417 research outputs found

    PuFFIN--a parameter-free method to build nucleosome maps from paired-end reads.

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    BackgroundWe introduce a novel method, called PuFFIN, that takes advantage of paired-end short reads to build genome-wide nucleosome maps with larger numbers of detected nucleosomes and higher accuracy than existing tools. In contrast to other approaches that require users to optimize several parameters according to their data (e.g., the maximum allowed nucleosome overlap or legal ranges for the fragment sizes) our algorithm can accurately determine a genome-wide set of non-overlapping nucleosomes without any user-defined parameter. This feature makes PuFFIN significantly easier to use and prevents users from choosing the "wrong" parameters and obtain sub-optimal nucleosome maps.ResultsPuFFIN builds genome-wide nucleosome maps using a multi-scale (or multi-resolution) approach. Our algorithm relies on a set of nucleosome "landscape" functions at different resolution levels: each function represents the likelihood of each genomic location to be occupied by a nucleosome for a particular value of the smoothing parameter. After a set of candidate nucleosomes is computed for each function, PuFFIN produces a consensus set that satisfies non-overlapping constraints and maximizes the number of nucleosomes.ConclusionsWe report comprehensive experimental results that compares PuFFIN with recently published tools (NOrMAL, TEMPLATE FILTERING, and NucPosSimulator) on several synthetic datasets as well as real data for S. cerevisiae and P. falciparum. Experimental results show that our approach produces more accurate nucleosome maps with a higher number of non-overlapping nucleosomes than other tools

    Analysis of nucleosome positioning landscapes enables gene discovery in the human malaria parasite Plasmodium falciparum.

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    BackgroundPlasmodium falciparum, the deadliest malaria-causing parasite, has an extremely AT-rich (80.7 %) genome. Because of high AT-content, sequence-based annotation of genes and functional elements remains challenging. In order to better understand the regulatory network controlling gene expression in the parasite, a more complete genome annotation as well as analysis tools adapted for AT-rich genomes are needed. Recent studies on genome-wide nucleosome positioning in eukaryotes have shown that nucleosome landscapes exhibit regular characteristic patterns at the 5'- and 3'-end of protein and non-protein coding genes. In addition, nucleosome depleted regions can be found near transcription start sites. These unique nucleosome landscape patterns may be exploited for the identification of novel genes. In this paper, we propose a computational approach to discover novel putative genes based exclusively on nucleosome positioning data in the AT-rich genome of P. falciparum.ResultsUsing binary classifiers trained on nucleosome landscapes at the gene boundaries from two independent nucleosome positioning data sets, we were able to detect a total of 231 regions containing putative genes in the genome of Plasmodium falciparum, of which 67 highly confident genes were found in both data sets. Eighty-eight of these 231 newly predicted genes exhibited transcription signal in RNA-Seq data, indicative of active transcription. In addition, 20 out of 21 selected gene candidates were further validated by RT-PCR, and 28 out of the 231 genes showed significant matches using BLASTN against an expressed sequence tag (EST) database. Furthermore, 108 (47%) out of the 231 putative novel genes overlapped with previously identified but unannotated long non-coding RNAs. Collectively, these results provide experimental validation for 163 predicted genes (70.6%). Finally, 73 out of 231 genes were found to be potentially translated based on their signal in polysome-associated RNA-Seq representing transcripts that are actively being translated.ConclusionOur results clearly indicate that nucleosome positioning data contains sufficient information for novel gene discovery. As distinct nucleosome landscapes around genes are found in many other eukaryotic organisms, this methodology could be used to characterize the transcriptome of any organism, especially when coupled with other DNA-based gene finding and experimental methods (e.g., RNA-Seq)

    Trans-nasal endoscopic and intra-oral combined approach for odontogenic cysts

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    Maxillary cysts are a common finding in maxillofacial surgery, dentistry and otolaryngology. Treatment is surgical; a traditional approach includes Caldwell-Luc and other intra-oral approaches. In this article, we analyse the outcomes of 9 patients operated on using a combined intra-oral and trans-nasal approach to the aforementioned disease. Although the number of patients is small, the good results of this study suggest that the combined approach might be a reliable treatment option

    DNA-encoded nucleosome occupancy is associated with transcription levels in the human malaria parasite Plasmodium falciparum.

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    BackgroundIn eukaryotic organisms, packaging of DNA into nucleosomes controls gene expression by regulating access of the promoter to transcription factors. The human malaria parasite Plasmodium falciparum encodes relatively few transcription factors, while extensive nucleosome remodeling occurs during its replicative cycle in red blood cells. These observations point towards an important role of the nucleosome landscape in regulating gene expression. However, the relation between nucleosome positioning and transcriptional activity has thus far not been explored in detail in the parasite.ResultsHere, we analyzed nucleosome positioning in the asexual and sexual stages of the parasite's erythrocytic cycle using chromatin immunoprecipitation of MNase-digested chromatin, followed by next-generation sequencing. We observed a relatively open chromatin structure at the trophozoite and gametocyte stages, consistent with high levels of transcriptional activity in these stages. Nucleosome occupancy of genes and promoter regions were subsequently compared to steady-state mRNA expression levels. Transcript abundance showed a strong inverse correlation with nucleosome occupancy levels in promoter regions. In addition, AT-repeat sequences were strongly unfavorable for nucleosome binding in P. falciparum, and were overrepresented in promoters of highly expressed genes.ConclusionsThe connection between chromatin structure and gene expression in P. falciparum shares similarities with other eukaryotes. However, the remarkable nucleosome dynamics during the erythrocytic stages and the absence of a large variety of transcription factors may indicate that nucleosome binding and remodeling are critical regulators of transcript levels. Moreover, the strong dependency between chromatin structure and DNA sequence suggests that the P. falciparum genome may have been shaped by nucleosome binding preferences. Nucleosome remodeling mechanisms in this deadly parasite could thus provide potent novel anti-malarial targets

    Emetogenicity of Antibody-Drug Conjugates (ADCs) in Solid Tumors with a Focus on Trastuzumab Deruxtecan: Insights from an Italian Expert Panel

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    In the past decade, nine antibody-drug conjugates (ADCs) have been approved for the treatment of various tumors, four of which specifically for solid malignancies. ADCs deliver the cytotoxic payload to the cancer site, thereby improving chemotherapy efficacy while reducing systemic drug exposure and toxicity. With their high selectivity, ADCs are associated with a manageable side-effect profile, with nausea and vomiting being among the most frequent toxicities, although this may vary according to the respective ADC and the associated payload. Information about the emetic risk of the new ADC compounds is limited. Three virtual focus groups of Italian oncologists were held to raise awareness on the importance of an antiemetic prophylaxis regimen to prevent and mitigate ADC-associated emesis and its sequelae. After reviewing published evidence and guidelines, the three expert panels shared their experience on the early use of ADCs gained through the participation in specific clinical trials and their clinical practice. The following issues were discussed: antiemetic therapy during trastuzumab deruxtecan treatment, with a protocol adopted at the San Raffaele Hospital (Milan, Italy); the use of steroids; the management of anticipatory nausea during trastuzumab deruxtecan therapy; nutritional counselling; and effective doctor\u2013patient communication. The experts acknowledged that recommendations should be drug-specific, and formulated opinion-based advice intended to guide physicians in their daily practice until further evidence emerges

    Autologous micro-fragmented adipose tissue for the treatment of diabetic foot minor amputations: A randomized controlled single-center clinical trial (MiFrAADiF)

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    Background: The diabetic foot ulcer (DFU) is one of the most prevalent complications of diabetes mellitus and often develops severe effects that can lead to amputation. A non-healing "minor" amputation often precedes a major amputation resulting in a negative impact on the function and quality of life of the patients. Stem cell-based therapies have emerged as a promising option to improve healing, and the adipose tissue is an abundant and easy to access source. The injection of autologous micro-fragmented adipose tissue at the amputation stump of a diabetic population undergoing a lower limb minor amputation was evaluated and compared with the standard care. Methods: In this randomized controlled trial with two arms (parallel assignment) and no masking, 114 patients undergoing a lower limb minor amputation were randomized to standard of care or to micro-fragmented adipose tissue injection prepared using a minimal manipulation technique (Lipogems®) in a closed system. Clinical outcomes were determined monthly up to 6 months. Primary endpoint of the study was the evaluation of the healing rate and time after the minor amputation. Secondary endpoints included the assessment of safety, feasibility, technical success, relapse rate, skin tropism, and intensity of pain. Results: At 6 months, 80% of the micro-fragmented adipose tissue-treated feet healed and 20% failed as compared with the control group where 46% healed and 54% failed (p = 0.0064). No treatment-related adverse events nor relapses were documented, and technical success was achieved in all cases. The skin tropism was improved in the treatment group, and the pain scale did not differ between the two groups. Conclusion: The results of this randomized controlled trial suggest that the local injection of autologous micro-fragmented adipose tissue is a safe and valid therapeutic option able to improve healing rate following minor amputations of irreversible DFU. The technique overcomes several stem cell therapy-related criticisms and its potential in wound care should be better evaluated and the therapeutic indications could be expanded. Trial registration: ClinicalTrials.gov number: NCT03276312. Date of registration: September 8, 2017 (retrospectively registered)

    Primary tumor sidedness and benefit from FOLFOXIRI plus bevacizumab as initial therapy for metastatic colorectal cancer. Retrospective analysis of the TRIBE trial by GONO

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    Right-sided metastatic colorectal cancer (mCRC) patients have poor prognosis and achieve limited benefit from first-line doublets plus a targeted agent. In this unplanned analysis of the TRIBE study, we investigated the prognostic and predictive impact of primary tumor sidedness in mCRC patients and the differential impact of the intensification of the chemotherapy in subgroups defined according to both primary tumor sidedness and RAS and BRAF mutational status

    Trans-nasal endoscopic and intra-oral combined approach for odontogenic cysts

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    Maxillary cysts are a common finding in maxillofacial surgery, dentistry and otolaryngology. Treatment is surgical; a traditional approach includes Caldwell-Luc and other intra-oral approaches. In this article, we analyse the outcomes of 9 patients operated on using a combined intra-oral and trans-nasal approach to the aforementioned disease. Although the number of patients is small, the good results of this study suggest that the combined approach might be a reliable treatment option

    Mode Coupling Analysis of Hollow Ring-Core Fibers for OAM Transmission

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    We present an analytical and numerical description of coupling between OAM modes in hollow ring-core fibers affected by stress birefringence and ellipticity The analysis paves the way to a better modeling of propagation in these fibers

    A 10-year experience in preoperative ultrasound imaging for parotid glands’ benign neoformations

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    Salivary gland neoplasms represent less than 4% of all head and neck lesions, being 80% in the parotid gland and usually benign. Imaging plays a key role in the evaluation of parotid gland masses. Ultrasound is cheap, with an excellent resolution and a safe real time assessment making it an ideal first evaluation option. Conversely, MRI is considered a second-line pre-surgery exam used to determine the location, the extension and the signal features of a parotid lesion. Both US and MRI are poorly reliable for predicting histology, therefore a fine-needle aspiration cytology (FNAC) is usually needed. In our retrospective study, we examined 263 patients with parotid diseases and a FNAC positive for a benign neoplasm, who underwent surgery between 2010 and 2020, in the departments of Otorhinolaryngology and Maxillofacial surgery in Verona. We compared a group of 126 patients preoperatively evaluated with ultrasound and a control group of 137 patients studied through third level imaging (usually MRI). In our case series, both third level imaging and US were used in equal measure, despite the lesion size. We found the recurrence rate to be almost the same between the two diagnostic methods and we saw that the patients studied through third level preoperative imaging had a higher complication rate and a worse facial nerve outcome. In our opinion, for patients with a FNAC positive for benign lesion the exclusive use of ultrasound imaging provides enough information to study the neoplasm while allowing for a faster and cheaper preoperative evaluation
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