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1.
Radiat Oncol ; 10: 266, 2015 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-26715553

RESUMO

BACKGROUND: Total body irradiation (TBI) has been part of standard conditioning regimens before allogeneic stem cell transplantation for many years. Its effect on normal tissue in these patients has not been studied extensively. METHOD: We studied the in vivo cytogenetic effects of TBI and high-dose chemotherapy on skin fibroblasts from 35 allogeneic stem cell transplantation (SCT) patients. Biopsies were obtained prospectively (n = 18 patients) before, 3 and 12 months after allogeneic SCT and retrospectively (n = 17 patients) 23-65 months after SCT for G-banded chromosome analysis. RESULTS: Chromosomal aberrations were detected in 2/18 patients (11 %) before allogeneic SCT, in 12/13 patients (92 %) after 3 months, in all patients after 12 months and in all patients in the retrospective group after allogeneic SCT. The percentage of aberrant cells was significantly higher at all times after allogeneic SCT compared to baseline analysis. Reciprocal translocations were the most common aberrations, but all other types of stable, structural chromosomal aberrations were also observed. Clonal aberrations were observed, but only in three cases they were detected in independently cultured flasks. A tendency to non-random clustering throughout the genome was observed. The percentage of aberrant cells was not different between patients with and without secondary malignancies in this study group. CONCLUSION: High-dose chemotherapy and TBI leads to severe chromosomal damage in skin fibroblasts of patients after SCT. Our long-term data suggest that this damage increases with time, possibly due to in vivo radiation-induced chromosomal instability.


Assuntos
Aberrações Cromossômicas/efeitos da radiação , Fibroblastos/efeitos da radiação , Transplante de Células-Tronco Hematopoéticas/métodos , Condicionamento Pré-Transplante/efeitos adversos , Irradiação Corporal Total/efeitos adversos , Adolescente , Adulto , Aloenxertos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Pele/efeitos da radiação , Condicionamento Pré-Transplante/métodos , Adulto Jovem
2.
J Laryngol Otol ; 127(4): 349-53, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23433057

RESUMO

BACKGROUND: The main aim of tympanic membrane repair is the elimination of chronic or intermittent aural discharge. Hearing improvement may or may not occur following a technically successful operation. METHOD: This study entailed a retrospective analysis of prospectively collected data from 203 operations that resulted in an intact tympanic membrane 6 months after surgery. RESULTS: Complete hearing data were available for 169 operations on 160 patients. Of these, 53 per cent resulted in closure of the air-bone gap to within 10 dB, and 54 per cent of cases had post-operative hearing thresholds of at least 30 dB. The mean hearing change after surgery was +8.3 dB. Multiple regression analysis indicated that hearing improvement was more likely in large compared with small perforations. Smaller hearing gains occurred in ears with erosion of the stapes arch and/or fixation of the stapes, as well as in those with active discharge at the time of surgery and in revision cases. CONCLUSION: Greater hearing improvement can be expected following successful repair of perforations involving more than 50 per cent of the drum area. Poorer results are likely to occur in ears with additional middle-ear pathology and in revision cases.


Assuntos
Perda Auditiva/cirurgia , Miringoplastia , Perfuração da Membrana Timpânica/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Perda Auditiva/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Perfuração da Membrana Timpânica/fisiopatologia , Adulto Jovem
3.
Neuroscience ; 206: 25-38, 2012 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-22260869

RESUMO

Arsenite treatment of human SH-SY5Y neuroblastoma cells leads to an upregulation of caspase-3/7 activity and to the fragmentation of chromatin that is accompanied by elevated p53 and c-Jun levels. Expression of a truncated mutant of p53, p53DD, which interfered with the oligomerization of p53, suppressed the arsenite-induced upregulation of caspase-3/7 activity and the fragmentation of chromatin, indicating that p53 is required for arsenite-induced cell death. These data were corroborated by knockdown experiments of p53 following expression of a p53-specific short hairpin RNA. Likewise, expression of either p53DD or knockdown of p53 prevented caspase-3/7 activation and chromatin fragmentation induced by nutlin-3, a compound that prevents the interaction between p53 and the E3 ubiquitin ligase MDM2. Transcriptional upregulation of a chromatin-embedded p53-responsive reporter gene in either arsenite or nutlin-3 stimulated neuroblastoma cells revealed that the transcriptional activity of p53 was increased under these conditions. Expression of a c-Jun-specific short hairpin RNA failed to impair arsenite-induced caspase-3/7 activation and fragmentation of chromatin. Likewise, inhibition of c-Jun target gene expression by expression of a dominant-negative mutant of c-Jun did not interfere with arsenite-induced caspase-3/7 activation and chromatin fragmentation. However, this approach successfully reduced caspase-3/7 activity induced as a result of forced expression of a constitutively active mutant of mitogen-activated protein kinase/extracellular signal-regulated kinase kinase kinase (MEKK)-1. Together, these data show that the upregulation of p53 is causally linked with arsenite-induced cell death in neuroblastoma cells, whereas the upregulation of c-Jun is not part of this apoptotic signaling cascade.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Arsenitos/farmacologia , Neuroblastoma/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Western Blotting , Linhagem Celular Tumoral , Humanos , Marcação In Situ das Extremidades Cortadas , Proteínas Proto-Oncogênicas c-jun/metabolismo , Transdução de Sinais/fisiologia
4.
J Laryngol Otol ; 126(2): 207-9, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21914245

RESUMO

BACKGROUND: Wegener's granulomatosis is a rare but well recognised autoimmune necrotising vasculitis. Presentation of disease in the head and neck is common and mostly consists of nasal crusting, blockage and bloody discharge. Neurological presentation is very uncommon. METHODS: We report a patient who presented to the medical emergency services with signs and symptoms of meningitis, but who was eventually diagnosed with Wegener's granulomatosis. A literature search on this topic was carried out using Medline and Embase (1996 to 2011), searching for 'Wegener's granulomatosis' and 'meningitis'. RESULTS: After thorough neurological and medical investigation, a combination of brain computed tomography, lumbar puncture, nasal biopsy and laboratory results refuted the diagnosis of meningitis and confirmed the diagnosis of Wegener's granulomatosis. CONCLUSION: To the best of our knowledge, this is the first English-language case report of a patient with Wegener's granulomatosis presenting with symptoms of meningitis unconfirmed on computed tomography and lumbar puncture.


Assuntos
Granulomatose com Poliangiite/diagnóstico , Meningite/diagnóstico , Doenças Nasais/diagnóstico , Doença Aguda , Anti-Inflamatórios/uso terapêutico , Anticorpos Anticitoplasma de Neutrófilos/análise , Biópsia , Ciclofosfamida/uso terapêutico , Diagnóstico Diferencial , Quimioterapia Combinada , Feminino , Granulomatose com Poliangiite/tratamento farmacológico , Granulomatose com Poliangiite/patologia , Cefaleia/diagnóstico , Humanos , Imunossupressores/uso terapêutico , Pessoa de Meia-Idade , Doenças Nasais/tratamento farmacológico , Doenças Nasais/patologia , Prednisolona/uso terapêutico , Punção Espinal , Tomografia Computadorizada por Raios X
6.
J Laryngol Otol ; 125(5): 460-6, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21144098

RESUMO

BACKGROUND: Stapedotomy produces the best hearing results of any otological operation. However, in a small number of cases the air-bone gap is not successfully closed, or conductive hearing loss recurs. OBJECTIVE: To investigate the proportion of cases in the senior author's series which required revision surgery and to determine the medium to long term success rate of surgery, taking into account the results of revision surgery. METHODS: Review of a series of 233 primary stapedotomy operations and 100 revision procedures carried out by one surgeon over a 20-year period. RESULTS: Closure of the air-bone gap to within 10 dB was achieved in 80 per cent of cases following the primary procedure. Fifteen per cent of patients developed a recurrence of conductive hearing loss. When the results of revision surgery were taken into account, the proportion of ears with a mean air-bone gap of less than 10 dB was 86 per cent. However, of the patients undergoing revision surgery, air-bone gap closure to within 10 dB was only achieved in 52 per cent of cases. CONCLUSION: The best chance of obtaining a successful outcome in stapedotomy is to achieve this for the first procedure. However, revision surgery does increase the medium to long term success rate.


Assuntos
Condução Óssea/fisiologia , Perda Auditiva Condutiva/cirurgia , Otosclerose/cirurgia , Cirurgia do Estribo/efeitos adversos , Adulto , Surdez/etiologia , Surdez/cirurgia , Feminino , Audição/fisiologia , Perda Auditiva Condutiva/etiologia , Humanos , Bigorna/patologia , Bigorna/cirurgia , Terapia a Laser/métodos , Masculino , Pessoa de Meia-Idade , Prótese Ossicular , Falha de Prótese/efeitos adversos , Recidiva , Reoperação/estatística & dados numéricos , Cirurgia do Estribo/métodos , Aderências Teciduais/epidemiologia , Aderências Teciduais/cirurgia , Resultado do Tratamento , Perfuração da Membrana Timpânica/epidemiologia , Perfuração da Membrana Timpânica/cirurgia
7.
Plant Biol (Stuttg) ; 11(6): 869-77, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19796364

RESUMO

PPI1 (proton pump interactor isoform 1) is a novel protein able to interact with the C-terminal autoinhibitory domain of the Arabidopsis thaliana plasma membrane (PM) H(+)-ATPase. In vitro, PPI1 binds the PM H(+)-ATPase in a site different from the known 14-3-3 binding site and stimulates its activity. In this study, we analysed the intracellular localisation of PPI1. The intracellular distribution was monitored in A. thaliana cultured cells by immunolocalisation using an antiserum against the PPI1 N-terminus and in Vicia faba guard cells and epidermal cells by transient expression of a GFP::PPI1 fusion. The results indicate that the bulk of PPI1 is localised at the endoplasmic reticulum, from which it might be recruited to the PM for interaction with the H(+)-ATPase in response to as yet unidentified signals.


Assuntos
Proteínas de Arabidopsis/análise , Arabidopsis/metabolismo , Proteínas de Transporte/análise , Membrana Celular/metabolismo , ATPases Translocadoras de Prótons/metabolismo , Arabidopsis/ultraestrutura , Proteínas de Arabidopsis/metabolismo , Sítios de Ligação , Proteínas de Transporte/metabolismo , Células Cultivadas , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/ultraestrutura , Proteínas de Fluorescência Verde/análise , Proteínas Recombinantes de Fusão/análise
8.
J Laryngol Otol ; 122(6): 580-3, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18047760

RESUMO

INTRODUCTION: There is a paucity of evidence to guide the post-operative follow up of patients undergoing middle-ear ventilation tube insertion for the first time. This study was conceived to identify current practice at our institution (Ninewells Hospital, Dundee) and to inform subsequent change in our follow-up procedure. METHODS: Two cycles of data collection and analysis were performed. All paediatric patients undergoing ventilation tube insertion for the first time were identified. Patients who had previously undergone ventilation tube insertion or additional procedures such as adenoidectomy or tonsillectomy were excluded. The first data collection period comprised all of the year 2000, and the second 18 months over 2003-2004. A minimum of 20 months' follow up was allowed for. Data regarding clinical findings and audiometry were recorded at each follow-up appointment. RESULTS: We identified a total of 50 patients meeting our criteria for inclusion in the first cohort. There were a total of 156 appointments between surgery and data collection (a mean of 3.12 per child). A total of 113 (72 per cent) appointments lead to no medical intervention. The only statistically significant difference between patients requiring further ventilation tube insertion (n = 10) and those not requiring further treatment during the study period (n = 40) was the average hearing threshold (p < 0.01). These findings prompted a change in the post-operative regime; all patients undergoing ventilation tube insertion were subsequently seen at three months for a pure tone audiogram, and further review depended on clinical and audiometric findings. Records for 84 children were identified and collected for the second cohort, there were a total of 154 appointments (a mean of 1.83 per child). In only 18 appointments (12 per cent) were normal findings and hearing recorded and children given a further review appointment. Sixteen of 29 (55 per cent) children with abnormal clinical findings (otorrhoea, tube blockage or extrusion) required some form of intervention (p < 0.05). Twenty-six had a mean hearing threshold worse than 20 dB at first review. Nineteen (73 per cent) required further intervention of some sort (p < 0.01). CONCLUSIONS: Our study demonstrated that the vast majority of review appointments resulted in no clinical intervention. We therefore question the need for regular follow up in this patient group. Twenty per cent (10 of 50 and 18 of 84) of our patients required further ventilation tube insertion within the study periods. This is consistent with rates reported in the literature. Children with abnormal clinical findings or a mean hearing threshold greater than 20 dB were significantly more likely to require further intervention. We would recommend one post-operative review with audiometry, three months after surgery. At this initial appointment, further review should be offered to those children with poor hearing, early extrusion, blockage or infection, as they are more likely to require further ventilation tube insertion. This strategy is dependent on good links with community primary care providers and easy access to secondary care for further management, should this be required.


Assuntos
Agendamento de Consultas , Ventilação da Orelha Média , Avaliação das Necessidades/estatística & dados numéricos , Otite Média com Derrame/terapia , Testes de Impedância Acústica , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Otite Média/cirurgia , Otite Média/terapia , Otite Média com Derrame/cirurgia , Satisfação do Paciente , Período Pós-Operatório , Escócia , Fatores de Tempo
9.
Leukemia ; 21(7): 1532-44, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17495977

RESUMO

The biologic and pathologic features of B-cell malignancies bearing a translocation t(14;19)(q32;q13) leading to a fusion of IGH and BCL3 are still poorly described. Herein we report the results of a comprehensive cytogenetic, fluorescence in situ hybridization (FISH), molecular and histopathological survey of a large series of B-cell malignancies with t(14;19) or variant translocations. A total of 56 B-cell malignancies with a FISH-proven BCL3 involvement were identified with the translocation partners being IGH (n=51), IGL (n=2), IGK (n=2) and a non-IG locus (n=1). Hierarchical clustering of chromosomal changes associated with the t(14;19) indicated the presence of two different groups of IG/BCL3-positive lymphatic neoplasias. The first group included 26 B-cell malignancies of various histologic subtypes containing a relatively high number of chromosomal changes and mostly mutated IgVH genes. This cluster displayed three cytogenetic branches, one with rearrangements in 7q, another with deletions in 17p and a third one with rearrangements in 1q and deletions in 6q and 13q. The second group included 19 cases, mostly diagnosed as B-cell chronic lymphocytic leukemia (B-CLL), and characterized by few additional chromosomal changes (e.g. trisomy 12) and unmutated IgVH genes. In conclusion, our study indicates that BCL3 translocations are not restricted to B-CLL but present in a heterogeneous group of B-cell malignancies.


Assuntos
Leucemia de Células B/genética , Linfoma de Células B/genética , Proteínas Proto-Oncogênicas/genética , Fatores de Transcrição/genética , Translocação Genética , Adulto , Idoso , Proteína 3 do Linfoma de Células B , Cromossomos Humanos Par 14 , Cromossomos Humanos Par 19 , Análise Citogenética , Feminino , Rearranjo Gênico , Genes de Imunoglobulinas , Histocitoquímica , Humanos , Hibridização in Situ Fluorescente , Leucemia de Células B/classificação , Leucemia de Células B/patologia , Linfoma de Células B/classificação , Linfoma de Células B/patologia , Masculino , Pessoa de Meia-Idade
10.
J Laryngol Otol ; 120(12): 1067-71, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16882362

RESUMO

We describe two patients with stapes fixation, in both of whom Rosen mobilization seemed to be the most prudent surgical choice. In both cases, a useful hearing gain was achieved initially. In the patient with otosclerosis, the conductive hearing loss recurred and a stapedectomy was subsequently carried out. In the patient with congenital stapes fixation, the hearing gain was maintained for two years eight months. We believe that this technique still has a place in stapes surgery in rare instances.


Assuntos
Perda Auditiva Condutiva/cirurgia , Mobilização do Estribo/métodos , Adolescente , Adulto , Feminino , Humanos , Resultado do Tratamento
11.
Ther Umsch ; 62(7): 449-57, 2005 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-16075950

RESUMO

The Swiss Organ Living Donor Health Registry (SOL-DHR) started in April 1993. The purpose was the prospective and sequential follow up of donors long-term health. Between 1993 and January 2005 737 Living Kidney donations were registered and followed. Two thirds of donors were female and two thirds of recipients male. The three most common relations were life-partners, parents and siblings (approximately 30% each). 10% of donors could not be followed since living far abroad and 5% were lost due to missing current address after moving. 9 donors died (4 malignancies, 2 traffic accidents, 1 myocardial infarction, 1 stroke and 1 suicide), non due to kidney donation. Perioperative complications were age dependent, ranging from 17% in donors below the age of 40 year and 46% in donors older than 70 years. The longterm complications were divided in surgical, medical and psychological ones. The most common surgical long-term complications were pain (cicatrice, back, abdomen) and hernias. The major medical complications were hypertension (35% at seven years after donation) and rising rate of Albuminuria (9% at seven years). Although hypertension was not higher than in an age matched Swiss control population, untreated hypertension was regarded as the higher risk for development of glomerulosclerosis than in people with two kidneys. No donor went into end stage renal failure. Using the SF-8-Test to quantify the psychological well-being the mean MCS (mental component summary) was 54.3 +/- 7.8 as compared to 52.9 +/- 7.7 in the age matched control population. MCS was low (< 40) in 6.2% and very low (< 25) in 2.2% of donors. 94.4 % of donors would donate again, while 4.3% would not (mostly women). The reasons not to donate again was mainly related to poor outcome of the kidney recipient, or long-lasting major pain or disappointment about medical handling before (not enough information, wrong advice) and after organ donation. The association of Swiss Living Organ Donors, where only kidney or liver donors can become a member, are organising self-help-groups for pain, psychological and financial problems (with health insurances). The organisation and financial support of SOL-DHR is briefly described. The waste majority of living kidney donors are very satisfied about the free care given by SOL-DHR.


Assuntos
Transplante de Rim/estatística & dados numéricos , Doadores Vivos/estatística & dados numéricos , Complicações Pós-Operatórias/epidemiologia , Sistema de Registros , Coleta de Tecidos e Órgãos/estatística & dados numéricos , Obtenção de Tecidos e Órgãos/estatística & dados numéricos , Humanos , Suíça/epidemiologia , Doadores de Tecidos/estatística & dados numéricos , Resultado do Tratamento
12.
Biochem Pharmacol ; 64(10): 1483-91, 2002 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-12417261

RESUMO

In the present study, we have analyzed the response of human smooth muscle cell (SMC)s to oxidative stress, in terms of recruitment of key elements of the stress-activated protein kinase (SAPK) pathway, such as Rac(1), p38, and the small heat shock protein (HSP)27. The level of expression of three small HSPs, alphaB-crystallin, HSP20, HSP27, as well as the phosphorylation levels of HSP27 and p38, were higher in cultured, asynchronously growing SMCs originating from left interior mammary artery (LIMA) than those originating from aorta, saphenous vein, and umbilical vein, validating the choice of SMCs from LIMA as a model system in our study. In synchronized, quiescent SMCs from LIMA, oxidative stress (H(2)O(2) stimulation)-induced membrane translocation of Rac(1), p38 phosphorylation, membrane translocation, and phosphorylation of HSP27. In these cells, simvastatin (S), an HMG-CoA reductase inhibitor, blocked, in a mevalonate-dependent way, oxidative stress-induced membrane translocation of Rac(1). However, S pretreatment prior to oxidative stress increased the levels of p38 phosphorylation, HSP27 membrane translocation/phosphorylation, actin polymerization, and apoptosis in these cells, in a mevalonate-dependent way. These results establish that S pretreatment has a stimulatory effect on the stress-activated p38/HSP27 pathway, despite its blocking effect on Rac(1) activation.


Assuntos
Proteínas de Choque Térmico , Músculo Liso/efeitos dos fármacos , Proteínas de Neoplasias/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Sinvastatina/farmacologia , Proteínas rac1 de Ligação ao GTP/metabolismo , Citoesqueleto de Actina/metabolismo , Anticolesterolemiantes/farmacologia , Apoptose , Células Cultivadas , Proteínas de Choque Térmico HSP27 , Humanos , Artéria Torácica Interna/citologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Chaperonas Moleculares , Músculo Liso/metabolismo , Estresse Oxidativo/fisiologia , Proteínas Quinases p38 Ativadas por Mitógeno
13.
Biochem J ; 360(Pt 3): 599-607, 2001 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-11736649

RESUMO

The activator protein 1 (AP-1) transcription factor is composed of heterodimers of the Fos/activating transcription factor (ATF) and Jun subfamilies of basic-region leucine-zipper (B-ZIP) proteins. In order to determine the identities of individual B-ZIP proteins in various AP-1 complexes we tested the effect of dominant-negative mutants to the B-ZIP proteins c-Fos, ATF2, ATF4 and CCAAT-enhancer-binding protein (C/EBP) on the activities of the collagenase and c-Jun promoters. These dominant-negative mutants inhibit DNA binding of wild-type B-ZIP proteins in a leucine-zipper-dependent fashion. Transcription of a collagenase promoter/reporter gene was induced in HepG2 hepatoma cells by expression of c-Fos and c-Jun, administration of PMA ("TPA") or by expression of a truncated form of MEK (mitogen-activated/extracellular-signal-regulated kinase kinase) kinase-1, MEKK1Delta. In all cases, the dominant-negative mutants A-Fos and A-ATF2 decreased collagenase promoter activity. However, A-ATF4 and A-C/EBP had no effect. A-Fos and A-ATF2 also reduced MEKK1Delta-induced stimulation of the c-Jun promoter. In contrast, constitutive c-Jun promoter activity was blocked solely by A-ATF2, strongly suggesting that ATF2 and/or an ATF2-dimerizing protein are of major importance for c-Jun transcription in unstimulated cells. These results demonstrate that AP-1 transcription factors of different compositions control c-jun gene transcription in resting or stimulated cells.


Assuntos
Colagenases/genética , Regulação Neoplásica da Expressão Gênica , MAP Quinase Quinase Quinase 1 , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-jun/genética , Fator de Transcrição AP-1/metabolismo , Sequência de Aminoácidos , Carcinoma Hepatocelular , Células Cultivadas , Genes Reporter , Genes jun , Humanos , Zíper de Leucina , Neoplasias Hepáticas , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Fator de Transcrição AP-1/química , Fatores de Transcrição/metabolismo
14.
Eur J Neurosci ; 14(8): 1303-12, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11703459

RESUMO

The zinc finger protein RE-1 silencing transcription factor (REST) is a transcriptional repressor that represses neuronal genes in non-neuronal tissues. We have analyzed the ability of REST and the REST mutants, RESTDeltaN and RESTDeltaC lacking either the N-terminal or C-terminal repression domains of REST, to inhibit transcription mediated by distinct transcriptional activator proteins. For this purpose we have designed an activator specific assay where transcription is activated as a result of only one distinct activation domain. In addition, binding sites for REST were inserted in the 5'-untranslated region or at a distant position downstream of the polyadenylation signal. The results show that REST or the REST mutants containing only one repression domain were able to block transcriptional activation mediated by the transcriptional activation domains derived from p53, AP2, Egr-1, and GAL4. Moreover, REST, as well as the REST mutants, blocked the activity of the phosphorylation-dependent activation domain of Elk1. However, the activity of the activation domain derived from cAMP response element binding protein 2 (CREB2), was not inhibited by REST, RESTDeltaN or RESTDeltaC, suggesting that REST is able to distinguish between distinct transcriptional activation domains. Additionally, the activator specific assay, together with a positive-dominant mutant of REST that activated instead of repressed transcription, was used in titration experiments to show that REST has transcriptional repression and no transcriptional activation properties when bound to the 5'-untranslated region of a gene.


Assuntos
Genes/genética , Mutação/genética , Proteínas Repressoras/metabolismo , Proteínas de Saccharomyces cerevisiae , Fatores de Transcrição/metabolismo , Ativação Transcricional/genética , Fator 4 Ativador da Transcrição , Bioensaio , Proteínas de Ligação a DNA/genética , Proteínas Fúngicas/genética , Genes Reporter/genética , Fosforilação , Regiões Promotoras Genéticas/genética , Biossíntese de Proteínas/genética , Estrutura Terciária de Proteína/genética , Proteínas Proto-Oncogênicas/genética , Fatores de Transcrição/genética , Proteína Supressora de Tumor p53/genética , Proteínas Elk-1 do Domínio ets
15.
Oncogene ; 20(41): 5920-9, 2001 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-11593399

RESUMO

The EB1/RP1 family is a new protein family that is characterized by the ability of its members to serve as interacting partners for the adenomatous polyposis coli (APC) tumour suppressor protein and tubulin. Data obtained with highly conserved yeast homologues suggest that the EB1/RP1 protein family promotes cytoplasmic microtubule dynamics and contributes to the sensor mechanism controlling the cytokinesis checkpoint during mitosis. However, the precise function of this protein family in mammalian cells has not been elucidated so far and remains unclear. Here, we report on the genomic localization of the RP1 gene and the characterization of the corresponding promoter. The RP1 gene was found to be encoded on chromosome 18q21, a locus which is altered or deleted in up to 50% of all patients with colorectal cancer. Promoter analysis revealed that the RP1 gene is under the control of a strong promoter that was 10 times more active in mammalian cells when compared to SV40 promoter. Members of the cyclic AMP response element binding protein family (CREB1 and CREB2) could be identified as transcription factors binding specifically within the RP1 promoter sequence.


Assuntos
Cromossomos Humanos Par 18/genética , Proteínas de Ligação a DNA/genética , Proteínas do Olho , Genes APC , Regiões Promotoras Genéticas/genética , Transativadores/genética , Transcrição Gênica , Sequência de Bases , Linhagem Celular , Mapeamento Cromossômico , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Humanos , Proteínas Associadas aos Microtúbulos , Dados de Sequência Molecular , RNA Mensageiro/metabolismo , Linfócitos T , Células Tumorais Cultivadas
16.
J Neurol Sci ; 189(1-2): 83-91, 2001 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-11535237

RESUMO

Amplification and/or mutations of the epidermal growth factor (EGF) receptor have been frequently reported in human malignant gliomas, the most common primary tumor of the adult central nervous system. We have analyzed a panel of established human glioma cell lines for EGF receptor expression. The EGF receptor was expressed in all of the glioma cell lines tested, with highest levels found in the cell line U343MG-a. In addition, various amounts of a truncated form of the EGF receptor were detected. The platelet-derived growth factor (PDGF) alpha receptor, analyzed for comparison, was expressed at low levels in human glioma cells, with the exception of U-118MG and U-373MG cells. The truncated form of the EGF receptor has been discussed as a constitutively active variant of the receptor. Using antibodies directed against the active form of the EGF receptor, we show here that the truncated variant of the EGF receptor in U343MG-a cells is not in the active conformation. However, the full-length EGF receptor, highly expressed in U343MG-a cells, was very rapidly activated following EGF treatment. In line with this, phosphorylation and activation of the mitogen-activated protein kinase/extracellular signal-regulated protein kinase (ERK) in U343MG-a cells required administration of EGF. Moreover, using highly specific riboprobes we observed that EGF signaling increased the Egr-1 mRNA concentration in human glioma cells within 30 min. The increase in the Egr-1 mRNA concentration was followed by a transient synthesis of the Egr-1 protein. Likewise, Egr-1 mRNA and protein concentrations were increased in U-118MG and U-373MG cells treated with PDGF. The synthesis of Egr-1 in human glioma cells as a result of EGF or PDGF stimulation indicates that Egr-1 may be an important "late" part of the EGF and PDGF-initiated signaling cascades suggesting that Egr-1 functions as a "third messenger" in glioma cells connecting growth factor stimulation with changes in gene transcription.


Assuntos
Neoplasias Encefálicas/patologia , Proteínas de Ligação a DNA/biossíntese , Fator de Crescimento Epidérmico/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioma/patologia , Proteínas Imediatamente Precoces , Proteínas de Neoplasias/biossíntese , Fator de Crescimento Derivado de Plaquetas/farmacologia , Fatores de Transcrição/biossíntese , Astrocitoma/patologia , Proteínas de Ligação a DNA/genética , Proteína 1 de Resposta de Crescimento Precoce , Fator de Crescimento Epidérmico/química , Glioblastoma/patologia , Humanos , Sistema de Sinalização das MAP Quinases , Proteínas de Neoplasias/genética , Fragmentos de Peptídeos/farmacologia , Conformação Proteica , Fatores de Transcrição/genética , Transcrição Gênica , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/metabolismo
17.
Brain Res Mol Brain Res ; 92(1-2): 85-97, 2001 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-11483245

RESUMO

The genetic basis of neurodegeneration in Huntington's disease (HD) has been identified as a (CAG)(>37) repeat expansion in a gene of unknown function. Interestingly, patients with the same expanded (CAG)(n) repeat length may have markedly different ages at onset. Based on experiences in animal models the level of expression might be one of the modifying factors. To gain insight into the regulation of the human HD gene we functionally analyzed 2266 bp of the HD gene promoter region. This region lacks a TATA and a CAAT box, is GCrich, and it has several consensus sequences for SP1, AP-2 and AP-4 binding sites. The stretch between nucleotides -49 and -198 relative to the first ATG is highly conserved between human and rodents and it harbors several potential binding sites for transcription factors. We analyzed deletion mutants fused with the chloramphenicol acetyltransferase (CAT) reporter gene in transfected, huntingtin expressing neuronal (NS20Y) and non-neuronal (CHO) cell lines. Partial deletion of the evolutionarily conserved part of the promoter significantly reduces the activity in both neuronal and non-neuronal cells indicating that the core promoter activity is located between nucleotides -221 and 4, relative to the +1 translation start site. Binding affinities of DNA-protein interactions were defined by electrophoretic mobility shift assays and the protected nucleotide positions were determined by DNase I footprinting.


Assuntos
Proteínas do Tecido Nervoso/genética , Proteínas Nucleares/genética , Regiões Promotoras Genéticas , Repetições de Trinucleotídeos , Idade de Início , Animais , Sequência de Bases , Sítios de Ligação , Células CHO , Cloranfenicol O-Acetiltransferase/biossíntese , Cloranfenicol O-Acetiltransferase/genética , Cricetinae , Cricetulus , Pegada de DNA , Eletroforese em Gel de Poliacrilamida , Regulação da Expressão Gênica , Genes Reporter , Humanos , Proteína Huntingtina , Doença de Huntington/epidemiologia , Doença de Huntington/genética , Óperon Lac , Camundongos , Dados de Sequência Molecular , Neuroblastoma/patologia , Neurônios/metabolismo , Penetrância , Ratos , Proteínas Recombinantes de Fusão/biossíntese , Deleção de Sequência , Especificidade da Espécie , Transfecção , Células Tumorais Cultivadas , beta-Galactosidase/biossíntese
18.
Am J Hum Genet ; 69(3): 516-27, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11468690

RESUMO

Homologous recombination between poorly characterized regions flanking the NF1 locus causes the constitutional loss of approximately 1.5 Mb from 17q11.2 covering > or =11 genes in 5%-20% of patients with neurofibromatosis type 1 (NF1). To elucidate the extent of microheterogeneity at the deletion boundaries, we used single-copy DNA fragments from the extreme ends of the deleted segment to perform FISH on metaphase chromosomes from eight patients with NF1 who had large deletions. In six patients, these probes were deleted, suggesting that breakage and fusions occurred within the adjacent highly homologous sequences. Reexamination of the deleted region revealed two novel functional genes FLJ12735 (AK022797) and KIAA0653-related (WI-12393 and AJ314647), the latter of which is located closest to the distal boundary and is partially duplicated. We defined the complete reading frames for these genes and two expressed-sequence tag (EST) clusters that were reported elsewhere and are associated with the markers SHGC-2390 and WI-9521. Hybrid cell lines carrying only the deleted chromosome 17 were generated from two patients and used to identify the fusion sequences by junction-specific PCRs. The proximal breakpoints were found between positions 125279 and 125479 in one patient and within 4 kb of position 143000 on BAC R-271K11 (AC005562) in three patients, and the distal breakpoints were found at the precise homologous position on R-640N20 (AC023278). The interstitial 17q11.2 microdeletion arises from unequal crossover between two highly homologous WI-12393-derived 60-kb duplicons separated by approximately 1.5 Mb. Since patients with the NF1 large-deletion syndrome have a significantly increased risk of neurofibroma development and mental retardation, hemizygosity for genes from the deleted region around the neurofibromin locus (CYTOR4, FLJ12735, FLJ22729, HSA272195 (centaurin-alpha2), NF1, OMGP, EVI2A, EVI2B, WI-9521, HSA272196, HCA66, KIAA0160, and WI-12393) may contribute to the severe phenotype of these patients.


Assuntos
Deleção Cromossômica , Cromossomos Humanos Par 17 , Genes da Neurofibromatose 1/genética , Neurofibromatose 1/genética , Sequência de Bases , Células Cultivadas , Mapeamento Cromossômico , DNA/análise , Evolução Molecular , Duplicação Gênica , Humanos , Hibridização in Situ Fluorescente , Cariotipagem , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Homologia de Sequência do Ácido Nucleico
19.
Transpl Infect Dis ; 3(1): 2-7, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11429033

RESUMO

Organ transplant recipients are at high risk of infectious pulmonary complications. In this retrospective study, the diagnostic yield of bronchoalveolar lavage (BAL) was evaluated in renal transplant recipients. The results were analysed in special regard to the clinical presentation of pulmonary infections and the possible impact of new immunosuppressive agents. Over a 5-year period 91 BAL were performed in 71 renal transplant recipients. Microorganisms were isolated from 69% of BAL (63/91): bacteria 32%; cytomegalovirus (CMV) 27%; Pneumocystis carinii (PC) 22%; other viruses 9% (HSV; EBV, RSV, adenovirus, HHV8); Aspergillus fumigatus 1%. Total cell counts and neutrophil counts in BAL were significantly elevated in bacterial infection, whereas BAL positive for PC showed eosinophilia (P<0.05). There was no association between clinical symptoms and the radiological pattern of infiltrates and the type of infection. Immunosuppression containing tacrolimus or mycophenolate mofetil was associated with a significantly higher percentage of PC and CMV infections compared to cyclosporin-based immunosuppression (65% vs. 30%, P<0.005). A considerable number of PC and CMV infections occurred beyond 6 months after transplantation. In conclusion, BAL has a high diagnostic yield in renal transplant recipients. Infection with CMV and PC should also be considered beyond 6 months after transplantation, and prophylaxis for opportunistic infections should be given if the immunosuppression is intensified.


Assuntos
Líquido da Lavagem Broncoalveolar/microbiologia , Transplante de Rim , Pneumonia/diagnóstico , Pneumonia/microbiologia , Adulto , Idoso , Antibacterianos/uso terapêutico , Citomegalovirus/isolamento & purificação , Infecções por Citomegalovirus/diagnóstico , Feminino , Humanos , Hospedeiro Imunocomprometido , Transplante de Rim/efeitos adversos , Masculino , Pessoa de Meia-Idade , Pneumocystis/isolamento & purificação , Infecções por Pneumocystis/diagnóstico , Pneumonia/tratamento farmacológico , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo
20.
Eur J Neurosci ; 13(7): 1339-48, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11298794

RESUMO

Corticotropin-releasing factor (CRF), a neuropeptide of 41 amino acids, acts as the major physiological regulator of the basal and stress-induced release of corticotropin (ACTH), beta-endorphin and other proopiomelanocortin-derived peptides from the anterior pituitary gland. In addition to its endocrine activity, CRF displays extrahypophysiotropic effects, mainly as a regulator of stress responses. We show here that CRF may additionally function as a differentiating factor in immortalized noradrenergic neuronal CATH.a cells that express CRF receptor type I and resemble locus coeruleus-derived neurons. CRF triggers morphological changes in CATH.a cells including the appearance of extended long, slender neurites with prominent growth cones. CRF-treated CATH.a cells exhibit a morphology similar to locus coeruleus neurons in primary culture. CRF-induced neurite outgrowth of CATH.a cells was blocked by addition of inhibitors for cAMP-dependent protein kinase or extracellular signal-regulated protein kinase (ERK), a subtype of the mitogen-activated protein kinases. The participation of ERK within the CRF signalling cascade was further confirmed by Western blot experiments, with antibodies directed against the phosphorylated form of ERK, and also with transcription-based assays. We conclude that CRF functions as a differentiating factor of CATH.a cells via the cAMP and the MAP kinase signalling pathways.


Assuntos
Hormônio Liberador da Corticotropina/farmacologia , AMP Cíclico/metabolismo , Proteínas Imediatamente Precoces , Sistema de Sinalização das MAP Quinases/fisiologia , Neuritos/efeitos dos fármacos , Neurônios/enzimologia , Norepinefrina/genética , Proteínas Proto-Oncogênicas , Proteínas de Saccharomyces cerevisiae , Animais , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Linhagem Celular Transformada , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteínas de Ligação a DNA/genética , Proteína 1 de Resposta de Crescimento Precoce , Feminino , Feto/citologia , Proteínas Fúngicas/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Locus Cerúleo/citologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Neuritos/fisiologia , Neurônios/ultraestrutura , Norepinefrina/metabolismo , Canais de Potássio/genética , Canais de Potássio/metabolismo , Gravidez , Regiões Promotoras Genéticas/fisiologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Fatores de Transcrição/genética , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/fisiologia , Proteínas Elk-1 do Domínio ets
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