bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identifying Cochlear Implant Channels With Relatively Poor Electrode-Neuron Interfaces Using the Electrically Evoked Compound Action Potential
Authors: Jahn Kelly N. , Arenberg Julie G. 
Published: January 2020

Objectives:The primary objective of this study was to quantify local (within ear) and global (between ear) variation in the cochlear implant (CI) electrode-neuron interface (ENI) using the electrically evoked compound action potential (ECAP). We tested the hypothesis that, within an ear, ECAP measures can be used to identify channels with presumed good and poor ENIs, which may be influenced by a combination of spiral ganglion neuron (SGN) density, electrode position, and cochlear resistivity. We also hypothesized that ECAP responses would reflect age-related differences in the global quality of the ENI between younger and older listeners who theoretically differ in SGN density.Design:Data were obtained from 18 implanted ears (13 individuals) with Advanced Bionics HiRes 90K devices. Six participants (8 ears) were adolescents or young adults (age range: 14–32 years), and 7 participants (10 ears) were older adults (age range: 54–88 years). In each ear, single-channel auditory detection thresholds were measured on channels 2 through 15 in response to a spatially focused electrode configuration (steered quadrupolar; focusing coefficient = 0.9). ECAP amplitudes, amplitude growth function (AGF) slopes, and thresholds were assessed on a subset of channels in each ear in response to three interphase gaps (0, 7, and 30 µs). ECAP peak amplitudes were assessed on all channels between 2 and 15. AGFs and ECAP thresholds were measured on the two nonadjacent channels with the lowest and highest focused behavioral thresholds in each ear. ECAP responses were compared across low- and high-threshold channels and between younger and older CI listeners.Results:Channels that were estimated to interface poorly with the auditory nerve (i.e., high-focused-threshold channels) had steeper ECAP AGF slopes, smaller dynamic ranges, and higher ECAP thresholds than channels with low focused thresholds. Younger listeners had steeper ECAP AGF slopes and larger ECAP peak amplitudes than older listeners. Moreover, younger listeners showed greater interphase gap sensitivity for ECAP amplitude than older listeners.Conclusions:ECAP responses may be used to quantify both local (within ear) and global (between ear) variation in the quality of the ENI. Results of this study support future investigation into the use of ECAP responses in site-selection CI programming strategies. The present results also support a growing body of evidence suggesting that adolescents and young adults with CIs may have denser populations of functional SGNs relative to older adults. Potential differences in global SGN integrity between younger and older listeners warrant investigation of optimal CI programming interventions based on their divergent hearing histories.
Sagittal Plane Residual Deformity in Pediatric Type II Supracondylar Humerus Fractures
Authors: Silva Mauricio , Day Matthew J. , Aceves-Martin Bianka , Ebramzadeh Edward 
Published: January 2020

Introduction:
The incidence of residual deformity in the sagittal plane of the humerus (RDSPH) after nonoperative management of type II supracondylar humerus fractures (SCHFs), and the effects of such deformity on the overall arc of motion (AOM) of the elbow, are unknown. Our purpose was to analyze data collected prospectively on a large cohort of type II SCHF’s to establish the incidence and extent of RDSPH, and the effects of the deformity on the elbow function, to further support our previously published recommendations on the treatment of type II SCHF.

Methods:
The clinical data and radiographs of 1107 pediatric type II SCHFs enrolled in a prospective registry, and followed for a minimum of 8 weeks, were retrospectively reviewed. The radiographs obtained during the latest follow-up appointment were examined for the presence of RDSPH, as demonstrated by the anterior humeral line falling anterior or posterior relative to the center of the capitellum. The amount of RDSPH in the sagittal plane was then calculated. We compared the treatment outcome of elbows with and without RDSPH by assessing the patients’ AOM, the arc of flexion (AOF), and relative arcs of motion (R-AOM) and relative arcs of flexion (R-AOF) (as compared with the unaffected, contralateral elbow).

Results:
Overall, 799 (72.2%) fractures were treated nonsurgically, and 308 (27.8%) fractures were treated surgically. The overall incidence of RDSPH was 10.2%. None of the fractures managed operatively demonstrated residual deformity. The RDSPH was classified as mild in 35 fractures (3.2%), moderate in 64 fractures (5.7%) and severe in 14 fractures (1.3%). Therefore, the incidence of RDSPH in fractures treated nonoperatively was 14.1%. In fractures treated nonoperatively, the difference in AOM between those without (n=686) and with (n=113) RDSPH was <4 degrees (149.1 vs. 145.8 degrees, P=0.02). Those with and without RDSPH had a clinically similar AOF, with a mean difference of<4 degrees (134.5 vs. 137.9 degrees, P<0.0001). The differences in R-AOM and R-AOF between those with and without RDSPH were minimal (97.3% vs. 95.6% and 96.6% vs. 95.3%, respectively). A satisfactory outcome, defined as an R-AOM of at least 85% when compared with the unaffected, contralateral side at the latest follow-up, was achieved in 91% of fractures with RDSPH, and 93% of fractures without RDSPH.

Discussion and Conclusion:
The incidence of RDSPH in type II SCHF treated nonoperatively was 14%. In our cohort, nearly 99% of all RDSPH were mild to moderate. On the basis of the data presented in the current study, nonsurgical treatment of type II SCHF can provide a satisfactory recovery of AOM, AOF, R-AOM, and R-AOF, and a high rate of satisfactory outcomes, even in the presence of RDSPH.
Does Pedicle Screw Fixation Assisted by O-Arm Navigation Perform Better Than Fluoroscopy-guided Technique in Thoracolumbar Fractures in Percutaneous Surgery?
Authors: Lu Jianhua , Chen Weikai , Liu Hao , Yang Huilin , Liu Tao 
Published: January 2020

Study Design:
A retrospective cohort study.

Objective:
To evaluate the effect of O-arm navigation in percutaneous surgeries for thoracolumbar fracture in comparison to the use of conventional fluoroscopic technique.

Summary of Background Data:
O-arm navigation is a progressive surgical tool, with extensive research papers reporting its effects. Whereas, there were not many papers describing its accuracy and facet impingement rate when compared with fluoroscopy-guided technique in percutaneous surgeries, especially at varying fracture levels.

Materials and Methods:
We conducted a retrospective comparative study of 97 consecutive patients of single-level neurological intact thoracolumbar fractures from November 2015 to October 2017 and they were all treated with percutaneous pedicle screw implantation. Screws were classified as 4 grades of perforations and 3 grades of facet joint violation. The association between variables such as anatomic perforation, functional perforation, and facet impingement were investigated by χ2 test, Fisher exact test or t test. A P-value of <0.05 was considered statistically significant.

Results:
A total of 573 pedicle screws were implanted and graded. The overall anatomic perforation rate and functional perforation rate were lower in the O-arm group compared with the fluoroscopy group (8.3% vs. 15.0%, P=0.013, 1.1% vs. 4.2%, P=0.024). At fracture level, the rate of grade 2 perforation of the O-arm group was lower than that of the fluoroscopy group (0% vs. 6.1%, P=0.033). Furthermore, the O-arm group obviously reduced the facet impingement rate both at all levels and at fracture levels (P=0.002; 0.02).

Conclusions:
In percutaneous pedicle screw placement for neurological intact thoracolumbar fracture, the introduction of O-arm navigation improved accuracy, reduced functional perforations, and minimized serious perforations compared with conventional fluoroscopic technique. It also decreased facet joint violation observably and helped to prevent development of adjacent segment degeneration.
Differential Expression of Cancer Testis Antigens on Lentigo Maligna and Lentigo Maligna Melanoma
Authors: Tio Darryl , Willemsen Marcella , Krebbers Gabrielle , Kasiem Fazira R. , Hoekzema Rick , van Doorn Remco , Bekkenk Marcel W. , Luiten Rosalie M. 
Published: January 2020

Abstract:
The cancer/testis antigens (CTA) are a group of antigens expressed on germ cells of healthy testis and malignant tumors. We studied whether CTA are present on lentigo maligna (LM) and LM melanoma (LMM) samples. Immunohistochemical expression of a panel of CTA (MAGE-A1, A2- A3, NY-ESO-1, PRAME, SSX-2, and a MAGE-A antibody reactive with -A1, -A2, -A3, -A4, -A6, -A10, and -A12) was investigated in formalin-fixed paraffin-embedded samples from LMM (n = 20), LM (n = 8), chronically sun-exposed skin (n = 7), and healthy skin (n = 7). In 4 LMM lesions, the MAGE-A marker was positive. Another 3 LMM lesions were positive for MAGE-A1, MAGE-A2, and MAGE-A3. PRAME was positive in 18/20 LMM and 6/8 LM. We did not find expression of MAGE, NY-ESO-1, or SSX-2 in LM, thereby excluding these CTA as diagnostic markers to discern malignant melanocytes in LM from normal melanocytes. LMM did express MAGE, NY-ESO-1, and SSX-2. If a biopsy from a lesion suspect for LM shows positivity for MAGE, NY-ESO-1, and SSX-2, the lesion may actually be LMM. In contrast, PRAME expression was found in LM at low levels and in LMM at much higher levels, and absent in normal melanocytes. PRAME can potentially be used to discern normal melanocytes from malignant melanocytes.
Therapeutic Drug Monitoring of Asparaginase: Intra-individual Variability and Predictivity in Children With Acute Lymphoblastic Leukemia Treated With PEG-Asparaginase in the AIEOP-BFM Acute Lymphoblastic Leukemia 2009 Study
Authors: Würthwein Gudrun , Lanvers-Kaminsky Claudia , Gerss Joachim , Möricke Anja , Zimmermann Martin , Stary Jan , Smisek Petr , Attarbaschi Andishe , Nath Christa , Zucchetti Massimo , Rizzari Carmelo , Schrappe Martin , Boos Joachim ,   on behalf of the AIEOP-BFM ALL 2009 Asparaginase Working Party
Published: January 2020

Background:
Therapeutic drug monitoring (TDM) can identify patients with subtherapeutic asparaginase (ASNase) activity [silent inactivation (SI)] and prospectively guide therapeutic adaptation. However, limited intra-individual variability is a precondition for targeted dosing and the diagnosis of SI.

Methods:
In the AIEOP-BFM acute lymphoblastic leukemia (ALL) 2009 trial, 2771 children with ALL were included and underwent ASNase-TDM in a central laboratory in Münster. Two biweekly administrations of pegylated ASNase during induction and a third dose during reinduction or the high-risk block, which was administered several weeks later, were monitored. We calculated (1) the incidence of SI; and (2) the predictivity of SI for SI after the subsequent administration. ASNase activities monitored during induction were categorized into percentiles at the respective sampling time points. These percentiles were used to calculate the intra-individual range of percentiles as a surrogate for intrapatient variability and to evaluate the predictivity of ASNase activity for the subsequent administration.

Results:
The overall incidence of SI was low (4.9%). The positive predictive value of SI identified by one sample was ≤21%. Confirmation of SI by a second sample indicated a high positive predictive value of 100% for biweekly administrations, but not for administration more than 17 weeks later. Sampling and/or documentation errors were risks for misdiagnosis of SI. High intra-individual variability in ASNase activities, with ranges of percentiles over more than 2 quartiles and low predictivity, was observed in approximately 25% of the patients. These patients were likely to fail dose individualization based on TDM data.

Conclusions:
To use TDM as a basis for clinical decisions, standardized clinical procedures are required and high intra-individual variability should be taken into account. Details of the treatment are available in the European Clinical Trials Database at https://www.clinicaltrialsregister.eu/ctr-search/trial/2007-004270-43/DE.
High Submaximal Exercise Heart Rate Impacts Exercise Intolerance in the Postural Orthostatic Tachycardia Syndrome
Authors: Van Iterson Erik H. , Laffin Luke J. , Mayuga Kenneth A. , Hutt Centeno Erika , Ahmed Taha , Cho Leslie , Ahmed Haitham M. 
Published: January 2020

Purpose:
Exercise intolerance is a hallmark of the postural orthostatic tachycardia syndrome (POTS). However, no data are available on the implications of an exaggerated submaximal heart rate (HR) on exercise intolerance in patients. We investigated whether exaggerated HR responses occurring early on during incremental stress testing relate with increased odds of POTS and exercise intolerance.

Methods:
Clinical characteristics and stress test HRs were compared between adults with POTS achieving ≥85% predicted metabolic equivalents (METs) (EX-TL, n = 101; body mass index [BMI] 24 ± 5 kg·m−2; 95% women) or <85% (EX-INTL, n = 71; BMI 28 ± 7 kg·m−2; 79% women) and sedentary controls (n = 30; BMI 36 ± 3 kg·m−2; 87% women). Multivariate logistic regressions were performed to estimate ORs and the probability of POTS and exercise intolerance associated with exercise HRs.

Results:
Exercise tolerance was increased in EX-TL, but not in EX-INTL (10.0 ± 1.3 and 8.3 ± 1.5 METs vs 8.0 ± 1.6 METs, respectively) versus controls. Absolute peak HR was increased in EX-TL and EX-INTL versus controls (P < .01), whereas percent predicted did not differ. Exercise within the first-to-second stress stages was performed at exaggerated HRs (122 ± 17 bpm vs 103 ± 15 and 113 ± 15 bpm, P < .001) and percent HR reserve in EX-INTL versus controls and EX-TL (49% ± 12% vs 34% ± 11% and 41% ± 11%, P < .001), respectively. In multivariate analyses, peak HR was not significant, whereas increased submaximal HR (either variable) was associated with increased odds of EX-TL or EX-INTL. Lastly, odds of EX-INTL increased as METs decreased, whereas METs was not a predictor of EX-TL.

Conclusions:
An exaggerated submaximal exercise HR is predictive of POTS and exercise intolerance, and this chronotropic phenotype is exacerbated in patients achieving <85% predicted METs.
Neutron and Photon Dose Rates in a D-T Neutron Generator Facility: MCNP Simulations and Experiments
Authors: Xu Xu , Yi Chang , Wanyue Tang , Yuanming Sun , Jingbin Lu , Yumin Liu , Long Zhao , Jiaxi Liu , Xiaoyi Li 
Published: January 2020

Abstract
The deuterium-tritium neutron generator is a common neutron source for fast neutron activation analysis. The 14.1 MeV neutrons emitted from a deuterium-tritium neutron generator are difficult to shield due to their strong penetrability and the induced secondary gamma rays in the shield. A rough calculation based on attenuation factors shows that when 14.1 MeV neutrons with a yield of 1 × 108 ns−1 penetrate the designed shielding layers, which consist of a 0.5-m-thick concrete layer and a 0.5-m-thick water layer, the neutron ambient dose equivalent rate is 2.48 μSv h−1. A geometric model of a neutron shielding room is constructed based on the calculation. Monte Carlo simulations indicate that the highest neutron ambient dose equivalent rate outside the neutron shielding room is 0.73 μSv h−1, and the neutron ambient dose equivalent rate at the detector position in the shielding room is 2.12 μSv h−1. The experimental results show that the highest neutron ambient dose equivalent rate outside the neutron shielding room is 1.43 μSv h−1, and the neutron ambient dose equivalent rate at the detector position inside the shielding corridor is 2.74 μSv h−1. Comparative investigations show that the experimental results are basically consistent with the results of the Monte Carlo simulations, except for some positions with large proportions of fast neutrons where it is too difficult for the neutron dose equivalent meter to provide reliable values. Moreover, the radiation dose rate outside the designed shielding room is lower than the occupational exposure dose limit, which is in line with the design expectations. Finally, the gamma spectrum at the position of the gamma detectors is measured by a high-purity germanium detector. The analyzed results show that many secondary gamma rays are generated by the interaction of neutrons with the shield materials and detector probe crystals, and some gamma rays are produced from natural background radionuclides such as 40K, 208Tl, 212Bi, 214Bi, 212Pb, 214Pb, and 228Ac.
MP3 Plus: A Modified Micropulse Transscleral Cyclophototherapy Technique for the Treatment of Refractory Glaucoma
Authors: Wong Kirsten Yue Ting , Aquino Cecilia Maria , Macasaet Anne Marie , Suwandono Maya Ekakristiani , Chew Paul Tec Kuan , Koh Victor Teck Chang 
Published: January 2020

Précis:
In advanced refractory glaucoma which has failed prior MP3 laser, MP3 Plus is effective in reducing intraocular pressure (IOP) without significant complications. It is also useful as a temporizing procedure before incisional surgery.

Purpose:
To evaluate the efficacy and safety of MP3 Plus, a novel technique using modified micropulse transscleral cyclophototherapy (MPTCP) in eyes with refractory glaucoma or failed MPTCP treatment.

Methods:
This is a retrospective interventional case series. In total, 32 consecutive eyes from 29 patients with uncontrolled IOPs who had previous MPTCP or refractory glaucoma underwent MP3 Plus, a modified MPTCP where additional discrete pulses are applied. The main outcome measurement was IOP at 1, 3, 6, and 12 months postprocedure, with success defined as a 20% reduction in baseline IOP, an IOP of 25 mmHg or less, and no need for further reoperation. We collected and analyzed visual acuity, number of glaucoma medications, and complications.

Results:
The patients had an average of 1.4±0.9 glaucoma procedures before treatment, where 87.5% underwent one or more previous MPTCP with suboptimal response. Of the eyes presenting for follow-up, 51.6% (n=31), 37.0% (n=27), 35.7% (n=28), and 25.9% (n=27) achieved the primary outcome at 1, 3, 6, and 12 months, respectively. Baseline IOP was 33.7±11.6 mmHg (n=32 eyes) and posttreatment IOP at 1, 3, 6, and 12 months were 21.0±9.0 mmHg (n=31; P<0.0001), 26.2±10.8 mmHg (n=25; P<0.0001), 23.2±9.4 mmHg (n=20; P<0.05), and 24.6±9.8 mmHg (n=16; P<0.001), respectively. There was a reduction in glaucoma medications from 3.4±0.8 preoperatively to 2.8±1.2 (n=16; P<0.05) at 12 months. There were no cases of prolonged inflammation or hypotony.

Conclusions:
MP3 Plus is effective and safe in lowering IOP in eyes with refractory glaucoma after previous failed MPTCP.
Solitary Free-Floating Iris Cyst Associated With Bilateral Pigment Dispersion Syndrome: Report of a Case
Authors: Bruttini Carlo , Vulpetti Andrea , Riva Ivano , Katsanos Andreas , Oddone Francesco , Quaranta Luciano 
Published: January 2020

Case Report:
A 27-year-old white man with a 5-year history of pigment dispersion syndrome presented for evaluation. His past ocular history was significant for bilateral intraocular pressure elevation that had required intraocular pressure -lowering medication (beta-blocker-prostaglandin analogue fixed combination). On ophthalmic examination, the visual acuity was 20/20 without correction in both eyes. Anterior chamber slit-lamp examination revealed a pigmented round mass with modest transillumination at 6-o’clock position of the right eye. When asked, the patient reported that he had first noticed a shadow in his right eye during childhood when he was flexing his neck and keeping a face-down position for a few seconds. During a head-flexing test, the mass freely floated in the anterior chamber. When the patient extended the neck, the round mass could be seen in front of the pupil. After a few moments, the mass would slowly fall to the iridocorneal angle at the 6-o’clock position. Ultrasound biomicroscopy and anterior-segment optical coherence tomography confirmed that the lesion was a pigmented cyst without internal reflectivity. Specular microscopy examinations, performed to exclude cyst-induced corneal endothelium compromise, revealed a cell-density of ~3000 cells/mm2 in both eyes. Gonioscopy showed an open angle with trabecular pigmentation and funduscopy a cup-to-disc ratio of 0.5 bilaterally. Visual fields and optical coherence tomography tests were within normal limits.

Conclusions:
The etiology of free-floating iris cysts is unclear, but it is generally agreed that these masses are usually dislodged pigment epithelial cysts. This is the first report of a unilateral free-floating iris cyst associated with bilateral pigment dispersion syndrome.
Posterior chamber phakic intraocular lens for the correction of presbyopia in highly myopic patients
Authors: Stodulka Pavel , Slovak Martin , Sramka Martin , Polisensky Jaroslav , Liska Karel 
Published: January 2020

Purpose:
To report the initial experience with a new presbyopic phakic intraocular lens (pIOL) in the correction of high myopia and presbyopia.

Setting:
Gemini Eye Clinic, Zlin, Czech Republic.

Design:
Prospective cohort study.

Methods:
Presbyopic eyes with moderate to high myopia were implanted with a presbyopic posterior chamber pIOL (IPCL). The visual acuities at near and distance, endothelial cell density, and ocular condition were examined 1 week, 3 months, 1 year and 2 years postoperatively.

Results:
The mean uncorrected distance visual acuity improved significantly from 1.25 logarithm of the minimum angle of resolution (logMAR) (1.15 to 1.35 95% confidence interval [CI]) to 0.11 logMAR (95% CI, 0.03 to 0.17) (P < .0001). No eye lost 1 or more lines of corrected distance visual acuity. The mean distance refraction improved significantly from −6.9 diopters (D) (range −8.6 to −5.3 D) preoperatively to −0.35 D (range −0.55 to −0.15 D, P < .0001) with less than −0.5 D residual refraction in 11 of 17 eyes. Fifteen of 17 eyes had improved uncorrected near visual acuity to J1 (Jaeger chart) at the 2-year follow-up. The near addition at the 2-year follow-up decreased from preoperatively +1.26 D (range 0.19 to 2.34 D) to +0.39 D (range 0.18 to 0.60 D). The mean endothelial cell density was reduced from 2552 cells/mm2 (range 2421 to 2682 cells/mm2) to 2299 cells/mm2 (range 2108 to 2490 cells/mm2) after 2 years. All patients were subjectively satisfied with the outcomes.

Conclusions:
The new pIOL provided good visual outcomes in near and far distances in an initial case series of patients.