Epidemiological Characteristics, Antifungal Susceptibility, Risk Factors, and Outcomes of Candida Bloodstream Infection: A Ten-Year Surveillance in a Teaching Hospital in China.

Background: Candida is one of the most important pathogens of hospital-acquired bloodstream infections. Its morbidity and mortality are still high, which is a serious global public problem. Purpose: To investigate the strain distribution, drug susceptibility, clinical characteristics of patients, and risk factors affecting the prognosis of Candida bloodstream infection (BSI). Materials and Methods: We retrospectively collected the clinical data, infection-related indicators, prognosis, strain prevalence and drug susceptibility of 163 patients with Candida BSI in a teaching hospital from January 2012 to December 2022. Univariate and multivariate logistic regression were used to analyze the risk factors affecting the prognosis. Results: In 163 cases of Candida BSI, Candida albicans accounted for 48.47%, and Candida non-albicans accounted for 51.53%. A total of 163 patients with Candida BSI were mainly distributed in intensive care unit (ICU) and emergency department, accounting for 40.49% and 14.72%, respectively. The resistance rate of Candida albicans to fluconazole, itraconazole and voriconazole was less than 10%, and the sensitivity rate of Candida tropicalis to fluconazole, itraconazole and voriconazole was less than 80%. The mortality rate of 163 patients with Candida BSI was 33.13%, with Candida non-albicans higher than that of Candida albicans (p = 0.04). Multivariate analysis showed that hemodialysis (OR = 0.199, 95% CI: 0.059-0.673, P = 0.009), arteriovenous catheters (OR = 0.344, 95% CI: 0.130-0.913, P = 0.032), elevated neutrophil count (OR = 0.409, 95% CI: 0.194-0.862, P = 0.019) and APACHE II score (OR = 0.848, 95% CI: 0.789~0.911, P < 0.001) were independent risk factors for death in patients with candidemia. Conclusion: The blood flow infection rate of Candida non-albicans is increasing, and the mortality rate and resistance to antifungal drugs are higher than that of Candida albicans. Hemodialysis, arteriovenous catheters, elevated neutrophil count and APACHE II score were associated with death in patients with Candida BSI.

Global diversity of policy, coverage, and demand of COVID-19 vaccines: a descriptive study.

BACKGROUND: Hundreds of millions of doses of coronavirus disease 2019 (COVID-19) vaccines have been administered globally, but progress on vaccination varies considerably between countries. We aimed to provide an overall picture of COVID-19 vaccination campaigns, including policy, coverage, and demand of COVID-19 vaccines. METHODS: We conducted a descriptive study of vaccination policy and doses administered data obtained from multiple public sources as of 8 February 2022. We used these data to develop coverage indicators and explore associations of vaccine coverage with socioeconomic and healthcare-related factors. We estimated vaccine demand as numbers of doses required to complete vaccination of countries' target populations according to their national immunization program policies. RESULTS: Messenger RNA and adenovirus vectored vaccines were the most commonly used COVID-19 vaccines in high-income countries, while adenovirus vectored vaccines were the most widely used vaccines worldwide (180 countries). One hundred ninety-two countries have authorized vaccines for the general public, with 40.1% (77/192) targeting individuals over 12 years and 32.3% (62/192) targeting those ≥ 5 years. Forty-eight and 151 countries have started additional-dose and booster-dose vaccination programs, respectively. Globally, there have been 162.1 doses administered per 100 individuals in target populations, with marked inter-region and inter-country heterogeneity. Completed vaccination series coverage ranged from 0.1% to more than 95.0% of country target populations, and numbers of doses administered per 100 individuals in target populations ranged from 0.2 to 308.6. Doses administered per 100 individuals in whole populations correlated with healthcare access and quality index (R2 = 0.59), socio-demographic index (R2 = 0.52), and gross domestic product per capita (R2 = 0.61). At least 6.4 billion doses will be required to complete interim vaccination programs-3.3 billion for primary immunization and 3.1 billion for additional/booster programs. Globally, 0.53 and 0.74 doses per individual in target populations are needed for primary immunization and additional/booster dose programs, respectively. CONCLUSIONS: There is wide country-level disparity and inequity in COVID-19 vaccines rollout, suggesting large gaps in immunity, especially in low-income countries.

Anaphylactic Rare Saponins Separated from Panax notoginseng Saponin and a Proteomic Approach to Their Anaphylactic Mechanism.

In recent years, many traditional Chinese medicine injections based on Panax notoginseng saponin (PNS) have been reported to cause anaphylaxis. Previous studies on the anaphylactic saponins of PNS and their mechanism are inadequate. In this study, potential anaphylactic saponins were obtained by the separation of PNS and preparation of each individual component through comprehensive techniques, such as liquid chromatography, preparative chromatography, HPLC, NMR, and MS. The anaphylactic abilities of these saponins were tested using RBL-2H3 cells via a ß-hexosaminidase release rate test. The results for the mechanism of anaphylaxis were obtained by a proteomic analysis using RBL-2H3 cells. The results indicate that, among all the saponins prepared, gypenoside LXXV and notoginsenoside T5 showed strong anaphylactic abilities and notoginsenoside ST-4 and ginsenoside Rk3 showed weak anaphylactic abilities. These 4 saponins can induce anaphylaxis via direct stimulation of effector cells. The gene oncology enrichment analysis results showed that, among these saponins, only gypenoside LXXV was related to organelles of the endoplasmic reticulum and Golgi apparatus and biological processes in response to organic cyclic compounds. Four proteins in RBL-2H3 cells with the accession numbers A0A0G2JWQ0, D3ZL85, D4A5G8, and Q8K3F0 were identified as crucial proteins in the anaphylactic process. This research will help traditional Chinese medicine injection manufacturers strengthen their quality control and ensure the safety of anaphylactic saponins.

Repeated Aconitine Treatment Induced the Remodeling of Mitochondrial Function via AMPK-OPA1-ATP5A1 Pathway.

Aconitine is attracting increasing attention for its unique positive inotropic effect on the cardiovascular system, but underlying molecular mechanisms are still not fully understood. The cardiotonic effect always requires abundant energy supplement, which is mainly related to mitochondrial function. And OPA1 has been documented to play a critical role in mitochondrial morphology and energy metabolism in cardiomyocytes. Hence, this study was designed to investigate the potential role of OPA1-mediated regulation of energy metabolism in the positive inotropic effect caused by repeated aconitine treatment and the possible mechanism involved. Our results showed that repeated treatment with low-doses (0-10 µM) of aconitine for 7 days did not induce detectable cytotoxicity and enhanced myocardial contraction in Neonatal Rat Ventricular Myocytes (NRVMs). Also, we first identified that no more than 5 µM of aconitine triggered an obvious perturbation of mitochondrial homeostasis in cardiomyocytes by accelerating mitochondrial fusion, biogenesis, and Parkin-mediated mitophagy, followed by the increase in mitochondrial function and the cellular ATP content, both of which were identified to be related to the upregulation of ATP synthase α-subunit (ATP5A1). Besides, with compound C (CC), an inhibitor of AMPK, could reverse aconitine-increased the content of phosphor-AMPK, OPA1, and ATP5A1, and the following mitochondrial function. In conclusion, this study first demonstrated that repeated aconitine treatment could cause the remodeling of mitochondrial function via the AMPK-OPA1-ATP5A1 pathway and provide a possible explanation for the energy metabolism associated with cardiotonic effect induced by medicinal plants containing aconitine.

Hepatotoxicity and nephrotoxicity assessment on ethanol extract of Fructus Psoraleae in Sprague Dawley rats using a UPLC-Q-TOF-MS analysis of serum metabolomics.

Fructus Psoraleae (FP) is commonly used in the treatment of vitiligo, osteoporosis, and other diseases in clinic. As a result, the toxicity caused by FP is frequently encountered in clinical practice; however, the underlying toxicity mechanism remains unclear. The purpose of this study was to investigate the toxic effect of the ethanol extract of FP (EEFP) in rats and to explore the underlying toxic mechanisms using a metabolomics approach. The toxicity was evaluated by hematological indicators, biochemical indicators, and histological changes. In addition, a serum metabolomic method based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight MS (UPLC-Q-TOF-MS) had been established to investigate the hepatorenal toxicity of FP. Multivariate statistical approaches, such as partial least squares discriminant analysis and orthogonal partial least squares discriminant analysis, were built to evaluate the toxic effects of FP and find potential biomarkers and metabolic pathways. Ten endogenous metabolites had been identified and the related metabolic pathways were involved in phospholipid metabolism, amino acid metabolism, purine metabolism, and antioxidant system activities. The results showed that long-term exposure to high-dose EEFP may cause hepatorenal toxicity in rats. Therefore, serum metabolomics can improve the diagnostic efficiency of FP toxicity and make it more accurate and comprehensive.

A comparative study of aurantio-obtusin metabolism in normal and liver-injured rats by ultra performance liquid chromatography quadrupole time-of-flight mass spectrometry.

Aurantio-obtusin, an anthraquinone isolated from cassiae semen, possesses diverse pharmacological activities, including hypotensive, hypolipidemic and anti-inflammatory effects. However, our previous studies demonstrated that exposure to aurantio-obtusin induced hepatotoxicity, but the mechanisms of the toxic effects remain unknown. The purpose of the present study is to establish a strategy for the metabolite profiling of aurantio-obtusin in normal and liver-injured rats. This study aimed at identifying the in vivo metabolites and the metabolic profiling in rats after oral administration at a dose of aurantio-obtusin (4 and 200 mg/kg) by using an ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) and metabolynx™ software. A total of 39 metabolites were detected and 3 of them were compared with standard substances. The results indicated that the principal metabolism pathways of aurantio-obtusin in normal rats were glucuronidation and sulfation, while in rats with liver injury, demethylation, dehydroxylation and reduction were also observed and regarded as new metabolic patterns of aurantio-obtusin. These findings helped us to understand the pharmacological and toxicological mechanisms of aurantio-obtusin. Moreover, this study could help to elucidate the metabolic profiling of other anthraquinones.

Bavachin Induces Apoptosis through Mitochondrial Regulated ER Stress Pathway in HepG2 Cells.

As a traditional herbal medicine, the fruits of Psoralea corylifolia L. (Fructus Psoraleae (FP)) have been widely used for the treatment of various skin diseases for hundred years. Recently, the emerging FP-induced toxic effects, especially hepatotoxicity, in clinic are getting the public's attention. However, its exact toxic components and mechanisms underlying remain unclear. Bavachin, one of flavonoids in FP, has been documented as a hepatotoxic substance, and the present study aimed to determine the toxicity caused by bavachin and the possible toxic mechanisms involved using human hepatocellular carcinoma (HepG2) cells. Our results showed that bavachin could significantly inhibited cell proliferation and trigger the endoplasmic reticulum (ER) stress in a dose dependent manner. Downregulating ER stress using tauroursodeoxycholic acid (TUDCA) obvious attenuated bavachin-triggerd cell apoptosis. Then, small interfering RNA (siRNA) knock-down of Mitofusion2 (Mfn2) resulted in a remarkable aggravation of ER stress through the inhibition of the phosphorylation of protein kinase B (Akt). Additionally, suppression of reactive oxygen species (ROS) by ROS Scavenger (N-acetyl-l-cystein (NAC)) also reduced bavachin-induced ER stress. Taken together, our study demonstrated that bavachin-induced ER stress caused cell apoptosis by Mfn2-Akt pathway, and that ROS may participate upstream in this mechanism. Here, we not only provide a new understanding of ROS/Mfn2/Akt pathway in bavachin-induced cytotoxicity via the ER stress, but also identify a new specific intervention to prevent FP-induced hepatotoxicity in the future.

Facile synthesis of magnetic metal organic frameworks for highly efficient proteolytic digestion used in mass spectrometry-based proteomics.

Mass spectrometry (MS) based bottom-up strategy is now the first choice for proteomics analysis. In this process, highly efficient and complete enzymatic degradation of protein samples is extremely important to achieve in-depth protein coverage and high-throughput protein profiling. However, conventional in-solution digestion suffer from long digestion time and enzyme autolysis that limit the protein sample processing throughput and identification accuracy. Here, we developed a novel type of magnetic metal organic frameworks (MOFs)-based immobilized enzyme reactor, Fe3O4@DOTA-ZIF-90-trypsin. By introducing a stable chelator, 1,4,7,10-tetraazacyclododecane N,N',N″,N‴-tetraacetic acid (DOTA), onto the magnetic cores, the hybrid supporting matrix of the immobilized enzyme reactor Fe3O4@DOTA-ZIF-90 has novel characteristics that include: i) favourable magnetic response (1.01 emu g-1) that makes the operation easy and convenient, ii) ultrahigh surface area (565.21 m2 g-11) and active sites that ensure high loading amounts and covalent linkage of enzyme, and iii) excellent structural and thermal stability that endows the immobilized enzyme reactor a prolonged lifespan. The performance of the magnetic MOFs-immobilized trypsin is first investigated using the standard protein, BSA, and the results showed that the immobilized enzyme reactor exhibits satisfactory digestion efficiency within only 1 min with the sequence coverage (80%) that is comparable or even better than that (70%) of the traditional 12 h-free trypsin digestion. To test the applicability of the magnetic MOFs-based immobilized enzyme reactor, protein samples extracted from 400 oocytes in mice were digested through the new immobilized enzyme reactor. In total, 8957 peptides corresponding to 1843 protein groups are identified, which are nearly of 40% and 67% increases in the number of identified proteins and peptides compared to using in-solution digestion with free proteases. Specifically, the identification of oocyte-specific proteins was critical in the discovery of and understanding the regulation mechanism of oocyte maturation. Thus, this synthetic procedure of Fe3O4@DOTA-ZIF-90 provides a universal method for fabrication of magnetic MOFs materials, and the successful application of Fe3O4@DOTA-ZIF-90-trypsin in efficient protein digestion for deeper proteome coverage will undoubtedly enlarge the uses for MOFs.

Influences of Realgar-Indigo naturalis, A Traditional Chinese Medicine Formula, on the Main CYP450 Activities in Rats Using a Cocktail Method.

The purpose of this work was to study the influences of Realgar-Indigo naturalis (RIF) and its principal element realgar on 4 main cytochrome P450 enzymes activities in rats. A simple and efficient cocktail method was developed to detect the four probe drugs simultaneously. In this study, Wistar rats were administered intragastric RIF and realgar for 14 days; mixed probe drugs were injected into rats by caudal vein. Through analyzing the pharmacokinetic parameter of mixed probe drugs in rats, we can calculate the CYPs activities. The results showed that RIF could inhibit CYP1A2 enzyme activity and induce CYP2C11 enzyme activity significantly. Interestingly, in realgar high dosage group, CYP3A1/2 enzyme activity was inhibited significantly, and different dosage of realgar manifested a good dose-dependent manner. The RIF results indicated that drug coadministrated with RIF may need to be paid attention in relation to drug-drug interactions (DDIs). Realgar, a toxic traditional Chinese medicine (TCM), does have curative effect on acute promyelocytic leukemia (APL). Its toxicity studies should be focused on. We found that, in realgar high dosage group, CYP3A1/2 enzymes activity was inhibited. This phenomenon may explain its potential toxicity mechanism.

A novel microscale preparative gel electrophoresis system.

Currently, the separation targets of preparative electrophoresis range from milligrams to micrograms of proteins. However, most commercially available preparative electrophoretic instruments function at the milligram level. Although some preparative electrophoretic apparatuses operated at the microgram level, the fractionation results are often unsatisfying because they suffer from low resolution, poor recovery, or a long fractionation time. To address these issues, we developed a novel microscale preparative electrophoresis system that consists of a separation apparatus and an elution apparatus. Protein samples are first loaded onto the separation apparatus and separated over the gel according to the molecular weight of each protein. Then the separation gel is transferred to the elution apparatus and the proteins on the gel are eluted through the thickness of the gel. This system offers the following advantages: (1) high resolution: almost no overlap between the adjacent fractions; (2) a short recovery time: fractionation was performed in 2 hours including separation in 100 min and elution in 20 min and (3) high recovery: recovery was as high as 91.8%.

[A simple preparation method of an electric heating apparatus for heating capillary chromatographic columns and its application in liquid chromatography-mass spectrometry system].

For deep coverage of proteome, especially in performing qualitative identification and quantitative analysis of low-abundance proteins, the most commonly used method is the application of a longer capillary chromatographic column or a capillary column packed with smaller particle sizes. However, this causes another problem, the very high back pressure which results in liquid leaks in some connection parts in a liquid chromatograph. To solve this problem, an electric heating apparatus was developed to raise the temperature of a capillary column for reducing its back pressure, which was further applied in a capillary high performance liquid chromatography-tandem mass spectrometry system (cHPLC-MS/MS), and evaluated in the terms of chromatographic column back pressure and chromatographic column efficiency using bovine serum albumin (BSA) tryptic digests and yeast tryptic digests, separately. The results showed that at the optimum current, our electric heating apparatus could reduce the column pressure of a capillary column packed with 3 µm packing materials by at least 50% during the separation of BSA tryptic digestion and yeast tryptic digestion, compared with that without electric heating. The column efficiency was also increased slightly. This suggested that the electric heating apparatus can significantly reduce the column pressure, which provides an efficient way to use capillary chromatographic columns packed with smaller sizes of particles at a lower pressure.

A new sample preparation method for the absolute quantitation of a target proteome using (18)O labeling combined with multiple reaction monitoring mass spectrometry.

A key step in the workflow of bottom-up proteomics is the proteolysis of proteins into peptides with trypsin. In addition, enzyme-catalytic (18)O labeled peptides as internal standards coupled with multiple reaction monitoring mass spectrometry (MRM MS) for the absolute quantitation of the target proteome is commonly used for its convenient operation and low cost. However, long digestion and labeling times, incomplete digestion and (18)O to (16)O back exchange limit its application, therefore, we developed a rapid and efficient digestion method based on a high ratio of trypsin to protein. In addition, after separation of the digested samples using pipette tips packed with reversed-phase packing materials in house, the trypsin can be separated, collected and reused at least four times. Based on this approach, a novel protein quantification method using (18)O-labeled QconCAT peptides as internal standards combined with MRM MS for the absolute quantitation of a target proteome is established. Experimental results showed that the novel method had high digestion and (18)O labeling efficiencies, and no (18)O to (16)O back-exchange occurred. A linear range covering 2 orders of magnitude and a limit of quantification (LOQ) as low as 5 fmol were achieved with an RSD below 10%. Then, the quantitative method is used for the absolute quantitation of drug metabolizing enzymes in human liver microsomes. The results are in good agreement with the previously reported data, which demonstrates that the novel method can be used for absolute quantitative analyses of target proteomes in complex biological samples.

[A novel multiple-channel apparatus for packing capillary chromatographic column and its application].

A novel multiple-channel apparatus for packing capillary chromatographic column was designed and manufactured for packing six capillary chromatographic columns with close column efficiency at the same time. Briefly, it consists of a magnetic stirrer, a liquid chromatographic pump and a multiple-channel can. The reagents used for preparing ODS (C18) slurry and stirring condition of the magnetic stirrer were optimized in the study. Two batches of capillary chromatographic columns were packed under the optimum condition, and these packed capillary chromatographic columns were evaluated in the terms of peak capacity, sequence coverage, retention times of three peptide ions and column pressure using the tryptic digest of a bovine serum albumin (BSA) and detected by LC-MS in electrospray ionization (ESI) mode. The experimental results showed that the six capillary chromatographic columns packed at the same time had close column efficiencies, however, the column efficiencies of twelve capillary chromatographic columns packed at two times were significantly different. In addition, there was no significant column efficiency difference when packing one or six capillary chromatographic columns at the same time. The multiple-channel apparatus designed by us is simple, time-saving, and can be applied to pack capillary chromatographic columns with similar column efficiencies, thus it is of evident advantage over traditional one-channel apparatus.

[Recent advances in preparative electromigration techniques for proteins].

Preparative electromigration techniques are a category of separation and preparation techniques based on differential electromigration principle. These techniques are widely applied in biomacromolecule and proteome researches. Related techniques mainly include preparative electrophoresis, preparative electrochromatography, preparative isoelectric focusing and free flow electrophoresis and so on. We review each kind of the preparative electromigration techniques on its apparatus designs, applications, advantages and disadvantages in detail. Microscale preparative electrophoresis is a hot spot in recent years. Its high resolution, high recovery and high efficiency make it a more prominent role in the biological sample analysis. In this review, we focus on some advances in microscale preparative electrophoresis and also give an outlook on preparative electromigration techniques in the future.

[Metal-tag labeling coupled with high performance liquid chromatography-selected ion monitoring mass spectrometry for absolute quantitation of proteins].

A novel method has been established based on metal element chelated tags coupled with high performance liquid chromatography-selected ion monitoring mass spectrometry (HPLC-SIM/MS). The labeling efficiency and stability of metal element chelated tags, the chromatographic retention behavior and MS behavior of the labeled peptides, the linear range and accuracy of this method were examined. The results showed that the metal element chelated tag method has high labeling efficiency and high labeling stability, and the labeled peptides with different kinds of metal tags have consistent chromatographic retention behavior. The method of metal tags coupled with HPLC-SIM/MS has high sensitivity with the limit of quantification (LOQ) up to 1 fmol. The linear range for the method was between 1 fmol to 500 fmol with R2 > 0.99, which means the method has a good linearity. Moreover, this method had an average recovery of 117.01%. The method was used in the absolute quantitation of a protein enolase in Thermoanaerobacter tengcongensis (TTE) with a relative standard deviation of 5.74%, which means high precision. All the results showed that this method is accurate and reliable for the absolute quantitation of proteins. This gives us an alternative for the quantitative determination of proteins in relatively simple biological samples.

[Progress in metal-organic frameworks].

Metal-organic frameworks (MOFs) are a class of crystalline materials built from organic binding ligands and metal ions through self-assembly. Currently, MOFs have drawn a growing interest among the scientific teams of various fields. Compared with conventional inorganic porous materials, MOFs possess larger specific surface areas, higher porosity and diversity of structures and functions, thus many potential applications have been proposed in the domains of gas adsorption and separation, sensors, drug delivery, catalysis or others. The combinations of MOFs and other materials such as graphene oxide, magnetic nanoparticles have obvious advantages in adsorption and separation. The appearance of novel materials greatly promotes interdisciplinary developments such as organic chemistry, inorganic chemistry, coordination chemistry, materials chemistry, life science and computer science. This article reviews the progress of MOFs in recent years, including the characteristics of MOFs, advances at home and abroad, applications, central issues of compound MOFs and the prospects in the future.

Preparation of mixed lanthanides-immobilized magnetic nanoparticles for selective enrichment and identification of phosphopeptides by MS.

A new type of mixed lanthanides-immobilized (Tb(3+) , Tm(3+) , Ho(3+) , Lu(3+) ) magnetic nanoparticles, Fe3 O4 @TCPP-DOTA-M(3+) , was prepared with a particle size of approximately 30 nm. A model protein, α-casein, and a protein mixture of α-casein and BSA (1:100) were first used to test the phosphopeptide enrichment efficiency of the newly developed magnetic nanoparticles. For the model protein α-casein, 19 phosphopeptides were identified with the newly developed materials. Even in the tryptic digest of α-casein and BSA (1:100), 16 phosphopeptides were easily detected, suggesting that the novel materials possess high selectivity in phosphopeptide enrichment. To evaluate the phosphopeptide enrichment efficiency in a real biological sample, the materials were used to capture phosphopeptides in the tryptic digests of an extract of HeLa cells. In total, 9048 phosphopeptides corresponding to 2103 phosphoproteins were identified in a single mass spectrometric analysis, indicating the great potential of the new materials for practical applications. Compared with metal oxide-based enrichment methods, the newly developed materials are convenient to prepare and easy to handle, and they save time in the phosphopeptide enrichment procedure, making these materials a good choice for highly selective and sensitive phosphopeptide enrichment in future phosphoproteome analyses.