bluuebunny/crossref_metadata_2025 huggingface dataset:
Complete Reoperation in Orthognathic Surgery
Authors: Wu Robin T. , Wilson Alexander T. , Gary Cyril S. , Steinbacher Derek M.
Published: April 2019

Background:

Complete reoperation is defined as undergoing reoperative/repeated jaw osteotomies, in a patient who previously underwent orthognathic surgery. The purpose of this study is to (1) describe jaw positions at three time-points (before primary and before and after reoperative surgery), (2) investigate factors necessitating reoperation, and (3) outline the technical challenges.

Methods:

Repeated orthognathic surgery cases >1-year out were included. Demographic, radiologic, and perioperative data were compiled. Repeated osteotomies (Le-Fort and/or bilateral split sagittal osteotomy, with or without genioplasty), were compared to their respective primary procedures. Statistical analysis was performed using t tests and z-scores.

Results:

Fifteen patients were included (28.1 years; 71 percent female). Reoperative/repeated surgery was most often needed to address iatrogenic bony malposition and asymmetry. Relapse was a less common indication. Time between reoperative and primary surgery was 14 months. Sagittal discrepancies (p = 0.029) were the most frequent reason for primary orthognathic surgery (e.g., mandibular hypoplasia (p = 0.023). Reoperative/repeated orthognathic was performed for asymmetry (p = 0.014). Repeated procedures used more 3-dimensional planning (p < 0.001), required all three osteotomies (p = 0.034), had longer operative times (p = 0.078), and all required hardware removal (p < 0.001). Anatomical outcomes were good with 100% patient satisfaction at long-term follow-up.

Conclusions:

Reoperative/repeated orthognathic surgery is challenging and underreported in the literature. Whereas primary orthognathic typically addressed sagittal discrepancies, reoperative/repeated osteotomies were needed to correct iatrogenic bone malposition and asymmetries. Challenges include: re-planning, scar burden, need to remove integrated hardware, and repeated osteotomy/fixation. Despite these difficulties, outcomes and patient acceptance were good.

CLINICAL QUESTION/LEVEL OF EVIDENCE:

Therapeutic, IV.
Cryopreservation and Transplantation of Vascularized Composite Transplants: Unique Challenges and Opportunities
Authors: Shani Nir , Friedman Or , Arav Amir , Natan Yehudit , Gur Eyal
Published: April 2019

Vascularized composite allotransplantation is the ultimate reconstructive tool when no other means of reconstruction are available. Despite its immense potential, the applicability of vascularized composite allotransplantation is hampered by high rejection rates and the requirement for high doses of immunosuppressive drugs that are associated with severe adverse effects and death. Because this is a non–life-saving procedure, widespread use of vascularized composite allotransplantation demands methods that will allow the reduction or elimination of immunosuppressive therapy. Efficient methods for the cryopreservation of biological cells and tissues have been sought for decades. The primary challenge in the preservation of viable tissue in a frozen state is the formation of intracellular and extracellular ice crystals during both freezing and thawing, which cause irreversible damage to the tissue. Recent proof-of-concept transplantations of a complete cryopreserved and thawed hindlimb in a rat model have demonstrated the potential of such methods. In the current review, the authors discuss how limb cryopreservation can attenuate or eliminate allograft rejection by either enabling better human leukocyte antigen matching or by adaptation of clinical tolerance protocols such as mixed chimerism induction. Also, the authors discuss the possible advantages of cryopreservation in autologous tissue salvage and cryopreservation following trauma. Clinical-grade cryopreservation may revolutionize the field of reconstruction, organ banking, and complex traumatic limb injury management.
Fat Grafting in Managing Craniofacial Deformities
Authors: Denadai Rafael , Raposo-Amaral Cesar Augusto , Raposo-Amaral Cassio Eduardo
Published: April 2019

Background:

The successful correction of craniofacial contour deformities remains a major challenge in plastic surgery. This article reviews important concepts and strategies for craniofacial fat grafting and presents a SOBRAPAR Hospital algorithm focused on achieving craniofacial contour symmetry as early as possible without compromising function.

Methods:

Principle-based methods (i.e., anatomical facial fat compartments, fluid accommodation model, multistage site-specific craniofacial fat grafting, and structural fat-grafting technique) were itemized into an algorithm to aid in planning and selecting the best surgical approach (i.e., bone and/or soft tissue procedures) in order to obtain craniofacial contour symmetry.

Results:

The treatment plan and choice of surgical technique implemented to address bone and/or or soft tissue deformities were determined by specific diagnosis, patient age at presentation, and functional status. Bony reconstruction in skeletally immature patients is reserved solely for those patients with functional issues.

Conclusion:

By adopting principle-based methods and fat compartment theory, we are able to achieve craniofacial contour symmetry and aesthetically pleasing outcomes without compromising function.
Long-Term Outcomes of Brachial Plexus Reconstruction with Sural Nerve Autograft for Brachial Plexus Birth Injury
Authors: Manske M. Claire , Bauer Andrea S. , Hentz Vincent R. , James Michelle A.
Published: April 2019

Background:

Infants with brachial plexus birth injury who do not recover motor function spontaneously in a timely manner are candidates for brachial plexus reconstruction with nerve autograft. Outcomes of this intervention are incompletely understood. The authors present the long-term outcomes of brachial plexus reconstruction with sural nerve autograft in infants with brachial plexus birth injury.

Methods:

The authors retrospectively reviewed all infants with brachial plexus birth injury who underwent brachial plexus reconstruction with sural nerve autograft between 1992 and 2014 with a minimum 2-year follow-up. The authors used Active Movement Scale scores to determine the presence and timing of shoulder, elbow, and wrist recovery. They assessed recovery of hand function in infants with global brachial plexus birth injury with the Raimondi scale. The number and type of secondary reconstructive procedures were identified.

Results:

Forty-three infants who underwent brachial plexus reconstruction at age 7 ± 2 months old were followed for 7 ± 5 years. Most infants recovered antigravity elbow flexion (91 percent) and shoulder abduction (67 percent), but fewer recovered antigravity shoulder external rotation (19 percent) and wrist extension (37 percent). Mean postoperative times until observed antigravity motor strength (Active Movement Scale score >5) at the shoulder, elbow, and wrist were all greater than 12 months; evidence of initial motor recovery (Active Movement Scale score >2) was observed earlier. The mean Raimondi score in infants with global brachial plexus birth injury was 2.2 (range, 0 to 5) at final follow-up. Thirty-three children underwent 2 ± 1.2 secondary reconstructive procedures.

Conclusions:

Brachial plexus reconstruction with sural nerve autograft reliably results in recovery of shoulder abduction and elbow flexion, but recovery of shoulder external rotation and wrist extension is less predictable, and recovery often takes more than 1 year. Secondary procedures are often performed to optimize function.

CLINICAL QUESTION/LEVEL OF EVIDENCE:

Therapeutic, IV.
Unconventional Perfusion Flaps in the Experimental Setting: A Systematic Review and Meta-Analysis
Authors: Casal Diogo , Tanganho David , Cunha Teresa , Mota-Silva Eduarda , Iria Inês , Pais Diogo , Videira Paula , Videira-Castro José , Goyri-O’Neill João
Published: April 2019

Background:

Unconventional perfusion flaps offer multiple potential advantages compared with traditional flaps. Although there are numerous experimental articles on unconventional perfusion flaps, the multiple animal species involved, the myriad vascular constructions used, and the frequently conflicting data reported make synthesis of this information challenging. The main aim of this study was to perform a systematic review and meta-analysis of the literature on the experimental use of unconventional perfusion flaps, to identify the best experimental models proposed and to estimate their global survival rate.

Methods:

The authors performed a systematic review and meta-analysis of all articles written in English, French, Italian, Spanish, and Portuguese on the experimental use of unconventional perfusion flaps and indexed to PubMed from 1981 until February 1, 2017.

Results:

A total of 68 studies were found, corresponding to 86 optimized experimental models and 1073 unconventional perfusion flaps. The overall unconventional perfusion flap survival rate was 90.8 percent (95 percent CI, 86.9 to 93.6 percent; p < 0.001). The estimated proportion of experimental unconventional perfusion flaps presenting complete survival or nearly complete survival was 74.4 percent (95 percent CI, 62.1 to 83.7 percent; p < 0.001). The most commonly reported animal species in the literature were the rabbit (57.1 percent), the rat (26.4 percent), and the dog (14.3 percent). No significant differences were found in survival rates among these species, or among the diverse vascular patterns used.

Conclusion:

These data do not differ significantly from those reported regarding the use of unconventional perfusion flaps in human medicine, suggesting that rabbit, rat, and canine experimental unconventional perfusion flap models may adequately mimic the clinical application of unconventional perfusion flaps.
Streamlining the Assessment of Patient-Reported Outcomes in Weight Loss and Body Contouring Patients: Applying Computerized Adaptive Testing to the BODY-Q
Authors: Geerards Daan , Klassen Anne F. , Hoogbergen Maarten M. , van der Hulst René R.W.J. , van den Berg Lisa , Pusic Andrea L. , Gibbons Chris J.
Published: April 2019

Background:

The BODY-Q is a widely used patient-reported outcome measure of surgical outcomes in weight loss and body contouring patients. Reducing the length of the BODY-Q assessment could overcome implementation barriers in busy clinics. A shorter BODY-Q could be achieved by using computerized adaptive testing, a method to shorten and tailor assessments while maintaining reliability and accuracy. In this study, the authors apply computerized adaptive testing to the BODY-Q and assess computerized adaptive testing performance in terms of item reduction and accuracy.

Methods:

Parameters describing the psychometric properties of 138 BODY-Q items (i.e., questions) were derived from the original validation sample (n = 734). The 138 items are arranged into 18 scales reflecting Appearance, Quality of Life, and Experience of Care domains. The authors simulated 1000 administrations of the computerized adaptive testing until a stopping rule, reflecting assessment accuracy of standard error less than 0.55, was met. The authors describe the reduction of assessment length in terms of the mean and range of items administered. The authors assessed accuracy by determining correlation between full test and computerized adaptive testing scores.

Results:

The authors ran 54 simulations. Mean item reduction was 36.9 percent (51 items; range, 48 to 138 items). Highest item reduction was achieved for the Experience of Care domain (56.2 percent, 22.5 items). Correlation between full test scores and the BODY-Q computerized adaptive test scores averaged 0.99.

Conclusions:

Substantial item reduction is possible by using BODY-Q computerized adaptive testing. Reduced assessment length using BODY-Q computerized adaptive testing could reduce patient burden while preserving the accuracy of clinical patient-reported outcomes for patients undergoing weight loss and body contouring operations.
Five-Year Experience with Fifth-to-Seventh Nerve Transfer for Smile
Authors: Banks Caroline A. , Jowett Nate , Iacolucci Carlo , Heiser Alyssa , Hadlock Tessa A.
Published: April 2019

Background:

Masseteric- or deep temporal–to-facial nerve transfer (five-to-seven nerve transfer) is increasingly used in facial reanimation; however, the indications and clinical variables affecting outcomes for five-to-seven nerve transfer have not been defined. The authors describe their early experience with five-to-seven nerve transfer, reporting function and patient-reported outcomes, to identify potential parameters that are predictive of outcome.

Methods:

The authors conducted a retrospective chart review of all patients who underwent five-to-seven nerve transfer for smile reanimation from 2012 to 2017. Age, sex, cause of facial paralysis, onset and duration of paralysis, history of adjuvant chemotherapy and/or radiation therapy, donor nerve used, adjunctive procedures, and final excursion were recorded. Standard photographs and videos, and data regarding clinical facial nerve function and patient-reported quality of life, were obtained preoperatively and postoperatively.

Results:

Sixty patients were identified. Forty-seven had flaccid facial paralysis and 13 had postparalysis facial palsy. Among flaccid facial paralysis patients, masseteric nerve transfer was successful in 30 patients (88 percent) and deep temporal nerve transfer was successful in three cases (60 percent). Among postparalysis facial palsy patients, five-to-seven nerve transfer was successful in two patients (20 percent). Average quality-of-life scores improved significantly from preoperatively (46) to postoperatively (59) among flaccid facial paralysis patients with successful five-to-seven nerve transfer.

Conclusions:

Five-to-seven nerve transfer is a viable option in facial reanimation. Shorter denervation times and preoperative flaccidity are favorable predictors of outcome. Five-to-seven nerve transfer as an adjunct to primary repair appears highly effective for enhancing smile function. Five-to-seven nerve transfer results are not reliable in patients with postparalysis facial palsy.

CLINICAL QUESTION/LEVEL OF EVIDENCE:

Therapeutic, IV.
Prophylaxis in High-Risk Patients With eGFR < 30 mL/min/1.73 m2
Authors: Nijssen Estelle C. , Nelemans Patty J. , Rennenberg Roger J. , Theunissen Ralph A. , van Ommen Vincent , Wildberger Joachim E.
Published: April 2019

Objectives

Clinical guidelines recommend prophylactic intravenous fluids for patients with estimated glomerular filtration rate (eGFR) less than 30 mL/min/1.73 m2 to prevent adverse postcontrast outcomes. These patients represent a small minority of the population receiving intravascular iodinated contrast material, and data are not readily available. The current study aim is to gain insight into positive and negative effects of prophylaxis by comparing postcontrast outcomes in high-risk patients who did and did not receive prophylaxis.

Materials and Methods

Observational data were gathered over 4 years. Inclusion criteria were age 18 years or older, eGFR less than 30 mL/min/1.73 m2, and elective intravascular iodinated contrast administration. Exclusion criteria were dialysis and nonstandard periprocedural prophylaxis. Primary outcome was postcontrast acute kidney injury (>25% or >44 μmol/L serum creatinine increase within 2–5 days). Secondary outcomes were change in eGFR, 5 mL/min/1.73 m2 or greater eGFR decline, dialysis, and mortality at 1 month postcontrast including primary cause, as well as complications of prophylaxis. Results were stratified by contrast procedure type and corrected for potential confounders.

Results

Of all 55,474 elective procedures with intravascular contrast administration, 362 patients met the inclusion criteria: 281 (78%) received standard 0.9% NaCl prophylaxis and 81 (22%) received no prophylaxis. Prophylaxis versus no prophylaxis adjusted odds ratios were nonsignificant and less than 1 for postcontrast renal outcomes (postcontrast acute kidney injury, eGFR decline, dialysis), indicating a trend toward a protective effect of prophylaxis. For mortality, adjusted odds ratios were nonsignificant and greater than 1, indicating a trend toward higher mortality risk after prophylaxis. Of the primary causes of death analyzed in prophylaxis patients, 24% (5/21) were related to prophylaxis. Among 281 prophylaxis patients, 18 (6.4%) complications of prophylaxis occurred: 15 heart failures and 3 arrhythmias.

Conclusions

Based on this study, no standard recommendation with regard to giving or withholding prophylaxis can be given. Prophylactic fluids may confer some protection against postcontrast renal adverse events but may also contribute toward increased risk of short-term death. In this setting, benefits and risks of prophylaxis must be carefully weighed and cardiac parameters assessed for each individual patient.
Increased Retention of Gadolinium in the Inflamed Brain After Repeated Administration of Gadopentetate Dimeglumine
Authors: Wang Shuangqing , Hesse Bernhard , Roman Marco , Stier Deborah , Castillo-Michel Hiram , Cotte Marine , Suuronen Jussi-Petteri , Lagrange Adrien , Radbruch Helena , Paul Friedemann , Taupitz Matthias , Schellenberger Eyk , Sack Ingolf , Infante-Duarte Carmen
Published: April 2019

Objectives

The aim of this study was to determine in vivo if brain inflammation leads to increased gadolinium (Gd) retention in brain tissue after repeated applications of Gd-based contrast agents (GBCAs).

Materials and Methods

Experimental autoimmune encephalomyelitis (EAE) was induced in female SJL/J mice (n = 6). Experimental autoimmune encephalomyelitis and healthy control mice (n = 4) received 2.5 mmol/kg Gd-DTPA over 10 days (8 injections, cumulated dose of 20 mmol/kg), starting at day 14 post immunization when EAE mice reached the maximal clinical disability. In a group of mice, T1-weighted 2-dimensional RARE images were acquired before the first GBCA injection and 1 day after the last injection. Mice were killed either 1 day or 10 days after the last Gd application. From each single animal, a brain hemisphere was used for Gd detection using inductively coupled plasma mass spectrometry, whereas the other hemisphere was processed for histology and synchrotron x-ray fluorescence spectroscopy (SR-XRF) analysis.

Results

Gadolinium deposition in inflamed brains was mapped by SR-XRF 1 day after the last Gd-DTPA injections, although only mild signal hyperintensity was found on unenhanced T1-weighted images. In addition, using inductively coupled plasma mass spectrometry, we detected and quantified Gd in both healthy and EAE brains up to 10 days after the last injections. However, EAE mouse brains showed higher levels of Gd (mean ± SD, 5.3 ± 1.8 μg/g; range, 4.45–8.03 μg/g) with respect to healthy controls (mean ± SD, 2.4 ± 0.6 μg/g; range, 1.8–3.2 μg/g). By means of micro–SR-XRF, we identified submicrometric Gd hotspots in all investigated samples containing up to 5893 μg Gd/g tissue. Nano–SR-XRF further indicated that Gd small hotspots had an average size of ~160 nm diameter and were located in areas of high inflammatory activity.

Conclusions

After repeated administrations of Gd-DTPA, ongoing inflammation may facilitate the retention of Gd in the brain tissue. Thus, neuroinflammation should be considered as a risk factor in the recommendation on use of linear GBCA-enhanced MRI.
Preventive Effect of Changing Contrast Media in Patients With A Prior Mild Immediate Hypersensitivity Reaction to Gadolinium-Based Contrast Agent
Authors: Ryoo Chang Hyun , Choi Young Hun , Cheon Jung-Eun , Yoon Soon Ho , Kang Hye-Ryun , Park Sae-Jin , Lee Whal
Published: April 2019

Objectives

Currently, the prevention of recurrent immediate hypersensitivity reactions (HSRs) to contrast media (CM) requests premedication and changing the culprit contrast agent. However, strategies for the prevention of immediate HSRs to gadolinium-based magnetic resonance contrast agents (GBCAs) have not yet been established. This study aimed to evaluate the effectiveness of changing the contrast agent and single-dose premedication for HSR recurrence prevention in patients with a history of mild immediate HSR to GBCA.

Materials and Methods

The outcomes of patients with mild immediate HSR to GBCA who subsequently underwent enhanced magnetic resonance imaging between October 2012 and July 2017 were analyzed. The institutional CM monitoring system was retrospectively reviewed, and data on the application of premedication and choice of CM were obtained. Gadolinium-based magnetic resonance contrast agents were classified into 3 classes according to their molecular structure (macrocyclic ionic, macrocyclic nonionic, and linear ionic). Intravenous chlorpheniramine 4 mg, 30 minutes before the GBCA administration, or intravenous methylprednisolone sodium succinate 40 mg plus chlorpheniramine 4 mg, 1 hour before the GBCA administration, was administrated as premedication regimen. Recurrence rates of immediate HSR were compared according to prevention strategies.

Results

A total of 185 patients with a history of mild immediate HSR to GBCA were re-exposed to GBCA 397 times during the study period. The overall recurrence rate was 19.6% (78/397). Changing the culprit GBCA significantly reduced the recurrence rate, compared with reusing the culprit GBCA (6.9%, 9/130 and 25.8%, 69/267; P < 0.001). The recurrence rate was lowest when the GBCA was changed to a different molecular structure class from the culprit agent, followed by changing to CM with the same molecular structure and reusing the culprit GBCA (6.2%, 7/113 vs 11.8%, 2/17 vs 25.8%, 69/267; P < 0.001 with χ2 test for trend). Single-dose premedication demonstrated no significant prophylactic effect on recurrence (20.4%, 17/98 vs 17.3%, 61/299 with and without premedication, respectively; P = 0.509). Premedication in addition to changing CM also showed no additional prophylactic effect (7.2%, 7/97 and 6.1%, 2/33, respectively; P = 0.821).

Conclusions

Changing the CM from the culprit agent could reduce the chance of HSR recurrence in patients with prior mild immediate HSR to GBCA, especially when the CM was changed to one of a different molecular structure class. However, single-dose premedication administration did not show significant HSR recurrence rate difference.
Dual-Source Computed Tomography of the Chest in Blunt Thoracic Trauma
Authors: Liang Teresa , McLaughlin Patrick D. , Nugent James P. , Rai Shamir , Schmiedeskamp Heiko , Louis Luck , Khosa Faisal , Nicolaou Savvas
Published: April 2019

Purpose:

The purpose of this study was to evaluate the clinical utility of temporal resolution optimization (TR-Opt), a computed tomography (CT) postprocessing technique, in reducing aortic motion artifacts in blunt thoracic trauma patients.

Materials and Methods:

This was an IRB-approved study of 61 patients with blunt thoracic trauma carried out between February 18 and September 6, 2014; the patients had been imaged using a standardized dual-source high-pitch (DSHP) CT protocol. Image raw data were retrospectively postprocessed using the TR-Opt algorithm (DSHP-TR-Opt) and compared with conventional images (DSHP). Diagnostic ability to confidently identify and exclude potential injuries and qualitative aortic motion artifacts using a 5-point Likert scale (1=absence of motion artifacts; 5=severe motion artifact) was graded by 2 readers at multiple thoracic locations. Signal-to-noise and contrast-to-noise ratios were generated as quantitative indices of image quality.

Results:

Motion artifacts degrading interpretation and limiting diagnosis of aortic injuries were present in 45% (442/976) of the assessed regions on DSHP. TR-Opt algorithm eliminated motion artifacts in 85% of the motion-degraded areas (375/442), leaving persistent motion artifacts in only 15% (67/442). Motion artifacts were most improved at the interventricular septum (1±1 vs. 3±1), aortic valve (2±1 vs. 4±1.5), and ascending aorta (1±1 vs. 3±2, P<0.005). Mean aorta noise (NAo) was 41.7% higher in the DSHP-TR-Opt images (26.5 vs. 18.7 HU, P<0.0001).

Conclusions:

Temporal resolution optimized reconstruction is a raw data–based CT postprocessing technique that can be used to remove the majority of thoracic aortic motion artifacts that commonly degrade interpretation when imaging blunt thoracic trauma patients.
Intracavitary Coronary Artery
Authors: Hossain Rydhwana , Chelala Lydia , Amin Sagar B. , Bergquist Peter J. , Vairavamurthy Jenanan , Jeudy Jean , White Charles S.
Published: April 2019

Purpose:

A few case reports of intracavitary coronary arteries (ICCA) have been reported and only a single case series on the coronary computed tomography angiography (CCTA) prevalence rate of ICCA of the right coronary artery (RCA). We describe several cases of ICCA that were noted incidentally and also determine the overall prevalence rate of anomalous ICCA.

Materials and Methods:

A retrospective analysis of ICCA was performed consisting of consecutive CCTA cases as well as a group of ICCA from teaching files. To establish a prevalence rate, we reviewed 464 consecutive CCTA referred to our center for transcatheter aortic valve replacement. The presence of ICCA and several imaging features were evaluated.

Results:

Our cohort comprises a total of 12 patients with ICCA, with 1 patient containing 2 anomalous ICCA. 83.3% of affected patients were adult males, with an average age of 69.8 years. The RCA was the most commonly affected vessel (53.8%). The mean length of the intracavitary segment was 33.4 mm for the RCA and 27 mm for the LAD. No cases involved the left circumflex coronary artery. Six of the cases were identified routinely as part of clinical practice and therefore not included in the prevalence analysis. On review of our transcatheter aortic valve replacement database, there was a 1.3% prevalence rate of ICCA. RCA had a prevalence of 0.4%, whereas LAD had a prevalence of 0.9%.

Conclusions:

Although rare, our study suggests that ICCA may be more common than previously described. Its presence is important to communicate to clinicians prior to invasive cardiac procedures to prevent potentially catastrophic outcomes.
Role of Ultrasonography in Severe Distal Median Nerve Neuropathy
Authors: Iyer Vasudeva
Published: April 2019

Purpose:

Electrodiagnostic studies do not differentiate severe lesions of the median nerve in the distal forearm from those within the carpal tunnel when compound muscle action potential over the abductor pollicis brevis and sensory nerve action potential are absent; needle electromyography showing denervation confined to the abductor pollicis brevis is presumed to suggest localization to the carpal tunnel, although the lesion may be in the forearm. Under these circumstances, the patient may undergo carpal tunnel release without benefit. This retrospective study looked at patients with clinical picture of severe carpal tunnel syndrome who had no compound muscle action potential or sensory nerve action potential on median nerve stimulation; the goal was to determine how often ultrasonic imaging pointed to a location other than the carpal tunnel.

Methods:

Patients with clinical picture of severe carpal tunnel syndrome with no sensory nerve action potential and no compound muscle action potential over the abductor pollicis brevis and second lumbrical underwent ultrasonic imaging; criteria for localization to the carpal tunnel included significant increase in the cross-sectional area of the median nerve at the carpal tunnel inlet and increase in the wrist/forearm cross-sectional area ratio.

Results:

In 42 of 46 cases, entrapment at the carpal tunnel was confirmed by ultrasonography; in four patients, other causes were located proximal to the carpal tunnel.

Conclusions:

Ultrasonic imaging is useful not only for confirming entrapment of the median nerve at the carpal tunnel in patients with nonlocalizing electrodiagnostic studies but also in detecting pathology in the forearm, which may mimic severe carpal tunnel syndrome.
Early EEG Features for Outcome Prediction After Cardiac Arrest in Children
Authors: Fung France W. , Topjian Alexis A. , Xiao Rui , Abend Nicholas S.
Published: April 2019

Purpose:

We aimed to determine which early EEG features and feature combinations most accurately predicted short-term neurobehavioral outcomes and survival in children resuscitated after cardiac arrest.

Methods:

This was a prospective, single-center observational study of infants and children resuscitated from cardiac arrest who underwent conventional EEG monitoring with standardized EEG scoring. Logistic regression evaluated the marginal effect of each EEG variable or EEG variable combinations on the outcome. The primary outcome was neurobehavioral outcome (Pediatric Cerebral Performance Category score), and the secondary outcome was mortality. The authors identified the models with the highest areas under the receiver operating characteristic curve (AUC), evaluated the optimal models using a 5-fold cross-validation approach, and calculated test characteristics maximizing specificity.

Results:

Eighty-nine infants and children were evaluated. Unfavorable neurologic outcome (Pediatric Cerebral Performance Category score 4–6) occurred in 44 subjects (49%), including mortality in 30 subjects (34%). A model incorporating a four-level EEG Background Category (normal, slow-disorganized, discontinuous or burst-suppression, or attenuated-flat), stage 2 Sleep Transients (present or absent), and Reactivity–Variability (present or absent) had the highest AUC. Five-fold cross-validation for the optimal model predicting neurologic outcome indicated a mean AUC of 0.75 (range, 0.70–0.81) and for the optimal model predicting mortality indicated a mean AUC of 0.84 (range, 0.76–0.97). The specificity for unfavorable neurologic outcome and mortality were 95% and 97%, respectively. The positive predictive value for unfavorable neurologic outcome and mortality were both 86%.

Conclusions:

The specificity of the optimal model using a combination of early EEG features was high for unfavorable neurologic outcome and mortality in critically ill children after cardiac arrest. However, the positive predictive value was only 86% for both outcomes. Therefore, EEG data must be considered in overall clinical context when used for neuroprognostication early after cardiac arrest.
The rise of the X-ray atomic pair distribution function method: a series of fortunate events
Authors: Billinge Simon J. L.
Published: April 2019

The atomic pair distribution function (PDF) technique is a powerful approach to gain quantitative insight into the structure of materials where the structural coherence extends only over a few nanometres. In this paper, I focus on PDF from synchrotron X-rays and describe what is the PDF and where it came from, as well as key moments on the journey that have contributed to its enormous recent growth and expanding impact in materials science today. Synchrotron X-ray sources played a starring role in this story.

This article is part of the theme issue ‘Fifty years of synchrotron science: achievements and opportunities’.
Preclinical immunoPET imaging of glioblastoma-infiltrating myeloid cells using Zirconium-89-labeled anti-CD11b antibody
Authors: Nigam Shubhanchi , McCarl Lauren , Kumar Rajeev , Edinger Robert S. , Kurland Brenda F. , Anderson Carolyn J. , Panigrahy Ashok , Kohanbash Gary , Edwards W. Barry
Published: April 2019

Purpose

Glioblastoma is a lethal brain tumor, heavily infiltrated by tumor-associated myeloid cells (TAMCs). TAMCs are emerging as a promising therapeutic target as they suppress antitumor immune responses and promote tumor cell growth. Quantifying TAMCs using non-invasive immunoPET could facilitate patient stratification for TAMC-targeted treatments and monitoring of treatment efficacy. As TAMCs uniformly express the cell surface marker, integrin CD11b, we evaluated a89Zr-labeled anti-CD11b antibody for non-invasive imaging of TAMCs in a syngeneic orthotopic mouse glioma model.

Procedures

A human/mouse cross-reactive anti-CD11b antibody (clone M1/70) was conjugated to a DFO chelator and radiolabeled with Zr-89. PET/CT and biodistribution with or without a blocking dose of anti-CD11b Ab were performed 72 hours post-injection of89Zr-anti-CD11b Ab in mice bearing established orthotopic syngeneic GL261 gliomas. Flow cytometry and immunohistochemistry of dissected GL261 tumors were conducted to confirm the presence of CD11b+TAMCs.

Results

Significant uptake of89Zr-anti-CD11b Ab was detected at the tumor site (SUVmean = 2.60 ± 0.24) compared with the contralateral hemisphere (SUVmean = 0.6 ± 0.11). Blocking with a 10-fold lower specific activity of89Zr-anti-CD11b Ab markedly reduced the SUV in the right brain (SUVmean = 0.11 ± 0.06), demonstrating specificity. Spleen and lymph nodes (myeloid cell rich organs) also showed high uptake of the tracer, and biodistribution analysis correlated with the imaging results. CD11b expression within the tumor was validated using flow cytometry and immunohistochemistry, which showed high CD11b expression primarily in the tumoral hemisphere compared to the contralateral hemisphere.

Conclusion

These data establish that89Zr-anti-CD11b Ab immunoPET targets CD11b+cells (TAMCs) with high specificity in a mouse model of GBM, demonstrating the potential for non-invasive quantification of tumor infiltrating CD11b+immune cells during disease progression and immunotherapy in patients with GBM.
Effect of geographic isolation on the nasal virome of indigenous children
Authors: Altan Eda , Carlos Dib Juan , Rojas Gulloso Andres , Escribano Juandigua Duamaco , Deng Xutao , Bruhn Roberta , Hildebrand Kristen , Freiden Pamela , Yamamoto Janie , Schultz-Cherry Stacey , Delwart Eric
Published: April 2019

The influence of living in small remote villages on the diversity of viruses in the nasal mucosa was investigated in three Colombian villages with increasing levels of geographic isolation. Viral metagenomics was used to characterize viral nucleic acids on nasal swabs of 63 apparently healthy young children. Sequences from human virus members of the families Anelloviridae, Papillomaviridae, Picornaviridae, Herpesviridae, Polyomaviridae, Adenoviridae, and Paramyxoviridae were detected in a decreasing fraction of children. The diversity of human viruses was not reduced in the most isolated indigenous Kogi villages. Multiple viral transmission clusters were also identified as closely related variants of rhinoviruses A or B in 2 to 4 children from each of villages. The number of papillomavirus detected was greater in the village most exposed to outside contacts while conversely more anellovirus infections were detected in the more isolated indigenous villages. Genomes of viruses not known to infect humans, including in the family Parvoviridae (genus densoviruses), Partitiviridae, Dicistroviridae, and Iflaviridae and circular Rep expressing ssDNA genomes (CRESS-DNA) were also detected in nasal swabs likely reflecting environmental contamination from insect, fungal, and unknown sources. Despite the high level of geographic and cultural isolation, the diversity of human viruses in the nasal passages of children was not reduced in indigenous villages indicating ongoing exposure to globally circulating viruses.

Importance

Extreme geographic and cultural isolation can still be found in some indigenous South American villages. Such isolation may be expected to limit the introduction of globally circulating viruses. Very small population size may also result in rapid local viral extinction due to lack of sufficient sero-negative subjects to maintain transmission chains of rapidly cleared viruses. We compared the viruses in the nasal passage of young children in three villages with increasing level of isolation. We find that isolation did not reduce the diversity of viral infections in the most isolated villages. Ongoing viral transmission of rhinoviruses could also be detected within all villages. We conclude that despite their geographic isolation remote villages are continuously exposed to globally circulating respiratory viruses.
The Length of Promoter Sequence Affects TheDe NovoInitiation By T7 RNA Polymerase in Vitro: New Insights Into The Evolution of Promoters For Single Subunit RNA Polymerases
Authors: Padmanabhan Ramesh , Miller Dennis
Published: April 2019

1.1

RNA polymerases (RNAPs) differ from other polymerases in that they can bind promoter sequences and initiatede novotranscription. Promoter recognition requires the presence of specific DNA binding domains in the polymerase. The structure and mechanistic aspects of transcription by the bacteriophage T7 RNA polymerase (T7 RNAP) are well characterized. This single subunit RNAP belongs to the family of RNAPs which also includes the T3, SP6 and mitochondrial RNAPs. High specificity for its promoter, the requirement of no additional transcription factors, and high fidelity of initiation from a specific site in the promoter makes it the polymerase of choice to study the mechanistic aspects of transcription. The structure and function of the catalytic domains of this family of polymerases are highly conserved suggesting a common mechanism underlying transcription. Although the two groups of single subunit RNAPs, mitochondrial and bacteriophage, have remarkable structural conservation, they recognize quite dissimilar promoters. Specifically, the bacteriophage promoters recognize a 23 nucleotide promoter extending from −17 to + 6 nucleotides relative to the site of transcription initiation, while the well characterized promoter recognized by the yeast mitochondrial RNAP is nine nucleotides in length extending from −8 to +1 relative to the site of transcription initiation. Promoters recognized by the bacteriophage RNAPs are also well characterized with distinct functional domains involved in promoter recognition and transcription initiation. Thorough mutational studies have been conducted by altering individual base-pairs within these domains. Here we describe experiments to determine whether the prototype bacteriophage RNAP is able to recognize and initiate at truncated promoters similar to mitochondrial promoters. Using anin vitrooligonucleotide transcriptional system, we have assayed transcription initiation activity by T7 RNAP. When a complete or almost complete (20 to 16 nucleotide) double stranded T7 RNAP promoter sequence is present, small RNA’s are produced through template-independent and promoter-dependent stuttering corresponding to abortive initiation, and this effect was lost with a scrambled promoter sequence. When partial double stranded promoter sequences (10 to 12 nucleotides) are supplied, template dependentde novoinitiation of RNA occurs at a site different from the canonical +1-initiation site. The site of transcription initiation is determined by a recessed 3’ end based paired to the template strand of DNA rather than relative to the partial promoter sequence. Understanding the mechanism underlying this observation helps us to understand the role of the elements in the T7 promoter, and provides insights into the promoter evolution of the single-subunit RNAPs.
Behaviors and Energy Source ofMycoplasma gallisepticumGliding
Authors: Mizutani Masaki , Miyata Makoto
Published: April 2019

Mycoplasma gallisepticum, an avian-pathogenic bacterium, glides on host tissue surfaces by using a common motility system withMycoplasma pneumoniae. In the present study, we observed and analyzed the gliding behaviors ofM. gallisepticumin detail by using optical microscopes.M. gallisepticumglided at a speed of 0.27 ± 0.09 µm/s with directional changes relative to the cell axis of 0.6 ± 44.6 degrees/5 s without the rolling of the cell body. To examine the effects of viscosity on gliding, we analyzed the gliding behaviors under viscous environments. The gliding speed was constant in various concentrations of methylcellulose but was affected by Ficoll. To investigate the relationship between binding and gliding, we analyzed the inhibitory effects of sialyllactose on binding and gliding. The binding and gliding speed sigmoidally decreased with sialyllactose concentration, indicating the cooperative binding of the cell. To determine the direct energy source of gliding, we used a membrane-permeabilized ghost model. We permeabilizedM. gallisepticumcells with Triton X-100 or Triton X-100 containing ATP and analyzed the gliding of permeabilized cells. The cells permeabilized with Triton X-100 did not show gliding; in contrast, the cells permeabilized with Triton X-100 containing ATP showed gliding at a speed of 0.014 ± 0.007 μm/s. These results indicate that the direct energy source for the gliding motility ofM. gallisepticumis ATP.

IMPORTANCE

Mycoplasmas, the smallest bacteria, are parasitic and occasionally commensal.Mycoplasma gallisepticumis related to human pathogenicMycoplasmas—Mycoplasma pneumoniaeandMycoplasma genitalium—which causes so-called ‘walking pneumonia’ and non-gonococcal urethritis, respectively. TheseMycoplasmastrap sialylated oligosaccharides, which are common targets among influenza viruses, on host trachea or urinary tract surfaces and glide to enlarge the infected areas. Interestingly, this gliding motility is not related to other bacterial motilities or eukaryotic motilities. Here, we quantitatively analyze cell behaviors in gliding and clarify the direct energy source. The results provide clues for elucidating this unique motility mechanism.
Point mutations in topoisomerase I alter the mutation spectrum in E. coli and impact the emergence of drug resistance genotypes
Authors: Bachar Amit , Itzhaki Elad , Gleizer Shmuel , Shamshoom Melina , Milo Ron , Antonovsky Niv
Published: April 2019

Identifying the molecular mechanisms that give rise to genetic variation is essential for the understanding of evolutionary processes. Previously, we have used adaptive laboratory evolution to enable biomass synthesis from CO2 in E. coli. Genetic analysis of adapted clones from two independently evolving populations revealed distinct enrichment for insertion and deletion mutational events. Here, we follow these observations to show that mutations in the gene encoding for DNA Topoisomerase 1 (topA) give rise to mutator phenotypes with characteristic mutational spectra. Using genetic assays and mutation accumulation lines, we show that point mutations in topA increase the rate of sequence deletion and duplication events. Interestingly, we observe that a single residue substitution (R168C) results in a high rate of head-to-tail (tandem) short sequence duplications, which are independent of existing sequence repeats. Finally, we show that the unique mutation spectrum of topA mutants enhances the emergence of antibiotic resistance in comparison to mismatch-repair (mutS) mutators, and lead to new resistance genotypes. Our findings highlight a potential link between the catalytic activity of topoisomerases and the fundamental question regarding the emergence of de novo tandem repeats, which are known modulators of bacterial evolution.
Distribution and density of oxpeckers on giraffes in Hwange National Park, Zimbabwe
Authors: Gagnon Roxanne , Mabika Cheryl T. , Bonenfant Christophe
Published: April 2019

Oxpeckers (Buphagus sp.) are two bird species closely associated to large mammals, including giraffes (Giraffa camelopardalis). We tested whether oxpeckers distributed themselves at random across individuals or aggregated on individual giraffes, and if birds select the host’s body parts with the expected greatest amount of ticks. By counting oxpeckers on giraffe’s body from photographs, we quantified the distribution of birds per hosts and over predefined zones on the giraffe body. Oxpeckers displayed a strong aggregation behaviour with few hosts carrying many birds while many carried a limited number or no birds, a pattern that was most exaggerated for males. Oxpeckers were disproportionately found on the mane and back, where the density of ticks is presumably the highest. This high aggregation level of birds is typical of parasitic species and could suggest that oxpecker distribution may mirror the distribution of ticks, their primary food resource, on giraffes. Abundance of ticks appears as a major driver of the oxpecker foraging behaviour, and the oxpecker–large herbivores system proves to be highly relevant for the study of host–parasite dynamics.
Population position along the fast-slow life-history continuum predicts intraspecific variation in actuarial senescence
Authors: Cayuela Hugo , Lemaître Jean-François , Bonnaire Eric , Pichenot Julian , Schmidt Benedikt R.
Published: April 2019

Patterns of actuarial senescence can be highly variable among species. Previous comparative analyses revealed that both age at the onset of senescence and rates of senescence are linked to the species’ position along the fast-slow life-history continuum. As there are few long-term datasets of wild populations with known-age individuals, intraspecific (i.e. between-population) variation in senescence is understudied and limited to comparisons of wild and captive populations of the same species, mostly birds and mammals. In this paper, we examined how population position along the fast-slow life history continuum affects senescence patterns in an amphibian,Bombina variegata. We used capture-recapture data collected in four populations with contrasted life history strategies. Senescence trajectories were drawn using Bayesian capture-recapture models. We show that in “slow” populations the onset of senescence was earlier and individuals aged at a faster rate than individuals in “fast” populations. Our study provides one of the few empirical examples of between-population variation in senescence patterns in the wild and confirms that the fast-slow life history gradient is associated with both macroevolutionary and microevolutionary patterns of senescence.
On the cortical mapping function – visual space, cortical space, and crowding
Authors: Strasburger Hans
Published: April 2019

The retino-cortical visual pathway is retinotopically organized: Neighbourhood relationships on the retina are preserved in the mapping to the cortex. Size relationships in that mapping are also highly regular: The size of a patch in the visual field that maps onto a cortical patch of fixed size follows, along any radius and in a wide range, simply a linear function with retinal eccentricity. As a consequence, and under simplifying assumptions, the mapping of retinal to cortical locations follows a logarithmic function along that radius. While this has already been shown by Fischer (1973), the link between the linear function – which describes the local behaviour by the cortical magnification factor M – and the logarithmic location function for the global behaviour, has never been made fully explicit. The present paper provides such a link as a set of ready-to-use equations using Levi and Klein’s E2 nomenclature, and examples for their validity and applicability in the retinotopic mapping literature are discussed. The equations allow estimating M in the retinotopic centre and values thus derived from the literature are provided. A new structural parameter, d2, is proposed to characterize the cortical map, as a cortical counterpart to E2, and typical values for it are given. One pitfall is discussed and spelt out as a set of equations, namely the common myth that a pure logarithmic function will give an adequate map: The popular omission of a constant term renders the equations ill defined in, and around, the retinotopic centre. The correct equations are finally extended to describe the cortical map of Bouma’s law on visual crowding. The result contradicts recent suggestions that critical crowding distance corresponds to a constant cortical distance.