Longitudinal Findings of MRI and PET in West Syndrome with Subtle Focal Cortical Dysplasia

BACKGROUND AND PURPOSE

Despite the development of neuroimaging, identification of focal cortical dysplasia remains challenging. The purpose of this study was to show the longitudinal changes of MR imaging and FDG-PET in patients with West syndrome and subtle focal cortical dysplasia.

MATERIALS AND METHODS

Among 52 consecutive patients with West syndrome, 4 were diagnosed with subtle focal cortical dysplasia on 3T MR imaging. MR imaging and PET findings were evaluated longitudinally at onset and at 12 and 24 months of age.

RESULTS

At the onset of West syndrome, MR imaging demonstrated focal signal abnormalities of the subcortical white matter in 2 patients. In the other 2 patients, focal subcortical high-intensity signals became visible on follow-up T2WI as myelination progressed. PET at onset showed focal cortical hypometabolism in 3 patients, with 1 of these patients also having focal hypermetabolism and 1 having normal findings. On PET at 24 months, hypometabolism persisted in 2 patients and disappeared in 1, and hypermetabolism disappeared in 1. In 1 patient with normal MR imaging and PET findings at onset, focal hyperintensity and hypometabolism first appeared at 24 months of age. The findings on MR imaging and PET in these patients evolved differently with brain maturation and the clinical course.

CONCLUSIONS

Subtle focal cortical dysplasia can be undetectable on MR imaging at the onset of West syndrome and is not always accompanied by hypometabolism or hypermetabolism on PET. Longitudinal MR imaging and PET studies may be useful for detecting such lesions. Even in West syndrome with a congenital structural abnormality, PET findings evolve differently with brain maturation and the clinical condition.

Development of models to predict fish early-life stage toxicity from acute Daphnia magna toxicity$

Herein, we propose models for predicting fish early-life stage (ELS) toxicity from acute Daphnia magna toxicity and various molecular descriptors. Specifically, eight models were developed with fathead minnow (Pimephales promelas) data and were validated against Japanese medaka (Oryzias latipes) data because the quantity of available Japanese medaka data is much smaller than the quantity of fathead minnow data. The training data set for the models consisted of ELS fathead minnow toxicity data for 77 chemicals; data for 67 of the 77 chemicals originated from the OPP Pesticide Ecotoxicity Database of the US Environmental Protection Agency. The training data were biased toward pesticides. A simple quantitative activity-activity relationship (QAAR) model based on the correlation between fish ELS and acute Daphnia magna toxicities showed good predictivity for the chemicals in the external validation data set relative to the predictivities of the other models in this study. However, goodness-of-fit and robustness were better for quantitative structure-activity-activity relationship (QSAAR) models that included molecular descriptors (such as pesticide-related atoms and substructures as well as molecular weight and three-dimensional-structure-based parameters). A battery approach involving the use of both the QAAR and the QSAARs might enhance the reliability of the estimated values and prevent underestimates.

Colossal Negative Thermal Expansion in Electron-Doped PbVO3 Perovskites

Colossal negative thermal expansion (NTE) with a volume contraction of about 8 %, the largest value reported so far for NTE materials, was observed in an electron-doped giant tetragonal perovskite compound Pb_1-x Bi_x VO₃ (x=0.2 and 0.3). A polar tetragonal (P4mm) to non-polar cubic structural transition took place upon heating. The coefficient of thermal expansion (CTE) and the working temperature could be tuned by changing the Bi content, and La substitution decreased the transition temperature to room temperature. Pb_0.76 La_0.04 Bi_0.20 VO₃ exhibited a unit cell volume contraction of 6.7 % from 200 K to 420 K. Interestingly, further gigantic NTE of about 8.5 % was observed in a dilametric measurement of a Pb_0.76 La_0.04 Bi_0.20 VO₃ polycrystalline sample. The pronounced NTE in the sintered body should be attributed to an anisotropic lattice parameter change.

Slow Progression of Aortic Calcification Is a Potential Benefit of Pre-emptive Kidney Transplantation

PURPOSE

Pre-emptive kidney transplantation (PKT) is expected to improve graft and cardiovascular event-free survival compared with standard kidney transplantation. Aortic calcification is reported to be closely associated with renal dysfunction and cardiovascular events; however, its implication in PKT recipients remains incompletely explored. This aim of this study was to evaluate whether PKT confers a protective effect on aortic calcification, renal function, graft survival, and cardiovascular event-free survival.

METHODS

One hundred adult patients who underwent renal transplantation between January 1996 and March 2016 at Hirosaki University Hospital and Oyokyo Kidney Research Institute were included. Among them, 19 underwent PKT and 81 patients underwent pretransplant dialysis. We retrospectively compared pretransplant and post-transplant aortic calcification index (ACI), renal function (estimated glomerular filtration rate [eGFR]), and graft and cardiovascular event-free survivals between the 2 groups.

RESULTS

The median age of this cohort was 45 years. Preoperative ACI was significantly lower in PKT recipients. There were no significant differences between the 2 groups regarding postoperative eGFR, graft survival, and cardiovascular event-free survival. However, the ACI progression rate (ΔACI/y) was significantly lower in PKT recipients than in those who underwent pretransplant dialysis. Higher ACI was significantly associated with poor cardiovascular event-free survival.

CONCLUSIONS

PKT is beneficial in that it contributes to the slow progression of after transplantation. Although we could not observe significant differences in graft and cardiovascular event-free survivals between the 2 groups, slow progression of aortic calcification showed a potential to decrease cardiovascular events in PKT recipients during long-term follow-up.

Electronic Structure of Ce-Doped and -Undoped Nd_{2}CuO_{4} Superconducting Thin Films Studied by Hard X-Ray Photoemission and Soft X-Ray Absorption Spectroscopy

In order to realize superconductivity in cuprates with the T^{'}-type structure, not only chemical substitution (Ce doping) but also postgrowth reduction annealing is necessary. In the case of thin films, however, well-designed reduction annealing alone without Ce doping can induce superconductivity in the T^{'}-type cuprates. In order to unveil the origin of superconductivity in the Ce-undoped T^{'}-type cuprates, we have performed bulk-sensitive hard x-ray photoemission and soft x-ray absorption spectroscopy on superconducting and nonsuperconducting Nd_{2-x}Ce_{x}CuO_{4} (x=0, 0.15, and 0.19) thin films. By postgrowth annealing, core-level spectra exhibited dramatic changes, which we attributed to the enhancement of core-hole screening in the CuO_{2} plane and the shift of chemical potential along with changes in the band filling. The result suggests that the superconducting Nd_{2}CuO_{4} film is doped with electrons despite the absence of the Ce substitution.

Development of Bismuth Ferrite as a Piezoelectric and Multiferroic Material by Cobalt Substitution

Bismuth ferrite (BiFeO3 ) is the most widely studied multiferroic material with robust ferroelectricity and antiferromagnetic ordering at room temperature. One of the possible device applications of this material is one that utilizes the ferroelectric/piezoelectric property itself such as ferroelectric memory components, actuators, and so on. Other applications are more challenging and make full use of its multiferroic property to realize novel spintronics and magnetic memory devices, which can be addressed electrically as well as magnetically. This progress report summarizes the recent attempt to control the piezoelectric and magnetic properties of BiFeO3 by cobalt substitution.

Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω_{0}^{T}<5.58×10^{-8}, Ω_{0}^{V}<6.35×10^{-8}, and Ω_{0}^{S}<1.08×10^{-7} at a reference frequency f_{0}=25  Hz.

Reappraisal of classification of distal cholangiocarcinoma based on tumour depth

Background

In the eighth edition of the AJCC cancer staging classification, the T system for distal cholangiocarcinoma (DCC) has been revised from a layer-based to a depth-based approach. The aim of this study was to propose an optimal T classification using a measured depth in resectable DCC.

Methods

Patients who underwent pancreatoduodenectomy for DCC at 32 hospitals between 2001 and 2010 were included. The distance between the level of the naive bile duct and the deepest cancer cells was measured as depth of invasion (DOI). Invasive cancer foci were measured as invasive tumour thickness (ITT). Log rank χ2 scores were used to determine the cut-off points, and concordance index (C-index) to assess the survival discrimination of each T system.

Results

Among 404 patients, DOI was measurable in 182 (45·0 per cent) and ITT was measurable in all patients, with median values of 2·3 and 5·6 mm respectively. ITT showed a positive correlation with DOI (rs = 0·854, P &lt; 0·001), and the cut-off points for prognosis were 1, 5 and 10 mm. Median survival time was shorter with increased ITT: 12·4 years for ITT below 1 mm, 5·2 years for ITT at least 1 mm but less than 5 mm, 3·0 years for ITT at least 5 mm but less than 10 mm, and 1·5 years for ITT 10 mm or more (P &lt; 0·001). This classification exhibited more favourable prognostic discrimination than the T systems of the seventh and eighth editions of the AJCC (C-index 0·646, 0·622 and 0·624 respectively).

Conclusion

ITT is an accurate approach for depth assessment in DCC. The four-tier ITT classification with cut-off points of 1, 5 and 10 mm seems to be a better T system than those in the seventh and eighth editions of the AJCC classification.

Partial Cystectomy of Paraganglioma of the Urinary Bladder Before Living Kidney Transplantation: Case Report

BACKGROUND

Paraganglioma (extra-adrenal pheochromocytoma) of the bladder is a very rare disease, accounting for 0.06% of all bladder tumors. Optimal management of bladder paraganglioma before kidney transplantation is unknown. We report a case of partial cystectomy for urinary bladder paraganglioma before living kidney transplantation.

CASE PRESENTATION

A 59-year-old man with a 27-year history of hemodialysis was referred to our department for further examination of a bladder tumor detected during pre-transplantation testing. Cystoscopy revealed a submucosal tumor on the right side of the bladder. The patient experienced a hypertensive crisis during transurethral resection of the bladder tumor. Endocrinologic and pathologic examinations confirmed the diagnosis of paraganglioma in the urinary bladder. A partial cystectomy was performed before kidney transplantation. Nine months after partial cystectomy, the patient underwent AB0-incompatible living kidney transplantation from his spouse. No disease recurrence or graft rejection was observed 12 months after the transplantation.

CONCLUSIONS

To our knowledge, this is the 1st report on the management of paraganglioma in the urinary bladder before living kidney transplantation. Kidney transplantation after partial cystectomy is an option that may be considered in patients with paraganglioma of the urinary bladder, with careful observations of bladder function and vesicoureteral reflux to the grafts.

Condyloma Acuminata of the Urethra in a Male Renal Transplant Recipient: A Case Report

BACKGROUND

Condyloma acuminatum (CA) is a common sexually transmitted disease associated with human papilloma virus (HPV). CA occurring in the urethra is rare and has not been reported in male renal transplant recipients. In addition, despite immunosuppressive conditions and increased risk of HPV-related malignant neoplasms in transplant recipients, HPV testing in male transplant recipients has been uncommon. Here we report a case of urethral CA in a male deceased donor renal transplantation recipient and discuss the importance of HPV testing in male transplant recipients.

CASE PRESENTATION

A 33-year-old male deceased donor renal transplant recipient presented with miction pain 5 years after the transplantation. He reported repeated urinary tract infections with no sexual contact since the renal transplantation. Multiple papillary tumors in his penile urethra were detected by cystoscopy, and a biopsy sample was pathologically diagnosed with CA. Transurethral tumor resection was performed, and the tumors were completely resected. Additional HPV risk type screening with a urethral smear sample showed the prevalence of low-risk HPV. Although tacrolimus was switched to everolimus and imiquimod cream was administered, the tumors recurred 6 months after the resection, and a second resection was performed. No further recurrence has been observed for 1 year to date.

CONCLUSION

As the urethral CA was possibly related to immunosuppressive conditions and a risk for HPV-related malignant neoplasm, the case required careful diagnosis, including HPV risk type. The methodology of sampling for HPV testing in men has not been established. This case suggests the necessity for further discussion about HPV testing in male transplant recipients.

GW170817: Implications for the Stochastic Gravitational-Wave Background from Compact Binary Coalescences

The LIGO Scientific and Virgo Collaborations have announced the event GW170817, the first detection of gravitational waves from the coalescence of two neutron stars. The merger rate of binary neutron stars estimated from this event suggests that distant, unresolvable binary neutron stars create a significant astrophysical stochastic gravitational-wave background. The binary neutron star component will add to the contribution from binary black holes, increasing the amplitude of the total astrophysical background relative to previous expectations. In the Advanced LIGO-Virgo frequency band most sensitive to stochastic backgrounds (near 25 Hz), we predict a total astrophysical background with amplitude Ω_{GW}(f=25  Hz)=1.8_{-1.3}^{+2.7}×10^{-9} with 90% confidence, compared with Ω_{GW}(f=25  Hz)=1.1_{-0.7}^{+1.2}×10^{-9} from binary black holes alone. Assuming the most probable rate for compact binary mergers, we find that the total background may be detectable with a signal-to-noise-ratio of 3 after 40 months of total observation time, based on the expected timeline for Advanced LIGO and Virgo to reach their design sensitivity.

Measurements of Multiparticle Correlations in d+Au Collisions at 200, 62.4, 39, and 19.6 GeV and p+Au Collisions at 200 GeV and Implications for Collective Behavior

Recently, multiparticle-correlation measurements of relativistic p/d/^{3}He+Au, p+Pb, and even p+p collisions show surprising collective signatures. Here, we present beam-energy-scan measurements of two-, four-, and six-particle angular correlations in d+Au collisions at sqrt[s_{NN}]=200, 62.4, 39, and 19.6 GeV. We also present measurements of two- and four-particle angular correlations in p+Au collisions at sqrt[s_{NN}]=200  GeV. We find the four-particle cumulant to be real valued for d+Au collisions at all four energies. We also find that the four-particle cumulant in p+Au has the opposite sign as that in d+Au. Further, we find that the six-particle cumulant agrees with the four-particle cumulant in d+Au collisions at 200 GeV, indicating that nonflow effects are subdominant. These observations provide strong evidence that the correlations originate from the initial geometric configuration, which is then translated into the momentum distribution for all particles, commonly referred to as collectivity.

First Search for Nontensorial Gravitational Waves from Known Pulsars

We present results from the first directed search for nontensorial gravitational waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of gravitational waves of any polarization. We report the first upper limits for scalar and vector strains, finding values comparable in magnitude to previously published limits for tensor strain. Our results may be translated into constraints on specific alternative theories of gravity.