[Overview of Status of Medical Device Registration and Quality Evaluation Requirements for Clinical Mass Spectrometry].

Mass spectrometry technology is becoming an important tool for clinical analysis due to its high specificity, high sensitivity and high multi-component detection capability. The current applications of this technology are mainly in liquid chromatography-tandem mass spectrometry (LC-MS/MS), matrix-assisted laser desorptionionization time-of-flight mass spectrometry (MALDI-TOF-MS), inductively coupled plasma mass spectrometry (ICP-MS), gas chromatography-mass spectrometry (GC-MS) and the related in vitro diagnostic kits. At present, the number of medical device (MD) based on mass spectrometry technology is growing rapidly, especially the number of LC-MS/MS and MALDI-TOF-MS registered MD products, and the standardization of relevant product quality requirements is also being effectively carried out. In general, clinical mass spectrometry equipment is still mainly imported, and the equipment price is relatively high. The development of mass spectrometry kits is mainly based on imported platforms, and domestic equipment is still in its infancy; the further promotion of clinical application of mass spectrometry also depends on the progress of the automation and standardization of the analysis procedure. To investigate the detection performance of mass spectrometry systems, it is necessary to fully consider the characteristics of mass spectrometry technology itself.

Comparative study of plasma clearance of iohexol at different injection doses.

BACKGROUND: Our goal was to compare the metabolic curves of plasma clearance of iohexol (ClIOH) at standard dose (5 ml) and contrast-level dose (50 ml). METHODS: The concentration of iohexol was measured at fasting state and at nine different time periods after a single bolus of iohexol injection. The interval between the injection of the two doses was longer than 24 hrs. Using a multi-point method and a dual-sample method, ClIOH-M and ClIOH-D were calculated, and the correlation and consistency of ClIOH between the two doses were compared. RESULTS: The metabolic curves of iohexol at the 5 ml and 50 ml injection were substantially identical. The correlation of ClIOH-M between the two doses was 0.930, the mean deviation was 1.3 ± 6.9 ml/min/1.73 m2. Taking ClIOH-5ml-M as the standard, the ClIOH-50ml-D at 2 h and 4 h had a correlation coefficient of 0.975, a mean deviation of 0.1 ± 5.3 ml/min/1.73 m2, and the concordances were 100% corresponding to P30, 88.9% corresponding to P10, and 77.8% corresponding to P5. CONCLUSION: When a regular dose of iohexol is used for enhanced CT, ClIOH can be used for the measurement of GFR, and a proper time for blood collection can be 2 h and 4 h.

Repeated-dose (28 days) oral toxicity study in rats of an antiacne formula (BC-AF) derived from plants.

To evaluate the safety of a formula (BC-AF) consisting of the extracts of danshen (Salvia miltiorrhiza), loquat leaf (Glycyrrhiza uralensis), and licorice (Eriobotrya japonica), a preliminary 28-day, repeated-dose oral toxicity study was performed in Sprague-Dawley rats. Eighty animals were divided into four groups, with each group comprising 10 male and 10 female rats. BC-AF was administered once-daily by oral gavage at doses of 0 (control), 2.5 (low), 5 (middle), and 10 (high) g/kg body weight successively for each group for 28 days, respectively. Rats in all groups were sacrificed on day 29, except half of the males and females in the high-dose group that were kept for an additional 2 weeks to observe any possible toxicity after drug withdrawal. In 4 weeks, there were no toxicity reactions or abnormal deaths in any animal groups. There was no significant difference, in comparison to the control group, in clinical signs, organ weights, hematological and serological parameters, or histopathologic findings. In conclusion, the 28-day repeated-dose oral toxicity study demonstrates that BC-AF produced no effects in either male or female rats following oral administration of up to 10 g/kg.

713A, a new metabolite isolated from a fungal strain 713.

A new compound named 713A was isolated from the fermentation broth of a fungal strain 713. The structure of 713A was elucidated by spectroscopic methods. In the screening for interleukin-6 (IL-6) receptor antagonist, 713A exhibited inhibitory activity to the binding of IL-6 and IL-6 receptor with an IC50 value of 8.6 microM.

4849F, a new metabolite produced by the Streptomyces sp. 4849 as an inhibitor of IL-4 receptor.

A new compound named 4849F was isolated from the Streptomyces sp. 4849. The structure of 4849F was elucidated by spectroscopic analyses. The immobilized ligand-binding assay showed that 4849F can competitively inhibit the binding of IL-4 with IL-4 receptor in a dose dependent manner with an IC50 value of 6.7 microM.

Isoprenylated xanthones and flavonoids from Cudrania tricuspidata.

Further phytochemical investigation on the roots of Cudrania tricuspidata afforded a new isoprenylated xanthone, cudratricusxanthone I (1), two new isoprenylated flavanones, cudraflavanones C and D (2 and 3, resp.), and seven known compounds, 1,7-dihydroxy-3,6-dimethoxyxanthone (4), macluraxanthone C (5), cudraxanthones E, K, and L (6, 7, and 8, resp.), cudraflavanone A (9), and cudraflavone C (10). Their structures were identified by spectroscopic methods. Cudratricusxanthone H (12), macluraxanthone B (13), two xanthones previously isolated from this plant, and 5, showed significant inhibitory effects on four kinds of human digestive apparatus tumor cell lines (HCT-116, SMMC-7721, SGC-7901, and BGC-823) with IC50 values of 2.70-12.66 microM.

Cytotoxic isoprenylated xanthones from Cudrania tricuspidata.

Eight new isoprenylated xanthones, cudratricusxanthones A-H (1-8), were isolated from the roots of Cudrania tricuspidata, together with ten known compounds, cudraxanthones H (9) and M (10), xanthone V(1a) (11), toxyloxanthone C (12), macluraxanthone B (13), 1-hydroxy-3, 6, 7-trimethoxyxanthone (14), cycloartocarpesin (15), artocarpesin (16), cudraflavone B (17), and kaempferol (18). Their structures were characterized by spectroscopic methods. Xanthones 5, 7, 10, and 12 showed inhibitory effects on four kinds of human digestive apparatus tumor cell lines (HCT-116, SMMC-7721, SGC-7901, and BGC-823) with IC(50) values of 1.6-11.8 microg/mL. Xanthones 2, 4, and 11 displayed significant cytotoxicity against HCT-116, SMMC-7721, and SGC-7901 (IC(50)=1.3-9.8 microg/mL). Flavonoids 15-17 were almost inactive.