Neuronavigation-Assisted Surgery for Distal Anterior Cerebral Artery Aneurysm

OBJECTIVE

We present our experience with the neuronavigation system as used for surgery of distal anterior cerebral artery (DACA) aneurysm.

METHODS

Between 2001 and 2004, 12 patients with a DACA aneurysm were consecutively treated with direct clipping assisted by the neuronavigation system. We used the BrainLAB Vector Vision neuronavigation system (BrainLAB, Heimstetten, Germany). Seven out of 12 patients presented with subarachnoid hemorrhage. Aneurysms were located at distal A2 in 10 patients and distal A3 in two patients. The size of the aneurysms ranged from 3-10 mm.

RESULTS

There were no procedure-related complications or technical problems during application of the neuronavigation system. The registration accuracy ranged from 0.5-1.5 mm (mean: 0.88 mm). The neuronavigation system provided real-time presentation of the DACA and the aneurysm, and allowed for identification of the DACA aneurysm in all patients. No surgical complications developed, and all 12 patients had a good recovery after direct clipping.

CONCLUSION

Although current neuronavigation systems are not available for all intracranial aneurysms, we believe that the DACA aneurysm is a good candidate for its use. The additional benefits of a small craniotomy and precise intraoperative orientation during surgery result in a minimally invasive aneurysm procedure.

Neuronavigation-Assisted Surgery for Distal Anterior Cerebral Artery Aneurysm

OBJECTIVE

We present our experience with the neuronavigation system used for surgery of distal anterior cerebral artery (DACA) aneurysms.

METHODS

Between 2001 and 2004, 12 patients with a DACA aneurysm were consecutively treated with direct clipping assisted by the neuronavigation system. We used the BrainLAB Vector Vision2 neuronavigation system (BrainLAB, Heimstetten, Germany). Seven out of 12 patients presented with subarachnoid hemorrhage. Aneurysms were located at distal A2 in 10 patients and distal A3 in two patients. The size of the aneurysms ranged from 3 to 10 mm.

RESULTS

There were no procedure-related complications or technical problems during application of the neuronavigation system. The registration accuracy ranged from 0.5 to 1.5 mm (mean: 0.88). The neuronavigation system provided real-time presentation of the DACA aneurysm, and allowed for identification of the DACA aneurysm in all patients. No surgical complications developed, and all 12 patients had a good recovery after direct clipping.

CONCLUSION

Although current neuronavigation systems are not available for all intracranial aneurysms, we believe that the DACA aneurysm is a good candidate for its use. The additional benefits of a small craniotomy and precise intraoperative orientation during surgery result in a minimally invasive aneurysm procedure.

Pulmonary cavitary mass containing a mural nodule: differential diagnosis between intracavitary aspergilloma and cavitating lung cancer on contrast-enhanced computed tomography

AIM

The objective of this study was to identify whether there were any significant differences in the computed tomography (CT) findings of an intracavitary aspergilloma and a cavitating lung cancer containing a mural nodule.

MATERIALS AND METHODS

The CT and histopathological findings of 12 patients (male:female ratio 3:9; aged 51-76 years) with cavitating lung cancer containing a mural nodule and 26 patients (male:female ratio 14:12; aged 29-72 years) with intracavitary aspergilloma were retrospectively reviewed.

RESULTS

The mural nodules within cavitating lung cancer were more enhanced (p<0.001) and showed a nondependent location more frequently (p=0.012) than those of intracavitary aspergillomas. The cavitary walls were thicker in cavitating lung cancer (mean 5.8mm thick) than those in intracavitary aspergillomas (mean 2.6mm thick; p=0.035). Adjacent bronchiectasis and volume decrease of the involved lobe were observed more frequently in intracavitary aspergillomas than in cavitating lung cancers (p<0.001 and p=0.008, respectively).

CONCLUSION

Whether a mural nodule within a cavitary lesion is contrast-enhanced or not is one of the most important features in making a differential diagnosis between an intracavitary aspergilloma and a cavitating lung cancer. Assessment of dependent location of a mural nodule within the cavity and wall thickness of the cavity itself can also be helpful for differentiation.

T-regulatory cells are relatively deficient in squamous carcinomas undergoing regression in mice immunized with a squamous carcinoma vaccine enriched for immunotherapeutic cells

In a prior report (Int J Cancer 2006; 119: 339-348), we described a new vaccination strategy for squamous cell carcinoma (SCC). The vaccine was prepared by transfer of unfractionated DNA-fragments (25 kb) from KLN205 cells, a squamous carcinoma cell line (DBA/2 origin; H-2(d)) into LM cells, a highly immunogenic mouse fibroblast cell line (C3H/He origin; (H-2(k))). As only a small proportion of the transfected cell population was expected to have incorporated DNA segments that included genes specifying antigens associated with the squamous carcinoma cells, we devised a novel strategy to enrich the vaccine for immunotherapeutic cells. Enhanced immunity to squamous carcinoma was induced in tumor-bearing mice treated solely by immunization with the enriched vaccine, which translated into prolonged survival without toxicity. Here, we describe the characteristics of the cell populations infiltrating established squamous carcinomas undergoing regression in mice immunized with vaccines enriched for immunotherapeutic cells. The results indicated that CD8+ T cells were predominant and that T-regulatory cells (FoxP3+, CD4/CD25+, CD4/CD62L(high), CD4/CTLA-4e) were relatively deficient in the regressing tumors. Inflammatory infiltrates were not detected in various organs and tissues of mice immunized with the DNA-based vaccine.

Kondo effect in magnetic tunnel junctions

Tunneling magnetoresistance was found to be suppressed with decreasing temperature for magnetic tunnel junctions (MTJs) oxidized under high plasma power. A strong temperature dependence of the junction resistance was observed, along with zero-bias anomalies of dynamic resistance at low temperatures. Resistance shows a logarithmic dependence on temperature, and resistance versus temperature exhibits a scaling behavior. Our experimental data can be explained in a consistent way by the Kondo effect in the MTJs with the Kondo temperature TK=20-30 K.

Diffusion PDE-based denoising technique for magnetic resonance electrical impedance tomography

Recent progress in magnetic resonance electrical impedance tomography (MREIT) research has shown that conductivity images with higher spatial resolution and accuracy are achievable. One of the most important remaining problems to be solved in MREIT before we can apply the technique to human subjects is how to reduce the amount of injection current. Since we use an MRI scanner to measure the induced magnetic flux density data subject to an injection current, the data is contaminated with random noise. In order to obtain enough signal-to-noise ratio (SNR), we need to inject a large amount of current into the subject. However, it is obvious that we must comply with the electrical safety regulations and this means that we should deal with noisy data having a low SNR due to the limited amount of injection current. Furthermore, in the developed reconstruction algorithms, the required numerical differentiations of the noisy data may result in deterioration of the reconstructed conductivity image leading to a loss of important information. We propose a PDE-based denoising technique that diminishes the degradation of reconstructed conductivity images due to the noise in measured data. The proposed PDE-based technique is advantageous in reducing the random noise while preserving useful features in MREIT.

DT-MRI regularization using 3D nonlinear gradient vector flow anisotropic diffusion

In DT-MRI, diffusion-weighted multislice echoplanar images (EPIs) are processed to represent water diffusion characteristics as a diffusion tensor, reflecting the amount of diffusion in 3D. However imaging quality is generally compromised by several factors including the number of imaging slices, averages, diffusion sensitization steps (b-values), voxel size, and gradient directions, resulting in suboptimal SNR. In this study, we focus on improving imaging quality and SNR by denoising and reducing systematic and random errors through nonlinear anisotropic regularization. The raw EPIs are directly regularized through a newly proposed nonlinear anisotropic diffusion regularization method in 3D utilizing the gradient vector flow fields and its performance is compared to conventional 2D and vector-valued 2D anisotropic regularization methods. The effects of these variants of anisotropic regularization are examined through the maps of color-coded fractional anisotropy and tracked neural fibers. The results show that DT-MRI regularization using the proposed 3D anisotropic diffusion significantly improves the quality of fiber tracking and diffusion indices such as fractional anisotropy.

New strategy for the identification of squamous carcinoma antigens that induce therapeutic immune responses in tumor-bearing mice

This study describes a new strategy for the identification of squamous carcinoma antigens tumor-associated antigens (TAA). The antigens were discovered by comparing microarrays of squamous carcinoma vaccines highly enriched for immunotherapeutic cells with non-enriched vaccines. The vaccines were prepared by transferring sheared genomic DNA fragments (25 kb) from KLN205 cells, a squamous carcinoma cell line (DBA/2 mouse origin (H-2(d)) into LM fibroblasts (C3H/He origin, H-2(k)). The transferred tumor DNA segments integrate spontaneously into the genome of the recipient cells, replicate as the cells divide and are expressed. As only a small proportion of the transfected cell population was expected to have incorporated DNA segments that included genes specifying TAA (the vast majority specify normal cellular constituents), a novel strategy was employed to enrich the vaccine for TAA-positive cells. Microarrays were used to compare genes expressed by enriched and non-enriched vaccines. Seventy-five genes were overexpressed in cells from the enriched vaccine. One, the gene for Cytochrome P450 (family 2, subfamily e, polypeptide 1) (Cyp2e1), was overexpressed in the enriched but not the non-enriched vaccine. A vaccine for squamous carcinoma was prepared by transfer of a 357 bp fragment of the gene for Cyp2e1 into the fibroblast cell line. Robust immunity, sufficient to result in indefinite survival, was induced in tumor-bearing mice immunized with cells transfected with this gene fragment.

Relationship between personality disorder symptoms and temperament in the young male general population of South Korea

The aim of the present study was to identify the characteristics of temperament and character in personality disorder symptoms in the young male general population. A total of 585 male subjects from the same community were included in the study (mean age, 19.06 +/- 0.26 years). There was no difference in socioeconomic and educational background. Subjects completed the Personality Disorder Questionnaire-IV+ (PDQ-IV+) and Temperament and Character Inventory (TCI). There were unique correlations between each personality disorder symptom and four temperament profiles. When classification was done through three cluster symptoms by DSM-IV, cluster A symptoms were most strongly associated with low reward dependence (r = -0.46), cluster B with high novelty seeking (r = 0.33), and cluster C with high harm avoidance (r = 0.47). The character dimension, self-directedness was the most powerful predictor of the presence of any personality disorders. In homogenous male general population, unique combinations were found between temperament and each personality disorders. Although the subjects were relatively young and therefore their characters had not yet fully matured, character played an important role in the presence of personality disorder. Temperament can be used to differentiate the personality symptoms and characters used to predict the presence of personality disorder.

Extraction and localization of alpha activity of the brain in EEG and fMRI using constrained ICA

In order to extract only the alpha activity related EEG signals of the brain, we have applied constrained Independent Component Analysis (cICA), a new extension of ICA in which some a priori knowledge of alpha activity is utilized to extract desired components. Its performance has been compared to that of conventional band-pass filtering via the scalp power maps of alpha activity. The preliminary results show that cICA-extracted alpha signals produce the alpha power maps which spatially match the activated regions of the brain mapped using fMRI more closely than those from the band-pass filtered alpha EEG signals. The use of cICA might provide a more effective means of extracting EEG alpha activity of the brain.

Early cysteine protease activity in excretory bladder triggers metacercaria excystment of Paragonimus westermani

The cysteine proteases of Paragonimus westermani metacercaria are known to initiate metacercaria excystment. However, their secretory sites, such as the intestine, tegument, and excretory bladder are not well defined. In this study, the metacercariae were labeled with bromodeoxyuridine (BrdU) to distinguish the initial activation sites. BrdU was labeled mainly at the excretory bladder and the excretory granules of the metacercariae and the newly excysted juvenile worms. This result shows that early 'defecation' of the proteases from the excretory bladder may accelerate the excystment of P. westermani metacercariae.

Interrelationships among Pain, Disability, and Psychological Factors in Young Korean Conscripts with Lumbar Disc Herniation

The aim of this study was to compare the psychological factors between young Korean conscripts with lumbar disc herniation (LDH) and healthy controls and to evaluate the interrelationships among pain, disability, and psychological factors in LDH conscripts. The subjects consisted of 56 young conscripts with LDH and 76 controls. All subjects completed Beck's Depression Inventory and Spielberger's State-Trait Anxiety Inventory. To evaluate pain intensity and functional disability, the Visual Analogue Scale and the Modified Oswestry Low Back Pain Disability Questionnaire were used. LDH conscripts had more depression and anxiety than the controls. The functional disability of the LDH conscripts was significantly related to the four variables: pain intensity, depression, state anxiety, and trait anxiety. Pain intensity and state anxiety significantly contributed to the functional disability in the LDH conscripts. This study suggests that LDH conscripts have some psychological problems, such as depression and anxiety, in comparison to healthy controls. Furthermore, the pain intensity and state anxiety predict the functional disability in LDH conscripts.

Clinical Utility of Multislice Computed Tomographic Angiography for Detection of Cerebral Vasospasm in Acute Subarachnoid Hemorrhage

Digital subtraction angiography (DSA) has been used as the standard method for detecting cerebral vasospasm after subarachnoid hemorrhage (SAH). Multislice computed tomographic angiography (CTA) is a relatively recent method used for evaluating the vasculature of the intracranial arteries. The purpose of this study was to compare multislice CTA and DSA for the detection and quantification of cerebral vasospasm after SAH, and to analyze the usefulness of multislice CTA. Eight patients with SAH underwent initial CTA with DSA within 72 hours after the onset of symptoms and follow-up multislice CTA and DSA 8 to 48 days after SAH. Five arterial locations were established in the A1 and A2 segments of the anterior cerebral artery, the M1 and M2 segments of the middle cerebral artery and the posterior cerebral artery (PCA) on both multislice CTA and DSA images. Vasospasm was classified as none, mild (up to 30% reduction in luminal diameter), moderate (31-60% reduction), and marked (at least 60% reduction) using the scale of Schneck and Kricheff. The multislice CT system used the following parameters: 1.25 mm collimation and 3.75 pitch with a 4-channel system. The degree of vasospasm revealed by the multislice CTA was significantly correlated with the degree of vasospasm revealed by DSA. In general, most discrepancies between CTA and DSA were in the detection of mild and moderate vasospasm. We found that the consistency between multislice CTA and DSA was greater for mild (100%, n=3) or moderate (100%, n=3) vasospasm than none (n=1) or marked vasospasm (n=1). However, it was unclear whether multislice CTA was more specific for a proximal location (A1, M1, PCA) or distal location (A2, M2) for evaluation of cerebral arteries. Multislice CTA can detect angiographic vasospasm after SAH with an accuracy similar to that of DSA. Multislice CTA is highly sensitive, specific and accurate in detecting mild and moderate cerebral vasospasm. It is less accurate for detecting no vasospasm and marked vasospasm. Therefore, the authors propose that multislice CTA be considered as a useful tool for the detection and management of intracranial vasospasm after SAH.

Benign localized fibrous tumour of the pleura: CT features with histopathological correlations

AIM

To assess the CT features of benign localized fibrous tumour of the pleura, with histopathological correlations.

MATERIALS AND METHODS

CT and histopathological findings of 18 patients with surgically resected benign localized fibrous tumour of the pleura were retrospectively assessed.

RESULTS

Tumours were pleura or fissure based, semilunar, lentiform or oval in shape, classified according to their homogeneous, slightly heterogeneous or heterogeneous enhancement pattern. Of the 18 tumours, 5 (28%) demonstrated > or = 55 HU increment or higher attenuation than muscles on contrast-enhanced CT, and histopathologically showed a haemangiopericytoma-like pattern with rich vascularity.

CONCLUSION

CT analysis of the shape of a mass and the enhancement pattern can be helpful in the diagnosis of benign localized fibrous tumour of the pleura.

Interleukin-18 is a critical factor for vascular endothelial growth factor-enhanced migration in human gastric cancer cell lines

Cell migration and angiogenesis are key steps in tumor metastasis. However, the mechanism of migration regulated by vascular endothelial growth factor (VEGF), a potent regulator of angiogenesis, is not completely understood. This study examined the relationship between VEGF and migration, along with the mechanism involved in the VEGF-regulated migration of human gastric cancer cells. The level of cell migration was increased by recombinant human (rh)VEGF-165 in the VEGF receptor-2-expressing SNU-601 cells. Interleukin (IL)-18 is associated with the malignant progression of tumors. Accordingly, this study examined the effect of IL-18 on the migration of cancer cells in order to identify the factors involved in VEGF-enhanced migration. Inhibiting IL-18 markedly reduced the level of VEGF-enhanced migration, and IL-18 increased cell migration directly through filamentous-actin polymerization and tensin downregulation. It was confirmed that rhVEGF-165 increased IL-18 production significantly. An antioxidant and an extracellular signal-regulated kinase (ERK)1/2-specific inhibitor blocked rhVEGF-165-enhanced IL-18 production. Accordingly, rhVEGF-165 increased the generation of region of interest (ROI) and activated the ERK1/2 pathway. These results suggest that rhVEGF-165 enhances IL-18 production via the generation of ROI and ERK1/2 phosphorylation, which results in the increased migration of gastric cancer cells.

Psychological burdens are associated with young male transsexuals in Korea

The purpose of this study was to compare differences of the psychological burdens between young male transsexuals and age-gender matched non-transsexuals with standardized psychiatric rating scales in Korea. A total of 43 biologically unrelated young male transsexuals and 49 age-gender matched non-transsexuals participated in the study. All subjects completed Beck's Depression Inventory (BDI), Social Avoidance and Distress Scale (SADS), Self-Esteem Scale (SES) and Family Adaptability and Cohesion Evaluation Scale (FACES-III). The transsexuals showed significantly higher scores on the BDI (P < 0.0001) and SADS (P = 0.002) and lower scores on the SES (P < 0.0001) and Adaptability and Cohesion subscales (P = 0.016 and P < 0.0001, respectively) of the FACES-III than those of the non-transsexuals. The present study found young male transsexuals may be potentially vulnerable to develop psychiatric and familial problems in comparison with non-transsexuals, at least in Korea, although methodological limitations exist. Further well-designed researches should be launched to confirm this preliminary study.

COMPARISON OF GENE REPRESENTATION BETWEEN DIPLOID AND TRIPLOID PARAGONIMUS WESTERMANI BY EXPRESSED SEQUENCE TAG ANALYSES

Expressed sequence tag (EST) analysis of the diploid and triploid Paragonimus westermani genes was done to have a rapid and informative outlook of the gene-expression profiles of the parasites. Totals of 506 and 505 ESTs were generated from the diploid and triploid P. westermani cDNA libraries. Based on the BLASTx search results of the diploid P. westermani ESTs, 308 (60.9%) matched significantly with formerly identified genes and 198 (39.1%) showed no significant homology in the GenBank database. A similar homology pattern was shown from the triploid EST BLASTx search results with 346 (68.5%) sharing homology with previously identified genes and 159 (31.5%) showing no significant homology. The EST data from both libraries were analyzed and grouped into 9 categories. Comparison of the 2 EST pools revealed high similarities among the categories of the significantly matched genes. Single genes matched repeatedly were also observed in the 2 EST data. Some genes were found that are not yet characterized in P. westermani; these genes were matched by both the diploid and triploid ESTs. Further study of these genes may provide us with more understanding on the parasite's biology and their specific functions in the 2 strains.

Changes of serum cytokine profiles in Korean vivax malarial patients after chemotherapy

Changes of serum cytokines including interferon gamma inducible protein-10 (IP-10) chemokine were analyzed in a total of eight vivax malarial patients before and after chemotherapy by immunostaining for human cytokine antibodies attached to membranes. IP-10 was strongly reactive in the period before chloroquine/primaquine combined chemotherapy and disappeared after chemotherapy in all patients. Therefore, IP-10 chemokine may be of importance in the pathogenesis of vivax malaria and a good marker of a complete cure.

Role of molecular orbitals of the benzene in electronic nanodevices

In an effort to examine the intricacies of electronic nanodevices, we present an atomistic description of the electronic transport properties of an isolated benzene molecule. We have carried out ab initio calculations to understand the modulation of the molecular orbitals (MOs) and their energy spectra under the external electric field, and conducting behavior of the benzene molecule. Our study shows that with an increase in the applied electric field, the energy of the third lowest unoccupied molecular orbital (LUMO) of benzene decreases, while the first and second LUMO energies are not affected. Above a certain threshold of the external electric field, the third LUMO is lowered below the original LUMO and becomes the real LUMO. Since the transport through a molecule is to a large extent mediated by the molecular orbitals, the change in MOs can lead to a dramatic increase in the current passing through the benzene molecule. Thus, in the course of this study, we show that the modulation of the molecular orbitals in the presence of a tuning parameter(s) such as the external electric field can play important roles in the operation of molecular devices. We believe that this understanding would be helpful in the design of electronic nanodevices.

Spinal metastasis from cranial meningeal hemangiopericytomas

Spine metastasis from cranial meningeal hemangiopericytomas are extremely rare, with five surgically verified cases. We describe a case of a 55-year-old female diagnosed with metastatic hemangiopericytoma to the cervical spine 78 months after the first operation. Because of the long latency period, aggressive spinal surveillance should be advocated along with repeated bone scintigraphy and MRI.

Comparison of venlafaxine extended release versus paroxetine for treatment of patients with generalized anxiety disorder

This trial was to evaluate the efficacy and tolerability of venlafaxine extended release (XR) and paroxetine for treatment of patients with generalized anxiety disorder (GAD). Sixty patients who met DSM-IV criteria for GAD were randomly assigned to either venlafaxine XR or paroxetine for 8 weeks. Efficacy was assessed with the Hamilton Rating Scale for Anxiety (HAM-A) and Clinical Global Impression-Severity of Illness (CGI-S) scale at the baseline, week 1, week 4, and week 8. The side-effects were collected with reported adverse events and laboratory tests throughout the study period. Repeated measures analysis of variance (ANOVA) on the HAM-A and CGI-S scores showed a significant decrease over time in both treatment groups without significant group difference or time x group interaction effect. There were no serious adverse events in both groups. This open trial demonstrated that either venlafaxine XR or paroxetine would be effective and tolerable for the treatment of patients with GAD. Double blind, placebo-controlled head-to-head comparison studies are needed to draw a definite conclusion.

Temperament and character dimensions in patients with atopic dermatitis

The aim of this study was to assess the personality traits of young male patients with atopic dermatitis (AD), and to examine the correlations between temperament and character dimensions with clinical and other psychological factors. Fifty young adult male AD patients and 83 healthy controls were examined using the temperament and character inventory, the Beck depression inventory and the state-trait anxiety inventory. The AD patients scored higher on harm avoidance and lower on reward dependence, self-directedness and cooperativeness than the healthy controls. The illness duration and anxiety correlated negatively with the self-directedness score, and depression correlated negatively with reward dependence and the persistence scores in AD patients. These results suggest that AD patients have distinctive temperament and character dimensions compared to healthy controls. Moreover, illness duration and anxiety might be associated with some personality problems, and some temperament dimensions (e.g. reward dependence, persistence) may be linked to depressive symptoms in AD patients.

Antipsychotic treatment may alter T-helper (TH) 2 arm cytokines

The alteration of T helper 1 (TH1) and TH2 responses and related cell-mediated immunity has been supposed to be associated with the immunological pathogenesis in the development of schizophrenia. Increasing evidence suggested the alteration of cytokines in accordance with the antipsychotic treatment as well, so that this study aimed at investigating the aberration of TH1 and -2 cytokines before and after antipsychotic treatment in patients with schizophrenia. Thirty-five schizophrenic patients with antipsychotic naïve or free more than 2 months participated in the study. We measured the plasma levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-2 (TH1), and IL-6, IL-10 and IL-13 (TH2) at the time of admission and after an 8-week antipsychotic treatment. The IL-6 (p = 0.001) and -13 (p = 0.004) levels were significantly decreased after antipsychotic treatment than those of before antipsychotic treatment. The total and general PANSS score changes were correlated with the change of IL-6 (r = 0.598, corrected p < 0.05; r = 0.550, corrected p = 0.005, respectively). The baseline IL-6 level was correlated with change of general PANSS score (r = 0.449, corrected p = 0.044), whereas changes of other PANSS scores were not correlated with any other baseline cytokine levels. The baseline total PANSS score was correlated with the baseline levels of IL-13 (r = 0.776, corrected p < 0.005). The baseline total and general PANSS scores were correlated with the baseline levels of IL-6 (r = 0.689, corrected p < 0.005; r = 0.653, corrected p < 0.005). The correlations between the baseline levels of cytokines and the duration of illness and the age at onset were not found. Our study supports that TH-2 arm cytokines may be involved in the improvement of psychopathology and symptomatologies of schizophrenia and that antipsychotic drugs may suppress some TH-2 cytokines in patients with schizophrenia.