Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 392
Filtrar
1.
Ann Oncol ; 29(6): 1461-1467, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32151367

RESUMEN

BACKGROUND: The efficacy and safety of naldemedine (a peripherally acting µ-opioid receptor antagonist) for opioid-induced constipation (OIC) in subjects with cancer was demonstrated in the primary report of a phase III, double-blind study (COMPOSE-4) and its open-label extension (COMPOSE-5). The primary end point, the proportion of spontaneous bowel movement (SBM) responders, was met. Here, we report results from secondary end points, including quality of life (QOL) assessments from these studies. PATIENTS AND METHODS: In COMPOSE-4, eligible adults with OIC and cancer were randomly assigned 1:1 to receive once-daily oral naldemedine 0.2 mg (n = 97) or placebo (n = 96) for 2 weeks, and those who continued on to COMPOSE-5 received naldemedine for 12 weeks (n = 131). Secondary assessments in COMPOSE-4 included the proportion of complete SBM (CSBM) responders, SBM or CSBM responders by week, and subjects with ≥1 SBM or CSBM within 24 h postinitial dose. Changes from baseline in the frequency of SBMs or CSBMs per week were assessed at weeks 1 and 2. Time to the first SBM or CSBM postinitial dose was also evaluated. In both studies, QOL impact was evaluated by Patient Assessment of Constipation-Symptoms (PAC-SYM) and PAC-QOL questionnaires. RESULTS: Naldemedine improved bowel function for all secondary efficacy assessments versus placebo (all P ≤ 0.0002). The timely onset of naldemedine activity versus placebo was evidenced by median time to the first SBM (4.7 h versus 26.6 h) and CSBM (24.0 h versus 218.5 h) postinitial dose (all P < 0.0001). In COMPOSE-4, significant differences between groups were observed with the PAC-SYM stool domain (P = 0.045) and PAC-QOL dissatisfaction domain (P = 0.015). In COMPOSE-5, significant improvements from baseline were observed for overall and individual domain scores of PAC-SYM and PAC-QOL. CONCLUSIONS: Naldemedine provided effective and timely symptomatic relief from OIC and improved the QOL of subjects with OIC and cancer. TRIAL REGISTRATION ID: www.ClinicalTrials.jp: JAPIC-CTI-132340 (COMPOSE-4) and JAPIC-CTI-132342 (COMPOSE-5).

2.
Neoplasma ; 63(6): 961-966, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27596296

RESUMEN

The transcriptional activity of transforming growth factor-ß (TGF-ß) is increased in subjects with hepatocellular carcinoma (HCC). Recent studies have indicated that the -509C genotype in hepatitis B virus (HBV)-infected subjects and the -509T genotype in hepatitis C virus (HCV)-infected subjects can increase the transcriptional activity of the TGF-ß1 gene. We conducted a meta-analysis to clarify whether these two hepatitis viruses affect the association between TGF-ß1 C-509T variants and HCC susceptibility. Using data derived from 8 case-control studies available in the PubMed database (5 with Asian and 3 with Caucasian populations), including 1,427 cases and 3,735 controls [1,610 patients with chronic liver disease and 2,125 healthy controls], we calculated pooled odds ratios with corresponding 95% confidence intervals. We used dominant (TT + CT vs. CC), recessive (TT vs. CC + CT), and co-dominant (TT vs. CC and CT vs. CC) genetic models. An overall analysis showed no association between the TGF-ß1 C-509T variants and HCC susceptibility for all models. In contrast, a subgroup analysis, based on the infecting hepatitis viruses, provided the following results. Among the cases and controls with chronic liver disease, the TGF-ß1 C-509T variants were significantly associated with decreased HCC susceptibility for two models with HBV-infected subjects, whereas the variants were significantly associated with increased HCC susceptibility for one model with HCV-infected subjects. Among the cases and healthy controls, there was a significant association between the TGF-ß1 C-509T variants and increased HCC susceptibility for two models involving HCV-infected subjects. Among the cases and the entire control group, the same results were obtained for all genetic models with HCV-infected subjects. Although further data accumulation is required, our results suggest that these two hepatitis viruses affect the association between TGF-ß1 C-509T variants and HCC susceptibility in opposite manners.


Asunto(s)
Carcinoma Hepatocelular/genética , Hepatitis B/complicaciones , Neoplasias Hepáticas/genética , Factor de Crecimiento Transformador beta1/genética , Carcinoma Hepatocelular/virología , Susceptibilidad a Enfermedades , Genotipo , Humanos , Neoplasias Hepáticas/virología
4.
Clin Genet ; 78(4): 299-309, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20507342

RESUMEN

The constitutional t(11;22)(q23;q11) is the most common recurrent non-Robertsonian translocation in humans. The breakpoint sequences of both chromosomes are characterized by several hundred base pairs of palindromic AT-rich repeats (PATRRs). Similar PATRRs have also been identified at the breakpoints of other nonrecurrent translocations, suggesting that PATRR-mediated chromosomal translocation represents one of the universal pathways for gross chromosomal rearrangement in the human genome. We propose that PATRRs have the potential to form cruciform structures through intrastrand-base pairing in single-stranded DNA, creating a source of genomic instability and leading to translocations. Indeed, de novo examples of the t(11;22) are detected at a high frequency in sperm from normal healthy males. This review synthesizes recent data illustrating a novel paradigm for an apparent spermatogenesis-specific translocation mechanism. This observation has important implications pertaining to the predominantly paternal origin of de novo gross chromosomal rearrangements in humans.


Asunto(s)
Secuencia Rica en At , Secuencias Repetitivas de Ácidos Nucleicos , Translocación Genética , Aberraciones Cromosómicas , Puntos de Rotura del Cromosoma , Cromosomas Humanos Par 11 , Cromosomas Humanos Par 22 , ADN Cruciforme , ADN de Cadena Simple/genética , Femenino , Genoma Humano , Inestabilidad Genómica , Humanos , Masculino , Espermatogénesis
5.
Science ; 248(4959): 1093-6, 1990 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-17733370

RESUMEN

Carbon dioxide-rich fluid bubbles, containing approximately 86 percent CO(2), 3 percent H(2)S, and 11 percent residual gas (CH(4) + H(2)), were observed to emerge from the sea floor at 1335- to 1550-m depth in the JADE hydrothermal field, mid-Okinawa Trough. Upon contact with seawater at 3.8 degrees C, gas hydrate immediately formed on the surface of the bubbles and these hydrates coalesced to form pipes standing on the sediments. Chemical composition and carbon, sulfur, and helium isotopic ratios indicate that the CO(2)-rich fluid was derived from the same magmatic source as dissolved gases in 320 degrees C hydrothermal solution emitted from a nearby black smoker chimney. The CO(2)-rich fluid phase may be separated by subsurface boiling of hydrothermal solutions or by leaching of CO(2)-rich fluid inclusion during posteruption interaction between pore water and volcanogenic sediments.

6.
Radiat Prot Dosimetry ; 126(1-4): 163-7, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17519243

RESUMEN

Evaluation of the properties for quasi-monoenergetic neutron calibration fields of high energies more than 20 MeV at TIARA is proceeding for development of the field. Among the properties needed for the development as the standard calibration field, we report on measurement of the neutron beam profile using an imaging plate with a polyethylene converter and on estimation of the contribution of scattered neutrons into the irradiation field based on pulse height distribution at various off-beam positions measured using an organic liquid scintillation detector.


Asunto(s)
Neutrones , Aceleradores de Partículas/instrumentación , Aceleradores de Partículas/normas , Radiometría/instrumentación , Radiometría/normas , Calibración , Diseño de Equipo , Análisis de Falla de Equipo , Japón , Dosis de Radiación
7.
Radiat Prot Dosimetry ; 126(1-4): 8-12, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17496303

RESUMEN

The 8 and 27 keV monoenergetic neutron calibration fields have been developed by using (45)Sc(p, n)(45)Ti reaction. Protons from a 4-MV Pelletron accelerator are used to bombard a thin scandium target evaporated onto a platinum disc. The proton energies are finely adjusted to the resonance to generate the 8 and 27 keV neutrons by applying a high voltage to the target assemblies. The neutron energies were measured using the time-of-flight method with a lithium glass scintillation detector. The neutron fluences at a calibration point located at 50 cm from the target were evaluated using Bonner spheres. A long counter was placed at 2.2 m from the target and at 60 degrees to the direction of the proton beam in order to monitor the fluence at the calibration point. Fluence and dose equivalent rates at the calibration point are sufficient to calibrate many types of the neutron survey metres.


Asunto(s)
Neutrones , Radioisótopos/análisis , Radiometría/instrumentación , Radiometría/normas , Escandio/análisis , Titanio/análisis , Calibración , Diseño de Equipo , Análisis de Falla de Equipo , Japón , Radioisótopos/normas , Estándares de Referencia , Escandio/normas , Titanio/normas
8.
AJNR Am J Neuroradiol ; 27(7): 1502-4, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16908568

RESUMEN

We report the usefulness of Guglielmi detachable coil (GDC) embolization by direct carotid puncture for anterior circulation aneurysms. For all 27 patients, GDC embolization by direct carotid puncture was safely performed by using a 5F sheath introducer 5 cm long and a Tracker-38 catheter. Neurologic deficits and hemorrhage were not found in any patient during the follow-up period. If the transfemoral approach cannot be applied, GDC embolization should be considered as an alternative method.


Asunto(s)
Arteria Carótida Común/cirugía , Embolización Terapéutica/métodos , Aneurisma Intracraneal/terapia , Punciones/métodos , Anciano , Anciano de 80 o más Años , Aneurisma Falso/etiología , Anticoagulantes/uso terapéutico , Enfermedades de las Arterias Carótidas/etiología , Arteria Carótida Interna/anatomía & histología , Embolización Terapéutica/instrumentación , Diseño de Equipo , Femenino , Estudios de Seguimiento , Hematoma/etiología , Técnicas Hemostáticas , Heparina/uso terapéutico , Humanos , Masculino , Examen Neurológico , Arteria Oftálmica/patología , Complicaciones Posoperatorias , Seguridad , Hemorragia Subaracnoidea/terapia
9.
AJNR Am J Neuroradiol ; 27(7): 1505-7, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16908569

RESUMEN

BACKGROUND AND PURPOSE: Incomplete stent apposition after carotid angioplasty and stent placement (CAS) is often seen but little is known about how the incomplete attachment goes after stent placement. For example, some may change into restenosis around the stent edge and some may remain unchanged. The purpose of this study is to clarify the morphologic prognosis of an incomplete stent apposition at the stent edge. METHODS: CAS was attempted on 135 consecutive stenotic lesions (124 patients). Angiograms were then evaluated immediately after the procedure. An incomplete stent apposition at stent edge was found in 15 patients, and all of them were followed up by angiography and MR imaging with antiplatelet therapy. RESULTS: No ischemic event caused by the lesions occurred during the mean follow-up period of 11 months (from 4 to 32 months). The angiography findings of 15 lesions at a mean of 8.8 months (from 2 to 28 months) after CAS showed that all remained unchanged. No patients required any additional intervention. No new ischemic lesions were detected in any of the 15 patients who underwent follow-up MR imaging at a mean of 10 months (from 2 to 32 months) after CAS. CONCLUSION: In this study, the existence of a segment of incomplete stent apposition had no adverse morphologic or clinical effect.


Asunto(s)
Angioplastia de Balón/métodos , Estenosis Carotídea/terapia , Stents , Anciano , Anciano de 80 o más Años , Angioplastia de Balón/instrumentación , Aspirina/uso terapéutico , Isquemia Encefálica/prevención & control , Arterias Carótidas/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Inhibidores de Agregación Plaquetaria/uso terapéutico , Pronóstico , Radiografía Intervencional , Recurrencia , Estudios Retrospectivos , Stents/efectos adversos , Ticlopidina/uso terapéutico
10.
AJNR Am J Neuroradiol ; 27(1): 151-6, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16418376

RESUMEN

BACKGROUND AND PURPOSE: Because carotid plaque ulceration is associated with an increased risk of cerebral embolism, residual carotid plaque ulceration directly around a stent (persistent ulceration) after carotid angioplasty and stent placement (CAS) could still be a risk factor for a stroke. The purpose of this study is to understand the morphologic and clinical prognosis of persistent ulceration. PATIENTS AND TECHNIQUES: CAS was attempted on 91 consecutive stenotic lesions (80 patients). Of these, 54 lesions (48 patients) had ulceration before CAS. Angiograms were evaluated immediately after the procedure. Persistent ulceration was found in 34 lesions (30 patients). The mean depth and length of persistent ulcers were 2.1 mm (range, 1-4.7 mm) and 8.9 mm (range, 1.5-22 mm), respectively. All patients with persistent ulceration were followed with antiplatelet therapy. RESULTS: No ischemic event due to the lesions occurred during the mean follow-up period of 25.5 months (range, 3-48 months). Angiography on 25 lesions (21 patients) at a mean of 5.8 months (range, 1-21 months) after CAS showed that persistent ulceration disappeared in 12 lesions (48%), improved in 11 lesions (44%), and remained unchanged in 2 lesions (8%). Nine lesions (36%) showed restenosis, which were < or =30% and did not require any additional intervention. New ischemic lesions were not detected in any of the 14 patients (17 lesions) who underwent follow-up MR imaging at a mean of 9 months (range, 1-32 months) after CAS. CONCLUSION: We conclude that persistent ulceration after CAS improves spontaneously and is not a risk factor for cerebral embolism.


Asunto(s)
Estenosis Carotídea/terapia , Stents , Anciano , Anciano de 80 o más Años , Angioplastia de Balón , Estenosis Carotídea/complicaciones , Estenosis Carotídea/diagnóstico por imagen , Estenosis Carotídea/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radiografía , Factores de Riesgo , Accidente Cerebrovascular/etiología , Úlcera/diagnóstico por imagen , Úlcera/patología
11.
J Natl Cancer Inst ; 80(19): 1564-7, 1988 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-3193471

RESUMEN

A rapid-production model incorporating the principle of selection by resistance to cytotoxicity demonstrated earlier for liver carcinogenesis in rats was established for pancreatic carcinoma development in Syrian hamsters. Adenocarcinomas were induced in 84% of treated animals by 10 weeks after initiation with 70 mg of N-nitroso-bis(2-oxopropyl)amine (BOP) per kg of body weight when augmentation pressure (choline-deficient diet combined with DL-ethionine and L-methionine and administration of 20 mg/kg BOP upon return to basal diet) was applied three times. A 52% yield of cholangiocellular tumors also resulted from this experimental protocol.


Asunto(s)
Carcinógenos , Carcinoma/etiología , Nitrosaminas/toxicidad , Neoplasias Pancreáticas/etiología , Animales , Deficiencia de Colina/complicaciones , Cocarcinogénesis , Cricetinae , Dieta , Etionina/administración & dosificación , Femenino , Hígado/efectos de los fármacos , Mesocricetus , Metionina/administración & dosificación
12.
J Natl Cancer Inst ; 81(5): 367-70, 1989 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-2915373

RESUMEN

We used 29 polymorphic DNA markers to analyze tumor DNA samples from six patients with sporadic pheochromocytoma for possible loss of chromosomal heterozygosity; four had benign disease and two had malignant disease. Loss of heterozygosity was observed on four chromosomes: 1p (three of four patients), 2p (one of one), 5q (two of six), and 11p (three of five). Chromosomes 1p and 11p frequently had allelic deletions in these tumors, and these deletions may play an important role in the development of pheochromocytoma.


Asunto(s)
Neoplasias de las Glándulas Suprarrenales/genética , Deleción Cromosómica , Cromosomas Humanos Par 11 , Cromosomas Humanos Par 1 , Feocromocitoma/genética , ADN de Neoplasias/análisis , Genotipo , Humanos
13.
Cancer Res ; 55(13): 2719-22, 1995 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-7796392

RESUMEN

Mutations in the adenomatous polyposis coli (APC) gene are responsible for not only familial adenomatous polyposis but also many sporadic cancers of the digestive tract. Most mutations found in familial adenomatous polyposis patients are of the truncation type, and the phenotype is affected by the mutation sites in the gene. Truncated APC proteins can associate with the wild-type protein. Accordingly, it has been proposed that the polyposis is caused by a dominant negative mechanism. To test this possibility, we constructed transgenic mice that contained mutant minigenes. They expressed the APC protein truncated either at codon 716 (Apc delta 716) or 1287 (Apc delta 1287) at high levels in the intestinal epithelium. Contrary to our expectation, no intestinal polyps or tumors were found in any of such mice, even after 7 months. These results rule out any dominant negative mechanisms in which the truncated APC protein is directly involved in the formation of intestinal polyps in the mouse.


Asunto(s)
Proteínas del Citoesqueleto/genética , Pólipos Intestinales/genética , Proteína de la Poliposis Adenomatosa del Colon , Secuencia de Aminoácidos , Animales , Genes Dominantes , Genes Supresores de Tumor , Humanos , Pólipos Intestinales/patología , Intestino Delgado/patología , Ratones , Ratones Transgénicos , Datos de Secuencia Molecular , Mutación , Péptidos/química , Eliminación de Secuencia
14.
Cancer Res ; 59(16): 3904-7, 1999 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-10463579

RESUMEN

To allow a study of beta-catenin mutations in hepatocellular carcinomas (HCCs) induced by exogenous and endogenous carcinogens, we induced tumors in male Fischer 344 rats with N-nitrosodiethylamine and a choline-deficient L-amino acid-defined diet. Administration of the former was followed by partial hepatectomy with colchicine to induce cell cycle disturbance and a selection pressure regimen (K. Ohashi et al., Cancer Res., 56: 3474-3479, 1996; M. Tsutsumi et al., Jpn. J. Cancer Res., 87: 5-9, 1996). HCCs were obtained after 42 weeks. With continuous choline-deficient L-amino acid-defined feeding, tumors were sampled after 75 weeks. Total RNA was extracted from individual lesions and mutations in the glycogen synthase kinase-3beta phosphorylation consensus motif of beta-catenin were investigated by reverse transcriptase-PCR-single-strand conformation polymorphism analysis followed by nucleotide sequencing. Changes were detected in 5 of 11 HCCs induced by the exogenous carcinogen. The observed shifts of C:G-->G:C or C:G-->A:T at codon 33 and G:C-->T:A transversions at codon 34 were associated with beta-catenin protein accumulation and confirmed by Western blot analysis. Only 2 of 15 HCCs induced in the endogenous carcinogenesis regimen demonstrated mutations, those being transitions of C:G-->T:A at codon 41 without amino acid alteration. These results suggest that different genetic pathways underlie exogenous and endogenous liver carcinogenesis in rats.


Asunto(s)
Carcinógenos/toxicidad , Proteínas del Citoesqueleto/genética , Dieta/efectos adversos , Dietilnitrosamina/toxicidad , Neoplasias Hepáticas Experimentales/etiología , Neoplasias Hepáticas Experimentales/genética , Mutágenos/toxicidad , Mutación , Transactivadores , Aminoácidos/administración & dosificación , Animales , Deficiencia de Colina , Masculino , Ratas , Ratas Endogámicas F344 , beta Catenina
15.
Cancer Res ; 57(9): 1644-9, 1997 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-9135000

RESUMEN

Mutations in the human adenomatous polyposis coli (APC) gene are responsible for not only familial adenomatous polyposis but also many sporadic cancers of the digestive tract. Using homologous recombination in embryonic stem cells, we recently constructed Apc gene knockout mice that contained a truncation mutation at codon 716 (Apc(delta716)). The heterozygous mice developed numerous intestinal polyps. All microadenomas dissected from nascent polyps had already lost the wild-type allele, indicating the loss of heterozygosity (M. Oshima et al., Proc. Natl. Acad. Sci. USA, 92: 4482-4486, 1995). We also demonstrated that cyclooxygenase 2 is induced in the polyps at an early stage and plays a key role in polyp development (M. Oshima et al., Cell 87: 803-809, 1996). We have analyzed the process of polyp development in these mice both at morphological and molecular levels. A small intestinal microadenoma is initiated as an outpocketing pouch in a single crypt and develops into the inner (lacteal) side of a neighboring villus forming a double-layer nascent polyp. The microadenoma then enlarges and gets folded inside the villus. When it fills the intravillous space, it expands downward and extends into adjoining villi, rather than rupturing into the intestinal lumen. During this course of development, the basement membrane remains intact, and the labeling index of the microadenoma cells is similar to that of the normal crypt epithelium. As in the crypt cells, neither transforming growth factor beta1 nor its receptor type II is expressed in the microadenoma cells. No hot spot mutations in the K-ras gene are found in the microadenoma tissue during these early stages of polyp development. Essentially, the same results have been obtained for the colonic polyps as well. These results suggest that early adenomas in the Apc(delta716) polyps are very similar to the normal proliferating cells of the crypt except for the lack of directed migration along the crypt-villus axis.


Asunto(s)
Receptores de Activinas Tipo I , Proteínas del Citoesqueleto/deficiencia , Pólipos Intestinales/patología , Adenoma/genética , Adenoma/patología , Proteína de la Poliposis Adenomatosa del Colon , Animales , División Celular , Heterocigoto , Neoplasias Intestinales/genética , Neoplasias Intestinales/patología , Pólipos Intestinales/genética , Ratones , Ratones Noqueados , Lesiones Precancerosas/patología , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Proto-Oncogénicas p21(ras)/genética , Receptor Tipo I de Factor de Crecimiento Transformador beta , Receptor Tipo II de Factor de Crecimiento Transformador beta , Receptores de Factores de Crecimiento Transformadores beta/metabolismo
16.
Cancer Res ; 60(23): 6611-6, 2000 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-11118043

RESUMEN

In the present study, we investigated mutations of the adenomatous polyposis coli (APC) and beta-catenin genes to clarify possible molecular mechanisms underlying development of lung tumors induced by N-nitrosobis(2-hydroxypropyl)amine (BHP) in rats. Male Wistar rats, 6 weeks of age, were given 2000 ppm BHP in drinking water for 12 weeks and then maintained without further treatment until sacrifice at week 25 DNA was extracted from paraffin-embedded tissues, and PCR-single-strand conformation polymorphism analysis, followed by nucleotide sequencing, was performed. No APC mutations were detected in 17 hyperplasias, but 2 of 15 adenomas (13.3%) and 8 of 20 adenocarcinomas (40.0%) showed changes within exon 1 to the mutation cluster region in exon 15. For beta-catenin, no mutations were detected in 17 hyperplasias, but 3 of 15 adenomas (20.0%) and 5 of 20 adenocarcinomas (25.0%) had alterations within or flanking codons corresponding to important phosphorylation sites. Immunohistochemical staining showed beta-catenin protein localized in the cell membranes in the surrounding normal-appearing lung and 216 hyperplasias and localized mainly in the cytoplasm and/or nucleus in 10 of 37 adenomas (27.0%) and 21 of 40 adenocarcinomas (52.5%). These results suggest that the APC-beta-catenin-T-cell factor signaling pathway is involved in the acquisition of growth advantage from adenomas to adenocarcinomas in BHP-induced rat lung carcinogenesis.


Asunto(s)
Proteínas del Citoesqueleto/genética , Genes APC/genética , Neoplasias Pulmonares/genética , Mutación Missense , Transactivadores , Adenocarcinoma/inducido químicamente , Adenocarcinoma/genética , Adenoma/inducido químicamente , Adenoma/genética , Animales , Carcinógenos/toxicidad , Análisis Mutacional de ADN , Progresión de la Enfermedad , Genes APC/efectos de los fármacos , Inmunohistoquímica , Neoplasias Pulmonares/inducido químicamente , Neoplasias Pulmonares/patología , Masculino , Mutágenos/toxicidad , Nitrosaminas/toxicidad , Reacción en Cadena de la Polimerasa , Polimorfismo Conformacional Retorcido-Simple , Ratas , Ratas Wistar , Transducción de Señal/fisiología , Factores de Transcripción/fisiología , beta Catenina
17.
Cancer Res ; 46(9): 4782-6, 1986 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-3731125

RESUMEN

The effects of cholecystectomy and/or lithocholic acid (LCA) on the composition of biliary bile acid and on pancreatic carcinogenesis by N-nitrosobis(2-hydroxypropyl)amine (BHP) were examined in male Syrian golden hamsters. Cholecystectomy was performed 1 wk before BHP initiation. BHP (250 mg/kg of body weight) was injected s.c. once a wk for 5 wk. A diet containing 0.5% LCA was begun 1 wk after the final BHP injection. All hamsters were sacrificed 36 wk after cholecystectomy, and the pancreas was examined histologically. Only the LCA treatment but no other treatment influenced the bile acid composition, i.e., the increase in LCA and decrease in cholic acid. The incidence of pancreatic carcinoma was 23 of 30 (76.7%) in hamsters receiving cholecystectomy plus BHP followed by LCA diet. The tumor incidence was five of 18 (27.8%) with BHP followed by basal diet, ten of 18 (55.6%) with cholecystectomy plus BHP followed by basal diet, and six of 18 (33.3%) with BHP followed by LCA diet, respectively. The total number of pancreatic carcinomas in hamsters receiving cholecystectomy and BHP followed by LCA diet also increased significantly. These results indicate that combined treatments of cholecystectomy and dietary LCA enhanced BHP-inducing pancreatic carcinogenesis in hamsters.


Asunto(s)
Carcinoma/etiología , Colecistectomía , Ácido Litocólico , Nitrosaminas , Neoplasias Pancreáticas/etiología , Adenocarcinoma/etiología , Adenocarcinoma/patología , Animales , Ácidos y Sales Biliares/análisis , Carcinoma/patología , Carcinoma in Situ/etiología , Carcinoma in Situ/patología , Cricetinae , Masculino , Mesocricetus , Neoplasias Pancreáticas/patología
18.
Cancer Res ; 51(3): 820-3, 1991 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-1670999

RESUMEN

Several recent studies based on restriction fragment length polymorphism analysis have supported the concept that the accumulation of multiple genetic alterations converts a normal cell to a malignant cell. Activation of oncogenes and/or inactivation of tumor suppressor genes have been observed during tumor progression in colorectal cancer, lung cancer, and breast cancer. To investigate the possibility that multiple genes are altered during the progression of renal cell carcinoma, we have used restriction fragment length polymorphism markers throughout the genome to test for loss of heterozygosity in 38 renal cell carcinomas. Nearly 64% of the tumors had lost heterozygosity on the short arm of chromosome 3. We also observed loss of heterozygosity averaging about 30% at informative loci on six other chromosomal arms (chromosomes 5q, 6q, 10q, 11q, 17p, and 19p). These results lead us to suspect the existence of several tumor suppressor genes associated with carcinogenesis of renal cell carcinoma.


Asunto(s)
Carcinoma de Células Renales/genética , Genes Supresores/genética , Heterocigoto , Neoplasias Renales/genética , Mapeo Cromosómico , Humanos , Polimorfismo de Longitud del Fragmento de Restricción
19.
Cancer Res ; 57(7): 1281-7, 1997 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-9102214

RESUMEN

The question of whether 8-hydroxyguanine (8-OHG) formation is involved in initiation by low dose levels of N-nitrosodiethylamine (DEN) was addressed using a rat liver model. Male Fischer 344 rats, 6 weeks of age, were administered single i.p. doses of DEN between 0.001 and 100 mg/kg body weight. The 8-OHG levels in liver DNA were measured within 72 h thereafter in randomly selected rats. The remaining rats were given either no further treatment, partial hepatectomy (PH) at hour 4, or PH with i.p. administration of 500 mg/kg body weight of colchicine on days 1 and 3. A selection procedure was performed between weeks 2 and 4, and the initiating activity of DEN was assessed in terms of development of gamma-glutamyltransferase-positive foci at week 5. The 8-OHG levels in the liver DNA were significantly elevated between hours 6 and 72 in a manner dependent on the DEN dose. Dose-dependent induction of foci was similarly noted with doses of 1-100 and 0.001-100 mg/kg body weight in the non-PH and the PH rats, respectively. The sizes of the foci were also significantly increased in a manner dependent on the DEN doses of 1-100 and 0.001-100 mg/kg body weight in the non-colchicine-treated and the colchicine-treated rats, respectively. Statistically, linear trends of 8-OHG formation due to DEN were different at 0.001-0.1 and 1-100 mg/kg body weight, but the total adducts formed within 72 h of the administration proved to be closely related to the development of foci at the termination. These results indicate that 8-OHG formation in the liver DNA may be involved in DEN initiation of hepatocarcinogenesis even at low dose levels, and that single i.p. doses of 0.001-0.1 and 1-100 mg/kg body weight might exert different effects.


Asunto(s)
Dietilnitrosamina/administración & dosificación , Guanina/análogos & derivados , Neoplasias Hepáticas/inducido químicamente , Neoplasias Hepáticas/metabolismo , 2-Acetilaminofluoreno/farmacología , Animales , Tetracloruro de Carbono/farmacología , Colchicina/farmacología , Relación Dosis-Respuesta a Droga , Guanina/metabolismo , Riñón/metabolismo , Modelos Lineales , Neoplasias Hepáticas/terapia , Pulmón/metabolismo , Masculino , Miocardio/metabolismo , Páncreas/metabolismo , Ratas , Ratas Endogámicas F344 , Medición de Riesgo , Factores de Tiempo , gamma-Glutamiltransferasa/metabolismo
20.
Cancer Res ; 53(20): 5038-42, 1993 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-8402697

RESUMEN

The relationship between expression of nucleoside diphosphate kinase (NDP kinase)/nm23, c-Ha-ras, and c-myc genes and metastatic potential was assessed in rat-transplantable osteosarcoma lines, derived from spontaneous and chemical carcinogen (4-hydroxyamino quinoline 1-oxide)-induced osteosarcomas in Fischer 344/NS1c rats. These osteosarcomas possess metastatic potential and highly metastatic lines spontaneous osteosarcoma-selected lung metastatic lesions and 4-hydroxyamino-quinoline 1-oxide-induced osteosarcoma-selected lung metastatic lesions were respectively established by selectively transplanting lung metastatic lesions. Northern blot analysis revealed that the levels of NDP kinase/nm23 and c-Ha-ras gene expression were increased in line with metastatic ability; thus transcript levels were remarkably greater in both spontaneous osteosarcoma-selected lung metastatic lesions and 4-hydroxyamino-quinoline 1-oxide-induced osteosarcoma-selected lung metastatic lesions highly metastatic lines than in their respective low metastatic spontaneous and chemical carcinogen (4-hydroxyamino quinoline 1-oxide)-induced osteosarcoma counterparts. c-myc mRNA expression was observed in all tumor lines, without any correlation with metastatic ability. Southern blot analysis did not show evidence of gross rearrangement or amplification of NDP kinase/nm23, c-Ha-ras, or c-myc genes suggesting regulation of their gene expression at the transcriptional and/or posttranscriptional level. These results indicate that NDP kinase/nm23 and c-Ha-ras might be cooperatively involved in a positive manner in signal transduction processes, especially involving G-protein reactions, responsible for metastasis of rat-transplantable osteosarcomas.


Asunto(s)
Neoplasias Óseas/metabolismo , Genes ras , Neoplasias Pulmonares/secundario , Nucleósido-Difosfato Quinasa/biosíntesis , Osteosarcoma/secundario , ARN Mensajero/biosíntesis , Animales , Secuencia de Bases , Neoplasias Óseas/enzimología , Neoplasias Óseas/patología , Cartilla de ADN , Genes myc , Riñón/enzimología , Hígado/enzimología , Neoplasias Pulmonares/enzimología , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Datos de Secuencia Molecular , Miocardio/enzimología , Osteosarcoma/enzimología , Osteosarcoma/metabolismo , Osteosarcoma/patología , Páncreas/enzimología , Reacción en Cadena de la Polimerasa , Ratas , Ratas Endogámicas F344 , Transcripción Genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA