RESUMO
The number of studies that use the common marmoset (Callithrix jacchus) in various fields of neurosciences is increasing dramatically. In general, animals enter the study when their health status is considered satisfactory on the basis of classical clinical investigations. In behavioral studies, variations of score between individuals are frequently observed, some of them being considered as poor performers or outliers. Experimenters rarely consider the fact that it could be related to some brain anomaly. This raises the important issue of the reliability of such classical behavioral approaches without using complementary imaging, especially in animals lacking striking external clinical signs. Here we report the case of a young marmoset which presented a set of cognitive impairments in two different tasks compared to other age-matched animals. Brain imaging revealed a patent right lateral ventricular enlargement with a mild hippocampal atrophy. This abnormality could explain the cognitive impairments of this animal. Such a case points to the importance of complementing behavioral studies by imaging explorations to avoid experimental bias.
Assuntos
Atrofia/patologia , Transtornos Cognitivos/patologia , Hipocampo/patologia , Animais , Atrofia/metabolismo , Comportamento Animal , Encéfalo/diagnóstico por imagem , Callithrix , Feminino , Imageamento por Ressonância Magnética , Masculino , Estimulação Luminosa , RadiografiaRESUMO
Resin infiltration has made possible an innovative way of treating initial carious lesions that fits perfectly with the concept of minimal intervention dentistry. Infiltration of carious lesions represents a new approach to the treatment of non-cavitated lesions of proximal and smooth surfaces of deciduous and permanent teeth. The major advantage of this method is that it is a non-invasive treatment, preserving tooth structure and that it can be achieved in a single visit. While this therapy can rightly be categorised as minimum intervention dentistry, clinical experience is limited and further controlled clinical trials are required to assess its long-term results. The inhibition of caries progression by resin infiltration should now be considered an alternative to invasive restorations, but involves early detection of lesions and does not allow for appropriate monitoring of the caries risk.
Assuntos
Cárie Dentária/prevenção & controle , Selantes de Fossas e Fissuras/uso terapêutico , Resinas Sintéticas/uso terapêutico , Condicionamento Ácido do Dente/métodos , Adolescente , Adulto , Criança , Cárie Dentária/classificação , Cárie Dentária/terapia , Esmalte Dentário/patologia , Progressão da Doença , Diagnóstico Precoce , Feminino , Humanos , Cura Luminosa de Adesivos Dentários , Polimerização , Medição de Risco , Desmineralização do Dente/terapia , Dente Decíduo/patologiaRESUMO
The detection of carious lesions is focused on the identification of early mineral changes to allow the demineralisation process to be managed by non-invasive interventions. The methods recommended for clinical diagnosis of initial carious lesions are discussed and illustrated. These include the early detection of lesions, evaluation of the extent of the lesion and its state of activity and the establishment of appropriate monitoring. The place of modern tools, including those based on fluorescence, is discussed. These can help inform patients. They are also potentially useful in regular control visits to monitor the progression or regression of early lesions. A rigorous and systematic approach to caries diagnosis is essential to establish a care plan for the disease and to identify preventive measures based on more precise diagnosis and to reduce reliance on restorative measures.
Assuntos
Cárie Dentária/diagnóstico , Adulto , Dente Pré-Molar/patologia , Cárie Dentária/prevenção & controle , Testes de Atividade de Cárie Dentária , Suscetibilidade à Cárie Dentária , Placa Dentária/diagnóstico , Progressão da Doença , Diagnóstico Precoce , Feminino , Fluorescência , Hemorragia Gengival/diagnóstico , Humanos , Lasers , Dispositivos Ópticos , Planejamento de Assistência ao Paciente , Exame Físico , Radiografia Interproximal , Medição de Risco , Fatores de Risco , Desmineralização do Dente/diagnóstico , Remineralização DentáriaRESUMO
BACKGROUND: Non-cirrhotic portal hypertension of unknown cause is a poorly understood condition attributed to obstructive portal venopathy. AIM: To reassess the manifestations, course, and causes, with special attention to thrombosis. METHODS: Analysis of a cohort of 28 patients. RESULTS: Gastrointestinal bleeding occurred in 11 patients. Liver failure developed at the time of concurrent disease in eight patients, including all four patients who died. Portal vein thrombosis developed in 13 patients. A prothrombotic disorder was found in 12 of 23 fully investigated patients. Hepatoportal sclerosis was observed in 11 patients (with associated perisinusoidal fibrosis and/or nodular regenerative hyperplasia in six); periportal fibrosis, perisinusoidal fibrosis, nodular regenerative hyperplasia, or a combination thereof were observed in other patients. A morphometric evaluation showed an increased number of portal vessels in patients with hepatoportal sclerosis. There was no relation between pathological results and haemodynamic findings or prothrombotic disorders. CONCLUSIONS: Outcome was related to associated conditions. Overlap in pathological, haemodynamic, and causal features suggests a single entity, with prothrombotic disorders as major causal factors, and injury to sinusoids as well as to portal venules as the primary mechanism. Activated coagulation could mediate vascular injury in the absence of thrombosis. Anticoagulation should be considered.
Assuntos
Hipertensão Portal/patologia , Fígado/patologia , Adulto , Feminino , Seguimentos , Hemorragia Gastrointestinal/etiologia , Humanos , Hipertensão Portal/diagnóstico por imagem , Fígado/diagnóstico por imagem , Cirrose Hepática , Masculino , Veia Porta , Radiografia , Esclerose , Trombose/patologia , UltrassonografiaAssuntos
Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/imunologia , Eosinofilia/etiologia , Interleucina-5/biossíntese , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/imunologia , Síndromes Paraneoplásicas/etiologia , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Carcinoma Hepatocelular/patologia , Eosinofilia/imunologia , Humanos , Neoplasias Hepáticas/patologia , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/patologia , Masculino , Pessoa de Meia-Idade , Síndromes Paraneoplásicas/imunologiaRESUMO
The Cockayne syndrome B protein (CSB) is required for coupling DNA excision repair to transcription in a process known as transcription-coupled repair (TCR). Cockayne syndrome patients show UV sensitivity and severe neurodevelopmental abnormalities. CSB is a DNA-dependent ATPase of the SWI2/SNF2 family. SWI2/SNF2-like proteins are implicated in chromatin remodeling during transcription. Since chromatin structure also affects DNA repair efficiency, chromatin remodeling activities within repair are expected. Here we used purified recombinant CSB protein to investigate whether it can remodel chromatin in vitro. We show that binding of CSB to DNA results in an alteration of the DNA double-helix conformation. In addition, we find that CSB is able to remodel chromatin structure at the expense of ATP hydrolysis. Specifically, CSB can alter DNase I accessibility to reconstituted mononucleosome cores and disarrange an array of nucleosomes regularly spaced on plasmid DNA. In addition, we show that CSB interacts not only with double-stranded DNA but also directly with core histones. Finally, intact histone tails play an important role in CSB remodeling. CSB is the first repair protein found to play a direct role in modulating nucleosome structure. The relevance of this finding to the interplay between transcription and repair is discussed.
Assuntos
Trifosfato de Adenosina/metabolismo , Cromatina/metabolismo , DNA Helicases/metabolismo , Reparo do DNA , Proteínas Nucleares , Conformação de Ácido Nucleico , Transcrição Gênica , Animais , Extratos Celulares , Cromatina/química , Cromatina/genética , Síndrome de Cockayne/genética , DNA Helicases/genética , Enzimas Reparadoras do DNA , DNA Super-Helicoidal/química , DNA Super-Helicoidal/genética , DNA Super-Helicoidal/metabolismo , Proteínas de Ligação a DNA/metabolismo , Desoxirribonuclease I/metabolismo , Drosophila melanogaster/citologia , Drosophila melanogaster/embriologia , Regulação da Expressão Gênica , Células HeLa , Histonas/química , Histonas/metabolismo , Humanos , Modelos Genéticos , Mutação , Nucleossomos/química , Nucleossomos/genética , Nucleossomos/metabolismo , Plasmídeos/química , Plasmídeos/genética , Plasmídeos/metabolismo , Proteínas de Ligação a Poli-ADP-Ribose , Proteínas Recombinantes de Fusão , Fatores de Transcrição/metabolismo , Tripsina/metabolismoAssuntos
Dor Abdominal/etiologia , Coristoma/complicações , Coristoma/diagnóstico , Mesentério , Pâncreas , Pancreatite/complicações , Pancreatite/diagnóstico , Doenças Peritoneais/complicações , Doenças Peritoneais/diagnóstico , Doença Aguda , Adulto , Biópsia , Coristoma/cirurgia , Humanos , Masculino , Doenças Peritoneais/cirurgia , Tomografia Computadorizada por Raios XRESUMO
ATP-dependent chromatin remodeling enzymes antagonize the inhibitory effects of chromatin. We compare six different remodeling complexes: ySWI/SNF, yRSC, hSWI/SNF, xMi-2, dCHRAC, and dNURF. We find that each complex uses similar amounts of ATP to remodel nucleosomal arrays at nearly identical rates. We also perform assays with arrays reconstituted with hyperacetylated or trypsinized histones and isolated histone (H3/H4)(2) tetramers. The results define three groups of the ATP-dependent family of remodeling enzymes. In addition we investigate the ability of an acidic activator to recruit remodeling complexes to nucleosomal arrays. We propose that ATP-dependent chromatin remodeling enzymes share a common reaction mechanism and that a key distinction between complexes is in their mode of regulation or recruitment.
Assuntos
Adenosina Trifosfatases/metabolismo , Trifosfato de Adenosina/metabolismo , Cromatina/metabolismo , Cromatina/química , Cinética , Conformação Proteica , Transativadores/metabolismoRESUMO
Hepatocarcinoma-intestine-pancreas/pancreatic associated protein (HIP/PAP) gene was identified because of its increased expression in 25% of human hepatocellular carcinoma. HIP/PAP protein, a C-type lectin, binds laminin, acts as an adhesion molecule for hepatocytes, and has also been described as an acute phase secretory protein during acute pancreatitis in humans and rats. We investigated HIP/PAP protein expression in patients with various liver diseases associated with ductular reaction. At the same time, we analyzed patients with hepatocellular carcinoma and cholangiocarcinoma, and tested HIP/PAP protein levels in sera to establish the pattern of secretion. Our data show that HIP/PAP expression was not restricted to hepatocellular carcinoma, but was also detected in cholangiocarcinoma cells as well as in reactive non-malignant bile ductules. In contrast, HIP/PAP protein expression was undetectable in normal mature hepatocytes, but some ductular cells localized at the interface of portal tracts with parenchyma were HIP/PAP immunoreactive in normal liver. Finally, we present evidence that HIP/PAP serum levels were increased in 21/28 (75%) patients with hepatocellular carcinoma, and in 25/51 (49%) patients with nonmalignant cirrhosis. Altogether, these results suggest that HIP/PAP protein may be implicated in hepatocytic and cholangiolar differentiation and proliferation.
Assuntos
Proteínas de Fase Aguda/biossíntese , Antígenos de Neoplasias , Neoplasias dos Ductos Biliares/metabolismo , Ductos Biliares Intra-Hepáticos/metabolismo , Biomarcadores Tumorais , Carcinoma Hepatocelular/metabolismo , Colangiocarcinoma/metabolismo , Lectinas Tipo C , Neoplasias Hepáticas/metabolismo , Adulto , Idoso , Animais , Neoplasias dos Ductos Biliares/patologia , Ductos Biliares Intra-Hepáticos/patologia , Carcinoma Hepatocelular/patologia , Colangiocarcinoma/patologia , Feminino , Humanos , Imuno-Histoquímica , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Proteínas Associadas a Pancreatite , RatosRESUMO
The proteins of the Polycomb group (PcG) are required for maintaining regulator genes, such as the homeotic selectors, stably and heritably repressed in appropriate developmental domains. It has been suggested that PcG proteins silence genes by creating higher-order chromatin structures at their chromosomal targets, thus preventing the interaction of components of the transcriptional machinery with their cis-regulatory elements. An unresolved issue is how higher order-structures are anchored at the chromatin base, the nucleosomal fiber. Here we show a direct biochemical interaction of a PcG protein-the Polycomb (PC) protein-with nucleosomal core particles in vitro. The main nucleosome-binding domain coincides with a region in the C-terminal part of PC previously identified as the repression domain. Our results suggest that PC, by binding to the core particle, recruits other PcG proteins to chromatin. This interaction could provide a key step in the establishment or regulation of higher-order chromatin structures.
Assuntos
Proteínas de Drosophila , Histonas/metabolismo , Proteínas de Insetos/metabolismo , Nucleossomos/metabolismo , Proteínas Repressoras/metabolismo , Animais , Sequência de Bases , Sítios de Ligação , DNA/metabolismo , Drosophila , Dados de Sequência Molecular , Complexo Repressor Polycomb 1 , Estrutura Terciária de Proteína , TripsinaRESUMO
We compared the efficacy of 4 methods for isolating circulating tumor cells: immunocapture with Ber-EP4-coated magnetic beads, density gradient separation, ammonium chloride, and distilled water-mediated erythrocyte lysis. Human blood from healthy volunteers was mixed with serial dilutions of prostate (LNCaP) and liver (HepG2) derived tumor cells. Isolation of circulating tumor cells was followed by reverse transcriptase-polymerase chain reaction with primers specific for prostate-specific antigen and alpha-fetoprotein. Ber-EP4 antigen expression was evaluated by immunohistochemistry in 27 hepatocellular carcinomas and 34 prostate adenocarcinomas. Peripheral blood samples from 12 patients with hepatocellular carcinoma and 10 with prostate adenocarcinoma also were tested. Density gradient separation and Ber-EP4 immunocapture were the most sensitive techniques for isolating circulating tumor cells in in vitro tests. Isolation by density gradient separation was significantly more sensitive than Ber-EP4 immunocapture when applied to peripheral blood samples of patients with cancer, a result consistent with the variable expression of Ber-EP4 antigen that we found by immunohistochemistry in prostate adenocarcinomas and hepatocellular carcinomas.
Assuntos
Antígenos de Superfície/imunologia , Biomarcadores Tumorais/imunologia , Separação Imunomagnética/métodos , Células Neoplásicas Circulantes , Adenocarcinoma/sangue , Cloreto de Amônio/farmacologia , Anticorpos Monoclonais , Carcinoma Hepatocelular/sangue , Centrifugação com Gradiente de Concentração/métodos , Primers do DNA/química , DNA de Neoplasias/análise , Células Epiteliais/imunologia , Células Epiteliais/patologia , Estudos de Avaliação como Assunto , Hemólise/efeitos dos fármacos , Humanos , Técnicas Imunoenzimáticas , Neoplasias Hepáticas/sangue , Masculino , Células Neoplásicas Circulantes/imunologia , Células Neoplásicas Circulantes/patologia , Antígeno Prostático Específico/genética , Neoplasias da Próstata/sangue , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Células Tumorais Cultivadas , alfa-Fetoproteínas/genéticaRESUMO
The chromatin accessibility complex (CHRAC) belongs to the class of nucleosome remodeling factors that increase the accessibility of nucleosomal DNA in an ATP-dependent manner. We found that CHRAC induces movements of intact histone octamers to neighboring DNA segments without facilitating their displacement to competing DNA or histone chaperones in trans. CHRAC-induced energy-dependent nucleosome sliding may, in principle, explain nucleosome remodeling, nucleosome positioning, and nucleosome spacing reactions known to be catalyzed by CHRAC. The catalytic core of CHRAC, the ATPase ISWI, also mobilized nucleosomes at the expense of energy. However, the directionality of the CHRAC- and ISWI-induced nucleosome movements differed drastically, indicating that the geometry of the native complex modulates the activity of its catalytic core.
Assuntos
Adenosina Trifosfatases/metabolismo , Cromatina/metabolismo , Histonas/metabolismo , Nucleossomos/metabolismo , Fatores de Transcrição/metabolismo , Animais , DNA/metabolismo , Drosophila , Ácido Poliglutâmico/metabolismoAssuntos
Cromatina/ultraestrutura , Histonas/metabolismo , Nucleossomos/ultraestrutura , Adenosina Trifosfatases/isolamento & purificação , Adenosina Trifosfatases/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Fracionamento Celular/métodos , Cromatografia em Gel , Diálise/métodos , Drosophila/embriologia , Embrião não Mamífero/ultraestrutura , Histonas/isolamento & purificação , Indicadores e Reagentes , Nucleossomos/metabolismo , Mapeamento por RestriçãoRESUMO
The ATPase ISWI is a subunit of several distinct nucleosome remodeling complexes that increase the accessibility of DNA in chromatin. We found that the isolated ISWI protein itself was able to carry out nucleosome remodeling, nucleosome rearrangement, and chromatin assembly reactions. The ATPase activity of ISWI was stimulated by nucleosomes but not by free DNA or free histones, indicating that ISWI recognizes a specific structural feature of nucleosomes. Nucleosome remodeling, therefore, does not require a functional interaction between ISWI and the other subunits of ISWI complexes. The role of proteins associated with ISWI may be to regulate the activity of the remodeling engine or to define the physiological context within which a nucleosome remodeling reaction occurs.
Assuntos
Adenosina Trifosfatases/fisiologia , Nucleossomos/ultraestrutura , Fatores de Transcrição/fisiologia , Adenosina Trifosfatases/genética , Animais , Sítios de Ligação , Cromatina/metabolismo , Cromatina/ultraestrutura , DNA/farmacologia , Drosophila melanogaster/genética , Escherichia coli , Regulação da Expressão Gênica , Substâncias Macromoleculares , Mutagênese Sítio-Dirigida , Nucleossomos/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcrição GênicaRESUMO
The Drosophila GAGA factor binds specifically to the sequence GAGAG, and synergises with nucleosome remodelling factor to remodel chromatin in vitro. It consists of an N-terminal domain (POZ/BTB) which mediates protein-protein interactions, a central region which contains the DNA-binding domain, and a C-terminal glutamine-rich region. It is shown that the glutamine-rich region is responsible for the formation of fibres in vitro which, on the basis of their tinctorial properties and CD spectra, may be classified as amyloid fibres. A large structural change, probably resulting in beta-sheet structure, is observed upon fibre formation. Mutants containing the central region, either alone or together with the glutamine-rich region, are largely lacking in secondary structure but they bind specifically to the cognate DNA and are able to remodel chromatin in vitro. Consequently, neither the N-terminal domain nor the C-terminal glutamine-rich regions of the GAGA factor are necessary for chromatin remodelling in vitro.
Assuntos
Amiloide/fisiologia , Cromatina/fisiologia , Proteínas de Ligação a DNA/fisiologia , Proteínas de Drosophila , Glutamina/fisiologia , Proteínas de Homeodomínio/fisiologia , Fatores de Transcrição/fisiologia , Amiloide/química , Animais , Benzotiazóis , Sítios de Ligação , Birrefringência , Vermelho Congo , Proteínas de Ligação a DNA/genética , Drosophila melanogaster , Corantes Fluorescentes , Glutamina/genética , Proteínas de Homeodomínio/genética , Mutagênese , Estrutura Secundária de Proteína , Proteínas Recombinantes de Fusão/genética , Relação Estrutura-Atividade , Tiazóis , Transativadores/química , Fatores de Transcrição/genéticaRESUMO
Duodeno-pancreatic biochemically polyfunctional endocrine tumour is a well known entity. Usually, only one hormone is responsible for the clinical features. We report a case of aggressive combined glucagonoma and gastrinoma tumour without metastases, causing respectively diabetic ketoacidosis and fulminant peptic ulcer, and death. Occasional patients can present with clinical features of both glucagonoma and gastrinoma. Diabetic patients exhibiting migratory skin lesions should be suspected of glucagonoma. In addition, a multidisciplinary approach to such patients including dermatologists, surgeons, radiologists and endoscopists is mandatory.
Assuntos
Gastrinoma/diagnóstico , Glucagonoma/diagnóstico , Neoplasias Primárias Múltiplas/diagnóstico , Neoplasias Pancreáticas/diagnóstico , Adulto , Cetoacidose Diabética/etiologia , Evolução Fatal , Feminino , Gastrinoma/complicações , Gastrinoma/metabolismo , Glucagonoma/complicações , Glucagonoma/metabolismo , Humanos , Neoplasias Primárias Múltiplas/metabolismo , Neoplasias Pancreáticas/metabolismo , Úlcera Péptica/etiologiaRESUMO
UNLABELLED: Models of liver regeneration are essential to understand mechanisms of hepatic carcinogenesis, correct genetic diseases by gene transfer or hepatocyte transplantation. The expression in the liver of transgenic mice of a gene coding for a urokinase-type plasminogen activator (uPA mouse) induces hepatotoxicity and prolonged post-native liver regeneration from cellular clones which have inactivated the transgene. This model may have major applications but it remains necessary to characterize the liver regeneration pattern. METHODS: Histological and immunohistochemical studies of the liver of uPA and non-transgenic mice, 3, 7, 14, 21, 28, 42 and 56 days-old. Markers of cellular proliferation: 5-bromo-2'deoxyuridine (BrdU) and proliferating cell nuclear antigen (PCNA). RESULTS: Regenerative nodules were seen from day 14. These nodules then grew, became confluent and by 8 weeks constituted the entire liver mass. A semi-quantitative study of BrdU and PCNA showed a maximal labeling at day 7 (300 to 350 labeled cells/10 microscopic fields, mag 400). When the nodules appeared, 60 to 80% of the cells were labeled. The proportion of labeled cells decreased but was still greater than that observed in non transgenic mice up to day 56 (92 to 106 labeled cells vs 10 to 28, on day 28). CONCLUSIONS: In uPA mouse liver regeneration is significantly expanded, as compared to the regeneration following partial hepatectom. This study therefore has allowed to determine the best conditions for using this model.
Assuntos
Regeneração Hepática/genética , Ativador de Plasminogênio Tipo Uroquinase/genética , Animais , Expressão Gênica/fisiologia , Fígado/patologia , Camundongos , Camundongos Transgênicos , Antígeno Nuclear de Célula em Proliferação/genéticaRESUMO
DNA replication is initiated by binding of initiation factors to the origin of replication. Nucleosomes are known to inhibit the access of the replication machinery to origin sequences. Recently, nucleosome remodelling factors have been identified that increase the accessibility of nucleosomal DNA to transcription regulators. To test whether the initiation of DNA replication from an origin covered by nucleosomes would also benefit from the action of nucleosome remodelling factors, we reconstituted SV40 DNA into chromatin in Drosophila embryo extracts. In the presence of T-antigen and ATP, a chromatin-associated cofactor allowed efficient replication from a nucleosomal origin in vitro. In search of the energy-dependent cofactor responsible we found that purified 'chromatin accessibility complex' (CHRAC) was able to alter the nucleosomal structure at the origin allowing the binding of T-antigen and efficient initiation of replication. These experiments provide evidence for the involvement of a nucleosome remodelling machine in structural changes at the SV40 origin of DNA replication in vitro.