Proanthocyanidin B_2(PAC-B_2), a polyphenolic dimeric compound comprising two epicatechin molecules linked by a C-C bond, is extensively found in traditional Chinese medicines, with anti-tumor and anti-oxidant activities. Given the limited bioavailability, a thorough investigation and comprehensive understanding of PAC-B_2 metabolism in vivo are essential for elucidating therapeutic forms and mechanisms. In the present study, ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS) in the negative ion mode was employed to acquire the MS/MS information of PAC-B_2 and metabolites in urine and feces samples of the rats administrated with PAC-B_2. Online energy-resolved MS(ER-MS) was applied as supplementary to obtain the full collision energy ramp-MS~2 spectra(FCER-MS~2) of isomers-of-interest, which implied comprehensive MS~2 information of targeted compounds. Finally, the possible metabolic pathways of PAC-B_2 in rats were proposed. The primary fragmentation behaviors of PAC-B_2 in the negative ion mode included quinone methide fission between C_4-C_8 bond, retro Diels-Alder cracking of F-ring, heterocyclic ring fission of C-ring, and neutral loss of small molecules such as H_2O. A total of 25 metabolites were tentatively elucidated in urine and feces samples of rats administrated with PAC-B_2 by fragmentation pattern and reported literature. Two groups of isomers, M3/M4/M5 and M9/M11, were confirmatively differentiated based on the relationships between optimal collision energy provided by FCER-MS~2 and bond properties, including bond length and bond dissociation energy. In addition to the ring-opening and methylation, PAC-B_2 could also be metabolized into epicatechin and low molecular weight phenolic acids, which were subsequently subjected to dehydroxylation, ring-opening, methylation, sulfation, and glucuronidation. The structural information provided by online ER-MS and FCER-MS~2 enabled the differentiation of isomers and improved the identification confidence. More importantly, the present study deeply analyzes the in vivo metabolic pathways of PAC-B_2, providing a basis for the research on the pharmacological mechanism of this compound.
Animals ; Proanthocyanidins/urine* ; Rats ; Male ; Drugs, Chinese Herbal/chemistry* ; Rats, Sprague-Dawley ; Tandem Mass Spectrometry ; Chromatography, High Pressure Liquid ; Feces/chemistry* ; Molecular Structure

Poor water solubility is the primary obstacle preventing the development of many pharmacologically active compounds into oral preparations. Self-nanoemulsifying drug delivery systems(SNEDDS) have become a widely used strategy to enhance the oral bioavailability of poorly soluble drugs by inducing a supersaturated state, thereby improving their apparent solubility and dissolution rate. However, the supersaturated solutions formed in SNEDDS are thermodynamically unstable systems with solubility levels exceeding the crystalline equilibrium solubility, making them prone to drug precipitation in the gastrointestinal tract and ultimately hindering drug absorption. Therefore, maintaining a stable supersaturated state is crucial for the effective delivery of poorly soluble drugs. Incorporating polymers as precipitation inhibitors(PPIs) into the formulation of supersaturated self-nanoemulsifying drug delivery systems(S-SNEDDS) can inhibit drug aggregation and crystallization, thus maintaining a stable supersaturated state. This has emerged as a novel preparation strategy and a key focus in SNEDDS research. This review explores the preparation design of SNEDDS and the technical challenges involved, with a particular focus on polymer-based S-SNEDDS for enhancing the solubility and oral bioavailability of poorly soluble drugs. It further elucidates the mechanisms by which polymers participate in transmembrane transport, summarizes the principles by which polymers sustain a supersaturated state, and discusses strategies for enhancing drug absorption. Altogether, this review provides a structured framework for the development of S-SNEDDS preparations with stable quality and reduced development risk, and offers a theoretical reference for the application of S-SNEDDS technology in improving the oral bioavailability of poorly soluble drugs.
Solubility ; Administration, Oral ; Polymers/chemistry* ; Drug Delivery Systems/methods* ; Humans ; Emulsions/chemistry* ; Biological Availability ; Animals ; Pharmaceutical Preparations/administration & dosage*

Iodine speciations in aquatic environments are affected by dissolved oxygen,redox potential,microbial activity,organic matter decomposition,light reaction,etc.Accurate quantification of iodine speciation can not only help to understand the geochemical cycle of iodine,but also help to trace and study environmental processes.Based on the combination of ion chromatography(IC)and inductively coupled plasma mass spectrometry(ICP-MS),a rapid and sensitive method was established for determining the speciations of iodine in environmental water samples including seawater,river water,lake water,rainwater,groundwater,etc.The results presented here showed that IO3?and I?in seawater were quickly separated and measured within 120 s when using guard column AG22 and 8 mmol/L(NH4)2CO3 as the mobile phase.While for lake water,river water and precipitation samples with high soluble organically bond iodine(SOI),an AS22 separation column(250 mm×4 mm)connected with a guard column and using 50 mmol/L(NH4)2CO3 as mobile phase could effectively separate unknown SOI from IO3? to achieve accurate quantification of IO3?.For accurate correction of iodine measurement signal fluctuations,133Cs was directly added to the(NH4)2CO3 mobile phase as an internal standard.The SOI content was calculated by the total iodine concentrations minus the sum of IO3?and I?.The precision of the established iodine speciation analytical method was better than 3.5%,and the standard addition experiment showed that the analytical method was accurate.When the injection volume was 25 μL,the detection limits were 0.011?0.025 μg/L for IO3? and 0.023?0.031 μg/L for I?,respectively.The method was successfully used to analyze IO3?,SOI and I? in environmental water samples,such as seawater,river water,rainwater and groundwater.

The pregnant woman was 30 years old,G2P0.This singleton pregnancy at 22 weeks of gestation was screened for second-trimester ultrasound malformations,suggesting fetal aortic valve atresia,aortic stenosis with reverse blood flow,mitral valve atresia,and markedly enlarged left ventricle,which was considered for the diagnosis of hypoplastic left heart syndrome(HLHS).The pregnancy was terminated at our hospital and subsequently underwent genetic testing with results of heterozygous variants in the NOTCH1 gene,which can cause aortic valve disease type 1.The findings of the fetal autopsy were aortic valve atresia,mitral valve widening and thickening,and left ventricular enlargement with myocardial infarction.This report focuses on the ultrasound characteristics of HLHS with left ventricular enlargement and its hemodynamic changes in order to improve clinicians'understanding of the progressive changes in the disease phenotype of HLHS.

Fucoidan(FUC)is a natural seaweed-derived drug.Previously,our experiments have shown that FUC can significantly inhibit the cell viability of human osteosarcoma 143B cells and induce cell death,but the mechanism remains unclear.Ferroptosis,a novel form of cell death,has emerged as an important target for tumor therapy.This study aims to investigate whether FUC induces ferroptosis of 143B cells and elucidate its underlying molecular mechanisms.CCK-8 and LDH assays result showed that FUC(10,100,400 μg/mL)significantly reduced cell viability of 143B cells and induced cell death.Calce-in-AM staining,FeRhoNox-1 staining,and C11 BODIPY 581/591 staining indicated that FUC obviously increased the levels of labile iron pool(LIP),Fe2+,and lipid reactive oxygen species(Lip ROS)in 143B cells.Chemical colorimetric analysis revealed that FUC markedly decreased intracellular Glutathi-one(GSH)contents.Real-time quantitative PCR showed that FUC dramatically reduced the mRNA lev-els of ferroptosis-related factors solute carrier family 7 member 11(SLC7A11)and glutathione peroxidase 4(GPX4),while increasing the mRNA levels of prostaglandin endoperoxide synthase 2(PTGS2)and acyl-CoA synthetase long-chain family member 4(ACSL4).Western blotting analysis demonstrated that FUC significantly reduced the protein levels of SLC7A11 and GPX4,and the ratios of p-PI3K/PI3K,p-AktSer473/Akt,and p-AktThr308/Akt,but increased the protein level of ACSL4.Immunofluorescence staining showed that FUC obviously inhibited the nuclear translocation of p-AktSer473.The ferroptosis in-hibitor ferrostatin-1(Fer-1)and iron chelator deferoxamine(DFO)remarkably suppressed cell death in-duced by FUC in 143B cells.Additionally,the PI3K/Akt pathway activator 740Y-P significantly inhibi-ted FUC-induced iron overload and lipid peroxidation in 143B cells,and restored the protein levels of SLC7A11 and GPX4.In conclusion,FUC can induce ferroptosis of 143B cells by inhibiting the PI3K/Akt signaling pathway,which may be a potential target for the prevention and treatment of osteosarcoma.

Fucoidan(FUC)is a natural seaweed-derived drug.Previously,our experiments have shown that FUC can significantly inhibit the cell viability of human osteosarcoma 143B cells and induce cell death,but the mechanism remains unclear.Ferroptosis,a novel form of cell death,has emerged as an important target for tumor therapy.This study aims to investigate whether FUC induces ferroptosis of 143B cells and elucidate its underlying molecular mechanisms.CCK-8 and LDH assays result showed that FUC(10,100,400 μg/mL)significantly reduced cell viability of 143B cells and induced cell death.Calce-in-AM staining,FeRhoNox-1 staining,and C11 BODIPY 581/591 staining indicated that FUC obviously increased the levels of labile iron pool(LIP),Fe2+,and lipid reactive oxygen species(Lip ROS)in 143B cells.Chemical colorimetric analysis revealed that FUC markedly decreased intracellular Glutathi-one(GSH)contents.Real-time quantitative PCR showed that FUC dramatically reduced the mRNA lev-els of ferroptosis-related factors solute carrier family 7 member 11(SLC7A11)and glutathione peroxidase 4(GPX4),while increasing the mRNA levels of prostaglandin endoperoxide synthase 2(PTGS2)and acyl-CoA synthetase long-chain family member 4(ACSL4).Western blotting analysis demonstrated that FUC significantly reduced the protein levels of SLC7A11 and GPX4,and the ratios of p-PI3K/PI3K,p-AktSer473/Akt,and p-AktThr308/Akt,but increased the protein level of ACSL4.Immunofluorescence staining showed that FUC obviously inhibited the nuclear translocation of p-AktSer473.The ferroptosis in-hibitor ferrostatin-1(Fer-1)and iron chelator deferoxamine(DFO)remarkably suppressed cell death in-duced by FUC in 143B cells.Additionally,the PI3K/Akt pathway activator 740Y-P significantly inhibi-ted FUC-induced iron overload and lipid peroxidation in 143B cells,and restored the protein levels of SLC7A11 and GPX4.In conclusion,FUC can induce ferroptosis of 143B cells by inhibiting the PI3K/Akt signaling pathway,which may be a potential target for the prevention and treatment of osteosarcoma.

The pregnant woman was 30 years old,G2P0.This singleton pregnancy at 22 weeks of gestation was screened for second-trimester ultrasound malformations,suggesting fetal aortic valve atresia,aortic stenosis with reverse blood flow,mitral valve atresia,and markedly enlarged left ventricle,which was considered for the diagnosis of hypoplastic left heart syndrome(HLHS).The pregnancy was terminated at our hospital and subsequently underwent genetic testing with results of heterozygous variants in the NOTCH1 gene,which can cause aortic valve disease type 1.The findings of the fetal autopsy were aortic valve atresia,mitral valve widening and thickening,and left ventricular enlargement with myocardial infarction.This report focuses on the ultrasound characteristics of HLHS with left ventricular enlargement and its hemodynamic changes in order to improve clinicians'understanding of the progressive changes in the disease phenotype of HLHS.

Objective To develop a portable medical oxygen purity analyzer capable of real-time detection of multi-compo-nent gases in medical oxygen or aviation oxygen to ensure the safety of oxygen consumption.Methods The portable medical oxygen purity analyzer with STM3F103RC as the main controller involved in a management module,an oxygen detection module,a carbon monoxide/chlorine detection module,a flow/carbon dioxide detection module and a dew point detection module as its hardware components,which had its human-machine interface programmed with DGUS supervision,control and data acquisition(SCADA)software and system program developed with C language under Keil MDK environment.The performance verification of the analyzer developed was carried out in terms of oxygen detection error and stability and errors for measuring carbon monoxide,chlorine and carbon dioxide.Results The analyzer showed high precision when used to detect oxygen with high volume fraction,with long-term stability and the absolute error restrained within±0.1％;the erros for measuring carbon monoxide,chlorine and carbon dioxide were all limited within±5％FS to meet the desired requirements.Condusion The portable medical oxygen purity analyzer developed with high precision,stability and portability can be used for detection of medical oxygen and aviation oxygen.[Chinese Medical Equipment Journal,2024,45(3):36-40]

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]