Comparison of Different Osteobiologics in Terms of Imaging Modalities and Time Frames for Fusion Assessment in Anterior Cervical Discectomy and Fusion: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

The study's primary objective was to determine how osteobiologic choice affects fusion rates in patients undergoing anterior cervical discectomy and fusion (ACDF). The study's secondary objectives were to 1) determine the optimal timing of fusion assessment following ACDF and 2) determine if osteobiologic type affects the timing and optimal modality of fusion assessment.

METHODS

A systematic search of PubMed/MEDLINE was conducted for literature published from 2000 through October 2020 comparing anterior fusion in the cervical spine with various osteobiologics. Both comparative studies and case series of ≥10 patients were included.

RESULTS

A total of 74 studies met the inclusion criteria. Seventeen studies evaluated the efficacy of autograft on fusion outcomes, and 23 studies assessed the efficacy of allograft on fusion outcomes. 3 studies evaluated the efficacy of demineralized bone matrix, and seven assessed the efficacy of rhBMP-2 on fusion outcomes. Other limited studies evaluated the efficacy of ceramics and bioactive glasses on fusion outcomes, and 4 assessed the efficacy of stem cell products. Most studies utilized dynamic radiographs for the assessment of fusion. Overall, there was a general lack of supportive data to determine the optimal timing of fusion assessment meaningfully or if osteobiologic type influenced fusion timing.

CONCLUSIONS

Achieving fusion following ACDF appears to remain an intricate interplay between host biology and various surgical factors, including the selection of osteobiologics. While alternative osteobiologics to autograft exist and may produce acceptable fusion rates, limitations in study methodology prevent any definitive conclusions from existing literature.

Hospital outcomes in pediatric patients with Prader-Willi syndrome (PWS) undergoing orthopedic surgery: A 12-year analysis of national trends in surgical management and inpatient hospital outcomes

BACKGROUND

The incidence of orthopedic disorders amongst patients with Prader-Willi Syndrome (PWS) is high when compared to the general pediatric population. The purpose of this retrospective study was to define the most commonly performed orthopedic procedures in pediatric patients with PWS and to characterize the peri-operative outcomes of these patients.

METHODS

The Kids Inpatient Database (KID) was queried to collect data and identify all pediatric patients with PWS who underwent orthopedic procedures from 2001 to 2012. A total of 3684 patients with PWS were identified, 334 of who underwent an orthopedic procedure. Population demographics, comorbidities, and specific procedures undergone were defined. The incidences of postoperative complications and length of associated hospital stay were additionally evaluated.

RESULTS

Mean age of patients in this sample was 10.33 years (SD 4.5). The most common comorbidities included obesity (18.1%), chronic pulmonary disease (14.1%), hypothyroidism (5.1%), hypertension (5.1%), and uncomplicated diabetes (4%). Common procedures were spinal fusion (165/334, 49%) and lower extremity procedures (50/334, 15%). Complications included acute blood loss anemia, device related complications, pneumonia, sepsis, and urinary tract infections. The overall complication rate was 35.6%. Average hospital lengths of stay for patients undergoing spinal fusion was 6.68 days (SD 4.13), lower extremity orthopedic procedure was 5.65 days (SD 7.4), and all other orthopedic procedures was 7.74 days (SD 16.3).

CONCLUSIONS

Orthopedic disorders are common in patients with PWS. Consequently, spinal fusions and lower extremity procedures are commonly performed in this patient population. Associated comorbid conditions may negatively impact surgical outcomes in these patients. This information should prove useful in the peri-operative management of patients with PWS undergoing orthopedic surgery and for shared decision making with families.

Does Local Administration of Liposomal Bupivacaine Reduce Pain and Narcotic Consumption in Adult Spinal Deformity Surgery?

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine if local administration of liposomal bupivacaine (LB) reduces postoperative pain scores and narcotic use in spinal deformity patients.

METHODS

Adult patients undergoing elective spinal fusion (7 or more levels) for scoliosis or kyphosis were selected for inclusion. Patients received either periincisional injections of combined liposomal and standard bupivacaine (n = 90, group L) or standard bupivacaine only (n = 69, group C). Perioperative pain scores (VAS [visual analogue scale]), opioid use, length of stay, functional outcome (ODI [Oswestry Disability Index]), and perioperative complications were recorded. No external funding was received for this study.

RESULTS

A total of 159 patients met inclusion criteria (mean age was 54.2 years of age). No significant baseline demographic differences were noted between the 2 groups. Group L experienced slight improvements in pain control on postoperative day (POD) 1 (P = .02). No difference in pain scores were otherwise noted. Group L transitioned off of intravenous (IV) narcotics faster with 52.6% less IV use by POD3 (P = .03). No differences in total narcotic consumption, perioperative complications, lengths of stay, and functional outcome scores were otherwise noted between the 2 cohorts.

CONCLUSIONS

The use of LB in adult spinal deformity surgery does not appear to provide clinically important improvements in postoperative pain at the manufacturer's recommended dosage. Furthermore, while patients receiving LB may transition more quickly off of IV narcotics, this does not appear to translate into an overall decrease in narcotic consumption, hasten return of bowel function, or decrease hospital lengths of stay. Future prospective randomized control trials are warranted. The use of varying dosages of LB may also help further clarify the true efficacy of LB in the setting of spinal deformity surgery.

Autologous Stem Cells in Cervical Spine Fusion

STUDY DESIGN

Systematic review.

OBJECTIVES

To systematically review, critically appraise and synthesize evidence on use of stem cells from autologous stem cells from bone marrow aspirate, adipose, or any other autologous sources for fusion in the cervical spine compared with other graft materials.

METHODS

A systematic search of PubMed/MEDLINE was conducted for literature published through October 31, 2018 and through February 20, 2020 for EMBASE and ClinicalTrials.gov comparing autologous cell sources for cervical spine fusion to other graft options.

RESULTS

From 36 potentially relevant citations identified, 10 studies on cervical fusion met the inclusion criteria set a priori. Two retrospective cohort studies, one comparing cancellous bone marrow (CBM) versus hydroxyapatite (HA) and the other bone marrow aspirate (BMA) combined with autograft and HA versus autograft and HA alone, were identified. No statistical differences were seen between groups in either study for improvement in function, symptoms, or fusion; however, in the study evaluating BMA, the authors reported a statistically greater fusion rate and probability of fusion over time in the BMA versus the non-BMA group. Across case series evaluating BMA, authors reported improved function and pain and fusion ranged from 84% to 100% across the studies. In general, complications were poorly reported.

CONCLUSIONS

The overall quality (strength) of evidence of effectiveness and safety of autologous BMA for cervical arthrodesis in the current available literature was very low. Based on currently available data, firm conclusions regarding the effectiveness or safety of BMA in cervical fusions cannot be made.

Is Less Really More? Economic Evaluation of Minimally Invasive Surgery

STUDY DESIGN

Review.

OBJECTIVE

A comparative overview of cost-effectiveness between minimally invasive versus and equivalent open spinal surgeries.

METHODS

A literature search using PubMed was performed to identify articles of interest. To maximize the capture of studies in our initial search, we combined variants of the terms "cost," "minimally invasive," "spine," "spinal fusion," "decompression" as either keywords or MeSH terms. PearlDiver database was queried for open and minimally invasive surgery (MIS; endoscopic or percutaneous) reimbursements between Q3 2015 and Q2 2018.

RESULTS

In general, MIS techniques appeared to decrease blood loss, shorten hospital lengths of stay, mitigate complications, decrease perioperative pain, and enable quicker return to daily activities when compared to equivalent open surgical techniques. With regard to cost, primarily as a result of these latter benefits, MIS was associated with lower costs of care when compared to equivalent open techniques. However, cost reporting was sparse, and relevant methodology was inconsistent throughout the spine literature. Within the PearlDiver data sets, MIS approaches had lower reimbursements than open approaches for both lumbar posterior fusion and discectomy.

CONCLUSIONS

Current data suggests that overall cost-savings may be incurred with use of MIS techniques. However, data reporting on costs lacks in uniformity, making it difficult to formulate any firm conclusions regarding any incremental improvements in cost-effectiveness that may be incurred when utilizing MIS techniques when compared to equivalent open techniques.

Liposomal bupivacaine interscalene nerve block in shoulder arthroplasty is not superior to plain bupivacaine: a double-blinded prospective randomized control trial

BACKGROUND

Interscalene brachial plexus blocks are a common modality used to provide adjunctive pain relief with shoulder replacement surgery. In 2018, the Federal Drug Administration approved the use of liposomal bupivacaine (LB) for such nerve blocks. We sought to evaluate whether this formulation of bupivacaine would provide superior pain relief for shoulder replacement patients over standard bupivacaine alone. Our hypotheses were that in the LB cohort the average postoperative pain score over the first 72 hours would be significantly lower, time to block cessation would be longer, total opioid consumption would be lower, and the average patient satisfaction score regarding their pain management would be higher.

MATERIALS AND METHODS

A randomized, double-blinded study was designed comparing primary shoulder replacement surgery after an interscalene block with 25 mL of 0.5% plain bupivacaine vs. 133 mg of LB with 7.5 mL of 0.5% and 7.5 mL of 0.25% plain bupivacaine. A total of 104 patients were included in the study, with an equal number in each study arm. Patients' visual analog pain scores (VAPS) were followed for their inpatient stay, first 3 full outpatient days, and at a 3-week follow-up. Use of opioid medication was recorded for the same intervals and converted to morphine milligram equivalents. The time to first opioid rescue was documented, as well as the patients' satisfaction with their pain management at both the 3-day and 3-week intervals.

RESULTS

No clinically relevant advantage to the use of LB over plain bupivacaine was found. During the second postoperative day, the mean VAPS was 2.4 with LB vs. 3.3 in the standard cohort (P = .0409). The only other statistically significant finding was a higher VAPS with LB during the third full day home compared with standard bupivacaine (4.0 vs. 2.8, respectively, P = .0197). Both of these differences were less than the minimal clinically important difference of 2 for the VAPS. Analysis of the VAPS for the first and third postoperative days, the first and second full days home, and at 3 weeks revealed no significant difference. Similarly, there was no significant difference in time to first opioid rescue, total morphine milligram equivalent use, and patient satisfaction with pain management.

CONCLUSION

When used for an interscalene block to provide adjunctive pain relief in shoulder replacement surgery, the addition of LB to plain bupivacaine provides no additional clinically important benefit to the patient's pain experience over standard bupivacaine.

Adult spine deformity surgery in elderly patients: are outcomes worse in patients 75 years and older?

STUDY DESIGN

Retrospective study of a prospectively collected database at one center.

OBJECTIVES

Assess the outcomes and complications of adult spinal deformity (ASD) surgery in patients that are 75 years and older compared with patients of 65-75 years of age. With increasing amounts of ASD surgery being performed on elderly patients, it is important to assess how age plays a factor in corrective reconstruction surgery.

METHODS

Inclusion criteria for the study were all patients ≥ 65 years of age that underwent thoracolumbar deformity correction involving ≥ four levels at a single institution by two surgeons. Patients were divided based on age into 65-74.9 or ≥ 75 groups. Radiographic parameters were measured preoperatively, postoperatively, and at 2 years. The Numeric Rating Scale (NRS) and Oswestry Disability Index (ODI) were collected preoperatively, at 1 year, and 2 years. Comorbidities included were based around the Charlson Comorbidity Index (CCI) and compared to the incidence of complications and need for further surgery.

RESULTS

Both age groups had improvements in their radiographic parameters postoperatively which was maintained at 2 years. Comparing the different age groups with similar comorbidity burden in regard to complications and need for additional surgery yielded no statistically significant difference between groups. Both groups had comparable decreases in NRS and increases in ODI at 2 years.

CONCLUSIONS

Analysis of our study population indicates that there is no difference between the outcomes and complications of deformity surgery in patients 75 years and older when compared to a younger elderly population. It also does not appear that a ≥ 3 comorbidity burden has a significant impact on the complications or need for additional surgery in our elderly spinal deformity surgery population.

LEVEL OF EVIDENCE

Level IV.

Minimally Invasive Intradural Tumor Resection

In conjunction with neurofibromas, schwannomas are the second most commonly occurring intradural extramedullary tumor. They are a benign encapsulated nerve sheath tumor that are typically slow growing. They occur equally as frequently in the cervical and lumbar spine. If symptomatic, surgical resection may be warranted. In this surgical technique video, we present a case of a 70-year-old woman who presented with worsening symptoms consistent with cauda equina syndrome secondary to intradural masses at the L1-2 level. A minimally invasive resection of the intradural lesions was performed without any complication. Final pathology of the resected masses revealed schwannoma.

Immune Checkpoint Inhibition is Safe and Effective for Liver Cancer Prevention in a Mouse Model of Hepatocellular Carcinoma

Cirrhosis is a high-risk state for hepatocellular carcinoma (HCC) development and represents an opportunity to prevent cancer. In the precancerous state of cirrhosis, there is an accumulation of neoantigens that may be specifically targetable through immunotherapy. We asked whether immune checkpoint inhibition could prevent tumorigenesis in a mouse model of diethylnitrosamine and carbon tetrachloride-induced HCC. We found that initiation of anti-PD-1 therapy prior to tumorigenesis could prevent up to 46% of liver tumors. This significant reduction in tumor burden was accompanied by infiltration of CD4⁺ Th cells and CD8⁺ cytotoxic T cells into the liver parenchyma. Importantly, anti-PD-1 therapy did not exacerbate liver dysfunction or worsen overall health in this liver disease model. Given the safety and preservation of quality of life observed with long-term immunotherapy use, an immunotherapy chemoprevention strategy is likely associated with a low risk-to-benefit ratio and high value care in select patients. These results encourage a prevention trial in cirrhotic patients with the highest risk of developing HCC.See related Spotlight by Mohammed et al., p. 897.

Superior capsule reconstruction for irreparable rotator cuff tears: a systematic review of biomechanical and clinical outcomes by graft type

BACKGROUND

Superior capsular reconstruction (SCR) has recently been proposed as a surgical solution to the irreparable rotator cuff tear and has gained popularity because of promising early results. Therefore, the purpose of this study is to review the biomechanical and clinical outcomes in shoulders with this condition treated with SCR.

METHODS

A systematic review was conducted following PRISMA guidelines using PubMed, EMBASE, and Cochrane databases. Studies were included if they reported biomechanical, radiographic, or clinical outcomes data after undergoing SCR in shoulders with irreparable rotator cuff tears. Studies were broken down into 3 categories: cadaveric biomechanical studies, autograft clinical outcome studies, and allograft clinical outcome studies. Biomechanical, radiographic, patient-reported, and functional outcomes data were recorded for each study.

RESULTS

Eight cadaveric biomechanical studies, 5 autograft clinical studies, and 4 allograft clinical studies met inclusion criteria. In biomechanical studies, subacromial contact pressure and superior humeral translation were decreased in most tested scenarios. An increase in American Shoulder and Elbow Surgeons (ASES) scores, forward elevation and external rotation values, and acromiohumeral distance (AHD) were found in all autograft clinical studies reporting. Allograft clinical studies reported increases in ASES scores, forward elevation values, and AHD but decreases in visual analog scale scores in all studies reporting.

CONCLUSIONS

SCR is emerging as a viable surgical option to address the irreparable rotator cuff tear. Biomechanical studies suggest that the humeral head-stabilizing effect of SCR appears to translate into improved clinical outcomes. Future research should focus on further defining the indications, limitations, and optimal technique.

Risk factors for delay in surgery for patients undergoing elective anterior cervical discectomy and fusion

BACKGROUND

Anterior cervical discectomy and fusion (ACDF) is well-tolerated by most patients and commonly necessitates only a short hospital admission. Surgical delay after hospital admission, however, may result in longer hospital stays, consequently increasing hospital resource utilization. The current study evaluates risk factors for surgical delay in patients undergoing elective ACDF.

METHODS

A retrospective analysis of ACS-NSQIP data from 2006-2015 was performed. Patients undergoing elective ACDF were selected using current procedural terminology (CPT) codes (22251, 22252, 22554). A surgical delay was defined as surgery that occurred one day or later after initial hospital admission. Differences in outcomes between the non-delayed and delayed cohorts were evaluated with univariate analysis. Multivariate logistic regression was performed to identify risk factors for surgical delay.

RESULTS

There were a total of 771 (2.0%) surgical delays out of 39,371 patients undergoing elective ACDF from 2006-2015. Multivariate analysis found partially dependent functional status (OR 5.88; 95% CI: 4.48-7.71; P<0.001), totally dependent functional status (OR 18.22; 95% CI: 9.60-34.59; P<0.001), ASA class 4 (OR 2.73; 95% CI: 1.70-4.38; P<0.001), bleeding disorders (OR 1.75; 95% CI: 1.08-2.85; P=0.024), male sex (OR 1.19; 95% CI: 1.03-1.38; P=0.019), and chronic steroid use (OR 1.76; 95% CI: 1.30-2.37; P<0.001) as independent predictors of delay. Univariate analysis found surgical delay was associated with a higher rate of post-operative major adverse events (4.8% vs. 1.1%; P<0.001), mortality (1.0% vs. 0.2%; P<0.001) and greater than five-fold increase in total length of stay (9.52 vs. 1.65 days; P<0.001).

CONCLUSIONS

Impaired pre-operative functional status, a higher comorbidity burden, and chronic steroid use are risk factors for surgical delay, increased complications, and length of stay in patients undergoing elective ACDF. This is helpful information to consider given a rising incidence of cervical fusions in the Medicare population, a wide variation in costs, and increasing popularity of bundled-payment models.

LEVEL OF EVIDENCE

3.

Implementing the Lever Sign in the Emergency Department: Does it Assist in Acute Anterior Cruciate Ligament Rupture Diagnosis? A Pilot Study

BACKGROUND

Within the emergency department (ED) setting, anterior cruciate ligament (ACL) rupture is commonly misdiagnosed, leading to improper treatment and potential meniscal injury and total joint replacement. Utilizing traditional clinical tests to diagnosis ACL rupture leads to the correct diagnosis in about 30% of cases. The lever sign is a new and effective clinical test used to diagnose ACL rupture with 100% sensitivity.

OBJECTIVE

We aim to study if the lever sign used in the ED setting is more sensitive to diagnose ACL rupture than traditional tests.

METHODS

Patients between 12 and 55 years of age were examined utilizing either traditional methods or the lever sign. Diagnostic findings in the ED were compared with those of a sports medicine specialist using magnetic resonance imaging as the diagnostic standard. A survey was given to ED providers to collect data on diagnosis and physician confidence in diagnosis.

RESULTS

The sensitivity of the lever sign was 100% (94.7% accuracy, 93.75% specificity), whereas the sensitivity of the anterior drawer/Lachman test was 40% (87.5% accuracy, 100% specificity). Physician confidence in diagnosis was higher utilizing the lever sign vs. the anterior drawer/Lachman test at 8.45 (±1.82) compared with 7.72 (±1.82) out of 10, respectively. There was no statistically significant association between diagnostic accuracy with either test and level of training of the ED provider.

CONCLUSION

Implementation of the lever sign in the ED setting resulted in a higher sensitivity, higher physician confidence in screening test diagnosis, and a decrease in the number of undiagnosed ACL ruptures.

Minimum Clinically Important Difference: Current Trends in the Orthopaedic Literature, Part I: Upper Extremity: A Systematic Review

BACKGROUND

The minimum clinically important difference (MCID) attempts to define the patient's experience of treatment outcomes. Efforts at calculating the MCID have yielded multiple and inconsistent MCID values. The purposes of this review were to describe the usage of the MCID in the most recent orthopaedic literature, to explain the limitations of its current uses, and to clarify the underpinnings of MCID calculation. Subsequently, we hope that the information presented here will help practitioners to better understand the MCID and to serve as a guide for future efforts to calculate the MCID. The first part of this review focuses on the upper-extremity orthopaedic literature. Part II will focus on the lower-extremity orthopaedic literature.

METHODS

A review was conducted of the 2014 to 2016 publications in The Journal of Arthroplasty, The Journal of Bone & Joint Surgery, The American Journal of Sports Medicine, Foot & Ankle International, Journal of Orthopaedic Trauma, Journal of Pediatric Orthopaedics, and Journal of Shoulder and Elbow Surgery. Only clinical science articles utilizing patient-reported outcome measure (PROM) scores were included in the analysis. A keyword search was then performed to identify articles that calculated or referenced the MCID. Articles were then further categorized into upper-extremity and lower-extremity publications. MCID utilization in the selected articles was subsequently characterized and recorded.

RESULTS

The MCID was referenced in 129 (7.5%) of 1,709 clinical science articles that utilized PROMs: 52 (40.3%) of 129 were related to the upper extremity, 5 (9.6%) of 52 independently calculated MCID values, and 47 (90.4%) of 52 used previously published MCID values as a gauge of their own results. MCID values were considered or calculated for 16 PROMs; 12 of these were specific to the upper extremity. Six different methods were used to calculate the MCID. Calculated MCIDs had a wide range of values for the same PROM (e.g., 8 to 36 points for Constant-Murley scores and 6.4 to 17 points for American Shoulder and Elbow Surgeons [ASES] scores).

CONCLUSIONS

Determining useful MCID values remains elusive and is compounded by the proliferation of PROMs in the field of orthopaedics. The fundamentals of MCID calculation methods should be critically evaluated. If necessary, these methods should be corrected or abandoned. Furthermore, the type of change intended to be measured should be clarified: beneficial, detrimental, or small or large changes. There should also be assurance that the calculation method actually measures the intended change. Finally, the measurement error should consistently be reported.

CLINICAL RELEVANCE

The MCID is increasingly used as a measure of patients' improvement. However, the MCID does not yet adequately capture the clinical importance of patients' improvement.

Epidemiology of Lumbar Spine Injuries in Men's and Women's National Collegiate Athletic Association Basketball Athletes

Background:

Lumbar spine injuries (LSIs) are common in both men’s and women’s National Collegiate Athletic Association (NCAA) basketball players and can frequently lead to reinjuries and persistent pain.

Purpose:

To describe the epidemiology of an LSI in collegiate men’s and women’s basketball during the 2009-2010 through 2013-2014 academic years.

Study Design:

Descriptive epidemiology study.

Methods:

The incidence and characteristics of LSIs were identified utilizing the NCAA Injury Surveillance Program (ISP). Rates of injury were calculated as the number of injuries divided by the total number of athlete-exposures (AEs). AEs were defined as any student participation in 1 NCAA-sanctioned practice or competition. Incidence rate ratios (IRRs) were then calculated to compare the rates of injury between season, event type, mechanism, injury recurrence, and time lost from sport.

Results:

The NCAA ISP reported 124 LSIs from an average of 28 and 29 men’s and women’s teams, respectively. These were used via validated weighting methodology to estimate a total of 5197 LSIs nationally. The rate of LSIs in women was 2.16 per 10,000 AEs, while men suffered LSIs at a rate of 3.47 per 10,000 AEs. Men were 1.61 times more likely to suffer an LSI compared with women. In men, an LSI was 3.48 times more likely to occur in competition when compared with practice, while in women, an LSI was 1.36 times more likely to occur in competition than in practice. Women suffered the highest LSI rate during the postseason, while the highest rate in men was during the regular season. The majority of both female (58.9%; n = 1004) and male (73.1%; n = 2353) athletes returned to play within 24 hours of injury.

Conclusion:

To date, this is the largest study to characterize LSIs in NCAA basketball and provides needed information on the prevalence and timing of these injuries. The majority of injuries in both sexes were new, and most athletes returned to play in less than 24 hours. Injury rates were highest during competition in both sexes.

Patellar osteolysis after total knee arthroplasty with patellar resurfacing: a potentially underappreciated problem

Osteolysis of the patella following total knee arthroplasty is both uncommon and poorly described in the literature. We describe 3 cases of total knee arthroplasty with patella resurfacing that later presented with anterior knee pain with patellar osteolysis without evidence of patellar implant failure: 2 males and 1 female patient, all with bilateral knee osteoarthritis. Osteolysis of the patella was identified radiographically between 2 and 16 years from the index procedure. We theorize that high pressures across the patella-femoral joint, in obese or muscular patients, may play a role in the formation of these patellar osteolytic lesions. We suspect that the prevalence of this phenomenon is under-recognized in the literature and may increase with longer term follow-up and awareness.

Analysis of 90-Day Readmissions After Total Shoulder Arthroplasty

Background

The number of total shoulder arthroplasty (TSA) procedures performed annually is increasing as a result of an aging population and an increased access to subspecialty-trained upper extremity arthroplasty surgeons. An up-to-date analysis of the incidence of, risk factors for, and reasons for 90-day readmissions in primary anatomic TSA has yet to be performed.

Purpose

To characterize 90-day readmissions on a national level. An understanding of these data will help to predict resource utilization and expenses in shoulder arthroplasty.

Study Design

Case-control study; Level of evidence, 3.

Methods

All adult patients undergoing elective primary TSA in 2014 who were included in the National Readmission Database were included in the analysis. Two cohorts were created according to 90-day readmission status. Multivariable analysis was then performed to determine predictors of 90-day readmissions. Reasons for 30-, 60-, and 90-day readmissions were identified, and total hospital resource utilization was calculated.

Results

An estimated 26,023 patients were identified. The 30-, 60-, and 90-day rates of readmissions were 0.6%, 1.2%, and 1.7%, respectively. There was no difference in comorbidity burden between the cohorts. Medicare payer status (odds ratio [OR], 1.63; 95% CI, 1.00-2.65; P = .05), transfer to a skilled nurse facility (OR, 1.50; 95% CI, 1.05-2.14; P = .02), and chronic obstructive pulmonary disease (OR, 1.32; 95% CI, 1.04-1.66; P = .02) were identified as predictors of 90-day readmission. Female sex decreased odds of 90-day readmission (OR, 0.72; 95% CI, 0.59-0.87; P = .001). Ninety-day readmissions were associated with significant cost increases (P < .001). The most common identifiable reason for related readmissions was a hardware-related complication at all time points.

Conclusion

While uncommon, 90-day readmissions after primary TSA are associated with significant patient morbidity and ultimately substantial hospital costs. Truncating readmission analysis at a 30-day period will miss most arthroplasty-related hospital readmissions.

Elbow Injuries in National Collegiate Athletic Association Football Players: An Epidemiological Study Spanning 5 Academic Years

Background

National Collegiate Athletic Association (NCAA) football players are at a high risk of injuries. Elbow injuries are uncommon, but there are insufficient data specifically on elbow injuries sustained in NCAA football players.

Purpose

To define the epidemiology of elbow injuries in NCAA football players during the 2009-2010 to 2013-2014 seasons using data from the NCAA Injury Surveillance Program (NCAA-ISP).

Study Design

Descriptive epidemiology study.

Methods

Using the NCAA-ISP database, a convenience sample of NCAA football athletes was reviewed to determine the types, rates, and trends in elbow injuries. Several factors were examined, including the diagnosis, injury setting, time lost from sport, surgical necessity, and injury recurrence. Raw injury data were obtained as well as weighted totals from the NCAA-ISP to generate national estimates and adjust for underreporting. Injury rates were calculated by dividing the number of injuries by the total number of athlete-exposures (AEs). The rate ratios of injuries during competition versus practice were compared, as were the rate ratios of preseason, regular-season, and postseason injuries by type.

Results

We identified 4874 total elbow injuries from the 2009-2010 to 2013-2014 seasons. The rate of injuries overall was 1.892 per 10,000 AEs. The rate for competition was 9.053 per 10,000 AEs and 1.121 per 10,000 AEs for practice. The rate ratio between competition and practice was 8.08 (95% CI, 6.04-10.80). Injury rates for the preseason, regular season, and postseason were 1.851, 1.936, and 1.406 per 10,000 AEs, respectively. Acute elbow instability was the most common injury type (65.43%). The most common mechanism was a contact injury (86.77%); 96.82% of injuries did not require surgery, and most elbow injuries required less than 24 hours of participation restriction (67.33%).

Conclusion

Although elbow injuries in NCAA football players are uncommon, it is important to recognize and treat these injuries appropriately. Dislocations and ulnar collateral ligament injuries caused athletes to miss extended periods of play. Fortunately, a majority of injuries resulted in less than 24 hours of participation restriction. Particular attention should be given to preventing elbow injuries, especially ulnar collateral ligament strains, hyperextension injuries, and acute instability.

Elbow Injuries in National Collegiate Athletic Association Athletes: A 5-Season Epidemiological Study

Background:

Little research has focused on the rates and patterns of elbow injuries in National Collegiate Athletic Association (NCAA) student-athletes.

Purpose:

To describe the epidemiological patterns of elbow injuries in NCAA athletes during 5 seasons over the academic years 2009 through 2014 using the NCAA Injury Surveillance Program (NCAA-ISP) database.

Study Design:

Descriptive epidemiology study.

Methods:

A voluntary convenience sample of NCAA varsity teams from 11 sports was examined to determine the rates and patterns of elbow injuries. Rates and distributions of elbow injuries were identified within the context of sport, event type, time in season, mechanism, time lost from sport, surgical treatment, and injury type. Rates of injury were calculated as the number of injuries divided by the total number of athlete-exposures (AEs). An AE was defined as any student participation in 1 NCAA-sanctioned practice or competition with an inherent risk of exposure to potential injury. Injury rate ratios (IRRs) and injury proportion ratios (IPRs) were then calculated to compare the rates within and between sports by event type, season, sex, mechanism, surgical treatment, and time lost from sport. Comparisons between sexes were made using only sports data that had both male and female samples.

Results:

Overall, 373 elbow injuries were reported in the NCAA-ISP data set during the 2009-2010 through 2013-2014 academic years among 11 varsity sports. The overall rate of injury was 1.76 per 10,000 AEs. The rate of elbow injuries in men was 0.74 per 10,000 AEs, while women experienced injuries at a rate of 0.63 per 10,000 AEs. In sex-comparable sports, men were 1.17 times more likely to experience an elbow injury compared with women. Men’s wrestling (6.00/10,000 AEs) and women’s tennis (1.86/10,000 AEs) were the sports with the highest rates of elbow injuries by sex, respectively. The top 3 highest injury rates overall occurred in men’s wrestling, baseball, and tennis. Elbow injuries were 3.5 times more likely to occur during competition compared with practice. Athletes were 0.76 times less likely to sustain an elbow injury during the preseason compared with in-season. Contact events were the most common mechanism of injury (67%). For sex-comparable sports, men were 2.41 times more likely than women to have contact as their injury mechanism (95% CI, 0.78-7.38). The majority of athletes missed less than 24 hours of participation time (67%), and only a minority (3%) of patients with elbow injuries went on to have surgical intervention. Elbow ulnar collateral ligament injuries were most common (26% of total injuries).

Conclusion:

Analysis of the study data demonstrated a significant rate of elbow injuries, 1.76 injuries per 10,000 AEs in NCAA collegiate athletes. Higher injury rates can be expected in males within sex-comparable sports. Elbow injuries are most common in the setting of competitions and most commonly occur secondary to contact-type mechanisms. Injuries were more likely to occur during in-season play. The majority of injuries required less than 24 hours of time away from sport and did not require surgical intervention.

Lower Back Injuries in National Collegiate Athletic Association Football Players: A 5-Season Epidemiological Study

Background:

Low back injuries are common in collegiate football players and can frequently lead to persistent pain, reinjuries, and time lost from participation.

Purpose:

To describe the epidemiology of back injuries in National Collegiate Athletic Association (NCAA) football players during the 2009/2010 through 2013/2014 academic years utilizing the NCAA Injury Surveillance Program (ISP) database.

Study Design:

Descriptive epidemiology study.

Methods:

A convenience sample of NCAA varsity football teams was utilized to determine the rates and patterns of back injuries as well as to generate national injury estimates. The rates and distribution of back injuries were identified within the context of mechanism of injury, injury chronicity, and time lost from sport. Injury rates were calculated as the number of injuries divided by the total number of athlete-exposures (AEs). Incidence rate ratios were calculated to compare the rates of injury between season, event type, mechanism of injury, injury chronicity, and time lost from sport.

Results:

Nationally, there were 267 low back injuries reported in the database. These were used to estimate 7076 back injuries over the 5-year period, approximately 82% of which were new injuries. The injuries occurred at a rate of 2.70 per 10,000 AEs. Overall, injuries were 3.12 times more likely to occur in competitions than in practices. Athletes were 4.67 times more likely to sustain a back injury during the preseason compared with the postseason but were 1.41 times more likely to sustain a low back injury during the preseason compared with the regular season. Both contact and noncontact were reported equally as the mechanism of injury (37.8% and 38.3%, respectively), and unspecified low back pain was the most common injury (64.2%). Only 1.6% of patients required surgery for their injury, and the majority of athletes (59.6%) returned to play within 24 hours.

Conclusion:

There was a relatively high rate of lumbar back injuries at the collegiate level (2.70/10,000 AEs), the majority of which were new injuries. About 18% of reported injuries were reinjuries. Although very few required surgery, a careful examination and work-up should be conducted to evaluate each injury. Regimented physical therapy and reconditioning programs are recommended to avert reinjuries.

Two-Stage Debridement With Prosthesis Retention for Acute Periprosthetic Joint Infections

BACKGROUND

Historically, infection control rates with debridement and component retention have been poor in the management of acute prosthetic joint infections. We previously described a 2-stage debridement with prosthesis retention protocol for acute periprosthetic joint infection and reported a 90% success rate in a sample of 20 patients.

METHODS

A retrospective review of 83 patients who underwent a 2-stage debridement with implant retention with a minimum 1-year follow-up was performed. Patient data were primarily analyzed to determine infection control rates. Infections were considered controlled when patients had not undergone a reoperation for infection, and demonstrated lack of any clinical signs or symptoms of infection (a well healed wound, diminishing swelling and warmth, absence of erythema, improvement in baseline pain symptoms) A secondary goal of this study was to examine the effects of symptom duration on infection control rate.

RESULTS

Average patient follow-up was 41.8 months (range 12-171) for all patients. The overall protocol success rate was 86.7% (72/83): 82.9% in hips and 89.6% in knees. Additionally, protocol success was observed in 45 of 48 primary joints (93.8%) and 27 of 35 (77.1%) revision joints (P = .046). Average time from onset of symptoms to surgery was 6.2 days for successfully treated patients (range 0-27 days) compared to 10.7 days for those who failed treatment (range 1-28 days, P = .070).

CONCLUSION

This 2-stage retention protocol resulted in a higher likelihood of infection control compared to prior reports of single stage debridement and modular part exchange.

Ninety-day readmissions following reverse total shoulder arthroplasty

Background

An adequate characterization of 90-day readmissions after primary reverse total shoulder arthroplasty (RTSA) on a national level remains to be undertaken. As bundled payment models become more prevalent, an improved understanding of readmission data will help to predict resource utilization and expenses.

Methods

All adult patients who underwent elective primary RTSA in 2014 in the National Readmission Database were included in the analysis. Two cohorts were created based on 90-day readmission status. Multivariate analysis was then performed to determine predictors of 90-day readmissions. Reasons for 30-, 60-, and 90-day readmissions were identified. Total hospital resource utilization was calculated.

Results

An estimated 25,196 patients were identified. The 30-, 60-, and 90-day rates of readmissions were 0.6%, 1.2%, and 1.7%, respectively. Diabetes (odds ratio [OR], 1.42; 95% confidence interval [CI], 1.14-1.78), hypertension (OR, 1.63; 95% CI, 1.28-2.08), paralysis (OR, 3.61; 95% CI, 1.63-7.97), and solid tumor without metastasis (OR, 2.72; 95% CI, 1.21-6.12) were identified as independent predictors of 90-day readmission. Ninety-day readmissions were associated with a significant increase in cost (P = .02). The most common related reason for 90-day readmission was hardware-related complications at all time points.

Conclusion

Although uncommon, 90-day readmissions after primary RTSA are associated with significant patient morbidity and consequently substantial hospital costs.

Lumbar Spine Injuries in National Collegiate Athletic Association Athletes: A 6-Season Epidemiological Study

Background:

Lumbar spine injuries in National Collegiate Athletic Association (NCAA) athletes have not been well studied.

Purpose:

To describe the epidemiology of lumbar spine injuries in NCAA athletes during the 2009/2010 through 2014/2015 academic years utilizing the NCAA Injury Surveillance Program (ISP).

Study Design:

Descriptive epidemiology study.

Methods:

A voluntary convenience sample of NCAA varsity teams from 25 sports was examined. Mechanism of injury, injury recurrence, and time lost from sport were recorded. Injury rates were calculated as the number of injuries divided by the total number of athlete-exposures (AEs). AEs were defined as any student participation in 1 NCAA-sanctioned practice or competition. Injury rate ratios and injury proportion ratios were calculated to compare the rates within and between sports by event type, season, patient sex, mechanism, injury recurrence, and time lost from sport. Comparisons between sexes were made utilizing data that had both male and female samples.

Results:

An estimated 37,435 lumbar spine injuries were identified. The overall rate of injuries was 6.01 per 1000 AEs. The rate of injuries was 4.94 per 1000 AEs in men compared with 3.94 per 1000 AEs in women for sex-comparable sports. Men were 1.25 times more likely than women to suffer a lumbar spine injury. Men’s football (24.62 injuries/1000 AEs) and women’s gymnastics (11.46 injuries/1000 AEs) had the highest rates of lumbar spine injuries. Athletes were 1.83 and 3.71 times more likely to sustain a lumbar spine injury during the preseason than the regular season or postseason, respectively. Noncontact was the most common mechanism of injury (38%). Injury recurrence was most common in men’s outdoor track (58%). Most injuries resulted in less than 24 hours of time loss from event participation (61%).

Conclusion:

The rate of lumbar spine injuries was high in NCAA athletes, and injuries commonly recurred (20%). In general, men were more likely to sustain a lumbar spine injury compared with women. Higher injury rates occurred during competition and via a noncontact mechanism of injury. In addition to prevention programs, reconditioning programs should be considered to prevent these injuries.

The future of disc surgery and regeneration

Low back and neck pain are among the top contributors for years lived with disability, causing patients to seek substantial non-operative and operative care. Intervertebral disc herniation is one of the most common spinal pathologies leading to low back pain. Patient comorbidities and other risk factors contribute to the onset and magnitude of disc herniation. Spine fusions have been the treatment of choice for disc herniation, due to the conflicting evidence on conservative treatments. However, re-operation and costs have been among the main challenges. Novel technologies including cage surface modifications, biologics, and 3D printing hold a great promise. Artificial disc replacement has demonstrated reduced rates of adjacent segment degeneration, need for additional surgery, and better outcomes. Non-invasive biological approaches are focused on cell-based therapies, with data primarily from preclinical settings. High-quality comparative studies are needed to evaluate the efficacy and safety of novel technologies and biological therapies.

Peripheral Nerve Blocks vs Periarticular Injections in Total Knee Arthroplasty

In patients undergoing surgery, optimal pain management is associated with improved perioperative outcomes, patient satisfaction with surgery, and a more rapid functional recovery. In recent years, the employment of multimodal pain management strategies has become increasingly widespread. In particular, there has been an explosion in the use of peripheral nerve blockade and periarticular injections in total knee arthroplasty. However, there is significant variability in the administration of either modality of anesthesia. As such, a critical evaluation of the current literature is warranted to elucidate the advantages and disadvantages of each technique with the ultimate goal of further refining current pain control strategies. In this symposium, we review each of these modalities and their association with pain management, narcotic consumption, length of hospital stay, and adverse events.

Obstructive Sleep Apnea in Elective Spine Surgery: National Prevalence and Inpatient Outcomes

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Epidemiologic studies suggest that the prevalence of moderate to severe obstructive sleep apnea (OSA) is increasing. OSA has been linked to increased rates of postoperative complications following surgery. Large studies, however, regarding surgical outcomes in this patient population, particularly in the spine literature, are limited. Consequently, the purpose of this study was to assess the prevalence of and postoperative risks conferred by OSA in the elective spine population.

METHODS

Using data from the National Inpatient Sample from 2008 to 2012, an estimated 56 372 (5.1%) patients with OSA undergoing elective cervical and thoracolumbar spine surgery were selected and compared to 1 052 837 patients without OSA undergoing the same procedures. Our primary outcome measures included postoperative complication rates, inpatient mortality, length of stay, and total hospital charges.

RESULTS

Patients with OSA were, on average 2.6 years older than those without OSA (P < .001) and had a higher comorbidity burden. The prevalence of OSA increased between 2008 and 2012 from 3.5% to 6.8%; P < .001. OSA was associated with a 3-fold increase in major complications (P < .001) and was confirmed as an independent risk factor for major complications based on multivariate analysis (odds ratio [OR] = 2.82; 95% CI = 2.59-2.79; P < .001). Rates of deep venous thrombosis were doubled in patients with OSA. OSA was determined to be an independent predictor of pulmonary complications (OR = 2.69; 95% CI = 2.59-2.79; P < .001). OSA did not increase the risk of postoperative mortality.

CONCLUSIONS

Patients with OSA often have multiple concomitant comorbidities and consequently are at increased risk of experiencing a more difficult postoperative course following elective spine surgery. Specifically, increased risks of pulmonary complications and deep venous thrombosis should be anticipated.

Incorporation of Anterior Lumbosacral Spine Exposure into a General Surgical Practice

Many spine surgeons enlist the aid of an "access surgeon" to provide anterior exposure of the lumbosacral spine. We proposed that a single, community hospital general surgery practice can successfully develop an anterior spine exposure program with acceptable clinical outcomes. One hundred and forty-three consecutive anterior exposures were performed between 2008 and 2014. Morbidity and 30-day mortality were recorded. The effects of American Society of Anesthesiologists Physical Status classification (ASA class) and number of levels exposed on length of stay (LOS) and estimated blood loss (EBL) was reported. The growth of the program during this period was also evaluated. During the six-year period, there were nine (6.3%) major complications and 17 (11.9%) minor complications with no 30-day mortality. The mean LOS was similar for one-level and two-level exposures (3.8 days). Mean LOS was higher in ASA III patients (4.4 days) than ASA I (2.9 days) or ASA II (3.2 days). Mean EBL for one-level exposures (336.3 mL) was not significantly different than EBL for two-level exposures (425.9 mL). EBLs in ASA class III patients were greater than in class I and class II patients. The program began in July of 2008 with a single spine surgeon and one operation that year. A high of 54 procedures, with seven different spine surgeons, was recorded in 2013. A single, community hospital general surgery practice can successfully develop an anterior approach to spine exposure program with acceptable clinical outcomes and with sustained growth of the program.

Incorporation of Anterior Lumbosacral Spine Exposure into a General Surgical Practice

Many spine surgeons enlist the aid of an “access surgeon” to provide anterior exposure of the lumbosacral spine. We proposed that a single, community hospital general surgery practice can successfully develop an anterior spine exposure program with acceptable clinical outcomes. One hundred and forty-three consecutive anterior exposures were performed between 2008 and 2014. Morbidity and 30-day mortality were recorded. The effects of American Society of Anesthesiologists Physical Status classification (ASA class) and number of levels exposed on length of stay (LOS) and estimated blood loss (EBL) was reported. The growth of the program during this period was also evaluated. During the six-year period, there were nine (6.3%) major complications and 17 (11.9%) minor complications with no 30-day mortality. The mean LOS was similar for one-level and two-level exposures (3.8 days). Mean LOS was higher in ASA III patients (4.4 days) than ASA I (2.9 days) or ASA II (3.2 days). Mean EBL for one-level exposures (336.3 mL) was not significantly different than EBL for two-level exposures (425.9 mL). EBLs in ASA class III patients were greater than in class I and class II patients. The program began in July of 2008 with a single spine surgeon and one operation that year. A high of 54 procedures, with seven different spine surgeons, was recorded in 2013. A single, community hospital general surgery practice can successfully develop an anterior approach to spine exposure program with acceptable clinical outcomes and with sustained growth of the program.

Arid1b haploinsufficient mice reveal neuropsychiatric phenotypes and reversible causes of growth impairment

Sequencing studies have implicated haploinsufficiency of ARID1B, a SWI/SNF chromatin-remodeling subunit, in short stature (Yu et al., 2015), autism spectrum disorder (O'Roak et al., 2012), intellectual disability (Deciphering Developmental Disorders Study, 2015), and corpus callosum agenesis (Halgren et al., 2012). In addition, ARID1B is the most common cause of Coffin-Siris syndrome, a developmental delay syndrome characterized by some of the above abnormalities (Santen et al., 2012; Tsurusaki et al., 2012; Wieczorek et al., 2013). We generated Arid1b heterozygous mice, which showed social behavior impairment, altered vocalization, anxiety-like behavior, neuroanatomical abnormalities, and growth impairment. In the brain, Arid1b haploinsufficiency resulted in changes in the expression of SWI/SNF-regulated genes implicated in neuropsychiatric disorders. A focus on reversible mechanisms identified Insulin-like growth factor (IGF1) deficiency with inadequate compensation by Growth hormone-releasing hormone (GHRH) and Growth hormone (GH), underappreciated findings in ARID1B patients. Therapeutically, GH supplementation was able to correct growth retardation and muscle weakness. This model functionally validates the involvement of ARID1B in human disorders, and allows mechanistic dissection of neurodevelopmental diseases linked to chromatin-remodeling.

DOI:http://dx.doi.org/10.7554/eLife.25730.001

DNA does not just float freely inside our cells. Instead, it is wound around proteins called histones and packaged tidily into a form called chromatin. This packaging allows genes to be switched on or off by making it easier or harder to access different stretches of the genetic code.

A group of proteins called the SWI/SNF chromatin-remodeling complex are responsible for the packing and unpacking of DNA during development, dictating the fate of thousands of genes. Mutations that affect one component of this complex, a protein known ARID1B, are associated with a rare genetic condition called Coffin-Siris syndrome, and may also have a role to play in autism spectrum disorders and intellectual disability. However, there were previously no animal models that can be used to study this mutation in the laboratory.

Celen, Chuang et al. have now genetically modified mice to remove one of their two copies of the gene that encodes the mouse equivalent of ARID1B. This change replicates the mutation that is most commonly seen in people with Coffin-Siris syndrome. Celen, Chuang et al. report that the mutant mice with just one working copy of the gene showed many features also seen in Coffin-Siris syndrome, including a smaller size and weaker muscles. The mutant mice also repeated certain behaviors, like grooming themselves, and showed unusual interactions with other mice.

Further tests showed that the mutant mice had lower than expected levels of growth hormone in their blood. The mice were then treated with growth hormone supplements to find out if this could reverse any of their symptoms. Indeed, this treatment made the mice larger and stronger, but did not change their behavior.

Some doctors are already treating people with Coffin-Siris syndrome with growth hormone, and these new findings suggest that this treatment counteracts defects caused directly by the mutation affecting ARID1B. Moreover, this mouse model will allow the role of ARID1B to be investigated further in the laboratory, and could be used as a tool to discover, develop and test new treatments for Coffin-Siris syndrome.

DOI:http://dx.doi.org/10.7554/eLife.25730.002

Isolation of human adipose-derived stromal cells using laser-assisted liposuction and their therapeutic potential in regenerative medicine

Harvesting adipose-derived stromal cells (ASCs) for tissue engineering is frequently done through liposuction. However, several different techniques exist. Although third-generation ultrasound-assisted liposuction has been shown to not have a negative effect on ASCs, the impact of laser-assisted liposuction on the quality and differentiation potential of ASCs has not been studied. Therefore, ASCs were harvested from laser-assisted lipoaspirate and suction-assisted lipoaspirate. Next, in vitro parameters of cell yield, cell viability and proliferation, surface marker phenotype, osteogenic differentiation, and adipogenic differentiation were performed. Finally, in vivo bone formation was assessed using a critical-sized cranial defect in athymic nude mice. Although ASCs isolated from suction-assisted lipoaspirate and laser-assisted lipoaspirate both successfully underwent osteogenic and adipogenic differentiation, the cell yield, viability, proliferation, and frequency of ASCs (CD34(+)CD31(-)CD45(-)) in the stromal vascular fraction were all significantly less with laser-assisted liposuction in vitro (p < .05). In vivo, quantification of osseous healing by micro-computed tomography revealed significantly more healing with ASCs isolated from suction-assisted lipoaspirate relative to laser-assisted lipoaspirate at the 4-, 6-, and 8-week time points (p < .05). Therefore, as laser-assisted liposuction appears to negatively impact the biology of ASCs, cell harvest using suction-assisted liposuction is preferable for tissue-engineering purposes.

Akt/PKB promotes cancer cell invasion via increased motility and metalloproteinase production

The Akt/protein kinase B (PKB) serine/threonine kinase is well known as an important mediator of many cell survival signaling pathways. Here, we demonstrate for the first time a major role of Akt/PKB in the cell invasion properties of the highly metastatic cell line HT1080. Using confocal microscopic analyses of live samples, we found Akt/PKB to be localized in the leading edge membrane area of migrating HT1080 cells. This localization was dependent on phosphoinositide 3-kinase and required the lipid binding ability of the phosphoinositide binding pleckstrin homology domain of Akt/PKB. We examined the possible function of Akt/PKB in HT1080 invasion. Surprisingly, Akt/PKB potently promoted HT1080 invasion, by increasing cell motility and matrix metalloproteinase-9 (MMP-9) production, in a manner highly dependent on its kinase activity and membrane-translocating ability. The increase in MMP-9 production was mediated by activation of nuclear factor-kappaB transcriptional activity by Akt/PKB. However, Akt/PKB did not affect the cell-cell or cell-matrix adhesion properties of HT1080. Our findings thus establish Akt/PKB as a major factor in the invasive abilities of cancer cells.

Se-methylselenocysteine induces apoptosis mediated by reactive oxygen species in HL-60 cells

Recent studies have implicated apoptosis as one of the most plausible mechanisms of the chemopreventive effects of selenium compounds, and reactive oxygen species (ROS) as important mediators in apoptosis induced by various stimuli. In the present study, we demonstrate that Se-methylselenocysteine (MSC), one of the most effective selenium compounds at chemoprevention, induced apoptosis in HL-60 cells and that ROS plays a crucial role in MSC-induced apoptosis. The uptake of MSC by HL-60 cells occurred quite early, reaching the maximum within 1 h. The dose-dependent decrease in cell viability was observed by MSC treatment and was coincident with increased DNA fragmentation and sub-G(1) population. 50 microM of MSC was able to induce apoptosis in 48% of cell population at a 24 h time point. Moreover, the release of cytochrome c from mitochondria and the activation of caspase-3 and caspase-9 were also observed. The measurement of ROS by dichlorofluorescein fluorescence revealed that dose- and time-dependent increase in ROS was induced by MSC. N-acetylcysteine, glutathione, and deferoxamine blocked cell death, DNA fragmentation, and ROS generation induced by MSC. Moreover, N-acetylcysteine effectively blocked caspase-3 activation and the increase of the sub-G(1) population induced by MSC. These results imply that ROS is a critical mediator of the MSC-induced apoptosis in HL-60 cells.

Inhibitory effect of selenite on invasion of HT1080 tumor cells

Selenium, an essential biological trace element, has been shown to reduce and prevent the incidence of cancer. Our previous studies have shown that selenite is involved in the chemoprevention of cancer and induction of apoptosis of cancer cells. In this study, we demonstrate that selenite also inhibits the invasion of tumor cells. Cancer cell invasion requires coordinated processes, such as changes in cell-cell and cell-matrix adhesion, degradation of the extracellular matrix, and cell migration. We found that selenite inhibited invasion of HT1080 human fibrosarcoma cells. Adhesion of HT1080 cells to the collagen matrix was also inhibited by treatment with selenite, but cell-cell interaction and cell motility were not affected by selenite. Moreover, selenite reduced expression of matrix metalloproteinase-2 and -9 and urokinase-type plasminogen activator, which are involved in matrix degradation, but increased a tissue inhibitor of metalloproteinase-1. This inhibitory effect of selenite on the protease expressions was mediated by the suppression of transcription factors, NF-kappaB and AP-1. However, selenate showed no remarkable effect on all the steps of cancer cell invasion.

Aberrant methylation of donor genome in cloned bovine embryos

Despite recent successes in cloning various animal species, the use of somatic cells as the source of donor nuclei has raised many practically relevant questions such as increased abortion rates, high birth weight and perinatal death. These anomalies may be caused by incomplete epigenetic reprogramming of donor DNA. Genome-wide demethylation occurs during early development, 'erasing' gamete-specific methylation patterns inherited from the parents. This process may be a prerequisite for the formation of pluripotent stem cells that are important for the later development. Here, we provide evidence that cloned bovine embryos may have impaired epigenetic reprogramming capabilities. We found highly aberrant methylation patterns in various genomic regions of cloned embryos. Cloned blastocysts closely resembled donor cells in their overall genomic methylation status, which was very different from that of normal blastocysts produced in vitro or in vivo. We found demethylation of the Bov-B long interspersed nuclear element sequence in normal embryos, but not in cloned embryos, in which the donor-type methylation was simply maintained during preimplantation development. There were also significant variations in the degree of methylation among individual cloned blastocysts. Our findings indicate that the developmental anomalies of cloned embryos could be due to incomplete epigenetic reprogramming of donor genomic DNA.

Inhibition mechanisms of bioflavonoids extracted from the bark of Pinus maritima on the expression of proinflammatory cytokines

The effect of bioflavonoids extracted from the bark of Pinus maritima, Pycnogenol (PYC), on gene expression of the proinflammatory cytokines interleukin-1beta (IL-1beta) and interleukin-2 (IL-2) were investigated in RAW 264.7 cells and Jurkat E6.1 cells, respectively. PYC exerted strong scavenging activities against reactive oxygen species (ROS) generated by H2O2 in RAW 264.7. In situ ELISA, immunoblot analysis, and competitive RT-PCR demonstrated that pretreatment of LPS-stimulated RAW 264.7 cells with PYC dose-dependently reduced both the production of IL-1beta and its mRNA levels. Furthermore, in the same cells, PYC blocked the activation of nuclear factor kappaB (NF-kappaB) and activator protein-1 (AP-1), two major transcription factors centrally involved in IL-1beta gene expression. Concordantly, pretreatment of the cells with PYC abolished the LPS-induced IkappaB degradation. We also investigated the effect of PYC on IL-2 gene expression in phorbol 12-myristate 13acetate plus ionomycin (PMA/Io)-stimulated human T-cell line Jurkat E6.1. PYC inhibited the PMA/Io-induced IL-2 mRNA expression. However, as demonstrated in a reporter gene assay system, the mechanism of IL-2 gene transcriptional regulation by PYC was different from the regulation of IL-1beta. PYC inhibited both NF-AT and AP-1 chloramphenicol acetyltransferase (CAT) activities in transiently transfected Jurkat E6.1, but not NF-kappaB CAT activity. We also found that PYC can destabilize PMA/Io-induced IL-2 mRNA by posttranscriptional regulation. All these results suggest that bioflavonids can be useful therapeutic agents in treating many inflammatory, autoimmune, and cardiovascular diseases based on its diverse action mechanisms.

Se-methylselenocysteine induces apoptosis through caspase activation in HL-60 cells

Apoptosis, a programmed process of cell suicide, has been proposed as the most plausible mechanism for the chemopreventive activities of selenocompounds. In our study, we found that Se-methylselenocysteine (MSC) induced apoptosis through caspase activation in human promyelocytic leukemia (HL-60) cells. Measurements of cytotoxicity, DNA fragmentation and apoptotic morphology revealed that MSC was more efficient at inducing apoptosis than selenite, but was less toxic. Moreover, MSC increased both the apoptotic cleavage of poly(ADP-ribose) polymerase (PARP) and caspase-3 activity, whereas selenite did not. We next examined whether caspases and serine proteases are required for the apoptotic induction by MSC. A general caspase inhibitor, z-VAD-fmk, dramatically decreased cytotoxicity in MSC-treated HL-60 cells and several other apoptotic features, such as, caspase-3 activation, the apoptotic DNA ladder, TUNEL-positive staining and the DNA double-strand break. Interestingly, a general serine protease inhibitor, AAPV-cmk, also effectively inhibited MSC-mediated cytotoxicity and apoptosis. These results demonstrate that MSC is a selenocompound that efficiently induces apoptosis in leukemia cells and that proteolytic machinery, in particular caspase-3, is necessary for MSC-induced apoptosis. On the other hand, selenite-induced cell death could be derived from necrosis rather than apoptosis, since selenite did not significantly induce several apoptotic phenomena, including the activation of caspase-3.

Effects of reactive oxygen species on proliferation of Chinese hamster lung fibroblast (V79) cells

Reactive oxygen species (ROS) have emerged as important signaling molecules in the regulation of various cellular processes. In our study, we investigated the effect of a wide range of ROS on Chinese hamster lung fibroblast (V79) cell proliferation. Treatment with H2O2 (100 microM), superoxide anion (generated by 1 mM xanthine and 1 mU/ml xanthine oxidase), menadione, and phenazine methosulfate increased the cell proliferation by approximately 50%. Moreover, a similar result was observed after partial inhibition of superoxide dismutase (SOD) and glutathione peroxidase. This upregulation of cell proliferation was suppressed by pretreatment with hydroxyl radical scavengers and iron chelating agents. In addition to ROS, treatment with exogenous catalase and SOD mimic (MnTMPyP) suppressed the normal cell proliferation. Short-term exposure of the cells to 100 microM H2O2 was sufficient to induce proliferation, which indicated that activation of the signaling pathway is important as an early event. Accordingly, we assessed the ability of H2O2 to activate mitogen-activated protein kinases (MAPK). Jun-N-terminal kinase (JNK) and p38 MAPK were both rapidly and transiently activated by 100 microM H2O2, with maximal activation 30 min after treatment. However, the activity of extracellular signal-regulated kinase (ERK) was not changed. Pretreatment with SB203580 and SB202190, specific inhibitors of p38 MAPK, reduced the cell proliferation induced by H2O2. The activation of both JNK and p38 MAPK was also suppressed by pretreatment with hydroxyl radical scavenger and iron chelating agents. Our results suggest that the trace metal-driven Fenton reaction is a central mechanism that underlies cell proliferation and MAPK activation.

Type D retrovirus Gag polyprotein interacts with the cytosolic chaperonin TRiC

The carboxy terminus-encoding portion of the gag gene of Mason-Pfizer monkey virus (M-PMV), the prototype immunosuppressive primate type D retrovirus, encodes a 36-amino-acid, proline-rich protein domain that, in the mature virion, becomes the p4 capsid protein. The p4 domain has no known role in M-PMV replication. We found that two mutants with premature termination codons that remove half or all of the p4 domain produced lower levels of stable Gag protein and of self-assembled capsids. Interestingly, yeast two-hybrid screening revealed that p4 specifically interacted with TCP-1gamma, a subunit of the chaperonin TRiC (TCP-1 ring complex). TRiC is a cytosolic chaperonin that is known to be involved in both folding and subunit assembly of a variety of cellular proteins. TCP-1gamma also associated with high specificity with the M-PMV pp24/16-p12 domain and human immunodeficiency virus p6. Moreover, in cells, Gag polyprotein associated with the TRiC chaperonin complex and this association depended on ATP hydrolysis. In the p4 truncation mutants, the Gag-TRiC association was significantly reduced. These results strongly suggest that cytosolic chaperonin TRiC is involved in Gag folding and/or capsid assembly. We propose that TRiC associates transiently with nascent M-PMV Gag molecules to assist in their folding. Consequently, properly folded Gag molecules carry out the intermolecular interactions involved in self-assembly of the immature capsid.

Intracoronary stent implantation in Jamaica. The initial experience

Intracoronary stent implantation resulted in the complete or near complete dilatation of high grade occlusions of the left anterior descending coronary arteries in the four patients in whom it was undertaken. Intracoronary stent implantation is a useful adjunct to Percutaneous Transluminal Angioplasty (PTCA) and is applicable in selected patients with symptomatic ischaemic heart disease in a developing country with limited health resources like Jamaica. This is so since financial data presented here document the significant savings this technique (when appropriately utilised) could realise compared to the use of balloon angioplasty alone.

Loss of p14ARF in tumor cells facilitates replication of the adenovirus mutant dl1520 (ONYX-015)

The adenovirus mutant dl1520 (ONYX-015) does not express the E1B-55K protein that binds and inactivates p53. This virus replicates in tumor cells with mutant p53, but not in normal cells with functional p53. Although intra-tumoral injection of dl1520 shows promising responses in patients with solid tumors, previous in vitro studies have not established a close correlation between p53 status and dl1520 replication. Here we identify loss of p14ARF as a mechanism that allows dl1520 replication in tumor cells retaining wild-type p53. We demonstrate that the re-introduction of p14ARF into tumor cells with wild-type p53 suppresses replication of dl1520 in a p53-dependent manner. Our study supports the therapeutic use of dl1520 in tumors with lesions within the p53 pathway other than mutation of p53.

Effect of bioflavonoids extracted from the bark of Pinus maritima on proinflammatory cytokine interleukin-1 production in lipopolysaccharide-stimulated RAW 264.7

Currently, bioflavonoids have been known to have strong antioxidant capacities, and a variety of efforts have been made to identify the utilities of bioflavonoids in treating various diseases based on their antioxidant capacities. The effects of bioflavonoids extracted from the bark of Pinus maritima Pycnogenol (PYC) on free radical formation, activation of redox sensitive transcription factors, as well as interleukin-1 beta (IL-1 beta) production were investigated in murine macrophage cell lines. PYC exerted strong scavenging activities against reactive oxygen species generated either by H(2)O(2) or PMA in RAW 264.7 and IC-21 cells, respectively. In situ ELISA, immunoblot analysis, and competitive RT-PCR demonstrated that PYC pretreatment of LPS-stimulated RAW 264.7 cells dose-dependently reduced both the production of IL-1 beta and its mRNA levels. Furthermore, in the same cells, PYC blocked the activation of nuclear factor kappa B (NF-kappa B) and activator protein-1 (AP-1), two major transcription factors centrally involved in IL-1 beta gene expression. When RAW 264.7 cells were stimulated with LPS, the inhibitor protein I kappa B largely disappeared from cytosolic fractions. However, pretreatment of the cells with PYC abolished the LPS-induced I kappa B degradation. These results suggest that PYC can inhibit the expression of the proinflammatory cytokine IL-1 by regulating redox-sensitive transcription factors. This study may support the possibility that bioflavonoids including PYC can be used as antiinflammatory and immunosuppressive drugs based on their radical scavenging activities.

Chlorophyllin suppression of lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells

Chlorophyllin (CHL), a water-soluble derivative of chlorophyll, functions as an anticarcinogen and antioxidant. In the present study, we investigated the effect of CHL on nitric oxide production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Treatment with CHL inhibited nitric oxide production in the LPS-stimulated RAW 264. 7 cells in a dose-related manner. Competitive RT-PCR analysis, using a DNA competitor as an internal standard, demonstrated that the treatment with 1, 10, and 50 microM CHL decreased LPS-induced iNOS mRNA expression in a concentration-dependent manner. Since the expression of the iNOS gene is mainly regulated by NF-kappaB, we then examined the effects of CHL on the NF-kappaB DNA binding activity, using an electrophoretic mobility shift assay. CHL down-regulated the NF-kappaB DNA binding on its cognate recognition site at the concentrations just noted. Employing a transfection and reporter gene expression system with p(NF-kappaB)(3)-chloramphenicol acetyl transferase (CAT), the treatment of CHL produced a dose-dependent inhibition of CAT activity in RAW 264.7 cells. Furthermore, CHL partially restored LPS-decreased IkappaBalpha, an inhibitory protein against NF-kappaB activation, in the cytosolic extract from the LPS-treated cells determined by immunoblot analysis. CHL also protected the hydroxyl radical-induced cytotoxicity in RAW 264.7 cells, indicating its antioxidant effect. These results suggest that CHL suppresses the nitric oxide production and iNOS mRNA expression mediated by the inhibition of NF-kappaB activation, and its action mechanism may be based on its antioxidant effect.

Effect of short interspersed element sequences on the integration and expression of a reporter gene in the preimplantation-stage mouse embryos

Based on the assumption that foreign DNA sequences may have increased chance of integration into the host genome if they are flanked by high copy-numbered genomic sequences such as SINEs (short interspersed elements), we investigated the integration frequency of Lac Z reporter gene flanked by a fused B1/B2 in an in vivo system using pronuclear microinjection technique in the mouse. The SINE-flanked DNA showed a 4-fold increased integration frequency of the reporter gene than the control DNA (63% vs. 16%). Moreover, the level of beta-galactosidase expression, estimated from the X-Gal staining intensity in transgenic embryos, was greatly higher in SINE-carrying DNA. These results suggest that the SINE sequences can serve a very useful tool in improving the efficiency of current transgenic animal technology.

Efficient integration of short interspersed element-flanked foreign DNA via homologous recombination

We investigated whether mouse short interspersed elements (SINEs) could influence the recombination frequency of foreign DNA. Vectors harboring a reporter gene in combinations of SINEs B1 and/or B2 or a portion of long interspersed element-1 were prepared and tested in vitro by a colony assay using HC11 murine mammary epithelial cells and in vivo by microinjection into fertilized mouse eggs. In transfected HC11 cells, the number of colonies surviving G418 selection increased by 3.5-fold compared with control when the reporter was flanked by fused B1-B2 sequences. Similar results were obtained from microinjection study; in fetuses 11.5 days post coitum, transgene positives in control and SINE-flanked vectors were 16 and 53%, respectively. Individual B1- and B2-harboring vectors showed equivalent activities with each other, as determined by the colony assay (2.8-fold versus 3.2-fold compared with control). We determined the contribution of homologous recombination to the SINE-mediated increase in integration frequency through a polymerase chain reaction-based strategy; in more than half of embryos transgenes underwent homologous recombinations involving B1 sequences. These results demonstrate that the SINE sequences can increase the integration rate of foreign DNA and that such an increase is most likely due to the enhancement of homologous recombination.

Inhibitory effects of chlorophyllin on 7,12-dimethylbenz[a]anthracene-induced bacterial mutagenesis and mouse skin carcinogenesis

Chlorophyllin (CHL), a water-soluble derivative of chlorophyll, has been used for the treatment of several abnormal human conditions without apparent toxicity. Recent studies have revealed that CHL has the excellent chemopreventive potential. In the present investigation, we have found the inhibitory activities of CHL against 7,12-dimethylbenz[a]anthracene (DMBA)-induced mutagenesis in Salmonella typhimurium TA100 and also on DMBA-initiated and 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-promoted mouse skin tumor formation. The incidence and the multiplicity of skin tumors were not significantly decreased in mice by a single topical application of CHL prior to the DMBA treatment, but there was a marked suppression of papillomagenesis in mice treated with CHL during the promotional stage. Furthermore, the formation of DMBA-induced papillomagenesis was reduced in all mice that had received CHL for 6 weeks following treatment with TPA for 6, 18 and 24 weeks. These results indicate that CHL can inhibit both tumor promotion and the progression of papillomagenesis in the two-stage mouse skin carcinogenesis induced by DMBA and TPA.

Induction of apoptosis by selenite and selenodiglutathione in HL-60 cells: correlation with cytotoxicity

Effects of selenite and selenodiglutathione, an initial metabolite of selenite, on the induction of apoptosis and cytotoxicity were investigated in human promyelocytic leukemia HL-60 cells. Treatment of selenite or selenodiglutathione resulted in concentration-dependent cytotoxicity, measured by lactate dehydrogenase leakage assay, and by tetrazolium salt reduction assay. Selenodiglutathione has been shown to exert more cytotoxic effect than selenite in both assay systems. Time-course study of cellular selenium uptake suggests that the higher cytotoxicity of selenodiglutathione be largely due to faster and greater selenium uptake rate. Treatment with selenite or selenodiglutathione also induced apoptosis in a dose-dependent manner, as detected by enzyme-linked immunosorbent assay and by DNA fragmentation assay. The dose-response data of apoptosis induced by selenite or selenodiglutathione were similar to those of cytotoxicity, implicating a relationship between the induction of apoptosis and cytotoxicity. Zn, which is a well-known inhibitor of apoptosis, dose-dependently blocked not only the induction of apoptosis, but also the membrane damage induced by selenium, corroborating this hypothesis. It was noted that the inhibition of apoptosis by Zn exerted little protective effect on cytotoxicity at higher concentrations of selenium, compared with a perfect protective effect at low concentration of selenium. These results suggest that cytotoxicity induced by selenium may be partially correlated with apoptosis.