Corneliu Vrancianu
Research Assistant - Danubius
Biography
Publications
| Publication | Authors | data | |
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article
Antimicrobial Resistance In Romania: Updates On Gram-Negative Escape Pathogens In The Clinical, Veterinary, And Aquatic Sectors |
Barbu Ilda Czobor; Gheorghe-Barbu Irina; Grigore Georgiana Alexandra; Vrancianu Corneliu Ovidiu; Chifiriuc Mariana Carmen | International Journal Of Molecular Sciences, 2023 | |
AbstractMultidrug-resistant Gram-negative bacteria such as Acinetobacter baumannii, Pseudomonas aeruginosa, and members of the Enterobacterales order are a challenging multi-sectorial and global threat, being listed by the WHO in the priority list of pathogens requiring the urgent discovery and development of therapeutic strategies. We present here an overview of the antibiotic resistance profiles and epidemiology of Gram-negative pathogens listed in the ESCAPE group circulating in Romania. The review starts with a discussion of the mechanisms and clinical significance of Gram-negative bacteria, the most frequent genetic determinants of resistance, and then summarizes and discusses the epidemiological studies reported for A. baumannii, P. aeruginosa, and Enterobacterales-resistant strains circulating in Romania, both in hospital and veterinary settings and mirrored in the aquatic environment. The Romanian landscape of Gram-negative pathogens included in the ESCAPE list reveals that all significant, clinically relevant, globally spread antibiotic resistance genes and carrying platforms are well established in different geographical areas of Romania and have already been disseminated beyond clinical settings. |
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article
The Vermiform Appendix And Its Pathologies |
Constantin Marian; Petrescu Livia; Matanie Cristina; Vrancianu Corneliu Ovidiu; Niculescu Adelina-Gabriela; Andronic Octavian; Bolocan Alexandra | Cancers, 2023 | |
AbstractSimple Summary Despite its small size, the vermiform appendix is an organ with several physiological roles and various pathologies, the most common of which is acute appendicitis. The other pathologies of the vermiform appendix, especially its neoplasia are rare and often go unnoticed and are accidentally identified during appendectomies performed for other reasons. In the early stages, most appendiceal neoplasms are not detected; however, in the advanced stages, they may mimic the symptoms of acute appendicitis. In addition, due to massive mucus production, mucinous neoplasms, especially adenocarcinomas, may fistulize into adjacent structures, some identified after perforated organ pathology. The general treatment for appendiceal pathologies, including neoplasms, is complete surgical excision of the appendix, with or without the right hemicolectomy. Life expectancy is somewhat longer for low-grade mucinous tumors and peaks for well-differentiated, small, metastasis-free neuroendocrine tumors of the appendix occurring in children. The vermiform appendix is a muscular cylindrical structure originating near the junction of the cecum and ileum, averaging 9 cm (5-35 cm) in size. As the most mobile viscera, it can adopt several positions, the most common being the retrocecal position. Perceived as an atavistic organ lacking physiological relevance, the vermiform appendix appears to be involved in immune function, serving in the maturation of B lymphocytes and the production of immunoglobulin A, in endocrine function, excreting amines and hormones in the 2-3 mL of mucus secreted daily, and in digestive function, by storing beneficial bacteria from where they can recolonize the colon. With a lumen of about 6 mm, the vermiform appendix has a reduced storage capacity, so any blockage of the appendix with fecoliths (fecaliths), seeds derailed from the colon, or enlarged lymph nodes prevents drainage and intraluminal accumulation of secreted mucus. Unable to relax, the appendix wall severely limits its intraluminal volume, so mucus accumulation leads to inflammation of the appendix, known generically as appendicitis. In addition, the vermiform appendix may be the site of the development of neoplastic processes, which may or may not involve mucus production, some of which can significantly affect the standard of living and ultimately lead to death. In general, mucinous tumors may have a better prognosis than non-mucinous tumors. This review takes a comprehensive path, starting by describing the anatomy and embryology of the vermiform appendix and further detailing its inflammatory pathologies, pathologies related to congenital anomalies, and appendix tumors, thus creating an up-to-date framework for better understanding, diagnosis, and treatment of these health problems. |
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article
Landscape Of Genetic Mutations In Appendiceal Cancers |
Constantin Marian; Matanie Cristina; Petrescu Livia; Bolocan Alexandra; Andronic Octavian; Bleotu Coralia; Mitache Mihaela Magdalena; Tudorache Sorin; Vrancianu Corneliu Ovidiu | Cancers, 2023 | |
AbstractSimple Summary An analysis of the presence of mutations of 105 genes in appendiceal cancers through the lens of the reviewed literature supports the view that in most of them, the inactivation of tumor suppressor genes, such as TP53 and SMAD4, is required in parallel with the reactivation of genes with oncogenic potentials, such as KRAS, GNAS, and BRAF, which support the main tumor processes, cell proliferation, angiogenesis, and evasion of apoptosis. Of all appendiceal cancers, the most mutated genes are reported in mucinous neoplasms of the appendix, not including those in the RAS-RAF-MEK-ERK signaling pathway, followed by low-grade appendiceal mucinous neoplasms, appendiceal goblet cell adenocarcinomas, and mucinous adenocarcinomas of the appendix, in which this signaling pathway is most frequently affected, showing its importance in their tumorigenesis. Microsatellite instability rarely occurs in appendix cancers, being reported only in adenocarcinomas. In appendiceal cancers, the most frequently mutated genes are (i) KRAS, which, when reactivated, restores signal transduction via the RAS-RAF-MEK-ERK signaling pathway and stimulates cell proliferation in the early stages of tumor transformation, and then angiogenesis; (ii) TP53, whose inactivation leads to the inhibition of programmed cell death; (iii) GNAS, which, when reactivated, links the cAMP pathway to the RAS-RAF-MEK-ERK signaling pathway, stimulating cell proliferation and angiogenesis; (iv) SMAD4, exhibiting typical tumor-suppressive activity, blocking the transmission of oncogenic TGFB signals via the SMAD2/SMAD3 heterodimer; and (v) BRAF, which is part of the RAS-RAF-MEK-ERK signaling pathway. Diverse mutations are reported in other genes, which are part of secondary or less critical signaling pathways for tumor progression, but which amplify the phenotypic diversity of appendiceal cancers. In this review, we will present the main genetic mutations involved in appendix tumors and their roles in cell proliferation and survival, and in tumor invasiveness, angiogenesis, and acquired resistance to anti-growth signals. |
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article
Targeting Plasmids To Limit Acquisition And Transmission Of Antimicrobial Resistance |
Vrancianu Corneliu Ovidiu; Popa Laura Ioana; Bleotu Coralia; Chifiriuc Mariana Carmen | Frontiers In Microbiology, 2020 | |
AbstractAntimicrobial resistance (AMR) is a significant global threat to both public health and the environment. The emergence and expansion of AMR is sustained by the enormous diversity and mobility of antimicrobial resistance genes (ARGs). Different mechanisms of horizontal gene transfer (HGT), including conjugation, transduction, and transformation, have facilitated the accumulation and dissemination of ARGs in Gram-negative and Gram-positive bacteria. This has resulted in the development of multidrug resistance in some bacteria. The most clinically significant ARGs are usually located on different mobile genetic elements (MGEs) that can move intracellularly (between the bacterial chromosome and plasmids) or intercellularly (within the same species or between different species or genera). Resistance plasmids play a central role both in HGT and as support elements for other MGEs, in which ARGs are assembled by transposition and recombination mechanisms. Considering the crucial role of MGEs in the acquisition and transmission of ARGs, a potential strategy to control AMR is to eliminate MGEs. This review discusses current progress on the development of chemical and biological approaches for the elimination of ARG carriers. |
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