First case of Shewanella indica isolated from a Bryde's whale (Balaenoptera edeni) stranded in the northern Beibu Gulf, China.

The purpose of this study was to culture and characterise bacteria from an intact abscess on the skin of a dead Bryde's whale (Balaenoptera edeni) which stranded in the northern Beibu Gulf, China. To grow bacteria, samples from the abscess were added to blood agar. After incubation, yellowish mucous colonies were visualized. The bacterium was firstly recognised as Shewanella algae by the VITEK® 2 System. However, by using 16S rRNA gene sequencing the bacterium was finally identified as S. indica. To characterise the bacterium, antibiotic susceptibility and virulence factors, such as hemolysis and biofilm formation were investigated. The bacterium is capable of ß-hemolysis and biofilm formation and it is also sensitive to several different classes of antibiotics, such as ß-lactams, quinolones, and aminoglycosides. To date there have been no reports of this bacterium causing infections in humans or animals. However, in this study we described the first case of S. indica isolated from an intact abscess on the back of a Bryde's whale.

Microbial communities in different regions of the gastrointestinal tract in East Asian finless porpoises (Neophocaena asiaeorientalis sunameri).

Mammalian gastrointestinal (GI) tract microbial communities are critical for host health. However, the microbiota along the GI tract in cetaceans has not been well characterized compared to other animals. In this study, the bacteria and fungi present in the stomach, foregut, hindgut and feces, of East Asian finless porpoises (Neophocaena asiaeorientalis sunameri, EAFPs) were characterized using high-throughput sequencing analysis. The bacterial and fungal diversity and richness in the stomach, hindgut and fecal samples tended to be higher than those in the foregut. Bacterial taxonomic compositions found in the hindgut and feces were different from those seen in the stomach and foregut. A greater proportion of strict anaerobic bacteria including Clostridia, Fusobacteria, and Ruminococcaceae were found in the hindgut and fecal samples. The fungal communities present in stomach samples differed from those detected in other regions to some extent. Zygomycota and Neocallimastigomycota were more predominant in the stomach. Some potential pathogens, such as Helicobacter spp. and Vibrio spp., were commonly present along the GI tract. Our study confirms that the fecal microbiota can represent the whole GI tract to some extent because of their relatively higher microbial diversity and presence of potential pathogens. Our study provides the first comprehensive characterization of the EAFPs GI microbiota, expanding on the current knowledge about the bacterial diversity in the GI tract of cetaceans. In addition, this is the first study characterizing the fungal diversity of any species of porpoise.

Organization and characteristics of the major histocompatibility complex class II region in the Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis).

Little is known about the major histocompatibility complex (MHC) in the genome of Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) (YFP) or other cetaceans. In this study, a high-quality YFP bacterial artificial chromosome (BAC) library was constructed. We then determined the organization and characterization of YFP MHC class II region by screening the BAC library, followed by sequencing and assembly of positive BAC clones. The YFP MHC class II region consists of two segregated contigs (218,725 bp and 328,435 bp respectively) that include only eight expressed MHC class II genes, three pseudo MHC genes and twelve non-MHC genes. The YFP has fewer MHC class II genes than ruminants, showing locus reduction in DRB, DQA, DQB, and loss of DY. In addition, phylogenic and evolutionary analyses indicated that the DRB, DQA and DQB genes might have undergone birth-and-death evolution, whereas the DQB gene might have evolved under positive selection in cetaceans. These findings provide an essential foundation for future work, such as estimating MHC genetic variation in the YFP or other cetaceans. This work is the first report on the MHC class II region in cetaceans and offers valuable information for understanding the evolution of MHC genome in cetaceans.

Assembly and characterization of the MHC class I region of the Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis).

The Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis; YFP) is the sole freshwater subspecies of N. asiaeorientalis and is now critically endangered. Major histocompatibility complex (MHC) is a family of highly polymorphic genes that play an important immunological role in antigen presentation in the vertebrates. Currently, however, little is known about MHC region in the genome of the YFP, which hampers conservation genetics and evolutionary ecology study using MHC genes. In this work, a nucleotide sequence of 774,811 bp covering the YFP MHC class I region was obtained by screening a YFP bacterial artificial chromosome (BAC) library, followed by sequencing and assembly of positive BAC clones. A total of 45 genes were successfully annotated, of which four were MHC class I genes. There are high similarities among the four YFP MHC class I genes (>94%). Divergence in the coding region of the four YFP MHC class I genes is mainly localized to exons 2 and 3, which encode the antigen-binding sites of MHC class I genes. Additionally, comparison of the MHC structure in YFP to those of cattle, sheep, and pig showed that MHC class I genes are located in genome regions with regard to the conserved genes, and the YFP contains the fewest MHC class I genes among these species. This is the first report characterizing a cetacean MHC class I region and describing its organization, which would be valuable for further investigation of adaptation in natural populations of the YFP and other cetaceans.

De novo assembly and characterization of narrow-ridged finless porpoise renal transcriptome and identification of candidate genes involved in osmoregulation.

During the evolutionary transition from land to water, cetaceans have undergone numerous critical challenges, with osmoregulation being the major one. Two subspecies of the narrow-ridged finless porpoise (Neophocaena asiaeorientalis), the freshwater Yangtze finless porpoise (N. a. asiaeorientalis, NAA) and the marine East Asian finless porpoise (N. a. sunameri, NAS), provide excellent subjects to understand the genetic basis of osmoregulatory divergence between freshwater and marine mammals. The kidney plays an important and well-established role in osmoregulation in marine mammals and thus, herein, we utilized RNA-seq to characterize the renal transcriptome and preliminarily analyze the divergence between the NAA and the NAS. Approximately 48.98 million clean reads from NAS and 49.40 million clean reads from NAA were obtained by RNA-Seq. And 73,449 (NAS) and 68,073 (NAA) unigenes were assembled. Among these annotations, 22,231 (NAS) and 21,849 (NAA) unigenes were annotated against the NCBI nr protein database. The ion channel complex GO term and four pathways were detected as relevant to osmoregulation by GO and KEGG pathway classification of these annotated unigenes. Although the endangered status of the study species prevented analysis of biological replicates, we identified nine differentially expressed genes (DEGs) that may be vital in the osmoregulation of the narrow-ridged finless porpoise and worthwhile for future studies. Of these DEGs, the differential expression and distribution of the aquaporin-2 (AQP2) in the collecting duct were verified using immunohistochemical experiments. Together, this work is the first report of renal transcriptome sequencing in cetaceans, and it will provide a valuable resource for future molecular genetics studies on cetacean osmoregulation.

Evidence for positive selection on the leptin gene in Cetacea and Pinnipedia.

The leptin gene has received intensive attention and scientific investigation for its importance in energy homeostasis and reproductive regulation in mammals. Furthermore, study of the leptin gene is of crucial importance for public health, particularly for its role in obesity, as well as for other numerous physiological roles that it plays in mammals. In the present work, we report the identification of novel leptin genes in 4 species of Cetacea, and a comparison with 55 publicly available leptin sequences from mammalian genome assemblies and previous studies. Our study provides evidence for positive selection in the suborder Odontoceti (toothed whales) of the Cetacea and the family Phocidae (earless seals) of the Pinnipedia. We also detected positive selection in several leptin gene residues in these two lineages. To test whether leptin and its receptor evolved in a coordinated manner, we analyzed 24 leptin receptor gene (LPR) sequences from available mammalian genome assemblies and other published data. Unlike the case of leptin, our analyses did not find evidence of positive selection for LPR across the Cetacea and Pinnipedia lineages. In line with this, positively selected sites identified in the leptin genes of these two lineages were located outside of leptin receptor binding sites, which at least partially explains why co-evolution of leptin and its receptor was not observed in the present study. Our study provides interesting insights into current understanding of the evolution of mammalian leptin genes in response to selective pressures from life in an aquatic environment, and leads to a hypothesis that new tissue specificity or novel physiologic functions of leptin genes may have arisen in both odontocetes and phocids. Additional data from other species encompassing varying life histories and functional tests of the adaptive role of the amino acid changes identified in this study will help determine the factors that promote the adaptive evolution of the leptin genes in marine mammals.

[Value of 18F-FETNIM PET-CT for detection of tumor hypoxia in non-small-cell lung cancer].

OBJECTIVE: To assess the feasibility of [(18)F]fluoroerythronitroimidazole ((18)F-FETNIM) with integrated positron emission tomography and computed tomography (PET-CT) imaging in detection of hypoxia in non-small-cell lung cancer (NSCLC) patients. METHODS: Forty-two patients with newly diagnosed NSCLC underwent (18)F-FETNIM PET-CT before treatment. Nineteen patients rested for approximately 120 minutes before undergoing PET-CT, 23 patients underwent 2 sequential PET-CT scans at 60 minutes and 120 minutes after intravenous injection (18)F-FETNIM. (18)F-FETNIM uptake was quantified by calculating the maximum standardized uptake value in the tumor (SUVmax-T) and contralateral normal lung tissue (SUVmax-N). Regions of interest (ROIs) were drawn in the tumor and contralateral position and the radioactivity ratio of tumor to normal (T/N) was calculated. RESULTS: SUVmax-T (2.43 +/- 1.34) was significantly higher than SUVmax-N (0.87 +/- 0.46, P < 0.001) at 120 min. SUVmax-T (2.80 +/- 1.09) and SUVmax-N (1.16 +/- 0.56) at 60 min were significantly higher than SUVmax-T (2.61 +/- 1.10) and SUVmax-N (P < 0.01) at 120 min. T/N (2.56 +/- 0.71) at 60 min was higher than that at 120 min (2.48 +/- 0.60), but the difference between them was not significant (P = 0.324). CONCLUSION: Our results indicate that (18)F-FETNIM PET-CT may be a useful tool for evaluating hypoxia and may be a means to target specifically tumor cells resistant to conventional treatment before and during ongoing therapy in NSCLC.

Downregulation of T helper cell type 3 in patients with acute coronary syndrome.

BACKGROUND AND AIMS: There is an imbalance between Th1 and Th2 in the development and progression of atherosclerosis and in patients with acute coronary syndrome (ACS) including acute myocardial infarction (AMI) and unstable angina. T helper cell type 3 (Th3), which primarily secretes transforming growth factor beta-1 (TGF-beta1), has been shown to inhibit both Th1 and Th2 cells. The present study was designed to investigate whether Th3 cells are involved in plaque destabilization and the onset of ACS. METHODS: Ninety one patients who underwent diagnostic catheterization were classified into four groups (AMI group, unstable angina group, stable angina group and chest pain syndrome group). The cell frequencies of Th1, Th2 and Th3 were detected using flow cytometry, and the concentrations of their related cytokines IFN-gamma, IL-4 and TGF-beta1 were studied by ELISA. RESULTS: Apart from the imbalance between Th1 and Th2, results revealed a significant decrease in peripheral Th3 number and levels of TGF-beta1 in patients with ACS as compared with those in patients with stable angina and chest pain syndrome (p<0.01). CONCLUSIONS: Downregulation of Th3 cells in patients with ACS may play a potential role in plaque destabilization and the onset of ACS.

Population genetic structure of the Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis): implications for management and conservation.

Understanding the population genetic structure is a prerequisite for conservation of a species. The degree of genetic variability characteristic of the mitochondrial DNA control region has been widely exploited in studies of population genetic structure and can be useful in identifying meaningful population subdivisions. To estimate the genetic profile of the Yangtze finless porpoise (Neophocaena phocaenoides asiaeorientalis), an endangered freshwater population endemic to China, the complete mtDNA control region was examined in 39 individuals belonging to seven different stocks inhabiting the middle and lower reaches of the Yangtze River. Very low genetic diversity was found (nucleotide diversity 0.0011 +/- 0.0002 and haplotypic diversity 0.65 +/- 0.05). The mtDNA genetic pattern of the Yangtze population appears to indicate a founder event in its evolutionary history and to support the marine origin for this population. Analyses by Fst and phi(st) yielded statistically significant population genetic structure (Fst = 0.44, P < 0.05; phi(st) = 0.36, P < 0.05). These results may have significant implications for the management and conservation of the Yangtze finless porpoise in the future.