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1.
Lett Appl Microbiol ; 71(4): 413-419, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32623751

RESUMEN

As a result of electron microscopic studies of morphogenesis in yeast Candida guilliermondii NP-4, the formation of new structures of volutin acidocalcisomes has been established within the cell cytoplasm. Under influence of X-irradiation, the changes in morphometric and electron-dense properties of yeast cells were identified: in yeast cytoplasm, the electron-dense volutin granules were increased up to 400 nm in size. After 24-h post-irradiation incubation of yeasts, the large volutin pellets are fragmented into smaller number particles in size up to 25-150 nm. The ATPase activity in yeast mitochondria was changed under X-irradiation. In latent phase of growth, ATPase activity was decreased 1·35-fold in comparison with non-irradiated yeasts. In logarithmic phase of growth, ATPase activity was three times higher than in latent phase, and in stationary phase of growth it has a value similar to the latent phase. Probably, the cells receive the necessary energy from alternative energy sources, such as volutin. Electron microscopy of volutin granule changes might serve as convenient method for evaluation of damages and repair processes in cells under influence of different environmental stress-factors.


Asunto(s)
Adenosina Trifosfatasas/metabolismo , Candida/efectos de la radiación , Candida/ultraestructura , Proteínas Fúngicas/metabolismo , Orgánulos/enzimología , Adenosina Trifosfatasas/genética , Adenosina Trifosfatasas/ultraestructura , Adenosina Trifosfato/metabolismo , Candida/enzimología , Candida/genética , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Orgánulos/genética , Orgánulos/efectos de la radiación , Orgánulos/ultraestructura , Rayos X
2.
J Neuroinflammation ; 13(1): 116, 2016 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-27220286

RESUMEN

BACKGROUND: Organelle remodeling processes are evolutionarily conserved and involved in cell functions during development, aging, and cell death. Some endogenous and exogenous molecules can modulate these processes. Docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid, has mainly been considered as a modulator of plasma membrane fluidity in brain development and aging, while DHA's role in organelle remodeling in specific neural cell types at the ultrastructural level remains largely unexplored. DHA is notably incorporated into dynamic organelles named lipid bodies (LBs). We hypothesized that DHA could attenuate the inflammatory response in lipopolysaccharide (LPS)-activated microglia by remodeling LBs and altering their functional interplay with mitochondria and other associated organelles. RESULTS: We used electron microscopy to analyze at high spatial resolution organelle changes in N9 microglial cells exposed to the proinflammogen LPS, with or without DHA supplementation. Our results revealed that DHA reverses several effects of LPS in organelles. In particular, a large number of very small and grouped LBs was exclusively found in microglial cells exposed to DHA. In contrast, LBs in LPS-stimulated cells in the absence of DHA were sparse and large. LBs formed in the presence of DHA were generally electron-dense, suggesting DHA incorporation into these organelles. The accumulation of LBs in microglial cells from mouse and human was confirmed in situ. In addition, DHA induced numerous contacts between LBs and mitochondria and reversed the frequent disruption of mitochondrial integrity observed upon LPS stimulation. Dilation of the endoplasmic reticulum lumen was also infrequent following DHA treatment, suggesting that DHA reduces oxidative stress and protein misfolding. Lipidomic analysis in N9 microglial cells treated with DHA revealed an increase in phosphatidylserine, indicating the role of this phospholipid in normalization and maintenance of physiological membrane functions. This finding was supported by a marked reduction of microglial filopodia and endosome number and significant reduction of LPS-induced phagocytosis. CONCLUSIONS: DHA attenuates the inflammatory response in LPS-stimulated microglial cells by remodeling LBs and altering their interplay with mitochondria and other associated organelles. Our findings point towards a mechanism by which omega-3 DHA participates in organelle reorganization and contributes to the maintenance of neural cell homeostasis.


Asunto(s)
Ácidos Docosahexaenoicos/farmacología , Gotas Lipídicas/efectos de los fármacos , Microglía/efectos de los fármacos , Animales , Línea Celular Transformada , Citocinas/metabolismo , Citocinas/ultraestructura , Relación Dosis-Respuesta a Droga , Ácidos Grasos/metabolismo , Gotas Lipídicas/ultraestructura , Lipopolisacáridos/farmacología , Ratones , Microglía/ultraestructura , Microscopía Electrónica de Transmisión , Orgánulos/efectos de los fármacos , Orgánulos/ultraestructura , Fagocitosis/efectos de los fármacos , Factores de Tiempo , Triglicéridos/metabolismo
3.
Plant Physiol ; 169(3): 1946-60, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26358416

RESUMEN

Pollen tube growth is an essential aspect of plant reproduction because it is the mechanism through which nonmotile sperm cells are delivered to ovules, thus allowing fertilization to occur. A pollen tube is a single cell that only grows at the tip, and this tip growth has been shown to depend on actin filaments. It is generally assumed that myosin-driven movements along these actin filaments are required to sustain the high growth rates of pollen tubes. We tested this conjecture by examining seed set, pollen fitness, and pollen tube growth for knockout mutants of five of the six myosin XI genes expressed in pollen of Arabidopsis (Arabidopsis thaliana). Single mutants had little or no reduction in overall fertility, whereas double mutants of highly similar pollen myosins had greater defects in pollen tube growth. In particular, myo11c1 myo11c2 pollen tubes grew more slowly than wild-type pollen tubes, which resulted in reduced fitness compared with the wild type and a drastic reduction in seed set. Golgi stack and peroxisome movements were also significantly reduced, and actin filaments were less organized in myo11c1 myo11c2 pollen tubes. Interestingly, the movement of yellow fluorescent protein-RabA4d-labeled vesicles and their accumulation at pollen tube tips were not affected in the myo11c1 myo11c2 double mutant, demonstrating functional specialization among myosin isoforms. We conclude that class XI myosins are required for organelle motility, actin organization, and optimal growth of pollen tubes.


Asunto(s)
Citoesqueleto de Actina/metabolismo , Arabidopsis/fisiología , Miosinas/metabolismo , Orgánulos/metabolismo , Citoesqueleto de Actina/genética , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/ultraestructura , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Genes Reporteros , Mutación , Miosinas/genética , Orgánulos/ultraestructura , Polen/genética , Polen/crecimiento & desarrollo , Polen/fisiología , Polen/ultraestructura , Tubo Polínico/genética , Tubo Polínico/crecimiento & desarrollo , Tubo Polínico/fisiología , Tubo Polínico/ultraestructura , Polinización , Isoformas de Proteínas , Semillas/genética , Semillas/crecimiento & desarrollo , Semillas/fisiología , Semillas/ultraestructura
4.
J Synchrotron Radiat ; 22(4): 1091-5, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26134816

RESUMEN

For the first time, the three-dimensional (3D) ultrastructure of an intact rice pollen cell has been obtained using a full-field transmission hard X-ray microscope operated in Zernike phase contrast mode. After reconstruction and segmentation from a series of projection images, complete 3D structural information of a 35 µm rice pollen grain is presented at a resolution of ∼100 nm. The reconstruction allows a clear differentiation of various subcellular structures within the rice pollen grain, including aperture, lipid body, mitochondrion, nucleus and vacuole. Furthermore, quantitative information was obtained about the distribution of cytoplasmic organelles and the volume percentage of each kind of organelle. These results demonstrate that transmission X-ray microscopy can be quite powerful for non-destructive investigation of 3D structures of whole eukaryotic cells.


Asunto(s)
Imagenología Tridimensional , Microscopía/métodos , Oryza/ultraestructura , Polen/ultraestructura , Orgánulos/ultraestructura
5.
Acta Trop ; 148: 170-8, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25956673

RESUMEN

The antiprotozoal activity of some indazole-derived amines (2, 3, 5-8) as well as that of some simple structurally related 3-alkoxy-1-alkyl-5-nitroindazoles (1, 4) against promastigote and amastigote forms of Leishmania infantum and Leishmania braziliensis is reported. In some cases, these compounds showed in vitro activities against the different morphological forms of Leishmania similar to or higher than those of the reference drug glucantime; this fact, along with low unspecific cytotoxicities against macrophages shown by some of them, led to good selectivity indexes (SI). The high efficiency of some 5-nitroindazoles against the mentioned protozoa was confirmed by further in vitro studies on infection rates. Complementary analyses by (1)H NMR of the changes on the metabolites excreted by parasites after treatment with the more active indazole derivatives in many cases showed the decreased excretion of succinate and increased levels of acetate, lactate and alanine, as well as, in some cases, the appearance of glycine and pyruvate as new metabolites. Damage caused by indazoles at the glycosomal or mitochondrial level are consistent with these metabolic changes as well as with the huge ultrastructural alterations observed by transmission electron microscopy (TEM), especially affecting the mitochondria and other cytoplasmic organelles.


Asunto(s)
Antiprotozoarios/farmacología , Indazoles/farmacología , Leishmania braziliensis/efectos de los fármacos , Leishmania infantum/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Acetatos/metabolismo , Alanina/metabolismo , Animales , Antiprotozoarios/química , Glicina/metabolismo , Técnicas In Vitro , Indazoles/química , Ácido Láctico/metabolismo , Leishmania braziliensis/metabolismo , Leishmania braziliensis/ultraestructura , Leishmania infantum/metabolismo , Leishmania infantum/ultraestructura , Leishmaniasis Visceral , Macrófagos/efectos de los fármacos , Espectroscopía de Resonancia Magnética , Ratones , Microscopía Electrónica de Transmisión , Mitocondrias/ultraestructura , Orgánulos/efectos de los fármacos , Orgánulos/ultraestructura , Ácido Pirúvico/metabolismo , Ácido Succínico/metabolismo
6.
Micron ; 70: 7-20, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25541480

RESUMEN

Tobraviruses, like other (+) stranded RNA viruses of plants, replicate their genome in cytoplasm and use such usual membranous structures like endoplasmic reticulum. Based on the ultrastructural examination of Tobacco rattle virus (TRV)-infected potato and tobacco leaf tissues, in this work we provide evidence of the participation of not only the membranous and vesicular ER structures but also other cell organelles during the viral infection cycle. Non-capsidated TRV PSG particles (potato isolate from the Netherlands) (long and short forms) were observed inside the nucleus while the presence of TRV capsid protein (CP) was detected in the nucleus caryolymph and within the nucleolus area. Both capsidated and non-capsidated viral particles were localized inside the strongly disorganized chloroplasts and mitochondria. The electron-dense TRV particles were connected with vesicular structures of mitochondria as well as with chloroplasts in both potato and tobacco tissues. At 15-30 days after infection, vesicles filled with TRV short particles were visible in mitochondria revealing the expanded cristae structures. Immunodetection analysis revealed the TRV PSG CP epitope inside chloroplast with disorganized thylakoids structure as well as in mitochondria of different tobacco and potato tissues. The ultrastructural analysis demonstrated high dynamics of the main cell organelles during the TRV PSG-Solanaceous plants interactions. Moreover, our results suggest a relationship between organelle changes and different stages of virus infection cycle and/or particle formation.


Asunto(s)
Retículo Endoplásmico/ultraestructura , Orgánulos/ultraestructura , Orgánulos/virología , Enfermedades de las Plantas/virología , Virus de Plantas/fisiología , Virus ARN/fisiología , Proteínas de la Cápside/aislamiento & purificación , Núcleo Celular/ultraestructura , Núcleo Celular/virología , Cloroplastos/ultraestructura , Cloroplastos/virología , Retículo Endoplásmico/virología , Células del Mesófilo/ultraestructura , Células del Mesófilo/virología , Microscopía Electrónica de Transmisión , Mitocondrias/ultraestructura , Mitocondrias/virología , Floema/ultraestructura , Floema/virología , Hojas de la Planta/virología , Virus de Plantas/ultraestructura , Virus ARN/ultraestructura , Solanum tuberosum/virología , Nicotiana/virología
7.
BMC Microbiol ; 14: 152, 2014 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-24913205

RESUMEN

BACKGROUND: Leishmania amazonensis infection results in diverse clinical manifestations: cutaneous, mucocutaneous or visceral leishmaniasis. The arsenal of drugs available for treating Leishmania infections is limited. Therefore, new, effective, and less toxic leishmaniasis treatments are still needed. We verified cell death in amastigote forms of Leishmania amazonensis induced by the sesquiterpene lactone parthenolide. RESULTS: The tested compound was able to concentration-dependently affect axenic and intracellular amastigotes, with IC50 values of 1.3 µM and 2.9 µM, respectively after 72 h incubation. No genotoxic effects were observed in a micronucleus test in mice. Parthenolide induced morphological and ultrastructural changes in axenic amastigotes, including a loss of membrane integrity, swelling of the mitochondrion, cytoplasmic vacuoles, and intense exocytic activity in the region of the flagellar pocket. These results led us to investigate the occurrence of autophagic vacuoles with monodansylcadaverine and the integrity of the plasma membrane and mitochondrial membrane potential using flow cytometry. In all of the tests, parthenolide had positive results. CONCLUSIONS: Our results indicate that the antileishmanial action of parthenolide is associated with autophagic vacuole appearance, a reduction of fluidity, a loss of membrane integrity, and mitochondrial dysfunction. Considering the limited repertoire of existing antileishmanial compounds, the products derived from medicinal plants has been one the greatest advances to help develop new chemotherapeutic approaches.


Asunto(s)
Antiprotozoarios/farmacología , Muerte Celular , Leishmania mexicana/efectos de los fármacos , Sesquiterpenos/farmacología , Animales , Antiprotozoarios/toxicidad , Membrana Celular/efectos de los fármacos , Membrana Celular/ultraestructura , Femenino , Concentración 50 Inhibidora , Leishmania mexicana/citología , Leishmania mexicana/ultraestructura , Masculino , Ratones , Ratones Endogámicos BALB C , Microscopía Electrónica , Orgánulos/efectos de los fármacos , Orgánulos/ultraestructura , Sesquiterpenos/toxicidad
8.
C R Biol ; 336(8): 400-6, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24018197

RESUMEN

The colleter secretion can be useful to protect plants of Cerrado (Brazilian savanna) biome during the long and pronounced dry season. This study describes the presence of colleters in Tontelea micrantha and represents the first record of these structures in Celastraceae. To investigate colleter structure and their secretory processes, young leaves were collected, fixed, and processed according to conventional techniques for light, and electron microscopy. Colleters were observed at the marginal teeth on the leaf. They produce mucilaginous secretions that spread over the leaf surface. After secretory phase, colleters abscise. The secretory epithelium is uniseriate and composed of elongated cells whose dense cytoplasm is rich in organelles. The ultrastructure of the secretory cells is compatible with the pectin-rich secretion. Observations of the young leaves surface revealed the presence of superficial hydrophilic secretion films that appeared to have the function of maintaining the water status of those organs.


Asunto(s)
Celastraceae/anatomía & histología , Pectinas/metabolismo , Hojas de la Planta/ultraestructura , Mucílago de Planta/metabolismo , Transpiración de Plantas/fisiología , Brasil , Celastraceae/fisiología , Desecación , Ecología , Humedad , Interacciones Hidrofóbicas e Hidrofílicas , Microscopía Electrónica , Orgánulos/ultraestructura , Hojas de la Planta/fisiología , Estaciones del Año , Estrés Fisiológico , Propiedades de Superficie , Temperatura , Agua
9.
Braz. j. microbiol ; 44(3): 839-848, July-Sept. 2013. ilus, graf, tab
Artículo en Inglés | LILACS | ID: lil-699798

RESUMEN

Ethanolic crude extracts prepared from the arils and seeds, pericarp, peels and from the whole fruit of Punica granatum, known as pomegranate, had their antifungal activity tested against Candida spp. The ethanolic crude extracts were analyzed by Mass Spectrometry and yielded many compounds such as punicalagin and galladydilacton. The extracts from the pericarp and peel showed activity against Candida spp., with MICs of 125 µg/mL. The effect of pericarp and peel extracts upon the morphological and structure of C. albicans and C. krusei were examined by scanning and transmission electron microscopy, with the visualization of an irregular membrane and hyphae, formation of vacuoles and thickening of the cell wall. The data obtained revealed potential antimicrobial activity against yeasts cells of the Candida genus, and the bioactive compounds could be responsible for changes in cell morphology and structure. The data obtained open new perspectives for future research in continuation to this study, where information such as determination of the site of action of the compounds could contribute to an alternative therapy against these organisms.


Asunto(s)
Antifúngicos/farmacología , Candida/efectos de los fármacos , Extractos Vegetales/farmacología , Lythraceae/química , Antifúngicos/síntesis química , Antifúngicos/aislamiento & purificación , Candida/ultraestructura , Membrana Celular/efectos de los fármacos , Membrana Celular/ultraestructura , Espectrometría de Masas , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Orgánulos/efectos de los fármacos , Orgánulos/ultraestructura , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación
10.
Acta Trop ; 125(3): 349-56, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23228524

RESUMEN

The currently available treatments for Chagas disease show limited therapeutic potential and are associated with serious side effects. Our group has been attempting to find alternative drugs isolated from natural products as a potential source of pharmacological agents against Trypanosoma cruzi. Here, we demonstrate the antitrypanosomal activity of the amides piperovatine and piperlonguminine isolated from Piper ovatum against epimastigotes and intracellular amastigotes. We also investigated the mechanisms of action of these compounds on extracellular amastigote and epimastigote forms of T. cruzi. These amides showed low toxicity to LLCMK(2) mammalian cells. By using transmission and scanning electron microscopy, we observed that the compounds caused severe alterations in T. cruzi. These alterations were mainly located in plasma membrane and mitochondria. Furthermore, the study of treated parasites labeled with Rh123, PI and MDC corroborate with our TEM data. These mitochondrial dysfunctions induced by the amides might trigger biochemical alterations that lead to cell death. Altogether, our data evidence a possible autophagic process.


Asunto(s)
Antiprotozoarios/farmacología , Autofagia , Dioxolanos/farmacología , Ácido Sórbico/análogos & derivados , Trypanosoma cruzi/efectos de los fármacos , Animales , Antiprotozoarios/toxicidad , Línea Celular , Supervivencia Celular/efectos de los fármacos , Dioxolanos/aislamiento & purificación , Dioxolanos/toxicidad , Humanos , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Orgánulos/efectos de los fármacos , Orgánulos/ultraestructura , Piper/química , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Extractos Vegetales/toxicidad , Ácido Sórbico/aislamiento & purificación , Ácido Sórbico/farmacología , Ácido Sórbico/toxicidad , Trypanosoma cruzi/ultraestructura
11.
Braz J Microbiol ; 44(3): 839-48, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24516425

RESUMEN

Ethanolic crude extracts prepared from the arils and seeds, pericarp, peels and from the whole fruit of Punica granatum, known as pomegranate, had their antifungal activity tested against Candida spp. The ethanolic crude extracts were analyzed by Mass Spectrometry and yielded many compounds such as punicalagin and galladydilacton. The extracts from the pericarp and peel showed activity against Candida spp., with MICs of 125 µg/mL. The effect of pericarp and peel extracts upon the morphological and structure of C. albicans and C. krusei were examined by scanning and transmission electron microscopy, with the visualization of an irregular membrane and hyphae, formation of vacuoles and thickening of the cell wall. The data obtained revealed potential antimicrobial activity against yeasts cells of the Candida genus, and the bioactive compounds could be responsible for changes in cell morphology and structure. The data obtained open new perspectives for future research in continuation to this study, where information such as determination of the site of action of the compounds could contribute to an alternative therapy against these organisms.


Asunto(s)
Antifúngicos/farmacología , Candida/efectos de los fármacos , Lythraceae/química , Extractos Vegetales/farmacología , Antifúngicos/síntesis química , Antifúngicos/aislamiento & purificación , Candida/ultraestructura , Membrana Celular/efectos de los fármacos , Membrana Celular/ultraestructura , Espectrometría de Masas , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Orgánulos/efectos de los fármacos , Orgánulos/ultraestructura , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación
12.
Parasitol Res ; 111(5): 1929-35, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22814769

RESUMEN

Pulsatilla chinensis is a medicinal root plant that has been used to treat a wide range of disease conditions. Our study determined the antiprotozoal activity of various P. chinensis extracts and fractions against Giardia intestinalis including their effects on parasite growth, cell viability, adherence, and morphology. Ethyl acetate extracts (IC50 = 257.081 µg/ml) were the most active to inhibit the growth of G. intestinalis followed by aqueous extract (PWE), saponins, and n-butanol extract. The PWE and ethyl acetate extract inhibited G. intestinalis trophozoites adherence after 3 h of incubation and killed almost 50 % of the parasite population in a time-dependent manner. Changes in morphology, presence of precipitates in the cytoplasm, dissolved cytoplasm with large vacuole, break of flagella and ventral disk, membrane blebs, and intracellular and nuclear clearance of the treated trophozoites were observed by scanning and transmission electron microscopy. We demonstrated that P. chinensis induced these changes in G. intestinalis morphology and consequently has potential therapeutic use against giardiasis.


Asunto(s)
Antiprotozoarios/farmacología , Giardia lamblia/efectos de los fármacos , Extractos Vegetales/farmacología , Pulsatilla/química , Animales , Antiprotozoarios/aislamiento & purificación , Supervivencia Celular/efectos de los fármacos , Giardia lamblia/crecimiento & desarrollo , Giardia lamblia/ultraestructura , Concentración 50 Inhibidora , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Orgánulos/efectos de los fármacos , Orgánulos/ultraestructura , Extractos Vegetales/aislamiento & purificación , Trofozoítos/efectos de los fármacos , Trofozoítos/crecimiento & desarrollo , Trofozoítos/ultraestructura
13.
Micron ; 43(7): 839-50, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22410276

RESUMEN

The ultrastructural analysis of tobacco, potato and pepper tissues during infection with necrotic strains and the ordinary Potato virus Y strain of revealed the presence of virus inclusions not only in the epidermis and mesophyll but also in the vascular tissues. For the first time cytoplasmic inclusions were documented in companion cells and phloem parenchyma as well as in xylem tracheary elements. The ultrastructural features studied in this work consisted of mostly laminated inclusions (in the traverse and longitudinal section), which were frequently connected with enlarged cisternae of endoplasmic reticulum (ER) located in the direct vicinity of the cell wall attached to virus particles opposite to plasmodesmata. It was noticed that ER participates in synthesis and condensation of the PVY inclusions. During compatible interaction of tobacco and potato plants with PVY, amorphous and nuclear inclusions were observed. Such forms were not found in pepper tissues and potato revealing the hypersensitivity reaction to the infection with PVY necrotic strains. It was stated that the forms of cytoplasmic inclusions cannot serve as a cytological criterion to distinguish the potato virus Y strains and do not depend on host resistance level. Only in compatible interaction in Solanaceous plants tissues cytoplasmic inclusions were observed from the moment the morphological symptoms appeared. In the reaction of hypersensitivity, the inclusions were found on the 24th day following the infection with the PVY necrotic strains, whereas the symptoms were observed 3 days after the PVY infection.


Asunto(s)
Capsicum/ultraestructura , Nicotiana/ultraestructura , Enfermedades de las Plantas/virología , Potyvirus/crecimiento & desarrollo , Solanum tuberosum/ultraestructura , Capsicum/virología , Pared Celular/ultraestructura , Citoplasma/ultraestructura , Cuerpos de Inclusión Viral/ultraestructura , Orgánulos/ultraestructura , Solanum tuberosum/virología , Nicotiana/virología
14.
Microsc Res Tech ; 75(5): 586-95, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-21998015

RESUMEN

The present study was designed to evaluate the anticarcinogenic potential of Azadirachta indica against N-nitrosodiethylamine (NDEA)-induced hepatocarcinogenesis. Further, the associated histopathological and ultrastructural changes were also analyzed. Hepatic cancer model was developed by the intraperitoneal administration of NDEA to mice at weekly intervals, in successive increasing doses, for a period of 8 weeks. Aqueous A. indica leaf extract (AAILE) was administered orally at a dosage of 100 µg/g body weight thrice a week till termination of the study. A relationship between histopathological grading and chemopreventive effect of A. indica had been established at various stages of carcinogenesis. Anticancer activity of A. indica was evaluated in terms of tumor incidence, tumor multiplicity, and survival rate. A significant reduction in tumor incidence (33%), tumor multiplicity (42%), and increase in survival (34%) was observed upon administration of AAILE to NDEA-abused mice. Transmission and scanning electron microscopic investigations showed severe alterations in organelle organization, cellular arrangement, degree of differentiation, cellular metabolism, and morphology of the hepatocytes. These changes appeared to be distinctly delayed upon AAILE supplementation. The results suggest A. indica may have anticancer potential against NDEA-induced hepatic cancer.


Asunto(s)
Antineoplásicos/administración & dosificación , Azadirachta/química , Quimioprevención/métodos , Neoplasias Hepáticas/prevención & control , Extractos Vegetales/administración & dosificación , Animales , Antineoplásicos/aislamiento & purificación , Carcinógenos/administración & dosificación , Dietilnitrosamina/administración & dosificación , Modelos Animales de Enfermedad , Histocitoquímica , Incidencia , Hígado/patología , Neoplasias Hepáticas/inducido químicamente , Neoplasias Hepáticas/patología , Masculino , Ratones , Ratones Endogámicos BALB C , Microscopía , Orgánulos/ultraestructura , Extractos Vegetales/aislamiento & purificación , Análisis de Supervivencia
15.
Nutrition ; 27(10): 1066-75, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21907898

RESUMEN

OBJECTIVE: Acrylamide (ACR), a proved rodent carcinogen and neurotoxic agent, is present in significant quantities in commonly consumed foods such as fried potato chips (FPC) and French fries, raising a health concern worldwide. We investigated and compared the neurotoxic effects of ACR and FPC on postnatal development. METHODS: Female rats were treated with ACR (30 mg/kg of body weight), fed a diet containing approximately 30% of FPC during pregnancy, or fed a standard diet (control) and their offspring were examined. RESULTS: Female rats treated with ACR or fed a diet containing FPC during pregnancy gave birth to litters with delayed growth and decreased body and brain weights. Light microscopic studies of the cerebellar cortex of treated animals revealed drastic decreases in Purkinje cells and internal granular layers. Different patterns of cell death were detected in Purkinje cells and neurons in the brains of pups born to treated mothers. Ultrastructural analysis of Purkinje cells revealed changes in the endoplasmic reticulum, loss of the normal arrangement of polyribosomes, swollen mitochondria with abnormally differentiated cristae, and an abnormal Golgi apparatus. The gastrocnemius muscle in the ACR and FPC groups showed extensive degeneration of myofibrils as evidenced by poorly differentiated A, H, and Z bands. CONCLUSION: The present study reveals for the first time that rat fetal exposure to ACR, as a pure compound or from a maternal diet of FPC, causes cerebellar cortical defects and myodegeneration of the gastrocnemius muscle during the postnatal development of pups. These results warrant a systematic study of the health effects of the consumption of FPC and French fries in the general population.


Asunto(s)
Acrilamida/efectos adversos , Encéfalo/efectos de los fármacos , Contaminación de Alimentos , Trastornos del Crecimiento/etiología , Neurotoxinas/efectos adversos , Efectos Tardíos de la Exposición Prenatal , Solanum tuberosum , Animales , Peso Corporal/efectos de los fármacos , Encéfalo/crecimiento & desarrollo , Encéfalo/ultraestructura , Muerte Celular/efectos de los fármacos , Culinaria , Dieta , Femenino , Masculino , Ratones , Ratones Endogámicos , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/crecimiento & desarrollo , Músculo Esquelético/patología , Miofibrillas/efectos de los fármacos , Miofibrillas/patología , Tamaño de los Órganos/efectos de los fármacos , Orgánulos/efectos de los fármacos , Orgánulos/ultraestructura , Tubérculos de la Planta , Embarazo , Ratas
16.
Ultrastruct Pathol ; 35(5): 230-8, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21867406

RESUMEN

The detailed ultrastructural changes of uremia-induced hyperplastic parathyroid gland and the effects of current medical treatments for secondary hyperparathyroidism were investigated. Marked enlargement of parathyroid cell with accumulation of mitochondria and lipids and a significant increase in the thickness of the pericapillary area with increased fibrosis and appearance of fibroblast like cells were noted in the hyperplastic gland caused by uremia and phosphate retention. These ultrastructural changes and biochemical findings indicating hyperparathyroidism were significantly suppressed by all of the treatment using phosphate restriction, calcitriol, and cinacalcet. The characteristic ultrastructural changes, including the morphologic evidence of nodule formation, were indicated.


Asunto(s)
Hiperparatiroidismo Secundario/patología , Glándulas Paratiroides/patología , Uremia/patología , Animales , Calcitriol/farmacología , Capilares/ultraestructura , Cinacalcet , Modelos Animales de Enfermedad , Hiperparatiroidismo Secundario/complicaciones , Hiperparatiroidismo Secundario/prevención & control , Hiperplasia , Masculino , Naftalenos/farmacología , Nefrectomía , Orgánulos/ultraestructura , Glándulas Paratiroides/irrigación sanguínea , Glándulas Paratiroides/ultraestructura , Fósforo/deficiencia , Fósforo Dietético/administración & dosificación , Ratas , Ratas Sprague-Dawley , Uremia/complicaciones , Uremia/terapia
17.
J Plant Physiol ; 168(14): 1705-9, 2011 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-21477884

RESUMEN

Mobilization of seed storage reserves is essential for seed germination and seedling establishment. Here, we report that AtDSEL, an Arabidopsis thalianaDAD1-like Seedling Establishment-related Lipase, is involved in the mobilization of storage oils for early seedling establishment. AtDSEL is a cytosolic member of the DAD1-like acylhydrolase family encoded by At4g18550. Bacterially expressed AtDSEL preferentially hydrolyzed 1,3-diacylglycerol and 1-monoacylglycerol, suggesting that AtDSEL is an sn-1-specific lipase. AtDSEL-overexpressing transgenic Arabidopsis plants (35S:AtDSEL) were defective in post-germinative seedling growth in medium without an exogenous carbon source. This phenotype was rescued by the addition of sucrose to the growth medium. In contrast, loss-of-function mutant plants (atdsel-1 and atdsel-2) had a mildly fast-growing phenotype regardless of the presence of an exogenous carbon source. Electron microscopy revealed that 5-day-old 35S:AtDSEL cotyledons retained numerous peroxisomes and oil bodies, which were exhausted in wild-type and mutant cotyledons. The impaired seedling establishment of 35S:AtDSEL was not rescued by the addition of an exogenous fatty acid source, and 35S:AtDSEL seedling growth was insensitive to 2,4-dichlorophenoxybutyric acid, indicating that ß-oxidation was blocked in AtDSEL-overexpressers. These results suggest that AtDSEL is involved in the negative regulation of seedling establishment by inhibiting the breakdown of storage oils.


Asunto(s)
Ácido 2,4-Diclorofenoxiacético/análogos & derivados , Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimología , Lipasa/metabolismo , Aceites de Plantas/metabolismo , Plantones/enzimología , Ácido 2,4-Diclorofenoxiacético/farmacología , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/ultraestructura , Proteínas de Arabidopsis/genética , Cotiledón/genética , Cotiledón/crecimiento & desarrollo , Cotiledón/ultraestructura , Flores/enzimología , Flores/genética , Expresión Génica , Germinación , Lipasa/genética , Mutación , Orgánulos/enzimología , Orgánulos/metabolismo , Orgánulos/ultraestructura , Oxidación-Reducción , Fenotipo , Fosfolipasas A1/genética , Hojas de la Planta/enzimología , Hojas de la Planta/genética , Raíces de Plantas/enzimología , Raíces de Plantas/genética , Raíces de Plantas/crecimiento & desarrollo , Tallos de la Planta/enzimología , Tallos de la Planta/genética , Tallos de la Planta/crecimiento & desarrollo , Plantas Modificadas Genéticamente , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Plantones/genética , Plantones/crecimiento & desarrollo , Plantones/ultraestructura , Semillas/crecimiento & desarrollo , Semillas/metabolismo
18.
Nanomedicine ; 7(2): 137-45, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20732456

RESUMEN

Nanoparticles are being researched as a noninvasive method for selectively killing cancer cells. With particular antibody coatings on nanoparticles, they attach to the abnormal cells of interest (cancer or otherwise). Once attached, nanoparticles can be heated with ultraviolet-visible/infrared or radiofrequency pulses, heating the surrounding area of the cell to its point of death. Researchers often use single-pulse or multi-pulse modes of laser heating when conducting nanoparticle ablation research. In this article, time-dependent simulations and detailed analyses are carried out for different nonstationary pulsed laser-nanoparticle interaction modes, and the advantages and disadvantages of single-pulse and multi-pulse (set of short pulses) laser heating of nanoparticles are shown. Simulations are performed for the metal nanoparticles in the biological surrounding medium as well as for healthy and cancerous cell organelles. FROM THE CLINICAL EDITOR: External laser pulses can be used to generate heating of targeted metal nanoparticles for thermal ablation therapy of cancers, however the approach used in individual studies is idiosyncratic. In this manuscript, time-dependent simulations and analyses are used to determine the pros and cons of single versus multiple laser pulses for differential impact of healthy versus cancerous cell organelles.


Asunto(s)
Oro/metabolismo , Terapia por Láser/métodos , Nanopartículas del Metal , Modelos Biológicos , Neoplasias/cirugía , Orgánulos/metabolismo , Cinética , Nanomedicina/métodos , Neoplasias/metabolismo , Neoplasias/ultraestructura , Orgánulos/ultraestructura , Fototerapia
19.
Plant Cell Physiol ; 51(6): 896-911, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20484369

RESUMEN

The pollen coat is a surface component of pollen grains required for fertilization. To study how the pollen coat is produced, we identified and characterized a recessive and conditional male-sterile Arabidopsis mutant, flaky pollen1-1 (fkp1-1), whose pollen grains lack functional pollen coats. FKP1 is a single-copy gene in the Arabidopsis genome and encodes 3-hydroxy-3-methylglutaryl-coenzyme A synthase (HMG-CoA synthase), an enzyme of the mevalonate (MVA) pathway involved in biosynthesis of isoprenoids such as sterols. We found that fkp1-1 possesses a T-DNA insertion 550 bp upstream of the initiation codon. RT-PCR and promoter analyses revealed that fkp1-1 results in knockdown of FKP1 predominantly in tapetum. Electron microscopy showed that the mutation affected the development of tapetum-specific lipid-containing organelles (elaioplast and tapetosome), causing the deficient formation of fkp1-1 pollen coats. These results suggest that both elaioplasts, which accumulate vast amount of sterol esters, and tapetosomes, which are unique oil-accumulating structures, require the MVA pathway for development. Null alleles of fkp1 were male-gametophyte lethal upon pollen tube elongation, whereas female gametophytes were normal. These results show that the MVA pathway is essential, at least in tapetal cells and pollen grains, for the development of tapetum-specific organelles and the fertility of pollen grains.


Asunto(s)
Acilcoenzima A/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Polen/crecimiento & desarrollo , Acilcoenzima A/genética , Proteínas de Arabidopsis/genética , Clonación Molecular , ADN Bacteriano/genética , Perfilación de la Expresión Génica , Genes de Plantas , Microscopía Electrónica de Transmisión , Mutagénesis Insercional , Mutación , Orgánulos/enzimología , Orgánulos/ultraestructura , Infertilidad Vegetal , Plantas Modificadas Genéticamente/enzimología , Plantas Modificadas Genéticamente/genética , Polen/enzimología , Polen/genética , Regiones Promotoras Genéticas
20.
Ultrastruct Pathol ; 34(3): 140-60, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20455663

RESUMEN

A human bladder carcinoma cell line RT4 was sham-treated with buffer or treated with ascorbate (VC) alone, menadione alone (VK(3)), or a combination of ascorbate:menadione (VC+VK(3)) for 1, 2, and 4 h. Cytotoxic damage was found to be treatment-dependent in this sequence: VC+VK(3)>VC>VK(3)>sham. The combined treatment induced the greatest oxidative stress, with early tumor cell injury affecting the cytoskeletal architecture and contributing to the self-excisions of pieces of cytoplasm freed from organelles. Additional damage, including a reduction in cell size, organelle alterations, nuclear damage, and nucleic acid degradation as well as compromised lysosome integrity, is caused by reactivation of DNases and the redox cycling of VC or VC+VK(3). In addition, cell death caused by VC+VK(3) treatment as well as by prolonged VC treatment is consistent with cell demise by autoschizis, not apoptosis. This report confirms and complements previous observations about this new mode of tumor cell death. It supports the contention that a combination of VC+VK(3), also named Apatone, could be co-administered as a nontoxic adjuvant with radiation and/or chemotherapies to kill bladder tumor cells and other cancer cells without any supplementary risk or side effects for patients.


Asunto(s)
Antineoplásicos/farmacología , Ácido Ascórbico/farmacología , Muerte Celular/efectos de los fármacos , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Vitamina K 3/farmacología , Línea Celular Tumoral , Núcleo Celular/efectos de los fármacos , Núcleo Celular/ultraestructura , Supervivencia Celular/efectos de los fármacos , Daño del ADN , Ensayos de Selección de Medicamentos Antitumorales , Quimioterapia Combinada , Humanos , Masculino , Microscopía Electrónica de Transmisión , Orgánulos/efectos de los fármacos , Orgánulos/ultraestructura , Estrés Oxidativo/efectos de los fármacos , Neoplasias de la Vejiga Urinaria/metabolismo , Neoplasias de la Vejiga Urinaria/patología
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