Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 121
Filtrar
1.
Inorg Chem ; 59(14): 9951-9961, 2020 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-32614570

RESUMO

The neutral, homoleptic pyridylphosphininenickel(0) complex [Ni(2-Py-4,6-Ph2-PC5H2)2] (1) has been obtained by reaction of the formal Ni(0) source [(IPr)Ni(H2C═CHSiMe3)2] with 2 equiv of 2-(2'-pyridyl)-4,6-diphenylphosphinine (L). Compound 1 can be oxidized both electrochemically and through the use of ferrocenium salts, to afford the corresponding Ni(I) complexes [1]BF4, [1(THF)]PF6, and [12](BArF4)2. The structures of these salts reveal an interesting dependence on the nature of the anion. While [1]BF4 and [1(THF)]PF6 show trigonal-bipyramidal coordination of Ni in the solid state, [12](BArF4)2 exists as a dinuclear Ni(I) complex and possesses a bridging phosphinine moiety in a rare µ2 mode. Reactions of 1 with halobenzenes highlight the noninnocent behavior of the aromatic phosphinine ligand, leading to the formation of oxidized Ni complexes but not to classical oxidative addition products. The reaction of 1 with bromobenzene affords the λ5 phosphinine 2 and the bipyramidal Ni(I) complex [1]Br, whereas a more unconventional oxidation product 3 is formed from the reaction of 1 and iodobenzene.

2.
J Organomet Chem ; 870: 121-129, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31105336

RESUMO

This report presents the synthesis and characterization of mono- and bis(amino acid ester) ferrocene complexes generated using a sulfonamide linking strategy as an alternative to the more heavily explored amide linking strategy. These compounds were investigated to test their ability to form hydrogen bonding interactions both in the solid state and in solution, and were compared to the previously observed intramolecular interstrand crosslinking seen in amide-linked ferrocene constructs. Synthesized compounds also included controls that do not exhibit sulfonamide N-H bonds and thus cannot engage in hydrogen bonding. In the solid state, we observe both S=O⋯H-N and C=O⋯H-N intermolecular interactions, but we do not observe any intramolecular interstrand hydrogen bonding. In the solution phase, we also do not see any intramolecular hydrogen bonding interactions in these compounds as measured by titration of d6-DMSO as a competitive hydrogen bonding reagent. We also collected CD spectra on these compounds, which revealed that the chiral peptides can induce dichroism in the dd transition of the ferrocene units. Our results indicate that the peptide-ferrocene linking group governs whether intermolecular hydrogen bonding interactions can occur between the amino acids adjacent to the cyclopentadienyl groups.

3.
Phys Chem Chem Phys ; 17(4): 2349-51, 2015 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-25500795

RESUMO

The first ultrafast study of the dimeric fluorescent BF2 dye BOPHY is presented. When compared to a structurally related BODIPY dye, similar photophysical dynamics are observed, including an intermediate kinetic component present in both dye types.

4.
Pharmacopsychiatry ; 48(4-5): 145-9, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26011568

RESUMO

INTRODUCTION: Disturbances of circadian rhythms occur in all episodes of bipolar disorder (BD). Lithium, as gold-standard in the maintenance treatment of BD, is known to influence circadian processes. METHODS: In a pilot study lymphoblastoid cell lines (LCLs) were generated from 8 BD patients and 6 healthy controls. The LCLs were treated with lithiumchloride (LiCl) for 3 weeks. Cell cycles were then synchronized and expressional analysis by quantitative Real Time PCR was done. RESULTS: BD and controls differed in the period length regarding DBP (albumin D-box binding protein) expression and DBP expression was also influenced by lithium treatment. Furthermore, baseline DBP expression was significantly different between non-treated BD and healthy controls. None of the other analyzed circadian genes showed to be influenced by chronic lithium treatment or to be differentially regulated due to the diagnosis. DISCUSSION: We here show that chronic lithium treatment of LCLs leads to decreased expression of the clock gene DBP, rendering DBP a lithium-regulated gene. We could confirm the role of the circadian clock as well in lithium mode of action as in the pathomechanisms of BD although future studies with a greater number of participants and cell lines are needed.


Assuntos
Antimaníacos/farmacologia , Transtorno Bipolar/tratamento farmacológico , Relógios Circadianos , Proteínas de Ligação a DNA/biossíntese , Expressão Gênica/efeitos dos fármacos , Cloreto de Lítio/farmacologia , Fatores de Transcrição/biossíntese , Linhagem Celular , Feminino , Humanos , Masculino , Projetos Piloto
5.
Support Care Cancer ; 21(5): 1383-93, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23238655

RESUMO

PURPOSE: Compared to the literature on other malignancies, data on quality of life (QoL) in bladder cancer are sparse. This study sought answers to the following questions: In what QoL domains do patients with bladder cancer differ from the general population? Do patients with radical cystectomy differ in QoL compared to those who received conservative treatment? Do patients with neobladder generally have better QoL compared to patients with other diversion methods? METHODS: At the beginning of inpatient rehabilitation, N = 823 patients with bladder cancer were assessed. Data of a representative community sample (N = 2037) were used for comparison. The questionnaire EORTC QLQ-C30 was used to measure QoL. Multivariate linear regression models were computed to investigate differences between groups. RESULTS: Patients with both non-muscle invasive and muscle invasive bladder cancer reported significantly more problems and worse functioning than the general population. Radiotherapy is associated with clinically relevant more pain, dyspnoea, constipation, appetite loss and decreased social functioning while chemotherapy is associated more with dyspnoea. Cystectomy patients reported more fatigue, appetite loss and decreased role functioning. Male patients ≥70 years with conduit experienced more sleep and emotional problems. These effects of urinary diversion were not observed in women and younger patients. CONCLUSIONS: Patients with bladder cancer experience various QoL concerns at the beginning of inpatient rehabilitation. These problems can partly be explained by the type of treatment the patients receive. Type of urinary diversion is relevant for QoL in subgroups of patients.


Assuntos
Cistectomia/métodos , Qualidade de Vida , Neoplasias da Bexiga Urinária/patologia , Derivação Urinária/métodos , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/efeitos adversos , Antineoplásicos/uso terapêutico , Estudos Transversais , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Invasividade Neoplásica , Lesões por Radiação/epidemiologia , Fatores Sexuais , Inquéritos e Questionários , Neoplasias da Bexiga Urinária/reabilitação , Neoplasias da Bexiga Urinária/terapia , Adulto Jovem
6.
J Chem Phys ; 139(4): 044703, 2013 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-23901999

RESUMO

The interaction between zinc-tetraphenylporphyrin (ZnTPP) and fullerenes (C60 and C60F48) are studied using ultraviolet photoelectron spectroscopy (UPS) and scanning tunneling microscopy (STM). Low temperature STM reveals highly ordered ZnTPP monolayers on Au(111). In contrast to C60, a submonolayer coverage of C60F48 results in long-range disorder of the underlying single ZnTPP layer and distortion of individual ZnTPP molecules. This is induced by substantial charge transfer at the organic-organic interface, revealed by the interface energetics from UPS. However, a second layer of ZnTPP prevents C60F48 guests from breaking the self-assembled porphyrin template. This finding is important for understanding the growth behaviour of "bottom-up" functional nanostructures involving strong donor-acceptor heterojunctions in molecular electronics.

7.
Rev Med Suisse ; 9(369): 140-1, 2013 Jan 16.
Artigo em Francês | MEDLINE | ID: mdl-23409655

RESUMO

Some paediatrics centres routinely send the medical consultation letter not only to the primary or referring physician but to the patient and his/her family as well. This way of sharing medical information is appreciated not only by the patients themselves but also by a majority of physicians.


Assuntos
Documentação , Participação do Paciente , Encaminhamento e Consulta , Criança , Humanos
8.
Proc Natl Acad Sci U S A ; 106(37): 15879-84, 2009 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-19717419

RESUMO

Peptide analogues targeting various neuropeptide receptors have been used effectively in cancer therapy. A hallmark of adrenocortical tumor formation is the aberrant expression of peptide receptors relating to uncontrolled cell proliferation and hormone overproduction. Our microarray results have also demonstrated a differential expression of neuropeptide hormone receptors in tumor subtypes of human pheochromocytoma. In light of these findings, we performed a comprehensive analysis of relevant receptors in both human adrenomedullary and adrenocortical tumors and tested the antiproliferative effects of peptide analogues targeting these receptors. Specifically, we examined the receptor expression of somatostatin-type-2 receptor, growth hormone-releasing hormone (GHRH) receptor or GHRH receptor splice variant-1 (SV-1) and luteinizing hormone-releasing hormone (LHRH) receptor at the mRNA and protein levels in normal human adrenal tissues, adrenocortical and adrenomedullary tumors, and cell lines. Cytotoxic derivatives of somatostatin AN-238 and, to a lesser extent, AN-162, reduced cell numbers of uninduced and NGF-induced adrenomedullary pheochromocytoma cells and adrenocortical cancer cells. Both the splice variant of GHRH receptor SV-1 and the LHRH receptor were also expressed in adrenocortical cancer cell lines but not in the pheochromocytoma cell line. The GHRH receptor antagonist MZ-4-71 and LHRH antagonist Cetrorelix both significantly reduced cell growth in the adrenocortical cancer cell line. In conclusion, the expression of receptors for somatostatin, GHRH, and LHRH in the normal human adrenal and in adrenal tumors, combined with the growth-inhibitory effects of the antitumor peptide analogues, may make possible improved treatment approaches to adrenal tumors.


Assuntos
Neoplasias das Glândulas Suprarrenais/tratamento farmacológico , Neoplasias das Glândulas Suprarrenais/metabolismo , Neuropeptídeos/farmacologia , Receptores de Neuropeptídeos/metabolismo , 2-Hidroxifenetilamina/análogos & derivados , 2-Hidroxifenetilamina/farmacologia , Neoplasias das Glândulas Suprarrenais/genética , Neoplasias das Glândulas Suprarrenais/patologia , Glândulas Suprarrenais/metabolismo , Compostos de Anilina/farmacologia , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Citostáticos/farmacologia , Doxorrubicina/análogos & derivados , Doxorrubicina/farmacologia , Expressão Gênica , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Células PC12 , Pirróis/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Receptores LHRH/genética , Receptores LHRH/metabolismo , Receptores de Neuropeptídeos/genética , Receptores de Somatostatina/genética , Receptores de Somatostatina/metabolismo , Somatostatina/análogos & derivados , Somatostatina/farmacologia
9.
Nat Commun ; 13(1): 540, 2022 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-35087057

RESUMO

G protein-coupled receptors (GPCRs) activate G proteins and undergo a complex regulation by interaction with GPCR kinases (GRKs) and the formation of receptor-arrestin complexes. However, the impact of individual GRKs on arrestin binding is not clear. We report the creation of eleven combinatorial HEK293 knockout cell clones lacking GRK2/3/5/6, including single, double, triple and the quadruple GRK knockout. Analysis of ß-arrestin1/2 interactions for twelve GPCRs in our GRK knockout cells enables the differentiation of two main receptor subsets: GRK2/3-regulated and GRK2/3/5/6-regulated receptors. Furthermore, we identify GPCRs that interact with ß-arrestins via the overexpression of specific GRKs even in the absence of agonists. Finally, using GRK knockout cells, PKC inhibitors and ß-arrestin mutants, we present evidence for differential receptor-ß-arrestin1/2 complex configurations mediated by selective engagement of kinases. We anticipate our GRK knockout platform to facilitate the elucidation of previously unappreciated details of GRK-specific GPCR regulation and ß-arrestin complex formation.


Assuntos
Arrestina/metabolismo , Quinases de Receptores Acoplados a Proteína G/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Células HEK293 , Humanos , Fosforilação , Transdução de Sinais/fisiologia , beta-Arrestina 1/metabolismo , beta-Arrestina 2/metabolismo
10.
Ann Rheum Dis ; 70(5): 722-6, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21257615

RESUMO

OBJECTIVE: To develop recommendations to enable successful inclusion of the patient perspective in European League Against Rheumatism (EULAR)-funded scientific research projects. METHODS: The EULAR standardised operational procedures for guideline development were followed. A systematic literature review was presented during a first task force meeting, including 3 rheumatologists, 1 rheumatologist/epidemiologist, 2 allied health professionals, 2 representatives of arthritis research organisations and 7 patient representatives, resulting in 38 statements. A Delphi method was carried out to reduce and refine the statements and agree on a set of eight. Next, a survey among a wider group of experts, professionals and patient representatives (n=42), was completed. Feedback from this wider group was discussed at the second meeting and integrated in the final wording of the recommendations. Subsequently, the level of agreement of the group of experts (n=81) was re-evaluated. RESULTS: The project resulted in a definition of patient research partner and agreement on a set of eight recommendations for their involvement in research projects. These recommendations provide practical guidance for organising patient participation, capturing (1) the role of patient research partners, (2) phase of involvement, (3) the recommended number, (4) recruitment, (5) selection, (6) support, (7) training and (8) acknowledgement. CONCLUSION: Collaboration between patients and professionals in research is relatively new. Trials or effectiveness studies are not yet available. Nevertheless, it is possible to define recommendations for the inclusion of patients in research following a solid expert opinion based consensus process.


Assuntos
Pesquisa Biomédica/organização & administração , Defesa do Paciente , Europa (Continente) , Medicina Baseada em Evidências/métodos , Humanos , Defesa do Paciente/educação , Seleção de Pacientes , Guias de Prática Clínica como Assunto , Relações Profissional-Paciente
11.
Anal Bioanal Chem ; 400(3): 697-701, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21400076

RESUMO

The adsorption properties of bovine serum albumin (BSA) on pure titanium (99.99%+) were studied by time-of-flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS). For this purpose, films consisting of BSA were prepared on cleaned titanium sheets in a phosphate buffered solution under different conditions and analysed by ToF-SIMS. The dependence of the surface coverage on the concentration of the protein solution could be determined from the secondary ion mass spectrometry signals. The results agree satisfactorily with the corresponding results obtained by XPS. The observed adsorption behaviour can be fitted by the well-known formula describing a Langmuir isotherm. The Langmuir constant for pH 7 was found to be K = 174 ± 99 lg(-)1.


Assuntos
Soroalbumina Bovina/química , Titânio/química , Adsorção , Animais , Bovinos , Concentração de Íons de Hidrogênio , Espectroscopia Fotoeletrônica , Espectrometria de Massa de Íon Secundário , Propriedades de Superfície
12.
J Nanosci Nanotechnol ; 11(4): 3464-9, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21776724

RESUMO

A combined method of precipitation, phase transfer into organic solvent, solvothermal treatment and subsequent in situ polymerization was used to integrate nanocrystalline Bi2MoO6- and Bi2WO6-particles into a polymer matrix of poly-laurylacrylate. The presented method offers a new and gentle way to produce highly transparent bulk nanocomposites containing evenly distributed Bi2MoO6- and Bi2WO6-nanoparticles. Characterization results of DLS-, XRD-, REM- and TEM-measurements are presented as well as solid state UV/VIS-measurements of the particles. The transparent nanocomposites were characterized using UV/VIS-spectroscopy and ellipsometry. All composites show a good transmission in the range from 800-400 nm. The particle content of the nanocomposites was measured with TG-measurements.


Assuntos
Bismuto/química , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Nanotecnologia/métodos , Polímeros/química , Substâncias Macromoleculares/química , Teste de Materiais , Conformação Molecular , Tamanho da Partícula , Refratometria , Propriedades de Superfície
13.
Radiologe ; 51(10): 876-9, 2011 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-21845481

RESUMO

Several extensive surgical interventions of a cystic lesion in the left mandible were followed by recurrences. The lesion extended from the primary mandibular region into the area of pterygopalatine fossa finally infiltrating the orbital region and the skull base. Histological results could never demonstrate a malignancy with certainty. Due to the patient's poor general condition, the refusal for further surgical inventions and due to the malignoma-like growth pattern radiation treatment was performed. However, this had no effect on tumor progression.


Assuntos
Neoplasias Mandibulares/radioterapia , Neoplasias Mandibulares/cirurgia , Recidiva Local de Neoplasia/radioterapia , Recidiva Local de Neoplasia/cirurgia , Tumor Odontogênico Escamoso/radioterapia , Tumor Odontogênico Escamoso/cirurgia , Idoso , Fístula Cutânea/cirurgia , Progressão da Doença , Fracionamento da Dose de Radiação , Humanos , Imageamento por Ressonância Magnética , Masculino , Mandíbula/cirurgia , Neoplasias Mandibulares/patologia , Implante de Prótese Mandibular , Invasividade Neoplásica/patologia , Recidiva Local de Neoplasia/patologia , Tumor Odontogênico Escamoso/patologia , Fístula Bucal/cirurgia , Complicações Pós-Operatórias/cirurgia , Radiografia Panorâmica , Planejamento da Radioterapia Assistida por Computador , Radioterapia Adjuvante , Radioterapia Conformacional , Reoperação , Tomografia Computadorizada por Raios X
14.
Horm Metab Res ; 42(2): 88-92, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19862666

RESUMO

Endogenous cannabinoids are important signaling molecules in neuroendocrine control of homeostatic and reproductive functions including stress response and energy metabolism. The hypothalamic paraventricular and supraoptic nuclei have been shown to release endocannabinoids, which act as retrograde messengers to modulate the synaptic release of glutamate during stress response. This study endeavors to elucidate possible interaction of the endocannabinoid system with the regulation of adrenocortical function at the adrenal level. Human adrenocortical NCI-H295R cells and normal human adrenal glands were used to study the possible effects of anandamide and cannabinoid receptor 1 (CB1) antagonist SR141716A on aldosterone and cortisol secretion. Our data indicate the expression of CB1 in human adrenal cortex and adrenocortical NCI-H295R cells; CB2 was not expressed. Furthermore, anandamide inhibited basal release and stimulated release of adrenocortical steroids (corticosterone and aldosterone); this effect was reversed by CB1 antagonist (SR141716A). Therefore, the endocannabinoid system at the level of the adrenal, can directly influence adrenocortical steroidogenesis.


Assuntos
Córtex Suprarrenal/metabolismo , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/metabolismo , Córtex Suprarrenal/citologia , Córtex Suprarrenal/efeitos dos fármacos , Aldosterona/metabolismo , Ácidos Araquidônicos/farmacologia , Moduladores de Receptores de Canabinoides/farmacologia , Células Cultivadas , Endocanabinoides , Humanos , Hidrocortisona/metabolismo , Piperidinas/farmacologia , Alcamidas Poli-Insaturadas/farmacologia , Pirazóis/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptor CB1 de Canabinoide/antagonistas & inibidores , Receptor CB1 de Canabinoide/genética , Receptor CB2 de Canabinoide/antagonistas & inibidores , Receptor CB2 de Canabinoide/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rimonabanto
15.
Br J Health Psychol ; 15(Pt 3): 479-510, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19840495

RESUMO

OBJECTIVES: This qualitative study aims at understanding the consequences of body deconstruction through mastectomy on corporality and identity in women with breast cancer. DESIGN: Nineteen women were contacted through the hospital. All had to undergo mastectomy. Some were offered immediate breast reconstruction, others, because of cancer treatments, had no planned reconstruction. A qualitative reflexive methodological background was chosen. METHOD: Women were invited to participate in three semi-structured interviews, one shortly before or after mastectomy, and the other interviews later in their illness courses, after surgery. All interviews were transcribed verbatim. Thematic analysis was performed. The analysis of the first interview of each woman is presented in this article. RESULTS: Mastectomy provokes a painful experience of body deconstruction. Even when immediate reconstruction is proposed, contrasted feelings and dissonance are expressed when comparing the former healthy body to the present challenged body entity. Body transformations are accompanied with experiences of mutilation, strangeness, and modify the physical, emotional social, symbolic and relational dimensions of the woman's gendered identity. Although the opportunity of breast reconstruction is seen as a possible recovery of a lost physical symmetry and body integrity, grieving the past body and integrating a new corporality leads to a painful identity crisis. CONCLUSION: With mastectomy, the roots of the woman's identity are challenged, leading to a re-evaluation of her existential values. The consequences of mastectomy transform the woman's corporality and embodiment, and question her identity. Psychological support is discussed in the perspective of our results.


Assuntos
Imagem Corporal , Neoplasias da Mama/psicologia , Neoplasias da Mama/cirurgia , Carcinoma Ductal/psicologia , Carcinoma Ductal/cirurgia , Carcinoma Intraductal não Infiltrante/psicologia , Carcinoma Intraductal não Infiltrante/cirurgia , Carcinoma Lobular/psicologia , Carcinoma Lobular/cirurgia , Identidade de Gênero , Crise de Identidade , Mamoplastia/psicologia , Mastectomia Segmentar/psicologia , Mastectomia/psicologia , Adaptação Psicológica , Adulto , Feminino , Pesar , Humanos , Entrevista Psicológica , Pessoa de Meia-Idade , Pesquisa Qualitativa , Reoperação/psicologia
16.
Eur Neuropsychopharmacol ; 36: 154-159, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32522387

RESUMO

A polymorphism in the gene encoding the serotonin (5-HT) transporter (5-HTT) has been shown to moderate the response to CO2 inhalation, an experimental model for panic attacks (PAs). Recurrent, unpredictable PAs represent, together with anticipatory anxiety of recurring attacks, the core feature of panic disorder (PD) and significantly interfere with patients' daily life. In addition to genetic components, accumulating evidence suggests that epigenetic mechanisms, which regulate gene expression by modifying chromatin structure, also play a fundamental role in the etiology of mental disorders. However, in PD, epigenetic mechanisms have barely been examined to date. In the present study, we investigated the relationship between methylation at the regulatory region of the gene encoding the 5-HTT and the reactivity to a 35% CO2 inhalation in PD patients. We focused on four specific CpG sites and found a significant association between the methylation level of one of these CpG sites and the fear response. This suggests that the emotional response to CO2 inhalation might be moderated by an epigenetic mechanism, and underlines the implication of the 5-HT system in PAs. Future studies are needed to further investigate epigenetic alterations in PD and their functional consequences. These insights can increase our understanding of the underlying pathophysiology and support the development of new treatment strategies.


Assuntos
Dióxido de Carbono/efeitos adversos , Metilação de DNA/fisiologia , Medo/fisiologia , Transtorno de Pânico/metabolismo , Sequências Reguladoras de Ácido Nucleico/fisiologia , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Adulto , Sequência de Bases , Epigênese Genética/efeitos dos fármacos , Epigênese Genética/fisiologia , Medo/efeitos dos fármacos , Medo/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtorno de Pânico/genética , Transtorno de Pânico/psicologia , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética
17.
Neuroimmunomodulation ; 15(1): 54-60, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18667800

RESUMO

The body's ability to keep a steady homeostatic state is crucial to health and life. This involves providing an adequate response to a variety of challenges both physical and mental, such as microbial invasion and emotional distress. Interplay between the neuroendocrine and immune systems is essential in either case. Studies have demonstrated that toll-like receptors, or TLRs, play a regulatory role in both systems, and have been proposed as a possible link between the immune, hormonal and metabolic systems. As part of the innate immune system, these receptors control the identification by the body of microbial invaders and its immediate reaction in immune and inflammatory response. What are referred to as pattern recognition receptors are mostly expressed by cells involved in hematopoietic linkage, but an increasing number of studies have demonstrated their expression in other cell types such as neurons and endocrine cells on the hypothalamic-pituitary-adrenal (HPA) axis, thyrocytes, adipocytes and islets of Langerhans. Together with endocrine and metabolic dysregulation, immune system overreaction is often associated with infection and autoimmunity, clearly indicating TLR involvement at organ level which affects organ function. Several diseases such as autoimmune thyroid and pancreatic diseases, septic dysregulation of the HPA axis, diabetes and the metabolic syndrome have been linked to TLR activation and polymorphism. To gain insight into stress response and adaptation, we need to know more about TLRs and the specific physiological role they play in the endocrine and metabolic system and its processes.


Assuntos
Doenças Autoimunes/imunologia , Diabetes Mellitus/imunologia , Doenças do Sistema Endócrino/imunologia , Sistemas Neurossecretores/imunologia , Receptores Toll-Like/imunologia , Animais , Doenças Autoimunes/fisiopatologia , Diabetes Mellitus/fisiopatologia , Doenças do Sistema Endócrino/fisiopatologia , Humanos , Sistema Hipotálamo-Hipofisário/imunologia , Sistema Hipotálamo-Hipofisário/fisiopatologia , Síndrome Metabólica/imunologia , Síndrome Metabólica/fisiopatologia , Sistemas Neurossecretores/fisiopatologia
18.
J Neurosci Methods ; 164(1): 93-106, 2007 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-17540452

RESUMO

We report on the system integration of a CMOS chip that is capable of bidirectionally communicating (stimulation and recording) with electrogenic cells such as neurons or cardiomyocytes and that is targeted at investigating electrical signal propagation within cellular networks in vitro. The overall system consists of three major subunits: first, the core component is a 6.5 mm x 6.5 mm CMOS chip, on top of which the cells are cultured. It features 128 bidirectional electrodes, each equipped with dedicated analog filters and amplification stages and a stimulation buffer. The electrodes are sampled at 20 kHz with 8-bit resolution. The measured input-referred circuitry noise is 5.9 microV root mean square (10 Hz to 100 kHz), which allows to reliably detect the cell signals ranging from 1 mVpp down to 40 microVpp. Additionally, temperature sensors, a digital-to-analog converter for stimulation, and a digital interface for data transmission are integrated. Second, there is a reconfigurable logic device, which provides chip control, event detection, data buffering and an USB interface, capable of processing the 2.56 million samples per second. The third element includes software that is running on a standard PC performing data capturing, processing, and visualization. Experiments involving the stimulation of neurons with two different spatio-temporal patterns and the recording of the triggered spiking activity have been carried out. The response patterns have been successfully classified (83% correct) with respect to the different stimulation patterns. The advantages over current microelectrode arrays, as has been demonstrated in the experiments, include the capability to stimulate (voltage stimulation, 8 bit, 60 kHz) spatio-temporal patterns on arbitrary sets of electrodes and the fast stimulation reset mechanism that allows to record neuronal signals on a stimulating electrode 5 ms after stimulation (instantaneously on all other electrodes). Other advantages of the overall system include the small number of needed electrical connections due to the digital interface and the short latency time that allows to initiate a stimulation less than 2 ms after the detection of an action potential in closed-loop configurations.


Assuntos
Eletrônica Médica/instrumentação , Eletrofisiologia/instrumentação , Rede Nervosa/fisiologia , Neurônios/fisiologia , Neurofisiologia/instrumentação , Potenciais de Ação/fisiologia , Animais , Animais Recém-Nascidos , Técnicas de Cultura de Células/métodos , Células Cultivadas , Eletrônica Médica/métodos , Eletrofisiologia/métodos , Microeletrodos/normas , Microeletrodos/tendências , Rede Nervosa/citologia , Neurônios/citologia , Neurofisiologia/métodos , Ratos , Ratos Sprague-Dawley , Tempo de Reação/fisiologia , Processamento de Sinais Assistido por Computador/instrumentação , Software
19.
Biosens Bioelectron ; 22(11): 2546-53, 2007 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-17097869

RESUMO

A high degree of connectivity and the coordinated electrical activity of neural cells or networks are believed to be the reason that the brain is capable of highly sophisticated information processing. Likewise, the effectiveness of an animal heart largely depends on such coordinated cell activity. To advance our understanding of these complex biological systems, high spatiotemporal-resolution techniques to monitor the cell electrical activity and an ideally seamless interaction between cells and recording devices are desired. Here we present a monolithic microsystem in complementary metal oxide semiconductor (CMOS) technology that provides bidirectional communication (stimulation and recording) between standard electronics technology and cultured electrogenic cells. The microchip can be directly used as a substrate for cell culturing, it features circuitry units per electrode for stimulation and immediate cell signal treatment, and it provides on-chip signal transformation as well as a digital interface so that a very fast, almost real-time interaction (2 ms loop time from event recognition to, e.g., a defined stimulation) is possible at remarkable signal quality. The corresponding spontaneous and stimulated electrical activity recordings with neuronal and cardiac cell cultures will be presented. The system can be used to, e.g., study the development of neural networks, reveal the effects of neuronal plasticity and study cellular or network activity in response to pharmacological treatments.


Assuntos
Potenciais de Ação/fisiologia , Amplificadores Eletrônicos , Estimulação Elétrica/instrumentação , Microeletrodos , Miócitos Cardíacos/fisiologia , Neurônios/fisiologia , Técnicas de Patch-Clamp/instrumentação , Animais , Células Cultivadas , Galinhas , Estimulação Elétrica/métodos , Desenho de Equipamento , Análise de Falha de Equipamento , Miniaturização , Ratos , Transistores Eletrônicos
20.
Neuroscience ; 143(1): 1-6, 2006 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-17027171

RESUMO

6-Hydroxydopamine (6-OHDA), a neurotoxic substrate of the dopamine transporter (DAT), is widely used in Parkinson's disease models. However, the molecular mechanisms underlying 6-OHDA's selectivity for dopamine neurons and the injurious sequelae that it triggers are not well understood. We tested whether ectopic expression of DAT induces sensitivity to 6-OHDA in non-dopaminergic rat cortical neurons and evaluated the contribution of voltage-dependent potassium channel (Kv)-dependent apoptosis to the toxicity of this compound in rat cortical and midbrain dopamine neurons. Cortical neurons expressing DAT accumulated dopamine and were highly vulnerable to 6-OHDA. Pharmacological inhibition of DAT completely blocked this toxicity. We also observed a p38-dependent Kv current surge in DAT-expressing cortical neurons exposed to 6-OHDA, and p38 antagonists and Kv channel blockers were neuroprotective in this model. Thus, DAT-mediated uptake of 6-OHDA recruited the oxidant-induced Kv channel dependent cell death pathway present in cortical neurons. Finally, we report that 6-OHDA also increased Kv currents in cultured midbrain dopamine neurons and this toxicity was blocked with Kv channel antagonists. We conclude that native DAT expression accounts for the dopamine neuron specific toxicity of 6-OHDA. Following uptake, 6-OHDA triggers the oxidant-associated Kv channel-dependent cell death pathway that is conserved in non-dopaminergic cortical neurons and midbrain dopamine neurons.


Assuntos
Adrenérgicos/farmacologia , Proteínas da Membrana Plasmática de Transporte de Dopamina/fisiologia , Neurônios/efeitos dos fármacos , Oxidopamina/farmacologia , Canais de Potássio de Abertura Dependente da Tensão da Membrana/fisiologia , Análise de Variância , Animais , Apoptose/efeitos dos fármacos , Células Cultivadas , Córtex Cerebral/citologia , Dopamina/metabolismo , Relação Dose-Resposta a Droga , Interações Medicamentosas , Estimulação Elétrica/métodos , Embrião de Mamíferos , Proteínas de Fluorescência Verde/metabolismo , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Potenciais da Membrana/efeitos da radiação , Neurônios/fisiologia , Técnicas de Patch-Clamp/métodos , Bloqueadores dos Canais de Potássio/farmacologia , Ratos , Tetraetilamônio/farmacologia , Transfecção/métodos
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa