1
|
Piotto M, Gambadauro A, Rocchi A, Lelii M, Madini B, Cerrato L, Chironi F, Belhaj Y, Patria MF. Pediatric Sleep Respiratory Disorders: A Narrative Review of Epidemiology and Risk Factors. Children (Basel) 2023; 10:955. [PMID: 37371187 DOI: 10.3390/children10060955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 05/09/2023] [Accepted: 05/23/2023] [Indexed: 06/29/2023]
Abstract
Sleep is a fundamental biological necessity, the lack of which has severe repercussions on the mental and physical well-being in individuals of all ages. The phrase "sleep-disordered breathing (SDB)" indicates a wide array of conditions characterized by snoring and/or respiratory distress due to increased upper airway resistance and pharyngeal collapsibility; these range from primary snoring to obstructive sleep apnea (OSA) and occur in all age groups. In the general pediatric population, the prevalence of OSA varies between 2% and 5%, but in some particular clinical conditions, it can be much higher. While adenotonsillar hypertrophy ("classic phenotype") is the main cause of OSA in preschool age (3-5 years), obesity ("adult phenotype") is the most common cause in adolescence. There is also a "congenital-structural" phenotype that is characterized by a high prevalence of OSA, appearing from the earliest ages of life, supported by morpho-structural abnormalities or craniofacial changes and associated with genetic syndromes such as Pierre Robin syndrome, Prader-Willi, achondroplasia, and Down syndrome. Neuromuscular disorders and lysosomal storage disorders are also frequently accompanied by a high prevalence of OSA in all life ages. Early recognition and proper treatment are crucial to avoid major neuro-cognitive, cardiovascular, and metabolic morbidities.
Collapse
Affiliation(s)
- Marta Piotto
- Department of Clinical Sciences and Community Health, Università degli Studi di Milano, 20122 Milan, Italy
| | - Antonella Gambadauro
- Department of Clinical Sciences and Community Health, Università degli Studi di Milano, 20122 Milan, Italy
| | - Alessia Rocchi
- Pediatric Emergency Department, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Mara Lelii
- Pediatria Pneumoinfettivologia, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Barbara Madini
- Pediatria Pneumoinfettivologia, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Lucia Cerrato
- Department of Clinical Sciences and Community Health, Università degli Studi di Milano, 20122 Milan, Italy
| | - Federica Chironi
- Department of Clinical Sciences and Community Health, Università degli Studi di Milano, 20122 Milan, Italy
| | - Youssra Belhaj
- Department of Clinical Sciences and Community Health, Università degli Studi di Milano, 20122 Milan, Italy
| | - Maria Francesca Patria
- Pediatria Pneumoinfettivologia, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| |
Collapse
|
2
|
Pensabene M, Gambazza S, Carta F, Rocchi A, Lelii M, Madini B, Hassan V, Piotto M, Patria MF. Using electrical impedance tomography to characterize lung impairment of children with primary ciliary dyskinesia: A pilot cross-sectional study. Pediatr Pulmonol 2023; 58:1051-1058. [PMID: 36571235 DOI: 10.1002/ppul.26293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 11/02/2022] [Accepted: 12/18/2022] [Indexed: 12/27/2022]
Abstract
BACKGROUND In children with primary ciliary dyskinesia (PCD), measures more sensitive than spirometry are needed to characterize underlying pulmonary impairment. Electrical impedance tomography (EIT) is a promising noninvasive method for monitoring the distribution of lung ventilation, and it does not require patient collaboration. We aimed to provide an assessment of the feasibility and clinical usefulness of EIT in characterizing lung impairment in children with PCD, compared to spirometry and multiple breath nitrogen washout (MBWN2 ) test. METHODS Children and adolescents with PCD underwent MBWN2 test as first respiratory assessment, followed by EIT monitoring and spirometry during outpatient follow-up. RESULTS We included 12 out of 16 individuals regularly followed at our clinic. A total of 41.7% (5/12) showed abnormal forced expiratory volume in 1 s (FEV1 ), whereas 11/12 (91.7%) had abnormal ventilation inhomogeneity measured with MBWN2 test. Using EIT, the global inhomogeneity (GITOT ) index showed moderate to strong correlation with FEV1 (ρ = -0.55, 95% confidence interval [CI]: -0.87 to 0.02) and ranged from 37 to 44, with the highest inhomogeneity detected in the dorsal right quadrant. GITOT was moderately correlated with RV/TLC %predicted (ρ = 0.38, 95% CI: -0.17 to 0.74), while we detected a weak correlation between GITOT and lung clearance index (ρ = 0.29, 95% CI: -0.45 to 0.82). CONCLUSION EIT appears promising as a noninvasive technique to characterize ventilation distribution in children with PCD, thus providing a complementary assessment to static and dynamic lung function measures of PCD disease.
Collapse
Affiliation(s)
- Mariacarola Pensabene
- Pediatric Highly Intensive Care Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Simone Gambazza
- Healthcare Professions Department, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Federica Carta
- Healthcare Professions Department, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Alessia Rocchi
- Pediatric Emergency Department, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Mara Lelii
- Pediatric Highly Intensive Care Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Barbara Madini
- Pediatric Highly Intensive Care Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Vittoria Hassan
- Pediatric Emergency Department, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Marta Piotto
- Pediatric Emergency Department, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Maria Francesca Patria
- Pediatric Highly Intensive Care Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| |
Collapse
|
3
|
Rovelli V, Zuvadelli J, Piotto M, Scopari A, Dionigi AR, Ercoli V, Paci S, Cefalo G, Salvatici E, Banderali G. L-alanine supplementation in Pompe disease (IOPD): a potential therapeutic implementation for patients on ERT? A case report. Ital J Pediatr 2022; 48:48. [PMID: 35346323 PMCID: PMC8962230 DOI: 10.1186/s13052-022-01249-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 03/22/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Pompe disease (PD) is a disorder of glycogen metabolism conditioning a progressive and life conditioning myopathy. Enzyme replacement therapy (ERT) is currently the best treatment option for PD, but is not resolutive. While other potential therapeutic approaches have been reported before, these have never been tried as co- treatments. L-alanine oral supplementation (LAOS) has been proven to reduce muscle breakdown: we hereby report the first case of supplementation on a PD patient on ERT.
Case presentation
F. is a 9 y.o. infantile onset Pompe Disease (IOPD) girl ERT-treated since age 1 developing a progressive myopathy. We started her on LAOS and performed assessments at baseline, 6 and 9 months. At baseline, F.’s weight, height and BMI were within normal ranges, while body composition showed low fat mass -FM and high resting energy expenditure—REE levels. After LAOS, a progressive FM increase and REE reduction could be observed both at 6 and 9 months.
Conclusions
ERT is not curative for PD patients thus additional treatments could be considered to improve outcomes. Our patient showed physical signs of inability to accumulate energy when exclusively on ERT, while FM increase and REE reduction occurred when supplemented with LAOS, likely reflecting anabolic pathways’ implementation. This is the first case reporting potential LAOS benefits in PD-on ERT patients. Longitudinal case control studies are yet needed to evaluate possible efficacy of combined LAOS And ERT treatment in PD patients.
Collapse
|
4
|
Gatti E, Piotto M, Lelii M, Pensabene M, Madini B, Cerrato L, Hassan V, Aliberti S, Bosis S, Marchisio P, Patria MF. Therapeutic Strategies for COVID-19 Lung Disease in Children. Front Pediatr 2022; 10:829521. [PMID: 35321012 PMCID: PMC8936419 DOI: 10.3389/fped.2022.829521] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Accepted: 01/20/2022] [Indexed: 12/15/2022] Open
Abstract
The novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection has milder presentation in children than in adults, mostly requiring only supportive therapy. The immunopathogenic course of COVID-19 can be divided in two distinct but overlapping phases: the first triggered by the virus itself and the second one by the host immune response (cytokine storm). Respiratory failure or systemic involvement as Multisystem Inflammatory Syndrome in Children (MIS-C) requiring intensive care are described only in a small portion of infected children. Less severe lung injury in children could be explained by qualitative and quantitative differences in age-related immune response. Evidence on the best therapeutic approach for COVID-19 lung disease in children is lacking. Currently, the approach is mainly conservative and based on supportive therapy. However, in hospitalized children with critical illness and worsening lung function, antiviral therapy with remdesivir and immunomodulant treatment could be considered the "therapeutic pillars."
Collapse
Affiliation(s)
| | | | - Mara Lelii
- Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy
| | | | | | | | | | - Stefano Aliberti
- Department of Biomedical Sciences, Humanitas University, Via Rita Levi Montalcini 4, Pieve Emanuele, Milan, Italy.,Respiratory Unit, IRCCS Humanitas Research Hospital, Via Manzoni 56, Milan, Italy
| | - Samantha Bosis
- Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Paola Marchisio
- Università Degli Studi di Milano, Milan, Italy.,Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy
| | | |
Collapse
|
5
|
|
6
|
Lancelot N, Piotto M, Theret I, Lesur B, Hennig P. Applications of NMR screening techniques to the pharmaceutical target Checkpoint kinase 1. J Pharm Biomed Anal 2013; 93:125-35. [PMID: 24280017 DOI: 10.1016/j.jpba.2013.10.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 10/17/2013] [Accepted: 10/21/2013] [Indexed: 10/26/2022]
Abstract
Ligand screening techniques based on NMR spectroscopy are not as sensitive as other commonly used methods like fluorescence, radiolabeling and surface plasmon resonance. However, using modern NMR instrumentation, they can achieve reliable screening under near physiological condition using as little as 4.6 nmol of receptor and 100 nmol of ligand. Additionally, these NMR methods can also provide valuable and specific information on the ligand under investigation such as the dissociation constant KD, the binding epitope and most importantly some structural information on the actual conformation in the bound state. In this manuscript, we describe the use of NMR based screening techniques ("Saturation Transfer Difference" (STD) and "Water Ligand Observed via Gradient SpectroscopY" (WaterLOGSY)) to detect small therapeutic molecules that interact with the DNA damage checkpoint enzyme Checkpoint kinase 1 (Chk1). After the identification of the most potent ligand, we used specific NMR experiments to perform the epitope mapping of this ligand ("Group epitope mapping-STD" (GEM-STD), "Difference of Inversion REcovery rate with and without Target IrradiatiON" (DIRECTION)) and to characterize its bound conformation ("Transferred-Nuclear Overhauser Effect SpectroscopY" (tr-NOESY), "Transferred-Rotating frame Overhauser Effect SpectroscopY" (tr-ROESY)). Finally, we used molecular docking procedures to position the ligand within the active site of Chk1. On the experimental level, a comparison between NMR studies performed in a 90%H2O/10%D2O buffer and a 100% D2O buffer is also presented and discussed.
Collapse
Affiliation(s)
- N Lancelot
- Institut de Recherches Servier, Analytical and Physical Chemistry Department, 11 rue des Moulineaux, 92150 Suresnes, France.
| | - M Piotto
- Bruker BioSpin, Laboratoire d'applications RMN, 34 rue de l'industrie, 67166 Wissembourg, France.
| | - I Theret
- Institut de Recherches Servier, Chimie Partenariats et Modélisation Moléculaire, 125 Chemin de Ronde, 78290 Croissy-Sur-Seine, France
| | - B Lesur
- Institut de Recherches Servier, Chimie Partenariats et Modélisation Moléculaire, 125 Chemin de Ronde, 78290 Croissy-Sur-Seine, France
| | - P Hennig
- Institut de Recherches Servier, Analytical and Physical Chemistry Department, 11 rue des Moulineaux, 92150 Suresnes, France
| |
Collapse
|
7
|
Moussallieh FM, Elbayed K, Chanson JB, Rudolf G, Piotto M, De Seze J, Namer IJ. Serum analysis by 1H nuclear magnetic resonance spectroscopy: a new tool for distinguishing neuromyelitis optica from multiple sclerosis. Mult Scler 2013; 20:558-65. [PMID: 24080986 DOI: 10.1177/1352458513504638] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Neuromyelitis optica (NMO) and multiple sclerosis (MS), two inflammatory demyelinating diseases, are characterized by different therapeutic strategies. Currently, the only biological diagnostic tool available to distinguish NMO from MS is the specific serum autoantibody that targets aquaporin 4, but its sensitivity is low. OBJECTIVE To assess the diagnostic accuracy of metabolomic biomarker profiles in these two neurological conditions, compared to control patients. METHODS We acquired serum spectra (47 MS, 44 NMO and 42 controls) using proton nuclear magnetic resonance ((1)H-NMR) spectroscopy. We used multivariate pattern recognition analysis to identify disease-specific metabolic profiles. RESULTS The (1)H-NMR spectroscopic analysis evidenced two metabolites, originating probably from astrocytes, scyllo-inositol and acetate, as promising serum biomarkers of MS and NMO, respectively. In 87.8% of MS patients, scyllo-inositol increased 0.15 to 3-fold, compared to controls and in 74.3% of NMO patients, acetate increased 0.4 to 7-fold, compared to controls. Using these two metabolites simultaneously, we can discriminate MS versus NMO patients (sensitivity, 94.3%; specificity, 90.2%). CONCLUSION This study demonstrates the potential of (1)H-NMR spectroscopy of serum as a novel, promising analytical tool to discriminate populations of patients affected by NMO or MS.
Collapse
|
8
|
Moussallieh FM, Chanson JB, Elbayed K, Rudolf G, Piotto M, De Seze J, Namer IJ. Utilité de l’étude métabolique du sérum par spectroscopie (HRMAS-NMR) pour distinguer la neuromyélite optique et la sclérose en plaques. Rev Neurol (Paris) 2013. [DOI: 10.1016/j.neurol.2013.01.236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
9
|
Abstract
Direct patterning of silicon dioxide by means of electron beam stimulated etching is shown, and a full characterization of exposure dose is presented. For its high dose, this technique is unsuitable for large areas but can be usefully employed like a precision scalpel for removing silicon dioxide by well-localized points. In this work, this technique is applied to the definition of windows through the oxide surrounding top down fabricated n-doped silicon nanowires. These windows will be employed for a selective doping of the nanowire by boron diffusion. In this way, pn junctions can be fabricated in well-localized points in the longitudinal direction of the nanowire, and an electrical contact to the different junctions can be provided. Electrical I-V characteristics of a nanowire with pn longitudinal junctions are reported and discussed.
Collapse
Affiliation(s)
- G Pennelli
- Dipartimento di Ingegneria della Informazione, Università di Pisa, Via G.Caruso, I-56122 Pisa, Italy.
| | | | | |
Collapse
|
10
|
Detour J, Elbayed K, Piotto M, Moussallieh F, Nehlig A, Namer I. Ultra fast in vivo microwave irradiation for enhanced metabolic stability of brain biopsy samples during HRMAS NMR analysis. J Neurosci Methods 2011; 201:89-97. [DOI: 10.1016/j.jneumeth.2011.07.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 07/11/2011] [Accepted: 07/14/2011] [Indexed: 11/26/2022]
|
11
|
Erb G, Elbayed K, Piotto M, Raya J, Neuville A, Mohr M, Maitrot D, Kehrli P, Namer I. Toward improved grading of malignancy in oligodendrogliomas using metabolomics. Magn Reson Med 2008; 59:959-65. [DOI: 10.1002/mrm.21486] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
12
|
Soubias O, Piotto M, Saurel O, Assemat O, Réat V, Milon A. Detection of natural abundance 1H-13C correlations of cholesterol in its membrane environment using a gradient enhanced HSQC experiment under high resolution magic angle spinning. J Magn Reson 2003; 165:303-308. [PMID: 14643713 DOI: 10.1016/j.jmr.2003.08.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The quality and signal to noise ratio of a J-based HETCOR performed on a standard MAS probe have been compared with a gradient enhanced HSQC performed on a HR-MAS probe at 500 MHz. The sample selected was cholesterol, inserted at 30 mol% in acyl chain deuterated phospholipids (DMPC-d54), at a temperature where the bilayer is in a liquid crystalline phase (310 K). It is representative of any rigid molecule undergoing fast axial diffusion in a bilayer as the main movement. After optimization of the spinning rate and carbon decoupling conditions, it is shown that the ge-HSQC/MAS approach is far superior to the more conventional J-HETCOR/MAS in terms of signal to noise ratio, and that it allows the detection of all the natural abundance cross peaks of cholesterol in a membrane environment. Clear differences between the 1H and 13C chemical shifts of cholesterol in a membrane and in chloroform solution were thus revealed.
Collapse
Affiliation(s)
- O Soubias
- Institut de Pharmacologie et de Biologie Structurale, CNRS and UPS, UMR 5089 205 rte de Narbonne, 31077 Toulouse, Cedex 4, France
| | | | | | | | | | | |
Collapse
|
13
|
Furrer J, Piotto M, Bourdonneau M, Limal D, Guichard G, Elbayed K, Raya J, Briand JP, Bianco A. Evidence of secondary structure by high-resolution magic angle spinning NMR spectroscopy of a bioactive peptide bound to different solid supports. J Am Chem Soc 2001; 123:4130-8. [PMID: 11457175 DOI: 10.1021/ja003566w] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The structure of the 19-amino acid peptide epitope, corresponding to the 141-159 sequence of capsid viral protein VP1 of foot-and-mouth disease virus (FMDV), bound to three different resins, namely, polystyrene-MBHA, PEGA, and POEPOP, has been determined by high-resolution magic angle spinning (HRMAS) NMR spectroscopy. A combination of homonuclear and heteronuclear bidimensional experiments was used for the complete peptide resonance assignment and the qualitative characterization of the peptide folding. The influence of the chemicophysical nature of the different polymers on the secondary structure of the covalently attached FMDV peptide was studied in detail. In the case of polystyrene-MBHA and polyacrylamide-PEGA resins, the analysis of the 2D spectra was hampered by missing signals and extensive overlaps, and only a propensity toward a peptide secondary structure could be derived from the assigned NOE correlations. When the FMDV peptide was linked to the polyoxyethylene-based POEPOP resin, it was found to adopt in dimethylformamide a helical conformation encompassing the C-terminal domain from residues 152 to 159. This conformation is very close to that of the free peptide previously analyzed in 2,2,2-trifluoroethanol. Our study clearly demonstrates that a regular helical structure can be adopted by a resin-bound bioactive peptide. Moreover, a change in the folding was observed when the same peptide-POEPOP conjugate was swollen in aqueous solution, displaying the same conformational features as the free peptide in water. The possibility of studying solid-supported ordered secondary structures by the HRMAS NMR technique in a wide range of solvents can be extended either to other biologically relevant peptides and proteins or to new synthetic oligomers.
Collapse
Affiliation(s)
- J Furrer
- Institut de Chimie, UMR 7510 CNRS-Bruker, Université Louis Pasteur, 67084 Strasbourg, France
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Bianco A, Furrer J, Limal D, Guichard G, Elbayed K, Raya J, Piotto M, Briand JP. Multistep synthesis of 2,5-diketopiperazines on different solid supports monitored by high resolution magic angle spinning NMR spectroscopy. J Comb Chem 2000; 2:681-90. [PMID: 11126296 DOI: 10.1021/cc0000489] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The solid-phase synthesis of 2,5-diketopiperazines containing the trans-4-hydroxy-L-proline amino acid residue (Hyp) was performed on Ellman polystyrene, polyoxyethylene-polyoxypropylene (POEPOP), polystyrene-polyoxyethylene NovaSyn, and Wang resins, respectively. The reaction pathway allowed the introduction of different functional groups around the bicyclic scaffold in a combinatorial approach, and it generated mixtures of isomers. A detailed characterization of the single reaction steps by high resolution magic angle spinning (HRMAS) NMR spectroscopy was performed. The NMR spectral resolution of the resin-bound intermediates and final products was greatly influenced by the polymer matrix. The POEPOP resin permitted to obtain HRMAS NMR spectra with a resolution comparable with that of the spectra of the molecules in solution. Moreover, configurational and conformational isomers formed during the solid-phase reaction steps could be detected and easily assigned. Therefore, the combination of the HRMAS NMR technique with the use of nonaromatic resins may become an extremely powerful tool in solid-phase organic synthesis. This approach will allow the monitoring of multistep reactions and the conception of on-bead structural studies either on small molecules or on natural and/or synthetic oligomers.
Collapse
Affiliation(s)
- A Bianco
- Institut de Biologie Moléculaire et Cellulaire, Laboratoire de Chimie Immunologique, UPR 9021 CNRS, Strasbourg, France
| | | | | | | | | | | | | | | |
Collapse
|
15
|
Savastano S, Piotto M, Mencarelli R, Spanio P, Rubaltelli L. [A monotypic variant of hepatic angiomyolipoma completely composed of perivascular epithelioid cells. A case]. Radiol Med 2000; 100:79-81. [PMID: 11109461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Affiliation(s)
- S Savastano
- Servizio di Radiologia, Ospedale, Cattadella, PD
| | | | | | | | | |
Collapse
|
16
|
Abstract
The new concept of slaved pulses is evaluated in the context of the study of protein hydration. The inversion properties of these pulses are shown to be superior in quality to the previously published schemes. High-quality water selective homonuclear 2D 1H NOESY-NOESY and NOESY-TOCSY experiments were recorded on horse heart ferrocytochrome c.
Collapse
Affiliation(s)
- O Bornet
- IBSM-CNRS, 31, chemin Joseph Aiguier, Marseille Cedex 20, F-13402, France
| | | | | |
Collapse
|
17
|
Elbayed K, Bourdonneau M, Furrer J, Richert T, Raya J, Hirschinger J, Piotto M. Origin of the residual NMR linewidth of a peptide bound to a resin under magic angle spinning. J Magn Reson 1999; 136:127-129. [PMID: 9887298 DOI: 10.1006/jmre.1998.1624] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The tetrapeptide Ala-lle-Gly-Met bound to a Wang resin via the methionine residue was studied by NMR under MAS conditions and compared to the same peptide in solution. The bound peptide exhibits average linewidths superior to those observed for the peptide in solution. The origin of the residual NMR linewidth observed for the bound form was investigated. The dynamics of the peptide is shown to be only marginally responsible for the increased linewidth; the major cause of the line broadening appears to be nonaveraged magnetic susceptibility differences.
Collapse
Affiliation(s)
- K Elbayed
- Institut de Chimie, UMR 7510 CNRS-Bruker, Strasbourg Cedex, F-67008, France
| | | | | | | | | | | | | |
Collapse
|
18
|
Leontis NB, Hills MT, Piotto M, Ouporov IV, Malhotra A, Gorenstein DG. Helical stacking in DNA three-way junctions containing two unpaired pyrimidines: proton NMR studies. Biophys J 1995; 68:251-65. [PMID: 7711249 PMCID: PMC1281683 DOI: 10.1016/s0006-3495(95)80182-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The proton NMR spectra of DNA three-way junction complexes (TWJ) having unpaired pyrimidines, 5'-TT- and 5'-TC- on one strand at the junction site were assigned from 2D NOESY spectra acquired in H2O and D2O solvents and homonuclear 3D NOESY-TOCSY and 3D NOESY-NOESY in D2O solvent. TWJ are the simplest branched structures found in biologically active nucleic acids. Unpaired nucleotides are common features of such structures and have been shown to stabilize junction formation. The NMR data confirm that the component oligonucleotides assemble to form conformationally homogeneous TWJ complexes having three double-helical, B-form arms. Two of the helical arms stack upon each other. The unpaired pyrimidine bases lie in the minor groove of one of the helices and are partly exposed to solvent. The coaxial stacking arrangement deduced is different from that determined by Rosen and Patel (Rosen, M.A., and D.J. Patel. 1993. Biochemistry. 32:6576-6587) for a DNA three-way junction having two unpaired cytosines, but identical to that suggested by Welch et al. (Welch, J. B., D. R. Duckett, D. M. J. Lilley. 1993. Nucleic Acids Res. 21:4548-4555) on the basis of gel electrophoretic studies of DNA three-way junctions containing unpaired adenosines and thymidines.
Collapse
Affiliation(s)
- N B Leontis
- Department of Chemistry, Bowling Green State University, Ohio 43403-0213
| | | | | | | | | | | |
Collapse
|
19
|
Abstract
The solution structure of a DNA three-way junction (TWJ) containing two unpaired thymidines was elucidated using two- and three-dimensional 1H nuclear magnetic resonance (NMR) spectroscopy. TWJs with unpaired nucleotides are ubiquitous structural motifs of complex single-stranded nucleic acids. In the presence of Mg2+, the TWJ complex adopts a unique conformation in which the bases of one of the oligonucleotides ("strand 1") are continuously stacked across the junction. Guanosine 8 of strand 3 (S3-G8), which pairs with S1-C5, stacks on S2-G5, which is paired to S1-C6. The unpaired thymidine bases (S3-T6 and S3-T7) are exposed to the solvent, whereas the sugar of S3-G8 is largely buried. S3-T6 also interacts with the sugar residue of S3-G11. All three stems conform to B-type DNA.
Collapse
Affiliation(s)
- N B Leontis
- Department of Chemistry, Bowling Green State University, Ohio 43403
| | | | | | | | | | | |
Collapse
|
20
|
Abstract
A novel approach to tailored selective excitation for the measurement of NMR spectra in non-deuterated aqueous solutions (WATERGATE, WATER suppression by GrAdient-Tailored Excitation) is described. The gradient echo sequence, which effectively combines one selective 180 degrees radiofrequency pulse and two field gradient pulses, achieves highly selective and effective water suppression. This technique is ideally suited for the rapid collection of multi-dimensional data since a single-scan acquisition produces a pure phase NMR spectrum with a perfectly flat baseline, at the highest possible sensitivity. Application to the fast measurement of 2D NOE data of a 2.2 mM solution of a double-stranded DNA fragment in 90% H2O at 5 degrees C is presented.
Collapse
Affiliation(s)
- M Piotto
- Unite Mixte de Recherche Bruker, CNRS, Universite Louis Pasteur UMR50, Wissembourg, France
| | | | | |
Collapse
|