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1.
Eur J Surg Oncol ; 43(8): 1393-1401, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28596034

RESUMO

BACKGROUND: Breast implant-associated anaplastic large-cell lymphoma (BIA-ALCL) is a rare, Non-Hodgkin lymphoma arising in the capsule of breast implants. BIA-ALCL presents as a recurrent effusion and/or mass. Tumours exhibit CD30 expression and are negative for Anaplastic Lymphoma Kinase (ALK). We report the multi-disciplinary management of the UK series and how the stage of disease may be used to stratify treatment. METHODS: Between 2012 and 2016, 23 cases of BIA-ALCL were diagnosed in 15 regional centres throughout the UK. Data on breast implant surgeries, clinical features, treatment and follow-up were available for 18 patients. RESULTS: The mean lead-time from initial implant insertion to diagnosis was 10 years (range: 3-16). All cases were observed in patients with textured breast implants or expanders. Fifteen patients with breast implants presented with stage I disease (capsule confined), and were treated with implant removal and capsulectomy. One patient received adjuvant chest-wall radiotherapy. Three patients presented with extra-capsular masses (stage IIA). In addition to explantation, capsulectomy and excision of the mass, all patients received neo-/adjuvant chemotherapy with CHOP as first line. One patient progressed on CHOP but achieved pathological complete response (pCR) with Brentuximab Vedotin. After a mean follow-up of 23 months (range: 1-56) all patients reported here remain disease-free. DISCUSSION: BIA-ALCL is a rare neoplasm with a good prognosis. Our data support the recommendation that stage I disease be managed with surgery alone. Adjuvant chemotherapy may be required for more invasive disease and our experience has shown the efficacy of Brentuximab as a second line treatment.


Assuntos
Implantes de Mama/efeitos adversos , Neoplasias da Mama/etiologia , Neoplasias da Mama/terapia , Consentimento Livre e Esclarecido , Linfoma Anaplásico de Células Grandes/etiologia , Linfoma Anaplásico de Células Grandes/terapia , Adulto , Idoso , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/patologia , Terapia Combinada , Remoção de Dispositivo , Feminino , Humanos , Linfoma Anaplásico de Células Grandes/epidemiologia , Linfoma Anaplásico de Células Grandes/patologia , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Resultado do Tratamento , Reino Unido/epidemiologia
2.
Leukemia ; 30(6): 1273-81, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26987906

RESUMO

Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a predictive biomarker of disease progression in many malignancies, including imatinib-treated chronic myeloid leukemia (CML). Although high CIP2A levels correlate with disease progression in CML, the underlying molecular mechanisms remain elusive. In a screen of diagnostic chronic phase samples from patients with high and low CIP2A protein levels, high CIP2A levels correlate with an antiapoptotic phenotype, characterized by downregulation of proapoptotic BCL-2 family members, including BIM, PUMA and HRK, and upregulation of the antiapoptotic protein BCL-XL. These results suggest that the poor prognosis of patients with high CIP2A levels is due to an antiapoptotic phenotype. Disrupting this antiapoptotic phenotype by inhibition of BCL-XL via RNA interference or A-1331852, a novel, potent and BCL-XL-selective inhibitor, resulted in extensive apoptosis either alone or in combination with imatinib, dasatinib or nilotinib, both in cell lines and in primary CD34(+) cells from patients with high levels of CIP2A. These results demonstrate that BCL-XL is the major antiapoptotic survival protein and may be a novel therapeutic target in CML.


Assuntos
Apoptose/efeitos dos fármacos , Autoantígenos/sangue , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Proteínas de Membrana/sangue , Proteína bcl-X/antagonistas & inibidores , Adolescente , Adulto , Idoso , Benzotiazóis/farmacologia , Benzotiazóis/uso terapêutico , Biomarcadores Tumorais/sangue , Linhagem Celular Tumoral , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Isoquinolinas/farmacologia , Isoquinolinas/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Proteínas Proto-Oncogênicas c-bcl-2 , Células Tumorais Cultivadas , Adulto Jovem
3.
Cell Death Differ ; 22(8): 1388-96, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25656655

RESUMO

The unfolded protein response (UPR) occurs following the accumulation of unfolded proteins in the endoplasmic reticulum (ER) and orchestrates an intricate balance between its prosurvival and apoptotic arms to restore cellular homeostasis and integrity. However, in certain neurodegenerative diseases, the apoptotic arm of the UPR is enhanced, resulting in excessive neuronal cell death and disease progression, both of which can be overcome by modulating the UPR. Here, we describe a novel crosstalk between glucocorticoid receptor signaling and the apoptotic arm of the UPR, thus highlighting the potential of glucocorticoid therapy in treating neurodegenerative diseases. Several glucocorticoids, but not mineralocorticoids, selectively antagonize ER stress-induced apoptosis in a manner that is downstream of and/or independent of the conventional UPR pathways. Using GRT10, a novel selective pharmacological modulator of glucocorticoid signaling, we describe the importance of the transrepression arm of the glucocorticoid signaling pathway in protection against ER stress-induced apoptosis. Furthermore, we also observe the protective effects of glucocorticoids in vivo in a Drosophila model of Huntington's disease (HD), wherein treatment with different glucocorticoids diminished rhabdomere loss and conferred neuroprotection. Finally, we find that growth differentiation factor 15 has an important role downstream of glucocorticoid signaling in antagonizing ER stress-induced apoptosis in cells, as well as in preventing HD-mediated neurodegeneration in flies. Thus, our studies demonstrate that this novel crosstalk has the potential to be effectively exploited in alleviating several neurodegenerative disorders.


Assuntos
Proteínas do Tecido Nervoso/metabolismo , Doenças Neurodegenerativas/metabolismo , Receptores de Glucocorticoides/metabolismo , Animais , Apoptose/genética , Apoptose/fisiologia , Drosophila , Estresse do Retículo Endoplasmático/genética , Estresse do Retículo Endoplasmático/fisiologia , Células HeLa , Humanos , Proteínas do Tecido Nervoso/genética , Doenças Neurodegenerativas/genética , Receptores de Glucocorticoides/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Resposta a Proteínas não Dobradas/genética , Resposta a Proteínas não Dobradas/fisiologia
5.
Occup Med (Lond) ; 63(7): 507-9, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23990507

RESUMO

BACKGROUND: Common mental disorders are the leading cause of sickness absence but are frequently misdiagnosed and undertreated. It is against this background that a specialist occupational psychiatry clinic was established at a London teaching hospital. AIMS: To explore the nature of patients and complaints seen in the clinic and investigate whether this form of service provision reached patients who may have otherwise been missed in the gap between primary and secondary care. METHODS: We reviewed the case notes of 51 consecutive new clinic assessments using a data extraction form, gathering information on socio-demographic and occupational details; the nature, duration and severity of symptoms [as assessed by Health of the Nation Outcome Scale (HoNOS)]; diagnosis; prior treatment and the outcome of the clinic appointment. RESULTS: Only half of those seen in the new clinic were currently on sick leave. The most common diagnosis was depression with most having symptoms lasting longer than 9 months. Sixty-five per cent had a medium or high HoNOS rating. Although 75% had received treatment from their general practitioner, the majority remained functionally impaired, and only 31% had been seen in secondary care. CONCLUSIONS: Specialist occupational psychiatry clinics do not replicate the work already being done by standard mental health services. Patients referred to a new specialist clinic within an occupational health department had chronic, debilitating psychiatric illnesses, which in many cases had failed to respond adequately to primary care treatment and were at risk of falling into the gap between primary and secondary services.


Assuntos
Atenção à Saúde , Depressão/epidemiologia , Transtorno Depressivo/epidemiologia , Transtornos Mentais , Serviços de Saúde do Trabalhador , Psiquiatria , Licença Médica , Adolescente , Adulto , Instituições de Assistência Ambulatorial , Depressão/terapia , Transtorno Depressivo/terapia , Feminino , Humanos , Londres/epidemiologia , Masculino , Transtornos Mentais/terapia , Pessoa de Meia-Idade , Atenção Primária à Saúde , Estudos Retrospectivos , Atenção Secundária à Saúde , Adulto Jovem
6.
Cell Death Differ ; 20(11): 1475-84, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23832116

RESUMO

High levels of BCL-2 family proteins are implicated in a failed/ineffective apoptotic programme, often resulting in diseases, including cancer. Owing to their potential as drug targets in cancer therapy, several inhibitors of BCL-2 family proteins have been developed. These primarily target specific members of the BCL-2 family, particularly BCL-2 and BCL-XL but are ineffective against MCL-1. Major efforts have been invested in developing inhibitors of MCL-1, which is commonly amplified in human tumours and associated with tumour relapse and chemoresistance. In this report, the specificity of several BCL-2 family inhibitors (ABT-263, UCB-1350883, apogossypol and BH3I-1) was investigated and compared with putative MCL-1 inhibitors designed to exhibit improved or selective binding affinities for MCL-1 (TW-37, BI97C1, BI97C10, BI112D1, compounds 6 and 7, and MCL-1 inhibitor molecule (MIM-1)). ABT-263, BI97C1, BI112D1, MIM-1 and TW-37 exhibited specificity in inducing apoptosis in a Bax/Bak- and caspase-9-dependent manner, whereas the other agents showed no killing activity, or little or no specificity. Of these inhibitors, only ABT-263 and UCB-1350883 induced apoptosis in a BCL-2- or BCL-XL-dependent system. In cells that depend on MCL-1 for survival, ABT-263 and TW-37 induced extensive apoptosis, suggesting that at high concentrations these inhibitors have the propensity to inhibit MCL-1 in a cellular context. TW-37 induced apoptosis, assessed by chromatin condensation, caspase processing and phosphatidylserine externalisation, in a BAK-dependent manner and in cells that require MCL-1 for survival. TW-37-mediated apoptosis was also partly dependent on NOXA, suggesting that derivatives of TW-37, if engineered to exhibit better selectivity and efficacy at low nanomolar concentrations, may provide useful lead compounds for further synthetic programmes. Expanded medicinal chemistry iteration, as performed for the ABT series, may likewise improve the potency and specificity of the evaluated MCL-1 inhibitors.


Assuntos
Compostos de Anilina/farmacologia , Benzamidas/farmacologia , Proteína de Sequência 1 de Leucemia de Células Mieloides/antagonistas & inibidores , Sulfonamidas/farmacologia , Sulfonas/farmacologia , Apoptose/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Humanos , Células Jurkat , Proteína de Sequência 1 de Leucemia de Células Mieloides/genética , Proteína de Sequência 1 de Leucemia de Células Mieloides/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteína X Associada a bcl-2/metabolismo
7.
Cell Tissue Res ; 351(2): 309-23, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22729487

RESUMO

Proteases perform a diverse array of biological functions. From simple peptide digestion for nutrient absorption to complex signaling cascades, proteases are found in organisms from prokaryotes to humans. In the human airway, proteases are associated with the regulation of the airway surface liquid layer, tissue remodeling, host defense and pathogenic infection and inflammation. A number of proteases are released in the airways under both physiological and pathophysiological states by both the host and invading pathogens. In airway diseases such as cystic fibrosis, proteases have been shown to be associated with increased morbidity and airway disease progression. In this review, we focus on the regulation of proteases and discuss specifically those proteases found in human airways. Attention then shifts to the epithelial sodium channel (ENaC), which is regulated by proteolytic cleavage and that is considered to be an important component of cystic fibrosis disease. Finally, we discuss bacterial proteases, in particular, those of the most prevalent bacterial pathogen found in cystic fibrosis, Pseudomonas aeruginosa.


Assuntos
Fibrose Cística/metabolismo , Canais Epiteliais de Sódio/metabolismo , Peptídeo Hidrolases/metabolismo , Animais , Fibrose Cística/enzimologia , Fibrose Cística/microbiologia , Humanos , Pseudomonas aeruginosa/fisiologia
8.
Cell Death Differ ; 19(12): 1896-907, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22955944

RESUMO

Canonical endoplasmic reticulum (ER) stress, which occurs in many physiological and disease processes, results in activation of the unfolded protein response (UPR). We now describe a new, evolutionarily conserved cellular stress response characterised by a striking, but reversible, reorganisation of ER membranes that occurs independently of the UPR, resulting in impaired ER transport and function. This reorganisation is characterised by a dramatic redistribution and clustering of ER membrane proteins. ER membrane aggregation is regulated, in part, by anti-apoptotic BCL-2 family members, particularly MCL-1. Using connectivity mapping, we report the widespread occurrence of this stress response by identifying several structurally diverse chemicals from different pharmacological classes, including antihistamines, antimalarials and antipsychotics, which induce ER membrane reorganisation. Furthermore, we demonstrate the potential of ER membrane aggregation to result in pathological consequences, such as the long-QT syndrome, a cardiac arrhythmic abnormality, arising because of a novel trafficking defect of the human ether-a-go-go-related channel protein from the ER to the plasma membrane. Thus, ER membrane reorganisation is a feature of a new cellular stress pathway, clearly distinct from the UPR, with important consequences affecting the normal functioning of the ER.


Assuntos
Retículo Endoplasmático/metabolismo , Animais , Linhagem Celular , Estresse do Retículo Endoplasmático , Canais de Potássio Éter-A-Go-Go/metabolismo , Gossipol/análogos & derivados , Gossipol/farmacologia , Células HeLa , Humanos , Células MCF-7 , Camundongos , Proteína de Sequência 1 de Leucemia de Células Mieloides , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Resposta a Proteínas não Dobradas/efeitos dos fármacos
9.
Cell Death Differ ; 19(9): 1424-34, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22361683

RESUMO

Ubiquitin (Ub)-mediated proteasome-dependent proteolysis is critical in regulating multiple biological processes including apoptosis. We show that the unstructured BH3-only protein, NOXA, is degraded by an Ub-independent mechanism requiring 19S regulatory particle (RP) subunits of the 26S proteasome, highlighting the possibility that other unstructured proteins reported to be degraded by 20S proteasomes in vitro may be bona fide 26S proteasome substrates in vivo. A lysine-less NOXA (NOXA-LL) mutant, which is not ubiquitinated, is degraded at a similar rate to wild-type NOXA. Myeloid cell leukemia 1, but not other anti-apoptotic BCL-2 family proteins, stabilizes NOXA by interaction with the NOXA BH3 domain. Depletion of 19S RP subunits, but not alternate proteasome activator REG subunits, increases NOXA half-life in vivo. A NOXA-LL mutant, which is not ubiquitinated, also requires an intact 26S proteasome for degradation. Depletion of the 19S non-ATPase subunit, PSMD1 induces NOXA-dependent apoptosis. Thus, disruption of 26S proteasome function by various mechanisms triggers the rapid accumulation of NOXA and subsequent cell death strongly implicating NOXA as a sensor of 26S proteasome integrity.


Assuntos
Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Ubiquitina/metabolismo , Apoptose/fisiologia , Células HeLa , Humanos , Mutação de Sentido Incorreto , Proteína de Sequência 1 de Leucemia de Células Mieloides , Complexo de Endopeptidases do Proteassoma/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Ubiquitina/genética , Ubiquitinação/fisiologia
10.
Cell Death Differ ; 15(5): 820-30, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18309326

RESUMO

Primary chronic lymphocytic leukemia (CLL) cells are exquisitely sensitive to ABT-737, a small molecule BCL2-antagonist, which induces many of the classical biochemical and ultrastructural features of apoptosis, including BAX/BAK oligomerization, cytochrome c release, caspase activation and chromatin condensation. Surprisingly, ABT-737 also induces mitochondrial inner membrane permeabilization (MIMP) resulting in mitochondrial matrix swelling and rupture of the outer mitochondrial membrane (OMM), so permitting the rapid efflux of cytochrome c from mitochondrial cristae and facilitating rapid caspase activation and apoptosis. BAX and BAK appear to be involved in the OMM discontinuities as they localize to the OMM break points. Notably, ABT-737 induced mitochondrial matrix swelling and OMM discontinuities in other primary B-cell malignancies, including mantle cell, follicular and marginal zone lymphoma cells but not in several cell lines studied. Thus, we describe a new paradigm of apoptosis in primary B-cell malignancies, whereby targeting of BCL2 results in all the classical features of apoptosis together with OMM rupture independent of caspase activation. This mechanism may be far more prevalent than hitherto recognized due to the failure of most methods, used to measure apoptosis, to recognize such a mechanism.


Assuntos
Apoptose/efeitos dos fármacos , Compostos de Bifenilo/farmacologia , Leucemia Linfocítica Crônica de Células B/metabolismo , Membranas Mitocondriais/efeitos dos fármacos , Nitrofenóis/farmacologia , Sulfonamidas/farmacologia , Adulto , Clorometilcetonas de Aminoácidos/metabolismo , Linfócitos B/efeitos dos fármacos , Linfócitos B/metabolismo , Linfócitos B/patologia , Linhagem Celular Tumoral , Inibidores de Cisteína Proteinase/metabolismo , Relação Dose-Resposta a Droga , Humanos , Leucemia Linfocítica Crônica de Células B/patologia , Membranas Mitocondriais/ultraestrutura , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Proteína X Associada a bcl-2/metabolismo
11.
Br Dent J ; 203(1): E1; discussion 38-9, 2007 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-17273180

RESUMO

OBJECTIVES: The objectives of this study were to determine on what evidence infective endocarditis (IE) could be legally linked to dental treatment. METHOD: The records of 319 legal cases involving dental treatment as the probable cause of IE were analysed. The medical history, type of dental operation, and whether antibiotic prophylaxis was provided were noted. The time taken for the onset of symptoms (incubation period) and hospitalisation was calculated. The identity of the infecting micro-organism was investigated and it was also noted whether litigation was successful for the patient. RESULTS: A total of 83 patients were successful in legally linking dental treatment to the onset of infective endocarditis. In all successful cases there was a short incubation period (circa nine days) and in 80 of the patients an oral Streptococcus was isolated. The dental operations included exodontia (28), scaling (29), endodontics (12) and minor oral surgery (11). CONCLUSIONS: Dental treatment was deemed to be the probable cause of IE in 26% of patients who sought litigation. In the majority of legal cases clinicians did not follow recognised guidelines or keep adequate clinical notes. The three main factors which link dental procedures legally were the dental operation, the isolation from the blood of an oral micro-organism and a short incubation period.


Assuntos
Assistência Odontológica para Doentes Crônicos/legislação & jurisprudência , Assistência Odontológica para Doentes Crônicos/normas , Assistência Odontológica/efeitos adversos , Endocardite Bacteriana/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibioticoprofilaxia/estatística & dados numéricos , Registros Odontológicos/legislação & jurisprudência , Feminino , Fidelidade a Diretrizes , Humanos , Jurisprudência , Masculino , Anamnese , Pessoa de Meia-Idade , Estudos Retrospectivos , Streptococcus sanguis/isolamento & purificação
12.
Am J Physiol Renal Physiol ; 289(5): F969-77, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15972388

RESUMO

Acute regulation of epithelial sodium channel (ENaC) function at the apical surface of polarized kidney cortical collecting duct (CCD) epithelial cells occurs in large part by changes in channel number, mediated by membrane vesicle trafficking. Several soluble N-ethyl-maleimide-sensitive factor attachment protein receptors (SNARE) have been implicated in this process. A novel SNARE-binding protein, complexin, has been identified in nervous tissue which specifically binds to and stabilizes SNARE complexes at synaptic membranes to promote vesicle fusion. To test whether this protein is present in mouse CCD (mCCD) cells and its possible involvement in acute ENaC regulation, we cloned complexin (isoform II) from a mouse kidney cDNA library. Complexin II mRNA coexpressed with alpha-, beta-, and gamma-ENaC subunits in Xenopus laevis oocytes reduced sodium currents to 16 +/- 3% (n = 19) of control values. Short-circuit current (I(sc)) measurements on mCCD cell lines stably over- or underexpressing complexin produced similar results. Basal I(sc) was reduced from 12.0 +/- 1.0 (n = 15) to 2.0 +/- 0.4 (n = 15) and 1.8 +/- 0.3 (n = 17) microA/cm(2), respectively. Similarly forskolin-stimulated I(sc) was reduced from control values of 20.0 +/- 2 to 2.7 +/- 0.5 and 2.3 +/- 0.4 microA/cm(2) by either increasing or decreasing complexin expression. Surface biotinylation demonstrated that the complexin-induced reduction in basal I(sc)was due to a reduction in apical membrane-resident ENaC and the inhibition in forskolin stimulation was due to the lack of ENaC insertion into the apical membrane to increase surface channel number. Immunofluorescent localization of SNARE proteins in polarized mCCD epithelia detected the presence of syntaxins 1 and 3 and synaptosomal-associated protein of 23 kDa (SNAP-23) at the apical membrane, and vesicle-associated membrane protein (VAMP2) was localized to intracellular compartments. These findings identify SNAREs that may mediate ENaC-containing vesicle insertion in mCCD epithelia and suggest that stabilization of SNARE interactions by complexin is an essential aspect of the regulated trafficking events that increase apical membrane ENaC density either by constitutive or regulated trafficking pathways.


Assuntos
Túbulos Renais Coletores/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Canais de Sódio/fisiologia , Proteínas Adaptadoras de Transporte Vesicular , Animais , Clonagem Molecular , Canais Epiteliais de Sódio , Biblioteca Gênica , Camundongos , Proteínas do Tecido Nervoso/genética , Oócitos , Sódio/farmacocinética , Vesículas Sinápticas/fisiologia , Xenopus laevis
13.
Br J Cancer ; 91(6): 1213-9, 2004 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-15292928

RESUMO

Quercetin (3,5,7,3',4'-pentahydroxyflavone) is a flavone with putative ability to prevent cancer and cardiovascular diseases. Its metabolism was evaluated in rats and human. Rats received quercetin via the intravenous (i.v.) route and metabolites were isolated from the plasma, urine and bile. Analysis was by high-performance liquid chromatography and confirmation of species identity was achieved by mass spectrometry. Quercetin and isorhamnetin, the 3'-O-methyl analogue, were found in both the plasma and urine. In addition, several polar peaks were characterised as sulphated and glucuronidated conjugates of quercetin and isorhamnetin. Extension of the metabolism studies to a cancer patient who had received quercetin as an i.v. bolus showed that (Quercetin removed) isorhamnetin and quercetin 3'-O-sulphate were major plasma metabolites. As a catechol, quercetin can potentially be converted to a quinone and subsequently conjugated with glutathione (GSH). Oxidation of quercetin with mushroom tyrosinase in the presence of GSH furnished GSH conjugates of quercetin, two mono- and one bis-substituted conjugates. However, these species were not found in biomatrices in rats treated with quercetin. As cyclo-oxygenase-2 (COX-2) expression is mechanistically linked to carcinogenesis, we examined whether quercetin and its metabolites can inhibit COX-2 in a human colorectal cancer cell line (HCA-7). Isorhamnetin and its 4'-isomer tamarixetin were potent inhibitors, reflected in a 90% decrease in prostaglandin E-2 (PGE-2) levels, a marker of COX-2 activity. Quercetin was less effective, with a 50% decline. Quercetin 3- and 7-O-sulphate had no effect on PGE-2. The results indicate that quercetin may exert its pharmacological effects, at least in part, via its metabolites.


Assuntos
Prostaglandina-Endoperóxido Sintases/metabolismo , Quercetina/farmacologia , Animais , Anticarcinógenos/sangue , Anticarcinógenos/farmacocinética , Anticarcinógenos/farmacologia , Transporte Biológico , Cromatografia Líquida de Alta Pressão , Dinoprostona/metabolismo , Humanos , Masculino , Quercetina/sangue , Quercetina/farmacocinética , Ratos , Ratos Endogâmicos F344
14.
Cell Death Differ ; 9(9): 881-92, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12181739

RESUMO

Ligation of death receptors or formation of the Apaf-1 apoptosome results in the activation of caspases and execution of apoptosis. We recently demonstrated that X-linked inhibitor-of-apoptosis protein (XIAP) associates with the apoptosome in vitro. By utilizing XIAP mutants, we now report that XIAP binds to the 'native' apoptosome complex via a specific interaction with the small p12 subunit of processed caspase-9. Indeed, we provide the first direct evidence that XIAP can simultaneously bind active caspases-9 and -3 within the same complex and that inhibition of caspase-3 by the Linker-BIR2 domain prevents disruption of BIR3-caspase-9 interactions. Recent studies suggest that inhibition of caspase-3 is dispensable for its anti-apoptotic effects. However, we clearly demonstrate that inhibition of caspase-3 is required to inhibit CD95 (Fas/Apo-1)-mediated apoptosis, whereas inhibition of either caspase-9 or caspase-3 prevents Bax-induced cell death. Finally, we illustrate for the first time that XIAP mutants, which are incapable of binding to caspases-9 and -3 are completely devoid of anti-apoptotic activity. Thus, XIAP's capacity to maintain inhibition of caspase-9 within the Apaf-1 apoptosome is influenced by its ability to simultaneously inhibit active caspase-3, and depending upon the apoptotic stimulus, inhibition of caspase-9 or 3 is essential for XIAP's anti-apoptotic activity.


Assuntos
Apoptose/fisiologia , Caspases/metabolismo , Células Eucarióticas/enzimologia , Proteínas/genética , Proteínas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2 , Proteínas Proto-Oncogênicas/metabolismo , Receptor fas/metabolismo , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose , Fator Apoptótico 1 Ativador de Proteases , Sítios de Ligação/genética , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Transporte/metabolismo , Caspase 3 , Caspase 9 , Células Cultivadas , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Inibidores Enzimáticos/farmacologia , Células Eucarióticas/citologia , Células Eucarióticas/efeitos dos fármacos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas Mitocondriais/metabolismo , Modelos Biológicos , Complexos Multienzimáticos/genética , Complexos Multienzimáticos/metabolismo , Mutação/genética , Complexo de Endopeptidases do Proteassoma , Transdução de Sinais/genética , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X , Proteína X Associada a bcl-2
15.
Am J Pathol ; 159(2): 623-30, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11485920

RESUMO

Adenomyosis is a fairly frequent disorder in adult women characterized by the haphazard location of endometrial glands and stroma deep within the myometrium of the uterus. This study compared the effects on uterine development of the selective estrogen receptor modulators, tamoxifen, toremifene, and raloxifene with estradiol when given orally to female mice on days 2 to 5 after birth. Uterine adenomyosis was found in all (14 of 14) mice dosed with tamoxifen and most mice (12 of 14) treated with toremifene, but in none of the vehicle-dosed controls, in only one animal treated with raloxifene at 42 and 90 days after dosing and in none of the mice treated with estradiol at 42 days. At 6 days, the uterus in the groups that developed a high incidence of adenomyosis showed histological evidence of disturbed differentiation of the myometrium. Gene-expression XY-scatterplots using Clontech mouse 1.2 Atlas mouse cDNA expression arrays analyzing total uterine RNA showed nerve growth factor-alpha, preadipocyte factor-1, and insulin-like growth factor-2 were key genes differentially modified by tamoxifen or toremifene treatment, relative to the controls. As these genes may play an important role in regulating differentiation and development of the myometrium, these data suggest that adenomyosis may be caused primarily by defects in the formation of the myometrium.


Assuntos
Endometriose/patologia , Estradiol/farmacologia , Miométrio/citologia , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Células Estromais/citologia , Útero/citologia , Administração Oral , Envelhecimento , Animais , Animais Recém-Nascidos , Peso Corporal/efeitos dos fármacos , Proteínas de Ligação ao Cálcio , Diferenciação Celular/efeitos dos fármacos , Estradiol/administração & dosagem , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Inibidores do Crescimento/genética , Fator de Crescimento Insulin-Like II/genética , Peptídeos e Proteínas de Sinalização Intercelular , Proteínas de Membrana/genética , Camundongos , Miométrio/efeitos dos fármacos , Miométrio/patologia , Fator de Crescimento Neural/genética , Análise de Sequência com Séries de Oligonucleotídeos , Tamanho do Órgão/efeitos dos fármacos , Cloridrato de Raloxifeno/farmacologia , Proteínas Repressoras/genética , Células Estromais/efeitos dos fármacos , Células Estromais/patologia , Tamoxifeno/farmacologia , Toremifeno/farmacologia , Útero/efeitos dos fármacos , Útero/crescimento & desenvolvimento
16.
J Endocrinol ; 170(3): 555-64, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11524235

RESUMO

This study compares the actions of oestradiol, tamoxifen, toremifene and raloxifene on enzyme and gene expression in uterine tissues of ovariectomised rats over 72 h. The time-course for the induction of ornithine decarboxylase by the compounds showed a rapid biphasic response, while for creatine kinase brain type (BB) there was a continued increase over 72 h. The efficacy of induction showed that, with both markers, oestradiol gave the highest induction level, followed by tamoxifen or toremifene and then raloxifene. RT-PCR demonstrated that all compounds decreased oestrogen receptor (ER) alpha, ERbeta and ERbeta2 gene expression, 8-24 h after the first dose, suggesting that down-regulation of ER is not the primary cause of the difference in efficacy between these compounds. Using cDNA arrays, expression of 512 genes was examined in the uteri of oestradiol- or tamoxifen-treated rats. Both compounds resulted in the up-regulation of heat-shock protein 27, telomerase-associated protein 1 and secretin. However, most surprising was the marked down-regulation of Wilms' tumour and retinoblastoma genes. We speculate that this may result in a loss of regulation of the transition from the G1 to the S phase in the cell cycle and may make cells more vulnerable to the carcinogenic effects of tamoxifen in this tissue.


Assuntos
Antineoplásicos Hormonais/farmacologia , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Útero/efeitos dos fármacos , Animais , Técnicas de Cultura de Células , Creatina Quinase/metabolismo , Creatina Quinase Forma BB , Relação Dose-Resposta a Droga , Estradiol/farmacologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Isoenzimas/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Ornitina Descarboxilase/metabolismo , Ovariectomia , Cloridrato de Raloxifeno/farmacologia , Ratos , Ratos Wistar , Receptores de Estrogênio/efeitos dos fármacos , Receptores de Estrogênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tamoxifeno/farmacologia , Toremifeno/farmacologia , Útero/enzimologia
17.
Am J Physiol Cell Physiol ; 281(2): C624-32, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11443062

RESUMO

A6 model renal epithelial cells were stably transfected with enhanced green fluorescent protein (EGFP)-tagged alpha- or beta-subunits of the epithelial Na(+) channel (ENaC). Transfected RNA and proteins were both expressed in low abundance, similar to the endogenous levels of ENaC in native cells. In living cells, laser scanning confocal microscopy revealed a predominantly subapical distribution of EGFP-labeled subunits, suggesting a readily accessible pool of subunits available to participate in Na(+) transport. The basal level of Na(+) transport in the clonal lines was enhanced two- to fourfold relative to the parent line. Natriferic responses to insulin or aldosterone were similar in magnitude to the parent line, while forskolin-stimulated Na(+) transport was 64% greater than control in both the alpha- and beta-transfected lines. In response to forskolin, EGFP-labeled channel subunits traffic to the apical membrane. These data suggest that channel regulators, not the channel per se, form the rate-limiting step in response to insulin or aldosterone stimulation, while the number of channel subunits is important for basal as well as cAMP-stimulated Na(+) transport.


Assuntos
Células Epiteliais/metabolismo , Canais de Sódio/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Linhagem Celular , Membrana Celular/metabolismo , Células Clonais , Colforsina/farmacologia , Células Epiteliais/ultraestrutura , Canais Epiteliais de Sódio , Proteínas de Fluorescência Verde , Indicadores e Reagentes , Proteínas Luminescentes , Microscopia Confocal , Isoformas de Proteínas/metabolismo , Distribuição Tecidual , Xenopus
18.
Pharm Res ; 18(5): 640-5, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11465419

RESUMO

PURPOSE: Nanoparticles can be utilised for targeting drugs to the regional lymph nodes or as diagnostic agents. The surface modification of magnetite nanospheres with poly(ethylene glycol) (PEG) has been assessed by in vitro characterisation and in vivo studies following subcutaneous administration to the rat. METHODS: Magnetite nanospheres were prepared with a grafted PEG layer using various PEG lengths from 350 to 1,000 Da. Thermogravimetric analysis was utilised to measure the adsorbed amount of PEG. Colloid stability was confirmed by measurement of the particle size and electrophoretic mobility. The kinetics of injection site drainage and lymph node retention were determined 2 hours after subcutaneous administration, for nanospheres coated with PEG lengths of 350, 550. 750, and 1,000 Da. For the 750 PEG coated nanospheres, the kinetics of distribution was determined over a 48-hour time course. RESULTS: The distribution of the nanospheres was modified and the lymph node localisation enhanced by altering the surface coverage of PEG on the magnetic surface. CONCLUSIONS: PEG-coated magnetite nanospheres with different surface characteristics can be utilised to target a diagnostic agent to regional lymph nodes.


Assuntos
Meios de Contraste , Ferro , Linfonodos/patologia , Imageamento por Ressonância Magnética/métodos , Polietilenoglicóis , Animais , Fenômenos Químicos , Físico-Química , Coloides , Meios de Contraste/química , Meios de Contraste/farmacocinética , Dextranos , Excipientes , Ferro/química , Ferro/farmacocinética , Radioisótopos de Ferro , Masculino , Tamanho da Partícula , Polietilenoglicóis/química , Polietilenoglicóis/farmacocinética , Ratos , Ratos Wistar , Silanos , Propriedades de Superfície , Distribuição Tecidual
19.
Microsurgery ; 21(2): 52-4, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11288152

RESUMO

We report a case of microsurgical replantation of traumatic self-amputation of penis after prolonged warm ischemia as a result of delayed presentation. At 12 weeks postoperative follow-up evaluation, the patient exhibited good urinary flow, spontaneous erection, and a normal response to pharmacological stimulation.


Assuntos
Pênis/cirurgia , Reimplante , Humanos , Masculino , Microcirurgia/métodos , Pessoa de Meia-Idade , Pênis/irrigação sanguínea , Pênis/lesões , Automutilação , Ultrassonografia Doppler
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