Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Plant Physiol ; 177(2): 513-521, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29724771

RESUMEN

Commelinid monocotyledons are a monophyletic clade differentiated from other monocotyledons by the presence of cell wall-bound ferulate and p-coumarate. The Poaceae, or grass family, is a member of this group, and most of the p-coumarate in the cell walls of this family acylates lignin. Here, we isolated and examined lignified cell wall preparations from 10 species of commelinid monocotyledons from nine families other than Poaceae, including species from all four commelinid monocotyledon orders (Poales, Zingiberales, Commelinales, and Arecales). We showed that, as in the Poaceae, lignin-linked p-coumarate occurs exclusively on the hydroxyl group on the γ-carbon of lignin unit side chains, mostly on syringyl units. Although the mechanism of acylation has not been studied directly in these species, it is likely to be similar to that in the Poaceae and involve BAHD acyl-coenzyme A:monolignol transferases.


Asunto(s)
Pared Celular/química , Lignina/metabolismo , Magnoliopsida/química , Propionatos/metabolismo , Acilación , Commelinaceae/química , Commelinaceae/citología , Cotiledón/citología , Ácidos Cumáricos , Hidrólisis , Lignina/química , Espectroscopía de Resonancia Magnética , Magnoliopsida/citología , Parabenos/química , Parabenos/metabolismo , Células Vegetales/química , Células Vegetales/metabolismo , Propionatos/química , Zingiberales/química , Zingiberales/citología
2.
Plant Physiol ; 175(3): 1058-1067, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28894022

RESUMEN

The cell walls of leaf base tissues of the Canary Island date palm (Phoenix canariensis) contain lignins with the most complex compositions described to date. The lignin composition varies by tissue region and is derived from traditional monolignols (ML) along with an unprecedented range of ML conjugates: ML-acetate, ML-benzoate, ML-p-hydroxybenzoate, ML-vanillate, ML-p-coumarate, and ML-ferulate. The specific functions of such complex lignin compositions are unknown. However, the distribution of the ML conjugates varies depending on the tissue region, indicating that they may play specific roles in the cell walls of these tissues and/or in the plant's defense system.


Asunto(s)
Lignina/metabolismo , Phoeniceae/metabolismo , Hojas de la Planta/metabolismo , Pared Celular/metabolismo , Cromatografía en Gel , Lignina/aislamiento & purificación , Espectroscopía de Resonancia Magnética , España
3.
Sci Adv ; 2(10): e1600393, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27757415

RESUMEN

Angiosperms represent most of the terrestrial plants and are the primary research focus for the conversion of biomass to liquid fuels and coproducts. Lignin limits our access to fibers and represents a large fraction of the chemical energy stored in plant cell walls. Recently, the incorporation of monolignol ferulates into lignin polymers was accomplished via the engineering of an exotic transferase into commercially relevant poplar. We report that various angiosperm species might have convergently evolved to natively produce lignins that incorporate monolignol ferulate conjugates. We show that this activity may be accomplished by a BAHD feruloyl-coenzyme A monolignol transferase, OsFMT1 (AT5), in rice and its orthologs in other monocots.

4.
Histopathology ; 62(4): 563-77, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23432624

RESUMEN

AIMS: A recent study examining the specificity of human epidermal growth factor receptor (HER) 2 pharmacodiagnostic antibodies demonstrated that CB11 and 4B5 stain both HER2-transfected and HER4-transfected cell lines. However, there has been no evidence showing that 4B5 has affinity for HER4 in clinically obtained tissues, and, if so, whether this has any impact on the assessment of HER2. We therefore sought to determine the expression of membrane-bound HER4 in clinical breast carcinomas, and evaluate its impact on the clinical utility of 4B5 in determining HER2 status. METHODS AND RESULTS: Breast carcinomas were assessed by immunohistochemistry (IHC) for membrane-bound HER4 using anti-HER4 clone E200. HER2 expression in these cases was then assessed using anti-HER2 clone 4B5, and a reference clone, SP3. In all 117 membrane HER4-positive cases (out of 241), 4B5 scored equal to or less than the reference anti-HER2 clone SP3. Eighteen cases were positive for membrane-bound HER4 by E200 and negative by 4B5, including a membrane HER4 level 3+ case. CONCLUSIONS: No cross-reactivity of 4B5 with membrane-bound HER4 was identified in the clinical IHC analysis of formalin-fixed paraffin-embedded breast carcinoma cases as evidenced by the HER4 antibody clone E200.


Asunto(s)
Adenocarcinoma/metabolismo , Neoplasias de la Mama/metabolismo , Receptores ErbB/metabolismo , Adenocarcinoma/patología , Anticuerpos Monoclonales/inmunología , Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/patología , Membrana Celular/metabolismo , Receptores ErbB/inmunología , Femenino , Humanos , Receptor ErbB-4
5.
Int J Gynecol Pathol ; 31(6): 588-95, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23018222

RESUMEN

The purpose of this study was to develop and analytically and functionally validate a new human papillomavirus (HPV) in-situ hybridization (ISH) assay and to determine whether the use of this assay combined with hemotoxylin and eosin (H&E) staining could potentially improve the diagnostic accuracy of interpreting cervical intraepithelial neoplasia (CIN) in human cervical tissue specimens. An automated HPV ISH assay was developed using probes that targeted the broad spectrum of HPV genotypes most commonly associated with CIN. In an exploratory study, tissue sections (n=118) were stained with H&E alone and H&E with HPV ISH and evaluated by 6 general surgical pathologists. Results were compared with diagnoses established by expert pathologists on H&E alone. The change in specificity (diagnosis of no-CIN) and sensitivity (diagnosis of CIN) using H&E plus HPV versus H&E alone was determined. The HPV ISH assay detected 21 HPV genotypes and demonstrated no cross-reactivity to Epstein-Barr virus, cytomegalovirus, herpes simplex virus (HSV)-1, HSV-2, or human placental DNA. The assay detected HPV in a range of 1 to 600 copies on CaSki, HeLa, and SiHa xenografts. Use of this assay with H&E staining improved the average diagnostic specificity of the surgical pathologists from 68.5% to 89.9% (P<0.001), with fewer false-positive CIN 1 results (122 vs. 39). The diagnostic sensitivity was similar for assessments made with H&E alone and those made with HPV plus H&E (93.1% vs. 93.6%). In conclusion, a new automated broad-spectrum HPV ISH assay combined with H&E-stained slides contributed to better ascertainment of CIN than H&E staining alone.


Asunto(s)
Hibridación in Situ/métodos , Papillomaviridae/aislamiento & purificación , Displasia del Cuello del Útero/diagnóstico , Neoplasias del Cuello Uterino/diagnóstico , Femenino , Humanos , Papillomaviridae/genética , Neoplasias del Cuello Uterino/virología , Displasia del Cuello del Útero/virología
6.
Am J Surg Pathol ; 34(6): 767-76, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20421783

RESUMEN

The importance of HER2 status in breast cancer management has focused attention on the ability of clinical assays to correctly assign HER2 amplification status. There is no consensus as to the best method for assessing HER2 status. Disadvantages of fluorescence in situ hybridization (FISH) testing include longer time required for staining and scoring slides, requirements for specialized training and fluorescence microscopy, and loss of the signal due to quenching of the fluorescent dye. Silver-enhanced in situ hybridization (SISH) is a rapid fully automated assay providing permanently stained slides that are interpreted by conventional bright field microscopy which enables pathologists to evaluate slides within the context of tissue morphology. This study evaluates the concordance between SISH and FISH assays in determining the status of HER2 gene amplification in a cohort of 298 primary invasive breast carcinomas. Furthermore, we assessed in detail the variables contributing to interobserver interpretive reproducibility of HER2 SISH among 10 pathologists. HER2 was quantified using the ratio of HER2 to CHR17 signals using the conventional historical interpretation scale and also by the American Society of Clinical Oncology/College of American Pathologists reporting scheme. For SISH status determined by consensus among 10 pathologists, overall concordance between SISH and FISH was identified in 288 of 298 cases (96.6%) using the conventional Food and Drug Administration approved criteria. Overall agreement was observed in 282 of 285 cases (98.9%) using the American Society of Clinical Oncology/College of American Pathologists result reporting scheme (with equivocal cases removed). In conclusion, SISH represents a novel approach for the determination of HER2 status in breast cancer. The overall concordance between SISH and FISH is excellent, and the interpretation of SISH results by pathologists is most reproducible using the HER2/CHR17 ratio.


Asunto(s)
Neoplasias de la Mama/genética , Genes erbB-2 , Hibridación in Situ/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , Compuestos de Plata , Femenino , Humanos , Hibridación Fluorescente in Situ , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados
8.
J Med Entomol ; 44(1): 102-10, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17294927

RESUMEN

Flock House Virus (family Nodaviridae, genus Alphanodavirus, FHV) was originally isolated from grass grubs Costelytra zealandica (White) (Coleoptera: Scarabaeidae) in New Zealand and belongs to a family of divided genome, plus-sense RNA insect viruses. FHV replicates in insects, a nematode, plants, and yeast. We previously reported replication of FHV in four genera of mosquitoes and expression of green fluorescent protein in Aedes aegypti (L.) produced by an FHV-based vector. We report here that FHV multiplies vigorously in vivo in the malaria vectors Anopheles gambiae Giles and An. stephensi Liston and in vitro in a cell line derived from An. gambiae. In addition, FHV multiplies extensively in two other medically important insects, the tsetse fly, Glossina morsitans morsitans Westwood, and the reduviid bug Rhodnius prolixus Stal, extending its host range to four orders of insects (Coleoptera, Lepidoptera, Diptera, and Hemiptera). The virus disseminates in all the major tissues of the insects studied. Anopheles and Glossina show mortality when FHV is injected at a dose above 10(4) plaque-forming units (pfu) or the virus accumulates to titer above 10(8) pfu. A lower dose (10(3) pfu) promotes more extensive virus multiplication and reduces mortality to < 10%. No adverse effects are observed in Ae. aegypti, Culex pipiens pipiens L., and Armigeres subalbatus (Coquillett), when injected with a dose of up to 10(7) pfu. Mosquitoes orally fed with FHV exhibited slower virus growth rate with lower mortality. Our results indicate that FHV has uniquely broad insect host range and that the virus can be used to study virus host interactions in a variety of medically important insects.


Asunto(s)
Insectos Vectores/virología , Insectos/virología , Nodaviridae/crecimiento & desarrollo , Replicación Viral/fisiología , Animales , Línea Celular , Especificidad de la Especie , Análisis de Supervivencia , Factores de Tiempo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...