In vivo pharmacodynamic study of contezolid acefosamil, a prodrug of contezolid for oral and intravenous administration.

OBJECTIVES: Contezolid acefosamil is a novel O-acyl phosphoramidate prodrug of contezolid. In the current study, we aimed to systemically evaluate the efficacy of contezolid acefosamil against infections caused by multiple Gram-positive pathogens, and compare the efficacy of the prodrug by oral and intravenous administrations. METHODS: The in vivo pharmacodynamic efficacy of contezolid acefosamil was evaluated in mouse models of systemic (with five S. aureus, three S. pneumoniae and two S. pyogenes bacterial isolates) and thigh (with two S. aureus isolates) infections using linezolid as the reference agent. RESULTS: In both models, contezolid acefosamil administrated either orally or intravenously, demonstrated high antibacterial efficacy similar to linezolid, and the antibacterial efficacy of oral and intravenous contezolid acefosamil were comparable. CONCLUSIONS: The high aqueous solubility and great efficacy of contezolid acefosamil support its clinical development as an injectable and oral antibiotic suitable for serious Gram-positive infections.

Clinical and microbiological characteristics of hypervirulent Klebsiella pneumoniae (hvKp) in a hospital from North China.

INTRODUCTION: The clinical and molecular characteristics of hypervirulent Klebsiella pneumoniae (hvKp) in various provinces of China have been reported, however, there have been few reports in Hebei Province, North China. METHODOLOGY: The hvKp was identified by PCR amplification of hypervirulence-related genes, the hypermucoviscous phenotype was determined by the "string test", the drug susceptibility analysis was performed using the VITEK® 2 Compact Bacterial Identification and Monitoring System. Logistic regression was used to identify risk factors for hvKp infection. The molecular epidemiological characteristics of the strains were analyzed by pulsed-field gel electrophoresis (PFGE), and the capsular serotype of hvKp strain was detected by PCR. RESULTS: Overall, 52.21% (59/113) of K. pneumoniae isolates were hvKp, and the ratios of patients with older ages or a higher PMN cell count among hvKp infection were higher than those among classical Klebsiella pneumoniae (cKp) infection. hvKp are more susceptible to antibacterial drugs than cKp, and one ESBLs-producing hvKp strain was detected. The main capsular serotype of hvKp were K2, K57 and K1. PFGE indicated that the 59 strains of hvKp could be classified into 51 PFGE band types, forming 6 PFGE clusters. CONCLUSIONS: In this study, the detection rate of hvKp was 52.21% (59/113) identified by virulence genes. People with older ages or a higher PMN cell count are more likely to gain hvKp infection. ESBLs-producing hvKp is emerging, indicating the importance of epidemiologic surveillance and clinical awareness of this pathogen in this region.

Design, Synthesis, and Bioactivity of Cyclic Lipopeptide Antibiotics with Varied Polarity, Hydrophobicity, and Positive Charge Distribution.

Twenty-three polymyxin analogs with variations at nine amino acid positions were synthesized and assessed for antimicrobial activity and renal cytotoxicity. Compounds M2, 14, S2, and 16 (MIC = 0.125-4 µg/mL) had similar or stronger activities against susceptible and drug-resistant strains of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii compared to polymyxin B (MIC = 1-2 µg/mL). Most synthesized compounds (50% cytotoxic concentration, CC50 ≥ 200 µg/mL) exhibited lower cytotoxicity than polymyxin B (CC50 = 99 ± 6 µg/mL). Polymyxin S2 showed high plasma stability in vitro and strong efficacy in a mouse systemic infection model (ED50 = 0.9 mg/kg) against NDM-1-producing Klebsiella pneumoniae, suggesting that it is a potential candidate for drug development. The activity and cytotoxicity results indicated that the amino acids at positions 2, 3, 6, and 7 might be replaced. Effects on activity and cytotoxicity linked to changes in the number of positively charged amino acids varied among different cyclopeptide skeletons, but the underlying mechanisms are unknown.

Development and validation of a sensitive LC-MS/MS method for the quantitation of IMB-YH-4py5-2H, an antituberculosis candidate, and its application to the pharmacokinetic study.

(E)-N,N-dimethyl-4-oxo-4-(4-(pyridin-4-yl)phenyl)but-2-enamide hydrochloride (IMB-YH-4py5-2H) is a novel Protein Kinase B (PknB) inhibitor with potent activity against Mycobacterium tuberculosis strains. In the present study, a sensitive and specific liquid chromatography/tandem mass spectrometry (LC-MS/MS) method was developed and validated to determine IMB-YH-4py5-2H in rat plasma. Sample pretreatment was achieved by liquid-liquid extraction with ethyl acetate, and separation was performed on an XTerra MS C18 column (2.1×50 mm, 3.5 µm) with gradient elution (methanol and 0.1% formic acid) at a flow rate of 0.3 mL/min. Detection was performed in multiple reaction monitoring (MRM) mode. Linear calibration curves were obtained over a concentration range of 1-100 ng/mL. The intra-day and inter-day precisions were lower than 8.46%, and the accuracies ranged from -8.71% to 12.36% at all quality control levels. The extraction recoveries were approximately 70%, and the matrix effects were negligible. All quality control samples were stable under different storage conditions. The validated method was successfully applied to a preclinical pharmacokinetic study in Sprague-Dawley rats. IMB-YH-4py5-2H demonstrated improved pharmacokinetic properties (higher exposure level) compared with its leading compound. IMB-YH-4py5-2H was also distributed throughout the lung pronouncedly, especially inside alveolar macrophages, indicating its effectiveness against lower respiratory infections.

Nanoliter-Scale Oil-Air-Droplet Chip-Based Single Cell Proteomic Analysis.

Single cell proteomic analysis provides crucial information on cellular heterogeneity in biological systems. Herein, we describe a nanoliter-scale oil-air-droplet (OAD) chip for achieving multistep complex sample pretreatment and injection for single cell proteomic analysis in the shotgun mode. By using miniaturized stationary droplet microreaction and manipulation techniques, our system allows all sample pretreatment and injection procedures to be performed in a nanoliter-scale droplet with minimum sample loss and a high sample injection efficiency (>99%), thus substantially increasing the analytical sensitivity for single cell samples. We applied the present system in the proteomic analysis of 100 ± 10, 50 ± 5, 10, and 1 HeLa cell(s), and protein IDs of 1360, 612, 192, and 51 were identified, respectively. The OAD chip-based system was further applied in single mouse oocyte analysis, with 355 protein IDs identified at the single oocyte level, which demonstrated its special advantages of high enrichment of sequence coverage, hydrophobic proteins, and enzymatic digestion efficiency over the traditional in-tube system.

Synthesis and Bioactivity Investigation of the Individual Components of Cyclic Lipopeptide Antibiotics.

In this paper, 26 natural polymyxin components and a new derivative S2 were synthesized, and their differences in efficacy and toxicity have been investigated. Almost all of the synthesized components showed strong activity against both susceptible and resistant strains of E. coli, K. pneumoniae, P. aeruginosa, and A. baumannii. The toxicities were obviously different between the components. Only some of the components were tested for toxicity in vivo. Compounds E2, E2-Val, A2, M2, D2, and S2 showed obviously lower renal cytotoxicity and acute toxicity than polymyxins B and E. The in vivo nephrotoxicity of E2, M2, and S2 was similar to that of polymyxin E. Compound S2, with four positive charges, was especially interesting as it possessed both increased efficacy and decreased toxicity. The SAR and toxicity studies indicated that further structural modification could concentrate on polymyxin S. The results also indicated that S2 could be a new drug candidate.

Ninety-Day Subchronic Oral Toxicity Study of Senecio scandens Extract in Rats.

The present study assessed the safety/toxicity of Senecio scandens, a well-known Chinese herb that is used as an anti-inflammatory, antibiosis, and antipyretic drug. A 90-d subchronic oral toxicity study of S. scandens was performed in Wistar rats. The extract of S. scandens was administered orally to male and female rats at a single dose of 225, 450, and 900 mg/kg/d. There was no obvious toxicity. Certain changes in hematology and coagulation parameters (red cell distribution width (RDW), platelet count (PLT), monocyte percentage (Mo%), activated partial thromboplastin time (APTT), prothrombin time (PT)) were observed in some administration groups. In regards to the blood biochemical parameters, the levels of creatinine (CRN), potassium, and chloride were increased in a number of the treated rats. There were no significant changes in other hematology, coagulation, or biochemical parameters in rats orally administered S. scandens. S. scandens has a slight effect on rat coagulation and metabolism systems. The herb was safe at all doses tested, but caution should be taken when administering S. scandens at higher doses.

In vivo antibacterial activity of MRX-I, a new oxazolidinone.

MRX-I is a potent oxazolidinone antibiotic against Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus (MRSA), penicillin-resistant Streptococcus pneumoniae (PRSP), penicillin-intermediate S. pneumoniae (PISP), and vancomycin-resistant enterococci (VRE). In this study, the in vivo efficacy of orally administered MRX-I was evaluated using linezolid as a comparator. MRX-I showed the same or better efficacy than linezolid in both systemic and local infection models against the tested strains.

[Correlation study on Chinese medical syndrome types of chronic hepatitis B patients and HLA-DR13 gene, BCP mutation, and T-lymphocyte subsets].

OBJECTIVE: To explore the correlation between the HLA-DR13, basic core promoter (BCP), changes of T lymphocyte subset and clinical Chinese medical syndromes of chronic hepatitis B (CHB). METHODS: Totally 102 CHB patients were syndrome typed as Gan depression Pi deficiency syndrome (GDPDS), Pi-Shen yang deficiency syndrome (PSYDS), Gan-gallbladder dampness heat syndrome (GGDHS), Gan-Shen yin deficiency syndrome (GSYDS), and static blood blocking collaterals syndrome (SBBCS). Besides, 30 healthy subjects were recruited as the normal control group. The blood HBV-DNA level and HLA-DR13 gene were detected with real time fluorescent PCR. The expression of CD4+ and CD8+ in T lymphocytes was detected using flow cytometry. The mutation of serum A1762T/G1764A was detected using PCR sequencing. Hepatitis Be antigen (HBeAg) was detected with ELISA, and correlation between various Chinese medical syndrome types and objective indicators were analyzed. RESULTS: There was no statistical difference in HBV-DNA quantitative results among various syndrome types (P > 0.05). HBeAg positive rate was higher in GDPDS than in other syndrome types (P < 0.05). It was sequenced as GDPDS > GSYDS > SBBCS > GGDHS > PSYDS. Compared with the normal control group, percentages of CD3+ and CD3+ CD4+ were lower in PSYDS (P < 0.05). The ratio of CD3+ CD4+/CD3+ CD8 was lower in GGDHS and PSYDS than in the normal control group (P < 0.05). There was no statistical difference in the CD3+ CD8+ percentage among various syndrome types (P > 0.05). The quantitation of HLA-DR13 gene was lower in GDPDS and GSYDS than in the normal control group (P < 0.05). The positive rate of BCP mutation was higher in GSYDS than in other syndrome types (P < 0.05). CONCLUSION: Co-detection results of HLA-DR13 and BCP could be used as reference indices of Chinese medical syndrome typing of CHB.

Euphorbia kansui roots induced-diarrhea in mice correlates with inflammatory response.

AIM: Euphorbia kansui (E. KS) is a traditional medicine used in China for thousands of years with the effect of propulsion in the gastrointestines. However, there is no reported study of E. KS on gastrointestinal motility until now. The aim of this work is to study the effect of E. KS on the propulsion of gastrointestines, and to elucidate the possible mechanism of action. METHODS: E.KS was prepared as a 30% ethanol extract and used for the experiment of small and large intestines of mice by oral administration with three different dosages (1.2, 0.6 and 0.3 g·kg(-1)). The feces were observed in vivo. The morphology was carried out to detect if there are any changes in the intestines after the extract of E. KS administration. The assays of mRNA and protein expression were employed to observe IL-1ß, TNFα and caspase 3. RESULTS: It was shown that the extract of E.KS promoted diarrhea in mouse feces after administration, inhibited the contraction of smooth muscle of mouse small intestine and caused the inflammatory exudation on the mucosa of the intestines, enhanced the expression of both mRNA and the protein levels of IL-1ß and TNFα in the small or large intestines. CONCLUSION: The results showed that the extract of E. KS acted on the intestinal smooth muscle with propulsion of feces involving the irritation of the intestines with acute inflammatory reactions.

[Treatment of complicated cavernous venous malformation with retained copper wires combined with pingyangmycin injection].

OBJECTIVE: To evaluate the therapeutic effect of retained copper wires combined with pingyangmycin (PYM) injection for complicated cavernous venous malformation. METHODS: The location of venous malformation was detected by physical examination and MRI. The copper wires in 0.2 mm width were used to puncture the lesion repeatedly and retained in the lesion to form a net. After that, 8 mg PYM was injected into the residue malformed veins. 8-10 days later, the copper wires were taken out and necrotic tissue was squeezed out. The wounds of punctual holes healed through dressing. The patients received postoperative MRI to evaluate the therapeutic effect. RESULTS: From Jan. 2002 to Dec. 2008, 45 cases were treated. The patients were followed up for 1-3 years. 51.1% (23/45) of the lesions shrinked markedly or even disappeared. 42.2% (19/45) of the lesions reduced. 6.67% (3/45) of the lesions didn't change. There was no complication like invasive infection. CONCLUSIONS: It is very effective to treat complicated cavernous venous malformation with retained copper wires combined with pingyangmycin injection.

[Antivirus effects of extract from gardenia].

OBJECTIVE: To observe the effect of the extract from gardenia on influenza viral pneumonia in mice and virus-induced cytopathic effect. METHOD: The mice were infected by influenza virus in nasal, the lung inflammation, mortality rate and life elongation rate were observed respectively. The anti-viral activity of the extract from gardenia was accessed by cytopathic effect (CPE) in vitro and 0% toxicity concentration (TC0), 50% toxicity concentration (TC50), 50% inhibitor concentration (IC50), therapeutic index (TI) were determined by Reed-Muench method. RESULT: The pneumonia induced by influenza virus in mice was inhibited significantly by the extract from gardenia, as the mortality rate decreased and the life elongation rate increased remarkably. Meanwhile the NO content in serum decreased significantly; The cytopathic effect induced by six kinds of viruses was inhibited remarkably. CONCLUSION: The six kinds of viruses were inhibited significantly by the extract from gardenia which inhibitory effect on mice influenza viral pneumonia was related to the NO content decreased.

[Isolation and structure identification of chemical constituents from the seeds of Descurainia sophia (L.) Webb ex Prantl].

AIM: To isolate and determine the structures of chemical constituents from the seeds of Descurainia sophia (L.) Webb ex Prantl. METHODS: The chemical constituents were extracted from the seeds of Descurainia sophia (L.) Webb ex Prantl with 75% ethanol and purified by polyamide, silica gel, RP-C18 and Sephadex LH-20 on column chromatography. Chemical methods and spectroscopic methods, such as 1H and 13CNMR, HSQC, HMBC and TOCSY spectra were used for the structural identification. RESULTS: Fifteen compounds were obtained. Twelve of them were identified as quercetin-3-O-beta-D-glucopyranosyl-7-O-beta-gentiobioside (I), kaempferol-3-O-beta-D-glucopyranosyl-7-O-beta-gentiobioside (II), isorhamnetin-3-O-beta-D-glucopyranosyl-7-O-beta-gentiobioside (III), quercetin-7-O-beta-gentiobioside (IV), kaempferol-7-O-beta-gentiobioside (V), isorhamnetin-7-O-beta-gentiobioside (VI), quercetin-3,7-di-O-beta-D-glucopyranoside (VII), kaempferol-3, 7-di-O-beta-D-glucopyranoside (VIII), isorhamnetin-3, 7-di-O-beta-D-glucopyranoside (IX), kaempferol-3-O-beta-D-glucopyranosyl-7-O-[(2-O-trans-sinnapoyl)-beta-D- glucopyranosyl(1-->6)]-beta-D-glucopyranoside) (X), sinapic acid ethyl ester (XI) and 3, 4, 5-trimethoxyl-cinnamic acid (XII). CONCLUSION: Compounds X and VI are new compounds. IV, V, VII, VIII and IX were isolated from Cruciferae family for the first time. I, II, III were obtained from Descurania genus and XI, XII from D. sophia for the first time.

[Determination of quercetin-3-O-beta-D-glucopyranosyl-7-O-beta-D-gentiobioside in semen descurainiae by HPLC].

OBJECTIVE: To establish a method for the determination of quercetin-3-O-beta-D-glucopyranosyl-7-O-beta-D-gentiobioside in Semen Descurainiae. METHOD: HPLC was used with self-made quercetin-3-O-beta-D-glucopyranosyl-7-O-beta-D-gentiobioside as reference substances. RESULT: The average collection was 99.78%, RSD 2.4%. CONCLUSION: The method is appropriate for quality control of Semen Descurainiae.