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1.
Surgeon ; 2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38677960

RESUMEN

OBJECTIVES/AIMS: The primary aim of this study was to assess the current standard of shoulder radiographs in Ireland. The secondary aim of this study was to determine whether orthopaedic surgeons in Ireland are of the opinion that a national protocol is required, and what this protocol should consist of. METHODS: A national audit of shoulder trauma series x-rays performed in emergency departments was conducted. The number and type of views performed was recorded. The anteroposterior (AP) and axillary or Velpeau views were assessed to determine if they met pre-defined audit criteria. Consultant orthopaedic surgeons working in public trauma hospitals were invited to participate in an online survey by email. RESULTS: The number of shoulder trauma series included in this audit was 789. The majority of patients had two views performed (75.92%, n â€‹= â€‹599) and 21.17% (n â€‹= â€‹167) had an axillary or Velpeau view. The AP view met the audit criteria in 23.09% (n â€‹= â€‹181) of cases. The survey response rate was 70.8% (n â€‹= â€‹17). 88.2% (n â€‹= â€‹15) of surgeons agreed that three views should be performed for a shoulder trauma series and 94.12% (n â€‹= â€‹16) agreed that an axillary or Velpeau view should be included. The majority of surgeons surveyed (94%, n â€‹= â€‹16) are in favour of establishing a national protocol. CONCLUSION: The current standard shoulder trauma series in Irish hospitals consists of two views, most frequently a thoracic AP and a scapular Y view. We propose the introduction of a national protocol consisting of three views: Grashey AP, Scapular Y, and an axillary or Velpeau view.

2.
Genes Dev ; 38(5-6): 253-272, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38565249

RESUMEN

Oncogenic activation of MYC in cancers predominantly involves increased transcription rather than coding region mutations. However, MYC-dependent lymphomas frequently acquire point mutations in the MYC phosphodegron, including at threonine 58 (T58), where phosphorylation permits binding via the FBW7 ubiquitin ligase triggering MYC degradation. To understand how T58 phosphorylation functions in normal cell physiology, we introduced an alanine mutation at T58 (T58A) into the endogenous c-Myc locus in the mouse germline. While MYC-T58A mice develop normally, lymphomas and myeloid leukemias emerge in ∼60% of adult homozygous T58A mice. We found that primitive hematopoietic progenitor cells from MYC-T58A mice exhibit aberrant self-renewal normally associated with hematopoietic stem cells (HSCs) and up-regulate a subset of MYC target genes important in maintaining stem/progenitor cell balance. In lymphocytes, genomic occupancy by MYC-T58A was increased at all promoters compared with WT MYC, while genes differentially expressed in a T58A-dependent manner were significantly more proximal to MYC-bound enhancers. MYC-T58A lymphocyte progenitors exhibited metabolic alterations and decreased activation of inflammatory and apoptotic pathways. Our data demonstrate that a single point mutation stabilizing MYC is sufficient to skew target gene expression, producing a profound gain of function in multipotential hematopoietic progenitors associated with self-renewal and initiation of lymphomas and leukemias.


Asunto(s)
Proteína 7 que Contiene Repeticiones F-Box-WD , Neoplasias Hematológicas , Linfoma , Proteínas Proto-Oncogénicas c-myc , Animales , Ratones , Células Germinativas/metabolismo , Células Madre Hematopoyéticas/metabolismo , Mutación Puntual , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Proteína 7 que Contiene Repeticiones F-Box-WD/metabolismo
3.
ACS Appl Mater Interfaces ; 16(14): 17857-17869, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38533949

RESUMEN

Electron-rich organocerium complexes (C5Me4H)3Ce and [(C5Me5)2Ce(ortho-oxa)], with redox potentials E1/2 = -0.82 V and E1/2 = -0.86 V versus Fc/Fc+, respectively, were reacted with fullerene (C60) in different stoichiometries to obtain molecular materials. Structurally characterized cocrystals: [(C5Me4H)3Ce]2·C60 (1) and [(C5Me5)2Ce(ortho-oxa)]3·C60 (2) of C60 with cerium-based, molecular rare earth precursors are reported for the first time. The extent of charge transfer in 1 and 2 was evaluated using a series of physical measurements: FT-IR, Raman, solid-state UV-vis-NIR spectroscopy, X-ray absorption near-edge structure (XANES) spectroscopy, and magnetic susceptibility measurements. The physical measurements indicate that 1 and 2 comprise the cerium(III) oxidation state, with formally neutral C60 as a cocrystal in both cases. Pressure-dependent periodic density functional theory calculations were performed to study the electronic structure of 1. Inclusion of a Hubbard-U parameter removes Ce f states from the Fermi level, opens up a band gap, and stabilizes FM/AFM magnetic solutions that are isoenergetic because of the large distances between the Ce(III) cations. The electronic structure of this strongly correlated Mott insulator-type system is reminiscent of the well-studied Ce2O3.

4.
Elife ; 122024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-38386003

RESUMEN

Touch sensation is primarily encoded by mechanoreceptors, called low-threshold mechanoreceptors (LTMRs), with their cell bodies in the dorsal root ganglia. Because of their great diversity in terms of molecular signature, terminal endings morphology, and electrophysiological properties, mirroring the complexity of tactile experience, LTMRs are a model of choice to study the molecular cues differentially controlling neuronal diversification. While the transcriptional codes that define different LTMR subtypes have been extensively studied, the molecular players that participate in their late maturation and in particular in the striking diversity of their end-organ morphological specialization are largely unknown. Here we identified the TALE homeodomain transcription factor Meis2 as a key regulator of LTMRs target-field innervation in mice. Meis2 is specifically expressed in cutaneous LTMRs, and its expression depends on target-derived signals. While LTMRs lacking Meis2 survived and are normally specified, their end-organ innervations, electrophysiological properties, and transcriptome are differentially and markedly affected, resulting in impaired sensory-evoked behavioral responses. These data establish Meis2 as a major transcriptional regulator controlling the orderly formation of sensory neurons innervating peripheral end organs required for light touch.


Asunto(s)
Proteínas de Homeodominio , Fenómenos Fisiológicos del Sistema Nervioso , Factores de Transcripción , Animales , Ratones , Regulación de la Expresión Génica , Mecanorreceptores , Células Receptoras Sensoriales , Factores de Transcripción/genética , Proteínas de Homeodominio/genética
5.
J Am Chem Soc ; 146(5): 2997-3009, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38272018

RESUMEN

Reported is the catalytic cyclic polymer synthesis by a 3d transition metal complex: a V(V) alkylidyne, [(dBDI)V≡CtBu(OEt2)] (1-OEt2), supported by the deprotonated ß-diketiminate dBDI2- (dBDI2- = ArNC(CH3)CHC(CH2)NAr, Ar = 2,6-iPr2C6H3). Complex 1-OEt2 is a precatalyst for the polymerization of phenylacetylene (PhCCH) to give cyclic poly(phenylacetylene) (c-PPA), whereas its precursor, complex [(BDI)V≡CtBu(OTf)] (2-OTf; BDI- = [ArNC(CH3)]2CH, Ar = 2,6-iPr2C6H3, OTf = OSO2CF3), and the zwitterion [((C6F5)3B-dBDI)V≡CtBu(OEt2)] (3-OEt2) exhibit low catalytic activity despite having a neopentylidyne ligand. Cyclic polymer topologies were verified by size-exclusion chromatography (SEC) and intrinsic viscosity studies. A component of the mechanism of the cyclic polymerization reaction was probed by isolation and full characterization of 4- and 6-membered metallacycles as model intermediates. Metallacyclobutadiene (MCBD) and deprotiometallacyclobutadiene (dMCBD) complexes (dBDI)V[C(tBu)C(H)C(tBu)] (4-tBu) and (BDI)V[C(tBu)CC(Mes)] (5-Mes), respectively, were synthesized upon reaction with bulkier alkynes, tBu- (tBuCCH) and Mes-acetylene (MesCCH), with 1-OEt2. Furthermore, the reaction of the conjugate acid of 1-OEt2, [(BDI)V≡CtBu(OTf)] (2-OTf), with the conjugated base of phenylacetylene, lithium phenylacetylide (LiCCPh), yields the doubly deprotio-metallacycle complex, [Li(THF)4]{(BDI)V[C(Ph)CC(tBu)CC(Ph)]} (6). Protonation of the doubly deprotio-metallacycle complex 6 yields 6-H+, a catalytically active species toward the polymerization of PhCCH, for which the polymers were also confirmed to be cyclic by SEC studies. Computational mechanistic studies complement the experimental observations and provide insight into the mechanism of cyclic polymer growth. The noninnocence of the supporting dBDI2- ligand and its role in proton shuttling to generate deprotiometallacyclobutadiene (dMCBD) complexes that proposedly culminate in the formation of catalytically active V(III) species are also discussed. This work demonstrates how a dMCBD moiety can react with terminal alkynes to form cyclic polyalkynes.

6.
Vet Dermatol ; 35(2): 138-147, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38057947

RESUMEN

BACKGROUND: Artificial intelligence (AI) has been used successfully in human dermatology. AI utilises convolutional neural networks (CNN) to accomplish tasks such as image classification, object detection and segmentation, facilitating early diagnosis. Computer vision (CV), a field of AI, has shown great results in detecting signs of human skin diseases. Canine paw skin diseases are a common problem in general veterinary practice, and computer vision tools could facilitate the detection and monitoring of disease processes. Currently, no such tool is available in veterinary dermatology. ANIMALS: Digital images of paws from healthy dogs and paws with pododermatitis or neoplasia were used. OBJECTIVES: We tested the novel object detection model Pawgnosis, a Tiny YOLOv4 image analysis model deployed on a microcomputer with a camera for the rapid detection of canine pododermatitis and neoplasia. MATERIALS AND METHODS: The prediction performance metrics used to evaluate the models included mean average precision (mAP), precision, recall, average precision (AP) for accuracy and frames per second (FPS) for speed. RESULTS: A large dataset labelled by a single individual (Dataset A) used to train a Tiny YOLOv4 model provided the best results with a mean mAP of 0.95, precision of 0.86, recall of 0.93 and 20 FPS. CONCLUSIONS AND CLINICAL RELEVANCE: This novel object detection model has the potential for application in the field of veterinary dermatology.


Asunto(s)
Dermatitis , Enfermedades de los Perros , Neoplasias , Humanos , Perros , Animales , Inteligencia Artificial , Dermatitis/diagnóstico , Dermatitis/veterinaria , Piel , Enfermedades de los Perros/diagnóstico , Neoplasias/veterinaria
7.
J Orthop ; 48: 68-71, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38106625

RESUMEN

Introduction: A recent study based on a large osteological collection reported an association between clavicle fractures and osteoarthritis of the glenohumeral joint. No clinical study has yet addressed this potential association. Other radiographic parameters such as the critical shoulder angle have been associated with the risk of glenohumeral joint osteoarthritis. The primary outcome of this study was to determine if there is an association between glenohumeral joint arthritis and clavicle fractures. The secondary outcome was to determine the association between critical shoulder angle and glenohumeral joint arthritis in our patient cohort. Methods: We retrospectively analysed 572 consecutive shoulder arthroplasty surgeries. Osteoarthritis was the indication for 343 shoulder arthroplasties. 229 shoulder arthroplasties were performed due to another diagnosis such as trauma or fracture, cuff arthropathy, or revision surgery. Three fellowship trained consultant shoulder surgeons assessed the pre- and post-operative radiographs of all patients. Results: A clavicle fracture was suspected in 5/343 (1.5 %) shoulder arthroplasties performed due to osteoarthritis and 5/229 (2.1 %) shoulder arthroplasties performed for another diagnosis. Interobserver variability was assessed using a Fisher Exact test and showed no significant relationship between osteoarthritis and a fracture of the clavicle (p = 0.531). Critical shoulder angle results correlated with the previously published literature regarding critical shoulder angle and osteoarthritis and rotator cuff arthropathy. Conclusion: Clavicle fractures were not associated with glenohumeral osteoarthritis in our patient cohort of shoulder arthroplasty patients. Critical shoulder angle results were consistent with published literature. Further research in the form of prospective long term studies are needed to establish if any association exists between clavicle fractures and osteoarthritis of the glenohumeral joint. Level of evidence: Level III. Retrospective analysis.

8.
Angew Chem Int Ed Engl ; 63(8): e202318956, 2024 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-38109203

RESUMEN

Described here is a direct entry to two examples of 3d transition metal catalysts that are active for the cyclic polymerization of phenylacetylene, namely, [(BDI)M{κ2 -C,C-(Me3 SiC3 SiMe3 )}] (2-M) (BDI=[ArNC(CH3 )]2 CH- , Ar=2,6-i Pr2 C6 H3 ; M=Ti, V). Catalysts are prepared in one step by the treatment of [(BDI)MCl2 ] (1-M, M=Ti, V) with 1,3-dilithioallene [Li2 (Me3 SiC3 SiMe3 )]. Complexes 2-M have been spectroscopically and structurally characterized and the polymers that are catalytically formed from phenylacetylene were verified to have a cyclic topology based on a combination of size-exclusion chromatography (SEC) and intrinsic viscosity studies. Two-electron oxidation of 2-V with nitrous oxide (N2 O) cleanly yields a [VV ] alkylidene-alkynyl oxo complex [(BDI)V(=O){κ1 -C-(=C(SiMe3 )CC(SiMe3 ))}] (3), which lends support for how this scaffold in 2-M might be operating in the polymerization of the terminal alkyne. This work demonstrates how alkylidynes can be circumvented using 1,3-dianionic allene as a segue into M-C multiple bonds.

9.
Inorg Chem ; 2023 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-38097382

RESUMEN

The synthesis and characterization of two cerium complexes of redox-active amine/amido-phenolate-type ligands are reported. A tripodal framework comprising the tris(2-(3',5'-di-tert-butyl-2'-hydroxyphenyl)amino-phenyl) amine (H6Clamp) proligand was synthesized for comparison of its cerium complex with a potassium-cerium heterobimetallic complex of the 4,6-di-tert-butyl-2-[(2,6-diisopropylphenyl)imino]quinone (dippap) proligand. Structural studies indicate differences in the cerium(III) cation coordination spheres, where CeIII(CH3CN)1.5(H3Clamp) (1-Ce(H3Clamp)) exhibits shorter Ce-O distances and longer Ce-N bond distances compared to the analogous distances in K3(THF)3CeIII(dippap)3 (2-Ce(ap)), due to the gross structural differences between the systems. Differences are also evident in the temperature-dependent magnetic properties, where smaller χT products were observed for 2-Ce(ap) compared to 1-Ce(H3Clamp). Solution electrochemical studies for the complexes were interpreted based on ligand- and metal-based oxidation events, and the cerium(III) oxidation of 2-Ce(ap) was observed to be more facile than that of 1-Ce(H3Clamp), behavior that was cautiously attributed to the rigidity of the encrypted 1-Ce(H3Clamp) complex compared to the heterobimetallic framework of 2-Ce(ap). These results contribute to the understanding of how ligand designs can promote facile redox cycling for cerium complexes of redox-active ligands, given the large contraction of cerium-ligand bonds upon oxidation.

10.
Inorg Chem ; 62(47): 19238-19247, 2023 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-37956394

RESUMEN

While niobium and tantalum are found together in their mineral ores, their respective applications in technology require chemical separation. Nb/Ta separations are challenging due to the similar reactivities displayed by these metals in the solution phase. Coordination complexes of these metals have been studied in the contexts of catalysis, small-molecule activation, and functional group insertion reactivity; relatively few studies exist directly comparing the properties of isostructural Nb/Ta complexes. Such comparisons advance the development of Nb/Ta separation chemistry through the potential for differential reactivity. Here, we explore fundamental physicochemical properties in extensively characterized Nb/Ta coordination complexes [Na(DME)3][MClamp], (Clamp6- = tris-(2-(3',5'-di-tert-butyl-2'-oxyphenyl)amidophenyl)amine; M = Nb, Ta) to advance the understanding of the different electronic, optical, and excited-state properties that these metals exhibit in pi-loaded coordination complexes.

11.
bioRxiv ; 2023 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-37961183

RESUMEN

Oncogenic activation of MYC in cancers predominantly involves increased transcription rather than coding region mutations. However, MYC-dependent lymphomas frequently contain point mutations in the MYC phospho-degron, including at threonine-58 (T58), where phosphorylation permits binding by the FBW7 ubiquitin ligase triggering MYC degradation. To understand how T58 phosphorylation functions in normal cell physiology, we introduced an alanine mutation at T58 (T58A) into the endogenous c-Myc locus in the mouse germline. While MYC-T58A mice develop normally, lymphomas and myeloid leukemias emerge in ~60% of adult homozygous T58A mice. We find that primitive hematopoietic progenitor cells from MYC-T58A mice exhibit aberrant self-renewal normally associated with hematopoietic stem cells (HSCs) and upregulate a subset of Myc target genes important in maintaining stem/progenitor cell balance. Genomic occupancy by MYC-T58A was increased at all promoters, compared to WT MYC, while genes differentially expressed in a T58A-dependent manner were significantly more proximal to MYC-bound enhancers. MYC-T58A lymphocyte progenitors exhibited metabolic alterations and decreased activation of inflammatory and apoptotic pathways. Our data demonstrate that a single point mutation in Myc is sufficient to produce a profound gain of function in multipotential hematopoietic progenitors associated with self-renewal and initiation of lymphomas and leukemias.

12.
Chem Sci ; 14(43): 12277-12282, 2023 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-37969607

RESUMEN

We show in this work how lithium tellurolate Li(X)nTeCH2SiMe3 (X = THF, n = 1, 1; X = 12-crown-4, n = 2, 2), can serve as an effective Te-atom transfer reagent to all group 5 transition metal halide precursors irrespective of the oxidation state. Mononuclear and bis(telluride) complexes, namely (PNP)M(Te)2 (M = V; Nb, 3; Ta, 4; PNP- = N[2-PiPr2-4-methylphenyl]2), are reported herein including structural and spectroscopic data. Whereas the known complex (PNP)V(Te)2 can be readily prepared from the trivalent precursor (PNP)VCl2, two equiv. of tellurolate, and elemental Te partially solubilized with PMe3, complex 3 can also be similarly obtained following the same procedure but with or without a reductant, Na/NaCl. Complex 4 on the other hand is formed from the addition of four equiv. of tellurolate to (PNP)TaF4. Having access to a triad of (PNP)M(Te)2 systems for group 5 metals has allowed us to compare them using a combination of theory and spectroscopy including Te-L1 edge XANES data.

13.
Angew Chem Int Ed Engl ; 62(51): e202311749, 2023 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-37815099

RESUMEN

Here we report the use of a base metal complex [(tBu pyrpyrr2 )Fe(OEt2 )] (1-OEt2 ) (tBu pyrpyrr2 2- =3,5-tBu2 -bis(pyrrolyl)pyridine) as a catalyst for intermolecular amination of Csp3 -H bonds of 9,10-dihydroanthracene (2 a) using 2,4,6-trimethyl phenyl azide (3 a) as the nitrene source. The reaction is complete within one hour at 80 °C using as low as 2 mol % 1-OEt2 with control in selectivity for single C-H amination versus double C-H amination. Catalytic C-H amination reactions can be extended to other substrates such as cyclohexadiene and xanthene derivatives and can tolerate a variety of aryl azides having methyl groups in both ortho positions. Under stoichiometric conditions the imido radical species [(tBu pyrpyrr2 )Fe{=N(2,6-Me2 -4-tBu-C6 H2 )] (1-imido) can be isolated in 56 % yield, and spectroscopic, magnetometric, and computational studies confirmed it to be an S = 1 FeIV complex. Complex 1-imido reacts with 2 a to produce the ferrous aniline adduct [(tBu pyrpyrr2 )Fe{NH(2,6-Me2 -4-tBu-C6 H2 )(C14 H11 )}] (1-aniline) in 45 % yield. Lastly, it was found that complexes 1-imido and 1-aniline are both competent intermediates in catalytic intermolecular C-H amination.

14.
Chem Commun (Camb) ; 59(67): 10101-10104, 2023 Aug 17.
Artículo en Inglés | MEDLINE | ID: mdl-37417771

RESUMEN

We report the first mononuclear TiIII complex possessing a terminal imido ligand. Complex [TptBu,MeTi{NSi(CH3)3}(THF)] (2) (TptBu,Me = hydridotris(3-tert-butyl-5-methylpyrazol-1-yl)borate) is prepared by reduction of [TptBu,MeTi{NSi(CH3)3}(Cl)] (1) with KC8 in high yield. The connectivity and metalloradical nature of 2 were confirmed by single crystal X-ray diffraction studies, Q- and X-band EPR, UV-Vis and 1H NMR spectroscopies. The d1 complex [(TptBu,Me)TiCl(OEt2)][B(C6F5)4] (3), was prepared to spectroscopically compare it to 2. Electrochemical studies of 1 and 2 reveal a reversible 1e- process, and chemical oxidants ClCPh3 or 1/2 eq. XeF2 react cleanly with 2 yielding 1 or the fluoride derivative [TptBu,MeTi{NSi(CH3)3}(F)] (4), respectively.

15.
Inorg Chem ; 62(29): 11487-11499, 2023 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-37428000

RESUMEN

This article describes the synthesis, characterization, and S-atom transfer reactivity of a series of C3v-symmetric diiron complexes. The iron centers in each complex are coordinated in distinct ligand environments, with one (FeN) bound in a pseudo-trigonal bipyramidal geometry by three phosphinimine nitrogens in the equatorial plane, a tertiary amine, and the second metal center (FeC). FeC is coordinated, in turn, by FeN, three ylidic carbons in a trigonal plane, and, in certain cases, by an axial oxygen donor. The three alkyl donors at FeC form through the reduction of the appended N═PMe3 arms of the monometallic parent complex. The complexes were studied crystallographically, spectroscopically (NMR, UV-vis, and Mössbauer), and computationally (DFT, CASSCF) and found to be high-spin throughout, with short Fe-Fe distances that belie weak orbital overlap between the two metals. Further, the redox nature of this series allowed for the determination that oxidation is localized to the FeC. S-atom transfer chemistry resulted in the formal insertion of a S atom into the Fe-Fe bond of the reduced diiron complex to form a mixture of Fe4S and Fe4S2 products.

16.
J Am Chem Soc ; 145(30): 16374-16382, 2023 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-37467432

RESUMEN

Manifesting chemical differences in individual rare earth (RE) element complexes is challenging due to the similar sizes of the tripositive cations and the corelike 4f shell. We disclose a new strategy for differentiating between similarly sized Dy3+ and Y3+ ions through a tailored photochemical reaction of their isostructural complexes in which the f-electron states of Dy3+ act as an energy sink. Complexes RE(hfac)3(NMMO)2 (RE = Dy (2-Dy) and Y (2-Y), hfac = hexafluoroacetylacetonate, and NMMO = N-methylmorpholine-N-oxide) showed variable rates of oxygen atom transfer (OAT) to triphenylphosphine under ultraviolet (UV) irradiation, as monitored by 1H and 19F NMR spectroscopies. Ultrafast transient absorption spectroscopy (TAS) identified the excited state(s) responsible for the photochemical OAT reaction or lack thereof. Competing sensitization pathways leading to excited-state deactivation in 2-Dy through energy transfer to the 4f electron manifold ultimately slows the OAT reaction at this metal cation. The measured rate differences between the open-shell Dy3+ and closed-shell Y3+ complexes demonstrate that using established principles of 4f ion sensitization may deliver new, selective modalities for differentiating the RE elements that do not depend on cation size.

17.
Org Biomol Chem ; 21(24): 5033-5039, 2023 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-37264923

RESUMEN

Two structurally diverse cyclic ß-hydroxy-α-nitrosulfones have been prepared and their isomerisation reactions studied. These cyclic ß-hydroxy-α-nitrosulfones undergo isomer equilibration via open-chain aldehyde forms under a variety of mild conditions. Michael condensation of 1,1'-[(1,3-dinitro-1,3-propanediyl)bis(sulfonyl)]bis(benzene) with propenal and subsequent cyclisation afforded 2,4-dinitro-2,4-bis(phenylsulfonyl)cyclohexanol in 98% yield as a mixture of four diastereomers. Sequential chromatography and recrystallization afford pure (1R,2R,4S)-rel-2,4-dinitro-2,4-bis(phenylsulfonyl)cyclohexanol based on spectroscopic and X-ray crystallographic data. This diastereomer equilibrates with the other three possible diastereomers under a variety of mild conditions: during silica gel chromatography, when dissolved in basic solution, and when dissolved in neutral polar solvents. Open-chain aldehyde forms are implicated as intermediates in isomer interconversion. Condensation of 1-methyl-4-[(nitromethyl)sulfonyl]benzene and pentanedial gives 2-(4-methylphenylsulfonyl)-2-nitrocyclohexane-1,3-diol as predominantly two diastereomers. Purification affords pure racemic diastereomer in 55% yield. This racemic diastereomer interconverts with several other isomers during silica gel chromatography. These isomers were identified as one, likely two, diastereomeric meso 2-(4-methylphenylsulfonyl)-2-nitrocyclohexane-1,3-diol isomers and four cyclic hemiacetal constitutional isomers. When dissolved in neutral polar solvents, the racemic diastereomer also interconverts with meso diastereomers and cyclic hemiacetals showing a marked solvent dependence. Reaction of the racemic diastereomer with triethylamine in dichloromethane results in isomerisation as well as substantial reversion to 1-methyl-4-[(nitromethyl)sulfonyl]benzene and pentanedial. Reaction with triethylamine in DMSO as well as simply warming in DMSO results in ring opening and concomitant dehydration to afford (E)-6-(4-methylphenylsulfonyl)-6-nitrohex-4-enal.

18.
Semin Perinatol ; 47(5): 151786, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37365044

RESUMEN

Historically, blood for admission laboratory studies in neonates was obtained through direct neonatal phlebotomy. Over the past decade there has been an increase in studies evaluating the validity and clinical impact of using a cord blood sample for many admission laboratory studies. This article reviews various studies that together have shown that using cord blood samples for admission testing in neonates is both acceptable and beneficial.


Asunto(s)
Procedimientos Médicos y Quirúrgicos sin Sangre , Cordocentesis , Recién Nacido , Humanos , Sangre Fetal
19.
Chem Sci ; 14(24): 6770-6779, 2023 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-37350823

RESUMEN

Iron compounds containing a bridging oxo or sulfido moiety are ubiquitous in biological systems, but substitution with the heavier chalcogenides selenium and tellurium, however, is much rarer, with only a few examples reported to date. Here we show that treatment of the ferrous starting material [(tBupyrpyrr2)Fe(OEt2)] (1-OEt2) (tBupyrpyrr2 = 3,5-tBu2-bis(pyrrolyl)pyridine) with phosphine chalcogenide reagents E = PR3 results in the neutral phosphine chalcogenide adduct series [(tBupyrpyrr2)Fe(EPR3)] (E = O, S, Se; R = Ph; E = Te; R = tBu) (1-E) without any electron transfer, whereas treatment of the anionic starting material [K]2[(tBupyrpyrr2)Fe2(µ-N2)] (2-N2) with the appropriate chalcogenide transfer source yields cleanly the isostructural ferrous bridging mono-chalcogenide ate complexes [K]2[(tBupyrpyrr2)Fe2(µ-E)] (2-E) (E = O, S, Se, and Te) having significant deviation in the Fe-E-Fe bridge from linear in the case of E = O to more acute for the heaviest chalcogenide. All bridging chalcogenide complexes were analyzed using a variety of spectroscopic techniques, including 1H NMR, UV-Vis electronic absorbtion, and 57Fe Mössbauer. The spin-state and degree of communication between the two ferrous ions were probed via SQUID magnetometry, where it was found that all iron centers were high-spin (S = 2) FeII, with magnetic exchange coupling between the FeII ions. Magnetic studies established that antiferromagnetic coupling between the ferrous ions decreases as the identity of the chalcogen is tuned from O to the heaviest congener Te.

20.
JCI Insight ; 8(9)2023 05 08.
Artículo en Inglés | MEDLINE | ID: mdl-37154155

RESUMEN

Chronic pain, whether of inflammatory or neuropathic origin, affects about 18% of the population of developed countries, and most current treatments are only moderately effective and/or cause serious side effects. Therefore, the development of novel therapeutic approaches still represents a major challenge. The Na,K-ATPase modulator FXYD2 is critically required for the maintenance of neuropathic pain in rodents. Here, we set up a therapeutic protocol based on the use of chemically modified antisense oligonucleotides (ASOs) to inhibit FXYD2 expression and treat chronic pain. We identified an ASO targeting a 20-nucleotide stretch in the FXYD2 mRNA that is evolutionarily conserved between rats and humans and is a potent inhibitor of FXYD2 expression. We used this sequence to synthesize lipid-modified forms of ASO (FXYD2-LASO) to facilitate their entry into dorsal root ganglia neurons. We established that intrathecal or intravenous injections of FXYD2-LASO in rat models of neuropathic or inflammatory pain led to a virtually complete alleviation of their pain symptoms, without causing obvious side effects. Remarkably, by using 2'-O-2-methoxyethyl chemical stabilization of the ASO (FXYD2-LASO-Gapmer), we could significantly prolong the therapeutic action of a single treatment up to 10 days. This study establishes FXYD2-LASO-Gapmer administration as a promising and efficient therapeutic strategy for long-lasting relief of chronic pain conditions in human patients.


Asunto(s)
Dolor Crónico , Neuralgia , Ratas , Humanos , Animales , Oligonucleótidos Antisentido/farmacología , Dolor Crónico/tratamiento farmacológico , Dolor Crónico/genética , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Oligonucleótidos , Neuralgia/tratamiento farmacológico , Enfermedad Crónica
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