Morbidly Obese Patients Have Similar Clinical Outcomes and Recovery Kinetics After Minimally Invasive Decompression

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To study the impact of class 2/3 obesity (body mass index, BMI >35) on outcomes following minimally invasive decompression.

SUMMARY OF BACKGROUND DATA

No previous study has analyzed the impact of class 2/3 obesity on outcomes following minimally invasive decompression.

METHODS

Patients who underwent primary minimally invasive decompression were divided into 4 cohorts based on their BMI: normal (BMI 18.5 to <25), overweight (25 to <30), class 1 obesity (30 to <35), and class 2/3 obesity (BMI >35). Outcome measures were: 1) intraoperative variables: operative time, estimated blood loss (EBL); 2) patient reported outcome measures (PROMs) (Oswestry Disability Index, ODI; Visual Analog Scale, VAS back and leg; 12-Item Short Form Survey Physical Component Score, SF-12 PCS); 3) global rating change (GRC), minimal clinically important difference (MCID), and patient acceptable symptom state (PASS) achievement rates; 4) return to activities; and 5) complication and reoperation rates.

RESULTS

838 patients were included (226 normal, 357 overweight, 179 class 1 obesity, 76 class 2/3 obesity). Class 1 and 2/3 obesity groups had significantly greater operative times compared to the other groups. Class 2/3 obesity group had worse ODI, VAS back and SF-12 PCS preoperatively, worse ODI, VAS back, VAS leg and SF-12 PCS at <6 months, and worse ODI and SF-12 PCS at >6 months. However, they had significant improvement in all PROMs at both postoperative timepoints and the magnitude of improvement was similar to other groups. No significant differences were found in MCID and PASS achievement rates, likelihood of betterment on the GRC scale, return to activities, and complication/reoperation rates.

CONCLUSIONS

Class 2/3 obese patients have worse PROMs pre- and post-operatively. However, they show similar improvement in PROMs, MCID and PASS achievement rates, likelihood of betterment, recovery kinetics, and complication/reoperation rates as other BMI groups following minimally invasive decompression.

Temporal Trends of Improvement After Minimally Invasive Transforaminal Lumbar Interbody Fusion

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

To analyze temporal trends in improvement after minimally invasive transforaminal lumbar interbody fusion (MIS TLIF).

SUMMARY OF BACKGROUND DATA

Although several studies have shown that patients improve significantly after MIS TLIF, evidence regarding the temporal trends in improvement is still largely lacking.

METHODS

Patients who underwent primary single-level MIS TLIF for degenerative conditions of the lumbar spine and had a minimum of 2-year follow-up were included. Outcome measures were: 1) patient reported outcome measures (PROMs) (Oswestry Disability Index, ODI; Visual Analog Scale, VAS back and leg; 12-Item Short Form Survey Physical Component Score, SF-12 PCS); 2) global rating change (GRC); 3) minimal clinically important difference (MCID); and 4) return to activities. Timepoints analyzed were preoperative, 2 weeks, 6 weeks, 3 months, 6 months, 1 year, and 2 years. Trends across these timepoints were plotted on graphs.

RESULTS

236 patients were included. VAS back and VAS leg were found to have statistically significant improvement compared to the previous timepoint up to 3 months after surgery. ODI and SF-12 PCS were found to have statistically significant improvement compared to the previous timepoint up to 6 months after surgery. Beyond these timepoints, there was no significant improvement in PROMs. 80% of patients reported feeling better compared to preoperative by 3 months. >50% of patients achieved MCID in all PROMs by 3 months. Most patients returned to driving, returned to work, and discontinued narcotics at an average of 21, 20, and 10 days, respectively.

CONCLUSIONS

Patients are expected to improve up to 6 months after MIS TLIF. Back pain and leg pain improve up to 3 months and disability and physical function improve up to 6 months. Beyond these timepoints, the trends in improvement tend to reach a plateau. 80% of patients feel better compared to preoperative by 3 months after surgery.

Practical Answers to Frequently Asked Questions in Anterior Cervical Spine Surgery for Degenerative Conditions

INTRODUCTION

Surgical counseling enables shared decision making and optimal outcomes by improving patients' understanding about their pathologies, surgical options, and expected outcomes. Here, we aimed to provide practical answers to frequently asked questions (FAQs) from patients undergoing an anterior cervical diskectomy and fusion (ACDF) or cervical disk replacement (CDR) for the treatment of degenerative conditions.

METHODS

Patients who underwent primary one-level or two-level ACDF or CDR for the treatment of degenerative conditions with a minimum of 1-year follow-up were included. Data were used to answer 10 FAQs that were generated from author's experience of commonly asked questions in clinic before ACDF or CDR.

RESULTS

A total of 395 patients (181 ACDF, 214 CDR) were included. (1, 2, and 3) Will my neck/arm pain and physical function improve? Patients report notable improvement in all patient-reported outcome measures. (4) Is there a chance I will get worse? 13% (ACDF) and 5% (CDR) reported worsening. (5) Will I receive a significant amount of radiation? Patients on average received a 3.7 (ACDF) and 5.5 mGy (CDR) dose during. (6) How long will I stay in the hospital? Most patients get discharged on postoperative day one. (7) What is the likelihood that I will have a complication? 13% (8% minor and 5% major) experienced in-hospital complications (ACDF) and 5% (all minor) did (CDR). (8) Will I need another surgery? 2.2% (ACDF) and 2.3% (CDR) of patients required a revision surgery. (9 & 10) When will I be able to return to work/driving? Most patients return to working (median of 16 [ACDF] and 14 days [CDR]) and driving (median of 16 [ACDF] and 12 days [CDR]).

CONCLUSIONS

The answers to the FAQs can assist surgeons in evidence-based patient counseling.

Erector Spinae Plane Block Reduces Immediate Postoperative Pain and Opioid Demand After Minimally Invasive Transforaminal Lumbar Interbody Fusion

STUDY DESIGN

Matched cohort comparison.

OBJECTIVE

To determine perioperative outcomes of erector spinae plane (ESP) block for minimally invasive transforaminal lumbar interbody fusion (MI-TLIF).

SUMMARY OF BACKGROUND DATA

There is a paucity of data on the impact of lumbar ESP block on perioperative outcomes and its safety in MI-TLIF.

MATERIALS AND METHODS

Patients who underwent 1-level MI-TLIF and received the ESP block (group E ) were included. An age and sex-matched control group was selected from a historical cohort that received the standard-of-care (group NE). The primary outcome of this study was 24-hour opioid consumption in morphine milligram equivalents. Secondary outcomes were pain severity measured by a numeric rating scale, opioid-related side effects, and hospital length of stay. Outcomes were compared between the two groups.

RESULTS

Ninety-eight and 55 patients were included in the E and NE groups, respectively. There were no significant differences between the two cohorts in patient demographics. Group E had lower 24-hour postoperative opioid consumption ( P = 0.117, not significant), reduced opioid consumption on a postoperative day (POD) 0 ( P = 0.016), and lower first pain scores postsurgery ( P < 0.001). Group E had lower intraoperative opioid requirements ( P < 0.001), and significantly lower average numeric rating scale pain scores on POD 0 ( P = 0.034). Group E reported fewer opioid-related side effects as compared with group NE, although this was not statistically significant. The average highest postoperative pain score within 3 hours postprocedurally was 6.9 and 7.7 in the E and NE cohorts, respectively ( P = 0.029). The median length of stay was comparable between groups with the majority of patients in both groups being discharged on POD 1.

CONCLUSIONS

In our retrospective matched cohort, ESP blocks resulted in reduced opioid consumption and decreased pain scores on POD 0 in patients undergoing MI-TLIF.

LEVEL OF EVIDENCE

Level 3.

Risk factors for failure to achieve minimal clinically important difference following cervical disc replacement

BACKGROUND CONTEXT

While cervical disc replacement (CDR) has been emerging as a reliable and efficacious treatment option for degenerative cervical spine pathology, not all patients undergoing CDR will achieve minimal clinically important difference (MCID) in patient-reported outcome measures (PROMs) postoperatively-risk factors for failure to achieve MCID in PROMs following CDR have not been established.

PURPOSE

To identify risk factors for failure to achieve MCID in Neck Disability Index (NDI, Visual Analog Scale (VAS) neck and arm following primary 1- or 2-level CDRs in the early and late postoperative periods.

STUDY DESIGN

Retrospective review of prospectively collected data.

PATIENT SAMPLE

Patients who had undergone primary 1- or 2-level CDR for the treatment of degenerative cervical pathology at a single institution with a minimum follow-up of 6 weeks between 2017 and 2022.

OUTCOME MEASURES

Patient-reported outcomes: Neck disability index (NDI), Visual analog scale (VAS) neck and arm, MCID.

METHODS

Minimal clinically important difference achievement rates for NDI, VAS-Neck, and VAS-Arm within early (within 3 months) and late (6 months to 2 years) postoperative periods were assessed based on previously established thresholds. Multivariate logistic regressions were performed for each PROM and evaluation period, with failure to achieve MCID assigned as the outcome variable, to establish models to identify risk factors for failure to achieve MCID and predictors for achievement of MCID. Predictor variables included in the analyses featured demographics, comorbidities, diagnoses/symptoms, and perioperative characteristics.

RESULTS

A total of 154 patients met the inclusion criteria. The majority of patients achieved MCID for NDI, VAS-Neck, and VAS-Arm for both early and late postoperative periods-79% achieved MCID for at least one of the PROMs in the early postoperative period, while 80% achieved MCID for at least one of the PROMs in the late postoperative period. Predominant neck pain was identified as a risk factor for failure to achieve MCID for NDI in the early (OR: 3.13 [1.10-8.87], p-value: .032) and late (OR: 5.01 [1.31-19.12], p-value: .018) postoperative periods, and VAS-Arm for the late postoperative period (OR: 36.63 [3.78-354.56], p-value: .002). Myelopathy was identified as a risk factor for failure to achieve MCID for VAS-Neck in the early postoperative period (OR: 3.40 [1.08-10.66], p-value: .036). Anxiety was identified as a risk factor for failure to achieve MCID for VAS-Neck in the late postoperative period (OR: 6.51 [1.91-22.18], p-value: .003). CDR at levels C5C7 was identified as a risk factor for failure to achieve MCID in NDI for the late postoperative period (OR: 9.74 [1.43-66.34], p-value: .020).

CONCLUSIONS

Our study identified several risk factors for failure to achieve MCID in common PROMs following CDR including predominant neck pain, myelopathy, anxiety, and CDR at levels C5-C7. These findings may help inform the approach to counseling patients on outcomes of CDR as the evidence suggests that those with the risk factors above may not improve as reliably after CDR.

Pilot Study on Percutaneous Delivery of Recombinant Human Bone Morphongenetic Protein-2 Augments Fusion in a Nicotine-impaired Rabbit Fusion Model

STUDY DESIGN

A nicotine-impaired spinal fusion rabbit model.

OBJECTIVE

To examine whether controlled delivery of morselized absorbable collagen sponge recombinant human bone morphogenetic protein-2 (rhBMP2) in a delayed manner postsurgery would allow for improved bone healing.

SUMMARY OF BACKGROUND DATA

The current delivery method of rhBMP-2 during surgery causes a burst of rhBMP-2, which is not sustained. Given that bone morphogenetic protein 2 (BMP-2) expression peaks later in the fusion process, there may be the benefit of delivery of rhBMP-2 later in the healing process.

METHODS

Sixteen male 1-year-old rabbits underwent a posterolateral spinal fusion with iliac crest bone graft at L5-L6 while being given nicotine to prevent spinal fusion as previously published. Eight were controls, whereas 8 had morselized rhBMP-2 (4.2 mg) injected at the fusion site at 4 weeks postoperatively. Histologic, radiologic, and palpation examinations were performed at 12 weeks to determine fusion status and the volume of bone formed. Hematoxylin and eosin stains were used for histology. A Student t test was used to compare the computed tomography scan measured volume of bone created between the control cohort (CC) and rhBMP-2 delayed delivery cohort (BMP-DDC).

RESULTS

Of the total, 7/8 rabbits in the BMP-DDC and 5/8 rabbits in the CC formed definitive fusion with a positive palpation examination, bridging bone between transverse processes on computed tomography scan, and an x-ray showing fusion. Histologic analysis revealed newly remodeled bone within the BMP-DDC. There was an increased average volume of bone formed within the BMP-DDC versus the CC (22.6 ± 13.1 vs 11.1 ± 3.6 cm 3 , P = 0.04).

CONCLUSION

Our study shows that injectable morselized absorbable collagen sponge/rhBMP-2 can create twice as much bone within a nicotine-impaired rabbit spine fusion model when delivered 4 weeks out from the time of surgery.

Surgeon Experience Influences Robotics Learning Curve for Minimally Invasive Lumbar Fusion: A Cumulative Sum Analysis

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

To analyze the learning curves of three spine surgeons for robotic minimally invasive transforaminal lumbar interbody fusion (MI-TLIF).

SUMMARY OF BACKGROUND DATA

Although the learning curve for robotic MI-TLIF has been described, the current evidence is of low quality with most studies being single-surgeon series.

MATERIALS AND METHODS

Patients who underwent single-level MI-TLIF with three spine surgeons (years in practice: surgeon 1: 4, surgeon 2: 16, and surgeon 3: two) using a floor-mounted robot were included. Outcome measures were operative time, fluoroscopy time, intraoperative complications, screw revision, and patient-reported outcome measures. Each surgeon's cases were divided into successive groups of 10 patients and compared for differences. Linear regression and cumulative sum (CuSum) analyses were performed to analyze the trend and learning curve, respectively.

RESULTS

A total of 187 patients were included (surgeon 1: 45, surgeon 2: 122, and surgeon 3: 20). For surgeon 1, CuSum analysis showed a learning curve of 21 cases with the attainment of mastery at case 31. Linear regression plots showed negative slopes for operative and fluoroscopy time. Both learning phase and postlearning phase groups showed significant improvement in patient-reported outcome measures. For surgeon 2, CuSum analysis demonstrated no discernible learning curve. There was no significant difference between successive patient groups in either operative time or fluoroscopy time. For surgeon 3, CuSum analysis demonstrated no discernible learning curve. Even though the difference between successive patient groups was not significant, cases 11 to 20 had an average operative time of 26 minutes less than cases 1-10), suggesting an ongoing learning curve.

CONCLUSIONS

Surgeons who are well-experienced can be expected to have no or minimal learning curve for robotic MI-TLIF. Early attendings are likely to have a learning curve of around 21 cases with the attainment of mastery at case 31. Learning curve does not seem to impact clinical outcomes after surgery.

LEVEL OF EVIDENCE

Level 3.

Floor-Mounted Robotic Pedicle Screw Placement in Lumbar Spine Surgery: An Analysis of 1,050 Screws

OBJECTIVE

To analyze the usage of floor-mounted robot in minimally invasive lumbar fusion.

METHODS

Patients who underwent minimally invasive lumbar fusion for degenerative pathology using floor-mounted robot (ExcelsiusGPS) were included. Pedicle screw accuracy, proximal level violation rate, pedicle screw size, screw-related complications, and robot abandonment rate were analyzed.

RESULTS

Two hundred twenty-nine patients were included. Most surgeries were primary single-level fusion. Sixty-five percent of surgeries had intraoperative computed tomography (CT) workflow, 35% had preoperative CT workflow. Sixty-six percent were transforaminal lumbar interbody fusion, 16% were lateral, 8% were anterior, and 10% were a combined approach. A total of 1,050 screws were placed with robotic assistance (85% in prone position, 15% in lateral position). Postoperative CT scan was available for 80 patients (419 screws). Overall pedicle screw accuracy rate was 96.4% (prone, 96.7%; lateral, 94.2%; primary, 96.7%; revision, 95.3%). Overall poor screw placement rate was 2.8% (prone, 2.7%; lateral, 3.8%; primary, 2.7%; revision, 3.5%). Overall proximal facet and endplate violation rates were 0.4% and 0.9%. Average diameter and length of pedicle screws were 7.1 mm and 47.7 mm. Screw revision had to be done for 1 screw (0.1%). Use of the robot had to be aborted in 2 cases (0.8%).

CONCLUSION

Usage of floor-mounted robotics for the placement of lumbar pedicle screws leads to excellent accuracy, large screw size, and negligible screw-related complications. It does so for screw placement in prone/lateral position and primary/revision surgery alike with negligible robot abandonment rates.

Cervical Steroid Injections Are Not Effective for Prevention of Surgical Treatment of Degenerative Cervical Myelopathy

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The objective of this study is to determine how often patients with degenerative cervical myelopathy (DCM) and initially treated with cervical steroid injections (CSI) and to determine whether these injections provide any benefit in delaying ultimate surgical treatment.

METHODS

All patients with a new diagnosis of DCM, without previous cervical spine surgery or steroid injections, were identified in PearlDiver, a large insurance database. Steroid injection and surgery timing was identified using Current Procedural Terminology (CPT) codes. Multivariate logistic regression identified associations with surgical treatment.

RESULTS

A total of 686 patients with DCM were identified. Pre-surgical cervical spine steroid injections were utilized in 244 patients (35.6%). All patients underwent eventual surgical treatment. Median time from initial DCM diagnosis to surgery was 75.5 days (mean 351.6 days; standard deviation 544.9 days). Cervical steroid injections were associated with higher odds of surgery within 1 year (compared to patients without injections, OR = 1.44, P < .001) and at each examined time point through 5 years (OR = 2.01, P < .001). In multivariate analysis comparing injection types, none of the 3 injection types were associated with decreased odds of surgery within 1 month of diagnosis.

CONCLUSIONS

While cervical steroid injections continue to be commonly performed in patients with DCM, there is an overall increased odds of surgery after any type of cervical injection. Therefore injections should not be used to prevent surgical management of DCM.

The Role of Intraoperative Neuromonitoring Modalities in Anterior Cervical Spine Surgery

Background: Intraoperative neuromonitoring (IONM) is frequently used during spine surgery to mitigate the risk of neurological injuries. Yet, its role in anterior cervical spine surgery remains controversial. Without consensus on which anterior cervical spine surgeries would benefit the most from IONM, there is a lack of standardized guidelines for its use in such procedures. Purpose: We sought to assess the alerts generated by each IONM modality for 4 commonly performed anterior cervical spinal surgeries: anterior cervical diskectomy and fusion (ACDF), anterior cervical corpectomy and fusion (ACCF), cervical disk replacement (CDR), or anterior diskectomy. In doing so, we sought to determine which IONM modalities (electromyography [EMG], motor evoked potentials [MEP], and somatosensory evoked potentials [SSEP]) are associated with alert status when accounting for procedure characteristics (number of levels, operative level). Methods: We conducted a retrospective review of IONM data collected by Accurate Neuromonitoring, LLC, a company that supports spine surgeries conducted by 400 surgeons in 8 states, in an internally managed database from December 2009 to September 2018. The database was queried for patients who underwent ACCF, ACDF, anterior CDR, or anterior diskectomy in which at least 1 IONM modality was used. The IONM modalities and incidence of alerts were collected for each procedure. The search identified 8854 patients (average age, 50.6 years) who underwent ACCF (n = 209), ACDF (n = 8006), CDR (n = 423), and anterior diskectomy (n = 216) with at least 1 IONM modality. Results: Electromyography was used in 81.3% (n = 7203) of cases, MEP in 64.8% (n = 5735) of cases, and SSEP in 99.9% (n = 8844) of cases. Alerts were seen in 9.3% (n = 671), 0.5% (n = 30), and 2.7% (n = 241) of cases using EMG, MEP and SSEP, respectively. In ACDF, a significant difference was seen in EMG alerts based on the number of spinal levels involved, with 1-level ACDF (6.9%, n = 202) having a lower rate of alerts than 2-level (10.0%, n = 272), 3-level (15.2%, n = 104), and 4-level (23.4%, n = 15). Likewise, 2-level ACDF had a lower rate of alerts than 3-level and 4-level ACDF. A significant difference by operative level was noted in EMG use for single-level ACDF, with C2-C3 having a lower rate of use than other levels. Conclusions: This retrospective review of anterior cervical spinal surgeries performed with at least 1 IONM modality found that SSEP had the highest rate of use across procedure types, whereas MEP had the highest rate of nonuse. Future studies should focus on determining the most useful IONM modalities by procedure type and further explore the benefit of multimodal IONM in spine surgery.

Intraoperative Neuromonitoring During Lateral Lumbar Interbody Fusion

Objective

To review the evidence for the use of electromyography (EMG), motor-evoked potentials (MEPs), and somatosensory-evoked potentials (SSEPs) intraoperative neuromonitoring (IONM) strategies during lateral lumbar interbody fusion (LLIF), as well as discuss the limitations associated with each technique.

Methods

A comprehensive review of the literature and compilation of findings relating to clinical studies investigating the efficacy of EMG, MEP, SSEP, or combined IONM strategies during LLIF.

Results

The evidence for the use of EMG is mixed with some studies demonstrating the efficacy of EMG in preventing postoperative neurologic injuries and other studies demonstrating a high rate of postoperative neurologic deficits with EMG monitoring. Multimodal IONM strategies utilizing MEPs or saphenous SSEPs to monitor the lumbar plexus may be promising strategies based on results from a limited number of studies.

Conclusion

The use of traditional EMG during LLIF remains without consensus. There is a growing body of evidence utilizing multimodal IONM with MEPs or saphenous SSEPs demonstrating a possible decrease in postoperative neurologic injuries after LLIF. Future prospective studies, with clear definitions of neurologic injury, that evaluate different multimodal IONM strategies are needed to better assess the efficacy of IONM during LLIF.

The association between spondylolisthesis and decreased muscle health throughout the lumbar spine for patients with operative lumbar spinal stenosis

PURPOSE

There are data underlining the relationship between muscle health and spine related pathology, but little data regarding changes in paralumbar muscle associated with lumbar spondylolisthesis. We aimed to define changes in paralumbar muscle health associated with spondylolisthesis.

METHODS

A retrospective review was performed on consecutive patients with lumbar spine pathology requiring an operation. A pre-operative lumbar MRI was analysed for muscle health measurements including lumbar indentation value (LIV), paralumbar cross-sectional area divided by body mass index (PL-CSA/BMI), and Goutallier classification of fatty atrophy. All measurements were taken from an axial slice of a T2-weighted image at lumbar disc spaces. Baseline health-related quality of life scores (HRQOLs), narcotic use and areas of stenosis were tracked. We performed Chi-square analyses and student's t test to determine statistically significant differences between cohorts.

RESULTS

There were 307 patients (average age 56.1 ± 16.7 years, 141 females) included within our analysis. 112 patients had spondylolisthesis. There were no differences in baseline HRQOLs between the spondylolisthesis cohort (SC) and non-spondylolisthesis cohort (non-SC). There were significantly worse PL-CSA/BMI at L2-L3 (p = 0.03), L3-L4 (p = 0.04) and L4-L5 (p = 0.02) for the SC. Goutallier classification of paralumbar muscle was worse for SC at L1-L2 (p = 0.04) and at L4-L5 (p < 0.001). Increased grade of spondylolisthesis was associated with worse PL-CSA at L1-L2 (p = 0.02), L2-L3 (p = 0.03) and L3-L4 (p = 0.05). Similarly, there were worse Goutallier classification scores associated with higher-grade spondylolisthesis at all levels (p < 0.05).

CONCLUSION

There are significant detrimental changes to paralumbar muscle health throughout the lumbar spine associated with spondylolisthesis.

The Use of Patient-Reported Outcomes Measurement Information System in Spine: A Systematic Review

BACKGROUND

The Patient-Reported Outcomes Measurement Information System (PROMIS) was developed to provide an easily administered patient-outcome questionnaire that was adaptable to a variety of medical and surgical subspecialties. Numerous authors have examined the effectiveness of PROMIS in various areas of spine surgery. Our goal was to systematically review PROMIS scores compared with legacy patient-reported outcomes measures (PROMs) in spinal surgery and spine pathology.

METHODS

A systematic search of the PubMed, EMBASE, and Cochrane databases using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines was performed, yielding 254 unique studies reporting on "PROMIS" in "spine." Each study was independently reviewed. A total of 16 studies were selected for inclusion.

RESULTS

The pooled sample size yielded a total of 4268 patients. In the cervical population, PROMIS physical function (PF; |r| = .47-.87, pain intensity (PIn; |r| = .61-.74), pain interference (PIf; |r| = .65-.88), and pain behavior (PB; |r| = .59-.74) correlated with the Neck Disability Index (NDI). PROMIS PF also strongly correlated with the modified Japanese Orthopaedic Association scale (mJOA; |r| = .61-.72). Among patients with lumbar pathology and adult spinal deformities, PROMIS PF (|r| = .53-.85), PIn (|r| = .73-.78), PIf (|r| = .59-.89), and PB (|r| = .58-.82) strongly correlated with the Oswestry Disability Index (ODI). PF (|r| = .51-.78), PIf (|r| = .60-.70), and anxiety (|r| = .73) also strongly correlated with the Scoliosis Research Society (SRS)-22 and SRS-30. When comparing measures of global health, PROMIS PF was strongly correlated with the Short Form (SF)-12 and SF-36 (|r| = .50-.85). On average, all PROMIS domains required less time to complete (49.6-56 seconds) than the ODI (176 seconds), NDI (190.3 seconds), SF-12 (214 seconds), and SF-36 physical function domains (99 seconds). The responsiveness of the PROMIS PF, PIf, and PB was comparable to that of legacy measures ODI, NDI, and SF-12.

CONCLUSIONS

The PROMIS PF, PIn, PIf, and PB demonstrated moderate to strong correlations with NDI, mJOA, ODI, SRS, and SF-12 measures in various populations of spine patients. All PROMIS domains had decreased time to completion and similar responsiveness compared with legacy measures.

LEVEL OF EVIDENCE

2.

CLINICAL RELEVANCE

These results highlight the potential of PROMIS as a valid and reliable tool to assess patient-reported outcomes in spinal surgery patients and support more widespread use of PROMIS in spine.

The current state of navigation in robotic spine surgery

The advent and widespread adoption of pedicle screw instrumentation prompted the need for image guidance in spine surgery to improve accuracy and safety. Although the conventional method, fluoroscopy, is readily available and inexpensive, concerns regarding radiation exposure and the drive to provide better visual guidance spurred the development of computer-assisted navigation. Contemporaneously, a non-navigated robotic guidance platform was also introduced as a competing modality for pedicle screw placement. Although the robot could provide high precision trajectory guidance by restricting four of the six degrees of freedom (DOF), the lack of real-time depth control and high capital acquisition cost diminished its popularity, while computer-assisted navigation platforms became increasingly sophisticated and accepted. The recent integration of real-time 3D navigation with robotic platforms has resulted in a resurgence of interest in robotics in spine surgery with the recent introduction of numerous navigated robotic platforms. The currently available navigated robotic spine surgery platforms include the ROSA Spine Robot (Zimmer Biomet Robotics formerly Medtech SA, Montpellier, France), ExcelsiusGPS^® (Globus Medical, Inc., Audubon, PA, USA), Mazor X spine robot (Medtronic Navigation Louisville, CO; Medtronic Spine, Memphis, TN; formerly Mazor Robotics, Caesarea, Israel) and TiRobot (TINAVI Medical Technologies, Beijing, China). Here we provide an overview of these navigated spine robotic platforms, existing applications, and potential future avenues of implementation.

Comparison of Multilevel Anterior Cervical Discectomy and Fusion Performed in an Inpatient Versus Outpatient Setting

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To evaluate differences in patient factors, procedural factors, early outcomes and safety in mutlilevel anterior cervical discectomy and fusion (ACDF) in the inpatient versus outpatient setting.

METHODS

Patient demographics, operative factors, and outcomes of multilevel ACDF performed in an inpatient and outpatient setting were compared using Fisher's exact test for categorical and Student's t test for continuous variables.

RESULTS

Fifty-seven patients had surgery on an outpatient and 46 on an inpatient basis. Inpatients were older (56.7 vs 52.2 years, P = .012) and had a higher ASA (American Society of Anesthesiologists) class (P = .002). Sixty percent of 2-level cases were outpatient surgeries, compared with 35% of 3-level cases (P = .042). Outpatients had shorter operative times (71.26 vs 83.59 minutes, P < .0001) and shorter lengths of stay (8.51 vs 35.76 hours, P < .0001), lower blood loss (33.04 vs 45.87 mL, P = .003), and fewer in-hospital complications (5.3% vs 37.0%, P < .0001). Outpatients had better early outcomes in terms of 6-week Neck Disability Index (NDI) (27.97 vs 37.59, P = .014), visual analogue scale (VAS) neck (2.92 vs 4.02, P = .044), and Short Form-12 Physical Health Score (SF-12 PHS) (35.66 vs 30.79, P = .008). However, these differences did not persist at 6 months.

CONCLUSIONS

The results of our study suggest that multilevel ACDF can be performed safely in the outpatient setting without an increased risk of complications compared with the inpatient setting in an appropriately selected patient. Specifically, patients' age, ASA class, and number of levels being fused should be taken into consideration. At our institution, ASA class 3, body mass index >40 kg/m², age >80 years, intubation time >2.5 hours, or not having a responsible adult with the patient warrant inpatient admission. Importantly, the setting of the surgery does not affect patient-reported outcomes.

Restoration of lumbar lordosis after minimally invasive transforaminal lumbar interbody fusion: a systematic review

BACKGROUND

Transforaminal lumbar interbody fusion (TLIF) is a well-accepted surgical technique for the treatment of degenerative spinal conditions and spinal deformity. The TLIF procedure can be performed open or using minimally invasive techniques. While several studies have found that minimally invasive TLIF (MI-TLIF) has advantages over open TLIF procedures with less blood loss, postoperative pain and hospital length of stay, opponents of the minimally invasive technique cite the lack of restoration of lumbar lordosis as a major drawback. With the increasing awareness of restoring sagittal alignment parameters in degenerative and deformity procedures, surgeons should understand the capabilities of different procedures to achieve surgical goals. To our knowledge, few studies have specifically studied the radiographic restoration of lumbar lordosis after MI-TLIF procedures. The purpose of this study was to perform a systematic review of the literature describing the sagittal lumbar radiographic parameter changes after MI-TLIF.

METHODS

Following PRISMA guidelines, systematic review was performed. With the assistance of a medical librarian, a highly-sensitive search strategy formulated on 1/19/2018 utilized the following search terms: "minimally invasive procedures," "transforaminal lumbar interbody fusion," "lumbar interbody fusion," "diagnostic imaging," "radiographs," "radiography," "x-rays," "lordosis," "lumbar vertebrae," "treatment," "outcome," and "lumbosacral" using Boolean operators 'AND' and 'OR'. Three databases were searched (PubMed/Medline, Embase, and Cochrane Library). An online system (www.covidence.org) was used to standardize article review. All studies were independently analyzed by two investigators and discrepancies mitigated by a third reviewer. Study selection for each cycle was Yes/No/Maybe. Cycles were: (1) (Title/Abstract); (2) (Full Text); (3) (Extraction). Inclusion criteria were: (1) All study designs, (2) MI-TLIF procedures, (3) Reporting total lumbar lordosis (LL) and/or segmental lordosis (SL) pre- and postoperatively. Exclusion criteria were: (1) non MI-TLIF procedures (ALIF, XLIF, LLIF, conventional TLIF, OLIF), (2) No reported LL or SL.

RESULTS

The search yielded 4,036 results with 836 duplicates leaving 3,200 studies for review. Cycle 1 eliminated 3,153 studies as irrelevant, thus, 47 were eligible for full-text review. Cycle 2 excluded 31 studies for No English full text (9), Oral/Poster (8), Wrong intervention/outcome (10), Duplicate listing (2), Full text not available (1), Literature review (1) resulting in 16 included studies. Study designs were: Randomized-controlled trial (3), Case series (6) and Retrospective (7). Mean # of subjects were 32.0 (range 8-95). Weighted-mean LL was 39.6°±9.2 (range 28-57) and postoperative LL was 45.0°±7.4 (range 36-67) with a LL post-pre difference of 5.2°±5.9 (range -7 to 15). Weighted-mean preoperative SL was 12.7°±4.3 (range 5-21) and postoperative SL was 15.0°±4.5 (range 5-22) with a SL post-pre difference of 2.1°±1.7 (range 0-8).

CONCLUSIONS

The current literature on MI-TLIF and restoration of LL/SL is limited to 16 published studies, 44% of which are retrospective. The published evidence supporting LL and SL restoration with MI-TLIF is sparse with variable results. This systematic review demonstrates the need for future high-level studies to fully elucidate the capabilities of MI-TLIF procedures for restoring lumbar and segmental lordosis.

Radiation Exposure in Minimally Invasive Transforaminal Lumbar Interbody Fusion: The Effect of the Learning Curve

Background

Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) has comparable fusion rates and outcomes to the open approach, though many surgeons avoid the technique due to an initial learning curve. No current studies have examined the learning curve of MI-TLIF with respect to fluoroscopy time and exposure. Our objective with this retrospective review was to therefore use a repeatable mathematical model to evaluate the learning curve of MI-TLIF with a focus on fluoroscopy time and exposure.

Methods

We conducted a retrospective review of single level, primary fusions performed by a single surgeon during his initial experience with minimally invasive spine surgery. Chronologic case number was plotted against variables of interest, and learning was identified as the point at which the instantaneous rate of change of a curve fit to the data set equaled the average rate of change of the data set.

Results

One hundred nine cases were reviewed. Proficiency in operative time was achieved at 38 cases with the first 38 requiring a median of 137 minutes compared to 104 minutes for the latter 71 cases (P < .0001). Mastery of fluoroscopy use occurred at case 51. The median fluoroscopy time for the first 51 cases was 2.8 minutes, which dropped to 2.1 minutes for cases 52 to 109 (P < .0001). The complication rate plateaued after 43 cases, with 3 of 11 total complications occurring in the latter 76 cases.

Conclusions

Our results demonstrate the most gradual learning occurred with respect to fluoroscopy time and exposure, and operative time improved the quickest.

Level of Evidence

IV.

Clinical Relevance

These findings may guide spine surgeon education and training in minimally invasive techniques, and help determine safe case loads for radiation exposure during the initial learning phase of the technique. The model used to identify the learning curve can also be applied to several fields and surgical techniques.

Predictive Factors and Rates of Fusion in Minimally Invasive Transforaminal Lumbar Interbody Fusion Utilizing rhBMP-2 or Mesenchymal Stem Cells

Background

Several fusion adjuncts exist to enhance fusion rates during minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). The objective of this study was to compare fusion rates in patients undergoing MI-TLIF with either rhBMP-2 or cellularized bone matrix (CBM).

Methods

We conducted a single surgeon retrospective cohort study of patients who underwent MI-TLIF with either rhBMP-2 or CBM placed in an interbody cage. Single and multilevel procedures were included. Fusion was assessed on computed tomography scans at 12-month follow-up by an independent, blinded, board-certified neuroradiologist. Fusion rates and rate of revision surgery were compared with a Fisher exact test between the 2 groups. A multivariate regression analysis was performed to identify patient factors that were predictive of radiographic nonunion after MI-TLIF.

Results

A total of 93 fusion levels in 78 patients were reviewed. Thirty-nine patients received CBM, and 39 patients received rhBMP-2. The patients receiving rhBMP-2 were older on average (61.4 vs 55.6, P = .03). The overall fusion rate was 68% in the CBM group (32/47 levels) and 78% in the rhBMP-2 group (36/46) (P = .35). Only preoperative hypertension was predictive of radiographic nonunion (odds ratio = 3.5, P = .05). There were 3 smokers in the CBM group and 4 smokers in the BMP group, and 1 in each group experienced radiographic pseudarthrosis. A total of 4 patients, 3 in the CBM group and 1 in the BMP group (P = .61), required revision for symptomatic pseudarthrosis. All of these patients had a single-level index procedure.

Conclusions

There were no differences in radiographic fusion and rate of revision surgery in patients who underwent MI-TLIF with either rhBMP-2 or CBM as fusion adjuncts.

Level of Evidence

3.

Clinical Relevance

Both rhBMP-2 and CBMs can be used as effective fusion adjuncts without any clear advantage of one over the other.

Comparison of Inpatient and Outpatient Preoperative Factors and Postoperative Outcomes in 2-Level Cervical Disc Arthroplasty

OBJECTIVE

The purpose of this study was to evaluate factors associated with inpatient admission following 2-level cervical disc arthroplasty (CDA). A secondary aim was to compare outcomes between those treated on an inpatient versus outpatient basis.

METHODS

Using data from the American College of Surgeons National Surgical Quality Improvement Program database, multivariate logistic regression analysis was used to assess the independent effect of each variable on inpatient or outpatient selection for surgery. Statistical significance was defined by p-values <0.05. The factors considered were age, sex, body mass index (BMI), smoking status, American Society of Anesthesiologists physical status classification, and comorbidities including hypertension, diabetes, history of dyspnea or chronic obstructive pulmonary disease, previous cardiac intervention or surgery, steroid usage, and history of bleeding. In addition, whether the operation was performed by an orthopedic or neurosurgical specialist was analyzed.

RESULTS

The number of 2-level CDA procedures increased from 6 cases reported in 2014 to 142 in 2016, although a statistically significant increase in the number of outpatient cases performed was not seen (p=0.2). The factors found to be significantly associated with inpatient status following surgery were BMI (p=0.019) and diabetes mellitus requiring insulin (p=0.043). There were no significant differences in complication and readmission rates between the inpatient and outpatient groups.

CONCLUSION

Patients undergoing inpatient 2-level CDA had significantly higher rates of obesity and diabetes requiring insulin than did patients undergoing the same procedure in the outpatient setting. With no difference in complication or readmission rates, 2-level CDA may be considered safe in the outpatient setting in appropriately selected patients.

Routine health check-ups: A boon or a burden?

Healthcare provider institutions in India now offer structured health check-up 'packages' for routine screening of common diseases. While some tests included within their ambit are in keeping with international and Indian recommendations, some are entirely unwarranted. Unnecessary and inappropriate screening tests may cause more harm than benefit. Besides financial and resource burden, there may be over-diagnosis and over-treatment, psychological distress due to false-positive test results, harm from invasive follow-up tests, and false reassurance due to false-negative test results. Clinicians must ensure a net benefit from tests and interventions in order to efficiently deliver preventive services. We reviewed current screening guidelines for cardiovascular disease and common cancers, and surveyed multiple 'packages' provided at 8 centres in Mumbai, India. We put forth our recommendations for routine health screening in asymptomatic adults in India.

Putative bacterial volatile-mediated growth in soybean (Glycine max L. Merrill) and expression of induced proteins under salt stress

AIMS

Plant root-associated rhizobacteria elicit plant immunity referred to as induced systemic tolerance (IST) against multiple abiotic stresses. Among multibacterial determinants involved in IST, the induction of IST and promotion of growth by putative bacterial volatile compounds (VOCs) is reported in the present study.

METHODS AND RESULTS

To characterize plant proteins induced by putative bacterial VOCs, proteomic analysis was performed by MALDI-MS/MS after exposure of soybean seedlings to a new strain of plant growth promoting rhizobacteria (PGPR) Pseudomonas simiae strain AU. Furthermore, expression analysis by Western blotting confirmed that the vegetative storage protein (VSP), gamma-glutamyl hydrolase (GGH) and RuBisCo large chain proteins were significantly up-regulated by the exposure to AU strain and played a major role in IST. VSP has preponderant roles in N accumulation and mobilization, acid phosphatase activity and Na(+) homeostasis to sustain plant growth under stress condition. More interestingly, plant exposure to the bacterial strain significantly reduced Na(+) and enhanced K(+) and P content in root of soybean seedlings under salt stress. In addition, high accumulation of proline and chlorophyll content also provided evidence of protection against osmotic stress during the elicitation of IST by bacterial exposure.

CONCLUSIONS

The present study reported for the first time that Ps. simiae produces a putative volatile blend that can enhance soybean seedling growth and elicit IST against 100 mmol l(-1) NaCl stress condition.

SIGNIFICANCE AND IMPACT OF THE STUDY

The identification of such differentially expressed proteins provide new targets for future studies that will allow assessment of their physiological roles and significance in the response of glycophytes to stresses. Further work should uncover more about the chemical side of VOC compounds and a detailed study about their molecular mechanism responsible for plant growth.

Refractory atrial fibrillation effectively treated with ranolazine

Atrial fibrillation is the most common sustained cardiac arrhythmia which is often troublesome to manage. Currently, rhythm and rate control medications are the mainstays of therapy. In 2 amiodarone-refractory highly symptomatic patients, an innovative approach using ranolazine, which selectively acts on Na+ channels and delays atrial depolarization, was tried successfully.

Effects of lycopene on protein expression in human primary prostatic epithelial cells

Clinical trials and animal studies have suggested that lycopene, the red carotenoid found in tomatoes, might be useful for the prevention of prostate cancer in the diet or as a dietary supplement through a variety of chemoprevention mechanisms. As most mechanism of action studies have used prostate cancer cells or males with existing prostate cancer, we investigated the effects of lycopene on protein expression in human primary prostatic epithelial cells. After treatment with lycopene at a physiologically relevant concentration (2 μmol/L) or placebo for 48 hours, the primary prostatic epithelial cells were lysed and fractionated using centrifugation into cytosolic/membrane and nuclear fractions. Proteins from lycopene-treated and placebo-treated cells were trypsinized and derivatized for quantitative proteomics using isobaric tags for relative and absolute quantitation (iTRAQ) reagent. Peptides were analyzed using two-dimensional microcapillary high-performance liquid chromatography-tandem mass spectrometry to identify proteins that were significantly upregulated or downregulated following lycopene exposure. Proteins that were most affected by lycopene were those involved in antioxidant responses, cytoprotection, apoptosis, growth inhibition, androgen receptor signaling, and the Akt/mTOR cascade. These data are consistent with previous studies suggesting that lycopene can prevent cancer in human prostatic epithelial cells at the stages of cancer initiation, promotion, and/or progression.

Tumor suppressor microRNAs, miR-100 and -125b, are regulated by 1,25-dihydroxyvitamin D in primary prostate cells and in patient tissue

MiR-100 and miR-125b are lost in many cancers and have potential function as tumor suppressors. Using both primary prostatic epithelial cultures and laser capture-microdissected prostate epithelium from 45 patients enrolled in a vitamin D3 randomized trial, we identified miR-100 and -125b as targets of 1,25-dihydroxyvitamin D3 (1,25D). In patients, miR-100 and -125b levels were significantly lower in tumor tissue than in benign prostate. Similarly, miR-100 and -125b were lower in primary prostate cancer cells than in cells derived from benign prostate. Prostatic concentrations of 1,25D positively correlated with these miRNA levels in both prostate cancer and benign epithelium, showing that patients with prostate cancer may still benefit from vitamin D3. In cell assays, upregulation of these miRNAs by 1,25D was vitamin D receptor dependent. Transfection of pre-miR-100 and pre-miR-125b in the presence or absence of 1,25D decreased invasiveness of cancer cell, RWPE-2. Pre-miR-100 and pre-miR-125b decreased proliferation in primary cells and cancer cells respectively. Pre-miR-125b transfection suppressed migration and clonal growth of prostate cancer cells, whereas knockdown of miR-125b in normal cells increased migration indicates a tumor suppressor function. 1,25D suppressed expression of previously bona fide mRNA targets of these miRNAs, E2F3 and Plk1, in a miRNA-dependent manner. Together, these findings show that vitamin D3 supplementation augments tumor suppressive miRNAs in patient prostate tissue, providing evidence that miRNAs could be key physiologic mediators of vitamin D3 activity in prevention and early treatment of prostate cancer.

miR-183-96-182 cluster is overexpressed in prostate tissue and regulates zinc homeostasis in prostate cells

Decreased zinc levels are a hallmark of prostate cancer tumors as zinc uniquely concentrates in healthy prostate tissue. Increased dietary zinc correlates with decreased risk of advanced prostate cancer and decreased mortality from prostate cancer. The mechanisms of prostatic zinc homeostasis are not known. Lower zinc levels in the tumor are correlated directly with decreased expression of the zinc transporter hZIP1. We report identification of a microRNA cluster that regulates multiple zinc transporters, including hZIP1. Screening in laser capture microdissected prostate cancer tumors identified miR-182 as a potential regulator of hZIP1. Regulation of hZIP1 by miR-182 via two binding sites was confirmed in primary prostate cell cultures. miR-96 and miR-183 are expressed as a cluster with miR-182 and share similar sequences. Array profiling of tissue showed that miR-183, -96, and -182 are higher in prostate cancer tissue compared with normal prostate. Overexpression of the entire miR-183-96-182 cluster suppressed five additional zinc transporters. Overexpression of miR-183, -96, and -182 individually or as a cluster diminished labile zinc pools and reduced zinc uptake, demonstrating this miR cluster as a regulator of zinc homeostasis. We observed regulation of zinc homeostasis by this cluster in prostate cells and HEK-293 cells, suggesting a universal mechanism that is not prostate-specific. To our knowledge, this is the first report of a miR cluster targeting a family of metal transport proteins. Individually or as a cluster, miR-183, -96, and -182 are overexpressed in other cancers too, implicating this miR cluster in carcinogenesis.

Pre-hospital thrombolysis

Coronary heart disease (CHD) is a major cause of mortality in India. Patients in India, who have acute coronary syndromes, have a higher rate of STEMI than do patients in developed countries. Since most of these patients are poor, they are less likely to get evidence-based treatments, and have a greater 30-day mortality. Reduction of delays in access to hospital and provision of affordable treatments could reduce this. Treatment regimes for AMI should aim to open the artery as soon as possible and as wide as possible. In patients suitable for thrombolytic treatment, time is critical and reperfusion should be initiated as soon as possible. Some adjunctive therapies are also beneficial, in particular, the antiplatelet agent aspirin, which should be given in the prehospital setting when a diagnosis of AMI is suspected. Despite availability of good treatment, mortality from AMI is showing no further reduction due to the prehospital phase and in-hospital delays. Thrombolysis is almost always delivered to patients after arriving in hospital, losing valuable time (and hence heart muscle). Newer drugs combined with recognition of improved outcomes have prompted attempts to decrease the time from symptom onset to treatment delivery via Pre Hospital Thrombolysis (PHT). However, PHT is significantly superior to in-hospital thrombolysis (IHT). This is especially important in regions where PCI is not available. In the RIKS-HIA and NRMI, PHT had better outcomes than IHT, but patients who received PPCI had lower mortality and re-infarction rates. They concluded that within 2 h of symptom onset, patients should receive PHT only if PPCI is not available within 4 h. In CAPTIM, which compared PPCI and PHT followed by PCI if thrombolysis failed and in GRACIA-1 trial, which tested the role of systematic PCI within 24 h of thrombolysis, the policy of systematic PCI following thrombolysis yielded better results than conservative management. The American Heart Association (AHA) and the American College of Cardiology (ACC) favour the use of PHT over PCI, placing the emphasis on the time factor rather than on the method of reperfusion. However, if PHT cannot be administered, the patient should be treated with PPCI within 90 min of first medical contact or therapy within 30 min such that the total ischaemic time is 120 min. The National Institute for Clinical Excellence supports reperfusion with fibrinolytics, recommending PHT using the newer agents, reteplase and tenecteplase, whose bolus application simplifies administration. PHT constitutes one of the means to shorten delays before the administration of reperfusion therapy. However, it poses several organizational problems that can find different answers according to each regional/national system of care. A number of barriers exist that limit the actual use of PHT. Thus the system of care chosen is likely to have a definite impact on the percentage of STEMI patients in whom PHT can be delivered.

Protection against cellular stress by 25-hydroxyvitamin D3 in breast epithelial cells

25-Hydroxyvitamin D(3) (25(OH)D(3)) is a prohormone and a major vitamin D metabolite. The discovery of (25(OH)D(3)) 1 alpha-hydroxylase in many vitamin D target organs has yielded an increased interest in defining the role(s) of 25(OH)D(3) in these tissues. The etiology of cancer appears to be complex and multi-factorial. Cellular stress (e.g., DNA damage, hypoxia, oncogene activation) has been identified as one of the key factors responsible for initiating the carcinogenesis process. In this study, we investigated whether 25(OH)D(3) protects breast epithelial cells from cellular stress using an established breast epithelial cell line MCF12F. To better elucidate the role of 25(OH)D(3) in the stress response, we used multiple in vitro stress models including serum starvation, hypoxia, oxidative stress, and apoptosis induction. Under all these stress conditions, 25(OH)D(3) (250 nmol/L) treatment significantly protected cells against cell death. Low-serum stress induced p53 expression accompanied with downregulation of PCNA, the presence of 25(OH)D(3) consistently inhibited the alteration of p53 and PCNA, suggesting that these molecules were involved in the stress process and may be potential target genes of 25(OH)D(3). miRNA microarray analysis demonstrated that stress induced by serum starvation caused significant alteration in the expression of multiple miRNAs including miR182, but the presence of 25(OH)D(3) effectively reversed this alteration. These data suggest that there is a significant protective role for 25(OH)D(3) against cellular stress in the breast epithelial cells and these effects may be mediated by altered miRNA expression.

Functionality of unliganded VDR in breast cancer cells: repressive action on CYP24 basal transcription

It is well-established that CYP24, an immediate target gene of VDR is upregulated by VDR ligands. This study is focused on the functional role of unliganded VDR by investigating the correlation between the expression of VDR protein and basal mRNA levels of CYP24 in breast cancer cell lines. Analyses of multiple breast cancer cell lines demonstrated an inverse correlation between VDR protein expression and CYP24 mRNA expression levels; while in the presence of ligand, VDR protein level was positively correlated with CYP24 expression. In MCF-7 cells, VDR was mainly distributed in the nuclei in the absence of ligand. VDR overexpression in MCF-7 cells and MDA-MB231 cells decreased CYP24 mRNA expression levels and CYP24 promoter activity. Conversely, knock-down of VDR using siRNA techniques in MCF-7 and T47D cells significantly increased CYP24 mRNA expression. We also found that overexpression of VDR with a polymorphic site (FokI-FF) at its AF-1 domain, which makes VDR shorter by three amino acids, failed to repress CYP24 promoter activity. This report provides conclusive evidence for the repressive action of unliganded VDR on the expression of its target gene CYP24 and the importance of an intact VDR AF-1 domain for its repressive action.

Abstract 4034: Disease- and race-related differences in microRNAs and zinc transporter 1 in human prostate tissue

Background:

Prostate cancer (PCa) is the second leading cause of male cancer related deaths. Zn has a protective role against cancer development: the normal peripheral zone glandular epithelium accumulates the mineral, whereas prostatic malignant cells do not. Human Zn transporter 1 (hZIP1) is an important protein involved in Zn accumulation. hZIP1 mRNA expression was shown to be down-regulated in PCa glands that still have intact hZIP1 DNA. Africans, who may have genetically down regulated their Zn absorption capacity in order to prevent toxicity due to high environmental concentrations, are disproportinally affected by PCa. miRNAs have emerged as an important class of post-transcriptional regulators of gene expression. Our hypothesis states that PCa cells express higher level of hZIP1-targeted miRNAs and that African-American patients have higher levels of hZIP1-targeted miRNAs as compared to matched Caucasians patients.

Design:

We identified putative miRNAs that target the 3′UTR of hZIP1 with bioinformatics and then compared them with published data sets showing miRNA changes that occur in PCa tissue. From this screen, we selected six miRNAs to test: miR-96, miR-223, miR-346, miR-30c, miR-100 and miR-182. We used laser-capture-microdissected (LCM) normal and tumor prostate tissues collected from 10 patients, five Caucasian-American and five African-American. MiRNA and mRNA levels were measured by qRT-PCR with Taqman™ assays. We compared the levels of hZIP1 specific miRNAs between African American and Caucasian in both normal and PCa samples.

Results:

In normal prostate tissues, 4 (miR-100, miR-182, miR-30 and miR-223) of the tested putative miRNAs showed a trend for elevated levels in African American patients as compared to Caucasians. In both races miR-30c, miR-346, and miR-223 levels were significantly lower in PCa samples when compared to normal tissues. Although the above putative hZIP1-targeted miRNAs were not increased in cancer, the hZIP1 mRNA was lower in the adenocarcinoma samples, confirming previous reports. MiR-182 was the only miRNA significantly increased in PCa in both Caucasian and African-American patients. Correlation studies revealed in fact that miR-182 had perfect inverse correlation with hZIP1 mRNA and the correlation was only present in the samples from Caucasian patients.

Conclusions

Our screen for putative hZIP1 specific miRNAs revealed miR-182 as a likely regulator of hZIP1 in human prostate. Ongoing experiments are validating hZIP1 as a miR-182 target in vitro. MiR-100, miR-30 and miR-223, although increased in African-Americans, did not show any correlation to hZIP1 mRNA. However, hZIP1 protein level may be affected and is currently being analyzed in our lab. If these miRNAs prove to be unrelated to hZIP1, they may still predispose this population group to PCa by regulating other mechanisms involved in carcinogenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4034.

Abstract 2066: Role of miR-182/miR-96 cluster in prostatic zinc homeostasis

Zinc has been shown to have a defensive action against the development of prostate cancer (PCa). Zinc is an essential element that is required for the activity of more than 300 enzymes, structure of proteins, and control of genetic expression. It plays an important role in cellular processes such as cell division, growth, differentiation, development, aging, and synthesis and repair of DNA, RNA, and protein. Prostatic secretary epithelial cells accumulate large amounts of zinc and have a high expression of human Zinc transporter 1 (hZIP1), the major zinc transporter in the prostate. PCa tissue exhibits lower levels of zinc and hZIP1 compared with surrounding normal-appearing areas. Furthermore, compared to Caucasian men, the prostates of African American men, a population with a disproportionately high risk of developing PCa, have decreased zinc and hZIP1. Previously, we examined several miRNAs in formalin-fixed paraffin-embedded prostate tissue from African American and Caucasian patients, of which miR-182/96 levels were higher in PCa samples and had inverse correlation with hZIP1 mRNA in Caucasian patients (Spearman rho = −0.77, p=0.009). No correlation between hZIP1 and miR-182 was found in the African-American specimens, suggesting a different mechanism for hZIP1 regulation in African-Americans. Based on previous studies, we hypothesize that miR-182/96 cluster is responsible for regulation of hZIP1 levels in PCa and prostate tissue. In this study, we examined the relationship between the levels of miR-182/96 and hZIP1 in more detail using cell culture models. We observed an inverse correlation between hZIP1 and miR-182 levels in several prostate cell cultures; primary normal epithelial cells, normal stromal cells, and prostate cancer cells (PC3 and LNCaP). MiR-182 is transcribed in a cluster with miR-96 and the miRNAs have an overlapping mRNA target sequence. As expected, miR-96 expression was identical to that of miR-182, thus also inversely correlated with hZIP1 in prostate cell cultures. Overexpression of miR-182 in both normal and LNCaP cells decreased hZIP1 mRNA levels, further implicating miR-182 as a regulator of zinc transport. Ongoing experiments focus on validating the two putative miR-182/96 binding sites in the 3′UTR of hZIP1 and the effect of miR-182 and miR-96 overexpression on zinc transport. Our results may establish a role for miR-182 in prostatic zinc homeostasis. Because zinc levels are linked to PCa risk, these miRNAs may be useful as a prognostic or diagnostic marker in prostate biopsies to identify patients with high risk of PCa recurrence and for identifying individuals for zinc replacement.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2066.

Abstract 2061: Vitamin D-regulates microRNAs in primary cultures of normal prostatic epithelial cells

Recent discoveries in cancer find that endogenous non-coding RNAs, microRNAs (miRNA), bind to the 3’ untranslated region of target mRNAs and function to translationally repress or decrease mRNA stability. Additionally, a number of studies show that aberrant miRNA expression is linked to various cancers, such as prostate cancer. Cancer-related changes in miRNA levels may result in either repression of tumor suppressor genes and/or activation of oncogenes. MiRNAs pose a potential role as targets in the treatment of cancers. In prostate cancer research, studies suggest a role of vitamin D as a chemopreventive agent. Vitamin D inhibits the growth and differentiation of malignant prostate cells and tumors. Studies show that a reduction in serum levels of vitamin D metabolites is linked to PC occurrence. Research from our laboratory shows that vitamin D treatment alters mRNA stability. This suggests a potential role for miRNAs in the vitamin D prevention of prostate cancer. We hypothesize that vitamin D's prevention of prostate cancer involves up-regulating tumor suppressive miRNAs and down-regulating oncogenic miRNAs. Using normal human prostatic epithelial cells as a model, we investigated the miRNA expression profile changes in cells that were treated with 1,25-dihydroxyvitamin D for time points ranging from 30 min to 24 hours. Our results demonstrated that approximately 50% of the miRNAs are expressed in the normal epithelial cells. A smaller percentage of miRNAs, approximately 10%, were changed by vitamin D treatment. We found that vitamin D down-regulated a small number of miRNAs (&lt;0.5 fold) commonly up-regulated in cancer (miR-181d, miR-378) and up-regulated miRNAs that are down-regulated in cancer (miR-29a, miR-16). Of the miRNAs altered by vitamin D, we observed an interesting down-regulation of the let-7 family of tumor suppressor miRNAs. Six of the seven let-7 family members present on the array (let-7 a-g) were down-regulated across the time points with four of the let-7 miRNAs downregulated as early as 30 minutes. This is a somewhat discrepant finding since let-7 is known as a tumor suppressor miRNA that is decreased in many cancers and we know that vitamin D is a cancer preventive agent. Further studies will determine the role of vitamin D on let-7 in the prostatic epithelial cells and the implications in cancer. Ongoing research will also determine the mechanism of vitamin D regulation of miRNAs to help further understand the chemopreventive role of vitamin D in prostate cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2061.

mRNA and micro-RNA expression analysis in laser-capture microdissected prostate biopsies: valuable tool for risk assessment and prevention trials

Diagnosis of prostate cancer (PCa) typically relies on needle biopsies, which are routinely archived in paraffin after formalin fixation and may contain valuable risk or prognostic information. The objective of this study was to determine the feasibility of mRNA and miRNA expression analysis in laser-capture microdissected (LCM) formalin-fixed paraffin-embedded archived prostate biopsies compared to the gold standard of frozen tissue. We analyzed the expression of compartment-specific and PCa-related genes in epithelial and stromal tissues collected from paired sets of archived prostate biopsies and frozen radical prostatectomy specimens from three patients. Our results showed appropriate compartment-specific and PCa-related expression with good within patient agreement between the FFPE biopsies and the frozen tissue. The potential for both mRNA and micro-RNA expression profiling in the biopsies was also demonstrated using PCR arrays which showed high correlation between the biopsy and frozen tissue, notwithstanding sensitivity limitations for mRNA detection in the FFPE specimen. This is the first study to compare RNA expression from biopsy and frozen tissues from the same patient and to examine miRNA expression in LCM-collected tissue from prostate biopsies. With careful technique and use of appropriate controls, RNA profiling from archived biopsy material is quite feasible showing high correlation to frozen tissue.

Abstract A69: mRNA and microRNA profiling of the microenvironment in prostate biopsies: Valuable tool for risk assessment and prevention trials

A69

Due to the widespread use of PSA testing, diagnosis of PCa typically relies on needle biopsies, which provide sparse, random sampling of the prostate. About 70-80% of these biopsies are negative for cancer, and the non-malignant tissue samples, which may contain valuable risk information, are routinely archived in paraffin after formalin fixation. Although RNA is degraded in formalin-fixed paraffin-embedded (FFPE) tissue, recent studies have shown that, with adequate attention to methodological detail, meaningful gene and microRNA (miRNA) expression data can be obtained from these specimens. We have optimized and validated several methods to overcome the challenges of working with prostate biopsies, which requires the ability to work with extremely limited amounts of material as well as the ability to isolate relatively homogeneous cell populations. miRNA signatures are rapidly being identified for many cancers including prostate cancer. Compared to mRNAs, miRNAs are highly stable in FFPE tissue due their small size, and thus may be ideal biomarkers in prostate biopsies. Epithelial and stromal tissues were collected from FFPE prostate biopsies by laser capture microdissection (LCM) from three patients. Tissue was LCM-collected in a similar manner from paired frozen tissue from the same patients. Total RNA was isolated and the expression of mRNA and miRNAs analyzed by qRT-PCR (mention PreAmp). Expression of 7 epithelial or stromal-specific genes (K18, PSA, NKX3.1, AMACR, IGF1, TIMP3, Desmin) showed agreement between the FFPE-biopsies and the frozen tissue in all three patients. Normal and PCa tissue was available for two patients. Expression of three PCa-related genes (PCA3, AMACR and NKX3.1) also showed agreement between the FFPE-biopsies and frozen tissue. As predicted, PCA3 and AMACR were elevated and NKX3.1 decreased in PCa relative to normal areas. Analysis of three miRNAs reported to be down-regulated in PCa (miR-125b, miR-22, miR-16) showed that these miRNAs have higher expression in the stromal compartment. However, normal epithelium and PCa showed similar levels of miRNA expression. The difference between our methodology and the previously published reports for these miRNAs and PCa is that we collected the tissue by LCM. This suggests that previous findings showing decreased expression of these miRNAs in PCa may be an artifact resulting from decreased stromal tissue in the PCa lesions. This is the first study to directly compare RNA expression from FFPE and frozen tissues from the same patient and also the first study to examine miRNA expression in LCM-collected tissue from prostate biopsies. We show that with this methodology, RNA profiling of mRNA and miRNA from FFPE-biopsy material is quite feasible. More importantly, in the small set of samples, RNA expression in the FFPE-biopsy was reflective of the whole prostate and the relative expression was similar to frozen material. Our goal is to apply this methodology to archival prostate biopsy banks in order to identify RNA markers predictive of PCa. These methods will also facilitate measurement of RNA markers in prostate cancer prevention clinical trials in which pre and post-biopsy material has been collected.

Citation Information: Cancer Prev Res 2008;1(7 Suppl):A69.

25-Hydroxyvitamin D3 is a natural chemopreventive agent against carcinogen induced precancerous lesions in mouse mammary gland organ culture

Despite the role of vitamin D(3) endocrine system in prevention of mammary gland transformation in animal models, use of 1,25(OH)(2)D(3 )in clinical settings is precluded due to its toxicity in vivo. Therefore much effort has been placed in developing relatively non-toxic vitamin D analogs. Recently, with the discovery of the expression of 25-hydroxy vitamin D(3) 1alpha-hydroxylase (CYP27B1) in multiple extrarenal organs, the functional role of prohormone, 25-hydroxyvitamin D(3) [25(OH)D(3)], has been redefined. Since 25(OH)D(3) does not cause hypercalcemia and maintains relative high concentration in serum, it is possible that the prohormone can be converted to active hormone in mammary epithelial cells to provide chemopreventive effects. In the present study, we evaluated its functional significance using mouse mammary organ culture (MMOC) system. We first showed that 25(OH)D(3) 1alpha-hydroxylase is extensively expressed in mammary ductal epithelial cells at both protein and mRNA levels, which is a prerequisite for 25(OH)D(3) to function in an autocrine/paracrine manner. However, we also observed that clotrimazol (1alpha-hydroxylase inhibitor) enhanced 25(OH)D(3) -induced CYP24 expression in breast cancer cells. In mammary glands derived from 1alpha-hydroxylase knockout mice, 25(OH)D(3) treatment in organ culture significantly induced CYP24 expression, indicating a potential direct effect of 25(OH)D(3). In MMOC, 100-250 nM 25(OH)D(3) suppressed both ovarian hormone-dependent and -independent mammary precancerous lesions (induced by DMBA) by more than 50%, while the active hormone 1,25(OH)(2)D(3) (positive control) at 100 nM suppressed alveolar lesions by more than 80%. The inactive vitamin D(3) (negative control) at 100 nM suppressed alveolar lesions by only 20% (P>0.05). We found that 25(OH)D(3) inhibits DMBA-induced mammary alveolar lesions (MAL) in a stage-specific manner: 25(OH)D(3) mainly inhibits the promotion stage of lesion formation. We conclude that 25(OH)D(3) could serve as a non-toxic natural chemopreventive agent for further development for breast cancer prevention.

Neural tube defects and congenital hydrocephalus in the Sultanate of Oman

A retrospective study was carried out in Oman to determine the incidence of neural tube defects (NTD) and congenital hydrocephalus (CH) and to identify any possible associations. National data retrieved from hospital records revealed the incidence of NTD in Oman to be comparatively low (1.25 per 1000), but the incidence of CH was much higher than that seen in Western Europe (0.44 per 1000) and was found to be associated with high rates of other congenital anomalies and neonatal death. There were no specific environmental factors associated with NTD and high environmental temperatures during the tropical desert summer (temperatures reach 48 degrees C) were excluded as a causative factor. In spina bifida families, later born children were more likely to be affected and there was also an association with increased maternal but not paternal age. Much higher consanguinity rates were noted in families with NTD and CH than in the general population.

Necrotizing fasciitis: a serious complication of omphalitis in neonates

Necrotizing fasciitis occurs when the inflammation (cellulitis) spreads beyond the umbilicus to include the subcutaneous tissue and underlying fascia. Presently, omphalitis is relatively uncommon because of aseptic delivery techniques and antimicrobial therapy. One hundred three neonates aged 7 to 28 days, with varying degrees of omphalitis, were treated on an outpatient or inpatient basis between 1989 and mid-1993. The neonates were full-term and weighed at least 2.5 kg. Patients with necrotizing fasciitis initially appear deceptively well, which results in less-than-optimum treatment at the outset, followed by a rapid and fulminating downhill course, in turn resulting in death within 24 to 72 hours. Early recognition of the condition, with aggressive resuscitation, appropriate antibiotics, and early surgery are necessary to salvage this high-risk group. The risk factors that may predict the development of necrotizing fasciitis and its early detection are discussed.