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1.
Cell Tissue Bank ; 24(1): 265-272, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36042071

RESUMO

The demand for skin tissue allografts to treat burns and other types of injuries increases each year to the extent that categories of donors formerly deemed "unsuitable", such as victims of suicide by polytrauma or poisoning, are now considered. Patients who died by ingestion of/exposure to toxic substances can be accepted as tissue donors after assessment of graft safety to rule out any risks of transferring toxic substances to the recipient. A cadaveric skin donation was obtained from a 57-year-old woman who died from intoxication after ingesting colchicine tablets (0.2 mg/kg). To determine the safety of cadaveric skin allografts, high-performance liquid chromatography-mass spectrometry (LC-MS/MS) was used to identify and quantify colchicine in procured skin. Results revealed that colchicine concentrations were lower than the instrument limit of detection (LOD) of 0.5 ng/mg both in epidermis and dermis. Cell viability assessed through the MTT ([3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]) test was within standard limits. Thanks to accurate tests performed, which are routinely applied also in clinical diagnostics and forensic toxicology, it was possible to ascertain the safety and suitability of skin tissue for donation.


Assuntos
Suicídio , Espectrometria de Massas em Tandem , Feminino , Humanos , Pessoa de Meia-Idade , Cromatografia Líquida , Colchicina , Morte , Cadáver
2.
Int J Endocrinol ; 2018: 4298195, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30675159

RESUMO

Bisphenol A is an industrial chemical compound, pervasively polluting the environment and diet, classified as an endocrine disruptor because of its interference effects on the endocrine system. In zebrafish, BPA exposure induces follicular atresia. To acquire knowledge on this atretic effect, using a qualitative and quantitative histomorphological approach, we studied zebrafish ovarian follicular stage development in response to low BPA concentrations. Results show that BPA interferes with follicular progression by affecting the previtellogenic and vitellogenic phases. In particular, BPA exposure (i) increases follicular recruitment by acting on primary stage follicles, (ii) forces the follicular transition from stage III to stage IV producing enlarged stage IV follicles, and (iii) induces atresia by producing atretic follicles that are peculiarly enlarged (i.e., big atretic follicles). We suggest that BPA induces atresia by the primary effect on recruitment of stage I follicles. This forces follicular progression and produces stage IV follicles that are peculiarly enlarged that undertake the atretic development.

3.
Acta Anaesthesiol Scand ; 60(7): 934-44, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27109305

RESUMO

INTRODUCTION: Cerebrovascular complications rate in patients treated with extracorporeal membrane oxygenation (ECMO) is about 7%. Ischemic stroke may be caused by solid or gaseous microemboli due to thrombosis within the circuit or cannula. Transcranial Doppler (TCD) is the only method able to detect microembolic signals (MES) in real time. The objective of this study was to detect possible MES by TCD in patients treated with veno-venous (VV) and veno-arterial (VA) ECMO and to test for a relation between the number of MES and the 6-month clinical outcome of these patients. METHODS: This is a monocentric observational prospective study in patients consecutively admitted and treated with ECMO at our regional ECMO referral center in 18 months. TCD detection of MES was performed in patients upon initiation of treatment and then repeated during treatment. RESULTS: Two hundred and forty-eight TCD monitoring were performed in 42 VV and 11 VA ECMO patients. MES were detected in 26.2% of VV ECMO patients and in 81.8% of VA ECMO patients (P < 0.001). In both subgroups of patients, no correlation was found between MES detection and extracorporeal flow velocities or aPTT values. In VA ECMO patients, an inverse correlation between left ventricular ejection fraction and MES grading was found (P = 0.037). In both groups, no clinical neurological impairments correlated to MES detection were found at 6 months follow-up. CONCLUSIONS: MES were found in both ECMO configurations; independently from their pathophysiology, MES do not seem to influence clinical outcome. Multicenter studies are still required with more extensive cases to confirm these results.


Assuntos
Oxigenação por Membrana Extracorpórea/efeitos adversos , Embolia Intracraniana/diagnóstico por imagem , Ultrassonografia Doppler Transcraniana/métodos , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
5.
Am J Transplant ; 14(3): 635-46, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24456049

RESUMO

REFINE was a 12-month, prospective, open-label study in 356 patients receiving de novo liver transplantation for hepatitis C virus (HCV) cirrhosis, randomized to cyclosporine A (CsA) or tacrolimus with (i) no steroids, IL-2 receptor antibody induction and mycophenolic acid, or (ii) slow steroid tapering. The primary analysis population based on availability of liver biopsies comprised 165 patients (88 CsA, 77 tacrolimus). There was no difference in the primary endpoint, fibrosis stage ≥2 at 12 months, which occurred in 63/88 CsA-treated patients (71.6%) and 52/77 tacrolimus-treated patients (67.5%) (odds ratio [OR] 1.11; 95% CI 0.56, 2.21; p = 0.759). Similarly, no significant between-group difference occurred at month 24 (OR 1.15; 95% CI 0.47, 2.80; p = 0.767). Among steroid-free patients, fibrosis score ≥2 was significantly less frequent with CsA versus tacrolimus at month 12 (7/37 [18.9%] vs. 16/38 [42.1%]; p = 0.029). HCV viral load was similar in both the tacrolimus- and CsA-treated cohorts. Mean blood glucose was significantly higher with tacrolimus from day 15 onward. Biopsy-proven acute rejection, graft loss and death were similar. These results showed no differences in posttransplant HCV-induced liver fibrosis between patients treated with CsA or tacrolimus in steroid-containing regimens, whereas CsA in steroid-free protocols was associated with reduced severity of fibrosis progression at 1 year posttransplant.


Assuntos
Ciclosporina/uso terapêutico , Rejeição de Enxerto/tratamento farmacológico , Hepatite C/cirurgia , Imunossupressores/uso terapêutico , Cirrose Hepática/prevenção & controle , Transplante de Fígado , Tacrolimo/uso terapêutico , Feminino , Seguimentos , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto/efeitos dos fármacos , Hepacivirus/patogenicidade , Hepatite C/complicações , Hepatite C/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Taxa de Sobrevida
6.
Minerva Anestesiol ; 80(11): 1217-27, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24430005

RESUMO

Donor scarcity and the increased need for organ transplantation has prompted the development of an alternative source of donors to the more conventional brain dead donor. While in a Beating-Heart donor, abdominal and intrathoracic organs are perfused, in a non-beating heart donor (NHBD, or DCD), perfusion should be maintained, after confirmation of death, by means of ECMO and inflation of intra-aortic balloon accordingly to the localization of the organs that should be transplanted. In this setting, ECMO allows selective perfusion of the organs which should be transplanted ("compartmental ECMO"). The present review is aimed at summarizing the rationale for ECMO use in organ donation in DCD and the available evidence on this topic, as well as available evidence (in clinical studies) on normothermic organ preservation using ECMO in adults. Despite the fact that available studies suffer from methodological limitations (small cohorts, retrospective analysis, not always comparative), they all reach the same conclusion: the concept of extracorporeal support with oxygenation in DCD seems very promising since it has been reported to increase the available organ supply by approximately 20% to 25%2 by increasing the number of donors by approximately 33%. Centres with ECMO facilities should implement local programmes for donation after cardiac death (both in the emergency department and intensive care) using ECMO taking into account that this technique has been proven to increase donor pool.


Assuntos
Oxigenação por Membrana Extracorpórea/métodos , Choque , Obtenção de Tecidos e Órgãos/métodos , Morte , Humanos , Preservação de Órgãos
8.
Mol Ecol ; 19(3): 557-68, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20051010

RESUMO

The Mediterranean Sea is a two-basin system, with the boundary zone restricted to the Strait of Sicily and the narrow Strait of Messina. Two main population groups are recognized in the Mediterranean endemic seagrass Posidonia oceanica, corresponding to the Western and the Eastern basins. To address the nature of the East-West cleavage in P. oceanica, the main aims of this study were: (i) to define the genetic structure within the potential contact zone (i.e. the Strait of Sicily) and clarify the extent of gene flow between the two population groups, and (ii) to investigate the role of present water circulation patterns vs. past evolutionary events on the observed genetic pattern. To achieve these goals, we utilized SSR markers and we simulated, with respect to current regime, the possible present-day dispersal pattern of Posidonia floating fruits using 28-day numerical Lagrangian trajectories. The results obtained confirm the presence of the two main population groups, without any indices of reproductive isolation, with the break zone located at the level of the Southern tip of Calabria. The populations in the Strait of Sicily showed higher affinity with Western than with Eastern populations. This pattern of genetic structure probably reflects historical avenues of recolonization from relict glacial areas and past vicariance events, but seems to persist as a result of the low connectivity among populations via marine currents, as suggested by our dispersal simulation analysis.


Assuntos
Alismatales/genética , Fluxo Gênico , Genética Populacional , Simulação por Computador , DNA de Plantas/genética , Evolução Molecular , Genótipo , Geografia , Mar Mediterrâneo , Repetições de Microssatélites , Polimorfismo Genético , Análise de Componente Principal , Análise de Sequência de DNA , Movimentos da Água
9.
Database (Oxford) ; 2009: bap009, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20157482

RESUMO

As ecosystem engineers, seagrasses are angiosperms of paramount ecological importance in shallow shoreline habitats around the globe. Furthermore, the ancestors of independent seagrass lineages have secondarily returned into the sea in separate, independent evolutionary events. Thus, understanding the molecular adaptation of this clade not only makes significant contributions to the field of ecology, but also to principles of parallel evolution as well. With the use of Dr. Zompo, the first interactive seagrass sequence database presented here, new insights into the molecular adaptation of marine environments can be inferred. The database is based on a total of 14 597 ESTs obtained from two seagrass species, Zostera marina and Posidonia oceanica, which have been processed, assembled and comprehensively annotated. Dr. Zompo provides experimentalists with a broad foundation to build experiments and consider challenges associated with the investigation of this class of non-domesticated monocotyledon systems. Our database, based on the Ruby on Rails framework, is rich in features including the retrieval of experimentally determined heat-responsive transcripts, mining for molecular markers (SSRs and SNPs), and weighted key word searches that allow access to annotation gathered on several levels including Pfam domains, GeneOntology and KEGG pathways. Well established plant genome sites such as The Arabidopsis Information Resource (TAIR) and the Rice Genome Annotation Project are interfaced by Dr. Zompo. With this project, we have initialized a valuable resource for plant biologists in general and the seagrass community in particular. The database is expected to grow together with more data to come in the near future, particularly with the recent initiation of the Zostera genome sequencing project.The Dr. Zompo database is available at http://drzompo.uni-muenster.de/

10.
Rev. ortop. traumatol. (Madr., Ed. impr.) ; 51(6): 319-324, nov.-dic. 2007. ilus, tab
Artigo em Es | IBECS | ID: ibc-65576

RESUMO

Objetivo. El objetivo de este estudio ha sido evaluar si la suplementación con eritropoyetina (EPO) permite una apropiada donación de sangre autóloga previa a una artroplastia electiva de cadera o rodilla, incluso en pacientes con niveles límite de hematocrito (Hcto) y hemoglobina (Hb). Material y método. Desde enero de 2000 hasta diciembre de 2001 fueron incluidos en este estudio 66 pacientes que requirieron artroplastia total de cadera o rodilla, a quienes se había inscrito previamente en un programa de autotransfusión preoperatoria. Los pacientes fueron clasificados en dos grupos teniendo en cuenta sus niveles de Hb: aquéllos con un nivel de Hb < 13 g/dl (grupo 1; 37 pacientes) recibieron EPO (10.000 UI, 3 veces por semana) durante el programa de autotransfusiones, mientras que a aquéllos con un nivel de Hb > 13 g/dl (grupo 2; 29 pacientes) no se les suministró EPO ni antes ni durante el programa de autotransfusión. A los pacientes de ambos grupos se les extrajo sangre una vez por semana durante un período de entre una y tres semanas, administrándoseles además hierro por vía oral. En todos los pacientes se evaluaron los valores de Hb y Hcto antes de la primera extracción de sangre (valores basales), en el período prequirúrgico y al alta, registrándose además la cantidad de sangre recogida y transfundida para cada grupo. Durante el estudio se excluyeron 20 pacientes por no cumplir los criterios de inclusión (grupo 1, n = 12; grupo 2, n = 8). Finalmente, se analizaron estadísticamente los datos correspondientes a 46 pacientes (grupo 1, n = 25; grupo 2, n = 21). Resultados. A pesar de que los valores basales de Hb y Hcto para el grupo 2 fueron significativamente más elevados que para el grupo 1 (p < 0,001), no se observaron diferencias entre ambos grupos en cuanto a sus niveles correspondientes durante el período preoperatorio, el postoperatorio y el momento del alta hospitalaria, ni tampoco en cuanto a la cantidad de sangre recogida y transfundida. Conclusiones. La diferencia en los niveles basales de Hb y Hcto observada entre los dos grupos fue completamente corregida gracias a la administración profiláctica de EPO durante el programa de autotransfusión preoperatoria, el cual se desarrolló de forma adecuada incluso en aquellos pacientes con niveles límite de Hb y Hcto


Purpose. The aim of this study was to determine whether erythropoyetin (EPO) supplementation permits an adequate autologous blood donation prior to elective hip or knee arthroplasty in patients with boundary hematocrit and hemoglobin (Hb) levels. Materials and methods. Between January 2000 and December 2001, sixty-six patients were included in this study who required total hip or knee arthroplasty and who had also been enrolled in a preoperative transfusion program. Patients were classified into two groups, taking into account their hemoglobin levels: those with Hb < 13 g/dl (group 1, 37 patients) received EPO (10.000 IU, 3 times a week) throughout the transfusion program whereas those with Hb > 13 g/dl (group 2, 29 patients) were not given EPO before or during the self-transfusion program. Blood was extracted from patients in both groups once a week for one to three weeks; all patients received oral iron supplementation. In all patients, median hemoglobin and hematocrit values were determined before the first blood extraction (baseline values), during the preoperative period and at discharge; a record was made of the amount of blood extracted and transfused for each group. Twenty patients were excluded during the study since they did not fulfill the inclusion criteria (group 1: n = 12; group 2: n = 8). Lastly, the data corresponding to 46 patients was statistically analyzed (group 1: n = 25; group 2: n = 21). Results. Although the median baseline hemoglobin and hematocrit values for group 2 were significantly higher than those for group 1 (p < 0.001), no differences were observed between both groups regarding their median levels during the preoperative and postoperative periods or at discharge. Nor any differences were observed regarding the amount of blood extracted and transfused. Conclusions. Differences observed in the baseline hemoglobin and hematocrit levels between the two groups were fully resolved thanks to the prophylactic administration of EPO during the preoperative self-transfusion program, which was concluded appropriately even for patients with boundary hemoglobin and hematocrit levels (AU)


Assuntos
Humanos , Artroplastia de Substituição/métodos , Eritropoetina/farmacocinética , Transfusão de Sangue Autóloga , Osteoartrite/cirurgia , Cuidados Pré-Operatórios/métodos
11.
Oncogene ; 25(29): 4110-5, 2006 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-16491120

RESUMO

In contrast to other cell cycle inhibitors, the tumor suppressor p16Ink4a is not detectable or expressed at very low levels in embryonic and adult mouse tissues, and therefore it has often been considered as a specialized checkpoint protein that does not participate in the control of normal cell cycle progression. However, Ink4a-/- mice possess increased thymus size and cellularity, thus suggesting the involvement of p16(Ink4a) in the control of thymocyte proliferation. In this study, we found increased numbers of CD8 and CD4 T lymphocytes in thymus and spleen from Ink4a-/- mice. Unexpectedly, this was not related to an increase in T-cell division rates, which were similar in lymphoid organs of Ink4a-/- and wild-type mice. In contrast, T-cell apoptosis rates were significantly decreased in thymus and spleen from Ink4a-/- mice. Moreover, whereas p16Ink4a-deficient and wild-type T cells were equally sensitive to Fas or TCR-mediated apoptosis, the former were clearly more resistant to apoptosis induced by oxidative stress or gamma irradiation. Our results indicate that p16Ink4a function is associated with T-cell apoptosis, and subsequently contributes to the control of T-cell population size in lymphoid organs.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Timo/imunologia , Proteína Supressora de Tumor p14ARF/imunologia , Animais , Apoptose/genética , Apoptose/imunologia , Apoptose/efeitos da radiação , Linfócitos T CD4-Positivos/citologia , Divisão Celular/genética , Divisão Celular/imunologia , Divisão Celular/efeitos da radiação , Sobrevivência Celular/genética , Sobrevivência Celular/imunologia , Sobrevivência Celular/efeitos da radiação , Inibidor p16 de Quinase Dependente de Ciclina , Raios gama , Camundongos , Camundongos Knockout , Tamanho do Órgão/imunologia , Tamanho do Órgão/efeitos da radiação , Estresse Oxidativo/genética , Estresse Oxidativo/imunologia , Estresse Oxidativo/efeitos da radiação , Receptores de Antígenos de Linfócitos T/imunologia , Timo/citologia , Timo/embriologia , Proteína Supressora de Tumor p14ARF/deficiência , Receptor fas/imunologia
12.
Bioorg Med Chem ; 12(5): 963-8, 2004 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-14980609

RESUMO

In the search of new compounds with antineoplastic activity, we have analysed the effect of several structural modifications on the nucleus 6-benzo[b]thiophenesulphonamide 1,1-dioxide on its cytotoxic activity on tumour cells. Lipophilic substituents on the sulphonamide group significantly increased the cytotoxic activity measured using a panel of human tumour cell lines. Only slight variations on cytotoxicity were obtained when the sulphonamide group occupied the position 5 of the system. The most active compound was the N-4-methoxyphenyl derivative 15, which showed GI(50) values of 1-9 nM against HT-29, CCRF-CEM, K-562 and MEL-AC cells and of 200 nM against HTB-54 cells. Free access to the 3-position of the heterocyclic system seems to be required to obtain cytotoxic derivatives. Derivative 15 was also active at the same level of commercial Doxorubicine against cultured normal human lung fibroblasts.


Assuntos
Antineoplásicos/síntese química , Sulfonamidas/síntese química , Tiofenos/síntese química , Antineoplásicos/farmacologia , Divisão Celular/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Concentração Inibidora 50 , Relação Estrutura-Atividade , Sulfonamidas/farmacologia , Tiofenos/farmacologia , Células Tumorais Cultivadas
13.
Oncogene ; 22(24): 3759-69, 2003 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-12802283

RESUMO

In this work, we describe the process of cell death induced by a series of new benzo(b)thiophenesulphonamide 1,1-dioxide derivatives (BTS) that have been selected as candidate antineoplastic drugs. Human leukaemic CCRF-CEM cells incubated with BTS undergo a typical apoptotic process that includes cell shrinkage, phosphatidylserine translocation to the cell surface, mitochondrial dysfunction, caspase activation, chromatin condensation and internucleosomal DNA degradation. Mitochondrial alterations included dissipation of the mitochondrial membrane potential, oxidation of the phospholipid cardiolipin, release of cytochrome c and uncoupling of the mitochondrial respiratory chain, leading to a decrease of the intracellular ATP pool. Activation of caspase-8, -9 and -3 takes place during BTS-induced apoptosis. Either the addition of the specific caspase-8 inhibitor Z-IETD-fmk, or the overexpression of the antiapoptotic protein Bcl-2 significantly prevented BTS-induced apoptosis, suggesting the involvement of both caspase-8-regulated and mitochondria-dependent signalling pathways in this process. BTS induce a significant increase in the production and accumulation of intracellular reactive oxygen species (ROS) that can be observed within minutes after drug addition. Moreover, cytochrome c release, caspase-3 activation and cell death can be completely abrogated by a previous incubation with the antioxidant N-acetyl-cysteine. These results suggest that ROS are essential mediators in BTS-induced apoptosis.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Sulfonamidas/farmacologia , Caspase 3 , Caspase 8 , Caspase 9 , Caspases/metabolismo , Humanos , Proteínas de Membrana/análise , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/fisiologia , Oligopeptídeos/farmacologia , Proteínas Proto-Oncogênicas/análise , Proteínas Proto-Oncogênicas c-bcl-2/análise , Tiofenos/farmacologia , Células Tumorais Cultivadas , Proteína Killer-Antagonista Homóloga a bcl-2 , Proteína X Associada a bcl-2 , Proteína bcl-X
14.
Br J Cancer ; 85(9): 1400-2, 2001 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-11720481

RESUMO

A series of benzo(b)thiophenesulfonamide 1,1-dioxide derivatives (BTS) have been designed and synthesized as candidate antineoplastic drugs. Several of these compounds have shown in vitro cytotoxic activity on leukaemic CCRF-CEM cells. The cytotoxic BTS, but not the inactive ones, were able to inhibit a tumour cell-specific NADH oxidase activity present in the membrane of CCRF-CEM cells.


Assuntos
Antineoplásicos/farmacologia , Complexos Multienzimáticos/antagonistas & inibidores , NADH NADPH Oxirredutases/antagonistas & inibidores , Compostos de Sulfonilureia/farmacologia , Tiofenos/farmacologia , Antineoplásicos/síntese química , Membrana Celular/efeitos dos fármacos , Membrana Celular/enzimologia , Meios de Cultura , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Cinética , Leucemia/patologia , Complexos Multienzimáticos/metabolismo , NADH NADPH Oxirredutases/metabolismo , Compostos de Sulfonilureia/síntese química , Tiofenos/síntese química , Células Tumorais Cultivadas
15.
Eur J Immunol ; 31(9): 2642-51, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11536162

RESUMO

Telomerase is a ribonucleoprotein complex responsible for the maintenance of the length of the telomeres during cell division, which is active in germ-line cells as well as in the vast majority of tumors but not in most normal tissues. The wide expression of the human telomerase catalytic subunit (hTERT) in tumors makes it an interesting candidate vaccine for cancer. hTERT-derived peptide 540-548 (hTERT(540)) has been recently shown to be recognized in an HLA-A*0201-restricted fashion by T cell lines derived from peptide-stimulated peripheral blood mononuclear cells (PBMC) from healthy donors. As a first step to the inclusion of this peptide in immunotherapy clinical trials, it is crucial to assess hTERT(540)-specific T cell reactivity in cancer patients as well as the ability of hTERT-specific CD8(+) T lymphocytes to recognize and lyse hTERT-expressing target cells. Here, we have analyzed the CD8(+) T cell response to peptide hTERT(540) in HLA-A*0201 melanoma patients by using fluorescent HLA-A*0201/hTERT(540) peptide tetramers. HLA-A*0201/hTERT(540) tetramer(+) CD8(+) T cells were readily detected in peptide-stimulated PBMC from a significant proportion of patients and could be isolated by tetramer-guided cell sorting. hTERT(540)-specific CD8(+) T cells were able to specifically recognize HLA-A*0201 cells either pulsed with peptide or transiently transfected with a minigene encoding the minimal epitope. In contrast, they failed to recognize hTERT-expressing HLA-A*0201(+) target cells. Furthermore, in vitro proteasome digestion studies revealed inadequate hTERT processing. Altogether, these results raise questions on the use of hTERT(540) peptide for cancer immunotherapy.


Assuntos
Apresentação de Antígeno , Antígenos de Neoplasias/imunologia , Melanoma/imunologia , Fragmentos de Peptídeos/imunologia , Linfócitos T Citotóxicos/imunologia , Telomerase/imunologia , Linhagem Celular , Células Clonais , Cisteína Endopeptidases/farmacologia , Testes Imunológicos de Citotoxicidade , Epitopos/imunologia , Citometria de Fluxo , Antígenos HLA-A/imunologia , Humanos , Complexos Multienzimáticos/farmacologia , Fragmentos de Peptídeos/genética , Complexo de Endopeptidases do Proteassoma , Telomerase/genética , Transfecção , Células Tumorais Cultivadas
16.
Blood ; 98(3): 597-603, 2001 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-11468156

RESUMO

In most human somatic cells telomeres progressively shorten with each cell division eventually leading to chromosomal instability and cell senescence. The loss of telomere repeats with cell divisions may also limit the replicative life span of antigen-specific T lymphocytes. Recent studies have shown that the replicative life span of various primary human cells can be prolonged by induced expression of the telomerase reverse transcriptase (hTERT) gene. To test whether introduction of hTERT can extend the life span of primary human T lymphocytes, naive CD8(+) T lymphocytes were transfected with retroviral vectors containing the hTERT gene. Transduced T-cell clones expressed high levels of telomerase and either maintained or elongated their telomere lengths upon culture for extended periods of time. Two of the transduced subclones retained a normal cloning efficiency for more than 170 population doublings (PDs). In contrast, T-cell clones transfected with control vectors exhibited progressive telomere length shortening and stopped proliferation at around 108 PDs. Telomerase-positive T clones had a normal 46,XY karyotype, maintained their cytotoxic properties, and showed very little staining for the apoptotic marker annexin-V. These results indicate that ectopic hTERT gene expression is capable of extending the replicative life span of primary human CD8(+) cytotoxic T lymphocytes. (Blood. 2001;98:597-603)


Assuntos
Linfócitos T CD8-Positivos/metabolismo , Divisão Celular/efeitos dos fármacos , Telomerase/genética , Transdução Genética , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/enzimologia , Técnicas de Cultura de Células , Sobrevivência Celular/efeitos dos fármacos , Células Clonais , Replicação do DNA/efeitos dos fármacos , Proteínas de Ligação a DNA , Humanos , Memória Imunológica/fisiologia , Hibridização in Situ Fluorescente , Telomerase/biossíntese , Telomerase/farmacologia , Telômero/metabolismo , Telômero/ultraestrutura
17.
Eur J Immunol ; 31(2): 459-66, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11180110

RESUMO

Cycling lymphocytes may express the enzyme telomerase which is involved in maintenance of telomere length and cell proliferation potential. In CD8(+) T cells freshly isolated from peripheral blood, we found that in vivo cycling cells expressed HLA-DR. Furthermore, CD28-positive cells are known to have longer telomeres than CD28-negative T cells. Therefore we used HLA-DR- and CD28-specific antibodies to sort CD8(+) T cells and measure telomerase activity ex vivo. Relatively high levels of telomerase activity were found in HLA-DR/CD28 double-positive cells. In contrast, HLA-DR-negative and CD28-negative cells had almost no telomerase activity. In summary, HLA-DR expression correlates with proliferation, and CD28 expression with proliferative potential. We have previously identified that ex vivo cytolytic CD8(+) T cells are CD56 (NCAM) positive. Here we show that HLA-DR(+) cells were rarely CD56(+) and vice versa. This demonstrates that telomerase-expressing and cytolytic CD8(+) T cells can be separated on the basis of the cell surface markers HLA-DR and CD56. Thus, activated CD8(+) T cells specialize and exert distinct functions correlating with surface molecule expression.


Assuntos
Antígenos CD28/análise , Linfócitos T CD8-Positivos/química , Citotoxicidade Imunológica , Antígenos HLA-DR/análise , Telomerase/metabolismo , Antígeno CD56/análise , Linfócitos T CD8-Positivos/imunologia , Humanos , Antígeno Ki-67/análise , Ativação Linfocitária , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/análise
18.
J Immunol ; 165(9): 4978-84, 2000 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11046025

RESUMO

Like most somatic human cells, T lymphocytes have a limited replicative life span. This phenomenon, called senescence, presents a serious barrier to clinical applications that require large numbers of Ag-specific T cells such as adoptive transfer therapy. Ectopic expression of hTERT, the human catalytic subunit of the enzyme telomerase, permits fibroblasts and endothelial cells to avoid senescence and to become immortal. In an attempt to immortalize normal human CD8(+) T lymphocytes, we infected bulk cultures or clones of these cells with a retrovirus transducing an hTERT cDNA clone. More than 90% of transduced cells expressed the transgene, and the cell populations contained high levels of telomerase activity. Measuring the content of total telomere repeats in individual cells (by flowFISH) we found that ectopic hTERT expression reversed the gradual loss of telomeric DNA observed in control populations during long term culture. Telomere length in transduced cells reached the levels observed in freshly isolated normal CD8(+) lymphocytes. Nevertheless, all hTERT-transduced populations stopped to divide at the same time as nontransduced or vector-transduced control cells. When kept in IL-2 the arrested cells remained alive. Our results indicate that hTERT may be required but is not sufficient to immortalize human T lymphocytes.


Assuntos
Linfócitos T CD8-Positivos/enzimologia , Linfócitos T CD8-Positivos/imunologia , Domínio Catalítico , Linhagem Celular Transformada , Ativação Linfocitária , RNA , Telomerase/biossíntese , Telômero/metabolismo , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/metabolismo , Domínio Catalítico/genética , Técnicas de Cultura de Células , Divisão Celular/genética , Divisão Celular/imunologia , Separação Celular , Proteínas de Ligação a DNA , Humanos , Ativação Linfocitária/genética , Retroviridae/genética , Retroviridae/imunologia , Linfócitos T Citotóxicos/citologia , Linfócitos T Citotóxicos/enzimologia , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo , Telomerase/genética , Transdução Genética
19.
J Org Chem ; 65(18): 5600-8, 2000 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-10970298

RESUMO

The reaction between dry arenediazonium o-benzenedisulfonimides 1 and sodium thiolates in anhydrous methanol represents an efficient and safe procedure, of general validity, for the preparation of unfunctionalized or variously functionalized alkyl aryl and diaryl sulfides. As a rule, the reaction temperature was maintained at 0-5 degrees C for the alkylthiodediazoniations and at room temperature (20-25 degrees C) for the arylthiodediazoniations. The sulfide yields are generally high; of the 63 considered examples, 43 gave yields greater than 80% and 13 were between 70% and 80%. Lower yields were obtained only when sterically hindered diazonium salts or thiols were used. A good amount of the o-benzenedisulfonimide (8) was always recovered from the reactions and could be reused to prepare salts 1. The copious experimental data collected in homogeneous conditions have offered several starting points for the study of the mechanism of these reactions.

20.
Bioorg Med Chem Lett ; 9(16): 2321-4, 1999 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-10476861

RESUMO

Starting from a 3D-model for the antineoplastic activity of diarylsulfonylureas several new features were proposed and tested. Both types of assayed compounds, the N-(2-pyridylsulfonyl)urea and N-(2-pyridylsulfenyl)urea derivatives, inhibited by 50% the growth of the CCRF-CEM cell line at a dosage near to 1 microM. The N -(2-pyrimidinyl) derivative of the sulfenylurea 6c showed a better profile against HT-29, K-562 and HTB-54 tumor cell lines than the corresponding sulfonylurea 6b. Structural modifications on aryl systems affected differently to the cytotoxic activity shown by the compounds against each cell line.


Assuntos
Antineoplásicos/química , Pirimidinas/química , Ureia/análogos & derivados , Antineoplásicos/síntese química , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Pirimidinas/síntese química , Células Tumorais Cultivadas , Ureia/síntese química , Ureia/química
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