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1.
Psychosomatics ; 2020 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-34756407

RESUMEN

BACKGROUND: Medical personality change (MPC) is a codable diagnosis (i.e., F07.0) that deserves consideration when a patient is inexplicably no longer "acting like him/herself." Its presentation ranges from subtle to severe and is often characterized by bafflingly poor judgment and impairment in several aspects of a person's life. Despite the global impact that MPC can have on a patient's functioning, occupation, and relationships, this condition receives far less clinical consideration than better known syndromes such as depression or anxiety and is often likely incorrectly formulated as such. OBJECTIVE/METHODS: This article provides a clinically focused review of MPC. We review its clinical assessment followed by a review of its subtypes, which we have categorized to reflect the behavioral correlates of known frontotemporal-subcortical circuits. These include the apathetic type (ventromedial prefrontal cortex), the labile and disinhibited types (orbitofrontal cortex), and the aggressive and paranoid types (medial temporal lobes). RESULTS: For each of these 3 categories, we describe the clinical presentation and review management strategies. For each category, we focus on 3 common causes for MPC-traumatic brain injury, Huntington disease, and brain tumors-which we have selected because clinical features of MPC due to these conditions generalize to many other etiologies of MPC. CONCLUSIONS: MPC warrants clinical attention for the range of dysfunction and distress it can cause. It also deserves further scientific study to better characterize its phenotypes, to tailor instruments for its clinical assessment, and to identify effective treatments.

2.
Proc Natl Acad Sci U S A ; 114(26): E5167-E5176, 2017 06 27.
Artículo en Inglés | MEDLINE | ID: mdl-28611221

RESUMEN

Key mitochondrial functions such as ATP production, Ca2+ uptake and release, and substrate accumulation depend on the proton electrochemical gradient (ΔµH+) across the inner membrane. Although several drugs can modulate ΔµH+, their effects are hardly reversible, and lack cellular specificity and spatial resolution. Although channelrhodopsins are widely used to modulate the plasma membrane potential of excitable cells, mitochondria have thus far eluded optogenetic control. Here we describe a toolkit of optometabolic constructs based on selective targeting of channelrhodopsins with distinct functional properties to the inner mitochondrial membrane of intact cells. We show that our strategy enables a light-dependent control of the mitochondrial membrane potential (Δψm) and coupled mitochondrial functions such as ATP synthesis by oxidative phosphorylation, Ca2+ dynamics, and respiratory metabolism. By directly modulating Δψm, the mitochondria-targeted opsins were used to control complex physiological processes such as spontaneous beats in cardiac myocytes and glucose-dependent ATP increase in pancreatic ß-cells. Furthermore, our optometabolic tools allow modulation of mitochondrial functions in single cells and defined cell regions.


Asunto(s)
Señalización del Calcio/fisiología , Channelrhodopsins/metabolismo , Células Secretoras de Insulina/metabolismo , Potencial de la Membrana Mitocondrial/fisiología , Mitocondrias Cardíacas/metabolismo , Miocitos Cardíacos/metabolismo , Optogenética , Animales , Células HEK293 , Células HeLa , Humanos , Células Secretoras de Insulina/citología , Consumo de Oxígeno/fisiología , Ratas , Ratas Sprague-Dawley
4.
Gut ; 63(4): 598-609, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23793223

RESUMEN

OBJECTIVE: The differential role of the IL-1 agonists, IL-1α, which is mainly cell-associated versus IL-1ß, which is mostly secreted, was studied in colon inflammation. DESIGN: Dextran sodium sulfate (DSS) colitis was induced in mice globally deficient in either IL-1α or IL-1ß, and in wild-type mice, or in mice with conditional deletion of IL-1α in intestinal epithelial cells (IECs). Bone marrow transplantation experiments were performed to assess the role of IL-1α or IL-1ß of myeloid versus colon non-hematopoietic cells in inflammation and repair in acute colitis. RESULTS: IL-1α released from damaged IECs acts as an alarmin by initiating and propagating colon inflammation, as IL-1α deficient mice exhibited mild disease symptoms with improved recovery. IL-1ß is involved in repair of IECs and reconstitution of the epithelial barrier during the resolution of colitis; its deficiency correlates with disease exacerbation. Neutralisation of IL-1α in control mice during acute colitis led to alleviation of clinical and histological manifestations, whereas treatment with rIL-1Ra or anti-IL-1ß antibodies was not effective. Repair after colitis correlated with accumulation of CD8 and regulatory T cells in damaged crypts. CONCLUSIONS: The role of IL-1α and IL-1ß differs in DSS-induced colitis in that IL-1α, mainly of colon epithelial cells is inflammatory, whereas IL-1ß, mainly of myeloid cell origin, promotes healing and repair. Given the dissimilar functions of each IL-1 agonistic molecule, an IL-1 receptor blockade would not be as therapeutically effective as specific neutralising of IL-1α, which leaves IL-1ß function intact.


Asunto(s)
Colitis/fisiopatología , Interleucina-1alfa/fisiología , Interleucina-1beta/fisiología , Animales , Colitis/inducido químicamente , Colitis/patología , Colon/efectos de los fármacos , Colon/patología , Colon/fisiopatología , Sulfato de Dextran/farmacología , Modelos Animales de Enfermedad , Interleucina-1/agonistas , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/patología , Mucosa Intestinal/fisiopatología , Infiltración Leucémica/fisiopatología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Linfocitos T/fisiología
5.
Carcinogenesis ; 35(11): 2555-66, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25142972

RESUMEN

Nuclear factors of activated T cells (NFAT) are critical modulators of cancer cell growth and survival. However, the mechanisms of their oncogenic dysregulation and strategies for targeting in tumors remain elusive. Here, we report coupling of anti- apoptotic NFAT (NFAT2) activation to cholesterol-enriched lipid raft microdomains of malignant melanoma cells and interruption of this pathway by the aminobisphosphonate zoledronic acid (Zol). The pathway was indicated by capability of Zol to promote apoptosis and to retard in vivo outgrowth of tumorigenic melanoma cell variants through inhibition of permanently active NFAT2. NFAT2 inhibition resulted from disintegration of cholesterol-enriched rafts due to reduction of cellular cholesterol by Zol. Mechanistically, raft disruption abolished raft-localized robust store-operated Ca(2+) (SOC) entry, blocking constitutive activation of protein kinase B/Akt (PKB) and thereby reactivating the NFAT repressor glycogen synthase kinase 3ß (GSK3ß). Pro-apoptotic inactivation of NFAT2 also followed reactivation of GSK3ß by direct inhibition of PKB or SOC, whereas GSK3ß blockade prevented Zol-induced NFAT2 inhibition and cell death. The rescuing effect of GSK3ß blockade was reproduced by recovery of entire SOC/PKB/GSK3ß cascade after reconstitution of rafts by cholesterol replenishment of Zol-treated tumorigenic cells. Remarkably, these malignant cells displayed higher cholesterol and lipid raft content than non-tumorigenic cells, which expressed weak SOC, PKB and NFAT2 activities and resisted raft-ablating action of Zol. Together, the results underscore the functional relevance of amplified melanoma rafts for tumor-promoting NFAT2 signaling and reveal these distinctive microdomains as a target for in vitro and in vivo demise of tumorigenic cells through NFAT2 inhibition by the clinical agent Zol.


Asunto(s)
Proliferación Celular/efectos de los fármacos , Melanoma Experimental/metabolismo , Microdominios de Membrana/metabolismo , Factores de Transcripción NFATC/metabolismo , Animales , Apoptosis/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Colesterol/metabolismo , Difosfonatos/administración & dosificación , Citometría de Flujo , Humanos , Imidazoles/administración & dosificación , Melanoma Experimental/genética , Melanoma Experimental/patología , Microdominios de Membrana/genética , Ratones , Factores de Transcripción NFATC/antagonistas & inhibidores , Factores de Transcripción NFATC/genética , Transducción de Señal/efectos de los fármacos , Ácido Zoledrónico
6.
Environ Sci Technol ; 48(10): 6035-42, 2014 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-24749989

RESUMEN

Costs, emissions, and resource availability were modeled for the production of 5 billion gallons yr(-1) (5 BGY) of renewable diesel in the United States from Chlorella biomass by hydrothermal liquefaction (HTL). The HTL model utilized data from a continuous 1-L reactor including catalytic hydrothermal gasification of the aqueous phase, and catalytic hydrotreatment of the HTL oil. A biophysical algae growth model coupled with weather and pond simulations predicted biomass productivity from experimental growth parameters, allowing site-by-site and temporal prediction of biomass production. The 5 BGY scale required geographically and climatically distributed sites. Even though screening down to 5 BGY significantly reduced spatial and temporal variability, site-to-site, season-to-season, and interannual variations in productivity affected economic and environmental performance. Performance metrics based on annual average or peak productivity were inadequate; temporally and spatially explicit computations allowed more rigorous analysis of these dynamic systems. For example, 3-season operation with a winter shutdown was favored to avoid high greenhouse gas emissions, but economic performance was harmed by underutilized equipment during slow-growth periods. Thus, analysis of algal biofuel pathways must combine spatiotemporal resource assessment, economic analysis, and environmental analysis integrated over many sites when assessing national scale performance.


Asunto(s)
Contaminantes Atmosféricos/análisis , Contaminantes Atmosféricos/economía , Biocombustibles/análisis , Biocombustibles/economía , Chlorella/metabolismo , Biomasa , Costos y Análisis de Costo , Gasolina/análisis , Gasolina/economía , Geografía , Efecto Invernadero , Estados Unidos
7.
Rev Med Suisse ; 10(438): 1485-9, 2014 Aug 13.
Artículo en Francés | MEDLINE | ID: mdl-25199222

RESUMEN

Shock is a hemodynamic situation that aggravates the vital prognostic of every patient regardless of the underlying pathology. It has been well documented that the speed at which hemodynamics is restored to standard values significantly decreases the mortality and morbidity in these patients. Initially described in traumatology, then in every type of shock, the contribution of ultrasonography performed at the bedside by the physician in charge allows for a significant shortening of the diagnostic procedure and thus an earlier start for a goal-directed treatment.


Asunto(s)
Choque/etiología , Abdomen/diagnóstico por imagen , Vasos Sanguíneos/diagnóstico por imagen , Protocolos Clínicos , Ecocardiografía , Humanos , Pulmón/diagnóstico por imagen , Sistemas de Atención de Punto , Choque/diagnóstico
8.
Conscious Cogn ; 22(3): 1003-12, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23911902

RESUMEN

The current research investigates the interaction between thought suppression and individuals' explicit awareness of their thoughts. Participants in three experiments attempted to suppress thoughts of a prior romantic relationship and their success at doing so was measured using a combination of self-catching and experience-sampling. In addition to thoughts that individuals spontaneously noticed, individuals were frequently caught engaging in thoughts of their previous partner at experience-sampling probes. Furthermore, probe-caught thoughts were: (i) associated with stronger decoupling of attention from the environment, (ii) more likely to occur under cognitive load, (iii) more frequent for individuals with a desire to reconcile, and (iv) associated with individual differences in the tendency to suppress thoughts. Together, these data suggest that individuals can lack meta-awareness that they have begun to think about a topic they are attempting to suppress, providing novel insight into the cognitive processes that are involved in attempting to control undesired mental states.


Asunto(s)
Atención/fisiología , Estado de Conciencia/fisiología , Inhibición Psicológica , Represión Psicológica , Pensamiento/fisiología , Inconsciente en Psicología , Femenino , Humanos , Masculino , Adulto Joven
9.
Proc Natl Acad Sci U S A ; 107(1): 436-41, 2010 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-20018762

RESUMEN

Mitochondrial Ca(2+) efflux is linked to numerous cellular activities and pathophysiological processes. Although it is established that an Na(+)-dependent mechanism mediates mitochondrial Ca(2+) efflux, the molecular identity of this transporter has remained elusive. Here we show that the Na(+)/Ca(2+) exchanger NCLX is enriched in mitochondria, where it is localized to the cristae. Employing Ca(2+) and Na(+) fluorescent imaging, we demonstrate that mitochondrial Na(+)-dependent Ca(2+) efflux is enhanced upon overexpression of NCLX, is reduced by silencing of NCLX expression by siRNA, and is fully rescued by the concomitant expression of heterologous NCLX. NCLX-mediated mitochondrial Ca(2+) transport was inhibited, moreover, by CGP-37157 and exhibited Li(+) dependence, both hallmarks of mitochondrial Na(+)-dependent Ca(2+) efflux. Finally, NCLX-mediated mitochondrial Ca(2+) exchange is blocked in cells expressing a catalytically inactive NCLX mutant. Taken together, our results converge to the conclusion that NCLX is the long-sought mitochondrial Na(+)/Ca(2+) exchanger.


Asunto(s)
Calcio/metabolismo , Mitocondrias/metabolismo , Intercambiador de Sodio-Calcio/metabolismo , Sodio/metabolismo , Animales , Encéfalo/citología , Encéfalo/metabolismo , Clonazepam/análogos & derivados , Clonazepam/metabolismo , Homeostasis , Humanos , Ratones , Mitocondrias/ultraestructura , Membranas Mitocondriales/metabolismo , Membranas Mitocondriales/ultraestructura , Miocardio/citología , Miocardio/metabolismo , Ratas , Intercambiador de Sodio-Calcio/antagonistas & inhibidores , Intercambiador de Sodio-Calcio/genética , Tiazepinas/metabolismo
10.
Carcinogenesis ; 33(4): 740-50, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22287561

RESUMEN

Central role of constitutively active protein kinase B/Akt (PKB) in melanoma drives the search for new targets to abolish its deranged signaling. PKB activation is promoted by cholesterol-enriched lipid rafts and is Ca(2+)-dependent, but the pathway linking rafts and Ca(2+) to deregulation of this enzyme remains poorly understood. Here employing B16BL6 melanoma model, we show that ablation of rafts with methyl-ß-cyclodextrin (MßCD) inactivated PKB by inhibiting Src kinase and reactivating the negative PKB modulator, PP2A phosphatase. Blockade of PP2A with okadaic acid rescued PKB, indicating that raft ablation reactivated PP2A through inhibiting Src. Indeed, direct Src blockade with the Src kinase inhibitor-1 or the dominant-negative Src-mutant was sufficient for PP2A reactivation and downregulation of PKB, whereas reconstitution of rafts in MßCD-treated cells restored PKB, PP2A and Src activities to their basal levels. This pathway was also interrupted by inhibition of the Ca(2+) sensor calmodulin, either by its antagonist N-(6-aminohexyl)-5-chloro-1-naphtalenesulfonamide or the Ca(2+)-insensitive calmodulin-mutant or the intracellular Ca(2+)-chelator 1,2-bis(o-aminophenoxy)ethane-N,N,N#N#-tetraacetic acid tetra-(acetocymethyl)-ester or by diminishing the store-operated Ca(2+) entry with 2-aminoethoxydiphenyl borate or small hairpin RNA against Stim1. Ablation of rafts prevented Stim1-mediated store-operated Ca(2+) entry, aborted Ca(2+) stimulation of raft-residing calmodulin and disrupted its Ca(2+)-dependent binding to Src, abolishing Src activity and entire Src/PP2A/PKB cascade. Most importantly, blockade of this cascade in the tumor site by raft-ablating MßCD, administered to melanoma-bearing mice, robustly retarded tumor growth and extended animal survival. Together, our data suggest that lipid rafts couple store-operated Ca(2+) entry to sustained activation of major tumor-promoting signaling elements in melanoma cells and underscore the potential of raft-targeting agents as effective anticancer drugs.


Asunto(s)
Calcio/metabolismo , Calmodulina/metabolismo , División Celular , Melanoma Experimental/metabolismo , Microdominios de Membrana , Proteína Fosfatasa 2/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Familia-src Quinasas/metabolismo , Animales , Línea Celular Tumoral , Activación Enzimática , Citometría de Flujo , Inmunohistoquímica , Transporte Iónico , Melanoma Experimental/enzimología , Melanoma Experimental/patología , Ratones , Ratones Endogámicos C57BL
12.
Rev Med Suisse ; 7(290): 813-6, 2011 Apr 13.
Artículo en Francés | MEDLINE | ID: mdl-21595312

RESUMEN

We present here a case of severe haemoptysis occurring 2 times in a man having some anomaly of lung development, i.e. a right pulmonary artery agenesis. We ought to keep in mind these anomalies of lung development which are quite rare. Moreover in absence of pulmonary artery, the ipsilateral lung parenchyma is vascularized by systemic circulation and exposed to very high systemic pressure responsible for very severe haemoptysis requiring sometimes a pneumonectomy to be controlled. Finally we make a short review on etiology of lung haemoptysis.


Asunto(s)
Hemoptisis/etiología , Pulmón/irrigación sanguínea , Arteria Pulmonar/anomalías , Adulto , Hemoptisis/fisiopatología , Humanos , Masculino , Índice de Severidad de la Enfermedad
13.
Artículo en Inglés | MEDLINE | ID: mdl-33190792

RESUMEN

BACKGROUND: Medical personality change (MPC) is a codable diagnosis (i.e., F07.0) that deserves consideration when a patient is inexplicably no longer "acting like him/herself." Its presentation ranges from subtle to severe and is often characterized by bafflingly poor judgment and impairment in several aspects of a person's life. Despite the global impact that MPC can have on a patient's functioning, occupation, and relationships, this condition receives far less clinical consideration than better known syndromes such as depression or anxiety and is often likely incorrectly formulated as such. OBJECTIVE/METHODS: This article provides a clinically focused review of MPC. We review its clinical assessment followed by a review of its subtypes, which we have categorized to reflect the behavioral correlates of known frontotemporal-subcortical circuits. These include the apathetic type (ventromedial prefrontal cortex), the labile and disinhibited types (orbitofrontal cortex), and the aggressive and paranoid types (medial temporal lobes). RESULTS: For each of these 3 categories, we describe the clinical presentation and review management strategies. For each category, we focus on 3 common causes for MPC-traumatic brain injury, Huntington disease, and brain tumors-which we have selected because clinical features of MPC due to these conditions generalize to many other etiologies of MPC. CONCLUSIONS: MPC warrants clinical attention for the range of dysfunction and distress it can cause. It also deserves further scientific study to better characterize its phenotypes, to tailor instruments for its clinical assessment, and to identify effective treatments.


Asunto(s)
Trastornos de Ansiedad , Trastornos de la Personalidad , Humanos , Masculino , Personalidad , Trastornos de la Personalidad/diagnóstico , Corteza Prefrontal , Lóbulo Temporal
14.
J Clin Med ; 10(7)2021 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-33805916

RESUMEN

Opiophobia contributes to oligoanalgesia in the emergency department (ED), but its definition varies, and its association to healthcare providers' personality traits has been scantly explored. Our purpose was to study the different definitions of opiophobia and their association with two personality traits of doctors and nurses working in EDs, namely the stress from uncertainty and risk-taking. We used three online questionnaires: the 'Attitude Towards Morphine Use' Score (ATMS), the Stress From Uncertainty Scale (SUS) and the Risk-Taking Scale (RTS). Doctors and nurses from nine hospital EDs in francophone Switzerland were invited to participate. The ATMS score was analyzed according to demographic characteristics, SUS, and RTS. The response rate was 56%, with 57% of respondents being nurses and 63% women. Doctors, less experienced and non-indigenous participants had a significantly higher ATMS (all p ≤ 0.01). The main contributors of the ATMS were the fear of side effects and of addiction. In multivariate analysis, being a doctor, less experience and non-indigenous status were predictive of the ATMS; each point of the SUS increased the ATMS by 0.24 point. The fear of side effects and of addiction were the major contributors of opiophobia among ED healthcare providers; opiophobia was also associated with their personality traits.

15.
J Virol ; 83(11): 5495-504, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19297498

RESUMEN

Measles virus remains a substantial cause of morbidity and mortality, producing acute infection with a potential for development of viral persistence. To study the events underlying acute and persistent measles virus infection, we performed a global transcriptional analysis on murine neuroblastoma cells that were acutely or persistently infected with measles virus. In general, we found that acute infection induced significantly more gene expression changes than did persistent infection. A functional enrichment analysis to identify which host pathways were perturbed during each of these infections identified several pathways related to cholesterol biosynthesis, including cholesterol metabolic processes, hydroxymethylglutaryl-coenzyme A (CoA) reductase activity, and acetyl-CoA C-acetyltransferase activity. We also found that measles virus colocalized to lipid rafts in both acute and persistent infection models and that the majority of genes associated with cholesterol synthesis were downregulated in persistent infection relative to acute infection, suggesting a possible link with the defective viral budding in persistent infection. Further, we found that pharmacological inhibition of cholesterol synthesis resulted in the inhibition of viral budding during acute infection. In summary, persistent measles viral infection was associated with decreased cholesterol synthesis, a lower abundance of cholesterol and lipid rafts in the cell membrane, and inhibition of giant-cell formation and release of viral progeny.


Asunto(s)
Colesterol/biosíntesis , Virus del Sarampión/fisiología , Neuroblastoma/metabolismo , Neuroblastoma/virología , Enfermedad Aguda , Animales , Línea Celular Tumoral , Regulación de la Expresión Génica , Hidroximetilglutaril-CoA Reductasas/metabolismo , Microdominios de Membrana/efectos de los fármacos , Microdominios de Membrana/metabolismo , Ratones , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Mensajero/genética , Simvastatina/farmacología
16.
Oncogene ; 39(24): 4636-4649, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32398866

RESUMEN

Klotho is a transmembrane protein, which can be shed and act as a circulating hormone and is involved in regulating cellular calcium levels and inhibition of the PI3K/AKT pathway. As a longevity hormone, it protects normal cells from oxidative stress, and as a tumor suppressor it inhibits growth of cancer cells. Mechanisms governing these differential activities have not been addressed. Altered cellular metabolism is a hallmark of cancer and dysregulation of mitochondrial activity is a hallmark of aging. We hypothesized that klotho exerts its differential effects through regulation of these two hallmarks. Treatment with klotho inhibited glycolysis, reduced mitochondrial activity and membrane potential only in cancer cells. Accordingly, global metabolic screen revealed that klotho altered pivotal metabolic pathways, amongst them glycolysis and tricarboxylic acid cycle in breast cancer cells. Alteration of metabolic activity and increased AMP/ATP ratio lead to LKB1-dependent AMPK activation. Indeed, klotho induced AMPK phosphorylation; furthermore, inhibition of LKB1 partially abolished klotho's tumor suppressor activity. By diminishing deltapsi (Δψ) klotho also inhibited mitochondria Ca2+ shuttling thereby impairing mitochondria communication with SOCE leading to reduced Ca2+ influx by SOCE channels. The reduced SOCE was followed by ER Ca2+ depletion and stress. These data delineate mechanisms mediating the differential effects of klotho toward cancer versus normal cells, and indicate klotho as a potent regulator of metabolic activity.


Asunto(s)
Neoplasias de la Mama/metabolismo , Señalización del Calcio , Calcio/metabolismo , Glucuronidasa/metabolismo , Mitocondrias/metabolismo , Proteínas de Neoplasias/metabolismo , Animales , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Glucuronidasa/genética , Humanos , Proteínas Klotho , Células MCF-7 , Ratones , Mitocondrias/genética , Mitocondrias/patología , Proteínas de Neoplasias/genética
17.
J Cell Physiol ; 220(1): 222-9, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19288494

RESUMEN

Sertoli cells, lining the walls of the seminiferous tubules, are in close contact with and regulate all aspects of the development of the germ cells. Clusterin, is a glycoprotein produced abundantly by Sertoli cells, and associated with either apoptosis or cell survival. Zinc is present in high concentrations in the testis and required for sperm development by an as yet unknown mechanism. Permeation of zinc into cells via voltage-gated calcium channels (VGCCs), however, is suggested to induce cell death. We examined the possibility that Zn(2+) acts via clusterin to regulate germ cell survival. Employing an ex vivo model of mouse testis, we have assessed the role of permeation of heavy metal ions on clusterin production and secretion. Up-regulation of clusterin expression and its secretion was observed after a short exposure to zinc or to cadmium under depolarizing conditions. Expression of zinc transporter-1 (ZnT-1), previously shown to regulate Zn(2+) influx, increased following prolonged application of zinc or cadmium to the explants and prevented clusterin up-regulation by subsequent exposure to these ions. Inhibition of the MAPK and PI3K pathways reduced the up-regulation of clusterin following the intracellular rise of Zn(2+) or Cd(2+). Neutralization of secreted clusterin by an antibody or attenuation of clusterin up-regulation by inhibition of Zn(2+) permeation via the LTCC, reduced cell death in cultured seminiferous tubule cells. Taken together, our results indicate that Zn(2+) and Cd(2+) influx induce expression and secretion of clusterin, thereby linking metal homeostasis and germ cell fate.


Asunto(s)
Cadmio/farmacología , Clusterina/metabolismo , Túbulos Seminíferos/efectos de los fármacos , Zinc/farmacología , Animales , Cadmio/metabolismo , Bloqueadores de los Canales de Calcio/farmacología , Canales de Calcio Tipo L/metabolismo , Proteínas de Transporte de Catión/metabolismo , Muerte Celular/efectos de los fármacos , Permeabilidad de la Membrana Celular , Activación Enzimática , Masculino , Ratones , Quinasas de Proteína Quinasa Activadas por Mitógenos/antagonistas & inhibidores , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Inhibidores de las Quinasa Fosfoinosítidos-3 , Inhibidores de Proteínas Quinasas/farmacología , Túbulos Seminíferos/metabolismo , Túbulos Seminíferos/patología , Transducción de Señal/efectos de los fármacos , Factores de Tiempo , Técnicas de Cultivo de Tejidos , Regulación hacia Arriba , Zinc/metabolismo
18.
Carcinogenesis ; 29(9): 1692-700, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18310092

RESUMEN

Prostate Zn(2+) concentrations are among the highest in the body, and a marked decrease in the level of this ion is observed in prostate cancer. Extracellular Zn(2+) is known to regulate cell survival and proliferation in numerous tissues. In spite of this, a signaling role for extracellular Zn(2+) in prostate cancer has not been established. In the present study, we demonstrate that prostate metastatic cells are impermeable to Zn(2+), but extracellular Zn(2+) triggers a metabotropic Ca(2+) rise that is also apparent in the presence of citrate. Employing fluorescent imaging, we measured this activity in androgen-insensitive metastatic human cell lines, PC-3 and DU-145, and in mouse prostate tumor TRAMP-1 cells but not in androgen-sensitive LNCaP cells. The Ca(2+) response was inhibited by Galphaq and phospholipase C (PLC) inhibitors as well as by intracellular Ca(2+) store depletion, indicating that it is mediated by a Gq-coupled receptor that activates the inositol phosphate (IP(3)) pathway consistent with the previously identified zinc-sensing receptor (ZnR). Zn(2+)-dependent extracellular signal-regulated kinase and AKT activation, as well as enhanced Zn(2+)-dependent cell growth and survival, were observed in PC-3 cells that exhibit ZnR activity, but not in a ZnR activity-deficient PC-3 subline. Interestingly, application of Zn(2+)-citrate (Zn(2+)Cit), at physiological concentrations, was followed by a profound functional desensitization of extracellular Zn(2+)-dependent signaling and attenuation of Zn(2+)-dependent cell growth. Our results indicate that extracellular Zn(2+) and Zn(2+)Cit, by triggering or desensitizing ZnR activity, distinctly regulate prostate cancer cell growth. Thus, therapeutic strategies based either on Zn(2+) chelation or administration of Zn(2+)Cit may be effective in attenuating prostate tumor growth.


Asunto(s)
Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Neoplasias de la Próstata/patología , Receptores de Superficie Celular/metabolismo , Transducción de Señal , Compuestos de Zinc/farmacología , Animales , Calcio/metabolismo , Señalización del Calcio , Activación Enzimática , Fura-2/análogos & derivados , Fura-2/metabolismo , Humanos , Immunoblotting , Masculino , Ratones , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación , Neoplasias de la Próstata/metabolismo , Células Tumorales Cultivadas/efectos de los fármacos
19.
Carcinogenesis ; 29(8): 1546-54, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18579561

RESUMEN

Failure of current therapeutic modalities to treat melanoma remains a challenge for clinical and experimental oncology. The aggressive growth and apoptotic resistance of this tumor are mediated, in part, by aberrantly activated protein kinase B/Akt (PKB). In many cells, PKB signaling depends on integrity of cholesterol-enriched membrane microdomains (rafts). However, it is still unclear if rafts support deregulated PKB activity in melanoma. In this study, ablation of rafts in murine (B16BL6-8, JB/RH1) and human (GA) melanoma lines by cholesterol-chelating methyl-beta-cyclodextrin (MbetaCD) reduced levels of constitutively active PKB in a dose- and time-dependent manner, while reconstitution of microdomains restored PKB activity. PKB was sensitive to the membrane-permeable Ca2+ chelator 1,2-bis(o-aminophenoxy)ethane-N,N,N'N'-tetraacetic acid tetra (acetocymethyl) ester and to the calmodulin antagonist N-(6-aminohexyl)-5-chloro-1-naphtalenesulfonamide (W7) implying the contribution of Ca2+ signaling to PKB deregulation. Indeed, malignant and apoptosis-resistant clone of B16BL6 melanoma (B16BL6-8) displayed significantly higher [Ca2+](i) and store-operated Ca2+ influx (SOC) relative to non-malignant apoptosis-sensitive B16BL6 clone (Kb30) expressing barely detectable basal levels of active PKB. Raft ablation in B16BL6-8 cells robustly inhibited SOC and decreased [Ca2+](i) to levels comparable with those detected in Kb30 cells. Treating cells by PKB-inhibiting doses of M beta CD dramatically impaired their apoptotic resistance and capacity to generate tumors. Furthermore, weekly intraperitoneal injections of M beta CD to mice grafted with melanoma cells at doses of 300 and 800 mg/kg significantly attenuated tumor development. Our data implicate membrane rafts in enhancing the resistance of melanoma to apoptosis and indicate that targeting raft microdomains is a potentially effective strategy to cure this frequently fatal form of cancer.


Asunto(s)
Calcio/fisiología , Melanoma/patología , Microdominios de Membrana/fisiología , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Línea Celular Tumoral , Supervivencia Celular , Citometría de Flujo , Homeostasis , Humanos , Melanoma/mortalidad , Microdominios de Membrana/ultraestructura , Potenciales de la Membrana/fisiología , Microscopía Confocal , Membranas Mitocondriales/fisiología
20.
Swiss Med Wkly ; 138(13-14): 211-8, 2008 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-18389394

RESUMEN

QUESTION UNDER STUDY: Hospitals transferring patients retain responsibility until admission to the new health care facility. We define safe transfer conditions, based on appropriate risk assessment, and evaluate the impact of this strategy as implemented at our institution. METHODS: An algorithm defining transfer categories according to destination, equipment monitoring, and medication was developed and tested prospectively over 6 months. Conformity with algorithm criteria was assessed for every transfer and transfer category. After introduction of a transfer coordination centre with transfer nurses, the algorithm was implemented and the same survey was carried out over 1 year. RESULTS: Over the whole study period, the number of transfers increased by 40%, chiefly by ambulance from the emergency department to other hospitals and private clinics. Transfers to rehabilitation centres and nursing homes were reassigned to conventional vehicles. The percentage of patients requiring equipment during transfer, such as an intravenous line, decreased from 34% to 15%, while oxygen or i.v. drug requirement remained stable. The percentage of transfers considered below theoretical safety decreased from 6% to 4%, while 20% of transfers were considered safer than necessary. A substantial number of planned transfers could be "downgraded" by mutual agreement to a lower degree of supervision, and the system was stable on a short-term basis. CONCLUSION: A coordinated transfer system based on an algorithm determining transfer categories, developed on the basis of simple but valid medical and nursing criteria, reduced unnecessary ambulance transfers and treatment during transfer, and increased adequate supervision.


Asunto(s)
Servicio de Enfermería en Hospital , Transferencia de Pacientes/métodos , Evaluación de Programas y Proyectos de Salud , Gestión de Riesgos , Algoritmos , Humanos , Estudios Prospectivos , Medición de Riesgo , Administración de la Seguridad
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