Chemo-photothermal immunotherapy for eradication of orthotopic tumors and inhibition of metastasis by intratumoral injection of polydopamine versatile hydrogels

Cancer remains one of the leading causes of death globally and metastasis always leads to treatment failure. Here, we develop a versatile hydrogel loading photothermal agents, chemotherapeutics, and immune-adjuvants to eradicate orthotopic tumors and inhibit metastasis by combinational therapy. Hydrogel networks were synthesized via the thiol-Michael addition of polydopamine (PDA) with thiolated hyaluronic acid. PDA acted as a cross-linking agent and endowed the hydrogel with excellent photothermal property. Meanwhile, a chemotherapeutic agent, doxorubicin (DOX), was loaded in the hydrogel via π‒π stacking with PDA and an immune-adjuvant, CpG-ODN, was loaded via electrostatic interaction. The release of DOX from the hydrogel was initially slow but accelerated due to near infrared light irradiation. The hydrogels showed remarkably synergistic effect against 4T1 cancer cells and stimulated plenty of cytokines secreting from RAW264.7 cells. Moreover, the hydrogels eradicated orthotopic murine breast cancer xenografts and strongly inhibited metastasis after intratumoral injection and light irradiation. The high anticancer efficiency of this chemo-photothermal immunotherapy resulted from the strong synergistic effect of the versatile hydrogels, including the evoked host immune response. The combinational strategy of chemo-photothermal immunotherapy is promising for highly effective treatment of breast cancer.

Targeting a cryptic allosteric site of SIRT6 with small-molecule inhibitors that inhibit the migration of pancreatic cancer cells

SIRT6 belongs to the conserved NAD+-dependent deacetylase superfamily and mediates multiple biological and pathological processes. Targeting SIRT6 by allosteric modulators represents a novel direction for therapeutics, which can overcome the selectivity problem caused by the structural similarity of orthosteric sites among deacetylases. Here, developing a reversed allosteric strategy AlloReverse, we identified a cryptic allosteric site, Pocket Z, which was only induced by the bi-directional allosteric signal triggered upon orthosteric binding of NAD+. Based on Pocket Z, we discovered an SIRT6 allosteric inhibitor named JYQ-42. JYQ-42 selectively targets SIRT6 among other histone deacetylases and effectively inhibits SIRT6 deacetylation, with an IC50 of 2.33 μmol/L. JYQ-42 significantly suppresses SIRT6-mediated cancer cell migration and pro-inflammatory cytokine production. JYQ-42, to our knowledge, is the most potent and selective allosteric SIRT6 inhibitor. This study provides a novel strategy for allosteric drug design and will help in the challenging development of therapeutic agents that can selectively bind SIRT6.

Histone deacetylase inhibitors inhibit cervical cancer growth through Parkin acetylation-mediated mitophagy

Parkin, an E3 ubiquitin ligase, plays a role in maintaining mitochondrial homeostasis through targeting damaged mitochondria for mitophagy. Accumulating evidence suggests that the acetylation modification of the key mitophagy machinery influences mitophagy level, but the underlying mechanism is poorly understood. Here, our study demonstrated that inhibition of histone deacetylase (HDAC) by treatment of HDACis activates mitophagy through mediating Parkin acetylation, leading to inhibition of cervical cancer cell proliferation. Bioinformatics analysis shows that Parkin expression is inversely correlated with HDAC2 expression in human cervical cancer, indicating the low acetylation level of Parkin. Using mass spectrometry, Parkin is identified to interact with two upstream molecules, acetylase acetyl-CoA acetyltransferase 1 (ACAT1) and deacetylase HDAC2. Under treatment of suberoylanilide hydroxamic acid (SAHA), Parkin is acetylated at lysine residues 129, 220 and 349, located in different domains of Parkin protein. In in vitro experiments, combined mutation of Parkin largely attenuate the interaction of Parkin with PTEN induced putative kinase 1 (PINK1) and the function of Parkin in mitophagy induction and tumor suppression. In tumor xenografts, the expression of mutant Parkin impairs the tumor suppressive effect of Parkin and decreases the anticancer activity of SAHA. Our results reveal an acetylation-dependent regulatory mechanism governing Parkin in mitophagy and cervical carcinogenesis, which offers a new mitophagy modulation strategy for cancer therapy.

Discovery of novel diarylamides as orally active diuretics targeting urea transporters

Urea transporters (UT) play a vital role in the mechanism of urine concentration and are recognized as novel targets for the development of salt-sparing diuretics. Thus, UT inhibitors are promising for development as novel diuretics. In the present study, a novel UT inhibitor with a diarylamide scaffold was discovered by high-throughput screening. Optimization of the inhibitor led to the identification of a promising preclinical candidate,

Effect of Different Extracts and Monomers of Lepidium meyenii on Proliferation of Mouse Splenic Lymphocyte and Induction of IL-2 and TNF-α / 中国实验方剂学杂志

Objective:To explore effects of different extracts and monomers of <italic>Lepidium meyenii </italic>（Maca） on the proliferation of mouse splenic lymphocytes and induction of interleukin-2 （IL-2） and tumor necrosis factor-<italic>α</italic> （TNF-<italic>α</italic>） by observing their immunomodulatory effects. Method:An octadecylsilyl （ODS） column was used to enrich the methanol extract of <italic>L. meyenii</italic> in stages to obtain six fractions and three monomers. Different groups of extracts and monomers of <italic>L. meyenii </italic>at different doses were set up. Cell counting Kit-8 （CCK-8） was used to detect the effect on the proliferation of mitogen-free， concanavalin A （Con A）-induced， and lipopolysaccharides （LPS）-induced mouse splenic lymphocytes. Enzyme-linked immunosorbent assay （ELISA） was used to determine the levels of IL-2 and TNF-<italic>α</italic>. Result:<italic>L. meyenii </italic>extracts Fr₃ and Fr₆， and monomers <italic>N</italic>-benzyl hexadecanamide and 1，2-dihydro-4-carboxaldehyde-3-benzyl-<italic>N</italic>-hydroxypyridine slightly promoted the proliferation of Con A-induced T lymphocytes and LPS-induced B lymphocytes （<italic>P</italic><0.01） as compared with the conditions in the model group. <italic>L. meyenii</italic> extracts and monomers significantly induced the secretion of IL-2 and TNF-<italic>α</italic> by splenic lymphocytes （<italic>P</italic><0.01）. Conclusion:<italic>L. meyenii</italic> extracts and monomers can achieve immunological enhancement by promoting the secretion of IL-2 and TNF-<italic>α</italic>， and facilitate the proliferation of splenic lymphocytes. The active components are presumedly macamides and pyridine alkaloids， and the specific mechanism still needs to be further explored.

Cholesterol-associated lysosomal disorder triggers cell death of hematological malignancy: Dynamic analysis on cytotoxic effects of LW-218

The integrity of lysosomes is of vital importance to survival of tumor cells. We demonstrated that LW-218, a synthetic flavonoid, induced rapid lysosomal enlargement accompanied with lysosomal membrane permeabilization in hematological malignancy. LW-218-induced lysosomal damage and lysosome-dependent cell death were mediated by cathepsin D, as the lysosomal damage and cell apoptosis could be suppressed by depletion of cathepsin D or lysosome alkalization agents, which can alter the activity of cathepsins. Lysophagy, was initiated for cell self-rescue after LW-218 treatment and correlated with calcium release and nuclei translocation of transcription factor EB. LW-218 treatment enhanced the expression of autophagy-related genes which could be inhibited by intracellular calcium chelator. Sustained exposure to LW-218 exhausted the lysosomal capacity so as to repress the normal autophagy. LW-218-induced enlargement and damage of lysosomes were triggered by abnormal cholesterol deposition on lysosome membrane which caused by interaction between LW-218 and NPC intracellular cholesterol transporter 1. Moreover, LW-218 inhibited the leukemia cell growth

Protection of inflammatory osteoblasts in neonatal rats using catalpol from the root of rehmannia glutinosa / 中国组织工程研究

BACKGROUND: Studies have shown that abnormal osteoblast metabolism may cause abnormal subchondral bone mineralization in knee osteoarthritis. OBJECTIVE: To verify the effects of catalpol from the root of Rehmannia glutinosa on osteoblast proliferation and drug toxicity, and the anti-inflammatory protective effect on inflammatory osteoblasts induced by lipopolysaccharide. METHODS: (1) Osteoblasts from newborn Sprague-Dawley rats were primarily extracted, cultured, and passaged. The activity and proliferation of osteoblasts were determined by observing the morphology of osteoblasts alkaline phosphatase staining and staining of mineralized nodules. (2) Cell counting kit-8 (CCK-8) method was used to observe the effect of different concentrations of catalpol from the root of Rehmannia glutinosa on osteoblast activity. (3) Different concentrations of lipopolysaccharide (0, 10, 20, 40, 80, 160 mg/L) were used to induce inflammatory osteoblasts in fetal rats. CCK-8 method was used to verify the best concentration. (4) The experiment was divided into three groups: blank group, model group, low-, medium- and high-concentration catalpol groups. Inflammatory osteoblasts were induced by lipopolysaccharide at 80 mg/L, and then treated for 8 hours. CCK-8 method was used to observe the effect of different concentrations of catalpol on inflammatory osteoblasts. The study protocol was approved by the Medical Ethics Committee of Liuhe District People’s Hospital in Nanjing. RESULTS AND CONCLUSION: When osteoblasts were cultured to the fourth generation, followed by alkaline phosphatase staining, black grey granules were found in the cytoplasm of the positive cells, and the morphology of the cells was irregular. When the concentration of catalpol was lower than 1 mg/L, it had no significant effect on osteoblasts; when it was higher than 10 mg/L, it had a significant effect on the proliferation of osteoblasts but no drug toxicity (P < 0.05). When the concentration of lipopolysaccharide was higher than 80 mg/L, there was a significant trend of inflammatory damage to osteoblasts (P < 0.01). Therefore, 80 mg/L was selected as the best injury concentration in this experiment. When the concentration of catalpol from the root of Rehmannia glutinosa was lower than 1 mg/L, it had no significant protective effect on the inflammatory response of osteoblasts (P < 0.05); when it was higher than 10 mg/L, it had significant protective effect on the inflammatory response of osteoblasts (P < 0.05). Therefore, when the concentration of catalpol from the root of Rehmannia glutinosa reaches a certain level, it has no toxic effect on osteoblasts, promotes proliferation, and has anti-inflammatory protective effect on inflammatory osteoblasts induced by lipopolysaccharide.

A homogenous nanoporous pulmonary drug delivery system based on metal-organic frameworks with fine aerosolization performance and good compatibility

Pulmonary drug delivery has attracted increasing attention in biomedicine, and porous particles can effectively enhance the aerosolization performance and bioavailability of drugs. However, the existing methods for preparing porous particles using porogens have several drawbacks, such as the inhomogeneous and uncontrollable pores, drug leakage, and high risk of fragmentation. In this study, a series of cyclodextrin-based metal-organic framework (CD-MOF) particles containing homogenous nanopores were delicately engineered without porogens. Compared with commercial inhalation carrier, CD-MOF showed excellent aerosolization performance because of the homogenous nanoporous structure. The great biocompatibility of CD-MOF in pulmonary delivery was also confirmed by a series of experiments, including cytotoxicity assay, hemolysis ratio test, lung function evaluation,

Evodiamine-inspired dual inhibitors of histone deacetylase 1 (HDAC1) and topoisomerase 2 (TOP2) with potent antitumor activity

A great challenge in multi-targeting drug discovery is to identify drug-like lead compounds with therapeutic advantages over single target inhibitors and drug combinations. Inspired by our previous efforts in designing antitumor evodiamine derivatives, herein selective histone deacetylase 1 (HDAC1) and topoisomerase 2 (TOP2) dual inhibitors were successfully identified, which showed potent and antitumor potency. Particularly, compound was orally active and possessed excellent antitumor activity in the HCT116 xenograft model (TGI = 75.2%, 150 mg/kg, .) without significant toxicity, which was more potent than HDAC inhibitor vorinostat, TOP inhibitor evodiamine and their combination. Taken together, this study highlights the therapeutic advantages of evodiamine-based HDAC1/TOP2 dual inhibitors and provides valuable leads for the development of novel multi-targeting antitumor agents.

Miltirone induces cell death in hepatocellular carcinoma cell through GSDME-dependent pyroptosis

Pyroptosis is a form of programmed cell death, and recently described as a new molecular mechanism of chemotherapy drugs in the treatment of tumors. Miltirone, a derivative of phenanthrene-quinone isolated from the root of Bunge, has been shown to possess anti-cancer activities. Here, we found that miltirone inhibited the cell viability of either HepG2 or Hepa1-6 cells, and induced the proteolytic cleavage of gasdermin E (GSDME) in each hepatocellular carcinoma (HCC) cell line, with concomitant cleavage of caspase 3. Knocking out switched miltirone-induced cell death from pyroptosis to apoptosis. Additionally, the induction effects of miltirone on GSDME-dependent pyroptosis were attenuated by siRNA-mediated caspase three silencing and the specific caspase three inhibitor Z-DEVD-FMK, respectively. Miltirone effectively elicited intracellular accumulation of reactive oxygen species (ROS), and suppressed phosphorylation of mitogen-activated and extracellular signal-regulated kinase (MEK) and extracellular regulated protein kinases 1/2 (ERK1/2) for pyroptosis induction. Moreover, miltirone significantly inhibited tumor growth and induced pyroptosis in the Hepa1-6 mouse HCC syngeneic model. These results provide a new insight that miltirone is a potential therapeutic agent for the treatment of HCC GSDME-dependent pyroptosis.

Performance Evaluation of Body Fluid Cellular Analysis Using the Beckman Coulter UniCel DxH 800, Sysmex XN-350, and UF-5000 Automated Cellular Analyzers

BACKGROUND: Automated cellular analyzers are expected to improve the analytical performance in body fluid (BF) analysis. We evaluated the analytical performance of three automated cellular analyzers and established optimum reflex analysis guidelines. METHODS: A total of 542 BF samples (88 cerebrospinal fluid [CSF] samples and 454 non-CSF samples) were examined using manual counting and three automated cellular analyzers: UniCel DxH 800 (Beckman Coulter), XN-350 (Sysmex), and UF-5000 (Sysmex). Additionally, 2,779 BF analysis results were retrospectively reviewed. For malignant cell analysis, the receiver operating characteristic (ROC) curve was used, and the detection of high fluorescence-BF cells (HF-BFs) using the XN-350 analyzer was compared with cytology results. RESULTS: All three analyzers showed good agreement for total nucleated cell (TNC) and red blood cell (RBC) counts, except for the RBC count in CSF samples using the UniCel DxH 800. However, variable degrees of differences were observed during differential cell counting. For malignant cell analysis, the area under the curve was 0.63 for the XN-350 analyzer and 0.76 for manual counting. We established our own reflex analysis guidelines as follows: HF-BFs 83.4/100 WBCs or eosinophils >3.8% are the criteria for mandatory double check confirmation with 1,000× magnification examination. CONCLUSIONS: The three automated analyzers showed good analytical performances. Application of reflex analysis guidelines is recommended for eosinophils and HF-BFs, and manual confirmation is warranted.

Evaluation effects of four cytotoxicity methods on in vitro inhibition of shikonin against tumor cells / 中草药

Objective To study the effects of four cytotoxicity evaluation methods on the inhibition rate of shikonin (SK) in vitro, and to compare the pseudo-negative phenomenon often found in the evaluation of cytotoxic activity of natural pigments represented by naphthoquinones in Lithospermum erythrorhizon. Methods SK was co-cultured with its high-sensitive strain HL-60 cells and low-sensitivity strain A549 cells, trypan blue method, sulforhodamine B (SRB) method, Cell Counting Kit-8 (CCK-8) and MTT cytotoxicity test were used for parallel experiments to determine the dose-effect relationship curve of SK (0.4-128 μmol/L) inhibiting the growth of cells. Results The half-inhibitory concentration (IC50) of shikonin on HL-60 cells was determined by trypan blue method, SRB method, CCK-8 method, and MTT method, which was 0.57, 0.77, 1.36, and 1.01 μmol/L, respectively. For A549 cells, the IC50 was 6.30, 10.38, 13.48, and 15.24 μmol/L, respectively. When the concentration of shikonin was below 3.2 μmol/L and 32 μmol/L, the inhibition rate of the two kinds of cells increased linearly by the four methods, followed by differences. Among them, the results of the trypan blue method and the SRB method are in good agreement, while the MTT method and the CCK-8 method have lower inhibition rates. At 12.8 μmol/L, the inhibitory rate of SK on HL-60 cell measured by CCK-8 was 81%, while the inhibitory rate measured by trypan blue method was 96%, and at 128 μmol/L the inhibitory rate of SK on A549 cells measured by MTT method was 89%, however, the inhibitory rate measured by trypan blue method was 99%. The absorption spectrum of SK overlapped with formazan at the wavelength from 400 to 600 nm, with the maximum overlap peak from 550 to 570 nm, and CCK-8 reagent had a synergistic inhibitory effect on HL-60 with SK. The results of trypan blue method showed that SK at the highest dose almost completely killed cells in the plate wells, which was significantly different from the control group, but both MTT method and CCK-8 method resulted in a pseudo-negative phenomenon. Conclusion Therefore, cytotoxicity test of natural pigments represented by naphthoquinones in L. erythrorhizon, MTT method, and CCK-8 method are not recommended, while SRB method and trypan blue method are suggested.

Establishment of human ApoE4 gene transfected PC12 cell line and the effect of maltol aluminum on its cell viability / 中国职业医学

OBJECTIVE: To establish a PC12 cell line with stable expression of human apolipoprotein E( ApoE4) gene by transfection with a lentiviral vector carrying human ApoE4 gene and to investigate the effect of maltol aluminum on the viability of transfected PC12 cells. METHODS: The lentiviral vector carrying human ApoE4 gene was transfected into PC12 cells. PC12 cells with overexpression of ApoE4 gene and negative control vector were obtained after puromycin screening.The mRNA relative expression of R-Apo E and( or) H-Apo E-FLAG of cells in PC12,PC12-NC and PC12-ApoE4 groups were detected by real-time fluorescent quantitative polymerase chain reaction,and the effect of cell construction was identified. PC12-ApoE4 cells and PC12 cells were exposed to maltol aluminum solution at concentrations of 0. 00,100. 00,200. 00 and 400. 00 μmol/L respectively for 24 hours,and cell viability was detected by Cell Counting Kit-8( CCK-8)assay. RESULTS: PC12-ApoE4 and PC12-NC cells under the fluorescence microscope showed fluorescence expression,suggesting that transfection was successful. The expression of PC12 cells showed no fluorescence. The relative expression of H-Apo E-FLAG gene mRNA( the median amount) of PC12-ApoE4 cells was 148. 74,which was higher than the R-Apo E gene in PC12 cells( 1. 00) and PC12-NC cells( 1. 01)( P < 0. 01). After exposure to maltol aluminum,the cell survival rates in terms of the main effect and interaction effect of dose and cell type were statistically significant( P < 0. 01),among them,the cell viabilities were decreased in the concentration range of 0. 00-400. 00 μmol/L with the dose of maltol aluminum exposure increased,showing dose-effect relationship( P < 0. 01). CONCLUSION: The cell line stably expressed human ApoE4 gene was constructed successfully. There was interaction between the effects of maltol aluminum and ApoE4 gene on the survival rate of PC12 cells,and ApoE4 gene could enhance the cytotoxicity of maltol aluminum on PC12 cells.

Exosomes as therapeutic drug carriers and delivery vehicles across biological membranes: current perspectives and future challenges

Exosomes are small intracellular membrane-based vesicles with different compositions that are involved in several biological and pathological processes. The exploitation of exosomes as drug delivery vehicles offers important advantages compared to other nanoparticulate drug delivery systems such as liposomes and polymeric nanoparticles; exosomes are non-immunogenic in nature due to similar composition as body׳s own cells. In this article, the origin and structure of exosomes as well as their biological functions are outlined. We will then focus on specific applications of exosomes as drug delivery systems in pharmaceutical drug development. An overview of the advantages and challenges faced when using exosomes as a pharmaceutical drug delivery vehicles will also be discussed.

Study on cell counting random error of the practical McAb-A-E direct method for cell sheet of T lymphocyte subsets / 国际检验医学杂志

Objective To research and evaluate cell counting random error for cell sheet of T lymphocyte subsets in the practical McAb‐A‐E direct method ,and old method of McAb‐A‐E direct method compared .Methods Randomly selected 20 specimens ,cell sheet of T lymphocyte subsets on counting 200 cell at least 2 area from 2/6~4/6 area ,counting area non‐repeated ,CD4+ and CD8+continuous counter 4 times ,CD3+ continuous counter 2 times .Results In the practical McAb‐A‐E direct method ,random error mean of cell counting was separately CD3+ :7 .86 ,CD4+ :9 .99 ,CD8+ :8 .55 ,CD4+ /CD8+ :0 .33 ,lower than old method of McAb‐A‐E direct method ,that was CD3+ :15 .00 ,CD4+ :13 .80 ,CD8+ :10 .70 ,CD4+ /CD8+ :0 .69 .Conclusion Cell counting random error in practical McAb‐A‐E direct method for cell sheet of T lymphocyte subsets is less than old method of McAb‐A‐E direct method .

The antitumor effect of tanshinone IIA on anti-proliferation and decreasing VEGF/VEGFR2 expression on the human non-small cell lung cancer A549 cell line

The effects of tanshinone IIA on the proliferation of the human non-small cell lung cancer cell line A549 and its possible mechanism on the VEGF/VEGFR signal pathway were investigated. The exploration of the interaction between tanshinone IIA and its target proteins provides a feasible platform for studying the anticancer mechanism of active components of herbs. The CCK-8 assay was used to evaluate the proliferative activity of A549 cells treated with tanshinone IIA (2.5-80 μmol/L) for 24, 48 and 72 h, respectively. Flow cytometry was used for the detection of cell apoptosis and cell cycle perturbation. VEGF and VEGFR2 expression were studied by Western blotting. The binding mode of tanshinone IIA within the crystal structure of the VEGFR2 protein was evaluated with molecular docking analysis by use of the CDOCKER algorithm in Discovery Studio 2.1. The CCK-8 results showed that tanshinone IIA can significantly inhibit A549 cell proliferation in a dose- and time-dependent manner. Flow cytometry results showed that the apoptosis rate of tested group was higher than the vehicle control, and tanshinone IIA-treated cells accumulated at the S phase, which was higher than the vehicle control. Furthermore, the expression of VEGF and VEGFR2 was decreased in Western blot. Finally, molecular docking analysis revealed that tanshinone IIA could be stably docked into the kinase domain of VEGFR2 protein with its unique modes to form H-bonds with Cys917 and π-π stacking interactions with Val848. In conclusion, tanshinone IIA may suppress A549 proliferation, induce apoptosis and cell cycle arrest at the S phase. This drug may suppress angiogenesis by targeting the protein kinase domains of VEGF/VEGFR2.

Comparison of the karyote detection results of automatic blood analyzer and manual method in special body fluids / 国际检验医学杂志

Objective To compare the karyote counting and classification results of Sysmex XE-5000 automatic blood analyzer (XE-5000) and manual method in special body fluids .Methods 100 cases of special body fluid specimens (including cerebrospinal fluid and serous cavity effusion) were analyzed ,and the the karyote counting and classification were respectively detected by XE-5000 and the traditional manual method of microscope .Results When the karyote counts were 31-1 000/μL ,there was no signifi-cant difference between XE-5000 and manual method (P>0 .05) .And the karyote counting and classification results of XE-5000 correlated with those of manual method (r=0 .981 ,0 .991 ,P<0 .05) .Conclusion When the karyote counts are 31-1 000/μL ,XE-5000 has good accuracy and high precision in karyote detection in special body fluids .

Application of Cell Counting Kit-8 in detecting the growth inhibiting effect of 5-Aza-2 ’-deoxycytidine on chronic myeloid leukemia cells / 解剖学报

Objective To study the application of Cell Counting Kit-8(CCK-8) in detecting the growth inhibiting effect of 5-Aza-2’-deoxycytidine on chronic myeloid leukemia cell .Methods The proliferation of K562 cells was detected by CCK-8 with different concentrations of 5-Aza-2 ’-deoxycytidine and the cell cycle and apoptosis of K 562 cells were detected after K562 treated by 50% inhibitory concentration of 5-Aza-2 ’-deoxycytidine .Results The 50% inhibitory concentration of 5-Aza-2’-deoxycytidine was 15.55nmol/L, after treated with this concentration , K562 cells showed that G2 phase arrest occurred , proliferation inhibited and apoptosis peaks appeared .Conclusion Inhibition of proliferation of K562 cells with different concentrations of 5-Aza-2’-deoxycytidine varied in a dose-dependent relationship , and 5-Aza-2’-deoxycytidine could promote apoptosis of K 562 cells.CCK-8 can be used in detecting the effect of 5-Aza-2’-deoxycytidine on chronic myeloid leukemia cells .

Comparison of viability of oral epithelial cells stored by different freezing methods / 대한치과보존학회지

This study examined the influence of the storage methods on the viability of oral epithelial cells using conventional cell freezing storage, slow freezing preservation, rapid freezing preservation, and slow freezing preservation with a pressure of 2 Mpa or 3 Mpa. The cell viability was evaluated by cell counting, WST-1 and the clonogenic capacity after 6 days of freezing storage. After 6 days, the frozen cells were thawed rapidly, and the cell counting, WST-1, and clonogenic capacity values were measured and compared. 1. The results from cell counting demonstrated that conventional cryopreservation, slow freezing under a 2 Mpa pressure and slow freezing under a 3 Mpa pressure showed significantly higher values than slow freezing preservation and rapid freezing preservation (p<0.05). 2. The results from the optical density by WST-1 demonstrated that slow freezing under a 2 Mpa pressure showed significantly higher values than slow freezing preservation and rapid freezing preservation (p<0.05). 3. The clonogenic capacity demonstrated that slow freezing under a 2 Mpa pressure showed significantly higher values than slow freezing preservation and rapid freezing preservation (p<0.05).

STUDIES ON A NEW METHOD FOR COUNTING LIVING BACTERIAL CELL NUMBER / 微生物学通报

MTT Colorimetric method is usually applied for measuring the living animal cell number. By changing the reaction temperature and the reaction time as well as the colorimetric wavelength, the improved MTT colorimetric method was established to count the living bacterial cell number. This new method was used to measure the living cell concentration in the process for culturing bacteria PBW1. The results measured by the improved MIT colorimetric method and dilute plate method are similar. Compared with other methods including the dilute plate method, the improved MTT colorimetric method has many advantages such as accuracy, quickness.