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1.
Front Cell Neurosci ; 17: 1259712, 2023.
Article in English | MEDLINE | ID: mdl-38077953

ABSTRACT

Human induced pluripotent stem cells (hiPSCs) have been used extensively in vitro to model early events in neurodevelopment. Because of a number of shortcomings, previous work has established a potential to use these cells in vivo after transplantation into the mouse brain. Here, we describe a systematic approach for the analysis of transplanted hiPSC-derived neurons and glial cells over time in the mouse brain. Using functional two-photon imaging of GCaMP6f- expressing human neural cells, we define and quantify the embryonic-like features of their spontaneous activity. This is substantiated by detailed electron microscopy (EM) of the graft. We relate this to the synaptic development the neurons undergo up to 7 months in vivo. This system can now be used further for the genetic or experimental manipulation of developing hiPSC-derived cells addressing neurodevelopmental diseases like schizophrenia or Autism Spectrum Disorder.

2.
Water Hist ; 12(3): 281-297, 2020.
Article in English | MEDLINE | ID: mdl-33224321

ABSTRACT

In this article, we will present an overview of possible research methods to handle historical sources, in the specific case of karez landscapes. A karez system is an underground water collection system, prevalent in the Turpan basin of China. Sources and the associated methodology have become more important today, because of contemporary issues such as modernisation, urbanisation and agricultural expansion. These problems make it harder to read the landscape, which is why we have to start extracting our data from maps, reports, photographs, and satellite imagery. We will give a short overview of sources, each with an explanation of their processing method. Despite certain cautions that should be taken into account, these methods clearly complement the current state of knowledge on the Turpan karez. As this paper is part of a special issue, Water History in the time of COVID-19, it has undergone modified peer review.

3.
Sci Rep ; 10(1): 13315, 2020 08 07.
Article in English | MEDLINE | ID: mdl-32769989

ABSTRACT

Using human induced pluripotent stem cells (iPSC), recent studies have shown that the events underlying autism spectrum disorders (ASD) can occur during neonatal development. We previously analyzed the iPSC-derived pyramidal cortical neurons of a subset of patients with ASD carrying de novo heterozygous mutations in postsynaptic SHANK3 protein, in culture. We reported altered spinogenesis of those neurons. The transplantation of human iPSC-derived neuronal precursors into mouse brain represents a novel option for in vivo analysis of mutations affecting the human brain. In this study, we transplanted the neuronal precursor cells (NPC) into the cortex of newborn mice to analyze their integration and maturation at early stages of development and studied axonal projections of transplanted human neurons into adult mouse brain. We then co-transplanted NPC from a control individual and from a patient carrying a de novo heterozygous SHANK3 mutation. We observed a reduction in cell soma size of selective neuronal categories and in axonal projections at 30 days post-transplantation. In contrast to previous in vitro studies, we did not observe any alteration in spinogenesis at this early age. The humanized chimeric mouse models offer the means to analyze ASD-associated mutations further and provide the opportunity to visualize phenotypes in vivo.


Subject(s)
Autism Spectrum Disorder/metabolism , Induced Pluripotent Stem Cells/metabolism , Mutation , Nerve Tissue Proteins/metabolism , Neural Stem Cells , Pyramidal Cells/metabolism , Stem Cell Transplantation , Transplantation Chimera/metabolism , Animals , Autism Spectrum Disorder/genetics , Autism Spectrum Disorder/pathology , Cell Line , Disease Models, Animal , Heterografts , Humans , Induced Pluripotent Stem Cells/pathology , Mice , Mice, Inbred NOD , Mice, SCID , Nerve Tissue Proteins/genetics , Neural Stem Cells/metabolism , Neural Stem Cells/pathology , Neural Stem Cells/transplantation , Pyramidal Cells/pathology , Transplantation Chimera/genetics
4.
Chimia (Aarau) ; 74(7): 618-628, 2020 Aug 12.
Article in English | MEDLINE | ID: mdl-32778216

ABSTRACT

Numerous projects and industrial and academic collaborations benefit from state-of-the-art facilities and expertise in analytical chemistry available at the Swiss Universities of Applied Sciences. This review summarizes areas of expertise in analytical sciences at the University of Applied Sciences and Arts Northwestern Switzerland (FHNW), the University of Applied Sciences and Arts Western Switzerland (HES-SO), and the Zurich University of Applied Sciences (ZHAW). We briefly discuss selected projects in different fields of analytical sciences.

5.
Chem Sci ; 11(44): 11998-12008, 2020 Oct 07.
Article in English | MEDLINE | ID: mdl-34094421

ABSTRACT

Low-density lipoprotein (LDL)-mimetic lipid nanoparticles (LNPs), decorated with MRI contrast agents and fluorescent dyes, were prepared by the covalent attachment of apolipoprotein-mimetic peptide (P), Gd(iii)-chelate (Gd), and sulforhodamine B (R) moieties on the LNP surface. The functionalized LNPs were prepared using the amide-forming potassium acyltrifluoroborate (KAT) ligation reaction. The KAT groups on the surface of LNPs were allowed to react with the corresponding hydroxylamine (HA) derivatives of P and Gd to provide bi-functionalized LNPs (PGd-LNP). The reaction proceeded with excellent yields, as observed by ICP-MS (for B and Gd amounts) and MALDI-TOF-MS data, and did not alter the morphology of the LNPs (mean diameter: ca. 50 nm), as shown by DLS and cryoTEM analyses. With the help of the efficient KAT ligation, a high payload of Gd(iii)-chelate on the PGd-LNP surface (ca. 2800 Gd atoms per LNP) was successfully achieved and provided a high r 1 relaxivity (r 1 = 22.0 s-1 mM-1 at 1.4 T/60 MHz and 25 °C; r 1 = 8.2 s-1 mM-1 at 9.4 T/400 MHz and 37 °C). This bi-functionalized PGd-LNP was administered to three atherosclerotic apoE -/- mice to reveal the clear enhancement of atherosclerotic plaques in the brachiocephalic artery (BA) by MRI, in good agreement with the high accumulation of Gd in the aortic arch as shown by ICP-MS. The parallel in vivo MRI and ex vivo studies of whole mouse cryo-imaging were performed using triply functionalized LNPs with P, Gd, and R (PGdR-LNP). The clear presence of atherosclerotic plaques in BA was observed by ex vivo bright field cryo-imaging, and they were also observed by high emission fluorescent imaging. These directly corresponded to the enhanced tissue in the in vivo MRI of the identical mouse.

6.
Environ Pollut ; 248: 1088-1097, 2019 May.
Article in English | MEDLINE | ID: mdl-30871891

ABSTRACT

Microplastics (MPs), are tiny plastic fragments from 1 µm to 5 mm generally found in the aquatic environment which can be easily ingested by organisms and may cause chronic physical but also toxicological effects. Toxicological assays on fish cell lines are commonly used as an alternative tool to provide fast and reliable assessment of the toxic and ecotoxic properties of chemicals or mixtures. Rainbow trout liver cell line (RTLW-1) was used to evaluate the toxicity of pollutants sorbed to MPs sampled in sandy beaches from different islands around the world during the first Race for Water Odyssey in 2015. The collected MPs were analyzed for polymer composition and associated persistent organic pollutants: polycyclic aromatic hydrocarbons (PAHs), polychlorobiphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT). In addition, DMSO-extracts from virgin MPs, MPs artificially coated with B[a]P and environmental MPs were analyzed with different bioassays: MTT reduction assay (MTT), ethoxyresorufin-O-deethylase (EROD) assay and comet assay. Microplastics from sand beaches were dominated by polyethylene, followed by polypropylene fragments with variable proportions. Organic pollutants found on plastic from beach sampling was PAHs (2-71 ng g-1). Samples from Bermuda (Somerset Long Bay) and Hawaii (Makapu'u) showed the highest concentration of PAHs and DDT respectively. No toxicity was observed for virgin microplastics. No cytotoxicity was observed on cells exposed to MP extract. However, EROD activity was induced and differently modulated depending on the MPs locations suggesting presence of different pollutants or additives in extract. DNA damage was observed after exposure to four microplastics samples on the six tested. Modification of EROD activity level and DNA damage rate highlight MPs extract toxicity on fish cell line.


Subject(s)
Bathing Beaches , Environmental Monitoring/methods , Oncorhynchus mykiss/metabolism , Plastics/toxicity , Water Pollutants, Chemical/toxicity , Animals , Cell Line , Cell Survival/drug effects , Cytochrome P-450 CYP1A1/metabolism , DDT/analysis , DDT/toxicity , DNA Damage , Hawaii , Liver/cytology , Liver/drug effects , Liver/enzymology , Oncorhynchus mykiss/genetics , Plastics/analysis , Polychlorinated Biphenyls/analysis , Polychlorinated Biphenyls/toxicity , Polycyclic Aromatic Hydrocarbons/analysis , Polycyclic Aromatic Hydrocarbons/toxicity , Toxicity Tests , Water Pollutants, Chemical/analysis
7.
Crit Ultrasound J ; 10(1): 31, 2018 Nov 23.
Article in English | MEDLINE | ID: mdl-30467798

ABSTRACT

BACKGROUND: Right iliac fossa abdominal pain is a common reason for emergency ward admissions, its etiology is difficult to diagnose. It can be facilitated by an imaging examination, such as a Computerized Tomography scan which exposes the patient to ionizing radiation and implies delays. A bedside ultrasound performed by emergency physicians could avoid these issues. The aim of our study was to assess the performance of ultrasound carried out at the patient's bedside by an emergency physician compared with a clinical-laboratory examination for the diagnosis of a surgical pathology in right iliac fossa pain. METHODS: This is a single-center prospective cohort study conducted in an Emergency Department receiving 19,000 patients per year. All patients presenting pain in the right iliac fossa were included by four (out of ten) emergency physicians certified in an ultrasound examination. A full grid pattern scan ultrasound of the abdominal cavity with analysis of the right iliac fossa was performed. The primary outcome was to compare the diagnosis performance of bedside ultrasound and clinical-laboratory examination to detect a surgical pathology. Two emergency physicians who did not participate in the study made the final diagnosis (i.e., surgical or non-surgical pathology) by reviewing the entire medical chart of each patient. RESULTS: From January 2011 to July 2013, 158 patients with a median age of 17 [13-32] years were analyzed. The diagnosed cases were: appendicitis (53), non-specific abdominal pain (48), lymphadenitis (22), ileitis (11), complicated ovarian cysts (7), neoplasias (5), inflammatory or infectious colitis (5), inguinal herniations (3), bowel obstructions (2), and salpingitis (2). The accuracy of ultrasound diagnoses was 0.89 (95% CI 0.84-0.94) versus 0.70 (95% CI 0.57-0.82) for diagnoses based on clinical-laboratory examination only (p < 0.001). CONCLUSION: Bedsides, ultrasound allows an accurate diagnosis of a surgical pathology in 89% of cases, which is more efficient than the clinical-laboratory examination.

8.
Chimia (Aarau) ; 72(12): 905-906, 2018 Dec 19.
Article in English | MEDLINE | ID: mdl-30648962

ABSTRACT

We have successfully built a low-cost (under 500 CHF) portable Raman spectrometer based on scavenged, consumer electronics. The instrument prototype is designed as a tool to help identify counterfeit medication in low-income countries. As a proof of concept, we confirmed the presence of acetaminophen, a type of analgesic, in over-the-counter drugs from around the world.


Subject(s)
Counterfeit Drugs/chemistry , Spectrum Analysis, Raman/instrumentation , Spectrum Analysis, Raman/methods
9.
Int Marit Health ; 68(1): 46-51, 2017.
Article in English | MEDLINE | ID: mdl-28357836

ABSTRACT

BACKGROUND: To evaluate the epidemiology of patients who require mechanical ventilation during hyperbaric oxygen therapy. MATERIALS AND METHODS: One-hundred-fifty patients who required mechanical ventilation during hyperbaric oxygen therapy were prospectively studied during a 6-year period in a French university hyperbaric centre. We analysed the indication of hyperbaric oxygen therapy, agent used for sedation, presence of a chest tube, need for vasopressor agents and tolerance and appearance of side effects. Finally, we compared the outcomes of patients according to the presence or absence of acute respiratory distress syndrome (ARDS). RESULTS: Eleven children and 139 adult patients were included (n = 150) in the study. In both populations, carbon monoxide poisoning (51%) and iatrogenic gas embolism (33%) were the two main causes of intubation and mechanical ventilation. The combination of midazolam and sufentanil was used in 85 (67%) patients. All of the patients were given a bolus of a neuromuscular blocker during the hyperbaric session, despite the presence of ARDS in 35 patients. Patient-ventilator asynchrony was the most frequent side effect in 6 (5%) patients and was often the consequence of suboptimal sedation. Mortality was higher in the group with ARDS (23%). CONCLUSIONS: Carbon monoxide poisoning and iatrogenic gas embolism are the two main diseases of the patients who required mechanical ventilation during hyperbaric oxygen therapy in this study. Mechanical ventilation is a safe method for patients during hyperbaric oxygen therapy. Sedation needs to be perfected to avoid patient-ventilator asynchrony.


Subject(s)
Hyperbaric Oxygenation/adverse effects , Hypnotics and Sedatives/administration & dosage , Respiration, Artificial/adverse effects , Adult , Carbon Monoxide Poisoning/therapy , Chest Tubes , Child , Embolism, Air/therapy , Female , France , Humans , Hyperbaric Oxygenation/methods , Iatrogenic Disease , Male , Respiratory Distress Syndrome/mortality , Respiratory Distress Syndrome/therapy , Vasoconstrictor Agents/therapeutic use , Ventilators, Mechanical/adverse effects
10.
Chimia (Aarau) ; 70(12): 900-901, 2016 Dec 21.
Article in English | MEDLINE | ID: mdl-28661367

ABSTRACT

The fermentation of yeast in fed-batch mode shows great potential in winemaking because it allows the concentration of sugars to be kept low and constant throughout the process which, in turn, reduces cell stress and leads to a significant decrease in the production of unwanted secondary metabolites. The implementation of this technique requires reliable on-line analysis of sugar and a robust control strategy to maintain sugar concentrations at defined levels over the course of the fermentation. In this study, a laboratory-scale setup was used to implement and assess a fully automated fed-batch fermentation of Saccharomyces cerevisiae in grape must. Total sugar levels were monitored in-line by FT-MIR ATR spectroscopy and kept constant at 50 g/kg by a modified PI controller regulating the must feed flow rate. Good setpoint tracking and disturbance rejection were achieved in fermentations of up to four days despite occasional yeast sedimentation on the ATR crystal. The controller parameter adaptation strategy needs to be optimized for longer fermentations.


Subject(s)
Batch Cell Culture Techniques/methods , Fermentation , Saccharomyces cerevisiae/metabolism , Wine/microbiology , Batch Cell Culture Techniques/instrumentation , Carbohydrates/analysis , Time Factors
11.
Am J Emerg Med ; 33(3): 352-8, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25572643

ABSTRACT

OBJECTIVE: The etiologic diagnosis of acute dyspnea in the emergency department (ED) remains difficult, especially for elderly patients or those with previous cardiorespiratory medical history. This may lead to inappropriate treatment and potentially a higher mortality rate. Our objective was to evaluate the performance of cardiopulmonary ultrasound compared with usual care for the etiologic diagnosis of acute dyspnea in the ED. METHODS: Patients admitted to the ED for acute dyspnea underwent upon arrival a cardiopulmonary ultrasound performed by an emergency physician, in addition to standard care. The performances of the clinical examination, chest x-ray, N-terminal brain natriuretic peptide (NT-proBNP), and cardiopulmonary ultrasound were compared with the final diagnosis made by 2 independent physicians. RESULTS: One hundred thirty patients were analyzed. For the diagnosis of acute left-sided heart failure, cardiopulmonary ultrasound had an accuracy of 90% (95% confidence interval [CI], 84-95) vs 67% (95% CI, 57-75), P = .0001 for clinical examination, and 81% (95% CI, 72-88), P = .04 for the combination "clinical examination-NT-proBNP-x-ray". Cardiopulmonary ultrasound led to the diagnosis of pneumonia or pleural effusion with an accuracy of 86% (95% CI, 80-92) and decompensated chronic obstructive pulmonary disease or asthma with an accuracy of 95% (95% CI, 92-99). Cardiopulmonary ultrasound lasted an average of 12 ± 3 minutes. CONCLUSIONS: Cardiopulmonary ultrasounds performed in the ED setting allow one to rapidly establish the etiology of acute dyspnea with an accuracy of 90%.


Subject(s)
Asthma/diagnostic imaging , Dyspnea/etiology , Echocardiography , Heart Failure/diagnostic imaging , Lung/diagnostic imaging , Pleural Effusion/diagnostic imaging , Pneumonia/diagnostic imaging , Pulmonary Disease, Chronic Obstructive/diagnostic imaging , Aged , Aged, 80 and over , Asthma/complications , Asthma/diagnosis , Cohort Studies , Disease Progression , Emergency Service, Hospital , Female , Heart Failure/complications , Heart Failure/diagnosis , Humans , Male , Natriuretic Peptide, Brain/blood , Peptide Fragments/blood , Physical Examination , Pleural Effusion/complications , Pleural Effusion/diagnosis , Pneumonia/complications , Pneumonia/diagnosis , Prospective Studies , Pulmonary Disease, Chronic Obstructive/complications , Pulmonary Disease, Chronic Obstructive/diagnosis , Radiography, Thoracic , Sensitivity and Specificity
12.
Soft Matter ; 10(17): 3086-92, 2014 May 07.
Article in English | MEDLINE | ID: mdl-24695908

ABSTRACT

Metallo-supramolecular micellar hydrogels exhibiting thermo-mechanical responsiveness are prepared through the hierarchical assembly of a heterotelechelic associating copolymer. The copolymer consists of a linear thermo-sensitive water-soluble sequence terminated by a short hydrophobic sticker at one end, the other being functionalized by a chelating ligand. As the first level of assembly, the associating copolymer is dissolved in aqueous solution to yield micellar nanostructures, bearing coordinative motifs at the end of the coronal chains. The second level of assembly is achieved when transition metal ions are added to the micellar solutions, resulting in almost instantaneous gelation. The thermo-mechanical response of those materials is investigated in detail by rotational rheometry, showing abrupt changes within the temperature boundaries corresponding to the phase transition of the polymer block located in the micellar corona.

13.
Am J Emerg Med ; 32(2): 115-8, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24184011

ABSTRACT

OBJECTIVE: The aim of our study was to assess the potential of bedside lung ultrasound examination by the attending emergency physician in the diagnosis of acute pneumonia. MATERIAL AND METHODS: This observational single-center study was conducted between January 2010 and June 2012 in the emergency unit of a general hospital, and analyzed 144 adult patients. The ultrasound examination was performed by one of five trained emergency physicians, and a chest radiograph interpreted by a radiologist. The primary end point was the diagnosis of hospital discharge. RESULTS: We found a sensitivity of 0.95 for the ultrasound examination against 0.6 for radiography (P < .05). The negative predictive value was 0.67 against 0.25 for radiography (P < .05). CONCLUSION: These results exhort to promote the use of thoracic ultrasound in the first-line diagnosis of pneumonia.


Subject(s)
Emergency Service, Hospital , Lung/diagnostic imaging , Pneumonia/diagnosis , Aged , Female , Humans , Male , Pneumonia/diagnostic imaging , Point-of-Care Systems , Radiography, Thoracic , Sensitivity and Specificity , Tomography, X-Ray Computed , Ultrasonography
14.
Macromol Rapid Commun ; 35(2): 228-233, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24127365

ABSTRACT

This contribution describes the synthesis of block copolymers containing electrochemically active blocks, their micellization, and finally their use as micellar cathodes in a lithium battery. The self-assembly of the synthesized poly(styrene)-block-poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate) (PS-b-PTMA) diblock copolymers is realized in a typical battery electrolyte made of 1 m lithium trifluoromethanesulfonate dissolved in a mixture of ethylene carbonate/diethyl carbonate/dimethyl carbonate(1:1:1, in volume). Dynamic light scattering and atomic force micro-scopy indicate the formation of well-defined spherical micelles with a PS core and a PTMA corona. The electrochemical properties of those micelles are further investigated. Cyclic voltammograms show a reversible redox reaction at 3.6 V (vs Li(+) /Li). The charge/discharge profiles indicate a flat and reversible plateau around 3.6 V (vs Li(+) /Li). Finally, the cycling performances of the micellar cathodes are demonstrated. Such self-assembled block copolymers open new opportunities for nanostructured organic radical batteries.


Subject(s)
Electric Power Supplies , Electrodes , Electrolytes/chemistry , Micelles , Nitrogen Oxides/analysis , Polymers/chemistry , Microscopy, Atomic Force
15.
FASEB J ; 26(10): 3969-79, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22730440

ABSTRACT

Antibodies normally do not cross the blood-brain barrier (BBB) and cannot bind an intracellular cerebral antigen. We demonstrate here for the first time that a new class of antibodies can cross the BBB without treatment. Camelids produce native homodimeric heavy-chain antibodies, the paratope being composed of a single-variable domain called VHH. Here, we used recombinant VHH directed against human glial fibrillary acidic protein (GFAP), a specific marker of astrocytes. Only basic VHHs (e.g., pI=9.4) were able to cross the BBB in vitro (7.8 vs. 0% for VHH with pI=7.7). By intracarotid and intravenous injections into live mice, we showed that these basic VHHs are able to cross the BBB in vivo, diffuse into the brain tissue, penetrate into astrocytes, and specifically label GFAP. To analyze their ability to be used as a specific transporter, we then expressed a recombinant fusion protein VHH-green fluorescent protein (GFP). These "fluobodies" specifically labeled GFAP on murine brain sections, and a basic variant (pI=9.3) of the fusion protein VHH-GFP was able to cross the BBB and to label astrocytes in vivo. The potential of VHHs as diagnostic or therapeutic agents in the central nervous system now deserves attention.


Subject(s)
Astrocytes/metabolism , Blood-Brain Barrier/metabolism , Brain/metabolism , Glial Fibrillary Acidic Protein/metabolism , Single-Domain Antibodies/metabolism , Animals , Astrocytoma/metabolism , Cell Line , Cell Line, Tumor , Enzyme-Linked Immunosorbent Assay , Female , Fluorescent Antibody Technique , Glial Fibrillary Acidic Protein/genetics , Glial Fibrillary Acidic Protein/immunology , Humans , Immunohistochemistry , Mice , Mice, Inbred C57BL , Mutagenesis, Site-Directed , Plasmodium berghei/pathogenicity , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Single-Domain Antibodies/genetics , Single-Domain Antibodies/immunology
16.
Cereb Cortex ; 22(5): 1007-15, 2012 May.
Article in English | MEDLINE | ID: mdl-21810785

ABSTRACT

Organization of locomotor behavior is altered in mice knockout for the ß2 subunit of the nicotinic receptor-ß2-/- mice-during novelty exploration. We investigated the neuronal basis of this alteration by measuring activation of the immediate early gene c-fos in the brains of wild-type (WT) and ß2-/- mice after exploration of a novel or a familiar environment. Results show 1) no constitutive difference between WT and ß2-/- mice in c-fos gene expression in any brain region, 2) novelty exploration triggered activation of the hippocampus and the reward circuit while exploration of a familiar environment produced increased activation in the amygdala, and 3) in ß2-/- mice, exploration of novelty, but not familiarity, induced an increase in activation in the prelimbic prefrontal cortex (PFC) compared with WT mice. c-Fos immunoreactivity after different stages of learning in a maze increased similarly in the prelimbic area of both WT and ß2-/- mice, while their performance differed. In WT mice, exploration of a novel environment triggered an increase in c-Fos expression in the reward circuit and the hippocampus, while in ß2-/- mice, the amygdala and the motor cortex were additionally activated. We also highlight the role of nicotinic receptors during activation of the PFC, specifically during free exploration of a novel environment.


Subject(s)
Exploratory Behavior/physiology , Neurons/metabolism , Prefrontal Cortex/metabolism , Receptors, Nicotinic/metabolism , Animals , Gene Expression Profiling , Immunohistochemistry , Maze Learning/physiology , Mice , Mice, Inbred C57BL , Mice, Knockout , Proto-Oncogene Proteins c-fos/analysis , Proto-Oncogene Proteins c-fos/biosynthesis , Receptors, Nicotinic/deficiency , Reward
17.
FASEB J ; 25(7): 2145-55, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21402717

ABSTRACT

Social behavior is a defining mammalian feature that integrates emotional and motivational processes with external rewarding stimuli. It is thus an appropriate readout for complex behaviors, yet its neuronal and molecular bases remain poorly understood. In this study, we investigated the role of the mouse prefrontal area, particularly the involvement of ß2-subunit nicotinic receptors (ß2*-nAChRs) in a paradigm of social behavior with concurrent motivations. We previously observed that mice lacking ß2*-nAChRs (ß2(-/-)) display increased time in social contact and exaggerated approach movements toward the novel conspecific. Here, combining behavioral analysis, localized brain lesions, and lentiviral gene rescue, we found that c-Fos expression is specifically activated in the prelimbic (PrL) area of the prefrontal cortex (PFC) of mice exposed to a novel conspecific; lesions of the PrL area in wild-type mice produce the same social pattern as in ß2(-/-) mice; and virally mediated reexpression of the ß2-subunit in the PrL area of ß2(-/-) mice rescues behavioral components in the social interaction task up to normal levels. Together, these data reveal that social interactions particularly mobilize the PrL area of the mouse PFC and that the presence of functional PrL ß2*-nAChRs is necessary for this integrated behavior to emerge.


Subject(s)
Exploratory Behavior/physiology , Prefrontal Cortex/physiopathology , Receptors, Nicotinic/physiology , Social Behavior , Animals , Autoradiography , Binding, Competitive , Brain/metabolism , Brain/pathology , Brain/physiopathology , Bridged Bicyclo Compounds, Heterocyclic/metabolism , Female , Genetic Complementation Test , HEK293 Cells , Humans , Immunohistochemistry , Iodine Radioisotopes , Lentivirus/genetics , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Motor Activity/genetics , Motor Activity/physiology , Prefrontal Cortex/metabolism , Prefrontal Cortex/pathology , Proto-Oncogene Proteins c-fos/metabolism , Pyridines/metabolism , Receptors, Nicotinic/genetics , Receptors, Nicotinic/metabolism , Transfection
18.
J Photochem Photobiol B ; 103(1): 8-15, 2011 Apr 04.
Article in English | MEDLINE | ID: mdl-21300553

ABSTRACT

Pure luteolin is a remarkably heat (200°C/6 days) and UV stable UV-A screen, however, native luteolin enriched to 37% in an edelweiss extract lost its UV-A screen properties upon UV irradiation (∼4MJm(-2)). This contrasting behavior led to the examination of a series of purified luteolin derivatives as UV screen candidates. 3',4',5,7-Tetralipoyloxyflavones were synthesized from luteolin (3',4',5,7-tetrahydroxyflavone) and fatty acid chlorides. These acylated semi-biomolecules show a hypsochromic shift in UV-Vis spectra of about Δλ(A→B)=58nm and absorbed in the centre of the harmful UV-B band (λ(max)=295nm). Luteolin was also hydroxyethylated with Br(CH(2))(2)OH. This substitution has no effect on the λ(max)=330nm absorption of luteolin (UV-A band). Finally the natural 4'-O-ß-glucosyl-3',5,7-trihydroxyflavone was extracted from edelweiss and used as a purified natural benchmark. Glycosylated and hydroxyethylated luteolin are both UV stable. Fully acylated luteolin derivatives degrade upon UV exposure to a stable UV-C screen with a hypsochroic shift Δλ(B→C)=35nm. All in all, three molecular structures based on luteolin with sunscreen properties were found, distinguishable in: UV-A, UV-B, and UV-C filters. The natural product based UV-absorbers show promise as alternatives to synthetic molecules and nanoparticles in sunscreen products.


Subject(s)
Asteraceae/chemistry , Luteolin/chemistry , Plant Extracts/chemistry , Sunscreening Agents/chemistry , Ultraviolet Rays , Absorption , Acylation , Drug Stability , Glycosylation , Luteolin/chemical synthesis , Luteolin/isolation & purification , Sunscreening Agents/chemical synthesis , Sunscreening Agents/isolation & purification
19.
Proc Natl Acad Sci U S A ; 107(25): 11567-72, 2010 Jun 22.
Article in English | MEDLINE | ID: mdl-20534523

ABSTRACT

The neuronal nicotinic acetylcholine receptors (nAChRs) are allosteric membrane proteins involved in multiple cognitive processes, including attention, learning, and memory. The most abundant form of heterooligomeric nAChRs in the brain contains the beta2- and alpha4- subunits and binds nicotinic agonists with high affinity. In the present study, we investigated in the mouse the consequences of the deletion of one of the nAChR components: the beta2-subunit (beta2(-/-)) on the microanatomy of cortical pyramidal cells. Using an intracellular injection method, complete basal dendritic arbors of 650 layer III pyramidal neurons were sampled from seven cortical fields, including primary sensory, motor, and associational areas, in both beta2(-/-) and WT animals. We observed that the pyramidal cell phenotype shows significant quantitative differences among different cortical areas in mutant and WT mice. In WT mice, the density of dendritic spines was rather similar in all cortical fields, except in the prelimbic/infralimbic cortex, where it was significantly higher. In the absence of the beta2-subunit, the most significant reduction in the density of spines took place in this high-order associational field. Our data suggest that the beta2-subunit is involved in the dendritic morphogenesis of pyramidal neurons and, in particular, in the circuits that contribute to the high-order functional connectivity of the cerebral cortex.


Subject(s)
Pyramidal Cells/cytology , Receptors, Nicotinic/metabolism , Animals , Cerebral Cortex/metabolism , Dendrites/metabolism , Dendritic Cells/cytology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Models, Biological , Mutation , Neurons/metabolism , Phenotype
20.
Acta Neuropathol ; 118(5): 685-95, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19597828

ABSTRACT

Camelids produce antibodies made of homodimeric heavy chains, and the antigen-binding region being composed of a single domain called VHH. These VHHs are much smaller than complete IgG. They are also more thermostable and more soluble in water; they should, therefore, diffuse more readily in the tissues. VHHs, expressed in bacteria, are easier to produce than conventional monoclonal antibodies. Because of these special characteristics, these antibody fragments could have interesting developments in immunohistochemistry and in the development of biomarkers. To test the possibility of their use in immunohistochemistry (IHC), we selected the glial fibrillary acidic protein (GFAP), a well-known marker of astrocytes. One alpaca (Lama pacos) was immunized against GFAP. Lymphocytes were isolated; the DNA was extracted; the VHH-coding sequences were selectively amplified. Three VHHs with a high affinity for GFAP and their corresponding mRNA were selected by ribosome display. Large quantities of the recombinant VHHs coupled with different tags were harvested from transfected bacteria. One of them was shown to immunolabel strongly and specifically to GFAP of human astrocytes in tissue sections. The quality of the IHC was comparable or, in some aspects, superior to the quality obtained with conventional IgG. The VHH was shown to diffuse on a longer distance than conventional monoclonal antibodies in fixed cortical tissue: a property that may be useful in immunolabeling of thick sections.


Subject(s)
Camelids, New World/immunology , Glial Fibrillary Acidic Protein/immunology , Immunoglobulin Heavy Chains/immunology , Recombinant Proteins/immunology , Single-Chain Antibodies/immunology , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Animals , Antibodies, Monoclonal/immunology , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Cerebral Cortex/metabolism , Enzyme-Linked Immunosorbent Assay/methods , Gene Expression , Gene Library , Glial Fibrillary Acidic Protein/metabolism , Humans , Immunoglobulin Heavy Chains/genetics , Male , Molecular Weight , RNA, Messenger/metabolism , Recombinant Proteins/genetics , Single-Chain Antibodies/genetics
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