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1.
Chemistry ; 30(6): e202302267, 2024 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-37779321

RESUMEN

The control of molecular motions is a central topic of molecular machine research. Molecular brakes are fundamental building blocks towards such goal as they allow deliberately decelerating specific motions after an outside stimulus is applied. Here we present azotriptycenes as structural framework for light-controlled molecular brakes. The intrinsic kinetics and their changes upon azotriptycene isomerization are scrutinized comprehensively by a mixed theoretical and variable temperature NMR approach. With azotriptycenes C-N bond rotation rates can be decelerated or accelerated reversibly by up to five orders of magnitude. Rate change effects are highly localized and are strongest for the C-N bond connecting a triptycene rotor fragment to the central diazo group. The detailed mechanistic insights provide a solid basis for further conscious design and applications in the future.

2.
Proc Natl Acad Sci U S A ; 118(44)2021 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-34716271

RESUMEN

Plants and animals use cell surface receptors to sense and interpret environmental signals. In legume symbiosis with nitrogen-fixing bacteria, the specific recognition of bacterial lipochitooligosaccharide (LCO) signals by single-pass transmembrane receptor kinases determines compatibility. Here, we determine the structural basis for LCO perception from the crystal structures of two lysin motif receptor ectodomains and identify a hydrophobic patch in the binding site essential for LCO recognition and symbiotic function. We show that the receptor monitors the composition of the amphiphilic LCO molecules and uses kinetic proofreading to control receptor activation and signaling specificity. We demonstrate engineering of the LCO binding site to fine-tune ligand selectivity and correct binding kinetics required for activation of symbiotic signaling in plants. Finally, the hydrophobic patch is found to be a conserved structural signature in this class of LCO receptors across legumes that can be used for in silico predictions. Our results provide insights into the mechanism of cell-surface receptor activation by kinetic proofreading of ligands and highlight the potential in receptor engineering to capture benefits in plant-microbe interactions.


Asunto(s)
Fabaceae/genética , Lipopolisacáridos/metabolismo , Simbiosis/fisiología , Fabaceae/metabolismo , Expresión Génica/genética , Regulación de la Expresión Génica de las Plantas/genética , Cinética , Lipopolisacáridos/genética , Micorrizas/fisiología , Proteínas de Plantas/genética , Plantas/metabolismo , Rhizobium/fisiología , Transducción de Señal , Simbiosis/genética
3.
Angew Chem Int Ed Engl ; 61(19): e202201882, 2022 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-35146857

RESUMEN

Molecular motors transform external energy input into directional motions and offer exquisite precision for nano-scale manipulations. To make full use of molecular motor capacities, their directional motions need to be transmitted and used for powering downstream molecular events. Here we present a macrocyclic molecular motor structure able to perform repetitive molecular threading of a flexible tetraethylene glycol chain through the macrocycle. This mechanical threading event is actively powered by the motor and leads to a direct translation of the unidirectional motor rotation into unidirectional translation motion (chain versus ring). The mechanism of the active mechanical threading is elucidated and the actual threading step is identified as a combined helix inversion and threading event. The established molecular machine function resembles the crucial step of macroscopic weaving or sewing processes and therefore offers a first entry point to a "molecular knitting" counterpart.


Asunto(s)
Termodinámica , Rotación
4.
Chemistry ; 27(41): 10758-10765, 2021 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-33945652

RESUMEN

Tuning the thermal behavior of light driven molecular motors is fundamentally important for their future rational design. In many molecular motors thermal ratcheting steps are comprised of helicity inversions, energetically stabilizing the initial photoproducts. In this work we investigated a series of five hemithioindigo (HTI) based molecular motors to reveal the influence of steric hindrance in close proximity to the rotation axle on this process. Applying a high yielding synthetic procedure, we synthesized constitutional isomeric derivatives to distinguish between substitution effects at the aromatic and aliphatic position on the rotor fragment. The kinetics of thermal helix inversions were elucidated using low temperature 1 H NMR spectroscopy and an in situ irradiation technique. In combination with a detailed theoretical description, a comparative analysis of substituent effects on the thermal helix inversions of the rotation cycle is now possible. Such deeper understanding of the rotational cycle of HTI molecular motors is essential for speed regulation and future applications of visible light triggered nanomachines.


Asunto(s)
Carmin de Índigo , Carmin de Índigo/análogos & derivados , Isomerismo , Fotoquímica , Rotación
5.
J Am Chem Soc ; 141(32): 12570-12581, 2019 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-31251878

RESUMEN

Two-dimensional covalent organic frameworks (2D COFs) attract great interest owing to their well-defined pore structure, thermal stability, high surface area, and permanent porosity. In combination with a tunable chemical pore environment, COFs are intriguing candidates for molecular sieving based on selective host-guest interactions. Herein, we report on 2D COF structures capable of reversibly switching between a highly correlated crystalline, porous and a poorly correlated, nonporous state by exposure to external stimuli. To identify COF structures with such dynamic response, we systematically studied the structural properties of a family of two-dimensional imine COFs comprising tris(4-aminophenyl)benzene (TAPB) and a variety of dialdehyde linear building blocks including terephthalaldehyde (TA) and dialdehydes of thienothiophene (TT), benzodithiophene (BDT), dimethoxybenzodithiophene (BDT-OMe), diethoxybenzodithiophene (BDT-OEt), dipropoxybenzodithiophene (BDT-OPr), and pyrene (Pyrene-2,7). TAPB-COFs consisting of linear building blocks with enlarged π-systems or alkoxy functionalities showed significant stability toward exposure to external stimuli such as solvents or solvent vapors. In contrast, TAPB-COFs containing unsubstituted linear building blocks instantly responded to exposure to these external stimuli by a drastic reduction in COF layer correlation, long-range order, and porosity. To reverse the process we developed an activation procedure in supercritical carbon dioxide (scCO2) as a highly efficient means to revert fragile nonporous and amorphous COF polymers into highly crystalline and open porous frameworks. Strikingly, the framework structure of TAPB-COFs responds dynamically to such chemical stimuli, demonstrating that their porosity and crystallinity can be reversibly controlled by alternating steps of solvent stimuli and scCO2 activation.

6.
Ann Oncol ; 29(8): 1658-1686, 2018 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-30113631

RESUMEN

The European Society for Medical Oncology (ESMO) consensus conference on testicular cancer was held on 3-5 November 2016 in Paris, France. The conference included a multidisciplinary panel of 36 leading experts in the diagnosis and treatment of testicular cancer (34 panel members attended the conference; an additional two panel members [CB and K-PD] participated in all preparatory work and subsequent manuscript development). The aim of the conference was to develop detailed recommendations on topics relating to testicular cancer that are not covered in detail in the current ESMO Clinical Practice Guidelines (CPGs) and where the available level of evidence is insufficient. The main topics identified for discussion related to: (1) diagnostic work-up and patient assessment; (2) stage I disease; (3) stage II-III disease; (4) post-chemotherapy surgery, salvage chemotherapy, salvage and desperation surgery and special topics; and (5) survivorship and follow-up schemes. The experts addressed questions relating to one of the five topics within five working groups. Relevant scientific literature was reviewed in advance. Recommendations were developed by the working groups and then presented to the entire panel. A consensus vote was obtained following whole-panel discussions, and the consensus recommendations were then further developed in post-meeting discussions in written form. This manuscript presents the results of the expert panel discussions, including the consensus recommendations and a summary of evidence supporting each recommendation. All participants approved the final manuscript.


Asunto(s)
Oncología Médica/normas , Recurrencia Local de Neoplasia/prevención & control , Neoplasias de Células Germinales y Embrionarias/terapia , Guías de Práctica Clínica como Asunto , Neoplasias Testiculares/terapia , Cuidados Posteriores/métodos , Cuidados Posteriores/normas , Supervivientes de Cáncer/psicología , Quimioradioterapia Adyuvante/métodos , Quimioradioterapia Adyuvante/normas , Conferencias de Consenso como Asunto , Europa (Continente) , Humanos , Masculino , Oncología Médica/métodos , Terapia Neoadyuvante/métodos , Terapia Neoadyuvante/normas , Recurrencia Local de Neoplasia/epidemiología , Estadificación de Neoplasias , Neoplasias de Células Germinales y Embrionarias/diagnóstico , Neoplasias de Células Germinales y Embrionarias/patología , Orquiectomía/psicología , Cuidados Paliativos/métodos , Cuidados Paliativos/normas , Pronóstico , Calidad de Vida , Factores de Riesgo , Terapia Recuperativa/métodos , Terapia Recuperativa/normas , Sociedades Médicas/normas , Supervivencia , Neoplasias Testiculares/diagnóstico , Neoplasias Testiculares/patología , Testículo/diagnóstico por imagen , Testículo/patología , Testículo/cirugía
7.
Ann Oncol ; 28(6): 1346-1351, 2017 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-28383677

RESUMEN

Background: Therapeutic options for patients with chemoresistant germ cell tumors (GCTs) are limited. Pazopanib is a selective tyrosine kinase inhibitor with distinct antiangiogenic activity. We aimed to evaluate pazopanib activity in patients with refractory GCT. Patients and methods: In the open-label, single-arm, phase 2 Pazotest study (NCT01743482), patient eligibility included failure of ≥2 platinum-based regimens, and allowed prior high-dose chemotherapy administration. Patients were given pazopanib 800 mg/day until disease progression (PD) or onset of unacceptable toxicity. Measurements of serum tumor markers (STM), computed tomography and FDG-PET were carried out at baseline, after 4 weeks of pazopanib treatment, and every 8 weeks thereafter. PD was defined as increasing levels of STM, increasing size of non-teratomatous masses, or appearance of new lesions. The study primary endpoint was progression-free survival (PFS, H0: 3-month PFS ≤ 10%, H1: ≥25%, α = 5%, ß = 20%). Results: Forty-three patients were enrolled from May 2013 to July 2016. The number of prior chemotherapy regimens was: 2 (11.6%), 3 (51.2%), >3 (37.2%). Grade 3 adverse events were observed in six patients (13.9%). Overall, 70.3% of patients had reduced levels of STM after 4 weeks. There were 2 partial responses (4.7%), 19 cases of stable disease, and 16 cases of PD (6 not evaluable by RECIST). The median follow-up duration was 29.6 months. The 3-month PFS probability was 12.8% [95% confidence interval (CI): 5.7%-28.9%]. The 24-month OS probability was 14.2% (95% CI: 6.0%-33.7%). In patients with a >50% decline in STM, the 24-month OS probability was 24.1% (95% CI: 8.3%-69.6%). The small sample size was the major limitation. Conclusions: Despite pazopanib showed potent but short-lived activity in refractory GCT, long-term survival was obtained in a proportion of treated patients. According to the kinetics of pazopanib activity, this drug may be investigated in less pre-treated patients as an optimal bridging therapy preceding and/or combined with salvage chemotherapy.


Asunto(s)
Inhibidores de la Angiogénesis/uso terapéutico , Neoplasias de Células Germinales y Embrionarias/tratamiento farmacológico , Pirimidinas/uso terapéutico , Sulfonamidas/uso terapéutico , Neoplasias Testiculares/tratamiento farmacológico , Adulto , Progresión de la Enfermedad , Humanos , Indazoles , Masculino , Resultado del Tratamiento
8.
Ann Oncol ; 26(4): 657-668, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25214543

RESUMEN

BACKGROUND: Outcomes of radiotherapy (RT) compared with chemotherapy (CT) remain poorly defined for clinical stage (CS) IIA and IIB seminoma. We aimed to evaluate the current role of the two treatment modalities in this setting of testicular seminoma. PATIENTS AND METHODS: A systematic review and meta-analysis (MA) was carried out to identify all evaluable studies. Search was limited to studies published after 1990 and included the Medline, Embase databases, and abstracts from ASCO (GU), ESMO, AUA, and ASTRO meetings up to April 2014. Sensitivity analyses were applied including the following: CSIIA and CSIIB, paraortic + iliac RT only in both stages, RT dose (≥30 versus <30 Gy), and PEB/EP regimens only. RESULTS: Thirteen studies have been selected for MA on relapse outcome. No randomized trials compared RT and CT. There were 4 prospective and 9 retrospective studies, with a total of 607 patients receiving RT and 283 patients CT. The pooled relapse rate (RR) was similar between the RT [0.11, 95% confidence interval (CI) 0.08-0.14, P for heterogeneity = 0.096, I(2) = 38%] and CT groups (0.08, 95% CI 0.01-0.15, P for heterogeneity <0.001, I(2) = 82.5%). However, in the sensitivity analysis, the pooled RR for RT in CSIIB was 0.12 (95% CI 0.06-0.17) while it was 0.05 (95% CI 0-0.11) for CT. Long-term side-effects and incidence of second cancers were more frequently reported following RT. The overall incidence of nontesticular second malignancies was 0.04 (95% CI 0.01-0.02) in the RT group and 0.02 (95% CI 0.003-0.04) in the CT group. CONCLUSIONS: Although RT and CT appeared to be equal options in CSIIA and IIB seminoma, a trend in favor of CT for a lower incidence of side-effects and RR in CSIIB was found. This evidence is limited by the retrospective quality of studies and their small sample size.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Radioterapia , Seminoma/tratamiento farmacológico , Seminoma/radioterapia , Neoplasias Testiculares/tratamiento farmacológico , Neoplasias Testiculares/radioterapia , Humanos , Masculino , Estadificación de Neoplasias , Pronóstico , Seminoma/patología , Neoplasias Testiculares/patología
9.
Ann Oncol ; 26(1): 167-172, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25344361

RESUMEN

BACKGROUND: In the late 1990s, the use of high-dose chemotherapy (HDCT) and stem-cell rescue held promise for patients with advanced and poor prognosis germ-cell tumors (GCT). We started a randomized phase II trial to assess the efficacy of sequential HDCT compared with cisplatin, etoposide, and bleomycin (PEB). PATIENTS AND METHODS: Patients were randomly assigned to receive four cycles of PEB every 3 weeks or two cycles of PEB followed by a high-dose sequence (HDS) comprising HD-cyclophosphamide (7.0 g/m(2)), 2 courses of cisplatin and HD-etoposide (2.4 g/m(2)) with stem-cell support, and a single course of HD-carboplatin [area under the curve (AUC) 27 mg/ml × min] with autologous stem-cell transplant. Postchemotherapy surgery was planned on responding residual disease in both arms. The primary end point was progression-free survival (PFS). The study was designed to detect a 30% improvement of 5-year PFS (from 40% to 70%), with 80% power and two-sided α at 5%. RESULTS: From December 1996 to March 2007, 85 patients were randomized: 43 in PEB and 42 in HDS arm. Median follow-up was 114.2 months [interquartile range (IQR): 87.7-165.8]. Complete or partial response with normal markers (PRm-) were obtained in 28 (65.1%) and 29 (69.1%) patients, respectively. Five-year PFS was 55.8% [95% confidence interval (CI) 42.8-72.8] and 54.8% (95% CI 41.6%-72.1%) in PEB and HDS arm, respectively (log-rank test P = 0.726). Five-year overall survival was 62.8% (95% CI 49.9-79.0) and 59.3% (95% CI 46.1-76.3). One toxic death (PEB arm) was recorded. CONCLUSIONS: The study failed to meet the primary end point. Furthermore, survival estimates of conventional-dose chemotherapy higher than expected should be accounted for and will likely limit further improvements in the first-line setting. CLINICALTRIALS.GOV: NCT02161692.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Neoplasias de Células Germinales y Embrionarias/tratamiento farmacológico , Neoplasias Testiculares/tratamiento farmacológico , Adulto , Bleomicina/administración & dosificación , Carboplatino/administración & dosificación , Carboplatino/uso terapéutico , Cisplatino/administración & dosificación , Ciclofosfamida/administración & dosificación , Ciclofosfamida/uso terapéutico , Supervivencia sin Enfermedad , Combinación de Medicamentos , Etopósido/administración & dosificación , Femenino , Trasplante de Células Madre Hematopoyéticas , Humanos , Masculino , Neoplasias de Células Germinales y Embrionarias/mortalidad , Neoplasias Testiculares/mortalidad , Adulto Joven
10.
Br J Cancer ; 110(1): 26-33, 2014 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-24231947

RESUMEN

BACKGROUND: Pazopanib achieved the end point of clinical activity in pretreated patients with urothelial cancer in a single-group, phase 2 trial. The objective was to identify biological predictors of clinical benefit to pazopanib in these patients. METHODS: EDTA blood samples were collected at baseline (T0) and after 4 weeks (T1) of treatment, together with radiological imaging in all 41 patients to analyse plasma circulating angiogenic factor levels by multiplex ELISA plates. Changes from T0 to T1 in marker levels were matched with response with the covariance analysis. Univariable and multivariable analyses evaluated the association with overall survival (OS), adjusted for prespecified clinical variables. Net reclassification improvement (NRI) tested the performance of the recognised Cox model. RESULTS: Increasing IL8(T1) level associated with lower response probability at covariance analysis (P=0.010). Both IL8(T0) (P=0.019) and IL8(T1) (P=0.004) associated with OS and the prognostic model, including clinical variables and IL8(T1) best-predicted OS after backward selection. The NRI for this model was 39%.When analysed as a time-varying covariate, IL8(T1) level<80 pg ml(-1) portended significantly greater response (∼80%) and 6-month OS (∼60%) probability than level ≥ 80. CONCLUSION: IL8-level changes during pazopanib allowed for a prognostic improvement and were associated with response probability.


Asunto(s)
Inductores de la Angiogénesis/sangre , Citocinas/sangre , Interleucina-8/sangre , Pirimidinas/uso terapéutico , Sulfonamidas/uso terapéutico , Neoplasias Urológicas/sangre , Neoplasias Urológicas/tratamiento farmacológico , Inhibidores de la Angiogénesis/uso terapéutico , Biomarcadores de Tumor/sangre , Carcinoma de Células Transicionales/sangre , Carcinoma de Células Transicionales/tratamiento farmacológico , Ensayo de Inmunoadsorción Enzimática , Humanos , Indazoles , Imagen Multimodal , Tomografía de Emisión de Positrones , Pronóstico , Modelos de Riesgos Proporcionales , Tomografía Computarizada por Rayos X
11.
Chembiochem ; 15(14): 2097-105, 2014 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-25154732

RESUMEN

Recognition of carbohydrates by proteins is a ubiquitous biochemical process. In legume-rhizobium symbiosis, lipochitin oligosaccharides, also referred to as nodulation (nod) factors, function as primary rhizobial signal molecules to trigger root nodule development. Perception of these signal molecules is receptor mediated, and nod factor receptor 5 (NFR5) from the model legume Lotus japonicus is predicted to contain three LysM domain binding sites. Here we studied the interactions between nod factor and each of the three NFR5 LysM domains, which were chemically synthesized. LysM domain variants (up to 58 amino acids) designed to optimize solubility were chemically assembled by solid-phase peptide synthesis (SPPS) with microwave heating. Their interaction with nod factors and chitin oligosaccharides was studied by isothermal titration calorimetry and circular dichroism (CD) spectroscopy. LysM2 showed a change in folding upon nod factor binding, thus providing direct evidence that the LysM domain of NFR5 recognizes lipochitin oligosaccharides. These results clearly show that the L. japonicus LysM2 domain binds to the nod factor from Mesorhizobium loti, thereby causing a conformational change in the LysM2 domain. The preferential affinity for nod factors over chitin oligosaccharides was demonstrated by a newly developed glycan microarray. Besides the biological implications, our approach shows that carbohydrate binding to a small protein domain can be detected by CD spectroscopy.


Asunto(s)
Lipopolisacáridos/metabolismo , Lotus/microbiología , Proteínas de Plantas/metabolismo , Nodulación de la Raíz de la Planta , Rhizobium/fisiología , Simbiosis , Secuencia de Aminoácidos , Lotus/fisiología , Análisis por Micromatrices , Modelos Moleculares , Datos de Secuencia Molecular , Proteínas de Plantas/síntesis química , Proteínas de Plantas/química , Estructura Terciaria de Proteína , Técnicas de Síntesis en Fase Sólida
12.
Chembiochem ; 15(3): 425-34, 2014 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-24436194

RESUMEN

Glycan microarrays have emerged as novel tools to study carbohydrate-protein interactions. Here we describe the preparation of a covalent microarray with lipochitin oligosaccharides and its use in studying proteins containing LysM domains. The glycan microarray was assembled from glycoconjugates that were synthesized by using recently developed bifunctional chemoselective aminooxy reagents without the need for transient carbohydrate protecting groups. We describe for the first time the preparation of a covalent microarray with lipochitin oligosaccharides and its use for studying proteins containing LysM domains. Lipochitin oligosaccharides (also referred to as Nod factors) were isolated from bacterial strains or chemoenzymatically synthesized. The glycan microarray also included peptidoglycan-related compounds, as well as chitin oligosaccharides of different lengths. In total, 30 ligands were treated with the aminooxy linker molecule. The identity of the glycoconjugates was verified by mass spectrometry, and they were then immobilized on the array. The presence of the glycoconjugates on the array surface was confirmed by use of lectins and human sera (IgG binding). The functionality of our array was tested with a bacterial LysM domain-containing protein, autolysin p60, which is known to act on the bacterial cell wall peptidoglycan. P60 showed specific binding to Nod factors and to chitin oligosaccharides. Increasing affinity was observed with increasing chitin oligomer length.


Asunto(s)
Proteínas Bacterianas/metabolismo , Glicoconjugados/química , Lipopolisacáridos/química , Análisis por Micromatrices/métodos , N-Acetil Muramoil-L-Alanina Amidasa/metabolismo , Oximas/química , Proteínas Bacterianas/química , Glicoconjugados/metabolismo , Humanos , Inmunoglobulina G/inmunología , Lectinas/química , Lectinas/metabolismo , Ligandos , Lipopolisacáridos/aislamiento & purificación , Listeria monocytogenes/metabolismo , N-Acetil Muramoil-L-Alanina Amidasa/química , Péptidos/síntesis química , Péptidos/química , Peptidoglicano/química , Peptidoglicano/metabolismo , Unión Proteica
13.
Invest New Drugs ; 32(3): 555-60, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24566706

RESUMEN

Despite a compelling preclinical rationale for the use of anti-angiogenic drugs in urothelial cancer (UC), short-living responses have been observed in clinical trials. PF-03446962 is a novel monoclonal antibody against Activin Receptor-Like Kinase-1 (ALK1), a type I subclass of the TGFß receptor, with dose-dependent anti-angiogenic activity. An open label, single-group, phase 2 trial of PF-03446962 was conducted in salvage setting. Patients failing at least one chemotherapy regimen were eligible. Design provided PF-03446962 10 mg/Kg intravenously fortnightly until disease progression (PD) or unacceptable toxicity. Two-month progression-free survival (PFS) was the primary endpoint. The trial was registered with ClinicalTrials.gov, number NCT01620970. Fourteen patients were enrolled from October 2012 to July 2013. Median age was 64 years (interquartile range [IQR]: 58.2-69.5), 9 patients had a Bellmunt score of 1-2, median number of prior drugs was 3. One stable disease and 13 PD were recorded and the study met the futility stopping rule of interim analysis. Median PFS was 1.8 months (95 %CI, 1.4-2.0). After a median follow up of 7.4 months (IQR 4.5-10.9), 8 patients are alive. Median overall survival (OS) was 8 months (95 %CI, 2.9-not estimable). Most common toxicities were thrombocytopenia (G1-2 in 5 cases, persistent G3 in one, with 3 dose delays and 1 dose interruption), fatigue and abdominal pain (G1-2 in 4 cases each). Impairment of quality of life (ESAS score) was observed as well as an increase from baseline to +2 month median levels of vascular endothelial growth factor (VEGF) and interleukin-8. PF-03446962 had no activity as single drug in refractory UC and we do not recommend further investigation outside of the combination with agents targeting the VEGF receptor axis.


Asunto(s)
Receptores de Activinas Tipo II/antagonistas & inhibidores , Inhibidores de la Angiogénesis/uso terapéutico , Anticuerpos Monoclonales/uso terapéutico , Neoplasias Urológicas/tratamiento farmacológico , Receptores de Activinas Tipo II/inmunología , Anciano , Inhibidores de la Angiogénesis/efectos adversos , Anticuerpos Monoclonales/efectos adversos , Anticuerpos Monoclonales Humanizados , Femenino , Humanos , Masculino , Persona de Mediana Edad
14.
J Phys Condens Matter ; 36(32)2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38738500

RESUMEN

Analytical expressions for the low-field mobility of charge carrier gases with three-(3D), two-(2D) and one-(1D) dimensionalities are obtained. Multi-ion ionized impurities scattering, acoustic and polar optic phonons are considered as scattering mechanisms. The calculated values of mobility are compared to known experimental data for bulk (3D) n-and p-type wurtzite, n-type zinc-blende GaN crystals and low dimensional (2D and 1D) ternary GaAlN compounds. The resulting analytical expressions give the dependences of mobility on dimensionality of charge carrier gas, its density, effective mass, temperature and confining dimensions. A comparison of the experimental and calculated temperature dependences of the mobility in bulk GaN crystals (3D) and in AlGaN/GaN nanowires (1D) shows that the mobility atT>100Kis determined by the scattering of charge carriers by polar optical phonons with an energy of 91.2 meV. The temperature dependences of mobility in Al0.25Ga0.75N/GaN heterostructures (2D) atT>100Kare in consistent with experiment for electron scattering by polar optical phonons with a noticeably higher energy of 160 meV. We associate this fact with the heterointerface, which according to well-known theoretical studies can change both the strength of electron polar optical phonons scattering and the energy of the phonons.

15.
Ann Oncol ; 24(11): 2887-92, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23860612

RESUMEN

BACKGROUND: Since 1985, we introduced a modified combination of etoposide, ifosfamide, and cisplatin (PEI) as second-line therapy of adult male germ cell tumors with the aim to reduce toxic effect while maintaining efficacy over the original regimen. PATIENTS AND METHODS: Patients received four cycles of ifosfamide at 2.5 g/m(2) on days 1-2, etoposide, and cisplatin at 100 and 33 mg/m(2), respectively, on days 3-5 every 21 days, followed by surgery. Results were stratified according to the International Germ Cell Consensus Classification Group-2 (IGCCCG-2). RESULTS: From February 1985 to January 2012, 189 patients were treated. 72.6% were IGCCCG-2 intermediate-to-very high risk. Thirty-five patients (18.5%) had a complete response, 67 (35.4%) a marker normalization (PRm-). Median follow-up was 122.1 months (inter-quartile range [IQR]: 71.4-232.0). Two-year progression-free and 5-year overall survival were 34.3% [95% confidence interval (CI) 28.1% to 41.9%] and 42.1% (95% CI 35.3% to 50.2%), respectively. Survival estimates compared favorably with those obtained by conventional dose chemotherapy (CDCT) regimens in each prognostic category. 70.4% of grade 3-4 neutropenia (25.5% febrile neutropenia), 48.1% thrombocytopenia, 21.2% anemia, 3.2% neurotoxic effect, and no severe renal toxic effect were recorded. CONCLUSION: Dose-modified Italian PEI should be considered as an appropriate benchmark for CDCT in the first salvage setting.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Cisplatino/administración & dosificación , Etopósido/administración & dosificación , Ifosfamida/administración & dosificación , Neoplasias de Células Germinales y Embrionarias/tratamiento farmacológico , Adulto , Anciano , Supervivencia sin Enfermedad , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/clasificación , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/patología , Humanos , Masculino , Persona de Mediana Edad , Neoplasias de Células Germinales y Embrionarias/patología , Pronóstico , Inducción de Remisión , Terapia Recuperativa , Resultado del Tratamiento
16.
Ann Oncol ; 24(4): 878-88, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23152360

RESUMEN

In November 2011, the Third European Consensus Conference on Diagnosis and Treatment of Germ-Cell Cancer (GCC) was held in Berlin, Germany. This third conference followed similar meetings in 2003 (Essen, Germany) and 2006 (Amsterdam, The Netherlands) [Schmoll H-J, Souchon R, Krege S et al. European consensus on diagnosis and treatment of germ-cell cancer: a report of the European Germ-Cell Cancer Consensus Group (EGCCCG). Ann Oncol 2004; 15: 1377-1399; Krege S, Beyer J, Souchon R et al. European consensus conference on diagnosis and treatment of germ-cell cancer: a report of the second meeting of the European Germ-Cell Cancer Consensus group (EGCCCG): part I. Eur Urol 2008; 53: 478-496; Krege S, Beyer J, Souchon R et al. European consensus conference on diagnosis and treatment of germ-cell cancer: a report of the second meeting of the European Germ-Cell Cancer Consensus group (EGCCCG): part II. Eur Urol 2008; 53: 497-513]. A panel of 56 of 60 invited GCC experts from all across Europe discussed all aspects on diagnosis and treatment of GCC, with a particular focus on acute and late toxic effects as well as on survivorship issues. The panel consisted of oncologists, urologic surgeons, radiooncologists, pathologists and basic scientists, who are all actively involved in care of GCC patients. Panelists were chosen based on the publication activity in recent years. Before the meeting, panelists were asked to review the literature published since 2006 in 20 major areas concerning all aspects of diagnosis, treatment and follow-up of GCC patients, and to prepare an updated version of the previous recommendations to be discussed at the conference. In addition, ∼50 E-vote questions were drafted and presented at the conference to address the most controversial areas for a poll of expert opinions. Here, we present the main recommendations and controversies of this meeting. The votes of the panelists are added as online supplements.


Asunto(s)
Neoplasias de Células Germinales y Embrionarias/patología , Neoplasias de Células Germinales y Embrionarias/terapia , Europa (Continente) , Estudios de Seguimiento , Humanos , Metástasis de la Neoplasia , Estadificación de Neoplasias , Neoplasias de Células Germinales y Embrionarias/clasificación , Neoplasias de Células Germinales y Embrionarias/diagnóstico , Tasa de Supervivencia
17.
J Phys Condens Matter ; 35(47)2023 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-37646378

RESUMEN

Analytical expressions are obtained for the low-field mobility in semiconductors for scattering of three-dimensional (3D), two-dimensional (2D), and one-dimensional (1D) charged carriers by bulk plasmons. The consideration is based on the quantum kinetic equation and model distribution function in form of a shifted Fermi distribution and includes calculations of the dielectric function of 3D, 2D and 1D carriers in the random phase approximation. The resulting analytical expressions give dependences of the plasmon limited mobility on the dimensionality of charge carrier system, their density, effective mass, temperature and confining dimensions. The plasmon limited mobility decreases as the dimensionality of the electron gas D decreases. The physical reason for this is an increase in the absolute value of the cutoff vector with a decrease in D. Comparison of our calculations with known experimental data shows that relative contribution of the electron-plasmon scattering to total mobility reaches a maximum in the temperature range 10-100 K and can be a few percent in bulk crystals, ten of percent in quantum wells, and is close to the experimental values in nanowires. A noticeable effect of the scattering 3D, 2D and 1D electrons by bulk plasmons on mobility is expected in semiconductors with a sufficiently high mobility of more than 105cm2V-1s.

18.
Radiol Med ; 117(4): 593-605, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22020435

RESUMEN

PURPOSE: We analysed our experience with computed tomography (CT)-guided percutaneous cryoablation (PCA) in patients who were not surgical candidates or refused surgery for small to medium-sized renal masses. MATERIALS AND METHODS: Two freezing cycles were applied and separated by a passive warming cycle using 1.7- and 2.4-mm cryoprobes under either general anaesthesia or sedation based on patient positioning and respiratory status. Postoperative monitoring included haematological and biochemistry evaluation and CT scan 24 h after PCA. Follow-up consisted of a multislice CT scan at 1 month and every 3 months in the first year then every 6 months thereafter. RESULTS: Thirty-seven patients (38 lesions) underwent 40 PCA procedures; 5/37 (13.5%) had a solitary kidney. Median mass size was 35 (range 12-70) mm. No complications occurred during the procedure. Clavien grade ≥2 anaemia occurred in two patients (5.4 %): one patient required 1 U of packed red blood cells; the other required an arterial embolisation. Serum creatinine did not increase in any case. Two patients showed persisting or recurrent disease at 1 and 9 months, respectively, and both could be re-treated with PCA. All other patients showed a hypodense mass 3 months after PCA, with no contrast enhancement. Subsequent examinations showed that lesion sizes decreased and CT densitometry remained stable or increased minimally, also with no contrast enhancement. CONCLUSIONS: PCA proved relatively easy and safe and could be considered an effective alternative for patients who are not surgical candidates or refuse surgery, as well as in patients with medium-sized lesions.


Asunto(s)
Criocirugía/métodos , Neoplasias Renales/cirugía , Radiografía Intervencional/métodos , Tomografía Computarizada por Rayos X , Anciano , Anciano de 80 o más Años , Medios de Contraste , Femenino , Humanos , Yopamidol , Neoplasias Renales/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Resultado del Tratamiento
19.
Clin Breast Cancer ; 22(7): 705-714, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35725806

RESUMEN

BACKGROUND: Complex interactions between cancer and the immune system have an impact on disease progression and therapeutic response. Our objective was to evaluate whether circulating immune-related determinants are associated with pathological complete response (pCR) in patients with locally advanced breast cancer (LABC) subjected to neoadjuvant chemotherapy (NACT). PATIENTS AND METHODS: Luminex technology was used to profile 22 cytokines, 10 chemokines, FGF2, PDGF-BB, VEGF, and Ca15-3/Ca125 glycoforms. Measurements were performed alongside standard hematological determinations on pretreatment plasma samples from 151 patients including 41 cases with pCR assessed following RECIST criteria. RESULTS: Random Forest model analysis selected platelets, eotaxin, IFN-γ, IP10, and TGFß2 as significant predictors of pCR. These immune-related features were combined into a quantitative score predictive of pCR. In patients who scored 0 or 1, none had pCR; the pCR frequency increased in relation to the score value (23.5%, 41.2%, and 78.6%, in score groups 2, 3, and 4, respectively). At multivariable logistic analysis, the pCR score was highly significant (odds ratio = 3.15 per unit increment; CI: 1.85-5.38; P < .0001); among clinical covariates (age, menopausal status, tumor stage, IHC subtype, Ki-67, CA15.3, and CA125), only Ki-67 was statistically significant (P = .013). CONCLUSION: This explorative study aimed to lay the conceptual and practical foundation that a distinctive pattern of the immune determinant blood signature at diagnosis of LABC significantly correlates with the patient's response to NACT and provides the groundwork for larger studies that could lead to a minimally invasive tool for personalized medicine.


Asunto(s)
Neoplasias de la Mama , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Becaplermina/uso terapéutico , Neoplasias de la Mama/patología , Quimiocina CXCL10/uso terapéutico , Femenino , Factor 2 de Crecimiento de Fibroblastos/uso terapéutico , Humanos , Antígeno Ki-67 , Terapia Neoadyuvante , Proyectos Piloto , Estudios Retrospectivos , Factor A de Crecimiento Endotelial Vascular
20.
BJU Int ; 107(1): 28-39, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20840664

RESUMEN

OBJECTIVE: To evaluate the role of targeted prostate cancer screening in men with BRCA1 or BRCA2 mutations, an international study, IMPACT (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in BRCA1/2 mutation carriers and controls), was established. This is the first multicentre screening study targeted at men with a known genetic predisposition to prostate cancer. A preliminary analysis of the data is reported. PATIENTS AND METHODS: Men aged 40-69 years from families with BRCA1 or BRCA2 mutations were offered annual prostate specific antigen (PSA) testing, and those with PSA > 3 ng/mL, were offered a prostate biopsy. Controls were men age-matched (± 5 years) who were negative for the familial mutation. RESULTS: In total, 300 men were recruited (205 mutation carriers; 89 BRCA1, 116 BRCA2 and 95 controls) over 33 months. At the baseline screen (year 1), 7.0% (21/300) underwent a prostate biopsy. Prostate cancer was diagnosed in ten individuals, a prevalence of 3.3%. The positive predictive value of PSA screening in this cohort was 47·6% (10/21). One prostate cancer was diagnosed at year 2. Of the 11 prostate cancers diagnosed, nine were in mutation carriers, two in controls, and eight were clinically significant. CONCLUSIONS: The present study shows that the positive predictive value of PSA screening in BRCA mutation carriers is high and that screening detects clinically significant prostate cancer. These results support the rationale for continued screening in such men.


Asunto(s)
Detección Precoz del Cáncer/métodos , Genes BRCA1 , Genes BRCA2 , Predisposición Genética a la Enfermedad/genética , Antígeno Prostático Específico/sangre , Neoplasias de la Próstata/diagnóstico , Adulto , Anciano , Detección Precoz del Cáncer/normas , Métodos Epidemiológicos , Predisposición Genética a la Enfermedad/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Mutación , Neoplasias de la Próstata/sangre , Neoplasias de la Próstata/epidemiología , Neoplasias de la Próstata/genética
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