Current Issue : April - June Volume : 2019 Issue Number : 2 Articles : 6 Articles
Background: The widespread Escherichia coli clone ST131 implicated in multidrug-resistant infections has been\nrecently reported, the majority belonging to O25:H4 serotype and classified into five main virotypes in accordance\nwith the virulence genes carried.\nMethods: Pathogenicity Islands I and II (PAI-I and PAI-II) were determined using conventional PCR protocols from a\nset of four E. coli CTXR ST131 O25:H4/H30-Rx strains collected from healthy donorsâ?? stool. The virulence genes patterns\nwere also analyzed and compared them with the virotypes reported previously; then adherence, invasion,\nmacrophage survival and biofilm formation assays were evaluated and AIEC pathotype genetic determinants were\ninvestigated.\nFindings: Non-reported virulence patterns were found in our isolates, two of them carried satA, papA, papGII genes\nand the two-remaining isolates carried cnfI, iroN, satA, papA, papGII genes, and none of them belonged to classical\nST131 virotypes, suggesting an endemic distribution of virulence genes and two new virotypes. The presence of PAI-I\nand PAI-II of Uropathogenic E. coli was determined in three of the four strains, furthermore adherence and invasion\nassays demonstrated higher degrees of attachment/invasion compared with the control strains. We also amplified\nintI1, insA and insB genes in all four samples.\nInterpretation: The results indicate that these strains own non-reported virotypes suggesting endemic distribution\nof virulence genes, our four strains also belong to an AIEC pathotype, being this the first report of AIEC in Mexico and\nthe association of AIEC with healthy donors....
Background: Drug resistance in Mycobacterium tuberculosis (MTB) is a major health issue worldwide. Recently,\nnext-generation sequencing (NGS) technology has begun to be used to detect resistance genes of MTB. We aimed\nto assess the clinical usefulness of Ion S5 NGS TB research panel for detecting MTB resistance in Korean tuberculosis\npatients.\nMethods: Mycobacterium tuberculosis with various drug resistance profiles including susceptible strains (N = 36)\nwere isolated from clinical specimens. Nucleic acids were extracted from inactivated culture medium and underwent\namplicon-based NGS to detect resistance variants in eight genes (gyrA, rpoB, pncA, katG, eis, rpsL, embB, and inhA).\nData from previous studies using the same panel were merged to yield pooled sensitivity and specificity values for\ndetecting drug resistance compared to phenotype-based methods.\nResults: The sequencing reactions were successful for all samples. A total of 24 variants were considered to be\nrelated to resistance, and 6 of them were novel. Agreement between the phenotypic and genotypic results was excellent\nfor isoniazid, rifampicin, and ethambutol, and was poor for streptomycin, amikacin, and kanamycin. The negative\npredictive values were greater than 97% for all drug classes, while the positive predictive values varied (44% to 100%).\nThere was a possibility that common mutations could not be detected owing to the low coverage.\nConclusions: We successfully applied NGS for genetic analysis of drug resistances in MTB, as well as for susceptible\nstrains. We obtained lists of polymorphisms and possible polymorphisms, which could be used as a guide for future\ntests applying NGS in mycobacteriology laboratories. When analyzing the results of NGS, coverage analysis of each\nsamples for each gene and benign polymorphisms not related to drug resistance should be considered....
Background: HER2 (ERBB2 or HER2/neu) is a tyrosine-kinase increasing cell proliferation. Overexpression/\namplification of HER2 is correlated with worse prognosis in solid malignancies. Consequently, HER2 targeting is\nestablished in breast and upper gastrointestinal tract cancer. There are conflicting data concerning the impact of\nHER2 overexpression on esophageal adenocarcinoma (EAC), as most studies do not differ between cancers of the\nesophagus/gastroesophageal junction and the stomach. The aim of this study was to analyze the expression/\namplification of HER2 in EAC in correlation to clinicopathological data to verify its prognostic impact.\nMethods: We analyzed 428 EAC patients that underwent transthoracic thoraco-abdominal esophagectomy\nbetween 1997 and 2014. We performed HER2 immunohistochemistry (IHC) according to the guidelines and\nfluorescence-in-situ-hybridization (FISH) for IHC score2+, using tissue micro arrays (TMA) with up to eight biopsies\nfrom the surface and infiltration area of a single tumor for evaluating HER2-heterogeneity and single-spot TMA. The\nHER2-status was correlated with clinicopathological data.\nResults: HER2-positivity was found in up to 14.9% in our cohort (IHC score 3+ or IHC score 2+ with gene\namplification) and demonstrated a significantly better overall survival (OS) in correlation to HER2-negative tumors\n(median OS 70.1 vs. 24.6 months, p = 0.006). HER2-overexpression was more frequently seen in lower tumor stages\n(pT1/pT2, p = 0.038), in the absence of lymphatic metastases (pN0/pN+, p = 0.020), and was significantly associated\nwith better histological grading (G1/G2) (p = 0.041).\nConclusion: We demonstrated a positive prognostic impact of HER2 overexpression in a large cohort of EAC,\ncontrary to other solid malignancies including gastric cancer and breast cancer, but consistent to the results of a\nlarge study on EAC from 2012....
Background: Glioma is the most prevalent malignant tumor in human central nervous systems. Recently, the\ndevelopment of resistance to radiotherapy in glioma patients markedly vitiates the therapy outcome. MiR-153-3p has\nbeen reported to be closely correlated with tumor progression, but its effect and molecular mechanism underlying\nradioresistance remains unclear in glioma.\nMethods: The expression of miR-153-3p was determined in radioresistant glioma clinical specimens as well as\nglioma cell lines exposed to irradiation (IR) using quantitative real-time PCR. Cell viability, proliferation and apoptosis\nwere then evaluated by MTT assay, colony formation assay, Flow cytometry analysis and caspase-3 activity assay in\nglioma cells (U87 and U251). Tumor forming was evaluated by nude mice model in vivo. TUNEL staining was used to\ndetect cell apoptosis in nude mice model. The target genes of miR-153-3p were predicted and validated using integrated\nbioinformatics analysis and a luciferase reporter assay.\nResults: Here, we found that miR-153-3p was down-regulated in radioresistant glioma clinical specimens as well as\nglioma cell lines (U87 and U251) exposed to IR. Enhanced expression of miR-153-3p promoted the radiosensitivity,\npromoted apoptosis and elevated caspase-3 activity in glioma cells in vitro, as well as the radiosensitivity in U251 cell\nmouse xenografs in vivo. Mechanically, B cell lymphoma-2 gene (BCL2) was identified as the direct and functional\ntarget of miR-153-3p. Moreover, restoration of BCL2 expression reversed miR-153-3p-induced increase of radiosensitivity,\napoptosis and caspase-3 activity in U251 cells in vitro. In addition, clinical data indicated that the expression of\nmiR-153-3p was significantly negatively associated with BCL2 in radioresistance of glioma samples.\nConclusions: Our findings suggest that miR-153-3p is a potential target to enhance the effect of radiosensitivity on\nglioma cells, thus representing a new potential therapeutic target for glioma....
--NA--...
Background: In patients with myelodysplastic syndrome (MDS), bone marrow cells have an increased\npredisposition to apoptosis, yet MDS cells outcompete normal bone marrow (BM)-- suggesting that factors\nregulating growth potential may be important in MDS. We previously identified v-Erb A related-2 (EAR-2, NR2F6) as\na gene involved in control of growth ability.\nMethods: Bone marrow obtained from C57BL/6 mice was transfected with a retrovirus containing EAR-2-IRES-GFP.\nEx vivo transduced cells were flow sorted. In some experiments cells were cultured in vitro, in other experiments\ncells were injected into lethally irradiated recipients, along with non-transduced bone marrow cells. Short-hairpin\nRNA silencing EAR-2 was also introduced into bone marrow cells cultured ex vivo.\nResults: Here, we show that EAR-2 inhibits maturation of normal BM in vitro and in vivo and that EAR-2 transplant\nchimeras demonstrate key features of MDS. Competitive repopulation of lethally irradiated murine hosts with EAR-\n2-transduced BM cells resulted in increased engraftment and increased colony formation in serial replating\nexperiments. Recipients of EAR-2-transduced grafts had hypercellular BM, erythroid dysplasia, abnormal localization\nof immature precursors and increased blasts; secondary transplantation resulted in acute leukemia. Animals were\ncytopenic, having reduced numbers of erythrocytes, monocytes and granulocytes. Suspension culture confirmed\nthat EAR-2 inhibits granulocytic and monocytic differentiation, while knockdown induced granulocytic\ndifferentiation. We observed a reduction in the number of BFU-E and CFU-GM colonies and the size of erythroid\nand myeloid colonies. Serial replating of transduced hematopoietic colonies revealed extended replating potential\nin EAR-2-overexpressing BM, while knockdown reduced re-plating ability. EAR-2 functions by recruitment of histone\ndeacetylases, and inhibition of differentiation in 32D cells is dependent on the DNA binding domain.\nConclusions: This data suggest that NR2F6 inhibits maturation of normal BM in vitro and in vivo and that the\nNR2F6 transplant chimera system demonstrates key features of MDS, and could provide a mouse model for MDS....
Loading....