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1.
Front Neurol ; 14: 1191761, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37475740

RESUMO

Objectives: Neuromyelitis optica spectrum disorder (NMOSD) and long-segment degenerative cervical myelopathy (DCM) may have a similar appearance on MRI. This study aimed to identify the differences in spinal cord gadolinium enhancement features between NMOSD and long-segment DCM. Methods: Spinal cord gadolinium enhancement of 27 NMOSD patients and 30 long-segment DCM patients were retrospectively analyzed. Enhancements were evaluated for their number, length, location on the sagittal images, distribution on the axial images, and form on the sagittal images. The Wilcoxon rank sum test was performed to compare numerical variables. The Pearson chi-squared test was performed to compare categorical variables. Results: The median number of enhanced lesions (p < 0.05), the median length of the enhancements (p < 0.05), and the location of enhancement on sagittal images (p < 0.05) of NMOSD patients and long-segment DCM patients showed significant differences. The axial distribution of enhancements did not show a significant difference between NMOSD and long-segment DCM patients (p = 0.115). On the sagittal images, linear and ring-formed enhancements were observed in 10 (27.0%) and 17 (63.0%) NMOSD patients, respectively. The enhancements in long-segment DCM patients had a transverse band or pancake-like appearance in 15 (50%) patients and an irregular flake-like appearance with a longitudinally oriented long axis in 15 patients (50%). Conclusion: By analyzing the number, length, location, and form of the gadolinium enhancements, NMOSD and long-segment DCM could be well-differentiated.

2.
J Org Chem ; 88(12): 7839-7843, 2023 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35763038

RESUMO

Highly enantioselective synthesis of 3,3'-spirooxindole γ-lactams with three contiguous stereocenters (two quaternary) was achieved. The aza-Michael/Mannich cascade reaction of α-imine-ß-oxobutanamides and methyleneindolinones catalyzed by a bifunctional diaminocyclohexane-derived thiourea catalyst gave the desired products in moderate to good yields (up to 78%), moderate to good diastereoselectivities (up to 10:1 dr), and good to excellent enantioselectivities (up to >99% ee). A gram-scale synthesis and some transformations of 3,3'-spirooxindole γ-lactams were also carried out.


Assuntos
Lactamas , Tioureia , Estereoisomerismo , Catálise
3.
Front Neurol ; 14: 1334976, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38348112

RESUMO

Objective: Charcot-Marie-Tooth (CMT) disease is the most common inherited neuromuscular disorder. Multi-echo Dixon MRI technique is a highly sensitive method for quantifying muscle fatty infiltration, which may provide excellent value for the assessment of CMT. Due to the rareness of the disease, its use in CMT disease has been rarely evaluated, especially in subtypes. Methods: Thirty-four CMT1 patients, 25 CMT2 patients, and 10 healthy controls were recruited. All of the recruited CMT1 patients are CMT1A with PMP22 duplication. Among CMT2 patients, 7 patients are CMT2A with MFN2 mutation, and 7 patients have SORD mutations. Multi-echo Dixon MRI imaging was performed. The fat fractions (FFs) of 5 muscle compartments of the leg were measured at proximal, middle, and distal levels by two specialized musculoskeletal radiologists. Comparisons between CMT1, CMT2, and genetically defined subtypes were conducted. Results: A proximal-distal gradient (27.6 ± 15.9, 29.9 ± 19.7, and 40.5 ± 21.4, p = 0.015) with a peroneal predominance (p = 0.001) in fat distribution was observed in CMT1. Significant differences in the soleus muscle FFs at proximal (19.1 ± 14.7 vs. 34.8 ± 25.1, p = 0.034) and medial levels (23.5 ± 21 vs. 38.0 ± 25.6, p = 0.044) were observed between CMT1 and CMT2 patients. Between PMP2 duplication and MFN2 mutation group, a significant difference in the soleus muscle FF was also observed (23.5 ± 21.0 vs. 54.7 ± 20.2, p = 0.039). Prominent correlations of calf muscle FFs with functional scores were observed. Discussion: Multi-echo Dixon MRI imaging is a valuable tool for assessing disease severity in CMT. The difference in patterns of fatty infiltration of CMT subtypes is first reported, which could provide references when making targeted training plans.

4.
Adv Healthc Mater ; 11(18): e2201139, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35815541

RESUMO

Optically monitoring hypochlorous acid (HClO) in living body favors diagnosis and study of inflammatory diseases. However, this has been hampered by limited strategies to develop highly fluorogenic tools in the deep-penetration near-infrared spectrum. Herein, a near-infrared aza-BODIPY-bisferrocene triad Fc2 -CBDP that unexpectedly achieves an exceptionally sensitive and selective fluorescence turn-on (>220-fold) response toward HClO through single-ferrocene oxidation and boron-alkynyl hydrolysis cascade is reported. Mechanism insight shows that Fc2 -CBDP features "enhanced charge transfer"-caused quenching due to intramolecular bisferrocene electronic coupling, which is decoupled in the reaction with HClO. The utility of Fc2 -CBDP for intracellular HClO imaging is evaluated and, more importantly, in vivo high-contrast deep-tissue imaging of lymphatic inflammation and colitis is realized. This work provides new insights into both HClO and ferrocene chemistry, and extends the reach of fluorogenic strategies in the near-infrared biosensing.


Assuntos
Corantes Fluorescentes , Ácido Hipocloroso , Boro , Compostos de Boro , Compostos Ferrosos , Corantes Fluorescentes/química , Ácido Hipocloroso/química , Metalocenos , Compostos Organofosforados
5.
RSC Adv ; 12(25): 15713-15717, 2022 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-35685709

RESUMO

A novel approach to synthesize chiral 1,2-oxazinane spirocyclic scaffolds by organocatalytic [4 + 2] cycloaddition reaction between methyleneindolinones and γ-aminooxy-α,ß-unsaturated ester has been disclosed. Furthermore, a hydrazide 1,4-synthon is designed and synthesized to construct chiral hexahydropyridazin spirocyclic scaffolds with methyleneindolinones via [4 + 2] cycloaddition reaction. Both reactions give corresponding products in good to excellent yield, excellent diastereoselectivity and good enantioselectivity.

6.
Org Biomol Chem ; 20(15): 3072-3075, 2022 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-35352074

RESUMO

The base-controlled dearomative [3 + 2] cycloaddition reaction between 3-nitroindoles and fumaric acid amide esters has been disclosed by using the dearomatization and aromatization strategy. Three kinds of diverse functionalized pyrrolo[2,3-b]indole derivatives were obtained respectively with excellent chemoselectivities and good diastereoselectivities using different bases.


Assuntos
Amidas , Indóis , Reação de Cicloadição , Ésteres , Fumaratos
7.
J Mater Chem B ; 10(17): 3268-3276, 2022 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-35357392

RESUMO

Heparins are natural and partially degraded polyelectrolytes that consist of sulfated polysaccharide backbones. However, as clinically used anticoagulants, heparins are associated with clinical bleeding risks and thus require rapid neutralization. Protamine sulfate is the only clinically approved antidote for unfractionated heparin (UFH), which not only may cause severe adverse reactions in patients, but also is only partially effective against low molecular weight heparins (LMWHs). We here present the facile synthesis of four porous multicationic dynamic covalent polymers (DCPs) from the condensation of tritopic aldehyde and acylhydrazine precursors. We show that, as new water-soluble polymeric antidotes, the new DCPs can effectively include both UFH and LMWHs and thus reverse their anticoagulating activity, which is confirmed by the activated partial thromboplastin time and thromboelastographic assays as well as mouse tail transection assay (bleeding model). The neutralization activities of two of the DCPs were found to be overall superior to that of protamine and have wider concentration windows and good biocompatibility. This pore-inclusion neutralization strategy paves the way for the development of water-soluble polymers as universal heparin binding agents.


Assuntos
Anticoagulantes , Heparina , Animais , Anticoagulantes/farmacologia , Anticoagulantes/uso terapêutico , Hemorragia/induzido quimicamente , Hemorragia/tratamento farmacológico , Heparina/química , Heparina/farmacologia , Heparina de Baixo Peso Molecular/farmacologia , Humanos , Camundongos , Polímeros/química , Polímeros/farmacologia , Porosidade , Água
8.
Eur Radiol ; 32(6): 3855-3862, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35084519

RESUMO

OBJECTIVES: To evaluate the feasibility of proximal nerve MR neurography with diffusion tensor imaging (DTI) for differentiating Charcot-Marie-Tooth (CMT) 1A, CMT2, and healthy controls. METHODS: The diameters, fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) of L4-L5 nerve roots, femoral nerve (FN), and sciatic nerve (SN) were compared. Receiver operating characteristic (ROC) curve analyses were conducted to evaluate the diagnostic performance. DeLong's tests were applied to compare multiple ROC curves. Intraclass correlation coefficients were calculated for interobserver agreement assessment. RESULTS: The diameters of the L4 nerve root, L5 nerve root, and SN of CMT1A patients were significantly larger than those of CMT2 patients and healthy controls. The FA values of all measured proximal nerves were significantly higher in controls (0.46 ± 0.09, 0.46 ± 0.08, 0.45 ± 0.07, and 0.48 ± 0.08) than in CMT1A patients (0.30 ± 0.09, 0.29 ± 0.06, 0.35 ± 0.08, and 0.29 ± 0.09). The FA values of the L5 nerve root, FN, and SN were significantly higher in controls (0.46 ± 0.08, 0.45 ± 0.07, and 0.48 ± 0.08) than in CMT2 patients (0.36 ± 0.06, 0.34 ± 0.07, and 0.34 ± 0.10). The MD and RD values of the L5 nerve root in CMT1A patients (1.59 ± 0.21 and 1.37 ± 0.21) were higher than those in CMT2 patients (1.31 ± 0.17 and 1.05 ± 0.14). The AUCs of the above parameters ranged from 0.780 to 1.000. For the measurements of nerve diameters, the ICC ranged from 0.91 to 0.97. For the measurements of DTI metrics, the ICC ranged from 0.87 to 0.97. CONCLUSIONS: MR neurography with DTI is able to differentiate CMT1A patients, CMT2 patients, and healthy controls. KEY POINTS: • MR neurography with diffusion tensor imaging of the L4-5 nerve roots, proximal femoral nerve, and proximal sciatic nerve is able to discriminate CMT1A, CMT2, and healthy controls. • This method provides an alternative for the diagnosis and discrimination of CMT1A and CMT2, which is crucial for clinical management.


Assuntos
Doença de Charcot-Marie-Tooth , Imagem de Tensor de Difusão , Anisotropia , Doença de Charcot-Marie-Tooth/diagnóstico por imagem , Imagem de Tensor de Difusão/métodos , Humanos , Estudos Prospectivos , Nervo Isquiático/diagnóstico por imagem
9.
Org Lett ; 23(12): 4579-4583, 2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34061550

RESUMO

A novel, practical, highly efficient, and transition metal free nitrogen insertion reaction for the synthesis of 2,3-disubstituted quinazolinone derivatives was developed. Diverse functionalized 3-indolinone-2-carboxylates and nitrosoarenes with a wide range of substituted nitrosobenzenes, nitrosopyridines, dibenzofuranyl, or dibenzothienyl nitroso compounds worked smoothly to give 2,3-disubstituted quinazolinone derivatives in good to excellent yields (69-98%). A gram-scale reaction was achieved, and an afloqualone analogue was synthesized under the mild reaction conditions.

10.
Org Lett ; 22(9): 3351-3355, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32281799

RESUMO

A simple, direct, and highly enantioselective synthesis of spiro-oxindole piperidin-2-one derivatives was achieved through an aza-Michael/Michael cyclization cascade sequence using a squaramide catalyst. The desired products were obtained in excellent yields (up to 99%) and good to high stereoselectivities (up to >20:1 dr and up to 99% ee) under mild conditions.


Assuntos
Compostos de Espiro , Ciclização , Oxindóis , Piperidonas , Estereoisomerismo
11.
ACS Macro Lett ; 9(1): 90-95, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35638654

RESUMO

Two metal porous organic polymers (POPs) that contain the [Ru(bpy)3]2+ cores are prepared via one-pot Suzuki-Miyaura coupling reactions. Both Ru-POPs are thermally stable at up to 340 °C in air and do not dissolve in all solvents tested. One of the POPs has been revealed to be highly effective and reusable as a heterogeneous photocatalyst for visible light-driven enantioselective alkylation of aldehydes. After 10 cycles, the catalyst still maintains the enantioselectivity, while the activity just decreases slightly.

12.
Chem Commun (Camb) ; 55(86): 12988-12991, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31603439

RESUMO

Herein, we report stoichiometric investigations embodying the first highly enantioselective aryl-aryl coupling facilitated by a gold complex. With up to 91% ee, this is the first demonstration of a transmetalation and C(sp2)-C(sp2) reductive elimination sequence with high enantioselectivity using a gold complex. The results offer a basis for development of enantioselective gold-catalyzed aryl-aryl coupling reactions.

13.
J Clin Imaging Sci ; 9: 26, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31448177

RESUMO

Pneumocephalus is a rare presentation of sinusitis. The purpose of this case series and literature review is to highlight the critical importance of recognizing pneumocephalus on initial brain imaging, since it may serve as the first sign of acute sinusitis with intracranial complication. Although sinusitis is a treatable condition with appropriate and timely antibiotic therapy, failure to recognize intracranial extension and delays to prompt surgical drainage could lead to a dire clinical course.

14.
J Org Chem ; 83(20): 12838-12846, 2018 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-30207727

RESUMO

A series of chiral spiroketal bisphosphine ligands containing 1,1'-spirobi(3 H,3' H)isobenzofuran backbones was accessed through asymmetric synthesis and subsequently tested in enantioselective Rh-catalyzed hydrogenation of α-dehydroamino acid esters. The ligand providing the highest enantioselectivity (up to 99.5%) was obtained in seven steps in an overall 38% yield. The synthesis could be performed on a gram scale, and no kinetic resolution of enantiomers is required. Overall, the developed ligand provides an easily accessible alternative to SDP ligands as well as other chiral bisphosphine ligands.

15.
Org Lett ; 20(10): 2888-2891, 2018 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-29733613

RESUMO

The highly enantioselective preparation of spirooxindoles bearing α,α-disubstituted α-amino-ß-keto esters was achieved through [4 + 1] annulation of oxindoles and α-imine-ß-oxo-γ,δ-unsaturated esters under mild conditions in good yields (up to 82%) and stereoselectivities (up to >20:1 dr, 96% ee). The reaction is amenable to gram scale synthesis using catalyst loading as low as 1 mol %. The corresponding chiral α,α-disubstituted α-amino-ß-keto esters could be easily transformed into cyclopenta[ b]indole derivatives without erosion of enantiopurity.

16.
Chem Asian J ; 12(12): 1309-1313, 2017 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-28474489

RESUMO

An asymmetric route to (-)-α-lycorane and (-)-zephyranthine, and a formal total synthesis of (+)-clivonine were achieved. A pivotal intermediate, which serves as a potent precursor for the divergent syntheses of these natural products, was accessed by a diastereoselective Pd-catalyzed cinnamylation of an N-tert-butanesulfinyl imine.


Assuntos
Alcaloides/síntese química , Alcaloides de Amaryllidaceae/síntese química , Fenantridinas/síntese química , Alcaloides/química , Alcaloides de Amaryllidaceae/química , Cristalografia por Raios X , Modelos Moleculares , Estrutura Molecular , Fenantridinas/química , Estereoisomerismo
17.
Chem Commun (Camb) ; 53(25): 3520-3523, 2017 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-28243660

RESUMO

Highly diastereoselective palladium catalyzed cinnamylation of N-tert-butanesulfinyl imines with cinnamyl acetates has been established to provide enantioenriched ß-aryl homoallylic amines. The synthetic application of this stragety has been successfully demonstrated in the concise total syntheses of antitumor natural products (+)-lycoricidine and (+)-7-deoxypancratistatin.

18.
J Gastroenterol Hepatol ; 32(8): 1463-1468, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28087973

RESUMO

BACKGROUND AND AIMS: Mesenteric lymph nodes were usually removed during bowel resection surgery for Crohn's disease (CD). Mesenteric lymph node (MLN) granuloma predicted postoperative disease recurrence in patients with CD after ileocolic resection (ICR). This study was aimed to identify factors associated with MLN granulomas in a cohort of CD patients who underwent ICR. METHODS: The study group consisted of 18 patients with CD who underwent the index ICR between 2004 and 2012 and had MLN granulomas. The control group included 32 cases negative for MLN granulomas, which were randomly selected from the same period. Clinicodemographic and histological features were compared in these two groups. RESULTS: The presence of MLN granuloma was associated with younger age, perianal disease, and ileocolic disease. Gender, body mass index, smoking status, disease duration, extraintestinal manifestation, length of bowel resected, total number of nodes examined, medical treatment, and indications for surgery were not significantly different between the groups. The presence of MLN granuloma was associated with mural granuloma, transmural inflammation, mural abscess, hypertrophy of the muscularis propria, fibrosis of the muscularis propria, and serosal fibrosis in the small bowel. The multivariable analysis confirms that MLN granuloma was associated with age and transmural inflammation. CONCLUSIONS: In CD patients who underwent the index ICR, the presence of MLN granuloma was associated with younger age and transmural inflammation. Our current results suggest that the detection of MLN granulomas may be enhanced in patients at higher risk, that is, younger patients or those with transmural inflammation on imaging or histopathology.


Assuntos
Fatores Etários , Doença de Crohn/etiologia , Doença de Crohn/cirurgia , Granuloma/etiologia , Linfonodos , Doenças Linfáticas/etiologia , Mesentério , Adulto , Idoso , Estudos de Coortes , Colectomia , Feminino , Granuloma/cirurgia , Humanos , Íleo/cirurgia , Inflamação , Doenças Linfáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Recidiva , Fatores de Risco , Adulto Jovem
19.
Org Biomol Chem ; 15(4): 778-781, 2017 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-27808321

RESUMO

A Michael-Mannich-hemiaminalization-dehydration cascade reaction was developed for the construction of spirooxindole benzoquinolizine derivatives. Additionally, spirooxindole benzoindolizidine was prepared conveniently through a ring-contracted rearrangement reaction from spirooxindole benzoquinolizine.

20.
Org Lett ; 18(9): 1996-9, 2016 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-27064857

RESUMO

The practical asymmetric synthesis of amathaspiramides B, D, and F has been accomplished by utilizing an aza-Barbier allylation as the key step to construct the common intermediate with two adjacent stereocenters. A kinetically controlled cyclization to build the challenging thermodynamically less stable 8R-hemiaminal moiety is also important in the synthesis of amathaspiramide D. The route is readily scalable, and gram quantity of the final product D has been prepared.

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