228 research outputs found
Performance deficits of NK1 receptor knockout mice in the 5 choice serial reaction time task: effects of d Amphetamine, stress and time of day.
Background
The neurochemical status and hyperactivity of mice lacking functional substance P-preferring NK1 receptors (NK1R-/-) resemble abnormalities in Attention Deficit Hyperactivity Disorder (ADHD). Here we tested whether NK1R-/- mice express other core features of ADHD (impulsivity and inattentiveness) and, if so, whether they are diminished by d-amphetamine, as in ADHD. Prompted by evidence that circadian rhythms are disrupted in ADHD, we also compared the performance of mice that were trained and tested in the morning or afternoon.
Methods and Results
The 5-Choice Serial Reaction-Time Task (5-CSRTT) was used to evaluate the cognitive performance of NK1R-/- mice and their wildtypes. After training, animals were tested using a long (LITI) and a variable (VITI) inter-trial interval: these tests were carried out with, and without, d-amphetamine pretreatment (0.3 or 1 mg/kg i.p.). NK1R-/- mice expressed greater omissions (inattentiveness), perseveration and premature responses (impulsivity) in the 5-CSRTT. In NK1R-/- mice, perseveration in the LITI was increased by injection-stress but reduced by d-amphetamine. Omissions by NK1R-/- mice in the VITI were unaffected by d-amphetamine, but premature responses were exacerbated by this psychostimulant. Omissions in the VITI were higher, overall, in the morning than the afternoon but, in the LITI, premature responses of NK1R-/- mice were higher in the afternoon than the morning.
Conclusion
In addition to locomotor hyperactivity, NK1R-/- mice express inattentiveness, perseveration and impulsivity in the 5-CSRTT, thereby matching core criteria for a model of ADHD. Because d-amphetamine reduced perseveration in NK1R-/- mice, this action does not require functional NK1R. However, the lack of any improvement of omissions and premature responses in NK1R-/- mice given d-amphetamine suggests that beneficial effects of this psychostimulant in other rodent models, and ADHD patients, need functional NK1R. Finally, our results reveal experimental variables (stimulus parameters, stress and time of day) that could influence translational studies
Regional Chemotherapy in Locally Advanced Pancreatic Cancer: RECLAP Trial
<p>Abstract</p> <p>Background</p> <p>Pancreatic cancer is the fourth leading cause of cancer death in the United States. Surgery offers the only chance for cure. However, less than twenty percent of patients are considered operative candidates at the time of diagnosis. A common reason for being classified as unresectable is advanced loco-regional disease.</p> <p>A review of the literature indicates that almost nine hundred patients with pancreatic cancer have received regional chemotherapy in the last 15 years. Phase I studies have shown regional administration of chemotherapy to be safe. The average reported response rate was approximately 26%. The average 1-year survival was 39%, with an average median survival of 9 months. Of the patients that experienced a radiographic response to therapy, 78 (78/277, 28%) patients underwent exploratory surgery following regional chemotherapy administration; thirty-two (41%) of those patients were amenable to pancreatectomy. None of the studies performed analyses to identify factors predicting response to regional chemotherapy.</p> <p>Progressive surgical techniques combined with current neoadjuvant chemoradiotherapy strategies have already yielded emerging support for a multimodality approach to treatment of advanced pancreatic cancer.</p> <p>Intravenous gemcitabine is the current standard treatment of pancreatic cancer. However, >90% of the drug is secreted unchanged affecting toxicity but not the cancer per se. Gemcitabine is converted inside the cell into its active drug form in a rate limiting reaction. We hypothesize that neoadjuvant regional chemotherapy with continuous infusion of gemcitabine will be well tolerated and may improve resectability rates in cases of locally advanced pancreatic cancer.</p> <p>Design</p> <p>This is a phase I study designed to evaluate the feasibility and toxicity of super-selective intra-arterial administration of gemcitabine in patients with locally advanced, unresectable pancreatic adenocarcinoma. Patients considered unresectable due to locally advanced pancreatic cancer will receive super-selective arterial infusion of gemcitabine over 24 hours via subcutaneous indwelling port. Three to six patients will be enrolled per dose cohort, with seven cohorts, plus an additional six patients at the maximum tolerated dose; accrual is expected to last 36 months. Secondary objectives will include the determination of progression free and overall survival, as well as the conversion rate from unresectable to potentially resectable pancreatic cancer.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov ID: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01294358">NCT01294358</a></p
Chemical diplomacy in male tilapia: urinary signal increases sex hormone and decreases aggression
Androgens, namely 11-ketotestosterone (11KT), have a central role in male fish reproductive physiology and are thought to be involved in both aggression and social signalling. Aggressive encounters occur frequently in social species, and fights may cause energy depletion, injury and loss of social status. Signalling for social dominance and fighting ability in an agonistic context can minimize these costs. Here, we test the hypothesis of a 'chemical diplomacy' mechanism through urinary signals that avoids aggression and evokes an androgen response in receiver males of Mozambique tilapia (Oreochromis mossambicus). We show a decoupling between aggression and the androgen response; males fighting their mirror image experience an unresolved interaction and a severe drop in urinary 11KT. However, if concurrently exposed to dominant male urine, aggression drops but urinary 11KT levels remain high. Furthermore, 11KT increases in males exposed to dominant male urine in the absence of a visual stimulus. The use of a urinary signal to lower aggression may be an adaptive mechanism to resolve disputes and avoid the costs of fighting. As dominance is linked to nest building and mating with females, the 11KT response of subordinate males suggests chemical eavesdropping, possibly in preparation for parasitic fertilizations.info:eu-repo/semantics/publishedVersio
Evaluation of two formulations of adjuvanted RTS, S malaria vaccine in children aged 3 to 5 years living in a malaria-endemic region of Mozambique: a Phase I/IIb randomized double-blind bridging trial
BACKGROUND: Previous trials of the RTS, S malaria candidate vaccine have shown that this vaccine is safe, tolerated and immunogenic. The development plan for this vaccine aims at administering it in the first year of life through the Expanded Program on Immunization (EPI). The objective was to evaluate the safety and reactogenicity of RTS, S/AS02D (0.5 ml dose), a pediatric formulation of GlaxoSmithKline Biologicals' current malaria candidate vaccine RTS, S/AS02A (0.25 ml dose). A 0.5 ml dose of AS02D is composed of the same active ingredients in the same quantities as in a 0.25 ml dose of AS02A and has been developed to be easily introduced into routine EPI practices. METHODS: We performed a phase I/IIb randomized double-blind bridging study in a malaria-endemic region of Mozambique, to compare the safety and immunogenicity of both candidate vaccines with the aim of replacing RTS, S/AS02A with RTS, S/AS02D as the candidate pediatric vaccine. 200 Mozambican children aged 3 to 5 years were randomized 1:1 to receive one of the 2 vaccines according to a 0, 1, 2 month schedule. RESULTS: Both vaccines were safe and had similar reactogenicity profiles. All subjects with paired pre and post-vaccination samples showed a vaccine response with respect to anti-circumsporozoite (CS) antibodies irrespective of initial anti-CS serostatus. Geometric mean titers (GMTs) were 191 EU/ml (95% CI 150β242) in recipients of RTS, S/AS02D compared to 180 EU/ml (95% CI 146β221) in recipients of RTS, S/AS02A. For the anti-hepatitis B surface antigen (HBsAg), all subjects were seroprotected at day 90, and the GMTs were 23978 mIU/ml (95% CI 17896β32127) in RTS, S/AS02D recipients and 17410 mIU/ml (95% CI 13322β22752) in RTS, S/AS02A recipients. There was a decrease in anti-CS GMTs between months 3 and 14 in both groups (191 vs 22 EU/mL in RTS, S/AS02D group and 180 vs 29 EU/mL in RTS, S/AS02A group). CONCLUSION: Our data show that the RTS, S/AS02D is safe, well tolerated, and demonstrates non-inferiority (defined as upper limit of the 95% confidence interval of the anti-CS GMT ratio of RTS, S/AS02A to RTS, S/AS02D below 3.0) of the antibody responses to circumsporozoite and HBsAg induced by the RTS, S/AS02D as compared to the RTS, S/AS02A
Increased Immune Complexes of Hypocretin Autoantibodies in Narcolepsy
International audienceBACKGROUND: Hypocretin peptides participate in the regulation of sleep-wake cycle while deficiency in hypocretin signaling and loss of hypocretin neurons are causative for narcolepsy-cataplexy. However, the mechanism responsible for alteration of the hypocretin system in narcolepsy-cataplexy and its relevance to other central hypersomnias remain unknown. Here we studied whether central hypersomnias can be associated with autoantibodies reacting with hypocretin-1 peptide present as immune complexes. METHODOLOGY: Serum levels of free and dissociated (total) autoantibodies reacting with hypocretin-1 peptide were measured by enzyme-linked immunosorbent assay and analyzed with regard to clinical parameters in 82 subjects with narcolepsy-cataplexy, narcolepsy without cataplexy or idiopathic hypersomnia and were compared to 25 healthy controls. PRINCIPAL FINDINGS: Serum levels of total but not free IgG autoantibodies against hypocretin-1 were increased in narcolepsy-cataplexy. Increased levels of complexed IgG autoantibodies against hypocretin-1 were found in all patients groups with a further increase in narcolepsy-cataplexy. Levels of total IgM hypocretin-1 autoantibodies were also elevated in all groups of patients. Increased levels of anti-idiotypic IgM autoantibodies reacting with hypocretin-1 IgG autoantibodies affinity purified from sera of subjects with narcolepsy-cataplexy were found in all three groups of patients. Disease duration correlated negatively with serum levels of hypocretin-1 IgG and IgM autoantibodies and with anti-idiotypic IgM autoantibodies. CONCLUSION: Central hypersomnias and particularly narcolepsy-cataplexy are characterized by higher serum levels of autoantibodies directed against hypocretin-1 which are present as immune complexes most likely with anti-idiotypic autoantibodies suggesting their relevance to the mechanism of sleep-wake cycle regulation
The African Cichlid Fish Astatotilapia burtoni Uses Acoustic Communication for Reproduction: Sound Production, Hearing, and Behavioral Significance
Sexual reproduction in all animals depends on effective communication between signalers and receivers. Many fish species, especially the African cichlids, are well known for their bright coloration and the importance of visual signaling during courtship and mate choice, but little is known about what role acoustic communication plays during mating and how it contributes to sexual selection in this phenotypically diverse group of vertebrates. Here we examined acoustic communication during reproduction in the social cichlid fish, Astatotilapia burtoni. We characterized the sounds and associated behaviors produced by dominant males during courtship, tested for differences in hearing ability associated with female reproductive state and male social status, and then tested the hypothesis that female mate preference is influenced by male sound production. We show that dominant males produce intentional courtship sounds in close proximity to females, and that sounds are spectrally similar to their hearing abilities. Females were 2β5-fold more sensitive to low frequency sounds in the spectral range of male courtship sounds when they were sexually-receptive compared to during the mouthbrooding parental phase. Hearing thresholds were also negatively correlated with circulating sex-steroid levels in females but positively correlated in males, suggesting a potential role for steroids in reproductive-state auditory plasticity. Behavioral experiments showed that receptive females preferred to affiliate with males that were associated with playback of courtship sounds compared to noise controls, indicating that acoustic information is likely important for female mate choice. These data show for the first time in a Tanganyikan cichlid that acoustic communication is important during reproduction as part of a multimodal signaling repertoire, and that perception of auditory information changes depending on the animal's internal physiological state. Our results highlight the importance of examining non-visual sensory modalities as potential substrates for sexual selection contributing to the incredible phenotypic diversity of African cichlid fishes
Assessment of aortic stiffness by cardiovascular magnetic resonance following the treatment of severe aortic stenosis by TAVI and surgical AVR
Aortic stiffness is increasingly used as an independent predictor of adverse cardiovascular outcomes. We sought to compare the impact of transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) upon aortic vascular function using cardiovascular magnetic resonance (CMR) measurements of aortic distensibility and pulse wave velocity (PWV).A 1.5Β T CMR scan was performed pre-operatively and at 6Β m post-intervention in 72 patients (32 TAVI, 40 SAVR; age 76βΒ±β8Β years) with high-risk symptomatic severe aortic stenosis. Distensibility of the ascending and descending thoracic aorta and aortic pulse wave velocity were determined at both time points. TAVI and SAVR patients were comparable for gender, blood pressure and left ventricular ejection fraction. The TAVI group were older (81βΒ±β6.3 vs. 72.8βΒ±β7.0Β years, pβ<β0.05) with a higher EuroSCORE II (5.7βΒ±β5.6 vs. 1.5βΒ±β1.0Β %, pβ<β0.05). At 6Β m, SAVR was associated with a significant decrease in distensibility of the ascending aorta (1.95βΒ±β1.15 vs. 1.57βΒ±β0.68βΓβ10(-3)mmHg(-1), pβ=β0.044) and of the descending thoracic aorta (3.05βΒ±β1.12 vs. 2.66βΒ±β1.00βΓβ10(-3)mmHg(-1), pβ=β0.018), with a significant increase in PWV (6.38βΒ±β4.47 vs. 11.01βΒ±β5.75Β ms(-1), pβ=β0.001). Following TAVI, there was no change in distensibility of the ascending aorta (1.96βΒ±β1.51 vs. 1.72βΒ±β0.78βΓβ10(-3)mmHg(-1), pβ=β0.380), descending thoracic aorta (2.69βΒ±β1.79 vs. 2.21βΒ±β0.79βΓβ10(-3)mmHg(-1), pβ=β0.181) nor in PWV (8.69βΒ±β6.76 vs. 10.23βΒ±β7.88Β ms(-1), pβ=β0.301) at 6Β m.Treatment of symptomatic severe aortic stenosis by SAVR but not TAVI was associated with an increase in aortic stiffness at 6Β months. Future work should focus on the prognostic implication of these findings to determine whether improved patient selection and outcomes can be achieved
The Aguablanca Niβ(Cu) sulfide deposit, SW Spain: geologic and geochemical controls and the relationship with a midcrustal layered mafic complex
The Aguablanca Niβ(Cu) sulfide deposit is
hosted by a breccia pipe within a gabbroβdiorite pluton.
The deposit probably formed due to the disruption of a
partially crystallized layered mafic complex at about 12β
19 km depth and the subsequent emplacement of melts and
breccias at shallow levels (<2 km). The ore-hosting breccias
are interpreted as fragments of an ultramafic cumulate,
which were transported to the near surface along with a
molten sulfide melt. Phlogopite ArβAr ages are 341β
332 Ma in the breccia pipe, and 338β334 Ma in the layered
mafic complex, and are similar to recently reported UβPb
ages of the host Aguablanca Stock and other nearby calcalkaline
metaluminous intrusions (ca. 350β330 Ma). Ore
deposition resulted from the combination of two critical
factors, the emplacement of a layered mafic complex deep
in the continental crust and the development of small
dilational structures along transcrustal strike-slip faults that
triggered the forceful intrusion of magmas to shallow
levels. The emplacement of basaltic magmas in the lower
middle crust was accompanied by major interaction with
the host rocks, immiscibility of a sulfide melt, and the
formation of a magma chamber with ultramafic cumulates
and sulfide melt at the bottom and a vertically zoned mafic
to intermediate magmas above. Dismembered bodies of
mafic/ultramafic rocks thought to be parts of the complex
crop out about 50 km southwest of the deposit in a
tectonically uplifted block (Cortegana Igneous Complex,
Aracena Massif). Reactivation of Variscan structures that
merged at the depth of the mafic complex led to sequential
extraction of melts, cumulates, and sulfide magma. Lithogeochemistry
and Sr and Nd isotope data of the Aguablanca
Stock reflect the mixing from two distinct reservoirs, i.e.,
an evolved siliciclastic middle-upper continental crust and a
primitive tholeiitic melt. Crustal contamination in the deep
magma chamber was so intense that orthopyroxene
replaced olivine as the main mineral phase controlling the early fractional crystallization of the melt. Geochemical
evidence includes enrichment in SiO2 and incompatible
elements, and Sr and Nd isotope compositions (87Sr/86Sri
0.708β0.710; 143Nd/144Ndi 0.512β0.513). However, rocks
of the Cortegana Igneous Complex have low initial
87Sr/86Sr and high initial 143Nd/144Nd values suggesting
contamination by lower crustal rocks. Comparison of the
geochemical and geological features of igneous rocks in the
Aguablanca deposit and the Cortegana Igneous Complex
indicates that, although probably part of the same magmatic
system, they are rather different and the rocks of the
Cortegana Igneous Complex were not the direct source of
the Aguablanca deposit. Crustβmagma interaction was a
complex process, and the generation of orebodies was
controlled by local but highly variable factors. The model
for the formation of the Aguablanca deposit presented in
this study implies that dense sulfide melts can effectively
travel long distances through the continental crust and that
dilational zones within compressional belts can effectively
focus such melt transport into shallow environments
Integrin Clustering Is Driven by Mechanical Resistance from the Glycocalyx and the Substrate
Integrins have emerged as key sensory molecules that translate chemical and physical cues from the extracellular matrix (ECM) into biochemical signals that regulate cell behavior. Integrins function by clustering into adhesion plaques, but the molecular mechanisms that drive integrin clustering in response to interaction with the ECM remain unclear. To explore how deformations in the cell-ECM interface influence integrin clustering, we developed a spatial-temporal simulation that integrates the micro-mechanics of the cell, glycocalyx, and ECM with a simple chemical model of integrin activation and ligand interaction. Due to mechanical coupling, we find that integrin-ligand interactions are highly cooperative, and this cooperativity is sufficient to drive integrin clustering even in the absence of cytoskeletal crosslinking or homotypic integrin-integrin interactions. The glycocalyx largely mediates this cooperativity and hence may be a key regulator of integrin function. Remarkably, integrin clustering in the model is naturally responsive to the chemical and physical properties of the ECM, including ligand density, matrix rigidity, and the chemical affinity of ligand for receptor. Consistent with experimental observations, we find that integrin clustering is robust on rigid substrates with high ligand density, but is impaired on substrates that are highly compliant or have low ligand density. We thus demonstrate how integrins themselves could function as sensory molecules that begin sensing matrix properties even before large multi-molecular adhesion complexes are assembled
Blood Stage Malaria Vaccine Eliciting High Antigen-Specific Antibody Concentrations Confers No Protection to Young Children in Western Kenya
The antigen, falciparum malaria protein 1 (FMP1), represents the 42-kDa C-terminal fragment of merozoite surface protein-1 (MSP-1) of the 3D7 clone of P. falciparum. Formulated with AS02 (a proprietary Adjuvant System), it constitutes the FMP1/AS02 candidate malaria vaccine. We evaluated this vaccine's safety, immunogenicity, and efficacy in African children.A randomised, double-blind, Phase IIb, comparator-controlled trial.The trial was conducted in 13 field stations of one mile radii within Kombewa Division, Nyanza Province, Western Kenya, an area of holoendemic transmission of P. falciparum. We enrolled 400 children aged 12-47 months in general good health.Children were randomised in a 1ratio1 fashion to receive either FMP1/AS02 (50 microg) or Rabipur(R) rabies vaccine. Vaccinations were administered on a 0, 1, and 2 month schedule. The primary study endpoint was time to first clinical episode of P. falciparum malaria (temperature >/=37.5 degrees C with asexual parasitaemia of >/=50,000 parasites/microL of blood) occurring between 14 days and six months after a third dose. Case detection was both active and passive. Safety and immunogenicity were evaluated for eight months after first immunisations; vaccine efficacy (VE) was measured over a six-month period following third vaccinations.374 of 400 children received all three doses and completed six months of follow-up. FMP1/AS02 had a good safety profile and was well-tolerated but more reactogenic than the comparator. Geometric mean anti-MSP-1(42) antibody concentrations increased from1.3 microg/mL to 27.3 microg/mL in the FMP1/AS02 recipients, but were unchanged in controls. 97 children in the FMP1/AS02 group and 98 controls had a primary endpoint episode. Overall VE was 5.1% (95% CI: -26% to +28%; p-value = 0.7).FMP1/AS02 is not a promising candidate for further development as a monovalent malaria vaccine. Future MSP-1(42) vaccine development should focus on other formulations and antigen constructs.Clinicaltrials.gov NCT00223990
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