Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 179
Filtrar
1.
Immunohematology ; 37(4): 178-184, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34964317

RESUMEN

Unusual and discrepant ABO phenotypes are often due to genetic variants that lead to altered levels or activity of ABO transferases and consequently to altered expression of ABO antigens. This report describes eight genetic alterations found in 15 cases with reduced or undetectable expression of ABO antigens. Forward and reverse ABO grouping was performed by standard gel or tube methods. Adsorption-heat elution and saliva testing for H and A substances followed the AABB technical manual procedures. Genomic DNA extracted from whole blood was PCR-amplified to cover the entire ABO coding sequence, splice junctions, proximal promoter, and intron 1 enhancer. Amplification products were sequenced by next-generation or Sanger dideoxy methods, either directly or after cloning into a bacterial plasmid vector. Eight unreported alleles were found in the 15 cases analyzed. Alleles ABO*A(28+1C) and ABO*A(29-5G) harbor variants that alter the consensus sequence at the intron 1 donor and acceptor splice sites, respectively. The other alleles harbor variants that alter the consensus sequence at transcription factor-binding sites in the intron 1 enhancer: specifically, ABO*A(28+5792T), ABO*A(28+5859A), and ABO*A(28+5860G) at GATA-1 sites; ABO*B(28+5877T) and ABO*B(28+5878G) at a RUNX1 site; and ABO*A(28+5843A) at or near a C/EBP site. Molecular and serologic characterization of ABO alleles can help in their future identification and in the resolution of discrepancies.Unusual and discrepant ABO phenotypes are often due to genetic variants that lead to altered levels or activity of ABO transferases and consequently to altered expression of ABO antigens. This report describes eight genetic alterations found in 15 cases with reduced or undetectable expression of ABO antigens. Forward and reverse ABO grouping was performed by standard gel or tube methods. Adsorption-heat elution and saliva testing for H and A substances followed the AABB technical manual procedures. Genomic DNA extracted from whole blood was PCR-amplified to cover the entire ABO coding sequence, splice junctions, proximal promoter, and intron 1 enhancer. Amplification products were sequenced by next-generation or Sanger dideoxy methods, either directly or after cloning into a bacterial plasmid vector. Eight unreported alleles were found in the 15 cases analyzed. Alleles ABO*A(28+1C) and ABO*A(29­5G) harbor variants that alter the consensus sequence at the intron 1 donor and acceptor splice sites, respectively. The other alleles harbor variants that alter the consensus sequence at transcription factor­binding sites in the intron 1 enhancer: specifically, ABO*A(28+5792T), ABO*A(28+5859A), and ABO*A(28+5860G) at GATA-1 sites; ABO*B(28+5877T) and ABO*B(28+5878G) at a RUNX1 site; and ABO*A(28+5843A) at or near a C/EBP site. Molecular and serologic characterization of ABO alleles can help in their future identification and in the resolution of discrepancies.


Asunto(s)
Sistema del Grupo Sanguíneo ABO , Sistema del Grupo Sanguíneo ABO/genética , Alelos , Humanos , Intrones , Mutación , Fenotipo
2.
Vox Sang ; 113(3): 268-274, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29359471

RESUMEN

BACKGROUND: During massive transfusion, the volume ratio of administered plasma (PL Vol) to red blood cell (RBC Vol) appears to be associated with reduced blood utilization and improved survival. The aim of this study was to evaluate the optimal component ratio in the setting of liver transplantation. METHODS: This is a retrospective chart review of patients who underwent liver transplantation and received at least 500 ml of red blood cells from January 2013 through December 2015. Kernel smoothing analysis determined the proper component ratios to evaluate were a ≥0·85:1 ratio (high) to a ≤0·85:1 ratio (low). Two groups, plasma volume to RBC volume (PL Vol/RBC Vol) and plasma contained in the platelet units added to the plasma calculation [PL + PLT (platelet)] Vol/RBC Vol, were used to evaluate the component ratios. RESULTS: A total of 188 patients were included in the analysis. In the PL Vol/RBC Vol evaluation, a low ratio revealed that 1238 ml (977-1653 ml) (P < 0·0001) and 1178 ml (747-1178) (P < 0·0001) of RBC were used in excess compared to the high ratio, in the univariable and multivariable analysis, respectively. In the PL +PLT Vol/RBC Vol evaluation, a low ratio used 734 ml (193-1275) (P = 0·008) and 886 ml (431-1340) (P < 0·0001) of RBC in excess when compared to high ratio in the univariable and multivariable analysis, respectively. CONCLUSION: In patients undergoing liver transplantation, the transfusion of plasma to RBC ratio ≥0·85 was associated with decreased need of RBC transfusions.


Asunto(s)
Transfusión de Eritrocitos/métodos , Trasplante de Hígado/métodos , Adulto , Recuento de Eritrocitos , Transfusión de Eritrocitos/efectos adversos , Transfusión de Eritrocitos/normas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Plasma , Estudios Retrospectivos
3.
Vox Sang ; 2018 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-29714029

RESUMEN

BACKGROUND AND OBJECTIVES: Blood utilization during liver transplant has decreased, but remains highly variable due to many complex surgical and physiologic factors. Previous models attempted to predict utilization using preoperative variables to stratify cases into two usage groups, usually using entire blood units for measurement. We sought to develop a practical predictive model using specific transfusion volumes (in ml) to develop a data-driven patient blood management strategy. MATERIALS AND METHODS: This is a retrospective evaluation of primary liver transplants at a single institution from 2013 to 2015. Multivariable analysis of preoperative recipient and donor factors was used to develop a model predictive of intraoperative red-blood-cell (pRBC) use. RESULTS: Of 256 adult liver transplants, 207 patients had complete transfusion volume data for analysis. The median intraoperative allogeneic pRBC transfusion volume was 1250 ml, and the average was 1563 ± 1543 ml. Preoperative haemoglobin, spontaneous bacterial peritonitis, preoperative haemodialysis and preoperative international normalized ratio together yielded the strongest model predicting pRBC usage. When it predicted <1250 ml of pRBCs, all cases with 0 ml transfused were captured and only 8·6% of the time >1250 ml were used. This prediction had a sensitivity of 0·91 and a specificity of 0·89. If predicted usage was >2000 ml, 75% of the time blood loss exceeded 2000 ml. CONCLUSION: Patients likely to require low or high pRBC transfusion volumes were identified with excellent accuracy using this predictive model at our institution. This model may help predict bleeding risk for each patient and facilitate optimized blood ordering.

4.
Ann Oncol ; 27(6): 1155-1160, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27013395

RESUMEN

BACKGROUND: Over the past decade, numerous reports describe the generation and increasing utility of non-small-cell lung cancer (NSCLC) patient-derived xenografts (PDX) from tissue biopsies. While PDX have proven useful for genetic profiling and preclinical drug testing, the requirement of a tissue biopsy limits the available patient population, particularly those with advanced oligometastatic disease. Conversely, 'liquid biopsies' such as circulating tumour cells (CTCs) are minimally invasive and easier to obtain. Here, we present a clinical case study of a NSCLC patient with advanced metastatic disease, a never smoker whose primary tumour was EGFR and ALK wild-type. We demonstrate for the first time, tumorigenicity of their CTCs to generate a patient CTC-derived eXplant (CDX). PATIENTS AND METHODS: CTCs were enriched at diagnosis and again 2 months later during disease progression from 10 ml blood from a 48-year-old NSCLC patient and implanted into immunocompromised mice. Resultant tumours were morphologically, immunohistochemically, and genetically compared with the donor patient's diagnostic specimen. Mice were treated with cisplatin and pemetrexed to assess preclinical efficacy of the chemotherapy regimen given to the donor patient. RESULTS: The NSCLC CDX expressed lung lineage markers TTF1 and CK7 and was unresponsive to cisplatin and pemetrexed. Examination of blood samples matched to that used for CDX generation revealed absence of CTCs using the CellSearch EpCAM-dependent platform, whereas size-based CTC enrichment revealed abundant heterogeneous CTCs of which ∼80% were mesenchymal marker vimentin positive. Molecular analysis of the CDX, mesenchymal and epithelial CTCs revealed a common somatic mutation confirming tumour origin and showed CDX RNA and protein profiles consistent with the predominantly mesenchymal phenotype. CONCLUSIONS: This study shows that the absence of NSCLC CTCs detected by CellSearch (EpCAM(+)) does not preclude CDX generation, highlighting epithelial to mesenchymal transition and the functional importance of mesenchymal CTCs in dissemination of this disease.


Asunto(s)
Biomarcadores de Tumor/genética , Carcinogénesis/genética , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Células Neoplásicas Circulantes/patología , Animales , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Cisplatino/administración & dosificación , Proteínas de Unión al ADN/genética , Transición Epitelial-Mesenquimal/genética , Humanos , Células Madre Mesenquimatosas/patología , Ratones , Mutación , Células Neoplásicas Circulantes/efectos de los fármacos , Células Madre Neoplásicas/patología , Pemetrexed/administración & dosificación , Factores de Transcripción/genética , Ensayos Antitumor por Modelo de Xenoinjerto
5.
Int J Clin Pract ; 70(4): 340-50, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26987888

RESUMEN

AIM: While the introduction of the treat-to-target (T2T) strategy has been an important advance in the management of rheumatoid arthritis (RA), the potential for increased toxicity due to use of concurrent drugs could adversely affect patient reported outcomes (PROs). The objective was to determine whether the cessation of therapy due to toxicity affects long-term improvement in PROs in patients treated according to T2T strategy. METHODS: A total of 149 patients from an inception cohort of early RA were included. The occurrence and severity of toxicity were monitored at each visit over 3 years. PROs studied were function (measured using health assessment questionnaire); pain, fatigue and patient global assessment (PtGA) all assessed using a 100 mm visual analogue scale; helplessness and health-related quality of life (HRQoL). For each PRO, effect of drug withdrawal was measured by comparing mean change in PROs among patients with no/temporary vs. permanent withdrawal. In addition, effects of frequency of drug withdrawals, weeks to withdrawal and number of drugs withdrawn were analysed using linear regression. RESULT: After 3 years, 56 (37.4%) patients ceased at least one drug permanently due to toxicity. Patients with no/temporary withdrawal (n = 93) achieved significantly greater improvement in function (mean change = -0.54 vs. -0.31, p = 0.033), pain (mean change = -39.82 vs. -5.02, p = 0.018), fatigue (mean change = -29.14 vs. -14.76, p = 0.015) and PtGA (mean change = -29.64 vs. -17.00, p = 0.018) compared with their counterparts. Higher frequency of withdrawals was associated with lesser improvements in function, pain, fatigue and PtGA, while the number of drugs withdrawn and the weeks to withdrawal had lesser effects. However, the cessation of the drugs due to their toxicity did not have a significant association with HRQoL and helplessness. CONCLUSION: Improvements in function, pain, fatigue and PtGA at 3 years were diminished for patients who ceased drugs due to toxicity while broader measures of HRQoL were not affected.


Asunto(s)
Antirreumáticos/efectos adversos , Artritis Reumatoide/tratamiento farmacológico , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Medición de Resultados Informados por el Paciente , Encuestas y Cuestionarios , Anciano , Antirreumáticos/uso terapéutico , Artritis Reumatoide/diagnóstico , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Calidad de Vida , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Australia del Sur/epidemiología , Resultado del Tratamiento
6.
Br J Cancer ; 110(5): 1118-24, 2014 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-24448364

RESUMEN

BACKGROUND: Thrombotic events are common in cancer patients and have been associated with an adverse prognosis in large registry-based studies. METHODS: A retrospective cohort of 417 patients with ovarian cancer treated at a tertiary cancer centre between 2006 and 2009 was studied to identify the incidence and risk factors for thrombotic events and the prognostic impact of thrombosis. Patient outcomes were evaluated against a matched control group without thrombosis. RESULTS: Ninety-nine thrombotic events occurred in 90 patients (21.6%) from 8 months before diagnosis to 56 months following diagnosis, peaking in the 4 months following diagnosis. Patients with thrombosis were older (mean 65 vs 61 years, P=0.007), had a worse performance status (PS ≥2: 29.9% vs 9.5%, P<0.0001) and had a more advanced FIGO stage (FIGO III/IV 75.6% vs 56.9%, P<0.0001) than patients without thrombosis. Shorter overall survival was seen in patients with pulmonary embolism and pelvic/lower limb deep vein thrombosis than without thrombosis (P=0.001). When the control group was matched for stage and PS, no survival difference was seen (P=0.91). CONCLUSION: Ovarian cancer patients with thrombotic events had a shorter survival. However, when matched for prognostic factors (PS and FIGO stage), thrombosis did not impact upon prognosis.


Asunto(s)
Neoplasias Ováricas/sangre , Trombosis/etiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Humanos , Incidencia , Persona de Mediana Edad , Proyectos Piloto , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Adulto Joven
7.
Science ; 369(6509): 1347-1351, 2020 09 11.
Artículo en Inglés | MEDLINE | ID: mdl-32913099

RESUMEN

Cold dark matter (CDM) constitutes most of the matter in the Universe. The interplay between dark and luminous matter in dense cosmic environments, such as galaxy clusters, is studied theoretically using cosmological simulations. Observations of gravitational lensing are used to characterize the properties of substructures-the small-scale distribution of dark matter-in clusters. We derive a metric, the probability of strong lensing events produced by dark-matter substructure, and compute it for 11 galaxy clusters. The observed cluster substructures are more efficient lenses than predicted by CDM simulations, by more than an order of magnitude. We suggest that systematic issues with simulations or incorrect assumptions about the properties of dark matter could explain our results.

8.
Science ; 158(3809): 1694-5, 1967 Dec 29.
Artículo en Inglés | MEDLINE | ID: mdl-4228706

RESUMEN

Investigations using housefly mitochondria revealed several salicylanilide derivatives as the most effective uncoupling agents of oxidative phosphorylation reported so far. Even greater inhibition of the associated P(i)-adenosine triphosphate exchange was shown with these compounds in both housefly and rat-liver mitochondria, and close similarity was observed between the two types of organelles.


Asunto(s)
Anilidas/farmacología , Fosforilación Oxidativa/efectos de los fármacos , Salicilatos/farmacología , Adenosina Trifosfatasas/antagonistas & inhibidores , Adenosina Trifosfato/metabolismo , Animales , Dinitrofenoles/farmacología , Moscas Domésticas , Mitocondrias/metabolismo , Oligomicinas/farmacología , Ratas
9.
Science ; 170(3956): 455-7, 1970 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-5460073

RESUMEN

Cholinesterase from frozen sections of honey bee (Apis mellifera, L.) brain hydrolyzes phenylthioacetate and acetylthiocholine to give virtually identical patterns of enzyme distribution with and without the use of paraoxon. In addition, phenylthioacetate is an economical substrate for in vitro and in vivo studies of cholinesterase. Phenylthioacetate offers the advantages of being easily synthesized and lipoid soluble, and appears to penetrate membranes easily.


Asunto(s)
Abejas/metabolismo , Encéfalo/enzimología , Colinesterasas/análisis , Glicolatos/metabolismo , Acetilcolina/metabolismo , Animales , Inhibidores de la Colinesterasa , Colorimetría , Electroforesis Discontinua , Histocitoquímica , Nitrofenoles , Fosfatos
10.
J Clin Invest ; 98(8): 1788-93, 1996 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-8878429

RESUMEN

Malignant B-1 cells derived from NZB mice, a murine model of spontaneous autoimmunity and B cell lymphoproliferative disease, produce significantly higher levels of IL-10 mRNA than normal B-1 or B cells. IL-10 may act as an autocrine growth factor for the expansion of malignant B-1 cells. In order to determine if elevated endogenous production of IL-10 was a required element for the malignant transformation of B-1 cells in NZB mice, backcross animals were studied for the linkage between elevated IL-10 expression and the presence of lymphoid malignancy. The phenotypes of aged (NZB x DBA/2)F1 x NZB animals were determined and a strong correlation was found between the elevated levels of IL-10 mRNA and the development of B-1 malignant clones. In contrast, an increased level of IL-10 message was not associated with elevated serum IgM or the presence of anemia or reticulocytosis which is mainly seen in response to autoantibody production. These results indicate that, at least in NZB, the autoimmunity and lymphoproliferation phenotypes are not linked genetically. IL-10 may enhance proliferation and the development of B-1 cell malignancy rather than antibody production by the B-1 cell subpopulation. Thus, IL-10 plays an important role in B-1 malignancies, and downregulation of IL-10 could be a likely site for intervention in B cell malignancies.


Asunto(s)
Interleucina-10/fisiología , Leucemia Linfocítica Crónica de Células B/etiología , Animales , Cruzamientos Genéticos , Interleucina-10/genética , Ratones , Ratones Endogámicos DBA , Ratones Endogámicos NZB , ARN Mensajero/análisis
11.
J Natl Cancer Inst ; 81(12): 945-8, 1989 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-2733039

RESUMEN

We performed this study to determine whether human mesothelial cells are capable of undergoing neoplastic change in vitro and to observe their interaction with the activated c-Ha-ras (HRAS1) oncogene EJ-ras, which has a role in the development of many malignant human tumors. Mesothelial cells are presumed to be the progenitor cells of malignant mesothelioma, a cancer strongly correlated with asbestos exposure. Previously, we established a non-tumorigenic cell line, MeT-5A, from normal human mesothelial cells after transfection with a plasmid containing the simian virus 40 (SV40) early-region genes. In the present study, we performed transfection of a plasmid containing the EJ-ras gene and the neomycin-resistance gene into these cells and selected a population resistant to G418, a neomycin analogue. Cells from this cell line formed rapidly growing sc tumors in NIH Swiss athymic nude mice, but untransfected with the vector DNA and selected for G418 resistance formed no tumors. The tumors formed by EJ-ras-transfected cells were established in vitro, and cells from these tumor cell lines exhibited a characteristic altered morphology. The cells had the same isoenzyme phenotype as the parent cells, and they expressed the mutant EJ-ras p21 protein. This first demonstration of malignant transformation of human mesothelial cells in vitro may permit molecular analysis of mesothelial carcinogenesis.


Asunto(s)
Transformación Celular Neoplásica/genética , Mesotelioma/genética , Oncogenes , Animales , Línea Celular Transformada , Resistencia a Medicamentos/genética , Gentamicinas/farmacología , Humanos , Mesotelioma/patología , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Transfección
12.
Cancer Res ; 52(1): 218-21, 1992 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-1727381

RESUMEN

The carcinogenicity of certain nickel compounds is well known. We have previously shown that human kidney epithelial cells were immortalized by treatment with Ni(II) and in cooperation with the v-Ha-ras oncogene transformed the cells to acquire tumorigenicity in athymic nude mice. Immunocytochemistry and sequence analysis of DNA from the nickel-immortalized cells revealed abnormal p53 expression and a T----C transition mutation in codon 238. These data are consistent with the hypothesis that Ni(II)-induced mutation in the p53 gene can be involved in the escape from senescence of kidney epithelial cells.


Asunto(s)
Deleción Cromosómica , Cromosomas Humanos Par 17 , Genes p53/efectos de los fármacos , Riñón/efectos de los fármacos , Mutación/genética , Níquel/toxicidad , Línea Celular Transformada , Epitelio/efectos de los fármacos , Genes p53/genética , Humanos
13.
Cancer Res ; 52(9): 2610-5, 1992 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-1568228

RESUMEN

Twenty cell lines from 17 individuals with malignant mesothelioma have been examined for p53 alterations by direct sequencing of genomic DNA, by evaluation of mRNA expression levels, and by immunocytochemical analysis of p53 protein expression in comparison with normal human pleural mesothelial cells. The results of this study show p53 abnormalities in cell lines from 3 individuals. These include 2 point mutations and one null cell line. Interestingly, while both cell lines with point mutations exhibit high levels of p53 protein, normal mesothelial cells as well as 12 of the mesotheliomas evaluated express low but significant levels. In addition, sequencing of K-ras at codons 12, 13, and 61 reveals wild-type sequence in all 20 mesothelioma cell lines. The capacity to induce tumors in athymic nude mice did not correlate with the presence of a p53 mutation or elevated p53 protein levels. These data suggest that neither p53 alteration nor K-ras activation constitutes a critical step in the development of human mesothelioma.


Asunto(s)
Codón/genética , Genes p53/genética , Genes ras/genética , Mesotelioma/genética , Mutación/genética , Animales , Codón/química , Análisis Mutacional de ADN , Humanos , Ratones , Ratones Desnudos , ARN Mensajero/análisis , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/análisis
14.
Cancer Res ; 51(15): 4090-6, 1991 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-1855224

RESUMEN

The p53 tumor suppressor gene is frequently mutated and the K-ras oncogene is occasionally mutated in primary specimens of human lung carcinomas. These mutated genes also cooperate in the immortalization and neoplastic transformation of rodent cells. To determine whether these mutations are necessary for maintenance of the immortalized and/or neoplastically transformed states of human bronchial epithelial cells, the p53 gene and regions of the ras (K-, H-, and N-) genes were sequenced in nine human lung carcinoma cell lines. Detection of p53 mutations by polymerase chain amplification and direct DNA sequencing was corroborated by p53 immunocytochemistry and coimmunoprecipitation of p53 with heat shock protein 70. p53 and ras genes were frequently, but not always, mutated in the carcinoma cell lines. These data are consistent with the hypothesis that multiple genetic changes involving both protooncogenes and tumor suppressor genes occur during lung carcinogenesis.


Asunto(s)
Genes p53/genética , Genes ras/genética , Proteínas de Choque Térmico/metabolismo , Neoplasias Pulmonares/genética , Mutación/genética , Proteína p53 Supresora de Tumor/metabolismo , Secuencia de Bases , Bronquios/citología , Bronquios/fisiología , Transformación Celular Neoplásica/genética , Células Epiteliales , Exones/fisiología , Humanos , Inmunohistoquímica , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Datos de Secuencia Molecular , Pruebas de Precipitina , Unión Proteica , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/genética
15.
Cancer Res ; 51(15): 4102-6, 1991 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-1855226

RESUMEN

Esophageal squamous cell carcinoma (ESC) samples from patients residing in Uruguay and in Normandy, France, where alcoholic beverages and tobacco smoke are major risk factors, were analyzed for point mutations in the p53 tumor suppressor gene. Among 34 tumors (15 from Normandy and 19 from Uruguay) 15 point mutations in the p53 gene that result in amino acid substitutions or chain termination were identified by polymerase chain reaction amplification of exons 5-8 and direct DNA sequencing. Base substitutions in ESC from these high-incidence areas are dispersed over the midregion of the p53 gene. There are differences between ESC and other types of gastrointestinal cancer in the nature of frequent base substitutions. CpG to TpG transitions were far less prevalent in these ESC than in colorectal tumors, whereas G to T transversions, rarely found in colon cancers, were found in one-fourth of the ESC samples. Base substitutions at A:T pairs constitute an important fraction of ESC p53 mutations, in contrast to mutation patterns in most other types of solid tumors. In contrast to the frequent mutation of the p53 gene in these samples, no mutations in the H-, K-, or N-ras genes were found in 16 tumors from Uruguay by direct sequencing of exons in which transforming mutations are known to occur. A previous study on ras mutations in ESC from France was also negative (M. C. Hollstein et al., Cancer Res., 48: 5119-5123, 1988). The role of distinct etiological factors in generating these differences and the potential for linking patient exposure histories with patterns of p53 mutations in high risk populations are considered.


Asunto(s)
Carcinoma de Células Escamosas/genética , Neoplasias Esofágicas/genética , Genes p53/genética , Genes ras/genética , Mutación/genética , Adulto , Anciano , Anciano de 80 o más Años , Secuencia de Bases , Carcinoma de Células Escamosas/epidemiología , Codón/genética , Daño del ADN/genética , Neoplasias Esofágicas/epidemiología , Femenino , Francia/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Uruguay/epidemiología
16.
Cancer Res ; 53(20): 4817-22, 1993 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-8402667

RESUMEN

p53 mutations are common in human lung cancer and frequently generate levels of p53 protein that are detectable by immunohistochemistry. For this reason, p53 protein accumulation is a candidate biomarker, but little is known about its timing or frequency in multistage bronchial carcinogenesis. We studied human lung tissues containing preinvasive squamous neoplasms from 34 donors with and without lung cancer. Nuclear p53 protein was present in 0% of normal mucosas, 6.7% of squamous metaplasias, 29.5% of mild dysplasias, 26.9% of moderate dysplasias, 59.7% of severe dysplasias, 58.5% of carcinomas in situ, 67.5% of microinvasive carcinomas, and 79.5% of invasive tumors. These data indicate that (a) p53 protein accumulates in about 30% of the earliest recognized neoplastic lesions (i.e., mild dysplasia), (b) there is an increasing frequency of p53 protein accumulation starting with mild dysplasia, and (c) p53 protein accumulates infrequently in normal or metaplastic mucosa. In a subset of six patients whose most advanced lesion was carcinoma in situ without evidence of invasive cancer, p53 protein was detected in 0% of normal mucosas, 8.3% of squamous metaplasias, 37.5% of mild dysplasias, 12.5% of moderate dysplasias, 93.8% of severe dysplasias, and 55% of carcinoma in situ lesions. These data show clearly that p53 alterations can occur before invasion and suggest that the frequency is similar to that observed in the full series. Since two-thirds or more of lung cancers have p53 alterations, the timing and frequency of p53 protein accumulation make the p53 tumor suppressor gene an attractive marker for early diagnosis and evaluation of chemoprevention agents.


Asunto(s)
Biomarcadores de Tumor/análisis , Carcinoma in Situ/patología , Carcinoma de Células Escamosas/patología , Neoplasias Pulmonares/patología , Lesiones Precancerosas/patología , Proteína p53 Supresora de Tumor/análisis , Carcinoma in Situ/clasificación , Carcinoma in Situ/metabolismo , Carcinoma de Células Escamosas/clasificación , Carcinoma de Células Escamosas/metabolismo , Núcleo Celular/ultraestructura , Humanos , Inmunohistoquímica , Neoplasias Pulmonares/clasificación , Neoplasias Pulmonares/metabolismo , Membrana Mucosa/patología , Invasividad Neoplásica , Lesiones Precancerosas/clasificación , Lesiones Precancerosas/metabolismo , Proteína p53 Supresora de Tumor/metabolismo
17.
Cancer Res ; 52(21): 6092-7, 1992 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-1394236

RESUMEN

Preinvasive lesions of squamous cell carcinoma are well defined morphologically and provide a model for multistage carcinogenesis. Since alterations in the p53 tumor suppressor gene occur frequently in invasive esophageal squamous cell carcinoma, we examined a set of preinvasive lesions to investigate the timing of p53 mutation. Surgically resected tissues from nine patients with esophageal squamous cell carcinoma contained precursor lesions which had not yet invaded normal tissues. Immunohistochemistry showed high levels of p53 protein in both preinvasive lesions and invasive carcinomas in six cases; sequence analysis of all invasive tumors identified p53 missense mutations in two cases. Preinvasive lesions from both tumors with mutations plus one wild-type tumor were microdissected and sequenced. In one patient there were different mutations in the invasive carcinoma (codon 282, CGGarg > TGGtrp) and a preinvasive lesion (codon 272, GTGval > T/GTGleu/val). In a second case, an invasive carcinoma had a mutation in codon 175 (CGCarg > CAChis), and adjacent preinvasive lesions contained a wild-type sequence. A carcinoma and preinvasive lesion from the third case contained high levels of protein and a wild-type DNA sequence. Therefore, p53 mutation may precede invasion in esophageal carcinogenesis, and multifocal esophageal neoplasms may arise from independent clones of transformed cells. The timing of p53 protein accumulation is favorable for an intermediate biomarker in multistage esophageal carcinogenesis.


Asunto(s)
Carcinoma in Situ/genética , Carcinoma de Células Escamosas/genética , Neoplasias Esofágicas/genética , Genes p53/genética , Mutación/genética , Lesiones Precancerosas/genética , Proteína p53 Supresora de Tumor/metabolismo , Secuencia de Bases , Carcinoma in Situ/metabolismo , Carcinoma in Situ/patología , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patología , Codón/genética , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/patología , Exones/genética , Humanos , Datos de Secuencia Molecular , Lesiones Precancerosas/metabolismo , Lesiones Precancerosas/patología
18.
Oncogene ; 6(10): 1779-84, 1991 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1923503

RESUMEN

A strategy and methods for archival analysis of genetic and protein alterations in the p53 tumor-suppressor gene are presented. The tumor series includes 43 paraffin-embedded esophageal carcinomas from two high-incidence regions in the People's Republic of China. More than half contained elevated p53 protein levels which were detected by a high-titer polyclonal antiserum and a sensitive immunohistochemical method. To estimate the frequency of underlying mutations, DNA was isolated from conventional paraffin sections, amplified by the polymerase chain reaction, and examined by dideoxy termination sequencing. Analysis of exons 5-8 in a subset of 10 tumors revealed mis-sense point mutations in 4 out of 5 immunostain-positive tumors and a mutation encoding a stop codon in 1 of 5 immunostain-negative tumors. In this report of archival material, we conclude that detectable levels of p53 protein correlate closely with the occurrence of mis-sense mutations. Furthermore, these methods render large repositories of paraffin-embedded tumor and non-tumor tissues accessible to analysis. Immunohistochemical screening for elevated protein levels followed by sequence analysis represents an efficient strategy for the evaluation of the p53 mutational spectrum.


Asunto(s)
Adenocarcinoma/genética , Carcinoma de Células Escamosas/genética , Neoplasias Esofágicas/genética , Genes p53/genética , Mutación/genética , Adenocarcinoma/etnología , Secuencia de Aminoácidos , Carcinoma de Células Escamosas/etnología , China , Neoplasias Esofágicas/etnología , Humanos , Datos de Secuencia Molecular
19.
Curr Top Microbiol Immunol ; 194: 117-26, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-7895486

RESUMEN

The molecular lesions of human familial and common B-CLL remain unknown. As an approach to this problem, aged NZB mice with a B cell lymphoproliferative disorder were chosen as a murine model. Three groups of NZB mice (2 months, 6 months and > 18 months) for a total of nineteen were studied. A complete autopsy including a CBC was performed on each mouse. Spleen cells were immunophenotyped and cell cycle analysis was performed. Spleen weight, peritoneal cell counts and absolute lymphocytes counts were all elevated in the oldest group. All mice showed evidence of extramedulary hematopoiesis and the older group showed lymphocytic infiltrates in the lacrymal glands, kidneys, liver and lungs. Two of the seven aged mice had a malignant lymphoma. One was a marginal zone lymphoma and the other a lymphocytic lymphoma. Splenic immunophenotyping showed a loss of T cells with an increase in B cells as the mice age. Cell cycle analysis revealed hyperdiploidy in all of the aged mice with a decrease in the percentage G0G1 cells. This disease appears to involve an absolute lymphocytosis of the peritoneum and the peripheral blood compartment. This is associated with splenic aneuploidy. The infiltration of the spleen by malignant cells of varying morphology is a late event. The aged NZB mouse continues to be a model for human B-CLL.


Asunto(s)
Modelos Animales de Enfermedad , Leucemia Linfocítica Crónica de Células B , Trastornos Linfoproliferativos/genética , Ratones Endogámicos NZB , Envejecimiento , Aneuploidia , Animales , Autopsia , Hematopoyesis Extramedular , Hipergammaglobulinemia/genética , Inmunofenotipificación , Interfase , Recuento de Linfocitos , Trastornos Linfoproliferativos/sangre , Trastornos Linfoproliferativos/patología , Ratones , Tamaño de los Órganos , Especificidad de Órganos , Cavidad Peritoneal/patología , Bazo/patología
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda