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1.
Parasit Vectors ; 14(1): 354, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34225777

RESUMO

BACKGROUND: Zoonotic diseases are a serious threat to both public health and animal conservation. Most non-human primates (NHP) are facing the threat of forest loss and fragmentation and are increasingly living in closer spatial proximity to humans. Humans are infected with soil-transmitted helminths (STH) at a high prevalence, and bidirectional infection with NHP has been observed. The aim of this study was to determine the prevalence, genetic diversity, distribution and presence of co-infections of STH in free-ranging gorillas, chimpanzees and other NHP species, and to determine the potential role of these NHP as reservoir hosts contributing to the environmental sustenance of zoonotic nematode infections in forested areas of Cameroon and Gabon. METHODS: A total of 315 faecal samples from six species of NHPs were analysed. We performed PCR amplification, sequencing and maximum likelihood analysis of DNA fragments of the internal transcribed spacer 2 (ITS2) nuclear ribosomal DNA to detect the presence and determine the genetic diversity of Oesophagostomum spp., Necator spp. and Trichuris spp., and of targeted DNA fragments of the internal transcribed spacer 1 (ITS1) to detect the presence of Ascaris spp. RESULTS: Necator spp. infections were most common in gorillas (35 of 65 individuals), but also present in chimpanzees (100 of 222 individuals) and in one of four samples from greater spot-nosed monkeys. These clustered with previously described type II and III Necator spp. Gorillas were also the most infected NHP with Oesophagostomum (51/65 individuals), followed by chimpanzees (157/222 individuals), mandrills (8/12 samples) and mangabeys (7/12 samples), with O. stephanostomum being the most prevalent species. Oesophagostomum bifurcum was detected in chimpanzees and a red-capped mangabey, and a non-classified Oesophagostomum species was detected in a mandrill and a red-capped mangabey. In addition, Ternidens deminutus was detected in samples from one chimpanzee and three greater spot-nosed monkeys. A significant relative overabundance of co-infections with Necator and Oesophagostomum was observed in chimpanzees and gorillas. Trichuris sp. was detected at low prevalence in a gorilla, a chimpanzee and a greater spot-nosed monkey. No Ascaris was observed in any of the samples analysed. CONCLUSIONS: Our results on STH prevalence and genetic diversity in NHP from Cameroon and Gabon corroborate those obtained from other wild NHP populations in other African countries. Future research should focus on better identifying, at a molecular level, the species of Necator and Oesophagostomum infecting NHP and determining how human populations may be affected by increased proximity resulting from encroachment into sylvatic STH reservoir habitats.


Assuntos
Animais Selvagens/parasitologia , DNA de Helmintos/genética , Helmintíase Animal/epidemiologia , Helmintíase Animal/transmissão , Helmintos/genética , Primatas/parasitologia , Solo/parasitologia , Animais , Camarões/epidemiologia , Fezes/parasitologia , Feminino , Gabão/epidemiologia , Helmintos/classificação , Helmintos/isolamento & purificação , Masculino , Primatas/classificação , Zoonoses/epidemiologia , Zoonoses/parasitologia , Zoonoses/transmissão
3.
Spinal Cord ; 54(12): 1176-1182, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27163450

RESUMO

STUDY DESIGN: This cross-sectional chart review study included 100 US Veterans with spinal cord injuries/disorders (SCI/D) who received care at a Veterans Affairs (VA) SCI facility during a 12-month period. Progress notes were examined to extract need for weight management (WM), patient-provider discussions about risk due to overweight/obesity, recommended lifestyle changes and/or follow-up and WM education. OBJECTIVES: To understand what WM services are offered to Veterans with SCI/D within the VA SCI System of Care during comprehensive preventive health evaluations (annual evaluations), inpatient stays and outpatient visits. SETTING: VA SCI System of Care, Department of Veterans Affairs, United States. RESULTS: Overall, 73% demonstrated a need for WM. Weight was most frequently addressed during the nutrition assessment of annual evaluations, but this assessment was most likely to be skipped. Nutrition histories were missing many key components. Over half received WM education; individuals who were described as overweight/obese by their provider were more likely to receive education. Most of the Veterans who were seen in an inpatient setting were weighed; weight was only discussed with 12%. Less than half of the Veterans with outpatient visits were weighed, and 23% received WM recommendations. CONCLUSIONS: Weight was frequently discussed during nutrition assessments, but infrequently addressed during outpatient or inpatient encounters. Few Veterans received specific recommendations on caloric/nutrient requirements and nutrition histories were missing recommended elements. Additional work is needed to help providers to incorporate WM information into care.


Assuntos
Manutenção do Peso Corporal , Traumatismos da Medula Espinal/reabilitação , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Seguimentos , Hospitais de Veteranos , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação Nutricional , Pacientes Ambulatoriais , Sobrepeso/prevenção & controle , Educação de Pacientes como Assunto , Estados Unidos , United States Department of Veterans Affairs
4.
Cell Death Differ ; 23(4): 555-64, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25526092

RESUMO

Epigenetic changes on DNA and chromatin are implicated in cell differentiation and organogenesis. For the heart, distinct histone methylation profiles were recently linked to stage-specific gene expression programs during cardiac differentiation in vitro. However, the enzymes catalyzing these modifications and the genes regulated by them remain poorly defined. We therefore decided to identify the epigenetic enzymes that are potentially involved in cardiomyogenesis by analyzing the expression profile of the 85 genes encoding the epigenetic-related proteins in mouse cardiomyocytes (CMs), and then study how they affect gene expression during differentiation and maturation of this cell type. We show here with gene expression screening of epigenetic enzymes that the highly expressed H3 methyltransferase disruptor of telomeric silencing 1-like (DOT1L) drives a transitional pattern of di-methylation on H3 lysine 79 (H3K79) in CMs at different stages of differentiation in vitro and in vivo. Through a genome-wide chromatin-immunoprecipitation DNA-sequencing approach, we found H3K79me2 enriched at genes expressed during cardiac differentiation. Moreover, knockdown of Dot1L affected the expression of H3K79me2-enriched genes. Our results demonstrate that histone methylation, and in particular DOT1L-mediated H3K79me2 modification, drives cardiomyogenesis through the definition of a specific transcriptional landscape.


Assuntos
Diferenciação Celular , Regulação da Expressão Gênica , Histonas/metabolismo , Metiltransferases/metabolismo , Miócitos Cardíacos/metabolismo , Processamento de Proteína Pós-Traducional , Animais , Linhagem Celular , Histona-Lisina N-Metiltransferase , Histonas/genética , Metiltransferases/genética , Camundongos
5.
Leukemia ; 28(9): 1861-71, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24561519

RESUMO

Relapsed/refractory Hodgkin's lymphoma (HL) is an unmet medical need requiring new therapeutic options. Interactions between the histone deacetylase inhibitor Givinostat and the RAF/MEK/ERK inhibitor Sorafenib were examined in HDLM-2 and L-540 HL cell lines. Exposure to Givinostat/Sorafenib induced a synergistic inhibition of cell growth (range, 70-80%) and a marked increase in cell death (up to 96%) due to increased H3 and H4 acetylation and strong mitochondrial injury. Gene expression profiling indicated that the synergistic effects of Givinostat/Sorafenib treatment are associated with the modulation of cell cycle and cell death pathways. Exposure to Givinostat/Sorafenib resulted in sustained production of reactive oxygen species (ROS) and activation of necroptotic cell death. The necroptosis inhibitor Necrostatin-1 prevented Givinostat/Sorafenib-induced ROS production, mitochondrial injury, activation of BH3-only protein BIM and cell death. Knockdown experiments identified BIM as a key signaling molecule that mediates Givinostat/Sorafenib-induced oxidative death of HL cells. Furthermore, in vivo xenograft studies demonstrated a 50% reduction in tumor burden (P<0.0001), a 5- to 15-fold increase in BIM expression (P < 0.0001) and a fourfold increase in tumor necrosis in Givinostat/Sorafenib-treated animals compared with mice that received single agents. These results provide a rationale for exploring Givinostat/Sorafenib combination in relapsed/refractory HL.


Assuntos
Proteínas Reguladoras de Apoptose/fisiologia , Carbamatos/administração & dosagem , Inibidores de Histona Desacetilases/administração & dosagem , Doença de Hodgkin/tratamento farmacológico , Proteínas de Membrana/fisiologia , Niacinamida/análogos & derivados , Compostos de Fenilureia/administração & dosagem , Proteínas Proto-Oncogênicas/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Animais , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/genética , Proteína 11 Semelhante a Bcl-2 , Linhagem Celular Tumoral , Doença de Hodgkin/patologia , Humanos , Imidazóis/farmacologia , Indóis/farmacologia , Proteínas de Membrana/genética , Camundongos , Camundongos SCID , Necrose , Niacinamida/administração & dosagem , Proteínas Proto-Oncogênicas/genética , Sorafenibe , Regulação para Cima , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Cell Death Dis ; 4: e863, 2013 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-24136227

RESUMO

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) acts as an apoptosis inducer for cancer cells sparing non-tumor cell targets. However, several phase I/II clinical trials have shown limited benefits of this molecule. In the present work, we investigated whether cell susceptibility to TRAIL ligation could be due to the presence of TRAIL death receptors (DRs) 4 and 5 in membrane microdomains called lipid rafts. We performed a series of analyses, either by biochemical methods or fluorescence resonance energy transfer (FRET) technique, on normal cells (i.e. lymphocytes, fibroblasts, endothelial cells), on a panel of human cancer B-cell lines as well as on CD19(+) lymphocytes from patients with B-chronic lymphocytic leukemia, treated with different TRAIL ligands, that is, recombinant soluble TRAIL, specific agonistic antibodies to DR4 and DR5, or CD34(+) TRAIL-armed cells. Irrespective to the expression levels of DRs, a molecular interaction between ganglioside GM3, abundant in lymphoid cells, and DR4 was detected. This association was negligible in all non-transformed cells and was strictly related to TRAIL susceptibility of cancer cells. Interestingly, lipid raft disruptor methyl-beta-cyclodextrin abrogated this susceptibility, whereas the chemotherapic drug perifosine, which induced the recruitment of TRAIL into lipid microdomains, improved TRAIL-induced apoptosis. Accordingly, in ex vivo samples from patients with B-chronic lymphocytic leukemia, the constitutive embedding of DR4 in lipid microdomains was associated per se with cell death susceptibility, whereas its exclusion was associated with TRAIL resistance. These results provide a key mechanism for TRAIL sensitivity in B-cell malignances: the association, within lipid microdomains, of DR4 but not DR5, with a specific ganglioside, that is the monosialoganglioside GM3. On these bases we suggest that lipid microdomains could exert a catalytic role for DR4-mediated cell death and that an ex vivo quantitative FRET analysis could be predictive of cancer cell sensitivity to TRAIL.


Assuntos
Apoptose/efeitos dos fármacos , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucemia Linfocítica Crônica de Células B/patologia , Microdomínios da Membrana/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF/farmacologia , Anticorpos/farmacologia , Antígenos CD34/metabolismo , Linhagem Celular Transformada , Linhagem Celular Tumoral , Separação Celular , Citometria de Fluxo , Humanos , Microdomínios da Membrana/efeitos dos fármacos , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/agonistas , Solubilidade
7.
Exp Parasitol ; 135(2): 257-61, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23850999

RESUMO

We evaluated the use of an RNA stabilisation buffer, RNAlater (Ambion, Austin, Texas), as a preservation medium for parasitic coprology analysis of faecal samples collected from chimpanzees living in the wild (Pan troglodytes troglodytes). Thirty faecal samples collected in the forests of south-east Cameroon (Mambele area) from 2003 to 2011 were preserved in RNAlater at -80 °C and analysed for their parasite content. We identified and counted parasitic elements and assessed their shape, size and morphology in relation to the storage time of the samples. We found that parasite elements were identifiable in RNAlater preserved samples after as many as 7 years, showing that RNAlater could be an effective and reliable preservation medium for coprology. Thus, its use could be an interesting way to optimise sample collection for several types of studies (parasitology and bacteriology/virology) at once, especially considering the logistically challenging and time-consuming field campaigns needed to obtain these faecal samples.


Assuntos
Doenças dos Símios Antropoides/parasitologia , Fezes/parasitologia , Pan troglodytes/parasitologia , Doenças Parasitárias em Animais/parasitologia , Preservação Biológica/métodos , Animais , Animais Selvagens , Soluções Tampão , Parasitos/classificação , Parasitos/genética , Parasitos/isolamento & purificação , RNA/normas
8.
Leukemia ; 27(8): 1677-87, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23360848

RESUMO

The effects of the Akt inhibitor perifosine and the RAF/MEK/ERK inhibitor sorafenib were investigated using two CD30(+)Hodgkin lymphoma cell lines (L-540 and HDLM-2) and the CD30(-)HD-MyZ histiocytic cell line. The combined perifosine/sorafenib treatment significantly inhibited mitogen-activated protein kinase and Akt phosphorylation in two of the three cell lines. Profiling of the responsive cell lines revealed that perifosine/sorafenib decreased the amplitude of transcriptional signatures that are associated with the cell cycle, DNA replication and cell death. Tribbles homolog 3 (TRIB3) was identified as the main mediator of the in vitro and in vivo antitumor activity of perifosine/sorafenib. Combined treatment compared with single agents significantly suppressed cell growth (40-80%, P<0.001), induced severe mitochondrial dysfunction and necroptotic cell death (up to 70%, P<0.0001) in a synergistic manner. Furthermore, in vivo xenograft studies demonstrated a significant reduction in tumor burden (P<0.0001), an increased survival time (81 vs 45 days, P<0.0001), an increased apoptosis (2- to 2.5-fold, P<0.0001) and necrosis (2- to 8-fold, P<0.0001) in perifosine/sorafenib-treated animals compared with mice receiving single agents. These data provide a rationale for clinical trials using perifosine/sorafenib combination.


Assuntos
Apoptose/efeitos dos fármacos , Doença de Hodgkin/metabolismo , Mitocôndrias/efeitos dos fármacos , Niacinamida/análogos & derivados , Compostos de Fenilureia/farmacologia , Fosforilcolina/análogos & derivados , Animais , Protocolos de Quimioterapia Combinada Antineoplásica , Caspases/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Análise por Conglomerados , Sinergismo Farmacológico , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Doença de Hodgkin/tratamento farmacológico , Doença de Hodgkin/genética , Doença de Hodgkin/patologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Mitocôndrias/metabolismo , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Necrose , Niacinamida/administração & dosagem , Niacinamida/farmacologia , Compostos de Fenilureia/administração & dosagem , Fosforilcolina/administração & dosagem , Fosforilcolina/farmacologia , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sorafenibe , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Bioresour Technol ; 98(3): 648-53, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16630719

RESUMO

The enzymatic production of biodiesel by methanolysis of cottonseed oil was studied using immobilized Candida antarctica lipase as catalyst in t-butanol solvent. Methyl ester production and triacylglycerol disappearance were followed by HPLC chromatography. It was found, using a batch system, that enzyme inhibition caused by undissolved methanol was eliminated by adding t-butanol to the reaction medium, which also gave a noticeable increase of reaction rate and ester yield. The effect of t-butanol, methanol concentration and temperature on this system was determined. A methanolysis yield of 97% was observed after 24h at 50 degrees C with a reaction mixture containing 32.5% t-butanol, 13.5% methanol, 54% oil and 0.017 g enzyme (g oil)(-1). With the same mixture, a 95% ester yield was obtained using a one step fixed bed continuous reactor with a flow rate of 9.6 mlh(-1) (g enzyme)(-1). Experiments with the continuous reactor over 500 h did not show any appreciable decrease in ester yields.


Assuntos
Óleo de Sementes de Algodão/química , Gasolina , Lipase/metabolismo , terc-Butil Álcool/química , Catálise , Enzimas Imobilizadas , Proteínas Fúngicas , Temperatura
10.
J Psychiatr Res ; 36(1): 27-32, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-11755458

RESUMO

The brain is the most cholesterol-rich organ in the human body. Accumulation of excess cholesterol in hippocampal neurons promotes the cleavage of the amyloid precursor protein (APP) into amyloidogenic components with the consequence of the acceleration of neuronal degeneration. Conversion of cholesterol to 24S-hydroxycholesterol mediated by cholesterol 24S-hydroxylase (CYP46) is the major pathway for the elimination of brain cholesterol and the maintenance of brain cholesterol homeostasis. We examined whether cerebrospinal fluid (CSF) 24S-hydroxycholesterol levels differ between patients with dementia, patients with mild cognitive impairment (MCI), and cognitively intact control subjects. Plasma and CSF concentrations of 24S-hydroxycholesterol and cholesterol in 32 patients with Alzheimer's disease (AD), 11 patients with vascular dementia, seven patients with MCI, and seven cognitively intact control subjects were measured by combined gas-chromatography/mass spectrometry. We show elevated concentrations of 24S-hydroxycholesterol in the CSF of AD patients and we interpret this finding as a consequence of increased cholesterol turnover in the central nervous system during neurodegeneration. The observed influence of the apolipoprotein E epsilon4 (APOE4) allele on CSF 24S-hydroxycholesterol concentrations with a gene-dosage effect suggests the existence of a link between the AD risk factor APOE4 and CNS cholesterol metabolism. The elevation of CSF 24S-hydroxycholesterol appears to occur early in the disease process, since patients with mild cognitive impairment had also increased CSF concentrations of this compound. We believe that the CSF concentration of 24S-hydroxycholesterol is altered in AD-related neurodegeneration and thus, CSF 24S-hydroxycholesterol may be a marker for monitoring the onset and progression of the disease.


Assuntos
Doença de Alzheimer/líquido cefalorraquidiano , Demência Vascular/líquido cefalorraquidiano , Hidroxicolesteróis/líquido cefalorraquidiano , Idoso , Doença de Alzheimer/sangue , Análise de Variância , Apolipoproteínas E/sangue , Apolipoproteínas E/genética , Colesterol/sangue , Colesterol/líquido cefalorraquidiano , Demência Vascular/sangue , Feminino , Humanos , Hidroxicolesteróis/sangue , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
11.
Mol Genet Genomics ; 265(4): 576-84, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11459177

RESUMO

Members of the MSI/RbAp sub-family of WD-repeat proteins are widespread in eukaryotic organisms and form part of multiprotein complexes that are involved in various biological pathways, including chromatin assembly, regulation of gene transcription, and cell division. In this study we report the isolation and characterization of a cDNA sequence from Zea mays, which encodes an RbAp-like protein (ZmRbAp1) that binds acetylated histones H3 and H4 and suppresses mutations that have a negative effect on the Ras/cAMP pathway in yeast. The ZmRbAp genes form a gene family and are expressed in different tissues of Z. mays L. plants. Determination of its expression pattern during maize seed development revealed that ZmRbAp transcripts are abundant during the initial stages of endosperm formation. In addition, the transcripts are specifically localized in shoot apical meristem and leaf primordia of the embryo. A possible role for the ZmRbAp genes in early endosperm differentiation and plant development is discussed.


Assuntos
Proteínas de Transporte/genética , Proteínas Cromossômicas não Histona , Proteínas Fúngicas , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Família Multigênica , Proteínas de Plantas/genética , Sementes/metabolismo , Zea mays/genética , Acetilação , Sequência de Aminoácidos , Proteínas de Transporte/biossíntese , Proteínas de Transporte/química , Núcleo Celular/metabolismo , AMP Cíclico/fisiologia , DNA Complementar/genética , Histonas/metabolismo , Temperatura Alta , Meristema/metabolismo , Chaperonas Moleculares/fisiologia , Dados de Sequência Molecular , Peso Molecular , Especificidade de Órgãos , Folhas de Planta/embriologia , Proteínas de Plantas/biossíntese , Proteínas de Plantas/química , Proteínas Recombinantes de Fusão/fisiologia , Sequências Repetitivas de Aminoácidos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Transcrição Gênica , Zea mays/embriologia , Proteínas ras/genética , Proteínas ras/fisiologia
12.
Acta Paediatr ; 90(6): 652-7, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11440099

RESUMO

UNLABELLED: Oxysterols, particularly those hydroxylated in the steroid side-chain, are formed from cholesterol by specific cytochrome P450 enzymes and may facilitate elimination of cholesterol from extrahepatic sources. In humans, the greatest portion of circulating 24S-hydroxycholesterol (24S-OH-Chol) is derived from the brain and the absolute concentration depends on age. In the present study, concentrations of 24S-OH-Chol and for comparison 27-OH-Chol were determined by a highly sensitive isotope dilution method using gas chromatography-mass spectrometry in serum samples from normal preterm and term neonates and those with Rhesus haemolytic disease, taken serially for diagnostic purposes. Serum concentrations of cholesterol, 24S-OH-Chol and 27-OH-Chol were similar in venous versus arterial cord blood of 6 term neonates. Serum concentrations of 24S-OH-Chol and 27-OH-Chol in 12 small for gestational age (SGA) preterm neonates were significantly lower than those in 12 appropriate for gestational age (AGA) preterm neonates (p < 0.001), and also lower than those in 12 SGA (0 < 0.001) and 12 AGA term neonates (p < 0.05). Serum cholesterol was significantly higher in preterm than in term neonates (p < 0.001). 24S-OH-Chol serially determined in 8 infants with Rhesus haemolytic disease increased 5-6-fold during the first 3 mo after birth (from 42 +/- 20 ng ml(-1) to 227 +/- 71 ng ml(-1)). 27-OH-Chol increased simultaneously from 30 +/- 14 ng ml(-1) to 100 +/- 39 ng ml(-1). CONCLUSION: Serum concentrations of 24S-OH-Chol increased 5-6-fold after birth. This could be an indication of normal cholesterol metabolism in the developing neonatal brain.


Assuntos
Encéfalo/metabolismo , Colesterol/farmacocinética , Feto/metabolismo , Hidroxicolesteróis/sangue , Recém-Nascido/metabolismo , Eritroblastose Fetal/sangue , Humanos , Recém-Nascido Prematuro/sangue , Recém-Nascido Pequeno para a Idade Gestacional/metabolismo , Estudos Longitudinais
14.
Neuroreport ; 11(9): 1959-62, 2000 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-10884051

RESUMO

The conversion of brain cholesterol into 24S-hydroxycholesterol and its subsequent release into the periphery is probably an important step for the maintenance of brain cholesterol homeostasis. Recent findings suggest that plasma 24S-hydroxycholesterol may be elevated in Alzheimer's disease (AD) and vascular dementia at least at some stage of the disease, suggesting increased brain cholesterol turnover during neurodegeneration. We investigated whether plasma 24S-hydroxycholesterol concentrations depend on the severity of AD and on the apolipoprotein E (apoE) genotype. Severity of AD and inheritance of the apoE4 allele were independently associated with reduced plasma 24S-hydroxycholesterol/cholesterol ratios. The results suggest that the decrease of plasma 24S-hydroxycholesterol/cholesterol in severely affected AD patients is a peripheral marker for loss of cholesterol 24S-hydroxylase in the CNS. Inheritance of the apoE4 allele may be associated with increased apoE-mediated transport of brain cholesterol to the periphery or with decreased activity of the 24S-hydroxylase. Longitudinal studies will assess the validity of the ratio plasma 24S-hydroxycholesterol/cholesterol as a state marker for AD.


Assuntos
Doença de Alzheimer/sangue , Hidroxicolesteróis/sangue , Degeneração Neural/sangue , Idoso , Doença de Alzheimer/psicologia , Apolipoproteínas E/genética , Biomarcadores/sangue , Feminino , Genótipo , Humanos , Masculino , Índice de Gravidade de Doença
15.
J Lipid Res ; 41(2): 195-8, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10681402

RESUMO

Alzheimer's disease (AD) is characterized by the presence of senile plaques, neurofibrillary tangles, and neuronal cell loss associated with membrane cholesterol release. 24S-hydroxycholesterol (24S-OH-Chol) is an enzymatically oxidized product of cholesterol mainly synthesized in the brain. We tested the hypothesis that plasma levels of this oxysterol could be used as a putative biochemical marker for an altered cholesterol homeostasis in the brain of AD patients. Thirty patients with clinical criteria for AD, 30 healthy volunteers, 18 depressed patients, and 12 patients with vascular dementia (non-Alzheimer demented) were studied. Plasma concentrations of 24S-OH-Chol were assayed by isotope dilution;-mass spectrometry, cholesterol was measured enzymatically, and apolipoprotein E (apoE) was genotyped by polymerase chain reaction and restricted fragment length polymorphism. The concentration of 24S-OH-Chol in AD and non-Alzheimer demented patients was modestly but significantly higher than in healthy controls and in depressed patients. There was no significant difference in the concentrations of 24S-OH-Chol between depressed patients and healthy controls nor between AD and non-Alzheimer demented patients. The apoE straightepsilon4 allele influences plasma 24S-OH-Chol. However, this influence could be completely accounted for by the elevated plasma cholesterol in apoE4 hetero- or homozygotes. Plasma 24S-OH-Chol levels correlated negatively with the severity of dementia. AD and vascular demented patients appear to have higher circulating levels of 24S-OH-Chol than depressed patients and healthy controls. We speculate that 24S-OH-Chol plasma levels may potentially be used as an early biochemical marker for an altered cholesterol homeostasis in the central nervous system. 24S-hydroxycholesterol (cerebrosterol) is increased in Alzheimer and vascular demented patients.


Assuntos
Doença de Alzheimer/sangue , Demência Vascular/sangue , Hidroxicolesteróis/sangue , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/genética , Apolipoproteínas E/genética , Biomarcadores/sangue , Estudos de Casos e Controles , Colesterol/sangue , Demência Vascular/diagnóstico , Demência Vascular/genética , Depressão/sangue , Depressão/diagnóstico , Depressão/genética , Diagnóstico Diferencial , Feminino , Genótipo , Homeostase , Humanos , Masculino , Pessoa de Meia-Idade
16.
J Immunol ; 162(11): 6312-5, 1999 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-10352241

RESUMO

Staphylococcal enterotoxins are bacterial products that display superantigen activity in vitro as well as in vivo. For instance, staphylococcal enterotoxin B (SEB) polyclonally activates T cells that bear the Vbeta8 gene segment of the TCR. SEB-activated T cells undergo a burst of proliferation that is followed by apoptosis. Using an in vivo adaptation of a fluorescent cell division monitoring technique, we show here that SEB-activated T cells divide asynchronously, and that apoptosis of superantigen-activated T cells is preferentially restricted to cells which have undergone a discrete number of cell divisions. Collectively, our data suggest that superantigen-activated T cells are programmed to undergo a fixed number of cell divisions before undergoing apoptosis. A delayed death program may provide a mechanistic compromise between effector functions and homeostasis of activated T cells.


Assuntos
Apoptose/imunologia , Ativação Linfocitária , Superantígenos/imunologia , Linfócitos T/citologia , Linfócitos T/imunologia , Animais , Anexina A5/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Divisão Celular/imunologia , Enterotoxinas/imunologia , Citometria de Fluxo , Fluoresceínas/metabolismo , Contagem de Linfócitos , Camundongos , Camundongos Endogâmicos BALB C , Staphylococcus aureus/imunologia , Succinimidas/metabolismo , Linfócitos T/metabolismo
17.
J Neural Transm ; 64(3-4): 199-210, 1985.
Artigo em Inglês | MEDLINE | ID: mdl-3003250

RESUMO

The function of the hypothalamic tuberoinfundibular dopaminergic (TIDA) neurons involved in the control of prolactin secretion was investigated in aged subjects with the use of nomifensine, an indirect-acting dopamine (DA) agonist, domperidone, a DA receptor antagonist, and DA, which acts directly on the pituitary lactotropes. In all 33 women, aged 69-92 yr, were studied. Baseline prolactin values were slightly but significantly higher in aged women (13 +/- 1.2 ng/ml, M +/- S.E.M.) than in a group of control fertile women (8 +/- 0.7 ng/ml). Oral administration of nomifensine (200 mg), in 14 aged women suppressed plasma prolactin (greater than or equal to 30% of baseline) in 8 subjects, a proportion not different from that present in fertile women (7/15) also receiving a single oral dose of nomifensine. Intravenous infusion of DA (0.04 microgram/kg min, 120 min) induced a similar inhibition in plasma prolactin in the aged and the fertile women, while administration of domperidone (4 mg i.v.) evoked a higher plasma prolactin rise, 15 min post-administration, in fertile than aged women. In all, presence of baseline prolactin levels only slightly elevated and prolactin responsiveness to nomifensine and DA not different from that of fertile women denote preservation of TIDA neuronal function in old women. The blunted response to domperidone of the old women is likely attibutable to a reduced pituitary pool of prolactin.


Assuntos
Dopamina/fisiologia , Hipotálamo/fisiologia , Prolactina/metabolismo , Adolescente , Adulto , Fatores Etários , Idoso , Animais , Domperidona/farmacologia , Feminino , Humanos , Hipotálamo/efeitos dos fármacos , Nomifensina/farmacologia , Ratos , Especificidade da Espécie , Transmissão Sináptica/efeitos dos fármacos
18.
Acta Endocrinol (Copenh) ; 103(3): 315-20, 1983 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6880568

RESUMO

Cirrhotic patients reportedly show alterations of anterior pituitary hormone secretion, which may reflect an underlying defective central neurotransmitter function. In this study, we have investigated the catecholaminergic control of prolactin (Prl) and growth hormone (GH) secretion in cirrhotic patients by means of an indirectly acting dopamine (DA) and norepinephrine agonist, nomifensine (Nom), and a DA receptor antagonist, domperidone (Dom). Basal GH levels were higher in the 12 female and male cirrhotic patients than in the 12 age- and sex-matched normal controls, while no difference was present in basal Prl values. Administration of Nom (200 mg po) suppressed basal Prl levels (at least 30% inhibition at three consecutive times post-drug administration) in 6/12 controls and in 6/12 cirrhotic patients, the frequency of negative responses not being different between the two groups. Nom induced a slight elevation of GH levels in controls, and evoked a more marked and sustained GH increase in cirrhotic patients. Administration of Dom (4 mg iv) induced similar Prl increments in 6 male controls and 6 male cirrhotic patients. Normal Prl responsiveness to Nom and Dom points to the existence of preserved tubero-infundibular DA function and modulation of pituitary DA receptors in the cirrhotic patients investigated. Higher GH responsiveness to Nom is compatible with a different bioavailability of the drug.


Assuntos
Domperidona/farmacologia , Hormônio do Crescimento/metabolismo , Isoquinolinas/farmacologia , Cirrose Hepática Alcoólica/fisiopatologia , Nomifensina/farmacologia , Prolactina/metabolismo , Receptores Dopaminérgicos/efeitos dos fármacos , Adulto , Feminino , Humanos , Hipotálamo/efeitos dos fármacos , Cirrose Hepática Alcoólica/sangue , Masculino , Pessoa de Meia-Idade , Adeno-Hipófise/efeitos dos fármacos
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