Independent Poor Prognostic Factors for True Progression after Radiation Therapy and Concomitant Temozolomide in Patients with Glioblastoma: Subependymal Enhancement and Low ADC Value

BACKGROUND AND PURPOSE

Subependymal enhancement and DWI have been reported to be useful MR imaging markers for identifying true progression. Our aim was to determine whether the subependymal enhancement pattern and ADC can differentiate true progression from pseudoprogression in patients with glioblastoma multiforme treated with concurrent chemoradiotherapy by using temozolomide.

MATERIALS AND METHODS

Forty-two patients with glioblastoma multiforme with newly developed or enlarged enhancing lesions on the first follow-up MR images obtained within 2 months of concurrent chemoradiotherapy completion were included. Subependymal enhancement was analyzed for the presence, location, and pattern (local or distant relative to enhancing lesions). The mean ADC value and the fifth percentile of the cumulative ADC histogram were determined. A multiple logistic regression analysis was performed to identify independent factors associated with true progression.

RESULTS

Distant subependymal enhancement (ie, extending >1 cm or isolated from the enhancing lesion) was significantly more common in true progression (n = 24) than in pseudoprogression (n = 18) (P = .042). The fifth percentile of the cumulative ADC histogram was significantly lower in true progression than in pseudoprogression (P = .014). Both the distant subependymal enhancement and the fifth percentile of the cumulative ADC histogram were independent factors associated with true progression (P = .041 and P = .033, respectively). Sensitivity and specificity for the diagnosis of true progression were 83% and 67%, respectively, by using both factors.

CONCLUSIONS

Both the distant subependymal enhancement and the fifth percentile of the cumulative ADC histogram were significant independent factors predictive of true progression.

Differentiation of Parkinsonism-Predominant Multiple System Atrophy from Idiopathic Parkinson Disease Using 3T Susceptibility-Weighted MR Imaging, Focusing on Putaminal Change and Lesion Asymmetry

BACKGROUND AND PURPOSE

Asymmetric presentation of clinical feature in parkinsonism is common, but correlatable radiologic feature is not clearly defined. Our aim was to evaluate 3T susceptibility-weighted imaging findings for differentiating parkinsonism-predominant multiple system atrophy from idiopathic Parkinson disease, focusing on putaminal changes and lesion asymmetry.

MATERIALS AND METHODS

This retrospective cohort study included 27 patients with parkinsonism-predominant multiple system atrophy and 50 patients with idiopathic Parkinson disease diagnosed clinically. Twenty-seven age-matched subjects without evidence of movement disorders who underwent SWI were included as the control group. A consensus was reached by 2 radiologists who visually assessed SWI for the presence of putaminal atrophy and marked signal hypointensity on each side of the posterolateral putamen. We also quantitatively measured putaminal width and phase-shift values.

RESULTS

The mean disease duration was 4.7 years for the patients with parkinsonism-predominant multiple system atrophy and 7.8 years for the patients with idiopathic Parkinson disease. In the patients with parkinsonism-predominant multiple system atrophy, putaminal atrophy was frequently observed (14/27, 51.9%) and was most commonly found in the unilateral putamen (13/14). Marked signal hypointensity was observed in 12 patients with parkinsonism-predominant multiple system atrophy (44.4%). No patients with idiopathic Parkinson disease or healthy controls showed putaminal atrophy or marked signal hypointensity. Quantitatively measured putaminal width, phase-shift values, and the ratio of mean phase-shift values for the dominant and nondominant sides were significantly different between the parkinsonism-predominant multiple system atrophy group and the idiopathic Parkinson disease and healthy control groups (P < .001).

CONCLUSIONS

3T SWI can visualize putaminal atrophy and marked signal hypointensity in patients with parkinsonism-predominant multiple system atrophy with high specificity. Furthermore, it clearly demonstrates the dominant side of putaminal changes, which correlate with the contralateral symptomatic side of patients.

Favorable effect of dietary vitamin C on bone mineral density in postmenopausal women (KNHANES IV, 2009): discrepancies regarding skeletal sites, age, and vitamin D status

Dietary vitamin C intake showed significant positive associations with BMD in postmenopausal women, especially with vitamin D deficiency.

INTRODUCTION

Although there is a positive role of vitamin C in osteoblastogenesis, debate remains about the contribution of vitamin C to bone mineral density (BMD) in humans.

METHODS

Data were derived from the Fourth Korean National Health and Nutrition Examination Survey. Dietary information was assessed using a 24-h dietary recall questionnaire. BMD was measured by dual-energy X-ray absorptiometry at the lumbar and hip.

RESULTS

A total of 1,196 postmenopausal women aged 50 years and older were stratified into tertiles by daily dietary vitamin C intake. After adjusting for traditional confounders, dietary vitamin C intake tertile was significantly positively associated with BMD at all sites (R = 0.513 for lumbar spine (LS) and R = 0.657 for femoral neck (FN), P < 0.05 for each). The subjects with osteoporosis had significantly lower dietary vitamin C intake than did subjects without osteoporosis (74.4 ± 66.2 vs 94.1 ± 78.6 mg/day for LS and 65.5 ± 56.6 vs 94.3 ± 79.2 mg/day for FN, respectively, P < 0.001). The multiple-adjusted odds ratio for osteoporosis for dietary vitamin C <100 mg/day was 1.790 (95 % CI 1.333-2.405, P < 0.001). However, the significant association between vitamin C intake and BMD was only observed in subjects with vitamin D deficiency and aged 50-59 years or >70 years.

CONCLUSION

Dietary vitamin C intake was positively associated with BMD in postmenopausal women, and inadequate vitamin C intake could increase the risk of osteoporosis.

Correlation of Asymmetry Indices Measured by Arterial Spin-Labeling MR Imaging and SPECT in Patients with Crossed Cerebellar Diaschisis

BACKGROUND AND PURPOSE

Crossed cerebellar diaschisis, not only a secondary result of supratentorial infarction but also an indicator of clinical outcomes, has frequently been reported on PET and SPECT but has been rarely described with arterial spin-labeling MR imaging. The purpose of this study was to determine the ability of arterial spin-labeling MR imaging to evaluate crossed cerebellar diaschisis compared with that of SPECT. To our knowledge, this is the first study to validate arterial spin-labeling in crossed cerebellar diaschisis by using SPECT as a reference standard.

MATERIALS AND METHODS

This study included 16 patients in whom crossed cerebellar diaschisis was shown on SPECT and 10 control subjects in whom crossed cerebellar diaschisis was not shown on SPECT. During the qualitative analysis, asymmetric cerebellar perfusion on arterial spin-labeling was divided into 1 of the following 3 grades by 2 blinded observers: the affected cerebellum was isointense compared with the unaffected cerebellum (grade I), it was slightly hypointense (grade II), or it was markedly hypointense (grade III). In the quantitative analysis, asymmetry indices were calculated by using SPECT and arterial spin-labeling images. For statistical analysis, κ statistics, the interobserver correlation coefficient, the independent t test, Pearson correlation, and linear regression analysis were used.

RESULTS

Almost all the diagnoses of crossed cerebellar diaschisis on SPECT were noted on arterial spin-labeling in both qualitative and quantitative analyses with good interobserver agreement (κ = 0.961; interobserver correlation coefficient, 0.806). The mean asymmetry index of arterial spin-labeling (26.06 ± 9.00) was significantly larger than that for SPECT (15.28 ± 5.34; P < .001). There was a significant positive correlation between the asymmetry indices obtained for SPECT and those for arterial spin-labeling (r = 0.77 [95% CI, 0.443-0.916]; P < .001). The relationship of asymmetry indices between SPECT and arterial spin-labeling (x, y) was calculated as y = 6.2131 + 1.2986x (R(2) = 0.592; P < .001).

CONCLUSIONS

Arterial spin-labeling can be a noninvasive alternative to SPECT for evaluating crossed cerebellar diaschisis.

Serum 25-hydroxyvitamin D level and the risk of mild cognitive impairment and dementia: the Korean Longitudinal Study on Health and Aging (KLoSHA)

OBJECTIVE

The association of low vitamin D status with mild cognitive impairment (MCI), a preclinical condition that can lead to dementia, has not yet been fully explored. Our aim was to investigate the association between vitamin D status and the future risk of MCI and dementia in older adults.

DESIGN, SETTING AND PARTICIPANTS

We conducted a population-based prospective study as a part of the Korean Longitudinal Study on Health and Aging. Four hundred and twelve elderly participants who completed evaluations of cognitive function and metabolic parameters in 2005-2006 and 2010-2011 were analysed.

MAJOR OUTCOME MEASURE

The rate of development of MCI or dementia during the study period was compared according to baseline vitamin D status. Binary logistic regression analysis was performed to investigate any independent association between vitamin D status and the risks of MCI or dementia.

RESULTS

Among 405 subjects that remained after excluding seven demented subjects at baseline, 338 subjects remained unchanged or improved in their diagnosis for cognitive function during the study period, whereas 67 subjects showed progression to MCI or dementia. When analyzing 236 subjects whose baseline mini-mental state examination (MMSE) scores were <27, severe vitamin D deficiency at baseline, defined as <25 nmol/l, was independently associated with the progression of cognitive impairment. Among 297 subjects who were normal at baseline, 50 acquired MCI and 247 remained normal. Severe vitamin D deficiency was also independently associated with the development of MCI when analyzing 145 subjects whose baseline MMSE scores were <27.

CONCLUSION

Severe vitamin D deficiency was independently associated with the future risk of MCI as well as dementia, especially in older adults whose baseline MMSE scores had decreased only modestly.

MacroH2A1 downregulation enhances the stem-like properties of bladder cancer cells by transactivation of Lin28B

The histone variant, macroH2A1, has an important role in embryonic stem cell differentiation and tumor progression in various types of tumors. However, the regulatory roles of macroH2A1 on bladder cancer progression have not been fully elucidated. Here, we show that macroH2A1 knockdown promotes stem-like properties of bladder cancer cells. The knockdown of macroH2A1 in bladder cancer cells increased tumorigenicity, radioresistance, degeneration of reactive oxygen species, increased sphere formation capability and an increase in the proportion of side populations. We found that macroH2A1 is required for the suppression of Lin28B identified as a novel downstream target of macroH2A1 in bladder cancer. Loss of macroH2A1 expression significantly correlated with the elevated levels of Lin28B expression and subsequently inhibited the mature let-7 microRNA expression. Furthermore, the stable overexpression of Lin28B enhances the several phenotypes, including tumorigenicity and sphere-forming ability, which are induced by macroH2A1 depletion. Importantly, Lin28B expression was regulated by macroH2A1-mediated reciprocal binding of p300 and EZH2/SUV39H1. Our results suggest that Lin28B/let-7 pathway is tightly regulated by macroH2A1 and its cofactors, and have a pivotal role in the bladder tumor progression and the regulation of stem-like characteristics of bladder cancer cells.

Anagliptin and sitagliptin as add-ons to metformin for patients with type 2 diabetes: a 24-week, multicentre, randomized, double-blind, active-controlled, phase III clinical trial with a 28-week extension

We conducted a 24-week, multicentre, double-blind, randomized study with a 28-week extension to compare the efficacy and safety of anagliptin and sitagliptin as an add-on to metformin in patients with type 2 diabetes. Patients inadequately controlled on metformin were randomized to either anagliptin (100 mg twice daily, n = 92) or sitagliptin (100 mg once daily, n = 88). The primary endpoint was the change in glycated haemoglobin (HbA1c) from baseline to week 24. The mean changes in HbA1c were -0.85 ± 0.70% (p < 0.0001) for anagliptin and -0.83 ± 0.61% (p < 0.0001) for sitagliptin, with a mean difference of -0.02% (95% confidence interval of difference, -0.22 to 0.18%). In both groups, the fasting proinsulin : insulin ratio significantly decreased from baseline, with improved insulin secretion. Safety profiles were similar in each group. In conclusion, the non-inferiority of the efficacy of anagliptin to sitagliptin as an add-on therapy was established with regard to efficacy and safety.

Clinical utility of arterial spin-labeling as a confirmatory test for suspected brain death

Diagnosis of brain death is made on the basis of 3 essential findings: coma, absence of brain stem reflexes, and apnea. Although confirmatory tests are not mandatory in most situations, additional testing may be necessary to declare brain death in patients in whom results of specific components of clinical testing cannot be reliably evaluated. Recently, arterial spin-labeling has been incorporated as part of MR imaging to evaluate cerebral perfusion. Advantages of arterial spin-labeling include being completely noninvasive and providing information about absolute CBF. We retrospectively reviewed arterial spin-labeling findings according to the following modified criteria based on previously established confirmatory tests to determine brain death: 1) extremely decreased perfusion in the whole brain, 2) bright vessel signal intensity around the entry of the carotid artery to the skull, 3) patent external carotid circulation, and 4) "hollow skull sign" in a series of 5 patients. Arterial spin-labeling findings satisfied the criteria for brain death in all patients. Arterial spin-labeling imaging has the potential to be a completely noninvasive confirmatory test to provide additional information to assist in the diagnosis of brain death.

Gender differences in clinical and angiographic findings of patients with Takayasu arteritis

OBJECTIVES

Because Takayasu arteritis (TA) predominantly affects females, few data regarding gender differences have been reported. The aim of the present study is to describe clinical features and angiographic findings of patients with TA according to gender.

METHODS

According to the 1990 American College of Rheumatology criteria, 294 patients were diagnosed with TA between September 1994 and April 2014 at a single tertiary hospital. We reviewed clinical, laboratory, and radiologic data at the time of diagnosis.

RESULTS

Among the 294 patients studied, 257 (87.4%) were female (male:female ratio=1:6.9). Female patients had a higher tendency to exhibit blood pressure differences between arms (p=0.595) and a weak pulse at the brachial artery (p=0.063). In male patients, we observed higher serum creatinine levels (p=0.038) and hypertension more frequently (p=0.061) than in females. Females exhibited more common lesions in the thoracic aorta and its branches, while males had more frequent lesions in the abdominal aorta and its branches. An analysis of angiographic classification according to the International TA Conference in Tokyo 1994 classification revealed that male patients had a higher incidence of type IV and females showed a higher incidence of types I, IIa, and IIb.

CONCLUSIONS

Female patients with TA have more frequent involvement of the thoracic aorta and its branches, whereas involvement of the abdominal aorta and its branches is more common in males. Considering these gender-specific differences, adjustment of diagnostic criteria for TA according to gender may be necessary.

AMPKα, C/EBPβ, CPT1β, GPR43, PPARγ, and SCD Gene Expression in Single- and Co-cultured Bovine Satellite Cells and Intramuscular Preadipocytes Treated with Palmitic, Stearic, Oleic, and Linoleic Acid

We previously demonstrated that bovine subcutaneous preadipocytes promote adipogenic gene expression in muscle satellite cells in a co-culture system. Herein we hypothesize that saturated fatty acids would promote adipogenic/lipogenic gene expression, whereas mono- and polyunsaturated fatty acids would have the opposite effect. Bovine semimembranosus satellite cells (BSC) and intramuscular preadipocytes (IPA) were isolated from crossbred steers and cultured with 10% fetal bovine serum (FBS)/Dulbecco’s Modified Eagle Medium (DMEM) and 1% antibiotics during the 3-d proliferation period. After proliferation, cells were treated for 3 d with 3% horse serum/DMEM (BSC) or 5% FBS/DMEM (IPA) with antibiotics. Media also contained 10 μg/mL insulin and 10 μg/mL pioglitazone. Subsequently, differentiating BSC and IPA were cultured in their respective media with 40 μM palmitic, stearic, oleic, or linoleic acid for 4 d. Finally, BSC and IPA were single- or co-cultured for an additional 2 h. All fatty acid treatments increased (p = 0.001) carnitine palmitoyltransferase-1 beta (CPT1β) gene expression, but the increase in CPT1β gene expression was especially pronounced in IPA incubated with palmitic and stearic acid (6- to 17- fold increases). Oleic and linoleic acid decreased (p = 0.001) stearoyl-CoA desaturase (SCD) gene expression over 80% in both BSC and IPA. Conversely, palmitic and stearic acid increased SCD gene expression three fold in co-cultured in IPA, and stearic acid increased AMPKα gene expression in single- and co-cultured BSC and IPA. Consistent with our hypothesis, saturated fatty acids, especially stearic acid, promoted adipogenic and lipogenic gene expression, whereas unsaturated fatty acids decreased expression of those genes associated with fatty acid metabolism.

Evaluation of shoulder pathology: three-dimensional enhanced T1 high-resolution isotropic volume excitation MR vs two-dimensional fast spin echo T2 fat saturation MR

OBJECTIVE

To evaluate the diagnostic accuracy of three-dimensional (3D) enhanced T1 high-resolution isotropic volume excitation (eTHRIVE) shoulder MR for the detection of rotator cuff tears, labral lesions and calcific tendonitis of the rotator cuff in comparison with two-dimensional (2D) fast spin echo T2 fat saturation (FS) MR.

METHODS

This retrospective study included 73 patients who underwent shoulder MRI using the eTHRIVE technique. Shoulder MR images were interpreted separately by two radiologists. They evaluated anatomic identification and image quality of the shoulder joint on routine MRI sequences (axial and oblique coronal T2 FS images) and compared them with the reformatted eTHRIVE images. The images were scored on a four-point scale (0, poor; 1, questionable; 2, adequate; 3, excellent) according to the degree of homogeneous and sufficient fat saturation to penetrate bone and soft tissue, visualization of the glenoid labrum and distinction of the supraspinatus tendon (SST). The diagnostic accuracy of eTHRIVE images compared with routine MRI sequences was evaluated in the setting of rotator cuff tears, glenoid labral injuries and calcific tendonitis of the SST.

RESULTS

Fat saturation scores for eTHRIVE were significantly higher than those of the T2 FS for both radiologists. The sensitivity and accuracy of the T2 FS in diagnosing rotor cuff tears were >90%, whereas sensitivity and accuracy of the eTHRIVE method were significantly lower. The sensitivity, specificity and accuracy of both images in diagnosing labral injuries and calcific tendonitis were similar and showed no significant differences. The specificity of both images for the diagnosis of labral injuries and calcific tendonitis was higher than the sensitivities.

CONCLUSION

The accuracy of 3D eTHRIVE imaging was comparable to that of 2D FSE T2 FS for the diagnosis of glenoid labral injury and calcific tendonitis of SST. The 3D eTHRIVE technique was superior to 2D FSE T2 FS in terms of fat saturation. Overall, 3D eTHRIVE was inferior to T2 FS in the evaluation of rotator cuff tears because of poor contrast between joint fluid and tendons.

ADVANCES IN KNOWLEDGE

The accuracy of 3D eTHRIVE imaging is comparable to that of 2D FSE T2 FS for the diagnosis of glenoid labral injury and calcific tendonitis of SST.

Note: in situ parameter extraction from a nonlinear dynamic model for electrical characterization of organic light emitting diodes

This Note presents a nonlinear device model for organic light emitting diodes (OLEDs), which can describe dynamic and static characteristics of OLEDs consistently. The parameters of the proposed model are estimated by using a particle swarm optimization algorithm. Some of the resulting parameters relate with physical characteristics of OLEDs. With only one set of experiments leading to a time response of an OLED device, this nonlinear model, together with all the parameters, is obtained, which can be a big advantage for the fast quality control of the OLEDs.

Hierarchical MoSe₂ yolk-shell microspheres with superior Na-ion storage properties

Yolk-shell-structured MoSe₂ microspheres were prepared via a simple selenization process of MoO₃ microspheres. The yolk-shell-structured MoSe₂ and MoO₃ microspheres delivered initial discharge capacities of 527 and 465 mA h g(-1) in the voltage range of 0.001-3 V vs. Na/Na(+) at a current density of 0.2 A g(-1), respectively, and their discharge capacities after 50 cycles were 433 and 141 mA h g(-1), respectively. The yolk-shell-structured MoSe₂ microspheres also exhibited outstanding high rate capabilities. The hierarchical yolk-shell structure comprised of wrinkled nanosheets facilitated fast Na-ion and electron kinetics, and buffered the large volume changes encountered during cycling.

Influence of Cavity Preparation, Light-curing Units, and Composite Filling on Intrapulpal Temperature Increase in an In Vitro Tooth Model

This study examined the effect of both the tooth substance and restorative filling materials on the increase in pulp chamber temperature when using light-curing units with different power densities.

The tip of a temperature sensor was positioned on the pulpal dentinal wall of the buccal side of a maxillary premolar. Metal tubes were inserted in the palatal and buccal root of the tooth, one for water inflow and the other for water outflow. Polyethylene tubes were connected from the metal tubes to a pump to control the flow rate. For the unprepared tooth group (group 1), the tooth was light-cured from the buccal side using two light-curing units (three curing modes): the VIP Junior (QTH, BISCO, Schaumburg, IL, USA) and the Bluephase LED light-curing units (two modes: LEDlow and LEDhigh; Ivoclar Vivadent, Schaan, Liechtenstein). The power densities of each light-curing unit for the LEDlow, QTH, and LEDhigh modes were 785 mW/cm2, 891 mW/cm2, and 1447 mW/cm2, respectively. All light-curing units were activated for 60 seconds. For the prepared tooth group (group 2), a Class V cavity, 4.0 mm in width by 4.0 mm in height by 1.8 mm in depth in size, was prepared on the buccal surface of the same tooth for the temperature measurement. The light-curing and temperature measurements were performed using the same methods used in group 1.

The cavity prepared in group 2 was filled with a resin composite (Tetric N Ceram A3 shade, Ivoclar Vivadent) (group 3) or a flowable composite (Tetric N Flow with A3 shade, Ivoclar Vivadent) (group 4). The light-curing and temperature measurements were performed for these groups using the same methods used for the other groups.

The highest intrapulpal temperature (TMAX) was measured, and a comparison was conducted between the groups using two-way analysis of variance with a post hoc Tukey test at the 95% confidence level.

The TMAX values were as follows: 38.4°C (group 1), 39.0°C (group 2), 39.8°C (group 3), and 40.3°C (group 4) for the LEDlow mode. For the QTH mode, the TMAX values were 40.1°C (group 1), 40.4°C (group 2), 40.9°C (group 3), and 41.4°C (group 4). For the LEDhigh mode, the TMAX values were 43.3°C (group 1), 44.5°C (group 2), 44.7°C (group 3), and 45.3°C (group 4). The statistical analysis revealed the following: the TMAX values were arranged by mode in the following manner: LEDlow &lt; QTH &lt; LEDhigh (p&lt;0.05) and group 1 &lt; group 2 ≤ group 3 ≤ group 4 (p&lt;0.05).

Surgical treatment of solid pseudopapillary neoplasms of the pancreas and risk factors for malignancy

BACKGROUND

The aim of this study was to identify clinical predictors of malignancy and surgical strategies for pancreatic solid pseudopapillary neoplasm (SPN) by analysis of surgical outcomes at a single institution.

METHODS

All patients who underwent surgery for SPN between 1995 and 2010 were identified. Histopathology slides of all patients were reviewed by a specialized pathologist and the neoplasms were classified according to the criteria of the World Health Organization 2010.

RESULTS

Of the 106 patients identified, 85 (80·2 per cent) were female, and the median age was 36 (range 10-65) years. Median tumour size was 4·5 (range 1·0-15·0) cm. Some 17 patients (16·0 per cent) were classified as having a high-grade malignant SPN. Tumour size of at least 5 cm was associated with high-grade malignant potential (P = 0·022). Although lymph nodes were removed from 40 patients (37·7 per cent), there were no nodal metastases. A total of five patients underwent en bloc resection of adjacent structures, including two with portal vein involvement. After a median follow-up of 56·9 months, two patients with high-grade malignant SPN had evidence of tumour recurrence in the lymph nodes and liver.

CONCLUSION

SPN with a diameter of 5 cm or more is associated with a high-grade malignant phenotype. Complete surgical removal is associated with low recurrence rates.

Glioma: Application of histogram analysis of pharmacokinetic parameters from T1-weighted dynamic contrast-enhanced MR imaging to tumor grading

BACKGROUND AND PURPOSE

The usefulness of pharmacokinetic parameters for glioma grading has been reported based on the perfusion data from parts of entire-tumor volumes. However, the perfusion values may not reflect the entire-tumor characteristics. Our aim was to investigate the feasibility of glioma grading by using histogram analyses of pharmacokinetic parameters including the volume transfer constant, extravascular extracellular space volume per unit volume of tissue, and blood plasma volume per unit volume of tissue from T1-weighted dynamic contrast-enhanced perfusion MR imaging.

MATERIALS AND METHODS

Twenty-eight patients (14 men, 14 women; mean age, 49.75 years; age range, 25-72 years) with histopathologically confirmed gliomas (World Health Organization grade II, n = 7; grade III, n = 8; grade IV, n = 13) were examined before surgery or biopsy with conventional MR imaging and T1-weighted dynamic contrast-enhanced perfusion MR imaging at 3T. Volume transfer constant, extravascular extracellular space volume per unit volume of tissue, and blood plasma volume per unit volume of tissue were calculated from the entire-tumor volume. Histogram analyses from these parameters were correlated with glioma grades. The parameters with the best percentile from cumulative histograms were identified by analysis of the area under the curve of the receiver operating characteristic analysis and were compared by using multivariable stepwise logistic regression analysis for distinguishing high- from low-grade gliomas.

RESULTS

All parametric values increased with increasing glioma grade. There were significant differences among the 3 grades in all parameters (P < .01). For the differentiation of high- and low-grade gliomas, the highest area under the curve values were found at the 98th percentile of the volume transfer constant (area under the curve, 0.912; cutoff value, 0.277), the 90th percentile of extravascular extracellular space volume per unit volume of tissue (area under the curve, 0.939; cutoff value, 19.70), and the 84th percentile of blood plasma volume per unit volume of tissue (area under the curve, 0.769; cutoff value, 11.71). The 98th percentile volume transfer constant value was the only variable that could be used to independently differentiate high- and low-grade gliomas in multivariable stepwise logistic regression analysis.

CONCLUSIONS

Histogram analysis of pharmacokinetic parameters from whole-tumor volume data can be a useful method for glioma grading. The 98th percentile value of the volume transfer constant was the most significant measure.

Tunable symmetry breaking and helical edge transport in a graphene quantum spin Hall state

Low-dimensional electronic systems have traditionally been obtained by electrostatically confining electrons, either in heterostructures or in intrinsically nanoscale materials such as single molecules, nanowires and graphene. Recently, a new method has emerged with the recognition that symmetry-protected topological (SPT) phases, which occur in systems with an energy gap to quasiparticle excitations (such as insulators or superconductors), can host robust surface states that remain gapless as long as the relevant global symmetry remains unbroken. The nature of the charge carriers in SPT surface states is intimately tied to the symmetry of the bulk, resulting in one- and two-dimensional electronic systems with novel properties. For example, time reversal symmetry endows the massless charge carriers on the surface of a three-dimensional topological insulator with helicity, fixing the orientation of their spin relative to their momentum. Weakly breaking this symmetry generates a gap on the surface, resulting in charge carriers with finite effective mass and exotic spin textures. Analogous manipulations have yet to be demonstrated in two-dimensional topological insulators, where the primary example of a SPT phase is the quantum spin Hall state. Here we demonstrate experimentally that charge-neutral monolayer graphene has a quantum spin Hall state when it is subjected to a very large magnetic field angled with respect to the graphene plane. In contrast to time-reversal-symmetric systems, this state is protected by a symmetry of planar spin rotations that emerges as electron spins in a half-filled Landau level are polarized by the large magnetic field. The properties of the resulting helical edge states can be modulated by balancing the applied field against an intrinsic antiferromagnetic instability, which tends to spontaneously break the spin-rotation symmetry. In the resulting canted antiferromagnetic state, we observe transport signatures of gapped edge states, which constitute a new kind of one-dimensional electronic system with a tunable bandgap and an associated spin texture.

Splenic vein thrombosis and pancreatic fistula after minimally invasive distal pancreatectomy

BACKGROUND

This study aimed to investigate the clinical relevance of splenic vein thrombosis (SVT) in the splenic vein remnant following minimally invasive distal pancreatosplenectomy (DPS).

METHODS

Medical records of patients who underwent laparoscopic or robotic distal pancreatectomy (DP) with or without splenectomy between January 2006 and August 2012 were reviewed. Rates of SVT and clinically relevant postoperative pancreatic fistula (POPF) were compared in a group of patients undergoing DPS and a group having spleen-preserving DP.

RESULTS

Seventy-nine patients had minimally invasive DP, of whom 38 (48 per cent) developed SVT in the splenic vein remnant. DPS was associated with POPF (P = 0.001) and SVT (P < 0.001). SVT length was closely related to the amount of peripancreatic fluid collection (P = 0.025) and POPF (P = 0.045). In a comparison of splenic vessel-sacrificing, spleen-preserving DP and DPS, postoperative platelet count was significantly higher in the DPS group (P < 0.001). In addition, grade of SVT (P = 0.092) and POPF (P = 0.065) tended to be associated with DPS, suggesting that SVT may be related to both splenectomy and POPF.

CONCLUSION

Minimally invasive DPS is associated with SVT and POPF. Preservation of the spleen should be considered when treating patients with benign and borderline malignant tumours of the distal pancreas.

Meta-analysis of 74,046 individuals identifies 11 new susceptibility loci for Alzheimer's disease

Eleven susceptibility loci for late-onset Alzheimer's disease (LOAD) were identified by previous studies; however, a large portion of the genetic risk for this disease remains unexplained. We conducted a large, two-stage meta-analysis of genome-wide association studies (GWAS) in individuals of European ancestry. In stage 1, we used genotyped and imputed data (7,055,881 SNPs) to perform meta-analysis on 4 previously published GWAS data sets consisting of 17,008 Alzheimer's disease cases and 37,154 controls. In stage 2, 11,632 SNPs were genotyped and tested for association in an independent set of 8,572 Alzheimer's disease cases and 11,312 controls. In addition to the APOE locus (encoding apolipoprotein E), 19 loci reached genome-wide significance (P < 5 × 10(-8)) in the combined stage 1 and stage 2 analysis, of which 11 are newly associated with Alzheimer's disease.

Germline mutations and genotype-phenotype correlations in patients with apparently sporadic pheochromocytoma/paraganglioma in Korea

The aim of our study was to assess the frequency of germline mutations and develop the genetic testing strategy in patients with apparently sporadic pheochromocytoma/paraganglioma (PPGL) in Korea. We included 53 patients diagnosed with non-syndromic PPGL without a family history of PPGLs in three referral centers from 2004 to 2011. Succinate dehydrogenase complex B (SDHB), SDHD, Von Hippel-Lindau (VHL), and rearranged during transfection (RET) genes were examined by direct sequencing and multiple ligation-dependent probe amplification. The study patients were composed of 26 men and 27 women, and mean age was 50.1 ± 13.5 years. The frequency of germline mutations was 13.2% (7/53): RET (n = 2), VHL (n = 1), SDHB (n = 2), and SDHD (n = 2). Six of seven mutation carriers were diagnosed before the age of 50. One of two patients harboring an SDHB mutation had malignant PPGLs. One patient with multifocal head and neck paraganglioma (PGL) and pheochromocytoma (PHEO) carried a SDHD mutation. The carriers of germline mutations in patients with apparently sporadic PPGL were 13.2% in our study. We recommend genetic testing in patients below 50 years and SDHD genetic testing in patients with multifocal PPGLs. In malignant PPGLs, SDHB genetic testing may be performed.

Socioeconomic disparities of periodontitis in Koreans based on the KNHANES IV

OBJECTIVES

The aim of this study was to identify the socioeconomic factors associated with the prevalence of periodontitis in Koreans.

METHODS

Cross-sectional data from 12 763 subjects, 15 years old and above, who underwent periodontal examinations were obtained from the Korean National Health and Nutrition Examination Survey IV (2007-209). Multivariate linear and logistic regression analyses were applied to estimate the association between socioeconomic indicators and prevalence of periodontitis.

RESULTS

A significant association was found between increasing age and periodontitis. Participants with higher income were less likely to have periodontitis (aOR = 0.9 and 95% CI = 0.78-0.98, and aOR = 0.7 and 95% CI = 0.60-0.80 in the middle and highest quintiles of monthly household income, respectively). In addition, participants living in rural areas were less likely to have periodontitis (aOR = 0.9 and 95% CI = 0.81-0.99), and current smokers were more likely to have periodontitis (aOR = 1.7 and 95% CI = 1.49-1.89). The analysis of comorbidities revealed that individuals with diabetes mellitus (DM) were significantly more likely to have periodontitis (aOR = 1.4 and 95% CI = 1.18-1.68).

CONCLUSIONS

In a rapidly increasing Korean population, the lower socioeconomic groups as well as individuals with DM were significantly more likely to present with periodontitis.

Establishment of isolation and expansion protocols for human cardiac C-kit-positive progenitor cells for stem cell therapy

Although cardiac stem cells (CSCs) have emerged in regeneration research, the number of isolated CSCs is low, making a sufficient supply of functional elements an important consideration in cardiovascular research. In this study, we established an efficient method for CSC isolation. We directly compared cultures of single cells to human cardiac-derived c-kit-positive progenitor cells (hCPCs(c-kit+)). The two protocols employed enzymatically digested hCPCs(c-kit+) (ED-hCPCs) with tissue-expanded hCPC(c-kit+) (TE-hCPCs). Using fluorescence-activated cell sorting, we showed the concentration of c-kit in TE-hCPCs to be higher than in ED-hCPCs, although the total number of c-kit positive cells resulting from ED-hCPCs was similar to that resulting from TE-hCPCs. The cardiomyocyte-associated proteins, GATA4 and Nkx2-5, which were expressed during hCPCs expansion, did not differ between the isolation methods. Importantly, the expression of the CSC stem cell marker, c-kit, was more efficiently preserved using the ED-hCPCs versus the TE-hCPCs method. In a cell proliferation assay, the ED-hCPCs method produced a significantly greater number of cells. Finally, hCPCs derived using both protocols differentiated into endothelial, smooth muscle, and cardiomyocyte lineages. In conclusion, the single-cell culture protocol using an enzymatic digestion method may be more useful to isolate human cardiac-derived c-kit-positive elements compared with the tissue expansion method.

Effect of Mn and P on the macroscopic texture of Ti-Nb stabilized interstitial free steels

The effect of Mn and P on the macroscopic texture of Ti-Nb stabilized IF steels was investigated. In order to examine the evolution of microstructure and macroscopic texture during the hot-rolling, cold-rolling and annealing processes, microstructure characterization was conducted for hot-rolled, cold-rolled and annealed specimens. The initial grain size of hot-rolled specimens was a main parameter in determining the development of the macroscopic texture of the annealed specimens.