Gradient subthalamic neurodegeneration and tau pathology in the hypoglossal nucleus as essential pathological markers of progressive supranuclear palsy - Richardson syndrome.

Progressive supranuclear palsy - Richardson syndrome (PSP-RS) was first described in 1964 by Steele et al. Tau pathology has not been reported in the hypoglossal nuclei of PSP-RS patients, whereas Steele et al. described gliosis with no remarkable neuronal losses in the hypoglossal nucleus. This study aimed to investigate the distribution and degree of tau pathology-associated neurodegeneration, with an emphasis on the hypoglossal nucleus, in patients with PSP-RS. Six clinicopathologically proven PSP-RS cases were included in this study. All patients were clinicopathologically and immunohistochemically re-evaluated. This study confirmed the following neuropathological characteristics of PSP-RS: (1) neurodegeneration usually affects the striatonigral system and cerebellar dentate nucleus; (2) the cerebellar afferent system in PSP-RS is affected by absent-to-mild neurodegeneration; and (3) the extent of tau distribution throughout the central nervous system is greater than the extent of neurodegeneration. Furthermore, we found that subthalamic neurodegeneration was more prominent in the ventromedial region than in the dorsolateral region. Nevertheless, the tau pathology showed no remarkable differences between these two sites. Interestingly, the tau pathology was frequently observed in the hypoglossal nuclei of PSP-RS patients. Gradient neurodegeneration of the subthalamus and tau pathology in the hypoglossal nucleus could be regarded as essential pathological features of PSP-RS.

The relationship between age and minimum alveolar concentration of sevoflurane for maintaining bispectral index below 50 in children.

We evaluated the minimum alveolar concentration of sevoflurane required to maintain the bispectral index below 50 in children. We studied 55 children, divided into 1-year-old, 2- to 4-year-old and 5- to 9-year-old groups and used Dixon's up-and-down method and probit analysis. In the 1-year-old group, the bispectral index values remained above 50, with the end-tidal sevoflurane concentration reaching 4.0% or higher. The minimum alveolar concentration of sevoflurane for maintaining the bispectral index below 50 was significantly higher in the 2- to 4-year-old group (2.33%, 95% CI 2.25-2.57) than in the 5- to 9-year-old group (2.10%, 95% CI 1.94-2.25; p = 0.005). We conclude that assessing the depth of anaesthesia using bispectral index is unreliable in children aged < 2 years anaesthetised with sevoflurane.

Suitability of polymers as screw post materials in primary teeth: an in vitro study.

AIM: Primary teeth undergo physiological root resorption during the transition to permanent dentition. The aim of this study was to assess the potential use of screw posts in core build-up for primary teeth while adequately retaining the crown restoration and allowing smooth physiological root resorption. METHODS: To determine whether biodegradable polymers such as polyglycolic acid (PGA) and poly-L-lactic acid (PLLA) were appropriate as post materials, bending strength test and bending elastic modulus test were performed according to ISO standards. The prepared screw posts were immersed in 0.01 mol/L phosphate-buffered saline at 37 degrees Celsius, and changes due to hydrolysis were observed. Results In the bending strength test and bending elastic modulus test, PGA and PLLA showed similar values to composite resins used for core build-up. Although both showed adequate hydrolysis, the hydrolysis rate of PGA was higher than that of PLLA. CONCLUSION: PGA and PLLA may be suitable as biodegradable screw posts for primary teeth because they have appropriate strength and hydrolysis ability.

First Report of Tomato leaf curl New Delhi virus Infecting Cucumber in Central Java, Indonesia.

Cucumber (Cucumis sativus L.) is an important vegetable in Indonesia. Cucumber plants showing yellowy green mosaic symptoms on leaves were observed in Klaten, Central Java, Indonesia in August 2008. Total DNAs were extracted from symptomatic leaves, and the putative viral genomes were amplified by PCR with the Deng A and B primers (2). The PCR-amplified viral genomic DNA was sequenced. The remaining part of DNA-A was amplified with two primers sets (ToLCNDV-A1F 5'-ACCAACAGGCCGATGAACA-3' and ToLCNDV-A1R 5'-TTCCCACTATCTTCCTGTGCA-3'; ToLCNDV-A2F 5'-TCGAGTGTGATRAAGAYTGCA-3' and ToLCNDV-A2R 5'-ACTAACTAAGCATTGCAGCGTC-3' [R = A and G, Y = C and T]) and sequenced. The remaining part of DNA-B was amplified with two primers sets (ToLCNDV-B1F 5'-ARGAGTTYMCRYYTGTGGA-3' and ToLCNDV-B1R 5'-TKCWGTYGGTCATGTCGT-3'; ToLCNDV-B2F 5'-TCYGTCAATCKCATGTCGYGT-3' and ToLCNDV-B2R 5'-CCTTACGCGTATAYTGTYTRGA-3' [K = G and T, M = A and C, W = A and T]) and sequenced. Full-length DNA-A (2,739 nt; GenBank Accession No. AB613825) and DNA-B (2,690 nt; GenBank Accession No. AB613826) sequences of a bipartite Tomato leaf curl New Delhi virus (ToLCNDV) from Central Java were obtained and they were most similar to the corresponding sequences of both DNA-A and DNA-B of ToLCNDV-[cucumber:Thailand] (DNA-A, GenBank Accession No. AB330079; DNA-B, GenBank Accession No. AB330080) at 95.5 and 91.0% nucleotide identities, respectively. On the basis of high nucleotide sequence identity with ToLCNDV-[cucumber:Thailand] and the demarcation criteria in species identification (3), the virus isolate from the diseased cucumber in Central Java is considered as a variant of ToLCNDV and was accordingly named ToLCNDV-Indonesia[Indonesia:Java:Cucumber:2008] (ToLCNDV-ID[ID:Jav:Cuc:08]). Although the importance of begomovirus diseases on chili pepper (Solanaceae) is currently highly noticed in Indonesia (1), ToLCNDV was newly isolated from cucumber (Cucurbitaceae) in this study. Therefore, farmers in Indonesia should pay more attention to controlling begomovirus vectors, white flies, on Cucurbitaceae. To our knowledge, this is the first report of the natural occurrence of ToLCNDV in Indonesia. References: (1) P. J. D. Barro et al. Biol. Invas.10:411, 2008. (2) D. Deng et al. Ann. Appl. Biol. 125:327, 1994. (3) C. M. Fauquet et al. Arch. Virol. 153:783, 2008.

New methods for determination of the keyhole position in the lateral suboccipital approach to avoid transverse-sigmoid sinus injury: Proposition of the groove line as a new surgical landmark.

PURPOSE: The asterion is frequently used as an anatomical landmark to determine the location of a keyhole in the lateral suboccipital approach used in craniotomies. However, the asterion may not be ideal because of large individual differences among patients. We examined a simple and safe method for determining an optimal keyhole position (KP) using the digastric groove as a new landmark in the lateral suboccipital approach. METHODS: Thirty-three patients with trigeminal neuralgia who underwent surgery in our institute between April 2014 and December 2018 were included. The groove line (GL) was designed accurately, extending the digastric groove on the surface of the occipital bone, as the x-axis. The y-axis was depicted from the posterior edge of the digastric groove (the groove point: GP) vertical to the GL. The x-y coordinates represented the distances from GP on each axis. The x-y coordinates of median edge of the transverse-sigmoid sinus (TSJ point), asterion, and the intersection of the GL and transverse sinus (the transverse point: TP) were investigated, based on intraoperative findings and recorded videos. RESULTS: The x-y coordinated of the TSJ point were (23.9±3.9, 7.2±3.6). In all patients, the TSJ point was located superior to the GL. The x-y coordinates of the asterion were (27.3±6.0, 8.9±4.1), and in 28 of the 33 patients, their coordinates exceeded the TSJ points. The x-coordinate of the TP was 29.5±4.5, and was located behind the TSJ point on the GL in all patients. The shortest distance between the TSJ points and TP was approximately 3mm. According to these measurements, we decided that the optimal KP would be at 20mm from the GP, subjacent to the GL. CONCLUSIONS: Our methods of using the GL as a new surgical landmark for setting the optimal KP is simple, safe, and useful.

Change in carrier type in high-k gate carbon nanotube field-effect transistors by interface fixed charges.

We study the phenomenon of change in carrier type in carbon nanotube field-effect transistors (CNFETs) caused by the atomic layer deposition (ALD) of a HfO(2) gate insulator. When a HfO(2) layer is deposited on a CNFET, the type of carrier changes from p-type to n-type. The so-obtained n-type device has good performance and stability in air. The conductivity of such a device with a channel length of 0.7 microm is 11% of the quantum conductance 4e(2)/h. The contact resistance for electron current is estimated to be 14 kOmega. The n-type conduction of this CNFET is maintained for more than 100 days. The change in carrier type is attributed to positive fixed charges introduced at the interface between the HfO(2) and SiO(2) layers. We also propose a novel technique to control the type of conduction by utilizing interface fixed charges; this technique is compatible with Si CMOS process technology.

A first-order liquid-liquid phase transition in phosphorus

First-order structural phase transitions are common in crystalline solids, whereas first-order liquid-liquid phase transitions (that is, transitions between two distinct liquid forms with different density and entropy) are exceedingly rare in pure substances. But recent theoretical and experimental studies have shown evidence for such a transition in several materials, including supercooled water and liquid carbon. Here we report an in situ X-ray diffraction observation of a liquid-liquid transition in phosphorus, involving an abrupt, pressure-induced structural change between two distinct liquid forms. In addition to a known form of liquid phosphorus--a molecular liquid comprising tetrahedral P4 molecules--we have found a polymeric form at pressures above 1 GPa. Changing the pressure results in a reversible transformation from the low-pressure molecular form into the high-pressure polymeric form. The transformation is sharp and rapid, occurring within a few minutes over a pressure range of less than 0.02 GPa. During the transformation, the two forms of liquid coexist. These features are strongly suggestive of a first-order liquid-liquid phase transition.

An African pygmy hedgehog adenovirus 1 (AhAdV-1) outbreak in an African pygmy hedgehog (Atelerix albiventris) colony in Japan.

An African pygmy hedgehog adenovirus 1 (AhAdV-1) outbreak in a colony of 24 African pygmy hedgehogs (APHs) with a case of fatal pneumonia occurred in Japan. Thirteen out of a colony of 15 APHs with respiratory symptoms were diagnosed with AhAdV-1 infection based on the detection of AhAdV-1 genome in throat/nasal swabs and further one APH was diagnosed on isolation of the virus. Five infected APHs died during the outbreak and AhAdV-1 caused severe pneumonia and death in one case. After the outbreak, persistent AhAdV-1 infection was suggested in one surviving APH. AhAdV-1 is a novel adenovirus and is suspected to be an emerging pathogen.

Impact of double-balloon endoscopy on the diagnosis of jejunoileal involvement in primary intestinal follicular lymphomas: a case series.

In recent years, primary gastrointestinal follicular lymphoma has been increasingly detected in the duodenum on esophagogastroduodenoscopy (EGD). Primary gastrointestinal follicular lymphomas are frequently distributed to multiple sites in the gastrointestinal tract. Therefore, investigation into the spread of follicular lymphomas in the small bowel is important in order to determine the most appropriate treatment strategy. The performance of double-balloon endoscopy (DBE) in the diagnosis of jejunoileal follicular lymphoma lesions has not been fully evaluated. We aimed to investigate the value of DBE in addition to computed tomography (CT) and (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG-PET) in the diagnosis of jejunoileal follicular lymphoma. DBE with biopsy was performed in seven patients with primary duodenal follicular lymphoma diagnosed by EGD, in order to investigate jejunoileal involvement. Jejunoileal follicular lymphoma lesions were detected by DBE in six out of the seven patients (three in the jejunum and three in the jejunum and ileum), whereas CT and (18)F-FDG-PET failed to detect the existence of these lesions. Endoscopic findings of the jejunoileal lesions revealed multiple white nodules and white villi, which were similar to those of duodenal lesions. DBE was more useful for the diagnosis of jejunoileal involvement in primary intestinal follicular lymphoma than CT and (18)F-FDG-PET. The use of DBE will become important for determining the most appropriate treatment for gastrointestinal follicular lymphoma.

Plasma hormone levels and semen quality in male cats during non-breeding and breeding seasons.

Female cats are known to be seasonal breeders and male cats annual breeders. Despite this, there are limited data on the influence of breeding season (BS) on hormone concentration and semen quality in the male cat. This study compared plasma concentrations of LH and testosterone (T), and semen quality during the non-breeding season (NBS) and BS in five male cats subject to natural hours of daylight but a constant environmental temperature. Plasma LH and T concentrations were higher during the BS in 2/35 and 3/5 cats, respectively, although when comparing both hormones combined, values were higher during the BS than the NBS in all cats (p < 0.01). There were no significant differences in the percentage of abnormal sperm between the cats. Overall, semen quality was superior during the BS with larger semen volume in 2/5, sperm motility in 2/5 and sperm viability in 3/5 cats. Although there was a clear seasonal effect on hormone secretion and semen quality, during the NBS all cats were likely to have been fertile.

Plasma LH, ovulation and conception rates in cats mated once or three times on different days of oestrus.

Although cats are induced ovulators, the relationship between the day of breeding, the number of matings and the likelihood of ovulation and conception have not been extensively investigated. In this experiment, cats were mated either once or three times on day 1 or day 5 of oestrus to study the incidence of the LH surge, ovulation and conception rates. The percentage ovulating and the conception rates after a single mating on day 1 of oestrus were 60% (6/10) and 33.3% (2/6), respectively, and for cats mated once on day 5 of oestrus were 83.3% (10/12) and 40% (4/10), respectively. When cats were mated three times on day 1 of oestrus, the ovulation rates and conception rates were 70% (7/10) and 85.7% (6/7), respectively, and for those mated three times on day 5 of oestrus were 100% (10/10) and 100% (10/10), respectively. The concentration of LH did not increase in non-ovulating cats, and cats that were mated three times had LH concentrations that were numerically higher than those that were mated once. Litter size was neither related to the day of mating nor to the number of matings. Although an increase in the number of matings on day 1 of oestrus produced a numerically larger LH surge, it did not increase the ovulation rate, suggesting that plasma oestradiol concentrations were not sufficiently elevated to induce a high pituitary response to mating stimulation. The conception rate after a single mating was low, suggesting that the number of sperm per mating was not sufficient. These results suggest that mating more than once in the middle of oestrus is required to improve ovulation rates and conception rates in cats.

The role of the ovary for the maintenance of pregnancy in cats.

Plasma progesterone (P(4)) concentrations are maintained in pregnant cats until parturition, but become low in pseudopregnant cats 40-45 days after infertile mating. This difference in P(4) concentrations is considered to be due to P(4) secretion by the placenta of pregnant cats. Therefore, to clarify these points, we performed ovariectomy (OVX) at various stages of pregnancy, examined the pregnancy status and measured LH and P(4) concentrations in peripheral, ovarian and uterine venous blood. After OVX, abortion occurred in 100% (5/5), 80% (4/5), 40% (2/5) and 60% (3/5) of Groups I (Day 35), II (Day 40), III (Day 45) and IV (Day 50) cats, respectively. In the remaining cats, normal delivery took place on days 63-69 [mean, 66.1 +/- 1.1 (SE)] of pregnancy. The time to abortion after OVX was 4-8 (mean, 5.6 +/- 0.8), 3-17 (mean, 8.0 +/- 3.6), 10 and 11, and 2-4 (mean, 3.0 +/- 0.7) days in Groups I, II, III and IV, respectively. The plasma P(4) concentrations were 1-2 ng/ml in all groups on the day after OVX, decreasing to less than 1 ng/ml from the 2nd day onwards. The concentrations of P(4) in ovarian venous blood at the time of OVX decreased with the stage of pregnancy, but were clearly higher than those in peripheral blood. The plasma P(4) concentrations in uterine venous blood were similar to those in peripheral blood. These results suggest that peripheral P(4) in pregnant cats is the result of P(4) secretion secreted only by the ovarian corpus luteum, not by the placenta, but indicate that either P(4) is not essential for the maintenance of pregnancy in cats from day 40-45 of pregnancy onwards, or that the placenta provides a local source of P(4) that does not appear in measurable amounts in the peripheral circulation.

Spinal anterior horn cells in sporadic amyotrophic lateral sclerosis show ribosomal detachment from, and cisternal distention of the rough endoplasmic reticulum.

AIMS: Sporadic amyotrophic lateral sclerosis (ALS) is a progressive and invariably fatal disease involving the upper and lower motor neurones of adult humans. Among the neuropathological features of the disease, abnormalities in the protein-synthesizing system in motor neurones of the brainstem and spinal cord, such as a decrease of cytoplasmic RNA and rough endoplasmic reticulum (rER) (chromatolysis), defective editing of the Q/R site of the glutamate receptor subunit GluR2 mRNA, fragmentation of the Golgi apparatus and accumulation of ubiquitinated inclusions and abnormal TdP-43 protein have been reported to be essential for the degeneration. In relation to these features, although the possibility of ER stress has been reported in motor neurones of the brainstem and spinal cord of ALS patients, the rER itself has not been a main target of ultrastructural investigation. METHODS: The present study examined the rER, ultrastructurally and quantitatively in the spinal anterior horn cells (AHCs) of 21 Japanese patients with sporadic ALS and eight Japanese control subjects. RESULTS AND CONCLUSIONS: It was found that: (i) the rER cisternae in AHCs showing central chromatolysis were fragmented, but retained their width and had normally attached ribosomes, and (ii) the rER cisternae in shrunken AHCs were irregularly distended with detachment of the ribosomes, thus suggesting that (iii) ribosomal detachment was related to rER distention.

Vascular endothelial growth factor in monochorionic twins with twin-twin transfusion syndrome.

OBJECTIVE: The purpose of this study was to determine vascular endothelial growth factor (VEGF) concentrations in the donor and the recipient in monochorionic twin pregnancies with twin-twin transfusion syndrome (TTTS) and single pregnancies in order to investigate the involvement of VEGF in the pathophysiology of TTTS. METHODS: Six twin pregnancies in 11 monochorionic twin pregnancies complicated with TTTS and 11 single control pregnancies were compared. Gestational age-matched fetal blood and placental samples were obtained at birth. Serum VEGF concentration in the umbilical vein was measured by an enzyme-linked immunoabsorbant assay. Tissue protein expression of VEGF was determined by using immunohistochemistry. Western blot analysis and scanning densitometry were used to quantify and compare the VEGF expression in the terminal villi. RESULTS: Serum VEGF concentrations in the umbilical vein in both donors and recipients tended to be higher than those in the controls. Immunolocalization of VEGF in terminal villous placenta samples in both donors and recipients was mainly observed in the syncytiotrophoblastic layer and vascular endothelial cells with less intense staining in stromal cells. The expression of VEGF in the donor placenta increased significantly (p=0.006) compared to that in the control placenta, but the expression of VEGF in the recipients tended to be higher than in the controls. CONCLUSION: Intrauterine circulatory imbalance may induce changes in VEGF expression and these alterations may be involved in both donor and recipient in the pathogenesis of TTTS, due to the maintenance of hemodynamic stability between the circulation of the twins.

Molecular epidemiological survey and phylogenetic analysis of bovine influenza D virus in Japan.

The influenza D virus, a new member of the Orthomyxoviridae family, is predominantly found in cattle. Although viral pathology and clinical disease in cattle appear mild, this virus plays an important role as a trigger of bovine respiratory disease (BRD). BRD is a costly illness worldwide. Thus, epidemiological surveys of the influenza D virus are necessary. Here, we conducted a molecular epidemiological survey for the influenza D virus in healthy and respiratory-diseased cattle in Japan. We found that 2.1% (8/377) of the cattle were infected with influenza D. The cattle with and without respiratory symptoms had approximately equal amounts of the virus. A full-genome sequence analysis revealed that the influenza D virus that was isolated in Japan formed an individual cluster that was distinct from the strains found in other countries. These results suggest that this virus might have evolved uniquely in Japan over a long period of time and that the viral pathology of Japanese strains might be different from the strains found in other countries. Continuous surveillance is required to determine the importance of this virus and to characterize its evolution.

SWI/SNF complex is essential for NRSF-mediated suppression of neuronal genes in human nonsmall cell lung carcinoma cell lines.

Mammalian chromatin remodeling factor, SWI/SNF complex contains a single molecule of either Brm or BRG1 as the ATPase catalytic subunit. Here, we show that the SWI/SNF complex forms a larger complex with neuron-restrictive silencer factor (NRSF) and its corepressors, mSin3A and CoREST, in human nonsmall cell lung carcinoma cell lines. We also demonstrate that the strong transcriptional suppression of such neuron-specific genes as synaptophysin and SCG10 by NRSF in these non-neural cells requires the functional SWI/SNF complex; these neuronal genes were elevated in cell lines deficient in both Brm and BRG1, whereas retrovirus vectors expressing siRNAs targeting integral components of SWI/SNF complex (Brm/BRG1 or Ini1) induced expression of these neuronal genes in SWI/SNF-competent cell lines. In cell lines deficient in both Brm and BRG1, exogenous Brm or BRG1 suppressed expression of these neuronal genes in an ATP-dependent manner and induced efficient and specific deacetylation of histone H4 around the NRSF binding site present in the synaptophysin gene by a large complex containing the recruited functional SWI/SNF complex. Patients with Brm/BRG1-deficient lung carcinoma have been reported to carry poor prognosis; derepression of NRSF-regulated genes including these neuron-specific genes could contribute to enhance tumorigenicity and also would provide selective markers for Brm/BRG1-deficient tumors.

Signal transduction in SARS-CoV-infected cells.

Severe acute respiratory syndrome (SARS) is a newly found infectious disease that is caused by a novel human coronavirus, SARS coronavirus (SARS-CoV). Because the mortality rate of SARS patients is very high, understanding the pathological mechanisms of SARS not only in vivo but in vitro is important for the prevention of SARS. Activation of signaling pathways caused by SARS-CoV infection leads to the phosphorylation and activation of downstream molecules. Two conflicting cellular programs, apoptosis to eliminate virus-infected cells and survival to delay apoptosis by producing antiviral cytokines, occur in SARS patients. Recent studies regarding SARS and SARS-CoV have clarified that activation of mitogen-activated protein kinases (MAPKs) plays important roles in upregulation of cytokine expression and apoptosis both in vitro and in vivo. Both Akt and p38 MAPK are keys for determination of cell survival or death in SARS-CoV-infected cells in vitro. Agents being developed to target these signaling cascades may be important for the design of anti-SARS-CoV drugs. This review highlights recent progress regarding SARS-CoV biology, especially signal transduction in SARS-CoV-infected cells.

Symmetric temporal abnormalities on MR imaging in amyotrophic lateral sclerosis with dementia.

BACKGROUND AND PURPOSE: Our aim was to clarify imaging findings of amyotrophic lateral sclerosis with dementia (ALSD). MATERIALS AND METHODS: T2-weighted MR images (T2WI) of 3 patients with ALSD (2 men, 1 woman; 58-71 years of age) and 21 patients with ALS without dementia (12 men, 9 women; 46-74 years of age) were examined for frontotemporal lobar atrophy and signal-intensity alterations in the white matter of the anterior temporal lobes, corticospinal tracts (CST), and precentral gyri and in precentral cortices. The brain of one of the patients with ALSD was examined at autopsy. RESULTS: All patients with ALSD showed bilateral frontotemporal atrophy mostly with temporal lobe dominance. In the ALSD group, T2WI demonstrated hyperintensity in the subcortical white matter on the medial side of the anterior temporal lobes, whereas in the group without dementia, none showed this imaging finding. MR images demonstrated no abnormal signal-intensity changes in CST in the internal capsule or the brain stem in the ALSD group. In the group without dementia, 6 patients (28.6%) showed this imaging finding. In neuropathologic examinations of the brain of 1 patient with ALSD, myelin-stained sections of the brain demonstrated loss of myelin in the subcortical white matter on the medial side of the anterior temporal white matter. CONCLUSIONS: A symmetric pattern of frontotemporal atrophy and anteromedial subcortical hyperintensities in the temporal lobes on T2WI could be characteristic of ALSD.

Three-dimensional analysis of pathological characteristics of a microaneurysm.

UNLABELLED: The etiology of Charcot-Bouchard microaneurysms (MAs), especially before rupture, has been unclear. CASE REPORT: A surgical specimen of an MA was removed from an acute intracerebral hemorrhage in a 69-year-old man. The MA was fixed with formalin and embedded in paraffin, and serial sections were cut and stained by the Azan and Elastica van Gieson methods and immunohistochemically. Three-dimensional reconstructive analysis was performed. RESULTS AND DISCUSSION: The MA presented as local enlargement of an artery with a maximal diameter of 840 microm, but was not ruptured. The wall of the MA consisted of thickened, fine collagen fibrils, which were found to be similar to adventitia immunohistochemically, but with no internal elastic lamina or medial smooth muscle layer. The lumen was empty, with no mural thrombi, but the inner wall endothelial cells had expanded from the normal and/or residual arterial wall, which suggested that the MA had been present for a long period of time. Because the bare wall of the MA consisted of thickened collagen fibrils, the MA was not ruptured, but the possibility of rupture in the future was deemed high, with the risk of intracerebral hemorrhage.