Developing Mixed-Effects Models to Compare the Predictive Ability of Various Comorbidity Indices in a Contemporary Cohort of Patients Undergoing Lumbar Fusion

BACKGROUND AND OBJECTIVE

As incidence of operative spinal pathology continues to grow, so do the rates of lumbar spinal fusion procedures. Comorbidity indices can be used preoperatively to predict potential complications. However, there is a paucity of research defining the optimal comorbidity indices in patients undergoing spinal fusion surgery. We aimed to use modeling strategies to evaluate the predictive validity of various comorbidity indices and combinations thereof.

METHODS

Patients who underwent spinal fusion were queried using data from the Nationwide Readmissions Database for the years 2016 through 2019. Using comorbidity indices as predictor variables, receiver operating characteristic curves were developed for pertinent complications such as mortality, nonroutine discharge, top-quartile cost, top-quartile length of stay, and 30-day readmission.

RESULTS

A total of 750 183 patients were included. Nonroutine discharges occurred in 161 077 (21.5%) patients. The adjusted all-payer cost for the procedure was $37 616.97 ± $27 408.86 (top quartile: $45 409.20), and the length of stay was 4.1 ± 4.4 days (top quartile: 8.1 days). By comparing receiver operating characteristics of various models, it was found that models using Frailty + Elixhauser Comorbidity Index (ECI) as the primary predictor performed better than other models with statistically significant P -values on post hoc testing. However, for prediction of mortality, the model using Frailty + ECI was not better than the model using ECI alone ( P = .23), and for prediction of all-payer cost, the ECI model outperformed the models using frailty alone ( P < .0001) and the model using Frailty + ECI ( P < .0001).

CONCLUSION

This investigation is the first to use big data and modeling strategies to delineate the relative predictive utility of the ECI and Johns Hopkins Adjusted Clinical Groups comorbidity indices for the prognostication of patients undergoing lumbar fusion surgery. With the knowledge gained from our models, spine surgeons, payers, and hospitals may be able to identify vulnerable patients more effectively within their practice who may require a higher degree of resource utilization.

Staged Resection of Difficult-to-Treat Intracranial Meningiomas: A Systematic Review of the Indications, Surgical Approaches, and Postoperative Outcomes

Introduction  Meningiomas-the most common extra-axial tumors-are benign, slow-growing dural-based lesions that can involve multiple cranial fossae and can progress insidiously for years until coming to clinical attention secondary to compression of adjacent neurovascular structures. For complex, multicompartmental lesions, multistaged surgeries have been increasingly shown to enhance maximal safe resection while minimizing adverse sequela. Here, we systematically review the extant literature to highlight the merits of staged resection. Methods  PubMed, Scopus, and Web of Science databases were queried to identify articles reporting resections of intracranial meningiomas using a multistaged approach, and articles were screened for possible inclusion in a systematic process performed by two authors. Results  Of 118 identified studies, 36 describing 169 patients (mean age 42.6 ± 21.3 years) met inclusion/exclusion criteria. Petroclival lesions comprised 57% of cases, with the most common indications for a multistaged approach being large size, close approximation of critical neurovascular structures, minimization of brain retraction, identification and ligation of deep vessels feeding the tumor, and resection of residual tumor found on postoperative imaging. Most second-stage surgeries occurred within 3 months of the index surgery. Few complications were reported and multistaged resections appeared to be well tolerated overall. Conclusions  Current literature suggests multistaged approaches for meningioma resection are well-tolerated. However, there is insufficient comparative evidence to draw definitive conclusions about its advantages over an unstaged approach. There are similarly insufficient data to generate an evidence-based decision-making framework for when a staged approach should be employed. This highlights the need for collaborative efforts among skull base surgeons to establish an evidentiary to support the use of staged approaches and to outline those indications that merit such an approach.

Robot-assisted percutaneous pedicle screw placement accuracy compared with alternative guidance in lateral single-position surgery: a systematic review and meta-analysis

OBJECTIVE

While single-position surgery (SPS) eliminates the need for patient repositioning, the placement of screws in the unconventional lateral position poses unique challenges related to asymmetry relative to the surgical table. Use of robotic guidance or intraoperative navigation can help to overcome this. The aim of this study was to compare the relative accuracies offered by these various navigation modalities for pedicle screws placed in lateral SPS.

METHODS

According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the PubMed/Medline, Embase, and Cochrane Library databases were queried for studies reporting pedicle screw placement accuracy using fluoroscopic, CT-navigated, O-arm, or robotic guidance in lateral SPS, and a systematic review and meta-analysis was performed. Included studies all compared evaluated screw placement accuracy in lateral SPS using a single navigation method. Quality assessment was performed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system; risk of bias was assessed using the Newcastle-Ottawa Scale and the Joanna Briggs Institute checklist. The primary outcome, rate of pedicle screw breach, was analyzed using random-effects meta-analysis.

RESULTS

Eleven studies were included comprising 548 patients who underwent the placement of instrumentation with 2488 screws. For the fluoroscopic, CT-navigated, O-arm, and robotic guidance cohorts, there were 3, 2, 3, and 3 studies, respectively. Breach rates by modality were as follows: fluoroscopic guidance (6.6%), CT navigation (4.7%), O-arm (3.9%), and robotic guidance (3.9%). Random-effects meta-analysis showed a significant difference between studies, with an overall breach rate of 4.9% (95% CI 3.1%-7.5%; p < 0.001); however, testing for subgroup differences failed to show a significant difference between guidance modalities (QM = 0.69, df = 3; p = 0.88). Heterogeneity between studies was significant (I2 = 79.0%, τ2 = 0.41, χ2 = 47.65, df = 10; p < 0.001).

CONCLUSIONS

Robotic guidance of screws is noninferior to alternative guidance modalities in lateral SPS; however, additional prospective studies directly comparing different guidance types are merited.

Developing Predictive Models to Anticipate Shunt Complications in 33,248 Pediatric Patients with Shunted Hydrocephalus Utilizing Machine Learning

INTRODUCTION

Hydrocephalus is a common pediatric neurosurgical pathology, typically treated with a ventricular shunt, yet approximately 30% of patients experience shunt failure within the first year after surgery. As a result, the objective of the present study was to validate a predictive model of pediatric shunt complications with data retrieved from the Healthcare Cost and Utilization Project (HCUP) National Readmissions Database (NRD).

METHODS

The HCUP NRD was queried from 2016 to 2017 for pediatric patients undergoing shunt placement using ICD-10 codes. Comorbidities present upon initial admission resulting in shunt placement, Johns Hopkins Adjusted Clinical Groups (JHACG) frailty-defining criteria, and Major Diagnostic Category (MDC) at admission classifications were obtained. The database was divided into training (n = 19,948), validation (n = 6,650), and testing (n = 6,650) datasets. Multivariable analysis was performed to identify significant predictors of shunt complications which were used to develop logistic regression models. Post hoc receiver operating characteristic (ROC) curves were created.

RESULTS

A total of 33,248 pediatric patients aged 6.9 ± 5.7 years were included. Number of diagnoses during primary admission (OR: 1.05, 95% CI: 1.04-1.07) and initial neurological admission diagnoses (OR: 3.83, 95% CI: 3.33-4.42) positively correlated with shunt complications. Female sex (OR: 0.87, 95% CI: 0.76-0.99) and elective admissions (OR: 0.62, 95% CI: 0.53-0.72) negatively correlated with shunt complications. ROC curve for the regression model utilizing all significant predictors of readmission demonstrated area under the curve of 0.733, suggesting these factors are possible predictors of shunt complications in pediatric hydrocephalus.

CONCLUSION

Efficacious and safe treatment of pediatric hydrocephalus is of paramount importance. Our machine learning algorithm delineated possible variables predictive of shunt complications with good predictive value.

Three-Dimensional-Printed Titanium Versus Polyetheretherketone Cages for Lumbar Interbody Fusion: A Systematic Review of Comparative In Vitro, Animal, and Human Studies

Interbody fusion is a workhorse technique in lumbar spine surgery that facilities indirect decompression, sagittal plane realignment, and successful bony fusion. The 2 most commonly employed cage materials are titanium (Ti) alloy and polyetheretherketone (PEEK). While Ti alloy implants have superior osteoinductive properties they more poorly match the biomechanical properties of cancellous bones. Newly developed 3-dimensional (3D)-printed porous titanium (3D-pTi) address this disadvantage and are proposed as a new standard for lumbar interbody fusion (LIF) devices. In the present study, the literature directly comparing 3D-pTi and PEEK interbody devices is systematically reviewed with a focus on fusion outcomes and subsidence rates reported in the in vitro, animal, and human literature. A systematic review directly comparing outcomes of PEEK and 3D-pTi interbody spinal cages was performed. PubMed, Embase, and Cochrane Library databases were searched according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. Mean Newcastle-Ottawa Scale score for cohort studies was 6.4. A total of 7 eligible studies were included, comprising a combination of clinical series, ovine animal data, and in vitro biomechanical studies. There was a total population of 299 human and 59 ovine subjects, with 134 human (44.8%) and 38 (64.4%) ovine models implanted with 3D-pTi cages. Of the 7 studies, 6 reported overall outcomes in favor of 3D-pTi compared to PEEK, including subsidence and osseointegration, while 1 study reported neutral outcomes for device related revision and reoperation rate. Though limited data are available, the current literature supports 3D-pTi interbodies as offering superior fusion outcomes relative to PEEK interbodies for LIF without increasing subsidence or reoperation risk. Histologic evidence suggests 3D-Ti to have superior osteoinductive properties that may underlie these superior outcomes, but additional clinical investigation is merited.

Acute Mania and Psychosis in the Context of Primary Adrenal Insufficiency: A Systematic Review of the Literature

BACKGROUND

Given the sparse nature of acute mania or psychosis in primary adrenal insufficiency (PAI), physicians may not be aware of the association of these two entities.

OBJECTIVE

To conduct a systematic review of the literature for the purpose of identifying all studies reporting mania and/or psychosis in individuals with PAI.

METHOD

We conducted a systematic review according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using the PubMed, Embase, and Web of Science databases from June 22, 1970 to June 22, 2021, for the purpose of identifying all studies reporting instances of mania or psychosis associated with PAI.

RESULTS

We identified nine case reports featuring nine patients (M age = 43.3 years, male = 44.4%) over eight countries that fit our inclusion/exclusion criteria. Eight (89%) of the patients had experienced psychosis. Manic and/or psychotic symptom resolution was achieved in 100% of the cases, of which steroid replacement therapy was efficacious in seven (78%) cases and was sufficient in six (67%).

CONCLUSION

Acute mania and psychosis in the context of PAI is a very rare presentation of an already uncommon disease. Resolution of acute psychiatric change is reliably achieved with the correction of underlying adrenal insufficiency.

Staged Open Cranial Surgery for Primary Intra-axial Neoplasms: A Systematic Review

BACKGROUND

Staged surgery for skull base lesions has been utilized to facilitate maximal safe resection and optimize outcomes while minimizing morbidity and complications. Conversely, staged surgery for primary intraparenchymal neoplasms is less commonly performed and has not been reported as extensively within the literature. As such, we performed a systematic review to examine the unique surgical indications for staging, timing between stages, specific surgical approaches employed, and postoperative complications of staged surgery for primary intra-axial neoplasms.

METHODS

A literature search was conducted in August 2021 using PubMed, Web of Science, and Cochrane databases using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) recommendations. Titles and abstracts were evaluated independently by two authors, after which articles were selected for final analysis based on application of strict inclusion criteria during full text screen. Each included article was then qualitatively assessed and relevant variables - including operative approaches, timing, and outcomes - were extracted for synthesis.

RESULTS

Of 115 results, 7 articles were included for final analysis and consisted of 17 pediatric and 4 adult patients. Staged approaches were more commonly utilized in the pediatric patient population for resection of astrocytoma and glioma. Pediatric patients had a timing of surgeries ranging from 5-10 days between operations, compared to 18 days-4 months in adult patients. Complications in pediatric patients were most commonly hemiparesis, hydrocephalus, CN VI and VII palsies, truncal ataxia, and cerebellar mutism, while complications in adult patients included language and abstract thinking deficits, respiratory failure, and motor weakness.

CONCLUSION

This study reports the first comprehensive review of staged surgical procedures for primary, intra-axial cranial neoplasms. There exists a large degree of heterogeneity in complications resulting from staged surgeries for intra-axial neoplasms, which are similar to complications associated with single-stage surgery for intraparenchymal lesions as well as multi-stage surgeries for skull base lesions.

A Retrospective Cohort Study of Implantable Pulse Generator Surgical Site Infections After Deep Brain Stimulation Surgery With an Antibacterial Envelope

INTRODUCTION

Deep brain stimulation (DBS) surgery is an established treatment for many patients with neurologic disease, and a common complication of DBS is surgical site infection (SSI). In 2016, neurosurgeons at our institution began enclosing implantable pulse generators (IPGs) within fully absorbable, antibacterial envelopes in patients who underwent initial DBS implantation. We sought to determine whether the use of antibacterial envelopes reduced IPG-related SSIs.

MATERIALS AND METHODS

We performed a retrospective chart review of all adult patients who underwent initial DBS implantation at Stanford Hospital between November 14, 2012, and November 9, 2020. Operative details, perioperative antibiotics, comorbidities, and postoperative complications were extracted for all patients. Univariate and multivariate logistic regression were used to identify factors associated with SSIs within three months of surgery, and interrupted time-series analysis was performed to assess whether the departmental adoption of the antibacterial envelope led to a reduction in IPG SSIs.

RESULTS

Of 344 patients who underwent initial IPG implantation with the antibacterial envelope, one developed an SSI within three months of surgery (0.3%), compared with six of 204 patients (2.9%) who underwent the same procedure without the antibacterial envelope (odds ratio: 0.10, 95% CI: 0.01-0.80, p = 0.031). Univariate logistic regression revealed that the antibacterial envelope and 2000-mg intravenous cefazolin perioperatively were associated with reduced SSI risk, whereas no other factors reached statistical significance. After adjusting for comorbidities, no association remained statistically significant. Interrupted time-series analysis showed a reduction in SSIs after 2016, but the effect was not significant.

CONCLUSIONS

The adoption of antibacterial envelopes was found to reduce IPG SSIs at the univariate level, but this association did not remain significant after controlling for confounding variables including perioperative antibiotic administration. Although encouraging, this study does not conclusively establish that the use of antibacterial pouches in patients who underwent initial DBS implantation reduces the incidence of IPG SSIs. Future prospective studies that control for confounding variables are necessary to determine the efficacy of antibacterial envelopes in reducing post-DBS infections at the IPG site before clear recommendations can be made.

The Use of Psychedelics in the Treatment of Medical Conditions: An Analysis of Currently Registered Psychedelics Studies in the American Drug Trial Registry

Although early therapeutic research on psychedelics dates back to the 1940s, this field of investigation was met with many cultural and legal challenges in the 1970s. Over the past two decades, clinical trials using psychedelics have resumed. Therefore, the goal of this study was to (1) better characterize the recent uptrend in psychedelics in clinical trials and (2) identify areas where potentially new clinical trials could be initiated to help in the treatment of widely prevalent medical disorders. A systematic search was conducted on the clinicaltrials.gov database for all registered clinical trials examining the use of psychedelic drugs and was both qualitatively and quantitatively assessed. Analysis of recent studies registered in clinicaltrials.gov was performed using Pearson’s correlation coefficient testing. Statistical analysis and visualization were performed using R software. In totality, 105 clinical trials met this study’s inclusion criteria. The recent uptrend in registered clinical trials studying psychedelics (p = 0.002) was similar to the uptrend in total registered clinical trials in the registry (p < 0.001). All trials took place from 2007 to 2020, with 77.1% of studies starting in 2017 or later. A majority of clinical trials were in phase 1 (53.3%) or phase 2 (25.7%). Common disorders treated include substance addiction, post-traumatic stress disorder, and major depressive disorder. Potential research gaps include studying psychedelics as a potential option for symptomatic treatment during opioid tapering. There appears to be a recent uptrend in registered clinical trials studying psychedelics, which is similar to the recent increase in overall trials registered. Potentially, more studies could be performed to evaluate the potential of psychedelics for symptomatic treatment during opioid tapering and depression refractory to selective serotonin reuptake inhibitors.

Novel use of nonpenetrating titanium clips for pediatric primary spinal dural closure: A technical note

BACKGROUND

Dural closure is an important part of any pediatric spinal procedure with intradural pathology to prevent post-operative cerebrospinal fluid (CSF) egress and associated complications. Utilization of nonpenetrating titanium clips is one closure option that may have technical advantages such as ease of use and amenability to a narrow surgical corridor. No data exist on the efficacy of these clips for pediatric spinal dural closure.

METHODS

A single surgeon case series of 152 pediatric patients underwent procedures involving lumbar durotomy with subsequent dural closure using the AnastoClip® nonpenetrating titanium clip closure system. Rates of infection and cerebrospinal fluid leak were measured during the follow-up period.

RESULTS

A total of 152 pediatric patients (mean age: 6.25 ± 5.85 years, 50.7 % female) underwent intradural surgery with clip closure. The mean follow-up time was 57.0 ± 28.5 months. All patients were initially indicated for procedures involving spinal durotomy, with a majority being isolated tethered cord release (84.2 %). Others required tethered cord release and excision of a lipomyelomeningocele, spinal meningioma or arachnoid cyst (15.8 %). Post operative CSF leak occurred in two (1.32 %) patients at 11 and 18 days. Only one (0.66 %) patient was diagnosed with an infection, which was in a separate patient from those that had CSF leaks.

CONCLUSION

The remarkably low incidence of post-operative CSF leak and infection with nonpenetrating titanium clips suggests a strong safety and efficacy profile for this form of dural closure in a pediatric cohort. Further research evaluating this technique is required to fully demonstrate its acceptability as a cost-effective alternative to traditional suture-based closure.

Demographic Predictors of Treatment and Complications for Adult Spinal Deformity: An Analysis of the National Inpatient Sample

PURPOSE

To examine the role of demographics on surgical management and inpatient complications in patients with spinal deformity between 2010 and 2014 via retrospective analysis.

METHODS

Data were obtained from the National Inpatient Sample (NIS). International Classification of Diseases 9th revision codes were used to identify patients with a primary diagnosis of adult spinal deformity (ASD). Multivariable Poisson regression analyses were used to determine whether any individual demographic variables were predictive of surgical management, surgical complexity, postoperative complications and revision operations.

RESULTS

17,433 patients were identified for analysis. Surgical intervention was performed for 94.5% of patients with a primary diagnosis of ASD. Patients at urban teaching hospitals were the most likely to receive surgery (OR= 2.13; 95% CI 1.51-2.95; p < 0.001) relative to rural patients. Female patients were the majority undergoing surgery and were more likely to receive a complication or require a revision when controlling for surgical complexity. Medicare patients were the least likely to undergo surgery and the most likely to receive complex fusion when undergoing an operation. Medicare patients were the least likely to experience complications (OR=0.89; 95% CI 0.80-0.98; p = 0.022) after adjusting for surgical complexity. With regards to race and ethnicity, Hispanics had a decreased likelihood of receiving a revision surgery.

CONCLUSION

There were substantial differences in rates of surgical management, postoperative complications, and revisions among individuals of different demographics including sex, insurance status, ethnicity and hospital teaching status. Further research evaluating the effect of demographics in spine surgery is warranted to fully understand their influence on patient outcomes.

Evaluating the incidence and predictors of anti-NMDAR encephalitis in a contemporary cohort of patients diagnosed with dermoid tumors: A national inpatient sample analysis

INTRODUCTION

Anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis is a form of encephalitis previously associated with dermoid tumors. However, most studies in the literature evaluating the disease are case reports and small patient cohorts, limiting robust statistical analysis. Here, we demonstrate predictors of anti-NMDAR encephalitis in a large cohort of US patients.

METHODS

We used the 2016 National Inpatient Sample (NIS) to identify a cohort of 24,270 admitted for an ovarian dermoid tumor. Of these patients, 50 (0.21%) were diagnosed with anti-NMDAR encephalitis. Patient demographics, hospital characteristics, length of stay (LOS), and complications were collected. Statistical analysis consisted of odds ratios with chi-square testing to compare categorical variables.

RESULTS

The mean age of all patients with dermoid tumors was 45.5 ± 18.0 years, and the mean age of patients with diagnosed anti-NMDAR encephalitis was 27.4 ± 4.9 years. The mean LOS in the dermoid tumor cohort was 3.5 ± 4.9 days, while the mean LOS in the anti-NMDAR encephalitis cohort was 31.9 ± 25.9 days (p < 0.001). The mean cost in the dermoid tumor cohort was $44,813.18±$54,305.90, while the mean cost in the anti-NMDAR encephalitis cohort was $445,628.60±$665,423.40 (p < 0.001). Patients with age above 30 years with dermoid tumors had significantly lower odds of developing anti-NMDAR encephalitis compared to patients younger than 30 years (OR: 0.19; 95%CI: 0.045-0.67; p-value: 0.003). White patients had significantly lower odds of developing anti-NMDAR encephalitis (OR: 0.19; 95%CI: 0.026-0.77; p-value: 0.013), and Black patients had significantly higher odds of developing anti-NMDAR encephalitis (OR: 3.45; 95%CI: 1.00-12.46; p-value: 0.044).

CONCLUSION

Patient predictors of developing anti-NMDAR encephalitis include age, race, ethnicity and patients who go on to develop anti-NMDAR encephalitis have a significantly increased hospital LOS and cost compared to those who do not. Future research, including multi-center clinical trials and longitudinal data, is necessary to fully cement the findings of this manuscript.

Supraorbital Keyhole Craniotomy in Pediatric Neurosurgery: A Systematic Review of Clinical Outcomes and Cosmetic Outcomes

BACKGROUND

Supraorbital keyhole craniotomy is a minimally invasive approach used to access the parasellar region with advantages of decreased cortical exposure, simple closure, and decreased risk of postoperative cerebrospinal fluid leak. The incision of this approach, however, has raised cosmetic concerns, especially for pediatric patients. The aim of this study is to assess postoperative complications and cosmeses of the supraorbital keyhole approach for resection of intracranial lesions in pediatric patients.

METHODS

A literature search of PubMed, Scopus, and Web of Science databases was performed on June 1, 2021, searching for all studies of pediatric patients undergoing supraorbital keyhole craniotomy for surgical resection of lesions in the anterior fossa/sellar region.

RESULTS

Of 729 unique hits, 15 supraorbital keyhole studies reporting on 177 pediatric cases were included in the final review. Quality of all included studies was moderate. Overall, the surgery was well tolerated with a low number of severe adverse events. A wide variety of pathologies were treated with this approach. Complications of surgery included changes in vision, epidural hematoma, subdural hematoma, cerebrospinal fluid leak, and wound infection. At 6 weeks of follow-up, surgical scars in most patients were noted to be minimally detectable. At 3-6 months of follow-up, scars were no longer visible. Cosmetic complications included 5 bone defects, 1 split eyebrow, and 1 case of ptosis.

CONCLUSIONS

This study suggests that supraorbital keyhole craniotomy is a safe and effective approach to access the parasellar region in pediatric patients with excellent cosmetic outcomes reported across multiple institutions.

Demographic Predictors of Treatment and Complications for Spinal Disorders: Part 2, Lumbar Spine Trauma

Objective

To study the impact of demographic factors on management of traumatic injury to the lumbar spine and postoperative complication rates.

Methods

Data was obtained from the National Inpatient Sample (NIS) between 2010–2014. International Classification of Diseases, 9th revision, Clinical Modification codes identified patients diagnosed with lumbar fractures or dislocations due to trauma. A series of multivariate regression models determined whether demographic variables predicted rates of complication and revision surgery.

Results

A total of 38,249 patients were identified. Female patients were less likely to receive surgery and to receive a fusion when undergoing surgery, had higher complication rates, and more likely to undergo revision surgery. Medicare and Medicaid patients were less likely to receive surgical management for lumbar spine trauma and less likely to receive a fusion when operated on. Additionally, we found significant differences in surgical management and postoperative complication rates based on race, insurance type, hospital teaching status, and geography.

Conclusion

Substantial differences in the surgical management of traumatic injury to the lumbar spine, including postoperative complications, among individuals of demographic factors such as age, sex, race, primary insurance, hospital teaching status, and geographic region suggest the need for further studies to understand how patient demographics influence management and complications for traumatic injury to the lumbar spine.

Does neoadjuvant chemotherapy diminish the sex disparity in bladder cancer survival after radical cystectomy?

INTRODUCTION

Sex-specific survival disparities for bladder cancer outcomes after radical cystectomy (RC) have been demonstrated in several studies. However, these studies predate the widespread adoption of neoadjuvant chemotherapy (NAC). We evaluated the differences in sex-specific survival between patients who received NAC with those who did not, using a contemporary national outcomes database.

METHODS

The National Cancer Data Base was queried from 2004 to 2015 to identify subjects who underwent RC. Kaplan-Meier method with log-rank test was performed to compare all-cause mortality between men and women at each pathologic (p) TNM stage group: T1-4N0, N+ and M+ disease. Associations for all-cause mortality were identified using an adjusted Cox regression analysis, and our findings were confirmed with a subgroup analysis.

RESULTS

A total of 9,835 subjects (7,483 men and 2,532 women) were included in the analysis. Kaplan-Meier survival curves and Cox regression analysis demonstrated female sex was not associated with worse overall survival compared to males (HR 0.947, 95%CI 0.852-1.053, P = 0.947) in the overall cohort. Stratified by pT stage and node positivity, worse overall survival was seen in women with pT4 disease who did not receive NAC compared to men (5-year OS 9.6% women vs. 15.2% men, P < 0.001), but no sex-specific difference was seen across all groups in patients who received NAC. Subgroup multivariable analysis showed that female sex conferred a survival disadvantage for pT4 (HR 1.369, P = 0.026) disease only in patients who did not receive NAC.

CONCLUSIONS

In a contemporary cohort of subjects who underwent RC, administration of NAC narrows the sex survival-gap in advanced stage bladder cancer. Strategies to improve NAC usage in women should be adopted to overcome potential sex-specific differences such as delayed diagnosis, anatomic differences in higher stage disease, or altered tumor biology which may contribute to differences in oncologic outcomes.

Characterizing Adverse Events of Cranioplasty Implants After Craniectomy: A Retrospective Review of the Federal Manufacturer and User Facility Device Experience Database

Introduction

Cranioplasty is performed by placing an artificial plate in place of a patient's native skull bones to repair post-craniectomy defects after trauma. Implanted materials can range from titanium to synthetic polyether derivatives and are produced by multiple manufacturers. There are few studies characterizing complications associated with these cranioplasty plates to date. We aimed to quantify and categorize complications of these devices using a national federal database.

Methods

The Manufacturer and User Facility Device Experience (MAUDE) database was queried for all entries reported under the category "plate, cranioplasty, preformed, non-alterable" with the additional product code GXN between the time range from September 1, 2010, to September 1, 2020. After data extraction, each of the entries was screened for duplicates and tabulated into different categories of complications. Additionally, product information such as the plate manufacturer was extracted from each entry.

Results

The search yielded 329 unique event reports. The most frequent complications were infection (39%), followed by incorrectly fitting implants (30%) and implant breaks (6%). Other major complications included cerebrospinal fluid leakage and cerebral edema (5%), wound dehiscence (5%), and migration of hardware (3%). The brands associated with the most entries in the database were the Synthes (DePuy Synthes Companies, Massachusetts, United States) polyetheretherketone (PEEK) patient-specific implants (PSI) (57%), the Biomet (Zimmer Biome, Indiana, United States) hard tissue replacement-polyetherketoneketone (HTR-PEKK) patient-matched implant (PMI) (23%), and the AccuShape PEEK PSI (MedCAD, Dallas, USA) (5%).

Conclusions

Infection and improperly fitting implants appear to be the two most frequent complications of cranioplasty plates. The goals of future research should include the prevention of plate infections as well as improving techniques to custom-fit implantable devices.

Feasibility of in-office MRI-targeted partial gland cryoablation for prostate cancer: an IDEAL stage 2A study

Objectives

Cryoablation for prostate cancer is typically performed under general anaesthesia. We explore the safety, feasibility and costs of in-office MRI-targeted prostate partial gland cryoablation (PGC) under local anaesthesia. We hypothesise that an office-based procedure under local anaesthesia may yield greater patient convenience and lower health costs with similar outcomes to a general anaesthesia approach.

Design/participants/setting/interventions

Retrospective study of men diagnosed with clinically significant prostate cancer (grade group (GG) ≥2) who elected to undergo in-office PGC under local anaesthesia.

Main outcome measures

A total of 55 men with GG ≥2 prostate cancer underwent PGC under local anaesthesia, and 35 of 43 men (81.4%) who attained ≥6 months of follow-up post-treatment underwent MRI-targeted surveillance biopsy. We used MRI findings and targeted biopsy to characterise post-PGC oncological outcomes. Complications were categorised using Common Terminology Criteria for Adverse Events (CTCAE). Expanded Prostate Cancer Index-Clinical Practice was used to characterise urinary and sexual function scores at baseline, 4 and 9 months post-PGC. Time-driven activity-based costing was used to determine healthcare costs of in-office PGC.

Results

Five (9.1%) men experienced CTCAE score 3 adverse events. Urinary and sexual function did not change significantly from baseline to 4 months (p=0.20 and p=0.08, respectively) and 9 months (p=0.23 and p=0.67, respectively). Twenty-two men (62.9%) had no cancer or GG1 and 13 (37.1%) men had GG≥2 on post-PGC biopsy. Moreover, the median cost of in-office PGC was US$4,463.05 (range US$4,087.19–US7,238.16) with disposables comprising 69% of the cost.

Conclusions

In-office PGC is feasible under local anaesthesia with favourable functional outcome preservation and adverse events profile at significantly lower costs compared with a general anaesthesia approach.

Surgical Outcomes After Single-Level Endoscopic Transforaminal Lumbar Interbody Fusion: A Systematic Review and Meta-Analysis

Background and objective

Novel surgical advancements have introduced endoscopic operative techniques for low back surgery, including transforaminal lumbar interbody fusion (TLIF), which theoretically allows for improved decompression with minimal invasiveness. In addition, endoscopically performed TLIF has allowed for the use of local anesthesia as an alternative method to general anesthesia for patients. We aimed to evaluate the clinical outcomes in patients undergoing endoscopic TLIF and also compare the outcomes in patients undergoing general versus local anesthesia.

Methods

The databases of PubMed, Medline, Embase, and the Cochrane Library were queried for all studies involving patients undergoing endoscopic TLIF. After the extraction of the data and assessment of study quality via the Newcastle-Ottawa Scale, statistical analysis was performed with the R software (The R Foundation, Vienna, Austria) metafor package. The random-effects model was used as the data was largely heterogeneous (I² >50%).

Results

In total, 15 studies involving a total of 441 patients were selected for the final quantitative meta-analysis. The overall mean difference between the postoperative visual analog scale (VAS) leg scores and preoperative VAS scores was 3.45 (95% CI: 4.93-1.97, p: <0.01). Postoperative VAS low back scores revealed a mean difference of 3.36 (95% CI: 5.09-1.63, p: <0.01). The overall mean difference of ODI scores was 4.58 (95% CI: 6.76-2.40, p: <0.01). Mean blood loss was 136.32 mL and the mean operative time was 149.15 minutes. The mean length of stay postoperatively was lower in the local anesthesia group compared to the general anesthesia group (1.40 vs 5.99 days respectively). There were no outcome variables of patients undergoing general anesthesia versus local anesthesia that showed statistically significant differences in this analysis due to the small amount of data published on patients undergoing endoscopic TLIF with local anesthesia. In addition, the failure of studies in reporting standard deviations as data parameters further limited the quantitative analysis.

Conclusion

Endoscopic TLIF appears to be a viable option for patients undergoing lumbar interbody fusion. Initial data reveal that endoscopic TLIF with local anesthesia may offer patients outcomes similar to those in patients undergoing endoscopic TLIF with general anesthesia, with lower operative times and length of stay.

A mobile vision testing application based on dynamic distance determination from the human corneal limbus

Here we present a mobile application that accurately determines the distance between an optical sensor and the human corneal limbus for visual acuity assessment. The application uses digital image processing and randomized circle detection to locate the cornea. Then, a reference scaling measurement is employed to calculate distance from the sensor to a user. To determine accuracy and generalizability, testing was conducted both with 200 static images, 25 images each of males and females for four ethnic groups from a facial image database, and live image streams from a test subject. Average absolute corneal radius error over 10 trials for the static images was 6.36%, while average absolute distance error for the live image streams was less than 1%. Subsequently, distance measurements were used to scale letter sizes for a Snellen Chart-based visual acuity assessment. This system enables monitoring of chronic retinal diseases, as patients can quickly and accurately measure their visual acuity through the mobile eye exam suite.

Definitive and sustained increase in prostate cancer metastases in the United States

INTRODUCTION

We examined the most recent Surveillance, Epidemiology, and End Results release to corroborate temporal trends in nonmetastatic and distant prostate cancer metastases in the United States.

METHODS

Surveillance, Epidemiology, and End Results was analyzed for the incidence of nonmetastatic and distant metastasis for men with prostate cancer aged 50-74 and ≥75 years during 2004-2015. Incidence ratios (IR) were calculated relative to the year prior.

RESULTS

The incidence of distant metastasis significantly increased from 451.0 to 504.0 per million (IR:1.12, 95% CI:1.01-1.24) from 2011 to 2012 and 532.3 to 586.1 per million (IR:1.10, 95% CI:1.00-1.21) from 2014 to 2015 in men aged ≥75 years. The incidence of distant metastasis did not significantly increase in men aged 55-74 over the study period.

CONCLUSION

We demonstrate a sustained and definitive increase in prostate cancer distant metastases in men aged ≥75 years. Although our observational study design cannot pinpoint the exact cause of this increase, which is likely multifactorial, this shift reverses declines in metastases at diagnoses that followed the advent of prostate-specific antigen screening.

Concurrent Inguinal Hernia Repair in Patients Undergoing Minimally Invasive Radical Prostatectomy: A National Surgical Quality Improvement Program Study

OBJECTIVE

To compare perioperative 30-day outcomes between minimally invasive radical prostatectomy (MIRP) with and without concurrent inguinal hernia repair (IHR) using a national database.

METHODS

The National Surgical Quality Improvement Program database was queried for MIRP from 2012 to 2015. Concurrent IHR was identified using relevant Current Procedural Terminology codes. Primary outcomes were overall complications, reoperations, unplanned readmissions, and mortality within 30 days of MIRP. Secondary outcomes included operative time (OT), length of stay (LOS), prolonged length of stay (PLOS, >2 days), and discharged to continued care (DCC). Multivariable logistic regression was performed to identify the association between concurrent IHR and outcomes.

RESULTS

A total of 18,065 patients were included; 375 (2.1%) had concurrent IHR. The unadjusted comparison showed no significant difference in overall complication, reoperation, unplanned readmission, or mortality rates between MIRP+IHR and MIRP only groups. OT was longer in the MIRP+IHR group (229 vs 195 minutes, p < 0.001) but no differences were found in LOS, PLOS, or DCC rates. Multivariable logistic regression showed concurrent IHR was not associated with increased odds of overall complication (odds ratio [OR] = 0.83, 95% confidence interval [CI] = 0.49-1.40, p = 0.479), reoperation (OR = 0.57, 95% CI = 0.14-2.30, p = 0.426), unplanned readmission (OR = 0.92, 95% CI = 0.51-1.64, p = 0.771), PLOS (OR = 1.19, 95% CI = 0.86-1.63, p = 0.297), or DCC (OR = 1.94, 95% CI = 0.70-5.34, p = 0.202).

CONCLUSIONS

Concurrent IHR with MIRP was associated with longer OT, but there were no increased 30-day adverse outcomes within the National Surgical Quality Improvement Program (NSQIP) database. These data support the safety of performing concurrent IHR at the time of MIRP and it should be considered to spare men an additional procedure.

IRC +10 216 in 3-D: morphology of a TP-AGB star envelope

During their late pulsating phase, AGB stars expel most of their mass in the form of massive dusty envelopes, an event that largely controls the composition of interstellar matter. The envelopes, however, are distant and opaque to visible and NIR radiation: their structure remains poorly known and the mass-loss process poorly understood. Millimeter-wave interferometry, which combines the advantages of longer wavelength, high angular resolution and very high spectral resolution is the optimal investigative tool for this purpose. Mm waves pass through dust with almost no attenuation. Their spectrum is rich in molecular lines and hosts the fundamental lines of the ubiquitous CO molecule, allowing a tomographic reconstruction of the envelope structure. The circumstellar envelope IRC +10 216 and its central star, the C-rich TP-AGB star closest to the Sun, are the best objects for such an investigation. Two years ago, we reported the first detailed study of the CO(2-1) line emission in that envelope, made with the IRAM 30-m telescope. It revealed a series of dense gas shells, expanding at a uniform radial velocity. The limited resolution of the telescope (HPBW 11″) did not allow us to resolve the shell structure. We now report much higher angular resolution observations of CO(2-1), CO(1-0), CN(2-1) and C4H(24-23) made with the SMA, PdB and ALMA interferometers (with synthesized half-power beamwidths of 3″, 1″ and 0.3″, respectively). Although the envelope appears much more intricate at high resolution than with an 11″ beam, its prevailing structure remains a pattern of thin, nearly concentric shells. The average separation between the brightest CO shells is 16″ in the outer envelope, where it appears remarkably constant. Closer to the star (< 40″), the shell pattern is denser and less regular, showing intermediary arcs. Outside the small (r < 0.3″) dust formation zone, the gas appears to expand radially at a constant velocity, 14.5 km s-1, with small turbulent motions. Based on that property, we have reconstructed the 3-D structure of the outer envelope and have derived the gas temperature and density radial profiles in the inner (r < 25″) envelope. The shell-intershell density contrast is found to be typically 3. The over-dense shells have spherical or slightly oblate shapes and typically extend over a few steradians, implying isotropic mass loss. The regular spacing of shells in the outer envelope supports the model of a binary star system with a period of 700 years and a near face-on elliptical orbit. The companion fly-by triggers enhanced episodes of mass loss near periastron. The densification of the shell pattern observed in the central part of the envelope suggests a more complex scenario for the last few thousand years.

Trends in Penile Prosthetics: Influence of Patient Demographics, Surgeon Volume, and Hospital Volume on Type of Penile Prosthesis Inserted in New York State

INTRODUCTION

Penile prostheses (PPs) are a discrete, well-tolerated treatment option for men with medical refractory erectile dysfunction. Despite the increasing prevalence of erectile dysfunction, multiple series evaluating inpatient data have found a decrease in the frequency of PP surgery during the past decade.

AIMS

To investigate trends in PP surgery and factors affecting the choice of different PPs in New York State.

METHODS

This study used the New York State Department of Health Statewide Planning and Research Cooperative (SPARCS) data cohort that includes longitudinal information on hospital discharges, ambulatory surgery, emergency department visits, and outpatient services. Patients older than 18 years who underwent inflatable or non-inflatable PP insertion from 2000 to 2014 were included in the study.

OUTCOMES

Influence of patient demographics, surgeon volume, and hospital volume on type of PP inserted.

RESULTS

Since 2000, 14,114 patients received PP surgery in New York State; 12,352 PPs (88%) were inflatable and 1,762 (12%) were non-inflatable, with facility-level variation from 0% to 100%. There was an increasing trend in the number of annual procedures performed, with rates of non-inflatable PP insertion decreasing annually (P < .01). More procedures were performed in the ambulatory setting over time (P < .01). Important predictors of device choice were insurance type, year of insertion, hospital and surgeon volume, and the presence of comorbidities.

CLINICAL IMPLICATIONS

Major influences in choice of PP inserted include racial and socioeconomic factors and surgeon and hospital surgical volume.

STRENGTHS AND LIMITATIONS

Use of the SPARCS database, which captures inpatient and outpatient services, allows for more accurate insight into trends in contrast to inpatient sampling alone. However, SPARCS is limited to patients within New York State and the results might not be generalizable to men in other states. Also, patient preference was not accounted for in these analyses, which can play a role in PP selection.

CONCLUSIONS

During the past 14 years, there has been an increasing trend in inflatable PP surgery for the management of erectile dysfunction. Most procedures are performed in the ambulatory setting and not previously captured by prior studies using inpatient data. Kashanian JA, Golan R, Sun T, et al. Trends in Penile Prosthetics: Influence of Patient Demographics, Surgeon Volume, and Hospital Volume on Type of Penile Prosthesis Inserted in New York State. J Sex Med 2018;15:245-250.

The growth of carbon chains in IRC +10216 mapped with ALMA

Linear carbon chains are common in various types of astronomical molecular sources. Possible formation mechanisms involve both bottom-up and top-down routes. We have carried out a combined observational and modeling study of the formation of carbon chains in the C-star envelope IRC +10216, where the polymerization of acetylene and hydrogen cyanide induced by ultraviolet photons can drive the formation of linear carbon chains of increasing length. We have used ALMA to map the emission of λ 3 mm rotational lines of the hydrocarbon radicals C2H, C4H, and C6H, and the CN-containing species CN, C3N, HC3N, and HC5N with an angular resolution of ~1″. The spatial distribution of all these species is a hollow, 5-10″ wide, spherical shell located at a radius of 10-20″ from the star, with no appreciable emission close to the star. Our observations resolve the broad shell of carbon chains into thinner sub-shells which are 1-2″ wide and not fully concentric, indicating that the mass loss process has been discontinuous and not fully isotropic. The radial distributions of the species mapped reveal subtle differences: while the hydrocarbon radicals have very similar radial distributions, the CN-containing species show more diverse distributions, with HC3N appearing earlier in the expansion and the radical CN extending later than the rest of the species. The observed morphology can be rationalized by a chemical model in which the growth of polyynes is mainly produced by rapid gas-phase chemical reactions of C2H and C4H radicals with unsaturated hydrocarbons, while cyanopolyynes are mainly formed from polyynes in gas-phase reactions with CN and C3N radicals.

Partial Gland Treatment of Prostate Cancer Using High-Intensity Focused Ultrasound in the Primary and Salvage Settings: A Systematic Review

PURPOSE

Advances in prostate imaging, biopsy and ablative technologies have been accompanied by growing enthusiasm for partial gland ablation, particularly using high-intensity focused ultrasound, to treat prostate cancer. Preserving noncancerous prostate tissue and minimizing damage to the neurovascular bundles and external urethral sphincter may improve functional outcomes.

MATERIALS AND METHODS

A systematic review was performed following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using a combination of MeSH® terms, free text search and examination of relevant bibliographies using MEDLINE® and Embase® from the inception of each database through October 10, 2016. We excluded studies describing exclusively whole gland ablation, case reports and series where treatment was followed by immediate resection.

RESULTS

A total of 13 studies that enrolled 543 patients were included. Of the studies 11 were performed in the primary setting and 2 in the salvage setting. Median followup ranged from 6 months to 10.6 years. Rates of posttreatment erectile dysfunction and urinary incontinence ranged from 0% to 48% and 0% to 50%, respectively, with definitions varying by study. Overall there were 254 reported complications. Marked heterogeneity between studies limited the ability to pool results regarding functional and oncologic outcomes. A total of 76 patients (14%) subsequently received further oncologic treatment.

CONCLUSIONS

Early evidence suggests that partial gland ablation is a safe treatment option for men with localized disease. Longer term data are needed to evaluate oncologic efficacy and functional outcomes, and will aid in identifying the optimal candidates for therapy. Standardization of outcomes definitions will allow for better comparison between studies and among treatment modalities.

Discovery of SiCSi in IRC +10216: A missing link between gas and dust carriers of Si-C bonds

We report the discovery in space of a disilicon species, SiCSi, from observations between 80 and 350 GHz with the IRAM 30m radio telescope. Owing to the close coordination between laboratory experiments and astrophysics, 112 lines have now been detected in the carbon-rich star CW Leo. The derived frequencies yield improved rotational and centrifugal distortion constants up to sixth order. From the line profiles and interferometric maps with the Submillimeter Array, the bulk of the SiCSi emission arises from a region of 6″ in radius. The derived abundance is comparable to that of SiC2. As expected from chemical equilibrium calculations, SiCSi and SiC2 are the most abundant species harboring a Si-C bond in the dust formation zone and certainly both play a key role in the formation of SiC dust grains.

The angiotensin type 2 receptor agonist Compound 21 elicits cerebroprotection in endothelin-1 induced ischemic stroke

Evidence indicates that angiotensin II type 2 receptors (AT2R) exert cerebroprotective actions during stroke. A selective non-peptide AT2R agonist, Compound 21 (C21), has been shown to exert beneficial effects in models of cardiac and renal disease, as well as hemorrhagic stroke. Here, we hypothesize that C21 may exert beneficial effects against cerebral damage and neurological deficits produced by ischemic stroke. We determined the effects of central and peripheral administration of C21 on the cerebral damage and neurological deficits in rats elicited by endothelin-1 induced middle cerebral artery occlusion (MCAO), a model of cerebral ischemia. Rats infused centrally (intracerebroventricular) with C21 before endothelin-1 induced MCAO exhibited significant reductions in cerebral infarct size and the neurological deficits produced by cerebral ischemia. Similar cerebroprotection was obtained in rats injected systemically (intraperitoneal) with C21 either before or after endothelin-1 induced MCAO. The protective effects of C21 were reversed by central administration of an AT2R inhibitor, PD123319. While C21 did not alter cerebral blood flow at the doses used here, peripheral post-stroke administration of this agent significantly attenuated the MCAO-induced increases in inducible nitric oxide synthase, chemokine (C-C) motif ligand 2 and C-C chemokine receptor type 2 mRNAs in the cerebral cortex, indicating that the cerebroprotective action is associated with an anti-inflammatory effect. These results strengthen the view that AT2R agonists may have potential therapeutic value in ischemic stroke, and provide the first evidence of cerebroprotection induced by systemic post stroke administration of a selective AT2R agonist.

Peripheral administration of prokineticin 2 potently reduces food intake and body weight in mice via the brainstem

BACKGROUND AND PURPOSE

Prokineticin 2 (PK2) has recently been shown to acutely reduce food intake in rodents. We aimed to determine the CNS sites and receptors that mediate the anorectic effects of peripherally administered PK2 and its chronic effects on glucose and energy homeostasis.

EXPERIMENTAL APPROACH

We investigated neuronal activation following i.p. administration of PK2 using c-Fos-like immunoreactivity (CFL-IR). The anorectic effect of PK2 was examined in mice with targeted deletion of either prokineticin receptor 1 (PKR1) or prokineticin receptor 2 (PKR2), and in wild-type mice following administration of the PKR1 antagonist, PC1. The effect of IP PK2 administration on glucose homeostasis was investigated. Finally, the effect of long-term administration of PK2 on glucose and energy homeostasis in diet-induced obese (DIO) mice was determined.

KEY RESULTS

I.p. PK2 administration significantly increased CFL-IR in the dorsal motor vagal nucleus of the brainstem. The anorectic effect of PK2 was maintained in mice lacking the PKR2 but abolished in mice lacking PKR1 and in wild-type mice pre-treated with PC1. DIO mice treated chronically with PK2 had no changes in glucose levels but significantly reduced food intake and body weight compared to controls.

CONCLUSIONS AND IMPLICATIONS

Together, our data suggest that the anorectic effects of peripherally administered PK2 are mediated via the brainstem and this effect requires PKR1 but not PKR2 signalling. Chronic administration of PK2 reduces food intake and body weight in a mouse model of human obesity, suggesting that PKR1-selective agonists have potential to be novel therapeutics for the treatment of obesity.

Cerebellin1 is a novel orexigenic peptide

AIM

Cerebellin1 (Cbln1) is highly expressed in the hypothalamus, a region of the brain involved in appetite regulation. However, the effects of Cbn1 on food intake are not known. The present study aimed to investigate the effect of Cbln1 on appetite regulation in rats.

METHODS

We determined the effect of (i) intracerebroventricular (ICV) injection of Cbln1 on food intake, behaviour and plasma pituitary hormone levels in male Wistar rats; (ii) Cbln1 on the release of hypothalamic neuropeptides known to modulate food intake from hypothalamic explants and (iii) fasting on hypothalamic Cbln1 mRNA expression.

RESULTS

(i) ICV administration of Cbln1 significantly increased food intake in rats and caused no adverse behaviours. ICV administration of Cbln1 significantly reduced plasma thyroid stimulating hormone (TSH) levels 10 min postinjection in rats. (ii) Cbln1 significantly increased the release of neuropeptide Y (NPY) from hypothalamic explants. (iii) Cbln1 mRNA expression levels were increased in the ventromedial nucleus of the hypothalamus in fasted rats.

CONCLUSIONS

These data suggest that Cbln1 is a novel orexigenic peptide, which may mediate its effects via hypothalamic NPY.

Comparative development and evaluation of topical gel and cream formulations of psoralen

The aim of the present investigation is to develop topical gel and cream formulations of psoralen for enhancing its transport through the skin, with the goal to shorten the delay between drug application and UVA irradiation. In our first studies, oil-in-water (O/W) creams of psoralen (0.05% concentration) were prepared using Apifil (PEG-8 Beeswax) and Plurol Stearique WL 1009 as emulsifying agents and aqueous cream (British Pharmaceutical Codex) as the cream base material. In our second studies, hydroalcoholic transparent gel formulations of this drug in a 0.05% concentration were prepared using hydroxypropylcellulose (HPC) as the gelling agent. The physicochemical compatibility between psoralen and formulation excipients used in the cream and gel formulations was confirmed by using differential scanning calorimetry and Fourier transform infrared spectroscopy. All prepared cream and gel formulations were evaluated for drug content uniformity, viscosity, pH, stability, and limpidity. The release of psoralen from all formulations via dialysis through a cellulose membrane into phosphate buffer pH 6.8 at 37°C was studied. The penetration enhancing effect of menthol (0-12.5%, w/w) on the percutaneous flux of psoralen through excised rat epidermis from gel and cream formulations was also investigated. The release profile of psoralen from gel formulations was higher than that from cream formulations. The percutaneous flux and enhancement ratio of psoralen across rat epidermis was significantly enhanced by the addition of menthol in both gel and cream formulations as compared to gel and cream formulations prepared without menthol (p < 0.05).

Developmentally spliced PKCbetaII provides a possible link between mTORC2 and Akt kinase to regulate 3T3-L1 adipocyte insulin-stimulated glucose transport

Functional adipocyte glucose disposal is a key component of global glucose homeostasis. PKCbetaII is involved in rat skeletal muscle cell ISGT. Western blot analysis and real-time PCR revealed 3T3-L1 cells developmentally regulated PKCbeta splicing such that PKCbetaI was downregulated and PKCbetaII was upregulated during the course of differentiation. An initial glucose uptake screen using PKC inhibitor LY379196 pointed to a PKC isozyme other than PKCzeta mediating 3T3-L1 adipocyte ISGT. Subsequent use of PKCbetaII inhibitor CGP53353 pointed to a role for PKCbetaII in ISGT. Western blot analysis showed that CGP53353 specifically inhibited phosphorylation of PKCbetaII Serine 660. Subcellular fractionation and immunofluorescence demonstrated that PKCbetaII regulates GLUT4 translocation. Further Western blot, immunofluorescence and co-immunoprecipitation analysis reveal that PKCbetaII inhibition does not affect mTORC2 activity yet abrogates phosphorylation of Akt Serine 473. PKCbetaII regulates GLUT4 translocation by regulating Akt phosphorylation and thus activity.

The thyroid hormone derivative 3-iodothyronamine increases food intake in rodents

BACKGROUND

The thyroid hormone derivative 3-iodothyronamine (T(1)AM), an endogenous biogenic amine, is a potent agonist of the G protein-coupled trace amine-associated receptor 1 (TAAR1). T(1)AM is present in rat brain, and TAAR1 is expressed in hypothalamic nuclei associated with the regulation of energy homeostasis.

AIM

The aim of this study was to determine the effects of T(1)AM on food intake in rodents.

METHODS

We determined the effect of (i) intraperitoneal (i.p.) administration of T(1)AM on food intake, oxygen consumption (VO(2)) and locomotor activity in mice; (ii) intracerebroventricular (ICV) injection of T(1)AM on food intake in male rats; (iii) c-fos expression following ventricular administration of T(1)AM in male rats; and (iv) direct injection of T(1)AM into the arcuate nucleus (ARC) of male rats on food intake.

RESULTS

(i) T(1)AM (4 nmol/kg) significantly increased food intake following i.p. injection in mice but had no effect on VO(2) or locomotor activity. (ii) ICV administration of T(1)AM (1.2 nmol/kg) significantly increased food intake in male rats. (iii) Intraventricular administration of T(1)AM significantly increased c-fos expression in the ARC of male rats. (iv) Direct administration of T(1)AM (0.12, 0.4 and 1.2 nmol/kg) into the ARC of male rats significantly increased food intake.

CONCLUSION

These data suggest that T(1)AM is an orexigenic factor that may act through the ARC to increase food intake in rodents.

Symptomatic refractures after vertebroplasty in patients with steroid-induced osteoporosis

BACKGROUND AND PURPOSE

Refracture after percutaneous vertebroplasty in patients receiving oral glucocorticoid therapy has caused some patients and referring physicians to have negative perceptions concerning the efficacy of the initial vertebroplasty treatment. The purpose of this study was to analyze symptomatic refractures after vertebroplasty in patients on oral steroid therapy. We hypothesized that the higher refracture rate of patients on oral glucocorticoid therapy after percutaneous vertebroplasty is due not to an inadequacy of the procedure but rather to a naturally higher predisposition of these patients to refracture compared with patients with primary osteoporosis.

METHODS

A retrospective analysis was performed on all osteoporosis patients having initial vertebroplasty from August 1999 to August 2003. The follow-up period was limited to 1 year after initial vertebroplasty session, with the last follow-up date ending in August 2004. Data were collected on 387 osteoporosis patients.

RESULTS

Of the patients with primary osteoporosis, 20.6% patients refractured whereas 37.8% of the patients with steroid-induced osteoporosis had symptomatic refractures within 1 year of initial vertebroplasty. Relative risk of refracture within 1 year for the patients with steroid-induced osteoporosis was 1.84 compared with the patients with primary osteoporosis. In addition, the patients with steroid-induced osteoporosis were more likely to refracture after their second treatment session (within 1 year of initial vertebroplasty) than those with primary osteoporosis.

CONCLUSION

Patients presenting on oral steroid therapy at their initial vertebroplasty are almost twice more likely to have symptomatic refractures than primary osteoporosis patients within 1 year of initial vertebroplasty.

Fatal fat embolism after vertebroplasty: identification of the high-risk patient

We report a rare complication of autopsy-proven fat and bone marrow embolization following percutaneous vertebroplasty in a patient who had no evidence of cement leakage. Cement injection was done during one patient encounter, covering 3 vertebral levels by using a unipedicular approach. Patients may have complications even without polymethylmethacrylate leakage.

Neoadjuvant chemotherapy for locally advanced breast cancer results in alterations in preoperative tumor marker status

Neoadjuvant therapy followed by breast-conserving surgery has become an acceptable option for patients with locally advanced breast cancer. Although a distinct survival benefit has not been demonstrated using this approach, several questions have been raised following such therapy including its effects on receptor status and tumor markers. The current study retrospectively reviews estrogen receptor (ER), progesterone receptor (PR), and HER2-neu status in 55 consecutive patients treated by neoadjuvant chemotherapy. Preoperative and postoperative tumor markers were available for 43 of the 55 patients (78%). The pathologic complete tumor response rate (pCR) for this group was 19 per cent (8/43). Of those patients who did not achieve a pCR (n = 35), a change in tumor markers was seen in 25.7 per cent (9/35) of patients. When compared to a control group not undergoing neoadjuvant therapy, a significantly higher percent change in marker expression was noted in the neoadjuvant group (25.7% vs 5.9%, P = 0.046). ER, PR, and HER2-neu status remain important prognostic indicators for breast cancer. Tumor markers are useful in planning adjuvant therapy regimens. In this review, nearly 19 per cent of patients achieved a pCR. In patients not achieving a pCR, one in four patients had at least one change in tumor marker status. This study demonstrates the importance of establishing receptor and marker status prior to neoadjuvant therapy, as many patients will achieve a pCR and make tumor analysis impossible. Postoperative marker studies should be performed given the possibility of a change in status. The clinical relevance of this data will require further long-term follow-up. Until such data becomes available, caution should be considered when basing adjuvant therapy regimens on preoperative tumor marker studies alone.

Accurate axillary nodal staging can be achieved after neoadjuvant therapy for locally advanced breast cancer

Lymph node status remains the most important prognostic indicator for breast cancer. Recent reports have established that the accuracy of assessing lymph node status is proportional to the number of nodes dissected. The accuracy of axillary staging following neoadjuvant chemotherapy has been cited as a technical concern due to limited node retrieval. The current study attempts to evaluate the ability to perform sentinel node biopsy (SNB) and formal axillary node dissection (AND) following neoadjuvant chemotherapy and to compare these results with non-neoadjuvant patients. One hundred sixteen consecutive patients undergoing SNB with simultaneous AND were retrospectively reviewed. Forty-two of these patients were treated with neoadjuvant chemotherapy prior to AND. Overall success rate in performing SNB in the neoadjuvant group was 95 per cent, and no false negatives have been noted to date. The overall SNB success rate in the non-neoadjuvant group was also 95 per cent with a false negative rate of 3 per cent. After AND in each group, a mean of 21 nodes were retrieved in the neoadjuvant group and 17.9 nodes in the non-neoadjuvant group (P = 0.018). In the neoadjuvant group, there were 19 node positive patients (42%) and 21 patients (28%) in the non-neoadjuvant group (P = 0.16). The mean number of positive nodes per patient was also similar between the two groups (2.9 in the neoadjuvant group vs 1.67 in the non-neoadjuvant group, P = 0.10). Following neoadjuvant therapy, accurate evaluation of the axilla is feasible. In this study, the mean number of nodes is significantly different in favor of the neoadjuvant group, but there is no significant difference in the number of node positive patients identified or in the mean number of positive nodes identified per patient. SNB is technically feasible with accuracy similar to that seen in patients with no history of neoadjuvant therapy. Neoadjuvant chemotherapy extends the use of breast-conserving therapy without sacrificing the ability to accurately stage the axilla either by use of standard axillary dissection or SNB.

Optical coherence tomographic elastography technique for measuring deformation and strain of atherosclerotic tissues

OBJECTIVES

To evaluate optical coherence tomographic elastography as a method for assessing the elastic properties of atherosclerotic plaque and the parameters that influence interpretation.

METHODS

Phantoms and aorta were examined in vitro to quantify speckle modulation and measure the displacement and strain maps. A correlation method was used as a speckle tracking technique for measuring axial and lateral displacement vectors and calculation of strain maps. The influence of correlation kernel size on accuracy of the method was evaluated.

RESULTS

In terms of a percentage error between calculated and measured displacements, the best results for phantoms were obtained with a 41 x 41 kernel (1.88% error). For both phantom and aorta images, it was found that, with the increasing size of cross correlation kernel, the axial and lateral displacement maps are less noisy and the displacement vectors are more clearly defined. However, the large kernels tend to average out the differences in displacements of small particles in phantoms and decrease the ability of speckle tracking to make microstructural assessments. Therefore, it is important to select kernel size carefully, based on the image features.

CONCLUSIONS

Optical tomographic elastography can be used to assess the microstructural properties of atherosclerotic tissue at micrometre scale resolution, but preselected analysis criteria must be understood in a critical interpretation of the results.

A new approach for assessing early osteoarthritis in the rat

Several animal models have been developed to investigate osteoarthritis and potential disease-modifying therapeutics. However, early disease data from these models are limited by the resolution of current imaging modalities. In this in-vitro study, an optical coherence tomography (OCT) system with an axial resolution of 15 micro m was used to track sequential changes in osteoarthritic rat knees. Osteoarthritis was induced via transection of the medial collateral ligament and an artificial full thickness meniscal tear. Imaging occurred at one, two, and three weeks after surgery. OCT successfully detected early signs of osteoarthritic change, including alteration of the cartilage surface and disruption of the bone-cartilage interface. This study demonstrates that OCT, along with the induction of mechanical injury, provides an excellent model for monitoring the sequential changes of osteoarthritis.

Insulin regulates alternative splicing of protein kinase C beta II through a phosphatidylinositol 3-kinase-dependent pathway involving the nuclear serine/arginine-rich splicing factor, SRp40, in skeletal muscle cells

Insulin regulates the inclusion of the exon encoding protein kinase C (PKC) betaII mRNA. In this report, we show that insulin regulates this exon inclusion (alternative splicing) via the phosphatidylinositol 3-kinase (PI 3-kinase) signaling pathway through the phosphorylation state of SRp40, a factor required for insulin-regulated splice site selection for PKCbetaII mRNA. By taking advantage of a well known inhibitor of PI 3-kinase, LY294002, we demonstrated that pretreatment of L6 myotubes with LY294002 blocked insulin-induced PKCbetaII exon inclusion as well as phosphorylation of SRp40. In the absence of LY294002, overexpression of SRp40 in L6 cells mimicked insulin-induced exon inclusion. When antisense oligonucleotides targeted to a putative SRp40-binding sequence in the betaII-betaI intron were transfected into L6 cells, insulin effects on splicing and glucose uptake were blocked. Taken together, these results demonstrate a role for SRp40 in insulin-mediated alternative splicing independent of changes in SRp40 concentration but dependent on serine phosphorylation of SRp40 via a PI 3-kinase signaling pathway. This switch in PKC isozyme expression is important for increases in the glucose transport effect of insulin. Significantly, insulin regulation of PKCbetaII exon inclusion occurred in the absence of cell growth and differentiation demonstrating that insulin-induced alternative splicing of PKCbetaII mRNA in L6 cells occurs in response to a metabolic change.

Dexamethasone affects cytokine-mediated adhesion of HL-60 human promyelocytic leukemia cells to cultured dermal microvascular endothelial cells

Leukocyte endothelial adhesion (LEA) is the prelude to a complex cascade of reactions following an immunological challenge. Recently, LEA has been implicated in the molecular basis of several dermatological disorders. While the role of proinflammatory cytokines, such as interleukin-1 beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha), in LEA has been investigated using nondermal models, limited data exist regarding their effects on LEA in dermal models. This study shows that cotreatment of cultured human dermal endothelial cells (CADMEC) with IL-1beta and TNF-alpha resulted in a marked increase in the adherence of human promyelocytic leukemia (HL-60) cells to CADMEC and an increase in expression of intercellular adhesion molecule-1 and E-selectin. Pretreatment of CADMEC with dexamethasone, a long-lasting glucocorticoid, resulted in a decrease in both HL-60 cell adhesion to CADMEC and adhesion molecule expression. Taken together, these data demonstrate that LEA may play a role in inflammatory skin conditions and in the mechanisms underlying the potential use of glucocorticoids as a treatment option.

Spherical episodic ejection of material from a young star

The exact processes by which interstellar matter condenses to form young stars are of great interest, in part because they bear on the formation of planets like our own from the material that fails to become part of the star. Theoretical models suggest that ejection of gas during early phases of stellar evolution is a key mechanism for removing excess angular momentum, thereby allowing material to drift inwards towards the star through an accretion disk. Such ejections also limit the mass that can be accumulated by the stellar core. To date, these ejections have been observed to be bipolar and highly collimated, in agreement with theory. Here we report observations at very high angular resolution of the proper motions of an arc of water-vapour masers near a very young, massive star in Cepheus. We find that the arc of masers can be fitted to a circle with an accuracy of one part in a thousand, and that the structure is expanding. Only a sphere will always produce a circle in projection, so our observations strongly suggest that the perfectly spherical ejection of material from this star took place about 33 years earlier. The spherical symmetry of the ejecta and its episodic nature are very surprising in the light of present theories.