Statistical Non-Parametric Mapping in Sensor Space

Michael Wagner,Reyko Tech,Manfred Fuchs,Jo¨rn Kastner,Fernando Gasca 대한의용생체공학회 2017 Biomedical Engineering Letters (BMEL) Vol.7 No.3

Establishing the significance of observed effectsis a preliminary requirement for any meaningful interpretationof clinical and experimental Electroencephalographyor Magnetoencephalography (MEG) data. We propose amethod to evaluate significance on the level of sensorswhilst retaining full temporal or spectral resolution. Inputdata are multiple realizations of sensor data. In this context,multiple realizations may be the individual epochs obtainedin an evoked-response experiment, or group study data,possibly averaged within subject and event type, or spontaneousevents such as spikes of different types. In thiscontribution, we apply Statistical non-Parametric Mapping(SnPM) to MEG sensor data. SnPM is a non-parametricpermutation or randomization test that is assumption-freeregarding distributional properties of the underlying data. The method, referred to as Maps SnPM, is demonstratedusing MEG data from an auditory mismatch negativityparadigm with one frequent and two rare stimuli and validatedby comparison with Topographic Analysis of Variance(TANOVA). The result is a time- or frequencyresolvedbreakdown of sensors that show consistentactivity within and/or differ significantly between event orspike types. TANOVA and Maps SnPM were applied tothe individual epochs obtained in an evoked-responseexperiment. The TANOVA analysis established dataplausibility and identified latencies-of-interest for furtheranalysis. Maps SnPM, in addition to the above, identifiedsensors of significantly different activity between stimulustypes.

MEG and EEG Dipole Clusters from Extended Cortical Sources

Manfred Fuchs,Jo¨rn Kastner,Reyko Tech,Michael Wagner,Fernando Gasca 대한의용생체공학회 2017 Biomedical Engineering Letters (BMEL) Vol.7 No.3

Data from magnetoencephalography (MEG) andelectroencephalography (EEG) suffer from a rather limitedsignal-to-noise-ratio (SNR) due to cortical backgroundactivities and other artifacts. In order to study the effect ofthe SNR on the size and distribution of dipole clustersreconstructed from interictal epileptic spikes, we performedsimulations using realistically shaped volumeconductor models and extended cortical sources with differentsensor configurations. Head models and corticalsurfaces were derived from an averaged magnetic resonanceimage dataset (Montreal Neurological Institute). Extended sources were simulated by spherical patches withGaussian current distributions on the folded cortical surface. Different patch sizes were used to investigate cancellationeffects from opposing walls of sulcal foldings andto estimate corresponding changes in MEG and EEG sensitivitydistributions. Finally, white noise was added to thesimulated fields and equivalent current dipole reconstructionswere performed to determine size and shape of theresulting dipole clusters. Neuronal currents are orientedperpendicular to the local cortical surface and show cancellationeffects of source components on opposing sulcalwalls. Since these mostly tangential aspects from largecortical patches cancel out, large extended sources exhibitmore radial components in the head geometry. This effecthas a larger impact on MEG data as compared to EEG,because in a spherical head model radial currents do notyield any magnetic field. Confidence volumes of singlereconstructed dipoles from simulated data at differentSNRs show a good correlation with the extension ofclusters from repeated dipole reconstructions. Size andshape of dipole clusters reconstructed from extended corticalsources do not only depend on spike and timepointselection, but also strongly on the SNR of the measuredinterictal MEG or EEG data. In a linear approximation thesize of the clusters is proportional to the inverse SNR.

Prognostic Factor Analysis of Overall Survival in Gastric Cancer from Two Phase III Studies of Second-line Ramucirumab (REGARD and RAINBOW) Using Pooled Patient Data

Charles S. Fuchs,Kei Muro,Jiri Tomasek,Eric Van Cutsem,조재용,오상철,Howard Safran,György Bodoky,Ian Chau,Yasuhiro Shimada,Salah-Eddin Al-Batran,Rodolfo Passalacqua,Atsushi Ohtsu,Michael Emig,David Ferry,Ku 대한위암학회 2017 Journal of gastric cancer Vol.17 No.2

The identified prognostic factors and the reported prognostic index may help clinical decision-making, patient stratification, and planning of future clinical studies.

Final report on CCM.M-K4: Key comparison of 1 kg stainless steel mass standards

Becerra, Luis Omar,orys, Michael,Chung, Jin Wan,Davidson, Stuart,Fuchs, Peter,Jacques, Claude,Jian, Wang,Kubarych, Zeina J,Kumar, Anil,Malengo, Andrea,Fen, Kitty,Medina, Nieves,Meury, Paul-André BUREAU INTERNATIONAL DES POIDS ET MESURES 2014 METROLOGIA -BERLIN- Vol.51 No.-

<P>This report describes a key comparison of 1 kg stainless steel mass standards, CCM.M-K4, undertaken by the Consultative Committee for Mass and Related Quantities (CCM) Working Group on the Dissemination of the kilogram (WGD-kg). The CCM.M-K4 comparison was launched during the 12th meeting of the CCM (2010). The aim of the present comparison is to verify the consistency of 1 kg stainless steel mass standards among members of the CCM.</P><P>The previous CCM 1 kg stainless steel mass standards comparison was carried out in 1995–1997 as the CCM.M-K1 comparison. The Bureau International des Poids et Mesures (BIPM) was the pilot laboratory for this key comparison. There were sixteen participants in the CCM.M-K4 comparison, all are CCM members. The comparison was structured into four petals with two stainless steel travelling mass standards per petal. The measurements and the reported results were completed in between one month and five months depending on the participants. One laboratory's results were found to be inconsistent with the other laboratories' results and one other laboratory gave a significant deviation from the key comparison reference value (KCRV). Both laboratories were contacted before preparation of the draft A report, without disclosing the details of the deviations, to allow them to check and revise their values. The fourteen other participants were in agreement with each other and degrees of equivalence have been established.</P><P>Finally, the mass values of the eight stainless steel travelling standards were determined in air by the NMIs with claimed standard uncertainties ranging from 0.007 mg to 0.021 mg. Degrees of equivalence have been established by using the generalized linear least-squares estimation (GLS) method. The result demonstrates the high quality of this comparison and that some participants are able to provide, for their mass calibration services, standard uncertainties of around ten micrograms. The good uniformity of worldwide mass dissemination since the last periodic mass verification carried out in 1992 is demonstrated by the agreement among the NMIs' results. In addition, the observed weighted mean of the NMI deviations against the BIPM is −0.0098 mg (σ = 0.0036 mg). Despite the good result obtained in this particular comparison we should, in order to have a more accurate calibration system, improve the knowledge of the ageing effects of the mass references and increase the BIPM calibration frequency of the national prototypes.</P><P>Main text.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.</P><P>The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).</P>

Use of Ledipasvir/Sofosbuvir (LDV/SOF) in Patients with Advanced Chronic Kidney Disease (eGFR ≤30ml/min): A Case Series

( Meghan E. Sise ),( Naim Alkhouri ),( Brian Borg ),( Sooji Lee ),( Thomas Mcquaid ),( Joseph Llewellyn ),( Macky Natha ),( Shampa De-oertel ),( Diana M. Brainard ),( Marc Carp ),( Michael Fuchs ),( H 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1

Aims: Little is known about the safety and efficacy of LDV/SOF in patients with advanced chronic kidney disease (CKD) with eGFR ≤ 30 ml/min or on hemodialysis. Yet, off-label use of LDV/SOF in this population occurs. Methods: Providers proactively reporting such off-label use to Gilead Sciences were asked to submit de-identified case reports. Demographics, clinical characteristics at baseline, during, and after LDV/SOF treatment, and adverse events were collected. Summary statistics and paired sample t-tests are presented. Results: Twenty-one case summaries were submitted. Median Age was 59 (range 26-71). Eleven patients (52%) were black, 20 had genotype 1 (13-1a, 4-1b) and one patient had genotype 3. Median pretreatment viral load was 1,680,000 IU (range 133,000-37,200,000 IU). Twelve patients (56%) were on hemodialysis and 9 had CKD Stage 4 (eGFR 15-29 ml/min), 13 (62%) had cirrhosis, 11 (50%) had diabetes, 5 had history of organ transplantation (4 kidney, 1 liver). All patients received full dose LDV/SOF for 12 weeks with one patient also receiving 200 mg Ribavirin every other day in combination. Eight adverse events were reported; 2 patients (10%) with anemia, 1 case of insomnia, nausea/vomiting, headache, and chest pain (5%) each. Of the 9 patients with CKD stage 4, 2 experienced an increase in eGFR and 5 a decrease in eGFR post treatment. All 21 patients achieved SVR 12 (100%). No patient discontinued treatment due to an adverse event. Conclusions: In this small case series describing the use of ledipasvir/sofosbuvir in Patients with Advanced Chronic Kidney Disease: 62% had cirrhosis, 52% had diabetes mellitus, and 57% were on hemodialysis. All 21 patients achieved SVR12 including 12 patients on hemodialysis. LDV/SOF was relatively well tolerated and there were no treatment discontinuations. Most patients had stable renal function before and after treatment with LDV/SOF.