Estima de l'heretabilitat d'alguns caràcters mètrics d'una població de drosophila melanogaster del Prat de Llobregat

Hem calculat l'heretabilitat de les microquetes interocel·lars,esternopleurals i abdominals, i de la longitud de la tíbia d'una soca de Drosophila melanogaster del Prat de Llobregat. El metode de calcul utilitzat és el de la regressió de la progenie sobre el progenitor. Llevat de les particularitats relatives a cadascun dels caracters, els valors obtinguts són els que cabia esperar d'acord amb la naturalesa poligenica dels caracters estudiats, i les diferencies deuen tenir, fonamentalment, una base genètica. El fet que els nostres valors siguin intermedis pot ésser degut que la soca estudiada sigui heterozigdtica per a un gran nombre de loci. Les heretabilitats obtingudes fan suposar que els caracters estudiats són determinants poc importants de l'eficacia biologica.The heritability of interocellar, sternopleural and abdominal bristles, and tibia length, was estimated in a natural populations of Drosophila melanogaster from Prat de Llobregat (Barcelona) by the method of parent-offspring regression. The values of the estimated heritability are similar and the differences found must have a genetical basis. Our results are similar to the ones found by other authors witht different polygenic traits and they agree with the nature of the characters. The reason why the found heritabilities are intermediates may be because'the studied population is heterozygotic for a lot of loci

Contribució cromosòmica a la resposta a la selecció de les microquetes interocel.lars de Drosophila Melanogaster

Hem analitzat la importancia que tenen els diferents cromosomes de Drosophila melanogaster en la manifestació del nombre de microquetes interocel·lars i hem evaluat l'efecte de les interaccions cromosomiques. L'experiment s'ha realitzat sobre vuit línies seleccionades, emprant l'analisi substitucional. Els resultats obtinguts indiquen que, malgrat que els tres cromosomes majors són portadors d'agents amb efecte sobre el caracter, la seva importancia relativa depen del tipus de selecció practicada. Així, mentre que a les línies per disminució trobem efecte clar i positiu dels cromosomes X i III, i molt poc efecte del cromosoma Il. a les línies per augment trobem que els cromosomes II i III tenen efecte clar i positiu i que, en canvi, el cromosoma X te efecte negatiu molt fort.The importance of the different chromosomes in the manifestation of interocellar bristles in Drosophila melanogaster has been analysed. This study has been carried out on eight selection lines by means of substitucional analysis. The resultats found show that although on the three major chromosomes are located agents with effect on the studied trait, their relative importance depends on the selection applied. Thus, while in the low lines there is a clear and positive effect in first and third chromosomes, and a mild effect in second chromosome, in the high lines the second and third chromosomes have a clear and positive effect and the first chromosome a very significant and negative effect

Genotoxic and antigenotoxic properties of selenium compounds in the in vitro

Selenium is known to possess both genotoxic and antigenotoxic properties. In the present study, we have evaluated the genotoxicity and antigenotoxicity of three selenium compounds (sodium selenate, sodium selenite and selenous acid) by measuring in vitro micronucleus induction. Assays were conducted in whole blood lymphocytes and in the TK6 lymphoblastoid cell line, with and without co-treatment with potassium dichromate, a known genotoxic compound. In general, the compounds were more active in TK6 cells than they were in blood lymphocytes. Only 1 μM selenous acid increased the frequency of binucleated cells containing micronuclei (BNMN) in blood lymphocytes, while all three selenium compounds increased BNMN in TK6 cells. In addition, combinations of selenous acid and potassium dichromate resulted in lower frequencies of BNMN than potassium dichromate alone in blood lymphocytes, while combinations of sodium selenate and potassium dichromate produced lower frequencies of BNMN than potassium dichromate alone in TK6 cells. The concentrations of selenium compounds that were used, in combination with the medium components and the biological physiology of the whole blood lymphocytes and TK6 cells, could have affected the redox potential of the compounds, switching the chemicals from a pro-oxidant to antioxidant status and vice-versa. The lower activities of the compounds in blood lymphocytes may be due to the protective effects of blood components. The results indicate that the genotoxic and antigenotoxic properties of selenium compounds are highly dependent upon the conditions under which they are evaluated

Insights into the potential carcinogenicity of micro- and nano-plastics

There is a growing concern regarding the potential health effects that continuous exposure to environmental micro- and nano-plastics (MNPLs) may cause on humans. Due to their persistent nature, MNPLs may accumulate in different organs and tissues and may induce in the long term the development of cancer. The present study aimed to review the existing literature on the carcinogenic potential of MNPLs. As studies directly assessing carcinogenicity were expected to be scarce, studies dealing with indirect outcomes associated with the carcinogenic process were considered in the literature search. Of the 126 studies screened, 19 satisfied the inclusion criteria. Besides, 7 additional cross-referenced articles, identified through a careful reading of the previously selected papers, also met the inclusion criteria and, consequently, were included in the review. Most of the selected studies were performed using in vitro models whereas about 40% of the studies were done in rodents, although none of them included a 2-year carcinogenicity assay. Most of the reviewed studies pointed out the potential of MNPLs to induce inflammation and genotoxicity, the latter being recognized as a strong predictor of carcinogenicity. These, along with other important findings such as the MNPLs’ ability to accumulate into cells and tissues, or their capacity to induce fibrosis, may suggest an association between MNPLs exposures and the carcinogenic potential. Nevertheless, the limited number of available studies precludes reaching clear conclusions. Therefore, this review also provides several recommendations to cover the current knowledge gaps and address the future evaluation of the MNPLs’ carcinogenic risk

Biodistribution of Liposome-Encapsulated Bacteriophages and Their Transcytosis During Oral Phage Therapy

This study sheds light on the biodistribution of orally administered, liposome-encapsulated bacteriophages, and their transcytosis through intestinal cell layers. Fluorochrome-labeled bacteriophages were used together with a non-invasive imaging methodology in the in vivo visualization of bacteriophages in the stomach and intestinal tract of mice. In those studies, phage encapsulation resulted in a significant increase of the labeled phages in the mouse stomach, even 6 h after their oral administration, and without a decrease in their concentration. By contrast, the visualization of encapsulated and non-encapsulated phages in the intestine were similar. Our in vivo observations were corroborated by culture methods and ex vivo experiments, which also showed that the percentage of encapsulated phages in the stomach remained constant (50%) compared to the amount of initially administered product. However, the use of conventional microbiological methods, which employ bile salts to break down liposomes, prevented the detection of encapsulated phages in the intestine. The ex vivo data showed a higher concentration of non-encapsulated than encapsulated phages in liver, kidney, and even muscle up to 6 h post-administration. Encapsulated bacteriophages were able to reach the liver, spleen, and muscle, with values of 38% ± 6.3%, 68% ± 8.6%, and 47% ± 7.4%, respectively, which persisted over the course of the experiment. Confocal laser scanning microscopy of an in vitro co-culture of human Caco-2/HT29/Raji-B cells revealed that Vybrant-Dil-stained liposomes containing labeled bacteriophages were preferably embedded in cell membranes. No transcytosis of encapsulated phages was detected in this in vitro model, whereas SYBR-gold-labeled non-encapsulated bacteriophages were able to cross the membrane. Our work demonstrates the prolonged persistence of liposome-encapsulated phages in the stomach and their adherence to the intestinal membrane. These observations could explain the greater long-term efficacy of phage therapy using liposome-encapsulated phages

Genotoxicity of Copper and Nickel Nanoparticles in Somatic Cells of Drosophila melanogaster

Copper and nickel nanoparticles (Cu-NPs and Ni-NPs, respectively) are used in a variety of industrial applications, such as semiconductors, catalysts, sensors, and antimicrobial agents. Although studies on its potential genotoxicity already exist, few of them report in vivo data. In the present study we have used the wing-spot assay in Drosophila melanogaster to determine the genotoxic activity of Cu-NPs and Ni-NPs, and these data have been compared with those obtained with their microparticle forms (MPs). Additionally, a complete physical characterization of NPs using transmission electronic microscopy (TEM), dynamic light scattering (DLS), and laser Doppler velocimetry (LDV) techniques was also performed. Results obtained with Cu-NPs and Cu-MPs indicate that both failed to induce an increase in the frequency of mutant spots formation in the wings of the adults, suggesting a lack of genotoxicity in somatic cells of D. melanogaster. However, when Ni-NPs and Ni-MPs were evaluated, a significant increase of small single spots and total mutant spots was observed only for Ni-NPs (P<0.05) at the highest dose assessed. Thus, the genotoxicity of Ni-NPs seem to be related to their nanoscale size, because no genotoxic effects have been reported with their microparticles and ions. This study is the first assessing the in vivo genotoxic potential of Cu-NPs and Ni-NPs in the Drosophila mode

Possible role of WDR3 gene on genome stability in thyroid cancer patients

The role of the WDR3 gene on genomic instability has been evaluated in a group of 115 differentiated thyroid cancer (DTC) patients. Genomic instability has been measured according to the response of peripheral blood lymphocytes to ionizing radiation (0.5 Gy). The response has been measured with the micronucleus (MN) test evaluating the frequency of binucleated cells with MN (BNMN), both before and after the irradiation. No differences between genotypes, for the BNMN frequencies previous the irradiation, were observed. Nevertheless significant decreases in DNA damage after irradiation were observed in individuals carrying the variant alleles for each of the three genotyped SNPs: rs3754127 [−8.85 (−15.01 to −2.70), P<0.01]; rs3765501 [−8.98 (−15.61 to −2.36), P<0.01]; rs4658973 [−8.70 (−14.94 to −2.46), P<0.01]. These values correspond to those obtained assuming a dominant model. This study shows for the first time that WDR3 can modulate genome stability

A new source of representative secondary PET nanoplastics. Obtention, characterization, and hazard evaluation

Acord transformatiu CRUE-CSICAltres ajuts: Juan de la Cierva IJC2020-2686IMicro and nanoplastics (MNPLs) are emergent environmental pollutants requiring urgent information on their potential risks to human health. One of the problems associated with the evaluation of their undesirable effects is the lack of representative samples, matching those resulting from the environmental degradation of plastic wastes. To such end, we propose an easy method to obtain polyethylene terephthalate nanoplastics from water plastic bottles (PET-NPLs) but, in principle, applicable to any other plastic goods sources. An extensive characterization indicates that the proposed process produces uniform samples of PET-NPLs of around 100 nm, as determined by using AF4 and multi-angle and dynamic light scattering methodologies. An important point to be highlighted is that to avoid the metal contamination resulting from methods using metal blades/burrs for milling, trituration, or sanding, we propose to use diamond burrs to produce metal-free samples. To visualize the toxicological profile of the produced PET-NPLs we have evaluated their ability to be internalized by cells, their cytotoxicity, their ability to induce oxidative stress, and induce DNA damage. In this preliminary approach, we have detected their cellular uptake, but without the induction of significant biological effects. Thus, no relevant increases in toxicity, reactive oxygen species (ROS) induction, or DNA damage -as detected with the comet assay- have been observed. The use of representative samples, as produced in this study, will generate relevant data in the discussion about the potential health risks associated with MNPLs exposures

Renal Transplantation in Systemic Lupus Erythematosus: Outcome and Prognostic Factors in 50 cases from a Single Centre.

Background. End-stage renal disease (ESRD) is an important cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE). Objectives. To analyze the outcome and prognostic factors of renal transplantation in patients with ESRD due to SLE from January 1986 to December 2013 in a single center. Results. Fifty renal transplantations were performed in 40 SLE patients (32 female (80%), mean age at transplantation 36 ± 10.4 years). The most frequent lupus nephropathy was type IV (72.2%). Graft failure occurred in a total of 15 (30%) transplantations and the causes of graft failure were chronic allograft nephropathy (), acute rejection (), and chronic humoral rejection (1). The death-censored graft survival rates were 93.9% at 1 year, 81.5% at 5 years, and 67.6% at the end of study. The presence of deceased donor allograft () and positive anti-HCV antibodies () negatively influence the survival of the renal transplant. The patient survival rate was 91.4% at the end of the study. Recurrence of lupus nephritis in renal allograft was observed in one patient. Conclusion. Renal transplantation is a good alternative for renal replacement therapy in patients with SLE. In our cohort, the presence of anti-HCV antibodies and the type of donor source were related to the development of graft failure

Micronuclei detection by flow cytometry as a high-throughput approach for the genotoxicity testing of nanomaterials

Thousands of nanomaterials (NMs)-containing products are currently under development or incorporated in the consumer market, despite our very limited understanding of their genotoxic potential. Taking into account that the toxicity and genotoxicity of NMs strongly depend on their physicochemical characteristics, many variables must be considered in the safety evaluation of each given NM. In this scenario, the challenge is to establish high-throughput methodologies able to generate rapid and robust genotoxicity data that can be used to critically assess and/or predict the biological effects associated with those NMs being under development or already present in the market. In this study, we have evaluated the advantages of using a flow cytometry-based approach testing micronucleus (MNs) induction (FCMN assay). In the frame of the EU NANoREG project, we have tested six different NMs-namely NM100 and NM101 (TiO2NPs), NM110 (ZnONPs), NM212 (CeO2NPs), NM300K (AgNPs) and NM401 (multi-walled carbon nanotubes (MWCNTs)). The obtained results confirm the ability of AgNPs and MWCNTs to induce MN in the human bronchial epithelial BEAS-2B cell line, whereas the other tested NMs retrieved non-significant increases in the MN frequency. Based on the alignment of the results with the data reported in the literature and the performance of the FCMN assay, we strongly recommend this assay as a reference method to systematically evaluate the potential genotoxicity of NMs