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1.
Vet Pathol ; 60(2): 185-189, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36541627

RESUMEN

Sebaceous carcinomas of the human ocular adnexa commonly exhibit pagetoid spread, mutations in tumor-suppressor genes, and protooncogene copy number gain. Sebaceous carcinomas are rarely reported in other species, and while the Meibomian gland (MG) represents the most common ocular adnexal structure of the canine eyelid to develop neoplasia, most are clinically and histologically benign. The objective of this study was to compare molecular features of canine MG carcinomas and adenomas. Two retrospectively identified MG carcinomas were subject to immunohistochemistry and qPCR. When compared with normal glands, MYC was upregulated in benign and malignant MG neoplasms. Aberrant p53 expression was restricted to the nuclei of intraepithelial neoplastic cells in MG carcinomas. Adipophilin expression was diminished in MG neoplasms compared with the normal MG. Our findings, if confirmed in a larger cohort of cases, could suggest that MG oncogenesis in a dog may exhibit similar molecular features as their human counterparts.


Asunto(s)
Adenoma , Carcinoma Basocelular , Enfermedades de los Perros , Neoplasias de las Glándulas Sebáceas , Neoplasias Cutáneas , Humanos , Perros , Animales , Glándulas Tarsales/metabolismo , Glándulas Tarsales/patología , Proteína p53 Supresora de Tumor , Estudios Retrospectivos , Neoplasias de las Glándulas Sebáceas/química , Neoplasias de las Glándulas Sebáceas/metabolismo , Neoplasias de las Glándulas Sebáceas/patología , Neoplasias de las Glándulas Sebáceas/veterinaria , Neoplasias Cutáneas/veterinaria , Carcinoma Basocelular/veterinaria , Transformación Celular Neoplásica , Adenoma/patología , Adenoma/veterinaria , Mutación
2.
Osteoarthritis Cartilage ; 26(12): 1643-1650, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30130590

RESUMEN

OBJECTIVE: The goal of this study was to model the longitudinal progression of knee osteoarthritis (OA) and build a prognostic tool that uses data collected in 1 year to predict disease progression over 8 years. DESIGN: To model OA progression, we used a mixed-effects mixture model and 8-year data from the Osteoarthritis Initiative (OAI)-specifically, joint space width measurements from X-rays and pain scores from the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire. We included 1243 subjects who at enrollment were classified as being at high risk of developing OA based on age, body mass index (BMI), and medical and occupational histories. After clustering subjects based on radiographic and pain progression, we used clinical variables collected within the first year to build least absolute shrinkage and selection (LASSO) regression models for predicting the probabilities of belonging to each cluster. Areas under the receiver operating characteristic curve (AUC) represent predictive performance on held-out data. RESULTS: Based on joint space narrowing, subjects clustered as progressing or non-progressing. Based on pain scores, they clustered as stable, improving, or worsening. Radiographic progression could be predicted with high accuracy (AUC = .86) using data from two visits spanning 1 year, whereas pain progression could be predicted with high accuracy (AUC = .95) using data from a single visit. Joint space narrowing and pain progression were not associated. CONCLUSION: Statistical models for characterizing and predicting OA progression promise to improve clinical trial design and OA prevention efforts in the future.


Asunto(s)
Osteoartritis de la Rodilla/diagnóstico por imagen , Anciano , Análisis por Conglomerados , Progresión de la Enfermedad , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Modelos Estadísticos , Osteoartritis de la Rodilla/complicaciones , Osteoartritis de la Rodilla/patología , Dolor/etiología , Dimensión del Dolor/métodos , Valor Predictivo de las Pruebas , Pronóstico , Radiografía , Índice de Severidad de la Enfermedad
3.
Virchows Arch ; 468(5): 607-17, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26861919

RESUMEN

The prognostic value of phosphatase and tensin homolog (PTEN) loss in prostate cancer has primarily been evaluated by either fluorescence in situ hybridization (FISH) or immunohistochemistry (IHC). Previously, we found that PTEN loss by IHC was associated with increased risk of upgrading from biopsy (Gleason 3 + 3) to prostatectomy (Gleason 7+). Now, using an evaluable subset of 111 patients with adjacent biopsy sections, we analyzed the association between PTEN deletion in cancer and the odds of upgrading by a highly sensitive and specific four-color FISH assay. We also compared the concordance of PTEN loss by IHC and PTEN deletion by FISH. PTEN deletion was found in 27 % (12/45) of upgraded cases compared with 11 % (7/66) of controls (P = 0.03). Cancers with PTEN deletions were more likely to be upgraded than those without deletions (adjusting for age odds ratio = 3.40, 95 % confidence interval 1.14-10.11). With respect to concordance, of 93 biopsies with PTEN protein detected by IHC, 89 (96 %) had no PTEN deletion by FISH, and of 18 biopsies without PTEN protein by IHC, 15 had homozygous or hemizygous PTEN deletion by FISH. Only 4 biopsies of the 93 (4 %) with PTEN protein intact had PTEN deletion by FISH. When the regions of uncertainty in these biopsies were systematically studied by FISH, intra-tumoral variation of PTEN deletion was found, which could account for variation in immunoreactivity. Thus, FISH provides a different approach to determining PTEN loss when IHC is uncertain. Both FISH and IHC are concordant, showing consistent positive associations between PTEN loss and upgrading.


Asunto(s)
Biomarcadores de Tumor/análisis , Hibridación Fluorescente in Situ , Fosfohidrolasa PTEN/metabolismo , Neoplasias de la Próstata/química , Neoplasias de la Próstata/patología , Anciano , Biopsia con Aguja , Humanos , Inmunohistoquímica/métodos , Hibridación Fluorescente in Situ/métodos , Masculino , Persona de Mediana Edad , Prostatectomía/métodos
4.
Prostate Cancer Prostatic Dis ; 16(2): 209-15, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23545904

RESUMEN

BACKGROUND: ERG rearrangements and PTEN (phosphatase and tensin homolog deleted on chromosome 10) loss are two of the most common genetic alterations in prostate cancer. However, there is still significant controversy regarding the order of events of these two changes during the carcinogenic process. We used immunohistochemistry (IHC) to determine ERG and PTEN status, and calculated the fraction of cases with homogeneous/heterogeneous ERG and PTEN staining in a given tumor. METHODS: Using a single standard tissue section from the index tumor from radical prostatectomies (N=77), enriched for relatively high grade and stage tumors, we examined ERG and PTEN status by IHC. We determined whether ERG or PTEN staining was homogeneous (all tumor cells staining positive) or heterogeneous (focal tumor cell staining) in a given tumor focus. RESULTS: Fifty-seven percent (N=44/77) of tumor foci showed ERG positivity, with 93% of these (N=41/44) cases showing homogeneous ERG staining in which all tumor cells stained positively. Fifty-three percent (N=41/77) of tumor foci showed PTEN loss, and of these 66% (N=27/41) showed heterogeneous PTEN loss. In ERG homogeneously positive cases, any PTEN loss occurred in 56% (N=23/41) of cases, and of these 65% (N=15/23) showed heterogeneous loss. In ERG-negative tumors, 51.5% (N=17/33) showed PTEN loss, and of these 64.7% (N=11/17) showed heterogeneous PTEN loss. In a subset of cases, genomic deletions of PTEN were verified by fluorescence in situ hybridization in regions with PTEN protein loss as compared with regions with intact PTEN protein, which did not show PTEN genomic loss. CONCLUSIONS: These results support the concept that PTEN loss tends to occur as a subclonal event within a given established prostatic carcinoma clone after ERG gene fusion. The combination of ERG and PTEN IHC staining can be used as a simple test to ascertain PTEN and ERG gene rearrangement status within a given prostate cancer in either a research or clinical setting.


Asunto(s)
Adenocarcinoma/metabolismo , Fosfohidrolasa PTEN/genética , Neoplasias de la Próstata/metabolismo , Transactivadores/genética , Adenocarcinoma/genética , Adenocarcinoma/patología , Adulto , Anciano , Carcinogénesis/genética , Carcinogénesis/metabolismo , Carcinogénesis/patología , Progresión de la Enfermedad , Eliminación de Gen , Homocigoto , Humanos , Inmunohistoquímica , Pérdida de Heterocigocidad , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Estadificación de Neoplasias , Fusión de Oncogenes , Proteínas de Fusión Oncogénica/genética , Proteínas de Fusión Oncogénica/metabolismo , Fosfohidrolasa PTEN/metabolismo , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/patología , Transactivadores/metabolismo , Regulador Transcripcional ERG
5.
Int J Radiat Biol ; 79(1): 53-60, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12556331

RESUMEN

PURPOSE: The adenovirus E4orf6 34 kDa protein (E4-34k) is known to disrupt V(D)J recombination as a result of its interaction with the catalytic subunit of cellular DNA-dependent protein kinase (DNA-PK(cs)), a major participant in the repair of DNA double-strand breaks (DSB). Previous studies have shown that cells with disrupted DSB repair and V(D)J recombination due to attenuation of DNA-PK(cs) activity exhibit a radiation-sensitive phenotype. It is not known at present whether the E4-34k protein can also modify cellular response to ionizing radiation. In an attempt to develop a novel gene therapy strategy to modify cellular radiation response, we sought to determine if expression of the adenovirus E4-34k protein resulted in sensitization to clinically relevant doses of ionizing radiation. MATERIALS AND METHODS: In order to minimize potential bias resulting from selection procedures, we performed clonogenic survival assays on DU 145 prostate cancer cells, RKO colorectal cancer cells and 293 kidney cells following transient transfection of E4-34k- and/or E1B-55k-expressing plasmids. Western blots and immunohistochemical analyses were used to demonstrate E4-34k expression within transfected cells. FACS sorting was carried out to enrich cells transfected with a plasmid that expresses both E4-34k and enhanced green fluorescent protein. RESULTS: It is shown that E4-34k expression does not affect cellular radiosensitivity of transiently transfected populations of either DU 145 prostate or RKO colon cancer cell lines. Similarly, the radiosensitivity of human embryonic kidney 293 cells, which constitutively express the E1B-55k protein, was also unaffected. The radiosensitivity of DU 145 cells co-transfected with E4-34k- and E1-55K-expressing plasmids was unchanged, suggesting that the adenovirus E1B-55k protein does not augment any effects E4-34k might have on DNA-PK(cs) activity. CONCLUSIONS: The lack of radiosensitization by E4-34k expression is quite intriguing as it is known that E4-34k interaction with DNA-PK(cs) causes disruption of V(D)J recombination, a process dependent on DSB rejoining. These data suggest that for future studies, preferential targeting of DNA-PK(cs) DSB activity will be required to influence cellular radiosensitivity.


Asunto(s)
Proteínas E4 de Adenovirus/fisiología , Proteínas de Unión al ADN , Proteínas Serina-Treonina Quinasas/metabolismo , Tolerancia a Radiación , Proteínas E1B de Adenovirus/fisiología , Supervivencia Celular/efectos de la radiación , Proteína Quinasa Activada por ADN , Genes de Inmunoglobulinas , Humanos , Masculino , Proteínas Nucleares , Recombinación Genética , Transfección , Células Tumorales Cultivadas
6.
J Bone Joint Surg Br ; 83(7): 1050-4, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11603522

RESUMEN

Joint replacement in HIV-positive patients remains uncommon, with most experience gained in patients with haemophilia. We analysed retrospectively the outcome of 102 replacement arthroplasties in 73 HIV-positive patients from eight specialist haemophilia centres. Of these, 91 were primary procedures. The mean age of the patients at surgery was 39 years, and the median follow-up was for five years. The overall rate of deep sepsis was 18.7% for primary procedures and 36.3% for revisions. This is a much higher rate of infection than that seen in normal populations. A total of 44% of infections resolved fully after medical and/or surgical treatment. The benefits of arthroplasty in haemophilic patients are well established but the rates of complications are high. As this large study has demonstrated, high rates of infection occur, but survivorship analysis strongly suggests that most patients already diagnosed with HIV infection at the time of surgery should derive many years of symptomatic relief after a successful joint replacement. Careful counselling and education of both patients and healthcare workers before operation are therefore essential.


Asunto(s)
Seropositividad para VIH/complicaciones , Hemofilia A/complicaciones , Prótesis Articulares/efectos adversos , Infecciones Relacionadas con Prótesis/epidemiología , Infecciones Relacionadas con Prótesis/etiología , Adulto , Seropositividad para VIH/mortalidad , Hemofilia A/mortalidad , Humanos , Persona de Mediana Edad , Infecciones Relacionadas con Prótesis/mortalidad , Infecciones Relacionadas con Prótesis/cirugía , Estudios Retrospectivos , Tasa de Supervivencia
7.
Memory ; 9(1): 39-51, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11315660

RESUMEN

Three experiments were conducted to assess participants' beliefs about potential false memories that might have occurred during free recall tests. An input-output monitoring test was administered that required participants to discriminate between items that were studied and recalled, studied and not recalled, or were entirely new. Critical lures from Roediger and McDermott's (1995) paradigm were inserted into this test. The results demonstrated that participants believed erroneously recalled items were both studied and recalled. The intriguing finding was that unrecalled items were believed to have been studied approximately 80% of the time, and half of those were also believed to have been recalled. This result represents a dual false memory effect in which items were believed to have been studied and also to have been recalled. The ramifications of this new procedure are discussed in terms of proposed experiments that might clarify the genesis of these false memories.


Asunto(s)
Memoria/fisiología , Análisis de Varianza , Señales (Psicología) , Humanos , Recuerdo Mental/fisiología , Pruebas Psicológicas
8.
J Exp Psychol Learn Mem Cogn ; 27(2): 375-83, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11294439

RESUMEN

A number of recent reports have investigated false memories using variants of the Deese-Roediger-McDermott (DRM) paradigm. Because these false memories have been difficult to eliminate, this study investigated whether false recognition could be reduced by incorporating source-monitoring criteria into decision processes. Making claims about the manner in which items were learned should require more careful scrutiny of memories, and therefore false recognition should be minimized with source instructions as compared with old-new recognition instructions. In 3 experiments that varied the combination of sources, false recognition was increased rather than reduced by applying source-monitoring processes. The theoretical implications of these counterintuitive results are discussed in terms of the old-new detection component of source judgments.


Asunto(s)
Atención , Represión Psicológica , Retención en Psicología , Aprendizaje Verbal , Adulto , Aprendizaje por Asociación , Femenino , Humanos , Control Interno-Externo , Masculino , Semántica , Percepción del Habla
9.
J Exp Psychol Learn Mem Cogn ; 26(5): 1160-9, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11009250

RESUMEN

Five experiments were conducted to explore how the character of the retention interval affected event-based prospective memory. According to the canons of retrospective memory, prospective performance should have been worse with increasing delays between intention formation and the time it was appropriate to complete an action. That result did not occur. Rather, prospective memory was better with increasing retention intervals in Experiments 1A, 1B, and 3. In manipulating the nature of the retention interval, the authors found that there were independent contributions of retention interval length and the number of intervening activities, with more activities leading to better prospective memory (Experiments 2 and 3). The identical retention intervals did not improve retrospective memory in Experiment 4. Theoretical explanations for these dissociations between prospective and retrospective memory are considered.


Asunto(s)
Señales (Psicología) , Inhibición Psicológica , Retención en Psicología , Adulto , Femenino , Humanos , Masculino , Recuerdo Mental , Modelos Psicológicos , Factores de Tiempo
10.
Emerg Med Clin North Am ; 18(3): 379-91,v, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10967731

RESUMEN

Hard-tissue and soft-tissue landmarks of the face and oral cavity are introduced. Definitions for anatomic structures are listed, and figures to aid clinical examination are provided. Relevance of these landmarks to examination, diagnosis, and function is made.


Asunto(s)
Cara/anatomía & histología , Boca/anatomía & histología , Dentición , Servicios Médicos de Urgencia , Humanos , Terminología como Asunto
11.
J Exp Psychol Learn Mem Cogn ; 26(6): 1483-98, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11185778

RESUMEN

Previous studies have concluded that recognition memory is immune to disruption from divided attention and therefore is a relatively automatic process (A. Baddeley, V. Lewis, M. Eldridge, & N. Thomson, 1984; F. I. M. Craik, R. Govoni, M. Naveh-Benjamin, & N. D. Anderson, 1996). Because costs have been found on the concurrent task used to divide attention, recognition may nevertheless require some attentional resources (M. Naveh-Benjamin, F. I. M. Craik, J. Guez, & H. Dori, 1998). The present authors used attention-demanding concurrent tasks to demonstrate significant costs on both the concurrent task and recognition memory performance. Decrements in recognition accuracy were found for classes of items that were studied deeply but not for more shallowly learned materials. The present findings suggest that recognition processes can require significant attentional resources when tested under the appropriate conditions. The results are discussed in terms of the requirements both at encoding and at test that are needed to observe dual-task decrements to recognition accuracy.


Asunto(s)
Atención , Memoria , Reconocimiento en Psicología , Adolescente , Adulto , Femenino , Humanos , Masculino , Procesos Mentales , Análisis y Desempeño de Tareas
13.
Mol Biol Cell ; 10(12): 4341-53, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10588662

RESUMEN

We have identified partial loss of function mutations in class VI unconventional myosin, 95F myosin, which results in male sterility. During spermatogenesis the germ line precursor cells undergo mitosis and meiosis to form a bundle of 64 spermatids. The spermatids remain interconnected by cytoplasmic bridges until individualization. The process of individualization involves the formation of a complex of cytoskeletal proteins and membrane, the individualization complex (IC), around the spermatid nuclei. This complex traverses the length of each spermatid resolving the shared membrane into a single membrane enclosing each spermatid. We have determined that 95F myosin is a component of the IC whose function is essential for individualization. In wild-type testes, 95F myosin localizes to the leading edge of the IC. Two independent mutations in 95F myosin reduce the amount of 95F myosin in only a subset of tissues, including the testes. This reduction of 95F myosin causes male sterility as a result of defects in spermatid individualization. Germ line transformation with the 95F myosin heavy chain cDNA rescues the male sterility phenotype. IC movement is aberrant in these 95F myosin mutants, indicating a critical role for 95F myosin in IC movement. This report is the first identification of a component of the IC other than actin. We propose that 95F myosin is a motor that participates in membrane reorganization during individualization.


Asunto(s)
Drosophila/metabolismo , Cadenas Pesadas de Miosina/metabolismo , Espermatogénesis/fisiología , Actinas/metabolismo , Animales , Elementos Transponibles de ADN , Drosophila/genética , Técnica del Anticuerpo Fluorescente , Infertilidad Masculina/genética , Masculino , Mutagénesis Insercional , Mutación , Cadenas Pesadas de Miosina/genética , Fenotipo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Espermatogénesis/genética , Testículo/citología , Testículo/metabolismo
14.
Mem Cognit ; 27(2): 320-7, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10226441

RESUMEN

The intention superiority effect is the finding that intentions to perform an activity are stored in a heightened state of activation. The effect has also been generalized to the finding that once an intention is fulfilled, it is inhibited relative to more neutral material about which no intentionality has been formed. In two experiments, we tested some ecological and naturally occurring situations taken from the literature on prospective memory and demonstrated that they have consistent consequences for the activation level of an intention. In Experiment 1, a constellation of unrelated activities displayed heightened activation prior to completion and displayed inhibition after completion. In Experiment 2, canceling the intention resulted in inhibition just as completing the intention does in this paradigm. The results are discussed in terms of their practical and theoretical importance to theories of prospective memory.


Asunto(s)
Memoria/fisiología , Humanos , Vocabulario
15.
Mem Cognit ; 27(2): 355-63, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10226445

RESUMEN

Three experiments explored how participants solved a very open-ended generative problem-solving task. Previous research has shown that when participants are shown examples, novel creations will tend to conform to features shared across those examples (Smith, Ward, & Schumacher, 1993). We made the shared features of the examples conceptually related to one another. We found that when the features were related to the concept of hostility, participants' creations contained hostile features that were not part of any of the examples. These results suggest that participants will design novel entities to be consistent with emergent properties of examples shown to them. We also found that a mild hostility prime from unscrambling sentences had a similar conceptual effect. Together, the two effects suggest that conceptual priming of generative cognitive tasks will influence the cognitive aspects of the creative process.


Asunto(s)
Solución de Problemas , Análisis de Varianza , Hostilidad , Humanos , Distribución Aleatoria , Habla
16.
Psychon Bull Rev ; 6(1): 117-22, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12199305

RESUMEN

Remember-know judgments reflect the subjective state of awareness that accompanies episodic memory retrieval. We tested an old-new recognition condition, an old-new recognition followed by remember-know judgment condition, and a simultaneous remember-know-new judgment condition. These three conditions were tested for both a short (1-sec) and a long (4.5-sec) study duration. Reassuringly, results from the first two conditions did not differ from each other. Results from the third condition, however, differed from those in the first two conditions at both long and short study durations. Simultaneous consideration of all three alternatives resulted in a markedly liberal response bias, both in recognition detection and in the ascriptions of remember and know judgments. Discussion of the results is framed in terms of the single-process signal detection models that have been proposed to account for these subjective states of awareness.


Asunto(s)
Juicio , Memoria , Reconocimiento en Psicología , Humanos , Distribución Aleatoria , Detección de Señal Psicológica
17.
Memory ; 7(3): 293-308, 1999 May.
Artículo en Inglés | MEDLINE | ID: mdl-10659079

RESUMEN

Three experiments were conducted to investigate the relationship between the credibility of information and later unconscious plagiarism of that information. In each experiment, ideas concerning ways to reduce traffic accidents were presented from a more credible source (traffic planners) and a less credible source (college freshmen). After a distractor task, participants were asked to generate novel ways to reduce traffic accidents. In Experiments 1 and 2, unconscious plagiarism of ideas presented from the more credible source was greater than from the less credible source. In neither experiment was explicit memory for ideas from each source different in tests of source monitoring or free recall. However, the difference in unconscious plagiarism was eliminated in Experiment 3 by having participants generate the implications of ideas at study. The results are discussed in terms of the explicit factors that affect the incidence of unconscious plagiarism.


Asunto(s)
Memoria/fisiología , Plagio , Inconsciente en Psicología , Adulto , Humanos , Juicio , Pruebas Psicológicas
18.
J Exp Psychol Learn Mem Cogn ; 24(5): 1105-20, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9747525

RESUMEN

In the revelation effect, the probability of labeling a target or a lure as "old" on item recognition tests increases if just prior to their recognition judgment, participants first identify a disguised version of the test item. The same occurs with interpolated tasks that occur just prior to a recognition judgment if the task shares constituents with the test items. One explanation of this test bias is an increased feeling of familiarity that comes from the identification stage preceding the recognition judgment (e.g., D. C. LeCompte, 1995; C. R. Lou, 1993). This study's finding in 4 experiments that 2-alternative forced-choice recognition either yields no effects of revelation or an "antirevelation" effect, even when both items were studied or nonstudied, is incongruent with this explanation. The authors argue that revelation decrements familiarity, and this results in a more liberal criterion shift. They also argue that their theory is more consistent with previous empirical data.


Asunto(s)
Conducta de Elección/fisiología , Memoria/fisiología , Humanos
19.
Proc Natl Acad Sci U S A ; 95(20): 12022-7, 1998 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-9751783

RESUMEN

A class of high-affinity inhibitors is disclosed that selectively target and irreversibly inactivate the epidermal growth factor receptor tyrosine kinase through specific, covalent modification of a cysteine residue present in the ATP binding pocket. A series of experiments employing MS, molecular modeling, site-directed mutagenesis, and 14C-labeling studies in viable cells unequivocally demonstrate that these compounds selectively bind to the catalytic domain of the epidermal growth factor receptor with a 1:1 stoichiometry and alkylate Cys-773. While the compounds are essentially nonreactive in solution, they are subject to rapid nucleophilic attack by this particular amino acid when bound in the ATP pocket. The molecular orientation and positioning of the acrylamide group in these inhibitors in relation to Cys-773 entirely support these results as determined from docking experiments in a homology-built molecular model of the ATP site. Evidence is also presented to indicate that the compounds interact in an analogous fashion with erbB2 but have no activity against the other receptor tyrosine kinases or intracellular tyrosine kinases that were tested in this study. Finally, a direct comparison between 6-acrylamido-4-anilinoquinazoline and an equally potent but reversible analog shows that the irreversible inhibitor has far superior in vivo antitumor activity in a human epidermoid carcinoma xenograft model with no overt toxicity at therapeutically active doses. The activity profile for this compound is prototypical of a generation of tyrosine kinase inhibitors with great promise for therapeutic significance in the treatment of proliferative disease.


Asunto(s)
Inhibidores Enzimáticos/farmacología , Receptores ErbB/antagonistas & inhibidores , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Quinazolinas/farmacología , Receptor ErbB-2/antagonistas & inhibidores , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Sitios de Unión/genética , Línea Celular , Cisteína/química , Inhibidores Enzimáticos/química , Receptores ErbB/química , Receptores ErbB/genética , Humanos , Ratones , Ratones Desnudos , Modelos Moleculares , Mutagénesis Sitio-Dirigida , Trasplante de Neoplasias , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/metabolismo , Conformación Proteica , Proteínas Tirosina Quinasas/química , Proteínas Tirosina Quinasas/genética , Quinazolinas/química , Receptor ErbB-2/química , Receptor ErbB-2/genética , Proteínas Recombinantes de Fusión/antagonistas & inhibidores , Proteínas Recombinantes de Fusión/genética , Trasplante Heterólogo , Células Tumorales Cultivadas
20.
Mem Cognit ; 26(4): 633-43, 1998 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9701955

RESUMEN

Prospective memory, remembering to carry out one's planned activities, was investigated using a naturalistic paradigm. Three experiments, with a total of 405 participants, were conducted. The goal was to demonstrate that the cognitive processing underlying successful everyday prospective remembering involves components other than mere "memory." Those components are probably best represented as individual differences in various cognitive capacities. More specifically, metamemory, attentional capacities, and planning processes that reprioritize intentions according to the demands of everyday life may determine how people actually accomplish the plans they establish for themselves. The results of these experiments suggest that researchers interested in the topic will have to contend with a multidimensional set of factors before any comprehensive understanding of prospective remembering can be realized.


Asunto(s)
Atención , Objetivos , Memoria/fisiología , Adulto , Análisis de Varianza , Atención/fisiología , Humanos , Responsabilidad Social , Volición/fisiología
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