Artificial intelligence-based analysis of payment system data can predict one-year mortality of hospitalized patients with heart failure

Background

Individual risk stratification is fundamental in the care of heart failure (HF) patients. However, the prediction performance of risk scores, such as MAGGIC and SHFM, is not adequate and, more importantly, they need additional predictors including various biomarkers, imaging data, and environmental factors. Data from a case-mix payment system including diagnosis and procedures with outcomes can be used to develop the risk prediction models, allowing the use of big data for a more accurate prediction of mortality.

Purpose

This study aimed to develop artificial intelligence (AI) models for predicting 1-year mortality in patients hospitalized due to HF.

Methods

We analyzed the data from 10175 patients enrolled in the Japanese Registry Of Acute Decompensated Heart Failure (JROADHF). Candidate variables included the data obtained from a payment system introduced by the Japanese government, the Diagnosis Procedure Combination (DPC), which included each patient profile (age, sex, height, weight), principal diagnosis for hospitalization, comorbidities, procedures, length of hospital stay, and discharge status. They did not include clinical data available from patients such as vital status, laboratory data including bio-makers, electrocardiographic and echocardiographic data. The collected data were divided into the training set and the validation set (80%: 20%). With the training set, 5 AI models (logistic regression, random forest, support vector machine, neural network, and ensemble classifier) learned the one-year mortality results. AI models were evaluated by using the validation set with ROC analysis. The training and validation steps were repeated 10 times with different seed values to calculate the C-statistic of each model. We also identified the predictors for one-year prognosis acquired from the AI models.

Results

At 1-year of follow-up, a total of 1727 patients had died (17%). Among the machine learning models, the ensemble classifier showed the highest C-statistic of 0.76 (95% confidence interval: 0.75 to 0.77) for predicting mortality. Top predictors acquired from the random forest classifier was ADL (Barthel Index) at discharge, age, body mass index, and length of hospital stay.

Conclusion

By using AI-based analysis of a national case-mix payment system data, the present risk stratification model could predict the one-year mortality of hospitalized HF patients without any quantitative laboratory and physiological data. Furthermore, the present results could emphasize the advantage of this approach using the claim-based data that are routinely collected in a usual daily practice with no need to collect any additional information.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Japan Agency for Medical Research and Development

Beta-blocker use is associated with prevention of left ventricular remodeling in recovered dilated cardiomyopathy

Background

Withdrawal of optimal medical therapy has been reported to relapse cardiac dysfunction in patients with dilated cardiomyopathy (DCM) whose cardiac function had improved. However, it is unknown whether beta-blockers can prevent deterioration of cardiac function in those patients.

Purpose

We examined the effect of beta-blockers on left ventricular ejection fraction (LVEF) in recovered DCM.

Methods

We analyzed the clinical personal records of DCM, a national database of Japanese Ministry of Health, Labor and Welfare, between 2003 and 2014. Recovered DCM was defined as a previously documented LVEF <40% and a current LVEF ≥40%. Patients with recovered DCM were divided into two groups according to the use of beta-blockers. The primary outcome was defined as a decrease in LVEF >10% at two years of follow-up. A one to one propensity case-matched analysis was used. A per-protocol analysis was also performed. Considering intra- and inter-observer variability of echocardiographic evaluations, we also examined outcomes by multivariable logistic regression model after changing the inclusion criteria as follows; (1) previous LVEF <40% and current LVEF ≥40%; (2) previous LVEF <35% and current LVEF ≥40%; (3) previous LVEF <30% and current LVEF ≥40%; (4) previous LVEF <40% and current LVEF ≥50%. Outcomes were also changed as (1) decrease in LVEF ≥5% (2) decrease in LVEF ≥10% (3) decrease in LVEF ≥15%. The analysis of outcomes by using combination of multiple imputation and inverse probability of treatment weighting was also conducted to assess the effects of missing data and selection bias attributable to propensity score matching on outcomes.

Results

From 2003 to 2014, 40,794 consecutive patients with DCM were screened. Out of 5,338 eligible patients, 4,078 received beta-blockers. Propensity score matching yielded 998 pairs. Mean age was 61.7 years and 1,497 (75.0%) was male. Mean LVEF was 49.1±8.1%. The primary outcome was observed less frequently in beta-blocker group than in no beta-blocker group (18.0% vs. 23.5%; odds ratio [OR] 0.72; 95% confidence interval [CI] 0.58–0.89; P=0.003). The prevalence of increases in LVDd (11.5% vs. 15.8%; OR 0.70; 95% CI 0.54–0.91; P=0.007) and LVDs (23.1% vs. 27.2%; OR 0.80; 95% CI 0.65–0.99; P=0.041) was also lower in the beta-blocker group. Similar results were obtained in per-protocol analysis. These results were robust to several sensitivity analyses. As a result of preventing a decrease in LVEF, the deterioration to HFrEF was also prevented by the use of beta-blocker (23.6% vs. 30.6%). Subgroup analysis demonstrated that beta-blocker prevented decrease in LVEF regardless of atrial fibrillation.

Conclusion

Use of beta-blocker was associated with prevention of decrease in left ventricular ejection fraction in patients with recovered DCM.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Health Sciences Research Grants from the Japanese Ministry of Health, Labour and Welfare (Comprehensive Research on Cardiovascular Diseases)

Convexity Subarachnoid Hemorrhage Accompanied by Hyperacute Ischemic Stroke

INTRODUCTION AND OBJECTIVES

The clinical characteristics of convexity subarachnoid hemorrhage (cSAH) accompanying hyperacute ischemic stroke are unknown. We aimed to investigate the incidence and clinical characteristics of cSAH with hyperacute ischemic stroke.

METHODS

Participants comprised symptomatic ischemic stroke patients with ≤4.5 h from onset to door who also underwent initial MRI ≤4.5 h from onset. We reviewed initial and follow-up MRI during admission to identify cSAH. Retrospective reviews of cSAH incidence and clinical characteristics were performed.

RESULTS

We screened 1,249 consecutive symptomatic ischemic stroke patients, including 384 patients (279 males [73%]; median age, 67 years). Of the 384 patients, arterial ischemic stroke was seen in 382 patients, and venous ischemic stroke in 2 patients. Of the hyperacute arterial ischemic stroke, cSAH was identified within 4.5 h of ischemic stroke onset in 2 patients (0.5%) and around 6 days from ischemic stroke onset in 2 patients (0.5%). Of the hyperacute venous ischemic stroke, cSAH was observed in 1 patient on initial MRI. Comparing the clinical characteristics of hyperacute arterial ischemic stroke with and without cSAH, patients with cSAH were more likely to have arterial stenosis or occlusion ipsilateral to the cSAH (100 vs. 47%, p = 0.048), and the ischemic lesion only in the right hemisphere (100 vs. 33%, p = 0.013). In all cases, outcomes were favorable (modified Rankin Scale 0-1 at 3 months from onset).

CONCLUSIONS

Convexity SAH was observed in 0.5% of hyperacute ischemic patients within 4.5 h of ischemic stroke onset and in 0.5% around 6 days from ischemic stroke onset.

A pediatric case of central skull base osteomyelitis caused by Streptococcus milleri group infection and mimicking malignancy

Central skull base osteomyelitis (CSBO) that has expanded to the middle cranial fossa is a rare complication of nasopharyngeal infection in children. Diagnosing CSBO is challenging in children, because specific symptoms are lacking and imaging findings can mimic skull base malignancy. We report on a 3-year-old girl who complained of pyrexia, headache, and vomiting and in whom a mass around the clivus was detected with magnetic resonance imaging. The patient received a diagnosis of CSBO based on characteristic imaging findings and the detection of a Streptococcus milleri group (SMG) in blood cultures. Clinical symptoms and abnormal imaging findings, including a mass lesion, were improved by prompt antibiotic treatment. The present patient had paranasal sinusitis with bacteremia of SMG, leading to the speculation of hematogeneous dissemination of SMG from the paranasal sinus. Awareness of CSBO, its early diagnosis, and aggressive management are required because CSBO is associated with high morbidity due to a life-threating infection involving multiple cranial nerves.

The Impact of Cerebral Microbleeds Presence on Outcome Following Minor Stroke Treated With Antiplatelet Therapy

Background and Purpose: The relationship between cerebral microbleeds (CMBs) and prognosis in patients with ischemic stroke is still unclear. Our aim here was to verify the relationship between CMBs and functional outcomes in patients with minor ischemic stroke treated with antiplatelet therapy.

Methods: We retrospectively reviewed consecutive patients with a non-cardiogenic minor ischemic stroke (NIHSS <4 on admission) who underwent initial brain magnetic resonance imaging within the first 48 h following symptom onset. The patients were divided into two groups based on the presence or absence of CMBs and the two groups were adjusted using the pre-stroke modified Rankin scale (mRS). Poor outcome was defined as an mRS score in the 3–6 range measured 90 days after symptom onset. Logistic regression analyses were performed to determine the factors independently associated with poor outcome.

Results: A total of 240 patients (187 men, median age 66 years old) were enrolled in our study. There was a non-significant trend toward a worsening shift of 3-month mRS score distribution in the CMB group compared with the no-CMB group. Multivariate analysis revealed that the presence of CMBs was independently predictive of poor outcome (OR, 3.44; 95% CI, 1.08–10.93; P = 0.036).

Conclusion: Our findings suggest that the presence of CMBs is the predicting factor of poor outcome in minor ischemic stroke patients.

Differentiating between glioblastomas with and without isocitrate dehydrogenase gene mutation by findings on conventional magnetic resonance images

Various studies using advanced techniques have estimated the isocitrate dehydrogenase (IDH) gene mutation status in glioblastoma (GBM) from preoperative images. However, it is important to be able to predict mutation status using conventional MRI, which is more widely used in clinical practice. In this study, we examined the features of GBM with and without IDH gene mutation on conventional MRI. Twenty-three patients with GBM in whom IDH gene mutation status had been pathologically and molecularly confirmed in tumor specimens were included. The cases were divided into an IDH-wildtype group (n = 17) and an IDH-mutant group (n = 6). We retrospectively compared the following imaging parameters between the two groups: tumor location (superficial or deep), borders on T2-weighted images (regular or irregular), borders of enhancing lesions (regular or irregular), number of lesions showing contrast enhancement (solitary or multiple), presence or absence of intralesional bleeding, and presence or absence of a low-grade glioma in the background around the enhancing lesion. IDH-wildtype tumors were significantly more likely to be superficial than were IDH-mutant tumors (p < 0.05). Enhancing lesions in the IDH-wildtype group were less likely to have an irregular border (p = 0.059). Low-grade glioma was a background lesion in 5 patients (83.3%) in the IDH-mutant group and 9 (52.9%) in the IDH-wildtype group. The IDH mutation status is likely to be wildtype in patients with superficial GBM in which the enhancing lesion has a regular border and when low-grade glioma is not found as a background lesion on MRI.

MR imaging of palatine gland lesion-associated IgG4-related disease: a preliminary study

PURPOSE

The purpose of this study was to present the novel MRI findings of palatine gland lesion-associated IgG4-related disease (PGL-IgG4-RD) and to compare the imaging features with those in normal individuals.

MATERIALS AND METHODS

We retrospectively evaluated the MRI scans of 12 patients with PGL-IgG4-RD and 12 control individuals. We measured the thickness of the palatal regions and calculated the T2-weighted signal intensity ratio of palatal regions to cerebral white matter (HWR) and compared them between the PGL-IgG4-RD and control groups.

RESULTS

In univariate analysis, the HWR of the palatal regions on T2-weighted imaging was smaller in the PGL-IgG4-RD group than in the control group (average = 1.2 vs. 1.9, p < 0.001). The palate thickness in patients with PGL-IgG4-RD was significantly greater than that in controls (average = 12 vs 6 mm, p < 0.001). The cut-off value of the between-group palate thickness on coronal MRI was 8 mm.

CONCLUSION

The thickening of the palatal regions seen with low signal intensity on T2-weighted imaging may be a characteristic imaging feature of PGL-IgG4-RD. Such findings will be useful for the timely diagnosis and subsequent treatment planning of IgG4-RDHP.

P6283Downregulation of Tim44 exacerbates oxidative stress-induced ROS production and cardiomyocytes death by reducing mitochondrial SOD2

Background

Mitochondrial dysfunction has been highlighted as a critical driver of cardiac remodeling and failure. Mitochondria contains about 1500 proteins, 99% of which are encoded in the nuclear genome. Therefore, protein import into mitochondria is essential to maintain mitochondrial function. Previous reports suggest that nuclear-encoded mitochondrial precursor proteins import into mitochondria by multiple complex; translocase of outer membrane (TOM), translocase of inner membrane (TIM), and protein associated motor (PAM). However, the role of these protein import machineries of mitochondria in cardiac remodeling remains to be elucidated.

Objective

The purpose of this study was to elucidate the role of TOM, TIM, and PAM complex in cardiac remodeling and cardiomyocyte death.

Methods and results

C57BL/6J mice were subjected to myocardial infarction (MI) by permanent ligation of left anterior descending artery. Four weeks after operation, MI-mice demonstrated left ventricular (LV) dilation (LV end-diastolic dimension: 3.91 vs. 5.54 mm, n=8–11, p<0.05) and dysfunction (LV fractional shortening: 33.3 vs. 7.7%, n=8–11, p<0.05). Tim44 protein levels, a component of PAM complex, in mitochondrial fraction from non-infarcted left ventricle were significantly decreased compared with those in the heart from sham-operated mice by 39% (p<0.05), whereas other proteins related to TOM, TIM and PAM complex such as Tom20, Tom22, Tom40, Tom70, Tim22, Tim23 and mtHSP70 were not altered between MI-mice and sham-mice. In addition, blue-native polyacrylamide gel electrophoresis revealed that a protein complex associated to Tim44 was significantly decreased in non-infarcted LV by 40% (p<0.05). Superoxide dismutase 2 (SOD2), a mitochondrial matrix protein, was decreased in mitochondrial fraction from non-infarcted LV by 20% (p<0.05), accompanied by enhancing protein carbonylation, a marker of oxidative stress, by 40% (p<0.05). To assess the role of Tim44, it was downregulated by small interfering RNA in cultured neonatal rat ventricular myocytes (NRVMs). Knockdown of Tim44 significantly decreased SOD2 protein levels in mitochondrial fractionation (22%, p<0.05), with no significant changes in its mRNA levels. Furthermore, knockdown of Tim44 significantly increased protein carbonylation (20%, p<0.05) and cleaved caspase 3 (47%, p<0.05) and decreased cell viability (69%, p<0.05), assessed by cell titer assay, in H2O2-treatred NRVMs.

Conclusions

Downregulation of Tim44 exacerbates oxidative stress-induced ROS production and cardiomyocytes death, which is associated with a decrease in mitochondrial SOD2. Endogenous Tim44 might play a protective role in cardiac remodeling by attenuating oxidative stress and cardiomyocyte death via SOD2 import into mitochondria.

P1606Glutamine-fructose-6-phosphate amidotransferase 2 mediates isoproterenol-induced cardiac hypertrophy by increasing Akt O-GlcNAcylation through hexosamine biosynthesis pathway

Background

Cardiac hypertrophy is an independent risk factor for heart failure and cardiac death. Hexosamine biosynthesis pathway (HBP), an accessory pathways of glycolysis, is known to be involved in the attachment of O-linked N-acetylglucosamine motif (O-GlcNAcylation) to proteins, a post-translational modification. However, the role of HBP has not been determined in pathological cardiac hypertrophy.

Purpose

The purpose of this study to examine whether glutamine-fructose-6-phosphate amidotransferase 2 (GFAT2), a critical enzyme of HBP, mediates cardiac hypertrophy by protein O-GlcNAcylation and activating hypertrophic signaling in cardiomyocytes.

Methods and results

C57BL/6J mice were treated with isoproterenol (ISO: 15 mg/kg/day, 1 week) with or without 6-Diazo-5-oxo-L-norleucine (DON, an inhibitor of GFAT: 500 μg/kg/day, 1week). ISO-treated mice (ISO+vehicle) showed cardiac hypertrophy, which were attenuated in ISO and DON-treated mice (ISO+DON) (heart weight to tibial length ratio: 7.70±0.09 vs. 7.11±0.15 mg/mm, n=12, p<0.05, left ventricular wall thickness: 1.05±0.02 vs. 0.86±0.03 mm, n=6, p<0.05). Cardiomyocyte cross-sectional area was also decreased in ISO+DON compared with ISO+vehicle (309±25 vs. 252±13 mm2, n=,3 p<0.05). Whereas expression levels of GFAT2 and protein O-GlcNAcylation in the heart were increased in ISO+vehicle compared with control+vehicle by 3.3 and 1.5 folds, respectively (n=9 and n=9, p<0.05), expression levels of O-GlcNAc transferase (OGT) and the β-N-acetylglucosaminidase (OGA), other enzymes regulating O-GlcNAcylation, were not altered in both groups, indicating that ISO activated HBP by GFAT2. Protein O-GlcNAcylation in ISO+DON was lower than that in ISO+vehicle by 83% (n=9, p<0.05). In addition, phosphorylation of Akt, a critical mediator of cardiac hypertrophy, but not other mediators of cardiac hypertrophy such as ERK, JNK, or p38MAPK, was significantly decreased in ISO+DON by 76% (n=9, p<0.05). In cultured neonatal rat ventricular myocytes, treatment with ISO (1μM, 12h) increased the expression levels of GFAT2 and protein O-GlcNAcylation by 1.3 and 1.5 folds, respectively (n=6 and n=6, p<0.05), but not GFAT1. Furthermore, ISO stimulation increased a direct O-GlcNAcylation of Akt by 1.4 folds (n=3, p<0.05). Downregulation of GFAT2 by RNA silencing decreased cell size by 82% (n=6, p<0.05) and protein O-GlcNAcylation and phosphorylation of Akt by 76% and 54%, respectively (n=9 and n=9, p<0.05) in cardiomyocyte treated with ISO. Conversely, administration of glucosamine, a substrate of HBP, increased protein of O-GlcNAcylation and phosphorylation of Akt by 1.3 and 1.8 folds, respectively (n=6 and n=6, p<0.05).

Conclusions

GFAT2, a limiting enzyme of HBP, mediates pathological cardiac hypertrophy by Akt activation probably due to its O-GlcNAcylation. GFAT2-O-GlcNAcylation-Akt pathway might be a potential novel therapeutic target for cardiac hypertrophy.

P6305Activation of invariant natural killer T cells ameliorates doxorubicin-induced cardiomyopathy

Background

Invariant natural killer T (iNKT) cells orchestrate tissue inflammation via regulating various cytokine productions, especially strongly upregulating interferon (IFN)-γ. Activation of iNKT cells have been previously reported to exert protective effects against post-infarcted cardiac remodeling and cardiac ischemia/reperfusion injury. However, the role of iNKT cells has not been determined in doxorubicin (DOX)-induced cardiomyopathy.

Purpose

The purpose of this study was to examine whether the activation of iNKT cells by α-galactosylceramide (αGC), which specifically activates iNKT cells, could affect DOX-induced cardiomyopathy, and if so, to elucidate its downstream target.

Methods

C57BL/6J mice were received the intraperitoneal injection of either αGC (0.1μg/g, n=11) or vehicle (n=13). After 1 week, these mice were treated with a low dose of DOX (18mg/kg via intravenous 3 injections over 1 week), and were followed during 14 days.

Results

DOX mice (DOX+vehicle) showed left ventricular (LV) dysfunction and dilatation, which were significantly ameliorated in DOX mice receiving αGC (DOX+αGC) (LV fractional shortening: 27.4±4.31 vs. 31.5±4.62%, p<0.05, LV end-diastolic diameter: 3.70±0.16 vs. 3.32±0.23mm, p<0.05), with no significant changes in arterial pressure, body weight, and food consumption, 14 days after DOX injection. DOX+vehicle demonstrated a significant decrease in myocardial gene expression of Vα14Jα18, a specific marker of iNKT cells, and IFN-γ compared with control mice. Vα14Jα18 expression levels were higher in DOX+αGC than DOX+vehicle by 9.2 folds (p<0.05). Consistent with this change, IFN-γ was higher in DOX+αGC than DOX+vehicle by 4.4 folds (p<0.05), whereas interleukin (IL)-1, IL-4, IL-6, IL-10, IL-17, IL-23, and tumor necrosis factor (TNF)-α were not altered in both groups. Phosphorylation of Akt, its active form, in the heart was significantly increased in DOX+αGC compared with DOX+vehicle by 1.8 folds (p<0.05).

Conclusions

Activation of iNKT cells by αGC play a protective role against DOX-induced cardiac dysfunction, which was associated with enhancing expression of IFN-γ and activating Akt. Therapies designed to activate iNKT cells might be beneficial to protect the heart from DOX injury.

MRI of skeletal muscles in patients with idiopathic inflammatory myopathies: characteristic findings and diagnostic performance in dermatomyositis

Objective

To define the characteristic findings on MRI of skeletal muscles in patients with dermatomyositis (DM) relative to those in patients with other idiopathic inflammatory myopathies (IIMs) and to assess their diagnostic performance in DM.

Methods

Thirty-six patients with DM, 17 patients with amyopathic DM, 19 patients with polymyositis and 16 patients with non-IIM classified by the 2017 European League Against Rheumatism/American College of Rheumatology criteria were included in this study. The following MRI findings (short-tau inversion recovery [STIR] and gadolinium-enhanced fat-suppressed T1-weighted imaging [Gd-T1WI]) for proximal limb muscles were compared between the disease groups and between myositis-specific autoantibodies/myositis-associated autoantibodies (MSAs/MAAs)-positive and MSAs/MAAs-negative groups: structures with high signal intensity (HSI) (subcutaneous, fascia, muscle); distributions of HSI areas in muscle (diffuse, patchy, peripheral) and patterns of HSI in muscle (honeycomb, foggy, strong HSI). Univariate, multivariate and receiver-operating characteristic [ROC] analyses were performed to assess the diagnostic performance of MRI in DM.

Results

The characteristic MRI findings in patients with DM were subcutaneous HSI, fascial HSI, peripheral distribution and honeycomb pattern. The MRI findings in the MSAs/MAAs-positive group included more frequent fascial HSI but less frequent foggy pattern compared with the MSAs/MAAs-negative group. Likelihood of DM score ≥ 3 (obtained by counting the number of characteristic MRI findings in patients with DM) showed good diagnostic performance in DM (STIR: sensitivity 72.2%, specificity 88.5%, area under ROC curve [AUC] 84.9%; Gd-T1WI: sensitivity 81.2%, specificity 91.5%, AUC 89.9%).

Conclusion

The characteristic MRI findings of skeletal muscles can predict patients with DM as well as patients with MSAs/MAAs.

BRAF V600E-mutated diffuse glioma in an adult patient: a case report and review

Recent advances in genomic technology and genome-wide analysis have identified key molecular alterations that are relevant to the diagnosis and prognosis of brain tumors. Molecular information such as mutations in isocitrate dehydrogenase (IDH) genes or 1p/19q co-deletion status will be more actively incorporated into the histological classification of diffuse gliomas. BRAF V600E mutations are found frequently in circumscribed low-grade gliomas such as pleomorphic xanthoastrocytoma (PXA) and extra-cerebellar pilocytic astrocytoma, or epithelioid glioblastomas (E-GBM), a rare variant of GBM. This mutation is relatively rare in other types of diffuse gliomas, especially in adult onset cases. Here, we present an adult onset case of IDH wild-type/BRAF V600E-mutated diffuse glioma, evolving from grade III to grade IV. The tumor displayed atypical exophytic growth and had unusual histological features not fully compatible with, but indicative of PXA and E-GBM. We discuss differential diagnosis of the tumor, and review previously described diffuse gliomas with the BRAF V600E mutation.

Olfactory function combined with morphology distinguishes Parkinson's disease

OBJECTIVE

This study aimed to examine whether the volume of the olfactory bulbs and tracts (OB & T) on magnetic resonance imaging (MRI) is useful for differentiating Parkinson's disease (PD) from PD-related disorders.

METHODS

The study group comprised 13 patients with PD, 11 with multiple system atrophy (MSA), five with progressive supranuclear palsy, and five with corticobasal degeneration (PSP/CBD). All patients were evaluated using the odor stick identification test for Japanese (OSIT-J), (123)I-meta-iodobenzylguanidine (MIBG) scintigraphy, and brain MRI. OB & T areas on 1-mm-thick coronal images were measured and summed for volumes. We examined relationships between olfactory function and volume, and cardiovascular dysautonomia. We defined the cut-off values for OSIT-J score or MIBG uptake and OB & T volume to discriminate PD from PD-related disorders and calculated the proportional rate of PD in four categorized groups.

RESULTS

OB & T volume was smaller in PD than in MSA or PSP/CBD (p < 0.05 each). The cut-off for detecting PD patients was OSIT-J score <8, heart/mediastinum ratio <1.6, and OB & T volume <270 mm(3). In the group with OSIT-J score <8 and OB & T volume <270 mm(3), the proportion of PD patients among all patients with PD-related disorders was 91%. The rate of probable PD gradually increased as OSIT-J score and OB & T volume decreased (p < 0.001).

CONCLUSIONS

Although preliminary, these data obtained from a combined morphological and functional evaluation of OB or cardiovascular dysautonomia could be useful for further differential of PD and other PD-related disorders.

In vivo SPECT imaging of amyloid-β deposition with radioiodinated imidazo[1,2-a]pyridine derivative DRM106 in a mouse model of Alzheimer's disease

Noninvasive determination of amyloid-β peptide (Aβ) deposition has important significance for early diagnosis and medical intervention for Alzheimer's disease (AD). In the present study, we investigated the availability of radiolabeled DRM106 ((123/125)I-DRM106 [6-iodo-2-[4-(1H-3-pyrazolyl)phenyl]imidazo[1,2-a]pyridine]), a compound with sufficient affinity for the synthesis of human Aβ fibrils and satisfactory metabolic stability, as a SPECT ligand in living brains.

METHOD

The sensitivity of (125)I-DRM106 for detecting Aβ deposition was compared with that of (125)I-IMPY (2-(4'-dimethylaminophenyl)-6-iodo-imidazo[1,2-a]pyridine), a well-known amyloid SPECT ligand, by ex vivo autoradiographic analyses in 18-mo-old amyloid precursor protein transgenic mice. To verify the sensitivity and quantitation of radiolabeled DRM106 for in vivo imaging, we compared the detectability of Aβ plaques with (123)I-DRM106 and a well-known amyloid PET agent, (11)C-labeled Pittsburgh compound B ((11)C-PiB), in 29-mo-old transgenic mice and age-matched nontransgenic littermates. Additionally, we compared the binding characteristics of (125)I-DRM106 with those of (11)C-PiB and (11)C-PBB3, which selectively bind to Aβ plaques and preferentially to tau aggregates, respectively, in postmortem AD brain sections.

RESULTS

Ex vivo autoradiographic analysis showed that measurement with (125)I-DRM106 has a higher sensitivity for detecting Aβ accumulation than with (125)I-IMPY in transgenic mice. SPECT imaging with (123)I-DRM106 also successfully detected Aβ deposition in living aged transgenic mice and showed strong correlation (R = 0.95, P < 0.01) in quantitative analysis for Aβ plaque detection by PET imaging with (11)C-PiB, implying that sensitivity and quantitation of SPECT imaging with (123)I-DRM106 are almost as good as (11)C-PiB PET for the detectability of Aβ deposition. Further, the addition of nonradiolabeled DRM106 fully blocked the binding of (125)I-DRM106 and (11)C-PiB, but not (11)C-PBB3, to AD brain sections, and (125)I-DRM106 showed a lower binding ratio of the diffuse plaque-rich lateral temporal cortex to the dense-cored/neuritic plaque-rich hippocampal CA1 area, compared with (11)C-PiB.

CONCLUSION

All of these data demonstrated the high potential of (123)I-DRM106 for amyloid imaging in preclinical and clinical application, and it might more preferentially detect dense-cored/neuritic amyloid deposition, which is expected to be closely associated with neuropathologic changes of AD.

Angiotensin II type 1 receptor blockers suppress neointimal hyperplasia after stent implantation in carotid arteries of hypercholesterolemic rabbits

OBJECTIVES

The purpose of this study was to examine whether oral administration of an angiotensin II type 1 receptor blocker (ARB) inhibited in-stent neointimal hyperplasia in carotid arteries of hypercholesterolemic rabbits.

METHODS

Eleven male New Zealand white rabbits were subjected to endothelial injuries of the right common carotid arteries using a balloon catheter and then received chow containing 1% cholesterol for 6 weeks. A balloon-expandable stainless steel stent was subsequently inserted at the injured sites of the arteries. After stenting, five rabbits were randomly treated with an oral ARB, candesartan cilexetil (5 mg/kg per day orally), while the remaining six rabbits acted as untreated controls. Four weeks after the implantation, the rabbits were killed, followed by collection of the arteries including the stents. After careful removal of the stents, tissue sections were prepared and analyzed by morphometric and immunohistochemical methods.

RESULTS

The mean thickness of the neointima was 53.6 ± 17.0 μm in the ARB-treated group, which was significantly reduced compared to 95.9 ± 16.7 μm in the control group (P = 0.0012). Immunohistochemistry showed a decrease in accumulation of macrophages and tenascin-C expression in the arterial wall in the ARB-treated animals.

DISCUSSION

This study suggested that systemic administration of an ARB suppressed neointimal hyperplasia in the carotid artery following stent implantation by the anti-inflammatory effects, although the animal cohort tested was rather small. This finding implies that ARBs may be useful and practical agents for protection against in-stent restenosis in humans, and warrants further basic and clinical studies.