Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 141
Filtrar
1.
Clin Oncol (R Coll Radiol) ; 36(6): 343-352, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38553362

RESUMO

AIMS: Despite relatively favourable outcomes associated with IDH-mutant grade 3 gliomas, many patients present with diffuse non-enhancing disease involving multiple brain regions, prompting concern over both durable disease control and the morbidity associated with large volume radiation therapy. This study audits volumetric response, survival and functional outcomes in this 'large volume' subgroup that undergoes intensity modulated radiation therapy (IMRT). MATERIALS AND METHODS: From a prospective database of 187 patients with IDH-mutant grade 3 gliomas managed with IMRT between 2008 and 2020, recorded PTV was divided into quartiles. The top quartile, termed the 'large volume cohort' (LVC), was identified. IMRT involved FET-FDG guided integrated boost (59.4/54Gy in 33 fractions). Manual volumetric segmentation of baseline, four months and 13 months post-IMRT tumour were performed for T1, T2 and T1gd MRI sequences. The primary endpoint was volumetric reduction on the T1 and T2 sequences at 13 months and analysed with relapse-free survival (RFS) and overall survival (OS). Morbidity endpoints were assessed at year four post-IMRT and included performance status (ECOG PS) and employment outcomes. RESULTS: The fourth quartile (LVC) identified 44 patients for whom volumetric analysis was available. The LVC had median PTV of 320cm3 compared to 186.2cm3 for the total group. Anaplastic astrocytoma and oligodendroglioma were equally distributed and tumour sites were frontal (54%), temporal (18%) and parietal lobes (16%). Median follow-up for survivors was 71.5 months. Projected 10-year RFS and OS in LVC was 40% and 62%, compared to 53% and 62% respectively in the overall cohort. The RFS (p = 0.06) and OS (p = 0.65) of the LVC was not significantly different to other PTV quartiles; however the impact of PTV volume reached significance when analysed as a continuous variable (RFS p < 0.01; OS p = 0.02). Median T1 volumes were 26.1cm3, 8.0cm3 and 5.3cm3 at months +0, +3 and +12, respectively. The corresponding T2 volumes were 120.8cm3, 29.1cm3 and 26.3cm3. The median T1 and T2 volume reductions were 77% (q1-3: 57-92%) and 78% (q1-3: 60-85%) at 13 months post-IMRT. Initial T2 volume was associated with worse RFS (p = 0.04) but not OS (p = 0.96). There was no association between median T2 volume reduction and RFS (p = 0.77). For patients assessable at year 4 post-IMRT, no late CTCAE Grade 3/4 toxicity events were recognised. 92% of patients were ECOG PS 0-1, 45% were employed at prior capacity and 28% were working with impairment. CONCLUSION: Patients with large volume IDH-mutant Grade 3 glioma demonstrated significant tumour reduction post-IMRT, and good long-term outcomes with respect to survival and functional status. Although larger IMRT volumes were associated with poorer RFS, this was also associated with the initial volume of non-enhancing tumour.


Assuntos
Neoplasias Encefálicas , Fluordesoxiglucose F18 , Glioma , Isocitrato Desidrogenase , Radioterapia de Intensidade Modulada , Humanos , Masculino , Feminino , Radioterapia de Intensidade Modulada/métodos , Pessoa de Meia-Idade , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/genética , Glioma/radioterapia , Glioma/patologia , Glioma/diagnóstico por imagem , Glioma/genética , Glioma/mortalidade , Isocitrato Desidrogenase/genética , Adulto , Idoso , Mutação , Estudos Prospectivos , Compostos Radiofarmacêuticos/uso terapêutico , Gradação de Tumores
2.
Radiography (Lond) ; 30(1): 332-339, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38128249

RESUMO

INTRODUCTION: The purpose of this study was to assess the sexuality of cervical cancer patients undergoing radiotherapy at a major cancer treatment center in Ghana. This is an area of interest as globally; cervical cancer kills approximately 342,000 people per annum with an estimated number of 604,000 new cases in 2020. Acknowledging the World Health Organization's definition of sexual health as a state of physical, mental and social well-being in relation to sexuality, this paper sheds light on how these dimensions affect the quality of life of cervical cancer patients. METHODS: This was a longitudinal study, which assessed the impact of radiotherapy on the sexuality of both premenopausal and postmenopausal cervical cancer patients presenting for primary treatment with chemoradiation from April to July, 2021 at a major cancer treatment centre in Ghana. The Female Sexual Function Index and Body Image Scale questionnaires were respectively used to evaluate the sexual functions scores among the cervical cancer patients, and to assess the impact of the treatment on their body image. MATLAB software was used for data analysis. RESULTS: Most of the cervical cancer patients sampled were postmenopausal (57 %). About 79 % premenopausal and 96 % postmenopausal cervical cancer patients were sexually inactive during radiotherapy (day 15). Also, 48 % premenopausal and 24 % postmenopausal patients were very dissatisfied with their bodies at the onset of treatment. The frequency of orgasm in cervical cancer patients declined after treatment causing a deterioration in their sexual function. The patients' sexuality was influenced by age and menopausal status. The decreased sexual desire of the patients resulted in emotional distancing from their partners, which invariably induced changes in their partners' level of sexual interest. This study established significant differences between premenopausal and postmenopausal cervical cancer patients who were generally very dissatisfied with their sexual relationships with their partners on day 1 (p = 0.02) and on day 15 (p = 0.00) of treatment. CONCLUSION: The majority of patients who presented for treatment for cervical cancer in this study were postmenopausal. Their interest in sexual activity was more influenced by their menopausal status than their antineoplastic treatment. This study indicates that cervical cancer patients are more likely to develop sexual health problems which could substantially worsen over the course of their treatment and beyond. IMPLICATION FOR PRACTICE: The study will contribute within the oncology team by assisting personnel in putting in place measures that will guide the treatment of cervical cancer patients and improve quality of care.


Assuntos
Qualidade de Vida , Neoplasias do Colo do Útero , Feminino , Humanos , Estudos Longitudinais , Neoplasias do Colo do Útero/radioterapia , Gana/epidemiologia , Comportamento Sexual , Sexualidade/psicologia
3.
Ann Oncol ; 32(2): 208-217, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33246021

RESUMO

BACKGROUND: Activation of the phosphatidylinositol-3-kinase (PI3K) pathway via PIK3CA mutations occurs in 28%-46% of hormone receptor-positive (HR+), human epidermal growth factor receptor-2-negative (HER2-) advanced breast cancers (ABCs) and is associated with poor prognosis. The SOLAR-1 trial showed that the addition of alpelisib to fulvestrant treatment provided statistically significant and clinically meaningful progression-free survival (PFS) benefit in PIK3CA-mutated, HR+, HER2- ABC. PATIENTS AND METHODS: Men and postmenopausal women with HR+, HER2- ABC whose disease progressed on or after aromatase inhibitor (AI) were randomized 1 : 1 to receive alpelisib (300 mg/day) plus fulvestrant (500 mg every 28 days and once on day 15) or placebo plus fulvestrant. Overall survival (OS) in the PIK3CA-mutant cohort was evaluated by Kaplan-Meier methodology and a one-sided stratified log-rank test was carried out with an O'Brien-Fleming efficacy boundary of P ≤ 0.0161. RESULTS: In the PIK3CA-mutated cohort (n = 341), median OS [95% confidence interval (CI)] was 39.3 months (34.1-44.9) for alpelisib-fulvestrant and 31.4 months (26.8-41.3) for placebo-fulvestrant [hazard ratio (HR) = 0.86 (95% CI, 0.64-1.15; P = 0.15)]. OS results did not cross the prespecified efficacy boundary. Median OS (95% CI) in patients with lung and/or liver metastases was 37.2 months (28.7-43.6) and 22.8 months (19.0-26.8) in the alpelisib-fulvestrant and placebo-fulvestrant arms, respectively [HR = 0.68 (0.46-1.00)]. Median times to chemotherapy (95% CI) for the alpelisib-fulvestrant and placebo-fulvestrant arms were 23.3 months (15.2-28.4) and 14.8 months (10.5-22.6), respectively [HR = 0.72 (0.54-0.95)]. No new safety signals were observed with longer follow-up. CONCLUSIONS: Although the analysis did not cross the prespecified boundary for statistical significance, there was a 7.9-month numeric improvement in median OS when alpelisib was added to fulvestrant treatment of patients with PIK3CA-mutated, HR+, HER2- ABC. Overall, these results further support the statistically significant prolongation of PFS observed with alpelisib plus fulvestrant in this population, which has a poor prognosis due to a PIK3CA mutation. CLINICALTRIALS. GOV ID: NCT02437318.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias da Mama , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Classe I de Fosfatidilinositol 3-Quinases/genética , Feminino , Fulvestranto , Humanos , Masculino , Receptor ErbB-2/genética , Receptores de Estrogênio/genética , Tiazóis
4.
Ann Oncol ; 31(8): 1001-1010, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32416251

RESUMO

BACKGROUND: Alpelisib (α-selective phosphatidylinositol 3-kinase inhibitor) plus fulvestrant is approved in multiple countries for men and postmenopausal women with PIK3CA-mutated, hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer following progression on or after endocrine therapy. A detailed understanding of alpelisib's safety profile should inform adverse event (AE) management and enhance patient care. PATIENTS AND METHODS: AEs in the phase III SOLAR-1 trial were assessed in patients with and without PIK3CA mutations. The impact of protocol-specified AE-management recommendations was evaluated, including an amendment to optimize hyperglycemia and rash management. RESULTS: Patients were randomly assigned to receive fulvestrant plus alpelisib (n = 284) or placebo (n = 287). The most common grade 3/4 AEs with alpelisib were hyperglycemia (grade 3, 32.7%; grade 4, 3.9%), rash (grade 3, 9.9%), and diarrhea (grade 3, 6.7%). Median time to onset of grade ≥3 toxicity was 15 days (hyperglycemia, based on fasting plasma glucose), 13 days (rash), and 139 days (diarrhea). Metformin alone or in combination with other antidiabetic agents was used by most patients (87.1%) with hyperglycemia. Preventive anti-rash medication resulted in lower incidence (any grade, 26.7% versus 64.1%) and severity of rash (grade 3, 11.6% versus 22.7%) versus no preventative medication. Discontinuations due to grade ≥3 AEs were lower following more-detailed AE management guidelines (7.9% versus 18.1% previously). Patients with PIK3CA mutations had a median alpelisib dose intensity of 248 mg/day. Median progression-free survival with alpelisib was 12.5 and 9.6 months for alpelisib dose intensities of ≥248 mg/day and <248 mg/day, respectively, compared with 5.8 months with placebo. CONCLUSIONS: Hyperglycemia and rash occurred early during alpelisib treatment, while diarrhea occurred at a later time point. Early identification, prevention, and intervention, including concomitant medications and alpelisib dose modifications, resulted in less severe toxicities. Reductions in treatment discontinuations and improved progression-free survival at higher alpelisib dose intensities support the need for optimal AE management. CLINICALTRIALS. GOV ID: NCT02437318.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias da Mama , Fosfatidilinositol 3-Quinases , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias da Mama/tratamento farmacológico , Feminino , Fulvestranto , Humanos , Masculino , Receptor ErbB-2 , Receptores de Estrogênio , Tiazóis
5.
Mol Aspects Med ; 61: 41-49, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29317252

RESUMO

The gastrointestinal (GI) tract plays a central role in the absorption, distribution, metabolism, and excretion of flavonoids, which ultimately define the health effects of these bioactives. These aspects are modulated by the interactions of flavonoids with other dietary components, environmental factors, the host, and the GI microbiota. Flavonoid can target molecules in the luminal content, the different GI tract cell types, and the microbiota. Importantly, flavonoid actions at the GI tract can have an impact systemically, e.g. on glucose homeostasis, lipid and energy metabolism, or cardiovascular risk factors. The beneficial actions of flavonoids at the GI include their capacity to: i) protect the intestinal epithelium against pharmacological insults and food toxins; ii) modulate the activity of enzymes involved in lipid and carbohydrate absorption; iii) maintain the intestinal barrier integrity; iv) modulate the secretion of gut hormones; v) modulate the GI tract immune system; vi) exert potential anti-colorectal cancer activity; and vii) shape microbiota composition and function. Further understanding of the mechanisms mediating the effects of flavonoids on the intestine (and its microbiota) is of critical importance given the relevance of the GI tract on sustaining overall health and of the widespread recommendations of increasing the intake of plant bioactives.


Assuntos
Flavonoides/metabolismo , Trato Gastrointestinal/metabolismo , Gastroenteropatias/metabolismo , Gastroenteropatias/microbiologia , Gastroenteropatias/patologia , Microbioma Gastrointestinal , Trato Gastrointestinal/microbiologia , Trato Gastrointestinal/patologia , Saúde , Humanos
6.
J Anat ; 225(4): 436-46, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25132002

RESUMO

High density mineralised protrusions (HDMP) from the tidemark mineralising front into hyaline articular cartilage (HAC) were first described in Thoroughbred racehorse fetlock joints and later in Icelandic horse hock joints. We now report them in human material. Whole femoral heads removed at operation for joint replacement or from dissection room cadavers were imaged using magnetic resonance imaging (MRI) dual echo steady state at 0.23 mm resolution, then 26-µm resolution high contrast X-ray microtomography, sectioned and embedded in polymethylmethacrylate, blocks cut and polished and re-imaged with 6-µm resolution X-ray microtomography. Tissue mineralisation density was imaged using backscattered electron SEM (BSE SEM) at 20 kV with uncoated samples. HAC histology was studied by BSE SEM after staining block faces with ammonium triiodide solution. HDMP arise via the extrusion of an unknown mineralisable matrix into clefts in HAC, a process of acellular dystrophic calcification. Their formation may be an extension of a crack self-healing mechanism found in bone and articular calcified cartilage. Mineral concentration exceeds that of articular calcified cartilage and is not uniform. It is probable that they have not been reported previously because they are removed by decalcification with standard protocols. Mineral phase morphology frequently shows the agglomeration of many fine particles into larger concretions. HDMP are surrounded by HAC, are brittle, and show fault lines within them. Dense fragments found within damaged HAC could make a significant contribution to joint destruction. At least larger HDMP can be detected with the best MRI imaging ex vivo.


Assuntos
Calcinose/patologia , Cartilagem Articular/patologia , Osteoartrite/patologia , Cadáver , Feminino , Impacto Femoroacetabular , Cabeça do Fêmur/patologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Microtomografia por Raio-X
8.
Biofabrication ; 5(1): 015004, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23220789

RESUMO

Short-term cell-substrate interactions of two secondary chondrocyte cell lines (human chondrosarcoma cells, canine chondrocytes) with layer-by-layer self-assembled multilayer nanofilms were investigated for a better understanding of cellular-behaviour dependence on a number of nanofilm layers. Cell-substrate interactions were studied on polyelectrolyte multilayer nanofilms (PMNs) of eleven different biomaterials. Surface characterization of PMNs performed using AFM showed increasing surface roughness with increasing number of layers for most of the biomaterials. LDH-L and MTT assays were performed on chondrosarcoma cells and canine chondrocytes, respectively. A major observation was that 10-bilayer nanofilms exhibited lesser cytotoxicity towards human chondrosarcoma cells than their 5-bilayer counterparts. In the case of canine chondrocytes, BSA enhanced cell metabolic activity with increasing number of layers, underscoring the importance of the multilayer nanofilm architecture on cellular behaviour.


Assuntos
Materiais Biocompatíveis/química , Comunicação Celular , Condrócitos/citologia , Condrossarcoma/fisiopatologia , Nanoestruturas/química , Neoplasias de Tecido Conjuntivo/fisiopatologia , Engenharia Tecidual/instrumentação , Animais , Proliferação de Células , Sobrevivência Celular , Condrócitos/química , Cães , Humanos , Alicerces Teciduais/química
10.
J Biol Chem ; 276(52): 49320-30, 2001 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-11604408

RESUMO

Members of the human serpin family regulate a diverse array of serine and cysteine proteinases associated with essential biological processes such as fibrinolysis, coagulation, inflammation, cell mobility, cellular differentiation, and apoptosis. Most serpins are secreted and attain physiologic concentrations in the blood and extracellular fluids. However, a subset of the serpin superfamily, the ov-serpins, also resides intracellularly. Using high throughput genomic sequence, we identified a novel member of the human ov-serpin gene family, SERPINB12. The gene mapped to the ov-serpin cluster at 18q21 and resided between SERPINB5 (maspin) and SERPINB13 (headpin). The presence of SERPINB12 in silico was confirmed by cDNA cloning. Expression studies showed that SERPINB12 was expressed in many tissues, including brain, bone marrow, lymph node, heart, lung, liver, pancreas, testis, ovary, and intestines. Based on the presence of Arg and Ser at the reactive center of the RSL, SERPINB12 appeared to be an inhibitor of trypsin-like serine proteinases. This hypothesis was confirmed because recombinant SERPINB12 inhibited human trypsin and plasmin but not thrombin, coagulation factor Xa, or urokinase-type plasminogen activator. The second-order rate constants for the inhibitory reactions were 2.5 +/- 1.6 x 10(5) and 1.6 +/- 0.2 x 10(4) M(-1) S(-1), respectively. These data show that SERPINB12 encodes for a new functional member of the human ov-serpin family.


Assuntos
Inibidores de Serina Proteinase/metabolismo , Serpinas/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Humanos , Dados de Sequência Molecular , Família Multigênica , Desnaturação Proteica , Proteínas Recombinantes de Fusão/metabolismo , Alinhamento de Sequência , Inibidores de Serina Proteinase/química , Inibidores de Serina Proteinase/genética , Serpinas/química , Serpinas/genética , Distribuição Tecidual
13.
J Pharmacol Exp Ther ; 296(1): 198-206, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11123381

RESUMO

Naturally occurring isothiocyanates, such as benzyl isothiocyanate (BITC), are potent and selective inhibitors of carcinogenesis induced by a variety of chemical carcinogens. These effects appear to be mediated through favorable modification of both phase I and II enzymes involved in carcinogen metabolism. The inactivation of rat and human cytochromes P450 (P450s) in microsomes and the reconstituted system by BITC was investigated. BITC is a mechanism-based inactivator of rat P450s 1A1, 1A2, 2B1, and 2E1, as well as human P450s 2B6 and 2D6. BITC was most effective in inactivating P450s 2B1, 2B6, 1A1, and 2E1, whereas the activities of human P450 2C9 and rat P450 3A2 were not altered. The concentrations required for half-maximal inactivation (K(I)) of P450s 1A1, 1A2, 2B1, and 2E1 were 35, 28, 16, and 18 microM, respectively. The corresponding values for k(inact) were 0.26, 0.09, 0.18, and 0.05 min(-1), respectively. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of P450 2B1 inactivated by [(14)C]BITC indicated specific and covalent modification of the P450 apoprotein by a metabolite of BITC. High-performance liquid chromatography analysis of the BITC metabolites revealed that benzylamine was the major metabolite and there were lesser amounts of benzoic acid, benzaldehyde, N,N'-di-benzylurea, and N,N'-di-benzylthiourea. Presumably, BITC was metabolized to the reactive benzyl isocyanate intermediate that covalently modified the P450 apoprotein or hydrolyzed to form benzylamine. BITC was an efficient inactivator of P450 2B1 with a partition ratio of approximately 11:1. This irreversible inactivation of P450s by BITC could contribute significantly to its chemopreventative action.


Assuntos
Anticarcinógenos/farmacologia , Citocromo P-450 CYP2B1/antagonistas & inibidores , Inibidores das Enzimas do Citocromo P-450 , Isotiocianatos/farmacologia , Animais , Citocromo P-450 CYP2B1/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Eletroforese em Gel de Poliacrilamida , Humanos , Técnicas In Vitro , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Isotiocianatos/metabolismo , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/enzimologia , NADPH-Ferri-Hemoproteína Redutase/metabolismo , Ratos , Ratos Endogâmicos F344 , Ratos Long-Evans
14.
Biochemistry ; 39(45): 13781-7, 2000 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-11076517

RESUMO

The photoaffinity phosphate analogue 4-azido-2 nitrophenyl phosphate (ANPP) was shown previously (Pougeois, R., Lauquin, G. J.-M., and Vignais, P. V. (1983) Biochemistry 22, 1241-1245) to bind covalently and specifically to a single catalytic site on one of the three beta-subunits of the isolated chloroplast coupling factor 1 (CF(1)). Modification by ANPP strongly inhibited ATP hydrolysis activity. In this study, we examined labeling of membrane-bound CF(1) by ANPP by exposing thylakoid membranes to increasing concentrations of the reagent. ANPP exhibited saturable binding to two sites on CF(1), one on the beta-subunit and one on the alpha-subunit. Labeling by ANPP resulted in the complete inhibition of both ATP synthesis and ATP hydrolysis by the membrane-bound enzyme. Labeling of both sites by ANPP was reduced by more than 80% in the presence of P(i) (> or = 10 mM) and ATP (> or = 0.5 mM). ADP was less effective in competing with ANPP for binding, giving a maximum of approximately 35% inhibition at concentrations > or = 2 mM. ANPP-labeled tryptic peptides of the alpha-subunit were isolated and sequenced. The majority of the probe was contained in three peptides corresponding to residues Gln(173) to Arg(216), Gly(217) to Arg(253), and His(256) to Arg(272) of the alpha-subunit. In the mitochondrial F(1) (Abrahams, J. P., Leslie, A. G. W., Lutter, R., and Walker, J. E. (1994) Nature 370, 621-628), all three analogous peptides are located within the nucleotide binding pocket and within close proximity to the gamma-phosphate binding site. The data indicate, however, that the azidophenyl group of bound ANPP is oriented at approximately 180 degrees in the opposite direction to the adenine binding site with reference to the phosphate binding site on the alpha-subunit. The study has confirmed that ANPP is a bona fide phosphate analogue and suggests that it specifically targets the gamma-phosphate binding site within the nucleotide binding pockets on the alpha- and beta-subunits of CF(1). The study also indicates that in the resting state of the chloroplast F(1)-F(0) complex both the alpha- and beta-subunits are structurally asymmetric.


Assuntos
Azidas/metabolismo , Cloroplastos/enzimologia , Fosfatos/metabolismo , Marcadores de Fotoafinidade/metabolismo , ATPases Translocadoras de Prótons/química , Ligação Competitiva , Membranas Intracelulares/química , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Fotólise , Ligação Proteica , Estrutura Terciária de Proteína , ATPases Translocadoras de Prótons/metabolismo , Spinacia oleracea/enzimologia , Tilacoides/enzimologia
15.
Chem Biol ; 7(10): 793-803, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11033082

RESUMO

BACKGROUND: Glycogen synthase kinase-3 (GSK-3) is a serine/threonine protein kinase, the activity of which is inhibited by a variety of extracellular stimuli including insulin, growth factors, cell specification factors and cell adhesion. Consequently, inhibition of GSK-3 activity has been proposed to play a role in the regulation of numerous signalling pathways that elicit pleiotropic cellular responses. This report describes the identification and characterisation of potent and selective small molecule inhibitors of GSK-3. RESULTS: SB-216763 and SB-415286 are structurally distinct maleimides that inhibit GSK-3alpha in vitro, with K(i)s of 9 nM and 31 nM respectively, in an ATP competitive manner. These compounds inhibited GSK-3beta with similar potency. However, neither compound significantly inhibited any member of a panel of 24 other protein kinases. Furthermore, treatment of cells with either compound stimulated responses characteristic of extracellular stimuli that are known to inhibit GSK-3 activity. Thus, SB-216763 and SB-415286 stimulated glycogen synthesis in human liver cells and induced expression of a beta-catenin-LEF/TCF regulated reporter gene in HEK293 cells. In both cases, compound treatment was demonstrated to inhibit cellular GSK-3 activity as assessed by activation of glycogen synthase, which is a direct target of this kinase. CONCLUSIONS: SB-216763 and SB-415286 are novel, potent and selective cell permeable inhibitors of GSK-3. Therefore, these compounds represent valuable pharmacological tools with which the role of GSK-3 in cellular signalling can be further elucidated. Furthermore, development of similar compounds may be of use therapeutically in disease states associated with elevated GSK-3 activity such as non-insulin dependent diabetes mellitus and neurodegenerative disease.


Assuntos
Aminofenóis/farmacologia , Proteínas Quinases Dependentes de Cálcio-Calmodulina/antagonistas & inibidores , Regulação da Expressão Gênica/efeitos dos fármacos , Glicogênio/metabolismo , Indóis/farmacologia , Maleimidas/farmacologia , Transativadores , Transcrição Gênica/efeitos dos fármacos , Trifosfato de Adenosina/antagonistas & inibidores , Trifosfato de Adenosina/farmacologia , Ligação Competitiva , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Linhagem Celular , Proteínas do Citoesqueleto/genética , Diabetes Mellitus Tipo 2/tratamento farmacológico , Ativação Enzimática/efeitos dos fármacos , Genes Reporter , Glicogênio/biossíntese , Glicogênio Sintase/metabolismo , Quinase 3 da Glicogênio Sintase , Quinases da Glicogênio Sintase , Humanos , Cinética , Fígado/citologia , Fígado/efeitos dos fármacos , Fígado/enzimologia , Fígado/metabolismo , Estrutura Molecular , Doenças Neurodegenerativas/tratamento farmacológico , Proteínas Quinases/metabolismo , Proteínas Recombinantes , Transdução de Sinais/efeitos dos fármacos , beta Catenina
16.
Am J Physiol Lung Cell Mol Physiol ; 279(5): L967-76, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11053034

RESUMO

Apoptosis plays a central role in the cellular remodeling of the developing lung. We determined the spatiotemporal patterns of the cell death regulators Fas and Fas ligand (FasL) during rabbit lung development and correlated their expression with pulmonary and type II cell apoptosis. Fetal rabbit lungs (25-31 days gestation) were assayed for apoptotic activity by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) and DNA size analysis. Fas and FasL expression were analyzed by RT-PCR, immunoblot, and immunohistochemistry. Type II cell apoptosis increased significantly on gestational day 28; the type II cell apoptotic index increased from 0.54 +/- 0.34% on gestational day 27 to 3.34 +/- 1.24% on day 28, P < 0.01 (ANOVA). This corresponded with the transition from the canalicular to the terminal sac stage of development. The day 28 rise in epithelial apoptosis was synchronous with a robust if transient 20-fold increase in FasL mRNA and a threefold increase in FasL protein levels. In contrast, Fas mRNA levels remained constant, suggestive of constitutive expression. Fas and FasL proteins were immunolocalized to alveolar type II cells and bronchiolar Clara cells. The correlation of this highly specific pattern of FasL expression with alveolar epithelial apoptosis and remodeling implicates the Fas/FasL system as a potentially important regulatory pathway in the control of postcanalicular alveolar cytodifferentiation.


Assuntos
Apoptose , Desenvolvimento Embrionário e Fetal/fisiologia , Pulmão/embriologia , Glicoproteínas de Membrana/genética , Alvéolos Pulmonares/embriologia , Animais , Proteína Ligante Fas , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Idade Gestacional , Pulmão/citologia , Gravidez , Alvéolos Pulmonares/citologia , Coelhos , Mucosa Respiratória/citologia , Mucosa Respiratória/embriologia , Receptor fas/genética
17.
J Synchrotron Radiat ; 7(Pt 2): 53-60, 2000 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-16609174

RESUMO

In the period of the late-1980s, before the construction of multi-GeV third-generation storage rings with their intense insertion-device sources, the perceived number one problem for X-ray instrumentation was proper cooling of the first optical element in the beamline. This article, first given as an acceptance speech for the Compton Award ceremony at the Advanced Photon Source, presents a somewhat historical and anecdotal overview of how cryogenically cooled monochromator optics have been developed to provide a monochromator cooling solution adequate for today's power levels. A series of workshops and international collaborations were the key components for the progress and final success of this development.

18.
Clin Orthop Relat Res ; (367): 210-5, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10546617

RESUMO

This study presents long term results of arthroplasty with posterior cruciate retention using the Total Condylar Knee implant. From 1976 to 1982, 139 patients had 159 knee arthroplasties using Total Condylar Knee prostheses. Sixty-three patients (72 knees) were available for followup at a minimum of 16 years (range, 16-21 years). The average age of the patients at the time of surgery was 61 years. There were 21 men and 42 women. Patients with 68 knees had osteoarthrosis, three had rheumatoid arthritis and one had posttraumatic arthritis. There were five delayed complications. One patient (one knee) underwent revision surgery and two patients (two knees) declined revision surgery because they were considered to be high surgical risks, as determined by their internists. The average preoperative score was 40.3 points and improved to 88.4 points at followup. Eighty-seven percent of the patients had a score equal to or more than 85 points at last evaluation. Prosthesis survivorship at 20 years was 98.6% for patients who had revision surgery. No femoral components were revised for aseptic loosening. Retention of the posterior cruciate in Total Condylar Knee prosthesis produces results comparable with the results of the original Total Condylar Knee prosthesis with cruciate sacrifice.


Assuntos
Artroplastia do Joelho , Prótese do Joelho , Adulto , Idoso , Idoso de 80 Anos ou mais , Artrite Reumatoide/cirurgia , Artroplastia do Joelho/métodos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/cirurgia , Falha de Prótese , Reoperação , Análise de Sobrevida
19.
Arch Dermatol ; 135(10): 1187-92, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10522665

RESUMO

CONTEXT: Each year tens of thousands of patients in the United States are treated with UV-B radiation or psoralen plus UV-A radiation (PUVA) for a variety of skin disorders. Although PUVA is generally considered more effective, it is also more toxic and more expensive. The degree of consensus among experts in prescribing these alternative treatments has not been quantified. OBJECTIVES: To quantify variation among specialty clinics in the type of ultraviolet therapy used to treat specific skin conditions and assess factors associated with the use of specific treatments. DESIGN: Survey conducted during two 2-week periods in the late fall of 1994 and early spring of 1995. SETTING: Thirty-nine specialty clinics in 17 US geographic areas in 14 states and Washington, DC. PARTICIPANTS: A total of 3401 patients treated with UV radiation one or more times. OUTCOME MEASURES: Type of UV therapy used and indications for treatment, age, sex, number of patients treated, and geographic location of each clinic. RESULTS: The proportion of patients at each center treated with PUVA ranged from 0% to 93% (mean, 41%). Clinic size and geographic location, demographic characteristics of the patients, and diagnosis did not explain these large intercenter differences. CONCLUSIONS: Among specialized clinics, there is little consistency in the use of alternative therapies, which differ substantially in safety and cost, but whose relative efficacy is not well quantified. There is a lack of consensus among experts about the circumstances in which the greater risks and costs of PUVA are outweighed by its possibly greater efficacy, especially in the treatment of psoriasis.


Assuntos
Coleta de Dados , Psoríase/radioterapia , Terapia Ultravioleta/estatística & dados numéricos , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Terapia PUVA , Psoríase/tratamento farmacológico
20.
Nature ; 397(6715): 176-80, 1999 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-9923682

RESUMO

Helicobacter pylori, one of the most common bacterial pathogens of humans, colonizes the gastric mucosa, where it appears to persist throughout the host's life unless the patient is treated. Colonization induces chronic gastric inflammation which can progress to a variety of diseases, ranging in severity from superficial gastritis and peptic ulcer to gastric cancer and mucosal-associated lymphoma. Strain-specific genetic diversity has been proposed to be involved in the organism's ability to cause different diseases or even be beneficial to the infected host and to participate in the lifelong chronicity of infection. Here we compare the complete genomic sequences of two unrelated H. pylori isolates. This is, to our knowledge, the first such genomic comparison. H. pylori was believed to exhibit a large degree of genomic and allelic diversity, but we find that the overall genomic organization, gene order and predicted proteomes (sets of proteins encoded by the genomes) of the two strains are quite similar. Between 6 to 7% of the genes are specific to each strain, with almost half of these genes being clustered in a single hypervariable region.


Assuntos
Genoma Bacteriano , Helicobacter pylori/genética , Úlcera Duodenal/microbiologia , Regulação Bacteriana da Expressão Gênica , Infecções por Helicobacter/microbiologia , Helicobacter pylori/classificação , Humanos , Dados de Sequência Molecular , Alinhamento de Sequência , Análise de Sequência de DNA , Especificidade da Espécie
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA