d-Serine Increases Release of Acetylcholine in Rat Submandibular Glands

d-serine has been observed in submandibular gland tissue in rats, but its functions remain to be clarified. Oral administration of d-serine, but not l-serine, increased its concentrations in the submandibular gland and pilocarpine-induced salivary secretion. In vivo microdialysis was used to collect the d- and l-enantiomers of amino acids from local interstitial fluid in the rat submandibular gland. The proportion of the d-form of serine in interstitial fluid was higher than that in plasma or saliva. Perfusion of the rat submandibular gland with d-serine and l-glutamic acid via the submandibular gland artery resulted in a significant increase in salivary secretion after stimulation of muscarinic receptors with carbachol. In vivo microdialysis applied to the submandibular glands of rats showed that infusion of d-serine along with l-glutamate through the microdialysis probe significantly elevated acetylcholine levels in local interstitial fluids in the submandibular glands of anesthetized rats as compared to that with l-glutamate alone in an N-methyl-d-aspartate receptor glycine site antagonist-sensitive manner. These results indicate that d-serine augments salivary secretion by increasing acetylcholine release in the salivary glands.

P1252Diagnostic performance of quantitative flow ratio from coronary angiography versus fractional flow reserve from computed tomography

Background

QFR and FFRCT are recently developed, less-invasive techniques for functional assessment of coronary artery disease.

Objectives

We compared the diagnostic performance between fractional flow reserve derived from computed tomography (FFRCT) and quantitative flow ratio (QFR) derived from coronary angiography, using FFR as the standard reference.

Methods

We measured FFRCT, QFR and FFR in 152 patients (233 vessels) with stable coronary artery disease.

Results

QFR was highly correlated with FFR (r=0.78, p<0.001), while FFRCT was moderately correlated with FFR (r=0.63, p<0.001). Both QFR and FFRCT showed good agreements with FFR, presenting small values of mean difference and root-mean-squared deviation (FFR -QFR: 0.02±0.09 and FFR -FFRCT: 0.03±0.11). The AUC of QFR was significantly greater than that of 3D-QCA-derived %DS (0.93 vs. 0.78; difference: 0.15; 95% CI: 0.09 to 0.20; p<0.001). The AUC of FFRCTwas significantly greater than that of CCTA-derived %DS (0.82 vs. 0.70; difference: 0.12; 95% CI: 0.05 to 0.19; p<0.001). The AUC of QFR was significantly greater than that of FFRCT (0.93 vs. 0.82; difference: 0.11; 95% CI: 0.05 to 0.16; p<0.001). The sensitivity, specificity, positive predictive value, and negative predictive valueof QFR ≤0.80 for predicting FFR ≤0.80 were 90%, 82%, 81%, and 90%, respectively. Those of FFRCT ≤0.80 for predicting FFR ≤0.80 were 82%, 70%, 70%, and 82%, respectively. The diagnostic accuracy of QFR ≤0.80 for predicting FFR ≤0.80 was 85% [95% confidence interval: 81% to 89%], while that of FFRCT≤0.80 for predicting FFR ≤0.80was 76% [95% confidence interval: 70% to 80%].

Figure 1. Comparison of FFR ≤0.80 predictors

Conclusions

Both QFR and FFRCTpossessed the ability to accurately evaluate the functional severity of coronary stenosis.

6108Efficacy of the PCSK9 inhibitor for lipid-rich coronary plaque reduction: a near-infrared spectroscopy analysis

Background

Recently, some studies have highlighted proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors produce incremental low-density lipoprotein cholesterol (LDL-C) lowering effect. However, it is unknown whether the lipid composition of plaque changes is associated with serum LDL-C reduction due to PCSK9 inhibitors administration.

Purpose

The purpose of this study was to determine the effects of PCSK9 inhibitor (PCSK9i) on coronary plaque component in patients with a history of coronary artery disease (CAD) assessed by near-infrared spectroscopy intravascular ultrasound (NIRS-IVUS).

Methods

A total of 67 non-culprit coronary segments were identified in 34 patients. These lesions were analyzed utilizing NIRS-IVUS at baseline and follow-up coronary angiography (CAG). The subjects were divided into two groups according to lipid-lowering treatment; administration of PCSK9i group (PCSK9i: 19 segments, 9 patients) and traditional statin treatment group (Control: 48 segments, 25 patients). The change of lipid-rich plaque distribution between baseline and follow-up NIRS-IVUS was defined as the change of maximal lipid core burden index (LCBI) score for each of the 4-mm longitudinal segments (maxLCBI4mm).

Results

Mean duration from baseline to follow-up CAG was 239.4±52.4 days in the PCSK9i group and 341.0±84.1 days in the Control group (p<0.001). Despite the higher total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in the PCSK9i group at baseline (206.6±40.9 mg/dl vs. 168.5±37.1 mg/dl, 131.5±35.4 mg/dl vs. 100.0±29.5 mg/dl; respectively, p<0.001 for both), the PCSK9i group was significantly lower TC and LDL-C at the follow-up (111.5±23.5 mg/dl vs. 157.4±27.8 mg/dl, 40.8±15.7 mg/dl vs. 86.2±19.6 mg/dl; respectively, p<0.001 for both). Furthermore, the PCSK9i group induced greater regression of maxLCBI4mm than that of Control group (99.6±156.6 vs. 27.9±118.0, p=0.046) (Figure).

Figure 1

Conclusion

Compared with traditional statin therapy, PCSK9i treatment resulted in a greater decrease in lipid component in non-culprit coronary plaques. Therefore, PCSK9i may be useful option in preventing from adverse coronary events for the patients with CAD.

P974Efficacy of plaque debulking for bifurcated or ostial lesion by directional coronary atherectomy before 2nd generation drug eluting stent (PERFECT2)

Objectives

We sought to evaluate the efficacy of plaque debulking by directional coronary atherectomy (DCA) before 2nd generation drug-eluting stent (DES) implantation for bifurcated coronary lesions.

Background

Percutaneous coronary intervention (PCI) for bifurcated lesions still remains complex and challenging in terms of restenosis or stent thrombosis regardless of whether simple or complex stenting used.

Methods

Patients with bifurcated lesions were enrolled in this prospective multicenter registry. Pre-2nd generation DES plaque debulking with a novel DCA was conducted. All patients were scheduled to perform a follow up (9–12 months) angiography (coronary angiography or coronary computed tomography). The primary end point was the target vessel failure (TVF) at follow-up. Secondary end points were procedure-related events and major adverse cardiac events at 1 year.

Results

A total of 77 patients with bifurcated lesions were enrolled. PCI with DCA was performed successfully in all without any major procedure-related event and only 1 case needed complex stenting. TVF rate at 9–12 months follow up was 3.9% (3 of 77) and those were all associated with revascularization of the target vessel. Restenosis was only observed at ostial of main-branch in 3cases. No death, no coronary artery bypass grafting, and no myocardial infarction were reported in the patients within the first year.

Figure1

Conclusion

DCA before 2nd generation DES implantation can possibly avoid complex stenting and provide a good mid-term outcome in patients with bifurcated lesions.

Acknowledgement/Funding

None

Post-occlusional hyperemia for fractional flow reserve assessment and pull-back curve analysis

Balloon occlusion is a potential method for inducing hyperemia to measure post-percutaneous coronary intervention (PCI) fractional flow reserve (FFR). The objective of this study was to determine the clinical usefulness of post-occlusional hyperemia. FFRs measured using post-occlusional hyperemia caused by 30 (FFR_occl30) and 60 s (FFR_occl60) of balloon occlusion after PCI were compared in 60 lesions from 60 patients. The duration of hyperemia was also measured. There was a strong correlation between FFR_occl30 and FFR_occl60 (r = 0.969, p < 0.01). The duration of hyperemia was significantly longer with FFR_occl60 than with FFR_occl30 (68 ± 23 vs. 37 ± 15 s, p < 0.01). The time required for pullback curve analysis was around 45 s. However, in 7 (12%) cases, the duration of hyperemia with FFR_occl60 was < 45 s, which was not enough for pull-back curve analysis. To predict the duration of hyperemia with FFR_occl60 ≥ 45 s, the receiver operating characteristic curve analysis revealed a cut-off value of 25 s of hyperemia with FFR_occl30. FFR_occl30 is sufficient for diagnostic purposes. FFR_occl60 is suitable for pull-back curve analysis in select cases based on predictions made using the duration of hyperemia with FFR_occl30.

Angiogram based fractional flow reserve in patients with dual/triple vessel coronary artery disease

OBJECTIVE

To assess the performance of angiography derived Fractional Flow Reserve (FFRangio) in multivessel disease (MVD) patients undergoing angiography.

BACKGROUND

FFR is the reference standard for physiologic assessment of coronary stenosis and guidance of revascularization, especially in patients with MVD, yet it remains grossly underutilized. The non-wire based FFRangio performs well in non-MVD patients, but its accuracy in MVD is unknown.

METHODS

A prospective clinical study was conducted at Gifu Heart Centre, Japan. Patients underwent physiologic assessment of all relevant coronary lesions using wire-based FFR (wbFFR) and FFRangio. Primary outcome was diagnostic performance (sensitivity, specificity, accuracy) for FFRangio with wbFFR as reference. Other outcomes were the correlation between wbFFR/FFRangio, time required for wbFFR/FFRangio measurements, and the effect of wbFFR/FFRangio on the reclassification of coronary disease severity.

RESULTS

Fifty patients (118 lesions in total) were included. Mean age was 72 ± 9 years, 72% were male, 36% had triple vessel disease and the average SYNTAX score was 13. The mean measurement of wbFFR and FFRangio were 0.83 ± 0.12 and 0.81 ± 0.11, respectively. Accuracy, sensitivity and specificity for FFRangio were 92.3% (95% CI 79.1-98.4%), 92.4% (95% CI 84.3-97.2%) and 92.4% (95% CI 87.4-97.3%), respectively. Pearson's r between wbFFR and FFRangio was 0.83. FFRangio measurement was faster than wbFFR (9.6 ± 3.4 vs. 15.0 ± 8.9 min, p < 0.001).

CONCLUSIONS

In patients with MVD, FFRangio shows good correlation and excellent diagnostic performance compared to wbFFR, and measuring FFRangio is faster than wbFFR. These results highlight the potential clinical benefits of utilizing FFRangio among patients with MVD.

The effects of 2,3-dimercapto-1-propanesulfonic acid (DMPS) and meso-2,3-dimercaptosuccinic acid (DMSA) on the nephrotoxicity in the mouse during repeated cisplatin (CDDP) treatments

Previously, we reported that specific lower dose of sodium 2,3-dimercapto-1-propanesulfonic acid (DMPS) which is an antidote to heavy metal intoxication, inversely enhanced cisplatin (CDDP)-induced antitumor activity to S-180 cell-bearing mouse. This activity was only weak with meso-2,3-dimercaptosuccinic acid (DMSA), however. This study investigated the effects of lower doses of DMPS or DMSA on the nephrotoxicity and kinetics of CDDP. Kidney and blood isolated from female mice which received CDDP with or without DMPS or DMSA once daily for 4 days were provided for measuring levels of blood urea nitrogen (BUN) and transporter proteins (OCT2: organic cation transporter; MATE1: multidrug and toxin extrusion) mRNA, and CDDP-originated platinum, and TUNEL staining of renal tubular cells. DMPS or DMSA reduced effectively CDDP-induced BUN, and caused a moderate reduction of platinum in kidney. Additionally, both dimercapto-compounds restored the CDDP-reduced mRNA levels of transporter proteins (OCT2 and MATE1), and apparently suppressed the CDDP-induced apoptosis. These results suggest that DMPS, as well as DMSA, at approximate 17-fold dose (μmol/kg) of CDDP, has an enough potential to reverse the CDDP nephrotoxicity, and concomitant use of DMPS considering both dose and timing for administration is potentially useful for preventing nephrotoxicity and enhancing antitumor activity during CDDP chemotherapy.

Probing the local structure of Prussian blue electrodes by 113Cd NMR spectroscopy

We demonstrate that ¹¹³Cd NMR is a potent technique to monitor the local electronic and structural states of the Prussian blue electrode during Li⁺ intercalation, providing an atomic-scale insight into the reaction mechanism.

Rebamipide, an anti-ulcerative drug, inhibits induction of salivary dysfunction by benzodiazepines

OBJECTIVES

The purpose of this study was to determine whether rebamipide, an antistomach ulcer agent, ameliorated benzodiazepine-induced hyposalivation in rat parotid gland (PG) and submandibular gland (SMG).

METHODS

Saliva was collected from PG and SMG through a capillary cannula inserted into the parotid duct and sublingual papillae, respectively, every 15 min for 1 h after stimulation with pilocarpine dissolved in physiological saline and intraperitoneally administered at 1 mg kg^-1 . Diazepam (DZP) was administered intraperitoneally at a dose of 0.2 mg kg^-1 twice daily for 7 days. Rebamipide was administered at 10, 20, 30, or 100 mg kg^-1 concomitantly with DZP to determine its effect on hyposalivation. The effect of rebamipide on movement of intracellular calcium ([Ca²⁺ ]i) in isolated parotid acinar cells was analyzed using Fluo4, a fluorescent dye used to detect Ca²⁺ .

RESULTS

Repetitive administration of DZP decreased salivary secretion in PG and SMG. This inhibitory effect was weakened by administration of rebamipide. Prior administration of DZP (10^-6 M) significantly suppressed carbachol (10^-7 M)-induced increase in [Ca²⁺ ]i. This inhibitory effect was ameliorated by combined use with rebamipide (5 × 10^-4 M).

CONCLUSION

This findings suggest that rebamipide weakens the downregulatory effect of DZP on salivary secretion by preventing DZP-induced suppression of increase in [Ca²⁺ ]i.

Characterization of Motor Neuron Prostaglandin E2 EP3 Receptor Isoform in a Mouse Model of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a motor neuron disease with adult onset, characterized by progressive loss of motor neurons. Prostaglandin E2 (PGE2), a lipid mediator, exerts its biological functions by binding to four subtypes of E-prostanoid (EP1-4). Among them, EP3 has been shown to have multiple isoforms, EP3α, EP3β, and EP3γ, produced by alternative splicing. Since PGE2 has been shown to have important pathophysiological roles in ALS, experiments were performed to identify EP3 receptor isoform(s) in spinal motor neurons of wild-type (WT) and ALS model (G93A) mice. Reverse transcription-polymerase chain reaction (RT-PCR) analysis of adult mice demonstrated expression of EP3α and EP3γ mRNAs in the lumbar spinal cord, whereas EP3β mRNA was barely detectable. Laser capture microdissection was used to dissect out motor neurons from frozen samples of lumbar spinal cord in these mice for analysis by real-time PCR. We found that expression of EP3γ mRNA was predominant in these neurons, whereas EP3α and EP3β mRNAs were undetectable. At the early symptomatic stage, the mRNA expression profiles of these splice isoforms in G93A motor neurons were comparable to those in neurons from WT mice. These results suggest that the PGE2-to-EP3 signaling pathway is mediated mainly by the EP3γ isoform in the motor neurons of mice, and that modulation of the EP3γ isoform in motor neurons may be a promising new therapeutic approach for ALS.

mRNA expression and localization of LPS-induced β-defensin isoforms in rat salivary glands

β-defensins are small, cationic peptides with broad-spectrum antimicrobial activity that are produced by mucosal epithelia. However, little is known about the expression of β-defensins in the major salivary glands. The purpose of this study was to characterize expression of rat β-defensin-1 (RBD-1) and -2 (RBD-2) mRNA within the major salivary glands together with the effect of injection of intraductal lipopolysaccharide (LPS) on that expression. β-defensin mRNA expression was quantitated by RT-PCR in salivary gland tissues and salivary acinar and striated duct cells collected by laser captured microdissection. RBD-1 and -2 were expressed in the parotid gland, the submandibular gland, and the sublingual gland. β-defensins were expressed in both the acinar and striated duct cells of the major salivary glands. Intraductal injection of LPS increased expression of RBD-1 and -2 mRNA, which peaked at 12 hrs. These results suggest that salivary cells (acinar and striated duct cells) have the potential to produce β-defensins.

Contributions of ADP and ATP to the increase in skeletal muscle blood flow after manual acupuncture stimulation in rats

OBJECTIVE

To investigate the contributions of adenosine triphosphate (ATP) and adenosine diphosphate (ADP) to the increase in skeletal muscle blood flow (MBF) observed following manual acupuncture (MA) stimulation in rats.

METHODS

Male Sprague-Dawley rats were used as experimental animals (300-370 g, n=40). MA was applied to the right tibialis anterior muscle (TA) for 1 min using a stainless steel acupuncture needle. In eight rats, high-performance liquid chromatography with the microdialysis technique was used to measure local extracellular concentrations of ATP, ADP, adenosine monophosphate (AMP), and adenosine in the TA. In the remaining 32 rats, fluorescent microspheres (15 µm in diameter) were used to measure MBF in the TA following pre-treatment with either the P2 receptor antagonist suramin (100 mg/kg intra-arterially) or saline (control) (n=16 each). Rats receiving MA (Suramin+MA and Saline+MA groups, n=8 each) were compared with untreated rats (Suramin and Saline groups, n=8).

RESULTS

MA significantly increased the local extracellular concentration of ATP, ADP, and adenosine (p<0.05, before MA vs 30 min after MA). In addition, MA significantly increased MBF in rats pre-treated with saline or suramin (p<0.01, Saline vs Saline+MA; p<0.05, Suramin vs Suramin+MA, respectively). However, suramin significantly suppressed this MA-induced increase in MBF (p<0.05, Saline+MA vs Suramin+MA).

CONCLUSIONS

These results suggest that both ATP and ADP partially contribute to the MA-induced increase in MBF via P2 receptors. However, further studies are needed to clarify the contributions of other vasodilators.

Synthesis of micrometer-sized poly(methyl methacrylate) particles by microsuspension iodine transfer polymerization (ms ITP)

Micrometer-sized poly(methyl methacrylate) (PMMA) particles were successfully prepared without submicrometer-sized by-products for the first time by applying microsuspension iodine transfer polymerization with iodoform as a chain transfer agent.

Dosimetric evaluation of compensator intensity modulation-based stereotactic body radiotherapy for Stage I non-small-cell lung cancer

OBJECTIVE

To evaluate the dosimetry of compensator intensity modulation-based stereotactic body radiotherapy (SBRT) [non-coplanar intensity-modulated radiotherapy (ncIMRT)], its use was compared with that of three-dimensional conformation-based SBRT, for patients with Stage I non-small-cell lung cancer (NSCLC).

METHODS

21 consecutive patients with Stage I NSCLC were treated with ncIMRT or SBRT at Tokyo Medical University. To compare the two techniques, ncIMRT and SBRT plans for each patient were generated, where the planning target volume (PTV) coverages were adjusted to be equivalent to each other. The prescribed dose was set as 75 Gy in 30 fractions. PTV coverage, conformity index, conformation number (CN) and homogeneity index (HI) were used to compare the two strategies.

RESULTS

There was no statistically significant difference between PTV coverage for the 100%, 95% and 90% dose levels in the SBRT plan and those in the ncIMRT plan. The CN values were 0.53 ± 0.13 in the SBRT plan and 0.72 ± 0.10 in the ncIMRT plan. These values were significantly better than those of the SBRT plan (p < 0.001). The HI in the ncIMRT plan was 1.04 ± 0.03%, which was also significantly better than that of SBRT.

CONCLUSION

The ncIMRT plan provided superior conformity and reduced the doses to the lung for patients with Stage I NSCLC.

ADVANCES IN KNOWLEDGE

The delivery technique with compensator intensity modulation-based SBRT was evaluated. Concerning target motion, this is thought to be more robust and safer than SBRT for early-stage NSCLC.

Patients with severe emphysema have a low risk of radiation pneumonitis following stereotactic body radiotherapy

OBJECTIVE

To evaluate the risk of radiation pneumonitis (RP) after stereotactic radiotherapy (SBRT) for patients presenting with severe pulmonary emphysema.

METHODS

This study included 40 patients with Stage I non-small-cell lung cancer who underwent SBRT, 75 Gy given in 30 fractions, at the Tokyo Medical University, Tokyo, Japan, between February 2010 and February 2013. The median age of the patients was 79 years (range, 49-90 years), and the male:female ratio was 24:16. There were 20 T1 and 20 T2 tumours. 17 patients had emphysema, 6 had slight interstitial changes on CT images and the remaining 17 had no underlying lung disease. The level of emphysema was classified into three groups according to the modified Goddard's criteria (severe: three patients, moderate: eight patients and mild: six patients). Changes in the irradiated lung following SBRT were evaluated by CT.

RESULTS

On CT images, RP was detected in 34 (85%) patients, and not in 6 (15%) patients, during a median observation period of 313 days. Of the six patients, three had severe emphysema and three had no underlying lung disease. Patients with severe emphysema had lower risk of RP than those with moderate emphysema (p = 0.01), mild emphysema (p = 0.04) and no underlying lung disease (p = 0.01).

CONCLUSION

Patients with severe emphysema had a low risk of RP following SBRT.

ADVANCES IN KNOWLEDGE

Little is known about the association between RP and pulmonary emphysema. Patients with severe emphysema had lower risk of RP than those with no underlying lung disease.