Clinical Experience of 1-Minute Brain MRI Using a Multicontrast EPI Sequence in a Different Scan Environment.

BACKGROUND AND PURPOSE: The long scan time of MR imaging is a major drawback limiting its clinical use in neuroimaging; therefore, we aimed to investigate the clinical feasibility of a 1-minute full-brain MR imaging using a multicontrast EPI sequence on a different MR imaging scanner than the ones previously reported. MATERIALS AND METHODS: We retrospectively reviewed the records of 146 patients who underwent a multicontrast EPI sequence, including T1-FLAIR, T2-FLAIR, T2WI, DWI, and T2*WI sequences. Two attending neuroradiologists assessed the image quality of each sequence to compare the multicontrast EPI sequence with routine MR imaging protocols. We used the Wilcoxon signed rank test and McNemar test to compare the 2 MR imaging protocols. RESULTS: The multicontrast EPI sequence generally showed sufficient image quality of >2 points using a 4-point assessment scale. Regarding image quality and susceptibility artifacts, there was no significant difference between the multicontrast EPI sequence DWI and routine DWI (P > .05), attesting to noninferiority of the multicontrast EPI, whereas there were significant differences in the other 4 sequences between the 2 MR imaging protocols. CONCLUSIONS: The multicontrast EPI sequence showed sufficient image quality for clinical use with a shorter scan time; however, it was limited by inferior image quality and frequent susceptibility artifacts compared with routine brain MR imaging. Therefore, the multicontrast EPI sequence cannot completely replace the routine MR imaging protocol at present; however, it may be a feasible option in specific clinical situations such as screening, time-critical diseases or for use with patients prone to motion.

Factors Associated With Waiting Time to Deceased Donor Kidney Transplantation in Transplant Candidates.

Although a nationwide activation system has been developed to increase deceased donor kidney transplantation (DDKT), there is still enormous discrepancy between transplant need and deceased donor supply in Korea, and therefore waiting time to DDKT is still long. We need to determine the current status of waiting time and the risk factors for long waiting time. We retrospectively analyzed the medical records of the patients on the wait list for DDKT at the Seoul National University Hospital from 2000 to 2017. Among 2,211 wait-listed patients, 606 (27.5%) received DDKT and mean waiting time to DDKT was 45 months. Among them, blood type A was most prevalent (35.6%) and type AB was the least (14.0%). Panel-reactive assay (PRA) was positive in 59 (11.0%) in the first transplant group and 25 (35.0%) in retransplant group. Waiting time in PRA-positive recipients was 63 and 66 months in the first transplant group and retransplant group, respectively. However, waiting time for patients with negative PRA was 42.8 months. Waiting time was shorter in blood type AB (39 months) than other types (46 months). Waiting time was the shortest in children and adolescents. Among patients who were still on the wait list, retransplantation candidates, especially with PRA higher than 50%, had longer waiting time than first transplant candidates. In conclusion, non-AB blood type, positive PRA, and adult age were significantly associated with long waiting time. Therefore, it is necessary to establish a management strategy such as tailored desensitization for highly sensitized patients on the wait list to reduce their waiting time.

Fabrication of Flexible Superconducting Wiring with High Current-Carrying Capacity Indium Interconnects.

The X-ray integral field unit (X-IFU) is a cryogenic spectrometer for the Advanced Telescope for High ENergy Astrophysics (ATHENA). ATHENA is a planned next-generation space-based X-ray observatory with capabilities that surpass the spectral resolution of prior missions. Proposed device designs contain up to 3840 transition edge sensors, each acting as an individual pixel on the detector, presenting a unique challenge for wiring superconducting leads in the focal plane assembly. In prototypes that require direct wiring, the edges of X-IFU focal plane have hosted aluminum wirebonding pads; however, indium (In) 'bumps' deposited on an interface layer such as molybdenum nitride (MoN) can instead be used as an array of superconducting interconnects. We investigated bumped MoN:In structures with different process cleans and layer thicknesses. Measurements of the resistive transitions showed variation of transition temperature T c as a function of bias and generally differed from the expected bulk T c of In (3.41 K). Observed resistance of the In bump structures at temperatures below the MoN transition (at 8.0 K) also depended on the varied parameters. For our proposed X-IFU geometry (10 µm of In mated to a 1-µm In bump), we measured a minimum T c of 3.14 K at a bias current of 3 mA and a normal resistance of 0.59 mΩ per interconnect. We also investigated the design and fabrication of superconducting niobium (Nb) microstrip atop flexible polyimide. We present a process for integrating In bumps with the flexible Nb leads to enable high-density wiring for the ATHENA X-IFU focal plane.

Fabrication of X-ray Microcalorimeter Focal Planes Composed of Two Distinct Pixel Types.

We are developing superconducting transition-edge sensor (TES) microcalorimeter focal planes for versatility in meeting specifications of X-ray imaging spectrometers including high count-rate, high energy resolution, and large field-of-view. In particular, a focal plane composed of two sub-arrays: one of fine-pitch, high count-rate devices and the other of slower, larger pixels with similar energy resolution, offers promise for the next generation of astrophysics instruments, such as the X-ray Integral Field Unit (X-IFU) instrument on the European Space Agency's Athena mission. We have based the sub-arrays of our current design on successful pixel designs that have been demonstrated separately. Pixels with an all gold X-ray absorber on 50 and 75 micron scales where the Mo/Au TES sits atop a thick metal heatsinking layer have shown high resolution and can accommodate high count-rates. The demonstrated larger pixels use a silicon nitride membrane for thermal isolation, thinner Au and an added bismuth layer in a 250 micron square absorber. To tune the parameters of each sub-array requires merging the fabrication processes of the two detector types. We present the fabrication process for dual production of different X-ray absorbers on the same substrate, thick Au on the small pixels and thinner Au with a Bi capping layer on the larger pixels to tune their heat capacities. The process requires multiple electroplating and etching steps, but the absorbers are defined in a single ion milling step. We demonstrate methods for integrating heatsinking of the two types of pixel into the same focal plane consistent with the requirements for each sub-array, including the limiting of thermal crosstalk. We also discuss fabrication process modifications for tuning the intrinsic transition temperature (Tc) of the bilayers for the different device types through variation of the bilayer thicknesses. The latest results on these "hybrid" arrays will be presented.

The impact of obesity on febrile urinary tract infection and renal scarring in children with vesicoureteral reflux.

INTRODUCTION: It has become clear that obesity is associated with a variety of infectious diseases, including urinary tract infection (UTI) and renal scarring. OBJECTIVE: The aim of this study was to evaluate the association between obesity and the degree of febrile UTI (fUTI) and renal scarring in children with vesicoureteral reflux (VUR), and to stratify the results into obesity subcategories. STUDY DESIGN: A total of 186 patients were diagnosed with VUR between January 2002 and December 2008. This study retrospectively reviewed the medical records of 72 children with primary VUR who had recurrent fUTI (more than twice). Overweight or obese status of the patients aged <2 years was defined using weight-for-length (WFL) measurements. For 2-5 year old children, body mass index (BMI) percentile-for-age was used. They were divided into three groups as follows; standard (<85%), overweight (85-95%), and obese (≥95%). The following clinical variables were compared: age at diagnosis of primary VUR (months), sex, VUR grade, hydronephrosis grade, presence of renal scarring, surgical treatment, and degree of inflammation during fUTI. RESULTS: In the overweight and obese groups, VUR was diagnosed at a young age (P = 0.05), the degree of renal scarring was more severe (P = 0.006), and serum white blood cell count, C-reactive protein, and erythrocyte sedimentation rate (ESR) levels were significantly higher (P < 0.001, P < 0.001, and P < 0.001, respectively). Abnormal focal dimercaptosuccinic acid (DMSA) defects were present in 25 of the 72 children (35%). Cortical defects occurred more frequently in children with obesity, and they were associated with a higher grade of reflux and serum ESR levels (P = 0.007, P = 0.042, and P = 0.021, respectively). Among these risk factors, high-grade VUR (OR = 9.93, 95% CI = 1.13-86.71), and being overweight and obese (OR = 5.26, 95% CI = 1.75-15.82) were associated with increased renal scarring. However, ESR was not associated with renal scarring (OR = 1.01, 95% CI = 0.95-1.07). DISCUSSION: The relationships between obesity and UTI are controversial. Some studies have shown positive results; however, other studies have shown opposite results. The main limitations of this study were the retrospective data collection via electronic medical records, and the small number of subjects. CONCLUSIONS: This study showed that obesity in patients with VUR has an effect on fUTI and renal scar formation. If the patients with VUR have obesity, close follow-up should be performed, and VUR patients should be started on a weight-loss program, which could reduce the number of patients with chronic kidney disease in the future.

Compensation of motion artifacts in catheter-based optical frequency domain imaging.

A novel heterodyne Doppler interferometer method for compensating motion artifacts caused by cardiac motion in intracoronary optical frequency domain imaging (OFDI) is demonstrated. To track the relative motion of a catheter with regard to the vessel, a motion tracking system is incorporated with a standard OFDI system by using wavelength division multiplexing (WDM) techniques. Without affecting the imaging beam, dual WDM monochromatic beams are utilized for tracking the relative radial and longitudinal velocities of a catheter-based fiber probe. Our results demonstrate that tracking instantaneous velocity can be used to compensate for distortion in the images due to motion artifacts, thus leading to accurate reconstruction and volumetric measurements with catheter-based imaging.

Spectrally efficient next-generation optical access network incorporating a novel CWDM uplink combiner.

A novel wavelength division multiplexed subcarrier multiplexed (WDM/SCM) broadband (1-Gb/s per user) optical access network (OAN) architecture incorporating a coarse WDM (CWDM) uplink combiner is proposed. The concept is demonstrated through theoretical and experimental validation of a 10 x1-Gb/s quadurature-phase-shift keying (QPSK) SCM optical network. Low penalty transmission is demonstrated for a proof-of-principle dual channel system with a range of 25 km. In agreement with simulation, experiments show that channel spacings of only 1 GHz are viable for Q factors of more than 18 dB. Simulations indicate that the system will operate with 40 wavelengths, each carrying 10 SCM channels at 1 Gb/s.

2,2-Dimethyl-4,5-diaryl-3(2H)furanone derivatives as selective cyclo-oxygenase-2 inhibitors.

A series of 2,2-dimethyl-5-[4-(methylsulfonyl)phenyl]-4-phenyl-3(2H)furanones was prepared and evaluated for their ability to inhibit cyclo-oxygenase-2 (COX-2).

Network-based approach to online cursive script recognition.

The idea of combining the network of HMMs and the dynamic programming-based search is highly relevant to online handwriting recognition. The word model of HMM network can be systematically constructed by concatenating letter and ligature HMM's while sharing common ones. Character recognition in such a network can be defined as the task of best aligning a given input sequence to the best path in the network. One distinguishing feature of the approach is that letter segmentation is obtained simultaneously with recognition but no extra computation is required.

Reynosin from Sassurea lappa as inhibitor on CINC-1 induction in LPS-stimulated NRK-52E cells.

An inhibitor on CINC-1 (cytokine-induced neutrophil chemoattractant-1) induction in LPS-stimulated rat kidney epithelioid NRK-52E cells was purified from the roots of Sassurea lappa Clarke, a herbal medicine used in Korean traditional prescriptions for gastric intestinal diseases by a variety of column chromatographic procedures. The inhibitor was identified as reynosin, a sesquiterpene lactone isolated and characterized previously from Ambrosia confertiflora DC., and Magnolia grandiflora L. Reynosin exhibited a dose-dependent inhibition on CINC-1 induction in LPS-stimulated NRK-52E cells, where 50% of inhibitory effect was shown at the concentration of about 1 microM.

Structure of catechol 2,3-dioxygenase gene from Alcaligenes eutrophus 335.

Catechol 2,3-dioxygenase (C23O), one of extradiol-type dioxygenases cleaving aromatic C-C bond at meta position of dihydroxylated aromatic substrates, catalyzes the conversion of catechol to 2-hydroxymuconic semialdehyde. As our ongoing study to characterize biochemical and genetic properties of the extradiol-type dioxygenases at molecular level, a C23O gene encoded in chromosomal DNA of Alcaligenes eutrophus 335, a strain degrading phenol and p-cresol, was cloned. The C23O gene was localized in an 1.4-kb PstI fragment from A. eutrophus 335, and was expressed in E. coli HB101. The C23O exhibited the highest aromatic ring-fission activity to catechol as a substrate, and its relative activity to other dihydroxylated aromatic substrates was in order of catechol >> 4-methylcatechol > 3-methylcatechol, protocatechuate, 4-chlorocatechol > 3,4-dihydroxy-phenylacetate > 2,3-dihydroxybiphenyl. Nucleotide sequence of the 1.4-kb fragment has revealed that an open reading frame (ORF) corresponding to the C23O gene was composed of 930 base pairs. A putative ribosome-binding sequence of AGGAG was found at about 10 nucleotides upstream the ORF which can encode a polypeptide of molecular weight 34 kDa consisting of 309 amino acid residues. The deduced amino acid sequence of C23O from A. eutrophus 335 exhibited the highest 59% identity with those of corresponding enzymes from Pseudomonas sp. CF600 (p VI150), P. putida HS1 (pDK1), and P. putida PpG7 (NAH7). An alignment of amino acid sequences of extradiol-type dioxygenases including C23O from A. eutrophus 335 has revealed that catalytically and structurally important amino acid residues of the enzymes were conserved during evolution.

Suppressive effects of triterpenoids on CINC-1 induction in interleukin-1beta-stimulated rat fibroblast NRK-49F cells.

CINC-1 is a member of chemokine family with chemotactic and activating properties to neutrophils. CINC-1 induction in IL-1beta-stimulated rat fibroblast NRK-49F cells was quantitated by a sensitive ELISA. CINC-1 production was increased up to 135 ng/ml from basal 2-6 ng/ml by stimulation with IL-1beta. Steroidal anti-inflammatory drugs including dexamethasone and prednisolone exhibited potent suppressive effects on IL-1beta-induced CINC-1 production. Among 39 kinds of natural triterpenoids tested, acacigenin B exhibited the highest suppressive effects with about 10 muM to be 50% of inhibition on the CINC-1 induction. The suppressive potency of acacigenin B on IL-1beta-induced CINC-1 production was about 10-fold less than that of the steroidal anti-inflammatory drugs.

Inhibitory effects of Oriental herbal medicines on IL-8 induction in lipopolysaccharide-activated rat macrophages.

Cytokine-induced neutrophil chemoattractant (CINC), a rat interleukin-8 (IL-8), was quantitated by using a sensitive ELISA. The CINC was induced up to 20 ng/ml from basal 1-2 ng/ml in lipopolysaccharide (LPS)-activated peritoneal macrophages. This CINC induction was significantly inhibited by steroidal anti-inflammatory drugs including dexamethasone, but not by non-steroidal drugs including indomethacin at all. Nine out of 59 herbal medicines which are frequently used in Korean traditional prescriptions for inflammatory diseases exhibited more than 50% of inhibition on the CINC induction by their total methanol extracts with 0.1 mg/ml as a final concentration. The active 9 total extracts were prepared from radix of Aralia continentalis, rhizoma of Cnidium officinale, rhizoma of Coptis chinensis, tuber of Fritillaria verticillata, radix of Saussurea lappa, tuber of Sparganium stoloniferum, flower of Syzygium aromaticum, semen of Trichosanthes kirilowii, and herba of Tripterygium regelii. These total extracts were sequentially fractionated with dichloromethane, ethyl acetate, butanol, and water. Among the solvent-fractionated extracts with 0.05 mg/ml as a final concentration, more than 50% of inhibition on the CINC induction was exhibited by the dichloromethane fraction of Aralia continentalis; the water fraction of Fritillaria verticillata; the dichloromethane fraction of Saussurea lappa; the dichloromethane, ethyl acetate, and butanol fractions of Syzygium aromaticum; the dichloromethane, ethyl acetate, and water fractions of Trichosanthes kirilowii; and the dichloromethane and ethyl acetate fractions of Tripterygium regelii.