To clarify the phylogenetic relationships and species status of Pneumocystis,the 5.8S rRNA gene and the internal transcribed spacers(ITS,1 and 2)of Pneumocystis rRNA derived from rat,gerbil and human were amplified,cl...To clarify the phylogenetic relationships and species status of Pneumocystis,the 5.8S rRNA gene and the internal transcribed spacers(ITS,1 and 2)of Pneumocystis rRNA derived from rat,gerbil and human were amplified,cloned and sequenced.The genetic distance matrix of six Pneumocystis species compared with other fungi like Taphrina and Saccharomyces indicated that the Pneumocystis genus contained multiple species including Pneumocystis from gerbil.The phylogenetic tree also showed that Pneumocystis from human and monkey formed one group and four rodent Pneumocystis formed another group.Among the four members,Pneumocystis wakefieldiae was most closely related to Pneumocystis murina and Pneumocystis carinii,and was least related to gerbil Pneumocystis.展开更多
Objective The objective of this article was to review the current advances in diagnostic methods for Acanthamoeba keratitis （AK）.Data sources Data used in this review were retrieved from PubMed （1970-2013）.The ter...Objective The objective of this article was to review the current advances in diagnostic methods for Acanthamoeba keratitis （AK）.Data sources Data used in this review were retrieved from PubMed （1970-2013）.The terms ＂Acanthamoeba keratitis＂ and ＂diagnosis＂ were used for the literature search.Study selection Data from published articles regarding AK and diagnosis in clinical trials were identified and reviewed.Results The diagnostic methods for the eight species implicated in AK were reviewed.Among all diagnostic procedures,corneal scraping and smear examination was an essential diagnostic method.Polymerase chain reaction was the most sensitive and accurate detection method.Culturing of Acanthamoeba was a reliable method for final diagnosis of AK.Confocal microscopy to detect Acanthamoeba was also effective,without any invasive procedure,and was helpful in the early diagnosis of AK.Conclusion Clinically,conjunction of various diagnostic methods to diagnose AK was necessary.展开更多
Background Pyruvate phosphate dikinase （PPDK） reversibly catalyzes the interconversion of phosphoenolpyruvate （PEP） and pyruvic acid,leading to catabolism and adenosine triphosphate （ATP） synthesis or gluconeoge...Background Pyruvate phosphate dikinase （PPDK） reversibly catalyzes the interconversion of phosphoenolpyruvate （PEP） and pyruvic acid,leading to catabolism and adenosine triphosphate （ATP） synthesis or gluconeogenesis and ATP consumption.Molecular modeling of PPDKs from divergent organisms demonstrates that the orientation of the phosphorylatable histidine residue within the central domain of PPDK determines whether this enzyme promotes catabolism or gluconeogenesis.The goal of this study was to determine whether PDDK from Giardia underwent adaptive evolution in order to produce more energy under anaerobic conditions.Methods A total of 123 PPDK sequences from protozoans,proteobacteria,plants,and algae were selected,based upon sequence similarities to Giardia lamblia PPDK and Zea mays PPDK.Three-dimensional （3-D） models were generated for PPDKs from divergent organisms and were used to compare the orientation of the phosphorylatable histidine residue within the central domain of PPDKs.These PPDKs were compared using a maximum-likelihood tree.Results For PPDK from Giardia,as well as from other anaerobic protozoans,the central domain tilted toward the N-terminal nucleotide-binding domain,indicating that this enzyme catalyzed ATP synthesis.Furthermore,the orientation of this central domain was determined by interactions between the N-and C-terminal domains.Phylogenetic analysis of the N-and C-terminal sequences of PPDKs from different species suggested that PPDK has likely undergone adaptive evolution in response to differences in environmental and metabolic conditions.Conclusion These results suggested that PPDK in anaerobic organisms is functionally adapted to generate energy more efficiently in an anaerobic environment.展开更多
基金Supported by the Natural Science Foundation of Beijing,China(Grant No.7052009)the National Natural Science Foundation of China(Grant No.30470243)
文摘To clarify the phylogenetic relationships and species status of Pneumocystis,the 5.8S rRNA gene and the internal transcribed spacers(ITS,1 and 2)of Pneumocystis rRNA derived from rat,gerbil and human were amplified,cloned and sequenced.The genetic distance matrix of six Pneumocystis species compared with other fungi like Taphrina and Saccharomyces indicated that the Pneumocystis genus contained multiple species including Pneumocystis from gerbil.The phylogenetic tree also showed that Pneumocystis from human and monkey formed one group and four rodent Pneumocystis formed another group.Among the four members,Pneumocystis wakefieldiae was most closely related to Pneumocystis murina and Pneumocystis carinii,and was least related to gerbil Pneumocystis.
基金This study was supported by grants from the National Natural Science Foundation of China （No. 81301450） and the Education Department of Jilin Province （No. 2014373）.
文摘Objective The objective of this article was to review the current advances in diagnostic methods for Acanthamoeba keratitis （AK）.Data sources Data used in this review were retrieved from PubMed （1970-2013）.The terms ＂Acanthamoeba keratitis＂ and ＂diagnosis＂ were used for the literature search.Study selection Data from published articles regarding AK and diagnosis in clinical trials were identified and reviewed.Results The diagnostic methods for the eight species implicated in AK were reviewed.Among all diagnostic procedures,corneal scraping and smear examination was an essential diagnostic method.Polymerase chain reaction was the most sensitive and accurate detection method.Culturing of Acanthamoeba was a reliable method for final diagnosis of AK.Confocal microscopy to detect Acanthamoeba was also effective,without any invasive procedure,and was helpful in the early diagnosis of AK.Conclusion Clinically,conjunction of various diagnostic methods to diagnose AK was necessary.
基金This work was supported by grants from the State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences （No. GREKF08-07）, the National Natural Science Foundation of China （No. 81301450） and the Jilin Provincial Science and Technology Department of China （No. 20130413035GH）
文摘Background Pyruvate phosphate dikinase （PPDK） reversibly catalyzes the interconversion of phosphoenolpyruvate （PEP） and pyruvic acid,leading to catabolism and adenosine triphosphate （ATP） synthesis or gluconeogenesis and ATP consumption.Molecular modeling of PPDKs from divergent organisms demonstrates that the orientation of the phosphorylatable histidine residue within the central domain of PPDK determines whether this enzyme promotes catabolism or gluconeogenesis.The goal of this study was to determine whether PDDK from Giardia underwent adaptive evolution in order to produce more energy under anaerobic conditions.Methods A total of 123 PPDK sequences from protozoans,proteobacteria,plants,and algae were selected,based upon sequence similarities to Giardia lamblia PPDK and Zea mays PPDK.Three-dimensional （3-D） models were generated for PPDKs from divergent organisms and were used to compare the orientation of the phosphorylatable histidine residue within the central domain of PPDKs.These PPDKs were compared using a maximum-likelihood tree.Results For PPDK from Giardia,as well as from other anaerobic protozoans,the central domain tilted toward the N-terminal nucleotide-binding domain,indicating that this enzyme catalyzed ATP synthesis.Furthermore,the orientation of this central domain was determined by interactions between the N-and C-terminal domains.Phylogenetic analysis of the N-and C-terminal sequences of PPDKs from different species suggested that PPDK has likely undergone adaptive evolution in response to differences in environmental and metabolic conditions.Conclusion These results suggested that PPDK in anaerobic organisms is functionally adapted to generate energy more efficiently in an anaerobic environment.
