1.Comparative analysis of magnetic resonance imaging for purulent meningitis in premature and full term infants
Yixian CHEN ; Yongyan SHI ; Jianhua FU ; Xindong XUE
Chinese Journal of Applied Clinical Pediatrics 2021;36(14):1068-1073
Objective:To compare the head magnetic resonance imaging (MRI) changes and the distribution of pathogens of purulent meningitis in premature and full term infants.Methods:This retrospective study assessed clinical data in 43 cases of neonatal purulent meningitis with positive blood or cerebrospinal fluid bacterial culture admitted to the Neonatal Ward of Shengjing Hospital of China Medical University from January 2012 to November 2019.According to the gestational age, those patients were divided into the premature infant group and the full term infant group.The general situation, head MRI and pathogen characteristics of both groups were compared.Results:The incidence of premature rupture of fetal membranes in the premature infant group was higher than that in the full term infant group [50.00%(13/26 cases) vs.5.88%(1/17 cases)], the rate of cesarean section in the premature infant group was higher than that in the term infant group [61.54%(16/26 cases) vs.23.53%(4/17 cases)], and there were significant difference between the 2 groups ( χ2=9.011 and 5.969, respectively, all P<0.05). There was no significant difference between 2 groups in age of onset [(9.8±7.0) d vs.(8.9±5.5) d], diagnosis[(13.0±7.1) d vs.(10.2±6.1) d] and examination [(16.1±7.9) d vs.(13.1±6.5) d] (all P>0.05). The top 3 pathogens were Klebsiella pneumonia ( K. pneumoniae) in 14 cases, Escherichia coli ( E. coli) in 11 cases and Streptococcus agalactiae (GBS) in 7 cases. K. pneumoniae was the most common pathogen in premature infants, and GBS was the most common pathogen in term infants.In the first MRI, white matter injury (WMI) was the most common disease (19 cases), the abnormal rate of MRI in the premature infant group was 65.38% (17/26 cases), the incidence of intracranial hemorrhage in the premature infant group was higher than that in the term infant group, the abnormal rate of MRI in the term infant group was 52.94% (9/17 cases), and the incidence of cerebral infarction in the term infant group was higher than that in the premature infant group.The MRI positive rates of meningitis caused by K. pneumoniae, E. coli and GBS were 57.14% (8/14 cases), 72.73% (8/11 cases) and 71.43% (5/7 cases), respectively.Infants with K. pneumoniae infections suffered from the main complications of WMI and intracranial hemorrhage.Infants infected with E. coli were prone to WMI in the early stage and hydrocephalus in the late stage.Infants with GBS were prone to WMI and cerebral infarction in the early stage and cerebromalacia in the late stage. Conclusions:There were some differences in the distribution of pathogenic bacteria and head MRI changes between premature infants and term infants, and head MRI of purulent meningitis caused by different pathogenic bacteria.A thorough understanding of the distribution of pathogens and the characteristics of head MRI in premature and full term infants contributed to the early diagnosis, treatment and prognosis of this disease.
2.Tailored core‒shell dual metal-organic frameworks as a versatile nanomotor for effective synergistic antitumor therapy.
Biyuan WU ; Jintao FU ; Yixian ZHOU ; Sulan LUO ; Yiting ZHAO ; Guilan QUAN ; Xin PAN ; Chuanbin WU
Acta Pharmaceutica Sinica B 2020;10(11):2198-2211
Malignant tumor has become an urgent threat to global public healthcare. Because of the heterogeneity of tumor, single therapy presents great limitations while synergistic therapy is arousing much attention, which shows desperate need of intelligent carrier for co-delivery. A core‒shell dual metal-organic frameworks (MOFs) system was delicately designed in this study, which not only possessed the unique properties of both materials, but also provided two individual specific functional zones for co-drug delivery. Photosensitizer indocyanine green (ICG) and chemotherapeutic agent doxorubicin (DOX) were stepwisely encapsulated into the nanopores of MIL-88 core and ZIF-8 shell to construct a synergistic photothermal/photodynamic/chemotherapy nanoplatform. Except for efficient drug delivery, the MIL-88 could be functioned as a nanomotor to convert the excessive hydrogen peroxide at tumor microenvironment into adequate oxygen for photodynamic therapy. The DOX release from MIL-88-ICG@ZIF-8-DOX nanoparticles was triggered at tumor acidic microenvironment and further accelerated by near-infrared (NIR) light irradiation. The
3.A homogenous nanoporous pulmonary drug delivery system based on metal-organic frameworks with fine aerosolization performance and good compatibility.
Yixian ZHOU ; Boyi NIU ; Biyuan WU ; Sulan LUO ; Jintao FU ; Yiting ZHAO ; Guilan QUAN ; Xin PAN ; Chuanbin WU
Acta Pharmaceutica Sinica B 2020;10(12):2404-2416
Pulmonary drug delivery has attracted increasing attention in biomedicine, and porous particles can effectively enhance the aerosolization performance and bioavailability of drugs. However, the existing methods for preparing porous particles using porogens have several drawbacks, such as the inhomogeneous and uncontrollable pores, drug leakage, and high risk of fragmentation. In this study, a series of cyclodextrin-based metal-organic framework (CD-MOF) particles containing homogenous nanopores were delicately engineered without porogens. Compared with commercial inhalation carrier, CD-MOF showed excellent aerosolization performance because of the homogenous nanoporous structure. The great biocompatibility of CD-MOF in pulmonary delivery was also confirmed by a series of experiments, including cytotoxicity assay, hemolysis ratio test, lung function evaluation,
4.NAMPT-targeting PROTAC promotes antitumor immunity via suppressing myeloid-derived suppressor cell expansion.
Ying WU ; Congying PU ; Yixian FU ; Guoqiang DONG ; Min HUANG ; Chunquan SHENG
Acta Pharmaceutica Sinica B 2022;12(6):2859-2868
Nicotinamide phosphoribosyl transferase (NAMPT) is considered as a promising target for cancer therapy given its critical engagement in cancer metabolism and inflammation. However, therapeutic benefit of NAMPT enzymatic inhibitors appears very limited, likely due to the failure to intervene non-enzymatic functions of NAMPT. Herein, we show that NAMPT dampens antitumor immunity by promoting the expansion of tumor infiltrating myeloid derived suppressive cells (MDSCs) via a mechanism independent of its enzymatic activity. Using proteolysis-targeting chimera (PROTAC) technology, PROTAC A7 is identified as a potent and selective degrader of NAMPT, which degrades intracellular NAMPT (iNAMPT) via the ubiquitin-proteasome system, and in turn decreases the secretion of extracellular NAMPT (eNAMPT), the major player of the non-enzymatic activity of NAMPT. In vivo, PROTAC A7 efficiently degrades NAMPT, inhibits tumor infiltrating MDSCs, and boosts antitumor efficacy. Of note, the anticancer activity of PROTAC A7 is superior to NAMPT enzymatic inhibitors that fail to achieve the same impact on MDSCs. Together, our findings uncover the new role of enzymatically-independent function of NAMPT in remodeling the immunosuppressive tumor microenvironment, and reports the first NAMPT PROTAC A7 that is able to block the pro-tumor function of both iNAMPT and eNAMPT, pointing out a new direction for the development of NAMPT-targeted therapies.