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Neuroinflammation has been proposed to impact symptomatology in patients with schizophrenia spectrum disorders. While previous studies have shown equivocal effects of treatments with add-on anti-inflammatory drugs such as Aspirin, N-acetylcysteine and Celecoxib, none have used a subset of prospectively recruited patients exhibiting an inflammatory profile. The aim of the study is to evaluate the efficacy and safety as well as the cost-effectiveness of a treatment with 400 mg Celecoxib added to an ongoing antipsychotic treatment in patients with schizophrenia spectrum disorders exhibiting an inflammatory profile. The "Add-on Celecoxib treatment in patients with schizophrenia spectrum disorders and inflammatory cytokine profile trial (TargetFlame)" is a multicentre randomized, placebo-controlled phase III investigator-initiated clinical trial with the following two arms: patients exhibiting an inflammatory profile receiving either add-on Celecoxib 400 mg/day or add-on placebo. A total of 199 patients will be assessed for eligibility by measuring blood levels of three pro-inflammatory cytokines, and 109 patients with an inflammatory profile, i.e. inflamed, will be randomized, treated for 8 weeks and followed-up for additional four months. The primary endpoint will be changes in symptom severity as assessed by total Positive and Negative Syndrome Scale (PANSS) score changes from baseline to week 8. Secondary endpoints include various other measures of psychopathology and safety. Additional health economic analyses will be performed. TargetFlame is the first study aimed at evaluating the efficacy, safety and cost-effectiveness of the antiphlogistic agent Celecoxib in a subset of patients with schizophrenia spectrum disorders exhibiting an inflammatory profile. With TargetFlame, we intended to investigate a novel precision medicine approach towards anti-inflammatory antipsychotic treatment augmentation using drug repurposing. Clinical trial registration: http://www.drks.de/DRKS00029044 and https://trialsearch.who.int/Trial2.aspx?TrialID=DRKS00029044.
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Antipsicóticos , Esquizofrenia , Humanos , Celecoxib/uso terapéutico , Antipsicóticos/efectos adversos , Esquizofrenia/tratamiento farmacológico , Método Doble Ciego , Resultado del Tratamiento , CitocinasRESUMEN
BACKGROUND: Quick symptomatic remission after the onset of psychotic symptoms is critical in schizophrenia treatment, determining the subsequent disease course and recovery. In this context, only every second patient with acute schizophrenia achieves symptomatic remission within three months of initiating antipsychotic treatment. The potential indication extension of clozapine-the most effective antipsychotic-to be introduced at an earlier stage (before treatment-resistance) is supported by several lines of evidence, but respective clinical trials are lacking. METHODS: Two hundred-twenty patients with acute non-treatment-resistant schizophrenia will be randomized in this double-blind, 8-week parallel-group multicentric trial to either clozapine or olanzapine. The primary endpoint is the number of patients in symptomatic remission at the end of week 8 according to international consensus criteria ('Andreasen criteria'). Secondary endpoints and other assessments comprise a comprehensive safety assessment (i. e., myocarditis screening), changes in psychopathology, global functioning, cognition, affective symptoms and quality of life, and patients' and relatives' views on treatment. DISCUSSION: This multicentre trial aims to examine whether clozapine is more effective than a highly effective second-generation antipsychotics (SGAs), olanzapine, in acute schizophrenia patients who do not meet the criteria for treatment-naïve or treatment-resistant schizophrenia. Increasing the likelihood to achieve symptomatic remission in acute schizophrenia can improve the overall outcome, reduce disease-associated burden and potentially prevent mid- and long-term disease chronicity.
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Antipsicóticos , Clozapina , Esquizofrenia , Humanos , Antipsicóticos/uso terapéutico , Clozapina/uso terapéutico , Estudios Multicéntricos como Asunto , Olanzapina/uso terapéutico , Calidad de Vida , Ensayos Clínicos Controlados Aleatorios como Asunto , Esquizofrenia/tratamiento farmacológico , Resultado del TratamientoRESUMEN
BACKGROUND: Antipsychotic drugs are the mainstay treatment for schizophrenia, yet they are associated with diverse and potentially dose-related side effects which can reduce quality of life. For this reason, the lowest possible doses of antipsychotics are generally recommended, but higher doses are often used in clinical practice. It is still unclear if and how antipsychotic doses could be reduced safely in order to minimise the adverse-effect burden without increasing the risk of relapse. OBJECTIVES: To assess the efficacy and safety of reducing antipsychotic dose compared to continuing the current dose for people with schizophrenia. SEARCH METHODS: We conducted a systematic search on 10 February 2021 at the Cochrane Schizophrenia Group's Study-Based Register of Trials, which is based on CENTRAL, MEDLINE, Embase, CINAHL, PsycINFO, PubMed, ClinicalTrials.gov, ISRCTN, and WHO ICTRP. We also inspected the reference lists of included studies and previous reviews. SELECTION CRITERIA: We included randomised controlled trials (RCTs) comparing any dose reduction against continuation in people with schizophrenia or related disorders who were stabilised on their current antipsychotic treatment. DATA COLLECTION AND ANALYSIS: At least two review authors independently screened relevant records for inclusion, extracted data from eligible studies, and assessed the risk of bias using RoB 2. We contacted study authors for missing data and additional information. Our primary outcomes were clinically important change in quality of life, rehospitalisations and dropouts due to adverse effects; key secondary outcomes were clinically important change in functioning, relapse, dropouts for any reason, and at least one adverse effect. We also examined scales measuring symptoms, quality of life, and functioning as well as a comprehensive list of specific adverse effects. We pooled outcomes at the endpoint preferably closest to one year. We evaluated the certainty of the evidence using the GRADE approach. MAIN RESULTS: We included 25 RCTs, of which 22 studies provided data with 2635 participants (average age 38.4 years old). The median study sample size was 60 participants (ranging from 18 to 466 participants) and length was 37 weeks (ranging from 12 weeks to 2 years). There were variations in the dose reduction strategies in terms of speed of reduction (i.e. gradual in about half of the studies (within 2 to 16 weeks) and abrupt in the other half), and in terms of degree of reduction (i.e. median planned reduction of 66% of the dose up to complete withdrawal in three studies). We assessed risk of bias across outcomes predominantly as some concerns or high risk. No study reported data on the number of participants with a clinically important change in quality of life or functioning, and only eight studies reported continuous data on scales measuring quality of life or functioning. There was no difference between dose reduction and continuation on scales measuring quality of life (standardised mean difference (SMD) -0.01, 95% confidence interval (CI) -0.17 to 0.15, 6 RCTs, n = 719, I2 = 0%, moderate certainty evidence) and scales measuring functioning (SMD 0.03, 95% CI -0.10 to 0.17, 6 RCTs, n = 966, I2 = 0%, high certainty evidence). Dose reduction in comparison to continuation may increase the risk of rehospitalisation based on data from eight studies with estimable effect sizes; however, the 95% CI does not exclude the possibility of no difference (risk ratio (RR) 1.53, 95% CI 0.84 to 2.81, 8 RCTs, n = 1413, I2 = 59% (moderate heterogeneity), very low certainty evidence). Similarly, dose reduction increased the risk of relapse based on data from 20 studies (RR 2.16, 95% CI 1.52 to 3.06, 20 RCTs, n = 2481, I2 = 70% (substantial heterogeneity), low certainty evidence). More participants in the dose reduction group in comparison to the continuation group left the study early due to adverse effects (RR 2.20, 95% CI 1.39 to 3.49, 6 RCTs with estimable effect sizes, n = 1079, I2 = 0%, moderate certainty evidence) and for any reason (RR 1.38, 95% CI 1.05 to 1.81, 12 RCTs, n = 1551, I2 = 48% (moderate heterogeneity), moderate certainty evidence). Lastly, there was no difference between the dose reduction and continuation groups in the number of participants with at least one adverse effect based on data from four studies with estimable effect sizes (RR 1.03, 95% CI 0.94 to 1.12, 5 RCTs, n = 998 (4 RCTs, n = 980 with estimable effect sizes), I2 = 0%, moderate certainty evidence). AUTHORS' CONCLUSIONS: This review synthesised the latest evidence on the reduction of antipsychotic doses for stable individuals with schizophrenia. There was no difference between dose reduction and continuation groups in quality of life, functioning, and number of participants with at least one adverse effect. However, there was a higher risk for relapse and dropouts, and potentially for rehospitalisations, with dose reduction. Of note, the majority of the trials focused on relapse prevention rather potential beneficial outcomes on quality of life, functioning, and adverse effects, and in some studies there was rapid and substantial reduction of doses. Further well-designed RCTs are therefore needed to provide more definitive answers.
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Antipsicóticos , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Esquizofrenia , Humanos , Adulto , Antipsicóticos/efectos adversos , Reducción Gradual de Medicamentos , Esquizofrenia/tratamiento farmacológico , Calidad de Vida , RecurrenciaRESUMEN
BACKGROUND: In clinical practice, different antipsychotics can be combined in the treatment of people with schizophrenia (polypharmacy). This strategy can aim at increasing efficacy, but might also increase the adverse effects due to drug-drug interactions. Reducing polypharmacy by withdrawing one or more antipsychotics may reduce this problem, but must be done carefully, in order to maintain efficacy. OBJECTIVES: To examine the effects and safety of reducing antipsychotic polypharmacy compared to maintaining people with schizophrenia on the same number of antipsychotics. SEARCH METHODS: On 10 February 2021, we searched the Cochrane Schizophrenia Group's Study-Based Register of Trials, which is based on CENTRAL, CINAHL, ClinicalTrials.Gov, Embase, ISRCTN, MEDLINE, PsycINFO, PubMed and WHO ICTRP. SELECTION CRITERIA: We included randomised controlled trials (RCTs) that compared reduction in the number of antipsychotics to continuation of the current number of antipsychotics. We included adults with schizophrenia or related disorders who were receiving more than one antipsychotic and were stabilised on their current treatment. DATA COLLECTION AND ANALYSIS: Two review authors independently screened all the identified references for inclusion, and all the full papers. We contacted study authors if we needed any further information. Two review authors independently extracted the data, assessed the risk of bias using RoB 2 and the certainty of the evidence using the GRADE approach. The primary outcomes were: quality of life assessed as number of participants with clinically important change in quality of life; service use assessed as number of participants readmitted to hospital and adverse effects assessed with number of participants leaving the study early due to adverse effects. MAIN RESULTS: We included five RCTs with 319 participants. Study duration ranged from three months to one year. All studies compared polypharmacy continuation with two antipsychotics to polypharmacy reduction to one antipsychotic. We assessed the risk of bias of results as being of some concern or at high risk of bias. A lower number of participants left the study early due to any reason in the polypharmacy continuation group (risk ratio (RR) 0.44, 95% confidence interval (CI) 0.29 to 0.68; I2 = 0%; 5 RCTs, n = 319; low-certainty evidence), and a lower number of participants left the study early due to inefficacy (RR 0.21, 95% CI 0.07 to 0.65; I2 = 0%; 3 RCTs, n = 201). Polypharmacy continuation resulted in more severe negative symptoms (MD 3.30, 95% CI 1.51 to 5.09; 1 RCT, n = 35). There was no clear difference between polypharmacy reduction and polypharmacy continuation on readmission to hospital, leaving the study early due to adverse effects, functioning, global state, general mental state and positive symptoms, number of participants with at least one adverse effect, weight gain and other specific adverse effects, mortality and cognition. We assessed the certainty of the evidence as very low or low across measured outcomes. No studies reported quality of life, days in hospital, relapse, depressive symptoms, behaviour and satisfaction with care. Due to lack of data, it was not possible to perform some planned sensitivity analyses, including one controlling for increasing the dose of the remaining antipsychotic. As a result, we do not know if the observed results might be influenced by adjustment of dose of remaining antipsychotic compound. AUTHORS' CONCLUSIONS: This review summarises the latest evidence on polypharmacy continuation compared with polypharmacy reduction. Our results show that polypharmacy continuation might be associated with a lower number of participants leaving the study early, especially due to inefficacy. However, the evidence is of low and very low certainty and the data analyses based on few study only, so that it is not possible to draw strong conclusions based on the results of the present review. Further high-quality RCTs are needed to investigate this important topic.
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Antipsicóticos , Esquizofrenia , Adulto , Antipsicóticos/efectos adversos , Humanos , Polifarmacia , Esquizofrenia/tratamiento farmacológico , Aumento de PesoRESUMEN
Online peer-to-peer (P2P) sales of used and or high-value goods are gaining more and more relevance today. However, since potential buyers cannot physically examine the product quality during online sales, information asymmetries and consequently uncertainty and mistrust that already exist in offline sales are exacerbated in online markets. Authenticated data platforms have been proposed to solve these problems by providing authenticated data about the negotiation object, integrating it into text-based channels secured by IT. Yet, we know little about the dynamics of online negotiations today and the impact of the introduction of authenticated data on online negotiation behaviors. We address this research gap based on two experimental studies along with the example of online used car trade. We analyze users' communicative and strategic actions in current P2P chat-based negotiations and examine how the introduction of authenticated data affects these behaviors using a conceptional model derived from literature. Our results show that authenticated data can promote less complex negotiation processes and more honest communication behavior between buyers and sellers. Further, the results indicate that chats with the availability of authenticated data can positively impact markets with information asymmetries. These insights provide valuable contributions for academics interested in the dynamics of online negotiations and the effects of authenticated data in text-based online negotiations. In addition, providers of trade platforms who aim to advance their P2P sales platforms benefit by achieving a competitive advantage and a higher number of customers.
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Colorectal cancer (CRC) is rare in young patients without a confirmed family history of cancer. Reports of an increased prevalence of POLD1/POLE mutations in young patients with colorectal cancer have raised awareness and support routine genetic testing for patients with early-onset tumors. In cases of CRC without proven MMR-germline mutation, molecular analyses are warranted to confirm or rule out other familial CRC syndromes. This article describes the cases of two young male patients, who presented with locally advanced and metastatic CRC, and reports the results of the germline mutational analyses done for both patients. These cases demonstrate the importance of special care and molecular diagnostic procedures for young patients with CRC. KEY POINTS: Patients with colorectal cancer who are younger than 50 years at initial diagnosis (early onset) should routinely undergo genetic testing.Early- and very-early-onset patients (younger than 40 years) with absence of microsatellite instability should be considered for tumor mutation burden testing and/or DNA polymerase proofreading mutation.The mutational signature of HSP110 within mismatch repair deficiency-related tumors may help to identify patients likely to benefit from 5-fluorouracil-based chemotherapy.Intensified, maintained, and specific surveillance may help to reduce secondary tumor progression.
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Biomarcadores de Tumor/genética , Neoplasias Colorrectales/diagnóstico , Pruebas Genéticas/métodos , Mutación de Línea Germinal , Inestabilidad de Microsatélites , Síndromes Neoplásicos Hereditarios/diagnóstico , Adulto , Neoplasias Colorrectales/genética , Reparación de la Incompatibilidad de ADN , ADN Polimerasa III/genética , Diagnóstico Diferencial , Proteínas del Choque Térmico HSP110/genética , Humanos , Masculino , Síndromes Neoplásicos Hereditarios/genética , PronósticoRESUMEN
Mismatch-repair deficient (MMR-D) malignancies include Lynch Syndrome (LS), which is secondary to germline mutations in one of the MMR genes, and the rare childhood-form of constitutional mismatch repair-deficiency (CMMR-D); caused by bi-allelic MMR gene mutations. A hallmark of LS-associated cancers is microsatellite instability (MSI), characterized by coding frameshift mutations (cFSM) in target genes. By contrast, tumors arising in CMMR-D patients are thought to display a somatic mutation pattern differing from LS. This study has the main goal to identify cFSM in MSI target genes relevant in CMMR-D and to compare the spectrum of common somatic mutations, including alterations in DNA polymerases POLE and D1 between LS and CMMR-D. CMMR-D-associated tumors harbored more somatic mutations compared to LS cases, especially in the TP53 gene and in POLE and POLD1, where novel mutations were additionally identified. Strikingly, MSI in classical mononucleotide markers BAT40 and CAT25 was frequent in CMMR-D cases. MSI-target gene analysis revealed mutations in CMMR-D-associated tumors, some of them known to be frequently hit in LS, such as RNaseT2, HT001, and TGFßR2. Our results imply a general role for these cFSM as potential new drivers of MMR-D tumorigenesis.
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Biomarcadores de Tumor/genética , Neoplasias Colorrectales Hereditarias sin Poliposis/genética , Reparación de la Incompatibilidad de ADN/genética , Enzimas Reparadoras del ADN/genética , Mutación del Sistema de Lectura/genética , Inestabilidad de Microsatélites , Adulto , Niño , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , PronósticoRESUMEN
BACKGROUND: Preclinical studies recently showed that the mineralocorticoid antagonist spironolactone acts also as an antagonist of the NRG1-ERBB4 signaling pathway and improves schizophrenia-like behaviour in Nrg1 transgenic mouse model. As this signaling pathway is critically linked to the pathophysiology of schizophrenia, especially in the context of working-memory dysfunction, spironolactone may be a novel treatment option for patients with schizophrenia targeting cognitive impairments. AIMS: To evaluate whether spironolactone added to an ongoing antipsychotic treatment improves cognitive functioning in schizophrenia. METHODS: The add-on spironolactone for the treatment of schizophrenia trial (SPIRO-TREAT) is a multicenter randomized, placebo-controlled trial with three arms (spironolactone 100 mg, spironolactone 200 mg and placebo). Schizophrenia patients are treated for three weeks and then followed-up for additional nine weeks. As primary outcome, we investigate changes in working memory before and at the end of the intervention phase. We will randomize 90 patients. Eighty-one patients are intended to reach the primary endpoint measure at the end of the three-week intervention period. Secondary endpoints include other measures of cognition, psychopathology, safety measures and biological measures. CONCLUSIONS: SPIRO-TREAT is the first study evaluating the efficacy of the mineralocorticoid receptor antagonist spironolactone to improve cognitive impairments in schizophrenia patients targeting the NRG1-ERBB4 signaling pathway. With SPIRO-TREAT, we intend to investigate a novel treatment option for cognitive impairments in schizophrenia that goes beyond the established concepts of interfering with dopaminergic neurotransmission as key pathway in schizophrenia treatment. CLINICAL TRIAL REGISTRATION: International Clinical Trials Registry Platform: http://apps.who.int/trialsearch/Trial2.aspx?TrialID=EUCTR2014-001968-35-DE.
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BACKGROUND: Recently, an association between Zika virus infection and microcephaly/ocular findings was found to be reasonable e.g. because of the demonstration that the virus was found in the brain of a fetus after presumed maternal infection. Although there is no proof yet for a causal relationship, for an appropriate risk calculation efforts are urgently needed to either establish or disprove this assumption. PRESENTATION OF THE HYPOTHESIS: On the basis of inherited syndromes combining microcephaly with ocular findings similar to those associated with Zika infections, we have hypothesized that the impairment of the proper function of the mitotic apparatus is a possible mechanism by which Zika can exert teratogenic effects. TESTING THE HYPOTHESIS: A bundle of well-known cytogenetic and molecular-cytogenetic methods (e.g. formation of micronuclei, chromosomal lagging, immunofluorescence of centrosomes) to evaluate proper function, maintenance, and establishment of the mitotic spindle poles can be applied on infected cells. Also, the viral proteins can be tested for their possible interaction with proteins encoded by genes involved in inherited syndromes with microcephaly and ocular findings resembling those in presumed cases of intrauterine ZIKV infection. IMPLICATIONS OF THE HYPOTHESIS: Once proved, this hypothesis allows for a targeted approach into mechanisms of possible relevance as e.g. if different strains of the virus are implicated in the teratogenic effects to the same or a different extent.
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BACKGROUND: Dystonia is a clinically and genetically heterogeneous movement disorder characterized by sustained muscle contractions affecting one or more sites of the body, frequently causing twisting and repetitive movements or abnormal postures. A 3-base pair (GAG) deletion in the DYT1 gene is held responsible for most cases of early-onset primary generalized dystonia in the Ashkenazi Jewish population as well as in non-Jewish patients. OBJECTIVES: To investigate the prevalence of the GAG deletion in the DYT1 gene and the phenotypic variability in the general population by testing patients with different subtypes of dystonia from 4 different movement disorder outpatient clinics in Germany. METHODS: Two hundred fifty-six patients were tested for the GAG deletion mutation in the DYT1 gene by means of published primers and polymerase chain reaction amplification to determine GAG deletion status. RESULTS: Six of the 256 patients did carry the GAG-deletion in the DYT1 gene. However, only 2 of the 6 mutation carriers presented with what is thought to represent classic features of early-onset primary generalized dystonia. The DYT1 mutation was also detected in 2 patients with multifocal dystonia, 1 of them presenting with involvement of cranial and cervical muscles, and in 2 patients with writer's cramp of both hands with only slight progression. Our findings demonstrate that the mutation may be associated with not only generalized but also segmental and multifocal forms of dystonia. CONCLUSIONS: Our data underline the wide range of phenotypic variability of the DYT1 mutation. A priori prediction of the mutation carrier status in dystonic patients and genetic counseling of affected families with respect to the clinical manifestation may prove difficult.
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Emparejamiento Base/genética , Proteínas Portadoras/genética , Distonía/epidemiología , Distonía/genética , Eliminación de Gen , Variación Genética , Chaperonas Moleculares , Análisis Mutacional de ADN , Cartilla de ADN/genética , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Fenotipo , Mutación Puntual/genética , Postura , PrevalenciaRESUMEN
Multiple sclerosis is not known to be a risk factor for subsequent development of cancer. Recently, a multiple sclerosis locus was mapped adjacent to BRCA1 gene. We present a familial case affected by multiple sclerosis and cancer. We identified a c.5266dupC (5382insC) frameshift mutation in a 33-year-old woman with breast cancer, multiple malignant melanomas and multiple sclerosis. The patient's family history shows further cases of multiple sclerosis in BRCA1 mutation carriers. Therefore the presented family may carry a monogenic predisposition for multiple sclerosis nearby to BRCA1.
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Proteína BRCA1/genética , Neoplasias de la Mama/genética , Carcinoma Ductal de Mama/genética , Melanoma/genética , Esclerosis Múltiple/genética , Neoplasias Primarias Secundarias/genética , Adulto , Secuencia de Bases , Neoplasias de la Mama/terapia , Carcinoma Ductal de Mama/terapia , Análisis Mutacional de ADN , Femenino , Mutación del Sistema de Lectura , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Humanos , Melanoma/terapia , Mutagénesis Insercional , Neoplasias Primarias Secundarias/terapia , Linaje , Factores de RiesgoAsunto(s)
Trabajo de Parto/psicología , Partería , Relaciones Metafisicas Mente-Cuerpo , Madres/psicología , Parto Normal/psicología , Dolor/psicología , Femenino , Humanos , Partería/métodos , Relaciones Madre-Hijo , Parto Normal/métodos , Rol de la Enfermera , Relaciones Enfermero-Paciente , EmbarazoRESUMEN
Autosomal dominant spinocerebellar ataxias (SCAs) are a group of neurodegenerative disorders clinically characterized by late-onset ataxia and variable other manifestations. Genetically and clinically, SCA is highly heterogeneous. Recently, CAG repeat expansions in the gene encoding TATA-binding protein (TBP) have been found in a new form of SCA, which has been designated SCA17. To estimate the frequency of SCA17 among white SCA patients and to define the phenotypic variability, we determined the frequency of SCA17 in a large sample of 1,318 SCA patients. In total, 15 patients in four autosomal dominant SCA families had CAG/CAA repeat expansions in the TBP gene ranging from 45 to 54 repeats. The clinical features of our SCA17 patients differ from other SCA types by manifesting with psychiatric abnormalities and dementia. The neuropathology of SCA17 can be classified as a "pure cerebellar" or "cerebello-olivary" form of ataxia. However, intranuclear neuronal inclusion bodies with immunoreactivity to anti-TBP and antipolyglutamine were much more widely distributed throughout the brain gray matter than in other SCAs. Based on clinical and genetic data, we conclude that SCA17 is rare among white SCA patients. SCA17 should be considered in sporadic and familial cases of ataxia with accompanying psychiatric symptoms and dementia.
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Encéfalo/patología , Neuronas/ultraestructura , Ataxias Espinocerebelosas/patología , Adolescente , Adulto , Niño , Femenino , Humanos , Inmunohistoquímica , Cuerpos de Inclusión/ultraestructura , Imagen por Resonancia Magnética , Masculino , Neuronas/patología , Linaje , Reacción en Cadena de la Polimerasa , Proteína de Unión a TATA-Box/genética , Repeticiones de Trinucleótidos/genéticaRESUMEN
To evaluate the significance of expanded CTG repeats at the SCA8 locus, we analyzed the allele distribution in 1,262 German ataxia patients. We found intermediate and expanded CTG repeats with similar frequencies in ataxia patients with and without established genetic diseases. One family linked to the SCA8 locus showed incomplete penetrance and an association of smaller CTG repeats with more severe disease. Our data question the disease-causing character of CTG expansions for SCA8 and advise great caution in genetic testing.
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Ataxia/genética , Proteínas del Tejido Nervioso/genética , Mutación Puntual/genética , Expansión de Repetición de Trinucleótido/genética , Adulto , Edad de Inicio , Anciano , Alelos , Ataxia/epidemiología , Análisis Mutacional de ADN , Humanos , Persona de Mediana Edad , Linaje , Regiones Promotoras Genéticas/genética , ARN Largo no Codificante , ARN no Traducido , Índice de Severidad de la EnfermedadAsunto(s)
Fibrosis Quística/diagnóstico , Pruebas Genéticas , Genotipo , Preescolar , Fibrosis Quística/genética , Femenino , HumanosRESUMEN
Huntington's disease (HD) is a late manifesting neurodegenerative disorder in humans caused by an expansion of a CAG trinucleotide repeat of more than 39 units in a gene of unknown function. Several mouse models have been reported which show rapid progression of a phenotype leading to death within 3-5 months (transgenic models) resembling the rare juvenile course of HD (Westphal variant) or which do not present with any symptoms (knock-in mice). Owing to the small size of the brain, mice are not suitable for repetitive in vivo imaging studies. Also, rapid progression of the disease in the transgenic models limits their usefulness for neurotransplantation. We therefore generated a rat model transgenic of HD, which carries a truncated huntingtin cDNA fragment with 51 CAG repeats under control of the native rat huntingtin promoter. This is the first transgenic rat model of a neurodegenerative disorder of the brain. These rats exhibit adult-onset neurological phenotypes with reduced anxiety, cognitive impairments, and slowly progressive motor dysfunction as well as typical histopathological alterations in the form of neuronal nuclear inclusions in the brain. As in HD patients, in vivo imaging demonstrates striatal shrinkage in magnetic resonance images and a reduced brain glucose metabolism in high-resolution fluor-deoxy-glucose positron emission tomography studies. This model allows longitudinal in vivo imaging studies and is therefore ideally suited for the evaluation of novel therapeutic approaches such as neurotransplantation.