RESUMEN
BACKGROUND: Mycosis fungoides (MF) is the major subtype of cutaneous T-cell lymphomas (CTCL). It usually has a prolonged indolent clinical course with a minority of cases acquiring a more aggressive biological profile and resistance to conventional therapies, partially attributed to the persistent activation of nuclear factor-kappa B (NF-κB) pathway. In the last decade, several papers suggested an important role for the FK506-binding protein 51 (FKBP51), an immunophilin initially cloned in lymphocytes, in the control of NF-κB pathway in different types of human malignancies. OBJECTIVES: We aimed to investigate the possible value of FKBP51 expression as a new reliable marker of outcome in patients with MF. METHODS: We assessed by immunohistochemistry (IHC) FKBP51 expression in 44 patients with MF, representative of different stages of the disease. Immunohistochemical results were subsequently confirmed at mRNA level with quantitative PCR (qPCR) in a subset of enrolled patients. In addition, IHC and qPCR served to study the expression of some NF-κB-target genes, including the tumour necrosis factor receptor-associated factor 2 (TRAF2). RESULTS: Our results show that FKBP51 was expressed in all evaluated cases, with the highest level of expression characterizing MFs with the worst prognosis. Moreover, a significant correlation subsisted between FKBP51 and TRAF2 IHC expression scores. CONCLUSIONS: We hypothesize a role for FKBP51 as a prognostic marker for MF and suggest an involvement of this immunophilin in deregulated NF-κB pathway of this CTCL.
Asunto(s)
Micosis Fungoide/metabolismo , ARN Mensajero/metabolismo , Factor 2 Asociado a Receptor de TNF/metabolismo , Proteínas de Unión a Tacrolimus/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores/metabolismo , Dermatitis/metabolismo , Femenino , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Micosis Fungoide/genética , Pronóstico , Piel/metabolismo , Factor 2 Asociado a Receptor de TNF/genética , Proteínas de Unión a Tacrolimus/genética , Timo/metabolismoRESUMEN
The authors present three cases of symptomatic, large, benign, nonparasitic hepatic cysts. The diagnosis was determined by US and CT scan, the latter enabling differential diagnosis with neoplastic or hydatid cysts. All patients were treated with open hepatic resection. In 2 cases, laparoscopy was performed to enable complete diagnosis. The authors used LigaSure™ (Covidien, USA) instrument, avoiding bleeding complications and reducing surgery time. Histological examination confirmed the diagnosis of benign cysts. CT follow-up at 6 months and 1 year demonstrated the efficacy of the surgery, with no recurrences.
Asunto(s)
Quistes/diagnóstico , Quistes/cirugía , Hepatectomía , Hepatopatías/diagnóstico , Hepatopatías/cirugía , Anciano , Quistes/patología , Diagnóstico Diferencial , Femenino , Estudios de Seguimiento , Hepatectomía/métodos , Humanos , Hepatopatías/patología , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
Information on subcortical ischaemic changes (SIC) in young hypertensive patients is scarce. We evaluated the frequency of SIC at magnetic resonance imaging (MRI), the possible effect on cognition of these patients, and the role of plasma markers known as indicators of endothelial and haemostatic activation. Inclusion criteria were age Asunto(s)
Isquemia Encefálica/psicología
, Cognición/fisiología
, Endotelio Vascular/metabolismo
, Hemostasis/fisiología
, Hipertensión/psicología
, Adulto
, Factores de Edad
, Biomarcadores/sangre
, Encéfalo/metabolismo
, Encéfalo/patología
, Isquemia Encefálica/sangre
, Isquemia Encefálica/patología
, Endotelio Vascular/patología
, Femenino
, Humanos
, Hipertensión/sangre
, Hipertensión/patología
, Imagen por Resonancia Magnética/métodos
, Masculino
, Persona de Mediana Edad
, Pruebas Neuropsicológicas
RESUMEN
The activity of NF-kappaB/Rel transcription factors can downmodulate apoptosis in normal and neoplastic cells of the hematologic and other compartments, contributing in maintaining neoplastic clone survival and impairing response to therapy. Alterations in nfkappab or ikappaB genes are documented in some hematologic neoplasias, while in others dysfunction in NF-kappaB/Rel-activating signaling pathways can be recognized. The prosurvival properties of NF-kappaB/Rel appear to rely on the induced expression of molecules (caspase inhibitors, Bcl2 protein family members, etc.), which interfere with the apoptosis pathway. Constitutive NF-kappaB/Rel activity in some hematologic malignancies could be advantageous for neoplastic clone expansion by counteracting stress stimuli (consumption of growth factors and metabolites) and immune system-triggered apoptosis; it is furthermore likely to play a central role in determining resistance to therapy. Based on this evidence, NF-kappaB/Rel-blocking approaches have been introduced in antineoplastic strategies. The identification of NF-kappaB/Rel target genes relevant for survival in specific neoplasias is required in order to address tailored therapies and avoid possible detrimental effects due to widespread NF-kappaB/Rel inhibition. Moreover, comparative analyses of normal hematopoietic progenitors and neoplastic cell sensitivities to inhibitors of NF-kappaB/Rel and their target genes will allow to evaluate the impact of these tools on normal bone marrow.
Asunto(s)
Apoptosis , Neoplasias Hematológicas/patología , Células Madre Hematopoyéticas/patología , FN-kappa B/fisiología , Proteínas Proto-Oncogénicas c-rel/fisiología , Animales , Humanos , Transducción de Señal/efectos de los fármacosRESUMEN
Numerous studies have indicated that BMP4 signaling is involved in the regulation of the early steps of development. In mouse embryonic stem cells (ESCs), BMP4 is crucial to sustain pluripotency and blocks differentiation towards neural fate. Here, through a systematic analysis of miRNAs in ESCs, we establish that BMP4 signaling regulates miR-23a, 27a and 24-2, through the recruitment of phospho-Smads at the promoter of the gene encoding this miRNA cluster. Suppression of miR-23a/b, 27a/b and 24 does not affect self-renewal or pluripotency, but induces an evident change of ESC differentiation, with a significant increase of the cells undergoing apoptosis after the transition from ESCs to epiblast stem cells (EpiSCs). BMP4 has been previously reported to cause apoptosis during ESC differentiation. By blocking BMP4 signaling, we completely prevent the apoptosis induced by suppression of the miRs. This suggests that the effects of miR suppression are the result of enhanced BMP4 signaling. This hypothesis is further supported by the observation that Smad5, the transcription factor downstream of the BMP4 receptor, is targeted by the miRNAs of the 23a and 23b clusters. Altogether, our results highlight the existence of a regulatory loop, involving Smad5 and the miR-23a clusters, that modulates the apoptotic response of ESCs to BMP4.
Asunto(s)
Proteína Morfogenética Ósea 4/farmacología , Células Madre Embrionarias/citología , Células Madre Embrionarias/metabolismo , MicroARNs/fisiología , Animales , Apoptosis/efectos de los fármacos , Apoptosis/genética , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/genética , Línea Celular , Células Madre Embrionarias/efectos de los fármacos , Ratones , MicroARNs/genéticaRESUMEN
-Doppler-derived parameters of transmitral flow are useful indices of diastolic dysfunction in the hypertensive heart. Different degrees of myocardial involvement in hypertensive heart can be detected by videodensitometric myocardial textural analysis. The aim of this study was to compare Doppler-derived and ultrasonic videodensitometric parameters in the differentiation of healthy hearts from hypertensive hearts. We compared a group of age-matched (59+/-9 years) male essential hypertensive patients (n=53) with normotensive healthy subjects as controls (n=32). All subjects provided ambulatory blood pressure measurements for the evaluation of 24-hour mean systolic and diastolic blood pressure. A transmitral flow Doppler analysis was performed on all subjects. A quantitative analysis of the echocardiographic digitized imaging was performed with the help of a calibrated digitization system to calculate the septum and the posterior wall textural parameters. The myocardial mean gray level (MGL) was calculated to derive the cyclic variation index (CVI): (MGLend-diastolic-MGLend-systolic)/MGLend-diastolic x100. When compared with controls, the hypertensive patients showed a significantly lower CVI for both septum (-11.1+/-26.8% versus 34. 7+/-16.3%; P<0.001) and posterior wall (-11.2+/-27.6% versus 38. 2+/-15.4%; P<0.001). Individual analyses for the ratio of peak transmitral flow velocity in early diastole to the peak transmitral flow velocity in late diastole showed that only 24% of the patients (13/53) were discriminated from normal subjects by this parameter. Individual analyses for CVI, however, at both septum and posterior wall levels, showed that 74% of the patients (39/53) were discriminated from normal subjects by this second parameter. In comparison with Doppler-derived indices of diastolic filling, the videodensitometric parameters showed a significantly higher ability to discriminate between hypertensive subjects and normal controls.
Asunto(s)
Ecocardiografía Doppler , Hipertensión/diagnóstico por imagen , Hipertrofia Ventricular Izquierda/diagnóstico por imagen , Procesamiento de Imagen Asistido por Computador , Anciano , Monitoreo Ambulatorio de la Presión Arterial , Interpretación Estadística de Datos , Densitometría , Diástole , Humanos , Hipertensión/fisiopatología , Hipertrofia Ventricular Izquierda/fisiopatología , Masculino , Persona de Mediana Edad , Sístole , Función Ventricular Izquierda , Grabación en VideoRESUMEN
The levels of tumour necrosis factor receptor (TNF-R) superfamily members can be altered in lymphoid leukemias, indicating a possible role of such molecules in the biology of these neoplasias. In B chronic lymphocytic leukemia cells, the CD40/CD40L system has been shown to be effective in inhibiting the apoptotic response to fludarabine. The modulation of apoptosis relied on the CD40-induced activity of NF-kappaB/Rel transcription factors. The anti-apoptotic effect of CD40 was abolished using a phosphorothioate kappaB decoy oligodeoxynucleotide. These findings illustrate an example of the biological activity of TNF-R-like molecules in leukemias. They also show the influence of NF-kappaB/Rel activity on leukemic cell response to apoptogenic agents.
Asunto(s)
Antineoplásicos/farmacología , Apoptosis , Antígenos CD40/fisiología , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Leucemia Linfocítica Crónica de Células B/inmunología , FN-kappa B/fisiología , Vidarabina/análogos & derivados , Apoptosis/inmunología , Apoptosis/fisiología , Humanos , Leucemia Linfocítica Crónica de Células B/patología , FN-kappa B/antagonistas & inhibidores , Proteínas Oncogénicas v-rel/antagonistas & inhibidores , Proteínas Oncogénicas v-rel/fisiología , Células Tumorales Cultivadas , Vidarabina/farmacologíaRESUMEN
A group of 20 middle-class women between 20 and 40 yr. of age and in the third trimester of pregnancy was compared with a control group of 20 non-pregnant women for cutaneous sensitivity (to a tickle) and for modifications of body schema which were hypothesized to occur during pregnancy. Latency and actual duration were considered in the perception of the tickle. Body schema were studied using two of Fisher's tests, Body Prominence and Body Cathexis. Pregnancy leads to modifications in sensitivity to tickle, specifically with regard to the right half of the body and to some extent in body schema.
Asunto(s)
Imagen Corporal , Embarazo , Tacto , Adulto , Femenino , Lateralidad Funcional , Humanos , Tiempo de Reacción , Umbral SensorialRESUMEN
Melanoma is the most aggressive skin cancer; there is no cure in advanced stages. Identifying molecular participants in melanoma progression may provide useful diagnostic and therapeutic tools. FK506 binding protein 51 (FKBP51), an immunophilin with a relevant role in developmental stages, is highly expressed in melanoma and correlates with aggressiveness and therapy resistance. We hypothesized a role for FKBP51 in melanoma invasive behaviour. FKBP51 promoted activation of epithelial-to-mesenchymal transition (EMT) genes and improved melanoma cell migration and invasion. In addition, FKBP51 induced some melanoma stem cell (MCSC) genes. Purified MCSCs expressed high EMT genes levels, suggesting that genetic programs of EMT and MCSCs overlap. Immunohistochemistry of samples from patients showed intense FKBP51 nuclear signal and cytoplasmic positivity for the stem cell marker nestin in extravasating melanoma cells and metastatic brains. In addition, FKBP51 targeting by small interfering RNA (siRNA) prevented the massive metastatic substitution of liver and lung in a mouse model of experimental metastasis. The present study provides evidence that the genetic programs of cancer stemness and invasiveness overlap in melanoma, and that FKBP51 plays a pivotal role in sustaining such a program.
Asunto(s)
Regulación Neoplásica de la Expresión Génica , Melanoma/patología , Células Madre Neoplásicas/metabolismo , Neoplasias Cutáneas/patología , Proteínas de Unión a Tacrolimus/genética , Animales , Biomarcadores/metabolismo , Línea Celular Tumoral , Movimiento Celular , Transición Epitelial-Mesenquimal/genética , Humanos , Proteínas de Filamentos Intermediarios/genética , Proteínas de Filamentos Intermediarios/metabolismo , Melanoma/genética , Melanoma/metabolismo , Ratones , Invasividad Neoplásica , Neoplasias Experimentales , Células Madre Neoplásicas/patología , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Nestina , ARN Interferente Pequeño/genética , Transducción de Señal , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/metabolismo , Proteínas de Unión a Tacrolimus/antagonistas & inhibidores , Proteínas de Unión a Tacrolimus/metabolismoRESUMEN
TNF receptor-associated protein 1 (TRAP1), the main mitochondrial member of the heat shock protein (HSP) 90 family, is induced in most tumor types and is involved in the regulation of proteostasis in the mitochondria of tumor cells through the control of folding and stability of selective proteins, such as Cyclophilin D and Sorcin. Notably, we have recently demonstrated that TRAP1 also interacts with the regulatory protein particle TBP7 in the endoplasmic reticulum (ER), where it is involved in a further extra-mitochondrial quality control of nuclear-encoded mitochondrial proteins through the regulation of their ubiquitination/degradation. Here we show that TRAP1 is involved in the translational control of cancer cells through an attenuation of global protein synthesis, as evidenced by an inverse correlation between TRAP1 expression and ubiquitination/degradation of nascent stress-protective client proteins. This study demonstrates for the first time that TRAP1 is associated with ribosomes and with several translation factors in colon carcinoma cells and, remarkably, is found co-upregulated with some components of the translational apparatus (eIF4A, eIF4E, eEF1A and eEF1G) in human colorectal cancers, with potential new opportunities for therapeutic intervention in humans. Moreover, TRAP1 regulates the rate of protein synthesis through the eIF2α pathway either under basal conditions or under stress, favoring the activation of GCN2 and PERK kinases, with consequent phosphorylation of eIF2α and attenuation of cap-dependent translation. This enhances the synthesis of selective stress-responsive proteins, such as the transcription factor ATF4 and its downstream effectors BiP/Grp78, and the cystine antiporter system xCT, thereby providing protection against ER stress, oxidative damage and nutrient deprivation. Accordingly, TRAP1 silencing sensitizes cells to apoptosis induced by novel antitumoral drugs that inhibit cap-dependent translation, such as ribavirin or 4EGI-1, and reduces the ability of cells to migrate through the pores of transwell filters. These new findings target the TRAP1 network in the development of novel anti-cancer strategies.
Asunto(s)
Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Proteínas de Choque Térmico/metabolismo , Biosíntesis de Proteínas , Estrés Fisiológico , Factor 1 Asociado a Receptor de TNF/metabolismo , Neoplasias Colorrectales/genética , Regulación hacia Abajo , Chaperón BiP del Retículo Endoplásmico , Factor 2 Eucariótico de Iniciación/metabolismo , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Células HCT116 , Humanos , Neoplasias/metabolismo , Neoplasias/patología , Unión Proteica , Proteolisis , Ribosomas/metabolismo , Transducción de Señal , UbiquitinaciónRESUMEN
FK506 binding protein 51 (FKBP51) is an immunophilin physiologically expressed in lymphocytes. Very recently, aberrant expression of this protein was found in melanoma; FKBP51 expression correlates with melanoma aggressiveness and is maximal in metastatic lesions. FKBP51 promotes NF-κB activation and is involved in the resistance to genotoxic agents, including anthracyclines and ionizing radiation. FKBP51 is a cochaperone with peptidyl-prolyl isomerase activity that regulates several biological processes through protein-protein interaction. There is increasing evidence that FKBP51 hyperexpression is associated with cancer and this protein has a relevant role in sustaining cell growth, malignancy, and resistance to therapy. There is also evidence that FKBP ligands are potent anticancer agents, in addition to their immunosuppressant activity. In particular, rapamycin and its analogs have shown antitumor activity across a variety of human cancers in clinical trials. Although, classically, rapamycin actions are ascribed to inhibition of mTOR, recent studies indicate FKBP51 is also an important molecular determinant of the drug's anticancer activity. The aim of this article is to review the functions of FKBP51, especially in view of the recent findings that this protein is a potential oncogene when deregulated and a candidate target for signaling therapies against cancer.
Asunto(s)
Antineoplásicos/uso terapéutico , Inmunosupresores/uso terapéutico , Neoplasias/tratamiento farmacológico , Proteínas de Unión a Tacrolimus/metabolismo , Antineoplásicos/metabolismo , Apoptosis/efectos de los fármacos , Humanos , Inmunosupresores/metabolismo , Linfocitos/citología , Linfocitos/efectos de los fármacos , Linfocitos/metabolismo , Melanoma/tratamiento farmacológico , Melanoma/metabolismo , Melanoma/patología , FN-kappa B/metabolismo , Neoplasias/metabolismo , Neoplasias/patologíaRESUMEN
Contrast-induced nephropathy accounts for >10% of all causes of hospital-acquired renal failure, causes a prolonged in-hospital stay and represents a powerful predictor of poor early and late outcome. Mechanisms of contrast-induced nephropathy are not completely understood. In vitro data suggests that contrast media (CM) induces a direct toxic effect on renal tubular cells through the activation of the intrinsic apoptotic pathway. It is unclear whether this effect has a role in the clinical setting. In this work, we evaluated the effects of CM both in vivo and in vitro. By analyzing urine samples obtained from patients who experienced contrast-induced acute kidney injury (CI-AKI), we verified, by western blot and immunohistochemistry, that CM induces tubular renal cells apoptosis. Furthermore, in cultured cells, CM caused a dose-response increase in reactive oxygen species (ROS) production, which triggered Jun N-terminal kinases (JNK1/2) and p38 stress kinases marked activation and thus apoptosis. Inhibition of JNK1/2 and p38 by different approaches (i.e. pharmacological antagonists and transfection of kinase-death mutants of the upstream p38 and JNK kinases) prevented CM-induced apoptosis. Interestingly, N-acetylcysteine inhibited ROS production, and thus stress kinases and apoptosis activation. Therefore, we conclude that CM-induced tubular renal cells apoptosis represents a key mechanism of CI-AKI.
Asunto(s)
Lesión Renal Aguda/patología , Apoptosis/efectos de los fármacos , Medios de Contraste/efectos adversos , Túbulos Renales/patología , Transducción de Señal/efectos de los fármacos , Lesión Renal Aguda/inducido químicamente , Adulto , Anciano , Anciano de 80 o más Años , Caspasa 3/metabolismo , Células Cultivadas , Pruebas de Enzimas , Femenino , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Túbulos Renales/efectos de los fármacos , Masculino , Persona de Mediana Edad , Especies Reactivas de Oxígeno/metabolismo , Proteína Destructora del Antagonista Homólogo bcl-2/metabolismoAsunto(s)
Apoptosis , Proteínas Portadoras/fisiología , Leucemia de Células B/patología , Proteínas Adaptadoras Transductoras de Señales , Proteínas Reguladoras de la Apoptosis , Proteínas Portadoras/metabolismo , Línea Celular Tumoral , Supervivencia Celular , Relación Dosis-Respuesta a Droga , Humanos , Immunoblotting , Leucemia de Células B/metabolismo , Oligonucleótidos/farmacología , Oligonucleótidos Antisentido/química , Estructura Terciaria de Proteína , ARN/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa InversaAsunto(s)
Antígenos CD34/metabolismo , Antineoplásicos Fitogénicos/farmacología , Apoptosis/efectos de los fármacos , Etopósido/farmacología , Sangre Fetal/efectos de los fármacos , FN-kappa B/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-rel/antagonistas & inhibidores , Enfermedad Aguda , Sangre Fetal/metabolismo , Humanos , Células Jurkat/efectos de los fármacos , Células Jurkat/patología , FN-kappa B/genética , Oligonucleótidos/farmacología , Proteínas Proto-Oncogénicas c-rel/genética , Transcripción Genética/efectos de los fármacos , TransfecciónRESUMEN
FK506-binding protein 51 (FKBP51) is an immunophilin with isomerase activity, which performs important biological functions in the cell. It has recently been involved in the apoptosis resistance of malignant melanoma. The aim of this study was to investigate the possible role of FKBP51 in the control of response to ionizing radiation (Rx) in malignant melanoma. FKBP51-silenced cells showed reduced clonogenic potential after irradiation compared with non-silenced cells. After Rx, we observed apoptosis in FKBP51-silenced cells and autophagy in non-silenced cells. The FKBP51-controlled radioresistance mechanism involves NF-kappaB. FKBP51 was required for the activation of Rx-induced NF-kappaB, which in turn inhibited apoptosis by stimulating X-linked inhibitor of apoptosis protein and promoting authophagy-mediated Bax degradation. Using a tumor-xenograft mouse model, the in vivo pretreatment of tumors with FKBP51-siRNA provoked massive apoptosis after irradiation. Immunohistochemical analysis of 10 normal skin samples and 80 malignant cutaneous melanomas showed that FKBP51 is a marker of melanocyte malignancy, correlating with vertical growth phase and lesion thickness. Finally, we provide evidence that FKBP51 targeting radiosensitizes cancer stem/initiating cells. In conclusion, our study identifies a possible molecular target for radiosensitizing therapeutic strategies against malignant melanoma.
Asunto(s)
Apoptosis , Melanoma/radioterapia , Radiación Ionizante , Proteínas de Unión a Tacrolimus/fisiología , Animales , Proteínas Reguladoras de la Apoptosis/metabolismo , Beclina-1 , Línea Celular Tumoral , Humanos , Melanoma/metabolismo , Melanoma/patología , Ratones , Ratones Desnudos , FN-kappa B/metabolismo , ARN Interferente Pequeño/metabolismo , Proteínas de Unión a Tacrolimus/genética , Proteínas de Unión a Tacrolimus/metabolismo , Trasplante Heterólogo , Proteína Inhibidora de la Apoptosis Ligada a X/metabolismo , Proteína X Asociada a bcl-2/metabolismoRESUMEN
The aim is to determine the monocyte count performance of the Bayer Diagnostics ADVIA120 and Coulter LH 750 automated haematology analysers and the results obtained by these two instruments were compared with those provided by Becton Dickinson FACScan flow cytometer using the combination of CD45/CD14 MoAb. Linearity and imprecision were also evaluated. The linearity of both instruments was good. Coulter LH 750 showed better precision (4.3%) than ADVIA 120 (9.0%) both within and between batch. A significant correlation (r = 0.973) was found between the LH 750 and the flow cytometry method, while a modest one was observed between the latter and the ADVIA 120 (r = 0.880). When comparing the percentage of monocytes by means of one-way anova and Tukey test, it was found that the LH 750 provided the closest results in comparison with flow cytometry, with no statistical difference between the means (mean difference MO% = 0.6); however the difference was statistically different between the ADVIA 120 and flow cytometry (mean difference MO% = -4.06). These data were confirmed by Altman-Bland and Deming regression analyses.
Asunto(s)
Pruebas Hematológicas/instrumentación , Monocitos/citología , Automatización , Células Sanguíneas/citología , Citometría de Flujo , Pruebas Hematológicas/normas , Humanos , Recuento de Leucocitos/instrumentación , Reproducibilidad de los ResultadosRESUMEN
In the present work we analyzed the proliferative response of T lymphocytes from 11 atopic patients stimulated in vitro via either the CD2 or the CD3 pathway of cell activation. In both cases we found a significant decrease of thymidine incorporation in cell DNA in comparison with T cells from normal donors. The mechanism of this impaired proliferative response was analyzed. Atopic patients' T cells were found to secrete low quantities of interleukin 2 (IL2) and to express low amounts of Tac antigen, measured as both a percentage of Tac-positive cells and a mean fluorescence intensity of Tac antigen per cell. Addition of recombinant IL2 to cultures completely restored both cell proliferative response and Tac antigen expression. This effect was specific of IL2 since addition of IL1 or IL4 did not significantly affect T cell proliferative response. We conclude that atopic patients' T lymphocytes have a defect in both CD2 and CD3 pathways of cell activation relying on impairment of IL2 production, without involving IL2 responsiveness or other lymphokine defects.
Asunto(s)
Antígenos de Diferenciación de Linfocitos T/fisiología , Hipersensibilidad/inmunología , Interleucina-2/fisiología , Activación de Linfocitos , Receptores de Antígenos de Linfocitos T/fisiología , Receptores Inmunológicos/fisiología , Linfocitos T/inmunología , Adulto , Antígenos CD2 , Complejo CD3 , Humanos , Interleucina-1/farmacología , Interleucina-2/biosíntesis , Interleucina-4/farmacología , Receptores de Interleucina-2/metabolismo , Proteínas Recombinantes , Transducción de SeñalRESUMEN
Two groups of subjects were examined: trained athletes (group A) and a sedentary control group (group B). The subjects performed submaximal bicycle exercise in the semisupine position to evaluate the differences between the two groups with regard to cardiovascular response during exercise and recovery and to point out all the changes due to training. During the first part of exercise, cardiac output increased contemporary with heart rate and myocardial contractility as shown by the trend of the ejection fraction, higher in group A, under the same level of total vascular peripheral resistances. Later there was an increase of cardiac output for a further increase of heart rate and cardiac inotropism due to the homeometric mechanism. During recovery the heart rate and peripheral vascular resistance reduction led to an increase of venous return which set up the Frank-Starling mechanism via an increase of left ventricular dimensions. These adjustments were more efficient in group A. During exercise and recovery the heart rate-pressure product was constantly lower in group A with a significant difference to group B. Therefore, trained athletes' myocardium is more efficient than that of the sedentary group because it performs an external work load with a lower oxygen consumption.