Comparison of Radial Versus Femoral Access for Neuroendovascular Procedures in Very High Body Mass Index Individuals

BACKGROUND

Femoral access (TFA) for neuroendovascular procedures may present a challenge in very high body mass index (BMI) individuals. Whether radial access (TRA) confers a comparative benefit in this specific population has not been studied.

METHODS

We retrospectively identified all patients undergoing neuroendovascular procedures at our center between 2017 and 2021 with BMI ≥35 kg/m2. A total of 335 patients met our inclusion criteria, with 224 undergoing femoral access and 111 undergoing radial access. Electronic medical records were reviewed for baseline clinical and angiographic characteristics and procedural outcomes.

RESULTS

The primary outcome of any bleeding complication occurred in 7% of the femoral group and 2% of the radial group (odds ratio 4.2, 95% confidence interval 1.0-18.6, P = 0.0421). Radial access was also associated with significantly shorter mean procedure times (median 43 minutes for radial, median 58 minutes for femoral, P = 0.0009) and mean fluoroscopy exposure times (median 15 minutes for radial, median 20 minutes for femoral, P = 0.0003). There were no significant differences in nonaccess site complications, procedural failure, length of stay, or deaths during hospitalization.

CONCLUSIONS

When compared to TRA, TFA was associated with a significantly greater rate of bleeding complications in very high BMI patients undergoing neuroendovascular procedures. Procedure time and fluoroscopy time were both significantly longer when using TFA compared to TRA in this patient population.

Clinical relevance of intracranial hemorrhage after thrombectomy versus medical management for large core infarct: a secondary analysis of the SELECT2 randomized trial

BACKGROUND

The incidence of intracerebral hemorrhage (ICH) and its effect on the outcomes after endovascular thrombectomy (EVT) for patients with large core infarcts have not been well-characterized.

METHODS

SELECT2 trial follow-up imaging was evaluated using the Heidelberg Bleeding Classification (HBC) to define hemorrhage grade. The association of ICH with clinical outcomes and treatment effect was examined.

RESULTS

Of 351 included patients, 194 (55%) and 189 (54%) demonstrated intracranial and intracerebral hemorrhage, respectively, with a higher incidence in EVT (134 (75%) and 130 (73%)) versus medical management (MM) (60 (35%) and 59 (34%), both P<0.001). Hemorrhagic infarction type 1 (HBC=1a) and type 2 (HBC=1b) accounted for 93% of all hemorrhages. Parenchymal hematoma (PH) type 1 (HBC=1c) and type 2 (HBC=2) were observed in 1 (0.6%) EVT-treated and 4 (2.2%) MM patients. Symptomatic ICH (sICH) (SITS-MOST definition) was seen in 0.6% EVT patients and 1.2% MM patients. No trend for ICH with core volumes (P=0.10) or Alberta Stroke Program Early CT Score (ASPECTS) (P=0.74) was observed. Among EVT patients, the presence of any ICH did not worsen clinical outcome (modified Rankin Scale (mRS) at 90 days: 4 (3-6) vs 4 (3-6); adjusted generalized OR 1.00, 95% CI 0.68 to 1.47, P>0.99) or modify EVT treatment effect (Pinteraction=0.77).

CONCLUSIONS

ICH was present in 75% of the EVT population, but PH or sICH were infrequent. The presence of any ICH did not worsen functional outcomes or modify EVT treatment effect at 90-day follow-up. The high rate of hemorrhages overall still represents an opportunity for adjunctive therapies in EVT patients with a large ischemic core.

The Evolving Role of Postgraduate Year 7 in Neurological Surgery Residency

BACKGROUND AND OBJECTIVES

In 2013, all neurosurgery programs were mandated to adopt a 7-year structure. We sought to characterize how programs use the seventh year of training (postgraduate year 7 [PGY7]).

METHODS

We surveyed all accredited neurosurgery programs in the United States regarding the PGY7 residents' primary role and the availability of enfolded fellowships. We compiled responses from different individuals in each program: chair, program director, program coordinator, and current chiefs.

RESULTS

Of 120 accredited neurological surgery residency programs within the United States, 91 (76%) submitted responses. At these programs, the primary roles of the PGY7 were chief of service (COS, 71%), enfolded fellowships (EFF, 18%), transition to practice (10%), and elective time (1%). Most residencies have been 7-year programs for >10 years (52, 57%). Sixty-seven programs stated that they offer some form of EFF (73.6%). The most common EFFs were endovascular (57, 62.6%), spine (49, 53.9%), critical care (41, 45.1%), and functional (37, 40.7%). These were also the most common specialties listed as Committee on Advanced Subspecialty Training accredited by survey respondents. Spine and endovascular EFFs were most likely to be restricted to PGY7 (24.2% and 23.1%, respectively), followed by neuro-oncology (12, 13.2%). The most common EFFs reported as Committee on Advanced Subspecialty Training accredited but not restricted to PGY7 were endovascular (24, 26.4%) and critical care (23, 25.3%).

CONCLUSION

Most accredited neurological surgery training programs use the COS as the primary PGY7 role. Programs younger in their PGY7 structure seem to maintain the traditional COS role. Those more established seem to be experimenting with various roles the PGY7 year can fill, including enfolded fellowships and transition-to-practice years, predominantly. Most programs offer some form of enfolded fellowship. This serves as a basis for characterization of how neurological surgery training may develop in years to come.

Surgical Strategies in the Treatment of Giant Pituitary Adenomas

BACKGROUND AND OBJECTIVES

The management of giant pituitary adenomas (GPAs) is challenging due to associated endocrinopathies and the close proximity of these tumors to critical structures, such as the optic nerves, structures of the cavernous sinus, and hypothalamus. The objective of this review article was to summarize the current management strategies for giant pituitary adenomas, including the role of open and endoscopic surgical approaches and the role of medical and radiation therapy in conjunction with surgery.

METHODS

We conducted a retrospective review of GPAs operated at our institute between January 2010 and March 2023. Surgical approaches, extent of resection, and associated complications were documented. Furthermore, we conducted a thorough literature review to identify relevant studies published in the past decade, which were incorporated along with insights gained from our institutional case series of GPAs to analyze and integrate both the existing knowledge base and our institution's firsthand experience in the management of GPAs.

RESULTS

A total of 46 giant pituitary adenomas (GPAs) were operated on, using various surgical approaches. Transsphenoidal approach was used in 25 cases and a staged approach using transsphenoidal and pterional was used in 15 cases. Other approaches included transcortical-transventricular, transcallosal, pterional/orbitozygomatic, and subfrontal approaches. Complications and technical nuances were reported.

CONCLUSION

The management of giant pituitary adenomas remains complex, often involving several modalities-open or endoscopic resection, radiosurgery, and medical management of both the tumor and associated endocrinopathies. Surgical resections are often challenging procedures that require careful consideration of several factors, including patient characteristics, tumor location, and size, and the experience and skill of the surgical team.

Feasibility of robotic neuroendovascular surgery

BACKGROUND

Several recent reports of CorPath GRX vascular robot (Cordinus Vascular Robotics, Natick, MA) use intracranially suggest feasibility of neuroendovascular application. Further use and development is likely. During this progression it is important to understand endovascular robot feasibility principles established in cardiac and peripheral vascular literature which enabled extension intracranially. Identification and discussion of robotic proof of concept principals from sister disciplines may help guide safe and accountable neuroendovascular application.

OBJECTIVE

Summarize endovascular robotic feasibility principals established in cardiac and peripheral vascular literature relevant to neuroendovascular application.

METHODS

Searches of PubMed, Scopus and Google Scholar were conducted under PRISMA guidelines1 using MeSH search terms. Abstracts were uploaded to Covidence citation review (Covidence, Melbourne, AUS) using RIS format. Pertinent articles underwent full text review and findings are presented in narrative and tabular format.

RESULTS

Search terms generated 1642 articles; 177, 265 and 1200 results for PubMed, Scopus and Google Scholar respectively. With duplicates removed, title review identified 176 abstracts. 55 articles were included, 45 from primary review and 10 identified during literature review. As it pertained to endovascular robotic feasibility proof of concept 12 cardiac, 3 peripheral vascular and 5 neuroendovascular studies were identified.

CONCLUSIONS

Cardiac and peripheral vascular literature established endovascular robot feasibility and efficacy with equivalent to superior outcomes after short learning curves while reducing radiation exposure >95% for the primary operator. Limitations of cost, lack of haptic integration and coaxial system control continue, but as it stands neuroendovascular robotic implementation is worth continued investigation.

Scientific Influence of R01 Grants Issued to Department of Surgery Investigators, 2000 to 2015

This observational study uses citation rates to measure the influence of National Institutes of Health R01 grants issued to department of surgery investigators and compared them according to whether the investigator was a surgeon-scientist or a research-scientist.

Multimodal monitoring to guide neurosurgical intervention in high-grade aneurysmal subarachnoid hemorrhage: illustrative case

BACKGROUND

Multimodal monitoring to guide medical intervention in high-grade aneurysmal subarachnoid hemorrhage (aSAH) is well described. Multimodal monitoring to guide surgical intervention in high-grade aSAH has been less studied.

OBSERVATIONS

Intracranial pressure (ICP), brain lactate to pyruvate ratio (L/P ratio), and brain parenchymal oxygen tension (pO₂) were used as surrogates for clinical status in a comatose man after high-grade aSAH. Acute changes in ICP, L/P ratio, and pO₂ were used to identify brain injury from both malignant cerebral edema and delayed cerebral ischemia, respectively, and decompressive hemicraniectomy with clot evacuation and intraarterial nimodipine were used to treat these conditions. The patient showed marked improvement in multimodal parameters following each intervention and eventually recovered to a modified Rankin score of 2.

LESSONS

In patients with a limited neurological examination due to severe acute brain injury in the setting of aSAH, multimodal monitoring can be used to guide surgical treatment. With prompt, aggressive, maximal medical and surgical interventions, otherwise healthy individuals may retain the capacity for close to full recovery from seemingly catastrophic aSAH.

Difficult airways: a 3D printing study with virtual fibreoptic endoscopy

Head and neck cancer patients present unique airway challenges, and oropharyngeal, laryngeal, and hypopharyngeal tumours considerably distort and narrow the anatomy of the airway. We describe the use of 3D augmented reality software combined with 3D printed models to assess the anatomy of difficult airways and to assist in the formulation of the most optimal airway management strategy in such patients. The reported patients had computed tomograms (CT) of the neck prior to their anaesthetic and surgical management. DICOM files of the respective scans were imported to 3D rendering software (OsiriX, Pixmeo). We constructed volume rendered models for initial assessment of the airway then generated serial surface rendered models to create a virtual endoscopic path of the airway to simulate the fibreoptic approach. To further facilitate the study of difficult airways we have subsequently printed 3D models of those that were most difficult using rapid prototyping. Head and neck tumours significantly distort the airway. Thorough study of the relevant anatomy prior to airway management for operating reasons enhances communication between the surgeon and anaesthetist, and aids selection of the most appropriate intubation approach. In conclusion, this paper highlights a useful and novel pre-assessment strategy that allows a virtual, visual, 3-dimensional assessment of the airway anatomy combined with 3D modelling and 3D printing. This enables the airway specialist, anaesthetist, and head and neck surgeon to anticipate any critical steps and adjust the plan accordingly.

The 25 most cited articles on lateral lumbar interbody fusion: short review

The lateral lumbar interbody fusion technique for lumbar arthrodesis is gaining popularity and being added as an option to traditional posterior and anterior approaches. In light of this, we analyzed the literature to identify the 25 most cited articles regarding lateral lumbar interbody fusion. The Thomson Reuters Web of Science was systematically searched to identify papers pertaining to lateral lumbar interbody fusion. The results were sorted in order to identify the top cited 25 articles. Statistical analysis was applied to determine metrics of interest, and observational studies were further classified. A search of all databases in the Thomson Reuters Web of Science identified 379 articles pertaining to lateral lumbar interbody fusion, with a total of 3800 citations. Of the 25 most cited articles, all were case series, reporting on a total of 2981 patients. These 25 articles were cited 2232 times in the literature and total citations per article ranged from 29 to 433. The oldest article was published in 2006, whereas the most recent article was published in 2015. The most cited article, by Ozgar et al., was cited 433 times, and the journal Spine published 7 of the 25 most cited articles. Herein, we report and analyze the 25 most cited articles on lateral lumbar interbody fusion, which include 25 cases series reporting a variety of data on a total of 2513 patients. Such data might assist in the design and interpretation of future studies pertaining to this topic.

Comparison of Lumbar Laminectomy Alone, Lumbar Laminectomy and Fusion, Stand-alone Anterior Lumbar Interbody Fusion, and Stand-alone Lateral Lumbar Interbody Fusion for Treatment of Lumbar Spinal Stenosis: A Review of the Literature

Lumbar spinal stenosis is defined as narrowing of the lumbar spinal canal, which causes compression of the spinal cord and nerves. Spinal stenosis can cause leg pain and potentially back pain that can affect the quality of life. Ultimately, surgical decompression is required to alleviate the symptoms. In this review, we first utilize several important studies to compare lumbar laminectomy alone versus lumbar laminectomy and fusion. We also compare the effectiveness of more novel surgical approaches, stand-alone anterior lumbar interbody fusion (ALIF), and stand-alone lateral lumbar interbody fusion (LLIF). These techniques have their own advantages and disadvantages in which many factors must be taken into account before choosing a surgical approach. In addition, the patient’s anatomy and pathology, lifestyle, and desires should be analyzed to help determine the ideal surgical strategy

The endocannabinoid system and stroke: A focused review

Stroke is an important cause of morbidity and mortality worldwide. Development of novel neuroprotectants is of paramount importance. This review seeks to summarize the recent evidence for the role of the endocannabinoid signaling system in stroke pathophysiology, as well as the evidence from preclinical studies regarding the efficacy of cannabinoids as neuroprotective therapies in the treatment of stroke. Recent evidence from rodent models implicating cannabinoid 1 receptor (CB1R), cannabinoid 2 receptor (CB2R), and CB1R and CB2R co-antagonism as neuroprotective strategies in stroke are reviewed. Rodent evidence for the therapeutic role of the endocannabinoid system in treating poststroke depression is reviewed. Finally, evidence for the role of cannabidiol, a publicly available cannabinoid that does not bind directly to known endocannabinoid receptors, as a stroke neuroprotectant is also reviewed. The review closes with a consideration of the role of human cannabinoid abuse in stroke and considers future directions for research on endocannabinoid-based stroke therapeutics.

Effect of revascularization on cognitive outcomes in intracranial steno-occlusive disease: a systematic review

OBJECTIVESteno-occlusive diseases of the cerebral vasculature have been associated with cognitive decline. The authors performed a systematic review of the existing literature on intracranial steno-occlusive disease, including intracranial atherosclerosis and moyamoya disease (MMD), to determine the extent and quality of evidence for the effect of revascularization on cognitive performance.METHODSA systematic search of PubMed/MEDLINE, the Thomson Reuters Web of Science Core Collection, and the KCI Korean Journal Database was performed to identify randomized controlled trials (RCTs) in the English-language literature and observational studies that compared cognitive outcomes before and after revascularization in patients with steno-occlusive disease of the intracranial vasculature, from which data were extracted and analyzed.RESULTSNine papers were included, consisting of 2 RCTs and 7 observational cohort studies. Results from 2 randomized trials including 142 patients with symptomatic intracranial atherosclerotic steno-occlusion found no additional benefit to revascularization when added to maximal medical therapy. The certainty in the results of these trials was limited by concerns for bias and indirectness. Results from 7 observational trials including 282 patients found some cognitive benefit for revascularization for symptomatic atherosclerotic steno-occlusion and for steno-occlusion related to MMD in children. The certainty of these conclusions was low to very low, due to both inherent limitations in observational studies for inferring causality and concerns for added risk of bias and indirectness in some studies.CONCLUSIONSThe effects of revascularization on cognitive performance in intracranial steno-occlusive disease remain uncertain due to limitations in existing studies. More well-designed randomized trials and observational studies are needed to determine if revascularization can arrest or reverse cognitive decline in these patients.

Chronic stress induces persistent changes in global DNA methylation and gene expression in the medial prefrontal cortex, orbitofrontal cortex, and hippocampus

Chronic stress is associated with a plethora of cognitive symptoms such as emotional dysregulation and impaired executive function that have been attributed to modifications in neuroanatomy in the orbitofrontal cortex (OFC), medial prefrontal cortex (mPFC), and hippocampus (HPC). While many studies have examined stress-induced changes in neuronal morphology, synaptic plasticity, and cellular function, there has been little investigation into persistent changes in gene expression that may be responsible for the maintenance of these changes. This study exposed adult rats to a chronic stressor and then examined changes in mRNA gene expression in the OFC, mPFC and HPC following a two-week withdrawal period. mRNA bio-sequencing results revealed sex- and region-dependent changes. Surprisingly the greatest changes in gene expression were found in the OFC, and similar to anatomical studies, analysis of gene changes with Ingenuity Pathway Analysis software demonstrated that the mPFC and OFC exhibited contrasting activation of canonical pathways and functional networks. The HPC demonstrated the largest degree of sex-dependent change in gene expression. In general, chronic stress induced persistent changes in gene expression in the three brain regions we examined and these changes could be associated with the commonly reported cognitive symptoms. The current study highlights the region- and sex-dependent nature of the brain's response to chronic stress and the difficulty we face when attempting to develop treatment options.

Safe and prolonged survival with long-term exposure to pomalidomide in relapsed/refractory myeloma

BACKGROUND

The IFM2009-02 trial studied pomalidomide (4 mg daily, 21/28 versus 28/28) and dexamethasone in very advanced relapsed or refractory multiple myeloma (RRMM). We observed that 40% of patients had a prolonged progression-free survival (PFS) and subsequently overall survival (OS). We sought to analyze the characteristics of these patients and study the effect of long exposure to pomalidomide.

DESIGN

We separated the studied population into two groups: 3 months to 1 year (<1 year) and more than 1 year (≥1 year) of treatment with pomalidomide and dexamethasone based on clinical judgment and historical control studies. We then analyzed the characteristics of patients according to duration of treatment.

RESULTS

The overall response rate (ORR) for the <1-year group was 43%, the median PFS 4.6 months [95% confidence interval (95% CI) 3.8-6.4] with only 6% at 12 months, and the median OS was 15 months (11.7-20.3) and 40% at 18 months. For the ≥1-year group, the response rate and survival were strikingly different, ORR at 83%, median PFS 20.7 months (14.7-35.4), median OS not reached, and 91% at 18 months.

CONCLUSION

Pomalidomide and dexamethasone favored prolonged and safe exposure to treatment in 40% of heavily treated and end-stage RRMM, a paradigm shift in the natural history of RRMM characterized with a succession of shorter disease-free intervals and ultimately shorter survival. Although an optimization of pomalidomide-dexamethasone regimen is warranted in advanced RRMM, we claim that pomalidomide has proven once more to change the natural history of myeloma in this series, which should be confirmed in a larger study.

Preconception paternal stress in rats alters dendritic morphology and connectivity in the brain of developing male and female offspring

The goal of this research was to examine the effect of preconception paternal stress (PPS) on the subsequent neurodevelopment and behavior of male and female offspring. Prenatal (gestational) stress has been shown to alter brain morphology in the developing brain, and is presumed to be a factor in the development of some adult psychopathologies. Our hypothesis was that paternal stress in the preconception period could impact brain development in the offspring, leading to behavioral abnormalities later in life. The purpose of this study was to examine the effect of preconception paternal stress on developing male and female offspring brain morphology in five brain areas; medial prefrontal cortex (mPFC), orbitofrontal cortex (OFC), parietal cortex (Par1), hippocampus (CA1) and nucleus accumbens (NAc). Alterations in dendritic measures and spine density were observed in each brain area examined in paternal stress offspring. Our two main findings reveal; (1) PPS alters brain morphology and organization and these effects are different than the effects of stress observed at other ages; and, (2) the observed dendritic changes were sexually dimorphic. This study provides direct evidence that PPS modifies brain architecture in developing offspring, including dendritic length, cell complexity, and spine density. Alterations observed may contribute to the later development of psychopathologies and maladaptive behaviors in the offspring.

[Text Comprehensibility of Hospital Report Cards]

Objectives: Recently, the number of hospital report cards that compare quality of hospitals and present information from German quality reports has greatly increased. Objectives of this study were to a) identify suitable methods for measuring the readability and comprehensibility of hospital report cards, b) to obtain reliable information on the comprehensibility of texts for laymen, c) to give recommendations for improvements and d) to recommend public health actions. Methods: The readability and comprehensibility of the texts were tested with a) a computer-aided evaluation of formal text characteristics (readability indices Flesch (German formula) and 1. Wiener Sachtextformel formula), b) an expert-based heuristic analysis of readability and comprehensibility of texts (counting technical terms and analysis of text simplicity as well as brevity and conciseness using the Hamburg intelligibility model) and c) a survey of subjects about the comprehensibility of individual technical terms, the assessment of the comprehensibility of the presentations and the subjects' decisions in favour of one of the 5 presented clinics due to the better quality of data. In addition, the correlation between the results of the text analysis with the results from the survey of subjects was tested. Results: The assessment of texts with the computer-aided evaluations showed poor comprehensibility values. The assessment of text simplicity using the Hamburg intelligibility model showed poor comprehensibility values (-0.3). On average, 6.8% of the words used were technical terms. A review of 10 technical terms revealed that in all cases only a minority of respondents (from 4.4% to 39.1%) exactly knew what was meant by each of them. Most subjects (62.4%) also believed that unclear terms worsened their understanding of the information offered. The correlation analysis showed that presentations with a lower frequency of technical terms and better values for the text simplicity were better understood. Conclusion: The determination of the frequency of technical terms and the assessment of text simplicity using the Hamburg intelligibility model were suitable methods to determine the readability and comprehensibility of presentations of quality indicators. The analysis showed predominantly poor comprehensibility values and indicated the need to improve the texts of report cards.

Tactile stimulation improves neuroanatomical pathology but not behavior in rats prenatally exposed to valproic acid

Autism is a severe neurodevelopmental disorder with a population prevalence of 1 in 68, and dramatically increasing. While no single pharmacologic intervention has successfully targeted the core symptoms of autism, emerging evidence suggests that postnatal environmental manipulations may offer greater therapeutic efficacy. Massage therapy, or tactile stimulation (TS), early in life has repeatedly been shown to be an effective, low-cost, therapeutic approach in ameliorating the cognitive, social, and emotional symptoms of autism. While early TS treatment attenuates many of the behavioral aberrations among children with autism, the neuroanatomical correlates driving such changes are unknown. The present study assessed the therapeutic effects of early TS treatment on behavior and neuroanatomy using the valproic acid (VPA) rodent model of autism. Rats were prenatally exposed to VPA on gestational day 12.5 and received TS shortly following birth. Whereas TS reversed almost all the VPA-induced alterations in neuroanatomy, it failed to do so behaviorally. The TS VPA animals, when compared to VPA animals, did not exhibit altered or improved behavior in the delayed non-match-to-sample T-maze, Whishaw tray reaching, activity box, or elevated plus maze tasks. Anatomically, however, there were significant increases in dendritic branching and spine density in the medial prefrontal cortex, orbital frontal cortex, and amygdala in VPA animals following early TS treatment, suggesting a complete reversal or remediation of the VPA-induced effects in these regions. The results suggest that postnatal TS, during a critical period in development, acts as a powerful reorganization tool that can ameliorate the neuroanatomical consequences of prenatal VPA exposure.

The development of lasting impairments: a mild pediatric brain injury alters gene expression, dendritic morphology, and synaptic connectivity in the prefrontal cortex of rats

Apart from therapeutic discovery, the study of mild traumatic brain injury (mTBI) has been focused on two challenges: why do a majority of individuals recover with little concern, while a considerable proportion suffer with persistent and often debilitating symptomology; and, how do mild injuries significantly increase risk for an early-onset neurodegeneration? Owing to a lack of observable damage following mTBI, this study was designed to determine if there were changes in neuronal morphology, synaptic connectivity, and epigenetic patterning that could contribute to the manifestation of persistent neurological dysfunction. Prefrontal cortex tissue from male and female rats was used for Golgi-Cox analysis along with the profiling of changes in gene expression (BDNF, DNMT1, FGF2, IGF1, Nogo-A, OXYR, and TERT) and telomere length (TL), following a single mTBI or sham injury in the juvenile period. Golgi-Cox analysis of dendritic branch order, dendritic length, and spine density demonstrate that an early mTBI increases complexity of pyramidal neurons in the mPFC. Furthermore, there are also substantial changes in the expression levels of the seven genes of interest and TL following a single mild injury in this brain region. The results from the neuroanatomical measures and changes in gene expression indicate that the mTBI disrupts normal pruning processes that are typically underway at this point in development. In addition, there are significant interactions between the social environment and epigenetic processes that work in concert to perpetuate neurological dysfunction.

Abstract 187: Absence of S100A9 confers survival advantage in an aggressive de novo mouse model of glioblastoma multiforme

Glioblastoma multiforme (GBM) is the most common (60%) primary brain tumor in adults and constitutes a major challenge for both patients and clinicians, with a median survival of only 15-21 months when treated with surgery, radiation therapy and temozolomide. To improve patient outcome, a promising and safe avenue of adjuvant treatment is immune therapy with dendritic cell vaccines or adoptive T cell transfer. These treatments are however hindered by the immune suppressive environment induced by GBMs. Understanding the mechanisms by which GBM suppress the anti-tumor immune response is paramount in order to develop successful immune therapies.

The Sleeping Beauty transposase system was used to modify the genetic makeup of stem cells in the sub-ventricular zone of neonatal mice and thus induce de novo glioblastomas with several combinations of genes. The most aggressive tumors where induced when combining NRAS and SV-40 Large T antigen (NLgT) generating invasive tumors which show the histological hallmarks human GBM (WHO grade IV) with pseudo-pallisading necrosis, neovascularization and hemorrhages, rendering the mice moribund with a median survival of 30 days.

Myeloid derived suppressive cells, a heterogeneous population of immature bone marrow derived cells, are induced by cancers and other consumptive diseases and strongly inhibit adaptive and innate immune responses. We show that MDSCs isolated from de novo GBMs, inhibit antigen-specific and antigen non-specific T cell proliferation. Tumor infiltrating MDSCs highly express the pro-inflammatory secreted calcium binding protein S100A9 and its cognate receptors RAGE and TLR4. In bone marrow cultures, conditioned media from primary cell lines derived from NLgT tumors induce a marked expansion (60-70%) of myeloid derived suppressor cells (MDSCs) and enhance the expression of S100A9. Mice deficient for S100A9 with de novo NLgT tumors show an increased survival compared to wild-type animals (median survival= 47days, a 56% improvement). Analysis of tumor-infiltrating mononuclear cells in moribund NLgT wild-type and S100A9KO mice shows no significant difference in percent infiltrating MDSCs, macrophages and dendritic cells (% of CD45+), however the percent of CD8+ cytotoxic T lymphocytes is increased in S100A9 KO (16% vs. 6% p=0.0228). In addition, expression of MHCII is increased in macrophages and dendritic cells from S100A9 KO mice when compared to wild type mice.

Taken together these data suggest that the absence of S100A9 confers a survival advantage by allowing a stronger anti-tumor immune response with:(1) increased number of cytotoxic T lymphocytes and (2) increased maturation of antigen presenting cells. Experiments are currently underway to identify the detailed cellular and molecular events, which give rise to this phenotype.

This study was supported by NIH/RO1 NS057711 and NS074387.

Citation Format: Alexandra Calinescu, Hikmat Assi, Bradley Kolb, Carl Koschmann, Pedro R. Lowenstein, John Ohlfest, Maria G. Castro. Absence of S100A9 confers survival advantage in an aggressive de novo mouse model of glioblastoma multiforme. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 187. doi:10.1158/1538-7445.AM2014-187

Juvenile play experience does not affect nicotine sensitization and voluntary consumption of nicotine in adult rats

Juvenile play experiences promote behavioral flexibility in rats. If other early positive experiences, such as tactile stimulation, are given prior to exposure to psychostimulants, the behavioral response to the drug is attenuated. The objective of the present study was to determine if the experience of juvenile play behavior would attenuate the response to nicotine. Two experiments were conducted: (1) behavioral sensitization to nicotine exposure, and (2) voluntary consumption of nicotine. For both experiments, rats were reared either with three same-sex peers (play group) or one adult (no play group) during their juvenile period. Then, as adults, half of each group was exposed to repeated injections of nicotine and the other half to saline. Prior play experience had no effect on behavioral sensitization or on voluntary consumption of nicotine. It remains to be determined whether juvenile experience with play influences the rewarding properties of nicotine in social contexts as adults.

Juvenile play experience primes neurons in the medial prefrontal cortex to be more responsive to later experiences

Juvenile play behavior in rats promotes later behavioral flexibility and appears to do so by modifying the neural systems that regulate the animal's response to unexpected challenges. For example, the experience of play has been shown to prune the dendritic arbor of the cells in the medial prefrontal cortex (mPFC), part of the brain's executive control system. The objective of the present study was to determine if the play-induced changes in the mPFC promotes greater plasticity to experiences later in life. In order to test this possibility, exposure to nicotine was used as the secondary experience given later in life, as it has been shown to produce later changes to the morphology of mPFC pyramidal neurons. Animals were either paired with three same-sex peers (play condition) or one adult (no play condition) during their juvenile period. As young adults, half of the rats from each condition were exposed to repeated injections of nicotine and the other half to injections of saline. The neural plasticity of the mPFC was measured by changes in length and branching of dendrites. Neural changes induced separately by play and by nicotine were consistent with previously published findings. The novel finding was that the cells in the mPFC exhibit a greater response to exposure to nicotine if the rats first had play experience. These findings suggest that juvenile play experiences enhance the plasticity of some neural systems.

Training on motor and visual spatial learning tasks in early adulthood produces large changes in dendritic organization of prefrontal cortex and nucleus accumbens in rats given nicotine prenatally

Experience-dependent plasticity is an ongoing process that can be observed and measured at multiple levels. The first goal of this study was to examine the effects of prenatal nicotine on the performance of rats in three behavioral tasks (elevated plus maze (EPM), Morris water task (MWT), and Whishaw tray reaching). The second goal of this experiment sought to examine changes in dendritic organization following exposure to the behavioral training paradigm and/or low doses of prenatal nicotine. Female Long-Evans rats were administered daily injections of nicotine for the duration of pregnancy and their pups underwent a regimen of behavioral training in early adulthood (EPM, MWT, and Whishaw tray reaching). All offspring exposed to nicotine prenatally exhibited substantial increases in anxiety. Male offspring also showed increased efficiency in the Whishaw tray-reaching task and performed differently than the other groups in the probe trial of the MWT. Using Golgi-Cox staining we examined the dendritic organization of the medial and orbital prefrontal cortex as well as the nucleus accumbens. Participation in the behavioral training paradigm was associated with dramatic reorganization of dendritic morphology and spine density in all brain regions examined. Although both treatments (behavior training and prenatal nicotine exposure) markedly altered dendritic organization, the effects of the behavioral experience were much larger than those of the prenatal drug exposure, and in some cases interacted with the drug effects.

Stress during development alters dendritic morphology in the nucleus accumbens and prefrontal cortex

The long-term effects of stress during development have been well characterized. However, the effects of developmental stress on the underlying neurological mechanisms related to the reward system are not well understood. The present report studied the long term effects of stress during development on the structural plasticity in the cortical and subcortical regions. Rats exposed to stress during embryonic development (prenatal stress; PS) or soon after birth (maternal separation; MS) were studied for structural alteration at the neuronal level in the nucleus accumbens (NAc), orbital frontal cortex (OFC), and medial prefrontal cortex (mPFC). The findings show that stress during development increased dendritic branching, length, and spine density in the NAc, and subregions of the PFC. PS experience increased dendritic branching and length in the mPFC apical and basilar dendrites. In contrast, a PS-associated decrease in dendritic branching and length was observed in the basilar branches of the OFC. MS resulted in an increase in dendritic growth and spine density in the subregions of the PFC. The effect of PS on neuroanatomy was more robust than MS despite the shorter duration and intensity. The altered dendritic growth and spine density associated with stress during development could have potential impact on NAc and PFC related behaviors.

Intensity matters: brain, behaviour and the epigenome of prenatally stressed rats

There is a general consensus that prenatal stress alters offspring brain development, however, the details are often inconsistent. Hypothesizing that variation to the level of stress would produce different maternal experiences; this study was designed to examine offspring outcomes following a single prenatal stress paradigm at two different intensities. Pregnant Long Evans rats received mild, high, or no-stress from gestational days 12-16. Offspring underwent early behavioural testing and global methylation patterns were analysed from brain tissue of the frontal cortex and hippocampus. The two different prenatal stress intensities produced significantly different and often, opposite effects in the developing brain. Mild prenatal stress decreased brain weight in both males and females, whereas extreme stress increased female brain weight. Mild prenatal stress slowed development of sensorimotor abilities and decreased locomotion, whereas high prenatal stress also slowed development of sensorimotor learning but increased locomotion. Finally, mild prenatal stress increased global DNA methylation levels in the frontal cortex and hippocampus whereas high prenatal stress was associated with a dramatic decrease. The data from this study provide evidence to support a dose-dependent effect of prenatal stress on multiple aspects of brain development, potentially contributing to long-term outcomes.

Characteristics of patients with coronary artery disease and hypertension: a report from INVEST

In all, 22,599 patients with coexisting hypertension and coronary artery disease (CAD) from around the world are enrolled in the INternational VErapamil SR/trandolapril STudy (INVEST). As a result, much will be learned regarding the use of treatment strategies using verapamil SR and atenolol with and without trandolapril and/or hydrochlororthiazide in patients with hypertension and CAD, all of whom are at high risk for adverse cardiovascular outcomes. This trial will provide meaningful data on optimal treatment strategies for hypertension, especially among patients who are elderly, have diabetes, have left ventricular hypertrophy, or who are dyslipidemic. This trial will be the first to use Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI) guidelines as blood pressure goals to determine the relative benefits of a calcium antagonist versus a beta-blocker strategy in reducing morbidity and mortality. In addition, women and Hispanic patients participating in INVEST will provide the largest controlled experience in the management of hypertensive patients with CAD, facilitating the development of future guidelines.

Heterogeneity of t(4;14) in multiple myeloma. Long-term follow-up of 100 cases treated with tandem transplantation in IFM99 trials

One hundred de novo multiple myeloma patients with t(4;14) treated with double intensive therapy according to IFM99 protocols were retrospectively analyzed. The median overall survival (OS) and event-free survival (EFS) were 41.4 and 21 months, respectively, as compared to 65 and 37 for patients included in the IFM99 trials without t(4;14) (P<10(-7)). We identified a subgroup of patients presenting at diagnosis with both low beta(2)-microglobulin <4 mg/l and high hemoglobin (Hb) >/=10 g/l (46% of the cases) with a median OS of 54.6 months and a median EFS of 26 months, respectively, which benefits from high-dose therapy (HDT); conversely patients with one or both adverse prognostic factor (high beta(2)-microglobulin and/or low Hb) had a poor outcome. The achievement of either complete response or very good partial response after HDT was also a powerful independent prognostic factor for both OS and EFS.

Chronic inhibition of cyclooxygenase-2 induces dendritic hypertrophy and limited functional improvement following motor cortex stroke

The cyclooxygenase-2 (COX-2) enzyme is part of the inflammatory pathway and is induced within the brain by a variety of pathological events, including ischemia. Pharmacological agents that inhibit COX-2 have been found to be neuroprotective in a number of injury models, and long-term administration of these drugs has been shown to induce plastic changes in the brain. In the current experiment, we investigated the effectiveness of stimulating cortical plasticity following stroke injury through the administration of the COX-2 inhibitor drug NS398. Furthermore, we determined whether the induced plastic changes improved functional outcome following motor cortex stroke. Chronic drug administration was found to induce dendritic hypertrophy in cells in the parietal cortex, and this anatomical change was associated with the animals making significantly more reach attempts, as well as successful reaches during a skilled reaching task. Additional motor tests however revealed that the treatment did not affect the level of motor recovery, as the animals showed chronic impairments in the Schallert cylinder, and the forepaw inhibition tasks. Short-term administration of the drug, immediately following the stroke did not induce any dendritic changes, nor was it found to improve behavioral performance on any of the motor tasks. Based on these results we conclude that the plastic changes that are induced by long-term COX-2 inhibitor administration provide some benefit to functional outcome following ischemic cortical injury.

Enriched environment improves motor function in intact and unilateral dopamine-depleted rats

Previous studies have suggested that experience and environmental conditions can affect the progression and severity of symptoms in Parkinson's disease. Furthermore, earlier reports have indicated that enriched environment promotes the survival of dopaminergic grafts in a rat model of Parkinson's disease. Here we investigated whether environmental enrichment affects normal motor function and the severity of dopamine depletion in a rat model of Parkinson's disease. Adult female Long-Evans rats were pre-trained and tested daily in a skilled reaching task. One group of rats was placed in an enriched environment while one group was housed under standard conditions. During this time period, reaching success of animals exposed to the enriched environment improved as compared with animals living in standard housing. The animals remained in the two housing conditions for six weeks prior to receiving unilateral infusion of the neurotoxin 6-hydroxydopamine into the nigrostriatal bundle. The daily behavioral testing continued up to four weeks after lesion. The observations showed that rats housed in an enriched environment significantly improved in reaching success during the first three weeks after lesion as compared with rats housed in the standard condition. Qualitative movement analysis, drug-induced rotation and histological findings indicate that compensatory processes in particular might have accounted for the behavioral improvements. These data are discussed in relation to possible mechanisms of experience-dependent modulation of the pathology of Parkinson's disease.