In Vitro Analysis of the Efficacy of Endovascular Thrombectomy Techniques according to the Vascular Tortuosity Using 3D Printed Models

BACKGROUND AND PURPOSE

Achieving complete recanalization with the front-line endovascular thrombectomy device improves the outcome of acute stroke. The aim of this study was to evaluate whether various thrombectomy techniques including contact aspiration, stent retriever thrombectomy, and combination therapy differ in first-pass effect and distal emboli in acute large-vessel occlusion simulated using 3D printed nontortuous and tortuous cerebrovascular anatomy models.

MATERIALS AND METHODS

3D printed flow models were manufactured using angiographic data of nontortuous and acutely angulated tortuous vascular anatomy from real patients. Three thrombectomy techniques, contact aspiration, stent retriever, and combined methods, were tested under proximal protection with the balloon-guiding catheter. The first-pass effect and distal emboli rates were analyzed in addition to the thrombectomy-failure mechanisms of the respective techniques.

RESULTS

A total of 30 thrombectomy experiments were performed. The overall incidence of first-pass effect in the nontortuous and tortuous anatomy was 80.0% versus 46.7%. The overall incidence of distal emboli in the nontortuous and tortuous anatomy was 26.7% versus 46.7%. The contact aspiration technique showed better first-pass effect (80.0%) and distal emboli rates (20%) in the tortuous model compared with other techniques. The combined technique did not show remarkable superiority of the first-pass effect and distal emboli in either the nontortuous or tortuous anatomy. Shearing off of the thrombus was the main mechanism of thrombectomy failure in the combined group.

CONCLUSIONS

The tortuous vascular anatomy may worsen the first-pass effect and distal emboli rates. The combined techniques failed to show improvement in outcome due to the shearing-off phenomenon of the thrombus during retrieval.

Clot Meniscus Sign: An Angiographic Clue for Choosing between Stent Retriever and Contact Aspiration in Acute Basilar Artery Occlusion

BACKGROUND AND PURPOSE

The efficacy of mechanical thrombectomy methods may differ depending on the characteristics of the occlusion. The purpose of this study was to compare the recanalization efficacy and treatment outcome of a stent retriever versus contact aspiration in patients with acute basilar artery occlusion according to the angiographic characteristics of the occlusion.

MATERIALS AND METHODS

One hundred sixty-one patients with acute basilar artery occlusion who underwent mechanical thrombectomy were retrospectively analyzed. A stent retriever was compared with contact aspiration thrombectomy according to the clot meniscus sign, defined as a meniscoid/tram-track-like sidewall contrast opacification of the thrombus. A propensity score matching analysis was performed. Clinical/angiographic characteristics and treatment and clinical outcomes were compared.

RESULTS

Overall, a stent retriever (n = 118) and contact aspiration (n = 43) did not show significant differences in the successful recanalization (82.2% versus 86.0%) and good clinical outcome rates (32.2% versus 39.5%). In patients with the positive meniscus sign, contact aspiration was associated with shorter procedural time (44 versus 26 minutes, P = .018), a lower number of passes (2 versus 1, P = .041), a higher complete recanalization rate (58.8% versus 85.7%, P = .021), and a higher rate of first-pass effect (27.9% versus 53.6%, P = .031) compared with a stent retriever. After propensity score matching, contact aspiration was associated with higher complete recanalization rates (59.3% versus 85.7%, P = .033). No significant differences in the outcomes were noted between a stent retriever and contact aspiration in patients negative for the meniscus sign.

CONCLUSIONS

The efficacy of the mechanical thrombectomy techniques may differ according to the angiographic characteristics of occlusion in patients with basilar artery occlusion. Contact aspiration may be more effective in terms of recanalization compared with a stent retriever in patients with the clot meniscus sign.

Hyperattenuating lesions after mechanical thrombectomy in acute ischaemic stroke: factors predicting symptomatic haemorrhage and clinical outcomes

AIM

To evaluate the clinical significance of hyperattenuating lesions on CT after mechanical thrombectomy for acute ischaemic stroke, and to identify imaging factors that predict symptomatic haemorrhage and unfavourable outcomes.

MATERIALS AND METHODS

Seventy-eight patients with acute ischaemic stroke in the anterior circulation who underwent mechanical thrombectomy were evaluated. All patients underwent post-interventional unenhanced computed tomography (CT) within 24 h and follow-up CT or magnetic resonance imaging (MRI) within 7 days. Baseline characteristics and clinical outcomes were compared between patients with and without hyperattenuating lesions. In patients with hyperattenuating lesions, clinical and imaging factors that predict symptomatic haemorrhage and unfavourable outcomes were determined.

RESULTS

Fifty-six of 78 patients (71.8%) demonstrated hyperattenuating lesions on post-interventional CT. Patients with hyperattenuating lesions showed lower Alberta Stroke Program Early CT score (ASPECTS), persistent/symptomatic haemorrhage, and unfavourable outcomes than those without. In patients with hyperattenuating lesions, larger hyperattenuating lesion volume (>21.3 ml; OR, 55.60, p<0.001) and perilesional oedema (OR, 46.04, p=0.015) were independent factors predicting symptomatic haemorrhage. Older age (OR, 1.2, p=0.006) and lower ASPECTS (OR, 0.45, p=0.046) were independent factors predicting unfavourable outcomes in patients with hyperattenuating lesions. Adding the volume of the hyperattenuating lesion to age and ASPECTS increased the predictive performance of unfavourable outcomes (area under the curve 0.874 versus 0.934, p=0.043).

CONCLUSIONS

Hyperattenuating lesions on post-interventional CT are associated with increased risk of symptomatic haemorrhage and unfavourable outcomes. Larger hyperattenuating lesion volume is an independent factor of symptomatic haemorrhage and it has added predictive value for unfavourable outcomes.

Efficacy and Safety of Flow-Diverter Therapy for Recurrent Aneurysms after Stent-Assisted Coiling

BACKGROUND AND PURPOSE

Flow-diverter treatment for previously stented aneurysms has been reported to be less effective and prone to complications. In this study, we evaluated the effectiveness and safety of flow diverters for recurrent aneurysms after stent-assisted coiling.

MATERIALS AND METHODS

Patients who underwent flow-diverter placement for recurrent aneurysms after stent-assisted coiling between March 2015 and March 2019 were recruited. Clinical and radiographic characteristics and clinical and angiographic outcomes were retrospectively evaluated.

RESULTS

Among 133 patients who underwent flow-diverter insertion, 17 (male/female ratio = 5:12; mean age, 53.8 years) were treated for recurrent aneurysms after stent placement with (n = 16) or without (n = 1) coiling. Eight patients initially presented with subarachnoid hemorrhage; 7, with headache; and 2, with visual field defects. Angiographic morphology included large/giant saccular in 12 patients, dissecting in 2, fusiform in 1, traumatic pseudoaneurysm in 1, and ruptured blood blister-like aneurysm in 1. The duration between the first treatment and flow-diverter placement ranged from 2 weeks to 15 months (median, 6 months). Flow-diverter placement was successful in all cases without any complications. All patients had favorable outcomes (mRS, 0-2), without any newly appearing symptoms. Aneurysms were followed up with conventional angiography at least once in 6-18 months. Sixteen aneurysms showed complete occlusion, and 1 aneurysm was enlarged.

CONCLUSIONS

Results from this case series investigating flow-diverter placement for recurrent aneurysms after stent-assisted coiling suggested that the procedure is safe and effective. Further study in a larger population may be warranted.

Impact of Balloon-Guiding Catheter Location on Recanalization in Patients with Acute Stroke Treated by Mechanical Thrombectomy

BACKGROUND AND PURPOSE

Mechanical thrombectomy with proximal flow control and forced aspiration may improve the outcome of endovascular revascularization therapy for patients with acute stroke. The purpose of this study was to compare the impact of balloon-guiding catheter locations in patients treated for anterior circulation acute ischemic stroke using mechanical thrombectomy.

MATERIALS AND METHODS

The influence of the balloon-guiding catheter location (proximal, balloon-guiding catheter tip proximal to C1 vertebral body; distal, between the skull base and the C1 vertebral body) was analyzed in patients with acute anterior circulation stroke treated with stent-retriever thrombectomy. The baseline angiographic/clinical characteristics, time intervals, recanalization rates, and clinical outcomes were compared.

RESULTS

The clinical analysis included 102 patients (mean age, 69.5 ± 12.8 years; male/female ratio = 52:50). The balloon-guiding catheter was located distally in 49 patients and proximally in 53 patients for flow control and forced aspiration during stent retrieval. The puncture-to-recanalization time was shorter in the distal group than in the proximal group (40 versus 56 minutes, P = .02). Successful and complete recanalizations were more frequently achieved in the distal group compared with the proximal group (98.0% versus 75.5%. P = .003; 67.3% versus 45.3%, P = .04, respectively). Multivariate analysis showed that the distal catheterization location was independently associated with successful recanalization (adjusted OR, 13.4; 95% CI, 2.4-254.8; P = .02).

CONCLUSIONS

Location of the balloon-guiding catheter has a significant impact on recanalization in patients with acute stroke. The balloon-guiding catheter should be positioned as distally as safely possible in the cervical ICA for maximally effective thrombectomy.

Abstract WP4: Which Characteristics Determine the Decision to Proceed With Endovascular Therapy in Acute Stroke Patients: Results From an International Multidisciplinary Study

Introduction: The current management of acute ischemic stroke has changed recently with the publication of randomized trials using endovascular therapy (EVT).

Rationale/Hypothesis: Limited information is however available on how physicians make decisions regarding patient selection for endovascular therapy (EVT) in the real-world.

Methods: We conducted an international web-based cross-sectional survey of stroke physicians and interventionalists to assess the decision to offer EVT. Part 1 of the survey used hierarchical Bayes’ disaggregate discrete choice modelling to analyze ten pairs of patient scenarios, randomly generated from ten key patient characteristics to have respondents choose which scenario was best suited for EVT in their practice. Part 2 of the survey used mixed effects logistic regression modelling to analyze 22 randomly chosen patient scenarios, again randomly generated from several key patient and hospital level characteristics.

Results: 607 physicians [mean age of 44 (SD 8.5) years, 83.5% men, 53.6% neurologists, 28.7% neuro-interventionists, 13.3% neurosurgeons, 4.7% other], from 38 countries participated. Using disaggregate discrete choice analysis, the most influential characteristic in deciding about EVT was the extent of ischemic change (ASPECTS)/volume of infarct core (26-28% of the choice). Patient age, premorbid status, baseline NIHSS score, and occlusion location (13-15% each) were the other relevant characteristics. Using mixed effects logistic regression, baseline stroke severity (NIHSS> 15 vs. NIHSS 0-5, OR 6.7; 95% CI 4.8-9.5), ASPECTS (5-7 vs. 0-4, OR 9.4; 95% CI7.4-11.9) and occlusion location (distal M2 vs. ICA/M1, OR 012; 95% CI 0.08-0.17) were the most relevant characteristics in deciding about EVT. Time from stroke onset, sex, comorbidities, time of day (off hours vs. day time) were all less relevant in deciding about EVT in both analyses.

Conclusion: Severity of stroke assessed clinically, and extent of brain infarction and location of thrombus assessed on imaging are the dominant characteristics that treating physicians use in the real world when deciding about EVT for patients with an acute ischemic stroke.

Path analysis of prenatal mercury levels and birth weights in Korean and Taiwanese birth cohorts

Prospective cohort studies of the effect of mercury (Hg) exposure on birth weight have shown conflicting results. We combined data from Taiwanese and Korean birth cohorts, and assessed the effects of Hg exposure on birth weight. The first cohort was drawn from the Mothers and Children's Environmental Health (MOCEH) study performed in Korea from 2006 to 2010. The second cohort was enrolled from 2004 to 2005 and included singleton term births from the Taiwan Birth Panel Study (TBPS). In total, 1147 pregnant women were included in this study. A pooled analysis was performed to obtain combined estimates of the association between prenatal total Hg exposure and birth weight. A significant negative association between maternal and cord blood Hg and birth weight in the high-Hg group (Hg level>25th percentile) was detected (maternal blood: β=-0.056; 95% CI, -0.100 to -0.013, cord blood: β=-0.075; 95% CI, -0.121 to -0.028). Hg level showed a negative coefficient in the path analysis, indicating an adverse effect on birth weight (total effects: β=-0.177, P=0.01 in MOCEH, β=-0.204, P=0.03 in TBPS), but fish consumption exhibited a strong positive coefficient. In addition, fish consumption exerted a significant indirect effect on birth weight through exposure to cord blood Hg. Exposure to hazardous contaminants and beneficial nutrients may be highly correlated in those who frequently consume fish. Moreover, Hg in cord blood may adversely affect birth weight.

Prevalence of Intracranial Aneurysms in Patients with Aortic Dissection

BACKGROUND AND PURPOSE

There is an uncertainty about the association between intracranial aneurysms and aortic dissection. We aimed to determine the prevalence of intracranial aneurysms in patients with aortic dissection and evaluate the independent risk factors for the presence of intracranial aneurysms in these patients.

MATERIALS AND METHODS

Seventy-one patients with a confirmed aortic dissection who underwent additional brain imaging were enrolled as the aortic dissection group, and 2118 healthy individuals with brain imaging, as controls. Demographic data were obtained from their medical records, including age, sex, comorbidities, and arch vessel involvement of aortic dissection. Two readers reviewed all brain images independently regarding the presence, morphology, size, and location of intracranial aneurysms. Baseline characteristics were compared between the aortic dissection group and controls by propensity score matching, and logistic regression analysis was performed for independent risk factors for the presence of intracranial aneurysms.

RESULTS

The prevalence of intracranial aneurysms was 12.96% in the aortic dissection group and 1.85% in controls (P = .022). The mean diameter of intracranial aneurysms was significantly larger in the aortic dissection group (5.79 ± 3.26 mm in aortic dissection versus 3.04 ± 1.57 mm in controls; P = .008), and intracranial aneurysms of >7 mm were also more common in the aortic dissection group (28.6% in aortic dissection versus 5.3% in controls, P = .003). On multivariate analysis, arch vessel involvement of aortic dissection was an independent risk factor for the presence of intracranial aneurysms (odds ratio, 6.246; 95% confidence interval, 1.472-26.50; P = .013).

CONCLUSIONS

Patients with aortic dissection have a high prevalence of intracranial aneurysms, and selective screening for brain vessels could be considered in these patients with arch vessel involvement. A further prospective study is needed to demonstrate a substantial prevalence of intracranial aneurysms.

Prenatal exposure to perfluorinated compounds affects thyroid hormone levels in newborn girls

Perfluorinated compounds (PFCs) are ubiquitous in the environment and have been detected in humans and wildlife. Exposure to PFCs has decreased in the United States recently, while exposure to PFCs continues in Asian countries, which represents a public health concern. Various mechanisms by which PFCs affect fetal growth have been proposed, such as activation of peroxisome proliferators, disruption of thyroid hormones and changes in lipid metabolism. However, the overall evidence for an association with thyroid hormones is not strong. Therefore, we examined the effect of various prenatal PFCs on cord blood thyroid hormones: triiodothyronine (T3), thyroxine (T4), thyroid stimulating hormone (TSH) levels, and explored the endocrine disrupting effect of these PFCs on thyroid hormone levels in children according to gender. Two hundred and seventy-nine study participants were selected from among the enrolled participants in the Ewha Birth & Growth Retrospective Cohort, a retrospective birth cohort study conducted at Ewha Womans University Hospital, Seoul, Korea between 2006 and 2010. A generalized linear model was constructed to explore the association of PFCs and thyroid hormones. Further, an analysis stratified by gender was conducted. Our study shows that cord blood perfluoro n-pentanoic acid (PFPeA) was positively associated with cord blood T4 (p=0.01) level. Gender-specific analysis showed that prenatal PFCs: PFPeA and Perfluorohexane sulfonic acid (PFHxS) exposure significantly increased T4 (p<0.01) and T3 (p=0.03), respectively, while perfluorononanoic acid (PFNA) decreased TSH (p=0.04) concentration in newborn girls. Thus, prenatal PFC exposure may disrupt thyroid hormone homeostasis. Thyroid hormones play a crucial role in fetal development and may have gender specific action. Hence, these results are of utmost importance in high-risk groups, such as pregnant women and children.

Long working hours and overweight and obesity in working adults

Background

Previous studies have identified a link between gender and the various risk factors associated with obesity. We examined obesity risk factors in working adults to identify the effects of differences in body mass index (BMI) and percentage body fat (PBF) between women and men.

Methods

A total of 1,120 adults agreed to participate in the study. Data from 711 participants, including 411 women and 300 men, were analyzed. Multiple logistic regression analysis was used to estimate the effects of risk factors on obesity and being overweight. In addition, the least-squares (LS) means of both BMI and PBF were estimated by analysis of covariance (ANCOVA) in a generalized linear model. 

Results

Increases in BMI and PBF were significantly related to an age > 50 years and long working hours in women after compensating for confounding factors. Using the PBF criterion, the odds ratio (OR) of being overweight or obese in women > 50 years of age who worked for > 9 h a day was 3.9 (95% confidence interval [CI], 1.05–11.00). For BMI, women who were > 50 years of age and worked for > 9 h a day were 3.82 times (95% CI, 1.31–11.14) more likely to be overweight or obese than those who were < 50 years of age and worked for < 9 h a day.

Conclusion

Obesity in working adults was associated with > 50 years of age and long working hours in women. Further studies are needed to investigate the underlying mechanisms of this relationship and its potential implications for the prevention and management of excess weight and obesity.

Neurodevelopment in Early Childhood Affected by Prenatal Lead Exposure and Iron Intake

No safe threshold level of lead exposure in children has been recognized. Also, the information on shielding effect of maternal dietary iron intake during pregnancy on the adverse effects of prenatal lead exposure on children's postnatal neurocognitive development is very limited. We examined the association of prenatal lead exposure and neurodevelopment in children at 6, 12, 24, and 36 months and the protective action of maternal dietary iron intake against the impact of lead exposure. The study participants comprise 965 pregnant women and their subsequent offspring of the total participants enrolled in the Mothers and Children's environmental health study: a prospective birth cohort study. Generalized linear model and linear mixed model analysis were performed to analyze the effect of prenatal lead exposure and mother's dietary iron intake on children's cognitive development at 6, 12, 24, and 36 months. Maternal late pregnancy lead was marginally associated with deficits in mental development index (MDI) of children at 6 months. Mothers having less than 75th percentile of dietary iron intake during pregnancy showed significant increase in the harmful effect of late pregnancy lead exposure on MDI at 6 months. Linear mixed model analyses showed the significant detrimental effect of prenatal lead exposure in late pregnancy on cognitive development up to 36 months in children of mothers having less dietary iron intake during pregnancy. Thus, our findings imply importance to reduce prenatal lead exposure and have adequate iron intake for better neurodevelopment in children.

Combination of Multicatheter Plus Stent or Balloon for Treatment of Complex Aneurysms

BACKGROUND AND PURPOSE

Coiling of complex aneurysms is still difficult even with current adjuvant techniques. This study sought to evaluate the safety and effectiveness of a combination of multicatheter plus stent or balloon for the treatment of complex aneurysms.

MATERIALS AND METHODS

All complex aneurysms that underwent coiling with the combination technique were identified from prospectively maintained neurointerventional data bases. "Complex aneurysm" was defined as a wide-neck aneurysm with branch incorporation into or a deep lobulation of the sac. The clinical and angiographic outcomes were retrospectively analyzed.

RESULTS

Sixty-two complex aneurysms (12 ruptured, 50 unruptured) in 62 patients (mean age, 57 years; male/female ratio, 12:50) were treated with a combination technique by using a multicatheter plus stent (n = 42, 3 ruptured) or balloon (n = 20, 9 ruptured). Treatment-related morbidity (grade 3 hemiparesis) occurred in 1 patient (1.6%). Except for 1 patient who had treatment-related morbidity, none of the other patients with unruptured aneurysms developed new neurologic symptoms at discharge. Nine of the 12 patients with ruptured aneurysms had good outcomes (Glasgow Outcome Score, 4 or 5) at the latest follow-up (mean, 32 months; range, 6-72 months), and 1 patient died from an initial SAH. Posttreatment control angiograms revealed complete occlusion in 27, neck remnant in 34, and incomplete occlusion in 1 aneurysm. At least 1 follow-up catheter or MR angiogram was available in 80.6% (n = 50) (mean, 21 months; range, 6-65 months). There were 4 minor and 3 major recurrences (14.0%).

CONCLUSIONS

In this case series, the combination technique by using multicatheter plus stent or balloon seemed safe and effective for the treatment of complex aneurysms.

Factors Related to Relapse After 6 Months of Smoking Cessation Among Men in the Republic of Korea: A Cross-Sectional Study

We identified factors associated with relapse after 6 months of smoking cessation (late relapse) among males of the Republic of Korea. Of the 222,707 smokers who visited public health center-based smoking cessation clinics (SCCs) between January 1, 2009 and mid-December 2009, we included 1720 individuals who successfully completed a 6-month smoking cessation program at an SCC. These participants were selected via a random stratified sampling design and completed an SCC user satisfaction survey between December 31, 2009 and January 6, 2010. Multiple logistic regression was used to identify factors associated with late relapse, and path analysis was employed to explore relationships among these factors. The frequency of late relapse was 21.6% (n = 372). Residence in a metropolitan area, low socioeconomic status, and the use of nicotine replacement therapy (NRT) were associated with statistically significant increases in late relapse, whereas greater access to counseling and more satisfaction with the SCC were associated with reduced late relapse. The path analysis showed that a greater number of cigarettes smoked daily and a younger age at smoking initiation exerted significant indirect effects on late relapse when NRT was employed. Residence in a metropolitan area indirectly prevented late relapse as counseling frequency increased. NRT use, counseling frequency, and SCC user satisfaction were affected by both smoking behavior and socioeconomic status. Relapse prevention efforts should concentrate on increasing both counseling frequency and SCC user satisfaction. Future studies should focus on the effect of NRT on the maintenance of long-term cessation at the population level in real-world settings.

Efficacy of skull plain films in follow-up evaluation of cerebral aneurysms treated with detachable coils: quantitative assessment of coil mass

BACKGROUND AND PURPOSE

Skull plain films of coiled aneurysms have been used in a limited role, including morphologic comparison of the coil mass. We aimed to evaluate the efficacy of skull plain films in patients treated with detachable coils by using quantitative assessment.

MATERIALS AND METHODS

In this retrospective study, 78 pairs of the initial and follow-up skull anteroposterior and lateral images were reviewed independently by 2 neuroradiologists. The largest diameter, the perpendicular diameter, and area of the coil mass were measured separately on plain film, and quantitative changes of parameters were compared between subgroups, which were determined by consensus, depending on the need for retreatment. Subgroup analysis was also performed according to aneurysm size, packing attenuation, and ruptured status.

RESULTS

On skull lateral images, mean quantitative changes of the largest diameter (0.53 ± 0.43 mm versus 1.17 ± 0.91 mm, P < .01), the perpendicular diameter (0.56 ± 0.48 mm versus 1.20 ± 1.05 mm, P < .01), and the area of the coil mass (5.21 ± 7.51 mm(2) versus 10.55 ± 10.93 mm(2), P < .02) differed significantly between subgroups. Receiver operating characteristic analysis showed quantitative change of the largest diameter (>1.1 mm; sensitivity, 50.0%; specificity, 90.3%), the perpendicular diameter (>.9 mm; sensitivity, 62.5%; specificity, 85.5%), and the area (>8.5 mm(2); sensitivity, 50.0%; specificity, 83.9%) on skull lateral films to be indicative of aneurysm recurrence, and the diagnostic accuracy of these parameters increased significantly in the high-packing-attenuation group.

CONCLUSIONS

Quantitative measurement of the coil mass by using skull plain lateral images has the potential to predict aneurysm recurrence in follow-up evaluations of intracranial aneurysms with coiling.

The Possibility of TBC1D21 as a Candidate Gene for Teat Numbers in Pigs

Based on a quantitative traits locus (QTL) study using a F₂ intercross between Landrace and Korean native pigs, a significant QTL affecting teat numbers in SSC7 was identified. The strong positional candidate gene, TBC1D21, was selected due to its biological function for epithelial mesenchymal cell development. Sequence analysis revealed six single nucleotide polymorphisms (SNPs) in the TBC1D21 gene. Among these, two SNP markers, one silent mutation (SNP01) for g.13,050A>G and one missense mutation (SNP04) for c.829A>T (S277C), were genotyped and they showed significant associations with teat number traits (p value = 6.38E-05 for SNP01 and p value = 1.06E-07 for SNP04 with total teat numbers). Further functional validation of these SNPs could give valuable information for understanding the teat number variation in pigs.

Effect of hemoglobin adjustment on the precision of mercury concentrations in maternal and cord blood

The cord-blood mercury concentration is usually considered the best biomarker in regard to developmental methylmercury neurotoxicity. However, the mercury concentration may be affected by the binding of methylmercury to hemoglobin and perhaps also selenium. As cord-blood mercury analyses appear to be less precise than suggested by laboratory quality data, we studied the interrelationships of mercury concentrations with hemoglobin in paired maternal and cord blood samples from a Faroese birth cohort (N=514) and the Mothers and Children's Environmental Health study in Korea (n=797). Linear regression and structural equation model (SEM) analyses were used to ascertain interrelationships between the exposure biomarkers and the possible impact of hemoglobin as well as selenium. Both methods showed a significant dependence of the cord-blood concentration on hemoglobin, also after adjustment for other exposure biomarkers. In the SEM, the cord blood measurement was a less imprecise indicator of the latent methylmercury exposure variable than other exposure biomarkers available, and the maternal hair concentration had the largest imprecision. Adjustment of mercury concentrations both in maternal and cord blood for hemoglobin improved their precision, while no significant effect of the selenium concentration in maternal blood was found. Adjustment of blood-mercury concentrations for hemoglobin is therefore recommended.

Treatment of multiple intracranial aneurysms with 1-stage coiling

BACKGROUND AND PURPOSE

Although multiple intracranial aneurysms are frequent, determining treatment strategy and methods for them is often complicated. The aim of this study was to evaluate the safety and effectiveness of 1-stage coiling for multiple intracranial aneurysms.

MATERIALS AND METHODS

All patients who underwent 1-stage coiling for ≥2 aneurysms were identified from a prospectively registered neurointerventional data base during 10 years. The patient characteristics and clinical and angiographic outcomes at discharge and follow-up were retrospectively evaluated.

RESULTS

One hundred sixty-seven patients (male/female ratio, 30:137; mean age, 58 years) with multiple aneurysms (418 aneurysms; mean, 2.5 aneurysms/patient) underwent attempted 1-stage coiling for ≥2 aneurysms (359 aneurysms; mean, 2.1 aneurysms/patient). In 131 patients (78.4%), all detected aneurysms were treated with coiling only. Treatment-related morbidity and mortality at discharge were 1.8% and 0.6% per patient, respectively. Of the 132 patients without subarachnoid hemorrhage, 129 (97.7%) had favorable outcomes (mRS 0-2) at discharge; of the 35 patients with SAH, 27 (77.1%) had favorable outcomes at discharge. Of the 162 patients (97%) for whom clinical follow-up was available (mean, 35.8 months), 154 patients (95.1%) had favorable outcomes. Immediate posttreatment angiography showed complete occlusion in 186 (51.8%) aneurysms, neck remnants in 134 (37.3%), sac remnants in 33 (9.2%), and failure in 6 (1.7%). Of the 262 (73.9%) aneurysms that underwent follow-up imaging (mean, 24.8 months), 244 (93.1%) showed a stable or improved state, with 12 (4.6%) minor and 6 (2.3%) major recurrences.

CONCLUSIONS

One-stage coiling of multiple aneurysms seems to be safe and effective, with low morbidity and mortality.

Death-associated protein kinase 1 has a critical role in aberrant tau protein regulation and function

The presence of tangles composed of phosphorylated tau is one of the neuropathological hallmarks of Alzheimer's disease (AD). Tau, a microtubule (MT)-associated protein, accumulates in AD potentially as a result of posttranslational modifications, such as hyperphosphorylation and conformational changes. However, it has not been fully understood how tau accumulation and phosphorylation are deregulated. In the present study, we identified a novel role of death-associated protein kinase 1 (DAPK1) in the regulation of the tau protein. We found that hippocampal DAPK1 expression is markedly increased in the brains of AD patients compared with age-matched normal subjects. DAPK1 overexpression increased tau protein stability and phosphorylation at multiple AD-related sites. In contrast, inhibition of DAPK1 by overexpression of a DAPK1 kinase-deficient mutant or by genetic knockout significantly decreased tau protein stability and abolished its phosphorylation in cell cultures and in mice. Mechanistically, DAPK1-enhanced tau protein stability was mediated by Ser71 phosphorylation of Pin1, a prolyl isomerase known to regulate tau protein stability, phosphorylation, and tau-related pathologies. In addition, inhibition of DAPK1 kinase activity significantly increased the assembly of MTs and accelerated nerve growth factor-mediated neurite outgrowth. Given that DAPK1 has been genetically linked to late onset AD, these results suggest that DAPK1 is a novel regulator of tau protein abundance, and that DAPK1 upregulation might contribute to tau-related pathologies in AD. Therefore, we offer that DAPK1 might be a novel therapeutic target for treating human AD and other tau-related pathologies.

Prenatal exposure to PM₁₀ and NO₂ and children's neurodevelopment from birth to 24 months of age: mothers and Children's Environmental Health (MOCEH) study

INTRODUCTION

Previous studies have suggested adverse effects of maternal exposure to air pollution on neurodevelopment in early childhood.

OBJECTIVES

We aimed to investigate the association between prenatal exposure to particulates of less than 10 μm in diameter (PM10) and nitrogen dioxide (NO2) and neurodevelopment in children during the first 24 months of their lives.

METHODS

The MOCEH study is a prospective birth cohort study in South Korea. Average exposure levels to PM10 and NO2 during the entire pregnancy were estimated using the inverse distance weighting (IDW) method. A total of 520 mother-child pairs who completed neurodevelopmental assessments using the Korean Bayley Scale of Infant Development II (K-BSID-II) more than once at ages of 6, 12 and 24 months were included. Mental developmental index (MDI) and psychomotor developmental index (PDI) from the K-BSID-II were used as outcome variables.

RESULTS

There were negative associations between maternal exposure to PM10 and MDI (β=-2.83; p=0.003) and PDI (β=-3.00; p=0.002) throughout the first 24 months of life as determined by the generalized estimating equation (GEE) model. Maternal NO2 exposure was related with impairment of psychomotor development (β=-1.30; p=0.05) but not with cognitive function (β=-0.84; p=0.20). In a multiple linear regression model, there were significant effects of prenatal air pollution exposure on MDI (PM10: β=-4.60; p<0.001, NO2: β=-3.12; p<0.001) and PDI (PM10: β=-7.24; p<0.001, NO2: β=-3.01; p<0.001) at 6 months, but no significant association was found at 12 and 24 months of age.

CONCLUSIONS

The findings suggest that exposure to air pollution may result in delayed neurodevelopment in early childhood.

Genome-wide association study identifies quantitative trait loci affecting hematological traits in an F2 intercross between Landrace and Korean native pigs

Changes affecting the status of health and robustness can bring about physiological alterations including hematological parameters in swine. To identify quantitative trait loci (QTL) associated with eight hematological traits (one leukocyte trait, six erythrocyte traits and one platelet trait), we conducted a genome-wide association study using the PorcineSNP60K BeadChip in a resource population derived from an intercross between Landrace and Korean native pigs. A total of 36 740 SNPs from 816 F2 progeny were analyzed for each blood-related trait after filtering for quality control. Data were analyzed by the genome-wide rapid association using mixed model and regression (GRAMMAR) approach. A total of 257 significant SNPs (P < 1.36 × 10(-6) ) on SSC3, 6, 8, 13 and 17 were identified for blood-related traits in this study. Interestingly, the genomic region between 17.9 and 130 Mb on SSC8 was found to be significantly associated with red blood cell, mean corpuscular volume and mean corpuscular hemoglobin. Our results include the identification of five significant SNPs within five candidate genes (KIT, IL15, TXK, ARAP2 and ERG) for hematopoiesis. Further validation of these identified SNPs could give valuable information for understanding the variation of hematological traits in pigs.

Comparison of stent retriever and intra-arterial fibrinolysis in patients with acute ischaemic stroke

BACKGROUND AND PURPOSE

Although the stent retriever (SR) has shown a better reperfusion rate and clinical outcome than the older generation mechanical clot retrieval device, it is uncertain whether the SR is superior to intra-arterial fibrinolysis (IAF).

METHODS

Ischaemic stroke patients who were treated with SR or IAF as initial endovascular treatment modality for unilateral arterial occlusion in the anterior circulation were included. Successful reperfusion was defined as Thrombolysis in Cerebral Infarction grade ≥2b. A favourable clinical outcome was defined as a modified Rankin Score ≤2 at 3 months.

RESULTS

Between January 2009 and May 2012, 55 patients were treated with SR and 50 patients were treated with IAF. The baseline characteristics were similar between the two groups except for the occlusion site and rescue treatment. In binary logistic regression analysis adjusted for the occlusion site and rescue treatment, SR was independently associated with increased successful reperfusion [82.0% vs. 47.3%; odds ratio (OR) 5.21; 95% confidence interval (CI) 1.92-14.14) and a more favourable clinical outcome at 3 months (54.0% vs. 43.6%; OR 3.40; 95% CI 1.31-8.84). The frequency of symptomatic intracranial haemorrhage and mortality at 3 months was not different between the two groups.

CONCLUSIONS

Stent retriever was as safe as and more effective than IAF. Our findings suggest that SR may be considered as an initial modality rather than IAF in acute stroke patients who undergo endovascular treatment.

Highly efficient secretion of heterologous proteins from Saccharomyces cerevisiae using inulinase signal peptides

The INU genes of Kluyveromyces marxianus encode inulinases which are readily secreted from Saccharomyces cerevisiae into the culture medium. To evaluate the utility of the INU signal peptides for the secretion of heterologous proteins from S. cerevisiae, a variety of expression and secretion vectors were constructed with GAL10 promoter and GAL7 terminator. The coding sequence for human lipocortin-1 (LC1) was inserted in-frame with the INU signal sequences, and then the secretion efficiency and localization of LC1 were investigated in more detail and compared with those when being expressed by the vector with the MFalpha1 leader peptide. The vector systems with INU signal peptides secreted ca. 95% of the total LC1 expressed into the extracellular medium, while the MFalpha1 leader peptide-containing vector resulted in very low secretion efficiency below 10%. In addition, recombinant human interleukin-2 (IL-2) was expressed and secreted with the vector systems with INU signal peptide, and a majority fraction of the human IL-2 expressed was found to be secreted into the extracellular medium as observed in LC1 expression. (c) 1995 John Wiley & Sons, Inc.

Clinical and angiographic characteristics of multiple dural arteriovenous shunts

BACKGROUND AND PURPOSE

The pathogenesis and characteristics of multiple DAVSs are not well-known. The purpose of this study was to evaluate the angiographic and clinical characteristics of patients with multiple DAVSs with an emphasis on the pathomechanism.

MATERIALS AND METHODS

One hundred seventy-nine patients with DAVS were reviewed. Patients with ≥ 2 fistulas at anatomically separate sites were included. Multiple DAVSs were categorized into synchronous (simultaneous multiplicity) or metachronous (temporal sequential development of multiplicity) types. The angiographic and clinical characteristics of these lesions were analyzed.

RESULTS

Fourteen patients were diagnosed with multiple DAVSs (7.8%; synchronous, n = 7; metachronous, n = 7). Thirteen of the 14 patients showed CVR (93%, Borden type II/III). Multiple DAVSs were frequently associated with dural sinus thrombosis (71.4%, n = 10). Synchronous DAVSs developed in association with an occluded sinus (n = 5). De novo metachronous lesions developed in association with thrombosis of a previously patent dural sinus (n = 3) or reopening of an occluded sinus (n = 2). Multiplicity was associated with aggressive initial symptoms in 64.3% (n = 9). The newly developed lesions in the metachronous types were accompanied by hemorrhage (n = 1), neurologic deficit (n = 1), worsening of the initial benign symptoms (n = 2), and incidental detection (n = 3). The mean time interval between the initial diagnosis and de novo lesion detection was 31.3 ± 29.8 months (range, 12-92 months).

CONCLUSIONS

Multiplicity of DAVSs is associated with poor angiographic and clinical prognosis, requiring an aggressive treatment and management strategy. Sinus thrombosis has a prominent role in the pathomechanism of DAVSs.

Reconstructive endovascular treatment of fusiform or ultrawide-neck circumferential aneurysms with multiple overlapping enterprise stents and coiling

BACKGROUND AND PURPOSE

Fusiform aneurysms and ultrawide-neck circumferential aneurysms are still some of the most challenging lesions. The aim of this study was to investigate the efficacy and feasibility of the use of multiple overlapping Enterprise stents with coiling for the treatment of fusiform or ultrawide-neck circumferential aneurysms.

MATERIALS AND METHODS

Twelve consecutive patients (9 men and 3 women; mean age, 56 years) with fusiform (n = 5) or ultrawide-neck circumferential (n = 7) aneurysms were treated with 2-3 overlapping Enterprise stents and coiling. The feasibility of this procedure and the clinical and angiographic outcomes of this technique were retrospectively evaluated.

RESULTS

All patients were successfully treated by using this technique without any complications. Posttreatment angiographic results revealed grade 4 occlusion of the aneurysm in 6, grade 3 in 4, and grade 2 in 2 patients. Clinical follow-up was performed in all patients (mean, 16 months; range, 5-24 months). Nine patients had an mRS score of 0. Two had an mRS score of 1, one of whom had an initial mRS score of 2 due to the mass effect of a giant aneurysm; the other had a recurrent aneurysm presenting with SAH 5 years after clipping. Angiographic follow-up was performed in 10 patients at 6-20 months posttreatment. Nine had stable or improved occlusion, while 1 had a minor recurrence.

CONCLUSIONS

In this small series, multiple overlapping Enterprise stents with coiling were a feasible and effective option for the treatment of fusiform and ultrawide-neck circumferential aneurysms. Further experience and follow-up are required to document the long-term efficacy of this treatment.

Mercury levels in maternal and cord blood and attained weight through the 24 months of life

Birth weight is a strong determinant of attained weight at early ages. Until now, many studies have reported that low birth weight corresponds with high mercury levels. However, the relationship between mercury exposure and attained weight of infant has not been well studied. Therefore, the aim of the present study was to assess the degree of prenatal exposure to mercury by measuring the total mercury levels in maternal and cord blood, and examine the relationship between the mercury level during pregnancy and the attained weight of infant during the first 24 months of life. The prospective cohort study of Mothers and Children's Environmental Health (MOCEH) was built up in 2006, and 921 mother-infant pairs were recruited. Information on the socio-demographic characteristics, health behavior and environmental exposure were collected from an interview with trained nurses. After delivery, infants and mothers were followed up at 6, 12 and 24 months and the weights of the infants were measured. The mercury concentrations in the late maternal blood (β=-0.19. p=0.05) and cord blood (β=-0.36. p=0.01) were negatively associated with the infants' attained weight over the first 24 months of age. The infants' attained weight in the small for their gestational age (SGA) group was lower than the normal birth weight group at the highest quartile of the mercury level. Therefore, efforts should be made to reduce the mercury level in the maternal blood at late pregnancy and cord blood. Further research on the possible harmful effects of prenatal mercury exposure on postnatal growth is recommended.

Stenting from the vertebral artery to the posterior inferior cerebellar artery

BACKGROUND AND PURPOSE

There are only a few reports on the feasibility and safety of stents used in the PICA, and clinical and angiographic follow-up results have not been fully addressed. We report our experiences of treating PICA origin or vertebral artery-PICA lesions by using self-expanding stents as adjuvant or rescue therapy with angiographic and clinical follow-up results.

MATERIALS AND METHODS

Six patients were treated with self-expanding stent placements from the vertebral artery to the PICA. Two patients had a vertebral artery dissecting aneurysm involving the PICA origin, 3 had vertebral artery-PICA aneurysms, and 1 had segmental stenosis of the vertebral artery harboring the origin of the PICA. The safety, feasibility, and follow-up angiographic results were retrospectively evaluated.

RESULTS

All procedures were successfully performed without any procedure-related complications. None of the patients showed PICA territorial infarction on DWI posttreatment. All patients were neurologically intact during the clinical follow-up of 3-24 months following the procedure. Follow-up angiography was performed at between 6 and 12 months in 5 of the 6 patients and was scheduled for the sixth patient but was not performed. The PICA showed good patency without in-stent stenosis in all 5 patients.

CONCLUSIONS

In patients with lesions of the PICA origin or vertebral artery-PICA lesions, vertebral artery-to-PICA stent placement may be an option for preserving PICA patency in selected cases.

Management of anterior inferior cerebellar artery aneurysms: endovascular treatment and clinical outcome

BACKGROUND AND PURPOSE

AICA aneurysms are rare and a challenge to treat surgically. We present our experience of the angiographic results and the clinical outcomes for 9 AICA aneurysms treated by EVT.

MATERIALS AND METHODS

Between 1997 and 2009, EVT was attempted for 9 AICA aneurysms. Six patients presented with SAH, and 3 aneurysms were found incidentally. The location of the aneurysms was the proximal AICA in 7 and the distal AICA in 2. Five aneurysms originated from an AICA-PICA variant. Clinical outcomes and procedural complications were evaluated, and angiography was performed 6, 12, and 24 months after embolization to confirm recanalization of the coiled aneurysm.

RESULTS

EVT was technically successful in 7 patients (78%). Surgical trapping was performed in 1 patient after failure of EVT, and another aneurysm occluded spontaneously, along with the parent artery during EVT. In 7 patients, the AICAs had good patency on postoperative angiography. Stent-assisted coiling was performed in 3 patients. Follow-up angiographies were performed in 7 patients and showed no evidence of recanalization or progressive occlusion with further thrombosis except in 1 patient. There was no evidence of aneurysm rupture during the follow-up period, and 8 patients were able to perform all usual activities (mRS score, 0-1).

CONCLUSIONS

EVT may provide a feasible and safe option as an alternative, though a microsurgical option is initially considered for the management of AICA aneurysms. Further follow-up and more experience are also necessary.

Emergent self-expanding stent placement for acute intracranial or extracranial internal carotid artery dissection with significant hemodynamic insufficiency

BACKGROUND AND PURPOSE

ICAD with hemodynamic insufficiency may present with either fulminant infarct or with progressive neurologic deterioration. The purpose of this study was to evaluate the safety and efficacy of emergent self-expanding stent placement for acute intracranial or extracranial ICAD with significant hemodynamic insufficiency.

MATERIALS AND METHODS

Eight patients (7 men and 1 woman; age range, 20-55 years; NIHSS score, 5-21) underwent emergent self-expanding stent placement for treatment of significant hemodynamic insufficiency due to acute ICAD. The safety and efficacy of emergent self-expanding stent placement were retrospectively evaluated.

RESULTS

All patients presented with progressive (n = 6) or fluctuating (n = 2) neurologic deficits and revealed markedly decreased perfusion on CT or MR perfusion studies. Conventional angiography revealed acute occlusion (n = 2) or critical stenosis (n = 6) in intracranial (n = 3) or extracranial (n = 5) carotid arteries with a lack of sufficient collaterals. Stent placement was successful in all patients without any procedure-related complications. In all patients, hemodynamic insufficiency was corrected immediately after stent placement, and neurologic symptoms were completely resolved during several days. Mean improvement of the NIHSS score between baseline and discharge was 11.6 (range, 5-21). All patients remained neurologically intact (mRS, 0) during clinical follow-up for a mean of 21 months (range, 8-50 months). Angiographic follow-up was available for 6 patients at 3-12 months. None of the 6 patients revealed residual or in-stent restenosis.

CONCLUSIONS

Self-expanding stent placement is a safe and effective option for selected patients with significant hemodynamic insufficiency due to acute intracranial or extracranial ICAD.

Population-attributable risk of low birthweight related to PM10 pollution in seven Korean cities

To understand the preventable fraction of low birthweight (LBW) deliveries due to maternal exposure to air pollution during pregnancy in Korea, it is important to quantify the population-attributable risk (PAR). Thus, we investigated the association between maternal exposure to air pollution during pregnancy and LBW, and calculated the PAR for air pollution and LBW in seven Korean cities. We used birth records from the Korean National Birth Register for 2004. A geographic information system and kriging methods were used to construct exposure models. Associations between air pollution and LBW were evaluated using univariable and multivariable logistic regression, and the PAR for LBW due to air pollution was calculated. Of 177 660 full-term singleton births, 1.4% were LBW. When only spatial variation of air pollution was considered in each city, the adjusted odds ratios unit of particulate matter <10 microm in diameter (PM(10)) for LBW were 1.08 [95% confidence interval [CI] 0.99, 1.18] in Seoul, 1.24 [95% CI 1.02, 1.52] in Pusan, 1.19 [95% CI 1.04, 1.37] in Daegu, 1.12 [95% CI 0.98, 1.28] in Incheon, 1.22 [95% CI 0.98, 1.52] in Kwangju, 1.05 [95% CI 1.00, 1.11] in Daejeon and 1.19 [95% CI 1.03, 1.38] in Ulsan. The PARs for LBW attributable to maternal PM(10) exposure during pregnancy were 7%, 19%, 16%, 11%, 18%, 5% and 16% respectively. Because a large proportion of pregnant women in Korea are exposed to PM(10)--which is associated with LBW--a substantial proportion of LBW could be prevented in Korea if air pollution was reduced.

Interaction between GSTM1/GSTT1 polymorphism and blood mercury on birth weight

BACKGROUND

Mercury (Hg) is toxic to both the reproductive and nervous systems. In addition, glutathione S-transferases (GSTs), which conjugate glutathione to a variety of electrophilic compounds, are involved in the detoxification of Hg.

OBJECTIVE

In this study we examined the association between prenatal exposure to Hg and birth weight as well as the influence of GST polymorphisms.

METHODS

The total Hg concentration in maternal and cord blood was measured from 417 Korean women and newborns in the Mothers and Children's Environmental Health study from 2006 to 2008. Information on birth weight was collected from the patients' medical records. The genotyping of glutathione S-transferase M1 (GSTM1) and glutathione S-transferase T1 (GSTT1) polymorphisms was carried out using polymerase chain reaction. Regression analysis was performed to determine the association between the blood Hg concentration and birth weight in mothers with GSTM1 and GSTT1 polymorphisms.

RESULTS

The geometric mean levels of Hg in the maternal blood during late pregnancy and in cord blood were 3.30 microg/L and 5.53 microg/L, respectively. For mothers with the GSTT1 null genotype, elevated Hg levels in maternal blood during late pregnancy were associated with an increased risk of lower birth weight. For mothers with both GSTM1 and GSTT1 null genotype, both maternal and cord blood Hg levels were associated with lower birth weight.

CONCLUSIONS

This study suggests that the interactions of Hg with GSTM1 and GSTT1 polymorphisms play a role in reducing birth weight.

Self-expanding stent for recanalization of acute embolic or dissecting intracranial artery occlusion

BACKGROUND AND PURPOSE

Stent placement may be an effective and last resort method for recanalization of recalcitrant intracranial artery occlusion. The purpose of this study was to evaluate the safety and efficacy of a self-expanding stent for the recanalization of acute embolic or dissecting intracranial artery occlusion.

MATERIALS AND METHODS

Nine patients (mean age, 66 years; NIHSS score, 10-23) with acute embolic (n = 8) or dissecting occlusion (n = 1) of the intracranial arteries (ICA terminus in 5, MCA in 3, and BA in 1) were treated with a recapturable self-expanding stent. The safety and efficacy of the stent for recanalization were evaluated retrospectively.

RESULTS

The emboli were entrapped against the vessel wall by the stent, resulting in immediate recanalization (TIMI 2) in all embolic occlusions. The dissecting occlusion was recanalized completely (TIMI 3). Adjunctive thrombolytics (n = 8, urokinase, 100,000-300,000 U) and/or GP IIb/IIIa antagonist (n = 7, tirofiban, 0.5-1 mg) were administered intra-arterially, and the degree of recanalization further improved in 4 embolic occlusions (TIMI 3). Acute in-stent thrombosis occurred in 2 patients, who received only urokinase without GP IIb/IIIa antagonist. Both of the reoccluded arteries were reopened, by stent recapture in 1 and by intra-arterial administration of GP IIb/IIIa antagonist in the other. Recapture was attempted in 7 cases, of which there were 3 successful outcomes. There was 1 asymptomatic hemorrhagic conversion at the infarction site. The mean improvement of the NIHSS score between baseline and discharge was 12.3 (range, 3-22).

CONCLUSIONS

Preliminary results of this study suggest that a self-expanding stent may be safe and efficient for recanalization of acute embolic or dissecting intracranial artery occlusion.

Endovascular coil embolization of aneurysms with a branch incorporated into the sac

BACKGROUND AND PURPOSE

Because of the concern for occlusion of the incorporated branch artery, an aneurysm with a branch incorporated into the sac has been regarded as a contraindication for coiling. The aim of this study is to evaluate the feasibility, techniques, and clinical and angiographic outcomes of coiling for aneurysms with a branch incorporated into the sac.

MATERIALS AND METHODS

The medical records and radiologic studies of 69 patients with 79 aneurysms having a branch incorporated into the sac (26 ruptured, 53 unruptured) were retrospectively reviewed and evaluated.

RESULTS

Coiling was accomplished in 78 aneurysms in 68 patients but was suspended in 1 due to incorporated branch occlusion. The aneurysms were treated by using the following techniques: single-catheter (n = 37), multicatheter (n = 22), balloon-remodeling (n = 7), stent-assisted coiling (n = 6), and combined (n = 7). Postembolization angiography revealed the following: near-complete occlusion in 71 (89.8%), remnant neck in 4 (5.1%), and incomplete occlusion in 4 (5.1%) aneurysms. Procedure-related permanent morbidity and mortality rates were 5.8% (4/69) and 0%, respectively. All patients with unruptured aneurysms had a modified Rankin Scale (mRS) score of 0, except for 1 patient who had an mRS score of 3. Of the 26 patients with ruptured aneurysms, 18 had favorable outcome (mRS 0-2) but 8 had poor outcome (mRS 3-6). Follow-up angiography was available at least once at 6-50 months (mean, 15 months) in 55 aneurysms (69.6%), of which 45 showed stable or improved occlusion; 4, minor recurrences; and 6, major recurrences. All 6 major recurrent aneurysms were retreated without complication by using a single-catheter (n = 1), multicatheter (n = 2), or balloon-assisted technique (n = 3).

CONCLUSIONS

With appropriate techniques, most aneurysms with a branch incorporated into the sac could be safely treated by coiling, with acceptable outcomes.

Reconstructive endovascular treatment of intracranial fusiform aneurysms: a 1-stage procedure with stent and balloon

BACKGROUND AND PURPOSE

Intracranial fusiform aneurysms, which incorporate the branch vessel and require salvaging of the parent vessel, are difficult to manage. The goal of this study was to evaluate the efficacy of reconstructive endovascular treatment of intracranial fusiform aneurysms by using a 1-stage procedure with a stent and balloon.

MATERIALS AND METHODS

During a 3-year period, 20 patients with 20 intracranial fusiform aneurysms were treated by using a 1-stage procedure involving a balloon and stent. Subarachnoid hemorrhage was present in 15 patients. Five aneurysms were located in the anterior circulation and 15, in the posterior circulation. Clinical outcomes and periprocedural complications were evaluated in all patients. The extent of coil packing was evaluated by control angiography after embolization and classified as either complete occlusion or partial occlusion. Angiography was performed 6, 12, and 24 months after embolization to evaluate stent patency and coil packing.

RESULTS

The 1-stage procedure by using a combination of balloon and stent was technically successful in all patients. There were no complications related to the procedure, complete occlusion was obtained in 16 patients, and partial occlusion, in 4 patients. All patients recovered well except for 2 who died due to causes unrelated to the procedure. Clinical follow-up was performed in all surviving patients at a mean of 12.3 months (range, 7-24 months), and angiography showed that the patent parent arteries were free of aneurysm recanalization or in-stent stenosis.

CONCLUSIONS

This 1-stage procedure may provide a feasible and safe treatment strategy for the management of intracranial fusiform aneurysms that are not amenable to deconstructive embolization.

The Mothers and Children's Environmental Health (MOCEH) study

The MOCEH study is a prospective hospital- and community-based cohort study designed to collect information related to environmental exposures (chemical, biological, nutritional, physical, and psychosocial) during pregnancy and childhood and to examine how exposure to environmental pollutants affects growth, development, and disease. The MOCEH network includes one coordinating center, four local centers responsible for recruiting pregnant women, and four evaluation centers (a nutrition center, bio-repository center, neurocognitive development center, and environment assessment center). At the local centers, trained nurses interview the participants to gather information regarding their demographic and socioeconomic characteristics, complications related to the current gestation period, health behaviors and environmental factors. These centers also collect samples of blood, placenta, urine, and breast milk. Environmental hygienists measure each participant's level of exposure to indoor and outdoor pollutants during the pre- and postnatal periods. The participants are followed up through delivery and until the child is 5 years of age. The MOCEH study plans to recruit 1,500 pregnant women between 2006 and 2010 and to perform follow-up studies on their children. We expect this study to provide evidence to support the hypothesis that the gestational environment has an effect on the development of diseases during adulthood. We also expect the study results to enable evaluation of latency and age-specific susceptibility to exposure to hazardous environmental pollutants, evaluation of growth retardation focused on environmental and genetic risk factors, selection of target environmental diseases in children, development of an environmental health index, and establishment of a national policy for improving the health of pregnant women and their children.

Clinical and angiographic follow-up of stent-only therapy for acute intracranial vertebrobasilar dissecting aneurysms

BACKGROUND AND PURPOSE

Little has been known about the clinical and angiographic follow-up results of stent-only therapy for intracranial vertebrobasilar dissecting aneurysms (VBDA). The purpose of this study was to evaluate the feasibility, safety, clinical, and angiographic follow-up of stent-only therapy for VBDA.

MATERIALS AND METHODS

Twenty-seven patients with 29 VBDAs (11 ruptured, 18 unruptured), not suitable for deconstructive treatment, underwent stent-only therapy. Feasibility, safety, clinical, and angiographic follow-up were retrospectively evaluated. Angiographic outcomes were compared between single-stent and multiple-stent groups.

RESULTS

All attempted stent placements were successfully accomplished without any treatment-related complication. Of the 11 ruptured VBDAs, 4 were treated by single stents, 6 by double overlapping stents, and 1 by triple overlapping stents. Of the 18 unruptured VBDAs, 6 were treated by stents, and 12 by double overlapping stents. One patient with a ruptured VBDA, treated by single stent, had rebleeding and died. None of the remaining patients had posttreatment bleeding during follow-up (mean, 28 months; range, 7-50 months). Eight patients with ruptured VBDA and all patients with unruptured VBDA had excellent outcomes (modified Rankin Scale, 0-1). The remaining 2 patients with ruptured VBDA were moderately disabled because of the initial damage. Angiographic follow-up was available in 27 VBDAs, 4 to 42 months (mean, 12 months) after treatment. Follow-up angiograms revealed complete obliteration of the dissecting aneurysm in 12, partial obliteration in 12, stable in 1, enlargement in 1, and in-stent occlusion in 1. Angiographic improvement (complete or partial obliteration) was more frequent in the multiple-stent group (17/17) than in the single-stent group (7/9; P < .05).

CONCLUSIONS

In this small series, stent-only therapy was safe and effective in the treatment of VBDAs that were not deemed suitable for treatment with parent-artery occlusion.

Development of a sustained-release recombinant human growth hormone formulation

Recombinant human growth hormone (rhGH) therapy for short stature must be administered as a daily injection because of its poor bioavailability and short half-life. In the present study, a sustained-release formulation of rhGH (SR-rhGH), DA-3003, was prepared using double emulsion solvent evaporation with poly(D,L-lactide-co-glycolide) (PLGA), zinc oxide and hydroxypropyl-beta-cyclodextrin (HPCD) as the release modulator, stabilizer, and aggregation-prevention agent, respectively. After a single administration of DA-3003, the elevated concentration of rhGH in plasma was sustained for 14 days in rats and 28 days in monkeys. The plasma concentration of insulin-like growth factor-1 (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3), which are pharmacodynamic markers of rhGH administration, increased and remained elevated for approximately 28 days in monkeys. Monkeys administered DA-3003 did not develop antibodies to hGH, indicating safety of the SR-rhGH formulation comparable to that observed with daily rhGH injections (Growtropin II). There were no significant differences in efficacy between Growtropin II (daily dose of 5 microg/animal for 14 days) and DA-3003 (weekly dose of 35 microg/animal for 14 days with a dosing interval of a week) in hypophysectomized rats, as assessed by changes in body weight and the width of the tibial growth plate. These results show that a sustained-release rhGH formulation, DA-3003, has the potential to be used safely and efficaciously in a weekly dosing regimen.

Management and clinical outcome of acute basilar artery dissection

BACKGROUND AND PURPOSE

There have been inconsistencies on the prognosis and controversies as to the proper management of acute basilar artery dissection. The aim of this study was to evaluate acute basilar artery dissection and its outcome after management.

MATERIALS AND METHODS

A total of 21 patients (mean age, 53 years; range, 24-78 years) with acute basilar artery dissection were identified between January 2001 and October 2007. Clinical presentation, management, and outcomes were retrospectively evaluated.

RESULTS

The patients presented with subarachnoid hemorrhage (n = 10), brain stem ischemia (n = 10), or stem compression sign (n = 1). Ruptured basilar artery dissections were treated by stent placement with coiling (n = 4), single stent placement (n = 3), or conservatively (n = 3). Of the patients treated with endovascular technique, 6 had favorable outcome (modified Rankin scale [mRS], 0-2) and the remaining patient, who was treated by single stent placement, died from rebleeding. All 3 conservatively managed patients experienced rebleeding, of whom 2 died and the other was moderately disabled. Unruptured basilar artery dissections were treated conservatively (n = 7) or by stent placement (n = 4). Of the patients with unruptured basilar artery dissection, 9 had favorable outcome and the remaining 2 patients, both of whom were conservatively managed, had poor outcome because of infarct progression. The group with the ruptured basilar artery dissection revealed a higher mortality rate than the group with the unruptured dissection (30% vs 0%). The group treated with endovascular means revealed more favorable outcome than the group that was treated with conservative measures (90.9% vs 50%).

CONCLUSION

The ruptured basilar artery dissections were at high risk for rebleeding, resulting in a grave outcome. Stent placement with or without coiling may be considered to prevent rebleeding in ruptured basilar dissections and judiciously considered in unruptured dissections with signs of progressive brain stem ischemia.

Clinical outcome and ischemic complication after treatment of anterior choroidal artery aneurysm: comparison between surgical clipping and endovascular coiling

BACKGROUND AND PURPOSE

Although coiling has been favorably comparable with clipping for treatment of most intracranial aneurysms, there is a controversy on which modality is safer for anterior choroidal artery (AchoA) aneurysm. We retrospectively evaluated the clinical outcomes and treatment-related complications after surgical clipping and endovascular coiling of AchoA aneurysms.

MATERIALS AND METHODS

Seventy-three AchoA aneurysms were recruited from 1895 intracranial aneurysms, which were treated either by surgical clipping or by endovascular coiling in 4 institutions between May 1999 and December 2006. The AchoA aneurysms were dichotomized according to the modality of treatment, the coil group (37 patients; 38 aneurysms) and the clip group (35 patients; 35 aneurysms). Clinical outcomes and incidence of treatment-related complications between 2 groups and the factors influencing the clinical outcomes were evaluated.

RESULTS

There was no rebleeding in both groups during follow-up, for 4-72 months (mean, 27 months) in the coil group and for 3-84 months (mean, 34 months) in the clip group. In the coil group, 31 patients (83.8%) had favorable outcome (modified Rankin Scale score [mRS], 0-3). In the clip group, 31 patients (88.6%) had favorable outcome. The complication of coiling was transient contralateral hemiparesis in 2 patients, who recovered completely. The complications of clipping were permanent contralateral hemiparesis due to AchoA infarction in 4 patients and third-nerve palsy in 1 patient. Hunt and Hess grade 4 or 5 and AchoA infarction were significantly correlated with poor outcome (mRS, < or =4). Clipping had significantly higher incidence of AchoA infarction than coiling (P < .05).

CONCLUSION

Coiling of AchoA aneurysms appears comparable with clipping in clinical outcome and prevention of rebleeding, with significantly lower incidence of AchoA infarction than clipping.

[Environmental health surveillance of low birth weight in Seoul using air monitoring and birth data]

OBJECTIVES

The principal objective of this study was to determine the relationship between maternal exposure to air pollution and low birth weight and to propose a possible environmental health surveillance system for low birth weight.

METHODS

We acquired air monitoring data for Seoul from the Ministry of Environment, the meteorological data from the Korean Meteorological Administration, the exposure assessments from the National Institute of Environmental Research, and the birth data from the Korean National Statistical Office between January 1, 2002 and December 31, 2003. The final birth data were limited to singletons within 37-44 weeks of gestational age. We defined the Low Birth Weight (LBW) group as infants with birth weights of less than 2500g and calculated the annual LBW rate by district. The air monitoring data were measured for CO, SO(2), NO(2), and PM(10) concentrations at 27 monitoring stations in Seoul. We utilized two models to evaluate the effects of air pollution on low birth weight: the first was the relationship between the annual concentration of air pollution and low birth weight (LBW) by individual and district, and the second involved a GIS exposure model constructed by Arc View 3.1.

RESULTS

LBW risk (by Gu, or district) was significantly increased to 1.113(95% CI=1.111-1.116) for CO, 1.004 (95% CI=1.003-1.005) for NO(2), 1.202(95% CI=1.199-1.206) for SO(2), and 1.077(95% CI=1.075-1.078) for PM(10) with each interquartile range change. Personal LBW risk was significantly increased to 1.081(95% CI=1.002-1.166) for CO, 1.145(95% CI=1.036-1.267) for SO(2), and 1.053(95% CI=1.002-1.108) for PM(10) with each interquartile range change. Personal LBW risk was increased to 1.003(95% CI=0.954-1.055) for NO(2), but this was not statistically significant. The air pollution concentrations predicted by GIS positively correlated with the numbers of low birth weights, particularly in highly polluted regions.

CONCLUSIONS

Environmental health surveillance is a systemic, ongoing collection effort including the analysis of data correlated with environmentally-associated diseases and exposures. In addition, environmental health surveillance allows for a timely dissemination of information to those who require that information in order to take effective action. GIS modeling is crucially important for this purpose, and thus we attempted to develop a GIS-based environmental surveillance system for low birth weight.

Cytochrome P450IA1 polymorphisms along with PM(10) exposure contribute to the risk of birth weight reduction

We explored the effects of particulate matter <10 microm (PM(10)) exposure along with CYP1A1 polymorphisms of MspI (T6235C) and NcoI (Ile462Val) on reduced birth weight (BW). A prospective cohort study was done with women who delivered from 2001 to 2004 at Ewha Womans University Hospital, Seoul, Korea. We compared the estimated least squares means of BW in the generalized linear model, after adjusting for controlling factors. High PM(10) exposure at the 90th percentile level and above during the 1st trimester conferred a significant risk for reduced BW, compared with low PM(10) exposure below the 90th percentile level. The effect of high PM(10) exposure during the 1st trimester of pregnancy compared with low PM(10) exposure was greater for women with MspI TC/CC and NcoI IleVal/ValVal genotypes than for those with MspI TT and NcoI IleIle genotypes. In conclusion, high PM(10) exposure during the 1st trimester increased the risk for reduced BW in concert with MspI TC/CC and NcoI IleVal/ValVal genotypes in Korean women.

Effect of Graphitization on the Wettability and Electrical Conductivity of CVD-Carbon Nanotubes and Films

The use of carbon nanomaterials in various applications requires precise control of their surface and bulk properties. In this paper, we present a strategy for modifying the surface chemistry, wettability, and electrical conductivity of carbon tubes and films through annealing in a vacuum. Experiments were conducted with 60-300 nm nanotubes (nanopipes), produced by noncatalytic chemical vapor deposition (CVD) in a porous alumina template, and with thin films deposited by the same technique on a glassy carbon substrate having the same structure and chemistry of the CNTs. The surface of the as-produced CVD-carbon, treated with sodium hydroxide to remove the alumina template, is hydrophilic, and the bulk electrical conductivity is lower by a factor of 20 than that of fully graphitic multiwalled nanotubes (MWNT) or bulk graphite. The bulk electrical conductivity increases to the conductivity of graphite after annealing at 2000 degrees C in a high vacuum. The analysis of CNTs by transmission electron microscopy (TEM) and Raman spectroscopy shows the ordering of carbon accompanied by an exponential increase of the in-plane crystallite size, L(a), with increasing annealing temperature. Environmental scanning electron microscopy (ESEM) was used to study the interaction of CNT with water, and contact angle measurements performed using the sessile drop method on CVD-carbon films demonstrate that the contact angle increases nearly linearly with increasing annealing temperature.

Clusterin induces differentiation of pancreatic duct cells into insulin-secreting cells

AIMS/HYPOTHESIS

We recently reported that expression of the gene encoding clusterin (Clu) is upregulated in the regenerating pancreas, particularly in tissues undergoing differentiation. This led us to propose that clusterin participates in the cytodifferentiation of pancreatic tissue, particularly the endocrine islet cells. The aim of this study was to investigate whether clusterin induces the differentiation of duct-lining cells into insulin-secreting cells.

METHODS

We isolated ductal tissue from rat pancreas and cultured it to develop epithelial cell explants for transfection of the Clu cDNA as well as for treatment of clusterin protein.

RESULTS

The number of newly differentiated insulin cells increased 6.9-fold upon Clu overexpression compared with controls. Ins1 mRNA and peptide levels were also increased. Furthermore, glucose-stimulated insulin secretion was observed in the differentiated insulin cells. These cells were immunoreactive for insulin and C-peptide, but negative for other islet hormones and for cytokeratin-20, which indicates a fully differentiated state. Insulin cell differentiation was also increased in a dose-dependent manner by treating duct cells in culture with clusterin, indicating a growth-factor-like action of clusterin in insulin cell differentiation.

CONCLUSIONS/INTERPRETATION

These results suggest that clusterin can be considered as a potential morphogenic factor that promotes differentiation of pancreatic beta cells.

Parkinsonism as an initial manifestation of dural arteriovenous fistula

Parkinsonism associated with dural arteriovenous fistula (DAVF) has been described rarely; however, isolated parkinsonism as the presenting symptom of DAVF has not been reported. Here, we describe a patient with DAVF showing reversible isolated parkinsonism after embolization, which was well correlated with perfusion status of basal ganglia, suggesting that a perfusion defect was responsible for the pathogenesis of the parkinsonism in our DAVF patient.

[Introduction to tissue optics and optical dosimetry]

The spatial distribution of radiation during medical laser application is determined by the characteristics of the beam (power, time, beam geometry) and the optical properties of the tissue. The irradiance E (in W/m2) describes the primary laser beam. Scattered radiation, in turn, is taken into account by the fluence rate phi (also in W/m2). The basic parameters of tissue optics are the absorption coefficient mu a, the scattering coefficient mu s and the anisotropy factor g. In addition, derived parameters are also used, i.e., total attenuation coefficient mu t, reduced scattering coefficient mu s', effective attenuation coefficient mu eff, mean free path of a photon d and penetration depth delta. Further tissue properties are the diffuse reflectance Rd and the back-scattering factor k. In an one-dimensional model the fluence rate phi in tissue is a nearly exponential function characterized by the penetration depth delta. At the tissue surface, the relationship exists phi = kE. This model is compared with the results of a computer program based on the finite element method.