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This study elucidates the mechanisms and principles governing chemoselectivity in synthesizing two distinct N-heterocycles, benzimidazole thiazine and benzothiazole imidazole, through BF3â¢OEt2-catalyzed cyclization reactions of propargyl alcohols with benzimidazole thiols. Employing density functional theory calculations, we highlight the crucial role of fluorine source in influencing chemoselectivity. In DCM, BF3, as the catalytic center, coordinates with propargyl alcohol's hydroxyl group to form a precursor. Conversely, in DMF, [BF2â¢DMF]+, formed from DMF and BF3â¢OEt2, acts as the catalytic center, activating the propargyl alcohol's hydroxyl group. The mechanisms in both solvents involve sequential steps: B-O bond formation, C-O bond cleavage, S-C bond formation, hydrogen atom transfer (HAT), cyclization, and deprotonation. A notable difference is the HAT process: in DCM, it follows a 1,5-HAT process, while in DMF, BF4- formation from DMF and BF3â¢OEt2 provides a fluorine source and introduces steric hindrance, favoring a 1,6-HAT process and leading to unique chemoselectivity. This pioneering research showcases the impact of DMF on cyclization reactions, offering valuable insights for comprehending and designing reactions driven by fluorine sources. Crucially, our results propose an innovative reaction mechanism featuring lower potential energy surfaces, enhancing our understanding of the intricate interplay among reactants, catalysts, and solvents.
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Meibomian glands (MGs) are vital for ocular surface health. However, the roles of inflammation in the progression of meibomian gland dysfunction (MGD) are largely unknown. In this study, the roles of the inflammation factor interleukin-1ß (IL-1ß) via the p38 mitogen-activated protein kinases (MAPK) signaling pathway on rat meibomian gland epithelial cells (RMGECs) were explored. Eyelids from adult rat mice at 2 months and 2 years of age were stained with specific antibodies against IL-1ß to identify inflammation levels. RMGECs were exposed to IL-1ß and/or SB203580, a specific inhibitor of p38 MAPK signaling pathway, for 3 days. Cell proliferation, keratinization, lipid accumulation, and matrix metalloproteinases 9 (MMP9) expression were evaluated by MTT assay, polymerase chain reaction (PCR), immunofluorescence staining, apoptosis assay, lipid staining, and Western blot analyses. We found that IL-1ß was significantly higher in the terminal ducts of MGs in rats with age-related MGD than in young rats. IL-1ß inhibited cell proliferation, suppressed lipid accumulation and peroxisome proliferator activator receptor γ (PPARγ) expression, and promoted apoptosis while activating the p38 MAPK signaling pathway. Cytokeratin 1 (CK1), a marker for complete keratinization, and MMP9 in RMGECs were also up-regulated by IL-1ß. SB203580 effectively diminished the effects of IL-1ß on differentiation, keratinization, and MMP9 expression by blocking IL-1ß-induced p38 MAPK activation, although it also inhibited cell proliferation. The inhibition of the p38 MAPK signaling pathway blocked IL-1ß-induced differentiation reduction, hyperkeratinization, and MMP9 overexpression of RMGECs, which provides a potential therapy for MGD.
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Glândulas Tarsais , Proteínas Quinases p38 Ativadas por Mitógeno , Ratos , Camundongos , Animais , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Glândulas Tarsais/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Metaloproteinase 9 da Matriz/metabolismo , Interleucina-1beta/farmacologia , Interleucina-1beta/metabolismo , Células Epiteliais/metabolismo , Inflamação/metabolismo , LipídeosRESUMO
Blepharospasm patients often have dry eye manifestations. Botulinum neurotoxin type A (BoNT-A) injection has been the main management for blepharospasm and absorbable punctal plug (APP) insertion is shown to be effective in the treatment of dry eye. However, there have been no studies investigating the combined treatment of BoNT-A and APP in blepharospasm patients with dry eye. In this retrospective study, 17 blepharospasm patients with dry eye treated by BoNT-A injection and 12 receiving BoNT-A plus APP treatment were enrolled. The efficacy was evaluated according to the Jankovic rating scale, Ocular Surface Disease Index (OSDI), fluorescein staining (FL), fluorescein tear break-up time (FBUT) and Schirmer I test (SIT). Both BoNT-A and BoNT-A+APP treatment effectively reduced the functional impairment of blepharospasm. At baseline, all the patients had high OSDI scores (BoNT-A group: 82.48 ± 7.37, BoNT-A+APP group: 78.82 ± 4.60, p = 0.112), but relatively low degrees of FL (BoNT-A group: 3.18 ± 1.01, BoNT-A+APP group: 3.50 ± 1.24, p = 0.466), FBUT (BoNT-A group: 1.71 ± 0.77, BoNT-A+APP group: 2.17 ± 0.58, p = 0.077) and SIT (BoNT-A group: 2.53 ± 0.99, BoNT-A+APP group: 3.17 ± 1.23, p = 0.153). After treatment, OSDI, FL, FBUT and SIT were all obviously restored in the two groups. When comparing the changing rates, only OSDI (BoNT-A group: -52.23% ± 15.57%, BoNT-A+APP group: -61.84% ± 9.10%, p = 0.047) and FL (BoNT-A group: -22.55% ± 25.98%, BoNT-A+APP group: -41.94% ± 14.46%, p = 0.016) showed significant differences between the two groups. This study suggests that OSDI is not applicable in the diagnosis of dry eye among blepharospasm patients. For blepharospasm patients with severe dry eye symptoms, especially those with fluorescein staining in the cornea, the combined treatment of BoNT-A and APP is more effective than using BoNT-A alone.
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PURPOSE: To report a 10-year follow-up case of the first lamellar keratoplasty treatment with acellular porcine corneal stroma (APCS). METHODS: A 62-year-old woman was diagnosed with a fungal corneal ulcer and received lamellar keratoplasty treatment with APCS in 2010. The 10-year follow-up results were evaluated by slit lamp biomicroscopy, anterior segment optical coherence tomography, in vivo confocal microscopy, and corneal biomechanics analysis. RESULTS: The APCS graft maintained good biocompatibility and physical properties in transparency, stromal regeneration, elasticity, and deformation resistance. However, some disadvantages were observed, including a protracted course to eventual clearing, a decreased thickness, corneal depositions, sparsely distributed neural fibers, and low stiffness. CONCLUSIONS: This case indicated that APCS remains stable over a 10-year follow-up period. APCS can serve as a functional stromal surrogate where donor human corneal tissue is unavailable.
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Transplante de Córnea , Úlcera da Córnea , Animais , Córnea/cirurgia , Substância Própria/transplante , Transplante de Córnea/métodos , Úlcera da Córnea/cirurgia , Seguimentos , Humanos , Suínos , Tomografia de Coerência ÓpticaRESUMO
Currently, the aquatic environment of the Tuojiang River basin in Sichuan Province is severely polluted by non-point sources of total nitrogen (TN). This study adopts the pollution discharge coefficient method to estimate the TN pollution load of non-point sources in this watershed during 2007-2017. The temporal and spatial distribution and transfer trends of the TN pollution load in the Tuojiang River basin were examined, based on center-of-gravity statistical and spatial analysis technology. This study aimed to provide an accurate theoretical basis for the prevention and early identification of non-point source pollution in the Tuojiang River basin. The results indicate that livestock breeding was the main non-point source of TN pollution and contributed more than 45% to the TN pollution load during 2007-2017. The contribution rate of rural life and domestic waste decreased continually during the study period, whereas that of farmland solid waste and farmland runoff exhibited an increasing trend. The total pollution load of TN exhibited a decreasing trend during 2007-2017. The maximum and minimum TN pollution loads occurred in 2010 and 2017 with values of 5.7×104 t and 4.69×104 t, respectively. Spatial heterogeneity of the pollution load, together with the uneven distribution of rainfall runoff, caused a shift from northwest to southeast in the pollution-load centers of gravity for livestock and poultry breeding, farmland solid waste, and farmland runoff. Southeast of the watershed is the key area for prevention and control of these pollution sources. A shift in the centers of gravity for rural living and household waste pollution, from southeast to northwest, was attributed to agricultural populations transforming to urban populations in the southeastern counties. The maximum transfer range was 66.35 km2, and this minimum boundary circle is the key identification area of pollution source pollution load change. Northwest of Tuojiang River basin is the key area in which TN pollution from rural living and rural household waste can be prevented. This research expands the methods for exploring the temporal and spatial evolution of pollution load in the Tuojiang River basin, which is of great significance for improving the aquatic environment and promoting sustainable development of the basin economy.
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Poluição Difusa , Poluentes Químicos da Água , China , Monitoramento Ambiental , Nitrogênio/análise , Fósforo/análise , Rios , Poluentes Químicos da Água/análiseRESUMO
Purpose: Meibomian glands play a vital role in maintaining ocular surface stability. This study aimed to investigate whether Hedgehog signaling is involved in the regulation of meibomian gland epithelial cells. Methods: Rat meibomian glands epithelial cells (RMGECs) were isolated from ducts and ductules, and then were cultivated to passage two on Matrigel coated wells in meibomian gland epithelial cells medium (MGECM). Cells were switched from MGECM to differentiation medium (DM) or DM added 10 µg/mL azithromycin (DM + AZM) when reached 50% to 60% confluence. The effects of the Smoothened (Smo) agonist (Smo agonist [SAG]) and antagonist (by cyclopamine) on RMGECs were analyzed using quantitative RT-PCR, cell proliferation analysis, immunofluorescence staining, and Nile red staining. Results: The Hedgehog receptor, Smo, and its downstream molecules, Glis, were expressed both in vivo and in vitro. Smo and Gli1 both decreased with the increase of differentiation in vitro. Smo antagonist, cyclopamine, reduced cell numbers, and the expression of Ki67 in MGECM, and promoted the expression of SREBP1 and lipid production in DM + AZM. Smo agonist, SAG, inhibited the expression of SREBP1 and lipid accumulation in DM + AZM but showed no significant effects on raising cell numbers and the expression of Ki67 in MGECM. Conclusions: The Hedgehog signaling pathway appears to play important roles in RMGECs proliferation and differentiation. This may provide a potential therapeutic way to treat meibomian gland dysfunction (MGD).
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Células Epiteliais/metabolismo , Proteínas Hedgehog/genética , Disfunção da Glândula Tarsal/genética , Glândulas Tarsais/metabolismo , Animais , Contagem de Células , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Modelos Animais de Doenças , Células Epiteliais/patologia , Proteínas Hedgehog/metabolismo , Masculino , Disfunção da Glândula Tarsal/metabolismo , Disfunção da Glândula Tarsal/patologia , Glândulas Tarsais/patologia , Ratos , Ratos Sprague-Dawley , Transdução de SinaisRESUMO
Rat limbal niche cells (LNCs) have been proven to induce transdifferentiation of oral mucosal epithelial cells (OMECs) into corneal epithelial-like cells termed transdifferentiated oral mucosal epithelial cells (T-OMECs). This investigation aimed to evaluate the effect of subconjunctival T-OMEC injections on alkali-induced limbal stem cell deficiency (LSCD) in rats. LNCs were cocultured with OMECs in the Transwell system to obtain T-OMECs, with NIH-3T3 cells serving as a control. Subconjunctival injection of single T-OMEC or OMEC suspension was performed immediately after corneal alkali injury. T-OMECs were prelabeled with the fluorescent dye CM-DiI in vitro and tracked in vivo. Corneal epithelial defect, opacity, and neovascularization were quantitatively analyzed. The degree of corneal epithelial defect (from day 1 onward), opacity (from day 5 onward), and neovascularization (from day 2 onward) was significantly less in the T-OMEC group than in the OMEC group. Cytokeratin 12 (CK12), pigment epithelium-derived factor, and soluble fms-like tyrosine kinase-1 were expressed at a higher rate following T-OMEC injection. Some CM-DiI-labeled cells were found to be coexpressed with CK12, Pax6, and ΔNp63α in the corneal epithelium after subconjunctival injection. Subconjunctival injection of T-OMECs prevents conjunctival invasion and maintains a normal corneal phenotype, which might be a novel strategy in the treatment of LSCD.
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Transplante de Células , Células Epiteliais/citologia , Limbo da Córnea/patologia , Mucosa Bucal/citologia , Células-Tronco/patologia , Animais , Células Cultivadas , Corantes Fluorescentes/química , Masculino , Camundongos , Células NIH 3T3 , Ratos , Ratos Sprague-Dawley , Transplante HomólogoRESUMO
Purpose: Limbal niche cells (LNCs) play a vital role in the maintenance of limbal epithelial stem/progenitor cells (LESCs). Four methods have been reported to isolate and expand LNCs: digestion by collagenase alone (C-LNC), collagenase following dispase removal of the limbal epithelium (DC-LNC), dissection of dispase-isolated limbal epithelial sheets (D-LNC), and explant cultures of limbal stromal tissues (Ex-LNC). This study aimed to isolate LNCs using those four methods and to compare their capacity to maintain LESCs. Methods: LNCs were isolated from the rat corneal limbus by the following methods: C-LNC, DC-LNC, D-LNC, and Ex-LNC. Quantitative real-time PCR and immunofluorescence staining were used to analyze the expression of embryonic stem cell (ESC) markers. The ability to maintain LESCs was assessed on the basis of colony-forming capacity and the expression of progenitor, proliferation, and differentiation markers in three-dimensional (3D) Matrigel and Transwell systems. Notch signaling of LESCs supported by different LNCs in Transwell inserts was analyzed by quantitative real-time PCR. Results: DC-LNCs exhibited lower expression of CK12 during isolation and expansion. Among P4-expanded LNCs, DC-LNCs expressed significantly higher levels of Sox2, Oct4, Nanog, and N-cadherin than C-LNCs, D-LNCs, and Ex-LNCs. Compared with other LNCs, DC-LNCs were more effective in maintaining LESCs with higher holoclone-forming efficiency, greater expression of ΔNp63α and Ki67, and lower expression of CK12. DC-LNCs were also more capable of downregulating Notch signaling of LESCs. Conclusions: DC-LNCs were more effective in expressing ESC markers and maintaining LESCs compared to other LNCs. This study identifies an optimal method for the isolation of LNCs in tissue engineering and ocular surface reconstruction.
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Limbo da Córnea/citologia , Animais , Células Cultivadas , Técnicas de Cocultura , Colagenases , Imunofluorescência , Limbo da Córnea/cirurgia , Masculino , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Nicho de Células-Tronco , Células-Tronco/citologiaRESUMO
A simple and practical method for the synthesis of phosphoryl-substituted indolo[2,1-a]isoquinolin-6(5H)-ones and benzimidazo[2,1-a]isoquinolin-6(5H)-ones through manganese(iii)-promoted tandem phosphinoylation/cyclization of 2-arylindoles or 2-arylbenzimidazoles with disubstituted phosphine oxides was developed. In this transformation, new C-P bond and C-C bond were constructed simultaneously under silver-free conditions, exhibiting a broad substrate scope. It was noted that not only diarylphosphine oxides but also dialkyl and arylalkyl-phosphine oxides were compatible with the conditions.
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A copper-catalyzed C-H [3 + 2] annulation of N-substituted anilines with α-carbonyl alkyl bromides for the synthesis of 3,3'-disubstituted oxindoles is developed. Tandem C-H cycloamidation reactions of various α-carbonyl alkyl bromide derivatives including tertiary-α-bromoalkyl ketone esters, malonic esters and cycloalkanes, with N-aryl or alkyl substituted anilines, can be performed using this system, affording a vast array of valuable 3,3'-disubstituted oxindoles in moderate to good yields.