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1.
Cereb Cortex ; 33(8): 4202-4215, 2023 04 04.
Article in English | MEDLINE | ID: mdl-36068947

ABSTRACT

The pulvinar is a heterogeneous thalamic nucleus, which is well developed in primates. One of its subdivisions, the medial pulvinar, is connected to many cortical areas, including the visual, auditory, and somatosensory cortices, as well as with multisensory areas and premotor areas. However, except for the visual modality, little is known about its sensory functions. A hypothesis is that, as a region of convergence of information from different sensory modalities, the medial pulvinar plays a role in multisensory integration. To test this hypothesis, 2 macaque monkeys were trained to a fixation task and the responses of single-units to visual, auditory, and auditory-visual stimuli were examined. Analysis revealed auditory, visual, and multisensory neurons in the medial pulvinar. It also revealed multisensory integration in this structure, mainly suppressive (the audiovisual response is less than the strongest unisensory response) and subadditive (the audiovisual response is less than the sum of the auditory and the visual responses). These findings suggest that the medial pulvinar is involved in multisensory integration.


Subject(s)
Pulvinar , Animals , Macaca , Haplorhini , Neurons/physiology , Sensation , Auditory Perception/physiology , Acoustic Stimulation , Photic Stimulation , Visual Perception/physiology
2.
Am J Med Genet A ; 188(12): 3525-3530, 2022 12.
Article in English | MEDLINE | ID: mdl-35972041

ABSTRACT

Basaloid follicular hamartomas (BFH) are benign small basaloid skin tumors that can present as solitary or multiple lesions. Congenital BFH lesions arranged in a segmental distribution have been described, suggesting they derive from a somatic post-zygotic mutational event. Previously, BFH were described in Happle-Tinschert syndrome, which results from a post-zygotic SMO variant and is characterized by segmental BFH with variable involvement of the teeth, skeleton, and central nervous system. Here, we describe two patients with isolated segmental BFH and no systemic involvement. Paired whole exome sequencing of BFH and normal tissue revealed a pathogenic SMO c.1234 C>T, p.L412F variant restricted to BFH tissue. We characterized the proliferation index and expression of Hedgehog and Wnt/beta-catenin pathway related proteins in segmental BFH compared to sporadic basal cell carcinomas (BCCs) and found that segmental BFH had a lower proliferation index. Although segmental BFH expressed a similar level of Gli-1 compared to BCCs, levels of LEF-1 and SOX-9 expression in BFH were weaker for both and patchier for LEF-1. Our results show that a somatic SMO activating variant causes segmental BFH. Since these patients are prone to developing BCCs, differences in SOX9, LEF1, and Ki-67 expression can help distinguish between these two basaloid lesions.


Subject(s)
Carcinoma, Basal Cell , Hamartoma , Skin Diseases , Skin Neoplasms , Humans , Hair Follicle/abnormalities , Hair Follicle/metabolism , Hair Follicle/pathology , Hedgehog Proteins/genetics , Hedgehog Proteins/metabolism , Carcinoma, Basal Cell/diagnosis , Carcinoma, Basal Cell/genetics , Carcinoma, Basal Cell/metabolism , Hamartoma/diagnosis , Hamartoma/genetics , Hamartoma/metabolism , Skin Diseases/pathology , Skin Neoplasms/diagnosis , Skin Neoplasms/genetics , Skin Neoplasms/metabolism , Smoothened Receptor/genetics
3.
Microsyst Nanoeng ; 8: 21, 2022.
Article in English | MEDLINE | ID: mdl-35251687

ABSTRACT

Flexible intracerebral probes for neural recording and electrical stimulation have been the focus of many research works to achieve better compliance with the surrounding tissue while minimizing rejection. Strategies have been explored to find the best way to insert flexible probes into the brain while maintaining their flexibility once positioned. Here, we present a novel and versatile scalable batch fabrication approach to deliver ultrathin and flexible probes consisting of a silk-parylene bilayer. The biodegradable silk layer, whose degradation time is programmable, provides a temporary and programmable stiffener to allow the insertion of ultrathin parylene-based flexible devices. Our innovative and robust batch fabrication technology allows complete freedom over probe design in terms of materials, size, shape, and thickness. We demonstrate successful ex vivo insertion of the probe with acute high-fidelity recordings of epileptic seizures in field potentials as well as single-unit action potentials in mouse brain slices. Our novel technological solution for implanting ultraflexible devices in the brain while minimizing rejection risks shows high potential for use in both brain research and clinical therapies.

4.
J Neurochem ; 160(3): 305-324, 2022 02.
Article in English | MEDLINE | ID: mdl-34905223

ABSTRACT

Extracellular adenosine plays prominent roles in the brain in both physiological and pathological conditions. Adenosine can be generated following the degradation of extracellular nucleotides by various types of ectonucleotidases. Several ectonucleotidases are present in the brain parenchyma: ecto-nucleotide triphosphate diphosphohydrolases 1 and 3 (NTPDase 1 and 3), ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (NPP 1), ecto-5'-nucleotidase (eN), and tissue non-specific alkaline phosphatase (TNAP, whose function in the brain has received little attention). Here we examined, in a living brain preparation, the role of these ectonucleotidases in generating extracellular adenosine. We recorded local field potentials evoked by electrical stimulation of the lateral olfactory tract in the mouse piriform cortex in vitro. Variations in adenosine level were evaluated by measuring changes in presynaptic inhibition generated by adenosine A1 receptors (A1Rs) activation. A1R-mediated presynaptic inhibition was present endogenously and was enhanced by bath-applied AMP and ATP. We hypothesized that inhibiting ectonucleotidases would reduce extracellular adenosine concentration, which would result in a weakening of presynaptic inhibition. However, inhibiting TNAP had no effect in controlling endogenous adenosine action and no effect on presynaptic inhibition induced by bath-applied AMP. Furthermore, contrary to our expectation, inhibiting TNAP reinforced, rather than reduced, presynaptic inhibition induced by bath-applied ATP. Similarly, inhibition of NTPDase 1 and 3, NPP1, and eN induced stronger, rather than weaker, presynaptic inhibition, both in endogenous condition and with bath-applied ATP and AMP. Consequently, attempts to suppress the functions of extracellular adenosine by blocking its extracellular synthesis in living brain tissue could have functional impacts opposite to those anticipated.


Subject(s)
Cerebral Cortex/drug effects , Enzyme Inhibitors/pharmacology , Nucleotidases/antagonists & inhibitors , Synaptic Transmission/drug effects , 5'-Nucleotidase/antagonists & inhibitors , Adenosine/metabolism , Adenosine A1 Receptor Agonists/pharmacology , Adenosine Monophosphate/pharmacology , Adenosine Triphosphate/pharmacology , Alkaline Phosphatase/antagonists & inhibitors , Animals , Electric Stimulation , Evoked Potentials/drug effects , Female , Mice , Mice, Inbred C57BL , Olfactory Bulb/drug effects , Receptor, Adenosine A1/drug effects , Receptor, Adenosine A1/metabolism
5.
Front Bioeng Biotechnol ; 9: 780197, 2021.
Article in English | MEDLINE | ID: mdl-34900968

ABSTRACT

In this study, we report a flexible implantable 4-channel microelectrode probe coated with highly porous and robust nanocomposite of poly (3,4-ethylenedioxythiophene) (PEDOT) and carbon nanofiber (CNF) as a solid doping template for high-performance in vivo neuronal recording and stimulation. A simple yet well-controlled deposition strategy was developed via in situ electrochemical polymerization technique to create a porous network of PEDOT and CNFs on a flexible 4-channel gold microelectrode probe. Different morphological and electrochemical characterizations showed that they exhibit remarkable and superior electrochemical properties, yielding microelectrodes combining high surface area, low impedance (16.8 ± 2 MΩ µm2 at 1 kHz) and elevated charge injection capabilities (7.6 ± 1.3 mC/cm2) that exceed those of pure and composite PEDOT layers. In addition, the PEDOT-CNF composite electrode exhibited extended biphasic charge cycle endurance and excellent performance under accelerated lifetime testing, resulting in a negligible physical delamination and/or degradation for long periods of electrical stimulation. In vitro testing on mouse brain slices showed that they can record spontaneous oscillatory field potentials as well as single-unit action potentials and allow to safely deliver electrical stimulation for evoking field potentials. The combined superior electrical properties, durability and 3D microstructure topology of the PEDOT-CNF composite electrodes demonstrate outstanding potential for developing future neural surface interfacing applications.

6.
Heliyon ; 7(12): e08581, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34917829

ABSTRACT

Due to the increasing demand resulting from the use of REE in many fields of human life, a weathering profile developed on granites in the semi-arid region of Biou area (North-Cameroon) has been characterized for rare-earth elements (REE) exploration. The mineralogical compositions of weathered materials were revealed by X-ray diffraction (XRD). X-ray Fluorescence (XRF) and Inductively Coupled Plasmas-Mass Spectrometry (ICP-MS) have been used to determine the geochemical composition of granites and the overlying weathered materials. The S-type and peraluminous granites are constituted by quartz, orthoclase, microcline, plagioclase, biotite, muscovite, pyroxene and opaque minerals. Accessory minerals are probably responsible for the interesting contents in REE + Y and some trace elements (e.g., Zr, Zn, Ba, Rb). The weathering profile show from the bottom to the top: (i) saprolitic horizons; (ii) lower loose clayey horizon; (iii) iron duricrust horizon; (iv) upper loose clayey horizon; (v) and organo-mineral horizon. Some weathered rock fragments remain in the loose clayey and organo-mineral horizons. The mineralogical composition of the weathering materials is dominated by illite, muscovite and feldspar. The low weathering degree of the materials is justified by the climatic and reducing conditions. The large ion lithophiles and ferromagnesian elements (Mg, Fe, V, Cu, Co, Cs Cr, Ni, Sc and Li) which are supposed to be mobile are so much accumulated in the weathering materials. REE show very low degree of fractionation in weathering profile due probably to the lack of good drainage. The whole weathering materials shows high REE + Y contents as its parent rock. Geochemical mass balance and enrichment factor reveal that REE, especially light REE, are so much enriched in the iron duricrust horizon (ion-adsorption REE deposit type). Some heavy REE are also enriched in the lower loose clayey horizon. This first survey has revealed that the weathering materials developed on granites in Biou area are favorable for further REE exploration.

7.
Pediatr Dermatol ; 38 Suppl 2: 79-85, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34272764

ABSTRACT

BACKGROUND: Patients of color are disproportionately impacted by vitiligo. Access to treatment depends greatly on insurance coverage. We, therefore, assessed current vitiligo treatment coverage policies across major United States health insurers to determine current patterns and coverage gaps for vitiligo. METHODS: The study surveyed 15 commercial health care insurers, 50 BlueCross BlueShield (BCBS) plans, Medicare, Medicaid, and Veterans Affairs. Information on treatment coverage for vitiligo, specifically pimecrolimus and tacrolimus, excimer laser therapy, PUVA, and narrow-band (nb)UVB, was collected via an online review of insurance policy documents, confirmed with phone calls to organization representatives, or via a survey of Medicaid providers, and state Medicaid directors. RESULTS: Of 17 organizations with regional or national coverage policies, 12% did not cover topical calcineurin inhibitors, 56% did not cover nbUVB phototherapy, 53% did not cover PUVA phototherapy, and 41% did not cover laser therapy. For BCBS, pimecrolimus and tacrolimus were not covered in 39% and 35% of states, respectively. NbUVB and PUVA therapy were not covered in 20% and 10% of states, respectively. Excimer laser therapy was not covered in 82% of states. Out of 32 states with accessible Medicaid information, 11 did not cover topicals, 5 did not cover nbUVB, 4 did not cover PUVA, and 7 did not cover laser. Two commonly cited reasons for coverage denial were that the treatment indication was considered cosmetic, and certain therapies are not FDA-approved. CONCLUSIONS: There is inequity in the distribution of health among vitiligo patients given current patterns of insurance coverage for treatment, which may have disproportionate impact on patients of color.


Subject(s)
Vitiligo , Aged , Child , Delivery of Health Care , Humans , Insurance Coverage , Medicare , PUVA Therapy , United States , Vitiligo/therapy
8.
Science ; 369(6507): 1110-1113, 2020 08 28.
Article in English | MEDLINE | ID: mdl-32855337

ABSTRACT

The origin of Earth's water remains unknown. Enstatite chondrite (EC) meteorites have similar isotopic composition to terrestrial rocks and thus may be representative of the material that formed Earth. ECs are presumed to be devoid of water because they formed in the inner Solar System. Earth's water is therefore generally attributed to the late addition of a small fraction of hydrated materials, such as carbonaceous chondrite meteorites, which originated in the outer Solar System where water was more abundant. We show that EC meteorites contain sufficient hydrogen to have delivered to Earth at least three times the mass of water in its oceans. EC hydrogen and nitrogen isotopic compositions match those of Earth's mantle, so EC-like asteroids might have contributed these volatile elements to Earth's crust and mantle.

9.
J Neurosci Methods ; 341: 108759, 2020 07 15.
Article in English | MEDLINE | ID: mdl-32389603

ABSTRACT

BACKGROUND: Recordings with tetrodes have proven to be more effective in isolating single neuron spiking activity than with single microwires. However, tetrodes have never been used in humans. We report on the characteristics, safety, compatibility with clinical intracranial recordings in epileptic patients, and performance, of a new type of hybrid electrode equipped with tetrodes. NEW METHOD: 240 standard clinical macroelectrodes and 102 hybrid electrodes were implanted in 28 patients. Hybrids (diameter 800 µm) are made of 6 or 9 macro-contacts and 2 or 3 tetrodes (diameter 70-80 µm). RESULTS: No clinical complication or adverse event was associated with the hybrids. Impedance and noise of recordings were stable over time. The design enabled multiscale spatial analyses that revealed physiopathological events which were sometimes specific to one tetrode, but could not be recorded on the macro-contacts. After spike sorting, the single-unit yield was similar to other hybrid electrodes and was sometimes as high as >10 neurons per tetrode. COMPARISON WITH EXISTING METHOD(S): This new hybrid electrode has a smaller diameter than other available hybrid electrodes. It provides novel spatial information due to the configuration of the tetrodes. The single-unit yield appears promising. CONCLUSIONS: This new hybrid electrode is safe, easy to use, and works satisfactorily for conducting multi-scale seizure and physiological analyses.


Subject(s)
Epilepsy , Neurons , Action Potentials , Electrodes , Electrodes, Implanted , Humans , Seizures
10.
Physiol Rep ; 7(3): e13992, 2019 02.
Article in English | MEDLINE | ID: mdl-30740934

ABSTRACT

We examined the effect of adenosine and of adenosine A1 receptor blockage on short-term synaptic plasticity in slices of adult mouse anterior piriform cortex maintained in vitro in an in vivo-like ACSF. Extracellular recording of postsynaptic responses was performed in layer 1a while repeated electrical stimulation (5-pulse-trains, frequency between 3.125 and 100 Hz) was applied to the lateral olfactory tract. Our stimulation protocol was aimed at covering the frequency range of oscillatory activities observed in the olfactory bulb in vivo. In control condition, postsynaptic response amplitude showed a large enhancement for stimulation frequencies in the beta and gamma frequency range. A phenomenological model of short-term synaptic plasticity fitted to the data suggests that this frequency-dependent enhancement can be explained by the interplay between a short-term facilitation mechanism and two short-term depression mechanisms, with fast and slow recovery time constants. In the presence of adenosine, response amplitude evoked by low-frequency stimulation decreased in a dose-dependent manner (IC50  = 70 µmol/L). Yet short-term plasticity became more dominated by facilitation and less influenced by depression. Both changes compensated for the initial decrease in response amplitude in a way that depended on stimulation frequency: compensation was strongest at high frequency, up to restoring response amplitudes to values similar to those measured in control condition. The model suggested that the main effects of adenosine were to decrease neurotransmitter release probability and to attenuate short-term depression mechanisms. Overall, these results suggest that adenosine does not merely inhibit neuronal activity but acts in a more subtle, frequency-dependent manner.


Subject(s)
Adenosine A1 Receptor Agonists/pharmacology , Adenosine/pharmacology , Neuronal Plasticity/drug effects , Piriform Cortex/drug effects , Receptor, Adenosine A1/drug effects , Synaptic Transmission/drug effects , Animals , Electric Stimulation , Female , In Vitro Techniques , Mice, Inbred C57BL , Models, Neurological , Piriform Cortex/physiology , Receptor, Adenosine A1/metabolism , Time Factors
11.
Clin Neurophysiol ; 130(4): 537-547, 2019 04.
Article in English | MEDLINE | ID: mdl-30785010

ABSTRACT

OBJECTIVE: The mechanisms underlying epileptogenicity in tuberous sclerosis complex (TSC) are poorly understood. METHODS: We analysed neuronal spiking activity (84 neurons), fast ripples (FRs), local field potentials and intracranial electroencephalogram during interictal epileptiform discharges (IEDs) in the tuber and perituber of a patient using novel hybrid electrodes equipped with tetrodes. RESULTS: IEDs were recorded in the tuber and perituber. FRs were recorded only in the tuber and only with the microelectrodes. A larger proportion of neurons in the tuber (57%) than in the perituber (17%) had firing-rates modulated around IEDs. CONCLUSIONS: A multi-scale analysis of neuronal activity, FRs and IEDs indicates a gradient of epileptogenicity running from the tuber to the perituber. SIGNIFICANCE: We demonstrate, for the first time in vivo, a gradient of epileptogenicity from the tuber to the perituber, which paves the way for future models of epilepsy in TSC. Our results also question the extent of the neurosurgical resection, including or not the perituber, that needs to be made in these patients.


Subject(s)
Action Potentials , Epilepsy/physiopathology , Tuberous Sclerosis/physiopathology , Adult , Cerebral Cortex/cytology , Cerebral Cortex/physiopathology , Cortical Excitability , Epilepsy/etiology , Female , Humans , Neurons/physiology , Tuberous Sclerosis/complications
12.
Appl Physiol Nutr Metab ; 43(5): 445-452, 2018 May.
Article in English | MEDLINE | ID: mdl-29200312

ABSTRACT

This study assessed blood levels of cortisol and cytokines (inflammatory and non-inflammatory) in members of the regular Canadian Armed Forces (CAF), and examined the associations between sex, age, and adiposity and circulating levels of cortisol as well as pro- and anti-inflammatory cytokines. As part of a larger ranging project, 331 blood samples were collected from a representative population of the total CAF, which included officers and noncommissioned women and men from the Air Force, Navy, and Army. The blood samples were analyzed for levels of cortisol, C-reactive protein (CRP), adiponectin, and 20 cytokines (which included interleukins, interferons, and tumor necrosis factors). Higher levels of adiponectin were found in women compared with men (median and interquartile range; 16.71 (7.68-25.32) vs 5.81 (3.52-13.19) µg/mL), and higher levels of interleukin (IL)-18 in men compared with women (89.25 (84.03-94.48) vs 75.91 (69.70-82.13) pg/mL). An association between age and levels of stress and inflammatory cytokines was observed, with CRP, IL-18, IL-2 and adiponectin all increasing with increasing age. However, contrary to trends seen in the general population, cortisol levels decreased with increasing age. Levels of CRP and IL-18 increased with an increase in adiposity, while adiponectin levels decreased. Most importantly, at the entire cohort level, a low detection rate for most of the cytokines was observed with 17 out of 22 cytokines having a detection below 10%. IN CONCLUSION: In this CAF population, although an association between age and inflammatory cytokines was observed, both sex and adiposity had a small impact on levels of cortisol and cytokines.


Subject(s)
Age Factors , Anthropometry , Cytokines/blood , Hydrocortisone/blood , Sex Factors , Absorptiometry, Photon , Adiponectin/blood , Adiposity , Adult , Body Composition , Body Mass Index , C-Reactive Protein/metabolism , Canada , Cohort Studies , Female , Humans , Limit of Detection , Male , Middle Aged , Military Personnel , Stress, Physiological , Surveys and Questionnaires , Young Adult
13.
PLoS One ; 12(8): e0183246, 2017.
Article in English | MEDLINE | ID: mdl-28820903

ABSTRACT

Neuronal activity is characterized by a diversity of oscillatory phenomena that are associated with multiple behavioral and cognitive processes, yet the functional consequences of these oscillations are not fully understood. Our aim was to determine whether and how these different oscillatory activities affect short-term synaptic plasticity (STP), using the olfactory system as a model. In response to odorant stimuli, the olfactory bulb displays a slow breathing rhythm as well as beta and gamma oscillations. Since the firing of olfactory bulb projecting neurons is phase-locked with beta and gamma oscillations, structures downstream from the olfactory bulb should be driven preferentially at these frequencies. We examined STP exhibited by olfactory bulb inputs in slices of adult mouse piriform cortex maintained in vitro in an in vivo-like ACSF (calcium concentration: 1.1 mM). We replaced the presynaptic neuronal firing rate by repeated electrical stimulation (frequency between 3.125 and 100 Hz) applied to the lateral olfactory tract. Our results revealed a considerable enhancement of postsynaptic response amplitude for stimulation frequencies in the beta and gamma range. A phenomenological model of STP fitted to the data suggests that the experimental results can be explained by the interplay between three mechanisms: a short-term facilitation mechanism (time constant ≈160 msec), and two short-term depression mechanisms (recovery time constants <20 msec and ≈140 msec). Increasing calcium concentration (2.2 mM) resulted in an increase in the time constant of facilitation and in a strengthening of the slowest depression mechanism. As a result, response enhancement was reduced and its peak shifted toward the low beta and alpha ranges while depression became predominant in the gamma band. Using environmental conditions corresponding to those that prevail in vivo, our study shows that STP in the lateral olfactory tract to layer Ia synapse allows amplification of olfactory bulb inputs at beta and gamma frequencies.


Subject(s)
Calcium/metabolism , Piriform Cortex/physiology , Animals , Electroencephalography , Mice , Neuronal Plasticity , Piriform Cortex/metabolism
14.
J Neurochem ; 140(6): 919-940, 2017 03.
Article in English | MEDLINE | ID: mdl-28072448

ABSTRACT

Tissue non-specific alkaline phosphatase (TNAP) is a key player of bone mineralization and TNAP gene (ALPL) mutations in human are responsible for hypophosphatasia (HPP), a rare heritable disease affecting the mineralization of bones and teeth. Moreover, TNAP is also expressed by brain cells and the severe forms of HPP are associated with neurological disorders, including epilepsy and brain morphological anomalies. However, TNAP's role in the nervous system remains poorly understood. To investigate its neuronal functions, we aimed to identify without any a priori the metabolites regulated by TNAP in the nervous tissue. For this purpose we used 1 H- and 31 P NMR to analyze the brain metabolome of Alpl (Akp2) mice null for TNAP function, a well-described model of infantile HPP. Among 39 metabolites identified in brain extracts of 1-week-old animals, eight displayed significantly different concentration in Akp2-/- compared to Akp2+/+ and Akp2+/- mice: cystathionine, adenosine, GABA, methionine, histidine, 3-methylhistidine, N-acetylaspartate (NAA), and N-acetyl-aspartyl-glutamate, with cystathionine and adenosine levels displaying the strongest alteration. These metabolites identify several biochemical processes that directly or indirectly involve TNAP function, in particular through the regulation of ecto-nucleotide levels and of pyridoxal phosphate-dependent enzymes. Some of these metabolites are involved in neurotransmission (GABA, adenosine), in myelin synthesis (NAA, NAAG), and in the methionine cycle and transsulfuration pathway (cystathionine, methionine). Their disturbances may contribute to the neurodevelopmental and neurological phenotype of HPP.


Subject(s)
Alkaline Phosphatase/metabolism , Brain/metabolism , Disease Models, Animal , Hypophosphatasia/metabolism , Magnetic Resonance Spectroscopy/methods , Metabolomics/methods , Alkaline Phosphatase/deficiency , Animals , Female , Hypophosphatasia/genetics , Male , Mice , Mice, Knockout
15.
J Therm Biol ; 55: 39-46, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26724196

ABSTRACT

Alterations in lipid oxidation during exercise have been well studied, but limited data exists on the effects of passive heat exposure and exercise in the heat on changes in lipid oxidation. This study was designed to examine: (1) the effects of heat exposure on lipid metabolism during passive heating and subsequent exercise in the heat by focusing on changes in whole-body lipid oxidation and plasma lipid concentrations, and (2) the effects of extended passive pre-heating on exercise performance in the heat. Male participants (n=8) were passively heated for 120 min at 42 °C, then exercised on a treadmill in the same temperature at 50% V̇O2 max for 30 min (HEAT). This same procedure was followed on a separate occasion at 23 °C (CON). Results showed that lipid oxidation rates were not different between HEAT and CON during passive heating or exercise. However, non-esterified fatty acid (NEFA) concentrations were significantly higher following passive heating (618 µM, 95% CI: 479-757) compared to CON (391 µM, 95% CI: 270-511). The same trend was observed following exercise (2036 µM, 95% CI: 1604-2469 for HEAT and 1351 µM, 95% CI: 1002-1699). Triacylglycerol, phospholipid and cholesterol levels were not different between HEAT and CON at any point. Four of 8 participants could not complete 30 min of exercise in HEAT, resulting in a 14% decline in total external work. Rate of perceived exertion over the final 5 min of exercise was higher in HEAT (9.5) than CON (5). We conclude that: (1) heat exposure results in increased circulating NEFA at rest and during exercise without changes in whole-body lipid utilization, and (2) passive pre-heating reduces work capacity during exercise in the heat and increases the perceived intensity of a given workload.


Subject(s)
Body Temperature , Exercise , Fatty Acids/metabolism , Hot Temperature , Lipid Metabolism , Adult , Body Weight , Carbon Dioxide/metabolism , Exercise Test , Heart Rate , Humans , Lipids/blood , Male , Oxygen Consumption , Pulmonary Ventilation , Skin Temperature , Stress, Physiological , Thermogenesis , Young Adult
16.
Subcell Biochem ; 76: 239-81, 2015.
Article in English | MEDLINE | ID: mdl-26219715

ABSTRACT

Tissue non-specific alkaline phosphatase (TNAP) may be involved in the synthesis of GABA and adenosine, which are the main inhibitory neurotransmitters in cortex. We explored this putative TNAP function through electrophysiological recording (local field potential ) in slices of mouse somatosensory cortex maintained in vitro. We used tetramisole, a well documented TNAP inhibitor, to block TNAP activity. We expected that inhibiting TNAP with tetramisole would lead to an increase of neuronal response amplitude, owing to a diminished availability of GABA and/or adenosine. Instead, we found that tetramisole reduced neuronal response amplitude in a dose-dependent manner. Tetramisole also decreased axonal conduction velocity. Levamisole had identical effects. Several control experiments demonstrated that these actions of tetramisole were independent from this compound acting on TNAP. In particular, tetramisole effects were not stereo-specific and they were not mimicked by another inhibitor of TNAP, MLS-0038949. The decrease of axonal conduction velocity and preliminary intracellular data suggest that tetramisole blocks voltage-dependent sodium channels. Our results imply that levamisole or tetramisole should not be used with the sole purpose of inhibiting TNAP in living excitable cells as it will also block all processes that are activity-dependent. Our data and a review of the literature indicate that tetramisole may have at least four different targets in the nervous system. We discuss these results with respect to the neurological side effects that were observed when levamisole and tetramisole were used for medical purposes, and that may recur nowadays due to the recent use of levamisole and tetramisole as cocaine adulterants.


Subject(s)
Alkaline Phosphatase/antagonists & inhibitors , Cerebral Cortex/drug effects , Enzyme Inhibitors/pharmacology , Levamisole/pharmacology , Neurons/drug effects , Tetramisole/pharmacology , Alkaline Phosphatase/metabolism , Animals , Cerebral Cortex/metabolism , Dose-Response Relationship, Drug , Female , Mice , Neurons/physiology , Synaptic Transmission/drug effects
17.
J Psychohist ; 42(3): 188-99, 2015.
Article in English | MEDLINE | ID: mdl-25630195

ABSTRACT

This study explored predictions made from Lucille Iremonger's Phaeton theory (1970), which argues that individuals who show exceptional personal achievement in certain fields frequently have experienced childhoods that were marked by parental loss through death and desertion. Three groups were examined: eminent American writers, presidents of the USA, and the 100 Americans who were judged by Life magazine to have been the most influential in 20th century society. Bereavement was common in the childhoods of these outstanding individuals, but was also high, or even higher, for those individuals who achieved somewhat less eminence (less successful writers, and presidential also-rans). More than half the total set of the presidents and also-rans were orphans. Eminent Americans showed substantial although lower levels of parental loss, and nearly three-quarters had experienced difficult childhoods that were marked by some form of loss. Eminent Americans, like the presidents, tended to be first-borns; they also showed elevated levels of divorce, suicide, and name changing. The results provide support for the Phaeton theory, but suggest that the child's struggle to overcome other losses than bereavement may also promote eminence, as may the presence of significant mentors.


Subject(s)
Achievement , Famous Persons , Parental Death/psychology , Humans , United States
18.
Expert Opin Orphan Drugs ; 2(6): 567-577, 2014 Jun 01.
Article in English | MEDLINE | ID: mdl-25383264

ABSTRACT

INTRODUCTION: Pseudoxanthoma elasticum (PXE), a multisystem orphan disease, clinically affects the skin, the eyes, and the cardiovascular system with considerable morbidity and mortality. The clinical manifestations reflect the underlying pathology consisting of ectopic mineralization of peripheral connective tissues. AREAS COVERED: The diagnostic criteria of PXE include characteristic clinical findings, together with histopathology of accumulation of pleiomorphic elastic structures in the dermis with progressive mineralization, and the presence of mutations in the ABCC6 gene. PXE-like cutaneous changes can also be encountered in other ectopic mineralization disorders, including generalized arterial calcification of infancy (GACI) caused by mutations in the ENPP1 gene. In some cases, overlapping clinical features of PXE/GACI, associated with mutations either in ABCC6 or ENPP1, have been noted. PXE demonstrates considerable inter- and intrafamilial heterogeneity, and consequently, accurate diagnosis is required for appropriate classification with prognostic implications. There is no effective and specific treatment for the systemic manifestations of PXE, but effective therapies to counteract the ocular complications are in current clinical use. EXPERT OPINION: A number of observations in the murine model, the Abcc6-/- mouse, have indicated that the mineral composition of diet, particularly the magnesium content, can influence the severity of the mineralization phenotype. These observations suggest that appropriate dietary interventions, coupled with lifestyle modifications, including smoking cessation, might alleviate the symptoms and improve the quality of life of individuals affected with this, currently intractable, orphan disease.

20.
Psychol Rep ; 112(2): 533-44, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23833881

ABSTRACT

Previous research has suggested that motivational processes outside an individual's conscious awareness may be primed so as to enhance or impair cognitive performance. The present study involved a conceptual replication of the 2010 study of Ciani and Sheldon (Experiments 1 and 2), employing the same materials and task, to test whether exposure to the letter A before an analogies test improved performance and the letter F impaired it, relative to the neutral letter J. It also examined the effect of pre-exposing participants before testing to a positive or negative verbal passage concerning letter grades. Priming was not found to have any effect: the participants (N = 116), under both pre-exposure conditions, gave analogies scores which were virtually identical whether they had been primed with A, F, or J, thus contradicting the previous results. It is concluded that there is a pressing need for more replications of priming experiments as well as other studies.


Subject(s)
Achievement , Attention , Awareness , Motivation , Female , Humans , Male
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