ICE1 demethylation drives the range expansion of a plant invader through cold tolerance divergence.

Cold tolerance adaption is a crucial determinant for the establishment and expansion of invasive alien plants into new cold environments; however, its evolutionary mechanism is poorly understood. Crofton weed (Ageratina adenophora), a highly invasive alien plant, is continuously spreading across subtropical areas in China, north-eastward from the first colonized south-western tropical regions, through cold tolerance evolution. Close relations between the cold tolerance levels of 34 populations, represented by 147 accessions, and the latitude, extreme lowest temperature, coldest month average temperature, and invasion period have provided direct insight into its cold tolerance divergence. A comparative study of the CBF pathway, associated with the cold tolerance enhancement of cold-susceptible CBF1-transgenic plant, among four geographically distinct crofton weed populations revealed that the CBF pathway plays a key role in the observed cold tolerance divergence. Four epialleles of the cold response regulator ICE1 ranged from 66 to 50 methylated cytosines, representing a 4.4% to 3.3% methylation rate and significantly corresponding to the lowest to highest cold tolerance levels among these different populations. The significant negative relation between the transcription levels of the primary CBF pathway members, except for CBF2, and the methylation levels among the four populations firstly demonstrates that the demethylation-upregulated transcription level of CBF pathway is responsible for this evolution. These facts, combined with the cold tolerance variation and methylation found among three native and two other introduced populations, indicate that the ICE1-demethylated upregulation of cold tolerance may be the underlying evolutionary mechanism allowing crofton weed to expand northward in China.

Patterns of genetic diversity reveal multiple introductions and recurrent founder effects during range expansion in invasive populations of Geranium carolinianum (Geraniaceae).

Genetic diversity, and thus the adaptive potential of invasive populations, is largely based on three factors: patterns of genetic diversity in the species' native range, the number and location of introductions and the number of founding individuals per introduction. Specifically, reductions in genetic diversity ('founder effects') should be stronger for species with low within-population diversity in their native range and few introductions of few individuals to the invasive range. We test these predictions with Geranium carolinianum, a winter annual herb native to North America and invasive in China. We measure the extent of founder effects using allozymes and microsatellites, and ask whether this is consistent with its colonization history and patterns of diversity in the native range. In the native range, genetic diversity is higher and structure is lower than expected based on life history traits. In China, our results provide evidence for multiple introductions near Nanjing, Jiangsu province, with subsequent range expansion to the west and south. Patterns of genetic diversity across China reveal weak founder effects that are driven largely by low-diversity populations at the expansion front, away from the introduction location. This suggests that reduced diversity in China has resulted from successive founder events during range expansion, and that the loss of genetic diversity in the Nanjing area was mitigated by multiple introductions from diverse source populations. This has implications for the future of G. carolinianum in China, as continued gene flow among populations should eventually increase genetic diversity within the more recently founded populations.

Isolation and characterization of microsatellite DNA loci for wild Brassica juncea (Brassicaceae).

Wild Brassica juncea is a widespread weed in China with increasingly great impact on the yield of many crops. This study aimed to develop microsatellite markers for assessing the genetic diversity and population genetic structure of B. juncea, and to provide basic information for biological and chemical control of the weed. The compound microsatellite marker technique was used to develop markers for investigating population genetics of wild B. juncea. Twelve loci were obtained, each of which showed high polymorphisms when tested in two populations in Sichuan and Jiangsu Provinces. The number of alleles per locus ranged from 4 to 27, with an average of 15.2 alleles per locus. The newly developed microsatellite loci will be informative for further investigations of the population genetics and evolutionary patterns of wild B. juncea.

Advances in plastic and cosmetic surgery at home and abroad - a bibliometric analysis.

BACKGROUND: Plastic and cosmetic surgery is a new branch deriving from plastic surgery. Although several studies concerning advances in plastic and cosmetic surgeries have been reported, most literatures focus on specific diagnosis and treatment technology, but not the overall progress. AIM: We attempt to use bibiometric analysis to investigate main research hotspots at home and abroad, outstanding researchers and excellent institutions. MATERIALS AND METHODS: We retrieved relevant literatures published between 2007 and 2011 in five foreign and four Chinese journals. gCLUTO was used to perform double clustering analysis. Price's Law was used to analyze authors with high yield. Literature profiling was performed to construct author-keyword and institution-keyword matrix to comprehend research feature of high yield authors and research institutions. RESULTS: A total of 67 and 94 high-frequency words were obtained from English and Chinese journals. Clustering analysis indicated that research hotspots at home and abroad mainly included side-effects of augmentation mammoplasty and its therapy, eyelid plastic surgery, cartilage transplantation and/or cartilage suture in nose plastic surgery, plastic surgery in cheilopalatognathus and nasal deformity, construction of surgical flaps, and facial plastic cosmetology. In addition, several authors and institutions with high yield also had been identified and they might have different research features. CONCLUSIONS: We investigate advances, hotspots, experts and their institutions in plastic and cosmetic surgery in recent five years at home and abroad, which would provide some research directions for professionals of plastic and cosmetic surgery.

First Report of Southern Blight on Canadian Goldenrod (Solidago canadensis) Caused by Sclerotium rolfsii in China.

Canadian goldenrod (Solidago canadensis L., Asteraceae) is a rhizomatous perennial plant native to North America that has invaded eastern China and continues to spread northward and westward. It is quite common on field borders, roadsides, and in undeveloped areas, posing a serious threat to native ecosystems and their biodiversity. During the late summers of 2007 and 2008, wilted Canadian goldenrod plants were occasionally found in invasive populations in the suburb of Nanjing city. Wilted plants were transplanted and maintained in a greenhouse at Nanjing Agricultural University. A white mass of fungal hyphae, which grew on the soil surface around the stem of the symptomatic S. canadesis plants and eventually covered the stem, was observed. Initially, the base of the stem became yellow, turned brown, and the light brown discoloration extended up the stem to a height of 3 to 7 cm. The leaves then collapsed, starting from the top until the entire plant wilted. The fungus produced numerous, small, roundish sclerotia of uniform size (0.7 to 2.0 mm in diameter), which were white at first and then became brown to dark brown. The fungus grew into the stems and downward into the rhizome area, but no sclerotia were detected inside the stem or root. Diseased tissue with sclerotia was disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar amended with 100 mg/liter of streptomycin sulfate. On the basis of sclerotia morphology and the presence of clamp connections at hyphal septa, the fungus was identified as Sclerotium rolfsii. Pathogenicity of the isolate was confirmed by inoculating 1-year-old S. canadensis plants (average 1.5 m high) grown in pots. The inoculum consisted of cottonseed hulls infested with mycelium and sclerotia of the pathogen and was placed on the soil surface around the base of each unwounded plant. Noninoculated plants served as controls. The pathogenicity test was conducted twice. After inoculation, the plants were maintained at high humidity and 30°C for 3 days and then transferred to a greenhouse. All inoculated plants developed symptoms of southern blight. Inoculated plants developed symptoms of wilting 5 to 7 days after inoculation and were completely wilted within 15 to 20 days. Symptoms of wilting were soon followed by the appearance of white-to-light brown sclerotia on the collar region. Control plants remained symptomless and Sclerotium rolfsii was reisolated from inoculated plants. To our knowledge, this is the first report of southern blight of Canadian goldenrod caused by Sclerotium rolfsii in China.

Efficacy of nonwoven fabric bioreactor immobilized with porcine hepatocytes for ex vivo xenogeneic perfusion treatment of liver failure in dogs.

We have developed a new bioartificial liver bioreactor filled with porcine hepatocytes immobilized on polyester nonwoven fabric (NWF). In this study, we investigated the efficacy of our hybrid bioartificial liver system incorporating the NWF bioreactors and an immunoglobulin adsorbent column for perfusion treatment in a canine liver failure model. Xenogeneic perfusion treatment for operative canine liver failure models were performed for 3 h, and survival time, intracranial pressure, and blood and cerebrospinal fluid data were documented. Treatment was carried out without obstruction by immunological rejection when immunoglobulin adsorbent columns were used with the NWF bioreactors in combination. Dogs treated with this system exhibited a restricted increase of intracranial pressure and significant compensatory effects on blood and cerebrospinal amino acid imbalances as shown by a significant improvement of Fischer's ratio. On the other hand, relatively low capacity for ammonia elimination was shown as compared with homologous direct hemoperfusion.

Variation between ASP-1 molecules from Ancylostoma caninum in China and the United States.

Hookworm infection continues to be a serious problem in rural areas of China. Rapid reinfection and high cost limit the effectiveness of deworming programs. Vaccination offers an attractive alternative to mass chemotherapy. However, variation in vaccine antigens from field hookworm populations could conceivably limit efficacy of a vaccine developed from laboratory strains. Reported here are initial experiments to ascertain levels of molecular variation in a promising vaccine antigen, ASP-1, from the dog hookworm Ancylostoma caninum. ASP-1 from a Chinese strain of A. caninum was isolated from a third-stage larval cDNA library and compared to ASP-1 from a U.S. strain. There was 97% and 98% similarity in the DNA and amino acid sequences, respectively. There were 42 polymorphic sites between the sequences, 30 of which were synonymous. The 12 nonsynonymous substitutions resulted in 10 changes in the deduced amino acid sequence. Five of the amino acid changes were in the N-terminal domain, whereas the C-terminal domain was more highly conserved, containing only 2 amino acid changes. The results suggest that the effect of molecular variation in antigens from geographically separated parasite populations should be considered during vaccine development.

Hookworm burden reductions in BALB/c mice vaccinated with recombinant Ancylostoma secreted proteins (ASPs) from Ancylostoma duodenale, Ancylostoma caninum and Necator americanus.

Vaccination of mice with alum-precipitated recombinant Ancylostoma secreted protein-1 from the canine hookworm Ancylostoma caninum (Ac-ASP-1) results in protection against A. caninum larval challenge. Vaccine protection is manifested by host reductions in hookworm burden compared to control mice. The goal of this study was to determine whether ASP antigens cloned and expressed from different hookworm species will cross protect against A. caninum larval challenge. Cross-species protection against A. caninum challenge infections was observed with immunizations using recombinant ASP-1 from the human hookworms Ancylostoma duodenale and Necator americanus. However, the degree of protection was proportional to the extent of amino acid sequence homology between the ASP immunogen used for vaccination and the Ac-ASP-1 produced by the challenge larval strain. Vaccine protection was noted to decrease significantly as amino acid sequence homologies diverged 10% or more. It was also determined that Ac-ASP-2, a molecule cloned from A. caninum having 55% amino acid sequence homology to the C-terminus of Ac-ASP-1, did not elicit vaccine protection. These observations were partly reflected in the titer of antibodies that recognize Ac-ASP-1. The studies reported here will help to design immunogenic peptide vaccines based on the sequence divergence of hookworm ASPs.

Comparative evaluation of different membranes for the construction of an artificial liver support system.

During the past decades, many technological improvements have been made in the construction of extracorporeal liver support systems. Among these achievements, membranes of artificial capillary system, used as substrates of hepatocyte growth, aroused our interest in their application for the construction of bioreactors. The present paper studied the comparison of hepatocyte growth and function on six different membranes. Four of them are cellulose based membranes, Cuprophan, Hemophan, Cellulose acetate, and Bioflux; two are synthetic polymer SPAN and Polysulphone. Human hepatoma cell line SMMC-7721, with moderately differentiated hepatocyte-specific functions, was inoculated into the hollow fiber cartridges. These cells were allowed to attach and to grow over these membranes. It was found that there existed differences in hepatocyte immobilization and growth among these membranes. They influenced the growth and functions of hepatoma cells in vitro to some extent. These results show that membrane is an important factor in the construction of capillary membrane bioreactors for artificial liver support.

[Diastereospecific synthesis of antifungal threo-BAY 19139].

BAY 19139, 1-(4-chlorophenoxy)-1-(1-imidazolyl)-3,3-dimethyl-2-butanol is a new imidazolyl derivative of antifungal agent. Its threo-isomer(Ia) shows marked antifungal activity, and the antiprotozoal activity is higher than the well-known metronidazole or clotrimazole, but the activity of the erythro-isomer is weak. This paper reports the sequential reactions of chloro or bromo-oxirane with p-chlorophenolate, and then with sodium imidazolate in two stereocontrolled steps to the threo-BAY 19139 (Ia). Halo-oxirane is accomplished by the stereochemistry of ring closure of alpha, alpha-dihalopinacolone. The molecular structure of Ia was confirmed unambiguously by X-ray crystal analysis. Furthermore, the nucleophilic substitution of chloro-oxirane was investigated. We found that under the solid-liquid PTC condition at room temperature, the reaction time was shortened and a higher yield was obtained.