Regional Inequalities in Oral Frailty and Social Capital

INTRODUCTION

Oral frailty leads to poor nutritional status, which, in turn, leads to frailty. This cross-sectional study aimed to determine regional differences in the prevalence of oral frailty and to identify factors associated with oral frailty using 3-level multilevel models.

METHODS

This study comprised 165,164 participants aged ≥65 y without long-term care requirements in the Japan Gerontological Evaluation Study. The dependent variable was oral frailty, which was calculated based on age, number of teeth, difficulty in eating tough foods, and choking. The individual-level independent variables included sociodemographics, present illness, social participation, frequency of meeting friends, and social capital. The local district-level independent variable was social capital (n = 1,008) derived from exploratory factor analyses. The municipality-level independent variable was population density (n = 62). Three-level multilevel Poisson regression analysis was performed to calculate the prevalence ratios (PRs).

RESULTS

The prevalence of oral frailty in municipalities ranged from 39.9% to 77.6%. Regarding district-level factors, higher civic participation was significantly associated with a lower probability of oral frailty. At the municipality level, the PR of the rural-agricultural area was 1.17 (95% confidence interval, 1.11-1.23) (reference: metropolitan).

CONCLUSION

These results highlight the usefulness of oral frailty prevention measures in encouraging social participation in rural areas.

KNOWLEDGE TRANSFER STATEMENT

The results of the present study showed regional differences in oral frailty. In particular, rural-agricultural areas show higher prevalence rates of oral frailty than those in metropolitan cities. Promoting measures of social participation among older adults may help prevent oral frailty in rural areas.

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.

Natural history of severe aortic stenosis in elderly heart failure patients who declined transcatheter aortic valve implantation

Background

Transcatheter aortic valve implantation (TAVI) is an established minimally invasive treatment for elderly patients with severe aortic stenosis (AS). Although it is a relatively minimally invasive procedure, many elderly patients cannot undergo TAVI due to advanced age, advanced dementia, significantly impaired ADL, or because the patient or family does not wish to undergo TAVI. In general, severe AS patients died 5 years after an angina attack, 3 years after syncope symptoms, and 2 years after heart failure symptoms. However, few studies have investigated the prognosis of elderly patients with severe AS who declined TAVI.

Purpose

This study aimed to comprehend the natural history of elderly severe AS patients who declined aortic valve intervention and identify risk factors for death in the TAVI era.

Methods

We retrospectively reviewed 2,786 echocardiographic data from our hospital between 2017 and 2021. We identified 504 patients with AS in the echocardiography database. The severe AS was defined by the following echocardiography parameters: peak aortic flow velocity ≥4.0 m/s, aortic valve mean gradient ≥40 mmHg, aortic valve area (AVA)<1.0 cm2, or AVA index<0.6 cm2/m2. Patients with mild and moderate AS and patients who underwent surgical or transcatheter aortic valve intervention were excluded. Eventually, 82 patients fulfilled the study criteria and were analyzed in this study. Clinical events were investigated, and Cox proportional hazards analysis was performed to elucidate risk factors for mortality.

Results

The mean age was 89±6 years, and 63 (77%) were women. AHA/ACC classification was Stage A/B/C/D: 0%/52.4%/39.0%/8.5%. As event occurrence, we detected 34 (41.5%) all-cause deaths, 41 (50.0%) major adverse cardiovascular events, 32 (39.0%) development of heart failure, 13 (15.9%) chest pain attacks, and 3 (3.7%) syncope. The time from diagnosis of severe AS to all-cause death was 227±273 days, and the 1-, 2-, and 3-year survival rates were 61.5%, 46.2%, and 36.9%, respectively. Of the heart failure-onset population, 16 (50.0%) were found to have severe AS on initial heart failure admission. The incidence of heart failure at 1, 2, and 3 years after diagnosis of severe AS was 60.1%, 56.7%, and 45.4%, respectively. The time from heart failure to death was 107±147 days. Cox proportional hazards analysis adjusted with age, sex, comorbidities revealed that dementia (HR 4.5, P=0.014) and Katz index <5 (HR7.8, P=0.009) were independent risk factors for mortality.

Conclusions

Compared to the comprehension of the natural history of AS patients, the prognosis in severe AS patients who declined TAVI was extremely poor. Although the elderly patients did not have a high rate of angina attacks or syncope symptoms, probably due to their reduced ADL, the results suggest that dementia prevention and maintenance of exercise tolerance are essential since dementia and reduced ADL (Katz<5) are independent risk factors for mortality.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Clinical Research Promotion Foundation Reiwa 2 Michinari Hieda

The RNA-binding protein Puf5 and the HMGB protein Ixr1 contribute to cell cycle progression through the regulation of cell cycle-specific expression of CLB1 in Saccharomyces cerevisiae

Puf5, a Puf-family RNA-binding protein, binds to 3´ untranslated region of target mRNAs and negatively regulates their expression in Saccharomyces cerevisiae. The puf5Δ mutant shows pleiotropic phenotypes including a weakened cell wall, a temperature-sensitive growth, and a shorter lifespan. To further analyze a role of Puf5 in cell growth, we searched for a multicopy suppressor of the temperature-sensitive growth of the puf5Δ mutant in this study. We found that overexpression of CLB2 encoding B-type cyclin suppressed the temperature-sensitive growth of the puf5Δ mutant. The puf5Δ clb2Δ double mutant displayed a severe growth defect, suggesting that Puf5 positively regulates the expression of a redundant factor with Clb2 in cell cycle progression. We found that expression of CLB1 encoding a redundant B-type cyclin was decreased in the puf5Δ mutant, and that this decrease of the CLB1 expression contributed to the growth defect of the puf5Δ clb2Δ double mutant. Since Puf5 is a negative regulator of the gene expression, we hypothesized that Puf5 negatively regulates the expression of a factor that represses CLB1 expression. We found such a repressor, Ixr1, which is an HMGB (High Mobility Group box B) protein. Deletion of IXR1 restored the decreased expression of CLB1 caused by the puf5Δ mutation and suppressed the growth defect of the puf5Δ clb2Δ double mutant. The expression of IXR1 was negatively regulated by Puf5 in an IXR1 3´ UTR-dependent manner. Our results suggest that IXR1 mRNA is a physiologically important target of Puf5, and that Puf5 and Ixr1 contribute to the cell cycle progression through the regulation of the cell cycle-specific expression of CLB1.

Gli1+-PDL Cells Contribute to Alveolar Bone Homeostasis and Regeneration

The periodontal ligament (PDL) contains mesenchymal stem cells (MSCs) that can differentiate into osteoblasts, cementoblasts, and fibroblasts. Nevertheless, the distribution and characteristics of these cells remain uncertain. Gli1, an essential hedgehog signaling transcription factor, functions in undifferentiated cells during embryogenesis. Therefore, in the present study, the differentiation ability of Gli1⁺ cells was examined using Gli1-CreERT2/ROSA26-loxP-stop-loxP-tdTomato (iGli1/Tomato) mice. In 4-wk-old iGli1/Tomato mice, Gli1/Tomato⁺ cells were only slightly detected in the PDL, around endomucin-expressing blood vessels. These cells had proliferated over time, localizing in the PDL as well as on the bone and cementum surfaces at day 28. However, in 8-wk-old iGli1/Tomato mice, Gli1/Tomato⁺ cells were quiescent, as most cells were not immunoreactive for Ki-67. These cells in 8-wk-old mice exhibited high colony-forming unit fibroblast activity and were capable of osteogenic, chondrogenic, and adipogenic differentiation in vitro. In addition, after transplantation of teeth of iGli1/Tomato mice into the hypodermis of wild-type mice, Tomato fluorescence indicating the progeny of Gli1⁺ cells was detected in the osteoblasts and osteocytes of the regenerated bone. These results demonstrate that Gli1⁺ cells in the PDL were MSCs and could contribute to the alveolar bone regeneration.

Pan2-Pan3 complex, together with Ccr4-Not complex, has a role in the cell growth on non-fermentable carbon sources

There are two major deadenylase complexes, Ccr4-Not and Pan2-Pan3, which shorten the 3' poly(A) tail of mRNA and are conserved from yeast to human. We have previously shown that the Ccr4-mediated deadenylation plays the important role in gene expression regulation in the yeast stationary phase cell. In order to further understand the role of deadenylases in different growth condition, in this study we investigated the effect of deletion of both deadenylases on the cell in non-fermentable carbon containing media. We found that both ccr4Δ and ccr4Δ pan2Δ mutants showed similar growth defect in YPD media: when switched to media containing non-fermentable source (Glycerol-Lactate) only the ccr4Δ grew while the ccr4Δ pan2Δ did not. Ccr4, Pan2, and Pan3 were phosphorylated in GlyLac medium, suggesting that the activities of Ccr4, Pan2, and Pan3 may be regulated by phosphorylation in response to change of carbon sources. To get insights how Ccr4 and Pan2 function in the cell growth in media containing non-fermentable source only, we isolated multicopy suppressors for the growth defect on YPGlyLac media of the ccr4Δ pan2Δ mutant and identified two genes, STM1 and REX2, which encode a ribosome-associated protein and a 3'-5' RNA exonuclease, respectively. Our results suggest that the Pan2-Pan3 complex, together with the Ccr4-Not complex, has important roles in the growth on non-fermentable carbon sources.

The eIF4E-binding protein Eap1 has similar but independent roles in cell growth and gene expression with the cytoplasmic deadenylase Ccr4

eIF4E-binding proteins (4E-BPs) are translational repressors that compete with eIF4G for binding to eIF4E. Here we investigated the roles of yeast 4E-BPs, Eap1, and Caf20 in cell wall integrity pathway and gene expression. We found that eap1∆ mutation, but not caf20∆ mutation, showed synthetic growth defect with mutation in ROM2 gene encoding Rho1 GEF. The eap1∆ mutation also showed synthetic lethality with mutation in CCR4 gene encoding cytoplasmic deadenylase. Ccr4 functions in the degradation of LRG1 mRNA encoding Rho1 GAP. Eap1-Y109A L114A, which could not bind to eIF4E, did not suppress the synthetic lethality of eap1∆ ccr4∆ mutant, suggesting that 4E-binding of Eap1 is important for its function. We also found that eap1∆ mutant showed the derepression of stress response gene HSP12. 4E-binding of Eap1 was also required for the repression of HSP12 expression. Our results indicate that Eap1 has similar but independent roles in cell growth and gene expression with Ccr4.

Pbp1, the yeast ortholog of human Ataxin-2, functions in the cell growth on non-fermentable carbon sources

Pbp1, the yeast ortholog of human Ataxin-2, was originally isolated as a poly(A) binding protein (Pab1)-binding protein. Pbp1 regulates the Pan2-Pan3 deadenylase complex, thereby modulating the mRNA stability and translation efficiency. However, the physiological significance of Pbp1 remains unclear since a yeast strain harboring PBP1 deletion grows similarly to wild-type strain on normal glucose-containing medium. In this study, we found that Pbp1 has a role in cell growth on the medium containing non-fermentable carbon sources. While the pbp1Δ mutant showed a similar growth compared to the wild-type cell on a normal glucose-containing medium, the pbp1Δ mutant showed a slower growth on the medium containing glycerol and lactate. Microarray analyses revealed that expressions of the genes involved in gluconeogenesis, such as PCK1 and FBP1, and of the genes involved in mitochondrial function, such as COX10 and COX11, were decreased in the pbp1Δ mutant. Pbp1 regulated the expressions of PCK1 and FBP1 via their promoters, while the expressions of COX10 and COX11 were regulated by Pbp1, not through their promoters. The decreased expressions of COX10 and COX11 in the pbp1Δ mutant were recovered by the loss of Dcp1 decapping enzyme or Xrn1 5’-3’exonuclease. Our results suggest that Pbp1 regulates the expressions of the genes involved in gluconeogenesis and mitochondrial function through multiple mechanisms.

Tropoelastin Expression by Periodontal Fibroblasts

Elastic system fibers are load-bearing proteins found in periodontal tissue. There are three types—oxytalan, elaunin, and elastic fibers—which differ in their relative microfibril and elastin contents. Oxytalan fibers are known to be distributed in the periodontal ligaments and gingiva, whereas elaunin and elastic fibers are present only in the gingiva. We examined gene expression and accumulation of tropoelastin in the cell-matrix layers of human gingival fibroblasts (HGF) and periodontal ligament fibroblasts (HPLF) in vitro. HGF and HPLF were cultured in MEM containing 10% newborn calf serum for 8 wks. Northern blotting and RT-PCR analyses showed that only HGF expressed mRNA encoding tropoelastin. Western blotting analysis demonstrated 77-kDa protropoelastin and 68-kDa tropoelastin only in the cell-matrix layer of HGF cultured for 8 wks. These results suggest that the different tropoelastin expression patterns reflect the difference between HGF and HPLF phenotypes.

Fibrillin-2 Degradation by Matrix Metalloproteinase-2 in Periodontium

Elastic system fibers, comprised of microfibrils and tropoelastin, are extracellular components of periodontal tissue. During development, the microfibrils act as a template on which tropoelastin is deposited. However, the process of elastic system fiber remodeling is not fully understood. Therefore, we examined whether matrix metalloproteinases (MMPs) are involved in the remodeling of fibrillins (major components of microfibrils) by human gingival fibroblasts and periodontal ligament (PDL) fibroblasts. Gingival and PDL fibroblasts were cultured for 6 weeks. In some cultures, MMP inhibitor or tissue inhibitor of matrix metalloproteinsase-2 (TIMP-2) was added to the medium for an additional 2 weeks. Active MMP-2 (62 kDa) appeared as cell-membrane-associated or in extracellular matrix only in PDL fibroblast cell layers. The addition of MMP inhibitor or TIMP-2 significantly increased fibrillin-2 accumulation in PDL fibroblast cell layers, and decreased the amount of fibrillin-2 fragments, suggesting that active MMP-2 may degrade fibrillin-2, and that MMPs may play a role in the remodeling of elastic system fibers in PDL.

Analysis of the Physiological Activities of Scd6 through Its Interaction with Hmt1

Scd6, a yeast homologue of human RAP55, is a component of messenger ribonucleoproteins (mRNPs) that repress translation by binding to translation initiation factors, and also is a decapping activator along with the binding partners Edc3 and Dhh1. Herein, we report that Scd6 is a substrate of the intrinsic protein arginine methyltransferase, Hmt1, in budding yeast Saccharomyces cerevisiae. Mass spectrometric analysis revealed that several arginine residues within the Scd6 RGG motif, which is important for mRNA binding, were methylated in Hmt1 dependent manner. Under stress conditions such as glucose starvation, Scd6 localized to cytoplasmic processing bodies (P-bodies) wherein translationally repressed mRNPs and untranslated mRNAs accumulate. Localization of Scd6 to P-bodies was impaired in hmt1 deletion mutant and in the presence of methylation-deficient substitution of Scd6. In addition, deletion of scd6 and dhh1 led to severe synthetic growth defect at high temperature. Methylation-deficient mutation of Scd6 suppressed the phenotypic defects of scd6 dhh1 double mutant, whereas methylation-mimic mutation did not, suggesting that the arginine methylation might negatively regulate Scd6 function relating to Dhh1. Therefore, the present data suggest that Hmt1-based arginine methylation is required for Scd6 localization and function.

Site-Specific Neutrophil Migration and CXCL2 Expression in Periodontal Tissue

The oral microbial community is the best-characterized bacterial ecosystem in the human host. It has been shown in the mouse that oral commensal bacteria significantly contribute to clinically healthy periodontal homeostasis by influencing the number of neutrophils that migrate from the vasculature to the junctional epithelium. Furthermore, in clinically healthy tissue, the neutrophil response to oral commensal bacteria is associated with the select expression of the neutrophil chemokine CXCL2 but not CXCL1. This preliminary study examined the contribution of commensal bacteria on neutrophil location across the tooth/gingival interface. Tissue sections from the root associated mesial (anterior) of the second molar to the root associated distal (posterior) of the second molar were examined for neutrophils and the expression of the neutrophil chemokine ligands CXCL1 and CXCL2. It was found that both the number of neutrophils as well as the expression of CXCL2 but not CXCL1 was significantly increased in tissue sections close to the interdental region, consistent with the notion of select tissue expression patterns for neutrophil chemokine expression and subsequent neutrophil location. Furthermore, mice gavaged with either oral Streptococcus or Lactobacillus sp. bacteria induced a location pattern of neutrophils and CXCL2 expression similar to the normal oral flora. These data indicate for the first time select neutrophil location and chemokine expression patterns associated with clinically healthy tissue. The results reveal an increased inflammatory load upon approaching the interproximal region, which is consistent with the observation that the interproximal region often reveals early clinical signs of periodontal disease.

Impact of the Oral Commensal Flora on Alveolar Bone Homeostasis

Homeostasis of healthy periodontal tissues is affected by innate and adaptive immunosurveillance mechanisms in response to the normal oral flora. Recent comparisons of germ-free (GF) and normal specific-pathogen-free (SPF) mice have revealed the impact of host immunosurveillance mechanisms in response to the normal oral flora on alveolar bone height. Prior reports that alveolar bone height is significantly less in normal SPF mice compared with their age- and strain-matched GF counterparts suggest that naturally occurring alveolar bone loss is a normal component of healthy periodontal tissue homeostasis. In this report, histomorphometric analyses confirmed increased alveolar bone loss and revealed increased numbers of TRAP+ osteoclastic cells lining the alveolar bone surface in SPF compared with GF mice. Increased numbers of RANKL+ cells and IL17+ cells in the periodontium of SPF mice demonstrate possible molecular mechanisms mediating the up-regulated osteoclastogenesis and alveolar bone loss in SPF mice compared with GF mice. Increased numbers of T-lymphocytic cells and T-helper cells in the junctional epithelium of SPF mice compared with GF mice suggest that the adaptive immune response contributes to physiologic alveolar bone loss in the healthy periodontium. This GF animal model study notably begins to elucidate the impact of host immunosurveillance mechanisms in response to the normal oral flora, mediating catabolic alveolar bone homeostasis in the healthy periodontium.

Inhibitory Potential of Postnatal Treatment with Cyclopamine, a Hedgehog Signaling Inhibitor, on Medulloblastoma Development in Ptch1 Heterozygous Mice

Medulloblastomas (MBs) are thought to be derived from granular cell precursors in the external granular layer (EGL) of the developing cerebellum. Heterozygous patched1 (Ptch1) knockout mice develop MBs that resemble those in humans when the sonic hedgehog (Shh) signaling pathway is activated. The present study was conducted to evaluate postnatal effects of a Shh signaling inhibitor, cyclopamine, on the development of MBs in Ptch1 mice. Ptch1 and wild-type mice were treated daily with subcutaneous cyclopamine at 40 mg/kg or vehicle from postnatal day (PND) 1 to PND14, and the subsequent development of MBs and preneoplastic lesions was examined up to week 12 (W12). Proliferative lesions in the cerebellum, MBs, and preneoplastic lesions were only detected in Ptch1 mice. Cyclopamine treatment resulted in a statistically significant reduction in the incidence and/or area of proliferative lesions at PND14 and 21. The trend of decreasing preneoplastic lesions persisted up to W12. At PND7, cyclopamine treatment reduced the width and proliferation of the EGL regardless of genotype. These results indicate that inhibition of Shh signaling during cerebellar development has prolonged inhibitory potential on MB development in Ptch1 mice. This inhibitory potential might be related to inhibition of EGL proliferation, including preneoplastic MB cells.

Effect of ADAMTS-13 on cerebrovascular microthrombosis and neuronal injury after experimental subarachnoid hemorrhage

BACKGROUND

Microthrombosis and reactive inflammation contribute to neuronal injury after subarachnoid hemorrhage (SAH). ADAMTS-13 cleaves von Willebrand factor multimers, and inhibits thrombus formation and, seemingly, inflammatory reactions.

OBJECTIVE

To investigate the effect of ADAMTS-13 in experimental SAH.

METHODS

A total of 100 male C57/BL6 mice were randomly assigned to four groups: sham (n = 15), SAH (n = 27), vehicle (n = 25), and ADAMTS-13 (n = 23; 100 μL per 10 g of body weight of 100 μg of ADAMTS-13 per 1 mL of 0.9% NaCl; 20 min after SAH). Neurologic performance was assessed on days 1 and 2 after SAH. Animals were killed on day 2. The amounts of subarachnoid blood, microthrombi, apoptosis and degenerative neurons were compared. The degree of neuronal inflammation and vasospasm was also compared. In five mice each (SAH and ADAMTS-13 groups), bleeding time was assessed 2 h after SAH.

RESULTS

Systemic administration of ADAMTS-13 achieved significant amelioration of microthrombosis and improvement in neurologic performance. ADAMTS-13 reduced the amount of apoptotic and degenerative neurons. A tendency for decreased neuronal inflammation was observed. ADAMTS-13 did not show any significant effect on vasospasm. The degree of systemic inflammation was not changed by ADAMTS-13 administration. ADAMTS-13 neither increased the amount of subarachnoid blood nor prolonged the bleeding time.

CONCLUSIONS

ADAMTS-13 may reduce neuronal injury after SAH by reducing microthrombosis formation and neuronal inflammation, thereby providing a new option for mitigating the severity of neuronal injury after SAH.

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.

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.

Ischemic brain metabolism in patients with chronic cerebrovascular disease: Increased oxygen extraction fraction and cerebrospinal fluid lactate

The aim of the present study is to elucidate the existence of chronically ischemic metabolism concomitant with misery perfusion of the brain in patients with chronic cerebrovascular disease. For this purpose, we measured cerebral blood flow (CBF) and oxygen metabolism by positron emission tomography (PET) and also determined cerebrospinal fluid (CSF) lactate as an indicator of the ischemic brain metabolism. Twenty-eight patients with chronic ischemic stroke and transient ischemic attack (TIA), who had angiographically occlusive (n = 11), stenotic (n = 10), and nonstenotic changes (n = 7) of the carotid artery and/or the intracranial major artery, were selected for this study. CBF, oxygen extraction fraction (OEF), cerebral metabolic rate for oxygen (CMRO2), and cerebral blood volume (CBV) were determined by PET, and CSF lactate and pyruvate were determined by enzymatic method in the patients with various grades of stenotic changes of the carotid artery. There were no significant differences in PET parameters and CSF variables among the groups of the occlusive, stenotic, and nonstenotic carotid artery. However, CSF lactate was correlated negatively with mean bilateral hemispheric (m)CBF (R(2) = 0.229, P<.01), positively with mOEF (R(2) = 0.278, P<.005) and more highly with mCMRO2/CBF (absolute extraction of oxygen content to the brain) (R(2) = 0.473, P<.0001) in all patients. There was no correlation between CSF lactate and mCMRO2 or mCBV. None of the cases in the nonstenotic group showed mOEF greater than 0.45, or mCMRO2/CBF greater than 7.9 vol%, while 80% of the cases in the stenotic group and 82% of the cases in the occlusive group showed mOEF and mCMRO2/CBF exceeding the above-mentioned values, respectively. The present findings, that increased mOEF and mCMRO2/CBF were significantly correlated with increased CSF lactate, indicate the brain to be in a metabolically ischemic state or increased anaerobic glycolysis with oxygen metabolism maintained in patients with chronic ischemic stroke.

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.

Thickened area of external granular layer and Ki-67 positive focus are early events of medulloblastoma in Ptch1⁺/⁻ mice

Patched1 (Ptch1) encodes a receptor for Sonic hedgehog (Shh) and is major gene related to human medulloblastoma (MB) in the Shh subgroup. MB is thought to arise from residual granule cell precursors (GCPs) located in the external granular layer (EGL) of the developing cerebellum. As the detailed preneoplastic changes of MB remain obscure, we immunohistochemically clarified the derived cell, early events of MBs, and the cerebellar developmental processes of Ptch1(+/-) (Ptch1) mice, an animal model of human MB of the Shh subgroup. In Ptch1 mice, the earliest proliferative lesions were detected at PND10 as focal thickened areas of outer layer of the EGL. This area was composed of GCP-like cells with atypia and nuclei disarrangement. In the latter cerebellar developmental period, GCP-like cell foci were detected at high incidence in the outermost area of the cerebellum. Their localization and morphological similarities indicated that the foci were derived from GCPs in the EGL. There were two types of the foci. A Ki-67-positive focus was found in Ptch1 mice only. This type resembled the GCPs in the outer layer of EGL characterized by having proliferating activity and a lack of neuronal differentiation. Another type of focus, Ki-67-negative, was observed in both genotypes and exhibited many of the same features of mature internal granule cells, suggesting that the focus had no preneoplastic potential. Due to morphological, immunohistochemical characteristics, our results indicate that the focal thickened area of EGL and Ki-67-positive foci are preneoplastic lesions of MB.

Development of an early induction model of medulloblastoma in Ptch1 heterozygous mice initiated with N-ethyl-N-nitrosourea

Mice heterozygous for the ptch1 gene (ptch1 mice) are known as a valuable model of medulloblastoma, a common brain tumor in children. To increase the incidence and reduce the time required for tumor development, allowing for evaluation of modifier effects on medulloblastoma in a short time, we attempted to develop an early induction model of medulloblastoma in ptch1 mice initiated with N-ethyl-N-nitrosourea (ENU). Ptch1 mice and their wild-type littermates received a single intraperitoneal injection of ENU (10, 50 or 100 mg/kg) on postnatal day 1 (d1) or 4 (d4), and histopathological assessment of brains was conducted at 12 weeks of age. The width of the external granular layer (EGL), a possible origin of medulloblastoma, after injection of 100 mg ENU on d1 or d4 was measured in up to 21-day-old mice. Cerebellar size was apparently reduced at the 50 mg dose and higher regardless of genotype. Microscopically, early lesions of medulloblastomas occurred with a high incidence only in ptch1 mice receiving 10 mg on d1 or d4, but a significant increase was not observed in other groups. Persistent EGL cells and misalignment of Purkinje cells were increased dose-dependently. Although EGL was strikingly decreased after ENU injection, strong recovery was observed in mice of the d1-treated group. In summary, neonatal treatment with ENU is available for the induction of medulloblastoma in ptch1 mice, and 10 mg of ENU administered on d1 appeared to be an appropriate dose to induce medulloblastoma.

Roles of nectins in cell adhesion, signaling and polarization

Nectins are Ca(2+)-independent immunoglobulin-like cell-cell adhesion molecules which constitute a family of four members. Nectins homophilically and heterophilically trans-interact and cause cell-cell adhesion. This nectin-based cell-cell adhesion plays roles in the organization of adherens junctions in epithelial cells and fibroblasts and synaptic junctions in neurons in cooperation with cadherins. The nectin-based cell-cell adhesion plays roles in the contacts between commissural axons and floor plate cells and in the organization of Sertoli cell-spermatid junctions in the testis, independently of cadherins. Nectins furthermore regulate intracellular signaling through Cdc42 and Rac small G proteins and cell polarization through cell polarity proteins. Pathologically, nectins serve as entry and cell-cell spread mediators of herpes simplex viruses.

Treatment for superficial esophageal cancer based on histological features and gross appearance

According to the depth of invasion, sixty-one superficial esophageal cancers (SECs) were subclassified as follows: intraepithelial cancer (ep), mucosal cancer invading to the lamina propria mucosa (lpm), or to the muscularis mucosa (mm), and submucosal cancer limited to the inner one-third of the submucosal layer (sm1), to the middle one-third (sm2), or invading into the outer one-third (sm3) to investigate the relationship between the depth of invasion and gross type classified according to the Guidelines of the Japanese Research Society for Esophageal Disease. Our results show that the SECs comprised of 9 ep cancers, 8 lpm, 6 mm, 6 sm1, 19 sm2 and 13 sm3, none of the ep or lpm cancers had either lymph node metastasis or recurrence and one-third of the mm and sml cancers had metastasis only in the mediastinal nodes. One-third of the sm2 and sm3 cancers, otherwise, revealed nodal involvement at surgery, and one-fourth of those recurred postoperatively. Recurrence in the cervical nodes was found in 9% of these cancers. All the SECs of the gross types including protruding type, slightly elevated type more than 2 cm in diameter and distinctly depressed type were submucosal cancers, whereas all the SECs showing the gross types including flat type and slightly elevated type less than 2 cm in diameter were ep or lpm cancers. Therefore, we concluded that for SEC evaluated as flat or slightly elevated type less than 2 cm in diameter by the endoscopic examination, less radical treatment such as endoscopic mucosal resection (EMR) should be performed at first.