PubMed · 8607210
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
H J Kolmos, L P Nielsen. 1996-01-15. [Multiresistant pneumococci: status and perspectives].. https://pubmed.ncbi.nlm.nih.gov/8607210/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
BACKGROUND: Sequence variations in HR-1 gp41 env gene region encoding the target for T-20 have previously been reported among patients naive to inhibitory fusion. OBJECTIVE: To evaluate whether a previous therapeutic history of patients could have an impact on a differential evolution of the gp41 polymorphism. METHODS: We assessed the genetic polymorphism within the critical HR-1 gp41 env gene region in HIV-1 variants from 108 T-20-naive patients (Groups I-III) and 12 patients receiving T-20 as part of a salvage regimen (Group IV). T-20-naive patients included 50 patients exhibiting variants harboring resistance mutations to NRTIs, NNRTIs, and PIs (Group I), 24 patients with variants harboring resistance mutations for NRTIs and/or NNRTIs (Group II), and 34 antiretroviral drug-naive patients (Group III). RESULTS: In T-20-naive patients whose HIV harbored resistance mutations to NRTIs, NNRTIs, and/or PIs, the mean number of synonymous mutations (ds) per patient was decreased and the mean number of nonsynonymous (da) mutations per patient was increased, resulting in a significant decrease in the mean Sigmads/Sigmada ratio as compared with antiretroviral drug-naive patients (Group III; 4.1 vs. 11.6; P < 0.0001). The mean number of polymorphic mutations in HR-1 gp41 per patient was two-fold higher in patients exhibiting antiretroviral drug resistance mutations (Groups I and II) than in antiretroviral drug-naive patients (Group III; 0.41 vs. 0.20; P < 0.05). CONCLUSION: Our observations indicate that the HR-1 gp41 T-20 target is subjected to high genetic variability, including intrinsic polymorphism and selection of T-20 resistance mutations under T-20 intake, that is increased by the presence of resistance mutations to NRTIs, NNRTIs, and/or PIs. Our data provide a basis for a potential impact of previous antiretroviral drug history on the therapeutic efficacy of T-20.
It is becoming increasingly evident that single-locus effects cannot explain complex multifactorial human diseases like cancer. We applied the multi-factor dimensionality reduction (MDR) method to a large cohort study on gene-environment and gene-gene interactions. The study (case-control nested in the EPIC cohort) was established to investigate molecular changes and genetic susceptibility in relation to air pollution and environmental tobacco smoke (ETS) in non-smokers. We have analyzed 757 controls and 409 cases with bladder cancer (n=124), lung cancer (n=116) and myeloid leukemia (n=169). Thirty-six gene variants (DNA repair and metabolic genes) and three environmental exposure variables (measures of air pollution and ETS at home and at work) were analyzed. Interactions were assessed by prediction error percentage and cross-validation consistency (CVC) frequency. For lung cancer, the best model was given by a significant gene-environment association between the base excision repair (BER) XRCC1-Arg399Gln polymorphism, the double-strand break repair (DSBR) BRCA2-Asn372His polymorphism and the exposure variable 'distance from heavy traffic road', an indirect and robust indicator of air pollution (mean prediction error of 26%, P<0.001, mean CVC of 6.60, P=0.02). For bladder cancer, we found a significant 4-loci association between the BER APE1-Asp148Glu polymorphism, the DSBR RAD52-3'-untranslated region (3'-UTR) polymorphism and the metabolic gene polymorphisms COMT-Val158Met and MTHFR-677C>T (mean prediction error of 22%, P<0.001, mean CVC consistency of 7.40, P<0.037). For leukemia, a 3-loci model including RAD52-2259C>T, MnSOD-Ala9Val and CYP1A1-Ile462Val had a minimum prediction error of 31% (P<0.001) and a maximum CVC of 4.40 (P=0.086). The MDR method seems promising, because it provides a limited number of statistically stable interactions; however, the biological interpretation remains to be understood.
Gentamicin-susceptible methicillin-resistant Staphylococcus aureus (GS-MRSA) strains are replacing gentamicin-resistant MRSA (GR-MRSA) strains. We showed that exposure to other patients harboring GS-MRSA was the major risk factor for GS-MRSA acquisition, and that antimicrobial exposure, especially to beta-lactams, was strongly associated with acquisition of GR-MRSA but not GS-MRSA. Gentamicin use was significantly associated with GR-MRSA acquisition in univariate analysis only.