Gamma probe sentinel node localization and biopsy in breast cancer patients treated with a neoadjuvant chemotherapy scheme

The aim of this study was to analyse the accuracy of scintigraphic and gamma probe sentinel node (SN) localization in breast cancer patients who have been submitted to neoadjuvant chemotherapy (NC). Seventy-six patients with single breast cancer were included in the study, and were classified into two groups. Group 1 consisted of 40 women who had received NC, and Group 2 consisted of 36 women who did not receive NC. All patients received 111 MBq (3 mCi) of 99Tcm-nanocolloid in 3 ml, by peritumoural injection. Anterior and lateral thoracic scans were obtained 2 h post-injection. The following day (18-24 h post-injection) the patients underwent surgery and sentinel nodes were localized by using a gamma probe. Complete axillary lymph node dissection was performed in all patients. Histological analysis included haematoxylin-eosin in all cases and immunohistochemistry in 10 cases. In Group 1, SNs were localized in 36/40 patients, histological analysis was performed in 34 and there were four false negatives (22%). In Group 2, SNs were localized in 32/36 patients, histological analysis was performed in 29 and there were two false negatives (9%). Predictive negative values were 78% and 90% in Groups 1 and 2, respectively. In summary, sentinel node localization in breast cancer patients submitted to previous neoadjuvant chemotherapy is less accurate than in patients who do not receive this therapy. The procedure is not sufficiently accurate to localize the sentinel node, thus it cannot be recommended in these patients

Biorremediación de suelos contaminados por hidrocarburos pesados y caracterización de comunidades microbianas implicadas

[spa] La presente tesis doctoral tiene como principal objetivo aportar conocimiento en el área de la biorremediación de suelos contaminados por hidrocarburos, mediante el estudio a escala real y de laboratorio de tratamientos enfocados a mejorar la degradación de los contaminantes y el uso de técnicas moleculares para determinar la biodiversidad microbiana presente en el suelo, así como su evolución a lo largo de dichos tratamientos. Los estudios llevados a cabo pretenden abordar aspectos todavía no resueltos y por tanto necesitados de investigación. En primer lugar la presencia de hidrocarburos de elevado peso molecular como las fracciones alifáticas pesadas o los HAPs de 4 y 5 anillos, en concentraciones excesivamente elevadas después de aplicar la biotecnología de la biorremediación con técnicas convencionales como la aireación y la adición de nutrientes. Otro aspecto a resolver es la falta de accesibilidad de estas moléculas de excesivo tamaño molecular a aquellos microrganismos capaces de metabolizarlas. Cabe resaltar que mientras el grupo de investigación logró muy buenos resultados en la utilización de biosurfactantes para mejorar la biodisponibilidad de hidrocarburos de elevado peso molecular en medio líquido, los intentos llevados a cabo en distintos suelos, no condujeron a ninguna mejora de la biodegradación. Finalmente el reto más importante que actualmente tiene la comunidad científica, es aumentar el conocimiento de las poblaciones microbianas implicadas en los procesos de biorremediación. Deberíamos dejar la pura descripción para alcanzar el objetivo último que sería conocer qué función está llevando a cabo cada microorganismo identificado. Por suerte, las metodologías moleculares que están evolucionando vertiginosamente nos están ofreciendo el camino. Relacionado con este aspecto, y que quizás no ha sido abordado suficientemente, estaría el conocimiento de las interacciones entre bacterias y hongos o entre poblaciones autóctonas y aquellas introducidas como inóculos en procesos de bioaumentación. El presente trabajo de tesis doctoral aborda todos estos aspectos que se exponen en seis capítulos: (I) a multi-approach assessment to evaluate biostimulation and bioaugmentation strategies for heavily oil-contaminated soil, (II) ensayo piloto de biorremediación por tecnología de la biopila dinámica para la descontaminación de suelos contaminados por creosotas provenientes de las actividades dedicadas a la preparación de la madera, (III) microbial populations related to PAH biodegradation in an aged biostimulated creosote-contaminated soil, (IV) Fungal/bacterial interactions throughout bioremediation assays in an aged creosote polluted soil, (V) Comparative assessment of bioremediation approaches to highly recalcitrant PAH degradation in a real industrial polluted soil y (VI) Combining DGGE and barcoded pyrosequencing for microbial community characterization throughout different soil bioremediation strategies in an aged creosote-polluted soil.[eng] The main objective of the present thesis work is to provide knowledge in the field of bioremediation of hydrocarbon contaminated soils, by performing field-scale and lab-scale treatments focused on improving the degradation of organic pollutants and the use of molecular techniques to determine the microbial biodiversity present in the soil and their evolution due to the treatment effect. The studies carried out intended to address unresolved issues and therefore in need of investigation. Firstly, the presence of high molecular weight hydrocarbon fractions such as heavy aliphatic or 4 and 5-ring PAHs, in excessively high concentrations after application of bioremediation biotechnology techniques as aeration and addition of nutrients. Another issue to address is the lack of accessibility of these high molecular weight compounds for those microorganisms able to metabolize them. It is noteworthy that while our research group obtained very good results using biosurfactants to improve bioavailability of PAHs in liquid medium, the attempts made in different soils did not lead to any improvement in biodegradation. Finally, the most important challenge that currently has the scientific community in our research field is to increase the knowledge of microbial populations involved in bioremediation processes. We should achieve the objective of knowing what function is conducting each organism identified and try to forget the simply ecological description. Fortunately, molecular methodologies are faster than before. Related to this aspect, it is important to highlight the paramount importance for bioremediation success of the interactions between bacteria and fungi or between indigenous communities and those introduced as inoculum in bioaugmentation processes. The present doctoral thesis deal with all these issues, which are presented in six chapters: (I) a multi-approach assessment to evaluate biostimulation and bioaugmentation strategies for heavily oil-contaminated soil, (II) ensayo piloto de biorremediación por tecnología de la biopila dinámica para la descontaminación de suelos contaminados por creosotas provenientes de las actividades dedicadas a la preparación de la madera, (III) microbial populations related to PAH biodegradation in an aged biostimulated creosote-contaminated soil, (IV) Fungal/bacterial interactions throughout bioremediation assays in an aged creosote polluted soil, (V) Comparative assessment of bioremediation approaches to highly recalcitrant PAH degradation in a real industrial polluted soil and (VI) Combining DGGE and barcoded pyrosequencing for microbial community characterization throughout different soil bioremediation strategies in an aged creosote-polluted soil

Fungal and bacterial microbial community assessment during bioremediation assays in an aged creosote-polluted soil

The application of bioremediation technologies to polycyclic aromatic hydrocarbon (PAH)-contaminated soils does not remove the excess of the high-molecular-weight fraction (HMW-PAHs), as has been widely reported. Taking into account the metabolic capacities of white-rot fungi, their bioaugmentation has been extensively assayed on polluted soils, but with controversial results. The aim of this study is to gain insight into how fungal bioaugmentation assays affect both PAH degradation and autochthonous microbial populations in a previously biotreated aged creosote-polluted soil contaminated with HMW-PAHs. To this end, we performed a set of slurry bioassays encompassing different biostimulation and bioaugmentation strategies. The results show that the autochthonous microbial populations degraded PAHs the most; specifically, the 4-ring PAHs under carbon-limiting conditions (26% and 28% degradation for benzo(a)anthracene and chrysene respectively). Although Trametes versicolor amendment produced the highest depletion of benzo(b + k)fluoranthene and benzo(a)pyrene concentrations in an autoclaved soil, it did not improve either the 4-ring or the 5-ring PAH degradation, when active native PAH-degrading microbiota was present. Microbial community analysis of fungal and eubacterial populations, based on the 16SrRNA gene and ITS1 region respectively, revealed that the ribotypes closely related to the eubacterial genera Chryseobacterium, Pusillimonas and Sphingobium, that are concomitant with the autochthonous fungal genus Fusarium, could be important in HMW-PAH degradation processes in polluted soils. Antagonistic effects or resource competition resulting from the effects of active native soil microbiota on augmented white-rot fungi should be evaluated in polluted soil before scaling up the remediation process to field scale

Comparative assessment of bioremediation approaches to highly recalcitrant PAH degradation in a real industrial polluted soil

High recalcitrant characteristics and low bioavailability rates due to aging processes can hinder high molecular weight polycyclic aromatic hydrocarbons (HMW-PAHs) bioremediation in real industrial polluted soils. With the aim of reducing the residual fraction of total petroleum hydrocarbons (TPH) and (HMW-PAHs) in creosote-contaminated soil remaining after a 180-d treatment in a pilot-scale biopile, either biostimulation (BS) of indigenous microbial populations with a lignocellulosic substrate (LS) or fungal bioaugmentation with two strains of white-rot fungi (WRF) (i.e., Trametes versicolor and Lentinus tigrinus) were comparatively tested. The impact of bivalent manganese ions and two mobilizing agents (MAs) (i.e., Soybean Oil and Brij 30) on the degradation performances of biostimulated and bioaugmented microcosms was also compared. The results reveal soil colonization by both WRF strains was clearly hampered by an active native soil microbiota. In fact, a proper enhancement of native microbiota by means of LS amendment promoted the highest biodegradation of HMW-PAHs, even of those with five aromatic rings after 60 days of treatment, but HMW-PAH-degrading bacteria were specifically inhibited when non-ionic surfactant Brij 30 was amended. Effects of bioaugmentation and other additives such as non-ionic surfactants on the degrading capability of autochthonous soil microbiota should be evaluated in polluted soils before scaling up the remediation process at field scale

A diversified approach to evaluate biostimulation and bioaugmentation strategies for heavy-oil-contaminated soil

A diversified approach involving chemical, microbiological and ecotoxicity assessment of soil polluted by heavy mineral oil was adopted, in order to improve our understanding of the biodegradability of pollutants, microbial community dynamics and ecotoxicological effects of various bioremediation strategies. With the aim of improving hydrocarbon degradation, the following bioremediation treatments were assayed: i) addition of inorganic nutrients; ii) addition of the rhamnolipid-based biosurfactant MAT10; iii) inoculation of an aliphatic hydrocarbon-degrading microbial consortium (TD); and iv) inoculation of a known hydrocarbon-degrading white-rot fungus strain of Trametes versicolor. After 200 days, all the bioremediation assays achieved between 30% and 50% total petroleum hydrocarbon (TPH) biodegradation, with the T. versicolor inoculation degrading it the most. Biostimulation and T. versicolor inoculation promoted the Brevundimonas genus concurrently with other α-proteobacteria, β-proteobacteria and Cytophaga-Flexibacter-Bacteroides (CFB) as well as Actinobacteria groups. However, T. versicolor inoculation, which produced the highest hydrocarbon degradation in soil, also promoted autochthonous Gram-positive bacterial groups, such as Firmicutes and Actinobacteria. An acute toxicity test using Eisenia fetida confirmed the improvement in the quality of the soil after all biostimulation and bioaugmentation strategies