[Melanocytic Tumors]

Primary melanocytic neoplasms of the central nervous system(CNS)presumably arise from leptomeningeal melanocytes that are derived from the neural crest. Melanocytic neoplasms associated with neurocutaneous melanosis likely derive from melanocyte precursor cells that reach the CNS after somatic mutations, mostly, of the NRAS. They should be distinguished from other melanotic tumors involving the CNS, including metastatic melanoma and other primary tumors that undergo melanization, such as melanocytic schwannomas, medulloblastomas, paragangliomas, and various gliomas, because these lesions require different patient workups and therapy. Primary melanocytic neoplasms of the CNS that are diffuse and do not form macroscopic masses are called melanocytoses, whereas malignant diffuse or multifocal lesions are collectively called melanomatoses. Benign and intermediate-grade tumoral lesions are called melanocytomas. Discrete malignant tumors are called melanomas. CT and MRI of melanocytosis and melanomatosis show diffuse thickening and enhancement of the leptomeninges, often with focal or multifocal nodularity. Depending on the melanin content, diffuse and circumscribed melanocytic tumors of the CNS may show some characteristics on CT and MRI: iso- to hyperattenuation on CT and paramagnetic properties of melanin on MRI resulting in an isointense signal on T1WIs and iso- to hypointensity on T2WIs.

Repeated cerebellar infarction in the affected nondominant vertebral artery distribution with reversible vertebral artery occlusion elicited by head tilt: illustrative case

BACKGROUND

Bow hunter’s syndrome or stroke (BHS) is characterized by rotational vertebrobasilar insufficiency elicited by rotation of the neck. It is caused by dynamic and reversible occlusion of the vertebral artery (VA). Reversible symptoms of rotational vertebrobasilar insufficiency are described as bow hunter’s syndrome, although brain infarction is rarely reported as bow hunter’s stroke.

OBSERVATIONS

A 70-year-old man experienced repeated cerebellar infarctions three times in the posterior inferior cerebellar artery (PICA) distribution of the nondominant right VA connecting the basilar artery. The onset of symptoms indicating cerebellar infarcts and the patient’s head position changes were unrelated. Dynamic digital angiography (DA) revealed that the nondominant right VA was occluded by an osteophyte from the C4 vertebral body, and the right PICA branches were shown to be passing through the distal right VA from the left VA. These findings were observed when the patient’s head was tilted to the right. An arterio-arterial embolic mechanism was suggested as the cause of repeated cerebellar infarctions.

LESSONS

Transient nondominant VA occlusion has been rarely reported as a cause of BHS when the head is tilted. To confirm the diagnosis of BHS, additional head tilt is recommended when performing dynamic DA in patients with a cervical osteophyte.

Inhibition of growth and virulence of Vibrio cholerae by carvacrol, an essential oil component of Origanum spp

AIMS

In the age where bacterial resistance to conventional antibiotics is increasing at an alarming rate, the use of the traditional plant, herb extracts or other bioactive constituents is gradually becoming popular as an anti-virulence agent to treat pathogenic diseases. Carvacrol, a major essential oil fraction of Oregano, possesses a wide range of bioactivities. Therefore, we aimed to study the effect of sub-inhibitory concentrations of carvacrol on major virulence traits of Vibrio cholerae.

METHODS AND RESULTS

We have used in vitro as well as ex vivo models to access the anti-pathogenic role of carvacrol. We found that the sub-inhibitory concentration of carvacrol significantly repressed bacterial mucin penetrating ability. Carvacrol also reduced the adherence and fluid accumulation in the rabbit ileal loop model. Reduction in virulence is associated with the downregulated expression of tcpA, ctxB, hlyA and toxT. Furthermore, carvacrol inhibits flagellar synthesis by downregulating the expression of flrC and most of the class III genes.

CONCLUSIONS

Carvacrol exhibited anti-virulence activity against V. cholerae, which involved many events including the inhibition of mucin penetration, adhesion, reduced expression of virulence-associated genes culminating in reduced fluid accumulation.

SIGNIFICANCE AND IMPACT OF THE STUDY

These findings indicate that carvacrol possesses inhibitory activity against V. cholerae pathogenesis and might be considered as a potential bio-active therapeutic alternative to combat cholera.

Pilot Study of Hyperpolarized 13C Metabolic Imaging in Pediatric Patients with Diffuse Intrinsic Pontine Glioma and Other CNS Cancers

BACKGROUND AND PURPOSE

Pediatric CNS tumors commonly present challenges for radiographic interpretation on conventional MR imaging. This study sought to investigate the safety and tolerability of hyperpolarized carbon-13 (HP-¹³C) metabolic imaging in pediatric patients with brain tumors.

MATERIALS AND METHODS

Pediatric patients 3 to 18 years of age who were previously diagnosed with a brain tumor and could undergo MR imaging without sedation were eligible to enroll in this safety study of HP [1-¹³C]pyruvate. Participants received a one-time injection of HP [1-¹³C]pyruvate and were imaged using dynamic HP-¹³C MR imaging. We assessed 2 dose levels: 0.34 mL/kg and the highest tolerated adult dose of 0.43 mL/kg. Participants were monitored throughout imaging and for 60 minutes postinjection, including pre- and postinjection electrocardiograms and vital sign measurements.

RESULTS

Between February 2017 and July 2019, ten participants (9 males; median age, 14 years; range, 10-17 years) were enrolled, of whom 6 completed injection of HP [1-¹³C]pyruvate and dynamic HP-¹³C MR imaging. Four participants failed to undergo HP-¹³C MR imaging due to technical failures related to generating HP [1-¹³C]pyruvate or MR imaging operability. HP [1-¹³C]pyruvate was well-tolerated in all participants who completed the study, with no dose-limiting toxicities or adverse events observed at either 0.34 (n = 3) or 0.43 (n = 3) mL/kg. HP [1-¹³C]pyruvate demonstrated characteristic conversion to [1-¹³C]lactate and [¹³C]bicarbonate in the brain. Due to poor accrual, the study was closed after only 3 participants were enrolled at the highest dose level.

CONCLUSIONS

Dynamic HP-¹³C MR imaging was safely performed in 6 pediatric patients with CNS tumors and demonstrated HP [1-¹³C]pyruvate brain metabolism.

Relativistic magnetic reconnection in laser laboratory for testing an emission mechanism of hard-state black hole system

Magnetic reconnection in a relativistic electron magnetization regime was observed in a laboratory plasma produced by a high-intensity, large energy, picoseconds laser pulse. Magnetic reconnection conditions realized with a laser-driven several kilotesla magnetic field is comparable to that in the accretion disk corona of black hole systems, i.e., Cygnus X-1. We observed particle energy distributions of reconnection outflow jets, which possess a power-law component in a high-energy range. The hardness of the observed spectra could explain the hard-state x-ray emission from accreting black hole systems.

Prognostic and predictive values of tumour budding in stage IV colorectal cancer

BACKGROUND

Tumour budding is an important prognostic feature in early-stage colorectal cancer, but its prognostic significance in metastatic disease has not been fully investigated.

METHODS

Patients with stage IV disease who had primary colorectal tumour resection without previous chemotherapy or radiotherapy from January 2000 to December 2018 were reviewed retrospectively. Budding was evaluated at the primary site and graded according to the criteria of the International Tumor Budding Consensus Conference (ITBCC) (BD1, low; BD2, intermediate; BD3, high). Patients were categorized by metastatic (M1a, M1b) and resectional (R0/R1, R2/unresected) status. Subgroups were compared for overall (OS) and recurrence-free (RFS) survival in R0/R1 subgroups; R2/unresected patients were evaluated for the rate of tumour progression, based on change in tumour size from baseline.

RESULTS

Of 371 patients observed during the study, 362 were analysed. Patients with BD3 had a lower 5-year OS rate than those with BD1 + BD2 (18·4 versus 40·5 per cent; P < 0·001). Survival analyses according to metastatic and resection status also showed that BD3 was associated with shorter OS than BD1 + BD2. In multivariable analysis, BD3 (hazard ratio (HR) 1·51, 95 per cent c.i. 1·11 to 2·10; P = 0·009), T4 status (HR 1·39) and R2/unresected status (HR 3·50) were associated with decreased OS. In the R0/R1 subgroup, the 2-year RFS rate was similar for BD3 and BD1 + BD2 according to metastatic status. There was no significant difference between BD3 and BD1 + BD2 for change in tumour size in the R2/unresected subgroup (P = 0·094). Of 141 patients with initially unresectable metastases who had chemotherapy, 35 achieved conversion from unresectable to resectable status. The conversion rate was significantly higher for BD1 + BD2 than for BD3 (36 versus 18 per cent; P = 0·016).

CONCLUSION

Stage IV colorectal cancer with high-grade tumour budding according to ITBCC criteria correlates with poor prognosis.

COT-21 EFFECT OF BEVACIZUMAB FOR PEDIATRIC HIGH GRADE GLIOMA

INTRODUCTION

Bevacizumab (BEV) therapy has been used for pediatric high grade glioma,however the evidence and effectiveness are not understood yet.

METHODS

We report 7 cases (age 2 to 10 years old) of pediatric high grade glioma treated with BEV. One case is thalamic diffuse midline glioma H3K27 mutant (DMGH3K27M),one case is brain stem DMGH3K27M,one case is cerebellar high grade glioma,and 4 cases are diffuse intrinsic pontine glioma (DIPG) diagnosed clinically without biopsy. 5 cases were treated with BEV when diagnosed as recurrence after chemo-radiotherapy. One case was treated for rapid tumor progression during radiotherapy. One case was started on BEV therapy with radiation and concomitant temozolomide therapy.

RESULT

The number of times of BEV was 2 to 13 times (median 7 times). The period of BEV was 1 to 9 months (median 4 months). One case which was treated with BEV at rapid progression during radiation showed good response on imaging and improvement of symptoms. 4 of 5 cases who were treated at recurrence clinically showed mild symptomatic improvement. One case treated with BEV and radiotherapy initially was not evaluated. The adverse effects of BEV included wound complication of tracheostomy and rash.

CONCLUSION

BEV showed good response for rapid progression during radiotherapy,and mild response for recurrence cases. BEV is thought to be an effective therapeutic agent for pediatric HGG at recurrence and rapid tumor progression during radiotherapy.

Vascular Hyperintensity on Fluid-Attenuated Inversion Recovery Indicates the Severity of Hypoperfusion in Acute Stroke

BACKGROUND AND AIM

Although fluid-attenuated inversion recovery vascular hyperintensities may be frequently seen in acute large-artery ischemic stroke, reports on their prognostic utility had been conflicting due to lack of quantitative evaluation of the perfusion status based on the signal intensity. We hypothesized that greater hyperintensity represents more severe hypoperfusion.

METHODS

Overall, 27 patients with acute occlusion of the proximal middle cerebral artery were divided into 2 groups, based on their signal intensity in the insular segment of middle cerebral artery on the affected side, relative to that of the insular cortex: the low signal intensity group (hypo- or isointense signals, n = 12) and the high signal intensity group (hyperintense signals, n = 15). Using dynamic susceptibility contrast magnetic resonance imaging, we assessed the time of the maximum value of the residue function and mean transit time, in the entire middle cerebral artery cortical area and diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score regions, including the corona radiata.

RESULTS

The high signal intensity group had significantly longer time of the maximum value of the residue function in all the diffusion-weighted imaging-Alberta Stroke Program Early Computed Tomography Score regions, except the M3 and M6 regions, and significantly longer mean transit time in the M1 and M4 regions.

CONCLUSIONS

Quantitative analysis of the perfusion parameters revealed more severely compromised and widely disturbed perfusion status in the high signal intensity group than in the low signal intensity group.

Better continuity of the facial nerve demonstrated in the temporal bone on three-dimensional T1-weighted imaging with volume isotropic turbo spin echo acquisition than that with fast field echo at 3.0 tesla MRI

INTRODUCTION

Three-dimensional (3D) T1-weighted imaging (T1WI) is used for evaluation of the facial nerve. The signal intensity of normal and pathological facial nerves has been well evaluated at both 1.5T and 3.0T MRI after gadolinium (Gd)-enhancement with various pulse sequences. However, the continuity of the facial nerve has not been evaluated on 3D-T1WI. This study aims to compare the continuity of the normal facial nerve in the temporal bone demonstrated on T1-weighted volume isotropic turbo spin echo acquisition (T1-VISTA), which is a spin-echo sequence, to that on T1-weighted fast field echo (T1-FFE), which is a gradient-echo sequence, at 3.0T MRI.

METHODS

Forty-four normal facial nerves in 22 healthy volunteers were imaged with both sequences using 3.0T MRI without Gd-enhancement. The facial nerves were evaluated visually by two neuroradiologists in four anatomical segments with a 3-point grading system of continuity. The continuity was assessed by summing the grades of the four segments as a total score. The grades at each segment and the total scores were compared statistically between the T1-VISTA and T1-FFE.

RESULTS

The grades in all segments and the total score were significantly higher with T1-VISTA than those with T1-FFE.

CONCLUSIONS

T1-VISTA was superior to demonstrate the facial nerve as a continuous anatomical structure in the temporal bone at 3.0T MRI.

Aquaporin Positron Emission Tomography Differentiates Between Grade III and IV Human Astrocytoma

BACKGROUND

Aquaporin (AQP) water channels play a significant role in mesenchymal microvascular proliferation and infiltrative growth. AQPs are highly expressed in malignant astrocytomas, and a positive correlation is observed between their expression levels and histological tumor grade.

OBJECTIVE

To examine the utility of aquaporin positron emission tomography (PET) for differentiating between astrocytoma grade III and grade IV using the AQP radioligand [¹¹C]TGN-020.

METHODS

Fifteen astrocytoma patients, grade III (n = 7) and grade IV (n = 8), and 10 healthy volunteers underwent [¹¹C]TGN-020 aquaporin PET imaging. Surgical tissues of astrocytoma patients were examined for histopathological grading using the WHO classification standard and expression of AQP1 and AQP4 immunohistochemically.

RESULTS

Mean standardized uptake values of astrocytoma grade III and IV (0.51 ± 0.11 vs 1.50 ± 0.44, respectively) were higher than normal white matter (0.17 ± 0.02, P < .001) for both tumor grades. Importantly, mean standardized uptake values of astrocytoma grade IV were significantly higher than grade III (P < .01).

CONCLUSION

Our study demonstrated that [¹¹C]TGN-020 aquaporin PET imaging differentiated between astrocytoma grades III and IV. We suggest its clinical application as a noninvasive diagnostic tool would lead to advancements in the management of these malignant brain tumors.

De Novo Pineal Region Germinoma in the Seventh Decade of Life: A Case Report

Germ cell tumors typically occur in children and adolescents. We here report a rare case of de novo pineal region germinoma in the seventh decade of life. A 62-year-old man presented with double vision. Computerized tomography and magnetic resonance imaging (MRI) identified a heterogeneously enhanced tumor with calcification in the pineal region with ventricular dilatation due to aqueduct stenosis. The tumor had not been observed at all on MRI obtained 2 years previously. The patient underwent endoscopic biopsy and third ventriculostomy for the obstructive hydrocephalus. The tumor was histopathologically diagnosed as a pure germinoma. The patient underwent radiomonotherapy, resulting in his complete remission, which was confirmed by a series of follow-up MRI studies and hematological examinations. Intracranial germinoma should be considered in the differential diagnosis of pineal region tumors regardless of age, even though the tumor was undetectable on the previous neuroimaging.

Malignant Hyperthermia and Cerebral Venous Sinus Thrombosis After Ventriculoperitoneal Shunt in Infant with Schizencephaly and COL4A1 Mutation

BACKGROUND

Schizencephaly is a rare congenital central nervous system malformation characterized by linear, thickened clefts of the cerebral mantle. Recently, germline mutations in collagen type IV alpha 1 (COL4A1) have been reported to be a genetic cause of schizencephaly as a result of prenatal stroke. Patients with COL4A1 mutation demonstrate a variety of disease phenotypes. However, little is known about the potential complications of patients with COL4A1 mutations before and after neurologic surgery.

CASE DESCRIPTION

A 9-month-old boy with schizencephaly and a congenital cataract underwent a ventriculoperitoneal shunt for progressive hydrocephalus. Postoperatively, he developed malignant hyperthermia and cerebral venous thrombosis. Early treatment with dantrolene sodium and hydration was effective. Genetic testing revealed a germline COL4A1 mutation.

CONCLUSIONS

To our knowledge, malignant hyperthermia and cerebral venous thrombosis have not been reported in the literature in patients with COL4A1 mutations after surgery. Schizencephaly arising from COL4A1 mutations might be a disease prone to these adverse effects because this mutation is known to be associated with venous tortuosity, venous vulnerability, and muscle spasms due to basement membrane protein abnormalities. We need to better understand the wide spectrum of clinical phenotypes of COL4A1 mutations and potential complications in order to better manage surgery of patients with schizencephaly.

EGFRvIII Is Expressed in Cellular Areas of Tumor in a Subset of Glioblastoma

Epidermal growth factor receptor variant III (EGFRvIII) is a tumor-specific cell surface antigen often expressed in glioblastoma and has drawn much attention as a possible therapeutic target. We performed immunohistochemistry on histology sections of surgical specimens taken from 67 cases with glioblastoma, isocitrate dehydrogenase-wild type, and evaluated the morphological characteristics and distribution of the EGFRvIII-positive tumor cells. We then evaluated the localization of EGFRvIII-expression within the tumor and peritumoral areas. EGFRvIII immunopositivity was detected in 15 specimens taken from 13 patients, including two recurrent specimens taken from the same patient at relapse. Immunofluorescence staining demonstrated that EGFRvIII-positive cells were present in cells positive for glial fibrillary acidic protein (GFAP), and some showed astrocytic differentiation with multiple fine processes and others did not shown. The EGFRvIII-positive cells were located in cellular areas of the tumor, but not in the invading zone. In the two recurrent cases, EGFRvIII-positive cells were markedly decreased in one case and retained in the other. With regard to overall survival, univariate analysis indicated that EGFRvIII-expression in patients with glioblastoma was not significantly associated with a favorable outcome. Double-labeling immunofluorescence staining of EGFRvIII and GFAP showed that processes of large, well differentiated, GFAP-positive glia extend to and surround less differentiated, EGFRvIII-positive glial cells in cellular areas of tumor. However, in the tumor periphery, EGFRvIII-positive tumor cells were not observed. This finding suggests that EGFRvIII is involved in tumor proliferation, but that invading glioma cells lose their EGFRvIII expression.

[A Case of Subdural Empyema with Cerebral Arteritis and Brain Ischemia in the Middle Cerebral Artery Distribution, Secondary to Odontogenic Maxillary Sinusitis]

We present a rare case of subdural empyema with cerebral arteritis and brain ischemia in the middle cerebral artery distribution secondary to odontogenic maxillary sinusitis. A 32-year-old man was admitted to our hospital because of high fever and generalized convulsions. Computed tomography(CT)and magnetic resonance imaging(MRI)showed subdural empyema at the left convexity, with a small amount of air. An interruption of the right maxillary sinus floor corresponding to the alveolar process was evident on coronal CT. He was diagnosed as having subdural empyema caused by odontogenic maxillary sinusitis. MR angiography showed stenosis of the left middle cerebral artery(MCA). Despite antibiotic administration, he became drowsy and developed aphasia with right hemiparesis. Repeat MRI showed enlargement of the encapsulated subdural empyema with increased midline shift to the right. We performed prompt surgical evacuation with craniotomy, endoscopic drainage of the sinusitis, and tooth extraction. A hyperintense lesion was observed on subsequent diffusion-weighted imaging in the left MCA distribution. After repeat drainage of the re-enlarged subdural empyema, he was discharged without apparent neurological deficits. This case indicates that subdural empyema from odontogenic sinusitis requires a suitable imaging study of the brain, head, and neck region, and a multidisciplinary approach involving a neurosurgeon, otolaryngologist, and oral surgeon. Prompt initiation of appropriate antibiotic therapy with surgical intervention is recommended for treatment of subdural empyema from odontogenic sinusitis.

Multiple aneurysms on the subarcuate artery arising from the anterior inferior cerebellar artery in a patient with a Borden type I transverse-sigmoid dural arteriovenous fistula manifesting as subarachnoid hemorrhage: A case report

BACKGROUND

Peripheral anterior inferior cerebellar artery (AICA) aneurysms are rare and commonly associated with vascular malformations, such as cerebellar arteriovenous malformations (AVMs). We present a case wherein multiple AICA feeding aneurysms on the subarcuate artery as a feeding artery of a Borden type I transverse-sigmoid dural arteriovenous fistula (dAVF) manifested as subarachnoid hemorrhage.

CASE DESCRIPTION

A 67-year-old woman presented with acute severe headache. Brain computed tomography (CT) demonstrated subarachnoid hemorrhage mainly in the posterior fossa. A transverse-sigmoid dAVF was detected on magnetic resonance angiography (MRA) and three-dimensional-CT angiography (3D-CTA), with no cortical venous reflex. The patient underwent conventional angiography, which showed multiple aneurysms on a small branch of the AICA, feeding a transverse-sigmoid dAVF (Borden type I). The AICA aneurysms seemed flow dependent and ruptured owing to high-flow arteriovenous shunts through the dAVF. Based on the source images of the MRA, the small artery arising from the AICA was considered the subarcuate artery, and it was confirmed on 3D-CTA after the artery was successfully embolized with Onyx without any complications. Multiple aneurysms on the subarcuate artery are extremely rare, and the artery has not been identified as a feeding artery of the transverse-sigmoid dAVF.

CONCLUSION

A rare case of multiple ruptured aneurysms on the subarcuate artery was reported in a patient with a Borden type I dAVF at the transverse-sigmoid sinuses manifesting as subarachnoid hemorrhage. Onyx embolization of the parent artery occlusion was feasible and useful in treating this type of feeding artery aneurysm of the AICA with a dAVF.

Transcription factor EB influences invasion and migration in oral squamous cell carcinomas

OBJECTIVE

Transcription factor EB (TFEB) is a master regulator of lysosomal biogenesis and plays an important role in various cancers. However, the function of TFEB in oral squamous cell carcinomas has not been examined. The aim of this study was to elucidate the role of TFEB in oral squamous cell carcinomas.

MATERIALS AND METHODS

Expression levels of TFEB were examined in six different human oral squamous carcinoma cells: HSC2, HSC3, HSC4, SAS, OSC20, and SCC25. Knockdown of TFEB using small interfering RNA in HSC2 and HSC4 cells was performed. Cell morphology was observed by immunofluorescence microscopy. Cell proliferation, invasion, and adhesion were analyzed.

RESULTS

Expression levels of TFEB were high in HSC2, moderate in HSC4 and SCC25, and low in HSC3 and OSC20 cells. Knockdown of TFEB did not affect proliferation of HSC2 and HSC4 cells, but did induced enlargement of lysosomes and endosomes in HSC4 cells. TFEB silencing reduced invasion and migration of these HSC cell squamous carcinoma cells; however, increased cell adhesion was also observed.

CONCLUSION

TFEB knockdown reduces invasion and migration of cancer cells, likely through lysosomal regulation. Taken together, TFEB influences cell invasion and migration of oral squamous cell carcinomas.

Band-Suppressed Restoration of X-Ray Images Blurred by Body Movement

The restoration of X-ray images that have been blurred due to body movement are discussed. The observation system for these images is described using a mathematical model, and several restoration filters composed of a series of such models are proposed. These filters restore band-suppressed approximations of the original images. In addition, redundancy is introduced into these restoration filters in order to suppress additive noise. These filters are expanded to be applicable not only to parallel translations, but also to rotations by coordinate transformation. The proposed methods are applied to blurred X-ray images of a bone model of the elbow joint. The parameters of the restoration filter are estimated using a marker attached to the subject as a reference signal.