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1.
J Eur Acad Dermatol Venereol ; 31(9): 1534-1540, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28485825

RESUMO

BACKGROUND: Human leishmaniasis is on increase in the Mediterranean Europe. However, the exact prevalence of cutaneous leishmaniasis (CL) is largely unknown as underdiagnosis and under reporting are common. OBJECTIVE: To evaluate epidemiological, clinicopathological and microbiological aspects of CL cases occurring in the Bologna Province, north-eastern Italy. METHODS: We performed a retrospective, observational study on CL cases diagnosed in the Bologna Province between January 2013 and December 2015. RESULTS: During 2013-2015, 30 cases of CL were identified in the Bologna Province with an average incidence of 1.00/100 000, with an increase of fourfold to 12-fold as compared to previous years. 16 of 30 (53%) CL cases presented as single, typical lesions. CL diagnosis was carried out by histological and molecular techniques, although in 7 of 29 (24%) PCR-positive cases, amastigotes were not visible on histology. CONCLUSIONS: We report new evidence of CL cases in a focal area of north-eastern Italy in 2013-2015. Our study highlights the importance of CL surveillance in the Mediterranean basin and emphasizes the need for the molecular laboratory surveillance of CL in endemic areas.


Assuntos
Leishmaniose Cutânea/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Itália/epidemiologia , Leishmaniose Cutânea/patologia , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Adulto Jovem
2.
Epidemiol Infect ; 144(9): 1912-6, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26751121

RESUMO

This report describes an increased number of cases of Chikungunya virus (CHIKV) infection imported in northern Italy (Emilia-Romagna region) during the period May-September 2014, indicating that the recent spread of CHIKV and its establishment in the Caribbean and in central America, resulted in a high number of imported cases in Europe, thus representing a threat to public health. From May to September 2014, 14 imported cases of CHIKV infection were diagnosed; the patients were returning to Italy from Dominican Republic (n = 6), Haiti (n = 3), Guadeloupe (n = 2), Martinique (n = 1), Puerto Rico (n = 1) and Venezuela (n = 1). Phylogenetic analysis performed on the envelope protein (E1) gene sequences, obtained from plasma samples from two patients, indicated that the virus strain belongs to the Caribbean clade of the Asian genotype currently circulating in the Caribbean and Americas. The rise in the number of imported cases of CHIKV infection should increase healthcare professionals' awareness of the epidemiological situation and clinical presentation of CHIKV infection in order to enhance surveillance and early diagnosis in the forthcoming season of vector activity in Europe and North America.


Assuntos
Febre de Chikungunya/epidemiologia , Vírus Chikungunya/isolamento & purificação , Viagem , Adulto , Idoso , Região do Caribe , América Central , Vírus Chikungunya/classificação , Vírus Chikungunya/genética , Criança , Feminino , Genótipo , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Filogenia , Análise de Sequência de DNA , Proteínas do Envelope Viral/genética , Adulto Jovem
3.
J Oral Rehabil ; 42(10): 759-64, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26059761

RESUMO

The aim of this study was to compare clinical sleep bruxism (SB) diagnosis with an instrumental diagnosis obtained with a device providing electromyography/electrocardiography (EMG/ECG) recordings. Forty-five (N = 45) subjects (19 males and 26 females, mean age 28 ± 11 years) were selected among patients referring to the Gnathology Unit of the Dental School of the University of Torino. An expert clinician assessed the presence of SB based on the presence of one or more signs/symptoms (i.e., transient jaw muscle pain in the morning, muscle fatigue at awakening, presence of tooth wear, masseter hypertrophy). Furthermore, all participants underwent an instrumental recording at home with a portable device (Bruxoff; OT Bioelettronica, Torino, Italy) allowing a simultaneous recording of EMG signals from both the masseter muscles as well as heart frequency. Statistical procedures were performed with the software Statistical Package for the Social Science v. 20.0 (SPSS 20.0; IBM, Milan, Italy). Based on the EMG/ECG analysis, 26 subjects (11 males, 15 females, mean age 28 ± 10 years) were diagnosed as sleep bruxers, whilst 19 subjects (7 males, 12 females, mean age 30 ± 10 years) were diagnosed as non-bruxers. The correlation between the clinical and EMG/ECG SB diagnoses was low (ϕ value = 0.250), with a 62.2% agreement (28/45 subjects) between the two approaches (kappa = 0.248). Assuming instrumental EMG/ECG diagnosis as the standard of reference for definite SB diagnosis in this investigation, the false-positive and false-negative rates were unacceptable for all clinical signs/symptoms. In conclusion, findings from clinical assessment are not related with SB diagnosis performed with a portable EMG/ECG recorder.


Assuntos
Eletrocardiografia/métodos , Eletromiografia/métodos , Monitorização Ambulatorial/instrumentação , Polissonografia/métodos , Bruxismo do Sono/diagnóstico , Adolescente , Adulto , Eletrocardiografia Ambulatorial/métodos , Feminino , Coração/fisiologia , Frequência Cardíaca/fisiologia , Humanos , Masculino , Músculo Masseter/fisiologia , Sensibilidade e Especificidade , Adulto Jovem
4.
Euro Surveill ; 19(44)2014 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-25394257

RESUMO

Predicting West Nile virus (WNV) circulation and the risk of WNV epidemics is difficult due to complex interactions of multiple factors involved. Surveillance systems that timely detect virus activity in targeted areas, and allow evidence-based risk assessments may therefore be necessary. Since 2009, a system integrating environmental (mosquitoes and birds) and human surveillance has been implemented and progressively improved in the Emilia-Romagna region, Italy. The objective is to increase knowledge of WNV circulation and to reduce the probability of virus transmission via blood, tissue and organ donation. As of 2013, the system has shown highly satisfactory results in terms of early detection capacity (the environmental surveillance component allowed detection of WNV circulation 3­4 weeks before human cases of West Nile neuroinvasive disease (WNND) occurred), sensitivity (capacity to detect virus circulation even at the enzootic level) and area specificity (capacity to indicate the spatial distribution of the risk for WNND). Strong correlations were observed between the vector index values and the number of human WNND cases registered at the province level. Taking into consideration two scenarios of surveillance, the first with environmental surveillance and the second without, the total costs for the period from 2009 to 2013 were reduced when environmental surveillance was considered (EUR 2.093 million for the first scenario vs EUR 2.560 million for the second). Environmental surveillance helped to reduce costs by enabling a more targeted blood unit testing strategy. The inclusion of environmental surveillance also increased the efficiency of detecting infected blood units and further allowed evidence-based adoption of preventative public health measures.


Assuntos
Aves/virologia , Culicidae/virologia , Vigilância da População/métodos , Febre do Nilo Ocidental/epidemiologia , Vírus do Nilo Ocidental/isolamento & purificação , Idoso , Animais , Feminino , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Medição de Risco , Febre do Nilo Ocidental/virologia
5.
Euro Surveill ; 19(48): 20978, 2014 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-25496572

RESUMO

Toscana virus (TOSV), transmitted by phlebotomine sandflies, is recognised as one of the most important causes of viral meningitis in summer in Mediterranean countries. A surveillance plan based on both human and entomological surveys was started in 2010 in the Emilia-Romagna region, Italy. Clinical samples from patients with neurological manifestations were collected during 2010 to 2012. The surveillance protocol was improved during these years, allowing the detection of 65 human infections. Most of these infections were recorded in hilly areas, where sandflies reach the highest density. Entomological sampling around the homes of the patients resulted in a low number of captured sandflies, while later sampling in a hilly area with high number of human cases (n=21) resulted in a larger number of captured sandflies. Using this approach, 25,653 sandflies were sampled, of which there were 21,157 females, which were sorted into 287 pools. TOSV RNA was detected by real-time PCR in 33 of the pools. The results highlighted the role of Phlebotomus perfiliewi as the main vector of TOSV and a potential link between vector density and virus circulation. This integrated system shows that an interdisciplinary approach improves the sensitiveness and effectiveness of health surveillance.


Assuntos
Vigilância da População , Psychodidae/virologia , RNA Viral/genética , Vírus da Febre do Flebótomo Napolitano/isolamento & purificação , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Animais , Feminino , Genótipo , Humanos , Imunoglobulina G , Imunoglobulina M , Insetos Vetores/virologia , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , RNA Viral/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Vírus da Febre do Flebótomo Napolitano/classificação , Vírus da Febre do Flebótomo Napolitano/genética , Análise de Sequência de DNA , Distribuição por Sexo , Adulto Jovem
6.
Biomech Model Mechanobiol ; 20(3): 1031-1046, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33792805

RESUMO

A Finite Element workflow for the multiscale analysis of the aortic valve biomechanics was developed and applied to three physiological anatomies with the aim of describing the aortic valve interstitial cells biomechanical milieu in physiological conditions, capturing the effect of subject-specific and leaflet-specific anatomical features from the organ down to the cell scale. A mixed approach was used to transfer organ-scale information down to the cell-scale. Displacement data from the organ model were used to impose kinematic boundary conditions to the tissue model, while stress data from the latter were used to impose loading boundary conditions to the cell level. Peak of radial leaflet strains was correlated with leaflet extent variability at the organ scale, while circumferential leaflet strains varied over a narrow range of values regardless of leaflet extent. The dependency of leaflet biomechanics on the leaflet-specific anatomy observed at the organ length-scale is reflected, and to some extent emphasized, into the results obtained at the lower length-scales. At the tissue length-scale, the peak diastolic circumferential and radial stresses computed in the fibrosa correlated with the leaflet surface area. At the cell length-scale, the difference between the strains in two main directions, and between the respective relationships with the specific leaflet anatomy, was even more evident; cell strains in the radial direction varied over a relatively wide range ([Formula: see text]) with a strong correlation with the organ length-scale radial strain ([Formula: see text]); conversely, circumferential cell strains spanned a very narrow range ([Formula: see text]) showing no correlation with the circumferential strain at the organ level ([Formula: see text]). Within the proposed simulation framework, being able to account for the actual anatomical features of the aortic valve leaflets allowed to gain insight into their effect on the structural mechanics of the leaflets at all length-scales, down to the cell scale.


Assuntos
Valva Aórtica/fisiologia , Modelos Cardiovasculares , Adulto , Valva Aórtica/diagnóstico por imagem , Diástole/fisiologia , Feminino , Humanos , Modelos Lineares , Imageamento por Ressonância Magnética , Masculino , Estresse Mecânico
8.
Science ; 286(5446): 1946-9, 1999 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-10583956

RESUMO

Osteoporosis and other diseases of bone loss are a major public health problem. Here it is shown that the statins, drugs widely used for lowering serum cholesterol, also enhance new bone formation in vitro and in rodents. This effect was associated with increased expression of the bone morphogenetic protein-2 (BMP-2) gene in bone cells. Lovastatin and simvastatin increased bone formation when injected subcutaneously over the calvaria of mice and increased cancellous bone volume when orally administered to rats. Thus, in appropriate doses, statins may have therapeutic applications for the treatment of osteoporosis.


Assuntos
Densidade Óssea/efeitos dos fármacos , Lovastatina/farmacologia , Osteoblastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Sinvastatina/farmacologia , Fator de Crescimento Transformador beta , Animais , Proteína Morfogenética Óssea 2 , Proteínas Morfogenéticas Ósseas/biossíntese , Proteínas Morfogenéticas Ósseas/genética , Proteínas Morfogenéticas Ósseas/farmacologia , Linhagem Celular , Feminino , Fator 1 de Crescimento de Fibroblastos , Fator 2 de Crescimento de Fibroblastos/farmacologia , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Técnicas de Cultura de Órgãos , Osteoblastos/metabolismo , Osteoclastos/efeitos dos fármacos , Osteoporose/tratamento farmacológico , Ovariectomia , Regiões Promotoras Genéticas/efeitos dos fármacos , Ratos , Proteínas Recombinantes/farmacologia , Crânio , Transfecção
9.
Phys Rev E Stat Nonlin Soft Matter Phys ; 79(6 Pt 1): 061126, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19658492

RESUMO

We investigate finite-size scaling aspects of disorder reaction-diffusion processes in one dimension utilizing both numerical and analytical approaches. The former averages the spectrum gap of the associated evolution operators by doubling their degrees of freedom, while the latter uses various techniques to map the equations of motion to a first-passage time process. Both approaches are consistent with nonuniversal dynamic exponents and with stretched exponential scaling forms for particular disorder realizations.

10.
Euro Surveill ; 14(50)2009 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-20070935

RESUMO

We report a case of Usutu virus (USUV)-related illness in a patient that underwent an orthotropic liver transplant (OLT). Post transplant, the patient developed clinical signs of a possible neuroinvasive disease with a significant loss of cerebral functions. USUV was isolated in Vero E6 cells from a plasma sample obtained immediately before the surgery, and USUV RNA was demonstrated by RT-PCR and sequencing. This report enlarges the panel of emerging mosquito-borne flavivirus-related disease in humans.


Assuntos
Infecções por Flavivirus/diagnóstico , Flavivirus/isolamento & purificação , Transplante de Fígado , Adulto , Feminino , Flavivirus/genética , Infecções por Flavivirus/etiologia , Humanos , Itália , Transplante de Fígado/efeitos adversos , Pessoa de Meia-Idade
11.
Euro Surveill ; 14(40)2009 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-19822123

RESUMO

In 2009, to date 16 human cases of West Nile neuroinvasive disease (WNND) have been reported in Italy, in three regions: Veneto, Emilia-Romagna and Lombardia. The number of cases is higher compared with last year when nine cases were identified (eight cases of WNND and one case of West Nile fever) and the geographical distribution indicates spread from east to west.


Assuntos
Surtos de Doenças/estatística & dados numéricos , Febre do Nilo Ocidental/epidemiologia , Febre do Nilo Ocidental/transmissão , Feminino , Humanos , Incidência , Itália/epidemiologia , Masculino , Vigilância da População , Medição de Risco/métodos , Fatores de Risco
12.
J Clin Invest ; 111(11): 1771-82, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12782679

RESUMO

We have found that the ubiquitin-proteasome pathway exerts exquisite control of osteoblast differentiation and bone formation in vitro and in vivo in rodents. Structurally different inhibitors that bind to specific catalytic beta subunits of the 20S proteasome stimulated bone formation in bone organ cultures in concentrations as low as 10 nM. When administered systemically to mice, the proteasome inhibitors epoxomicin and proteasome inhibitor-1 increased bone volume and bone formation rates over 70% after only 5 days of treatment. Since the ubiquitin-proteasome pathway has been shown to modulate expression of the Drosophila homologue of the bone morphogenetic protein-2 and -4 (BMP-2 and BMP-4) genes, we examined the effects of noggin, an endogenous inhibitor of BMP-2 and BMP-4 on bone formation stimulated by these compounds and found that it was abrogated. These compounds increased BMP-2 but not BMP-4 or BMP-6 mRNA expression in osteoblastic cells, suggesting that BMP-2 was responsible for the observed bone formation that was inhibited by noggin. We show proteasome inhibitors regulate BMP-2 gene expression at least in part through inhibiting the proteolytic processing of Gli3 protein. Our results suggest that the ubiquitin-proteasome machinery regulates osteoblast differentiation and bone formation and that inhibition of specific components of this system may be useful therapeutically in common diseases of bone loss.


Assuntos
Desenvolvimento Ósseo , Osso e Ossos/metabolismo , Complexos Multienzimáticos/antagonistas & inibidores , Osteoblastos/metabolismo , Fator de Crescimento Transformador beta , Animais , Northern Blotting , Western Blotting , Proteína Morfogenética Óssea 2 , Proteína Morfogenética Óssea 4 , Proteínas Morfogenéticas Ósseas/metabolismo , Proteínas de Transporte , Divisão Celular , Linhagem Celular , Cisteína Endopeptidases/metabolismo , DNA/metabolismo , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Vetores Genéticos , Humanos , Luciferases/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Complexos Multienzimáticos/metabolismo , Técnicas de Cultura de Órgãos , Regiões Promotoras Genéticas , Complexo de Endopeptidases do Proteassoma , Proteínas/metabolismo , RNA Mensageiro/metabolismo , Crânio/metabolismo , Transcrição Gênica , Transfecção
13.
J Orthop Res ; 25(10): 1351-7, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17506505

RESUMO

Statins stimulate bone formation in vitro and in vivo and, when given in large doses or by prolonged infusions, stimulate biomechanical strength of murine long bones with healing fractures. However, administration of statins by large oral doses or prolonged infusions to a fracture site is not a feasible therapeutic approach to hasten healing of human fractures. We administered lovastatin in biodegradable polymer nanobeads of poly(lactic-co-glycolide acid) to determine if lovastatin delivered in low doses in nanoparticles of a therapeutically acceptable scaffold could increase rates of healing in a standard preclinical model of femoral fracture. We found that these nanobeads: (1) stimulated bone formation in vitro at 5 ng/mL, (2) increased rates of healing in femoral fractures when administered as a single injection into the fracture site, and (3) decreased cortical fracture gap at 4 weeks as assessed by microcomputed tomography. These preclinical results suggest that lovastatin administered in a nanobead preparation may be therapeutically useful in hastening repair of human fractures.


Assuntos
Anticolesterolemiantes/administração & dosagem , Sistemas de Liberação de Medicamentos , Fraturas do Fêmur/tratamento farmacológico , Consolidação da Fratura/efeitos dos fármacos , Lovastatina/administração & dosagem , Nanopartículas/administração & dosagem , Osteogênese/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Fraturas do Fêmur/diagnóstico por imagem , Fraturas do Fêmur/patologia , Camundongos , Camundongos Endogâmicos ICR , Nanopartículas/ultraestrutura , Técnicas de Cultura de Órgãos , Osteogênese/fisiologia , Radiografia , Ratos , Ratos Sprague-Dawley , Crânio/efeitos dos fármacos , Crânio/patologia
15.
Clin Microbiol Infect ; 23(11): 868-873, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28344163

RESUMO

OBJECTIVES: Among sandfly-borne pathogens, Toscana virus (TOSV) is a prominent cause of summer meningitis in Mediterranean Europe. Here, we assessed the kinetics of anti-TOSV antibodies over time in 41 patients diagnosed with TOSV meningitis or meningoencephalitis in northeastern Italy. METHODS: Acute and follow-up serum samples were collected up to 20 months after diagnosis of TOSV infection and tested for the presence of specific antibody using immunoenzymatic and indirect immunofluorescence assays. In addition, maturation of anti-TOSV IgG over time was evaluated as well as production of neutralizing antibodies. RESULTS: Specific IgM and IgG response was present at diagnosis in 100% of patients; TOSV-specific IgM and IgG were detected in patients' sera up to 6 and 20 months after diagnosis, respectively. The avidity index (AI) increased over the first month after infection in 100% of patients and most cases exceeded 60% by Day 30 post infection. The AI subsequently plateaued then declined at 20 months after diagnosis. Finally, neutralization assay to TOSV was performed in 217 sera collected from 41 patients; 69.6% of tested samples resulted in reactive and moderate levels of neutralizing antibodies observed during all phases of infection despite high titres of total anti-TOSV IgG. CONCLUSIONS: Specific antibody response develops rapidly and is long-lasting for neuroinvasive TOSV infection. Serodiagnosis of neuroinvasive TOSV requires simultaneous detection of specific IgM and IgG. Moderate levels of neutralizing antibodies were maintained over the study period, while the protective role of antibodies lacking neutralizing activity is unclear and requires further evaluation.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Bunyaviridae/imunologia , Meningite Viral/imunologia , Vírus da Febre do Flebótomo Napolitano/imunologia , Adulto , Anticorpos Neutralizantes/sangue , Estudos de Coortes , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Masculino , Pessoa de Meia-Idade
16.
Int J Oral Maxillofac Surg ; 45(11): 1438-1444, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27609710

RESUMO

Mandibular distraction osteogenesis (MDO) has been widely adopted in modern maxillofacial surgery due to its less invasive approach and the consistent aesthetic and functional improvements obtained. The aim of the present systematic review was to analyze the available evidence on the skeletal and soft tissue effects of MDO. The medical literature was searched to identify all peer-reviewed papers meeting the selection criteria for the final review process. A three-point grading system was used to rate the methodological quality of the selected papers. The PICO approach was used to extract data from the selected papers. The search strategy yielded eight relevant publications. The quality of the collected evidence was low to moderate. Vertical and sagittal skeletal dimensions increased significantly, by a mean of 5-10mm (P<0.05). Regarding the sagittal positioning of the lips and surrounding structures, a 90% correspondence between skeletal and soft tissue cephalometric points was observed. Significant skeletal relapse was reported, however it did not worsen the results of treatment significantly.


Assuntos
Mandíbula/cirurgia , Osteogênese por Distração/métodos , Cefalometria , Tecido Conjuntivo/anatomia & histologia , Estética Dentária , Humanos , Mandíbula/anatomia & histologia , Complicações Pós-Operatórias , Crânio/anatomia & histologia
17.
Nat Commun ; 7: 12592, 2016 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-27558021

RESUMO

Among the frustrated magnetic materials, spin-ice stands out as a particularly interesting system. Residual entropy, freezing and glassiness, Kasteleyn transitions and fractionalization of excitations in three dimensions all stem from a simple classical Hamiltonian. But is the usual spin-ice Hamiltonian a correct description of the experimental systems? Here we address this issue by measuring magnetic susceptibility in the two most studied spin-ice compounds, Dy2Ti2O7 and Ho2Ti2O7, using a vector magnet. Using these results, and guided by a theoretical analysis of possible distortions to the pyrochlore lattice, we construct an effective Hamiltonian and explore it using Monte Carlo simulations. We show how this Hamiltonian reproduces the experimental results, including the formation of a phase of intermediate polarization, and gives important information about the possible ground state of real spin-ice systems. Our work suggests an unusual situation in which distortions might contribute to the preservation rather than relief of the effects of frustration.

18.
Biochim Biophys Acta ; 924(1): 119-26, 1987 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-3828391

RESUMO

The contention that transformation of steroid-receptor complexes is represented by dissociation of receptor oligomers was tested by comparing sedimentation and DNA binding properties of glucocorticoid-receptor complexes from HeLa cell cytosol under several conditions. Transformation of glucocorticoid-receptor complexes could be induced by heat, and/or salt treatment of cytosolic extracts, but not by dilution. Heat-induced transformation of receptor complexes was also confirmed by DEAE-cellulose chromatography. Analysis of cytosolic extracts showed that sedimentation and DNA binding properties of glucocorticoid-receptor complexes did not correlate. Both oligomeric and monomeric receptor complexes, in fact, were found to be either transformed, or untransformed, depending on the treatments cytosolic extracts underwent, before being subjected to analysis. We then concluded that release of glucocorticoid receptor monomers cannot account for their transformation to a DNA-binding form in vitro, and suggested that exposure of positive charges on the surface of receptors in the course of transformation occurs in some region of the glucocorticoid receptor which is not involved in interactions between the proteinaceous components of oligomers.


Assuntos
DNA/metabolismo , Receptores de Glucocorticoides/metabolismo , Celulose/análogos & derivados , Celulose/metabolismo , DNA/análogos & derivados , Dexametasona/metabolismo , Células HeLa/metabolismo , Humanos , Substâncias Macromoleculares , Ligação Proteica , Receptores de Glucocorticoides/isolamento & purificação
19.
Biochim Biophys Acta ; 1011(2-3): 183-91, 1989 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-2713403

RESUMO

When control HeLa cells were incubated at 2 degrees C in the presence of tritiated dexamethasone, most glucocorticoid-receptor complexes were found in cytosolic extracts as untransformed forms. Chemical crosslinking of intact HeLa cells resulted in the immobilization of 50% of the total cellular glucocorticoid-receptor complexes in the nuclear fraction. Under these conditions the redistribution of total protein, RNA and lactate dehydrogenase activity between cytosol and nuclei was negligible, indicating that glucocorticoid binding in the nuclear fraction was not due to a methodological artifact. High levels of glucocorticoid receptor were also found in the nuclear fraction of crosslinked cells which were not exposed to glucocorticoids. Nuclear receptor complexes could be released in soluble forms by DNase I and sonication. Evaluations of DNA binding and ionic properties of glucocorticoid receptors prepared from control and crosslinked cells maintained at 2 degrees C revealed that most of the hormone-receptor complex in cytosols and nuclear extracts behaved as untransformed forms. As opposed to glucocorticoid receptors prepared from control cells, heat treatment of extracts obtained from crosslinked cells did not result in increased DNA binding and changes in ionic properties of receptor complexes. I conclude that untransformed glucocorticoid receptors are present in both cytosol and nuclei of intact cells.


Assuntos
Núcleo Celular/análise , Citosol/análise , Receptores de Glucocorticoides/metabolismo , Cromatografia DEAE-Celulose , Reagentes de Ligações Cruzadas/farmacologia , DNA/metabolismo , Formaldeído/farmacologia , Células HeLa/efeitos dos fármacos , Células HeLa/metabolismo , Humanos , Íons , Receptores de Glucocorticoides/efeitos dos fármacos , Frações Subcelulares/análise
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