Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
1.
Curr Oncol ; 21(2): e179-85, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24764702

RESUMEN

BACKGROUND: The unmet needs of cancer survivors in rural, remote, and aboriginal communities are largely unexplored. We explored potential differences between rural survivors (rss) in 4 general population (gp) and 4 First Nations (fn) communities. METHODS: We approached 4 gp and 4 fn rs communities to participate in a mixed-methods project. Participants completed the Hospital Anxiety and Depression Scale (hads) and the Survivor Unmet Needs Survey (suns) and provided demographic information. Each question on the suns can be scored from 0 to 4, with 0 representing "no unmet need" and 4 representing "very high unmet need." A directed approach to content analysis of focus group and interview data was used to triangulate the hads and suns results. RESULTS: We prospectively accrued 23 fn rss and 56 gp rss for this study. More fn rss had borderline or abnormal anxiety (5% vs. 21%, p = 0.02). Compared with gp rss, fn rss had higher unmet needs scores in all categories: Information (2.29 vs. 0.8, p < 0.001), Work and Financial (1.66 vs. 0.5, p < 0.001), Access and Continuity of Health Care (1.83 vs. 0.44, p < 0.001), Coping and Sharing (2.22 vs. 0.62, p < 0.001), and Emotional (2.12 vs. 0.63, p < 0.001). The qualitative findings provided examples and insight into the unmet needs experienced by rss. CONCLUSIONS: First Nations rss had significantly higher anxiety and unmet needs compared with their gp rs counterparts. In addition, different qualitative themes were identified in the groups. Our findings support the development of tailored approaches to survivorship for these populations.

2.
J Mol Endocrinol ; 48(1): 25-36, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22052941

RESUMEN

The hypothesis that levonorgestrel (LNG) used as an emergency contraceptive interferes with endometrial receptivity remains unproven. We compared the endometrial gene expression profile during the receptive period after administering a single dose of LNG 1.5 mg or placebo on day 1 of the luteal phase. An endometrial biopsy was done on day LH+7 or LH+8 and samples were taken from seven volunteers, each one contributing with one cycle treated with placebo and another with LNG. The expression of 20 383 genes was determined using cDNA microarrays. Real-time RT-PCR was used 1) to confirm the differences found in DNA microarray analysis and 2) to determine the effect of LNG on transcript levels of C3, C4BPα, COX2, MAOA, S100A4, and SERPINB9, known to be upregulated during receptivity, and on cPLA2α, JAK1, JNK1, CTSL1, and GSTP1, known to respond to mifepristone. Additional endometrial biopsies were done during the pre-receptive (LH+3) and receptive (LH+7) period and samples were taken from eight untreated volunteers in order to determine the changes associated with acquisition of receptivity of 14 genes. Mean levels of PAEP, TGM2, CLU, IGF2, and IL6ST mRNAs increased after administering LNG while those of HGD, SAT1, EVA1, LOC90133, ANXA1, SLC25A29, CYB5A, CRIP1, and SLC39A14 decreased. Except for the level of ANXA1 transcript, all changes remained within the range observed in untreated controls, and none of the transcripts responding to mifepristone changed in response to LNG. Post-ovulatory administration of LNG caused minimal changes in gene expression profiling during the receptive period. Neither the magnitude nor the nature or direction of the changes endorses the hypothesis that LNG interferes with endometrial receptivity.


Asunto(s)
Anticonceptivos Femeninos/farmacología , Endometrio/efectos de los fármacos , Endometrio/metabolismo , Perfilación de la Expresión Génica , Levonorgestrel/farmacología , Fase Luteínica/efectos de los fármacos , Fase Luteínica/genética , Anticonceptivos Femeninos/administración & dosificación , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Levonorgestrel/administración & dosificación , Ciclo Menstrual/efectos de los fármacos , Ciclo Menstrual/fisiología , Mifepristona/farmacología , Progesterona/metabolismo , Reproducibilidad de los Resultados , Transcriptoma/efectos de los fármacos
3.
Mol Hum Reprod ; 12(12): 749-54, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17020906

RESUMEN

Successful implantation depends both on the quality of the embryo and on the endometrial receptivity. The latter depends on progesterone-induced changes in gene expression, a process that has been characterized by microarray analysis. One of the genes whose transcription appears to be enhanced during the receptive period is monoamine oxidase A (MAO-A). Our first objective was to confirm the increased expression of MAO-A in the endometrium during the receptive phase of spontaneous normal cycles using real time PCR and immunofluorescence. The second objective was to examine the endometrial expression of MAO-A during the receptive phase induced by exogenous estradiol (E(2)) and progesterone in patients whose endometrium was shown to have been either receptive or non-receptive to embryo implantation in repeated cycles of oocyte donation. Results showed that MAO-A transcript levels increased between the pre-receptive (LH+3) and receptive phase (LH+7) in all spontaneous cycles examined, with a median increase of 25-fold. Immunofluorescent labelling demonstrated MAO-A localization to the glandular and luminal epithelium with an increasing positive score between LH+3 and LH+7. Conversely, prior failure of embryo implantation was associated with a 29-fold decrease in MAO-A mRNA levels and a substantial reduction in MAO-A protein immunofluorescent label score. These results show a strong association between endometrial receptivity and MAO-A expression in the endometrial epithelium, suggesting an important role for this enzyme in normal implantation.


Asunto(s)
Implantación del Embrión/fisiología , Pérdida del Embrión/etiología , Endometrio/enzimología , Infertilidad Femenina/enzimología , Monoaminooxidasa/deficiencia , Donación de Oocito , Adulto , Inducción Enzimática , Células Epiteliales/enzimología , Estradiol/farmacología , Femenino , Humanos , Infertilidad Femenina/fisiopatología , Fase Luteínica , Monoaminooxidasa/biosíntesis , Monoaminooxidasa/genética , Monoaminooxidasa/fisiología , Inducción de la Ovulación , Progesterona/farmacología , ARN Mensajero/biosíntesis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células del Estroma/enzimología
5.
J Biol Chem ; 274(43): 30459-67, 1999 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-10521425

RESUMEN

Glucagon-like peptide-2 (GLP-2) promotes the expansion of the intestinal epithelium through stimulation of the GLP-2 receptor, a recently identified member of the glucagon-secretin G protein-coupled receptor superfamily. Although activation of G protein-coupled receptors may lead to stimulation of cell growth, the mechanisms transducing the GLP-2 signal to mitogenic proliferation remain unknown. We now report studies of GLP-2R signaling in baby hamster kidney (BHK) cells expressing a transfected rat GLP-2 receptor (BHK-GLP-2R cells). GLP-2, but not glucagon or GLP-1, increased the levels of cAMP and activated both cAMP-response element- and AP-1-dependent transcriptional activity in a dose-dependent manner. The activation of AP-1-luciferase activity was protein kinase A (PKA) -dependent and markedly diminished in the presence of a dominant negative inhibitor of PKA. Although GLP-2 stimulated the expression of c-fos, c-jun, junB, and zif268, and transiently increased p70 S6 kinase in quiescent BHK-GLP-2R cells, GLP-2 also inhibited extracellular signal-regulated kinase 1/2 and reduced serum-stimulated Elk-1 activity. Furthermore, no rise in intracellular calcium was observed following GLP-2 exposure in BHK-GLP-2R cells. Although GLP-2 stimulated both cAMP accumulation and cell proliferation, 8-bromo-cyclic AMP alone did not promote cell proliferation. These findings suggest that the GLP-2R may be coupled to activation of mitogenic signaling in heterologous cell types independent of PKA via as yet unidentified downstream mediators of GLP-2 action in vivo.


Asunto(s)
Péptidos/farmacología , Proteínas Serina-Treonina Quinasas , Receptores de Glucagón/fisiología , Transducción de Señal/fisiología , Animales , División Celular , Línea Celular , Cricetinae , AMP Cíclico/metabolismo , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Fibroblastos , Hormonas Gastrointestinales/farmacología , Hormonas Gastrointestinales/fisiología , Glucagón/farmacología , Péptido 1 Similar al Glucagón , Péptido 2 Similar al Glucagón , Receptor del Péptido 1 Similar al Glucagón , Riñón , Luciferasas/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Fragmentos de Péptidos/farmacología , Péptidos/fisiología , Fosforilación , Precursores de Proteínas/farmacología , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-akt , Ratas , Receptores de Glucagón/genética , Proteínas Recombinantes/metabolismo , Factor de Transcripción AP-1/metabolismo , Transcripción Genética , Transfección
6.
Nurs Manage ; 30(2): 51-3, 1999 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10188515

RESUMEN

Cancer patients receive multimodal therapy and treatments on an ongoing basis in free-standing cancer centers, infusion centers, and oncology offices and at home. To serve those who require unscheduled evaluation for treatment effects, one hospital developed a program to receive those visits on an inpatient cancer unit.


Asunto(s)
Citas y Horarios , Servicios Médicos de Urgencia/organización & administración , Personal de Enfermería en Hospital/organización & administración , Enfermería Oncológica/organización & administración , Servicio Ambulatorio en Hospital/organización & administración , Humanos , Enfermeras Administradoras/organización & administración
7.
Proc Natl Acad Sci U S A ; 96(4): 1569-73, 1999 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-9990065

RESUMEN

Glucagon-like peptide 2 (GLP-2) is a 33-aa proglucagon-derived peptide produced by intestinal enteroendocrine cells. GLP-2 stimulates intestinal growth and up-regulates villus height in the small intestine, concomitant with increased crypt cell proliferation and decreased enterocyte apoptosis. Moreover, GLP-2 prevents intestinal hypoplasia resulting from total parenteral nutrition. However, the mechanism underlying these actions has remained unclear. Here we report the cloning and characterization of cDNAs encoding rat and human GLP-2 receptors (GLP-2R), a G protein-coupled receptor superfamily member expressed in the gut and closely related to the glucagon and GLP-1 receptors. The human GLP-2R gene maps to chromosome 17p13.3. Cells expressing the GLP-2R responded to GLP-2, but not GLP-1 or related peptides, with increased cAMP production (EC50 = 0.58 nM) and displayed saturable high-affinity radioligand binding (Kd = 0.57 nM), which could be displaced by synthetic rat GLP-2 (Ki = 0.06 nM). GLP-2 analogs that activated GLP-2R signal transduction in vitro displayed intestinotrophic activity in vivo. These results strongly suggest that GLP-2, like glucagon and GLP-1, exerts its actions through a distinct and specific novel receptor expressed in its principal target tissue, the gastrointestinal tract.


Asunto(s)
Proteínas de Unión al GTP/metabolismo , Péptidos/fisiología , Receptores de Glucagón/fisiología , Secuencia de Aminoácidos , Animales , Encéfalo/metabolismo , Células COS , Clonación Molecular , AMP Cíclico/metabolismo , Biblioteca de Genes , Péptido 1 Similar al Glucagón , Péptido 2 Similar al Glucagón , Receptor del Péptido 1 Similar al Glucagón , Humanos , Mucosa Intestinal/metabolismo , Cinética , Datos de Secuencia Molecular , Especificidad de Órganos , Fragmentos de Péptidos/farmacología , Péptidos/farmacología , Ratas , Receptores de Glucagón/química , Receptores de Glucagón/genética , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Transducción de Señal , Relación Estructura-Actividad , Transfección
8.
Genomics ; 44(3): 253-65, 1997 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-9325046

RESUMEN

Histones are thought to play a key role in regulating gene expression at the level of DNA packaging. Recent evidence suggests that transcriptional activation requires competition of transcription factors with histones for binding to regulatory regions and that there may be several mechanisms by which this is achieved. We have characterized a human nucleosome assembly protein, NAP-2, previously identified by positional cloning at 11p15.5, a region implicated in several disease processes including Wilms tumor (WT) etiology. The deduced amino acid sequence of NAP-2 indicates that it encodes a protein with a potential nuclear localization motif and two clusters of highly acidic residues. Functional analysis of recombinant NAP-2 protein purified from Escherichia coli demonstrates that this protein can interact with both core and linker histones. We demonstrate that recombinant NAP-2 can transfer histones onto naked DNA templates. Deletion mutagenesis of NAP-2 demonstrates that both NH3- and COOH-terminal domains are required for histone transfer activity. Subcellular localization studies of NAP-2 indicate that it can shuttle between the cytoplasm and the nucleus, suggesting a role as a histone chaperone. Given the potential role of the human NAP-2 gene (HGMW-approved symbol NAP1L4) in WT etiology, we have elucidated the exon/intron structure of this gene and have analyzed the mutational status of NAP-2 in sporadic WTs. Our results, coupled with tumor suppression assays in G401 WT cells, do not support a role for NAP-2 in the etiology of WT. A putative role for NAP-2 in regulating cellular differentiation is discussed.


Asunto(s)
Histonas/fisiología , Chaperonas Moleculares/fisiología , Proteínas Nucleares/fisiología , Nucleosomas/fisiología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , ADN Complementario/aislamiento & purificación , Proteínas de Unión al ADN , Técnicas de Transferencia de Gen , Histonas/genética , Humanos , Ratones , Ratones Desnudos , Chaperonas Moleculares/genética , Datos de Secuencia Molecular , Proteínas Nucleares/química , Proteínas Nucleares/genética , Nucleosomas/química , Nucleosomas/genética , Unión Proteica/genética , Proteínas Recombinantes/química , Fracciones Subcelulares/química , Tumor de Wilms/genética
9.
Genomics ; 40(2): 267-76, 1997 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-9119394

RESUMEN

We have constructed YAC, PAC, and cosmid contigs in the ataxia-telangiectasia gene region and used the assembled clones to isolate expressed sequences by exon trapping and hybridization selection. In the interval between D11S1819 and D11S2029, exons and cDNAs for potentially 13 different genes were identified. Three of these genes, F37, K28, and 6.82, are large novel genes expressed in a variety of different tissues. K28 shows sequence homology to the Rab GTP binding protein family and gene 6.82 homology to the rabbit vasopressin activated calcium mobilizing receptor, while gene F37 has no homology to any known sequence in the database. Three further clones, exon 6.41 and cDNAs K22 and E74, from the interval between D11S1819 and D11S2029, appear to be expressed endogenous retrovirus sequences. The fourth large novel genes, E14, together with two further possible novel genes, E13 and E3, was identified from exons and cDNAs in the more telomeric 300-kb interval between markers D11S2029 and D11S2179. These are in addition to the genes for mitochondrial acetoacetyl-CoA-acetyltransferase (ACAT) and the ATM gene in the same region. Genes E3, E13, and E14 do not show homology to any known genes. K28, 6.82, ACAT, and ATM all appear to have the same transcriptional orientation toward the telomere.


Asunto(s)
Ataxia Telangiectasia/genética , Mapeo Cromosómico/métodos , Cromosomas Humanos Par 11/genética , Proteínas Serina-Treonina Quinasas , Proteínas/genética , Transcripción Genética/genética , Acetil-CoA C-Acetiltransferasa/genética , Secuencia de Aminoácidos , Proteínas de la Ataxia Telangiectasia Mutada , Proteínas de Ciclo Celular , ADN Complementario/genética , Proteínas de Unión al ADN , Exones/genética , Proteínas de Unión al GTP/genética , Humanos , Datos de Secuencia Molecular , Especificidad de Órganos , ARN Mensajero/análisis , ARN Mensajero/genética , Retroviridae/genética , Homología de Secuencia de Aminoácido , Proteínas Supresoras de Tumor
10.
Somat Cell Mol Genet ; 22(5): 425-31, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9039851

RESUMEN

Several human Mendelian diseases, including the long-QT syndrome, malignant hyperthermia, and episodic ataxia/myokymia syndrome, have recently been demonstrated to be due to mutations in ion channel genes. Systematic mapping of ion channel genes may therefore reveal candidates for other heritable disorders. In this study, the GenBank and dbEST databases were used to identify members of several ion channel families (voltage-gated calcium and sodium, cardiac chloride, and all classes of potassium channels). Genes and ESTs without prior map localization were identified based on GDB and OWL database information and 15 genes and ESTs were selected for mapping. Of these 15, only the serotonin receptor 5HT3R had been previously mapped to a chromosome. A somatic cell hybrid panel (SCH) was screened with an STS from each gene and, if necessary the results verified by a second SCH panel. For three ESTs, rodent derived PCR products of the same size as the human STS precluded SCH mapping. For these three, human P1 clones were isolated and the genomic location was determined by metaphase FISH. These genes and ESTs can now be further evaluated as candidate genes for inherited cardiac, neuromuscular and psychiatric disorders mapped to these chromosomes. Furthermore, the ESTs developed in this study can be used to isolate genomic clones, enabling the determination of each transcript's genomic structure and physical map location. This approach may also be applicable to other gene families and may aid in the identification of candidate genes for groups of related heritable disorders.


Asunto(s)
Canales de Cloruro/genética , Mapeo Cromosómico , Canales de Potasio/genética , Animales , Cromosomas Humanos , Humanos , Células Híbridas , Datos de Secuencia Molecular , Receptores de Serotonina/genética , Lugares Marcados de Secuencia
11.
Genomics ; 35(2): 353-60, 1996 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-8661149

RESUMEN

A contiguous physical map was constructed from the Harvey ras-1 (HRAS1) gene to the 11p telomere. The contig spans approximately 500 kb and is minimally composed of a telomere-containing YAC and P1 and cosmid clones. Included in the contig are 11 sequence-tagged sites derived from P1 and cosmid ends. Three genes were placed on the contig in the following order: telomere-ribonuclease/angiogenin inhibitor (RNH)-Harvey ras-1 (HRAS1)-HRAS1-related complex (HRC). Two novel tetranucleotide repeats (heterozygosity of 66 and 68%) and a complex CA repeat (heterozygosity of 78%) were isolated and characterized.


Asunto(s)
Cromosomas Humanos Par 11 , Genes ras , Telómero , Secuencia de Bases , Mapeo Cromosómico , Cromosomas Artificiales de Levadura , Repeticiones de Dinucleótido , Tamización de Portadores Genéticos , Marcadores Genéticos , Humanos , Datos de Secuencia Molecular , Polimorfismo Genético , Técnica del ADN Polimorfo Amplificado Aleatorio
12.
Leukemia ; 9(11): 1812-7, 1995 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7475267

RESUMEN

Recurrent chromosome translocations involving 11p13 and 14q11 are found in 5-10% of cases of T-ALL. The gene involved in the translocation on chromosome 14 is the T cell antigen receptor alpha or delta. The putative oncogene on chromosome 11 is rhombotin 2 (RBTN2)/translocated in T cell gene 2 (ttg-2), a member of the LIM family of proteins. In this paper we characterize a cell line KOPT-K1 that has a t(11;14)(p13;q11). The breakpoint on chromosome 11 involves an Alu-rich region with the break occurring between two Alu sequences on chromosome 11. In addition, approximately 70 bases from the break on chromosome 11 is a tetranucleotide repeat. Whether either of these structures played a role in the translocation is not known. No heptamer or nonamer sequences, implicated in other rearrangements were found near the breakpoint. The breakpoint on chromosome 11 maps more centromeric than previous translocations of this region. Despite this the RBTN2 gene is highly expressed in KOPT-K1. This cell line will be useful for investigating the role of RBTN2 in leukemogenesis and the mechanism by which the translocation alters the expression of RBTN2.


Asunto(s)
Cromosomas Humanos Par 11 , Receptores de Antígenos de Linfocitos T alfa-beta/genética , Factores de Transcripción/genética , Secuencia de Bases , Cromosomas Humanos Par 14 , Cartilla de ADN/química , Proteínas de Unión al ADN , Expresión Génica , Reordenamiento Génico de la Cadena delta de los Receptores de Antígenos de los Linfocitos T , Reordenamiento Génico de la Cadena gamma de los Receptores de Antígenos de los Linfocitos T/genética , Genes , Humanos , Proteínas con Dominio LIM , Datos de Secuencia Molecular , Proteínas Oncogénicas , ARN Mensajero/genética , Secuencias Repetitivas de Ácidos Nucleicos , Mapeo Restrictivo , Translocación Genética , Células Tumorales Cultivadas
13.
Mol Cell Biol ; 10(7): 3307-13, 1990 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-1694008

RESUMEN

The Friend erythroleukemia virus complex contains no cell-derived oncogene. Transformation by this virus may therefore involve mutations affecting cellular gene expression. We provide evidence that inactivating mutations of the cellular p53 gene are a common feature in Friend virus-induced malignancy, consistent with an antioncogene role for p53 in this disease. We have shown that frequent rearrangements of the p53 gene cause loss of expression or synthesis of truncated proteins, whereas overexpression of p53 protein is seen in other Friend cell lines. We now demonstrate that p53 expression in the latter cells is also abnormal, as a result of missense mutations in regions encoding highly conserved amino acids. Three of these aberrant alleles obtained from cells from different mice were cloned and found to function as dominant oncogenes in gene transfer assays, supporting the view that certain naturally occurring missense mutations in p53 confer a dominant negative phenotype on the encoded protein.


Asunto(s)
Transformación Celular Neoplásica , Virus de la Leucemia Murina de Friend/genética , Genes Dominantes , Proteínas Nucleares/genética , Proteínas Oncogénicas/genética , Fosfoproteínas/genética , Alelos , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Células Cultivadas , Clonación Molecular , Embrión de Mamíferos , Epítopos/análisis , Amplificación de Genes , Leucemia Eritroblástica Aguda/microbiología , Leucemia Experimental/microbiología , Datos de Secuencia Molecular , Sondas de Oligonucleótidos , Proteínas Oncogénicas/análisis , Proteínas Oncogénicas/inmunología , Fosfoproteínas/análisis , Fosfoproteínas/inmunología , ARN/genética , ARN sin Sentido , ARN Mensajero/antagonistas & inhibidores , Ratas , Ratas Endogámicas F344 , Ribonucleasas , Proteína p53 Supresora de Tumor
14.
Oncogene ; 2(6): 621-4, 1988 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-3290808

RESUMEN

We have investigated a mutation in the p53 gene leading to expression of a truncated 46,000-dalton protein in a Friend virus-induced erythroleukemia cell line. cDNA sequence analysis revealed a deletion of nucleotide sequences in exon 7 and part of exon 8; 17 additional nucleotides, derived from intron 6, were present in the cDNA and served to maintain the reading frame of the encoded protein. Comparison with p53 protein from other species indicated that the region of the molecule missing in p46 included a highly conserved region. In addition, p46 failed to bind SV40 large T antigen in vitro under conditions which promoted binding of p53 to large T. It seems likely, therefore, that an important functional property of p53 may be affected by the mutation.


Asunto(s)
Leucemia Eritroblástica Aguda/genética , Proteínas de Neoplasias/genética , Fosfoproteínas/genética , Secuencia de Aminoácidos , Animales , Antígenos Transformadores de Poliomavirus/metabolismo , Línea Celular , Deleción Cromosómica , ADN de Neoplasias/genética , Virus de la Leucemia Murina de Friend , Ratones , Datos de Secuencia Molecular , Proteínas de Neoplasias/metabolismo , Fosfoproteínas/metabolismo , ARN Mensajero/genética , ARN Neoplásico/genética , Proteína p53 Supresora de Tumor
15.
Cell Tissue Res ; 249(1): 145-50, 1987 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-3304643

RESUMEN

The distribution of vasoactive intestinal polypeptide-immunoreactive (VIP-IR) neurons in the lower medulla oblongata and the spinal cord has been analyzed in guinea pigs. This study includes results obtained by colchicine treatment and transection experiments. In the spinal cord, numerous VIP-IR varicosities were observed in the substantia gelatinosa of the columna dorsalis; some were also found in the substantia intermedia and the columna anterior. The spinal VIP-IR nerve fibers were mainly of intraspinal origin and oriented segmentally. VIP-IR nuclei in the spinal cord extended dorsally into corresponding regions of the caudal medulla oblongata, namely from the substantia intermedia medialis and lateralis into the vagus-solitarius complex and from the nucleus spinalis lateralis into the area of the nucleus reticularis lateralis. Additional VIP-IR perikarya were observed in the pars caudalis of the nucleus spinalis nervi trigemini. The VIP-IR nuclei within the caudal medulla oblongata probably form a continuous system with those localized within the spinal cord. They may be involved functionally in the modulation of cardiovascular and respiratory regulation in the guinea pig.


Asunto(s)
Bulbo Raquídeo/análisis , Médula Espinal/anatomía & histología , Péptido Intestinal Vasoactivo/análisis , Animales , Colchicina/farmacología , Femenino , Cobayas , Técnicas para Inmunoenzimas , Masculino , Bulbo Raquídeo/citología , Médula Espinal/citología , Médula Espinal/efectos de los fármacos
16.
Mol Cell Biol ; 7(2): 847-53, 1987 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-3547084

RESUMEN

The p53 gene is rearranged in an erythroleukemic cell line (DP15-2) transformed by Friend retrovirus. Here, we characterize the mutation and identify a deletion of approximately equal to 3.0 kilobases that removes exon 2 coding sequences. The gene is expressed in DP15-2 cells and results in synthesis of a 44,000-dalton protein that is missing the N-terminal amino acid residues of p53. The truncated protein is unusually stable and accumulates to high levels intracellularly. Moreover, it appears to have undergone a change in conformation as revealed by epitope mapping studies. This study represents the first description of an altered p53 gene product arising by mutation during neoplastic progression and identifies a region in the p53 protein molecule that plays a role in determining p53 stability in vivo.


Asunto(s)
Leucemia Eritroblástica Aguda/genética , Proteínas de Neoplasias/genética , Fosfoproteínas/genética , Proto-Oncogenes , Animales , Anticuerpos Monoclonales , Secuencia de Bases , Deleción Cromosómica , ADN de Neoplasias/genética , Virus de la Leucemia Murina de Friend , Regulación de la Expresión Génica , Ratones , Peso Molecular , Proteínas de Neoplasias/inmunología , Fosfoproteínas/inmunología , Proteína p53 Supresora de Tumor
17.
Dev Biol ; 104(2): 484-8, 1984 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-6086431

RESUMEN

The accumulation of DNA strand breaks and activation of ADP-ribosyltransferase (ADPRT) have recently been associated with cellular differentiation. Murine erythroleukemia (MEL) cells undergo erythropoietic differentiation when exposed to dimethyl sulfoxide (Me2SO) and several studies have suggested that DNA strand scission induced by this agent is a prerequisite for expression of the differentiated phenotype. Me2SO induction of MEL cells has also been associated with increases in ADPRT activity in one study, but not in another. We have monitored the effects of Me2SO on DNA strand breaks in preformed and replicating MEL cell DNA. The results clearly demonstrate that DNA fragmentation is not detectable during Me2SO induction of MEL differentiation, even in the presence of 3-aminobenzamide, an inhibitor of ADPRT. Further, these results are consistent with an absence of detectable changes in both endogenous and total potential ADPRT activity during Me2SO-induced MEL differentiation. These findings would argue against Me2SO induction of DNA strand scission and ADPRT in MEL cells undergoing differentiation.


Asunto(s)
Diferenciación Celular , Leucemia Experimental/fisiopatología , Nucleotidiltransferasas/metabolismo , Animales , Benzamidas/farmacología , Diferenciación Celular/efectos de los fármacos , Replicación del ADN/efectos de los fármacos , Dimetilsulfóxido/farmacología , Eritropoyesis/efectos de los fármacos , Cinética , Leucemia Experimental/enzimología , Ratones , Poli(ADP-Ribosa) Polimerasas
18.
Blood ; 64(1): 54-8, 1984 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-6587917

RESUMEN

Cytosine arabinoside (Ara-C) is the most effective agent in the treatment of acute myelogenous leukemia. This agent incorporates in leukemic cell DNA, and the extent of this incorporation correlates with loss of clonogenic survival. The incorporated Ara-C residue behaves as a relative DNA chain terminator, and the extent of (Ara-C)DNA formation correlates with inhibition of DNA synthesis. The incorporation of Ara-C into DNA requires the formation of Ara-CTP, and previous measurements of this metabolite have also been correlated with cytotoxicity. Because it is clinically relevant to define biochemical parameters predictive of Ara-C cytotoxicity, the present studies were undertaken to determine the relationship among Ara-CTP pools, formation of (Ara-C)DNA, and loss of clonogenic survival. The results demonstrate that the incorporation of Ara-C into DNA is the single most powerful predictor of cell lethality. Furthermore, although there is a correlation between Ara-CTP pools or continuous cellular exposure to Ara-CTP and cell kill, these relationships are less significant than that obtained with formation of (Ara-C)DNA. The extent of Ara-C incorporation into DNA can be predicted by the product of the Ara-CTP level and time (T), thus supporting the concept that Ara-C incorporation is dependent on continuous exposure to the triphosphate metabolite. These findings support the formation of (Ara-C)DNA as a highly predictive parameter of lethal cellular events.


Asunto(s)
Citarabina/metabolismo , Leucemia Mieloide Aguda/tratamiento farmacológico , Trifosfato de Arabinofuranosil Citosina/biosíntesis , Trifosfato de Arabinofuranosil Citosina/toxicidad , Supervivencia Celular , Citarabina/uso terapéutico , ADN/antagonistas & inhibidores , Humanos , Ensayo de Tumor de Célula Madre
19.
Mol Pharmacol ; 26(1): 128-34, 1984 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-6431261

RESUMEN

1-beta-D-Arabinofuranosylcytosine (ara-C) incorporates into DNA, and the extent of this incorporation correlates significantly with inhibition of DNA synthesis. The incorporated ara-C residue provides a poor primer terminus for further chain elongation. There is a highly significant relationship between formation of (ara-C) DNA and loss of clonogenic survival. The present studies confirm that incorporation of ara-C into DNA, and not the competitive inhibition of DNA polymerase, is responsible for inducing lethal cellular events. The results also demonstrate that the incorporated ara-C residue is not excised from the DNA strand. Furthermore, the presistence of ara-C residues in DNA inhibits recovery of DNA synthesis following exposure to drug. The relative DNA chain-terminating effect of ara-C provides several mechanisms of action that explain internucleotide and chain terminus positioning of ara-C residues, reinitiation of previously replicated DNA segments, and DNA strand or chromosomal breaks. The precise mechanism of action is dependent upon dose scheduling of this drug.


Asunto(s)
Citarabina/metabolismo , Replicación del ADN/efectos de los fármacos , ADN de Neoplasias/genética , Diterpenos/farmacología , Animales , Afidicolina , Supervivencia Celular/efectos de los fármacos , Citarabina/toxicidad , ADN de Neoplasias/biosíntesis , Cinética , Leucemia L1210/metabolismo , Ratones , Moldes Genéticos
20.
Leuk Res ; 8(3): 355-61, 1984.
Artículo en Inglés | MEDLINE | ID: mdl-6589455

RESUMEN

The HL-60 human leukemic promyelocytic cell line can be induced to mature into terminally differentiated cells using certain chemotherapeutic agents. We have recently demonstrated that two inhibitors of DNA synthesis, cytosine arabinoside (ara-C) and aphidicolin, can induce HL-60 differentiation with the appearance of monocytic markers. These pyrimidine antimetabolites may have affected DNA methylation patterns and resulted in altered gene expression, or the differentiated phenotype may have occurred by inhibition of DNA replication. Consequently, we have extended these studies by using the purine analog, adenine arabinoside (ara-A), which also acts as an inhibitor of DNA synthesis. The results demonstrate that ara-A also induces HL-60 non-specific esterase activity and enhances expression of myeloid cell surface antigens, MY-4 and MO-1. The induction of a differentiated phenotype by ara-A occurs after partial inhibition of DNA synthesis, a finding similar to that observed with ara-C and aphidicolin. These observations indicate that purine, as well as pyrimidine analog inhibitors of DNA polymerization can induce differentiation of HL-60 cells along a monocytic lineage. These findings may be relevant to recent clinical trials that have employed low doses of ara-C in an attempt to induce differentiation of malignant hematopoietic cells.


Asunto(s)
Citarabina/toxicidad , Leucemia Linfoide/fisiopatología , Anticuerpos Monoclonales , Antígenos de Superficie/análisis , Carboxilesterasa , Hidrolasas de Éster Carboxílico/metabolismo , Diferenciación Celular/efectos de los fármacos , División Celular/efectos de los fármacos , Línea Celular , Replicación del ADN/efectos de los fármacos , Humanos , Cinética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA