Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 260
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Psychol Res ; 85(8): 3075-3083, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33331957

RESUMO

Many digitalized cognitive assessments exist to increase reliability, standardization, and objectivity. Particularly in older adults, the performance of digitized cognitive assessments can lead to poorer test results if they are unfamiliar with the computer, mouse, keyboard, or touch screen. In a cross-over design study, 40 older adults (age M = 74.4 ± 4.1 years) conducted the Trail Making Test A and B with a digital pen (digital pen tests, DPT) and a regular pencil (pencil tests, PT) to identify differences in performance. Furthermore, the tests conducted with a digital pen were analyzed manually (manual results, MR) and electronically (electronic results, ER) by an automized system algorithm to determine the possibilities of digital pen evaluation. ICC(2,k) showed a good level of agreement for TMT A (ICC(2,k) = 0.668) and TMT B (ICC(2,k) = 0.734) between PT and DPT. When comparing MR and ER, ICC(2,k) showed an excellent level of agreement in TMT A (ICC(2,k) = 0.999) and TMT B (ICC(2,k) = 0.994). The frequency of pen lifting correlates significantly with the execution time in TMT A (r = 0.372, p = 0.030) and TMT B (r = 0.567, p < 0.001). A digital pen can be used to perform the Trail Making Test, as it has been shown that there is no difference in the results due to the type of pen used. With a digital pen, the advantages of digitized testing can be used without having to accept the disadvantages.


Assuntos
Cognição , Tecnologia , Idoso , Estudos Cross-Over , Humanos , Reprodutibilidade dos Testes , Teste de Sequência Alfanumérica
2.
Osteoarthritis Cartilage ; 26(2): 264-275, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29169959

RESUMO

OBJECTIVE: The application of adjunctive mediators in Autologous chondrocyte implantation (ACI) techniques might be useful for improving the dedifferentiated chondrocyte phenotype, to support neocartilage formation and inhibit post-traumatic cartilage destruction. In this study we examined if (a) interleukin 10 treatment can cause chondrogenic phenotype stabilization and matrix preservation in mechanically injured cartilage and if (b) IL-10 can promote chondrogenesis in a clinically applied collagen scaffold for ACI treatment. MATERIALS AND METHODS: For (a) bovine articular cartilage was harvested, subjected to an axial unconfined injury and treated with bovine IL-10 (1-10,000 pg/ng/ml). For (b) a post-operatively remaining ACI graft was treated with human IL-10. Expression levels of type I/II/X collagen, SOX9 and aggrecan were measured by qPCR (a,b). After 3 weeks cell death was analyzed (nuclear blebbing and TUNEL assay) and matrix composition was determined by GAG measurements and immunohistochemistry (aggrecan, type I/II collagen, hyaluronic acid). STATISTICS: One way ANOVA analysis with Bonferroni's correction. RESULTS: (a) IL-10 stabilized the chondrogenic phenotype after injurious compression and preserved matrix integrity. This was indicated by elevated expression of chondrogenic markers COL2A1, ACAN, SOX9, while COL1A1 and COL10A1 were reduced. An increased GAG content paralleled this and histological staining of type 2 collagen, aggrecan and toluidine blue were enhanced after 3 weeks. (b) IL-10 [100 pg/ml] improved the chondrogenic differentiation of human chondrocytes, which was accompanied by cartilaginous matrix formation after 3 weeks of incubation. CONCLUSION: Interleukin-10 is a versatile adjuvant candidate to control the post-injurious environment in cartilage defects and promote chondrogenesis in ACI grafts.


Assuntos
Cartilagem Articular/lesões , Condrogênese/efeitos dos fármacos , Interleucina-10/farmacologia , Animais , Apoptose/efeitos dos fármacos , Cartilagem Articular/efeitos dos fármacos , Cartilagem Articular/metabolismo , Cartilagem Articular/patologia , Bovinos , Células Cultivadas , Condrócitos/efeitos dos fármacos , Condrócitos/patologia , Condrócitos/transplante , Colágeno/metabolismo , Matriz Extracelular/metabolismo , Glicosaminoglicanos/metabolismo , Humanos , Alicerces Teciduais
3.
BMC Musculoskelet Disord ; 18(1): 197, 2017 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-28511649

RESUMO

BACKGROUND: Joint inflammation causes meniscus degeneration and can exacerbate post-traumatic meniscus injuries by extracellular matrix degradation, cellular de-differentiation and cell death. The aim of this study was to examine whether anti-inflammatory interleukin-10 exerts protective effects in an in vitro model of TNF-α-induced meniscus degeneration. METHODS: Meniscus tissue was harvested from the knees of adult cows. After 24 h of equilibrium explants were simultaneously treated with bovine TNF-α and IL-10. After an incubation time of 72 h cell death was measured histomorphometrically (nuclear blebbing, NB) and release of glycosaminoglycans (GAG, DMMB assay) and nitric oxide (NO, Griess-reagent) were analysed. Transcription levels (mRNA) of matrix degrading enzymes, collagen type X (COL10A1) and nitric oxide synthetase 2 (NOS2) were measured by quantitative real time PCR. TNF-α-dependent formation of the aggrecanase-specific aggrecan neoepitope NITEGE was visualised by immunostaining. Differences between groups were calculated using a one-way ANOVA with a Bonferroni post hoc test. RESULTS: Administration of IL-10 significantly prevented the TNF-α-related cell death (P .001), release of NO (P .003) and NOS2 expression (P .04). Release of GAG fragments (P .001), NITEGE formation and expression of MMP3 (P .007), -13 (P .02) and ADAMTS4 (P .001) were significantly reduced. The TNF-α-dependent increase in COL10A1 expression was also antagonized by IL-10 (P .02). CONCLUSION: IL-10 prevented crucial mechanisms of meniscal degeneration induced by a key cytokine of OA, TNF-α. Administration of IL-10 might improve the biological regeneration and provide a treatment approach in degenerative meniscus injuries and in conditions of post-traumatic sports injuries.


Assuntos
Interleucina-10/uso terapêutico , Artropatias/induzido quimicamente , Artropatias/metabolismo , Articulação do Joelho/metabolismo , Meniscos Tibiais/metabolismo , Fator de Necrose Tumoral alfa/toxicidade , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Bovinos , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Mediadores da Inflamação/antagonistas & inibidores , Mediadores da Inflamação/metabolismo , Interleucina-10/farmacologia , Artropatias/tratamento farmacológico , Articulação do Joelho/efeitos dos fármacos , Articulação do Joelho/patologia , Meniscos Tibiais/efeitos dos fármacos , Meniscos Tibiais/patologia , Técnicas de Cultura de Órgãos/métodos
4.
Osteoarthritis Cartilage ; 24(11): 1981-1988, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27349464

RESUMO

OBJECTIVE: The aim of this study was to examine whether anti-inflammatory interleukin-10 (IL-10) exerts chondroprotective effects in an in vitro model of a single mechanical injury of mature articular cartilage. METHOD: Articular cartilage was harvested from the femoro-patellar groove of adult cows (Bos taurus) and cultured w/o bovine IL-10. After 24 h of equilibration explants were subjected to an axial unconfined compression (50% strain, velocity 2 mm/s, held for 10 s). After 96 h cell death was measured histomorphometrically (nuclear blebbing, NB) and the release of glycosaminoglycans (GAG, DMMB assay) and nitric oxide (NO, Griess-reagent) were analyzed. mRNA levels of matrix degrading enzymes and nitric oxide synthetase were measured by quantitative real time PCR. Differences between groups were calculated using a one-way ANOVA with a Bonferroni post hoc test. RESULTS: Injurious compression significantly increased the number of cells with NB, release of GAG and nitric oxide and expression of MMP-3, -13, ADAMTS-4 and NOS2. Administration of IL-10 significantly reduced the injury related cell death and release of GAG and NO, respectively. Expression of MMP-3, -13, ADAMTS-4 and NOS2 were significantly reduced. CONCLUSION: Joint injury is a complex process involving specific mechanical effects on cartilage as well as induction of an inflammatory environment. IL-10 prevented crucial mechanisms of chondrodegeneration induced by an injurious single compression. IL-10 might be a multipurpose drug candidate for the treatment of cartilage-related sports injuries or osteoarthritis (OA).


Assuntos
Apoptose , Cartilagem Articular , Animais , Bovinos , Matriz Extracelular , Interleucina-10 , Estresse Mecânico
5.
Lett Appl Microbiol ; 60(6): 524-30, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25706803

RESUMO

Several food samples were spiked with fungal conidia to test the efficiency of different cell disruption methods and DNA extraction kits for subsequent molecular detection. For disrupting the firm cell walls of the spores, two different pretreatment methods, namely sonication and bead beating, were tested against no pretreatment. The subsequent DNA extraction and purification was performed using three different DNA extraction methods, which are based on a diverse combination of extraction principles, such as precipitation, thermic-enzymatic lysis, pH-enhancement and bonding with a silica membrane. The aim of the study was to find out the suitable pretreatment and DNA extraction method for the recovery of detectable amounts of fungal DNA from different food matrices. Significance and impact of the study: The choice of 'ready-to-use' commercial kits and methods has been of great importance regarding the recovery of extracted DNA. However, these commercially available kits are neither effective nor time-efficient when extracting DNA from fungal spores embedded in complex food matrices. Different extraction principles were compared and their effectiveness tested using real-time PCR. The combination of different principles for the extraction and purification of DNA was found as the most efficient method (quantity and purity) to obtain DNA from moulds and their spores from food samples.


Assuntos
DNA Fúngico/genética , Microbiologia de Alimentos/métodos , Fungos/genética , Micotoxinas/metabolismo , DNA Fúngico/isolamento & purificação , Humanos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Esporos Fúngicos/química
6.
Pharmacol Ther ; 121(1): 20-8, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19000920

RESUMO

Decades of research have established that the biological functions of thyrotropin-releasing hormone (TRH) extend far beyond its role as a regulator of the hypothalamic-pituitary-thyroid axis. Gary et al. [Gary, K.A., Sevarino, K.A., Yarbrough, G.G., Prange, A.J. Jr., Winokur, A. (2003). The thyrotropin-releasing hormone (TRH) hypothesis of homeostatic regulation: implications for TRH-based therapeutics. J Pharmacol Exp Ther 305(2):410-416.] and Yarbrough et al. [Yarbrough, G.G., Kamath, J., Winokur, A., Prange, A.J. Jr. (2007). Thyrotropin-releasing hormone (TRH) in the neuroaxis: therapeutic effects reflect physiological functions and molecular actions. Med Hypotheses 69(6):1249-1256.] provided a functional framework, predicated on its global homeostatic influences, to conceptualize the numerous interactions of TRH with the central nervous system (CNS) and endocrine system. Herein, we profer a similar analysis to interactions of TRH with the immune system. Autocrine/paracrine cellular signaling motifs of TRH and TRH receptors are expressed in several tissues and organs of the immune system. Consistent with this functional distribution, in vitro and in vivo evidence suggests a critical role for TRH during the developmental stages of the immune system as well as its numerous interactions with the fully developed immune system. Considerable evidence supports a pivotal role for TRH in the pathophysiology of the inflammatory process with specific relevance to the "cytokine-induced sickness behavior" paradigm. These findings, combined with a number of documented clinical actions of TRH strongly support a potential utility of TRH-based therapeutics in select inflammatory disorders. Similar to its global role in behavioral and energy homeostasis a homeostatic role for TRH in its interactions with the immune system is consonant with the large body of available data. Recent advances in the field of immunology provide a significant opportunity for investigation of the TRH-immune system homeostatic hypothesis. Moreover, this hypothesis may provide a foundation for the development of TRH-based therapeutics for certain medical and psychiatric disorders involving immune dysfunction.


Assuntos
Fenômenos do Sistema Imunitário/fisiologia , Inflamação , Modelos Imunológicos , Hormônio Liberador de Tireotropina/fisiologia , Animais , Sistema Nervoso Central/metabolismo , Descoberta de Drogas , Homeostase , Humanos , Fenômenos do Sistema Imunitário/efeitos dos fármacos , Inflamação/tratamento farmacológico , Neuroimunomodulação/fisiologia , Receptores do Hormônio Liberador da Tireotropina/metabolismo , Hormônio Liberador de Tireotropina/metabolismo , Hormônio Liberador de Tireotropina/farmacologia
7.
Science ; 216(4546): 648-50, 1982 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-7071605

RESUMO

Intracerebroventricular administration of oxytocin to virgin female rats that had been ovariectomized and primed with estrogen 48 hours previously induced a rapid onset of full maternal behavior. The maternal behavior persisted and its incidence was dose-related. Tocinoic acid, the ring structure of oxytocin, also rapidly induced the onset of persistent, full maternal behavior. Arginine vasopressin induced persistent maternal behavior, but this behavior had a later onset. Prostaglandin F2 alpha induced strong partial maternal behavior, which showed early onset but did not persist. Many other peptides, ovarian steroids, and prostaglandin E2 were no more effective than saline. These findings suggest that the release of oxytocin and prostaglandin F2 alpha during labor may promote maternal behavior in rats.


Assuntos
Comportamento Materno , Ocitocina/farmacologia , Animais , Arginina Vasopressina/farmacologia , Encéfalo/fisiologia , Feminino , Injeções Intraventriculares , Ocitocina/administração & dosagem , Ratos , Relação Estrutura-Atividade
8.
Science ; 200(4343): 793-4, 1978 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-565535

RESUMO

Peripheral administration of the COOH-terminal octapeptide of cholecystokinin in doses from 1 to 100 micrograms per kilogram of body weight (0.25 to 25.0 micrograms per rat) significantly antagonized tail pinch-induced eating in rats, an animal model for stress-induced human hyperphagia. Centrally administered cholecystokinin was effective only in high doses (3 micrograms into the cerebral ventricle). The finding that the minimal effective dose of cholecystokinin in suppressing stress-induced appetitive behavior is smaller after peripheral than central administration suggests that the peptide is acting on peripheral, as opposed to central nervous system, substrates.


Assuntos
Colecistocinina/farmacologia , Comportamento Alimentar/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Bradicinina/farmacologia , Colecistocinina/administração & dosagem , Relação Dose-Resposta a Droga , Humanos , Masculino , Fragmentos de Peptídeos/farmacologia , Ratos , Estresse Psicológico
9.
Science ; 221(4614): 972-5, 1983 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-6136092

RESUMO

To ascertain whether Huntington's chorea and schizophrenia are associated with specific regional alterations in neurotensin, somatostatin, and thyrotropin-releasing hormone, the concentrations of these putative neurotransmitters were measured by radioimmunoassay in postmortem brain samples from patients with Huntington's chorea or schizophrenia. Compared to 50 patients without psychiatric or neurological disease, the patients with Huntington's chorea showed significantly elevated concentrations of all three neuropeptides in the nucleus caudatus. In the nucleus accumbens somatostatin levels were increased threefold, while in the amygdala thyrotropin-releasing hormone levels were elevated. In contrast, the schizophrenics exhibited reduced levels of thyrotropin-releasing hormone in two frontal cortical regions, reduced somatostatin levels in one frontal cortical area, and increased neurotensin levels in one frontal cortical area. None of the differences between the diseased brains and the controls could be accounted for by differences in age, sex, or time between death and autopsy.


Assuntos
Encéfalo/metabolismo , Doença de Huntington/metabolismo , Neurotransmissores/metabolismo , Esquizofrenia/metabolismo , Mapeamento Encefálico , Feminino , Humanos , Masculino , Neurotensina/metabolismo , Somatostatina/metabolismo , Hormônio Liberador de Tireotropina/metabolismo
10.
Science ; 178(4059): 417-8, 1972 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-4627781

RESUMO

Thyrotropin releasing hormone potentiates the behaviorial effects of dopa plus pargyline in mice. Because the potentiation occurs in hypophysectomized mice, as well as in normal mice, the phenomenon is independent of the release of thyroid stimulating hormone from the pituitary. Possible mechanisms and clinical implications are discussed.


Assuntos
Di-Hidroxifenilalanina/farmacologia , Hormônio Liberador de Tireotropina/farmacologia , Administração Oral , Animais , Comportamento Animal/efeitos dos fármacos , Di-Hidroxifenilalanina/administração & dosagem , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Hipofisectomia , Injeções Intraperitoneais , Atividade Motora/efeitos dos fármacos , Pargilina/administração & dosagem , Pargilina/farmacologia , Hormônio Liberador de Tireotropina/administração & dosagem , Fatores de Tempo
11.
J Int Med Res ; 37(4): 1152-7, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19761698

RESUMO

Fatigue in cancer patients is highly prevalent, predominantly idiopathic, difficult to manage, and has a significant negative impact on quality of life. Thyrotropin-releasing hormone (TRH) exerts normotrophic, state-dependent therapeutic effects in a variety of experimental and clinical situations. To evaluate TRH as a treatment for cancer-related fatigue, an ongoing randomized, placebo-controlled, crossover pilot study of breast cancer patients has been initiated and this report presents preliminary observations conducted with three of these patients over 4 consecutive weeks, thereby involving a total of six TRH treatments and six saline controls. Global assessment using both subjective and objective parameters showed that TRH exerted clear anti-fatigue effects in four of the six TRH treatments. These responses were rapid in onset and persisted through the 24 h observation period. No anti-fatigue responses were seen in five of the six saline controls. No unexpected side-effects were seen with TRH administration. These initial findings support the proposal that TRH can ameliorate cancer-related fatigue.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Fadiga/tratamento farmacológico , Hormônios/uso terapêutico , Hormônio Liberador de Tireotropina/uso terapêutico , Atividades Cotidianas , Ansiedade/tratamento farmacológico , Neoplasias da Mama/complicações , Neoplasias da Mama/fisiopatologia , Fadiga/etiologia , Fadiga/fisiopatologia , Feminino , Humanos , Injeções Intravenosas , Projetos Piloto , Qualidade de Vida , Inquéritos e Questionários , Resultado do Tratamento
12.
Med Trop (Mars) ; 69(6): 629-30, 2009 Dec.
Artigo em Francês | MEDLINE | ID: mdl-20099684

RESUMO

Toxoplasmosis is a worldwide parasitic zoonosis that can cause severe problems under certain circumstances. Before the advent of the last-generation anti-retroviral drugs, estimation predicted that 50% of HIV-infected patients would develop toxoplasmosis (mainly central nervous system forms). It is the first clinical manifestation of AIDS in 20% of patients. This report describes an epidemiological survey on the seroprevalence of Toxoplasma antibodies in bushmeat and pork in the Côte d'Ivoire. The purpose was to determine how the parasite circulates among wild and domestic animals and to evaluate the risk of transmission to humans after ingestion of these meats. Fifteen samples of bushmeat were purchased on markets in 6 different cities. A total of 91 single samples of fresh pork raised at three different modern breeding facilities were collected from a slaughterhouse in Abidjan. Serological testing was performed on muscle fluid using an ELISA test (Pourquier Toxoplasma kit). No bushmeat sample was positive. Global seroprevalence in pork samples was 8.8% [range, 8.2-9.37]. The seroprevalence of toxoplasmosis measured in pork samples produced at modern livestock breeding facilities was lower than values reported in samples produced by traditional breeding in Africa. This finding suggests that the use of modern techniques excluding rodents (good hygiene) can reduce animal contamination. Curing (heat and smoking) may account for the absence of Toxoplasma antibodies in bushmeat. Public information campaigns concerning the risk of consuming meat containing cysts as well as raw vegetables contaminated with oocysts are needed to prevent transmission of toxoplasmosis.


Assuntos
Anticorpos Antiprotozoários/sangue , Produtos da Carne/parasitologia , Toxoplasma/imunologia , Toxoplasmose/imunologia , Matadouros , Animais , Côte d'Ivoire/epidemiologia , Ensaio de Imunoadsorção Enzimática , Humanos , Estudos Soroepidemiológicos , Suínos/parasitologia
13.
Anal Bioanal Chem ; 390(4): 1195-202, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18172619

RESUMO

Protein extracts of photosystem II were prepared from leaf chloroplasts of different plant species by fast and nondenaturing methods. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and western blot analysis of the proteins obtained showed that the extracts were enriched by D1 proteins, which appeared putatively in association with the 33-kDa oxygen-evolving-complex subunits. In further isolation steps D1 proteins were purified using salt-gradient chromatography (fast protein liquid chromatography) and characterized by western blot and mass spectrometry.


Assuntos
Complexo de Proteína do Fotossistema II/química , Complexo de Proteína do Fotossistema II/isolamento & purificação , Western Blotting , Cromatografia em Gel , Eletroforese em Gel de Poliacrilamida , Complexo de Proteína do Fotossistema II/metabolismo , Ligação Proteica , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
14.
Med Hypotheses ; 69(6): 1249-56, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17553626

RESUMO

Nearly four decades of research have yielded thousands of publications on the physiology, pharmacology and therapeutic effects of TRH and TRH mimetic analogs. This work addresses both the neuroendocrine and the extrahypothalamic actions and functions of the tripeptide. The many reports of clinical effects of TRH in diverse medical conditions, unrelated to pituitary or thyroid function, can appear bewildering, as can its widespread involvement in a plethora of neuronal and physiological processes. Herein, we hypothesize that a logical and causal interrelationship exists between the fundamental molecular and cellular actions of TRH, its broader physiological functions and the therapeutic effects that attend the administration of exogenous TRH and TRH analogs. When viewed from this perspective, the basic neurobiological actions and functions of TRH provide a rational basis for understanding its diverse therapeutic effects. We posit: that the fundamental excitatory actions of TRH throughout the neuroaxis result from blocking various K+ channels linked to G-protein coupled TRH receptors in neurons and pituitary cells in distinct TRH-innervated anatomical pathways; that the functional consequences of blockade of these K+ channels are to enhance neuronal and secretory outputs in TRH regulatory circuits to modulate behavioral and energy homeostasis, and; that in clinical situations the resultant broad and useful therapeutic effects following administration of TRH reflect the state-dependent normalizing effects of activation of these regulatory circuits. In this light, the spectrum of reported clinical effects of TRH agonism remains unique and impressive but is less enigmatic. With the understanding that the neurobiological actions of TRH underlie and are rationally antecedent to its documented, extensive clinical 'normotrophic' effects, continued empirical efforts to assess the medical uses of TRH and related drugs seem rational and warranted. We predict that the range of disorders whose symptoms are alleviated by TRH therapy will continue to expand and that TRH agonism could conceivably become a near-universal therapeutic adjunct, particularly in the practice of neuropsychiatric medicine.


Assuntos
Neurônios/metabolismo , Neuropeptídeos/química , Hormônio Liberador de Tireotropina/fisiologia , Animais , Tronco Encefálico/metabolismo , Sistema Nervoso Central/metabolismo , Fenômenos Cronobiológicos , Homeostase , Humanos , Modelos Biológicos , Modelos Teóricos , Peptídeos/química , Receptores Acoplados a Proteínas G/metabolismo , Medula Espinal/metabolismo
15.
J Biotechnol ; 124(1): 284-301, 2006 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-16707183

RESUMO

Glycolipids are a group of compounds with a broad range of applications. Two types of glycolipids (alkylpolyglycosides and gangliosides) were examined with regard to their physicochemical properties. Despite their structural differences, they have in common that they are amphiphilic molecules and able to aggregate to form monolayers, bilayers, micelles, lyothropic mesophases or vesicles. The structures of glycolipid micelles were investigated by different experimental techniques in addition to molecular dynamic simulations. The knowledge of the physicochemical properties of gangliosides enables a better understanding of their biological functions. Structural features were obtained for the monosialogangliosides GM1, GM2 and GT1b from bovine brain by means of mass spectrometry. Further the aggregation behaviour was determined by small-angle neutron and dynamic light scattering experiments. Interaction studies of these compounds were carried out by means of surface plasmon resonance using gangliosides incorporated liposomes. They were used as model membranes that interact with the lectins WGA, RCA and HPA. The interaction of lectins immobilized to a modified silicon surface was investigated by in-situ ellipsometry.


Assuntos
Glicolipídeos/química , Glicolipídeos/metabolismo , Animais , Química Encefálica , Bovinos , Fenômenos Químicos , Físico-Química , Coloides , Simulação por Computador , Gangliosídeo G(M1)/química , Gangliosídeo G(M1)/metabolismo , Gangliosídeo G(M2)/química , Gangliosídeo G(M2)/metabolismo , Gangliosídeo G(M3)/química , Gangliosídeo G(M3)/metabolismo , Gangliosídeos/química , Gangliosídeos/metabolismo , Luz , Bicamadas Lipídicas , Lipídeos/química , Espectrometria de Massas , Modelos Químicos , Conformação Molecular , Nêutrons , Espalhamento de Radiação , Relação Estrutura-Atividade , Ressonância de Plasmônio de Superfície
16.
Biochim Biophys Acta ; 1428(2-3): 446-54, 1999 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-10434064

RESUMO

During the oxidation of sulfide and thiosulfate purple and green sulfur bacteria accumulate globules of 'elemental' sulfur. Although essential for a thorough understanding of sulfur metabolism in these organisms, the exact chemical nature of the stored sulfur is still unclear. We applied sulfur K-edge X-ray absorption near edge spectroscopy (XANES) to probe the forms of sulfur in intact cells. Comparing XANES spectra of Allochromatium vinosum, Thiocapsa roseopersicina, Marichromatium purpuratum, Halorhodospira halophila and Chlorobium vibrioforme grown photolithoautotrophically on sulfide with reference probes (fingerprint method), we found sulfur chains with the structure R-S(n)-R. Evidence for the presence of sulfur rings, polythionates and anionic polysulfides in the sulfur globules of these bacteria was not obtained.


Assuntos
Chlorobi/química , Análise Espectral/métodos , Enxofre/análise , Microanálise por Sonda Eletrônica , Glutationa/análise , Dissulfeto de Glutationa/análise
17.
Arch Gen Psychiatry ; 35(8): 999-1010, 1978 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-209758

RESUMO

Research indicates that brain peptides exert both behavioral and endocrinologic effects in humans and animals. This review summarizes the best known behavioral actions of four endogenous peptides: luteinizing hormone-releasing hormone (LHRH), adrenocorticotrophic hormone (ACTH), vasopressin, and angiotensin. The hypothalamic-releasing hormones play a role in modulating pituitary-end organ systems. Behavioral disorders may, in the future, be susceptible to formulation in terms of changes in brain peptides. Peptide research in psychiatry may be approached in several ways.


Assuntos
Hormônio Adrenocorticotrópico/fisiologia , Angiotensina II/fisiologia , Comportamento/fisiologia , Hormônio Liberador de Gonadotropina/fisiologia , Vasopressinas/fisiologia , Hormônio Adrenocorticotrópico/farmacologia , Angiotensina II/farmacologia , Animais , Comportamento/efeitos dos fármacos , Modelos Animais de Doenças , Hormônio Liberador de Gonadotropina/farmacologia , Humanos , Sistema Hipotálamo-Hipofisário/fisiologia , Hipotálamo/fisiologia , Transtornos Mentais/fisiopatologia , Hipófise/fisiologia , Projetos de Pesquisa , Glândula Tireoide/fisiologia , Vasopressinas/farmacologia
18.
Arch Gen Psychiatry ; 38(1): 106-13, 1981 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-6257196

RESUMO

Recent prospective studies suggest that thyroid state plays a role in affective disorders. A lack of thyroid hormones can lower the threshold for depression; an excess can contribute to a state of tense dysphoria. Thyroid function in some persons also appears to influence the course of affective disorders. Adequate mobilization of thyroid hormones favors recovery from depression; excess mobilization increases the risk of mania in vulnerable individuals. Although other mechanisms may be involved, evidence suggests that the modulation by thyroid hormones of the beta-adrenergic receptor response to catecholamines may contribute to these effects. Norepinephrine stimulates such receptors; thyroid hormones increase their ability to receive stimulation. The plausibility of such interactions between catecholamines and thyroid hormones occurring in the CNS is strengthened by their common origin in the amino acid tyrosine and by their synergism in many metabolic processes.


Assuntos
Catecolaminas/metabolismo , Transtornos do Humor/metabolismo , Receptores Adrenérgicos beta/metabolismo , Receptores Adrenérgicos/metabolismo , Hormônios Tireóideos/metabolismo , Monofosfato de Adenosina/metabolismo , Transtorno Bipolar/metabolismo , Transtorno Depressivo/metabolismo , Humanos , Lítio/farmacologia , Transtornos do Humor/tratamento farmacológico , Norepinefrina/metabolismo , Receptores Adrenérgicos beta/fisiologia , Tireotropina/metabolismo , Tri-Iodotironina/uso terapêutico
19.
Arch Gen Psychiatry ; 36(5): 540-7, 1979 May.
Artigo em Inglês | MEDLINE | ID: mdl-107908

RESUMO

Chronic alcoholics with secondary depression were treated with protirelin in a double-blind, placebo-controlled study. Behavioral data, collected only during the acute alcohol withdrawal state, indicated a beneficial effect of protirelin three hours after injection, but not during subsequent days. Injections caused only mild and infrequent subjective side effects and no cardiovascular effects. Endocrine data were recorded in the acute withdrawal state and after clinical remission. Findings in the acute state suggested thyroid activation and increased central dopaminergic activity, as evidenced by elevated baseline levels of growth hormone, low baseline levels of prolactin, and blunted thyroid-stimulating hormone (TSH) response to protirelin. The first two abnormalities returned to normal levels in the remission state. A blunted TSH response was observed in both the acute and the remission states. Partial persistence of this finding suggests that TSH blunting may not be solely state-dependent. In the acute withdrawal state, TSH blunting was associated with favorable behavioral responses to protirelin.


Assuntos
Alcoolismo/psicologia , Depressão/tratamento farmacológico , Hormônio Liberador de Tireotropina/uso terapêutico , Doença Aguda , Adulto , Alcoolismo/sangue , Ensaios Clínicos como Assunto , Depressão/sangue , Depressão/psicologia , Método Duplo-Cego , Avaliação de Medicamentos , Feminino , Hormônio do Crescimento/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Placebos , Prolactina/sangue , Escalas de Graduação Psiquiátrica , Testes Psicológicos , Remissão Espontânea , Síndrome de Abstinência a Substâncias/sangue , Síndrome de Abstinência a Substâncias/tratamento farmacológico , Tireotropina/sangue , Hormônio Liberador de Tireotropina/farmacologia
20.
Arch Gen Psychiatry ; 36(10): 1086-93, 1979 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-112944

RESUMO

We studied the effects of intravenous protirelin (thyrotropin-releasing hormone) in 17 schizophrenic patients and 17 normal subjects. A total of 12 patients received protirelin, 0.5 mg, and, on another occasion, niacin, 2 mg, in a double-blind, crossover design. Both behavioral and endocrine data were collected. Five patients received protirelin in an open trial; only endocrine data were collected. Protirelin caused about a 50% prompt decrease in psychotic symptoms. Patients then tended slowly to experience a relapse. Side effects were about as infrequent after protirelin as after niacin. We assayed serum prolactin (PRL), growth hormone (GH), thyroid-stimulating hormone (TSH), L-triiodothyronine (T3) and thyroxine (T4). Free T4 (FT4) index was calculated. The values for PRL, GH, and TSH at baseline and after protirelin stimulation were normal. Patients showed lower T3 values at baseline, but a brisker T3 response to protirelin, than controls. Their FT4 indices were higher at baseline. Patients showed diminished T4 binding sites rather than increased total T4. The causes of these alterations in thyroid dynamics are unidentified.


Assuntos
Hormônio do Crescimento/sangue , Prolactina/sangue , Esquizofrenia/sangue , Esquizofrenia/tratamento farmacológico , Psicologia do Esquizofrênico , Hormônios Tireóideos/sangue , Hormônio Liberador de Tireotropina/uso terapêutico , Adulto , Ensaios Clínicos como Assunto , Método Duplo-Cego , Feminino , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Comportamento Social , Tireotropina/sangue , Tiroxina/sangue , Tri-Iodotironina/sangue
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA