Assuntos
Transplante de Células-Tronco Hematopoéticas , Reação em Cadeia da Polimerase em Tempo Real , Quimeras de Transplante , Adulto , Deleção de Genes , Doença Enxerto-Hospedeiro/diagnóstico , Humanos , Mutação INDEL , Recidiva Local de Neoplasia/diagnóstico , Polimorfismo Genético , Células-Tronco/citologia , Fatores de Tempo , Transplante Homólogo , Resultado do TratamentoRESUMO
Healthy radio-exposed individuals who received low levels of Cesium-137 radiation during the accident that occurred in Goiânia in 1987, their families and controls were tested for the detection of t(14;18)-rearranged B cells in peripheral blood by using a highly sensitive, real-time quantitative PCR method. The chromosomal translocation t(14;18)(q32;q21) is characteristic of follicular lymphoma and is a frequent abnormality observed in other types of non-Hodgkin's lymphoma. This translocation leads to constitutive activation of the BCL2 oncogene by the enhancers of the immunoglobulin heavy-chain locus. In healthy individuals, the same translocation may also be found in a small fraction of peripheral blood lymphocytes, and positive cells might serve as an indicator for environmental exposure to carcinogens and possibly correlate with the cumulative risk of developing t(14;18)- positive non-Hodgkin's lymphoma. Twenty healthy radio-exposed individuals, 10 relatives and 10 non-exposed healthy individuals were tested for the detection of this translocation. Only 1 non-exposed individual was positive for the chromosomal translocation, and healthy radio-exposed individuals presented lower levels of cells bearing the BCL2/J(H) rearrangement when compared to the levels of the patients with follicular lymphoma before treatment. However, evaluation of more cells would be required to confirm the total absence of circulating cells bearing BCL2/J(H) rearrangement.
Assuntos
Radioisótopos de Césio/efeitos adversos , Genes bcl-2 , Liberação Nociva de Radioativos , Translocação Genética/efeitos da radiação , Adulto , Linfócitos B/efeitos da radiação , Brasil , Linhagem Celular , Cromossomos Humanos Par 14/efeitos da radiação , Cromossomos Humanos Par 18/efeitos da radiação , Exposição Ambiental/efeitos adversos , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Linfoma Folicular/etiologia , Linfoma Folicular/genética , Linfoma não Hodgkin/etiologia , Linfoma não Hodgkin/genética , Neoplasias Induzidas por Radiação/etiologia , Neoplasias Induzidas por Radiação/genéticaRESUMO
The interaction of acute lymphoblastic leukemia (ALL) blasts with bone marrow (BM) stromal cells (BMSCs) has a positive impact on ALL resistance to chemotherapy. We investigated the modulation of a series of putative asparaginase-resistance/sensitivity genes in B-precursor ALL cells upon coculture with BMSCs. Coculture with stromal cells resulted in increased insulin-like growth factor (IGF)-binding protein 7 (IGFBP7) expression by ALL cells. Assays with IGFBP7 knockdown ALL and stromal cell lines, or with addition of recombinant rIGFBP7 (rIGFBP7) to the culture medium, showed that IGFBP7 acts as a positive regulator of ALL and stromal cells growth, and significantly enhances in-vitro resistance of ALL to asparaginase. In these assays, IGFBP7 function occurred mainly in an insulin- and stromal-dependent manner. ALL cells were found to contribute substantially to extracellular IGFBP7 levels in the conditioned coculture medium. Diagnostic BM plasma from children with ALL had higher levels of IGFBP7 than controls. IGFBP7, in an insulin/IGF-dependent manner, enhanced asparagine synthetase expression and asparagine secretion by BMSCs, thus providing a stromal-dependent mechanism by which IGFBP7 protects ALL cells against asparaginase in this coculture system. Importantly, higher IGFBP7 mRNA levels were associated with lower leukemia-free survival (Cox regression model, P=0.003) in precursor B-cell Ph(-) ALL patients (n=147) treated with a contemporary polychemotherapy protocol.
Assuntos
Asparaginase/farmacologia , Células da Medula Óssea/patologia , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/fisiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Células Estromais/patologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Técnicas de Cocultura , Meios de Cultivo Condicionados , Resistencia a Medicamentos Antineoplásicos , Feminino , Citometria de Fluxo , Técnicas de Silenciamento de Genes , Humanos , Lactente , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/genética , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/metabolismo , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , RNA Interferente Pequeno , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
Interleukin 7 (IL-7) and its receptor, formed by IL-7Rα (encoded by IL7R) and γc, are essential for normal T-cell development and homeostasis. Here we show that IL7R is an oncogene mutated in T-cell acute lymphoblastic leukemia (T-ALL). We find that 9% of individuals with T-ALL have somatic gain-of-function IL7R exon 6 mutations. In most cases, these IL7R mutations introduce an unpaired cysteine in the extracellular juxtamembrane-transmembrane region and promote de novo formation of intermolecular disulfide bonds between mutant IL-7Rα subunits, thereby driving constitutive signaling via JAK1 and independently of IL-7, γc or JAK3. IL7R mutations induce a gene expression profile partially resembling that provoked by IL-7 and are enriched in the T-ALL subgroup comprising TLX3 rearranged and HOXA deregulated cases. Notably, IL7R mutations promote cell transformation and tumor formation. Overall, our findings indicate that IL7R mutational activation is involved in human T-cell leukemogenesis, paving the way for therapeutic targeting of IL-7R-mediated signaling in T-ALL.
Assuntos
Oncogenes , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Receptores de Interleucina-7/genética , Transdução de Sinais , Animais , Ciclo Celular , Linhagem Celular , Sobrevivência Celular , Criança , Cisteína/genética , Cisteína/metabolismo , Análise Mutacional de DNA , Éxons , Perfilação da Expressão Gênica , Regulação Leucêmica da Expressão Gênica , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Interleucina-7/genética , Interleucina-7/metabolismo , Janus Quinase 1/genética , Janus Quinase 1/metabolismo , Janus Quinase 3/genética , Janus Quinase 3/metabolismo , Camundongos , Camundongos Knockout , Mutação , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Receptores de Interleucina-7/metabolismo , Análise de Sequência de DNA , Linfócitos T/metabolismo , Transfecção , Células Tumorais CultivadasRESUMO
Oxidative stress induced by microcystins was evaluated in an estuarine worm, Laeonereis acuta (Nereididae). Ten organisms were exposed to lyophilized cells of a toxic Microcystisaeruginosa strain RST9501 ( approximately 2 microg/mL microcystins, MC); 10 were exposed to lyophilized cells of a nontoxic Aphanotece sp. strain RSMan92 and 10 were maintained without cyanobacterial cells. Exposure time was 48 h. The enzymatic antioxidant defenses, as well as the oxidative damage, were analyzed. Toxic and nontoxic cyanobacteria lowered catalase activity with no changes in glutathione reductase and glutathione-S-transferase activities. This may have led to toxin intracellular accumulation, which should favor oxidative stress generation, observed by the high lipid peroxide and DNA-protein crosslink levels in the group exposed to MC.
Assuntos
Toxinas Marinhas/toxicidade , Microcistinas/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Poliquetos/efeitos dos fármacos , Animais , Microcystis/química , Poliquetos/enzimologiaRESUMO
The present study compares two computer models of the first part of glucose catabolism in different organisms in search of evolutionarily conserved characteristics of the glycolysis cycle and proposes the main parameters that define the stable steady-state or oscillatory behavior of the glycolytic system. It is suggested that in both human pancreatic beta-cells and Saccharomyces cerevisiae there are oscillations that, despite differences in wave form and period of oscillation, share the same robustness strategy: the oscillation is not controlled by only one but by at least two parameters that will have more or less control over the pathway flux depending on the initial state of the system as well as on extra-cellular conditions. This observation leads to two important interpretations: the first is that in both S. cerevisiae and human beta-cells, despite differences in enzyme kinetics and mechanism of feedback control, evolution seems to have kept an oscillatory behavior coupled to the glucose concentration outside the cytoplasm, and the second is that the development of drugs to regulate metabolic dysfunctions in more complex systems may require further study, not only determining which enzyme is controlling the flux of the system but also under which conditions and how its control is maintained by the enzyme or transferred to other enzymes in the pathway as the drug starts acting.
Assuntos
Glicólise , Células Secretoras de Insulina/metabolismo , Saccharomyces cerevisiae/metabolismo , Simulação por Computador , Ativação Enzimática , Glucoquinase/metabolismo , Glucose/metabolismo , Humanos , Células Secretoras de Insulina/enzimologia , Cinética , Modelos Biológicos , Oscilometria , Fosfofrutoquinases/metabolismo , Saccharomyces cerevisiae/enzimologiaRESUMO
The interpretation of oligonucleotide array experiments depends on the quality of the target cRNA used. cRNA target quality is assessed by quantitative analysis of the representation of 5' and 3' sequences of control genes using commercially available Test arrays. The Test array provides an economically priced means of determining the quality of labeled target prior to analysis on whole genome expression arrays. This manuscript validates the use of a duplex RT-PCR assay as a faster (6 h) and less expensive (<10 US dollars) but equally accurate alternative to the Test arrays in determining biotinylated cRNA quality. Forty-one different cRNA samples were hybridized to HG-U133A microarrays from Affymetrix. Ten cRNA samples with a beta-actin 3'/5' ratio >6 were chosen and classified as degraded cRNAs, and 31 samples with a beta-actin 3'/5' ratio <6 were selected as good quality cRNAs. Blinded samples were then used for the RT-PCR assay. After gel electrophoresis, optical densities of the amplified 3' and 5' fragments of beta-actin were measured and the 3'/5' ratio was calculated. There was a strong correlation (r(2) = 0.6802) between the array and the RT-PCR beta-actin 3'/5' ratios. Moreover, the RT-PCR 3'/5' ratio was significantly different (P < 0.0001) between undegraded (mean +/- SD, 0.34 +/- 0.09) and degraded (1.71 +/- 0.83) samples. None of the other parameters analyzed, such as i) the starting amount of RNA, ii) RNA quality assessed using the Bioanalyzer Chip technology, or iii) the concentration and OD260/OD280 ratio of the purified biotinylated cRNA, correlated with cRNA quality.
Assuntos
Análise de Sequência com Séries de Oligonucleotídeos/métodos , RNA Complementar/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Biotinilação , HumanosRESUMO
The interpretation of oligonucleotide array experiments depends on the quality of the target cRNA used. cRNA target quality is assessed by quantitative analysis of the representation of 5' and 3' sequences of control genes using commercially available Test arrays. The Test array provides an economically priced means of determining the quality of labeled target prior to analysis on whole genome expression arrays. This manuscript validates the use of a duplex RT-PCR assay as a faster (6 h) and less expensive (
Assuntos
Humanos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , RNA Complementar/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , BiotinilaçãoRESUMO
Microcystins produced by cyanobacteria are potent inhibitors of some protein phosphatases, but recent evidence also indicates its potential to generate oxidative stress. In the present study, the effects of microcystin raw extracts (Mic; 0.01 and 20microg/L) and purified okadaic acid (OA; 0.01 and 10microg/L) on short- and long-term memory alteration and antioxidant and oxidative damage were investigated in hippocampus of rats. The results showed an amnesic effect with 0.01 and 20microg/L Mic on retrieval and only with 0.01microg/L Mic on spatial learning. Parallel to these effects oxidative damage was observed as evidenced by augmented levels of lipid peroxides and DNA damage and the absence of antioxidant responses in terms of total oxyradical scavenging capacity. Phase II reactions catalyzed by glutathione-S-transferase were not modified after microcystins exposure. Overall this study showed physiological events (retrieval and spatial learning) that can be related to the classical toxic effects of microcystins (i.e., phosphatase inhibition). In addition, evidence of alternative toxicity mechanisms via oxidative stress generation was also obtained. The fact that organic anion transporter polypeptides (OATP) involved in microcystins uptake are expressed not only in liver but also in brain points to the environmental relevance of the observed effects.
Assuntos
Hipocampo/efeitos dos fármacos , Hipocampo/fisiologia , Memória de Curto Prazo/efeitos dos fármacos , Memória/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Peptídeos Cíclicos/farmacologia , Animais , Hipocampo/metabolismo , Memória/fisiologia , Memória de Curto Prazo/fisiologia , Microcistinas , Ácido Okadáico/farmacologia , Ratos , Ratos Wistar , Fatores de TempoRESUMO
Microcystins are usually the predominant cyanotoxins present in both drinking and recreational waters after cyanobacterial blooms. Their classic toxic effect is hepatotoxicity through inhibition of serine/threonine phosphatases. However, recent studies also reported oxidative stress generation and disruption of ion regulation in aquatic organisms after microcystins exposure. In the present study, aqueous extracts of Microcystis aeruginosa were administered to the estuarine crab Chasmagnathus granulatus (Decapoda, Brachyura) by gavage in variable doses (from 34 to 860 microg kg(-1)) and exposure times (6, 12, and 72 h). A control group was exposed to saline solution. Analyzed variables included oxygen consumption, lipid peroxidation (LPO), enzyme activities (glutathione S-transferases or GST; alanine aminotransferase or ALT; aspartate aminotransferase or AST; and lactate dehydrogenase or LDH), glycogen, and microcystins content. Oxygen consumption increased in organisms exposed for 12h to 860 microg kg(-1) of microcystins and a similar result was observed after 72 h at doses equal to or higher than 34 microg kg(-1). LPO levels increased in doses equal to or higher than 34 microg kg(-1) after 72 h. GST and LDH activities increased after 12 h (at a dose of 860 microg kg(-1)), but ALT and AST activities remained unaltered in all experimental conditions. Glycogen content decreased after 72 h exposure at doses equal to or higher than 172 microg kg(-1). After 12h of exposure to 860 microg kg(-1) of microcystins, the concentration found in the hepatopancreas of C. granulatus was 13.17+/-0.56 microg kg(-1). In crabs exposed to doses higher than 172 microg kg(-1) during 72 h this value raised to 32.14+/-4.12 microg kg(-1). The obtained results indicated that microcystins exposure led the tissue to an oxidative stress condition (high LPO levels), at least in part favored by the augment of oxygen consumption, altering the glycogen metabolism. GST responses were only observed in the short-term experiment (12 h) and no effect on classical markers of vertebrate liver damage (ALT and AST) was observed. Although the hepatopancreas from C. granulatus accumulated a relatively low concentration of toxins, it was enough to induce physiological and biochemical disturbances.
Assuntos
Braquiúros , Microcistinas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Braquiúros/efeitos dos fármacos , Braquiúros/enzimologia , Braquiúros/metabolismo , Braquiúros/fisiologia , Relação Dose-Resposta a Droga , Hepatopâncreas/efeitos dos fármacos , Hepatopâncreas/enzimologia , Hepatopâncreas/metabolismo , Peróxidos Lipídicos/metabolismo , Masculino , Microcistinas/farmacocinética , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/farmacocinéticaRESUMO
The present study compares two computer models of the first part of glucose catabolism in different organisms in search of evolutionarily conserved characteristics of the glycolysis cycle and proposes the main parameters that define the stable steady-state or oscillatory behavior of the glycolytic system. It is suggested that in both human pancreatic b-cells and Saccharomyces cerevisiae there are oscillations that, despite differences in wave form and period of oscillation, share the same robustness strategy: the oscillation is not controlled by only one but by at least two parameters that will have more or less control over the pathway flux depending on the initial state of the system as well as on extra-cellular conditions. This observation leads to two important interpretations: the first is that in both S. cerevisiae and human b-cells, despite differences in enzyme kinetics and mechanism of feedback control, evolution seems to have kept an oscillatory behavior coupled to the glucose concentration outside the cytoplasm, and the second is that the development of drugs to regulate metabolic dysfunctions in more complex systems may require further study, not only determining which enzyme is controlling the flux of the system but also under which conditions and how its control is maintained by the enzyme or transferred to other enzymes in the pathway as the drug starts acting.
Assuntos
Humanos , Glicólise , Células Secretoras de Insulina/metabolismo , Saccharomyces cerevisiae/metabolismo , Simulação por Computador , Ativação Enzimática , Glucoquinase/metabolismo , Glucose/metabolismo , Células Secretoras de Insulina/enzimologia , Cinética , Modelos Biológicos , Oscilometria , Fosfofrutoquinases/metabolismo , Saccharomyces cerevisiae/enzimologiaRESUMO
Antioxidant responses and oxidative stress were evaluated in the hepatopancreas of the estuarine crab Chasmagnathus granulatus (Decapoda, Brachyura) after oral microcystin administration. Responses were evaluated through antioxidant enzyme activities (catalase-(CAT), superoxide dismutase, glutathione-S-transferase- (GST)). Nonproteic sulfhydril (NP-SH) groups, oxygen consumption, lipid peroxides (LPO), and oxidized proteins were also measured. Microcystin administration increased the oxygen consumption. GST activity and NP-SH concentration showed transient increases and CAT activity showed a peak and then a reduction. Oxidative damage was evidenced with regard to LPO content and suggested by the inhibition of CAT activity at the end of the experiment, indicating that the antioxidant response induced by the toxin was insufficient. A lowering in the number of hepatopancreatic B cells should be related to microcystin elimination.
Assuntos
Antioxidantes/fisiologia , Braquiúros/fisiologia , Inibidores Enzimáticos/toxicidade , Hepatopâncreas/fisiologia , Estresse Oxidativo , Peptídeos Cíclicos/toxicidade , Animais , Glutationa Transferase/metabolismo , Microcistinas , Consumo de OxigênioRESUMO
Microcystins are hepatotoxins suspected to generate oxidative stress. This mechanism was evaluated in gills of the estuarine crab Chasmagnathus granulatus (Decapoda, Brachyura). Adult male crabs were fed ground beef with or without vitamin E (600 mg/kg). Microcystin (1.21 microg/kg) was daily administered through forced ingestion, for 7 days. After exposure, catalase activity was reduced in posterior gills of crabs supplemented with vitamin E. A lower increment in glutathione S-transferase activity (GST) was observed in organisms pretreated with vitamin E and then exposed to microcystin with respect to those exposed to the toxin but not pretreated with the vitamin. Pretreatment with vitamin E also increased nonproteic sulfhyrdil groups and this effect was not observed after microcystin exposure. The fact that supplementation with antioxidants such as vitamin E modulates GST activity indicates the direct or indirect involvement of microcystin in oxidative stress generation.
Assuntos
Antioxidantes/farmacologia , Antioxidantes/fisiologia , Braquiúros/fisiologia , Peptídeos Cíclicos/toxicidade , Vitamina E/farmacologia , Animais , Exposição Ambiental , Brânquias/fisiologia , Glutationa Transferase/metabolismo , MicrocistinasRESUMO
Toxic blooms of the cyanobacterium Microcystis aeruginosa, a microcystin producer, have been observed in the past two decades in the Patos Lagoon estuary (southern Brazil). This cyanobacterium reaches the estuary from northern waters and accumulates as toxic blooms in the shallow margins of the environment. Microcystins are phosphatase (PP1 and PP2A) inhibitors and cause animal death via alteration of the liver cell cytoskeletons and intrahepatic hemorrhage. The massive accumulation of toxic material affects the survival of several benthonic estuarine local organisms. The tanaidacea Kalliapseudes schubartii is a benthonic estuarine species which occurs at high densities throughout the year in mixohaline areas of the Patos Lagoon. This microcrustacean is of high ecological relevance and plays an important role in the estuarine food web, as it is consumed on a large scale by estuarine fish. This work verifies the acute toxicity of aqueous extracts of M. aeruginosa RST9501 and of sediments spiked with lyophilized material of the same strain on K. schubartii; it also evaluates the sublethal effects on tanaidacean oxygen consumption rates and glycogen levels under acute exposure to M. aeruginosa aqueous extracts. The strain M. aeruginosa RST9501 was cultured in BGN/2 medium. The aqueous extracts were prepared using the lyophilized material from the strain cultures. Acute tests were performed over 96 h at a salinity of 15, at six toxic concentrations, and resulted in an average 96-h LC50 of 1.44 mg ml(-1). The spiked sediment tests were performed with a 10-day duration, using the lyophilized material in three proportions of powder/sediment and showed an average LC50 of 1.79 mg ml(-1). Oxygen consumption was determined after 24 and 48 h of incubation in adult organisms exposed to sublethal aqueous extract concentrations and showed a significant increase at the highest concentrations. This suggests alterations in the organism's metabolism by exposure to the cyanobacterium extract. The glycogen levels were determined with a commercial kit (Glicox 500; DOLES Ltd.); after 24 and 48 h the dosages were administered in the same organisms utilized in the oxygen consumption test and did not demonstrate significant differences. The results demonstrate the possible risks of intoxication to which the natural populations of K. schubartii were exposed in the environment and emphasize the importance of studies involving sublethal concentrations of M. aeruginosa to other organisms of the trophic web in this aquatic system.
Assuntos
Toxinas Bacterianas/toxicidade , Crustáceos/efeitos dos fármacos , Microcystis/química , Peptídeos Cíclicos/toxicidade , Animais , Toxinas Bacterianas/isolamento & purificação , Brasil , Sedimentos Geológicos/química , Glicogênio/metabolismo , Dose Letal Mediana , Microcistinas , Oceanos e Mares , Oxigênio/metabolismo , Peptídeos Cíclicos/isolamento & purificação , Testes de Toxicidade AgudaRESUMO
Microcystins are toxins produced by cyanobacteria, being toxic to aquatic fauna. It was evaluated alternative mechanisms of microcystins toxicity, including oxidative stress and histopathology in the hepatopancreas of the estuarine crab Chasmagnathus granulatus (Decapoda, Grapsidae). Microcystins was administered to crabs (MIC group) over 1 week, whereas the control (CTR group) received the saline from cyanobacteria culture medium. At day 7, catalase activity was higher in the MIC than in the CTR group, although a decrease of activity was verified in both groups with respect to time 0. Glutathione-S-transferase activity augmented in MIC with respect to CTR, suggesting a higher conjugation rate of the toxins with glutathione. No differences were detected in the superoxide dismutase activity. Lipid peroxidation remained stable in both groups. Histopathological analyses showed that the number of B cells decreased significantly in the CTR as a possible effect of starvation, while no significant change was observed in the MIC group. The hepatopancreas from the MIC group exhibited some necrotic tubules and melanin-like deposits. Overall, results showed that some enzymes of the antioxidant defense system were activated after microcystins exposure, this response being able to maintain lipid peroxidation levels, but insufficient to completely prevent histological damage.
Assuntos
Toxinas Bacterianas/toxicidade , Decápodes/efeitos dos fármacos , Hepatopâncreas/efeitos dos fármacos , Peptídeos Cíclicos/toxicidade , Animais , Catalase/metabolismo , Cianobactérias/química , Glutationa Transferase/metabolismo , Hepatopâncreas/metabolismo , Hepatopâncreas/patologia , Hepatopâncreas/ultraestrutura , Histocitoquímica , Peróxidos Lipídicos/metabolismo , Masculino , Melaninas/metabolismo , Microcistinas , Necrose , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/metabolismoRESUMO
PURPOSE: To investigate the presence of human papillomavirus (HPV) DNA in tumour tissue from patients with unilateral retinoblastoma. METHODS: Samples of paraffin-embedded tumour tissue from 43 children with unilateral retinoblastoma were collected to investigate the presence of HPV DNA using polymerase chain reaction (PCR) and dot blot hybridization. RESULTS: Oncogenic HPV DNA types 16 and 35 were detected in 12 (27.9%) of 43 tumour specimens. A higher frequency of differentiated tumours (63.3%) was observed among the HPV-positive tumours. CONCLUSIONS: Future studies are necessary to demonstrate an association between HPV and sporadic retinoblastoma.
Assuntos
Papillomaviridae/isolamento & purificação , Neoplasias da Retina/virologia , Retinoblastoma/virologia , Pré-Escolar , DNA Viral/análise , Enucleação Ocular , Feminino , Humanos , Hibridização In Situ , Lactente , Masculino , Papillomaviridae/genética , Inclusão em Parafina , Reação em Cadeia da Polimerase , Neoplasias da Retina/patologia , Neoplasias da Retina/cirurgia , Retinoblastoma/patologia , Retinoblastoma/cirurgia , Proteínas Virais/análiseRESUMO
The objective of this work was to evaluate mechanisms of microcystin toxicity on crustacean species. Adult male crabs of Chasmagnathus granulatus (13.97+/-0.35 g) acclimated to low salinity (2 per thousand ) were injected with saline (control) or Microcystis aeruginosa aqueous extract (39.2 microg/l) at 24 h intervals for 48 h. After the exposure period, the anterior and posterior gills were dissected, measuring Na(+),K(+)-ATPase and glutathione-S-transferase (GST) activity. Total oxyradical scavenging capacity (TOSC) and lipid peroxides (LPO) content were also determined. Na(+),K(+)-ATPase activity in anterior gills was significantly lower in crabs injected with toxin than in control crabs, while no significant difference in the enzyme activity was detected in posterior gills. Both sodium and chloride concentration in the hemolymph were not affected by toxin exposure. Significant changes in GST activity were detected in posterior gills, with higher values being observed in the toxin-injected crabs. Crabs exposed to microcystin also showed a significant increase in the TOSC value against peroxyl radicals, for both anterior and posterior gills. Lipid peroxides level did not change in both gill types after exposure to the toxin. The increased levels of TOSC suggest the occurrence of a crab response against oxidative stress induced by toxin injection, which prevents lipid peroxidation.
Assuntos
Antioxidantes/metabolismo , Decápodes/fisiologia , Brânquias/efeitos dos fármacos , Canais Iônicos/efeitos dos fármacos , Peptídeos Cíclicos/toxicidade , Animais , Sequestradores de Radicais Livres/metabolismo , Brânquias/enzimologia , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Microcistinas , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismoRESUMO
Los quistes del rafe medio representan defectos del desarrollo embriológico de la zona genitc cuentran tapizados por diferentes epitelios según su ubicación. Estas lesiones, que son más comúnmente hall ca del meato uretral, pueden localizarse en cualquier lugar del rafe medio genitoperineal, desde el glandi ano. El tratamiento de elección es la escisión quirúrgica. Presentamos tres nuevos casos y revisamos la literatura. (AU)
Assuntos
Humanos , Masculino , Adolescente , Adulto , Criança , Cistos/cirurgia , Cistos/embriologia , Cistos/terapia , Genitália Masculina/anormalidades , Genitália Masculina/cirurgia , Diagnóstico DiferencialRESUMO
Los quistes del rafe medio representan defectos del desarrollo embriológico de la zona genitc cuentran tapizados por diferentes epitelios según su ubicación. Estas lesiones, que son más comúnmente hall ca del meato uretral, pueden localizarse en cualquier lugar del rafe medio genitoperineal, desde el glandi ano. El tratamiento de elección es la escisión quirúrgica. Presentamos tres nuevos casos y revisamos la literatura.
Assuntos
Humanos , Masculino , Adolescente , Adulto , Criança , Cistos , Genitália Masculina , Diagnóstico DiferencialRESUMO
Recent discoveries indicate that microcystins affect enzymes, such as Na(+),K(+)-ATPase, involved in ion regulation of aquatic animals, through K(+)-dependent phosphatase inhibition. In vitro studies showed the inhibitory effect of Microcystis aeruginosa extracts on Na(+),K(+)-ATPase and K(+)-dependent phosphatase activities in gills of Chasmagnathus granulata (Decapoda, Grapsidae). Extracts of M. aeruginosa were prepared from lyophilized or cultures cells of the cyanobacterium. For lyophilized cells, IC(50) values were estimated as 0.46 microg/L (95% confidence interval [CI]=0.40-0.52 microg/L) and 1.31 microg/L (95% CI=1.14-1.51 microg/L) for Na(+),K(+)-ATPase and K(+)-dependent phosphatase, respectively. However, extracts prepared from cultured cells presented a much lower inhibitory potency against both enzymes. Gas chromatography revealed long-chain fatty acids in the lyophilized cell extracts, indicating that they are in part responsible for the enzyme inhibition. In vivo studies showed that the toxin inhibited Na(+),K(+)-ATPase activity in anterior gills, whereas an increased augmented activity of glutathione-S-transferase was observed in both kind of gills, indicating that the crab has increased its ability to conjugate the toxin. No significant differences in hemolymph sodium or chloride concentration were detected. This result is in agreement with the lack of effects of microcystin on Na(+),K(+)-ATPase activity of posterior (osmoregulating) gills.