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1.
J Helminthol ; 97: e38, 2023 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-37070359

RESUMO

In this paper we re-describe Trichuris muris based on morphological data following isolation from two commensal rodent species, Mus musculus from Mexico and Rattus rattus from Argentina. Furthermore, we provide a molecular characterization based on mitochondrial (cytochrome c oxidase subunit 1 mitochondrial gene) and nuclear (internal transcribed spacer 2 region) markers in order to support the taxonomic identification of the studied specimens of T. muris from M. musculus. We distinguished T. muris from 29 species of Trichuris found in American rodents based on morphological and biometrical features, such as the presence of a spicular tube, length of spicule, size of proximal and distal cloacal tube and non-protrusive vulva. We suggest that spicular tube patterns can be used to classify Trichuris species in three groups. Considering that the diagnosis among the species of this genus is mainly based on morphometry, this proposal represents a relevant contribution. We provide molecular studies on two markers, making this the first contribution for T. muris in the Americas. This study makes an important contribution to the integrative taxonomy of cosmopolitan nematode species, and its correct determination from the parasitological study of commensal rodents.


Assuntos
Roedores , Trichuris , Camundongos , Feminino , Animais , Filogenia , Argentina , Genes Mitocondriais
2.
Photochem Photobiol Sci ; 14(10): 1844-52, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26205482

RESUMO

The reconstitution of the integral membrane protein photosynthetic reaction center (RC) in polymersomes, i.e. artificial closed vesicles, was achieved by the micelle-to-vesicle transition technique, a very mild protocol based on size exclusion chromatography often used to drive the incorporation of proteins contemporarily to liposome formation. An optimized protocol was used to successfully reconstitute the protein in a fully active state in polymersomes formed by the tri-block copolymers PMOXA22-PDMS61-PMOXA22. The RC is very sensitive to its solubilizing environment and was used to probe the positioning of the protein in the vesicles. According to charge-recombination experiments and to the enzymatic activity assay, the RC is found to accommodate in the PMOXA22 region of the polymersome, facing the water bulk solution, rather than in the PDMS61 transmembrane-like region. Furthermore, polymersomes were found to preserve protein integrity efficiently as the biomimetic lipid bilayers but show a much longer temporal stability than lipid based vesicles.


Assuntos
Membranas Artificiais , Complexo de Proteínas do Centro de Reação Fotossintética/metabolismo , Polímeros/química , Interações Hidrofóbicas e Hidrofílicas , Cinética , Transporte Proteico , Rhodobacter sphaeroides/enzimologia
3.
Musculoskelet Surg ; 108(2): 201-214, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38485902

RESUMO

PURPOSE: The main purpose of the present study was to evaluate if there is a difference between objective or subjective administration of the MSTS score in a cohort of patients affected by musculoskeletal oncological diseases. MATERIALS AND METHODS: All patients who underwent surgery for bone or soft tissue localization of neoplastic disease in lower or upper limb from June 2015 to June 2020 were considered eligible. In order to administer the score as a PROM, the MSTS was first translated and cross-culturally adapted in Italian. During follow up visits, all patients filled out Italian versions of SF36, TESS and MSTS. Psychometric properties of the Italian version of MSTS were analyzed. Correlation between objective and self-administered MSTS score was assessed through Pearson's coefficient. RESULTS: A finale sample of 110 patients were included: 59 affected by lower extremity involvement and 51 affected by upper extremity involvement. The Italian version of the MSTS score showed good psychometric properties for both lower and upper extremity. The correlation between self-administered and hetero-administered version of the questionnaire was as high as r = 0.97 for lower extremities and r = 0.96 for upper extremities. CONCLUSIONS: The Italian version of the MSTS is a valid tool to evaluate outcomes of surgical treatment of patients affected by extremities tumors and it can be used as a subjective tool for both lower and upper extremity.


Assuntos
Neoplasias Ósseas , Extremidade Inferior , Psicometria , Extremidade Superior , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Extremidade Superior/cirurgia , Itália , Neoplasias Ósseas/cirurgia , Idoso , Adulto , Extremidade Inferior/cirurgia , Inquéritos e Questionários , Neoplasias de Tecidos Moles/cirurgia , Resultado do Tratamento , Reprodutibilidade dos Testes
4.
Int J Comput Assist Radiol Surg ; 18(12): 2167-2177, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36881354

RESUMO

PURPOSE: During reconstructive surgery, knee and hip replacements, and orthognathic surgery, small misalignments in the pose of prosthesis and bones can lead to severe complications. Hence, the translational and angular accuracies are critical. However, traditional image-based surgical navigation lacks orientation data between structures, and imageless systems are unsuitable for cases of deformed anatomy. We introduce an open-source navigation system using a multiple registration approach that can track instruments, implants, and bones to precisely guide the surgeon in emulating a preoperative plan. METHODS: We derived the analytical error of our method and designed a set of phantom experiments to measure its precision and accuracy. Additionally, we trained two classification models to predict the system reliability from fiducial points and surface matching registration data. Finally, to demonstrate the procedure feasibility, we conducted a complete workflow for a real clinical case of a patient with fibrous dysplasia and anatomical misalignment of the right femur using plastic bones. RESULTS: The system is able to track the dissociated fragments of the clinical case and average alignment errors in the anatomical phantoms of [Formula: see text]  mm and [Formula: see text]. While the fiducial-points registration showed satisfactory results given enough points and covered volume, we acknowledge that the surface refinement step is mandatory when attempting surface matching registrations. CONCLUSION: We believe that our device could bring significant advantages for the personalized treatment of complex surgical cases and that its multi-registration attribute is convenient for intraoperative registration loosening cases.


Assuntos
Cirurgia Assistida por Computador , Tomografia Computadorizada por Raios X , Humanos , Tomografia Computadorizada por Raios X/métodos , Reprodutibilidade dos Testes , Cirurgia Assistida por Computador/métodos , Imagens de Fantasmas
5.
Front Cell Dev Biol ; 10: 835793, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35445027

RESUMO

Recipients of myeloablative cord blood transplants (CBT) are known to experience delayed hematopoietic recovery and an increased risk of transplant related mortality (TRM). We developed methods for ex vivo expansion and cryopreservation of CB stem and progenitor cells. 15 patients with hematologic malignancies were enrolled in this single center phase II trial between September 2010 and August 2012 to assess the safety of infusing a non-HLA-matched expanded CB product to bolster a conventional CBT. On the day of transplant, an infusion of the expanded CB product followed the primary graft (1 or 2 unmanipulated CB units). All patients engrafted. Median time to neutrophil and platelet recovery was 19 and 35 days, respectively. Early myelomonocytic recovery was almost entirely due to cells arising from the non-HLA-matched expansion product and were no longer detected at day 14 in all but 2 patients. The probability of 3-years disease free survival was 86%. No TRM was observed throughout the study period, and only 2 patients relapsed. All patients presented with grade II acute graft-versus-host disease (aGVHD) at a median time of 32 days, with no grade III-IV aGVHD observed. At 2 years only 2 patients remain on immunosuppressive therapy for mild chronic GVHD. This phase II safety study demonstrate that infusion of an off-the-shelf non-HLA-matched expanded CB product in addition to a conventional CB graft was safe and led to sustained myeloid recovery. Based on these encouraging results, a prospective multicenter randomized trial utilizing this product has been conducted and results will be soon released. ClinicalTrials.gov Identifier: NCT01175785.

6.
Clin Ter ; 172(3): 186-189, 2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-33956033

RESUMO

ABSTRACT: In the large series of forensic injury, death from accidental me-chanical asphyxiation in adults is rare and is usually secondary to suffocation, aspiration, strangulation caused by entrapment of clothing in machinery (deaths at work) or asphyxiation in the course of erotic maneuvers. Compression asphyxia is a form of violent mechanical asphyxia in which the asphyxiated insult is produced by means of a compression and constriction mechanism of the thoracic cage. The authors report an unusual case of asphyxiated death from chest com-pression resulting from the action of a compacting machine, which occurred in a person who had fallen asleep in a waste bin.


Assuntos
Acidentes , Asfixia/etiologia , Adulto , Medicina Legal , Humanos , Masculino
7.
Front Oncol ; 10: 583349, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33163411

RESUMO

INTRODUCTION: Cord blood transplantation (CBT) recipients are at increased risk of mortality due to delayed immune recovery (IR). Prior studies in CBT patients have shown that recovery of absolute lymphocyte count is predictive of survival after transplant. However, there are no data on the association of T-cell receptor (TCR) and clinical outcomes after CBT. Here we retrospectively performed TCR beta chain sequencing on peripheral blood (PB) samples of 34 CBT patients. METHODS: All patients received a total body irradiation based conditioning regimen and cyclosporine and MMF were used for graft versus host disease (GvHD) prophylaxis. PB was collected pretransplant on days 28, 56, 80, 180, and 1-year posttransplant for retrospective analysis of IR utilizing high-throughput sequencing of TCRß rearrangements from genomic DNA extracted from PB mononuclear cells. To test the association between TCR repertoire diversity and patient outcomes, we conducted a permutation test on median TCR repertoire diversity for patients who died within the first year posttransplant versus those who survived. RESULTS: Median age was 27 (range 1-58 years) and most of the patients (n = 27) had acute leukemias. There were 15 deaths occurring between 34 to 335 days after transplant. Seven deaths were due to relapse. Rapid turnover of T cell clones was observed at each time point, with TCR repertoires stabilizing by 1-year posttransplant. TCR diversity values at day 100 for patients who died between 100 and 365 days posttransplant were significantly lower than those of the surviving patients (p = 0.01). CONCLUSIONS: Using a fast high-throughput TCR sequencing assay we have demonstrated that high TCR diversity is associated with better patient outcomes following CBT. Importantly, this assay is easily performed on posttransplant PB samples, even as early as day 28 posttransplant, making it an excellent candidate for early identification of patients at high risk of death.

8.
Med Biol Eng Comput ; 58(7): 1499-1514, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32385790

RESUMO

Currently, simulations of the induced currents in the brain produced by transcranial magnetic stimulation (TMS) are used to elucidate the regions reached by stimuli. However, models commonly found in the literature are too general and neglect imperfections in the windings. Aiming to predict the stimulation sites in patients requires precise modeling of the electric field (E-field), and a proper calibration to adequate to the empirical data of the particular coil employed. Furthermore, most fabricators do not provide precise information about the coil geometries, and even using X-ray images may lead to subjective interpretations. We measured the three components of the vector magnetic field induced by a TMS figure-8 coil with spatial resolutions of up to 1 mm. Starting from a computerized tomography-based coil model, we applied a multivariate optimization algorithm to automatically modify the original model and obtain one that optimally fits the measurements. Differences between models were assessed in a human brain mesh using the finite-elements method showing up to 6% variations in the E-field magnitude. Our calibrated model could increase the precision of the estimated E-field induced in the brain during TMS, enhance the accuracy of delivered stimulation during functional brain mapping, and improve dosimetry for repetitive TMS. Graphical Abstract Geometrical model of TMS coil based on TAC images is optimally deformed to match magnetic field measurements. The calibrated model's induced electric field in the brain differs from the original.


Assuntos
Terapia Assistida por Computador/métodos , Estimulação Magnética Transcraniana/métodos , Algoritmos , Encéfalo/diagnóstico por imagem , Calibragem , Humanos , Modelos Biológicos , Estimulação Magnética Transcraniana/instrumentação
9.
Scand J Immunol ; 68(6): 616-23, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19055699

RESUMO

Immunotherapy for solid cancers, such as oesophageal adenocarcinoma (OAC), is generally hampered by an unfavourable immunological tumour microenvironment. This prompted us to investigate the nature of the OAC environment. Biopsies of tumour and normal control tissues were collected from 17 OAC patients, and investigated using fluorescent immunohistochemistry (IHC) for the expression of cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF), transforming growth factor-beta, indoleamine 2-3 dioxygenase, CXCL3 and CXCR1, and for measuring a panel of cytokines by cytometric bead array (CBA), and for Granzyme B (GrB), Perforin and PI9 detection by semi-quantitative PCR (QPCR). IHC showed that expression of all the above-mentioned factors is upregulated in 80-93% of the tumours. By QPCR, the cytokine interleukin (IL)-8 was significantly upregulated in tumour samples (P < 0.05). IL-6, IL-10, GrB and Perforin did not show any significant difference between normal and tumour samples, whereas PI9 levels were significantly higher in normal when compared with the tumour samples. CBA confirmed upregulation of IL-8 and show upregulation of IL-1beta in the tumours (P < 0.05). Regarding IL-6 and interferon (IFN)-gamma, no significant differences were observed between normal and tumour tissues. The OAC microenvironment is characterized by a lack of cytokines and factors that normally would enhance anti-cancer responses, such as IFN-gamma and GrB, and by a high expression of several immuno-suppressive factors, such as COX-2, VEGF and IL-8. For future improvement of treatment efficacy of OAC patients, it will be of importance to combine immunotherapy with immune-modulating agents.


Assuntos
Adenocarcinoma/imunologia , Ciclo-Oxigenase 2/metabolismo , Citocinas/metabolismo , Neoplasias Esofágicas/imunologia , Evasão Tumoral , Fator A de Crescimento do Endotélio Vascular/metabolismo , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Idoso , Idoso de 80 Anos ou mais , Ciclo-Oxigenase 2/genética , Citocinas/genética , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/metabolismo , Feminino , Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , RNA/genética , Fator A de Crescimento do Endotélio Vascular/genética
10.
Dis Esophagus ; 21(7): 628-33, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18430189

RESUMO

Barrett's esophagus (BE) is a metaplastic process in which the normal squamous epithelium of the distal esophagus is replaced by columnar lined epithelium. The aim was to gain more insight in the process of metaplasia and to identify which genes are specifically expressed by the epithelial cells and the surrounding tissues in BE. Hereto, the gene expression profile of a BE epithelial primary cell culture was compared to that of a BE biopsy. To specifically obtain the epithelial cell layer, epithelial cells from biopsies of BE were cultured using a Barrett specific culturing medium. Serial analysis of gene expression was applied to obtain a transcription library of the primary epithelial cell culture. The transcriptome was analyzed and compared to a previously described transcriptome of a BE biopsy. Validation of results by reverse transcriptase-polymerase chain reaction was performed using tissues of 16 BE patients and 16 primary cell cultures. Over 43,000 tags were sequenced. Genes specifically expressed by the Barrett epithelial cells were for instance Lipocalin 2 and Cyclin D1, whereas annexin A10, trefoil factor (TFF)1 and TFF2 were specifically expressed in the BE biopsies. The comparison of the gene expression profiles of BE primary cultured epithelial cells with BE biopsy defines a subset of genes that are specifically expressed by the epithelial cells and another subset that most likely is expressed by the underlying stromal tissues in the BE biopsy specimens.


Assuntos
Esôfago de Barrett/genética , Esôfago de Barrett/patologia , Proteínas de Neoplasias/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Células Epiteliais/fisiologia , Feminino , Perfilação da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/metabolismo , RNA Mensageiro/metabolismo , Células Estromais/fisiologia , Fator Trefoil-2 , Células Tumorais Cultivadas
11.
Bone Marrow Transplant ; 52(6): 799-802, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27991893

RESUMO

The utilization of cord blood as a source of stem cells for transplantation has decreased in recent years. Although cord blood transplantation (CBT) is an established practice for the treatment of adult and pediatric patients with hematological malignancies, the high acquisition cost of CB units along with high transplant-related mortality due to delayed hematopoietic recovery and immune reconstitution have contributed to the slowing in widespread adoption of CBT. Strategies aimed to enhance speed of engraftment and ongoing clinical trials are investigating ways to make CBT more widely available. Meanwhile, the recent clinical data suggest that the choice of CBT might be preferable for patients with pre-transplant minimal residual disease. We review here the background data on the utilization of CB for the treatment of hematological malignancies, and discuss the current challenges and future directions in the field of CBT.


Assuntos
Transplante de Células-Tronco de Sangue do Cordão Umbilical , Neoplasias Hematológicas/terapia , Adolescente , Adulto , Aloenxertos , Criança , Pré-Escolar , Feminino , Neoplasias Hematológicas/sangue , Humanos , Lactente , Masculino , Neoplasia Residual
12.
Stud Health Technol Inform ; 245: 1375, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29295454

RESUMO

This poster aims to achieve an "in vitro" comparative study between three methods: 2D digital images planning and execution without navigation (freehand with ruler and caliper), 3D planning and execution without navigation (freehand with ruler and caliper) and 3D planning and execution guided with navigation. 3D planning and navigated procedures potentially improve sarcoma resection.


Assuntos
Neoplasias Ósseas/cirurgia , Sarcoma/cirurgia , Cirurgia Assistida por Computador , Humanos , Imageamento Tridimensional
13.
Haematologica ; 91(8 Suppl): ECR33, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16923517

RESUMO

The p.M172K TFR2 mutation was identified in two Italian siblings aged 32 and 40 years old with primary iron overload. The two patients showed a severe increase in serum iron indices. From the age of 25, the male sib also revealed abnormal levels of hepatic enzymes, presumably in relation to iron induced liver damage. Clinical findings seem to evidence that type 3 hemochromatosis can be more serious than classic hemochromatosis. This report adds two more type 3 hereditary hemochromatosis cases which suggest that TFR2 mutations could be more frequently involved in non-HFE hemochromatosis than has been actually thought.


Assuntos
Predisposição Genética para Doença , Hemocromatose/genética , Sobrecarga de Ferro/metabolismo , Receptores da Transferrina/genética , Adulto , Análise Mutacional de DNA , Família , Feminino , Hemocromatose/metabolismo , Humanos , Itália , Masculino , Transferrina/metabolismo
14.
Front Big Data ; 4: 815686, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34927065
15.
Eur J Histochem ; 60(1): 2573, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26972714

RESUMO

There is recent mounting evidence that nanoparticles may have enhanced toxicological potential in comparison to the same material in the bulk form. The aim of this study was to develop a new method for unmask asbestos nanofibers from Formalin-Fixed, Paraffin-Embedded tissue. There is an increasing amount of evidence that nanoparticles may enhance toxicological potential in comparison to the same material in the bulk form. The aim of this study was to develop a new method to unmask asbestos nanofibers from Formalin-Fixed Paraffin-Embedded (FFPE) tissue. For the first time, in this study we applied Energy Dispersive X-ray (EDX) microanalysis through transmission electron microscopy to demonstrate the presence of asbestos nanofibers in histological specimens of patients with possible occupational exposure to asbestos. The diagnostic protocol was applied to 10 randomly selected lung cancer patients with no history of previous asbestos exposure. We detected asbestos nanofibers in close contact with lung cancer cells in two lung cancer patients with previous possible occupational exposure to asbestos. We were also able to identify the specific asbestos iso-type, which in one of the cases was the same rare variety used in the workplace of the affected patient. By contrast, asbestos nanofibers were not detected in lung cancer patients with no history of occupational asbestos exposure. The proposed technique can represent a potential useful tool for linking the disease to previous workplace exposure in uncertain cases. Furthermore, Formalin-Fixed Paraffin-Embedded (FFPE) tissues stored in the pathology departments might be re-evaluated for possible etiological attribution to asbestos in the case of plausible exposure. Since diseases acquired through occupational exposure to asbestos are generally covered by workers' insurance in most countries, the application of the protocol used in this study may have also relevant social and economic implications.


Assuntos
Amianto , Neoplasias Pulmonares , Nanofibras/química , Exposição Ocupacional/efeitos adversos , Amianto/química , Amianto/toxicidade , Feminino , Humanos , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino
16.
Bone Marrow Transplant ; 51(12): 1588-1593, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27400068

RESUMO

Adult umbilical cord blood transplantation (CBT) has emerged as an important option for patients lacking matched related (MRD) and matched unrelated donors (MUD). We compared chronic GVHD (cGVHD) incidence, immunosuppression burden and late infections and hospitalizations in consecutive patients undergoing CBT (n=51) versus peripheral blood MUD transplant (n=57) at our center between June 2009 and April 2014. At 3 years post transplantation, the cumulative incidence (CI) of moderate to severe cGVHD was 44% following MUD versus 8% following CBT (P=0.0006) and CI of any cGVHD was 68% following MUD versus 32% following CBT (P=0.0017). Median time to being off immunosuppression among CB patients was 268 days versus not reached among MUD patients (P<0.0001). Late infections and late hospitalized days were reduced in CB patients (P=0.1 and <0.001, respectively). Three-year CI of transplant-related mortality (TRM) and relapse as well as 3-year overall survival (OS) were similar following CB and MUD transplantation. We demonstrate a significantly lower incidence of cGVHD, immunosuppression burden and late complication rate following UCB versus peripheral blood MUD transplant without decreased OS, increased relapse or early TRM. Combined with the rapid availability of UCB, these findings have led our center to move primarily to UCB over peripheral blood MUD when a MRD is not available.


Assuntos
Transplante de Células-Tronco de Sangue do Cordão Umbilical/métodos , Doença Enxerto-Hospedeiro/etiologia , Transplante de Células-Tronco Hematopoéticas/métodos , Adolescente , Adulto , Idoso , Doença Crônica , Transplante de Células-Tronco de Sangue do Cordão Umbilical/efeitos adversos , Transplante de Células-Tronco de Sangue do Cordão Umbilical/mortalidade , Transplante de Células-Tronco de Sangue do Cordão Umbilical/normas , Feminino , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Transplante de Células-Tronco Hematopoéticas/mortalidade , Transplante de Células-Tronco Hematopoéticas/normas , Teste de Histocompatibilidade , Humanos , Terapia de Imunossupressão , Incidência , Infecções , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Doadores não Relacionados , Adulto Jovem
17.
Med Eng Phys ; 27(7): 591-8, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16076559

RESUMO

Medical physics education and training requires the use of extensive imaging material and specific explanations. These requirements provide an excellent background for application of e-Learning. The EU projects Consortia EMERALD and EMIT developed five volumes of such materials, now used in 65 countries. EMERALD developed e-Learning materials in three areas of medical physics (X-ray diagnostic radiology, nuclear medicine and radiotherapy). EMIT developed e-Learning materials in two further areas: ultrasound and magnetic resonance imaging. This paper describes the development of these e-Learning materials (consisting of e-books and educational image databases). The e-books include tasks helping studying of various equipment and methods. The text of these PDF e-books is hyperlinked with respective images. The e-books are used through the readers' own Internet browser. Each Image Database (IDB) includes a browser, which displays hundreds of images of equipment, block diagrams and graphs, image quality examples, artefacts, etc. Both the e-books and IDB are engraved on five separate CD-ROMs. Demo of these materials can be taken from www.emerald2.net.


Assuntos
Engenharia Biomédica/educação , Instrução por Computador/métodos , Currículo , Bases de Dados Factuais , Diagnóstico por Imagem , Educação a Distância/métodos , Educação Profissionalizante/métodos , Internet , União Europeia , Física Médica/educação , Multimídia
18.
Free Radic Biol Med ; 20(4): 601-6, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8904302

RESUMO

This study was performed to test the hypothesis that conferring multiple drug resistance reduces cell susceptibility to irradiation and iron-stimulated lipid peroxidation. Multidrug resistant (PN1A) and parental drug sensitive (PSI-2) cell lines were exposed to ADP-Fe or Ascorbate-Fe complexes at 37 degrees C and to irradiation. Lipid peroxidation was estimated by the TBA test, whereas x-ray effect was estimated by clonogenic assay. Cell glutathione-S-transferase (GST), total and Se-dependent glutathione peroxidase (GSH-Px) activities, and glutathione and vitamin E were measured. PN1A produced more peroxides than PSI-2 after exposure to iron complexes and formed fewer colonies after irradiation. Higher activities of GST and total and Se-GSH-Px were observed in PN1A. Vitamin E and total glutathione did not differ in the two cell subclones. These data show that the induction of the mdr1 phenotype by transfection of mdr1 gene in 3T3 cells increases susceptibility to irradiation and iron stimulated lipid peroxidation.


Assuntos
Resistência a Múltiplos Medicamentos/genética , Peroxidação de Lipídeos/fisiologia , Tolerância a Radiação/genética , Transfecção , Células 3T3 , Animais , Radicais Livres , Camundongos , Fenótipo
19.
Bioelectrochemistry ; 63(1-2): 125-8, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15110262

RESUMO

Isolated and purified reaction centers (RC) from Rhodobacter sphaeroides R-26.1 were solubilised in detergent with excess quinone and external electron donors and illuminated in the presence of pyranine. The pH change accompanying the reaction center photocycle was monitored by recording the variation of the pyranine fluorescence intensity. Using Q(B)-depleted reaction centers or blocking the photocycle with terbutryne strongly reduced the pH change. The usefulness and limits of this technique in monitoring the pH changes during the RC photocycle are also discussed.


Assuntos
Sulfonatos de Arila , Fotoquímica/métodos , Complexo de Proteínas do Centro de Reação Fotossintética/química , Complexo de Proteínas do Centro de Reação Fotossintética/efeitos da radiação , Rhodobacter sphaeroides/metabolismo , Espectrometria de Fluorescência/métodos , Relação Dose-Resposta à Radiação , Corantes Fluorescentes , Concentração de Íons de Hidrogênio , Cinética , Luz , Complexo de Proteínas do Centro de Reação Fotossintética/análise , Prótons , Radiometria/métodos
20.
Tumori ; 85(6): 503-7, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10774574

RESUMO

AIMS AND BACKGROUND: Several anticancer drugs increase cell sensitivity to irradiation. Gemcitabine (2', 2' difluorodeoxycytidine) decreases the cellular dNTP pools and thus significantly increases the sensitivity to the DNA damaging effects of low-dose radiation. In this study we have investigated whether gemcitabine may play a role as radiosensitizer also in lung adenocarcinoma treatment. METHODS & STUDY DESIGN: We studied this nucleoside analogue in normal and transformed human cell lines (fetal lung and lung adenocarcinoma). After drug treatment, cell lines were irradiated with different doses. Cell damage following drug treatment and/or irradiation was assessed by measuring intracellular ATP level and by the colony forming assay. RESULTS: The two cell lines significantly differed in their sensitivity to the toxic effects of the drug; the normal cell line was much more resistant than its transformed counterpart. This difference was observed in both assays, although it was more evident in the colony forming assay. A low radiation dose (50-100 cGy) did not cause any significant damage to transformed cells; normal cells were more resistant and doses up to 500 cGy caused little damage. However, when transformed cells were pretreated for three hours with gemcitabine, even a nontoxic concentration of the drug (1-10 nM) caused a marked sensitization of the cells to irradiation (50-100 cGy). The radiosensitizing effect of gemcitabine could be observed also in normal cells, although these cells were more resistant to the damaging effects of both anticancer treatments. CONCLUSIONS: This study demonstrates that gemcitabine, a chemotherapeutic agent already used in the clinic, could be proposed as a radiosensitizer for radiation therapy of lung adenocarcinoma, having a clearly potentiating effect on lowdose radiation.


Assuntos
Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/radioterapia , Antimetabólitos Antineoplásicos/farmacologia , Desoxicitidina/análogos & derivados , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/radioterapia , Pulmão/efeitos dos fármacos , Pulmão/efeitos da radiação , Radiossensibilizantes/farmacologia , Linhagem Celular , Desoxicitidina/farmacologia , Relação Dose-Resposta à Radiação , Humanos , Pulmão/citologia , Dosagem Radioterapêutica , Eficiência Biológica Relativa , Células Tumorais Cultivadas , Gencitabina
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