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1.
Clin Hemorheol Microcirc ; 73(1): 105-111, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31561351

RESUMO

INTRODUCTION: Multiparametric-Magnetic Resonance Imaging (mpMRI)-Ultrasound fusion guided biopsy (Fbx) has emerged as the new standard of risk stratification for prostate cancer (PCa) with superior detection rates of clinically significant PCa than randomized biopsy. In the present study, we evaluated patients with suspicion of clinically significant PCa on mpMRI, but histopathologically proven Gleason 6 PCa in Fbx. MATERIAL AND METHODS: Between 2015 and 2019, 849 patients underwent Fbx and concurrent systematic 12-core biopsy at our department. 234 patients were diagnosed with Gleason 6 PCa in either mpMRI-targeted and/or concurrent systematic biopsy. Patients were analyzed regarding PSA, mpMRI findings according to PI-RADS classification, histopathological results of Fbx and systematic 12-core biopsy. 99/234 patients were also analyzed in regards of histopathology of the whole-mount specimen of subsequent radical prostatectomy (RP). RESULTS: In 131/234 patients (56%), Gleason 6 PCa was detected in the mpMRI target. In 103/234 patients (44%), Gleason 6 PCa was detected in the concurrent systematic 12-core biopsy with negative mpMRI-targeted biopsy. Men with evidence of Gleason 6 in the mpMRI target had significantly higher amounts of overall positive biopsies (median 4 vs. 2, p < 0.001) and higher maximum tumor infiltration per biopsy core (30% vs. 20%, p < 0.001) compared to men with negative mpMRI-targeted biopsy. Detection of Gleason 6 in mpMRI Target lesions correlated significantly with the PI-RADS score (p < 0.001). Patients with positive mpMRI-target had significantly higher tumor infiltration in whole-mount specimen after prostatectomy (20% vs. 15%, p = 0.0026) compared to men without detection of Gleason 6 in mpMRI-targeted biopsy but in additional systematic biopsy. CONCLUSION: Detection of Gleason 6 PCa in mpMRI-targeted biopsy indicates higher tumor burden compared to detection of Gleason 6 PCa in concurrent systematic biopsy and negative mpMRI-targeted biopsy.


Assuntos
Biópsia Guiada por Imagem/métodos , Imageamento por Ressonância Magnética Multiparamétrica/métodos , Gradação de Tumores/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/patologia
2.
Urologe A ; 58(5): 524-528, 2019 May.
Artigo em Alemão | MEDLINE | ID: mdl-30859231

RESUMO

In the prostate-specific antigen (PSA) era, most prostate cancers (PCa) are diagnosed in a localized stage and a plethora of therapeutic options are warranted in different clinical settings and disease stages of localized PCa. In the current narrative review, we give an overview of the current controversies in the therapeutic landscape of localized PCa and focus on organ-sparing approaches, percutaneous radiotherapy, brachytherapy as well as retropubic and robot-assisted prostatectomy by summarizing studies that have been published within the last two years.


Assuntos
Braquiterapia/métodos , Prostatectomia/métodos , Neoplasias da Próstata/terapia , Biópsia , Humanos , Masculino , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/patologia
3.
Chem Commun (Camb) ; 53(8): 1405-1408, 2017 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-28079225

RESUMO

Supramolecular Pd2L4 cages (L = ligand) hold promise as drug delivery systems. With the idea of achieving targeted delivery of the metallacages to tumor cells, the bioconjugation of exo-functionalized self-assembled Pd2L4 cages to peptides following two different approaches is reported for the first time. The obtained bioconjugates were analyzed and identified by high-resolution mass spectrometry.


Assuntos
Pesquisa Biomédica , Compostos Organometálicos/química , Paládio/química , Peptídeos/química , Sistemas de Liberação de Medicamentos , Substâncias Macromoleculares/química , Espectrometria de Massas
4.
Allergy ; 70(12): 1545-52, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26296735

RESUMO

BACKGROUND: House dust mite (HDM) acts on the airway epithelium to induce airway inflammation in asthma. We previously showed that the ability of HDM to induce allergic sensitization in mice is related to airway epithelial CCL20 secretion. OBJECTIVE: As a disintegrin and metalloprotease (ADAM)s have been implicated in chemokine shedding, we sought to determine their involvement in HDM-induced release of chemokines, including CCL20, by airway epithelial cells. METHODS: We studied the effects of pharmacological ADAM inhibitors as well as ADAM10 and ADAM17 siRNA downregulation on chemokine release using (multiplex) ELISA in supernatants from HDM-exposed human bronchial epithelial 16HBE cells and primary normal human bronchial epithelial cells (NHBE) at 4-24 h. RESULTS: House dust) mite markedly increased CCL20 levels in both 16HBE and NHBE cells (16-24 h). In 16HBE cells, the HDM-induced increase was observed as early as 4 h upon exposure and the use of specific inhibitors indicated the involvement of ADAM10/17-mediated shedding. siRNA knockdown of ADAM10, but not of ADAM17, significantly reduced the HDM-induced release of CCL20 in both 16HBE and NHBE cells. A similar effect was observed for HDM-induced CCL2, CCL5, and CXCL8 release in NHBE cells. The HDM-induced increase in CCL20 levels was not affected by protein synthesis inhibitor cycloheximide nor protein transport inhibitor monensin, indicating that HDM induces surface shedding of chemokines. CONCLUSION: Our data show for the first time that ADAM10 activity contributes to HDM-induced shedding of chemokines, including CCL20. The ADAM10/CCL20 axis may be a target for novel therapeutic strategies in asthma.


Assuntos
Proteínas ADAM/imunologia , Secretases da Proteína Precursora do Amiloide/imunologia , Asma/imunologia , Quimiocina CCL20/metabolismo , Proteínas de Membrana/imunologia , Pyroglyphidae/imunologia , Hipersensibilidade Respiratória/imunologia , Mucosa Respiratória/imunologia , Proteínas ADAM/metabolismo , Proteína ADAM10 , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Antígenos de Dermatophagoides/imunologia , Asma/metabolismo , Western Blotting , Células Cultivadas , Quimiocina CCL20/imunologia , Humanos , Proteínas de Membrana/metabolismo , RNA Interferente Pequeno , Hipersensibilidade Respiratória/metabolismo , Mucosa Respiratória/metabolismo , Transfecção
5.
Scand J Med Sci Sports ; 23(4): 508-15, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22107250

RESUMO

The effect of a whey protein- and carbohydrate (CHO)-enriched diet on the rate of muscle glycogen resynthesis after a soccer match was examined. Sixteen elite soccer players were randomly assigned to a group ingesting a diet rich in carbohydrates and whey protein [CHO, protein, and fat content was 71, 21, and 8E%, respectively; high content of carbohydrates and whey protein (HCP), n = 9] or a group ingesting a normal diet (55, 18, and 26E%; control [CON], n = 7) during a 48-h recovery period after a soccer match. CON and three additional players carried out a 90- and 60-min simulated match without body contacts (SIM90 and SIM60). Muscle glycogen was lowered (P < 0.05) by 54, 48, 53, and 38% after the matches in CON, HCP, SIM90, and SIM60, respectively. Glycogen resynthesis during the first 48 h after the match was not different between CON and HCP, whereas glycogen resynthesis was slower (P < 0.05) during the first 24 h after SIM60 than SIM90 (2.88 ± 0.84 vs 4.32 ± 0.54 mmol/kg dw/h). In HCP, glycogen content in type II muscle fibers was still lowered 48 h after the match. In conclusion, glycogen resynthesis 48 h after a soccer match is not elevated by ingestion of a HCP diet. Furthermore, glycogen resynthesis does not appear to be impaired by body contacts during a match.


Assuntos
Carboidratos da Dieta/farmacologia , Gorduras na Dieta/farmacologia , Glicogênio/biossíntese , Proteínas do Leite/farmacologia , Músculo Esquelético/efeitos dos fármacos , Futebol , Adulto , Creatina Quinase/sangue , Creatina Quinase/efeitos dos fármacos , Glicogênio/metabolismo , Humanos , Masculino , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiologia , Mioglobina/sangue , Mioglobina/efeitos dos fármacos , Resistência Física/fisiologia , Futebol/fisiologia , Proteínas do Soro do Leite , Adulto Jovem
6.
Cell Death Dis ; 2: e148, 2011 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-21509038

RESUMO

Wild-type p53 has a major role in the response and execution of apoptosis after chemotherapy in many cancers. Although high levels of wild-type p53 and hardly any TP53 mutations are found in testicular cancer (TC), chemotherapy resistance is still observed in a significant subgroup of TC patients. In the present study, we demonstrate that p53 resides in a complex with MDM2 at higher cisplatin concentrations in cisplatin-resistant human TC cells compared with cisplatin-sensitive TC cells. Inhibition of the MDM2-p53 interaction using either Nutlin-3 or MDM2 RNA interference resulted in hyperactivation of the p53 pathway and a strong induction of apoptosis in cisplatin-sensitive and -resistant TC cells. Suppression of wild-type p53 induced resistance to Nutlin-3 in TC cells, demonstrating the key role of p53 for Nutlin-3 sensitivity. More specifically, our results indicate that p53-dependent induction of Fas membrane expression (∼threefold) and enhanced Fas/FasL interactions at the cell surface are important mechanisms of Nutlin-3-induced apoptosis in TC cells. Importantly, an analogous Fas-dependent mechanism of apoptosis upon Nutlin-3 treatment is executed in wild-type p53 expressing Hodgkin lymphoma and acute myeloid leukaemia cell lines. Finally, we demonstrate that Nutlin-3 strongly augmented cisplatin-induced apoptosis and cell kill via the Fas death receptor pathway. This effect is most pronounced in cisplatin-resistant TC cells.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos , Proteína Ligante Fas/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Neoplasias Testiculares/patologia , Proteína Supressora de Tumor p53/metabolismo , Receptor fas/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Sinergismo Farmacológico , Humanos , Imidazóis/farmacologia , Imunoprecipitação , Masculino , Mutação , Piperazinas/farmacologia , Ligação Proteica/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-mdm2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-mdm2/genética , Interferência de RNA , Transdução de Sinais/efeitos dos fármacos , Neoplasias Testiculares/metabolismo , Proteína Supressora de Tumor p53/genética , Regulação para Cima/efeitos dos fármacos , Receptor fas/genética
7.
Amino Acids ; 41(2): 271-90, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20640864

RESUMO

Matrix metalloproteases (MMPs) comprise a family of enzymes that cleave protein substrates based on a conserved mechanism involving activation of an active site-bound water molecule by a Zn(2+) ion. Although the catalytic domain of MMPs is structurally highly similar, there are many differences with respect to substrate specificity, cellular and tissue localization, membrane binding and regulation that make this a very versatile family of enzymes with a multitude of physiological functions, many of which are still not fully understood. Essentially, all members of the MMP family have been linked to disease development, notably to cancer metastasis, chronic inflammation and the ensuing tissue damage as well as to neurological disorders. This has stimulated a flurry of studies into MMP inhibitors as therapeutic agents, as well as into measuring MMP levels as diagnostic or prognostic markers. As with most protein families, deciphering the function(s) of MMPs is difficult, as they can modify many proteins. Which of these reactions are physiologically or pathophysiologically relevant is often not clear, although studies on knockout animals, human genetic and epigenetic, as well as biochemical studies using natural or synthetic inhibitors have provided insight to a great extent. In this review, we will give an overview of 23 members of the human MMP family and describe functions, linkages to disease and structural and mechanistic features. MMPs can be grouped into soluble (including matrilysins) and membrane-anchored species. We adhere to the 'MMP nomenclature' and provide the reader with reference to the many, often diverse, names for this enzyme family in the introduction.


Assuntos
Metaloproteinases da Matriz/metabolismo , Processamento de Proteína Pós-Traducional , Animais , Colágeno/metabolismo , Fibronectinas/metabolismo , Gelatina/metabolismo , Humanos , Metaloproteinases da Matriz/química , Metástase Neoplásica , Neoplasias/metabolismo , Neoplasias/patologia , Estrutura Terciária de Proteína , Proteoglicanas/metabolismo , Especificidade por Substrato
8.
Scand J Med Sci Sports ; 20 Suppl 3: 125-32, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21029199

RESUMO

The study examines fatigue in elite soccer played in hot conditions. High-profile soccer players (n=20) were studied during match play at ∼31 °C. Repeated sprint and jump performances were assessed in rested state and after a game and activity profile was examined. Additionally, heart rate (HR), blood lactate, muscle temperature and body mass changes were determined. Repeated sprint and jump performances were reduced (P<0.05) by 2.6% and 8.2%, respectively, after the game. The fatigue index in the repeated sprint test was 6.0±0.7% after the game compared with 1.7±1.0% at rest (P<0.05). High-intensity running was 57±4% lower (P<0.05) during the last 15-min interval of the game compared with the first 15-min period. No differences were observed in mean HR or blood lactates between halves. Muscle temperature was 40.5±0.4 °C after the first half, which was 0.8±0.2 °C higher (P<0.05) than after the second half. Net fluid loss during the game was >2% of the body mass. Correlations were observed between net-fluid loss and repeated sprint test fatigue index after the game (r=0.73, P<0.05) and Yo-Yo intermittent recovery, level 1 test performance and high-intensity running during the final 15 min of the game (r=0.51, P<0.05). The study provides direct evidence of compromised repeated sprint and jump performances induced by soccer match play and pronounced reduction in high-intensity running toward the end of an elite game played in a hot environment. This fatigue could be associated training status and hyperthermia/dehydration.


Assuntos
Meio Ambiente , Exposição Ambiental/efeitos adversos , Exercício Físico/fisiologia , Fadiga/etiologia , Temperatura Alta/efeitos adversos , Futebol/fisiologia , Adaptação Fisiológica , Análise de Variância , Índice de Massa Corporal , Comportamento Competitivo , Frequência Cardíaca , Transtornos de Estresse por Calor/etiologia , Transtornos de Estresse por Calor/prevenção & controle , Humanos , Masculino , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Estatística como Assunto , Estresse Fisiológico , Análise e Desempenho de Tarefas , Adulto Jovem
9.
Eur Respir J ; 29(4): 633-42, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17251228

RESUMO

Alveolar epithelial cell injury and recovery are important in the pathogenesis of oxidant-induced lung damage. The alveolar cell line A549 was used to study responses of proliferating and quiescent cells in culture to time- and dose-dependent hydrogen peroxide (H(2)O(2)) challenges. Recovery was monitored after 24 h of incubation in fresh medium with 10% serum. The adherent cells were counted and the resistance and recovery of the attached cells was assessed by appearance, by measuring the number of viable, apoptotic and necrotic cells using fluorescent-activated cell sorting, and by determining the intracellular free thiol content. A549 cells recovered from a 1-h challenge with up to 1 mM H(2)O(2) but could not sustain a more prolonged challenge (6 or 24 h) with 0.5 mM or 1.0 mM H(2)O(2). These more severe conditions resulted in: loss of cells by detachment from the plate surface; reduced numbers of viable cells primarily due to necrosis; and a strong reduction of the intracellular free thiol content. Quiescent cells proved to be more sensitive to oxidative stress than proliferating cells. Intracellular free thiol levels apparently play a decisive role in cell survival, preferentially protecting proliferating cells.


Assuntos
Células Epiteliais/metabolismo , Peróxido de Hidrogênio/farmacologia , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Relação Dose-Resposta a Droga , Humanos , Necrose , Oxidantes/metabolismo , Estresse Oxidativo , Oxigênio/metabolismo , Soroalbumina Bovina/metabolismo , Compostos de Sulfidrila/metabolismo , Fatores de Tempo , Traqueia/metabolismo
11.
J Chromatogr A ; 1120(1-2): 142-50, 2006 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-16574134

RESUMO

Discovery of biomarkers is a fast developing field in proteomics research. Liquid chromatography coupled on line to mass spectrometry (LC-MS) has become a powerful method for the sensitive detection, quantification and identification of proteins and peptides in biological fluids like serum. However, the presence of highly abundant proteins often masks those of lower abundance and thus generally prevents their detection and identification in proteomics studies. To perform future comparative analyses of samples from a serum bank of cervical cancer patients in a longitudinal and cross-sectional manner, methodology based on the depletion of high-abundance proteins followed by tryptic digestion and LC-MS has been developed. Two sample preparation methods were tested in terms of their efficiency to deplete high-abundance serum proteins and how they affect the repeatability of the LC-MS data sets. The first method comprised depletion of human serum albumin (HSA) on a dye ligand chromatographic and immunoglobulin G (IgG) on an immobilized Protein A support followed by tryptic digestion, fractionation by cation-exchange chromatography, trapping on a C18 column and reversed-phase LC-MS. The second method included depletion of the six most abundant serum proteins based on multiple immunoaffinity chromatography followed by tryptic digestion, trapping on a C18 column and reversed-phase LC-MS. Repeatability of the overall procedures was evaluated in terms of retention time and peak area for a selected number of endogenous peptides showing that the second method, besides being less time consuming, gave more repeatable results (retention time: <0.1% RSD; peak area: <30% RSD). Application of an LC-MS component detection algorithm followed by principal component analysis (PCA) enabled discrimination of serum samples that were spiked with horse heart cytochrome C from non-spiked serum and the detection of a concentration trend, which correlated to the amount of spiked horse heart cytochrome C to a level of 5 pmol cytochrome C in 2 microl original serum.


Assuntos
Proteínas Sanguíneas/análise , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas/métodos , Animais , Citocromos c/análise , Eletroforese em Gel de Poliacrilamida , Cavalos , Humanos , Resinas de Troca Iônica/química , Análise de Componente Principal/métodos , Proteoma/análise , Proteômica/métodos , Reprodutibilidade dos Testes , Tripsina/análise
13.
Eur Urol ; 48(6): 1031-41, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16054748

RESUMO

An overview is given of serum and urine prostate cancer markers that are currently under investigation and subsequently the P-Mark project is introduced. There are many markers showing promise to overcome the limitations of prostate specific antigen (PSA). Eventually, these markers should be able to increase the specificity in diagnosis, differentiate between harmless and aggressive disease and identify progression towards androgen independence at an early stage. In the P-Mark project, several recently developed, promising markers will be evaluated using clinically well-defined biorepositories. Following successful evaluation, these markers will be validated on a sample set derived from two large, European, prostate cancer studies and used for the identification of special risk groups in the general population. In addition, novel markers will be identified in the same biorepositories by different mass spectrometry techniques.


Assuntos
Proteínas Morfogenéticas Ósseas/sangue , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/mortalidade , Calicreínas Teciduais/sangue , Biomarcadores Tumorais/sangue , Proteína Morfogenética Óssea 6 , Humanos , Masculino , Espectrometria de Massas , Estadiamento de Neoplasias , Prognóstico , Antígeno Prostático Específico/classificação , Neoplasias da Próstata/sangue , Neoplasias da Próstata/urina , Medição de Risco , Sensibilidade e Especificidade , Análise de Sobrevida
14.
J Chromatogr A ; 1009(1-2): 155-69, 2003 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-13677656

RESUMO

Matrix metalloproteinases (MMPs) are zinc dependent metalloproteases characterized by the ability to cleave extracellular matrix and many other extracellular proteins. MMP activity is tightly regulated but disturbances in this regulation can contribute to various disease processes characterized by a progressive destruction of the extracellular matrix. The ability to profile classes of enzymes based on functionally related activities would greatly facilitate research about the involvement of MMPs in physiological and/or pathological states. Here we describe the characterization of an affinity sorbent using an immobilized reversible inhibitor as a stationary phase for the activity-based enrichment of MMPs from biological samples. With a ligand density of 9.8 mM and binding constant of 58 micromol/l towards MMP-12, the capturing power of the affinity sorbent was strong enough to extract MMP-12 spiked into serum with high selectivity from relatively large sample volumes. Experiments with endogenous inhibitors revealed that MMP-12 extraction is strictly activity-dependent, offering powerful means to monitor MMP activities in relation to physiological and/or pathological events by using affinity extraction as a first step in an MMP profiling method.


Assuntos
Marcadores de Afinidade , Metaloendopeptidases/isolamento & purificação , Inibidores de Proteases/metabolismo , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Humanos , Cinética , Metaloproteinase 12 da Matriz , Metaloendopeptidases/antagonistas & inibidores , Metaloendopeptidases/metabolismo , Ligação Proteica
15.
J Chromatogr A ; 1009(1-2): 171-8, 2003 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-13677657

RESUMO

LC-MS is a powerful method for the sensitive detection of proteins and peptides in biological fluids. However, the presence of highly abundant proteins often masks those of lower abundance and thus generally prevents their detection and identification in proteomic studies. In human serum the most abundant proteins are albumin and gamma-globulins. We tested several approaches to specifically reduce the level of these proteins based on either specific antibodies, dye ligands (for albumin) and protein A or G (for gamma-globulins). The resulting, depleted serum was analyzed by sodium dodecylsulfate-polyacrylamide gel electrophoresis and LC-MS for the residual presence of these abundant proteins as well as for other serum proteins that should remain after depletion. To test the applicability of this method to real-life samples, depleted serum of a cervical cancer patient was analyzed for the presence of a specific tumor marker protein SCCA1 (squamous cell carcinoma antigen 1; P29508), which is present at ng/ml concentrations. The results demonstrate that SCCA1 can be detected by LC-MS in patient serum following depletion of albumin and gamma-globulins thus opening the possibility of screening patient sera for other, so far unknown, tumor markers.


Assuntos
Albuminas/análise , Biomarcadores Tumorais/sangue , gama-Globulinas/análise , Sequência de Aminoácidos , Eletroforese em Gel de Poliacrilamida , Humanos , Dados de Sequência Molecular
16.
Bioelectrochemistry ; 58(1): 47-51, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12401570

RESUMO

The structures and formation energies of nucleic acid-phospholipid complexes both in the absence and in the presence of Mg(2+) ions were calculated taking double-stranded trinucleoside diphosphates NpNpN or heptanucleotides ApAp(NpNpN)pApA, composed of 64 possible combinations of genetic code, and phosphatidylcholine (PC) and sphingomyelin (SM) as model compounds. The dependence of intramolecular interactions on the primary structure of nucleic acid molecules and on the presence of a cationic bridge was revealed. The formation energies and structure of oligonucleotides were found by molecular mechanics calculations with the AMBER force field. The structures of phospholipid and MgCl(2) molecules were calculated by the semiempirical PM3 method, while the energies of phospholipid-oligonucleotide complexes were calculated by the molecular mechanics method. Calculations of complexes were carried out with consideration of solvation effects. Considerable gain in the formation energy of triple complexes is achieved due to the presence of the electroneutral metal bridge. A tendency toward increasing the stability of "triple" PC complexes (but not SM ones), containing guanosine- and cytidine-enriched triplets was revealed. Depending on the structure of NpNpN trinucleotides, the formation energy values of NpNpN-MgCl(2)-PC and ApAp(NpNpN)pApA-MgCl(2)-PC complexes differ by 1.7-2.6 kcal mol(-1), which can be considered as the atomic-scale manifestation of the recognition phenomenon. Presence of metal (II) ion bridge results in a greater stabilization of the phospholipid-nucleic acid complexes for SM in comparison to PC (the total energy difference equals to 4-16 kcal mol(-1)). Depending on the structure of NpNpN trinucleotides, the formation energies of NpNpN-MgCl(2)-SM and ApAp(NpNpN)pApA-MgCl(2)-SM complexes differ by 1.7-2.1 kcal.mol(-1), which is essential at physiological conditions and can also be considered as the recognition effect.


Assuntos
DNA/metabolismo , Magnésio/metabolismo , Fosfolipídeos/metabolismo , Sequência de Bases , Cátions Bivalentes , DNA/química , Metabolismo dos Lipídeos , Lipídeos/química , Magnésio/química , Modelos Moleculares , Conformação de Ácido Nucleico , Oligodesoxirribonucleotídeos/química , Fosfatidilcolinas/química , Fosfatidilcolinas/metabolismo , Esfingomielinas/química , Esfingomielinas/metabolismo , Termodinâmica
17.
Psychother Psychosom Med Psychol ; 51(1): 34-40, 2001 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-11227323

RESUMO

In spite of high prevalence rates, non-somatic health problems remain largely neglected in Third World First line health services. Deficits in staff qualification and motivation, clients' lack of readiness to perceive their problems as psychogenic, and "superstitious" beliefs as to their causation, material constraints, and the inapplicability of Western psychotherapeutic techniques in non-Western cultures are quoted as possible explanations. We assess their validity and potential consequences for the quality of service delivery; a different approach towards the training of staff, aiming at the integration of attention to psychological problems into everyday service provision, is discussed.


Assuntos
Negação em Psicologia , Pacientes/psicologia , Atenção Primária à Saúde/economia , Humanos , Qualidade da Assistência à Saúde , Autoimagem
18.
J Chromatogr B Biomed Sci Appl ; 752(2): 323-34, 2001 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-11270871

RESUMO

A methodology for the rapid and quantitative analysis of phosphorylation sites in proteins is presented. The coupling of capillary high-performance liquid chromatography (HPLC) to electrospray ionization mass spectrometry (ESI-MS) allowed one to distinguish phosphorylation sites based on retention time and mass difference from complex peptide mixtures. The methodology was first evaluated and validated for a mixture of non-, mono-, and dityrosine-phosphorylated synthetic peptides, corresponding to the tryptic fragment 485-496 (ALGADDSYYTAR) of the human protein tyrosine kinase ZAP-70. The limits of detection for the non-, mono- and diphosphorylated peptides were about 15, 40 and 100 fmol, respectively, when using a 300 microm I.D. column. Application of the method was extended to identify phosphopeptides generated from a trypsin digest of recombinant autophosphorylated ZAP-70, in particular with respect to quantifying the status at the regulatory phosphorylation sites Tyr-492 and Tyr-493. Combination of chromatographic and on-line tandem mass spectrometry data allowed one to ascertain the identity of the detected peptides, a prerequisite to analyses in more complex biological samples. As an extension to the methodology described above, we evaluated the feasibility of interfacing capillary HPLC to matrix assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF-MS), using a micromachined piezoelectric flow-through dispenser as the interface. This enabled direct arraying of chromatographically separated components onto a target plate that was precoated with matrix for subsequent analysis by MALDI-TOF-MS without further sample handling.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Proteínas Tirosina Quinases/metabolismo , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Sequência de Aminoácidos , Mapeamento de Peptídeos , Fosforilação , Proteínas Tirosina Quinases/química , Tripsina/metabolismo , Proteína-Tirosina Quinase ZAP-70
19.
Ann Biomed Eng ; 29(12): 1092-9, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11853261

RESUMO

Cells from human head-neck squamous cell carcinoma (hypopharynx, UMSCC11, and UMSCC22) and lung tumor (alveolus, UMSCC7) were investigated by light and scanning force microscopy (SFM) observation. In the present study a less-invasive contact mode was used to scan living cells in air covered with a thin fluid layer. The investigations were done without any pretreatment of the specimens for such observations as chemical fixation, or staining. Untreated tumor cells, and those treated with the antitumor drug hematoporphyrin IX derivative (HpD) were studied without photosensitizing. Additionally, the temperature influence on cell proliferation was studied. Three-dimensional topographic images and their magnifications offer highly informative insights into the untreated cell surface. In the present study, the cell structure destruction and cell death could partly be visualized by observing the head-neck tumor cells incubated with HpD. Most of the drug-treated head-neck tumor cells died (only 2%-5% of survivors). However, HpD could not affect cells of the lung tumor cell type. They, well known as more resistant against oxidation processes, survived to a great extent. Also, no distortion of the membrane under drug treatment could be observed. The possibilities and limits in the use of SFM for studying the topography of cell surfaces are presented in many details.


Assuntos
Antineoplásicos/farmacologia , Carcinoma de Células Escamosas/patologia , Éter de Diematoporfirina/farmacologia , Neoplasias de Cabeça e Pescoço/patologia , Neoplasias Pulmonares/patologia , Microscopia de Força Atômica/métodos , Artefatos , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/metabolismo , Divisão Celular/efeitos dos fármacos , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Fotorradiação com Hematoporfirina , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Temperatura , Células Tumorais Cultivadas
20.
J Chromatogr A ; 893(2): 293-305, 2000 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-11073299

RESUMO

Current developments in drug discovery in the pharmaceutical industry require highly efficient analytical systems for protein mapping providing high resolution, robustness, sensitivity, reproducibility and a high throughput of samples. The potential of two-dimensional (2D) HPLC as a complementary method to 2D-gel electrophoresis is investigated, especially in view of speed and repeatability. The method will be applied for proteins of a molecular mass <20 000 which are not well resolved in 2D-gel electrophoresis. The 2D-HPLC system described in this work consisted of anion- or cation-exchange chromatography in the first dimension and reversed-phase chromatography in the second dimension. We used a comprehensive two-dimensional approach based on different separation speeds. In the first dimension 2.5 microm polymeric beads bonded with diethylaminoethyl and sulfonic acid groups, respectively, were applied as ion exchangers and operated at a flow-rate of 1 ml/min. To achieve very high-speed and high-resolution separations in the second dimension, short columns of 14 x 4.6 mm I.D. with 1.5 microm n-octadecyl bonded, non-porous silica packings were chosen and operated at a flow-rate of 2.5 ml/min. Two reversed-phase columns were used in parallel in the second dimension. The analyte fractions from the ion-exchange column were transferred alternatively to one of the two reversed-phase columns using a 10-port switching valve. The analytes were deposited in an on-column focusing mode on top of one column while the analytes on the second column were eluted. Proteins, which were not completely resolved in the first dimension can, in most cases, be baseline-separated in the second dimension. The total value of peak capacity was calculated to 600. Fully unattended overnight runs for repeatability studies proved the applicability of the system. The values for the relative standard deviation (RSD) of the retention times of proteins were less than 1% (n = 15), while the RSDs of the peak areas were less than 15% (n = 15) on average. The limit of detection was 300 ng of protein on average and decreased to 50 ng for ovalbumin. The 2D-HPLC system offered high-resolution protein separations with a total analysis time of less than 20 min, equivalent to the run time of the first dimension.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cromatografia por Troca Iônica/métodos , Proteínas/química , Mapeamento de Peptídeos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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