Citations

Heart disease is the leading cause of mortality in the U.S. with approximately 610,000 people dying every year. Effective therapies for many cardiac diseases are lacking, largely due to an incomplete understanding of their genetic basis and underlying molecular mechanisms. Zebrafish (Danio rerio) are an excellent model system for studying heart disease as they enable a forward genetic approach to tackle this unmet medical need. In recent years, our team has been employing electrocardiogram (ECG) as an efficient tool to study the zebrafish heart along with conventional approaches, such as immunohistochemistry, DNA and protein analyses. We have overcome various challenges in the small size and aquatic environment of zebrafish in order to obtain ECG signals with favorable signal-to-noise ratio (SNR), and high spatial and temporal resolution. In this paper, we highlight our recent efforts in zebrafish ECG acquisition with a cost-effective simplified microelectrode array (MEA) membrane providing multi-channel recording, a novel multi-chamber apparatus for simultaneous screening, and a LabVIEW program to facilitate recording and processing. We also demonstrate the use of machine learning-based programs to recognize specific ECG patterns, yielding promising results with our current limited amount of zebrafish data. Our solutions hold promise to carry out numerous studies of heart diseases, drug screening, stem cell-based therapy validation, and regenerative medicine.

ABSTRACTDegenerative disk disease of the spine is a major cause of back pain and disability. Optimization of regenerative medical therapies for degenerative disk disease requires a deep mechanistic understanding of the factors controlling the structural integrity of spinal tissues. In this investigation, we sought to identify candidate regulatory genes controlling extracellular matrix synthesis in spinal tissues. To achieve this goal we performed high throughput next generation RNA sequencing on 39 annulus fibrosus and 21 nucleus pulposus human tissue samples. Specimens were collected from patients undergoing surgical discectomy for the treatment of degenerative disk disease. Our studies identified associations between extracellular matrix genes, growth factors, and other important regulatory molecules. The fibrous matrix characteristic of annulus fibrosus was associated with expression of the growth factors platelet derived growth factor beta (PDGFB), vascular endothelial growth factor C (VEGFC), and fibroblast growth factor 9 (FGF9). Additionally we observed high expression of multiple signaling proteins involved in the NOTCH and WNT signaling cascades. Nucleus pulposus extracellular matrix related genes were associated with the expression of numerous diffusible growth factors largely associated with the transforming growth signaling cascade, including transforming factor alpha (TGFA), inhibin alpha (INHA), inhibin beta A (INHBA), bone morphogenetic proteins (BMP2, BMP6), and others. Clinical significance: this investigation provides important data on extracellular matrix gene regulatory networks in disk tissues. This information can be used to optimize pharmacologic, stem cell, and tissue engineering strategies for regeneration of the intervertebral disk and the treatment of back pain. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1356–1369, 2018.

Background: Following anterior cruciate ligament (ACL) reconstruction, the mechanical loading of the tissues has a significant impact on tendon-to-bone healing. The purpose of this study was to determine the effect of the timing of the initiation of mechanical loading on healing of a tendon graft in a bone tunnel. Methods: ACL reconstruction using a flexor tendon autograft was performed in 56 mice randomized to 4 groups with differing times to initiation of postoperative mechanical loading: (1) immediate, (2) 5 days, (3) 10 days, or (4) 21 days following surgery. An external fixator was placed across the knee at the time of surgery and removed when mechanical loading was scheduled to commence. Following removal of the external fixator, animals were permitted free, unrestricted cage activity. All mice were killed on postoperative day 28, and tendon-to-bone healing was assessed by biomechanical testing, microcomputed tomography (micro-CT), and histological analysis. Results: The mean failure force (and standard deviation) of the reconstructed ACL at the time of sacrifice was highest for Group 2 (3.29 ± 0.68 N) compared with Groups 1, 3, and 4 (p = 0.008). Micro-CT bone volume fraction was greatest for Group 2 in the femoral tunnel (p = 0.001), tibial tunnel (p = 0.063), and both bones (p < 0.001). Similarly, histological analysis demonstrated a narrower scar tissue interface and increased direct contact at the tendon-bone interface (p = 0.012) for Group 2. Conclusions: Following ACL reconstruction, a defined period of immobilization without weight-bearing appears to improve biomechanical strength of the healing tendon-bone interface, while prolonged periods without mechanical load and motion decrease the ultimate load to failure in this murine model. Clinical Relevance: The ideal period of restricted weight-bearing and motion following ACL reconstruction remains undefined. In a murine model, improved healing was noted for animals immobilized for a brief period of 5 days. This work may serve as an initial step in determining the ideal time period in a clinical population.

Various pathophysiological conditions such as surfactant dysfunction, mechanical ventilation, inflammation, pathogen products, environmental exposures, and gastric acid aspiration stress lung cells, and the compromise of plasma membranes occurs as a result. The mechanisms necessary for cells to repair plasma membrane defects have been extensively investigated in the last two decades, and some of these key repair mechanisms are also shown to occur following lung cell injury. Because it was theorized that lung wounding and repair are involved in the pathogenesis of acute respiratory distress syndrome (ARDS) and idiopathic pulmonary fibrosis (IPF), in this review, we summarized the experimental evidence of lung cell injury in these two devastating syndromes and discuss relevant genetic, physical, and biological injury mechanisms, as well as mechanisms used by lung cells for cell survival and membrane repair. Finally, we discuss relevant signaling pathways that may be activated by chronic or repeated lung cell injury as an extension of our cell injury and repair focus in this review. We hope that a holistic view of injurious stimuli relevant for ARDS and IPF could lead to updated experimental models. In addition, parallel discussion of membrane repair mechanisms in lung cells and injury-activated signaling pathways would encourage research to bridge gaps in current knowledge. Indeed, deep understanding of lung cell wounding and repair, and discovery of relevant repair moieties for lung cells, should inspire the development of new therapies that are likely preventive and broadly effective for targeting injurious pulmonary diseases.

AbstractControl of knee motion in small animal models is necessary to study the effect of mechanical load on the healing process. This can be especially challenging in mice, which are being increasingly used for various orthopedic reconstruction models. We explored the feasibility of botulinum toxin (Botox; Allergan, Dublin, Ireland) paralysis and a newly designed external fixator to restrict motion of the knee in mice undergoing anterior cruciate ligament (ACL) reconstruction. Nineteen C57BL/6 mice were allocated to two groups: (1) Botox group (n = 9) and (2) external fixator group (n = 10). Mice in Botox group received two different doses of Botox: 0.25 unit (n = 3) and 0.5 unit (n = 6). Injection was performed 72 hours prior to ACL reconstruction into the quadriceps, hamstring, and calf muscles of the right hind leg. Mice in external fixator group received an external fixator following ACL reconstruction. Mice were monitored for survival, tolerance, and achievement of complete knee immobilization. All mice were meant for sacrifice on day 14 postoperatively. No perceptible change in gait was observed with 0.25 unit of Botox. All mice that received 0.5 unit of Botox had complete hind limb paralysis documented by footprint analysis 2 days after injection but failed to tolerate anesthesia and were euthanized 24 hours after operation due to their critical condition. In contrast, the external fixator was well tolerated and effectively immobilized the limb. There was a single occurrence of intraoperative technical error in the external fixator group that led to euthanasia. No mechanical failure or complication was observed. Botox paralysis was not a viable option for postoperative restriction of motion and joint loading in mice. However, external fixation was an effective method for complete knee immobilization and can be used in murine models requiring postoperative control of knee loading. This study introduces a robust research tool to allow control of postoperative joint loading in animal models such as ACL reconstruction, permitting study of the effects of mechanical load on the biologic aspects of tendon-to-bone healing.

Abstract Background: The need remains for novel agents that prolong survival and/or improve QOL in women with aBC. EP is a long-acting topoisomerase 1 inhibitor engineered to produce sustained exposure to irinotecan and its active metabolite SN38. Given previous efficacy seen in an earlier phase II trial in MBC, EP 145 mg/m2 every 3 weeks was compared to TPC (one of 7 single-agent regimens) in the randomized phase 3 BEACON study (NCT01492101). As reported at ASCO 2015 (abstract 1001), EP prolonged median overall survival by 2.1 months, although this did not reach statistical significance (12.4 vs 10.3 months; HR 0.87, p=0.08). Grade ≥ 3 adverse events were significantly less common with EP (48% vs 63% with TPC, p&lt;0.001). We now present results of the QOL analyses. Methods: Patients completed validated health-related QoL (HRQoL) questionnaires, EORTC QLQ-C30 (version 3.0) and breast cancer-specific QLQ-BR23, pretreatment and every 8 weeks until progression, death or withdrawal of consent. Questionnaires were scored according to the EORTC manual. For each scale, raw scores were standardized via a linear transformation to a range from 0 to 100. Absolute scores and changes from baseline were analyzed longitudinally and categorically using a 5-point difference calculated by treatment group. Comparisons between treatment groups were conducted to evaluate the differences in global health status, functional scores and symptoms over time. Results: The majority of patients who were randomized (total: 733/852 [86%], EP: 378/429 [88%], TPC: 355/423 [84%]) completed at least one post-baseline HRQoL questionnaire. In the EORTC QLQ-C30, grade ≥ 3 AEs significantly impacted HRQoL measured by global health status and 5 additional functional domains. Of the six domains, compared to TPC in a longitudinal analysis, EP was statistically superior in the mean treatment effect through Week 32 in global health status p=0.02 and physical functioning scale p=0.01. EP was also numerically superior in all other scales. In EORTC QLQ-C30 and BR-23, a total of 13 symptoms were measured and categorically analyzed. There were no treatment differences in 7 of 13 symptom scales. EP was associated with worsening of 3 symptom scales: appetite loss, nausea/vomiting, and diarrhea. TPC was associated with worsening of 2 symptom scales: dyspnea and systemic side effects. Conclusions: In the phase 3 BEACON trial comparing EP to TPC, the more favorable toxicity profile of EP resulted in an improvement in global health status and physical function (results of the symptom scales confirmed the different toxicities of the two arms). EP remains a promising investigational therapy for aBC. Citation Format: Cortes J, Awada A, Perez EA, Rugo HS, Twelves C, Im S-A, Zhao C, Hoch U, Ney J, Hannah AL, O'Shaughnessy J. Impact of treatment on quality of life (QOL) in the BEACON study, a randomized phase III trial of etirinotecan pegol (EP) versus treatment of physician's choice (TPC) in patients (pts) with advanced breast cancer (aBC) whose disease has progressed following anthracycline (A), taxane (T) and capecitabine (C). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-11-08.

OBJECT Anterior nuclear (AN) stimulation has been reported to reduce the frequency of seizures, in some cases dramatically; however, it has not been approved by the US Food and Drug Administration. The anterior nucleus is difficult to target because of its sequestered location, partially surrounded by the ventricle. It has traditionally been targeted by using transventricular or lateral transcortical routes. Here, the authors report a novel approach to targeting the anterior nucleus and neurophysiologically confirming effective stimulation of the target, namely evoked potentials in the hippocampus. METHODS Bilateral AN 3389 electrodes were placed in a novel trajectory followed by bilateral hippocampal 3391 electrodes from a posterior trajectory. Each patient was implanted bilaterally with a Medtronic Activa PC+S device under an investigational device exemption approval. Placement was confirmed with CT. AN stimulation-induced hippocampal evoked potentials were measured to functionally confirm placement in the anterior nucleus. RESULTS Two patients had implantations by way of a novel AN trajectory with concomitant hippocampal electrodes. There were no lead misplacements. Postoperative stimulation of the anterior nucleus with a PC+S device elicited evoked potentials in the hippocampus. Thus far, both patients have reported a > 50% improvement in seizure frequency. CONCLUSIONS Placing AN electrodes posteriorly may provide a safer trajectory than that used for traditionally placed AN electrodes. In addition, with a novel battery that is capable of electroencephalographic recording, evoked potentials can be used to functionally assess the Papez circuit. This treatment paradigm may offer increased AN stimulation efficacy for medically intractable epilepsy by assessing functional placement more effectively and thus far has proven safe.