Poor removal of tedizolid during continuous hemodiafiltration: experiments using an in vitro continuous hemodiafiltration model.

BACKGROUND: Tedizolid is an oxazolidinone anti-MRSA drug with included in the National Health Insurance Drug Price List in 2018. The effect of hemodialysis on tedizolid phosphate concentrations has been reported; pre-dialysis concentrations decreased by 10% compared to post- dialysis concentrations. However, the material of the dialysis membrane remains unknown. In addition, there have been no reports on the effects of continuous hemodiafiltration. In this study, we investigated the effects of continuous hemodiafiltration on tedizolid using two types of dialysis membranes made of different materials. METHODS: The adsorption of tedizolid, linezolid, and vancomycin to two different dialysis membranes was investigated, and the clearance of each drug was calculated by experiments using an in vitro continuous hemodiafiltration model. RESULTS: The adsorption of tedizolid, linezolid, and vancomycin on the dialysis membranes was examined, and no adsorption was observed. Experimental results from the continuous hemodiafiltration model showed that linezolid and vancomycin concentrations decreased over time: after two hours, the respective decreases were 26.48 ± 7.14% and 28.51 ± 2.32% for polysulfone membranes, respectively. The decrease was 23.57 ± 4.95% and 28.73 ± 5.13% for the polymethylmethacrylate membranes, respectively. These results suggested that linezolid and vancomycin were eliminated by continuous hemodiafiltration. In contrast, tedizolid phosphate and tedizolid concentrations decreased slightly in the polysulfone and polymethylmethacrylate membranes. The decrease in concentrations were 2.10 ± 0.77% and 2.97 ± 0.60% for the polysulfone membranes, respectively. For the polymethylmethacrylate membranes, the decrease in concentration were 2.01 ± 0.88% and 1.73 ± 0.27%, respectively. CONCLUSION: These results suggested that tedizolid should not be considered for dose control during continuous hemodiafiltration.

A rare case of glial fibrillary acidic protein astrocytopathy that resolved spontaneously within a self-limited course.

Glial fibrillary acidic protein astrocytopathy is a form of autoimmune meningoencephalomyelitis. The presence of antibodies in spinal fluid against glial fibrillary acidic protein is necessary to diagnose the disease. There is no standard treatment and few cases of glial fibrillary acidic protein astrocytopathy have been reported. A 31-year-old healthy Japanese man presented to our emergency department with a 7-day history of fever and headache. He was in good general condition, without abnormalities on physical examination, and a general hematological examination revealed hyponatremia (130 mEq/L). Five days later, he was followed up and new subjective symptoms were noted: tremor in the right hand, constipation, sweating, and lightheadedness. Cerebrospinal fluid examination revealed a cell count of 57/µL (96 % mononuclear cells, 4 % multinuclear cells), elevated protein level (103 mg/dL), elevated adenosine deaminase level (15.0 U/L), negative polymerase chain reaction test results for herpes simplex virus and Mycobacterium tuberculosis, negative cerebrospinal fluid culture, and negative cerebrospinal fluid anti-acid bacteria culture, indicating aseptic meningitis. T1-weighted contrast-enhanced magnetic resonance imaging of the head showed a linear contrast effect perpendicular to the lateral ventricular wall and along the perivascular vessels spreading radially. Based on the presence of hyponatremia, history of movement disorder and autonomic symptoms, high adenosine deaminase level in cerebrospinal fluid, and findings on contrast-enhanced magnetic resonance imaging of the head, we suspected glial fibrillary acidic protein astrocytopathy and assessed anti-glial fibrillary acidic proteinαantibody in cerebrospinal fluid, which was positive, and diagnosed glial fibrillary acidic protein astrocytopathy. After careful follow-up with symptomatic treatment without immunosuppressive therapy, the fever, headache, tremor, and autonomic symptoms were improved over time. Contrast-enhanced magnetic resonance imaging of the head and findings of cerebrospinal fluid also showed improvement. glial fibrillary acidic protein astrocytopathy should be a differential diagnosis in patients with aseptic meningitis with movement disorders or autonomic symptoms and elevated cerebrospinal fluid adenosine deaminase. Careful follow-up without immunosuppressive treatment should be considered for patients with minimal neurologic symptoms as glial fibrillary acidic protein astrocytopathy may have a self-limiting course and resolve.

Two case reports of two interventional radiology techniques for the treatment of stage II empyema: Hydrodissection and guidewire-dissection.

Empyema is an infection of the pleural space that is classified into 3 stages. Video-assisted thoracoscopic surgery is recommended as the first-line approach for stage II acute empyema. The purpose of video-assisted thoracoscopic surgery is also achieved with hydrodissection and guidewire-dissection by breaking the septa mechanically in the pleural cavity. Hydrodissection and guidewire-dissection are techniques in which a contrast medium is administered at high pressure and a guidewire is inserted into the pleural cavity to break the septa, respectively. Hydrodissection and guidewire-dissection might be minimally invasive alternatives for the treatment of septated empyema.

Evaluation of Posterior Ligamentous Complex Injury in Thoracolumbar Burst Fractures: Correlation Analysis of CT and MRI Findings.

The goal of this study is to perform correlation analysis of Computed tomography (CT) and magnetic resonance imaging (MRI) results in posterior ligament complex (PLC) injury and define the morphological traits of thoracolumbar (TL) burst fractures connected to PLC injury. Forty patients with surgically repaired TL burst fractures between January 2013 and December 2020 were retrospectively analyzed. The patients were split into two groups for comparison based on MRI (Group P: patients with a confirmed or suspected PLC injury; Group N: patients with PLC injury denied). The radiographic morphological examination based on CT scans and clinical evaluation was performed and compared between two groups. The thoracolumbar injury classification and severity score (TLICS), the load sharing classification (LSC) scores, and the number of patients with neurological impairments were considerably greater in Group P. Loss of height of the fracture (loss height), local kyphosis of the fracture (local kyphosis), and supraspinous distance were significantly higher in Group P and significantly associated with PLC injuries indicating severe vertebral body destruction and traumatic kyphosis in multivariate logistic analysis [odds ratio: 1.90, 1.06, and 1.13, respectively]. Cutoff value for local kyphosis obtained from the receiver operating characteristic curve was 18.8. If local kyphosis is greater than 18.8 degrees on CT scans, we should take into account the probability of the highly damaged burst fracture associated with PLC injury. In this situation, we should carefully assess MRI to identify the spinal cord injury or spinal cord compression in addition to PLC injury because these instances likely present with neurological abnormalities.

Use of intravascular hypo- and hyper-attenuation on non-contrast-enhanced computed tomography in diagnosing acute septic thrombophlebitis.

Septic thrombi, such as those observed in pylephlebitis and Lemierre's syndrome, are characterized by portal vein thrombosis and venous thrombosis with bacterial infection. Although radiographic findings of septic thrombus on contrast-enhanced computed tomography have been well described, no report has described the characteristics of non-contrast-enhanced computed tomography. We describe a case series of septic thrombophlebitis exhibiting intravascular hypo- and hyper-attenuation on non-contrast-enhanced computed tomography. These radiographic features reflect the pathophysiology of septic thrombus, and therefore, it is important and useful to evaluate thrombus attenuation on non-contrast-enhanced computed tomography.

Radiological Analysis of Minimally Invasive Microscopic Laminectomy for Lumbar Canal Stenosis with a Focus on Multilevel Stenosis and Spondylolisthesis.

OBJECTIVE: We retrospectively compared the radiological and clinical outcomes of two different surgical techniques (lumbar spinous process splitting laminectomy [LSPSL] and unilateral laminotomy for bilateral decompression [ULBD]) to treat lumbar spinal canal stenosis (LCS). METHODS: We performed a retrospective comparative study of 141 consecutive patients with an average age of 70.8 ± 9.4 years who had undergone LSPSL or ULBD for LCS between April 2015 and April 2019. None of the patients had developed remote fractures of the spinous processes using either technique. These cases were divided into 2 groups: group L, 73 patients who had undergone LSPSL from April 2015 to April 2017; and group U, 68 patients who had undergone ULBD from May 2017 to April 2019. The clinical and radiological outcomes and surgical complications at the 1-year postoperative follow-up period were evaluated. RESULTS: We found no significant differences in the operative time between the 2 groups. However, group U had had significantly less blood loss than group L. The facet joints were significantly well preserved in group U. We examined the multilevel and spondylolisthesis cases separately and found that both surgical procedures were equally effective and that the visual analog scale scores for back or leg pain and Japanese Orthopaedic Association scores had significantly improved postoperatively in each group. Group U showed better outcomes in terms of LCS recurrence, with 3 patients in the group L requiring repeat surgery. CONCLUSIONS: We found both ULBD and LSPSL to be safe and effective techniques for LCS, even for patients with spondylolisthesis and multilevel disease. ULBD was superior in terms of recurrence prevention, preservation of the facet joints, and less blood loss.

Treating Low-Grade Myxofibrosarcoma With Stereotactic Body Radiation Therapy Using CyberKnife®.

Myxofibrosarcoma (MFS) is one of the most common soft tissue sarcomas. Low-grade MFS has a high local recurrence rate, similar to that of high-grade MFS. Hence, appropriate adjuvant therapy is required to control low-grade MFS. In this report, we present a case in which recurrent low-grade MFS was successfully treated with stereotactic body radiation therapy (SBRT) using CyberKnife® (CK) (Accuray Incorporated, Sunnyvale, CA). A 76-year-old man underwent SBRT using CK for recurrent low-grade MFS in the right posterior chest wall after undergoing resection and skin grafting four and three times, respectively. We planned CK treatment separately for each in two parts. For the lesion on the scapula side, the target volume was 109 cm3 and the total prescribed dose was 34.6 Gy, while the lesion on the spinal side had a target volume of 72 cm3 and a total prescribed dose of 36 Gy, both in five fractions. Each SBRT was performed on alternate days in a span of 14 days. The tumors gradually reduced in size with tolerable levels of toxicity. SBRT using CK could be a safe and effective adjuvant therapy for low-grade MFS.

Intracardiac platypnea-orthodeoxia syndrome diagnosed by forward-bending and abdominal compression.

Intracardiac platypnea-orthodeoxia syndrome (POS) is a pathological condition that leads to a reduction in oxygenation in the sitting position. The detection rate of patent foramen ovale that causes POS increases with Valsalva manoeuvre and cough. We report the case of a 92-year-old woman with POS, which could not be diagnosed in the sitting position. The Valsalva manoeuvre could not be performed because of dementia, and POS was diagnosed on the forward-bending position and abdominal compression. It was assumed that forward-bending increases the right atrial pressure by compressing the right ventricle along with elongation of the aorta, and abdominal compression increases the shunt volume by increasing the venous return. If POS is suspected in patients with dementia which cannot be diagnosed in the sitting position, forward-bending and abdominal compression, instead of the Valsalva manoeuvre, might be useful.

Preoperative Intracranial Dissemination of Spinal Myxopapillary Ependymoma Attributed to Tumor Hemorrhage.

BACKGROUND: Spinal myxopapillary ependymoma (SME), generally considered a benign entity, can exhibit brain and whole-spine metastases as well as local recurrence after surgery. However, the presence of preoperative retrograde intracranial dissemination at the time of diagnosis is very rare. CASE DESCRIPTION: We report a case of SME in a 22-year-old man who presented with acute exacerbation of chronic back pain shooting down both thighs and weakness in both legs. Magnetic resonance imaging of the brain and whole spine showed an enhancing mass occupying the majority of the spinal canal at the L1-L2 level and multiple foci dissemination, including in the right pons, lateral midbrain, and occipital lobe, and at the C7, Th6, L4, and S2 levels of the spinal canal at the time of diagnosis. On gross total removal of the dominant tumor located at the L1-L2 level, severe intradural arachnoiditis and syrinx filled with xanthochromic cerebrospinal fluid was noted, indicating the presence of previous tumor hemorrhage. Histopathologic analysis of the tumor supported SME diagnosis, and <1% of cells showed Ki-67 expression. We speculated that distant retrograde dissemination could have been attributed to metastatic spread through cerebrospinal fluid caused by tumor hemorrhage, which may explain distant dissemination despite low expression of Ki-67. CONCLUSIONS: Screening of the whole brain and spine at the time of diagnosis is imperative when tumor is detected at any level of the neuraxis. The present case of SME with a preoperative intracranial lesion is the fifth case documented in the medical literature.

Clinical and Radiological Clues of Traumatic Craniocervical Junction Injuries Requiring Occipitocervical Fusion to Early Diagnosis.

OBJECTIVE: The purpose of this study is to find the clinical and radiographic characteristics of traumatic craniocervical junction (CCJ) injuries requiring occipitocervical fusion (OC fusion) for early diagnosis and surgical intervention. METHODS: We retrospectively reviewed 12 patients with CCJ injuries presenting to St. Michaels Hospital in Toronto who underwent OC fusion and looked into the following variables; (1) initial trauma data on emergency room arrival, (2) associated injuries, (3) imaging characteristics of computed tomography (CT) scan and magnetic resonance imaging (MRI), (4) surgical procedures, surgical complications, and neurological outcome. RESULTS: All patients were treated as acute spinal injuries and underwent OC fusion on an emergency basis. Patients consisted of 10 males and 2 females with an average age of 47 years (range, 18-82 years). All patients sustained high-energy injuries. Three patients out of 6 patients with normal BAI (basion-axial interval) and BDI (basion-dens interval) values showed visible CCJ injuries on CT scans. However, the remaining 3 patients had no clear evidence of occipitoatlantal instability on CT scans. MRI clearly described several findings indicating occipitoatlantal instability. The 8 patients with normal values of ADI (atlantodens interval interval) demonstrated atlantoaxial instability on CT scan, however, all MRI more clearly and reliably demonstrated C1/2 facet injury and/or cruciate ligament injury. CONCLUSION: We advocate measures to help recognize CCJ injury at an early stage in the present study. Occipitoatlantal instability needs to be carefully investigated on MRI in addition to CT scan with special attention to facet joint and ligament integrity.

Intraosseous Melanotic Schwannoma in the Sacrum Mimicking Primary Bone Tumor.

Primary tumors of sacrum are rarely seen, and the differential diagnosis is extensive, such as chordomas, giant cell tumors, and schwannomas. Sacral intraosseous schwannomas (IOSs) are very rare and encompass approximately 1%-5% of all spinal schwannomas. Melanotic schwannomas (MSs) are categorized as an unusual variant of benign schwannomas; however, they sometimes follow a malignant course. The authors present a case of MS with intraosseous extension into sacrum in a 48-year-old male arising from the left S2 nerve root. Magnetic resonance imaging (MRI) and computed tomography (CT) scan demonstrated a destructive mass in the sacrum. He was made a diagnosis with MS by 18F-fluoro-deoxy-glucose positron-emission-tomography (18F-FDG PET) and open biopsy. The tumor was blackish-colored and vascular-rich fragile tumor covered by fibrous capsule. The floor of the tumor was not encapsulated and invading into the sacral bone. Total removal of the tumor together with the left S2 nerve of origin via posterior approach was achieved. The patient made dramatic recovery of neurological symptoms and tumor recurrence is not seen for 6-month follow-up period. MS is a benign tumor with potential for aggressive behavior and capacity to metastasize. Therefore, total removal of the tumor and careful postoperative follow-up are recommended. Postoperative spinopelvic stability also needs to be taken into consideration. The authors discuss our successful management with a focus on diagnostic process, surgical planning, and histological consideration to provide the most up-to-date guidance on managing this challenging tumor.

Vertebral fracture with muscle hematoma mimicking abscess.

Vertebral fracture with muscle hematoma is occasionally seen in practice. However, air-containing hematoma mimicking abscess has not been reported. We present an 87-year-old man with back pain after a fall. Computed tomography scan demonstrated vertebral fracture of L1 and low-density lesions with air bubble in the left crus of the diaphragm and left psoas muscle that were verified to be muscle hematoma. Muscle hematoma due to vertebral fracture can present radiological findings similar to an abscess. A characteristic "vertebral body cleft continuity sign" might be useful for differentiating between hematoma and abscess.

Flat Posterior Cranial Fossa Affects Outcomes of Microvascular Decompression for Trigeminal Neuralgia.

OBJECTIVE: To investigate the prognostic factors for microvascular decompression (MVD) in patients with primary trigeminal neuralgia (TN), with a particular focus on the morphology of the posterior cranial fossa (PCF). METHODS: The present study investigated 126 surgically treated patients with primary TN with more than 1-year follow-up who underwent high-resolution magnetic resonance imaging between April 2003 and September 2015. We retrospectively reviewed clinical information and operative findings. Outcomes of MVD were also evaluated and patients were classified into "success" and "failure" groups. Furthermore, length, width, and height of the PCF were measured by approximation to an ellipsoid with reference to the anterior commissure-posterior commissure line. These values were compared between groups. RESULTS: Atypical type 2 TN (P < 0.001) and weak neurovascular compression (P < 0.001) correlated significantly with poor outcomes of MVD for primary TN. In terms of PCF morphology, the failure group showed a flatter PCF than the success group, whereas sex, age, affected side, topography of facial pain, interval between onset and surgery, responsible vessel, location of compression along the nerve, and site of compression around the circumference of the nerve root did not significantly affect outcomes of MVD for primary TN. CONCLUSIONS: The present study identified type 2 TN, weak neurovascular compression, and flatness of the PCF as predictors of poor prognosis after MVD for primary TN.

Chiari Type 1 Malformation-induced Intracranial Hypertension with Diffuse Brain Edema Treated with Foramen Magnum Decompression: A Case Report.

Chiari type 1 malformation (CM1) rarely causes papilloedema, which is indicative of high intracranial pressure with or without ventricular dilatation. Furthermore, concomitant brain parenchymal abnormalities have not been reported to date. In this paper, the authors report on a young woman of CM1-induced intracranial hypertension (ICH) with diffuse brain edema with a focus on venous sinus assessment, and discuss the surgical strategy. A 24-year-old woman presented to Nagoya University Hospital complaining of 4-year history of severe occipital headache and blurry vision with slowly progressive worsening. Head and whole spine MRI showed a CM1 with diffuse white matter hyperintensities (WMH) on T2-weighted imaging and narrowed brain sulci without hydrocephalus. Lumbar puncture revealed extremely high opening pressure. Detailed blood examination and other radiographical imaging studies denied the presence of tumor, collagen disease, encephalitis and other entities. Head magnetic resonance venography and angiography demonstrated severe transverse sinus stenosis on both sides. Foramen magnum decompression was performed to alleviate the ICH by restoration of cerebrospinal fluid (CSF) stagnation at the foramen magnum with successful outcome. The patient completely recovered from preoperative symptoms immediately after surgery. The diffuse WMH and narrowing brain sulci have been resolving. The most feasible explanation for this complicated pathophysiology was ICH induced by CM1 led to transverse sinus collapse, resulting in diffuse WMH as a result of venous hypertension. This case report is the first illustration of successful surgical treatment of CM1 with diffuse brain edema with a focus on venous sinus assessment.

Functional Properties of Mouse Chitotriosidase Expressed in the Periplasmic Space of Escherichia coli.

Chitotriosidase (Chit1) is an enzyme associated with various diseases, including Gaucher disease, chronic obstructive pulmonary disease, Alzheimer disease and cystic fibrosis. In this study, we first expressed mouse mature Chit1 fused with V5 and (His)6 tags at the C-terminus (Chit1-V5-His) in the cytoplasm of Escherichia coli and found that most of the expressed protein was insoluble. In contrast, Chit1 tagged with Protein A at the N-terminus and V5-His at the C-terminus, was expressed in the periplasmic space of E. coli as a soluble protein and successfully purified. We evaluated the chitinolytic properties of the recombinant enzyme using 4-nitrophenyl N,N'-diacetyl-ß-D-chitobioside [4NP-chitobioside, 4NP-(GlcNAc)2] and found that its activity was comparable to CHO cells-expressed Chit1-V5-His. Optimal conditions for the E. coli-produced Chit1 were pH ~5.0 at 50°C. Chit1 was stable after 1 h incubation at pH 5.0~11.0 on ice and its chitinolytic activity was lost at pH 2.0, although the affinity to chitin remained unchanged. Chit1 efficiently cleaved crystalline and colloidal chitin substrates as well as oligomers of N-acetyl-D-glucosamine (GlcNAc) releasing primarily (GlcNAc)2 fragments at pH 5.0. On the other hand, (GlcNAc)3 was relatively resistant to digestion by Chit1. The degradation of 4NP-(GlcNAc)2 and (GlcNAc)3 was less evident at pH 7.0~8.0, while (GlcNAc)2 production from colloidal chitin and (GlcNAc)6 at these pH conditions remained strong at the neutral conditions. Our results indicate that Chit1 degrades chitin substrates under physiological conditions and suggest its important pathophysiological roles in vivo.

Sonographic Optic Nerve Sheath Diameter: A Simple and Rapid Tool to Assess the Neurologic Prognosis After Cardiac Arrest.

BACKGROUND AND PURPOSE: The early prediction of hypoxic encephalopathy after cardiac arrest is challenging. Measurement of the optic nerve sheath diameter (ONSD) by using sonography is a straightforward, noninvasive technique to detect an increased intracranial pressure, which can even be conducted at the bedside. However, it remains unknown whether or not sonographic ONSD measurement is valuable as a prognostic indicator of hypoxic encephalopathy. METHODS: Seventeen patients after cardiac arrest were retrospectively enrolled in this study. ONSD measurements 3 mm behind the papilla were recorded. A Glasgow Outcome Scale score of 4 or above was considered to indicate a favorable prognosis. RESULTS: The mean ONSD associated with a favorable prognosis was 5.0 mm (4.4-6.1 mm). The ONSD associated with a poor prognosis was 6.1 mm (5.4-7.2 mm). ONSD less than or equal to 5.4 mm was an indicator of a favorable prognosis, with a sensitivity of 83%, specificity of 73%, positive likelihood ratio of 3.1, and negative likelihood ratio of .23. CONCLUSIONS: Sonographic ONSD measurement is a simple, rapid technique to assess the neurological prognosis after cardiac arrest.