Influence of the hydrodynamic size and ζ potential of manganese ferrite nanozymes as peroxidase‒mimicking catalysts at ph 4 in different buffers

Peroxidase-mimicking activity of manganese ferrite nanoparticles was studied, based on the oxidation of TMB (3,3’,5,5’-tetramethylbenzidine) by H2O2 at pH 4 using acetate and citrate buffers. The aim of this study was to examine this reaction not only by enzymology (Michaelis-Menten kinetics model) but also by surface science methods of heterogeneous catalysis. Nanoparticles were characterized by different techniques to determine their phase composition, surface area, surface composition, surface charge, pH at the point of zero charge, magnetization, mean size, and morphology. Results show that the nanozymes are coated with buffer anions that form a shell around them. In addition, the hydrodynamic size and ζ potential of the nanoparticles under reaction conditions play an important role in the proposed Fenton-type oxidation mechanism. A greater amount of Mn ions than Fe ions leaches from the nanozymes during TMB oxidation, likely because Fe is better protected than Mn by the buffer coating the outer surface of the nanoparticles. This shortcoming must be addressed when applying these nanomaterials.Operative Program, and Junta de Andalucía FEDER 2014-2020 (Projects FEDER-UJA-138062

Hypermethylated 14-3-3-σ and ESR1 gene promoters in serum as candidate biomarkers for the diagnosis and treatment efficacy of breast cancer metastasis

9 páginas, 5 figuras, 2 tablas.-- et al.[Methods]: We studied two cohorts of patients: 77 patients treated for breast cancer with no signs of disease, and 34 patients with metastatic breast cancer. DNA was obtained from serum samples, and promoter methylation status was determined by using DNA bisulfite modification and quantitative methylation-specific PCR. [Results]: Serum levels of methylated gene promoter 14-3-3-σ significantly differed between Control and Metastatic Breast Cancer groups (P < 0.001), and between Disease-Free and Metastatic Breast Cancer groups (P < 0.001). The ratio of the 14-3-3-σ level before the first chemotherapy cycle to the level just before administration of the second chemotherapy cycle was defined as the Biomarker Response Ratio [BRR]. We calculated BRR values for the "continuous decline" and "rise-and-fall" groups. Subsequent ROC analysis showed a sensitivity of 75% (95% CI: 47.6 - 86.7) and a specificity of 66.7% (95% CI: 41.0 - 86.7) to discriminate between the groups for a cut-off level of BRR = 2.39. The area under the ROC curve (Z = 0.804 ± 0.074) indicates that this test is a good approach to post-treatment prognosis. [Conclusions]: The relationship of 14-3-3-σ with breast cancer metastasis and progression found in this study suggests a possible application of 14-3-3-σ as a biomarker to screen for metastasis and to follow up patients treated for metastatic breast cancer, monitoring their disease status and treatment response.This study was supported by a grant from the Ministerio de Ciencia e Innovación: SAF 2004-00889; JL Linares is supported by the Junta de Andalucía (P06-CTS-1385).Peer reviewe

Método de obtención de un biomaterial

La presente invención está dirigida a un método de obtención de un biomaterial que comprende un soporte de fibras de carbón activado y células de linaje osteocondral, en el que células madre se ponen en contacto con dicho soporte y se cultivan en presencia de suero y ausencia de factores de diferenciación osteogénica y/o condrogénica adicionales. La invención se dirige asimismo al biomaterial así obtenido y a las diferentes aplicaciones médicas de dicho biomaterial.Peer reviewedUniversidad de Granada, Consejo Superior de Investigaciones CientíficasA1 Solicitud de patente con informe sobre el estado de la técnic

Rationale for the Use of Radiation-Activated Mesenchymal Stromal/Stem Cells in Acute Respiratory Distress Syndrome

We have previously shown that the combination of radiotherapy with human umbilical-cord-derived mesenchymal stromal/stem cells (MSCs) cell therapy significantly reduces the size of the xenotumors in mice, both in the directly irradiated tumor and in the distant nonirradiated tumor or its metastasis. We have also shown that exosomes secreted from MSCs preirradiated with 2 Gy are quantitatively, functionally and qualitatively different from the exosomes secreted from nonirradiated mesenchymal cells, and also that proteins, exosomes and microvesicles secreted by MSCs suffer a significant change when the cells are activated or nonactivated, with the amount of protein present in the exosomes of the preirradiated cells being 1.5 times greater compared to those from nonirradiated cells. This finding correlates with a dramatic increase in the antitumor activity of the radiotherapy when is combined with MSCs or with preirradiated mesenchymal stromal/stem cells (MSCs*). After the proteomic analysis of the load of the exosomes released from both irradiated and nonirradiated cells, we conclude that annexin A1 is the most important and significant difference between the exosomes released by the cells in either status. Knowing the role of annexin A1 in the control of hypoxia and inflammation that is characteristic of acute respiratory-distress syndrome (ARDS), we designed a hypothetical therapeutic strategy, based on the transplantation of mesenchymal stromal/stem cells stimulated with radiation, to alleviate the symptoms of patients who, due to pneumonia caused by SARS-CoV-2, require to be admitted to an intensive care unit for patients with life-threatening conditions. With this hypothesis, we seek to improve the patients’ respiratory capacity and increase the expectations of their cure.Ministerio de Economia y Competividad MINECO: SAF2012-40011-C02-02 SAF2015-70520-R RTICC RD12/0036/002

The E-screen assay: a comparison of different MCF7 cell stocks

This work was reported in part at the meeting "Estrogens in the Environment III: Global Health Implications," held in Washington, DC, 9-11 January 1994.MCF7 human breast cancer cells have been studied extensively as a model for hormonal effects on breast cancer cell growth and specific protein synthesis. Because the proliferative effect of natural estrogen is considered the hallmark of estrogen action, it was proposed that this property be used to determine whether a substance is an estrogen. The E-screen assay, developed for this purpose, is based on the ability of MCF7 cells to proliferate in the presence of estrogens. The aim of our study was to characterize the response of four MCF7 cell stocks (BUS, ATCC, BB, and BB104) and determine which of them performed best in the E-screen test. The four stocks assayed were distinguishable by their biological behavior. In the absence of estrogen, MCF7 BUS cells stopped proliferating and accumulated in the G(0)/G(1) phase of the cell cycle; estrogen receptors increased, progesterone receptors decreased, and small amounts of pS2 protein were secreted. Of all the MCF7 stocks tested, MCF7 BUS cells showed the highest proliferative response to estradiol-17B: cell yields increased up to sixfold over those of nontreated cells in a 144-hr period. The differences between estrogen-supplemented and nonsupplemented MCF7 BUS cells were due mostly to G(0)/G(1) proliferative arrest mediated by charcoal dextran-srripped serum. MCF7 BUS cell stocks and others showing a similar proliferative pattern should be chosen for use in the E-screen test, or,whenever a proliferative effect of estrogen is to be demonstrated.This work was supported by grant 94/1551 from the Fondo de Investigaciones Sanitarias, Spanish Ministry of Health

Estudio de las interacciones sobre los iones Ca2+ con la imipramida y la maprotilina en medio acuoso. II. – Funciones termodinámicas de activación

A partir de los coeficientes de difusión, determinados a diferentes temperaturas, se han calculado las energías de activación de los procesos de difusión de los iones Ca2 + en las disoluciones acuosas, en ausencia y en presencia de imipramina y de maprotilina. Asimismo se han calculado las distancias cuadráticas medias netas por salto iónico, tiempo invertido en cada salto iónico, velocidades específicas netas de difusión, entalpías, entropías y energías libres de activacíón.The activation energies for the diffusion process of Ca2 + ions through aqueous solutions, with and without imipramine and maprotiline, have been caIculated from the diffusion coeflcients at different temperatures. The mean square distances for ionic jumps, mean times for ionic jumps, net specific velocities of diffusion, enthalpi-es, enthropies and free activation energies have be en also calculated

Selective use of postoperative neck radiotherapy in oral cavity and oropharynx cancer: a prospective clinical study

Background: In cervical postoperative radiotherapy, the target volume is usually the same as the extension of the previous dissection. We evaluated a protocol of selective irradiation according to the risk estimated for each dissected lymph node level. Methods: Eighty patients with oral/oropharyngeal cancer were included in this prospective clinical study between 2005 and 2008. Patients underwent surgery of the primary tumor and cervical dissection, with identification of positive nodal levels, followed by selective postoperative radiotherapy. Three types of selective nodal clinical target volume (CTV) were defined: CTV0, CTV1, and CTV2, with a subclinical disease risk of < 10%, 10-25%, and 25% and a prescribed radiation dose of < 35 Gy, 50 Gy, and 66-70 Gy, respectively. The localization of node failure was categorized as field, marginal, or outside the irradiated field. Results: A consistent pattern of cervical infiltration was observed in 97% of positive dissections. Lymph node failure occurred within a high-risk irradiated area (CTV1-CTV2) in 12 patients, marginal area (CTV1/CTVO) in 1 patient, and non-irradiated low-risk area (CTV0) in 2 patients. The volume of selective lymph node irradiation was below the standard radiation volume in 33 patients (mean of 118.6 cc per patient). This decrease in irradiated volume was associated with greater treatment compliance and reduced secondary toxicity. The three-year actuarial nodal control rate was 80%. Conclusion: This selective postoperative neck irradiation protocol was associated with a similar failure pattern to that observed after standard neck irradiation and achieved a significant reduction in target volume and secondary toxicity.This work was supported, in part, by Grants-in-Aid for Scientific Research from the Health Andalusian Authority PI-SAS-209/04

Poli (ADP-Ribosa) Polimerasa-1: una proteína nuclear implicada en procesos inflamatorios, muerte celular y cáncer

Numerosos estudios en modelos experimentales han puesto de manifiesto que el bloqueo genético o lainhibición farmacológica de poli-ADP-ribosa-polimerasa-1, proteína nuclear implicada en fenómenos deseñalización celular a través de modificaciones postraduccionales mediante poli-ADP-ribosilación, confiereprotección frente a procesos citolíticos derivados que tienen lugar durante el desarrollo de la respuestainflamatoria. Un denominador común en todos los procesos inflamatorios es la secreción de diversosmediadores proinflamatorios y la formación de radicales libres que van a desencadenar la activación de poli-ADP-ribosa-polimerasa-1 y simultáneamente se potencia la activación de diversos factores de transcripcióncomo NF-kB y AP-1, dando lugar a la expresión de genes dependientes de éstos. Es bien conocido que lainflamación en el cáncer, como proceso de estrés oxidativo continuo, actúa como un fuerte promotor tumoralfavoreciendo el desarrollo del tumor. Esta revisión pretende dar una visión general sobre el conocimientoactual de esta proteína tanto a nivel celular como en procesos patológicos tan importantes como el cáncer. PALABRAS CLAVE: PARP-1, Inflamación, Cáncer, Factores de Transcripción

Interaction between ATM and PARP-1 in response to DNA damage and sensitization of ATM deficient cells through PARP inhibition

ATM and PARP-1 are two of the most important players in the cell's response to DNA damage. PARP-1 and ATM recognize and bound to both single and double strand DNA breaks in response to different triggers. Here we report that ATM and PARP-1 form a molecular complex in vivo in undamaged cells and this association increases after γ-irradiation. ATM is also modified by PARP-1 during DNA damage. We have also evaluated the impact of PARP-1 absence or inhibition on ATM-kinase activity and have found that while PARP-1 deficient cells display a defective ATM-kinase activity and reduced γ-H2AX foci formation in response to γ-irradiation, PARP inhibition on itself is able to activate ATM-kinase. PARP inhibition induced γ H2AX foci accumulation, in an ATM-dependent manner. Inhibition of PARP also induces DNA double strand breaks which were dependent on the presence of ATM. As consequence ATM deficient cells display an increased sensitivity to PARP inhibition. In summary our results show that while PARP-1 is needed in the response of ATM to gamma irradiation, the inhibition of PARP induces DNA double strand breaks (which are resolved in and ATM-dependent pathway) and activates ATM kinase

Early and late skin reactions to radiotherapy for breast cancer and their correlation with radiation-induced DNA damage in lymphocytes

INTRODUCTION: Radiotherapy outcomes might be further improved by a greater understanding of the individual variations in normal tissue reactions that determine tolerance. Most published studies on radiation toxicity have been performed retrospectively. Our prospective study was launched in 1996 to measure the in vitro radiosensitivity of peripheral blood lymphocytes before treatment with radical radiotherapy in patients with breast cancer, and to assess the early and the late radiation skin side effects in the same group of patients. We prospectively recruited consecutive breast cancer patients receiving radiation therapy after breast surgery. To evaluate whether early and late side effects of radiotherapy can be predicted by the assay, a study was conducted of the association between the results of in vitro radiosensitivity tests and acute and late adverse radiation effects. METHODS: Intrinsic molecular radiosensitivity was measured by using an initial radiation-induced DNA damage assay on lymphocytes obtained from breast cancer patients before radiotherapy. Acute reactions were assessed in 108 of these patients on the last treatment day. Late morbidity was assessed after 7 years of follow-up in some of these patients. The Radiation Therapy Oncology Group (RTOG) morbidity score system was used for both assessments. RESULTS: Radiosensitivity values obtained using the in vitro test showed no relation with the acute or late adverse skin reactions observed. There was no evidence of a relation between acute and late normal tissue reactions assessed in the same patients. A positive relation was found between the treatment volume and both early and late side effects. CONCLUSION: After radiation treatment, a number of cells containing major changes can have a long survival and disappear very slowly, becoming a chronic focus of immunological system stimulation. This stimulation can produce, in a stochastic manner, late radiation-related adverse effects of varying severity. Further research is warranted to identify the major determinants of normal tissue radiation response to make it possible to individualize treatments and improve the outcome of radiotherapy in cancer patients