Metagenomic Analysis of Bacterial Microflora in Dental and Atherosclerotic Plaques of Patients With Internal Carotid Artery Stenosis.

Background: Internal carotid artery stenosis is primarily attributed to atherosclerosis in the carotid artery bifurcation. Previous studies have detected oral bacteria in atherosclerotic lesions, suggesting an association between oral bacteria and atherosclerosis. In this study, we compared the bacterial flora of the atherosclerotic plaque in the carotid artery and dental plaque of patients with internal carotid artery stenosis using 16S ribosomal RNA (16S rRNA) metagenomic sequencing. Methods: Fifty-four patients who underwent internal carotid endarterectomy for internal carotid artery stenosis at the Showa University Hospital between April 2016 and February 2018 were included. Polymerase chain reaction targeting the 16S rRNA gene detected bacterial DNA in the carotid plaques of 11 cases, of which only 5 could be further analyzed. Thereafter, DNA extracted from the carotid and oral plaques of these 5 cases were analyzed using metagenomic sequencing targeting 16S rRNA. In addition, their general condition and oral conditions were evaluated. The patients were classified into symptomatic and asymptomatic groups based on the presence or absence of symptoms of transient ischemic attack, and their bacterial flora was evaluated. Results: The results demonstrated that the microflora of carotid plaques (n = 5) contained bacterial species from 55 families and 78 genera. In addition, 86.5% of the bacteria detected in the carotid plaques were also detected in oral plaques. Cariogenic and periodontopathic bacteria accounted for 27.7% and 4.7% of the bacteria in the carotid plaques, respectively. Conclusions: These results suggest that oral bacteria are directly or indirectly involved in the pathogenesis of atherosclerosis. More extensive studies of oral commensal bacteria detected in extra-oral lesions are warranted to comprehensively investigate the role of oral bacteria in the pathogenesis of systemic diseases.

Surgical treatment for extremely rare solitary fibrous tumors of the central nervous system originating from cranial nerve VIII: new clinicopathological findings. Illustrative case.

BACKGROUND: Reports of solitary fibrous tumors (SFTs) of the central nervous system (CNS) originating from cranial nerves are extremely rare. The origins of these neurogenic SFTs of the CNS have been determined only by intraoperative findings, and there is no pathological evidence of whether they really originated from cranial nerves. OBSERVATIONS: A 54-year-old female with hearing loss and facial paralysis presented with a giant right cerebellopontine angle tumor. She was diagnosed with a petrous meningioma based on preoperative imaging, and the tumor was removed via the retrosigmoid approach after embolization of the tumor-feeding vessels. Intraoperatively, the tumor was not attached to the dura mater but extended from the internal auditory canal to the cisternal portion. The acoustic nerve was not identified, but it was possible to separate the tumor from the facial nerve. The tumor was removed as an acoustic schwannoma intraoperatively. Postoperative pathological examination revealed an SFT. Immunostaining revealed peripheral nerve bundles entrapped within the tumor tissue. The patient was diagnosed with an SFT of the CNS originating from the acoustic nerve. LESSONS: A neurogenic SFT of the CNS was diagnosed based on both intraoperative and pathological findings.

Immobilization of E. coli expressing γ-glutamyltranspeptidase on its surface for γ-glutamyl compound production.

An Escherichia coli strain expressing γ-glutamyltranspeptidase on its extracellular surface using the Met1 to Arg232 fragment of YiaT of E. coli as an anchor protein was immobilized with alginate for repeated use. Measurement of γ-glutamyltranspeptidase activity of the immobilized cells was performed repeatedly at pH 8.73 and 37 °C for 10 days using γ-glutamyl-p-nitroanilide in the presence of 100 mM CaCl2 and 3% NaCl with and without glycylglycine. Even after the 10th day, the enzyme activity did not decrease from the initial levels. The production of γ-glutamylglutamine from glutamine using the immobilized cells was performed repeatedly at pH 10.5 and 37 °C for 10 days in the presence of 250 mM glutamine, 100 mM CaCl2, and 3% NaCl. Sixty-four % of glutamine was converted to γ-glutamylglutamine in the first cycle. While repeating the production 10 times, the surface of the beads gradually became covered with white precipitate, and the conversion efficiency gradually decreased, but 72% of the initial value still remained even at the 10th measurement.

Single-Center Case Series of Simple Proximal Clipping for Large Thrombosed Vertebral Artery Aneurysms: Preservation of Perforating Arteries and Long-Term Outcomes.

BACKGROUND: Surgical proximal parent artery occlusion (PAO) is one of the treatments for partially thrombosed vertebral artery aneurysms (PTVAs). However, whether long-term changes in size and perforating arteries through the blind end can be truly preserved remain unknown. OBJECTIVE: To evaluate the efficacy and safety of surgical proximal PAO for PTVAs, focusing on the transition in size and preservation of perforating arteries. METHODS: We retrospectively reviewed 14 consecutive cases of unruptured large PTVAs. The cases were treated with surgical proximal PAO without trapping or thrombectomy. Preservation of the perforating arteries was confirmed through intraoperative indocyanine green video angiography. The aneurysm size was evaluated by measuring the maximum diameter on axial T2-weighted magnetic resonance images. Post-treatment outcomes were assessed using the modified Rankin Scale at the last follow-up examination. RESULTS: Thirteen patients (excluding 1 with morbidity) had a mean follow-up time of 33.2 months (range, 12-60 months) and a mean reduction rate of 71% (range, 32%-95%). Only 1 patient (7.2%) experienced postoperative stroke, and 13 patients (92.8%) showed no worsening of the modified Rankin Scale score at the final follow-up examination. The symptoms were improved in 5 of the 6 symptomatic patients (83.3%). In 10 patients (71.4%), a perforating branch that could not be identified on preoperative imaging was identified intraoperatively. CONCLUSION: Surgical proximal PAO without trapping or thrombectomy for PTVAs allows long-term reduction of aneurysm size and improves treatment safety by preserving the perforating artery, especially in cases wherein direct reconstruction is not feasible.

Surgical treatment of hemifacial spasm caused by fusiform vertebral artery aneurysm: case report and literature review.

BACKGROUND: Root exit zone (REZ) compression by a fusiform vertebral artery (VA) aneurysm is a rare cause of hemifacial spasm (HFS). We report a case of successful microvascular decompression (MVD) for the treatment of HFS caused by a fusiform VA aneurysm. We also review the relevant literature and demonstrate the effectiveness of surgical treatment. CASE DESCRIPTION: A 64-year-old man presented with a 2-year and 4-month history of progressive involuntary facial twitching on the right side. Radiological examination revealed a fusiform right VA aneurysm. The REZ that was compressed by the aneurysm and the underlying anterior inferior cerebellar artery (AICA) was surgically decompressed by transposing the VA and AICA and wrapping the aneurysm. Immediately post-operation, the patient's symptoms disappeared. For 7 years and 4 months postoperatively, there was no symptom recurrence or increase in aneurysm size. CONCLUSION: MVD is an effective treatment for HFS caused by a fusiform VA aneurysm because symptoms are likely to improve immediately after treatment.

Development of Enzymatic Synthesis of γ-Glutamylcarnosine and Its Effects on Taste.

γ-Glutamyl peptides have amide bonds between the γ-carboxy group of glutamic acid and the amino group of amino acids or peptides. Some of these γ-glutamyl peptides are known as kokumi substances. Kokumi substances enhance the taste, mouthfulness, thickness, and continuity of the dish. γ-Glutamylcarnosine (γ-l-glutamyl-ß-alanyl-l-histidine) is a γ-glutamyl peptide, and this peptide has been suggested as a kokumi substance; however, its effects on taste have not been evaluated directly. As γ-glutamylcarnosine is not available commercially, the conditions for its enzymatic synthesis using a γ-glutamyltranspeptidation reaction of γ-glutamyltranspeptidase of Escherichia coli was optimized. The synthesized peptide was purified with a Dowex 1 × 8 column, and its structure was identified by mass spectrometry and NMR spectroscopy. This is the first report of the enzymatic synthesis of γ-glutamylcarnosine. Using this purified preparation, its effects on the sense of taste were investigated. However, the effects of γ-glutamylcarnosine on the sense of taste were not detected except for increased bitterness.

The algorithm for diagnosis and management of intracranial hypotension with coma: Report of two cases.

BACKGROUND: Spontaneous intracranial hypotension (SIH) is caused by spontaneous cerebrospinal fluid (CSF) leaks that can be treated in most cases with an epidural blood patch (EBP). However, some patients, who develop severe brain sagging, can neurologically deteriorate, and in occasional instances, which become comatose. Here, with the presentation of two cases, and a review of the literature, we have set guidelines for diagnosing SIH along with recommendations for its management. CASE DESCRIPTION: We reviewed two cases of SIH. Both patients became comatose due to a CSF leak associated with a tear in the spinal dura diagnosed on myelo-CT studies. As targeted EBP failed to achieve sustained improvement, direct operative repair of the dural tears was warranted (video presentation). CONCLUSION: After reviewing two cases of SIH and the literature, we developed an algorithm for the diagnosis and management of SIH. To avoid deterioration to a comatose status, we recommend the early performance of myelo- CT studies to identify the location of the dural leak, followed by early dural repair.

An Experimental Clamping and Cutting Study of Carotid and Intracranial Stents: Preparation for Surgical Rescue in Stent Complications.

OBJECTIVE: To carry out surgery safely in vessels with stents, it is essential to have knowledge of what would happen if the stents were clamped or cut. Using all stents that are permitted in Japan, we recorded with a surgical microscope the behavior of stents when they were clamped or cut and discussed the morphologic changes along with image findings. METHODS: We classified carotid artery and intracranial stents as group 1A and 1B or group 2A and 2B according to the structure of stent eye: laser cut or blade. Each stent was clamped using a Yasargil aneurysm clip, bulldog forceps, and vascular forceps. Degree of closure and presence or absence of stent deformation after declamping were recorded using a surgical microscope. Furthermore, we performed morphologic evaluations using high-resolution cone-beam computed tomography. Lastly, each stent was cut; the behavior of the cut stent was recorded, and differences between stents were examined. RESULTS: Complete clamping was confirmed both visually and based on image evaluations with bulldog forceps and vascular forceps in the groups of carotid artery stents, with the Yasargil aneurysm clip in the intracranial stents. In the blade-type stents, we found that the stents elongated during clamping, and the component wire scattered at the time of stent cutting. Furthermore, the stents could be easily separated by holding with forceps. CONCLUSIONS: Knowing the properties of each stent is essential to conduct safe surgery in response to complications. Special care must be taken when clamping and cutting blade-type stents.

Chondroma in the hypoglossal canal: A case report.

BACKGROUND: Intracranial chondromas are rare tumors arising from the skull base. They are usually accompanied by functional impairments of some cranial nerves. However, hypoglossal nerve dysfunction is rare. CASE DESCRIPTION: We report on a 57-year-old woman presenting with chondroma of the right hypoglossal canal leading to right hypoglossal nerve palsy. CONCLUSIONS: This report suggests that chondroma should be considered as a differential diagnosis in cases of hypoglossal lesions.

High performance demodulation method with less complexity for image-sensor communication.

This study presents a novel method for signal demodulation for use with visible light communication systems composed of an image sensor as a receiver and light-emitting diode (LED) transmitters. Demodulation is a central challenge in the design of such a system, as the image captured at the image-sensor receiver is deteriorated by distance and noise. We propose a demodulation method that offers performance approaching that of the maximum-likelihood decoding (MLD) method and with significantly less complexity. The proposed method first applies the minimum mean square error (MMSE) method to each LED into reliable LEDs and unreliable LEDs according to the MMSE results and it demodulates the LEDs judged as reliable directly. Then, the MLD method is applied only to the unreliable LEDs to demodulate their signals. The results of numerical simulations and lab experiments are presented to evaluate the performance of this modified demodulation method.

Distance Between the Falciform Ligament and Distal Dural Ring as a Surgical Landmark for the Treatment of Paraclinoid Aneurysms.

OBJECTIVE: It is difficult to completely comprehend the anatomy of the structures surrounding the paraclinoid region before aneurysm and tumor treatment therein. When treating paraclinoid aneurysms, it is important to determine the location of the aneurysm as intradural or extradural. Thus, accurate prediction of the position of the distal dural ring (DDR) is necessary. To this end, we focused on the falciform ligament (FL), which is easily visualized on images based on its anatomic features. We measured the distance between the FL and the DDR in patients undergoing paraclinoid aneurysm operations. METHODS: Between January 2017 and July 2018, 15 patients who underwent clipping for paraclinoid aneurysm treatment were retrospectively identified. The distance between the FL and the DDR was measured using a microscale at the time of the operation. RESULTS: The patients comprised 14 women and 1 man. The mean aneurysm diameter was 7.29 ± 2.21 mm and the median size was 6.5 mm. Eleven of the aneurysms were on the left and 4 were on the right side. The mean distance between the FL and the DDR was 3.50 ± 0.17 mm and the median distance was 3.50 mm. The distance between the FL and the DDR was almost the same across cases (3.5 mm). CONCLUSIONS: The position of the FL can be easily predicted using preoperative three-dimensional computed tomography angiography based on its anatomic features. In this study, the DDR was located 3.5 mm proximal to the FL along the internal carotid artery. This information is useful for predicting the position of the DDR.

Surgical Rescue Retrieval of a Filter Protection Device in Carotid Artery Stenting with Stent Deformation: Case Report and Literature Review.

BACKGROUND: Despite the development of neuroendovascular treatment, device-related complications requiring surgical procedures remain. We report a case requiring surgical retrieval of a filter protection device in carotid artery stenting (CAS) with an open-cell stent, due to stent deformation, and review past reports on CAS in which surgical retrieval of devices was required. CASE DESCRIPTION: An 82-year-old man underwent CAS for symptomatic right internal carotid artery stenosis with severe calcification and tortuosity. Immediately after placement of the open-cell stent, stent deformation was detected and the filter protection device could not be retrieved. All noninvasive device retrieval attempts failed, and the device was ultimately retrieved surgically. After surgery, right cerebral infarction progressed increased, but no permanent deficit was observed. CONCLUSIONS: As the treatment of cerebrovascular disease shifts from surgical to endovascular approaches, surgeons must be familiar with devices and techniques to manage complications of neuroendovascular treatment.

Is surgical parent artery occlusion effective for intracranial aneurysms measuring over 10 mm in size? Result from long-term follow-up of size changes and outcomes.

BACKGROUND: There have been no long-term follow-up reports pertaining to chronological size changes in large or giant unruptured intracranial aneurysms treated with surgical parent artery occlusion (PAO). The object of this study is to investigate the utility and safety of surgical PAO by conducting a long-term follow-up of chronological aneurysm size changes and outcomes. METHODS: A retrospective study of 21 unruptured intracranial aneurysms measuring over 10 mm (20 patients) treated with surgical PAO in the period 2012-2017 was conducted. For aneurysms presenting with anterior circulation, high/low flow bypass was chosen and carried out concomitantly on the basis of preoperative balloon occlusion test results. Aneurysm size before and after surgery was evaluated chronologically using maximum diameter measurements taken from the same slice of MRI T2-weighted images. Moreover, post-surgery outcomes were evaluated according to a modified Rankin scale (mRS) at discharge. RESULTS: PAO aiming for blind-alley formation was performed in 20 of 21 aneurysms (95.2%). Aneurysm size reduction was confirmed in 20 aneurysms (95.2%) after proper PAO, with an average reduction rate of 63.1% (range, 28-95%), during an average follow-up period of 27 months (range, 4-54 months). Eighteen (90.4%) of the 20 patients with 21 aneurysms returned to previous life with mRS score 0-2. With regard to preoperative symptoms, diplopia and visual impairment had improved in three patients (50%) and one patient (100%), respectively. Ischemic complications had occurred in five patients, two (9.6%) of whom were symptomatic and three (14.3%) were asymptomatic. The mortality rate in this study was 0%. CONCLUSIONS: Surgical PAO for unruptured intracranial aneurysms measuring over 10 mm has been shown to be an effective method of treatment, eliciting a reduction in aneurysm size.

Preoperative Embolization of Meningiomas: Differences in Surgical Operability and Histopathologic Changes Between Embosphere and N-butyl 2-cyanoacrylate.

OBJECTIVE: This study aimed to examine whether there is a difference in the difficulty of extirpation after use of Embosphere versus n-butyl 2-cyanoacrylate (NBCA) for the embolization of meningiomas. METHODS: Study subjects were 20 patients with meningioma who underwent embolization using either NBCA or Embosphere from April 2012 to December 2016. The difficulty of extirpation was compared and assessed in terms of objective indices, such as operative duration, perioperative bleeding, and Simpson grade, and in terms of subjective indices such as "impression on operative field" and "hardness of tumors" that the surgeon assessed using 3-point scales (dry, moderate, bloody, and soft, moderate, hard, respectively). Pathologic findings, including ischemia, necrosis, and inflammatory changes, were assessed. RESULTS: No significant differences were found between the 2 groups regarding the mean values of operative duration (P = 0.27), perioperative bleeding (P = 0.23), and Simpson grade (P = 0.39). On the other hand, there was a significant difference with respect to the "impression on operative field" and "hardness of tumors," with reports of dry (54%; P = 0.034) and soft (81%; P = 0.0001), respectively, in the Embosphere group exceeding those of the NBCA group. The pathologic findings showed that although ischemic change (P = 0.43) and necrosis (P = 0.79) were observed in both groups, perivascular inflammation was observed only in the NBCA group (P = 0.006). CONCLUSIONS: No relative merits were found regarding objective indices, whereas the Embosphere group had superior "ease of extirpation" as reported by the surgeon.

Bypass Surgeries in the Treatment of Cerebral Aneurysms.

BACKGROUND: During surgery for cerebral aneurysm, revascularization techniques are occasionally needed to (1) treat an aneurysm (trapping or flow alteration); (2) preserve blood flow during temporary parent artery occlusion (insurance); and (3) repair accidentally injured vessels (troubleshooting). Herein we present our surgical case experiences. METHODS: Revascularization modalities were employed in 33 (7.6 %) of 452 cases of surgically treated aneurysms. The aneurysm locations and associated required bypass procedures were: (1) 7 middle cerebral artery (MCA) aneurysms with 7 superficial temporal artery (STA)-MCA bypass procedures; (2) 10 internal carotid artery (ICA) aneurysms with 9 high-flow and 1 STA-MCA procedures; (3) 10 vertebro-basilar artery aneurysms with 2 high-flow, 6 occipital artery (OA)-posterior ICA, and 1 STA-superior cerebellar artery (SCA) procedures; (4) 1 posterior cerebral artery (PCA) aneurysm with OA-PCA bypass; and (5) 5 anterior cerebral artery aneurysms with 4 A3-A3 and 1 A3-STA-A3 procedure. Curative bypasses for aneurysmal treatment, temporary bypasses, and troubleshooting procedures were performed in 25, 3, and 5 cases, respectively. RESULTS: Among the 26 aneurysms treated via curative bypass, 16 aneurysms that were trapped or clipped using revascularization techniques had better outcomes (no aneurysmal rupture and 1 perforator infarction), whereas among the 10 aneurysms that could not be trapped or clipped and were thereby treated via flow alteration (e.g., bypass plus proximal artery clipping), 2 developed symptomatic infarction and 2 exhibited aneurysmal rupture after partial thrombosis. Patients whose bypass procedures were used for temporary parent artery occlusion (insurance) or troubleshooting had no complications. CONCLUSION: Complex aneurysm clipping or trapping using bypass techniques yielded good results. In particular, perforator vessel ischemia still requires resolution. Flow alteration techniques leading to aneurismal thrombosis carried the risks of ischemic and hemorrhagic complications when applied to intracranial aneurysms. Bypasses for temporary use or troubleshooting were quite effective.