Phylogenetic and Evolutionary Comparison of Mitogenomes Reveal Adaptive Radiation of Lampriform Fishes.

Lampriform fishes (Lampriformes), which primarily inhabit deep-sea environments, are large marine fishes varying from the whole-body endothermic opah to the world's longest bony fish-giant oarfish, with species morphologies varying from long and thin to deep and compressed, making them an ideal model for studying the adaptive radiation of teleost fishes. Moreover, this group is important from a phylogenetic perspective owing to their ancient origins among teleosts. However, knowledge about the group is limited, which is, at least partially, due to the dearth of recorded molecular data. This study is the first to analyze the mitochondrial genomes of three lampriform species (Lampris incognitus, Trachipterus ishikawae, and Regalecus russelii) and infer a time-calibrated phylogeny, including 68 species among 29 orders. Our phylomitogenomic analyses support the classification of Lampriformes as monophyletic and sister to Acanthopterygii; hence, addressing the longstanding controversy regarding the phylogenetic status of Lampriformes among teleosts. Comparative mitogenomic analyses indicate that tRNA losses existed in at least five Lampriformes species, which may reveal the mitogenomic structure variation associated with adaptive radiation. However, codon usage in Lampriformes did not change significantly, and it is hypothesized that the nucleus transported the corresponding tRNA, which led to function substitutions. The positive selection analysis revealed that atp8 and cox3 were positively selected in opah, which might have co-evolved with the endothermic trait. This study provides important insights into the systematic taxonomy and adaptive evolution studies of Lampriformes species.

[UPLC/Q-TOF-MS(E) based analysis of chemical composition of banxia xiexin decoction].

In order to clarify the chemical composition and source of Banxia Xiexin decoction quickly and comprehensively, whole and individual herbs of Banxia Xiexin decoction were analyzed by ultra-performance liquid chromatography with quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF-MS(E)). Under identical experiment conditions, chromatography results were compared between experiment groups. Based on the Q-TOF-MS(E) analysis, 74 peaks were identified on line. The herbal sources of these peaks were assigned. The results implied that flavonoids, triterpenoid saponins, alkaloids and glycosides were the main components in effective part of Banxia Xiexin decoction. The method established is simple and rapid for elucidation the constituents of Banxia Xiexin decoction and the results could be used for the quality control of Banxia Xiexin decoction.

[Cloning of human uracil N-glycosylase and its detection in cancer tissues by quantitative RT-PCR].

The uracil in DNA comes from either the misincorporation of dUTP in place of dTTP or deamination of cytosine. In the latter case, it can result in a GC to AT transition mutation if the uracil is not removed before DNA replication. Base excision repair (BER) is a major pathway for removing DNA lesions arising from endogenous processes as well as those induced by exposure to exogenous chemicals or irradiation. BER is initiated by DNA glycosylases that excise aberrant bases from DNA by cleavage of the N-glycosidic bond linking to the base of its deoxyribose sugar. Uracil N-glycosylase (UNG) is the enzyme responsible for the first step in the BER pathway that specifically removes uracil from DNA. The UNG gene undergoes both temporal and spatial regulation mainly at the level of transcription. Normally cancer cells undergo over-proliferation and up-regulate their UNG during tumorigenesis. In this study we examine the correlation between UNG level and carcinogenesis, and explore the possibility of using UNG as a marker for cancer diagnosis. Human UNG gene was amplified from the total RNA of the human choriocarcinoma cell line, JEG-3, by RT-PCR. After purification, the 942bp full-length UNG cDNA coding sequence was digested with EcoR I and Sal I, and cloned into the digested pET-21 to construct a recombinant vector, pUNG. The UNG protein was expressed under the control of T7 promoter in E. coli BL21 (DE3) cells induced with IPTG. After ultrasonic treatment, the cell lysate and precipitate were analyzed by SDS-PAGE and a 39kD band was detected. The plasmid was serially diluted at appropriate concentrations and employed as standards in the subsequent quantification. Total RNAs were extracted from 18 pairs of clinical samples, each pair contains a sample of esophageal squamous cell carcinoma (ESCC) tissue and its surrounding normal esophageal epithelia. The copy numbers of UNG mRNA in these RNA samples were determined by real-time quantitative RT-PCR using a Lightcycler (Roche). UNG was present in 13 cases of ESCC (13/18, n = 18) but absent in all of the normal tissues. The results indicated that there was a correlation between high level of UNG expression and the carcinogenesis of ESCC.

[Analysis of antimicrobial resistance of Streptococcus pneumoniae with restriction fragment length polymorphism of pbp2b gene and pulsed-field gel electrophoresis profiles among children].

UNLABELLED: Streptococcus pneumoniae is a common cause of potentially life-threatening infections such as meningitis, bacteraemia, pneumonia worldwide, for which children of preschool age are at particularly high risk. Since the late 1970s and 1980s, antibiotic resistance among pneumococci has become an emerging problem. Several multidrug-resistant clones have rapidly spread throughout the world. OBJECTIVE: (1) To investigate the prevalence of penicillin and other antibiotics nonsusceptibility among pneumococci. (2) To analyze the correlation of pbp2b amplicon profiles with penicillin resistance. (3) To serotype 31 isolates of penicillin-resistant pneumococci by latex agglutination. (4) To analyze the chromosomal relatedness of serotype 23F and 6 isolates of penicillin-resistant pneumococci by using pulsed-field gel electrophoresis (PFGE) and characterize these isolates in molecular epidemiology. METHODS: (1) Susceptibility was determined by using broth microdilution, E-test, and K-B disk. (2) The correlation of pbp2b amplicon profiles with penicillin resistance was assessed by restriction fragment length polymorphism (RFLP). (3) Serotyping of penicillin-resistant pneumococcal isolates was performed by using latex agglutination. (4) The properties of serotype 23F and 6 isolates of penicillin-resistant pneumococci were assessed by PFGE. RESULTS: S. pneumoniae with increased nonsusceptibility (including intermediate strains and resistant strains) to penicillin G was 9.9% in 1997, 12.6% in 1998, 14.6% in 2000; to cefuroxime 4.2%, 1.5%, 8.2%; to cefotaxime 0.0%, 1.7%, 1.0% respectively. There were no statistically significant differences (P > 0.05). While resistance to erythromycin, trimethoprim-sulfamethoxazole and chloramphenicol increased significantly from 76.8% in 1997 to 87.4% in 2000, from 74.7% to 88.3%, and from 22.6% to 40.8%, respectively (P < 0.05). RFLP analysis of pneumococcal pbp2b-specific amplicons was effective for screening penicillin resistance. Of the 31 strains of penicillin-resistant pneumococci (MICs 0.12 - 2.0 micro g/ml) studied, 6 (19.4%) strains (MICs 0.12 - 0.19 micro g/ml) were serotype 23F and 3 (9.7%) strains (MICs 0.5 - 1.5 micro g/ml) were serotype 6. There were nearly identical susceptibility to antibiotics and identical PFGE patterns in the former, and there were different susceptibility to antibiotics and different PFGE patterns in the latter. Three serotype 6 strains had different susceptibility to antibiotics and different PFGE patterns, which suggested that those strains may be scattered. CONCLUSION: Generally beta-lactams retained their activity against S. pneumoniae in Beijing. Resistance to erythromycin, trimethoprim-sulfamethoxazole, and chloramphenicol increased drastically. RFLP analysis of pneumococcal pbp2b-specific amplicons was effective for screening penicillin resistance. In 6 strains of serotype 23 F there were nearly identical susceptibility to antibiotics and identical PFGE patterns, which suggested the probability that there was a spread of serotype 23F isolates with low-level penicillin resistance in local area.