Asymmetric hydroformylation of styrene catalyzed by pyranoside diphosphite-rh(Ⅰ) complexes

2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Developing a platform of environmental omics for the green-lipped mussel Perna viridis

Session Track: Aquatic and terrestrial ecotoxicologyOral presentationConference Theme: Science across bridges, borders and boundariesThe green-lipped mussel Perna viridis is an important marine biomonitor species in pollution monitoring and ecotoxicological studies in Asia-Pacific region, and considered as a subtropical equivalent biomonitor of the temperate Mytilus species. However, the genomic information of P. viridis is still largely unexplored when compared with Mytilus species. This study aimed to establish a transcriptomic profile of P. viridis using the next generation sequencing technology and provide a good representative set of genomic information for elucidation of toxic mechanisms upon pollution stresses and identification of a suite of suitable biomarkers for monitoring marine pollution and environmental stresses. To obtain a wide spectrum of environmental-associated transcripts, adult mussels (4-5 cm shell length) were collected from different locations in Hong Kong and from those after 24-hour exposures to various challenges of physical stresses and chemical pollutants, so as to cover a wide range of stress-associated transcription patterns for future environmental studies. Two males and females from each location and from each treatment were chosen for obtaining the three target tissues (i.e., hepatopancreas, gill and adductor muscle). For each sex and each tissue type, a total RNA sample was extracted from pooled tissues from the field and laboratory treated mussels. The RNA sample was subjected to cDNA library construction, followed by the RNA-sequencing using a Solexa GAIIx (Illumina). Including the splicing variants, a de novo assembly of a total length of 295,064,579 base-pair (bp) contig was obtained, with 233,257 contigs assembled of an average size of 1264 bp. The 192,879 non-redundant assembled transcripts were blasted against the NCBI nr database and three molluscan EST databases, and resulted in 44,713 transcripts with at least a blast hit, and having a top match with the sequences from the Pacific oyster, Crassostrea gigas (27,651 transcripts). A total of 5,131 transcripts were assigned with KEGG annotation involving in 329 pathways. Based on multivariate statistical analysis, expression patterns of genes from stress associated responses and detoxification were strongly tissue-specific but the differences between genders were little. The anticipated genomic database generated from this study will further strengthen the role of P. viridis as a universal marine biomonitor in the Asia-Pacific region.published_or_final_versio

Quantification and viability analyses of Pseudokirchneriella subcapitata algal cells using image-based cytometry

This work aims to evaluate the feasibility of using image-based cytometry (IBC) in the analysis of algal cell quantification and viability, using Pseudokirchneriella subcapitata as a cell model. Cell concentration was determined by IBC to be in a linear range between 1×105 and 8×106 cells mL1. Algal viability was defined on the basis that the intact membrane of viable cells excludes the SYTOX Green (SG) probe. The disruption of membrane integrity represents irreversible damage and consequently results in cell death. Using IBC, we were able to successfully discriminate between live (SG-negative cells) and dead algal cells (heat-treated at 65 °C for 60 min; SG-positive cells). The observed viability of algal populations containing different proportions of killed cells was well correlated (R 2=0.994) with the theoretical viability. The validation of the use of this technology was carried out by exposing algal cells of P. subcapitata to a copper stress test for 96 h. IBC allowed us to follow the evolution of cell concentration and the viability of copper-exposed algal populations. This technology overcomes several main drawbacks usually associated with microscopy counting, such as labour-intensive experiments, tedious work and lack of the representativeness of the cell counting. In conclusion, IBC allowed a fast and automated determination of the total number of algal cells and allowed us to analyse viability. This technology can provide a useful tool for a wide variety of fields that utilise microalgae, such as the aquatic toxicology and biotechnology fields.FCT Strategic Project PEst- OE/EQB/LA0023/2013. The post-doctoral grant from FCT (SFRH/BPD/72816/2010)

De novo transcriptome analysis of Perna viridis highlights tissue-specific patterns for environmental studies

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AKR7A3 suppresses tumorigenicity and chemoresistance in hepatocellular carcinoma through attenuation of ERK, c-Jun and NF-κB signaling pathways

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Human papillomavirus status in southern Chinese women

1. The overall and type-specific human papillomavirus (HPV) prevalence differed between Hong Kong and Guangzhou healthy women. The prevalence of HPV was significantly higher in Guangzhou than Hong Kong women. Younger women had significantly higher risk of HPV infection. 2. HPV16 remained the most common type detected in both regions; the frequency increased with increasing disease severity. The prevalence of HPV58 and HPV52 was relatively high in women with normal cervix and precancerous lesions.published_or_final_versio

Mannose-binding lectin in severe acute respiratory syndrome coronavirus infection

Little is known about the innate immune response to severe acute respiratory syndrome (SARS) coronavirus (CoV) infection. Mannose-binding lectin (MBL), a key molecule in innate immunity, functions as an ante-antibody before the specific antibody response. Here, we describe a case-control study that included 569 patients with SARS and 1188 control subjects and used in vitro assays to investigate the role that MBL plays in SARS-CoV infection. The distribution of MBL gene polymorphisms was significantly different between patients with SARS and control subjects, with a higher frequency of haplotypes associated with low or deficient serum levels of MBL in patients with SARS than in control subjects. Serum levels of MBL were also significantly lower in patients with SARS than in control subjects. There was, however, no association between MBL genotypes, which are associated with low or deficient serum levels of MBL, and mortality related to SARS. MBL could bind SARS-CoV in a dose- and calcium-dependent and mannan-inhibitable fashion in vitro, suggesting that binding is through the carbohydrate recognition domains of MBL. Furthermore, deposition of complement C4 on SARS-CoV was enhanced by MBL. Inhibition of the infectivity of SARS-CoV by MBL in fetal rhesus kidney cells (FRhK-4) was also observed. These results suggest that MBL contributes to the first-line host defense against SARS-CoV and that MBL deficiency is a susceptibility factor for acquisition of SARS. © 2005 by the Infectious Diseases Society of America. All rights reserved.published_or_final_versio

First isolation of West Nile virus from a dromedary camel

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HPV infection and immunochemical detection of cell-cycle markers in verrucous carcinoma of the penis

Penile verrucous carcinoma is a rare disease and little is known of its aetiology or pathogenesis. In this study we examined cell-cycle proteins expression and correlation with human papillomavirus infection in a series of 15 pure penile verrucous carcinomas from a single centre. Of 148 penile tumours, 15 (10%) were diagnosed as pure verrucous carcinomas. The expression of the cell-cycle-associated proteins p53, p21, RB, p16INK4A and Ki67 were examined by immunohistochemistry. Human papillomavirus infection was determined by polymerase chain reaction to identify a wide range of virus types. The expression of p16INK4A and Ki67 was significantly lower in verrucous carcinoma than in usual type squamous cell carcinoma, whereas the expression of p53, p21 and RB was not significantly different. p53 showed basal expression in contrast to usual type squamous cell carcinoma. Human papillomavirus infection was present in only 3 out of 13 verrucous carcinomas. Unique low-risk, high-risk and mixed viral infections were observed in each of the three cases. In conclusion, lower levels of p16INK4A and Ki67 expressions differentiate penile verrucous carcinoma from usual type squamous cell carcinoma. The low Ki67 index reflects the slow-growing nature of verrucous tumours. The low level of p16INK4A expression and human papillomavirus detection suggests that penile verrucous carcinoma pathogenesis is unrelated to human papillomavirus infection and the oncogenes and tumour suppressor genes classically altered by virus infection.Peer reviewedFinal Accepted Versio