Comparison of Clinical Outcomes of Intracranial Aneurysms: Procedural Rupture versus Spontaneous Rupture.

BACKGROUND AND PURPOSE: Procedural rupture of an intracranial aneurysm is a devastating complication in endovascular treatment. The purpose of this study was to evaluate the clinical outcomes of patients with procedural rupture of unruptured saccular intracranial aneurysms compared with those with spontaneously ruptured aneurysms. MATERIALS AND METHODS: A retrospective review was performed for 1340 patients with 1595 unruptured saccular intracranial aneurysms that underwent endovascular coil embolization between February 2010 and December 2014. The clinical outcomes of patients with procedural rupture of unruptured saccular intracranial aneurysms were compared with those of 198 patients presenting with spontaneously ruptured aneurysms. RESULTS: In this series, procedural rupture developed in 19 patients (1.4% per patient and 1.2% per aneurysm), and the morbidity related to procedural rupture was 26.3% (95% confidence interval, 8.5%-61.4%) with no mortality. Hunt and Hess scale grades and hospitalization days of patients with procedural rupture were equivalent to those of patients presenting with spontaneous aneurysm rupture. Subsequent treatment procedures after hemorrhage (including lumbar drainage, extraventricular drainage, decompressive craniectomy, and permanent shunt) showed no difference between the 2 groups. The hemorrhage volumes were smaller in the procedural-rupture group (P = .03), and the endovascular vasospasm therapies tended to be more frequently required in the spontaneous aneurysm-rupture group (P = .08). At postictus 6 months, the proportion of modified Rankin Scale scores of ≥2 were lower in the procedural-rupture group (5.3% versus 26.8%, P = .049). In multivariate analysis, spontaneous aneurysm rupture was a significant risk factor for worse clinical outcome (OR = 14.9; 95% CI, 1.2-193.1; P = .039). CONCLUSIONS: This study showed better clinical outcomes in the procedural-rupture group. Even though there is a potential chance of aneurysm rupture during treatment, the clinical outcomes after procedural bleeds seem to be more favorable than those of spontaneous rupture.

Prophylactic Antiplatelet Medication in Endovascular Treatment of Intracranial Aneurysms: Low-Dose Prasugrel versus Clopidogrel.

BACKGROUND AND PURPOSE: Prophylactic antiplatelet medication is beneficial in decreasing thromboembolic complications during endovascular treatment of unruptured intracranial aneurysms. The efficacy may be limited by variability of individual response to antiplatelet medication, especially clopidogrel. We compared the efficacy of 2 antiplatelet medications, low-dose prasugrel and clopidogrel, in patients undergoing endovascular treatment of unruptured aneurysms. MATERIALS AND METHODS: From November 2014 to July 2015, 194 patients with a total of 222 unruptured aneurysms underwent endovascular treatment at a single institution. Laboratory and clinical data from the prospectively maintained registry were used in this study. Antiplatelet medication was given the day before endovascular treatment (prasugrel 20 mg or 30 mg or clopidogrel 300 mg). Response to the antiplatelet medication was measured by the VerifyNow system. Periprocedural adverse event rates between the 2 groups were compared. RESULTS: There were no significant differences in the baseline characteristics of patients and aneurysms between the 2 groups. The P2Y12 reaction unit values were lower (clopidogrel group versus prasugrel group, 242.7 ± 69.8 vs 125.7 ± 79.4; P < .0001) and percentage inhibition values were higher (22.1% ± 19.7% vs 60.2 ± 24.7%; P < .0001) in the prasugrel group. There were no thromboembolic events, but there was 1 procedural bleed in each group, without any clinical consequences. CONCLUSIONS: The prasugrel group showed more effective and consistent platelet inhibition. We may omit the antiplatelet response assay with the low-dose prasugrel premedication before the endovascular treatment of patients with unruptured aneurysms. Further study is required to determine whether there is benefit of this strategy regarding clinical outcome.

CHK2 kinase promotes pre-mRNA splicing via phosphorylating CDK11(p110).

Checkpoint kinase 2 (CHK2) kinase is a key mediator in many cellular responses to genotoxic stresses, including ionizing radiation (IR) and topoisomerase inhibitors. Upon IR, CHK2 is activated by ataxia telangiectasia mutated kinase and regulates the S-phase and G1-S checkpoints, apoptosis and DNA repair by phosphorylating downstream target proteins, such as p53 and Brca1. In addition, CHK2 is thought to be a multi-organ cancer susceptibility gene. In this study, we used a tandem affinity purification strategy to identify proteins that interact with CHK2 kinase. Cyclin-dependent kinase 11 (CDK11)(p110) kinase, implicated in pre-mRNA splicing and transcription, was identified as a CHK2-interacting protein. CHK2 kinase phosphorylated CDK11(p110) on serine 737 in vitro. Unexpectedly, CHK2 kinase constitutively phosphorylated CDK11(p110) in a DNA damage-independent manner. At a molecular level, CDK11(p110) phosphorylation was required for homodimerization without affecting its kinase activity. Overexpression of CHK2 promoted pre-mRNA splicing. Conversely, CHK2 depletion decreased endogenous splicing activity. Mutation of the phosphorylation site in CDK11(p110) to alanine abrogated its splicing-activating activity. These results provide the first evidence that CHK2 kinase promotes pre-mRNA splicing via phosphorylating CDK11(p110).

COP9 signalosome subunit 6 stabilizes COP1, which functions as an E3 ubiquitin ligase for 14-3-3σ.

14-3-3σ, a gene upregulated by p53 in response to DNA damage, exists as part of a positive-feedback loop, which activates p53 and is a human cancer epithelial marker downregulated in various cancer types. 14-3-3σ levels are critical for maintaining p53 activity in response to DNA damage and regulating signal mediators such as Akt. In this study, we identify mammalian constitutive photomorphogenic 1 (COP1) as a novel E3 ubiquitin ligase for targeting 14-3-3σ through proteasomal degradation. We show for the first time that COP9 signalosome subunit 6 (CSN6) associates with COP1 and is involved in 14-3-3σ ubiquitin-mediated degradation. Mechanistic studies show that CSN6 expression leads to stabilization of COP1 through reducing COP1 self-ubiquitination and decelerating COP1's turnover rate. We also show that CSN6-mediated 14-3-3σ ubiquitination is compromised when COP1 is knocked down. Thus, CSN6 mediates 14-3-3σ ubiquitination through enhancing COP1 stability. Subsequently, we show that CSN6 causes 14-3-3σ downregulation, thereby activating Akt and promoting cell survival. Also, CSN6 overexpression leads to increased cell growth, transformation and promotes tumorigenicity. Significantly, 14-3-3σ expression can correct the abnormalities mediated by CSN6 expression. These data suggest that the CSN6-COP1 axis is involved in 14-3-3σ degradation, and that deregulation of this axis will promote cell growth and tumorigenicity.

Sp1 mediates repression of the resistin gene by PPARgamma agonists in 3T3-L1 adipocytes.

Resistin is an adipokine related to obesity and insulin resistance. Expression of the resistin gene is repressed by the treatment of peroxisome proliferator-activated receptor gamma (PPARgamma) agonists, thiazolidinediones (TZDs). In this study, we investigated the mechanism by which TZDs inhibit the resistin gene expression. Resistin gene expression was decreased by TZD in fully differentiated 3T3-L1 adipocytes, which was abolished after treatment of cycloheximide (a protein synthesis inhibitor). TZD could not repress the expression of the resistin gene in the presence of mithramycin A (an Sp1 binding inhibitor). Sp1 binding site of the resistin promoter (-122/-114bp) was necessary for the repression. Further investigation of the effect of TZDs on the modification of Sp1 showed that the level of O-glycosylation of Sp1 was decreased in this process. These results suggest that PPARgamma activation represses the expression of the resistin gene by modulating Sp1 activity.

Regulation of human resistin gene expression in cell systems: an important role of stimulatory protein 1 interaction with a common promoter polymorphic site.

AIMS/HYPOTHESIS: Resistin is an adipokine that might link obesity and insulin resistance. A common polymorphism of the human resistin gene, -420C >G, is a major determinant of plasma resistin concentrations as well as resistin mRNA expression in human adipose tissue. In this study, we investigated the regulatory mechanism by which this polymorphism affects resistin expression. METHODS: Electrophoretic mobility shift assay was performed to identify the transcription factors binding to the -420G region. Transient transfection and reporter assay were used to measure promoter activities of the resistin gene. The binding ability of stimulatory protein 1 (Sp1) in response to adipocyte differentiation or high glucose concentrations was also measured. RESULTS: Sp1 and stimulatory protein 3 (Sp3) specifically bound to the region around -420G of the human resistin gene. Overexpression of Sp1 increased the promoter activity regardless of -420 genotypes, while the promoter activity of the -420G construct was two-fold higher than that of the -420C construct. In contrast, overexpression of Sp3 scarcely increased the promoter activity. The binding ability of Sp1 to the -420G region was increased in response to adipocyte differentiation. Mithramycin A, an inhibitor of DNA binding of Sp1, reduced the effect of high glucose on transcription induction of the resistin gene in adipocytes. CONCLUSIONS/INTERPRETATION: These results suggest that Sp1 is an important factor regulating transcription of human resistin gene. A common polymorphism of the human resistin promoter, -420C >G, is critical for the binding of Sp1 and modulates the transcriptional activity of the resistin gene by changing the binding ability of Sp1. In addition, Sp1 may be involved in the increase of resistin expression by hyperglycaemia.

Effects of testosterone replacement in human immunodeficiency virus-infected women with weight loss.

The objective of this study was to determine whether physiological testosterone replacement increases fat-free mass (FFM) and muscle strength and contributes to weight maintenance in HIV-infected women with relative androgen deficiency and weight loss. Fifty-two HIV-infected, medically stable women, 18-50 yr of age, with more than 5% weight loss over 6 months and testosterone levels below 33 ng/dl were randomized into this double-blind, placebo-controlled trial of 24-wk duration. Subjects in the testosterone group applied testosterone patches twice weekly to achieve a nominal delivery of 300 mug testosterone over 24 h. Data were evaluable for 44 women. Serum average total and peak testosterone levels increased significantly in the testosterone group, but did not change in the placebo group. However, there were no significant changes in FFM (testosterone, 0.7 +/- 0.4 kg; placebo, 0.3 +/- 0.4 kg), fat mass (testosterone, 0.3 +/- 0.7 kg; placebo, 0.6 +/- 0.7 kg), or body weight (testosterone, 1.0 +/- 0.9 kg; placebo, 0.9 +/- 0.8 kg) between the two treatment groups. There were no significant changes in leg press strength, leg power, or muscle fatigability in either group. Changes in quality of life, sexual function, cognitive function, and Karnofsky performance scores did not differ significantly between the two groups. High-density lipoprotein cholesterol levels decreased significantly in the testosterone group. The patches were well tolerated. We conclude that physiological testosterone replacement was safe and effective in raising testosterone levels into the mid to high normal range, but did not significantly increase FFM, body weight, or muscle performance in HIV-infected women with low testosterone levels and mild weight loss. Additional studies are needed to fully explore the role of androgens in the regulation of body composition in women.

Cardiac Characteristics of Transgenic Mice Overexpressing Refsum Disease Gene-Associated Protein within the Heart.

Arrhythmia is a common cardiac symptom of Refsum disease. Recently, we identified a novel neuron-specific PAHX-associated protein (PAHX-AP1), which binds to the Refsum disease gene (PAHX). In this report, we developed heart-targeted transgenic (TG) mice under the control of alpha-myosin heavy chain promoter to determine whether cardiac overexpression of PAHX-AP1 provokes cardiac involvement symptoms. Northern and in situ hybridization analyses revealed PAHX-AP1 transcript was overexpressed in TG atrium, especially in the sinoatrial node. TG mice showed tachycardia, and tachyarrhythmia was observed in 20% of TG mice. Isolated TG atria showed higher frequency beating and were more sensitive to aconitine-induced tachyarrhythmia than the wild-type, and 40% of the TG atria showed irregular beating. Action potential duration in TG atrial fiber was shortened much more than the wild-type. Systemic administration of arrhythmogenic agents induced arrhythmia in TG mice, while no arrhythmia with the same dose in nonTG mice. Our results indicate that the chronic atrial tachycardia by overexpressed neuron-specific PAHX-AP1 transgene in atrium may be responsible for the increased susceptibility to arrhythmia.

Transcriptional silencing of Cyclooxygenase-2 by hyper-methylation of the 5' CpG island in human gastric carcinoma cells.

It has been well established that overexpression of Cyclooxygenase-2 (Cox-2) in epithelial cells inhibits apoptosis and increases the invasiveness of malignant cells, favoring tumorigenesis and metastasis. However, the molecular mechanism that regulates Cox-2 expression has not been well defined in gastric carcinoma. In this study, we examined whether the Cox-2 expression could be regulated by hyper-methylation of the Cox-2 CpG island (spanning from -590 to +186 with respect to the transcription initiation site) in human gastric carcinoma cell lines. By Southern analysis, we found that three gastric cells (SNU-601, -620, and -719) without Cox-2 expression demonstrated hyper-methylation at the Cox-2 CpG island. A detailed methylation pattern using bisulfite sequencing analysis revealed that all of the CpG sites were completely methylated in SNU-601. Treatment with demethylating agents effectively reactivated the expression of Cox-2 and restored IL-1beta sensitivity in the previously resistant SNU-601. By transient transfection experiments, we demonstrate that constitutively active Cox-2 promoter activities were exhibited even without an exogenous stimulation in SNU-601. Furthermore, when the motif of the nuclear factor for interleukin-6 expression site, the cyclic AMP response element, or both was subjected to point mutation, the constitutive luciferase activity was markedly reduced. In addition, Cox-2 promoter activity was completely blocked by in vitro methylation of all of the CpG sites in the Cox-2 promoter region with SssI (CpG) methylase in SNU-601. Taken together, these results indicate that transcriptional repression of Cox-2 is caused by hyper-methylation of the Cox-2 CpG island in gastric carcinoma cell lines.

Video assisted thoracoscopic ligation of patent ductus arteriosus. Technique of sliding loop ligation.

Variant video-assisted thoracoscopic surgical technique for closure of patent ductus arteriosus has been introduced. Although the endoscopic clipping device may be a preferred method for interruption of the patent ductus arteriosus, there is always the risk of inadequate clip placement and limitation of application in width of ductus arteriosus. In an effort to overcome this problem we have used a self-made endoscopic loop ligation in 10 patients and herein report the method. Only a small window and one port of access are necessary to dissect the patent ductus arteriosus from the surrounding tissues and to apply the extracorporeally created sliding loop. Successful ligation without shunt is obtained in all cases. The technique is simple and safe even in the presence of a wide ductus.

Methylation of specific CpG sites in the promoter region could significantly down-regulate p16(INK4a) expression in gastric adenocarcinoma.

Silencing of p16(INK4a) by methylation of the CpG islands in the promoter region has been found to be an alternative mechanism of inactivation in several tumors. However, in gastric carcinoma, the relationship between methylation status and the transcriptional silencing of the p16 gene remains to be clarified. In this study, we investigated whether methylation of a few specific CpG sites in the promoter region could significantly down-regulate p16 activity in the tumorigenesis of gastric carcinoma. By Southern analysis and bisulfite-modified genomic sequencing of 9 gastric-carcinoma cell lines, we found that the 5 cell lines (55.5%) not expressing p16 mRNA had methylated CpG sites at the promoter region of p16. In addition, we analyzed the p16-protein expression of 28 primary gastric carcinomas and their normal counterparts by immunohistochemical staining (IHC) on paraffin sections. Loss of p16 expression was detected in 6 cases (22%). In 5 out of these 6 (83%), the actual p16 gene was inactivated by de novo methylation of the promoter sites. Taken together, these results suggest a strong correlation between de novo methylation of a few specific CpG sites and transcriptional silencing of the p16 gene in gastric carcinoma.

Transcriptional inactivation of the tissue inhibitor of metalloproteinase-3 gene by dna hypermethylation of the 5'-CpG island in human gastric cancer cell lines.

The tissue inhibitor of metalloproteinase-3 (TIMP-3), a recently cloned member of TIMP gene family, has been implicated in the negative regulation of tumor cell invasion and tumor growth. Down-regulation of this gene has been shown to occur in a mouse carcinogenesis model, suggesting that it might play a role in the tumor progression of some cancers. In this study, we used human gastric cancer cell lines to investigate whether TIMP-3 gene expression is suppressed in human gastric cancer. We examined whether aberrant DNA methylation of the 5'-CpG island of the TIMP-3 gene is involved in this cancer. Nine of 10 human gastric cancer cell lines completely lost TIMP-3 gene expression compared with normal samples. Southern blot analysis and bisulfite genomic sequencing revealed aberrant hypermethylation near the transcription-start site of the TIMP-3 gene in all cell lines lacking TIMP-3 expression. Treatment of these cell lines with the demethylating agent 5-aza-2'-deoxycytidine restored TIMP-3 gene expression. Our results suggest that the TIMP-3 gene is another early target of tumor-associated aberrant DNA methylation in human gastric carcinogenesis. Consequently, genetic silencing of TIMP-3 may lead to a more malignant and invasive phenotype in these cancer cells.

Plasma membrane mediated action of progesterone in amphibian (Rana dybowskii) oocyte maturation.

The mechanism of progesterone action within the ovarian follicle was investigated in Rana dybowskii, by using immobilized progesterone. Fluorescein isothiocyanate-labeled progesterone 3-O-carboxymethyloxime-BSA (P-BSA) was localized on the outside surface of the denuded oocyte, which indicated that P-BSA did not cross the barrier of cell surface. Progesterone-BSA induced germinal vesicle breakdown (GVBD) of denuded oocytes in a dose-dependent manner but failed to induce GVBD of follicle wall-enclosed oocytes. The time course of P-BSA-induced GVBD in denuded oocytes was similar to that observed with progesterone. Furthermore, both P-BSA and progesterone induced oocyte maturation in the presence of RU486, a well-known nuclear progesterone receptor antagonist. Treatment of denuded oocytes with P-BSA resulted in a threefold increase in inositol triphosphate (IP3) and a fourfold increase in diacylglycerol levels within 10 min. Additionally protein kinase C (PKC) activity was markedly increased by 30 min of incubation following exposure to P-BSA. Such changes were not observed in denuded oocytes exposed to beta-estradiol-6-O-carboxymethyloxime-BSA, which failed to induce GVBD. These results suggest that progesterone acts initially at the oocyte surface where it triggers generation of membrane-mediated second messengers during oocyte maturation in amphibians.

Seasonal fluctuations in pituitary gland and plasma levels of gonadotropic hormones in Rana.

Changes in plasma and pituitary levels of two gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), in male and female Korean frogs (Rana dybowskii and Rana nigromaculata) were examined. Plasma levels of LH and FSH were measured by radioimmunoassay using antibodies raised against bullfrog LH and FSH. In male and female R. dybowskii, plasma concentrations of LH were low in early hibernation (October-January) and increased to high levels by late hibernation, when breeding occurs (late February-early March). Plasma FSH levels were also higher in the breeding period than during hibernation in male and female animals, but absolute levels of FSH were much lower than those of LH. In females, pituitary LH levels were higher in early hibernation, whereas pituitary FSH in females and pituitary LH and FSH in males changed little during hibernation. Plasma LH levels of frogs having uterine eggs or in amplexus were much higher (> 25 ng/ml) than those of frogs with unovulated follicles (December) (< 8 ng/ml) or frogs that had already spawned (< 11 ng/ml). In R. nigromaculata, plasma LH and FSH levels of females collected during hibernation (October-May) were relatively low; however, following hibernation, plasma LH and FSH levels were markedly elevated for a short period. Thus, these animals exhibit a clear gonadotropin surge prior to ovulation and spawning. Soon after spawning, however, gonadotropin levels dropped to basal levels. Following spawning in females, levels of FSH increased steadily and rapid follicle growth occurred until August. By September, FSH had dropped to basal levels. In males, a sharp elevation of LH and FSH levels occurred during the short breeding period followed by a second increase in August, when early stages of spermatogenesis were evident.