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1.
Psychooncology ; 25(10): 1168-1174, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27309861

RESUMO

OBJECTIVE: Inequalities exist in colorectal cancer (CRC) screening uptake, with people from lower socioeconomic status backgrounds less likely to participate. Identifying the facilitators and barriers to screening uptake is important to addressing screening disparities. We pooled data from 2 trials to examine educational differences in psychological constructs related to guaiac fecal occult blood testing. METHODS: Patients (n = 8576) registered at 7 general practices in England, within 15 years of the eligible age range for screening (45-59.5 years), were invited to complete a questionnaire. Measures included perceived barriers (emotional and practical) and benefits of screening, screening intentions, and participant characteristics including education. RESULTS: After data pooling, 2181 responses were included. People with high school education or no formal education reported higher emotional and practical barriers and were less likely to definitely intend to participate in screening, compared with university graduates in analyses controlling for study arm and participant characteristics. The belief that one would worry more about CRC after screening and concerns about tempting fate were strongly negatively associated with education. In a model including education and participant characteristics, respondents with low emotional barriers, low practical barriers, and high perceived benefits were more likely to definitely intend to take part in screening. CONCLUSIONS: In this analysis of adults approaching the CRC screening age, there was a consistent effect of education on perceived barriers toward guaiac fecal occult blood testing, which could affect screening decision making. Interventions should target specific barriers to reduce educational disparities in screening uptake and avoid exacerbating inequalities in CRC mortality.


Assuntos
Detecção Precoce de Câncer/psicologia , Intenção , Aceitação pelo Paciente de Cuidados de Saúde , Percepção , Fatores Socioeconômicos , Idoso , Neoplasias Colorretais/psicologia , Detecção Precoce de Câncer/estatística & dados numéricos , Inglaterra , Feminino , Humanos , Renda , Masculino , Programas de Rastreamento/psicologia , Pessoa de Meia-Idade , Motivação , Sangue Oculto , Inquéritos e Questionários
2.
Anal Chim Acta ; 883: 99-108, 2015 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-26088782

RESUMO

Field experiments were devised to mimic the entrapment conditions under the rubble of collapsed buildings aiming to investigate the evolution of volatile organic compounds (VOCs) during the early dead body decomposition stage. Three pig carcasses were placed inside concrete tunnels of a search and rescue (SAR) operational field terrain for simulating the entrapment environment after a building collapse. The experimental campaign employed both laboratory and on-site analytical methods running in parallel. The current work focuses only on the results of the laboratory method using thermal desorption coupled to comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (TD-GC×GC-TOF MS). The flow-modulated TD-GC×GC-TOF MS provided enhanced separation of the VOC profile and served as a reference method for the evaluation of the on-site analytical methods in the current experimental campaign. Bespoke software was used to deconvolve the VOC profile to extract as much information as possible into peak lists. In total, 288 unique VOCs were identified (i.e., not found in blank samples). The majority were aliphatics (172), aromatics (25) and nitrogen compounds (19), followed by ketones (17), esters (13), alcohols (12), aldehydes (11), sulfur (9), miscellaneous (8) and acid compounds (2). The TD-GC×GC-TOF MS proved to be a sensitive and powerful system for resolving the chemical puzzle of above-ground "scent of death".


Assuntos
Medicina Legal , Cromatografia Gasosa-Espectrometria de Massas/instrumentação , Mudanças Depois da Morte , Compostos Orgânicos Voláteis/análise , Animais , Desastres , Desenho de Equipamento , Medicina Legal/instrumentação , Medicina Legal/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Colapso Estrutural , Suínos
3.
Cancer Chemother Pharmacol ; 74(6): 1191-8, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25257509

RESUMO

PURPOSE: This phase I study endeavored to estimate the maximum tolerated dose and describe the dose-limiting toxicities (DLTs) of oral irinotecan with gefitinib in children with refractory solid tumors. METHODS: Oral irinotecan was administered on days 1-5 and 8-12 with oral gefitinib (fixed dose, 150 mg/m(2)/day) on days 1-12 of a 21-day course. The escalation with overdose control method guided irinotecan dose escalation (7 dose levels, range 5-40 mg/m(2)/day). RESULTS: Sixteen of 19 patients were evaluable, with serial pharmacokinetic studies in ten patients. Diagnoses included osteosarcoma (N = 5), neuroblastoma (N = 3), sarcoma (N = 3), and others (N = 5). Patients received a median of two courses (range 1-20), with at least two patients treated on dose levels 2-7. Three patients had five DLTs; the most common being metabolic (hypokalemia, N = 2 and hypophosphatemia, N = 1) at dose levels two (10 mg/m(2)) and four (20 mg/m(2)). One patient experienced grade 3 diarrhea (40 mg/m(2)). Irinotecan bioavailability was 2.5-fold higher when co-administered with gefitinib, while the conversion rate of irinotecan to SN-38 lactone was unaffected. The study closed due to poor accrual before evaluation of the next recommended irinotecan dose level (35 mg/m(2)). Of 11 patients receiving at least two courses of therapy, three had stable disease lasting two to four courses and one patient maintained a complete response through 18 courses. CONCLUSIONS: The combination of oral gefitinib and irinotecan has acceptable toxicity and anti-tumor activity in pediatric patients with refractory solid tumors. Pharmacokinetic analysis confirms that co-administration of gefitinib increases irinotecan bioavailability leading to an increased SN-38 lactone systemic exposure.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neoplasias/tratamento farmacológico , Administração Oral , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Disponibilidade Biológica , Camptotecina/administração & dosagem , Camptotecina/análogos & derivados , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Interações Medicamentosas , Feminino , Gefitinibe , Humanos , Irinotecano , Masculino , Dose Máxima Tolerável , Neoplasias/patologia , Quinazolinas/administração & dosagem , Resultado do Tratamento , Adulto Jovem
4.
JRSM Short Rep ; 4(3): 19, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23560218

RESUMO

OBJECTIVES: That health is now global is increasingly accepted. However, a 'mismatch between present professional competencies and the requirements of an increasingly interdependent world' has been identified. Postgraduate training should take account of the increasingly global nature of health; this paper examines the extent to which they currently do. DESIGN: Trainees across 11 medical specialties reviewed the content of their postgraduate curriculum. SETTING: Not relevant. PARTCIPANTS: None. MAIN OUTCOME MEASURES: Competencies were coded as 'UK' (statement only relevant to UK work), 'global' (statement with an explicit reference to aspects of health outside the UK) or generic (relevant both to the UK and international settings). RESULTS: Six of the 11 curricula reviewed contained global health competencies. These covered the global burden or determinants of disease and appropriate policy responses. Only one College required trainees to 'be aware of the World Health Organization', or 'know the local, national and international structures for health care'. These cross-cutting competencies have applicability to all specialties. All 11 curricula contained generic competencies where a global health perspective and/or experience could be advantageous, e.g. caring for migrant or culturally different patients. CONCLUSION: Trainees in all specialties should achieve a minimum requirement of global health awareness. This can be achieved through a small number of common competencies that are consistent across core curricula. These should lead on from equivalent undergraduate competencies. Addressing the current gap in the global health content of postgraduate medical curricula will ensure that the UK has health professionals that are trained to meet the health challenges of the future.

5.
Phytopathology ; 103(3): 245-54, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23113546

RESUMO

This study investigated how the timing of application of the biofungicide Serenade (Bacillus subtilis QST713) or it components (product filtrate and bacterial cell suspension) influenced infection of canola by Plasmodiophora brassicae under controlled conditions. The biofungicide and its components were applied as a soil drench at 5% concentration (vol/vol or equivalent CFU) to a planting mix infested with P. brassicae at seeding or at transplanting 7 or 14 days after seeding (DAS) to target primary and secondary zoospores of P. brassicae. Quantitative polymerase chain reaction (qPCR) was used to assess root colonization by B. subtilis as well as P. brassicae. The biofungicide was consistently more effective than the individual components in reducing infection by P. brassicae. Two applications were more effective than one, with the biofungicide suppressing infection completely and the individual components reducing clubroot severity by 62 to 83%. The biofungicide also reduced genomic DNA of P. brassicae in canola roots by 26 to 99% at 7 and 14 DAS, and the qPCR results were strongly correlated with root hair infection (%) assessed at the same time (r = 0.84 to 0.95). qPCR was also used to quantify the transcript activity of nine host-defense-related genes in inoculated plants treated with Serenade at 14 DAS for potential induced resistance. Genes encoding the jasmonic acid (BnOPR2), ethylene (BnACO), and phenylpropanoid (BnOPCL and BnCCR) pathways were upregulated by 2.2- to 23-fold in plants treated with the biofungicide relative to control plants. This induced defense response was translocated to the foliage (determined based on the inhibition of infection by Leptosphaeria maculans). It is possible that antibiosis and induced resistance are involved in clubroot suppression by Serenade. Activity against the infection from both primary and secondary zoospores of P. brassicae may be required for maximum efficacy against clubroot.


Assuntos
Ascomicetos/patogenicidade , Bacillus subtilis/fisiologia , Brassica napus/microbiologia , Resistência à Doença , Doenças das Plantas/imunologia , Plasmodioforídeos/patogenicidade , Antibiose , Ascomicetos/fisiologia , Bacillus subtilis/crescimento & desenvolvimento , Biofilmes , Agentes de Controle Biológico , Brassica napus/imunologia , Brassica napus/parasitologia , Cotilédone/imunologia , Cotilédone/microbiologia , Cotilédone/parasitologia , DNA Bacteriano/genética , DNA de Plantas/genética , DNA de Protozoário/genética , Interações Hospedeiro-Patógeno , Doenças das Plantas/microbiologia , Doenças das Plantas/parasitologia , Folhas de Planta/imunologia , Folhas de Planta/microbiologia , Folhas de Planta/parasitologia , Raízes de Plantas/imunologia , Raízes de Plantas/microbiologia , Raízes de Plantas/parasitologia , Plasmodioforídeos/fisiologia , Reação em Cadeia da Polimerase em Tempo Real , Plântula/imunologia , Plântula/microbiologia , Plântula/parasitologia , Esporos de Protozoários , Fatores de Tempo
7.
J Chromatogr A ; 1253: 154-63, 2012 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-22818775

RESUMO

A dense non-aqueous phase liquid sample formed by release of coal tar into the environment was derivatised by trimethylsilylation using the reagent N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) and extracted in hexane using accelerated solvent extraction. This procedure enables comprehensive extraction of an extensive suite of organic compounds from tar, which has not previously been described. Comprehensive two dimensional gas chromatography coupled to time of flight mass spectrometry (GC×GC-TOFMS) was used for the analysis of the sample for concurrent evaluation of -OH functional group-containing compounds along with aliphatics, polycyclic aromatic hydrocarbons and other typical tar compounds normally determined via classic gas chromatography. Using statistically designed experiments, a range of conditions were tested for complete recovery of four different surrogates. The robustness and repeatability of the optimised derivatisation/extraction method was demonstrated. Finally, more than a hundred and fifty derivatised compounds were identified using mass spectra elucidation and GC×GC logical order of elution.


Assuntos
Alcatrão/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Compostos Orgânicos/química , Compostos de Trimetilsilil/química , Recuperação e Remediação Ambiental , Compostos Orgânicos/isolamento & purificação , Reprodutibilidade dos Testes
8.
Int J Lab Hematol ; 34(1): 98-101, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21707934

RESUMO

A 2-year-old girl presented to casualty with a right knee effusion after apparently minor trauma. Inflicted injury was suspected and full forensic coagulation studies were performed which revealed a mild deficiency of factor VIII. Screening of the exons and intron/exon boundaries of F8 gene indicated that the child appeared to be homozygous for the missense mutation c.5123G>A (p.Arg1708His) in exon 14 of the F8 gene. This mutation has been reported to be associated with mild haemophilia A. The possibility of hemizygosity had been masked by the test kit employed but referral to the genetics service and subsequent array CGH resulted in a diagnosis of Turner syndrome.


Assuntos
Hemofilia A/diagnóstico , Síndrome de Turner/diagnóstico , Pré-Escolar , Cromossomos Humanos X , Diagnóstico Diferencial , Éxons , Fator VIII/genética , Feminino , Hemizigoto , Hemofilia A/complicações , Hemofilia A/genética , Homozigoto , Humanos , Traumatismos do Joelho/diagnóstico , Mutação , Síndrome de Turner/complicações , Síndrome de Turner/genética
9.
Oncogenesis ; 1: e1, 2012 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-23552518

RESUMO

Most inherited TP53 mutations have been identified in individuals with a family cancer predisposition syndrome, in which the activity of p53 mutants is severely reduced. However, germline p53 mutants in children with 'sporadic' adrenocortical or choroid plexus tumors exhibit a wide range of functional activity. Here, we demonstrate the occurrence of a complex germline TP53 mutation in two unrelated families with different cancer phenotypes, neither fulfilling the classic criteria for Li-Fraumeni syndrome. The TP53 mutation consists of a duplication of 7 bp in exon 4, resulting in a frame shift and premature stop signal. Haplotype analysis indicated that the mutation arose independently in the two families. Analysis of the DNA secondary structure predicts the TP53 mutation occurred within a hairpin loop. Additional germline complex mutations occurring within the same region of exon 4 have been identified in the IARC database. Our findings suggest that certain TP53 regions are prone to intrinsic genetic alterations, possibly through defects in DNA replication or repair. Further, carriers of the same TP53 mutation can have diverse cancer profiles, illustrating the complexity of genetic counseling and risk prediction.

12.
Curr Pharm Des ; 13(17): 1751-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17584105

RESUMO

The aim of this chapter is to present and identify potential pharmacological targets in endothelial cell-monocyte interactions leading to vascular syndrome and involving inflammation, coagulation, vascular remodelling and thrombosis. Increasing evidence is indicating that endothelial cells play a key role in atherothombosis by their capacity to attract, bind and allow the extravasation of monocytes to sites of inflammation. Surface expression and/or activation of constituent cell adhesion molecules (for e.g. P-selectin, E-selectin, ICAM-1, and VCAM-1) on endothelial cells together with chemokines such as CXCL8 (IL-8), Platelet-activating factor (PAF), CCL2 and CCL5 (Table 1) allow the rolling, adhesion and extravasation of monocytes. This review focuses on pharmacological targets implicated in endothelial cells interactions with monocytes/macrophages in vascular disease states and on cutting edge genomic tools for the identification and characterization of such targets.


Assuntos
Doenças Cardiovasculares/metabolismo , Moléculas de Adesão Celular/metabolismo , Comunicação Celular , Quimiocinas/metabolismo , Células Endoteliais/metabolismo , Inflamação/metabolismo , Macrófagos/metabolismo , Monócitos/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Fármacos Cardiovasculares/farmacologia , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/fisiopatologia , Moléculas de Adesão Celular/genética , Comunicação Celular/efeitos dos fármacos , Quimiocinas/genética , Células Endoteliais/efeitos dos fármacos , Genômica/métodos , Humanos , Inflamação/genética , Inflamação/fisiopatologia , Molécula 1 de Adesão Intercelular/metabolismo , Macrófagos/efeitos dos fármacos , Glicoproteínas de Membrana/metabolismo , Monócitos/efeitos dos fármacos , Selectina-P/metabolismo , Fator de Ativação de Plaquetas/metabolismo , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Transdução de Sinais , Molécula 1 de Adesão de Célula Vascular/metabolismo
13.
Nucleic Acids Res ; 30(1): 239-41, 2002 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-11752304

RESUMO

The PRINTS database houses a collection of protein fingerprints. These may be used to make family and tentative functional assignments for uncharacterised sequences. The September 2001 release (version 32.0) includes 1600 fingerprints, encoding approximately 10 000 motifs, covering a range of globular and membrane proteins, modular polypeptides and so on. In addition to its continued steady growth, we report here its use as a source of annotation in the InterPro resource, and the use of its relational cousin, PRINTS-S, to model relationships between families, including those beyond the reach of conventional sequence analysis approaches. The database is accessible for BLAST, fingerprint and text searches at http://www.bioinf.man.ac.uk/dbbrowser/PRINTS/.


Assuntos
Bases de Dados de Proteínas , Evolução Molecular , Proteínas/genética , Motivos de Aminoácidos , Animais , Armazenamento e Recuperação da Informação , Internet , Proteínas/fisiologia , Alinhamento de Sequência
14.
Pediatr Hematol Oncol ; 18(2): 89-100, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11255738

RESUMO

Follicle-derived thyroid cancer is rare in the young. The authors examined a population with a low rate of radiation exposure and who were treated at a single institution. The records of 56 patients diagnosed before the age of 25 years were analyzed. The majority of patients presented with an asymptomatic thyroid mass. All patients were treated surgically and half received postoperative ablation with 131I. Recurrent disease was detected in 29%. The presence of local metastases at initial surgery was a predictor of recurrence. No patient presented with distant metastases and no patient died of thyroid cancer. Although radiation exposure remains a risk factor for thyroid cancer in the young, only a minority of patients with thyroid cancer have a known history of exposure. Patients who are diagnosed at a young age have a high rate of long-term recurrence, and should be followed closely throughout their lives.


Assuntos
Neoplasias da Glândula Tireoide/etiologia , Neoplasias da Glândula Tireoide/terapia , Adenocarcinoma Folicular/diagnóstico , Adenocarcinoma Folicular/etiologia , Adenocarcinoma Folicular/terapia , Adenocarcinoma Papilar/diagnóstico , Adenocarcinoma Papilar/etiologia , Adenocarcinoma Papilar/terapia , Adolescente , Adulto , Criança , Pré-Escolar , Terapia Combinada , Exposição Ambiental , Feminino , Humanos , Masculino , Neoplasias Induzidas por Radiação/diagnóstico , Neoplasias Induzidas por Radiação/etiologia , Neoplasias Induzidas por Radiação/terapia , Prognóstico , Recidiva , Estudos Retrospectivos , Neoplasias da Glândula Tireoide/diagnóstico
15.
Cancer Epidemiol Biomarkers Prev ; 9(11): 1223-32, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11097231

RESUMO

Pancreatic cancer is a highly fatal cancer with few identified risk factors. Increased risk of pancreatic cancer in tobacco smokers and among diabetic patients is well established, and some reports have suggested associations with coffee consumption and occupational exposure to organochlorines. At present, there is little information regarding the possible association of these risk factors with the known genetic alterations found in pancreatic cancers, such as activation of the K-ras oncogene and inactivation of the p53 tumor suppressor gene. Knowledge of such relationships may help to understand the molecular pathways of pancreatic tumorigenesis. We investigated the association between these molecular defects and risk factors for pancreatic cancer in 61 newly diagnosed patients identified through an ongoing study of pancreatic cancer in the San Francisco Bay Area. Interview information was obtained regarding environmental exposures, medical history, and demographic factors. Serum levels of dichlorodiphenyltrichloroethylene (DDE) and polychlorinated biphenyls were available on a subset of 24 patients. Tumor blocks were located from local hospitals and used for K-ras mutational analysis at codon 12 and for p53 protein immunohistochemistry. The molecular analyses were facilitated through the use of laser capture microdissection, which provides a reliable method to obtain almost pure populations of tumor cells. Mutations in K-ras codon 12 were found in 46 (75%) of 61 pancreatic cancers. A prior diagnosis of diabetes was significantly associated with K-ras negative tumors (P = 0.002, Fisher's exact test). The absence of this mutation was also associated with increased serum levels of DDE, although this association was not statistically significant (P = 0.16, Wilcoxon's test). There was no difference in polychlorinated biphenyl levels between the K-ras wild-type and mutant groups. Immunohistochemical staining for p53 protein did not differ by patient characteristics or clinical history, but significant associations were found with poor glandular differentiation (P = 0.002, chi2 trend test), severe nuclear atypia (P = 0.0007, chi2 trend test), and high tumor grade (P = 0.004, chi2 trend test). Our results are suggestive of the presence of K-ras codon 12 mutation-independent tumorigenesis pathways in patients with prior diabetes and possibly in patients with higher serum levels of DDE. Our results also support a role for the p53 tumor suppressor protein in the maintenance of genomic integrity.


Assuntos
Carcinógenos/efeitos adversos , Exposição Ambiental , Genes p53/genética , Genes ras/genética , Neoplasias Pancreáticas/genética , Idoso , Estudos de Casos e Controles , Análise Mutacional de DNA , Complicações do Diabetes , Diclorodifenil Dicloroetileno/efeitos adversos , Feminino , Humanos , Imuno-Histoquímica , Inseticidas/efeitos adversos , Masculino , Anamnese , Pessoa de Meia-Idade , Neoplasias Pancreáticas/etiologia , Fatores de Risco
16.
Pediatr Hematol Oncol ; 17(7): 591-5, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11033735

RESUMO

A case report is presented of an 8-year-old boy who underwent resection of a thyroglossal duct cyst to illustrate a rare, but significant, complication of a common clinical problem. Pathological examination revealed that it contained a papillary adenocarcinoma of the thyroid, presumably arising from ectopic glandular tissue in the cyst. Thyroglossal duct cysts are a common cause of midline neck masses in children. Occult thyroid carcinoma is a rare co-morbid finding. It infrequently leads to death, but thyroglossal duct cysts may also contain the only functioning, albeit ectopic, thyroid tissue. Patients with clinical thyroglossal duct cysts should be carefully evaluated preoperatively for the presence of tumor and other functioning thyroid tissue prior to excision of the cyst.


Assuntos
Adenocarcinoma Papilar/patologia , Cisto Tireoglosso/patologia , Neoplasias da Glândula Tireoide/patologia , Adenocarcinoma Papilar/cirurgia , Criança , Humanos , Masculino , Cisto Tireoglosso/cirurgia , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia
17.
Thromb Res ; 94(4): 235-40, 1999 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-10336239

RESUMO

The aim of this study was to investigate the effects of a micronized purified flavonoid fraction (MPFF) on in vivo rat platelet functions. Platelet aggregation and disaggregation were evaluated by a noninvasive, automated isotope monitoring system (AimsPlus). Indium-labeled platelets were injected into anesthetized rats and stimulated by adenosine diphosphate (ADP) (10 microg/kg, i.v.) or collagen (50 microg/kg, i.v.). Fibrinogen binding to ex vivo ADP-activated platelets was determined by flow cytometry. MPFF (100 mg/kg, p.o.) significantly reduced ADP-induced platelet aggregation (p<0.05) and increased platelet disaggregation (p<0.05) compared with controls. Moreover, MPFF inhibited collagen-induced platelet aggregation (p<0.001) and increased platelet disaggregation (p<0.01). In addition, fibrinogen binding to 2.5 or 5 microM ADP-stimulated platelets also was reduced significantly (p<0.05 and 0.01, respectively). These results show that MPFF inhibits in vivo rat platelet functions.


Assuntos
Diosmina/farmacologia , Flavonoides/farmacologia , Hesperidina/farmacologia , Inibidores da Agregação Plaquetária/farmacologia , Agregação Plaquetária/efeitos dos fármacos , Animais , Colágeno/farmacologia , Combinação de Medicamentos , Masculino , Ratos , Ratos Wistar
18.
Proc Natl Acad Sci U S A ; 96(8): 4540-5, 1999 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-10200298

RESUMO

Although initiating mutations in the ret protooncogene have been found in familial and sporadic medullary thyroid carcinoma (MTC), the molecular events underlying subsequent tumor progression stages are unknown. We now report that changes in trk family neurotrophin receptor expression appear to be involved in both preneoplastic thyroid C cell hyperplasia and later tumor progression. Only a subset of normal C cells expresses trk family receptors, but, in C cell hyperplasia, the affected cells consistently express trkB, with variable expression of trkA and trkC. In later stages of gross MTC tumors, trkB expression was substantially reduced, while trkC expression was increased and often intense. In a cell culture model of MTC, exogenous trkB expression resulted in severely impaired tumorigenicity and was associated with 11-fold lower levels of the angiogenesis factor vascular endothelial growth factor. These results suggest that trk family receptor genes participate in MTC development and progression, and, in particular, that trkB may limit MTC tumor growth by inhibition of angiogenesis.


Assuntos
Carcinoma Medular/patologia , Carcinoma Medular/fisiopatologia , Regulação Neoplásica da Expressão Gênica , Proteínas Proto-Oncogênicas/genética , Receptores Proteína Tirosina Quinases/genética , Receptores de Fator de Crescimento Neural/genética , Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/fisiopatologia , Animais , Carcinoma Medular/genética , Progressão da Doença , Feminino , Regulação da Expressão Gênica , Humanos , Hiperplasia , Camundongos , Camundongos Nus , Gravidez , Receptor do Fator Neutrófico Ciliar , Receptor trkA , Receptor trkC , Glândula Tireoide/citologia , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/genética , Transplante Heterólogo , Células Tumorais Cultivadas
19.
Platelets ; 10(1): 66-70, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-16801074

RESUMO

The aim of this study was to investigate the in vivo effects of 50 mg/kg (i.p.) naftazone or ticlopidine on platelet functions in the rat. An automated isotope monitoring system (Aims plus) was used to determine the height of platelet aggregation and disaggregation (measured by the area under the curve, AUC) of 111indium-labelled platelets activated by ADP (10 microg/kg i.v.) or collagen (50 microg/kg i.v.). Fibrinogen-binding experiments were carried out with activated platelets in whole blood and measured by flow cytometry. Naftazone reduced the height of platelet aggregation induced by ADP compared with controls (P = 0.024). Ticlopidine-treated rats gave similar results (P = 0.008). Platelet disaggregation, following the aggregation induced by collagen, was significantly increased in naftazone-treated rats compared with controls (P = 0.003). Similar results were observed with ticlopidine-treated rats (P = 0.002). Fibrinogen binding to 2.5 or 5 microM ADP-stimulated platelets, from naftazone-treated rats, were significantly reduced compared with controls (P = 0.05 and 0.04 respectively). These results show that naftazone has similar inhibitory effects on rat platelet functions as ticloplidine. In conclusion, naftazone could be a useful agent to modulate platelet function in patients with cardiovascular disease.

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