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1.
Rev Med Liege ; 76(7-8): 608-613, 2021 Jul.
Artigo em Francês | MEDLINE | ID: mdl-34357713

RESUMO

Bickerstaff brainstem encephalitis, Miller-Fisher syndrome and Guillain-Barré syndrome are related conditions and are now considered as part of a continuous clinical spectrum. In this report, we describe the case of a 24-year-old female patient showing paraparesis rapidly evolving into flaccid tetraparesis, areflexia, ophthalmoplegia, drowsiness, cognitive impairment and memory loss leading to the diagnosis of Bickerstaff brainstem encephalitis and Guillain-Barré syndrome overlap. With this example, we emphasize the importance of interdisciplinary rehabilitation care. Indeed such a combination of peripheral and central neurological deficits requests a multimodal approach. We show that early care benefits the autonomy and the quality of life of such patients.


L'encéphalite du tronc cérébral de Bickerstaff, le syndrome de Miller-Fisher et le syndrome de Guillain-Barré sont des pathologies apparentées qui font désormais partie d'un spectre clinique continu. Nous décrivons le cas d'une patiente âgée de 24 ans présentant une paraparésie évoluant rapidement en tétraparésie flasque, une aréflexie, une ophtalmoplégie, de la somnolence, un fléchissement cognitif et des troubles mnésiques, faisant évoquer un chevauchement entre l'encéphalite du tronc cérébral de Bickerstaff et le syndrome de Guillain-Barré. Par cet exemple clinique, nous insistons sur l'importance d'une prise en charge interdisciplinaire en réadaptation. En effet, une approche multimodale est nécessaire pour aborder cette combinaison de symptômes neurologiques périphériques et centraux. Nous montrons l'intérêt que peut avoir une prise en charge précoce sur l'autonomie et la qualité de vie de tels patients.


Assuntos
Encefalite , Síndrome de Guillain-Barré , Síndrome de Miller Fisher , Adulto , Tronco Encefálico , Encefalite/complicações , Encefalite/diagnóstico , Feminino , Síndrome de Guillain-Barré/complicações , Síndrome de Guillain-Barré/diagnóstico , Humanos , Qualidade de Vida , Adulto Jovem
2.
J Labelled Comp Radiopharm ; 58(7): 281-90, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-26011311

RESUMO

An efficient, fully automated, enantioselective multi-step synthesis of no-carrier-added (nca) 6-[(18)F]fluoro-L-dopa ([(18)F]FDOPA) and 2-[(18)F]fluoro-L-tyrosine ([(18)F]FTYR) on a GE FASTlab synthesizer in conjunction with an additional high- performance liquid chromatography (HPLC) purification has been developed. A PTC (phase-transfer catalyst) strategy was used to synthesize these two important radiopharmaceuticals. According to recent chemistry improvements, automation of the whole process was implemented in a commercially available GE FASTlab module, with slight hardware modification using single use cassettes and stand-alone HPLC. [(18)F]FDOPA and [(18)F]FTYR were produced in 36.3 ± 3.0% (n = 8) and 50.5 ± 2.7% (n = 10) FASTlab radiochemical yield (decay corrected). The automated radiosynthesis on the FASTlab module requires about 52 min. Total synthesis time including HPLC purification and formulation was about 62 min. Enantiomeric excesses for these two aromatic amino acids were always >95%, and the specific activity of was >740 GBq/µmol. This automated synthesis provides high amount of [(18)F]FDOPA and [(18)F]FTYR (>37 GBq end of synthesis (EOS)). The process, fully adaptable for reliable production across multiple PET sites, could be readily implemented into a clinical good manufacturing process (GMP) environment.


Assuntos
Di-Hidroxifenilalanina/análogos & derivados , Compostos Radiofarmacêuticos/síntese química , Tirosina/análogos & derivados , Automação Laboratorial , Técnicas de Química Sintética/instrumentação , Técnicas de Química Sintética/métodos , Di-Hidroxifenilalanina/síntese química , Tirosina/síntese química
3.
Strahlenther Onkol ; 188(3): 235-42, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22318328

RESUMO

BACKGROUND: We performed a prospective phase II trial to investigate the safety and efficacy of radiotherapy combined with capecitabine in patients suffering from a recurrence of a squamous cell carcinoma of the head and neck (SCCHN) within a previously irradiated field. PATIENTS AND METHODS: A total of 31 evaluable patients with recurrent SCCHN received re-irradiation with a total dose of 50 Gy (25 fractions over 5 weeks) up to a maximum of 60 Gy combined with 900 mg/m(2)/day capecitabine given on the days of radiotherapy. RESULTS: The median time to relapse after the first course of radiotherapy was 15 months. The overall response rate in our study was 68% including 6 patients with a complete response. The median overall survival was 8.4 months. Grade 3 or 4 mucositis occurred in 4 patients and 1 patient, respectively. No grade 4 hematological toxicities were observed; 1 patient had grade 3 anemia. The cumulative median lifetime dose was 116 Gy. CONCLUSION: Capecitabine combined with re-irradiation is a well-tolerated treatment in patients with recurrent SCCHN. In light of its good tolerability, it appears to be a potential option for patients with a reduced performance status and may also serve as a basis for novel treatment concepts, such as in combination with targeted therapies.


Assuntos
Antimetabólitos Antineoplásicos/uso terapêutico , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Desoxicitidina/análogos & derivados , Fluoruracila/análogos & derivados , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/radioterapia , Adulto , Idoso , Capecitabina , Carcinoma de Células Escamosas/mortalidade , Terapia Combinada/efeitos adversos , Desoxicitidina/uso terapêutico , Feminino , Fluoruracila/uso terapêutico , Neoplasias de Cabeça e Pescoço/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Mucosite/etiologia , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/radioterapia , Radioterapia/efeitos adversos , Carcinoma de Células Escamosas de Cabeça e Pescoço , Análise de Sobrevida , Resultado do Tratamento , Adulto Jovem
4.
Heredity (Edinb) ; 106(6): 962-72, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21081968

RESUMO

Species that overlap over a large part of their range and habitat requirements are challenging for the study of speciation and hybridization. In this respect, the study of broadscale introgressive hybridization has raised recent interest. Here we studied hybridization between two closely related amphibians Lissotriton helveticus and Lissotriton vulgaris that reproduce over a wide sympatric zone. We used mitochondrial and microsatellite markers on 1272 individuals in 37 sites over Europe to detect hybrids at the individual-level and to analyse Hardy-Weinberg and linkage disequilibria at the population-level. Morphological traits showed a strong bimodal distribution. Consistently, hybrid frequency was low (1.7%). We found asymmetric introgression with five times more hybrids in L. vulgaris than in L. helveticus, a pattern probably explained by an unequal effective population size in a study part wherein L. helveticus numerically predominates. Strikingly, significant levels of introgression were detected in 73% of sites shared by both species. Our study showed that introgression is widespread but remains confined to the sites where the two species reproduce at the same time. This pattern may explain why these species remain genetically distinct over a broad sympatric zone.


Assuntos
Hibridização Genética/genética , Salamandridae/fisiologia , Animais , DNA Mitocondrial/genética , Feminino , Estudos de Associação Genética , Genética Populacional , Masculino , Repetições de Microssatélites/genética , Fenótipo , Reprodução/genética , Salamandridae/genética , Especificidade da Espécie
5.
Biochim Biophys Acta Mol Basis Dis ; 1866(6): 165722, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32057941

RESUMO

It is increasingly recognized that sex and gender differences (S&G) influence cardiovascular diseases (CVD), greatly impacting disease management. In terms of definition, sex refers to biological aspects, gender effects being mainly related to socio-cultural factors. Both sex and gender are interpenetrated in humans and difficult to separate. This is more clearly feasible in animal models where sex effects largely predominate. As alterations in energy metabolism are essential features of cardiovascular diseases, sexual dimorphism of energy metabolism and more specifically mitochondria occupies a place of choice. This review presents the basis of sex and gender differences in the cardiovascular pathophysiology, and how it mainly affects woman diseases, effectiveness of therapies and clinical outcome. These differences rely on complex molecular mechanisms that are still poorly understood because of the under-representation of females/women in experimental and clinical studies. Finally, the differing psychological and biological phases of woman's life are largely underestimated. This review presents an overview of the field with focus on differences in cardiac energy metabolism, which are illustrated with specific examples.


Assuntos
Doenças Cardiovasculares/epidemiologia , Metabolismo Energético , Coração/fisiopatologia , Doenças Cardiovasculares/fisiopatologia , Feminino , Humanos , Relações Interpessoais , Masculino , Mitocôndrias/metabolismo , Fatores de Risco , Caracteres Sexuais
6.
Mol Ecol ; 17(15): 3496-505, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19160477

RESUMO

Gene flow in riverine species is constrained by the dendritic (branching) structure of the river network. Spatial genetic structure (SGS) of freshwater insects is particularly influenced by catchment characteristics and land use in the surroundings of the river. Gene flow also depends on the life cycle of organisms. Aquatic larvae mainly drift downstream whereas flying adults can disperse actively overland and along watercourses. In-stream movements can generate isolation by distance (IBD) at a local scale and differentiation between subcatchments. However, these patterns can be disrupted by overland dispersal. We studied SGS across the Loire River in the damselfly Calopteryx splendens which is able to disperse along and between watercourses. Our sampling design allowed us to test for overland dispersal effects on genetic differentiation between watercourses. Amplified fragment length polymorphism markers revealed high genetic differentiation at the catchment scale but the genetic structure did not reflect the geographical structure of sampling sites. We observed IBD patterns when considering the distance following the watercourse but also the Euclidean distance, i.e. the shortest distance, between pairs of sites. Altogether, our results support the hypothesis of overland dispersal between watercourses. From a conservation perspective, attention should be paid to the actual pathways of gene flow across complex landscapes such as river networks.


Assuntos
Água Doce/parasitologia , Fluxo Gênico , Insetos/genética , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Animais , França , Variação Genética , Genética Populacional , Geografia
7.
Ann Endocrinol (Paris) ; 69(3): 227-30, 2008 Jun.
Artigo em Francês | MEDLINE | ID: mdl-18423556

RESUMO

UNLABELLED: The obese patients adhere weakly to rehabilitation programs; therefore the expected gains are often disappointing. This is possibly linked to the monotony of constant velocity exercises frequently proposed. Consequently, other less monotonous exercises such as the intermittent walk may be more appropriated. OBJECTIVES: The main objectives of this study were to determine if the obese women prefer a constant velocity walk or an intermittent walk, and to analyze the effects of a rehabilitation program based on the intermittent walk. MATERIALS AND METHODS: Twenty obese women were recruited. To determine the preferred walk modality, 10 obese women performed a constant velocity walk and an intermittent walk (with a similar duration and velocity) on a treadmill. The preferred walk modality was determined by lower ratings of perceived exertion. Then, these same 10 women participated in a rehabilitation program of 10 weeks (three days per week) consisting of intermittent walks. The 10 other women did not participate in a training program. RESULTS: The ratings of perceived exertion were not significantly different between the two walk modalities. However, the women who participated in a training program increased their maximal distance during a 6 min walking test and they have stabilized theirs anthropometric data. Meanwhile, the untrained women have increased their body mass, body mass index and percentage of body fat. CONCLUSION: The obese patients preferred similarly the constant velocity walk and the intermittent walk, and a rehabilitation program based on an intermittent walk is effective in avoiding the obesity aggravation.


Assuntos
Composição Corporal , Índice de Massa Corporal , Obesidade/reabilitação , Caminhada , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Obesidade/psicologia , Percepção , Esforço Físico
8.
Mol Cell Biol ; 7(7): 2558-67, 1987 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-3039350

RESUMO

We have identified in and around the immunoglobulin heavy-chain enhancer two apparently distinct negative regulatory elements which repress immunoglobulin H enhancer, simian virus 40 enhancer, and heterologous promoter activity in fibroblasts but not in myeloma cells. We propose that in nonlymphoid cells, negative regulatory elements prevent activation of the immunoglobulin H enhancer by ubiquitous stimulatory trans-acting factors.


Assuntos
Elementos Facilitadores Genéticos , Genes Reguladores , Cadeias Pesadas de Imunoglobulinas/genética , Animais , DNA/genética , Regulação da Expressão Gênica , Globinas/genética , Camundongos , Regiões Promotoras Genéticas , Vírus 40 dos Símios/genética , Transcrição Gênica
9.
Aust Vet J ; 85(4): 141-7, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17397384

RESUMO

OBJECTIVE: To evaluate the effectiveness of a reproductive management program consisting of combinations of Ovsynch/TAI and prostaglandin (PG) F(2alpha) treatments in Holstein dairy cows under a pasture-based dairying system. DESIGN: Field trial. PROCEDURE: A total of 1177 cows in 8 commercial dairy farms were randomly allocated to control and treatment groups. Treatment group cows received one of two interventions depending upon the number of days postpartum (DPP) before the planned start of breeding. Cows more than 50 DPP by the planned start of breeding received the Ovsynch/TAI treatment, consisting of gonadotrophin releasing hormone (GnRH) - PGF(2alpha)- GnRH plus timed artificial insemination. Cows between 40 and 50 DPP received a PGF(2alpha) treatment followed by oestrus detection and, if the cow was not seen in oestrus, the cow received a second PGF(2alpha) 14 days later. Control cows were submitted to twice a day heat detection followed by artificial insemination. The experimental period was the start of the breeding season plus 21 days for cows over 50 DPP at the start of breeding, and was 40-61 DPP for cows that calved later and passed their voluntary waiting period after the start of the breeding season. RESULTS: Submission rate was higher for the treated group than for the control group (84.9% vs. 55.1%; P < 0.0001), as was the conception rate (51.0% vs. 46.1%; P < 0.03). Due to farm variations, pregnancy rate was similar in both groups (38.5% vs. 28.2%; P > 0.1). Within the treated group, conception rate and pregnancy rate of the cows inseminated after a PGF(2alpha) were higher than for timed artificial inseminated cows (51.4% vs. 32.6%; P < 0.001), and (37.8% vs. 32.6%; P < 0.001). CONCLUSION: A programmed reproductive management protocol may improve reproductive efficiency in dairy farms with seasonal breeding, by increasing submission and conception rates at the beginning of the breeding season and/or at the end of the voluntary waiting period. Fertility of cows bred after a PGF(2alpha) synchronised heat was greater than after an Ovsynch/TAI protocol.


Assuntos
Bovinos/fisiologia , Estro/efeitos dos fármacos , Lactação , Taxa de Gravidez , Reprodução/fisiologia , Animais , Indústria de Laticínios/métodos , Dinoprosta/administração & dosagem , Estro/fisiologia , Sincronização do Estro/métodos , Feminino , Fertilidade/fisiologia , Hormônio Liberador de Gonadotropina/administração & dosagem , Inseminação Artificial/veterinária , Poaceae , Gravidez , Fatores de Tempo
10.
Appl Radiat Isot ; 125: 9-14, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28390998

RESUMO

Current techniques for the measurement of radioactivity at various points during PET radiopharmaceutical production and R&D are based on the detection of the annihilation gamma rays from the radionuclide in the labelled compound. The detection systems to measure these gamma rays are usually variations of NaI or CsF scintillation based systems requiring costly and heavy lead shielding to reduce background noise. These detectors inherently suffer from low detection efficiency, high background noise and very poor linearity. They are also unable to provide any reasonably useful position information. A novel positron counting technique is proposed for the radioactivity assay during radiopharmaceutical manufacturing that overcomes these limitations. Detection of positrons instead of gammas offers an unprecedented level of position resolution of the radiation source (down to sub-mm) thanks to the nature of the positron interaction with matter. Counting capability instead of charge integration in the detector brings the sensitivity down to the statistical limits at the same time as offering very high dynamic range and linearity from zero to any arbitrarily high activity. This paper reports on a quantitative comparison between conventional detector systems and the proposed positron counting detector.

11.
Cell Death Differ ; 6(8): 813-20, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10467356

RESUMO

We previously demonstrated that the broad-spectrum caspase inhibitor, zVAD-fmk, totally deviated apoptosis to necrosis in B lymphocytes. We report here that, in contrast with zVAD-fmk, IL-4 protected B cells from spontaneous and from dexamethasone-induced apoptosis and actually maintained cell viability. This was assessed by morphological and biochemical criteria and accompanied by the maintenance of mitochondrial transmembrane potential (DeltaPsiCm) and elevated glutathione (GSH) levels. Under these conditions, zVAD-fmk also totally inhibited apoptosis in thymocytes, but it partly preserved cell viability with a parallel increase in the percentage of cells exhibiting high DeltaPsiCm and elevated GSH levels. Nevertheless, non-rescued cells were deviated to necrosis. Therefore, the pathway leading to either apoptosis or necrosis appears to involve common mitochondrial dysfunctions which could not be reversed by caspase inhibition, suggesting that the pharmacological inhibition of cell death should occur at an earlier stage.


Assuntos
Clorometilcetonas de Aminoácidos/metabolismo , Apoptose , Linfócitos B/efeitos dos fármacos , Inibidores de Cisteína Proteinase/farmacologia , Interleucina-4/metabolismo , Interleucina-4/farmacologia , Mitocôndrias/efeitos dos fármacos , Clorometilcetonas de Aminoácidos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linfócitos B/citologia , Linfócitos B/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Inibidores de Cisteína Proteinase/metabolismo , Dexametasona/farmacologia , Feminino , Glucocorticoides/farmacologia , Glutationa/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Necrose
12.
Genetics ; 150(2): 601-11, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9755193

RESUMO

Oxa1p is a mitochondrial inner membrane protein that is mainly required for the insertion/assembly of complex IV and ATP synthase and is functionally conserved in yeasts, humans, and plants. We have isolated several independent suppressors that compensate for the absence of Oxa1p. Molecular cloning and sequencing reveal that the suppressor mutations (CYT1-1 to -6) correspond to amino acid substitutions that are all located in the membrane anchor of cytochrome c1 and decrease the hydrophobicity of this anchor. Cytochrome c1 is a catalytic subunit of complex III, but the CYT1-1 mutation does not seem to affect the electron transfer activity. The double-mutant cyt1-1,164, which has a drastically reduced electron transfer activity, still retains the suppressor activity. Altogether, these results suggest that the suppressor function of cytochrome c1 is independent of its electron transfer activity. In addition to the membrane-bound cytochrome c1, carbonate-extractable forms accumulate in all the suppressor strains. We propose that these carbonate-extractable forms of cytochrome c1 are responsible for the suppressor function by preventing the degradation of the respiratory complex subunits that occur in the absence of Oxa1p.


Assuntos
Citocromos c1/genética , Proteínas Nucleares/fisiologia , Saccharomyces cerevisiae/enzimologia , Supressão Genética , Adenosina Trifosfatases/biossíntese , Sequência de Aminoácidos , Carbonatos , Membrana Celular/enzimologia , Clonagem Molecular , Citocromos c1/biossíntese , Análise Mutacional de DNA , Transporte de Elétrons , Complexo II de Transporte de Elétrons , Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons , Genes Fúngicos/genética , Proteínas Mitocondriais , Dados de Sequência Molecular , Complexos Multienzimáticos/metabolismo , Pressão Osmótica , Oxirredutases/metabolismo , Saccharomyces cerevisiae/genética , Succinato Desidrogenase/metabolismo
13.
Ann Fr Anesth Reanim ; 24(10): 1294-6, 2005 Oct.
Artigo em Francês | MEDLINE | ID: mdl-16183244

RESUMO

The duodenocaval fistula is exceptional. We report the case of a 44-year-old patient with duodenocaval fistula. The patient had no history of peptic ulcer disease. The clinical feature was firstly a septic shock and then an haemorrhagic shock. Only laparotomy confirmed the diagnosis. The treatment was a surgical one with a rapid improvement. The prognosis depends on surgical experience and remains serious.


Assuntos
Duodenopatias/complicações , Fístula/etiologia , Úlcera Péptica Perfurada/complicações , Veia Cava Inferior , Adulto , Duodenopatias/diagnóstico , Fístula/diagnóstico , Humanos , Laparotomia , Masculino , Úlcera Péptica Perfurada/diagnóstico , Ressuscitação , Choque Hemorrágico , Choque Séptico , Tomografia Computadorizada por Raios X
14.
J Clin Virol ; 69: 203-9, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26209408

RESUMO

BACKGROUND: The NS5A protein of the hepatitis C virus has been shown to be involved in the development of hepatocellular carcinoma. OBJECTIVES: In a French multicenter study, we investigated the clinical and epidemiological features of a new HCV genotype 1b strain bearing a wide insertion into the V3 domain. STUDY DESIGN: We studied NS5A gene sequences in 821 French patients infected with genotype 1b HCV. RESULTS: We identified an uncharacterized V3 insertion without ORF disruption in 3.05% of the HCV sequences. The insertion comprised 31 amino-acids for the majority of patients; 3 patients had 27 amino-acids insertions and 1 had a 12 amino-acids insertion. Sequence identity between the 31 amino-acids insertions and the V3 domain ranged from 48 to 96% with E-values above 4e(-5), thus illustrating sequence homology and a partial gene duplication event that to our knowledge has never been reported in HCV. Moreover we showed the presence of the duplication at the time of infection and its persistence at least during 12 years in the entire quasispecies. No association was found with extrahepatic diseases. Conversely, patients with cirrhosis were two times more likely to have HCV with this genetic characteristic (p=0.04). Moreover, its prevalence increased with liver disease severity (from 3.0% in patients without cirrhosis to 9.4% in patients with both cirrhosis and HCC, p for trend=0.045). CONCLUSIONS: We identified a duplicated V3 domain in the HCV-1b NS5A protein for the first time. The duplication may be associated with unfavorable evolution of liver disease including a possible involvement in liver carcinogenesis.


Assuntos
Carcinoma Hepatocelular/virologia , Hepacivirus/genética , Cirrose Hepática/virologia , Neoplasias Hepáticas/virologia , Mutagênese Insercional , Proteínas não Estruturais Virais/genética , Adulto , Idoso , Estudos Transversais , Feminino , França , Duplicação Gênica , Hepatite C Crônica/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estrutura Terciária de Proteína , RNA Viral/análise , Análise de Sequência de RNA , Proteínas não Estruturais Virais/química
15.
J Cereb Blood Flow Metab ; 16(3): 399-408, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8621744

RESUMO

There is a characteristic decrease in glucose metabolism in associative frontal and temporo-parietal cortices of patients suffering from Alzheimer's disease (AD). The decrease in metabolism might result from local neuronal loss or from a decrease of synaptic activity. We measured in vivo [11C]methionine accumulation into proteins with positron emission tomography (PET) to assess cortical tissue loss in AD. Both global regional activity and compartmental analysis were used to express [11C]methionine accumulation into brain tissue. Glucose metabolism was measures with [18F]fluorodeoxyglucose and autoradiographic method. Combined studies were performed in 10 patients with probable AD, compared to age-matched healthy volunteers. There was a significant 45% decrease of temporo-parietal glucose metabolism in patients with AD, and frontal metabolism was lowered in most patients. Temporo-parietal metabolism correlated to dementia severity. [11C]methionine incorporation into temporo-parietal and frontal cortices was not significantly decreased in AD. There was no correlation with clinical symptoms. Data suggest that regional tissue loss, assessed by the decrease of [11C]methionine accumulation, is not sufficient to explain cortical glucose hypometabolism, which reflects, rather, reduced synaptic connectivity.


Assuntos
Doença de Alzheimer/metabolismo , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Glucose/metabolismo , Metionina/metabolismo , Tomografia Computadorizada de Emissão , Idoso , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/psicologia , Radioisótopos de Carbono , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Escalas de Graduação Psiquiátrica , Índice de Gravidade de Doença , Distribuição Tecidual
16.
J Cereb Blood Flow Metab ; 15(5): 787-97, 1995 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7673371

RESUMO

Changes in serotonin-2 receptors have been demonstrated in brain autopsy material from patients with various neurodegenerative and affective disorders. It would be desirable to locate a ligand for the study of these receptors in vivo with positron emission tomography (PET). Altanserin is a 4-benzoylpiperidine derivative with a high affinity and selectivity for S2 receptors in vitro. Dynamic PET studies were carried out in nine normal volunteers with high-specific activity (376-1,680 mCi/mumol) [18F]altanserin. Arterial blood samples were obtained and the plasma time-activity curves were corrected for the presence of labeled metabolites. Thirty minutes after injection, selective retention of the radioligand was observed in cortical areas, while the cerebellum, caudate, and thalamus had low radioactivity levels. Specific binding reached a plateau between 30 and 65 min postinjection at 1.8% of the injected dose/L of brain and then decreased, indicating the reversibility of the binding. The total/nonspecific binding ratio reached 2.6 for times between 50 and 70 min postinjection. The graphical analysis proposed by Logan et al. allowed us to estimate the binding potential (Bmax/KD). Pretreatment with ketanserin was given to three volunteers and brain activity remained uniformly low. An additional study in one volunteer showed that [18F]altanserin can be displaced from the receptors by large doses of ketanserin. At the end of the study, unchanged altanserin was 57% of the total plasma activity. These results suggest that [18F]altanserin is selective for S2 receptors in vivo as it is in vitro. They indicate that [18F]altanserin is suitable for imaging and quantifying S2 receptors with PET in humans.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Ketanserina/análogos & derivados , Receptores de Serotonina/metabolismo , Tomografia Computadorizada de Emissão , Adulto , Cromatografia Líquida de Alta Pressão , Radioisótopos de Flúor , Humanos , Ketanserina/farmacocinética , Ketanserina/farmacologia , Valores de Referência , Fatores de Tempo , Distribuição Tecidual
17.
Gene ; 149(2): 271-6, 1994 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-7959001

RESUMO

cDNA clones encoding giant catfish (Pangasianodon gigas) growth hormone (GH) have been isolated using a polymerase chain reaction (PCR) strategy. Pairwise combinations of degenerate and general primers allowed for the amplification of regions both 3' and 5' to the point of entry into the message. The amplified PCR products were cloned and sequenced. The cDNA sequence was found to encode a polypeptide of 200 amino acids (aa), including a putative signal peptide of 22 aa. The 5' and 3' untranslated regions of the message are 58 and 515 nucleotides long, respectively. The giant catfish GH displays the highest aa sequence homology with the carp GH, with 80% of sequence identity. Moreover, giant catfish GH has structural features in common with both mammalian and avian GH polypeptides, and also contains the domains of conserved sequence found in other GH.


Assuntos
Peixes-Gato/genética , Hormônio do Crescimento/biossíntese , Sequência de Aminoácidos , Animais , Sequência de Bases , Carpas/genética , Clonagem Molecular/métodos , Primers do DNA , DNA Complementar , Hormônio do Crescimento/genética , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/métodos , RNA Mensageiro/biossíntese , Homologia de Sequência de Aminoácidos
18.
FEBS Lett ; 425(2): 266-70, 1998 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-9559663

RESUMO

The role of caspases in B lymphocyte cell death was investigated by using two broad spectrum inhibitors of the caspase family, Z-Asp-cmk and Z-VAD-fmk. They totally prevented spontaneous and drug-induced apoptosis and inhibited the CPP32/caspase-3-like activity exhibited by apoptotic cells. However, the suppression of apoptosis was not associated with a long-term increase of cell survival, but conversely, with a switch from apoptotic death to the necrotic form. These results strongly suggest that apoptosis and necrosis share common initiation pathways, the final issue being determined by the presence of an active caspase.


Assuntos
Clorometilcetonas de Aminoácidos/farmacologia , Apoptose , Linfócitos B/citologia , Linfócitos B/efeitos dos fármacos , Caspases , Cisteína Endopeptidases/metabolismo , Inibidores de Cisteína Proteinase/farmacologia , Necrose , Animais , Linfócitos B/enzimologia , Caspase 3 , Ativação Enzimática , Feminino , Camundongos , Camundongos Endogâmicos C57BL
19.
FEBS Lett ; 460(2): 203-6, 1999 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-10544235

RESUMO

The REtsAF cell line expresses a temperature-sensitive mutant of the SV40 large tumor antigen. At restrictive temperature (39.5 degrees C), the cells undergo p53-mediated apoptosis, which can be inhibited by Bcl-2. Here, we show that Z-VAD-fmk, a caspase inhibitor, can suppress the Bcl-2-dependent cell survival at 39.5 degrees C. This result suggests that a caspase-like activity can act as an inhibitor of apoptosis in this model, downstream of Bcl-2. Our results also suggest that this activity may be up-regulated by Bcl-2 and may be responsible for cleavage of the tumor suppressor Rb protein.


Assuntos
Apoptose , Inibidores de Caspase , Sobrevivência Celular/efeitos dos fármacos , Genes bcl-2/efeitos dos fármacos , Clorometilcetonas de Aminoácidos/farmacologia , Animais , Western Blotting , Linhagem Celular , Inibidores de Cisteína Proteinase/farmacologia , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Fibroblastos/metabolismo , Oligopeptídeos/farmacologia , Ratos , Transdução de Sinais , Estaurosporina/farmacologia , Temperatura , Tetraciclina/farmacologia , Fatores de Tempo
20.
Mech Ageing Dev ; 103(3): 285-99, 1998 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-9723904

RESUMO

We have investigated the influence of age on B-cell responsiveness. The present study showed that the B-cell mitogen, lipopolysaccharide (LPS), similarly stimulated the proliferation of purified B lymphocytes obtained from either young mice (3 months) or old mice (24 months). In contrast, expression of the differentiation marker, alkaline phosphatase (ALP), was about fourfold higher in young mice than in older mice upon stimulation with LPS or with dextran sulfate (DXS) and interleukin-5 (IL-5). The occurrence of apoptosis during aging was then studied: unexpectedly, spontaneous cell death was double in B lymphocytes from young mice compared to older animals. Stimulation with DXS with or without IL-5 rescued B lymphocytes from cell death in young mice but protection decreased with aging, and no longer occurred in 24-month-old mice B cells. Meanwhile, the protective activity conferred by IL-4 was maintained at similar levels throughout aging. However, B cells from old mice were more responsive to apoptosis induction with cycloheximide, dibutyryl cAMP and dexamethasone. Together, the present results indicate an age-associated alteration in apoptosis and activation of B lymphocytes which could contribute to the age-related decline of the immune response.


Assuntos
Envelhecimento/imunologia , Apoptose/imunologia , Linfócitos B/imunologia , Fosfatase Alcalina/metabolismo , Animais , Apoptose/efeitos dos fármacos , Divisão Celular/imunologia , Feminino , Camundongos , Camundongos Endogâmicos
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