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INTRODUCTION: The purpose of this study is to identify the risk factors and risk classification associated with the conversion from mild cognitive impairment (MCI) to Alzheimer's disease (AD) dementia to facilitate early intervention and the design of clinical trials for AD. METHODS: The study comprised a prospective cohort study of 400 subjects with MCI who had annual follow-ups for 3 years. RESULTS: During an average follow-up period of 3.5 years, 109 subjects were diagnosed with all cause of dementia, of whom 104 subjects converted to Alzheimer's dementia and 5 subjects converted to other types of dementia. The cumulative conversion rate was 5.5% (95% CI: 3.4, 8.6), 16.3% (95% CI: 12.9, 21.1), and 31.0% (95% CI: 25.4, 36.5) in each of the first 3 follow-up years, respectively. The factors associated with a greater risk of conversion from MCI to AD included smoking status, ApoE4 carrier status, right hippocampal volume (rt. HV), left temporal lobe volume, and scores on the Revised Chinese version of the Alzheimer's Disease Assessment Scale-Cognitive Subscale 13 (ADAS-Cog-C). The risk classification of the ADAS-Cog-C or Preclinical Alzheimer Cognitive Composite (PACC) score combined with the rt. HV showed a conversion difference among the groups at every annual follow-up. CONCLUSION: A simple risk classification using the rt. HV and neuropsychological test scores, including those from the ADAS-Cog-C and PACC, could be a practicable and efficient approach to indentify individuals at risk of all-cause dementia.
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Doença de Alzheimer , Disfunção Cognitiva , Humanos , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/psicologia , Estudos de Coortes , Estudos Prospectivos , China/epidemiologia , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/psicologia , Testes NeuropsicológicosRESUMO
PURPOSE: We evaluated the treatment outcomes of different prostate volumes (PVs), <15 cc, 15-20 cc, and > 20 cc, in patients with prostate cancer who underwent permanent seed implantation (PI) ± external beam radiation therapy ± hormone therapy in a national Japanese prospective cohort study (J-POPS). METHODS AND MATERIALS: Of the 6721 patients in J-POPS from 2005 to 2011, 6652 were included in the analysis population. We categorized the patients into the following three PV groups: <15 cc, 15-20 cc, and > 20 cc. We evaluated the effect of PV on biochemical freedom from failure (bFFF), prostate cancer-specific mortality (PCSM), and all-cause mortality (ACM) using the Phoenix definition and Cox proportional hazard models. RESULTS: The median follow-up period was 60.0 months. Patients in each PV group was 491 (7.4%), 1118 (16.8%), and 5043 (75.8%), respectively. No difference was observed in bFFF (94.7%, 96.2%, and 95.7%, p = 0.407), PCSM (99.8%, 99.7%, and 99.8%, p = 0.682), and ACM (98.2%, 96.7%, and 97.2%, p = 0.119) at 5 years for each PV group. In univariate and multivariate analyses, PV was not associated with bFFF, PCSM, ACM, or grade 2 toxicity. The percentage of positive biopsies was the single most significant predictor for all treatment outcomes. CONCLUSIONS: Our results obtained by analyzing a very large Japanese prospective database showed no difference in treatment outcomes according to PV (<15 cc, 15-20 cc, and Ë20 cc). Our study confirmed that PI in small prostates (even < 15 cc) remains an effective treatment option.
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PURPOSE: We evaluated the effect of age, <60 and ≥60 years, on biochemical outcomes and toxicities in patients with prostate cancer who underwent permanent seed implantation (PI) ± external beam radiation therapy ± hormone therapy in a national Japanese prospective cohort study (J-POPS). METHODS AND MATERIALS: The safety and efficacy analyses included 6721 and 6662 patients, respectively. We categorized patients into two age groups: <60 (nâ¯=â¯716) and ≥60 (nâ¯=â¯6,005) years. We used propensity score matching (PSM) to estimate the marginal effect of age on biochemical freedom from failure (bFFF) using a Phoenix definition and Cox proportional hazard models. RESULTS: The median followup period was 60.0 months. Without PSM, men <60 years demonstrated similar 5-year bFFF (96.3%) compared with men ≥60 years (95.6%; pâ¯=â¯0.576); percent positive biopsies, biologically effective dose, Gleason score, risk classification, and supplemental external beam radiation therapy (p <0.001, <0.001, <0.001, 0.008, and <0.001) were significantly associated with bFFF while age was not (pâ¯=â¯0.576). With PSM, bFFF was not significantly different between age groups (pâ¯=â¯0.664); however, men <60 years showed a significantly lower incidence of declining erectile function, grade ≥2 all urinary toxicities, urinary frequency/urgency, and rectal bleeding (p <0.001, 0.024, 0.031, and 0.010) than men ≥60 years. CONCLUSIONS: After PI, men <60 years achieved a comparable 5-year biochemical control rate and showed a lower incidence of several toxicities compared to men ≥60 years. This suggests that PI should be an excellent treatment option for men <60 years with prostate cancer.
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Braquiterapia , Neoplasias da Próstata , Masculino , Humanos , Pessoa de Meia-Idade , Antígeno Prostático Específico/uso terapêutico , Estudos Prospectivos , Braquiterapia/métodos , Neoplasias da Próstata/patologia , Seguimentos , Resultado do TratamentoRESUMO
PURPOSE: To evaluate long-term health-related quality of life (HRQOL) impact of I-125 permanent seed implantation (PI) in Japanese patients with localized prostate cancer. MATERIALS AND METHODS: This is a longitudinal, prospective study of 2353 patients who enrolled in the nationwide Japanese-Prostate Cancer Outcome Study by Permanent I-125 Seed Implantation (J-POPS) from July 2005 to June 2007. HRQOL was measured before and after treatment (3, 12, 24, and 36 months) using the Medical Outcomes Study 8-items Short-Form Health Survey (SF-8) and the Expanded Prostate Cancer Index Composite Japanese version questionnaire. RESULTS: Of the total of 1511 patients who returned anonymized HRQOL questionnaires to Translational Research Center for Medical Innovation, 1079 underwent PI alone (PI group) and 432 underwent combined PI and external beam radiation therapy (EBRT) treatment (EBRT combination therapy group). The mental component summary score of SF-8 was improved at 12, 24, and 36 months compared with the pretreatment level. Although the urinary summary score at 3 months in the PI group was significantly lower than that in the EBRT combination therapy group, which recovered thereafter and was comparable to the score of the EBRT combination therapy group. The bowel summary score in the PI group was significantly higher than that in the EBRT combination therapy group at 12, 24, and 36 months. CONCLUSION: This longitudinal, large-scale prospective study indicated that the general HRQOL for PI was almost maintained 3 years after treatment. These results provide important information for patients with localized prostate cancer, who may select to receive I-125 brachytherapy.
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Braquiterapia/métodos , Radioisótopos do Iodo/administração & dosagem , Avaliação de Resultados em Cuidados de Saúde/métodos , Medidas de Resultados Relatados pelo Paciente , Neoplasias da Próstata/radioterapia , Qualidade de Vida , Idoso , Idoso de 80 Anos ou mais , Seguimentos , Humanos , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/epidemiologia , Taxa de Sobrevida/tendênciasRESUMO
PURPOSE: The purpose of this study was to evaluate acute and late genitourinary (GU) toxicity and to elucidate factors associated with GU toxicity in patients with prostate cancer treated with permanent seed implantation (PI) enrolled in a nationwide prospective cohort study in Japan. METHODS AND MATERIALS: Of 2,354 patients enrolled in this study, GU toxicity was evaluated in 2,339 patients at 3, 12, 24, and 36 months after PI. To elucidate independent factors predictive of acute and late Common Terminology Criteria for Adverse Events Grade 2 or higher (Grade ≥2) GU toxicity, multivariate logistic regression analyses were carried out. Regarding acute urinary retention (AUR), the incidence rate and the recovery rate for AUR were estimated using the Kaplan-Meier curve. RESULTS: Approximately 53% of the patients treated with PI alone and 42% of those treated with combination therapy with PI therapy and external beam radiation therapy showed urinary frequency/urgency at 3 months. The multivariate analysis revealed that age, prostate volume, pretreatment international prostate symptom score, drinking status, and PI were independent predictors of acute GU toxicity Grade ≥2. Of all patients, 53 (2.3%) suffered from AUR, and 49 (92.5%) recovered from AUR with a median time of 4.3 months during the followup period. CONCLUSIONS: The results of GU toxicity in Japanese patients who underwent low-dose-rate brachytherapy were acceptable and comparable to those previously reported in U.S. PATIENTS: The patients treated with PI alone showed a significantly higher incidence rate of GU toxicity than did those undergoing combination therapy with PI and external beam radiation therapy in the acute phase.
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Braquiterapia/efeitos adversos , Radioisótopos do Iodo/efeitos adversos , Neoplasias da Próstata/radioterapia , Lesões por Radiação/etiologia , Retenção Urinária/etiologia , Doença Aguda , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Braquiterapia/métodos , Terapia Combinada , Humanos , Radioisótopos do Iodo/uso terapêutico , Japão , Sintomas do Trato Urinário Inferior/etiologia , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Estudos Prospectivos , Fatores de Risco , Fatores de TempoRESUMO
A rapid detection method for Lactobacillus crispatus and Lactobacillus iners, which are important for maintaining a healthy vaginal environment, was developed using loop-mediated isothermal amplification (LAMP). The LAMP assay had a lower limit of detection of 10â¯fg DNA and could detect both species within 45â¯min.
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Lactobacillus crispatus/isolamento & purificação , Lactobacillus/isolamento & purificação , Técnicas de Amplificação de Ácido Nucleico , Vagina/microbiologia , Vaginose Bacteriana/microbiologia , Primers do DNA/genética , Feminino , Humanos , Lactobacillus/genética , Lactobacillus crispatus/genética , Limite de Detecção , RNA Ribossômico 16S/genética , TemperaturaRESUMO
BACKGROUND & OBJECTIVE: The purpose of this study is to identify the risk factors associated with the conversion from Mild Cognitive Impairment (MCI) to Alzheimer's Disease (AD) dementia for the early detection of AD. METHODS: The study comprised a prospective cohort study that included 400 MCI subjects with annual follow-ups for 3 years. RESULTS: During the first 12 months' follow-up, 42 subjects converted to Alzheimer's dementia (21 probable AD and 21 possible AD), two subjects converted to other types of dementia and 56 subjects lost follow. The factors associated with a greater risk of conversion from MCI to AD included gender, whole brain volume, and right hippocampal volume (rt. HV), as well as scores on the Revised Chinese version of the Alzheimer's Disease Assessment Scale-Cognitive subscale 13 (ADAS-Cog-C), Clock Drawing Test (CDT), Symbol Digit Modalities Test (SDMT), and Rey-Osterrieth Complex Figure Test (ROCFT). The risk classification of the combined ADAS-Cog-C and Alzheimer Cognitive Composite (ACC) score with the rt. HV and left Entorhinal Cortex Volume (lt. ECV) showed a conversion difference among the groups. CONCLUSION: Early detection of AD and potential selection for clinical trial design should utilize the rt. HV, as well as neuropsychological test scores, including those of the ADAS-Cog-C and ACC.
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Doença de Alzheimer/epidemiologia , Disfunção Cognitiva/epidemiologia , Idoso , Doença de Alzheimer/diagnóstico , Encéfalo/diagnóstico por imagem , China , Cidades , Disfunção Cognitiva/diagnóstico , Estudos de Coortes , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Fatores de RiscoRESUMO
The aim of this study was to develop a method for the rapid detection of Gardnerella vaginalis, which is proposed to play a key role in the pathogenesis of bacterial vaginosis. Specific loop-mediated isothermal amplification (LAMP) primers were designed and used to detect target DNA within 45 min under isothermal conditions. Comparative screening indicated that the LAMP assay is superior to PCR in terms of rapidity, and is equivalent in sensitivity and specificity. This LAMP assay can be used for rapid screening and detection of G. vaginalis in vaginal samples; the limit of detection is 10 fg DNA.
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Gardnerella vaginalis/isolamento & purificação , Infecções por Bactérias Gram-Positivas/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Adulto , Povo Asiático , Sequência de Bases , Primers do DNA , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Feminino , Gardnerella vaginalis/genética , Gardnerella vaginalis/patogenicidade , Genes Bacterianos/genética , Infecções por Bactérias Gram-Positivas/microbiologia , Humanos , RNA Ribossômico 23S/genética , Sensibilidade e Especificidade , Vaginose Bacteriana/diagnóstico , Vaginose Bacteriana/microbiologia , Adulto JovemRESUMO
Critical limb ischemia (CLI) is a devastating disease in patients undergoing hemodialysis (HD). Based on the unsatisfactory results of autologous mononuclear cell transplantation for patients with CLI undergoing HD, we conducted a phase II clinical trial to evaluate the safety and efficacy of granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood-derived autologous purified CD34 positive (CD34+) cell transplantation for CLI in patients undergoing HD. Six patients with CLI (two with Rutherford category 4 and four with Rutherford category 5) were enrolled. As for primary endpoint, there were no major adverse events related to this therapy. As for efficacy, the amputation-free survival rate was 100% at 1 year after cell therapy. Both rest pain scale and ulcer size were significantly improved as early as 4 weeks after therapy compared with baseline (p < .01), and three out of five ulcers completely healed within 12 weeks after cell transplantation. Clinical severity, including Fontaine scale and Rutherford category, significantly improved at 24 weeks after cell transplantation (p < .05), and further improved at 52 weeks (p < .01) compared with baseline. The improvement rate from CLI stage to non-CLI stage was 83.3% at 52 weeks. Toe skin perfusion pressure and absolute claudication distance were also significantly improved. In conclusion, G-CSF-mobilized peripheral blood CD34+ cell transplantation was safe, feasible, and effective for patients with CLI undergoing HD. Stem Cells Translational Medicine 2018;7:774-782.
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Células Progenitoras Endoteliais/transplante , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Isquemia/terapia , Falência Renal Crônica/patologia , Extremidade Inferior/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Amputação Cirúrgica , Antígenos CD34/metabolismo , Doenças Cardiovasculares/etiologia , Intervalo Livre de Doença , Células Progenitoras Endoteliais/citologia , Células Progenitoras Endoteliais/efeitos dos fármacos , Células Progenitoras Endoteliais/metabolismo , Feminino , Fator Estimulador de Colônias de Granulócitos/farmacologia , Humanos , Isquemia/etiologia , Falência Renal Crônica/complicações , Masculino , Pessoa de Meia-Idade , Doença Arterial Periférica/patologia , Doença Arterial Periférica/terapia , Diálise Renal , Transplante Autólogo/efeitos adversos , Resultado do TratamentoRESUMO
BACKGROUND: Investigating oncological outcomes in patients registered in the Japanese Prostate Cancer Outcome Study of Permanent Iodine-125 Seed Implantation (J-POPS) in terms of biochemical relapse-free survival (bRFS) by the Phoenix and the newly developed J-POPS definitions, exploration of predictive factors for bRFS, and preliminary verification of pitfalls of prostate-specific antigen (PSA) failure definitions. METHODS: Between July 2005 and June 2007, 2316 clinically localized patients underwent permanent seed implantation. The primary endpoint was bRFS. One of the secondary endpoints was overall survival (OS). RESULTS: The median age was 69 and performance status was 0 in 99.1% of participants. The median biologically effective dose (BED) was about 180 Gy2. During a median follow-up of 60.0 months, 8.4 and 5.9% had PSA failure by the Phoenix and the J-POPS definitions, respectively. The 5-year bRFSs based on the Phoenix and the J-POPS definitions were 89.1 and 91.6%, respectively. The 5-year OS was 97.3%. According to multivariate analyses, only age affected bRFS based on the Phoenix definition, whereas the risk group and BED independently affected bRFS based on the J-POPS definition. A spontaneous PSA decrease was seen in 91.1% of participants after PSA failure based on the Phoenix definition alone, but in only 22.2% after PSA failure based on the J-POPS definition alone. CONCLUSION: The world's largest registration study, J-POPS, consisted of patients with longevity, and a highly quality-controlled BED resulted in excellent bRFS and OS. The high likelihood of PSA bounce by the Phoenix definition should be taken into account, especially in younger patients. CLINICAL TRIAL INFORMATION: NCT00534196.
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Radioisótopos do Iodo/uso terapêutico , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/radioterapia , Idoso , Braquiterapia/métodos , Seguimentos , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Antígeno Prostático Específico , Neoplasias da Próstata/patologia , Fatores de Risco , Análise de Sobrevida , Resultado do TratamentoRESUMO
BACKGROUND: Mortality and morbidity of congenital tracheal stenosis (CTS) remain high. The aim of this study was to determine the factors predicting 12-month survival and 2-month successful extubation after tracheoplasty in patients with CTS. METHODS: Retrospective chart reviews were conducted in patients with CTS undergoing tracheoplasty at a single institution between 1997 and 2014. Patients' characteristics at disease onset and tracheoplasty were summarized. Twelve-month survival rate and 2-month extubation rate without tracheotomy after tracheoplasty were analyzed. RESULTS: We reviewed 81 patients' records. Multivariate analysis for 12-month survival revealed that older age (>2 months, hazard ratio [HR]: 0.08, 95% confidence interval [CI]: 0.02-0.36) or heavier body weight (>4.4 kg, HR: 0.13, 95% CI: 0.02-0.73) at tracheoplasty was a predictive factor for survival. Body weight at tracheoplasty (>8.2 kg, HR: 3.83, 95% CI: 1.88-7.79), preoperative balloon dilatation (HR: 0.30, 95% CI: 0.12-0.78), and carina involvement (HR: 0.36, 95% CI: 0.19-0.69) were predictive factors for successful extubation. CONCLUSIONS: Although CTS management is individualized, age or body weight at tracheoplasty needs to be considered and assessed for survival, as well as preoperative balloon dilatation, and carina involvement for successful extubation. LEVELS OF EVIDENCE: Level III.
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Constrição Patológica/mortalidade , Constrição Patológica/cirurgia , Procedimentos de Cirurgia Plástica/mortalidade , Traqueia/anormalidades , Humanos , Lactente , Recém-Nascido , Estudos Retrospectivos , Traqueia/cirurgia , Resultado do TratamentoRESUMO
OBJECTIVES: To evaluate male sexual function in Japanese prostate cancer patients undergoing permanent brachytherapy without endocrine treatment, using quality of life measures of the Expanded Prostate Cancer Index Composite. METHODS: A total of 482 patients were selected as analysis subjects from the nationwide database for the Japanese Prostate Cancer Outcome Study of Permanent Iodine-125 Seed Implantation. The patients were asked to complete the Expanded Prostate Cancer Index Composite questionnaires before and at 3, 12, 24, and 36 months after the permanent brachytherapy. Changes in their responses were analyzed, and any association of the outcomes was investigated. Furthermore, changes over time in their answers to Q18 (usual quality of your erections) were analyzed. RESULTS: A total of 72 patients (14.9%) had received external beam radiation. A total of 68 patients (14.1%) had taken any 5-phosphodiesterase inhibitor medications. Regarding Q18, 232 patients (48.2%) selected either "There was no sexual activity" or "There was no desire for erection" before receiving permanent brachytherapy. Of all the 482 patients, sexual function was preserved in 138 patients (28.7%) 3 years after permanent brachytherapy. Overall satisfaction has significantly improved without regard for the deterioration of sexual function. Significant factors for maintaining sexual activity were patient age and sexual activity before permanent brachytherapy. CONCLUSIONS: In Japanese patients undergoing permanent brachytherapy alone for prostate cancer, the sexual function is not well preserved. However, decreased sexual function does not seem to represent a major factor determining patients' overall satisfaction. These findings might be peculiar to Japanese patients, in whom elderly subjects account for the majority.
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Braquiterapia/efeitos adversos , Radioisótopos do Iodo/administração & dosagem , Ereção Peniana/efeitos da radiação , Neoplasias da Próstata/radioterapia , Comportamento Sexual/efeitos da radiação , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Braquiterapia/métodos , Terapia Combinada/efeitos adversos , Terapia Combinada/métodos , Humanos , Radioisótopos do Iodo/efeitos adversos , Japão , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Inibidores da Fosfodiesterase 5/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Qualidade de Vida , Comportamento Sexual/estatística & dados numéricos , Inquéritos e Questionários/estatística & dados numéricos , Resultado do TratamentoRESUMO
PURPOSE: To evaluate the incidence and the associated factors of rectal toxicity in patients with prostate cancer undergoing permanent seed implantation (PI) with or without external beam radiation therapy (EBRT) in a nationwide prospective cohort study in Japan (J-POPS) during the first 2 years. METHODS AND MATERIALS: A total of 2,339 subjects were available for the analyses. Rectal toxicity was evaluated using the National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. RESULTS: The 3-year cumulative incidence for grade ≥2 rectal toxicity was 2.88%, 1.76%, and 6.53% in all subjects, PI group and EBRT combination therapy group, respectively. On multivariate analysis, among all subjects, grade ≥2 rectal toxicity was associated with rectal volumes receiving 100% of the prescribed dose (R100; p < 0.0001) and EBRT combination therapy (p = 0.0066). R100 in the PI group (p = 0.0254), and R100 (p = 0.0011) and interactive planning (p = 0.0267) in the EBRT combination therapy group were also associated with grade ≥2 toxicity. The 3-year cumulative incidence of grade ≥2 rectal toxicity was 3.80% and 1.37% for R100 ≥ 1 mL and R100 < 1 mL, respectively, in the PI group (p = 0.0068), and 14.09% and 5.52% for R100 ≥ 1 mL and R100 < 1 mL, respectively, in the EBRT combination therapy group (p = 0.0070). CONCLUSIONS: Rectal toxicity was relatively rare in this study compared with previous reports. For Japanese prostate cancer patients, R100 < 1 mL in both PI and EBRT combination therapy groups and interactive planning in EBRT combination therapy group may be effective in decreasing the incidence of rectal toxicity.
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Braquiterapia/efeitos adversos , Radioisótopos do Iodo/efeitos adversos , Neoplasias da Próstata/radioterapia , Lesões por Radiação/epidemiologia , Reto/efeitos da radiação , Idoso , Idoso de 80 Anos ou mais , Braquiterapia/métodos , Humanos , Incidência , Radioisótopos do Iodo/uso terapêutico , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Estudos Prospectivos , Doses de Radiação , Lesões por Radiação/etiologia , Fatores de RiscoRESUMO
An alternatively spliced form of the presenilin 2 (PS2) gene lacking exon 5 (PS2V) was found in human brains with sporadic Alzheimer's disease. PS2V was induced by hypoxic stress in human neuroblastoma SK-N-SH cells, indicating that hypoxic stress affects the splicing machineries for PS2 exon 5. Here, we identified the critical cis-acting element (sec 2) on the PS2 pre-mRNA responsible for the aberrant splicing of PS2 exon 5 under hypoxic stress conditions. The element was composed of 23 nucleotides in exon 5 and RNA structural analyses showed a stem-loop structure in this sequence. Treatment with an antisense oligonucleotide directed toward the cis-acting element caused an increase in exon 5 inclusion. These results indicate that the sec 2 identified in this study is a novel regulatory element for exon 5 splicing under stress conditions and that trans-acting factors could specifically bind to the element to skip exon 5 of PS2.
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Processamento Alternativo , Éxons , Hipóxia/genética , Proteínas de Membrana/genética , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Encéfalo/metabolismo , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Éxons/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Hipóxia/metabolismo , Imuno-Histoquímica/métodos , Modelos Moleculares , Mutagênese , Neuroblastoma , Níquel , Nitrogênio , Oligorribonucleotídeos Antissenso/farmacologia , Presenilina-2 , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Estresse Fisiológico/genética , Estresse Fisiológico/metabolismo , Proteínas tau/genética , Proteínas tau/metabolismoRESUMO
Spinal muscular atrophy is caused by the homozygous loss of survival motor neuron 1 (SMN1). SMN2, a nearly identical copy gene, differs from SMN1 only by a single nonpolymorphic C to T transition in exon 7, which leads to alteration of exon 7 splicing; SMN2 leads to exon 7 skipping and expression of a nonfunctional gene product and fails to compensate for the loss of SMN1. The exclusion of SMN exon 7 is critical for the onset of this disease. Regulation of SMN exon 7 splicing was determined by analyzing the roles of the cis-acting element in intron 7 (element 2), which we previously identified as a splicing enhancer element of SMN exon 7 containing the C to T transition. The minimum sequence essential for activation of the splicing was determined to be 24 nucleotides, and RNA structural analyses showed a stem-loop structure. Deletion of this element or disruption of the stem-loop structure resulted in a decrease in exon 7 inclusion. A gel shift assay using element 2 revealed formation of RNA-protein complexes, suggesting that the binding of the trans-acting proteins to element 2 plays a crucial role in the splicing of SMN exon 7 containing the C to T transition.