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1.
Br J Surg ; 105(9): 1128-1134, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29663316

RESUMO

BACKGROUND: Traditionally, perforated diverticulitis with purulent peritonitis was treated with resection and colostomy (Hartmann's procedure), with inherent complications and risk of a permanent stoma. The DILALA (DIverticulitis - LAparoscopic LAvage versus resection (Hartmann's procedure) for acute diverticulitis with peritonitis) and other randomized trials found laparoscopic lavage to be a feasible and safe alternative. The medium-term follow-up results of DILALA are reported here. METHODS: Patients were randomized during surgery after being diagnosed with Hinchey grade III perforated diverticulitis at diagnostic laparoscopy. The primary outcome was the proportion of patients with one or more secondary operations from 0 to 24 months after the index procedure in the laparoscopic lavage versus Hartmann's procedure groups. The trial was registered as ISRCTN82208287. RESULTS: Forty-three patients were randomized to laparoscopic lavage and 40 to Hartmann's procedure. Patients in the lavage group had a 45 per cent reduced risk of undergoing one or more operations within 24 months (relative risk 0·55, 95 per cent c.i. 0·36 to 0·84; P = 0·012) and had fewer operations (ratio 0·51, 95 per cent c.i. 0·31 to 0·87; P = 0·024) compared with those in the Hartmann's group. No difference was found in mean number of readmissions (1·37 versus 1·50; P = 0·221) or mortality between patients randomized to laparoscopic lavage or Hartmann's procedure. Three patients in the lavage group and nine in the Hartmann's group had a colostomy at 24 months. CONCLUSION: Laparoscopic lavage is a better option for perforated diverticulitis with purulent peritonitis than open resection and colostomy.


Assuntos
Colo/cirurgia , Doença Diverticular do Colo/cirurgia , Perfuração Intestinal/cirurgia , Laparoscopia/métodos , Lavagem Peritoneal/métodos , Peritonite/terapia , Adulto , Idoso , Doença Diverticular do Colo/complicações , Estudos de Viabilidade , Feminino , Seguimentos , Humanos , Perfuração Intestinal/complicações , Tempo de Internação/tendências , Masculino , Pessoa de Meia-Idade , Peritonite/etiologia , Estudos Prospectivos , Ruptura Espontânea , Fatores de Tempo , Resultado do Tratamento
2.
BJS Open ; 5(4)2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34291287

RESUMO

BACKGROUND: Pancreatic neuroendocrine tumours (Pan-NETs) are rare tumours that often present with or develop liver metastases. The aim of this retrospective study was to evaluate liver surgery and thermal hepatic ablation (THA) of Pan-NET liver metastases and to compare the outcomes with those of a control group. METHOD: Patients with Pan-NET treated in Uppsala University Hospital and Sahlgrenska University Hospital from 1995-2018 were included. Patient records were scrutinized for baseline parameters, survival, treatment and complications. RESULTS: Some 108 patients met the criteria for inclusion; 57 patients underwent treatment with liver surgery or THA and 51 constitute the control group. Median follow-up was 3.93 years. Five-year survival in the liver surgery/THA group was 70.6 (95 per cent c.i. 0.57 to 0.84) per cent versus 42.4 (95 per cent c.i. 40.7 to 59.1) per cent in the control group (P = 0.016) and median survival was 9.1 (95 per cent c.i. 6.5 to 11.7) versus 4.3 (95 per cent c.i. 3.4-5.2) years. In a multivariable analysis, surgery or THA was associated with a decreased death-years rate (hazard ratio 0.403 (95 per cent c.i. 0.208 to 0.782, P = 0.007). CONCLUSION: Liver surgery and/or THA was associated with longer overall survival in Pan-NET with acceptable mortality and morbidity rates. These treatments should thus be considered in Pan-NET patients with reasonable tumour burden in an intent to alleviate symptoms and to improve survival.


Assuntos
Neoplasias Hepáticas , Neoplasias Pancreáticas , Hepatectomia , Humanos , Neoplasias Hepáticas/cirurgia , Neoplasias Pancreáticas/cirurgia , Estudos Retrospectivos
3.
Mol Cell Biol ; 8(4): 1625-37, 1988 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2837650

RESUMO

An electrophoretic mobility shift assay was used to characterize interactions of nuclear proteins with a DNA segment in the enhancer element of the leukemogenic murine retrovirus SL3-3. Mutation of a DNA sequence of the 5'-TGTGG-3' type decreased transcription in vivo specifically in T-lymphocyte cell lines. Extracts of nuclei from different T-lymphocyte cell lines or cells from lymphoid organs resulted in much higher amounts of complexes in vitro with this DNA sequence than did extracts from other cell lines or organs tested. Differences were also found in the sets of complexes obtained with extracts from the different types of cells. The DNA sequence specificities of the different SL3-3 enhancer factor 1 (SEF1) protein complexes were found to be distinct from those of several other previously identified DNA motifs of the TGTGG type because of differences in several nucleotides critical for binding and because these other DNA motifs could not compete with the identified DNA sequence for binding of SEF1. Limited treatment with several different proteases cleaved the SEF1 proteins such that their DNA-binding domain(s) remained and created complexes with decreased and nondistinguishable electrophoretic mobility shifts and with new properties. These results indicate that the SEF1 proteins have a structure with a flexible and relatively vulnerable hinge region linking a DNA-binding domain(s) to a more variable domain(s) with other functions. We suggest that the binding of SEF1 is an essential factor for the T-cell tropism of SL3-3 and the ability of this virus to cause T-cell lymphomas.


Assuntos
Elementos Facilitadores Genéticos , Genes Virais , Vírus da Leucemia Murina/genética , Linfócitos/metabolismo , Proteínas Nucleares/metabolismo , Animais , Sequência de Bases , Linhagem Celular , Humanos , Metilação , Mutação , Plasmídeos , Transcrição Gênica
4.
Am J Psychiatry ; 155(5): 696-8, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9585726

RESUMO

OBJECTIVE: The authors' goal was to explore the nature of attention deficit hyperactivity disorder (ADHD) in African American children, which has received scant attention by psychiatric researchers. METHOD: Subjects were 19 African American children with DSM-III-R ADHD and 24 African American children without ADHD. Ethnically sensitive methods were used to evaluate the children comprehensively. The findings were compared with those from an earlier study of Caucasian children with ADHD. RESULTS: African American children with ADHD had higher levels of psychiatric disorders other than ADHD than did African American children who did not have ADHD. CONCLUSIONS: Among African American children, ADHD may be characterized by a narrower pattern of psychiatric comorbidity and dysfunction than has been observed in Caucasians. Given the small number of subjects studied, these findings are preliminary and must be replicated to confirm their validity.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Negro ou Afro-Americano/estatística & dados numéricos , Adolescente , Fatores Etários , Transtorno do Deficit de Atenção com Hiperatividade/epidemiologia , Criança , Comorbidade , Humanos , Transtornos Mentais/diagnóstico , Transtornos Mentais/epidemiologia , Escalas de Graduação Psiquiátrica/estatística & dados numéricos , Reprodutibilidade dos Testes , População Branca/estatística & dados numéricos
5.
J Am Acad Child Adolesc Psychiatry ; 36(1): 21-9, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9000777

RESUMO

OBJECTIVE: To evaluate whether attention-deficit hyperactivity disorder (ADHD) is a risk factor for psychoactive substance use disorders (PSUD), attending to issues of psychiatric comorbidity, family history, and adversity. METHOD: Using assessments from multiple domains, the authors examined 140 ADHD and 120 normal control subjects at baseline and 4 years later. Drug and alcohol abuse and dependence were operationally defined. RESULTS: No differences were detected in the rates of alcohol or drug abuse or dependence or in the rates of abuse of individual substances between the groups; both ADHD and control probands had a 15% rate of PSUD. Conduct and bipolar disorders predicted PSUD, independently of ADHD status. Family history of substance dependence and antisocial disorders was associated with PSUD in controls but less clearly so in ADHD probands. Family history of ADHD was not associated with risk for PSUD. ADHD probands had a significantly shorter time period between the onsets of abuse and dependence compared with controls (1.2 years versus 3 years, p < .01). CONCLUSIONS: Adolescents with and without ADHD had a similar risk for PSUD that was mediated by conduct and bipolar disorder. Since the risk for PSUD has been shown to be elevated in adults with ADHD when compared with controls, a sharp increase in PSUD is to be expected in grown-up ADHD children during the transition from adolescence to adulthood.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/complicações , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Adolescente , Adulto , Transtorno Bipolar/complicações , Estudos de Casos e Controles , Criança , Transtornos do Comportamento Infantil/complicações , Estudos de Coortes , Saúde da Família , Humanos , Masculino , Análise de Regressão , Estados Unidos/epidemiologia
6.
J Am Acad Child Adolesc Psychiatry ; 36(11): 1552-9; discussion 1559-60, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9394940

RESUMO

OBJECTIVE: Although a small literature of case reports suggests that mania co-occurs with pervasive developmental disorder (PDD), little is known about this overlap. The authors systematically investigated the overlap between mania and PDD in a consecutive sample of referred youths, examining its prevalence and correlates. It was hypothesized that children with PDD plus manic features have both disorders. METHOD: Subjects were consecutively referred children meeting diagnostic criteria on structured interview for PDD without mania (n = 52), the comorbid condition PDD + mania (n = 14), and mania without PDD (n = 114). All subjects were evaluated using a comprehensive diagnostic battery that included assessment of psychopathology (structured diagnostic interview and Child Behavior Checklist), cognition, and functioning. RESULTS: Of the 727 referred children, 52 met criteria for PDD, 114 met criteria for mania, and 14 met criteria for both. The 14 children with both PDD + mania represented 21% of the PDD subjects and 11% of all manic subjects. Clinical characteristics of PDD were similar in PDD subjects with and without mania, and manic features were similar in manic children with and without PDD. CONCLUSIONS: Children with PDD and mania may suffer from two disorders. Comorbid mania among patients with PDD may be more common than previously thought. Identification of the comorbid condition may have important therapeutic and scientific implications.


Assuntos
Transtorno Bipolar/epidemiologia , Transtornos Globais do Desenvolvimento Infantil/epidemiologia , Transtorno Bipolar/psicologia , Criança , Transtornos Globais do Desenvolvimento Infantil/psicologia , Comorbidade , Feminino , Humanos , Masculino , Prevalência
7.
J Am Acad Child Adolesc Psychiatry ; 38(1): 34-9, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9893414

RESUMO

BACKGROUND: Very little is known about attention-deficit hyperactivity disorder (ADHD) in African-American children, and although the familial transmission of ADHD has been well established in white samples, prior work has not evaluated this feature of ADHD in African-American families. METHOD: Subjects were 37 first-degree relatives of children with DSM-III-R-defined ADHD and 52 first-degree relatives of non-ADHD comparison children matched for ethnicity, age, and gender. DSM-III-R-based structured interviews (modified to include DSM-IV diagnoses) provided the basis for psychiatric diagnoses in relatives. RESULTS: The risks for both DSM-III-R and DSM-IV ADHD were significantly greater in first-degree relatives of ADHD probands than in relatives of controls. In addition, the relatives of ADHD probands also were at higher risk for oppositional defiant disorder, antisocial personality disorder, major depression, generalized anxiety, and substance use disorders. CONCLUSIONS: These results suggest that ADHD and related disorders are familial in African-Americans. Further work is needed to confirm the familial transmission of ADHD in African-American children and to explore the role of genetics as well as environmental factors in the transmission of the disorder.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/etnologia , Negro ou Afro-Americano/psicologia , Família/psicologia , Adolescente , Negro ou Afro-Americano/estatística & dados numéricos , Transtorno do Deficit de Atenção com Hiperatividade/genética , População Negra , Estudos de Casos e Controles , Criança , Feminino , Humanos , Modelos Logísticos , Masculino , Projetos Piloto , Estados Unidos/epidemiologia
8.
Neurobiol Aging ; 32(12): 2314-5, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20097445

RESUMO

We have established a novel transgenic rat line carrying human microtubule-associated protein Tau-40 with mutation P301L. hTau-40/P301L transgenic male and female rats were followed up to 2 years of age. The hTau-40/P301L rats expressed human tau mRNA and protein in the limbic cortex and associated white matter, hippocampus and spinal cord. With increasing age, the staining density for phosphorylated tau increased in all these areas. Neither silver stains nor Fluoro-Jade staining indicated the presence of dying neurons, or axonal degeneration, and there was no evidence of increased gliosis or inflammation. However, some neurons did display dendritic abnormalities, and immunoblots revealed the presence of sarcosyl insoluble tau. A large test battery revealed no behavioral abnormalities in these rats, except a mild hyperactivity in the elevated plus maze. In conclusion, this transgenic tau rat may be a useful model for 'pretangle' pathology, although in this study conditions were not sufficient to induce significant neuronal loss or behavioral deficits.


Assuntos
Química Encefálica/genética , Modelos Animais , Mutação/genética , Proteínas tau/química , Proteínas tau/genética , Animais , Feminino , Hipocampo/química , Hipocampo/metabolismo , Humanos , Sistema Límbico/química , Sistema Límbico/metabolismo , Masculino , Ratos , Ratos Transgênicos , Medula Espinal/química , Medula Espinal/metabolismo
9.
Inflamm Res ; 54(5): 194-203, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15953991

RESUMO

OBJECTIVE: Our aim was to study how different SERMs modulate the inflammatory responses induced by lipopolysaccharide (LPS) or unmethylated CpG-oligonucleotides in mouse and rat microglial cells. MATERIALS AND METHODS: Inflammatory responses of mouse N9 microglial cells and rat primary hippocampal microglia to lipopolysaccharide (LPS) exposure were recorded by the secretion of nitric oxide (NO) and cytokine IL-6 in two models where SERM was added either 24 h before LPS addition or simultaneously or even after the LPS exposure. The responses of 17beta-estradiol, tamoxifen, raloxifene and ICI 182.780 were compared. Responses were recorded by ELISA, Northern and EMSA assays. RESULTS: SERMs but not 17beta-estradiol induced a significant, concentration-dependent anti-inflammatory response both in rat primary microglial cells and in mouse N9 microglial cells. The response was observed both in NO and IL-6 secretion as well as in total IL-6 mRNA expression. We have recently observed that histone deacetylase (HDAC) inhibitors can potentiate the LPS-induced inflammatory response. Raloxifene and tamoxifen inhibited the potentiation of LPS response induced by trichostatin A, an HDAC inhibitor, in N9 microglia. A SERM-induced anti-inflammatory response was observed in acute models where SERM was added simultaneously or even up to 6 h later than LPS exposure. In contrast, the pretreatment of N9 microglia with tamoxifen or raloxifene for 30 h before LPS exposure did not provide any protection against the LPS response. We also observed that the raloxifene-induced protection in N9 microglia was connected to a decline of LPS-induced DNA binding activity of AP-1 but not that of NF-kappaB transcription factors. CONCLUSIONS: Our results show that tamoxifen, raloxifene and ICI 182.780 induce an anti-inflammatory response in acute models of mouse and rat microglial cells. It seems that this response is not estrogen receptor-mediated but, probably, is attributable to some SERM-induced modulation of LPS-activated pro-inflammatory signalling cascades.


Assuntos
Anti-Inflamatórios/farmacologia , Inflamação/tratamento farmacológico , Microglia/patologia , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Animais , Astrócitos/citologia , Northern Blotting , Proliferação de Células , Células Cultivadas , Ilhas de CpG , DNA/metabolismo , Relação Dose-Resposta a Droga , Regulação para Baixo , Ensaio de Imunoadsorção Enzimática , Estradiol/análogos & derivados , Estradiol/metabolismo , Estradiol/farmacologia , Fulvestranto , Hipocampo/citologia , Inibidores de Histona Desacetilases , Histona Desacetilases/metabolismo , Humanos , Interleucina-6/sangue , Interleucina-6/metabolismo , L-Lactato Desidrogenase/metabolismo , Lipopolissacarídeos/metabolismo , Camundongos , Microglia/metabolismo , Óxido Nítrico/metabolismo , Oligonucleotídeos/metabolismo , Ligação Proteica , RNA Mensageiro/metabolismo , Cloridrato de Raloxifeno/farmacologia , Ratos , Ratos Wistar , Tamoxifeno/farmacologia , Fatores de Tempo
10.
J Virol ; 65(1): 42-50, 1991 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1985206

RESUMO

Interactions between SL3-3 enhancer factor 1 (SEF1) proteins and the enhancer of the murine leukemia virus SL3-3 were analyzed. SEF1 proteins were found to interact with two different DNA sequences within the DNA repeat region of the enhancer; these two motifs cooperated in enhancing initiation of transcription in T lymphocytes. Using an electrophoretic mobility shift assay, we identified nucleotides that are important for the SEF1 binding, and we deduced a sequence, 5'-TTTGCGGTTA/T-3' with highly improved binding of SEF1 proteins. We show that many different SEF1 binding sequences exist in the transcription control regions of different viral and cellular genes. The results indicate a general role of SEF1 proteins in T-cell gene expression.


Assuntos
Cromossomos/metabolismo , Proteínas de Ligação a DNA/metabolismo , Elementos Facilitadores Genéticos , Genes Virais , Transativadores/metabolismo , Animais , Sequência de Bases , Sítios de Ligação , Linhagem Celular , Células HeLa/metabolismo , Humanos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Sondas de Oligonucleotídeos , Ligação Proteica , Sequências Repetitivas de Ácido Nucleico , Retroviridae/genética , Homologia de Sequência do Ácido Nucleico , Software , Transcrição Gênica
11.
J Biol Chem ; 268(29): 21946-54, 1993 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-8408051

RESUMO

Binding sites for SL3-3 enhancer factor 1 (SEF1) are important for the transcriptional activity in T lymphocytes and the tumorigenicity of SL3-3 murine leukemia virus. SEF1 is also implicated in the activity of many other leukemia, lymphoma, and sarcoma virus enhancers, and enhancers of genes for T cell receptor-CD3 subunits. We have purified several proteins binding to SEF1 sites from bovine thymus using a five-step purification procedure. The proteins migrated as 19 distinct bands representing molecular masses from 23 kDa to about 200 kDa in SDS-polyacrylamide gel electrophoresis. Ten DNA binding proteins, with molecular masses between 23 and 67 kDa, could be isolated after separation by SDS-polyacrylamide gel electrophoresis. The DNA binding specificities of these proteins were similar and corresponded to that of the SEF1 binding activity in nuclear extracts. Each of these isolated SEF1 proteins also bound to the essential delta-E3 element of the human T cell receptor delta enhancer. Antibodies against one SEF1 protein only reacted with the protein used for immunization, which indicates a limited homology between at least some SEF1 proteins. We also present data suggesting that SEF1 proteins exist in multiple forms with differences in their DNA binding specificity, and that high affinity DNA binding of the SEF1 proteins requires protein phosphorylation.


Assuntos
Proteínas de Ligação a DNA/isolamento & purificação , Elementos Facilitadores Genéticos , Proteínas de Neoplasias , Linfócitos T/metabolismo , Fatores de Transcrição/isolamento & purificação , Transcrição Gênica , Animais , Sequência de Bases , Sítios de Ligação , Complexo CD3/metabolismo , Bovinos , DNA/metabolismo , Proteínas de Ligação a DNA/metabolismo , Dados de Sequência Molecular , Fosforilação , Receptores de Antígenos de Linfócitos T/metabolismo , Timo/metabolismo , Fatores de Transcrição/metabolismo
12.
Nucleic Acids Res ; 20(24): 6495-9, 1992 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-1480471

RESUMO

A family of proteins, denoted SL3-3 enhancer factor 1 (SEF1), interacts with DNA sequences in the T cell specific enhancer of SL3-3 murine leukemia virus and in the enhancers of several other viruses. A putative SEF1 binding site was also identified in the T cell specific enhancer of the gene encoding the human T cell antigen receptor (TcR) associated CD3-epsilon polypeptide. In this study we show that the identified sequence is a strong SEF1 binding site, and that purified SEF1 proteins bind specifically to the sequence. We report also that the SEF1 binding site is important for T cell specific activation of transcription by the CD3-epsilon enhancer. We show that SEF1 binding sites are present also in the T cell specific enhancers of other subunits of the TcR-CD3 complex, and that SEF1 proteins appear to play a central role in the T cell specific expression of this set of enhancers.


Assuntos
Complexo CD3/genética , Proteínas de Ligação a DNA/metabolismo , Elementos Facilitadores Genéticos , Proteínas de Neoplasias , Receptores de Antígenos de Linfócitos T/genética , Linfócitos T/imunologia , Fatores de Transcrição/metabolismo , Animais , Sequência de Bases , Bovinos , Linhagem Celular , Núcleo Celular/metabolismo , Eletroforese em Gel de Poliacrilamida , Humanos , Camundongos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Ligação Proteica , Homologia de Sequência do Ácido Nucleico , Timo/imunologia
13.
Nucleic Acids Res ; 17(11): 4061-75, 1989 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-2544855

RESUMO

Nuclear factor I (NFI) is shown to be of importance for the activity of the enhancer element of a T-cell leukemogenic murine retrovirus, SL3-3, and for the regulation of this element by glucocorticoid. Each nucleotide of the binding site of the NFI proteins was mutated, and the effects of the mutations were quantitated with an electrophoretic mobility shift assay. Mutations in the inverted repeat of the binding site have symmetric effects which strongly support the notion that NFI proteins preferentially bind to dyad symmetry sites. Such binding sites were shown to be more than 100 fold stronger than the corresponding single binding sites. We find dyad symmetry sequences which are much stronger NFI binding sites than NFI sites identified in different genes and also stronger than previously proposed consensus binding sequences for NFI.


Assuntos
Sequência de Bases , Proteínas Estimuladoras de Ligação a CCAAT , Análise Mutacional de DNA , Proteínas de Ligação a DNA/genética , Elementos Facilitadores Genéticos , Vírus da Leucemia Murina/genética , Fatores de Transcrição , Animais , Composição de Bases , Ligação Competitiva , Linhagem Celular , Deleção Cromossômica , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica , Histonas/metabolismo , Camundongos , Dados de Sequência Molecular , Fatores de Transcrição NFI , Proteínas Nucleares , Coelhos , Proteína 1 de Ligação a Y-Box
14.
J Virol ; 65(11): 6084-93, 1991 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1681116

RESUMO

A family of nuclear proteins, designated SL3-3 enhancer factors 2 (SEF2), were found to interact with an Ephrussi box-like motif within the glucocorticoid response element in the enhancer of the murine leukemia virus SL3-3. Mutation of the DNA sequence decreased the basal enhancer activity in various cell lines. The important nucleotides for binding of SEF2 are conserved in most type C retroviruses. Various cell types displayed differences both in the sets of SEF2-DNA complexes formed and in their amounts. A cDNA which encoded a protein that interacted specifically with the SEF2-binding sequence was isolated from human thymocytes. The nucleotide sequence specificity of the recombinant protein, expressed in Escherichia coli, corresponded to that of at least one of the nuclear SEF2 proteins. Sequence analysis of the cDNA revealed that it belongs to the basic helix-loop-helix class of DNA-binding proteins. Several mRNA transcripts of different sizes were identified. Molecular analysis of cDNA clones revealed multiple related mRNA species containing alternative coding regions, which are most probably a result of differential splicing.


Assuntos
Proteínas de Ligação a DNA , Elementos Facilitadores Genéticos , Vírus da Leucemia Murina/genética , Proteínas do Tecido Nervoso , Proteínas Nucleares/metabolismo , Receptores de Glucocorticoides/metabolismo , Transativadores/metabolismo , Fatores de Transcrição , Transcrição Gênica , Sequência de Aminoácidos , Animais , Sequência de Bases , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Sítios de Ligação , Northern Blotting , Linhagem Celular , Clonagem Molecular/métodos , Escherichia coli/genética , Células HeLa , Humanos , Camundongos , Dados de Sequência Molecular , Peso Molecular , Oligodesoxirribonucleotídeos , Poli A/análise , Poli A/genética , RNA Mensageiro/análise , RNA Mensageiro/genética , Homologia de Sequência do Ácido Nucleico , Fatores de Transcrição TCF , Fator de Transcrição 4 , Proteína 2 Semelhante ao Fator 7 de Transcrição , Transfecção
15.
Nature ; 368(6473): 760-4, 1994 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-8152489

RESUMO

The ubiquitous Ca(2+)-binding protein calmodulin (CaM) is a key protein in Ca2+ homeostasis and activation of eukaryotic cells. CaM is the molecular link between free Ca2+ in the cell and the inhibition, or activation, of numerous enzymes. Many nuclear functions are under Ca2+/CaM control, and some transcriptional activators are known to be Ca2+ modulated indirectly through Ca2+/CaM-dependent protein kinases. But Ca2+/CaM has not yet been found to directly modulate any transcription factor or other DNA-binding protein. Transcription factors of the basic-helix-loop-helix (bHLH) group are important regulators in numerous systems. Here we report that binding of Ca(2+)-loaded CaM to the bHLH domains of several bHLH proteins directly inhibits their DNA binding. Other bHLH proteins are either less sensitive or resistant. Ca2+ ionophore selectively inhibits transcriptional activation by Ca2+/CaM-sensitive bHLH proteins in vivo, implying that Ca2+ can directly influence transcription through differential CaM inhibition of bHLH domains.


Assuntos
Cálcio/fisiologia , Calmodulina/fisiologia , Sequências Hélice-Alça-Hélice/fisiologia , Fatores de Transcrição/fisiologia , Transcrição Gênica/fisiologia , Animais , Sequência de Bases , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Bovinos , Linhagem Celular , Reagentes de Ligações Cruzadas/farmacologia , DNA/metabolismo , Proteínas de Ligação a DNA/fisiologia , Glutaral/farmacologia , Humanos , Ionomicina/farmacologia , Camundongos , Dados de Sequência Molecular , Ligação Proteica
16.
Immunity ; 7(5): 591-9, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9390683

RESUMO

A major issue is whether surface expression of the pre-TCR is necessary for signaling the development of immature thymocytes. To address this question, we generated transgenic mice expressing a TCRbeta chain that had a strong endoplasmic reticulum (ER) retrieval signal (TCRbetaER) and that was expressed intracellularly but failed to reach the cell surface. In TCRbetaER transgenic mice, there was a failure of allelic exclusion. Also, the transgene failed to rescue the developmental defects observed in TCRbeta-null mice. In contrast, TCRbeta transgenes with a mutant ER retrieval sequence or lacking this sequence signaled efficient allelic exclusion and suppressed the TCRbeta-/- defect. These data show that exit of the pre-TCR from the ER/cis-Golgi is required for progression through the double-negative thymocyte checkpoint.


Assuntos
Retículo Endoplasmático Rugoso/metabolismo , Rearranjo Gênico da Cadeia beta dos Receptores de Antígenos dos Linfócitos T , Complexo de Golgi/metabolismo , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Linfócitos T/citologia , Timo/citologia , Alelos , Sequência de Aminoácidos , Animais , Cálcio/metabolismo , Diferenciação Celular , Divisão Celular , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular , Processamento de Proteína Pós-Traducional , Receptores de Antígenos de Linfócitos T alfa-beta/genética
17.
Cell ; 89(5): 765-71, 1997 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-9182764

RESUMO

We have generated Cbfa1-deficient mice. Homozygous mutants die of respiratory failure shortly after birth. Analysis of their skeletons revealed an absence of osteoblasts and bone. Heterozygous mice showed specific skeletal abnormalities that are characteristic of the human heritable skeletal disorder, cleidocranial dysplasia (CCD). These defects are also observed in a mouse Ccd mutant for this disease. The Cbfa1 gene was shown to be deleted in the Ccd mutation. Analysis of embryonic Cbfa1 expression using a lacZ reporter gene revealed strong expression at sites of bone formation prior to the earliest stages of ossification. Thus, the Cbfa1 gene is essential for osteoblast differentiation and bone formation, and the Cbfa1 heterozygous mouse is a paradigm for a human skeletal disorder.


Assuntos
Desenvolvimento Ósseo/genética , Displasia Cleidocraniana/genética , Proteínas de Neoplasias , Osteoblastos/patologia , Fatores de Transcrição/genética , Animais , Diferenciação Celular/genética , Subunidade alfa 1 de Fator de Ligação ao Core , Deleção de Genes , Marcação de Genes , Humanos , Camundongos , Camundongos Mutantes , Síndrome
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