Exploring the diagnostic value of CLR and CPR in differentiating Kawasaki disease from other infectious diseases based on clinical predictive modeling

Background

Kawasaki disease (KD) is an important cause of acquired heart disease in children and adolescents worldwide. KD and infectious diseases can be easily confused when the clinical presentation is inadequate or atypical, leading to misdiagnosis or underdiagnosis of KD. In turn, misdiagnosis or underdiagnosis of KD can lead to delayed use of intravenous immunoglobulin (IVIG), increasing the risk of drug resistance and coronary artery lesions (CAL).

Objectives

The purpose of this study was to develop a predictive model for identifying KD and infectious diseases in children in the hope of helping pediatricians develop timely and accurate treatment plans.

Methods

The data Patients diagnosed with KD from January 2018 to July 2022 in Shenzhen Longgang District Maternity & Child Healthcare Hospital, and children diagnosed with infectious diseases in the same period will be included in this study as controls. We collected demographic information, clinical presentation, and laboratory data on KD before receiving IVIG treatment. All statistical analyses were performed using R-4.2.1 (https://www.rproject.org/). Logistic regression and Least Absolute Shrinkage with Selection Operator (LASSO) regression analyses were used to build predictive models. Calibration curves and C-index were used to validate the accuracy of the prediction models.

Results

A total of 1,377 children were enrolled in this study, 187 patients with KD were included in the KD group and 1,190 children with infectious diseases were included in the infected group. We identified 15 variables as independent risk factors for KD by LASSO analysis. Then by logistic regression we identified 7 variables for the construction of nomogram including white blood cell (WBC), Monocyte (MO), erythrocyte sedimentation rate (ESR), alanine transaminase (ALT), albumin (ALB), C-reactive protein to procalcitonin ratio (CPR) and C-reactive protein to lymphocyte ratio (CLR). The calibration curve and C-index of 0.969 (95% confidence interval: 0.960-0.978) validated the model accuracy.

Conclusion

Our predictive model can be used to discriminate KD from infectious diseases. Using this predictive model, it may be possible to provide an early determination of the use of IVIG and the application of antibiotics as soon as possible.

[Quantitative proteomics and bioinformatics analyses of human coronary artery endothelial cell injury induced by Kawasaki disease]

OBJECTIVE

To study the biomarkers for human coronary artery endothelial cell (HCAEC) injury induced by Kawasaki disease (KD) using isobaric tags for relative and absolute quantitation (iTRAQ) proteomics.

METHODS

HCAECs cultured with the serum of children with KD were used as the KD group, and those cultured with the serum of healthy children was used as the healthy control group. The iTRAQ technique was used to measure the expression of proteins in two groups. The data on proteins were analyzed by bioinformatics. Western blot was used for the validation of protein markers.

RESULTS

A total of 518 significantly differentially expressed proteins were identified (with an absolute value of difference fold of >1.2, P<0.05). The gene ontology analysis showed that the differentially expressed proteins were significantly enriched in biological processes (including cellular processes, metabolic processes, and biological regulation), cellular components (including cell parts, cells, and organelles), and molecular functions (including binding, catalytic activity, and molecular function regulators). The KEGG analysis showed that the proteins were significantly enriched in the signaling pathways of ribosomes, PI3K-Akt signaling pathway, and transcriptional dysregulation in cancer. The PPI network showed that the top 9 protein markers in relation density were PWP2, MCM4, MCM7, MCM5, MCM3, MCM2, SLD5, HDAC2, and MCM6, which were selected as the protein markers for coronary endothelial injury in KD. Western blot showed that the KD group had significantly lower expression levels of the protein markers HDAC2, PWP2, and MCM2 than the healthy control group (P<0.05).

CONCLUSIONS

The serum of children with KD significantly changes the protein expression pattern of HCAECs and affects the signaling pathways associated with the cardiovascular system, which provides a new basis for the pathophysiological mechanism and therapeutic targets of KD.

Rapid and Sensitive Detection of Salmonella in Chickens Using Loop-Mediated Isothermal Amplification Combined with a Lateral Flow Dipstick

Salmonellosis is a highly contagious bacterial disease that threatens both human and poultry health. Tests that can detect Salmonella in the field are urgently required to facilitate disease control and for epidemiological investigations. Here, we combined loop-mediated isothermal amplification (LAMP) with a chromatographic lateral flow dipstick (LFD) to rapidly and accurately detect Salmonella. LAMP primers were designed to target the Salmonella invA gene. LAMP conditions were optimized by adjusting the ratio of inner to outer primers, MgSO₄ concentration, dNTP mix concentration, amplification temperature, and amplification time. We evaluated the specificity of our novel LAMP-LFD method using six Salmonella species and six related non-Salmonella strains. All six of the Salmonella strains, but none of the non-Salmonella strains, were amplified. LAMP-LFD was sensitive enough to detect concentrations of Salmonella enterica subsp. enterica serovar Pullorum genomic DNA as low as 89 fg/µl, which is 1,000 times more sensitive than conventional PCR. When artificially contaminated feed samples were analyzed, LAMP-LFD was also more sensitive than PCR. Finally, LAMP-LFD gave no false positives across 350 chicken anal swabs. Therefore, our novel LAMP-LFD assay was highly sensitive, specific, convenient, and fast, making it a valuable tool for the early diagnosis and monitoring of Salmonella infection in chickens.

Transthoracic Echocardiographic Evaluation of Pulmonary Valve Anomalies in Pediatric Patients

The pulmonary valve normally consists of 3 leaflets supported in a semilunar fashion within the sinuses of the pulmonary trunk. Pulmonary leaflet malformations, such as congenital single pulmonary cusp absence, bicuspid pulmonary valve, and quadricuspid pulmonary valve anomalies, as well as pulmonary valve commissural fusion, are seldom identified preoperatively on echocardiography. In this study, we report on 5 children with different types of pulmonary valve malformations diagnosed by transthoracic echocardiography.

[Role of ash2 (absent, small, or homeotic)-like and Jumonji domain-containing protein 3 on histone methylation of interferon-gamma gene and their associations with vascular damage of Kawasaki disease]

Objective: To investigate the impacts of ash2 (absent, small, or homeotic)-like (Ash2L) and Jumonji domain-containing protein 3 (Jmjd3) on histone methylation of interferon-gamma(IFN-γ) gene and association with vascular damage of Kawasaki disease (KD) in acute phase. Methods: This study was performed among 36 children with KD in acute phase (KD group) and 28 age-matched health children (control group), who were treated or underwent physical examination in our hospital between February 2015 and June 2016. Patients were further divided into KD groups with or without coronary artery lesions (KD-CAL(+) , 16 cases; KD-CAL(-), 20 cases). All KD patients were treated with intravenous immunoglobulin. The proportion of type 1 helper T(Th1) cells and protein levels of IFN-γ, T-box expressed in T cells(T-bet), phosphorylated signal transducer and activator of transcription 1(pSTAT1) and phosphorylated signal transducer and activator of transcription 4(pSTAT4) were analyzed by flow cytometry.Chromatin immunoprecipitation was performed to determine histone methylation (histone H3 tri-methyl K4(H3K4me3), histone H3 tri-methyl K27(H3K27me3)) and binding levels of Ash2L, Jmjd3 and Ezh2 associated with IFN-γ in CD4(+) T cells. Quantitative real-time PCR was used to determine mRNA levels of IFN-γ, interferon γ receptor 1(IFN-γR1), interferon γ receptor 2(IFN-γR2), interleukin 12 receptor subunit beta 1(IL-12Rβ1), interleukin 12 receptor subunit beta 2(IL-12Rβ2), interleukin 18 receptor subunit beta α(IL-18Rα), interleukin 18 receptor subunit beta β(IL-18Rβ), tumor necrosis factor receptor 1(TNFR1), toll-like receptor 4(TLR4), receptor interacting serine/threonine kinase 1(RIP-1) and myeloid differentiation primary response gene 88(MyD88) in CD4(+) T cells. Plasma concentrations of IFN-γ, interleukin 12(IL-12), interleukin 18(IL-18) and tumor necrosis factor α(TNF-α) were measured by enzyme-linked Immunosorbent assay. Results: (1)The proportion of Th1 and its protein level of IFN-γ were significantly higher in KD group than those in control group and higher in KD-CAL(+) group than in KD-CAL(-) group (all P<0.05), and lower after treatment than before treatment (all P<0.05). (2)Compared with control group, mRNA level of IFN-γ and IFN-γ-associating H3K4me3 was increased, while level of IFN-γ associating H3K27me3 in CD4(+) T cells was reduced in KD group (all P<0.05), which resulted in a higher rate of H3K4me3/H3K27me3 (P<0.05) in KD group, which was positively correlated with IFN-γ mRNA in KD group(r=0.55, P<0.05). Similar results were found between KD-CAL(+) group and KD-CAL(-) group (all P<0.05). Level of IFN-γ associating H3K27me3 was increased, and mRNA level of IFN-γ and IFN-γ associating H3K4me3 was decreased after treatment than before treatment (all P<0.05). (3)Expression of T-bet protein and binding levels of Ash2L and Jmjd3 with IFN-γ gene were significantly higher in KD group than those in control group(all P<0.05), higher in KD-CAL(+) group than those in KD-CAL(-) group (all P<0.05). These parameters were significantly lower after treatment than before treatment (all P<0.05). Binding level of Ezh2 with IFN-γ gene was similar among various groups (all P>0.05). (4)In comparison with control or after treatment, surface receptors(IFN-γR1/2, IL-12Rβ1/2, IL-18Rα/β, TNFR1 and TLR4) and its downstream molecules(pSTAT1, pSTAT4, RIP(1) and MyD88) in CD4(+) T cells, and plasma concentrations of inflammatory cytokines(IFN-γ, IL-12, IL-18 and TNF-α) were found to be higher in KD group(all P<0.05). These parameters were also higher in KD-CAL(+) group than in KD-CAL(-) group (all P<0.05). Conclusion: Aberrant histone methylation of IFN-γ associating H3K4me3 and H3K27me3 caused by over-binding of Ash2L and Jmjd3 might be involved in immune dysfunction and vascular damage in KD in the acute phase.

Identification of differentially expressed microRNAs in acute Kawasaki disease

The present study used microarray analysis to screen the plasma expression of microRNAs (miRNAs) in patients with acute Kawasaki disease (KD) and aimed to explore the pathogenesis of KD. Plasma was collected from children with acute KD (n=6) and from healthy control children (n=6). Total RNA was extracted and differential miRNA expression between the two groups was determined. Differentially expressed miRNAs were validated using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in an independent cohort (n=8). Target genes of the differentially expressed miRNAs were predicted and analyzed for gene ontology term enrichment and Kyoto Encyclopedia of Genes and Genomes pathways. miRNA microarray analysis revealed that seven miRNAs (miRs) were significantly upregulated (hsa-let-7b-5p, hsa-miR-223-3p, hsa-miR-4485, hsa-miR-4644, hsa-miR-4800-5p, hsa-miR-6510-5p and hsa-miR-765) and three were significantly downregulated (hsa-miR-33b-3p, hsa-miR-4443 and hsa-miR-4515) in acute KD compared with the healthy controls. hsa-miR-223-3p expression levels detected by RT-qPCR were consistent with the microarray results. A total of 62 target genes of hsa-miR-223-3p were predicted. In total, 10 differentially expressed miRNAs were identified in acute KD, of which hsa-miR-223-3p was verified by RT-qPCR.

Sets of serum exosomal microRNAs as candidate diagnostic biomarkers for Kawasaki disease

Although Kawasaki disease is the main cause of acquired heart disease in children, no diagnostic biomarkers are available. We aimed to identify candidate biomarkers for diagnosing Kawasaki disease using serum exosomal microRNAs (miRNAs). Using frozen serum samples from a biobank, high-throughput microarray technologies, two-stage real-time quantitative PCR, and a self-referencing strategy for data normalization, we narrowed down the list of biomarker candidates to a set of 4 miRNAs. We further validated the diagnostic capabilities of the identified miRNAs (namely, CT(miR-1246)-CT(miR-4436b-5p) and CT(miR-197-3p)-CT(miR-671-5p)) in 79 samples from two hospitals. We found that this 4-miRNA set could distinguish KD patients from other febrile patients as well as from healthy individuals in a single pass, with a minimal rate of false positives and negatives. We thus propose, for the first time, that serum exosomal miRNAs represent candidate diagnostic biomarkers for Kawasaki disease. Additionally, we describe an effective strategy of screening for biomarkers of complex diseases even when little mechanistic knowledge is available.

Meta-analysis of risk factors associated with atherosclerosis in patients with Kawasaki disease

BACKGROUND

Kawasaki disease (KD) has now become the leading cause of acquired heart disease among children in developed countries. This study investigated whether patients with KD have an increased risk of atherosclerosis.

METHODS

Electronic databases, including PubMed, Embase and Springer link, were searched through June 1, 2015, for eligible studies. Studies were included when they met the following criteria: 1) an observational study focusing on evaluating the risk factors for atherosclerosis in patients with KD; 2) KD was diagnosed clinically according to the Japan Kawasaki Disease Research Committee or American Heart Association's diagnostic criteria; 3) the study subjects were KD patients without coronary heart disease or related cardiovascular disease (KD group) and non-KD patients as control (control group), and 4) investigation of important atherosclerosis risk factors, total cholesterol (TC), low-density lipoprotein cholesterol (LDL), triglycerides (TG), systolic blood pressure (SBP), and flowmediated dilatation (FMD). The methodological quality of the included studies was evaluated using the Newcastle- Ottawa Scale. Mean difference (MD) and relative risk (RR) and corresponding 95% confidence intervals (CI) were used to calculate the pooled results.

RESULTS

Sixteen studies were included with a total of 870 patients, including 421 KD patients and 449 non-KD controls. Differences in TG and SBP between KD patients and controls were not significant; in contrast, TC and LDL levels were significantly higher in KD patients than the controls, whereas FMD in the KD patients was significantly lower.

CONCLUSIONS

KD patients may have an increased risk of developing atherosclerosis.

Diagnostic accuracy of coronary angiography using 64-slice computed tomography in coronary artery disease

Objectives:

To conduct a meta-analysis and investigate the diagnostic value of 64-slice computed tomography (CT) angiography for diagnosing coronary artery disease (CAD) in patients.

Methods:

A comprehensive literature search from March 2005 to August 2014 was performed on the following databases: Cochrane Library; Medline; EmBase; PubMed; and BioMed Central database. As a reference standard, studies that assessed 64-slice CT angiography in detecting coronary artery stenosis (CAS) with invasive coronary angiography were included. Coronary artery stenosis was defined as ≥50% diameter stenosis. Diagnostic value was determined by pooling sensitivity, specificity, positive likelihood ratio (PLR) and negative likelihood ratio (NLR) values at segment-level analysis. Diagnostic accuracy was undertaken using area under the curve (AUC) value and summary receiver operating characteristic (SROC) curves. Publication bias was examined by Deek’s funnel plot asymmetry test.

Results:

Eight studies were included in the analysis, enrolling a total of 579 patients (7,407 segment coronary vessels). At segment-level, pooled sensitivity value was 90% (95% confidence interval [CI]: 83-95%), specificity was 91% (95% CI: 61-98%), PLR value was 9.7 (95% CI: 1.8-53.3), and NLR value was 0.11 (95% CI: 0.05-0.22) for CAS. Optimal cut-off point of sensitivity was 90%, and specificity under the SROC curve was 91%. The AUC value was 0.94.

Conclusion:

The 64-slice CT angiography is a reliable tool for detection of CAD when using a cut-off of ≥50% diameter stenosis in elderly population.

Long-term combined chemical and manure fertilizations increase soil organic carbon and total nitrogen in aggregate fractions at three typical cropland soils in China

Soil organic carbon (SOC), total nitrogen (TN), microbial biomass carbon (MBC) and nitrogen (MBN) are important factors of soil fertility. However, effects of the combined chemical fertilizer and organic manure or straw on these factors and their relationships are less addressed under long-term fertilizations. This study addressed changes in SOC, TN, MBC and MBN at 0-20 cm soil depth under three 17 years (September 1990-September 2007) long-term fertilization croplands along a heat and water gradient in China. Four soil physical fractions (coarse free and fine free particulate organic C, cfPOC and ffPOC; intra-microaggregate POC, iPOC; and mineral associated organic C, MOC) were examined under five fertilizations: unfertilized control, chemical nitrogen (N), phosphorus (P) and potassium (K) (NPK), NPK plus straw (NPKS, hereafter straw return), and NPK plus manure (NPKM and 1.5NPKM, hereafter manure). Compared with Control, manure significantly increased all tested parameters. SOC and TN in fractions distributed as MOC > iPOC > cfPOC > ffPOC with the highest increase in cfPOC (329.3%) and cfPTN (431.1%), and the lowest in MOC (40.8%) and MTN (45.4%) under manure. SOC significantly positively correlated with MBC, cfPOC, ffPOC, iPOC and MOC (R(2) = 0.51-0.84, P < 0.01), while TN with cfPTN, ffPTN, iPTN and MTN (R(2) = 0.45-0.79, P < 0.01), but not with MBN, respectively. Principal component analyses explained 86.9-91.2% variance of SOC, TN, MBC, MBN, SOC and TN in each fraction. Our results demonstrated that cfPOC was a sensitive SOC indicator and manure addition was the best fertilization for improving soil fertility while straw return should take into account climate factors in Chinese croplands.

The circulating level of endothelial progenitor cells after transcatheter closure of congenital heart disease in children

Data have shown that circulating endothelial progenitor cells (EPCs) closely correlate with the vascular endothelial layer state. The present study was designed to describe the evolution of EPCs in children before and 24 h after transcatheter closure surgery for occluding congenital heart disease. Three groups of patients were studied: the transcatheter closure of atrial septal defect (ASD) group (group 1), the transcatheter closure of patent ductus arteriosus (PDA) group (group 2), and the transcatheter closure of ventricular septal defect (VSD) group (group 3). The circulating EPC level was detected using flow cytometry measuring CD34 and kinase insert receptor double-positive mononuclear cells. The concentration of vascular endothelial growth factor (VEGF) was assessed by enzyme-linked immunosorbent assay. The fluoroscopy time was correctly recorded during the surgery. All of the data were collected before and 24 h after surgery. EPC level and VEGF concentration did not change significantly before and at 24 h after surgery in groups 1 and 2. In group 3, the level of circulating EPCs and VEGF concentration increased significantly 24 h after surgery. The fluoroscopy time in group 3 was significantly longer than in groups 1 and 2. The increased volume of EPCs and VEGF were positively correlated in group 3. Our results showed that transcatheter closure of PDA and ASD in children does not lead to increased circulating level of EPCs. Transcatheter closure of VSD may result in vascular endothelium injury as indicated by increased circulating EPC level.

[Effects of intravenous immunoglobulin and aspirin treatment on the functions of circulating endothelial progenitor cells in children with Kawasaki disease]

OBJECTIVE

To study the effects of intravenous immunoglobulin (IVIG) and aspirin treatment on the functions of circulating endothelial progenitor cells (EPCs) in children with Kawasaki disease (KD) and possible mechanisms.

METHODS

Blood samples were obtained in 10 children with KD before and 7 days after the treatment by IVIG and aspirin. MTT method, modified Boyden chamber method and cell culture plate adhesion method were used to assess the functions of EPCs, including proliferation, adhension and migration activities. The plasma levels of tumor necrosis factor-α (TNF-α) and high-sensitivity C reactive protein (hs-CRP) were also measured.

RESULTS

The functions of circulating EPCs 7 days after IVIG and aspirin treatment were significantly improved. IVIG and aspirin treatment significantly reduced plasma TNF-α and hs-CRP concentrations. There was a significant linear regression relationship between the reduced plasma TNF-α and hs-CRP levels and the increased functions of circulating EPCs.

CONCLUSIONS

IVIG and aspirin treatment can improve the functions of circulating EPCs, possibly through reducing plasma concentrations of TNF-α and hs-CRP.

[Decreased circulating endothelial progenitor cell function: relationship with serum concentrations of high-sensitivity C-reactive protein in children with Kawasaki disease]

OBJECTIVE

To study the function of circulating endothelial progenitor cells and its relationship with serum concentrations of high-sensitivity C-reactive protein (Hs-CRP) in children with Kawasaki disease.

METHODS

Ten children with Kawasaki disease and ten healthy children as a control group were enrolled. The peripheral mononuclear cells were induced into endothelial progenitor cells using Dulbecco's Modified Eagle Medium containing vascular endothelial growth factor and basic fibroblast growth factor. The proliferative ability, migratory ability and adhesive ability of endothelial progenitor cells were assessed by MTT methods, modified Boyden chamber methods and cell culture plate adhesion method, respectively. The concentrations of serum Hs-CRP were measured by latex enhanced turbidimetric immunoassay.

RESULTS

The proliferative ability, migratory ability and adhesive ability of endothelial progenitor cells in the Kawasaki disease group were significantly lower than those in the control group (P<0.01). The serum concentrations of Hs-CRP in the Kawasaki disease group were significantly higher than those in the control group (87.1+/-30.2 mg/L vs 5.3+/-3.4 mg/L; P<0.01). The function of circulating endothelial progenitor cells was negatively correlated with serum concentrations of Hs-CRP in the Kawasaki disease group.

CONCLUSIONS

The function of circulating endothelial progenitor cells is decreased in children with Kawasaki disease, which may be associated with the abnormal expression of inflammatory mediators.

The number and function of circulating endothelial progenitor cells in patients with Kawasaki disease

Kawasaki disease (KD) is associated with coronary artery injury. Studies have shown that the endothelial progenitor cell (EPC) participates in the process of arterial repair. Data have been reported that the number of EPC increased significantly in the subacute phase of KD. However, until now, there are no data about the functions of EPC in KD patients. The present study was designed to further investigate the number and functions of EPC in KD. Ten KD patients in the acute phase and ten healthy volunteers were recruited and attributed to the KD group and control group, respectively. The circulating CD34/kinase insert domain-containing receptor double positive cells were evaluated in the two groups using flow cytometry. In vitro assays were used to measure the functions of EPC, including proliferation, adhesion, and migration activities. The plasma levels of nitric oxide (NO), tumor necrosis factor-alpha (TNF-alpha), and high sensitivity C-reactive protein (hs-CRP) were also assessed in both groups. The number of EPC in the KD group was significantly higher than that of the control group (0.021 +/- 0.007% vs. 0.014 +/- 0.003%, P < 0.05). The migratory response of EPC was significantly decreased in the KD group, compared with that of the control group (5.50 +/- 1.78 vs. 3.40 +/- 1.35 cells/high power field, P < 0.01). Similarly, the proliferative and adhesive activities of EPC in the KD group were also decreased (0.47 +/- 0.08 vs. 0.66 +/- 0.07, P < 0.01; 6.5 +/- 2.12 vs. 11.2 +/- 2.04 cells/high power field, P < 0.01). The plasma NO, TNF-alpha, and hs-CRP levels in the KD group were higher than those of the control group (54.10 +/- 11.78 vs. 38.80 +/- 11.10 mumol/l, P < 0.01; 48.20 +/- 7.42 vs. 37.00 +/- 11.12 pg/ml, P < 0.05; 87.10 +/- 30.18 vs. 5.30 +/- 3.37 mg/l, P < 0.01). The number of circulating EPC positively correlated with the level of NO (r = 0.92, P < 0.001), and the functions of EPC negatively correlated with the levels of TNF-alpha and hs-CRP, respectively. In Kawasaki disease, the number of EPC was enhanced and the functions of EPC were attenuated. The two-way regulation of circulating EPC in KD patients may be associated with the disorders of cytokines or messengers in KD patients.

Berberine-induced upregulation of circulating endothelial progenitor cells is related to nitric oxide production in healthy subjects

OBJECTIVES

Berberine (BR) has a beneficial effect on endothelial function by increasing nitric oxide (NO), as NO plays a pivotal role in the regulation of endothelial progenitor cell (EPC) mobilization and function. The aim of the present study was to investigate whether BR-induced upregulation of circulating EPCs is related to NO production in healthy subjects.

METHODS

Twenty volunteers were recruited and received 400 mg of BR 3 times a day for 30 days. We assessed the number of EPC colony-forming units (EPC-CFUs), as well as the proliferative, adhesive and migratory activities of circulating EPCs before and after the 30-day BR therapy. The level of plasma NO was also measured before and after the 30-day BR therapy.

RESULTS

After 30 days of BR therapy, the number of EPC-CFUs was increased and the function of EPCs, including proliferation, adhesion and migration, was augmented. In parallel, BR therapy enhanced the plasma NO level. There was a significant linear regression relationship between the enhanced plasma NO level and the increased number and function of circulating EPCs.

CONCLUSIONS

BR-induced upregulation of the number and function of circulating EPCs in healthy subjects is related to NO production.

Increased circulating CD31+/CD42- microparticles are associated with impaired systemic artery elasticity in healthy subjects

BACKGROUND

Impaired artery elasticity has been found in various pathological conditions related to endothelial dysfunction. Recently, CD31+/CD42- microparticles (MPs) emerged as a marker of endothelial injury. Whether CD31+/CD42- MPs, generated under physiological conditions, are correlated with artery properties has not been reported.

METHODS

We evaluated brachia-ankle pulse-wave velocity (baPWV) (n = 76) and C1 large-artery and C2 small-artery elasticity indices (n = 56), using noninvasive devices for pulse-wave analysis in a group of healthy persons. The number of circulating CD31+/CD427- MPs (n = 76) was measured by flow cytometric analysis.

RESULTS

Circulating CD31+/CD42- MPs were positively correlated with values of baPWV (r = 0.371, P = .008) and with C1 large-artery and C2 small-artery elasticity indices (r = -0.294, P = .037; and r = -0.310, P = .027, respectively). Multivariate analysis identified CD31+/CD42- MPs as potent contributors to the development of impaired systemic artery elasticity.

CONCLUSIONS

The level of circulating CD31+/CD42- MPs, an important biomarker of dysfunctional endothelium and vascular injury, is closely associated with impaired systemic artery elasticity in healthy subjects. The present study suggests that CD31+/CD42- MPs may be a novel surrogate marker for the clinical evaluation of vascular damage.

[Fluid shear stress upregulated endothelial nitric oxide synthase gene expression and nitric oxide formation in human endothelial progenitor cells]

OBJECTIVE

To observe the effect of fluid shear stress on the eNOS gene expression and NO production in endothelial progenitor cells (EPCs).

METHODS

The peripheral blood mononuclear cells from healthy volunteers were inducted into EPCs and divided into stationary group (0 dyn/cm(2), 1 dyn/cm(2) = 0.1 Pa), low-flow shear stress group (5 dyn/cm(2)), medium-flow shear stress group (15 dyn/cm(2)) and high-flow shear stress group (25 dyn/cm(2)). The effects of shear stress on the endothelial nitric oxide synthase (eNOS) gene expression and nitric oxide (NO) production in human EPCs were measured.

RESULTS

Typical "spindle-shaped" appearance was shown in EPCs derived from peripheral blood mononuclear cells and were positively labeled by acetylated-LDL, lectin, FLK-1 and vWF. After 4 hours treatment with various shear stresses, the ratio of eNOS/beta-actin mRNA expression by human EPCs in low, medium and high-flow shear stress group was 0.364, 0.505 and 0.548 respectively, which was significantly higher than that in stationary group (0.183, all P < 0.05) and the NO secretion in human EPCs in low, medium and high-flow shear stress group was also significantly higher than that in stationary group (all P < 0.05).

CONCLUSION

Fluid shear stress enhances the eNOS mRNA expression and NO secretion in human EPCs, therefore, shear stress could potentiate the repair efficacy of EPCs for endothelial injury.

Shear stress contributes to t-PA mRNA expression in human endothelial progenitor cells and nonthrombogenic potential of small diameter artificial vessels

Seeding endothelial progenitor cells (EPCs) onto the surface of vascular grafts has been proved to be a promising strategy to improve nonthrombogenic potentials of small diameter artificial vessels. Here, we investigated whether in vitro shear stress modulates the tissue-type plasminogen activator (t-PA) secretion and mRNA expression in human EPCs and improves patency of the EPC-seeded polyurethane small diameter vascular grafts implanted in the canine carotid artery in vivo. In vitro shear stress, in a dose-dependent manner, increased t-PA secretion and mRNA expression of human EPCs. The in vivo implantation of EPC-seeded vascular grafts remained highly patent in shear stress pretreatment compared with stationary condition. The present findings demonstrate for the first time that in vitro shear stress can enhance t-PA secretion and gene expression in human EPCs, which contributes to improvement in nonthrombogenic potentials of EPC-seeded small diameter artificial vessels with maintenance of in vivo highly patency rate.

[Impaired endothelium-dependent vasodilation and arterial elasticity in patients with coronary artery disease]

OBJECTIVE

To investigate the change in endothelium-dependent vasodilation and arterial elasticity and the association between them in patients with coronary artery disease (CAD).

METHODS

Thirty patients with CAD and thirty control subjects were recruited for this study. Flow-mediated dilation (FMD) in the brachial artery was evaluated by ultrasound Doppler flow method. They also underwent a non-invasive assessment of C(1) large artery and C(2) small artery indices by using pulse wave analysis.

RESULTS

FMD was significantly reduced in CAD group compared with that in control group [(5.17 +/- 2.13)% vs (11.1 +/- 4.36)%, P < 0.05], C(1) large artery elasticity index was similar between the two groups [(11.59 +/- 4.56) ml/mm Hg x 10 vs (12.11 +/- 3.82) ml/mm Hg x 10, P > 0.05]. However, C(2) small artery elasticity index was significantly reduced in CAD group compared with that in control group [(4.20 +/- 1.80) ml/mm Hg x 100 vs (6.26 +/- 2.36) ml/mm Hg x 100, P < 0.05]. There was a positive association between reduced C(2) small artery elasticity index and impaired FMD (r = 0.53, P < 0.05).

CONCLUSIONS

There were impaired endothelium-dependent vasodilation and reduced C(2) small artery elasticity index in the patients with CAD, which were closely correlated with each other. The present study suggested that the measurement of C(2) small artery elasticity might be used as a novel index for the determination of endothelial function.

A Negative Element Located in the Upstream Flanking Region of the Gene Encoding Arginyl-tRNA Synthetase (argS) from Escherichia coli

The gene, argS, encoding the arginyl-tRNA synthetase (ArgRS) from Escherichia coli ( E.coli ) was overexpressed 1 000 fold in the transformant when E. coli TG1 was transformed with the recombinant plasmid containing argS and pUC18. In order to investigate the regulation of expression of E. coli argS, a series of deletion mutations was constructed. The results of SDS-PAGE showed that deletions of the whole 5' flanking region (argSdelta1) or the region in front of Shine-Dalgarno Sequence (argSdelta2) or the -10 region of promoter (argSdelta3), caused no overexpression of argS. If argS was deleted from 3' end of the flanking region (-189 nt) to the upstream of -10 region of promoter (argSdelta4), the -35 region (argSdelta5), -52 nt (argSdelta6), -70 nt (argSdelta7) and -122 nt (argSdelta8), respectively, the mutant gene was overexpressed to a level similar to that of argS bringing the full length 5' flanking region. However, in the expression of argSdelta4, argSdelta5, argSdelta6, some of ArgRS formed an inclusion body. By determination of RNA dot hybridization, the amount of mRNA produced in the transcription of argSdelta4, argSdelta5 and argSdelta6 was about 2--3 times than that of the wild type argS, argS delta7 and argS delta8. This indicated that the deletion of a 19 nt sequence (AATAGTGAAAACGGCAATA) located between -52 nt and -70 nt of the gene increased the transcription of argS. The 19 nt sequence is a negative region that represses transcription of argS. Deletion of the negative element may result in a faster production of ArgRS and the accumulation of some unfolding protein intermediates aggregating to form the inclusion body. The result by analysis of gel retardation shows that a factor binds to the negative element. Arginine induced specifically the transcription of argS and its effect correlated with the above negative element.

Three-dimensional localisation of fluorescence resonance energy transfer in living cells under two-photon excitation

Three-dimensional (3-D) imaging of fluorescence resonance energy transfer (FRET) in human cells under two-photon excitation was demonstrated in this study. A sample was prepared by expressing a donor and an acceptor in living cells and using an antibody to secure the proximity of contact between the donor and the acceptor. The quenching of fluorescence emission of a donor in the double-labelled cells indicates the presence of FRET that occurred in these living cells. Because of the quadratic relation of the excitation power, 3-D localisation of FRET becomes possible.

Effect of handling and fixation processes on fluorescence spectroscopy of mouse skeletal muscles under two-photon excitation

We investigated the effects of handling and fixation processes on the two-photon fluorescence spectroscopy of endogenous fluorophors in mouse skeletal muscle. The skeletal muscle was handled in one of two ways: either sectioned without storage or sectioned following storage in a freezer. The two-photon fluorescence spectra measured for different storage or fixation periods show a differential among those samples that were stored in water or were fixed either in formalin or methanol. The spectroscopic results indicate that formalin was the least disruptive fixative, having only a weak effect on the two-photon fluorescence spectroscopy of muscle tissue, whereas methanol had a significant influence on one of the autofluorescence peaks. The two handling processes yielded similar spectral information, indicating no different effects between them.

Near band-edge field-dependent absorption coefficient and refractive index determined by photocurrent and transmittance measurements

A technique is proposed for the extraction of precise values of field-dependent absorption coefficient alpha and refractive index n from photocurrent and transmittance measurements of optical modulator structures. The technique uses approximate results of alpha and n extracted from a simplified device as the initial input into an iterative procedure that utilizes the consistency between alpha and n to obtain successively better estimates of these parameters. The technique was applied to results that were measured experimentally, and we verified the accuracy by using synthetic data. Errors caused by measurement inaccuracy are also investigated. It is shown that the absorption coefficient has a modest sensitivity whereas the refractive index is insensitive to these errors.

[Study on auto-solidified tumor vaccine]

In order to evaluate the immune effect of Auto-solidified tumor vaccine induced by thermal doses of 65 degrees C for 5 minutes on the killing and inactivation of cancer cells in operation, a series of experimental and clinical studies were carried out, the results showed that Balb/c mice immunized with ASTV could tolerate the aggression of H22 3 x 10(8) cancer cells with efficiency of 93.3% (28/30), the inoperable advanced hepatic cancer proved in operation was hypothermited and ASTV was made for immune injection postoperatively, with the clinical efficiency 76.8% (53/69), and 5-year survival rate 23% (9/39), the difference with control group is significant. In recent years, it is recognized once again that tumor can induce specific immunity. The most important matter is how to stimulate the host to produce effective cellular immunity. Our results showed that the thermal biological effect could inactivate cancer cell and change nuclear antigen in host net-like immunity system. Under gene regulation, the host can obtain the cellular immune effect against cancer cells.

Studies on hyperthermic solidification as a supplement to surgical resection in the treatment of 39 advanced cases of liver cancer

Localized hyperthermic solidification therapy employs a high temperature of around 65 degrees C to induce biological heat effects for the solidification and inactivation of the cells of visceral cancers without affecting the physiological processes of the body or any of the viscera. This technique was used in combination with surgical resection to treat 39 moderately or far advanced cases of liver cancer and quite satisfactory results were obtained. The FHCL-92B localized hyperthermic solidification apparatus, designed and manufactured under the supervision of the authors, was preliminarily put into clinical use and exhibited its efficiency. It is believed that, if the technique of localized hyperthermic solidification is introduced more widely into the field of cancer surgery for internal organs, it will be of benefit to prevent iatrogenic metastases and to promote the efficacy of cancer surgery.