Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 103
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Angiogenesis ; 21(4): 883-900, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30014172

RESUMEN

VEGF induces normal or aberrant angiogenesis depending on its dose in the microenvironment around each producing cell in vivo. This transition depends on the balance between VEGF-induced endothelial stimulation and PDGF-BB-mediated pericyte recruitment, and co-expression of PDGF-BB normalizes aberrant angiogenesis despite high VEGF doses. We recently found that VEGF over-expression induces angiogenesis in skeletal muscle through an initial circumferential vascular enlargement followed by longitudinal splitting, rather than sprouting. Here we investigated the cellular mechanism by which PDGF-BB co-expression normalizes VEGF-induced aberrant angiogenesis. Monoclonal populations of transduced myoblasts, expressing similarly high levels of VEGF alone or with PDGF-BB, were implanted in mouse skeletal muscles. PDGF-BB co-expression did not promote sprouting and angiogenesis that occurred through vascular enlargement and splitting. However, enlargements were significantly smaller in diameter, due to a significant reduction in endothelial proliferation, and retained pericytes, which were otherwise lost with high VEGF alone. A time-course of histological analyses and repetitive intravital imaging showed that PDGF-BB co-expression anticipated the initiation of vascular enlargement and markedly accelerated the splitting process. Interestingly, quantification during in vivo imaging suggested that a global reduction in shear stress favored the initiation of transluminal pillar formation during VEGF-induced splitting angiogenesis. Quantification of target gene expression showed that VEGF-R2 signaling output was significantly reduced by PDGF-BB co-expression compared to VEGF alone. In conclusion, PDGF-BB co-expression prevents VEGF-induced aberrant angiogenesis by modulating VEGF-R2 signaling and endothelial proliferation, thereby limiting the degree of circumferential enlargement and enabling efficient completion of vascular splitting into normal capillary networks despite high VEGF doses.


Asunto(s)
Becaplermina/metabolismo , Proliferación Celular , Células Endoteliales , Músculo Esquelético , Neovascularización Fisiológica , Factor A de Crecimiento Endotelial Vascular/metabolismo , Animales , Células Endoteliales/citología , Células Endoteliales/metabolismo , Ratones , Ratones SCID , Músculo Esquelético/irrigación sanguínea , Músculo Esquelético/citología , Músculo Esquelético/metabolismo , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismo
2.
Phys Rev Lett ; 121(4): 041802, 2018 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-30095943

RESUMEN

A novel mechanism to produce and detect light dark matter in experiments making use of GeV electrons (and positrons) impinging on a thick target (beam dump) is proposed. The positron-rich environment produced by the electromagnetic shower allows us to produce an A^{'} via nonresonant (e^{+}+e^{-}→γ+A^{'}) and resonant (e^{+}+e^{-}→A^{'}) annihilation on atomic electrons. The latter mechanism, for some selected kinematics, results in a larger sensitivity with respect to limits derived by the commonly used A^{'}-strahlung. This idea, applied to beam-dump experiments and active beam-dump experiments, pushes down the current limits by an order of magnitude.

3.
World J Microbiol Biotechnol ; 33(6): 128, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28550527

RESUMEN

Yeasts were isolated from three vineyards located in the South Region of Brazil. A cross evaluation was carried out at the oldest vineyard of the study in Pinheiro Preto. Samples of grape berries, grapevine leaves and the soil, along with samples of the winery equipment and effluent, were collected. In the Serra do Marari and Campos Novos vineyards only samples of grape clusters were obtained. The 106 yeast isolates were identified by sequencing the D1/D2 domain of LSU rDNA or ITS1-5.8S-ITS2 region in 22 species. The values for the richness indices varied between the vineyards. A comparison of the taxonomic diversity of the yeasts from these regions using the reciprocal Simpson index showed a significant difference between the Serra do Marari and Campos Novos vineyards (5.72 ± 0.36 and 2.92 ± 0.36, respectively, p < 0.0001). The functional diversity was assessed in relation to the use of carbon and nitrogen sources by the yeasts isolated from each location. In general, we observed that the Pinheiro Preto and Campos Novos vineyards differed consistently from the Serra do Marari vineyard according to these indices (FAD2, FDc and Rao, p < 0.0001). The possible spreading of Saccharomyces cerevisiae from the winery to the vineyard in Pinheiro Preto was observed.


Asunto(s)
Microbiología Ambiental , Granjas , Microbiología del Suelo , Levaduras/clasificación , Levaduras/aislamiento & purificación , Biodiversidad , Brasil , Carbono/metabolismo , ADN de Hongos/genética , ADN Ribosómico/genética , Filogenia , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crecimiento & desarrollo , Saccharomyces cerevisiae/aislamiento & purificación , Suelo , Especificidad de la Especie , Levaduras/genética , Levaduras/crecimiento & desarrollo
4.
Phys Rev Lett ; 108(21): 214503, 2012 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-23003267

RESUMEN

It is experimentally shown that the nonclassical high Reynolds number energy dissipation behavior, C(ε)≡εL/u(3)=f(Re(M))/Re(L), observed during the decay of fractal square grid-generated turbulence (where Re(M) is a global inlet Reynolds number and Re(L) is a local turbulence Reynolds number) is also manifested in decaying turbulence originating from various regular grids. For sufficiently high values of the global Reynolds numbers Re(M), f(Re(M))~Re(M).

5.
Sci Rep ; 12(1): 9310, 2022 06 03.
Artículo en Inglés | MEDLINE | ID: mdl-35661130

RESUMEN

The Iberian hare (Lepus granatensis) is an endemic species of the Iberian Peninsula and the only hare species found in Portugal, although also being present in some areas of Spain. The reduction of wild hare populations due to several ecological and sanitary factors, has been raising growing concerns in the recent years. Despite different helminth species were already described in Iberian hares in Portugal, to this date, no filarial worms have been identified in this species. Furthermore, only a few studies on lagomorphs' onchocercid worms are available, referring to other hosts species of hares and/or rabbits. In this study, we describe the presence of filarial worms in the blood vessels of two adult Iberian hares collected in 2019 in continental Portugal. Morphology and sequencing data from the 12S rRNA, coxI, 18S rRNA, myoHC, hsp70 and rbp1 genes, showed that the filaroid species were genetically related with Micipsella numidica. However, the extension of the genetic differences found with M. numidica suggests that the filaroids specimens under study belong to a new species, that we provisionally named Micipsella iberica n. sp.. The body location of this putative new parasite species and its physiological implications indicate that it may constitute a potential menace to the already fragile Iberian hare justifying, therefore, further investigation regarding the morphological characterization, prevalence and real clinical impact of this new parasite in hares.


Asunto(s)
Filarioidea , Liebres , Animales , Europa (Continente) , Filarioidea/genética , Liebres/genética , Portugal , ARN Ribosómico , Conejos
6.
FASEB J ; 24(6): 1958-70, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20179142

RESUMEN

Transient receptor potential vanilloid (TRPV1) transduces noxious chemical and physical stimuli in high-threshold nociceptors. The pivotal role of TRPV1 in the physiopathology of pain transduction has thrust the identification and characterization of interacting partners that modulate its cellular function. Here, we report that TRPV1 associates with gamma-amino butyric acid A-type (GABA(A)) receptor associated protein (GABARAP) in HEK293 cells and in neurons from dorsal root ganglia coexpressing both proteins. At variance with controls, GABARAP augmented TRPV1 expression in cotransfected cells and stimulated surface receptor clustering. Functionally, GABARAP expression attenuated voltage and capsaicin sensitivity of TRPV1 in the presence of extracellular calcium. Furthermore, the presence of the anchor protein GABARAP notably lengthened the kinetics of vanilloid-induced tachyphylaxia. Notably, the presence of GABARAP selectively increased the interaction of tubulin with the C-terminal domain of TRPV1. Disruption of tubulin cytoskeleton with nocodazole reduced capsaicin-evoked currents in cells expressing TRPV1 and GABARAP, without affecting the kinetics of vanilloid-induced desensitization. Taken together, these findings indicate that GABARAP is an important component of the TRPV1 signaling complex that contributes to increase the channel expression, to traffic and cluster it on the plasma membrane, and to modulate its functional activity at the level of channel gating and desensitization.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Ganglios Espinales/metabolismo , Activación del Canal Iónico/fisiología , Proteínas Asociadas a Microtúbulos/metabolismo , Canales Catiónicos TRPV/metabolismo , Proteínas Reguladoras de la Apoptosis , Calcio/metabolismo , Capsaicina/farmacología , Membrana Celular/metabolismo , Células Cultivadas , Citosol/efectos de los fármacos , Citosol/metabolismo , Electrofisiología , Biblioteca de Genes , Humanos , Técnicas para Inmunoenzimas , Activación del Canal Iónico/efectos de los fármacos , Riñón/citología , Riñón/metabolismo , Fármacos del Sistema Sensorial/farmacología , Tubulina (Proteína)/metabolismo , Técnicas del Sistema de Dos Híbridos
7.
Int J Drug Policy ; 90: 103080, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33340947

RESUMEN

BACKGROUND: Harm reduction services, which typically provide overdose education and prevention with distribution of naloxone and other supplies related to safer drug use, help reduce opioid-related overdose and infectious disease transmission. However, structural stigma and the ongoing criminalization of drug use have limited the expansion of harm reduction services into many non-urban communities in the United States that have been increasingly affected by the health consequences of opioid and polysubstance use. METHODS: We conducted qualitative interviews with 22 professionals working with people who use drugs in cities and towns across Rhode Island and Massachusetts to understand challenges and strategies for engaging communities in accepting harm reduction perspectives and services. RESULTS: Our thematic analysis identified several interrelated challenges to implementing harm reduction services in non-urban communities, including: (1) limited understandings of harm reduction practice and preferential focus on substance use treatment and primary prevention, (2) community-level stigma against people who use drugs as well as the agencies supporting them, (3) data reporting and aggregating leading to inaccurate perceptions about local patterns of substance use and related health consequences, and (4) a "prosecutorial mindset" against drug use and harm reduction. From key informants' narratives, we also identified specific strategies that communities could use to address these challenges, including: (1) identifying local champions to advocate for harm reduction strategies, (2) proactively educating communities about harm reduction approaches before they are implemented, (3) improving the visibility of harm reduction services within communities, and (4) obtaining "buy-in" from a wide range of local stakeholders including law enforcement and local government. CONCLUSION: These findings carry important implications for expanding harm reduction services, including syringe service programs and safe injection sites, into non-urban communities that have a demonstrated need for evidence-based interventions to reduce drug-related overdose and infectious disease transmission.


Asunto(s)
Analgésicos Opioides , Sobredosis de Droga , Reducción del Daño , Humanos , Massachusetts , Rhode Island
8.
Phys Rev Lett ; 104(17): 174801, 2010 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-20482112

RESUMEN

The electron-positron collider DAPhiNE, the Italian Phi factory, has been recently upgraded in order to implement an innovative collision scheme based on large crossing angle, small beam sizes at the crossing point, and compensation of beam-beam interaction by means of sextupole pairs creating a "crab-waist" configuration in the interaction region. Experimental tests of the novel scheme exhibited an increase by a factor of 3 in the peak luminosity of the collider with respect to the performances reached before the upgrade. In this Letter we present the new collision scheme, discuss its advantages, describe the hardware modifications realized for the upgrade, and report the results of the experimental tests carried out during commissioning of the machine in the new configuration and standard operation for the users.

9.
Hernia ; 12(1): 57-63, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17851727

RESUMEN

BACKGROUND: Aim of this study was to analyze long-term sequelae, risk factors, and satisfaction after inguinal hernia primary repair. METHODS: A postal questionnaire was mailed to all patients operated between January 1997 and December 2004 for inguinal hernia repair. Patients who had a lump in the groin and patients who experienced chronic problems were invited for a physical examination. Patients who reported having chronic pain were asked to fill out the short-form McGill Pain Questionnaire (SF-MPQ). RESULTS: Chronic pain was present in 18.1% of cases. The strongest risk factors were presence of recurrence, use of heavyweight mesh, and age younger than 66 years. By means of the SF-MPQ, we found that the pain reported by most patients was sensory-discriminative in quality, with "tender" and "aching" being the most common descriptors used. About 71.3% of replies used descriptors typical of nociceptive pain, 8.9% of neuropathic pain, and 19.8% of nociceptive plus neuropathic. Chronic pain was severe in 2.1% of patients and interfered with normal activities, work, and exercise. The cumulative recurrence rate was 2.1%. There was a strong correlation between lump and recurrence. Patients declared themselves satisfied with the result of the operation in 93.1% of cases. Due to chronic pain, 6.5% of patients were unsatisfied. CONCLUSIONS: This study demonstrates that the main problem after inguinal hernia repair remains chronic pain, which was the primary reason of dissatisfaction. The SF-MPQ is feasible and easy to administer to all patients and provides important information about qualitative features of the pain.


Asunto(s)
Hernia Inguinal/cirugía , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Dolor Postoperatorio , Satisfacción del Paciente , Recurrencia , Factores de Riesgo , Mallas Quirúrgicas , Encuestas y Cuestionarios
10.
Fetal Diagn Ther ; 23(4): 293-8, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18417995

RESUMEN

OBJECTIVE: To develop a new endoscopic approach to the correction of a myelomeningocele-like defect in fetal sheep. METHODS: The fetuses of 9 pregnant ewes, with an average gestational age of 115 days, were subjected to a 3.0 x 2.0 cm removal of the skin over the lumbar spine, performed through hysterotomy. The uterus was closed, and three 5-mm endoscopic cannulas, without valve mechanisms, were inserted. In the pilot phase (2 animals), we initially worked exclusively in the amniotic fluid space. In the study phase, we partially withdrew the fetus from the amniotic fluid to completely expose its back. By simply allowing air to enter the amniotic cavity (without gas injection), a working space was created using a uterine lift device. The skin around the defect was dissected, and a biosynthetic cellulose material was applied to cover the area. A continuous suture of the skin was performed to completely hide the material. RESULTS: The combined air/fluid space allowed the skin to be successfully closed in 6 out of 7 cases in the study phase. All fetuses were alive at the end of the procedures. Time to complete the endoscopic part of the procedure fell from 3 to 1 h by the end of this series. Premature birth occurred in 2 of the 4 cases allowed to continue with the pregnancy. CONCLUSION: A new gasless fetoscopic surgery technique was developed as an alternative to current techniques used for fetal endoscopic surgery.


Asunto(s)
Fetoscopía/métodos , Disrafia Espinal/cirugía , Animales , Modelos Animales de Enfermedad , Femenino , Humanos , Región Lumbosacra , Meningomielocele/cirugía , Proyectos Piloto , Embarazo , Ovinos , Anomalías Cutáneas/cirugía
11.
J Mycol Med ; 28(1): 29-35, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29525269

RESUMEN

Invasive fusariosis has a high mortality and is predominantly observed in patients with leukemia. We report the first case of a novel species of Fusarium, Fusarium riograndense sp. nov, isolated from a lesion in the nasal cavity lesion of a patient with acute lymphoblastic leukemia. The etiological agent was identified by Multilocus Sequencing Typing (MLST), including RPB2, TEF-1α, and ITS-LSU sequences, the gold standard technique to identify new species of Fusarium. MLST and phenotypic data strongly supported its inclusion in the F. solani species complex (FSSC). The new species produced a red pigment in the Sabouraud Dextrose Agar similar to other members of the complex. The macroconiodia developed from phialides on multibranched conidiophores which merge to form effuse sporodochia with a basal foot-cell instead of papilla in basal cell shape. The microconidia were ellipsoidal, 0-1-septated, produced from long monophialides. Chlamydospores were produced singly or in pairs. Amphotericin B (MIC 1µg/mL) was the most active drug, followed by voriconazole (MIC 8µg/mL). The patient was successfully treated with voriconazole. Our findings indicate another lineage within FSSC capable causing of invasive human infection.


Asunto(s)
Fusarium/genética , Fusarium/aislamiento & purificación , Rinitis/microbiología , Sinusitis/microbiología , Anfotericina B/farmacología , Anfotericina B/uso terapéutico , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Niño , Fusariosis/microbiología , Fusarium/clasificación , Fusarium/efectos de los fármacos , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus/métodos , Nariz/microbiología , Filogenia , Rinitis/tratamiento farmacológico , Rinitis/etiología , Análisis de Secuencia de ADN , Sinusitis/tratamiento farmacológico , Sinusitis/etiología , Esporas Fúngicas/efectos de los fármacos , Esporas Fúngicas/ultraestructura
12.
Mol Neurobiol ; 55(6): 4959-4972, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28786015

RESUMEN

Homeostatic plasticity is a regulatory feedback response in which either synaptic strength or intrinsic excitability can be adjusted up or down to offset sustained changes in neuronal activity. Although a growing number of evidences constantly provide new insights into these two apparently distinct homeostatic processes, a unified molecular model remains unknown. We recently demonstrated that REST is a transcriptional repressor critical for the downscaling of intrinsic excitability in cultured hippocampal neurons subjected to prolonged elevation of electrical activity. Here, we report that, in the same experimental system, REST also participates in synaptic homeostasis by reducing the strength of excitatory synapses by specifically acting at the presynaptic level. Indeed, chronic hyperactivity triggers a REST-dependent decrease of the size of synaptic vesicle pools through the transcriptional and translational repression of specific presynaptic REST target genes. Together with our previous report, the data identify REST as a fundamental molecular player for neuronal homeostasis able to downscale simultaneously both intrinsic excitability and presynaptic efficiency in response to elevated neuronal activity. This experimental evidence adds new insights to the complex activity-dependent transcriptional regulation of the homeostatic plasticity processes mediated by REST.


Asunto(s)
Hipocampo/metabolismo , Homeostasis/fisiología , Plasticidad Neuronal/fisiología , Neuronas/metabolismo , Terminales Presinápticos/fisiología , Proteínas Represoras/metabolismo , Animales , Ratones , Proteínas Represoras/genética , Vesículas Sinápticas/metabolismo
13.
Phys Rev E ; 95(2-1): 023114, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28297878

RESUMEN

Direct numerical simulations of homogeneous decaying turbulence with background rotation show the existence of a systematic and significant imbalance between the non-linear energy cascade to small scales and its dissipation. By starting the decay from a statistically stationary and weakly rotating turbulent state, where the dissipation and the energy flux are approximately equal, the data show a growing imbalance between the two until a maximum is reached when the dissipation is about twice the energy flux. This dichotomy of behaviors during decay is reminiscent of the nonequilibrium and the equilibrium regions previously reported for nonrotating turbulence [Valente and Vassilicos, Phys. Rev. Lett. 108, 214503 (2012)PRLTAO0031-900710.1103/PhysRevLett.108.214503]. Note, however, that for decaying rotating turbulence the classical scaling of the dissipation rate ε∝u^{'3}/L (where u^{'} and L are the root mean square fluctuating velocity and the integral length scale, respectively) does not appear to hold during decay, which may be attributed to the effect of the background rotation on the energy cascade. On the other hand, the maximum energy flux holds the scaling Π_{max}∝u^{'3}/L in the initial stage of the decay until the maximum imbalance is reached.

15.
Int J Immunopathol Pharmacol ; 19(4 Suppl): 61-5, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17291409

RESUMEN

The study is a further follow-up of a cohort of 168 urban pesticide applicators of the municipality of Rome who were first employed in 1946. An earlier analysis of the mortality of this group concerned the deaths observed up to 1987, and showed a significant excess in mortality from liver cancer. In this report we present an updated follow up of the mortality of the cohort, which comprises the total of 85 deaths for the entire period of observation, corresponding to 5227 person/years. The living status of each member of the cohort was ascertained through the official records up to 2005. For the 85 deceased individuals, the primary cause of death was coded according to the 9th Revision of the ICD. Standardized mortality ratios (SMR) were calculated on the basis of the age, sex, and cause specific mortality rates prevailing during the same calendar years in the province of Rome. The SMR from all causes for the whole cohort was 103.8 (90 %CI 86 124). The SMR for all cancers was 106.0 ( 90 % CI 75-146). An increased risk was observed for the exposed for cancer of the gallbladder (SMR 723.8 90% CI 129-2279), of the liver (SMR 596.3, 90 % CI 204-1365) and for cancer of the nervous system (SMR 529.2, 90 % CI 144-1368). All increases were statistically significant, but no association was found between the increased risk of these cancers and the longer duration of exposure. The increase in risk of the three cancers mentioned above (liver, nervous system and gallbladder), was further increased, when the analysis was restricted to the workers exposed prior to the 1978 ban of DDT and products containing arsenic.


Asunto(s)
Neoplasias/mortalidad , Enfermedades Profesionales/mortalidad , Plaguicidas/efectos adversos , Estudios de Cohortes , Estudios de Seguimiento , Humanos , Masculino , Estudios Retrospectivos
16.
Methods Find Exp Clin Pharmacol ; 28(6): 369-72, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16894406

RESUMEN

Coffee, one of the most excessively used beverages worldwide, commences the risk of gastroesophageal reflux (GER), which may lead to gastric ulcers and increase the risk of gastric cancer. Many attempts have been made by the coffee industry to diminish the irritating effect on mucosa by means of altering the extraction methods concerning gerbic acids and the roasting processes. This paper describes the effect of differently produced coffees involving two brands of Darboven and two brands of other coffee roasters. The aim of this study was to prove the results of gastric potential measurements we found in literature by using human AGS gastric epithelial cells (human adenocarcinoma). All four coffee extracts tested differentially affected the membrane resting potential of AGS cells. Coffees no. 1 and no. 2 depolarized the cells, presumably by increasing the cation entry into the cytosol. In marked contrast, coffee no. 4 hyperpolarizes the cells, possibly by H(+) extrusion and/or Cl(-) influx, suggesting that this coffee might increase acidity in the stomach, which might negatively affect the stomach, especially in people with gastroesophageal reflux symptoms. Overall, our data suggest that different roasting methods of coffees affect the membrane potentials of AGS stomach cells, resulting in increased influx of H+ possibly resulting in decreased stomach acidity and thus reducing GER. These results are in good accordance with clinical pharmacological results from potential difference measurements in healthy volunteers we found in the literature.


Asunto(s)
Café , Estómago/citología , Adenocarcinoma/patología , Cationes/análisis , Línea Celular Tumoral , Membrana Celular/efectos de los fármacos , Café/química , Ácido Gástrico/metabolismo , Determinación de la Acidez Gástrica , Humanos , Potenciales de la Membrana/efectos de los fármacos , Técnicas de Placa-Clamp , Extractos Vegetales/farmacología , Estómago/efectos de los fármacos , Neoplasias Gástricas/patología
17.
Oncogene ; 13(6): 1169-78, 1996 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-8808691

RESUMEN

The retinoblastoma gene (RB1) is frequently deleted or mutated in many tumor types and in all cases of retinoblastoma. Apart from its role in regulation of the cell cycle, the RB1 gene product (p110RB1) appears to be involved in control of differentiation. Malignant metastatic cells show many properties of poorly differentiated cells, and are highly invasive in vitro and in vivo. We have transfected the human RB1 cDNA in an expression vector under the control of the beta-actin promoter into B16F10 murine melanoma cells. These cells highly overexpress RB1 mRNA and the p110RB1 product, show reduced growth rate and increased melanogenesis in vitro. Vector control transfectants showed no alteration of invasiveness. The p110RB1 over-expressing cells also had a reduced capacity to migrate and invade through an artificial basement membrane, key characteristics of metastatic cells. When injected into nude mice, the p110RB1 over-expressing cells showed reduced tumor growth and reduced metastatic potential. The few metastasis observed were predominantly melanotic. These data indicate that RB1 gene expression is involved in melanoma cell differentiation and plays a role in downregulation of migration, invasion and metastatic potential of these cells.


Asunto(s)
Melaninas/biosíntesis , Melanoma Experimental/metabolismo , Melanoma Experimental/patología , Proteína de Retinoblastoma/biosíntesis , Animales , División Celular/fisiología , Movimiento Celular , Medios de Cultivo , ADN Complementario/genética , Progresión de la Enfermedad , Expresión Génica , Genes de Retinoblastoma , Humanos , Melanoma Experimental/genética , Ratones , Invasividad Neoplásica , Metástasis de la Neoplasia , Neovascularización Patológica , Fenotipo , Transfección , Células Tumorales Cultivadas
18.
Cell Death Differ ; 11(6): 655-62, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-14963413

RESUMEN

We show that dysregulation of the Cl- homeostasis mediates the staurosporine-induced apoptotic cell death in human ECV304 cells. A pronounced apoptotic volume decrease (AVD), and an increase in plasma membrane Cl- conductance were early (<1 h) events following staurosporine challenge. Both processes were involved in apoptotic death, as demonstrated by the observation that the Cl- channel blocker phloretin inhibited both the staurosporine-evoked Cl- current and AVD, and preserved cell viability. Prolonged incubation (>2 h) with staurosporine caused a decrease in intracellular pH, which, however, was not required for the progression of the apoptotic process, because inhibitors of proton extrusion pathways, which lowered cytoplasmic pH, failed to inhibit both caspase-3 activation and DNA laddering. Moreover, clamping the cytosolic pH to an alkaline value did not prevent the apoptotic cell death. Collectively, these data demonstrate that staurosporine-mediated apoptosis of ECV304 cells is caused by the upregulation of Cl- channel activity and subsequent AVD, but is independent of intracellular acidification.


Asunto(s)
Apoptosis/efectos de los fármacos , Cloro/metabolismo , Inhibidores Enzimáticos/farmacología , Estaurosporina/farmacología , Tamaño de la Célula/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Canales de Cloruro/antagonistas & inhibidores , Canales de Cloruro/metabolismo , Humanos , Técnicas de Placa-Clamp , Canales de Potasio/metabolismo
19.
J Gastroenterol ; 50(8): 903-12, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25516385

RESUMEN

BACKGROUND: The prevalence of childhood obesity is increasing worldwide. Studies in adult populations show that retinal microvascular changes are associated with obesity and components of the metabolic syndrome. In our study we have assessed the effect of body mass index (BMI), metabolic parameters, and adiposity on the retinal microvasculature in children. METHODS: Fifty-four consecutive children with biopsy-proven NAFLD were enrolled in this study. Anthropometric and laboratory parameters were obtained using standardized protocols. Retinal caliber was quantified from digital retinal images using well-known computer-based programs. Twenty-four-hour ambulatory blood pressure monitoring was measured using a standard protocol. RESULTS: In our population, the prevalence of retinopathy was of 53 % (13 males). The 29 patients with retinopathy (mean age 10.91 ± 3.10) showed significantly higher values of triglycerides (mg/day) (105.57 vs. 90.20, p = 0.04), basal insulin (mUI/ml) (17.20 vs. 12.97, p = 0.02), and HOMA-IR (3.37 vs. 2.76, p = 0.04). The patients with a HOMA-IR >2.5 (OR = 3.34, p = 0.02; 95 % IC, 1.07-10.39), and systolic non-dipping (OR 4.16, p = 0.028, 95 % IC, 1.11-13.67), have an increased risk of retinopathy. Moreover, the study of correlation between all stages of liver biopsy (CRN criteria) and the grade of retinopathy showed a positive correlation with fibrosis (r = 0.31) and an NAS score (r = 0.28). CONCLUSIONS: We found an association between metabolic parameters and nocturnal blood pressure on the retinal microvasculature among the obese children with NAFLD. Furthermore, for the first time, we report the positive relationship between hepatic fibrosis in pediatric NAFLD patients and the degree of retinopathy signs.


Asunto(s)
Retinopatía Hipertensiva/etiología , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Vasos Retinianos/patología , Adolescente , Antropometría/métodos , Arterias/anomalías , Arterias/patología , Arterias/fisiopatología , Biopsia , Monitoreo Ambulatorio de la Presión Arterial/métodos , Niño , Femenino , Humanos , Retinopatía Hipertensiva/patología , Retinopatía Hipertensiva/fisiopatología , Inestabilidad de la Articulación/etiología , Inestabilidad de la Articulación/patología , Inestabilidad de la Articulación/fisiopatología , Hígado/patología , Masculino , Enfermedad del Hígado Graso no Alcohólico/patología , Enfermedad del Hígado Graso no Alcohólico/fisiopatología , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Enfermedades Cutáneas Genéticas/etiología , Enfermedades Cutáneas Genéticas/patología , Enfermedades Cutáneas Genéticas/fisiopatología , Malformaciones Vasculares/etiología , Malformaciones Vasculares/patología , Malformaciones Vasculares/fisiopatología
20.
Eur J Cancer ; 39(10): 1468-77, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12826051

RESUMEN

rHuTNF potentiates CPT-cytotoxicity in human ovarian A2780 cells. In this study, we examined the role of NF-kappaB in this potentiation. A pulse-labelled DNA study indicated that the combination CPT+TNF had little effect on the rate of DNA elongation at 6 h after drug removal, whereas CPT alone produced a complete inhibition for at least 6 h after drug removal. Flow cytometry analyses showed that CPT+TNF arrested cells in the G2-M phase, whereas CPT blocked cells in S phase. Looking at the persistence of the NF-kappaB complexes in cells, it appeared that they were still present at 24 h in TNF-treated cells. In contrast, in CPT-treated cells they persisted for 6 h. In CPT+TNF-treated cells, the NF-kappaB complexes disappeared quickly and became undetectable at 6 h. The induction of apoptosis was detected only in the CPT+TNF treated cells (using flow cytometry, a filter binding assay and ApopTag staining). These findings show that TNF, in combination with CPT, reduces the time that NF-kappaB complexes persist in cells likely resulting in the induction of apoptosis.


Asunto(s)
Antineoplásicos Fitogénicos/uso terapéutico , Apoptosis/efectos de los fármacos , Camptotecina/uso terapéutico , FN-kappa B/antagonistas & inhibidores , Neoplasias Ováricas/tratamiento farmacológico , Factor de Necrosis Tumoral alfa/farmacología , ADN/biosíntesis , Femenino , Citometría de Flujo , Humanos , Neoplasias Ováricas/patología , Células Tumorales Cultivadas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA