Biomedical subjects

Jun Zhu

Publications and source records attributed to Jun Zhu.

At least 91 records · Page 5Linked to original sources

PubMed2005

Effect of glucose-insulin-potassium infusion on mortality in patients with acute ST-segment elevation myocardial infarction: the CREATE-ECLA randomized controlled trial.

CONTEXT: Glucose-insulin-potassium (GIK) infusion is a widely applicable, low-cost therapy that has been postulated to improve mortality in patients with acute ST-segment elevation myocardial infarction (STEMI). Given the potential global importance of GIK infusion, a large, adequately powered randomized trial is required to determine the effect of GIK on mortality in patients with STEMI. OBJECTIVE: To determine the effect of high-dose GIK infusion on mortality in patients with STEMI. DESIGN, SETTING, AND PARTICIPANTS: Randomized controlled trial conducted in 470 centers worldwide among 20,201 patients with STEMI who presented within 12 hours of symptom onset. The mean age of patients was 58.6 years, and evidence-based therapies were commonly used. INTERVENTION: Patients were randomly assigned to receive GIK intravenous infusion for 24 hours plus usual care (n = 10,091) or to receive usual care alone (controls; n = 10,110). MAIN OUTCOME MEASURES: Mortality, cardiac arrest, cardiogenic shock, and reinfarction at 30 days after randomization. RESULTS: At 30 days, 976 control patients (9.7%) and 1004 GIK infusion patients (10.0%) died (hazard ratio [HR], 1.03; 95% confidence interval [CI], 0.95-1.13; P = .45). There were no significant differences in the rates of cardiac arrest (1.5% [151/10 107] in control and 1.4% [139/10,088] in GIK infusion; HR, 0.93; 95% CI, 0.74-1.17; P = .51), cardiogenic shock (6.3% [640/10 107] vs 6.6% [667/10 088]; HR, 1.05; 95% CI, 0.94-1.17; P = .38), or reinfarction (2.4% [246/10,107] vs 2.3% [236/10,088]; HR, 0.98; 95% CI, 0.82-1.17; P = .81). The rates of heart failure at 7 days after randomization were also similar between the groups (16.9% [1711/10,107] vs 17.1% [1721/10,088]; HR, 1.01; 95% CI, 0.95-1.08; P = .72). The lack of benefit of GIK infusion on mortality was consistent in prespecified subgroups, including in those with and without diabetes, in those presenting with and without heart failure, in those presenting early and later after symptom onset, and in those receiving and not receiving reperfusion therapy (thrombolysis or primary percutaneous coronary intervention). CONCLUSION: In this large, international randomized trial, high-dose GIK infusion had a neutral effect on mortality, cardiac arrest, and cardiogenic shock in patients with acute STEMI.

Aged↗

PubMed2005

Requirement for an oxidant in Pd/Cu co-catalyzed terminal alkyne homocoupling to give symmetrical 1,4-disubstituted 1,3-diynes.

Palladium-catalyzed terminal alkyne dimerization, through oxidative homocoupling, is a useful approach to the synthesis of symmetrical 1,4-diynes. Recent investigations have suggested that this reaction might be accomplished in the absence of intentionally added stoichiometric oxidants (to reoxidize Pd(0) to Pd(II)). In this paper, we have fully addressed the question of whether oxygen (or added oxidant) is required to facilitate this process. The presence of a stoichiometric quantity of air (or added oxidant such as I2) is essential for alkyne dimerization. Excess PPh3 inhibits alkyne dimerization to enyne, which only occurs to a significant extent when the reaction is starved of oxidant. Theoretical studies shed more light on the requirement for an oxidant in the homocoupling reaction in order for the process to be theromodynamically favorable. The employment of I2 as the stoichiometric oxidant appears to be the method of choice. The dual role of Cu both in transmetalation of alkynyl units to Pd(II) and in assisting reoxidation of Pd(0) to Pd(II) is suggested.

Journal Article↗

PubMed2005

[Two year follow-up of acute ischemic syndrome without ST elevation].

OBJECTIVE: To analyze the characteristics, treatment, and natural course during two years of the patients with acute coronary ischemic syndrome (ACS) without ST elevation in China as a part of the international multicentre registry of acute ischemic syndrome, Organization to Assess Strategies for Ischemic Syndromes (OASIS). METHODS: 2294 patients with ACS without ST elevation, including unstable angina pectoris and non-Q-wave myocardial infarction, aged 63 +/- 8, 62.3% being males, were registered and observed for 2 years based on informed consent in the northwest, north, and northeast China. The specific clinical protocols for patients were decided by the attending physicians without outside intervention. The patients' clinical characteristics, treatments, major events in hospital, and natural course of disease during the period of two years were recorded by filling in Case Report Forms offered by Canadian Cardiovascular Collaboration. RESULTS: 89.8% of the patients showed abnormal ECG. The most probable clinical diagnosis on admission was unstable angina in 88.5% of the patients and non-Q-wave myocardial infarction in the other 11.5%. 56.2% of the patients had past history of coronary artery disease, and nearly half of them had myocardial infarction. 57.4%, 18.3%, 47.6%, and 7.1% of them had the prior history of hypertension, diabetes, cigarette smoking and stroke respectively. During hospitalization, anti-platelet therapy and nitrate were used in 94.5% and 96.6% of the cases respectively, and 67.5%, 57.4%, and 59.1%t of them took beta-blockers, calcium antagonists and angiotensin-converting enzyme inhibitor (ACEI) respectively simultaneously. The medication rate dropped by 20.2% approximately 50.2% after discharge from hospital. During the two-year follow up the therapeutic rates of anti-platelets, nitrates, beta-blockers, calcium antagonists, and ACEI were 73.8%, 69.4%, 43.9%, 35.8%, and 31.6% respectively. During the 2 years 43.1%, 23.1%, and 8.2% of the patients underwent coronary angiography, percutaneous coronary intervention (PCI), and coronary artery bypass graft surgery (CABG) respectively. The two-year total mortality was 8.0%. The most common causes of death were severe arrhythmias or sudden death with an incidence of 4.3%. The major events were refractory angina, heart failure, new MI, stroke, and major bleeding with incidence rates of 29.4%, 15.4%, 7.9%, 4.8%, and 0.3%, respectively. CONCLUSION: Most patients with acute ischemic syndrome without ST elevation in China are diagnosed as unstable angina. The patients with acute ischemic syndrome are diagnosed as unstable angina mostly in China. More than half of the patients are treated with anti-platelets, nitrates, beta-blockers, calcium antagonists, and ACEI during hospitalization. The medication rate gradually decreases after discharge. The two-year mortality is 8.0%. The most common causes of death include severe arrhythmias and sudden death.

Adult↗

PubMed2005

Genetic control of the opaque-2 gene and background polygenes over some kernel traits in maize (Zea mays L.).

Some kernel traits of agronomical importance in maize are affected by the opaque-2 (o2) gene and background polygenes, which express in different genetic systems such as embryo, endosperm, cytoplasm and maternal plant. A genetic model for seed quantitative traits with the o2 gene effects and polygenic effects as well as their GE interactions was used for protein content, lysine content, oil content and kernel density in maize. The results suggested that the o2 gene was involved in the traits investigated but the effects of the o2 gene were distinctive on various traits. The effects of the o2 gene were large on lysine content and protein content while minor on oil content. There was a substantially wide quantitative variation from polygenes expressing in different genetic systems for the traits evaluated. Significant GE interactions of the o2 gene and background polygenes declared that not only the main effects but also specific expressions depending on environments were responsible for variation of the traits studied. There seemed to have strong maternal heterosis and slight embryo heterosis for kernel density.

DNA-Binding Proteins↗

PubMed2005

A sumoylation site in PML/RARA is essential for leukemic transformation.

Pathogenesis of acute promyelocytic leukemia (APL) has been proposed to involve transcriptional repression through enhanced corepressors binding onto RARA moieties of PML/RARA homodimers. Unexpectedly, we show that the K160 sumoylation site in the PML moiety of PML/RARA is required for efficient immortalization/differentiation arrest ex vivo, implying that RARA homodimerization is insufficient to fully immortalize primary hematopoietic progenitor cells. Similarly, PML/RARAK160R transgenic mice develop myeloproliferative syndromes, but never APL. The Daxx repressor no longer binds PML/RARAK160R, but fusion of these two proteins restores the differentiation block ex vivo. Thus, transcriptional repression dependent on a specific sumoylation site in PML is critical for the APL phenotype, while forced RARA dimerization could control expansion of the myeloid compartment.

Animals↗

PubMed2005

Prevalence of and risk factors for fatty liver in a general population of Shanghai, China.

BACKGROUND/AIMS: To determine the prevalence and risk factors of fatty liver (FL) among Shanghai adults. METHODS: A cross-sectional ultrasonographic survey with randomized multistage stratified cluster sampling was used. RESULTS: The study included 3175 subjects (1218 men) with a mean age of 52 years. FL was found in 661 (20.82%) subjects. After adjustment by age and sex, FL prevalence was found to be 17.29%, and the prevalences of alcoholic, suspected alcoholic and nonalcoholic FL were determined to be 0.79, 1.15 and 15.35%, respectively. Generally, age, body mass index (BMI), waist circumference, blood pressure, and the prevalences of obesity, diabetes, hypertension and dyslipidemia were all significantly higher in FL patients than in controls; In contrast, the levels of high-density-lipoprotein cholesterol (HDL-C), education and physical activity were markedly lower. Multiple regression analyses showed that only nine factors (male, educational level, waist circumference, BMI, HDL-C, triglyceride, fasting plasma glucose, diabetes and hypertension) were closely related to FL. In excessive drinkers, obesity increased the risk for FL by 4.8-fold, but excessive drinking was associated with only a 1.5-fold increased risk in obese subjects. CONCLUSIONS: FL in Shanghai is highly prevalent and mainly related to multiple metabolic disorders.

Adolescent↗

PubMed2005

Clustering gene expression data based on predicted differential effects of GV interaction.

Microarray has become a popular biotechnology in biological and medical research. However, systematic and stochastic variabilities in microarray data are expected and unavoidable, resulting in the problem that the raw measurements have inherent "noise" within microarray experiments. Currently, logarithmic ratios are usually analyzed by various clustering methods directly, which may introduce bias interpretation in identifying groups of genes or samples. In this paper, a statistical method based on mixed model approaches was proposed for microarray data cluster analysis. The underlying rationale of this method is to partition the observed total gene expression level into various variations caused by different factors using an ANOVA model, and to predict the differential effects of GV (gene by variety) interaction using the adjusted unbiased prediction (AUP) method. The predicted GV interaction effects can then be used as the inputs of cluster analysis. We illustrated the application of our method with a gene expression dataset and elucidated the utility of our approach using an external validation.

Algorithms↗

PubMed2005

Opinion: how patients have benefited from mouse models of acute promyelocytic leukaemia.

One of the challenges of studying anticancer therapies is that effects observed in cell lines or mouse models are not always good indicators of clinical trial results. The mouse model of acute promyelocytic leukaemia has bucked this trend, as targeted therapies such as retinoic acid and arsenic induce differentiation and clearance of leukaemia cells in both mice and humans. This mouse model has also provided important mechanistic insights into the combinatorial effects of these agents and has promoted combined therapies that have shown recent success in the clinic.

Animals↗

PubMed2005

Bovine herpesvirus VP22 induces apoptosis in neuroblastoma cells by upregulating the expression ratio of Bax to Bcl-2.

Herpesvirus tegument protein VP22 has been shown to have biotherapeutic potential in tumor gene therapy. Some studies indicate that VP22 may enhance the transfer efficiency of therapeutic proteins by delivering them to more cells while trafficking. Our previous study showed that bovine herpesvirus VP22 (BVP22) enhanced equine herpesvirus thymidine kinase-ganciclovir (Etk-GCV) suicide gene therapy by an unknown intracellular effect. In this study, the interaction between BVP22 and host tumor cells was studied in neuroblastoma NXS2 cells. Cell cycle analysis was performed to determine whether BVP22 possesses biotherapeutic potential by altering the cell cycle, making cells more sensitive to therapeutic genes. As a result, the cell cycle was not affected by the transfection of BVP22 into NXS2 cells. However, cytotoxicity induced by BVP22 was observed in NXS2 cells on the second and third days after transient transfection. Further, analyses of caspase-3 activity and apoptosis suggested that BVP22 induces apoptosis in host tumor cells by upregulating the expression ratio of Bax to Bcl-2.

Animals↗

PubMed2005

CsrA and three redundant small RNAs regulate quorum sensing in Vibrio cholerae.

Bacteria communicate using a process called quorum sensing which involves production, secretion and detection of signalling molecules called autoinducers. Quorum sensing allows populations of bacteria to simultaneously regulate gene expression in response to changes in cell density. The human pathogen, Vibrio cholerae, uses a quorum-sensing circuit composed of parallel systems that transduce information through four redundant regulatory small RNAs (sRNAs) called quorum regulatory RNAs (Qrr) to control the expression of numerous genes, most notably those required for virulence. We show that the VarS/VarA two-component sensory system comprises an additional regulatory input controlling quorum-sensing-dependent gene expression in V. cholerae. VarS/VarA controls transcription of three previously unidentified small regulatory RNAs (sRNAs) that are similar to the sRNAs CsrB and CsrC of Escherichia coli. The three V. cholerae sRNAs, which we name CsrB, CsrC and CsrD, act redundantly to control the activity of the global regulatory protein, CsrA. The VarS/VarA-CsrA/BCD system converges with the V. cholerae quorum-sensing systems to regulate the expression of the Qrr sRNAs, and thus, the entire quorum-sensing regulon.

Adaptation, Physiological↗

PubMed2005

Environmental enrichment decreases cell surface expression of the dopamine transporter in rat medial prefrontal cortex.

Rats raised in an enriched environmental condition (EC) exhibit a decreased (35%) maximal velocity (V(max)) of [3H]dopamine (DA) uptake in medial prefrontal cortex (mPFC) compared with rats raised in an impoverished condition (IC); however, no differences between EC and IC groups in V(max) for [3H]DA uptake were found in nucleus accumbens and striatum. Using biotinylation and immunoblotting techniques, the present study examined whether the brain region-specific decrease in DA transporter (DAT) function is the result of a reduction in DAT cell surface expression. In mPFC, nucleus accumbens and striatum, total DAT immunoreactivity was not different between EC and IC groups. Whereas no differences in cell surface expression of DAT were found in nucleus accumbens and striatum, DAT immunoreactivity in the biotinylated cell surface fraction of mPFC was decreased (39%) in EC compared with IC rats, consistent with the magnitude of the previously observed decrease in V(max) for [3H]DA uptake in mPFC in EC rats. These results suggest that the decrease in DAT cell surface expression in the mPFC may be responsible for decreased DAT function in the mPFC of EC compared with IC rats, and that there is plasticity in the regulatory mechanisms mediating DAT trafficking and function.

Animals↗

PubMed2005

Identification of candidate genes for drought stress tolerance in rice by the integration of a genetic (QTL) map with the rice genome physical map.

Genetic improvement for drought stress tolerance in rice involves the quantitative nature of the trait, which reflects the additive effects of several genetic loci throughout the genome. Yield components and related traits under stressed and well-water conditions were assayed in mapping populations derived from crosses of AzucenaxIR64 and AzucenaxBala. To find the candidate rice genes underlying Quantitative Trait Loci (QTL) in these populations, we conducted in silico analysis of a candidate region flanked by the genetic markers RM212 and RM319 on chromosome 1, proximal to the semi-dwarf (sd1) locus. A total of 175 annotated genes were identified from this region. These included 48 genes annotated by functional homology to known genes, 23 pseudogenes, 24 ab initio predicted genes supported by an alignment match to an EST (Expressed sequence tag) of unknown function, and 80 hypothetical genes predicted solely by ab initio means. Among these, 16 candidate genes could potentially be involved in drought stress response.

Disasters↗

PubMed2005

Evaluation of fertilization-to-planting and fertilization-to-harvest intervals for safe use of noncomposted bovine manure in Wisconsin vegetable production.

Fresh bovine manure was mechanically incorporated into loamy sand and silty clay loam Wisconsin soils in April 2004. At varying fertilization-to-planting intervals, radish, lettuce, and carrot seeds were planted; crops were harvested 90, 100, 110 or 111, and 120 days after manure application. As an indicator of potential contamination with fecal pathogens, levels of Escherichia coli in the manure-fertilized soil and presence of E. coli on harvested vegetables were monitored. From initial levels of 4.0 to 4.2 log CFU/g, E. coli levels in both manure-fertilized soils decreased by 2.4 to 2.5 log CFU/g during the first 7 weeks. However, E. coli was consistently detected from enriched soil samples through week 17, perhaps as a result of contamination by birds and other wildlife. In the higher clay silty clay loam soil, the fertilization-to-planting interval affected the prevalence of E. coli on lettuce but not on radishes and carrots. Root crop contamination was consistent across different fertilization-to-harvest intervals in silty clay loam, including the National Organic Program minimum fertilization-to-harvest interval of 120 days. However, lettuce contamination in silty clay loam was significantly (P < 0.10) affected by fertilization-to-harvest interval. Increasing the fertilization-to-planting interval in the lower clay loamy sand soil decreased the prevalence of E. coli on root crops. The fertilization-to-harvest interval had no clear effect on vegetable contamination in loamy sand. Overall, these results do not provide grounds for reducing the National Organic Program minimum fertilization-to-harvest interval from the current 120-day standard.

Agriculture↗

PubMed2005

Fate of Staphylococcus aureus on vacuum-packaged ready-to-eat meat products stored at 21 degrees C.

The U.S. Department of Agriculture has established standards for the composition and shelf stability of various ready-to-eat meat products. These standards may include product pH, moisture:protein ratio, and water activity (aw) values. It is unclear how closely these standards are based on the potential for pathogen growth or toxin production. Because the vacuum packaging used on most ready-to-eat meat products inhibits mold, Staphylococcus aureus is the pathogen most likely to grow on products with reduced aw and increased percentage of water-phase salt. In this study, 34 samples of various ready-to-eat meat products were inoculated with a three-strain mixture of S. aureus, vacuum packaged, and stored at 21 degrees C for 4 weeks. S. aureus numbers decreased by 1.1 to 5.6 log CFU on fermented products (pH < or = 5.1) with a wide range of salt concentrations and moisture content. Similarly, S. aureus numbers decreased by 3.2 to 4.5 log CFU on dried nonacidified jerky (aw < or = 0.82; moisture:protein ratio of < or =0.8). Products that were not fermented or dried clearly supported S. aureus growth and cannot be considered shelf stable. The product pH and moisture:protein ratio were the two compositional factors most highly correlated (R2 = 0.84) with S. aureus survival and growth for the types of products tested, but pH and aw or pH and percentage of water-phase salt also may provide useful predictive guidance (R2 = 0.81 and 0.77, respectively).

Colony Count, Microbial↗

PubMed2005

[Epidemiological survey of prevalence of fatty liver and its risk factors in a general adult population of Shanghai].

OBJECTIVE: To investigate the prevalence and major risk factors of fatty liver among adult residents in Shanghai. METHODS: A cross-sectional survey with multiple-stage stratified cluster and random sampling was performed. All residents aged 16 and above were invited to participate in the survey; they came from four communities of Yangpu District and Pudong New District. Questionnaire, physical examination, serum lipid-profile, and 75 gram oral glucose tolerance test and ultrasonographic examination of liver were undertaken. Analysis of data was performed through SPSS 11.0 for Windows statistical package. RESULTS: A total of 3175 residents took part in the survey, which was 75% of adult residents of the investigated communities and 2.26/10 000 of Shanghai municipal residents. Of the 3175, 1218 were males and 1957 were females. The mean age of the participants was 52.4+/-15.1 years and ranged from 16 to 88 years. Fatty liver was detected with ultrasound examination in 661 participants (20.82%), among which 3.48% had alcoholic fatty liver, 4.08% had suspected alcoholic fatty liver, and 92.43% had nonalcoholic fatty liver. The age-adjusted, sex-adjusted prevalence of fatty liver in Shanghai adult residents was 17.29%, the prevalence of alcoholic fatty liver, suspicious alcoholic fatty liver, and nonalcoholic fatty liver in Shanghai adult residents were 0.79%, 1.15%, and 15.35%, respectively. The prevalence of fatty liver was increased with aging in males and in females. Among participants younger than 50 years old, the prevalence of fatty liver in males was significantly higher than that in females, but in participants older than 50 years the case was just the opposite, higher in females. The mean age (years), body mass index (BMI), waist circumference, blood pressure, fasting and two hour serum glucose level, triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and the presence of obesity, diabetes mellitus, hypertension, dyslipidemia, and gallstones in the fatty liver group was significantly higher than those in the group without fatty liver, but the high-density lipoprotein cholesterol (HDL-C) level and the educational level were both lower in the fatty liver group. Logistic regression analysis demonstrated that the prevalence of fatty liver was only positively correlated to nine risk factors, including male sex, educational level, waist circumference, BMI, fasting glucose level, HDL-C, TG, hypertension and diabetes mellitus. In heavy drinkers, obesity increased the risk for fatty liver by 4.8-fold, but heavy drinking only increased the risk for fatty liver 1.5-fold (95% CI 0.9-2.6, P=0.1685). CONCLUSION: There is a high prevalence of fatty liver among adult residents in Shanghai, and nonalcoholic fatty liver is the major type. Metabolic disorders such as obesity and diabetes mellitus, hypertension and hyperlipidemia are more closely associated with fatty liver than heavy drinking in Shanghai.

Adolescent↗

PubMed2005

[Risk factors of sudden death and death from arrhythmia in patients with non-ST elevation acute coronary syndromes in China].

OBJECTIVE: To analyze the relationship between sudden death and death from arrhythmia and multiple risk factors in patients with non-ST elevation acute coronary syndromes in two years of follow-up in China. METHODS: This study was a part of an international multicentre registry-Organization to Assess Strategies for Ischemic Syndromes (OASIS). The patients admitted to the hospital with non-ST elevation acute coronary syndrome were enrolled. No particular intervention was given for the treatment. All patients had been followed-up for two years. The patients' clinical characteristics, therapeutic regimes and major events during hospitalization and two years' follow-up period were recorded by filling in Case Report Forms according to the protocol offered by Canadian Cardiovascular Collaboration. Cox regression model was used to analyze the association with the most common causes of death and multiple factors recorded. RESULTS: From April 1999 to December 2001, 2294 cases were enrolled in 38 hospitals in China nationwide. Among them 2188 patients two years follow-up was accomplished. The mean age of the patients was (62.8+/-8.1) years. Male gender was dominant (62.3%). The clinical diagnosis at admission was unstable angina in 88.5% of the patients and non Q-wave myocardial infarction(MI) in the remaining 11.5%. The mortality was 7.6% with total deaths of 174 by the end of 24-month follow up. The most common cause of death was severe arrhythmias or sudden death (92 cases, 52.9%). More than 70 factors were analyzed by Cox regression model in order to determine which were the predominant factors of death. Major risk factors that predisposed to death were: number of episodes of MI during follow-up period, re-MI within 24 hours during hospitalization, heart failure during hospitalization, previous history of MI, recurrent angina pectoris during hospitalization, the duration of hospitalization, and patient age. Protective factors that reduced the chance of death were: the frequency of using nitrate, frequency of taking anti-platelet medicine or beta-blocker during follow-up period. CONCLUSION: In China, the most common cause of death in patients with non-ST elevation acute coronary syndromes is severe arrhythmias or sudden death, and it is related with the severity of coronary artery disease and the age of patients in majority of cases. Some factors that influence survival are similar to those established by previous evidence based medicine.

Acute Coronary Syndrome↗

PubMed2005

[Secular trends of hypospadias in Chinese perinatals].

OBJECTIVE: To investigate the secular trends in the prevalence rate of hypospadias in Chinese perinatals and explore its possible influencing factors. METHODS: Data were taken from Chinese Birth Defects Monitoring Network, a hospital-based congenital anomalies registry system. All live or still births at or beyond 28 weeks of gestation were assessed within 7 days after delivery in the period from 1987 to 2001. RESULTS: 1999 cases of hypospadias were identified among 3,769,464 male births, the crude prevalence rate being 5.30 per 10,000 births. And an increasing secular trend was observed both in urban and rural areas. In recent years, an increase in rate of hypospadias was found in coastal provinces and inland provinces, but not in remote border provinces. Faster increase was seen in urban areas and coastal areas, compared with that in rural areas and inland areas respectively. CONCLUSION: The prevalence rates of hypospadias in Chinese perinatals from 1987 to 2001 showed an upward tendency.

China↗

PubMed2005

[Study on AHL-like quorum signals in Mesorhizobium huakuii].

Quorum sensing is a mechanism used by single-cell bacteria to monitor their population density and control a variety of physiological functions in a cell-density-dependent manner. An ultrasensitive quorum signal acyl-homoserine lactone (AHL) detecting Agrobacterium tumefaciens strain, which strongly overproduces quorum-sensing regulator TraR and was proved to be able to detect AHLs at nano-molar concentration, was used to detect the production of AHLs in three Mesorhizobium huakuii strains. We showed that AHLs were produced in these strains with some variations. We also found that elevating of medium pH during cell growth greatly affected the stability of AHL signals. This study paved the way of further studying the relationship between quorum sensing and symbiotic nitrogen fixation of the M. huakuii strains.

4-Butyrolactone↗