Transformation mechanism of ions on different waters in alpine region.

The study investigates transformation mechanism of ions on different waters in Alpine region through analyzed the hydrochemical characteristics of the major ions of precipitation, glacier and snow meltwater, supra-permafrost water and river water in permafrost regions in the Tibetan Plateau under climate warming. The results showed that, The relation between recharge and discharge was the major ways for ionic transformation of each water body. Precipitation and glacier and snow meltwater are the main input sources for ionic transformation, and river water is the final output source. Different water bodies had different ionic concentrations and different hydrochemical types. However, different water bodies in different months (from June to September) also had different hydrochemical types. The water - rock interaction, reactions for ions, dilution effect and other effect for ions played an important role in the process of ion transformation. The increasing of temperature would lead to the accelerated melting of glaciers, permafrost and snow in the alpine regions, so the amount of supra-permafrost water and glacier and snow meltwater will increase, which leads to the increase of runoff. Meanwhile, the increase of temperature makes evaporation stronger. The strong of evaporation will accelerate the transformation of liquid water to gaseous water. Moreover, ion translation and water conversion are synchronous. Accordingly, ions are also accelerating transformation in the process of accelerated transformation of water body. Climate change is not only the main driving force for multiphase water transformation, but also the main driving force for the ion transformation of various water bodies.

The sources of supra-permafrost water and its hydrological effect based on stable isotopes in the third pole region.

The sources of supra-permafrost water and its hydrological effects were studied, based on the presence of stable isotopes in 562 samples collected in different ablation periods from the source regions of the Yangtze River. The δ18O (δD and d-excess) values for the initial ablation, ablation, and end ablation periods were -10.18‰ (-71.39‰ and 10.08‰), -12.14‰ (-85.58‰ and 11.51‰) and -11.50‰ (-78.75‰ and 13.23‰), respectively. The order of the slopes for the supra-permafrost water evaporation lines from the different ablation periods was initial ablation (IA) > ablation (A) > end ablation (EA). An anti-altitude effect is documented here, for a specific altitude range, in what is believed to be the first record of such an occurrence. Outside of that range, clear altitude effects were apparent. We have been able to show that supra-permafrost water was mainly recharged by atmospheric precipitation, ground ice, and glacier and snow meltwater, in the initial ablation and end ablation periods, and contributions from glacier and snow meltwater were mainly concentrated in higher altitude regions. In contrast, in the ablation period, supra-permafrost water was mainly recharged by atmospheric precipitation and ground ice. The contributions of precipitation to supra-permafrost water were 78.79%, 85.47%, and 82.99% in the initial ablation, ablation, and end ablation periods, respectively. The contributions of ground ice to the supra-permafrost water were 14.05%, 14.53%, and 11.94%, respectively, while contributions of glacier and snow meltwater were 7.15% and 5.07% in the initial and end ablation period. For the initial ablation, ablation, and end ablation periods, contributions from atmospheric precipitation to the supra-permafrost water were 85.47%, 86.86%, and 86.84%, while contributions from ground ice were 14.53%, 13.14% and 13.16%, respectively.

[Diversity study of arbuscular mycorrhizal fungi of Coptis deltoidea].

OBJECTIVE: To investigate the resources and distribution of Arbuscular Mycorrhizal Fungi (AMF) in rhizosphere of Coptis deltoidea. METHODS: The colonization situation of AMF of Coptis deltoidea were detected by acid fuchsin staining and then calculated the colonization rate. AMF fungal spores were obtained by Wet-screening method and then classified and identified by their morphological characteristics and histochemical staining method. RESULTS: Coptis deltoidea and AMF could engender the mycorrhiza. Colonization rates were different in different producing areas and ranged from 23. 3% to 34.4%. Thirty species of AMF belonging in 6 genera were found, including 17 species of the Acaulospora, 7 of the Glomus, 2 of the Gigaspora, 1 of the Entrophospora, 1 of the Paraglomus and 2 of the Archaeospora were isolated from rhizosphere of Coptis deltoidea. Acaulospora and Glomus were the dominant genera and the AMF species of genuine producing regions in Hongya county was the most diversiform among the six areas. CONCLUSION: Coptis deltoidea is a kind of nutrition type of mycorrhiza plant. The rich diversity of AMF of Coptis deltoidea in producing areas make the AMF is a biological resource of significant application prospects in enlarging yield and non-pollution production.

[A prospective cohort study on the influence of high doses of herbs for clearing heat and resolving stasis on survival rates in patients with hepatitis B-related acute-on-chronic liver failure].

BACKGROUND: Hepatitis B-related acute-on-chronic liver failure (ACLF) is a severe clinical syndrome characterized by jaundice, coagulopathy, ascites and hepatic encephalopathy and with a high mortality rate of 65% to 93%. It involves significant ethical issues when a randomized, double-blinded, placebo-controlled clinical study is conducted to such a serious disease. Therefore, a prospective cohort study design was utilized to explore a new treatment modality of applying integrated traditional Chinese and Western medicine. OBJECTIVE: To evaluate the efficacy, safety and recent survival rates of high-dose herbs with the function of clearing heat and resolving stasis, named Qingre Huayu, in patients with hepatitis B-related ACLF with heat toxin stagnation syndrome. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS: A matched, prospective cohort study was conducted. Participants who met the inclusion criteria were recruited from the Department of Infectious Diseases, Affiliated Hospital of Chengdu University of Traditional Chinese Medicine. Patients were assigned to either an integrated medicine group or a Western medicine group according to their own preference and received either a regime of classic Western medical treatment (control group) or a regime of classic Western medical treatment plus Qingre Huayu herbs (treatment group). The regimes were conducted for 12 weeks. MAIN OUTCOME MEASURES: Survival rates of non-liver transplantation patients were evaluated after 12-week treatment. The levels of total bilirubin (TBiL), albumin (ALB), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and prothrombin activity (PTA) were detected at baseline and weeks 4, 8 and 12. Scores of traditional Chinese medicine (TCM) syndrome and complications were evaluated at baseline and study completion. Adverse events were recorded. RESULTS: All patients were followed up to the deadline for this study. There were 21 cases (31.8%) who died in the treatment group (n=66) and 19 cases (59.4%) in the control group (n=32). Significant difference (X(2)=6.775, P<0.01) was found in comparing the survival and death rates between the two groups by X(2) test. At 12 weeks, mean survival time of the two groups was 69.9 and 47.2 d respectively; cumulative survival rate of patients in the treatment group was higher than that of patients in the control group (P<0.01). Levels of TBiL, ALT, AST, ALB and PTA at weeks 4, 8 and 12 in the treatment group were superior to those in the control group with statistical significance (P<0.01 or P<0.05). In comparison of the TCM syndrome scores at week 12, the average score of the TCM syndrome of the treatment group (n=45) was 7.52±2.41, lower than 18.34±4.36 of the control group (n=13), and the difference was significant (t=8.784, P<0.01). Complication incidences after 12 weeks of treatment were statistically different between the treatment group (n=45) and the control group (n=13) by X(2) test (P<0.05 or P<0.01). Incidence rates of ascites, infection and hepatic encephalopathy accounted for 22.22%(10/45) and 69.23% (9/13), 8.89% (4/45) and 53.85% (7/13), and 11.11% (5/45) and 46.15% (6/13) in the two groups respectively. The incidence rates of adverse events in the treatment group and the control group were 0.00% and 12.50% respectively and the difference was statistically significant (X(2)=5.705, P<0.05). No drug-related adverse events were found in blood, urine and stool routine tests, renal function test and electrocardiography. CONCLUSION: High doses of Qingre Huayu herbs can significantly improve liver function and coagulation function, reduce complications, and reduce mortality in patients with hepatitis B-related ACLF.

[The correlation between expression level of femB and resistance phenotype of methicillin-resistant Staphylococcus aureus (MRSA)].

OBJECTIVE: To investigate the correlation between the phenotype and expression level of femB of Staphylococcus aureus (MRSA), to discuss the mechanism of different phenotypes in methicillin-resistant Staphylococcus aureus. METHODS: The minimal inhibitory concentrations (MICs) of oxacillin against 71 clinical isolates of Staphylococcus aureus were determined by agar dilution method according to NCCLS. The production of beta-lactamase was identified by Cefinase paper strip method. The isolation rate of beta-lactamase-producing strains was counted and the correlation between the resistance phenotype and isolation rate of beta-lactamase was analysed by statistics. Real time fluorescent quantitative PCR was used to quantify the mRNA expression of femB of non-beta-lactamase-producing strains. RESULTS: The resistance rate of 71 Staphylococcus aureus to oxacillin was 66.20% (47/71), the isolation rate of beta-lactamase-producing MSSA strains was 58.3%,and that of strains of high- and low-level resistance to oxacillin were 63.15% and 55.56%. The standard curve was performed by series dilution of the heterogeneous resistant strain BB270, and the amount of femB-specific mRNA in strain BB270 was set to be 1. The calculated femB amounts in MSSA strains were from 0.4830-3.3636, while the amounts were from 0.4204-3.3636 in low-level MRSA strains, and 0.0718-16.0000 in high-level MRSA strains. There were no difference in the level of femB among MSSA, high-level MRSA and low-level MRSA. CONCLUSION: The expression level of femB may not be related to the resistance of non-beta-lactamase-producting Staphylococcus aureus to methicillin.

[Preliminary study on genotyping of Mycobacterium tuberculosis strains isolated in Tibet with multiple locus variable numbers of tandem repeats].

OBJECTIVE: To investigate the application of the multiple locus variable numbers of tandem repeats (MLVA) in genotype Mycobacterium tuberculosis strains isolated from Tibet, and to understand the characteristics of genotype and distribution. METHODS: 217 M. tuberculosis strains were collected from six regions of Tibet. Twenty tandem repeats loci in the total genome of M. tuberculosis (MTB) were analyzed by PCR and agarose gel electrophoresis method. The characteristics on polymorphism of DNA fingerprinting of 217 MTB strains were analyzed with BioNumerics 3.0 software. RESULTS: 217 M. tuberculosis strains detected with 20 MLVA loci were classified to 19 genotypes with 87.6% of the stains belonging to Beijing genotype and the other 18 genotypes were scattered,accounted for 1.38% and 0.92% strains, respectively. Beijing genotype was not significantly associated with the resistance to all of the four drugs and BCG vaccination. CONCLUSION: It is concluded that the strains of MTB isolated in Tibet present definite polymorphism and most of the epidemic strains belonged to Beijing family genotype and MTB genotyping. The Beijing genotype was not recognized as the one transferred from some of the drug resistance strains or from BCG vaccination. Being a fast and simple technique, MLVA method, seemed a better molecular typing method and could be used for genotyping in M. tuberculosis and monitoring pathogen.

[Study on the correlation between resistance phenotype and expression level of femA of Staphylococcus aureus].

OBJECTIVE: To detect the expression level of femA of Staphylococcus aureus strains with different phenotype. METHODS: 15 strains of the non-beta-lactamase-producing clinical isolates with different phenotype by agar dilution and by nitrocephin paper strip method were chosen as the object of test, in addition to 4 donative strains (BB270, BB308, BB586, COL). Total RNA were extracted and analysed by agarose gel electrophoresis. Real time fluorescent quantitative PCR was performed to quantify the expression of femA gene. The expression level of femA of BB270 was set to be standard(100%). RESULTS: The expressions of femA were observed in all the tested strains. The amount of femA-specific mRNA in the mutant strain BB308 was approximately 37.82% and that of stain BB586 was 240.50%, homogeneous resistant strain COL was 862.61%. The amounts in MSSA strains were from 0.00353% to 29.92%, that in low-level MRSA strains were from 0.00554% to 310%, otherwise that in high-level MRSA strains were from 13.88% to 55000%, which were different among these groups. There was no significant difference in amount of femA-mRNA between MSSA and low-level MRSA strains (P1 = 0.83) but marked between high-level MRSA and low-level MRSA/MSSA strains (P2 = 0.006, P3 = 0.01)). CONCLUSION: Expression level of femA in high-level MRSA was significant higher than that in low-level MRSA and MSSA. femA was essential for the expression of high-level methicillin resistance in MRSA.

[A study on the mechanism of drug resistance in Staphylococcus aureus].

OBJECTIVE: To inquire into the mechanism of drug resistance in Staphylococcus aureus. METHODS: A total of 198 strains of Staphylococcus aureus were isolated from the samples sent to the Clinical Laboratory of Microbiology,West China Hospital. The resistance of Staphylococcus aureus to Methicillin was assayed with agar dilution. Staphylococcus aureus mecA gene was measured by PCR assay and beta-lactamase was detected by Nitrocephin. RESULTS: The rate of resistance to methicillin was 64.65% in 198 strains of Staphylococcus aureus; 118 strains of methicillin-resistant staphylococcus aureus(MRSA) were found to have high level resistance in 128 MRSA;10 strains of MRSA were found to have low level resistance; 41(58.57%) strains of methicillin-sensitive Staphylococcus aureus (MSSA) expressed beta-lactamase; 2 Staphylococcus aureus had mecA among them; 67 Staphylococcus aureus expressed beta-lactamase in high level resistance, 63(53.39%)Staphylococcus aureus expressed beta-lactamase in high level resistance, among them, 5 Staphylococcus aureus had mecA; 40.00% MRSA expressed beta-lactamase in low level resistance, 55 MRSA did not express beta-lactamase in high level resistance, which had all mecA; 9 Staphylococcus aureus did not express beta-lactamase in low level resistance, among them, 5 Staphylococcus aureus had mecA. The difference in expression of beta-lactamase was statistically significant between MSSA and MRSA; MRSA(53.39%) was lower than MSSA (58.57%); the other differences were not significant. The difference in having mecA was statistically significant between MRSA(having high resistant level and no expression of beta-lactamase) and the others; MRSA had higher mecA than did the others. CONCLUSION: The resistance in Staphylococcus aureus mainly involved two mechanisms: the expression of beta-lactamase and the expression of mecA.

[Effect of polylactic acid on the proliferation and differentiation of osteoblast-like cells].

OBJECTIVE: To assess the effects of polylactic acid (PLA) on the proliferation and differentiation of UMR-106 osteoblast-like cells. METHODS: The ultrastructures of the surface of untreated and pretreated PLA films were observed under electron microscope. UMR-106 osteoblast-like cells were cultured with PLA film which was untreated or treated by some special agents together, then the cells morphology was observed, and methyl thiazolyl tetrazolium (MTT) assay and alkaline phosphatase (ALP) analysis were performed to detect the Tiny distinction between the untreated film and pretreated film was proliferation and differentiation. RESULTS: found under electron microscope. The cells of material group were seen to have grown in clusters, compared with control. And the proportion of polygon and star cells was higher in the material group than in the control, The values measured by ALP and MTT in the material group were lower than control, yet the distinction was undulatory in different phase of test. The difference in cells morphology between the pretreatment group and control was observed only in the first three days. The values measured by ALP and MTT in the pretreatment group were almost consistent with those in control, and even slightly higher than control sometimes. CONCLUSION: PLA film does not have permanent inhibitory effect on the proliferation and differentiation of osteoblast-like cells. On the contrary, the treated PLA film may accelerate the proliferation and differentiation of cells to some extent. So, PLA film may have the potential for use as a good tissue-engineering frame in the treatment of bone disorders.

[Studies on the nucleotides sequences of extended-spectrum-beta-lactamases encoding genes of Escherichia coli and Klebsiella pneumoniae and the related molecular evolution].

OBJECTIVE: To identify TEM-type and SHV-type ESBLs encoding genes of ESBLs-producing Klebsiella pneumoniae and Escherichia coli isolated from clinical species in West China Hospital of Sichuan University and study the molecular evolution of the ESBLs. METHODS: The nucleotide sequences of TEM-type and SHV-type ESBLs encoding genes amplified by PCR were detected by automatic sequencer, and the subtypes of the encoding genes were determined by Blastx searching. The molecular evolution of ESBLs was studied by means of bioinformatics. RESULTS: In this study, the subtypes of ESBLs were SHV-2 and TEM-19, the distribution of silent mutation in ten bla(SHV-2) was identical, and that of two bla(TEM-19) was the same; the distribution of silent mutation of bla(TEM-19) was the same as that of bla(TEM-1). The distribution of silent mutation of bla(SHV-2) observed here was different from that observed in other countries. CONCLUSION: SHV-2 was the main ESBLs in this study. The bla(SHV-2) and bla(TEM-19) in this study originated from the same transferable variants respectively. The prevalent SHV-2 in different countries resulted from convergent evolution. It seems possible that the bla(TEM-19) identified by this study might originate directly from the transferable bla(TEM-1) identified in this study.