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[Conditions of contrast ultrasound that affect the proliferation of rat smooth muscle cells].

OBJECTIVE: To investigate the effect of an echo-contrast agent on the proliferation of rat smooth muscle cells under different ultrasound conditions. METHODS: The vascular smooth muscle cells of rats were cultured with echo-contrast agent in 96-well plates, followed by exposure to ultrasound of different conditions. Trypan blue staining was performed 48 h later, and the proliferation of the cells observed by MTT assay. RESULTS: No cytotoxicity was found by trypan blue staining when the mechanical index of ultrasound was below 0.75. Compared with the control cells, the proliferation of the smooth muscle cells was decreased following the exposure as the mechanical index of ultrasound increased. The most obvious inhibition of cell proliferation was resulted when the microbubble concentration was 20% for a 60-second exposure. CONCLUSIONS: The inhibition of the vascular smooth muscle cell proliferation by echo-contrast agent destruction is correlated with the mechanical index of the ultrasound, concentration of the echo-contrast agent, and exposure time of ultrasound.

Animals↗

Cytotoxic effects of soluble factor in preeclamptic sera on human trophoblasts.

Evidence indicating abnormal biological behavior of trophoblasts has been seen in preeclamptic patients, but the mechanism is still unknown. We have previously shown that endothelial injury and neutrophil activation are induced by certain factors in preeclamptic sera. We investigated the effect of sera from eight preeclamptic and 11 normal pregnant women on cellular proliferation and viability of trophoblasts using 3H-thymidine incorporation and the trypan-blue dye exclusion test, respectively. Five of eight preeclamptic sera, but none of the normal pregnant sera, inhibited 3H-thymidine incorporation. The trypan-blue test revealed the sera reduced cellular viability. Gel permeation showed that the greatest growth-inhibitory activity corresponded to a molecular weight of 50 kDa. The serum-mixing test revealed this permeation and inhibitory preeclamptic sera suppressed the growth-promoting activity of normal pregnant sera in a dose-dependent manner. These results suggested the presence of certain factors in some preeclamptic sera that can affect cellular behavior of human trophoblasts.

Adult↗

Effect of gamma interferon on phospholipid hydrolysis and fatty acid incorporation in L929 cells infected with Rickettsia prowazekii.

Treatment of Rickettsia prowazekii-infected L929 cells with gamma interferon (IFN-gamma) immediately after infection altered the lipid metabolism of the host cells as determined by measurement of phospholipid hydrolysis and oleic acid incorporation into phospholipids and neutral lipids. At 48 h postinfection, there was increased phospholipid hydrolysis in infected cultures relative to mock-infected cultures and a further increase in radiolabeled phospholipid hydrolysis in IFN-gamma-treated infected cultures. Oleic acid, the radiolabeled product of hydrolysis, was found in both the free fatty acid and neutral lipid fractions. None of the mock-infected cultures demonstrated increased hydrolysis of their radiolabeled phospholipids in response to treatment with IFN-gamma. Most of the radiolabeled oleic acid incorporated into cultures in the interval between 24 and 48 h after infection and IFN-gamma treatment was present in the phospholipid fraction. However, the neutral lipid fraction from the infected cultures that had been IFN-gamma treated was labeled to a greater extent than that from the untreated cultures. Thin-layer chromatographic analysis of the neutral lipid fractions from both the hydrolysis and incorporation experiments demonstrated that most of the radiolabel was in triglycerides. The infected cultures at 30 h were intact as assessed by the exclusion of trypan blue, but at 48 h postinfection in the IFN-gamma-treated infected cultures more than half of the cells were unable to exclude trypan blue. In no case did the mock-infected cells show substantial damage as a result of IFN-gamma treatment.

Animals↗

The effects of electrolyte, lactate, high-concentrated glucose, and dialysate on peritoneal mesothelial cells.

In order to investigate which component of dialysate is responsible for mesothelial cell damage, we studied the chronic cytotoxicity to mesothelial cells by using four types of solution. Four different types of solution (Ringer's solution, lactate, high-concentrate glucose, and 4.25% Dianeal) were prepared and injected into the abdominal cavity of five ddY-mice, 5 mL every day for one month. The monolayer of the mesothelial cells was carefully removed from the liver surface by the imprint technique. Then, the mesothelial cell damage was evaluated by using trypan blue staining and comparing the results. Trypan blue-stained cells in 100 mm2 were observed in 7.0% of the control, 15.4% of the Ringer's solution, 18.7% of the lactate, 23.2% of the high-concentrate glucose, and 22.4% of the 4.25% Dianeal group, respectively. The damaged cells were significantly (p < 0.05) greater in the 4.25% Dianeal group than in the control group, and those in the high-concentrate glucose group also appeared to be greater in number compared to the control group It is concluded from these results that damage to the mesothelial cells is induced by chronic exposure to high-glucose dialysate, and its pathogenesis is deeply related to high concentration of glucose.

Animals↗

Staining procedure to detect viability and the true acrosome reaction in spermatozoa of various species.

A simple dual stain procedure (DS) for simultaneously determining sperm viability and acrosomal status is described. The DS includes the use of vital stain trypan blue to detect live and dead spermatozoa and Giemsa to detect the presence or absence of an acrosome. For staining, spermatozoa are washed, incubated with trypan blue, washed, dried onto slides, and subjected to Giemsa. Dead spermatozoa stain blue in the postacrosomal region while live spermatozoa remain unstained. The acrosome stains light purple-dark pink while acrosome-free sperm remain unstained. This staining pattern enables differentiation of spermatozoa which have undergone a true acrosome reaction (TAR) from those which have undergone a false acrosome reaction (FAR). Incubation of bull, boar, ram, and stallion spermatozoa for 60 minutes at 37 degrees C in the presence of calcium ionophore A23187 increased the proportion of spermatozoa undergoing a TAR in all species except the stallion. Incubation of bull spermatozoa for up to 24 hours at 37 degrees C resulted in a decrease over time in the percentage of live acrosome-intact spermatozoa and a simultaneous increase in the percentage of spermatozoa categorized as having undergone a TAR and FAR. The DS could be a useful technique in evaluating sperm viability and acrosomal status in fertilization and clinical studies.

Acrosome↗

Comparative neurotoxic potential of glutamate, endothelins, and platelet-activating factor in cerebral cortical cultures.

The excitatory amino acid glutamate, the peptides endothelin-1 and -3, and the phospholipid platelet-activating factor have been implicated in ischemic injury to the nervous system. To determine if, like glutamate, endothelins and platelet-activating factor are directly toxic to neurons, we examined their effects on lactate dehydrogenase release and trypan blue dye exclusion in rat cerebral cortical cultures. Glutamate (1 mM) increased lactate dehydrogenase release by approximately 75% and reduced the number of cells excluding trypan blue dye by approximately 50%. In contrast, endothelins (0.5 and 100 nM) and platelet-activating factor (0.1 and 10 microM) had no effect on these indices of cell injury. Endothelins and platelet-activating factor appear more likely to act on blood vessels than on neurons or glia as mediators of ischemic injury.

Animals↗

Phosphatidylinositol-3 kinase/Akt and GSK-3 mediated cytoprotective effect of epigallocatechin gallate on oxidative stress-injured neuronal-differentiated N18D3 cells.

Epigallocatechin gallate (EGCG) is one of most famous compounds of green tea. EGCG suppresses apoptosis induced by oxidative radical stress through several mechanisms. This study was designed to investigate whether EGCG plays a cytoprotective role by activating phosphatidylinositol-3 kinase (PI3K)/Akt-dependent anti-apoptotic pathway and inhibiting glycogen synthase kinase-3 (GSK-3) activity in oxidative stressed N18D3 neural cells. N18D3 cells, mouse neuroblastoma X dorsal root ganglion hybrid cell line, were pre-treated with EGCG or z-VAD-fmk, non-selective caspase inhibitor used as a control substance, for 2 h. The N18D3 cells were then exposed to low concentration of H(2)O(2) (100 microM) for 30 min, and further incubated for 24 h. MTT (3,[4,5-dimethylthiazol]-2-yl) assay and trypan blue staining were used to identify cell viability. Immunoreactivity (IR) of PI3K, Akt, and GSK-3 beta were measured by Western blotting. MTT assay and trypan blue staining showed that EGCG and z-VAD-fmk significantly increased cell viability, and IR of PI3K, phospho-Akt and phospho-GSK-3 beta was significantly increased in the cells treated with EGCG, but not in z-VAD-fmk treated. These results imply that EGCG has neuroprotective effect by increasing PI3K/Akt-dependent anti-apoptotic signals.

Amino Acid Chloromethyl Ketones↗

Role of Kupffer cells in the pathogenesis of hepatic reperfusion injury.

The purpose of this study was to evaluate the role of Kupffer cell activation in the pathogenesis of reperfusion injury. In a blood-free liver perfusion model, pericentral hypoxia and reperfusion injury occurred. Lactate dehydrogenase (LDH) and malondialdehyde (MDA) release, oxygen uptake, and trypan blue staining were assessed. Within the first 10 min of reflow, LDH and MDA release reached maximal values of 44 U.g-1.h-1 and 115 nmol.g-1.h-1, respectively. Trypan blue cell staining was confined to pericentral regions of the liver lobule. When Kupffer cells were inactivated with GdCl3, release of enzymes and MDA was reduced significantly by > 50%, and hepatic cell death was almost completely absent. Since increases in MDA suggested involvement of free radicals, livers were perfused with phenyl N-t-butylnitrone (5 mM), a spin-trapping agent. Analysis of liver tissue by electron paramagnetic resonance spectroscopy revealed a typical six-line spectrum, providing direct evidence that carbon-centered radicals were generated on reflow. GdCl3 treatment decreased radical adduct formation by approximately 50%. Collectively, these results strongly support the hypothesis that activation of Kupffer cells plays an important role in the pathogenesis of hepatic reperfusion injury.

Animals↗

Effect of teratogenic and related dyes on the haemoglobin nitrite sensitivity reaction.

The teratogenic dyes trypan blue and Evans blue have a marked and immediate action on the oxidation stability of intracellular haemoglobin in rats. Of the proved non-teratogenic substances tested only o-tolidine has an effect on the haemoglobin stability, and this effect is slow. It is suggested that the effect of the teratogens on the haemoglobin oxidation sensitivity is due to interference with the protein component of the flavoprotein enzymes.

Animals↗

Cytotoxicity and mutagenicity of vapor-phase pollutants in rat lung epithelial cells and Chinese hamster ovary cells grown on collagen gels.

Lung epithelial cell (cell line designated LEC) and Chinese hamster ovary (CHO) cells were grown on hydrated collagen gels and exposed directly to toxic vapor-phase pollutants. The cells were exposed to graded concentrations of phenol, formaldehyde, a volatile fraction of process stream material from an experimental coal gasifier and the nonparticulate, vapor phase of diesel engine exhaust. During exposures, the cells were maintained at an air/collagen interface by removing the medium overlying the hydrated collagen gel. Morphological changes indicative of cell retraction were found in LEC cell cultures exposed to phenol, formaldehyde, or diesel exhaust. Damage following exposure to the toxicants was quantitated in LEC and CHO cells by Trypan blue dye exclusion, a measure of plasma membrane integrity. Clone-forming ability was also used to measure cell survival in CHO cells. When measured by Trypan blue dye exclusion, phenol (EC50 = 2.1 mg/l) caused membrane damage to LEC cells but not CHO cells, while formaldehyde (EC50 = 31 and 42 micrograms/l for LEC and CHO, respectively) and diesel exhaust (EC50 = 11 and 29% of tailpipe exhaust in LEC and CHO cells, respectively) caused damage to both cell types. No cytotoxicity was observed in LEC or CHO cells exposed to the fraction from the coal gasifier. Essentially no mutagenic activity was associated with the exposure of CHO cells to formaldehyde or the vapor phase of diesel exhaust. Mutagenic activity was found in CHO cells exposed to ethylene oxide, the positive control. The results of this study indicate that mammalian cells grown on collagen gels can readily be exposed to vapors of chemicals and chemical mixtures. The cell exposure system may be generally useful in the analysis of toxic damage to mammalian cells resulting from gaseous or vapor-phase pollutants.

Air Pollutants↗

Group B streptococcal beta-hemolysin promotes injury of lung microvascular endothelial cells.

Group B streptococci (GBS) are the leading cause of pneumonia and sepsis in human newborns. Exudative pulmonary edema and alveolar hemorrhage seen in GBS pneumonia indicate vascular damage, and we reported that GBS injure lung microvascular endothelial cells (LMvEC) both in vivo and in vitro. The specific GBS factors causing LMvEC injury are uncertain, but GBS beta-hemolysin activity is associated with lung epithelial cell injury. We hypothesized that GBS beta-hemolysin contributes to LMvEC injury and exudative pulmonary edema. To test this hypothesis we used isogenic nonhemolytic and hyperhemolytic GBS mutants derived by transposon insertional mutagenesis from three different wild-type strains. Hemolytic titers for each strain were calculated using live GBS and Tween 80/starch-stabilized extracts of log-phase GBS. All nonhemolytic mutants lacked detectable hemolytic activity, whereas hyperhemolytic mutants produced 4-16 times the hemolytic activity of their parent strains. LMvEC injury was assayed by light microscopy, the release of lactate dehydrogenase, trypan blue nuclear staining and Evans blue-albumin flux. Compared with the parent strains, all nonhemolytic mutants caused significantly reduced, and all hyperhemolytic mutants caused significantly greater lactate dehydrogenase release from and trypan blue nuclear staining of LMvEC. Moreover, a nonhemolytic mutant caused reduced and a hyperhemolytic mutant caused increased Evans-blue albumin flux across polar LMvEC monolayers. These findings were corroborated by light microscopic evidence of hemolysin-associated damage to the LMvEC monolayers. We conclude that GBS beta-hemolysin promotes LMvEC injury and increases permeability in vitro, and speculate that GBS beta-hemolysin contributes to the pathogenesis of alveolar edema and hemorrhage in early onset GBS pneumonia.

Animals↗

Effects of mercury on human polymorphonuclear leukocyte function in vitro.

A variety of heavy metals are recognized as environmental pollutants, and although a significant body of literature exists on the acute toxicity of these metals in various tissues, little is known about the effects of metals such as mercury on host defense. Therefore, the effect of mercuric chloride (HgCl2) on human polymorphonuclear leukocytes (PMN) function in vitro was evaluated. The acute toxicity of HgCl2 for human PMN was calculated initially using vital dye exclusion (trypan blue), and lactate dehydrogenase (LDH) release. Concentrations of HgCl2 less than or equal to 10(-6) M did not induce significant LDH release, or uptake of trypan blue. Additionally, HgCl2 at less than or equal to 10(-7) M produced no ultrastructural alterations in the PMN. The effects of HgCl2 on human PMN functions involved in host defense were evaluated next. HgCl2 consistently suppressed human PMN adherence, polarization, chemotaxis, and erythrophagocytosis at concentrations between 10(-6) and 10(-17) M. Because of the established role of oxygen metabolites in host defense, the effects of HgCl2 on human PMN chemiluminescence and H2O2 production were evaluated next. These studies demonstrated that low concentrations of HgCl2 (ie, 10(-9)-10(-15) M) significantly enhanced chemiluminescence, as well as stimulated H2O2 production by the PMN. These studies clearly demonstrate the ability of extremely low levels of HgCl2 not only to suppress various PMN functions involved in host defense, but also to stimulate oxygen metabolism. In vivo, these HgCl2 effects would not only compromise host defense but also promote tissue injury via the local production of oxygen metabolites.

Cell Adhesion↗

Arterial endothelial denudation by intraluminal use of papaverine-NaCl solution in coronary bypass surgery.

OBJECTIVES: Preservation of endothelial integrity during coronary artery bypass grafting is considered important for short- and long-term patency of the graft. In current literature there are controversial data about the safety of papaverine, a vasorelaxant widely used in coronary artery bypass grafting. Accordingly, we examined the immediate effects of papaverine on the endothelial morphology of arterial grafts and on viability of cultured human coronary artery endothelial cells. METHODS: Totally 22 segments of the radial artery were collected from 11 patients undergoing coronary artery bypass grafting. The segments were cut from the distal redundant parts of the arteries, which were not required for bypass grafting. A small distal segment of the artery was excised and placed into autologous heparinized whole blood (control segment). The rest of the graft, still remaining proximally attached to the circulation, was treated intraluminally with papaverine-NaCl solution (pH 4.2) for 5 min, after which another small distal segment was excised for the study (papaverine-treated segment). Segments were then perfusion-fixed and the endothelial surface was examined by scanning electron microscopy. Endothelial denudation was assessed and its severity graded. Additionally, viability of cultured human coronary artery endothelial cells after treatment with papaverine was assessed with trypan blue staining. RESULTS: Treatment with papaverine solution markedly increased the endothelial denudation (grades from 6.2+/-1.7 to 10.0+/-3.5; mean+/-SD; P=0.004). Papaverine-treatment increased trypan blue staining of cultured human coronary artery endothelial cells regardless of papaverine diluent (normal saline of pH 4.5 or 7.4 or blood). CONCLUSIONS: Treatment of arterial grafts with papaverine solutions apparently damages endothelial cells. Thus, the clinical practice of dilating arterial bypass grafts with papaverine should be reassessed, and alternative methods of vasodilatation should be considered.

Aged↗

The effects of focused extracorporeal pyrotherapy on a human bladder tumor cell line (647 V).

UNLABELLED: Human transitional cell bladder carcinoma cell-line 647 V has been used to evaluate the effects on tumor cells in vitro of a new technique: focused extracorporeal pyrotherapy (F.E.P.). The device is made of multi-sources of piezoelectric ceramics focused at 320 mm. The focal area is 10 mm. high on 1.5 mm. width, and shots of 0.25 to 0.50 seconds were delivered on 4 groups of cell pellets placed in a polyurethane tube at the focus. Trypan blue MTT cell growth curve and Colony forming tests were used. There was a significant reduction (Student's t test) of the cell variability rate on the Trypan Blue test, 5% (in the treated Group) against 95% (control Group). The growth curve was flattened whether 0.50 second shots were single or repeated. The colony formation test was also significantly altered: 5.7% (treated group) against 70% (control group). CONCLUSION: focused extracorporeal pyrotherapy is able to alter or kill tumor cells in vitro.

Carcinoma, Transitional Cell↗

Lidocaine-induced cell death in a human model of neuronal apoptosis.

BACKGROUND AND OBJECTIVE: Clinical studies suggest that lidocaine may induce irreversible neurological damage after spinal application in human beings. The mechanisms underlying the possible cytotoxic action of lidocaine have only been suggested from animal studies. This study aimed to investigate if lidocaine exhibited cytotoxic action in a human model widely used for the study of neuronal apoptosis. This is important to know as it may help one to judge on possible neurotoxic risks imposed by the spinal application of lidocaine. METHODS: The concentration- and time-dependent effects of lidocaine on retinoic acid-differentiated human neuroblastoma SH-SY5Y cells were quantified by trypan blue staining, the release of lactate dehydrogenase, immunocytochemistry and flow cytometry. RESULTS: The local anaesthetic caused a significant increase in the number of cells staining positive for trypan blue, a significant increase of LDH release into the incubation medium, and a significant increase of 7AAD and annexin V binding. Lidocaine induced apoptosis already at 3 mm. At a concentration of 10 mmol 47% of the cells and at 30 mmol 98% of the cell population was necrotic. Both necrosis and apoptosis were time-dependent. CONCLUSIONS: The results demonstrate that lidocaine exhibited neurotoxic effects in a human model established for the study of drug-induced neuronal apoptosis. The results were consistent with the neurotoxic clinical effects of lidocaine. These effects may be produced by more than a single mechanism.

Apoptosis↗

Cryopreservation and culture of human corneal keratocytes.

PURPOSE: To assess the effects of two different concentrations of albumin in a cryoprotective solution and two freezing methods on human corneal keratocyte ctyopreservation. METHODS: Isolated keratocytes were used for cryopreservation. Solutions of 10% dimethylsulfoxide with either 2% or 10% human albumin were used as cryoprotective agents. Cells either were transferred directly into a -80 degrees C freezer (freezing rate, 2 degrees C/min) or were cooled in a programmed freezer (1 degrees C/min until -40 degrees C and then 10 degrees C/min), which resulted in four different cryopreservation protocols. Cells were stored at -80 degrees C, then were thawed at 37 degrees C, and subsequently were cultured. Keratocytes were studied by means of trypan blue staining, growth assay, apoptosis assays, transmission electron microscopy, and immunochemistry. RESULTS: The percentage of cells that were alive after thawing ranged from 80% to 99% by trypan blue staining and from 45% to 60% by flow cytometry. The ratio of the number of living cells at the end of primary culture after cryopreservation to that before cryopreservation was significantly (P=0.04) higher after direct transfer into the -80 degrees C freezer than after controlled-rate freezing, whereas the albumin concentration had no significant influence on this ratio (P=0.45). The percentage of apoptotic cells was significantly higher after cryopreservation than in the control group of noncryopreserved cells; more than 5% 24 hours after thawing. Cryopreservation did not modify the keratocyte ultrastructure. Fibroblast growth factor dramatically decreased the serum-induced cell expression of alpha smooth muscle actin, whereas cryopreservation had no influence on this cell expression. CONCLUSIONS: A freeze-thaw trauma, which was related to cryopreservation-induced cell apoptosis, was revealed during primary culture after thawing. Direct transfer into the -80 degrees C freezer resulted in better postcryopreservation growth in the culture than controlled-rate freezing. A change in albumin concentration from 2% to 10% did not affect the results.

Actins↗

Effects of intraocular epinephrine on the corneal endothelium of rabbits.

Epinephrine is frequently used in the phacoemulsification to dilate pupils. To determine the effects of different concentration of epinephrine on the corneal endothelial cells, twenty-eight rabbit eyes were equally divided into four groups. Solutions, which contained normal saline, 1:1000 epinephrine, 1:5000 epinephrine and 1:10000 epinephrine respectively, were injected into the anterior chambers of the eyes of four groups of rabbits. In vivo morphological changes of corneal endothelium and changes of thickness were checked with specular microscopy. In vitro morphological evaluation of corneal endothelium was observed in excised corneal buttons stained with alizarin red with trypan blue, and with scanning electron microscopy. Our results showed that there was no significant difference in cell density and corneal thickness among the four groups. Alizarin red with trypan blue stain and SEM exam revealed smooth and distinct cell borders of endothelial cells in each group. Intracameral injection of epinephrine does not produce toxic effect on corneal endothelial cells in rabbits.

Animals↗

Comparison of Media for the Isolation of Cryptococcus neoformans.

Four media, Staib's Guizotia abyssinica, trypan blue, and Staib's with 2 and 10 mg of methyl violet per liter, were compared for the selective and differential isolation of Cryptococcus neoformans from environmental samples. Trypan blue medium allowed for the differentiation of C. neoformans colonies from Candida albicans colonies several days earlier than did Staib's medium. The addition of methyl violet to Staib's medium was found to be inhibitory to some strains of all species tested. Diphenyl in Staib's medium inhibited the growth of 30 strains of C. neoformans and C. albicans.

Journal Article↗