Custom-engineered hydrogels for delivery of human iPSC-derived neurons into the injured cervical spinal cord

Cervical damage is the most prevalent type of spinal cord injury clinically, although few preclinical research studies focus on this anatomical region of injury. Here we present a combinatorial therapy composed of a custom-engineered, injectable hydrogel and human induced pluripotent stem cell (iPSC)-derived deep cortical neurons. The biomimetic hydrogel has a modular design that includes a protein-engineered component to allow customization of the cell-adhesive peptide sequence and a synthetic polymer component to allow customization of the gel mechanical properties. In vitro studies with encapsulated iPSC-neurons were used to select a bespoke hydrogel formulation that maintains cell viability and promotes neurite extension. Following injection into the injured cervical spinal cord in a rat contusion model, the hydrogel biodegraded over six weeks without causing any adverse reaction. Compared to cell delivery using saline, the hydrogel significantly improved the reproducibility of cell transplantation and integration into the host tissue. Across three metrics of animal behavior, this combinatorial therapy significantly improved sensorimotor function by six weeks post transplantation. Taken together, these findings demonstrate that design of a combinatorial therapy that includes a gel customized for a specific fate-restricted cell type can induce regeneration in the injured cervical spinal cord.

Scrambler Therapy for Patients With Complex Regional Pain Syndrome: A Case Series

Complex regional pain syndrome is a chronic debilitating pain disorder that is difficult to manage, in part due to its heterogeneous clinical presentation and lack of clearly defined pathophysiology. Patients usually require a multidisciplinary approach to treatment, which can entail pharmacotherapy, physical therapy, behavioral therapy, and interventional pain procedures, such as sympathetic nerve blocks, spinal cord stimulation, and dorsal root ganglion stimulation. However, many patients continue to experience pain refractory to these multimodal strategies. Scrambler therapy (ST) is a noninvasive method of neuromodulation that is applied through cutaneous electrodes, and can alleviate chronic neuropathic pain by stimulating C-fibers and replacing endogenous pain signals with synthetic non-nociceptive signals. Although the use of ST has been reported for several types of refractory central and peripheral neuropathic pain, there is a paucity of data regarding the use of ST for complex regional pain syndrome. We present two patients with complex regional pain syndrome of the right lower extremity, who each underwent ST and experienced significant pain relief and improvement in function and quality of life.

Prominent Eustachian Valve Mimicking Inferior Rim of Atrial Septum Causing Iatrogenic Inferior Vena Cava Type Sinus Venosus Atrial Septal Defect

The Eustachian valve is an embryologic remnant at the junction of the inferior vena cava (IVC) and right atrium (RA). While it typically does not have any pathologic significance, veno-arterial shunting can rarely occur in patients with prominent eustachian valves and atrial septal defects (ASD), causing cyanosis and hypoxemia despite normal pulmonary pressures. We present a case of a patient with iatrogenic residual sinus venosus IVC-type ASD secondary to a prominent Eustachian valve that was misinterpreted as the inferior rim of the atrial septum during initial ASD repair.

Using Lean Six Sigma to Decrease Delivery Time of Blood Products to the Operating Room

Lean Six Sigma (LSS) is a process improvement strategy used in many industries. Its goal is to improve performance and quality by eliminating waste, optimizing flow, and reducing variability. This article describes LSS methods and their application in health care. We detail a successful quality improvement (QI) initiative in which we tested LSS tools to evaluate and enhance our institution's blood product delivery to the operating room (OR). Incorporating LSS-driven changes resulted in a revised workflow, which decreased personnel workload and significantly reduced delivery time. We hope this article will encourage other health care institutions to integrate LSS strategies into their workflows.

Computer-generated photorealistic hologram using ray-wavefront conversion based on the additive compressive light field approach

The conventional computer-generated hologram reconstructing photorealistic three-dimensional (3D) images based on ray-wavefront conversion has the disadvantage of spatio-angular resolution trade-off. In this Letter, we propose for the first time, to the best of our knowledge, a computer-generated photorealistic hologram without spatio-angular resolution trade-off based on the additive compressive light field (CLF) approach. The original light field is compressed into multiple layer images through numerical optimization based on the additive light field principle. Then, by independently calculating the wave propagation from each layer image to the hologram plane and adding them together, a CLF hologram is generated. Since the CLF information is presented through a holographic method, the advantage of high resolution in CLF is preserved while the limitation of the number of physically stacked layers (such as liquid crystal displays) is removed, leading to higher quality, larger depth of field, and higher brightness compared with a conventional CLF display. The proposed method is verified with a photorealistic optical experiment.

Long-term denosumab treatment restores cortical bone loss and reduces fracture risk at the forearm and humerus: analyses from the FREEDOM Extension cross-over group

Upper limb fractures (including wrist, forearm, and humerus) represent a significant burden among postmenopausal women with osteoporosis. Up to 7 years of treatment with denosumab resulted in an increase in bone mineral density and decrease in fractures in upper limb sites.

INTRODUCTION

Upper limb (wrist, forearm, and humerus) fractures are a significant burden in osteoporosis, associated with significant morbidity and mortality. Denosumab, a monoclonal antibody against RANK ligand, increases bone mineral density (BMD) and decreases vertebral, nonvertebral, and hip fractures. Here, we evaluated the long-term effect of denosumab treatment on upper limb fracture risk and BMD.

METHODS

In the FREEDOM trial, subjects were randomized 1:1 to receive every-6-month denosumab 60 mg or placebo subcutaneously for 3 years, after which all subjects could receive denosumab for up to 7 years (Extension). Among placebo subjects who completed FREEDOM and enrolled in the Extension, wrist, forearm, humerus, and upper limb fracture rates and rate ratios between different time periods (FREEDOM years 1-3, Extension years 1-3, and Extension years 4-7) were computed. BMD at the ultradistal radius, 1/3 radius, and total radius was analyzed in a subset of subjects in a BMD substudy.

RESULTS

This analysis included 2207 subjects (116 in the BMD substudy). Fracture rates decreased over the 7-year Extension; fracture rate ratios between Extension years 4-7 (denosumab) and FREEDOM years 1-3 (placebo) reduced significantly for the wrist (0.57), forearm (0.57), humerus (0.42), and upper limb (0.52; p < 0.05 for all). Percentage increase in BMD from Extension baseline at the ultradistal radius, 1/3 radius, and total radius was significant by Extension year 7 (p < 0.05 for all).

CONCLUSIONS

Long-term treatment with denosumab decreases upper limb fracture risk and increases forearm BMD, suggesting beneficial effects on both cortical and trabecular bone accruing over time.

Resolution priority holographic stereogram based on integral imaging with enhanced depth range

Conventional holographic stereogram (HS) can be generated through fast Fourier transforming parallax images into hogels. Conventional HS uses multiple plane waves to reconstruct 3D images with low resolution and is similar to the principle of depth priority integral imaging (II). We proposed the concept of resolution priority HS for the first time, which is based on the principle of resolution priority II, by adding a quadratic phase term on the conventional Fourier transform. In the proposed resolution priority HS, the resolution of reconstructed 3D images is much better than conventional HS, but the depth range is limited. To enhance the depth range, a multi-plane technique was used to present multiple central depth planes simultaneously. The proposed resolution priority HS with high resolution and enhanced depth range was verified by both simulation and optical experiment.

Simulation training for breast and pelvic physical examination: a systematic review and meta-analysis

BACKGROUND

Breast and pelvic examinations are challenging intimate examinations. Technology-based simulation may help to overcome these challenges.

OBJECTIVE

To synthesise the evidence regarding the effectiveness of technology-based simulation training for breast and pelvic examination.

SEARCH STRATEGY

Our systematic search included MEDLINE, EMBASE, CINAHL, PsychINFO, Scopus, and key journals and review articles; the date of the last search was January 2012.

SELECTION CRITERIA

Original research studies evaluating technology-enhanced simulation of breast and pelvic examination to teach learners, compared with no intervention or with other educational activities.

DATA COLLECTION AND ANALYSIS

The reviewers evaluated study eligibility and abstracted data on methodological quality, learners, instructional design, and outcomes, and used random-effects models to pool weighted effect sizes.

MAIN RESULTS

In total, 11 272 articles were identified for screening, and 22 studies were eligible, enrolling 2036 trainees. In eight studies comparing simulation for breast examination training with no intervention, simulation was associated with a significant improvement in skill, with a pooled effect size of 0.86 (95% CI 0.52-1.19; P < 0.001). Four studies comparing simulation training for pelvic examination with no intervention had a large and significant benefit, with a pooled effect size of 1.18 (95% CI 0.40-1.96; P = 0.003). Among breast examination simulation studies, dynamic models providing feedback were associated with improved outcomes. In pelvic examination simulation studies, the addition of a standardised patient to the simulation model and the use of an electronic model with enhanced feedback improved outcomes.

AUTHOR'S CONCLUSIONS

In comparison with no intervention, breast and pelvic examination simulation training is associated with moderate to large effects for skills outcomes. Enhanced feedback appears to improve learning.

Sonoporation enhances chemotherapeutic efficacy in retinoblastoma cells in vitro

PURPOSE

To study the ability of ultrasound (US) and microbubbles (MB) to enhance chemotherapeutic efficacy against retinoblastoma Y79 cells in vitro.

METHODS

The experiment was performed in three stages. The authors first compared cell viability of Y79 cells exposed to doxorubicin versus cells exposed to doxorubicin combined with low-intensity, low-frequency US + MB. They then evaluated enhanced cell permeability by studying the intensity of intracellular fluorescence in cells exposed to doxorubicin versus those exposed to doxorubicin with US + MB. Lastly they evaluated the morphologic characteristics of the cells by scanning electron microscopy (SEM) to identify the presence of pores.

RESULTS

The Y79 cells exposed to doxorubicin with US + MB showed a significant decrease in cell viability at 72 hours compared with those exposed to doxorubicin alone (P = 0.02). Cells also showed immediate increased permeability to doxorubicin with the addition of US + MB compared with doxorubicin alone, which continued to increase over 60 minutes. SEM did not demonstrate physical pores at the lowest US + MB intensity shown to enhance intracellular doxorubicin fluorescence.

CONCLUSIONS

US + MB facilitates the uptake of chemotherapy in retinoblastoma Y79 cells in vitro. This occurs in the absence of visible pores, suggesting a possible secondary mechanism for increased drug delivery. This experiment is the first step toward enhancing chemotherapy with sonoporation in the treatment of intraocular tumors. This technique may lead to more effective chemotherapy treatments with less collateral damage to ocular tissues and may allow reduced systemic dosage and systemic side effects.

Electron paramagnetic resonance and nanosecond fluorescence depolarization studies on creatine-phosphokinase interaction with myosin and its fragments

Recent reports in the literature have indicated a physical association of creatine-phosphokinase (CPK) with the tail portion of the myosin molecule. The present paper describes further studies on the interaction of CPK with myosin and myosin fragments, using the techniques of electron paramagnetic resonance (EPR) and nanosecond fluorescence depolarization. From EPR work, spin-labeled CPK appears to interact with myosin, tail-less myosin (heavy meromyosin [HMM]), and myosin heads (subfragment-1 [S1]), the extent of interaction being proportional to the S1 content of myosin or its fragments. Spin-labeled CPK did not evidence interaction with the headless myosin "rods," with myosin tails (light meromyosin [LMM]), with S2 necks (which connect S1 to the rest of the myosin molecule), or with actin. When a fluorescent dye is directed to the essential epsilon-amino group of CPK, nanosecond fluorescence depolarization studies indicate a substantial interaction with myosin, HMM, and S1, but very little with F-actin. When the "fast-reacting" thiol of the S1 moiety or the "essential thiol" of CPK was labeled with either a fluorescent dye or a spin label, no interaction between CPK and myosin (or S1) was detected.