期刊文献+
共找到6,650篇文章
< 1 2 250 >
每页显示 20 50 100
Cumulative effects of excess high-normal alanine aminotransferase levels in relation to new-onset metabolic dysfunction-associated fatty liver disease in China 被引量:6
1
作者 Jing-Feng Chen Zhuo-Qing Wu +5 位作者 Hao-Shuang Liu Su Yan You-Xiang Wang Miao Xing Xiao-Qin Song Su-Ying Ding 《World Journal of Gastroenterology》 SCIE CAS 2024年第10期1346-1357,共12页
BACKGROUND Within the normal range,elevated alanine aminotransferase(ALT)levels are associated with an increased risk of metabolic dysfunction-associated fatty liver disease(MAFLD).AIM To investigate the associations ... BACKGROUND Within the normal range,elevated alanine aminotransferase(ALT)levels are associated with an increased risk of metabolic dysfunction-associated fatty liver disease(MAFLD).AIM To investigate the associations between repeated high-normal ALT measurements and the risk of new-onset MAFLD prospectively.METHODS A cohort of 3553 participants followed for four consecutive health examinations over 4 years was selected.The incidence rate,cumulative times,and equally and unequally weighted cumulative effects of excess high-normal ALT levels(ehALT)were measured.Cox proportional hazards regression was used to analyse the association between the cumulative effects of ehALT and the risk of new-onset MAFLD.RESULTS A total of 83.13%of participants with MAFLD had normal ALT levels.The incidence rate of MAFLD showed a linear increasing trend in the cumulative ehALT group.Compared with those in the low-normal ALT group,the multivariate adjusted hazard ratios of the equally and unequally weighted cumulative effects of ehALT were 1.651[95%confidence interval(CI):1.199-2.273]and 1.535(95%CI:1.119-2.106)in the third quartile and 1.616(95%CI:1.162-2.246)and 1.580(95%CI:1.155-2.162)in the fourth quartile,respectively.CONCLUSION Most participants with MAFLD had normal ALT levels.Long-term high-normal ALT levels were associated with a cumulative increased risk of new-onset MAFLD. 展开更多
关键词 Metabolic dysfunction-associated fatty liver disease High-normal alanine aminotransferase level Cumulative effect Cox proportional hazards regression Cohort study
下载PDF
Alanine aminotransferase predicts incident steatotic liver disease of metabolic etiology: Long life to the old biomarker! 被引量:1
2
作者 Amedeo Lonardo 《World Journal of Gastroenterology》 SCIE CAS 2024年第24期3016-3021,共6页
Alanine aminotransferase(ALT)serum levels increase because of hepatocellular damage.Metabolic dysfunction-associated fatty liver disease(MAFLD),which identifies steatotic liver disease(SLD)associated with≥2 metabolic... Alanine aminotransferase(ALT)serum levels increase because of hepatocellular damage.Metabolic dysfunction-associated fatty liver disease(MAFLD),which identifies steatotic liver disease(SLD)associated with≥2 metabolic abnormalities,has prominent sexual differences.The Metabolic Syndrome defines a cluster comprising abdominal obesity,altered glucose metabolism,dyslipidemia,and hypertension.Male sex,body mass index,glucose,lipids,ferritin,hypertension,and age independently predict ALT levels among blood donors.Over the last few decades,the reference range of ALT levels has been animatedly debated owing to attempts to update sex-specific reference ranges.With this backset,Chen et al have recently published a study which has two main findings.First,>80%of indi-viduals with MAFLD had normal ALT levels.Second,there was a linear increa-sing trend in the association between cumulative excess high-normal ALT levels and the rate of incident MAFLD.This study has biologically credible findings.However,it inaccurately considered sex differences in the MAFLD arena.Therefore,future studies on SLD owing to metabolic dysfunction should adopt locally determined and prospectively validated reference ranges of ALT and carefully consider sex differences in liver enzymes and MAFLD pathobiology. 展开更多
关键词 alanine aminotransferase BIOMARKER History of medicine Metabolic dysfunction-associated fatty liver disease METABOLISM Nonalcoholic fatty liver disease Reference range Sex differences Steatotic liver disease
下载PDF
Supplementation of alanine improves biomass accumulation and lipid production of Chlorella pyrenoidosa by increasing the respiratory and metabolic processes
3
作者 Yongfu LI Tianze ZHAO +2 位作者 Wei SUN Ruiwen GAO Guangyuan MA 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第2期570-579,共10页
The function of exogenous alanine(Ala)in regulating biomass accumulation,lipid production,photosynthesis,and respiration in Chlorella pyrenoidosa was studied.Result shows that the supplementation of Ala increased C.py... The function of exogenous alanine(Ala)in regulating biomass accumulation,lipid production,photosynthesis,and respiration in Chlorella pyrenoidosa was studied.Result shows that the supplementation of Ala increased C.pyrenoidosa biomass and lipid production in an 8-d batch culture.The concentration of 10 mmol/L of Ala was optimum and increased the microalgal cell biomass and lipid content by 39.3%and 21.4%,respectively,compared with that in the control(0-mmol/L Ala).Ala supplementation reduced photosynthetic activity while boosting respiratory activity and pyruvate levels,indicating that C.pyrenoidosa used exogenous Ala for biomass accumulation through the respiratory metabolic process.The accelerated respiratory metabolism due to Ala supplementation elevated the substrate pool and improved the lipogenic gene expression,promoting lipid production at last.This study provided a novel method for increasing biomass accumulation and lipid production and elucidated the role of Ala in regulating lipid production. 展开更多
关键词 alanine Chlorella pyrenoidosa LIPID RESPIRATION lipogenic gene
下载PDF
Effects of excess high-normal alanine aminotransferase levels in relation to new-onset metabolic dysfunction-associated fatty liver disease:Clinical implications
4
作者 Giovanna McGinty Robert Przemioslo 《World Journal of Gastroenterology》 SCIE CAS 2024年第27期3264-3267,共4页
In this editorial,we comment on the article by Chen et al recently published in 2024.We focus the debate on whether reducing the upper limit of normal of alanine aminotransferase(ALT)would effectively identify cases o... In this editorial,we comment on the article by Chen et al recently published in 2024.We focus the debate on whether reducing the upper limit of normal of alanine aminotransferase(ALT)would effectively identify cases of fibrosis in metabolic-dysfunction associated fatty liver disease(MAFLD).This is important given the increasing prevalence of MAFLD and obesity globally.Currently,a suitable screening test to identify patients in the general population does not exist and most patients are screened after the finding of an abnormal ALT.The authors of this paper challenge the idea of what a normal ALT is and whether that threshold should be lowered,particularly as their study found that 83.12%of their study population with a diagnosis of MAFLD had a normal ALT.The main advantages of screening would be to identify patients and provide intervention early,the mainstay of this being changing modifiable risk factors and monitoring for liver fibrosis.However,there is not enough suitable therapeutic options available as of yet although this is likely to change in the coming years with more targets for therapy being discovered.Semaglutide is one example of this which has demonstrated benefit with an acceptable side effect profile for those patients with MAFLD and obesity,although studies have not yet shown a significant improvement in fibrosis regression.It would also require a huge amount of resource if a reduced ALT level alone was used as criteria;it is more likely that current scoring systems such as fibrosis-4 may be amended to represent this additional risk.Currently,there is not a good argument to recommend wide-spread screening with a reduced ALT level as this is unlikely to be cost-effective.This is compounded by the fact that there is a significant heterogeneity in what is considered a normal ALT between laboratories.Although studies previously have suggested a more pragmatic approach in screening those over the age of 60,this is likely to change with the increasing incidence of obesity within the younger age groups.The main message from this study is that those who have hypercholesterolemia and high body metabolic index should have these risk factors modified to maintain a lower level of ALT to reduce the risk of progression to fibrosis and cirrhosis. 展开更多
关键词 alanine aminotransferase Metabolic-dysfunction associated fatty liver disease Metabolic syndrome Fibrosis Cirrhosis Semaglutide
下载PDF
Alanine aminotransferase as a risk marker for new-onset metabolic dysfunction-associated fatty liver disease
5
作者 Di Wang Bing-Yan Zhou +2 位作者 Lei Xiang Xu-Yong Chen Jie-Xiong Feng 《World Journal of Gastroenterology》 SCIE CAS 2024年第25期3132-3139,共8页
In this editorial,we comment on the article by Chen et al.Metabolic dysfunction-associated fatty liver disease(MAFLD)is a global public health burden whose incidence has risen concurrently with overweight and obesity.... In this editorial,we comment on the article by Chen et al.Metabolic dysfunction-associated fatty liver disease(MAFLD)is a global public health burden whose incidence has risen concurrently with overweight and obesity.Given its detri-mental health impact,early identification of at-risk individuals is crucial.MAFLD diagnosis is based on evidence of hepatic steatosis indicated by liver biopsy,imaging,or blood biomarkers,and one of the following conditions:Overweight/obesity,type 2 diabetes mellitus,or metabolic dysregulation.However,in large-scale epidemiological studies,liver biopsies are not feasible.The application of techniques such as ultrasonography,computed tomography,magnetic resonance imaging,and magnetic resonance spectroscopy is restricted by their limited sensitivity,low effectiveness,high costs,and need for specialized software.Blood biomarkers offer several advantages,particularly in large-scale epidemiological studies or clinical scenarios where traditional imaging techniques are impractical.Analysis of cumulative effects of excess high-normal blood alanine aminotrans-ferase(ALT)levels of blood ALT levels could facilitate identification of at-risk patients who might not be detected through conventional imaging methods.Accordingly,investigating the utility of blood biomarkers in MAFLD should enhance early detection and monitoring,enabling timely inter-vention and management and improving patient outcomes. 展开更多
关键词 Nonalcoholic fatty liver disease Metabolic dysfunction-associated fatty liver disease alanine aminotransferase SCREENING Risk marker
下载PDF
Predictive value of serum alanine aminotransferase for fatty liver associated with metabolic dysfunction
6
作者 Wen-Xiu Liu Lei Liu 《World Journal of Hepatology》 2024年第7期990-994,共5页
In this editorial,we offer commentary on the article published by Chen et al in a recent issue of the World Journal of Gastroenterology(2024;30:1346-1357).The study highlights a noteworthy association between persiste... In this editorial,we offer commentary on the article published by Chen et al in a recent issue of the World Journal of Gastroenterology(2024;30:1346-1357).The study highlights a noteworthy association between persistently elevated,yet highnormal levels of alanine transaminase(ALT)and an escalated cumulative risk of developing metabolic dysfunction-associated fatty liver disease(MAFLD).MAFLD has emerged as a globally prevalent chronic liver condition,whose incidence is steadily rising in parallel with improvements in living standards.Left unchecked,MAFLD can progress from hepatic steatosis to liver fibrosis,cirrhosis,and even hepatocellular carcinoma,underscoring the importance of early screening and diagnosis.ALT is widely recognized as a reliable biomarker for assessing the extent of hepatocellular damage.While ALT levels demonstrate a significant correlation with the severity of fatty liver disease,they lack specificity.The article by Chen et al contributes to our understanding of the development of MAFLD by investigating the long-term implications of high-normal ALT levels.Their findings suggest that sustained elevation within the normal range is linked to an increased likelihood of developing MAFLD,emphasizing the need for closer monitoring and potential intervention in such cases. 展开更多
关键词 Metabolic dysfunction-associated fatty liver disease alanine aminotransferase Upper reference limits FIBROSIS Metabolic dysfunction-associated steatohepatitis CIRRHOSIS
下载PDF
Degradation and biocompatibility of one-step electrodeposited magnesium thioctic acid/magnesium hydroxide hybrid coatings on ZE21B alloys for cardiovascular stents
7
作者 Zhao-Qi Zhang Bing-Zhi Li +5 位作者 Pei-Duo Tong Shao-Kang Guan Li Wang Zheng-Hui Qiu Cun-Guo Lin Rong-Chang Zeng 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第1期120-138,共19页
Constructing a functional hybrid coating appears to be a promising strategy for addressing the poor corrosion resistance and insufficient endothelialization of Mg-based stents.Nevertheless,the steps for preparing comp... Constructing a functional hybrid coating appears to be a promising strategy for addressing the poor corrosion resistance and insufficient endothelialization of Mg-based stents.Nevertheless,the steps for preparing composite coatings are usually complicated and time-consuming.Herein,a novel composite coating,composed of bioactive magnesium thioctic acid(MTA)layer formed by deposition and corrosion-resistant magnesium hydroxide(Mg(OH)_(2))layer grown in situ,is simply fabricated on ZE21B alloys via one-step electrodeposition.Scanning electron microscopy(SEM)shows that the electrodeposited coating has a compact and uniform structure.And the high adhesion of the MTA/Mg(OH)_(2)hybrid coating is also confirmed by the micro-scratch test.Electrochemical test,scanning kelvin probe(SKP),and hydrogen evolution measurement indicate that the hybrid coating effectively reduces the degradation rate of Mg substrates.Haemocompatibility experiment and cell culture trial detect that the composite coating is of fine biocompatibility.Finally,the preparation mechanism of MTA/Mg(OH)_(2)hybrid coatings is discussed and proposed.This coating shows a great potential application for cardiovascular stents. 展开更多
关键词 Magnesium alloy Corrosion resistance Hybrid coating ENDOTHELIALIZATION biocompatibility
下载PDF
Enhancing the anti-corrosion performance and biocompatibility of AZ91D Mg alloy by applying roughness pretreatment and coating with in-situ Mg(OH)_(2)/Mg-Al LDH
8
作者 Zexi Shao Pubo Li +3 位作者 Chao Zhang Bintao Wu Chan Tang Mangmang Gao 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第6期2520-2533,共14页
Corrosion-resistant and biocompatible films were fabricated on AZ91D Mg alloy substrates by varying their roughness levels using met-allographic preparation and subsequent hydrothermal procedures.The coated films comp... Corrosion-resistant and biocompatible films were fabricated on AZ91D Mg alloy substrates by varying their roughness levels using met-allographic preparation and subsequent hydrothermal procedures.The coated films comprised a mixed structure of Mg(OH)_(2)and Mg-Al layered double hydroxides(LDH)and exhibited excellent compactness.Coating film thickness increased with decreasing surface roughness.Corrosion resistance was evaluated using potentiodynamic polarization and electrochemical impedance spectroscopy.Metallographic pretreat-ment influenced the chemical activity of the Mg alloy surface and helped modulate the dissolution rate of the Mg_(17)Al_(12)phase during the hydrothermal procedure.With decreasing roughness of the Mg substrate,the Al^(3+)concentration gradually increased,accelerating the in-situ formation of the Mg(OH)_(2)/LDH composite coating and improving its crystallinity.A thick and dense Mg(OH)_(2)/LDH coating was synthesized on the Mg substrate with the least roughness,substantially improving the corrosion resistance of the AZ91D alloy.The lowest corrosion current density((5.73±2.75)×10^(−8)A·cm^(−2))was achieved,which was approximately three orders of magnitude less than that of bare AZ91D.Moreover,the coating demonstrated biocompatibility with no evident cytotoxicity,cellular damage,and hemolytic phenomena.This study provides an effective method for preparing coatings on Mg alloy surfaces with excellent corrosion resistance and biocompatibility. 展开更多
关键词 Magnesium alloy ROUGHNESS Corrosion resistance Layered double hydroxides biocompatibility
下载PDF
The influence of yttrium and manganese additions on the degradation and biocompatibility of magnesium-zinc-based alloys:In vitro and in vivo studies
9
作者 Lei Shi Yang Yan +3 位作者 Chun-sheng Shao Kun Yu Bo Zhang Liang-jian Chen 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第2期608-624,共17页
The repair and regeneration of bone defects are highly challenging orthopedic problems.Recently,Mg-based implants have gained popularity due to their unique biodegradation and elastic modulus similar to that of human ... The repair and regeneration of bone defects are highly challenging orthopedic problems.Recently,Mg-based implants have gained popularity due to their unique biodegradation and elastic modulus similar to that of human bone.The aim of our study is to develop a magnesium alloy with a controllable degradation that can closely match bone tissue to help injuries heal in vivo and avoid cytotoxicity caused by a sudden increase in ion concentration.In this study,we prepared and modified Mg-3Zn,Mg-3Zn-1Y,and Mg-2Zn-1Mn by hot extrusion,and used Mg-2.5Y-2.5Nd was as a control.We then investigated the effect of additions of Y and Mn on alloys'properties.Our results show that Mn and Y can improve not only compression strength but also corrosion resistance.The alloy Mg-2Zn-1Mn demonstrated good cytocompatibility in vitro,and for this reason we selected it for implantation in vivo.The degraded Mg-2Zn-1Mn implanted a bone defect area did not cause obvious rejection and inflammatory reaction,and the degradation products left no signs of damage to the heart,liver,kidney,or brain.Furthermore,we find that Mg-2Zn-1Mn can promote an osteoinductive response in vivo and the formation of bone regeneration. 展开更多
关键词 Magnesium alloy BIODEGRADATION biocompatibility Bone regeneration Bone defect repair
下载PDF
Discovering Cathodic Biocompatibility for Aqueous Zn–MnO_(2) Battery:An Integrating Biomass Carbon Strategy
10
作者 Wei Lv Zilei Shen +10 位作者 Xudong Li Jingwen Meng Weijie Yang Fang Ding Xing Ju Feng Ye Yiming Li Xuefeng Lyu Miaomiao Wang Yonglan Tian Chao Xu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第6期111-126,共16页
Developing high-performance aqueous Zn-ion batteries from sustainable biomass becomes increasingly vital for large-scale energy storage in the foreseeable future.Therefore,γ-MnO_(2) uniformly loaded on N-doped carbon... Developing high-performance aqueous Zn-ion batteries from sustainable biomass becomes increasingly vital for large-scale energy storage in the foreseeable future.Therefore,γ-MnO_(2) uniformly loaded on N-doped carbon derived from grapefruit peel is successfully fabricated in this work,and particularly the composite cathode with carbon carrier quality percentage of 20 wt%delivers the specific capacity of 391.2 mAh g^(−1)at 0.1 A g^(−1),outstanding cyclic stability of 92.17%after 3000 cycles at 5 A g^(−1),and remarkable energy density of 553.12 Wh kg^(−1) together with superior coulombic efficiency of~100%.Additionally,the cathodic biosafety is further explored specifically through in vitro cell toxicity experiments,which verifies its tremendous potential in the application of clinical medicine.Besides,Zinc ion energy storage mechanism of the cathode is mainly discussed from the aspects of Jahn–Teller effect and Mn domains distribution combined with theoretical analysis and experimental data.Thus,a novel perspective of the conversion from biomass waste to biocompatible Mn-based cathode is successfully developed. 展开更多
关键词 Aqueous Zn-ion batteries biocompatibility Jahn-Teller effect Mn domains γ-MnO_(2)
下载PDF
Lowering the threshold of alanine aminotransferase for enhanced identification of significant hepatic injury in chronic hepatitis B patients 被引量:1
11
作者 Hong-Sheng Yu Hao Jiang +5 位作者 Ming-Kai Li Bi-Lan Yang Abdukyamu Smayi Jian-Ning Chen Bin Wu Yi-Dong Yang 《World Journal of Gastroenterology》 SCIE CAS 2023年第35期5166-5177,共12页
BACKGROUND The clinical and histological features of chronic hepatitis B(CHB)patients who fall into the"grey zone(GZ)"and do not fit into conventional natural phases are unclear.AIM To explore the impact of ... BACKGROUND The clinical and histological features of chronic hepatitis B(CHB)patients who fall into the"grey zone(GZ)"and do not fit into conventional natural phases are unclear.AIM To explore the impact of varying the threshold of alanine aminotransferase(ALT)levels in identifying significant liver injury among GZ patients.METHODS This retrospective analysis involved a cohort of 1617 adult patients diagnosed with CHB who underwent liver biopsy.The clinical phases of CHB patients were determined based on the European Association for the Study of the Liver 2017 Clinical Practice Guidelines.GZ CHB patients were classified into four groups:GZ-A(HBeAg positive,normal ALT levels,and HBV DNA≤10^(7) IU/mL),GZ-B(HBeAg positive,elevated ALT levels,and HBV DNA<10^(4) or>10^(7) IU/mL),GZC(HBeAg negative,normal ALT levels,and HBV DNA≥2000 IU/mL),and GZ-D(HBeAg negative,elevated ALT levels,and HBV DNA≤2000 IU/mL).Significant hepatic injury(SHI)was defined as the presence of notable liver inflammation(≥G2)and/or significant fibrosis(≥S2).RESULTS The results showed that 50.22%of patients were classified as GZ,and 63.7%of GZ patients developed SHI.The study also found that lowering the ALT treatment thresholds to the American Association for the Study of Liver Diseases 2018 treatment criteria(35 U/L for men and 25 U/L for women)can more accurately identify patients with significant liver damage in the GZ phases.In total,the proportion of patients with ALT≤40 U/L who required antiviral therapy was 64.86%[(221+294)/794].When we lowered the ALT treatment threshold to the new criteria(30 U/L for men and 19 U/L for women),the same outcome was revealed,and the proportion of patients with ALT≤40 U/L who required antiviral therapy was 75.44%[(401+198)/794].Additionally,the proportion of SHI was 49.1%in patients under 30 years old and increased to 55.3%in patients over 30 years old(P=0.136).CONCLUSION These findings suggest the importance of redefining the natural phases of CHB and using new ALT treatment thresholds for better diagnosis and management of CHB patients in the GZ phases. 展开更多
关键词 Chronic hepatitis B Grey zone Indeterminate phase alanine aminotransferase Antiviral therapy
下载PDF
Lower alanine aminotransferase levels are associated with increased all-cause and cardiovascular mortality in nonalcoholic fatty liver patients
12
作者 Jia-Rui Zheng Zi-Long Wang +2 位作者 Su-Zhen Jiang Hong-Song Chen Bo Feng 《World Journal of Hepatology》 2023年第6期813-825,共13页
BACKGROUND Serum alanine aminotransferase(ALT) levels are often considered a marker to evaluate liver disease and its severity.AIM To investigate the association between ALT levels and all-cause and cause-specific mor... BACKGROUND Serum alanine aminotransferase(ALT) levels are often considered a marker to evaluate liver disease and its severity.AIM To investigate the association between ALT levels and all-cause and cause-specific mortality in patients with nonalcoholic fatty liver disease(NAFLD).METHODS The Third National Health and Nutrition Examination Survey(NHANES-Ⅲ) from 1988 to 1994 and NHANES-Ⅲ-related mortality data from 2019 onward were used to obtain the necessary data for the study. NAFLD was defined as hepatic steatosis, as diagnosed by ultrasound, with no other liver diseases. ALT levels were categorized into four groups according to the different recommended upper limits of normal(ULN) in men and women: < 0.5 ULN, 0.5-1 ULN, 1-2 ULN, and ≥ 2 ULN. The hazard ratios for all-cause mortality and cause-specific mortality were analyzed using the Cox proportional hazard model.RESULTS Multivariate logistic regression analysis demonstrated that the odds ratio of NAFLD correlated positively with increased serum ALT levels. In patients with NAFLD, all-cause mortality and cardiovascular mortality were the highest when ALT was < 0.5 ULN, yet cancer-related mortality was the highest when ALT was ≥ 2 ULN. The same results could be found in both men and women. Univariate analysis showed that severe NAFLD with normal ALT levels had the highest allcause and cause-specific mortality, but the difference was not statistically significant after adjustment for age and multivariate factors.CONCLUSION The risk of NAFLD was positively correlated with ALT level, but all-cause and cardiovascular mortality were the highest when ALT was < 0.5 ULN. Regardless of the severity of NAFLD, normal or lower ALT levels were associated with higher mortality than elevated ALT levels. Clinicians should be aware that high ALT levels indicate liver injury, but low ALT levels are associated with a higher risk of death. 展开更多
关键词 Non-alcoholic fatty liver disease alanine aminotransferase MORTALITY NHANES-Ⅲ
下载PDF
Alanine racemase is essential for the growth and interspecies competitiveness of Streptococcus mutans 被引量:3
13
作者 Yuan Wei Wei Qiu +8 位作者 Xue-Dong Zhou Xin Zheng Ke-Ke Zhang Shi-Da Wang Yu-Qing Li Lei Cheng Ji-Yao Li Xin Xu Ming-Yun Li 《International Journal of Oral Science》 SCIE CAS CSCD 2016年第4期231-238,共8页
D-alanine (D-Ala) is an essential amino acid that has a key role in bacterial unique enzyme that interconverts L-alanine and D-alanine in most bacteria, antimicrobial drug development. Streptococcus mutans is a majo... D-alanine (D-Ala) is an essential amino acid that has a key role in bacterial unique enzyme that interconverts L-alanine and D-alanine in most bacteria, antimicrobial drug development. Streptococcus mutans is a major causative cell wall synthesis. Alanine racemase (Air) is a making this enzyme a potential target for factor of dental caries. The factors involved in the survival, virulence and interspecies interactions of S. mutans could be exploited as potential targets for caries control. The current study aimed to investigate the physiological role of Air in S. mutans. We constructed air mutant strain of S. mutans and evaluated its phenotypic traits and interspecies competitiveness compared with the wild-type strain. We found that air deletion was lethal to S. mutans. A minimal supplement of D-Ala (150 pg.mL- 1) was required for the optimal growth of the air mutant. The depletion of D-alanine in the growth medium resulted in cell wall perforation and cell lysis in the air mutant strain. We also determined the compromised competitiveness of the air mutant strain relative to the wild-type S. mutans against other oral streptococci (S. sanguinis or S. gordonil~, demonstrated using either conditioned medium assays or dual-species fluorescent in situ hybridization analysis. Given the importance and necessity of air to the growth and competitiveness of S. mutans, Air may represent a promising target to modulate the cariogenicity of oral biofilms and to benefit the management of dental caries. 展开更多
关键词 alanine racemase BIOFILM D-alanine dental caries Streptococcus mutans
下载PDF
Preparation and characterization of composite microspheres of nano zinc ferrite/poly(D,L-lactide-co-alanine) 被引量:3
14
作者 曹雷健 周勤华 +4 位作者 谷俐 沈红霞 李清华 兰平 方燕 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第2期360-365,共6页
Magnetic nano zinc ferrite fliuds were synthesized using an improved liquid phase chemical method, which would be used to replace tradditional iron oxides magnetic material. A novel copolymer (PLAA) with D, L-lacti... Magnetic nano zinc ferrite fliuds were synthesized using an improved liquid phase chemical method, which would be used to replace tradditional iron oxides magnetic material. A novel copolymer (PLAA) with D, L-lactide (D, L-LA) and alanine was synthesized using stannous octoate as initiator. Magnetic polymer microspheres were fabricated with nano zinc ferrite fluid coated with alanine modified poly lactide. These as-prepared zinc ferrite fluids, modified poly lactide and magnetic composites, were characterized with X-ray diffraction diffractometer, FT-IR spectrometer, nuclear magnetic resonance spectrometer, scanning electron microscope, transmission electron microscope, vibrating sample magnetometer, and thermogravimetric analyzer. The results demonstrate that the as-prepared zinc ferrite is spinel type of ZnFe2O4 nano crystals with particle size of 20-45 nm and magnetization of 32×10^-3 A.m2. Alanine is copolymerized with lactide, and the prepared composite magnetic microsphere is coated with the modified polylactide, with mass fraction of 45.5% of PLA, particle size ranging from 80-300 nm, and magnetization of 10.6×10^-3 A·m^2, which suggests ZnFe2O4 enjoys a stable magnetization after being coated by polymer. 展开更多
关键词 zinc ferrite alanine POLYLACTIDE magnetic composite microsphere
下载PDF
In vitro corrosion and biocompatibility of phosphating modified WE43 magnesium alloy 被引量:5
15
作者 叶成红 奚廷斐 +2 位作者 郑玉峰 王淑琴 李扬德 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第4期996-1001,共6页
Phospahting coated WE43 magnesium alloy was prepared by an immersion method. The microstructure, corrosion resistance and biocompatibility of the coated alloy were investigated. Scanning electron microscopy (SEM) an... Phospahting coated WE43 magnesium alloy was prepared by an immersion method. The microstructure, corrosion resistance and biocompatibility of the coated alloy were investigated. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to examine the microstructure and the composition of the coated alloy. The corrosion resistance was studied by means of potentiodynamic polarization method and the biocompatibility of the surface modified WE43 alloy was evaluated by (3-(4,5)-Dimethylthiazol-2, yl)-2,5-diphenyltetrazolium bromide (MTT) and hemolysis test. The results show that the phosphating coating can enhance the corrosion resistance of WE43 alloy and can be a good candidate to increase the biocompatibility of WE43 alloy. 展开更多
关键词 magnesium alloy phosphating coating corrosion resistance biocompatibility
下载PDF
Diagnostic value of FIB-4, aspartate aminotransferaseto-platelet ratio index and liver stiffness measurement in hepatitis B virus-infected patients with persistently normal alanine aminotransferase 被引量:20
16
作者 You-Wen Tan Xing-Bei Zhou +2 位作者 Yun Ye Cong He Guo-Hong Ge 《World Journal of Gastroenterology》 SCIE CAS 2017年第31期5746-5754,共9页
AIM To assess the diagnostic value of FIB-4, aspartate aminotransferase-to-platelet ratio index(APRI), and liver stiffness measurement(LSM) in patients with hepatitis B virus infection who have persistently normal ala... AIM To assess the diagnostic value of FIB-4, aspartate aminotransferase-to-platelet ratio index(APRI), and liver stiffness measurement(LSM) in patients with hepatitis B virus infection who have persistently normal alanine transaminase(PNALT).METHODS We enrolled 245 patients with chronic hepatitis B: 95 in PNALT group, 86 in intermittently elevated alanine transaminase(PIALT1) group [alanine transaminase(ALT) within 1-2 × upper limit of normal value(ULN)], and 64 in PIALT2 group(ALT > 2 × ULN). All the patients received a percutaneous liver biopsy guided by ultrasonography. LSM, biochemical tests, and complete blood cell counts were performed.RESULTS The pathological examination revealed moderate inflammatory necrosis ratios of 16.81%(16/95), 32.56%(28/86), and 45.31%(28/64), and moderate liverfibrosis of 24.2%(23/95), 33.72%(29/86), and 43.75%(28/64) in the PNALT, PIALT1, and PIALT2 groups, respectively. The degrees of inflammation and liver fibrosis were significantly higher in the PIALT groups than in the PNALT group(P < 0.05). No significant difference was found in the areas under the curve(AUCs) between APRI and FIB-4 in the PNALT group; however, significant differences were found between APRI and LSM, and between FIB-4 and LSM in the PNALT group(P < 0.05 for both). In the PIALT1 and PIALT2 groups, no significant difference(P > 0.05) was found in AUCs for all comparisons(P > 0.05 for all). In the overall patients, a significant difference in the AUCs was found only between LSM and APRI(P < 0.05).CONCLUSION APRI and FIB-4 are not the ideal noninvasive hepatic fibrosis markers for PNALT patients. LSM is superior to APRI and FIB-4 in PNALT patients because of the influence of liver inflammation and necrosis. 展开更多
关键词 Liver stiffness measurement Hepatitis B virus FIB-4 Aspartate aminotransferase-to-platelet ratio index NORMAL alanine aminotransferase
下载PDF
Interactions and Biological Activity of Rare Earth Perchlorate Complexes with Alanine and Imidazole 被引量:5
17
作者 HE Shui yang, CHEN Jun li, ZHANG Wei ping, LIU Xiang rong, SONG Di sheng ( Chemistry Department, North west University, Xi′an 710069, China) 《Journal of Rare Earths》 SCIE EI CAS CSCD 2001年第1期66-66,共1页
The interactions of nine rare earth perchlorate complexes with alanine and imidazole were studied in methanol. The general formulae of these compounds are RE(Ala) 2Im(ClO 4) 3· n H 2O(RE=Ce, Pr, Nd, Sm, Eu,... The interactions of nine rare earth perchlorate complexes with alanine and imidazole were studied in methanol. The general formulae of these compounds are RE(Ala) 2Im(ClO 4) 3· n H 2O(RE=Ce, Pr, Nd, Sm, Eu, Gd, Tb, Yb) and La(Ala) 3Im(ClO 4) 3·H 2O, respectively. The composition and structure of the prepared compounds were determined by the chemical analysis, elemental analysis, IR spectroscopy, UV, FS spectroscopy, X ray powder diffraction, 1H NMR and solubility. The thermal decomposition processes of these complexes were studied on the basis of TG DTG. The preliminary bioassay shows that the compounds have a remarkable bacteriostasis effect on nine varieties of microbe. 展开更多
关键词 rare earths alanine IMIDAZOLE biology activity
下载PDF
Effects of chitosan coating on biocompatibility of Mg-6%Zn-10%Ca_3(PO_4)_2 implant 被引量:1
18
作者 赵俊 陈良建 +5 位作者 余琨 陈畅 戴翌龙 乔雪岩 颜阳 余志明 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第3期824-831,共8页
A Mg?6%Zn?10%Ca3(PO4)2 composite with a chitosan coating was prepared to study its in vivo biodegradation properties. The chitosan dissolved in a 0.2% acetic acid solution was applied on the surface of Mg?6%Zn?10%Ca3(... A Mg?6%Zn?10%Ca3(PO4)2 composite with a chitosan coating was prepared to study its in vivo biodegradation properties. The chitosan dissolved in a 0.2% acetic acid solution was applied on the surface of Mg?6%Zn?10%Ca3(PO4)2 composite specimens and solidified at 60 °C for 30 min to form the coating. The cytotoxicity evaluation of chitosan coated specimens is at level 0, which indicates that such coating is safe for cellular applications. The in vivotests of chitosan coated composite show that the concentration of metal ions from the composite measured in the venous blood of Zelanian rabbits is less than that from the uncoated composite specimens. The chitosan coating impedes the in vivo degradation of the composite after surgery. The in vivo testing also indicates that the chitosan coated composite is harmless to important visceral organs, including the heart, kidneys and liver of the rabbits. The new bone formation surrounding the chitosan coated composite implant shows that the composite improves the concrescence of the bone tissues. And the chitosan coating is an effective corrosion resistant layer that reduces the hydrogen release of the implant composite, thereby decreasing the subcutaneous gas bubbles formed. 展开更多
关键词 biocompatibility magnesium composite CHITOSAN CYTOTOXICITY
下载PDF
Non-ALT biomarkers for markedly abnormal liver histology among Chinese persistently normal alanine aminotransferase-chronic hepatitis B patients 被引量:24
19
作者 Jin-Lin Cheng Xiao-Ling Wang +3 位作者 Shi-Gui Yang Hong Zhao Jing-Jing Wu Lan-Juan Li 《World Journal of Gastroenterology》 SCIE CAS 2017年第15期2802-2810,共9页
AIM To determine incidence and clinical biomarkers of marked necroinflammation and fibrosis characteristics among chronic hepatitis B (CHB) patients with persistently normal alanine aminotransferase (PNALT). METHODS L... AIM To determine incidence and clinical biomarkers of marked necroinflammation and fibrosis characteristics among chronic hepatitis B (CHB) patients with persistently normal alanine aminotransferase (PNALT). METHODS Liver biopsy was performed on 115 CHB patients with PNALT. Necroinflammation and fibrosis were graded by the Knodell histologic activity index and the Ishak fibrosis score, respectively. Correlations between the available clinical parameters and necroinflammation and fibrosis were analysed. RESULTS Marked necroinflammation (Knodell activity index >= 7) and fibrosis (Ishak fibrosis score >= 3) were found in 36.5% and 15.5% of CHB patients with PNALT, respectively. Following a univariate logistic regression analysis, multiple logistic regression analysis indicated that aspartate transaminase (AST) (AUROC = 0.852, cut-off value = 22.5 U/L) serves as an independent predictor of notable liver inflammation, while platelet (PLT) count (AUROC = 0.905, cut-off value = 171.5 x 10(9)/ml) and gamma-glutamyl transpeptidase (GGT) (AUROC = 0.909, cut-off value = 21.5 U/L) level serve as independent predictors of notable liver fibrosis. CONCLUSION A considerable proportion of marked histological abnormalities existed in our cohort, who will benefit from optimal therapeutic strategies administered according to predictive indication by AST, PLT and GGT levels. 展开更多
关键词 Chronic hepatitis B Liver biopsy Normal alanine aminotransferase NECROINFLAMMATION Hepatic fibrosis
下载PDF
Elevated alanine aminotransferase activity is not associated with dyslipidemias,but related to insulin resistance and higher disease grades in non-diabetic non-alcoholic fatty liver disease 被引量:5
20
作者 Mohammad Ebrahim Ghamar-Chehreh Mohsen Amini +6 位作者 Hossein Khedmat Seyed Moayed Alavian Fatemeh Daraei Reza Mohtashami Reza Hadi Bent-Al-Hoda Beyram Saeed Taheri 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2012年第9期702-706,共5页
Objective:To explore demographic and metabolic factors associated with increased alanine aminotransferase(ALT)activity in non-diabetic non-alcoholic fatty liver disease(NAFLD)patients.Methods:Overall 372 patients who ... Objective:To explore demographic and metabolic factors associated with increased alanine aminotransferase(ALT)activity in non-diabetic non-alcoholic fatty liver disease(NAFLD)patients.Methods:Overall 372 patients who consecutively attended to Gastroenterology Clinic of Baqiyatallah University of Medical Sciences,Tehran,Iran awere diagnosed as NAFLD entered into analysis.Exclusion criteria were having diabetes mellitus and fasting blood glucose over126 mg/dL,active hepatitis B virus infection,having hepatitis C virus positive serology,and to be under corticosteroid therapy.ALT levels were considered pathologically high when it was over30 IU/L for men and over 19 IU/L for women.Results:Bivariate analyses using t test and chisquare test showed that patients with pathologically augmented ALT levels had significantly higher NAFLD grades in their ultrasonographic evaluations(P=0.003).Moreover,these patients represented significantly higher homeostatic model assessment levels(P=0.003),levels of serum insulin(P=0.002),fasting blood glucose(P<0.001),and uric acid(P=0.02).The prevalence of insulin resistance was also higher in patients with increased serum ALT concentrations.Multifactorial logistic regression models showed that ultrasonographic grading of NAFLD(P=0.027)and insulin resistance(P=0.013)were the only variables significantly associated with abnormal ALT levels.Conclusions:This study shows that the associations of increased ALT serum levels in NAFLD patients are different from what are supposed before.By excluding diabetic patients from our population,we find that increased ALT levels are not associated with dyslipidemias but are independently associated with insulin resistance and NAFLD grading on ultrasonographic evaluations.Further studies are needed to confirm our results. 展开更多
关键词 alanine AMINOTRANSFERASE Non-alcoholic fatty liver DISEASE INSULIN resistance Fasting blood glucose Ultrasonographic evaluation Diabetes mellitus Metabolic factor Serum INSULIN Dyslipidemia
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部