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1.
Food Chem ; 224: 219-223, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28159259

RESUMO

Resveratrol is a stilbene, which is one of a group of polyphenols in many plant foods. Interest in this substance lies in its potential health benefits. This study aimed to compare two different methods, chromatographic and constant-wavelength synchronous spectrofluorimetry, an alternative technique to determine the amount of resveratrol dietary supplements, as a model for more complex foods. High-performance liquid chromatography-photodyode array detector-mass spectrometry/mass spectrometry was used to confirm the results. The results obtained showed that both methods were valid for the determination of resveratrol in dietary supplements. HPLC with fluorescence and variable wavelength detectors offered better linearity and sensitivity, and would be more suitable for the determination of several stilbenes in complex samples. On the other hand, constant-wavelength synchronous spectrofluorimetry is a sensitive, rapid and inexpensive method that could be used for quick and precise determination when samples are expected to contain only one stilbene.


Assuntos
Suplementos Nutricionais/análise , Estilbenos/análise , Verduras/química , Cromatografia Líquida de Alta Pressão/métodos , Resveratrol , Espectrometria de Massas em Tandem/métodos
2.
Mol Psychiatry ; 21(12): 1690-1695, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27001614

RESUMO

A current focus in psychiatric genetics is detection of multiple common risk alleles through very large genome-wide association study analyses. Yet families do exist, albeit rare, that have multiple affected members who are presumed to have a similar inherited cause to their illnesses. We hypothesized that within some of these families there may be rare highly penetrant mutations that segregate with illness. In this exploratory study, the genomes of 90 individuals across nine families were sequenced. Each family included a minimum of three available relatives affected with a psychotic illness and three available unaffected relatives. Twenty-six variants were identified that are private to a family, alter protein sequence, and are transmitted to all sequenced affected individuals within the family. In one family, seven siblings with schizophrenia spectrum disorders each carry a novel private missense variant within the SHANK2 gene. This variant lies within the consensus SH3 protein-binding motif by which SHANK2 may interact with post-synaptic glutamate receptors. In another family, four affected siblings and their unaffected mother each carry a novel private missense variant in the SMARCA1 gene on the X chromosome. Both variants represent candidates that may be causal for psychotic disorders when considered in the context of their transmission pattern and known gene and disease biology.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas do Tecido Nervoso/genética , Transtornos Psicóticos/genética , Fatores de Transcrição/genética , Adulto , Alelos , Linhagem Celular , Proteínas de Ligação a DNA/metabolismo , Exoma , Família/psicologia , Feminino , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Proteínas do Tecido Nervoso/metabolismo , Linhagem , Esquizofrenia/genética , Irmãos , Fatores de Transcrição/metabolismo
3.
Aliment Pharmacol Ther ; 35(8): 941-7, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22372560

RESUMO

BACKGROUND: In some cases, Helicobacter pylori infection persists even after three eradication treatments. AIM: To evaluate the efficacy of an empirical fourth-line rescue regimen with rifabutin in patients with three eradication failures. DESIGN: Multicentre, prospective study. PATIENTS: In whom the following three treatments had consecutively failed: first (PPI + clarithromycin + amoxicillin); second (PPI + bismuth + tetracycline + metronidazole); third (PPI + amoxicillin + levofloxacin). INTERVENTION: A fourth regimen with rifabutin (150 mg b.d.), amoxicillin (1 g b.d.) and a PPI (standard dose b.d.) was prescribed for 10 days. OUTCOME: Eradication was confirmed by (13) C-urea breath test 4-8 weeks after therapy. Compliance and tolerance: Compliance was determined through questioning and recovery of empty medication envelopes. Adverse effects were evaluated using a questionnaire. RESULTS: One-hundred patients (mean age 50 years, 39% men, 31% peptic ulcer/69% functional dyspepsia) were included. Eight patients did not take the medication correctly (in six cases due to adverse effects). Per-protocol and intention-to-treat eradication rates were 52% (95% CI = 41-63%) and 50% (40-60%). Adverse effects were reported in 30 (30%) patients: nausea/vomiting (13 patients), asthenia/anorexia (8), abdominal pain (7), diarrhoea (5), fever (4), metallic taste (4), myalgia (4), hypertransaminasemia (2), leucopenia (<1,500 neutrophils) (2), thrombopenia (<150,000 platelets) (2), headache (1) and aphthous stomatitis (1). Myelotoxicity resolved spontaneously in all cases. CONCLUSIONS: Even after three previous H. pylori eradication failures, an empirical fourth-line rescue treatment with rifabutin may be effective in approximately 50% of the cases. Therefore, rifabutin-based rescue therapy constitutes a valid strategy after multiple previous eradication failures with key antibiotics, such as clarithromycin, metronidazole, tetracycline and levofloxacin.


Assuntos
Antibacterianos/uso terapêutico , Dispepsia/tratamento farmacológico , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori/isolamento & purificação , Úlcera Péptica/tratamento farmacológico , Rifabutina/uso terapêutico , Adulto , Antibacterianos/efeitos adversos , Quimioterapia Combinada , Dispepsia/microbiologia , Feminino , Seguimentos , Infecções por Helicobacter/microbiologia , Humanos , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Úlcera Péptica/microbiologia , Estudos Prospectivos , Rifabutina/efeitos adversos , Inquéritos e Questionários , Falha de Tratamento , Resultado do Tratamento
6.
Nefrologia ; 31(5): 614-6, 2011.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-21959736
11.
Rev Esp Enferm Dig ; 101(6): 395-8, 399-402, 2009 Jun.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-19630462

RESUMO

BACKGROUND: Triple therapy including a proton pump inhibitor, clarithromycin, and amoxicillin (PPI-CA) is the first-choice treatment used for H. pylori eradication. The efficacy of this treatment is declining of late, and alternative therapies are currently under evaluation. OBJECTIVES: To evaluate the efficacy, safety and compliance of a triple therapy with a PPI, amoxicillin and levofloxacin (PPI-LA)--replacing clarithromycin--for the eradication of H. pylori. METHODS: The study included 135 patients (65% women), mean age 53 years, with dyspeptic symptoms and H. pylori infection proven by a positive urease rapid test, histological analysis, or C13-urea breath test. DIAGNOSIS: non-investigated dyspepsia 48.9%, functional dyspepsia 36.3%, and ulcerative dyspepsia 14.8%. Treatment was indicated with a proton pump inhibitor at usual doses, amoxicillin 1 g, and levofloxacin 500 mg, administered jointly during breakfast and dinner for 10 days. We studied the performance of this triple therapy and its effects using a questionnaire, and effectiveness by the negativity of the C13-urea breath test after 6-8 weeks after treatment discontinuation. Per protocol, we compared the effectiveness of PPI-LA with a control group of 270 patients treated with PPI-CA for 10 days. RESULTS: 130 patients (96.2%) could complete the treatment and follow-up protocol. Effectiveness (intention to treat) was 71.8% (97/135) and 74.6% (per protocol) (97/130). Sixteen patients (11.8%) had well-tolerated adverse effects, except for 5 subjects (3.7%) who dropped out. PPI-CA was effective (per protocol) in 204 patients out of 270 (75.5%) in the control group. CONCLUSIONS: Triple therapy with a PPI, amoxicillin and levofloxacin for 10 days is a well-tolerated treatment that is easy to comply with; however it has low efficiency - less than 80% - and is not recommended as a first-choice treatment for H. pylori eradication. Similar results were obtained with the classic triple therapy using a PPI, clarithromycin and amoxicillin.


Assuntos
Amoxicilina/uso terapêutico , Antibacterianos/uso terapêutico , Levofloxacino , Ofloxacino/uso terapêutico , Inibidores da Bomba de Prótons/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
12.
Rev. esp. enferm. dig ; 101(6): 395-402, jun. 2009. tab
Artigo em Espanhol | IBECS | ID: ibc-74412

RESUMO

Introducción: la triple terapia con un inhibidor de la bomba de protones, claritromicina y amoxicilina (IBP-CA) es el tratamiento de primera elección más utilizado en la erradicación de H. pylori. La eficacia de este tratamiento está disminuyendo en los últimos años y se están valorando otras alternativas terapéuticas. Objetivos:valorar la eficacia, cumplimiento y seguridad de una triple terapia con un IBP, amoxicilina y levofloxacino, sustituyendo a la claritromicina, en la erradicación de H. pylori. Métodos: periodo de estudio: 2007-2008. Se incluyen 135 pacientes (65% mujeres), edad media de 53 años, con síntomas dispépticos e infección por H. pylori, constatada por positividad del test rápido de la ureasa, histología o prueba del aliento con urea-C13. Diagnósticos: dispepsia no investigada: 48,9%, dispepsia funcional: 36,3% y dispepsia ulcerosa: 14,8%. Se indica tratamiento con un inhibidor de la bomba de protones, a dosis habitual, amoxicilina 1 g y levofloxacino 500 mg (IBP-LA), administrados de forma conjunta en desayuno y cena, durante 10 días. Se valora el cumplimiento de la triple terapia y sus efectos adversos mediante interrogatorio y su eficacia mediante la negatividad de la prueba del aliento con urea-C13 practicada a las 6-8 semanas del término del tratamiento. Se compara la eficacia, por protocolo, del tratamiento con IBP-LA con la observada en un grupo control de 270 pacientes tratados con IBP-CA durante 10 días en los años 2006-2007. Resultados: 130/135 pacientes (96,2) del grupo de estudio completaron el tratamiento y el protocolo del seguimiento. La eficacia por intención de tratar fue del 71,8% (97/135) y por protocolo del 74,6% (97/130). Dieciséis pacientes (11,8%) presentaron efectos adversos bien tolerados, excepto en 5 pacientes (3.7%) que motivan el abandono del tratamiento. El tratamiento con IBP-CA resultó eficaz, por protocolo, en 204/270 (75,5%) pacientes del grupo control...(AU)


Background: triple therapy including a proton pump inhibitor, clarithromycin, and amoxicillin (PPI-CA) is the first-choice treatment used for H. pylori eradication. The efficacy of this treatment is declining of late, and alternative therapies are currently under evaluation. Objectives: to evaluate the efficacy, safety and compliance of a triple therapy with a PPI, amoxicillin and levofloxacin (PPI-LA) - replacing clarithromycin - for the eradication of H. pylori. Methods: the study included 135 patients (65% women), mean age 53 years, with dyspeptic symptoms and H. pylori infection proven by a positive urease rapid test, histological analysis, or C13-urea breath test. Diagnosis: non-investigated dyspepsia 48.9%, functional dyspepsia 36.3%, and ulcerative dyspepsia 14.8%. Treatment was indicated with a proton pump inhibitor at usual doses, amoxicillin 1 g, and levofloxacin 500 mg, administered jointly during breakfast and dinner for 10 days. We studied the performance of this triple therapy and its effects using a questionnaire, and effectiveness by the negativity of the C13-urea breath test after 6-8 weeks after treatment discontinuation. Per protocol, we compared the effectiveness of PPI-LA with a control group of 270 patients treated with PPI-CA for 10 days. Results: 130 patients (96.2%) could complete the treatment and follow-up protocol. Effectiveness (intention to treat) was 71.8% (97/135) and 74.6% (per protocol) (97/130). Sixteen patients (11.8%) had well-tolerated adverse effects, except for 5 subjects (3.7%) who dropped out. PPI-CA was effective (per protocol) in 204 patients out of 270 (75.5%) in the control group...(AU)


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Amoxicilina/uso terapêutico , Antibacterianos/uso terapêutico , Ofloxacino/uso terapêutico , Inibidores da Bomba de Prótons/uso terapêutico , Estudos Prospectivos , Helicobacter pylori/isolamento & purificação , Infecções por Helicobacter/etiologia , Ofloxacino/efeitos adversos , Amoxicilina/efeitos adversos
13.
Gastroenterol Hepatol ; 29(1): 11-4, 2006 Jan.
Artigo em Espanhol | MEDLINE | ID: mdl-16393624

RESUMO

INTRODUCTION: Peptic ulcer disease, with or without complications, is more common in patients with liver cirrhosis than in the general population. Factors associated with portal hypertension are involved in its pathogenesis. The prevalence of Helicobacter pylori infection in patients with liver cirrhosis and the general population is similar. The aim of the present study was to determine the influence of nonsteroidal antiinflammatory drugs (NSAIDs) in the etiology of bleeding peptic ulcer disease in patients with liver cirrhosis. PATIENTS AND METHODS: We studied 35 patients with liver cirrhosis and gastrointestinal bleeding due to gastroduodenal ulcers or erosions (group A), 125 noncirrhotic patients with gastrointestinal bleeding due to gastroduodenal ulcers or erosions (group B), and 70 patients with liver cirrhosis who were admitted to hospital without gastrointestinal bleeding (group C). All patients were questioned about NSAID consumption, including aspirin, during the week prior to hospital admission. RESULTS: NSAID consumption was reported by 15 patients (42.8%) in group A, 102 patients (58.2%) in group B, and 6 patients (8.5%) in group C. Statistically significant differences were obtained when the results for group A were compared with those for group C. CONCLUSIONS: NSAID consumption in patients with liver cirrhosis without gastrointestinal bleeding was low (8.5%) and was much lower than that observed in patients with cirrhosis admitted to hospital for bleeding due to gastroduodenal ulcers or erosions (42.8%). As occurs in the general population, NSAIDs play a significant role in the pathogenesis of bleeding due to peptic ulcer disease in patients with liver cirrhosis and portal hypertension.


Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Hemorragia Gastrointestinal/etiologia , Cirrose Hepática/complicações , Úlcera Péptica/complicações , Idoso , Uso de Medicamentos , Feminino , Hemorragia Gastrointestinal/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade
14.
Gastroenterol. hepatol. (Ed. impr.) ; 29(1): 11-14, ene. 2006. tab
Artigo em Es | IBECS | ID: ibc-042940

RESUMO

Introducción: La enfermedad péptica gastroduodenal, con o sin complicaciones, es más frecuente en los pacientes con cirrosis hepática que en la población general y en su patogenia influirían factores dependientes de la hipertensión portal. La prevalencia de la infección por Helicobacter pylori en la población con cirrosis hepática es similar a la existente en la población general. Se objetiva conocer la influencia de los antiinflamatorios no esteroideos (AINE) en la etiología de la patología péptica gastroduodenal con hemorragia digestiva de los pacientes con cirrosis hepática. Pacientes y métodos: Se incluyó a 35 pacientes con cirrosis hepática con hemorragia digestiva por úlceras o erosiones gastroduodenales (grupo A), 125 pacientes no cirróticos, con hemorragia digestiva por úlceras o erosiones gastroduodenales (grupo B) y 70 pacientes con cirrosis hepática que ingresan sin hemorragia digestiva (grupo C). En todos los pacientes, mediante encuesta dirigida, se investiga el consumo de AINE, incluido ácido acetilsalicílico (AAS), en la semana previa al ingreso hospitalario. Resultados: Referían consumo de AINE 15 pacientes (42,8%) del grupo A, 102 pacientes (58,2%) del grupo B y 6 pacientes (8,5%) del grupo C. Se obtuvieron diferencias significativas al comparar los resultados del grupo A con el grupo C. Conclusiones: El consumo de AINE en los pacientes con cirrosis hepática sin hemorragia digestiva es bajo (8,5%), muy inferior al observado en los pacientes con cirrosis que ingresan con hemorragia por úlceras o erosiones gastroduodenales (42,8%). Se puede considerar que los AINE, como sucede en la población general, desempeñarían un importante papel en la patogenia de la hemorragia digestiva por patología péptica en la población con cirrosis hepática e hipertensión portal


Introduction: Peptic ulcer disease, with or without complications, is more common in patients with liver cirrhosis than in the general population. Factors associated with portal hypertension are involved in its pathogenesis. The prevalence of Helicobacter pylori infection in patients with liver cirrhosis and the general population is similar. The aim of the present study was to determine the influence of nonsteroidal antiinflammatory drugs (NSAIDs) in the etiology of bleeding peptic ulcer disease in patients with liver cirrhosis. Patients and methods: We studied 35 patients with liver cirrhosis and gastrointestinal bleeding due to gastroduodenal ulcers or erosions (group A), 125 noncirrhotic patients with gastrointestinal bleeding due to gastroduodenal ulcers or erosions (group B), and 70 patients with liver cirrhosis who were admitted to hospital without gastrointestinal bleeding (group C). All patients were questioned about NSAID consumption, including aspirin, during the week prior to hospital admission. Results: NSAID consumption was reported by 15 patients (42.8%) in group A, 102 patients (58.2%) in group B, and 6 patients (8.5%) in group C. Statistically significant differences were obtained when the results for group A were compared with those for group C. Conclusions: NSAID consumption in patients with liver cirrhosis without gastrointestinal bleeding was low (8.5%) and was much lower than that observed in patients with cirrhosis admitted to hospital for bleeding due to gastroduodenal ulcers or erosions (42.8%). As occurs in the general population, NSAIDs play a significant role in the pathogenesis of bleeding due to peptic ulcer disease in patients with liver cirrhosis and portal hypertension


Assuntos
Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Humanos , Anti-Inflamatórios não Esteroides/efeitos adversos , Hemorragia Gastrointestinal/etiologia , Cirrose Hepática/complicações , Úlcera Péptica/complicações , Uso de Medicamentos , Hemorragia Gastrointestinal/epidemiologia
15.
Gastroenterol. hepatol. (Ed. impr.) ; 29(1): 11-14, ene. 2006. tab
Artigo em Es | IBECS | ID: ibc-042958

RESUMO

Introducción: La enfermedad péptica gastroduodenal, con o sin complicaciones, es más frecuente en los pacientes con cirrosis hepática que en la población general y en su patogenia influirían factores dependientes de la hipertensión portal. La prevalencia de la infección por Helicobacter pylori en la población con cirrosis hepática es similar a la existente en la población general. Se objetiva conocer la influencia de los antiinflamatorios no esteroideos (AINE) en la etiología de la patología péptica gastroduodenal con hemorragia digestiva de los pacientes con cirrosis hepática. Pacientes y métodos: Se incluyó a 35 pacientes con cirrosis hepática con hemorragia digestiva por úlceras o erosiones gastroduodenales (grupo A), 125 pacientes no cirróticos, con hemorragia digestiva por úlceras o erosiones gastroduodenales (grupo B) y 70 pacientes con cirrosis hepática que ingresan sin hemorragia digestiva (grupo C). En todos los pacientes, mediante encuesta dirigida, se investiga el consumo de AINE, incluido ácido acetilsalicílico (AAS), en la semana previa al ingreso hospitalario. Resultados: Referían consumo de AINE 15 pacientes (42,8%) del grupo A, 102 pacientes (58,2%) del grupo B y 6 pacientes (8,5%) del grupo C. Se obtuvieron diferencias significativas al comparar los resultados del grupo A con el grupo C. Conclusiones: El consumo de AINE en los pacientes con cirrosis hepática sin hemorragia digestiva es bajo (8,5%), muy inferior al observado en los pacientes con cirrosis que ingresan con hemorragia por úlceras o erosiones gastroduodenales (42,8%). Se puede considerar que los AINE, como sucede en la población general, desempeñarían un importante papel en la patogenia de la hemorragia digestiva por patología péptica en la población con cirrosis hepática e hipertensión portal


Introduction: Peptic ulcer disease, with or without complications, is more common in patients with liver cirrhosis than in the general population. Factors associated with portal hypertension are involved in its pathogenesis. The prevalence of Helicobacter pylori infection in patients with liver cirrhosis and the general population is similar. The aim of the present study was to determine the influence of nonsteroidal antiinflammatory drugs (NSAIDs) in the etiology of bleeding peptic ulcer disease in patients with liver cirrhosis. Patients and methods: We studied 35 patients with liver cirrhosis and gastrointestinal bleeding due to gastroduodenal ulcers or erosions (group A), 125 noncirrhotic patients with gastrointestinal bleeding due to gastroduodenal ulcers or erosions (group B), and 70 patients with liver cirrhosis who were admitted to hospital without gastrointestinal bleeding (group C). All patients were questioned about NSAID consumption, including aspirin, during the week prior to hospital admission. Results: NSAID consumption was reported by 15 patients (42.8%) in group A, 102 patients (58.2%) in group B, and 6 patients (8.5%) in group C. Statistically significant differences were obtained when the results for group A were compared with those for group C. Conclusions: NSAID consumption in patients with liver cirrhosis without gastrointestinal bleeding was low (8.5%) and was much lower than that observed in patients with cirrhosis admitted to hospital for bleeding due to gastroduodenal ulcers or erosions (42.8%). As occurs in the general population, NSAIDs play a significant role in the pathogenesis of bleeding due to peptic ulcer disease in patients with liver cirrhosis and portal hypertension


Assuntos
Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Humanos , Anti-Inflamatórios não Esteroides/efeitos adversos , Hemorragia Gastrointestinal/etiologia , Cirrose Hepática/complicações , Úlcera Péptica/complicações , Uso de Medicamentos , Hemorragia Gastrointestinal/epidemiologia
16.
Enzyme Microb Technol ; 28(7-8): 642-652, 2001 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-11339948

RESUMO

Blends of cardosins A and B, enzymes present in aqueous extracts of the flowers of the thistle (Cynara cardunculus L.), have for long been used as rennets by the cheesemaking industry in the Iberian Peninsula. These dimeric proteases are present in the stigmae and stylets of said flowers, and are thought to play a role in sexual reproduction of the plant. In the present research effort, production of cardosin derivatives (starting from a crude extract), encompassing full stabilization of their dimeric structure, has been attempted via covalent, multi-subunit immobilization onto highly activated agarose-glutaraldehyde supports. Boiling such enzyme derivatives in the presence of sodium dodecyl sulfate and beta-mercaptoethanol did not lead to leaching of enzyme, thus proving the effectiveness of the attachment procedure. Furthermore, derivatives prepared under optimal conditions presented ca. half the specific activity of the enzyme in soluble form, and were successfully employed at lab-scale trials to perform (selective) hydrolysis of alpha-lactalbumin, one of the major proteins in bovine whey.

17.
Exp Hematol ; 28(12): 1432-40, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11146165

RESUMO

During megakaryocyte differentiation, the immature megakaryocyte increases its ploidy to a 2(x) DNA content by a process called endomitosis. This leads to the formation of a giant cell, the mature megakaryocyte, which gives rise to platelets. We investigated the role of human-nuc (h-nuc), a gene involved in septum formation in karyokynesis in yeast, during megakaryocytic polyploidization. Nocodazole and 12-O-tetradecanoylphorbol-13-acetate (TPA) were used to induce megakaryocytic differentiation in K562 cell line. The ploidy distribution and CD41 expression of treated K562 cells were evaluated by flow cytometry. Using quantitative reverse transcriptase polymerase chain reaction (RT-PCR), we analyzed the h-nuc mRNA expression on treated K562 cells. Mature megakaryocyte-like polyploid cells were detected at day 5-7 of treatment with nocodazole. TPA also had a similar effect on K562 cells, but it was much weaker than that of nocodazole. The analysis of ploidy of nocodazole-treated K562 cells showed that nocodazole preferentially induced polyploidization of K562 cell line with a pronounced increase of the cells 8N at day 7 of culture. Expression of CD41, a differentiation-related phenotype, was significantly induced by TPA after 7 days of treatment, showing that functional maturation was mainly induced by TPA. In contrast, there was no significant increase in CD41 expression in nocodazole-treated K562 cells, suggesting that polyploidization and functional maturation are separately regulated during megakaryocytopoiesis. RT-PCR analysis indicated that h-nuc mRNA increased after 72 hours in the presence of nocodazole, preceding the induction of polyploidization. Our data indicate that h-nuc might play a role in polyploidization during megakaryocytic differentiation via inhibition of septum formation.


Assuntos
Diferenciação Celular , Megacariócitos/química , Megacariócitos/patologia , Poliploidia , Apoptose , DNA/análise , Citometria de Fluxo , Expressão Gênica , Humanos , Células K562 , Mitose , Nocodazol/farmacologia , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/análise , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/genética , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Acetato de Tetradecanoilforbol/farmacologia
18.
Oncogene ; 18(32): 4577-85, 1999 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-10467402

RESUMO

P27, an inhibitor of cyclin-dependent kinases, plays an important role in the control of cell adhesion and contact inhibition-dependent cell cycle regulation. Hepatocytes, maintained in primary culture, offer a model of synchronized primary epithelial cells which retain a differentiated profile while stimulated to proliferate. We therefore investigated the pattern of endogenous p27 expression in cyclin rat hepatocytes isolated by collagenase perfusion followed by mitogenic stimulation. P27 was expressed in whole normal liver and freshly isolated hepatocytes. We then observed a sharp decrease in p27 levels, concomitant with the progression in early-mid G1, followed by reaccumulation in late G1 and the G1/S transition. Immunochemistry and BrdU labelling demonstrated nuclear localization of p27 and its expression in cells engaged in both G1 and S phase. P27 was detected in late G1 in complexes containing cyclins D1, E and A. Cyclin E- and A-associated kinase activities, however, were detected at the G1/S transition and depletion experiments confirmed that most active complexes were free of p27. Phosphorylated forms of p27 were detected in unstimulated and stimulated hepatocytes in both early-mid G1 and G1/S. Finally, two-dimensional gel electrophoresis showed evidence for several forms of p27 with a distinct profile of distribution in quiescent and stimulated hepatocytes. Collectively, our data offer a model in which p27 shows a biphasic profile of accumulation, with the early decrease possibly involved in the progression through early and mid G1. In contrast with most cell types tested so far, the late G1 accumulation did not impair formation of active cyclin E- and A associated kinases, and thus G1/S transition.


Assuntos
Proteínas de Ciclo Celular , Quinases Ciclina-Dependentes/antagonistas & inibidores , Inibidores Enzimáticos/metabolismo , Fígado/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Supressoras de Tumor , Animais , Núcleo Celular/metabolismo , Células Cultivadas , Ciclina A/metabolismo , Ciclina E/metabolismo , Inibidor de Quinase Dependente de Ciclina p27 , Quinases Ciclina-Dependentes/metabolismo , Ciclinas/metabolismo , Fase G1 , Fígado/citologia , Masculino , Proteínas Associadas aos Microtúbulos/biossíntese , Fosforilação , Ratos , Ratos Wistar , Fase S
19.
Rev Med Chil ; 126(9): 1035-42, 1998 Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-9922505

RESUMO

BACKGROUND: The impact of hepatitis C virus infection in Chile has not been well established. AIM: To assess hepatitis C virus infection in normal Chileans and in patients with liver disease. SUBJECTS AND METHODS: Antibodies against hepatitis C virus were investigated in 21,000 blood donors, 133 patients with non alcoholic chronic liver disease and in 50 patients with hepatocarcinoma. Viral RNA was studied by polymerase chain reaction in all positive blood donors, in 51 patients with chronic liver disease and in all patients with hepatocarcinoma. Hepatitis C virus genotype was established using restriction fragment length polymorphism in 118 RNA positive samples. RESULTS: In blood donors, a 0.3% prevalence of positive antibodies was found. The figure for chronic liver disease was 53% and for hepatocarcinoma, 48%. Viral RNA was detected in 100% of patients with chronic liver disease and hepatocarcinoma and in 68% of blood donors with positive antibodies. Genotype 1b was identified in all infected patients with hepatocarcinoma, in 86% of patients with chronic liver disease and in 46% of blood donors. CONCLUSIONS: Hepatitis C virus infection is an important etiologic agent for chronic liver disease in Chile. The predominance of genotype 1b among patients with the most severe form of liver disease is in agreement with observations made abroad.


Assuntos
Doadores de Sangue , Carcinoma Hepatocelular/virologia , Hepacivirus/genética , Hepacivirus/isolamento & purificação , Hepatite C Crônica/complicações , Hepatopatias/virologia , Neoplasias Hepáticas/virologia , Adulto , Carcinoma Hepatocelular/epidemiologia , Chile , Doença Crônica , Feminino , Genótipo , Hepatite C Crônica/epidemiologia , Humanos , Hepatopatias/epidemiologia , Neoplasias Hepáticas/epidemiologia , Masculino , Prevalência
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