PM2.5 and PM10 samples were collected at four major cities in the Pearl River Delta (PRD), South China, during winter and summer in 2002. Six water-soluble ions, Na^+, NH4+, K^+, Cl^-, NO3^- and SO4^2- were measu...PM2.5 and PM10 samples were collected at four major cities in the Pearl River Delta (PRD), South China, during winter and summer in 2002. Six water-soluble ions, Na^+, NH4+, K^+, Cl^-, NO3^- and SO4^2- were measured using ion chromatography. On average, ionic species accounted for 53.3% and 40.5% for PM2.5 and PM10, respectively in winter and 39.4% and 35.2%, respectively in summer. Secondary ions such as sulfate, nitrate and ammonium accounted for the major part of the total ionic species. Sulfate was the most abundant species followed by nitrate. Overall, a regional pollution tendency was shown that there were higher concentrations of sulfate, nitrate and ammonium in Guangzhou City than those in the other PRD cities. Significant seasonal variations were also observed with higher levels of species in winter but lower in summer. The Asian monsoon system was favorable for removal and diffusion of air pollutants in PRD in summer while highly loading of local industrial emissions tended to deteriorate the air quality as well. NO3^-/SO4^2- ratio indicated that mobile sources have considerably contribution to the urban aerosol, and stationary sources should not be neglected. Besides the primary emissions, complex atmospheric reactions under favorable weather conditions should be paid more attention for the control of primary emission in the PRD region.展开更多
Pseudomonas aeruginosa causes severe and persistent infections in immune compromised individuals and cystic fibrosis sufferers. The infection is hard to eradi- cate as P. aeruginosa has developed strong resistance to ...Pseudomonas aeruginosa causes severe and persistent infections in immune compromised individuals and cystic fibrosis sufferers. The infection is hard to eradi- cate as P. aeruginosa has developed strong resistance to most conventional antibiotics. The problem is further compounded by the ability of the pathogen to form biofilm matrix, which provides bacterial cells a protected environment withstanding various stresses including antibiotics. Quorum sensing (QS), a cell density-based intercellular communication system, which plays a key role in regulation of the bacterial virulence and biofilm formation, could be a promising target for developing new strategies against P. aeruginosa infection. The QS network of P. aeruginosa is organized in a multi-layered hierarchy consisting of at least four interconnected signaling mechanisms. Evidence is accumulating that the QS regulatory network not only responds to bacte- rial population changes but also could react to envi- ronmental stress cues. This plasticity should be taken into consideration during exploration and development of anti-QS therapeutics.展开更多
Although the incidence of hepatolithiasis is decreasing as the pattern of gallstone disease changes in Asia, the prevalence of hepatolithiasis is persistently high, especially in Far Eastern countries. Hepatolithiasis...Although the incidence of hepatolithiasis is decreasing as the pattern of gallstone disease changes in Asia, the prevalence of hepatolithiasis is persistently high, especially in Far Eastern countries. Hepatolithiasis is an established risk factor for cholangiocarcinoma(CCA), and chronic proliferative inflammation may be involved in biliary carcinogenesis and in inducing the upregulation of cell-proliferating factors. With the use of advanced imaging modalities, there has been much improvement in the management of hepatolithiasis and the diagnosis of hepatolithiasis-associated CCA(HLCCA). However, there are many problems in managing the strictures in hepatolithiasis and differentiating them from infiltrating types of CCA. Surgical resection is recommended in cases of single lobe hepatolithiasis with atrophy, uncontrolled stricture, symptom duration of more than 10 years, and long history of biliaryenteric anastomosis. Even after resection, patients should be followed with caution for development of HL-CCA, because HL-CCA is an independent prognostic factor for survival. It is not yet clear whether hepatic resection can reduce the occurrence of subsequent HL-CCA. Furthermore, there are no consistent findings regarding prediction of subsequent HL-CCA in patients with hepatolithiasis. In the management of hepatolithiasis, important factors are the reduction of recurrence of cholangitis and suspicion of unrecognized HL-CCA.展开更多
Autoimmune chronic pancreatitis (AIP) is increasingly being recognized worldwidely, as knowledge of this entity builds up. Above all, AIP is a very attractive disease to clinicians in terms of its dramatic response ...Autoimmune chronic pancreatitis (AIP) is increasingly being recognized worldwidely, as knowledge of this entity builds up. Above all, AIP is a very attractive disease to clinicians in terms of its dramatic response to the oral steroid therapy in contrast to ordinary chronic pancreatitis. Although many characteristic findings of AIP have been described, definite diagnostic criteria have not been fully established. In the year 2002, the Japan Pancreas Society published the diagnostic criteria of AIP and many clinicians around the world use these criteria for the diagnosis of AIP. The diagnostic criteria proposed by the Japan Pancreas Society, however, are not completely satisfactory and some groups use their own criteria in reporting AIP. This review discusses several potential limitations of current diagnostic criteria for this increasingly recognized condition. The manuscript is organized to emphasize the need for convening a consensus to develop improved diagnostic criteria.展开更多
AIM:To evaluate the efficacy of simple and extended cholecystectomy for mucosa(T1a) or muscularis(T1b) gallbladder(GB) cancer. METHODS:Original studies on simple and extended cholecystectomy for T1a or T1b GB cancer w...AIM:To evaluate the efficacy of simple and extended cholecystectomy for mucosa(T1a) or muscularis(T1b) gallbladder(GB) cancer. METHODS:Original studies on simple and extended cholecystectomy for T1a or T1b GB cancer were searched from MEDLINE(PubMed) ,Cochrane Library,EMBase,and CancerLit using the search terms of GB,cancer/carcinoma/tumor/neoplasm. RESULTS:Twenty-nine out of the 2312 potentially relevant publications met the eligibility criteria.Of the 1266 patients with GB cancer included in the publications,706(55.8%) and 560(44.2%) had T1a and T1b GB cancer,respectively.Simple cholecystectomy for T1a and T1b GB cancer was performed in 590(83.6%) and 375(67.0%) patients,respectively(P<0.01) .In most series,the treatment of choice was simple cholecystectomy for T1a GB cancer patients with a 5-year survival rate of 100%.Lymph node metastasis was detected in 10.9% of the T1b GB cancer patients and in 1.8%of the T1a GB cancer patients,respectively(P<0.01) .Eight patients(1.1%) with T1a GB cancer and 52 patients(9.3%) with T1b GB cancer died of recurrent GB cancer(P<0.01) . CONCLUSION:Simple cholecystectomy represents the adequate treatment of T1a GB cancer.There is no definite evidence that extended cholecystectomy is advantageous over simple cholecystectomy for T1b GB cancer.展开更多
基金Project supported by the National Natural Science Founding of China(No.20347003,40121303)the Research Grants Council of Hong Kong(No.PolyU5038/01E,PolyU5145/03E)the Area of Strategic Development on Atmospheric and Urban Air Pollution of The Hong Kong Polytechnic University(No.A516,A510).
文摘PM2.5 and PM10 samples were collected at four major cities in the Pearl River Delta (PRD), South China, during winter and summer in 2002. Six water-soluble ions, Na^+, NH4+, K^+, Cl^-, NO3^- and SO4^2- were measured using ion chromatography. On average, ionic species accounted for 53.3% and 40.5% for PM2.5 and PM10, respectively in winter and 39.4% and 35.2%, respectively in summer. Secondary ions such as sulfate, nitrate and ammonium accounted for the major part of the total ionic species. Sulfate was the most abundant species followed by nitrate. Overall, a regional pollution tendency was shown that there were higher concentrations of sulfate, nitrate and ammonium in Guangzhou City than those in the other PRD cities. Significant seasonal variations were also observed with higher levels of species in winter but lower in summer. The Asian monsoon system was favorable for removal and diffusion of air pollutants in PRD in summer while highly loading of local industrial emissions tended to deteriorate the air quality as well. NO3^-/SO4^2- ratio indicated that mobile sources have considerably contribution to the urban aerosol, and stationary sources should not be neglected. Besides the primary emissions, complex atmospheric reactions under favorable weather conditions should be paid more attention for the control of primary emission in the PRD region.
基金This work was funded by the Biomedical Research Council, Agency for Science, Technology and Research (A'STAR), Singapore, and by the National Natural Science Foundation of China (Grant No. 31330002). We apologize to the scientists who made contributionsto the field, but their works have not been cited due to space limitations.
文摘Pseudomonas aeruginosa causes severe and persistent infections in immune compromised individuals and cystic fibrosis sufferers. The infection is hard to eradi- cate as P. aeruginosa has developed strong resistance to most conventional antibiotics. The problem is further compounded by the ability of the pathogen to form biofilm matrix, which provides bacterial cells a protected environment withstanding various stresses including antibiotics. Quorum sensing (QS), a cell density-based intercellular communication system, which plays a key role in regulation of the bacterial virulence and biofilm formation, could be a promising target for developing new strategies against P. aeruginosa infection. The QS network of P. aeruginosa is organized in a multi-layered hierarchy consisting of at least four interconnected signaling mechanisms. Evidence is accumulating that the QS regulatory network not only responds to bacte- rial population changes but also could react to envi- ronmental stress cues. This plasticity should be taken into consideration during exploration and development of anti-QS therapeutics.
文摘Although the incidence of hepatolithiasis is decreasing as the pattern of gallstone disease changes in Asia, the prevalence of hepatolithiasis is persistently high, especially in Far Eastern countries. Hepatolithiasis is an established risk factor for cholangiocarcinoma(CCA), and chronic proliferative inflammation may be involved in biliary carcinogenesis and in inducing the upregulation of cell-proliferating factors. With the use of advanced imaging modalities, there has been much improvement in the management of hepatolithiasis and the diagnosis of hepatolithiasis-associated CCA(HLCCA). However, there are many problems in managing the strictures in hepatolithiasis and differentiating them from infiltrating types of CCA. Surgical resection is recommended in cases of single lobe hepatolithiasis with atrophy, uncontrolled stricture, symptom duration of more than 10 years, and long history of biliaryenteric anastomosis. Even after resection, patients should be followed with caution for development of HL-CCA, because HL-CCA is an independent prognostic factor for survival. It is not yet clear whether hepatic resection can reduce the occurrence of subsequent HL-CCA. Furthermore, there are no consistent findings regarding prediction of subsequent HL-CCA in patients with hepatolithiasis. In the management of hepatolithiasis, important factors are the reduction of recurrence of cholangitis and suspicion of unrecognized HL-CCA.
文摘Autoimmune chronic pancreatitis (AIP) is increasingly being recognized worldwidely, as knowledge of this entity builds up. Above all, AIP is a very attractive disease to clinicians in terms of its dramatic response to the oral steroid therapy in contrast to ordinary chronic pancreatitis. Although many characteristic findings of AIP have been described, definite diagnostic criteria have not been fully established. In the year 2002, the Japan Pancreas Society published the diagnostic criteria of AIP and many clinicians around the world use these criteria for the diagnosis of AIP. The diagnostic criteria proposed by the Japan Pancreas Society, however, are not completely satisfactory and some groups use their own criteria in reporting AIP. This review discusses several potential limitations of current diagnostic criteria for this increasingly recognized condition. The manuscript is organized to emphasize the need for convening a consensus to develop improved diagnostic criteria.
文摘AIM:To evaluate the efficacy of simple and extended cholecystectomy for mucosa(T1a) or muscularis(T1b) gallbladder(GB) cancer. METHODS:Original studies on simple and extended cholecystectomy for T1a or T1b GB cancer were searched from MEDLINE(PubMed) ,Cochrane Library,EMBase,and CancerLit using the search terms of GB,cancer/carcinoma/tumor/neoplasm. RESULTS:Twenty-nine out of the 2312 potentially relevant publications met the eligibility criteria.Of the 1266 patients with GB cancer included in the publications,706(55.8%) and 560(44.2%) had T1a and T1b GB cancer,respectively.Simple cholecystectomy for T1a and T1b GB cancer was performed in 590(83.6%) and 375(67.0%) patients,respectively(P<0.01) .In most series,the treatment of choice was simple cholecystectomy for T1a GB cancer patients with a 5-year survival rate of 100%.Lymph node metastasis was detected in 10.9% of the T1b GB cancer patients and in 1.8%of the T1a GB cancer patients,respectively(P<0.01) .Eight patients(1.1%) with T1a GB cancer and 52 patients(9.3%) with T1b GB cancer died of recurrent GB cancer(P<0.01) . CONCLUSION:Simple cholecystectomy represents the adequate treatment of T1a GB cancer.There is no definite evidence that extended cholecystectomy is advantageous over simple cholecystectomy for T1b GB cancer.