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1.
Br J Oral Maxillofac Surg ; 56(4): 267-271, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29525294

RESUMO

The aims of this study were to find the incidence of bifurcation of the inferior dental nerve (IDN) canal, to describe the characteristics of this variant, and to examine the sensitivity and specificity of dental panoramic tomography to identify it. We classified bifurcations by size and position relative to the main canal and the lower third molar using cone-beam computed tomography (CT) and dental panoramic tomography. In our study of 281 patients, 106 (38%) had bifurcations, and in one quarter, these were classified as large accessory canals. Bifurcations were most commonly found posterior to the lower third molar (n=64, 57%) or within 2mm of the roots of the third molar (n=40, 38%). The sensitivity and specificity of dental panoramic tomography to identify all bifurcations was 11% (95% CI: 5.67 to 17.97) and 91% (95% CI: 85.58 to 94.68), respectively; this was 33% (95% CI: 15.63 to 55.32) and 94% (95% CI: 90.34 to 96.50), respectively, for large bifurcations. Our use of cone-beam CT suggested an incidence of bifid canals of 38%, with a variation in size and distribution in relation to the lower third molar. It also showed that the sensitivity of panoramic radiography to identify them was poor.


Assuntos
Nervo Mandibular/anormalidades , Adolescente , Adulto , Idoso , Tomografia Computadorizada de Feixe Cônico , Feminino , Humanos , Masculino , Mandíbula/anormalidades , Mandíbula/anatomia & histologia , Mandíbula/diagnóstico por imagem , Mandíbula/inervação , Nervo Mandibular/anatomia & histologia , Nervo Mandibular/diagnóstico por imagem , Pessoa de Meia-Idade , Dente Serotino/anatomia & histologia , Dente Serotino/diagnóstico por imagem , Radiografia Panorâmica , Adulto Jovem
2.
Leukemia ; 31(5): 1096-1107, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-27890928

RESUMO

Although pathologically activated ABL1 fusion kinases represent well-validated therapeutic targets, tumor genomic sequencing has identified numerous point mutations in the ABL1 proto-oncogene of unclear significance. Here we describe ten novel ABL1 1b point mutations, including two from clinical isolates, that cause constitutive kinase activation and cellular transformation. All mutants retained sensitivity to ATP-competitive tyrosine kinase inhibitors (TKIs). Several substitutions cluster near the myristoyl-binding pocket, the target of ABL001, a novel clinically active allosteric kinase inhibitor that mimics the autoinhibitory myristoyl group, and likely activate the kinase by relieving physiologic autoinhibition. In addition, several mutations activate the kinase and confer resistance to allosteric inhibition despite a lack of proximity to this region. We demonstrate that BCR-ABL1 and ABL1 1b point mutations can co-exist in a proportion of clinical cases as a consequence of the chromosome 9 breakpoint location. Collectively, our findings support clinical investigation of ATP-competitive TKIs in malignancies harboring ABL1 point mutations, and sequencing of BCR-ABL1 and ABL1 1b in patients with acquired resistance to allosteric ABL1 inhibitors.


Assuntos
Mutação Puntual/genética , Proteínas Proto-Oncogênicas c-abl/genética , Trifosfato de Adenosina , Regulação Alostérica , Sítios de Ligação , Linhagem Celular , Ativação Enzimática , Proteínas de Fusão bcr-abl , Humanos , Ácido Mirístico/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proto-Oncogene Mas , Análise de Sequência de DNA
3.
Br J Oral Maxillofac Surg ; 54(8): 868-871, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27266976

RESUMO

We present our experience of launching the adult treatment clinic - a daytime clinic for semiurgent referrals to oral and maxillofacial surgery (OMFS). This has proved to be an effective way in which cross-covering junior doctors could refer patients for a safe and efficient review in a supervised environment.


Assuntos
Auditoria Médica , Encaminhamento e Consulta , Cirurgia Bucal , Adulto , Humanos
5.
Crit Rev Food Sci Nutr ; 56(16): 2628-41, 2016 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-25629818

RESUMO

Probiotics are live microorganisms, which when administered in food confer numerous health benefits. In previous studies about beneficial effects of probiotic bacteria to health, particularly in the fields of intestinal mucosa defense responses, specific probiotics, in a strain-dependent manner, show certain degree of potential to reinforce the integrity of intestinal epithelium and/or regulate some immune components. The mechanism of probiotic action is an area of interest. Among all possible routes of modulation by probiotics of intestinal epithelial cell-mediated defense responses, modulations of intestinal barrier function, innate, and adaptive mucosal immune responses, as well as signaling pathways are considered to play important role in the intestinal defense responses against pathogenic bacteria. This review summarizes the beneficial effects of probiotic bacteria to intestinal health together with the mechanisms affected by probiotic bacteria: barrier function, innate, and adaptive defense responses such as secretion of mucins, defensins, trefoil factors, immunoglobulin A (IgA), Toll-like receptors (TLRs), cytokines, gut associated lymphoid tissues, and signaling pathways.


Assuntos
Microbioma Gastrointestinal , Mucosa Intestinal/microbiologia , Probióticos , Imunidade Adaptativa/fisiologia , Animais , Defensinas/imunologia , Defensinas/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Humanos , Imunidade Inata/fisiologia , Imunoglobulina A/imunologia , Imunoglobulina A/metabolismo , Mucosa Intestinal/citologia , Mucinas/imunologia , Mucinas/metabolismo , Transdução de Sinais , Receptores Toll-Like/imunologia , Receptores Toll-Like/metabolismo , Fatores Trefoil/imunologia , Fatores Trefoil/metabolismo
8.
Leukemia ; 29(12): 2390-2, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26108694

RESUMO

Activating mutations in FLT3 occur in ~30% of adult acute myeloid leukemia, primarily consisting of internal tandem duplication (ITD) mutations (~25%) and point mutations in the tyrosine kinase domain (~5%), commonly at the activation loop residue D835. Secondary kinase domain mutations in FLT3-ITD, particularly at the D835 residue are frequently associated with acquired clinical resistance to effective FLT3 tyrosine kinase inhibitors (TKIs). Molecular docking studies have suggested that D835 mutations primarily confer resistance by stabilizing an active Asp-Phe-Gly in ('DFG-in') kinase conformation unfavorable to the binding of type II FLT3 TKIs, which target a 'DFG-out' inactive conformation. We profiled the activity of active type II FLT3 TKIs against D835 kinase domain mutants that have been clinically detected to date. We found that type II inhibitors (quizartinib, sorafenib, ponatinib and PLX3397) retain activity against specific D835 substitutions. Modeling studies suggest that bulky hydrophobic substitutions (D835Y/V/I/F) at this residue are particularly resistant, whereas mutations that preserve interactions between D835 and S838 are relatively sensitive (D835E/N). All mutants retain sensitivity to the type I inhibitor crenolanib. These results suggest that patients with relatively sensitive D835 mutations should be included in clinical trials of type II FLT3 TKIs.


Assuntos
Mutação , Inibidores de Proteínas Quinases/farmacologia , Tirosina Quinase 3 Semelhante a fms/antagonistas & inibidores , Tirosina Quinase 3 Semelhante a fms/genética , Resistencia a Medicamentos Antineoplásicos , Humanos , Simulação de Acoplamento Molecular , Conformação Proteica , Tirosina Quinase 3 Semelhante a fms/química
9.
J Dent Res ; 94(4): 534-9, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25710950

RESUMO

Medication-related osteonecrosis of the jaw (MRONJ), although initially believed to be exclusively associated with bisphosphonates, has been implicated in recent reports with additional drugs, especially the bone antiresorptive denosumab. The pathophysiology has not been fully elucidated, and no causal association between bone antiresorptive regimens and MRONJ has yet been established. However, reduced bone turnover and infection, an almost universal finding, are thought to be central to the pathogenesis of MRONJ. Both bisphosphonates and denosumab, through different pathways of action, significantly reduce the rate of bone turnover and potentially reduce the efficacy of the host defense against infection. Recent evidence questions the simplified etiology of low bone turnover causing MRONJ and offers evidence on the prominent role of infection instead. The management of MRONJ remains a significant clinical challenge, with little progress having been made on treatment. The aim of this article is to explore the current theories on the etiology of MRONJ and to emphasize the importance of infection in the development of this devastating pathology.


Assuntos
Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/etiologia , Conservadores da Densidade Óssea/efeitos adversos , Anticorpos Monoclonais Humanizados/efeitos adversos , Biofilmes , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/microbiologia , Remodelação Óssea/efeitos dos fármacos , Denosumab , Interações Hospedeiro-Patógeno/imunologia , Humanos , Ligante RANK/antagonistas & inibidores
10.
Ann Oncol ; 25(4): 852-858, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24667717

RESUMO

BACKGROUND: This report examines (99m)Tc-etarfolatide imaging to identify the presence of folate receptor (FR) on tumors of women with recurrent/refractory ovarian or endometrial cancer and correlates expression with response to FR-targeted therapy (vintafolide). PATIENTS AND METHODS: In this phase II, single-arm, multicenter study, patients with advanced ovarian cancer were imaged with (99m)Tc-etarfolatide before vintafolide treatment. Up to 10 target lesions (TLs) were selected based on Response Evaluation Criteria In Solid Tumors criteria using computed tomography scans. Single-photon emission computed tomography images of TLs were assessed for (99m)Tc-etarfolatide uptake as either FR positive or negative. Patients were categorized by percentage of TLs positive and grouped as FR(100%), FR(10%-90%), and FR(0%). Lesion and patient response were correlated with etarfolatide uptake. RESULTS: Forty-nine patients were enrolled; 43 were available for analysis. One hundred thirty-nine lesions were (99m)Tc-etarfolatide evaluable: 110 FR positive and 29 FR negative. Lesion disease control rate (DCR = stable or response) was observed in 56.4% of FR-positive lesions versus 20.7% of FR-negative lesions (P < 0.001). Patient DCR was 57%, 36%, and 33% in FR(100%), FR(10%-90%), and FR(0%) patients, respectively. Median overall survival was 14.6, 9.6, and 3.0 months in FR(100%), FR(10%-90%), and FR(0%) patients, respectively. CONCLUSIONS: Overall response to FR-targeted therapy and DCR correlate with FR positivity demonstrated by (99m)Tc-etarfolatide imaging. CLINICAL TRIAL NUMBER: NCT00507741.


Assuntos
Receptor 1 de Folato/metabolismo , Ácido Fólico/análogos & derivados , Compostos de Organotecnécio/administração & dosagem , Neoplasias Ovarianas/tratamento farmacológico , Alcaloides de Vinca/administração & dosagem , Adulto , Idoso , Diagnóstico por Imagem , Feminino , Ácido Fólico/administração & dosagem , Humanos , Pessoa de Meia-Idade , Terapia de Alvo Molecular , Estadiamento de Neoplasias , Neoplasias Ovarianas/diagnóstico por imagem , Neoplasias Ovarianas/patologia , Radiografia , Tomografia Computadorizada de Emissão de Fóton Único
11.
N Engl J Med ; 369(19): 1783-96, 2013 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-24180494

RESUMO

BACKGROUND: Ponatinib is a potent oral tyrosine kinase inhibitor of unmutated and mutated BCR-ABL, including BCR-ABL with the tyrosine kinase inhibitor-refractory threonine-to-isoleucine mutation at position 315 (T315I). We conducted a phase 2 trial of ponatinib in patients with chronic myeloid leukemia (CML) or Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL). METHODS: We enrolled 449 heavily pretreated patients who had CML or Ph-positive ALL with resistance to or unacceptable side effects from dasatinib or nilotinib or who had the BCR-ABL T315I mutation. Ponatinib was administered at an initial dose of 45 mg once daily. The median follow-up was 15 months. RESULTS: Among 267 patients with chronic-phase CML, 56% had a major cytogenetic response (51% of patients with resistance to or unacceptable side effects from dasatinib or nilotinib and 70% of patients with the T315I mutation), 46% had a complete cytogenetic response (40% and 66% in the two subgroups, respectively), and 34% had a major molecular response (27% and 56% in the two subgroups, respectively). Responses were observed regardless of the baseline BCR-ABL kinase domain mutation status and were durable; the estimated rate of a sustained major cytogenetic response of at least 12 months was 91%. No single BCR-ABL mutation conferring resistance to ponatinib was detected. Among 83 patients with accelerated-phase CML, 55% had a major hematologic response and 39% had a major cytogenetic response. Among 62 patients with blast-phase CML, 31% had a major hematologic response and 23% had a major cytogenetic response. Among 32 patients with Ph-positive ALL, 41% had a major hematologic response and 47% had a major cytogenetic response. Common adverse events were thrombocytopenia (in 37% of patients), rash (in 34%), dry skin (in 32%), and abdominal pain (in 22%). Serious arterial thrombotic events were observed in 9% of patients; these events were considered to be treatment-related in 3%. A total of 12% of patients discontinued treatment because of an adverse event. CONCLUSIONS: Ponatinib had significant antileukemic activity across categories of disease stage and mutation status. (Funded by Ariad Pharmaceuticals and others; PACE ClinicalTrials.gov number, NCT01207440 .).


Assuntos
Imidazóis/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Piridazinas/uso terapêutico , Trombose/induzido quimicamente , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imidazóis/efeitos adversos , Masculino , Pessoa de Meia-Idade , Inibidores de Proteínas Quinases/efeitos adversos , Piridazinas/efeitos adversos , Trombocitopenia/induzido quimicamente , Adulto Jovem
12.
J Food Sci ; 75(5): M278-82, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20629884

RESUMO

This study examined the survival of probiotic bacteria in a model fruit juice system. Three different strains of probiotic bacteria were used in this study: HOWARU Lactobacillus rhamnosus HN001, HOWARU Bifidobacterium lactis HN001, and Lactobacillus paracasei LPC 37. The probiotic bacteria were inoculated into model juice with various vitamins and antioxidants, namely white grape seed extract, green tea extract, vitamin B2, vitamin B3, vitamin B6, vitamin C, and vitamin E. The model juice without any additives was used as a control. Their viability was assessed on a weekly basis using plate count method. The model juice was made with sucrose, sodium citrate, citric acid powder, and distilled water and was pasteurized before use. Our findings showed that probiotic bacteria did not survive well in the harsh environment of the model fruit juice. However, the model juice containing vitamin C, grape extract, and green tea extract showed better survival of probiotic bacteria. The model juice containing grape seed extract, green tea extract, and vitamin C had the same initial population of 8.32 log CFU/mL, and at the end of the 6-wk storage period it had an average viability of 4.29 log CFU/mL, 7.41 log CFU/mL, and 6.44 log CFU/mL, respectively. Juices containing all other ingredients tested had viable counts of <10 CFU/mL at the end of the 6-wk storage period.


Assuntos
Antioxidantes , Bebidas/microbiologia , Bifidobacterium/crescimento & desenvolvimento , Frutas/microbiologia , Lactobacillus/crescimento & desenvolvimento , Probióticos , Vitaminas , Ácido Ascórbico , Contagem de Colônia Microbiana , Manipulação de Alimentos/métodos , Microbiologia de Alimentos , Extrato de Sementes de Uva , Viabilidade Microbiana , Niacinamida , Extratos Vegetais , Riboflavina , Chá/microbiologia , Vitamina B 6 , Vitamina E
13.
J Clin Microbiol ; 46(12): 4068-70, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18842939

RESUMO

Endometrial biopsy samples derived from 393 patients with assorted gynecological complaints were investigated for mycobacterial infection. By employment of four different techniques, mycobacterial pathogens were detected irrespective of the nature/type of clinical complaint. Mycobacterium tuberculosis was the predominant pathogen detected among the samples investigated.


Assuntos
Endometrite/complicações , Infertilidade/etiologia , Tuberculose/complicações , Endometrite/epidemiologia , Endométrio/microbiologia , Endométrio/patologia , Feminino , Humanos , Índia/epidemiologia , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/epidemiologia
14.
Leukemia ; 22(6): 1200-6, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18401416

RESUMO

Dasatinib, a potent inhibitor of BCR-ABL in vitro, is effective for patients with chronic myelogenous leukemia (CML) resistant or intolerant to imatinib. To provide a more definitive assessment of dasatinib in chronic-phase (CP)-CML, we report extended follow-up of a phase II trial, presenting data for the entire patient cohort (N=387). Dasatinib (70 mg) twice daily was administered to patients with imatinib-resistant or -intolerant CP-CML. With median follow-up of 15.2 months (treatment duration, <1-18.4 months), a complete hematologic response was attained or maintained in 91% of patients. A major cytogenetic response (MCyR) was attained or maintained by 59% (52% imatinib resistant and 80% imatinib intolerant); this was complete in 49% of patients (40% imatinib resistant and 75% imatinib intolerant). Of 230 patients achieving an MCyR, 7 experienced disease progression. Fifteen-month progression-free survival was 90% while overall survival was 96%. Grade 3/4 thrombocytopenia and neutropenia were reported in 48 and 49% of patients, respectively. Non-hematologic toxicity (any grade) consisted primarily of diarrhea (37%), headache (32%), fatigue (31%), dyspnea (30%) and pleural effusion (27%). Pleural effusions were classified as grade 3 in 6% of reported events, with no incidence of grade 4. Dasatinib is associated with high response rates in patients with imatinib-resistant or -intolerant CP-CML.


Assuntos
Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mieloide de Fase Crônica/tratamento farmacológico , Piperazinas/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/uso terapêutico , Tiazóis/uso terapêutico , Adulto , Idoso , Benzamidas , Dasatinibe , Intervalo Livre de Doença , Feminino , Seguimentos , Proteínas de Fusão bcr-abl/genética , Humanos , Mesilato de Imatinib , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Leucemia Mieloide de Fase Crônica/genética , Leucemia Mieloide de Fase Crônica/patologia , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Mutação/genética , Proteínas Tirosina Quinases/antagonistas & inibidores , Taxa de Sobrevida , Resultado do Tratamento
17.
J Dairy Sci ; 81(11): 2804-16, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9839222

RESUMO

The present investigation studied the effects of cysteine, whey powder, whey protein concentrate, acid casein hydrolysates, or tryptone on the viability of Streptococcus thermophilus, Lactobacillus acidophilus, and bifidobacteria. Changes in pH, titratable acidity, redox potential, and viability of bacteria were monitored during 24 h of fermentation and refrigerated storage (4 degrees C) of yogurt for 35 d. The incubation time that was needed to reach pH 4.5 was considerably affected by the added ingredients. Also, the drop in pH or the increase in acidity and redox potential was dependent on the added ingredients. The addition of cysteine, whey protein concentrate, acid casein hydrolysates, or tryptone improved the viability of bifidobacteria to a variable extent, but whey powder failed to improve their viability. The morphology of S. thermophilus, as shown by electron microscopy, was affected by cysteine at 500 mg/L, possibly as a result of reduced redox potential. Sodium dodecyl sulfate-PAGE and amino acid analyses suggested that the nitrogen source in the form of peptides and amino acids improved the viability of bifidobacteria in yogurt made with a commercial ABT (Lactobacillus acidophilus, bifidobacteria, and Streptococcus thermophilus) starter culture, which showed a dramatic decline in the counts of this organism in previous studies.


Assuntos
Bactérias/crescimento & desenvolvimento , Probióticos , Iogurte/microbiologia , Bifidobacterium/crescimento & desenvolvimento , Caseínas/administração & dosagem , Temperatura Baixa , Contagem de Colônia Microbiana , Cisteína/administração & dosagem , Eletroforese em Gel de Poliacrilamida , Fermentação , Concentração de Íons de Hidrogênio , Lactobacillus acidophilus/crescimento & desenvolvimento , Microscopia Eletrônica , Proteínas do Leite/administração & dosagem , Oxirredução , Peptonas/administração & dosagem , Hidrolisados de Proteína/administração & dosagem , Streptococcus/crescimento & desenvolvimento , Proteínas do Soro do Leite
18.
J Virol ; 69(10): 6304-13, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7666531

RESUMO

Human immunodeficiency virus type 1 (HIV-1) infection causes profound immunological defects in afflicted patients. Various mechanisms have been proposed to account for the immune dysfunction in AIDS ultimately leading to loss of CD4+ T cells, including HIV-1 envelope-mediated syncytium formation, apoptosis, and cytokine modulation. Here we present results which suggest a novel hypothesis for T-cell dysfunction. We show, using HIV-1 bearing a novel cell surface reporter gene, that infected cells are unable to progress normally through the cell cycle and became arrested in the G2 + M phase. Furthermore, we identify the HIV-1 vpr gene product as being both necessary and sufficient for eliciting this cell cycle arrest. Cell cycle arrest induced by Vpr correlates with an increase in the hyperphosphorylated (inactive) form of the cyclin-dependent serine/threonine kinase CDC2, consistent with an arrest of cells at the boundary of G2 and M.


Assuntos
Ciclo Celular , Genes vpr , HIV-1/genética , Linfócitos T/citologia , Linfócitos T/virologia , Síndrome da Imunodeficiência Adquirida/imunologia , Sequência de Aminoácidos , Contagem de Linfócito CD4 , DNA/análise , Fase G2 , Produtos do Gene vpr/biossíntese , Produtos do Gene vpr/química , HIV-1/patogenicidade , Células HeLa , Humanos , Linfoma não Hodgkin , Mitose , Dados de Sequência Molecular , Mutagênese , Fases de Leitura Aberta , Linfócitos T/patologia , Células Tumorais Cultivadas , Produtos do Gene vpr do Vírus da Imunodeficiência Humana
19.
Gene Ther ; 2(6): 369-76, 1995 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7584111

RESUMO

We describe a novel reporter molecule, the murine surface antigen Thy-1, useful for immunoselection and detection of retrovirus-mediated transduction by flow cytometry. A cDNA encoding the murine thy-1 gene was isolated, and cell surface expression of its gene product was demonstrated. The Thy-1 glycoprotein was tested as a cell surface reporter molecule in the context of replication-defective and -competent retroviruses. Cells transduced via murine retroviral vectors carrying the thy-1 and the neomycin phosphotransferase genes express Thy-1 glycoprotein on their surfaces. The Thy-1 marker is potentially useful in gene transfer protocols because selection of transduced cells can be achieved by immunoselection with anti-Thy-1 antibodies shortly after infection with the retroviral vector. In addition, a human immunodeficiency virus type 1 (HIV-1) recombinant expressing Thy-1 is described, which is replication-competent and syncytium-inducing in human peripheral blood mononuclear cells (PBMCs) and immortalized CD4-positive cell lines. Cells infected with this HIV-1 recombinant express Thy-1 on their surfaces and can be detected and purified by fluorescence-activated cell sorting (FACS). Because of these properties, retroviruses expressing this genetic marker can be useful for studies in gene therapy and of the retroviral life-cycle.


Assuntos
DNA Viral/biossíntese , HIV-1/genética , Linfócitos/virologia , Antígenos Thy-1/biossíntese , Transfecção , Animais , Sequência de Bases , Linfócitos T CD4-Positivos/virologia , Linhagem Celular , Células Cultivadas , Chlorocebus aethiops , Primers do DNA , DNA Viral/análise , Citometria de Fluxo , Expressão Gênica , Células Gigantes , Proteína do Núcleo p24 do HIV/biossíntese , Repetição Terminal Longa de HIV , Humanos , Canamicina Quinase , Camundongos , Dados de Sequência Molecular , Fosfotransferases (Aceptor do Grupo Álcool)/biossíntese , Reação em Cadeia da Polimerase , Antígenos Thy-1/análise , Células Tumorais Cultivadas
20.
Mol Cell Biol ; 11(4): 1854-60, 1991 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1900918

RESUMO

The t(9;22) Philadelphia chromosome translocation fuses 5' regulatory and coding sequences of the BCR gene to the c-ABL proto-oncogene. This results in the formation of hybrid BCR-ABL mRNAs and proteins. The shift in ABL transcriptional control to the BCR promoter may play a role in cellular transformation mediated by this rearrangement. We have functionally localized the BCR promoter to a region 1 kb 5' of BCR exon 1 coding sequences by using a chloramphenicol acetyltransferase reporter gene assay. Nucleotide sequence analysis of this region revealed many consensus binding sequences for transcription factor SP1 as well as two potential CCAAT box binding factor sites and one putative helix-loop-helix transcription factor binding site. No TATA-like or "initiator" element sequences were found. Because of low steady-state levels of BCR mRNA and the high GC content (78%) of the promoter region, definitive mapping of transcription start sites required artificial amplification of BCR promoter-directed transcripts. Overexpression from the BCR promoter in a COS cell system was effective in demonstrating multiple transcription initiation sites. In order to assess the effects of chromosomal translocation on the transcriptional control of the BCR gene, we determined S1 nuclease protection patterns of poly(A)+ RNA from tumor cell lines. No differences were observed in the locations and levels of BCR transcription initiation sites between those lines that harbored the t(9;22) translocation and those that did not. This demonstrates that BCR promoter function remains intact in spite of genomic rearrangement. The BCR promoter is structurally similar to the ABL promoters. Together, this suggests that the structural fusion of BCR-ABL and not its transcriptional deregulation is primarily responsible for the transforming effect of the t(9;22) translocation.


Assuntos
Cromossomo Filadélfia , Regiões Promotoras Genéticas , Sequência de Aminoácidos , Animais , Sequência de Bases , Northern Blotting , Southern Blotting , Linhagem Celular , Transformação Celular Neoplásica , Éxons , Genes , Genes abl , Haplorrinos , Humanos , Dados de Sequência Molecular , Proto-Oncogene Mas , Mapeamento por Restrição , Transcrição Gênica , Células Tumorais Cultivadas
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