Fusidic Acid and Its Major Active Metabolite Penetration into Cerebrospinal Fluid for Assessing Treatment of Intracranial Infections.

Fusidic acid (FA) had excellent antimicrobial effects due to its unique mechanism of action. Since 1962, FA has been widely used in the systemic and topical treatment of staphylococcal infections and exhibits a well-characterized potency against methicillin-susceptible Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and methicillin-resistant coagulase-negative Staphylococci. In view of the spectrum of activity, no cross-resistance with other clinically used antibiotics, and potential penetration into brain tissue, FA was used to treat possible gra-positive bacteria in 3 patients with intracranial infections in the present report. FA and its active metabolite (3-keto FA) were measured in plasma and cerebrospinal fluid (CSF) to assess the treatment of FA, and the results indicated that 1,500 mg per day of FA was sufficient to achieve therapeutic concentrations in both plasma and CSF in intracranial infection patients, while the dosage did not experience unexpected regimen-related toxicity.

Determination of Total and Unbound Meropenem, Imipenem/Cilastatin, and Cefoperazone/Sulbactam in Human Plasma: Application for Therapeutic Drug Monitoring in Critically Ill Patients.

BACKGROUND: Critically ill patients show several pathophysiological alterations that can complicate antibiotic dosing. Hence, there is a strong rationale to individualize anti-infective dosing in these patients by using therapeutic drug monitoring (TDM). The current study aimed to develop and validate a liquid chromatography-tandem mass spectrometry method for the simultaneous determination of total and unbound plasma concentrations of 3 commonly used antibiotics (meropenem, imipenem/cilastatin, and cefoperazone/sulbactam) in the treatment of infections in critically ill patients in China, which could be suitable for routine TDM in hospital laboratories. METHODS: The unbound drug was separated from the bound drug by ultrafiltration. Simple protein precipitation was used for sample preparation. Meropenem, imipenem/cilastatin, cefoperazone/sulbactam, and their corresponding internal standards were then resolved using the Waters CORTECS C18 column. All the compounds were detected using electrospray ionization in the positive/negative ion-switching mode. RESULTS: The calibration curves were linear for all compounds, with correlation coefficients (R) above 0.99 for total concentrations in human plasma and unbound concentrations in the plasma ultrafiltrate. For both total and unbound drugs, the relative errors and intra-assay/interassay relative standard deviations were below 15%. The limit of quantification was 0.05 mcg/mL for both total plasma concentrations and plasma ultrafiltrate concentrations of all compounds. CONCLUSIONS: The method was simple, rapid, and reliable and is currently being used to provide a TDM service to enhance the efficacious use of the 3 antibiotics.

Structural characterization and antioxidant activity of a heteropolysaccharide isolated from Hedysarum polybotrys.

A water-soluble polysaccharide (HPS3aS) with a molecular mass of 1.22 × 10(4) Da was isolated from Hedysarum polybotrys using anion-exchange and gel-permeation chromatography. HPS3aS exhibits a globular-shaped conformation in 0.1 M NaNO3 by size exclusion chromatography with multi-angle laser light scattering (SEC-MALLS). The investigation of the structural features of this heteropolysaccharide through a combination of chemical and instrumental analyses revealed that the backbone of HPS3aS is composed of α-D-(1 → 4)-linked glucopyranose residues, which occasionally branched at O-6. The branches are composed of (1 → 4)-linked galactopyranose residues and terminated with glucopyranose residues. HPS3aS possesses good in vitro antioxidant activity, as evaluated by scavenging assays with 1,1-diphenyl-2-picrylhydrazyl, hydroxyl, and superoxide radicals, which suggests that HPS3aS could be a potential antioxidant.

[Spectrum-effect relationship of reducing phlegm effect of Peucedanum harrysmithii var. subglabrum].

OBJECTIVE: To analyze the relationship between high-performance liquid chromatography (HPLC) fingerprints of the chloroform extract fractions of Peucedanum harrysmithii var. subglabrum (PHS) and its phlegm-reducing effect, in order to establish "active component group for reducing phlegm". METHOD: HPLC was adopted to determine and analyze HPLC fingerprints of chloroform extract fractions of PHS. Phenol red expectorant experiment was used to observe the phlegm-reducing effect in mice. Mice were administered intragastrically with chloroform extract fractions for 6 days (1.4 g x kg(-1)), with acute bronchitis syrup as the positive control drug (12 mL x kg(-1)). The phenol red secretion in mice was determined by spectrophotometer. Then the grey relational analysis was used to study the spectrum-effect relationship. RESULT: The phlegm-reducing effect of the chloroform extract fractions of PHS were resulted from the combined effect of all of its chemical components. Its various characteristic peaks represented different chemical components, and the order of their contributions to the phlegm-reducing effect was (number of peaks) 13 > 12 > 16 > 18 > 19 > 6 > 20 > 14 > 1 > 11 > 15 > 10 > 17 > 2 > 5 > 4 > 7 > 3 > 8 > 9, in No. 1, 3, 4, 10, 13 and 16 characteristic peaks were identified as marmesin, psoralen, xanthotoxin, Pd-Ib, pteryxin and peuformosin. CONCLUSION: The chloroform extract fractions of PHS show strongly phlegm-reducing effect. There may be certain relationship between their HPLC fingerprint and phlegm-reducing effect.