C18. Docetaxel como quimioterapia de 2ª linha nos doentes com CPNPC: estudo prospectivo multicêntrico.

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A.S. Oliveira

2003-11-01

Full Text Available Durante cinco anos (1998-2002 foi realizado um estudo prospectivo com docetaxel (75 mg/m2 d1 3/3 semanas como tratamento de 2ª linha em doentes com CPNPC.Características: sexoM/F:94/15; idade:58.6(33-74; SP£1:96(88%; histologia: adenocarcinoma-52,pavimento-celular-41; estadio IIIB/ IV:19/90. 94% tratados inicialmente com derivados da platina.Administrados 355 ciclos de docetaxel (3.3/doente. RP em 21 doentes (19.3% IC 95% 11.7-26.8 e estabilização em 36(33%. Ausência de correlação entre resultados com quimioterapia de 1ª linha (taxa de resposta/intervalo até progressão e taxa de resposta ao docetaxel.Neutropenia grau ¾: 52 doentes (48%; 4:neutropenia febril; uma morte tóxica. Efeitos adversos não-hematológicos: alopécia (59%, astenia (28% e polineuropatia (22%.Sobrevivência mediana global: 12.7 meses, sobrevivência pósdocetaxel:6.1 meses, tempo até progressão:12 semanas e taxas de sobrevivência 1 e 2 anos:19 e 7%, respectivamente.Resultados positivos apesar de doentes maioritáriamente quimioresistentes ou quimiorefractários(>70% e estadio IV(>80%. Conclui-se que a administração de docetaxel em doentes com CPNPC e SP70% pts were refractory to 1st-line CT and >80% were in stage IV.We conclude that for NSCLC pts with PS<2, docetaxel as a 2nd-line-CT is a worthwile treatment with acceptable toxicity that significantly prolongs survival. Palavras-chave: CPNPC, docetaxel, Key-words: NSCLC, docetaxel

Reacções adversas aos antibacilares em doentes internados: Gravidade e factores de risco

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Ana Sofia Vilariça

2010-05-01

édia do grupo de doentes com RA foi de 58,4 dias. Esta demora média apresentou diferenças estatisticamente significativas (p< 0,001 em relação à demora média dos doentes sem RA, que foi de 26 dias. Os fármacos mais implicados foram a isoniazida (62,2% e a rifampicina (51,9%. Dos 134 casos em que foi possível caracterizar a gravidade das RA, em 106 casos (79% houve necessidade de suspensão do fármaco. A relação causal fármaco-RA foi definitiva em 23 casos (17%. Dos 13 doentes (9,6% que faleceram, em 6 (4,4% a RA esteve directamente implicada na causa de morte.A ocorrência de qualquer RA foi associada ao alcoolismo (risco relativo [RR] de 3,0; 95% de intervalo confiança [IC], 1,1-7,9 e aos níveis de CD4 < 350 células/mm 3 ([RR] de 2,6; [IC], 1,4-5.No modelo preditivo, as reacções hepáticas foram associadas à ocorrência de hepatites virais B e/ou C ([RR] de 2,5; [IC], 1,2-5,1 e aos níveis de CD4 < 350 células/mm3 ([RR] de 5,5; [IC], 1,6-18,6.Conclusões: Os antibacilares estão associados a um número significativo de RA que podem condicionar grande morbilidade, prolongamento do internamento e mesmo alguma mortalidade. Os nossos resultados mostram que o alcoolismo e os níveis de CD4 <350 células/mm3 foram significativamente associados a um elevado risco de ocorrência de qualquer RA e que as hepatites B e C e os níveis de CD4 < 350 células/mm3 foram associados, também de forma significativa, ao risco de RA hepáticas.Rev Port Pneumol 2010; XVI (3: 431-451 Abstract: Introduction: Given Mycobacterium tuberculosis’s characteristics, the treatment of tuberculosis (TB infection is administered over a long period of time (for six months or more with a combination of several drugs which could cause adverse reactions (AR. These can cause significant morbidity and compromise tuberculosis treatment regimens.Aim: To determine the incidence and severity of and risk factors for major

Função pulmonar em doentes obesos submetidos a cirurgia bariátrica

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C. Guimarães

2012-05-01

Full Text Available Resumo: A obesidade é considerada um problema de saúde pública da atualidade. Devido ao facto de alterar a relação entre pulmões, parede torácica e diafragma, a obesidade tem sido relacionada com alterações da função pulmonar. Em Portugal, existem dados muito limitados entre a relação da obesidade com a função pulmonar.O objetivo deste estudo foi avaliar as alterações da função respiratória nos doentes obesos mórbidos e o comportamento dos parâmetros obtidos nas provas funcionais respiratórias (PFR no pré e pós cirurgia bariátrica.Realizamos um estudo retrospectivo pré e pós cirurgia bariátrica em 36 doentes obesos mórbidos, com uma média de idades de 40,6 anos sendo 64% do sexo feminino e com um índice de massa corporal (IMC médio de 49,7 kg/m2. Todos os doentes foram avaliados clínica e funcionalmente antes da cirurgia bariátrica e após estabilização do peso na sequência deste procedimento tendo-se realizado espirometria, volumes pulmonares, difusão do monóxido de carbono (DLCO, pressões máximas respiratórias e gasometria arterial. Previamente à cirurgia a maioria mostrava alterações nas PFR, 34 doentes apresentavam uma diminuição da capacidade residual funcional (CRF dos quais 6 tinham síndrome restritiva. Apenas 2 doentes não expressavam qualquer alteração funcional ou gasométrica. Após a cirurgia bariátrica o IMC médio reduziu para 34 kg/m2 e verificou-se uma melhoria significativa de quase todos os parâmetros funcionais havendo resolução dos padrões restritivos, mantendo, contudo, ainda 13 doentes a CRF diminuída.Foi apenas encontrada correlação com significado estatístico entre a redução do IMC e o aumento da CRF (r = −0,371; p = 0,028.Este estudo sugere uma relação entre obesidade e restrição pulmonar e aponta para um

Freqüência de pólipos em doentes operados de câncer colorretal Frequency of adenomatous polyps after surgical resection of colorectal cancer

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Beatriz Pinho ROCHA

2000-01-01

Full Text Available Introdução - Estudos epidemiológicos e gênicos mostram que os pólipos colônicos do tipo adenoma são lesões pré-neoplásicas. O seguimento de um paciente com câncer colorretal visa principalmente o diagnóstico e retirada de pólipos adenomatosos. Objetivo - Estudar a freqüência do aparecimento de pólipos adenomatosos em doentes com câncer colorretal em acompanhamento clínico após ressecção tumoral. Casuística e Métodos - Foi estudada, retrospectivamente, a freqüência de pólipos do tipo adenoma em 68 pacientes com idade média de 59 anos, submetidos a cirurgia curativa para tratamento de câncer colorretal e a colonoscopia de controle. Resultados - A incidência de pólipos adenomatosos foi de 18%, sendo maior acima de 45 anos (20% e no cólon esquerdo (38%. Em relação ao tipo histológico, 61% eram tubulares, 22% vilosos e 17% túbulo-vilosos. Discussão - Assim como em outros relatos da literatura, a incidência de pólipos foi superior em indivíduos com mais de 45 anos, sendo em mais da metade do tipo tubular. A freqüência de pólipos foi maior nos dois primeiros anos de acompanhamento.Introduction - Epidemiologic and molecular biologic studies have already demonstrated that adenomatous colonic polyps are precancerous diseases. The main indication of the colonoscopy in the surveillance of colorectal cancer treated patients is the diagnosis and resection of adenomatous polyps. Aim - To study the frequency of adenomatous polyps after surgically resection of colorectal cancer. Material and Methods - Sixty eight patients, mean age 59 years old, with total resection of colorectal cancer, submitted to various colonoscopies during the follow up were studied retrospectively. The histological type and the characteristics of the polyp were described. Results - The frequency of polyps was 18%, being higher in the patients with more than 45 years (20%. The site of the polyps was in the left colon in 38% of the patients with

Prevalência de insónia de novo em doentes com síndrome de apneia obstrutiva do sono tratados com suporte ventilatório nocturno

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P. Caetano Mota

2012-01-01

Full Text Available Resumo: Introdução: A insónia de novo (IN associada ao uso do suporte ventilatório nocturno (SVN tem sido uma realidade constatada na prática clínica, contudo é de salientar a escassez de dados referentes à sua prevalência. O nosso objectivo consistiu em determinar a prevalência de IN e seus factores de risco em doentes com síndrome de apneia obstrutiva do sono (SAOS sob SVN. Material e métodos: Estudo descritivo transversal que incluiu 80 doentes com SAOS sob SVN. Efectuada comparação entre dois grupos, com e sem IN, relativamente a características demográficas, relacionadas com a doença, e personalidade. Foram excluídos os doentes sob medicação ansiolítica e/ou antidepressiva, com perda ponderal superior ou igual a 10%, e com sintomas da síndrome das pernas inquietas. Resultados: A mediana de idades dos doentes incluídos foi de 60,0 (intervalo interquartil (IIQ 10,0 anos; 82,5% eram do sexo masculino. Os valores iniciais medianos da escala de sonolência de Epworth (ESE e do índice de apneia-hipopneia (IAH foram de 12,5 (IIQ 9,0 e de 44,1 (IIQ 22,4/h, respectivamente. A maioria dos doentes (91,3% estava sob pressão positiva nas vias aéreas em modo automático (auto-adjusting positive airway pressure (APAP. A insónia prévia ao uso de SVN estava presente em 30% (n = 24 dos doentes. A prevalência de IN foi de 21,4% (12/56 e os subtipos de insónia inicial e/ou intermédia foram os mais frequentes (n = 11. Foi encontrada uma relação negativa estatisticamente significativa entre a IN e a pressão em 90% do tempo de SVN (P90 (p = 0.040. Conclusões: Os doentes com SAOS sob SVN apresentaram uma prevalência elevada de IN. Os doentes com IN apresentaram níveis inferiores de pressão de SVN comparativamente com os outros. Abstract: Introduction: New-onset insomnia (NOI associated with nocturnal ventilatory support (NVS is

A família do p53: aspectos estruturais e funcionais do p73 e do p63 The p53 family: structural and functional aspects of p73 and p63

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Alfredo Ribeiro-Silva

2003-06-01

Full Text Available O p53 é um gene regulador chave do ciclo celular que, quando sofre mutações, leva ao desenvolvimento de neoplasias, atuando, portanto, como um gene supressor tumoral em condições normais. Recentemente foram identificados genes homólogos ao p53 denominados p73 e p63, provavelmente oriundos de um gene ancestral comum. Apesar da grande homologia estrutural, os membros da família do p53 possuem diferenças funcionais entre si. O presente artigo tem por finalidade discorrer sobre os principais aspectos estruturais e funcionais do p73 e do p63, ressaltando seus papéis na tumorigênese humana. O p73 ativa vários genes responsivos ao p53 e, quando superexpresso, inibe a ação do p53. Raramente encontra-se mutado em neoplasias, e seu papel na tumorigênese humana ainda é motivo de controvérsias. O p63 não é um gene supressor tumoral clássico, sendo essencial para a manutenção de uma população de células precursoras (células-tronco em vários tecidos epiteliais. O p63 marca as células basais de vários órgãos epiteliais, como a pele e a próstata, podendo ser considerado um marcador de indiferenciação celular. O p63 é um marcador recentemente descrito e ainda requer maior investigação para determinar seu papel no desenvolvimento de neoplasias em humanos.The p53 gene has a key role in the cell cycle control. When mutated, it promotes the development of neoplasms, acting in so far as a tumor suppressor gene in normal conditions. Recently, genes homologue to p53 were identified, named p73 e p63, probably originated from a common ancestral gene. Despite the great structural homology, the members of p53 family have functional differences. This article aims to discourse about the major structural and functional aspects of p73 and p63, reinforcing their role in human tumorigenesis. P73 activates several p53 responsive genes and, when overexpressed, inhibits the p53 action. It is rarely mutated in neoplasms and its role in human

Impacto do tratamento do cancro colorrectal no doente e cônjuge : implicações na qualidade de vida, morbilidade psicológica, representações de doenças e stress pós-traumático

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Figueiredo, Ana Paula Rodrigues da Silva

2007-01-01

Dissertação de mestrado em Educação - Área de Especialização em Educação para a Saúde O presente trabalho, com o título “Impacto do tratamento no doente com cancro colorrectal e cônjuge: Qualidade de vida, representações da doença, satisfação marital, morbilidade psicológica e stress pós-traumático”, tem como objectivo avaliar o impacto do tratamento de cirurgia, cirurgia/quimioterapia e cirurgia/radioterapia no doente com cancro colorrectal e no respectivo conjugue nas várias dimensões ps...

Reacções adversas aos antibacilares em doentes internados: Gravidade e factores de risco

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Ana Sofia Vilariça

2010-05-01

média do grupo de doentes com RA foi de 58,4 dias. Esta demora média apresentou diferenças estatisticamente significativas (p < 0,001 em relação à demora média dos doentes sem RA, que foi de 26 dias. Os fármacos mais implicados foram a isoniazida (62,2% e a rifampicina (51,9%. Dos 134 casos em que foi possível caracterizar a gravidade das RA, em 106 casos (79% houve necessidade de suspensão do fármaco. A relação causal fármaco-RA foi definitiva em 23 casos (17%. Dos 13 doentes (9,6% que faleceram, em 6 (4,4% a RA esteve directamente implicada na causa de morte. A ocorrência de qualquer RA foi associada ao alcoolismo (risco relativo [RR] de 3,0; 95% de intervalo confiança [IC], 1,1–7,9 e aos níveis de CD4 < 350 células/ mm3 ([RR] de 2,6 ; [IC], 1,4–5. No modelo preditivo, as reacções hepáticas foram associadas à ocorrência de hepatites virais B e/ou C ([RR] de 2,5; [IC], 1,2–5,1 e aos níveis de CD4 < 350 células/mm3 ([RR] de 5,5; [IC], 1,6–18,6. Conclusões: Os antibacilares estão associados a um número significativo de RA que podem condicionar grande morbilidade, prolongamento do internamento e mesmo alguma mortalidade. Os nossos resultados mostram que o alcoolismo e os níveis de CD4 <350 células/mm3 foram significativamente associados a um elevado risco de ocorrência de qualquer RA e que as hepatites B e C e os níveis de CD4 < 350 células/mm3 foram associados, também de forma significativa, ao risco de RA hepáticas. Abstract: Introduction: Given Mycobacterium tuberculosis's characteristics, the treatment of tuberculosis (TB infection is administered over a long period of time (for six months or more with a combination of several drugs which could cause adverse reactions (AR. These can cause significant morbidity and compromise tuberculosis treatment regimens. Aim: To determine the incidence and severity of and risk factors for major

Osteonecrose da mandíbula associada aos bifosfonatos em doentes com cancro do pulmão

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Inês Neves

2013-09-01

Full Text Available Resumo: A osteonecrose da mandíbula (ONM pode surgir como complicação do tratamento com bifosfonatos. Esta patologia tem sido descrita em doentes com cancro e o seu desenvolvimento associado a exposição prolongada a altas doses de bifosfonatos. Má higiene dentária, história de uso de próteses ou extração dentária, quimioterapia, corticosteroides e radioterapia da cabeça e pescoço são fatores de risco reportados. Nas fases iniciais pode ser assintomática, contudo, o doente posteriormente desenvolve dor significativa e exposição óssea progressiva. Os autores descrevem 3 casos de ONM em doentes com cancro do pulmão após exposição prolongada a bifosfonatos e na presença de fatores de risco conhecidos. A ONM pode atingir seriamente a qualidade de vida dos doentes com cancro. O diagnóstico precoce poderá reduzir ou mesmo evitar as consequências da lesão óssea progressiva. Abstract: Osteonecrosis of the jaw (ONJ can occur as a complication of bisphosphonate therapy. This condition has been described in cancer patients and its development has been associated with prolonged exposure to high doses of bisphosphonates. Bad dental hygiene, a history of prosthesis or dental extraction, chemotherapy, corticosteroids, and radiation therapy of the head and neck are risk factors reported. In the initial stages it may be asymptomatic, but the patient subsequently develops severe pain and progressive exposed bone. The authors describe three cases of ONJ in lung cancer patients after prolonged exposure to bisphosphonates and there were known risk factors. ONJ can seriously affect the quality of life of cancer patients. An early diagnosis may reduce or avoid the consequences of progressive bone lesion. Palavras-chave: Osteonecrose da mandíbula associada aos bifosfonatos, Cancro do pulmão, Fatores de risco, Tratamento, Keywords: Bisphosphonate-associated osteonecrosis of the

Controlo intensivo da glicémia em doentes críticos

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Ferreira, AR

2007-01-01

Trabalho realizado no contexto do estágio de Cuidados Intensivos do Internato Médico Complementar A evolução da medicina intensiva durante as últimas três a quatro décadas trouxe um aumento tremendo na sobrevivência imediata dos doentes críticos, com patologias previamente letais. É por isso frequente na actualidade que os doentes entrem numa fase crónica de doença crítica, durante a qual permanecem dependentes do suporte de orgãos vitais por um ...

Resultados do tratamento do carcinoma espinocelular anal e do seu precursor em doentes HIV-positivos Outcome of treatment of anal squamous cell carcinoma and its precursor in HIV-infected patients

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Sidney Roberto Nadal

2007-08-01

Full Text Available OBJETIVO: A incidência de carcinomas espinocelulares anais vem aumentando nos doentes HIV-positivos. O tratamento consiste de radio e/ou quimioterapia, eventualmente seguidos pela ressecção do tumor. O objetivo é avaliar o seguimento desses doentes para verificar as recidivas e a evolução do NIAA para câncer. Apresentação da casuística da Equipe Técnica de Proctologia do Instituto de Infectologia Emílio Ribas, de São Paulo. MÉTODOS: Acompanhamos 45 doentes HIV-positivos portadores de carcinoma espinocelular anal e seu precursor no período de 1996 a 2006. Eram 30 neoplasias intra-epiteliais anais de alto grau (NIAA, tratadas com ressecção local e 15 carcinomas invasores do canal anal. Nove das 15 lesões invasivas foram submetidas ao esquema de Nigro isolado ou associado à ressecção local, amputação abdominoperineal ou colostomia para derivação. RESULTADOS: No seguimento ambulatorial das NIAA tivemos recidiva em 16,7% e não observamos evolução para carcinoma, num período mínimo de três anos. Entre os nove tumores submetidos ao esquema de Nigro, com ou sem operação complementar, cinco estão livres de tumor. Nenhum tratamento foi feito em cinco doentes. Em três, devido às péssimas condições clínicas, e em dois, pois recusaram tratamento. Outro teve diagnóstico na vigência de oclusão intestinal sendo submetido à colostomia de derivação. CONCLUSÃO: Concluímos que a NIAA pode reincidir após excisão local em doentes HIV-positivos, mas não evolui para carcinoma invasor e que os doentes de câncer anal invasor podem ser tratados da mesma maneira que a população soronegativa para o HIV desde que as condições clínicas o permitam.OBJECTIVE: Incidence of anal squamous cell carcinoma is increasing mainly among HIV-positive patients. Treatment consists of radiotherapy and chemotherapy, sometimes followed by tumor resection. The objective was to evaluate the follow-up of such patients to verify recurrences

PCNA and p53 expression in oral leukoplakia with different degrees of keratinization Expressão do PCNA e p53 em leucoplasias de mucosa jugal com diferentes graus de queratinização

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Melaine de Almeida Lawall

2006-08-01

Full Text Available Leukoplakias are oral lesions that may have many clinical and histological aspects and they are usually associated with malignancy when dysplastic alterations are shown. However, these transformations may occur in non-dysplastic lesions that show harmless clinical aspect. For this reason, the proposal was to study the p53 and PCNA immunohistochemical expression in non-dysplastic leukoplakias, trying to correlate the results only with the epithelial keratinization degree. For this, 24 leukoplakias degrees I, II and III of Grinspan were used, all of them located in oral mucosa. Most of the leukoplakias showed p53 and PCNA expression in their different keratinization degrees. The p53 marking was confined to the basal and parabasal layers, while the PCNA marking occurred in practically all epithelial layers. The expression pattern of these markers was histologically and statistically similar between the lesions with these keratinization variations. It was evident that non-dysplastic epithelium of leukoplakias showed submicroscopical signs of alterations that lead to malignant transformation, and that the keratinization degree did not correlate to a greater risk of this event.As leucoplasias são lesões orais que podem apresentar vários aspectos clínicos e histológicos e são associadas à malignidade geralmente quando apresentam alterações displásicas. Contudo, essas transformações podem ocorrer em lesões sem displasia que apresentam aspecto clínico inocente. Por esse motivo nossa proposta foi estudar a expressão imuno-histoquímica do p53 e PCNA em leucoplasias sem displasias, buscando correlacionar os resultados apenas com o grau de queratinização epitelial. Para isso foram utilizadas as leucoplasias Grau I, II e III de Grinspan, num total de 24 lesões, todas localizadas em mucosa jugal. A maior parte das leucoplasias, em seus diferentes graus de queratinização, apresentou expressão de p53 e PCNA. A marcação do p53 restringiu

Avaliação da expressão do gene MGMT nos tecidos normal e neoplásico de doentes com câncer colorretal

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Adriana Teixeira Cordeiro

Full Text Available OBJETIVO: Avaliar a expressão tecidual do gene de reparo MGMT comparando a mucosa cólica normal e neoplásica em doentes com câncer colorretal. MÉTODOS: Foram estudados 44 portadores de adenocarcinoma colorretal confirmado por estudo histopatológico. Foram excluídos doentes suspeitos de pertencerem a famílias com câncer colorretal hereditário (HNPCC e PAF e os portadores de câncer do reto médio e inferior submetidos a tratamento quimioradioterápico neoadjuvante. A expressão do gene MGMT foi avaliada pela técnica da reação de polimerase em cadeia em tempo real (RT-PCR. A comparação dos resultados encontrados para expressão do gene MGMT entre tecidos normais e neoplásicos foi feita pelo teste t de Student pareado, adotando-se nível de significância de 5% (p <0,05. RESULTADOS: A expressão tecidual do gene MGMT em todos os doentes foi menor no tecido neoplásico quando comparada a do tecido normal (p=0,002. CONCLUSÃO: O gene de reparo MGMT encontra-se menos expresso no tecido neoplásico quando comparados aos tecidos normais em portadores de CCR esporádico.

Valor Diagnóstico do Aumento dos Eosinóftlos e Linfocitos no Lavado Bronco-Alveolar em Doentes com Insuficiência Respiratória Aguda e Infiltrados Pulmonares Difusos

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Kazui Soma; Nobukazu Takada; Masaru Kubota; Masato Katagiri; Nobuo Yanase; Tomoyuki Tomita; Takashj Ohwada

2000-01-01

RESUMO: Os autores analisaram de 1983 a 199 1, a utilidade da contagem diferencial de células no Lavado Bronco-Alveolar (LBA) em doentes com Insuficiência Respiratória Aguda (IRA) e Infiltrados Pulmonares Difusos (IPD), com particular interesse nos que apresentavam níveis elevados de eosinóflos ou de linfocitos no LBA. Foram estudados 118 doentes com insuficiência respiratória para aguda e com PaO2

P53 and Rb tumor suppressor gene alterations in gastric cancer Alterações dos genes supressores tumorais p53 e Rb no câncer gástrico

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Rejane Mattar

2004-01-01

Full Text Available Inactivation of tumor suppressor genes has been frequently observed in gastric carcinogenesis. Our purpose was to study the involvement of p53, APC, DCC, and Rb genes in gastric carcinoma. METHOD: Loss of heterozygosity of the p53, APC, DCC and Rb genes was studied in 22 gastric cancer tissues using polymerase chain reaction; single-strand conformation polymorphism of the p53 gene exons 5-6 and exons 7-8 was studied using 35S-dATP, and p53 expression was detected using a histological immunoperoxidase method with an anti-p53 clone. RESULTS AND DISCUSSION: No loss of heterozygosity was observed in any of these tumor suppressor genes; homozygous deletion was detected in the Rb gene in 23% (3/13 of the cases of intestinal-type gastric carcinoma. Eighteen (81.8% cases showed band mobility shifts in exons 5-6 and/or 7-8 of the p53 gene. The presence of the p53 protein was positive in gastric cancer cells in 14 cases (63.6%. Normal gastric mucosa showed negative staining for p53; thus, the immunoreactivity was likely to represent mutant forms. The correlation of band mobility shift and the immunoreactivity to anti-p53 was not significant (P = .90. There was no correlation of gene alterations with the disease severity. CONCLUSIONS: The inactivation of Rb and p53 genes is involved in gastric carcinogenesis in our environment. Loss of the Rb gene observed only in the intestinal-type gastric cancer should be further evaluated in association with Helicobacter pylori infection. The p53 gene was affected in both intestinal and diffuse histological types of gastric cancer.A inativação de genes supressores tumorais tem sido freqüentemente observada na carcinogênese gástrica. O nosso objetivo foi estudar o envolvimento dos genes p53, APC, DCC e Rb no câncer gástrico. MÉTODO: Vinte e dois casos de câncer gástrico foram estudados por PCR-LOH (reação de polimerase em cadeia- perda de alelo heterozigoto dos genes p53, APC, DCC e Rb; e por PCR-SSCP (rea

Fisiopatologia da Dispneia em doentes cardíacos com Congestão Pulmonar** Trabalbo vencedor ex-aqueo do Prémio Thomé Villar/Boehringer Ingelheim, 1995

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Miguel Mota Carmo

1997-03-01

Full Text Available SUMÁRIO: O objectivo deste estudo foi avaliar a importância da comparticipação das alterações do controlo da ventilaçõe da força dos músculos respiratórios na génese da dispneia em doentes cardíacos com estase pulmonar. Para isso comparámos 48 doentes (GI, com uma idade média de 61 anos e uma pressão capilar pulmonar (PCP de 19,9 mmHg, com um grupo de 35 controlos (GII, com uma idade média de 62 anos. Foram efectuadas as seguintes avaliações: volumes e capacidades pulmonares pelo método de diluição do hétio e por pneumotacografia, pressão de oclusão e resposta ventilatória em hipercánia, bem como a quantificação simultânea da dispneia utilizando uma escala visual analógica. Foram também medidas as pressões máximas dos músculos respiratórios, ao nível da boca, em repouso. Os doentes cardíacos foram submetidos a cateterismo cardíaco direito com determinação do débito cardíaco por termodilui determinação. Nestes doentes encontrou-se um aumento da pressão de oclusão basal em comparação com o grupo controlo (P0,1 GI-1,7 cmH20 / GII -1,35 cmH20; p<0,001, provavelmente devido ao padrão espirométrico restritivo que apresentavam. Não se detectaram alterações na variação da P0,1 durante a prova de hiperclápnia pelo que admitimos que o controlo central da ventilação se encontrava integro. Durante esta prova e para um mesmo aumento da ventilação, os doentes cardiacos apresentaram um maior grau de dispneia. A redução das pressões máximas respiratórias, bem como o aumento da “drive” respiratória em repouso, poderão estar implicadas na génese da dispneia oeste grupo de doentes. ABSTRACT: The purpose of this study was to evaluate whether pulmonary congestion (PC in cardiac patients may induce changes in the control of breathing or in the

Respostas das citocinas T 2 desencadeadas por Mycobacterium tuberculosis virulento nos doentes com tuberculose pulmonar em estado avançado

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Diane J. Ordway

2001-03-01

Full Text Available RESUMO: Avaliaram-se in vitro as respostas das citocinas Tipo 1 e Tipo 2 de dadores portugueses saudáveis vacinados à nascença com BCG, com Mantoux positivo (induração≥5 mm e de doentes com tuberculose pulmonar (TP. Foi efectuado o estudo por ELISA da produção de IFN-γ e IL-5 por Células Mononucleares do Sangue Periférico (CMSP dos dadores após estimulação com M. tuberculosis e antigénio solúvel PPD. Foi confirmada a presença intracelular de IFN-γ e de IL-4 em subpopulações de células T por análise multiparamétrica, em citometria de fluxo. As CMSP dos doentes com tuberculose estimuladas com PPD e M. tuberculosis demonstraram uma diminuição na produção de IFN-γ sem aumento da produção de IL-5 em resposta ao painel de antigénios. Nos doentes com tuberculose observou-se uma frequência diminuída de IFN-γ intracelular nas células T CD4+ e CD8+, em comparação com os grupos controlos. Após estimulação das CMSP com M. tuberculosis, os doentes demonstraram um aumento médio de IL-4 intracelular no fenótipo T CD4+, mais evidente na subpopulação T CD8+. O aumento da secreção de IL-4 nos doentes com tuberculose verificou-se sobretudo nos indivíduos em estado avançado da doença. Os resultados obtidos por Citometria de Fluxo contradizem de alguma forma os obtidos por ELISA. A secreção de IL-4 intracelular representa uma medida mais sensível da produção de citocinas tipo 2 do que a quantificação de IL-5 por técnicas de ELISA. Estes novos resultados sugerem que pode ocorrer uma mudança de T 1 para T 2 em doentes com tuberculose em estado avançado.REV PORT PNEUMOL 2001; VII (2: ABSTRACT: In vitro Type 1 and Type 2 cytokine responses were assessed in healthy Portuguese donors who were BGC vaccinated at birth and Mantoux positive (induration 5≥mm and pulmonary tuberculosis patients

Medicina Centrada no Doente

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Cláudia Silveira

2017-09-01

Full Text Available A Gazeta Médica está em movimento ascendente, com dinamismo e capacidade de atração de artigos originais, revisões e casos clínicos de grande qualidade. A presença de trabalhos que demonstram a importância de cuidados de saúde baseados na entrega de valor são predominantes, onde a capacidade de diagnóstico e tratamento de patologias cada vez mais complexas e as necessidades de cada doente se encontram no centro do exercício da medicina. O sexto número da Gazeta Médica revela um conjunto de trabalhos desenvolvidos de forma integrada por equipas multidisciplinares, da relevância da discussão de casos clínicos e da organização dos cuidados de saúde orientados à doença e ao doente. O artigo “Abordagem sistémica de tolerância ao exercício: um caso para modelação matemática” apresenta um modelo matemático adaptado e desenvolvido pelos autores para a prescrição de exercício físico, dada a importância de antecipar a tolerância ao esforço físico de cada indivíduo. O artigo conclui com a oportunidade existente na criação de um núcleo de investigação em medicina desportiva com inclusão da modelação matemática em sistemas dinâmicos. O Instituto CUF de Oncologia apresenta dois artigos originais, o primeiro sobre os primeiros casos tratados em Portugal em recidivas locorregionais com recurso à radioterapia e hipertermia, e o segundo com uma síntese da casuística tratada na unidade de Oncologia pulmonar do Hospital CUF Porto entre 2014 e 2016 e a comparação com o seu referencial nacional. São ainda apresentados casos clínicos diversos onde é evidente a importância do trabalho multidisciplinar e em equipa na obtenção de melhores outcomes clínicos. Fecho o editorial com referência ao primeiro artigo de perspetiva sobre os Cuidados Pediátricos em São Tomé e Príncipe que nos transportam para uma prática médica diferente da que experienciamos nos países europeus, onde existem desafios e

Avaliação espirométrica de doentes com sequela de tuberculose submetidos à lobectomia

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Elias Amorim

Full Text Available OBJETIVO: Avaliar a espirometria no pré e pós-operatório de doentes com sequela de tuberculose, submetidos à lobectomia. MÉTODOS: Foram selecionados 20 doentes, com idade entre 15 e 56 anos, de ambos os sexos, com história pregressa de tratamento de tuberculose, apresentando infecção de repetição ou hemoptises. Foram submetidos à lobectomia pulmonar. O tempo de tratamento da tuberculose foi seis meses e o aparecimento dos sintomas entre um e 32 anos. Foram avaliadas a capacidade vital (CV, a capacidade vital forçada (CVF, o volume expiratório forçado (VEF1, o VEF1/CVF, o fluxo expiratório forçado (FEF e o pico de fluxo expiratório (PFE após o primeiro, terceiro e sexto meses em relação ao pré-operatório. O nível de significância (á aplicado em todos os testes foi 5%, ou seja, considerou-se significativo quando p<0,05. RESULTADOS: As Médias encontradas foram as seguintes: Capacidade Vital (CV Pré-operatória-2,83 ; 1º PO 2,12; 3º PO 2,31; 6º PO 2,43. Capacidade Vital Forçada (CVF Pré-operatória- 2,97; 1º PO 2,21; 3º PO 2,35; 6º PO 2,53. Volume Expiratório no 1º Segundo (VEF1 Pré-operatório 2,23; 1º PO 1,75; 3º PO 1,81; 6º PO 1,97. Houve diminuição acentuada das funções respiratórias no primeiro mês de pós-operatório, porém houve melhora dos parâmetros a partir do terceiro mês, com progressivo aumento até o sexto mês de pós-operatório. CONCLUSÃO: Não houve recuperação dos parâmetros espirométricos, comparados aos do pré operatório, após seis meses de pós-operatório nos pacientes com sequela de tuberculose submetidos à lobectomia.

Heterotopia pancreática: análise clínico-patológica de 18 doentes

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Sansom Henrique Bromberg

Full Text Available OBJETIVO: Analisar as características clínico-patológicas do tecido pancreático heterotópico em órgãos digestivos abdominais. MÉTODOS: Realizamos estudo retrospectivo analisando 18 portadores de pâncreas heterotópico diagnosticados histologicamente. Seus dados clínicos e histopatológicos foram revistos. O tecido pancreático heterotópico foi classificado em três modelos histológicos: tipo I constituído por três componentes do pâncreas normal (ácinos, ductos e ilhotas, tipo II com dois componentes e tipo três com somente um componente. RESULTADOS: A média de idade foi de 52,7 anos, variando de 34 a 73 anos, com nove homens e nove mulheres. Sintomas foram observados em somente quatro doentes, sendo suas lesôes diagnosticadas por gastroscopia. Os 14 restantes eram assintomáticos e suas anomalias descobertas acidentalmente. A maioria das lesões situava-se no trato superior: sete (38,9% no estômago, seis (33,3% no duodeno e três (16,6% no jejuno. A heterotopia localizou-se preferencialmente na submucosa (83,3%, mas também foi observada na muscular própria e na sub-serosa. Em sete (38,9% espécimes todos os componentes pancreáticos foram constatados (tipo I, em oito (44,4% estavam presentes glândulas exócrinas e ductos excretores (tipo II e em três (16,7% somente o tecido exócrino foi observado (tipo III. CONCLUSÃO: A heterotopia pancreática é rara. Doentes com ectopia pancreática diagnosticadas pelo estudo patológico, assintomáticos ou com sintomas discretos devem permanecer em observação. As lesões detectadas acidentalmente durante procedimentos cirúrgicos necessitam ser removidas por procedimentos conservadores.

Infecção por Rhodococcus em doente imunocompetente - a propósito de um caso

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Susana Barbosa

2015-12-01

Full Text Available Resumo: O Rhodococcus equi raramente causa infecção no humano, sendo que a maioria dos casos descritos estão associados a doentes imunodeprimidos. Os autores apresentam o caso de um homem de 65 anos que foi admitido no serviço de urgência por agravamento da dispneia habitual, tosse e febre. Foi internado com o diagnóstico de sépsis com ponto de partida respiratório em pneumonia de focos múltiplos e peritonite. Medicado empiricamente com ceftriaxone, com melhoria clínica. Isolamento no líquido ascítico de Rhodococcus spp. Cumpriu 2 meses de antibioterapia com doxiciclina, com boa evolução clínica, analítica e radiológica. Os autores apresentam este caso dada a raridade da situação e pretendem realçar a necessidade de um elevado índice de suspeição para o diagnóstico da infecção por este agente em doentes imunocompetentes. Abstract: Rhodococcus equi rarely causes human infection, and most of the described cases are associated with immunosuppressed patients. The authors present a 65-year-old man who was admitted to the emergency department with worsening of dyspnoea, cough and fever. He was admitted with a diagnosis of sepsis with respiratory starting point in multiple foci pneumonia and peritonitis. He was medicated empirically with ceftriaxone, with clinical improvement. Isolation in the ascites fluid of Rhodococcus spp. He completed two months of antibiotic treatment with doxycycline, with clinical, analytical and radiological improvement. The authors present this case due to the rarity of the situation and highlight the need for a high index of suspicion for the infection diagnosis by this agent in immunocompetent patients.

O critério de positividade para a análise imunoistoquímica da p53 na confirmação da displasia do esôfago de Barrett faz diferença? Does positive criterium for p53 immunohistochemical analysis in the confirmation of Barrett's dysplasia make difference?

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César Vivian Lopes

2005-12-01

Full Text Available RACIONAL: O esôfago de Barrett é uma complicação da doença do refluxo gastroesofágico com importante potencial de malignização. Relata-se que a expressão do marcador tumoral p53 se acentua com a progressão displasia-adenocarcinoma. OBJETIVO: Avaliar a expressão da p53 no epitélio de Barrett com presença ou não de displasia conforme dois critérios de positividade. MATERIAL E MÉTODOS: O material foi constituído por biopsias endoscópicas de 42 doentes com esôfago de Barrett. Cortes histológicos foram corados pela hematoxilina-eosina, pelo PAS-alcian blue e avaliados quanto à expressão imunoistoquímica da p53. O diagnóstico de displasia foi firmado pela concordância entre três patologistas. Foram utilizados dois critérios de positividade para a p53: 1. a coloração de, pelo menos, metade dos núcleos e 2. o encontro de qualquer núcleo corado. RESULTADOS: O número total de fragmentos foi de 229, com média de 5,4 por paciente. A displasia foi detectada em seis (14,3% casos. Para diferentes critérios de positividade, a p53 foi detectada, respectivamente, em 5 (13,9% e 14 (38,9% com epitélio metaplásico não-displásico. Especificamente nos seis casos displásicos, a p53 foi detectada, conforme o critério de positividade, em um (16,7% e quatro (66,7% casos, respectivamente. CONCLUSÕES: Nesta pequena série, a expressão imunoistoquímica da p53, independente do critério de positividade, não foi de auxílio para a confirmação de alterações displásicas no esôfago de Barrett.BACKGROUND: Barrett's esophagus is the most serious complication of the gastroesophageal reflux disease and presents a malignant potential. The expression of the tumoral marker p53 increases with the dysplasia-adenocarcinoma sequence. AIMS: To evaluate the p53 expression in Barrett's esophagus with or without dysplasia according to the two positive immunostaining criteria. MATERIALS AND METHODS: The material was constituted by endoscopic

Análise comparativa da imunoexpressão da proteína p53 (clones DO-7 e PAb-240 em carcinomas de células escamosas intrabucais e labiais Comparative analysis of p53 protein immunostaining (antibodies DO-7 and PAb-240 in oral cavity and lip squamous cell carcinomas

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José de Assis Silva Júnior

2009-08-01

Full Text Available INTRODUÇÃO: A carcinogênese caracteriza-se como um processo multifatorial, e a inativação da proteína p53 é uma alteração genética comumente observada nos carcinomas de células escamosas de boca (CCEB. OBJETIVO: Analisar e comparar a imunoexpressão da proteína p53, por meio dos clones DO-7 e PAb-240, em CCEB com localização intrabucal e em lábio inferior. MATERIAL E MÉTODOS: Foram selecionados 40 casos de CCEB, sendo 20 de localização intrabucal e 20 em lábio inferior. Foi realizado um estudo imuno-histoquímico utilizando os anticorpos anti-p53 clone DO-7 e PAb-240. A imunoquantificação foi realizada por meio de análise digital de imagem, e os resultados, submetidos a tratamentos estatísticos. RESULTADOS: A imunoexpressão da proteína p53 foi verificada com o anticorpo DO-7 em 13 casos (65% de carcinoma intrabucal e em 19 (95% de carcinoma de lábio inferior. Imunorreatividade para o anticorpo PAb-240 foi observada em 9 casos (45% de lesões intrabucais e em 15 (75% localizados em lábio inferior. Não foram observadas, segundo o teste de Mann-Whitney, diferenças estatisticamente significativas (p > 0,05 na expressão da proteína p53 entre as duas localizações estudadas, independentemente do anticorpo avaliado. Foram identificadas, pelo teste de Wilcoxon, diferenças estatisticamente significativas entre a expressão dos clones DO-7 e PAb-240 em cada um dos grupos analisados (valor p = 0,013 - lábio inferior; valor p = 0,016 - intrabucal. CONCLUSÕES: A expressão da proteína p53 observada nos CCEB, com localizações intrabucais e labiais, sugere a ocorrência de mutações no gene TP53. As diferenças quantitativas obtidas entre os anticorpos estudados, independentemente da localização das lesões, refletem uma especificidade distinta entre os clones DO-7 e PAb-240. O desenvolvimento de mais estudos será fundamental para estabelecer o anticorpo mais adequado para proteína p53 em CCEB

Doentes obesos: complicações respiratórias na unidade pós-anestésica

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J. Mendonça

2014-01-01

Full Text Available Resumo: Introdução: A obesidade tem sido associada a eventos respiratórios e a maioria destes ocorrem no pós-operatório imediato na unidade pós-anestésica (UPA. O objetivo deste estudo foi avaliar o «outcome» e a incidência de eventos adversos respiratórios (ARE pós-operatórios em doentes com obesidade durante a sua permanência na UPA. Métodos: Estudo prospetivo caso-controlo com emparelhamento de 27 pares de adultos com obesidade e doentes com IMC  0,025. A análise multivariada identificou a obesidade e o bloqueio neuromuscular residual como fatores de risco independentes para a ocorrência de eventos respiratórios. A duração da estadia na UPA foi superior nos doentes obesos (120 min vs 84 min, p > 0,01. Conclusões: A incapacidade de respirar profundamente foi o ARE mais frequente no período pós-operatório imediato nos doentes obesos. A obesidade foi considerada um fator de risco independente para ocorrência de ARE na UPA. Os doentes obesos tiveram maior tempo de estadia na UPA mas não tiveram maior tempo de internamento hospitalar. Abstract: Introduction: Obesity has been associated with respiratory complications, and the majority of these complications occur in the Post-Anesthesia Care Unit (PACU. The aim of this study was to evaluate the outcome and incidence of adverse respiratory events (AREs in obese patients during their stay in the PACU Methods: We conducted a prospective control study that included 27 obese patients matched with an equal number of patients with body mass index (BMI < 30 (non-obese control group; the 2 groups of patients were similar in respect to gender distribution, age, and type of surgery and had been admitted into the PACU after elective surgery (May 2011. The AREs were identified during PACU stay. Descriptive analysis of variables was performed, and the Mann-Whitney U test, Chi-square test, or Fisher's exact test

Osteossarcomas humanos de alto grau: imunoexpressão de p53, erb-2 e P-glicoproteína, e correlação com o parâmetro anaplasia P-glycoprotein, erb2 and p53 expression in high-grade human osteosarcomas and their correlation with anaplasia

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Maria Teresa de Seixas Alves

2008-04-01

Full Text Available INTRODUÇÃO: Osteossarcoma (OS, o mais freqüente tumor primário maligno do osso, tem comportamento local agressivo e alto índice de disseminação sistêmica. Os eventos que permitem o crescimento e a disseminação tumoral ainda permanecem controversos. Os estudos sobre a carcinogênese e a progressão dessa neoplasia, com base na imunoexpressão de c-erb-B2, P-glicoproteína (P-gp e p53, apresentam resultados conflitantes acerca do real valor prognóstico e suas correlações com parâmetros histológicos. A anaplasia, em neoplasias na infância, constitui parâmetro histológico de agressividade tumoral e quimiorresistência. Nos OS primários ou metastáticos, seu significado permanece controverso. Por outro lado, em outras neoplasias humanas, a expressão do c-erb-B2 relaciona-se com p53, grau nuclear e outros parâmetros de agressividade. OBJETIVO: Avaliar a imunoexpressão de p53, c-erb-B2 e P-gp em OS, correlacionando os par��metros entre si e com a presença de anaplasia. MÉTODO: O estudo incluiu 96 biópsias pré-quimioterapia de pacientes com OS de alto grau, diagnosticados entre 1991 e 2000. A pesquisa imuno-histoquímica de p53, P-gp e c-erb-B2 foi feita pela técnica da estreptoavidina-biotina-peroxidase. Foram considerados positivos os casos onde havia imunoexpressão em 10% ou mais das células neoplásicas. Somente colorações membranosa (para cerb-B2 e P-gp e nuclear (para p53 foram consideradas positivas. Anaplasia foi definida como no tumor de Wilms, sendo considerada presente ou ausente. RESULTADOS: Anaplasia pôde ser avaliada em 82/96 casos, estando presente em 29 (35,36%. Imunoexpressão de p53 foi detectada em 25 dos 60 casos (36,23%; de P-gp, em 30 dos 73 casos (41,1%; e de c-erb-B2, em 22 dos 55 casos (40%. Os resultados demonstraram associação entre as imunoexpressões de c-erb-B2 e p53 (p = 0,042, p53 e o parâmetro anaplasia (p = 0,015, anaplasia e Pg (p = 0.034 CONCLUSÕES: A imunoexpressão de p53, c

A resposta broncodilatadora em doentes com DPOC (dados do estudo UPLIFT

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D. Tashkin

2008-07-01

Full Text Available Resumo: No início do estudo, foi realizada espirometria antes e depois de 80 μg de ipratrópio e 400 μg de salbutamol, administrados 90 e 30 minutos antes, respectivamente. A administração de dois broncodilatadores e a sua temporalidade teve como objectivo atingir a broncodilatação máxima ou quase máxima. O FEV1 basal após esta broncodilatação, no estudo UPLIFT, permitiu: - examinar a resposta broncodilatadora aguda numa grande coorte de doentes com DPOC moderada a muito grave; - determinar o que pode ser considerado critério de resposta usando vários critérios de reversibilidade; - avaliar as características dos doentes com e sem reversibilidade.

Expressão de p53, p16 E COX-2 em carcinoma escamoso de esôfago e associação histopatológica p53, p16 E COX-2 expression in esophageal squamous cell carcinoma and histopathological association

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Izabella Paz Danezi Felin

2008-12-01

Full Text Available RACIONAL: O câncer de esôfago representa cerca de 2% dos tumores malignos e a terceira causa mais comum de câncer do trato gastrointestinal. A associação do prognóstico do câncer de esôfago com alguns marcadores imunoistoquímicos, como as proteínas p53, p16 e a ciclooxigenase 2 (COX-2 tem sido relatada. A detecção de marcadores moleculares através de imunoistoquímica pode ser utilizada para avaliação prognóstica. OBJETIVOS: Investigar a associação entre a expressão das proteínas p53, p16 e a COX-2 com o estádio do carcinoma escamoso de esôfago. MÉTODOS: Foram analisadas 31 amostras de ressecção cirúrgica por esofagectomia diagnosticadas como carcinoma de células escamosas de esôfago e 31 amostras não-tumorais referentes a cada caso. Realizou-se a revisão histopatológica e o estádio pTNM. Amostras tumorais e não-tumorais adjacentes foram submetidas a análise imunoistoquímica para avaliar o conteúdo das proteínas p53, p16 e COX-2. Foi considerada positiva a expressão nuclear para p53 em quantidade igual ou superior a 10,00% das células e presença da expressão citoplasmática de acordo com três escores (1, 2, 3 de intensidade (leve, moderada, acentuada de imunocoloração para COX-2. RESULTADOS: Em área tumoral, as análises revelaram 48,38% de positividade para p53, 16,12% de positividade para p16, e 100,00% de positividade escores 1+, 2+ ou 3+ para COX-2. No entanto, quando se avaliou possível relação da expressão destes marcadores com o estádio, apenas a COX-2, escore 3+ intensidade acentuada mostraram associação significativa. CONCLUSÃO: O presente estudo demonstrou que existe relação positiva entre a expressão de COX-2, escore 3+ e estádio mais avançado no carcinoma de esôfago.BACKGROUND: The esophageal carcinoma represents about 2% of malignant tumors and is the third most common cause of gastrointestinal cancer. The correlation between immunohistochemistry markers, such as p53, p16

A resposta broncodilatadora em doentes com DPOC (dados do estudo UPLIFT

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D. Tashkin

2008-07-01

Full Text Available Resumo: No início do estudo, foi realizada espirometria antes e depois de 80 μg de ipratrópio e 400 μg de salbutamol, administrados 90 e 30 minutos antes, respectivamente. A administração de dois broncodilatadores e a sua temporalidade teve como objectivo atingir a broncodilatação máxima ou quase máxima. O FEV1 basal após esta broncodilatação, no estudo UPLIFT, permitiu: – examinar a resposta broncodilatadora aguda numa grande coorte de doentes com DPOC moderada a muito grave; – determinar o que pode ser considerado critério de resposta usando vários critérios de reversibilidade; – avaliar as características dos doentes com e sem reversibilidade.

Revisão sistemática do efeito dos broncodilatadores na capacidade para o exercício em doentes com DPOC

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J.J.W. Liesker; P.J. Wijkstra; N.H.T.T. Hacken; G.H. Koëter; D.S. Postma; H.A.M. Kerstjens

2002-01-01

RESUMO: A doença pulmonar obstrutiva crónica (DPOC) constitui um importante problema de saúde pública a nível mundial e a morbilidade e mortalidade associadas a esta doença continuam a aumentar. Sendo uma doença para a qual não existe um tratamento curativo efectivo, tem sido dada ênfase às medidas preventi-vas, da qual se salienta a prevenção tabágica.Pelo facto de as medidas de prevenção tabágica apresentarem uma eficácia em apenas cerca de 20% dos doentes, o tratamento sin...

OTUD5 regulates p53 stability by deubiquitinating p53.

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Judong Luo

Full Text Available The p53 tumour suppressor protein is a transcription factor that prevents oncogenic progression by activating the expression of apoptosis and cell-cycle arrest genes in stressed cells. The stability of p53 is tightly regulated by ubiquitin-dependent degradation, driven mainly by its negative regulators ubiquitin ligase MDM2.In this study, we have identified OTUD5 as a DUB that interacts with and deubiquitinates p53. OTUD5 forms a direct complex with p53 and controls level of ubiquitination. The function of OTUD5 is required to allow the rapid activation of p53-dependent transcription and a p53-dependent apoptosis in response to DNA damage stress.As a novel deubiquitinating enzyme for p53, OTUD5 is required for the stabilization and the activation of a p53 response.

Impacto das comorbilidades num programa de reabilitação respiratória em doentes com doença pulmonar obstrutiva crónica

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A. Carreiro

2013-05-01

Full Text Available Resumo: Introdução: A doença pulmonar obstrutiva crónica (DPOC apresenta um impacto crescente a nível mundial. Devido ao seu impacto sistémico, e porque constitui um importante fator de risco para outras comorbilidades crónicas, a DPOC não pode já ser considerada uma doença com envolvimento exclusivamente pulmonar. Objetivo: Determinar a frequência das comorbilidades em doentes com DPOC que são submetidos a um programa de reabilitação respiratória (PRR e avaliar a influência das suas características basais, bem como das suas comorbilidades nos resultados do PRR. Métodos: O presente estudo incluiu todos os doentes com DPOC que foram admitidos na Unidade de Reabilitação Respiratória para um PRR. A resposta à reabilitação respiratória (RR foi avaliada pela melhoria na tolerância ao exercício (prova de marcha de 6 min, na dispneia (índice de dispneia de Mahler e na qualidade de vida relacionada com a saúde (questionário respiratório de St. George. Resultados: Foram incluídos 114 doentes com DPOC. A maioria dos doentes (96,5% tinha pelo menos uma comorbilidade. As doenças metabólicas (71,1%, as doenças cardiovasculares (67,5%, outras patologias respiratórias (57,9% e a ansiedade/depressão (21,1% foram as mais prevalentes. Apresentaram melhoria na tolerância ao exercício, na qualidade de vida e na dispneia, respetivamente, 64,9, 64,9 e 51,1% dos doentes.A globalidade dos resultados foi semelhante em todos os estadios da DPOC e em todos os subgrupos de comorbilidades. A análise por regressão logística demonstrou que a insuficiência respiratória e a doença coronária influenciaram negativamente a melhoria na qualidade de vida relacionada com a saúde, e que a ansiedade/depressão se relacionou com uma melhoria menos acentuada da dispneia. Conclusão: A RR proporcionou melhoria nos doentes de todos os subgrupos de comorbilidades, salientando o papel fundamental do treino de exercício na reabilitação das

O papel da neutropenia no prognóstico do doente oncológico com pneumonia adquirida na comunidade

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S. Aliberti

2009-07-01

Full Text Available Resumo: A doença infecciosa contribui para uma elevada morbilidade e mortalidade no doente oncológico, representando a pneumonia adquirida na comunidade a mais frequente.O desenvolvimento de PAC no doente neoplásico parece advir da modificação de mecanismos de defesa imunitária resultante, quer da patologia maligna, quer do tratamento oncológico. O risco de infecção relacionada com o tipo de neoplasia pode associar-se ao défice de imunidade humoral, celular ou do número de neutrófilos. As doenças hematológicas malignas podem predispor o doente às infecções devido à substituição da medula por células neoplásicas. Consequentemente, estes doentes têm neutropenia funcional, apesar de apresentarem, muitas vezes, um número normal ou aumentado de neutrófilos. Por outro lado, estes doentes podem ter neutropenia como efeito secundário da quimioterapia e/ou radioterapia (neutropenia absoluta.A gravidade da neutropenia foi considerada como principal factor de risco isolado no doente neoplásico, com particular relevância se o número de neutrófilos ≤500cel/mm3.A mortalidade global atribuída à neutropenia febril no doente neoplásico é de 30–50%. Nas últimas décadas, o tratamento das infecções na população oncológica foi direccionado, primariamente, para o manuseamento da neutropenia febril, devido ao facto de o local da infecção não ser determinado em 50–80% dos casos.As guidelines da American Thoracic Society de 2001 utilizavam a neutropenia para identificar os quadros mais graves de PAC nos doentes oncológicos. Os doen tes com patologia hematológica e neutropenia funcional ou indivíduos com qualquer tipo de neoplasia e neutropenia absoluta foram excluídos das referidas guidelines. A decisão de incluir doentes com tumores sólidos não neutropénicos foi baseada, apenas, na opinião de

Desnutrição e Qualidade de Vida em Doentes com Cancro do Pulmão Não Pequenas Células

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S. Xará

2011-07-01

Full Text Available Resumo: O cancro está associado a uma deterioração do estado nutricional e da qualidade de vida (QdV, mas não se conhece a dimensão destas consequências nos doentes com cancro do pulmão não pequenas células (CPNPC. O objectivo deste estudo foi avaliar a associação entre a qualidade de vida e a desnutrição em doentes com CPNPC. O estado nutricional foi avaliado pelo Patient Generated – Subjective Global Assessment e a QdV foi avaliada através do European Organization for Research and Treatment of Cancer Quality of Life – C30 e do módulo específico para doentes com cancro do pulmão. Foi avaliada uma amostra com cinquenta e seis doentes diagnosticados com CPNPC. Uma elevada proporção de doentes encontra-se desnutrida (35,7%, dos quais 1,8% em estadios precoces vs 33,9% em estadios avançados de doença. A desnutrição está associada a dimensões de QdV como a falta de apetite (rho = 0,70, fadiga (rho = 0,54, náuseas e vómitos (rho = 0,52 e também obstipação (rho = 0,56. Os doentes com CPNPC apresentam elevada frequência de desnutrição nos estadios avançados de doença. Os doentes desnutridos apresentam mais sintomatologia e piores estado de saúde global, de funcionamento físico, emocional, social e de desempenho, do que os doentes sem desnutrição. A desnutrição está associada com pior QdV, especificamente nos parâmetros: falta de apetite, náuseas e vómitos, obstipação e fadiga. Abstract: Cancer is related to a deterioration of nutritional status and quality of life (QoL, but the extent of these conditions in patients with Non Small Cell Lung Cancer (NSCLC has not been studied. The aim of the present study was to assess the association between QoL and undernutrition in NSCLC patients. Nutritional status was evaluated with Patient Generated – Subjective Global Assessment and Qo

Fatores preditivos de coledocolitíase em doentes com pancreatite aguda biliar Predictors of choledocholithiasis in patients sustaining acute biliary pancreatitis

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José Gustavo Parreira

2004-12-01

Full Text Available OBJETIVO: Avaliar o papel da fosfatase alcalina (FA, gama glutamiltransferase (gamaGT e ultra-sonografia (US como fatores preditivos de coledocolitíase em doentes com pancreatite aguda biliar (PAB. MÉTODOS: Os dados foram coletados prospectivamente durante um período de 31 meses. Quarenta doentes foram incluídos, sendo 30 mulheres, com média etária de 49 + 16 anos. Foram registrados os dados de todos os doentes com pancreatite aguda biliar. Aqueles doentes ictéricos e com a forma grave da doença foram excluídos. As dosagens de FA e GGT, assim como a US, eram realizadas na admissão e 48 horas antes da cirurgia. Todos os pacientes foram submetidos à colangiografia intra-operatória (CIO ou à colangiografia retrógrada endoscópica (CPRE pré-operatória, que era definida baseada na probabilidade de coledocolitíase. Com o intuito de identificar os indicadores de coledocolitíase, as variáveis foram comparadas entre os pacientes com ou sem coledocolitíase. Os testes t de Student, Qui-quadrado e Fisher foram empregados para a análise estatística, considerando-se pBACKGROUND: To assess the role of alkaline phosphatase (AP, gamil-glutamyltransferase (gammaGT and abdominal ultrasound (US as predictors of choledocholithiasis in patients sustaining acute biliary pancreatitis. METHODS: Data was prospectively collected during a period of 31 months. Forty patients were included, 30 were female and the mean age was 49 + 16. All patients sustaining acute biliary pancreatitis were enrolled. Patients with clinical jaundice and severe pancreatitis were excluded. Serum content of AP and gGT as well as US were assessed at admission and 48 hours before cholecistectomy. All patients underwent intra-operative cholangiography (IOC or pre-operative endoscopic retrograde cholangiography (ERCP, which was indicated based on the odds of choledocholithiasis. In order to identify the predictors of choledocholithiasis, variables were compared between patients

Associação entre a expressão das proteínas p53 e Ki-67 e os achados clínico-patológicos em pacientes com carcinoma invasor do colo uterino Association between p53 and Ki-67 expression and clinicopathologic features in patients with carcinoma of the cervix

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Agnaldo L. Silva-Filho

2005-05-01

Full Text Available OBJETIVO: avaliar a associação da expressão das proteínas p53 e Ki-67 no tumor com achados clínico-patológicos em pacientes com carcinoma invasor de colo uterino. MÉTODOS: foram estudadas amostras de tumor obtidas de 36 pacientes submetidas a histerectomia radical para tratamento de carcinoma invasor do colo uterino estádio IB (FIGO. Amostras do tumor foram fixadas em formol e incluídas em parafina. O material foi analisado pela histopatologia (hematoxilina e eosina e processado para marcação imuno-histoquímica por anticorpos monoclonais contra as proteínas p53 e Ki-67. Os dados foram analisados pelo teste de chi2 para a avaliação das diferenças entre os grupos. RESULTADOS: a idade das pacientes variou de 27 a 73 anos (48,7±10,4 anos. O estadiamento clínico (FIGO foi IB1 em 27 casos (75% e IB2 em 9 casos (25%. A expressão tumoral da proteína p53 foi positiva em metade dos casos. Em relação à expressão do Ki-67, foi evidenciado alto grau de proliferação celular em 73,3% dos casos. Não houve associação da expressão das proteínas p53 e Ki-67 no tumor com idade (p=0,091 e 0,900, estadiamento (p=0,054 e 0,667, tipo histológico (p=0,674 e 0,674, grau de diferenciação (p=0,07 e 0,282, presença de invasão linfovascular (p=0,248 e 0,667, acometimento parametrial (p=0,729 e 0,763 e metástases para os linfonodos pélvicos (p=0,729 e 0,636, respectivamente. CONCLUSÕES: a expressão tumoral das proteínas p53 e Ki-67 não se associou com achados clínico-patológicos em pacientes com carcinoma invasor do colo uterino estádio IB.PURPOSE: to evaluate the association between p53 and Ki-67 expression in the tumor and clinicopathological features in patients with carcinoma of the cervix. METHODS: samples were taken from the tumor of 36 patients with stage IB (FIGO cervical carcinoma submitted to radical hysterectomy. Tissue samples were taken from the tumor, fixed in formalin and embedded in paraffin. The specimens were

Avaliação tardia de doentes gastrectomizados por úlcera péptica: aspectos clínicos, endoscópicos e histopatológicos Late follow-up of gastrectomized patients for peptic ulcer: clinical, endoscopic and histopathological aspects

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João de Souza Coelho-Neto

2005-09-01

Full Text Available RACIONAL: Atualmente são raras as vezes em que é necessária a realização de uma gastrectomia, já que os inibidores da bomba de prótons associados aos esquemas antibióticos usados para erradicar o Helicobacter pylori, mudaram o enfoque do tratamento da úlcera péptica. OBJETIVOS: Avaliar tardiamente os doentes submetidos a gastrectomia parcial no tratamento da úlcera péptica, em época em que o Helicobacter pylori ainda não era erradicado de forma intencional, incluindo os sintomas pós-operatórios em comparação com os pré-operatórios e a incidência de síndromes pós-gastrectomias; avaliação endoscópica, incluindo o tipo de cirurgia realizada e os achados macroscópicos da mucosa do coto gástrico, duodeno ou jejuno, dependendo do tipo de reconstrução; avaliação histopatológica, incluindo a pesquisa da bactéria por dois métodos: histológico e teste de urease; e sua possível associação presente no estômago remanescente com as avaliações clínica, endoscópica e histopatológica pós-operatórias. CASUÍSTICAS E MÉTODOS: Cinqüenta e nove doentes gastrectomizados por úlcera péptica entre os anos de 1985 e 1993 foram avaliados, sendo que 44 (74,6% eram do sexo masculino e tinham idade média de 55 anos, com variação de 31 a 77 anos, passaram por entrevista clínica e por exame endoscópico. O Helicobacter pylori foi pesquisado nas peças cirúrgicas ressecadas, para constatação da sua presença ou não no pré-operatório. RESULTADOS: A avaliação clínica no pós-operatório tardio mostrou que 96% dos doentes apresentaram excelentes e bons resultados (Visick I e II. Os sintomas pós-operatórios mais comuns foram dispepsia leve e outras queixas, como diarréia, anemia e dumping, que ocorreram, respectivamente, em 11 (18,6%, 2 (3,4% e 2 (3,4% casos. A reconstrução tipo Billroth I trouxe melhores resultados clínicos tardios, quando comparada com as reconstruções tipo Billroth II e Y-de-Roux. Na avalia

"Lar, doce Lar": a perspetiva de morrer em casa...

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Costa, Tânia; Souza, Cláudia; Coelho, Patrícia

2012-01-01

O avanço tecnológico contribuiu para generalizar a hospitalização do doente terminal. Contudo, contrariamente ao ambiente hospitalar, o domicílio detém componentes que proporcionam segurança, conforto e esperança no doente. Identificar as necessidades dos doentes/família em cuidados paliativos domiciliários para colmatar as lacunas entre cuidados atuais e desejos dos doentes. Priorizar e orientar a intervenção em cuidados paliativos.

Revisão sistemática do efeito dos broncodilatadores na capacidade para o exercício em doentes com DPOC

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J.J.W. Liesker

2002-03-01

Full Text Available RESUMO: A doença pulmonar obstrutiva crónica (DPOC constitui um importante problema de saúde pública a nível mundial e a morbilidade e mortalidade associadas a esta doença continuam a aumentar. Sendo uma doença para a qual não existe um tratamento curativo efectivo, tem sido dada ênfase às medidas preventi-vas, da qual se salienta a prevenção tabágica.Pelo facto de as medidas de prevenção tabágica apresentarem uma eficácia em apenas cerca de 20% dos doentes, o tratamento sintomático com broncodilatadores tem ocupado o lugar principal no tratamento da DPOC.Um dos principais objectivos da terapêutica com broncodilatadores é reduzir a limitação dos débitos nas vias aéreas e, em consequência, melhorar a dispneia e a tolerância ao exercício físico. Os autores fazem uma revisão sistemática da avaliação dos efeitos da terapêutica com broncodilatadores sobre a dispneia e a capacidade para o exercício.Compararam os efeitos de três grupos de broncodilatadores: anticolinérgicos, β2 agonistas e derivados das xantinas e pesquisaram se o efeito de cada um dos broncodilatadores no exercício com carga incremental era comparável ao efeito sobre o exercício de carga constante.O tipo de exercícios que utiliza cargas crescentes pode ser realizado em cicloergómetro, em tapete ro-lante ou com a prova de shuttle. Os exercícios que utilizam uma carga constante (steady-state incluem a prova de marcha de seis e de doze minutos e o exercício em cicloergómetro.A revisão de 33 estudos realizados em dupla ocultação, aleatorizados e controlados por placebo, escritos na língua inglesa, permitiu verificar que cerca de metade dos estudos revelou um efeito significativo da terapêutica broncodilatadora na capacidade para o exercício.Os agentes anticolinérgicos (brometo de ipratrópio e oxitrópio apresentaram um efeito ben

Expressão imuno-histoquímica dos marcadores pcna, KI67 e p53 em carcinomas epidermóides do trato aerodigestivo superior

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João Paulo Esposito

Full Text Available OBJETIVO: Os carcinomas epidermóides do trato aerodigestivo superior são tumores de comportamento biológico heterogêneo. O objetivo deste trabalho é verificar se a expressão imuno-histoquímica dos marcadores Ki67, PCNA e P53 apresenta correlações com parâmetros prognósticos clínico-patológicos. MÉTODOS: Determinação da expressão imuno-histoquímica dos antígenos Ki67, PCNA e P53 em espécimes tumorais fixados e embebidos em parafina de 53 pacientes com carcinoma epidermóide em diferentes sítios primários do trato aerodigestivo superior. RESULTADOS: Os marcadores tiveram altos índices de expressão imuno-histoquímica, sendo 46,5% para o Ki67, 66,5% para o PCNA e 36,5% para o P53. Não houve correlação da expressão do Ki67 e do PCNA com o estadiamento TNM (AJCC, nem com o grau de malignidade. A expressão do Ki67 apresentou correlação positiva com a expressão do PCNA (p = 0,037. O mesmo aconteceu para o PCNA e o número de mitoses por campo (p = 0,001. CONCLUSÕES: De acordo com estes resultados, concluiu-se que a determinação da imunorreatividade dos marcadores Ki67 e PCNA é um método objetivo e quantificável para avaliar proliferação celular que pode subsidiar as informações prognósticas.

Paracoccidioidomicose subaguda progressiva: tratamento de um doente com anfotericina B e nutrição parenteral

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Paulo Camara Marques Pereira

1985-10-01

Full Text Available Os Autores descrevem um caso de paracoccidioidomicose subaguda progressiva, com quadro clínico sugestivo de síndrome de má absorção, em que o doente não se beneficiara apenas com o tratamento antifúngico convencional. Ao se introduzir como medida auxiliar a nutrição parenteral houve evidente melhora clínica e laboratorial. Desta maneira os Autores propõe o uso associado da nutrição parenteral no tratamento de doentes com esta forma clínica de paracoccidioidomicose.

Análise de terapias coadjuvantes de intervenção terapêutica na funcionalidade em doentes com acidente vascular encefálico

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Sousa, João Paulo de

2015-01-01

Projeto de Graduação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Licenciado em Fisioterapia Objectivo: Analisar as diferentes terapias coadjuvantes de intervenção terapêutica na funcionalidade de doentes com Acidente Vascular Encefálico (AVE). Metodologia: Foi realizada uma pesquisa nas bases de dados PubMed e PEDro. Foram utilizadas as palavras-chave: “stroke”, “physical therapy” e “outcome FIM”. Resultado: Obtiveram-se 144 estudos, após a...

Suporte relacionado ao cuidado em saúde ao doente com aids: o modelo de comboio e a enfermagem

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Edilene Aparecida Araújo da Silveira

2011-06-01

Full Text Available O presente estudo teve como objetivo conhecer a relação e a troca de suporte entre o doente com AIDS e pessoas à sua volta. O estudo está baseado no modelo de comboio das relações sociais que tem como uma de suas características a representação da rede em três círculos concêntricos. Os participantes eram pessoas que estavam internadas e que falaram sobre o suporte relacionado ao cuidado em saúde proporcionado por pessoas próximas, ou seja, que pertenciam ao círculo interno do comboio. A maioria dos participantes descreveu o círculo como sendo composto por no máximo cinco integrantes, sendo que pessoas da família foram as mais citadas. Os profissionais de saúde precisam conhecer o paciente e seu comboio, reconhecendo-os no contexto psicossocial e cultural de forma a favorecer a aceitação da soropositividade, mudanças no estilo de vida, ajuda nos cuidados de saúde e adesão ao tratamento.

Caracterização patológica e gênica (gene P53) dos tumores mamários em cadelas.

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Daniela Maria Bastos de Souza

2006-01-01

Os tumores mamários em cadelas tem alta incidência e malignidade sendo provocados por vários fatores de risco incluindo idade, atividade hormonal, nutrição, vírus, pseudogestação e administração de progestágenos exógenos. O gene p53, conhecido como um gene supressor de tumor, tem apresentado mutações relacionadas com neoplasias. Neste trabalho, o objetivo foi caracterizar os tumores mamários em cadelas, avaliar o comprometimento da mama lateral ao tumor e o envolvimento de fatores de risco...

Avaliação carotídea em doentes submetidos a revascularização miocárdica

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Luiz Roberto Felizzola

Full Text Available OBJETIVO: Como a doença carotídea é a principal causa isolada de acidente vascular cerebral de origem tromboembólica, acredita-se ser imprescindível o seu diagnóstico precoce. O presente estudo tem por objetivo realizá-lo, mantendo os conceitos de praticidade e viabilidade econômica, adequando-se às condições socioeconômicas desfavoráveis locais. MÉTODO: No período de 18 meses foram avaliados 50 doentes, sendo 35 homens e 15 mulheres, com média de idade de 67,2 anos. Todos apresentavam indicação de revascularização miocárdica, considerados coronariopatas graves. Avaliou-se a incidência e o grau de estenose carotídea com base no mapeamento dúplex. Da mesma forma, foi avaliada a relação com possíveis fatores de risco: diabetes melito, hipertensão arterial sistêmica, tabagismo, sintomatologia neurológica focal prévia, doença arterial troncular dos membros inferiores e presença de sopro carotídeo. RESULTADOS: A incidência de estenose carotídea hemodinamicamente significativa (>50% foi de 48%, e crítica (>70% de 32%. Mostraram-se fatores de risco estatisticamente significativos, antecedentes de diabetes melito, sintomatologia neurológica focal prévia, presença de sopro carotídeo e presença de alterações arteriais tronculares dos membros inferiores. CONCLUSÃO: Concluiu-se que no grupo estudado houve aumento significativo de risco para estenose carotídea hemodinamicamente significativa e crítica, em relação à população geral. Desta forma, justifica-se o rastreamento ultra-sonográfico para doença carotídea em doentes coronariopatas, principalmente quando os fatores de risco significativos se fizerem presentes.

Estudo da mutação do recetor do fator de crescimento epidérmico, durante 5 anos, numa população de doentes com cancro do pulmão de não pequenas células

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A.S. Castro

2013-01-01

Full Text Available Resumo: Introdução: Em 2006, a Unidade de Pneumologia Oncológica do Serviço de Pneumologia do Centro Hospitalar de Vila Nova de Gaia/Espinho iniciou a sequenciação da mutação do recetor do fator de crescimento epidérmico (EGFR em doentes com CPNPC selecionados e desde 2010 realiza a sequenciação sistematicamente em todos os doentes, independentemente da histologia, hábitos tabágicos, idade ou sexo. O objetivo deste trabalho foi caracterizar o grupo de doentes que efetuou a sequenciação entre 2006-2010, determinar a frequência da mutação EGFR, avaliar as sobrevidas globais e após uso de inibidores da tirosina quinase (ITK, nos doentes que efetuaram esta terapêutica em 2.a e 3.a linha com conhecimento do estado da mutação do EGFR. Métodos: Análise estatística descritiva dos doentes que efetuaram sequenciação EGFR em 2006-2010 e sobrevida mediana global nos doentes que efetuaefetuaram ITK em 2.a e 3.a linha. Registo do material disponível para análise e demora média de resultado do exame, de acordo com o material enviado. Resultados: A sequenciação foi efetuada em 374 doentes, 71,1% sexo masculino, 67,1% não/ex-fumadores, 32,9% fumadores; 57,8% adenocarcinoma e 23,5% carcinoma epidermoide (CE. A mutação foi detetada em 49 doentes (13,1%. No total dos doentes estudados, a taxa de mutação foi de 9% no sexo masculino e 23% no sexo feminino. A sobrevida mediana global após o uso de erlotinib foi de 14 meses para os doentes com mutação positiva do EGFR versus 6 meses nos doentes não mutados (p = 0,003. Conclusão: O nosso grupo teve uma taxa de mutação global de 13,1%, com predomínio no sexo feminino, não fumadores, histologia adenocarcinoma. Em doentes selecionados (2006/2009, a taxa de mutação foi de 16%; nos doentes não selecionados (2010 foi de 10,4%. Este estudo tem vindo a permitir um melhor conhecimento da taxa de mutação do EGFR na população portuguesa, bem como avaliar os resultados das

Reactivity of p53 protein in canine transmissible venereal tumor Reatividade da proteína P53 no tumor venéreo transmissível canino

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J.V. Moro

2010-04-01

Full Text Available The expression of p53 protein was evaluated in canine transmissible venereal tumor (CTVT, as following: natural occurrence (n=8; resistant to chemotherapy (n=4; and allogeneic transplanted in progression (n=8, stable (n=8, and regression (n=8stages. The collected specimens were submitted to GM1 immunohistochemical reaction. Results showed a mean percentage of immunomarked cells around 18.6% in CTVT of natural occurrence, 23.8% in CTVT resistant to chemotherapy, 22.9% in allogeneic transplanted CTVT in both progression and stable stages, and 35.8% in transplanted CTVT in regression stage. The results suggest that there is a functional abnormality in p53 gene and its products in the studied tumors; although, it is not possible to correlate the percentage of cells marked by p53 and a prognosis.A expressão da proteína p53 foi avaliada em espécimes de tumor venéreo transmissível canino (TVT de ocorrência natural (n=8; resistente à quimioterapia (n=4 e transplantado em cão nas fases de progressão tumoral (n=8, de latência (n=8 e de regressão (n=8. Os espécimes foram submetidos à reação de imunoistoquímica. Os resultados mostraram porcentagem média de células imunomarcadas de 18,6% no TVT de ocorrência natural, de 23,8% no TVT refratário, 22,9% nos TVTs transplantados nas fases de progressão e latência e de 35,8% na fase de regressão. Os resultados sugerem que há uma anormalidade funcional no gene P53 e seus produtos nos tumores estudados, apesar de não ser possível correlacionar a porcentagem de células marcadas pelo p53 ao prognóstico.

Inability of p53-reactivating compounds Nutlin-3 and RITA to overcome p53 resistance in tumor cells deficient in p53Ser46 phosphorylation.

Science.gov (United States)

Ma, Teng; Yamada, Shumpei; Ichwan, Solachuddin J A; Iseki, Sachiko; Ohtani, Kiyoshi; Otsu, Megumi; Ikeda, Masa-Aki

2012-01-20

The p53 tumor suppressor protein plays key roles in protecting cells from tumorigenesis. Phosphorylation of p53 at Ser46 (p53Ser46) is considered to be a crucial modification regulating p53-mediated apoptosis. Because the activity of p53 is impaired in most human cancers, restoration of wild-type p53 (wt-p53) function by its gene transfer or by p53-reactivating small molecules has been extensively investigated. The p53-reactivating compounds Nutlin-3 and RITA activate p53 in the absence of genotoxic stress by antagonizing the action of its negative regulator Mdm2. Although controversial, Nutlin-3 was shown to induce p53-mediated apoptosis in a manner independent of p53 phosphorylation. Recently, RITA was shown to induce apoptosis by promoting p53Ser46 phosphorylation. Here we examined whether Nutlin-3 or RITA can overcome resistance to p53-mediated apoptosis in p53-resistant tumor cell lines lacking the ability to phosphorylate p53Ser46. We show that Nutlin-3 did not rescue the apoptotic defect of a Ser46 phosphorylation-defective p53 mutant in p53-sensitive tumor cells, and that RITA neither restored p53Ser46 phosphorylation nor induced apoptosis in p53Ser46 phosphorylation-deficient cells retaining wt-p53. Furthermore, treatment with Nutlin-3 or RITA together with adenoviral p53 gene transfer also failed to induce apoptosis in p53Ser46 phosphorylation-deficient cells either expressing or lacking wt-p53. These results indicate that neither Nutlin-3 nor RITA in able to induce p53-mediated apoptosis in the absence of p53Ser46 phosphorylation. Thus, the dysregulation of this phosphorylation in tumor cells may be a critical factor that limits the efficacy of these p53-based cancer therapies. Copyright © 2011 Elsevier Inc. All rights reserved.

O papel da neutropenia no prognóstico do doente oncológico com pneumonia adquirida na comunidade The role of neutropenia on outcomes of cancer patients with community-acquired pneumonia

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Fátima Caeiro

2009-08-01

Full Text Available A doença infecciosa contribui para uma elevada morbilidade e mortalidade no doente oncológico, representando a pneumonia adquirida na comunidade a mais frequente. O desenvolvimento de PAC no doente neoplásico parece advir da modificação de mecanismos de defesa imunitária resultante, quer da patologia maligna, quer do tratamento oncológico. O risco de infecção relacionada com o tipo de neoplasia pode associar-se ao défice de imunidade humoral, celular ou do número de neutrófilos. As doenças hematológicas malignas podem predispor o doente às infecções devido à substituição da medula por células neoplásicas. Consequentemente, estes doentes têm neutropenia funcional, apesar de apresentarem, muitas vezes, um número normal ou aumentado de neutrófilos. Por outro lado, estes doentes podem ter neutropenia como efeito secundário da quimioterapia e/ou radioterapia (neutropenia absoluta. A gravidade da neutropenia foi considerada como principal factor de risco isolado no doente neoplásico, com particular relevância se o número de neutrófilos ≤500cel/mm³. A mortalidade global atribuída à neutropenia febril no doente neoplásico é de 30-50%. Nas últimas décadas, o tratamento das infecções na população oncológica foi direccionado, primariamente, para o manuseamento da neutropenia febril, devido ao facto de o local da infecção não ser determinado em 50-80% dos casos. As guidelines da American Thoracic Society de 2001 utilizavam a neutropenia para identificar os quadros mais graves de PAC nos doentes oncológicos. Os doen tes com patologia hematológica e neutropenia funcional ou indivíduos com qualquer tipo de neoplasia e neutropenia absoluta foram excluídos das referidas guidelines. A decisão de incluir doentes com tumores sólidos não neutropénicos foi baseada, apenas, na opinião de especialistas. Assim, os clínicos podiam sentir-se confiantes e tratar a PAC no doente oncológico não neutropénico como na

Peso corporal e comorbilidade são indicadores da mortalidade em doentes com DPOC sob oxigenioterapia Body weight and comorbidity predict mortality in COPD patients treated with oxygen therapy

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S Marti

2007-01-01

1 a 6 proporcional ao risco de morte relacionado com a referida patologia. O score 1 é atribuído ao EAM, insuficiência cardíaca congestiva, doença vascular periférica, doença cerebrovascular, demência, conectivopatia, doença péptica, doença hepática ligeira e diabetes. O score 2 é conferido à diabetes com lesão orgânica múltipla, hemiplegia, doença renal e neoplasias, incluindo leucemia e linfomas. O score 3 é atribuído à doença hepática moderadamente grave, enquanto o score 6 às doenças neoplásicas metastizadas e à SIDA. A DPOC foi excluída desta lista. No presente estudo foram incluídos 128 doentes de um total de 202 indivíduos com DPOC sob oxigenioterapia domiciliária de longa duração. A maioria dos doentes era do sexo masculino (98% com uma idade média de 68,9±9,7 anos. A distribuição de acordo com o índice de massa corporal (IMC foi a seguinte: IMC 45mmHg em 81 casos - 63%. As patologias associadas mais frequentes foram a diabetes e a doença cardiovascular. O follow-up foi efectuado por pneumologistas em 73% dos indivíduos e clínicos gerais nos restantes, ao longo de 3,2 anos. Em 6 indivíduos, o follow-up terminou antes da referida data pela instituição de outra medida terapêutica: ventiloterapia não invasiva (3; transplante pulmonar (2 e cirurgia de redução de volume (1. O follow-up incluía o controlo da oxigenioterapia de forma a avaliar a compliance do doente e a necessidade de ajuste de aporte do oxigénio. As causas de morte foram obtidas através do registo de mortalidade catalão baseado na informação contida nas certidões de óbito e codificadas de acordo com a 10.ª Revisão da Classificação de Doenças internacional (ICD. Um total de 78 indivíduos (61% faleceu no decurso do período de follow-up. A taxa de sobrevivência aos 3 anos foi de 55%. A mortalidade por patologia respiratória foi de 77%. A comorbilidade avaliada pelo índice de Charlson estava presente em 38% dos doentes. Um IMC <25 kg

O papel moderador do tipo de família na relação entre incapacidade funcional e qualidade de vida em doentes com lombalgia crônica

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Maria Salomé Martins Ferreira

2016-01-01

Full Text Available Resumo A lombalgia crônica constituise como uma doença que interfere na qualidade de vida e na capacidade funcional do paciente. Este estudo teve por objetivo identificar o efeito moderador do “Tipo de Família” na relação entre a incapacidade funcional e a qualidade de vida em doentes com lombalgia crônica. Participaram no estudo 213 pacientes com lombalgia há mais de 3 meses. Os instrumentos utilizados foram: Medical Outcome Study (MOS-20; Roland Morris Disability Questionnaire (RMDQ; Family Adaptability and Cohesion Evaluation Scales (FACES II. Foram realizadas análises de regressão com o objetivo de testar o efeito moderador do tipo de família. Os resultados revelaram que os doentes com níveis mais baixos de incapacidade funcional apresentavam melhor qualidade de vida nas famílias intermédias e equilibradas, com relação mais forte nestas últimas. De acordo com os resultados, os programas de intervenção na lombalgia crônica, além do doente, devem incluir a família, particularmente nas equilibradas, que são as que mais sentem o impacto da doença na sua qualidade de vida.

O papel da neutropenia no prognóstico do doente oncológico com pneumonia adquirida na comunidade** Eur Respir J 2009; 33:142-147

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S. Aliberti

2009-07-01

Full Text Available Resumo: A doença infecciosa contribui para uma elevada morbilidade e mortalidade no doente oncológico, representando a pneumonia adquirida na comunidade a mais frequente.O desenvolvimento de PAC no doente neoplásico pa-rece advir da modificação de mecanismos de defesa imunitária resultante, quer da patologia maligna, quer do tratamento oncológico. O risco de infecção relacionada com o tipo de neoplasia pode associarse ao défice de imunidade humoral, celular ou do número de neutrófilos. As doenças hematológicas malignas podem predispor o doente às infecções devido à substituição da medula por células neoplásicas. Consequentemente, estes doentes têm neutropenia funcional, apesar de apresentarem, muitas vezes, um número normal ou aumentado de neutrófilos. Por outro lado, estes doentes podem ter neutropenia como efeito secundário da quimioterapia e/ou radioterapia (neutropenia absoluta.A gravidade da neutropenia foi considerada como principal factor de risco isolado no doente neoplásico, com particular relevância se o número de neutrófilos ≤500cel/mm3.A mortalidade global atribuída à neutropenia febril no doente neoplásico é de 30-50%. Nas últimas décadas, o tratamento das infecções na população oncológica foi direccionado, primariamente, para o manuseamento da neutropenia febril, devido ao facto de o local da infecção não ser determinado em 50-80% dos casos. As guidelines da American Thoracic Society de 2001 utilizavam a neutropenia para identificar os quadros mais graves de PAC nos doentes oncológicos. Os doentes com patologia hematológica e neutropenia funcional ou indivíduos com qualquer tipo de neoplasia e neutropenia absoluta foram excluídos das referidas guidelines. A decisão de incluir doentes com tumores sólidos não neutropénicos foi baseada, apenas, na opinião de especialistas

Determination of carcinoembryonic antigen levels in peripheral and draining venous blood in patients with colorectal carcinoma Determinação dos níveis do antígeno carcinoembriônico no sangue periférico e no efluente venoso em doentes com carcinoma colorretal

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Jaques Waisberg

2004-06-01

greater than 5 ng/mL. CONCLUSION: The CEA-p and CEA-d levels in the colorectal carcinoma patients were not shown to be different. The results from this study suggest that, in colorectal neoplasm without venous invasion, there may not be notable CEA drainage from the tumor by the portal vein effluent blood.RACIONAL: O problema da relação entre os níveis de CEA no sangue e o conteúdo de CEA tissular no carcinoma colorretal e os mecanismos de liberação do CEA das células neoplásicas nos tecidos vizinhos à neoplasia e sua conseqüente entrada dentro do sangue periférico são importantes para o entendimento da biologia do carcinoma colorretal. Ainda não foi convenientemente elucidado se o CEA no sangue é drenado principalmente pelo sangue do sistema portal ou pelos linfáticos para o ducto torácico ou, ainda, por ambos os sistemas. OBJETIVO: Estudar o comportamento dos níveis do CEA no sangue periférico (CEA-p e no sangue do efluente venoso (CEA-d de doentes com tumores colorretais operados curativamente. MÉTODO: foram estudados 28 doentes, sendo 12 (42,9% homens e 16 (57,1% mulheres. A média de idade foi de 66,1 anos (43 a 84 anos. Imediatamente após a laparotomia, o sangue venoso periférico foi extraído por punção venosa antecubital e o sangue do efluente venoso coletado da veia principal de drenagem das lesões. Os valores de CEA-p, CEA-d e do gradiente entre o CEA-d e CEA-p abaixo de 5,0 ng/mL foram considerados normais. RESULTADOS: Oito (28,6% doentes foram classificados no estádio A de Dukes, 9 (32,1% no estádio B e 11 (39,3% no estádio C. A neoplasia estava localizada no reto em 14 (50,0%, no cólon transverso em 5 (17,9%, no cólon sigmóide em 4 (14,3%, no ceco e/ou cólon ascendente em 3 (10,7%, e no cólon descendente em 2 (7,1% enfermos. O exame histopatológico revelou adenocarcinoma bem diferenciado em todos os enfermos. Em apenas um (3,6% doente a neoplasia, estadiada como Dukes C, exibia invasão venosa. O gradiente entre os níveis de

INGN 201: Ad-p53, Ad5CMV-p53, Adenoviral p53, INGN 101, p53 gene therapy--Introgen, RPR/INGN 201.

Science.gov (United States)

2003-01-01

Introgen's adenoviral p53 gene therapy [INGN 201, ADVEXIN] is in clinical development for the treatment of various cancers. The p53 tumour suppressor gene is deleted or mutated in many tumour cells and is one of the most frequently mutated genes in human tumours. INGN 201 has been shown to kill cancer cells directly. In August 2002, Introgen announced plans to file an application for INGN 201 with the European Agency for the Evaluation of Medicinal Products (EMEA) for the treatment of head and neck cancer; the European filing will be submitted simultaneously with the previously scheduled (planned for 2004) submission of a Biologics License Application (BLA) for ADVEXIN to the US FDA. On 20 February 2003, INGN 201 received orphan drug designation from the US FDA for head and neck cancer. INGN 201 is available for licensing although Introgen favours retaining partial or full rights to the therapy in the US. Introgen Therapeutics and its collaborative partner for the p53 programme, Aventis Gencell, have been developing p53 gene therapy products. The agreement was originally signed by Rhône-Poulenc Rorer's Gencell division, which became Aventis Gencell after Rhône-Poulenc Rorer merged with Hoechst Marion Roussel to form Aventis Pharma. According to the original agreement, Introgen was responsible for phase I and preclinical development in North America, while Aventis Gencell was responsible for clinical trials conducted in Europe and for clinical trials in North America beyond phase I. In April 2001, Aventis Gencell and Introgen restructured their existing collaboration agreement for p53 gene therapy products. Aventis Gencell indicated that p53 research had suffered from internal competition for resources and was pulling back from its development agreement with Introgen for p53 gene therapy products. Introgen will assume responsibility for worldwide development of all p53 programmes and will obtain exclusive worldwide commercial rights to p53-based gene therapy

Elevação da lipase e amilase no doente crítico: estudo retrospectivo Increased lipase and amilase levels in critically ill patients: retrospective study

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Margarida Ferreira

2008-12-01

Full Text Available OBJETIVOS: A elevação da lipase e amilase séricas são frequentemente encontradas em doentes internados em unidade de terapia intensiva sem que exista doença pancreática prévia, constituindo um desafio diagnóstico e terapêutico. Baseados nesta evidência os autores propuseram-se a determinar a incidência de hiperlipasemia assintomática nos doentes críticos, fatores desencadeantes e evolução clínica destes doentes. MÉTODOS: Estudo retrospectivo dos doentes internados na unidade de terapia intensiva de 1 de janeiro a 31 de dezembro de 2006, excluídas internações por pancreatite aguda, história de patologia pancreática, insuficiência renal ou falta de dados. Pacientes foram distribuídos em dois grupos (com e sem hiperlipasemia e feita comparação considerando diversas variáveis clínicas, laboratoriais, imagiológicas. Análise estatística: SPSS 13; testes t de Student e qui² (IC 95%, com significância estatística se p38 ºC (pOBJECTIVES: Elevated lipase and amylase are commonly found in patients in intensive care unit without a previously recognized pancreatic illness, constituting a diagnostic and therapeutic challenge. The authors therefore proposed to determine the frequency of asymptomatic high serum lipase in critically ill patients, involved risk factors and outcome. METHODS: Retrospective study of patients admitted in an intensive care unit from January 1 to December 31, 2006, excluding admissions for acute pancreatitis, history of pancreatic disease, renal insufficiency or lacking of data. Patients were divided in two groups (with and without high serum lipase that were compared for clinical, laboratory and radiological variables. Statistical analysis: SPSS 13; Student's t test and Chi-square test (CI 95% with statistical significance if p< 0.05. RESULTS: 102 patients were included with high serum lipase was present in 39.2% of patients, mean lipase of 797U/L. Patients with high serum lipase had longer hospital

Tratamento de doença bílio-pancreática em pacientes portadores de divertículo duodenal periampolar

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Carlos Roberto Puglia

Full Text Available OBJETIVO: Analisar o tratamento da doença bílio-pancreática na presença do divertículo periampolar. MÉTODO: De janeiro de 1999 a julho de 2003, 13 doentes com diagnóstico de divertículo periampolar e doença bílio-pancreática associada foram tratados pelo grupo de vias biliares e pâncreas do Departamento de Cirurgia da Santa Casa de São Paulo. Foram analisados retrospectivamente quanto à idade, sexo, quadro clínico e exames laboratoriais e radiológicos, com intuito diagnóstico. O tratamento endoscópico ou cirúrgico e seus resultados foram avaliados. RESULTADOS: Quatro pacientes eram do sexo masculino (30,8% e nove (69,2% do sexo feminino, a maioria com idade superior a 70 anos. Os principais sintomas foram de icterícia (61,5% e dor abdominal (53,8%. Dois doentes apresentaram-se com pancreatite aguda e um com hemorragia digestiva alta. Onze doentes tinham coledocolitíase e dois, diagnóstico de colangiocarcinoma. Dez doentes foram submetidos a colangio-pancreatografia retrógrada endoscópica com 30% de sucesso no tratamento da coledocolitíase. Os outros doentes foram operados: três coledocoduodenostomias, quatro coledocolitotomias com drenagem em T da via biliar. Três doentes foram submetidos à diverticulectomia (23,1% e um deles (7,7% à papiloesfincteroplastia. A mortalidade na amostra foi de 7,7%. CONCLUSÃO: A taxa de sucesso do tratamento endoscópico da coledocolitíase foi baixa na presença de divertículo periampolar e a diverticulectomia com ou sem esfincteroplastia pode elevar a morbidade e a mortalidade nestes doentes.

Inhibition of p53 acetylation by INHAT subunit SET/TAF-Iβ represses p53 activity.

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Kim, Ji-Young; Lee, Kyu-Sun; Seol, Jin-Ee; Yu, Kweon; Chakravarti, Debabrata; Seo, Sang-Beom

2012-01-01

The tumor suppressor p53 responds to a wide variety of cellular stress signals. Among potential regulatory pathways, post-translational modifications such as acetylation by CBP/p300 and PCAF have been suggested for modulation of p53 activity. However, exactly how p53 acetylation is modulated remains poorly understood. Here, we found that SET/TAF-Iβ inhibited p300- and PCAF-mediated p53 acetylation in an INHAT (inhibitor of histone acetyltransferase) domain-dependent manner. SET/TAF-Iβ interacted with p53 and repressed transcription of p53 target genes. Consequently, SET/TAF-Iβ blocked both p53-mediated cell cycle arrest and apoptosis in response to cellular stress. Using different apoptosis analyses, including FACS, TUNEL and BrdU incorporation assays, we also found that SET/TAF-Iβ induced cellular proliferation via inhibition of p53 acetylation. Furthermore, we observed that apoptotic Drosophila eye phenotype induced by either dp53 overexpression or UV irradiation was rescued by expression of dSet. Inhibition of dp53 acetylation by dSet was observed in both cases. Our findings provide new insights into the regulation of stress-induced p53 activation by HAT-inhibiting histone chaperone SET/TAF-Iβ.

O treino ao exercício melhora a dispneia de esforço em doentes com DPOC. Papel dos factores mecânicos

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F. Gigliotti

2003-11-01

ção neuroventilatória. Se, por um lado, impõe aos músculos respiratórios uma maior carga elástica, obrigando a um maior esforço para que se possa manter um nível ventilatório adequado, por outro, a hiperinsuflação reduz a contractilidade máxima dos músculos que passam a operar numa relação comprimento/tensão mais desfavorável.Esta sensação de maior esforço, que não se traduz em variações proporcionais de débitos e volumes, constitui a dissociação neuromecânica ou neuroventilatória e tem como consequência a dispneia7.No trabalho que comentamos, para uma mesma carga suportada, o exercício reduziu a dispneia ao diminuir o esforço inspiratório, a hiperinsuflação pulmonar e a frequência respiratória, melhorando assim o coupling neuroventilatório.Outras formas terapêuticas, como a administração de broncodilatadores, também podem reduzir a dispneia de esforço nos doentes com DPOC, o que pode ser atribuído igualmente à redução da hiperinsuflação pulmonar e à melhoria do coupling neuroventilatório, já que nestes doentes não existe habitualmente um aumento importante dos débitos expiratórios8. Na maioria dos casos, o aumento do FEV1 com a broncodilatação não ultrapassa os 12%.Para além da coupling neuroventilatória, os autores pretenderam neste estudo avaliar os efeitos do treino ao exercício na drive ventilatória central. Durante muitos anos, o aparecimento da hipercapnia nos doentes com DPOC foi interpretado como consequência de uma redução do estímulo ventilatório que parte dos centros respiratórios (drive para os músculos respiratórios. Sabe-se hoje que, quando comparados com indivíduos saudáveis, os doentes com DPOC apresentam antes uma drive ventilatória aumentada9. Esta pode ser avaliada pela pressão de oclusão (P0.1, pela variação da ventilação (VE ou pelo

Detecção imunoistoquímica das oncoproteínas p21ras, c-myc E p53 no carcinoma hepatocelular e no tecido hepático não-neoplásico Immunohistochemical detection of p21ras, c-myc and p53 oncoproteins in hepatocellular carcinoma and in non-neoplastic liver tissue

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Vera Lucia Nunes Pannain

2004-12-01

Full Text Available RACIONAL: A hepatocarcinogênese é um processo no qual as alterações genéticas e epigenéticas são bem conhecidas em modelos animais, mas carece de estudos no homem. OBJETIVOS: Analisar a freqüência das oncoproteínas p21ras, c-myc e p53 no carcinoma hepatocelular e no fígado não-neoplásico. Verificar ainda a associação destas oncoproteínas com os padrões e graus histológicos, assim como com as infecções pelos vírus das hepatites B e C. MÉTODOS: Foi analisada por método imunoistoquímico a detecção das oncoproteínas p21ras, c-myc e p53 em 47 casos de carcinoma hepatocelular e no tecido não-neoplásico circunjacente ao tumor (40 casos. RESULTADOS: As oncoproteínas p21ras, c-myc e p53 foram detectadas, respectivamente, em 44,7%, 53,2% e 36,2% dos casos de carcinoma hepatocelular. A imunorreatividade do p21ras e c-myc mostrou uma associação significativa. Contudo, não houve associação significativa entre a detecção do p21ras, c-myc e p53 com os diferentes graus e padrões histológicos, nem tampouco com as infecções pelos vírus das hepatites B e C. A mesma associação significativa entre o p21ras e c-myc foi encontrada no tecido não-neoplásico dos casos de cirrose em relação aos que não apresentaram cirrose, enquanto que o p53 foi negativo em todos os casos. CONCLUSÕES: A imunorreatividade das oncoproteínas p21ras, c-myc e p53 corrobora evidências prévias de sua detecção no carcinoma hepatocelular, o que sugere poder haver participação destas proteínas na hepatocarcinogênese humana. A significativa associação entre as proteínas p21ras, c-myc e p53 no carcinoma hepatocelular e na cirrose pode apontar uma interação entre as mesmas, sobretudo na hepatocarcinogênese pela via da cirrose.BACKGROUND: Genetic and epigenetic alterations have been described in animal hepatocarcinogenesis models but need to be studied in human being. AIMS: To assess the immunoreactivity of p21ras, c-myc and p53

Nuclear inclusion bodies of mutant and wild-type p53 in cancer: a hallmark of p53 inactivation and proteostasis remodelling by p53 aggregation.

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De Smet, Frederik; Saiz Rubio, Mirian; Hompes, Daphne; Naus, Evelyne; De Baets, Greet; Langenberg, Tobias; Hipp, Mark S; Houben, Bert; Claes, Filip; Charbonneau, Sarah; Delgado Blanco, Javier; Plaisance, Stephane; Ramkissoon, Shakti; Ramkissoon, Lori; Simons, Colinda; van den Brandt, Piet; Weijenberg, Matty; Van England, Manon; Lambrechts, Sandrina; Amant, Frederic; D'Hoore, André; Ligon, Keith L; Sagaert, Xavier; Schymkowitz, Joost; Rousseau, Frederic

2017-05-01

Although p53 protein aggregates have been observed in cancer cell lines and tumour tissue, their impact in cancer remains largely unknown. Here, we extensively screened for p53 aggregation phenotypes in tumour biopsies, and identified nuclear inclusion bodies (nIBs) of transcriptionally inactive mutant or wild-type p53 as the most frequent aggregation-like phenotype across six different cancer types. p53-positive nIBs co-stained with nuclear aggregation markers, and shared molecular hallmarks of nIBs commonly found in neurodegenerative disorders. In cell culture, tumour-associated stress was a strong inducer of p53 aggregation and nIB formation. This was most prominent for mutant p53, but could also be observed in wild-type p53 cell lines, for which nIB formation correlated with the loss of p53's transcriptional activity. Importantly, protein aggregation also fuelled the dysregulation of the proteostasis network in the tumour cell by inducing a hyperactivated, oncogenic heat-shock response, to which tumours are commonly addicted, and by overloading the proteasomal degradation system, an observation that was most pronounced for structurally destabilized mutant p53. Patients showing tumours with p53-positive nIBs suffered from a poor clinical outcome, similar to those with loss of p53 expression, and tumour biopsies showed a differential proteostatic expression profile associated with p53-positive nIBs. p53-positive nIBs therefore highlight a malignant state of the tumour that results from the interplay between (1) the functional inactivation of p53 through mutation and/or aggregation, and (2) microenvironmental stress, a combination that catalyses proteostatic dysregulation. This study highlights several unexpected clinical, biological and therapeutically unexplored parallels between cancer and neurodegeneration. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2016 Pathological Society of Great

Presença da Proteína p53 como Prognóstico de Recidiva/Progressão de Neoplasia Intra-epitelial Vulvar III p53 Protein Overexpression as a Prognostic Marker for Vulvar Intraepithelial Neoplasia III Recurrence/Progression

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Isabel Cristina Chulvis do Val Guimarães

2002-01-01

Full Text Available Objetivo: avaliar o valor da presença da proteína p53 nos casos de recidiva/progressão da neoplasia intra-epitelial vulvar (VIN III. Métodos: foram selecionadas 20 pacientes com VIN III indiferenciada, seguidas semestralmente por período de até quatro anos, divididas em dois grupos: quatorze sem e seis com recidiva/progressão da lesão. Os casos de recidiva/progressão foram distribuídos da seguinte forma: em três pacientes a recidiva ocorreu uma única vez, em duas, houve dupla recorrência e apenas uma evoluiu para carcinoma escamoso. Em ambos os grupos foram avaliados o sítio vulvar acometido e a presença da proteína p53 com análise do padrão de marcação imunohistoquímica. Estudo semelhante foi realizado nos casos de recidiva/progressão além da análise do intervalo de tempo para o surgimento de recidiva/progressão. Resultados: observou-se recidiva da VIN III em 25% dos casos e, em 5%, progressão para carcinoma. O tempo médio de recidiva foi de 24,5 meses. A localização multifocal da lesão primária foi a mais freqüente (50% em ambos os grupos. Na maioria dos casos (87,5%, a recidiva/progressão ocorreu na mesma localização da lesão vulvar primária. A presença da proteína p53 mostrou-se positiva em 50% das lesões primárias de VIN III e em 75% dos casos de recidiva/progressão. Conclusões: a presença da proteína p53 parece desempenhar papel importante na gênese e na predição do curso clínico das VIN III. As recidivas/progressão das VIN III tendem a ocorrer na mesma área da doença inicial, sugerindo a presença de campo molecular alterado.Purpose: to evaluate p53 overexpression value in vulvar intraepithelial neoplasia (VIN III recurrence/progression. Methods: twenty patients with undifferentiated VIN III were selected and followed up every six months for four years and divided into two groups: fourteen without and six with recurrence/progression lesion. The recurrence/progression cases were

p53 Aggregates penetrate cells and induce the co-aggregation of intracellular p53.

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Karolyn J Forget

Full Text Available Prion diseases are unique pathologies in which the infectious particles are prions, a protein aggregate. The prion protein has many particular features, such as spontaneous aggregation, conformation transmission to other native PrP proteins and transmission from an individual to another. Protein aggregation is now frequently associated to many human diseases, for example Alzheimer's disease, Parkinson's disease or type 2 diabetes. A few proteins associated to these conformational diseases are part of a new category of proteins, called prionoids: proteins that share some, but not all, of the characteristics associated with prions. The p53 protein, a transcription factor that plays a major role in cancer, has recently been suggested to be a possible prionoid. The protein has been shown to accumulate in multiple cancer cell types, and its aggregation has also been reproduced in vitro by many independent groups. These observations suggest a role for p53 aggregates in cancer development. This study aims to test the «prion-like» features of p53. Our results show in vitro aggregation of the full length and N-terminally truncated protein (p53C, and penetration of these aggregates into cells. According to our findings, the aggregates enter cells using macropinocytosis, a non-specific pathway of entry. Lastly, we also show that once internalized by the cell, p53C aggregates can co-aggregate with endogenous p53 protein. Together, these findings suggest prion-like characteristics for p53 protein, based on the fact that p53 can spontaneously aggregate, these aggregates can penetrate cells and co-aggregate with cellular p53.

Glycerol restores the p53 function in human lingual cancer cells bearing mutant p53

International Nuclear Information System (INIS)

Ota, Ichiro; Yane, Katsunari; Yuki, Kazue; Kanata, Hirokazu; Hosoi, Hiroshi; Miyahara, Hiroshi

2001-01-01

Mutations in p53, tumor suppressor gene, have recently been shown to have an impact on the clinical course of several human tumors, including head and neck cancers. The genetic status of the p53 gene has been focused on as the most important candidate among various cancer-related genes for prognosis-predictive assays of cancer therapy. We examined the restoration of radiation- or cisplatin (CDDP)-induced p53-dependent apoptosis in human lingual cancer cells. The results suggest that glycerol is effective in inducing a conformational change of p53 and restoring normal function of mutant p53, leading to enhanced radiosensitivity or chemosensitivity through the induction of apoptosis. We have also represented the same results in vivo as in vitro. Thus, this novel tool for enhancement of radiosensitivity or chemosensitivity in cancer cells bearing m p53 may be applicable for p53-targeted cancer therapy. (author)

p53 Acetylation: Regulation and Consequences

International Nuclear Information System (INIS)

Reed, Sara M.; Quelle, Dawn E.

2014-01-01

Post-translational modifications of p53 are critical in modulating its tumor suppressive functions. Ubiquitylation, for example, plays a major role in dictating p53 stability, subcellular localization and transcriptional vs. non-transcriptional activities. Less is known about p53 acetylation. It has been shown to govern p53 transcriptional activity, selection of growth inhibitory vs. apoptotic gene targets, and biological outcomes in response to diverse cellular insults. Yet recent in vivo evidence from mouse models questions the importance of p53 acetylation (at least at certain sites) as well as canonical p53 functions (cell cycle arrest, senescence and apoptosis) to tumor suppression. This review discusses the cumulative findings regarding p53 acetylation, with a focus on the acetyltransferases that modify p53 and the mechanisms regulating their activity. We also evaluate what is known regarding the influence of other post-translational modifications of p53 on its acetylation, and conclude with the current outlook on how p53 acetylation affects tumor suppression. Due to redundancies in p53 control and growing understanding that individual modifications largely fine-tune p53 activity rather than switch it on or off, many questions still remain about the physiological importance of p53 acetylation to its role in preventing cancer

p53 Acetylation: Regulation and Consequences

Energy Technology Data Exchange (ETDEWEB)

Reed, Sara M. [Department of Pharmacology, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); Medical Scientist Training Program, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); Quelle, Dawn E., E-mail: dawn-quelle@uiowa.edu [Department of Pharmacology, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); Medical Scientist Training Program, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); Department of Pathology, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States)

2014-12-23

Post-translational modifications of p53 are critical in modulating its tumor suppressive functions. Ubiquitylation, for example, plays a major role in dictating p53 stability, subcellular localization and transcriptional vs. non-transcriptional activities. Less is known about p53 acetylation. It has been shown to govern p53 transcriptional activity, selection of growth inhibitory vs. apoptotic gene targets, and biological outcomes in response to diverse cellular insults. Yet recent in vivo evidence from mouse models questions the importance of p53 acetylation (at least at certain sites) as well as canonical p53 functions (cell cycle arrest, senescence and apoptosis) to tumor suppression. This review discusses the cumulative findings regarding p53 acetylation, with a focus on the acetyltransferases that modify p53 and the mechanisms regulating their activity. We also evaluate what is known regarding the influence of other post-translational modifications of p53 on its acetylation, and conclude with the current outlook on how p53 acetylation affects tumor suppression. Due to redundancies in p53 control and growing understanding that individual modifications largely fine-tune p53 activity rather than switch it on or off, many questions still remain about the physiological importance of p53 acetylation to its role in preventing cancer.

Hypophosphatemia in critically ill children Hipofosfatemia em crianças gravemente doentes

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Fernanda Souza de Menezes

2004-01-01

Full Text Available The purpose of this paper is to review clinical studies on hypophosphatemia in pediatric intensive care unit patients with a view to verifying prevalence and risk factors associated with this disorder. We searched the computerized bibliographic databases Medline, Embase, Cochrane Library, and LILACS to identify eligible studies. Search terms included critically ill, pediatric intensive care, trauma, sepsis, infectious diseases, malnutrition, inflammatory response, surgery, starvation, respiratory failure, diuretic, steroid, antiacid therapy, mechanical ventilation. The search period covered those clinical trials published from January 1990 to January 2004. Studies concerning endocrinological disorders, genetic syndromes, rickets, renal diseases, anorexia nervosa, alcohol abuse, and prematurity were not included in this review. Out of 27 studies retrieved, only 8 involved pediatric patients, and most of these were case reports. One clinical trial and one retrospective study were identified. The prevalence of hypophosphatemia exceeded 50%. The commonly associated factors in most patients with hypophosphatemia were refeeding syndrome, malnutrition, sepsis, trauma, and diuretic and steroid therapy. Given the high prevalence, clinical manifestations, and multiple risk factors, the early identification of this disorder in critically ill children is crucial for adequate replacement therapy and also to avoid complications.Este estudo objetivou realizar revisão da literatura para verificar prevalência, fatores de risco e condições clínicas associadas à hipofosfatemia em crianças gravemente doentes. Para a pesquisa foram utilizadas as bases de dados Medline, Embase, Cochrane Library, Lilacs abrangendo estudos clínicos publicados de janeiro de 1990 a janeiro de 2004. Os termos utilizados para pesquisa foram: critically ill, pediatric intensive care, trauma, sepsis, infectious diseases, malnutrition, inflammatory response, surgery, starvation

Neoplasias astrocitárias e correlação com as proteínas p53 mutada e Ki-67 Astrocytic neoplasms and correlation with mutate p53 and Ki-67 proteins

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Gustavo Rassier Isolan

2005-12-01

Full Text Available As neoplasias astrocitárias correspondem a 60% dos tumores do sistema nervoso central, sendo o estudo da biologia molecular um importante passo para a compreensão da gênese e comportamento biológico destas doenças. As proteínas Ki-67, que é um marcador de proliferação celular, e p53, que é o produto do gene supressor de tumor de mesmo nome, são importantes marcadores tumorais. O objetivo deste estudo foi identificar e quantificar as proteínas Ki-67 e produto do gene supressor de tumor TP53 em diferentes graus de malignidade das neoplasias astrocitárias, bem como analisar suas relações com idade e sexo. Foram estudadas por imuno-histoquímica as proteínas Ki-67 e p53 em 47 pacientes com neoplasias astrocitárias ressecadas cirurgicamente, classificadas previamente e revisadas quanto ao grau de malignidade, de acordo com o proposto pela Organização Mundial da Saúde. Os núcleos celulares imunomarcados foram quantificados no programa Imagelab-softium pela razão paramétrica absoluta entre os núcleos de células positivas e o número total de células tumorais, sendo contadas 1000 células. O delineamento utilizado foi transversal não controlado. Para análise estatística as variáveis foram divididas em grupos, que para a Ki-67 foram ausente, 5% e para a p53 foram ausente (0, The astrocytic neoplasms respond by 60% of the central nervous system tumors, being the study of the molecular biology an important step for the understanding of the genesis and biological behavior of these diseases. The Ki-67 proteins, which are markers of the cellular proliferation, and p53, which is the product of the tumor suppressor gene TP53, are both important tumoral markers. This study intends to identify and quantify the Ki-67 and p53 proteins in astrocytic tumors of different grades of malignancy, as well as to analyze their relations with age and gender. Ki-67 and p53 proteins in 47 patients with surgically resected astrocytic neoplasms were

Estudo das manifestações neurológicas em 93 doentes com intoxicação exógena por substancias químicas não medicamentosas

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S. Agapejev

1986-09-01

Full Text Available Foram analisadas as manifestações neurológicas em 93 doentes com suspeita de intoxicação exógena. A detecção das substancias tóxicas foi realizada no sangue, urina e líquido cefalorraqueano. Verificou-se nítido predomínio do comprometimento do sistema nervoso central em relação ao periférico e aparente tropismo de herbicidas e organofosforados para o sistema nervoso central, comparando-se o comportamento dos metais pesados e organoclorados. São analisados os prováveis mecanismos de ação dessas substancias no sistema nervoso e são apresentados os sinais e/ou sintomas que foram observados.

Urodele p53 tolerates amino acid changes found in p53 variants linked to human cancer

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Villiard Éric

2007-09-01

Full Text Available Abstract Background Urodele amphibians like the axolotl are unique among vertebrates in their ability to regenerate and their resistance to develop cancers. It is unknown whether these traits are linked at the molecular level. Results Blocking p53 signaling in axolotls using the p53 inhibitor, pifithrin-α, inhibited limb regeneration and the expression of p53 target genes such as Mdm2 and Gadd45, suggesting a link between tumor suppression and regeneration. To understand this relationship we cloned the p53 gene from axolotl. When comparing its sequence with p53 from other organisms, and more specifically human we observed multiple amino acids changes found in human tumors. Phylogenetic analysis of p53 protein sequences from various species is in general agreement with standard vertebrate phylogeny; however, both mice-like rodents and teleost fishes are fast evolving. This leads to long branch attraction resulting in an artefactual basal emergence of these groups in the phylogenetic tree. It is tempting to assume a correlation between certain life style traits (e.g. lifespan and the evolutionary rate of the corresponding p53 sequences. Functional assays of the axolotl p53 in human or axolotl cells using p53 promoter reporters demonstrated a temperature sensitivity (ts, which was further confirmed by performing colony assays at 37°C. In addition, axolotl p53 was capable of efficient transactivation at the Hmd2 promoter but has moderate activity at the p21 promoter. Endogenous axolotl p53 was activated following UV irradiation (100 j/m2 or treatment with an alkylating agent as measured using serine 15 phosphorylation and the expression of the endogenous p53 target Gadd45. Conclusion Urodele p53 may play a role in regeneration and has evolved to contain multiple amino acid changes predicted to render the human protein defective in tumor suppression. Some of these mutations were probably selected to maintain p53 activity at low temperature. However

Impacto do ecocardiograma transesofágico intraoperatório na mortalidade em cirurgia de revascularização do miocárdio com circulação extracorpórea

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Marcello Fonseca Salgado Filho

Full Text Available OBJETIVO: avaliar as taxas de mortalidade e morbidade de doentes submetidos à revascularização do miocárdio (RVM com circulação extracorpórea (CEC que utilizaram rotineiramente o ecocardiograma transesofágico intraoperatório (ETEio. MÉTODOS: estudo retrospectivo, observacional com avaliação de prontuários de 360 doentes no período entre abril de 2010 a abril de 2012. Foram analisados: idade, peso, altura sexo, EUROscore, diabete melito, fração de ejeção e artérias acometidas. Os desfechos foram compilados no intra e no pós-operatório (infarto do miocárdio, acidente vascular cerebral, disfunção renal, hemodiálise, fibrilação atrial, tempo de internação no centro de tratamento intensivo. RESULTADOS: foram incluídos 53 doentes, com 27 recebendo a monitoração. Foram excluídos 307 porque não foram operados pela mesma equipe cirúrgica. Os dois grupos foram homogêneos quanto a idade, peso e sexo, porém, a fração ejeção foi menor no grupo que recebeu o ecotransesofágico (G ETEio: 56,3%; G Não ETEio: 65,9% ± 11; p=0,01. Nos doentes em que não foi utilizado o ETEio, a mortalidade foi maior (G ETEio: 0% e G Não ETEio: 7,6%; p=0,01. Não houve diferença significativa entre os grupos quanto à incidência de acidente vascular encefálico, infarto agudo do miocárdio, fibrilação atrial aguda e lesão renal. CONCLUSÃO: a utilização do ecocardiograma transesofágico intraoperatório em pacientes submetidos à revascularização do miocárdio, com circulação extracorpórea, diminuiu a mortalidade perioperatória; orientou quanto a utilização dos fármacos inotrópicos e vasodilatadores e contribuiu para uma melhor evolução dos doentes.

O efeito da ingestão de um café com e sem canela na glicémia pós prandial em adultos saudáveis

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Fernandes, Sara Raquel Soares

2013-01-01

Dissertação para obtenção do grau de Mestre em Nutrição Clínica Introdução: A canela é uma das especiarias mais conhecidas e de uso generalizado. Estudos anteriores demonstraram que a sua ingestão reduz tanto a glicemia pós-prandial como os níveis de stress oxidativo, o que parece estar subjacente à resistência à insulina. A maioria dos estudos sobre a canela procura verificar seus efeitos em doentes diabéticos de tipo 2, mas estudos em indivíduos saudáveis são raros. Objeti...

Colonização por Staphylococcus aureus resistente à meticilina: Que impacto na morbilidade de doentes pediátricos com fibrose quística?

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Joana Fermeiro

2010-07-01

Full Text Available Resumo: Introdução: Ao Staphylococcus aureus resistente à meticilina (MRSA é classicamente reconhecido um papel patogénico no âmbito da fibrose quística (FQ.Objectivos: Avaliação da evolução da prevalência e incidência da colonização por MRSA, impacto clínico no ano após o primeiro isolamento, factores de risco e padrão de resistência antimicrobiana.Métodos: Estudo retrospectivo dos doentes pediátricos colonizados por MRSA seguidos no centro de FQ do Hospital de Santa Maria de 2003 a 2007.Resultados: O MRSA foi isolado em secreções respiratórias de 12 dos 60 doentes seguidos durante este período (colonização crónica em 3 doentes. A idade média à data do primeiro isolamento foi de 9 anos e 10 meses e o tempo médio entre o diagnóstico de FQ e a aquisição de MRSA de 5 anos e 7 meses.Verificou-se um aumento da prevalência e incidência de colonização por MRSA, com um máximo atingido em 2007 (prevalência 14,3% e incidência 8,9%. Quatro doentes cumpriram antibioticoterapia profiláctica antiestafilocócica com flucloxacilina.No ano após o primeiro isolamento de MRSA, constatou-se um aumento do número de dias de internamento em 4 doentes (2 com colonização crónica e deterioração da função pulmonar em 5, incluindo a totalidade dos doentes com colonização crónica. Apenas um doente apresentou diminuição de percentil de índice de massa corporal.As resistências mais frequentemente encontradas foram à rifampicina e à clindamicina.Conclusões: Este estudo revelou ocorrência de deterioração clínica relevante em doentes com colonização crónica por MRSA, reforçando a importância da implementação de estratégias eficazes e precoces de erradicação.Rev Port Pneumol 2010; XVI (4: 527-542 Abstract: Background: Methicillin-resistant Staphylococcus aureus (MRSA plays a well-recognised pathogenic role in cystic fibrosis (CF.Aims: To evaluate the prevalence and incidence of colonisation by MRSA

RITA (Reactivating p53 and Inducing Tumor Apoptosis) is efficient against TP53abnormal myeloma cells independently of the p53 pathway.

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Surget, Sylvanie; Descamps, Géraldine; Brosseau, Carole; Normant, Vincent; Maïga, Sophie; Gomez-Bougie, Patricia; Gouy-Colin, Nadège; Godon, Catherine; Béné, Marie C; Moreau, Philippe; Le Gouill, Steven; Amiot, Martine; Pellat-Deceunynck, Catherine

2014-06-14

The aim of this study was to evaluate the efficacy of the p53-reactivating drugs RITA and nutlin3a in killing myeloma cells. A large cohort of myeloma cell lines (n = 32) and primary cells (n = 21) was used for this study. This cohort contained cell lines with various TP53 statuses and primary cells with various incidences of deletion of chromosome 17. Apoptosis was evaluated using flow cytometry with Apo2.7 staining of the cell lines or via the loss of the myeloma-specific marker CD138 in primary cells. Apoptosis was further confirmed by the appearance of a subG1 peak and the activation of caspases 3 and 9. Activation of the p53 pathway was monitored using immunoblotting via the expression of the p53 target genes p21, Noxa, Bax and DR5. The involvement of p53 was further studied in 4 different p53-silenced cell lines. Both drugs induced the apoptosis of myeloma cells. The apoptosis that was induced by RITA was not related to the TP53 status of the cell lines or the del17p status of the primary samples (p = 0.52 and p = 0.80, respectively), and RITA did not commonly increase the expression level of p53 or p53 targets (Noxa, p21, Bax or DR5) in sensitive cells. Moreover, silencing of p53 in two TP53(mutated) cell lines failed to inhibit apoptosis that was induced by RITA, which confirmed that RITA-induced apoptosis in myeloma cells was p53 independent. In contrast, apoptosis induced by nutlin3a was directly linked to the TP53 status of the cell lines and primary samples (p RITA, in contrast to nutlin3a, effectively induced apoptosis in a subset of MM cells independently of p53. The findings and could be of interest for patients with a 17p deletion, who are resistant to current therapies.

Qualidade de Sono e Parâmetros de Dessaturação Nocturna em Doentes com Doença Pulmonar Obstrutiva Crónica e Hipoxémia entre 55-70 mmHg

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José Moutinho Dos Santos

2001-03-01

Full Text Available RESUMO: A dessaturação nocturna é um facto reconhecido em doentes com insuficiência respiratória crónica (IRC sendo sobretudo responsabilizada no seu mecanismo fisiopatológico a redução da ventilação alveolar particularmente durante o sono REM. Este fenómeno é importante em doentes com hipoxémia basal moderada (PaO2 basal entre 55-70 mmHg dada a posição particular da SaO2 na curva de dissociação de hemoglobina. Por outro lado, tem sido referido na literatura alterações da qualidade do sono em doentes com Doença Pulmonar Obstrutiva Crónica que afectam a normal estrutura do sono. O objectivo do trabalho foi avaliar de que modo a qualidade do sono poderia afectar os parâmetros de dessaturação nocturna e a sua definição como doente dessaturador.Vinte doentes (15 homens; 5 mulheres; idade X±dp - 68,2±6,1 anos com IRC estabilizada secundária a DPOC (FEV1 - 1,024±0,431 litros; 47±16,5 % do prognosticado foram submetidos a estudo poligráfico do sono em duas noites consecutivas em ar ambiente, sem medicação sedativa e sob medicação broncodilatora habitual. Na primeira noite de sono o padrão geral foi de insónia e sono fragmentado (aumento do tempo de latência ao sono e do número de “arousals” e diminuição da eficiência do sono com consequente redução do tempo em sono 3-4 e sono REM. Na segunda noite de estudo, verificou-se redução significativa do tempo de latência (72±65,5 vs. 28±31,4 minutos; p=0.008 e aumento da eficiência do sono (52±26,5 vs. 76±13.4%; p<0.0001 sem variação significativa do número de “arousals” e do tempo em sono profundo mas com aumento significativo do sono REM (6±4,8 vs. 11±6,5 %. Não se constataram diferenças significativas nos parâmetros de dessaturação nocturna nas duas noites embora se verifique grande variabilidade

Glioblastoma pediátrico: estudo clínico patológico de 12 casos com imunoistoquímica para proteína p53 Pediatric glioblastoma: a clinicopathological study of 12 cases with p53 protein immunohistochemistry

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Leonora Zozula Blind Pope

2007-12-01

Full Text Available Glioblastoma é um dos tumores primários mais letais do sistema nervoso central (SNC. Apesar dos significativos progressos, há poucas análises em crianças. Com o objetivo de avaliar localização, idade, sexo, sobrevida e imunoistoquímica para proteína p53, foram coletados casos de glioblastomas pediátricos do "Banco de Tumores do SNC de Curitiba", durante 1987-2003 e do Hospital Municipal Jesus, Rio de Janeiro, de 1970 a 1988. Doze preencheram os critérios de inclusão. A idade variou até 12 anos (média 7, sendo sete do sexo feminino e cinco do masculino. A sobrevida média foi 7,9 meses. Localizavam-se em hemisférios cerebrais (58,4%, mesencéfalo e tronco (33,3% e um no cerebelo. A imunoistoquímica demonstrou p53 positivo em 9 (75%. Em conclusão, glioblastoma tem comportamento semelhante entre crianças e adultos, sendo nestas menos freqüentes. Acomete hemisférios cerebrais com maior freqüência que estruturas infratentoriais, mostrando alta sensitividade com a imunomarcação para proteína p53, sendo nestes casos mais agressivos, com menor sobrevida.Glioblastoma is one of the most lethal central nervous system (CNS primary tumor. Although significant progress, only few analysis have been made in pediatric glioblastoma, which are less common and have worse prognosis than in adults. To evaluate gender, site, age, survival, and immunohistochemistry to p53, we selected cases of pediatric glioblastoma of "CNS Tumors Database in Curitiba", 1987-2003 and of the Hospital Municipal Jesus, Rio de Janeiro, 1970-1988. Twelve tumors were included. The age ranged from up to 12 years (median 7. There were 7 females and 5 males. The median survival was 7.9 months. Location was: cerebral hemispheres (58.4%, mesencephalon and brainstem (33.3% and one case in the cerebellum. Immunostained to p53 in 9 (75% cases. In conclusion, glioblastoma behaves similarly in children and adults. It is rare in children, affects both cerebral hemispheres more

Perfil epidemiológico das infecções bacterianas do aparelho respiratório em doentes com fibrose quística

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Sofia Quintas

2003-07-01

Full Text Available RESUMO: Com o intuito de caracterizar a evolução do perfil epidemiológico das infecções bacterianas do aparelho respiratório dos doentes com Fibrose Quística (FQ, os autores realizaram um estudo retrospectivo da prevalência e incidência das mesmas em 78 doentes com FQ seguidos no Centro Especializado de FQ da Clínica Universitária de Pediatria do Hospital de Santa Maria, Lisboa durante um período de 5 anos (1995-1999.A Pseudomonas aeruginosa foi a bactéria mais frequentemente isolada nos três primeiros anos do estudo (60-73%, sendo ultrapassada nos dois anos seguintes pelo Staphylococcus aureus. No entanto, a Pseudomonas aeruginosa constituiu sempre o principal agente de colonização crónica (44-59%, com um pico de início da mesma entre os 0 e os 5 anos (34%. Verificou-se ao longo dos 5 anos um aumento significativo da prevalência de colonização intermitente e crónica por Staphylococcus aureus (48% para 83% e 32% para 54%. A prevalência de isolamentos de Staphylococcus aureus resistente à meticilina e de Burkholderia cepacia quase que duplicou neste período. As taxas de isolamento e de colonização crónica por Alcaligenes xylosoxidans aumentaram bruscamente a partir de 1997 (de 3% e 0% em 1996 para 7% e 5% em 1997 e 10% e 7% em 1999. A colonização crónica por Haemophilus influenzae manteve uma prevalência média de 22%, apesar dum aumento dos isolamentos (de 42% para 61%. Em 55% dos doentes observou-se colonização crónica por dois ou mais agentes.Em função destes resultados são discutidos os esquemas terapêuticos e as medidas de prevenção de contágios que têm sido preconizados nos doentes com FQ do nosso centro.REV PORT PNEUMOL 2003; IX (4: 337-352 ABSTRACT: With the aim of characterizing the evolution of the epidemiological profile of respiratory bacterial infections of patients having Cystic Fibrosis (CF, the authors

Fibrose quística – Caracterização clínica de uma amostra de doentes portugueses

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Micaela Guardiano

2005-07-01

Full Text Available Resumo: Apesar dos rápidos avanços na compreensão dos determinantes moleculares da fibrose quística, esta continua a ser uma das doenças recessivas letais mais comuns na população caucasiana em todo o mundo. A realidade dos doentes portugueses continua a ser pouco conhecida, pela escassez de trabalhos publicados referentes à nossa população.Este trabalho tem como objectivos: fazer uma avaliação clínica de um grupo de doentes portugueses com fibrose quística, com 2 mutações identificadas e comparar a apresentação clínica de um grupo de doentes homozigóticos para a mutação F508del com doentes não homozigóticos para esta mutação.Para tal, seleccionou-se um grupo de doentes em seguimento na Consulta de Pneumologia Pediátrica do HSJ que foram caracterizados do ponto de vista fenotípico e classificados de acordo com critérios de gravidade.Todos os doentes desta amostra apresentaram mutações de classe I e/ou II, que se associam, classicamente, a fenótipo mais grave. Em conformidade com a gravidade genotípica, todos os doentes apresentaram um fenótipo de insuficiência pancreática mas com maior variabilidade de manifestações pulmonares.Não se encontraram variações significativas em termos de idade de diagnóstico, formas de apresentação e gravidade da doença entre doentes homozigóticos F508del e restantes doentes. Em contrapartida, doentes com o mesmo genótipo (homozigóticos F508del apresentaram diferentes espectros de manifestações clínicas e de gravidade fenotípica. Tanto ou mais do que a caracterização genotípica, o tempo de evolução da doença e os factores externos (nomeadamente a sujeição a estímulos infecciosos deverão interferir na gravidade do fenótipo num dado momento.Rev Port Pneumol 2005; XI (4: 381-406 Abstract: Even though there have been rapid advances in

The p53-dependent radioadaptive response

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Ohnishi, Takeo

We already reported that conditioning exposures at low doses, or at low dose-rates, lowered radiation-induced p53-dependent apoptosis in cultured cells in vitro and in the spleens of mice in vivo. In this study, the aim was to characterize the p53-dependent radioadaptive response at the molecular level. We used wild-type (wt) p53 and mutated (m) p53 containing cells derived from the human lung cancer H1299 cell line, which is p53-null. Cellular radiation sensitivities were determined with a colony-forming assay. The accumulation of p53, Hdm2, and iNOS was analyzed with Western blotting. The quantification of chromosomal aberrations was estimated by scoring dicentrics per cell. In wtp53 cells, it was demonstrated that the lack of p53 accumulation was coupled with the activation of Hdm2 after low dose irradiation (0.02 Gy). Although NO radicals were only minimally induced in wtp53 cells irradiated with a challenging irradiation (6 Gy) alone, NO radicals were seen to increase about 2-4 fold after challenging irradiation following a priming irradiation (0.02 Gy). Under similar irradiation conditions with a priming and challenging irradiation in wtp53 cells, induction of radioresistance and a depression of chromosomal aberrations were observed only in the absence of Pifithrin-α (a p53 inhibitor), RITA or Nutlin-3 (p53-Hdm2 interaction inhibitors), aminoguanidine (an iNOS inhibitor) and c-PTIO (an NO radical scavenger). On the other hand, in p53 dysfunctional cells, a radioadaptive response was not observed in the presence or absence of those inhibitors. Moreover, radioresistance developed when wtp53 cells were treated with ISDN (an NO generating agent) alone. These findings suggest that NO radicals are an initiator of the radioadaptive response acting through the activation of Hdm2 and the depression of p53 accumulations.

Doenças pulmonares intersticiais: Acuidade diagnóstica e riscos da biópsia pulmonar cirúrgica Interstitial lung disease: Diagnostic accuracy and safety of surgical lung biopsy

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Miguel Guerra

2009-05-01

Full Text Available Os autores descrevem a sua casuística de biópsias pulmonares cirúrgicas em doentes com doença pulmonar intersticial, de forma a determinar a acuidade diagnóstica, os riscos e a morbimortalidade associados ao procedimento. Entre Janeiro de 1998 e Dezembro de 2007, 53 doentes (idade média de 47,2±13 anos foram referenciados para a realização de biópsia pulmonar cirúrgica, dos quais 22 eram mulheres (41,5%. As biópsias pulmonares foram realizadas quer por videotoracoscopia (37 doentes, 69,8%, quer por minitoracotomia (16 doentes, 30,2%. Foi escolhido o pulmão direito para biopsar em 88,7% dos casos. Registaram-se complicações pós-operatórias em 5 doentes (9,4%: fuga aérea prolongada em 3 doentes (5,7%, persistência de loca de pneumotórax num doente (1,9% e hemorragia com necessidade de revisão de hemostase noutro doente (1,9%. Ocorreu um óbito de causa desconhecida num doente sem risco acrescido. A duração média da drenagem foi de 4,4±3 dias e o tempo de internamento médio de 5,5±4 dias. O diagnóstico histológico definitivo foi conseguido em 50 doentes, registando-se uma acuidade diagnóstica de 94,3%. Em conclusão, o potencial benefício de um diagnóstico histopatológico conclusivo através de uma biópsia pulmonar cirúrgica deve ser balanceado com os riscos associados ao procedimento cirúrgico, especialmente para aqueles doentes com disfunção cardiopulmonar severa.This study reports our experience, diagnostic accuracy and safety of surgical lung biopsy in patients with interstitial lung diseases. From January 1998 – December 2007 surgical lung biopsy was performed in 53 patients (22 female [41.5%]; age 47.2±13 years. A total of 37 patients (69.8% underwent videothoracoscopic lung biopsy and minithoracotomy was performed in 16 patients (30.2%. Right lung was the choice in 47 patients (88.7%. Postoperative complications were rare (9.4% and included three prolonged air leaks (5.7%, one pneumothorax requiring a

Fibrose quística em adultos Cystic fibrosis in adults

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C Damas

2007-05-01

Full Text Available Os autores efectuaram uma revisão de doentes adultos com fibrose quística (FQ, seguidos na consulta de Pneumologia no período de 1994-2004 (n=8: cinco mulheres e três homens, com idades compreendidas entre 20 e 34 anos (mediana = 27 anos, cuja idade de diagnóstico variou entre os 18 meses e os 31 anos. O diagnóstico foi obtido por prova de suor (positiva em seis doentes e estudo genético (homozigotia para a mutação ÄF508 em quatro doentes. O atingimento respiratório traduziu-se por sinusite e bronquiectasias, acompanhando-se o envolvimento pulmonar por alterações funcionais e também gasométricas na maioria dos doentes, ainda que de gravidade variável e não relacionada com a idade de diagnóstico. Verificou-se colonização da árvore brônquica em cinco doentes: Pseudomonas aeruginosa em quatro e Staphilococcus aureus em quatro (verificando-se colonização concomitante por estes agentes em três. As principais causas de exacerbação foram infecções respiratórias e hemoptises. Quanto ao atingimento não respiratório, quatro doentes apresentavam envolvimento digestivo (com cirrose hepática num caso, um insuficiência renal em hemodiálise, e em apenas um foi efectuado espermograma para documentação de infertilidade. Quatro doentes tinham osteopenia documentada por densitometria óssea. As medidas terapêuticas mais utilizadas foram a cinesiterapia, os broncodilatadores, a alfa-dornase, mucolíticos, suplementos vitamínicos e enzimáticos, antibioterapia e oxigenoterapia. Relativamente à evolução, uma doente abandonou a consulta, uma doente faleceu, um doente aguardava transplante pulmonar e os restantes mantiveram as suas características clínicas habituais. Neste grupo, a gravidade da doença pulmonar não se relacionou com o diagnóstico mais tardio, o que se pode dever à diversidade de apresentação fenotípica da FQ na idade adulta.The authors reviewed adult cystic fibrosis patients followed in the Pulmonology

Colonic carcinoid tumors: a clinicopathologic study of 23 patients from a single institution Tumores carcinóides do cólon: estudo clinicopatológico de 23 doentes de uma única instituição

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Daniel Reis Waisberg

2009-12-01

éia, massa abdominal palpável e sangramento pelo reto. Não foram observados doentes com síndrome carcinóide. A lesão estava localizada no ceco em 16 (69,6% doentes, no cólon sigmóide em 3 (13,0%, no colo ascendente em 3 (13,0% e no cólon transverso em 1 (4,3%. Vinte e um (91,3% doentes foram operados com intenção curativa. Disseminação da doença para o fígado e peritônio foi encontrada em dois (8,7% doentes que foram submetidos ao desvio intestinal. A média do tamanho das lesões intestinais foi 3,7 ± 1,2 cm (1,5 a 6,2 cm. Lesões múltiplas (duas ou mais ocorreram em três (13,0% casos. Nas lesões ressecadas, os linfonodos estavam comprometidos em 10 (47,6% e livres em 11 (52,4%. Invasão venosa e infiltração neural estavam ambas presentes em cinco (23,8% doentes. A neoplasia penetrava a muscularis propria em todos as lesões ressecadas. Quatro (17,4% doentes apresentaram outra neoplasia maligna primária. Três (13,0% doentes faleceram devido a complicações pós-operatórias e outros cinco (21,7% morreram devido às metástases metacrônicas ou recidiva local. Quinze doentes (65,2% permanecem vivos e sem sinais de doença ativa. A média do período de seguimento foi de 12 anos (1,2 a 18 anos, a média de tempo de sobrevivência foi de 50,7 ± 34,2 meses e o índice de sobrevivência de 5 anos foi 62.7%. CONCLUSÕES: Os tumores carcinóide do cólon localizam-se, geralmente, no cólon direito e podem ser clinicamente ocultos até que atinjam estádios avançados. Devido ao índice relativamente baixo de sobrevivência, é recomendado que, além da ressecção cirúrgica padronizada, seja realizada vigilância intensa para doença metastática, especialmente durante os 2 primeiros anos após a operação. Doentes com carcinóide do cólon necessitam de avaliação de todo o trato gastrointestinal para verificar a presença de outras neoplasias malignas primárias, além de seguimento pós-operatório por período maior de tempo, pois a recidiva após 5

RITA can induce cell death in p53-defective cells independently of p53 function via activation of JNK/SAPK and p38.

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Weilbacher, A; Gutekunst, M; Oren, M; Aulitzky, W E; van der Kuip, H

2014-07-10

Significant advances have been made in the development of small molecules blocking the p53/MDM2 interaction. The Mdm2 inhibitor Nutlin-3 is restricted to tumors carrying wtp53. In contrast, RITA, a compound that binds p53, has recently been shown also to restore transcriptional functions of mtp53. As more than 50% of solid tumors carry p53 mutations, RITA promises to be a more effective therapeutic strategy than Nutlin-3. We investigated effects of RITA on apoptosis, cell cycle and induction of 45 p53 target genes in a panel of 14 cell lines from different tumor entities with different p53 status as well as primary lymphocytes and fibroblasts. Nine cell strains expressed wtp53, four harbored mtp53, and three were characterized by the loss of p53 protein. A significant induction of cell death upon RITA was observed in 7 of 16 cell lines. The nonmalignant cells in our panel were substantially less sensitive. We found that in contrast to Nultin-3, RITA is capable to induce cell death not only in tumor cells harboring wtp53 and mtp53 but also in p53-null cells. Importantly, whereas p53 has a central role for RITA-mediated effects in wtp53 cells, neither p53 nor p63 or p73 were essential for the RITA response in mtp53 or p53-null cells in our panel demonstrating that besides the known p53-dependent action of RITA in wtp53 cells, RITA can induce cell death also independently of p53 in cells harboring defective p53. We identified an important role of both p38 and JNK/SAPK for sensitivity to RITA in these cells leading to a typical caspase- and BAX/BAK-dependent mitochondrial apoptosis. In conclusion, our data demonstrate that RITA can induce apoptosis through p38 and JNK/SAPK not only in tumor cells harboring wtp53 and mtp53 but also in p53-null cells, making RITA an interesting tumor-selective drug.

S100A4 interacts with p53 in the nucleus and promotes p53 degradation.

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Orre, L M; Panizza, E; Kaminskyy, V O; Vernet, E; Gräslund, T; Zhivotovsky, B; Lehtiö, J

2013-12-05

S100A4 is a small calcium-binding protein that is commonly overexpressed in a range of different tumor types, and it is widely accepted that S100A4 has an important role in the process of cancer metastasis. In vitro binding assays has shown that S100A4 interacts with the tumor suppressor protein p53, indicating that S100A4 may have additional roles in tumor development. In the present study, we show that endogenous S100A4 and p53 interact in complex samples, and that the interaction increases after inhibition of MDM2-dependent p53 degradation using Nutlin-3A. Further, using proximity ligation assay, we show that the interaction takes place in the cell nucleus. S100A4 knockdown experiments in two p53 wild-type cell lines, A549 and HeLa, resulted in stabilization of p53 protein, indicating that S100A4 is promoting p53 degradation. Finally, we demonstrate that S100A4 knockdown leads to p53-dependent cell cycle arrest and increased cisplatin-induced apoptosis. Thus, our data add a new layer to the oncogenic properties of S100A4 through its inhibition of p53-dependent processes.

Changes in the management of patients with severe acute pancreatitis Mudanças no manejo de doentes com pancreatite aguda grave

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Tercio De Campos

2008-09-01

Full Text Available BACKGROUND: Severe acute pancreatitis is present in up to 25% of patients with acute pancreatitis, with considerable mortality. Changes in the management of acute pancreatitis in the last 2 decades contributed to reduce the mortality. AIM: To show the evolution in the management of severe acute pancreatitis, comparing two different approaches. METHODS: All patients with severe acute pancreatitis from 1999 to 2005 were included. We compared the results of a retrospective review from 1999 to 2002 (group A with a prospective protocol, from 2003 to 2005 (group B. In group A severe pancreatitis was defined by the presence of systemic or local complications. In group B the Atlanta criteria were used to define severity. The variables analyzed were: age, gender, etiology, APACHE II, leukocytes, bicarbonate, fluid collections and necrosis on computed tomography, surgical treatment and mortality. RESULTS: Seventy-one patients were classified as severe, 24 in group A and 47 in group B. The mean APACHE II in groups A and B were 10.7 ± 3.5 and 9.3 ± 4.5, respectively. Necrosis was seen in 12 patients (50% in group A and in 21 patients (44.7% in group B. Half of the patients in group A and two (4.3% in group B underwent to pancreatic interventions. Mortality reached 45.8% in group A and 8.5% in group B. CONCLUSION: A specific approach and a prospective protocol can change the results in the treatment of patients with severe acute pancreatitis.RACIONAL: A pancreatite aguda grave está presente em até 25% dos doentes com pancreatite aguda, com mortalidade considerável. Mudanças no tratamento da pancreatite aguda nas últimas duas décadas contribuíram para a redução da mortalidade destes doentes. OBJETIVO: Mostrar a evolução do manejo da pancreatite aguda, comparando duas diferentes abordagens. MÉTODOS: Todos os doentes com pancreatite aguda grave de 1999 a 2005 do Serviço de Emergência da Santa Casa de São Paulo, SP, foram incluídos. Os

Telemonitorização domiciliária de insuficientes respiratórios crónicos graves e de doentes asmáticos

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Manuela Zamith

2009-05-01

Full Text Available Resumo: Durante nove meses avaliámos um dispositivo portátil para transferência de dados pela Internet entre doentes e profissionais de saúde: oximetria, ECG, respostas a questionários e mensagens. Foram incluídos 51 insuficientes respiratórios crónicos (IRC graves acompanhados no Hospital de Pulido Valente (Lisboa e no Hospital do Espírito Santo (Évora e 21 asmáticos deste último hospital. A utilização e a aceitação deste dispositivo foram avaliadas através de questionários que registaram a opi-nião dos doentes e dos profissionais de saúde. Nos IRC de Lisboa avaliou-se a repercussão deste programa sobre internamentos hospitalares e qualidade de vida dos doentes.Aprender a utilizar o sistema foi mais difícil para os doentes IRC; a maioria (80% teve problemas com o equipamento, qualificados como raros/ocasionais em 62% dos casos.Para 31 doentes IRC seguidos no hospital de Lisboa, a utilização do sistema foi classificada como correcta em12 doentes, incorrecta em 7 e razoável em12 doentes. Os primeiros tiveram redução do número e duração dos internamentos em relação a igual período anterior ao programa de telemonitorização e melhoria da qualidade de vida, em particular no domínio da actividade. Com este sistema de telemonitorização 80% dos doentes IRC sentiram-se mais/muito mais apoiados e 33 (75% utilizariam este sistema no futuro, se ele estivesse disponível. No grupo de doentes asmáticos, 81% gostariam de manter este tipo de vigilância. O serviço foi considerado útil pelos investigadores. Concluímos que a telemonitorização domiciliária constitui uma contribuição positiva para a gestão dos doentes crónicos e a sua divulgação deverá ser considerada no futuro.Rev Port Pneumol 2009; XV (3: 385-418 Abstract: For 9 months we evaluated a portable device to transfer patient-clinician data by

Em busca de lugares perdidos: assistência ao doente mental revelada através de histórias de vida

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Dorisdaia Carvalho de Humerez

1997-06-01

Full Text Available O trabalho em questão tem por objetivo conhecer a história de vida de doentes mentais; resgatar suas expectativas, projetos e possibilidades dentro ou fora da instituição psiquiátrica e refletir com base na experiência dos sujeitos, sobre a assistência ao doente mental. Os discursos revelaram a qualidade da vivência nos lugares antes, durante e depois do enlouquecer, sendo que, no depois, os relatos, passam a ter outro significado, mesmo quando o lugar, materialmente, é o mesmo de antes do adoecer. Os sujeitos conseguem sobreviver olhando para o passado, que na maior parte foi também de dificuldades, porém tinham o essencial: desempenhavam papéis aceitos socialmente, compartilhavam no grupo social e antecipavam-se no porvir. Os sujeitos deste estudo expõem o uso de astúcia e esperteza para driblar a ordem a que estão submetidos. Reivindicam o resgate do identitário, do relacional, querem compartilhar, de alguma forma, da vida com os outros e participar das gestões sobre seu destino. Explicitaram também que a vivência do não-lugar não é apenas no hospital psiquiátrico, mas a cultura manicomial que habita as famílias, os ambulatórios, os hospitais-dia, as universidades, as enfermarias psiquiátricas dos hospitais gerais. Desconstruir o manicômio, portanto, será rever a cultura, ou o manicômio mental. Não se trata de um processo apenas no interior da psiquiatria, mas atravessa diferentes dimensões: da política, das leis, da organização social, das instituições disciplinares, enfim, do imaginário coletivo.

Expression of p53 and p21 in primary glioblastomas

International Nuclear Information System (INIS)

Gross, M.W.; Nashwan, K.; Engenhart-Cabillic, R.; Kraus, A.; Mennel, H.D.; Schlegel, J.

2005-01-01

Background and purpose: primary glioblastomas (GBMs) are highly radioresistant, and in contrast to secondary GBMs, they bear wild-type (wt) p53 protein, which is stabilized in a proportion of these tumors. Therefore, it was investigated in vivo whether p53 expression has prognostic value in patients undergoing radiochemotherapy. Additionally, the authors tried to identify, in vitro, subgroups of primary GBM with different susceptibilities to irradiation, on the basis of their p53 and p21 responses to ionizing radiation. Material and methods: tumor tissue samples from 31 patients suffering from primary GBM undergoing a combined radiochemotherapy with topotecan were investigated. The percentage of cells expressing p53 protein was determined immunohistochemically. Additionally, primary cultures from eleven primary GBMs were established and investigated. p53 and p21 expressions were evaluated before irradiation with 10 Gy and at 2 and 8 h after irradiation. p53 protein expression was measured by western analysis and p21 mRNA expression by reverse transcription-polymerase chain reaction (RT-PCR). Results: the percentage of p53-positive cells within the tumor specimens obtained from the 31 patients ranged from 0% to 28%, the median value being 4.3%. No significant correlation with disease-free survival or overall survival was found. In vitro, p53 protein was detected in seven of eleven cultures from primary GBM. After irradiation a decrease in p53 protein expression was seen in six of the seven p53-positive cultures. Half of the cultures (two of four) without basal p53 expression showed an increase in p53 expression after irradiation. Basal overexpression of p21 was detected in six of the eleven cultures; in four out of six irradiation led to a decrease in p21 expression. In all cell lines (five of eleven) initially showing absent p21 expression, irradiation induced p21 expression. Despite these responses, G1 arrest was not detectable in any of the GBM cultures

Immunohistochemical study of p53, pRb, p16 in esophageal cancer

International Nuclear Information System (INIS)

Zo, Jae Ill; Zo, Kyung Ja; Park, Jong Ho; Kim, Mi Hee

1998-01-01

To confirm the expression of molecular genetic alterations of p53, pRb, p16 in esophageal cancer and to investigate the expression of p53, pRb, p16 in esophageal cancer according to the pathologic steps of carcinogenesis, immuno-histochemistry was performed in 15 resected esophageal cancer specimens with multiple separated lesions after pathologic mapping. The accumulation of mutant p53 was observed in 60 % of dysplasia and 47 % of invasive cancer, while pRb was not detected in 91 % of dysplasia and 72.7 % of invasive cancer. But p16 was not observed in 0 % in dysplasia and 7 % of invasive cancer. But p16 was not observed in 0 % in dysplasia and 28.6 % in invasive cancer. There was no simultaneous negative pRb and p16 expression. There was no relations between p53 and p16, pRb. As a results, the expression of p53, pRb, p16 was co-related well with molecular genetic changes and inactivation of p53, pRb, p16 was co-related well with molecular genetic changes and inactivation of p53 and pRb was common and early event in esophageal carcinogenesis in Korea, but inactivation of p16 was a infrequent change. (author). 17 refs., 2 tabs., 7 figs

Tumor protein 53-induced nuclear protein 1 (TP53INP1 enhances p53 function and represses tumorigenesis

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Jeyran eShahbazi

2013-05-01

Full Text Available Tumor protein 53-induced nuclear protein 1 (TP53INP1 is a stress-induced p53 target gene whose expression is modulated by transcription factors such as p53, p73 and E2F1. TP53INP1 gene encodes two isoforms of TP53INP1 proteins, TP53INP1α and TP53INP1β, both of which appear to be key elements in p53 function. When associated with homeodomain-interacting protein kinase-2 (HIPK2, TP53INP1 phosphorylates p53 protein at Serine 46, enhances p53 protein stability and its transcriptional activity, leading to transcriptional activation of p53 target genes such as p21, PIG-3 and MDM2, cell growth arrest and apoptosis upon DNA damage stress. The anti-proliferative and pro-apoptotic activities of TP53INP1 indicate that TP53INP1 has an important role in cellular homeostasis and DNA damage response. Deficiency in TP53INP1 expression results in increased tumorigenesis; while TP53INP1 expression is repressed during early stages of cancer by factors such as miR-155. This review aims to summarize the roles of TP53INP1 in blocking tumor progression through p53-dependant and p53-independent pathways, as well as the elements which repress TP53INP1 expression, hence highlighting its potential as a therapeutic target in cancer treatment.

The malarial impact on the nutritional status of Amazonian adult subjects Impacto da malaria no estado nutricional de doentes adultos da Amazônia

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Paulo C. M. Pereira

1995-02-01

, sem história de malária; G2 - controle (n = 40, com história de malária, mas sem manifestação de doença atual; G3 - doentes com Plasmodium vivax (n = 19 e G4 - doentes com Plasmodium faleiparum (n = 31. O diagnóstico de malária foi estabelecido por manifestações clínicas e confirmado laboratorialmente (gota espessa e esfregaço. No global as medidas antropométricas e bioquímicas discriminaram os grupos diferentemente. As medidas antropométricas do pêso, altura, reservas calóricas e estoque proteicos somáticos, apresentaram pouca sensibilidade, discriminado apenas os grupos extremos (Gl > G4. As medidas bioquímicas, no geral diferenciaram dois grandes grupos, os sadios e os doentes (G1+G2 e (G3+G4. Os doentes com Plasmodium falciparum (G4 foram os que se apresentaram em pior estado nutricional para a maioria das variáveis, sem entretanto, nenhuma variável individual que os discriminasse significativamente do G3. Estes dados permitem concluir que a malária resulta em desnutrição do hospedeiro, cuja gravidade está relacionada ao tipo e estágio da doença.

Human neuroblastoma cells with acquired resistance to the p53 activator RITA retain functional p53 and sensitivity to other p53 activating agents.

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Michaelis, M; Rothweiler, F; Agha, B; Barth, S; Voges, Y; Löschmann, N; von Deimling, A; Breitling, R; Doerr, H Wilhelm; Rödel, F; Speidel, D; Cinatl, J

2012-04-05

Adaptation of wild-type p53 expressing UKF-NB-3 cancer cells to the murine double minute 2 inhibitor nutlin-3 causes de novo p53 mutations at high frequency (13/20) and multi-drug resistance. Here, we show that the same cells respond very differently when adapted to RITA, a drug that, like nutlin-3, also disrupts the p53/Mdm2 interaction. All of the 11 UKF-NB-3 sub-lines adapted to RITA that we established retained functional wild-type p53 although RITA induced a substantial p53 response. Moreover, all RITA-adapted cell lines remained sensitive to nutlin-3, whereas only five out of 10 nutlin-3-adapted cell lines retained their sensitivity to RITA. In addition, repeated adaptation of the RITA-adapted sub-line UKF-NB-3(r)RITA(10 μM) to nutlin-3 resulted in p53 mutations. The RITA-adapted UKF-NB-3 sub-lines displayed no or less pronounced resistance to vincristine, cisplatin, and irradiation than nutlin-3-adapted UKF-NB-3 sub-lines. Furthermore, adaptation to RITA was associated with fewer changes at the expression level of antiapoptotic factors than observed with adaptation to nutlin-3. Transcriptomic analyses indicated the RITA-adapted sub-lines to be more similar at the gene expression level to the parental UKF-NB-3 cells than nutlin-3-adapted UKF-NB-3 sub-lines, which correlates with the observed chemotherapy and irradiation sensitivity phenotypes. In conclusion, RITA-adapted cells retain functional p53, remain sensitive to nutlin-3, and display a less pronounced resistance phenotype than nutlin-3-adapted cells.

p53 Over-expression and p53 mutations in colon carcinomas: Relation to dietary risk factors

NARCIS (Netherlands)

Voskuil, D.W.; Kampman, E.; Kraats, A.A. van; Balder, H.F.; Muijen, G.N.P. van; Goldbohm, R.A.; Veer, P. van 't

1999-01-01

Epidemiological studies have suggested that dietary factors may differently affect p53-dependent and p53-independent pathways to colon cancer. Results of such studies may depend on the method used to assess p53 status. This case-control study of 185 colon-cancer cases and 259 controls examines this

Regulation of autophagy by cytoplasmic p53.

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Tasdemir, Ezgi; Maiuri, M Chiara; Galluzzi, Lorenzo; Vitale, Ilio; Djavaheri-Mergny, Mojgan; D'Amelio, Marcello; Criollo, Alfredo; Morselli, Eugenia; Zhu, Changlian; Harper, Francis; Nannmark, Ulf; Samara, Chrysanthi; Pinton, Paolo; Vicencio, José Miguel; Carnuccio, Rosa; Moll, Ute M; Madeo, Frank; Paterlini-Brechot, Patrizia; Rizzuto, Rosario; Szabadkai, Gyorgy; Pierron, Gérard; Blomgren, Klas; Tavernarakis, Nektarios; Codogno, Patrice; Cecconi, Francesco; Kroemer, Guido

2008-06-01

Multiple cellular stressors, including activation of the tumour suppressor p53, can stimulate autophagy. Here we show that deletion, depletion or inhibition of p53 can induce autophagy in human, mouse and nematode cells subjected to knockout, knockdown or pharmacological inhibition of p53. Enhanced autophagy improved the survival of p53-deficient cancer cells under conditions of hypoxia and nutrient depletion, allowing them to maintain high ATP levels. Inhibition of p53 led to autophagy in enucleated cells, and cytoplasmic, not nuclear, p53 was able to repress the enhanced autophagy of p53(-/-) cells. Many different inducers of autophagy (for example, starvation, rapamycin and toxins affecting the endoplasmic reticulum) stimulated proteasome-mediated degradation of p53 through a pathway relying on the E3 ubiquitin ligase HDM2. Inhibition of p53 degradation prevented the activation of autophagy in several cell lines, in response to several distinct stimuli. These results provide evidence of a key signalling pathway that links autophagy to the cancer-associated dysregulation of p53.

SV40 large T-p53 complex: evidence for the presence of two immunologically distinct forms of p53

International Nuclear Information System (INIS)

Milner, J.; Gamble, J.

1985-01-01

The transforming protein of SV40 is the large T antigen. Large T binds a cellular protein, p53, which is potentially oncogenic by virtue of its functional involvement in the control of cell proliferation. This raises the possibility that p53 may mediate, in part, the transforming function of SV40 large T. Two immunologically distinct forms of p53 have been identified in normal cells: the forms are cell-cycle dependent, one being restricted to nondividing cells (p53-Go) and the second to dividing cells (p53-G divided by). The authors have now dissociated and probed the multimeric complex of SV40 large T-p53 for the presence of immunologically distinct forms of p53. Here they present evidence for the presence of p53-Go and p53-G divided by complexed with SV40 large T

Fístula pancreática após duodenopancreatectomia: correlação dos aspectos intra-operatórios e histologicos do pâncreas

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Fernando Leal Pereira

Full Text Available OBJETIVO: Avaliar a relação entre a ocorrência de fístula pancreática pós-anastomose pancreatojejunal, em doentes submetidos à duodenopancreatectomia por neoplasia maligna periampolar, com aspectos histológicos de fibrose e inflamação encontrados no tecido pancreático e com o calibre do ducto pancreático principal. MÉTODOS: Estudo retrospectivo interessando doentes que foram submetidos ao tratamento com ressecção cirúrgica. Verificou-se o índice de fístulas pancreáticas encontradas. Classificou-se de acordo com a histologia da fibrose e da inflamação pancreática. RESULTADOS: Identificaram-se 77 doentes, com média de idade de 57,6 anos, sendo 62,4% do sexo masculino. De acordo com o tipo de operação realizada, 66,3% constituíram-se em gastroduodenopancreatectomia e 33,7% em duodenopancreatectomia com preservação do piloro. Em relação ao número de fístulas diagnosticadas, identificou-se que 23,4% doentes apresentaram tal complicação pós-operatória, sendo que em 66,7% a causa era neoplasia de papila. Achados macroscópicos intraoperatórios, identificou-se classificação da textura pancreática, tida como normal, em 85,8% e, quanto ao calibre do ducto principal pancreático, foi encontrada média de 4,9mm. Houve relação importante entre a consistência endurecida do coto pancreático e a ausência da fístula. Nos doentes com tecido normal ou amolecido, o índice de fístula foi 25,4%. Quanto ao diâmetro ductal, identificou-se (p <0,05 maior número de deiscências da anastomose pancreática na ausência de dilatação ductal. Evidenciou-se que doentes com valores médios do diâmetro de ducto de 5,4mm (76,7% não mostraram esta complicação. CONCLUSÃO: A presença de fibrose e de dilatação ductal habitualmente coexistem e estão relacionadas à menor porcentagem de fístulas enteropancreáticas.

Linfopenia em doentes submetidos a ventilação mecânica por exacerbação de insuficiência respiratória crónica: estudo prospectivo

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Paulo Marcelino

2004-09-01

Full Text Available RESUMO: Objectivo: avaliar e caracterizar a linfopenia em doentes admitidos numa unidade de cuidados intensivos para suporte ventilatório por exacerbação de insuficiência respiratória crónica e eventual relação com a gravidade da doença.Material e métodos: estudo prospectivo com 6 meses de duração e mais 6 meses de seguimento após alta da unidade. Incluídos 24 doentes, 22 homens, com APACHE II médio de 19,7, 3 dos quais com possibilidade de seguimento após a alta. Foram colhidas análises para determinação das subpopulações linfocitárias na admissão e a cada 7 dias de ventilação mecânica. Excluídos doentes com sinais de infecção ou imunossupressão prévia, à excepção dos corticóides.Resultados: a linfopenia foi encontrada em 79,2 % dos doentes com depleção de todas as subpopulações linfocitárias sendo mais expressiva a depleção de linfócitos B CD19+. Esta linfopenia não se relacionou com os níveis séricos de cortisol, e apesar de se relacionar com uma maior gravidade clínica não esteve associada a uma maior mortalidade. O registo evolutivo no internamento mostrou tendencialmente uma recuperação da linfopenia.Conclusões: a linfopenia é frequente em doentes ventilados por exacerbação de doença respiratória crónica. Trata-se de uma linfopenia não selectiva, que recupera ao longo do internamento, mais acentuada ao nível dos linfócitos B CD19+. Estes doentes apresentam indices de gravidade maior mas sem diferenças na mortalidade. O seguimento ambulatório destes doentes mostrou-se difícil e foi inconclusivo.REV PORT PNEUMOL 2004; X (5: 373-381 ABSTRACT: Objectives: Evaluate and characterize lymphopenia in patients admitted to the Intensive Care Unit (ICU for mechanical ventilation due to aggravated chronic respiratory failure and its probable relation to severity

Fibrose quística em adultos

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C. Damas

2007-05-01

Full Text Available Resumo: Os autores efectuaram uma revisão de doentes adultos com fibrose quística (FQ, seguidos na consulta de Pneumologia no período de 1994-2004 (n=8: cinco mulheres e três homens, com idades compreendidas entre 20 e 34 anos (mediana=27 anos, cuja idade de diagnóstico variou entre os 18 meses e os 31 anos. O diagnóstico foi obtido por prova de suor (positiva em seis doentes e estudo genético (homozigotia para a mutação ΔF508 em quatro doentes. O atingimento respiratório traduziu-se por sinusite e bronquiectasias, acompanhando-se o envolvimento pulmonar por alterações funcionais e também gaso-métricas na maioria dos doentes, ainda que de gravidade variável e não relacionada com a idade de diagnóstico. Verificou-se colonização da árvore brônquica em cinco doentes: Pseudomonas aeruginosa em quatro e Staphilococcus aureus em quatro (verificando-se coloni-zação concomitante por estes agentes em três. As principais causas de exacerbação foram infecções res-piratórias e hemoptises. Quanto ao atingimento não respiratório, quatro doentes apresentavam envolvimento digestivo (com cirrose hepática num caso, um insuficiência renal em hemo-diálise, e em apenas um foi efectuado espermograma para documentação de infertilidade. Quatro doentes tinham osteopenia documentada por densitometria óssea. As medidas terapêuticas mais utilizadas foram a cine-siterapia, os broncodilatadores, a alfa-dornase, muco-líticos, suplementos vitamínicos e enzimáticos, antibio-terapia e oxigenoterapia. Relativamente à evolução, uma doente abandonou a consulta, uma doente faleceu, um doente aguardava transplante pulmonar e os restantes mantiveram as suas características clínicas habituais. Neste grupo, a gravidade da doença pulmonar não se relacionou com o diagnóstico mais tardio, o que se pode dever à diversidade de apresenta

Restoration of mp53 to wtp53 by chemical chaperones restores p53-dependent apoptosis after radiotherapy

International Nuclear Information System (INIS)

Ohnishi, T.; Asakawa, I.; Tamamoto, T.; Takahashi, A.; Ohnishi, K.

2003-01-01

The mutations of many kinds of cancer related genes have been investigated for the predictive assay against cancer therapy by the application of molecular biology. A tumor suppressor gene product of wtp53 plays important roles in cancer suppression through the induction of cell growth arrest, DNA repair or apoptosis. The p53 exerts its function by induction of downstream genes and/or interaction to various proteins. Mutations in the p53 gene (mp53) cause conformational alterations in the p53 protein, the majority of which can no longer induce expression of the downstream genes. The genetic status of p53 gene has been focused as the most important candidate among them for cancer therapy. The gene therapy of p53 has been already applied. We reported that the transfection of mp53 gene increased the radio-, thermo- and chemo-resistance, and depressed apoptosis introduced with them through bax-induction and proteolysis of PARP and caspase-3. From these results, we propose that the gene therapy of wtp53 to p53-deleted cancer cells may be very useful for cancer therapy by the combination with radiotherapy. Even in the case of mp53 cancer cells, we succeeded the restoration of mp53 to wtp53 by glycerol or C-terminal peptide of p53 as chemical chaperones. These experimental progresses might support effective cancer therapy against individual patients bearing with different p53 gene status by the use of the most suitable treatment to them in the near future

Resposta dos volumes pulmonares ao salbutamol inalado numa grande população de doentes com hiperinsuflação grave

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M.F. Newton

2002-09-01

Full Text Available RESUMO: A avaliação da eficácia dos broncodilatadores inalados é feita habitualmente pela medição do volume expiratório máximo no primeiro segundo (FEV1 antes e após a administração destes fármacos. Outras medições da função pulmonar, como os volumes pulmonares, não são avaliadas por rotina na maior parte dos laboratórios. Contudo, a compreensão dos efeitos dos broncodilatadores sobre os volumes pulmonares é importante, já que a hiperinsuflação pulmonar é responsável em grande parte por um excessivo trabalho respiratório e pelo aumento da dispneia observados nos doentes com doença pulmonar obstrutiva.Os autores começam por apontar o FEV1 como um marcador que pode ser pouco sensível à resposta aos broncodilatadores e dão como exemplos de parâmetros mais sensíveis a capacidade inspiratória e a avaliação das curvas débito-volume parciais. Salientam a vantagem da capacidade inspiratória relativamente ao FEV1, como factor preditivo da melhoria da tolerância ao exercício e da dispneia.No presente estudo, os autores avaliam os padrões de resposta dos volumes pulmonares – capacidade residual funcional (FRC, volume residual (RV, capacidade vital forçada (FVC e capacidade inspiratória (IC – aos broncodilatadores inalados em doentes com hiperinsuflação pulmonar moderada e grave devida primariamente à doença pulmonar obstrutiva crónica (DPOC.Realizaram um estudo retrospectivo que envolveu 957 doentes (534 homens, 423 mulheres; idade: 64,7±0,37 anos, sendo 281 gravemente hiperinsuflados (TLC > 133% do teórico, FEV1 /FVC% < 85% do teórico e os restantes 676 moderadamente hiperinsuflados (TLC entre 115% e 133% do teórico, FEV1 / FVC% < 85% do teórico.Em todos os doentes foi realizado um estudo funcional respiratório completo antes e após a administração de 200 ¼ g de

Sofrimento do doente oncológico em situação paliativa El sufrimiento de pacientes con cáncer en situación paliativa Suffering of cancer patients in a palliative situation

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Márcia Lúcia Sousa Dias Alves

2012-12-01

Full Text Available Contexto: o aumento da incidência do número de doentes crónicos da população portuguesa tornou-se um fenómeno preocupante com repercussões sociais, económicas e de saúde, estes doentes apresentam níveis de sofrimento variáveis. Este foco representa uma área de intervenção importante nos cuidados de enfermagem à pessoa em situação paliativa quer na perspetiva da sua prevenção quer no seu alívio. Objetivo: analisar a perceção do doente oncológico em situação paliativa quanto ao sofrimento e às suas várias dimensões. Metodologia: desenhou-se um estudo descritivo-correlacional com dimensão transversal. Aplicou-se o Inventário de Experiências Subjetivas de Sofrimento na Doença a 38 doentes em situação paliativa, internados num serviço de cirurgia e hemato-oncologia e que tivessem mais de 18 anos. Resultados: os doentes evidenciaram níveis intermédios de sofrimento global e observou-se a existência de correlação significativa entre a idade e a dimensão do sofrimento sócio relacional. Conclusão: pensamos ter contribuído para alicerçar de uma forma estruturada a importância desta área de intervenção do enfermeiro à pessoa em situação paliativa e desenvolver intervenções ao nível da prevenção e alívio do sofrimento destes doentes.Contexto: el aumento de la incidencia del número de enfermos crónicos de la población portuguesa se ha convertido en un fenómeno preocupante con consecuencias sociales, económicas y, cuyos pacientes presentan niveles variables de sufrimiento. Este enfoque representa un área de intervención importante para los cuidados de enfermería a la persona en situación paliativa bien desde la perspectiva de su prevención, bien en su alivio. Objetivos: analizar la percepción del paciente con cáncer en situación paliativa con respecto al sufrimiento y a sus diversas dimensiones. Metodología: se diseñó un estudio descritivo-correlacional con una dimensión transversal

P53 family members modulate the expression of PRODH, but not PRODH2, via intronic p53 response elements.

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Ivan Raimondi

Full Text Available The tumor suppressor p53 was previously shown to markedly up-regulate the expression of the PRODH gene, encoding the proline dehydrogenase (PRODH enzyme, which catalyzes the first step in proline degradation. Also PRODH2, which degrades 4-hydroxy-L-proline, a product of protein (e.g. collagen catabolism, was recently described as a p53 target. Here, we confirmed p53-dependent induction of endogenous PRODH in response to genotoxic damage in cell lines of different histological origin. We established that over-expression of TAp73β or TAp63β is sufficient to induce PRODH expression in p53-null cells and that PRODH expression parallels the modulation of endogenous p73 by genotoxic drugs in several cell lines. The p53, p63, and p73-dependent transcriptional activation was linked to specific intronic response elements (REs, among those predicted by bioinformatics tools and experimentally validated by a yeast-based transactivation assay. p53 occupancy measurements were validated in HCT116 and MCF7 human cell lines. Conversely, PRODH2 was not responsive to p63 nor p73 and, at best, could be considered a weak p53 target. In fact, minimal levels of PRODH2 transcript induction by genotoxic stress was observed exclusively in one of four p53 wild-type cell lines tested. Consistently, all predicted p53 REs in PRODH2 were poor matches to the p53 RE consensus and showed very weak responsiveness, only to p53, in the functional assay. Taken together, our results highlight that PRODH, but not PRODH2, expression is under the control of p53 family members, specifically p53 and p73. This supports a deeper link between proteins of the p53-family and metabolic pathways, as PRODH modulates the balance of proline and glutamate levels and those of their derivative alpha-keto-glutarate (α-KG under normal and pathological (tumor conditions.

Screening of medicinal plant phytochemicals as natural antagonists of p53-MDM2 interaction to reactivate p53 functioning.

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Riaz, Muhammad; Ashfaq, Usman A; Qasim, Muhammad; Yasmeen, Erum; Ul Qamar, Muhammad T; Anwar, Farooq

2017-10-01

In most types of cancer, overexpression of murine double minute 2 (MDM2) often leads to inactivation of p53. The crystal structure of MDM2, with a 109-residue amino-terminal domain, reveals that MDM2 has a core hydrophobic region to which p53 binds as an amphipathic α helix. The interface depends on the steric complementarity between MDM2 and the hydrophobic region of p53. Especially, on p53's triad, amino acids Phe19, Trp23 and Leu26 bind to the MDM2 core. Results from studies suggest that the structural motif of both p53 and MDM2 can be attributed to similarities in the amphipathic α helix. Thus, in the current investigation it is hypothesized that the similarity in the structural motif might be the cause of p53 inactivation by MDM2. Hence, molecular docking and phytochemical screening approaches are appraised to inhibit the hydrophobic cleft of MDM2 and to stop p53-MDM2 interaction, resulting in reactivation of p53 activity. For this purpose, a library of 2295 phytochemicals were screened against p53-MDM2 to find potential candidates. Of these, four phytochemicals including epigallocatechin gallate, alvaradoin M, alvaradoin E and nordihydroguaiaretic acid were found to be potential inhibitors of p53-MDM2 interaction. The screened phytochemicals, derived from natural extracts, may have negligible side effects and can be explored as potent antagonists of p53-MDM2 interactions, resulting in reactivation of the normal transcription of p53.

Interplay between PTB and miR-1285 at the p53 3'UTR modulates the levels of p53 and its isoform Δ40p53α.

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Katoch, Aanchal; George, Biju; Iyyappan, Amrutha; Khan, Debjit; Das, Saumitra

2017-09-29

p53 and its translational isoform Δ40p53 are involved in many important cellular functions like cell cycle, cell proliferation, differentiation and metabolism. Expression of both the isoforms can be regulated at different steps. In this study, we explored the role of 3'UTR in regulating the expression of these two translational isoforms. We report that the trans acting factor, Polypyrimidine Tract Binding protein (PTB), also interacts specifically with 3'UTR of p53 mRNA and positively regulates expression of p53 isoforms. Our results suggest that there is interplay between miRNAs and PTB at the 3'UTR under normal and stress conditions like DNA damage. Interestingly, PTB showed some overlapping binding regions in the p53 3'UTR with miR-1285. In fact, knockdown of miR-1285 as well as expression of p53 3'UTR with mutated miR-1285 binding sites resulted in enhanced association of PTB with the 3'UTR, which provides mechanistic insights of this interplay. Taken together, the results provide a plausible molecular basis of how the interplay between miRNAs and the PTB protein at the 3'UTR can play pivotal role in fine tuning the expression of the two p53 isoforms. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

DRAGO (KIAA0247), a new DNA damage-responsive, p53-inducible gene that cooperates with p53 as oncosuppressor. [Corrected].

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Polato, Federica; Rusconi, Paolo; Zangrossi, Stefano; Morelli, Federica; Boeri, Mattia; Musi, Alberto; Marchini, Sergio; Castiglioni, Vittoria; Scanziani, Eugenio; Torri, Valter; Broggini, Massimo

2014-04-01

p53 influences genomic stability, apoptosis, autophagy, response to stress, and DNA damage. New p53-target genes could elucidate mechanisms through which p53 controls cell integrity and response to damage. DRAGO (drug-activated gene overexpressed, KIAA0247) was characterized by bioinformatics methods as well as by real-time polymerase chain reaction, chromatin immunoprecipitation and luciferase assays, time-lapse microscopy, and cell viability assays. Transgenic mice (94 p53(-/-) and 107 p53(+/-) mice on a C57BL/6J background) were used to assess DRAGO activity in vivo. Survival analyses were performed using Kaplan-Meier curves and the Mantel-Haenszel test. All statistical tests were two-sided. We identified DRAGO as a new p53-responsive gene induced upon treatment with DNA-damaging agents. DRAGO is highly conserved, and its ectopic overexpression resulted in growth suppression and cell death. DRAGO(-/-) mice are viable without macroscopic alterations. However, in p53(-/-) or p53(+/-) mice, the deletion of both DRAGO alleles statistically significantly accelerated tumor development and shortened lifespan compared with p53(-/-) or p53(+/-) mice bearing wild-type DRAGO alleles (p53(-/-), DRAGO(-/-) mice: hazard ratio [HR] = 3.25, 95% confidence interval [CI] = 1.7 to 6.1, P < .001; p53(+/-), DRAGO(-/-) mice: HR = 2.35, 95% CI = 1.3 to 4.0, P < .001; both groups compared with DRAGO(+/+) counterparts). DRAGO mRNA levels were statistically significantly reduced in advanced-stage, compared with early-stage, ovarian tumors, but no mutations were found in several human tumors. We show that DRAGO expression is regulated both at transcriptional-through p53 (and p73) and methylation-dependent control-and post-transcriptional levels by miRNAs. DRAGO represents a new p53-dependent gene highly regulated in human cells and whose expression cooperates with p53 in tumor suppressor functions.

Prevalência e caracterização clínica dos doentes com insuficiência respiratória parcial grave internados numa UCI

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Alexandra Borba

2008-05-01

Full Text Available Resumo: Objectivos: A insuficiência respiratória parcial aguda (IRPA grave é uma situação comum na prática dos cuidados intensivos, mas os estudos existentes são insuficientes. Com este trabalho pretendeu-se estudar a prevalência e caracterizar clinicamente a população de doentes internados numa UCI que apresentam insuficiência respiratória parcial aguda grave.Material e métodos: Numa unidade de cuidados intensivos médico-cirúrgica avaliaram-se retrospectiva-mente os doentes internados durante o ano de 2004.Resultados: 37,6% dos doentes apresentaram IRPA grave. A análise estatística demonstrou que estes doentes diferiam dos doentes sem IRPA nos tempos de internamento e ventilação, índices de gravidade e mortalidade.Conclusão: A IRPA é uma situação com elevada prevalência e relevância em cuidados intensivos, mas as carac-terísticas destes doentes estão mal definidas, em parte devido à ausência de critérios claros na sua definição. Para melhor compreender este fenómeno são necessá-rios mais estudos, prospectivos e multicêntricos.Rev Port Pneumol 2008; XIV (3: 339-352 Abstract: Objective: The authors analysed patients with severe partial respiratory failure (SPRF admitted to a general Intensive Care Unit (ICU. The prevalence and clinical characteristics of these patients were evaluated.This work aims to study the rate of and to clinically characterise the patient population admitted to an Intensive Care Unit with acute severe partial respiratory failure.Material and methods: In 16-bed ICU of a central Hospital in Lisbon, patients admitted in the year 2004 were analysed. Patients with SPRF were recruited form patients with an ICU stay>24 hours. They were selected according to PaO2 and FiO2 and clinically characterized.Results: During the study period 472 patients were admitted, and 378 presented an ICU stay>24 hours and were enrolled. From those, 142 (37.6% met criteria for SPRF. Of these, 45 (31.7% a pulmonary

The novel fusion proteins, GnRH-p53 and GnRHIII-p53, expression and their anti-tumor effect.

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Peiyuan Jia

Full Text Available p53, one of the most well studied tumor suppressor factor, is responsible to a variety of damage owing to the induction of apoptosis and cell cycle arrest in the tumor cells. More than 50% of human tumors contain mutation or deletion of p53. Gonadotrophin-releasing hormone (GnRH, as the ligand of Gonadotrophin-releasing hormone receptor (GnRH-R, was used to deliver p53 into tumor cells. The p53 fusion proteins GnRH-p53 and GnRH iii-p53 were expressed and their targeted anti-tumor effects were determined. GnRH mediates its fusion proteins transformation into cancer cells. The intracellular delivery of p53 fusion proteins exerted the inhibition of the growth of H1299 cells in vitro and the reduction of tumor volume in vivo. Their anti-tumor effect was functioned by the apoptosis and cell cycle arrest induced by p53. Hence, the fusion protein could be a novel protein drug for anti-tumor therapy.

p53 mutations promote proteasomal activity.

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Oren, Moshe; Kotler, Eran

2016-07-27

p53 mutations occur very frequently in human cancer. Besides abrogating the tumour suppressive functions of wild-type p53, many of those mutations also acquire oncogenic gain-of-function activities. Augmentation of proteasome activity is now reported as a common gain-of-function mechanism shared by different p53 mutants, which promotes cancer resistance to proteasome inhibitors.

Doenças pulmonares intersticiais: Acuidade diagnóstica e riscos da biópsia pulmonar cirúrgica

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Miguel Guerra

2009-05-01

Full Text Available Resumo: Os autores descrevem a sua casuística de biópsias pulmonares cirúrgicas em doentes com doença pulmonar intersticial, de forma a determinar a acuidade diagnóstica, os riscos e a morbimortalidade associados ao procedimento. Entre Janeiro de 1998 e De-zembro de 2007, 53 doentes (idade média de 47,2±13 anos foram referenciados para a realização de biópsia pulmonar cirúrgica, dos quais 22 eram mulheres (41,5%. As biópsias pulmonares foram realizadas quer por videotoracoscopia (37 doentes, 69,8%, quer por minitoracotomia (16 doentes, 30,2%. Foi escolhido o pulmão direito para biopsar em 88,7% dos casos. Registaram-se complicações pós-operatórias em 5 doentes (9,4%: fuga aérea prolongada em 3 doentes (5,7%, persistência de loca de pneumotórax num doente (1,9% e hemorragia com necessidade de revisão de hemostase noutro doente (1,9%. Ocor-reu um óbito de causa desconhecida num doente sem risco acrescido. A duração média da drenagem foi de 4,4±3 dias e o tempo de internamento médio de 5,5±4 dias. O diagnóstico histológico definitivo foi conseguido em 50 doentes, registando-se uma acuidade diagnóstica de 94,3%. Em conclusão, o potencial benefício de um diagnóstico histopatológico conclusivo através de uma biópsia pulmonar cirúrgica deve ser balanceado com os riscos associados ao procedimento cirúrgico, especialmente para aqueles doentes com disfunção cardiopulmonar severa.Rev Port Pneumol 2009; XV (3: 433-442 Abstract: This study reports our experience, diagnostic accuracy and safety of surgical lung biopsy in patients with interstitial lung diseases. From January 1998 – December 2007 surgical lung biopsy was performed in 53 patients (22 female [41.5%]; age 47.2±13 years. A total of 37 patients (69.8% underwent videothoracoscopic lung biopsy and minithoracotomy was performed in 16 patients (30.2%. Right lung was the

Interstitial lung disease: Diagnostic accuracy and safety of surgical lung biopsy

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Miguel Guerra

2009-05-01

Full Text Available This study reports our experience, diagnostic accuracy and safety of surgical lung biopsy in patients with interstitial lung diseases. From January 1998 – December 2007 surgical lung biopsy was performed in 53 patients (22 female [41.5%]; age 47.2 ± 13 years. A total of 37 patients (69.8% underwent videothoracoscopic lung biopsy and minithoracotomy was performed in 16 patients (30.2%. Right lung was the choice in 47 patients (88.7%. Postoperative complications were rare (9.4% and included three prolonged air leaks (5.7%, one pneumothorax re-quiring a chest drain (1.9%, and one haemothorax requiring reoperation (1.9%. One patient died of cardiac arrest of unknown cause. Average chest tube duration was 4.4 ± 3 days and average hospital stay 5.4 ± 4 days. Lung biopsy contributed to the diagnosis in 50 patients (94.3%. In conclusion, the potential benefits of diagnostic surgical lung biopsy must be considered against the risks of the procedure especially in patients with severe cardiopulmonary dysfunction. Resumo: Os autores descrevem a sua casuística de biópsias pulmonares cirúrgicas em doentes com doença pulmonar intersticial, de forma a determinar a acuidade diagnóstica, os riscos e a morbimortalidade associados ao procedimento. Entre Janeiro de 1998 e Dezembro de 2007, 53 doentes (idade média de 47,2 ± 13 anos foram referenciados para a realização de biópsia pulmonar cirúrgica, dos quais 22 eram mulheres (41,5%. As biópsias pulmonares foram realizadas quer por videotoracoscopia (37 doentes, 69,8%, quer por minitoracotomia (16 doentes, 30,2%. Foi escolhido o pulmão direito para biopsar em 88,7% dos casos. Registaram-se complicações pós-operatórias em 5 doentes (9,4%: fuga aérea prolongada em 3 doentes (5,7%, persistência de loca de pneumotórax num doente (1,9% e hemorragia com necessidade de revisão de hemostase noutro doente (1,9%. Ocorreu um �

Tuberculose multirresistente – um problema ignorado em Portugal

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H. Peres

1996-11-01

Full Text Available RESUMO: O número crescente do doentes seropositivos (HIV+ com tuberculose, a forte suspeita clínica de resistências à terapêutica antibacilar e a alta taxa de mortalidade destes doentes, levaram a que o Serviço de Patologia Clínica do Hospital de Curry Cabral iniciasse em 1995 o estudo sistemático da fármaco-resistência das estirpes de Mycobacterium tuberculosis isolado em doentes seropositivos. Posteriormeote o estudo foi alargado a todos os doentos em que o bacilo da tuberculose foi isolado, incluindo doentes provenients de outros hospitals, sobretudo da área de Lisboa. Pretendeu-se avaliar a incidência de Tuberculose multirresistente particularmente em doentes seropositivos, conhecer os padrões de resistênocia mais frequentes e alertar para a necessidade urgente de medidas adequadas para o seu control, com especial ênfase para a transmissão nosocomial. SUMMARY: In 1995 the Microbiology Department of Hospital de Curry Cabral started systematic drug susceptibility testing of M. tuberculosis strains isolated in HIV seropositive patients, due to the increasing number of HIV associated tuberculosis, the clinical suspicion of drug resistance and the high mortality rate. Subsequently, the study included every patient with tuberculosis from this hospital and a few patients from other hospitals in Lisbon. The purpose of this study was to know the incidence of multidrug- resistant tuberculosis in HIV patients, the patterns of drug resistance and emphasize the urgent need for approprite infection control measures to prevent spread of MDR-tb. Palavras-chave: Mycobacterium tuberculosis, Tuberculose multliresistente, SIDA, Tuberculose nosocomial, Key-words: Mycobacterium tuberculosis, Mutidrug-resistant tuberculosis, MDR-TB, AIDS, Nocomial tuberculosis

Targeting the p53 Pathway in Ewing Sarcoma

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Neilsen, Paul M.; Pishas, Kathleen I.; Callen, David F.; Thomas, David M.

2011-01-01

The p53 tumour suppressor plays a pivotal role in the prevention of oncogenic transformation. Cancers frequently evade the potent antitumour surveillance mechanisms of p53 through mutation of the TP53 gene, with approximately 50% of all human malignancies expressing dysfunctional, mutated p53 proteins. Interestingly, genetic lesions in the TP53 gene are only observed in 10% of Ewing Sarcomas, with the majority of these sarcomas expressing a functional wild-type p53. In addition, the p53 downstream signaling pathways and DNA-damage cell cycle checkpoints remain functionally intact in these sarcomas. This paper summarizes recent insights into the functional capabilities and regulation of p53 in Ewing Sarcoma, with a particular focus on the cross-talk between p53 and the EWS-FLI1 gene rearrangement frequently associated with this disease. The development of several activators of p53 is discussed, with recent evidence demonstrating the potential of small molecule p53 activators as a promising systemic therapeutic approach for the treatment of Ewing Sarcomas with wild-type p53. PMID:21197471

Enhancement of radiosensitivity of recombinant Ad-p53 gene on human lung adenocarcinoma cell with different p53 status

International Nuclear Information System (INIS)

Pang Dequan; Wang Peiguo; Wang Ping; Zhang Weiming

2008-01-01

Objective: To investigate the enhancement of radiosensitivity of recombinant Ad-p53 gene on human lung adenocarcinoma cell lines(A549 and GLC-82) with different p53 status in vitro. Methods: Two human lung adenocarcinoma cell lines of A549 and GLC-82 were examined on their difference in p53 status with immunohistochemistry stain and PCR-SSCP technique. Expand Ad-wtp53 was transfected into tumor cells. Clonogenic assays were performed to evaluate the inhibition effect on cell growth and the degree of sensitization to irradiation. Apoptosis and cell cycle changes were determined using the flow cytometry assay. Results: The A549 cell line presented positive P53 expression while GLC-82 negative. GLC-82 bore mutant p53 on the exon 7. The wtp53 gene could be efficiently expressed in the two cell lines and greatly inhibit the cell growth. Its efficiency didn't depend on the intrinsic p53 genetic status. After irradiation, its function of inducing G 1 arrest and apoptosis on GLC-82 cell line was much stronger than the A549 cell line. In both the A549 and GLC-82 cell lines, the combination of Ad-p53 plus radiation resulted in more apoptosis than the others. There was no significant difference between two groups. Conclusions: Ad-p53 can depress the tumor growth and enhance the radiosensitivity of human lung adenocarcinoma cells. And this effect is independent of endogenous p53 status. (authors)

The expanding universe of p53 targets.

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Menendez, Daniel; Inga, Alberto; Resnick, Michael A

2009-10-01

The p53 tumour suppressor is modified through mutation or changes in expression in most cancers, leading to the altered regulation of hundreds of genes that are directly influenced by this sequence-specific transcription factor. Central to the p53 master regulatory network are the target response element (RE) sequences. The extent of p53 transactivation and transcriptional repression is influenced by many factors, including p53 levels, cofactors and the specific RE sequences, all of which contribute to the role that p53 has in the aetiology of cancer. This Review describes the identification and functionality of REs and highlights the inclusion of non-canonical REs that expand the universe of genes and regulation mechanisms in the p53 tumour suppressor network.

p53-dependent and p53-independent anticancer activity of a new indole derivative in human osteosarcoma cells

Energy Technology Data Exchange (ETDEWEB)

Cappadone, C., E-mail: concettina.cappadone@unibo.it [Department of Pharmacy and Biotechnology, University of Bologna, Bologna (Italy); Stefanelli, C. [Department for Life Quality Studies, University of Bologna, Rimini Campus, Rimini (Italy); Malucelli, E. [Department of Pharmacy and Biotechnology, University of Bologna, Bologna (Italy); Zini, M. [Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna (Italy); Onofrillo, C. [Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna (Italy); Locatelli, A.; Rambaldi, M.; Sargenti, A. [Department of Pharmacy and Biotechnology, University of Bologna, Bologna (Italy); Merolle, L. [ELETTRA–Sincrotrone Trieste S.C.p.A., Trieste (Italy); Farruggia, G. [Department of Pharmacy and Biotechnology, University of Bologna, Bologna (Italy); National Institute of Biostructures and Biosystems, Roma (Italy); Graziadio, A. [Department of Pharmacy and Biotechnology, University of Bologna, Bologna (Italy); Montanaro, L. [Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna (Italy); Iotti, S. [Department of Pharmacy and Biotechnology, University of Bologna, Bologna (Italy); National Institute of Biostructures and Biosystems, Roma (Italy)

2015-11-13

Osteosarcoma (OS) is the most common primary malignant tumor of bone, occurring most frequently in children and adolescents. The mechanism of formation and development of OS have been studied for a long time. Tumor suppressor pathway governed by p53 gene are known to be involved in the pathogenesis of osteosarcoma. Moreover, loss of wild-type p53 activity is thought to be a major predictor of failure to respond to chemotherapy in various human cancers. In previous studies, we described the activity of a new indole derivative, NSC743420, belonging to the tubulin inhibitors family, capable to induce apoptosis and arrest of the cell cycle in the G2/M phase of various cancer cell lines. However, this molecule has never been tested on OS cell line. Here we address the activity of NSC743420 by examine whether differences in the p53 status could influence its effects on cell proliferation and death of OS cells. In particular, we compared the effect of the tested molecule on p53-wild type and p53-silenced U2OS cells, and on SaOS2 cell line, which is null for p53. Our results demonstrated that NSC743420 reduces OS cell proliferation by p53-dependent and p53-independent mechanisms. In particular, the molecule induces proliferative arrest that culminate to apoptosis in SaOS2 p53-null cells, while it brings a cytostatic and differentiating effect in U2OS cells, characterized by the cell cycle arrest in G0/G1 phase and increased alkaline phosphatase activity. - Highlights: • The indole derivative NSC743420 induces antitumor effects on osteosarcoma cells. • p53 status could drive the activity of antitumor agents on osteosarcoma cells. • NSC743420 induces cytostatic and differentiating effects on U2OS cells. • NSC743420 causes apoptosis on p53-null SaOS2 cells.

p53-dependent and p53-independent anticancer activity of a new indole derivative in human osteosarcoma cells

International Nuclear Information System (INIS)

Cappadone, C.; Stefanelli, C.; Malucelli, E.; Zini, M.; Onofrillo, C.; Locatelli, A.; Rambaldi, M.; Sargenti, A.; Merolle, L.; Farruggia, G.; Graziadio, A.; Montanaro, L.; Iotti, S.

2015-01-01

Osteosarcoma (OS) is the most common primary malignant tumor of bone, occurring most frequently in children and adolescents. The mechanism of formation and development of OS have been studied for a long time. Tumor suppressor pathway governed by p53 gene are known to be involved in the pathogenesis of osteosarcoma. Moreover, loss of wild-type p53 activity is thought to be a major predictor of failure to respond to chemotherapy in various human cancers. In previous studies, we described the activity of a new indole derivative, NSC743420, belonging to the tubulin inhibitors family, capable to induce apoptosis and arrest of the cell cycle in the G2/M phase of various cancer cell lines. However, this molecule has never been tested on OS cell line. Here we address the activity of NSC743420 by examine whether differences in the p53 status could influence its effects on cell proliferation and death of OS cells. In particular, we compared the effect of the tested molecule on p53-wild type and p53-silenced U2OS cells, and on SaOS2 cell line, which is null for p53. Our results demonstrated that NSC743420 reduces OS cell proliferation by p53-dependent and p53-independent mechanisms. In particular, the molecule induces proliferative arrest that culminate to apoptosis in SaOS2 p53-null cells, while it brings a cytostatic and differentiating effect in U2OS cells, characterized by the cell cycle arrest in G0/G1 phase and increased alkaline phosphatase activity. - Highlights: • The indole derivative NSC743420 induces antitumor effects on osteosarcoma cells. • p53 status could drive the activity of antitumor agents on osteosarcoma cells. • NSC743420 induces cytostatic and differentiating effects on U2OS cells. • NSC743420 causes apoptosis on p53-null SaOS2 cells.

Hipersonolência diurna e variáveis polissonográficas em doentes com síndroma de apneia do sono

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O. Mediano

2007-11-01

Full Text Available Resumo: A síndroma de apneia obstrutiva do sono (SAOS caracteriza-se por episódios repetidos de obstrução da via aérea superior, hipoxemia nocturna e fragmentação do sono. A hipersonolência diurna constitui um sintoma frequente nos doentes com esta síndroma, embora possa estar ausente. A sua presença representa uma limitação significativa da qualidade de vida do indivíduo, bem como um aumento da morbilidade e mortalidade da SAOS, visto ser um importante factor de risco para acidentes de viação e laborais, podendo originar alterações cognitivo-comportamentais relevantes.O mecanismo desencadeante de hipersonolência diurna não é claro. Alguns autores relacionaram esta com a arquitectura anormal do sono, o que, no entanto, não foi confirmado por outros investigadores. Alguns estudos salientaram a relação entre a hipersonolência diurna e os níveis de dessaturação nocturna da oxi-hemoglobina, mas este facto não foi comprovado cientificamente.O objectivo do presente trabalho foi analisar quais os mecanismos responsáveis pela sonolência diurna nos doentes com SAOS. Assim, numerosas variáveis registadas no estudo polissonográfico foram compara das em dois grupos de indivíduos com esta patologia, apresentando um deles hipersonolência diurna inequívoca e o outro a total ausência da mesma.Foram avaliados 65 indivíduos seguidos no Departamento Respiratório do Hospital Universitário do Son Dureta (Palma de Maiorca que possuíam no registo poligráfico nocturno um índice de apneia/hipopneia (IAH >20/h. A sonolência excessiva foi determinada utilizando a escala de sono de Epworth (ESE e o teste de latência múltipla. A sua presença foi considerada sempre que o score de ESE >10 e o score do teste de latência múltipla 10 min.Cerca de 25 indivíduos foram excluídos devido a discrepância entre os resultados das referidas determinações. Dos 40 doentes restantes, 23 apresentavam hipersonolência diurna e 17 n

Interplay between PTB and miR-1285 at the p53 3′UTR modulates the levels of p53 and its isoform Δ40p53α

Science.gov (United States)

Katoch, Aanchal; George, Biju; Iyyappan, Amrutha; Khan, Debjit

2017-01-01

Abstract p53 and its translational isoform Δ40p53 are involved in many important cellular functions like cell cycle, cell proliferation, differentiation and metabolism. Expression of both the isoforms can be regulated at different steps. In this study, we explored the role of 3′UTR in regulating the expression of these two translational isoforms. We report that the trans acting factor, Polypyrimidine Tract Binding protein (PTB), also interacts specifically with 3′UTR of p53 mRNA and positively regulates expression of p53 isoforms. Our results suggest that there is interplay between miRNAs and PTB at the 3′UTR under normal and stress conditions like DNA damage. Interestingly, PTB showed some overlapping binding regions in the p53 3′UTR with miR-1285. In fact, knockdown of miR-1285 as well as expression of p53 3′UTR with mutated miR-1285 binding sites resulted in enhanced association of PTB with the 3′UTR, which provides mechanistic insights of this interplay. Taken together, the results provide a plausible molecular basis of how the interplay between miRNAs and the PTB protein at the 3′UTR can play pivotal role in fine tuning the expression of the two p53 isoforms. PMID:28973454

Human neuroblastoma cells with acquired resistance to the p53 activator RITA retain functional p53 and sensitivity to other p53 activating agents

NARCIS (Netherlands)

Michaelis, M.; Rothweiler, F.; Agha, B.; Barth, S.; Voges, Y.; Loeschmann, N.; von Deimling, A.; Breitling, R.; Doerr, H. Wilhelm; Roedel, F.; Speidel, D.; Cinatl, J.; Cinatl Jr., J.; Stephanou, A.

Adaptation of wild-type p53 expressing UKF-NB-3 cancer cells to the murine double minute 2 inhibitor nutlin-3 causes de novo p53 mutations at high frequency (13/20) and multi-drug resistance. Here, we show that the same cells respond very differently when adapted to RITA, a drug that, like nutlin-3,

A importância do gene p53 na carcinogênese humana The importance of the p53 gene in human carcinogenesis

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Agnes C. Fett-Conte

2002-04-01

Full Text Available Existem várias razões que justificam o título de "guardião do genoma" do gene P53. Seu envolvimento, direto ou indireto, tem sido observado na etiopatogenia de praticamente todas as neoplasias humanas, incluindo as leucemias e linfomas. Conhecer seus mecanismos de ação é fundamental para compreender os aspectos moleculares da carcinogênese. O presente trabalho apresenta uma revisão sobre as características deste gene e sua importância no diagnóstico, prognóstico e terapêutica, o que faz dele um alvo em potencial das estratégias de terapia gênica.There are several reasons which justify the name of 'guardian of the genome' given to the P53 gene. Its involvement either directly or indirectly has been observed in the pathology of practically all human neoplasias, including leukemia and lymphomas. Knowledge of its mechanisms of action is fundamental to understand molecular aspects of carcinogenesis. This work presents a revision of the characteristics of this gene and its importance in the diagnosis, prognosis and treatment and why this makes it a potential target for gene therapy strategies.

Matérias estranhas em canela em pó e páprica em pó, comercializadas no estado de São Paulo

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CORREIA Marlene

2000-01-01

Full Text Available Com objetivos de padronizar metodologias para matérias estranhas em canela em pó e páprica em pó e de avaliar as condições higiênicas desses condimentos, foram adquiridas, no período de agosto a novembro de 1998, 78 amostras de canela em pó e 56 de páprica em pó, em estabelecimentos comerciais de seis cidades do Estado de São Paulo. Foram utilizados métodos da Association of Official Analytical Chemists International (AOAC - 1995, 16.14.12/968.38b para canela em pó e 16.14.22/977.25B para páprica em pó. Os métodos mostraram-se adequados, sem resíduos interferentes no papel de filtro que dificultasse o diagnóstico da análise e viáveis de serem utilizados nos laboratórios de Microscopia de Alimentos. Os resultados obtidos indicaram 100% das amostras contendo fragmentos de insetos; pêlos de roedor foram isolados em 73,1% de amostras de canela em pó e 34,0% de páprica em pó, enquanto ácaros mortos apareceram, respectivamente, em 37,2% e 12,5% de amostras. É necessário revisão da legislação de alimentos em vigor, com o estabelecimento de níveis de tolerância para fragmentos de insetos.

Expression of Egr1 and p53 in human carotid plaques and apoptosis induced by 7-oxysterol or p53.

Science.gov (United States)

Miah, Sayem; Zadeh, Shahram Nour Mohammad; Yuan, Xi-Ming; Li, Wei

2013-07-01

Egr-1 and p53 are involved in pathology of both atherosclerosis and cancer. However, it is unknown whether p53 and Egr1 are interactively involved in apoptosis in atherosclerosis. We found that in human carotid plaques, the expression of p53 was inversely correlated with Egr1. In U937 cells, 7β-hydroxycholesterol and 7-ketocholesterol induced production of reactive oxygen species (ROS), transient up-regulation of Egr1 followed by late induction of p53 and apoptosis. Cells with nuclear fragmentation induced by 7-oxysterol or p53 showed increased levels of p53, but decreased levels of Egr1. In conclusion, ROS induced by 7-oxysterols may function as an early initiator of Egr1 expression. The late induced p53 by 7-oxysterols contributes to apoptotic cell death and is linked to the reduction of Egr1 levels, which resembles the differential expression of p53 and Egr1 in human atheroma progression. Copyright © 2012 Elsevier GmbH. All rights reserved.

Estudo retrospectivo de um grupo de doentes submetidos a cirurgia bariátrica

OpenAIRE

Santos, Mariline

2012-01-01

Trabalho final do 6º ano médico (Medicina interna - Nutrição clínica), com vista à atribuição do Grau de Mestre no âmbito do ciclo de estudos de mestrado integrado em Medicina da Universidade de Coimbra Objectivo: Estudar retrospectivamente uma população de doentes obesos submetidos a cirurgia bariátrica. Avaliar as técnicas cirúrgicas usadas e respectivas complicações assim como avaliar a eficácia da cirurgia bariátrica a longo prazo não só como terapêutica de obesidade como também das co...

Disruption of focal adhesion kinase and p53 interaction with small molecule compound R2 reactivated p53 and blocked tumor growth

International Nuclear Information System (INIS)

Golubovskaya, Vita M; Ho, Baotran; Zheng, Min; Magis, Andrew; Ostrov, David; Morrison, Carl; Cance, William G

2013-01-01

Focal Adhesion Kinase (FAK) is a 125 kDa non-receptor kinase that plays a major role in cancer cell survival and metastasis. We performed computer modeling of the p53 peptide containing the site of interaction with FAK, predicted the peptide structure and docked it into the three-dimensional structure of the N-terminal domain of FAK involved in the complex with p53. We screened small molecule compounds that targeted the site of the FAK-p53 interaction and identified compounds (called Roslins, or R compounds) docked in silico to this site. By different assays in isogenic HCT116p53 + / + and HCT116 p53 - / - cells we identified a small molecule compound called Roslin 2 (R2) that bound FAK, disrupted the binding of FAK and p53 and decreased cancer cell viability and clonogenicity in a p53-dependent manner. In addition, dual-luciferase assays demonstrated that the R2 compound increased p53 transcriptional activity that was inhibited by FAK using p21, Mdm-2, and Bax-promoter targets. R2 also caused increased expression of p53 targets: p21, Mdm-2 and Bax proteins. Furthermore, R2 significantly decreased tumor growth, disrupted the complex of FAK and p53, and up-regulated p21 in HCT116 p53 + / + but not in HCT116 p53 - / - xenografts in vivo. In addition, R2 sensitized HCT116p53 + / + cells to doxorubicin and 5-fluorouracil. Thus, disruption of the FAK and p53 interaction with a novel small molecule reactivated p53 in cancer cells in vitro and in vivo and can be effectively used for development of FAK-p53 targeted cancer therapy approaches

TRIM65 negatively regulates p53 through ubiquitination

Energy Technology Data Exchange (ETDEWEB)

Li, Yang [Department of Respiration, The First Hospital of Jilin University, Changchun 130021 (China); Ma, Chengyuan [Department of Neurosurgery, The First Hospital of Jilin University, Changchun 130021 (China); Zhou, Tong [Department of Endocrinology, The First Hospital of Jilin University, Changchun 130021 (China); Liu, Ying [Department of Respiration, The First Hospital of Jilin University, Changchun 130021 (China); Sun, Luyao [Department of Infectious Diseases, The First Hospital of Jilin University, Changchun 130021 (China); Yu, Zhenxiang, E-mail: zhenxiangyu2015@gmail.com [Department of Respiration, The First Hospital of Jilin University, Changchun 130021 (China)

2016-04-22

Tripartite-motif protein family member 65 (TRIM65) is an important protein involved in white matter lesion. However, the role of TRIM65 in human cancer remains less understood. Through the Cancer Genome Atlas (TCGA) gene alteration database, we found that TRIM65 is upregulated in a significant portion of non-small cell lung carcinoma (NSCLC) patients. Our cell growth assay revealed that TRIM65 overexpression promotes cell proliferation, while knockdown of TRIM65 displays opposite effect. Mechanistically, TRIM65 binds to p53, one of the most critical tumor suppressors, and serves as an E3 ligase toward p53. Consequently, TRIM65 inactivates p53 through facilitating p53 poly-ubiquitination and proteasome-mediated degradation. Notably, chemotherapeutic reagent cisplatin induction of p53 is markedly attenuated in response to ectopic expression of TRIM65. Cell growth inhibition by TRIM65 knockdown is more significant in p53 positive H460 than p53 negative H1299 cells, and knockdown of p53 in H460 cells also shows compromised cell growth inhibition by TRIM65 knockdown, indicating that p53 is required, at least in part, for TRIM65 function. Our findings demonstrate TRIM65 as a potential oncogenic protein, highly likely through p53 inactivation, and provide insight into development of novel approaches targeting TRIM65 for NSCLC treatment, and also overcoming chemotherapy resistance. - Highlights: • TRIM65 expression is elevated in NSCLC. • TRIM65 inactivates p53 through mediating p53 ubiquitination and degradation. • TRIM65 attenuates the response of NSCLC cells to cisplatin.

Melhoria da capacidade inspiratória em repouso e da hiperinsuflação com o tiotrópio em doentes com DPOC e com aumento dos volumes estáticos pulmonares

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B. Celli

2003-11-01

Full Text Available RESUMO: O reconhecimento da eficácia de um broncodilatador na DPOC deve incluir o registo dos volumes pulmonares, que fornecem informação acerca da hiperinsuflação e, consequentemente, da dispneia. É reconhecido que após a administração de um broncodilatador as alterações do VEMS não reflectem necessariamente alterações do grau de dispneia, podendo este parâmetro funcional não demonstrar o potencial benéfico de um fármaco na DPOC.As modificações da Capacidade Inspiratória (CI demonstraram já uma melhor correlação com a dispneia e intolerância ao esforço, em relação a outros parâmetros espirométricos, pois reflectem modificações da hiperinsuflação.O tiotrópio é um anticolinérgico que antagoniza de forma prolongada o receptor muscarínico M3, proporcionando uma melhoria clínica e funcional em doentes com DPOC. Este estudo randomizado, duplamente cego, com controlo de placebo, pretendeu avaliar as alterações da CI em repouso e dos volumes pulmonares após administração a longo prazo do tiotrópio.A população estudada de 81 doentes com DPOC (62% do sexo masculino; 72% ex-fumadores, com idade superior a 40 anos (idade média de 64 anos, apresentava um valor basal médio de VEMS de 1,12 l (43% do previsto. Nas 3 visitas efectuadas (0, 2 e 4 semanas, o VEMS, a capacidade vital forçada e lenta, a CI e o volume de gás intratorácico foram determinados antes da administração do tiotrópio (–60 e –15 minutos e após a toma da droga (30, 60, 120 e 180 minutos. Verificaram-se diferenças estatisticamente significativas nos grupos tiotrópio/placebo em relação ao VEMS, capacidades vitais, CI e volume de gás intratorácico. Neste estudo, a redução do volume de gás intratorácico foi similar ao obtido aos 3 e 6 meses após cirurgia de redução de volume

Immunohistochemical expression of p53, BCL-2, BAX and VEGFR1 proteins in nephroblastomas A expressão imuno-histoquímica das proteínas p53, BCL-2, BAX e VEGFR1 em nefroblastomas

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Ana Paula Percicote

2013-02-01

marcadores imuno-histoquímicos tem por objetivo adequar o tratamento ao grupo de risco e reduzir recidivas e óbitos. Entre os marcadores mais estudados estão p53, B-cell lymphoma 2 (BCL-2, BCL-2 associated protein X (BAX e fator de crescimento vascular endotelial e seu receptor 1 (VEGFR1, relacionados com a via apoptótica, o reparo do ácido desoxirribonucleico (DNA e a neovascularização. OBJETIVO: O objetivo deste estudo é avaliar a expressão imuno-histoquímica de p53, BCL-2, BAX e VEGFR1 em amostras de nefroblastoma humano e correlacioná-las com fatores prognósticos clínico-patológicos. MATERIAL E MÉTODO: Foram utilizadas 29 amostras de nefroblastomas retiradas dos Serviços de Anatomia Patológica de dois hospitais de Curitiba, com diagnósticos entre 1994 e 2007. Por meio da técnica de imunoperoxidase, com as amostras em arranjo tecidual em matriz, realizou-se análise da imuno-histoquímica desses marcadores e sua comparação com fatores prognósticos clínico-patológicos. RESULTADOS: A maior imunoexpressão de VEGFR1 nos componentes blastematoso e epitelial mostrou associação positiva ao grupo de risco, sendo que isso poderia estar relacionado com a maior capacidade de invasão vascular neoplásica que pode ser conferida por esse fator de crescimento endotelial, aumentando, assim, as chances de metástases e alterando o estadimento, o grupo de risco e a evolução clínica. CONCLUSÃO: A expressão imuno-histoquímica aumentada de VEGFR1 mostrou associação diretamente proporcional ao grupo de risco dos pacientes com nefroblastoma.

Validação da versão em português da escala London Chest Activity of Daily Living (LCADL em doentes com doença pulmonar obstrutiva crónica

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Fábio Pitta

2008-01-01

Full Text Available Resumo: Introdução: Diversos questionários desenvolvidos em língua inglesa visam avaliar especificamente a limitação pela dispnéia durante actividades da vida diária (AVD em doentes com doença pulmonar obstrutiva crónica (DPOC, como a escala London Chest Activity of Daily Living (LCADL. No entanto, nenhum destes questionários foi ainda traduzido para a língua portuguesa. O objectivo desse estudo foi verificar a validade e a reprodutibilidade da versão em português da LCADL em pacientes com DPOC. Métodos: Trinta e um doentes com DPOC (17 homens; 69±7 anos; FEV1 44±15% predito responderam por duas vezes à versão em português da LCADL com intervalo de uma semana. O tradicional questionário Saint George na doença respiratória (SGRQ, já validado em português, foi utilizado como critério de validação. Resultados: Não foram observadas diferenças significativas entre a aplicação e a reaplicação da LCADL. O coeficiente de correlação intraclasse dos domínios da escala entre o dia 1 e dia 2 foi de: Cuidado pessoal r=0,96; doméstico r=0,99; actividade física r=0,92; lazer r=0,95; escore total r=0,98. Foram observadas correlações significativas do escore total da LCADL com os domínios e o escore total do SGRQ (0,36p<0,05 para todos. O escore total da LCADL correlacionou-se também significativamente com a distância percorrida no teste da caminhada de 6 minutos (r=-0,48; p=0,006. Conclusões: A versão em língua portuguesa da LCADL demonstrou ser reprodutível e válida em pacientes com DPOC. Portanto, o presente estudo fornece uma nova e importante ferramenta para avaliar a limitação na capacidade de realizar AVD nessa população.Rev Port Pneumol 2008; XIV (1: 27-47 Abstract: Introduction: While there are several subjective English tools, such as the London Chest Activity of Daily Living scale

Chemical Variations on the p53 Reactivation Theme

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Carlos J. A. Ribeiro

2016-05-01

Full Text Available Among the tumor suppressor genes, p53 is one of the most studied. It is widely regarded as the “guardian of the genome”, playing a major role in carcinogenesis. In fact, direct inactivation of the TP53 gene occurs in more than 50% of malignancies, and in tumors that retain wild-type p53 status, its function is usually inactivated by overexpression of negative regulators (e.g., MDM2 and MDMX. Hence, restoring p53 function in cancer cells represents a valuable anticancer approach. In this review, we will present an updated overview of the most relevant small molecules developed to restore p53 function in cancer cells through inhibition of the p53-MDMs interaction, or direct targeting of wild-type p53 or mutated p53. In addition, optimization approaches used for the development of small molecules that have entered clinical trials will be presented.

A surrogate p53 reporter in Drosophila reveals the interaction of eIF4E and p53

International Nuclear Information System (INIS)

Corujo, G.; Campagno, R.; Rivera Pomar, R.; Ferrero, P.; Lu, W.J.

2011-01-01

eIF4E promotes translation upon binding the mRNA 5'cap and it is required for cell proliferation. p53 is a proapoptotic protein which is activated in response to DNA damage. There is evidence that suggests that eIF4E and p53 are connected in a mechanism that regulates their function. We propose a model for that such a mechanism to explain the equilibrium between apoptosis and cell proliferation. Our data shows a correlation between the overexpression of eIF4E and the suppression of apoptosis triggered by the overexpression of p53 in Drosophila imaginal discs. We also studied a reporter transgene which expresses GFP in response to p53 activation by gamma radiation. We could confirm that this p53 surrogate works in imaginal discs as well as in embryos. This provided us a tool to quantify the effect on the GFP signal by overexpression of eIF4E to confirm how these two proteins could interact in vivo. Our results suggest that p53 and eIF4E are indeed in an equilibrium that decides if a cell shall proliferate or die. (authors)

Both p53-PUMA/NOXA-Bax-mitochondrion and p53-p21cip1 pathways are involved in the CDglyTK-mediated tumor cell suppression

International Nuclear Information System (INIS)

Yu, Zhendong; Wang, Hao; Zhang, Libin; Tang, Aifa; Zhai, Qinna; Wen, Jianxiang; Yao, Li; Li, Pengfei

2009-01-01

CDglyTK fusion suicide gene has been well characterized to effectively kill tumor cells. However, the exact mechanism and downstream target genes are not fully understood. In our study, we found that CDglyTK/prodrug treatment works more efficiently in p53 wild-type (HONE1) cells than in p53 mutant (CNE1) cells. We then used adenovirus-mediated gene delivery system to either knockdown or overexpress p53 and its target genes in these cells. Consistent results showed that both p53-PUMA/NOXA/Bcl2-Bax and p53-p21 pathways contribute to the CDglyTK induced tumor cell suppression. Our work for the first time addressed the role of p53 related genes in the CDglyTK/prodrug system.

Both p53-PUMA/NOXA-Bax-mitochondrion and p53-p21cip1 pathways are involved in the CDglyTK-mediated tumor cell suppression

Energy Technology Data Exchange (ETDEWEB)

Yu, Zhendong, E-mail: zdyu@hotmail.com [Department of Clinical laboratory, Peking University Shenzhen Hospital, Guangdong (China); Wang, Hao [Department of pathology, The Chinese University of Hong Kong, Hong Kong (China); Zhang, Libin; Tang, Aifa; Zhai, Qinna; Wen, Jianxiang; Yao, Li [Department of Clinical laboratory, Peking University Shenzhen Hospital, Guangdong (China); Li, Pengfei, E-mail: lipengfei@cuhk.edu.hk [Department of pathology, The Chinese University of Hong Kong, Hong Kong (China)

2009-09-04

CDglyTK fusion suicide gene has been well characterized to effectively kill tumor cells. However, the exact mechanism and downstream target genes are not fully understood. In our study, we found that CDglyTK/prodrug treatment works more efficiently in p53 wild-type (HONE1) cells than in p53 mutant (CNE1) cells. We then used adenovirus-mediated gene delivery system to either knockdown or overexpress p53 and its target genes in these cells. Consistent results showed that both p53-PUMA/NOXA/Bcl2-Bax and p53-p21 pathways contribute to the CDglyTK induced tumor cell suppression. Our work for the first time addressed the role of p53 related genes in the CDglyTK/prodrug system.

p53 specific (auto)immunity in mice

NARCIS (Netherlands)

Lauwen, Marjolein Monique

2008-01-01

Self-tolerance to p53 is a major potential limitation for the activation of the endogenous T-cell repertoire. So far, p53 specific CD8+ and CD4+ T-cell immunity has been described in cancer patients and healthy individuals. However, the restrictions of tolerance on the recruitment of p53 specific T

Exploring a minimal two-component p53 model

International Nuclear Information System (INIS)

Sun, Tingzhe; Zhu, Feng; Shen, Pingping; Yuan, Ruoshi; Xu, Wei

2010-01-01

The tumor suppressor p53 coordinates many attributes of cellular processes via interlocked feedback loops. To understand the biological implications of feedback loops in a p53 system, a two-component model which encompasses essential feedback loops was constructed and further explored. Diverse bifurcation properties, such as bistability and oscillation, emerge by manipulating the feedback strength. The p53-mediated MDM2 induction dictates the bifurcation patterns. We first identified irradiation dichotomy in p53 models and further proposed that bistability and oscillation can behave in a coordinated manner. Further sensitivity analysis revealed that p53 basal production and MDM2-mediated p53 degradation, which are central to cellular control, are most sensitive processes. Also, we identified that the much more significant variations in amplitude of p53 pulses observed in experiments can be derived from overall amplitude parameter sensitivity. The combined approach with bifurcation analysis, stochastic simulation and sampling-based sensitivity analysis not only gives crucial insights into the dynamics of the p53 system, but also creates a fertile ground for understanding the regulatory patterns of other biological networks

Hipersonolência diurna e variáveis polissonográficas em doentes com síndroma de apneia do sono

Directory of Open Access Journals (Sweden)

O. Mediano

2007-11-01

Full Text Available Resumo: A síndroma de apneia obstrutiva do sono (SAOS caracteriza-se por episódios repetidos de obstrução da via aérea superior, hipoxemia nocturna e fragmentação do sono. A hipersonolência diurna constitui um sintoma frequente nos doentes com esta síndroma, embora possa estar ausente. A sua presença representa uma limitação significativa da qualidade de vida do indivíduo, bem como um aumento da morbilidade e mortalidade da SAOS, visto ser um importante factor de risco para acidentes de viação e laborais, podendo originar alterações cognitivo-comportamentais relevantes.O mecanismo desencadeante de hipersonolência diurna não é claro. Alguns autores relacionaram esta com a arquitectura anormal do sono, o que, no entanto, não foi confirmado por outros investigadores. Alguns estudos salientaram a relação entre a hipersonolência diurna e os níveis de dessaturação nocturna da oxi-hemoglobina, mas este facto não foi comprovado cientificamente.O objectivo do presente trabalho foi analisar quais os mecanismos responsáveis pela sonolência diurna nos doentes com SAOS. Assim, numerosas variáveis registadas no estudo polissonográfico foram comparadas em dois grupos de indivíduos com esta patologia, apresentando um deles hipersonolência diurna inequívoca e o outro a total ausência da mesma.Foram avaliados 65 indivíduos seguidos no Departamento Respiratório do Hospital Universitário do Son Dureta (Palma de Maiorca que possuíam no registo poligráfico nocturno um índice de apneia/hipopneia (IAH >20/h. A sonolência excessiva foi determinada utilizando a escala de sono de Epworth (ESE e o teste de latência múltipla. A sua presença foi considerada sempre que o score de ESE >10 e o score do teste de latência múltipla 10 min.Cerca de 25 indivíduos foram excluídos devido a discrepância entre os resultados das referidas determinações. Dos 40 doentes restantes, 23 apresentavam hipersonolência diurna e 17 n

The Transcriptional Landscape of p53 Signalling Pathway

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Chizu Tanikawa

2017-06-01

Full Text Available Although recent cancer genomics studies have identified a large number of genes that were mutated in human cancers, p53 remains as the most frequently mutated gene. To further elucidate the p53-signalling network, we performed transcriptome analysis on 24 tissues in p53+/+ or p53−/− mice after whole-body X-ray irradiation. Here we found transactivation of a total of 3551 genes in one or more of the 24 tissues only in p53+/+ mice, while 2576 genes were downregulated. p53 mRNA expression level in each tissue was significantly associated with the number of genes upregulated by irradiation. Annotation using TCGA (The Cancer Genome Atlas database revealed that p53 negatively regulated mRNA expression of several cancer therapeutic targets or pathways such as BTK, SYK, and CTLA4 in breast cancer tissues. In addition, stomach exhibited the induction of Krt6, Krt16, and Krt17 as well as loricrin, an epidermal differentiation marker, after the X-ray irradiation only in p53+/+ mice, implying a mechanism to protect damaged tissues by rapid induction of differentiation. Our comprehensive transcriptome analysis elucidated tissue specific roles of p53 and its signalling networks in DNA-damage response that will enhance our understanding of cancer biology.

Adenocarcinoma of the esophagogastric junction: relationship between clinicopathological data and p53, cyclin D1 and Bcl-2 immunoexpressions Adenocarcinoma da junção esôfago-gástrica: relação entre os dados cllnipatológicos e a imunoexpressão de p53, ciclina D1 e Bcl-2

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Dárcio Matenhauer Lehrbach

2009-12-01

Full Text Available CONTEXT: Esophagogastric junction adenocarcinoma has an aggressive behavior, and TNM (UICC staging is not always accurate enough to categorize patient's outcome. OBJECTIVES: To evaluated p53, cyclin D1 and Bcl-2 immunoexpressions in esophagogastric junction adenocarcinoma patients, without Barrett's esophagus, and to compared to clinicopathological characteristics and survival rate. METHODS: Tissue sections from 75 esophagogastric junction adenocarcinomas resected from 1991 to 2003 were analyzed by immunohistochemistry for p53, cyclin D1 and Bcl-2 using streptavidin-biotin-peroxidase method. The mean follow-up time was 60 months SD = 61.5 (varying from 4 to 273 months. RESULTS: Fifty (66.7% of the tumors were intestinal type and 25 (33.3% were diffuse. Vascular, lymph node and perineural infiltration were verified in 16%, 80% and 68% of the patients, respectively. The patients were distributed according to the TNM staging in IA in 4 (5.3%, IB in 10 (13.3%, II in 15 (20%, IIA in 15 (20%, IIIB in 15 (20% and IV in 16 (21.3%. Immunohistochemical analysis was positive for p53, cyclin D1 and bcl-2 in 68%, 18.7% and 100%, respectively. There was no association between immunoexpression and vascular and/or perineural invasions, clinicopathological characteristics and patients' survival rate. CONCLUSION: In this selected population, there was no association between the immunomarkers, p53, cyclin D1 and bcl-2 and clinicopathological data and/or overall survival.CONTEXTO: O adenocarcinoma da junção esôfago-gástrica tem um comportamento agressivo e o estádio TNM não é sempre suficiente para categorizar o paciente de acordo com a evolução do mesmo. OBJETIVO: Avaliar a imunoexpressão do p53, ciclina D1 e Bcl-2 em pacientes com adenocarcinoma da junção esôfago-gástrica sem esôfago de Barrett e comparar com as características clínicas e sobrevida. MÉTODOS: Cortes histológicos de 75 adenocarcinomas da esôfago-gástrica ressecados de 1991 a

Expression of p53 in oligodendrogliomas

NARCIS (Netherlands)

J.M. Kros (Johan); J.J.C.J. Godschalk (J. J C J); K.K. Krishnadath (Kausilia); C.G. van Eden (C.)

1993-01-01

textabstractThe expression of the nuclear protein p53 in oligodendrogliomas was investigated by immunohistochemistry, using a monoclonal anti-p53 antibody (DO-7) on formalin-fixed, paraffin-embedded material in 84 histologically verified cases, and compared with the histopathological grade and

Expression of p53 in oligodendrogliomas

NARCIS (Netherlands)

Kros, J. M.; Godschalk, J. J.; Krishnadath, K. K.; van Eden, C. G.

1993-01-01

The expression of the nuclear protein p53 in oligodendrogliomas was investigated by immunohistochemistry, using a monoclonal anti-p53 antibody (DO-7) on formalin-fixed, paraffin-embedded material in 84 histologically verified cases, and compared with the histopathological grade and survival.

Indicadores de Prognóstico em Câncer de Mama com Axila Negativa: Receptor de Estrógeno e Expressão de P53 e de c-erbB-2 Prognostic Indicators In Lymph Node-Negative Breast Cancer: Estrogen Receptor and P53 and c-erbB-2 Protein Expression

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Adriana Harter Teixeira Bolaséll

2000-08-01

Full Text Available Objetivo: avaliar o valor prognóstico do receptor de estrógeno e da expressão das proteínas p53 e c-erbB-2 no câncer de mama com axila negativa. Métodos: foi realizado estudo imuno-histoquímico em material incluido em parafina, do arquivo do Instituto de Pesquisas Cito-Oncológicas (IPCO da Fundação Faculdade Federal de Ciências Médicas de Porto Alegre (FFFCMPA, de 50 casos de câncer de mama sem comprometimento dos linfonodos axilares, em mulheres menopausadas, tratadas na Irmandade da Santa Casa de Porto Alegre (ISCMPA e no Hospital Santa Rita de Porto Alegre (HSR de janeiro 1990 a dezembro de 1994. Para análise estatística foram utilizados os testes de c² com correção de Yates, teste exato de Fisher e curvas de sobrevida pelo método de Kaplan-Meier comparados pelo teste log rank. O seguimento médio das pacientes foi de 3,6 anos (3,1-4,5. Dos 50 casos, 14 apresentaram recidiva no período observado. Resultados: a média de idade foi 61 anos (variação de 46 a 78 anos. A mastectomia radical modificada (MRM foi realizada em 35 pacientes (70% e 15 (30% foram submetidas a setorectomia com esvaziamento axilar e posterior radioterapia. Metade das pacientes que apresentaram recidiva apresentaram-na nos três primeiros anos após o diagnóstico. O tamanho médio do tumor foi 2,8 cm (1,98-3,13 e o tipo histológico mais freqüente foi o carcinoma ductal infiltrante de tipo histológico não-especial (92%, conforme a graduação histológica de Bloom e Richardson, sendo 3 grau I (6,6%, 35 grau II (76% e 8 grau III (17,4%; nos tumores que recidivaram não houve nenhum grau I, 9 (25,7% eram grau II e 3 (37,5% eram grau III. Em relação ao prognóstico, a taxa de intervalo livre de doença foi menor quando da associação de tumor pouco diferenciado (grau III com receptor de estrógeno negativo (p = 0,006, p53 positivo (p = 0,006 e c-erbB-2 positivo (p = 0,001. Conclusão: mulheres menopausadas com câncer de mama sem comprometimento

The maternal genes Ci-p53/p73-a and Ci-p53/p73-b regulate zygotic ZicL expression and notochord differentiation in Ciona intestinalis embryos.

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Noda, Takeshi

2011-12-01

I isolated a Ciona intestinalis homolog of p53, Ci-p53/p73-a, in a microarray screen of rapidly degraded maternal mRNA by comparing the transcriptomes of unfertilized eggs and 32-cell stage embryos. Higher expression of the gene in eggs and lower expression in later embryonic stages were confirmed by whole-mount in situ hybridization (WISH) and quantitative reverse transcription-PCR (qRT-PCR); expression was ubiquitous in eggs and early embryos. Knockdown of Ci-p53/p73-a by injection of antisense morpholino oligonucleotides (MOs) severely perturbed gastrulation cell movements and expression of notochord marker genes. A key regulator of notochord differentiation in Ciona embryos is Brachyury (Ci-Bra), which is directly activated by a zic-like gene (Ci-ZicL). The expression of Ci-ZicL and Ci-Bra in A-line notochord precursors was downregulated in Ci-p53/p73-a knockdown embryos. Maternal expression of Ci-p53/p73-b, a homolog of Ci-p53/p73-a, was also detected. In Ci-p53/p73-b knockdown embryos, gastrulation cell movements, expression of Ci-ZicL and Ci-Bra in A-line notochord precursors, and expression of notochord marker gene at later stages were perturbed. The upstream region of Ci-ZicL contains putative p53-binding sites. Cis-regulatory analysis of Ci-ZicL showed that these sites are involved in expression of Ci-ZicL in A-line notochord precursors at the 32-cell and early gastrula stages. These results suggest that p53 genes are maternal factors that play a crucial role in A-line notochord differentiation in C. intestinalis embryos by regulating Ci-ZicL expression. Copyright © 2011 Elsevier Inc. All rights reserved.

p53 in differentiation of thyroid cancer

International Nuclear Information System (INIS)

Seyama, Toshio; Ito, Takashi; Akiyama, Mitoshi; Hayashi, Yuzo; Dohi, Kiyohiko.

1993-01-01

P53 is a tumor suppressor gene with such a recessive nature and is inactivated in many carcinomas. DNA was extracted from 10 primary papillary adenocarcinomas and eight undifferentiated carcinomas of the thyroid, using three 5 μm sliced paraffin segments, and then amplified by PCR. The products were analyzed for mutations in the p53 gene exons 5 to 8 by the direct sequencing method and for allelic deletion by the RFLP method. In five human thyroid carcinomas, DNA was extracted from each tissue and analyzed. Mutations in the p53 gene exons 5 to 8 and p53 gene deletions were not detected in the 10 papillary adenocarcinomas, mutations were detected in seven of eight cases and allelic deletions was detected in three of the five cases examined. In each of the five cases which had both differentiated and undifferentiated tissues in the same tumor, p53 gene mutations were not detected in the differentiated tissues while mutations and gene deletions were detected in the undifferentiated sections. The p53 gene was analyzed using paraffin-embedded tissues by the combined use of the direct sequencing and PCR methods and by the RFLP method. It was found that the progression of human thyroid carcinoma is closely related to the p53 genetic changes. Furthermore, the analysis of differentiated and undifferentiated tissues in the same tumor showed that human undifferentiated thyroid carcinomas develop from differentiated carcinomas. (J.P.N.)

Biologic effect of exogenous wild p53 combined with irradiation on human melanoma cell lines with different p53 status

International Nuclear Information System (INIS)

Min Fengling; Zhang Hong; Li Wenjian; Liu Bing; Zhou Qingming; Duan Xin; Gao Qingxiang

2007-01-01

Objective: To investigate the effect of low dose irradiation on gene transfer efficiency and the effect of adenoviral-mediated exogenous P53 overexpression on apoptosis and radiosensitivity of radioresistant human melanoma cell lines A375(wild type p53)and WM983a(mutant type p53). Methods: Control vector, a replication deficient recombinant adenoviral vector containing a CMV promoter and green fluorescent protein (AdCMV-GFP), was used to transfect A375 cells and WM983a cells preirradiated with or without 1 Gy X-ray. The transduction efficiency of GFP gene was determined with fluorescence microscope directly. These two types of cells irradiated by 1 Gy X-ray were transfected with a replication deficient recombinant adenoviral vector carrying human wild p53 (AdCMV-p53), and mRNA level was detected by RT-PCR. The cell cycle delay and the expression of exogenous P53 were detected using flow cytometry (FCM) at different times after transfection. Tunel technique was used to detect cell apoptosis. The radiosensivity of A375 and WM983a cells after p53 transduction was analyzed by colony formation. Results: It is found that 1 Gy irradiation increased the gene transfection efficiency of A375 and WM983a cells. The expression of exogenous P53 was found to range from 60% to 80% among transfected cells during the first three days after transduction and then declined continuously down to the control level on day 10. G 1 cell cycle arrest was also observed after p53 gene transduction. WM983a cells transfected with p53 showed higher sensitivity to X-ray-induced cell killing than A375 cells. Conclusions: It is indicated that low dose of ionizing radiation can improve gene transfection efficiency of A375 and WM983a cells mediated by adenovirus vector. Althrough the overexpresion of exogenous p53 may not inhibit cell growth and induce apoptosis of melanoma cell line A375 and WM983a irt vitro, the two cell lines are much more sensitive to cell death induced by irradiation. It is

p53 and the pathogenesis of skin cancer

International Nuclear Information System (INIS)

Benjamin, Cara L.; Ananthaswamy, Honnavara N.

2007-01-01

The p53 tumor suppressor gene and gene product are among the most diverse and complex molecules involved in cellular functions. Genetic alterations within the p53 gene have been shown to have a direct correlation with cancer development and have been shown to occur in nearly 50% of all cancers. p53 mutations are particularly common in skin cancers and UV irradiation has been shown to be a primary cause of specific 'signature' mutations that can result in oncogenic transformation. There are certain 'hot-spots' in the p53 gene where mutations are commonly found that result in a mutated dipyrimidine site. This review discusses the role of p53 from normal function and its dysfunction in pre-cancerous lesions and non-melanoma skin cancers. Additionally, special situations are explored, such as Li-Fraumeni syndrome in which there is an inherited p53 mutation, and the consequences of immune suppression on p53 mutations and the resulting increase in non-melanoma skin cancer in these patients

Análise de um acidente por contaminação fúngica em uma biblioteca pública no município do Rio de Janeiro

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Maria Cristina Strausz

Full Text Available Partindo de um acidente de contaminação por fungos ocorrido em dezembro de 1997 em uma biblioteca pública no município do Rio de Janeiro, foi testada a aplicabilidade de uma proposta metodológica de análise sociotécnica de acidentes, que foi desenvolvida pelo Centro de Estudo de Saúde do Trabalhador e Ecologia Humana (CESTEH/Fiocruz, para análise de acidentes industriais ampliados. O acidente foi conseqüência de um fato anunciado meses antes, quando os trabalhadores da biblioteca denunciaram, através de um abaixo-assinado, os problemas de descontrole da temperatura ambiente, que se traduzia em desconforto, sintomas respiratórios e afastamento do trabalho, decorrentes daquelas condições. O evento foi caracterizado como um caso de Síndrome do Edifício Doente, que é um problema decorrente da má qualidade do ar de interiores, especialmente em ambientes climatizados artificialmente. Nesse sentido, despertou a atenção dos profissionais de bibliotecas do Brasil para um problema bastante comum, embora pouco estudado, especialmente no campo da saúde pública e, dentro dela, o campo da saúde do trabalhador.

System-based strategies for p53 recovery.

Science.gov (United States)

Azam, Muhammad Rizwan; Fazal, Sahar; Ullah, Mukhtar; Bhatti, Aamer I

2018-06-01

The authors have proposed a systems theory-based novel drug design approach for the p53 pathway. The pathway is taken as a dynamic system represented by ordinary differential equations-based mathematical model. Using control engineering practices, the system analysis and subsequent controller design is performed for the re-activation of wild-type p53. p53 revival is discussed for both modes of operation, i.e. the sustained and oscillatory. To define the problem in control system paradigm, modification in the existing mathematical model is performed to incorporate the effect of Nutlin. Attractor point analysis is carried out to select the suitable domain of attraction. A two-loop negative feedback control strategy is devised to drag the system trajectories to the attractor point and to regulate cellular concentration of Nutlin, respectively. An integrated framework is constituted to incorporate the pharmacokinetic effects of Nutlin in the cancerous cells. Bifurcation analysis is also performed on the p53 model to see the conditions for p53 oscillation.

Microbial Regulation of p53 Tumor Suppressor.

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Alexander I Zaika

2015-09-01

Full Text Available p53 tumor suppressor has been identified as a protein interacting with the large T antigen produced by simian vacuolating virus 40 (SV40. Subsequent research on p53 inhibition by SV40 and other tumor viruses has not only helped to gain a better understanding of viral biology, but also shaped our knowledge of human tumorigenesis. Recent studies have found, however, that inhibition of p53 is not strictly in the realm of viruses. Some bacterial pathogens also actively inhibit p53 protein and induce its degradation, resulting in alteration of cellular stress responses. This phenomenon was initially characterized in gastric epithelial cells infected with Helicobacter pylori, a bacterial pathogen that commonly infects the human stomach and is strongly linked to gastric cancer. Besides H. pylori, a number of other bacterial species were recently discovered to inhibit p53. These findings provide novel insights into host-bacteria interactions and tumorigenesis associated with bacterial infections.

Battle Against Cancer: An Everlasting Saga of p53

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Qian Hao

2014-12-01

Full Text Available Cancer is one of the most life-threatening diseases characterized by uncontrolled growth and spread of malignant cells. The tumor suppressor p53 is the master regulator of tumor cell growth and proliferation. In response to various stress signals, p53 can be activated and transcriptionally induces a myriad of target genes, including both protein-encoding and non-coding genes, controlling cell cycle progression, DNA repair, senescence, apoptosis, autophagy and metabolism of tumor cells. However, around 50% of human cancers harbor mutant p53 and, in the majority of the remaining cancers, p53 is inactivated through multiple mechanisms. Herein, we review the recent progress in understanding the molecular basis of p53 signaling, particularly the newly identified ribosomal stress—p53 pathway, and the development of chemotherapeutics via activating wild-type p53 or restoring mutant p53 functions in cancer. A full understanding of p53 regulation will aid the development of effective cancer treatments.

Gain-of-function mutant p53 but not p53 deletion promotes head and neck cancer progression in response to oncogenic K-ras

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Acin, Sergio; Li, Zhongyou; Mejia, Olga; Roop, Dennis R; El-Naggar, Adel K; Caulin, Carlos

2015-01-01

Mutations in p53 occur in over 50% of the human head and neck squamous cell carcinomas (SCCHN). The majority of these mutations result in the expression of mutant forms of p53, rather than deletions in the p53 gene. Some p53 mutants are associated with poor prognosis in SCCHN patients. However, the molecular mechanisms that determine the poor outcome of cancers carrying p53 mutations are unknown. Here, we generated a mouse model for SCCHN and found that activation of the endogenous p53 gain-of-function mutation p53R172H, but not deletion of p53, cooperates with oncogenic K-ras during SCCHN initiation, accelerates oral tumour growth, and promotes progression to carcinoma. Mechanistically, expression profiling of the tumours that developed in these mice and studies using cell lines derived from these tumours determined that mutant p53 induces the expression of genes involved in mitosis, including cyclin B1 and cyclin A, and accelerates entry in mitosis. Additionally, we discovered that this oncogenic function of mutant p53 was dependent on K-ras because the expression of cyclin B1 and cyclin A decreased, and entry in mitosis was delayed, after suppressing K-ras expression in oral tumour cells that express p53R172H. The presence of double-strand breaks in the tumours suggests that oncogene-dependent DNA damage resulting from K-ras activation promotes the oncogenic function of mutant p53. Accordingly, DNA damage induced by doxorubicin also induced increased expression of cyclin B1 and cyclin A in cells that express p53R172H. These findings represent strong in vivo evidence for an oncogenic function of endogenous p53 gain-of-function mutations in SCCHN and provide a mechanistic explanation for the genetic interaction between oncogenic K-ras and mutant p53. PMID:21952947

Regulation of p53 tetramerization and nuclear export by ARC.

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Foo, Roger S-Y; Nam, Young-Jae; Ostreicher, Marc Jason; Metzl, Mark D; Whelan, Russell S; Peng, Chang-Fu; Ashton, Anthony W; Fu, Weimin; Mani, Kartik; Chin, Suet-Feung; Provenzano, Elena; Ellis, Ian; Figg, Nichola; Pinder, Sarah; Bennett, Martin R; Caldas, Carlos; Kitsis, Richard N

2007-12-26

Inactivation of the transcription factor p53 is central to carcinogenesis. Yet only approximately one-half of cancers have p53 loss-of-function mutations. Here, we demonstrate a mechanism for p53 inactivation by apoptosis repressor with caspase recruitment domain (ARC), a protein induced in multiple cancer cells. The direct binding in the nucleus of ARC to the p53 tetramerization domain inhibits p53 tetramerization. This exposes a nuclear export signal in p53, triggering Crm1-dependent relocation of p53 to the cytoplasm. Knockdown of endogenous ARC in breast cancer cells results in spontaneous tetramerization of endogenous p53, accumulation of p53 in the nucleus, and activation of endogenous p53 target genes. In primary human breast cancers with nuclear ARC, p53 is almost always WT. Conversely, nearly all breast cancers with mutant p53 lack nuclear ARC. We conclude that nuclear ARC is induced in cancer cells and negatively regulates p53.

Aggregation-primed molten globule conformers of the p53 core domain provide potential tools for studying p53C aggregation in cancer.

Science.gov (United States)

Pedrote, Murilo M; de Oliveira, Guilherme A P; Felix, Adriani L; Mota, Michelle F; Marques, Mayra de A; Soares, Iaci N; Iqbal, Anwar; Norberto, Douglas R; Gomes, Andre M O; Gratton, Enrico; Cino, Elio A; Silva, Jerson L

2018-05-31

The functionality of the tumor suppressor p53 is altered in more than 50% of human cancers, and many individuals with cancer exhibit amyloid-like buildups of aggregated p53. An understanding of what triggers the pathogenic amyloid conversion of p53 is required for the further development of cancer therapies. Here, perturbation of the p53 core domain (p53C) with sub-denaturing concentrations of guanidine hydrochloride and high hydrostatic pressure revealed native-like molten globule (MG) states, a subset of which were highly prone to amyloidogenic aggregation. We found that MG conformers of p53C, likely representing population-weighted averages of multiple states, have different volumetric properties, as determined by pressure perturbation and size-exclusion chromatography. We also found that they bind the fluorescent dye 4,4'-dianilino-1,1'-binaphthyl-5,5'-disulfonic acid (bis-ANS) and have a native-like tertiary structure that occludes the single Trp residue in p53. Fluorescence experiments revealed conformational changes of the single Trp and Tyr residues before p53 unfolding and the presence of MG conformers, some of which were highly prone to aggregation. P53C exhibited marginal unfolding cooperativity, which could be modulated from unfolding to aggregation pathways with chemical or physical forces. We conclude that trapping amyloid precursor states in solution is a promising approach for understanding p53 aggregation in cancer. Our findings support the use of single-Trp fluorescence as a probe for evaluating p53 stability, effects of mutations, and the efficacy of therapeutics designed to stabilize p53. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

Tumor hypoxia, p53, and prognosis in cervical cancers

International Nuclear Information System (INIS)

Haensgen, Gabriele; Krause, Ulf; Becker, Axel; Stadler, Peter; Lautenschlaeger, Christine; Wohlrab, Wolfgang; Rath, Friedrich W.; Molls, Michael; Dunst, Juergen

2001-01-01

Background: The p53 protein is involved in the regulation of initiation of apoptosis. In vitro, p53-deficient cells do not respond to hypoxia with apoptosis as do p53-normal cells, and this may lead to a relative growth advantage of cells without a functioning p53 under hypoxia. On the basis of this hypothesis, a selection of cells with a functionally inactive p53 may occur in hypoxic tumors. The development of uterine cervical carcinomas is closely associated with infections of human papilloma viruses, which may cause a degradation of the tumor suppressor gene p53, resulting in a restriction of apoptosis. Thus, cervical cancers have often a functionally inactive p53. The purpose of our clinical study was therefore to investigate the association between p53, hypoxia, and prognosis in cervical cancers in which the oxygenation status can be determined by clinical methods. Material and Methods: Seventy patients with locally advanced squamous cell cervical cancer Stages IIB (n=14), IIIB (n=49), and IVA (n=7) were investigated in the period from 1996 through 1999. All were treated with definitive radiotherapy with curative intent by a combination of external radiotherapy plus high-dose-rate afterloading. Before therapy, tumor oxygenation was measured with a needle probe polarographically using the Eppendorf histograph. Hypoxic tumors were defined as those with pO 2 measurements below 5 mm Hg (HF5). Pretreatment biopsies were taken and analyzed immunohistologically for p53 protein expression with the DO-7 antibody. The DNA index was measured by flow cytometry. The statistical data analysis was done with SPSS 9.0 for Windows. Results: The 3-year overall survival was 55% for the whole group of patients. Clinical prognostic factors in a multivariate analysis were pretreatment hemoglobin level (3-year survival 62% for patients with a pretreatment hemoglobin ≥11 g/dl vs. 27% for hemoglobin <11 g/dl, p=0.006) and FIGO stage (Stage IIB: 65%; Stage IIIB: 60%; Stage IVA: 29%, p

Papel neuroprotector da hipotermia terapêutica pós paragem cardio-respiratória

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Ana Abreu

2011-12-01

Full Text Available OBJECTIVOS: A hipotermia terapêutica demonstrou ter efeitos neuro e cardioprotectores, com melhoria da sobrevida e redução das sequelas neurológicas em doentes vítimas de paragem cardio-respiratória. O objectivo deste estudo foi avaliar a evolução dos doentes submetidos a hipotermia terapêutica após paragem cardio-respiratória. MÉTODOS: Estudo prospectivo observacional dos doentes submetidos a hipotermia terapêutica após paragem cardio-respiratória numa unidade de cuidados intensivos polivalente durante 10 meses. Aos doentes admitidos até 12 horas após paragem cardio-respiratória foi induzida a hipotermia terapêutica através da administração de fluidos arrefecidos e arrefecimento corporal externo e mantida a temperatura alvo, 33°C, durante 24 horas. RESULTADOS: Foram incluídos 12 doentes, idade (mediana de 64 anos, 58% do sexo masculino. A paragem cardio-respiratória ocorreu em meio hospitalar em 6 doentes. O índice de Charlson, o Sequential Organ Failure Assessment (SOFA e o Acute Physiology and Chronic Health Evaluation II, no primeiro dia, foram 2.9 [IIQ 6.8], 11 [IIQ 2.75], e 24.5 [IIQ 15.25], respectivamente. A taxa de mortalidade na unidade de cuidados intensivos polivalente foi de 42% (N=5. Dos 7 sobreviventes, 5 recuperaram o estado neurológico prévio à paragem cardio-respiratória. A hipotermia terapêutica foi iniciada cerca de 120 minutos [IIQ 78.75], após recuperação de circulação espontânea. A maioria dos doentes (75% necessitou de suporte vasopressor. Foi constatado, nos 3 dias subsequentes à paragem cardio-respiratória e hipotermia terapêutica, uma diminuição do valor mediano de SOFA (11[IIQ 2.75], no dia 0, 10 [IIQ 3], no dia 1 e 7 [IIQ 4.5], no dia 2. CONCLUSÃO: A aplicação de um protocolo de hipotermia terapêutica revelou ser simples e eficaz e permitiu obter em doentes com indicação, boa recuperação neurológica.

Analysis of p53- immunoreactivity in astrocytic brain tumors

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Shinkarenko T.V.

2016-12-01

Full Text Available P53 is an antioncogene with the frequently occured mutations in human tumor cells, leading to corresponding protein overexpression which can be detected by immunohistochemistry. Researches dedicated to the investigation of possibilities of using this technique gave controversial results. The authors investigated features of p53 protein expression in astrocytic brain tumors with different degrees of malignancy. Analyzed the relationship of the expression level of p53 by tumor cells with clinical parameters and Ki-67 proliferation index (PI as well. Tissues were collected from 52 cases with diagnosed astrocytic brain tumors. The sections were immunohistochemically stained with p53 and Ki-67. For each marker, 1000 tumor cells were counted and the ratio of positive tumor cells was calculated using software package ImageJ 1,47v. In normal brain tissue p53- expression was not identified. p53-immunoreactive tumor cells were detected in 25% (1/4 pilocytic astrocytomas, 33.3% (2/6 of diffuse astrocytomas, 53.8% (7/13 anaplastic astrocytomas, 58.6% (17/29 glioblastomas. A high proportion of p53-immunoreactive cells (> 30% was observed only in glioblastomas. The level of p53-imunoreactivity was not related to the age, gender and Grade WHO (p> 0,05. Spearman correlation coefficient between the relative quantity of ki-67- and p53-immunoreactive nuclei showed weak direct correlation (0.023, but the one was not statistically significant (p> 0,05. The level of p53-imunoreactivity is not dependent from age and sex of patients, Grade (WHO and proliferative activity (p>0,05 but the high level of p53-immunoreactive cells (>30% is found in glioblastoma specimens only, that may be due to the accumulation of mutations in DNA of tumor cells. There is insignificant weak relationship between relative quantities of ki-67- and p53-immunoreactive tumor cells (p>0,05.

Múltiplas Recidivas Oligometastáticas em Doente com Tumor de Pulmão Não-Pequenas Células

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Orlando Nunes

2017-09-01

Apresenta-se o caso de uma doente jovem, com recidiva de adenocarcinoma primário do pulmão oligoprogressiva, mas múltipla, na mama, pele e sistema nervoso central, dois, 12 e 27 meses após cirurgia curativa, tratada localmente com cirurgia e gamma knife, com longa sobrevivência e mantendo-se clinicamente assintomática. Recebido: 09/05/2017 - Aceite: 31/08/2017

The nucleolus directly regulates p53 export and degradation.

Science.gov (United States)

Boyd, Mark T; Vlatkovic, Nikolina; Rubbi, Carlos P

2011-09-05

The correlation between stress-induced nucleolar disruption and abrogation of p53 degradation is evident after a wide variety of cellular stresses. This link may be caused by steps in p53 regulation occurring in nucleoli, as suggested by some biochemical evidence. Alternatively, nucleolar disruption also causes redistribution of nucleolar proteins, potentially altering their interactions with p53 and/or MDM2. This raises the fundamental question of whether the nucleolus controls p53 directly, i.e., as a site where p53 regulatory processes occur, or indirectly, i.e., by determining the cellular localization of p53/MDM2-interacting factors. In this work, transport experiments based on heterokaryons, photobleaching, and micronucleation demonstrate that p53 regulatory events are directly regulated by nucleoli and are dependent on intact nucleolar structure and function. Subcellular fractionation and nucleolar isolation revealed a distribution of ubiquitylated p53 that supports these findings. In addition, our results indicate that p53 is exported by two pathways: one stress sensitive and one stress insensitive, the latter being regulated by activities present in the nucleolus.

Cardioplasty and Roux-en-Y partial gastrectomy (Serra-Dória procedure for reoperation of achalasia Cardioplastia e gastrectomia parcial em Y-de-Roux (operação de Serra-Dória para reoperações no megaesôfago

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Helio Ponciano

2004-09-01

period developed esophagitis.RACIONAL: Nas operações de cardiomiotomia para tratamento do megaesôfago ocorre recidiva dos sintomas em até 15% dos pacientes, sendo que alguns necessitam reoperação. OBJETIVO: Avaliar os resultados de reoperações através de cardioplastia e gastrectomia parcial em Y-de-Roux, conforme técnica proposta por Serra-Dória. CASUÍSTICA E MÉTODOS: Foram estudados de forma retrospectiva, 20 pacientes com megaesôfago previamente tratados por cardiomiotomia. A causa de recidiva dos sintomas foi esofagite de refluxo em nove (45,0%, miotomia incompleta em um (5,0%, cicatrização da miotomia em cinco (25,0% e presença de megaesôfago avançado em cinco (25.0%. Analisaram-se as complicações intra e pós-operatórias. Os pacientes foram avaliados sob o ponto de vista clínico (disfagia, regurgitação, pirose e variação de peso, radiológico e endoscópico, no pré e no pós-operatório imediato e tardio. RESULTADOS: Cinco (25,0% doentes apresentaram complicações no pós-operatório imediato. Não houve mortalidade. Todos os doentes melhoraram da disfagia, com quase total desaparecimento da regurgitação e pirose. Houve manutenção ou aumento de peso em 64,7% dos pacientes. O estudo radiológico mostrou diminuição do calibre do esôfago em 53,0% e manutenção nos demais. Não houve aumento do calibre em nenhum dos pacientes. No exame endoscópico realizado no pós-operatório tardio em 17 pacientes, observou-se que 6 entre 9 que apresentavam esofagite de refluxo, melhoraram; 2 entre 8, que apresentavam esôfago normal no pré-operatório, desenvolveram esofagite. CONCLUSÕES: A operação de Serra-Dória para tratamento do megaesôfago, operado por cardiomiotomia com recidiva dos sintomas, apresentou baixa morbidade e ausência de mortalidade. Permitiu expressivo alívio dos sintomas e diminuição do calibre do esôfago em vários doentes. Possibilitou, também, melhora da esofagite de refluxo, havendo, entretanto, a possibilidade

Immunohistochemical analysis of P53 protein in odontogenic cysts

Science.gov (United States)

Gaballah, Essam Taher M.A.; Tawfik, Mohamed A.

2010-01-01

The p53 is a well-known tumor suppressor gene, the mutations of which are closely related to the decreased differentiation of cells. Findings of studies on immunohistochemical P53 expression in odontogenic cysts are controversial. The present study was carried-out to investigate the immunohistochemical expression of P53 protein in odontogenic cysts. Thirty paraffin blocks of diagnosed odontogenic cysts were processed to determine the immunohistochemical expression of P53 protein. Nine of the 11 odontogenic keratocysts (81.8%) expressed P53, one of three dentigerous cyst cases expressed P53, while none of the 16 radicular cysts expressed P53 protein. The findings of the present work supported the reclassification of OKC as keratocystic odontogenic tumor. PMID:23960493

Knockout and transgenic mice of Trp53: what have we learned about p53 in breast cancer?

International Nuclear Information System (INIS)

Blackburn, Anneke C; Jerry, D Joseph

2002-01-01

The human p53 tumor suppressor gene TP53 is mutated at a high frequency in sporadic breast cancer, and Li-Fraumeni syndrome patients who carry germline mutations in one TP53 allele have a high incidence of breast cancer. In the 10 years since the first knockout of the mouse p53 tumor suppressor gene (designated Trp53) was published, much has been learned about the contribution of p53 to biology and tumor suppression in the breast through the use of p53 transgenic and knockout mice. The original mice deficient in p53 showed no mammary gland phenotype. However, studies using BALB/c-Trp53-deficient mice have demonstrated a delayed involution phenotype and a mammary tumor phenotype. Together with other studies of mutant p53 transgenes and p53 bitransgenics, a greater understanding has been gained of the role of p53 in involution, of the regulation of p53 activity by hormones, of the effect of mouse strain and modifier genes on tumor phenotype, and of the cooperation between p53 and other oncogenic pathways, chemical carcinogens and hormonal stimulation in mammary tumorigenesis. Both p53 transgenic and knockout mice are important in vivo tools for understanding breast cancer, and are yet to be exploited for developing therapeutic strategies in breast cancer

Estado da Arte dos Doentes com Cancro do Pulmão de Não Pequenas Células: Doença Avançada e Mutação EGFR Positiva

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Bárbara Parente

2018-02-01

Full Text Available O aparecimento de terapêuticas dirigidas, trouxe na última década uma enorme esperança para os doentes com cancro do pulmão. Os inibidores dos recetores do fator de crescimento epidérmico (EGFR, erlotinib e gefitinib (inibidores de tirosina quinase TKI, estiveram na vanguarda das mudanças da prática de tratamento para doença avançada do cancro do pulmão de não pequenas células (CPNPC, nos últimos 10 anos, com a descoberta de mutações EGFR que conferem sensibilidade a inibidores da tirosina quinase no CPNPC. O ano de 2004, marcou o início da era da medicina de precisão para o cancro do pulmão. Os estudos randomizados de fase III investigaram o papel de dois inibidores de EGFR-TKI, gefitinib e erlotinib, como tratamento de primeira linha em comparação com a quimioterapia à base de platina, em doentes com CPNPC doença avançada com mutações de ativação do EGFR. Um TKI de segunda geração (afatinib encontra-se já aprovado pela EMA com a mesma indicação após resultados dos clínicos do Lux Lung 3 e 6. No entanto, os doentes com mutação EGFR positiva, regra geral, progridem após 10-12 meses de tratamento, necessitando de novas opções terapêuticas. Inibidores de 3ª geração entretanto desenvolvidos (dirigidos à mutação de resistência do T790M, e outras, após rebiópsia, demostraram uma notável eficácia, em doentes já tratados e com um perfil de toxicidade ainda menor que os TKI de 1ª e 2ª geração. Recebido: 30/05/2016 - Aceite: 03/06/2016

Infection with E1B-mutant adenovirus stabilizes p53 but blocks p53 acetylation and activity through E1A

DEFF Research Database (Denmark)

Savelyeva, I.; Dobbelstein, M.

2011-01-01

to the suppression of p21 transcription. Depending on the E1A conserved region 3, E1B-defective adenovirus impaired the ability of the transcription factor Sp1 to bind the p21 promoter. Moreover, the amino terminal region of E1A, binding the acetyl transferases p300 and CREB-binding protein, blocked p53 K382...... accumulation of p53, without obvious defects in p53 localization, phosphorylation, conformation and oligomerization. Nonetheless, p53 completely failed to induce its target genes in this scenario, for example, p21/CDKN1A, Mdm2 and PUMA. Two regions of the E1A gene products independently contributed...... acetylation in infected cells. Mutating either of these E1A regions, in addition to E1B, partially restored p21 mRNA levels. Our findings argue that adenovirus attenuates p53-mediated p21 induction, through at least two E1B-independent mechanisms. Other virus species and cancer cells may employ analogous...

p53 downregulates the Fanconi anaemia DNA repair pathway.

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Jaber, Sara; Toufektchan, Eléonore; Lejour, Vincent; Bardot, Boris; Toledo, Franck

2016-04-01

Germline mutations affecting telomere maintenance or DNA repair may, respectively, cause dyskeratosis congenita or Fanconi anaemia, two clinically related bone marrow failure syndromes. Mice expressing p53(Δ31), a mutant p53 lacking the C terminus, model dyskeratosis congenita. Accordingly, the increased p53 activity in p53(Δ31/Δ31) fibroblasts correlated with a decreased expression of 4 genes implicated in telomere syndromes. Here we show that these cells exhibit decreased mRNA levels for additional genes contributing to telomere metabolism, but also, surprisingly, for 12 genes mutated in Fanconi anaemia. Furthermore, p53(Δ31/Δ31) fibroblasts exhibit a reduced capacity to repair DNA interstrand crosslinks, a typical feature of Fanconi anaemia cells. Importantly, the p53-dependent downregulation of Fanc genes is largely conserved in human cells. Defective DNA repair is known to activate p53, but our results indicate that, conversely, an increased p53 activity may attenuate the Fanconi anaemia DNA repair pathway, defining a positive regulatory feedback loop.

N-methylpurine DNA glycosylase inhibits p53-mediated cell cycle arrest and coordinates with p53 to determine sensitivity to alkylating agents.

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Song, Shanshan; Xing, Guichun; Yuan, Lin; Wang, Jian; Wang, Shan; Yin, Yuxin; Tian, Chunyan; He, Fuchu; Zhang, Lingqiang

2012-08-01

Alkylating agents induce genome-wide base damage, which is repaired mainly by N-methylpurine DNA glycosylase (MPG). An elevated expression of MPG in certain types of tumor cells confers higher sensitivity to alkylation agents because MPG-induced apurinic/apyrimidic (AP) sites trigger more strand breaks. However, the determinant of drug sensitivity or insensitivity still remains unclear. Here, we report that the p53 status coordinates with MPG to play a pivotal role in such process. MPG expression is positive in breast, lung and colon cancers (38.7%, 43.4% and 25.3%, respectively) but negative in all adjacent normal tissues. MPG directly binds to the tumor suppressor p53 and represses p53 activity in unstressed cells. The overexpression of MPG reduced, whereas depletion of MPG increased, the expression levels of pro-arrest gene downstream of p53 including p21, 14-3-3σ and Gadd45 but not proapoptotic ones. The N-terminal region of MPG was specifically required for the interaction with the DNA binding domain of p53. Upon DNA alkylation stress, in p53 wild-type tumor cells, p53 dissociated from MPG and induced cell growth arrest. Then, AP sites were repaired efficiently, which led to insensitivity to alkylating agents. By contrast, in p53-mutated cells, the AP sites were repaired with low efficacy. To our knowledge, this is the first direct evidence to show that a DNA repair enzyme functions as a selective regulator of p53, and these findings provide new insights into the functional linkage between MPG and p53 in cancer therapy.

Expression of Androgen Receptor Is Negatively Regulated By p53

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Fatouma Alimirah

2007-12-01

Full Text Available Increased expression of androgen receptor (AR in prostate cancer (PC is associated with transition to androgen independence. Because the progression of PC to advanced stages is often associated with the loss of p53 function, we tested whether the p53 could regulate the expression of AR gene. Here we report that p53 negatively regulates the expression of AR in prostate epithelial cells (PrECs. We found that in LNCaP human prostate cancer cells that express the wild-type p53 and AR and in human normal PrECs, the activation of p53 by genotoxic stress or by inhibition of p53 nuclear export downregulated the expression of AR. Furthermore, forced expression of p53 in LNCaP cells decreased the expression of AR. Conversely, knockdown of p53 expression in LNCaP cells increased the AR expression. Consistent with the negative regulation of AR expression by p53, the p53-null HCT116 cells expressed higher levels of AR compared with the isogenic HCT116 cells that express the wildtype p53. Moreover, we noted that in etoposide treated LNCaP cells p53 bound to the promoter region of the AR gene, which contains a potential p53 DNA-binding consensus sequence, in chromatin immunoprecipitation assays. Together, our observations provide support for the idea that the loss of p53 function in prostate cancer cells contributes to increased expression of AR.

[Punish or cherish: p53, metabolism and tumor suppression].

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Albagli, Olivier

2015-10-01

The p53 gene is essential for tumor suppression, but how it does so remains unclear. Upon genotoxic or oncogenic stresses, increased p53 activity induces transient cell cycle arrest, senescence or apoptosis, the three cornerstones of the so-called triumvirate. Accordingly, it has long been thought that p53 suppresses tumorigenesis by somehow counteracting cell proliferation or survival. However, several recently described genetically modified mice indicate that p53 can suppress tumorigenesis without triggering these three responses. Rather, as an important mechanism for tumor suppression, these mutant mice point to the ability of p53 to prevent the Warburg effect, that is to dampen glycolysis and foster mitochondrial respiration. Interestingly, these metabolic functions of p53 rely, in part, on its "unstressed" (basal) expression, a feature shared by its mechanistically linked anti-oxydant function. Together, these "conservative" activities of p53 may prevent tumor initiation by promoting and maintaining a normal oxidative metabolism and hence underly the "daily" tumor suppression by p53 in most cells. Conversely, destructive activities elicited by high p53 levels and leading to senescence or apoptosis provide a shield against partially or overtly transformed cells. This last situation, although relatively infrequent throughout life, is usual in experimental settings, which could explain the disproportionally high number of data implicating the triumvirate in tumor suppression by p53. © 2015 médecine/sciences – Inserm.

p53-competent cells and p53-deficient cells display different susceptibility to oxygen functionalized graphene cytotoxicity and genotoxicity.

Science.gov (United States)

Petibone, Dayton M; Mustafa, Thikra; Bourdo, Shawn E; Lafont, Andersen; Ding, Wei; Karmakar, Alokita; Nima, Zeid A; Watanabe, Fumiya; Casciano, Daniel; Morris, Suzanne M; Dobrovolsky, Vasily N; Biris, Alexandru S

2017-11-01

Due to the distinctive physical, electrical, and chemical properties of graphene nanomaterials, numerous efforts pursuing graphene-based biomedical and industrial applications are underway. Oxidation of pristine graphene surfaces mitigates its otherwise hydrophobic characteristic thereby improving its biocompatibility and functionality. Yet, the potential widespread use of oxidized graphene derivatives raises concern about adverse impacts on human health. The p53 tumor suppressor protein maintains cellular and genetic stability after toxic exposures. Here, we show that p53 functional status correlates with oxygen functionalized graphene (f-G) cytotoxicity and genotoxicity in vitro. The f-G exposed p53-competent cells, but not p53-deficient cells, initiated G 0 /G 1 phase cell cycle arrest, suppressed reactive oxygen species, and entered apoptosis. There was p53-dependent f-G genotoxicity evident as increased structural chromosome damage, but not increased gene mutation or chromatin loss. In conclusion, the cytotoxic and genotoxic potential for f-G in exposed cells was dependent on the p53 functional status. These findings have broad implications for the safe and effective implementation of oxidized graphene derivatives into biomedical and industrial applications. Published 2017. This article has been contributed to by US Government employees and their work is in the public domain in the USA. Published 2017. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

Mutations in p53, p53 protein overexpression and breast cancer survival

Czech Academy of Sciences Publication Activity Database

Rössner ml., Pavel; Gammon, M. D.; Zhang, Y.J.; Terry, M. B.; Hibshoosh, H.; Memeo, L.; Mansukhani, M.; Long, CH.M.; Gabrowski, G.; Agrawal, M.; Kalra, T.S.; Teitelbaum, S. L.; Neugut, A. I.; Santella, R. M.

2009-01-01

Roč. 13, č. 9B (2009), s. 3847-3857 ISSN 1582-1838 Institutional research plan: CEZ:AV0Z50390512 Keywords : Breast cancer * p53 mutations * Survival Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 5.228, year: 2009

Mutant p53 protein localized in the cytoplasm inhibits autophagy.

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Morselli, Eugenia; Tasdemir, Ezgi; Maiuri, Maria Chiara; Galluzzi, Lorenzo; Kepp, Oliver; Criollo, Alfredo; Vicencio, José Miguel; Soussi, Thierry; Kroemer, Guido

2008-10-01

The knockout, knockdown or chemical inhibition of p53 stimulates autophagy. Moreover, autophagy-inducing stimuli such as nutrient depletion, rapamycin or lithium cause the depletion of cytoplasmic p53, which in turn is required for the induction of autophagy. Here, we show that retransfection of p53(-/-) HCT 116 colon carcinoma cells with wild type p53 decreases autophagy down to baseline levels. Surprisingly, one third among a panel of 22 cancer-associated p53 single amino acid mutants also inhibited autophagy when transfected into p53(-/-) cells. Those variants of p53 that preferentially localize to the cytoplasm effectively repressed autophagy, whereas p53 mutants that display a prominently nuclear distribution failed to inhibit autophagy. The investigation of a series of deletion mutants revealed that removal of the DNA-binding domain from p53 fails to interfere with its role in the regulation of autophagy. Altogether, these results identify the cytoplasmic localization of p53 as the most important feature for p53-mediated autophagy inhibition. Moreover, the structural requirements for the two biological activities of extranuclear p53, namely induction of apoptosis and inhibition of autophagy, are manifestly different.

Existe diferença no estadiamento entre doentes operados de câncer colorretal no sistema previdenciário e na clinica privada?

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Rodrigo Cuiabano Paes Leme

Full Text Available OBJETIVO: Avaliar se existe diferença no estadiamento de doentes submetidos à ressecção intestinal por câncer colorretal no sistema previdenciário e na clínica privada. MÉTODO: Foram estudados de forma retrospectiva 41 doentes (16 homens e 25 mulheres com idade média de 59,4 anos operados no sistema previdenciário (SP e 33 doentes (18 homens e 15 mulheres com idade média de 60,8 anos operados na clínica privada (CP. Foram avaliados o estadiamento TNM, a frequência de operações de urgência, de operações paliativas e do uso de colostomia. RESULTADOS: Não se observou diferença entre o estadiamento dos dois grupos. A frequência de operações de urgência foi 26,8% no SP e 12,1% na CP (p=0,100. As operações paliativas ( 19,5% SP x 6,1% CP e o uso de colostomia ( 26,8 SP X 15,2 CP foram maiores no sistema previdenciário porém os valores não foram estatisticamente significantes, valores de p=0,087 e p=0,352 respectivamente. CONCLUSÃO: Não há diferença significante entre o estadiamento TNM de doentes operados no sistema previdenciário e privado.

The genetic alteration of p53 in esophageal cancer

Energy Technology Data Exchange (ETDEWEB)

Cho, Jae Il; Baik, Hee Jong; Kim, Chang Min; Kim, Mi Hee [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

1996-01-01

Genetic alterations in the p53 gene have been detected in various human malignancies, and its alterations inactive the function of p53 as a tumor suppressor. Point mutation and gene deletion are the main mechanisms of p53 inactivation. To determine the incidence of genetic alteration of p53 and their clinical implications in Korean patients of esophageal cancer, we investigated p53 alterations in 26 esophageal cancer tissues paired with its normal tissue by Southern blot analysis, PCR-SSCP, and direct sequencing. Allelic loss of chromosome 17p occurred in 12 out of 21 informative cases(57%) by Southern blot analysis, and 16 cases showed mobility shift in PCR-SSCP, so overall incidence of p53 gene alterations was 77%(20/26). The mutations detected was randomly dispersed over exon4-8 and was frequently G-T transversion and C:T transitions. Three identical mutations were clustered at codon 213 suggested the same etiologic agents in this cases. The p53 gene alterations play a significant role in the development of esophageal cancers, however, no relationship between p53 mutation and clinical data was detected so far. 9 refs. (Author).

Tobacco, alcohol, and p53 overexpression in early colorectal neoplasia

International Nuclear Information System (INIS)

Terry, Mary Beth; Neugut, Alfred I; Mansukhani, Mahesh; Waye, Jerome; Harpaz, Noam; Hibshoosh, Hanina

2003-01-01

The p53 tumor suppressor gene is commonly mutated in colorectal cancer. While the effect of p53 mutations on colorectal cancer prognosis has been heavily studied, less is known about how epidemiologic risk factors relate to p53 status, particularly in early colorectal neoplasia prior to clinically invasive colorectal cancer (including adenomas, carcinoma in situ (CIS), and intramucosal carcinoma). We examined p53 status, as measured by protein overexpression, in 157 cases with early colorectal neoplasia selected from three New York City colonoscopy clinics. After collecting paraffin-embedded tissue blocks, immunohistochemistry was performed using an anti-p53 monoclonal mouse IgG 2 a [BP53-12-1] antibody. We analyzed whether p53 status was different for risk factors for colorectal neoplasia relative to a polyp-free control group (n = 508). p53 overexpression was found in 10.3%, 21.7%, and 34.9%, of adenomatous polyps, CIS, and intramucosal cases, respectively. Over 90% of the tumors with p53 overexpression were located in the distal colon and rectum. Heavy cigarette smoking (30+ years) was associated with cases not overexpressing p53 (OR = 1.8, 95% CI = 1.1–2.9) but not with those cases overexpressing p53 (OR = 1.0, 95% CI = 0.4–2.6). Heavy beer consumption (8+ bottles per week) was associated with cases overexpressing p53 (OR = 4.0, 95% CI = 1.3–12.0) but not with cases without p53 overexpression (OR = 1.6, 95% CI = 0.7–3.7). Our findings that p53 overexpression in early colorectal neoplasia may be positively associated with alcohol intake and inversely associated with cigarette smoking are consistent with those of several studies of p53 expression and invasive cancer, and suggest that there may be relationships of smoking and alcohol with p53 early in the adenoma to carcinoma sequence

Estudo das mutações C282Y, H63D e S65C do gene HFE em doentes brasileiros com sobrecarga de ferro Study of C282Y, H63D and S65C mutations in the HFE gene in Brazilian patients with iron overload

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Rodolfo D. Cançado

2007-12-01

Full Text Available Hemocromatose é uma das doenças genéticas mais freqüentes no ser humano e uma das causas mais importantes de sobrecarga de ferro. Os objetivos deste estudo foram determinar a freqüência das mutações C282Y, H63D e S65C do gene HFE em doentes brasileiros com sobrecarga de ferro, verificar a coexistência de anemia hemolítica hereditária, hepatite C e consumo excessivo de bebida alcoólica nestes doentes e avaliar a influência destas variáveis sobre os depósitos de ferro do organismo. Saturação da transferrina, ferritina sérica e análise das mutações C282Y, H63D e S65C do gene HFE, pelo método da PCR, foram determinadas em cinqüenta doentes com sobrecarga de ferro atendidos no Hemocentro da Santa Casa de São Paulo entre janeiro de 2000 e maio de 2004. A freqüência de mutação do gene HFE nos doentes com sobrecarga de ferro foi de 76,0% (38/50. Saturação da transferrina e ferritina foram significativamente maiores nos doentes homozigotos para a mutação C282Y confirmando a correlação entre genótipo C282Y/C282Y e maior risco de sobrecarga de ferro. A coexistência de hepatite C, consumo excessivo de bebida alcoólica ou anemia hemolítica hereditária estão implicados em aumento dos estoques de ferro e constituem fator de risco adicional em pacientes com mutação do gene HFE para a condição de sobrecarga de ferro.Hemochromatosis is one of the most frequent genetic diseases in humans and one of the most important causes of iron overload. The aims of this study were to determine the frequency of C282Y, H63D and S65C mutations of the HFE gene in Brazilian patients with iron overload, to verify the coexistence of chronic hemolytic anemia, hepatitis C and excessive alcohol consumption and to evaluate the influence of these variables on body iron deposits. Transferrin saturation, serum ferritin and C282Y, H63D and S65C HFE gene mutations (by PCR method were determined in 50 patients with iron overload in the Hemocentro da

Hormonal control of p53 and chemoprevention

International Nuclear Information System (INIS)

Jerry, D Joseph; Minter, Lisa M; Becker, Klaus A; Blackburn, Anneke C

2002-01-01

Improvements in the detection and treatment of breast cancer have dramatically altered its clinical course and outcome. However, prevention of breast cancer remains an elusive goal. Parity, age of menarche, and age at menopause are major risk factors drawing attention to the important role of the endocrine system in determining the risk of breast cancer, while heritable breast cancer susceptibility syndromes have implicated tumor suppressor genes as important targets. Recent work demonstrating hormonal modulation of the p53 tumor suppressor pathway draws together these established determinants of risk to provide a model of developmental susceptibility to breast cancer. In this model, the mammary epithelium is rendered susceptible due to impaired p53 activity during specific periods of mammary gland development, but specific endocrine stimuli serve to activate p53 function and to mitigate this risk. The results focus attention on p53 as a molecular target for therapies to reduce the risk of breast cancer

Casuística de uma unidade de Ortogeriatria

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Mónica Brinquinho

2017-12-01

Full Text Available A fratura do fémur está associada a importante morbimortalidade, sendo que menos de metade dos doentes regressam ao seu nível prévio de autonomia. Uma abordagem multidisciplinar permite uma reabilitação funcional imediata, bem como melhor gestão de comorbilidades, prevenção de fraturas secundárias e das quedas. Objetivos: apresentação da casuística de 3 meses de uma unidade de Ortogeriatria. Material e métodos: Descreve-se a demografia dos doentes admitidos, grau de dependência funcional, comorbilidades, intercorrências, tempo de internamento, mortalidade e destino à data de alta. O ganho de funcionalidade no internamento foi também avaliado. Resultados: De outubro/2015 a janeiro/2016 foram admitidos 66 doentes após cirurgia de fratura proximal do fémur. Média de idades foi 82,94±6,93 anos; 86% eram mulheres. O tempo de internamento foi de 7,8±4,68 dias, sendo o tempo médio para realizar cirurgia de 3±3,37 dias. Quanto ao grau de funcionalidade prévio 47% eram Katz A; à admissão 85% tinham mRankin ≤3. Identificaram-se várias comorbilidades em 89% dos doentes; nas intercorrências, a mais frequente foi a anemia (53%. Houve um ganho na funcionalidade relativamente à admissão na unidade de 75,8% e em relação ao estado funcional anterior ao evento de 19,7%. Setenta e um porcento dos doentes tiveram alta para o domicílio; a taxa de mortalidade foi de 1,52%. Conclusões: A unidade demonstrou eficiência no controlo das comorbilidades, reduzidas complicações e baixa mortalidade. Registou-se um ganho funcional comparando com a admissão em 3 em cada 4 doentes e em relação ao estado basal prévio em 1 em cada 5 doentes.

Friend or Foe: MicroRNAs in the p53 network.

Science.gov (United States)

Luo, Zhenghua; Cui, Ri; Tili, Esmerina; Croce, Carlo

2018-04-10

The critical tumor suppressor gene TP53 is either lost or mutated in more than half of human cancers. As an important transcriptional regulator, p53 modulates the expression of many microRNAs. While wild-type p53 uses microRNAs to suppress cancer development, microRNAs that are activated by gain-of-function mutant p53 confer oncogenic properties. On the other hand, the expression of p53 is tightly controlled by a fine-tune machinery including microRNAs. MicroRNAs can target the TP53 gene directly or other factors in the p53 network so that expression and function of either the wild-type or the mutant forms of p53 is downregulated. Therefore, depending on the wild-type or mutant p53 context, microRNAs contribute substantially to suppress or exacerbate tumor development. Copyright © 2018. Published by Elsevier B.V.

Comparação das contagens das células de Langerhans de tecidos contendo carcinoma anal em doentes com e sem infecção pelo HIV Comparison of Langerhans cells counts from tissues containing anal carcinoma of patients with and without HIV infection

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Sidney Roberto Nadal

2006-09-01

Full Text Available INTRODUÇÃO: As células de Langerhans (LC são derivadas da medula óssea e constituem-se nas principais apresentadoras de antígeno da pele.conferindo desta forma, a resposta imune cutânea. Seu número está reduzido nos imunodeprimidos, incluindo na infecção pelo HIV, e a presença do tumor inibe sua migração, impedindo que os linfócitos T promovam regressão das células neoplásicas. OBJETIVO: Conhecer as diferenças entre as contagens de LC no tecido tumoral de doentes de carcinomas anais com e sem AIDS. MÉTODO: Avaliamos 24 doentes, sendo 14 com HIV e 10 outros sem HIV . O tratamento para o carcinoma foi semelhante nos dois grupos. Cortes retirados de blocos parafinados submetidos ao teste imunoistoquímico com anticorpo anti-CD68. Contamos as LC com método da histometria e os comparamos aos números obtidos com amostras previamente conhecidas de doentes sem doença infecciosa anorretal ou infecção pelo HIV. Revisamos também a evolução e as contagens séricas de linfócitos T CD4+ de doentes HIV-positivos. RESULTADOS: Observamos que o carcinoma anal foi mais freqüente em mulheres HIV-negativas e em homens HIV-positivos e que esses ultimos eram mais jovens. As LC foram menos numerosas nos doentes HIV-positivos e as maiores contagens estavam associadas com pior evolução. Os doentes HIV-positivos com os níveis mais baixos de linfócitos T CD4+ também tiveram as piores evoluções. CONCLUSÃO: Concluímos que as LC estavam diminuídas nos doentes HIV-positivos, portadores de carcinoma anal, quando comparados aos soronegativos.Langerhans cells (LC are bone marrow derived dendritic cells that represent the major antigen-presenting cells (APC in the skin, thus representing an integral part of the cutaneous immune response. Immunossupression decreases their number, including HIV infection, and skin tumors products are sufficient to immobilize LC within the tumor, preventing their migration to lymph nodes. This reduces the

A dual role of p53 in the control of autophagy.

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Tasdemir, Ezgi; Chiara Maiuri, M; Morselli, Eugenia; Criollo, Alfredo; D'Amelio, Marcello; Djavaheri-Mergny, Mojgan; Cecconi, Francesco; Tavernarakis, Nektarios; Kroemer, Guido

2008-08-01

Genotoxic stress can induce autophagy in a p53-dependent fashion and p53 can transactivate autophagy-inducing genes. We have observed recently that inactivation of p53 by deletion, depletion or inhibition can trigger autophagy. Thus, human and mouse cells subjected to knockout, knockdown or pharmacological inhibition of p53 manifest signs of autophagy such as depletion of p62/SQSTM1, LC3 lipidation, redistribution of GFP-LC3 in cytoplasmic puncta, and accumulation of autophagosomes and autolysosomes, both in vitro and in vivo. Inhibition of p53 causes autophagy in enucleated cells, indicating that the cytoplasmic, non-nuclear pool of p53 can regulate autophagy. Accordingly, retransfection of p53(-/-) cells with wild-type p53 as well as a p53 mutant that is excluded from the nucleus (due to the deletion of the nuclear localization sequence) can inhibit autophagy, whereas retransfection with a nucleus-restricted p53 mutant (in which the nuclear localization sequence has been deleted) does not inhibit autophagy. Several distinct autophagy inducers (e.g., starvation, rapamycin, lithium, tunicamycin and thapsigargin) stimulate the rapid degradation of p53. In these conditions, inhibition of the p53-specific E3 ubiquitin ligase HDM2 can avoid p53 depletion and simultaneously prevent the activation of autophagy. Moreover, a p53 mutant that lacks the HDM2 ubiquitinylation site and hence is more stable than wild-type p53 is particularly efficient in suppressing autophagy. In conclusion, p53 plays a dual role in the control of autophagy. On the one hand, nuclear p53 can induce autophagy through transcriptional effects. On the other hand, cytoplasmic p53 may act as a master repressor of autophagy.

Combining Oncolytic Virotherapy with p53 Tumor Suppressor Gene Therapy

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Christian Bressy

2017-06-01

Full Text Available Oncolytic virus (OV therapy utilizes replication-competent viruses to kill cancer cells, leaving non-malignant cells unharmed. With the first U.S. Food and Drug Administration-approved OV, dozens of clinical trials ongoing, and an abundance of translational research in the field, OV therapy is poised to be one of the leading treatments for cancer. A number of recombinant OVs expressing a transgene for p53 (TP53 or another p53 family member (TP63 or TP73 were engineered with the goal of generating more potent OVs that function synergistically with host immunity and/or other therapies to reduce or eliminate tumor burden. Such transgenes have proven effective at improving OV therapies, and basic research has shown mechanisms of p53-mediated enhancement of OV therapy, provided optimized p53 transgenes, explored drug-OV combinational treatments, and challenged canonical roles for p53 in virus-host interactions and tumor suppression. This review summarizes studies combining p53 gene therapy with replication-competent OV therapy, reviews preclinical and clinical studies with replication-deficient gene therapy vectors expressing p53 transgene, examines how wild-type p53 and p53 modifications affect OV replication and anti-tumor effects of OV therapy, and explores future directions for rational design of OV therapy combined with p53 gene therapy.

The role of p53 and pRB in apoptosis and cancer

DEFF Research Database (Denmark)

Hickman, Emma S; Moroni, M Cristina; Helin, Kristian

2002-01-01

Loss of function of both the p53 pathway and the retinoblastoma protein (pRB) pathway plays a significant role in the development of most human cancers. Loss of pRB results in deregulated cell proliferation and apoptosis, whereas loss of p53 desensitizes cells to checkpoint signals, including...

CLCA2 as a p53-Inducible Senescence Mediator

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Chizu Tanikawa

2012-02-01

Full Text Available p53 is a tumor suppressor gene that is frequently mutated in multiple cancer tissues. Activated p53 protein regulates its downstream genes and subsequently inhibits malignant transformation by inducing cell cycle arrest, apoptosis, DNA repair, and senescence. However, genes involved in the p53-mediated senescence pathway are not yet fully elucidated. Through the screening of two genome-wide expression profile data sets, one for cells in which exogenous p53 was introduced and the other for senescent fibroblasts, we have identified chloride channel accessory 2 (CLCA2 as a p53-inducible senescence-associated gene. CLCA2 was remarkably induced by replicative senescence as well as oxidative stress in a p53-dependent manner. We also found that ectopically expressed CLCA2 induced cellular senescence, and the down-regulation of CLCA2 by small interfering RNA caused inhibition of oxidative stress-induced senescence. Interestingly, the reduced expression of CLCA2 was frequently observed in various kinds of cancers including prostate cancer, whereas its expression was not affected in precancerous prostatic intraepithelial neoplasia. Thus, our findings suggest a crucial role of p53/CLCA2-mediated senescence induction as a barrier for malignant transformation.

Targeting p53 by small molecules in hematological malignancies

OpenAIRE

Saha, Manujendra N; Qiu, Lugui; Chang, Hong

2013-01-01

p53 is a powerful tumor suppressor and is an attractive cancer therapeutic target. A breakthrough in cancer research came from the discovery of the drugs which are capable of reactivating p53 function. Most anti-cancer agents, from traditional chemo- and radiation therapies to more recently developed non-peptide small molecules exert their effects by enhancing the anti-proliferative activities of p53. Small molecules such as nutlin, RITA, and PRIMA-1 that can activate p53 have shown their ant...

Actinomycin D synergistically enhances the cytotoxicity of CDDP on KB cells by activating P53 via decreasing P53-MDM2 complex.

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Wang, Lin; Pang, Xiao-Cong; Yu, Zi-Ru; Yang, Sheng-Qian; Liu, Ai-Lin; Wang, Jin-Hua; Du, Guan-Hua

2017-06-01

The aim of this study is to investigate the synergism of low dose of actinomycin D (LDActD) to the cytotoxicity of cisplatin (CDDP) on KB cells. The role of P53 reactivation by LDActD in the synergism and its mechanism were further studied. Cell viability was determined by MTT assay. Apoptosis was determined by AnnexinV-FITC/PI staining. Mitochondrial membrane potential (MMP) was detected by JC-1 staining. Expression of proteins was detected by Western blotting (WB) and/or immunofluorescence (IF). Molecular docking of actinomycin D (ACTD) to Mouse double minute 2 homolog (MDM2) and Mouse double minute 2 homolog X (MDMX). MDMX was analyzed by Discovery Studio. The content of P53-MDM2 complex was detected by ELISA assay. The cytotoxicity of CDDP was increased by the combination of LDActD in kinds of cancer cells. Molecular docking showed strong interaction between ACTD and MDM2/MDMX. Meanwhile, LDActD significantly decreased P53-MDM2 complex. Significant increase of the apoptotic activity by the combination therapy in KB cells is P53 upregulated modulator of apoptosis (PUMA) dependent. In addition to the decrease in MMP, LDActD increased P53 regulated protein and decreased BCL-XL in KB cells. LDActD efficiently enhanced the cytotoxicity of CDDP in cancer cells and induced P53-PUMA-dependent and mitochondria-mediated apoptosis in KB cells. The reactivation of P53 was probably achieved by disturbing the interaction of P53 and MDM2/MDMX.

Knockdown of p53 suppresses Nanog expression in embryonic stem cells

Energy Technology Data Exchange (ETDEWEB)

Abdelalim, Essam Mohamed, E-mail: emohamed@qf.org.qa [Qatar Biomedical Research Institute, Qatar Foundation, Doha 5825 (Qatar); Molecular Neuroscience Research Center, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga 520-2192 (Japan); Department of Cytology and Histology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia (Egypt); Tooyama, Ikuo [Molecular Neuroscience Research Center, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga 520-2192 (Japan)

2014-01-10

Highlights: •We investigate the role of p53 in ESCs in the absence of DNA damage. •p53 knockdown suppresses ESC proliferation. •p53 knockdown downregulates Nanog expression. •p53 is essential for mouse ESC self-renewal. -- Abstract: Mouse embryonic stem cells (ESCs) express high levels of cytoplasmic p53. Exposure of mouse ESCs to DNA damage leads to activation of p53, inducing Nanog suppression. In contrast to earlier studies, we recently reported that chemical inhibition of p53 suppresses ESC proliferation. Here, we confirm that p53 signaling is involved in the maintenance of mouse ESC self-renewal. RNA interference-mediated knockdown of p53 induced downregulation of p21 and defects in ESC proliferation. Furthermore, p53 knockdown resulted in a significant downregulation in Nanog expression at 24 and 48 h post-transfection. p53 knockdown also caused a reduction in Oct4 expression at 48 h post-transfection. Conversely, exposure of ESCs to DNA damage caused a higher reduction of Nanog expression in control siRNA-treated cells than in p53 siRNA-treated cells. These data show that in the absence of DNA damage, p53 is required for the maintenance of mouse ESC self-renewal by regulating Nanog expression.

Infecção pulmonar por rhodococcus equi em doente vih+ - revisão baseada num caso clínico

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João Faria

2013-03-01

Full Text Available Apesar do aumento no número de casos de infecção humana por Rhodococcus equi (R. equi registado nas últimas décadas, sobretudo em indivíduos infectados pelo vírus da imunodeficiência humana (VIH, esse diagnóstico permanece uma raridade. Os autores apresentam um caso de infecção pulmonar por R. equi num homem de 36 anos com síndrome de imunodeficiência adquirida (SIDA. A doença manifestou-se de forma insidiosa, apresentando-se radiologicamente sob a forma de lesão pulmonar esquerda com cavitação e nível hidroaéreo, tendo sido inicialmente colocada a hipótese diagnóstica de tuberculose pulmonar (TP dada a pesquisa de bacilos álcool-ácido resistentes (BAAR na expectoração ter sido positiva. Posteriormente, foi possível isolar o R. equi nas culturas de expectoração e lavado broncoalveolar (LBA. O estudo anátomo-patológico confirmou a presença concomitante de malacoplaquia pulmonar. O doente cumpriu antibioterapia dirigida ao agente e teve boa evolução clínica, analítica e radiológica. A propósito deste caso, os autores fazem uma revisão teórica do tema à luz dos conhecimentos actuais.

Regulation of Metabolic Activity by p53

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Jessica Flöter

2017-05-01

Full Text Available Metabolic reprogramming in cancer cells is controlled by the activation of multiple oncogenic signalling pathways in order to promote macromolecule biosynthesis during rapid proliferation. Cancer cells also need to adapt their metabolism to survive and multiply under the metabolically compromised conditions provided by the tumour microenvironment. The tumour suppressor p53 interacts with the metabolic network at multiple nodes, mostly to reduce anabolic metabolism and promote preservation of cellular energy under conditions of nutrient restriction. Inactivation of this tumour suppressor by deletion or mutation is a frequent event in human cancer. While loss of p53 function lifts an important barrier to cancer development by deleting cell cycle and apoptosis checkpoints, it also removes a crucial regulatory mechanism and can render cancer cells highly sensitive to metabolic perturbation. In this review, we will summarise the major concepts of metabolic regulation by p53 and explore how this knowledge can be used to selectively target p53 deficient cancer cells in the context of the tumour microenvironment.

Post-translational regulation enables robust p53 regulation.

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Shin, Yong-Jun; Chen, Kai-Yuan; Sayed, Ali H; Hencey, Brandon; Shen, Xiling

2013-08-30

The tumor suppressor protein p53 plays important roles in DNA damage repair, cell cycle arrest and apoptosis. Due to its critical functions, the level of p53 is tightly regulated by a negative feedback mechanism to increase its tolerance towards fluctuations and disturbances. Interestingly, the p53 level is controlled by post-translational regulation rather than transcriptional regulation in this feedback mechanism. We analyzed the dynamics of this feedback to understand whether post-translational regulation provides any advantages over transcriptional regulation in regard to disturbance rejection. When a disturbance happens, even though negative feedback reduces the steady-state error, it can cause a system to become less stable and transiently overshoots, which may erroneously trigger downstream reactions. Therefore, the system needs to balance the trade-off between steady-state and transient errors. Feedback control and adaptive estimation theories revealed that post-translational regulation achieves a better trade-off than transcriptional regulation, contributing to a more steady level of p53 under the influence of noise and disturbances. Furthermore, post-translational regulation enables cells to respond more promptly to stress conditions with consistent amplitude. However, for better disturbance rejection, the p53- Mdm2 negative feedback has to pay a price of higher stochastic noise. Our analyses suggest that the p53-Mdm2 feedback favors regulatory mechanisms that provide the optimal trade-offs for dynamic control.

Role of Tumor Suppressor P53 in Megakaryopoiesis and Platelet Function

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Apostolidis, Pani A.; Woulfe, Donna S.; Chavez, Massiel; Miller, William M.; Papoutsakis, Eleftherios T.

2011-01-01

The pathobiological role of p53 has been widely studied, however its role in normophysiology is relatively unexplored. We previously showed that p53 knock-down increased ploidy in megakaryocytic cultures. This study aims to examine the effect of p53 loss on in vivo megakaryopoiesis, platelet production and function, and to investigate the basis for greater ploidy in p53−/− megakaryocytic cultures. Here, we used flow cytometry to analyze ploidy, DNA synthesis and apoptosis in murine cultured and bone marrow megakaryocytes following thrombopoietin administration and to analyze fibrinogen binding to platelets in vitro. Culture of p53−/− marrow cells for 6 days with thrombopoietin gave rise to 1.7-fold more megakaryocytes, 26.1±3.6% of which reached ploidy classes ≥64N compared to 8.2±0.9% of p53+/+ megakaryocytes. This was due to 30% greater DNA synthesis in p53−/− megakaryocytes and 31% greater apoptosis in p53+/+ megakaryocytes by day 4 of culture. Although the bone marrow and spleen steady-state megakaryocytic content and ploidy were similar in p53+/+ and p53−/− mice, thrombopoietin administration resulted in increased megakaryocytic polyploidization in p53−/− mice. Although their platelet counts were normal, p53−/− mice exhibited significantly longer bleeding times and p53−/− platelets were less sensitive than p53+/+ platelets to agonist-induced fibrinogen binding and P-selectin secretion. In summary, our in vivo and ex-vivo studies indicate that p53 loss leads to increased polyploidization during megakaryopoiesis. Our findings also suggest for the first time a direct link between p53 loss and the development of fully functional platelets resulting in hemostatic deficiencies. PMID:22024107

Reacções cutâneas adversas aos inibidores do receptor do factor de crescimento epidérmico: estudo de 14 doentes Adverse cutaneous reactions to epidermal growth factor receptor inhibitors: a study of 14 patients

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Felicidade Santiago

2011-06-01

Full Text Available FUNDAMENTOS: O cetuximab e o erlotinib, inibidores do receptor do factor de crescimento epidérmico, provocam frequentemente reacções cutâneas adversas peculiares. OBJETIVOS: Caracterizar do ponto de vista clínico-evolutivo as reacções cutâneas adversas e avaliar a sua abordagem terapêutica. METODOLOGIA: Entre março/2005 e setembro/2009 foram seguidos 14 doentes com idade média de 59,6 anos, em tratamento com cetuximab (7 ou erlotinib (7, por neoplasia pulmonar (10 ou colorrectal (4. Retrospectivamente foi avaliado o padrão clínico evolutivo de reacção cutânea, o intervalo entre a introdução do fármaco e o início dos sintomas e a resposta ao tratamento. RESULTADOS: Doze doentes apresentaram erupção papulopustulosa predominantemente na face, decote e dorso, em média 13,5 dias após o início do fármaco. Efectuaram tratamento oral com minociclina ou doxiciclina e tópico com metronidazol, peróxido de benzoílo e/ou corticoide. Ocorreu melhoria das lesões em todos os doentes. Cinco doentes, em média oito semanas após o início da terapia, apresentaram granulomas piogénicos periungueais, em quatro casos associados a paroníquia, melhorados com tratamento tópico (antibióticos, corticoides e antissépticos. Observou-se xerose em alguns doentes e, de forma isolada, outros efeitos adversos, como telangiectasias e angiomas, alterações dos cabelos e cílios e nevos melanocíticos eruptivos. Na maioria dos doentes, a terapêutica com o inibidor do receptor do factor de crescimento epidérmico foi mantida. CONCLUSÃO: Com o crescente uso destas terapêuticas-alvo, torna-se obrigatório reconhecer e tratar os seus efeitos cutâneos adversos, assegurando uma intervenção atempada de forma a permitir a manutenção desta terapêuticaBACKGROUND: Cetuximab and erlotinib, epidermal growth factor receptor inhibitors, often cause peculiar adverse cutaneous reactions. OBJECTIVES: Our aim was to evaluate adverse cutaneous reactions

An adaptive molecular timer in p53-meidated cell fate decision

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Zhang, Xiao-Peng; Wang, Ping; Liu, Feng; Wang, Wei

The tumor suppressor p53 decides cellular outcomes in the DNA damage response. It is intriguing to explore the link between p53 dynamics and cell fates. We developed a theoretical model of p53 signaling network to clarify the mechanism of cell fate decision mediated by its dynamics. We found that the interplay between p53-Mdm2 negative feedback loop and p53-PTEN-Mdm2 positive feedback loop shapes p53 dynamics. Depending on the intensity of DNA damage, p53 shows three modes of dynamics: persistent pulses, two-phase dynamics with pulses followed by sustained high levels and straightforward high levels. Especially, p53 shows two-phase dynamics upon moderated damage and the required number of p53 pulses before apoptosis induction decreases with increasing DNA damage. Our results suggested there exists an adaptive molecular timer that determines whether and when the apoptosis switch should be triggered. We clarified the mechanism behind the switching of p53 dynamical modes by bifurcation analysis. Moreover, we reproduced the experimental results that drug additions alter p53 pulses to sustained p53 activation and leads to senescence. Our work may advance the understanding the significance of p53 dynamics in tumor suppression. This work was supported by National Natural Science Foundation of China (Nos. 11175084, 11204126 and 31361163003).

The p53 gene with emphasis on its paralogues in mosquitoes

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Tien-Huang Chen

2017-12-01

Full Text Available The p53 gene is highly important in human cancers, as it serves as a tumor-suppressor gene. Subsequently, two p53 homologues, i.e., p73 and p63, with high identity of amino acids were identified, leading to construction of the p53 family. The p53 gene is highly important in human cancer because it usually transcribes genes that function by causing apoptosis in mammalian cells. In contrast, p63 and p73 tend to be more important in modulating development than inducing cell death, even though they share similar protein structures. Relatively recently, p53 was also identified in mosquitoes and many other insect species. Uniquely, its structure lacks the sterile alpha motif domain which is a putative protein-protein interaction domain and exclusively exists at the C-terminal region in p73 and p63 in mammals. A phylogenetic analysis revealed that the p53 gene derived from mosquitoes is composed of two paralogues, p53-1 and p53-2. Of these, only p53-2 is responsively upregulated by dengue 2 virus (DENV2 in C6/36 cells which usually survive the infection. This indicates that the p53 gene is closely related to DENV infection in mosquito cells. The specific significance of p53-2's involvement in cell survival from virus-induced stress is described and briefly discussed in this report. Keywords: p53 homologue, Paralogue, Mosquitoes, Phylogeny, Cell survival

Dopaminergic Neuron-Specific Deletion of p53 Gene Attenuates Methamphetamine Neurotoxicity.

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Lu, Tao; Kim, Paul P; Greig, Nigel H; Luo, Yu

2017-08-01

p53 plays an essential role in the regulation of cell death in dopaminergic (DA) neurons and its activation has been implicated in the neurotoxic effects of methamphetamine (MA). However, how p53 mediates MA neurotoxicity remains largely unknown. In this study, we examined the effect of DA-specific p53 gene deletion in DAT-p53KO mice. Whereas in vivo MA binge exposure reduced locomotor activity in wild-type (WT) mice, this was significantly attenuated in DAT-p53KO mice and associated with significant differences in the levels of the p53 target genes BAX and p21 between WT and DAT-p53KO. Notably, DA-specific deletion of p53 provided protection of substantia nigra pars reticulata (SNpr) tyrosine hydroxylase (TH) positive fibers following binge MA, with DAT-p53KO mice having less decline of TH protein levels in striatum versus WT mice. Whereas DAT-p53KO mice demonstrated a consistently higher density of TH fibers in striatum compared to WT mice at 10 days after MA exposure, DA neuron counts within the substantia nigra pars compacta (SNpc) were similar. Finally, supportive of these results, administration of a p53-specific inhibitor (PFT-α) provided a similarly protective effect on MA binge-induced behavioral deficits. Neither DA specific p53 deletion nor p53 pharmacological inhibition affected hyperthermia induced by MA binge. These findings demonstrate a specific contribution of p53 activation in behavioral deficits and DA neuronal terminal loss by MA binge exposure.

HMGB1-mediated DNA bending: Distinct roles in increasing p53 binding to DNA and the transactivation of p53-responsive gene promoters.

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Štros, Michal; Kučírek, Martin; Sani, Soodabeh Abbasi; Polanská, Eva

2018-03-01

HMGB1 is a chromatin-associated protein that has been implicated in many important biological processes such as transcription, recombination, DNA repair, and genome stability. These functions include the enhancement of binding of a number of transcription factors, including the tumor suppressor protein p53, to their specific DNA-binding sites. HMGB1 is composed of two highly conserved HMG boxes, linked to an intrinsically disordered acidic C-terminal tail. Previous reports have suggested that the ability of HMGB1 to bend DNA may explain the in vitro HMGB1-mediated increase in sequence-specific DNA binding by p53. The aim of this study was to reinvestigate the importance of HMGB1-induced DNA bending in relationship to the ability of the protein to promote the specific binding of p53 to short DNA duplexes in vitro, and to transactivate two major p53-regulated human genes: Mdm2 and p21/WAF1. Using a number of HMGB1 mutants, we report that the HMGB1-mediated increase in sequence-specific p53 binding to DNA duplexes in vitro depends very little on HMGB1-mediated DNA bending. The presence of the acidic C-terminal tail of HMGB1 and/or the oxidation of the protein can reduce the HMGB1-mediated p53 binding. Interestingly, the induction of transactivation of p53-responsive gene promoters by HMGB1 requires both the ability of the protein to bend DNA and the acidic C-terminal tail, and is promoter-specific. We propose that the efficient transactivation of p53-responsive gene promoters by HMGB1 depends on complex events, rather than solely on the promotion of p53 binding to its DNA cognate sites. Copyright © 2018 Elsevier B.V. All rights reserved.

Mitofusin-2 is a novel direct target of p53

International Nuclear Information System (INIS)

Wang, Weilin; Cheng, Xiaofei; Lu, Jianju; Wei, Jianfeng; Fu, Guanghou; Zhu, Feng; Jia, Changku; Zhou, Lin; Xie, Haiyang; Zheng, Shusen

2010-01-01

Research highlights: → Mfn2 is a novel target gene of p53. → Mfn2 mRNA and protein levels can be up-regulated in a p53-dependent manner. → Mfn2 promoter activity can be elevated by the p53 protein. → P53 protein binds the Mfn2 promoter directly both in vitro and in vivo. -- Abstract: The tumor suppressor p53 modulates transcription of a number of target genes involved in cell cycle arrest, apoptosis, DNA repair, and other important cellular responses. Mitofusin-2 (Mfn2) is a novel suppressor of cell proliferation that may also exert apoptotic effects via the mitochondrial apoptotic pathway. Through bioinformatics analysis, we identified a p53 binding site in the Mfn2 promoter. Consistent with this, we showed that the p53 protein binds the Mfn2 promoter directly both in vitro and in vivo. Additionally, we found that Mfn2 mRNA and protein levels are up-regulated in a p53-dependent manner. Furthermore, luciferase assays revealed that the activity of the wild-type Mfn2 promoter, but not a mutated version of the promoter, was up-regulated by p53. These results indicate that Mfn2 is a novel p53-inducible target gene, which provides insight into the regulation of Mfn2 and its associated activities in the inhibition of cell proliferation, promotion of apoptosis, and modulation of tumor suppression.

Differential sensitivity of p53+ and p53- cells to caffeine-induced radiosensitization and override of G2 delay

International Nuclear Information System (INIS)

Powell, S.N.; DeFrank, J.S.; Connell, P.; Eogan, M.; Preffer, F.; Dombkowski, D.; Tang, W.; Friend, S.H.

1995-01-01

Purpose: Most drug discovery efforts have focused on finding new DNA damaging agents to kill tumor cells preferentially. An alternative approach is to find ways to increase tumor specific killing by modifying tumor specific responses to that damage. We asked whether cells lacking the G1/S arrest in response to X-rays are more sensitive to X-ray damage when treated with agents that override G2/M arrest. Materials and Methods: Mouse embryonic fibroblasts genetically matched to be (+/+) or (-/-) p53 and rat embryonic fibroblasts (REF) made (+) or (-) for wild-type p53 function by transfection were irradiated with and without caffeine, a known checkpoint inhibitor. Caffeine treatment was maintained for 24 hours from 1 hour prior to irradiation. Cell survival following ionizing radiation was measured by clonogenic assay. For cell-cycle analysis, cells were in exponential asynchronous growth at the time of irradiation. The proportion of cells in G1, S and G2/M phases of the cell cycle were recorded immediately before and following irradiation and subsequently at 3,6,9,12,24 and 48 hours following irradiation. Results: Caffeine was found to cause radiosensitzation at low dose (0.5mM) in (-/-) cells but not in (+/+) cells. The sensitization enhancement ratio (SER) was 1.45 at 0.1 survival and 1.56 at 0.01 survival. At this dose of caffeine, this SER reflected therapeutic gain as there was no detectable effect on (+/+) cells. At 1mM caffeine, sensitization of (-/-) cells was 1.77, but (+/+) cells now also showed sensitization (SER=1.25). In (-/-) cells at 0.1mM caffeine the SER was 1.5 at 0.01 survival. The transfected REF cells (functionally null for p53) also exhibited caffeine-induced radiosensitization at both 0.5 and 2mM caffeine with a SER 1.45 for 2mM at 0.1 survival. No significant sensitization could be demonstrated for REF cells at the same doses of caffeine. The REF cells, with wild-type p53, transfected with pCMVneo alone showed no change in radiosensitivity or

40 Years of Research Put p53 in Translation

Science.gov (United States)

Marcel, Virginie; Nguyen Van Long, Flora; Diaz, Jean-Jacques

2018-01-01

Since its discovery in 1979, p53 has shown multiple facets. Initially the tumor suppressor p53 protein was considered as a stress sensor able to maintain the genome integrity by regulating transcription of genes involved in cell cycle arrest, apoptosis and DNA repair. However, it rapidly came into light that p53 regulates gene expression to control a wider range of biological processes allowing rapid cell adaptation to environmental context. Among them, those related to cancer have been extensively documented. In addition to its role as transcription factor, scattered studies reported that p53 regulates miRNA processing, modulates protein activity by direct interaction or exhibits RNA-binding activity, thus suggesting a role of p53 in regulating several layers of gene expression not restricted to transcription. After 40 years of research, it appears more and more clearly that p53 is strongly implicated in translational regulation as well as in the control of the production and activity of the translational machinery. Translation control of specific mRNAs could provide yet unsuspected capabilities to this well-known guardian of the genome.

ZNF307, a novel zinc finger gene suppresses p53 and p21 pathway

International Nuclear Information System (INIS)

Li Jing; Wang Yuequn; Fan Xiongwei; Mo Xiaoyang; Wang Zequn; Li Yongqing; Yin Zhaochu; Deng Yun; Luo Na; Zhu Chuanbing; Liu Mingyao; Ma Qian; Ocorr, Karen; Yuan Wuzhou; Wu Xiushan

2007-01-01

We have cloned a novel KRAB-related zinc finger gene, ZNF307, encoding a protein of 545 aa. ZNF307 is conserved across species in evolution and is differentially expressed in human adult and fetal tissues. The fusion protein of EGFP-ZNF307 localizes in the nucleus. Transcriptional activity assays show ZNF307 suppresses transcriptional activity of L8G5-luciferase. Overexpressing ZNF307 in different cell lines also inhibits the transcriptional activities of p53 and p21. Moreover, ZNF307 works by reducing the p53 protein level and p53 protein reduction is achieved by increasing transcription of MDM2 and EP300. ZNF307 might suppress p53-p21 pathway through activating MDM2 and EP300 expression and inducing p53 degradation

Expressão de p53, p16 E COX-2 em carcinoma escamoso de esôfago e associação histopatológica p53, p16 E COX-2 expression in esophageal squamous cell carcinoma and histopathological association

OpenAIRE

Izabella Paz Danezi Felin; Ivana Grivicich; Carlos Roberto Felin; Andrea Regner; Adriana Brondani da Rocha

2008-01-01

RACIONAL: O câncer de esôfago representa cerca de 2% dos tumores malignos e a terceira causa mais comum de câncer do trato gastrointestinal. A associação do prognóstico do câncer de esôfago com alguns marcadores imunoistoquímicos, como as proteínas p53, p16 e a ciclooxigenase 2 (COX-2) tem sido relatada. A detecção de marcadores moleculares através de imunoistoquímica pode ser utilizada para avaliação prognóstica. OBJETIVOS: Investigar a associação entre a expressão das proteínas p53, p16 e a...

Papel neuroprotector da hipotermia terapêutica pós paragem cardio-respiratória

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Ana Abreu; Ana Duque; Carolina Paulino; João Brito; Joana Silvestre; João Gonçalves-Pereira; Vítor Mendes; Camila Tapadinhas; Pedro Póvoa

2011-01-01

OBJECTIVOS: A hipotermia terapêutica demonstrou ter efeitos neuro e cardioprotectores, com melhoria da sobrevida e redução das sequelas neurológicas em doentes vítimas de paragem cardio-respiratória. O objectivo deste estudo foi avaliar a evolução dos doentes submetidos a hipotermia terapêutica após paragem cardio-respiratória. MÉTODOS: Estudo prospectivo observacional dos doentes submetidos a hipotermia terapêutica após paragem cardio-respiratória numa unidade de cuidados intensivos polivale...

Effect of recombinant adenovirus encoding human p53 tumor suppressor gene (rAd-p53) on the growth and radiotherapeutic sensitivity of human lymphoma cell lines

International Nuclear Information System (INIS)

Yu Zeyang; Fan Wo; Li Dongqing; Zhu Ran; Wang Yongqing; Wu Jinchang

2008-01-01

Objective: To explore the inhibitory effect and radiation sensitization of recombinant adenovirus encoding human p53 tumor suppressor gene (rAd-p53) on human lymphoma cell lines. Methods: Human lymphoma cell lines Raji and Daudi were treated with rAd-p53, radiation therapy and combined treatment, respectively. The cell growth inhibition was assessed by MTT. The p53 protein expression was detected by Western blotting, and p53 mRNA was detected by BT-PCB. Results: The MTT results showed that the inhibitory effect and radiosensitivity enhancement of rAd-p53 on human lymphoma cell lines were not obvious [Raji: (27.5±4.1)%; Daudi: (28.1±1.6)%]. The results of Western blotting and BT-PCB showed that extrinsic p53 protein and p53 mRNA were expressed to some degree, but not at high-level. In addition, the results didn't demonstrate obvious radiosensitivity enhancement. Conclusions: The role of inhibition and radiosensitivity enhancement of rAd-p53 was not significant on human lymphoma cell lines. (authors)

Adenocarcinoma do pulmão em doente com esclerodermia: Um caso clínico

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João Bento

2009-01-01

Full Text Available Resumo: A esclerodermia é uma doença do tecido conjuntivo de etiologia desconhecida, que tem sido associada a um risco acrescido de malignidade. O cancro do pulmão é a neoplasia mais frequente, nestes doentes.Apresenta-se o caso clínico de uma mulher de 42 anos, não fumadora, com esclerodermia, que desenvolveu agravamento progressivo do seu estado geral e derrame pleural com características de exsudado, sem evidência de infecção ou malignidade. A TAC torácica mostrou zonas de fibrose, a broncofibroscopia, os lavados brônquico e broncoalveolar foram normais. Foi excluída neoplasia extrapulmonar. Na pleuroscopia, observaram-se formações nodulares, cujas biópsias revelaram tratar-se de adenocarcinoma pulmonar. Iniciou quimioterapia, desenvolvendo ao 48.° dia neutropenia febril e sépsis, vindo a morrer 12 dias depois.Salientamos este caso pela relação, apesar de rara, entre a esclerodermia e o cancro do pulmão e pela importância de uma vigilância pulmonar cuidadosa, em indivíduos com esta doença reumatológica, pelo risco acrescido de neoplasia. Abstract: Systemic sclerosis (scleroderma is a connective tissue disorder of unknown aetiology characterised by immune abnormalities, which has been related to an increased risk of malignancy. Lung cancer is the most prevalent among these patients.We present a clinical case of a 42 years old non smoker female with systemic sclerosis. She presented progressive general health status worsening and an exudative pleural effusion, with no evidence of infection or malignancy. Chest high resolution computed tomography revealed pulmonary fibrosis. Bronchoscopy, bronchial and bronchoalveolar lavage were normal. Extrapulmonary malignancies were excluded. Pleural nodularities were found on pleuroscopy and the biopsy was compatible with lung adenocarcinoma. Chemotherapy was then started, which complicated with febrile neutropenia, sepsis and patient death 12 days after.The purpose of this case

The Prognostic Impact of p53 Expression on Sporadic Colorectal Cancer Is Dependent on p21 Status

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Kruschewski, Martin; Mueller, Kathrin; Lipka, Sybille; Budczies, Jan; Noske, Aurelia; Buhr, Heinz Johannes; Elezkurtaj, Sefer

2011-01-01

The prognostic value of p53 and p21 expression in colorectal cancer is still under debate. We hypothesize that the prognostic impact of p53 expression is dependent on p21 status. The expression of p53 and p21 was immunohistochemically investigated in a prospective cohort of 116 patients with UICC stage II and III sporadic colorectal cancer. The results were correlated with overall and recurrence-free survival. The mean observation period was 51.8 ± 2.5 months. Expression of p53 was observed in 72 tumors (63%). Overall survival was significantly better in patients with p53-positive carcinomas than in those without p53 expression (p = 0.048). No differences were found in recurrence-free survival (p = 0.161). The p53+/p21− combination was seen in 68% (n = 49), the p53+/p21+ combination in 32% (n = 23). Patients with p53+/p21− carcinomas had significantly better overall and recurrence-free survival than those with p53+/p21+ (p < 0.0001 resp. p = 0.003). Our data suggest that the prognostic impact of p53 expression on sporadic colorectal cancer is dependent on p21 status

Molecular mechanism of X-ray-induced p53-dependent apoptosis

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Nakano, Hisako [Tokyo Metropolitan Inst. of Medical Center (Japan)

1999-03-01

Radiation-induced cell death has been classified into the interphase- and mitotic-ones, both of which apoptosis involving. This review described the molecular mechanism of the apoptosis, focusing on its p53-dependent process. It is known that there are genes regulating cell death either negatively or positively and the latter is involved in apoptosis. As an important factor in the apoptosis, p53 has become remarkable since it was shown that X-ray-induced apoptosis required RNA and protein syntheses in thymocytes and those cells of p53 gene-depleted mouse were shown to be resistant to gamma-ray-induced apoptosis. Radiation sensitivity of MOLT-4 cells derived from human T cell leukemia, exhibiting the typical X-ray-induced p53-dependent apoptosis, depends on the levels of p53 mRNA and protein. p53 is a gene suppressing tumor and also a transcription factor. Consequently, mutation of p53 conceivably leads to the failure of cell cycle regulation, which allows damaged cells to divide without both repair and exclusion due to loss of the apoptotic mechanism, and finally results in carcinogenesis. The radiation effect occurs in the order of the cell damage, inhibition of p53-Mdm2 binding, accumulation of p53, activation of mdm2 transcription, Mdm2 accumulation, p53-protein degradation and recovery to the steady state level. Here, the cystein protease (caspases) plays an important role as a disposing mechanism for cells scheduled to die. However, many are unknown to be solved in future. (K.H.) 119 refs.

Gene expression patterns associated with p53 status in breast cancer

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Troester, Melissa A; Herschkowitz, Jason I; Oh, Daniel S; He, Xiaping; Hoadley, Katherine A; Barbier, Claire S; Perou, Charles M

2006-01-01

Breast cancer subtypes identified in genomic studies have different underlying genetic defects. Mutations in the tumor suppressor p53 occur more frequently in estrogen receptor (ER) negative, basal-like and HER2-amplified tumors than in luminal, ER positive tumors. Thus, because p53 mutation status is tightly linked to other characteristics of prognostic importance, it is difficult to identify p53's independent prognostic effects. The relation between p53 status and subtype can be better studied by combining data from primary tumors with data from isogenic cell line pairs (with and without p53 function). The p53-dependent gene expression signatures of four cell lines (MCF-7, ZR-75-1, and two immortalized human mammary epithelial cell lines) were identified by comparing p53-RNAi transduced cell lines to their parent cell lines. Cell lines were treated with vehicle only or doxorubicin to identify p53 responses in both non-induced and induced states. The cell line signatures were compared with p53-mutation associated genes in breast tumors. Each cell line displayed distinct patterns of p53-dependent gene expression, but cell type specific (basal vs. luminal) commonalities were evident. Further, a common gene expression signature associated with p53 loss across all four cell lines was identified. This signature showed overlap with the signature of p53 loss/mutation status in primary breast tumors. Moreover, the common cell-line tumor signature excluded genes that were breast cancer subtype-associated, but not downstream of p53. To validate the biological relevance of the common signature, we demonstrated that this gene set predicted relapse-free, disease-specific, and overall survival in independent test data. In the presence of breast cancer heterogeneity, experimental and biologically-based methods for assessing gene expression in relation to p53 status provide prognostic and biologically-relevant gene lists. Our biologically-based refinements excluded genes

Effect of p53 genotype on gene expression profiles in murine liver

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Morris, Suzanne M.; Akerman, Gregory S.; Desai, Varsha G.; Tsai, Chen-an; Tolleson, William H.; Melchior, William B.; Lin, Chien-Ju; Fuscoe, James C.; Casciano, Daniel A.; Chen, James J.

2008-01-01

The tumor suppressor protein p53 is a key regulatory element in the cell and is regarded as the 'guardian of the genome'. Much of the present knowledge of p53 function has come from studies of transgenic mice in which the p53 gene has undergone a targeted deletion. In order to provide additional insight into the impact on the cellular regulatory networks associated with the loss of this gene, microarray technology was utilized to assess gene expression in tissues from both the p53 -/- and p53 +/- mice. Six male mice from each genotype (p53 +/+ , p53 +/- , and p53 -/- ) were humanely killed and the tissues processed for microarray analysis. The initial studies have been performed in the liver for which the Dunnett test revealed 1406 genes to be differentially expressed between p53 +/+ and p53 +/- or between p53 +/+ and p53 -/- at the level of p ≤ 0.05. Both genes with increased expression and decreased expression were identified in p53 +/- and in p53 -/- mice. Most notable in the gene list derived from the p53 +/- mice was the significant reduction in p53 mRNA. In the p53 -/- mice, not only was there reduced expression of the p53 genes on the array, but genes associated with DNA repair, apoptosis, and cell proliferation were differentially expressed, as expected. However, altered expression was noted for many genes in the Cdc42-GTPase pathways that influence cell proliferation. This may indicate that alternate pathways are brought into play in the unperturbed liver when loss or reduction in p53 levels occurs

p18(Hamlet) mediates different p53-dependent responses to DNA-damage inducing agents.

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Lafarga, Vanesa; Cuadrado, Ana; Nebreda, Angel R

2007-10-01

Cells organize appropriate responses to environmental cues by activating specific signaling networks. Two proteins that play key roles in coordinating stress responses are the kinase p38alpha (MAPK14) and the transcription factor p53 (TP53). Depending on the nature and the extent of the stress-induced damage, cells may respond by arresting the cell cycle or by undergoing cell death, and these responses are usually associated with the phosphorylation of particular substrates by p38alpha as well as the activation of specific target genes by p53. We recently characterized a new p38alpha substrate, named p18(Hamlet) (ZNHIT1), which mediates p53-dependent responses to different genotoxic stresses. Thus, cisplatin or UV light induce stabilization of the p18(Hamlet) protein, which then enhances the ability of p53 to bind to and activate the promoters of pro-apoptotic genes such as NOXA and PUMA leading to apoptosis induction. In a similar way, we report here that p18(Hamlet) can also mediate the cell cycle arrest induced in response to gamma-irradiation, by participating in the p53-dependent upregulation of the cell cycle inhibitor p21(Cip1) (CDKN1A).

Stimulation of autophagy by the p53 target gene Sestrin2.

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Maiuri, Maria Chiara; Malik, Shoaib Ahmad; Morselli, Eugenia; Kepp, Oliver; Criollo, Alfredo; Mouchel, Pierre-Luc; Carnuccio, Rosa; Kroemer, Guido

2009-05-15

The oncosuppressor protein p53 regulates autophagy in a dual fashion. The pool of cytoplasmic p53 protein represses autophagy in a transcription-independent fashion, while the pool of nuclear p53 stimulates autophagy through the transactivation of specific genes. Here we report the discovery that Sestrin2, a novel p53 target gene, is involved in the induction of autophagy. Depletion of Sestrin2 by RNA interference reduced the level of autophagy in a panel of p53-sufficient human cancer cell lines responding to distinct autophagy inducers. In quantitative terms, Sestrin2 depletion was as efficient in preventing autophagy induction as was the depletion of Dram, another p53 target gene. Knockout of either Sestrin2 or Dram reduced autophagy elicited by nutrient depletion, rapamycin, lithium or thapsigargin. Moreover, autophagy induction by nutrient depletion or pharmacological stimuli led to an increase in Sestrin2 expression levels in p53-proficient cells. In strict contrast, the depletion of Sestrin2 or Dram failed to affect autophagy in p53-deficient cells and did not modulate the inhibition of baseline autophagy by a cytoplasmic p53 mutant that was reintroduced into p53-deficient cells. We conclude that Sestrin2 acts as a positive regulator of autophagy in p53-proficient cells.

The antagonism between MCT-1 and p53 affects the tumorigenic outcomes

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Lin Tai-Du

2010-12-01

Full Text Available Abstract Background MCT-1 oncoprotein accelerates p53 protein degradation via a proteosome pathway. Synergistic promotion of the xenograft tumorigenicity has been demonstrated in circumstance of p53 loss alongside MCT-1 overexpression. However, the molecular regulation between MCT-1 and p53 in tumor development remains ambiguous. We speculate that MCT-1 may counteract p53 through the diverse mechanisms that determine the tumorigenic outcomes. Results MCT-1 has now identified as a novel target gene of p53 transcriptional regulation. MCT-1 promoter region contains the response elements reactive with wild-type p53 but not mutant p53. Functional p53 suppresses MCT-1 promoter activity and MCT-1 mRNA stability. In a negative feedback regulation, constitutively expressed MCT-1 decreases p53 promoter function and p53 mRNA stability. The apoptotic events are also significantly prevented by oncogenic MCT-1 in a p53-dependent or a p53-independent fashion, according to the genotoxic mechanism. Moreover, oncogenic MCT-1 promotes the tumorigenicity in mice xenografts of p53-null and p53-positive lung cancer cells. In support of the tumor growth are irrepressible by p53 reactivation in vivo, the inhibitors of p53 (MDM2, Pirh2, and Cop1 are constantly stimulated by MCT-1 oncoprotein. Conclusions The oppositions between MCT-1 and p53 are firstly confirmed at multistage processes that include transcription control, mRNA metabolism, and protein expression. MCT-1 oncogenicity can overcome p53 function that persistently advances the tumor development.

Tumor suppressor p53 biology, its role in radioresponse and the analysis of p53 mutation/expression among Filipino breast cancers

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Deocaris, Custer C.

2004-01-01

Ionizing radiation remains one of the most effective tools for the treatment of breast cancer. It combines properties of a potent DNA-damaging agent and high degree of spatial specificity to the target tissue. Nonetheless, there remain considerable differences in the outcome for treatment of tumors of differing histological type treated by radiotherapy. The identification of predictive indicators of radiosensitivity is crucial for selecting patients suited for preoperative radiotherapy as well as those unwarranted for postoperative treatments. To improve prognostication, numerous genes involved in the breast carcinogenesis have been studied and thus far over the last decade several multi-center researches converge on the role of tumor suppressor p53 in tumor biology. The p53 gene is located on the short arm of chromosome 17 and encodes a 53-kd nuclear protein, p-53, also referred to as 'the guardian of the genome', it orchestrates multiple cellular processes such as cell growth control, DNA repair and programmed cell death. During radiotherapy, genotoxic damage induces p53 overexpression in order to control the rate of proliferating damaged cells, repair damage or induce the apoptotic pathway. Its molecular inactivation in a tumor cell, typically by a point mutation, leads to chemo/radio resistance due to the inability of the molecule to trigger p53-dependent programmed cell death

Phenotype specific analyses reveal distinct regulatory mechanism for chronically activated p53.

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Kristina Kirschner

2015-03-01

Full Text Available The downstream functions of the DNA binding tumor suppressor p53 vary depending on the cellular context, and persistent p53 activation has recently been implicated in tumor suppression and senescence. However, genome-wide information about p53-target gene regulation has been derived mostly from acute genotoxic conditions. Using ChIP-seq and expression data, we have found distinct p53 binding profiles between acutely activated (through DNA damage and chronically activated (in senescent or pro-apoptotic conditions p53. Compared to the classical 'acute' p53 binding profile, 'chronic' p53 peaks were closely associated with CpG-islands. Furthermore, the chronic CpG-island binding of p53 conferred distinct expression patterns between senescent and pro-apoptotic conditions. Using the p53 targets seen in the chronic conditions together with external high-throughput datasets, we have built p53 networks that revealed extensive self-regulatory 'p53 hubs' where p53 and many p53 targets can physically interact with each other. Integrating these results with public clinical datasets identified the cancer-associated lipogenic enzyme, SCD, which we found to be directly repressed by p53 through the CpG-island promoter, providing a mechanistic link between p53 and the 'lipogenic phenotype', a hallmark of cancer. Our data reveal distinct phenotype associations of chronic p53 targets that underlie specific gene regulatory mechanisms.

Acetylation Is Crucial for p53-Mediated Ferroptosis and Tumor Suppression

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Shang-Jui Wang

2016-10-01

Full Text Available Although previous studies indicate that loss of p53-mediated cell cycle arrest, apoptosis, and senescence does not completely abrogate its tumor suppression function, it is unclear how the remaining activities of p53 are regulated. Here, we have identified an acetylation site at lysine K98 in mouse p53 (or K101 for human p53. Whereas the loss of K98 acetylation (p53K98R alone has very modest effects on p53-mediated transactivation, simultaneous mutations at all four acetylation sites (p534KR: K98R+ 3KR[K117R+K161R+K162R] completely abolish its ability to regulate metabolic targets, such as TIGAR and SLC7A11. Notably, in contrast to p533KR, p534KR is severely defective in suppressing tumor growth in mouse xenograft models. Moreover, p534KR is still capable of inducing the p53-Mdm2 feedback loop, but p53-dependent ferroptotic responses are markedly abrogated. Together, these data indicate the critical role of p53 acetylation in ferroptotic responses and its remaining tumor suppression activity.

p53-Induced Apoptosis Occurs in the Absence of p14ARF in Malignant Pleural Mesothelioma

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Sally Hopkins-Donaldson

2006-07-01

Full Text Available Malignant pleural mesotheliomas (MPMs are usually wild type for the p53 gene but contain homozygous deletions in the INK4A locus that encodes p14ARF, an inhibitor of p53-MDM2 interaction. Previous findings suggest that lack of p14ARF expression and the presence of SV40 large T antigen (L-Tag result in p53 inactivation in MPM. We did not detect SV40 L-Tag mRNA in either MPM cell lines or primary cultures, treatment of p14ARF-deficient cells with cisplatin (CDDP increased both total and phosphorylated p53 and enhanced p53 DNA-binding activity. On incubation with CDDP, levels of positively regulated p53 transcriptional targets p21WAF, PIG3, MDM2, Bax, PUMA increased in p14ARF-deficient cells, whereas negatively regulated survivin decreased. Significantly, p53-induced apoptosis was activated by CDDP in p14ARF-deficient cells, treatment with p53-specific siRNA rendered them more CDDP-resistant. p53 was also activated by: 1 inhibition of MDM2 (using nutlin-3; 2 transient overexpression of p14ARF; and 3 targeting of survivin using antisense oligonucleotides. However, it is noteworthy that only survivin downregulation sensitized cells to CDDP-induced apoptosis. These results suggest that p53 is functional in the absence of p14ARF in MPM and that targeting of the downstream apoptosis inhibitor survivin can sensitize to CDDP-induced apoptosis.

Gene expression and apoptosis induction in p53-heterozygous irradiated mice

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Di Masi, Alessandra; Antoccia, Antonio; Dimauro, Ivan; Argentino-Storino, Alberta; Mosiello, Alberto; Mango, Ruggiero; Novelli, Giuseppe; Tanzarella, Caterina

2006-01-01

The role of the p53-genetic background in the expression of genes involved in either cell cycle checkpoint activation or apoptosis was evaluated in p53+/+ and p53+/- mouse strains at both basal levels and after DNA-induced damage. The spleen, colon, kidneys, lungs and liver of both strains were harvested from untreated animals and from mice exposed to 7.5 Gy of X-rays and sacrificed after 5 h. No significant differences were observed in the basal levels of p53 protein, CDKN1A and bax mRNA and spontaneous apoptosis, neither among the different organs within the same strain, nor between the same organ in the p53+/+ and p53+/- strains. After X-ray exposure, p53-dependent regulation was strikingly tissue-specific. In wild-type irradiated mice, p53 protein level increased after radiation treatment in all the organs analysed, whereas both CDKN1A and bax genes transcription increased in the spleen, colon and lungs, as assessed by means of quantitative RT-PCR. In p53+/- irradiated mice, on the contrary, a significant p53 induction was detected only in the spleen, while CDKN1A and bax genes levels increased in the spleen, colon and lungs, revealing the existence of different mechanisms of gene regulation in different organs. Apoptosis induction was observed in the spleen and colon of both strains, even if to lower extent in p53+/- mice compared to p53+/+ animals. In conclusion, in the spleen and colon, target gene transcription and apoptosis may be related to p53 genotype after DNA damage-induction. Moreover, our findings highlight the selectivity of p53 in transactivation following DNA damage in vivo, resulting in tissue-specific responses

Gene expression and apoptosis induction in p53-heterozygous irradiated mice

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Di Masi, Alessandra [Department of Biology, University of Rome ' Roma Tre' , Viale G. Marconi, 446, 00146 Rome (Italy); Antoccia, Antonio [Department of Biology, University of Rome ' Roma Tre' , Viale G. Marconi, 446, 00146 Rome (Italy); Dimauro, Ivan [Department of Biology, University of Rome ' Roma Tre' , Viale G. Marconi, 446, 00146 Rome (Italy); Argentino-Storino, Alberta [Research Toxicology Centre S.p.A., Via Tito Speri, 18, 00040 Pomezia (RM) (Italy); Mosiello, Alberto [Research Toxicology Centre S.p.A., Via Tito Speri, 18, 00040 Pomezia (RM) (Italy); Mango, Ruggiero [Centre of Excellence for Genomic Risk Assessment in Multifactorial and Complex Diseases, School of Medicine, University of Rome ' Tor Vergata' , Rome (Italy); Novelli, Giuseppe [Centre of Excellence for Genomic Risk Assessment in Multifactorial and Complex Diseases, School of Medicine, University of Rome ' Tor Vergata' , Rome (Italy); Tanzarella, Caterina [Department of Biology, University of Rome ' Roma Tre' , Viale G. Marconi, 446, 00146 Rome (Italy)]. E-mail: tanzarel@uniroma3.it

2006-02-22

The role of the p53-genetic background in the expression of genes involved in either cell cycle checkpoint activation or apoptosis was evaluated in p53+/+ and p53+/- mouse strains at both basal levels and after DNA-induced damage. The spleen, colon, kidneys, lungs and liver of both strains were harvested from untreated animals and from mice exposed to 7.5 Gy of X-rays and sacrificed after 5 h. No significant differences were observed in the basal levels of p53 protein, CDKN1A and bax mRNA and spontaneous apoptosis, neither among the different organs within the same strain, nor between the same organ in the p53+/+ and p53+/- strains. After X-ray exposure, p53-dependent regulation was strikingly tissue-specific. In wild-type irradiated mice, p53 protein level increased after radiation treatment in all the organs analysed, whereas both CDKN1A and bax genes transcription increased in the spleen, colon and lungs, as assessed by means of quantitative RT-PCR. In p53+/- irradiated mice, on the contrary, a significant p53 induction was detected only in the spleen, while CDKN1A and bax genes levels increased in the spleen, colon and lungs, revealing the existence of different mechanisms of gene regulation in different organs. Apoptosis induction was observed in the spleen and colon of both strains, even if to lower extent in p53+/- mice compared to p53+/+ animals. In conclusion, in the spleen and colon, target gene transcription and apoptosis may be related to p53 genotype after DNA damage-induction. Moreover, our findings highlight the selectivity of p53 in transactivation following DNA damage in vivo, resulting in tissue-specific responses.

Lactato sérico como marcador prognóstico em crianças gravemente doentes Blood lactate concentration as prognostic marker in critically ill children

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Adriana Koliski

2005-08-01

Full Text Available OBJETIVO: Verificar a utilidade do lactato como marcador de hipoperfusão tecidual e como índice prognóstico em crianças criticamente doentes. MÉTODOS: Estudo prospectivo, longitudinal, tipo observacional de 75 pacientes admitidos na UTI pediátrica do Hospital de Clínicas (UFPR entre novembro de 1998 e maio de 1999. De acordo com o nível de lactato na admissão, os pacientes foram divididos em grupo A (lactato > 18 mg/dl e grupo B (lactato 18 mg/dl evidenciou sinais clínicos de hipoperfusão na admissão. A normalização ou diminuição dos níveis de lactato a partir de 24 horas de internação esteve significativamente relacionada com a maior probabilidade de sobrevida.OBJECTIVE: To assess the use of lactate as a marker of tissue hypoperfusion and as a prognostic index in critically ill patients. METHODS: Prospective, longitudinal, observational study of 75 patients admitted to the pediatric ICU of Hospital de Clínicas of Universidade Federal do Paraná, between November 1998 and May 1999. According to the lactate level on admission, patients were divided into group A (lactate > 18 mg/dl and group B (lactate 18 mg/dl showed clinical signs of hypoperfusion on admission. The normalization or reduction of lactate levels at and after 24 hours of admission was significantly related with higher chances of survival.

Family matters: sibling rivalry and bonding between p53 and p63 in cancer.

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Romano, Rose-Anne; Sinha, Satrajit

2014-04-01

The p53 family (p53, p63 and p73) is intimately linked with an overwhelming number of cellular processes during normal physiological as well as pathological conditions including cancer. The fact that these proteins are expressed in myriad isoforms, each with unique biochemical properties and distinct effects on tumorigenesis, complicates their study. A case in point is Squamous Cell Carcinoma (SCC) where p53 is often mutated and the ΔNp63 isoform is overexpressed. Given that p53 and p63 can hetero-dimerize, bind to quite similar DNA elements and share common co-factors, any alterations in their individual expression levels, activity and/or mutation can severely disrupt the family equilibrium. The burgeoning genomics data sets and new additions to the experimental toolbox are offering crucial insights into the complex role of the p53 family in SCC, but more mechanistic studies are needed. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

p53 tumor suppressor gene: significance in neoplasia - a review

International Nuclear Information System (INIS)

Alam, J.M.

2000-01-01

p53 is a tumor suppressor gene located on chromosome 17p13.1. Its function includes cell cycle control and apoptosis. Loss of p53 function, either due to decreased level or genetic transformation, is associated with loss of cell cycle control, decrease, apoptosis and genomic modification, such mutation of p53 gene is now assessed and the indicator of neoplasia of cancer of several organs and cell types, p53 has demonstrated to have critical role in defining various progressive stages of neoplasia, therapeutic strategies and clinical application. The present review briefly describes function of p53 in addition to its diagnostic and prognostic significance in detecting several types of neoplasia. (author)

As moedas doentes, os números públicos e a antropologia do dinheiro

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Federico Neiburg

2007-04-01

Full Text Available Situado na fronteira entre a antropologia da ciência (econômica e a antropologia das culturas monetárias, este artigo propõe uma compreensão dos sentidos sociais e culturais do dinheiro centrada na análise das articulações entre as idéias e as práticas monetárias eruditas e as ordinárias. O texto critica a matriz analítica normativa que predomina em boa parte da literatura sociológica, tributária da própria ciência econômica, e que está preocupada em diagnosticar a "natureza" dos "problemas monetários", distinguindo moedas "normais" de "doentes". Critica também a matriz que predomina em boa parte da literatura antropológica que observa a moeda através da lente da grande divisão entre as moedas "modernas" e as "outras". Ao ter como principal referência empírica as inflações brasileira e argentina da segunda metade do século XX, sugere uma agenda de pesquisas que considera: 1. a presença dos modelos e dos dispositivos monetários criados pelos especialistas nos sentidos e nas práticas ordinárias associadas com o dinheiro; 2. a presença das idéias e das práticas monetárias ordinárias nas formas através das quais os especialistas percebem e agem sobre a moeda; 3. o fato de que os universos de produção de idéias e de dispositivos monetários eruditos, isto é, aqueles que estão referidos às teorias e às políticas monetárias, são suscetíveis de serem analisados com os mesmos instrumentos utilizados para estudar qualquer outro universo nativo; e 4. que esse universo de idéias e de práticas, como não poderia ser de outro modo, está situado no tempo e exige uma análise histórica.Situated on the border between the anthropology of science (economics and the anthropology of monetary cultures, this article investigates the social and cultural meanings of money through an analysis of the inter-connections between academic and everyday monetary ideas and practices. The text critiques the normative analytic

Potential diagnostic value of serum p53 antibody for detecting colorectal cancer: A meta-analysis.

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Meng, Rongqin; Wang, Yang; He, Liang; He, Yuanqing; Du, Zedong

2018-04-01

Numerous studies have assessed the diagnostic value of serum p53 (s-p53) antibody in patients with colorectal cancer (CRC); however, results remain controversial. The present study aimed to comprehensively and quantitatively summarize the potential diagnostic value of s-p53 antibody in CRC. The present study utilized databases, including PubMed and EmBase, systematically regarding s-p53 antibody diagnosis in CRC, accessed on and prior to 31 July 2016. The quality of all the included studies was assessed using quality assessment of studies of diagnostic accuracy (QUADAS). The result of pooled sensitivity, pooled specificity, positive likelihood ratio (PLR) and negative likelihood ratio (NLR) were analyzed and compared with overall accuracy measures using diagnostic odds ratios (DORs) and area under the curve (AUC) analysis. Publication bias and heterogeneity were also assessed. A total of 11 trials that enrolled a combined 3,392 participants were included in the meta-analysis. Approximately 72.73% (8/11) of the included studies were of high quality (QUADAS score >7), and all were retrospective case-control studies. The pooled sensitivity was 0.19 [95% confidence interval (CI), 0.18-0.21] and pooled specificity was 0.93 (95% CI, 0.92-0.94). Results also demonstrated a PLR of 4.56 (95% CI, 3.27-6.34), NLR of 0.78 (95% CI, 0.71-0.85) and DOR of 6.70 (95% CI, 4.59-9.76). The symmetrical summary receiver operating characteristic curve was 0.73. Furthermore, no evidence of publication bias or heterogeneity was observed in the meta-analysis. Meta-analysis data indicated that s-p53 antibody possesses potential diagnostic value for CRC. However, discrimination power was somewhat limited due to the low sensitivity.

1800MHz Microwave Induces p53 and p53-Mediated Caspase-3 Activation Leading to Cell Apoptosis In Vitro.

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Fuqiang Xing

Full Text Available Recent studies have reported that exposure of mammalian cells to microwave radiation may have adverse effects such as induction of cell apoptosis. However, the molecular mechanisms underlying microwave induced mammalian cell apoptosis are not fully understood. Here, we report a novel mechanism: exposure to 1800MHz microwave radiation induces p53-dependent cell apoptosis through cytochrome c-mediated caspase-3 activation pathway. We first measured intensity of microwave radiation from several electronic devices with an irradiation detector. Mouse NIH/3T3 and human U-87 MG cells were then used as receivers of 1800MHz electromagnetic radiation (EMR at a power density of 1209 mW/m2. Following EMR exposure, cells were analyzed for viability, intracellular reactive oxygen species (ROS generation, DNA damage, p53 expression, and caspase-3 activity. Our analysis revealed that EMR exposure significantly decreased viability of NIH/3T3 and U-87 MG cells, and increased caspase-3 activity. ROS burst was observed at 6 h and 48 h in NIH/3T3 cells, while at 3 h in U-87 MG cells. Hoechst 33258 staining and in situ TUNEL assay detected that EMR exposure increased DNA damage, which was significantly restrained in the presence of N-acetyl-L-cysteine (NAC, an antioxidant. Moreover, EMR exposure increased the levels of p53 protein and p53 target gene expression, promoted cytochrome c release from mitochondrion, and increased caspase-3 activity. These events were inhibited by pretreatment with NAC, pifithrin-α (a p53 inhibitor and caspase inhibitor. Collectively, our findings demonstrate, for the first time, that 1800MHz EMR induces apoptosis-related events such as ROS burst and more oxidative DNA damage, which in turn promote p53-dependent caspase-3 activation through release of cytochrome c from mitochondrion. These findings thus provide new insights into physiological mechanisms underlying microwave-induced cell apoptosis.

POSTRANSLATIONAL MODIFICATIONS OF P53: UPSTREAM SIGNALING PATHWAYS.

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ANDERSON,C.W.APPELLA,E.

2003-10-23

The p53 tumor suppressor is a tetrameric transcription factor that is posttranslational modified at >20 different sites by phosphorylation, acetylation, or sumoylation in response to various cellular stress conditions. Specific posttranslational modifications, or groups of modifications, that result from the activation of different stress-induced signaling pathways are thought to modulate p53 activity to regulate cell fate by inducing cell cycle arrest, apoptosis, or cellular senescence. Here we review recent progress in characterizing the upstream signaling pathways whose activation in response to various genotoxic and non-genotoxic stresses result in p53 posttranslational modifications.

Effect of hydroxyurea on the promoter occupancy profiles of tumor suppressor p53 and p73

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Lu Xin

2009-06-01

Full Text Available Abstract Background The p53 tumor suppressor and its related protein, p73, share a homologous DNA binding domain, and mouse genetics studies have suggested that they have overlapping as well as distinct biological functions. Both p53 and p73 are activated by genotoxic stress to regulate an array of cellular responses. Previous studies have suggested that p53 and p73 independently activate the cellular apoptotic program in response to cytotoxic drugs. The goal of this study was to compare the promoter-binding activity of p53 and p73 at steady state and after genotoxic stress induced by hydroxyurea. Results We employed chromatin immunoprecipitation, the NimbleGen promoter arrays and a model-based algorithm for promoter arrays to identify promoter sequences enriched in anti-p53 or anti-p73 immunoprecipitates, either before or after treatment with hydroxyurea, which increased the expression of both p53 and p73 in the human colon cancer cell line HCT116-3(6. We calculated a model-based algorithm for promoter array score for each promoter and found a significant correlation between the promoter occupancy profiles of p53 and p73. We also found that after hydroxyurea treatment, the p53-bound promoters were still bound by p73, but p73 became associated with additional promoters that that did not bind p53. In particular, we showed that hydroxyurea induces the binding of p73 but not p53 to the promoter of MLH3, which encodes a mismatch repair protein, and causes an up-regulation of the MLH3 mRNA. Conclusion These results suggest that hydroxyurea exerts differential effects on the promoter-binding functions of p53 and p73 and illustrate the power of model-based algorithm for promoter array in the analyses of promoter occupancy profiles of highly homologous transcription factors.

The role of p53 molecule in radiation and hyperthermic therapies

International Nuclear Information System (INIS)

Yasumoto, Jun-ichi; Takahashi, Akihisa; Ohnishi, Ken; Ohnishi, Takeo

2003-01-01

In recent years, cancer-related genes have been analyzed at the molecular level as predictive indicators for cancer therapy. Among those genes, the tumor suppressor gene p53 is worthy of notice in cancer therapy, because the p53 molecule prevents the malignant degeneration of non-cancer cells by regulating cell-cycle arrest, apoptosis, and DNA repair. An abnormality of the p53 gene introduces a genetic instability and increases the incidence of carcinogenesis and teratogenesis. Therefore, p53 is called a guardian of the genome. Mutations of p53 are observed at a high frequency in human tumors, and are recognized in about half of all malignant tumors in human head and neck cancers. We previously reported that radio- and heat-sensitivities of human cultured tongue squamous cell carcinoma cells are p53-dependent, and are closely correlated with the induction of apoptosis. In a human cell culture system, the interactive hyperthermic enhancement of radiosensitivity was observed in wild-type p53 cells, but not in mutated p53 cells. In a transplanted tumor system, the combination therapies of radiation and hyperthermia induced efficient tumor growth depression and apoptosis in the wild-type p53 tumors. In this review, we discuss the p53 activation signaling pathways through the modification of p53 molecules, such as phosphorylation after radiation and hyperthermia treatments. (author)

Tumour suppressor protein p53 regulates the stress activated bilirubin oxidase cytochrome P450 2A6

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Hu, Hao, E-mail: hao.hu1@uqconnect.edu.au [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Yu, Ting, E-mail: t.yu2@uq.edu.au [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Arpiainen, Satu, E-mail: Satu.Juhila@orion.fi [Institute of Biomedicine, Department of Pharmacology and Toxicology and Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu (Finland); Lang, Matti A., E-mail: m.lang@uq.edu.au [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Hakkola, Jukka, E-mail: Jukka.hakkola@oulu.fi [Institute of Biomedicine, Department of Pharmacology and Toxicology and Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu (Finland); Abu-Bakar, A' edah, E-mail: a.abubakar@uq.edu.au [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia)

2015-11-15

Human cytochrome P450 (CYP) 2A6 enzyme has been proposed to play a role in cellular defence against chemical-induced oxidative stress. The encoding gene is regulated by various stress activated transcription factors. This paper demonstrates that p53 is a novel transcriptional regulator of the gene. Sequence analysis of the CYP2A6 promoter revealed six putative p53 binding sites in a 3 kb proximate promoter region. The site closest to transcription start site (TSS) is highly homologous with the p53 consensus sequence. Transfection with various stepwise deletions of CYP2A6-5′-Luc constructs – down to − 160 bp from the TSS – showed p53 responsiveness in p53 overexpressed C3A cells. However, a further deletion from − 160 to − 74 bp, including the putative p53 binding site, totally abolished the p53 responsiveness. Electrophoretic mobility shift assay with a probe containing the putative binding site showed specific binding of p53. A point mutation at the binding site abolished both the binding and responsiveness of the recombinant gene to p53. Up-regulation of the endogenous p53 with benzo[α]pyrene – a well-known p53 activator – increased the expression of the p53 responsive positive control and the CYP2A6-5′-Luc construct containing the intact p53 binding site but not the mutated CYP2A6-5′-Luc construct. Finally, inducibility of the native CYP2A6 gene by benzo[α]pyrene was demonstrated by dose-dependent increases in CYP2A6 mRNA and protein levels along with increased p53 levels in the nucleus. Collectively, the results indicate that p53 protein is a regulator of the CYP2A6 gene in C3A cells and further support the putative cytoprotective role of CYP2A6. - Highlights: • CYP2A6 is an immediate target gene of p53. • Six putative p53REs located on 3 kb proximate CYP2A6 promoter region. • The region − 160 bp from TSS is highly homologous with the p53 consensus sequence. • P53 specifically bind to the p53RE on the − 160 bp region. • HNF4�

Pigmentation, Melanocyte Colonization, and p53 Status in Basal Cell Carcinoma

International Nuclear Information System (INIS)

Frey, L. M.; Houben, R.; Brocker, E. B.

2011-01-01

Basal cell carcinoma (BCC) is the most common neoplasm in the Caucasian population. Only a fraction of BCC exhibits pigmentation. Lack of melanocyte colonization has been suggested to be due to p53-inactivating mutations in the BCC cells interfering with the p53-proopiomelanocortin pathway and the production of alpha melanocyte-stimulating hormone in the tumor. To evaluate this, we determined tumor pigmentation as well as expression of melan-A and of p53 in 49 BCC tissues by means of immunohistochemistry. As expected, we observed a positive relation between tumor pigmentation and melan-A positive intra-tumoral melanocytes. Melanocyte colonization and, to a lesser extent, p53 overexpression showed intraindividual heterogeneity in larger tumors. p53 overexpression, which is indicative of p53 mutations, was not correlated to melanocyte colonization of BCC. Sequencing of exon 5-8 of the p53 gene in selected BCC cases revealed that colonization by melanocytes and BCC pigmentation is neither ablated by p53 mutations nor generally present in BCCs with wild-type p53.

Therapeutic targeting of the p53 pathway in cancer stem cells

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Prabhu, Varun V.; Allen, Joshua E.; Hong, Bo; Zhang, Shengliang; Cheng, Hairong; El-Deiry, Wafik S.

2013-01-01

Introduction Cancer stem cells are a high profile drug target for cancer therapeutics due to their indispensable role in cancer progression, maintenance, and therapeutic resistance. Restoring wild-type p53 function is an attractive new therapeutic approach for the treatment of cancer due to the well-described powerful tumor suppressor function of p53. As emerging evidence intimately links p53 and stem cell biology, this approach also provides an opportunity to target cancer stem cells. Areas covered Therapeutic approaches to restore the function of wild-type p53, cancer and normal stem cell biology in relation to p53, and the downstream effects of p53 on cancer stem cells. Expert opinion The restoration of wild-type p53 function by targeting p53 directly, its interacting proteins, or its family members holds promise as a new class of cancer therapies. This review examines the impact that such therapies may have on normal and cancer stem cells based on the current evidence linking p53 signaling with these populations. PMID:22998602

Hypoxia-induced p53 modulates both apoptosis and radiosensitivity via AKT

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Leszczynska, Katarzyna B.; Foskolou, Iosifina P.; Abraham, Aswin G.; Anbalagan, Selvakumar; Tellier, Céline; Haider, Syed; Span, Paul N.; O’Neill, Eric E.; Buffa, Francesca M.; Hammond, Ester M.

2015-01-01

Restoration of hypoxia-induced apoptosis in tumors harboring p53 mutations has been proposed as a potential therapeutic strategy; however, the transcriptional targets that mediate hypoxia-induced p53-dependent apoptosis remain elusive. Here, we demonstrated that hypoxia-induced p53-dependent apoptosis is reliant on the DNA-binding and transactivation domains of p53 but not on the acetylation sites K120 and K164, which, in contrast, are essential for DNA damage–induced, p53-dependent apoptosis. Evaluation of hypoxia-induced transcripts in multiple cell lines identified a group of genes that are hypoxia-inducible proapoptotic targets of p53, including inositol polyphosphate-5-phosphatase (INPP5D), pleckstrin domain–containing A3 (PHLDA3), sulfatase 2 (SULF2), B cell translocation gene 2 (BTG2), cytoplasmic FMR1-interacting protein 2 (CYFIP2), and KN motif and ankyrin repeat domains 3 (KANK3). These targets were also regulated by p53 in human cancers, including breast, brain, colorectal, kidney, bladder, and melanoma cancers. Downregulation of these hypoxia-inducible targets associated with poor prognosis, suggesting that hypoxia-induced apoptosis contributes to p53-mediated tumor suppression and treatment response. Induction of p53 targets, PHLDA3, and a specific INPP5D transcript mediated apoptosis in response to hypoxia through AKT inhibition. Moreover, pharmacological inhibition of AKT led to apoptosis in the hypoxic regions of p53-deficient tumors and consequently increased radiosensitivity. Together, these results identify mediators of hypoxia-induced p53-dependent apoptosis and suggest AKT inhibition may improve radiotherapy response in p53-deficient tumors. PMID:25961455

Polimorfismo do gene tp53 no códon 72 em pacientes com suspeita de LMC Codon 72 polymorphism of the TP53 gene in patients suspected to have CML

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Camila S. Hamú

2007-12-01

Full Text Available A leucemia mielóide crônica (LMC é uma doença proliferativa do sistema hematopoiético, caracterizada pela expansão clonal de uma célula-tronco primitiva e pluripotente denominada stem cell. Este tipo de leucemia está associado, em 90% dos casos, à translocação t(9;22(q34;q11. Essa alteração cromossômica estrutural codifica para uma proteína quimérica BCR-ABL, que confere às células leucêmicas uma alta resistência à morte, independente do agente indutor desse processo. A proteína p53 é uma reguladora transcricional induzida por danos no DNA, fato que resulta na parada do ciclo celular com conseqüente ativação de mecanismos de reparo ou mesmo na indução à apoptose. As mutações no gene TP53 são as alterações genéticas mais comuns em tumores malignos humanos. O presente estudo teve como objetivo genotipar e determinar a freqüência alélica do polimorfismo do TP53 no códon 72 (arginina - Arg e prolina - Pro, em pacientes com suspeita de LMC, pela Reação em Cadeia da Polimerase. Desta forma, os resultados indicaram que 73,4% (23/30 dos pacientes apresentaram homozigose para arginina (Arg/Arg e 26,6% (7/30 heterozigose (Arg/Pro. Não foi encontrado nenhum paciente homozigoto para prolina (Pro/Pro. Os resultados obtidos sugerem que o polimorfismo do gene TP53 no códon 72 não é um fator de risco importante para a iniciação, promoção e progressão da LMC.Chronic myeloid leukemia (CML is a proliferative disorder of the hematopoietic system characterized by clonal expansion of a primitive and pluripotent stem cell. In this type of leukemia, up to 90% of all cases is associated to a specific chromosomal translocation, t(9;22(q34;q11. The genomic alteration results in a chimeric protein, BCR-ABL, that confers a high resistance leukemia cells to death, independent of the induction mechanism of this process. Protein p53 is a transcriptional factor expressed after DNA damage which ceases cell cycle progression and

Germ-line mutations of the p53 tumor suppressor gene in patients with high risk for cancer inactivate the p53 protein.

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Frebourg, T; Kassel, J; Lam, K T; Gryka, M A; Barbier, N; Andersen, T I; Børresen, A L; Friend, S H

1992-07-15

Germ-line mutations in the p53 tumor suppressor gene have been observed in patients with Li-Fraumeni syndrome, brain tumors, second malignancies, and breast cancers. It is unclear whether all of these mutations have inactivated p53 and thereby provide an increased risk for cancer. Therefore, it is necessary to establish the biological significance of these germ-line mutations by the functional and structural analysis of the resulting mutant p53 proteins. We analyzed the ability of seven germ-line mutant proteins observed in patients with Li-Fraumeni syndrome, second primary neoplasms, or familial breast cancer to block the growth of malignant cells and compared the structural properties of the mutant proteins to that of the wild-type protein. Six of seven missense mutations disrupted the growth inhibitory properties and structure of the wild-type protein. One germ-line mutation retained the features of the wild-type p53. Genetic analysis of the breast cancer family in which this mutation was observed indicated that this germ-line mutation was not associated with the development of cancer. These results demonstrate that germ-line p53 mutations observed in patients with Li-Fraumeni syndrome and with second malignancies have inactivated the p53 tumor suppressor gene. The inability of the germ-line p53 mutants to block the growth of malignant cells can explain why patients with these germ-line mutations have an increased risk for cancer. The observation of a functionally silent germ-line mutation indicates that, before associating a germ-line tumor suppressor gene mutation with cancer risk, it is prudent to consider its functional significance.

Germ-line mutations of the p53 tumor suppressor gene in patients with high risk for cancer inactivate the p53 protein.

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Frebourg, T; Kassel, J; Lam, K T; Gryka, M A; Barbier, N; Andersen, T I; Børresen, A L; Friend, S H

1992-01-01

Germ-line mutations in the p53 tumor suppressor gene have been observed in patients with Li-Fraumeni syndrome, brain tumors, second malignancies, and breast cancers. It is unclear whether all of these mutations have inactivated p53 and thereby provide an increased risk for cancer. Therefore, it is necessary to establish the biological significance of these germ-line mutations by the functional and structural analysis of the resulting mutant p53 proteins. We analyzed the ability of seven germ-line mutant proteins observed in patients with Li-Fraumeni syndrome, second primary neoplasms, or familial breast cancer to block the growth of malignant cells and compared the structural properties of the mutant proteins to that of the wild-type protein. Six of seven missense mutations disrupted the growth inhibitory properties and structure of the wild-type protein. One germ-line mutation retained the features of the wild-type p53. Genetic analysis of the breast cancer family in which this mutation was observed indicated that this germ-line mutation was not associated with the development of cancer. These results demonstrate that germ-line p53 mutations observed in patients with Li-Fraumeni syndrome and with second malignancies have inactivated the p53 tumor suppressor gene. The inability of the germ-line p53 mutants to block the growth of malignant cells can explain why patients with these germ-line mutations have an increased risk for cancer. The observation of a functionally silent germ-line mutation indicates that, before associating a germ-line tumor suppressor gene mutation with cancer risk, it is prudent to consider its functional significance. Images PMID:1631137

Paracrine Apoptotic Effect of p53 Mediated by Tumor Suppressor Par-4

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Ravshan Burikhanov

2014-01-01

Full Text Available The guardian of the genome, p53, is often mutated in cancer and may contribute to therapeutic resistance. Given that p53 is intact and functional in normal tissues, we harnessed its potential to inhibit the growth of p53-deficient cancer cells. Specific activation of p53 in normal fibroblasts selectively induced apoptosis in p53-deficient cancer cells. This paracrine effect was mediated by p53-dependent secretion of the tumor suppressor Par-4. Accordingly, the activation of p53 in normal mice, but not p53−/− or Par-4−/− mice, caused systemic elevation of Par-4, which induced apoptosis of p53-deficient tumor cells. Mechanistically, p53 induced Par-4 secretion by suppressing the expression of its binding partner, UACA, which sequesters Par-4. Thus, normal cells can be empowered by p53 activation to induce Par-4 secretion for the inhibition of therapy-resistant tumors.

Germ-line mutations of the p53 tumor suppressor gene in patients with high risk for cancer inactivate the p53 protein.

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Frebourg, T; Kassel, J; Lam, K T; Gryka, M A; Barbier, N; Andersen, T I; Børresen, A L; Friend, S H

1992-01-01

Germ-line mutations in the p53 tumor suppressor gene have been observed in patients with Li-Fraumeni syndrome, brain tumors, second malignancies, and breast cancers. It is unclear whether all of these mutations have inactivated p53 and thereby provide an increased risk for cancer. Therefore, it is necessary to establish the biological significance of these germ-line mutations by the functional and structural analysis of the resulting mutant p53 proteins. We analyzed the ability of seven germ-...

Apoptosis in spermatogonia irradiated P53 null mice

International Nuclear Information System (INIS)

Streit-Bianchi, M.; Hendry, J.H.; Roberts, S.A.; Morris, J.D.; Durgaryan, A.A.

2007-01-01

Complete text of publication follows. The exposure of germ cells to ionizing radiations is of concern both from high-dose therapeutic exposures and from low doses causing deleterious trans-generational mutations. P53 protein plays an important role in cellular damage and is expressed in the testis normally during meiosis, its expression being localised to the preleptotene and early/mid pachytene spermatocytes. P53 null mice, heterozygotes possessing a 129 Sv/C57BL6 genetic background and B6D2F1 mice have been irradiated to 1 and 2 Gy single doses. Fractionated exposures of 1+1 Gy at 4 hours interval were also carried out. Apoptosis induction, spermatogonia and spermatocytes survival were assessed by microscope analysis of histological samples at 4 to 96 hours after irradiation in time-course experiments. The same end-points were also assessed at 72 and 96 hours after irradiation to single doses in the region between 20cGy to 2Gy. A dose dependent level of p53 expression was observed at 4 hours after irradiation to 1 and 2 Gy which returned to normal level by 24 hours. Our data support a two process mode of apoptosis with a first wave around 12 hours followed by a second wave at 2-3 days. The first wave apoptosis is substantially reduced in p53 null mice whereas the second wave is reduced in B6D2F1 mice. The initial increase in apoptosis was delayed in some stages of the of germ cells development which were identified by the spermatids shape. Clear correlation exists between apoptosis and survival assessed in stage XI-XII Tubules 72 hours after irradiation. The data are in agreement with other data in literature indicating that irradiated spermatogonia die through apoptosis. The lack of apoptosis observed in p53 null mice results in a very high survival rate of daughter cells assessed later. Theses spermatocytes and the following progenitor cells are likely to carry mutations as most will not die in the smaller second wave of apoptosis observed 3 days after

Pax3 stimulates p53 ubiquitination and degradation independent of transcription.

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Xiao Dan Wang

Full Text Available Pax3 is a developmental transcription factor that is required for neural tube and neural crest development. We previously showed that inactivating the p53 tumor suppressor protein prevents neural tube and cardiac neural crest defects in Pax3-mutant mouse embryos. This demonstrates that Pax3 regulates these processes by blocking p53 function. Here we investigated the mechanism by which Pax3 blocks p53 function.We employed murine embryonic stem cell (ESC-derived neuronal precursors as a cell culture model of embryonic neuroepithelium or neural crest. Pax3 reduced p53 protein stability, but had no effect on p53 mRNA levels or the rate of p53 synthesis. Full length Pax3 as well as fragments that contained either the DNA-binding paired box or the homeodomain, expressed as GST or FLAG fusion proteins, physically associated with p53 and Mdm2 both in vitro and in vivo. In contrast, Splotch Pax3, which causes neural tube and neural crest defects in homozygous embryos, bound weakly, or not at all, to p53 or Mdm2. The paired domain and homeodomain each stimulated Mdm2-mediated ubiquitination of p53 and p53 degradation in the absence of the Pax3 transcription regulatory domains, whereas Splotch Pax3 did not stimulate p53 ubiquitination or degradation.Pax3 inactivates p53 function by stimulating its ubiquitination and degradation. This process utilizes the Pax3 paired domain and homeodomain but is independent of DNA-binding and transcription regulation. Because inactivating p53 is the only required Pax3 function during neural tube closure and cardiac neural crest development, and inactivating p53 does not require Pax3-dependent transcription regulation, this indicates that Pax3 is not required to function as a transcription factor during neural tube closure and cardiac neural crest development. These findings further suggest novel explanations for PAX3 functions in human diseases, such as in neural crest-derived cancers and Waardenburg syndrome types 1 and 3.

p63 expression confers significantly better survival outcomes in high-risk diffuse large B-cell lymphoma and demonstrates p53-like and p53-independent tumor suppressor function

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Xu-Monette, Zijun Y; Zhang, Shanxiang; Li, Xin

2016-01-01

with a pan-p63-monoclonal antibody and correlated it with other clinicopathologic factors and clinical outcomes. p63 expression was observed in 42.5% of DLBCL, did not correlate with p53 levels, but correlated with p21, MDM2, p16INK4A, Ki-67, Bcl-6, IRF4/MUM-1 and CD30 expression, REL gains, and BCL6...... was likely due to the association of p63 expression with high-risk IPI, and potential presence of ∆Np63 isoform in TP63 rearranged patients (a mere speculation). Gene expression profiling suggested that p63 has both overlapping and distinct functions compared with p53, and that p63 and mutated p53 antagonize...

Cuidar o doente com tuberculose pulmonar – ensinar para viver melhor

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Maria B.M.P. Cristino

1996-11-01

Full Text Available RESUMO: Além de implementarmos medidas de isolamento dos doentes com Tuberculose pulmonary, investimos na educação para a saúde, através do ensino organizodo, com o objectivo de motivar o doente a participar de forma activa no seu tratmento. Foi também elaborado um folheto Informativo para complemento do ensinmo efectuado.Após a realização do ensino, foi aplicado um questionário a·vinte doentes, o qual permitiu avaliar os conhecinmentos por eles adquiridos.Da análise global dos resultados do questionário verificámos que 13 (65% doentes responderam correctamente a todas as perguntas e 7 (35% erraram apenas uma pergunta. SUMMARY: Besides implementing isolation measures the patients with pulmonary tuberculosis, we invested in education for health through organised teaching, being our objective the motivation of the patient to activity, we also elaborated on informative handout.After the teaching activity was carried out, a questionnaire was completed by twenty patients, which gave us information about the specific knowledge learnt by each of them.Results showed that 13 (65% patients answered correctly all the questions while 7 (35% failed only one question. Palvaras-chave: Tuberculose, Enfermeiras, Ensino

p53-dependent non-coding RNA networks in chronic lymphocytic leukemia

NARCIS (Netherlands)

Blume, C. J.; Hotz-Wagenblatt, A.; Hüllein, J.; Sellner, L.; Jethwa, A.; Stolz, T.; Slabicki, M.; Lee, K.; Sharathchandra, A.; Benner, A.; Dietrich, S.; Oakes, C. C.; Dreger, P.; te Raa, D.; Kater, A. P.; Jauch, A.; Merkel, O.; Oren, M.; Hielscher, T.; Zenz, T.

2015-01-01

Mutations of the tumor suppressor p53 lead to chemotherapy resistance and a dismal prognosis in chronic lymphocytic leukemia (CLL). Whereas p53 targets are used to identify patient subgroups with impaired p53 function, a comprehensive assessment of non-coding RNA targets of p53 in CLL is missing. We

Thymocyte apoptosis induced by p53-dependent and independent pathways

International Nuclear Information System (INIS)

Clarke, A.R.; Purdie, C.A.; Harrison, D.J.; Morris, R.G.; Bird, C.C.; Hooper, M.L.; Wyllie, A.H.

1993-01-01

The authors studied the dependence of apoptosis on p53 expression in cells from the thymus cortex. Short-term thymocyte cultures were prepared from mice constitutively heterozygous or homozygous for a deletion in the p53 gene introduced into the germ line after gene targeting. Wild-type thymocytes readily undergo apoptosis after treatment with ionizing radiation, the glucocorticoid methylprednisolone, or etoposide (an inhibitor of topoisomerase II), or after Ca 2+ -dependent activation by phorbol ester and a calcium ionophore. In contrast, homozygous null p53 thymocytes are resistant to induction of apoptosis by radiation or etoposide, but retain normal sensitivity to glucocorticoid and calcium. The time-dependent apoptosis that occurs in untreated cultures is unaffected by p53 status. Cells heterozygous for p53 deletion are partially resistant to radiation and etoposide. Results show that p53 exerts a significant and dose-dependent effect in the initiation of apoptosis, but only when it is induced by agents that cause DNA-strand breakage. (Author)

Interaction of p53 with prolyl isomerases: Healthy and unhealthy relationships.

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Mantovani, Fiamma; Zannini, Alessandro; Rustighi, Alessandra; Del Sal, Giannino

2015-10-01

The p53 protein family, comprising p53, p63 and p73, is primarily involved in preserving genome integrity and preventing tumor onset, and also affects a range of physiological processes. Signal-dependent modifications of its members and of other pathway components provide cells with a sophisticated code to transduce a variety of stress signaling into appropriate responses. TP53 mutations are highly frequent in cancer and lead to the expression of mutant p53 proteins that are endowed with oncogenic activities and sensitive to stress signaling. p53 family proteins have unique structural and functional plasticity, and here we discuss the relevance of prolyl-isomerization to actively shape these features. The anti-proliferative functions of the p53 family are carefully activated upon severe stress and this involves the interaction with prolyl-isomerases. In particular, stress-induced stabilization of p53, activation of its transcriptional control over arrest- and cell death-related target genes and of its mitochondrial apoptotic function, as well as certain p63 and p73 functions, all require phosphorylation of specific S/T-P motifs and their subsequent isomerization by the prolyl-isomerase Pin1. While these functions of p53 counteract tumorigenesis, under some circumstances their activation by prolyl-isomerases may have negative repercussions (e.g. tissue damage induced by anticancer therapies and ischemia-reperfusion, neurodegeneration). Moreover, elevated Pin1 levels in tumor cells may transduce deregulated phosphorylation signaling into activation of mutant p53 oncogenic functions. The complex repertoire of biological outcomes induced by p53 finds mechanistic explanations, at least in part, in the association between prolyl-isomerases and the p53 pathway. This article is part of a Special Issue entitled Proline-directed foldases: Cell signaling catalysts and drug targets. Copyright © 2015 Elsevier B.V. All rights reserved.

Estudo dos factores limitativos do exercício físico em doentes com doença pulmonar obstrutiva crónica

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Fátima Rodrigues

2004-01-01

Full Text Available RESUMO: A Doença Pulmonar Obstrutiva Crónica (DPOC é uma das principais causas de morbilidade e mortalidade em todo o mundo. Os doentes com DPOC moderada/grave apresentam, com frequência, intolerância ao exercício físico nas actividades da vida diária, o que afecta a sua qualidade de vida. São apontadas na literatura diversas causas para a diminuição da tolerância ao exercício físico: a obstrução brônquica, a hiperinsuflação pulmonar, a fraqueza dos músculos respiratórios e dos músculos periféricos, entre outras.O presente trabalho teve por objectivo identificar os factores potencialmente implicados na limitação do exercício num grupo de doentes com DPOC moderada a grave.Estudaram-se 24 doentes do sexo masculino com 64,13+8,46 anos (46-83 anos, FEV1:46,96 + + 12,99% do teórico, FRC: 144,71+26,86% do teórico, DLCO: 69,88+16,49 % teórico, PaO2:78,25+7,82 mmHg, PaCO2:40,78+4,28 mmHg. Os doentes foram submetidos a um teste incremental progressivo limitado por sintomas em cicloergómetro. Correlacionaram-se os parâmetros funcionais em repouso e no exercício com o consumo máximo de oxigénio, a carga suportada e a duração da prova.Os factores que contribuíram de forma mais significativa para a limitação do desempenho no exercício foram a alteração das trocas gasosas, a limitação ventilatória e um menor índice de massa corporal na avaliação nutricional.A hiperinsuflação pulmonar avaliada em repouso não se correlacionou com o desempenho no exercício. Quanto à hiperinsuflação pulmonar no exercício, contribuiu de forma importante para a intolerância ao esforço, através da restrição progressiva à expansão do volume corrente necessária para fazer face ao aumento das exigências metabólicas do exercício.Os parâmetros funcionais avaliados em repouso n

HEXIM1, a New Player in the p53 Pathway

Energy Technology Data Exchange (ETDEWEB)

Lew, Qiao Jing; Chu, Kai Ling; Chia, Yi Ling; Cheong, Nge [Expression Engineering Group, Bioprocessing Technology Institute, A*STAR (Agency for Science, Technology and Research), 20 Biopolis Way, #06-01, Singapore 138668 (Singapore); Chao, Sheng-Hao, E-mail: jimmy_chao@bti.a-star.edu.sg [Expression Engineering Group, Bioprocessing Technology Institute, A*STAR (Agency for Science, Technology and Research), 20 Biopolis Way, #06-01, Singapore 138668 (Singapore); Department of Microbiology, National University of Singapore, Singapore 117597 (Singapore)

2013-07-04

Hexamethylene bisacetamide-inducible protein 1 (HEXIM1) is best known as the inhibitor of positive transcription elongation factor b (P-TEFb), which controls transcription elongation of RNA polymerase II and Tat transactivation of human immunodeficiency virus. Besides P-TEFb, several proteins have been identified as HEXIM1 binding proteins. It is noteworthy that more than half of the HEXIM1 binding partners are involved in cancers. P53 and two key regulators of the p53 pathway, nucleophosmin (NPM) and human double minute-2 protein (HDM2), are among the factors identified. This review will focus on the functional importance of the interactions between HEXIM1 and p53/NPM/HDM2. NPM and the cytoplasmic mutant of NPM, NPMc+, were found to regulate P-TEFb activity and RNA polymerase II transcription through the interaction with HEXIM1. Importantly, more than one-third of acute myeloid leukemia (AML) patients carry NPMc+, suggesting the involvement of HEXIM1 in tumorigenesis of AML. HDM2 was found to ubiquitinate HEXIM1. The HDM2-mediated ubiquitination of HEXIM1 did not lead to protein degradation of HEXIM1 but enhanced its inhibitory activity on P-TEFb. Recently, HEXIM1 was identified as a novel positive regulator of p53. HEXIM1 prevented p53 ubiquitination by competing with HDM2 in binding to p53. Taken together, the new evidence suggests a role of HEXIM1 in regulating the p53 pathway and tumorigenesis.

Regulation of Mdmx and its role in the p53 pathway

NARCIS (Netherlands)

Meulmeester, Erik

2006-01-01

The p53 protein is an important tumor suppressor that acts as a key regulator of the integrity of the genome. Two essential regulators of the p53 protein are Mdm2 and its homologue Mdmx. Like Mdm2, Mdmx represses p53-induced transcription. However, Mdmx cannot ubiquitinate or degrade p53 opposed to

p53 expression in biopsies from children with Langerhans cell histiocytosis

DEFF Research Database (Denmark)

Bank, Micha I; Lundegaard, Pia Rengtved; Carstensen, Henrik

2002-01-01

based on CD1a positivity. The slides were stained with p53 antibody and semiquantitatively evaluated using a grading system from 1 to 5 as an estimate for 0% to 20%, 20% to 40%, 40% to 60%, 60% to 80%, and 80% to 100% p53-positive for pathologic Langerhans cells (pLC), respectively. RESULTS: The p53...... protein was expressed in various degrees in pLC in all lesions. The degree of p53 expression could not be correlated to either clinical manifestation or outcome. CONCLUSIONS: An increased expression of p53 in pLC indicates an altered DNA repair control with or without abnormal control of apoptosis....

Aeromonas spp. IN PRODUCTS OF ANIMAL ORIGIN AND DRINKING WATER OF GOIÂNIA-GO Aeromonas spp. EM PRODUTOS DE ORIGEM ANIMAL E EM ÁGUA DE CONSUMO DE GOIÂNIA - GO

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Albenones José de Mesquita

2007-09-01

Full Text Available <p class="western" align="justify">A total of 53 samples of products from animal origin and drinking water was examined for the presence of <em>Aeromonas spp.em> <em>Aeromonas> occurred in 26.41% (14/53 of the samples. The raw products showed high frequency of contamination and relatively high count Aeromonas hydrophila was the dominating species, 57.5%, being followed of <em>A. veroniem> (22.5%, <em>A. sobriaem> (17.5% and <em>A. mediaem> (2.5%. None of the <em>Aeromonas sppem>. was isolated from chlorinated or unchlorinated drinking water.p> <p class="western" align="justify">KEY-WORDS: <em>Aeromonas>; animal origin products; drinking water.p> <p class="western" align="justify">Um total de 53 amostras de produtos de origem animal e água de consumo foi examinado para se verificar a presença de <em>Aeromonas> <em>spp>. Desse total, 14/53 (26,41% amostras foram positivas para <em>Aeromonas>. Os produtos crus apresentaram maior freqüência de contaminação e contagem relativamente elevadas. A espécie <em>Aeromonas> <em>hydrophila> foi a mais freqüente (57,5%, seguida pelas espécies <em>A. veroniem> (22,5%, <em>A. sobriaem> (17,5% e A. media (2,5%. Nenhuma amostra de água de consumo, clorada ou não clorada, mostrou-se positiva para <em>Aeromonas> <em>ssp.> <p class="western" align="justify">PALAVRA-CHAVE: <em>Aeromonas>; produtos de origem animal; água de consumo.p>

Morphological Heterogeneity of p53 Positive and p53 Negative Nuclei in Breast Cancers Stratified by Clinicopathological Variables

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Katrin Friedrich

1997-01-01

Full Text Available The study was aimed to detect differences in nuclear morphology between nuclear populations as well as between tumours with different p53 expression in breast cancers with different clinicopathological features, which also reflect the stage of tumour progression. The p53 immunohistochemistry was performed on paraffin sections from 88 tumour samples. After the cells had been localised by means of an image cytometry workstation and their immunostaining had been categorised visually, the sections were destained and stained by the Feulgen protocol. The nuclei were relocated and measured cytometrically by the workstation.

Mutual interactions between P53 and growth factors in cancer

NARCIS (Netherlands)

Asschert, JGW; Vellenga, E; De Jong, S; De Vries, EGE

1998-01-01

The function of p53 armour suppressor protein is determined by various intrinsic properties of the protein. The effect of p53 DNA-binding, and platein-protein interactions are determined by the conformation of the protein. Thus p53 fulfils its role in cell cycle control and the onset of apoptotic

DNA double strand break repair is enhanced by P53 following induction by DNA damage and is dependent on the C-terminal domain of P53

International Nuclear Information System (INIS)

Wei Tang; Powell, Simon N.

1996-01-01

Purpose: The tumor suppressor gene p53 can mediate cell cycle arrest or apoptosis in response to DNA damage. Accumulating evidence suggests that it may also directly or indirectly influence the DNA repair machinery. In the present study, we investigated whether p53, induced by DNA damage, could enhance the rejoining of double-strand DNA breaks. Materials and Methods: DNA double-strand breaks (dsb) were made by restriction enzyme digestion of a plasmid, between a promoter and a 'reporter' gene: luciferase (LUC) or chloramphenicol acetyl-transferase (CAT). Linear or circular plasmid DNA (LUC or CAT) was co-transfected with circular β-Gal plasmid (to normalize for uptake) into mouse embryonic fibroblasts genetically matched to be (+/+) or (-/-) for p53. Their ability to rejoin linearized plasmid was measured by the luciferase or CAT activity detected in rescued plasmids. The activity detected in cells transfected with linear plasmid was scored relative to the activity detected in cells transfected with circular plasmid. Results: Ionizing radiation (IR, 2 Gy) enhanced the dsb repair activity in wild type p53 cells; however, p53 null cells lose this effect, indicating that the enhancement of dsb repair was p53-dependent. REF cells with dominant-negative mutant p53 showed a similar induction compared with the parental REF cells with wild-type p53. This ala-143 mutant p53 prevents cell cycle arrest and transactivation of p21 WAF1/cip1) following IR, indicating that the p53-dependent enhancement of DNA repair is distinct from transactivation. Immortalized murine embryonic fibroblasts, 10(1)VasK1 cells, which express p53 cDNA encoding a temperature-sensitive mutant in the DNA sequence specific binding domain (ala135 to val135) with an alternatively spliced C-terminal domain (ASp53: amino-acids 360-381) and, 10(1)Val5 cells, which express the normal spliced p53 (NSp53) with the same temperature-sensitive mutant were compared. It was found that 10(1)VasK1 cells showed no DNA

Restriction of human herpesvirus 6B replication by p53

DEFF Research Database (Denmark)

Øster, Bodil; Kofod-Olsen, Emil; Bundgaard, Bettina

2008-01-01

Human herpesvirus 6B (HHV-6B) induces significant accumulation of p53 in both the nucleus and cytoplasm during infection. Activation of p53 by DNA damage is known to induce either growth arrest or apoptosis; nevertheless, HHV-6B-infected cells are arrested in their cell cycle independently of p53...

Reacção paradoxal da pressão arterial ao tratamento com pressão positiva na via aérea em doentes com apneia do sono

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C. Chaves Loureiro

2011-03-01

Full Text Available Resumo: Introdução: Doentes com síndrome de Apneia Obstrutiva do Sono (SAOS podem desenvolver hipertensão arterial (HTA sendo a pressão positiva na via aérea (PAP um tratamento eficaz no controlo da pressão arterial (PA. Objectivos: Analisar uma população de doentes com SAOS que desenvolveu aumento inesperado da PA após o uso de PAP e verificar a existência de correlações entre o aumento da PA, quer com os índices de gravidade da SAOS, quer com a adesão ao tratamento com suporte ventilatório nocturno. Métodos: Análise retrospectiva e descritiva de 30 doentes com SAOS e hipertensão previamente controlada, tratados com PAP, em média durante um ano, que desenvolveram um aumento da pressão arterial, definida como aumento de 5 mmHg na Pressão Arterial Sistólica (PAS e/ou Diastólica (PAD, após instituição de terapêutica PAP. Análise correlativa do aumento da PA com os índices de gravidade da SAOS e com a adesão ao tratamento, utilizando o coeficiente de Pearson. Resultados: De 508 doentes consecutivos seguidos no nosso Departamento, tratados com suporte ventilatório nocturno, 30 evoluíram com aumento de PA após o início do tratamento (idade 58 anos (SD 10,8, índice de Apneia-Hipopneia (IAH 46,1 (SD 18,68. Após o uso de PAP, a variação da Pressão Arterial Média (PAM, da PAS e da PAD foi, respectivamente, de 16 mmHg, 20 mmHg e 6 mmHg (SD: 15,0; 25,0; 19,4. Nenhum doente mostrou aumento significativo de Índice de Massa Corporal (IMC. O valor da Escala de Sonolência de Epworth (ESE diminuiu 8,9 pontos (SD 5,48. As variações de PAM, PAS e PAD não se relacionaram com P90/P95, IAH residual, fugas ou adesão a PAP. Conclusões: Neste grupo que desenvolveu um aumento da PA com o uso de PAP não se identificaram características específicas. Não foram encontradas correlações entre os aumentos

A última escolha: repensar a morte em vida

OpenAIRE

Roque, Margarida Abenta

2010-01-01

Tese de mestrado, Filosofia, Universidade de Lisboa, Faculdade de Letras, 2010 A presente dissertação de mestrado em Filosofia, intitulada A última escolha: repensar a morte em vida, consistirá numa análise expositiva de natureza ética das opções de final de vida que se colocam aos indivíduos doentes ou em estado terminal, abstendo-se de juízos de matriz legal ou jurídica. Tomando Peter Singer como autor de referência intelectual nesta dissertação, o nosso ponto de partida cons...

Andrographolide induces degradation of mutant p53 via activation of Hsp70.

Science.gov (United States)

Sato, Hirofumi; Hiraki, Masatsugu; Namba, Takushi; Egawa, Noriyuki; Baba, Koichi; Tanaka, Tomokazu; Noshiro, Hirokazu

2018-05-22

The tumor suppressor gene p53 encodes a transcription factor that regulates various cellular functions, including DNA repair, apoptosis and cell cycle progression. Approximately half of all human cancers carry mutations in p53 that lead to loss of tumor suppressor function or gain of functions that promote the cancer phenotype. Thus, targeting mutant p53 as an anticancer therapy has attracted considerable attention. In the current study, a small-molecule screen identified andrographlide (ANDRO) as a mutant p53 suppressor. The effects of ANDRO, a small molecule isolated from the Chinese herb Andrographis paniculata, on tumor cells carrying wild-type or mutant p53 were examined. ANDRO suppressed expression of mutant p53, induced expression of the cyclin-dependent kinase inhibitor p21 and pro-apoptotic proteins genes, and inhibited the growth of cancer cells harboring mutant p53. ANDRO also induced expression of the heat-shock protein (Hsp70) and increased binding between Hsp70 and mutant p53 protein, thus promoting proteasomal degradation of p53. These results provide novel insights into the mechanisms regulating the function of mutant p53 and suggest that activation of Hsp70 may be a new strategy for the treatment of cancers harboring mutant p53.

AVALIAÇÃO DA FLORA MICROBIANA E DE DEGERMAÇÃO EXPERIMENTAL EM EQUIPE DE ENFERMAGEM, AMBIENTE E MATERIAL SANITÁRIO, EM ENFERMARIA DE ORTOPEDIA E TRAUMATOLOGIA

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Celina de Arruda Camargo

1972-09-01

Full Text Available RESUMO Estudou-se a ecologia dos microrganismos aeróbios patogênicos em duas Enfermarias de Ortopedia e Traumatologia, observando-se predomínio de bactérias Gram negativas. A etiologia das infecções, adquiridas ou não no hospital, dos doentes internados, mostrou também predomínio acentuado de bactérias Gram negativas. As mãos e narinas de funcionários em contato direto com os doentes, mostraram presença de flora bacteriana aeróbia mista constituída de Gram positivos (patogênico e não patogênicos e Gram negativos. Os resultados obtidos com a antissepsia de utensílios sanitários com solução contendo composto quaternário de amônio, metanol e etanol foram excelentes.

Mutations in the p53 homolog p63: allele-specific developmental syndromes in humans.

NARCIS (Netherlands)

Bokhoven, J.H.L.M. van; McKeon, F.

2002-01-01

p63 is the most recently discovered but most ancient member of the p53 family. In marked contrast to p53, p63 is highly expressed in embryonic ectoderm and in the basal, regenerative layers of many epithelial tissues in the adult. The p63-knockout mouse dies at birth and lacks limbs, epidermis,

Cisplatinum and Taxol Induce Different Patterns of p53 Phosphorylation

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Giovanna Damia

2001-01-01

Full Text Available Posttranslational modifications of p53 induced by two widely used anticancer agents, cisplatinum (DDP and taxol were investigated in two human cancer cell lines. Although both drugs were able to induce phosphorylation at serine 20 (Ser20, only DDP treatment induced p53 phosphorylation at serine 15 (Ser15. Moreover, both drug treatments were able to increase p53 levels and consequently the transcription of waf1 and mdm-2 genes, although DDP treatment resulted in a stronger inducer of both genes. Using two ataxia telangiectasia mutated (ATM cell lines, the role of ATM in druginduced p53 phosphorylations was investigated. No differences in drug-induced p53 phosphorylation could be observed, indicating that ATM is not the kinase involved in these phosphorylation events. In addition, inhibition of DNA-dependent protein kinase activity by wortmannin did not abolish p53 phosphorylation at Ser15 and Ser20, again indicating that DNA-PK is unlikely to be the kinase involved. After both taxol and DDP treatments, an activation of hCHK2 was found and this is likely to be responsible for phosphorylation at Ser20. In contrast, only DDP was able to activate ATR, which is the candidate kinase for phosphorylation of Ser15 by this drug. This data clearly suggests that differential mechanisms are involved in phosphorylation and activation of p53 depending on the drug type.

The pro-survival function of p53 in HeLa cells

Energy Technology Data Exchange (ETDEWEB)

Kim, Jin Kyu; Kang, Mi Young; Jang, Eun Yeong; Kim, Jin Hong [Korea Atomic Energy Research Institute, Advanced Radiation Technology Institute, Jeongeup (Korea, Republic of)

2014-11-15

The rate of apoptosis and autophagy was variable with different p53 status after IR treatment of cells. The influence of p53 status on cell fate suggests a role of p53 in two fundamentally important cell biological pathways: autophagy and apoptosis. p53 coordinates cell cycle arrest and apoptosis to govern cell fate. This study was done to identify p53-mediated regulation of cell's fate. Autophagy induced by IR may prevent cells from undergoing apoptosis, implying an interlink modulation between autophagy and apoptosis. The rate of apoptosis and autophagy was determined with different p53 status after IR treatment of HeLa cells in this study. Our research on IR-induced cellular responses may provide new information about fate decision between the processes of apoptosis and autophagy.

Adenocarcinoma do pulmão em doente com esclerodermia: Um caso clínico

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João Bento

2009-01-01

Full Text Available Resumo: A esclerodermia é uma doença do tecido conjuntivo de etiologia desconhecida, que tem sido associada a um risco acrescido de malignidade. O cancro do pulmão é a neoplasia mais frequente, nestes doentes.Apresenta-se o caso clínico de uma mulher de 42 anos, não fumadora, com esclerodermia, que desenvolveu agravamento progressivo do seu estado geral e derrame pleural com características de exsudado, sem evidência de infecção ou malignidade. A TAC torácica mostrou zonas de fibrose, a broncofibroscopia, os lavados brônquico e broncoalveolar foram normais. Foi excluída neoplasia extrapulmonar. Na pleuroscopia, observaram-se formações nodulares, cujas biópsias revelaram tratar-se de adenocarcinoma pulmonar. Iniciou quimioterapia, desenvolvendo ao 48.º dia neutropenia febril e sépsis, vindo a morrer 12 dias depois.Salientamos este caso pela relação, apesar de rara, entre a esclerodermia e o cancro do pulmão e pela importância de uma vigilância pulmonar cuidadosa, em indivíduos com esta doença reumatológica, pelo risco acrescido de neoplasia.Rev Port Pneumol 2009; XV (1: 93-99 Abstract: Systemic sclerosis (scleroderma is a connective tissue disorder of unknown aetiology characterised by immune abnormalities, which has been related to an increased risk of malignancy. Lung cancer is the most prevalent among these patients.We present a clinical case of a 42 years old non smoker female with systemic sclerosis. She presented progressive general health status worsening and an exudative pleural effusion, with no evidence of infection or malignancy. Chest high resolution computed tomography revealed pulmonary fibrosis. Bronchoscopy, bronchial and bronchoalveolar lavage were normal. Extra-pulmonary malignancies were excluded. Pleural nodularities were found on pleuroscopy and the biopsy was compatible with lung adenocarcinoma. Chemotherapy was then started, which complicated with febrile neutropenia, sepsis and patient death 12

Mutant Mice Lacking the p53 C-Terminal Domain Model Telomere Syndromes

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Iva Simeonova

2013-06-01

Full Text Available Mutations in p53, although frequent in human cancers, have not been implicated in telomere-related syndromes. Here, we show that homozygous mutant mice expressing p53Δ31, a p53 lacking the C-terminal domain, exhibit increased p53 activity and suffer from aplastic anemia and pulmonary fibrosis, hallmarks of syndromes caused by short telomeres. Indeed, p53Δ31/Δ31 mice had short telomeres and other phenotypic traits associated with the telomere disease dyskeratosis congenita and its severe variant the Hoyeraal-Hreidarsson syndrome. Heterozygous p53+/Δ31 mice were only mildly affected, but decreased levels of Mdm4, a negative regulator of p53, led to a dramatic aggravation of their symptoms. Importantly, several genes involved in telomere metabolism were downregulated in p53Δ31/Δ31 cells, including Dyskerin, Rtel1, and Tinf2, which are mutated in dyskeratosis congenita, and Terf1, which is implicated in aplastic anemia. Together, these data reveal that a truncating mutation can activate p53 and that p53 plays a major role in the regulation of telomere metabolism.

Structural Basis of Competitive Recognition of p53 and MDM2 by HAUSP/USP7: Implications for the Regulation of the p53-MDM2 Pathway.

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2006-01-01

Full Text Available Herpesvirus-associated ubiquitin-specific protease (HAUSP, also known as USP7, a deubiquitylating enzyme of the ubiquitin-specific processing protease family, specifically deubiquitylates both p53 and MDM2, hence playing an important yet enigmatic role in the p53-MDM2 pathway. Here we demonstrate that both p53 and MDM2 specifically recognize the N-terminal tumor necrosis factor-receptor associated factor (TRAF-like domain of HAUSP in a mutually exclusive manner. HAUSP preferentially forms a stable HAUSP-MDM2 complex even in the presence of excess p53. The HAUSP-binding elements were mapped to a peptide fragment in the carboxy-terminus of p53 and to a short-peptide region preceding the acidic domain of MDM2. The crystal structures of the HAUSP TRAF-like domain in complex with p53 and MDM2 peptides, determined at 2.3-A and 1.7-A resolutions, respectively, reveal that the MDM2 peptide recognizes the same surface groove in HAUSP as that recognized by p53 but mediates more extensive interactions. Structural comparison led to the identification of a consensus peptide-recognition sequence by HAUSP. These results, together with the structure of a combined substrate-binding-and-deubiquitylation domain of HAUSP, provide important insights into regulation of the p53-MDM2 pathway by HAUSP.

P53 expression in prostatic cancer: an immunohistochemical study

International Nuclear Information System (INIS)

Al-Nuaimy, W.M.; Al-Allaf, L.I.; Alnaimi, H.A.

2011-01-01

Prostate cancer is the most common malignancy in men and second leading cause of cancer death in the Western world. P53 alterations are the most frequent genetic changes in human cancers. Mutation of the p53 gene has been implicated in the development of >50% of all human cancer. The current study aims at evaluating the immuno-histochemical expression of p53 protein in patients with cancer of prostate, as prognostic parameter in correlation with other parameters including PSA receptors, and to correlate the results with those of other studies. (authors).

The critical role of catalase in prooxidant and antioxidant function of p53

Science.gov (United States)

Kang, M Y; Kim, H-B; Piao, C; Lee, K H; Hyun, J W; Chang, I-Y; You, H J

2013-01-01

The tumor suppressor p53 is an important regulator of intracellular reactive oxygen species (ROS) levels, although downstream mediators of p53 remain to be elucidated. Here, we show that p53 and its downstream targets, p53-inducible ribonucleotide reductase (p53R2) and p53-inducible gene 3 (PIG3), physically and functionally interact with catalase for efficient regulation of intracellular ROS, depending on stress intensity. Under physiological conditions, the antioxidant functions of p53 are mediated by p53R2, which maintains increased catalase activity and thereby protects against endogenous ROS. After genotoxic stress, high levels of p53 and PIG3 cooperate to inhibit catalase activity, leading to a shift in the oxidant/antioxidant balance toward an oxidative status, which could augment apoptotic cell death. These results highlight the essential role of catalase in p53-mediated ROS regulation and suggest that the p53/p53R2–catalase and p53/PIG3–catalase pathways are critically involved in intracellular ROS regulation under physiological conditions and during the response to DNA damage, respectively. PMID:22918438

Mathematical Modeling of E6-p53 interactions in Cervical Cancer

Science.gov (United States)

Khattak, Faryal; Haseeb, Muhammad; Fazal, Sahar; Bhatti, A I; Ullah, Mukhtar

2017-04-01

Background: Cervical cancer is the third most common cancer in women throughout the world. The human papillomavirus (HPV) E6 viral protein plays an essential role in proteasomal degradation of the cancer suppressant protein p53. As a result, p53 negative regulation and apoptosis relevant activities are abrogated, facilitating development of cervical cancer. Methods: A mathematical model of E6-p53 interactions was developed using mathematical laws. In-silico simulations were carried out on CellDesigner and as a test case the small molecule drug RITA was considered for its ability to rescue the functions of tumor suppressor p53 by inhibiting E6 mediated proteasomal degradation. Results: Using a computational model we scrutinized how p53 responds to RITA, and chemical reactions of this small molecule drug were incorporated to perceive the full effects. The evolved strategy allowed the p53 response and rescue of its tumor suppressor function to be delineated, RITA being found to block p53 interactions with E6 associated proteins. Conclusion: We could develop a model of E6-p53 interactions with incorporation of actions of the small molecule drug RITA. Suppression of E6 associated proteins by RITA induces accumulation of tumor suppressant p53. Using CellDesigner to encode the model ensured that it can be easily modified and extended as more data become available. This strategy should play an effective role in the development of therapies against cancer. Creative Commons Attribution License

p53 Dependent Centrosome Clustering Prevents Multipolar Mitosis in Tetraploid Cells

Science.gov (United States)

Yi, Qiyi; Zhao, Xiaoyu; Huang, Yun; Ma, Tieliang; Zhang, Yingyin; Hou, Heli; Cooke, Howard J.; Yang, Da-Qing; Wu, Mian; Shi, Qinghua

2011-01-01

Background p53 abnormality and aneuploidy often coexist in human tumors, and tetraploidy is considered as an intermediate between normal diploidy and aneuploidy. The purpose of this study was to investigate whether and how p53 influences the transformation from tetraploidy to aneuploidy. Principal Findings Live cell imaging was performed to determine the fates and mitotic behaviors of several human and mouse tetraploid cells with different p53 status, and centrosome and spindle immunostaining was used to investigate centrosome behaviors. We found that p53 dominant-negative mutation, point mutation, or knockout led to a 2∼ 33-fold increase of multipolar mitosis in N/TERT1, 3T3 and mouse embryonic fibroblasts (MEFs), while mitotic entry and cell death were not significantly affected. In p53-/- tetraploid MEFs, the ability of centrosome clustering was compromised, while centrosome inactivation was not affected. Suppression of RhoA/ROCK activity by specific inhibitors in p53-/- tetraploid MEFs enhanced centrosome clustering, decreased multipolar mitosis from 38% to 20% and 16% for RhoA and ROCK, respectively, while expression of constitutively active RhoA in p53+/+ tetraploid 3T3 cells increased the frequency of multipolar mitosis from 15% to 35%. Conclusions p53 could not prevent tetraploid cells entering mitosis or induce tetraploid cell death. However, p53 abnormality impaired centrosome clustering and lead to multipolar mitosis in tetraploid cells by modulating the RhoA/ROCK signaling pathway. PMID:22076149