Long-term recurrence after surgery for schwannoma of the cauda equina

Background:

Cauda equina tumors are rare primary spinal tumors. Histologically, the most common tumor arising from the cauda equina is a schwannoma. However, little is known about the long-term postoperative outcomes of cauda equina schwannoma. Here, we reviewed the median-to-long-term postoperative outcomes of eight of our own patients with schwannomas of the cauda equina.

Methods:

Between 2007 and 2020, we, retrospectively, reviewed eight patients with cauda equina schwannomas (CESs) undergoing nine operations at our institution. There were five males and three females averaging 56.5 years of age who were followed for over 40 postoperative months. The study included assessment of the following variables: the modified McCormick scale, tumor size, location, extent of resection, treatment of the tumor involving nerve roots, and postoperative observational follow-up.

Results:

Gross-total resection was achieved in all eight patients; none received adjuvant therapy. The involved nerve roots were completely sacrificed in seven patients and partially resected in one. During a median follow-up of 108 months, only one patient sustained a tumor recurrence 164 months following the index surgery.

Conclusion:

CESs may recur more than 10 years after the original surgery. Radical resection of the tumor, including complete removal of the involved nerve root during the index surgery, and long-term postoperative follow-up is, therefore, essential.

Endovascular Treatment Strategy for Acute Basilar Artery Occlusion with Unexpected Right-Sided Aortic Arch

A right-sided aortic arch (RAA) is a rare variant of the aortic arch found. We present a case of endovascular treatment (EVT) for acute basilar artery (BA) occlusion with an RAA. A 70-year-old man developed acute ischemic stroke due to BA occlusion. During urgent EVT for BA occlusion with an RAA, which was observed unexpectedly, navigation of the catheter to the target vessel was achieved as a result of an early change in the access route. Flexible treatment strategies are warranted for cases of unexpected anatomical variant in the fight against time for emergent cases, such as acute ischemic stroke.

Gamma knife radiosurgery cured hydrocephalus in non-hemorrhagic brain stem arteriovenous malformation

A 13-year-old boy, with a history of intermittent headache and transient diplopia, was found to have non-hemorrhagic cerebral arteriovenous malformation in the midbrain tegmental region associated with hydrocephalus. Gamma knife radiosurgery was performed at 16 Gy with 75% marginal dose. Posttreatment course was uneventful. Follow-up MR imaging at one year after the treatment revealed complete disappearance of the abnormal vascular flow voids. The size of each ventricle at the treatment and at one year after treatment were as follows; 60.2 cc and 20.9 cc in the lateral ventricles, 3.7 cc and 2.7 cc in the third ventricle. The hydrocephalus might be caused by obstructive mechanism but mostly by high venous pressure due to the shunt blood flow. The goal of treatment for hydrocephalus should be nidus obstruction and normalizing the vascular flow.

Impact of visit-to-visit variability in blood pressure on coronary plaque as assessed by integrated backscatter intravascular ultrasound

Introduction

Visit-to-visit variability (VVV) in blood pressure (BP) has been reported to be a strong predictor of cardiovascular disease. However, the association of VVV in BP and coronary plaque composition has not been fully elucidated.

Purpose

The aim of this study was to examine the relationship between VVV in BP and the tissue characteristics of coronary plaques as assessed by integrated backscatter (IB) intravascular ultrasound (IVUS) in patients with coronary artery disease (CAD).

Methods

One hundred-two consecutive patients with CAD who underwent percutaneous coronary intervention (PCI) using IVUS, and who had at least six clinic visits a year before PCI were included. We measured systolic and diastolic BP (SBP and DBP) at each visit and determined VVV in BP expressed as the standard deviation of the average BP. Gray-scale and IB IVUS examinations were performed for the culprit lesion of a coronary artery just before PCI.

Results

There were no significant associations between the average SBP or DBP and various IVUS parameters. However, VVV in SBP was positively correlated with both the percentage of atheroma volume (PAV) (r=0.227, p=0.023) and percentage of lipid volume (PLV) (r=0.532, p<0.001). VVV in DBP was positively correlated with PLV (r=0.243, p=0.014), while there was no significant correlation between VVV in DBP and PAV. A multiple regression analysis showed that VVV in SBP was independently associated with PAV (p=0.036) and PLV (p<0.001).

Conclusions

Larger VVV in SBP was significantly associated with an increased plaque burden and lipid composition at the culprit lesion of a coronary artery in CAD patients. The improvement of VVV in SBP may contribute to the regression and stabilization of coronary plaques.

Figure 1

Funding Acknowledgement

Type of funding source: None

Different clinical features between left atrial and left atrial appendage thrombus: an insight into more than 16,000 transesophageal echography database

Background

Thrombosis localization inside the left atrium (LA) is very frequently in the left atrial appendage (LAA). Some cases show atrial thrombus outside LAA, whose characteristics have not well elucidated.

Purpose

To reveal the different clinical background between thrombus inside LAA and outside LAA in a large transesophageal echo (TEE) database.

Methods

We searched the TEE database over 8 years of our center to identify patients in whom LA thrombus was pointed out. After initial TEE imaging, LA thrombus was confirmed with repeated TEE by echocardiography specialist or other modality, such as CT images.

Results

In a consecutive 16,142 TEE cases, LA thrombus was suspected in 162 cases (1%), finally 38 cases were identified as LA thrombus. They were divided into two groups; LAA only group and outside LAA group. Atrial fibrillation was concomitant in 34 patients (89%). History of stroke was significantly higher in LAA group (46.2% vs 8.3%, p=0.03) and malignant tumor was significantly higher in outside LAA group (23.1% vs 58.3%, p=0.035). LA thrombus was the first symptom in 3 cases of outside LAA group, following by malignant tumor was newly detected. Oral anticoagulation was prescribed in 23 cases (61%) at TEE study, mostly treated with warfarin, and median 123 days later thrombus dissolution was confirmed in 21 cases (55%). During mean follow up of 893 days, 4 patients experienced ischemic stroke, but two of them were due to self-interruption.

Conclusion

Outside LAA thrombus is minor but more concomitant with malignant tumor. Physician must be aware that screening of cancer is important if outside LAA thrombus is detected.

Funding Acknowledgement

Type of funding source: None

[Sellar and Parasellar Inflammatory Lesions with Impaired Visual Function:Clinical Features and Endoscopic Surgical Outcomes of Six Cases]

Accurate diagnosis and treatment of sellar and parasellar inflammatory lesions is difficult. We report six patients with sellar and parasellar inflammatory lesions and impaired visual function, who underwent endonasal endoscopic surgery. These patients included one with aspergillosis, one with hypertrophic pachymeningitis, one patient with abscess, and three with idiopathic granulomatous lesions. Following surgery and medication, visual function improved in patients with aspergillosis, hypertrophic pachymeningitis, and abscess. In patients with idiopathic granulomatous inflammation, visual function improved in one out of three patients. The treatment outcome for sellar and parasellar inflammatory lesions with impaired visual function depends on the surgery as well as on the reaction to postoperative medication. In the present study, the functional prognosis of patients with idiopathic granulomatous lesions was relatively poor when compared with that of patients with other inflammatory lesions.

An Aneurysm at the Origin of a Duplicated Middle Cerebral Artery Treated by Stent-Assisted Coiling Using the "Wrapped-Candy" Low-Profile Visualized Intraluminal Support (LVIS) Technique: A Technical Case Report and Review of the Literature

BACKGROUND

Aneurysms at the origin of a duplicated middle cerebral artery (DMCA) are quite rare. Here, we report a patient with such an aneurysm successfully treated endovascularly using our novel "wrapped-candy" low-profile visualized intraluminal support (LVIS) technique.

CASE DESCRIPTION

A 44-year-old woman underwent endovascular treatment for an unruptured wide-necked aneurysm at the origin of a DMCA that incorporated the origin of the DMCA into its neck. Stent-assisted coiling was performed using our newly developed "wrapped-candy" LVIS technique. To protect the origin of the DMCA and increase the stent metal density at the neck, an LVIS blue 3.5-mm × 22-mm stent was deployed by pushing the delivery wire aggressively to transform the visible wire components of the LVIS into a shape like "wrapped candy," maximizing the strut compaction at the neck of the aneurysm. Subsequently, the aneurysm component was coiled using a jailed microcatheter. The final procedural angiography demonstrated almost complete aneurysm occlusion with DMCA preservation.

CONCLUSIONS

Stent-assisted coiling can be a feasible treatment for an unruptured, usually wide-necked, aneurysm at the origin of a DMCA. The wrapped-candy LVIS technique may be useful in more challenging morphologies such as wide-necked aneurysms that incorporate the branch origin into the aneurysm neck.

Potential energy landscape and thermodynamic transitions of coarse-grained protein models revealed by the multicanonical generalized hybrid Monte Carlo method

In the present study, thermodynamic properties of coarse-grained protein models have been studied by an extended ensemble method. Two types of protein model were analyzed; one is categorized into a fast folder and the other into a slow folder. Both models exhibit the following thermodynamic transitions: the collapse transition between random coil states and spatially compact, but non-native states and the folding transition between the collapsed states and the folded native states. Caloric curve for the fast folder shows strong statistical ensemble dependence, while almost no ensemble dependence is found for the slow folder. Microcanonical caloric curve for the fast folder exhibits S-shaped temperature dependence on the internal energy around the collapse transition which is reminiscent of the van der Waals loop observed for the first order transition; at the transition temperature, the collapsed and random coil states coexist dynamically. The corresponding microcanonical heat capacity is found to have negative region around the transition. This kind of exotic behaviors could be utilized to distinguish fast folding proteins.

Epidemiology of long-stay patients in the pediatric intensive care unit: prevalence, characteristics, resource consumption and complications

Background

The impact of pediatric intensive care unit (PICU) utilization and resource consumption among long-stay patients has not been characterized recently. This study aimed to describe the resource consumption and characteristics of long-stay patients in a PICU.

Methods

This was a single-center descriptive cohort study of 1309 patients admitted to a PICU in 2017. The main outcome was ICU length of stay (LOS). Patients were divided into prolonged LOS (PLS) and non-PLS groups if they had an LOS of ≥ 28 or < 28 days, respectively. Two groups were compared to characterize PLS.

Results

Thirty-two (2.4%) patients had a PLS and utilized 33% of PICU bed days. Factors associated with PLS with odds ratio [95% confidence interval (CI)] were being a neonate (7.8 [2.5-25.4], p = <0.001), being an infant (2.9 [1.0-9.0], p = 0.04), admission for a respiratory ailment (7.3 [1.6-44.2], p = 0.003), cardiovascular dysfunction (24.1 [4.8-152.1], p = <0.001), post-cardiac operation (8.0 [1.7-50.1], p = 0.003), post-cardiopulmonary arrest (22.8 [1.7-211.9], p = 0.01), and transfer from another facility (4.2 [1.8-10.7], p = 0.001). PLS patients developed more nosocomial infections and disproportionately received monitoring and therapeutic resources.

Conclusions

A PLS was associated with substantial PICU utilization and complication rates. Future studies should aim to alleviate both institutional and patient-related issues in the affected population harboring possible risk factors for PLS.

[A Case of Multiple Brain Lesions Associated with Hydrophilic Polymer Allergy after Coil Embolization that Showed Repeated Progression and Regression]

A 41-year-old woman underwent coil embolization for subarachnoid hemorrhage associated with a ruptured anterior cerebral artery(A1)aneurysm. Approximately 3 weeks later, MRI revealed right cerebral white matter changes with extensive edema and enhancement lesions. Even though she was asymptomatic, we suspected an allergic reaction to the hydrophilic coating polymer and initiated steroid treatment. After tapering and discontinuing the steroid treatment, follow-up MRI revealed development of white matter lesions;thus, steroid treatment was reinitiated. Progression and regression of the lesions occurred repeatedly, and she was radiologically stable at almost 1 year after coiling. We speculated that these white matter lesions were foreign body granulomas that reacted to the hydrophilic coating of the endovascular device. Overall, an allergic reaction to hydrophilic coating polymer could occur as a delayed complication after coil embolization and that progression and regression of the lesions could repeatedly occur in rare cases.

Abstract P4-02-05: Apocrine morphology and LAR molecular subtype predict prognosis of TNBC patients with residual disease after neoadjuvant chemotherapy

Background: TNBC molecular subtype classification updated by Lehmann et al. includes 4 subtypes: basal-like 1 and 2 (BL1), (BL2), mesenchymal (M), and luminal androgen receptor (LAR), and as a modifier of these subtypes, an Immunomodulatory (IM) gene expression signature. However, molecular subtypes have not been linked to morphological features of TNBC. Apocrine carcinoma has been proposed as a TNBC category that expresses androgen receptor. LAR-subtype TNBC has a poor response to neoadjuvant systemic therapy (NST). We hypothesized that defining the apocrine-featured TNBC by morphology and molecular subtype predict the prognosis of patients with residual disease after NST. Methods: We created the Pan-Pacific TNBC Consortium dataset, which contains paired samples of matched pre and post-NST TNBC tumors from 4 institutions. All patients received NST and didn't have a pathological complete response (pCR). Three pathologists examined hematoxylin and eosin-stained slides of 86 pre-NST samples and determined (1) the presence of apocrine differentiation, (2) the level of tumor-infiltrating lymphocytes (TILs), (3) the histological grade (HG), and (4) the rate of necrosis. These morphological features were compared among the subtypes. For a sample to be considered apocrine positive, apocrine differentiation had to be identified by 2 or more pathologists. Fisher's exact test was used to test the association of subtypes and morphological features. The log-rank test was used to compare disease-free survival (DFS). Results: Twelve of 24 (50%) apocrine-positive tumor samples were LAR subtype, and12 of 17 (70%) LAR-subtype tumor samples exhibited apocrine differentiation. The other subtypes showed following: BL1, 11/44 (25%); BL2, 0/7 (0%); M, 1/10 (10%); unclassified, 0/8 (0%). The median follow-up time was 22 months. In all populations, 2-year DFS rates were higher in patients with apocrine-positive tumors than in those whose tumors did not exhibit apocrine differentiation (P = .027; 2-year DFS, 85% vs 54%). The LAR subtype was also associated with lower HG, although LAR tumors had a similar prognosis to the other subtypes. In the combined analysis of subtypes and apocrine differentiation, patients with apocrine-positive LAR tumors had a higher 2-year DFS rate than did those with apocrine-negative LAR tumors (P = .044; 2-year DFS, 88% vs. 30%). However, patients with apocrine-positive BL1 tumors had no better DFS than did those with apocrine-negative BL1 tumors (P = .133). TIL levels and the presence of the IM signature were positively associated (P = .01), and apocrine differentiation positivity tended to be negatively associated with TIL level (P = .06). Neither TIL level nor IM signature was associated with survival. Conclusion: Apocrine differentiation was associated with the LAR subtype of TNBC and better prognosis in patients who did not have a pCR. The LAR subtype alone did not predict DFS; however, LAR tumors with apocrine differentiation had a better prognosis than did LAR tumors without apocrine differentiation. Using a combination of morphologic and genomic testing may be helpful in determining the prognosis of patients with apocrine-positive TNBC tumors who have residual disease after NST.

Citation Format: Masuda H, Miura S, Harano K, Wang Y, Hirota Y, Matsunaga Y, Lim B, Lucci A, Parinyanitikul N, Lee HJ, Gong G, Rao A, Seitz RS, Morris SW, Hout DR, Nakamura S, Tripathy D, Harada O, Krishnamurthy S, Ueno NT. Apocrine morphology and LAR molecular subtype predict prognosis of TNBC patients with residual disease after neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-02-05.

[A Case of Aplastic or Twig-like Middle Cerebral Artery with a Ruptured Aneurysm at an Anomalous Collateral Artery]

A 69-year-old man presented with sudden loss of consciousness and was admitted to our hospital. Computed tomography revealed diffuse subarachnoid hemorrhage. Digital subtraction angiography revealed occlusion of the left M1 segment, collateral arteries from the left A1 to the left M2 via twig-like networks, and a 6-mm aneurysm in the collateral arteries. Clipping surgery was performed on the 3rd hospital day. Vascular abnormalities of the middle cerebral artery with twig-like networks have been reported with an incidence of 0.11-0.17%. In addition, aneurysms are reported as complications in 40% of cases, suggesting hemodynamic stress and structural vulnerability. (Received January 16, 2018; Accepted June 21, 2018; Published September 1, 2018).

Development of a generalized hybrid Monte Carlo algorithm to generate the multicanonical ensemble with applications to molecular systems

In the present paper, a generalized hybrid Monte Carlo method to generate the multicanonical ensemble has been developed, which is a generalization of the multicanonical hybrid Monte Carlo (HMC) method by Hansmann and co-workers [Chem. Phys. Lett. 259, 321 (1996)]. The generalized hybrid Monte Carlo (GHMC) method is an equations-of-motion guided Monte Carlo combined with partial momentum refreshment. We successfully applied our multicanonical GHMC to dense Lennard-Jones fluids and a coarse grained protein model. It is found that good computational efficiency can be gained in the case of the acceptance ratio around 60% for the models examined. While a large number of molecular dynamics (MD) steps in a single GHMC cycle is needed to yield good computational efficiency at a large mixing ratio of momenta with thermal noise vectors, corresponding to the original multicanonical HMC method, a small number of MD steps are enough to achieve good efficiency at a small mixing ratio. This property is useful to develop a composite algorithm combining the present GHMC method with other Monte Carlo moves.

Isolation and Characterization of jararaca GPIb-BP, a Snake Venom Antagonist Specific to Platelet Glycoprotein lb

A platelet glycoprotein lb-binding protein (GPIb-BP) was isolated from the snake venom of Bothrops jararaca. Jararaca GPIb-BP showed a single band with Mr of 30,000, and two distinct bands with Mr. of 17,000/13,000 under non-reducing and reducing conditions, respectively, on SDS-polyacrylamide gel electrophoresis. Jararaca GPIb-BP itself induced neither platelet aggregation nor serotonin release from platelets, but specifically bound to GPIb (40,629 ± 2,521 molecules per normal platelet, with Kd 39.1 ± 2.4 nM at saturation). The purified venom protein completely inhibited ristocetin- or botrocetin-induccd von Willebrand factor (vWF) binding, and blocked the bovine vWF binding to GPIb, with IC50 values ranging from 28 to 42 nM, without affecting the platelet aggregation induced by ADP or α-thrombin. 1251-jararaca GPIb-BP binding to GPIb was not altered by the presence of human α-thrombin. Jararaca GPIb-BP at a final concentration of 104 nM totally abolished vWF-dependent shear- induced platelet aggregation (SIPA) at a high shear stress, but had no effect on SIPA at a low shear stress. Reduced and S-carboxyamidomethylated jararaca GPIb-BP lost its inhibitory activity on SIPA. The NH2-terminal amino acid sequences of the subunits revealed a high degree of homology with those of several Ca2+-dependent lectins, especially to those of two functionally opposite venom proteins, botrocetin (a vWF-modulator) and alboaggregin-B (a GPIb- modulator).

The Interaction of Botrocetin with Normal or Variant von Willebrand Factor (Types IIA and IIB) and Its Inhibition by Monoclonal Antibodies that Block Receptor Binding

We have recently shown the existence of two distinct forms of botrocetin (one-chain and two-chain), and demonstrated that the two-chain species is approximately 30 times more active than the one-chain in promoting von Willebrand factor (vWF) binding to platelet glycoprotein (GP) Ib. The N-terminal sequence of two-chain botrocetin is highly homologous to sea-urchin Echinoidin and other Ca2+-dependent lectins (Fujimura et al., Biochemistry 1991; 30: 1957–64).

Present data indicate that purified two-chain botrocetin binds to vWF from plasmas of patients with type IIA or IIB von Willebrand disease and its interaction is indistinguishable from that with vWF from normal individuals. However, an “activated complex” formed between botrocetin and IIB vWF expresses an enhanced biological activity for binding to GP Ib whereas the complex with IIA vWF has a decreased binding activity. Among several anti-vWF monoclonal antibodies (MoAbs) which inhibit ristocetin-induced platelet aggregation and/or vWF binding to GPIb, only two MoAbs (NMC-4 and RFF-VIII RAG:1) abolished direct binding between purified botrocetin and vWF. This suggests that they recognize an epitope(s) on the vWF molecule in close proximity to the botrocetin binding site.