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1.
Br J Cancer ; 112(5): 851-6, 2015 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-25668003

RESUMO

BACKGROUND: Patients with peritoneal metastases (PMs) originating from colorectal carcinoma (CRC) are curatively treated by cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) with mitomycin C (MMC). We aim to improve patient selection for HIPEC by predicting MMC sensitivity. METHODS: The MMC sensitivity was determined for 12 CRC cell lines and correlated to mRNA expression of 37 genes related to the Fanconi anaemia (FA)-BRCA pathway, ATM-ATR pathway and enzymatic activation of MMC. Functionality of the FA-BRCA pathway in cell lines was assessed using a chromosomal breakage assay and western blot for key protein FANCD2. Bloom syndrome protein (BLM) was further analysed by staining for the corresponding protein with immunohistochemistry (IHC) on both CRC cell lines (n=12) and patient material (n=20). RESULTS: High sensitivity correlated with a low BLM (P=0.01) and BRCA2 (P=0.02) at mRNA expression level. However, FA-BRCA pathway functionality demonstrated no correlation to MMC sensitivity. In cell lines, weak intensity staining of BLM by IHC correlated to high sensitivity (P=0.04) to MMC. Low BLM protein expression was significantly associated with an improved survival in patients after CRS and HIPEC (P=0.04). CONCLUSIONS: Low BLM levels are associated with high MMC sensitivity and an improved survival after HIPEC.


Assuntos
Antibióticos Antineoplásicos/farmacologia , Biomarcadores Tumorais/metabolismo , Neoplasias Colorretais/terapia , Hipertermia Induzida/métodos , Mitomicina/farmacologia , Neoplasias Peritoneais/secundário , Neoplasias Peritoneais/terapia , Antibióticos Antineoplásicos/uso terapêutico , Células CACO-2 , Linhagem Celular Tumoral , Neoplasias Colorretais/mortalidade , Proteína do Grupo de Complementação D2 da Anemia de Fanconi/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HCT116 , Células HT29 , Humanos , Mitomicina/uso terapêutico , Neoplasias Peritoneais/mortalidade , RecQ Helicases/metabolismo , Transdução de Sinais/efeitos dos fármacos , Análise de Sobrevida , Pesquisa Translacional Biomédica
2.
Arch Dis Child ; 95(12): 974-8, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20736400

RESUMO

BACKGROUND: Rectal measurement is considered a gold standard in many healthcare systems for body temperature measurement in children. Although this method has several disadvantages, an ideal alternative thermometer has not yet been introduced. However tympanic and infrared skin thermometers are potential alternatives. METHODS: A prospective cohort study was performed including 100 children between 0 and 18 years of age admitted to the general paediatric ward of Spaarne Hospital in The Netherlands between January and March 2009. The objectives of this study are to evaluate the accuracy of tympanic and two types of infrared skin thermometers (Beurer and Thermofocus) compared to rectal measurement and furthermore to evaluate the influence of different variables on temperature measurements. RESULTS: Compared to rectal measurement (37.56°C), the mean temperatures of the tympanic (37.29°C), Beurer (36.79°C) and Thermofocus (37.30°C) thermometers differed significantly (p<0.001). Mean and SD of differences between rectal temperature and temperature measured with these alternative devices varied significantly (p<0.001). Sensitivity, specificity, positive and negative predictive values for detecting rectal fever measured with the tympanic, Beurer and Thermofocus thermometers are unacceptable, especially for the Beurer thermometer. This difference in temperature between rectal and the alternative thermometers remained after stratification on gender, age, skin colour and otoscopic abnormalities. CONCLUSIONS: In this study the authors demonstrated that the tympanic, Beurer and Thermofocus thermometers cannot reliably predict rectal temperature. Therefore the authors do not advise replacement of rectal measurement as the gold standard for detecting fever in children by one of these devices. When rectal measurement is not used, the infrared skin thermometers appear to perform less well than tympanic measurements.


Assuntos
Temperatura Corporal/fisiologia , Termômetros , Membrana Timpânica/fisiologia , Adolescente , Fatores Etários , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Raios Infravermelhos , Estudos Prospectivos , Reto/fisiologia , Reprodutibilidade dos Testes , Fatores Sexuais , Pigmentação da Pele/fisiologia , Temperatura Cutânea/fisiologia
3.
Ned Tijdschr Geneeskd ; 152(8): 413-7, 2008 Feb 23.
Artigo em Holandês | MEDLINE | ID: mdl-18361186

RESUMO

During the summer of 2006 in the paediatric ward of the Spaarne Hospital in Hoofddorp, the Netherlands, a large number of children were admitted with a coxsackievirus type-B infection, one of the enteroviruses. A total of 27 children were diagnosed with this virus. Patient A, a one-month-old boy, was admitted with fever. The spinal fluid showed a high leukocyte count. He was treated with amoxicillin, ceftriaxon and acyclovir, and recovered rapidly. The spinal fluid culture was positive for coxsackievirus type B5. Patient B, a 3-year-old girl, presented with attacks of abdominal pain and groaning respiration. Infection parameters were mildly elevated. The chest X-ray was normal. She was admitted for observation and recovered spontaneously. Viral faeces culture revealed coxsackievirus type B4. Rapid recognition of an enterovirus infection is important to prevent unnecessary diagnostic and therapeutic interventions. PCR is a diagnostic technique of great importance.


Assuntos
Antivirais/uso terapêutico , Infecções por Coxsackievirus/epidemiologia , Surtos de Doenças/veterinária , Enterovirus Humano B/isolamento & purificação , Pré-Escolar , Infecções por Coxsackievirus/diagnóstico , Infecções por Coxsackievirus/tratamento farmacológico , Feminino , Humanos , Recém-Nascido , Masculino , Países Baixos , Reação em Cadeia da Polimerase/métodos , Resultado do Tratamento
4.
Ned Tijdschr Geneeskd ; 150(48): 2625-9, 2006 Dec 02.
Artigo em Holandês | MEDLINE | ID: mdl-17205936

RESUMO

Three healthy boys, 3.5, 5 and 1.5 years of age, were admitted to hospital with a severe bacterial skin infection, cerebellar ataxia, and pneumonia, respectively, one week after the onset of varicella. They recovered completely after treatment. Studies in Europe report complications from varicella in 2.5% of healthy children. Most of these are neurological complications and secondary bacterial infections of skin and soft tissue. Last year, a European consensus was published that recommended that all healthy children be vaccinated against chickenpox. In The Netherlands, routine varicella zoster virus (VZV) vaccination has not (yet) been implemented. We propose a new discussion on the possible inclusion of VZV vaccination in the national vaccination programme.


Assuntos
Ataxia Cerebelar/etiologia , Vacina contra Varicela , Varicela/complicações , Herpesvirus Humano 3/imunologia , Pleuropneumonia/etiologia , Dermatopatias Bacterianas/etiologia , Ataxia Cerebelar/epidemiologia , Varicela/prevenção & controle , Pré-Escolar , Política de Saúde , Humanos , Programas de Imunização , Lactente , Masculino , Países Baixos/epidemiologia , Pleuropneumonia/epidemiologia , Dermatopatias Bacterianas/epidemiologia
6.
Hum Mol Genet ; 9(18): 2665-74, 2000 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11063725

RESUMO

Fanconi anemia (FA) is a chromosomal instability syndrome associated with a strong predisposition to cancer, particularly acute myeloid leukemia and squamous cell carcinoma. At the cellular level, FA is characterized by spontaneous chromosomal breakage and a unique hypersensitivity to DNA cross-linking agents. Complementation analysis has indicated that at least seven distinct genes are involved in the pathogenesis of FA. Despite the identification of four of these genes (FANCA, FANCC, FANCF and FANCG), the nature of the 'FA pathway' has remained enigmatic, as the FA proteins lack sequence homologies or motifs that could point to a molecular function. To further define this pathway, we studied the subcellular localizations and mutual interactions of the FA proteins, including the recently identified FANCF protein, in human lymphoblasts. FANCF was found predominantly in the nucleus, where it complexes with FANCA, FANCC and FANCG. These interactions were detected in wild-type and FA-D lymphoblasts, but not in lymphoblasts of other FA complementation groups. This implies that each of the FA proteins, except FANCD, is required for these complexes to form. Similarly, we show that the interaction between FANCA and FANCC is restricted to wild-type and FA-D cells. Furthermore, we document the subcellular localization of FANCA and the FANCA/FANCG complex in all FA complementation groups. Our results, along with published data, culminate in a model in which a multi-protein FA complex serves a nuclear function to maintain genomic integrity.


Assuntos
Proteínas de Ciclo Celular , Núcleo Celular/química , Proteínas de Ligação a DNA/metabolismo , Anemia de Fanconi/metabolismo , Proteínas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Especificidade de Anticorpos , Western Blotting , Núcleo Celular/metabolismo , Citoplasma/química , Citoplasma/metabolismo , Proteínas de Ligação a DNA/genética , Anemia de Fanconi/genética , Proteína do Grupo de Complementação A da Anemia de Fanconi , Proteína do Grupo de Complementação C da Anemia de Fanconi , Proteína do Grupo de Complementação F da Anemia de Fanconi , Proteína do Grupo de Complementação G da Anemia de Fanconi , Proteínas de Grupos de Complementação da Anemia de Fanconi , Teste de Complementação Genética , Humanos , Linfócitos/metabolismo , Linfócitos/patologia , Substâncias Macromoleculares , Modelos Biológicos , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Testes de Precipitina , Ligação Proteica , Biossíntese de Proteínas , Proteínas/genética , Proteínas de Ligação a RNA/genética
7.
Eur J Hum Genet ; 8(11): 861-8, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11093276

RESUMO

FANCG was the third Faconi anaemia gene identified and proved to be identical to the previously cloned XRCC9 gene. We present the pathogenic mutations and sequence variants we have so far identified in a panel of FA-G patients. Mutation screening was performed by PCR, single strand conformational polymorphism analysis and protein truncation tests. Altogether 18 mutations have been determined in 20 families - 97% of all expected mutant alleles. All mutation types have been found, with the exception of large deletions, the large majority is predicted to lead to shortened proteins. One stop codon mutation, E105X, has been found in several German patients and this founder mutation accounts for 44% of the mutant FANCG alleles in German FA-G patients. Comparison of clinical phenotypes shows that patients homozygous for this mutation have an earlier onset of the haematological disorder than most other FA-G patients. The mouse Fancg sequence was established in order to evaluate missense mutations. A putative missense mutation, L71P, in a possible leucine zipper motif may affect FANCG binding of FANCA and seems to be associated with a milder clinical phenotype.


Assuntos
Proteínas de Ligação a DNA/genética , Anemia de Fanconi/genética , Mutação , Sequência de Aminoácidos , Sequência de Bases , DNA/química , DNA/genética , Análise Mutacional de DNA , Proteína do Grupo de Complementação G da Anemia de Fanconi , Humanos , Dados de Sequência Molecular , Polimorfismo Conformacional de Fita Simples , Homologia de Sequência de Aminoácidos
8.
Biometrics ; 56(3): 808-14, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10985220

RESUMO

This paper considers methods for estimating the relationship between a binary response Y and the genetic effects responsible for a second binary trait Z. The responses Y are observed only for target individuals, and the responses Z are observed only for the relatives of these targets. The analysis consists of two parts. The first part concerns the analysis of the family data Z and the second part estimates the relation between the genetic effects and Y. For the family data, a generalized linear mixed model with a logit link and Gaussian genetic (random) effects is used. Estimates of the variances of the genetic effects are obtained by using a pseudo-profile log-likelihood method. Estimation of the log likelihood involves averaging over n-dimensional normal distributions, which is done by importance sampling. The methods used in the second part are straightforward. The methods are applied to a data set containing chronic lung disease (CLDN) responses of newborns and asthma (AS), allergy (AL), chronic bronchitis (CB) and eczema (EC) responses observed for the relatives of these newborns. The clinical question is whether genetic effects of AS, AL, CB, and EC have an effect on the risk for CLDN. It can be concluded that for AS, AL, CB, and EC, the influence of genetic effects is significant. However, these genetic predispositions have no significant effect on CLDN.


Assuntos
Pneumopatias/genética , Modelos Genéticos , Modelos Estatísticos , Doenças Respiratórias/genética , Asma/epidemiologia , Asma/genética , Bronquite/epidemiologia , Bronquite/genética , Doença Crônica , Eczema/epidemiologia , Eczema/genética , Família , Feminino , Humanos , Hipersensibilidade/epidemiologia , Hipersensibilidade/genética , Recém-Nascido , Funções Verossimilhança , Pneumopatias/epidemiologia , Masculino , Distribuição Normal , Doenças Respiratórias/epidemiologia
9.
Am J Hum Genet ; 67(5): 1306-8, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11001585

RESUMO

Fanconi anemia (FA) is an autosomal recessive chromosomal instability syndrome with at least seven different complementation groups. Four FA genes (FANCA, FANCC, FANCF, and FANCG) have been identified, and two other FA genes (FANCD and FANCE) have been mapped. Here we report the identification, by complementation cloning, of the gene mutated in FA complementation group E (FANCE). FANCE has 10 exons and encodes a novel 536-amino acid protein with two potential nuclear localization signals.


Assuntos
Anemia de Fanconi/genética , Teste de Complementação Genética , Mutação/genética , Proteínas Nucleares/genética , Processamento Alternativo/genética , Sequência de Aminoácidos , Bangladesh/etnologia , Clonagem Molecular , DNA Complementar/genética , Éxons/genética , Proteína do Grupo de Complementação E da Anemia de Fanconi , Humanos , Íntrons/genética , Dados de Sequência Molecular , Sinais de Localização Nuclear , Proteínas Nucleares/química , Turquia/etnologia
10.
Hum Mutat ; 15(6): 578, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10862090

RESUMO

Homozygosity for a frameshift mutation at codon 1213 of FANCA gene was identified in a Turkish patient. Immunoprecipitation-western blot analysis showed the complete absence of the FANCA protein band. This novel mutation, a deletion of T at position 3639 in exon 37 (3639delT), is responsible for the disease and causes premature termination of translation 32 aa downstream. The deletion is (i) the T residue of 2 overlapping TGAGGC and CCTG hot spot motifs, (ii) flanked by several direct repeats, (iii) surrounded by the highly GC rich region that have frequently been identified at the site of human DNA deletions. The patient is the third living child of a first degree cousin marriage. The major abnormalities of the patient at the age of 6 months were growth retardation, microcephaly, hypoplastic right thumb, distal displacements of both thumbs and pelvic displacement of left kidney. Hematological presentation of the disease started before the age of 4 years.


Assuntos
Proteínas de Ciclo Celular , Proteínas de Ligação a DNA , Anemia de Fanconi/genética , Mutação da Fase de Leitura/genética , Proteínas Nucleares , Proteínas/genética , Criança , Pré-Escolar , Códon/genética , Anemia de Fanconi/patologia , Proteínas de Grupos de Complementação da Anemia de Fanconi , Feminino , Humanos , Lactente
12.
Br J Haematol ; 111(4): 1057-64, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11167740

RESUMO

Fanconi anaemia (FA) is an autosomal recessive disease strongly predisposing to bone marrow failure and acute myeloid leukaemia (AML). Four FA genes, corresponding to complementation groups A, C, F and G, have been cloned, but the molecular functions of the corresponding proteins are unknown. The high risk of AML in FA patients suggests that the 'FA pathway' helps to prevent AML in non-FA individuals. We examined 10 AML cell lines, as well as primary cells from 15 AML patients representing the French-American-British subclasses M1-M5a, for possible deficiencies in the 'FA pathway'. Cellular lysates were analysed for the presence of the FA proteins FANCA, FANCC, FANCF and FANCG, as well as the complexes reported to be formed between these proteins, using immunoprecipitation and Western blot analysis. Aberrant protein profiles were observed in five of the 10 cell lines and in 11 of the 15 primary AML samples. Aberrations, that included absence or reduced presence of FA proteins and/or their complexes, were noted in the subclasses M1-M4, but not in M5a (n = 3). Our results suggest that a significant proportion of general AML is characterized by a disturbance of the 'FA pathway' that may represent an early event in the development of this type of leukaemia.


Assuntos
Proteínas de Ciclo Celular , Proteínas de Ligação a DNA/análise , Anemia de Fanconi/metabolismo , Leucemia Mieloide/metabolismo , Proteínas Nucleares , Proteínas/análise , Proteínas de Ligação a RNA/análise , Doença Aguda , Adulto , Western Blotting/métodos , Células da Medula Óssea/metabolismo , Proteína do Grupo de Complementação A da Anemia de Fanconi , Proteína do Grupo de Complementação C da Anemia de Fanconi , Proteína do Grupo de Complementação F da Anemia de Fanconi , Proteína do Grupo de Complementação G da Anemia de Fanconi , Proteínas de Grupos de Complementação da Anemia de Fanconi , Feminino , Predisposição Genética para Doença , Humanos , Leucemia Mieloide Aguda/metabolismo , Leucemia Mielomonocítica Aguda/metabolismo , Leucemia Promielocítica Aguda/metabolismo , Masculino , Pessoa de Meia-Idade , Testes de Precipitina/métodos , Células Tumorais Cultivadas
13.
Am J Perinatol ; 17(7): 377-84, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-12141525

RESUMO

Individual lung development during the first year of life was studied in surfactant treated preterm infants with respiratory distress syndrome (RDS) and healthy controls, as well as in a group who subsequently developed chronic lung disease of the newborn (CLDN). Lung development was assessed from functional residual capacity (FRC) and compliance of the respiratory system (Crs). Twenty-one infants with RDS after preterm birth received surfactant treatment. Six of them developed CLDN. Eighteen preterm infants without RDS served as a control group. Lung function measurements were performed at term age and 4, 8, and 12 months afterwards. FRC was obtained by means of the closed-system helium dilution technique whereas static Crs was obtained by means of the weighted spirometer technique. At term age, FRC was lower in the CLDN group compared with uncomplicated RDS and controls (p < 0.05). No significant differences between groups were found in the development of FRC during the first year of life (p = 0.4). No differences were found in Crs during the first year of life in surfactant treated infants who recovered from uncomplicated RDS and the control group. However, lower values were found in the CLDN group (p < 0.05). We conclude that surfactant treated infants without CLDN have similar lung development during the first year of life as control preterm infants.


Assuntos
Capacidade Residual Funcional , Doenças do Prematuro/fisiopatologia , Surfactantes Pulmonares/uso terapêutico , Síndrome do Desconforto Respiratório do Recém-Nascido/fisiopatologia , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Doenças do Prematuro/terapia , Síndrome do Desconforto Respiratório do Recém-Nascido/terapia , Testes de Função Respiratória
14.
Proc Natl Acad Sci U S A ; 96(18): 10320-5, 1999 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-10468606

RESUMO

Fanconi anemia (FA) is a recessively inherited disease characterized at the cellular level by spontaneous chromosomal instability and specific hypersensitivity to cross-linking agents. FA is genetically heterogeneous, comprising at least eight complementation groups (A-H). We report that the protein encoded by the gene mutated in complementation group G (FANCG) localizes to the cytoplasm and nucleus of the cell and assembles in a molecular complex with the FANCA protein, both in vivo and in vitro. Endogenous FANCA/FANCG complex was detected in both non-FA cells and in FA cells from groups D and E. By contrast, no complex was detected in specific cell lines belonging to groups A and G, whereas reduced levels were found in cells from groups B, C, F, and H. Wild-type levels of FANCA/FANCG complex were restored upon correction of the cellular phenotype by transfection or cell fusion experiments, suggesting that this complex is of functional significance in the FA pathway. These results indicate that the cellular FA phenotype can be connected to three biochemical subtypes based on the levels of FANCA/FANCG complex. Disruption of the complex may provide an experimental strategy for chemosensitization of neoplastic cells.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Anemia de Fanconi/genética , Proteínas/genética , Proteínas/metabolismo , Fusão Celular , Linhagem Celular , Fragilidade Cromossômica , Proteína do Grupo de Complementação A da Anemia de Fanconi , Proteína do Grupo de Complementação G da Anemia de Fanconi , Teste de Complementação Genética , Humanos , Linfócitos , Biossíntese de Proteínas , Proteínas Recombinantes de Fusão/biossíntese , Transfecção
15.
Nat Genet ; 22(4): 379-83, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10431244

RESUMO

Somatic mosaicism due to reversion of a pathogenic allele to wild type has been described in several autosomal recessive disorders. The best known mechanism involves intragenic mitotic recombination or gene conversion in compound heterozygous patients, whereby one allele serves to restore the wild-type sequence in the other. Here we document for the first time functional correction of a pathogenic microdeletion, microinsertion and missense mutation in homozygous Fanconi anaemia (FA) patients resulting from compensatory secondary sequence alterations in cis. The frameshift mutation 1615delG in FANCA was compensated by two additional single base-pair deletions (1637delA and 1641delT); another FANCA frameshift mutation, 3559insG, was compensated by 3580insCGCTG; and a missense mutation in FANCC(1749T-->G, Leu496Arg) was altered by 1748C-->T, creating a cysteine codon. Although in all three cases the predicted proteins were different from wild type, their cDNAs complemented the characteristic hypersensitivity of FA cells to crosslinking agents, thus establishing a functional correction to wild type.


Assuntos
Proteínas de Ciclo Celular , Proteínas de Ligação a DNA , Anemia de Fanconi/genética , Homozigoto , Mosaicismo , Proteínas Nucleares , Alelos , Sequência de Bases , Relação Dose-Resposta a Droga , Proteína do Grupo de Complementação A da Anemia de Fanconi , Proteína do Grupo de Complementação C da Anemia de Fanconi , Proteínas de Grupos de Complementação da Anemia de Fanconi , Feminino , Mutação da Fase de Leitura , Deleção de Genes , Humanos , Masculino , Metilação , Dados de Sequência Molecular , Fenótipo , Testes de Precipitina , Proteínas/genética , Transfecção
16.
Am J Hum Genet ; 64(5): 1400-5, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10205272

RESUMO

Fanconi anemia (FA) is a genetically heterogeneous autosomal recessive disease with bone marrow failure and predisposition to cancer as major features, often accompanied by developmental anomalies. The cells of patients with FA are hypersensitive to DNA cross-linking agents in terms of cell survival and chromosomal breakage. Of the eight complementation groups (FA-A to FA-H) distinguished thus far by cell fusion studies, the genes for three-FANCA, FANCC, and FANCG-have been identified, and the FANCD gene has been localized to chromosome 3p22-26. We report here the use of homozygosity mapping and genetic linkage analysis to map a fifth distinct genetic locus for FA. DNA from three families was assigned to group FA-E by cell fusion and complementation analysis and was then used to localize the FANCE gene to chromosome 6p21-22 in an 18.2-cM region flanked by markers D6S422 and D6S1610. This study shows that data from even a small number of families can be successfully used to map a gene for a genetically heterogeneous disorder.


Assuntos
Mapeamento Cromossômico , Cromossomos Humanos Par 6/genética , Anemia de Fanconi/genética , Fusão Celular , Feminino , Teste de Complementação Genética/métodos , Marcadores Genéticos/genética , Humanos , Masculino
17.
J Biol Chem ; 274(14): 9821-7, 1999 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-10092672

RESUMO

Activins are members of the transforming growth factor-beta family of growth and differentiation factors. In this paper, we report the results of a structure-function analysis of activin A. The primary targets for directed mutagenesis were charged, individual amino acids located in accessible domains of the protein, concentrating on those that differ from transforming growth factor-beta2, the x-ray crystal structure of which is known. Based on the activities of the recombinant activin mutants in two bioassays, 4 out of 39 mutant proteins (D27K, K102A, K102E, and K102R) produced in a vaccinia virus system were selected for further investigation. After production in insect cells and purification of these four mutants to homogeneity, they were studied in bioassays and in cross-linking experiments involving transfected receptor combinations. Mutant D27K has a 2-fold higher specific bio-activity and binding affinity to an ActRIIA/ALK-4 activin receptor complex than wild type activin, whereas mutant K102E had no detectable biological activity and did not bind to any of the activin receptors. Mutant K102R and wild type activin bound to all the activin receptor combinations tested and were equipotent in bioassays. Our results with the Lys-102 mutants indicate that the positive charge of amino acid 102 is important for biological activity and type II receptor binding of activins.


Assuntos
Inibinas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Receptores de Fatores de Crescimento/metabolismo , Receptores de Activinas Tipo II , Ativinas , Sequência de Aminoácidos , Animais , Folistatina , Glicoproteínas/metabolismo , Células HeLa , Humanos , Inibinas/química , Inibinas/genética , Camundongos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Estrutura Secundária de Proteína , Relação Estrutura-Atividade , Xenopus
18.
Nat Genet ; 20(3): 281-3, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9806548

RESUMO

Fanconi anemia (FA) is an autosomal recessive disease with diverse clinical symptoms including developmental anomalies, bone marrow failure and early occurrence of malignancies. In addition to spontaneous chromosome instability, FA cells exhibit cell cycle disturbances and hypersensitivity to cross-linking agents. Eight complementation groups (A-H) have been distinguished, each group possibly representing a distinct FA gene. The genes mutated in patients of complementation groups A (FANCA; refs 4,5) and C (FANCC; ref. 6) have been identified, and FANCD has been mapped to chromosome band 3p22-26 (ref. 7). An additional FA gene has recently been mapped to chromosome 9p (ref. 8). Here we report the identification of the gene mutated in group G, FANCG, on the basis of complementation of an FA-G cell line and the presence of pathogenic mutations in four FA-G patients. We identified the gene as human XRCC9, a gene which has been shown to complement the MMC-sensitive Chinese hamster mutant UV40, and is suspected to be involved in DNA post-replication repair or cell cycle checkpoint control. The gene is localized to chromosome band 9p13 (ref. 9), corresponding with a known localization of an FA gene.


Assuntos
Proteínas de Ligação a DNA/genética , Anemia de Fanconi/genética , Mutação , Regiões 5' não Traduzidas , Animais , Sequência de Bases , Linhagem Celular , Mapeamento Cromossômico , Cromossomos Humanos Par 9/genética , Cricetinae , DNA Complementar/genética , Proteína do Grupo de Complementação G da Anemia de Fanconi , Feminino , Genes Recessivos , Teste de Complementação Genética , Humanos , Masculino , Dados de Sequência Molecular , Linhagem , Fenótipo
19.
Eur Respir J ; 10(7): 1606-13, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9230255

RESUMO

We studied whether neonatal chronic lung disease (NCLD), hyaline membrane disease (HMD) and differences in ventilatory support affected pulmonary function during the first year of life, in 65 infants born prematurely. The relationship between body weight and oxygen consumption (V'O2) was also analysed. The study comprised 14 infants without cardiorespiratory disease, 19 infants with HMD but without NCLD, 9 infants with NCLD without prior HMD, and 23 infants with NCLD following HMD. At 6 and 12 months corrected postnatal age, static respiratory system compliance (Crs) was measured by weighted spirometry and the functional residual capacity by closed circuit helium dilution (FRCHe) combined with assessment of ventilation distribution from the mixing index (MI). Ventilatory support during the first 5 days of therapy was quantified from peak inspiratory pressure (PIP), mean airway pressure (MAP) and fractional inspiratory concentration of oxygen (FI,O2). Infants with NCLD had a shorter duration of gestation and lower birth weight than those without NCLD (Wilcoxon, p=0.002 and p=0.001, respectively). Pulmonary function at 6 and 12 months corrected age was not different between NCLD infants with or without HMD at birth. Infants with NCLD had lower Crs and MI than those without NCLD (analysis of variance (ANOVA), p<0.011), but their FRCHe was not different. V'O2 adjusted for body weight was comparable in the four groups. PIP and FI,O2 were higher (Wilcoxon, p<0.01) in the NCLD infants than in those with HMD alone, but MAP was not different. Except for FI,O2, these indices were not different among the infants with NCLD. We conclude that birth weight is the major determinant of the development of neonatal chronic lung disease. At 6 and 12 months corrected age, the abnormal pulmonary function is not associated with prior hyaline membrane disease.


Assuntos
Displasia Broncopulmonar/diagnóstico , Doença da Membrana Hialina/terapia , Peso ao Nascer , Peso Corporal , Displasia Broncopulmonar/epidemiologia , Displasia Broncopulmonar/fisiopatologia , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Doença da Membrana Hialina/epidemiologia , Lactente , Recém-Nascido , Masculino , Consumo de Oxigênio , Respiração Artificial , Testes de Função Respiratória
20.
Endocrinology ; 138(7): 2928-36, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9202237

RESUMO

To gain more insight in the mechanism of action of inhibin, we studied the effect of inhibin on activin signaling in Chinese hamster ovary cells. Inhibin specifically counteracted activin-induced expression of a plasminogen activator inhibitor 1 promoter element (3TP) and of the junB gene, but was ineffective when the responses were induced by transforming growth factor-beta. This indicates that inhibin acts only on the activin-specific part of these signaling cascades. Using a constitutively active activin type IB receptor we determined whether inhibin acted at the level of the activin-receptor complex or downstream of it. The mutant activin receptor stimulated the expression of the 3TP promoter in the absence of activin. This stimulation was insensitive to inhibin, indicating that inhibin acts exclusively at or upstream of this activin type I receptor. In addition, competition studies using labeled activin showed that inhibin displaced activin from the activin type II receptors, especially from the activin type IIB receptor, but not from the type I receptors. In conclusion, these data show that in Chinese hamster ovary cells inhibin acts directly at the activin receptor complex, most likely through displacement of activin from the activin type II receptor.


Assuntos
Expressão Gênica/efeitos dos fármacos , Inibinas/metabolismo , Inibinas/farmacologia , Receptores de Fatores de Crescimento/metabolismo , Transdução de Sinais/efeitos dos fármacos , Receptores de Ativinas , Ativinas , Animais , Células CHO , Células COS , Cricetinae , Genes Precoces/efeitos dos fármacos , Camundongos , Inibidor 1 de Ativador de Plasminogênio/genética , Regiões Promotoras Genéticas , Fator de Crescimento Transformador beta/farmacologia
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