327 results on '"Melis, C."'
Search Results
152. Clinicopathological characteristics of de novo and secondary myeloid sarcoma: A monocentric retrospective study.
- Author
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Claerhout H, Van Aelst S, Melis C, Tousseyn T, Gheysens O, Vandenberghe P, Dierickx D, and Boeckx N
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Biomarkers, Biopsy, Bone Marrow pathology, Child, Child, Preschool, Combined Modality Therapy, Diagnostic Imaging, Female, Humans, Immunohistochemistry, Infant, Male, Middle Aged, Molecular Diagnostic Techniques, Phenotype, Sarcoma, Myeloid etiology, Sarcoma, Myeloid mortality, Sarcoma, Myeloid therapy, Young Adult, Sarcoma, Myeloid diagnosis
- Abstract
Objective: Diagnosing myeloid sarcoma remains challenging, and we aimed to provide clinicopathological features to facilitate diagnosis., Method: Clinicopathological data from 41 patients with de novo and 31 with secondary myeloid sarcoma were reviewed., Results: Most de novo cases presented with isolated myeloid sarcoma (n = 19) or myeloid sarcoma with concurrent acute myeloid leukemia (n = 15). Most secondary cases presented after acute myeloid leukemia (n = 11), myeloproliferative neoplasm (n = 9), or myelodysplastic syndrome (n = 8). Most frequent localizations were skin and lymph nodes. Immunohistochemistry showed immature and/or aberrant antigenic expression in 29% of de novo and 39% of secondary cases. Most genetic abnormalities were RUNX1-RUNX1T1 (n = 4), CBFB-MYH11 (n = 2), KMT2A-MLLT3 (n = 2), and JAK2 V617F (n = 2) mutations in de novo myeloid sarcoma, and BCR-ABL1 (n = 5) and KMT2A rearrangements (n = 2) in secondary cases. A complex karyotype was seen in 17% of de novo and 39% of secondary cases. Most prevalent treatment was induction chemotherapy followed by consolidation chemotherapy (n = 10) or allogeneic stem cell transplantation (n = 9) for de novo and radiotherapy (n = 11) for secondary cases., Conclusion: De novo myeloid sarcoma mostly presented isolated. Lesions were often localized at skin and lymph nodes. Genetic aberrations frequently involved core-binding factor rearrangements in de novo cases and a complex karyotype in secondary cases., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)
- Published
- 2018
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153. Curious Residents of the Thyroid Gland: Two Case Reports of Colorectal Carcinoma Metastasis by Fine-Needle Aspiration Diagnosis.
- Author
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Melis C, Ballaux F, and Bourgain C
- Subjects
- Adenocarcinoma chemistry, Adenocarcinoma surgery, Adenocarcinoma, Follicular chemistry, Adenocarcinoma, Follicular surgery, Aged, Biomarkers, Tumor analysis, Colorectal Neoplasms chemistry, Disease Progression, Fatal Outcome, Female, Humans, Immunohistochemistry, Keratin-20 analysis, Male, Middle Aged, Predictive Value of Tests, Thyroid Neoplasms chemistry, Thyroid Neoplasms surgery, Thyroidectomy, Treatment Outcome, Adenocarcinoma secondary, Adenocarcinoma, Follicular pathology, Biopsy, Fine-Needle, Colorectal Neoplasms pathology, Thyroid Neoplasms secondary
- Abstract
Background: The most frequent metastases to the thyroid originate in the kidney, lung or breast. Colorectal adenocarcinoma represents less than 4% of metastases to the thyroid gland. Solitary metastases of colorectal cancer with no other manifestation of disseminated cancer disease are exceedingly rare. Within the Bethesda Classification for Reporting -Thyroid Cytopathology, metastases are included in Diagnostic Categories "Suspicious for Malignancy" and "Malignant.", Cases: We present 2 cases of colorectal adenocarcinoma metastatic to the thyroid gland, diagnosed by fine-needle aspiration (FNA). One metastasis occurred in normal thyroid parenchyma; the other was a tumour-to-tumour metastasis into a follicular carcinoma of the thyroid. The latter is the first published tumour-to-tumour metastasis of a colorectal carcinoma in the thyroid from which both components were diagnosed by FNA., Conclusion: Diagnosing a metastasis to the thyroid is challenging. On FNA, a dual cell population should raise suspicion. Immunocytochemical and molecular analysis may be helpful. Clinical information is essential in guiding specific ancillary technique panels in scant cellular material., (© 2018 S. Karger AG, Basel.)
- Published
- 2018
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154. Isatin thiazoline hybrids as dual inhibitors of HIV-1 reverse transcriptase.
- Author
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Meleddu R, Distinto S, Corona A, Tramontano E, Bianco G, Melis C, Cottiglia F, and Maccioni E
- Subjects
- Anti-HIV Agents chemical synthesis, Anti-HIV Agents chemistry, Dose-Response Relationship, Drug, HIV Reverse Transcriptase metabolism, HIV-1 drug effects, Humans, Isatin chemistry, Microbial Sensitivity Tests, Models, Molecular, Molecular Structure, Reverse Transcriptase Inhibitors chemical synthesis, Reverse Transcriptase Inhibitors chemistry, Structure-Activity Relationship, Thiazoles chemistry, Anti-HIV Agents pharmacology, HIV Reverse Transcriptase antagonists & inhibitors, Isatin analogs & derivatives, Isatin pharmacology, Reverse Transcriptase Inhibitors pharmacology, Thiazoles pharmacology
- Abstract
A series of 3-3-{2-[2-3-methyl-4-phenyl-2,3-dihydro-1,3-thiazol-2-ylidene]hydrazin-1-ylidene-2,3-dihydro-1H-indol-2-one derivatives has been designed and synthesized to study their activity on both HIV-1 (Human Immunodeficiency Virus type 1) RT (Reverse Transcriptase) associated functions. These derivatives are analogs of previously reported series whose biological activity and mode of action have been investigated. In this work we investigated the influence of the introduction of a methyl group in the position 3 of the dihydrothiazole ring and of a chlorine atom in the position 5 of the isatin nucleus. The new synthesized compounds are active towards both DNA polymerase and ribonuclease H in the µM range. The nature of the aromatic group in the position 4 of the thiazole was relevant in determining the biological activity.
- Published
- 2017
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155. Through scaffold modification to 3,5-diaryl-4,5-dihydroisoxazoles: new potent and selective inhibitors of monoamine oxidase B.
- Author
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Meleddu R, Distinto S, Cirilli R, Alcaro S, Yanez M, Sanna ML, Corona A, Melis C, Bianco G, Matyus P, Cottiglia F, and Maccioni E
- Subjects
- Isoxazoles chemistry, Models, Molecular, Monoamine Oxidase Inhibitors chemistry, Structure-Activity Relationship, Isoxazoles pharmacology, Monoamine Oxidase metabolism, Monoamine Oxidase Inhibitors pharmacology
- Abstract
3,5-Diaryl-4,5-dihydroisoxazoles were synthesized and evaluated as monoamine oxidase (MAO) enzyme inhibitors and iron chelators. All compounds exhibited selective inhibitory activity towards the B isoform of MAO in the nanomolar concentration range. The best performing compound was preliminarily evaluated for its ability to bind iron II and III cations, indicating that neither iron II nor iron III is coordinated. The best compounds racemic mixtures were separated and single enantiomers inhibitory activity evaluated. Furthermore, none of the synthesised compounds exhibited activity towards MAO A. Overall, these data support our hypothesis that 3,5-diaryl-4,5-dihydroisoxazoles are promising scaffolds for the design of neuroprotective agents.
- Published
- 2017
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156. Isatin: a privileged scaffold for the design of carbonic anhydrase inhibitors.
- Author
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Melis C, Meleddu R, Angeli A, Distinto S, Bianco G, Capasso C, Cottiglia F, Angius R, Supuran CT, and Maccioni E
- Subjects
- Carbonic Anhydrase Inhibitors chemistry, Isatin chemistry, Carbonic Anhydrase Inhibitors pharmacology, Drug Design, Isatin pharmacology
- Abstract
The isatin scaffold is the constitutive fragment of several natural and synthetic bioactive molecules. Albeit several benzene sulphonamide-based carbonic anhydrase inhibitors (CAIs) have been reported, only recently isatin benzene sulphonamides have been studied and proposed as CAIs. In this study we have designed, synthesised, and evaluated the biological activity of a series of differently substituted isatin-based benzene sulphonamides which have been designed for the inhibition of carbonic anhydrase isoforms. The activity of all the synthesised compounds was evaluated towards human carbonic anhydrase I, II, IX, and XII isozymes. Our results indicate that the nature and position of substituents on the isatin ring can modulate both activity and isozyme selectivity.
- Published
- 2017
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157. Phenylpropenoids from Bupleurum fruticosum as Anti-Human Rhinovirus Species A Selective Capsid Binders.
- Author
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Fois B, Bianco G, Sonar VP, Distinto S, Maccioni E, Meleddu R, Melis C, Marras L, Pompei R, Floris C, Caboni P, and Cottiglia F
- Subjects
- Antiviral Agents chemistry, Bupleurum, HeLa Cells, Humans, Models, Molecular, Molecular Structure, Monoterpenes chemistry, Phenylpropionates chemistry, Plant Leaves chemistry, Structure-Activity Relationship, Virus Replication drug effects, Antiviral Agents isolation & purification, Antiviral Agents pharmacology, Capsid drug effects, Enterovirus drug effects, Monoterpenes isolation & purification, Monoterpenes pharmacology, Phenylpropionates isolation & purification, Phenylpropionates pharmacology, Rhinovirus drug effects
- Abstract
The dichloromethane extract of the leaves of Bupleurum fruticosum was found to inhibit the replication of human rhinovirus (HRV) serotypes 14 and 39. Bioassay-guided fractionation led to the isolation of seven phenylpropenol derivatives (3-9), two polyacetylenes (1 and 2), and one monoterpene (10). Compounds 1 and 10 were identified as previously undescribed secondary metabolites after extensive 1D and 2D NMR experiments as well as high-resolution mass spectrometry. Compounds 2, 4, and 5 showed a selective inhibition of viral replication against HRV39 serotype, with 2 and 4 being the most active, with EC
50 values of 1.8 ± 0.02 and 2.4 ± 0.04 μM. Mechanism of action studies indicated that 4 behaves not only as a capsid binder, interfering with the early phases of virus replication, but also as a late-phase replication inhibitor. Docking experiments were performed to confirm the ability of the antiviral phenylpropenoids to selectively fit into the hydrophobic pocket of VP1-HRV39.- Published
- 2017
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158. Diagnostics of dysimmune peripheral neuropathies.
- Author
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Franciotta D, Gastaldi M, Benedetti L, Pesce G, Biagioli T, Lolli F, Costa G, Melis C, Andreetta F, Simoncini O, Giannotta C, Bazzigaluppi E, Fazio R, Bedin R, Ferraro D, Mariotto S, Ferrari S, Galloni E, De Riva V, Zardini E, Cortese A, and Nobile-Orazio E
- Subjects
- Antibodies metabolism, Autoimmune Diseases of the Nervous System complications, Gangliosides immunology, Humans, Peripheral Nervous System Diseases complications, Autoimmune Diseases of the Nervous System diagnosis, Peripheral Nervous System Diseases diagnosis
- Abstract
This document presents the guidelines for anti-ganglioside antibody testing that have been developed following a consensus process built on questionnaire-based surveys, internet contacts, and discussions at workshops of the sponsoring Italian Association of Neuroimmunology (AINI) congresses. Main clinical information on dysimmune peripheral neuropathies, indications and limits of anti-ganglioside antibody testing, instructions for result interpretation, and an agreed laboratory protocol (Appendix) are reported for the communicative community of neurologists and clinical pathologists.
- Published
- 2017
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159. Evidence towards RNA Binding Motif (RNP1, RRM) Protein 3 (RBM3) as a Potential Biomarker of Lithium Response in Bipolar Disorder Patients.
- Author
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Papadima EM, Niola P, Melis C, Pisanu C, Congiu D, Cruceanu C, Lopez JP, Turecki G, Ardau R, Severino G, Chillotti C, Del Zompo M, and Squassina A
- Subjects
- Adolescent, Adult, Binding Sites, Biomarkers metabolism, Bipolar Disorder diagnosis, Bipolar Disorder drug therapy, Case-Control Studies, Cell Line, Tumor, Cells, Cultured, Female, Humans, Male, Middle Aged, Protein Binding, RNA metabolism, RNA-Binding Proteins chemistry, Antidepressive Agents therapeutic use, Bipolar Disorder metabolism, Lithium Compounds therapeutic use, RNA-Binding Proteins metabolism
- Abstract
Lithium has been used for more than six decades for the management of bipolar disorder (BD). In a previous transcriptomic study, we showed that patients affected by either BD or cluster headache, both disorders characterized by circadian disturbances and response to lithium in a subgroup of patients, have higher expression of the RNA binding motif (RNP1, RRM) protein 3 (RBM3) gene compared to controls. To investigate whether RBM3 could represent a biomarker of lithium response, we screened raw microarray expression data from lymphoblastoid cell lines (LCLs) derived from 20 BD patients, responders or non-responders to lithium. RBM3 was the most significantly differentially expressed gene in the list, being overexpressed in responders compared to non-responders (fold change = 2.0; p = 1.5 × 10
-16 ). We therefore sought to validate the microarray finding by quantitative reverse transcription polymerase chain reaction (RT-qPCR) and explore whether RBM3 expression was modulated by lithium treatment in vitro in LCLs as well as in human-derived neural progenitor cells (NPCs). Our findings confirmed the higher expression of RBM3 in responders compared to non-responders (fold change = 3.78; p = 0.0002). Lithium did not change RBM3 expression in LCLs in any of the groups, but it increased its expression in NPCs. While preliminary, our data suggest that higher levels of RBM3 might be required for better lithium response and that the expression of this gene could be modulated by lithium in a tissue-specific manner.- Published
- 2017
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160. Deciphering Molecular Mechanisms of Interface Buildup and Stability in Porous Si/Eumelanin Hybrids.
- Author
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Pinna E, Melis C, Antidormi A, Cardia R, Sechi E, Cappellini G, d'Ischia M, Colombo L, and Mula G
- Subjects
- Indoles, Oxidation-Reduction, Porosity, Melanins chemistry, Silicon chemistry
- Abstract
Porous Si/eumelanin hybrids are a novel class of organic-inorganic hybrid materials that hold considerable promise for photovoltaic applications. Current progress toward device setup is, however, hindered by photocurrent stability issues, which require a detailed understanding of the mechanisms underlying the buildup and consolidation of the eumelanin-silicon interface. Herein we report an integrated experimental and computational study aimed at probing interface stability via surface modification and eumelanin manipulation, and at modeling the organic-inorganic interface via formation of a 5,6-dihydroxyindole (DHI) tetramer and its adhesion to silicon. The results indicated that mild silicon oxidation increases photocurrent stability via enhancement of the DHI-surface interaction, and that higher oxidation states in DHI oligomers create more favorable conditions for the efficient adhesion of growing eumelanin., Competing Interests: The authors declare no conflicts of interest.
- Published
- 2017
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161. N -Acylbenzenesulfonamide Dihydro-1,3,4-oxadiazole Hybrids: Seeking Selectivity toward Carbonic Anhydrase Isoforms.
- Author
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Bianco G, Meleddu R, Distinto S, Cottiglia F, Gaspari M, Melis C, Corona A, Angius R, Angeli A, Taverna D, Alcaro S, Leitans J, Kazaks A, Tars K, Supuran CT, and Maccioni E
- Abstract
A series of N -acylbenzenesulfonamide dihydro-1,3,4-oxadiazole hybrids ( EMAC8000a-m ) was designed and synthesized with the aim to target tumor associated carbonic anhydrase (hCA) isoforms IX and XII. Most of the compounds were selective inhibitors of the tumor associated hCA XII. Moreover, resolution of EMAC8000d racemic mixture led to the isolation of the levorotatory eutomer exhibiting an increase of hCA XII inhibition potency and selectivity with respect to hCA II. Computational studies corroborated these data. Overall our data indicate that both substitution pattern and stereochemistry of dihydro-1,3,4-oxadiazole could be considered as key factors to determine activity and selectivity toward hCA isozymes. These results can provide further indication for the design and optimization of selective hCA inhibitors.
- Published
- 2017
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162. Genetic rescue of an endangered domestic animal through outcrossing with closely related breeds: A case study of the Norwegian Lundehund.
- Author
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Stronen AV, Salmela E, Baldursdóttir BK, Berg P, Espelien IS, Järvi K, Jensen H, Kristensen TN, Melis C, Manenti T, Lohi H, and Pertoldi C
- Subjects
- Animals, Animals, Domestic genetics, Breeding, Crosses, Genetic, Dogs genetics, Endangered Species
- Abstract
Genetic rescue, outcrossing with individuals from a related population, is used to augment genetic diversity in populations threatened by severe inbreeding and extinction. The endangered Norwegian Lundehund dog underwent at least two severe bottlenecks in the 1940s and 1960s that each left only five inbred dogs, and the approximately 1500 dogs remaining world-wide today appear to descend from only two individuals. The Lundehund has a high prevalence of a gastrointestinal disease, to which all remaining dogs may be predisposed. Outcrossing is currently performed with three Nordic Spitz breeds: Norwegian Buhund, Icelandic Sheepdog, and Norrbottenspets. Examination of single nucleotide polymorphism (SNP) genotypes based on 165K loci in 48 dogs from the four breeds revealed substantially lower genetic diversity for the Lundehund (HE 0.035) than for other breeds (HE 0.209-0.284). Analyses of genetic structure with > 15K linkage disequilibrium-pruned SNPs showed four distinct genetic clusters. Pairwise FST values between Lundehund and the candidate breeds were highest for Icelandic Sheepdog, followed by Buhund and Norrbottenspets. We assessed the presence of outlier loci among candidate breeds and examined flanking genome regions (1 megabase) for genes under possible selection to identify potential adaptive differences among breeds; outliers were observed in flanking regions of genes associated with key functions including the immune system, metabolism, cognition and physical development. We suggest crossbreeding with multiple breeds as the best strategy to increase genetic diversity for the Lundehund and to reduce the incidence of health problems. For this project, the three candidate breeds were first selected based on phenotypes and then subjected to genetic investigation. Because phenotypes are often paramount for domestic breed owners, such a strategy could provide a helpful approach for genetic rescue and restoration of other domestic populations at risk, by ensuring the involvement of owners, breeders and managers at the start of the project.
- Published
- 2017
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163. Simulating Energy Relaxation in Pump-Probe Vibrational Spectroscopy of Hydrogen-Bonded Liquids.
- Author
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Dettori R, Ceriotti M, Hunger J, Melis C, Colombo L, and Donadio D
- Abstract
We introduce a nonequilibrium molecular dynamics simulation approach, based on the generalized Langevin equation, to study vibrational energy relaxation in pump-probe spectroscopy. A colored noise thermostat is used to selectively excite a set of vibrational modes, leaving the other modes nearly unperturbed, to mimic the effect of a monochromatic laser pump. Energy relaxation is probed by analyzing the evolution of the system after excitation in the microcanonical ensemble, thus providing direct information about the energy redistribution paths at the molecular level and their time scale. The method is applied to hydrogen-bonded molecular liquids, specifically deuterated methanol and water, providing a robust picture of energy relaxation at the molecular scale.
- Published
- 2017
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164. Exploring the thiazole scaffold for the identification of new agents for the treatment of fluconazole resistant Candida.
- Author
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Meleddu R, Distinto S, Corona A, Maccioni E, Arridu A, Melis C, Bianco G, Matyus P, Cottiglia F, Sanna A, and De Logu A
- Subjects
- Animals, Antifungal Agents chemistry, Antifungal Agents pharmacology, Candidiasis microbiology, Chlorocebus aethiops, Drug Resistance, Fungal, Microbial Sensitivity Tests, Vero Cells, Antifungal Agents therapeutic use, Candida albicans drug effects, Candidiasis drug therapy, Fluconazole therapeutic use, Thiazoles chemistry
- Abstract
Cyclohexyliden- and 2-methylcyclohexyliden-hydrazo-4-arylthiazoles were synthesized and tested as antifungal agents. All compounds exhibited minimal inhibitory concentration (MIC) values comparable with those of fluconazole (FLC). Moreover, some compounds showed fungicidal activity at low concentration. Worth noting five out of nine compounds were active towards Candida albicans 25 FLC resistant isolated from clinical specimens. The cellular toxicity was evaluated and none of the compounds is toxic at the MIC. On the basis of our data we can conclude that these derivatives are promising agents for the treatment of resistant C. albicans.
- Published
- 2016
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165. Direct new oral anticoagulants: follow-up, guidelines and bleeding complications in general practice-a survey of Swiss general internal medicine practitioners.
- Author
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Sauter TC, Melis C, Hautz WE, Ricklin ME, and Exadaktylos AK
- Abstract
Background: The present study investigated how much Swiss general internal medicine practitioners (GPs) know about new direct oral anticoagulants (NOACs), particularly the relevant guidelines, follow-up tests, dosing adjustments, indications and complications. We conducted a paper-based survey of GPs, performed in Bern, Switzerland. Our questionnaire assessed the physicians' preference for NOACs rather than vitamin K antagonists (VKA), prevalence and choice of NOAC, clinical follow-up including follow-up blood testing, and bleeding complications., Results: 53 GPs participated in our pilot investigation. They treated 32.7% ± 19 of their patients requiring oral anticoagulation with NOACs. New patients who had started oral anticoagulation received NOACs from 49 GPs (92.5%) but most GPs would not switch patients from existing VKA therapy to NOACs. Clinical controls are scheduled by a majority of GPs (67.9%) at least every 3 months; creatinine and haemoglobin are monitored by most GPs (51 (96.2%) and 39 (73.6%), respectively). In the preceding 2 years, GPs had seen 1.9 ± 2.87 bleeding complications in patients with NOACs. 0.5 ± 0.95 (range 0-5) of these required hospital treatment., Conclusion: NOACs are broadly accepted by investigated Swiss GPs as the first choice for patients newly requiring oral anticoagulation. This was in preference to VKAs and especially if recommended by a haematologist or cardiologist. As, in our population, only about two-thirds of GPs adhere to recommendations on clinical and blood test follow-ups, further efforts to implement follow-up guidelines seem necessary. Further research in a large representative GP population is recommended; this should compare NOACs and VKAs. Bleeding complications were rare in our population and could mostly be handled without hospital admission.
- Published
- 2016
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166. Lithium Pharmacogenetics: Where Do We Stand?
- Author
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Pisanu C, Melis C, and Squassina A
- Subjects
- Animals, Antimanic Agents adverse effects, Azoles adverse effects, Azoles pharmacology, Azoles therapeutic use, Biomarkers metabolism, Bipolar Disorder genetics, Humans, Isoindoles, Lithium Compounds adverse effects, Molecular Targeted Therapy, Organoselenium Compounds adverse effects, Organoselenium Compounds pharmacology, Organoselenium Compounds therapeutic use, Pharmacogenetics, RNA, Long Noncoding genetics, Antimanic Agents therapeutic use, Bipolar Disorder drug therapy, Lithium Compounds therapeutic use
- Abstract
Preclinical Research Bipolar disorder (BPD) is a chronic and disabling psychiatric disorder with a prevalence of 0.8-1.2% in the general population. Although lithium is considered the first-line treatment, a large percentage of patients do not respond sufficiently. Moreover, lithium can induce severe side effects and has poor tolerance and a narrow therapeutic index. The genetics of lithium response has been largely investigated, but findings have so far failed to identify reliable biomarkers to predict clinical response. This has been largely determined by the highly complex phenotipic and genetic architecture of lithium response. To this regard, collaborative initiatives hold the promise to provide robust and standardized methods to disantenagle this complexity, as well as the capacity to collect large samples of patietnts, a crucial requirement to study the genetics of complex phenotypes. The International Consortium on Lithium Genetics (ConLiGen) has recently published the largest study so far on lithium response reporting significant associations for two long noncoding RNAs (lncRNAs). This result provides relevant insights into the pharmacogenetics of lithium supporting the involvement of the noncoding portion of the genome in modulating clinical response. Although a vast body of research is engaged in dissecting the genetic bases of response to lithium, the several drawbacks of lithium therapy have also stimulated multiple efforts to identify new safer treatments. A drug repurposing approach identified ebselen as a potential lithium mimetic, as it shares with lithium the ability to inhibit inositol monophosphatase. Ebselen, an antioxidant glutathione peroxidase mimetic, represents a valid and promising example of new potential therapeutic interventions for BD, but the paucity of data warrant further investigation to elucidate its potential efficacy and safety in the management of BPD. Nevertheless, findings provided by the growing field of pharmacogenomic research will ultimately lead to the identification of new molecular targets and safer treatments for BPD. Drug Dev Res 77 : 368-373, 2016. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)
- Published
- 2016
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167. A triple protostar system formed via fragmentation of a gravitationally unstable disk.
- Author
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Tobin JJ, Kratter KM, Persson MV, Looney LW, Dunham MM, Segura-Cox D, Li ZY, Chandler CJ, Sadavoy SI, Harris RJ, Melis C, and Pérez LM
- Abstract
Binary and multiple star systems are a frequent outcome of the star formation process and as a result almost half of all stars with masses similar to that of the Sun have at least one companion star. Theoretical studies indicate that there are two main pathways that can operate concurrently to form binary/multiple star systems: large-scale fragmentation of turbulent gas cores and filaments or smaller-scale fragmentation of a massive protostellar disk due to gravitational instability. Observational evidence for turbulent fragmentation on scales of more than 1,000 astronomical units has recently emerged. Previous evidence for disk fragmentation was limited to inferences based on the separations of more-evolved pre-main sequence and protostellar multiple systems. The triple protostar system L1448 IRS3B is an ideal system with which to search for evidence of disk fragmentation as it is in an early phase of the star formation process, it is likely to be less than 150,000 years old and all of the protostars in the system are separated by less than 200 astronomical units. Here we report observations of dust and molecular gas emission that reveal a disk with a spiral structure surrounding the three protostars. Two protostars near the centre of the disk are separated by 61 astronomical units and a tertiary protostar is coincident with a spiral arm in the outer disk at a separation of 183 astronomical units. The inferred mass of the central pair of protostellar objects is approximately one solar mass, while the disk surrounding the three protostars has a total mass of around 0.30 solar masses. The tertiary protostar itself has a minimum mass of about 0.085 solar masses. We demonstrate that the disk around L1448 IRS3B appears susceptible to disk fragmentation at radii between 150 and 320 astronomical units, overlapping with the location of the tertiary protostar. This is consistent with models for a protostellar disk that has recently undergone gravitational instability, spawning one or two companion stars.
- Published
- 2016
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168. Tuning the thermal conductivity of methylammonium lead halide by the molecular substructure.
- Author
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Caddeo C, Melis C, Saba MI, Filippetti A, Colombo L, and Mattoni A
- Abstract
By using state-of-the-art atomistic methods we provide an accurate estimate of thermal conductivity of methylammonium lead halide as a function of sample size and temperature, in agreement with experimental works. We show that the thermal conductivity of methylammonium lead halide is intrinsically low, due to the low sound velocity of the PbI lattice. Furthermore, by selectively analyzing the effect of different molecular degrees of freedom, we clarify the role of the molecular substructure by showing that the internal modes above 150 cm(-1) (in addition to rotations) are effective in reducing the thermal conductivity of hybrid perovskites. This analysis suggests strategies to tailor the thermal conductivity by modifying the internal structure of organic cations.
- Published
- 2016
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169. Structural and Biological Interaction of hsc-70 Protein with Phosphatidylserine in Endosomal Microautophagy.
- Author
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Morozova K, Clement CC, Kaushik S, Stiller B, Arias E, Ahmad A, Rauch JN, Chatterjee V, Melis C, Scharf B, Gestwicki JE, Cuervo AM, Zuiderweg ER, and Santambrogio L
- Subjects
- Animals, Cell Line, Endosomes chemistry, Endosomes genetics, HSC70 Heat-Shock Proteins chemistry, HSC70 Heat-Shock Proteins genetics, Intracellular Membranes chemistry, Mice, Phosphatidylserines chemistry, Phosphatidylserines genetics, Autophagy physiology, Endosomes metabolism, HSC70 Heat-Shock Proteins metabolism, Intracellular Membranes metabolism, Phosphatidylserines metabolism
- Abstract
hsc-70 (HSPA8) is a cytosolic molecular chaperone, which plays a central role in cellular proteostasis, including quality control during protein refolding and regulation of protein degradation. hsc-70 is pivotal to the process of macroautophagy, chaperone-mediated autophagy, and endosomal microautophagy. The latter requires hsc-70 interaction with negatively charged phosphatidylserine (PS) at the endosomal limiting membrane. Herein, by combining plasmon resonance, NMR spectroscopy, and amino acid mutagenesis, we mapped the C terminus of the hsc-70 LID domain as the structural interface interacting with endosomal PS, and we estimated an hsc-70/PS equilibrium dissociation constant of 4.7 ± 0.1 μm. This interaction is specific and involves a total of 4-5 lysine residues. Plasmon resonance and NMR results were further experimentally validated by hsc-70 endosomal binding experiments and endosomal microautophagy assays. The discovery of this previously unknown contact surface for hsc-70 in this work elucidates the mechanism of hsc-70 PS/membrane interaction for cytosolic cargo internalization into endosomes., (© 2016 by The American Society for Biochemistry and Molecular Biology, Inc.)
- Published
- 2016
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170. Lack of sex-specific movement patterns in an alien species at its invasion front - consequences for invasion speed.
- Author
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Herfindal I, Melis C, Åhlén PA, and Dahl F
- Abstract
Efficient targeting of actions to reduce the spread of invasive alien species relies on understanding the spatial, temporal, and individual variation of movement, in particular related to dispersal. Such patterns may differ between individuals at the invasion front compared to individuals in established and dense populations due to differences in environmental and ecological conditions such as abundance of conspecifics or sex-specific dispersal affecting the encounter rate of potential mates. We assessed seasonal and diurnal variation in movement pattern (step length and turning angle) of adult male and female raccoon dog at their invasion front in northern Sweden using data from Global Positioning System (GPS)-marked adult individuals and assessed whether male and female raccoon dog differed in their movement behavior. There were few consistent sex differences in movement. The rate of dispersal was rather similar over the months, suggesting that both male and female raccoon dog disperse during most of the year, but with higher speed during spring and summer. There were diurnal movement patterns in both sexes with more directional and faster movement during the dark hours. However, the short summer nights may limit such movement patterns, and long-distance displacement was best explained by fine-scale movement patterns from 18:00 to 05:00, rather than by movement patterns only from twilight and night. Simulation of dispersing raccoon dogs suggested a higher frequency of male-female encounters that were further away from the source population for the empirical data compared to a scenario with sex differences in movement pattern. The lack of sex differences in movement pattern at the invasion front results in an increased likelihood for reproductive events far from the source population. Animals outside the source population should be considered potential reproducing individuals, and a high effort to capture such individuals is needed throughout the year to prevent further spread.
- Published
- 2016
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171. Leukocyte telomere length positively correlates with duration of lithium treatment in bipolar disorder patients.
- Author
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Squassina A, Pisanu C, Congiu D, Caria P, Frau D, Niola P, Melis C, Baggiani G, Lopez JP, Cruceanu C, Turecki G, Severino G, Bocchetta A, Vanni R, Chillotti C, and Del Zompo M
- Subjects
- Adult, Age Factors, Bipolar Disorder genetics, Cell Line, Female, Humans, In Situ Hybridization, Fluorescence, Leukocytes drug effects, Leukocytes metabolism, Male, Middle Aged, Neural Stem Cells drug effects, Neural Stem Cells metabolism, Polymerase Chain Reaction, Sex Factors, Telomerase metabolism, Telomere Shortening drug effects, Time Factors, Antimanic Agents therapeutic use, Bipolar Disorder drug therapy, Bipolar Disorder metabolism, Lithium Compounds therapeutic use, Telomere drug effects, Telomere metabolism
- Abstract
Bipolar disorder (BD) has been suggested to be associated with accelerated aging and premature cell senescence. While findings on shorter telomeres in BD are controversial, a recent study showed that long-term lithium treatment correlates with longer telomeres in BD. In our study, we sought to investigate the correlation between leukocyte telomere length (LTL) and long-term lithium treatment in a sample of 200 BD patients characterized for lithium response. We also compared data from two different methods commonly used to measure telomere length, quantitative PCR (qPCR) and quantitative fluorescence in situ hybridization (Q-FISH). We also measured, for the first time, the effect of lithium in vitro on the expression of the telomerase gene in human-derived neural progenitor cells (NPCs). Our findings showed that LTL correlated negatively with age (p=0.0002) and was independent of sex, diagnosis, age at onset, suicidal behavior, number of mood episodes, response to lithium and use of other psychotropic medications. After correcting for age, LTL was positively correlated with lithium treatment duration in patients treated for more than two years (n=150, R=0.17, p=0.037). There was a significant correlation between data measured with qPCR and Q-FISH (p=0.012, R=0.826). Lithium treatment increased telomerase expression in NPCs, though this effect was not statistically significant. Our data support previous findings showing that long-term lithium treatment associates with longer telomeres in BD, though this effect appeared to be independent from clinical response to the treatment. Moreover, we suggested for the first time that lithium increases the expression of telomerase gene in human neural progenitor cells., (Copyright © 2016 Elsevier B.V. and ECNP. All rights reserved.)
- Published
- 2016
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172. New 4-[(3-cyclohexyl-4-aryl-2,3-dihydro-1,3-thiazol-2-ylidene)amino]benzene-1-sulfonamides, synthesis and inhibitory activity toward carbonic anhydrase I, II, IX, XII.
- Author
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Meleddu R, Maccioni E, Distinto S, Bianco G, Melis C, Alcaro S, Cottiglia F, Ceruso M, and Supuran CT
- Subjects
- Binding Sites, Carbonic Anhydrase Inhibitors chemical synthesis, Carbonic Anhydrase Inhibitors chemistry, Carbonic Anhydrase Inhibitors pharmacology, Enzyme Activation drug effects, Humans, Isoenzymes chemical synthesis, Isoenzymes chemistry, Isoenzymes pharmacology, Models, Biological, Molecular Structure, Sulfonamides chemistry, Thiazoles chemistry, Thiazoles pharmacology, Triazoles chemical synthesis, Triazoles chemistry, Triazoles pharmacology, Benzenesulfonamides, Carbonic Anhydrase I antagonists & inhibitors, Carbonic Anhydrase II antagonists & inhibitors, Carbonic Anhydrases metabolism, Sulfonamides chemical synthesis, Sulfonamides pharmacology, Thiazoles chemical synthesis
- Abstract
A series of 4-[(3-cyclohexyl-4-aryl-2,3-dihydro-1,3-thiazol-2-ylidene)amino]benzene-1-sulfonamides was synthesised and the activity of the new compounds as inhibitors of hCA I, II, IX, and XII was evaluated. These new derivatives exhibited some peculiarities with respect to previously reported sulfonamide based inhibitors of CA. We observed that the nature of the substituents in the position 3 and 4 of the dihydro-thiazole ring was relevant in determining both activity and selectivity profiles., (Copyright © 2015 Elsevier Ltd. All rights reserved.)
- Published
- 2015
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173. Molecular Genetics of Sex Identification, Breed Ancestry and Polydactyly in the Norwegian Lundehund Breed.
- Author
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Kropatsch R, Melis C, Stronen AV, Jensen H, and Epplen JT
- Subjects
- Animals, Breeding, Female, Genetic Markers, Genotype, Homozygote, Male, Microsatellite Repeats, Norway, Polymorphism, Single Nucleotide, Sequence Analysis, DNA, Sex Determination Analysis, X Chromosome genetics, Y Chromosome genetics, Dogs genetics, Genetic Variation, Inbreeding, Polydactyly genetics
- Abstract
The Norwegian Lundehund breed of dog has undergone a severe loss of genetic diversity as a result of inbreeding and epizootics of canine distemper. As a consequence, the breed is extremely homogeneous and accurate sex identification is not always possible by standard screening of X-chromosomal loci. To improve our genetic understanding of the breed we genotyped 17 individuals using a genome-wide array of 170 000 single nucleotide polymorphisms (SNPs). Standard analyses based on expected homozygosity of X-chromosomal loci failed in assigning individuals to the correct sex, as determined initially by physical examination and confirmed with the Y-chromosomal marker, amelogenin. This demonstrates that identification of sex using standard SNP assays can be erroneous in highly inbred individuals., (© The American Genetic Association 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2015
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174. Elucidating ligand binding and channel gating mechanisms in pentameric ligand-gated ion channels by atomistic simulations.
- Author
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Comitani F, Melis C, and Molteni C
- Subjects
- Computer Simulation, Ligand-Gated Ion Channels metabolism, Ligands, Models, Molecular, Molecular Dynamics Simulation, Neurons chemistry, Neurons metabolism, Receptors, GABA metabolism, Receptors, Nicotinic metabolism, Receptors, Serotonin, 5-HT3 metabolism, Synaptic Transmission, Ligand-Gated Ion Channels chemistry, Receptors, GABA chemistry, Receptors, Nicotinic chemistry, Receptors, Serotonin, 5-HT3 chemistry
- Abstract
Pentameric ligand-gated ion channels (pLGICs) are important biomolecules that mediate fast synaptic transmission. Their malfunctions are linked to serious neuronal disorders and they are major pharmaceutical targets; in invertebrates, they are involved in insecticide resistance. The complexity of pLGICs and the limited crystallographic information available prevent a detailed understanding of how they function. State-of-the-art computational techniques are therefore crucial to build an accurate picture at the atomic level of the mechanisms which drive the activation of pLGICs, complementing the available experimental data. We have used a series of simulation methods, including homology modelling, ligand-protein docking, density functional theory, molecular dynamics and metadynamics, a powerful scheme for accelerating rare events, with the guidance of mutagenesis electrophysiology experiments, to explore ligand-binding mechanisms, the effects of mutations and the potential role of a proline molecular switch for the gating of the ion channels. Results for the insect RDL receptor, the GABAC receptor, the 5-HT3 receptor and the nicotinic acetylcholine receptor will be reviewed.
- Published
- 2015
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175. Individual and temporal variation in habitat association of an alien carnivore at its invasion front.
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Melis C, Herfindal I, Dahl F, and Åhlén PA
- Subjects
- Agriculture, Animals, Female, Forests, Geographic Information Systems, Male, Seasons, Sweden, Wetlands, Ecosystem, Introduced Species, Raccoon Dogs
- Abstract
Gathering information on how invasive species utilize the habitat is important, in order to better aim actions to reduce their negative impact. We studied habitat use and selection of 55 GPS-marked raccoon dogs (30 males, 25 females) at their invasion front in Northern Sweden, with particular focus on differences between males and females, between movement states, and between seasons and times of the day. Daily movement pattern was used to classify GPS-locations into dispersing and settled. We focused on both anthropogenic and natural landscape characteristics. Since we did not have any a priori knowledge about the spatial scale of raccoon dog habitat selection, we first assessed how landscape characteristics of random points changed with distance from the GPS-location they were paired to. Because changes in habitat use became less pronounced at approximately 5 km for all variables, we focused on habitat use at two spatial scales: fine (500 m) and coarse (5 km). Habitat selection was strongest at the coarse scale, and reflected the results found for habitat use. Raccoon dogs selected agricultural areas and wetlands, lower altitudes, and shallow slopes, and avoided forests, open natural areas, and areas close to water and roads. There were no differences in habitat selection between males and females, or between movement states. This lack of sexual segregation increases the probability of encountering potential mates during dispersal, and therefore the likelihood for reproduction in new areas. The seasonal and diurnal pattern of habitat use may provide guidance for where and when to aim management efforts.
- Published
- 2015
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176. A VLBI resolution of the Pleiades distance controversy.
- Author
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Melis C, Reid MJ, Mioduszewski AJ, Stauffer JR, and Bower GC
- Abstract
Because of its proximity and its youth, the Pleiades open cluster of stars has been extensively studied and serves as a cornerstone for our understanding of the physical properties of young stars. This role is called into question by the "Pleiades distance controversy," wherein the cluster distance of 120.2 ± 1.5 parsecs (pc) as measured by the optical space astrometry mission Hipparcos is significantly different from the distance of 133.5 ± 1.2 pc derived with other techniques. We present an absolute trigonometric parallax distance measurement to the Pleiades cluster that uses very long baseline radio interferometry (VLBI). This distance of 136.2 ± 1.2 pc is the most accurate and precise yet presented for the cluster and is incompatible with the Hipparcos distance determination. Our results cement existing astrophysical models for Pleiades-age stars., (Copyright © 2014, American Association for the Advancement of Science.)
- Published
- 2014
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177. Quantification of the impact of single and multiple mild stresses on outgrowth heterogeneity of Bacillus cereus spores.
- Author
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van Melis CC, den Besten HM, Nierop Groot MN, and Abee T
- Subjects
- Hydrogen-Ion Concentration, Spores, Bacterial drug effects, Spores, Bacterial growth & development, Stress, Physiological, Bacillus cereus drug effects, Bacillus cereus growth & development, Hot Temperature, Sodium Chloride pharmacology, Sorbic Acid pharmacology
- Abstract
Outgrowth heterogeneity of bacterial spore populations complicates both prediction and efficient control of spore outgrowth. In this study, the impact of mild preservation stresses on outgrowth of Bacillus cereus ATCC 14579 spores was quantified during the first stages of outgrowth. Heterogeneity in outgrowth of heat-treated (90°C for 10 min) and non-heat-treated germinated single spores to the maximum micro-colony stage of 256 cells was assessed by direct imaging on Anopore strips, placed on BHI plates at pH7 and pH5.5, without and with added NaCl or sorbic acid (HSA). At pH7 non-heated and heat-treated germinated spores required 6h to reach the maximum microcolony stage with limited heterogeneity, and these parameters were only slightly affected with both types of spores when incubated at pH7 with added NaCl. Notably, the most pronounced effects were observed during outgrowth of spores at pH5.5 without and with added NaCl or HSA. Non-heat-treated germinated spores showed again efficient outgrowth with limited heterogeneity reaching the maximum microcolony stage after 6h at pH5.5, which increased to 12h and 16 h with added NaCl and HSA, respectively. In contrast, heat-treated spores displayed a strong delay between initial germination and swelling and further outgrowth at pH5.5, resulting in large heterogeneity and low numbers of fastest growers reaching the maximum microcolony stage after 10, 12 and 24h, without and with added NaCl or HSA, respectively. This work shows that Anopore technology provides quantitative information on the impact of combined preservation stresses on outgrowth of single spores, showing that outgrowth of germinated heat-treated spores is significantly affected at pH5.5 with a large fraction of spores arrested in the early outgrowth stage, and with outgrowing cells showing large heterogeneity with only a small fraction committed to relatively fast outgrowth., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
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178. Lattice thermal conductivity of Si(1-x)Ge(x) nanocomposites.
- Author
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Melis C and Colombo L
- Abstract
We calculate the lattice thermal conductivity in model Si(1-x)Ge(x) nanocomposites by molecular dynamics in a transient thermal conduction regime. Our simulations provide evidence that thermal transport depends only marginally on stoichiometry in the range 0.2≤x≤0.8, while it is deeply affected by the granulometry. In particular, we show that Si(1-x)Ge(x) nanocomposites have lattice thermal conductivity below the corresponding bulk alloy with the same stoichiometry. The main role in affecting thermal conduction is provided by grain boundaries, which largely affect vibrational modes with a long mean-free path.
- Published
- 2014
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179. Low neutral genetic variability in a specialist puffin hunter: the Norwegian Lundehund.
- Author
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Melis C, Borg ÅA, Espelien IS, and Jensen H
- Subjects
- Alleles, Animals, Breeding, Cluster Analysis, DNA genetics, Genetic Loci, Norway, Phylogeography, Dogs genetics, Genetic Variation, Microsatellite Repeats
- Abstract
The genetic variability of 125 Norwegian Lundehund and 27 Nova Scotia Duck Tolling Retriever was analysed using a set of 26 microsatellite markers. In Lundehund, the average number of alleles per locus was 1.73, and average observed (H(O)) and expected (H(E)) heterozygosity were 0.07. In Toller, all measures of genetic diversity were much higher than in Lundehund and similar to studies on other dog breeds. The cluster analysis correctly assigned individuals to their respective breed. The low genetic variability in Lundehund was not surprising, given the two strong bottlenecks in the 1940s and the 1960s. The relatedness of Lundehund to other Nordic small spitzes should be investigated in the view of possible outcrossing., (© 2012 The Authors, Animal Genetics © 2012 Stichting International Foundation for Animal Genetics.)
- Published
- 2013
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180. The anterior cingulate cortex: an integrative hub for human socially-driven interactions.
- Author
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Lavin C, Melis C, Mikulan E, Gelormini C, Huepe D, and Ibañez A
- Published
- 2013
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181. Interaction between HLA-DRB1-DQB1 haplotypes in Sardinian multiple sclerosis population.
- Author
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Cocco E, Murru R, Costa G, Kumar A, Pieroni E, Melis C, Barberini L, Sardu C, Lorefice L, Fenu G, Frau J, Coghe G, Carboni N, and Marrosu MG
- Subjects
- Antigen Presentation genetics, Case-Control Studies, Female, Genetic Predisposition to Disease genetics, HLA-DQ beta-Chains chemistry, HLA-DRB1 Chains chemistry, Humans, Italy, Male, Models, Molecular, Models, Statistical, Multiple Sclerosis immunology, Protein Conformation, Sequence Alignment, HLA-DQ beta-Chains genetics, HLA-DRB1 Chains genetics, Haplotypes genetics, Multiple Sclerosis genetics
- Abstract
We performed a case-control study in 2,555 multiple sclerosis (MS) Sardinian patients and 1,365 healthy ethnically matched controls, analyzing the interactions between HLA-DRB1-DQB1 haplotypes and defining a rank of genotypes conferring a variable degree of risk to the disease. Four haplotypes were found to confer susceptibility (*13:03-*03:01 OR = 3.3, Pc 5.1 × 10(-5), *04:05-*03:01 OR = 2.1, Pc 9.7 × 10(-8), *15:01-*06:02 OR = 2.0, Pc = 9.1 × 10(-3), *03:01-*02:01 OR = 1.7 Pc = 7.9 × 10(-22)) and protection (*11, OR = 0.8, Pc = 2.7 × 10(-2), *16:01-*05:02 OR = 0.6, Pc = 4.8 × 10(-16), *14:01-4-*05:031 = OR = 0.5, Pc = 9.8 × 10(-4) and *15:02-*06:01 OR = 0.4, Pc = 5.1 × 10(-4)). The relative predispositional effect method confirms all the positively associated haplotypes and showed that also *08 and *04 haplotypes confers susceptibility, while the *11 was excluded as protective haplotype. Genotypic ORs highlighted two typologies of interaction between haplotypes: i) a neutral interaction, in which the global risk is coherent with the sum of the single haplotype risks; ii) a negative interaction, in which the genotypic OR observed is lower than the sum of the OR of the two haplotypes. The phylogenic tree of the MS-associated DRB1 alleles found in Sardinian patients revealed a cluster represented by *14:01, *04:05, *13∶03, *08:01 and *03:01 alleles. Sequence alignment analysis showed that amino acids near pocket P4 and pocket P9 differentiated protective from predisposing alleles under investigation. Furthermore, molecular dynamics simulation performed on alleles revealed that position 70 is crucial in binding of MBP 85-99 peptide. All together, these data suggest that propensity to MS observed in Sardinian population carried by the various HLA-DRB1-DQB1 molecules can be due to functional peculiarity in the antigen presentation mechanisms.
- Published
- 2013
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182. Genetic variability and structure of the water vole Arvicola amphibius across four metapopulations in northern Norway.
- Author
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Melis C, Borg AA, Jensen H, Bjørkvoll E, Ringsby TH, and Sæther BE
- Abstract
Water vole Arvicola amphibius populations have recently experienced severe decline in several European countries as a consequence of both reduction in suitable habitat and the establishment of the alien predator American mink Neovison vison. We used DNA microsatellite markers to describe the genetic structure of 14 island populations of water vole off the coast of northern Norway. We looked at intra- and inter-population levels of genetic variation and examined the effect of distance among pairs of populations on genetic differentiation (isolation by distance). We found a high level of genetic differentiation (measured by F ST) among populations overall as well as between all pairs of populations. The genetic differentiation between populations was positively correlated with geographic distance between them. A clustering analysis grouped individuals into 7 distinct clusters and showed the presence of 3 immigrants among them. Our results suggest a small geographic scale for evolutionary and population dynamic processes in our water vole populations.
- Published
- 2013
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183. Germination inhibition of Bacillus cereus spores: impact of the lipophilic character of inhibiting compounds.
- Author
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van Melis CC, Almeida CB, Kort R, Groot MN, and Abee T
- Subjects
- Acids metabolism, Alcohols metabolism, Bacillus cereus drug effects, Bacillus cereus physiology, Hydrogen-Ion Concentration, Picolinic Acids metabolism, Spores, Bacterial drug effects, Spores, Bacterial physiology, Food Microbiology
- Abstract
In this study, the impact of a range of organic acids and structurally similar alcohols with three to six carbon backbones and increasing lipophilic character, were tested on the germination behavior of B. cereus ATCC 14579 spores. This approach allowed substantiating whether the effectivity of the various compounds was largely dictated by membrane interference or a classic weak acid acidification effect. The octanol-water partition coefficient (log P(oct/water)) ranges from 0.25/0.33 to 2.03/1.96 for propanol/undissociated propionic acid and hexanol/undissociated hexanoic acid, respectively. Performance of germination assays at neutral (pH7) and acidic conditions (pH5.5) allowed for a comparative analysis of the action of dissociated versus undissociated acids, and the presumed pH-independent effect of the corresponding alcohols. Germination assays, based on both continuously measured optical density and time-based plating experiments, and microscopic observations demonstrated the correlation between the lipophilic character of the selected compounds and their inhibiting effect on spore germination. Real-time fluorescence based assays showed that membrane integrity in dormant spores was maintained in the presence of the tested inhibitors. Lowering the critical concentration of inhibitors by a one-step washing procedure resulted in the onset of nutrient-induced germination, indicating the reversible nature of the inhibition process. Furthermore, blocking of nutrient-induced germination in the presence of inhibitory concentrations of selected lipophilic acids and corresponding alcohols was by-passed upon addition of Ca-dipicolinic acid, pointing to loss of signaling capacity in germinant receptor-mediated germination activity. These findings show that lipophilicity is an important determinant for the ability of the selected acids and corresponding alcohols to accumulate in the spore inner membrane and their ability to act as a germination-inhibitor., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2012
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184. Rapid disappearance of a warm, dusty circumstellar disk.
- Author
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Melis C, Zuckerman B, Rhee JH, Song I, Murphy SJ, and Bessell MS
- Abstract
Stars form with gaseous and dusty circumstellar envelopes, which rapidly settle into disks that eventually give rise to planetary systems. Understanding the process by which these disks evolve is paramount in developing an accurate theory of planet formation that can account for the variety of planetary systems discovered so far. The formation of Earth-like planets through collisional accumulation of rocky objects within a disk has mainly been explored in theoretical and computational work in which post-collision ejecta evolution typically is ignored, although recent work has considered the fate of such material. Here we report observations of a young, Sun-like star (TYC 8241 2652 1) where infrared flux from post-collisional ejecta has decreased drastically, by a factor of about 30, over a period of less than two years. The star seems to have gone from hosting substantial quantities of dusty ejecta, in a region analogous to where the rocky planets orbit in the Solar System, to retaining at most a meagre amount of cooler dust. Such a phase of rapid ejecta evolution has not been previously predicted or observed, and no currently available physical model satisfactorily explains the observations.
- Published
- 2012
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185. Self-assembling of zinc phthalocyanines on ZnO (1010) surface through multiple time scales.
- Author
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Melis C, Raiteri P, Colombo L, and Mattoni A
- Subjects
- Computer Simulation, Isoindoles, Macromolecular Substances chemistry, Molecular Conformation, Particle Size, Surface Properties, Zinc Compounds, Indoles chemistry, Models, Chemical, Models, Molecular, Nanostructures chemistry, Nanostructures ultrastructure, Organometallic Compounds chemistry, Zinc Oxide chemistry
- Abstract
We adopt a hierarchic combination of theoretical methods to study the assembling of zinc phthalocyanines (ZnPcs) on a ZnO (1010) surface through multiple time scales. Atomistic simulations, such as model potential molecular dynamics and metadynamics, are used to study the energetics and short time evolution (up to ∼100 ns) of small ZnPc aggregates. The stability and the lifetime of large clusters is then studied by means of an atomistically informed coarse-grained model using classical molecular dynamics. Finally, the macroscopic time scale clustering phenomenon is studied by Metropolis Monte Carlo algorithms as a function of temperature and surface coverage. We provide evidence that at room temperature the aggregation is likely to occur at sufficiently high coverage, and we characterize the nature, morphology, and lifetime of ZnPc's clusters. We identify the molecular stripes oriented along [010] crystallographic directions as the most energetically stable aggregates.
- Published
- 2011
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186. Characterization of germination and outgrowth of sorbic acid-stressed Bacillus cereus ATCC 14579 spores: phenotype and transcriptome analysis.
- Author
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van Melis CC, Nierop Groot MN, Tempelaars MH, Moezelaar R, and Abee T
- Subjects
- Bacterial Proteins genetics, Bacterial Proteins metabolism, Culture Media, Dose-Response Relationship, Drug, Flow Cytometry, Food Contamination analysis, Food Contamination prevention & control, Gene Expression Profiling, Hydrogen-Ion Concentration, Microarray Analysis, Phenotype, Species Specificity, Spores, Bacterial genetics, Spores, Bacterial growth & development, Spores, Bacterial metabolism, Bacillus cereus drug effects, Bacillus cereus physiology, Food Microbiology, Sorbic Acid pharmacology
- Abstract
Sorbic acid (SA) is widely used as a preservative, but the effect of SA on spore germination and outgrowth has gained limited attention up to now. Therefore, the effect of sorbic acid on germination of spores of Bacillus cereus strain ATCC 14579 was analyzed both at phenotype and transcriptome level. Spore germination and outgrowth were assessed at pH 5.5 without and with 0.75, 1.5 and 3.0 mM (final concentrations) undissociated sorbic acid (HSA). This resulted in distinct HSA concentration-dependent phenotypes, varying from reduced germination and outgrowth rates to complete blockage of germination at 3.0 mM HSA. The phenotypes reflecting different stages in the germination process could be confirmed using flow cytometry and could be recognized at transcriptome level by distinct expression profiles. In the absence and presence of 0.75 and 1.5 mM HSA, similar cellular ATP levels were found up to the initial stage of outgrowth, suggesting that HSA-induced inhibition of outgrowth is not caused by depletion of ATP. Transcriptome analysis revealed the presence of a limited number of transcripts in dormant spores, outgrowth related expression, and genes specifically associated with sorbic acid stress, including alterations in cell envelope and multidrug resistance. The potential role of these HSA-stress associated genes in spore outgrowth is discussed., (Copyright © 2010 Elsevier Ltd. All rights reserved.)
- Published
- 2011
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187. Rapid desensitization of the rat α7 nAChR is facilitated by the presence of a proline residue in the outer β-sheet.
- Author
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McCormack TJ, Melis C, Colón J, Gay EA, Mike A, Karoly R, Lamb PW, Molteni C, and Yakel JL
- Subjects
- Amino Acid Sequence, Animals, CHO Cells, Chick Embryo, Cricetinae, Cricetulus, Crystallography, X-Ray, Female, Ion Channel Gating genetics, Molecular Sequence Data, Mutation, Protein Structure, Secondary, Rats, Time Factors, Xenopus laevis, alpha7 Nicotinic Acetylcholine Receptor, Proline chemistry, Proline genetics, Receptors, Nicotinic chemistry, Receptors, Nicotinic genetics
- Abstract
The rat α7 nicotinic acetylcholine receptor (nAChR) has a proline residue near the middle of the β9 strand. The replacement of this proline residue at position 180 (P180) by either threonine (α7-P180T) or serine (α7-P180S) slowed the onset of desensitization dramatically, with half-times of ~930 and 700 ms, respectively, compared to 90 ms for the wild-type receptor. To investigate the importance of the hydroxyl group on the position 180 side-chains, the mutant receptors α7-P180Y and α7-P180F were studied and showed half-times of desensitization of 650 and 160 ms, respectively. While a position 180 side-chain OH group may contribute to the slow desensitization rates, α7-P180S and α7-P180V resulted in receptors with similar desensitization rates, suggesting that increased backbone to backbone H bonding expected in the absence of proline at position 180 would likely exert a great effect on desensitization. Single channel recordings indicated that for the α7-P180T receptor there was a significantly reduced closed time without any change in single channel conductance (as compared to wild-type). Kinetic simulations indicated that all changes observed for the mutant channel behaviour were reproduced by decreasing the rate of desensitization, and increasing the microscopic affinity to resting receptors. Molecular dynamics (MD) simulations on a homology model were used to provide insight into likely H bond interactions within the outer β-sheet that occur when the P180 residue is mutated. All mutations analysed increased about twofold the predicted number of H bonds between the residue at position 180 and the backbone of the β10 strand. Moreover, the α7-P180T and α7-P180S mutations also formed some intrastrand H bonds along the β9 strand, although H bonding of the OH groups of the threonine or serine side-chains was predicted to be infrequent. Our results indicate that rapid desensitization of the wild-type rat α7 nAChR is facilitated by the presence of the proline residue within the β9 strand.
- Published
- 2010
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188. Trans-cis switching mechanisms in proline analogues and their relevance for the gating of the 5-HT3 receptor.
- Author
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Melis C, Bussi G, Lummis SC, and Molteni C
- Subjects
- Algorithms, Computer Simulation, Ligands, Models, Chemical, Models, Molecular, Molecular Conformation, Mutagenesis, Mutation, Peptides chemistry, Software, Thermodynamics, Water chemistry, Biophysics methods, Proline chemistry, Receptors, Serotonin, 5-HT3 chemistry
- Abstract
Trans-cis isomerization of a proline peptide bond is a potential mechanism to open the channel of the 5-HT(3) receptor. Here, we have used the metadynamics method to theoretically explore such a mechanism. We have determined the free energy surfaces in aqueous solution of a series of dipeptides of proline analogues and evaluated the free energy difference between the cis and trans isomers. These theoretical results were then compared with data from mutagenesis experiments, in which the response of the 5-HT(3) receptor was measured when the proline at the apex of the M2-M3 transmembrane domain loop was mutated. The strong correlation between the experimental and the theoretical data supports the existence of a trans-cis proline switch for opening the 5-HT(3) receptor ion channel.
- Published
- 2009
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189. Variation within the CLEC16A gene shows consistent disease association with both multiple sclerosis and type 1 diabetes in Sardinia.
- Author
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Zoledziewska M, Costa G, Pitzalis M, Cocco E, Melis C, Moi L, Zavattari P, Murru R, Lampis R, Morelli L, Poddie F, Frongia P, Pusceddu P, Bajorek M, Marras A, Satta AM, Chessa A, Pugliatti M, Sotgiu S, Whalen MB, Rosati G, Cucca F, and Marrosu MG
- Subjects
- Adult, Age of Onset, Alleles, Case-Control Studies, Family, Female, Humans, Italy, Male, Odds Ratio, Polymorphism, Genetic, Probability, Diabetes Mellitus, Type 1 genetics, Genetic Variation, Genome-Wide Association Study, Lectins, C-Type genetics, Monosaccharide Transport Proteins genetics, Multiple Sclerosis genetics
- Abstract
Variation within intron 19 of the CLEC16A (KIAA0350) gene region was recently found to be unequivocally associated with type 1 diabetes (T1D) in genome-wide association (GWA) studies in Northern European populations. A variant in intron 22 that is nearly independent of the intron 19 variant showed suggestive evidence of association with multiple sclerosis (MS). Here, we genotyped the rs725613 polymorphism, representative of the earlier reported associations with T1D within CLEC16A, in 1037 T1D cases, 1498 MS cases and 1706 matched controls, all from the founder, autoimmunity-prone Sardinian population. In these Sardinian samples, allele A of rs725613 is positively associated not only with T1D (odds ratio=1.15, P one-tail=5.1 x 10(-3)) but also, and with a comparable effect size, with MS (odds ratio=1.21, P one-tail 6.7 x 10(-5)). Taken together these data provide evidence of joint disease association in T1D and MS within CLEC16A and underline a shared disease pathway.
- Published
- 2009
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190. Molecular dynamics simulations of GABA binding to the GABAC receptor: the role of Arg104.
- Author
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Melis C, Lummis SC, and Molteni C
- Subjects
- Amino Acid Sequence, Catalytic Domain, Extracellular Space metabolism, Molecular Sequence Data, Mutagenesis, Mutant Proteins chemistry, Mutant Proteins genetics, Mutant Proteins metabolism, Mutation, Protein Binding, Protein Structure, Tertiary, Receptors, GABA genetics, Reproducibility of Results, Sequence Homology, Amino Acid, Water metabolism, Arginine metabolism, Models, Molecular, Receptors, GABA chemistry, Receptors, GABA metabolism, gamma-Aminobutyric Acid metabolism
- Abstract
GABA is the major inhibitory neurotransmitter in the nervous system and acts at a variety of receptors including GABAC receptors, which are a subclass of GABAA receptors. Here we have used molecular dynamics simulations of GABA docked into the extracellular domain of the GABAC receptor to explain the molecular interactions of the neurotransmitter with the residues that contribute to the binding site; in particular, we have explored the interaction of GABA with Arg104. The simulations suggest that the amine group of GABA forms cation-pi interactions with Tyr102 and Tyr198, and hydrogen-bonds with Gln83, Glu220, Ser243, and Ser168, and, most prominently, with Arg104. Substituting Arg104 with Ala, Glu, or Lys, which experimentally disrupt GABAC receptor function, and repeating the simulation revealed fewer and different bonding patterns with GABA, or the rapid exit of GABA from the binding pocket. The simulations therefore unveil interactions of GABA within the binding pocket, and explain experimental data, which indicate that Arg104 is critical for the efficient functioning of the receptor.
- Published
- 2008
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191. A decomposition of electrocortical activity as a function of spatial frequency: a weighted multidimensional scaling analysis.
- Author
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Melis C, Baas JM, Kenemans JL, and Mangun GR
- Subjects
- Adolescent, Adult, Analysis of Variance, Electrodes, Female, Humans, Male, Pattern Recognition, Visual, Photic Stimulation methods, Reaction Time physiology, Visual Fields, Brain physiology, Brain Mapping, Electroencephalography methods, Evoked Potentials, Visual physiology, Space Perception physiology, Weights and Measures
- Abstract
In this study, we examined the usefulness of weighted multidimensional scaling (WMDS) to decompose electrocortical activity of multiple brain sources. This electrocortical activity was evoked by checkerboard stimuli of four different spatial frequencies (0.75, 1.5, 3.0, and 6.0 cpd), presented to 12 participants under passive viewing conditions. Visual evoked potentials (VEPs) were recorded with a high density montage of 60 electrodes. These data were analyzed by using WMDS, resulting in four different dimensions, each of which can be considered equivalent to a potential scalp distribution, i.e. dipole source. The first of these dipole sources, which were determined by brain electrical source analysis (BESA), was predominantly activated by higher spatial frequencies, the second and third were predominantly activated by lower spatial frequencies, while the third and fourth sources were characterized by hemispheric asymmetry. Moreover, the neural activity of these brain sources was characterized by different patterns as a function of spatial frequency and time. The results suggest that visual processing of spatial frequencies comprises relatively separate subsystems with different spatiotemporal response characteristics.
- Published
- 2008
- Full Text
- View/download PDF
192. Exploring the binding of serotonin to the 5-HT3 receptor by density functional theory.
- Author
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Melis C, Chau PL, Price KL, Lummis SC, and Molteni C
- Subjects
- Amino Acid Substitution, Hydrogen Bonding, Models, Molecular, Protein Binding, Receptors, Serotonin, 5-HT3 chemistry, Receptors, Serotonin, 5-HT3 metabolism, Tyrosine chemistry
- Abstract
The 5-HT3 receptor is a typical ligand-gated ion channel of the Cys-loop superfamily, which is activated by binding of serotonin (5-HT). Models of the binding site of this protein reveal potential interactions between 5-HT and Tyr143, Tyr153, and Tyr234. Here we describe a series of ab initio calculations, based on density functional theory, to assess the effects of mutating these tyrosine residues on the binding of 5-HT. A series of mutations to these tyrosines, previously studied experimentally, were tested, and the binding energies compared with the available experimental data. Our results show that Tyr153 could form a hydrogen bond with the tertiary amine of 5-HT, and that mutation in this location revealed binding energies broadly in line with experimentally determined EC50s. Tyr143 could also form a hydrogen bond, but as EC50s do not relate to binding energies, it is unlikely that such a bond is formed here. Tyr234 is quite distinct in that it may interact with 5-HT via a mixed hydrogen bond/cation-pi interaction.
- Published
- 2006
- Full Text
- View/download PDF
193. PTPRC (CD45) C77G mutation does not contribute to multiple sclerosis susceptibility in Sardinian patients.
- Author
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Cocco E, Murru MR, Melis C, Schirru L, Solla E, Lai M, Rolesu M, and Marrosu MG
- Subjects
- Alleles, Chi-Square Distribution, Cytosine, Female, Gene Frequency genetics, Guanine, Humans, Intracellular Signaling Peptides and Proteins, Italy, Male, Genetic Predisposition to Disease, Leukocyte Common Antigens genetics, Membrane Proteins genetics, Multiple Sclerosis genetics, Phosphoproteins genetics, Point Mutation
- Abstract
A linkage and association of the CD45 (protein-tyrosine phosphatase, receptor-type C) C77G polymorphism and multiple sclerosis (MS) has been found in some studies but not in others. We analysed the C77G polymorphism in MS patients from the genetically homogeneous population of Sardinia. Using the transmission disequilibrium test, the mutation has been sought in 241 patients and 217 healthy sibs (HS) from singleton MS families and it was found in 5 (2.07 %) affected and 3 (1.38%) HS from 7 heterozygous parents (1.45 %). Transmission of the G77 allele was 71.4 % (TDT = 1.3, P = 0.26) in patients and 50% (TDT = 0, P = 1) in HS. Stratifying families according to carriage of MS-predisposing (DR+) or not-predisposing (DR-) HLA-DR-DQ genotype in patients, percentage of G77 transmission to DR+ patients was 33 (TDT = 0.33, P = 0.56, Pc = 1.12), while it was 100 (TDT = 4, P = 0.045, Pc = 0.09) in the DR-patients. We concluded that, despite the presence of CD45 G77 polymorphism in a few patients who did not carry the HLADR- DQ MS-predisposing molecules, CD45 did not contribute to development of the disease in Sardinian MS.
- Published
- 2004
- Full Text
- View/download PDF
194. Dissection of the HLA association with multiple sclerosis in the founder isolated population of Sardinia.
- Author
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Marrosu MG, Murru R, Murru MR, Costa G, Zavattari P, Whalen M, Cocco E, Mancosu C, Schirru L, Solla E, Fadda E, Melis C, Porru I, Rolesu M, and Cucca F
- Subjects
- Adolescent, Adult, Aged, Alleles, Child, Female, Founder Effect, Genetic Variation, HLA-DP beta-Chains, HLA-DQ beta-Chains, HLA-DRB1 Chains, Humans, Italy, Linkage Disequilibrium, Male, Microsatellite Repeats, Middle Aged, Chromosomes, Human, Pair 6 genetics, HLA-DP Antigens genetics, HLA-DQ Antigens genetics, HLA-DR Antigens genetics, Multiple Sclerosis genetics
- Abstract
Several studies have indicated that multiple sclerosis (MS) is associated and linked to the major histocompatibility complex (MHC)/human leukocyte antigen (HLA) region of chromosome 6p21.3, but the exact location and nature of the primarily associated locus within the HLA complex is still controversial and largely presumptive. By linkage disequilibrium mapping, we have systematically investigated this chromosome region in the founder population of Sardinia to determine the relative associations of the various loci with MS. An overall 11.4 Mb region, which encompasses the whole HLA complex, was scanned with 19 microsatellite markers and with single nucleotide polymorphisms within 12 functional candidate genes and assessed for MS association using the extended transmission disequilibrium test (ETDT). A peak of association represented by the three adjacent DRB1, -DQA1 and -DQB1 loci was detected in the class II region. Two additional less significant areas of association were detected, respectively, in the centromeric side of the class II region at the DPB1 locus and, telomeric of the classically defined class I loci, at the D6S1683 microsatellite. Conditional ETDT analysis indicated that these regions of association could be independent of each other. Within the main peak of association, DRB1 and DQB1 contribute to the disease association independently of each other whereas DQA1 had no detectable primary genetic effects. We evaluated the haplotype distribution at the region showing the strongest association and found five DQB1-DRB1 haplotypes positively associated with MS in Sardinia. These consistently included all the haplotypes previously found associated with MS in the various human populations, thus supporting a primary effect of the products of these loci in MS. Overall these results are consistent with a multilocus model of the MHC encoded susceptibility to MS.
- Published
- 2001
- Full Text
- View/download PDF
195. High-resolution analysis of IL-6 minisatellite polymorphism in Sardinian multiple sclerosis: effect on course and onset of disease.
- Author
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Vandenbroeck K, Fiten P, Ronsse I, Goris A, Porru I, Melis C, Rolesu M, Billiau A, Marrosu MG, and Opdenakker G
- Subjects
- Adult, Age of Onset, Alleles, Female, Genotype, Humans, Italy, Male, Prognosis, Interleukin-6 genetics, Minisatellite Repeats, Multiple Sclerosis genetics, Polymorphism, Genetic
- Abstract
A minisatellite polymorphism located in the 3' flanking region of the interleukin-6 (IL-6) gene was analysed in 192 Sardinian simplex families with multiple sclerosis (MS). By applying a high-resolution sizing approach, 9 alleles were identified. None of these were associated with in globo susceptibility to MS as shown by transmission disequilibrium testing. Analysis of clinically different groups showed that the A5 allele was associated with a benign (P = 0.007) but not with a malignant (P = 0.45) course of disease. In particular, the frequency of the A5/A5 genotype was significantly higher in patients with benign MS (P = 0.002). In addition, carriage of any of the larger alleles (A6-->A9) was associated with accelerated onset of disease (P = 0.025). Our results suggest that allelic variations in the IL-6 gene may predispose to alterations in the course and initial onset of MS.
- Published
- 2000
- Full Text
- View/download PDF
196. Visual stimulus change and the orienting reaction: event-related potential evidence for a two-stage process.
- Author
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Kenemans JL, Verbaten MN, Melis CJ, and Slangen JL
- Subjects
- Adult, Electroencephalography, Female, Humans, Male, Task Performance and Analysis, Evoked Potentials physiology, Orientation physiology, Photic Stimulation
- Abstract
In a previous study it was found that infrequent deviant visual stimuli, in a series of standards, elicited event-related potentials (ERPs) with enhanced P2-N2s and P3 amplitudes, suggesting that these parameters reflect processes related to the orienting reaction (OR). In the present study a similar oddball series was presented against the background of a second class of stimuli. With respect to the latter stimuli, subjects had to perform either a very involved (hard) or an easy task. EEG was recorded to oddball (probe) stimuli from Oz, Pz, Cz, and Fz. Analysis of average ERPs revealed that, in the easy condition, deviant probes elicited both enhanced P2-N2s and enhanced P3s, relative to the standards. In contrast, in the hard condition P2-N2, but not P3, was enhanced by stimulus change. In addition, overall P3 amplitude to probes was smaller in the hard condition (sequence-independent load effect). Analysis of single-trial ERPs (SERPs) with orthogonal polynomial trend analysis largely replicated these effects. In addition, SERP analysis also revealed a sequence-independent load effect on P2, as well as a decreasing P3 to deviant stimuli in the Easy condition, which was observed at Cz and Fz, but not at Pz or Oz. The results are interpreted as suggesting that P2-N2 and P3 reflect different stages of the OR, one of automatic and one of capacity-limited processing.
- Published
- 1992
- Full Text
- View/download PDF
197. [Lewis antigen and diabetes].
- Author
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Melis C, Mercier P, Vague P, and Vialettes B
- Subjects
- ABO Blood-Group System, Diabetes Mellitus genetics, Diabetes Mellitus, Type 1 blood, Diabetes Mellitus, Type 1 genetics, Erythrocytes analysis, Gene Frequency, Humans, Phenotype, Racial Groups, Saliva analysis, Diabetes Mellitus blood, Lewis Blood Group Antigens
- Abstract
The Lewis negative (Le a--b--) red blood cell phenotype was observed three times more frequently in 170 diabetics (29%) irrespective of their clinical type and in 27 non-diabetics low insulin responders to glucose than in 100 controls (10%). This difference could not be accounted for by factors influencing the serological typing ("ABH secretion and ABO groups) nor by the geographic origin of the populations tested. The Lewis substances are primarly soluble antigens present in blood, saliva, others fluids and absorbed on red blood cells. In 50 diabetics saliva was also analysed. Blood cell and saliva results were concordant allowing to interpret the Lewis negative blood cell phenotype as reflecting the absence of Lewis antigen. The higher frequency of Lewis negative phenotype was not related to the severity or the duration of the diabetes and therefore was unlikely to depend on metabolic factors. The similarity between the results for juvenile and maturity onset diabetes seems to indicate that these two clinical types of diabetes are genetically related. Furthermore, the same results obtained in low insulin responders afford additional support for considering these subjects as potential diabetics. It probably indicates, in the diabetic population, an increased frequency of le/le genotype or of one or several genes inhibiting the expression of Le.
- Published
- 1978
- Full Text
- View/download PDF
198. [Hemogram and pretransfusion verification of blood group. Effects of the presence of cold agglutinins].
- Author
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Perroud A, Deveze JL, Mas JC, Vadon D, Melis C, and Bex JP
- Subjects
- Cryoglobulins, Humans, Male, Middle Aged, Agglutinins analysis, Blood Cell Count, Blood Grouping and Crossmatching
- Published
- 1981
199. [Irregular agglutinins, hemolysins, antilymphocyte antibodies, serum anticomplementarity, human and species antiglobulins and cryoglobulins in a series of 33 patients with rheumatoid arthritis].
- Author
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Mercier P, Roux H, Maestracci D, Melis C, and Recordier AM
- Subjects
- Agglutinins analysis, Animals, Antibodies, Anti-Idiotypic analysis, Arthritis, Rheumatoid diagnosis, Autoantibodies analysis, Complement System Proteins, Coombs Test, Cryoglobulins analysis, Cytotoxicity Tests, Immunologic, Erythrocytes immunology, Female, HLA Antigens, Hemolysin Proteins analysis, Humans, Immune Adherence Reaction, Immunodiffusion, Lymphocytes immunology, Lymphotoxin-alpha analysis, Male, Rheumatoid Factor analysis, Species Specificity, Arthritis, Rheumatoid immunology
- Abstract
An immunological investigation was carried out on 33 rheumatoid polyarthritis patients. The phenomena of antierythrocytes immunization were investigated by standard tests : irregular agglutinins, haemolysins, and auto-antibodies which all proved negative. The lymphocyte immunological phenomena were also studied. Cold (4 degrees C) lymphocytotoxins were shown in 8 patients, 5 of whom had anti-lymphocyte auto-antibodies. The proportions of "sheep rosettes" were significantly reduced. The sera did not show notable anti-complementary activity. Studies on the human antiglobulins and on species antiglobulins were not very conclusive. Cryoglobulins were never detected. No clear correlation was found between these different tests and those of standard rheumatism serology.
- Published
- 1975
200. [14 cases of "anti-N" antibodies in hemodialysis patients in Marseille].
- Author
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Melis C and Battaglini P
- Subjects
- ABO Blood-Group System, Age Factors, Agglutinins analysis, Autoantibodies analysis, Formaldehyde adverse effects, Humans, Sex Factors, Time Factors, Isoantibodies analysis, MNSs Blood-Group System, Renal Dialysis adverse effects
- Abstract
Some medical centers re-use dialysis units sterilized with formaldehyde. In a study of 239 cases, 14 "anti-N" antibodies were found only among the 59 patients of the medical centers which re-use dialysis units. The action of formol seems to be confirmed by the presence of "anti-N" in 2 patients who had undergone prosthesis several times, but not dialysis. For these prostheses, a bone cement, sterilized with formol, was used. These "anti-N" are very often associated with cold autoagglutinins, and appear regardless of the patient's MN group. The action of formaldehyde suggests the following hypotheses:--antigenic modification;--disturbances in the immune response mechanisms;--a combination of the two. In the first hypothesis: the action of formol discovered since a long time on red cells. In the second hypothesis: the existence of auto-agglutinins only among the 14 hemo-dialysis patients with anti-N antibodies.
- Published
- 1978
- Full Text
- View/download PDF
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