Single dose GLP toxicity and biodistribution study of a conditionally replicative adenovirus vector, CRAd-S-pk7, administered by intracerebral injection to Syrian hamsters.

BACKGROUND: CRAd-S-pk7 is a conditionally replicative oncolytic adenoviral vector that contains a survivin promoter and a pk7 fiber modification that confer tumor-specific transcriptional targeting and preferential replication in glioma while sparing the surrounding normal brain parenchyma. METHODS: This IND-enabling study performed under GLP conditions evaluated the toxicity and biodistribution of CRAd-S-pk7 administered as a single intracerebral dose to Syrian hamsters, a permissive model of adenoviral replication. Two hundred and forty animals were stereotactically administered either vehicle (n = 60) or CRAd-S-pk7 at 2.5 × 10(7), 2.5 × 10(8), or 2.5 × 10(9) viral particles (vp)/animal (each n = 60) on day 1. The animals were closely monitored for toxicology evaluation, assessment of viral distribution, and immunogenicity of CRAd-S-pk7. RESULTS: Changes in hematology, clinical chemistry, and coagulation parameters were minor and transient, and consistent with the inflammatory changes observed microscopically. These changes were considered to be of little toxicological significance. The vector remained localized primarily in the brain and to some degree in the tissues at the incision site. Low levels of vector DNA were detected in other tissues in a few animals suggesting systemic circulation of the virus. Viral DNA was detected in brains of hamsters for up to 62 days. However, microscopic changes and virus-related toxicity to the central nervous system were considered minor and decreased in incidence and severity over time. Such changes are not uncommon in studies using adenoviral vectors. CONCLUSION: This study provides safety and toxicology data justifying a clinical trial of CRAd-S-pk7 loaded in FDA-approved HB1.F3.CD neural stem cell carriers administered at the tumor resection bed in humans with recurrent malignant glioma.

Cell-Penetrating Peptide-Modified Gold Nanoparticles for the Delivery of Doxorubicin to Brain Metastatic Breast Cancer.

As therapies continue to increase the lifespan of patients with breast cancer, the incidence of brain metastases has steadily increased, affecting a significant number of patients with metastatic disease. However, a major barrier toward treating these lesions is the inability of therapeutics to penetrate into the central nervous system and accumulate within intracranial tumor sites. In this study, we designed a cell-penetrating gold nanoparticle platform to increase drug delivery to brain metastatic breast cancer cells. TAT peptide-modified gold nanoparticles carrying doxorubicin led to improved cytotoxicity toward two brain metastatic breast cancer cell lines with a decrease in the IC50 of at least 80% compared to free drug. Intravenous administration of these particles led to extensive accumulation of particles throughout diffuse intracranial metastatic microsatellites with cleaved caspase-3 activity corresponding to tumor foci. Furthermore, intratumoral administration of these particles improved survival in an intracranial MDA-MB-231-Br xenograft mouse model. Our results demonstrate the promising application of gold nanoparticles for improving drug delivery in the context of brain metastatic breast cancer.

Blood-brain barrier permeable gold nanoparticles: an efficient delivery platform for enhanced malignant glioma therapy and imaging.

The blood-brain barrier (BBB) remains a formidable obstacle in medicine, preventing efficient penetration of chemotherapeutic and diagnostic agents to malignant gliomas. Here, a transactivator of transcription (TAT) peptide-modified gold nanoparticle platform (TAT-Au NP) with a 5 nm core size is demonstrated to be capable of crossing the BBB efficiently and delivering cargoes such as the anticancer drug doxorubicin (Dox) and Gd(3+) contrast agents to brain tumor tissues. Treatment of mice bearing intracranial glioma xenografts with pH-sensitive Dox-conjugated TAT-Au NPs via a single intravenous administration leads to significant survival benefit when compared to the free Dox. Furthermore, it is demonstrated that TAT-Au NPs are capable of delivering Gd(3+) chelates for enhanced brain tumor imaging with a prolonged retention time of Gd(3+) when compared to the free Gd(3+) chelates. Collectively, these results show promising applications of the TAT-Au NPs for enhanced malignant brain tumor therapy and non-invasive imaging.

N-acetylcysteine amide augments the therapeutic effect of neural stem cell-based antiglioma oncolytic virotherapy.

Current research has evaluated the intrinsic tumor-tropic properties of stem cell carriers for targeted anticancer therapy. Our laboratory has been extensively studying in the preclinical setting, the role of neural stem cells (NSCs) as delivery vehicles of CRAd-S-pk7, a gliomatropic oncolytic adenovirus (OV). However, the mediated toxicity of therapeutic payloads, such as oncolytic adenoviruses, toward cell carriers has significantly limited this targeted delivery approach. Following this rationale, in this study, we assessed the role of a novel antioxidant thiol, N-acetylcysteine amide (NACA), to prevent OV-mediated toxicity toward NSC carriers in an orthotropic glioma xenograft mouse model. Our results show that the combination of NACA and CRAd-S-pk7 not only increases the viability of these cell carriers by preventing reactive oxygen species (ROS)-induced apoptosis of NSCs, but also improves the production of viral progeny in HB1.F3.CD NSCs. In an intracranial xenograft mouse model, the combination treatment of NACA and NSCs loaded with CRAd-S-pk7 showed enhanced CRAd-S-pk7 production and distribution in malignant tissues, which improves the therapeutic efficacy of NSC-based targeted antiglioma oncolytic virotherapy. These data demonstrate that the combination of NACA and NSCs loaded with CRAd-S-pk7 may be a desirable strategy to improve the therapeutic efficacy of antiglioma oncolytic virotherapy.

Nanoparticle-programmed self-destructive neural stem cells for glioblastoma targeting and therapy.

A 3-step glioblastoma-tropic delivery and therapy method using nanoparticle programmed self-destructive neural stem cells (NSCs) is demonstrated in vivo: 1) FDA-approved NSCs for clinical trials are loaded with pH-sensitive MSN-Dox; 2) the nanoparticle conjugates provide a delayed drug-releasing mechanism and allow for NSC migration towards a distant tumor site; 3) NSCs eventually undergo cell death and release impregnated MSN-Dox, which subsequently induces toxicity towards surrounding glioma cells.

Usefulness of minimum clinically important difference for assessing patients with subaxial degenerative cervical spine disease: statistical versus substantial clinical benefit.

BACKGROUND: The measurement of the therapeutic outcome of cervical spine surgeries commonly relies on four main patient reported outcomes (PROs): Neck Disability Index (NDI), Visual Analog Scale (VAS) for pain, and Short Form-36 (SF-36) Physical (PCS) and Mental (MCS) Component Summary. However, the clinical impact of such scores and how they could effectively measure therapeutic efficacy remains unclear. In this context, the concept of minimum clinically important difference (MCID) is developing into the standard by which to evaluate treatments, patient satisfaction and cost-effectiveness. METHODS: Eighty-eight consecutive patients undergoing surgery for subaxial degenerative cervical spine disease were selected from a prospective blinded database. PROs (NDI, PCS, MCS and VAS) were collected preoperatively, and together with blinded Surgeon Ratings (SR) at 3 months and 6 months post-surgery. Four anchor-based approaches were used to calculate different MCIDs. Three anchors (VAS, HTI (Health Transition Item of the SF-36) and SR) were used to evaluate surgery outcome. The best clinically and statistically relevant MCID was chosen. RESULTS: On average, all patients presented with a statistically significant improvement (p < 0.001) postoperatively for NDI (27.42 to 19.42), PCS (33.02 to 42.03), MCS (44 to 50.74) and VAS (2.85 to 1.93). The four MCID anchor-based approaches yielded a range of values for each PRO: 2.23-16.59 for PCS, 0.11-16.27 for MCS and 2.72-12.08 for NDI. When compared to the VAS and HTI anchors, the area under the ROC curve was greater for SR. This finding suggests that SR may be a more reliable anchor for MCID calculation. CONCLUSION: The MDC (minimum detectable change) approach together with the SR anchor appears to be the most appropriate MCID method. It offers the greatest area under the ROC curve (threshold above the 95 % CI), and the choice of the anchor did not significantly affect this result. MCID values for this dataset were 5.6 for PCS, 5.12 for MCS and 2.41 for NDI.

Comparison between patient and surgeon perception of degenerative spine disease outcomes--a prospective blinded database study.

BACKGROUND: Few have studied the correlation between patients' and spine surgeons' perception on outcomes, or compared these with patient-reported outcome scores. Outcomes studies are increasingly important in evaluating costs and benefits to patients and surgeons, and in developing metrics for payer evaluation and health care policy-making. OBJECTIVE: To compare patients' and surgeons' assessment of spine treatment outcome in a prospective blinded patient-driven spine surgery outcomes registry, and to correlate perceived outcomes ratings to validated outcomes scores. METHODS: Patients filled out surveys at baseline, 3 months and 6 months postoperatively, including Visual Analog Scale (VAS), and Neck Disability Index (NDI) or Oswestry Disability Index (ODI). Outcome was rated independently by patients and surgeons on a 7-point Likert-type scale. RESULTS: Two-hundred and sixty-five consecutive adult patients were surgical candidates. Of these, 154 (58.1 %) opted for surgery, with 69 (44.8 %) cervical and 85 (55.2 %) lumbar patients. One hundred and thirty-five (87.7 %) had both patient and surgeon postoperative ratings. Surgeons' and patients' ratings correlated strongly (Spearman rho = 0.53, p < 0.0001, 45.9 % identical, 88.2 % +/- 1 grade). The surgeon rated outcomes were better than patients in 29.8 % and worse in 21.15 %. Patient rating correlated better with the most recent NDI/ODI and pain scores than with incremental change from baseline. In multivariate analysis, age, location (cervical vs lumbar), pain ratings, and functional scores (NDI, ODI) did not have significant impact on the discrepancy between patient and surgeon ratings. CONCLUSIONS: Patients' and surgeons' global outcome ratings for spinal disease correlate highly. Patients' ratings correlate better with most recent functional scores, rather than incremental change from baseline.

Chemotherapeutic Stress Induces Transdifferentiation of Glioblastoma Cells to Endothelial Cells and Promotes Vascular Mimicry.

Glioblastoma (GBM) is the most common and aggressive primary malignant brain tumor affecting adults, with a median survival of approximately 21 months. One key factor underlying the limited efficacy of current treatment modalities is the remarkable plasticity exhibited by GBM cells, which allows them to effectively adapt to changes induced by anticancer therapeutics. Moreover, GBM tumors are highly vascularized with aberrant vessels that complicate the delivery of antitumor agents. Recent research has demonstrated that GBM cells have the ability to transdifferentiate into endothelial cells (ECs), illustrating that GBM cells may use plasticity in concert with vascularization leading to the creation of tumor-derived blood vessels. The mechanism behind this transdifferentiation, however, remains unclear. Here, we show that treatment with temozolomide (TMZ) chemotherapy induces time-dependent expression of markers for glioma stem cells (GSCs) and immature and mature ECs. In addition, GBM tumors growing as orthotopic xenografts in nude mice showed increased expression of GSC and EC markers after TMZ treatment. Ex vivo FACS analysis showed the presence of immature and mature EC populations. Furthermore, immunofluorescence analysis revealed increased tumor-derived vessels in TMZ-recurrent tumors. Overall, this study identifies chemotherapeutic stress as a new driver of transdifferentiation of tumor cells to endothelial cells and highlights cellular plasticity as a key player in therapeutic resistance and tumor recurrence.

Hitting a Moving Target: Glioma Stem Cells Demand New Approaches in Glioblastoma Therapy.

BACKGROUND: Glioblastoma multiforme (GBM) continues to devastate patients and outfox investigators and clinicians despite the preponderance of research directed at its biology, pathogenesis and therapeutic advances. GBM routinely outlasts multidisciplinary treatment protocols, almost inevitably recurring in a yet more aggressive and resistant form with distinct genetic differences from the original tumor. Attempts to glean further insight into GBM point increasingly toward a subpopulation of cells with a stem-like phenotype. These cancer stem cells, similar to those now described in a variety of malignancies, are capable of tumorigenesis from a population of susceptible cells. CONCLUSIONS: Glioma stem cells have thus become a prevalent focus in GBM research for their presumed role in development, maintenance and recurrence of tumors. Glioma stem cells infiltrate the white matter surrounding tumors and often evade resection. They are uniquely suited both biochemically and environmentally to resist the best therapy currently available, intrinsically and efficiently resistant to standard chemo- and radiotherapy. These stem cells create an extremely heterogenous tumor that to date has had an answer for every therapeutic question, with continued dismal patient survival. Targeting this population of glioma stem cells may hold the long-awaited key to durable therapeutic efficacy in GBM.

Viral Vector Production: Adenovirus.

Adenoviral vectors have proven to be valuable resources in the development of novel therapies aimed at targeting pathological conditions of the central nervous system, including Alzheimer's disease and neoplastic brain lesions. Not only can some genetically engineered adenoviral vectors achieve remarkably efficient and specific gene delivery to target cells, but they also may act as anticancer agents by selectively replicating within cancer cells.Due to the great interest in using adenoviral vectors for various purposes, the need for a comprehensive protocol for viral vector production is especially apparent. Here, we describe the process of generating an adenoviral vector in its entirety, including the more complex process of adenoviral fiber modification to restrict viral tropism in order to achieve more efficient and specific gene delivery.

Dedifferentiation of Glioma Cells to Glioma Stem-like Cells By Therapeutic Stress-induced HIF Signaling in the Recurrent GBM Model.

Increasing evidence exposes a subpopulation of cancer cells, known as cancer stem cells (CSCs), to be critical for the progression of several human malignancies, including glioblastoma multiforme. CSCs are highly tumorigenic, capable of self-renewal, and resistant to conventional therapies, and thus considered to be one of the key contributors to disease recurrence. To elucidate the poorly understood evolutionary path of tumor recurrence and the role of CSCs in this process, we developed patient-derived xenograft glioblastoma recurrent models induced by anti-glioma chemotherapy, temozolomide. In this model, we observed a significant phenotypic shift towards an undifferentiated population. We confirmed these findings in vitro as sorted CD133-negative populations cultured in differentiation-forcing media were found to acquire CD133 expression following chemotherapy treatment. To investigate this phenotypic switch at the single-cell level, glioma stem cell (GSC)-specific promoter-based reporter systems were engineered to track changes in the GSC population in real time. We observed the active phenotypic and functional switch of single non-stem glioma cells to a stem-like state and that temozolomide therapy significantly increased the rate of single-cell conversions. Importantly, we showed the therapy-induced hypoxia-inducible factors (HIF) 1α and HIF2α play key roles in allowing non-stem glioma cells to acquire stem-like traits, as the expression of both HIFs increase upon temozolomide therapy and knockdown of HIFs expression inhibits the interconversion between non-stem glioma cells and GSCs post-therapy. On the basis of our results, we propose that anti-glioma chemotherapy promotes the accumulation of HIFs in the glioblastoma multiforme cells that induces the formation of therapy-resistant GSCs responsible for recurrence. Mol Cancer Ther; 15(12); 3064-76. ©2016 AACR.

Analysis of survival in pediatric high-grade brainstem gliomas: A population-based study.

BACKGROUND: The purpose of this study was to use the National Cancer Institutes' Surveillance, Epidemiology, and End Results (SEER) database to perform a large-scale analysis of brainstem anaplastic astrocytoma (AA) and glioblastoma multiforme (GBM). Use of the SEER database gave us a larger sample size of this rare tumor type, allowing for the analysis of the relationship between prognostic factors and survival. MATERIALS AND METHODS: We selected pediatric patients (<18 years old) from the SEER database with histologically confirmed diagnoses of primary high-grade gliomas (World Health Organization Grade III/IV) of the brainstem. In univariate and multivariate analysis, we analyzed the relationship between demographic (age, gender, race, diagnosis date), histologic (AA, GBM), and treatment (surgery, radiation) factors on survival. RESULTS: In our cohort of 124 patients, those with AA had a median survival of 13 months and those with GBM 9 months. Higher-grade tumors were associated with statistically significantly increased mortality (hazard ratio [HR]: 1.74, confidence intervals [CIs]: 1.17-2.60). Surgical intervention was associated with a significantly lower mortality, either alone (HR: 0.14, CI: 0.04-0.5) or in combination with radiation (HR: 0.35, CI: 0.15-0.82). Radiation therapy alone was significantly associated with decreased mortality within the first 9 months after diagnosis but not with overall mortality. No demographic characteristics were significantly associated with mortality. CONCLUSIONS: Outcome remains poor in the pediatric high-grade brainstem glioma population. Survival is correlated with lower-grade tumor histology, radiation therapy only in the first 9 months after diagnosis, and surgical resection.

The relationship between obesity and symptomatic Chiari I malformation in the pediatric population.

BACKGROUND: Concomitant with the rise in childhood obesity in the United States is an increase in the diagnosis of Chiari I malformation (CM1). OBJECTIVE: To discern a correlation between obesity and CM1, defined as >5 mm of cerebellar tonsillar descent on sagittal magnetic resonance imaging. METHODS: Charts of CM1 patients aged 2-20 years were retrospectively reviewed. Chiari size, age, body mass index (BMI), and CM1 signs/symptoms were recorded. Patients were stratified by age: 2-9, 10-14, and 15-20 years. Mixed-effect linear models and linear regression analysis were applied to investigate the relationship between BMI-for-age percentiles and CM1 signs/symptoms. RESULTS: One hundred sixty-seven patients were included (mean age 14.5 ± 2.97 years, BMI 22.98 ± 6.5, and Chiari size 12.27 mm ± 5.91). When adjusted for age, 42% were overweight or obese-higher than normative BMI for children in the studied area (29.6%). When stratified by age, patients between 2 and 9 years were most commonly obese and presented the highest mean BMI (25.66), largest Chiari size (13.58), and highest incidence of headache (75%) and syringomyelia (66.67%). Patients between 15 and 20 years were most commonly overweight and presented the smallest Chiari size (11.76 mm), but the highest incidence of cerebellar (50%) and brainstem (8.55%) compression symptoms. A significant positive correlation existed between BMI and headache in the first two age groups: (R (2): 0.36, P = 0.03; R (2): 0.39, P = 0.01, respectively). Obese patients had higher incidence of headache in the 10-14 group (R (2): 0.37, P = 0.02) and the largest Chiari size in the 15-20 group (R (2): 0.40, P = 0.03). CONCLUSIONS: The pediatric CM1 population is more likely to be overweight or obese. Younger obese patients presented the highest incidence of Chiari-related headache symptoms, and older obese patients, the highest incidence of findings other than headache. Thus, body weight and age should be considered when evaluating children with CM1.

The role of glioma stem cells in chemotherapy resistance and glioblastoma multiforme recurrence.

Glioma stem cells (GSCs) constitute a slow-dividing, small population within a heterogeneous glioblastoma. They are able to self-renew, recapitulate a whole tumor, and differentiate into other specific glioblastoma multiforme (GBM) subpopulations. Therefore, they have been held responsible for malignant relapse after primary standard therapy and the poor prognosis of recurrent GBM. The failure of current therapies to eliminate specific GSC subpopulations has been considered a major factor contributing to the inevitable recurrence in GBM patients after treatment. Here, we discuss the molecular mechanisms of chemoresistance of GSCs and the reasons why complete eradication of GSCs is so difficult to achieve. We will also describe the targeted therapies currently available for GSCs and possible mechanisms to overcome such chemoresistance and avoid therapeutic relapse.

Minimally Invasive Transforaminal Lumbar Interbody Fusion (TLIF) for Spondylolisthesis in 282 Patients: In Situ Arthrodesis versus Reduction.

OBJECTIVE: The benefits of spondylolisthesis reduction via minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) remain poorly understood. The purpose was to compare the complications, perioperative factors, and fusion rates in patients undergoing MI-TLIF for degenerative spondylolisthesis between those in whom reduction was or was not performed. INCLUSION CRITERIA: 1) patients who underwent a 1, 2, or 3 level MI-TLIF and 2) had a preoperative diagnosis of degenerative spondylolisthesis (Meyerding grade >0). EXCLUSION CRITERIA: >10° coronal curves, significant sagittal malalignment, infection, and preoperative hardware failure. Patients were grouped on the basis of those who underwent reduction of the spondylolisthesis by at least 1 Meyerding grade (RED) and those who did not (NORED). RESULTS: A total of 282 patients were included: RED (162, 57.4%) and NORED (120, 42.6%). Mean ages (61.68 ± 10.43 vs. 61.88 ± 11.76 years, respectively, P > 0.05) and operative times (P > 0.05) were statistically similar. RED had a significantly larger EBL (280.2 ± 24.03 vs. 212.61 ± 17.54, P < 0.05). The length of hospital stay, intraoperative complications, postoperative medical and surgical complications, and disposition were statistically similar between groups (P > 0.05, for all). RED had a significantly higher percentage of patients with a successful fusion at 1 year than NORED (84.50% vs. 70.83%, P < 0.05). CONCLUSION: Reduction of spondylolisthesis was not associated with an increase in operative time, length of stay, and perioperative and postoperative complications compared with fusion in situ. Reduction was associated with higher blood loss but also a higher rate of fusion success at 1 year. Overall, reduction did not incur additional risk and had positive perioperative outcomes.

MMP14 as a novel downstream target of VEGFR2 in migratory glioma-tropic neural stem cells.

Neural stem cell (NSC)-based carriers have been presented as promising therapeutic tools for the treatment of infiltrative brain tumors due to their intrinsic tumor homing property. They have demonstrated the ability to migrate towards distant tumor microsatellites and effectively deliver the therapeutic payload, thus significantly improving survival in experimental animal models for brain tumor. Despite such optimistic results, the efficacy of NSC-based anti-cancer therapy has been limited due to the restricted tumor homing ability of NSCs. To examine this issue, we investigated the mechanisms of tumor-tropic migration of an FDA-approved NSC line, HB1.F3.CD, by performing a gene expression analysis. We identified vascular endothelial growth factor-A (VEGFA) and membrane-bound matrix metalloproteinase (MMP14) as molecules whose expression are significantly elevated in migratory NSCs. We observed increased expression of VEGF receptor 2 (VEGFR2) in the focal adhesion complexes of migratory NSCs, with downstream activation of VEGFR2-dependent kinases such as p-PLCγ, p-FAK, and p-Akt, a signaling cascade reported to be required for cellular migration. In an in vivo orthotopic glioma xenograft model, analysis of the migratory trail showed that NSCs maintained expression of VEGFR2 and preferentially migrated within the perivascular space. Knockdown of VEGFR2 via shRNAs led to significant downregulation of MMP14 expression, which resulted in inhibited tumor-tropic migration. Overall, our results suggest, the involvement of VEGFR2-regulated MMP14 in the tumor-tropic migratory behavior of NSCs. Our data warrant investigation of MMP14 as a target for enhancing the migratory properties of NSC carriers and optimizing the delivery of therapeutic payloads to disseminated tumor burdens.

Intraoperative and perioperative complications in minimally invasive transforaminal lumbar interbody fusion: a review of 513 patients.

OBJECT Transforaminal lumbar interbody fusion (TLIF) has become one of the preferred procedures for circumferential fusion in the lumbar spine. Over the last decade, advances in surgical techniques have enabled surgeons to perform the TLIF procedure through a minimally invasive approach (MI-TLIF). There are a few studies reported in the medical literature in which perioperative complication rates of MI-TLIF were evaluated; here, the authors present the largest cohort series to date. They analyzed intraoperative and perioperative complications in 513 consecutive MI-TLIF-treated patients with lumbar degenerative disc disease. METHODS The authors performed a retrospective review of prospectively collected data on 513 consecutive patients treated over a 10-year period for lumbar degenerative disc disease using MI-TLIF. All patients undergoing either a first-time or revision 1- or 2-level MI-TLIF procedure were included in the study. Demographic, intraoperative, and perioperative data were collected and analyzed using bivariate analyses (Student t-test, analysis of variance, odds ratio, chi-square test) and multivariate analyses (logistic regression). RESULTS A total of 513 patients underwent an MI-TLIF procedure, and the perioperative complication rate was 15.6%. The incidence of durotomy was 5.1%, and the medical and surgical infection rates were 1.4% and 0.2%, respectively. A statistically significant increase in the infection rate was seen in revision MI-TLIF cases, and the same was found for the perioperative complication rate in multilevel MI-TLIF cases. Instrumentation failure occurred in 2.3% of the cases. After analysis, no statistically significant difference was seen in the rates of durotomy during revision and multilevel surgeries. There was no significant difference between the complication rates when stratified according to presenting diagnosis. CONCLUSIONS To the authors' knowledge, this is the largest study of perioperative complications in MI-TLIF in the literature. A total of 513 patients underwent MI-TLIF (perioperative complication rate 15.6%). The most common complication was a durotomy (5.1%), and there was only 1 surgical wound infection (0.2%). There were significantly more perioperative infections in revision MI-TLIF cases and more perioperative complications in multilevel MI-TLIF cases. The results of this study suggest that MI-TLIF has a similar or better perioperative complication profile than those documented in the literature for open-TLIF treatment of degenerative lumbar spine disease.

Measuring surgical outcomes in subaxial degenerative cervical spine disease patients: minimum clinically important difference as a tool for determining meaningful clinical improvement.

BACKGROUND: Although the concept of minimum clinically important difference (MCID) as a measurement of surgical outcome has been extensively studied, there is lack of consensus on the most valid or clinically relevant MCID calculation approach. OBJECTIVE: To compare the range of MCID threshold values obtained by different anchor-based and distribution-based approaches to determine the best clinically meaningful and statistically significant MCID for our studied group. METHODS: Eighty-eight consecutive patients undergoing surgery for subaxial degenerative cervical spine disease were analyzed from a prospective blinded database. Preoperative, 3-, and 6-month postoperative patient reported outcome (PRO) scores and blinded surgeon ratings were collected. Four calculation methods were used to calculate MCID threshold values: average change, change difference, minimum detectable change, and receiver operating characteristic (ROC) curve. Three anchors were used to evaluate meaningful improvement postsurgery: health transition item, patient overall status, and surgeon ratings. RESULTS: On average, all patients had a statistically significant improvement (P < .001) postoperatively for neck disability index (score 27.42 preoperatively to 19.42 postoperatively), physical component of the Short Form of the Medical Outcomes Study (SF-36) (33.02-42.23), mental component of the SF-36 (44-50.74), and visual analog scale (2.85-1.93). The 4 MCID approaches yielded a range of values for each PRO: 2.23 to 16.59 for physical component of the SF-36, 0.11 to 16.27 for mental component of the SF-36, and 2.72 to 12.08 for neck disability index. In comparison with health transition item and patient overall status anchors, the area under the ROC curve was consistently greater for surgeon ratings for all 4 PROs. CONCLUSION: Minimum detectable change together with surgeon ratings anchor appears to be the most appropriate MCID method. Based on our findings, this combination offers the greatest area under the ROC curve (threshold above the 95% confidence interval). The choice of the anchor did not significantly affect this result.

The impact of obesity on surgeon ratings and patient-reported outcome measures after degenerative cervical spine disease surgery.

OBJECTIVE: Obesity is a growing public health problem. A considerable number of patients undergoing cervical spine surgery are obese, but the correlation between obesity and surgical outcome is still unclear. In this study, we investigated the impact of body mass index (BMI) on patients' and surgeons' perception of spine surgery outcomes. METHODS: We analyzed a prospectively collected spine surgery registry with patient-reported outcome measures and surgeon ratings. Mixed-effects linear models and linear regression models were applied to investigate the relationship between different World Health Organization obesity classifications and surgical outcome. RESULTS: A total of 88 patients had surgery for degenerative cervical spine disease, with 97.72% follow-up at 3 months and 94.31% at 6 months postoperatively. Mean BMI was 27.92 ± 7.9 kg/m(2); 28.57% were overweight (BMI 25-29.9), and 31.57% were obese (Class I obesity, BMI 30-34.9). We found a positive correlation between BMI and VAS at 6 months (R = 0.298, P < 0.05) and between BMI and change in Neck Disability Index (R = 0.385, P < 0.01), suggesting that obese patients had less improvement and more pain 6 months postoperatively than nonobese patients. Overweight patients had worse MCS values (R = -0.275, P < 0.05) and obese patients had worse visual analog scale values 6 months after surgery (R = 0.284, P < 0.03). Interestingly, surgeon ratings matched the aforementioned results. Patients with greater BMI had worse surgeon ratings 3 and 6 months postoperatively (R = 0.555, P < 0.05), whereas normal-weight patients had better outcomes when rated from the surgeon's perspective (R = -0.536, P < 0.05). CONCLUSION: Obese patients had worse postoperative patient-reported outcome scores and less overall patient-rated improvement compared with nonobese patients. Patients with BMI >25 reported less improvement after surgery both in the patients' and in the surgeons' perspectives.

Multifunctional nanoparticles for brain tumor imaging and therapy.

Brain tumors are a diverse group of neoplasms that often carry a poor prognosis for patients. Despite tremendous efforts to develop diagnostic tools and therapeutic avenues, the treatment of brain tumors remains a formidable challenge in the field of neuro-oncology. Physiological barriers including the blood-brain barrier result in insufficient accumulation of therapeutic agents at the site of a tumor, preventing adequate destruction of malignant cells. Furthermore, there is a need for improvements in brain tumor imaging to allow for better characterization and delineation of tumors, visualization of malignant tissue during surgery, and tracking of response to chemotherapy and radiotherapy. Multifunctional nanoparticles offer the potential to improve upon many of these issues and may lead to breakthroughs in brain tumor management. In this review, we discuss the diagnostic and therapeutic applications of nanoparticles for brain tumors with an emphasis on innovative approaches in tumor targeting, tumor imaging, and therapeutic agent delivery. Clinically feasible nanoparticle administration strategies for brain tumor patients are also examined. Furthermore, we address the barriers towards clinical implementation of multifunctional nanoparticles in the context of brain tumor management.