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Abstract: The fungus Phyllosticta citricarpa is a quarantine pathogen in the EU and is of high economic importance in many parts of the world where favourable climate conditions drive the development of citrus black spot (CBS) disease. Disease symptoms include necrotic lesions on leaves and fruits. Low disease pressure can reduce crop market-ability, while higher disease pressure can cause premature fruit drop, significantly increasing crop losses. The wind-dispersed spores of P. citricarpa are especially prob-lematic for rapid pathogen dispersal, but also provide an opportunity for early detec-tion of the disease spreading into a new area. In this study we have developed and validated a quantitative PCR (qPCR) assay based on the TEF1-α sequence. Specificity testing demonstrated that it is currently the only qPCR assay that does not cross- react with closely related Phyllosticta species. The assay is sensitive and can detect a single copy of the TEF1 gene in a reaction, it is highly repeatable and reproducible and can be used for testing of the sticky tapes from spore traps as well as citrus fruit sam-ples. High-throughput sequencing (HTS) of the DNA barcodes ITS1 and TEF1 was also explored for the detection and discrimination of P. citricarpa. The limit of detection of the HTS was 1000 spores on a daily spore trap tape. This study makes an important improvement to the diagnostics of the CBS and the methods developed can also be applied to improve the surveillance and early detection of the pathogen when linked to spore samplers in the field.
Keywords: detection, fungal spore sampling, internal transcribed region (ITS), translation elongation factor 1-α (TEF1)
Published in DiRROS: 12.07.2024; Views: 274; Downloads: 244
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Abstract: ackground p16/Ki-67 dual immunocytochemical staining (DS) is considered easy to interpret if evaluators are properly trained, however, there is no consensus on what constitutes proper training. In the present study we evaluated a protocol for teaching DS evaluation on students inexperienced in cervical cytology. Methods Initial training on 40 DS conventional smears was provided by a senior cytotechnologist experienced in such evaluation. Afterwards, two students evaluated 118 cases. Additional training consisted mainly of discussing discrepant cases from the first evaluation and was followed by evaluation of new 383 cases. Agreement and accuracy of students' results were compared among the participants and to the results of the reference after both evaluations. We also noted time needed for evaluation of one slide as well as intra-observer variability of the teacher's results. Results At the end of the study, agreement between students and reference was higher compared to those after initial training (overall percent agreement [OPA] 81.4% for each student, kappa 0.512 and 0.527 vs. OPA 78.3% and 87.2%, kappa 0.556 and 0.713, respectively). However, accuracy results differed between the two students. After initial training sensitivity was 4.3% points and 2.9% points higher, respectively compared to the reference, while specificity was 30.6% points and 24.4% points lower, respectively, compared to the reference. At the end of the study, the sensitivity reached by one student was the same as that of the reference, while it was 2.6% points lower for the other student. There was a statistically significant difference in specificity between one student and the reference and also between students (16.7 and 15.1% points). Towards the end of the study, one student needed 5.2 min for evaluating one slide while the other needed 8.2 min. The intra-observer variability of the senior cytotechnologist was in the range of "very good" in both arms of the study. Conclusions In teaching DS evaluation, the students' progress has to be monitored using several criteria like agreement, accuracy and time needed for evaluating one slide. The monitoring process has to continue for a while after students reach satisfactory results in order to assure a continuous good performance. Monitoring of teacher's performance is also advisable.
Keywords: cervical cytology, cervical cancer, immunocytochemistry, accuracy
Published in DiRROS: 11.07.2024; Views: 333; Downloads: 226
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Abstract: Based on recent data from clinical trials, the immune checkpoint inhibitor pembrolizumab prolongs survival and has a good toxicity profile in patients with advanced or metastatic melanoma. However, the question remains whether these results are transmitted into daily clinical practice. The aim of this study was to assess the efficacy and toxicity of pembrolizumab in treatment-naive patients with metastatic melanoma in everyday clinical practice in Slovenia and compare it to the results from clinical trials. Patients and methods. This observational retrospective cohort study included 138 consecutive metastatic treatment-naive melanoma patients treated with pembrolizumab at the Institute of Oncology Ljubljana in Slovenia, from January 2016 to December 2018. Patient and treatment characteristics were retrospectively collected from hospital data base. Statistical data was obtained using the SPSS software version 22. Survival rate was calculated with the Kaplan-Meier method. Observation period took place between January 2016 and the end of June 2019. Results. The estimated median overall survival (OS) was 25.1 months (95% CI, 14.6%35.6) and the median progressionfree survival (PFS) was 10.7 months (95% CI, 5.9%15.4). Among all patients, 29 (21.0%) achieved complete response, 31 (22.5%) partial response and 23 (16.7%) reached stable disease. The number of organs with metastatic involvement and the level of baseline lactate dehydrogenase (LDH) concentration had significant influence on survival rates. Immune-related adverse events (irAE) were reported in 88 (63%) patients, while grade 3%4 irAE occurred in 12 (8.7%). Due to toxicity, 16 (11.6%) patients discontinued the treatment. Conclusions. Our real-world data from single centre retrospective analysis of treatment-naive metastatic melanoma patients treated with pembrolizumab showed inferior median OS and similar median PFS, compared to the results from clinical trials. However, patients with normal serum levels of LDH and a small number of organs with metastatic involvement had comparable survival outcomes. Toxicity rates of pembrolizumab were quite similar. These results further support the use of pembrolizumab for metastatic treatment-naive melanoma patients.
Keywords: immunotherapy, pembrolizumab, metastatic melanoma, treatment-naive
Published in DiRROS: 11.07.2024; Views: 292; Downloads: 143
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Abstract: Considering the role of phytoplankton in the functioning and health of marine systems, it is important to characterize its responses to a changing environment. The central Adriatic Sea, as a generally oligotrophic area, is a suitable environment to distinguish between regular fluctuations in phytoplankton and those caused by anthropogenic or climatic influences. This study provides a long-term perspective of phytoplankton assemblage in the central eastern Adriatic Sea, with 14 years of continuous time series data collected at two coastal and two offshore stations. The predominant phytoplankton groups were diatoms and phytoflagellates, but their proportion varied depending on the vicinity of the coast, as evidenced also by the distribution of chlorophyll a. In the coastal environment, the phytoplankton biomass was substantially higher, with a higher proportion of microphytoplankton, while small phytoplankton accounted for the majority of biomass in the offshore area. In addition, a decreasing trend in diatom abundance was observed in the coastal waters, while such trend was not so evident in the offshore area. Using a neural gas algorithm, five clusters were defined based on the contribution of the major groups. The observed increase in diversity, especially in dinoflagellates, which outnumber diatom taxa, could be a possible adaptation of dinoflagellates to the increased natural solar radiation in summer and the increased sea surface temperature.
Keywords: phytoplankton community, long-term data, diversity, chlorophyll a, neural gas analysis, solar radiation, Adriatic Sea
Published in DiRROS: 11.07.2024; Views: 301; Downloads: 237
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Abstract: An important aspect of geochemical studies is determining health hazard of potentially toxic elements (PTEs). Key information on PTEs behaviour in the human body in case of their ingestion is provided with the use of in vitro bioaccessibility tests. We analysed and compared oral bioaccessibility of a wide range of PTEs (As, Cd, Ce, Cr, Cu, Hg, La, Li, Ni, Pb, Sb, Sn, Zn), including some that are not often studied but might pose a human health hazard, in soil, attic dust, street dust, and household dust, using Unified BARGE Method (UBM). Additionally, feasibility of usage of scanning electron microscope techniques in analyses of solid residuals of UBM phases was tested. Results show that bioaccessible fractions (BAFs) of PTEs vary significantly between individual samples of the same medium, between different media and between the gastric and gastro-intestinal phases. In soil, attic dust and street dust, bioaccessibility of individual PTE is mostly higher in gastric than in gastro-intestinal phase. The opposite is true for PTEs in household dust. In all four media, with the exception of Pb in household dust, among the most bioaccessible PTEs in gastric phase are Cd, Cu, Pb, and Zn. During the transition from the stomach to small intestine, the mean BAFs of most elements in soil, attic dust, and street dust decreases. The most bioaccessible PTEs in gastro-intestinal phase are Cu, Cd, Ni, and As. Micromorphological and chemical characterisation at individual particle level before and after bioaccessibility test contribute significantly to the understanding of oral bioaccessibility.
Keywords: urban geochemistry, UBM, soil, attic dust, street dust, household dust
Published in DiRROS: 10.07.2024; Views: 286; Downloads: 118
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