Iodine contrast volume reduction in preoperative transcatheter aortic valve implantation computed tomography: Comparison with 64- and 256-multidetector row computed tomography

INTRODUCTION

This study aimed to compare the vascular enhancement and radiation dose in preoperative transcatheter aortic valve implantation (TAVI) computed tomography (CT) with a reduced contrast medium (CM) using volume scans in 256-multidetector row CT (MDCT) with a standard CM using 64-MDCT.

METHODS

This study included 78 patients with preoperative TAVI CT with either 64- or 256-MDCT. The CM was injected at 1.5 mL/kg in the 64-MDCT group and 1.0 mL/kg in the 256-MDCT group. We compared vascular enhancement of the aortic root and access routes, image quality (IQ) scores, and radiation dose in both groups.

RESULTS

Despite the reduced CM (by 33 %) in the 256-MDCT group, the mean vascular enhancement of the right and left subclavian arteries was significantly higher than that in the 64-MDCT group [284 and 267 Hounsfield units (HU) vs. 376 and 359 HU; p < 0.05]; however, no significant differences in the mean vascular enhancement in the ascending aorta, abdominal aorta at the celiac level, and bilateral common femoral arteries were observed between the two groups (p > 0.05 for all). The median IQ scores at the aortic root were higher in the 256-MDCT group than in the 64-MDCT group (3 vs. 4; p < 0.05), and those at the femoral access routes were comparable (4 vs. 4; p = 0.33). The mean effective dose was significantly reduced by 30 % in the 256-MDCT group (23.6 vs. 16.3 mSv; p < 0.05).

CONCLUSION

In preoperative TAVI CT, volume scans using 256-MDCT provide comparable or better vascular enhancement and IQ with a 30 % reduction in CM and radiation dose than those using 64-MDCT.

IMPLICATIONS FOR PRACTICE

Volume scan using 256-MDCT for preoperative TAVI CT may reduce CM and radiation dose in TAVI patients with renal dysfunction.

Contrast Injection from an Intermediate Catheter Placed in an Intradural Artery is Associated with Contrast-Induced Encephalopathy following Neurointervention

BACKGROUND AND PURPOSE

Contrast-induced encephalopathy can result from neurotoxicity of contrast medium in the affected area. The development of intermediate catheters has allowed guidance of catheters to more distal arteries. This study focused on the association between contrast-induced encephalopathy and contrast injection from an intermediate catheter guided into a distal intradural artery during neurointervention for cerebral aneurysms.

MATERIALS AND METHODS

We retrospectively reviewed 420 consecutive aneurysms in 396 patients who underwent neurointervention for extracranial aneurysms and unruptured intracranial aneurysms at our institution from February 2012 to January 2023. Patients were divided into a group with contrast-induced encephalopathy and a group without. To identify risk factors for contrast-induced encephalopathy, we compared clinical, anatomic, and procedural factors between groups by multivariate logistic regression analysis and stepwise selection.

RESULTS

Among the 396 patients who underwent neurointervention for cerebral aneurysms, 14 (3.5%) developed contrast-induced encephalopathy. Compared with the group without contrast-induced encephalopathy, the group with contrast-induced encephalopathy showed significantly higher rates of patients on hemodialysis, previously treated aneurysms, intradural placement of a catheter for angiography, nonionic contrast medium, and flow-diversion procedures in univariate analyses. Stepwise multivariate logistic regression analysis revealed intradural placement of a catheter for angiography (OR = 40.4; 95% CI, 8.63-189) and previously treated aneurysms (OR = 8.20; 95% CI, 2.26-29.6) as independent predictors of contrast-induced encephalopathy.

CONCLUSIONS

Contrast injection from an intradural artery and retreatment of recurrent aneurysms were major risk factors for contrast-induced encephalopathy. Attention should be paid to the location of the intermediate catheter for angiography to avoid developing contrast-induced encephalopathy.

Distal Vessel Imaging via Intra-arterial Flat Panel Detector CTA during Mechanical Thrombectomy

BACKGROUND AND PURPOSE

Obtaining information on invisible vasculature distal to the occlusion site helps to deploy a stent retriever safely during mechanical thrombectomy for large-vessel occlusion. It is essential to reduce the amount of contrast used for detecting the vessels distal to the occlusion site because acute ischemic stroke patients tend to have chronic kidney disease and patients with severe chronic kidney disease are at an increased risk of contrast-associated acute kidney injury. We assessed whether vessels distal to the occlusion site during acute ischemic stroke with large-vessel occlusion could be visualized on angiographic images using flat panel detector CT acquired following intra-arterial diluted contrast injection, compared with MRA findings.

MATERIALS AND METHODS

Between May 2019 and January 2020, we enrolled 28 consecutive patients with large-vessel occlusions of the anterior circulation eligible for mechanical thrombectomy following MR imaging. The patients underwent CBV imaging using flat panel detector CT with an intra-arterial diluted contrast injection instead of intravenous injection. Flat panel detector CT angiographic images reconstructed from the same dataset were evaluated for image quality, collateral status of the MCA territory, and visualization of the vessels distal to the occlusion site. These findings were compared with MRA findings.

RESULTS

Twenty-two patients were retrospectively examined. Flat panel detector CT angiographic image quality in 20 patients (91%) was excellent or good. The distal portion of the occluded vessel segment was visualized in 14 patients (70%), while the proximal portion of the segment adjacent to the occluded vessel in 3 (15%) was visualized. No visualization was observed in only 1 patient (5%) with no collateral supply. Flat panel detector CT angiographic images were shown to evaluate vessels distal to the occlusion site more accurately than MRA.

CONCLUSIONS

In acute ischemic stroke with large-vessel occlusion, flat panel detector CT angiographic images could successfully visualize vessels distal to the occlusion site with a small amount of contrast material.

Usefulness of Muscle Synergy Analysis in Individuals With Knee Osteoarthritis During Gait

OBJECTIVE

To clarify whether there are any muscle synergy changes in individuals with knee osteoarthritis, and to determine whether muscle synergy analysis could be applied to other musculoskeletal diseases.

METHODS

Subjects in this study included 11 young controls (YC), 10 elderly controls (EC), and 10 knee osteoarthritis patients (KOA). Gait was assessed on a split-belt treadmill at 3 km/h. A non-negative matrix factorization (NNMF) was applied to the electromyogram data matrix to extract muscle synergies. To assess the similarity of each module, we performed the NNMF analysis assuming four modules for all of the participants. Further, we calculated joint angles to compare the kinematic data between the module groups.

RESULTS

The number of muscle modules was significantly lower in the EC (2-3) and KOA (2-3) groups than in the YC group (3-4), which reflects the merging of late swing and early stance modules. The EC and KOA groups also showed greater knee flexion angles in the early stance phase. Contrarily, by focusing on the module structure, we found that the merging of early and late stance modules is characteristic in KOA.

CONCLUSION

The lower number of modules in the EC and KOA groups was due to the muscle co-contraction with increased knee flexion angle. Contrarily, the merging of early and late stance modules are modular structures specific to KOA and may be biomarkers for detecting KOA.

SIGNIFICANCE

Describing the changes in multiple muscle control associated with musculoskeletal degeneration can serve as a fundamental biomarker in joint disease.

Delayed Leukoencephalopathy: A Rare Complication after Coiling of Cerebral Aneurysms

BACKGROUND AND PURPOSE

Delayed leukoencephalopathy is a rare complication that occurs after endovascular coiling of cerebral aneurysms. We aimed to describe a clinical picture of delayed leukoencephalopathy and explore potential associations with procedural characteristics.

MATERIALS AND METHODS

We considered endovascular coiling procedures for cerebral aneurysms performed between January 2006 and December 2017 in our institution with follow-up MRIs. We used logistic regression models to estimate the ORs of delayed leukoencephalopathy for each procedural characteristic.

RESULTS

We reviewed 1754 endovascular coiling procedures of 1594 aneurysms. Sixteen of 1722 (0.9%) procedures demonstrated delayed leukoencephalopathy on follow-up FLAIR MR imaging examinations after a median period of 71.5 days (interquartile range, 30-101 days) in the form of high-signal changes in the white matter at locations remote from the coil mass. Seven patients had headaches or hemiparesis, and 9 patients were asymptomatic. All imaging-associated changes improved subsequently. We found indications suggesting an association between delayed leukoencephalopathy and the number of microcatheters used per procedure (P = .009), along with indications suggesting that these procedures required larger median volumes of contrast medium (225 versus 175 mL, OR = 5.5, P = .008) as well as a longer median fluoroscopy duration (123.6 versus 99.3 minutes, OR = 3.0, P = .06). Our data did not suggest that delayed leukoencephalopathy was associated with the number of coils (P = .57), microguidewires (P = .35), and guiding systems (P = .57).

CONCLUSIONS

Delayed leukoencephalopathy after coiling of cerebral aneurysms may have multiple etiologies such as foreign body emboli, contrast-induced encephalopathy, or hypersensitivity reaction to foreign bodies.

Randomized, phase II trial of sequential hepatic arterial infusion chemotherapy and sorafenib versus sorafenib alone as initial therapy for advanced hepatocellular carcinoma: SCOOP-2 trial

Background

The efficacy of hepatic arterial infusion chemotherapy (HAIC) for advanced hepatocellular carcinoma (HCC) remains unclear. We conducted a multi-center randomized phase II study comparing a sequential HAIC-sorafenib regimen versus sorafenib alone as an initial therapy for HCC.

Methods

Patients were randomly assigned (ratio, 1:1) to receive sequential HAIC with cisplatin followed by sorafenib (HAIC group, n = 35) or sorafenib alone (sorafenib group, n = 33) as an initial therapy. The primary endpoint was the one-year survival rate. Secondary endpoint included overall survival (OS), the 2-year survival rate, the time-to-progression (TTP), the objective response rate (ORR), the disease control rate (DCR), and safety.

Results

For the primary endpoint, the one-year survival rates were 46% in the HAIC group and 58% in the sorafenib group. The median OS period was 10.0 months (95% CI, 7.0–18.8) in the HAIC group and 15.2 months (95% CI, 8.2–19.7) in the sorafenib group (hazard ratio [HR], 1.08; 95% CI, 0.63 to 1.86, P = 0.78). The median TTP, ORR and DCR in the HAIC group were 2.8 months (95% CI, 1.7–5.5), 14.3, and 45.7%, respectively, while those in the sorafenib group were 3.9 months (95% CI, 2.3–6.8), 9.1, and 45.5%, respectively. No unexpected adverse events related to HAIC or sorafenib were observed in either group.

Conclusions

Sequential HAIC with cisplatin and sorafenib does not improve the survival benefit, compared with sorafenib alone, when used as an initial therapy for advanced HCC. However, this study was underpowered in regard to its primary and secondary endpoints, so the results should be interpreted with caution.

Trial registration

UMIN ID 000006147, registration data: August 11, 2011.

Agreement of intracranial vessel diameters measured on 2D and 3D digital subtraction angiography using an automatic windowing algorithm

BACKGROUND AND PURPOSE

Precise vessel measurement plays a major role in size selection of stents used for the treatment of intracranial aneurysms and became even more critical after the introduction of flow diverter stents. We assessed agreement between intracranial vessel diameters of aneurysm patients measured on 2D digital subtraction (2D DSA) and 3D volume rendering digital subtraction angiography (3D DSA) images using an automatic windowing algorithm.

MATERIALS AND METHODS

Ten patients with intracranial aneurysms were enrolled and 120 measurement points were selected on both 2D and 3D DSA images acquired by a biplane angiographic system. Automatic windowing was applied to the 3D DSA images. Inter-method agreement of vessel measurements on 2D and 3D DSA images was assessed by Bland Altman plots and intraclass correlation coefficients (ICC). Inter- and intra-rater agreement of measurements on 3D DSA images were assessed by ICCs.

RESULTS

The mean differences between measurements on 2D and 3D DSA images were 0.14mm for the ICA, and 0.18mm for the ACA and MCA, which is about the size of one 3D DSA image voxel. For ICA measurements, inter-method, inter-rater and intra-rater agreements were good or excellent (consistency and absolute ICC≥0.95). For ACA and MCA measurements, the inter-method, inter-rater and intra-rater agreements were also good or excellent (consistency ICC=0.94, 0.89 and 0.93, absolute ICC=0.83, 0.84 and 0.85 respectively).

CONCLUSIONS

Vessel diameters may be measured on 3D DSA images with sufficient reliability for clinical use when applying an automatic windowing algorithm.

Survival Outcomes of Two Phase 2 Studies of Adjuvant Chemotherapy with S-1 Plus Oxaliplatin or Capecitabine Plus Oxaliplatin for Patients with Gastric Cancer After D2 Gastrectomy

BACKGROUND

Two phase 2 trials of oxaliplatin-containing adjuvant therapy for patients with gastric cancer (GC) after D2 gastrectomy were conducted in Japan. The SOXaGC trial evaluated the tolerability and safety of adjuvant therapy with S-1 plus oxaliplatin (SOX), whereas the J-CLASSIC trial evaluated the feasibility of adjuvant therapy with capecitabine plus oxaliplatin (CAPOX). Because both were studies that did not evaluate survival results as study end points, the authors evaluated the survival outcomes for the patients in the two trials.

METHODS

All 62 and 100 patients in the full analysis set of the SOXaGC and J-CLASSIC trials, respectively, were included in the current study. Their information about survival outcome was collected. The primary end point was relapse-free survival (RFS), and the secondary end point was overall survival (OS).

RESULTS

For the pathologic stage (pStage 2) patients treated with CAPOX, the 3-year RFS rate was 87.8% and the 3-year OS rate was 92.7%. For the pStage 3 patients treated with SOX and CAPOX, the 3-year RFS rates were respectively 70.9% and 67.8% (hazard ratio [HR], 0.93; 95% confidence interval [CI], 0.50-1.72), whereas the 3-year OS rates were respectively 75.7% and 79.3% (HR, 1.10; 95% CI, 0.54-2.26). Subgroup analysis showed significant interactions between the treatment (SOX vs. CAPOX) and both sex (male vs. female; P = 0.024) and histologic type (diffuse vs. other, P = 0.069).

CONCLUSIONS

This exploratory analysis demonstrated that SOX and CAPOX are suggested to have similar efficacy for pStage 3 GC patients after D2 gastrectomy. Differences in the treatment effect according to sex and histologic type warrant further evaluation.

Three-year outcomes of two phase II studies of adjuvant chemotherapy with S-1 plus oxaliplatin or capecitabine plus oxaliplatin in patients with stage III gastric cancer after D2 gastrectomy

94

Background: Two phase II trials of oxaliplatin-based adjuvant chemotherapy for patients (pts) with gastric cancer (GC) after D2 gastrectomy have been conducted in Japan; the J-CLASSIC study of capecitabine plus oxaliplatin (CAPOX) and the SOXaGC study of S-1 plus oxaliplatin (SOX). In the current study, we evaluated survival outcomes of the two trials. Methods: The J-CLASSIC, enrolling stage II and III pts from 12 centers between July 2012 and July 2013, evaluated eight cycles of CAPOX. The SOXaGC, enrolling stage III pts from 11 centers between July 2013 and February 2014, evaluated seven cycles of SOX after one cycle of S-1 monotherapy. The two studies were conducted sequentially and most centers (9 centers) participated in both trials. In this pooled analysis, we updated relapse-free survival (RFS) and overall survival (OS) information. The median follow-up time was 49 months in the J-CLASSIC and 39 months in the SOXaGC. Results: Fifty-nine stage III pts treated with CAPOX and 62 stage III pts treated with SOX were analyzed. The 3-year RFS and OS rates of SOX were 70.9% (57.8-80.5%) and 75.7% (63.0-84.6%), respectively, whereas the 3-year RFS and OS rates of CAPOX were 67.8% (54.3-78.1%) and 79.3% (66.5-87.7%), respectively. The hazard ratio (HR) of SOX in comparison to CAPOX was 0.925 (0.498-1.720) for RFS, suggesting the efficacy of the two treatments was similar. Trend of a different efficacy was observed in some particular subgroups; the HR for RFS was 1.732 (0.506-5.927) in the intestinal type and 0.735 (0.353-1.528) in the diffuse type, while that was 2.008 (0.447-9.016) in stage IIIA, 0.872 (0.266-2.857) in stage IIIB, and 0.597 (0.258-1.383) in stage IIIC. Conclusions: This is the first report of survival follow-up in Japanese GC pts with oxaliplatin-based adjuvant chemotherapy, which suggests comparable outcomes in both treatments for stage III GC. Different trend in the treatment effect by histologic type or stage warrants further evaluation in a larger cohort. Clinical trial information: UMIN000026883.

Aqueous and Vitreous Penetration of Levofloxacin after Topical and/or Oral Administration

PURPOSE

To investigate the aqueous and vitreous penetration of levofloxacin, the drug was administered topically and/or orally to patients undergoing vitrectomy.

METHODS

Thirty-six patients undergoing initial vitrectomy with phacoemulsification and aspiration (PEA) were enrolled, and were divided randomly into three groups. Group 1 was treated with topical application of levofloxacin (three times on the day before surgery and seven times on the day of surgery), Group 2 received oral administration of levofloxacin (200 mg twice on the day before surgery and 200 mg at 3 hours before surgery), and Group 3 received both topical and oral levofloxacin according to the above schedules. The concentration of levofloxacin was measured in aqueous humor and vitreous fluid samples obtained during surgery.

RESULTS

In Groups 1, 2, and 3, the mean levofloxacin concentration in aqueous humor was 0.765+/-0.624 micro g/mL, 1.279+/-0.440 micro g/mL, and 1.823+/-0.490 micro g/mL, respectively, while the mean levofloxacin concentration in vitreous fluid was <0.02 micro g/mL, 1.455+/-0.445 micro g/mL, and 1.369+/-0.530 micro g/mL, respectively.

CONCLUSIONS

Oral administration of levofloxacin at a dose of 400 mg/day was sufficient for the prophylaxis of ocular infections, because the drug concentrations in both aqueous humor and vitreous fluid were higher than the MIC90 values for major ocular pathogens. Topical application of levofloxacin achieved adequate drug levels in aqueous humor, but not in vitreous fluid, while combined topical and oral administration had an additive effect on the drug concentration in aqueous humor.

Surgical Results of Combined Pars Plana Vitrectomy, Phacoemulsification, and Intraocular Lens Implantation for various Vitreoretinal Diseases

PURPOSE

To evaluate the results and complications of combined pars plana vitrectomy (PPV), phacoemulsification and aspiration (PEA), and intraocular lens (IOL) implantation.

METHODS

A total of 117 eyes from 114 patients who had undergone PPV combined with PEA and IOL implantation were retrospectively analyzed. Combined surgery was performed for a wide variety of vitreoretinal diseases. Intraoperative and postoperative complications were also reviewed.

RESULTS

The postoperative BCVA improved by 2 lines or more in 85 eyes (72.6%). Intraoperative complications consisted of retinal tears in 14 eyes (12.0%) and posterior capsular rupture in 2 eyes (1.7%). Iatrogenic retinal tears occurred more frequently in eyes with a macular hole than in eyes with any other disease (p=0.005, chi-square test). Postoperative complications consisted of posterior capsule opacification (PCO) (21 eyes), transient IOP elevation (29 eyes), vitreous hemorrhage (6 eyes), anterior chamber fibrin exudation (11 eyes), posterior iris synechia (8 eyes), neovascular glaucoma (1 eye), and recurrent retinal detachment (RD) (2 eyes). Fibrin exudation occurred more frequently in eyes with proliferative diabetic retinopathy (PDR) and RD than in eyes with any other disease (p=0.03, chi-square test). PCO occurred more frequently in eyes with PDR than in eyes with any other disease (p=0.03, chi-square test).

CONCLUSIONS

The present study suggests that a high success rate can be achieved when recently improved PPV techniques are combined wi th PEA and IOL implantation. The complications that were observed following this combined treatment varied with respect to the vitreoretinal disease present prior to surgery.

Activation of the catalytic function of formaldehyde dehydrogenase for formate reduction by single-electron reduced methylviologen

The kinetic properties of formate reduction to formaldehyde with formaldehyde dehydrogenase (FldDH) using single-electron reduced methylviologen (MV˙) as a co-enzyme were clarified.

Development and inter-laboratory study of a method for quantifying zearalenone in pet foods

An analytical method for quantifying zearalenone (ZEA) in pet foods using a liquid chromatograph-atmospheric pressure chemical ionization-mass spectrometer (LC-APCI-MS) was developed, and an inter-laboratory study was conducted. ZEA was extracted from pet food samples with aqueous acetonitrile. The extract was purified using a multifunctional column, MultiSep 226 Aflazon+, and analysed with LC-APCI-MS. The limit of quantification of ZEA by this method was estimated to be 0.2 mg/kg for dry and semi-dry pet foods, and 0.1 mg/kg for wet pet food. The calibration curve of ZEA for this method showed linearity in the range of 0.1-10 ng of ZEA (0.01-1.0 µg/ml, 0.04-4.0 mg/kg matrix). The mean recoveries, repeatabilities, reproducibilities, and the HorRats for ZEA from the inter-laboratory validation study were 99.0-102%, 2.2-3.0%, 5.6-6.6%, and 0.33-0.36, respectively.

Association of the clinical efficacy of vancomycin with the novel pharmacokinetic parameter area under the trough level (AUTL) in elderly patients with hospital-acquired pneumonia

WHAT IS KNOWN AND OBJECTIVE

The pharmacokinetic-pharmacodynamic parameter that best predicts the efficacy of vancomycin is the ratio of the area under the concentration versus time curve (AUC) to the minimum inhibitory concentration (MIC). A 24-h AUC (AUC24 )/MIC ratio ≥ 400 was recommended in an American consensus review, but vancomycin treatment occasionally fails despite maintenance of AUC24 /MIC ≥ 400. We evaluated the association between clinical efficacy of vancomycin and two novel pharmacokinetic parameters, the 'area under the trough level' (AUTL) and the 'area above the trough level' (AATL), in hospitalized elderly patients with methicillin-resistant Staphylococcus aureus (MRSA) pneumonia.

METHODS

The subjects were hospitalized elderly patients who were administered vancomycin for treatment of MRSA pneumonia between 2006 and 2012 at Sasebo Chuo Hospital (Nagasaki, Japan). Pharmacokinetic parameters of vancomycin were estimated for each patient by Bayesian analysis using population pharmacokinetic parameters for Japanese patients. Based on the patient-specific parameters thus obtained, AUC24 values were calculated as the vancomycin dosage divided by vancomycin clearance. AUTL was calculated as the trough serum concentration multiplied by 24 h, whereas AATL was calculated by subtracting AUTL from AUC24 .

RESULTS AND DISCUSSION

Logistic regression analysis demonstrated that efficacy of vancomycin was more strongly associated with AUTL than AUC24 . The optimal cut-off value of AUTL was 331 μg∙h/mL, which means that the optimal cut-off value of the trough serum concentration was 13·8 μg/mL.

WHAT IS NEW AND CONCLUSION

Efficacy of vancomycin was associated with AUTL, a novel pharmacokinetic parameter. Determining the target AUTL or trough concentration may enhance the efficacy of vancomycin therapy in elderly patients with MRSA pneumonia. Given that nephrotoxicity may increase with a Ctrough in excess of 15 μg/mL, this level should ideally not be exceeded.

Cost-Effectiveness Analysis of the Diagnosis and Treatment of Primary Aldosteronism in Japan

Approximately 10% of cases of hypertension in Japan are caused by primary aldosteronism (PA), amounting to about 4 million patients in total. Primary aldosteronism due to unilateral aldosterone hypersecretion is potentially curable by adrenalectomy. The clinical benefits of identifying and treating PA have been reported internationally, but its cost-effectiveness is unclear. We examined whether diagnosing and treating hidden PA in hypertensive population was cost-effective compared with suboptimal treatment. Our hypothetical patient was a 50-year-old man diagnosed with stage I-III hypertension. We established a Markov decision model based on plausible clinical pathways and prognoses of PA. We applied cost-effectiveness analysis comparing a comprehensive diagnostic strategy for PA (measurement of plasma aldosterone/renin ratio, 2 loading tests, imaging, and selective adrenal venous sampling) with a suboptimal strategy to manage hypertension by medication unless the typical signs of PA or other complication were manifest. Outcome measures were expected costs, expected effectiveness, and incremental cost-effectiveness ratio. The robustness of the findings was established by one-way and scenario sensitivity analyses. The comprehensive PA diagnostic strategy increased the expected costs by 64 004 JPY and expected life-years by 0.013 compared with standard treatment. The incremental cost-effectiveness ratio for the diagnosis of PA was 4 923 385 JPY per year. Our findings were sensitive to the outcomes of screening and treatment, and the costs of continuous or periodic medication for hypertension and the treatment of stroke and its complications.

High-Resolution C-Arm CT and Metal Artifact Reduction Software: A Novel Imaging Modality for Analyzing Aneurysms Treated with Stent-Assisted Coil Embolization

BACKGROUND AND PURPOSE

Combination of high-resolution C-arm CT and novel metal artifact reduction software may contribute to the assessment of aneurysms treated with stent-assisted coil embolization. This study aimed to evaluate the efficacy of a novel Metal Artifact Reduction prototype software combined with the currently available high spatial-resolution C-arm CT prototype implementation by using an experimental aneurysm model treated with stent-assisted coil embolization.

MATERIALS AND METHODS

Eight experimental aneurysms were created in 6 swine. Coil embolization of each aneurysm was performed by using a stent-assisted technique. High-resolution C-arm CT with intra-arterial contrast injection was performed immediately after the treatment. The obtained images were processed with Metal Artifact Reduction. Five neurointerventional specialists reviewed the image quality before and after Metal Artifact Reduction. Observational and quantitative analyses (via image analysis software) were performed.

RESULTS

Every aneurysm was successfully created and treated with stent-assisted coil embolization. Before Metal Artifact Reduction, coil loops protruding through the stent lumen were not visualized due to the prominent metal artifacts produced by the coils. These became visible after Metal Artifact Reduction processing. Contrast filling in the residual aneurysm was also visualized after Metal Artifact Reduction in every aneurysm. Both the observational (P < .0001) and quantitative (P < .001) analyses showed significant reduction of the metal artifacts after application of the Metal Artifact Reduction prototype software.

CONCLUSIONS

The combination of high-resolution C-arm CT and Metal Artifact Reduction enables differentiation of the coil mass, stent, and contrast material on the same image by significantly reducing the metal artifacts produced by the platinum coils. This novel image technique may improve the assessment of aneurysms treated with stent-assisted coil embolization.

Mutation in insulin receptor attenuates oxidative stress and apoptosis in pancreatic beta-cells induced by nutrition excess: reduced insulin signaling and ROS

Type 2 diabetes results from the failure of beta-cells to adequately compensate for insulin resistance. Although the reduction of beta-cell mass is because of increased cell death and/or inadequate replication or neogenesis, the mechanism underlying beta-cell mass reduction is not fully understood. Here, we clarify the role of insulin signaling pathway in the beta-cell apoptosis using insulin resistant model mice. Wild-type mice and those carrying a mutation in the insulin receptor (mIR) were fed either regular chow or a high-fat diet for 6 weeks and subsequently investigated for beta-cell apoptosis, endoplasmic reticulum stress, and oxidative stress. Insulin tolerance tests revealed that mIR mice fed a high-fat diet (mIRHF) had higher insulin resistance. Beta-cell apoptosis was increased 2-fold in the wild-type mice fed a high-fat diet (wHF) compared with control mice, whereas beta-cell apoptosis in mIRHF mice did not increase compared with that in mIR mice. The expression of endoplasmic reticulum stress markers in isolated islets did not differ between the groups. Staining of 8-hydroxy-2'-deoxyguanosine and 4-hydroxy-2-nonenal in islets of wHF mice significantly increased, but the staining in mIRHF mice was not different from that in control group. Gene expression of the antioxidant enzyme MnSOD was significantly higher in mIRHF mice than those in the other 3 groups. A mutation in the insulin receptor attenuated the oxidative stress and apoptosis in beta-cells even though high caloric nutrient was loaded. Our results suggest that reduced insulin signaling protects beta-cells thorough decline of oxidative stress.

Development and inter-laboratory study of a method for quantification of fumonisin B1, B2 and B3 in pet foods

An analytical method to determine fumonisin B1 (FB1), B2 (FB2) and B3 (FB3) in pet foods using a liquid chromatography-electrospray ionization-mass spectrometer (LC-ESI-MS) was developed, and an inter-laboratory study was conducted in eleven laboratories. FB1, FB2 and FB3 were extracted with aqueous acetonitrile. The extract was purified by a multifunctional column, MultiSep 211 Fum, and analysed by LC-ESI-MS. The limit of quantification of fumonisins was estimated to be 0.2 mg/kg for dry and semi-dry pet foods, and 0.1 mg/kg for wet pet food. The calibration curve showed linearity in the range of 0.1-5 ng of fumonisins (0.02-1.0 μg/ml). The values of the mean recovery for FB1 at 0.1-1.0 mg/kg were 93.3-107% and of the relative standard deviation less than 7.9%. These values were 87.3-102 and 8.6% for FB2 and 90.8-102 and 8.6% for FB3, respectively. The mean recovery, repeatability, reproducibility and the Horwitz ratio for FB1 from the inter-laboratory validation study were 92.9-98.9%, 2.6-4.6%, 6.8-10% and 0.41-0.54, respectively. The values for FB2 were 91.5-94.7%, 2.7-5.9%, 6.8-8.9% and 0.33-0.55, respectively, and the values for FB3 were 90.1-94.3%, 3.3-5.9%, 7.3-9.5% and 0.44-0.57, respectively.

Biphasic modulation by mGlu5 receptors of TRPV1-mediated intracellular calcium elevation in sensory neurons contributes to heat sensitivity

BACKGROUND AND PURPOSE

Elevation of glutamate, an excitatory amino acid, during inflammation and injury plays a crucial role in the reception and transmission of sensory information via ionotropic and metabotropic receptors. This study aimed to investigate the mechanisms underlying the biphasic effects of metabotropic glutamate mGlu5 receptor activation on responses to noxious heat.

EXPERIMENTAL APPROACH

We assessed the effects of intraplantar quisqualate, a non-selective glutamate receptor agonist, on heat and mechanical pain behaviours in mice. In addition, the effects of quisqualate on the intracellular calcium response and on membrane currents mediated by TRPV1 channels, were examined in cultured dorsal root ganglion neurons from mice.

KEY RESULTS

Activation of mGlu5 receptors in hind paw transiently increased, then decreased, the response to noxious heat. In sensory neurons, activation of mGlu5 receptors potentiated TRPV1-mediated intracellular calcium elevation, while terminating activation of mGlu5 receptors depressed it. TRPV1-induced currents were potentiated by activation of mGlu5 receptors under voltage clamp conditions and these disappeared after washout. However, voltage-gated calcium currents were inhibited by the mGlu5 receptor agonist, even after washout.

CONCLUSIONS AND IMPLICATIONS

These results suggest that, in sensory neurons, mGlu5 receptors biphasically modulate TRPV1-mediated intracellular calcium response via transient potentiation of TRPV1 channel-induced currents and persistent inhibition of voltage-gated calcium currents, contributing to heat hyper- and hypoalgesia.

Natural course of dissecting vertebrobasilar artery aneurysms without stroke

BACKGROUND AND PURPOSE

The natural history and therapeutic management of dissecting vertebrobasilar aneurysms without ischemic or hemorrhagic stroke (nonstroke dissecting vertebrobasilar aneurysms) are not well-established. We conservatively followed patients with nonstroke dissecting vertebrobasilar aneurysms and evaluated the factors related to clinical and morphologic deterioration.

MATERIALS AND METHODS

One hundred thirteen patients were enrolled and divided by clinical presentation at diagnosis: asymptomatic (group 1, n = 52), pain only (group 2, n = 56), and mass effect (group 3, n = 5). Patients were conservatively managed without intervention and antithrombotic therapy. Clinical outcomes and morphologic changes were analyzed.

RESULTS

A total of 113 patients who were diagnosed with nonstroke dissecting vertebrobasilar aneurysm had a mean follow-up of 2.9 years (range, 27 days to 8 years). Throughout that period, 1 patient in group 1 (1.9%) and 1 patient in group 2 (1.8%) showed clinical deterioration due to mass effect, and 1 patient in group 3 (20%) developed ischemic stroke followed by subarachnoid hemorrhage. Most patients (97.3%) were clinically unchanged. Three patients who had clinical deterioration showed aneurysm enlargement (P < .001). Aneurysms remained morphologically unchanged in 91 patients (80.5%). Aneurysm enlargement was seen in 5 patients (4.4%); risk of enlargement was significantly associated with either maximum diameter (hazard ratio = 1.30; 95% CI, 1.11-11.52; P = .001) or aneurysm ≥10 mm (hazard ratio = 18.0; 95% CI, 1.95-167; P = .011).

CONCLUSIONS

The natural course of these lesions suggests that acute intervention is not always required and close follow-up without antithrombotic therapy is reasonable. Patients with symptoms due to mass effect or aneurysms of >10 mm may require treatment.

Therapy-related myelodysplastic syndrome and acute myeloid leukemia following chemotherapy (paclitaxel and carboplatin) and radiation therapy in ovarian cancer: a case report

In recent years, the incidence of therapy-related myelodysplastic syndrome (t-MDS) and therapy-related acute myeloid leukemia (t-AML) that occur during chemotherapy for ovarian cancer has increased. While alkylating agents and topoisomerase II inhibitors are particularly mutagenic and have strong leukemogenic potential, paclitaxel and combination chemotherapy/radiation therapy also appear to induce t-MDS. The present authors report a case of t-MDS that developed during chemotherapy and radiation therapy for ovarian cancer. The patient was a 75-year-old woman who received six courses of cyclophosphamide/doxorubicin/cisplatin (CAP) therapy after initial surgery for Stage IIIc grade ovarian cancer in 1995. Beginning in February 2005, the patient experienced multiple recurrences due to sternal metastasis. Chemotherapy, including paclitaxel and carboplatin (TC), was administered intermittently and was combined with radiation therapy to a sternal metastatic lesion. Pancytopenia was observed in December 2008, and she was diagnosed with t-MDS (WHO subtype, refractory cytopenias with multilineage dysplasia [RCMD]): the time from first chemotherapy to t-MDS onset was 106 months. Without evidence of blast crisis, the recurrent lesions continued to grow and caused multiple cerebral infarctions, from which she eventually died. The cumulative doses of paclitaxel and carboplatin administered to this patient were 1,968 mg and 6,480 mg, respectively.

Validation and initial application of a semiautomatic aneurysm measurement software: a tool for assessing volumetric packing attenuation

BACKGROUND AND PURPOSE

Precise aneurysm measurements and volume embolization ratios are essential for long-term durability of endovascular coil embolization. We evaluated the accuracy of newly developed semiautomatic cerebral aneurysm measurement software, NeuroVision, and explored the value of volume embolization ratio in the prediction of re-treatment.

MATERIALS AND METHODS

We compared software-derived volume measurements of 4 silicone aneurysm models with those calculated with an approximation formula and ground truth values (validation study). We used NeuroVision to retrospectively evaluate outcomes of 100 unruptured aneurysms (97 patients) treated with embolization (clinical study). Aneurysm size (height, width, and neck), volume, and volume embolization ratios were calculated for 3 groups (stable, recanalization, and re-treatment) and were compared.

RESULTS

This validation study illustrated higher accuracy of NeuroVision in computing aneurysm volume compared with an approximation formula: percentage absolute errors were 4.50% ± 3.18% and 23.07% ± 17.60%, with maximal percentage absolute errors of 8.99% and 45.63%, respectively. Of 100 unruptured aneurysms, 20 recanalized and 12 were re-treated. Average volume embolization ratios of stable and re-treated aneurysms were 24.88% ± 5.91% and 20.50% ± 4.06%, respectively (P ≤ .01). The optimal volume embolization ratio cutoff point for re-treatment was < 19.15%, at which the Youden index was 0.50 (sensitivity, 58.33%; specificity, 87.50%; area under the receiver operating characteristic curve, 0.74).

CONCLUSIONS

The NeuroVision software provided accurate aneurysm volume measurements and may be a useful standardized tool to measure aneurysm size and volume, especially for multicenter clinical studies. Volume embolization ratio may be a valuable predictor of aneurysm occlusion changes.

Analyses of shape of eyes and structure of optic nerves in eyes with tilted disc syndrome by swept-source optical coherence tomography and three-dimensional magnetic resonance imaging

PURPOSE

To evaluate the deeper structures of the optic nerve and to analyze the shape of eyes with tilted disc syndrome (TDS) by swept-source optical coherence tomography (OCT) and three-dimensional magnetic resonance imaging (3D MRI).

METHODS

The medical records of 54 eyes of 36 patients with TDS were reviewed. The patients with TDS and high myopia were analyzed separately from those without high myopia. All the eyes were examined with a swept-source OCT, and 22 of the eyes were examined by 3D MRI.

RESULTS

A total of 38 eyes of 29 patients were highly myopic and 16 eyes of 15 patients were not highly myopic. The representative OCT findings of the optic disc were: a sloping of the lamina cribrosa posteriorly from the upper part to the lower part, a protrusion of the upper edge of Bruch's membrane, and choroid. The distance and the depth of the most protruded point from the fovea were significantly greater in the eyes with non-highly myopic TDS than those with highly myopic TDS. In the 3D MRI, the lower part of the posterior segment was protruded outward, and the optic nerves attached at the upper nasal edge of the protrusion.

CONCLUSIONS

The abnormalities detected by swept-source OCT and 3D MRI analyses indicate the possibility that the essential pathology of TDS is a deformity of the inferior globe below the optic nerve, and the positional relation between the fovea and the inferior protrusion determines the degree of myopia.

Programmed necrosis, not apoptosis, is a key mediator of cell loss and DAMP-mediated inflammation in dsRNA-induced retinal degeneration

There is no known treatment for the dry form of an age-related macular degeneration (AMD). Cell death and inflammation are important biological processes thought to have central role in AMD. Here we show that receptor-interacting protein (RIP) kinase mediates necrosis and enhances inflammation in a mouse model of retinal degeneration induced by dsRNA, a component of drusen in AMD. In contrast to photoreceptor-induced apoptosis, subretinal injection of the dsRNA analog poly(I : C) caused necrosis of the retinal pigment epithelium (RPE), as well as macrophage infiltration into the outer retinas. In Rip3(-/-) mice, both necrosis and inflammation were prevented, providing substantial protection against poly(I : C)-induced retinal degeneration. Moreover, after poly(I : C) injection, Rip3(-/-) mice displayed decreased levels of pro-inflammatory cytokines (such as TNF-α and IL-6) in the retina, and attenuated intravitreal release of high-mobility group box-1 (HMGB1), a major damage-associated molecular pattern (DAMP). In vitro, poly(I : C)-induced necrosis were inhibited in Rip3-deficient RPE cells, which in turn suppressed HMGB1 release and dampened TNF-α and IL-6 induction evoked by necrotic supernatants. On the other hand, Rip3 deficiency did not modulate directly TNF-α and IL-6 production after poly(I : C) stimulation in RPE cells or macrophages. Therefore, programmed necrosis is crucial in dsRNA-induced retinal degeneration and may promote inflammation by regulating the release of intracellular DAMPs, suggesting novel therapeutic targets for diseases such as AMD.

Justification of unruptured intracranial aneurysm repair: a single-center experience

BACKGROUND AND PURPOSE

Whether to treat UIAs is controversial. The aim of the study was to compare the clinical outcome of patients with UIAs who were either treated conservatively or preventively.

MATERIALS AND METHODS

Patients with UIAs referred to our institution were prospectively enrolled in the study. Data collected included baseline characteristics, aneurysmal features, and procedural and follow-up information. Preventive treatment was recommended if the aneurysm was larger than 5 mm and was considered safely treatable. Endovascular surgery was the first-line therapy if the aneurysmal shape was appropriate for coiling.

RESULTS

From January 2003 through April 2008, a total of 879 patients with 1110 UIAs were enrolled; 325 patients with 369 UIAs (mean size, 7.8 mm) were treated (treatment group), and 603 patients with 741 UIAs (mean size, 4.4 mm) were managed conservatively (observation group). Mean follow-up was 692.5 days (1405.5 person-years). In the observation group, 26 aneurysms (3.5%) had ruptured (1.8% per year; 1405.5 person-years), 10 patients died, and 7 were disabled (mRS, 3-6: 2.8%). Aneurysmal size was a significant risk factor for rupture (P = .001). The treatment group included aneurysms treated either with coiling (n=315), clipping (n=32), or a combined approach (n=9); 1 patient died, and 3 were disabled (mRS, 3-6: 1.2%). Therapeutic intervention was equal (UIAs of all sizes) or superior (UIAs > 5 mm; P = .025) to conservative management.

CONCLUSIONS

Treatment of UIAs was justified in aneurysms larger than 5 mm, and EVS can be safely applied to nearly 90% of UIAs.

Characteristics of intrachoroidal cavitation located temporal to optic disc in highly myopic eyes

PURPOSE

To investigate the anatomic characteristics of eyes with pathological myopia and peripapillary intrachoroidal cavitation (ICC) located temporal to the optic disc.

METHODS

A total of 125 with pathologic myopia were scanned with swept-source optical coherence tomography (OCT). Temporal ICC was defined as ICC located temporal to the optic disc seen in horizontal OCT section through the optic disc center. Definition of pathologic myopia was refractive error >8.00 diopters (D) or an axial length >26.5 mm.

RESULTS

In all, 17 eyes of 16 patients had temporal ICC. All of the eyes had temporal or temporally wider annular conus. The ICC was observed temporal to the optic disc in 15 of 17 eyes, and 2 of the remaining eyes also had inferior ICC. Even in the two eyes with both temporal and inferior ICC, the temporal ICC was much wider than the inferior ICC. Inner retinal defect at the border of conus and temporal ICC was detected in two eyes. The temporal ICC was extensive in the posterior fundus with the average width of 1467.8 ± 1328.1 μm (range; 442-6200 μm) in a horizontal section. In two eyes, the temporal ICC extended beyond the central fovea.

CONCLUSIONS

Peripapillary ICC can develop temporal to the optic disc without involving the area inferior to optic disc in highly myopic eyes. Temporal ICC appeared much wider than inferior ICC, which is usually restricted to the area around the optic disc. The possible reasons why ICC develops in temporal to the optic disc are presented.

Perivascular epithelial cell tumor arising from polypoid adenomyoma: a case report

The present report describes a rare case of a uterine perivascular epithelioid cell tumor (PEComa) arising from a polypoid adenomyoma. The patient, a 44-year-old woman with tuberous sclerosis, was incidentally found to have a uterine mass with malignant-appearing features on a computed tomography (CT) scan. Pathological examination of the hysterectomy specimen demonstrated that the tumor was composed of pale, spindle-shaped, epithelioid tumor cells which were positive for SMA and HMB-45. These findings were consistent with a PEComa arising from a polypoid adenomyoma.

Surgical treatment outcomes of serious chronic tubo-ovarian abscess: a single-center series of 20 cases

In recent years, Shimane University Hospital has begun to see patients with pelvic inflammatory disease (PID) which has become severe and chronic after insufficient conservative treatment in primary or secondary medical care facilities. Serious chronic tubo-ovarian abscess (TOA) is complicated by intraperitoneal inflammatory adhesions to surrounding organs, so that it is difficult to determine the original anatomical position of organs at surgery. Forcible synechotomy can result in damage to the adhering organs and insufficient drainage after surgery can cause recurrence of inflammation. In order to increase the chances for a successful surgical treatment, careful preparation, such as preoperative administration of antibiotics and ureteral stent insertion are necessary. In addition, the chances for recurrence of inflammation can be lessened by thorough intraperitoneal irrigation and insertion of a drainage tube.

Analysis of regulatory review times of new drugs in Japan: association with characteristics of new drug applications, regulatory agency, and pharmaceutical companies

WHAT IS KNOWN AND OBJECTIVE

Various factors have been reported to be associated with the duration of regulatory review of new drug applications (NDAs). We investigated potential links between the review times in Japan and the attributes of NDAs, the regulatory agency and pharmaceutical companies.

METHODS

We analysed new drugs approved in 2000-2009 in Japan using a proprietary database collected through annual surveys to pharmaceutical companies. Regression models in which individual firms were treated as either a fixed effect or a random effect were applied to examine factors associated with the overall review time and the duration of each step of the review.

RESULTS AND DISCUSSION

The fixed effect model analysis using variations within each firm indicated that new molecular entities that were submitted to the Pharmaceuticals and Medical Devices Agency (PMDA), priority reviews and pre-NDA consultations were associated with a shorter overall review time, whereas additional studies during the review resulted in a longer review. In the random effect model analysis using both within- and between-firm variations, use of end-of-phase 2 consultations and foreign clinical data also had negative coefficients, suggesting the effect of these two vary among firms. Analysis of each step of the review process revealed NDAs reviewed by the Committee on Drugs under the Ministry of Health, Labour and Welfare, and the number of NDAs assigned to a review team were significantly linked with their duration, whereas consultation services and the number of reviewers had no relation.

WHAT IS NEW AND CONCLUSION

Factors associated with each step of the review process as well as the differences in attributes and strategies among pharmaceutical companies should be considered to further improve the speed, quality and efficiency of the regulatory review.