude that chronic DBS does not cause damage to adjacent brain tissue.


Asunto(s)
Encéfalo/patología , Terapia por Estimulación Eléctrica/efectos adversos , Enfermedad de Parkinson/patología , Humanos , Enfermedad de Parkinson/terapia , Factores de Tiempo
12.
Behav Brain Res ; 108(2): 181-8, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10701661

RESUMEN

The acoustic startle response (ASR) in rats is mediated by an oligosynaptic pathway from the cochlea via the brainstem to spinal and cranial motoneurons. The present study tested whether the superior olivary complex (SOC) plays a role in the mediation of the ASR. The SOC receives auditory information from the ventral cochlear nuclei and projects to the caudal pontine reticular nucleus (PnC), the sensorimotor interface of the ASR. Axon-sparing excitotoxic lesions of the SOC strongly reduced the ASR amplitude and slightly prolonged ASR onset and peak latencies. The integrity of PnC which is adjacent to the SOC was confirmed by testing the tactile startle response which was not affected by SOC lesions. We suggest that the SOC is necessary for a full expression of the ASR and discuss possible auditory input structures involved in the mediation of the ASR.


Asunto(s)
Estimulación Acústica , Red Nerviosa/fisiología , Neuronas Aferentes/fisiología , Núcleo Olivar/fisiología , Reflejo de Sobresalto/fisiología , Tacto , Animales , Tronco Encefálico/fisiología , Antagonistas de Aminoácidos Excitadores/efectos adversos , Ácido Iboténico/efectos adversos , Núcleo Olivar/lesiones , Ratas , Ratas Sprague-Dawley , Periodo Refractario Electrofisiológico/fisiología
13.
Brain Pathol ; 9(4): 617-26, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10517500

RESUMEN

Chordoid glioma of the third ventricle was recently reported as a novel tumor entity of the central nervous system with characteristic clinical and histopathological features (Brat et al., J Neuropathol Exp Neurol 57: 283-290, 1998). Here, we report on a histopathological, immunohistochemical and molecular genetic analysis of five cases of this rare neoplasm. All tumors were immunohistochemically investigated for the expression of various differentiation antigens, the proliferation marker Ki-67, and a panel of selected proto-oncogene and tumor suppressor gene products. These studies revealed a strong expression of GFAP, vimentin, and CD34. In addition, most tumors contained small fractions of neoplastic cells immunoreactive for epithelial membrane antigen, S-100 protein, or cytokeratins. The percentage of Ki-67 positive cells was generally low (<5%). All tumors showed immunoreactivity for the epidermal growth factor receptor and schwannomin/merlin. There was no nuclear accumulation of the p53, p21 (Waf-1) and Mdm2 proteins. To examine genomic alterations associated with the development of chordoid gliomas, we screened 4 tumors by comparative genomic hybridization (CGH) analysis. No chromosomal imbalances were detected. More focussed molecular genetic analyses revealed neither aberrations of the TP53 and CDKN2A tumor suppressor genes nor amplification of the EGFR, CDK4, and MDM2 proto-oncogenes. Our data strongly support the hypothesis that chordoid glioma of the third ventricle constitutes a novel tumor entity characterized by distinct morphological and immunohistochemical features, as well as a lack of chromosomal and genetic alterations commonly found in other types of gliomas or in meningiomas.


Asunto(s)
Neoplasias del Plexo Coroideo/genética , Glioma/genética , Adulto , Anciano , Neoplasias del Plexo Coroideo/patología , Femenino , Eliminación de Gen , Genes p16/genética , Glioma/patología , Humanos , Inmunohistoquímica , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Hibridación de Ácido Nucleico , Reacción en Cadena de la Polimerasa , Polimorfismo Conformacional Retorcido-Simple , Proto-Oncogenes Mas , Tercer Ventrículo/patología , Tomografía Computarizada por Rayos X
14.
Behav Brain Res ; 103(2): 195-201, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10513587

RESUMEN

Sensitization is the general increase of responsiveness observed after aversive stimulation. Usually footshocks are used as aversive stimuli. According to the 'Dual Process Theory' by Groves and Thompson. Psychol. Rev. 1970;77:419-450, not only additional aversive stimuli but also the response-eliciting stimuli themselves have a sensitizing effect, the degree of sensitization depending upon the stimulus intensity. We tested this suggestion in the footshock sensitization paradigm of the acoustic startle response (ASR): (1) High SPL (sound pressure level) acoustic stimuli (119 dB SPL) presented instead of footshocks also elicited strong sensitization. (2) While footshocks presented after startle stimuli with low SPL (95 dB) were able to produce a strong further sensitization of the ASR, footshocks presented after startle stimuli with high SPL (110 dB) only caused a minor sensitization of the ASR. (3) Diazepam (3 mg/kg i.p.) decreased ASR to high SPL (115 dB) stimuli. In this case footshocks elicited significant sensitization of the ASR despite intense startle stimuli. The present results support the 'Dual Process Theory'. Furthermore we could show that acoustic and footshock sensitization interact. We therefore suggest that both, acoustic and footshock sensitization, are mediated partly via the same neural circuitry.


Asunto(s)
Reflejo de Sobresalto/fisiología , Estimulación Acústica , Animales , Ansiolíticos/farmacología , Diazepam/farmacología , Estimulación Eléctrica , Electrochoque , Masculino , Ratas , Ratas Sprague-Dawley
15.
Behav Genet ; 29(1): 59-63, 1999 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10371759

RESUMEN

An increase in general responsiveness after aversive stimulation has provided a most widely accepted and well-understood sensitization paradigm. According to a second paradigm (based on the dual process theory of habituation and sensitization), not only additional aversive stimuli, but also the response-eliciting stimuli themselves, induce sensitization. To relate these two sensitization paradigms, we compared the course of startle response parameters during repetitive acoustic stimulation with the change in startle amplitude after electric footshocks in outbred Wistar and Sprague-Dawley rats. Compared to the Wistar rats used, the Sprague-Dawley rats showed a lower response decrement and a shortened latency during repetitive stimulation, both of which are indicators of increased sensitization by the startle-eliciting stimuli. In addition, the Sprague-Dawley rats also demonstrated a reduced increase in startle amplitude following footshock. This was postulated to be a consequence of the strong sensitization by startle-eliciting stimuli, which interferes with sensitization elicited by footshock. Because our Wistar and Sprague-Dawley rats did not differ in initial startle amplitude, but mainly in susceptibility to sensitization, further comparisons of these genetically different stocks of rats seem to be of potential value in studying differences in fear-motivated behavior.


Asunto(s)
Habituación Psicofisiológica/genética , Reflejo de Sobresalto/genética , Temperamento/fisiología , Estimulación Acústica , Análisis de Varianza , Animales , Condicionamiento Psicológico/fisiología , Intervalos de Confianza , Electrochoque/efectos adversos , Masculino , Ratas , Ratas Sprague-Dawley , Ratas Wistar , Factores de Tiempo
16.
Wien Med Wochenschr ; 148(4): 101-6, 1998.
Artículo en Alemán | MEDLINE | ID: mdl-9611350

RESUMEN

Between 1969 and 1996, transmissible spongiform encephalopathy was definitely diagnosed by autopsy and/or biopsy in 98 Austrian patients. The yearly incidence increased significantly in past years (1996: 1.41 cases per million inhabitants). This increase likely results from increased awareness in the medical community and effectuation of the diagnostic autopsy. The new variant of Creutzfeldt-Jakob disease (CJD), probably transmitted from bovine spongiform encephalopathy (BSE), has not occurred in Austria. The percentage of patients older than 70 years increased until 1989 and declined slightly thereafter. One patient received a dura mater graft 11 years before death. Another patient had familial CJD with a glutamatelysin mutation on codon 200 of the prion protein (PrP) gene PRNP. One more patient died from Gerstmann-Sträussler-Scheinker disease (GSS), three patients from fatal familial insomnia (FFI). Another patient received intramuscular injections of a purified RNA preparation (Regeneresen) produced from various organs including brain. The age at death symmetrically distributes around a median of 64 years. Two CJD patients were unusually young (27 and 30 years). Most patients (72.7%) died within 6 months of disease. Retrospectively, 81% of patients had clinical diagnostic criteria of probable or possible CJD (52% probably and 29% possible). In 19%, clinical criteria for CJD were not fully met. There is no case clustering with specific professional groups or geographic areas. However, residents of Vienna, or Vienna and Lower Austria, respectively, had CJD diagnosed twice or three times more frequently than the rest of the country, indicating regionally differing qualities of case retrieval.


Asunto(s)
Enfermedades por Prión/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Austria/epidemiología , Encéfalo/patología , Bovinos , Causalidad , Estudios Transversales , Femenino , Humanos , Enfermedad Iatrogénica , Incidencia , Masculino , Persona de Mediana Edad , Enfermedades por Prión/genética , Enfermedades por Prión/patología , Enfermedades por Prión/transmisión , Factores de Riesgo
17.
Hear Res ; 105(1-2): 171-82, 1997 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9083814

RESUMEN

The effect of the acoustic middle ear reflex (MER) was quantified using electrodes chronically implanted in the middle ears of rats. Cochlear microphonics (CM) and middle ear muscle EMG were measured under light Ketamin anesthesia after stimulation with tone pulses of 5-20 kHz ranging between 75 and 120 dB SPL. With increasing intensity, the CM measured before the onset of the MER increased to a maximum amplitude and then decreased with higher SPLs. At 10 kHz this maximum was reached at 95 dB SPL, for other stimulus frequencies at higher SPLs. After a latency of 10-20 ms, CM to 10 kHz stimuli of 80-95 dB SPL were decreased by the attenuating action of the MER. The lowest threshold of the MER was also measured at 10 kHz (77 dB SPL in the mean). To stimuli greater than 100 dB SPL after a latency of 6-10 ms, the CM amplitude was increased. That this CM increase to intense stimuli is caused by the action of the MER was confirmed by control experiments such as cutting the tendons of the middle ear muscles. The CM decrease to stimuli below 100 dB SPL, as well as the increase to very intense stimuli, can be explained by sound attenuation caused by the MER, together with the nonlinear dependence of CM amplitude on stimulus level. The observed shift of the maxima of the CM input-output function by the MER to higher stimulus levels probably indicates an increase of the dynamic range of the ear.


Asunto(s)
Cóclea/fisiología , Potenciales Microfónicos de la Cóclea/fisiología , Oído Medio/fisiología , Reflejo Acústico/fisiología , Estimulación Acústica , Animales , Umbral Auditivo/fisiología , Electrodos Implantados , Electromiografía , Femenino , Ratas , Ratas Sprague-Dawley , Estapedio/fisiología
18.
J Neuroimaging ; 7(1): 50-4, 1997 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9038434

RESUMEN

A 61-year-old woman had Creutzfeldt-Jakob disease, type Heidenhain, that progressed for 4 months until death, 3 of which she spent in a hospital. The diagnosis was verified by autopsy. Consecutive brain computed tomography, magnetic resonance imaging, blood flow measurements, electroencephalography (EEG), and routine laboratory tests were performed. All imaging techniques showed nonspecific pathological changes, whereas EEG revealed alterations indicative for Creutzfeldt-Jakob disease.


Asunto(s)
Síndrome de Creutzfeldt-Jakob/diagnóstico , Imagen por Resonancia Magnética , Tomografía Computarizada de Emisión de Fotón Único , Tomografía Computarizada por Rayos X , Encéfalo/patología , Síndrome de Creutzfeldt-Jakob/patología , Diagnóstico Diferencial , Electroencefalografía , Femenino , Humanos , Persona de Mediana Edad , Priones/análisis
19.
Behav Genet ; 27(6): 579-82, 1997 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9476367

RESUMEN

To investigate the emotional reactions of two rat strains selectively bred for good and poor two-way avoidance acquisition (RHA/Verh and RLA/Verh), male animals of both strains were tested in an acoustic startle response test. They received 40 acoustic stimuli followed by 10 electric foot shocks and another 30 acoustic stimuli. RLA/Verh rats showed a significantly higher startle response compared to RHA/Verh animals, indicating a stronger emotional reaction to acoustic stimuli. In addition, the former showed a stronger response to foot shocks. Combined with earlier findings, we conclude that selection for two-way avoidance learning does not result in cognitive defects in the RLA/Verh strain but, rather, in stronger emotional reactions to fearful stimuli.


Asunto(s)
Estimulación Acústica , Ratas Endogámicas/psicología , Reflejo de Sobresalto/genética , Animales , Reacción de Prevención , Masculino , Ratas , Ratas Endogámicas/genética
20.
Wien Klin Wochenschr ; 108(23): 759-63, 1996 Dec 13.
Artículo en Alemán | MEDLINE | ID: mdl-9092208

RESUMEN

Between 1969 and 30th June 1996, Creutzfeldt-Jakob disease (CJD) was definitively diagnosed in 88 Austrian patients by autopsy and/or biopsy. The number of diagnosed cases has steadily increased in recent years (average incidence in 1969-1985: 0.18 per million; 1986-1994: 0.67 per million; 1995: 1.25 per million; estimate for 1996: 1.7 per million). The percentage of patients older than 70 years increased until 1989 and has decreased slightly since then. One patient received a lyophilised dura transplant 11 years before death. Another patient gave a history of intramuscular injections of bovine RNA (Regeneresen) extracted from various organs including brain administered over a ten-year period. One female patient had familial CJD with a glutamate-->lysine mutation at codon 200 of the prion protein (PrP) gene PRNP. The ages at death are distributed symmetrically around the median of 64 years. Two female patients died at the unusually young ages of 27 and 30 years. Median duration of disease was 4.5 months; 77% of the patients died within 6 months after onset of the disease. Retrospectively, 83% of the patients fulfilled the clinical criteria of probable or possible CJD. Neuropathologically, each patient showed accumulation of immunocytochemically detectable pathological PrP in the central nervous system. No patient had the neuropathological profile of the new CJD variant recently described in the U.K. The recent rise in diagnosed CJD in Austria probably reflects increased awareness and recognition rather than a real increase. Since bovine spongiform encephalopathy (BSE) has not been observed in Austria, our data argue against an association between the rise of incidence of CJD and BSE.


Asunto(s)
Síndrome de Creutzfeldt-Jakob/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Animales , Austria/epidemiología , Encéfalo/patología , Bovinos , Síndrome de Creutzfeldt-Jakob/diagnóstico , Síndrome de Creutzfeldt-Jakob/genética , Estudios Transversales , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo
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