Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 127
Filtrar
1.
Transl Psychiatry ; 14(1): 298, 2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-39030169

RESUMEN

Excessive alcohol consumption remains a global public health crisis, with millions suffering from alcohol use disorder (AUD, or simply "alcoholism"), leading to significantly reduced life expectancy. This review examines the interplay between habitual and goal-directed behaviors and the associated neurobiological changes induced by chronic alcohol exposure. Contrary to a strict habit-goal dichotomy, our meta-analysis of the published animal experiments combined with a review of human studies reveals a nuanced transition between these behavioral control systems, emphasizing the need for refined terminology to capture the probabilistic nature of decision biases in individuals with a history of chronic alcohol exposure. Furthermore, we distinguish habitual responding from compulsivity, viewing them as separate entities with diverse roles throughout the stages of the addiction cycle. By addressing species-specific differences and translational challenges in habit research, we provide insights to enhance future investigations and inform strategies for combatting AUD.


Asunto(s)
Alcoholismo , Objetivos , Hábitos , Humanos , Alcoholismo/psicología , Animales , Conducta Adictiva/psicología , Consumo de Bebidas Alcohólicas/psicología
2.
Transl Psychiatry ; 8(1): 250, 2018 11 19.
Artículo en Inglés | MEDLINE | ID: mdl-30455463

RESUMEN

The Article was originally published under a CC BY-NC-ND 4.0 license, but has now been made available under a CC BY 4.0 license. The PDF and HTML versions of the Article have been modified accordingly.

3.
Psychopharmacology (Berl) ; 235(6): 1821-1833, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29700576

RESUMEN

RATIONALE: The corticotropin-releasing hormone (CRH) system is a key mediator of stress-induced responses in alcohol-seeking behavior. Recent research has identified the central nucleus of the amygdala (CeA), a brain region involved in the regulation of fear and stress-induced responses that is especially rich in CRH-positive neurons, as a key player in mediating excessive alcohol seeking. However, detailed characterization of the specific influences that local neuronal populations exert in mediating alcohol responses is hampered by current limitations in pharmacological and immunohistochemical tools for targeting CRH receptor subtype 1 (CRHR1). OBJECTIVE: In this study, we investigated the effect of cell- and region-specific overexpression of CRHR1 in the CeA using a novel transgenic tool. METHODS: Co-expression of CRHR1 in calcium-calmodulin-dependent kinase II (αCaMKII) neurons of the amygdala was demonstrated by double immunohistochemistry using a Crhr1-GFP reporter mouse line. A Cre-inducible Crhr1-expressing adeno-associated virus (AAV) was site-specifically injected into the CeA of αCaMKII-CreERT2 transgenic rats to analyze the role of CRHR1 in αCaMKII neurons on alcohol self-administration and reinstatement behavior. RESULTS: Forty-eight percent of CRHR1-containing cells showed co-expression of αCaMKII in the CeA. AAV-mediated gene transfer in αCaMKII neurons induced a 24-fold increase of Crhr1 mRNA in the CeA which had no effect on locomotor activity, alcohol self-administration, or cue-induced reinstatement. However, rats overexpressing Crhr1 in the CeA increased responding in the stress-induced reinstatement task with yohimbine serving as a pharmacological stressor. CONCLUSION: We demonstrate that CRHR1 overexpression in CeA-αCaMKII neurons is sufficient to mediate increased vulnerability to stress-triggered relapse into alcohol seeking.


Asunto(s)
Consumo de Bebidas Alcohólicas/metabolismo , Núcleo Amigdalino Central/metabolismo , Comportamiento de Búsqueda de Drogas/fisiología , Etanol/administración & dosificación , Neuronas/metabolismo , Receptores de Hormona Liberadora de Corticotropina/biosíntesis , Consumo de Bebidas Alcohólicas/genética , Animales , Núcleo Amigdalino Central/efectos de los fármacos , Comportamiento de Búsqueda de Drogas/efectos de los fármacos , Expresión Génica , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Transgénicos , Neuronas/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Ratas Transgénicas , Receptores de Hormona Liberadora de Corticotropina/genética , Autoadministración
4.
Eur J Cancer Care (Engl) ; 27(2): e12825, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29345023

RESUMEN

This study aimed at exploring how women from Iraq and the former Yugoslavia, diagnosed with breast cancer and living in Sweden, experience their everyday life during radiation therapy. A qualitative research design was used comprising interviews with ten women, five originating from Iraq and five from the former Yugoslavia. Striving to survive, the women experienced their everyday life during radiation therapy as extremely challenging. This experience can be placed into three categories: strategies for survival, keeping up appearances and staying in control. Because of these specific challenges, immigrant women may need additional information and guidance in conjunction with the diagnosis, which may enable them to identify possible sources of support from those closest to them. Also, greater attention should focus on acknowledging the woman behind the diagnosis, regardless of her origin, to develop an individualised support programme to help her cope with everyday life during radiation therapy.


Asunto(s)
Neoplasias de la Mama/psicología , Supervivientes de Cáncer/psicología , Acontecimientos que Cambian la Vida , Adaptación Psicológica , Adulto , Anciano , Actitud Frente a la Salud , Neoplasias de la Mama/etnología , Neoplasias de la Mama/radioterapia , Relaciones Familiares , Femenino , Humanos , Irak/etnología , Persona de Mediana Edad , Suecia/epidemiología , Revelación de la Verdad , Yugoslavia/etnología
5.
Transl Psychiatry ; 7(1): e995, 2017 01 10.
Artículo en Inglés | MEDLINE | ID: mdl-28072416

RESUMEN

Brain autopsy and biomarker studies indicate that the pathology of Alzheimer's disease (AD) is initiated at least 10-20 years before clinical symptoms. This provides a window of opportunity to initiate preventive treatment. However, this emphasizes the necessity for biomarkers that identify individuals at risk for developing AD later in life. In this cross-sectional study, originating from three epidemiologic studies in Sweden (n=1428), the objective was to examine whether amyloid pathology, as determined by low cerebrospinal fluid (CSF) concentration of the 42 amino acid form of ß-amyloid (Aß42), is associated with biomarker evidence of other pathological changes in cognitively healthy elderly. A total of 129 patients were included and CSF levels of Aß42, total tau, tau phosphorylated at threonine 181 (p-tau), neurogranin, VILIP-1, VEGF, FABP3, Aß40, neurofilament light, MBP, orexin A, BDNF and YKL-40 were measured. Among these healthy elderly, 35.6% (N=46) had CSF Aß42 levels below 530 pg ml-1. These individuals displayed significantly higher CSF concentrations of t-tau (P<0.001), p-tau (181) (P<0.001), neurogranin (P=0.009) and FABP3 (P=0.044) compared with amyloid-negative individuals. Our study indicates that there is a subpopulation among healthy older individuals who have amyloid pathology along with signs of ongoing neuronal and synaptic degeneration, as well as tangle pathology. Previous studies have demonstrated that increase in CSF tau and p-tau is a specific sign of AD progression that occurs downstream of the deposition of Aß. On the basis of this, our data suggest that these subjects are at risk for developing AD. We also confirm the association between APOE ɛ4 and amyloid pathology in healthy older individuals.


Asunto(s)
Enfermedad de Alzheimer/líquido cefalorraquídeo , Biomarcadores/líquido cefalorraquídeo , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/genética , Péptidos beta-Amiloides/líquido cefalorraquídeo , Apolipoproteína E4/genética , Factor Neurotrófico Derivado del Encéfalo/líquido cefalorraquídeo , Proteína 1 Similar a Quitinasa-3/líquido cefalorraquídeo , Estudios Transversales , Proteína 3 de Unión a Ácidos Grasos/líquido cefalorraquídeo , Femenino , Voluntarios Sanos , Humanos , Masculino , Proteína Básica de Mielina/líquido cefalorraquídeo , Neurocalcina/líquido cefalorraquídeo , Proteínas de Neurofilamentos/líquido cefalorraquídeo , Neurogranina/líquido cefalorraquídeo , Orexinas/líquido cefalorraquídeo , Fragmentos de Péptidos/líquido cefalorraquídeo , Fosfoproteínas/líquido cefalorraquídeo , Suecia , Factor A de Crecimiento Endotelial Vascular/líquido cefalorraquídeo , Proteínas tau/líquido cefalorraquídeo
6.
Tissue Cell ; 49(1): 35-44, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28011039

RESUMEN

Low back pain is a major public health issue in the Western world, one main cause is believed to be intervertebral disc (IVD) degeneration. To halt/diminish IVD degeneration, cell therapy using different biomaterials e.g. hydrogels as cell carriers has been suggested. In this study, two different hydrogels were examined (in vitro) as potential cell carriers for human mesenchymal stem cells (hMSCs) intended for IVD transplantation. The aim was to investigate cell-survival and chondrogenic differentiation of hMSCs when cultured in hydrogels Puramatrix® or Hydromatrix® and potential effects of stimulation with growth hormone (GH). hMSCs/hydrogel cultures were investigated for cell-viability, attachment, gene expression of chondrogenic markers SOX9, COL2A1, ACAN and accumulation of extracellular matrix (ECM). In both hydrogel types, hMSCs were viable for 28days, expressed integrin ß1 which indicates adhesion of hMSCs. Differentiation was observed into chondrocyte-like cells, in a higher extent in hMSCs/Hydromatrix® cultures when compared to hMSCs/Puramatrix® hydrogel cultures. Gene expression analyses of chondrogenic markers verified results. hMSCs/hydrogel cultures stimulated with GH displayed no significant effects on chondrogenesis. In conclusion, both hydrogels, especially Hydromatrix® was demonstrated as a promising cell carrier in vitro for hMSCs, when directed into chondrogenesis. This knowledge could be useful in biological approaches for regeneration of degenerated human IVDs.


Asunto(s)
Diferenciación Celular/efectos de los fármacos , Condrogénesis/efectos de los fármacos , Hidrogel de Polietilenoglicol-Dimetacrilato/administración & dosificación , Trasplante de Células Madre Mesenquimatosas , Técnicas de Cultivo de Célula , Línea Celular , Linaje de la Célula , Proliferación Celular/efectos de los fármacos , Tratamiento Basado en Trasplante de Células y Tejidos , Humanos , Degeneración del Disco Intervertebral/terapia , Células Madre Mesenquimatosas/efectos de los fármacos
7.
Eur J Oncol Nurs ; 17(3): 354-9, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23149274

RESUMEN

PURPOSE: To describe and analyze how women with breast cancer experience breathing adapted radiation therapy (BART) and to explore how women manage daily radiation therapy. METHOD: Individual interviews were conducted with 20 women treated with BART for breast cancer concerning their perception of radiation therapy. The transcribed interviews were analyzed using qualitative content analysis. RESULTS: 'The breath of life' was the overall theme, as the women experienced the breathing as a way in which to influence their treatment and thus their survival. 'Participating in one's treatment, for good or ill', was the main category with four subcategories, 'Knowing one has done something good', 'Getting an extra bonus - healthwise', 'The experience of being in control' and 'Being in a high-technology environment'. The breathing technique became the strategy by which they could manage their treatment and gave them a sense of participation which led to a feeling of being in control. The women also felt that breathing benefited their health both mentally and physically. The high-technology environment was experienced as both hopeful and frightening. CONCLUSION: Survival or increasing the chances of survival, are of ultimate importance for a woman with breast cancer. BART requires commitment from the women, which was perceived as offering them an opportunity to participate in their own treatment, for their survival. Increasing the women's possibilities to participate in their treatment benefits their health and welfare during an otherwise turbulent time and allow the rehabilitation process to start during treatment.


Asunto(s)
Neoplasias de la Mama/radioterapia , Radioterapia/métodos , Radioterapia/psicología , Respiración , Salud de la Mujer , Adaptación Psicológica , Adulto , Factores de Edad , Anciano , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/psicología , Neoplasias de la Mama/cirugía , Supervivencia sin Enfermedad , Femenino , Humanos , Entrevistas como Asunto , Acontecimientos que Cambian la Vida , Persona de Mediana Edad , Pronóstico , Investigación Cualitativa , Radioterapia Adyuvante/psicología , Factores de Riesgo , Análisis de Supervivencia , Suecia
8.
Neuroscience ; 201: 252-66, 2012 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-22100273

RESUMEN

Amygdaloid dopamine D(2) receptors play an important role in the modulation of fear/anxiety. Their topographical distribution within the amygdala is however unclear, and their role in unconditioned fear/anxiety remains largely unknown. The aim of this paper was to study the intra-amygdaloid distribution of D(2) receptors and to ascertain their role in unconditioned anxiety. Chemical anatomical studies in the rat, using D(2) and D(3)in situ hybridization, quantitative receptor autoradiography with either [(3)H]raclopride or [(125)I]sulpiride, and D(2)-like immunocytochemistry showed that the highest density of dopamine D(2) receptors is present in the central amygdaloid nucleus, particularly within its latero-capsular division, in which a D(2) but not a D(3) mRNA signal was observed. However, although at considerably reduced densities dopamine D(2) receptors were also found in other locations within the amygdala, including the basolateral nucleus. Behaviorally, the infusion of raclopride (0.75-4 µg/side) in the area of the central amygdaloid nucleus resulted at low doses in the appearance of anxiogenic-like effects in the Shock-Probe Burying test, whereas no effects of raclopride treatment were found at any dose in the Elevated Plus-Maze and the Open-Field test. Our results indicate that amygdaloid dopamine D(2)-like receptors have a topographically differentiated distribution within the rat amygdala, the major location being in the central amygdaloid nucleus. D(2)-like receptors play a role in the modulation of anxiety responses involving a potential differential function of D(2)-like receptors in the central amygdaloid nucleus versus the basolateral amygdaloid nucleus.


Asunto(s)
Amígdala del Cerebelo/metabolismo , Ansiedad/patología , Condicionamiento Psicológico/fisiología , Miedo , Regulación de la Expresión Génica/fisiología , Receptores de Dopamina D2/metabolismo , Amígdala del Cerebelo/efectos de los fármacos , Análisis de Varianza , Animales , Ansiedad/metabolismo , Autorradiografía , Antagonistas de Dopamina/farmacología , Relación Dosis-Respuesta a Droga , Electrochoque/efectos adversos , Conducta Exploratoria/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , ARN Mensajero/metabolismo , Racloprida/farmacología , Ratas , Ratas Wistar , Receptores de Dopamina D2/genética , Receptores de Dopamina D3/genética , Receptores de Dopamina D3/metabolismo
9.
Public Health ; 122(12): 1392-8, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18951593

RESUMEN

OBJECTIVES: Mental health problems are a major issue worldwide, and there is a need to further explore factors that may increase or decrease people's subjective well-being (SWB). The main aim of the present study was to extend knowledge concerning changes in cohabitation, social support or financial situation and their influence on SWB, after controlling for personality (i.e. neuroticism), in a 3-year follow-up of an adult population-based sample. The change in overall well-being was also studied during the 3- year interval. STUDY DESIGN: Longitudinal design. METHODS: A random sample of Swedish citizens, aged 20-64 years, residing in Stockholm County received a questionnaire by post, comprising items pertaining to demographics, personality, social support and SWB. All the respondents received a second questionnaire 3 years later. In total, 8324 subjects were included in the present study. RESULTS: The overall well-being of the study sample was relatively stable. Separate analyses of the three life circumstances indicated that, after controlling for personality, positive and negative changes in each sphere of life still affected SWB. CONCLUSIONS: Despite personality and the stability of SWB, these results indicate that changes in financial situation, social support and cohabitation influence SWB. It is important for society and the healthcare services to be aware that a negative change in any of these life circumstances may lead to decreased well-being for a period of at least 3 years.


Asunto(s)
Trastornos Mentales/epidemiología , Salud Mental , Adulto , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Pruebas de Personalidad , Proyectos Piloto , Pruebas Psicológicas , Psicometría , Apoyo Social , Encuestas y Cuestionarios , Suecia/epidemiología , Factores de Tiempo
10.
BMJ ; 336(7656): 1284-7, 2008 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-18503103

RESUMEN

OBJECTIVE: To examine the effectiveness of pH analysis of fetal scalp blood compared with lactate analysis in identifying hypoxia in labour to prevent acidaemia at birth. DESIGN: Randomised controlled multicentre trial. SETTING: Labour wards. PARTICIPANTS: Women with a singleton pregnancy, cephalic presentation, gestational age >or=34 weeks, and clinical indication for fetal scalp blood sampling. INTERVENTIONS: Standard pH analysis (n=1496) or lactate analysis (n=1496) with an electrochemical microvolume (5 mul) test strip device. The cut-off levels for intervention were pH <7.21 and lactate >4.8 mmol/l, respectively. MAIN OUTCOME MEASURE: Metabolic acidaemia (pH <7.05 and base deficit >12 mmol/l) or pH <7.00 in cord artery blood. RESULTS: Metabolic acidaemia occurred in 3.2% in the lactate group and in 3.6% in the pH group (relative risk 0.91, 95% confidence interval 0.61 to 1.36). pH <7.00 occurred in 1.5% in the lactate group and in 1.8% in the pH group (0.84, 0.47 to 1.50). There was no significant difference in Apgar scores <7 at 5 minutes (1.15, 0.76 to 1.75) or operative deliveries for fetal distress (1.02, 0.93 to 1.11). CONCLUSION: There were no significant differences in rate of acidaemia at birth after use of lactate analysis or pH analysis of fetal scalp blood samples to determine hypoxia during labour. TRIAL REGISTRATION: ISRCT No 1606064.


Asunto(s)
Acidosis Láctica/prevención & control , Sangre Fetal/química , Sufrimiento Fetal/prevención & control , Hipoxia Fetal/diagnóstico , Ácido Láctico/sangre , Cuero Cabelludo/irrigación sanguínea , Acidosis Láctica/congénito , Femenino , Monitoreo Fetal/métodos , Feto , Humanos , Concentración de Iones de Hidrógeno , Atención Perinatal/métodos , Embarazo
11.
FASEB J ; 22(7): 2552-60, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18367649

RESUMEN

Beta-arrestin 2 is a multifunctional key component of the G protein-coupled receptor complex and is involved in mu-opiate and dopamine D2 receptor signaling, both of which are thought to mediate the rewarding effects of ethanol consumption. We identified elevated expression of the beta-arrestin 2 gene (Arrb2) in the striatum and the hippocampus of ethanol-preferring AA rats compared to their nonpreferring counterpart ANA line. Differential mRNA expression was accompanied by different levels of Arrb2 protein. The elevated expression was associated with a 7-marker haplotype in complete linkage disequilibrium, which segregated fully between the lines, and was unique to the preferring line. Furthermore, a single, distinct, and highly significant quantitative trait locus for Arrb2 expression in hippocampus and striatum was identified at the locus of this gene, providing evidence that genetic variation may affect a cis-regulatory mechanism for expression and regional control of Arrb2. These findings were functionally validated using mice lacking Arrb2, which displayed both reduced voluntary ethanol consumption and ethanol-induced psychomotor stimulation. Our results demonstrate that beta-arrestin 2 modulates acute responses to ethanol and is an important mediator of ethanol reward.


Asunto(s)
Consumo de Bebidas Alcohólicas/genética , Consumo de Bebidas Alcohólicas/fisiopatología , Arrestinas/deficiencia , Arrestinas/genética , Recompensa , Animales , Conducta Apetitiva/fisiología , Regulación de la Expresión Génica , Hibridación in Situ , Ratones , Ratones Noqueados , ARN Mensajero/genética , Ratas , Arrestina beta 2 , beta-Arrestinas
12.
Proc Natl Acad Sci U S A ; 103(41): 15236-41, 2006 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-17015825

RESUMEN

Alcoholism is a chronic relapsing disorder with substantial heritability. Uncovering gene-environment interactions underlying this disease process can aid identification of novel treatment targets. Here, we found a lowered threshold for stress-induced reinstatement of alcohol seeking in Marchigian-Sardinian Preferring (msP) rats genetically selected for high alcohol preference. In situ hybridization for a panel of 20 stress-related genes in 16 brain regions was used to screen for differential gene expression that may underlie this behavioral phenotype. An innate up-regulation of the Crhr1 transcript, encoding the corticotropin-releasing hormone receptor 1 (CRH-R1), was found in several limbic brain areas of msP rats genetically selected for high alcohol preference, was associated with genetic polymorphism of the Crhr1 promoter, and was accompanied by increased CRH-R1 density. A selective CRH-R1 antagonist (antalarmin, 10-20 mg/kg) was devoid of effects on operant alcohol self-administration in unselected Wistar rats but significantly suppressed this behavior in the msP line. Stress-induced reinstatement of alcohol seeking was not significantly affected by antalarmin in Wistar rats but was fully blocked in msP animals. These data demonstrate that Crhr1 genotype and expression interact with environmental stress to reinstate alcohol-seeking behavior.


Asunto(s)
Alcoholismo/genética , Predisposición Genética a la Enfermedad , Variación Genética , Receptores de Hormona Liberadora de Corticotropina/genética , Estrés Fisiológico/psicología , Alcoholismo/psicología , Animales , Conducta Animal/fisiología , Genotipo , Masculino , Ratas , Ratas Mutantes , Ratas Wistar , Receptores de Hormona Liberadora de Corticotropina/biosíntesis , Receptores de Hormona Liberadora de Corticotropina/fisiología , Recurrencia , Estrés Fisiológico/genética
13.
Am J Transplant ; 6(10): 2418-28, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16925569

RESUMEN

The anti-CD20 antibody rituximab has recently gained interest as a B-cell depleting agent in renal transplantation. However, little is known about the pharmacodynamics of rituximab in renal transplant recipients. We have therefore studied the effect of single-dose rituximab in combination with conventional triple immunosuppressive therapy on the B-cell population in peripheral blood as well as in tissues. A total of 49 renal transplant recipients received single-dose rituximab, as induction therapy (n = 36) or as anti-rejection therapy (n = 13). We counted B cells in peripheral blood and performed immunohistochemical staining on lymph nodes and kidney transplant tissue samples to assess the prevalence of B cells. In all but 6 patients (88%) complete depletion of B cells in peripheral blood was achieved. In adults, 15 months after treatment the CD19+ and CD20+ cell counts were still below 5 cells/muL in the majority of patients (78%). The immunohistochemical staining showed a complete elimination of B cells in kidney tissue and a reduction of B cells in lymph nodes. In conclusion, single-dose rituximab in kidney transplant recipients evokes a long-term elimination of B cells in peripheral blood as well as within the kidney transplant. The effect seems to extend beyond the expected 3-12 months observed in lymphoma patients.


Asunto(s)
Anticuerpos Monoclonales/farmacocinética , Rechazo de Injerto/tratamiento farmacológico , Factores Inmunológicos/farmacocinética , Trasplante de Riñón/patología , Adulto , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales de Origen Murino , Antígenos CD19/inmunología , Antígenos CD20/inmunología , Linfocitos B/inmunología , Biopsia , Niño , Citometría de Flujo , Estudios de Seguimiento , Rechazo de Injerto/sangre , Rechazo de Injerto/inmunología , Humanos , Factores Inmunológicos/uso terapéutico , Trasplante de Riñón/inmunología , Ganglios Linfáticos/patología , Estudios Retrospectivos , Rituximab , Trasplante Homólogo , Resultado del Tratamiento
14.
J Chem Phys ; 124(8): 084308, 2006 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-16512717

RESUMEN

We present a fundamentally new approach for measuring the transition dipole moment of molecular transitions, which combines the benefits of quantum interference effects, such as the Autler-Townes splitting, with the familiar R-centroid approximation. This method is superior to other experimental methods for determining the absolute value of the R-dependent electronic transition dipole moment function mu(e)(R), since it requires only an accurate measurement of the coupling laser electric field amplitude and the determination of the Rabi frequency from an Autler-Townes split fluorescence spectral line. We illustrate this method by measuring the transition dipole moment matrix element for the Na2 A 1Sigma(u)+ (v' = 25, J' = 20e)-X 1Sigma(g)+ (v" = 38, J" = 21e) rovibronic transition and compare our experimental results with our ab initio calculations. We have compared the three-level (cascade) and four-level (extended Lambda) excitation schemes and found that the latter is preferable in this case for two reasons. First, this excitation scheme takes advantage of the fact that the coupling field lower level is outside the thermal population range. As a result vibrational levels with larger wave function amplitudes at the outer turning point of vibration lead to larger transition dipole moment matrix elements and Rabi frequencies than those accessible from the equilibrium internuclear distance of the thermal population distribution. Second, the coupling laser can be "tuned" to different rovibronic transitions in order to determine the internuclear distance dependence of the electronic transition dipole moment function in the region of the R-centroid of each coupling laser transition. Thus the internuclear distance dependence of the transition moment function mu(e)(R) can be determined at several very different values of the R centroid. The measured transition dipole moment matrix element for the Na2 A 1Sigma(u)+ (v' = 25, J' = 20e)-X 1Sigma(g)+ (v" = 38, J" = 21e) transition is 5.5+/-0.2 D compared to our ab initio value of 5.9 D. By using the R-centroid approximation for this transition the corresponding experimental electronic transition dipole moment is 9.72 D at Rc = 4.81 A, in good agreement with our ab initio value of 10.55 D.

15.
J Neuroendocrinol ; 18(2): 104-14, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16420279

RESUMEN

Brain-derived neurotrophic factor (BDNF) expression is strongly regulated by adrenocorticosteroids via activated gluco- and mineralocorticoid receptors. Four separate promoters are located upstream of the BDNF noncoding exons I to IV and may thus be involved in adrenocorticosteroid-mediated gene regulation. In adrenalectomised rats, corticosterone (10 mg/kg s.c.) induces a robust down-regulation of both BDNF mRNA and protein levels in the hippocampus peaking at 2-8 h. To study the role of the individual promoters in the corticosterone response, we employed exon-specific riboprobe in situ hybridisation as well as real-time polymerase chain reaction (PCR) in the dentate gyrus. We found a down-regulation, mainly of exon IV and the protein-coding exon V, in nearby all hippocampal subregions, but exon II was only down-regulated in the dentate gyrus. Exon I and exon III transcripts were not affected by corticosterone treatment. The results could be confirmed with real-time PCR in the dentate gyrus. It appears as if the exon IV promoter is the major target for corticosterone-mediated transcriptional regulation of BDNF in the hippocampus.


Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/metabolismo , Corticosterona/fisiología , Exones/fisiología , Regulación de la Expresión Génica/fisiología , Hipocampo/metabolismo , Regiones Promotoras Genéticas/fisiología , Adrenalectomía , Análisis de Varianza , Animales , Factor Neurotrófico Derivado del Encéfalo/genética , Corticosterona/sangre , Regulación hacia Abajo , Exones/genética , Masculino , ARN Mensajero/análisis , Ratas , Ratas Sprague-Dawley , Factores de Tiempo , Transcripción Genética/fisiología
17.
J Struct Biol ; 146(1-2): 227-33, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15037253

RESUMEN

BchI, belonging to the AAA+ -protein family, forms the enzyme magnesium chelatase together with BchD and BchH. This enzyme catalyses the insertion of Mg2+ into protoporphyrin IX upon ATP hydrolysis. Previous studies have indicated that BchI forms ATP-dependent complexes and it is a member of the AAA+ -protein family (ATPases associated with various cellular activities) and it was suggested based on structural homology that the BchI formed hexameric complexes. AAA+ -proteins are Mg2+ -dependent ATPases that normally form oligomeric ring complexes in the presence of ATP. Single particle analysis of fully formed ring complexes of BchI observed by negative staining EM indicate that the BchI has strong 6- and 2-fold rotational symmetries and a weaker 4-fold rotational symmetry which are reminiscent of DNA helicase. A 2D average of the fully formed BchI-ATP ring complex is presented here from images of the complex obtained from negative staining EM. Other complexes are also observed in the EM micrographs and the class averages of these are indicative of the fragility and dynamic nature of the BchI complex which has been reported and they are suggestive of partially circular complexes with six or less protomers per particle. The resolution of the average circular complex is estimated at approximately 30A and it is similar in shape and size to an atomic resolution hexameric model of BchI rendered at 30A.


Asunto(s)
Adenosina Trifosfatasas/química , Liasas/química , Dimerización , Sustancias Macromoleculares , Microscopía Electrónica , Modelos Moleculares , Estructura Cuaternaria de Proteína , Rhodobacter sphaeroides/química
18.
Cell Mol Life Sci ; 61(5): 610-617, 2004 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15004699

RESUMEN

Gene expression underlying cellular growth and differentiation is only partly understood. This study analyzed transcript levels of the formaldehyde-metabolizing enzyme alcohol dehydrogenase 3 (ADH3) and various growth and differentiation-related genes in human oral keratinocytes. Culture of confluent cells both with and without fetal bovine serum inhibited colony-forming efficiency and induced a squamous morphology. Confluency alone decreased the transcript levels of ADH3, the proliferation markers cell division cycle 2 (CDC2) and proliferating cell nuclear antigen (PCNA), and the basal cell marker cytokeratin 5 (K5), but increased transcripts for the suprabasal differentiation markers involucrin (INV) and small proline-rich protein 1B (SPR1). These changes were variably influenced by serum, i.e., loss of CDC2 and PCNA was inhibited, loss of K5 promoted, increase of SPR1 transcripts inhibited, and increase of INV promoted. The extent and onset of the effects implied that ADH3 transcription serves as a proliferation marker and that confluency with or without serum exposure can serve to selectively analyze proliferative and differentiated cellular states.


Asunto(s)
Aldehído Oxidorreductasas/genética , División Celular/fisiología , Queratinocitos/fisiología , ARN Mensajero/metabolismo , Aldehído Oxidorreductasas/biosíntesis , Northern Blotting , Humanos , Queratinocitos/citología , Boca/citología , Boca/fisiología , Reacción en Cadena de la Polimerasa
19.
J Neurosci ; 23(14): 6013-22, 2003 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-12853419

RESUMEN

The transcription of neurotrophic factors, i.e., basic fibroblast growth factor (bFGF) and brain-derived neurotrophic factor (BDNF) is regulated by glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) activation despite the lack of a classical glucocorticoid response element in their promoter region. A time course for corticosterone (10 mg/kg, s.c.) in adrenalectomized rats revealed a peak hormone effect at the 4 hr time interval for bFGF (110-204% increase), BDNF (53-67% decrease), GR (53-64% decrease), and MR (34-56% decrease) mRNA levels in all hippocampal subregions using in situ hybridization. c-fos mRNA levels were affected exclusively in the dentate gyrus after 50 min to 2 hr (38-46% decrease). Furthermore, it was evaluated whether corticosterone regulation of these genes depends on interactions with the transcription factor complex activator protein-1. c-fos antisense oligodeoxynucleotides were injected into the dorsal hippocampus of adrenalectomized rats. Corticosterone was given 2 hr later, and the effects on gene expression were measured 4 hr later. In CA1, antisense treatment significantly and selectively enhanced the hormone action on the expression of bFGF (44% enhanced increase) and BDNF (38% enhanced decrease) versus control oligodeoxynucleotide treatment. In addition, an upregulation of c-fos expression (89% increase) was found. There were no effects of c-fos antisense on hippocampal GR and MR expression. Thus it seems that a tonic c-fos mechanism exists within CA1, which reduces GR- and MR-mediated effects on expression of bFGF and BDNF.


Asunto(s)
Corticosterona/metabolismo , Hipocampo/metabolismo , Factores de Crecimiento Nervioso/metabolismo , Proteínas Proto-Oncogénicas c-fos/metabolismo , Adrenalectomía , Animales , Biomarcadores/análisis , Corticosterona/sangre , Corticosterona/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Hipocampo/efectos de los fármacos , Hibridación in Situ , Masculino , Factores de Crecimiento Nervioso/genética , Oligonucleótidos Antisentido/farmacocinética , Oligonucleótidos Antisentido/farmacología , Proteínas Proto-Oncogénicas c-fos/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-fos/genética , ARN Mensajero/metabolismo , Radioinmunoensayo , Ratas , Ratas Sprague-Dawley , Receptores de Glucocorticoides/metabolismo , Estrés Fisiológico/metabolismo , Distribución Tisular
20.
Appl Environ Microbiol ; 69(3): 1556-63, 2003 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-12620843

RESUMEN

The distribution of the concentration of potential indicators of fecal viral pollution in shellfish was analyzed under diverse conditions over 18 months in diverse geographical areas. These microorganisms have been evaluated in relation to contamination by human viral pathogens detected in parallel in the analyzed shellfish samples. Thus, significant shellfish-growing areas from diverse countries in the north and south of Europe (Greece, Spain, Sweden, and the United Kingdom) were defined and studied by analyzing different physicochemical parameters in the water and the levels of Escherichia coli, F-specific RNA bacteriophages, and phages infecting Bacteroides fragilis strain RYC2056 in the shellfish produced, before and after depuration treatments. A total of 475 shellfish samples were studied, and the results were statistically analyzed. According to statistical analysis, the presence of human viruses seems to be related to the presence of all potential indicators in the heavily contaminated areas, where E. coli would probably be suitable as a fecal indicator. The F-RNA phages, which are present in higher numbers in Northern Europe, seem to be significantly related to the presence of viral contamination in shellfish, with a very weak predictive value for hepatitis A virus, human adenovirus, and enterovirus and a stronger one for Norwalk-like virus. However, it is important to note that shellfish produced in A or clean B areas can sporadically contain human viruses even in the absence of E. coli or F-RNA phages. The data presented here will be useful in defining microbiological parameters for improving the sanitary control of shellfish consumed raw or barely cooked.


Asunto(s)
Bacteriófagos/aislamiento & purificación , Escherichia coli/aislamiento & purificación , Mariscos/virología , Virus/patogenicidad , Contaminación del Agua , Animales , Bacteroides fragilis/virología , Bivalvos/virología , Colifagos/aislamiento & purificación , Escherichia coli/virología , Grecia , Humanos , Indicadores y Reactivos , Ostreidae/virología , Fagos ARN/aislamiento & purificación , España , Suecia , Reino Unido , Virus/aislamiento & purificación
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...