1,133 research outputs found

    Molecular evidence of incipient speciation within Anopheles gambiae s.s. in West Africa

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    We karyotyped and identified by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis Anopheles gambiae s.s. samples collected in several African countries. The data show the existence of two non-panmictic molecular forms, named S and M, whose distribution extended from forest to savannahs, Mosquitoes of the S and M forms are homosequential standard for chromosome-2 inversions in forest areas. In dry savannahs, S is characterized mainly by inversion polymorphisms typical of Savanna and Bamako chromosomal forms, while M shows chromosome-2 arrangements typical of Mopti and/or Savanna and/or Bissau, depending on its geographical origin. Chromosome-2 inversions therefore seem to be involved in ecotypic adaptation rather than in mate-recognition systems. Strong support for the reproductive isolation of S and M in Ivory Coast comes from the observation that the kdr allele is found at high frequencies in S specimens and not at all in chromosomal identical M specimens. However, the kdr allele does not segregate with molecular forms in Benin

    RCC1L (WBSCR16) isoforms coordinate mitochondrial ribosome assembly through their interaction with GTPases

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    Mitochondrial translation defects can be due to mutations affecting mitochondrial-or nuclear-encoded components. The number of known nuclear genes involved in mitochondrial translation has significantly increased in the past years. RCC1L (WBSCR16), a putative GDP/GTP exchange factor, has recently been described to interact with the mitochondrial large ribosomal subunit. In humans, three different RCC1L isoforms have been identified that originate from alternative splicing but share the same N-Terminus, RCC1LV1, RCC1LV2 and RCC1LV3. All three isoforms were exclusively localized to mitochondria, interacted with its inner membrane and could associate with homopolymeric oligos to different extent. Mitochondrial immunoprecipitation experiments showed that RCC1LV1 and RCC1LV3 associated with the mitochondrial large and small ribosomal subunit, respectively, while no significant association was observed for RCC1LV2. Overexpression and silencing of RCC1LV1 or RCC1LV3 led to mitoribosome biogenesis defects that resulted in decreased translation. Indeed, significant changes in steady-state levels and distribution on isokinetic sucrose gradients were detected not only for mitoribosome proteins but also for GTPases, (GTPBP10, ERAL1 and C4orf14), and pseudouridylation proteins, (TRUB2, RPUSD3 and RPUSD4). All in all, our data suggest that RCC1L is essential for mitochondrial function and that the coordination of at least two isoforms is essential for proper ribosomal assembly

    A new insight into MYC action: control of RNA polymerase II methylation and transcription termination

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    MYC oncoprotein deregulation is a common catastrophic event in human cancer and limiting its activity restrains tumor development and maintenance, as clearly shown via Omomyc, an MYC-interfering 90 amino acid mini-protein. MYC is a multifunctional transcription factor that regulates many aspects of transcription by RNA polymerase II (RNAPII), such as transcription activation, pause release, and elongation. MYC directly associates with Protein Arginine Methyltransferase 5 (PRMT5), a protein that methylates a variety of targets, including RNAPII at the arginine residue R1810 (R1810me2s), crucial for proper transcription termination and splicing of transcripts. Therefore, we asked whether MYC controls termination as well, by affecting R1810me2S. We show that MYC overexpression strongly increases R1810me2s, while Omomyc, an MYC shRNA, or a PRMT5 inhibitor and siRNA counteract this phenomenon. Omomyc also impairs Serine 2 phosphorylation in the RNAPII carboxyterminal domain, a modification that sustains transcription elongation. ChIP-seq experiments show that Omomyc replaces MYC and reshapes RNAPII distribution, increasing occupancy at promoter and termination sites. It is unclear how this may affect gene expression. Transcriptomic analysis shows that transcripts pivotal to key signaling pathways are both up- or down-regulated by Omomyc, whereas genes directly controlled by MYC and belonging to a specific signature are strongly down-regulated. Overall, our data point to an MYC/PRMT5/RNAPII axis that controls termination via RNAPII symmetrical dimethylation and contributes to rewiring the expression of genes altered by MYC overexpression in cancer cells. It remains to be clarified which role this may have in tumor development

    A Case of Osteonecrosis of the Jaw in a Patient with Crohn's Disease Treated with Infliximab

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    Background: Medication-related osteonecrosis of the jaw (MRONJ) is a severe adverse drug reaction, occurring in patients undergoing treatments with antiresorptive or antiangiogenic agents, such as bisphosphonates, denosumab, or bevacizumab, for different oncologic and non-oncologic diseases. The aim of this study was to report a case of MRONJ in a patient taking infliximab, an anti-TNF-alpha antibody used to treat Crohn's disease, rheumatoid arthritis, ulcerative colitis, ankylosing spondylitis, psoriatic arthritis, and plaque psoriasis. Case Report: A 49-year-old female patient affected by Crohn's disease, who had been undergoing 250 mg intravenous infliximab every six weeks for 12 years, with no history of antiresorptive or antiangiogenic agent administration, came to our attention for post-surgical MRONJ, associated with a wide cutaneous necrotic area of her anterior mandible. Following antibiotic cycles, the patient underwent surgical treatment with wide bone resection and debridement of necrotic tissues; after prolonged follow-up (16 months), the patient completely healed without signs of recurrence. Conclusions: Prevention of MRONJ by dental check-up before and during treatments with antiresorptive treatments (bisphosphonates or denosumab) is a well-established procedure. Although further studies are required to confirm the role of infliximab in MRONJ, based on the results of this study, we propose that patients who are going to be treated with infliximab should also undergo dental check-up before starting therapy, to possibly avoid MRONJ onset

    Bacterial Symbionts in Ceratitis capitata

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    Ceratitis capitata (Diptera: Tephritidae) is responsible for extensive damage in agriculture with important economic losses. Several strategies have been proposed to control this insect pest including insecticides and the Sterile Insect Technique. Traditional control methods should be implemented by innovative tools, among which those based on insect symbionts seem very promising. Our study aimed to investigate, through the 16S Miseq analysis, the microbial communities associated with selected organs in three different medfly populations to identify possible candidates to develop symbiont-based control approaches. Our results confirm that Klebsiella and Providencia are the dominant bacteria in guts, while a more diversified microbial community has been detected in reproductive organs. Concertedly, we revealed for the first time the presence of Chroococcidiopsis and Propionibacterium as stable components of the medfly's microbiota. Additionally, in the reproductive organs, we detected Asaia, a bacterium already proposed as a tool in the Symbiotic Control of Vector-Borne Diseases. A strain of Asaia, genetically modified to produce a green fluorescent protein, was used to ascertain the ability of Asaia to colonize specific organs of C. capitata. Our study lays the foundation for the development of control methods for C. capitata based on the use of symbiont bacteria

    Evidence-Based Dentistry: What's New?

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    The importance of evidence for every branch of medicine in teaching in order to orient the practitioners among the great amount of most actual scientific information's, and to support clinical decisions, is well established in health care, including dentistry

    Plasma technology increases the efficacy of prothioconazole against fusarium graminearum and fusarium proliferatum contamination of maize (Zea mays) seedlings

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    The contamination of maize by Fusarium species able to produce mycotoxins raises great concern worldwide since they can accumulate these toxic metabolites in field crop products. Further-more, little information exists today on the ability of Fusarium proliferatum and Fusarium graminearum, two well know mycotoxigenic species, to translocate from the seeds to the plants up to the kernels. Marketing seeds coated with fungicide molecules is a common practice; however, since there is a growing need for reducing chemicals in agriculture, new eco-friendly strategies are increasingly tested. Technologies based on ionized gases, known as plasmas, have been used for decades, with newer material surfaces, products, and approaches developed continuously. In this research, we tested a plasma-generated bilayer coating for encapsulating prothioconazole at the surface of maize seeds, to protect them from F. graminearum and F. proliferatum infection. A minimum amount of chemical was used, in direct contact with the seeds, with no dispersion in the soil. The ability of F. graminearum and F. proliferatum species to translocate from seeds to seedlings of maize has been clearly proven in our in vitro experiments. As for the use of plasma technology, the combined use of the plasma-generated coating with embedded prothioconazole was the most efficient approach, with a higher reduction of the infection of the maize seminal root system and stems. The debated capability of the two Fusarium species to translocate from seeds to seedlings has been demonstrated. The plasma-generated coating with embedded prothioconazole resulted in a promising sustainable approach for the protection of maize seedlings

    Dietary supplementation of garlic and rosemary: effects on colour stability and lipid oxidation in lamb meat

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    The colour of fresh meat is an important criterion consumers take into consideration when purchasing meat. Meat colour depends on the occurrence of chemical and microbial deterioration processes. The role of vitamin E and other antioxidants on ruminant meat colour stability and prevention of lipid oxidation has been widely investigated (Macit et al., 2003; Realini et al., 2004). Many natural herbs and plant extracts exert antioxidant effects such as garlic (Yin and Cheng, 2003) and rosemary (Sánchez-Escalante et al., 2001). Their use as additives for animal feeding may be a valid alternative to synthetic antioxidants since they show beneficial effects also on animal welfare and other physiological functions (Tedesco, 2001). The aim of this study was to evaluate whether garlic and rosemary dietary supplementation as compared with vitamin E affects lamb meat colour and lipid stability during storage
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