A chemical-ecology approach has been used to screen plants growing in Guyana Highlands as an indicator of production of biologically active secondary metabolites. Extracts of leaves from 19 species, most of them endemic in this area, and collected at the top of Roraima Tepui (2,723 m) were screened in vitro at different concentrations for their potential cytotoxic activity against three tumour cell lines: HT29 (colon), A549 (lung) and MDA-MB-231 (breast). MTT (tetrazolium blue) colorimetric assay was employed as cytotoxicity test. Extracts of nine species caused less than 30% growth in at least one cell line. From these species, high cytotoxic activity was detected in Casearia sylvestris var. lingua and Ledotamnus sessiliflorus extracts; medium activity was found in Cyathea sp. Two other species, Cyrilla racemiflora and Heliamphora minor showed lower but significant cytotoxicity. Further cytotoxicity-directed fractionation of these extracts would be advisable to isolate and identify the active principles of these plants.
Cytotoxicity ; Aspects of disease screening ; Cell Line ; MB-2 ; Employed

When some testing institutions performed biological evaluation to the disposable medical syringe piston, cytotoxicity was found. According to the biological evaluation testing Selection Guide proposed by Ministry of Health and the Comments of Sample Provider, We performed biological evaluation to one sample by using 5 tests of basic biological evaluation. Cytotoxicity was found, which was probably caused by the residue of the lotion. This research provides reference for objective evaluation of disposable medical syringe piston and safe guarantee of the product.
Cytotoxicity Tests, Immunologic ; Disposable Equipment ; Syringes ; adverse effects

The cytotoxicity of medical ultrasonic couplant was tested by MTT assay and agar overlay test. By MTT assay, when the inoculum density was high, the cytotoxicity level was low, or vice versa. The cytotoxicity grade tested by agar overlay was not accord to MTT assay's too. MTT assay is suitable to test the cytotoxicity of medical ultrasonic couplant because it is quantitative and more sensitive, however, the experimental condition and the preparative method of extraction should be determined.
Animals ; Cell Line ; Colorimetry ; Cytotoxicity Tests, Immunologic ; methods ; Mice ; Ultrasonics

OBJECTIVETo assess the immunotoxicologic effects of genetically modified drought resistant wheat T349 with GmDREB1 gene.

METHODSA total of 250 female BALB/c mice (6-8 week-old, weight 18-22 g) were divided into five large groups (50 mice for each large group) by body weight randomly. In each large group, the mice were divided into five groups (10 mice for each group) by body weight randomly, which were set as negative control group, common wheat group, parental wheat group, genetically modified wheat group and cyclophosphamide positive control group, respectively. Mice in negative control and positive control group were fed with feedstuff AIN-93G, mice in common wheat group, non-genetically modified parental wheat group and genetically modified wheat group were fed with feedstuffs added corresponding wheat (proportion up to 76%) for 30 days, then body weight, organ coefficient of spleen and thymus, peripheral blood lymphocytes phenotyping, serum cytokine, serum immunoglobulin, antibody plaque-forming cell (PFC), serum 50% hemolytic value (HC50), mitogen-induced splenocyte proliferation, delayed-type hypersensitivity (DTH) reaction and phagocytic activities of phagocytes were detected respectively.

RESULTSAfter 30 days raise, among negative control group, common wheat group, non-genetically modified parental wheat group, genetically modified wheat group and cyclophosphamide positive control group, mice body weight were (21.0±0.3), (20.4±0.7), (21.1±1.0), (21.1±1.0), (19.4±1.0) g, respectively (F=7.47, P<0.01); organ coefficient of spleen were (0.407±0.047)%, (0.390±0.028)%, (0.402±0.042)%, (0.421±0.041)%, (0.304±0.048)%, respectively (F=12.41, P<0.01); organ coefficient of thymus were (0.234±0.032)%, (0.246±0.028)%, (0.249±0.040)%, (0.234±0.034)%, (0.185±0.039)%, respectively (F=5.58, P<0.01); the percentage of T cell in peripheral blood were (70.43±4.44)%, (68.33±5.37)%, (73.04±2.68)%, (74.42±2.86)%, (90.42±1.66)%, respectively (F=57.51, P<0.01); the percentage of B cell were (13.89±3.19)%, (15.34±4.84)%, (13.06±4.22)%, (12.93±2.36)%, (3.01±0.96)%, respectively (F=12.79, P<0.01); the percentage of Th cell were (55.87±3.80)%, (55.24±4.60)%, (57.92±3.70)%, (59.57±2.54)%, (77.37±2.31)%, respectively (F=68.58, P<0.01);the Th/Ts ratio were 4.16±0.29, 4.73±0.96, 4.19±0.78, 4.52±0.40, 6.34±0.73, respectively (F=17.57, P<0.01);the serum IgG were (1046.38±210.67), (1065.49±297.22), (1517.73±299.52), (1576.67±241.92), (1155.88±167.05) µg/ml, respectively (F=10.53, P<0.01); the serum IgM were (333.83±18.97), (327.73±27.72), (367.47±27.18), (363.42±46.14), (278.71±24.42) µg/ml, respectively (F=12.11, P<0.01); the serum IgA were (51.69±10.10), (42.40 ± 8.35), (32.11±4.22), (37.12±4.90), (41.45±8.89) µg/ml, respectively (F=8.25, P<0.01); the PFC were (29.2±14.6), (28.0±20.0), (34.8±30.9), (33.2±25.1), (4.8±5.3) per 10(6) splenocyte, respectively (F=3.33, P<0.05); the HC50 were 82.3±6.5, 79.7±4.6, 75.8±4.1, 74.9±3.6, 70.8±2.1, respectively (F=9.99, P<0.01);the LPS-induced splenocyte proliferation were 0.21±0.10, 0.21±0.14, 0.26±0.12, 0.25±0.14, 0.07±0.06, respectively (F=4.18, P<0.05).

CONCLUSIONThe genetically modified drought-resistant wheat T349 was substantially equivalent to parental wheat in the effects on immune organs and immunologic functions of mice, and it didn't show immunotoxicity.

Animals ; Cytotoxicity Tests, Immunologic ; Cytotoxicity, Immunologic ; Droughts ; Female ; Mice ; Mice, Inbred BALB C ; Plants, Genetically Modified ; immunology ; toxicity ; Triticum ; genetics ; immunology ; toxicity

In a previous report, it was felt that the rat tumor cell line, T-333, was a mixture of heterogeneous cells with different characteristics with respect to karyotype, tumorigenicity, and response to Rolls Sarcoma virus (RSV) infection. These characteristics of hetero-geneous cell subpopulations could be selected by use of different culture substrates. In this experiment, diversity of the cells in response to complement mediated cytolysis employing syngeneic rat anti-sera was studied. More than 50% of the glass grown cells were lysed while only 19% of the plastic grown cells were lysed by the specific immune sera of syngeneic rats. This finding suggests that growth in plastic culture wares selects cells with resistance to complement mediated cytolysis. It seems likely that the previously reported enhanced tumorigenicity of plastic grown T-333 cells is due to clonal selection of cell subpopulations which can better tolerate at least one arm of the in vivo immune surveillance system.
Animal ; Cells, Cultured ; Cytotoxicity, Immunologic ; Neoplasms, Experimental/immunology* ; Plastics ; Rats ; Rats, Inbred Strains

PURPOSE: During differentiation of HL-60 cells by all-trans retinoic acid(ATRA), we analyzed the expression of Fcr receptors and Mac-1 by molecules of equivalent soluble fluorochromes(MESF) and functional studies. METHODS: HL-60 cells were induced to differentiate by adding 1micrometer ATRA. On the 4th and 7th day after stimulation as well as before stimulation, the cells were analyzed for phenotypic and functional differentiation. Phenotypic analysis was performed by flow cytometry after staining the cells with PE-conjugated anti-human CD64(FcrRI), CD32(FcrRII), CD16(FcrRIII), CD11b, CD18. The measured fluorescent intensity was transformed into MESF. Phagocytic activity was measured by flow cytometry after incubation of the cells with fluorochrome-conjugated beads. Respiratory burst was measured by chemiluminescence assay. ADCC was measured by hemoglobin release assay. Opsonophagocytic activity was measured by fungicidal assay. Correlation between MESF of FcrR and Mac-1 and function of HL-60 was measured. RESULTS: Percent positive cells and MESF of CD11b and FcrRI increased on the 4th day and decreased on the 7th day. Percent positive cells of CD18 was 99% regardless of differentiation. But MESF of CD18 was increased on the 4th day and decreased on the 7th day. Percent positive cells of FcrRII were above 90% regardless of differentiation. MESF of FcrRII showed no significant change. FcrRIII expression was not induced. Phagocytic activity of HL-60 cells was increased twofold. Chemiluminescence of HL-60 cells was increased up to 60-fold on the 7th day. ADCC of HL-60 cells was incerased up to 2.5-fold on the 7th day. Opsonophagocytic activity increased twice on the 4th day. ADCC and opsonophagocytic activity correlates with the expression of CD11b/CD18 and FcrRII. CONCLUSION: Differentiation of HL-60 cells with ATRA induces several functional maturations until 7 days with expression of FcrR and Mac-1.
Antibody-Dependent Cell Cytotoxicity ; Flow Cytometry ; HL-60 Cells* ; Humans ; Luminescence ; Respiratory Burst ; Tretinoin*

OBJECTIVE: To investigate the injury effect of anti-donor specific antibody (DSA) on human umbilical vein enolothelial cells (HUVEC) in NK-mediated antibody-dependent cell cytotoxity (ADCC). METHODS: The peripheral blood of 10 healthy donors was colleced for allo-HSCT of AML patients diagnosed in Department of Hemology of the Tumor Hospital affiliated to Shanxi Medical University, then the peripheral blood NK cells were isolated and used as the effector cells; the HUVEC of passages 9-6 were selected and co-cultured with DSA, then the DSA-binding HUVEC were used as the target cells (CDH group), while the DSA-unbinding HUVEC were used as negative control (UDH group). After co-culture of effecor cells with target cells, the expression of IFN-γ was detected by flow cytometry and the HUVEC activity was detected by using MTT method, so as to indirectily reflect the injury effect of DSA-mediated ADCC on endothelial cells. RESULTS: With the increase of effector-target (E:T) ratio, the activity of HUVEC decreased, the expression level of IFN-γ increased. Under the some effector-target ratio (1∶1, 10∶1, 20∶1), the activity of HUVEC in CDH group was significantly lower than that of UDH group, and the expression of IFN-γ was significantly higher than that of the UDH group (P<0.05). CONCLUSION DSA can damage vascular endothelial cells through the ADCC effect mediated by NK cells.
Antibodies, Monoclonal ; Antibody-Dependent Cell Cytotoxicity ; Endothelial Cells ; Flow Cytometry ; Humans ; Killer Cells, Natural

OBJECTIVETo establish a novel method for ex vivo expansion of natural killer cells from human umbilical blood, so as to provide the basis for NK cell therapy.

METHODSMononucleated cells from human umbilical blood were harvested and suspended in a serum-free medium containing 5% autologous plasma, recombinant human IL-15 (50 ng/ml) and hydrocortisone sodium succinate (5×10 mol/L) at a concentration of 1.5×10/ml, then the cells were seeded into flasks pre-coated with heparin sodium (100 U/cm) or/and anti-human CD16 antibody (1 µg/cm). After culture for 2 weeks, the cells were harvested and counted. Ratios of CD3/CD56 of the cells were determined by flow cytometry. MTT test was performed to assess the cytotoxicity against K562 cells with graded ratios of effector/target cells.

RESULTSIn contrast to the cells in flasks without pre-coating, the attached colonies appeared predominantly within 1 week of culture from heparin- and antibody-coated groups. The cell numbers from the pre-coated groups were significantly higher than that of uncoated one after culture for 2 weeks. Furthermore, the ratios of CD3/CD56 cells were much higher in pre-coated groups, and that of the cells from flasks pre-coated with heparin and antibody were the highest (all the P values <0.01). MTT test showed that the cytotoxic activity of the cells stimulated by precoating were much more potent than that of the cells without the stimulation.

CONCLUSIONAdvantageous expansion of NK cells can be achieved by precoating with heparin and anti-CD16 antibody, and also by supplement with IL-15 and hydrocortisone into the media, so the umbilical NK cells with high purity and potent cytotoxicity can be obtained.

CD56 Antigen ; Cells, Cultured ; Cytotoxicity, Immunologic ; Fetal Blood ; Heparin ; Humans ; Killer Cells, Natural

BACKGROUND: Zinc which is widely used to treat Behcet's disease, is known to be an important modulator in various aspects of immunity including cell mediated immunity (CMI). CMI is suspected of playing a major role in the pathogenesis of Behçet's disease. OBJECTIVE: This study was done to clarify the relationship of CMI and zinc in Behçet's disease. METHODS: Serum zinc level, NK cell activity, and ADCC were measured in 83 patients with Behçet's diseade. The results were analyzed using multiple regression analysis. RESULTS: ADCC and serum zinc level were found to be two significant variables that affect NK cell activity positively and negatively, respectively. CONCLUSION: Serum zinc is presumed to exert inhibitory effect on NK cell activity but does not affect ADCC in Behçet's disease patients.
Antibody-Dependent Cell Cytotoxicity ; Humans ; Immunity, Cellular ; Killer Cells, Natural ; Zinc*

BACKGROUND: Routine typing for HLA-B27 has been usually accomplished by the microcytotoxicity assay in Korea because it does not require special equipment and is easily reproducible. Recently, an immunofluorescence method and the polymerase chain reaction have also been applied for HLA-B27 testing. However, the current economic crisis in Korea have led domestic manufacturers to develop a Korean HLA-B27 typing kit. The aim of this study was to assess the advantages and disadvantages of this kit and to assess the possibility of replacing the currently used foreign-made kits with this domestic one. METHODS: HLA-B27 testing by the microcytotoxicity test was performed on 116 patients during a period of 3 months in 1998. The Biotest typing tray and the Chongkundang typing tray were tested simultaneously. Results: There was no difference in results in 116 samples (positive: 39, negative: 77). The Korean typing tray showed high false positivity of the negative control well (8 point: 1 case, 6 point: 33 cases, 4 point: 47 cases, 2 point: 17 cases, 1 point: 18 cases) and 6 of the HLA-B27 negative cases showed false positivity in one of the four HLA-B27 wells. Typing of HLA-Bw4 and Bw6 revealed an inconsistency in five and six cases, respectively. CONCLUSIONS: Despite of the false positivity of the negative control in Korean panel, we believe that Korean typing tray can replace the foreign-made tray due to its low cost and adequate performance. Because placenta of Korean multiparous women was used for the kit, Chongkundang typing tray seems to correlate better with Korean HLA-B27 subtypes.
Cytotoxicity Tests, Immunologic ; Female ; Fluorescent Antibody Technique ; HLA-B27 Antigen* ; Humans ; Korea ; Placenta ; Polymerase Chain Reaction