Ursolic acid inhibits the synaptic release of glutamate and prevents glutamate excitotoxicity in rats

The present study evaluated the effect of ursolic acid, a natural pentacyclic triterpenoid, on glutamate release in rat cortical nerve terminals (synaptosomes) and its neuroprotection in a kainic acid-induced excitotoxicity rat model. In cortical synaptosomes, ursolic acid produced a concentration-dependent inhibition of evoked glutamate release with a half-maximum inhibition of release value of 9.5 μM, and calcium-free medium and the P/Q -type Ca2+ channel blocker, ω-agatoxin IVA, but not ω-conotoxin GVIA, an N-type Ca2+ channel blocker, prevented the ursoloic acid effect. The molecular docking study indicated that ursolic acid interacted with P/Q-type Ca2+ channels. Ursolic acid also significantly decreased the depolarization-induced activation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) and the subsequent phosphorylation of synapsin I, and the ursolic acid effect on evoked glutamate release was inhibited by the CaMKII inhibitor KN 62 in synaptosomes. In addition, in rats that were intraperitoneally injected with ursolic acid 30 min before kainic acid intraperitoneal injection, cortical neuronal degeneration was attenuated. This effect of ursolic acid in the improvement of kainic acid-induced neuronal damage was associated with the reduction of kainic acid-induced glutamate increase in the cortex of rats; this was characterized by the reduction of glutamate and glutaminase levels and elevation of glutamate dehydrogenase, glutamate transporter 1, glutamate-aspartate transporter, and glutamine synthetase protein levels. These results suggest that ursolic acid inhibits glutamate release from cortical synaptosomes by decreasing P/Q-type Ca2+ channel activity and subsequently suppressing CaMKII and exerts a preventive effect against glutamate neurotoxicity by controlling glutamate levels.

Metamaterials of Auxetic Geometry for Seismic Energy Absorption

The propagation of earthquake energy occurs primarily through elastic waves. If the seismic force input to a structure can be directly reduced from the source, then the structure can be protected from seismic wave energy. Seismic metamaterials, regarded as periodic structures with properties different from conventional materials, use wave propagation characteristics and bandgaps to dissipate seismic wave energy. When the seismic wave is located in the bandgap, the transmission of seismic wave energy is effectively reduced, which protects the structure from the damage caused by seismic disturbance. In practical application, locating seismic frequencies below ten Hz is a challenge for seismic metamaterials. In the commonly used method, high-mass materials are employed to induce the effect of local resonance, which is not economically feasible. In this study, a lightweight design using auxetic geometry is proposed to facilitate the practical feasibility of seismic metamaterials. The benefits of this design are proven by comparing conventional seismic metamaterials with metamaterials of auxetic geometry. Different geometric parameters are defined using auxetic geometry to determine the structure with the best bandgap performance. Finite element simulations are conducted to evaluate the vibration reduction benefits of auxetic seismic metamaterials in time and frequency domains. Additionally, the relationship between the mass and stiffness of the unit structure is derived from the analytical solution of one-dimensional periodic structures, and modal analysis results of auxetic metamaterials are verified. This study provides seismic metamaterials that are lightweight, small in volume, and possess low-frequency bandgaps for practical applications.

Evaluation and Application of Drug Resistance by Biomarkers in the Clinical Treatment of Liver Cancer

Liver cancer is one of the most lethal cancers in the world, mainly owing to the lack of effective means for early monitoring and treatment. Accordingly, there is considerable research interest in various clinically applicable methods for addressing these unmet needs. At present, the most commonly used biomarker for the early diagnosis of liver cancer is alpha-fetoprotein (AFP), but AFP is sensitive to interference from other factors and cannot really be used as the basis for determining liver cancer. Treatment options in addition to liver surgery (resection, transplantation) include radiation therapy, chemotherapy, and targeted therapy. However, even more expensive targeted drug therapies have a limited impact on the clinical outcome of liver cancer. One of the big reasons is the rapid emergence of drug resistance. Therefore, in addition to finding effective biomarkers for early diagnosis, an important focus of current discussions is on how to effectively adjust and select drug strategies and guidelines for the treatment of liver cancer patients. In this review, we bring this thought process to the drug resistance problem faced by different treatment strategies, approaching it from the perspective of gene expression and molecular biology and the possibility of finding effective solutions.

LPAL2 Suppresses Tumor Growth and Metastasis of Hepatocellular Carcinoma by Modulating MMP9 Expression

Tumor metastasis is a complex process modulated by both intrinsic and extrinsic factors that ultimately result in poorer patient outcomes, including diminished survival. Pseudogene-derived long non-coding RNAs (lncRNA) play important roles in cancer progression. In the current study, we found that the pseudogene-derived lncRNA LPAL2 is downregulated in hepatocellular carcinoma (HCC) tissues, and further showed that elevated LPAL2 expression is positively correlated with survival outcome. The knockdown of LPAL2 in hepatoma cells induced tumor formation, migration, invasion, sphere formation, and drug resistance. Metalloproteinase 9 (MMP9) was identified as an LPAL2-regulated target gene, consistent with clinical findings that LPAL2 expression is significantly associated with MMP9 expression. Furthermore, patients with a higher expression of LPAL2 and lower expression of MMP9 (LPAL2-high/MMP9-low) had a higher survival rate than those with other combinations. Collectively, our findings establish LPAL2 as a novel tumor suppressor in HCC, and suggest targeting LPAL2 and MMP9 as a therapeutic approach for the treatment of HCC.

Damage Detection of Regular Civil Buildings Using Modified Multi-Scale Symbolic Dynamic Entropy

Based on the examination of the fundamental characteristics of structures, structural health monitoring (SHM) has received increased attention in recent years. Studies have shown that the SHM method using entropy analysis can precisely identify the damaged location of the structure, which is very helpful for the daily inspection or maintenance of civil structures. Although entropy analysis has shown excellent accuracy, it still consumes too much time and too many resources in terms of data processing. To improve the dilemma, in this study, modified multi-scale symbolic dynamic entropy (MMSDE) is adopted to identify the damaged location of the civil structure. A damage index (DI) based on the entropy diagram is also proposed to clearly indicate the damage location. A seven-story numerical model was created to verify the efficiency of the proposed SHM system. The results of the analysis of each case of damage show that the MMSDE curve for the damaged floor is lower than that for the healthy floor, and the structural damage can be correctly diagnosed by the damage index. Subsequently, a scaled-down steel benchmark experiment, including 15 damage cases, was conducted to verify the practical performance of the SHM system. The confusion matrix was used to further evaluate the SHM system. The results demonstrated that the MMSD-based system can quickly diagnose structural safety with reliability and accuracy. It can be used in the field of long-term structural health monitoring in the near future.

Effects of Thyroid Hormones on Lipid Metabolism Pathologies in Non-Alcoholic Fatty Liver Disease

The typical modern lifestyle contributes to the development of many metabolic-related disorders, as exemplified by metabolic syndrome. How to prevent, resolve, or avoid subsequent deterioration of metabolic disturbances and the development of more serious diseases has become an important and much-discussed health issue. Thus, the question of the physiological and pathological roles of thyroid hormones (THs) in metabolism has never gone out of fashion. Although THs influence almost all organs, the liver is one of the most important targets as well as the hub of metabolic homeostasis. When this homeostasis is out of balance, diseases may result. In the current review, we summarize the common features and actions of THs, first focusing on their effects on lipid metabolism in the liver. In the second half of the review, we turn to a consideration of non-alcoholic fatty liver disease (NAFLD), a disease characterized by excessive accumulation of fat in the liver that is independent of heavy alcohol consumption. NAFLD is a growing health problem that currently affects ~25% of the world’s population. Unfortunately, there are currently no approved therapies specific for NAFLD, which, if left uncontrolled, may progress to more serious diseases, such as cirrhosis or liver cancer. This absence of effective treatment can also result in the development of non-alcoholic steatohepatitis (NASH), an aggressive form of NAFLD that is the leading cause of liver transplantation in the United States. Because THs play a clear role in hepatic fat metabolism, their potential application in the prevention and treatment of NAFLD has attracted considerable research attention. Studies that have investigated the use of TH-related compounds in the management of NAFLD are also summarized in the latter part of this review. An important take-home point of this review is that a comprehensive understanding of the physiological and pathological roles of THs in liver fat metabolism is possible, despite the complexities of this regulatory axis—an understanding that has clinical value for the specific management of NAFLD.

Kaempferol 3-Rhamnoside on Glutamate Release from Rat Cerebrocortical Nerve Terminals Involves P/Q-Type Ca2+ Channel and Ca2+/Calmodulin-Dependent Protein Kinase II-Dependent Pathway Suppression

Excess synaptic glutamate release has pathological consequences, and the inhibition of glutamate release is crucial for neuroprotection. Kaempferol 3-rhamnoside (KR) is a flavonoid isolated from Schima superba with neuroprotective properties, and its effecton the release of glutamate from rat cerebrocortical nerve terminals was investigated. KR produced a concentration-dependent inhibition of 4-aminopyridine (4-AP)-evoked glutamate release with half-maximal inhibitory concentration value of 17 µM. The inhibition of glutamate release by KR was completely abolished by the omission of external Ca²⁺ or the depletion of glutamate in synaptic vesicles, and it was unaffected by blocking carrier-mediated release. In addition, KR reduced the 4-AP-evoked increase in Ca²⁺ concentration, while it did not affect 4-AP-evoked membrane potential depolarization. The application of selective antagonists of voltage-dependent Ca²⁺ channels revealed that the KR-mediated inhibition of glutamate release involved the suppression of P/Q-type Ca²⁺ channel activity. Furthermore, the inhibition of release was abolished by the calmodulin antagonist, W7, and Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) inhibitor, KN62, but not by the protein kinase A (PKA) inhibitor, H89, or the protein kinase C (PKC) inhibitor, GF109203X. We also found that KR reduced the 4-AP-induced increase in phosphorylation of CaMKII and its substrate synapsin I. Thus, the effect of KR on evoked glutamate release is likely linked to a decrease in P/Q-type Ca²⁺ channel activity, as well as to the consequent reduction in the CaMKII/synapsin I pathway.

The Artificial Intelligence of Things Sensing System of Real-Time Bridge Scour Monitoring for Early Warning during Floods

Scour around bridge piers remains the leading cause of bridge failure induced in flood. Floods and torrential rains erode riverbeds and damage cross-river structures, causing bridge collapse and a severe threat to property and life. Reductions in bridge-safety capacity need to be monitored during flood periods to protect the traveling public. In the present study, a scour monitoring system designed with vibration-based arrayed sensors consisting of a combination of Internet of Things (IoT) and artificial intelligence (AI) is developed and implemented to obtain real-time scour depth measurements. These vibration-based micro-electro-mechanical systems (MEMS) sensors are packaged in a waterproof stainless steel ball within a rebar cage to resist a harsh environment in floods. The floodwater-level changes around the bridge pier are performed using real-time CCTV images by the Mask R-CNN deep learning model. The scour-depth evolution is simulated using the hydrodynamic model with the selected local scour formulas and the sediment transport equation. The laboratory and field measurement results demonstrated the success of the early warning system for monitoring the real-time bridge scour-depth evolution.

Dysregulated FAM215A Stimulates LAMP2 Expression to Confer Drug-Resistant and Malignant in Human Liver Cancer

Hepatocellular carcinoma (HCC) is one of the most common and aggressive human malignancies worldwide. Long non-coding (lnc) RNAs regulate complex cellular functions, such as cell growth, differentiation, metabolism, and metastasis. Although deregulation of lncRNA expression has been detected in HCC, many of the hepato-carcinogenesis-associated lncRNAs remain yet unidentified. Here, we aimed to investigate the involvement of a specific HCC-dysregulated lncRNA, FAM215A, and characterize its molecular regulation mechanism. We show for the first time that FAM215A is overexpressed in HCC, and its expression level correlates with tumor size, vascular invasion, and pathology stage. Overexpression of FAM215A accelerates cell proliferation and metastasis in HCC cells. According to Gene Expression Omnibus Dataset analysis, FAM215A is induced in doxorubicin (DOX)-resistant HCC cells. Overexpression of FAM215A increases DOX resistance in two HCC cell lines, and this is associated with enhanced expression of lysosome-associated membrane protein 2 (LAMP2). FAM215A interacts with LAMP2 to protect it from ubiquitination. Together, our results show that the lncRNA, FAM215A, is highly expressed in HCC, where it interacts with and stabilizes LAMP2 to increase tumor progression while decreasing doxorubicin sensitivity.

Performance Evaluation of an Entropy-Based Structural Health Monitoring System Utilizing Composite Multiscale Cross-Sample Entropy

The aim of this study was to develop an entropy-based structural health monitoring system for solving the problem of unstable entropy values observed when multiscale cross-sample entropy (MSCE) is employed to assess damage in real structures. Composite MSCE was utilized to enhance the reliability of entropy values on every scale. Additionally, the first mode of a structure was extracted using ensemble empirical mode decomposition to conduct entropy analysis and evaluate the accuracy of damage assessment. A seven-story model was created to validate the efficiency of the proposed method and the damage index. Subsequently, an experiment was conducted on a seven-story steel benchmark structure including 15 damaged cases to compare the numerical and experimental models. A confusion matrix was applied to classify the results and evaluate the performance over three indices: accuracy, precision, and recall. The results revealed the feasibility of the modified structural health monitoring system and demonstrated its potential in the field of long-term monitoring.

Targeting inhibitors of apoptosis proteins suppresses medulloblastoma cell proliferation via G2/M phase arrest and attenuated neddylation of p21

Medulloblastoma (MB) is the most common type of malignant childhood brain tumor. We previously showed that inhibitors of apoptosis proteins (IAP) small‐molecule inhibitors (LCL161 or LBW242) combined with chemotherapy have synergistic antiproliferative effects on MB cells. The synergistic antitumor effects of combination treatments happen through induction of autophagy and caspase‐3/7‐activated apoptosis. Here, we investigated the effects of IAP inhibitors or silencing IAP on cell cycle regulation. We discovered that treatment with IAP inhibitors or their combination with conventional chemotherapy (vincristine or cisplatin), as well as RNAi knockdown of cIAP1/2 or XIAP arrested MB cells in the G2/M phase through downregulation of cyclin B1‐CDK1 and cyclin A‐CDK1/2. Among these three IAPs, only silencing cIAP1 expression enhanced p21 dependent‐G2/M phase accumulation. IAP inhibitors reduced cIAP1 expression and increased p21 expression in time course experiments. Furthermore, cIAP1 can govern p21 proteasomal degradation via neddylation in lieu of ubiquitination. Inhibition of IAPs significantly abrogated cIAP1‐mediated p21 degradation. We also observed an inverse correlation between nuclear cIAP1 and nuclear p21 expressions in MB tumor tissues. These findings provide new mechanistic evidence of the influence of IAP inhibitors on MB cell proliferation through disruption of the cell cycle.

The Long Non-Coding RNA MIR503HG Enhances Proliferation of Human ALK-Negative Anaplastic Large-Cell Lymphoma

Anaplastic lymphoma kinase (ALK)-negative anaplastic large-cell lymphoma (ALCL) is a rare type of highly malignant, non-Hodgkin lymphoma. Currently, only a few gene rearrangements have been linked to ALK-negative ALCL progression. However, the specific molecular mechanisms underlying the growth of ALK-negative ALCL tumors remain unclear. Here, we investigated aberrantly expressed, long non-coding RNAs (lncRNAs) in ALK-negative ALCL and assessed their potential biological function. MIR503HG (miR-503 host gene) was highly expressed in ALK-negative cell lines and was significantly upregulated in tumors in mice formed from ALK-negative ALCL cell lines. Depletion of MIR503HG suppressed tumor cell proliferation in vivo and in vitro; conversely, its overexpression enhanced tumor cell growth. MIR503HG-induced proliferation was mediated by the induction of microRNA-503 (miR-503) and suppression of Smurf2, resulting in stabilization of the tumor growth factor-β receptor (TGFBR) and enhanced tumor cell growth. Collectively, these findings support a potential role for MIR503HG in cancer cell proliferation through the miR-503/Smurf2/TGFBR axis and indicate that MIR503HG is a potential marker in ALK-negative ALCL.

Stimulation of Interferon-Stimulated Gene 20 by Thyroid Hormone Enhances Angiogenesis in Liver Cancer

Thyroid hormone, 3,3′,5-triiodo-l-thyronine (T₃), mediates several physiological processes, including embryonic development, cellular differentiation and cell proliferation, via binding to its nuclear thyroid receptors (TR). Previous microarray and Chromatin immunoprecipitation (ChIP)-on-ChIP analyses have revealed that interferon-stimulated gene 20 kDa (ISG20), an exoribonuclease involved in the antiviral function of interferon, is up-regulated by T₃ in HepG2-TR cells. However, the underlying mechanisms of ISG20 action in tumor progression remain unknown to date. Here, we verified induction of ISG20 mRNA and protein expression by T₃ in HepG2-TR cells. Based on the ChIP-on-ChIP database, potential thyroid hormone responsive element of the ISG20 promoter region was predicted, and the result confirmed with the ChIP assay. Functional assays showed that forced expression of ISG20 leads to significant promotion of metastasis and angiogenesis, both in vitro and in vivo. Furthermore, the angiogenic-related protein, interleukin-8 (IL-8), was up-regulated through a T₃-mediated increase in ISG20, as determined using a human angiogenesis array kit. Induction of IL-8 signaling activated the p-JAK2/p-STAT3 pathway, in turn, leading to promotion of tumor metastasis and angiogenesis. Furthermore, ISG20 overexpression in hepatocellular carcinoma (HCC) specimens was positively correlated with clinical parameters, including vascular invasion, α-fetoprotein and tumor size. Higher ISG20 expression was significantly correlated with poorer recurrence-free survival in HCC patients. Our results collectively indicate higher TR-dependent expression of ISG20 in a subset of HCC, supporting an oncogenic role in HCC progression.

Cross-Talk Immunity of PEDOT:PSS Pressure Sensing Arrays with Gold Nanoparticle Incorporation

In this study, the cross-talk effects and the basic piezoresistive characteristics of gold nanoparticle (Au-NP) incorporated poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) pressure sensing 2 × 2 arrays are investigated using a cross-point electrode (CPE) structure. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) mappings were carried out to confirm the incorporation of Au-NPs in the PEDOT:PSS films. A solution mixing process was employed to incorporate the nanoparticles. When the diameter of the Au-NPs incorporated in the PEDOT:PSS films (Au-NPs/PEDOT:PSS) was 20 nm, the piezoresistive pressure sensing 2 × 2 arrays were almost immune to cross-talk effects, which enhances the pressure sensing accuracy of the array. The Au-NPs render the PEDOT:PSS films more resilient. This is confirmed by the high plastic resistance values using a nanoindenter, which reduce the interference between the active and passive cells. When the size of the Au-NPs is more than 20 nm, a significant cross-talk effect is observed in the pressure sensing arrays as a result of the high conductivity of the Au-NPs/PEDOT:PSS films with large Au-NPs. With the incorporation of optimally sized Au-NPs, the PEDOT:PSS piezoresistive pressure sensing arrays can be promising candidates for future high-resolution fingerprint identification system with multiple-electrode array structures.

The long non-coding RNA LOC441204 enhances cell growth in human glioma

Glioma is the most common and aggressive type of brain tumor. While long non-coding RNAs (lncRNAs) are clearly more abundant in human brain than protein-coding genes, the specific roles of lncRNAs and mechanisms underlying their dysregulation in glioma remain unclear. Here, we focused on lncRNAs that are differentially expressed in brain tumor and their potential biological functions. LOC441204, a novel non-coding RNA gene displaying high expression in clinical specimens of brain tumor and significant upregulation in glioma cell lines in microarray analyses, was selected for further study. Notably, knockdown of LOC441204 suppressed tumor cell proliferation in two glioma cell lines. Moreover, LOC441204-induced tumor cell growth was mediated the stabilization of β-catenin pathway. Briefly, LOC441204 bound to β-catenin preventing its degradation, resulting in downstream p21 repression and cdk4 activation to enhance glioma cell proliferation. Collectively, our findings indicate a pro-oncogenic role of LOC441204 in tumor cell growth through activation of the β-catenin/p21/cdk4 cascade to act as a potential diagnostic marker or therapeutic target in brain tumor.

Isolated Internuclear Ophthalmoplegia After Massive Supratentorial Epidural Hematoma: A Case Report and Review of the Literature

BACKGROUND

Isolated internuclear ophthalmoplegia (INO) after traumatic brain injury (TBI) is rare, with most reported patients having minor head injuries. We report a patient with INO after a massive supratentorial epidural hematoma. We review the literature published since 1966, to summarize the mechanisms of injury and clinical outcomes of INO after TBI.

CASE DESCRIPTION AND LITERATURE REVIEW

A 54-year-old woman had isolated INO 10 hours after emergent evacuation of a massive supratentorial epidural hematoma. The brainstem displacement caused by downward herniation led to a deficient blood supply. Magnetic resonance imaging showed an infarct at the right dorsal-medial pons. Her symptoms partially improved by 1.5 months postoperatively. A total of 27 patients, including ours, with INO after TBI have been reported over the past 50 years. Young male patients (mean age, 30.8 years; male, 67%) are more common, and INO tends to be bilateral (67%). Infarction, hemorrhage, and fiber injury are nearly equally responsible for causing INO (35%, 35%, and 30%, respectively). Most patients recover spontaneously; 65% gain full recovery at a median time of 3 months, and 91% have at least partial recovery at 4.5 months. The median time for full recovery after infarct, hemorrhage, and fiber injury is 12, 90, and 150 days, respectively.

CONCLUSIONS

INO should be in the differential diagnosis of patients with TBI with an adduction deficit, despite the rarity of the condition. Isolated INO is a relatively benign sequela of TBI, with all but 1 reported patient achieving at least partial recovery over 12 months.

Thyroid hormone suppresses expression of stathmin and associated tumor growth in hepatocellular carcinoma

Stathmin (STMN1), a recognized oncoprotein upregulated in various solid tumors, promotes microtubule disassembly and modulates tumor growth and migration activity. However, the mechanisms underlying the genetic regulation of STMN1 have yet to be elucidated. In the current study, we report that thyroid hormone receptor (THR) expression is negatively correlated with STMN1 expression in a subset of clinical hepatocellular carcinoma (HCC) specimens. We further identified the STMN1 gene as a target of thyroid hormone (T₃) in the HepG2 hepatoma cell line. An analysis of STMN1 expression profile and mechanism of transcriptional regulation revealed that T₃ significantly suppressed STMN1 mRNA and protein expression, and further showed that THR directly targeted the STMN1 upstream element to regulate STMN1 transcriptional activity. Specific knockdown of STMN1 suppressed cell proliferation and xenograft tumor growth in mice. In addition, T₃ regulation of cell growth arrest and cell cycle distribution were attenuated by overexpression of STMN1. Our results suggest that the oncogene STMN1 is transcriptionally downregulated by T₃ in the liver. This T₃-mediated suppression of STMN1 supports the theory that T₃ plays an inhibitory role in HCC tumor growth, and suggests that the lack of normal THR function leads to elevated STMN1 expression and malignant growth.

De novo formation of cerebral cavernous malformation adjacent to existing developmental venous anomaly - an effect of change in venous pressure associated with management of a complex dural arterio-venous fistula

This is a case report of de novo development of two cerebral cavernous malformations adjacent to existing developmental venous anomalies. The development of cavernomas was noted over a follow-up period of 10 years. These developments happened during the course of staged endovascular management of a complex dural arterio-venous fistula along the right sphenoid wing. The patient presented with a proptosis secondary to lympho-haemangiomatous lesion of the fronto-orbital region and a high-flow right sphenoid wing dural arterio-venous fistula. During the initial period of conservative management of the dural arterio-venous fistula, he developed de novo cavernous malformations in the left mesial temporal lobe adjacent to a developmental venous anomaly in the temporal lobe, and along with this there was engorgement of deep veins related to another existing developmental venous anomaly in the brainstem. Later during the course of endovascular treatment of the dural arterio-venous fistula, a large brainstem cavernoma developed adjacent to the brainstem developmental venous anomaly. This case report discusses the cause-effect relationship of venous pressure changes related to management of dural arterio-venous fistula and de novo formation of cerebral cavernous malformations adjacent to existing developmental venous anomalies.

Chemotherapy resistance and metastasis-promoting effects of thyroid hormone in hepatocarcinoma cells are mediated by suppression of FoxO1 and Bim pathway

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide, and systemic chemotherapy is the major treatment strategy for late-stage HCC patients. Poor prognosis following chemotherapy is the general outcome owing to recurrent resistance. Recent studies have suggested that in addition to cytotoxic effects on tumor cells, chemotherapy can induce an alternative cascade that supports tumor growth and metastasis. In the present investigation, we showed that thyroid hormone (TH), a potent hormone-mediating cellular differentiation and metabolism, acts as an antiapoptosis factor upon challenge of thyroid hormone receptor (TR)-expressing HCC cells with cancer therapy drugs, including cisplatin, doxorubicin and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). TH/TR signaling promoted chemotherapy resistance through negatively regulating the pro-apoptotic protein, Bim, resulting in doxorubicin-induced metastasis of chemotherapy-resistant HCC cells. Ectopic expression of Bim in hepatoma cells challenged with chemotherapeutic drugs abolished TH/TR-triggered apoptosis resistance and metastasis. Furthermore, Bim expression was directly transactivated by Forkhead box protein O1 (FoxO1), which was negatively regulated by TH/TR. TH/TR suppressed FoxO1 activity through both transcriptional downregulation and nuclear exclusion of FoxO1 triggered by Akt-mediated phosphorylation. Ectopic expression of the constitutively active FoxO1 mutant, FoxO1-AAA, but not FoxO1-wt, diminished the suppressive effect of TH/TR on Bim. Our findings collectively suggest that expression of Bim is mediated by FoxO1 and indirectly downregulated by TH/TR, leading to chemotherapy resistance and doxorubicin-promoted metastasis of hepatoma cells.

Mitochondrial DNA variants as genetic risk factors for Parkinson disease

BACKGROUND AND PURPOSE

Investigation of the relationship between mitochondrial DNA (mtDNA) variants and Parkinson disease (PD) remains an issue awaiting more supportive evidence. Moreover, an affirming cellular model study is also lacking.

METHODS

The index mtDNA variants and their defining mitochondrial haplogroup were determined in 725 PD patients and 744 non-PD controls. Full-length mtDNA sequences were also conducted in 110 cases harboring various haplogroups. Cybrid cellular models, composed by fusion of mitochondria-depleted rho-zero cells and donor mitochondria, were used for a rotenone-induced PD simulation study.

RESULTS

Multivariate logistic regression analysis revealed that subjects harboring the mitochondrial haplogroup B5 have resistance against PD (odds ratio 0.50, 95% confidence interval 0.32-0.78; P = 0.002). Furthermore, a composite mtDNA variant group consisting of A10398G and G8584A at the coding region was found to have resistance against PD (odds ratio 0.50, 95% confidence interval 0.33-0.78; P = 0.001). In cellular studies, B4 and B5 cybrids were selected according to their higher resistance to rotenone, in comparison with cybrids harboring other haplogroups. The B5 cybrid, containing G8584A/A10398G variants, showed more resistance to rotenone than the B4 cybrid not harboring these variants. This is supported by findings of low reactive oxygen species generation and a low apoptosis rate in the B5 cybrid, whereas a higher expression of autophagy was observed in the B4 cybrid particularly under medium dosage and longer treatment time with rotenone.

CONCLUSIONS

Our studies, offering positive results from clinical investigations and cybrid experiments, provide data supporting the role of variant mtDNA in the risk of PD.

The Impact of Surgical Experience on Major Intraoperative Aneurysm Rupture and Their Consequences on Outcome: A Multivariate Analysis of 538 Microsurgical Clipping Cases

The incidence and associated mortality of major intraoperative rupture (MIOR) in intracranial aneurysm surgery is diverse. One possible reason is that many studies failed to consider and properly adjust the factor of surgical experience in the context. We conducted this study to clarify the role of surgical experience on MIOR and associated outcome. 538 consecutive intracranial aneurysm surgeries performed on 501 patients were enrolled in this study. Various potential predictors of MIOR were evaluated with stratified analysis and multivariate logistic regression. The impact of surgical experience and MIOR on outcome was further studied in a logistic regression model with adjustment of each other. The outcome was evaluated using the Glasgow Outcome Scale one year after the surgery. Surgical experience and preoperative Glasgow Coma Scale (GCS) were identified as independent predictors of MIOR. Experienced neurovascular surgeons encountered fewer cases of MIOR compared to novice neurosurgeons (MIOR, 18/225, 8.0% vs. 50/313, 16.0%, P = 0.009). Inexperience and MIOR were both associated with a worse outcome. Compared to experienced neurovascular surgeons, inexperienced neurosurgeons had a 1.90-fold risk of poor outcome. On the other hand, MIOR resulted in a 3.21-fold risk of unfavorable outcome compared to those without it. Those MIOR cases managed by experienced neurovascular surgeons had a better prognosis compared with those managed by inexperienced neurosurgeons (poor outcome, 4/18, 22% vs. 30/50, 60%, P = 0.013).

Corpus callosum involvement and postoperative outcomes of patients with gliomas

Corpus callosum involvement is associated with poorer survival in high grade glioma (HGG), but the prognostic value in low grade glioma (LGG) is unclear. To determine the prognostic impact of corpus callosum involvement on progression free survival (PFS) and overall survival (OS) in HGG and LGG, the records of 233 glioma patients treated from 2008 to 2011 were retrospectively reviewed. Preoperative magnetic resonance (MR) images were used to identify corpus callosum involvement. Age, sex, preoperative Karnofsky performance scale, postoperative Eastern Cooperative Oncology Group (ECOG) score and extent of resection (EOR) were evaluated with respect to PFS and OS. The incidence of corpus callosum involvement was similar among HGG (14 %) and LGG (14.5 %). Univariate analysis revealed that PFS and OS were significantly shorter in both WHO grade II and grade IV glioma with corpus callosum involvement (both, p < 0.05). Multivariate analysis showed that grade II glioma with corpus callosum involvement have shorter PFS (p = 0.03), while EOR, instead of corpus callosum involvement (p = 0.16), was an independent factor associated with PFS in grade IV glioma (p < 0.05). Corpus callosum involvement was no longer significantly associated with OS after adjusting age, gender, EOR, preoperative and postoperative performance status (p = 0.16, 0.17 and 0.56 in grade II, III and IV gliomas, respectively). Corpus callosum involvement happened in both LGG and HGG, and is associated with lower EOR and higher postoperative ECOG score both in LGG and HGG. Corpus callosum involvement tends to be an independent prognostic factor for PFS in LGG, but not for OS in LGG or in HGG.

Expression of high-mobility group box protein 1 in diabetic foot atherogenesis

The role of high mobility group box 1 (HMGB1) has been demonstrated in stroke and coronary artery disease but not in peripheral arterial occlusive disease (PAOD). The pathogenesis of HMGB1 in acute and chronic vascular injury is also not well understood. We hypothesized that HMGB1 induces inflammatory markers in diabetic PAOD patients. We studied 36 diabetic patients, including 29 patients with PAOD, who had undergone amputation for diabetic foot and 7 nondiabetic patients who had undergone amputation after traumatic injury. Expression of HMGB1 and inflammatory markers were quantified using immunohistochemical staining. Mitochondrial DNA copy number was quantified using real-time polymerase chain reaction. Compared with that in the traumatic amputation group, HMGB1 expression in vessels was significantly higher in the diabetes and diabetic PAOD groups. In all subjects, arterial stenosis grade was positively correlated with the expression levels of HMGB1, 8-hydroxyguanosine, malondialdehyde, vascular cell adhesion molecule 1, and inflammatory markers CD3, and CD68 in both the intima and the media of vessels. Furthermore, HMGB1 expression level was positively correlated with 8-hydroxyguanosine, vascular cell adhesion molecule 1, nuclear factor-kB, CD3, and CD68 expression. Within the PAOD subgroup, subjects with HMGB1 expression had higher expression of the autophagy marker LC3A/B and higher mitochondrial DNA copy number. HMGB1 may be an inflammatory mediator with roles in oxidative damage and proinflammatory and inflammatory processes in diabetic atherogenesis. Moreover, it may have dual effects by compensating for increased mitochondrial DNA copy number and increased autophagy marker expression.

Factors associated with poor outcome in patients with major intraoperative rupture of intracranial aneurysm

PURPOSE

This clinical study was conducted to evaluate factors affecting outcome in the cases following major intraoperative rupture (MIOR) of the intracranial aneurysms.

METHODS

Thirty cases with MIOR in a series of 467 surgeries for ruptured aneurysms were enrolled in this study. Clinical parameters, including: age, Hunt-Hess grading, Fisher grading, aneurysm size, aneurysm contour, operative timing, aneurysm location, and rupture timing were studied and compared with the prognosis in this particular cohort. The outcome was evaluated using the Glasgow Outcome Scale at least 3 months after surgery. Severe disability, vegetative survival, and death were classified as poor outcome.

RESULTS

Among the 30 cases with MIOR, 11 resulted in poor outcomes (36.7%). Age was an important prognostic factor in this cohort. Those patients with poor outcome after MIOR were significantly older than those with good outcome (mean age: 64.6 vs 51.4 years, P=0.006). In this study, a trend toward poor outcome was observed in cases with MIOR on internal carotid artery aneurysms (8/14, 57.1% vs 2/9, 22.2% and 1/6, 16.7% on middle cerebral artery and anterior communicating artery aneurysms, P=0.197, after adjustment for age factor). There was a higher incidence of a poor outcome when MIOR occurred during clip application (5/6, 83.3% vs 1/5, 20.0% and 5/19, 26.3% when MIOR happened during brain retraction and aneurysm dissection, P=0.041 after adjustment with the factor of age).

CONCLUSION

Although a larger sample population is required for a more conclusive result, MIOR occuring in older age, during clip application, or on an internal carotid artery aneurysm possibly has the trend to bear a worse outcome in the cohort of patients with MIOR during aneurysm surgery.

17β-Estradiol attenuates secondary injury through activation of Akt signaling via estrogen receptor alpha in rat brain following subarachnoid hemorrhage

BACKGROUND

Apoptosis is implicated in vasospasm and the long-term sequelae of subarachnoid hemorrhage (SAH). This study tested the hypothesis that attenuation of SAH-induced apoptosis after 17β-estradiol (E2) treatment is associated with an increase in phosphorylation of Akt via estrogen receptor-α (ER-α) in rats.

MATERIALS AND METHODS

We examined the expression of phospho-Akt, ERα and ERβ, and apoptosis in cerebral cortex, hippocampus, and dentate gyrus in a two-hemorrhage SAH model in rats. We subcutaneously implanted other rats with a silicone rubber tube containing E2; they received daily injections of nonselective estrogen receptor antagonist (ICI 182,780), selective ERα-selective antagonist (methyl-piperidino-pyrazole), or ERβ-selective antagonist (R,R-tetrahydrochrysene) after the first hemorrhage.

RESULTS

At 7 d after the first SAH, protein levels of phospho-Akt and ERα were significantly decreased and caspase-3 was significantly increased in the dentate gyrus. The cell death assay revealed that DNA fragmentation was significantly increased in the dentate gyrus. Those actions were reversed by E2 and blocked by ICI 182,780 and methyl-piperidino-pyrazole, but not R,R-tetrahydrochrysene. However, there were no significant changes in the expression of the protein levels of phospho-Akt, ERα, ERβ, and caspase-3, and DNA fragmentation after SAH.

CONCLUSIONS

The present study shows that a beneficial effect of E2 in attenuating SAH-induced apoptosis is associated with activation of the expression of phospho-Akt and ERα, and alteration in caspase-3 protein expression via an ERα-dependent mechanism in the dentate gyrus. These data support further the investigation of E2 in the treatment of SAH in humans.

Brain surgery in patients with liver cirrhosis

OBJECT

Liver cirrhosis was identified as an independent predictor of poor outcomes in patients suffering trauma and in those undergoing major surgeries. The aim of this study was to report the authors' experiences treating patients with cirrhosis who undergo brain surgeries.

METHODS

Between 2004 and 2009, 121 consecutive patients with cirrhosis underwent 144 brain procedures. Patients were categorized as Child-Turcotte-Pugh (referred to as "Child") Class A, B, or C. The patient profiles, including the severity of cirrhosis, reason for surgery, complications, and prognosis factors, were analyzed.

RESULTS

In this retrospective study, the overall surgical complication rate for patients with cirrhosis was 52.1% and the mortality rate was 24.3%. For patients with acute traumatic brain injury (TBI), the complication, rebleeding, and mortality rates reached 84.4%, 68.8%, and 37.5%, respectively. Surgery for TBI was a significant risk factor for postoperative complications (p = 0.0002) and postoperative hemorrhage (p < 0.0001). Otherwise, according to the Child classification, the complication rate increased in a stepwise fashion from 38.7% to 60% to 84.2%, the rebleeding rate from 29.3% to 48.0% to 63.2%, and the mortality rate from 5.3% to 38% to 63.2% for Child A, B, and C, respectively. The Child classification was associated with higher risk of complications-Child B vs A OR 2.84 (95% CI 1.28-6.29), Child C vs A OR 5.39 (95% CI 1.32-22.02). It was also associated with risk of death-Child C vs A OR 30.43 (95% CI 7.71-120.02), Child B vs A OR 10.88 (95% CI 3.42-34.63).

CONCLUSIONS

Liver cirrhosis is a poor comorbidity factor for brain surgery. The authors' results suggest that the Child classification used independently is a poor prognostic factor; in addition, grave outcomes were observed in patients with TBI.

Solitary intradural extramedullary metastasis of renal cell carcinoma to the conus medullaris

We report the case of a 68-year-old man with a 6-year history of renal cell carcinoma (RCC), who presented with severe low backache and paraparesis for a month before admission. In addition, he experienced urinary retention for 2 weeks. A spinal magnetic resonance imaging scan revealed the presence of an intradural extramedullary solitary mass at the conus medullaris. We performed a laminectomy and completely excised the tumor. The histopathological findings were suggestive of spinal metastasis of RCC. After the operation, the patient did not complain of backache and urinary retention, and paraparesis improved significantly. Spinal metastases of RCC are usually extradurally located. Intradural metastases of RCC are rare. Thus far, only six cases of RCC metastasizing to the cauda equina have been reported; however, RCC metastasis to the conus medullaris has not yet been reported. Conus medullaris lesions may cause symmetrical motor and sensory deficits accompanied by early autonomic system impairment. Surgery is the treatment of choice in cases of resectable RCC metastases, especially in cases of solitary metastasis.

A concise guideline for the management of large hemispheric infarction in Taiwan: 2010 update: a guideline from the Taiwan Stroke Society

In this report, we present comprehensive recommendations for the diagnosis and treatment of large hemispheric infarction (LHI). A systematic literature search was conducted until June 30, 2010. The American Heart Association Stroke Council's Levels of Evidence grading algorithm was used to grade each recommendation (Table 1). The guideline was revised after several official meetings with local experts, and was reviewed by 3 expert reviewers. Early diagnosis of malignant large hemispheric infarction (MLHI) is critical. Studies have shown that using computed tomography (CT) or transcranial sonography to track midline shifting of the cerebrum and applying diffusion-weighted magnetic resonance imaging might contribute to the early recognition of MLHI. Glycerol and mannitol should be administered only when a patient shows evidence of brain edema or mass effect. The effect of barbiturate coma on improving prognosis is inconclusive and requires close monitoring of the patient. Meanwhile, using steroids on patients with stroke is not recommended. The effect of hyperventilation on reducing intracranial pressure is rapid but short-lived, and is used only in emergency situations. The target levels of PaCO2 are 30-35 mmHg. Moderate hypothermia (32-34°C) may be effective in controlling intracranial hypertension, but should be used cautiously along with rigorous monitoring. Timely decompressive craniectomy can probably offer patients a better chance of survival and quality of life. Usually, surgery for MLHI is indicated in patients with clinical deterioration associated with a significant mass effect, as observed on neuroimaging. However, with a reliable indicator of MLHI, early decompressive craniectomy before clinical deterioration may further reduce mortality and lead to a better functional outcome.

Interhemispheric comparisons of cerebral blood flow velocity changes during mental tasks with transcranial Doppler sonography

OBJECTIVE

The purpose of this study was to evaluate hemispheric asymmetry of cerebral blood flow changes during various mental tests by applying transcranial Doppler sonography (TCD) to simultaneously monitor bilateral cerebral blood flow velocity changes.

METHODS

Twenty-one participants without cerebrovascular disease performed 3 left hemispheric tasks (reading, calculation, and color scaling) and 3 right hemispheric tasks (face recognition, space imagination, and line orientation).

RESULTS

Mean velocities of the rest and performing periods did not differ significantly between the left and right hemispheric tasks. Although greater acceleration of blood flow velocity was observed on the left than on the right in most of the 6 tasks except line orientation (mean left - right ratio difference [D(l-r)] ranged from -0.018 to 0.071), this difference was larger for left hemispheric tasks (mean D(l-r) ranged from 0.050 to 0.071) than right hemispheric tasks (mean D(l-r) ranged from -0.018 to 0.034; P < .001). Further comparisons of each pair of (ie, left and right) hemispheric tasks revealed that the most suitable left and right hemispheric tasks to show hemispheric asymmetry were reading and line orientation, respectively (P < .001).

CONCLUSIONS

Hemispheric asymmetry of cerebral blood flow changes during mental tests is demonstrable with TCD only when comparing the D(l-r) in response to suitable paired left and right hemispheric tasks.

Surgical treatment of spontaneous spinal epidural hematoma: a 5-year experience

Object

Spontaneous spinal epidural hematoma (SSEH) is a rare disease. The goal of this study was to clarify the treatment results and management options in SSEH.

Methods

Patients with SSEH who were surgically treated in the authors' center between June 2003 and June 2008 were included in this study. Patients were treated as early as possible if their neurological deficits were incomplete or had been complete for 12 hours or less. The patients were assigned to 1 of 2 groups based on completeness of preoperative cord dysfunction (complete vs incomplete deficit). Surgical outcomes of the 2 groups were compared by functional performance, coded as Nurick grades at 1, 3, and 6 months after the operation. Also compared were duration of hospital stay and the number of days needed to regain the ability to function independently (defined as Nurick Grades 1 and 2) after the operation.

Results

There were 17 patients (7 female and 10 male) with pathologically confirmed SSEH. Coagulopathy, greater size (length) of SSEH, and preoperative complete spinal dysfunction were found to contribute to poor postoperative functional recovery (p < 0.05). Patients with incomplete preoperative deficits (ASIA Impairment Scale Grades B, C, and D) were able to achieve functional independent recovery within a month after surgery and had significantly better outcomes (lower Nurick grades) at 1, 3, and 6 months postoperatively than those with complete deficits (p < 0.001, p = 0.027, and p = 0.027, respectively). Median time to independent functional recovery and median length of hospital stay were significantly shorter in patients with incomplete preoperative deficits than in those with complete deficits (6 vs 110 and 9 vs 58 days, respectively; both p < 0.001).

Conclusions

Impaired preoperative hemostasis contributes to larger size of SSEH, high probability of postoperative recurrence of spinal epidural hematoma, and poor functional recovery following surgical evacuation. Incomplete spinal cord dysfunction before surgery predicts good outcome and warrants emergent evacuation of SSEH especially in the cervical and thoracic regions, where the clots are located in proximity to the spinal cord.

Stereotactic brain biopsy: Single center retrospective analysis of complications

OBJECTIVE

Stereotactic biopsy is a widely used surgical technique for the histological diagnosis of intracranial lesions. Potential risks of this procedure, such as hemorrhage, seizure, and infection have been established, and different risk factors have been characterized. However, these risks have been addressed by only few studies conducted in Asian countries.

MATERIALS AND METHODS

The study group is comprised of 299 consecutive stereotactic biopsy procedures by 11 neurosurgeons between 2004 and 2007. The pre-operative medical conditions, methods of biopsy and postoperative complications were analyzed.

RESULT

The overall diagnostic yield was 90.64%. Complications were observed in 7.36% of the cases, with symptomatic hemorrhages occurring in 4.35% of the cases, and the overall mortality rate in this study population was 1.34%. Patients with liver cirrhosis were at a higher risk of hemorrhage. Other clinical, radiological, or histological variables were not associated with an increased risk of complications.

CONCLUSION

Stereotactic brain biopsy is a safe and reliable way to obtain a histological diagnosis. Based on our recent clinical experiences, the data suggests that more attention should be paid to liver cirrhotic patients, since the chance on hemorrhage is significantly larger.

Voriconazole in the treatment of fungal eye infections: a review of current literature

BACKGROUND

Voriconazole has an important role to play in the prophylaxis and management of fungal endophthalmitis and keratitis. New-generation triazoles, including voriconazole, posaconazole and ravuconazole, have been shown in laboratory studies and clinical experience to have very good safety profiles with few side effects. Fungal eye infections, while not common in temperate climates, have been notoriously difficult to diagnose and treat, and generally result in protracted therapy with poor final outcomes. Current treatment options are far from optimal.

AIMS

This paper will review studies and clinical case reports published in the ophthalmic literature that address the safety of these drugs in the eye, penetration and concentration in ocular tissues and media, and efficacy in treating common pathogens implicated in fungal keratitis and endophthalmitis.

CONCLUSIONS

Over 40 clinical case reports of treatment with voriconazole suggest that it may be used safely and effectively against a broad range of fungal pathogens.

Upregulation of nitric oxide synthase II contributes to apoptotic cell death in the hippocampal CA3 subfield via a cytochrome c/caspase-3 signaling cascade following induction of experimental temporal lobe status epilepticus in the rat

Status epilepticus results in preferential neuronal cell loss in the hippocampus. We evaluated the hypothesis that the repertoire of intracellular events in the vulnerable hippocampal CA3 subfield after induction of experimental temporal lobe status epilepticus entails upregulation of nitric oxide synthase II (NOS II), followed by the release of mitochondrial cytochrome c that triggers the cytosolic caspase-3 cascade, leading to apoptotic cell death. In Sprague-Dawley rats, significant and temporally correlated upregulation of NOS II (3-24h), but not NOS I or II expression, enhanced cytosolic translocation of cytochrome c (days 1 and 3), augmented activated caspase-3 in cytosol (days 1, 3 and 7) and DNA fragmentation (days 1, 3 and 7) was detected bilaterally in the hippocampal CA3 subfield after elicitation of sustained seizure activity by microinjection of kainic acid into the unilateral CA3 subfield. Application bilaterally into the hippocampal CA3 subfield of a selective NOS II inhibitor, S-methylisothiourea, significantly blunted these apoptotic events; a selective NOS I inhibitor, N(omega)-propyl-l-arginine or a potent NOS III inhibitor, N(5)-(1-iminoethyl)-l-ornithine was ineffective. We conclude that upregulation of NOS II contributes to apoptotic cell death in the hippocampal CA3 subfield via a cytochrome c/caspase-3 signaling cascade following the induction of experimental temporal lobe status epilepticus.

Increased levels of F2-isoprostanes following aneurysmal subarachnoid hemorrhage in humans

Subarachnoid hemorrhage (SAH) resulting from aneurysmal rupture is the major cause of nontraumatic SAH. We hypothesized that oxidative stress could be increased following aneurysmal SAH due to hemoglobin release and ischemia-reperfusion injury and that may further contribute to poor outcome. We collected plasma and cerebrospinal fluid (CSF) samples from 11 non-SAH controls and 15 aneurysmal SAH patients for up to 10 days after surgery and investigated status of oxidative stress in patients. Results showed that mean or peak levels of F(2)-isoprostanes (F(2)-IsoPs), a specific marker of lipid peroxidation, and total nitrate/nitrite, metabolites of nitric oxide and peroxynitrite, in CSF and plasma were significantly higher in SAH patients than in controls. First-day levels were also higher in CSF, but not in plasma, in SAH patients. Moreover, mean and peak levels of CSF F(2)-IsoPs were positively correlated with poor outcome or severity of clinical conditions in patients. Furthermore, levels of retinol, delta-tocopherol, beta+gamma-tocopherol, lutein, beta-carotene, and coenzyme Q(10) in plasma were significantly lower in SAH patients than in controls. Our results indicate that oxidative damage may play important roles in the severity and complications of aneurysmal SAH and suggest that means to suppress lipid peroxidation may be beneficial in improving the outcome of aneurysmal SAH.

Solitary intraventricular tuberculoma in adults

Intracranial tuberculoma is typically located in the parenchyma. Lesions limited to the ventricular system are uncommon. It is difficult to make a differential diagnosis from other lesions if no systemic tuberculosis is present. This study investigates a case of solitary intraventricular tuberculoma in a 19-year-old female patient with an initial clinical symptom of progressive headache. Cranial computed tomography revealed a strongly enhanced lesion in the lateral ventricle. Histopathology of the tumor demonstrated chronic inflammation, caseous necrosis, epithelioid cells and Langhans' giant cell. The culture study grew M. Tuberculosis. Solitary intraventricular tuberculoma in adults is extremely rare. Medical treatment is the preferred management method of this disease, and surgical intervention should be considered in certain situations.

Fourth ventricle central neurocytoma: case report

OBJECTIVE AND IMPORTANCE

Central neurocytomas (CNs) are typically located in the lateral ventricle. Primary origins in the fourth ventricle are very rare. We discuss the clinical symptoms, imaging findings, and microscopic features of these rare tumors.

CLINICAL PRESENTATION

We report a case of a fourth ventricle CN in a 35-year-old male patient with the initial symptoms of progressive headaches and blurred vision for more than 2 months. Computed tomography and magnetic resonance imaging of the brain revealed a slightly enhanced tumor in the fourth ventricle, with obstructive hydrocephalus.

INTERVENTION

Total surgical removal of the tumor was performed. The tumor was initially diagnosed as an oligodendroglioma. The final definitive diagnosis as a CN was made after special immunohistochemical studies.

CONCLUSION

CNs located in the fourth ventricle are extremely rare. Immunohistochemical stains and transmission electron microscopy can provide useful diagnostic information. Total tumor excision is associated with favorable prognoses. Postoperative radiotherapy may be considered for cases of subtotal excision, anaplastic histological variants, or recurrent tumors.

Generalized argyria in two chronic hemodialysis patients

Silver can be absorbed through ingestion, topical administration, or inhalation. Generalized argyria results from deposition of silver in the skin, nails, mucous membranes, and internal organs and is characterized by a diffuse bluish-gray discoloration in sun-exposed areas. We report two cases of generalized argyria in patients on maintenance hemodialysis (HD) therapy for more than 15 years. They presented with diffuse hyperpigmentation of the face that was mistaken to be related to uremia and bluish-gray discoloration of all nails believed to be cyanosis. Histopathologic examination of skin biopsy specimens showed characteristic findings of argyria, which was further confirmed by radiograph microanalysis. Their serum silver levels were also elevated. No definite silver source could be determined. However, their argyria might be related to their long-term HD therapy because (1) they had been on HD therapy for more than 15 years and the discoloration appeared several years afterward, and (2) the water used for HD was not well processed in the early 1980s in TAIWAN: Argyria should be suspected in chronic HD patients presenting with a diffuse bluish-gray discoloration of the skin and nails and evaluated carefully by skin biopsy.

Prophylactic esmolol infusion for the control of cardiovascular responses to extubation after intracranial surgery

INTRODUCTION

Emergence from general anaesthesia and extubation are often accompanied by significant surges in heart rate and blood pressure. To document these changes and the efficacy of low-dose beta-blocker infusions in ameliorating these rises, we undertook a descriptive dose-ranging study comparing the use of esmolol to placebo in patients emerging from neuro-anaesthesia.

MATERIALS AND METHODS

Thirty-six patients undergoing intracranial surgery were randomised to receive saline, esmolol 100 micrograms/kg/min or 200 micrograms/kg/min infusions. The number of patients developing severe hypertension or tachycardia in each group was compared using Fisher's exact test.

RESULTS

Systolic blood pressure (SBP) and heart rate (HR) increased in all 3 groups during emergence and peaked at extubation. The proportion of patients with severe tachycardia or hypertension was reduced from 92% in the placebo group to 40% (P = 0.02) and 8% (P = 0.001) in the low and intermediate dose esmolol groups, respectively. Results were better in the intermediate dose group but the difference was not statistically significant. Two patients from the esmolol infusion groups required supplemental medication for bradycardia.

CONCLUSION

Severe hypertension or tachycardia occurs in 92% of patients during extubation following neuro-anaesthesia and warrants the consideration of routine prophylaxis. Prophylactic esmolol infusion for the control of haemodynamic disturbances during extubation is feasible and safe. A modest level of obtundation is evident at 100 micrograms/kg/min but a rate of 200 micrograms/kg/min may prove to be more effective.

Mitochondrially targeted antioxidants and thiol reagents

Mitochondrial oxidative damage and dysfunction contributes to a number of cell pathologies. To investigate how this damage affects cell function we have developed mitochondrially targeted antioxidants and thiol reagents by covalently linking them to lipophilic cations. The cation drives the selective accumulation of these reagents into mitochondria within cells where the antioxidants decrease oxidative damage and the thiol reagents enable measurement of the redox status of thiol proteins. In conjunction with cell and animal models of apoptosis, oxidative damage, and nitric oxide signaling, these molecules may provide new insights into the roles of mitochondria in human pathologies.

Unusual dilatation of Virchow-Robin spaces: case report

Virchow-Robin spaces normally surround the perforating arteries that enter the brain. These spaces are a well-defined sites where immunological reactions take place and they may have implications in the pathogenesis of a number of neuropathological conditions. We present the case of a 52-year-old woman who had a history of complex partial seizures for 30 years. Her routine neurological examinations and mini-mental tests had normal results. Magnetic resonance images of this patient revealed unusual widening of the Virchow-Robin spaces up to 1.5 cm in diameter along the perforating medullary arteries in the white matter, more so in the left hemisphere. Although it has been concluded that these large spaces are a phenomenon of the normal aging brain and are unrelated to neurological diseases, our patient had had epileptic seizures for 30 years. The large Virchow-Robin spaces of our patient might have been an incidental radiologic finding. Their pathogenesis remains unclear, and their possible clinical relationship to epilepsy deserves further pathological studies.

Hemodynamic abnormalities in sodium monofluoroacetate intoxication

Hypotension is one of the most important predictors of mortality in sodium monofluoroacetate (SMFA) intoxication. This paper reports the hemodynamic response in one fatal and another survival case of SMFA intoxication. Despite correction of hypovolemia and with inotropic support, the patients remained in shock. Hemodynamic observations have provided evidence that shock after SMFA intoxication is due to diminished systemic vascular resistance and increased cardiac output. This is the first report in which such an invasive hemodynamic investigation has been recorded in a clinical case of SMFA intoxication.

Osmotic demyelination syndrome with two-phase movement disorders: case report

Osmotic demyelination syndrome (ODS) is characterized by regions of demyelination throughout the brain, which are most prominent in the pons. This demyelinating disease is associated with electrolyte disturbances and typically occurs in patients who are alcoholic or malnourished. Movement disorders are not frequently recognized in patients with ODS. This report describes a 22-year-old woman with ODS after correction of profound hyponatremia. The main neurologic symptom was two-phase movement disorder. First, she had acute onset dystonia, then the movement disorder transformed to generalized rigidity and tremors in the delayed second phase. Magnetic resonance imaging in the first phase revealed demyelinating lesions in the central pons, bilateral thalami and basal ganglia. In the second phase, the previous myelinolysis had been partially resolved. The clinical course of the two-phase movement disorder did not correlate with the resolving feature of neuroradiologic findings. During the second-phase movement disorder, the patient had a good response to propranolol and trihexyphenidyl.