Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Ann Oncol ; 33(9): 916-928, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35690221

RESUMEN

BACKGROUND: Anti-CD19 chimeric antigen receptor T-cell immunotherapy (CAR-T) is now a standard treatment of relapsed or refractory B-cell non-Hodgkin lymphomas; however, a significant portion of patients do not respond to CAR-T and/or experience toxicities. Lymphodepleting chemotherapy is a critical component of CAR-T that enhances CAR-T-cell engraftment, expansion, cytotoxicity, and persistence. We hypothesized that the lymphodepletion regimen might affect the safety and efficacy of CAR-T. PATIENTS AND METHODS: We compared the safety and efficacy of lymphodepletion using either fludarabine/cyclophosphamide (n = 42) or bendamustine (n = 90) before tisagenlecleucel in two cohorts of patients with relapsed or refractory large B-cell lymphomas treated consecutively at three academic institutions in the United States (University of Pennsylvania, n = 90; Oregon Health & Science University, n = 35) and Europe (University of Vienna, n = 7). Response was assessed using the Lugano 2014 criteria and toxicities were assessed by the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 and, when possible, the American Society for Transplantation and Cellular Therapy (ASTCT) consensus grading. RESULTS: Fludarabine/cyclophosphamide led to more profound lymphocytopenia after tisagenlecleucel infusion compared with bendamustine, although the efficacy of tisagenlecleucel was similar between the two groups. We observed significant differences, however, in the frequency and severity of adverse events. In particular, patients treated with bendamustine had lower rates of cytokine release syndrome and neurotoxicity. In addition, higher rates of hematological toxicities were observed in patients receiving fludarabine/cyclophosphamide. Bendamustine-treated patients had higher nadir neutrophil counts, hemoglobin levels, and platelet counts, as well as a shorter time to blood count recovery, and received fewer platelet and red cell transfusions. Fewer episodes of infection, neutropenic fever, and post-infusion hospitalization were observed in the bendamustine cohort compared with patients receiving fludarabine/cyclophosphamide. CONCLUSIONS: Bendamustine for lymphodepletion before tisagenlecleucel has efficacy similar to fludarabine/cyclophosphamide with reduced toxicities, including cytokine release syndrome, neurotoxicity, infectious and hematological toxicities, as well as reduced hospital utilization.


Asunto(s)
Clorhidrato de Bendamustina , Inmunoterapia Adoptiva , Depleción Linfocítica , Linfoma de Células B Grandes Difuso , Receptores de Antígenos de Linfocitos T , Clorhidrato de Bendamustina/efectos adversos , Clorhidrato de Bendamustina/uso terapéutico , Ciclofosfamida/uso terapéutico , Síndrome de Liberación de Citoquinas/tratamiento farmacológico , Humanos , Inmunoterapia Adoptiva/métodos , Depleción Linfocítica/métodos , Linfoma de Células B Grandes Difuso/terapia , Receptores de Antígenos de Linfocitos T/uso terapéutico
2.
Phys Rev Lett ; 121(5): 051101, 2018 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-30118264

RESUMEN

We present the precision measurement from May 2011 to May 2017 (79 Bartels rotations) of the proton fluxes at rigidities from 1 to 60 GV and the helium fluxes from 1.9 to 60 GV based on a total of 1×10^{9} events collected with the Alpha Magnetic Spectrometer aboard the International Space Station. This measurement is in solar cycle 24, which has the solar maximum in April 2014. We observed that, below 40 GV, the proton flux and the helium flux show nearly identical fine structures in both time and relative amplitude. The amplitudes of the flux structures decrease with increasing rigidity and vanish above 40 GV. The amplitudes of the structures are reduced during the time period, which started one year after solar maximum, when the proton and helium fluxes steadily increase. Above ∼3 GV the p/He flux ratio is time independent. We observed that below ∼3 GV the ratio has a long-term decrease coinciding with the period during which the fluxes start to rise.

3.
Phys Rev Lett ; 121(5): 051103, 2018 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-30118280

RESUMEN

A precision measurement of the nitrogen flux with rigidity (momentum per unit charge) from 2.2 GV to 3.3 TV based on 2.2×10^{6} events is presented. The detailed rigidity dependence of the nitrogen flux spectral index is presented for the first time. The spectral index rapidly hardens at high rigidities and becomes identical to the spectral indices of primary He, C, and O cosmic rays above ∼700 GV. We observed that the nitrogen flux Φ_{N} can be presented as the sum of its primary component Φ_{N}^{P} and secondary component Φ_{N}^{S}, Φ_{N}=Φ_{N}^{P}+Φ_{N}^{S}, and we found Φ_{N} is well described by the weighted sum of the oxygen flux Φ_{O} (primary cosmic rays) and the boron flux Φ_{B} (secondary cosmic rays), with Φ_{N}^{P}=(0.090±0.002)×Φ_{O} and Φ_{N}^{S}=(0.62±0.02)×Φ_{B} over the entire rigidity range. This corresponds to a change of the contribution of the secondary cosmic ray component in the nitrogen flux from 70% at a few GV to <30% above 1 TV.

4.
Phys Rev Lett ; 121(5): 051102, 2018 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-30118287

RESUMEN

We present high-statistics, precision measurements of the detailed time and energy dependence of the primary cosmic-ray electron flux and positron flux over 79 Bartels rotations from May 2011 to May 2017 in the energy range from 1 to 50 GeV. For the first time, the charge-sign dependent modulation during solar maximum has been investigated in detail by leptons alone. Based on 23.5×10^{6} events, we report the observation of short-term structures on the timescale of months coincident in both the electron flux and the positron flux. These structures are not visible in the e^{+}/e^{-} flux ratio. The precision measurements across the solar polarity reversal show that the ratio exhibits a smooth transition over 830±30 days from one value to another. The midpoint of the transition shows an energy dependent delay relative to the reversal and changes by 260±30 days from 1 to 6 GeV.

5.
Phys Rev Lett ; 120(2): 021101, 2018 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-29376729

RESUMEN

We report on the observation of new properties of secondary cosmic rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of 5.4×10^{6} nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of 2.0±0.1. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary cosmic rays has also been observed in the AMS measurement of primary cosmic rays He, C, and O but the rigidity dependences of primary cosmic rays and of secondary cosmic rays are distinctly different. In particular, above 200 GV, the secondary cosmic rays harden more than the primary cosmic rays.

6.
Phys Rev Lett ; 119(25): 251101, 2017 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-29303302

RESUMEN

We report the observation of new properties of primary cosmic rays He, C, and O measured in the rigidity (momentum/charge) range 2 GV to 3 TV with 90×10^{6} helium, 8.4×10^{6} carbon, and 7.0×10^{6} oxygen nuclei collected by the Alpha Magnetic Spectrometer (AMS) during the first five years of operation. Above 60 GV, these three spectra have identical rigidity dependence. They all deviate from a single power law above 200 GV and harden in an identical way.

7.
Phys Rev Lett ; 117(9): 091103, 2016 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-27610839

RESUMEN

A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49×10^{5} antiproton events and 2.42×10^{9} proton events. The fluxes and flux ratios of charged elementary particles in cosmic rays are also presented. In the absolute rigidity range ∼60 to ∼500 GV, the antiproton p[over ¯], proton p, and positron e^{+} fluxes are found to have nearly identical rigidity dependence and the electron e^{-} flux exhibits a different rigidity dependence. Below 60 GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios each reaches a maximum. From ∼60 to ∼500 GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.

8.
Phys Rev Lett ; 117(23): 231102, 2016 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-27982618

RESUMEN

Knowledge of the rigidity dependence of the boron to carbon flux ratio (B/C) is important in understanding the propagation of cosmic rays. The precise measurement of the B/C ratio from 1.9 GV to 2.6 TV, based on 2.3 million boron and 8.3 million carbon nuclei collected by AMS during the first 5 years of operation, is presented. The detailed variation with rigidity of the B/C spectral index is reported for the first time. The B/C ratio does not show any significant structures in contrast to many cosmic ray models that require such structures at high rigidities. Remarkably, above 65 GV, the B/C ratio is well described by a single power law R^{Δ} with index Δ=-0.333±0.014(fit)±0.005(syst), in good agreement with the Kolmogorov theory of turbulence which predicts Δ=-1/3 asymptotically.

9.
Phys Rev Lett ; 114(17): 171103, 2015 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-25978222

RESUMEN

A precise measurement of the proton flux in primary cosmic rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge of the rigidity dependence of the proton flux is important in understanding the origin, acceleration, and propagation of cosmic rays. We present the detailed variation with rigidity of the flux spectral index for the first time. The spectral index progressively hardens at high rigidities.

10.
Phys Rev Lett ; 115(21): 211101, 2015 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-26636836

RESUMEN

Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.

11.
Phys Rev Lett ; 113(12): 121102, 2014 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-25279617

RESUMEN

Precision measurements by the Alpha Magnetic Spectrometer on the International Space Station of the primary cosmic-ray electron flux in the range 0.5 to 700 GeV and the positron flux in the range 0.5 to 500 GeV are presented. The electron flux and the positron flux each require a description beyond a single power-law spectrum. Both the electron flux and the positron flux change their behavior at ∼30 GeV but the fluxes are significantly different in their magnitude and energy dependence. Between 20 and 200 GeV the positron spectral index is significantly harder than the electron spectral index. The determination of the differing behavior of the spectral indices versus energy is a new observation and provides important information on the origins of cosmic-ray electrons and positrons.

12.
Phys Rev Lett ; 113(22): 221102, 2014 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-25494065

RESUMEN

We present a measurement of the cosmic ray (e^{+}+e^{-}) flux in the range 0.5 GeV to 1 TeV based on the analysis of 10.6 million (e^{+}+e^{-}) events collected by AMS. The statistics and the resolution of AMS provide a precision measurement of the flux. The flux is smooth and reveals new and distinct information. Above 30.2 GeV, the flux can be described by a single power law with a spectral index γ=-3.170±0.008(stat+syst)±0.008(energy scale).

13.
Neuron ; 31(5): 773-89, 2001 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-11567616

RESUMEN

Within the developing vertebrate nervous system, the mechanisms that coordinate neuronal subtype identity with generic features of neuronal differentiation are poorly defined. We show here that a bHLH protein, Olig2, is expressed selectively by motor neuron progenitors and has a key role in specifying the subtype identity and pan-neuronal properties of developing motor neurons. The role of Olig2 in the specification of motor neuron subtype identity depends on regulatory interactions with progenitor homeodomain proteins, whereas its role in promoting pan-neuronal properties is associated with expression of another bHLH protein, Ngn2. Both aspects of Olig2 function appear to depend on its activity as a transcriptional repressor. Together, these studies show that Olig2 has a critical role in integrating diverse features of motor neuron differentiation in the developing spinal cord.


Asunto(s)
Diferenciación Celular/fisiología , Sistema Nervioso Central/embriología , Secuencias Hélice-Asa-Hélice/genética , Neuronas Motoras/citología , Proteínas del Tejido Nervioso/genética , Proteínas Represoras/genética , Células Madre/citología , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Tipificación del Cuerpo/genética , Ciclo Celular/fisiología , Sistema Nervioso Central/citología , Sistema Nervioso Central/metabolismo , Embrión de Pollo , Feto , Regulación del Desarrollo de la Expresión Génica/fisiología , Proteínas de Homeodominio/genética , Inmunohistoquímica , Hibridación in Situ , Ratones , Datos de Secuencia Molecular , Neuronas Motoras/metabolismo , Factor de Transcripción 2 de los Oligodendrocitos , Estructura Terciaria de Proteína/genética , Células Madre/metabolismo , Factores de Transcripción/fisiología , Transcripción Genética/fisiología
14.
Technology (Singap World Sci) ; 6(2): 59-66, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30057935

RESUMEN

Diagnostic blood testing is the most commonly performed clinical procedure in the world, and influences the majority of medical decisions made in hospital and laboratory settings. However, manual blood draw success rates are dependent on clinician skill and patient physiology, and results are generated almost exclusively in centralized labs from large-volume samples using labor-intensive analytical techniques. This paper presents a medical device that enables end-to-end blood testing by performing blood draws and providing diagnostic results in a fully automated fashion at the point-of-care. The system couples an image-guided venipuncture robot, developed to address the challenges of routine venous access, with a centrifuge-based blood analyzer to obtain quantitative measurements of hematology. We first demonstrate a white blood cell assay on the analyzer, using a blood mimicking fluid spiked with fluorescent microbeads, where the area of the packed bead layer is correlated with the bead concentration. Next we perform experiments to evaluate the pumping efficiency of the sample handling module. Finally, studies are conducted on the integrated device - from blood draw to analysis - using blood vessel phantoms to assess the accuracy and repeatability of the resulting white blood cell assay.

15.
Genes Brain Behav ; 17(6): e12466, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29446202

RESUMEN

Inhibitory interneurons mediate the gating of synaptic transmission and modulate the activities of neural circuits. Disruption of the function of inhibitory networks in the forebrain is linked to impairment of social and cognitive behaviors, but the involvement of inhibitory interneurons in the cerebellum has not been assessed. We found that Cadherin 13 (Cdh13), a gene implicated in autism spectrum disorder and attention-deficit hyperactivity disorder, is specifically expressed in Golgi cells within the cerebellar cortex. To assess the function of Cdh13 and utilize the manipulation of Cdh13 expression in Golgi cells as an entry point to examine cerebellar-mediated function, we generated mice carrying Cdh13-floxed alleles and conditionally deleted Cdh13 with GlyT2::Cre mice. Loss of Cdh13 results in a decrease in the expression/localization of GAD67 and reduces spontaneous inhibitory postsynaptic current (IPSC) in cerebellar Golgi cells without disrupting spontaneous excitatory postsynaptic current (EPSC). At the behavioral level, loss of Cdh13 in the cerebellum, piriform cortex and endopiriform claustrum have no impact on gross motor coordination or general locomotor behaviors, but leads to deficits in cognitive and social abilities. Mice lacking Cdh13 exhibit reduced cognitive flexibility and loss of preference for contact region concomitant with increased reciprocal social interactions. Together, our findings show that Cdh13 is critical for inhibitory function of Golgi cells, and that GlyT2::Cre-mediated deletion of Cdh13 in non-executive centers of the brain, such as the cerebellum, may contribute to cognitive and social behavioral deficits linked to neurological disorders.


Asunto(s)
Cadherinas/deficiencia , Cerebelo/fisiología , Cognición/fisiología , Aparato de Golgi/fisiología , Animales , Cadherinas/genética , Cadherinas/metabolismo , Cerebelo/metabolismo , Femenino , Neuronas GABAérgicas/metabolismo , Perfilación de la Expresión Génica , Aparato de Golgi/genética , Aparato de Golgi/metabolismo , Interneuronas/metabolismo , Masculino , Ratones , Conducta Social , Transmisión Sináptica , Ácido gamma-Aminobutírico/metabolismo
16.
Bone Marrow Transplant ; 51(1): 58-66, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26437062

RESUMEN

Grade 3 follicular lymphoma (FL) has aggressive clinical behavior. To evaluate the optimal first transplantation approach in relapsed/refractory grade 3 FL patients, we compared the long-term outcomes after allogeneic (allo-) vs autologous hematopoietic cell transplantation (auto-HCT) in the rituximab era. A total of 197 patients undergoing first reduced-intensity conditioning (RIC) allo-HCT or first auto-HCT during 2000-2012 were included. Rituximab-naive patients were excluded. Allo-HCT recipients were younger, more heavily pretreated and had a longer interval between diagnosis and HCT. The 5-year probabilities of non-relapse mortality (NRM), relapse/progression, PFS and overall survival (OS) for auto-HCT vs allo-HCT groups were 4% vs 27% (P<0.001), 61% vs 20% (P<0.001), 36% vs 51% (P=0.07) and 59% vs 54% (P=0.7), respectively. On multivariate analysis, auto-HCT was associated with reduced risk of NRM (relative risk (RR)=0.20; P=0.001). Within the first 11 months post HCT, auto- and allo-HCT had similar risks of relapse/progression and PFS. Beyond 11 months, auto-HCT was associated with higher risk of relapse/progression (RR=21.3; P=0.003) and inferior PFS (RR=3.2; P=0.005). In the first 24 months post HCT, auto-HCT was associated with improved OS (RR=0.42; P=0.005), but in long-time survivors (beyond 24 months) it was associated with inferior OS (RR=3.6; P=0.04). RIC allo-HCT as the first transplant approach can provide improved PFS and OS, in long-term survivors.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Linfoma Folicular/mortalidad , Linfoma Folicular/terapia , Adulto , Anciano , Aloinjertos , Autoinjertos , Supervivencia sin Enfermedad , Femenino , Humanos , Linfoma Folicular/patología , Masculino , Persona de Mediana Edad , Tasa de Supervivencia , Factores de Tiempo
17.
Leukemia ; 29(7): 1578-86, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25708834

RESUMEN

Antibody drug conjugates (ADCs), in which cytotoxic drugs are linked to antibodies targeting antigens on tumor cells, represent promising novel agents for the treatment of malignant lymphomas. Pinatuzumab vedotin is an anti-CD22 ADC and polatuzumab vedotin an anti-CD79B ADC that are both linked to the microtubule-disrupting agent monomethyl auristatin E (MMAE). In the present study, we analyzed the activity of these agents in different molecular subtypes of diffuse large B-cell lymphoma (DLBCL) both in vitro and in early clinical trials. Both anti-CD22-MMAE and anti-CD79B-MMAE were highly active and induced cell death in the vast majority of activated B-cell-like (ABC) and germinal center B-cell-like (GCB) DLBCL cell lines. Similarly, both agents induced cytotoxicity in models with and without mutations in the signaling molecule CD79B. In line with these observations, relapsed and refractory DLBCL patients of both subtypes responded to these agents. Importantly, a strong correlation between CD22 and CD79B expression in vitro and in vivo was not detectable, indicating that patients should not be excluded from anti-CD22-MMAE or anti-CD79B-MMAE treatment because of low target expression. In summary, these studies suggest that pinatuzumab vedotin and polatuzumab vedotin are active agents for the treatment of patients with different subtypes of DLBCL.


Asunto(s)
Anticuerpos Monoclonales/farmacología , Antígenos CD79/inmunología , Inmunoconjugados/farmacología , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/inmunología , Lectina 2 Similar a Ig de Unión al Ácido Siálico/inmunología , Apoptosis/efectos de los fármacos , Western Blotting , Antígenos CD79/genética , Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Ensayos Clínicos Fase I como Asunto , Estudios de Cohortes , Citometría de Flujo , Estudios de Seguimiento , Humanos , Técnicas para Inmunoenzimas , Linfoma de Células B Grandes Difuso/clasificación , Linfoma de Células B Grandes Difuso/patología , Mutación/genética , Estadificación de Neoplasias , Pronóstico , Lectina 2 Similar a Ig de Unión al Ácido Siálico/genética , Células Tumorales Cultivadas
18.
Bone Marrow Transplant ; 50(11): 1416-23, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26237164

RESUMEN

Autologous hematopoietic cell transplantation (AutoHCT) is a potentially curative treatment modality for relapsed/refractory Hodgkin lymphoma (HL). However, no large studies have evaluated pretransplant factors predictive of outcomes of AutoHCT in children, adolescents and young adults (CAYA, age <30 years). In a retrospective study, we analyzed 606 CAYA patients (median age 23 years) with relapsed/refractory HL who underwent AutoHCT between 1995 and 2010. The probabilities of PFS at 1, 5 and 10 years were 66% (95% confidence interval (CI): 62-70), 52% (95% CI: 48-57) and 47% (95% CI: 42-51), respectively. Multivariate analysis for PFS demonstrated that at the time of AutoHCT patients with Karnofsky/Lansky score ⩾90, no extranodal involvement and chemosensitive disease had significantly improved PFS. Patients with time from diagnosis to first relapse of <1 year had a significantly inferior PFS. A prognostic model for PFS was developed that stratified patients into low-, intermediate- and high-risk groups, predicting for 5-year PFS probabilities of 72% (95% CI: 64-80), 53% (95% CI: 47-59) and 23% (95% CI: 9-36), respectively. This large study identifies a group of CAYA patients with relapsed/refractory HL who are at high risk of progression after AutoHCT. Such patients should be targeted for novel therapeutic and/or maintenance approaches post-AutoHCT.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Enfermedad de Hodgkin/terapia , Modelos Teóricos , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Causas de Muerte , Niño , Preescolar , Terapia Combinada , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Enfermedad de Hodgkin/tratamiento farmacológico , Enfermedad de Hodgkin/mortalidad , Enfermedad de Hodgkin/radioterapia , Humanos , Masculino , Neoplasias Primarias Secundarias/epidemiología , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Terapia Recuperativa , Trasplante Autólogo , Adulto Joven
19.
Endocrinology ; 124(5): 2252-60, 1989 May.
Artículo en Inglés | MEDLINE | ID: mdl-2539974

RESUMEN

The internalization of [125I]secretin in pancreatic acinar cells was evaluated by differentiation of surface-bound and internalized radioligand with an acidified glycine buffer. The amount of surface-bound radioligand was 2-fold higher at 37 C than at 4 C between 15 and 60 min; internalized radioactivity was more than 10-fold greater at 37 C than at 4 C during the same time period. The effects of chloroquine, dithiothreitol (DTT), carbonyl cyanide m-chlorophenyl-hydrazone (CCCP), and dansylcadaverine on the binding and internalization of secretin were then evaluated. Chloroquine (0.1 mM), a lysosomotropic agent, did not affect secretin radioligand binding to its pancreatic receptor, while DTT, a sulfhydryl reducing agent, significantly lowered binding by more than 90% from 15-60 min. The metabolic inhibitor CCCP, however, significantly enhanced binding of the secretin radioligand in both the surface and the internalized pools. Surface binding was 1.6- to 3.3-fold greater from 15-60 min (P less than or equal to 0.01) in acinar cells exposed to CCCP than in untreated controls, while internalized radioactivity increased from 2.8- to 1.4-fold above the control value (P less than or equal to 0.01) at the same times. Dansylcadaverine, an inhibitor of receptor recycling, reduced internalized radioligand by 40% after 30 min of binding. The effects of these chemical agents on cAMP production were also considered. cAMP production was significantly reduced by DTT, CCCP, and dansylcadaverine at secretin concentrations of 0.1, 3.0, and 10 nM, respectively. This study demonstrates that 1) pancreatic acinar cells rapidly internalize [125I]secretin; 2) internalization of secretin does not enhance cAMP production; and 3) disulfide linkages are important for secretin receptor activity.


Asunto(s)
Adenosina Monofosfato/metabolismo , Páncreas/metabolismo , Secretina/metabolismo , Animales , Bacitracina/farmacología , Cadaverina/análogos & derivados , Cadaverina/farmacología , Carbonil Cianuro m-Clorofenil Hidrazona/farmacología , Membrana Celular/metabolismo , Cloroquina/farmacología , AMP Cíclico/metabolismo , Ditiotreitol/farmacología , Páncreas/citología , Receptores Acoplados a Proteínas G , Receptores de la Hormona Gastrointestinal/metabolismo
20.
Bone Marrow Transplant ; 47(12): 1526-9, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22562080

RESUMEN

Plerixafor augments PBSC collection, but the optimal approach for incorporating it into mobilization is uncertain. Forty-nine consecutive patients mobilized with G-CSF alone were analyzed, and a day 4 peripheral blood CD34(+) cell count of 0.015/ml was found to predict for a day 5 apheresis yield of 2 × 10(6) CD34(+) progenitors/kg, our institutional minimum necessary for a single autologous transplant. On the basis of this relationship, a clinical guideline was developed which recommended pre-emptive use of plerixafor if the day 4 peripheral blood CD34(+) cell count was between 0.005 and 0.015/ml. A total of 166 consecutive subjects with lymphoma or plasma cell dyscrasias underwent G-CSF mobilization after adoption of this care pathway, and the mobilization failure rate was only 7% in patients managed per guideline. The median PBSC yield was 6.3 × 10(6) CD34(+) progenitors/kg with G-CSF (day 4 peripheral blood CD34(+) cell > 0.015/ml) and 4.9 × 10(6) CD34(+) progenitors/kg with G-CSF+plerixafor (day 4 peripheral blood CD34(+) cell 0.005-0.015/ml). The median number of days of apheresis was 2 in both groups. This clinical guideline is an effective mobilization algorithm that minimizes mobilization failures, reduces poor apheresis yields, does not require risk factor identification and is simple to implement.


Asunto(s)
Algoritmos , Movilización de Célula Madre Hematopoyética/métodos , Compuestos Heterocíclicos/administración & dosificación , Adulto , Anciano , Bencilaminas , Ciclamas , Femenino , Factor Estimulante de Colonias de Granulocitos/administración & dosificación , Humanos , Linfoma/sangre , Linfoma/terapia , Masculino , Persona de Mediana Edad , Paraproteinemias/sangre , Paraproteinemias/terapia , Trasplante Autólogo , Resultado del Tratamiento
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA