BACKGROUNDThe cytotoxicity of dermal substitutes may be increased by the very processes used to deplete the cells. The present research aimed to investigate the method for monitoring the cytotoxicity of cell-free dermal substitutes using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method.

METHODSThe cytotoxicity of four dermal substitutes was evaluated using the MTT method according to the standards set by the Chinese State Food and Drug Administration (SFDA). Swine acellular dermal matrix (SADM) and goat acellular dermal matrix (GADM) were produced using a repeated freeze-thaw method. Human dermal matrix glutaraldehyde composite (HADM-G) and SADM cross-linked with glutaraldehyde (SADM-G) were produced using conventional methods.

RESULTSThe cytotoxicity of all dermal substitutes ranged from Grade 0 to Grade 1, meeting the standards of the Chinese FDA. The OD(490) of both SADM and GADM was higher than that of either HADM-G or SADM-G (P < 0.05).

CONCLUSIONDermal substitutes produced by the freeze-thaw method are less cytotoxic than those produced using conventional methods.

Cell Line ; Humans ; Skin, Artificial ; adverse effects ; Tetrazolium Salts ; chemistry ; Toxicity Tests ; methods

A series of 119 Mycobacterium avium complex isolates were subjected to clarithromycin susceptibility testing using microplates containing 2,3-diphenyl-5-thienyl-(2)-tetrazolium chloride (STC). Among 119 isolates, 114 (95.8%) were susceptible to clarithromycin and 5 were resistant according to the new and the standard method. STC counts the low cost and reduces the number of procedures needed for susceptibility testing.
Clarithromycin/*pharmacology ; Culture Media ; Humans ; Microbial Sensitivity Tests/*methods ; Mycobacterium avium Complex/*drug effects/isolation & purification ; Tetrazolium Salts/*chemistry

A series of 119 Mycobacterium avium complex isolates were subjected to clarithromycin susceptibility testing using microplates containing 2,3-diphenyl-5-thienyl-(2)-tetrazolium chloride (STC). Among 119 isolates, 114 (95.8%) were susceptible to clarithromycin and 5 were resistant according to the new and the standard method. STC counts the low cost and reduces the number of procedures needed for susceptibility testing.
Clarithromycin/*pharmacology ; Culture Media ; Humans ; Microbial Sensitivity Tests/*methods ; Mycobacterium avium Complex/*drug effects/isolation & purification ; Tetrazolium Salts/*chemistry

The methanol extract from the leaves of Petasites japonicus Maxim (PJ) was studied for its (anti-)mutagenic effect with the SOS chromotest and reverse mutation assay. The (anti-)carcinogenic effects were evaluated by the cytotoxicity on human cancer line cells and by the function and the expression of gap junctions in rat liver epithelial cell. PJ extracts significantly decreased spontaneous beta-galactosidase activity and beta-galactosidase activity induced by a mutagen, ICR, in Salmonella (S.) typhimurium TA 1535/pSK 1002. All doses of the extract (0.08-100 mg/plate) decreased the reversion frequency induced by benzo (alpha)pyrene (BaP) in S. typhimurium TA 98. It decreased not only the spontaneous reversion frequency but also that induced by BaP in S. typhimurium TA 100. PJ extract showed greater cytotoxic effects on human stomach, colon and uterus cancer cells than on other cancer cell types and normal rat liver epithelial cells. Dye transfers though gap junctions were significantly increased by PJ extracts at concentrations greater than 200 microg/mL and the inhibition of dye transfer by 12-O-tetradecanoylphorobol-13-acetate (TPA) was obstructed in all concentrations of PJ. PJ significantly increased the numbers of gap junction protein connexin 43, and increased the protein expression decreased by TPA in a dose-dependent manner. Based on these findings, PJ is suggested to contain antimutagenic and anticarcionogenic compounds.
Animals ; Cell Line, Tumor ; Cell Survival/*drug effects ; Formazans/chemistry ; Gap Junctions/*metabolism ; Humans ; Mutagenicity Tests ; Petasites/*metabolism ; Plant Extracts/*pharmacology ; Plant Leaves/metabolism ; Rats ; Tetrazolium Salts/chemistry

As the incidence of nontuberculous mycobacterial infection has been increasing recently in Korea, the importance of drug susceptibility test for clinical isolates of mycobacteria has become larger. In this study we determined the antimicrobial susceptibility patterns of clinical isolates of M. fortuitum and M. abscessus in Korea, and evaluated the efficacy of a modified broth microdilution method using 2,3-diphenyl-5-thienyl-(2)-tetrazolium chloride (STC), in terms of its ability to provide accurate and easy-to-read minimal inhibitory concentration (MIC) endpoints for the susceptibility testing of rapidly growing mycobacteria. Most isolates of M. fortuitum and M. abscessus in Korea are susceptible or intermediately susceptible to amikacin, cefoxitin, ciprofloxacin, and clarithromycin. Many isolates of M. fortuitum are susceptible to doxycycline, sulfamethoxazole, and imipenem, while many M. abscessus isolates are resistant to these drugs. In the present study, the modified broth microdilution method using STC was found to be reliable, easy to read, and inexpensive for M. fortuitum and M. abscessus susceptibility testing. The modified colorimetric MIC testing method using STC was proven to be a useful surrogate for RGM antibiotic susceptibility testing.
Anti-Bacterial Agents/pharmacology ; Cefoxitin/pharmacology ; Chemistry, Pharmaceutical/methods ; Ciprofloxacin/pharmacology ; Clarithromycin/pharmacology ; Colorimetry/methods ; Drug Resistance, Bacterial ; Korea ; *Microbial Sensitivity Tests ; Mycobacterium/*metabolism ; Mycobacterium fortuitum/*metabolism ; Tetrazolium Salts/*pharmacology

OBJECTIVEThe purpose of this study was to evaluate the in vitro cytotoxicity of novel Comfort denture adhesive (Comfort-DA), which was developed by the authors, to human oral fibroblasts (HOFs).

METHODSA sample of Comfort-DA was prepared and extracted in culturing medium to prepare the eluate. Then the eluate was diluted by culturing medium to 50% and 75% concentration for the assessment of cytotoxicity by tetrazolium bromide (MTT) colorimetric assay. Wells containing fresh medium alone were served as control. Cell viability was recorded by optical density after culturing in an atmosphere of 5% CO2 and 95% air at 37 degrees C for 2, 3 and 4 days, respectively. The viability of HOF cells was evaluated by MTT assay to investigate cell proliferation. Optical density (OD) was measured by a spectrophotometer at 490 nm. Then evaluating the cytotoxicity grade in test groups according to the means of cell proliferation. ANOVA was used to test the statistical significance.

RESULTSThe statistical analysis of the results of MTT cytological assay indicated significant difference (P < 0.05) in OD (indicate cell viability) between all concentrations of Comfort-DA and the control at all incubation times. The results of cell proliferation percentage also showed that the cytotoxicity grade of tested material only displayed "0-2".

CONCLUSIONThe generally favorable in vitro cytotoxicity of the Comfort-DA formulations indicates that this product may be an efficacious denture adhesive.

Adhesives ; toxicity ; Adolescent ; Biocompatible Materials ; chemistry ; toxicity ; Cell Division ; drug effects ; Cell Survival ; drug effects ; Cells, Cultured ; Denture Retention ; Fibroblasts ; cytology ; drug effects ; Humans ; Male ; Periodontium ; cytology ; drug effects ; Tetrazolium Salts ; Thiazoles ; Toxicity Tests ; methods

OBJECTIVETo investigating the relation between the expression of P-glycoprotein and Glutathione transferase-pi and the chemoresistance.

METHODSThe expressions of these two proteins in patients with oral and maxillofacial squamous carcinoma and normal oral tissues were detected by immunohistochemistry.

RESULTSThe positive expression rate of P-gp and GST-pi in oral and maxillofacial malignant tumor was 57.1% and 53.6% respectively, and no expression in normal oral tissues; the expression of GST-pi was relevant to the resistance to cisplatin, while the expression of P-gp was relevant to the resistance to chemotherapeutic drug in general.

CONCLUSIONSThe method of immunohistochemistry combining MTT assay in vitro may become an efficient way to predict the sensitivity to chemotherapeutic drug.

ATP-Binding Cassette, Sub-Family B, Member 1 ; analysis ; Carcinoma, Squamous Cell ; chemistry ; drug therapy ; Drug Resistance, Neoplasm ; Facial Neoplasms ; chemistry ; drug therapy ; Formazans ; Glutathione S-Transferase pi ; Glutathione Transferase ; analysis ; Humans ; Immunohistochemistry ; Isoenzymes ; analysis ; Maxillary Neoplasms ; chemistry ; drug therapy ; Mouth Neoplasms ; chemistry ; drug therapy ; Tetrazolium Salts

OBJECTIVENeuroblastoma (NB) is a pediatric solid tumor derived from neural crest precursor cells. It is resistant to current therapeutic protocols, including high dose chemotherapy. The mechanisms of chemoresistance are very complex. The recent studies have shown that the levels of tyrosine kinase receptor B (TrkB) and brain-derived neurotrophic factor (BDNF) are high in NB tumors with poor prognosis. The aim of this research was to explore the effects of TrkB and BDNF levels on the chemotherapeutic sensitivity in neuroblastoma by using the NB cell line SH-SY5Y in vitro.

METHODSThe expression of TrkB protein was detected with Western-blot after the treatment with different concentrations of all trans-retinoic acid (ATRA). Cell survival rate was analyzed using MTT. Apoptosis was detected using flow cytometry (FCM) and a transmission electron microscope (TEM).

RESULTS(1) The expression of TrkB protein was undetectable in SY5Y. It was positive, however, after the treatment with ATRA (1, 10, 100 nmol/L) for five days. The level of TrkB protein was increased with adding of ATRA at different concentrations. (2) The difference of the survival and apoptotic rate between the BDNF (10 ng/ml) + ATRA (10 nmol/L) + cisplatin (CP, 5 microg/ml) group (survival rate 46.51% +/- 13.44%, apoptosis rate 11.79% +/- 1.53%) and the CP alone group (survival rate 38.51% +/- 9.66%, apoptosis rate 14.95% +/- 2.06%) was not statistically significant (P > 0.05). The survival rate of the BDNF (50 ng/ml and 100 ng/ml) + ATRA (10 nmol/L) + CP (5 microg/ml) group (66.85% +/- 18.39%, 94.30% +/- 10.71%) was greatly higher than CP alone group (P < 0.05, P < 0.01), whereas the apoptotic rate (9.36% +/- 1.03%, 5.20% +/- 1.99%) was significantly lower than that of the CP alone group (P < 0.01, P < 0.01). The survival rates of BDNF (100 ng/ml) + ATRA (10 nmol/L) + CP (5 microg/ml) group were higher than those of BDNF (50 ng/ml) + ATRA (10 nmol/L) + CP (5 microg/ml) group (P < 0.01), whereas the apoptotic rates were lower than those of BDNF (50 ng/ml) + ATRA (10 nmol/L) + CP (5 microg/ml) group (P < 0.05). There were no significant difference between the ATRA (1 nmol/L) + BDNF (50 ng/ml) + CP group (survival rate 45.33% +/- 11.83%, apoptosis rate 12.48% +/- 2.48%) and the CP alone group in the survival and apoptotic rates (P > 0.05). The survival rates of the ATRA (10 nmol/L, 100 nmol/L) + BDNF (50 ng/ml) + CP (61.62% +/- 18.53%, 105.02% +/- 5.55%) group were greatly higher than those of the CP alone group (P < 0.05, P < 0.01), whereas the apoptotic rate (9.36% +/- 1.03%, 5.05% +/- 1.88%) was significantly lower than that of the CDDP alone group (P < 0.05, P < 0.01). The survival rates of the ATRA (100 nmol/L) + BDNF (50 ng/ml) + CP group were higher than those of the ATRA (10 nmol/L) + BDNF (50 ng/ml) + CP group (P < 0.01), whereas the apoptotic rates were lower than the ATRA (10 nmol/L) + BDNF (50 ng/ml) + CP group (P < 0.01). (3) Some of the cells showed apoptotic changes in the CP alone group, whereas the intranuclear chromoplasma was well-distributed, the nuclear membrane was clear, and mitochondria, ribosome and solvent were present in the ATRA (10 nmol/L) + BDNF (50 ng/ml) + CP group.

CONCLUSIONSThe sensitivity of SY5Y to CP was affected by TrkB and BDNF. The higher the level of TrkB and BDNF was, the lower the sensitivity of SY5Y to CP.

Antineoplastic Agents ; administration & dosage ; pharmacology ; Apoptosis ; drug effects ; Blotting, Western ; Brain-Derived Neurotrophic Factor ; administration & dosage ; pharmacology ; Cell Line, Tumor ; Cell Survival ; drug effects ; Cisplatin ; administration & dosage ; pharmacology ; Dose-Response Relationship, Drug ; Drug Resistance, Neoplasm ; drug effects ; Flow Cytometry ; Humans ; Microscopy, Electron, Transmission ; Neuroblastoma ; drug therapy ; metabolism ; pathology ; ultrastructure ; Receptor, trkB ; metabolism ; Tetrazolium Salts ; chemistry ; Thiazoles ; chemistry ; Tretinoin ; administration & dosage ; pharmacology

AIMThe piezoelectric properties and cytotoxicity of a porous lead-free piezoelectric ceramic for use as a direct bone substitute were investigated.

METHODOLOGYCold isostatic pressing (CIP) was applied to fabricate porous lithium sodium potassium niobate (Li0.06Na0.5K0.44) NbO3 specimens using a pore-forming method. The morphologies of the CIP-processed specimens were characterized and compared to those of specimens made by from conventional pressing procedures. The effects of the ceramic on the attachment and proliferation of osteoblasts isolated from the cranium of 1-day-old Sprague-Dawley rats were examined by a scanning electron microscopy (SEM) and methylthiazol tetrazolium (MTT) assay.

RESULTSThe results showed that CIP enhanced piezoelectricity and biological performance of the niobate specimen, and also promoted an extracellular matrix-like topography of it. In vitro studies showed that the CIP-enhanced material had positive effects on the attachment and proliferation of osteoblasts.

CONCLUSIONNiobate ceramic generated by CIP shows a promise for being a piezoelectric composite bone substitute.

Animals ; Biocompatible Materials ; chemistry ; toxicity ; Bone Substitutes ; chemical synthesis ; toxicity ; Cell Adhesion ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Ceramics ; chemical synthesis ; toxicity ; Coloring Agents ; Electrochemistry ; Materials Testing ; Microscopy, Electron, Scanning ; Niobium ; toxicity ; Osteoblasts ; drug effects ; Oxides ; chemical synthesis ; toxicity ; Porosity ; Potassium ; toxicity ; Pressure ; Rats ; Rats, Sprague-Dawley ; Skull ; cytology ; Stress, Mechanical ; Surface Properties ; Tetrazolium Salts ; Thiazoles

OBJECTIVETo investigate the effect of estrogen (E2), progesterone(P4), and paclitaxel (taxol) on the growth of primary human ovarian cancer cells in vitro and the expression of Drosha.

METHODSHuman ovarian cancer cells were treated with estrogen, progesterone or in combination with paclitaxel in vitro. The inhibition rate of ovarian cancer cells was assessed by methyl thiazolyl tetrazolium (MTT) assay. Apoptosis rate and cell cycle were determined by FACS analysis. The relative abundence of Drosha expression was detected by real-time quantitative PCR (qRT-PCR) and Western blotting.

RESULTSThe inhibition rate of the estrogen group, progesterone group, paclitaxel group, E2(+)Taxol group, P4(+)Taxol group was (31.53 ± 8.21)%, (25.22 ± 15.50)%, (46.71 ± 4.25)%, (69.46 ± 3.71)%, and (47.35 ± 39.02)%, respectively, significantly higher than that of the control group (0%, P<0.05 for all). Relative to the ER (-) in ovarian cancer cells,Drosha mRNA expression level of estrogen group, progesterone group, paclitaxel group, E2(+) Taxol group,and P4(+)Taxol group was 1.62 ± 0.10,1.60 ± 0.10,1.75 ± 0.16,1.95 ± 0.20, and 1.53 ± 0.06, respectively, significantly higher than that of the control group (1.00, P<0.05 for all). Relative to the ER (+)in ovarian cancer cells,the Drosha mRNA expression level of estrogen group, progesterone group, paclitaxel group, E2(+)taxol group, and P4(+)Taxol group was 1.03 ± 0.14, 1.60 ± 0.09, 1.75 ± 0.16, 1.60 ± 0.10, 1.53 ± 0.06, respectively except estrogen group, significantly higher than that of the control group (1.00, P<0.05). Relative to the ER (-) in ovarian cancer cells, the Drosha protein expression levels of the control group, estrogen group, progesterone group, paclitaxel group, E2(+) taxol group, and P4(+) Taxol group were 0.25 ± 0.05, 0.87 ± 0.30, 0.85 ± 0.38, 1.30 ± 0.21, 1.75 ± 0.83, 1.62 ± 0.82, respectively, with a significant difference between the experimental groups and the control group (P<0.05). Relative to the ER(+)ovarian cancer cells, the Drosha protein expression levels in the estrogen group, progesterone group, paclitaxel group, E2(+) taxol group, and P4(+) taxol group, were 0.28 ± 0.16, 0.85 ± 0.38, 1.30 ± 0.21, 0.94 ± 0.18, and 1.62 ± 0.82, respectively except estrogen group, significantly higher than that of the control group (0.25 ± 0.05, P<0.05 for all).

CONCLUSIONSEstrogen and progesterone in combination with paclitaxel can inhibit the growth of human ovarian cancer cells in vitro, and affect the cell apoptosis rate. Estrogen and taxol can alter the cell cycle. Estrogen and progesterone combined with paclitaxel show tumor suppressing or sensitizing effect through upregulated Drosha expression, and are associated with the estrogen receptor expression.

Antineoplastic Agents, Phytogenic ; pharmacology ; Antineoplastic Combined Chemotherapy Protocols ; pharmacology ; Apoptosis ; Cell Cycle ; Cell Growth Processes ; drug effects ; Cell Line, Tumor ; Coloring Agents ; Drug Therapy, Combination ; Estrogens ; pharmacology ; Female ; Humans ; In Vitro Techniques ; Ovarian Neoplasms ; chemistry ; drug therapy ; metabolism ; pathology ; Paclitaxel ; pharmacology ; Progesterone ; pharmacology ; RNA, Messenger ; metabolism ; Receptors, Estrogen ; metabolism ; Ribonuclease III ; genetics ; metabolism ; Tetrazolium Salts ; Thiazoles ; Up-Regulation