The favorable biocompatibility of dental biomaterial is very important, which guarantees the safety and effectiveness of its clinical application. The cytotoxicity test, as one of the biological evaluation screening tests, is known to be an important and frequently used method to evaluate biocompatibility of biomaterials. This text is devoted to an overview of the cytotoxicity test for dental materials.
Biocompatible Materials ; toxicity ; Biological Assay ; methods ; trends ; Dental Materials ; toxicity ; Humans ; Materials Testing ; methods

Using fluorescein diacetate labeled HK-2 cells, a fast method for screening nephrotoxic components in traditional Chinese medicines (TCMs) was proposed in this study. The methodology validation showed that the linearity, stability and accuracy of the proposed method were suitable for screening nephrotoxic components in vitro . This method was further applied on screen 352 components from 32 Chinese Pharmacopoeia-indexed toxic TCMs. The results indicated that 31 components from 14 toxic TCMs, including Badou, had significant toxicity on HK-2 cells, which suggested these components may cause nephrotoxicity. The components from the other 18 toxic TCMs had no significant toxicity on HK-2 cells.
Biological Assay ; methods ; Cell Line ; Drugs, Chinese Herbal ; toxicity ; Fluorescent Dyes ; chemistry ; Humans ; Kidney ; drug effects

OBJECTIVETo develop an assay methodology for determination of lumbrukinase potency in Rongshuan capsules.

METHODThe agarose-fibrin plate assay methodology for determination of Lumbrukinase potency in Rongshuan capsules was studied including durability, specificity, linearity range, product's handling method, accuracy , repetitiveness, solution stability, recovery and statistical method. The method of parallel line assay based on quantitative responses in statistical methods for biological assays was used in the statistics of potency assay.

RESULTThe durability and specificity of assay accord with the requirement; The linearity range was 12.5 to approximately 400 U, the RSD of accuracy tests was 3.2%, the RSD of repetitiveness tests was 8.3%, the solution is stable under 4 degrees C for 72 hours, the recovery rate was 97.0% and the RSD of recovery assays was 16.5%.

CONCLUSIONThe agar-fibrin plate assay is rapidly, feasible, simple, convenient and accurate way for determining the Lumbrukinase potency. The method of parallel line assay based on quantitative responses in statistical methods for biological assays can control the error of determination.

Animals ; Biological Assay ; methods ; Capsules ; analysis ; Endopeptidases ; analysis ; Pharmaceutical Preparations ; analysis

AIMTo study the pharmacokinetic (PK) properties in rabbits treated with N-Ile(1)-Thr(2)-63-desulfato-r-hirudin (rH) newly developed in China by means of bioassay in order to provide preclinical experiment basis for its development as a novel anticoagulant agent.

METHODSrH plasma concentration was determined using bioassay based on ex vivo antithrombin activity of rH. Normal rabbits received iv rH 4.0, 2.0 and 1.0 mg/kg or sc rH 2.0 mg/kg, respectively. The rabbits with acute severe renal failure were given iv rH 2.0 mg/kg.

RESULTSThe bioassay described in this paper met requirements for study of PK in rabbits. The major PK parameters after iv dosing were as follows: t(1/2beta) 58.4-59 min. V(d) 0.09-0.12 L/kg, CL 0.0035-0.0040 L/(kg.min); AUC were proportional to the doses, t(1/2) and CL did not change significantly with the doses. The sc bioavailability reached 94%. The rabbits suffering from acute severe renal failure presented 11-fold longer t(1/2beta) and 13-fold greater AUC than normal healthy rabbits.

CONCLUSIONrH exhibited rapid elimination, distribution was only limited to extracellular space and good absorption from sc site. The excretion of rH by kidneys played a very important role in the elimination of rH. The PK of rH could be described by the two- and one-compartment model after iv and sc dosing, respectively, and followed linear kinetics.

Algorithms ; Animals ; Biological Assay ; methods ; Computer Simulation ; Hirudins ; blood ; pharmacokinetics ; Metabolic Clearance Rate ; Models, Biological ; Rabbits ; Reproducibility of Results ; Sensitivity and Specificity ; Thrombin Time ; methods

OBJECTIVETo develop a method for simultaneous assay of propulsion and absorption in small intestine.

METHODSThe mice were administrated through gastric tube with mixed reagents containing 0.12% phenol red, D-xylose (1.25%, 2.5% and 5%) and 15% gelatin. The influence of phenol red on D-xylose absorption and the influence of D-xylose on small intestine propulsion rate were investigated by measuring serum concentration of D-xylose with phloroglucinol method.

RESULTSAt 10 min, no significant difference was found between 5% D-xylose mixed reagent group and 5% D-xylose control. At 15 min, small intestine propulsion rate in 5% D-xylose mixed reagent group, but not in 2.5% and 1.25% D-xylose mixed reagent groups, was significantly higher than in phenol red control (P<0.05).

CONCLUSIONGastric administration of mixed reagent containing 0.12% phenol red, 5% D-xylose and 15% gelatin can simultaneously assay propulsion and absorption of small intestine in mice.

Animals ; Biological Assay ; methods ; Intestinal Absorption ; Intestine, Small ; metabolism ; physiology ; Male ; Mice ; Mice, Inbred ICR ; Peristalsis ; Phenolsulfonphthalein ; pharmacokinetics ; Xylose ; pharmacokinetics

To investigate the feasible application of the bioassay method in the evaluation of traditional Chinese medicine sustained-release preparations, develop a rapid drug-release evaluation method in vitro for multi-component preparations, and replace the biological activity determination method characterizing the overall behavior with the existing drug-release evaluation method for single component, in order to give better instruction for sustained-release preparations. HPLC was adopted to determine dissolution media, drug releasing rates, and accumulative releasing of active ingredients (salvianolic acid B, protocatechuic aldehyde and rosmarinic acid) of Salvia Miltiorrhiza hydrophilic gel matrix tablets. The ultraviolet spectroscopy was adopted to determine the antioxidant activity of release media, and evaluate the correlation between the drug-time curve of various drug components and the drug-time curve of the total antioxidant activity. The correlation coefficient between the drug-release curve of various components and the drug-time curve of the total antioxidant activity was higher than the critical value r 0.898 (P < 0.001). This indicated that the drug-release curve of the three phenolic acids and the drug-time curve of the total antioxidant activity had a good correlation in different conditions, such as dissolution media, release rates and component ratios. The bioassay method for determination was feasible, simple and convenient for preparation quality evaluation and prescription design in the place of in vitro dissolution.
Antioxidants ; chemistry ; Biological Assay ; methods ; Delayed-Action Preparations ; chemistry ; Drugs, Chinese Herbal ; chemistry ; Kinetics ; Salvia miltiorrhiza ; chemistry ; Solubility ; Tablets ; chemistry

BACKGROUND: The increasing prevalence of drug-resistant tuberculosis (TB) infection represents a global public health emergency. We evaluated the usefulness of a newly developed multiplexed, bead-based bioassay (Quantamatrix Multiplexed Assay Platform [QMAP], QuantaMatrix, Seoul, Korea) to rapidly identify the Mycobacterium tuberculosis complex (MTBC) and detect rifampicin (RIF) and isoniazid (INH) resistance-associated mutations. METHODS: A total of 200 clinical isolates from respiratory samples were used. Phenotypic anti-TB drug susceptibility testing (DST) results were compared with those of the QMAP system, reverse blot hybridization (REBA) MTB-MDR assay, and gene sequencing analysis. RESULTS: Compared with the phenotypic DST results, the sensitivity and specificity of the QMAP system were 96.4% (106/110; 95% confidence interval [CI] 0.9072–0.9888) and 80.0% (72/90; 95% CI 0.7052–0.8705), respectively, for RIF resistance and 75.0% (108/144; 95% CI 0.6731–0.8139) and 96.4% (54/56; 95% CI 0.8718–0.9972), respectively, for INH resistance. The agreement rates between the QMAP system and REBA MTB-MDR assay for RIF and INH resistance detection were 97.6% (121/124; 95% CI 0.9282–0.9949) and 99.1% (109/110; 95% CI 0.9453–1.0000), respectively. Comparison between the QMAP system and gene sequencing analysis showed an overall agreement of 100% for RIF resistance (110/110; 95% CI 0.9711–1.0000) and INH resistance (124/124; 95% CI 0.9743–1.0000). CONCLUSIONS: The QMAP system may serve as a useful screening method for identifying and accurately discriminating MTBC from non-tuberculous mycobacteria, as well as determining RIF- and INH-resistant MTB strains.
Biological Assay ; Emergencies ; Isoniazid ; Mass Screening ; Methods ; Mycobacterium tuberculosis* ; Mycobacterium* ; Prevalence ; Public Health ; Rifampin ; Sensitivity and Specificity ; Seoul ; Tuberculosis, Multidrug-Resistant

OBJECTIVETo establish an early diagnostic method for detecting female genital tuberculosis.

METHODSEighty-six women with genital tuberculosis during January 2005-September 2007 were examined by phage amplified biological assay, and the results were compared with those from leucorrhea culture, smear and PCR.

RESULTSForty-five patients were tuberculosis positive with 100% of specificity identified by phage amplified biological assay. Twenty patients were tuberculosis positive by PCR. Five patients were culture-positive tuberculosis and no case had smear-positive tuberculosis.

CONCLUSIONPhage amplified biologically assay is sensitive and specific, which could be used for the early diagnosis of female genital tuberculosis.

Adolescent ; Adult ; Bacteriological Techniques ; methods ; Bacteriophages ; Biological Assay ; methods ; Early Diagnosis ; Female ; Humans ; Sensitivity and Specificity ; Tuberculosis, Female Genital ; diagnosis ; Young Adult

BACKGROUNDCD4 count is used to determine antiretroviral therapy (ART) eligibility. In China, flow cytometers are mostly located in urban areas with limited access by patients residing in remote areas. In an attempt to address this issue, we conducted a study to validate the performance of Alere PIMA point-of-care CD4 analyzer.

METHODSVenous and finger-prick blood specimens were collected from HIV-positive participants from two voluntary counseling and testing sites in Yunnan Province. Both venous and finger-prick blood specimens were tested with the PIMA analyzer. Venous blood specimens tested with the Becton Dickinson FACSCalibur were used as a reference.

RESULTSVenous specimens from 396 and finger-prick specimens from 387 persons were available for analysis. CD4 counts by PIMA correlated well with those from FACSCalibur with an R2 of 0.91 for venous blood and 0.81 for finger-prick blood. Compared to FACSCalibur, the PIMA analyzer yielded lower counts with a mean bias of - 47.0 cells/μl (limit of agreement, [LOA]: -204-110 cells/μl) for venous blood and -71.0 cells/μl (LOA: -295-153 cells/μl) for finger-prick blood. For a CD4 threshold of 350 cells/μl, the positive predictive value (PPV) of PIMA was 84.2% and 75.7% and the negative predictive value (NPV) was 97.6% and 95.8% for venous and finger-prick blood, respectively. For an ART threshold of 500 cells/μl, the corresponding PPV was 90.3% and 84.0% and NPV was 94.3% and 93.4%, respectively.

CONCLUSIONSCD4 counting using venous blood with PIMA analyzers is a feasible alternative to a large flow cytometer to determine ART eligibility.

Adolescent ; Adult ; Aged ; Biological Assay ; methods ; Blood Specimen Collection ; CD4 Lymphocyte Count ; methods ; Child ; China ; Female ; HIV Infections ; diagnosis ; Humans ; Male ; Middle Aged ; Sensitivity and Specificity ; Young Adult

OBJECTIVETo establish a rapid, inexpensive, and simple drug susceptibility test (DST) for Mycobacterium tuberculosis (M. tb) and evaluate its feasibility.

METHODWe used nitrate reductase combined with mycobacteriophage assay (PhaB-NRA) to test 49 clinical M. tb isolates of, and the results were compared with those of PhaB-NRA and traditional absolute concentration method.

RESULTSThe sensitivity, specificity, and accuracy of PhaB-NRA for rifampicin were 89.1%, 91.67%, and 89.8%; on the contrary, those of isonicotinyl hydrazide were 86.21%, 90.0%, and 87.8%, respectively. The coincidence between PhaB-NRA and traditional assay were 0.746 for rifampicin and 0.750 for isonicotinyl hydrazide.

CONCLUSIONSPhaB-NRA is an inexpensive, rapid, and simple DST method. It is a promising rapid screening technique for DST of M. tb.

Anti-Bacterial Agents ; pharmacology ; Biological Assay ; methods ; Humans ; Microbial Sensitivity Tests ; methods ; Mycobacteriophages ; physiology ; Mycobacterium tuberculosis ; drug effects ; Nitrate Reductase ; metabolism ; Rifampin ; pharmacology ; Sensitivity and Specificity