OBJECTIVE Studies on the Drug-loading Property and Adsorption Mechanism of Starch Microsphere for ciprofloxacin.METHODS The starch-based microsphere that was crosslinked with epichlorohydrion using a water-in-oil emulsification was prepared.The ciprofloxacin-loaded starch microsphere was made by adsorption method.The drug-loading rate and embedding capacity are mesured by UV spectrum,then the effect of drug quantity,adsorption time,temperature on the drug-loading rate and the adsorption mechanism were investigated.The thermodynamic parameters of starch microsphere adsorpting ciprofloxacin was determined.RESULTS The results show adsorption quantity is more than 100mg·g-1 while entrapment rate is above 60%,the adsorption isotherm can be described as Q=20.36Ce1.73,the enthalpy change is-18.82 kJ·mol-1,the entropy change is-22.65 J/mol·K-1.CONCLUSION The Starch Microsphere can be used as carrier of ciprofloxacin,the main adsorption methanism for ciprofloxacin is the physical adsorption.
One-week old wheat seedlings were treated by chitosan with different molecular weights.The application of chitosan to wheat leaf caused accumulations of H2O2 and total phenolic contents,and increased activities of peroxidase and phenylalanine ammonia-lyase.The induction activity of chitosan was dependent on its molecular weight and time after treatment.Low molecular weight chitosan showed much higher induction activity than high molecular weight chitosan.
To investigate whether protein regulator of cytokinesis 1 (PRC1), which is involved in the regulation of human carcinogenesis, contributes to poor prognosis in patients with cholangiocarcinoma (CCA).Data and tissues from patients with CCA were retrospectively studied. Immunohistochemical staining and western blotting were used to evaluate and contrast the PRC1 expression profile at the protein level in CCA tumour and pericarcinomatous tissues from the same study population. Relationships between clinical characteristics and patient survival were observed using univariate and multivariate analyses. Correlations between PRC1 expression and clinical characteristics were analysed by logistic regression.A total of 45 patients were included. PRC1 expression was found to be upregulated in CCA cancer tissues versus pericarcinomatous tissues. Overexpression of PRC1 was shown to be related to tumour differentiation, tumour node metastasis staging and lymph node metastasis, and was also revealed to be an independent marker of poor CCA prognosis.The present results suggest that PRC1 may be a prognostic and therapeutic biomarker for patients with CCA.
To determine the epithelial lineage of origin in corneal pannus tissue surgically removed from patients with total limbal stem cell (SC) deficiency.The lineage of origin of the entire conjunctivalized pannus removed from eight corneas with a diagnosis of total limbal SC deficiency was characterized by anti-keratin (K)-3 and anti-K19 monoclonal antibodies. The protein and mRNA of epithelial outgrowth from segments of five such pannus specimens were analyzed by Western blot and reverse transcription-polymerase chain reaction, respectively.Cross sections of all eight specimens showed a stratified epithelium with goblet cells expressing mucin (MUC)-5AC, and a stroma showing blood vessels and inflammatory cell infiltrates. Immunostaining showed full-thickness expression of K19 in the entire pannus of all eight specimens. Expression of K3 was negative in seven patients, but was sporadically positive in a patient with Stevens-Johnson syndrome. In culture, all five pannus specimens generated a compact, small epithelial cell outgrowth, and except for one, reached confluence in 2 to 3 weeks. The K3/K12 pair was expressed by extracts of cell outgrowth from the control limbal epithelial explant, but not in all five pannus specimens. A 60-kDa band of DeltaNp63 was expressed in the control specimen and in all five pannus specimens. Cell outgrowth expressed K3 transcript in three, but none showed K12 transcript.The resultant epithelial phenotype of the pannus tissue was not corneal, as evidenced by the negative staining to cornea-specific K12 mRNA and protein, but was conjunctival, as evidenced by the presence of goblet cells, the weak expression of K3, and the strong expression of K19. The abundant expression of DeltaNp63 in such conjunctiva-derived epithelium in eyes with total limbal SC deficiency raises doubts as to its validity as a limbal SC marker.
purpose. Squamous metaplasia is a pathologic process that frequently occurs in nonkeratinized stratified ocular surface epithelia. The mechanism for this occurrence is largely unknown except for vitamin A deficiency. methods. Human limbal explants were cultured under airlift with or without p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580 or in a submerged manner for different durations up to 2 weeks. Epithelial cell proliferation, differentiation, limbal stem cell maintenance, and expansion were studied using certain markers such as Ki67, p63, K10 and K12 keratins, filaggrin, Pax6, ABCG-2, and Musashi-1. Expression of phospho-p38 MAPK and its downstream transcription factors, C/EBPα and C/EBPβ, were studied by immunohistochemistry. Epithelial cells harvested from explants after 2 weeks of culturing under different conditions were seeded onto 3T3 feeder layers and cultured for 12 days. The differentiation of clonal epithelial cells was investigated by double staining to K12 and K10 keratins. results. The squamous metaplasia model was successfully created by culturing human limbal explants at an air-liquid interface (airlift) for 2 weeks. Increased stratification and hyperproliferation only happened in the limbal, but not the corneal, epithelium in airlift, but not submerged, cultures. Epithelial proliferation was associated with a transient increase of limbal epithelial stem cells. Abnormal epidermal differentiation—evidenced by positive expression of K10 keratin in suprabasal cells and filaggrin in superficial cells—ensued. Clones generated from epithelial cells harvested from airlift culture only expressed K12 keratin without K10. As early as 2 days in airlift cultures, p38 expression emerged in limbal basal epithelial cells and gradually extended to the cytoplasm and nuclei. Furthermore, addition of the p38 inhibitor SB203580 abolished abnormal epidermal differentiation without affecting limbal epithelial proliferation. Expression of C/EBPα and C/EBPβ, downstream of the p38 MAPK signaling pathway, was strongly induced by airlift culture and partially was inhibited by SB203580. conclusions. Dryness resulting from exposure activates p38 MAPK signaling coupled with abnormal epidermal differentiation without intrinsic alteration of stem cells in the limbus. On the ocular surface, p38 inhibitors may have the potential to revert the pathologic process of squamous metaplasia induced by dryness.
Differential chromatin accessibility accompanies and mediates transcriptional control of diverse cell fates and their differentiation during embryogenesis. While the critical role of NKX2-1 and its transcriptional targets in lung morphogenesis and pulmonary epithelial cell differentiation is increasingly known, mechanisms by which chromatin accessibility alters the epigenetic landscape and how NKX2-1 interacts with other co-activators required for alveolar epithelial cell differentiation and function are not well understood. Here, we demonstrate that the paired domain zinc finger transcriptional regulators PRDM3 and PRDM16 regulate chromatin accessibility to mediate cell differentiation decisions during lung morphogenesis. Combined deletion of
Keratocytes in the corneal stroma express keratan sulfate-containing proteoglycans including cornea-specific keratocan. On plastic dishes, human, bovine, and rabbit keratocytes lose their characteristic dendritic morphology and keratocan expression when cultured in serum-containing media. Herein, we demonstrated that murine keratocytes also acquired a fibroblastic shape and lost keratocan expression after first passage when cultured on plastic in the presence of serum. In contrast, cells expanded on human amniotic membrane (AM) stromal matrix maintained a three-dimensional dendritic morphology and expressed keratocan mRNA and protein for at least 8 passages before senescence. When keratocytes were cultured on AM, the promoter activity of transforming growth factor (TGF)-beta2 and TGF-beta receptor II was down-regulated as compared with that on plastic. Furthermore, cells on AM continuously retained Smad 2 and Smad 4 in the cytoplasm and did not express alpha-smooth muscle actin, even when 10 ng/ml TGF-beta1 was added in a serum-free medium for up to 5 days. In parallel to such down-regulation of TGF-beta signaling, keratocan promoter-driven ECFP expression was observed in cells cultured either on AM in the presence of serum or on plastic containing serum treated with a neutralizing antibody to TGF-beta. Collectively, these results indicate that down-regulation of Smad-mediated TGF-beta signaling is an important mechanism for cultured keratocytes to maintain a normal phenotype while continuously expanded in a serum-containing medium. This strategy of suppressing TGF-beta signaling, achieved by AM stromal matrix in part via suppression of TGF-beta gene transcription, can be used to expand keratocytes in culture without the use of AM in the future.
Objective: To explore the relationship between clinical nurses' psychological capital, compassion fatigue with work engagement, and analyze the mediating effect of psychological capital between compassion fatigue and work engagement, so as to provide scientific evidence for reducing compassion fatigue and improving work engagement of clinical nurses. Methods: From December 2021 to February 2022, 494 clinical nurses from 7 general hospitals in Sichuan Province were selected for the study using convenience sampling. The General Information Questionnaire, the Compassion Fatigue Short Scale, the Work Engagement Short Scale and the Psychological Capital Questionnaire for Nurses were used to conduct the survey. Pearson correlation was used to analyze the correlation between compassion fatigue, work engagement and psychological capital. And stepwise regression analysis and Bootstrap method were used to analyze the effects of compassion fatigue and psychological capital on work engagement as well as the mediating effect of psychological capital between compassion fatigue and work engagement. Results: Of the 494 clinical nurses, 33 (6.7%) were male and 461 (93.3%) were female, with an average age of (31.47±6.89) years old and an average working years (9.87±7.61) years. The average scores of psychological capital, compassion fatigue and work engagement of clinical nurses were (5.01±0.76), (3.19±2.08) and (4.60±1.37) points, respectively. Compassion fatigue was negatively correlated with psychological capital and work engagement (r=-0.608, -0.580, P<0.001), and work engagement was positively correlated with psychological capital (r=0.771, P<0.001). Compassion fatigue and psychological capital together accounted for 61.3% of the variation in work engagement, with the direct effects on work engagement were -0.206 (95%CI: -0.283--0.138, P<0.001) and 0.677 (95%CI: 0.599-0.744, P=0.001), respectively. Psychological capital partially mediated the relationship between compassion fatigue and work engagement, with a mediating effect of -0.397 (95%CI: -0.456--0.340, P<0.001), accounting for 65.8% of the total effect. Conclusion: The work engagement of clinical nurses is at a high level. Managers should take targeted measures to alleviate the symptoms of clinical nurses' compassion fatigue, improve their psychological capital, and then stabilize and improve their level of work engagement.目的： 探讨临床护士心理资本、共情疲劳与工作投入的关系，分析心理资本在共情疲劳与工作投入之间的中介效应，为减轻护士共情疲劳、提高工作投入水平提供科学依据。 方法： 于2021年12月至2022年2月，采用便利抽样的方法，选取四川省7家综合性医院的494名临床护士为研究对象，采用一般资料调查问卷、《共情疲劳简短量表》《工作投入简短量表》和《护士心理资本问卷》进行调查，采用Pearson相关分析共情疲劳、工作投入和心理资本间的相关性，采用逐步回归分析法和Bootstrap法分析共情疲劳和心理资本对工作投入的影响以及心理资本在共情疲劳和工作投入间的中介作用。 结果： 494名临床护士中，男33人（6.7%），女461人（93.3%），平均年龄（31.47±6.89）岁，平均工作年限（9.87±7.61）年，心理资本、共情疲劳和工作投入均分分别为（5.01±0.76）、（3.19±2.08）、（4.60±1.37）分；共情疲劳与心理资本和工作投入均呈负相关（r=-0.608、-0.580，P<0.001），工作投入与心理资本呈正相关（r=0.771，P<0.001）；共情疲劳与心理资本共同解释工作投入变异的61.3%，对工作投入的直接效应分别为-0.206（95%CI：-0.283~-0.138，P<0.001）和0.677（95%CI：0.599~0.744，P=0.001）。心理资本在共情疲劳和工作投入之间起部分中介作用，中介效应为-0.397（95%CI：-0.456~-0.340，P<0.001），占总效应65.8%。 结论： 临床护士工作投入处于较高水平，管理者可采取针对性措施缓解临床护士共情疲劳症状，提高其心理资本，进而稳定和提高其工作投入水平。.
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