Fully integrated silicon probes for high-density recording of neural activity.

Sensory, motor and cognitive operations involve the coordinated action of large neuronal populations across multiple brain regions in both superficial and deep structures. Existing extracellular probes record neural activity with excellent spatial and temporal (sub-millisecond) resolution, but from only a few dozen neurons per shank. Optical Ca2+ imaging offers more coverage but lacks the temporal resolution needed to distinguish individual spikes reliably and does not measure local field potentials. Until now, no technology compatible with use in unrestrained animals has combined high spatiotemporal resolution with large volume coverage. Here we design, fabricate and test a new silicon probe known as Neuropixels to meet this need. Each probe has 384 recording channels that can programmably address 960 complementary metal-oxide-semiconductor (CMOS) processing-compatible low-impedance TiN sites that tile a single 10-mm long, 70 × 20-µm cross-section shank. The 6 × 9-mm probe base is fabricated with the shank on a single chip. Voltage signals are filtered, amplified, multiplexed and digitized on the base, allowing the direct transmission of noise-free digital data from the probe. The combination of dense recording sites and high channel count yielded well-isolated spiking activity from hundreds of neurons per probe implanted in mice and rats. Using two probes, more than 700 well-isolated single neurons were recorded simultaneously from five brain structures in an awake mouse. The fully integrated functionality and small size of Neuropixels probes allowed large populations of neurons from several brain structures to be recorded in freely moving animals. This combination of high-performance electrode technology and scalable chip fabrication methods opens a path towards recording of brain-wide neural activity during behaviour.

Development and validation of the Physician's Global Assessment of Fingernail Psoriasis.

BACKGROUND: Several clinician-rated scoring systems are available to assess nail psoriasis severity, but only one has been partially validated. OBJECTIVE: To develop and validate the Physician's Global Assessment of Fingernail Psoriasis (PGA-F), a new clinician-rated severity scale. METHODS: A literature review, concept elicitation, pilot cognitive debriefing and clinical expert consultations informed the development of the PGA-F. A multistage mixed-methods analysis consisted of practising dermatologist cognitive interviews (n = 10) for instrument clarity, relevance and comprehensiveness. Inter-rater reliability (IRR) of ratings from dermatologists (n = 22) and clinical trial investigators (n = 8) was tested using many-facet Rasch analysis. Concurrent validity between the PGA-F and modified Nail Psoriasis Severity Index (mNAPSI) at screening and baseline was assessed along with the degree of discrimination. Intraclass correlation coefficient (ICC) for single raters at multiple assessments determined IRR. RESULTS: The PGA-F synthesizes severity ratings across multiple disease features that classify individuals into 1 of 5 levels (clear to severe). Cognitive interviews confirmed content validity: all (n = 10, 100%) participants who agreed clinical criteria were consistent with nail psoriasis; no mismatched severity levels; and training photographs were realistic representations. All PGA-F items were locally independent and targeted patients along the severity continuum with complementary precision (item fit statistics: < the 1.5 acceptability threshold; exact agreements among the dermatologists [44%] and trial investigators [61.5%] exceeded 40% of acceptability threshold). Clinician reliability exceeded the threshold of acceptability for dermatologists and clinical trial investigators: 0.85 and 0.73, respectively. There was adequate correlation (>0.30) between mNAPSI and PGA-F at baseline and Week 26 with significant discrimination of severity and monotonic increases in the mNAPSI for each level of categorical severity on the PGA-F. ICC results for each type of IRR indicate that clinicians were consistent in individual patient ratings. CONCLUSION: The PGA-F is a rapid, valid and reliable clinician-rated severity scale for use in clinical practice and research.

Long-term safety and efficacy of trifarotene 50 µg/g cream, a first-in-class RAR-γ selective topical retinoid, in patients with moderate facial and truncal acne.

BACKGROUND: Treatment for both facial and truncal acne has not sufficiently been studied. OBJECTIVES: To evaluate the long-term safety and efficacy of trifarotene in both facial and truncal acne. METHODS: In a multicentre, open-label, 52-week study, patients with moderate facial and truncal acne received trifarotene 50 µg/g cream (trifarotene). Assessments included local tolerability, safety, investigator and physician's global assessments (IGA, PGA) and quality of life (QOL). A validated QOL questionnaire was completed by the patient at Baseline, Week 12, 26 and 52/ET. RESULTS: Of 453 patients enrolled, 342 (75.5%) completed the study. Trifarotene-related treatment-emergent adverse events (TEAEs) were reported in 12.6% of patients, and none was serious. Most related TEAEs were cutaneous and occurred during the first 3 months. Signs and symptoms of local tolerability were mostly mild or moderate and severe signs, and symptoms were reported for 2.2% to 7.1% of patients for the face and 2.5% to 5.4% for the trunk. Local irritation increased during the first week of treatment on the face and up to Weeks 2 to 4 on the trunk with both decreasing thereafter. At Week 12, IGA and PGA success rates were 26.6% and 38.6%, respectively. Success rates increased to 65.1% and 66.9%, respectively at Week 52. Overall success (both IGA and PGA success in the same patient) was 57.9% at Week 52. At Week 52 visit, 92/171 (53.8%) patients who had completed their assessments had scores from 0 to 1 (i.e. no effect of acne on their QOL) vs. 47/208 (22.6%) patients at Baseline visit. CONCLUSION: In this 52-week study, trifarotene was safe, well tolerated and effective in moderate facial and truncal acne.

Efficacy and safety of mirikizumab (LY3074828) in the treatment of moderate-to-severe plaque psoriasis: results from a randomized phase II study.

BACKGROUND: Inhibiting interleukin (IL)-23 in patients with psoriasis has demonstrated high levels of skin clearance. OBJECTIVES: To investigate, in a phase II (AMAF; NCT02899988), multicentre, double-blind trial, the efficacy and safety of three doses of mirikizumab (LY3074828), a p19-directed IL-23 antibody, vs. placebo in patients with moderate-to-severe plaque psoriasis. METHODS: Adult patients were randomized 1 : 1 : 1 : 1 to receive placebo (n = 52), mirikizumab 30 mg (n = 51), mirikizumab 100 mg (n = 51) or mirikizumab 300 mg (n = 51) subcutaneously at weeks 0 and 8. The primary objective was to evaluate the superiority of mirikizumab over placebo in achieving a 90% improvement in the Psoriasis Area and Severity Index (PASI 90) response at week 16. Comparisons were done using logistic regression analysis with treatment, geographical region and previous biological therapy in the model. Missing data were imputed as nonresponses. RESULTS: Ninety-seven per cent of patients completed the first 16 weeks of the study. The primary end point was met for all mirikizumab dose groups vs. placebo, with PASI 90 response rates at week 16 of 0%, 29% (P = 0·009), 59% (P < 0·001) and 67% (P < 0·001) for patients receiving placebo, and mirikizumab 30 mg, 100 mg and 300 mg, respectively. There were two (1%) serious adverse events in mirikizumab-treated patients vs. one (2%) in a placebo-group patient. CONCLUSIONS: At week 16, 67% of patients treated with mirikizumab 300 mg at 8-week intervals achieved PASI 90. The percentage of patients reporting at least one treatment-emergent adverse event was similar among patients treated with placebo or mirikizumab.

Adalimumab for nail psoriasis: efficacy and safety over 52 weeks from a phase-3, randomized, placebo-controlled trial.

BACKGROUND: Few clinical trials have evaluated long-term treatment of nail psoriasis with biologics. OBJECTIVE: Safety and efficacy of adalimumab [ADA; Humira AbbVie Inc, North Chicago, IL, USA)] long-term treatment (52 weeks) was evaluated in a phase-3, randomized trial in patients with moderate-to-severe plaque psoriasis and concomitant moderate-to-severe fingernail psoriasis. Results from the first 26 weeks (Period A) have been reported. METHODS: Patients receiving 40 mg ADA every other week or placebo in Period A, continued with or switched to 40 mg ADA every-other-week treatment in the subsequent 26-week open-label extension (OLE) period. Main efficacy evaluations were ≥75% improvement in total-fingernail modified Nail Psoriasis Severity Index (mNAPSI 75) and achievement of Physician's Global Assessment for Fingernail Psoriasis of clear or minimal disease (PGA-F 0/1) with a ≥2-grade improvement from baseline, across the trial for patients who continued ADA from Period A through the OLE (Continuous-ADA Population). Safety was evaluated during the OLE and for patients receiving ADA at any time during the study (All-ADA Population). RESULTS: Of the 217 patients initially randomized in Period A, 188 (86.6%; 94 in each treatment group) entered the OLE after completion of or early escape from Period A. For the Continuous-ADA Population (N = 109), endpoint achievement rates improved from OLE entry (Week 26) to Week 52, including total-fingernail mNAPSI 75 (47.4-54.5%); PGA-F 0/1 (51.1-55.6%) and total-fingernail mNAPSI = 0 (6.6-17.9%). Serious adverse event and serious infection rates for the All-ADA Population (N = 203) were 6.9% and 3.4%, respectively. CONCLUSIONS: In this population of psoriasis patients with concomitant, moderate-to-severe nail psoriasis, long-term efficacy and improvement in signs and symptoms of nail disease were demonstrated after every-other-week ADA treatment, including incremental improvements in rate of total clearance of nail disease. No new safety risks were identified for patients receiving at least one ADA dose across 52 weeks.

Normal neuroanatomical variants that may be misinterpreted as disease entities.

Variations of normal development and benign incidental anomalies are frequently observed on diagnostic neuroimaging. It is important these are recognised for what they are, as misinterpretation may result in unnecessary further investigation, follow-up imaging and anxiety. In this article, we review benign intracranial anomalies commonly referred to our unit for specialist neuroradiology advice or multidisciplinary discussion, concerning cysts of the pineal gland and pituitary fossa, vascular anomalies, and perivascular spaces. This article outlines the embryology and development, the various imaging features as well as the clinical relevance and differential diagnoses of each normal neuroanatomical variant.

Ixekizumab treatment improves fingernail psoriasis in patients with moderate-to-severe psoriasis: results from the randomized, controlled and open-label phases of UNCOVER-3.

BACKGROUND: Fingernail psoriasis is difficult to treat. OBJECTIVE: The objective was to evaluate the effect of ixekizumab, a monoclonal antibody selectively targeting IL-17A, on fingernail psoriasis. METHODS: This Phase 3, double-blind trial (UNCOVER-3) randomized patients to placebo, etanercept (50-mg twice weekly), or 80 mg ixekizumab as one injection every 4 (IXE Q4W) or 2 weeks (IXE Q2W) after a 160-mg starting dose. At Week 12, ixekizumab patients received open-label IXE Q4W through Week 60; placebo patients received a 160-mg starting ixekizumab dose and etanercept patients a 4-week placebo washout before starting IXE Q4W. Efficacy was assessed by mean per cent Nail Psoriasis Severity Index (NAPSI) improvement at Weeks 12 and 60. RESULTS: Of 1346 patients in the UNCOVER-3 trial, this subgroup analysis included only patients with baseline fingernail psoriasis: 116 (60.1%) placebo, 236 (61.8%) etanercept, 228 (59.1%) IXE Q4W and 229 (59.5%) IXE Q2W. At Week 12, greater mean per cent NAPSI improvements were achieved in IXE Q4W (36.7%) and IXE Q2W (35.2%) vs. placebo (-34.3%, P < 0.001 each comparison) and etanercept (20.0%, P = 0.048 vs. Q4W, P = 0.072 vs. Q2W). At Week 60, mean per cent NAPSI improvement was >80% regardless of initial treatment. At Week 12 (nonresponder imputation), complete resolution (NAPSI = 0) was achieved in 19.7% (IXE Q4W), 17.5% (IXE Q2W), 4.3% (placebo, P < 0.001 each comparison) and 10.2% (etanercept, P < 0.05 each comparison) of patients. By Week 60, >50% of patients achieved complete resolution. CONCLUSIONS: At Week 12, significant improvements in fingernail psoriasis were achieved with ixekizumab therapy. With IXE Q4W maintenance dosing, additional improvement was demonstrated through 60 weeks, and >50% of patients achieved complete resolution. Registered at clinicaltrials.gov: NCT01646177.

Improvement of scalp and nail lesions with ixekizumab in a phase 2 trial in patients with chronic plaque psoriasis.

BACKGROUND: Scalp and nail psoriasis have a major impact on quality of life and are traditionally resistant to therapy. Ixekizumab is a monoclonal antibody that targets IL-17A, a key cytokine in psoriasis pathogenesis. OBJECTIVE: Changes in nail and scalp psoriasis associated with ixekizumab treatment were evaluated in a post hoc analysis of a phase 2 study comprising a 20-week randomized, placebo-controlled (RCT) period and 48 weeks of an open-label extension (OLE) period. METHODS: There were 142 patients with moderate-to-severe plaque psoriasis at baseline of the RCT. Patients were randomized to receive placebo, 10, 25, 75 or 150 mg of ixekizumab injected subcutaneously at weeks 0, 2, 4, 8, 12 and 16. In the OLE, all patients received 120 mg ixekizumab every 4 weeks. Nail Psoriasis Severity Index (NAPSI) and Psoriasis Scalp Severity Index (PSSI) were used to evaluate nail and scalp psoriasis respectively. Fifty-eight (41.0%) patients had nail psoriasis (NAPSI > 0) and 105 (74.0%) had scalp psoriasis (PSSI > 0) at baseline; these cases were evaluated for the present analyses. RESULTS: At RCT week 20, patients with scalp psoriasis in the 25-, 75- and 150-mg groups had significant mean change and percent improvement from baseline PSSI of -16.3 (75.3%; P = 0.001), -11.6 (83.7%; P = 0.001) and -18.2 (82.2%; P < 0.001) respectively compared to -6.0 (18.8%) in placebo. Patients with nail psoriasis in the 75- and 150-mg groups had significant improvements from baseline NAPSI of -26.3 (63.8%; P = 0.003) and -23.1 (52.6%; P = 0.009) respectively compared to 0.4 (-1.7%) in placebo. By OLE week 48, 78.0% of patients with scalp psoriasis and 51.0% of patients with nail psoriasis experienced complete resolution of lesions (PSSI = 0 or NAPSI = 0). CONCLUSIONS: Ixekizumab monotherapy improved scalp psoriasis quickly with maintenance of clinical response and complete resolution of plaques in the majority of patients. Additionally, over 50.0% of patients with nail psoriasis experienced complete resolution of nail lesions by OLE week 48.

Ustekinumab improves nail disease in patients with moderate-to-severe psoriasis: results from PHOENIX 1.

BACKGROUND: Most patients with psoriasis have nail changes, and treating nail psoriasis is challenging. OBJECTIVES: To assess improvement in fingernail psoriasis with ustekinumab treatment in the PHOENIX 1 trial. METHODS: Patients received ustekinumab 45 mg or 90 mg, or placebo at weeks 0 and 4. Ustekinumab-randomized patients continued maintenance dosing every 12 weeks, while patients receiving placebo crossed over to receive ustekinumab 45 mg or 90 mg at weeks 12/16 followed by dosing every 12 weeks. At week 40, initial responders [those with ≥ 75% improvement from baseline in Psoriasis Area and Severity Index (PASI 75)] were rerandomized either to continue maintenance dosing or to withdraw from treatment. Nail involvement was evaluated using the Nail Psoriasis Severity Index (NAPSI) on a target fingernail, Nail Physician's Global Assessment (Nail PGA) and mean number of nails involved. RESULTS: Of 766 randomized patients, 545 (71·1%) had nail psoriasis. At week 24, the percentage improvement from baseline NAPSI score was 46·5% (ustekinumab 45 mg) and 48·7% (ustekinumab 90 mg). Percentage improvements in NAPSI ranged from 29·7% (PASI < 50) to 57·3% (PASI ≥ 90). Mean NAPSI scores improved from 4·5 at baseline to 2·4 at week 24 (45 mg) and from 4·4 to 2·2 (90 mg). Nail PGA scores and the mean number of psoriatic nails improved by week 24. Further improvement was observed for all end points among initial responders continuing maintenance treatment through week 52. CONCLUSIONS: Ustekinumab significantly improves nail psoriasis, and improvements continue over time until up to 1 year of treatment in those receiving maintenance treatment.

Magnetic voluntary head-fixation in transgenic rats enables lifespan imaging of hippocampal neurons.

The precise neural mechanisms within the brain that contribute to the remarkable lifetime persistence of memory are not fully understood. Two-photon calcium imaging allows the activity of individual cells to be followed across long periods, but conventional approaches require head-fixation, which limits the type of behavior that can be studied. We present a magnetic voluntary head-fixation system that provides stable optical access to the brain during complex behavior. Compared to previous systems that used mechanical restraint, there are no moving parts and animals can engage and disengage entirely at will. This system is failsafe, easy for animals to use and reliable enough to allow long-term experiments to be routinely performed. Animals completed hundreds of trials per session of an odor discrimination task that required 2-4 s fixations. Together with a reflectance fluorescence collection scheme that increases two-photon signal and a transgenic Thy1-GCaMP6f rat line, we are able to reliably image the cellular activity in the hippocampus during behavior over long periods (median 6 months), allowing us track the same neurons over a large fraction of animals' lives (up to 19 months).

Inflammation and tissue remodeling mediator expression during gingivitis: A comparison between experimental, naturally occurring gingivitis, and periodontal health.

BACKGROUND: The aim of this study is to evaluate the immune regulation and tissue remodeling responses during experimental gingivitis (EG) and naturally occurring gingivitis (NG) to provide a comprehensive analysis of host responses. Gingival crevicular fluid (GCF) was obtained from 2 human studies conducted in university settings. METHODS: The EG study enrolling 26 volunteers provided controls for the baseline (Day 0) from healthy disease-free participants, while Day 21 (the end of EG induction of the same group) was used to represent EG. Twenty-six NG participants age-matched with those of the EG group were recruited. GCF samples were analyzed for 39 mediators of inflammatory/immune responses and tissue remodeling using commercially available bead-based multiplex immunoassays. The differences in GI and mediator expression among groups were determined at a 95% confidence level (p ≤ 0.05) by a 2-way analysis of variance (ANOVA) with a post-hoc Tukey's test. RESULTS: Our findings showed that EG had a greater gingival index than NG and was healthy (p < 0.01 of all comparisons). Furthermore, EG showed significantly higher levels of MPO (p < 0.001), CCL3 (p < 0.05), and IL-1B (p < 0.001) than NG. In contrast, NG had increased levels of MIF (p < 0.05), Fractalkine (p < 0.001), angiogenin (p < 0.05), C3a (p < 0.001), BMP-2 (p < 0.001), OPN (p < 0.05), RANKL (p < 0.001), and MMP-13 (p < 0.001) than EG. CONCLUSIONS: Consistent with the findings from chronic (NG) versus acute (EG) inflammatory lesions, these data reveal that NG displays greater immune regulation, angiogenesis, and bone remodeling compared to EG.

Secukinumab induction and maintenance therapy in moderate-to-severe plaque psoriasis: a randomized, double-blind, placebo-controlled, phase II regimen-finding study.

BACKGROUND: Interleukin (IL)-17A has major proinflammatory activity in psoriatic lesional skin. OBJECTIVES: To assess the efficacy and safety of secukinumab, a fully human IgG1κ monoclonal anti-IL-17A antibody, in moderate-to-severe plaque psoriasis in a phase II regimen-finding study. METHODS: A total of 404 patients were randomized to subcutaneous placebo (n = 67) or one of three secukinumab 150 mg induction regimens: single (week 0; n = 66), early (weeks 0, 1, 2, 4; n = 133) and monthly (weeks 0, 4, 8; n = 138 patients). The primary outcome was ≥ 75% improvement from baseline Psoriasis Area and Severity Index score (PASI 75) at week 12. PASI 75 responders from active treatment arms at week 12 were rerandomized to either a fixed-interval (secukinumab 150 mg at weeks 12 and 24; n = 65) or a treatment-at-start-of-relapse maintenance regimen (secukinumab 150 mg at visits at which a start of relapse was observed; n = 67). RESULTS: At week 12, early and monthly induction regimens resulted in higher PASI 75 response rates vs. placebo (54·5% and 42·0% vs. 1·5%; P < 0·001 for both). Among PASI 75 responders at week 12 entering the maintenance period, PASI 75 and PASI 90 achievement at least once from week 20 to week 28 was superior with the fixed-interval regimen [85% (n = 55) and 58% (n = 38), respectively] vs. the start-of-relapse regimen [67% (n = 45), P = 0·020, and 21% (n = 14), respectively]. Fifteen weeks after last study drug administration, < 10% of patients in the fixed-interval and start-of-relapse groups experienced a start of relapse. No immunogenicity was observed, and no injection-site reactions were reported. Reported cases of neutropenia were mild-to-moderate (≤ grade 2); none was associated with clinically significant adverse events or resulted in study discontinuation. Due to the brief duration of the safety assessment, no firm conclusions can be drawn regarding long-term safety. CONCLUSIONS: Secukinumab shows efficacy for induction and maintenance treatment of moderate-to-severe plaque psoriasis.

Acute subarachnoid haemorrhage: is a negative CT angiogram enough?

AIM: To determine the negative predictive value of 16 channel multisection computed tomography angiography (CTA) for detecting aneurysms in spontaneous subarachnoid haemorrhage (SAH), using digital subtraction angiography (DSA) as the reference standard. MATERIALS AND METHODS: The prospectively collected cerebral angiogram database of Department of Neuroradiology, Atkinson Morley Regional Neuroscience Centre was used to identify 200 consecutive patients who had undergone DSA for SAH. Of these, 176 had undergone CTA prior to DSA. Clinical details and radiology reports were correlated and images of positive investigations reviewed. RESULTS: DSA showed one or more cerebral aneurysms in 105 (60%) patients. These were correctly reported on CTA in 100. CTA was reported negative for aneurysms in 74 patients. Of these five were false negative and had aneurysms detected on DSA. In the CTA/DSA negative group, 11 (16%) patients had classical perimesencephalic clinical syndrome and blood distribution. There were two false positives at CTA. For ruptured cerebral aneurysms, CTA had 95.2% sensitivity, 97.2% specificity, 98.1% positive predictive value, and 93.2% negative predictive value. CONCLUSION: The sensitivity and negative predictive value of CTA for ruptured aneurysms remains imperfect. Continued use of DSA is recommended in most patients with a negative CTA after acute SAH. Confirmation of a negative CTA result with DSA may not be routinely required in patients with perimesencephalic syndrome.

Efficacy, safety and tolerability of topical terbinafine nail solution in patients with mild-to-moderate toenail onychomycosis: results from three randomized studies using double-blind vehicle-controlled and open-label active-controlled designs.

BACKGROUND: Terbinafine nail solution (TNS) was developed for the treatment of onychomycosis. OBJECTIVE: To assess the efficacy of TNS vs. vehicle and amorolfine 5% nail lacquer. METHODS: Subjects with mild-to-moderate toe onychomycosis (25% to ≤75% nail-involvement, matrix uninvolved) were randomized to receive either TNS or vehicle in two double-blind studies, and to TNS or amorolfine in an active-controlled, open-label study. Primary endpoint was complete cure (no residual clinical involvement and negative mycology) at week 52. Secondary endpoints were mycological cure (negative mycology defined as negative KOH microscopy and negative culture) and clinical effectiveness (≤10% residual-involvement and negative mycology) at week 52. RESULTS: Complete cure was not different between TNS vs. vehicle and amorolfine. Mycological cure was higher with TNS vs. vehicle, as was clinical effectiveness with TNS vs. vehicle, and TNS and amorolfine were not different for secondary efficacy endpoints. Patients achieving mycological cure had a better clinical outcome, and efficacy was improved in subjects with milder disease. Post hoc analysis suggests that nail thickness is an important prognostic factor. Moreover, mycological cure may require 6 months of treatment regimen while complete cure and clinical effectiveness may be achievable only after 10 months. A simulation study suggests that longer treatment duration would have resulted in higher complete cure with TNS vs. vehicle. Study treatments were well-tolerated. CONCLUSION: Primary efficacy objectives were not met in the studies reported herein. Possible reasons for failure to achieve significant outcomes include insufficient length of treatment; stringency of primary endpoint and severity of nail involvement of study population.

Hippocampal spatial representations exhibit a hyperbolic geometry that expands with experience.

Daily experience suggests that we perceive distances near us linearly. However, the actual geometry of spatial representation in the brain is unknown. Here we report that neurons in the CA1 region of rat hippocampus that mediate spatial perception represent space according to a non-linear hyperbolic geometry. This geometry uses an exponential scale and yields greater positional information than a linear scale. We found that the size of the representation matches the optimal predictions for the number of CA1 neurons. The representations also dynamically expanded proportional to the logarithm of time that the animal spent exploring the environment, in correspondence with the maximal mutual information that can be received. The dynamic changes tracked even small variations due to changes in the running speed of the animal. These results demonstrate how neural circuits achieve efficient representations using dynamic hyperbolic geometry.

An intra-cerebral drug delivery system for freely moving animals.

Microinfusions of drugs directly into the central nervous system of awake animals represent a widely used means of unravelling brain functions related to behaviour. However, current approaches generally use tethered liquid infusion systems and a syringe pump to deliver drugs into the brain, which often interfere with behaviour. We address this shortfall with a miniaturised electronically-controlled drug delivery system (20 × 17.5 × 5 mm³) designed to be skull-mounted in rats. The device features a micropump connected to two 8-mm-long silicon microprobes with a cross section of 250 × 250 µm² and integrated fluid microchannels. Using an external electronic control unit, the device allows infusion of 16 metered doses (0.25 µL each, 8 per silicon shaft). Each dosage requires 3.375 Ws of electrical power making the device additionally compatible with state-of-the-art wireless headstages. A dosage precision of 0.25 ± 0.01 µL was determined in vitro before in vivo tests were carried out in awake rats. No passive leakage from the loaded devices into the brain could be detected using methylene blue dye. Finally, the device was used to investigate the effects of the NMDA-receptor antagonist 3-((R)-2-Carboxypiperazin-4-yl)-propyl-1-phosphonic acid, (R)-CPP, administered directly into the prefrontal cortex of rats during performance on a task to assess visual attention and impulsivity. In agreement with previous findings using conventional tethered infusion systems, acute (R)-CPP administration produced a marked increase in impulsivity.

A randomized, placebo- and active-controlled, parallel-group, multicentre, investigator-blinded study of four treatment regimens of posaconazole in adults with toenail onychomycosis.

BACKGROUND: Onychomycosis accounts for up to 50% of all onychopathies. OBJECTIVES: To evaluate the efficacy of four posaconazole regimens compared with placebo in the treatment of toenail onychomycosis, to assess the safety and tolerability of posaconazole, and to estimate the relative efficacy of posaconazole against terbinafine. METHODS: A phase 2B, randomized, placebo- and active-controlled, parallel-group, multicentre, investigator-blinded (double blind for placebo) study (ClinicalTrials.gov identifier: NCT00491764). Onychomycosis patients aged 18-75years (n=218) were randomized equally to one of six treatment regimens: posaconazole (oral suspension) 100, 200 or 400mg once daily (24weeks); posaconazole 400 mg once daily (12weeks); terbinafine (tablets) 250mg once daily (12weeks); or placebo (24weeks). The primary efficacy variable was complete cure (negative mycology and 0% nail involvement) at week 48. RESULTS: All posaconazole treatment arms had a significantly (P≤0·012) greater proportion of patients with complete cure at week 48 compared with placebo. The proportions of patients with complete cure were numerically higher for posaconazole 200mg/24weeks (54·1%) and 400mg/24weeks (45·5%), but lower for 400mg/12weeks (20%) compared with terbinafine (37%; differences were not statistically significant). Posaconazole was well tolerated. Seven patients receiving posaconazole withdrew because of asymptomatic liver enzyme increases, as mandated by protocol discontinuation criteria. CONCLUSIONS: The efficacy and favourable safety profile of posaconazole suggest a potential new treatment for onychomycosis. The availability of low-cost generic terbinafine may limit posaconazole use to second-line treatment of infections refractory to, or patients intolerant of, terbinafine, or nondermatophyte mould infections.

Counseling in fetal medicine: agenesis of the corpus callosum.

In this Review, we aim to provide up-to-date and evidence-based answers to common questions regarding the diagnosis and prognosis of prenatally detected agenesis of the corpus callosum (ACC). A systematic literature search was performed to identify all reports of ACC and reference lists of articles were identified. ACC involves partial or complete absence of the main commissural pathway that connects the two cerebral hemispheres, and can be isolated (with no other abnormalities) or complex (coexisting with other abnormalities). It is a rare finding and the prevalence is difficult to estimate because of selection bias in reported series. The corpus callosum (CC) can be assessed on ultrasound by direct visualization, but indirect features, such as ventriculomegaly, absence of the cavum septi pellucidi or widening of interhemispheric fissure, are often the reason for detection in a screening population. Careful imaging in a center with a high level of expertise is required to make a full assessment and to exclude coexisting abnormalities, which occur in about 46% of fetuses. When available, magnetic resonance imaging appears to be an important adjunct as it allows direct visualization. It can reduce false-positive rates on ultrasound and can confirm ACC, it can assess whether this is complete or partial and it can help in detecting coexisting brain abnormalities not seen on ultrasound. The overall rate of chromosomal abnormality in fetuses with ACC is 18%, but this high rate includes both isolated and complex ACC; more recent studies suggest that chromosomal abnormalities are rare in isolated cases. Nevertheless, postnatal follow-up studies suggest that about 15% of cases thought to be isolated prenatally were found to have associated abnormalities after birth. Neurodevelopmental outcome in isolated ACC was recently reported in a systematic review and suggested normal outcome in about 65-75% of cases. Findings need to be considered in light of the several limitations of existing studies, in terms of study design, selection bias, varying definitions and imaging protocols, ascertainment bias and lack of control groups. These uncertainties mean that antenatal counseling is difficult and further large prospective studies are needed.

An extended role for CT in the emergency diagnosis of malignant spinal cord compression.

AIM: To evaluate the usefulness of computed tomography (CT) for triaging between urgent transfer to a neurosurgical unit and delayed magnetic resonance imaging (MRI) in the local hospital. MATERIALS AND METHODS: Radiologists blinded to the MRI findings scored CT images from 1-5 using a novel grading system based on the degree of cord compression observed in 44 patients. Seventy separate levels were scored. The observers' CT scores were compared with the MRI findings. All scoring radiologists were specialist registrars at different stages of training. RESULTS: Agreement between CT and MRI scores for metastatic spinal cord compression (MSCC) were high with Cohen's weighted Kappa score 0.70 (p<0.001, 95% CI 0.65 to 0.75). CT has a sensitivity of 89% and specificity of 92% for MSCC. Half the false-positive and false-negative results came from a single junior radiologist who would not normally report CT or MRI studies unsupervised. The best CT-MRI agreement was from the most senior trainee radiologist. CONCLUSIONS: Spinal findings on routine staging whole-body CT combined with clinical findings are sufficient to determine which patients with MSCC can safely wait for MRI the next working day at the local hospital and those who need emergency transfer to a neurosurgical unit for MRI and possible surgical decompression.