Modulation of effector caspase cleavage determines response of breast and lung tumor cell lines to chemotherapy

In spite of compelling evidence-implicating caspases in drug-induced apoptosis, how tumors modulate caspase expression and activity to overcome the cytotoxicity of anticancer agents is not fully understood. To address this issue, we investigated the role of caspases-3 and caspase-7 in determining the response of breast and lung tumor cell lines to chemotherapy. We found that an early and late apoptotic response correlated with weak and strong cellular caspase-activation, respectively. The results highlight an underappreciated relationship of temporal apoptotic response with caspase-activation and drug resistance. Moreover, the extent of tumor growth restoration after drug withdrawal was dependent on the degree of endogenous blockage of caspase-3 and caspase-7 cleavages. This points to an unrecognized role of caspase modulation in tumor recurrence and suggests that targeting caspase cleavage is a rational approach to increasing potency of cancer drugs.

Carpal Tunnel Release Surgery- A Systematic Review of Open and Endoscopic Approaches

CONTEXT

Carpal tunnel syndrome (CTS) is the most frequent peripheral compression-induced neuropathy observed in patients worldwide. Surgery is necessary when conservative treatments fail and severe symptoms persist. Traditional Open carpal tunnel release (OCTR) with visualization of carpal tunnel is considered the gold standard for decompression. However, Endoscopic carpal tunnel release (ECTR), a less invasive technique than OCTR is emerging as a standard of care in recent years.

EVIDENCE ACQUISITION

Criteria for this systematic review were derived from Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Two review authors searched PubMed, MEDLINE, and the Cochrane Database in May 2018 using the following MeSH terms from 1993-2016: 'carpal tunnel syndrome,' 'median nerve neuropathy,' 'endoscopic carpal tunnel release,' 'endoscopic surgery,' 'open carpal tunnel release,' 'open surgery,' and 'carpal tunnel surgery.' Additional sources, including Google Scholar, were added. Also, based on bibliographies and consultation with experts, appropriate publications were identified. The primary outcome measure was pain relief.

RESULTS

For this analysis, 27 studies met inclusion criteria. Results indicate that ECTR produced superior post-operative pain outcomes during short-term follow-up. Of the studies meeting inclusion criteria for this analysis, 17 studies evaluated pain as a primary or secondary outcome, and 15 studies evaluated pain, pillar tenderness, or incision tenderness at short-term follow-up. Most studies employed a VAS for assessment, and the majority reported superior short-term pain outcomes following ECTR at intervals ranging from one hour up to 12 weeks. Several additional studies reported equivalent pain outcomes at short-term follow-up as early as one week. No study reported inferior short-term pain outcomes following ECTR.

CONCLUSIONS

ECTR and OCTR produce satisfactory results in pain relief, symptom resolution, patient satisfaction, time to return to work, and adverse events. There is a growing body of evidence favoring the endoscopic technique for pain relief, functional outcomes, and satisfaction, at least in the early post-operative period, even if this difference disappears over time. Several studies have demonstrated a quicker return to work and activities of daily living with the endoscopic technique.

Gait features for discriminating between mobility-limiting musculoskeletal disorders: Lumbar spinal stenosis and knee osteoarthritis

BACKGROUND

Functional ambulation limitations are features of lumbar spinal stenosis (LSS) and knee osteoarthritis (OA). With numerous validated walking assessment protocols and a vast number of spatiotemporal gait parameters available from sensor-based assessment, there is a critical need for selection of appropriate test protocols and variables for research and clinical applications.

RESEARCH QUESTION

In patients with knee OA and LSS, what are the best sensor-derived gait parameters and the most suitable clinical walking test to discriminate between these patient populations and controls?

METHODS

We collected foot-mounted inertial measurement unit (IMU) data during three walking tests (fast-paced walk test-FPWT, 6-min walk test- 6MWT, self-paced walk test - SPWT) for subjects with LSS, knee OA and matched controls (N = 10 for each group). Spatiotemporal gait characteristics were extracted and pairwise compared (Omega partial squared - ω_p²) between patients and controls.

RESULTS

We found that normal paced walking tests (6MWT, SPWT) are better suited for distinguishing gait characteristics between patients and controls. Among the sensor-based gait parameters, stance and double support phase timing were identified as the best gait characteristics for the OA population discrimination, whereas foot flat ratio, gait speed, stride length and cadence were identified as the best gait characteristics for the LSS population discrimination.

SIGNIFICANCE

These findings provide guidance on the selection of sensor-derived gait parameters and clinical walking tests to detect alterations in mobility for people with LSS and knee OA.

Reconceptualizing balance: attributes associated with balance performance

Balance tests are commonly used to screen for impairments that put older adults at risk for falls. The purpose of this study was to determine the attributes that were associated with balance performance as measured by the Frailty and Injuries: Cooperative Studies of Intervention Techniques (FICSIT) balance test. This study was a cross-sectional secondary analysis of baseline data from a longitudinal cohort study, the Boston Rehabilitative Impairment Study of the Elderly (Boston RISE). Boston RISE was performed in an outpatient rehabilitation research center and evaluated Boston area primary care patients aged 65 to 96 (N=364) with self-reported difficulty or task-modification climbing a flight of stairs or walking 1/2 of a mile. The outcome measure was standing balance as measured by the FICSIT-4 balance assessment. Other measures included: self-efficacy, pain, depression, executive function, vision, sensory loss, reaction time, kyphosis, leg range of motion, trunk extensor muscle endurance, leg strength and leg velocity at peak power. Participants were 67% female, had an average age of 76.5 (±7.0) years, an average of 4.1 (±2.0) chronic conditions, and an average FICSIT-4 score of 6.7 (±2.2) out of 9. After adjusting for age and gender, attributes significantly associated with balance performance were falls self-efficacy, trunk extensor muscle endurance, sensory loss, and leg velocity at peak power. FICSIT-4 balance performance is associated with a number of behavioral and physiologic attributes, many of which are amenable to rehabilitative treatment. Our findings support a consideration of balance as multidimensional activity as proposed by the current International Classification of Functioning, Disability, and Health (ICF) model.

Differential activity of caspase-3 regulates susceptibility of lung and breast tumor cell lines to Paclitaxel

Recent development of tumor resistance to paclitaxel presents a major problem to cancer treatment. An unsettled controversy in the cancer chemotherapy field, however, is whether caspases play a prominent role in paclitaxel-induced death in tumors. Previous studies suggest that cleavage of caspase-3 is not instrumental for the execution of death in tumors treated with paclitaxel, while other reports indicate that caspase-dependent pathways may be critical for paclitaxel cytotoxicity. In this study, we investigated the role of caspase-3 in breast and lung tumor cell line sensitivity to paclitaxel. Clonogenic survival and live/dead viability-assays, together with enzymatic activity and cell proliferation assays, reveal that the levels of paclitaxel-induced caspase-3 enzymatic activity in tumor cells correlate directly with tumor sensitivity to the drug.We observed a 2-fold increase in caspase-3 activity in 4T1-Luc breast tumor cells, but a 3-fold and 4-fold decrease in A549 and A427 lung tumor cell lines, respectively. Together, our results suggest that caspase-activation and activity levels are not only key determinants of paclitaxel-induced death in tumors but also serve as good indicators for tumor susceptibility to paclitaxel therapy. Our studies also indicate that within clinically relevant doses of paclitaxel, the ability to rid tumor populations of dormant tumor cells controls the rate of tumor recurrence.

Minding the Gaps in Cancer Pain Management Education: A Multicenter Study of Clinical Residents and Fellows in a Low- Versus High-Resource Setting

Purpose

Inadequate pain management training has been reported as a major cause of undertreatment of cancer pain. Yet, past research has not comprehensively compared the quality of cancer pain management education among physicians in training in high-resource countries (HRCs) with those in low-resource countries (LRCs). The purpose of this study was to examine and compare gaps in cancer pain management education among physician trainees in an HRC (United States) versus an LRC (Ghana).

Methods

A cross section of physicians at four major academic medical centers completed surveys about the adequacy of cancer pain training. Participation in the study was completely voluntary, and paper or online surveys were completed anonymously.

Results

The response rate was 60% (N = 120). Major gaps were identified in cancer pain management education across the spectrum of medical school training. Training was rated as inadequate (by approximately 80% of trainees), although approximately 10% more trainees in HRCs versus LRCs felt this way; 35% said residency training was inadequate in both settings; and 50% in LRCs versus 44% in HRCs said fellowship training was less than good. On the basis of the lowest group means, the three key areas of perceived deficits included interventional pain procedures (2.34 ± 1.12), palliative care interventions (2.39 ± 1.12), and managing procedural and postoperative pain (2.94 ± 0.97), with significant differences in the distribution of deficits in 15 cancer-pain competencies between LRCs and HRCs (P < .05).

Conclusion

This study identifies priority areas that could be targeted synergistically by LRCs and HRCs to advance cancer care globally. The findings underscore differential opportunities to broaden and improve competencies in cancer pain management via exchange training, in which physicians from HRCs spend time in LRCs and vice versa.

Correction to: Role of Alpha-2-Microglobulin in the Treatment of Osteoarthritic Knee Pain: a Brief Review of the Literature

The original publication listed author Alan Kaye as "A. Kaye," but his name should read "A.D. Kaye." The correct author name is presented in this article.

Multifunctional Thio-Stabilized Gold Nanoparticles for Near-Infrared Fluorescence Detection and Imaging of Activated Caspase-3

Background

Gold nanoparticles (AuNPs) are commonly used in nanomedicine because of their unique spectral properties, chemical and biological stability, and ability to quench the fluorescence of organic dyes attached to their surfaces. However, the utility of spherical AuNPs for activatable fluorescence sensing of molecular processes have been confined to resonance-matched fluorophores in the 500 nm to 600 nm spectral range to maximize dye fluorescence quenching efficiency. Expanding the repertoire of fluorophore systems into the NIR fluorescence regimen with emission >800 nm will facilitate the analysis of multiple biological events with high detection sensitivity.

Objective

The primary goal of this study is to determine if spherical AuNP-induced radiative rate suppression of non-resonant near-infrared (NIR) fluorescent probes can serve as a versatile nanoconstruct for highly sensitive detection and imaging of activated caspase-3 in aqueous media and cancer cells. This required the development of activatable NIR fluorescence sensors of caspase-3 designed to overcome the nonspecific degradation and release of the surface coatings in aqueous media.

Method

We harnessed the fluorescence-quenching properties and multivalency of spherical AuNPs to develop AuNP-templated activatable NIR fluorescent probes to detect activated caspase-3, an intracellular reporter of early cell death. Freshly AuNPs were coated with a multifunctional NIR fluorescent dye-labeled peptide (LS422) consisting of an RGD peptide sequence that targets α_vβ₃-integrin protein (α_vβ₃) on the surface of cancer cells to mediate the uptake and internalization of the sensors in tumor cells; a DEVD peptide sequence for reporting the induction of cell death through caspase-3 mediated NIR fluorescence enhancement; and a multidentate hexacysteine sequence for enhancing self-assembly and stabilizing the multifunctional construct on AuNPs. The integrin binding affinity of LS422 and caspase-3 kinetics were determined by a radioligand competitive binding and fluorogenic peptide assays, respectively. Detection of intracellular caspase-3, cell viability, and the internalization of LS422 in cancer cells were determined by confocal NIR fluorescence spectroscopy and microscopy.

Results

Narrow size AuNPs (13 nm) were prepared and characterized by transmission electron microscopy and dynamic light scattering. When assembled on the AuNPs, the binding constant of LS422 for α_vβ₃ improved 11-fold from 13.2 nM to 1.2 nM. Whereas the catalytic turnover of caspase-3 by LS422-AuNPs was similar to the reference fluorogenic peptide, the binding affinity for the enzyme increased by a factor of 2. Unlike the α_vβ₃ positive, but caspase-3 negative breast cancer MCF-7 cells, treatment of the α_vβ₃ and caspase-3 positive lung cancer A549 cells with Paclitaxel showed significant fluorescence enhancement within 30 minutes, which correlated with caspase-3 specific activation of LS422-AuNPs fluorescence. Incorporation of a 3.5 mW NIR laser source into our spectrofluorometer increased the detection sensitivity by an order of magnitude (limit of detection ~0.1 nM of cypate) and significantly decreased the signal noise relative to a xenon lamp. This gain in sensitivity enabled the detection of substrate hydrolysis at a broad range of inhibitor concentrations without photobleaching the cypate dye.

Conclusion

The multifunctional AuNPs demonstrate the use of a non-resonant quenching strategy to design activatable NIR fluorescence molecular probes. The nanoconstruct offers a selective reporting method for detecting activated caspase-3, imaging of cell viability, identifying dying cells, and visualizing the functional status of intracellular enzymes. Performing these tasks with NIR fluorescent probes creates an opportunity to translate the in vitro and cellular analysis of enzymes into in vivo interrogation of their functional status using deep tissue penetrating NIR fluorescence analytical methods.

Role of Alpha-2-Microglobulin in the Treatment of Osteoarthritic Knee Pain: a Brief Review of the Literature

PURPOSE OF REVIEW

Chronic knee pain remains a debilitating condition that remains difficult to manage. The purpose of this review, therefore, is to summarize current understanding of alpha-2-microglobulin in the treatment of osteoarthritic knee pain. Furthermore, we investigate its role in the anti-inflammatory properties of platelet-rich plasma (PRP).

RECENT FINDINGS

Alpha-2-microglobulin, a 720-kD protein complex, is an active protease inhibitor with tremendous anti-inflammatory properties in animal models. A growing body of evidence suggests that this complex is the most instrumental factor for cartilage preservation in PRP injections. As an active component of platelet-rich plasma's anti-inflammatory properties, alpha-2-microglobulin has been shown to be an active inhibitor of joint degeneration, cartilage preservation, and improvement in quality of life for patients with knee osteoarthritis compared with a multitude of other modalities.

Interim guidelines for the assessment and treatment of pain in children with multiple sclerosis

Introduction

Pain in multiple sclerosis (MS) is common, but literature on pain in children with MS remains scarce. Pain has physical, psychological, and social implications in MS, and both comprehensive assessment and interdisciplinary management approaches are needed. We sought to develop an interdisciplinary interim guideline for the assessment and management of pain in children with MS.

Methods and materials

We convened a modified Delphi panel composed of 13 experts in pediatric and adult MS neurology, physiotherapy, pain, patient lived-experience, advanced practice nursing, psychology, physiatry, and MS research. A survey was sent to panelists for anonymous completion. The panel discussed survey themes extracted by the panel chair. The process was repeated twice.

Results

Thirteen assessment and treatment recommendations were produced regarding pain in children with MS.

Discussion

Future studies will assess implementation of these pain assessment and treatment guidelines in the clinical setting.

Reduced Pain and Improved Function Following Short-Term Use of Noninvasive BioWave High Frequency Peripheral Nerve Stimulation for Pain Management

INTRODUCTION

The peripheral nervous system is an increasingly popular target for chronic pain treatment modalities. Noninvasive neuromodulation has shown promise at providing significant chronic pain relief with a much safer side effect profile. This retrospective pilot study is shaped around a noninvasive neuromodulation system over a 2-week treatment timeline.

METHODS

Open-label survey of chronic pain patients recruited from Veteran Affairs, orthopedic, and pain health systems. If a noninvasive neuromodulation system was prescribed the patients were then offered a 2-week follow-up survey. This voluntary survey did not affect their therapy duration or quality. This survey was designed to address similar metrics as smaller noninvasive neuromodulation studies to allow a quality comparison while giving more power with a large population size of 1511 patients. Overall pain scores (including before and after scores), satisfaction level, desire to continue therapy, medication use, effect on functional metrics (mood, sleep, sit, stand, walk, and lift), and activities of daily living (ADL) scores were assessed.

RESULTS

The results demonstrated an overall pain reduction of 46%. All functional metrics were improved throughout with the largest improvements reported in mood and sleep at over 47%. Medication use was reported as decreased or eliminated in 42% of patients. There were no adverse reactions or complications reported over the 1511 patients.

CONCLUSION

This survey is amongst the largest population sizes every studied for noninvasive neuromodulation. Within just 2 weeks patients can see a reduction in overall pain and medication needs. Although survey studies have inherent limitations such as duration and compliance biases with such an overwhelming benefit in every category we believe that noninvasive neuromodulation therapy is a promising, safe, and cost-effective therapy. Future studies should focus on long-term follow-ups and post-therapy pain scores with a placebo group.

Fantastic Four: Age, Spinal Cord Stimulator Waveform, Pain Localization and History of Spine Surgery Influence the Odds of Successful Spinal Cord Stimulator Trial

BACKGROUND

There is a dearth in our understanding of the factors that are predictive of successful spinal cord stimulator (SCS) trials and eventual conversion to permanent implants. Knowledge of these factors is important for appropriate patient selection and treatment optimization.

OBJECTIVES

Although previous studies have explored factors predictive of trial success, few have examined the role of waveform in trial outcomes. This study sought to establish the relationship of neuraxial waveform and related measures to trial outcomes.

STUDY DESIGN

This study used a retrospective chart review design.

METHODS

Data were retrospectively collected on 174 patients undergoing SCS trials upon institutional review board approval of the study protocol. Indications for SCS were: complex regional pain syndrome, failed back surgery syndrome with radicular symptoms, peripheral neuropathy, and axial low back pain. Descriptive statistics and logistic regression analyses were used to assess the association of demographic and clinical variables with SCS trial outcomes.

RESULTS

The study population comprised 56% women, had a median age of 55 (interquartile range [IQR], 44-64), and 32 of 174 (18%) patients failed SCS trials. Individuals with successful trials (>= 50% pain relief) were significantly younger and had a median age of 54 years (IQR, 42-60) compared to those who failed SCS trials (median age 66 years; IQR, 50-76; P = .005). Adjusting for age, gender, number of leads, pain category, and diagnoses: surgical history (odds ratio [OR] = 4.4; 95% confidence interval [CI], 1.3-15.8) and paresthesia-based tonic-stimulation (OR = 10.3; 95% CI, 1.7-62.0), but not burst or high frequency, were significantly associated with successful trials. Of note, the number of leads (whether dual or single), pain duration, characteristics, and category (nociceptive vs neuropathic) were not significant factors. An interaction between surgical spine history and lower extremity pain was significantly associated with a positive trial (P = .005).

LIMITATIONS

This study was limited by its retrospective nature and focus on a patient population at a single major academic medical center.

CONCLUSIONS

Paresthesia-based tonic stimulation, age, and surgical history have significant effects on SCS trials. Prospective and randomized controlled studies may provide deeper insights regarding impact on costs and overall outcomes.IRB Approval #: 2018P002216.

KEY WORDS

Pain duration, pain location, spinal cord stimulator trial, stimulator waveform, surgical history.

Management of incidental lumboiliac hernia during spinal cord stimulator implant: a case report

Lumboiliac or lumbar hernia is a rare defect in the posterolateral abdominal wall that may be inadvertently misidentified and interfere with the implantable pulse generator (IPG) portion of spinal cord stimulator (SCS) implants. We report the case of a 54-year-old Caucasian man with an incidental finding of a lumboiliac hernia in the inferior lumbar triangle of Petit with placement of an IPG in a SCS implant. With the assistance of surgical colleagues, the correct diagnosis was made intraoperatively. We describe the operative repair of the lumboiliac hernia with a synthetic mesh. A new IPG pocket was created above the mesh prior to proceeding with IPG placement. No recurrence of the hernia defect was observed on 2-month follow-up. It is important that pain physicians and neurosurgeons who perform SCS implants are aware of lumboiliac hernias to avoid potential diagnostic or management errors. Lumboiliac hernias should be included on the differential diagnosis of lumbar or flank masses. Confirmation with imaging may be necessary and definitive surgical treatment should be pursued.