Objective To evaluate the role of spinal neuronal Mas-related gene receptor C (MrgC) in the maintenance of bone cancer pain (BCP) in mice.Methods A total of 132 SPF male C3H/HeJ mice, aged 8-10 weeks, weighing 18-22 g, were randomly divided into 4 groups (n=33 each) using a random number table: sham operation group (S group) , BCP group, bovine adrenal medulla peptide 8-22 (BAM8-22, a highly selective MrgC agonist) group (group BAM), and MrgC antibody group (group MA).BCP was produced by injecting α-MEM 20 μl containing 2×105NCTC2472 cells into the distal medullary cavity of right femur bone.While α-MEM 20 μl was injected only in group S.The artificial cerebrospinal fluid 5 μl was injected intrathecally in S and BCP groups, and BAM 8-22 8 nmol/5 μl and MrgC antibody 5 μl were injected intrathecally in BAM and MA groups, respectively, once a day for 7 consecutive days starting from the day 14 after inoculation of the tumor cells.At 1 day before inoculation (T0), before administration (T1) , and at 14, 16 19 and 21 days after inoculation (T2-5, at 0.5 h before the initial administration and 2 h after each administration) , the number of spontaneous flinches (NSF) and mechanical paw withdrawal threshold (MWT) were measured.Five animals selected from each group at each time point were sacrificed, and the lumbar enlargement segments of the spinal cord were removed for determination of MrgC expression in the spinal neurons (by immunofluorescence).Results Compared with group S, NSF was significantly increased, MWT was decreased, and the expression of MrgC was up-regulated at T1-5 in BCP, BAM and MA groups.Compared with group BCP, NSF was significantly decreased, MWT was increased, and the expression of MrgC was up-regulated at T2-5 in group BAM, and NSF was significantly increased, MWT was decreased, and the expression of MrgC was down-regulated at T2-5 in group MA.Conclusion Spinal neuronal MrgC is involved in the maintenance of BCP in mice.

Beijing has been one of the epicenters attacked most severely by the SARS-CoV (severe acute respiratory syndrome-associated coronavirus) since the first patient was diagnosed in one of the city's hospitals. We now report complete genome sequences of the BJ Group, including four isolates (Isolates BJ01, BJ02, BJ03, and BJ04) of the SARS-CoV. It is remarkable that all members of the BJ Group share a common haplotype, consisting of seven loci that differentiate the group from other isolates published to date. Among 42 substitutions uniquely identified from the BJ group, 32 are non-synonymous changes at the amino acid level. Rooted phylogenetic trees, proposed on the basis of haplotypes and other sequence variations of SARS-CoV isolates from Canada, USA, Singapore, and China, gave rise to different paradigms but positioned the BJ Group, together with the newly discovered GD01 (GD-Ins29) in the same clade, followed by the H-U Group (from Hong Kong to USA) and the H-T Group (from Hong Kong to Toronto), leaving the SP Group (Singapore) more distant. This result appears to suggest a possible transmission path from Guangdong to Beijing/Hong Kong, then to other countries and regions.
Genome, Viral ; Haplotypes ; Humans ; Mutation ; Open Reading Frames ; Phylogeny ; SARS Virus ; genetics