Symptomatic obstructive hydrocephalus caused by choroid plexus hyperplasia in a pediatric patient: illustrative case.

BACKGROUND: Choroid plexus hyperplasia has been described as a rare cause of communicating hydrocephalus due to cerebrospinal fluid (CSF) overproduction. However, this is the first report of symptomatic obstructive hydrocephalus caused by mechanical obstruction of the aqueduct by a hyperplastic choroid plexus. OBSERVATIONS: A 4-year-old male presented with headaches and intermittent emesis. Magnetic resonance imaging (MRI) of the brain showed abnormal enlargement of the choroid plexus in the lateral ventricles with extension into the third ventricle, resulting in obstruction of the aqueduct of Sylvius, leading to obstructive hydrocephalus. Endoscopic third ventriculostomy (ETV) was chosen as the surgical treatment. During the procedure, high pressure flow of clear CSF was noted. Normal intraventricular anatomy was identified, and no cyst or tumor was found. The postoperative MRI showed a patent third ventriculostomy, without complication, and a significant decrease in supratentorial ventricular size. The patient was discharged 3 days after surgery with a complete resolution of symptoms. LESSONS: Choroid plexus hyperplasia has the potential to cause obstructive hydrocephalus, and it can be effectively treated with ETV. Our hypothesis is that the change in pressure caused by the procedure may have led to an uncorking of the aqueduct by the hyperplastic choroid plexus, contributing to the observed improvement.

Cerebral microdialysis and glucopenia in traumatic brain injury: A review.

Traditionally, intracranial pressure (ICP) and partial brain tissue oxygenation (PbtO2) have been the primary invasive intracranial measurements used to guide management in patients with severe traumatic brain injury (TBI). After injury however, the brain develops an increased metabolic demand which may require an increment in the oxidative metabolism of glucose. Simultaneously, metabolic, and electrical dysfunction can lead to an inability to meet these demands, even in the absence of ischemia or increased intracranial pressure. Cerebral microdialysis provides the ability to accurately measure local concentrations of various solutes including lactate, pyruvate, glycerol and glucose. Experimental and clinical data demonstrate that such measurements of cellular metabolism can yield critical missing information about a patient's physiologic state and help limit secondary damage. Glucose management in traumatic brain injury is still an unresolved question. As cerebral glucose metabolism may be uncoupled from systemic glucose levels due to the metabolic dysfunction, measurement of cerebral extracellular glucose concentrations could provide more predictive information and prove to be a better biomarker to avoid secondary injury of at-risk brain tissue. Based on data obtained from cerebral microdialysis, specific interventions such as ICP-directed therapy, blood glucose increment, seizure control, and/or brain oxygen optimization can be instituted to minimize or prevent secondary insults. Thus, microdialysis measurements of parenchymal metabolic function provides clinically valuable information that cannot be obtained by other monitoring adjuncts in the standard ICU setting.

Pediatric Vagus Nerve Stimulation: Case Series Outcomes and Future Directions.

BACKGROUND: Vagus nerve stimulation (VNS) is a neuromodulatory procedure most extensively studied as an adjunct to medically refractory epilepsy. Despite widespread adoption and decades of clinical experience, clinical predictors of response to VNS remain unclear. OBJECTIVE: To evaluate a retrospective cohort of pediatric patients undergoing VNS at our institution to better understand who may benefit from VNS and identify factors which may predict response to VNS. METHODS: We conducted a retrospective cohort study examining pediatric patients undergoing VNS over nearly a 20-year span at a single institution. Presurgical evaluation, including demographics, clinical history, and diagnostic electroencephalogram, and imaging findings were examined. Primary outcomes included VNS response. RESULTS: Two hundred ninety-seven subjects were studied. The mean age at surgery was 10.1 (SD = 4.9, range = 0.8-25.3) years; length of follow-up was a mean of 4.6 years (SD = 3.5, median = 3.9 years, range 1 day-16.1 years). There was no association between demographic factors, epilepsy etiology, or genetic basis and VNS outcomes. There was an association between reduction in main seizure type with positive MRI finding. Of all MRI findings analyzed, brain atrophy was significantly associated with worse VNS outcomes, whereas dysplastic hippocampus and chronic periventricular leukomalacia findings were found to be associated with improved outcomes. Increased seizure semiology variability and seizure type were also associated with improved seizure outcomes. CONCLUSION: Predicting response to VNS remains difficult, leading to incompletely realized benefits and suboptimal resource utilization. Specific MRI findings and increased seizure semiology variability and type can help guide clinical decision making and patient counseling.

Neuroablative central lateral thalamotomy for chronic neuropathic pain.

Chronic neuropathic pain refractory to medical management can be debilitating and can seriously affect one's quality of life. The interest of ablative surgery for the treatment or palliation of chronic neuropathic pain, cancer-related or chemotherapy-induced, has grown. Numerous regions along the nociceptive pathways have been prominent targets including the various nuclei of the thalamus. Traditional targets include the medial pulvinar, central median, and posterior complex thalamic nuclei. However, there has been little research regarding the role of the central lateral nucleus. In this paper, we aim to summarize the anatomy, pathophysiology, and patient experiences of the central lateral thalamotomy.

The Effect of EDS-FLU on Objective and Patient-Reported Subjective Outcomes for Patients with Chronic Rhinosinusitis with Nasal Polyps.

BACKGROUND: Exhalation delivery system with fluticasone (EDS-FLU) delivers medication high and deep in the nasal passages and has been shown to reduce nasal polyp (NP) grade, an objective measure of efficacy, and to yield clinically meaningful improvements on subjective measures of symptoms in patients with chronic rhinosinusitis with nasal polyps (CRSwNP). OBJECTIVES: To better characterize EDS-FLU treatment, we analyzed responder rates for four outcome measures used in the EDS-FLU pivotal trials, in the overall study population as well as in subgroups of patients with or without prior sinus surgery or prior use of a standard intranasal corticosteroid spray (INS). METHODS: Data were pooled from two randomized, 24-week (16-week, double-blind + 8-week, open-label), placebo-controlled studies (NAVIGATE I and II). Results for patients receiving EDS-FLU (186 µg [n = 161] or 372 µg [n = 160]) or EDS-placebo (n = 161) twice daily during the double-blind phase are described. Responder criteria included NP grade reduction (≥1-point), 22-item Sino-Nasal Outcome Test (SNOT-22) reduction (>12-points), Patient Global Impression of Change (PGIC) (much/very much improved), and congestion score improvement (>0.5-points). RESULTS: More patients in the EDS-FLU group responded to each of the four responder criteria compared with EDS-placebo. More patients receiving EDS-FLU responded to ≥ 1 criterion compared with EDS-placebo at week 4 (82.7% and 60.4%, respectively) and week 16 (95.7% and 80.3%, respectively). Patients responded similarly irrespective of prior sinus surgery or prior INS use. Patient-reported outcome measures showed earlier responses than NP scores. CONCLUSIONS: Meaningful improvements were seen across multiple response criteria with EDS-FLU, suggesting that the broad treatment effect of EDS-FLU includes objective reduction in polyp grade and improvements in several patient-reported outcomes. TRIAL REGISTRATION: ClinicalTrials.gov (NAVIGATE I: NCT01622569 and NAVIGATE II: NCT01624662).

Neurostimulation for treatment-resistant posttraumatic stress disorder: an update on neurocircuitry and therapeutic targets.

Posttraumatic stress disorder (PTSD) is a widespread and often devastating psychiatric condition. Core symptoms include intrusive and distressing thoughts, heightened reactivity, mood changes, cognitive impairments, and consequent avoidance of trauma-related stimuli. Symptoms of PTSD are often refractory to standard treatments, and neuromodulatory techniques have therefore drawn significant interest among the most treatment-resistant patients. Transcranial magnetic stimulation has demonstrated minimal efficacy, and deep brain stimulation trials are currently ongoing. PTSD is a disorder of neural circuitry; the current understanding includes involvement of the amygdala (basolateral and central nuclei), the prefrontal cortex (ventral medial and dorsolateral regions), and the hippocampus. Neuroimaging and optogenetic studies have improved the understanding of large-scale neural networks and the effects of microcircuitry manipulation, respectively. This review discusses the current PTSD literature and ongoing neurostimulation trials, and it highlights the current understanding of neuronal circuit dysfunction in PTSD. The authors emphasize the anatomical correlations of PTSD's hallmark symptoms, offer another potential deep brain stimulation target for PTSD, and note the need for continued research to identify useful biomarkers for the development of closed-loop therapies. Although there is hope that neuromodulation will become a viable treatment modality for PTSD, this concept remains theoretical, and further research should involve institutional review board-approved controlled prospective clinical studies.

Stereotactic Radiosurgery Hypophysectomy for Palliative Treatment of Refractory Cancer Pain: A Historical Review and Update.

Medically refractory pain in those with advanced cancer significantly reduces one's quality of life. Therefore, palliative interventions to mitigate cancer pain and reduce opioid requirements are necessary to reduce patient suffering and opioid-induced side effects. Hypophysectomy, a largely forgotten pain procedure with several technical variations, has been repeatedly studied in small series with encouraging results, though historically has been fraught with complications. As a result, the minimally invasive and more tolerable stereotactic radiosurgery (SRS) hypophysectomy has resurfaced as a possible treatment for cancer-related pain. While the mechanism of pain relief is not entirely understood, the hypothalamohypophyseal axis appears to play an essential role in pain perception and transmission and involves C fiber signal processing and downstream modulation of the brainstem and spinal cord via the hypothalamus. This review highlights the role of hypophysectomy in alleviating advanced cancer pain, both in hormonal and nonhormonal malignancy and the current mechanistic understanding of pain relief for the three primary hypophysectomy modalities used historically: surgical and chemical adenolysis, as well as the more recent, SRS hypophysectomy. Given the lack of high-quality evidence for stereotactic radiosurgery hypophysectomy, there is a need for further rigorous and prospective clinical studies despite its ideal and noninvasive approach.

Amikacin liposome inhalation suspension for chronic Pseudomonas aeruginosa infection in cystic fibrosis.

BACKGROUND: Shortcomings of inhaled antibiotic treatments for Pseudomonas aeruginosa infection in patients with cystic fibrosis (CF) include poor drug penetration, inactivation by sputum, poor efficiency due to protective biofilm, and short residence in the lung. METHODS: Eligible patients with forced expiratory volume in 1 s (FEV1) ≥25% of predicted value at screening and CF with chronic P. aeruginosa infection were randomly assigned to receive 3 treatment cycles (28 days on, 28 days off) of amikacin liposome inhalation suspension (ALIS, 590 mg QD) or tobramycin inhalation solution (TIS, 300 mg BID). The primary endpoint was noninferiority of ALIS vs TIS in change from baseline to day 168 in FEV1 (per-protocol population). Secondary endpoints included change in respiratory symptoms by Cystic Fibrosis Questionnaire-Revised (CFQ-R). RESULTS: The study was conducted February 2012 to September 2013. ALIS was noninferior to TIS (95% CI, -4.95 to 2.34) for relative change in FEV1 (L) from baseline. The mean increases in CFQ-R score from baseline on the Respiratory Symptoms scale suggested clinically meaningful improvement in both arms at the end of treatment in cycle 1 and in the ALIS arm at the end of treatment in cycles 2 and 3; however, the changes were not statistically significant between the 2 treatment arms. Treatment-emergent adverse events (TEAEs) were reported in most patients (ALIS, 84.5%; TIS, 78.8%). Serious TEAEs occurred in 17.6% and 19.9% of patients, respectively; most were hospitalisations for infective pulmonary exacerbation of CF. CONCLUSIONS: Cyclical dosing of once-daily ALIS was noninferior to cyclical twice-daily TIS in improving lung function. ClinicalTrials.gov Identifier: NCT01315678.

Randomized Trial of Liposomal Amikacin for Inhalation in Nontuberculous Mycobacterial Lung Disease.

RATIONALE: Lengthy, multidrug, toxic, and low-efficacy regimens limit management of pulmonary nontuberculous mycobacterial disease. OBJECTIVES: In this phase II study, we investigated the efficacy and safety of liposomal amikacin for inhalation (LAI) in treatment-refractory pulmonary nontuberculous mycobacterial (Mycobacterium avium complex [MAC] or Mycobacterium abscessus) disease. METHODS: During the double-blind phase, patients were randomly assigned to LAI (590 mg) or placebo once daily added to their multidrug regimen for 84 days. Both groups could receive open-label LAI for 84 additional days. The primary endpoint was change from baseline to Day 84 on a semiquantitative mycobacterial growth scale. Other endpoints included sputum conversion, 6-minute-walk distance, and adverse events. MEASUREMENTS AND MAIN RESULTS: The modified intention-to-treat population included 89 (LAI = 44; placebo = 45) patients. The average age of the sample was 59 years; 88% were female; 92% were white; and 80 and 59 patients completed study drug dosing during the double-blind and open-label phases, respectively. The primary endpoint was not achieved (P = 0.072); however, a greater proportion of the LAI group demonstrated at least one negative sputum culture (14 [32%] of 44 vs. 4 [9%] of 45; P = 0.006) and improvement in 6-minute-walk test (+20.6 m vs. -25.0 m; P = 0.017) at Day 84. A treatment effect was seen predominantly in patients without cystic fibrosis with MAC and was sustained 1 year after LAI. Most adverse events were respiratory, and in some patients it led to drug discontinuation. CONCLUSIONS: Although the primary endpoint was not reached, LAI added to a multidrug regimen produced improvements in sputum conversion and 6-minute-walk distance versus placebo with limited systemic toxicity in patients with refractory MAC lung disease. Further research in this area is needed. Clinical trial registered with www.clinicaltrials.gov (NCT01315236).

Immediate perception of a reward is distinct from the reward's long-term salience.

Reward perception guides all aspects of animal behavior. However, the relationship between the perceived value of a reward, the latent value of a reward, and the behavioral response remains unclear. Here we report that, given a choice between two sweet and chemically similar sugars-L- and D-arabinose-Drosophila melanogaster prefers D- over L- arabinose, but forms long-term memories of L-arabinose more reliably. Behavioral assays indicate that L-arabinose-generated memories require sugar receptor Gr43a, and calcium imaging and electrophysiological recordings indicate that L- and D-arabinose differentially activate Gr43a-expressing neurons. We posit that the immediate valence of a reward is not always predictive of the long-term reinforcement value of that reward, and that a subset of sugar-sensing neurons may generate distinct representations of similar sugars, allowing for rapid assessment of the salient features of various sugar rewards and generation of reward-specific behaviors. However, how sensory neurons communicate information about L-arabinose quality and concentration-features relevant for long-term memory-remains unknown.

Discovery of 4-(benzylaminomethylene)isoquinoline-1,3-(2H,4H)-diones and 4-[(pyridylmethyl)aminomethylene]isoquinoline-1,3-(2H,4H)-diones as potent and selective inhibitors of the cyclin-dependent kinase 4.

The series of 4-(benzylaminomethylene)isoquinoline-1,3-(2H,4H)-dione and 4-[(pyridylmethyl)aminomethylene]isoquinoline-1,3-(2H,4H)-dione derivatives reported here represents a novel class of potential antitumor agents, which potently and selectively inhibit CDK4 over CDK2 and CDK1. In the benzylamino headpiece, a 3-OH substituent is required on the phenyl ring for CDK4 inhibitory activity, which is further enhanced when an iodo, aryl, heteroaryl, t-butyl, or cyclopentyl substituent is introduced at the C-6 position of the isoquinoline-1,3-dione core. To circumvent the metabolic liability associated with the phenolic OH group on the 4-substituted 3-OH phenyl headpiece, we take two approaches: first, introduce a nitrogen o- or p- to the 3-OH group in the phenyl ring; second, replace the phenyl headpiece with N-substituted 2-pyridones. We present here the synthesis, SAR data, metabolic stability data, and a CDK4 mimic model that explains the binding, potency, and selectivity of our CDK4 selective inhibitors.

Synthesis, SAR study and biological evaluation of novel pyrazolo[1,5-a]pyrimidin-7-yl phenyl amides as anti-proliferative agents.

Checkpoint deficiency of malignant cells can be exploited in cancer drug discovery. Compounds that selectively kill checkpoint-deficient cells versus checkpoint-proficient cells can be utilized to preferentially target tumor cells, while sparing normal cells. The protein p21(Wafl/Cipl/Sdi1) (hereafter referred to as p21) inhibits progression of the cell cycle by inhibiting the activity of G1 kinases (cyclin D/cdk4 and cyclin E-cdk2) and the G2 kinase (cyclin B/cdkl) in response to DNA damage or abnormal DNA content. The expression of p21 is often low in human cancer cells due to frequent loss of the upstream activator, p53, and is associated with poor prognosis in some cancer patients. Using an isogenic pair of cell lines, HCT116 (p21+/+) and 80S14 (p21-/-), we have disclosed previously a novel series of pyrazolo[1,5-a]pyrimidines that preferentially kill the p21-deficient cells. We will present the synthesis, biological activities and SAR study of a series of pyrazolo[1,5-a]pyrimidines with an optimized phenyl amide moiety at the C-7 position. The mechanism of action of these compounds will also be discussed.

4-(Phenylaminomethylene)isoquinoline-1,3(2H,4H)-diones as potent and selective inhibitors of the cyclin-dependent kinase 4 (CDK4).

The cyclin-dependent kinases (CDKs), as complexes with their respective partners, the cyclins, are critical regulators of cell cycle progression. Because aberrant regulations of CDK4/cyclin D1 lead to uncontrolled cell proliferation, a hallmark of cancer, small-molecule inhibitors of CDK4/cyclin D1 are attractive as prospective antitumor agents. The series of 4-(phenylaminomethylene)isoquinoline-1,3(2H,4H)-dione derivatives reported here represents a novel class of potent inhibitors that selectively inhibit CDK4 over CDK2 and CDK1 activities. In the headpiece of the 4-(phenylaminomethylene)isoquinoline-1,3(2H,4H)-dione, a basic amine substituent is required on the aniline ring for the CDK4 inhibitory activity. The inhibitory activity is further enhanced when an aryl or heteroaryl substituent is introduced at the C-6 position of the isoquinoline-1,3(2H,4H)-dione core. We present here SAR data and a CDK4 mimic model that explains the binding, potency, and selectivity of our CDK4 selective inhibitors.

Pyrazolo[1,5-a]pyrimidin-7-yl phenyl amides as novel antiproliferative agents: exploration of core and headpiece structure-activity relationships.

A novel series of antiproliferative agents containing pyrazolo[1,5-a]pyrimidin-7-yl phenyl amides, selective for p21-deficient cells, were identified by high-throughput screening. Exploration of the SAR relationships in the headpiece, core, and tailpiece is described. Strict steric, positional, and electronic requirements were observed, with a clear preference for both core nitrogens, a thienoyl headpiece, and meta substituted tailpiece.

Validation of cyclin D1/CDK4 as an anticancer drug target in MCF-7 breast cancer cells: Effect of regulated overexpression of cyclin D1 and siRNA-mediated inhibition of endogenous cyclin D1 and CDK4 expression.

We have examined the role of cyclin D1 and cyclin-dependent kinase-4 (CDK4) in the cell cycle progression and proliferation of MCF-7 breast cancer cells. Forced expression of cyclin D1 using a tetracycline-regulated expression system, and suppression of endogenous cyclin D1 and CDK4 using small interfering RNA (siRNA) were used to validate this protein complex as a drug target in cancer drug discovery. Overexpression of cyclin D1 increased both phosphorylation of the retinoblastoma gene product (RB) and passage through the G1-S phase transition, resulting in increased proliferation of cells. When cyclin D1 expression was shut off, growth rates fell below those seen in control cell lines transfected with the vector, indicating an increased dependence on this protein for proliferation. Inhibition of endogenous cyclin D1 or CDK4 expression by RNA interference resulted in hypophosphorylation of RB and accumulation of cells in G1. These results support the prevailing view that pharmacological inhibition of cyclin D1/CDK4 complexes is a useful strategy to inhibit the growth of tumors. Furthermore, since MCF-7 cells appear to be dependent on this pathway for their continued proliferation, it is a suitable cell line to test novel cyclin D1/CDK4 inhibitors.

Parallel synthesis and biological evaluation of 5,6,7,8-tetrahydrobenzothieno[2,3-d]pyrimidin-4(3H)-one cytotoxic agents selective for p21-deficient cells.

A novel series of inhibitors of cancer cell proliferation, selective against p21 cell cycle checkpoint-disrupted cells vs. cells with intact p21 checkpoint, were identified by high-throughput screening. Optimization of both ends of the lead molecule to improve potency, using parallel synthesis and iterative design, is described. The 2-(1,4-dibenzodioxane)-substituted derivative 14 was identified as a highly selective and potent agent displaying an IC50 of 91 nM in the p21-deficient cell line.

Inhibition of tumor cell proliferation by thieno[2,3-d]pyrimidin-4(1H)-one-based analogs.

On the basis of a screening lead from an assay using a pair of p21 isogenic cell lines (p21-proficient cells and p21-deficient cells) to identify chemoselective agents, a series of novel thieno[2,3-d]pyrimidin-4(1H)-one-based analogs was prepared. Some analogs inhibited the growth of human colon tumor cells.

Irreversible inhibitors of the EGF receptor may circumvent acquired resistance to gefitinib.

Non-small cell lung cancers (NSCLCs) with activating mutations in the kinase domain of the epidermal growth factor receptor (EGFR) demonstrate dramatic, but transient, responses to the reversible tyrosine kinase inhibitors gefitinib (Iressa) and erlotinib (Tarceva). Some recurrent tumors have a common secondary mutation in the EGFR kinase domain, T790M, conferring drug resistance, but in other cases the mechanism underlying acquired resistance is unknown. In studying multiple sites of recurrent NSCLCs, we detected T790M in only a small percentage of tumor cells. To identify additional mechanisms of acquired resistance to gefitinib, we used NSCLC cells harboring an activating EGFR mutation to generate multiple resistant clones in vitro. These drug-resistant cells demonstrate continued dependence on EGFR and ERBB2 signaling for their viability and have not acquired secondary EGFR mutations. However, they display increased internalization of ligand-activated EGFR, consistent with altered receptor trafficking. Although gefitinib-resistant clones are cross-resistant to related anilinoquinazolines, they demonstrate sensitivity to a class of irreversible inhibitors of EGFR. These inhibitors also show effective inhibition of signaling by T790M-mutant EGFR and killing of NSCLC cells with the T790M mutation. Both mechanisms of gefitinib resistance are therefore circumvented by irreversible tyrosine kinase inhibitors. Our findings suggest that one of these, HKI-272, may prove highly effective in the treatment of EGFR-mutant NSCLCs, including tumors that have become resistant to gefitinib or erlotinib.

Pyrazolo[1,5-a]pyrimidin-7-yl phenyl amides as novel anti-proliferative agents: parallel synthesis for lead optimization of amide region.

A novel series of p21 chemoselective agents containing a pyrazolo[1,5-a]pyrimidin-7-yl phenyl amides were identified by high throughput screening. Optimization of the amide region by parallel synthesis and the iterative design toward understanding structure-activity relationship to improve potency are described. The isopropyl carbamate derivative 34 was identified as a highly chemoselective agent displaying a potency of 51 nM in the p21 deficient cell line.