ObjectivesDysbiosis of intestinal microbiota has been implicated in ulcerative colitis (UC). Fucosyltransferase (FUT) 2 and FUT3 determine expression of histo-blood group antigens in the gut and may affect the intestinal microbiota. We investigated the association between FUT2 and FUT3 polymorphisms and UC in Chinese patients.MethodsWe genotyped FUT2 (rs281377, rs1047781 and rs601338) and FUT3 (rs28362459, rs3745635 and rs3894326) in 485 UC patients and 580 healthy controls using SNaPshot. We also evaluated expression of Lewis a and b antigens in the sigmoid colon of 7 UC patients and 7 patients with benign colonic polyps.ResultsThe frequencies of mutant allele (A) and genotype (GA+AA) in FUT3 (rs3745635) were higher in UC patients than controls (P = 0.016, 95%CI: 1.339–1.699; P = 0.038, 95%CI: 1.330–1.742, respectively). Stratified analyses revealed that the frequencies of mutant allele (G) and genotype (TG+GG) of FUT3 (rs28362459) were significantly lower in patients with extensive colitis than those with distal colitis (P<0.001, 95%CI: 0.503–0.742; P = 0.001, 95%CI: 0.567–0.786, respectively). Similar conclusions were drawn for the mutant allele (A) and genotype (GA+AA) of FUT3 (rs3745635) in patients with extensive colitis compared to those with distal colitis (P = 0.006, 95%CI: 0.553–0.845; P = 0.011, 95%CI: 0.621–0.900, respectively). Although expression of Lewis b antigen in the sigmoid colon did not differ between UC patients and controls, Lewis a antigen expression was higher in the cryptic epithelium of both inflammatory and non-inflammatory sigmoid colon of UC patients than controls (P = 0.028).ConclusionsOur findings indicated that polymorphisms in FUT3 and its intestinal expression might be associated with UC pathogenesis.
Rendezvous is a fundamental process in constructing Cognitive Radio Networks (CRNs), through which the user can communicate with its neighbors by establishing a link on some licensed frequency band (channel). Most of the existing elegant rendezvous algorithms assume each user is equipped with a single radio. Nowadays the multi-radio cognitive radio architecture, where each user can access k ≥ 2 channels at the same time, has become a reality. In this paper, we study the rendezvous problem in multi-radio CRN to see whether and to what extent the multi-radio capability can improve the rendezvous performance. To begin with, we propose a family of deterministic distributed algorithms for two special situations when k = 2 and k = O( √ n), where n is the number of all channels. These algorithms show that the maximum time to rendezvous (MT T R) can be reduced (largely) in multi-radio CRN. Then we derive a lower bound of MT T R as Ω() for arbitrary k (Vi, Vj represents two users' available channel sets) and present a distributed algorithm to guarantee rendezvous in O() time slots, which meets the lower bound. Extensive simulations are conducted to corroborate our theoretical analyses.
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