Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 57
Filtrar
1.
J Transl Genet Genom ; 5(4): 423-442, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35342877

RESUMO

Aim: To molecularly characterize the tumor microenvironment and evaluate immunologic parameters in canine glioma patients before and after treatment with oncolytic human IL-12-expressing herpes simplex virus (M032) and in treatment naïve canine gliomas. Methods: We assessed pet dogs with sporadically occurring gliomas enrolled in Stage 1 of a veterinary clinical trial that was designed to establish the safety of intratumoral oncoviral therapy with M032, a genetically modified oncolytic herpes simplex virus. Specimens from dogs in the trial and dogs not enrolled in the trial were evaluated with immunohistochemistry, NanoString, Luminex cytokine profiling, and multi-parameter flow cytometry. Results: Treatment-naive canine glioma microenvironment had enrichment of Iba1 positive macrophages and minimal numbers of T and B cells, consistent with previous studies identifying these tumors as immunologically "cold". NanoString mRNA profiling revealed enrichment for tumor intrinsic pathways consistent with suppression of tumor-specific immunity and support of tumor progression. Oncolytic viral treatment induced an intratumoral mRNA transcription signature of tumor-specific immune responses in 83% (5/6) of canine glioma patients. Changes included mRNA signatures corresponding with interferon signaling, lymphoid and myeloid cell activation, recruitment, and T and B cell immunity. Multiplexed protein analysis identified a subset of oligodendroglioma subjects with increased concentrations of IL-2, IL-7, IL-6, IL-10, IL-15, TNFα, GM-CSF between 14 and 28 days after treatment, with evidence of CD4+ T cell activation and modulation of IL-4 and IFNγ production in CD4+ and CD8+ T cells isolated from peripheral blood. Conclusion: These findings indicate that M032 modulates the tumor-immune microenvironment in the canine glioma model.

2.
Hipertens Riesgo Vasc ; 37(1): 33-38, 2020.
Artigo em Espanhol | MEDLINE | ID: mdl-31401091

RESUMO

Given the fact that new guidelines from the American Heart Association (AHA) and American College of Cardiology (ACC) propose important changes in the definition of hypertension, from equal or greater than 140/90mmHg to equal or greater than 130/80mmHg, major debate has been generated about the diagnostic criteria and the treatment of high blood pressure (HBP). In addition, these guidelines recommend that in order to achieve control of hypertension the goal should be a reading lower than 130/80mmHg. These new figures will significantly increase the amount of individuals considered hypertensive, some of whom will need more medication to achieve the new goal. This paradigm has led to questioning the goal's clinical applicability given the enormous financial burden that would result from treating millions of new hypertensive patients. The academic validity of the AHA-ACC guidelines has also been questioned given the fact that the recommendations emerged basically from results obtained from a single study with important methodological differences compared to the majority of studies carried out previously. Furthermore, its outcomes are inconsistent with those of previous studies. This conflict has led to some scientific institutions, such as the Latin American Society of Hypertension (LASH), continuing to adhere to the previous recommendations.


Assuntos
Hipertensão/diagnóstico , Guias de Prática Clínica como Assunto , American Heart Association , Pressão Sanguínea/fisiologia , Humanos , Hipertensão/fisiopatologia , Hipertensão/terapia , América Latina , Estados Unidos
3.
Hum Vaccin Immunother ; 13(5): 1078-1083, 2017 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-28059628

RESUMO

We describe a community-wide outbreak of measles due to a D4 genotype virus that took place in the Region of Madrid, Spain, between February 2011 and August 2012, along with the control measures adopted. The following variables were collected: date of birth, sex, symptoms, complications, hospital admission, laboratory test results, link with another cases, home address, places of work or study, travel during the incubation period, ethnic group, and Mumps-Measles-Rubella (MMR) vaccination status. Incidences were calculated by 100,000 inhabitants. A total of 789 cases were identified. Of all cases, 36.0% belonged to Roma community, among which 68.7% were 16 months to 19 y old. Non-Roma cases were predominantly patients from 6 to 15 months (28.1%) and 20 to 39 y (52.3%). Most cases were unvaccinated. We found out that 3.0% of cases were healthcare workers. The first vaccination dose was brought forward to 12 months, active recruitment of unvaccinated children from 12 months to 4 y of age was performed and the vaccination of healthcare workers and of members of the Roma community was reinforced. High vaccination coverage must be reached with 2 doses of MMR vaccine, aimed at specific groups, such as young adults, Roma population and healthcare workers.


Assuntos
Erradicação de Doenças , Surtos de Doenças , Sarampo/epidemiologia , Adulto , Criança , Pré-Escolar , Controle de Doenças Transmissíveis/métodos , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/etnologia , Infecções Comunitárias Adquiridas/virologia , Surtos de Doenças/prevenção & controle , Feminino , Humanos , Lactente , Masculino , Sarampo/complicações , Sarampo/etnologia , Sarampo/prevenção & controle , Vacina contra Sarampo-Caxumba-Rubéola/administração & dosagem , Morbillivirus/genética , Morbillivirus/isolamento & purificação , Espanha/epidemiologia , Vacinação , Adulto Jovem
4.
J Infect Public Health ; 8(5): 432-40, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25957894

RESUMO

The seroprevalence (SP) of measles and rubella virus antibodies is presented by age groups obtained in the IV Serosurvey of the Region of Madrid (2008-2009). The target population is composed of residents with ages ranging between 2 and 60 years in the Region of Madrid. A two-stage cluster sample is used. The SP of measles virus antibodies is 97.8% (CI 95%: 97.3-98.2). The highest SP is observed in the 2-5 year and 41-60 year age groups. The point estimate does not reach 95% in the 16-20 and 21-30 year age groups. The SP of rubella virus antibodies is 97.2% (CI 95%: 96.5-97.7). The SP is over 95% in all of the age groups. In immigrant women between the ages of 16 and 49, the SP is 95.9% (CI 95%: 93.7-97.4). The identification of groups susceptible to the measles virus in young adults could lead to outbreaks as a result of importing the virus. The circulation of the rubella virus is possible among immigrant women aged between 16 and 49 years, which could lead to the appearance of SRC cases. Epidemiological surveillance will allow the impact on the measles and rubella elimination plan to be determined in the future.


Assuntos
Anticorpos Antivirais/sangue , Vírus do Sarampo/imunologia , Sarampo/epidemiologia , Vírus da Rubéola/imunologia , Rubéola (Sarampo Alemão)/epidemiologia , Adolescente , Adulto , Fatores Etários , Criança , Pré-Escolar , Emigrantes e Imigrantes , Monitoramento Epidemiológico , Feminino , Humanos , Masculino , Sarampo/prevenção & controle , Pessoa de Meia-Idade , Rubéola (Sarampo Alemão)/prevenção & controle , Estudos Soroepidemiológicos , Espanha/epidemiologia , Adulto Jovem
5.
Neurotox Res ; 26(2): 115-29, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24549503

RESUMO

Methamphetamine (METH) causes significant loss of some striatal projection and interneurons. Recently, our group reported on the proliferation of new cells 36 h after METH and some of the new cells survive up to 12 weeks (Tulloch et al., Neuroscience 193:162-169, 2011b). We hypothesized that some of these cells will differentiate and express striatal neuronal phenotypes. To test this hypothesis, mice were injected with METH (30 mg/kg) followed by a single BrdU injection (100 mg/kg) 36 h after METH. One week after METH, a population of BrdU-positive cells expressed the neuronal progenitor markers nestin (18 %) and ß-III-tubulin (30 %). At 8 weeks, 14 % of the BrdU-positive cells were also positive for the mature neuron marker, NeuN. At 12 weeks, approximately 7 % of the BrdU-positive cells co-labeled with ChAT, PV or DARPP-32. We measured motor coordination on the rotarod and psychomotor activity in the open-field. At 12 weeks, METH-injected mice exhibited delayed motor coordination deficits. In contrast, open-field tests revealed that METH-injected mice compared to saline mice displayed psychomotor deficits at 2.5 days but not at 2 or more weeks after METH. Taken together, these data demonstrate that some of the new cells generated in the striatum differentiate and express the phenotypes of striatal neurons. However, the proportion of these new neurons is low compared to the proportion that died by apoptosis 24 h after the METH injection. More studies are needed to determine if the new neurons are functional.


Assuntos
Estimulantes do Sistema Nervoso Central/farmacologia , Corpo Estriado/efeitos dos fármacos , Metanfetamina/farmacologia , Atividade Motora/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Colina O-Acetiltransferase/metabolismo , Corpo Estriado/fisiologia , Proteínas de Ligação a DNA , Fosfoproteína 32 Regulada por cAMP e Dopamina/metabolismo , Comportamento Exploratório/efeitos dos fármacos , Comportamento Exploratório/fisiologia , Masculino , Camundongos Endogâmicos ICR , Atividade Motora/fisiologia , Proteínas do Tecido Nervoso/metabolismo , Nestina/metabolismo , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/fisiologia , Neurogênese/fisiologia , Neurônios/fisiologia , Proteínas Nucleares/metabolismo , Parvalbuminas/metabolismo , Tubulina (Proteína)/metabolismo
6.
Artigo em Inglês | MEDLINE | ID: mdl-24111375

RESUMO

Processing of the long-term ECG Holter recordings for accurate arrhythmia detection is a problem that has been addressed in several approaches. However, there is not an outright method for heartbeat classification able to handle problems such as the large amount of data and highly unbalanced classes. This work introduces a heuristic-search-based clustering to discriminate among ventricular cardiac arrhythmias in Holter recordings. The proposed method is posed under the normalized cut criterion, which iteratively seeks for the nodes to be grouped into the same cluster. Searching procedure is carried out in accordance to the introduced maximum similarity value. Since our approach is unsupervised, a procedure for setting the initial algorithm parameters is proposed by fixing the initial nodes using a kernel density estimator. Results are obtained from MIT/BIH arrhythmia database providing heartbeat labelling. As a result, proposed heuristic-search-based clustering shows an adequate performance, even in the presence of strong unbalanced classes.


Assuntos
Processamento de Sinais Assistido por Computador , Fibrilação Ventricular/diagnóstico , Algoritmos , Inteligência Artificial , Análise por Conglomerados , Eletrocardiografia/métodos , Humanos , Contração Miocárdica , Software
7.
Comput Methods Programs Biomed ; 108(1): 250-61, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22672933

RESUMO

The computer-assisted analysis of biomedical records has become an essential tool in clinical settings. However, current devices provide a growing amount of data that often exceeds the processing capacity of normal computers. As this amount of information rises, new demands for more efficient data extracting methods appear. This paper addresses the task of data mining in physiological records using a feature selection scheme. An unsupervised method based on relevance analysis is described. This scheme uses a least-squares optimization of the input feature matrix in a single iteration. The output of the algorithm is a feature weighting vector. The performance of the method was assessed using a heartbeat clustering test on real ECG records. The quantitative cluster validity measures yielded a correctly classified heartbeat rate of 98.69% (specificity), 85.88% (sensitivity) and 95.04% (general clustering performance), which is even higher than the performance achieved by other similar ECG clustering studies. The number of features was reduced on average from 100 to 18, and the temporal cost was a 43% lower than in previous ECG clustering schemes.


Assuntos
Eletrocardiografia/métodos , Contração Miocárdica , Humanos
8.
Artigo em Inglês | MEDLINE | ID: mdl-23367101

RESUMO

This paper is focused on testing the latency contribution as regards the quality of formed groups for discriminating between healthy and attention deficit hyperactivity disorder children. To this end, two different cases are considered: nonaligned original recordings and aligned signals according to P300 position. For latter case, a novel approach to conduct time location of P300 component is introduced, which is based on derivative of event-related potential signals. The used database holds event-related potentials registered in auditory and visual oddball paradigm. Several experiments are carried out testing both configurations of considered data matrix. For grouping input data matrices, the k-means clustering technique is employed. To assess the quality of formed clusters and the relevance for clustering of latency-based features, relative values of distances between centroids and data points are computed in order to apprise separability and compactness of estimated clusters. Experimental results show that time localization of P300 component is not a decisive feature in formation of compact and well-defined groups within a discrimination framework for two considered data classes under certain conditions.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Encéfalo/fisiopatologia , Diagnóstico por Computador/métodos , Eletroencefalografia/métodos , Potenciais Evocados P300 , Tempo de Reação , Adolescente , Algoritmos , Pré-Escolar , Feminino , Humanos , Masculino , Reconhecimento Automatizado de Padrão/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
9.
Genes Immun ; 12(7): 544-51, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21593779

RESUMO

KIR2DS2 is an activating homologue of KIR2DL2, an inhibitory killer-cell immunoglobulin-like receptor (KIR) that surveys expression of major histocompatibility complex-C allotypes bearing a C1 epitope. We have studied here its allele KIR2DS2*005, which shows a hybrid structure-it is identical to other KIR2DS2 alleles in the ectodomain, but has transmembrane and cytoplasmic regions identical to those of KIR2DS3(*)001, a short-tailed KIR of uncertain expression and function. Our results reveal that KIR2DS2*005 is a fusion gene-the product of an unequal crossing over by which the genes KIR2DS2 and KIR2DS3 recombined within a 400 base pair region of complete identity in intron 6. Also resulting from that recombination was a shortened KIR haplotype of the B group, in which three genes commonly linked to KIR2DS2 (KIR2DL2, KIR2DL5B and KIR2DS3) are deleted. Population studies indicate that KIR2DS2*005 is still associated to such haplotype, and it can be found in approximately 1.2% of Caucasoids. Using a combination of two monoclonal antibodies, we also demonstrate that KIR2DS2*005 encodes a molecule expressed on the surface of natural killer- and T-lymphocytes.


Assuntos
Fusão Gênica , Haplótipos , Receptores KIR/genética , Alelos , Sequência de Bases , Feminino , Regulação da Expressão Gênica , Ordem dos Genes , Humanos , Íntrons , Dados de Sequência Molecular , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Receptores KIR/metabolismo , Alinhamento de Sequência , População Branca/genética
10.
Artigo em Inglês | MEDLINE | ID: mdl-21096570

RESUMO

A method that improves the feature selection stage for non-supervised analysis of Holter ECG signals is presented. The method corresponds to WPCA approach developed mainly in two stages. First, the weighting of the feature set through a weight vector based on M-inner product as distance measure and a quadratic optimization function. The second one is the linear projection of weighted data using principal components. In the clustering stage, some procedures are considered: estimation of the number of groups, initialization of centroids and grouping by means a soft clustering algorithm. In order to decrease the procedure computational cost, segment analysis, grouping contiguous segments and establishing union and exclusion criteria per each cluster, is carried out. This work is focused to classify cardiac arrhythmias into 5 groups, according to the standard of the AAMI (ANSI/AAMI EC57:1998/ 2003). To validate the method, some recordings from MIT/BIH arrhythmia database are used. By employing the labels of each recording, the performance is assessed with supervised measures (Se = 90.1%, Sp = 98.9% y Cp = 97.4%), enhancing other works in the literature that do not take into account all heartbeat types.


Assuntos
Arritmias Cardíacas/diagnóstico , Análise de Componente Principal/métodos , Algoritmos , Arritmias Cardíacas/patologia , Análise por Conglomerados , Frequência Cardíaca , Humanos , Modelos Estatísticos , Distribuição Normal , Reconhecimento Automatizado de Padrão/métodos , Processamento de Sinais Assistido por Computador , Software
11.
Artigo em Inglês | MEDLINE | ID: mdl-19965214

RESUMO

The problem of detecting clinical events related to cardiac arrhythmias in long term electrocardiograms is a difficult one due to the large amount of irrelevant information that hides such events. This problem has been addressed in the literature by means of clustering or classification algorithms that create data partitions according to a cost function based on heartbeat features dissimilarity measures. However, studies about the type or number of heartbeat features is lacking. Usually, the feature sets used are relevant but redundant, which degrades algorithm performance. This paper describes a method for automatic selection of heartbeat features. This method is assessed using real signals from the MIT database and common features used in previous works.


Assuntos
Arritmias Cardíacas/diagnóstico , Frequência Cardíaca , Algoritmos , Engenharia Biomédica/métodos , Análise por Conglomerados , Bases de Dados Factuais , Humanos , Modelos Estatísticos , Redes Neurais de Computação , Distribuição Normal , Reconhecimento Automatizado de Padrão , Processamento de Sinais Assistido por Computador
12.
Genes Immun ; 10(6): 579-85, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19421224

RESUMO

The genetic susceptibility to multiple sclerosis (MS) is only partially explained, and it shows geographic variations. We analyse here two series of Spanish patients and healthy controls and show that relapsing MS (R-MS) is associated with a gene deletion affecting the hypothetically soluble leukocyte immunoglobulin (Ig)-like receptor A3 (LILRA3, 19q13.4), in agreement with an earlier finding in German patients. Our study points to a gene-dose-dependent, protective role for LILRA3, the deletion of which synergizes with HLA-DRB1(*)1501 to increase the risk of R-MS. We also investigated whether the risk of suffering R-MS might be influenced by the genotypic diversity of killer-cell Ig-like receptors (KIRs), located only approximately 400 kb telomeric to LILRA3, and implicated in autoimmunity and defence against viruses. The relationship of LILRA3 deletion with R-MS is not secondary to linkage disequilibrium with a KIR gene, but we cannot exclude some contributions of KIR to the genetic susceptibility to R-MS.


Assuntos
Deleção de Genes , Antígenos HLA-DR/genética , Esclerose Múltipla/genética , Receptores Imunológicos/genética , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Criança , Feminino , Variação Genética , Genótipo , Cadeias HLA-DRB1 , Humanos , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/epidemiologia , Receptores KIR/genética , Espanha/epidemiologia , Adulto Jovem
14.
Genes Immun ; 9(5): 431-7, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18480828

RESUMO

The KIR2DS3 gene is an activating homologue of the inhibitory killer-cell immunoglobulin-like receptors (KIR) that recognize HLA-C molecules, enabling NK cells to survey the normal function of endogenous antigen presentation. The genetics of KIR2DS3 is complicated by the existence of alleles with similar coding sequences that map to different regions of the KIR complex in chromosome 19, or whose location in this complex is unknown. Here, by studying the family segregation of the KIR alleles 2DS3*001, *002 and *003N, and the distribution of these in unrelated individuals, we demonstrate the existence of two paralogous KIR2DS3 genes that can be inherited separately or, as it happens frequently in Caucasoids due to linkage disequilibrium, together. Each KIR2DS3 gene is almost invariably associated in its 5' end to a different copy of KIR2DL5, a gene previously shown to be duplicated in humans. KIR2DL5 and KIR2DS3 thus form two highly homologous gene clusters situated in the centromeric and the telomeric intervals of KIR haplotypes. Recombination between those clusters is the likely origin of new haplotypes, characterized in this study, which harbour further duplications or deletions of multiple KIR genes. Our results help understand the genetics of KIR2DS3 and the diversity of human KIR genotypes.


Assuntos
Variação Genética , Receptores KIR/genética , Duplicação Gênica , Genótipo , Humanos , Mutação , Recombinação Genética
15.
Parasitology ; 133(Pt 4): 453-63, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16817992

RESUMO

Fascioliasis pathogenesis depends on fluke burden. In human hyperendemic zones, individual infection intensities reach very high levels and the majority of infected subjects should be in the advanced chronic phase. The rat model offers a useful approach for pathological research in the advanced chronic period. The influence of infection intensity per rat on fluke development, pre-patent period and egg shedding (eggs/g faeces/worm) was analysed in 3 groups (I: 1-3 worms/rat; II: 4-6; III: 7-9). Ontogenetic trajectories of fluke body measures followed a logistic model. Results showed that when the burden increases, the maximum values of fluke measures decrease. The crowding effect is manifest when fluke measures approximate their maximums in the advanced chronic stage. The pre-patent period and egg production decrease when the burden increases. This means that measurements of eggs per gramme of faeces tend to underestimate the fluke burden. The present study demonstrates how to quantify the fascioliasis experimental rat model crowding effect on adult growth, pre-patent period and egg production. This quantification may be of great interest in epidemiological studies and in experimental research on the in vivo actions of different anthelminthic drugs and vaccines, pathology, immunology and resistance studies.


Assuntos
Fasciola hepatica/fisiologia , Fasciolíase/parasitologia , Modelos Biológicos , Animais , Bolívia , Doença Crônica , Fasciola hepatica/crescimento & desenvolvimento , Fasciola hepatica/patogenicidade , Fezes/parasitologia , Interações Hospedeiro-Parasita , Humanos , Modelos Logísticos , Masculino , Contagem de Ovos de Parasitas , Densidade Demográfica , Distribuição Aleatória , Ratos , Ratos Wistar , Caramujos/parasitologia , Fatores de Tempo
17.
Ecotoxicol Environ Saf ; 55(1): 19-23, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12706389

RESUMO

Cytotoxicity of two insect growth regulators, diflubenzuron, a benzoylphenylurea derivative that inhibits the synthesis of new chitin in target organisms, and pyriproxyfen, an insect juvenile hormone analogue, were tested on CHO-K1 cultures, using the neutral red incorporation assay. Both compounds displayed cytotoxic effects that rise with time exposure. The presence of either fetal calf serum or bovine serum albumin diminished significantly the cytotoxicity of both compounds, thus pointing to a strong protein binding. In addition, extensive metabolization with rat liver submitochondrial fraction gave rise to metabolites less toxic than the parent compounds, implying the relative safety of both diflubenzuron and pyriproxyfen in mammals.


Assuntos
Diflubenzuron/toxicidade , Piridinas/toxicidade , Animais , Células CHO , Cricetinae , Diflubenzuron/metabolismo , Relação Dose-Resposta a Droga , Hormônios Juvenis , Fígado , Mitocôndrias , Ligação Proteica , Piridinas/metabolismo , Ratos
18.
Xenobiotica ; 32(11): 1007-16, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12487730

RESUMO

1. The basal cytotoxic effect of the organochlorine pesticides hexachlorocyclohexane and lindane on CHO-K1 cultures was assessed at fractions of their lethal doses as determined by the neutral red incorporation (NRI) assay (NRI(6.25), NRI(12.5) and NRI(25)). The sulphur-redox cycle enzymes glutathione peroxidase, glutathione reductase and glutathione S-transferase, and total and oxidized glutathione were evaluated at several points during the standard growth curve of the cultures. 2. After incubation with each compound for 24 h, both glutathione peroxidase and reductase showed a substantial increase at the lowest exposure doses (NRI(6.25))--more significantly for lindane than for 1,2,3,4,5,6-hexachlorocyclohexane (HCH)--and dropped at higher doses of both compounds. The reduced and oxidized glutathione content was greatly diminished at the lower exposures, whereas the total glutathione content was higher at NRI(12.5) values. 3. Changes in cell membrane integrity were assessed for a wide range of pesticide concentrations with the lactate dehydrogenase release assay and lipid peroxidation. Membrane leakage and peroxide production were significantly enhanced at concentrations of HCH 50 microg ml(-1), although this effect was not significant at lindane concentrations < 200 microg ml(-1). 4. Lipid peroxidation increased with exposure to HCH at concentrations as low as NRI(6.25), whereas in the case of lindane, this increase was only significant at doses of NRI(25) and above.


Assuntos
Glutationa/metabolismo , Hexaclorocicloexano/química , Hexaclorocicloexano/farmacologia , Animais , Células CHO , Membrana Celular/metabolismo , Cricetinae , Relação Dose-Resposta a Droga , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Indicadores e Reagentes/farmacologia , L-Lactato Desidrogenase/metabolismo , Peroxidação de Lipídeos , Vermelho Neutro/farmacologia , Oxirredução , Estresse Oxidativo , Fatores de Tempo
19.
Comp Biochem Physiol C Toxicol Pharmacol ; 132(3): 365-73, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12161170

RESUMO

The effects of cadmium (Cd(2+)), mercury (Hg(2+)), lead (Pb(2+)), copper (Cu(2+)) and nickel (Ni(2+)) on the glutathione (GSH)-redox cycle were assessed in CHO-K1 by the neutral red uptake inhibition (NR) assay (NR(6.25), NR(12.5) and NR(25)). Mercury proved to be the most and lead the least toxic of the metals tested. The effects on GSH content and intracellular specific activities of enzymes involved in the GSH-redox balance were measured after a 24-h exposure. Total GSH content increased significantly in cultures exposed to the lowest metal concentration assayed (NR(6.25)), but fell to below control values when exposed to concentrations equivalent to NR(25). Oxidised glutathione content dropped significantly at NR(6.25), while somewhat higher values were obtained for cultures exposed to higher doses. Glutathione peroxidase (Gpx) activities were 1.2-, 1.5-, 1.6-, 2.0- and 2.5-fold higher than untreated controls for cadmium, copper, mercury, nickel and lead, respectively, at concentrations equivalent to NR(6.25). Gpx activity declined at metal concentrations equivalent to NR(12.5) and NR(25). Glutathione reductase activity remained almost unchanged except at low doses of mercury, nickel and lead. Glutathione-S-transferase activity decreased at rising metal concentrations. The results suggest that a homeostatic defence mechanism was activated when cells were exposed to doses equivalent to NR(6.25) while the ability of the cells to respond weakened as the dose increased. A close relationship was also observed between metal cytotoxicity, total GSH content and the dissociation energy of the sulphur-metal bonds. These facts confirm the involvement of antioxidant defence mechanisms in the toxic action of these ions.


Assuntos
Glutationa/metabolismo , Metais/farmacologia , Animais , Células CHO , Sobrevivência Celular/efeitos dos fármacos , Corantes , Cricetinae , Relação Dose-Resposta a Droga , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Vermelho Neutro , Oxirredução
20.
Rev. Fac. Odontol. Univ. Antioq ; 13(2): 51-56, ene-.jun. 2002. tab, graf
Artigo em Espanhol | LILACS | ID: lil-347370

RESUMO

Se realizó un estudio de quince autotrasplantes y dos reposiciones dentales en quince pacientes que consultaron, entre agosto de 1994 y junio de 1997 en la Unidad de Cirugía Oral y Estomatología del H.U.S.P. Se evaluaron parámetros clìnicos como dolor, cambio de color, sangrado, movilidad e índice de Russell, también parámetros radiográficos, espacios del ligamento peridontal, reabsorción radicular interna y externa, obliteración de cámara pulpar y estado de desarrollo radicular. Todos los casos realizados fueron de diferentes dientes donantes a diferentes sitios receptores, notándose que los autotrasplantes más frecuentemente realizados son del tercer molar al primer molar y las reposiciones en zona de premolares. La tasa de supervivencia fue de 100 por ciento a los seis meses, y del 75 por ciento a los 12 meses; ésta se mantuvo por los 24 meses. Los resultados finales de este estudio piloto demuestran que los autotrasplantes y las reposiciones dentales son alternativas de tratamiento con alto porcentaje de éxito en caso de pérdida dentaria o alteración en la erupción por malposición


Assuntos
Humanos , Masculino , Adolescente , Adulto , Feminino , Dente , Reimplante Dentário , Distribuição por Idade , Dente Pré-Molar , Colômbia , Unidade Hospitalar de Odontologia , Epidemiologia Descritiva , Estudo de Avaliação , Dente Molar , Dente Serotino , Hemorragia Bucal , Dor Pós-Operatória , Perda de Dente/epidemiologia , Perda de Dente/terapia , Complicações Pós-Operatórias , Estudos Prospectivos , Reabsorção da Raiz/epidemiologia , Reabsorção da Raiz/etiologia , Distribuição por Sexo , Reimplante Dentário
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA