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1.
Kulak Burun Bogaz Ihtis Derg ; 20(4): 195-9, 2010.
Artigo em Turco | MEDLINE | ID: mdl-20626328

RESUMO

OBJECTIVES: This study assessed the audiometric results of revision surgery in patients on whom previous canal wall up tympanoplasty had been performed for chronic otitis media without cholesteatoma, and investigated reasons for hearing improvement failure which required revision surgery. PATIENTS AND METHODS: Seventy-two patients (49 females, 23 males; mean age 35.4+/-12.9 years; range 11 to 64 years) suffering from chronic otitis media without cholesteatoma, who had intact canal wall up tympanoplasty and revision surgery due to bad hearing results between March 2004 and September 2009, were evaluated retrospectively. After evaluation of patients' files, operative and audiological records, findings during the surgery, postoperative follow-up, audiometric results before revision surgery and the results in the last control after revision surgery were analysed. RESULTS: Preoperative mean air-bone gap (ABG) decreased in all patients from 31.2 dB to 19.9 dB after followed up for mean 26.7 months. Air-bone gap values below 20 dB were 67%, below 30 dB were 83%, hearing gain above 10 dB was found to be 58%. Comparision of pre- and postoperative ABG values of the patients revealed statistically significant difference (p<0.001). In addition to hearing loss, the reasons for revision surgery were mucosal disease relapse in 10 patients, graft perforation in 43 patients, otorrhea control in 15 patients. Findings during revision surgery were relapse of mucosal diseases in 15 patients, insufficient mastoidectomy in six patients, problems related to prosthesis in 29 patients, ossicular limitations (brid, hyalen and granulation) in 30 patients, and ossicular necrosis in six patients. The decision for four patients was changed from canal wall up tympanoplasty to canal wall down tympanoplasty. Postoperative total hearing loss developed in one case. CONCLUSION: The most important problem in revision of tympanoplasty patients with hearing loss is related with stabilisation of columella. To get successful hearing results, it is important to control disease and provide a stable and safe continuity between the tympanic membrane and vestibule.


Assuntos
Otite Média/cirurgia , Reoperação/métodos , Reoperação/estatística & dados numéricos , Timpanoplastia/métodos , Adolescente , Adulto , Audiometria de Tons Puros , Criança , Colesteatoma , Doença Crônica , Feminino , Humanos , Masculino , Processo Mastoide/cirurgia , Pessoa de Meia-Idade , Substituição Ossicular/métodos , Membrana Timpânica/cirurgia , Timpanoplastia/efeitos adversos
2.
J Radiol Prot ; 29(3): 409-15, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19690355

RESUMO

Renal stones can be treated either by extracorporeal shock wave lithotripsy (ESWL) or percutaneous nephrolithotomy (PCNL). Increasing use of fluoroscopic exposure for access and to detect stone location during PCNL make the measurement of patient and staff doses important. The main objective of this work was to assess patient and urologist doses for the PCNL examination. We used the tube output technique for determination of patient doses (n = 20) and lithium fluoride thermoluminescent dosimeter (TLD) chips for urologist dose measurements. The TLD technique was also used for some patient dose measurements (n = 7) for comparison with the tube output technique. Mean entrance skin doses of 191 and 117 mGy were measured by the tube output technique for anterior-posterior (AP) and right anterior oblique (RAO) 30 degrees /left anterior oblique (LAO) 30 degrees projections, respectively. The mean urologist doses for eye, finger and collar were measured as 26, 33.5 and 48 microGy per procedure, respectively. The mean effective dose per procedure for the urologist was 12.7 microSv. None of the individual skin dose results approach deterministic levels.


Assuntos
Carga Corporal (Radioterapia) , Nefrostomia Percutânea/estatística & dados numéricos , Exposição Ocupacional/análise , Pacientes/estatística & dados numéricos , Médicos/estatística & dados numéricos , Monitoramento de Radiação/estatística & dados numéricos , Radiografia Intervencionista/estatística & dados numéricos , Urologia/estatística & dados numéricos , Humanos , Doses de Radiação , Proteção Radiológica/métodos , Proteção Radiológica/estatística & dados numéricos , Turquia/epidemiologia
3.
Am J Otolaryngol ; 24(4): 271-3, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12884223

RESUMO

Bilateral simultaneous facial paralysis is an extremely rare clinical entity. Unlike the unilateral form, bilateral facial paralysis seldom falls into Bell's category. It is most often a special finding in a symptom complex of a systemic disease; many of them are potentially life-threatening, and therefore the condition warrants urgent medical intervention. Lyme disease, Guillian-Barre syndrome, Bell's palsy, leukemia, sarcoidosis, bacterial meningitis, syphilis, leprosy, Moebius syndrome, infectious mononucleosis, and skull fracture are the most common cause of bilateral facial paralysis. Here we present a 16-year-old patient with bilateral simultaneous Bell's palsy.


Assuntos
Paralisia de Bell/fisiopatologia , Adolescente , Paralisia de Bell/etiologia , Humanos , Masculino
4.
Int J Pediatr Otorhinolaryngol ; 67(8): 867-72, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12880666

RESUMO

OBJECTIVES: To present our experience in the surgical treatment of cholesteatoma in children. STUDY DESIGN: Retrospective clinical trial. PATIENTS AND METHOD: Charts of 114 patients who met the inclusion criteria of the study were examined. Surgical results were compared with respect to applied surgical methods. Cholesteatoma recidivism (CR) and hearing improvement were the main parameters which were examined. RESULTS: The mean age was 13 years and mean follow-up period was 3.7 years. A total of 200 operations performed on 114 children: 114 children operated at the first stage, 84 children underwent a second surgery, and 2 a third surgery. At initial operation; canal wall-up (CWU) tympanomastoidectomy was the choice of surgical procedure in 35 (31%) patients, and canal wall-down (CWD) tympanomastoidectomy was preferred for the other 79 (69%) patients. At final analysis; 26 of 114 (23%) patients had CWU procedure, 67 patients (59%) had CWD procedure and 21 patients (18%) had radical mastoidectomy. (CR) rate was 26 and 16%, respectively for CWU and CWD procedures for initial surgeries (P = 0.248). Hearing improvement was achieved in 36% of CWU procedures and 38% of CWD procedures (P = 0.957). Hearing deterioration was observed in 36% of CWU procedures and 47% of CWD procedures (P = 0.328). CONCLUSION: There was no significant difference between CWU and CWD procedures with respect to CR, hearing improvement, and hearing deterioration. Therefore, choose of surgical procedure should be individualized for each patient. In our opinion; open techniques must be employed in the presence of extensive disease, whereas the closed technique is reserved for those with a more localized problem.


Assuntos
Colesteatoma da Orelha Média/cirurgia , Meato Acústico Externo/cirurgia , Processo Mastoide/cirurgia , Procedimentos Cirúrgicos Otológicos/métodos , Adolescente , Criança , Pré-Escolar , Colesteatoma da Orelha Média/fisiopatologia , Tomada de Decisões , Feminino , Audição , Perda Auditiva/etiologia , Humanos , Masculino , Procedimentos Cirúrgicos Otológicos/efeitos adversos , Reoperação , Estudos Retrospectivos , Resultado do Tratamento
6.
Int J Pediatr Otorhinolaryngol ; 65(3): 213-8, 2002 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-12242136

RESUMO

OBJECTIVE: To evaluate the characteristics of antrochoanal polyps (ACPs) in children. METHODS: 10 children operated for ACP were investigated retrospectively. Demographic characteristics, surgical and histopathological findings were evaluated. RESULTS: The mean age was 10.2 years. The antral part of ACP was removed through middle meatal antrostomy in four patients, and transcanine sinuscopy was needed in six patients. It was found that the polyp passed through the main ostium in seven patients and accessory ostium in three patients. The antral part of the polyp was found to be cystic in six patients and polypoid in four patients. There was recurrence of polyps during follow-up period in two cases in which antral part of the polyp was seen to be removed through middle meatal antrostomy during primary surgery. In histologic examination, prominent eosinophilia was detected only in one patient and no mucous gland was detected in any patient. CONCLUSION: Endoscopic surgery through the middle meatal antrostomy combined with transcanine sinuscopy ensures the complete removal of the antral part of ACP in children.


Assuntos
Carcinoma de Células Escamosas/cirurgia , Endoscopia/métodos , Neoplasias do Seio Maxilar/cirurgia , Pólipos Nasais/cirurgia , Adolescente , Carcinoma de Células Escamosas/patologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Seio Maxilar/cirurgia , Neoplasias do Seio Maxilar/patologia , Pólipos Nasais/patologia , Recidiva Local de Neoplasia/cirurgia , Estudos Retrospectivos
7.
J Neurovirol ; 7(4): 288-92, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11517404

RESUMO

The lytic phase of JC virus (JCV) appears to be highly complex and remains elusive. A growing body of experimental evidence suggests that the regulation of JCV gene expression and replication requires, in addition to the presence of specific transcription factors, cooperativity between viral and cellular regulatory proteins. This cooperativity may be accomplished by physical interaction of the participant proteins on and/or off the viral DNA sequence. Here, we present evidence of specific physical and functional interaction between a cellular factor, YB-1, and the JCV early protein, T-antigen, and showed that both proteins play important roles in JCV gene transcription. Additionally, our data indicate that YB-1 also functionally interact with another viral protein, designated agnoprotein, which is expressed late during the course of infection, adding further complexity to the currently known picture on JCV gene regulation.


Assuntos
Proteínas de Ligação a DNA , Regulação Viral da Expressão Gênica/fisiologia , Vírus JC/genética , Fatores de Transcrição , Ativação Transcricional/fisiologia , Proteínas Virais/genética , Antígenos Virais de Tumores/genética , Proteínas Estimuladoras de Ligação a CCAAT/genética , Fatores de Transcrição NFI , Proteínas Nucleares , Proteínas Virais Reguladoras e Acessórias , Proteína 1 de Ligação a Y-Box
8.
Exp Cell Res ; 265(2): 221-33, 2001 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-11302687

RESUMO

Glioblastoma multiforme is a highly malignant and anaplastic tumor of the central nervous system representing more than 50% of all malignant gliomas. The cell origin of this highly undifferentiated tumor remains obscure, although it is postulated that glioblastomas are developed from astrocytes. The rapid growth of the glioma and the state of its undifferentiation are attributed to the deregulation of several signal transduction pathways and cell cycle events. Recent studies showed diverse functions for the NF-kappa B/Rel family of inducible transcription factors including differentiation, apoptosis, oncogenesis, and cell cycle regulation. We sought to examine the level of NF-kappa B activity throughout the glioma's cell cycle. Results from band-shift studies indicated a biphasic NF-kappa B DNA-binding activity in the nuclei of cycling glioblastoma cells. We showed that NF-kappa B-binding activity maximizes in nuclear extracts at specific cell cycle stages including G0/G1, mid-late G1, and S phase. Results from Northern blotting studies revealed that the differential expression of the NF-kappa B subunits, p50 and p65, may not be responsible for cell cycle stage-specific association of NF-kappa B subunits with DNA. However, results from Western blotting analysis utilizing nuclear extracts from glioma cells throughout the cell cycle demonstrated that the nuclear accumulation of p50 and p65 perfectly correlates with their DNA-binding activity. These observations suggest that the nuclear translocation of the p50/p65 subunit of NF-kappa B in glioma cells is cell cycle stage-dependent and that is distinct from the differential mRNA expression of these genes during glioma cell cycling. The possible role of NF-kappa B in glioma cell formation and regulation of cellular genes by NF-kappa B in these tumor cells is discussed.


Assuntos
Ciclo Celular/fisiologia , Glioblastoma/metabolismo , NF-kappa B/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Transcrição/metabolismo , Transporte Ativo do Núcleo Celular/fisiologia , Astrocitoma/metabolismo , Western Blotting , Núcleo Celular/metabolismo , Separação Celular , Meios de Cultura Livres de Soro , DNA/metabolismo , Citometria de Fluxo , Humanos , Microscopia de Fluorescência , Subunidades Proteicas , RNA/metabolismo , Células Tumorais Cultivadas
9.
J Virol ; 75(3): 1476-86, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11152520

RESUMO

In addition to encoding the structural and regulatory proteins, many viruses encode auxiliary proteins, some of which have been shown to play important roles in lytic and latent states of the viruses. The human neurotropic JC virus (JCV) genome encodes an auxiliary protein called Agno whose function remains unknown. Here, we investigated the functional role of JCV Agno protein on transcription and replication of the viral genome in glial cells. Results from transfection of human glial cells showed that Agno protein suppresses both T-antigen-mediated transcription of the viral late gene promoter and T-antigen-induced replication of viral DNA. Affinity chromatography and coimmunoprecipitation assays demonstrated that the Agno protein and T antigen physically interact with each other. Through the use of a series of deletion mutants, we demonstrated that the T-antigen-interacting region of Agno protein is localized to its amino-terminal half and the Agno-interacting domain of T antigen maps to its central portion. Furthermore, utilizing various Agno deletion mutants in functional studies, we confirmed the importance of the Agno-T antigen interaction in the observed down-modulation of T antigen function upon viral gene transcription and DNA replication by Agno protein. Taken together these data suggest that the Agno protein of JCV, which is produced late during the late phase of the lytic cycle, can physically and functionally interact with the viral early protein, T antigen, and downregulate viral gene expression and DNA replication. The importance of these observations in the lytic cycle of JCV is discussed.


Assuntos
Antígenos Transformantes de Poliomavirus/fisiologia , Replicação do DNA , Genoma Viral , Vírus JC/fisiologia , Neuroglia/virologia , Proteínas Virais/fisiologia , Replicação Viral , Sequência de Aminoácidos , Animais , Cricetinae , Vírus JC/genética , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Transcrição Gênica , Células Tumorais Cultivadas
10.
Ear Nose Throat J ; 80(11): 824-30, 833, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11816894

RESUMO

Necrotizing fasciitis is a potentially fatal soft-tissue infection that occurs only rarely in the head and neck region. Broad-spectrum parenteral antibiotics and surgical debridement are the mainstays of treatment. Until now, only eight cases of necrotizing fasciitis secondary to peritonsillar abscess have been described in the English-language literature. In this article, we report a new case that occurred in an otherwise healthy 43-year-old woman. In addition to standard treatment, the patient underwent a hot tonsillectomy. After 23 months of follow-up, she is in good health.


Assuntos
Fasciite Necrosante/etiologia , Abscesso Peritonsilar/complicações , Adulto , Idoso , Antibacterianos/uso terapêutico , Clindamicina/uso terapêutico , Fasciite Necrosante/cirurgia , Feminino , Infecções por Bactérias Gram-Negativas/complicações , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Positivas/complicações , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Infecções Oportunistas/complicações , Penicilinas/uso terapêutico
11.
Acta Otolaryngol ; 121(8): 925-9, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11813896

RESUMO

We compared the outcomes of two different regimens--azithromycin and pseudoephedrine hydrochloride (PHCl)--for the treatment of otitis media with effusion (OME) in children. In a double-blind randomized clinical study, a total of 90 children aged between 2 and 13 years with persistent OME were randomly assigned to one of 3 treatment groups. The first group received azithromycin at a dose of 10 mg/kg once daily for 3 days and this regimen was repeated weekly for up to 12 weeks according to the results of tympanometry and pneumatic otoscopy. The second group received azithromycin at a dose of 10 mg/kg once daily for 3 days for the first week, and this regimen was repeated for 1 day a week for the following 11 weeks. The third group received PHCl, 4 mg/kg, 3 times daily for up to 12 weeks. Each patient underwent pneumatic otoscopic and tympanometric investigations at baseline and at Weeks 4, 8 and 12. The outcomes in the azithromycin-treated groups were superior to that in the decongestant group. However, the difference between the outcomes in the azithromycin groups according to the treatment protocol was not statistically significant. Azithromycin therapy, particularly a once-weekly regimen, helps patients to comply with treatment and also helps us to achieve good results with minimal therapy.


Assuntos
Adrenérgicos/uso terapêutico , Antibacterianos/uso terapêutico , Azitromicina/uso terapêutico , Efedrina/uso terapêutico , Otite Média com Derrame/tratamento farmacológico , Testes de Impedância Acústica/métodos , Adolescente , Adrenérgicos/administração & dosagem , Antibacterianos/administração & dosagem , Azitromicina/administração & dosagem , Criança , Pré-Escolar , Efedrina/administração & dosagem , Feminino , Seguimentos , Infecções por Haemophilus/microbiologia , Humanos , Masculino , Infecções por Neisseriaceae/microbiologia , Otite Média com Derrame/microbiologia , Estudos Retrospectivos
12.
Int Urol Nephrol ; 33(4): 617-8, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-12452610

RESUMO

Angiomyolipoma with extrarenal involvement is very uncommon. Herein we report a case of angiomyolipoma with lymph node involvement in a 17-year-old female. The diagnosis and treatment of the case is discussed.


Assuntos
Angiomiolipoma/patologia , Carcinoma de Células Renais/diagnóstico , Neoplasias Renais/patologia , Adolescente , Angiomiolipoma/diagnóstico , Feminino , Humanos , Neoplasias Renais/diagnóstico , Metástase Linfática
13.
Urol Int ; 65(3): 163-6, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11054036

RESUMO

Renomedullary interstitial cell tumor was first introduced by Lerman and co-workers. These lesions have been referred to as medullary fibromas. The ultrastructural studies showed that the spindle cells throughout the stroma have the features of medullary interstitial cells. These benign tumors with specific histology are rare since they are incidental findings at autopsies. We report here a case of renomedullary interstitial cell tumor in a 55-year-old woman.


Assuntos
Fibroma/patologia , Medula Renal/patologia , Neoplasias Renais/patologia , Feminino , Fibroma/cirurgia , Humanos , Neoplasias Renais/cirurgia , Pessoa de Meia-Idade , Nefrectomia
14.
Urology ; 56(1): 121-4, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10869639

RESUMO

OBJECTIVES: To report our initial experience with extraperitoneal bladder neck suspension for female stress incontinence due to urethral hypermobility. METHODS: Between September 1996 and September 1999, 35 patients (mean age 49.5 years) underwent extraperitoneal bladder neck suspension at our institution. An extraperitoneal space was created by a trocar-mounted balloon device, and suspension was created using a 5-mm endoscopic hernia stapler and polypropylene mesh. RESULTS: The mean operative time was 39.5 minutes. In 2 patients, the bladder was inadvertently perforated during the bladder neck dissection. The perforation was repaired by laparoscopic suture ligation. The mean urethral catheterization and hospitalization time was 2.1 and 2.3 days, respectively. Urethral recatheterization because of temporary urinary retention was required in 11.4% of the patients. Symptoms of bladder instability were experienced by 13.5% of the patients in the early postoperative period. A total of 28 patients (80.0%) reported that they were totally dry after a mean of 23.2 months. CONCLUSIONS: Extraperitoneal bladder neck suspension using hernia mesh and a stapler seems to be an effective and safe procedure, with a shorter operative time, in selected patient groups.


Assuntos
Telas Cirúrgicas , Suturas , Incontinência Urinária por Estresse/cirurgia , Adulto , Idoso , Feminino , Seguimentos , Humanos , Laparoscopia/métodos , Pessoa de Meia-Idade
15.
Am J Otolaryngol ; 21(3): 179-83, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10834552

RESUMO

PURPOSE: We designed a computerized tomography (CT)-based silastic implant preparation method that enabled custom fit to the individual size of the patient's larynx for medialization laryngoplasty. MATERIALS AND METHODS: Three women with unilateral vocal cord paralysis underwent type I thyroplasty operation. The individual size of the patient's larynx was determined by preoperative measurements on CT scan and the implant was prepared accordingly. The implant was then inserted through a rectangular window at the level of vocal cords which had been outlined according to CT findings. RESULTS: Three patients, who were age 41, 25, and 37 years, underwent medialization laryngoplasty by this technique. They were followed up for 37, 16, and 4 months, respectively. There was not any rejection reaction, and satisfactory functional results with 10, 7, and 9 seconds of phonation duration have been achieved, respectively. CONCLUSION: In this technique, the desired medialization of the paralyzed vocal cord was accomplished by the first insertion of the implant. Thus, the duration of the operation and the vocal cord edema aroused by manipulation of the inner perichondrium and internal laryngeal structures were reduced.


Assuntos
Implantação de Prótese , Cartilagem Tireóidea/diagnóstico por imagem , Cartilagem Tireóidea/cirurgia , Tomografia Computadorizada por Raios X , Paralisia das Pregas Vocais/cirurgia , Adulto , Feminino , Seguimentos , Rouquidão/diagnóstico , Humanos , Complicações Pós-Operatórias/diagnóstico , Qualidade da Voz
16.
J Virol ; 73(12): 10146-57, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10559330

RESUMO

Y-box binding protein YB-1 is a member of a family of DNA and RNA binding proteins which have been shown to affect gene expression at both the transcriptional and translational levels. We have previously shown that YB-1 modulates transcription from the promoters of the ubiquitous human polyomavirus JC virus (JCV). Here we investigate the physical and functional interplay between YB-1 and the viral regulatory protein large T antigen (T-antigen), using JCV as a model system. Results of mobility band shift assays demonstrated that the efficiency of binding of YB-1 to a 23-bp single-stranded viral target sequence was significantly increased when T-antigen was included in the binding reaction mixture. Affinity chromatography and coimmunoprecipitation assays demonstrated that YB-1 and T-antigen physically interact with each other. Additionally, results of transcription studies demonstrated that these two proteins interact functionally on the JCV early and late gene promoters. Whereas ectopic expression of YB-1 and T-antigen results in synergistic transactivation of the viral late promoter, YB-1 alleviates T-antigen-mediated transcriptional suppression of the viral early promoter activity. Furthermore, we have localized, through the use of a series of deletion mutants, the sequences of these proteins which are important for their interaction. The T-antigen-interacting region of YB-1 is located in the cold shock domain of YB-1 and its immediate flanking sequences, and the YB-1-interacting domain of T-antigen maps to the carboxy-terminal half of T-antigen. Results of transient transfection assays with various YB-1 mutants and T-antigen expression constructs confirm the specificity of the functional interaction between YB-1 and T-antigen. Taken together, these data demonstrate that the cellular factor YB-1 and the viral regulatory protein T-antigen interact both physically and functionally and that this interaction modulates transcription from the JCV promoters.


Assuntos
Antígenos Transformantes de Poliomavirus/metabolismo , Proteínas Estimuladoras de Ligação a CCAAT , Proteínas de Ligação a DNA/metabolismo , Regulação Viral da Expressão Gênica , Vírus JC/genética , Fatores de Transcrição/metabolismo , Animais , Antígenos Transformantes de Poliomavirus/genética , Antígenos Transformantes de Poliomavirus/fisiologia , Sítios de Ligação , Cricetinae , DNA Viral/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/fisiologia , Humanos , Mutagênese , Fatores de Transcrição NFI , Proteínas Nucleares , Regiões Promotoras Genéticas , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes de Fusão/fisiologia , Fatores de Transcrição/genética , Fatores de Transcrição/fisiologia , Células Tumorais Cultivadas , Proteína 1 de Ligação a Y-Box
17.
Virology ; 262(1): 178-89, 1999 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-10489351

RESUMO

The regulatory region of the human neurotropic JC virus (JCV) is composed of several cis-acting motifs that confer cell type specificity to viral gene transcription and enable the viral promoters to respond to extracellular stimuli. For example, the bidirectional 98-bp tandem repeat sequences, positioned between the JCV early and late genes, were shown to be responsible for basal and activated levels of viral gene transcription in central nervous system (CNS) cells. Additionally, the NF-kappaB site located approximately 75 bp from the repeats on the early side of the viral genome was also found to influence both levels of viral transcription. Recently, we isolated a novel JCV variant, JCV(Phila-1), from a clinical specimen that contains a 23-bp sequence element (23-bpse) within its promoter-enhancer region. Here we demonstrate that this element is responsive to an extracellular stimulatory factor, such as phorbol 12-myristate 13-acetate (PMA), and can augment the basal levels of the viral early and to a lesser degree late promoter activities in cells derived from the CNS. The 23-bpse, by associating with nuclear proteins present in uninduced cells, forms a 40-kDa DNA-protein complex. Although no direct correlation between transcriptional enhancement of the JCV promoter by PMA treatment and the level of the 40-kDa DNA-protein complex was observed, results from site-directed mutagenesis indicated that formation of this complex is critical for the transcriptional activation of the viral promoter by PMA. These observations suggested that transcriptional enhancement of the JCV promoter activity upon PMA treatment may be an indirect event and mediated by an intermediary factor(s). In this respect, we demonstrated that overexpression of the inducible NF-kappaB subunits, p50 and p65, enhanced transcriptional activity of the JCV promoter through the 23-bp region with no evidence for their direct association with the 23-bpse DNA. Of importance, the p50/p65-induced JCV promoter activity requires the nucleotide sequences within the 23-bpse that are critical for the assembly of the 40-kDa DNA-protein complex. Thus, it is likely that the NF-kappaB subunits, by recruiting the cellular factors such as those associated with the 40-kDa DNA-protein complex, influence the basal level of the viral gene transcription. The implications of these findings with respect to regulation of viral and cellular genomes by extracellular stimuli and NF-kappaB pathway are discussed.


Assuntos
Vírus JC/metabolismo , NF-kappa B/fisiologia , Elementos de Resposta/fisiologia , Composição de Bases , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Eletroforese em Gel de Poliacrilamida , Humanos , Vírus JC/efeitos dos fármacos , Vírus JC/genética , Mutagênese Sítio-Dirigida/efeitos dos fármacos , Mutagênese Sítio-Dirigida/genética , NF-kappa B/metabolismo , Subunidade p50 de NF-kappa B , Neuroglia/efeitos dos fármacos , Neuroglia/virologia , Proteínas Nucleares/metabolismo , Regiões Promotoras Genéticas/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/metabolismo , Acetato de Tetradecanoilforbol/análogos & derivados , Acetato de Tetradecanoilforbol/farmacologia , Timidina Quinase/antagonistas & inibidores , Timidina Quinase/metabolismo , Fator de Transcrição RelA
18.
Mol Cell Biol ; 19(4): 2712-23, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10082537

RESUMO

Cross communication between regulatory proteins is an important event in the control of eukaryotic gene transcription. Here we have examined the structural and functional interaction between two cellular regulatory proteins, YB-1 and Puralpha, on the 23-bp sequence element derived from the enhancer-promoter of the human polyomavirus JCV. YB-1 and Puralpha are single-stranded DNA binding proteins which recognize C/T- and GC/GA-rich sequences, respectively. Results from band shift studies demonstrated that while both proteins interact directly with their DNA target sequences within the 23-bp motif, each protein can regulate the association of the other one with the DNA. Affinity chromatography and coimmunoprecipitation provide evidence for a direct interaction between Puralpha and YB-1 in the absence of the DNA sequence. Ectopic expression of YB-1 and Puralpha in glial cells synergistically stimulated viral promoter activity via the 23-bp sequence element. Results from mutational studies revealed that residues between amino acids 75 and 203 of YB-1 and between amino acids 85 and 215 of Puralpha are important for the interaction between these two proteins. Functional studies with glial cells indicated that the region within Puralpha which mediates its association with YB-1 and binding to the 23-bp sequence is important for the observed activation of the JCV promoter by the Puralpha and YB-1 proteins. The results of this study suggest that the cooperative interaction between YB-1 and Puralpha mediates the synergistic activation of the human polyomavirus JCV genome by these cellular proteins. The importance of these findings for cellular and viral genes which are regulated by Puralpha and YB-1 is discussed.


Assuntos
Proteínas Estimuladoras de Ligação a CCAAT , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação Viral da Expressão Gênica , Vírus JC/genética , Neuroglia/virologia , Fatores de Transcrição , Sítios de Ligação , Elementos Facilitadores Genéticos , Fatores de Transcrição NFI , Proteínas Nucleares , Regiões Promotoras Genéticas , Ligação Proteica , Ativação Transcricional , Proteína 1 de Ligação a Y-Box
19.
J Biol Chem ; 273(49): 32662-9, 1998 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-9830007

RESUMO

Large T-antigen, the major regulatory protein encoded by polyomaviruses, including Simian Virus 40 (SV40) and JC virus (JCV), is a multifunctional phosphoprotein that is involved in many viral and cellular events. In addition to its integral role in viral replication and cellular transformation, T-antigen also regulates transcription of both viral and cellular genes. In particular, the viral late promoter has been used as a model for the analysis of T-antigen-mediated transcriptional activation. Earlier studies have demonstrated that the cellular protein Puralpha is able to attenuate the transcriptional activity of JCV T-antigen. We investigated the mechanism whereby Puralpha affects T-antigen function. Co-immunoprecipitation studies demonstrated that Puralpha and JCV T-antigen associate in vivo, and glutathione S-transferase affinity binding assays revealed that these two proteins interact in vitro. Moreover, we localized the sequences of Puralpha that are important for the interaction between Puralpha and JCV T-antigen. In addition, we demonstrated that Puralpha interacts with the SV40 T-antigen. Transient transfection studies demonstrated that Puralpha and JCV T-antigen interact functionally as well. More specifically, Puralpha and a deletion mutant that interacts with T-antigen attenuated T-antigen-mediated transcriptional activation. A Puralpha deletion mutant that is unable to interact with JCV T-antigen, however, was found to be incapable of abrogating JCV T-antigen transactivation. Taken together, these data demonstrate that Puralpha and T-antigen interact both physically and functionally and that this interaction modulates T-antigen-mediated transcriptional activation. The implication of these findings with respect to the cellular role of Puralpha is discussed.


Assuntos
Antígenos Transformantes de Poliomavirus/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico , DNA de Cadeia Simples/metabolismo , Proteínas de Ligação a DNA/metabolismo , Vírus JC/imunologia , Linhagem Celular Transformada , Humanos , Vírus JC/genética , Regiões Promotoras Genéticas , Ligação Proteica , Deleção de Sequência , Fatores de Transcrição , Ativação Transcricional , Células Tumorais Cultivadas
20.
Urol Int ; 60(3): 202-4, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9644798

RESUMO

We have the opportunity to present a rare case of late local recurrence after treatment of intrascrotal extratesticular malignant schwannoma with rhabdomyoblastic features in an adult man. As our case is the first in the literature, we want to inform the reader about the long-term follow-up of our patient and suggest that these tumors may have a long survival and late recurrences may occur even after 5 years postoperatively.


Assuntos
Recidiva Local de Neoplasia , Neurilemoma/terapia , Neoplasias Testiculares/terapia , Quimioterapia Adjuvante , Doxorrubicina/uso terapêutico , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Neurilemoma/diagnóstico por imagem , Neurilemoma/patologia , Orquiectomia , Escroto/patologia , Neoplasias Testiculares/diagnóstico por imagem , Neoplasias Testiculares/patologia , Fatores de Tempo , Ultrassonografia
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