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2.
Br J Oral Maxillofac Surg ; 55(6): 575-579, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28372881

RESUMEN

To find out whether documentation for the extraction of wisdom teeth complies with National Institute of Health and Care Excellence (NICE) guidelines, we reviewed the referral letters and hospital notes of patients treated at the maxillofacial unit of two NHS Trusts (A: 314 records and B: 280) over 12 months (1 September 2012 to 31 August 2013). Compliance was assessed as unsatisfactory ("indication for extraction not mentioned", "incorrect indication", "indication unclear") or satisfactory ("correct indication implied", "correct indication explicit"). The grade of the clinician who examined the patient was also recorded. A total of 194/314 (62%) referral letters in Trust A and 126/280 (45%) in Trust B were unsatisfactory (p<0.001). Hospital notes were unsatisfactory in 168/323 (52%) and 87/297 (29%) of cases, respectively (p<0.001). In Trust A, middle grades saw 23% (75/323) of the patients, as compared with 53% (157/297) in Trust B. In both, junior staff produced the highest percentage of satisfactory documentation, but in Trust A they were also responsible for most of the unsatisfactory examples. However, senior house officers saw 60% (195/323) of the patients in Trust A, and only 28% (83/297) in Trust B. Consultants were responsible for significantly more unsatisfactory documentation (p<0.001). One referral letter (0.2%) and seven hospital records (1%) explicitly and accurately complied with the guidelines. We conclude that compliance of documentation with the current NICE guidelines is poor and inconsistent.


Asunto(s)
Documentación/normas , Adhesión a Directriz , Guías de Práctica Clínica como Asunto , Derivación y Consulta/normas , Humanos , Tercer Molar/cirugía , Medicina Estatal , Extracción Dental , Reino Unido
3.
Oncogene ; 33(7): 823-31, 2014 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-23376846

RESUMEN

Pancreatic cancer remains as one of the most deadly cancers with few treatment options at late stages and little information about how it develops through earlier stages. Activating mutation of the Kras gene has been implicated in, but is not sufficient for, tumorigenesis. In mouse models of pancreatic cancer, loss of tumor suppressor genes in conjunction with Kras mutation leads to gradual stochastic acquisition of neoplastic precursors and carcinomas, whereas many cells remain phenotypically unaltered in younger mice. Here, we demonstrate that two oncogenic events, mutation of Kras and production of the growth factor heparin-binding epidermal growth factor-like growth factor (HB-EGF), are sufficient for rapid and complete neoplastic transformation of the exocrine pancreas. We found that macrophages are the major source of HB-EGF production in pancreatic cancer tissue samples, and that macrophages are present in high density and in close association with human pancreatic cancer lesions. In a mouse model, high macrophage density was observed at the earliest stages of neoplastic transformation. The consequence of elevated HB-EGF signaling was investigated without the confounding effects of other macrophage-produced factors via transgenic overexpression of the active form of HB-EGF. In this model, HB-EGF was sufficient to promote Kras-initiated tumorigenesis, inducing rapid and complete neoplastic transformation of the entire exocrine pancreas shortly after birth. HB-EGF overexpression and Kras(G12D) together, but neither alone, increased proliferation with increased cyclinD1 and decreased Cdkn2a/2d (p16/p19(Ink4A/Arf)). These findings establish the importance of oncogenic synergy in cancer initiation and promotion, and establish a molecular link between inflammation and the earliest stages of tumor induction.


Asunto(s)
Carcinoma Ductal Pancreático/metabolismo , Péptidos y Proteínas de Señalización Intercelular/fisiología , Neoplasias Pancreáticas/metabolismo , Proteínas Proto-Oncogénicas/genética , Proteínas ras/genética , Animales , Carcinogénesis/genética , Carcinogénesis/metabolismo , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patología , Proliferación Celular , Células Cultivadas , Factor de Crecimiento Similar a EGF de Unión a Heparina , Humanos , Macrófagos/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Mutación Missense , Páncreas/patología , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patología , Fosforilación , Procesamiento Proteico-Postraduccional , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas p21(ras) , Proteínas ras/metabolismo
5.
Exp Appl Acarol ; 53(3): 215-34, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20838882

RESUMEN

Herbicide strips are used in apple orchards to promote tree growth and survival, to increase yield and to reduce the risk of rodent damage to tree bark. However, herbicide strips, particularly wider ones, may cause problems including soil erosion, reduced organic matter, leaching of nitrates into ground water and increased incidence of plant diseases and pests, including two-spotted spider mites, Tetranychus urticae Koch. In this 2 year study we monitored mite dynamics in apple trees and used sticky bands on tree trunks to determine rates of T. urticae immigration into Nova Spy apple trees in plots with wide (2 m) or narrow (0.5 m) herbicide strips. Use of wider herbicide strips promoted two risk factors that could trigger outbreaks of tetranychid mites. First, concentrations of leaf N in apple trees were higher and those of P and K were lower with the wide strips. Such changes in nutritional quality of leaves would increase the potential for more rapid population growth of T. urticae, and to a lesser extent, the European red mite, Panonychus ulmi (Koch). Second, there were higher rates of T. urticae immigration from the ground cover vegetation into the trees. In 2006, and for most of 2007, densities of T. urticae were higher with wide herbicide strips, whereas densities of P. ulmi were not enhanced. However, by late August to early September in 2007, densities of both tetranychids were lower with wide herbicide strips. This is because both risk factors were counterbalanced, and eventually negated, by the enhanced action of phytoseiid predators, mostly Typhlodromus pyri Scheuten. From July through September 2006, ratios of phytoseiids to tetranychids were always several-fold lower with wide herbicide strips but in 2007, from mid-July onwards, predator-prey ratios were usually several-fold higher with wide strips. However, this numerical response of phytoseiids to prey density can only occur where the pesticide program in orchards is not too harsh on phytoseiids. Hence the impact of width of herbicide strip is contingent on the composition and size of the phytoseiid complex and the impact of pesticides on predation.


Asunto(s)
Herbicidas , Malus , Ácaros , Tetranychidae , Migración Animal , Animales , Control de Insectos , Nueva Escocia , Hojas de la Planta , Crecimiento Demográfico , Conducta Predatoria , Factores de Riesgo , Árboles
6.
Leukemia ; 24(5): 909-13, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20376086

RESUMEN

Recent whole-genome sequencing efforts led to the identification of IDH1(R132) mutations in acute myeloid leukemia (AML) patients. We studied the prevalence and clinical implications of IDH1 genomic alterations in pediatric and adult AML. Diagnostic DNA from 531 AML patients treated on Children's Oncology Group trial COG-AAML03P1 (N=257), and Southwest Oncology Group trials SWOG-9031, SWOG-9333 and SWOG-9500 (N=274), were tested for IDH1 mutations. Codon R132 mutations were absent in the pediatric cohort, but were found in 12 of 274 adult patients (4.4%, 95% CI 2.3-7.5). IDH1(R132) mutations occurred most commonly in patients with normal karyotype, and those with FLT3/ITD and NPMc mutations. Patients with IDH1(R132) mutations trended toward higher median diagnostic white blood cell counts (59.2 x 10(9) vs 29.1 x 10(9) per liter, P=0.19) than those without mutations, but the two groups did not differ significantly in age, bone marrow blast percentage, overall survival or relapse-free survival. Eleven patients (2.1%) harbored a novel V71I sequence alteration, which was found to be a germ-line polymorphism. IDH1 mutations were not detected in pediatric AML, and are uncommon in adult AML.


Asunto(s)
Biomarcadores de Tumor/genética , Codón/genética , Isocitrato Deshidrogenasa/genética , Leucemia Mieloide Aguda/genética , Mutación/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Genotipo , Humanos , Lactante , Recién Nacido , Cariotipificación , Leucemia Mieloide Aguda/patología , Masculino , Persona de Mediana Edad , Proteínas Nucleares/genética , Nucleofosmina , Prevalencia , Pronóstico , Secuencias Repetidas en Tándem/genética , Adulto Joven , Tirosina Quinasa 3 Similar a fms/genética
7.
Exp Appl Acarol ; 43(4): 235-53, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-18008172

RESUMEN

We sampled mites in three apple orchards in Nova Scotia, Canada, that had been inoculated with pyrethroid-resistant Typhlodromus pyri and had a history of Tetranychus urticae outbreaks. The objective of this study was to monitor populations of T. urticae and phytoseiid predators on the ground and in trees and to track dispersal between the two habitats. Pesticides were the chief cause of differences in mite dynamics between orchards. In two orchards, application of favourably selective acaricides (abamectin, clofentezine) in 2002, coupled with predation by T. pyri in trees and Neoseiulus fallacis in ground cover, decreased high T. urticae counts and suppressed Panonychus ulmi. By 2003 phytoseiids kept the tetranychids at low levels. In a third orchard, application of pyrethroids (cypermethrin, lambda-cyhalothrin), plus an unfavourably selective acaricide (pyridaben) in 2003, suppressed phytoseiids, allowing exponential increases of T. urticae in the ground cover and in tree canopies. By 2004 however, increasing numbers of T. pyri and application of clofentezine strongly reduced densities of T. urticae in tree canopies despite high numbers crawling up from the ground cover. Another influence on T. urticae dynamics was the distribution of the phytoseiids, T. pyri and N. fallacis. When harsh pesticides were avoided, T. pyri were numerous in tree canopies. Conversely, only a few N. fallacis were found there, even when they were present in the ground cover and on tree trunks. Low numbers were sometimes due to pyrethroid applications or to scarcity of prey. Another factor was likely the abundance of T. pyri, which not only competes with N. fallacis, but also feeds on its larvae and nymphs. The scarcity of a specialist predator of spider mites in trees means that control of T. urticae largely depends on T. pyri, a generalist predator that is not particularly effective in regulating T. urticae.


Asunto(s)
Insecticidas , Malus/parasitología , Infestaciones por Ácaros/prevención & control , Piretrinas , Tetranychidae/crecimiento & desarrollo , Animales , Conducta Predatoria , Árboles/parasitología
8.
Oncogene ; 26(21): 3051-9, 2007 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-17130841

RESUMEN

Activating mutations in members of the RAS family of genes are among the most common genetic events in human tumorigenesis. Once thought to be functionally interchangeable, it is increasingly recognized that the classical members of this protein family (H-RAS, N-RAS and K-RAS4B) exhibit unique and shared functions that are highly context-dependent. Herein, we demonstrate that the presence of an oncogenic KRAS allele results in elevated levels of GTP-bound N-RAS (N-RAS.GTP) in two human colorectal cancer cell lines, HCT 116 and DLD-1, compared to their isogenic counterparts in which the mutant KRAS allele has been disrupted by homologous recombination. N-RAS subserves an antiapoptotic role in cells expressing wild-type K-RAS; this function is compromised, however, by the presence of mutant K-RAS, and these cells display increased sensitivity to apoptotic stimuli. We additionally identify a physical interaction between N-RAS and gelsolin, a factor that has been shown to promote survival and show that the N-RAS:gelsolin complex is modulated differently in wild-type and mutant K-RAS environments following apoptotic challenge. These findings represent the first biochemical evidence of a functional relationship between endogenous RAS proteins and identify a dynamic physical interaction between endogenous N-RAS and gelsolin that correlates with survival.


Asunto(s)
Proteínas Reguladoras de la Apoptosis/genética , Apoptosis/genética , Gelsolina/metabolismo , Genes ras/fisiología , Proteínas Proto-Oncogénicas p21(ras)/fisiología , Proteínas ras/fisiología , Animales , Proteínas Reguladoras de la Apoptosis/fisiología , Células CACO-2 , Línea Celular , Supervivencia Celular/genética , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Gelsolina/fisiología , Células HCT116 , Humanos , Ratones , Proteínas Proto-Oncogénicas p21(ras)/genética , Proteínas ras/genética
9.
Neuroscience ; 115(2): 587-602, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12421624

RESUMEN

Cardiolipin, a lipid of the mitochondrial inner membrane, is lost from many types of cells during apoptotic death. Here we show that the cardiolipin content of nerve growth factor (NGF)-deprived rat sympathetic neurons undergoing apoptotic death in cell culture decreased before extensive loss of mitochondria from the cells. By 18-24 h after NGF deprivation, many neurons did not stain with the cardiolipin-specific dye, Nonyl Acridine Orange, suggesting complete loss of cardiolipin. Gas chromatography confirmed the decline of cardiolipin content in NGF-deprived neurons. Electron microscopy and immunoblots for the mitochondrial-specific protein, heat shock protein 60 (HSP60), revealed that there was only a slight decrease in mitochondrial mass at this time. Cardiolipin loss after NGF deprivation was concurrent with increased production of mitochondrial-derived reactive oxygen species [Kirkland, R.A., Franklin, J.L., 2001. J. Neurosci. 21, 1949-1963] and increased lipid peroxidation. Compounds having antioxidant effects blocked peroxidation, loss of cardiolipin, and the decrease of mitochondrial mass in NGF-deprived neurons. These compounds also blocked an increase in the number of lysosomes and autophagosomes in NGF-deprived cells. The findings reported here show that the important mitochondrial inner membrane lipid, cardiolipin, is lost from mitochondria during neuronal apoptosis and that this loss occurs before significant loss of mitochondria from cells. They suggest that the loss of cardiolipin is mediated by free radical oxygen.


Asunto(s)
Apoptosis/fisiología , Autofagia/fisiología , Cardiolipinas/metabolismo , Mitocondrias/metabolismo , Neuronas/citología , Animales , Apoptosis/efectos de los fármacos , Células Cultivadas , Grupo Citocromo c/metabolismo , Femenino , Peroxidación de Lípido/efectos de los fármacos , Peroxidación de Lípido/fisiología , Microscopía Electrónica , Mitocondrias/efectos de los fármacos , Mitocondrias/ultraestructura , Factor de Crecimiento Nervioso/farmacología , Neuronas/metabolismo , Embarazo , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo
10.
J Neurosci ; 21(6): 1949-63, 2001 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-11245680

RESUMEN

Sympathetic neurons die by apoptosis when they are deprived of nerve growth factor (NGF). Activation of caspases by cytochrome c released from mitochondria is central to this death. In this report we present evidence that cellular redox state regulates cytochrome c redistribution in these neurons. An increase of mitochondrial-produced reactive oxygen species (ROS) occurred in rat sympathetic neurons in cell culture within 3 hr of NGF withdrawal. Caspase inhibitors blocked this ROS burst. By 6 hr after NGF deprivation, glutathione (GSH) levels had increased, neutralizing elevated hydrogen peroxide levels and returning cellular redox state to basal levels. By 12 hr after deprivation, ROS levels had again increased and remained elevated during the rest of the apoptotic process. The later ROS burst appeared to have both caspase-dependent and caspase-independent components and was coincident with the period of cytochrome c release. Inhibition of protein synthesis with cycloheximide (CHX) and treatment with the antioxidant compound, N-acetyl-l-cysteine (l-NAC), blocked both the early and late ROS bursts by increasing cellular GSH levels (Ratan et al., 1994; Tan et al., 1998). Both compounds, and a membrane-permeant form of GSH, also inhibited cytochrome c release and death. Treatment of NGF, CHX-, l-NAC-, and GSH-saved cells with hydrogen peroxide caused rapid cytochrome c release. These data suggest a role for cellular redox state in regulating cytochrome c release during apoptosis induced by NGF withdrawal.


Asunto(s)
Inhibidores de Cisteína Proteinasa/farmacología , Grupo Citocromo c/metabolismo , Neuronas/metabolismo , Inhibidores de la Síntesis de la Proteína/farmacología , Animales , Antioxidantes/farmacología , Apoptosis/fisiología , Inhibidores de Caspasas , Caspasas/efectos de los fármacos , Caspasas/metabolismo , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Transporte de Electrón/fisiología , Colorantes Fluorescentes , Glutatión/metabolismo , Peróxido de Hidrógeno/metabolismo , Concentración de Iones de Hidrógeno/efectos de los fármacos , Líquido Intracelular/efectos de los fármacos , Líquido Intracelular/metabolismo , Factor de Crecimiento Nervioso/farmacología , Neuronas/citología , Neuronas/efectos de los fármacos , Oxidación-Reducción/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Sistema Nervioso Simpático/citología , Sistema Nervioso Simpático/efectos de los fármacos , Sistema Nervioso Simpático/metabolismo
11.
J Mass Spectrom ; 36(1): 3-14, 2001 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11180641

RESUMEN

At elevated pressures in a mass spectrometer ion source reactions occur between certain ions and the neutral species present. We have studied the various secondary ions formed in methane and ethylene at elevated pressures and have determined the reactions by which they are formed and the rates of these reactions. The rates are all extremely fast. The reaction rates have been treated by classical collision theory and it has been shown that to a fair approximation the cross-sections and reaction rate constants can be predicted from a simple balance of rotational and polarization forces. [Reprinted from J. Am. Chem. Soc. 1957; 79: 2419.]

12.
Exp Cell Res ; 255(2): 327-32, 2000 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-10694448

RESUMEN

Sox9 plays a crucial role in chondrogenesis. It encodes an HMG-domain transcription factor that activates an enhancer in the gene for type II collagen (Col2a1), a principal cartilage matrix protein. We have characterized the temporal pattern of Sox9 RNA expression in micromass culture, a widely used in vitro model for the analysis of embryonic cartilage differentiation. Cultures were prepared from distal subridge mesenchyme of the stage 24/25 chick embryo wing bud, which undergoes uniform chondrogenic differentiation in vitro. The early "prechondrogenic" phase of culture was characterized by the activation of Sox9 RNA expression, which preceded detectable upregulation of Col2a1 transcription. Sox9 RNA levels peaked between 20 and 65 h of culture, a phase of progressive Col2a1 transcript accumulation, then declined in the mature cartilage of 120-h cultures. Staurosporine treatment enhanced chondrogenesis in micromass culture by inducing a rapid quantitative increase in Sox9 transcript levels. However, PMA, a phorbol ester that inhibits Col2a1 expression and chondrocyte differentiation, had an unexpectedly modest effect on Sox9 RNA accumulation.


Asunto(s)
Condrocitos/metabolismo , Proteínas del Grupo de Alta Movilidad/biosíntesis , Factores de Transcripción/biosíntesis , Animales , Cartílago/embriología , Cartílago/metabolismo , Diferenciación Celular , Embrión de Pollo , Condrocitos/citología , Embrión no Mamífero/metabolismo , Extremidades/embriología , Regulación del Desarrollo de la Expresión Génica , Mesodermo , Factor de Transcripción SOX9
13.
Curr Biol ; 9(24): 1448-57, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10607588

RESUMEN

BACKGROUND: On the basis of experiments suggesting that Notch and Delta have a role in axonal development in Drosophila neurons, we studied the ability of components of the Notch signaling pathway to modulate neurite formation in mammalian neuroblastoma cells in vitro. RESULTS: We observed that N2a neuroblastoma cells expressing an activated form of Notch, Notch1(IC), produced shorter neurites compared with controls, whereas N2a cell lines expressing a dominant-negative Notch1 or a dominant-negative Delta1 construct extended longer neurites with a greater number of primary neurites. We then compared the effects on neurites of contacting Delta1 on another cell and of overexpression of Delta1 in the neurite-extending cell itself. We found that N2a cells co-cultured with Delta1-expressing quail cells produced fewer and shorter neuritic processes. On the other hand, high levels of Delta1 expressed in the N2a cells themselves stimulated neurite extension, increased numbers of primary neurites and induced expression of Jagged1 and Notch1. CONCLUSIONS: These studies show that Notch signals can antagonize neurite outgrowth and that repressing endogenous Notch signals enhances neurite outgrowth in neuroblastoma cells. Notch signals therefore act as regulators of neuritic extension in neuroblastoma cells. The response of neuritic processes to Delta1 expressed in the neurite was opposite to that to Delta1 contacted on another cell, however. These results suggest a model in which developing neurons determine their extent of process outgrowth on the basis of the opposing influences on Notch signals of ligands contacted on another cell and ligands expressed in the same cell.


Asunto(s)
Proteínas de la Membrana/fisiología , Neuritas/ultraestructura , Receptores de Superficie Celular , Factores de Transcripción , Animales , Proteínas de Unión al Calcio , Proteínas de Drosophila , Expresión Génica , Regulación del Desarrollo de la Expresión Génica , Péptidos y Proteínas de Señalización Intercelular , Péptidos y Proteínas de Señalización Intracelular , Proteína Jagged-1 , Proteínas de la Membrana/genética , Ratones , Modelos Neurológicos , Neuritas/fisiología , Neuroblastoma/genética , Neuroblastoma/ultraestructura , Proteínas/genética , Proteínas/fisiología , Receptor Notch1 , Proteínas Serrate-Jagged , Transducción de Señal , Células Tumorales Cultivadas
14.
Hum Pathol ; 30(7): 849-55, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10414505

RESUMEN

Nasal NK/T-cell lymphoma is a unique form of lymphoma highly associated with Epstein-Barr virus (EBV). These lymphomas are rare in Western populations and much more prevalent in some Asian and Latin American countries. Although there are several sizable studies from Asian countries, the same is not true from South America. The aim of this study was to analyze a series of 32 cases of nasal T-cell lymphoma from Peru and to further extend the characterization of this disease. Immunohistochemistry was performed on paraffin sections using the following antibodies: CD20 (L26), CD45RO, CD3, Ki67, CD57, CD56, TIA-1, bcl-2, and p53. The presence of EBV was investigated with immunohistochemical analysis for latent membrane protein (LMP)-1 and in situ hybridization using an antisense riboprobe to EBER 1. The 32 patients included 18 men and 14 women (M:F ratio, 1.2:1), with a median age of 43 years (11 to 72). Three categories were identified: (1) Nasal NK/T cell lymphomas (28 cases): The morphology ranged from small or medium-sized cells to large transformed cells. Necrosis was present in 86% of the cases, and angioinvasion was seen in 36% of the cases. All cases were positive for CD45RO, CD3, and for TIA-1. CD56 was positive in 21 of 27 cases (78%), and CD57 was negative in all cases. EBER 1 positivity was identified in most of the tumor cells in 27 of 28 cases (96%), including the six cases in which CD56 was negative. Overexpression of p53 was detected in 24 cases (86%). (2) Blastic NK cell lymphoma (1 case): The neoplastic cells resembled those of lymphoblastic lymphoma. CD56 and CD45RO were positive; TIA-1, TdT, and EBER-1 were negative. (3) Peripheral T-cell lymphoma (PTCL) unspecified (3 cases): CD56, TIA-1, and EBER-1 were negative. Nasal lymphomas from Peru with a T cell phenotype are predominantly EBV-associated NK/T cell lymphomas, similar to those described in Asian countries. The expression of CD56, TIA-1, and EBER-1, in combination, are very useful markers for the diagnosis of nasal NK/T cell lymphoma in paraffin-embedded tissue. The differential diagnosis of T-cell lymphomas in the nasal region should include rare cases of PTCL unspecified and the blastic variant of NK cell lymphoma. P53 is overexpressed in 86% of the cases. The significance of this finding with regard to clinical behavior and prognosis remains to be determined.


Asunto(s)
Células Asesinas Naturales/patología , Linfoma de Células T/patología , Neoplasias Nasales/patología , Adolescente , Adulto , Niño , Femenino , Humanos , Inmunohistoquímica , Inmunofenotipificación , Hibridación in Situ , Células Asesinas Naturales/metabolismo , Linfoma de Células T/epidemiología , Linfoma de Células T/metabolismo , Linfoma de Células T Periférico/epidemiología , Linfoma de Células T Periférico/metabolismo , Linfoma de Células T Periférico/patología , Masculino , Persona de Mediana Edad , Neoplasias Nasales/epidemiología , Neoplasias Nasales/metabolismo , Perú , Prevalencia , Proteína p53 Supresora de Tumor/metabolismo
15.
J Cell Biol ; 142(5): 1313-24, 1998 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-9732291

RESUMEN

We demonstrate that NGF couples the rate of degradation of long-lived proteins in sympathetic neurons to the rate of protein synthesis. Inhibiting protein synthesis rate by a specific percentage caused an almost equivalent percentage reduction in the degradation rate of long-lived proteins, indicating nearly 1:1 coupling between the two processes. The rate of degradation of short-lived proteins was unaffected by suppressing protein synthesis. Included in the pool of proteins that had increased half-lives when protein synthesis was inhibited were actin and tubulin. Both of these proteins, which had half-lives of several days, exhibited no degradation over a 3-d period when protein synthesis was completely suppressed. The half-lives of seven other long-lived proteins were quantified and found to increase by 84-225% when protein synthesis was completely blocked. Degradation-synthesis coupling protected cells from protein loss during periods of decreased synthesis. The rate of protein synthesis greatly decreased and coupling between degradation and synthesis was lost after removal of NGF. Uncoupling resulted in net loss of cellular protein and somatic atrophy. We propose that coupling the rate of protein degradation to that of protein synthesis is a fundamental mechanism by which neurotrophic factors maintain homeostatic control of neuronal size and perhaps growth.


Asunto(s)
Tamaño de la Célula/fisiología , Homeostasis/fisiología , Factores de Crecimiento Nervioso/fisiología , Proteínas del Tejido Nervioso/metabolismo , Proteínas del Tejido Nervioso/fisiología , Actinas/metabolismo , Animales , Anisomicina/farmacología , Apoptosis/fisiología , División Celular/fisiología , Células Cultivadas , Cicloheximida/farmacología , Dactinomicina/farmacología , Embrión de Mamíferos/fisiología , Ganglios/embriología , Cinética , Microscopía de Contraste de Fase , Neuronas/fisiología , Biosíntesis de Proteínas/efectos de los fármacos , Inhibidores de la Síntesis de la Proteína/farmacología , Ratas , Ratas Sprague-Dawley , Transcripción Genética/genética , Tubulina (Proteína)/metabolismo
16.
J Mol Biol ; 277(3): 541-57, 1998 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-9533879

RESUMEN

Bacteriophage terminases are oligomeric multifunctional proteins that bind to vegetative DNA, cut it and, together with portal proteins, translocate the DNA into preformed heads. Most terminases are encoded by two partially overlapping genes. In phage T4 they are genes 16 and 17. We have shown before that the larger of these, gene 17, can yield, in addition to a full-length 70 kDa product, several shorter peptides. At least two of these, gene product (gp) 17' and gp17", are initiated in the same reading frame as the 70 kDa gp17 from internal ribosome binding sites. Most of the shorter gp17 s contain predicted ATPase motifs, but only the largest (70 kDa) peptide has a predicted single-stranded DNA binding domain. Here we describe the DNA binding and cutting properties of the purified 70 kDa protein, expressed from two different clones containing gene 17 but no other T4 gene. Epitope-specific antibodies, which recognize several different gene 17 products in extracts of induced clones or of T4-infected cells, precipitate the purified 70 kDa gp17. When Mg2+ is chelated by EDTA this 70 kDa protein binds to single-stranded DNA, preferentially to junctions of single- and double-stranded DNA segments. It does not bind to blunt-ended double-stranded DNA. When Mg2+ is present the purified 70 kDa gp17 digests single-stranded segments preferentially up to junctions with double-stranded DNA. A 70 kDa gp17 from a P379L temperature sensitive (ts) mutant, which has lost the nuclease and ATPase activities, retains the single-stranded DNA binding activity. Taken together with earlier findings these results support a model for packaging of T4 DNA from single-stranded regions in recombinational or replicative intermediates, which occur at nearly random positions of the genome. This mechanism may be an alternative to site-specific initiation of packaging proposed by other investigators.


Asunto(s)
Bacteriófago T4/enzimología , ADN de Cadena Simple/metabolismo , Endodesoxirribonucleasas/metabolismo , Proteínas Virales/metabolismo , Adenosina Trifosfatasas/metabolismo , Secuencia de Aminoácidos , Secuencia de Bases , Desoxirribonucleasa I/metabolismo , Endodesoxirribonucleasas/genética , Datos de Secuencia Molecular , Péptidos/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Sefarosa , Especificidad por Sustrato , Proteínas Virales/genética
17.
Gene ; 177(1-2): 179-89, 1996 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-8921865

RESUMEN

The products of the bacteriophage T4 terminase genes 16 and 17 are known to mediate cutting and packaging of concatemeric vegetative DNA. We show here that the larger of these genes, 17, yields multiple protein species. The complex expression of the T4 terminase genes includes overlapping transcripts, probably initiated from multiple promoters, RNA processing at certain preferred sites and translation initiation from multiple ribosome binding sites (RBS). Translation initiation from these RBS may be modulated by inverted repeat (IR) sequences whose folding can be predicted to differ in different RNA species. In T4 infected bacteria, genes 16 and 17 are probably co-transcribed from several near-consensus late promoters upstream from gene 16, and processed at multiple sites. Additional 5' ends of late transcripts are located downstream from a near-consensus late promoter inside gene 17 and further downstream, unrelated to any known promoter consensus sequence. The gene 17 transcripts that are initiated or cleaved internally contain RBS for shorter open reading frames (ORFs) in the same frame as full-length gene product (gp) 17 of 70 kDa. The truncated proteins, a 59-kDa gp17' and a 45-kDa gp17", are synthesized from cloned gene 17 segments in which the first gene 17 RBS is deleted. Expression of gene 17 is different in BL21(DE3) or W3110[pACT7] host bacteria. The gp17' and gp17" proteins are predicted to contain one or more of the ATPase motifs that are common among large subunits of other phage terminases. They lack a predicted single stranded (ss) DNA binding motif that is unique the large terminase proteins in T4 gp17, and that has been implicated in recognizing ssDNA regions in replicating and recombining T4DNA destined to be packaged. We hypothesize that a truncated gene 17' is an evolutionary precursor of the full-size T4 gene 17. Its function may have been maintained to allow processive packaging from double stranded (ds) DNA ends.


Asunto(s)
Bacteriófago T4/enzimología , Endodesoxirribonucleasas/genética , Bacteriófago T4/genética , Secuencia de Bases , Sitios de Unión , ADN Viral/química , Electroforesis en Gel de Poliacrilamida , Endodesoxirribonucleasas/metabolismo , Escherichia coli/virología , Regulación Viral de la Expresión Génica , Genes Virales , Datos de Secuencia Molecular , Conformación de Ácido Nucleico , ARN Viral/química , ARN Viral/genética , ARN Viral/metabolismo , Mapeo Restrictivo , Ribosomas/metabolismo , Transcripción Genética , Proteínas Virales/genética , Proteínas Virales/metabolismo
18.
Dis Colon Rectum ; 39(2): 196-9, 1996 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8620787

RESUMEN

PURPOSE: Our goal was to evaluate use of topical (4 percent) formalin in management of radiation-induced hemorrhagic proctitis, refractory to other methods of treatment. Specifically, we wished to determine its safety, ability to stop bleeding, and complications associated with therapy. METHODS: Sixteen patients with radiation-induced hemorrhagic proctitis were treated with topical (4 percent) formalin. All had been previously treated with conservative regimens such as cautery, topical steroids, or laser, but these had failed. Five-hundred milliliters (ml) of a 4 percent formalin solution was instilled into the rectum in 50-ml aliquots. Each aliquot was kept in contact with rectal mucosa for approximately 30 seconds. Treatments were performed under local anesthesia in nine patients, sedation only in four, spinal in two, and general in one patient. RESULTS: In 12 patients, bleeding stopped after a single formalin instillation; in 3, bleeding was considerably reduced but continued sporadically. One patient required three treatments before bleeding stopped. Four patients developed postoperative anal pain, of which one also had significant tenesmus and reduced capacity. Of these four patients, only two had significant anal pain and fissures that lasted longer than one month. CONCLUSIONS: Topical (4 percent) formalin is safe and effective in treatment of radiation-induced hemorrhagic proctitis. A single treatment will stop bleeding in 75 percent of patients.


Asunto(s)
Formaldehído/uso terapéutico , Hemorragia Gastrointestinal/etiología , Proctitis/tratamiento farmacológico , Traumatismos por Radiación/tratamiento farmacológico , Administración Rectal , Anciano , Anciano de 80 o más Años , Femenino , Formaldehído/administración & dosificación , Formaldehído/efectos adversos , Humanos , Masculino , Persona de Mediana Edad , Proctitis/complicaciones , Proctitis/etiología , Traumatismos por Radiación/complicaciones , Resultado del Tratamiento
20.
Gynecol Oncol ; 58(1): 106-9, 1995 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7789874

RESUMEN

Long-term survival in epithelial ovarian cancer remains problematic despite multimodality therapy. A fundamental difficulty is the development of tumor resistance to platinum compounds. Analogs have been developed that demonstrate activity in platinum-resistant cell lines both in vitro and in vivo. Lobaplatin (D-19466), a third-generation compound, demonstrates significant activity in carboplatin and cisplatin-resistant cell lines. Lobaplatin was given to 17 assessable patients with platinum-refractory ovarian cancer. The drug was initially administered at a dose of 50 mg/m2 but was later reduced to 40 mg/m2 because of excessive thrombocytopenia. Nine patients required red cell transfusions during therapy. Cycles were repeated every 21-35 days (median cycle length 28 days). No objective responses were observed. Lobaplatin has no activity in platinum-resistant epithelial ovarian cancer.


Asunto(s)
Antineoplásicos/uso terapéutico , Ciclobutanos/uso terapéutico , Compuestos Organoplatinos/uso terapéutico , Neoplasias Ováricas/tratamiento farmacológico , Adulto , Anciano , Resistencia a Medicamentos , Femenino , Humanos , Persona de Mediana Edad , Platino (Metal)/uso terapéutico
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