Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 271
Filter
1.
Nat Commun ; 15(1): 4154, 2024 May 16.
Article in English | MEDLINE | ID: mdl-38755205

ABSTRACT

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).


Subject(s)
Hippocampus , Neurons , Rats, Transgenic , Animals , Hippocampus/cytology , Neurons/metabolism , Rats , Male , Calcium/metabolism , Head/diagnostic imaging , Magnetics , Odorants/analysis , Female
2.
J Periodontol ; 2024 May 06.
Article in English | MEDLINE | ID: mdl-38708772

ABSTRACT

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.

3.
Nat Neurosci ; 26(1): 131-139, 2023 01.
Article in English | MEDLINE | ID: mdl-36581729

ABSTRACT

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.


Subject(s)
Brain , Hippocampus , Rats , Animals , Hippocampus/physiology , Space Perception/physiology , Neurons/physiology , CA1 Region, Hippocampal/physiology
5.
J Eur Acad Dermatol Venereol ; 35(11): 2324-2330, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34014011

ABSTRACT

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.


Subject(s)
Physicians , Psoriasis , Humans , Nails , Psoriasis/diagnosis , Reproducibility of Results , Severity of Illness Index
6.
J Eur Acad Dermatol Venereol ; 34(1): 166-173, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31306527

ABSTRACT

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.


Subject(s)
Acne Vulgaris/drug therapy , Dermatologic Agents/administration & dosage , Retinoids/administration & dosage , Administration, Cutaneous , Adolescent , Adult , Child , Dermatologic Agents/adverse effects , Drug Administration Schedule , Face , Female , Humans , Male , Middle Aged , Retinoids/adverse effects , Skin Cream , Torso , Treatment Outcome , Young Adult
7.
J Eur Acad Dermatol Venereol ; 33(11): 2168-2178, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31304993

ABSTRACT

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.


Subject(s)
Adalimumab/therapeutic use , Nail Diseases/drug therapy , Psoriasis/drug therapy , Adalimumab/adverse effects , Adult , Double-Blind Method , Female , Humans , Male , Middle Aged , Nail Diseases/complications , Psoriasis/complications , Severity of Illness Index , Time Factors , Treatment Outcome
8.
Br J Dermatol ; 181(1): 88-95, 2019 07.
Article in English | MEDLINE | ID: mdl-30734266

ABSTRACT

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.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Antibodies, Monoclonal, Humanized/administration & dosage , Psoriasis/drug therapy , Adult , Aged , Anti-Inflammatory Agents, Non-Steroidal/adverse effects , Antibodies, Monoclonal, Humanized/adverse effects , Dose-Response Relationship, Drug , Double-Blind Method , Drug Administration Schedule , Female , Humans , Injections, Subcutaneous , Interleukin-23 Subunit p19/antagonists & inhibitors , Interleukin-23 Subunit p19/immunology , Male , Middle Aged , Placebos/administration & dosage , Placebos/adverse effects , Psoriasis/diagnosis , Psoriasis/immunology , Severity of Illness Index , Treatment Outcome , Young Adult
9.
Ecol Evol ; 8(4): 2108-2121, 2018 02.
Article in English | MEDLINE | ID: mdl-29468029

ABSTRACT

We studied the temperature relations of wild and zoo Aldabra giant tortoises (Aldabrachelys gigantea) focusing on (1) the relationship between environmental temperature and tortoise activity patterns (n = 8 wild individuals) and (2) on tortoise body temperature fluctuations, including how their core and external body temperatures vary in relation to different environmental temperature ranges (seasons; n = 4 wild and n = 5 zoo individuals). In addition, we surveyed the literature to review the effect of body mass on core body temperature range in relation to environmental temperature in the Testudinidae. Diurnal activity of tortoises was bimodally distributed and influenced by environmental temperature and season. The mean air temperature at which activity is maximized was 27.9°C, with a range of 25.8-31.7°C. Furthermore, air temperature explained changes in the core body temperature better than did mass, and only during the coldest trial, did tortoises with higher mass show more stable temperatures. Our results, together with the overall Testudinidae overview, suggest that, once variation in environmental temperature has been taken into account, there is little effect of mass on the temperature stability of tortoises. Moreover, the presence of thermal inertia in an individual tortoise depends on the environmental temperatures, and we found no evidence for inertial homeothermy. Finally, patterns of core and external body temperatures in comparison with environmental temperatures suggest that Aldabra giant tortoises act as mixed conformer-regulators. Our study provides a baseline to manage the thermal environment of wild and rewilded populations of an important island ecosystem engineer species in an era of climate change.

10.
Nature ; 551(7679): 232-236, 2017 11 08.
Article in English | MEDLINE | ID: mdl-29120427

ABSTRACT

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.


Subject(s)
Electrodes , Neurons/physiology , Silicon/metabolism , Animals , Entorhinal Cortex/cytology , Entorhinal Cortex/physiology , Female , Male , Mice , Movement/physiology , Prefrontal Cortex/cytology , Prefrontal Cortex/physiology , Rats , Semiconductors , Wakefulness/physiology
11.
Clin Radiol ; 72(10): 810-825, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28747250

ABSTRACT

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.


Subject(s)
Brain/anatomy & histology , Brain/diagnostic imaging , Central Nervous System/anatomy & histology , Central Nervous System/diagnostic imaging , Cysts/diagnostic imaging , Vascular Malformations/diagnostic imaging , Diagnosis, Differential , Humans , Magnetic Resonance Imaging , Tomography, X-Ray Computed
12.
J Eur Acad Dermatol Venereol ; 31(3): 477-482, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27910156

ABSTRACT

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.


Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , Dermatologic Agents/therapeutic use , Psoriasis/drug therapy , Adolescent , Adult , Aged , Aged, 80 and over , Antibodies, Monoclonal, Humanized/administration & dosage , Dermatologic Agents/administration & dosage , Double-Blind Method , Etanercept/therapeutic use , Female , Fingers , Humans , Immunosuppressive Agents/therapeutic use , Male , Middle Aged , Nails , Severity of Illness Index , Time Factors , Young Adult
13.
J Eur Acad Dermatol Venereol ; 29(9): 1763-70, 2015 Sep.
Article in English | MEDLINE | ID: mdl-25693783

ABSTRACT

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.


Subject(s)
Antibodies, Monoclonal, Humanized/administration & dosage , Nail Diseases/drug therapy , Scalp Dermatoses/drug therapy , Disease Progression , Dose-Response Relationship, Drug , Double-Blind Method , Female , Follow-Up Studies , Humans , Injections, Subcutaneous , Male , Middle Aged , Nail Diseases/diagnosis , Psoriasis/diagnosis , Psoriasis/drug therapy , Scalp Dermatoses/diagnosis , Severity of Illness Index , Treatment Outcome
14.
J Infect ; 70(6): 668-75, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25444972

ABSTRACT

BACKGROUND: HIV-associated cryptococcal meningoencephalitis (CM) is a leading cause of adult meningitis in sub-Saharan Africa. Neuroradiological data is however limited to case reports and small case series from developed countries and/or immunocompetent patients. METHODS: Eighty seven patients aged ≥18 hospitalized with a first episode of CM had magnetic resonance (MRI) imaging during the first two weeks of admission. A subset of eleven patients had follow-up scans approximately one month from their initial MRI scan. All had prospectively-recorded detailed neurological and visual examinations. RESULTS: An abnormal finding on neurological examination was detected in 33 (39%) patients. 38 (48%) patients experienced some visual loss. Neuroradiological lesions presumed to be cryptococcosis-related, as defined by the presence of dilated Virchow Robin spaces, pseudocysts or cryptococcomas, enhancing nodules, hydrocephalus, meningitis, focal perilesional oedema and infarcts, were detected in 55 (63%) patients. MRI findings suggestive of a second diagnosis were found in 18 (21%) patients. Visual loss was associated with the presence of cryptococcal-related lesions (p = 0.02). Blindness was associated with raised intracranial pressure (ICP) (p = 0.02). Of eleven patients with paired scans, brain swelling was identified on the initial scan in only one patient. CONCLUSION: The majority of patients had MRI brain scan abnormalities presumed secondary to CM. Dilated Virchow Robin spaces were the commonest neuroradiological lesion. Visual loss was associated with the degree of cerebral involvement as reflected by the presence of MRI abnormalities. Blindness was associated with the presence of raised ICP. Initial generalised brain swelling does not appear to be common, but further studies with paired scans are needed.


Subject(s)
AIDS-Related Opportunistic Infections/diagnostic imaging , Cryptococcus/isolation & purification , Magnetic Resonance Imaging/methods , Meningitis, Cryptococcal/diagnostic imaging , Meningoencephalitis/diagnostic imaging , Adult , Brain/diagnostic imaging , Female , Humans , Male , Middle Aged , Young Adult
15.
PLoS One ; 9(10): e111300, 2014.
Article in English | MEDLINE | ID: mdl-25333512

ABSTRACT

Actions expressed prematurely without regard for their consequences are considered impulsive. Such behaviour is governed by a network of brain regions including the prefrontal cortex (PFC) and nucleus accumbens (NAcb) and is prevalent in disorders including attention deficit hyperactivity disorder (ADHD) and drug addiction. However, little is known of the relationship between neural activity in these regions and specific forms of impulsive behaviour. In the present study we investigated local field potential (LFP) oscillations in distinct sub-regions of the PFC and NAcb on a 5-choice serial reaction time task (5-CSRTT), which measures sustained, spatially-divided visual attention and action restraint. The main findings show that power in gamma frequency (50-60 Hz) LFP oscillations transiently increases in the PFC and NAcb during both the anticipation of a cue signalling the spatial location of a nose-poke response and again following correct responses. Gamma oscillations were coupled to low-frequency delta oscillations in both regions; this coupling strengthened specifically when an error response was made. Theta (7-9 Hz) LFP power in the PFC and NAcb increased during the waiting period and was also related to response outcome. Additionally, both gamma and theta power were significantly affected by upcoming premature responses as rats waited for the visual cue to respond. In a subgroup of rats showing persistently high levels of impulsivity we found that impulsivity was associated with increased error signals following a nose-poke response, as well as reduced signals of previous trial outcome during the waiting period. Collectively, these in-vivo neurophysiological findings further implicate the PFC and NAcb in anticipatory impulsive responses and provide evidence that abnormalities in the encoding of rewarding outcomes may underlie trait-like impulsive behaviour.


Subject(s)
Attention Deficit Disorder with Hyperactivity/physiopathology , Choice Behavior/physiology , Impulsive Behavior/physiology , Prefrontal Cortex/physiology , Animals , Humans , Male , Motor Activity/physiology , Nucleus Accumbens/physiology , Rats , Reaction Time , Reward
16.
Science ; 345(6198): 814-7, 2014 Aug 15.
Article in English | MEDLINE | ID: mdl-25124440

ABSTRACT

The rules governing the formation of spatial maps in the hippocampus have not been determined. We investigated the large-scale structure of place field activity by recording hippocampal neurons in rats exploring a previously unencountered 48-meter-long track. Single-cell and population activities were well described by a two-parameter stochastic model. Individual neurons had their own characteristic propensity for forming fields randomly along the track, with some cells expressing many fields and many exhibiting few or none. Because of the particular distribution of propensities across cells, the number of neurons with fields scaled logarithmically with track length over a wide, ethological range. These features constrain hippocampal memory mechanisms, may allow efficient encoding of environments and experiences of vastly different extents and durations, and could reflect general principles of population coding.


Subject(s)
CA1 Region, Hippocampal/physiology , Pyramidal Cells/physiology , Space Perception , Action Potentials , Animals , Brain Mapping , CA1 Region, Hippocampal/cytology , Electrodes, Implanted , Exploratory Behavior , Male , Maze Learning , Memory/physiology , Orientation , Poisson Distribution , Rats , Rats, Long-Evans
17.
Biomed Tech (Berl) ; 59(4): 291-303, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24101367

ABSTRACT

Intracortical microprobes allow the precise monitoring of electrical and chemical signaling and are widely used in neuroscience. Microelectromechanical system (MEMS) technologies have greatly enhanced the integration of multifunctional probes by facilitating the combination of multiple recording electrodes and drug delivery channels in a single probe. Depending on the neuroscientific application, various assembly strategies are required in addition to the microprobe fabrication itself. This paper summarizes recent advances in the fabrication and assembly of micromachined silicon probes for drug delivery achieved within the EU-funded research project NeuroProbes. The described fabrication process combines a two-wafer silicon bonding process with deep reactive ion etching, wafer grinding, and thin film patterning and offers a maximum in design flexibility. By applying this process, three general comb-like microprobe designs featuring up to four 8-mm-long shafts, cross sections from 150×200 to 250×250 µm², and different electrode and fluidic channel configurations are realized. Furthermore, we discuss the development and application of different probe assemblies for acute, semichronic, and chronic applications, including comb and array assemblies, floating microprobe arrays, as well as the complete drug delivery system NeuroMedicator for small animal research.


Subject(s)
Brain/physiology , Electrodes, Implanted , Infusion Pumps, Implantable , Micro-Electrical-Mechanical Systems/instrumentation , Microelectrodes , Microinjections/instrumentation , Animals , Brain/surgery , Equipment Design , Humans , Miniaturization , Systems Integration
18.
Br J Dermatol ; 170(2): 398-407, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24117389

ABSTRACT

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.


Subject(s)
Antibodies, Monoclonal, Humanized/administration & dosage , Dermatologic Agents/administration & dosage , Nail Diseases/drug therapy , Psoriasis/drug therapy , Cross-Over Studies , Double-Blind Method , Female , Humans , Male , Middle Aged , Severity of Illness Index , Treatment Outcome , Ustekinumab
19.
BMJ Case Rep ; 20132013 Apr 22.
Article in English | MEDLINE | ID: mdl-23608841

ABSTRACT

Mucosa-associated lymphoid tissue (MALT) cells are present in gastrointestinal mucosa but rarely found in the central nervous system (CNS). We describe an unusual and rare case of CNS MALT lymphoma in a patient presenting with stroke-like symptoms.


Subject(s)
Brain Neoplasms/diagnosis , Lymphoma, B-Cell, Marginal Zone/diagnosis , Biopsy , Brain Neoplasms/pathology , Brain Neoplasms/radiotherapy , Contrast Media , Diagnosis, Differential , Humans , Lymphoma, B-Cell, Marginal Zone/pathology , Lymphoma, B-Cell, Marginal Zone/radiotherapy , Magnetic Resonance Imaging , Male , Middle Aged
20.
Br J Dermatol ; 168(2): 402-11, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23362969

ABSTRACT

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.


Subject(s)
Antibodies, Monoclonal/administration & dosage , Dermatologic Agents/administration & dosage , Psoriasis/drug therapy , Antibodies, Monoclonal/adverse effects , Antibodies, Monoclonal, Humanized , Body Weight , Dermatologic Agents/adverse effects , Dose-Response Relationship, Drug , Double-Blind Method , Female , Humans , Induction Chemotherapy/methods , Injections, Intradermal , Maintenance Chemotherapy/adverse effects , Maintenance Chemotherapy/methods , Male , Middle Aged , Severity of Illness Index , Treatment Outcome
SELECTION OF CITATIONS
SEARCH DETAIL
...