Multiligament Knee Reconstruction of the ACL, PLC, and ALL in a Floating Knee: A Case Report

Introduction

Ipsilateral fracture of the femur and tibia, known by the moniker "floating knee," is a serious injury that primarily results from high-energy trauma. Up to 53% of patients with floating knee injuries have concurrent ligamentous injuries, with the anterior cruciate ligament (ACL) as the most commonly affected ligament. Approximately 10% of multi-ligament knee injuries consist of injuries to both the ACL and posterolateral corner (PLC); however, the literature reporting the management of this patient population is sparse, particularly, with a lack of consensus on the timing and protocol of surgical treatment. Well-characterized treatment guidelines are needed for patients with concomitant floating knee and multi-ligament knee injuries.

Case Report

A 26-year-old, previously healthy male involved in a high-speed motor vehicle collision presented with upper and lower extremity, skull, and facial fractures, sacropelvic dissociation, and epidural hematoma. Here we describe a rare instance of a floating knee with a multi-ligament knee injury treated through early reconstruction of the ACL, PLC, and anterolateral ligament following stabilization of long bone fractures. Post-injury day 18, the patient underwent single-stage reconstruction of his multi-ligament knee injury. The timing of this was chosen to allow for capsular scar formation to aid in arthroscopy.

Conclusion

Our surgical algorithm consists of allograft reconstruction using an all-inside ACL technique and a modified anatomical PLC technique. We recommend early (1-3 weeks) surgical treatment of multi-ligament knee injuries for patients without a closed head injury; however, an individualized treatment approach should be sought, considering the severity of ligamentous injuries, pre-injury activity level, extent of soft-tissue damage, and the activity goals of the patient post-injury. In patients with floating knee injuries, the proposed surgical algorithm here may be utilized for successful multi-ligament knee injury reconstruction.

The efficacy of prophylactic vertebroplasty for preventing proximal junctional complications after spinal fusion: a systematic review

BACKGROUND CONTEXT

Prophylactic vertebroplasty (VP) is performed at the upper level of instrumentation during spinal fusion to reduce the risk of proximal junctional kyphosis (PJK), proximal junctional fracture (PJFx), and proximal junctional failure (PJF). This study investigated the effect of VP on patient outcomes after spinal fusion.

PURPOSE

The aim of this systematic review was to evaluate the effect of prophylactic VP on the incidence of PJK in patients with spinal fusion.

STUDY DESIGN/SETTING

Level III, systematic review without meta-analysis.

PATIENT SAMPLE

Adult patients undergoing spinal fusion with VP.

METHODS

A PRISMA-compliant systematic literature review was conducted using PubMed/MEDLINE, Cochrane, and Embase. Included studies were published in English between January 1, 2001, and May 27, 2021, and reported primary data on adult patients undergoing spinal fusion with VP. Studies were excluded for insufficient surgical details; treatment for vertebral compression fracture; and case series and/or reports with <5 patients. The Newcastle-Ottawa Scale was used to assess risk of bias. The primary outcome of interest was PJK. Other outcomes included PJFx, PJF, and adverse events (eg, cement extravasation). Data were expressed as descriptive statistics.

RESULTS

Eight studies with 685 total patients (VP: 293 [42.8%]; No VP: 392 (57.2%)) were included. Five studies were comparative and three were single-arm. PJK incidence was reported in five studies (three comparatives, two single-arm) and ranged from 7.9% to 46.4%; incidence was lower in patients with VP in two of three (66.7%) comparative studies, and equal in one of three (33.3%). PJFx was reported in five studies (four comparatives, one single-arm) and ranged from 0.0% to 39.3%; incidence was lower in the VP group in two of four (50.0%) comparative studies, equal in one of four (25.0%), and higher in one of four (25.0%). PJF was reported in five studies (three comparatives, two single-arm) and ranged from 0.0% to 39.3%; incidence was lower in the VP group in two of three (66.7%) comparative studies and equal in one of three (33.3%). Cement extravasation was reported by four studies and ranged from 0% (0/36) to 48.3% (57/118) in patients with prophylactic VP.

CONCLUSIONS

Evidence on whether prophylactic VP decreases the incidence of PJK, PJFx, and PJF after spinal fusion is inconclusive and conflicting. Additionally, the risk of cement extravasation following prophylactic VP could not be evaluated due to insufficient evidence. Further research is needed to determine whether VP has a significant impact on patient outcomes and risks.

Return to play and performance in the National Basketball Association after undergoing operative or nonoperative treatment for foot fracture

Background

The incidence of distal lower extremity fractures in National Basketball Association (NBA) athletes continues to increase. There is a paucity of data regarding return-to-play (RTP) rates and performance after sustaining foot fractures in these athletes. The purpose of this study is to quantify RTP rates and performance in NBA players after sustaining a foot fracture.

Methods

Sixty-two NBA athletes suffered foot fractures between 2005 and 2021 according to publicly accessible online data. Each athlete was matched to a control player based on age at start of career, age at index injury year, body mass index (BMI), and position played. Performance statistics from 3 seasons prior and 3 seasons following the index injury season were recorded.

Results

We found that players who suffered foot fracture injuries are expected to make a full recovery and reach their previous level of performance within three years. 100% of players treated nonoperatively returned to play; meanwhile only 90% of players who were treated operatively returned to play. This difference is statistically significant.

Conclusion

NBA athletes have a high RTP rate after sustaining a foot fracture. Players may experience an initial decrease in playing time and performance when returning to play, however, these variables were found to return to baseline over time. After three seasons, player statistics returned to baseline in mostly every category, including player efficiency rating (PER). We found that players are expected to make a full recovery and return to their previous level of performance, regardless of whether they were treated operatively or not. Players treated nonoperatively returned to play at a rate of 100% meanwhile those treated operatively returned at a rate of 90%. Therefore, it is our recommendation that players opt for nonoperative treatment when possible.

Bikini Incision vs Longitudinal Incision for Anterior Total Hip Arthroplasty: A Systematic Review

Background

Direct anterior approach total hip arthroplasty (DAA THA) traditionally involves a longitudinal incision, but a bikini incision may improve postoperative scar cosmesis and patient satisfaction while reducing wound complications. This systematic review compares the clinical outcomes and surgical complications in patients undergoing DAA THA via a bikini vs longitudinal incision.

Methods

A Preferred Reporting Items for Systematic Review and Meta-Analyses-compliant search of PubMed, Cochrane, and EMBASE was performed to identify original articles comparing patients undergoing DAA THA via a bikini vs longitudinal incision published from 2010 to 2021. Patient demographic data and postoperative outcomes (scar appearance, patient satisfaction, functional hip scores, and complications) were collected and qualitatively evaluated.

Results

A total of 8 double-armed studies were included, allowing comparison of clinical outcomes of a bikini incision (n = 952) vs a longitudinal incision (n = 1361). Three out of 4 (75.0%) studies comparing postoperative scar appearance and patient satisfaction reported improvements following bikini incision, while 1 study reported comparable results between incision types. Postoperative hip function was similar between incision types in 3 of 4 (75.0%) studies comparing this outcome. Lateral femoral cutaneous nerve injury was the most frequently reported complication following anterior THA, but rates were low overall, and most injuries resolved.

Conclusions

Bikini incision appears to be a safe alternative to the traditional longitudinal incision, with similar functional hip outcomes and potentially improved cosmesis and patient satisfaction while reducing wound complications. Current evidence suggests an elevated risk of lateral femoral cutaneous nerve injury with bikini incision, but this needs to be confirmed in further prospective randomized studies.

Glenoid bone augmentation: a contemporary and comprehensive systematic review of open procedures

Introduction

There is a trend towards arthroscopically treating shoulder instability with glenoid deficiency. Despite this, there remains the option for treatment through an open technique. Multiple bone augmentation options are available for recurrent anterior shoulder instability.

Objective

To provide a systematic review of recent studies for recurrent anterior shoulder instability necessitating glenoid bone augmentation specifically through open procedures using coracoid bone or free bone blocks [iliac crest bone autograft/allograft or distal tibia allograft (DTA)].

Methods

PubMed, Cochrane, EMBASE, and Google Scholar were searched for studies reporting open glenoid bone augmentation procedures with iliac crest, tibia, or coracoid bones within 10 years. Extracted data included study/patient characteristics, techniques, prior surgeries, prior dislocations, radiographic findings, range of motion (ROM), recurrent instability, patient-reported outcomes, and complications.

Results

92 met inclusion criteria (5693 total patients). Six were studies of iliac crest bone, four of DTA, and 84 using the coracoid bone. 29 studies measured postoperative arthritis showing no development or mild arthritis. 26 studies reported postoperative graft position. 62 studies reported ROM noting decline in internal/external rotation. 87 studies measured postoperative instability with low rates. Rowe Scores with noted improvement across 31/59 (52.5%) studies were seen. Common post operative complications included infection, hematoma, graft fracture, nerve injury, pain, and screw-related irritation.

Conclusion

Despite a trend towards arthroscopic management of recurrent anterior shoulder instability with glenoid deficiency, open procedures continue to provide satisfactory outcomes. Additionally, studies have demonstrated safe and efficacious use of free bone block graft options in the primary and revision setting.

Coracoclavicular Ligament Reconstruction Using TightRope for Delayed Grade III Acromioclavicular Joint Injury After Ipsilateral Diaphyseal Clavicle Fracture Fixation: Surgical Technique and Review of Current Literature

Athletes commonly sustain high-energy direct impact injuries to the shoulder, with acromioclavicular joint (ACJ) injuries accounting for over half. Ipsilateral ACJ injury and diaphyseal clavicle fracture occur nearly 7% of the time. There is limited literature offering treatment suggestions for this unique injury pattern and limited evidence providing guidance to suggest which injury patterns should be treated operatively or nonoperatively. Here, we present successful treatment of a high-level athlete utilizing a Knotless TightRope XP placed through a superior clavicle plate with successful return to full activity at 6 months postoperation. The TightRope technique offers the ability to augment through a preexisting superior clavicular plate in a low-profile manner and promote easy suture tensioning to obtain and maintain reduction of the injured ACJ.

Does shoulder stability differ with or without subscapularis repair after primary reverse total shoulder arthroplasty? A systematic review

The use of reverse total shoulder arthroplasty (RTSA) has expanded from its original indication as a rotator cuff arthropathy treatment to include a large variety of pathologies. A frequently reported complication with this surgery is postoperative shoulder instability with reported incidence varying widely from 2.3 to 38%. The etiology for this instability is broad and includes prosthesis design, mechanical impingement, surgical technique, and axillary/deltoid function. A PROSPERO-registered systematic review was performed utilizing PRISMA guidelines using Cochrane, PUBMED, Embase, and Eline. Of the 1442 studies initially identified, 7 studies met all inclusion criteria, all of which were level III or IV evidence. All 7 studies evaluated postoperative instability, but no study reported a statistically significant difference in instability rates between the groups. Dislocations occurred in 5 patients (5/679, 0.7%) with subscapularis repair and 8 patients (8/527, 1.5%) without repair. A nonsignificant difference in the risk of instability for surgeries with repair compared to surgeries without repair was found (overall risk difference: 0.01, random effects 95% confidence interval: -0.00 to 0.02, P = .11). This review suggests no difference in postoperative shoulder instability rates between patients that underwent primary RTSA with or without subsequent repair of the subscapularis tendon. Interestingly, one study comparing implants with a medialized or nonlateralized implant showed a significantly increased rate of dislocation with the medialized group compared to the lateralized group. When these groups were then stratified based on subscapularis repair status, there was no increased risk with a nonrepaired tendon. This study suggests that implant design may have more influence on the stability of RTSA than subscapularis status. However, overall, there does appear to be a trend suggesting improved postoperative clinical outcomes and active range of motion for patients with a subscapularis repair vs. without a repair. Further research is needed to better elucidate the ideal combination of surgical technique and implant design to minimize postoperative glenohumeral joint instability while optimizing postoperative clinical outcomes and range of motion after primary RTSA.

Outcomes following balloon tibioplasty versus conventional osteosynthesis techniques for Schatzker type III tibial plateau fractures: a systematic review

Introduction

Schatzker type III fractures of the tibial plateau require elevation of the depressed portions to regain articular congruity. Balloon tibioplasty has been used as an alternative to conventional metal instruments for elevation of the lateral tibial plateau. This study compared functional outcomes following balloon tibioplasty or conventional osteosynthesis techniques in patients with type III fractures of the tibial plateau.

Materials and methods

A systematic literature search was performed using PubMed, EMBASE, and Cochrane Library to identify studies published through March 29, 2021, pertaining to balloon tibioplasty or conventional osteosynthesis techniques for type III fractures. Non-human studies, opinion or editorial pieces, systematic reviews, case series (< 5 patients), and articles published in a non-English language were excluded. Primary outcomes were Rasmussen clinical score, range of motion, and Knee Society Score (KSS). A Joanna Briggs Institute (JBI) risk of bias assessment was performed for all studies.

Results

A total of 95 studies were identified, with 10 studies (and 132 total patients) meeting inclusion criteria: 1 study focused on balloon tibioplasty, 8 studies reported outcomes following conventional osteosynthesis, and 1 study compared outcomes of the two techniques. Mean follow-up times varied widely, from 4 to 76.3 months. Where reported, balloon tibioplasty resulted in good to excellent functional outcomes as indicated by Rasmussen clinical scores (mean 28.3 in a case series; mean 28.9 in a randomized controlled trial) and range of motion (≥ 140° in both studies) 1–2 years following surgery. KSS was not reported consistently enough for comparison. Studies ranged from low to high risk of bias according to the JBI assessment.

Conclusions

Balloon tibioplasty can lead to excellent functional outcomes in patients with depression fractures of the lateral tibial plateau. More research is needed to directly compare outcomes following treatment with balloon tibioplasty or conventional osteosynthesis techniques.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-02973-1.

An Assessment of the Impact of SARS-CoV-2 on a Level 1 Trauma Center Including Subgroup Analysis of Orthopedic Injuries and Mechanism of Injury

Background and objective

There is a paucity of medical literature describing the preparedness of hospital institutions to withstand the population effects of a pandemic. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19), has had a global impact on all facets of medicine, which has ultimately affected the medical community in a significant manner. Furthermore, there is a scarcity of research regarding the effects of COVID-19 on trauma and acute care surgery injury and admission rates. We conducted this study to examine the effects of the COVID-19 pandemic on both pediatric and adult trauma admissions, injury types, and mechanisms of injury.

Materials and methods

Data from the Trauma Registry was extracted for all adult (>15 years) and pediatric (<15 years) patients who consulted trauma surgery, acute care surgery, or orthopedic surgery at our center in the year immediately prior to the pandemic (March 1, 2019-February 29, 2020) and during the COVID-19 pandemic (March 1, 2020-February 28, 2021). Patient demographics, cause of injury, injury type and mechanism, and procedures performed were recorded.

Results

We documented a 4.2% increase in adult encounters compared to the preceding year. There was a significant difference in the distribution of mechanism of injury of adult patients between the two time periods, with the most changes seen in motor-vehicle auto, gunshot, and other vehicle injuries. However, no significant difference was seen in trauma type or intent (assault, self-inflicted, unintentional). Pediatric encounters increased by 6.4% during the COVID-19 pandemic compared to the pre-COVID-19 period. Overall, there was no detectable association between the distribution of encounters by the mechanism of injury and the time period for pediatric encounters.

Conclusion

This retrospective review of trauma encounters through both pre-COVID-19 and COVID-19 periods outlines the differences in factors such as demographics, injury mechanisms, and injury types between the two time periods. Overall, we expected a decrease in orthopedic-related trauma admissions during the COVID-19 pandemic; however, there was actually an increase of 4.1% in adult encounters and that of 6.4% in pediatric encounters. Our study lays out possible trends in injury patterns that can be correlated with the COVID-19 pandemic and the lockdown period. This information is useful for the healthcare system in that it demonstrates that resources should not be cut down or removed from surgical specialties. At level I facilities, resources need to be allocated for and continued to be provided to emergency rooms and operative services, including supplies and staffing. These departments need to be well-equipped to handle an increased number of trauma patients.

Osteoid Osteoma of the Coracoid Process Presenting as Adhesive Capsulitis in a 10-Year-Old Male: A Case Report

A 10-year-old male presented with symptoms in his right shoulder indicative of adhesive capsulitis. Radiographic films did not demonstrate any osseous abnormalities. Magnetic resonance imaging demonstrated the presence of an eccentric lesion within the coracoid process consistent with an osteoid osteoma. Six months after surgical removal the patient is back to full activities. For the pediatric population, surgeons must always consider diagnoses that could alter a patient's growth or result in long-term disability. In particular, an atypical presentation of musculoskeletal disease in a pediatric patient presenting with a disease that typically is seen in the older population warrants further workup.

Tranexamic acid dosing strategies and blood loss reduction in multilevel spine surgery: A systematic review and network meta-analysis

•

Tranexamic acid (TXA) is used to reduce blood loss during spine surgery

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It is unclear whether there is an optimal TXA dosing regimen (e.g., how many mg/hour?)

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In this network meta-analysis, 7 studies used 4 different TXA dosing regimens in 441 patients

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TXA was associated with reduced blood loss volume, but no dosing regimen was clearly superior

•

Additional trials comparing TXA dosing regimens and administration routes are needed

Background

For adults undergoing complex, multilevel spinal surgery, tranexamic acid (TXA) is an antifibrinolytic agent used to reduce blood loss. The optimal dosing of intravenous TXA remains unclear. This systematic review and meta-analysis compare various dosing regimens of intravenous TXA used in patients undergoing multilevel spine surgery (≥2 levels).

Methods

PubMed, Cochrane, and EMBASE databases were searched for English language studies published January 2001 through May 2021 reporting use of TXA versus placebo for multilevel spine surgery. Primary outcomes of interest were intraoperative blood loss volume (BLV) and total BLV. A separate random effects model was fit for each outcome measure. Effect sizes were calculated as pooled mean differences (Diff) with corresponding 95% confidence intervals (CIs). Random effects network meta-analyses assessed whether the specific TXA dosing regimen influenced BLV.

Results

Seven studies with 441 patients were included for meta-analysis. Four different TXA dosing regimens were found: 1) 10 mg/kg + 1 mg/kg/h, 2) 10 mg/kg + 2 mg/kg/h, 3) 15 mg/kg, 4) 15 mg/kg + 1 mg/kg/h. Compared to placebo, patients treated with TXA had reduced intraoperative BLV (Diff = -185.0 ml; 95% CI: -302.1, -67.9) and reduced total BLV (Diff = -439.0 ml; 95% CI: -838.5, -39.6). No significant differences in intraoperative BLV among any of the TXA treatment groups was found. Patients given a TXA dose of 15 mg/kg + 1 mg/kg/h had significantly reduced total BLV in comparison to both placebo (Diff = -823.1 ml; 95% CI: -1249.8, -396.4) and a dose of 15 mg/kg (Diff = -581.2; 95% CI: -1106.8, -55.7).

Conclusions

This study found that intravenous TXA is associated with reduced intraoperative and total BLV, but it remains unclear whether there is an optimal TXA dose. Additional trials directly comparing different TXA regimens and administration routes are needed.

A text message intervention to support women's physical and mental health after breast cancer treatments (EMPOWER-SMS): a randomised controlled trial protocol

Background

Breast cancer is the most common cancer diagnosed in women worldwide. In developed countries, 80–90% of women will survive five years after diagnosis but the transition from hospital-based care to health self-management and self-efficacy can be difficult. Text messaging programs offer a simple and proven way to provide support to people with chronic diseases. This study aims to test the effectiveness of a text message support program at improving women’s health self-efficacy, and physical and mental health outcomes after breast cancer treatments compared to usual care at 6-months and to understand the barriers and enablers to widespread implementation.

Methods

Single-blind randomised control trial (RCT; N = 160) comparing a text message support intervention to usual care in women with breast cancer (recruited from a large tertiary referral hospital in Sydney, Australia). The intervention group will receive a six-month text message support program, which consists of semi-personalised, supportive, lifestyle-focused text messages (4 messages/week) in addition to usual care. The control group will receive usual care without the text message program. Outcomes will be assessed at 6-months. The primary outcome is change in self-efficacy for managing chronic disease. Secondary outcomes include change in clinical outcomes (body mass index), lifestyle outcomes (physical activity levels, dietary behaviours), mood (depression and anxiety scales), quality of life, satisfaction with, and usefulness of the intervention. Analyses will be performed on the principle of intention-to-treat to examine differences between intervention and control groups.

Discussion

This study will test if a scalable and cost-effective text-messaging intervention is effective at improving women’s health self-efficacy, as well as physical and mental health outcomes. Moreover, this study will provide essential preliminary data to bolster a large multicentre RCT to helpsupport breast cancer survivors throughout recovery and beyond.

Trial registration

Australia New Zealand Clinical Trials Registry (ANZCTR) number ACTRN12618002020268, 17 December 2018

Stromalized microreactor supports murine hematopoietic progenitor enrichment

There is an emerging need to process, expand, and even genetically engineer hematopoietic stem and progenitor cells (HSPCs) prior to administration for blood reconstitution therapy. A closed-system and automated solution for ex vivo HSC processing can improve adoption and standardize processing techniques. Here, we report a recirculating flow bioreactor where HSCs are stabilized and enriched for short-term processing by indirect fibroblast feeder coculture. Mouse 3 T3 fibroblasts were seeded on the extraluminal membrane surface of a hollow fiber micro-bioreactor and were found to support HSPC cell number compared to unsupported BMCs. CFSE analysis indicates that 3 T3-support was essential for the enhanced intrinsic cell cycling of HSPCs. This enhanced support was specific to the HSPC population with little to no effect seen with the Lineage^positive and Lineage^negative cells. Together, these data suggest that stromal-seeded hollow fiber micro-reactors represent a platform to screening various conditions that support the expansion and bioprocessing of HSPCs ex vivo.

Whole-exome sequencing of the BDR cohort: evidence to support the role of the PILRA gene in Alzheimer's disease

AIM

Late-onset Alzheimer's disease (LOAD) accounts for 95% of all Alzheimer's cases and is genetically complex in nature. Overlapping clinical and neuropathological features between AD, FTD and Parkinson's disease highlight the potential role of genetic pleiotropy across diseases. Recent genome-wide association studies (GWASs) have uncovered 20 new loci for AD risk; however, these exhibit small effect sizes. Using NGS, here we perform association analyses using exome-wide and candidate-gene-driven approaches.

METHODS

Whole-exome sequencing was performed on 132 AD cases and 53 control samples. Exome-wide single-variant association and gene burden tests were performed for 76 640 nonsingleton variants. Samples were also screened for known causative mutations in familial genes in AD and other dementias. Single-variant association and burden analysis was also carried out on variants in known AD and other neurological dementia genes.

RESULTS

Tentative single-variant and burden associations were seen in several genes with kinase and protease activity. Exome-wide burden analysis also revealed significant burden of variants in PILRA (P = 3.4 × 10^-5 ), which has previously been linked to AD via GWAS, hit ZCWPW1. Screening for causative mutations in familial AD and other dementia genes revealed no pathogenic variants. Variants identified in ABCA7, SLC24A4, CD33 and LRRK2 were nominally associated with disease (P < 0.05) but did not withstand correction for multiple testing. APOE (P = 0.02) and CLU (P = 0.04) variants showed significant burden on AD.

CONCLUSIONS

In addition, polygenic risk scores (PRS) were able to distinguish between cases and controls with 83.8% accuracy using 3268 variants, sex, age at death and APOE ε4 and ε2 status as predictors.

Image-Based Profiling of Patient-Derived Pancreatic Tumor-Stromal Cell Interactions Within a Micropatterned Tumor Model

Pancreatic cancer is one of the most aggressive cancers with a 5-year patient survival rate of 8.2% and limited availability of therapeutic agents to target metastatic disease. Pancreatic cancer is characterized by a dense stromal cell population with unknown contribution to the progression or suppression of tumor growth. In this study, we describe a microengineered tumor stromal assay of patient-derived pancreatic cancer cells to study the heterotypic interactions of patient pancreatic cancer cells with different types of stromal fibroblasts under basal and drug-treated conditions. The population dynamics of tumor cells in terms of migration and viability were visualized as a functional end point. Coculture with cancer-associated fibroblasts increased the migration of cancer cells when compared to dermal fibroblasts. Finally, we imaged the response of a bromodomain and extraterminal inhibitor on the viability of pancreatic cancer clusters surrounding by stroma in microengineered tumor stromal assay. We visualized a codynamic reduction in both cancer and stromal cells with bromodomain and extraterminal treatment compared to the dimethyl sulfoxide-treated group. This study demonstrates the ability to engineer tumor–stromal assays with patient-derived cells, study the role of diverse types of stromal cells on cancer progression, and precisely visualize a coculture during the screening of therapeutic compounds.

Artificial T Cell Mimetics to Combat Melanoma Tumor Growth

Despite recent breakthroughs in melanoma treatment with anti-PD-1 immunotherapy, innovative approaches are needed to improve off-target effects. In this study, we report a T cell mimetic microparticle delivery of soluble PD1 aiming at providing a carrier substrate for future combinatorial and targeting efforts. Microparticles of sizes varying from (5 μm to-7 μm) were conjugated with soluble mouse or human PD-1 through nearly irreversible binding between streptavidin and biotin. PD-1 conjugated microparticles (PDMPs) suppressed 3-dimensional tumor growth of human A375 and mouse B16-F10 melanoma cells compared to control microparticles conjugated with the Fc portion of human IgG1 (IgG1MPs). This can be attributed to competitive inhibition by PDMPs on a melanoma cell-intrinsic PD-1/PD-L1 pathway. A single, local administration of mPDMPs in a B16-F10 mouse melanoma model inhibited tumor growth significantly compared to control IgMPs at the same dose. CD45+ immune cells were found to infiltrate tumors treated with mPDMPs as a mechanism for tumor control. These results collectively suggest that PDMPs can target the melanoma cell-intrinsic PD-1/PD-L1 pathway and that these artificial T cell mimetics can be the scaffold for further improvements in anti-tumor immunotherapy.

Orthogonal potency analysis of mesenchymal stromal cell function during ex vivo expansion

Adult bone marrow mesenchymal stromal cells (MSCs) have cross-functional, intrinsic potency that is of therapeutic interest. Their ability to regenerate bone, fat, and cartilage, modulate the immune system, and nurture the growth and function of other bone marrow hematopoietic stem/progenitor cells have all been evaluated by transplant applications of MSCs. These applications require the isolation and expansion scaled cell production. To investigate biophysical properties of MSCs that can be feasibly utilized as predictors of bioactivity during biomanufacturing, we used a low-density seeding model to drive MSCs into proliferative stress and exhibit the hallmark characteristics of in vitro aging. A low-density seeding method was used to generate MSCs from passages 1-7 to simulate serial expansion of these cells to maximize yield from a single donor. MSCs were subjected to three bioactivity assays in parallel to ascertain whether patterns in MSC age, size, and shape were associated with the outcomes of the potency assays. MSC age was found to be a predictor of adipogenesis, while cell and nuclear shape was strongly associated to hematopoietic-supportive potency. Together, these data evaluate morphological changes associated with cell potency and highlight new strategies for purification or alternatives to assessing MSC quality.

An engineered biomarker system to monitor and modulate immune clearance of cell therapies

BACKGROUND AIMS

Cell transplants offer a new opportunity to deliver therapies with novel and complex mechanisms of action. Understanding the pharmacology of cell transplants is important to deliver this new therapy effectively. Currently, however, there are limited techniques to easily track cells after intravenous administration due to the dispersion of the graft throughout the entire body.

METHODS

We herein developed an engineered cell system that secretes a luciferase enzyme to sensitively detect cell transplants independent of their locale by a simple blood test. We specifically studied a unique feature of cell transplant pharmacology-namely, immune clearance-using mesenchymal stromal cells (MSCs) as a proof-of-concept cell therapy. MSCs are a clinically relevant cell therapy that has been explored in several disease indications due to their innate properties of altering an immune response.

RESULTS

Using this engineered reporter, we observed specific sensitivity of cell therapy exposure to the preparation of cells, cytolysis of MSCs in an allogeneic setting and a NK cell-mediated destruction of MSCs in an autologous setting.

CONCLUSIONS

Our cellular tracking method has broader implications at large for assessing in vivo kinetics of various other cell therapies.

Genetics of Hereditary Ataxia in Scottish Terriers

BACKGROUND

Scottish Terriers have a high incidence of juvenile onset hereditary ataxia primarily affecting the Purkinje neuron of the cerebellar cortex and causing slowly progressive cerebellar dysfunction.

OBJECTIVE

To identify chromosomal regions associated with hereditary ataxia in Scottish Terriers.

ANIMALS

One hundred and fifty-three Scottish Terriers were recruited through the Scottish Terrier Club of America.

MATERIALS AND METHODS

Prospective study. Dogs were classified as affected if they had slowly progressive cerebellar signs. When possible, magnetic resonance imaging and histopathological evaluation of the brain were completed as diagnostic aids. To identify genomic regions connected with the disease, genome-wide mapping was performed using both linkage- and association-based approaches. Pedigree evaluation and homozygosity mapping were also performed to examine mode of inheritance and to investigate the region of interest, respectively.

RESULTS

Linkage and genome-wide association studies in a cohort of Scottish Terriers both identified a region on CFA X strongly associated with the disease trait. Homozygosity mapping revealed a 4 Mb region of interest. Pedigree evaluation failed to identify the possible mode of inheritance due to the lack of complete litter information.

CONCLUSION AND CLINICAL IMPORTANCE

This finding suggests that further genetic investigation of the potential region of interest on CFA X should be considered in order to identify the causal mutation as well as develop a genetic test to eliminate the disease from this breed.

Intact soluble P-glycoprotein is secreted by sinonasal epithelial cells

BACKGROUND

P-glycoprotein (P-gp) is a 170 kDa transmembrane efflux pump, which is upregulated in chronic rhinosinusitis. Studies of leukemia demonstrated that P-gp may also be secreted in an intact soluble form. The purpose of this study was to explore whether sinonasal epithelial cells were capable of secreting soluble P-gp and whether P-gp has any functional role.

METHODS

Soluble and cytoplasmic P-gp were quantified in vehicle and lipopolysaccharide exposed cultures by enzyme-linked immunosorbent assay. The molecular weight of the soluble P-gp was determined by Western blot. Naive cultures were exposed to recombinant human P-gp at 0-2000 ng/mL. The degree of membranous interpolation was determined by quantitative fluorescent immunocytochemistry and function was determined by a calcein acetoxymethyl ester assay.

RESULTS

Soluble P-gp was secreted intact at 170 kDa. Mean (standard deviation) secretion was detected within vehicle wells at 55.43 ± 26.26 ng/mL, which significantly increased to 333.27 ± 305.98 ng/mL (p < 0.001) after lipopolysaccharide stimulation. Soluble P-gp strongly and significantly correlated with cytoplasmic P-gp (r = 0.57, p = 0.000001). Exposure to 2000 ng/mL of recombinant P-gp significantly increased corrected total cell fluorescence (1.34 ± 1.85) relative to vehicle control 0.29 ± 0.26 (p = 0.01) and significantly reduced calcein acetoxymethyl ester fluorescence (82.03 ± 43.69) relative to 100 ng/mL recombinant P-gp exposed cells (123.11 ± 42.16, p = 0.001).

CONCLUSION

Cultured sinonasal epithelial cells were able to both secrete intact P-gp and could functionally interpolate soluble P-gp into their cell membrane. These in vitro findings indicated that soluble P-gp may be present in nasal mucus as a biomarker and could participate in the maintenance of P-gp overexpression in chronic rhinosinusitis and associated inflammation.

Delta-9-tetrahydrocannabinol (THC) affects forelimb motor map expression but has little effect on skilled and unskilled behavior

It has previously been shown in rats that acute administration of delta-9-tetrahydrocannabinol (THC) exerts a dose-dependent effect on simple locomotor activity, with low doses of THC causing hyper-locomotion and high doses causing hypo-locomotion. However the effect of acute THC administration on cortical movement representations (motor maps) and skilled learned movements is completely unknown. It is important to determine the effects of THC on motor maps and skilled learned behaviors because behaviors like driving place people at a heightened risk. Three doses of THC were used in the current study: 0.2mg/kg, 1.0mg/kg and 2.5mg/kg representing the approximate range of the low to high levels of available THC one would consume from recreational use of cannabis. Acute peripheral administration of THC to drug naïve rats resulted in dose-dependent alterations in motor map expression using high resolution short duration intracortical microstimulation (SD-ICMS). THC at 0.2mg/kg decreased movement thresholds and increased motor map size, while 1.0mg/kg had the opposite effect, and 2.5mg/kg had an even more dramatic effect. Deriving complex movement maps using long duration (LD)-ICMS at 1.0mg/kg resulted in fewer complex movements. Dosages of 1.0mg/kg and 2.5mg/kg THC reduced the number of reach attempts but did not affect percentage of success or the kinetics of reaching on the single pellet skilled reaching task. Rats that received 2.5mg/kg THC did show an increase in latency of forelimb removal on the bar task, while dose-dependent effects of THC on unskilled locomotor activity using the rotorod and horizontal ladder tasks were not observed. Rats may be employing compensatory strategies after receiving THC, which may account for the robust changes in motor map expression but moderate effects on behavior.

Role of students' context in predicting academic performance at a medical school: a retrospective cohort study

OBJECTIVES

This study examines associations between medical students' background characteristics (postcode-based measures of disadvantage, high school attended, sociodemographic characteristics), and academic achievement at a Russell Group University.

DESIGN

Retrospective cohort analysis.

SETTING

Applicants accepted at the University of Liverpool medical school between 2004 and 2006, finalising their studies between 2010 and 2011.

PARTICIPANTS

571 students (with an English home postcode) registered on the full-time Medicine and Surgery programme, who successfully completed their medical degree.

MAIN OUTCOME MEASURES

Final average at year 4 of the medical programme (represented as a percentage).

RESULTS

Entry grades were positively associated with final attainment (p<0.001). Students from high-performing schools entered university with higher qualifications than students from low-performing schools (p<0.001), though these differences did not persist at university. Comprehensive school students entered university with higher grades than independent school students (p<0.01), and attained higher averages at university, though differences were not significant after controlling for multiple effects. Associations between school type and achievement differed between sexes. Females attained higher averages than males at university. Significant academic differences were observed between ethnic groups at entry level and university. Neither of the postcode-based measures of disadvantage predicted significant differences in attainment at school or university.

CONCLUSIONS

The findings of this study suggest that educational attainment at school is a good, albeit imperfect, predictor of academic attainment at medical school. Most attainment differences observed between students either decreased or disappeared during university. Unlike previous studies, independent school students did not enter university with the highest grades, but achieved the lowest attainment at university. Such variations depict how patterns may differ between subjects and higher-education institutions. Findings advocate for further evidence to help guide the implementation of changes in admissions processes and widen participation at medical schools fairly.

Gene transcripts associated with muscle strength: a CHARGE meta-analysis of 7,781 persons

Lower muscle strength in midlife predicts disability and mortality in later life. Blood-borne factors, including growth differentiation factor 11 (GDF11), have been linked to muscle regeneration in animal models. We aimed to identify gene transcripts associated with muscle strength in adults. Meta-analysis of whole blood gene expression (overall 17,534 unique genes measured by microarray) and hand-grip strength in four independent cohorts (n = 7,781, ages: 20-104 yr, weighted mean = 56), adjusted for age, sex, height, weight, and leukocyte subtypes. Separate analyses were performed in subsets (older/younger than 60, men/women). Expression levels of 221 genes were associated with strength after adjustment for cofactors and for multiple statistical testing, including ALAS2 (rate-limiting enzyme in heme synthesis), PRF1 (perforin, a cytotoxic protein associated with inflammation), IGF1R, and IGF2BP2 (both insulin like growth factor related). We identified statistical enrichment for hemoglobin biosynthesis, innate immune activation, and the stress response. Ten genes were associated only in younger individuals, four in men only and one in women only. For example, PIK3R2 (a negative regulator of PI3K/AKT growth pathway) was negatively associated with muscle strength in younger (<60 yr) individuals but not older (≥ 60 yr). We also show that 115 genes (52%) have not previously been linked to muscle in NCBI PubMed abstracts. This first large-scale transcriptome study of muscle strength in human adults confirmed associations with known pathways and provides new evidence for over half of the genes identified. There may be age- and sex-specific gene expression signatures in blood for muscle strength.

P-glycoprotein regulates Staphylococcus aureus enterotoxin B-stimulated interleukin-5 and thymic stromal lymphopoietin secretion in organotypic mucosal explants

BACKGROUND

T-helper 2 (Th2) inflammation is a hallmark of chronic rhinosinusitis with nasal polyps (CRSwNP) although the pathogenesis is poorly understood. P-glycoprotein (permeability glycoprotein, P-gp) is an efflux pump that is capable of regulating cytokine transport and is expressed within sinonasal mucosa. The purpose of this study was to examine if the oversecretion of interleukin 5 (IL-5) and thymic stromal lymphopoietin (TSLP) in CRSwNP could be explained through P-gp-mediated secretory pathways.

METHODS

Fifteen ethmoid mucosal explants were harvested from patients with CRS (n = 10) and CRSwNP (n = 10) and stimulated with Staphylococcus aureus enterotoxin B (SEB). P-gp was inhibited using zosuquidar trihydrochloride (herein Zosuquidar). P-gp expression was measured using real-time polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). IL-5, IL-8, and TSLP secretion were quantified using ELISA.

RESULTS

P-gp protein was overexpressed in CRSwNP (28.32 ± 25.94 ng/mL per mg explant) as compared to CRS (10.74 ± 8.61; p = 0.01, 2-tailed Mann-Whitney U test). There was no difference in messenger RNA (mRNA) expression. SEB induced a significant increase in IL-5 and TSLP but not IL-8 secretion relative to control in the CRSwNP explants only. Subsequent P-gp inhibition significantly reduced IL-5 and TSLP secretion (p = 0.04 for both, 2-tailed Student t test) to control levels. The concentration of IL-5 and TSLP secretion were strongly and significantly correlated to the concentration of P-gp within the same explant (IL-5: r = 0.791, p = 0.001; TSLP: r = 0.687, p = 0.003; 2-tailed Spearman's rank-order correlation).

CONCLUSION

P-gp protein is expressed at higher concentrations in CRSwNP as compared to CRS. This overexpression directly contributes to the relative hypersecretion of IL-5 and TSLP. These findings suggest a novel mechanism for Th2 skewing in CRSwNP.

Itraconazole and clarithromycin inhibit P-glycoprotein activity in primary human sinonasal epithelial cells

BACKGROUND

Itraconazole and clarithromycin are clinically effective in the treatment of chronic rhinosinusitis (CRS) through incompletely understood anti-inflammatory properties. P-glycoprotein (P-gp) is overexpressed in CRS and inhibition results in decreased inflammatory cytokine secretion. Both itraconazole and clarithromycin have also been shown to have P-gp inhibitory properties in other tissues, suggesting a novel explanation for their immunomodulatory effects in CRS. The purpose of this study is to therefore confirm whether these drugs are capable of inhibiting P-gp specifically in sinonasal epithelial cells.

METHODS

This was an institutional review board (IRB)-approved study in which primary sinonasal epithelial cells were cultured in 96-well plates. A Calcein AM assay was used to quantify P-gp inhibition as determined by an increase in intracellular fluorescence. A dose-response curve was generated for itraconazole and clarithromycin (maximal concentration 100 μM) and compared to that of Zosuquidar, a highly specific known P-gp inhibitor. Results were compared using a Student t test with a significance defined as p < 0.05.

RESULTS

Both itraconazole and clarithromycin demonstrated a dose-response curve for P-gp inhibition similar to that of Zosuquidar. The respective maximal inhibitory concentrations of Zosuquidar, itraconazole, and clarithromycin prior to induction of cytotoxicity were 0.31, 3.13, and 1.56 μM, respectively, as demonstrated by a statistically significant increase in total intracellular fluorescence (p < 0.05 in all groups).

CONCLUSION

Both itraconazole and clarithromycin are capable of inhibiting sinonasal epithelial cell associated P-gp. The anti-inflammatory effects of these agents in CRS may be attributable, in part, to their heretofore unrecognized P-gp modulatory properties.

Verapamil modulates interleukin-5 and interleukin-6 secretion in organotypic human sinonasal polyp explants

BACKGROUND

Verapamil is an L-type calcium channel blocker (CCB) that has been shown to have immunomodulatory properties in a variety of tissues. The goal of this study was determine whether verapamil is capable of regulating cytokine secretion in sinonasal polyps and to compare this effect to dexamethasone, an established immunosuppressive corticosteroid.

METHODS

This was an institutional review board (IRB)-approved study in sinonasal polyp explants derived from 8 patients with chronic rhinosinusitis with nasal polyps (CRSwNP). Polyps were incubated with dexamethasone or verapamil for 24 hours followed by an additional 24 hours with Staphylococcal enterotoxin B (SEB). Concentrations of secreted cytokines over each exposure period were determined by enzyme-linked immunosorbent assay (ELISA) and are expressed as a percent. Results were compared using a 2-tailed Student t test.

RESULTS

The percent of SEB-stimulated interleukin-5 (IL-5) secretion (mean ± standard deviation [SD], 339.94% ± 315.48%) between the second and first treatment periods was significantly reduced following exposure to dexamethasone (74.08% ± 26.77%, p < 0.05) and verapamil (119.99% ± 69.32%, p < 0.05). The percent of SEB-stimulated IL-6 secretion (217.53% ± 89.51%) was also significantly reduced following exposure to verapamil (148.82% ± 79.15%, p < 0.05) but not dexamethasone (148.86% ± 145.24%). Finally, the percent of SEB-stimulated thymic stromal lymphopoietin (TSLP) secretion (37.86% ± 18.88%) demonstrated a nonsignificant trend toward reduction with both dexamethasone (31.15% ± 35.28%) and verapamil (20.14% ± 12.10%).

CONCLUSION

Although the mechanism has yet to be fully understood, L-type CCBs are capable of reducing inflammation in multiple tissues. Verapamil was specifically found to reduce airway goblet cell hyperplasia and eosinophilic infiltration in a murine asthma model. Our data support these findings suggesting that verapamil can modulate T-helper cell type 2 (Th2)-associated cytokine secretion in sinonasal polyp explants. This data points to a possible therapeutic role for CCBs in the management of CRSwNP.

Clinical features of patients with blepharospasm: a report of 240 patients

BACKGROUND AND PURPOSE

To characterize patients with benign essential blepharospasm (BEB) by diagnosis, environmental risk factors, and family history.

METHODS

Two hundred and forty patients with BEB were evaluated through a clinical examination and questionnaire. The questionnaire reviewed personal medical history, demographic factors, risk factors for the development of blepharospasm and family history of dystonia and other neurological conditions.

RESULTS

Benign essential blepharospasm was more commonly found in women (2.8:1) and 93% of the patients were Caucasian. Fifty percent had pure BEB, 31% had BEB/Meige's syndrome, and 4% had BEB and eyelid opening apraxia (+/- Meige's syndrome). A minority of patients reported preceding photophobia (25%) or other eye conditions (22%). The majority were non-smokers, had no exposure to anti-emetic or antipsychotic agents, had a normal birth history, and had no history of head trauma. Seventy-two percent did report a stressful event immediately prior to the development of symptoms. Treatments reported included botulinum toxin (BoNT), oral medications, surgical procedures, and acupuncture. Thirty-two percent of patients reported a family history of focal dystonia, and BEB was the most commonly reported.

CONCLUSION

This study confirms previous reports of usual age, sex, caffeine and tobacco use, and family history in patients with blepharospasm. New findings include a report on occupation, lower reports of preceding eye conditions and photophobia, and higher reported stressful events. Further, this study shows a change in treatment with an increase in BoNT use and decrease in surgical procedures.

Genomic biomarkers and cellular pathways of ischemic stroke by RNA gene expression profiling

OBJECTIVE

The objective of this study was to provide insight into the molecular mechanisms of acute ischemic cerebrovascular syndrome (AICS) through gene expression profiling and pathway analysis.

METHODS

Peripheral whole blood samples were collected from 39 MRI-diagnosed patients with AICS and 25 nonstroke control subjects ≥ 18 years of age. Total RNA was extracted from whole blood stabilized in Paxgene RNA tubes, amplified, and hybridized to Illumina HumanRef-8v2 bead chips. Gene expression was compared in a univariate manner between stroke patients and control subjects using t test in GeneSpring. The significant genes were tested in a logistic regression model controlling for age, hypertension, and dyslipidemia. Inflation of type 1 error was corrected by Bonferroni and Ingenuity Systems Pathway analysis was performed. Validation was performed by QRT-PCR using Taqman gene expression assays.

RESULTS

A 9-gene profile was identified in the whole blood of ischemic stroke patients using gene expression profiling. Five of these 9 genes were identified in a previously published expression profiling study of stroke and are therefore likely biomarkers of stroke. Pathway analysis revealed toll-like receptor signaling as a highly significant canonical pathway present in the peripheral whole blood of patients with AICS.

CONCLUSIONS

Our study highlights the relevance of the innate immune system through toll-like receptor signaling as a mediator of response to ischemic stroke and supports the claim that gene expression profiling can be used to identify biomarkers of ischemic stroke. Further studies are needed to validate and refine these biomarkers for their diagnostic potential.

The genetics of ischaemic stroke

In this review, we discuss the genetic factors in both the aetiology and treatment of ischaemic stroke. We discuss candidate gene association studies, family linkage studies and the more recent whole genome association studies and whole genome expression studies. We also briefly discuss genetic testing for stroke risk and genetic analysis of treatment complications.

Hereditary spastic paraplegia and amyotrophy associated with a novel locus on chromosome 19

We identified a family in Mali with two sisters affected by spastic paraplegia. In addition to spasticity and weakness of the lower limbs, the patients had marked atrophy of the distal upper extremities. Homozygosity mapping using single nucleotide polymorphism arrays showed that the sisters shared a region of extended homozygosity at chromosome 19p13.11-q12 that was not shared by controls. These findings indicate a clinically and genetically distinct form of hereditary spastic paraplegia with amyotrophy, designated SPG43.

Multicenter analysis of glucocerebrosidase mutations in Parkinson's disease

BACKGROUND

Recent studies indicate an increased frequency of mutations in the gene encoding glucocerebrosidase (GBA), a deficiency of which causes Gaucher's disease, among patients with Parkinson's disease. We aimed to ascertain the frequency of GBA mutations in an ethnically diverse group of patients with Parkinson's disease.

METHODS

Sixteen centers participated in our international, collaborative study: five from the Americas, six from Europe, two from Israel, and three from Asia. Each center genotyped a standard DNA panel to permit comparison of the genotyping results across centers. Genotypes and phenotypic data from a total of 5691 patients with Parkinson's disease (780 Ashkenazi Jews) and 4898 controls (387 Ashkenazi Jews) were analyzed, with multivariate logistic-regression models and the Mantel-Haenszel procedure used to estimate odds ratios across centers.

RESULTS

All 16 centers could detect two GBA mutations, L444P and N370S. Among Ashkenazi Jewish subjects, either mutation was found in 15% of patients and 3% of controls, and among non-Ashkenazi Jewish subjects, either mutation was found in 3% of patients and less than 1% of controls. GBA was fully sequenced for 1883 non-Ashkenazi Jewish patients, and mutations were identified in 7%, showing that limited mutation screening can miss half the mutant alleles. The odds ratio for any GBA mutation in patients versus controls was 5.43 across centers. As compared with patients who did not carry a GBA mutation, those with a GBA mutation presented earlier with the disease, were more likely to have affected relatives, and were more likely to have atypical clinical manifestations.

CONCLUSIONS

Data collected from 16 centers demonstrate that there is a strong association between GBA mutations and Parkinson's disease.