Prognostic impact of plasma level of NT-pro BNP in patients with microvascular angina – a report from the international cohort study by COVADIS

Aims

Although the importance of microvascular angina (MVA) has been emerging, prognostic biomarkers for MVA remain to be developed. We thus aimed to examine whether plasma level of N-terminal prohormone of brain natriuretic peptide (NT-pro BNP) could predict the prognosis of MVA patients.

Methods

In the international prospective cohort study of MVA patients by the Coronary Vasomotor Disorders International Study (COVADIS) group, we evaluated the association between plasma level of NT-pro BNP and the incidence of major adverse cardiovascular events (MACE), including cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, and hospitalization due to heart failure or unstable angina.

Results

We examined a total of 226 MVA patients (M/F 66/160, 61.9±10.2 [SD] years) with both plasma NT-pro BNP levels and echocardiographic data in the COVADIS study. Plasma NT-pro BNP level was elevated (median 94 pg/ml, IQR 45–190) while mean LVEF (69.2±10.9%) and E/e' (10.7±5.2) were almost normal. During follow-up period of a median of 365 days (IQR 365–482), 29 MACEs occurred. ROC curve analysis identified plasma NT-pro BNP level of 78 pg/ml as the optimal cut-off value. Multivariable logistic regression analysis revealed that plasma NT-pro BNP level ≥78 pg/ml significantly correlated with the incidence of MACE (odds ratio (OR) [95% confidence interval (CI)] 3.11 [1.14–8.49], P=0.03). When divided into 2 groups by NT-pro BNP 78 pg/ml, the Kaplan-Meier survival analysis showed a significantly worse prognosis in the group with NT-pro BNP ≥78 (log lank, P=0.03) (Figure).

Conclusions

These results indicate that plasma NT-pro BNP level is a novel prognostic biomarker for MVA patients.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Japan Heart Foundation

Plasma MMP-9 Levels as the Future Risk of Conversion to Dementia in ApoE4-Positive MCI Patients: Investigation Based on the Alzheimer's Disease Neuroimaging Initiative Database

BACKGROUND

Matrix metalloproteinase 9 (MMP-9) has been reported to be correlated with declines in hippocampal volume and cognitive function in ApoE4-positive MCI patients.

OBJECTIVES

The present study was aimed to investigate the effects of plasma matrix MMP-9 on the conversion risk between mild cognitive impairment (MCI) patients with and without ApoE4.

DESIGN AND SETTING

Retrospective observational study using the data extracted from the Alzheimer's Disease Neuroimaging Initiative database.

PARTICIPANTS

We included 211 ApoE4-positive MCI subjects (ApoE4+ MCI) and 184 ApoE4-negative MCI subjects (ApoE4- MCI).

MEASUREMENTS

We obtained demographic and data including plasma MMP-9 levels at baseline and longitudinal changes in Clinical Dementia Rating (CDR) up to 15 years. We compared conversion rates between ApoE4+ MCI and ApoE4- MCI by the Log-rank test and calculated the hazard ratio (HR) for covariates including age, sex, educational attainment, drinking and smoking histories, medications, and plasma MMP-9 levels using a multiple Cox regression analysis of ApoE4+ MCI and ApoE4- MCI.

RESULTS

No significant differences were observed in baseline plasma MMP-9 levels between ApoE4+ MCI and ApoE4- MCI. High plasma MMP-9 levels increased the conversion risk significantly more than low plasma MMP-9 levels (HR, 2.46 [95% CI, 1.31-4.48]) and middle plasma MMP-9 levels (HR, 1.67 [95% CI, 1.04-2.65]) in ApoE4+ MCI, but not in ApoE4- MCI.

CONCLUSION

Plasma MMP-9 would be the risk of the future conversion to dementia in ApoE4+ MCI.

Clinical implications of coronary artery morphology of patients with ischemia and non-obstructive coronary artery disease (INOCA) -An intracoronary OCT study-

Introduction

Ischemia and non-obstructive coronary artery disease (INOCA), including microvascular spasm (MVS) and epicardial spasm, has recently attracted much attention, for which in vivo imaging evaluation for coronary artery morphology is warranted for better understanding of this disorder. Besides the improved diagnostic accuracy of optical coherence tomography (OCT) for coronary plaques, we have recently demonstrated its capability for in vivo visualization of coronary adventitial vasa vasorum (VV) and the enhanced VV formation in patients with epicardial spasm.

Purpose

We aimed to examine OCT-delineated morphological characteristics in patients with INOCA in vivo.

Methods

A total of 335 consecutive INOCA patients, who underwent pharmacological spasm provocation tests, lactate sampling, and OCT imaging over the entire length of the left anterior descending (LAD) coronary arteries, were enrolled at our institute over 68 months from April 2013. They were classified into 4 groups; control with non-cardiac chest pain, MVS, diffuse spasm (DS), or focal spasm (FS) (Fig. 1A). MVS was diagnosed when negative lactate extraction ratio (coronary orifice < coronary sinus) was detected despite the absence of epicardial spasm during the spasm provocation test. DS was defined as epicardial spasm induced in more than 2 coronary segments in LAD, and FS as epicardial spasm in one segment. Quantitative analyses for adventitial inflammation and atherosclerotic changes were performed by calculating VV density and %area stenosis (AS) on OCT (Fig. 1B, E). Furthermore, index of microcirculatory resistance (IMR), a marker of microvascular disorder with a cut-off value of ≥25, was measured during intravenous infusion of adenosine, which was then correlated with VV densities in the MVS and DS groups. Coronary plaque with a necrotic core was classified as fibroatheroma (FA), and the number of OCT frames with internal VV (IVV) in the atheroma was counted.

Results

VV density was significantly higher in MVS as compared with the controls (Fig. 1B). DS was most prevalent in INOCA (Fig. 1A) with highest VV density (Fig. 1B). Patients with IMR≥25 were predominantly distributed with a gradual increase in the MVS, DS, and FS groups, but none in the controls (Fig. 1C). Importantly, there was a significant positive correlation between VV densities and IMR in the MVS and DS groups (Fig. 1D). In addition, FS had the largest plaque size and showed the highest prevalence of FA and IVV (Fig. 1E–G).

Conclusions

These results indicate that MVS and DS are characterized by vasomotion abnormalities associated with adventitial inflammation and microvascular disorder, while FS by vulnerable atherosclerotic phenotype, suggesting that OCT may be useful for screening high-risk populations in INOCA.

Figure 1

Funding Acknowledgement

Type of funding source: None

P3575Clinical importance of fractional flow reserve in patients with organic coronary stenosis and vasospastic angina

Background

Vasospastic angina (VSA), which is one of the important functional cardiac disorders, may also play a role in the pathogenesis of atherosclerosis. Conversely, organic coronary stenosis is also known as an independent predictor for poor clinical outcomes in VSA patients. Although VSA patients have a variable degree of organic coronary stenosis in clinical setting, the functional importance of organic stenosis in those patients remains to be elucidated.

Purpose

The aim of this study was to examine the clinical importance and prognostic impact of fractional flow reserve (FFR) in patients with VSA and organic coronary stenosis.

Methods

We enrolled 236 consecutive patients with suspected vasospastic angina who underwent acetylcholine provocation test for coronary spasm (M/F 148/88, 63.6±12.0 [SD] yrs.). Among them, 175 patients (74.1%) were diagnosed as having VSA, while the remaining non-VSA patients were regarded as controls (Group-C, n=61). We divided the VSA patients into 3 groups based on angiographical findings and FFR values; VSA with no organic stenosis (>50% luminal stenosis) (Group-N, n=110), organic stenosis and high FFR (≥0.80) (Group-H, FFR 0.87±0.05, n=36), and organic stenosis and low FFR (<0.80) (Group-L, FFR 0.71±0.07, n=29). We evaluated the incidence of major adverse cardiovascular events (MACE), including cardiovascular death (CVD), non-fatal myocardial infarction (MI), urgent percutaneous coronary intervention (PCI), and hospitalization due to unstable angina pectoris (UAP) during the median follow-up period of 656 days.

Results

The groups with organic stenosis (Groups H and L) were characterized by higher prevalence of diabetes mellitus (Group-C/N/H/L, 23.0/20.9/44.4/34.5%, P=0.03) and dyslipidemia (Group-C/N/H/L, 37.7/39.1/50.0/65.5%, P=0.03) as compared with Group-C. After provocation test, all VSA patients received calcium channel blockers (CCBs). In addition, 20 days (median) after provocation test, 26 patients (92.9%) in Group-L underwent elective PCI with coronary stents, while no patient underwent PCI in Groups N or H. The incidence of MACE during follow-up was significantly higher in Group-L (Group-C/N/H/L; 1.6/3.6/5.6/27.6%, log-rank P<0.001), whereas clinical outcomes were comparable among the remaining 3 groups (Figure). Importantly, all 8 patients with MACE in Group-L had poor outcomes (CVD/MI/urgent PCI/UAP; 2/1/3/2) despite complete revascularization and the prevention of coronary spasm with CCBs, indicating that they might be resistant to standard contemporary therapies. They were characterized by less frequent use of angiotensin convert enzyme inhibitor (0 vs. 47.6%, P=0.02) and higher prevalence of multi-vessel organic lesions (37.5 vs. 4.8%, P=0.052) compared with those without MACE.

Figure 1

Conclusions

These results provide the first evidence that evaluation of coronary functional abnormalities with FFR is useful for making therapeutic strategies in VSA patients with organic coronary stenosis.

P4158Marked impairment of endothelium-dependent digital vasodilatations in patients with microvascular angina compared with those with vasospastic angina

Background/Introduction

Nitric oxide (NO) and endothelium-dependent hyperpolarization (EDH) factor are the major endothelium-derived relaxing factors. NO plays an important role in conduit arteries, while the importance of EDH factor increases as the vessel size decrease in patients with microvascular angina (MVA) compared with those with vasospastic angina (VSA) remains to be fully elucidated.

Purpose

We evaluated the roles of NO and EDH factor in conduit (brachial) arteries and resistance (digital) arteries of the patients with MVA, VSA and comorbid MVA+VSA patients.

Methods

We enrolled 39 patients who underwent diagnostic cardiac catheterization and divided them into 3 groups based on acetylcholine (ACh) provocation test, index of microcirculation resistance (IMR), and coronary flow reserve (CFR); MVA (N=9, mean age 59.9±3.5 years), VSA (N=12, mean age 61.3±1.8 years), and comorbid MVA+VSA (N=18, mean age 64.0±2.2 years). Endothelium-dependent brachial and digital vasodilatations in response to intra-arterial infusion of bradykinin (BK, 25, 50, and 100 ng/min for 2 min) were simultaneously measured by ultrasonography and peripheral arterial tonometry, respectively. Measurements were repeated after oral administration of aspirin (486 mg) and intra-arterial infusion of NG-monomethyl-L-arginine (L-NMMA, 8μmol/min for 5 min) in order to inhibit the effects of vasodilator prostaglandins and NO, respectively. Finally, endothelium-independent brachial and digital vasodilatations in response to sublingual nitroglycerin (NTG, 0.3 mg) were measured in the same manner.

Results

In the brachial artery, dose-dependent vasodilatations to BK were comparable among the 3 groups, and L-NMMA equally attenuated the responses to BK (Figure 1). Endothelium-independent brachial vasodilatation in response to NTG was also comparable among the 3 groups. Surprisingly, dose-dependent digital vasodilatations to BK were almost absent in MVA patients compared with VSA or comorbid MVA+VSA group (Figure 2). Furthermore, the digital vasodilatations were unaffected by L-NMMA in VSA group, but were significantly reduced in comorbid MVA+VSA group (VSA, 16.8±15.1% vs. MVA+VSA, −0.23±6.2%, P<0.05), suggesting reduced EDH and compensatory role of NO in the latter group. In contrast, endothelium-independent digital vasodilatation in response to NTG was comparable among the 3 groups.

The main results of this study

Conclusions

These results provide the first evidence that endothelium-dependent digital vasodilatations (both NO and EDH factor) are markedly impaired in MVA patients compared with VSA or comorbid MVA+VSA patients, whereas the responses are comparable in the brachial artery among the 3 groups, suggesting the involvement of severe endothelial dysfunction in the pathogenesis of MVA.

2381Low-intensity pulsed ultrasound ameliorates DES-induced coronary adventitial inflammation and hyperconstricting responses in pigs in vivo - A novel non-invasive therapy for coronary inflammation

Background

We previously demonstrated that coronary adventitial inflammation plays important roles in the pathogenesis of coronary artery spasm, including drug-eluting stent (DES)-induced coronary hyperconstricting responses, in pigs and humans. Indeed, the coronary adventitia has recently attracted much attention as the important site for vascular inflammation. However, a direct therapeutic approach to the coronary adventitia remains to be developed. We have developed a non-invasive low-intensity pulsed ultrasound (LIPUS) therapy for angina, which exerts anti-inflammatory effects through improved coronary microcirculation.

Purpose

In this study, we aimed to examine whether our LIPUS therapy ameliorates DES-induced coronary hyperconstricting responses in pigs in vivo, and if so, what mechanisms are involved.

Methods

An everolimus-eluting stent (EES) was implanted into the left anterior descending (LAD) coronary artery in normal male pigs. They were randomly assigned to the LIPUS or the sham therapy groups. After EES implantation, in the LIPUS group, LIPUS (32 cycles, 193 mW/cm2) was applied to the heart at 3 different levels (proximal and distal stent edges and middle portion of the stent) through X-ray for 20 min at each level for every other day for 2 weeks (6 days in total) (Figs. 1A, 1B). The sham therapy group was treated in the same manner but without LIPUS. At 4 weeks after the procedure, we performed coronary angiography to examine coronary vasoconstricting responses to intracoronary serotonin in vivo. Finally, stented coronary vessels were harvested for immunohistochemistry of vasa vasorum, lymphatic vessels (LYVE-1), sympathetic nerve fibers (SNF), vascular inflammation (macrophages and IL-1β expression), Rho-kinase expression and activity as evaluated by phosphorylated myosin phosphatase target subunit-1 (pMYPT-1).

Results

Coronary vasoconstricting responses to intracoronary serotonin were significantly enhanced in the sham therapy group but were significantly suppressed in the LIPUS group at the DES edges in the LAD, whereas those responses were comparable at the non-DES implanted segments in the left circumflex (LCx) coronary arteries between the 2 groups. (Figs. 1C, 1D). Furthermore, in vivo lymph transport speed was significantly faster in the LIPUS group than in sham group (Figs. 1E–1G). Histological analysis showed that except vasa vasorum formation, the number of lymphatic vessels, adventitial inflammatory cells infiltration, Rho-kinase expression and activity were all significantly enhanced in the sham therapy group and were significantly suppressed in the LIPUS group (Figs. 1G–1K).

Figure 1

Conclusion

We were able to develop a non-invasive LIPUS therapy for coronary functional abnormalities caused by chronic adventitial inflammation in pigs in vivo, for which multiple beneficial effects appear to be involved (Fig. 1L).

3332Exercise training ameliorates vasodilator capacity of coronary microvessels in patients with vasospastic angina - A new therapeutic approach for the coronary functional disorder

Background

We have recently demonstrated that coronary vasospasm could develop in both epicardial coronary arteries and intramuscular coronary microvessels in patients with vasospastic angina (VSA). However, it remains to be examined whether vasodilator capacity of coronary microvessels is impaired in VSA patients and if so, whether exercise training could ameliorate vasodilator capacity of coronary microvessels on the top of calcium channel blockers. The effectiveness of exercise training is established for organic coronary artery disease but remained to be examined for VSA.

Purpose

We thus examined whether vasodilator capacity of coronary microvessels is impaired in VSA patients without organic coronary stenosis using an adenosine-stress dynamic computed tomography perfusion (CTP) that can measure absolute value of myocardial blood flow (MBF). We also examined whether exercise training ameliorates not only vasodilator capacity of coronary microvessels but also exercise capacity and frequency of angina attack.

Methods

In the first protocol, we measured MBF using CTP in consecutive 32 VSA patients with acetylcholine-induced diffuse coronary spasm in the left anterior descending coronary arteries (LAD) and 12 non-VSA controls. In the second protocol, we conducted a randomized controlled trial (RCT; Exercise VSA trial, UMIN: ehz745.008423996), where 20 VSA patients were randomly assigned to either exercise group (Ex group: supervised exercise training session for 30-min using bicycle ergometer, once/week at the hospital and more than 3 times/week at home) or non-exercise group (Non-Ex group) (n=10 each) (Figure A). Before and 3 months after exercise training, we measured MBF with adenosine-stress dynamic CTP and peak VO2 by cardiopulmonary exercise tests, and also assessed angina attack with Seattle Angina Questionnaire (SAQ).

Results

In the first protocol, CTP showed that adenosine-stress MBF was significantly decreased in the VSA group compared with the non-VSA group (VSA, 137.2±6.6 vs. Non-VSA, 174.4±10.7 ml/100g/min, P<0.01) (Figure B), although patient characteristics were comparable between the 2 groups. In the second protocol, exercise training was performed safely in all patients, and RCT showed that MBF was significantly increased in the Ex group compared with the non-Ex group (Figures C, D), although patient characteristics were also comparable between the 2 groups. Furthermore, peak VO2 was significantly increased in the Ex group compared with the non-Ex group (Figure E), and frequency of angina was significantly decreased in the Ex group compared with the non-Ex group (Figure F). Finally, there was a significant positive correlation between the extents of the changes in peak VO2 and the SAQ score for angina frequency in the Ex group (P<0.01, R=0.67).

Figures

Conclusions

These results provide the first evidence that vasodilator capacity of coronary microvessels is impaired in VSA patients, which can be ameliorated by exercise training.

P4156Coexistence and prognostic impacts of epicardial and microvascular coronary dysfunctions in patients with chest pain and unobstructive coronary artery disease - Involvement of Rho-kinase activation

Background

Although the importance of coronary functional abnormalities has been emerging, including epicardial coronary spasm (vasospastic angina, VSA) and coronary microvascular dysfunction (CMD), comprehensive evaluation of the abnormalities in the same population remains to be examined.

Purpose

We examined the significance of coronary functional abnormalities in a comprehensive manner for both epicardial and microvascular coronary arteries in patients with chest pain and unobstructive coronary artery disease (CAD) as well as their prognostic impacts.

Methods and results

We prospectively enrolled 187 consecutive patients with suspected angina and unobstructive coronary arteries (M/F 113/74, 63.2±12.3 [SD] yrs.). We performed acetylcholine (ACh) provocation tests for coronary spasm, followed by functional tests for coronary microvascular function, including coronary flow reserve (CFR) and index of microcirculation resistance (IMR) during hyperemic state induced by intravenous adenosine. Among the 187 patients, ACh test identified 128 patients with VSA (68%). There was no significant difference in age, sex, or prevalence of traditional coronary risk factors between the non-VSA and the VSA groups. The median IMR value was significantly higher in the VSA group than in the non-VSA group [17.5 (12.0, 25.3) vs. 14.7 (10.7, 17.8), P=0.02], whereas CFR values were comparable between the 2 groups [2.51 (1.72, 3.35) vs. 2.66 (1.85, 3.64), P=0.34]. During the median follow-up period of 893 days, major adverse cardiac events (MACE), including cardiac death, non-fatal myocardial infarction, and hospitalization due to unstable angina pectoris, occurred in 10 patients (5.3%). Multivariable analysis revealed that IMR correlated with the incidence of MACE [hazard ratio (HR) (95% confidence interval), 1.05 (1.02–1.09), P=0.002] and receiver-operating characteristics curve analysis identified IMR of 18.0 as the optimal cut-off value for the incidence of cardiac events. When we divided the patients into the following 4 groups according to the cut-off value of IMR (>18) and the presence or absence of VSA; G1, IMR <18 without VSA (n=45); G2, IMR ≥18 without VSA (n=14); G3, IMR <18 with VSA (n=67); and G4, IMR ≥18 with VSA (n=61), the Kaplan-Meier survival analysis showed a significantly worse prognosis in G4 compared with other 3 groups (HR [95% CI] 6.23 [1.21–118.46], P=0.002) (Figure 1). Importantly, intracoronary administration of fasudil, a Rho-kinase inhibitor, significantly ameliorated IMR in G4 (P<0.0001) (Figure 2A), and %changes in IMR in response to intracoronary fasudil were more evident in G4 compared with other 3 groups (P<0.0001) (Figure 2B).

Conclusions

These results provide the first evidence that in patients with chest pain and unobstructive CAD, epicardial coronary spasm and increased microvascular resistance are frequently coexisted with worse long-term prognosis, for which Rho-kinase activationmay be involved.

Genetic variation and local differences in Pacific cod Gadus macrocephalus around Japan

The population structure of the Pacific cod Gadus macrocephalus was examined using 15 microsatellite loci and mitochondrial DNA (ND2 region). In total, 274 individuals were sampled from 16 locations around Japan to estimate the level of genetic differentiation and effective population size (N_e ). Pairwise F_ST , analysis of molecular variance and Bayesian clustering analysis suggested the presence of two genetically distinct groups in waters around Japan, with a higher N_e value in the eastern group than in the western group. A possible factor that restricts gene flow between groups may be related to the water temperature differences in the south-western part of the Sea of Japan, where the Tsushima Warm Current flows around the area inhabited by the western group, which may limit migration between the west and east.

Pharmacokinetic and pharmacogenomic modelling of the CYP3A activity marker 4β-hydroxycholesterol during efavirenz treatment and efavirenz/rifampicin co-treatment

OBJECTIVES

To assess the effect of the major efavirenz metabolizing enzyme (CYP2B6) genotype and the effects of rifampicin co-treatment on induction of CYP3A by efavirenz.

PATIENTS AND METHODS

Two study arms (arm 1, n = 41 and arm 2, n = 21) were recruited into this study. In arm 1, cholesterol and 4β-hydroxycholesterol were measured in HIV treatment-naive patients at baseline and then at 4 and 16 weeks after initiation of efavirenz-based antiretroviral therapy. In arm 2, cholesterol and 4β-hydroxycholesterol were measured among patients taking efavirenz during rifampicin-based tuberculosis (TB) treatment (efavirenz/rifampicin) just before completion of TB treatment and then serially following completion of TB treatment (efavirenz alone). Non-linear mixed-effect modelling was performed.

RESULTS

A one-compartment, enzyme turnover model described 4β-hydroxycholesterol kinetics adequately. Efavirenz treatment in arm 1 resulted in 1.74 (relative standard error = 15%), 3.3 (relative standard error = 33.1%) and 4.0 (relative standard error = 37.1%) average fold induction of CYP3A for extensive (CYP2B6*1/*1), intermediate (CYP2B6*1/*6) and slow (CYP2B6*6/*6) efavirenz metabolizers, respectively. The rate constant of 4β-hydroxycholesterol formation [mean (95% CI)] just before completion of TB treatment [efavirenz/rifampicin co-treatment, 7.40 × 10(-7) h(-1) (5.5 × 10(-7)-1.0 × 10(-6))] was significantly higher than that calculated 8 weeks after completion [efavirenz alone, 4.50 × 10(-7) h(-1) (4.40 × 10(-7)-4.52 × 10(-7))]. The CYP3A induction dropped to 62% of its maximum by week 8 of completion.

CONCLUSIONS

Our results indicate that efavirenz induction of CYP3A is influenced by CYP2B6 genetic polymorphisms and that efavirenz/rifampicin co-treatment results in higher induction than efavirenz alone.

New insights into the mechanism of neurolathyrism: L-β-ODAP triggers [Ca2+]i accumulation and cell death in primary motor neurons through transient receptor potential channels and metabotropic glutamate receptors

Neurolathyrism is a motor neuron (MN) disease caused by β-N-oxalyl-L-α,β-diaminopropionic acid (L-β-ODAP), an AMPA receptor agonist. L-β-ODAP caused a prolonged rise of intracellular Ca(2+) ([Ca(2+)]i) in rat spinal cord MNs, and the [Ca(2+)]i accumulation was inversely proportional to the MN's life span. The [Ca(2+)]i rise induced by L-β-ODAP or (S)-AMPA was antagonized completely by NBQX, an AMPA-receptor blocker. However, blocking the L-type Ca(2+) channel with nifedipine significantly lowered [Ca(2+)]i induced by (S)-AMPA, but not that by L-β-ODAP. Tetrodotoxin completely extinguished the [Ca(2+)]i rise induced by (S)-AMPA or kainic acid, whereas that induced by L-β-ODAP was only attenuated by 65.6±6% indicating the prominent involvement of voltage-independent Ca(2+) entry. The tetrodotoxin-resistant [Ca(2+)]i induced by L-β-ODAP was blocked by 2-APB, Gd(3+), La(3+), 1-(β-[3-(4-methoxy-phenyl)propoxy]-4-methoxyphenethyl)-1H-imidazole hydrochloride (SKF-96365) and flufenamic acid, which all are blockers of the transient receptor potential (TRP) channels. Blockers of group I metabotropic glutamate receptors (mGluR I), 7-(hydroxyiminocyclopropan[b]chromen-1α-carboxylate ethyl ester (CPCCPEt) and 2-methyl-6-(phenylethynyl)-pyridine (MPEP) also lowered the [Ca(2+)]i rise by L-β-ODAP. MN cell death induced by L-β-ODAP was prolonged significantly with SKF-96365 as well as NBQX. The results show the involvement of TRPs and mGluR I in L-β-ODAP-induced MN toxicity through prolonged [Ca(2+)]i mobilization, a unique characteristic of this neurotoxin.

Association of a single nucleotide polymorphism in the SH2D1A intronic region with systemic lupus erythematosus

SH2D1A, also known as signaling lymphocytic activation molecule (SLAM)-associated protein (SAP), is an adaptor protein. Recently, it was reported that SAP deficient mice were protected from systemic lupus erythematosus (SLE). In this study, we postulated SH2D1A gene to be a candidate susceptibility gene for SLE and analyzed its association with SLE. A case-control association study was conducted on 5 tag single nucleotide polymorphisms (SNPs) in SH2D1A region in 506 Japanese female SLE patients and 330 healthy female controls. The luciferase assay was performed to determine the functional role of the SNP associated with SLE. One SNP in the intron 2, rs2049995, showed association with SLE (p=0.0110, odds ratio (OR) 1.97, 95% confidence interval (CI) 1.16-3.34, under the dominant model). The association of rs2049995 seemed to be stronger in the subset with the age of onset less than 20 years (p=0.0067, OR 2.65, 95% CI 1.28-5.46). Functional evaluation of rs2049995 showed that reporter gene activity was increased 1.9-fold for the susceptible allele compared with the resistant allele. An intronic SNP of SH2D1A is associated with SLE.

Effect of rifampicin and CYP2B6 genotype on long-term efavirenz autoinduction and plasma exposure in HIV patients with or without tuberculosis

We performed a prospective comparative study to examine, from a pharmacogenetics perspective, the effect of rifampicin (RIF) on long-term efavirenz (EFV) autoinduction and kinetics. In a study population of patients with HIV receiving EFV with RIF (arm 2, n = 54) or without RIF (arm 1, n = 128 controls), intraindividual and interindividual plasma EFV and 8-hydroxyefavirenz levels were compared at weeks 4 and 16 of EFV therapy. In arm 2, RIF was initiated 4 weeks before starting EFV. In controls (arm 1), the plasma EFV was significantly lower whereas 8-hydroxyefavirenz was higher at week 16 as compared to week 4. By contrast, there were no significant differences in plasma EFV and 8-hydroxyefavirenz concentrations over time in arm 2. At week 4, the plasma EFV concentration was significantly lower in arm 2 as compared to arm 1, but no significant differences were observed by week 16. When stratified by CYP2B6 genotype, significant differences were observed only with respect to CYP2B6*1/*1 genotypes. Ours is the first report of the CYP2B6 genotype-dependent effect of RIF on long-term EFV autoinduction.

Long-term efavirenz autoinduction and its effect on plasma exposure in HIV patients

We investigated the influence of gender and pharmacogenetic variations on long-term efavirenz autoinduction and disposition among patients with HIV in Tanzania (N = 129). Plasma concentrations (at 16 h) of efavirenz and 8-hydroxyefavirenz were quantified at weeks 4 and 16 of therapy. Genotyping was performed to identify cytochrome P450 (CYP) 2B6*6, CYP3A5*3, *6, and *7, and ABCB1-3435 C/T genotypes. There were reductions in the median efavirenz concentration (Wilcoxon matched-pair test P < 0.001) and efavirenz/8-hydroxyefavirenz ratio (P < 0.001) by 19 and 32%, respectively, at week 16 as compared with week 4. The proportion of patients with efavirenz concentration <1 µg/ml at week 16 was higher by 67, 25, and 5% in CYP2B6*1/*1, *1/*6, and *6/*6 genotypes, respectively. The defined therapeutic range based on observed plasma concentrations is affected by the time point of sampling and the CYP2B6 genotype. The effect of efavirenz autoinduction on reducing plasma exposure continues up to week 16 and predominantly affects CYP2B6 extensive metabolizers. Among CYP2B6 slow metabolizers, the presence of a CYP3A5 genotype allele is associated with greater effects of efavirenz autoinduction on plasma concentrations of the drug. The cumulative induction may influence the long-term antiretroviral therapy outcome, particularly in CYP2B6*1 carriers.

Prospective comparison of the effects of maxacalcitol and calcitriol in chronic hemodialysis patients with secondary hyperparathyroidism: a multicenter, randomized crossover study

BACKGROUND

Maxacalcitol is a vitamin D analogue, which is administered intravenously for secondary hyperparathyroidism in dialysis patients as well as calcitriol. However, few dose-comparison clinical studies have been reported for these drugs. The present multicenter, randomized crossover study was conducted to determine the equivalence of maxacalcitol and calcitriol doses.

METHODS

Subjects comprised 31 patients on chronic hemodialysis with secondary hyperparathyroidism who had not received maxacalcitol or calcitriol in the previous 3 months. Patients were randomly divided into two groups, and maxacalcitol or calcitriol was administered in a crossover design for 12 weeks each. Maxacalcitol and calcitriol doses were adjusted based on serum levels of calcium and intact parathyroid hormone.

RESULTS

After the 12-week maxacalcitol/calcitriol administration, there were no significant differences in levels of calcium (maxacalcitol 2.40+/-0.22 mmol/1 (9.6+/-0.9 mg/dl), calcitriol 2.42 + 0.25 mmol/l (9.7+/-1.0 mg/dl), p = 0.71), phosphate (maxacalcitol 1.97 + 0.42 mmol/l (6.1+/-1.3 mg/dl), calcitriol 2.00+/-0.48 mmol/l (6.2+/-1.5 mg/dl), p = 0.64), intact parathyroid hormone (maxacalcitol 267+/-169 pg/ml, calcitriol 343+/-195 pg/ml, p = 0.11) in serum or other bone-metabolic parameters such as serum alkaline phosphatase. The doses ofmaxacalcitol and calcitriol were 49.3+/-23.7 microg/month and 9.0+/-3.8 microg/month, respectively, and maxacalcitol : calcitriol dose ratio was 5.5: 1. No severe adverse reactions were seen for either maxacalcitol or calcitriol during the study period.

CONCLUSIONS

Comparable therapeutic efficacy can be obtained in the treatment of secondary hyperparathyroidism using either maxacalcitol or calcitriol at a dose ratio of 5.5 : 1.

A rat model of neurolathyrism: repeated injection of L-?-ODAP induces the paraparesis of the hind legs

Neurolathyrisim is a motor neuron disease characterized by spastic paraparesis in the hind legs, and is caused by grass pea, Lathyrus sativus, which contains the excitotoxic amino acid, 3-N-oxalyl-L: -2,3-diaminopropanoic acid (L: -beta-ODAP), an alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-type glutamatergic receptor agonist. In an attempt to make a useful model of this disease, the CNS distribution and toxicity of L: -beta-ODAP was studied in rat neonates after parenteral administration. L: -beta-ODAP was detected in the spinal cord as well as in the pons/medulla oblongata, though only small amounts in the latter. Repeated injection of L: -beta-ODAP resulted in rats with paraparesis of the legs, though at a low incidence rate of 0.032. These paralyzed rats displayed the severe atrophy of the ventral root of the lumbar cord as well as degenerations of motor neuron. The rats were useful models for the study of motor neuron degeneration in the spinal cord.

Partial involvement of group I metabotropic glutamate receptors in the neurotoxicity of 3-N-oxalyl-L-2,3-diaminopropanoic acid (L-beta-ODAP)

Neurolathyrism is a human motoneuron disease caused by the overconsumption of grass pea (Lathyrus sativus) that contains a toxic non-protein amino acid, 3-N-oxalyl-L-2,3-diaminopropanoic acid (L-beta-ODAP). The preventive activities of various glutamatergic agents from acute neuronal death caused by L-beta-ODAP were studied using rat primary cortical neuron/glia culture. Nearly 80% of the rat primary cortical neurons were killed by 300 microM L-beta-ODAP within 24 h. Though antagonists acting on the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor prevented most of the toxicity, antagonists acting on group I metabotropic glutamatergic receptors (mGluRs), including (RS)-1-aminoindan-1,5-dicarboxylic acid (AIDA), (S)-alpha-methyl-4-carboxyphenylglycine (MCPG), and 2-methyl-6-(2-phenylethenyl)pyridine (SIB1893) partially and significantly prevented neuronal death due to L-beta-ODAP. These antagonists, within limited concentrations, did not have any inhibitory effects on the currents through AMPA receptors expressed in Xenopus oocytes. L-beta-ODAP itself did not induce the currents through group I mGluRs expressed in Xenopus oocytes. These results suggest that the neurotoxicity induced by L-beta-ODAP is partially mediated by the activation of group I mGluRs by an indirect mechanisms.

Content of reticulocyte hemoglobin is a reliable tool for determining iron deficiency in dialysis patients

BACKGROUND

The evaluation of iron status in dialysis patients provides information essential to the planning of adequate recombinant human erythropoietin (rHuEPO) treatment. Iron status of the patients can be determined from the recently available measurement of content of reticulocyte hemoglobin (CHr).

METHODS

In this study, to clarify the accuracy of CHr in diagnosing iron deficiency in hemodialysis (HD) patients, we initially compared CHr with such conventional iron parameters as serum ferritin levels, transferrin saturation and serum soluble transferrin receptor levels. Secondly, we investigated the changes in CHr during iron supplementation for iron-deficient patients to determine whether this marker is a prospective and reliable indicator of iron sufficiency. The participants in this study were 149 hemodialysis (HD) patients and 53 age-matched healthy subjects. Iron deficiency was defined as having a TSAT of less than 20% and serum ferritin of less than 100 ng/ml. Conventional parameters of red blood cells and CHr were measured by an ADVIA120 autoanalyzer.

RESULTS

Mean CHr was 32.3 +/- 2.2 pg in the patients undergoing hemodialysis treatment. CHr significantly correlated with iron parameters in the dialysis patients. Logistic regression analysis was performed to determine the relationship between CHr and each outcome measure, and CHr was the significant multivariate predictor of iron deficiency. Iron supplements given to the patients with low CHr and hematocrit (Hct) significantly increased Hct, resulting in a decrease in the weekly dosage of rHuEPO.

CONCLUSIONS

CHr, measured simultaneously with Hct, is a sensitive and specific marker of iron status in dialysis patients.

Severe complications after hypofractionated high dose rate intracavitary brachytherapy following external beam irradiation for oesophageal carcinoma

The purpose of this study was to evaluate severe complications that developed after high dose rate (HDR) intracavitary brachytherapy for oesophageal carcinoma. Six consecutive patients with oesophageal carcinoma were treated by external beam irradiation (60 Gy in 30 fractions over 6 weeks) followed by hypofractionated intracavitary HDR brachytherapy (10 Gy in 2 fractions). Two of the six patients were alive and well for more than 2-3 years following therapy, but three of the six patients developed treatment-related oesophageal fistulae and died. HDR intracavitary brachytherapy following external beam irradiation is an effective method for radical treatment of oesophageal carcinoma. However, hypofractionated HDR brachytherapy should be used with care.

Computed tomography-guided frameless stereotactic radiotherapy for stage I non-small cell lung cancer: a 5-year experience

PURPOSE

Stereotactic radiotherapy (SRT) is highly effective for brain metastases from non-small-cell lung cancers (NSCLCs). As such, primary lesions of NSCLC may also be treated effectively by similar focal high-dose SRT.

METHODS AND MATERIALS

Between October 1994 and June 1999, 50 patients with pathologically proven T1-2N0 M0 NSCLC were treated by CT-guided frameless SRT. Of these, 21 patients were medically inoperable and the remainder were medically operable but refused surgery. In most patients, SRT was 50-60 Gy in 5-10 fractions for 1-2 weeks. Eighteen patients also received conventional radiotherapy of 40-60 Gy in 20-33 fractions before SRT.

RESULTS

With a median follow-up period of 36 months (range 22-66), 30 patients were alive and disease free, 3 were alive with disease, 6 had died of disease, and 11 had died intercurrently. Local progression was not observed on follow-up CT scans in 47 (94%) of 50 patients. The 3-year overall survival rate was 66% in all 50 patients and 86% in the 29 medically operable patients. The 3-year cause-specific survival rate of all 50 patients was 88%. No definite adverse effects related to SRT were noted, except for 2 patients with a minor bone fracture and 6 patients with temporary pleural pain.

CONCLUSIONS

SRT is a very safe and effective treatment for Stage I NSCLC. Additional studies involving a larger patient population and longer follow-up periods are warranted to assess this new treatment for early-stage lung cancer.

A spatial light modulator based on fused-silica plates for adaptive feedback control of intense femtosecond laser pulses

A novel spatial light modulator (SLM) made of an array of fused-silica plates was developed for the purpose of feedback control for intense femtosecond laser pulses over a wide spectral range. Dispersion compensation for 20-fs pulses from a Ti:sapphire oscillator was successfully demonstrated using the SLM with an adaptive feedback control system. The SLM was also applied to the output pulses from a Ti:sapphire amplifier for compensation of material.

Carcinoma of the uterine cervix: twice- versus once-weekly high-dose-rate brachytherapy

PURPOSE

To compare the effectiveness and safety of once- versus twice-weekly high-dose-rate (HDR) brachytherapy for cervical cancer.

MATERIALS AND METHODS

From 1980 to 1997, 124 consecutive previously untreated patients with cervical cancer were treated with external-beam irradiation (50 Gy) and HDR brachytherapy. Clinical stages were I, 4 (3%) patients; II, 51 (41%); III, 64 (52%); and IV, 5 (4%). From 1980 to 1992, 74 patients (group A) were treated with HDR brachytherapy once weekly (about three fractions of 7 Gy each to point A [2 cm superior and 2 cm lateral to the inferior end of the intrauterine radioactive source]), while from 1992 to 1997, 50 patients (group B) were treated twice weekly (about six fractions of 4.5 Gy each to point A).

RESULTS

Overall survival rate at 5 years was 65.2% in group A and 65.3% in group B (P=.96). Local recurrence-free survival rate at 5 years was 69% (51 of 74 patients) in group A and 90% (45 of 50 patients) in group B (P<.001). The rate of grade 2 (moderate) and grade 3 (severe) complications was significantly lower in group B (6% vs. 32% in group A, P<.001). At multivariate analysis, the variables significantly associated with increased local-regional recurrence rates were having stage III-IV lesions (P=.04) and with fewer than six sessions of HDR brachytherapy (P=.02).

CONCLUSION

The twice-weekly HDR regimen may improve the local control rate with fewer complications.

Local structure analyses of Ce0.5Zr0.5O2 mixed oxides by XAFS

Three types of CeO2-ZrO2 with the same composition (Ce/Zr = 1) were prepared by different methods, exhibited the different oxygen storage/release capacity (OSC). To investigate the relationship between the OSC and the local structure, the Ce and Zr K-edges XAFS spectra for these samples were measured. The features of Fourier transforms of these samples were different from each other. This suggested that the OSC was remarkably exerted by the local structure around Ce and Zr. The quantitative curve-fitting analysis of EXAFS was applied, and it was concluded that homogeneous Ce(0.5)Zr(0.5)O2 solid solution at atomic level exhibited the highest OSC among these CeO2-ZrO2 with the same composition (Ce/Zr = 1).

New insights into the thrombopoietic status of patients on dialysis through the evaluation of megakaryocytopoiesis in bone marrow and of endogenous thrombopoietin levels

The thrombopoietic status of patients with uremia remains unclear. This issue was addressed with particular reference to marrow megakaryocytopoiesis and endogenous thrombopoietin (TPO) levels. A study was conducted in 114 patients on hemodialysis, 43 patients on continuous ambulatory peritoneal dialysis, and 48 age-matched controls. Reticulated platelets, a marker of marrow megakaryocytopoiesis, were measured by flow cytometry. Serum TPO levels, platelet-associated IgG (PAIgG) levels, and hepatitis C virus (HCV) antibody titers were also measured by enzyme-linked immunosorbent assay. Circulating and reticulated platelet counts were significantly lower in the patients on dialysis than in the controls. Thrombocytopenia (less than 150 x 10(9)/L) was most frequent in the HCV-positive hemodialysis patients, who had a higher incidences and higher PAIgG titers. The following results were obtained in the HCV-negative dialysis patients: (1) platelet counts chronologically decreased with years on hemodialysis; (2) platelet counts were associated with the reticulated platelet counts; (3) serum TPO levels were significantly elevated in the dialysis patients, responding to the decrease of reticulated platelets; (4) hematocrits had a positive correlation with serum TPO levels, and serum TPO levels were significantly higher in the patients on hemodialysis who did not require recombinant human erythropoietin therapy than in the other patients. In conclusion, thrombocytopenia is a frequent finding in patients on dialysis. The failure of megakaryocyte production could be the principal cause of the platelet reduction, and the peripheral destruction and sequestration of platelets may be concomitantly involved. Elevation of serum TPO may in part serve as an aid to erythropoiesis in dialysis patients.

Intrafractional tumor position stability during computed tomography (CT)-guided frameless stereotactic radiation therapy for lung or liver cancers with a fusion of CT and linear accelerator (FOCAL) unit

PURPOSE

To evaluate intrafractional tumor position stability during computed tomography (CT)-guided frameless stereotactic radiation therapy (SRT) for lung or liver cancers, we checked repeated CT scanning, with a fusion of CT and linear accelerator (FOCAL) unit.

METHODS AND MATERIALS

The FOCAL unit is a combination of a linear accelerator (Linac), CT scanner, X-ray simulator (X-S), and carbon table, and is designed to achieve CT-guided SRT with daily CT positioning followed by immediate irradiation while patients keep reduced shallow respirations. To evaluate intrafractional tumor position stability, 50 lung or liver lesions in 20 patients were checked by repeated CT scanning just before and after irradiation, and the obtained images were compared.

RESULTS

There was no case with the intrafractional error judged to be greater than 10 mm. In 68% of cases, the intrafractional positioning errors were negligible (0-5 mm).

CONCLUSIONS

Using the FOCAL unit, SRT for lung or liver cancers could be performed with intrafractional positioning errors not greater than 10 mm.