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1.
Appl Opt ; 62(18): 4949-4957, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37707273

RESUMO

Endoscopic optical diagnostics for IC engines offer the advantage of retaining the full operating range and thermal properties of the production engine. The custom-designed modular hybrid UV endoscope system is optimized for application in IC engines.; however, its hybrid refractive/diffractive relay element is expensive and has a narrow operating wavelength range. To make the endoscopic imaging more universally applicable, the hybrid relay element of the mentioned endoscope system was replaced by commercial UV camera lenses, and several combinations were characterized in terms of resolution, brightness, and chromatic aberration. With an unintensified CCD camera, endoscope systems using commercial camera lenses had better resolution at investigated magnifications of 0.5 and 1. However, with an intensified camera, the system with the hybrid relay lens had the best overall performance in its design wavelength range. Selected imaging systems were used in a spark-ignition engine to image O H ∗-chemiluminescence, with results consistent with those from bench-top characterization.

2.
Psychol Med ; 49(16): 2772-2780, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-30606279

RESUMO

BACKGROUND: Studies investigating the underlying mechanisms of hallucinations in patients with schizophrenia suggest that an imbalance in top-down expectations v. bottom-up processing underlies these errors in perception. This study evaluates this hypothesis by testing if individuals drawn from the general population who have had auditory hallucinations (AH) have more misperceptions in auditory language perception than those who have never hallucinated. METHODS: We used an online survey to determine the presence of hallucinations. Participants filled out the Questionnaire for Psychotic Experiences and participated in an auditory verbal recognition task to assess both correct perceptions (hits) and misperceptions (false alarms). A hearing test was performed to screen for hearing problems. RESULTS: A total of 5115 individuals from the general Dutch population participated in this study. Participants who reported AH in the week preceding the test had a higher false alarm rate in their auditory perception compared with those without such (recent) experiences. The more recent the AH were experienced, the more mistakes participants made. While the presence of verbal AH (AVH) was predictive for false alarm rate in auditory language perception, the presence of non-verbal or visual hallucinations were not. CONCLUSIONS: The presence of AVH predicted false alarm rate in auditory language perception, whereas the presence of non-verbal auditory or visual hallucinations was not, suggesting that enhanced top-down processing does not transfer across modalities. More false alarms were observed in participants who reported more recent AVHs. This is in line with models of enhanced influence of top-down expectations in persons who hallucinate.


Assuntos
Alucinações/diagnóstico , Alucinações/psicologia , Idioma , Semântica , Percepção da Fala , Estimulação Acústica/métodos , Adulto , Análise de Variância , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Distorção da Percepção , Inquéritos e Questionários , Adulto Jovem
3.
HIV Med ; 19(6): 376-385, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29441669

RESUMO

OBJECTIVES: The aim of the study was to investigate the hypothesis of accelerated cognitive ageing in HIV-positive individuals using longitudinal assessment of cognitive performance and quantitative magnetic resonance imaging (MRI). METHODS: We assessed a broad cognitive battery and quantitative MRI metrics [voxel-based morphometry (VBM) and diffusion tensor imaging (DTI)] in asymptomatic HIV-positive men who have sex with men (15 aged 20-40 years and 15 aged ≥ 50 years), and HIV-seronegative matched controls (nine aged 20-40 years and 16 aged ≥ 50 years). RESULTS: Being HIV positive was associated with greater decreases in executive function and global cognition. Additionally, using DTI, we found that the HIV-positive group had a greater increase in mean diffusivity, but we did not find group differences in volume change using VBM. With respect to the HIV status by age group interaction, this was statistically significant for change in global cognition, with older HIV-positive individuals showing greater global cognitive decline, but there were no significant interaction effects on other measures. Lastly, change in cognitive performance was correlated with change in the DTI measures, and this effect was stronger for the HIV-positive participants. CONCLUSIONS: In the present study, we found some evidence for accelerated ageing in HIV-positive individuals, with a statistically significant HIV status by age group interaction in global cognition, although this interaction could not be explained by the imaging findings. Moreover, we also found that change in cognitive performance was correlated with change in the DTI measures, and this effect was stronger for the HIV-positive participants. This will need replication in larger studies using a similarly lengthy follow-up period.


Assuntos
Envelhecimento/patologia , Disfunção Cognitiva/fisiopatologia , Infecções por HIV/fisiopatologia , Infecções por HIV/psicologia , Imageamento por Ressonância Magnética , Neuroimagem , Adulto , Envelhecimento/imunologia , Cognição , Disfunção Cognitiva/virologia , Seguimentos , Infecções por HIV/imunologia , Homossexualidade Masculina , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Fatores de Tempo , Adulto Jovem
4.
Nat Genet ; 8(1): 27-32, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7726912

RESUMO

The MTS1 gene on chromosome 9p21 encodes the p16 inhibitor of cyclinD/Cdk-4 complexes, and is deleted or mutated in a variety of tumour types. We found allelic deletions of 9p21-p22 in 85% of pancreatic adenocarcinomas. Analysis of MTS1 in pancreatic carcinomas (27 xenografts and 10 cell lines) showed homozygous deletions in 15 (41%) and sequence changes in 14 (38%). These included eight point mutations (four nonsense, two missense and two splice site mutations) and six deletions/insertions, all accompanied by loss of the wild-type allele. Sequencing of MTS1 from primary tumours confirmed the mutations. Coexistent inactivations of both MTS1 and p53 was common and suggests that abnormal regulation of cyclin-dependent kinases may play an important role in the biology of pancreatic carcinoma.


Assuntos
Adenocarcinoma/genética , Proteínas de Transporte/genética , Neoplasias Pancreáticas/genética , Sequência de Bases , Deleção Cromossômica , Cromossomos Humanos Par 9 , Inibidor p16 de Quinase Dependente de Ciclina , Deleção de Genes , Genes p53 , Humanos , Dados de Sequência Molecular , Mutação , Células Tumorais Cultivadas
5.
Nat Genet ; 13(3): 343-6, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8673134

RESUMO

Chromosome deletions are the most common genetic events observed in cancer. These deletions are generally thought to reflect the existence of a tumour suppressor gene within the lost region. However, when the lost region does not precisely coincide with a hereditary cancer locus, identification of the putative tumour suppressor gene (target of the deletion) can be problematic. For example, previous studies have demonstrated that chromosome 18q is lost in over 60% of colorectal as well as in other cancers, but the lost region could not be precisely determined. Here we present a rigorous strategy for mapping and evaluating allelic deletions in sporadic tumours, and apply it to the evaluation of chromosome 18 in colorectal cancers. Using this approach, we define a minimally lost region (MLR) on chromosome 18q21, which contains at least two candidate tumour suppressor genes, DPC4 and DCC. The analysis further suggested genetic heterogeneity, with DPC4 the deletion target in up to a third of the cases and DCC or a neighbouring gene the target in the remaining tumours.


Assuntos
Cromossomos Humanos Par 18 , Neoplasias Colorretais/genética , Proteínas de Ligação a DNA , Genes Supressores de Tumor , Transativadores , Proteínas Supressoras de Tumor , Alelos , Animais , Sequência de Bases , Moléculas de Adesão Celular/genética , Mapeamento Cromossômico , Receptor DCC , Análise Mutacional de DNA , Marcadores Genéticos , Humanos , Hibridização in Situ Fluorescente , Camundongos , Camundongos Nus , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/métodos , Proteínas/genética , Receptores de Superfície Celular , Proteína Smad4 , Transplante Heterólogo , Células Tumorais Cultivadas
6.
Artigo em Alemão | MEDLINE | ID: mdl-23455560

RESUMO

"Dynamic", "complexity", and "diversity" are terms that best describe the challenges in the workplace resulting from the changing nature of work. These changes should conform to the criteria of human-related work design. However, the number of pensions for reduced earning capacity and the number of unfit for work days caused by psychic disorders are rising. Affective disorders, including depression, are the largest group. Depression represents a long-term consequence of work demands. Empirical results confirm a significant relationship between depression and the objective existing as well as the subjective perceived workload conditions. Burn-out as a further long-term consequence depends inter alia on the design of the physical work demands, the environmental conditions, the psychosocial conditions, and the transparency of the decision and information processes in a company. Additionally, empirical results show that the short-term consequences of work demands, i.e., fatigue, satiation, and monotony correlate with the burn-out components of exhaustion and alienation from work. Furthermore, using restructuring as an example, it is demonstrated that the changes in work that accompany modifications in the working world also have other health-related consequences.


Assuntos
Nível de Saúde , Transtornos Mentais/epidemiologia , Doenças Profissionais/epidemiologia , Desemprego/estatística & dados numéricos , Carga de Trabalho/estatística & dados numéricos , Emprego , Alemanha/epidemiologia , Humanos , Prevalência , Psicologia , Desemprego/tendências , Local de Trabalho
8.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 3): o777, 2012 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-22412651

RESUMO

In the title compound, C(15)H(11)NO(2), two C-H⋯O hydrogen bonds are observed in the crystal structure, as well as π-π stacking with a centroid-centroid distance of 3.623 (2) Å. The planarity of the two ring systems is illustrated by very small deviations of all the atoms from these planes [largest deviations = 0.003 (3) and 0.010 (3) Šfor the phenyl and fused-benzene rings, respectively]. The dihedral angle between these two planes is 77.65 (9)°.

9.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 3): o914, 2012 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-22412758

RESUMO

In the crystal of the title hydrated molecular salt, C(6)H(10)N(2) (2+)·SO(4) (2-)·H(2)O, N-H⋯O and O-H⋯O hydrogen bonds link the mol-ecules into layers parallel to the ab plane. C-H⋯O hydrogen bonds are observed both within these layers and between mol-ecules and ions in adjacent layers.

10.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 12): o3472, 2012 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-23476281

RESUMO

THE TITLE COMPOUND [SYSTEMATIC NAME: 5-(trifluoro-meth-oxy)-1H-indole-2,3-dione], C9H4F3NO3, crystallized with two mol-ecules in the asymmetric unit. Inter-molecular N-H⋯O hydrogen bonds link the mol-ecules to form layers parallel to the ab plane. In addition, π-π stacking inter-actions are observed with a centroid-centroid distance of 3.721 (1) Å. The near planarity of the two isatin ring systems is illustrated by by the maximum deviations of 0.023 (1) and 0.025 (1) Šfor the N atom in each case.

11.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 11): m1359-60, 2012 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-23284342

RESUMO

In the title compound, [Re(2)(CH(3)O)(2)(CO)(6)(C(4)H(6)N(3)O)], the two Re(I) atoms are linked by a methoxo and methanolato bridge, as well as by a creatinine ligand that coordinates in a bidentate fashion. Three fac-carbonyl ligands occupy the rest of the slightly distorted octa-hedral geometry around each Re(I) atom. The bridging methanolato and methoxo ligands are bent out of the Re(2)O(2) plane by 49.2 (4) and 47.8 (3)° respectively. This is normally associated with a methanolato-bridging-type coordination rather that the more planar methoxo-type bridging. Furthermore, the creatinine bridging molecule is very slightly distorted from the Re(2)N(2)C plane, indicating that the pyrazolo N atom bonded to the Rh(I) atom is not protonated. Charge balance can thus only be attained if one assumes a positional disorder for the methanolato/methoxo H atom. All attempts to locate disordered protons around these O atoms were unsuccessful. Four hydrogen bonds, one N-H⋯O and three C-H⋯O, are observed in the structure. The mol-ecules pack in a head-to-head and tail-to-tail fashion when viewed along the c axis, in alternating columns.

12.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 11): o3235-6, 2012 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-23284535

RESUMO

The title compound, C(10)H(15)NO(2), crystallized with three mol-ecules in the asymmetric unit. These three mol-ecules are quite similar except for slight differences in the torsion angles of the substituents on the ring. The isopropyl C-C-N-C torsion angles (towards the carbon next to the ethyl bound carbon), for example, are -150.63 (11), -126.77 (13) and -138.76 (11)° for mol-ecules A, B and C, respectively, and the C-C-C-N torsion angles involving the ethyl C atoms are 102.90 (13), 87.81 (14) and 86.47 (13)°. The main difference between the three mol-ecules lies in the way they are arranged in the solid-state structure. All three mol-ecules form dimers that are connected through strong O-H⋯O hydrogen bonds with R(2) (2)(10) graph-set motifs. The symmetry of the dimers formed does however differ between mol-ecules. Mol-ecules B connect with each other to form inversion dimers. Mol-ecules A and C, on the other hand, form dimers with local twofold symmetry, but the two mol-ecules are crystallographically distinct. The B and C molecules are linked to themselves and to each other via C-H⋯O hydrogen bonds. This results in the formation of a three-dimensional network structure.

13.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 9): m1208-9, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-22969493

RESUMO

The title compound, [Re(4)(µ(3)-OH)(4)(CO)(12)]·4C(5)H(5)N, crystallizes with one tetranuclear rhenium(I) cubane-like molecule and four pyridine mol-ecules in the asymmetric unit. The coordination environment of each Re(I) atom is distorted octahedral. Four intra-molecular O-H⋯N and four inter-molecular C-H⋯O hydrogen-bond inter-actions are observed. Relatively strong hydrogen bonds are found between the hydrogen-bond donor (µ(3)-OH) and acceptor (basic N atom of pyridine), with N⋯O distances between 2.586 (10) and 2.628 (10) Å. Inter-cube distances of 9.873 (2) and 12.376 (3) Šare observed.

15.
Invest New Drugs ; 27(2): 166-72, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18696011

RESUMO

The purpose of this study was to evaluate the efficacy (progression free survival (PFS) and response rate) and safety of vinorelbine and trastuzumab combination chemotherapy in patients with HER2-overexpressing, metastatic breast cancer as a first line chemotherapy regimen. Patients with histologically confirmed, HER2-positive (immunohistochemistry (ICH) 3+, or 2+ and FISH+) metastatic breast cancer who had nor received prior vinorelbine or anti-HER2 therapy in the adjuvant setting, received at least eight weeks of vinorelbine i.v. (25 mg/g weekly) and trastuzumab (4 mg/kg on day 1 followed by 2 mg/kg weekly). Forty-one women from six participating centers were enrolled into the trial. The overall response rate, was 43.9% (18 of 41 patients), (CI 28-60.3%), 30% of patients were progression free after 1 year. Four patients reached complete remission, 14 partial remission and five had stable disease for at least 18 weeks. Six patients developed primary progression. 35 patients (85%) experienced progression after a median time of 235 days. Therapy was in general well-tolerated. There were two CTC grade 4 infusion syndromes and two patients experienced cardiotoxicity at least grade 2. This phase II trial of vinorelbine and trastuzumab demonstrated an effective and well-tolerated regimen with a favourable safety profile.


Assuntos
Adenocarcinoma/tratamento farmacológico , Anticorpos Monoclonais/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Genes erbB-2 , Vimblastina/análogos & derivados , Adenocarcinoma/patologia , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais Humanizados , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Intervalo Livre de Doença , Feminino , Humanos , Metástase Neoplásica , Trastuzumab , Vimblastina/administração & dosagem , Vimblastina/efeitos adversos , Vinorelbina
16.
Science ; 271(5247): 350-3, 1996 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-8553070

RESUMO

About 90 percent of human pancreatic carcinomas show allelic loss at chromosome 18q. To identify candidate tumor suppressor genes on 18q, a panel of pancreatic carcinomas were analyzed for convergent sites of homozygous deletion. Twenty-five of 84 tumors had homozygous deletions at 18q21.1, a site that excludes DCC (a candidate suppressor gene for colorectal cancer) and includes DPC4, a gene similar in sequence to a Drosophila melanogaster gene (Mad) implicated in a transforming growth factor-beta (TGF-beta)-like signaling pathway. Potentially inactivating mutations in DPC4 were identified in six of 27 pancreatic carcinomas that did not have homozygous deletions at 18q21.1. These results identify DPC4 as a candidate tumor suppressor gene whose inactivation may play a role in pancreatic and possibly other human cancers.


Assuntos
Cromossomos Humanos Par 18 , Proteínas de Ligação a DNA , Genes Supressores de Tumor , Neoplasias Pancreáticas/genética , Proteínas/genética , Transativadores , Alelos , Sequência de Aminoácidos , Animais , Sequência de Bases , Divisão Celular , Mapeamento Cromossômico , Deleção de Genes , Expressão Gênica , Marcadores Genéticos , Humanos , Camundongos , Dados de Sequência Molecular , Mutação , Transplante de Neoplasias , Neoplasias Pancreáticas/patologia , Proteínas/química , Proteínas/fisiologia , Transdução de Sinais , Proteína Smad4 , Fator de Crescimento Transformador beta/fisiologia , Transplante Heterólogo , Células Tumorais Cultivadas
17.
J Chromatogr A ; 1574: 122-129, 2018 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-30190080

RESUMO

A gas chromatographic method for the determination of volatile contaminants (halogenated solvents, benzene, toluene, ethyl-benzene, xylenes, styrene) and phenol in e-liquids was developed and validated with a working range of 0.01 (limit of quantification) to 0.5 mg/l, and variation coefficients between 2 and 14%. Selectivity performing MS/MS-detection was sufficient for all analytes except for phenol: e-liquids contain high amounts of aroma compounds in excess of 105 compared to phenol. A number of these compounds potentially interfere at the retention time of phenol, showing all masses (including daughter ions and transitions) of phenol. To allow the detection of phenol in this matrix, a novel approach of adding a polar molecule to the injection solvent was used, modulating the polarity of the column, and thus the retention time of phenol. By adding 3 µl/ml and 10 µl/ml of 1,2-propanediol the retention time of phenol was shifted by 0.06 and 0.11 min respectively, while interfering peaks have not been shifted. This allowed a reliable confirmation of the presence of phenol. The introduced approach is an easy way to generate an additional chromatographic dimension for confirmation purposes, not requiring additional equipment.


Assuntos
Técnicas de Química Analítica/métodos , Cromatografia Gasosa , Fenol/análise , Solventes/química , Fenol/química , Espectrometria de Massas em Tandem , Fatores de Tempo
18.
Crit Rev Oncol Hematol ; 64(1): 64-72, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17317205

RESUMO

This randomized phase 2 study explored the feasibility of delivering four to six cycles of the dose-intensified regimen FEC-100 (5-fluorouracil, epirubicin, and cyclophosphamide) to elderly patients with stage II-III breast cancer, using pegfilgrastim for neutrophil support. Sixty patients aged 65-77 years received single 6mg doses of pegfilgrastim on day 2 of FEC-100, either as primary prophylaxis (all cycles: PP), or as secondary prophylaxis (all cycles following a neutropenic event: SP). Neutropenic events (a composite endpoint that included grade 3 neutropenia+fever, grade 4 neutropenia, infectious complication requiring systemic anti-infectives and chemotherapy dose delay/reduction) occurred in 24/30 (80%) of the PP and 21/29 (72%) of the SP group in the first cycle. Most patients received all chemotherapy cycles at full dose on schedule (26/30 [87%] PP; 20/29 [69%] SP). These data indicate that delivery of FEC-100 is feasible with pegfilgrastim support in elderly breast cancer patients.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Neutropenia/prevenção & controle , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/toxicidade , Neoplasias da Mama/complicações , Ciclofosfamida/administração & dosagem , Ciclofosfamida/toxicidade , Epirubicina/administração & dosagem , Epirubicina/toxicidade , Feminino , Filgrastim , Fluoruracila/administração & dosagem , Fluoruracila/toxicidade , Fator Estimulador de Colônias de Granulócitos/toxicidade , Humanos , Neutropenia/induzido quimicamente , Infecções Oportunistas/induzido quimicamente , Polietilenoglicóis , Pré-Medicação , Proteínas Recombinantes , Resultado do Tratamento
19.
J Natl Cancer Inst ; 92(7): 564-9, 2000 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-10749912

RESUMO

BACKGROUND: Inherited mutations in the BRCA1 gene may be responsible for almost half of inherited breast carcinomas. However, somatic (acquired) mutations in BRCA1 have not been reported, despite frequent loss of heterozygosity (LOH or loss of one copy of the gene) at the BRCA1 locus and loss of BRCA1 protein in tumors. To address whether BRCA1 may be inactivated by pathways other than mutations in sporadic tumors, we analyzed the role of hypermethylation of the gene's promoter region. METHODS: Methylation patterns in the BRCA1 promoter were assessed in breast cancer cell lines, xenografts, and 215 primary breast and ovarian carcinomas by methylation-specific polymerase chain reaction (PCR). BRCA1 RNA expression was determined in cell lines and seven xenografts by reverse transcription-PCR. P values are two-sided. RESULTS: The BRCA1 promoter was found to be unmethylated in all normal tissues and cancer cell lines tested. However, BRCA1 promoter hypermethylation was present in two breast cancer xenografts, both of which had loss of the BRCA1 transcript. BRCA1 promoter hypermethylation was present in 11 (13%) of 84 unselected primary breast carcinomas. BRCA1 methylation was strikingly associated with the medullary (67% methylated; P =.0002 versus ductal) and mucinous (55% methylated; P =.0033 versus ductal) subtypes, which are overrepresented in BRCA1 families. In a second series of 66 ductal breast tumors informative for LOH, nine (20%) of 45 tumors with LOH had BRCA1 hypermethylation, while one (5%) of 21 without LOH was methylated (P =.15). In ovarian neoplasms, BRCA1 methylation was found only in tumors with LOH, four (31%) of 13 versus none of 18 without LOH (P =.02). The BRCA1 promoter was unmethylated in other tumor types. CONCLUSION: Silencing of the BRCA1 gene by promoter hypermethylation occurs in primary breast and ovarian carcinomas, especially in the presence of LOH and in specific histopathologic subgroups. These findings support a role for this tumor suppressor gene in sporadic breast and ovarian tumorigenesis.


Assuntos
Neoplasias da Mama/metabolismo , Genes BRCA1/genética , Perda de Heterozigosidade , Neoplasias Ovarianas/metabolismo , Regiões Promotoras Genéticas/genética , Neoplasias da Mama/genética , Carcinoma Ductal de Mama/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Metilação , Neoplasias Ovarianas/genética , RNA , RNA Neoplásico/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transplante Heterólogo , Células Tumorais Cultivadas
20.
Cancer Res ; 56(19): 4351-3, 1996 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-8813122

RESUMO

DPC4, a recently cloned gene located on 18q2l.l, is inactivated in almost one half of pancreatic adenocarcinomas. To determine whether DPC4 inactivation is involved in esophageal adenocarcinoma, we have analyzed aneuploid populations from biopsies of 35 patients with Barrett's esophagus who had premalignant epithelium, adenocarcinoma, or both. Sixteen of 35 patients (46%) had allelic loss at l8q21.1, including 7 patients who had only premalignant tissue present in their Barrett segment. In addition, three of four patients (75%) with l8q21.1 loss in their aneuploid populations had the allelic loss present in diploid cells. Mutational analysis of DPC4 did not reveal any inactivating alterations in the gene. These data indicate that allelic losses at l8q are selected during neoplastic progression in Barrett's esophagus, but the targeted gene remains to be identified.


Assuntos
Alelos , Esôfago de Barrett/genética , Cromossomos Humanos Par 18/genética , Proteínas de Ligação a DNA , Neoplasias Esofágicas/genética , Lesões Pré-Cancerosas/genética , Transativadores/genética , Aneuploidia , Esôfago de Barrett/patologia , Análise Mutacional de DNA , Progressão da Doença , Neoplasias Esofágicas/patologia , Humanos , Lesões Pré-Cancerosas/patologia , Deleção de Sequência , Proteína Smad4
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