Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
1.
Brain Topogr ; 36(1): 52-71, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36370239

RESUMO

In migraine, the trigeminal nerve is intimately involved in the pathophysiology of the disease. We hypothesized that alterations in the sensory trigeminal activation in migraine would be reflected by EEG-derived event-related potentials (ERP). We aimed to investigate differences in the temporal and spatial processing of trigeminal stimuli between interictal migraine patients and healthy subjects. ERP to trigeminal stimuli were recorded at 128-channels to allow localization of their cortical sources with high temporal resolution. Seventeen patients with episodic migraine without aura, 17 subjects with episodic migraine with aura, and 17 healthy subjects participated in the study. The first branch of the trigeminal nerve was stimulated using intranasal chemical (CO2), cutaneous electrical, and cutaneous mechanical (air puff) stimuli. Analyses were performed with regard to micro-state segmentation, ERP source localization, and correlation with the patients' clinical characteristics. Topographical assessments of EEG configurations were associated with the pathological condition. The source analysis revealed altered trigeminal-sensory response patterns in the precuneus, temporal pole, and cerebellum for both migraine groups during the interictal phase. The estimated current source density was positively correlated with migraine disease duration, indicating brain functional and structural changes as a consequence of the disease. Hyperactivity of the cerebellar posterior lobe was observed as a specific trigeminal response of migraine patients with aura. In conclusion, our results suggest the presence of brain changes accompanying the advancement of migraine as an expression of dysfunctional central pain processing. Hence, we identified EEG patterns in response to mechano-/chemosensory stimuli that can serve as biomarkers of migraine.


Assuntos
Transtornos de Enxaqueca , Humanos , Transtornos de Enxaqueca/diagnóstico por imagem , Encéfalo , Potenciais Evocados , Face , Cerebelo
2.
Blood ; 118(10): 2712-22, 2011 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-21791434

RESUMO

Pleiotrophin (Ptn) is strongly expressed by stromal cells which maintain HSCs. However, in vivo, Ptn deficiency does not alter steady-state hematopoiesis. However, knockdown of Ptn (Ptn(KD)) in stromal cells increases production of hematopoietic progenitors as well as HSC activity in cocultures, suggesting that Ptn may have a role in HSC activation. Indeed, transplantations of wild-type (Ptn(+/+)) HSCs into Ptn(-/-) mice show increased donor cell production in serial transplantations and dominant myeloid regeneration caused by Ptn-dependent regulation of HSC repopulation behavior. This regulation of Lin(-)Kit(+)Sca1(+) function is associated with increased proliferation and, on a molecular level, with up-regulated expression of cyclin D1 (Ccnd1) and C/EBPα (Cepba), but reduced of PPARγ. The known HSC regulator ß-catenin is, however, not altered in the absence of Ptn. In conclusion, our results point to different Ptn-mediated regulatory mechanisms in normal hemostasis and in hematopoietic regeneration and in maintaining the balance of myeloid and lymphoid regeneration. Moreover, our results support the idea that microenvironmental Ptn regulates hematopoietic regeneration through ß-catenin-independent regulation of Ccnd1 and Cebpa.


Assuntos
Proteínas de Transporte/fisiologia , Proliferação de Células , Citocinas/fisiologia , Hematopoese , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/fisiologia , Células Estromais/metabolismo , Animais , Aorta/citologia , Aorta/metabolismo , Western Blotting , Proteínas Estimuladoras de Ligação a CCAAT/genética , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Células Cultivadas , Ciclina D1/genética , Ciclina D1/metabolismo , Feminino , Citometria de Fluxo , Imunofluorescência , Regulação da Expressão Gênica , Linfócitos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células Mieloides/metabolismo , RNA Mensageiro/genética , Regeneração , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Estromais/citologia , beta Catenina/genética , beta Catenina/metabolismo
3.
Data Brief ; 42: 108021, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35341031

RESUMO

Energy system modeling can be used to develop internally-consistent quantified scenarios. These provide key insights needed to mobilise finance, understand market development, infrastructure deployment and the associated role of institutions, and generally support improved policymaking. However, access to data is often a barrier to starting energy system modeling, especially in developing countries, thereby causing delays to decision making. Therefore, this article provides data that can be used to create a simple zero-order energy system model for a range of developing countries in Africa, East Asia, and South America, which can act as a starting point for further model development and scenario analysis. The data are collected entirely from publicly available and accessible sources, including the websites and databases of international organisations, journal articles, and existing modeling studies. This means that the datasets can be easily updated based on the latest available information or more detailed and accurate local data. As an example, these data were also used to calibrate a simple energy system model for Kenya using the Open Source Energy Modeling System (OSeMOSYS) and three stylized scenarios (Fossil Future, Least Cost and Net Zero by 2050) for 2020-2050. The assumptions used and the results of these scenarios are presented in the appendix as an illustrative example of what can be done with these data. This simple model can be adapted and further developed by in-country analysts and academics, providing a platform for future work.

4.
Chemosphere ; 66(11): 2210-8, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17005238

RESUMO

Taste and odour (T&O) causing compounds, in particular, 2-methylisoborneol (MIB) and geosmin, are a problem for water authorities as they are recalcitrant to conventional water treatment. In this study, biological sand filtration was shown to be an effective process for the complete removal of MIB and geosmin, with removal shown to be predominantly through biodegradation. In addition, MIB and geosmin were also effectively degraded in batch bioreactor experiments using biofilm sourced from one of the sand filters as the microbial inoculum. The biodegradation of MIB and geosmin was determined to be a pseudo-first-order reaction with rate constants ranging between 0.10 and 0.58 d(-1) in the bioreactor experiments. Rate constants were shown to be dependent upon the initial concentration of the microbial inoculum but not the initial concentration of MIB and geosmin when target concentrations of 200 and 50 ng l(-1) were used. Furthermore, rate constants were shown to increase upon re-exposure of the biofilm to both T&O compounds. Enrichment cultures with subsequent community profile analysis using 16S rRNA-directed PCR-DGGE identified four bacteria most likely involved in the biodegradation of geosmin within the sand filters and bioreactors. These included a Pseudomonas sp., Alphaproteobacterium, Sphingomonas sp. and an Acidobacteriaceae member.


Assuntos
Bactérias/metabolismo , Biofilmes , Reatores Biológicos , Canfanos/metabolismo , Naftóis/química , Poluentes Químicos da Água/metabolismo , Purificação da Água/métodos , Abastecimento de Água , Bactérias/genética , Biodegradação Ambiental , Eletroforese , Odorantes/análise , RNA Ribossômico 16S/genética , Dióxido de Silício
5.
J Orofac Orthop ; 66(5): 338-48, 2005 Sep.
Artigo em Inglês, Alemão | MEDLINE | ID: mdl-16231110

RESUMO

OBJECTIVE: The objective of this study was to describe the cephalometric characteristics of the open bite, and to classify the open bite according to individualized norms. MATERIAL AND METHOD: The lateral cephalograms of 134 patients with an anterior open bite (min -0.5 mm) were analyzed. Patients were classified according to the inclination of the jaws, applying the principles of individualized cephalometry. The harmony box described by Hasund was used to define individualized norms for the inclination of the upper and lower jaws in each patient. The open bite was classified into four sub-types: (1) dental, (2) skeletal with enlarged ML-NSL angle, (3) skeletal with reduced ML-NSL angle, and (4) skeletal with deviations in upper and lower jaws. A skeletal open bite was found in 89 patients (66.4%). A dental open bite was found in 45 patients (33.6%). RESULTS: A number of significant differences were found between these four groups using single-factor variance analysis and the Bonferroni a posteriori test, (p < or = 0.05, p < or = 0.01, p < or = 0.001). The most prominent variables were index value of anterior facial hight, total facial height ratio, gonial angle, and Y-axis. No significant differences were found for overbite, however. CONCLUSION: It was possible to use individualized norms to classify the open bite into four sub-types. The demarcation between the four groups was supported statistically. The extent of the anterior open bite does not allow any conclusions as to the craniofacial pattern.


Assuntos
Cefalometria/métodos , Mordida Aberta/classificação , Mordida Aberta/diagnóstico por imagem , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Radiografia Dentária/métodos , Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
6.
Ann N Y Acad Sci ; 1310: 32-43, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24611828

RESUMO

Hematopoietic stem cells (HSCs) are a rare population of somatic stem cells that have the ability to regenerate the entire mature blood system in a hierarchical way for the duration of an adult life. Adult HSCs reside in the bone marrow niche. Different niche cell types and molecules regulate the balance of HSC dormancy and activation as well as HSC behavior in both normal and malignant hematopoiesis. Here, we describe the interplay of HSCs and their niche, in particular the involvement of the Wnt signaling pathway. Although the prevailing notion has been that malignant transformation of HSCs is the main cause of leukemia, evidence is mounting that disruption of niche regulation by transformed hematopoietic cells, which may overexpress Wnt signaling or intrinsic stromal defects in gene expression, is at least a collaborative factor in leukemogenesis. Thus, insights into the normal and altered functions of niche components will help to obtain a better understanding of normal and malignant hematopoiesis and how environmental factors affect these processes.


Assuntos
Hematopoese/genética , Nicho de Células-Tronco/genética , Proteínas Wnt/agonistas , Proteínas Wnt/antagonistas & inibidores , Via de Sinalização Wnt , Adulto , Animais , Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Hematopoese/efeitos dos fármacos , Humanos , Leucemia/genética , Leucemia/metabolismo , Ligantes , Nicho de Células-Tronco/efeitos dos fármacos , Via de Sinalização Wnt/efeitos dos fármacos , Via de Sinalização Wnt/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA