Drug Treatment Attenuates Retinal Ganglion Cell Death by Inhibiting Collapsin Response Mediator Protein 2 Phosphorylation in Mouse Models of Normal Tension Glaucoma

Normal tension glaucoma (NTG) is a progressive neurodegenerative disease in glaucoma families. Typical glaucoma develops because of increased intraocular pressure (IOP), whereas NTG develops despite normal IOP. As a subtype of open-angle glaucoma, NTG is characterized by retinal ganglion cell (RGC) degeneration, gradual loss of axons, and injury to the optic nerve. The relationship between glutamate excitotoxicity and oxidative stress has elicited great interest in NTG studies. We recently reported that suppressing collapsin response mediator protein 2 (CRMP2) phosphorylation in S522A CRMP2 mutant (CRMP2 KIKI) mice inhibited RGC death in NTG mouse models. This study evaluated the impact of the natural compounds huperzine A (HupA) and naringenin (NAR), which have therapeutic effects against glutamate excitotoxicity and oxidative stress, on inhibiting CMRP2 phosphorylation in mice intravitreally injected with N-methyl-D-aspartate (NMDA) and GLAST mutant mice. Results of the study demonstrated that HupA and NAR significantly reduced RGC degeneration and thinning of the inner retinal layer, and inhibited the elevated CRMP2 phosphorylation. These treatments protected against glutamate excitotoxicity and suppressed oxidative stress, which could provide insight into developing new effective therapeutic strategies for NTG.

Triglyceride to HDL-cholesterol ratio is a predictor of future coronary events: a possible role of high-risk coronary plaques detected by coronary CT angiography

Background

For the prevention of future cardiovascular events, control of residual risks such as triglyceride rich lipoproteins and HDL-cholesterol is an emerging problem beyond LDL-cholesterol. Triglyceride to HDL-cholesterol ratio (TG/HDL ratio) has been reported to be useful for risk classification of cardiovascular diseases. Meanwhile, several studies showed that high-risk plaque characteristics evaluated with coronary CT angiography (cCTA) was associated with the incidence of acute coronary syndrome. However, the relationship of TG/HDL ratio with coronary plaque characteristics and its impact of this association on future coronary events have not been fully elucidated.

Purpose

The aim of this study was to evaluate the association between TG/HDL ratio and high-risk plaque detected by cCTA and its impact on future coronary events.

Methods

A total of 944 patients suspected stable coronary artery disease who underwent cCTA at our institution were analyzed (mean 64-year-old, 55% male). Patients were divided into two groups by the median value of TG/HDL ratio (higher TG/HDL: TG/HDL ratio ≥2.0, lower TG/HDL: TG/HDL ratio <2.0). Coronary high-risk plaques were defined as a plaque with all three components; low attenuation plaque (<50H.U.), positive remodeling (remodeling index >1.1) and spotty calcification. Cardiovascular event was defined as cardiovascular death, acute coronary syndrome, and late coronary revascularization after 30 days of CT acquisition.

Results

The higher TG/HDL ratio was significantly associated with male gender (63% vs. 48%, P<0.001), body mass index (24.8±3.8 vs. 22.9±4.0, p<0.001), the prevalence of hypertension (65% vs. 54%, P<0.001), dyslipidemia (60% vs. 42%, P<0.001), diabetes mellitus (38% vs. 27%, P=0.001) and current smoking (26% vs. 10%, p<0.001). Regarding cCTA findings, the prevalence of significant stenosis, calcified plaque, non-calcified plaque, coronary plaques with low attenuation plaque, positive remodeling and spotty calcification in the higher TG/HDL group were greater than those in the lower group (Figure 1A). Of note, the difference in high-risk plaque between two groups was significant. (18% vs. 11%, p=0.004). Multivariate logistic analysis revealed that the TG/HDL ratio was an independent risk factor for high-risk plaque even after adjustment (OR, 1.35; 95% CI, 1.01–1.81; p=0.049). Regarding coronary events (median follow-up duration; 48 months), Kaplan-Meier curve showed poor event-free rate in the higher TG/HDL group (Figure 1B). At Cox proportional hazard analysis, higher TG/HDL ratio (HR, 1.94; 95% CI, 1.01–3.70; p=0.046) and CT-verified high-risk plaque (HR, 2.36; 95% CI, 1.27–4.38; p=0.006) were independent predictive factors for coronary events even after adjustment.

Conclusion

TG/HDL ratio is involved in the vulnerability of CT-verified coronary plaque characteristics. This association may play an important role in the prognostic impact of TG/HDL ratio on future cardiovascular events.

Funding Acknowledgement

Type of funding source: None

Determination of contrast medium dose for hepatic CT enhancement with improved body size dependency using a non-linear analysis based on pharmacokinetic principles

AIM

To propose a pharmacokinetic non-linear analysis method to determine contrast medium (CM) dose for computed tomography (CT) hepatic enhancement to improve body size dependency and validate the proposed CM dose determination method through a clinical study.

MATERIALS AND METHODS

Enhancement data of 105 patients who underwent hepatic dynamic CT with a fixed CM dose were analysed. From the analysis results, CM doses as a function of each of four body size indices (body weight [BW], lean body weight [LBW], blood volume [BV], and body surface area [BSA]) for achieving improved body size dependency were determined (proposed method), and the body size dependencies were simulated using the enhancement data from 105 patients. The proposed method was validated with a two-arm clinical study on BW. Body size dependency was evaluated using p-value of correlation coefficient between Body size indices and enhancements (p<0.05: significant dependency) and mean absolute error (MAE).

RESULTS

The simulation showed that significant body size dependencies not considered by the conventional method can be improved by the proposed method. MAEs of BW, LBW, and BV were also significantly reduced (p<0.05). The clinical study with BW demonstrated a similar improvement to that in the simulation result. MAE was also significantly reduced (p<0.001).

CONCLUSION

The proposed method demonstrated more improved BW, LBW, and BV dependence compared to the conventional method. Through the two-arm clinical study, the proposed method using BW only, without height information, is a suitable index for improving body size dependency.

P3632Prognostic impact of aortic valve stenosis in patients with acute myocardial infarction

Background

Aortic valve stenosis (AS) is associated with the presence and severity of coronary artery disease independently of clinical risk factors, which leads to increased cardiovascular mortality. However, the prevalence of AS and its prognostic value among patients with acute myocardial infarction (AMI) remain unknown.

Purpose

The purpose of this study was to investigate the prevalence and prognostic impact of AS in AMI patients.

Methods

We studied 2,803 AMI patients using data from Mie ACS registry, a prospective and multicenter registry. Patients were divided into subgroups according to the presence and severity of AS based on maximal aortic flow rate by Doppler echocardiography before hospital discharge: non-AS <2.0 m/s, 2.0 m/s≤mild AS <3.0 m/s, 3.0 m/s≤moderate AS <4.0m/s and severe AS≥4.0 m/s. The primary outcome was defined as 2-year all-cause mortality.

Results

AS was detected in 79 patients (2.8%) including 49 mild AS, 23 moderate AS and 6 severe AS. AS patients were significantly older (79.9±9.8 versus 68.3±12.6 years), and higher killip classification than non-AS patients (P<0.01, respectively). However, left ventricular ejection fraction, and prevalence of primary PCI was similar between the 2 groups. During the follow-up periods (median 725 days), 333 (11.9%) patients experienced all-cause death. AS patients demonstrated the higher all-cause mortality rate compared to that of non-AS patients during follow up (47.3% versus 11.3%, P<0.0001, chi square). Kaplan-Meier curves showed that the probability of all-cause mortality was significantly higher among AS patients than non-AS patients, and was highest among moderate and severe AS (See figure A and B). Cox regression analyses for all-cause mortality demonstrated that the severity of AS was the strongest and independent poor prognostic factor (HR 1.71, 95% CI 1.30–2.24, P<0.001, See table).

Cox hazard regression analysis Hazard ratio 95% Confidential interval P-value Severity of aortic valve stenosis 1.71 1.30–2.24 <0.001 Killip classification 1.63 1.46–1.82 <0.001 Age 1.07 1.06–1.09 <0.001 Serum creatinine level 1.05 1.03–1.08 <0.001 Max CPK level 1.00 1.00–1.01 <0.001 Left ventricular ejection fraction 0.96 0.95–0.97 <0.001 Primary percutaneous coronary intervention 0.67 0.47–0.96 0.03 CPK suggests creatinine phosphokinase.

All cause mortality

Conclusions

The presence of AS of any severity contributes to worsening of patients' prognosis following AMI independently of other known risk factors.

Acknowledgement/Funding

None

P1956Geriatric nutritional risk index as predictor for long-term survival and cardiovascular or limb events in peripheral arterial disease patients

Background

The geriatric nutritional risk index (GNRI) is a simple tool to assess the nutritional risk and associated with mortality. However, there are no reports focusing GNRI in peripheral artery disease (PAD) patients.

Purpose

The purpose of this study was to examine the effects of GNRI for long-term survival, cardiovascular and limb events in PAD patients.

Methods

A prospective cohort study was performed in 1219 PAD patients. Baseline GNRI was calculated from serum albumin level and body-mass-index. The patients were divided into four groups by GNRI level (G1: >98; G2: 92–98; G3: 82–91; G4: <82). The endpoints were overall survival (OS) and freedom from major adverse cardiovascular and limb events (MACE and MACLE).

Results

The median follow-up was 73 months. There were 626 deaths (51.4%) during follow-up. The rate of cardiovascular death among dead was 51.3%. The OS rates markedly depended on GNRI level (p<0.01). The 5-year OS rates were G1: 80.8%, G2: 62.0%, G3: 40.0%, G4: 23.3%, respectively. In multivariate analyses, GNRI, age, low ankle brachial pressure index (ABI), low estimated glomerular filtration rate (eGFR), and high C-reactive protein (CRP) levels were independent factors associated with OS (<0.05). GNRI, age, low ABI, diabetes mellitus, coronary artery disease, lower eGFR and higher CRP levels were associated with MACE and MACLE (p<0.05, respectively). Besides, statins improved OS, MACE, and MACLE (<0.01, respectively).

Conclusions

GNRI was an independent predictor for OS, MACE, and MACLE in PAD patients. Furthermore,statins improved OS, MACE and MACLE in patients with PAD.

P692Chemoradiation therapy to patients with lung cancer exacerbates thoracic aortic calcification

Introduction

Development of chemoradiation therapy (CRT) has improved mortality in patients with cancer. Whereas, it is emerging problem that cancer-survivors suffer from cardiovascular diseases, and the association between modern CRT and the increase in future cardiovascular events is suggested. Meanwhile, previous studies showed that thoracic aortic calcification (TAC) detected by computed tomography (CT), a marker of atherosclerosis, was associated with all-cause mortality and cardiovascular events. However, the influence of CRT on TAC progression remains unclear.

Purpose

The purpose of this study was to evaluate whether CRT would exacerbate TAC.

Methods

A total of 68 patients who treated lung cancer at our hospital between 2011 and 2015 were retrospectively analyzed (mean 62 year-old, male 78%): 35 patients underwent surgical treatment after induction CRT (CRT group) and 33 patients underwent surgical treatment alone (control group), extracted by propensity score matching by age, sex, smoking status, and diseased side. The volume of TAC between 2nd and 12th thoracic vertebrae was quantitatively measured with CT imaging, at baseline and at 1 year follow-up. The annual percent change in TAC was compared between the CRT and the control group. Moreover, the independent relationship between implementation of CRT and the progression of TAC was assessed by multivariate logistic regression analysis, adjusting for age, gender, conventional atherosclerotic risk factors and baseline aortic calcification volume.

Results

Patients in the CRT group received radiation (mean 47.3±4.0 Gy) and chemotherapy: 2 courses of cisplatin with docetaxel (34 cases) or vinorelbine (1 case). The prevalence of dyslipidemia, taking statins and diabetes drugs were significantly higher in the control groups (17% vs. 39%; p=0.041, 11% vs. 33%; p=0.029, 3% vs. 18%; p=0.044, respectively). Baseline C-reactive protein level was significantly higher in the CRT group (0.255 vs. 0.115; p=0.034). In univariate analysis, the annual percent change in TAC volume was significantly increased in the CRT group compared with the control group (37.6% vs. 23.3%; p=0.006). Multivariate logistic regression analysis demonstrated that CRT was an independent factor associated with the progression of TAC volume, even after adjustment for baseline calcification volume and coronary risk factors (OR, 3.90; 95% CI, 1.32–11.47; p=0.014).

Conclusion

CRT to patients with lung cancer exacerbates thoracic aortic calcification, which may result in future cardiovascular events.

Plasma Collection Using Nafamostat Mesilate and Dipyridamole as an Anticoagulant

Nafamostat mesilate (FUT-175) is a strong protease inhibitor and is used as an anticoagulant in extracorporeal circulation. In the present study, we administered FUT and dipyridamole as anticoagulants during donor plasmapheresis, and the additional effect of dipyridamole was examined. In dogs weighing about 15 Kg, donor plasmapheresis was performed using a cellulose triacetate membrane plasmaseparator (PEX-15, Nipro), and 300 ml of filtrated plasma was obtained within 30 minutes. These dogs were divided into two groups, 50 mg/h of FUT alone was infused (group A, n=10), and the same dose of FUT and 25 mg/h of dipyridamole were infused (group B, n=5) during plasmapheresis. Changes of the coagulation system, blood cell counts and complement system were investigated. In clinical cases, an artificial liver support therapy using FUT as an anticoagulant was performed on 8 patients with acute liver failure, and blood compatibility was examined.

In dogs, RBC counts and hematocrits were almost stable, but WBC counts were decreased to about 70% of the previous value. Platelets counts were about 60% and 80% of the previous value, in group A and group B, respectively, at the end of the plasmapheresis (P<0.01). Clotting factor VIII was diminished to about 20% and 35% of the previous value in group A and B, respectively. In clinical cases, all patients received the plasma exchange combined with hemodialysis using FUT as an anticoagulant, and no distinct side effect was observed during plasma exchange.

Spectroscopy of Pionic Atoms in ^{122}Sn(d,^{3}He) Reaction and Angular Dependence of the Formation Cross Sections

We observed the atomic 1s and 2p states of π^{-} bound to ^{121}Sn nuclei as distinct peak structures in the missing mass spectra of the ^{122}Sn(d,^{3}He) nuclear reaction. A very intense deuteron beam and a spectrometer with a large angular acceptance let us achieve a potential of discovery, which includes the capability of determining the angle-dependent cross sections with high statistics. The 2p state in a Sn nucleus was observed for the first time. The binding energies and widths of the pionic states are determined and found to be consistent with previous experimental results of other Sn isotopes. The spectrum is measured at finite reaction angles for the first time. The formation cross sections at the reaction angles between 0° and 2° are determined. The observed reaction-angle dependence of each state is reproduced by theoretical calculations. However, the quantitative comparison with our high-precision data reveals a significant discrepancy between the measured and calculated formation cross sections of the pionic 1s state.

A Framework Supporting the Development of a Grid Portal for Analysis Based on ROI

Objectives: In our research on brain function analysis, users require two different simultaneous types of processing: interactive processing to a specific part of data and high-performance batch processing to an entire dataset. The difference between these two types of processing is in whether or not the analysis is for data in the region of interest (ROI). In this study, we propose a Grid portal that has a mechanism to freely assign computing resources to the users on a Grid environment according to the users’ two different types of processing requirements.

Methods: We constructed a Grid portal which integrates interactive processing and batch processing by the following two mechanisms. First, a job steering mechanism controls job execution based on user-tagged priority among organizations with heterogeneous computing resources. Interactive jobs are processed in preference to batch jobs by this mechanism. Second, a priority-based result delivery mechanism that administrates a rank of data significance.

Results: The portal ensures a turn-around time of interactive processing by the priority-based job controlling mechanism, and provides the users with quality of services (QoS) for interactive processing. The users can access the analysis results of interactive jobs in preference to the analysis results of batch jobs. The Grid portal has also achieved high-performance computation of MEG analysis with batch processing on the Grid environment.

Conclusion: The priority-based job controlling mechanism has been realized to freely assign computing resources to the users’ requirements. Furthermore the achievement of high-performance computation contributes greatly to the overall progress of brain science. The portal has thus made it possible for the users to flexibly include the large computational power in what they want to analyze.

Anti-β2-glycoprotein I antibodies

The relationship between presence of anti-β2-glycoprotein I autoantibodies (aβ2-GPI) and history of thrombosis is now widely known. However, differences in the methodology of aβ2-GPI detection have made the comparison of data from different laboratories extremely difficult. We discuss the significance of aβ2-GPI of the IgG, IgM and IgA isotypes, and our approach to developing an easier and more reproducible method for the detection of this autoantibody. In addition, we present data that shows that commercially available enzyme immunoassay plates differ regarding detectability of aβ2-GPI. Since the clinical significance of this heterogeneity is presently unclear, the set-up of the detection systems and interpretation of data need great care.

Human monoclonal antibodies against the complex of phosphatidylserine and prothrombin from patients with the antiphospholipid antibodies

The presence of antibodies against the complex of prothrombin and phosphatidylserine (aPS/PT) more significantly correlates with manifestations of antiphospholipid syndrome (APS) and with the presence of lupus anticoagulants (LA) than antibodies against prothrombin bound to oxygenated polystyrene (aPT-A). To investigate immunological specificities and functional activities of aPS/PT, four monoclonal aPS/PT, designated as HG-4, KE-6, KF-5 and KF-6, from two patients with antiphospholipid antibodies (aPL) were established and characterized. Three of these antibodies (HG-4, KF-5 and KF-6) recognized the complex of phosphatidylserine and prothrombin, but did not react to prothrombin directly coated on oxygenated plates. KE-6 bound not only to the complex of phosphatidylserine and prothrombin but also to prothrombin on oxygenated plates. None of them showed the binding activity to prothrombin directly coated on non-oxygenated plates. HG-4, KE-6 and KF-5 had LA-like activity. The findings support the hypothesis that autoimmune aPS/PT recognize the cryptic epitopes or neoepitopes exposed upon interaction between prothrombin and phosphatidylserine, and that aPS/PT are, at least in part, responsible for LA activity. Lupus (2007) 16, 509—516.

MR Imaging of Hippocampal Sulcus Remnant: Age-Related Differences

The hippocampal sulcus remnant (HSR) is often observed at the medial temporal lobe on MR images. In the present study, we made a retrospective assessment of the frequency and age-related differences in HSR in routine brain MR examinations of 1000 patients, 494 females and 506 males. Cases with one or several spots that were hypointense on T1-weighted and FLAIR images and hyperintense on T2-weighted images were defined as positive for HSR. Abnormal spots with the same intensity as cerebrospinal fluid were observed in 210 out of 506 males and in 193 out of 494 females. No significant sex-related differences were observed in the frequency of HSR. The HSR was seen more frequently with age in both males and females. Patients with hypertension had a significantly higher frequency of HSR.

[Diffusion studies of redox-sensitive nitroxyl spin probes through bilayer lipid membranes using 300 MHz electron spin resonance spectrometer]

Electron spin resonance (ESR) studies were carried out for 14N-labeled deuterated 3-methoxy-carbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (MC-PROXYL) and 3-carboxy-2,2,5,5-tetramethyl-1-pyrrolidin-1-oxyl (carboxy-PROXYL) in pure water and various concentrations of liposomal solutions by using 300 MHz ESR spectrometer. The ESR parameters such as the line width, hyperfine coupling constant, rotational correlation time, g-factor, partition parameter and permeability were reported for the samples. The line width broadening was observed for MC-PROXYL and carboxy-PROXYL in liposomal solution. The hyperfine coupling constant was observed for both nitroxyl spin probes. The permeable and impermeable nature of nitroxyl spin probes was demonstrated. The rotational correlation time increases with increasing concentration of liposome. The partition parameter increases with increasing concentration of liposome for MC-PROXYL, which indicates that the nitroxyl spin probes diffuse into lipid membrane. The permeability value decreases with increasing concentration of liposome, which reveals an increase in membrane permeability. The peaks corresponding to the lipid phase were observed for MC-PROXYL in liposomal solution, but not resolved for carboxy-PROXYL. These results confirm the permeable and impermeable nature of nitroxyl spin probes.

Blood pressure control in a Japanese population with chronic kidney disease: a baseline survey of a nationwide cohort

BACKGROUND

Hypertension is a key risk factor for adverse renal outcomes in chronic kidney disease (CKD), and strict blood pressure control is recommended to halt its progression. This study assessed blood pressure control in the Japanese CKD population.

METHODS

We used a nationwide database of 250,130 subjects (aged 20-88), including 45,845 CKD subjects (18.3%), participated in an annual health check, "The Specific Health Check and Guidance in Japan," and examined the relationship between CKD status and blood pressure. Blood pressures were measured in sitting position by trained staff, and target blood pressure for CKD subjects was defined as systolic (SBP)/diastolic blood pressure (DBP) <130/80 mm Hg.

RESULTS

In total population, CKD subjects had a higher prevalence of hypertension (58.0% vs. 41.8%, P < 0.001) and a higher proportion with antihypertensive medication (42.4% vs. 26.7%, P < 0.001), compared with non-CKD subjects. The proportion of subjects achieving target blood pressure was significantly lower among total CKD subjects than among total non-CKD subjects (34.6% vs. 43.8%, P ≤ 0.001). Among CKD subjects, these proportions were especially low in those with stage 4-5 (24.3-27.5%), those on antihypertensive medication (21.6%) and those with proteinuria ≥2± (21.3%). Logistic regression analysis showed that independent factors for high-blood pressure in CKD subjects were age, male gender, alcohol consumption, nonsmoking, diabetes, dyslipidemia, obesity, proteinuria, and antihypertensive medication.

CONCLUSIONS

Blood pressure control was inadequate in the majority of Japanese CKD subjects, despite antihypertensive treatment. More aggressive efforts to achieve target blood pressures among CKD subjects are recommended.

Positron annihilation in hydrogen-doped alkali-metal fullerides

Hydrogen-doped alkali-metal fullerides were studied by means of mass-analyzed thermal desorption and positron annihilation. The hydrogen desorption spectra reveal the inclusion of hydrogen in the fullerides as two types of components; one weakly adsorbed and the other strongly bound, probably as hydride ion. The positron lifetime spectra demonstrate that hydrogen-doping to alkali-metal fullerides increases a concentration of higher-order vacancy-type defects, through which more than 50% injected positrons decay with a lifetime of 0.42–0.71 ns.

Anti-tumor necrosis factor therapy in patients with difficult-to-treat lupus nephritis: a prospective series of nine patients

OBJECTIVE

To clarify the efficacy and safety of anti-TNF-alpha therapy for intractable lupus nephritis.

METHODS

In nine patients with systemic erythematosus who presented with lupus nephritis resistant to steroids and immunosuppressants, 200 mg/body of infliximab was drip-infused three times. No changes were made to other treatments for three months after the start of anti-TNF-alpha therapy, and urinary findings, renal function, serum complement, anti-DNA antibody, SLE activity, and adverse events were examined for six months after the start of anti-TNF-alpha therapy.

RESULTS

One of the nine patients developed pyelonephritis after the first infliximab injection and received no further injections. The remaining eight patients received 3 infliximab injections. Of the eight patients, urinary protein decreased after anti-TNF-alpha therapy in six patients, and the SLEDAI improved in five patients. Urinary findings and/or SLE activity improved in six patients. Of the patients whose urinary protein levels decreased after anti-TNF-alpha therapy, proteinuria recurred six months after anti-TNF-alpha therapy in one patient. After anti-TNF-alpha therapy, proteinuria and the SLEDAI improved significantly. With respect to adverse events, therapy was discontinued in one patient who developed pyelonephritis, and one patient developed decreased blood pressure due to infusion reactions. In one patient in whom the steroid dosage was increased due to poor response to anti-TNF-alpha therapy, brainstem infarction occurred four months later. In one patient, anti-DNA antibody levels increased after therapy, but none of the patients had decreased serum complement levels or increased SLE activity.

CONCLUSION

In intractable lupus nephritis, anti-TNF-alpha therapy improved urinary protein levels and SLE activity. Although adverse events must be monitored cautiously, it may be possible to use anti-TNF-alpha therapy as a third-line treatment.

Expression profiling of genes related to asthma exacerbations

BACKGROUND

Asthma is a chronic airway inflammatory disease; however, the molecular mechanisms that underlie asthma exacerbation are only partially understood.

OBJECTIVE

To identify gene expression signatures that reflect the acute exacerbation of asthma, we examined the differential expression of genes during asthma exacerbation and stable condition by using microarray analysis.

METHODS

The subjects were mite-sensitive asthmatic children and non-asthmatic control children. The children were divided into four groups (AE: asthma exacerbation, n=12; SA: stable asthma, n=11; IC: infected control, n=6; and NC: non-infected control, n=5). Total RNA was extracted from peripheral blood mononuclear cells and subjected to microarray analysis with Illumina Human Ref8 BeadChip arrays. Welch's t-test was performed to identify genes whose expression was altered during asthma exacerbation. Quantitative real-time RT-PCR was performed on samples collected from 43 asthmatic children and 11 control children to verify the microarray results.

RESULTS

The expression of 137/16 genes was significantly up/down-regulated during asthma exacerbation assessed by microarray analysis. Of the genes, 62 were also differentially expressed during upper respiratory infection. Many of the asthma exacerbation related genes were involved in defence responses and responses to external stimuli, but these associations disappeared after excluding the infection-related genes. Quantitative real-time RT-PCR confirmed that the genes related (S100A8 and GAS6) and unrelated to infections (CD200 and RBP7) were differentially expressed during asthma exacerbation (P<0.01).

CONCLUSIONS

Previously unidentified immune responses during asthma exacerbation may provide further clarification of the molecular mechanisms underlying asthma.