The Experts below are selected from a list of 36921 Experts worldwide ranked by ideXlab platform
Zhong Ping Chen - One of the best experts on this subject based on the ideXlab platform.
-
an unusual combination of Mirror Image dextrocardia with familial medulloblastoma is there a histogenetic relationship
World Neurosurgery, 2017Co-Authors: Jing Wang, Junran Luo, Zhenghe Chen, Jian Wang, Zhong Ping ChenAbstract:Background The occurrence of medulloblastoma in the absence of hereditary syndromes is rare. Dextrocardia with situs inversus is also called Mirror-Image dextrocardia. A combination of Mirror-Image dextrocardia with medulloblastoma has not been reported previously. To the best of our knowledge, this is the first report of this rare combination in a family with medulloblastoma. Methods The clinical manifestation, radiographic characteristics, treatment, and outcomes of 3 medulloblastoma cases in 2 cousins and their maternal uncle was described. Tumor samples of the 2 cousins were first examined for histologic subtypes. Total RNA of their tumors was extracted from formalin-fixed and paraffin-embedded samples. Then, expression of 22 subgroup-specific genes and 3 housekeeping genes was analyzed by the NanoString nCounter Analysis System. The posttest data were normalized by NanoStringNorm package for molecular subgroup prediction. Results The proband remains tumor free and alive up to the latest follow-up. His cousin, who had combined Mirror-Image dextrocardia with situs inversus, died of anoxia after surgery and his uncle died of tumor 2.5 years after surgery. Medulloblastoma of the 2 cousins was classified as classic and molecular group 4 subtype. Conclusions The same classic and molecular group 4 subtype of the 2 cousins may suggest a similar genetic predisposition. Involvement of the Otx2 gene dysfunction in both group 4 subtype medulloblastoma and Mirror-Image dextrocardia with situs inversus points to a possible mechanism that dysfunction of a shared signaling pathway such as Otx2 might be the underlying cause of these 2 conditions in this family.
-
removal of a Mirror Image and enhancement of the signal to noise ratio in fourier domain optical coherence tomography using an electro optic phase modulator
Optics Letters, 2005Co-Authors: Jun Zhang, Stuart J Nelson, Zhong Ping ChenAbstract:A novel swept-laser-based Fourier-domain optical coherence tomography system using an electro-optic phase modulator was demonstrated. The imaging range was doubled by cancellation of the Mirror Image. The elimination of low-frequency noises resulting from dc and autocorrelation terms increased the sensitivity by 20 dB.
Christoph U Correll - One of the best experts on this subject based on the ideXlab platform.
-
long acting injectable versus oral antipsychotics in schizophrenia a systematic review and meta analysis of Mirror Image studies
The Journal of Clinical Psychiatry, 2013Co-Authors: Taishiro Kishimoto, Masahiro Nitta, Michael Borenstein, John M Kane, Christoph U CorrellAbstract:OBJECTIVE Recent, large, randomized controlled trials (RCTs) showed no benefit of long-acting injectable (LAI) antipsychotics over oral antipsychotics in preventing relapse in schizophrenia, nor did a recent meta-analysis incorporating these studies. However, RCTs might enroll a disproportionate number of patients with better treatment adherence and lower illness severity. Mirror-Image studies, which compare periods of oral antipsychotic versus LAI treatment in the same patients, might therefore better reflect the real-world impact of LAIs. DATA SOURCES A systematic literature search without language restriction was conducted using MEDLINE/PubMed, Cochrane Library, Web of Science, PsycINFO, and CINAHL until May 31, 2012. Search terms included synonyms of (1) antipsychotic(s) AND (2) schizophrenia and related disorders AND (3) depot, (long-acting) injection(s), microsphere, decanoate, palmitate, enanthate. STUDY SELECTION Of 5,483 identified citations, 607 articles were fully inspected, and 582 were ineligible. Finally, 25 Mirror-Image studies from 28 countries that followed 5,940 patients with schizophrenia for ≥ 12 months (≥ 6 months each on oral antipsychotic and LAI treatment) met the inclusion criteria and were analyzed. DATA EXTRACTION Coprimary outcomes were hospitalization risk and number of hospitalizations. Secondary outcomes included hospitalization days and length of stay. DATA SYNTHESIS LAIs showed strong superiority over oral antipsychotics in preventing hospitalization (16 studies, N = 4,066; risk ratio = 0.43; 95% CI, 0.35-0.53; P < .001) and in decreasing the number of hospitalizations (15 studies, 6,342 person-years; rate ratio = 0.38; 95% CI, 0.28-0.51; P < .001). This strong advantage was also observed for secondary outcomes and in multiple clinically relevant subpopulations and treatment groups. CONCLUSIONS Results from Mirror-Image studies in patients eligible for clinical use of LAIs showed strong superiority of LAIs compared to oral antipsychotics in preventing hospitalization. The results were in contrast to the recent meta-analysis of RCTs, which showed no superiority of LAIs. Given the possible biases in Mirror-Image studies, such as expectation bias, natural illness course, and time effect, a cautious interpretation is required. Nevertheless, the population in Mirror-Image studies better reflects the population receiving LAIs in clinical practice.
-
real world effectiveness of clozapine in patients with bipolar disorder results from a 2 year Mirror Image study
Bipolar Disorders, 2012Co-Authors: Jimmi Nielsen, John M Kane, Christoph U CorrellAbstract:Nielsen J, Kane JM, Correll CU. Real-world effectiveness of clozapine in patients with bipolar disorder: results from a 2-year Mirror-Image study. Bipolar Disord 2012: 14: 863–869. © 2012 John Wiley & Sons A/S.Published by Blackwell Publishing Ltd. Objectives: Clozapine remains the drug of choice for treatment-resistant schizophrenia but the evidence for its use in severe bipolar disorder (BD) remains sparse. Methods: A pharmaco-epidemiologic database study was carried out in Denmark, investigating the effectiveness of clozapine in BD patients (without a schizophrenia-spectrum disorder), between 1996 and 2007, using a two-year Mirror-Image design. Results: A total of 21473 patients with a lifetime diagnosis of International Classification of Diseases-10 (ICD-10) BD were identified, of which only 326 (1.5%) were treated with clozapine and were included in the Mirror-Image analysis. The mean follow-up time was 544 ± 280 days, the mean clozapine dose was 307.4 mg [95% confidence interval (CI): 287.9–328.2], and 39.3% were male. During clozapine treatment, the mean number of bed-days decreased from 177.8 (95% CI: 149.4–211.6) to 34.6 (95% CI: 24.8–48.2) (p < 0.001). The mean number of admissions was reduced from 3.2 (95% CI: 2.9–3.7) to 2.0 (95% CI: 1.6–2.4) (p < 0.001). Overall, 240 patients (73.6%) had reduced bed-days and 130 (39.9%) were not admitted while treated with clozapine. Moreover, the number of psychotropic co-medications was reduced from 4.5 defined daily doses (DDD) (25–75 percentiles: 2.4–8.2) to 3.9 DDD (25–75 percentiles: 2.4–6.1) (p = 0.045). Somatic hospital visits for intentional self-harm/overdose reduced significantly from 8.3% to 3.1% (p = 0.004). However, non-psychotropic co-medication use for medical conditions did not increase; 0.7 DDD (25–75 percentiles: 0.0–2.9) to 0.8 DDD (25–75 percentiles: 0.1–2.89) (p = 0.3). Conclusions: Clozapine use for BD was associated with a significant and clinically relevant reduction in the number of bed-days, psychiatric admissions, psychotropic co-medications, and hospital contact for self-harm/overdose, without increased medical treatments. Clozapine seems to be an appropriate choice for treatment-resistant BD and should be investigated in randomized controlled trials.
Stephen B H Kent - One of the best experts on this subject based on the ideXlab platform.
-
Mirror Image forms of snow flea antifreeze protein prepared by total chemical synthesis have identical antifreeze activities
Journal of the American Chemical Society, 2008Co-Authors: Brad L Pentelute, Zachary P Gates, Jennifer L Dashnau, Jane M Vanderkooi, Stephen B H KentAbstract:The recently discovered glycine-rich snow flea antifreeze protein (sfAFP) has no sequence homology with any known proteins. No experimental structure has been reported for this interesting protein molecule. Here we report the total chemical synthesis of the Mirror Image forms of sfAFP (i.e., l-sfAFP, the native protein, and d-sfAFP, the native protein’s enantiomer). The predicted 81 amino acid residue polypeptide chain of sfAFP contains Cys residues at positions 1, 13, 28, and 43 and was prepared from four synthetic peptide segments by sequential native chemical ligation. After purification, the full-length synthetic polypeptide was folded at 4 °C to form the sfAFP protein containing two disulfides. Chemically synthesized sfAFP had the expected antifreeze activity in an ice recrystallization inhibition assay. Mirror Image d-sfAFP protein was prepared by the same synthetic strategy, using peptide segments made from d-amino acids, and had an identical but opposite-sign CD spectrum. As expected, d-sfAFP disp...
-
Mirror Image forms of snow flea antifreeze protein prepared by total chemical synthesis have identical antifreeze activities
Journal of the American Chemical Society, 2008Co-Authors: Brad L Pentelute, Zachary P Gates, Jennifer L Dashnau, Jane M Vanderkooi, Stephen B H KentAbstract:The recently discovered glycine-rich snow flea antifreeze protein (sfAFP) has no sequence homology with any known proteins. No experimental structure has been reported for this interesting protein molecule. Here we report the total chemical synthesis of the Mirror Image forms of sfAFP (i.e., L-sfAFP, the native protein, and D-sfAFP, the native protein's enantiomer). The predicted 81 amino acid residue polypeptide chain of sfAFP contains Cys residues at positions 1, 13, 28, and 43 and was prepared from four synthetic peptide segments by sequential native chemical ligation. After purification, the full-length synthetic polypeptide was folded at 4 degrees C to form the sfAFP protein containing two disulfides. Chemically synthesized sfAFP had the expected antifreeze activity in an ice recrystallization inhibition assay. Mirror Image D-sfAFP protein was prepared by the same synthetic strategy, using peptide segments made from d-amino acids, and had an identical but opposite-sign CD spectrum. As expected, D-sfAFP displays the same antifreeze properties as L-sfAFP, because ice presents an achiral surface for sfAFP binding. Facile synthetic access to sfAFP will enable determination of its molecular structure and systematic elucidation of the molecular basis of the antifreeze properties of this unique protein.
-
an 1h nmr determination of the three dimensional structures of Mirror Image forms of a leu 5 variant of the trypsin inhibitor from ecballium elaterium eeti ii
Protein Science, 1994Co-Authors: Katherine J Nielsen, Stephen B H Kent, Dianne Alewood, John L Andrews, David J CraikAbstract:The 3-dimensional structures of Mirror-Image forms of a Leu-5 variant of the trypsin inhibitor Ecballium elaterium (EETI-II) have been determined by 1H NMR spectroscopy and simulated annealing calculations incorporating NOE-derived distance constraints. Spectra were assigned using 2-dimensional NMR methods at 400 MHz, and internuclear distances were determined from NOESY experiments. Three-bond spin-spin couplings between C alpha H and amide protons, amide exchange rates, and the temperature dependence of amide chemical shifts were also measured. The structure consists largely of loops and turns, with a short region of beta-sheet. The Leu-5 substitution produces a substantial reduction in affinity for trypsin relative to native EETI-II, which contains an Ile at this position. The global structure of the Leu-5 analogue studied here is similar to that reported for native EETI-II (Heitz A, Chiche L, Le-Nguyen D, Castro B, 1989, Biochemistry 28:2392-2398) and to X-ray and NMR structures of the related proteinase inhibitor CMTI-I (Bode W et al., 1989, FEBS Lett 242:285-292; Holak TA et al., 1989a, J Mol Biol 210:649-654; Holak TA, Gondol D, Otlewski J, Wilusz T, 1989b, J Mol Biol 210:635-648; Holak TA, Habazettl J, Oschkinat H, Otlewski J, 1991, J Am Chem Soc 113:3196-3198). The region near the scissile bond is the most disordered part of the structure, based on geometric superimposition of 40 calculated structures. This disorder most likely reflects additional motion being present in this region relative to the rest of the protein. This motional disorder is increased in the Leu-5 analogue relative to the native form and may be responsible for its reduced trypsin binding. A second form of the protein synthesized with all (D) amino acids was also studied by NMR and found to have a spectrum identical with that of the (L) form. This is consistent with the (D) form being a Mirror Image of the (L) form and not distinguishable by NMR in an achiral solvent (i.e., H2O). The (D) form has no activity against trypsin, as would be expected for a Mirror-Image form.
Annalisa Guaragna - One of the best experts on this subject based on the ideXlab platform.
-
1 5 anhydro l ribo hexitol adenine nucleic acids α l hna a synthesis and chiral selection properties in the Mirror Image world
Journal of Organic Chemistry, 2015Co-Authors: Daniele Dalonzo, Guy Schepers, Arthur Van Aerschot, Piet Herdewijn, Giovanni Palumbo, Mathy Froeyen, Giovanni Di Fabio, Annalisa GuaragnaAbstract:The synthesis and a preliminary investigation of the base pairing properties of (6′ → 4′)-linked 1′,5′-anhydro-l-ribo-hexitol nucleic acids (α-l-HNA) have herein been reported through the study of a model oligoadenylate system in the Mirror Image world. Despite its considerable preorganization due to the rigidity of the “all equatorial” pyranyl sugar backbone, α-l-HNA represents a versatile informational biopolymer, in view of its capability to cross-communicate with natural and unnatural complements in both enantiomeric forms. This seems the result of an inherent flexibility of the oligonucleotide system, as witnessed by the singular formation of iso- and heterochiral associations composed of regular, enantiomorphic helical structures. The peculiar properties of α-l-HNA (and most generally of the α-HNA system) provide new elements in our understanding of the structural prerequisites ruling the stereoselectivity of the hybridization processes of nucleic acids.
-
1′,5′-Anhydro‑l-ribo-hexitol Adenine Nucleic Acids (α‑l‑HNA-A): Synthesis and Chiral Selection Properties in the Mirror Image World
2015Co-Authors: Daniele D’alonzo, Guy Schepers, Arthur Van Aerschot, Piet Herdewijn, Giovanni Palumbo, Mathy Froeyen, Giovanni Di Fabio, Annalisa GuaragnaAbstract:The synthesis and a preliminary investigation of the base pairing properties of (6′ → 4′)-linked 1′,5′-anhydro-l-ribo-hexitol nucleic acids (α-l-HNA) have herein been reported through the study of a model oligoadenylate system in the Mirror Image world. Despite its considerable preorganization due to the rigidity of the “all equatorial” pyranyl sugar backbone, α-l-HNA represents a versatile informational biopolymer, in view of its capability to cross-communicate with natural and unnatural complements in both enantiomeric forms. This seems the result of an inherent flexibility of the oligonucleotide system, as witnessed by the singular formation of iso- and heterochiral associations composed of regular, enantiomorphic helical structures. The peculiar properties of α-l-HNA (and most generally of the α-HNA system) provide new elements in our understanding of the structural prerequisites ruling the stereoselectivity of the hybridization processes of nucleic acids
Dieter Willbold - One of the best experts on this subject based on the ideXlab platform.
-
selection of d amino acid peptides that bind to alzheimer s disease amyloid peptide aβ1 42 by Mirror Image phage display
ChemBioChem, 2003Co-Authors: Katja Wiesehan, Katrin Buder, Reinhold P Linke, Stephan Patt, Matthias Stoldt, Eberhard Unger, Bettina Schmitt, Enrico M Bucci, Dieter WillboldAbstract:: A Mirror Image phage display approach was used to identify novel and highly specific ligands for Alzheimer's disease amyloid peptide Abeta(1-42). A randomized 12-mer peptide library presented on M13 phages was screened for peptides with binding affinity for the Mirror Image of Abeta(1-42). After four rounds of selection and amplification the peptides were enriched with a dominating consensus sequence. The Mirror Image of the most representative peptide (D-pep) was shown to bind Abeta(1-42) with a dissociation constant in the submicromolar range. Furthermore, in brain tissue sections derived from patients that suffered from Alzheimer's disease, amyloid plaques and leptomeningeal vessels containing Abeta amyloid were stained specifically with a fluorescence-labeled derivative of D-pep. Fibrillar deposits derived from other amyloidosis were not labeled by D-pep. Possible applications of this novel and highly specific Abeta ligand in diagnosis and therapy of Alzheimer's disease are discussed.
-
selection of d amino acid peptides that bind to alzheimer s disease amyloid peptide a beta 1 42 by Mirror Image phage display
ChemBioChem, 2003Co-Authors: Katja Wiesehan, Katrin Buder, Reinhold P Linke, Stephan Patt, Matthias Stoldt, Eberhard Unger, Bettina Schmitt, Enrico Bucci, Dieter WillboldAbstract:A Mirror Image phage display approach was used to identify novel and highly specific ligands for Alzheimer's disease amyloid peptide Aβ(1–42). A randomized 12-mer peptide library presented on M13 phages was screened for peptides with binding affinity for the Mirror Image of Aβ(1–42). After four rounds of selection and amplification the peptides were enriched with a dominating consensus sequence. The Mirror Image of the most representative peptide (D-pep) was shown to bind Aβ(1–42) with a dissociation constant in the submicromolar range. Furthermore, in brain tissue sections derived from patients that suffered from Alzheimer's disease, amyloid plaques and leptomeningeal vessels containing Aβ amyloid were stained specifically with a fluorescence-labeled derivative of D-pep. Fibrillar deposits derived from other amyloidosis were not labeled by D-pep. Possible applications of this novel and highly specific Aβ ligand in diagnosis and therapy of Alzheimer's disease are discussed.
