Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ACRIDINES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18Linked to original sources

Preclinical pharmacologic investigations on a new group of acridine derivatives with oncostatic activity. II. Chronic action.

Influence of 1-nitro-9-(2-dihydroxyethylaminoethylamino)-acridines (C-835) and 1-nitro-9-(3-isopropylamino-propylamino)-acridines (C-846) on animal organs and their basic functions was studied in the chronic action. Rabbits responded to the drugs with considerable tolerance which was less manifested in rats. Slight toxic effect was observed only after maximal doses with which the animals survived 3-month exposure. Enzyme studies and creatinine clearance test did not show any clear-cut impairment of hepatic and renal function. Neither did the preparations influence the red and white blood system, nor the blood clotting time. Microscopic examinations showed their slight (initially) morphologic changes which later passed into degenerative changes (liver, kidney, myocardium) as well as typical of oncostatics, changes in intestinal villi, nuclei and lymphatic system. Also desquamation of intestinal epithelium, hypertrophy of their lamina propria, impairment of spermato- and spermiogenesis as well as atrophy of lymphatic germinal centers and decreased number of small lymphocytes in lymph nodes and spleen were noted. Deviation between the results of function and morphologic tests were discussed. Microscopic changes observed after treatment of the tested acridine derivatives were considered too small to damage the particular organs function.

Aminacrine↗

Immunochemistry of conjugates prepared from serum albumins and acridine nitrogen mustards (ICR mutagens).

Antibodies elicited in rabbits by immunization with conjugates prepared from serum albumins and nitrogen mustard derivatives of quinacrine (atebrin) were found to have strong binding sites complementary to the quinacrine hapten. The characteristic absorption spectrum of quinacrine made possible accurate determinations of the antigen-antibody composition of the serological precipitates. Conclusive evidence that such antibodies, in addition to reacting with the quinacrine component of heterologous protein test conjugates, bind quinacrine itself, as well as closely related acridine haptens, was provided by quantitative inhibition studies. Atebrin and the hydroxy precursors of several heterocyclic nitrogen mustards caused more than a 50% inhibition of the antigen-antibody reactions. The antibodies elicited by the quinacrine-protein conjugates in ascites tumor-bearing mice substantially neutralized the antitumor effectiveness of the low dosages (0.5 to 2.0 mumol/kg) of the acridine nitrogen mustards that were required for a demonstration of chemotherapeutic activity. In contrast, nitrogen mustard, which has no quinacrine moiety, was not affected. Immunization with unaltered serum albumin had no influence on the activity of the acridine nitrogen mustards. Quantitative in vitro inhibition studies allowed satisfactory predictions in vivo immunological reactivity.

Animals↗

Accumulation and release of acridine derivatives by intact platelets.

A new approach to the investigation of accumulation of acridine derivatives and release by platelets is proposed. At high concentrations of acridine orange (AO) inside dense bodies, a two component fluorescence spectrum with maxima at 530 and 640 nm has been recorded. Computer deconvolution of spectra provided additional information on the mechanism of dye accumulation and release. AO release from PAF-stimulated human platelets was analysed in details. A 10 +/- 2.5-s delay in alteration of the shortwave component was observed. Changes in the longwave component were not preceded by a lag period. These data suggest a possibility of dye redistribution in the cell after stimulation.

Acridine Orange↗

A bacterial mutagenicity study of rivanol, an acridine derivative used as an abortifacient.

We have used the forward mutation to resistance to 6 azauracil to test the mutagenicity of rivanol (6,9 diamino 2-ethoxy acridine) on Escherichia coli. Rivanol has been used to induce therapeutic abortions in midpregnancy and is considered safe and effective for this purpose. The findings reported here that rivanol, like other acridines, is a mutagen, at least in procaryotes, suggests that such use of rivanol be reconsidered in light of its possible genetic toxicity.

Abortifacient Agents↗

Cytotoxicity of some potential DNA intercalators (carbazole, acridine and anthracene derivatives) evaluated through neutrophil chemiluminescence.

A modifying effect of potential DNA intercalators, belonging to a group of carbazole, acridine and anthracene derivatives, on the course of luminol-dependent chemiluminescence of neutrophils (polymorphonuclear leucocytes; PMNL) in the process of phagocytosis was studied. This effect was also examined in reactive-oxygen-species-generating non-cellular reaction systems consisted of myeloperoxidase or xanthine oxidase. Adriamycin (Doxorubicin), which is widely applied to neoplasm therapy, was used as a reference intercalator in the conducted experiments. It was demonstrated that some structurally different derivatives of carbazole inhibited the light emission from N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced neutrophils to the same degree as adriamycin. It can be suggested that the same inhibitory effect was caused by either a different cellular distribution of the derivatives or different interactions of the derivatives with reactive oxygen species in the investigated systems. Measurements of chemiluminescence suggested that the thiol group in one of the carbazole derivatives could strongly interfere with oxidative cell metabolism. In contrast to the analogous derivative of carbazole, both anthracene and acridine derivatives, possessing an N-1'-hydroxyethyl-ethylenodiamino group, induced different increases in chemiluminescence accompanying the process of neutrophil phagocytosis. Cytotoxicity of the investigated derivatives, being tested previously in cancer cells with a sulphorhodamine B assay, was found to possess a specific representation in the complex picture of the derivative-caused modification both of neutrophil and enzymatic non-cellular chemiluminescence. We suggest that chemiluminescence assays may serve as a helpful tool in the primary screening of drug cytotoxicity.

Acetaldehyde↗

Experimental parameters and a biological standard for acridine orange detection of drug-induced alterations in chromatin condensation.

We investigated a number of sample-preparative parameters for use of flow cytometry to detect chromatin condensation in cells stained with acridine orange after DNA in situ is partially denatured by acid treatment. Stability and data reproducibility for both control and drug-treated ME-180 and HT-29 cells were assessed over: a range of cell concentrations in 2.56 X 10(-5) M acridine orange; 15 days of storage in fixative; various times between RNase digestion and staining; and increasing times between staining and analysis. Listmode data for red and green fluorescence were collected and mean fluorescence intensities of G1, S, and G2 subpopulations of HT-29 and ME-180 cells were computed. These were normalized to data from HeLa-S3 cells and fluorescent microspheres to control for inter-experiment variations in staining and instrumental parameters, respectively. The normalized red and green fluorescence data were used to calculate alpha 1 for G1 cells [alpha t = red fluorescence/(total fluorescence)]. Exponentially growing HeLa-S3 cells were a very consistent and reproducible biological standard to control for fixation and staining variability. Mean fluorescence intensities of control and difluoromethylornithine-treated (i.e., polyamine depleted) cells remained stable and reproducible across all tested ranges for cell concentration, storage in fixative, and time after RNase digestion. This technique can thus be used to evaluate difluoromethylornithine-induced changes in chromatin condensation of samples stored for as long as 2 weeks and analyzed all on 1 day.

Acridine Orange↗

In situ flow cytometric analysis of nonyl acridine orange-stained mitochondria from splenocytes.

Due to its spectral characteristics, the fluorochrome nonyl acridine orange (NAO) (lambda abs:489 nm, lambda em:525 nm), which is spontaneously incorporated by mitochondria with a high relative specificity, provides a new probe for the in situ study of these organelles by flow cytometry. In 15 min at 20 degrees C, the dye at 4.75 X 10(-6) M saturates the mitochondrial binding sites present in 1.5 X 10(6) cells. Unlike Rh 123, the fixation of the probe is not affected by the action of uncouplers and ionophores. Unlike acridine orange, its binding is not sensitive to nucleases. By studying the mitochondrial incorporation of the fluorochrome during the cell cycle of murine splenocytes, it was possible to show that the biogenesis of NAO-stained mitochondrial constituents mainly occurs during the G1 phase.

Acridine Orange↗

Control of cellular proliferation in HeLa-S3 suspension cultures. Characterization of cultures utilizing acridine orange staining procedures.

Growth control is investigated in detail in fed and unfed HeLa-S3 suspension cultures. Two-step acridine orange staining and flow cytometric analysis indicated declines in cellular red fluorescence (proportional to RNA content) of 40-50% between exponential and plateau phase in both culture types. Cellular green fluorescence (DNA content) assessed simultaneously indicates an increment of cells with Gi-DNA content in plateau phase in the unfed cultures, while fed cultures show a brief increment in G1-phase cells in the transition phase followed by a recovery in plateau phase to a value similar to that of exponential cultures. Temporal declines in the 3H-thymidine pulse-labeling index are observed in both culture systems. These data along with the flow cytometry data indicate a distinct G1-arrest in the unfed plateau cultures and suggest a random arrest of cells about the cell cycle in fed plateau cultures. Acidic acridine orange staining and flow cytometric analysis furthermore indicate the occurrence of a quiescent population comprising approximately 345 of the total cells and consisting of both dead and viable cells in plateau phase unfed cultures. In contrast, fed plateau cultures show approximately 14% quiescent, mostly dead cells. Also, both culture systems show temporal declines in the clonogenic index and a longer cell-cycle transit time in plateau phase relative to exponential phase. These findings confirm earlier work which indicates that the environment has a profound influence on the mode of growth control for mammalian cells in vitro.

Acridine Orange↗

Influence of acridine tracer dyes on neutrophil function.

A study was performed to elucidate the effect of two commonly used fluorescent dyes in in vivo microscopic studies, acridine orange (AO) and acridine red (AR), on the ability of phorbol myristate acetate (PMA)- or formyl peptide (fMLP)-stimulated human neutrophils to adhere to a bovine serum albumin matrix and to generate superoxide anions (SOX). Unlabeled stimulated human neutrophils showed 36 +/- 9% (PMA, 10(-7) M) and 11 +/- 7% (fMLP, 10(-7) M) adherence to the matrix. This adhesion was CD18 dependent as evidence by 98% and 92% reduction, respectively, when the anti-CD18 antibody IB4 was included. A dose-dependent inhibition of stimulated human neutrophil adhesion was evident after 30 min of in vitro dye labeling and the EC50 was approximately 70 micrograms/ml (AR) and 145 micrograms/ml (AO). SOX generation by PMA-stimulated neutrophils was unaffected up to 100 micrograms/ml AR and AO but was reduced by 40-60% at higher doses. Rabbit neutrophils labeled in vivo or in vitro with 100 micrograms/ml AR exhibited 41% and 61% lower SOX generation, respectively. The study indicate that neutrophil function, in terms of ability to adhere to a BSA matrix using CD11/CD18 integrins and to generate SOX upon stimulation, is reduced depending on the dose and choice of fluorescent dye. Caution should be exercised when using these compounds at high concentrations in studies of PMN function.

Acridine Orange↗

The capacity of lysosomes of cultured mammalian cells to accumulate acridine orange is destroyed aby hyperthermia.

Lysosomes of cultured mammalian cells, derived from a transplantable murine mammary adenocarcinoma, irreversibly lose their capacity to accumulate the fluorescent dye acridine orange after hyperthermia. As acridine orange may be regaraded as a fluorescent probe of the internal pH of the lysosomes, we may conclude that the ability of lysosomes to maintain a low internal pH is destroyed by hyperthermia. The effects of hyperthermia on lysosome fluorescence and on cell survival show several similarities: in both cases hyperthermia is more effective at low pH, below pH 7.0, and CCP (carbonylcyanide-m-chlorophenylhydrazone) enhances effects at low pH, but has no clear effect at pH 8.0. This leads to the conclusion that effects on lysosomes are an important and early event in cellular injury caused by hyperthermia. The activation energy, however, obtained for the effects of hyperthermia on lysosome fluorecence is about a factor of two lower athan the activation energy reported for cell survival after hyperthermia. This suggests that the effect on lysosomes is not directly caused by hyperthermia but is triggered by some other hyperthermia-induced cellular damage.

Acridine Orange↗

Sequential Q- and Acridine orange-marker technique.

A standardized Q- and acridine orange (AO)-fluorescence dual marker technique was described. It involved preservation of unstained chromosome slides in a vacuum desiccator up to 18 months, Q-staining, destaining, and treatment in Hanks' solution, pH 5.1, at 85 degrees C for 13 min, and acridine orange staining. Q-markers were found at the paracentromeric regions of chromosomes 3 and 4, the short arms and the satellites of the acrocentric chromosomes, while AO-marker spots were on the satellite-stalks of the acrocentrics. The advantage of the dual marker technique was illustrated by the determination of the origin of trisomy 22 in a spontaneous abortus.

Abortion, Spontaneous↗

Variation in human acrocentric chromosomes with acridine orange reverse banding.

Twenty-five normal subjects were studied by acridine orange reverse (RFA) banding in order to obtain a preliminary estimate of the type and frequency of variations in color and length. Color variations were classified into 1 of 6 colors and size variations into 1 of 5 levels. The same cells were also studied by Q banding. Acridine orange reverse banding was found to be more useful than Q banding for characterizing variations in chromosomes 14, 15, 21 and 22. In addition, it was found that there was no consistent relationship between pale or bright Q banding and the various colors observed with RFA banding. For the optimal characterization of a chromosomal variation, multiple banding technics, including RFA banding, are necessary.

Acridines↗

Acridine orange staining of the mammalian fibroblast cell coat.

Acridine orange selectively binds to glycos- and galactosaminoglycan (GAG) compounds in the presence of Na+ in low concentrations. We have worked out a cytochemical method, which is suitable for the specific demonstration of surface GAG components. The method consists of a glutaraldehyde prefixation, an acridine orange block-staining for 48 h and an OsO4 postfixation for some hours. The specificity of the staining was verified with the help of fluorimetric--in vitro--measurements and enzymatic digestions, respectively.

Acridine Orange↗

Fluorescence microscopy of viable mast cells stained with different concentrations of acridine orange.

Freshly harvested rat peritoneal mast cells were stained with different concentrations of acridine orange, a metachromatic fluorochrome known to form complexes with chromatin and muscopolysaccharides. Fluorescence metachromasia was observed in cytoplasmic granules in cell populations with intracelluar dye contents as low as 5 X 10(-16) mole per cell, one-half decade lower than required to produce metachromatic staining of the nucleus. Cytoplasmic granules did not stain uniformly throughout the cell; some granules exhibited red fluorescence and others green. As the amount of acridine orange uptake per cell was increased, cytoplasmic fluorescence became uniformly red and nuclear fluorescence gradually changed from green to yellow.

Acridine Orange↗

[Effect of acridine dyes on the ultrastructure of mitochondria in HeLa and LM cells].

Fluorescent staining of mitochondria in living HeLa cells and mouse fibroblasts (LM) with acridine dyes has been reported recently. The investigations are now extended to electron microscopy. Dyes used in our vital staining experiments are 10-ethyl- and 10-(2-iodethyl)acridine orange hydrochloride (EAO, IAO). The mitochondria of vitally stained cells are compared with untreated material. There are dramatic changes of the ultrastructure of HeLa mitochondria within the short incubation time of a few minutes. During the same time only small alterations of LM mitochondria could be observed.

Acridine Orange↗

Complex formation of acridine orange with single-stranded polyriboadenylic acid and 5'-AMP: cooperative binding and intercalation between bases.

The binding of acridine orange to single-stranded polyribonucleic acid at low polymer to dye ratios exhibits cooperative behavior of the kind observed with other simple polyanions. It is thus attributed to electrostatic interaction between polymer and stacked dye molecules. At higher polymer to dye ratios, however, distinct deviations from the predictions of the basic theory occur. These are interpreted by additional non-cooperative binding of acridine orange to the bases of the polymer subunits owing to dye-base stacking. This effect is studied also with 5'-AMP monomers where it likewise leads to complex formation. Both systems are investigated experimentally by means of the changes produced in the dye spectrum. Based on quantitative analyses the equilibrium constants of both systems are evaluated and discussed. They indicate a sandwich-type of intercalation of dye between two bases of the single-stranded polymer.

Acridine Orange↗

Na/H- and Cl/OH-exchange in rat jejunal and rat proximal tubular brush border membrane vesicles. Studies with acridine orange.

The quenching of the acridine orange fluorescence was used to monitor the formation and/or dissipation of a delta pH in brush border vesicles isolated from rat kidney cortex or rat jejunum. Similar findings were obtained with both brush border membrane vesicle preparations. Acridine orange fluorescence was quenched by a preset delta pH (intravesicular acid) or by the ionophore (valinomycin/CCCP) dependent development of a delta pH (intravesicular acid) under conditions of potassium efflux. Under sodium efflux conditions, an acidification of the intravesicular space occurred: a) due to indirect (electrical) coupling of sodium and proton fluxes; b) due to directly coupled sodium/proton exchange. The initial rate of the dissipation of a preset delta pH was accelerated by pulse injections of sodium in a saturable manner; lithium partially replaced sodium. The sodium dependent acceleration in the rate of dissipation of a preset delta pH was not altered by replacing gluconate with chloride. Amiloride was an inhibitor of directly coupled sodium/proton exchange. An inwardly directed chloride gradient did not induce intravesicular acidification. The initial rate of the dissipative proton fluxes (preset delta pH) was slightly accelerated by an outwardly directed chloride gradient. Sodium/proton exchange dependent acidification of the intravesicular space was not altered by replacing gluconate with chloride. These results clearly document the existence of sodium/proton exchange in both renal and intestinal brush border membrane vesicles. In contrast, Cl/OH exchange--under our experimental conditions--must have a much smaller rate than Na/H exchange.

Acridine Orange↗

[The effect of actinomycin d, acridine dyes and related substances on the biosynthesis of nucleic acids in normal and leukemic white blood cells. Comparative investigation in intact cells and in a cell-free system (author's transl)].

Acridine dyes inhibit the incorporation of 3H-thymidine and 3H-uridine in intact cells to the same extent as Actinomycin D. In contrast to Actinomycin D, RNA synthesis by DNA - dependent RNA polymerase in a cell-free system is inhibited at lo2 higher concentrations of acridine dyes, only. Possible differential effects on the cell membrane resulting in decreased intracellular pools of uridine and thymidine are discussed.

Acridines↗