Formononetin alleviates cerebral ischemia-reperfusion injury in rats by targeting the PARP-1/PARG/Iduna signaling pathway

Formononetin has been demonstrated to protect against cerebral ischemia-reperfusion injury, however its mechanism has to be further researched. This study examined the effect of formononetin on cerebral ischemia-reperfusion injury in rats using the PARP-1/PARG/Iduna signaling pathway. In male SD rats, a model of cerebral ischemia-reperfusion injury was developed. Animals were randomly assigned to one of eight groups: Sham operation, Sham operation + formononetin, MCAO, MCAO + formononetin, PARP inhibitor (PJ34) + MCAO, formononetin + PJ34 + MCAO, PARG inhibitor (Ethacridine lactate) + MCAO, and ethacridine lactate + formononetin. The neurological deficit test, TTC staining, HE staining, Nissl staining, TUNEL staining, and western blotting were utilized to assess formononetin's protective effects in MCAO rats. The data show that formononetin can effectively alleviate neurological dysfunction and pathological changes in brain tissue in rats with cerebral ischemia-reperfusion injury, reduce the area of cerebral infarction and neuronal apoptosis, decrease the protein levels of PARP-1, PARG, Caspase-3, P53, and AIF in brain tissue, and increase the protein levels of Iduna and p-AKT. As a result, we concluded that formononetin improves brain ischemia-reperfusion injury in rats by modulating the PARP-1/PARG/Iduna signaling pathway.

Evaluation efficacy and safety of epidural analgesia in second-trimester induced labor: A single-center, prospective, non-randomized, controlled study

BACKGROUND

Second-trimester induced labor in pregnant women was often more likely to suffer from psychological and physiological double pain. However, the analgesic management received less attention, and the optimal analgesic mode for second-trimester induced labor had not been determined. Our objective was to evaluate the feasible of epidural analgesia (EA) in second-trimester induced labor.

METHODS

From January 2020 to December 2021, Primipara who planned to undergo second-trimester induced labor in the First Affiliated Hospital of Yangtze University were collected. The method of labor induction was oral mifepristone + amniotic cavity injection of Ethacridine Lactate. Based on whether or not patients received epidural analgesia, which were divided into EA group (30 cases) and non-EA (NEA) group (30 cases). The primary outcome were visual analog scale (VAS) score of pain and result of follow-up, the secondary outcomes included relative clinical parameter and labor duration.

RESULTS

Vaginal induction of labor was successful in both groups. There was no statistically significant difference in VAS of pain between the two groups before analgesia (P > .05), but the VAS of pain in the EA group was significantly lower than the NEA group (P < .05) after analgesia or at delivery. The following outcomes showed no statistical difference between two groups: labor duration, postpartum hemorrhage, hemorrhage ≥ 500 mL, intrapartum injury, second days hemoglobin, C-reactive protein, antibiotic therapy days, hospitalizations days, and placenta residue (P > .05). The median hospitalization costs of EA group was 4697.5 yuan, and NEA group was 3673 yuan, the difference was statistically significant (P < .001). No adverse events related to EA occurred during hospitalization, only 3 patients showed mild lumbago and back pain after follow-up to three months postpartum, which was significantly relieved after proper rest.

CONCLUSION

EA can significantly reduce the pain of parturients, which may be effective and safe in the second-trimester induced labor.

Ethacridine inhibits SARS-CoV-2 by inactivating viral particles

The respiratory disease COVID-19 is caused by the coronavirus SARS-CoV-2. Here we report the discovery of ethacridine as a potent drug against SARS-CoV-2 (EC50 ~ 0.08 μM). Ethacridine was identified via high-throughput screening of an FDA-approved drug library in living cells using a fluorescence assay. Plaque assays, RT-PCR and immunofluorescence imaging at various stages of viral infection demonstrate that the main mode of action of ethacridine is through inactivation of viral particles, preventing their binding to the host cells. Consistently, ethacridine is effective in various cell types, including primary human nasal epithelial cells that are cultured in an air-liquid interface. Taken together, our work identifies a promising, potent, and new use of the old drug via a distinct mode of action for inhibiting SARS-CoV-2.

Epigenetic Changes During Human Thyroid Cell Differentiation

Objective: It has been demonstrated that the transcription factors TAZ (transcriptional coactivator with PDZ-binding motif), paired box gene 8 (PAX8), and NK2 homeobox 1 (NKX2-1) are coexpressed in the nucleus of thyroid cells. Furthermore, TAZ is known to enhance the transcriptional activity of PAX8 and NKX2-1 as well as the key thyroid-specific gene, thyroglobulin (TG), suggesting a critical role for TAZ in the control of thyroid cell speciation. We previously reported that the small molecule ethacridine, identified as a TAZ activator, was able to induce thyroid-specific transcription in endodermal cells differentiated from human embryonic stem (hES) cells using activin A. Since transcription factors are epigenetically regulated in cell differentiation, we investigated the epigenetic changes in the promoter regions of these key transcription factors during in vitro differentiation of hES cells into thyrocytes. Methods: We initially profiled chromatin accessibility using the technique of Assay for Transposase Accessible Chromatin sequencing (ATAC-seq), and then examined DNA methylation and histone acetylation in the promoter regions of the three selected thyroid transcription factors and the thyroid-specific genes during hES cell differentiation. Results: ATAC-seq analysis showed enriched chromatin accessibility of TAZ, NKX2-1, and PAX8 after exposure to activin A and ethacridine. There were no methylation changes found in the NKX2-1, PAX8, and TAZ promoters by bisulfite sequencing. In contrast, acetylation of histone H4, specifically acetylation of lysine 16, was observed in each of the promoters when measured by chromatin immunoprecipitation polymerase chain reaction assays, which correlated with the activity and expression of NKX2-1 and PAX8 as well as sodium/iodide symporter, thyroid stimulating hormone receptor, and TG genes. Conclusions: These results indicate that ethacridine treatment of activin A-derived endodermal hES cells leads to enhanced chromatin accessibility, which, in turn, allows histone H4 acetylation in the regulation of active genes for speciation of thyroid follicular cells from hES cells.

Porous poly(lactic acid) based fibres as drug carriers in active dressings

PURPOSE

The polymeric porous surface of fibres (PLA) may influence the kinetics of release of biologically active compounds (gentamicin, G and ethacridine lactate, R) affecting development of a bacterial biofilm.

METHODS

The porous fibres with different morphology were manufactured by the electrospinning method from ternary systems composed of PLA and selected solvents. Fibres morphology was examined using a scanning electron microscopy (SEM), their structure was analyzed by FT-IR ATR spectroscopy and differential scanning calorimetry (DSC). Changes in the drug release profile were measured using ICP/UV-Vis methods and the resulting bactericidal or bacteriostatic properties were tested by two-layer disk diffusion test in relation to various drug incorporation methods.

RESULTS

The porous fibres can be applied to produce drug-bearing membranes. The spectroscopic studies confirmed incorporation of gentamicin into the fibres and the presence of ethacridine lactate on their surface. Bimodal fibres distribution (P3) promoted faster release of gentamicin and ethacridine lactate from P3G and P3R materials. The electrospinning process coupled with the vapor induced phase separation influenced the glass transition temperature of the porous polymer fibres. The pre/post-electrospinning modification influenced the glass transition, maximum temperature of cold crystallization and melting point of the porous membrane, compared to the neat polymer. The polylactide fibres with gentamicin showed strong bactericidal effect on Gram-positive bacteria, while fibres with ethacridine lactate were bacteriostatic.

CONCLUSIONS

The obtained fibres with complex surface morphology can be used as a membrane in active dressings as they make it possible to control the release profile of the active compounds.

In-silico Design, ADMET Screening, MM-GBSA Binding Free Energy of Some Novel Isoxazole Substituted 9-Anilinoacridines as HER2 Inhibitors Targeting Breast Cancer

BACKGROUND

Human Epidermal development factor Receptor-2 (HER2) is a membrane tyrosine kinase which is overexpressed and gene amplified in human breast cancers. HER2 amplification and overexpression have been linked to important tumor cell proliferation and survival pathways for 20% of instances of breast cancer. 9-aminoacridines are significant DNA-intercalating agents because of their antiproliferative properties.

OBJECTIVE

Some novel isoxazole substituted 9-anilinoacridines(1a-z) were designed by in-silico technique for their HER2 inhibitory activity. Docking investigations of compounds 1a-z are performed against HER2 (PDB id-3PP0) by using Schrodinger suit 2016-2.

METHODS

Molecular docking study for the designed molecules 1a-z are performed by Glide module, in-silico ADMET screening by QikProp module and binding free energy by Prime-MMGBSA module of Schrodinger suit. The binding affinity of designed molecules 1a-z towards HER2 was chosen based on GLIDE score.

RESULTS

Many compounds showed good hydrophobic communications and hydrogen bonding associations to hinder HER2. The compounds 1a-z, aside from 1z have significant Glide scores in the scope of - 4.91 to - 10.59 when compared with the standard Ethacridine (- 4.23) and Tamoxifen (- 3.78). The in-silico ADMET properties are inside the suggested about drug likeness. MM-GBSA binding of the most intense inhibitor is positive.

CONCLUSION

The outcomes reveal that this study provides evidence for the consideration of isoxazole substituted 9-aminoacridine derivatives as potential HER2 inhibitors. The compounds, 1s,x,v,a,j,r with significant Glide scores may produce significant anti breast cancer activity and further in vitro and in vivo investigations may prove their therapeutic potential.

TAZ Induction Directs Differentiation of Thyroid Follicular Cells from Human Embryonic Stem Cells

OBJECTIVE

The differentiation program for human thyroid follicular cells (TFCs) relies on the interplay between sequence-specific transcription factors and transcriptional co-regulators. Transcriptional co-activator with PDZ-binding motif (TAZ) is a co-activator that regulates several transcription factors, including PAX8 and NKX2-1, which play a central role in thyroid-specific gene transcription. TAZ and PAX8/NKX2-1 are co-expressed in the nuclei of thyroid cells, and TAZ interacts directly with both PAX8 and NKX2-1, leading to their enhanced transcriptional activity on the thyroglobulin (TG) promoter and additional genes.

METHODS

The use of a small molecule, ethacridine, recently identified as a TAZ activator, in the differentiation of thyroid cells from human embryonic stem (hES) cells was studied. First, endodermal cells were derived from hES cells using Activin A, followed by induction of differentiation into thyroid cells directed by ethacridine and thyrotropin (TSH).

RESULTS

The expression of TAZ was increased in the Activin A-derived endodermal cells by ethacridine in a dose-dependent manner and followed by increases in PAX8 and NKX2-1 when assessed by both quantitative polymerase chain reaction and immunostaining. Following further differentiation with the combination of ethacridine and TSH, the thyroid-specific genes TG, TPO, TSHR, and NIS were all induced in the differentiated hES cells. When these cells were cultured with extracellular matrix-coated dishes, thyroid follicle formation and abundant TG protein expression were observed. Furthermore, such hES cell-derived thyroid follicles showed a marked TSH-induced and dose-dependent increase in radioiodine uptake and protein-bound iodine accumulation.

CONCLUSION

These data show that fully functional human thyroid cells can be derived from hES cells using ethacridine, a TAZ activator, which induces thyroid-specific gene expression and promotes thyroid cell differentiation from the hES cells. These studies again demonstrate the importance of transcriptional regulation in thyroid cell development. This approach also yields functional human thyrocytes, without any gene transfection or complex culture conditions, by directly manipulating the transcriptional machinery without interfering with intermediate signaling events.

Sonographic findings of uterine rupture with expulsion of the fetus into broad ligament

We report the sonographic findings of a rare case of uterine rupture with extrusion of the fetus into the broad ligament during a second-trimester abortion. Sonography revealed the empty uterus with an indistinct defect on the side wall and the dead fetus lying outside, surrounded by a thin membrane. At surgery, the uterine rupture was confirmed with the fetus lying in the broad ligament. This study shows the importance of timely sonography in second-trimester abortion, enabling immediate management and preventing further complications.

New ethacridine derivatives as the potential antifungal and antibacterial preparations

Until the 20th century fungal infections were rather easy cured, and the need of new antifungal drugs was low. However, low choice of antifungal preparations, their toxicity, limited spectrum of action, and ability to produce resistant strains show the need of new effective medicines for systemic fungal diseases in nowadays. Our goal of research was to synthesize new antimicrobial compounds containing three or more pharmacophores in one molecule. The initial 5-substituted-2-methylmercaptothiazolidin-4-ones were subjected to S-demethylation to yield 2-amino-substituted thiazolidinones. Ethacridine, nitrofuran aldehydes and nitrobenzene aldehyde as pharmacophoric amino or aldehyde group having compounds have been used. Antimicrobial (antifungal) activity of the new compounds was screened in vitro in these bacterial cultures: Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Bacillus subtilis ATCC 6633, Klebsiella pneumoniae ATCC 33499 and fungal cultures: Candida albicans ATCC 60193, Candida glabrata, Candida krusei, Candida kefyr ATCC 8614, Candida tropicalis ATCC 8302, Candida parapsilosis. Results showed that the new compounds were significantly more effective as antimicrobial agents than initial preparation ethacridine. Ethacridine derivatives were not only effective against numerous gram-positive and some gram-negative bacteria, but the spectrum of action has been discovered against fungi. Minimal fungistatic concentration varies in the range 10.0-750 microg/mL and antibacterial concentration is in the range 62.5-1000 microg/mL. Compound 2a having nitrofuryl substituent in the fifth position of tiazolidine cycle was the most active of synthesized ethacridine compounds. The obtained results gave the opportunity to separate the perspective group of potential antiinfective compounds.

Kinetic and mechanistic analyses of new classes of inhibitors of two-component signal transduction systems using a coupled assay containing HpkA-DrrA from Thermotoga maritima

Two-component signal transduction systems (TCSs) play fundamental roles in bacterial survival and pathogenesis and have been proposed as targets for the development of novel classes of antibiotics. A new coupled assay was developed and applied to analyse the kinetic mechanisms of three new kinds of inhibitors of TCS function. The assay exploits the biochemical properties of the cognate HpkA-DrrA histidine kinase-response regulator pair from Thermotoga maritima and allows multiple turnovers of HpkA, linear formation of phosphorylated DrrA, and Michaelis-Menten analysis of inhibitors. The assay was validated in several ways, including confirmation of competitive inhibition by adenosine 5'-beta,gamma-imidotriphosphate (AMP-PNP). The coupled assay, autophosphorylation and chemical cross-linking were used to determine the mechanisms by which several compounds inhibit TCS function. A cyanoacetoacetamide showed non-competitive inhibition with respect to ATP concentration in the coupled assay. The cyanoacetoacetamide also inhibited autophosphorylation of histidine kinases from other bacteria, indicating that the coupled assay could detect general inhibitors of histidine kinase function. Inhibition of HpkA autophosphorylation by this compound was probably caused by aggregation of HpkA, consistent with a previous model for other hydrophobic compounds. In contrast, ethodin was a potent inhibitor of the combined assay, did not inhibit HpkA autophosphorylation, but still led to aggregation of HpkA. These data suggest that ethodin bound to the HpkA kinase and inhibited transfer of the phosphoryl group to DrrA. A peptide corresponding to the phosphorylation site of DrrA appeared to inhibit TCS function by a mechanism similar to that of ethodin, except that autophosphorylation was inhibited at high peptide concentrations. The latter mechanism of inhibition of TCS function is unusual and its analysis demonstrates the utility of these approaches to the kinetic analyses of additional new classes of inhibitors of TCS function.

A rapid direct telomerase assay method using 96-well streptavidin plates

We have developed a high-throughput direct assay methodfor the assay of telomerase activity that improves on previous direct telomerase assays in two ways that allow larger numbers of samples to be conveniently processed: (i) 96-well streptavidin coated plates are used to bind and wash biotinylated primer extension products from the telomerase assay, as opposed to tubes containing streptavidin-coated magnetic beads; and (ii) storage phosphor-imagery is used instead of film autoradiography to detect telomerase products after being washed and released from the streptavidin-derivatized matrix. This method improves on previous direct assay methods using magnetic beads by allowing larger numbers of samples to be conveniently assayed. Also, the total activity of the radiolabeled nucleotides used in this procedure is significantly lower than that used in standard direct telomerase assays, lowering costs and exposure to radioactivity. We have validated the assay by repeating, in triplicate, the IC50 determination of rivanol, our previously identified telomerase inhibitor.

Synergistic bactericidal effects of acrinol and tetracycline against Pseudomonas aeruginosa

Combined treatment of acrinol (Ac) and tetracycline hydrochloride (Tc) against Pseudomonas aeruginosa strains isolated from clinical specimens synergistically increased the bactericidal effect. The minimum bactericidal concentration (MBC) of Ac against P. aeruginosa strain no. 985 was 200 microg/ml, while the MBC of Ac against strains no. 47 and no. 783 was above 800 microg/ml for each. The MBC of Tc was above 400 microg/ml against each of the tested strains. However, simultaneous treatment with 25 microg/ml Ac and 200 microg/ml Tc against P. aeruginosa strain no. 985 decreased the viable cell number from 107 cfu/ml to <10 cfu/ml within 24 h, while a higher concentration of Tc (400 microg/ml) with Ac (25 microg/ml) reduced the viable cell number to <10 cfu/ml within 8 h. A similar synergistic bactericidal effect of Ac and Tc was observed in strains no. 47 and no. 783 by treatment with 200 microg/ml Ac and 200 microg/ml or 400 microg/ml Tc. The degree of bactericidal effect against P. aeruginosa was proportional to the concentration of Tc under the condition of a constant concentration of Ac. Furthermore, Ac-treated cells of strain no. 47 were killed by a following Tc treatment, but cells pretreated with Tc did not show such a sensitivity to Ac. To induce the synergistic effect of Ac and Tc, Ac must be applied to P. aeruginosa before or at the same time as Tc.

Comparative study of cervical laminar tents prior to extra-amniotic injection of ethacridine lactate (Rivanol) and a condom-nelathon catheter method for second-trimester pregnancy interruption in Vietnam

OBJECTIVE

To determine whether the regimen for termination of second-trimester pregnancies using laminaria tents 12-24 h prior to extra-amniotic ethacridine lactate (Rivanol) instillation, is more effective in shortening the insertion-expulsion interval than the presently used method of abortion induction by a condom/Nelathon catheter.

DESIGN

A prospective randomised comparative study was performed at Uong Bi General Hospital in Quang Ninh Province, Vietnam, on 91 women undergoing pregnancy termination in the second trimester.

INTERVENTIONS

The subjects were randomly allocated to 2 treatment groups, receiving either the Nelathon catheter-condom method (n = 50) or by insertion of a laminaria tent into the cervical canal for preinduction, 13-29 h before extra-amniotic instillation of ethacridine lactate (n = 34). Seven subjects were not pretreated with the laminaria tent.

MAIN OUTCOME MEASURES

The insertion-expulsion intervals and the incidence of side effects were assessed.

RESULTS

The mean insertion-expulsion interval in the 2 groups was not significantly different (mean 27.5 +/- 16.1 and 26.4 +/- 16.4 h, respectively), calculating the insertion-expulsion interval from the start of active treatment, i.e. from the instillation of Rivanol or insertion of the Nelathon catheter and condom, until expulsion of the fetus.

CONCLUSIONS

The laminaria-Rivanol method for pregnancy interruption is not more advantageous than the existing Nelathon catheter-condom method. Simple, successful and cost-effective methods in achieving second-trimester abortion in the Vietnamese context have therefore to be identified and tested.

Ethodin: pharmacological evidence of the interaction between smooth muscle and mast cells in the myometrium

Ethodin has been used to induce labor through a mechanism that does not involve the estrogen-preparatory process being postulated as necessary for ensuring the events in a normal labor. The cellular mechanisms involved in that process are unknown. We used an isolated organ bath preparation for mouse uterine horns and a primary culture of mouse myometrial smooth muscle cells to analyze the cellular mechanisms involved in the contractile action of this drug in the myometrium. Ethodin at a concentration of 10 microM and Compound 48/80 (1 microg/ml) evoked contractions of uterine horns in an isolated organ bath preparation. Uterine contractile responses showed a transient increase in contractile tension that lasted 2 to 3 min. Tachyphylaxis was observed after four or five successive stimuli, which consisted in additions and washings of the drug at an interval of 10 min. The primary smooth muscle mouse myometrium cells contained a high proportion of relaxed cells that varied widely in length (5-160 microm). Cell lengths decreased in response to the application of serotonin (10 microM) and oxytocin (0.1 microM) but were not affected after the addition of ethodin (10 microM). However, the cells contracted after a purified fraction of mast cells that had been degranulated by the action of the drug ethodin, which was added to the culture medium. These results provide some evidence related to the mechanism of myometrial contractile action of ethodin and support the hypothesis that mast cells may be involved in the regulation of myometrium contractility.

Analysis of poly(ADP-ribose) glycohydrolase activity in nuclear extracts from mammalian cells

We have analysed poly(ADP-ribose) glycohydrolase, the enzyme responsible for in vivo degradation of ADP-ribose polymers, by means of a biochemical assay based on the capacity of the enzyme to use a synthetic 32P-labelled polymer as a substrate. The visualization of the reaction has been achieved by separation of poly and mono(ADP-ribose) by thin-layer chromatography followed by autoradiography, whereas polymer hydrolysis has been quantified by counting the spots corresponding to poly and mono(ADP-ribose). By addition of the enzyme inhibitor ethacridine to the reaction mixture, we have confirmed the specificity of the procedure we have developed. The protocol has been applied to study the specific activity of glycohydrolase in nuclear extracts from different mammalian cell lines and to an apoptotic experimental system, namely HL60 cells treated with etoposide. We have observed the activation of the enzyme after a two-hour drug treatment, that is concomitant with the activation of poly(ADP-ribose) polymerase, the enzyme which synthesizes the polymer. These data suggest a precise regulation of ADP-ribosylation process during cell death by apoptosis.

On the mechanism of action of ethodin in inducing myometrium contractions

1. Ethodin (Rivanol, 6,9-diamino-2-oxyethyl acridine lactate), has been described as an effective drug to induce uterine contractions similar to those in a physiologic labor in still-birth with uterine inertia. We investigate the mechanisms involved in the effect of this compound in contracting the smooth-muscle cells of the myometrium to improve our understanding of the processes involved in the onset of labor. 2. We conclude that the contractile effect of ethodin is mediated through the activation of uterine mast cells that release mediators able to contract the myometrium.

[Futile intra-amnion Rivanol administration and prostaglandin labor induction in uterus unicornis unicollis with a noncommunicating right-sided horn]

We report on the futile use of labour-inducing agents in a patient with a Mullerian duct abnormality. In the 20th week of gestation, foetal death had been diagnosed in the rudimentary right horn. It is suggested that induction as well as continuation of effective contractions depends on the intact uterus (cervix, lower uterine segment, and corpus).

[Synergism on the bactericidal effect of gentian violet (Gv) and acrinol (Ac) against Pseudomonas aeruginosa]

The MBCs of Ac against P. aeruginosa (7 strains) isolated from infected skin lesions of patients were more than 6400 micrograms/ml, and those of Gv were more than 1600 micrograms/ml. When either Ac or Gv was used independently, these dyes did not have the bactericidal effect of P. aeruginosa. When Gv was used in combination with Ac, predominantly synergism on the bactericidal effect of Ac and Gv against P. aeruginosa was observed. The MBCs of an Ac-Gv cocktail were between 100 micrograms/ml and 225 micrograms/ml. We have previously reported that Gv possessed significantly a bactericidal effect to MRSA isolated from clinical specimens. Therefore, these results suggested that a combination treatment by an Ac-Gv cocktail may be one of the useful drugs for the MRSA and P. aeruginosa mixed infection on the skin lesions which is frequently observed clinically.

Effects of vesicular acetylcholine uptake blockers on frequency augmentation-potentiation in frog neuromuscular transmission

Vesamicol inhibits the vesicular loading of acetylcholine molecules. The effects of vesamicol and similarly acting compounds on neuromuscular transmission in frogs were investigated to determine whether these inhibitors-inhibit the frequency augmentation-potentiation of transmitter release. Various vesicular acetylcholine transport blockers suppressed the stimulation frequency-related release parameter, k, in a dose-dependent manner. Artane, cetiedil, chloroquine, ethodin, quinacrine, vesamicol and its benzyl-analogue, 2-(4-benzylpiperidino)cyclohexanol, had strong effects, while those of aminacrine, chlorpromazine, fluphenazine, imipramine, pyrilamine and thioridazine were weak. A significant correlation was observed between the biochemically reported values of IC50 and the electrophysiological inhibitory potencies on k at 20 microM. Contrary to expectations from the biochemical data, however, vesamicol and its benzyl-analogue showed equipotent inhibitory actions on the electrophysiological frequency augmentation-potentiation relation. Low sensitivity and low selectivity of the frequency augmentation-potentiation for vesamicol and its benzyl-analogue lead us to conclude that the vesicular acetylcholine transporter is not the site of the electrophysiological action of vesamicol and similarly acting chemicals.

[The virological safety and bacterial sterility of a method for fractionating blood plasma proteins with rivanol]

The bacterial and virological safety of the method of rivanol fractionation of blood plasma proteins has been evaluated in experiments with samples of donor blood plasma mixed with the suspension of viruses and Escherichia coli used as models. The bacteriostatic action of rivanol and the elimination of bacteriophage and influenza virus from the end product at the stages of rivanol precipitation and adsorption on carbon have been established.

Studies on protein poly(ADP-ribosylation) using high resolution gel electrophoresis

Analysis of poly(ADP-ribose) synthesized in cellular lysates or in isolated nuclei on 100-cm-long thin gels of 20% polyacrylamide, 2.5 M urea permits determination of the exact size of poly(ADP-ribose) molecules using labeled oligonucleotides as molecular weight markers. The size and concentration of poly(ADP-ribose) molecules increase at time intervals during its synthesis. Differences in the concentration of poly(ADP-ribose) size classes among cell lines are also shown. Inhibition of poly(ADP-ribose) degradation by ethacridine that directly interacts with the polymer and inhibits its hydrolysis by poly(ADP-ribose) glycohydrolase shows a dramatic increase in both polymer size and concentration. Use of alkaline conditions for the hydrolysis of poly(ADP-ribose)-protein linkages reveals a specific shortening of all size classes of poly(ADP-ribose) compared with its size in preparations obtained by extensive digestion of nuclei with nucleases, RNases, and proteases.

Inhibition of carcinogen-inducible DNA amplification in a simian virus 40-transformed hamster cell line by ethacridine or ethanol

DNA amplification as a mechanism to increase gene expression has been established as a cause of cytotoxic drug resistance and appears to play a role in tumor cell progression. In order to investigate factors which control the process of DNA amplification we have been using a simian virus 40 (SV40)-transformed Chinese hamster cell line (CO60) as a model system. This cell line can be induced to amplify integrated viral DNA with a variety of agents. In this report the following is shown. (a) Addition of ethacridine, an intercalative compound, or ethanol to the culture media inhibits amplification induced by the alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine or by gamma-irradiation in a dose-dependent fashion. In the case of N-methyl-N'-nitro-N-nitrosoguanidine induction (50 microM), the highest concentrations of ethacridine (40 microM) or ethanol (2% v/v) tested reduced SV40 amplification from about 20-fold to less than 2-fold. (b) Neither substance induces significant amplification when applied alone over a wide range of concentrations (0.01-20 microM ethacridine; 0.001-2% ethanol). (c) Significant inhibition of amplification is achieved with nearly nontoxic concentrations of both substances (10 microM; 1%), (d) Without direct interference with the inducer. It is concluded that ethacridine or ethanol treatment uncouples the toxic effects of an alkylating agent or ionizing radiation from their ability to induce amplification in CO60 cells.

The evaluation of genotoxic activities of disinfectants and their metabolites by umu test

The genotoxic potential of 6 disinfectants and their 9 metabolites was investigated by umu test. In the tested disinfectants, glutaraldehyde showed positive genotoxicity independent of metabolic activation system and acrinol was positive only in the presence of S9 mixture. Alkylaminoethylglycine, benzalkonium chloride, chlorhexidine digluconate and methylrosaniline chloride were negative in the presence or absence of S9 mixture. In some metabolites of benzalkonium chloride, chlorhexidine digluconate or glutaraldehyde, only pyrogallol showed positive genotoxicity in the absence of S9 mixture and the activity was not affected by the metabolic activation system. Aniline, p-chloroacetoanilide, p-chloroaniline, p-chlorophenol, decabutyldimethylamine, glutaric acid, phenol and pyrocatechol did not induce umu gene expression independently of the presence of S9 mixture. The results in the umu test of these compounds were compared with their findings in the liquid rec-assay and Ames test. The umu test is a more useful and simplified method for the detection of genotoxicity of the compounds with killing effects on tester bacteria.

Antiseptic and antibiotic resistance plasmid in Staphylococcus aureus that possesses ability to confer chlorhexidine and acrinol resistance

Plasmid pSAJ1 from a methicillin- and gentamicin-resistant strain of Staphylococcus aureus had am molecular size of 50 kilobases and conferred resistance not only to kanamycin, gentamicin, tobramycin, amikacin, benzalkonium chloride, acriflavin, and ethidium bromide but also to chlorhexidine. In addition, the cloned antiseptic resistance gene(s) manifested acrinol resistance in Escherichia coli.

Lack of coagulation defects after the intraamniotic instillation of ethacridine (Rivanol) for second trimester abortion

Second trimester abortion was induced by the intraamniotic infusion of ethacridine. Coagulation studies revealed no change in 10 cases. It is felt that the intraamniotic use of ethacridine is probably safe.

[Radiolysis and variation of anti-microbial activity of gamma-irradiated acrinol aqueous solution on radiosterilization]

The investigations about the radiolysis materials and their quantities, and, anti-microbial activities of gamma-irradiated (in the ranges of 0.516-2.064 kC/kg (2-8 MR] acrinol on liquid dosage form have been carried out to study the application of radiosterilization. About nine components were found as radiolysis materials. Most of them were also found in the UV-irradiated of Fenton's reagent-treated acrinol solution. Increase of anti-microbial activity was observed with gamma-irradiated acrinol solutions, but this phenomenon was not long-lasting. The micro-organism such as Pseudomonas aeruginosa or Staphylococcus aureus that infect at the lips of wound are highly sensitive to the gamma-irradiation. They are almost sterilized by the irradiation of 10 kGy (1.0 Mrad). At a low acrinol concentration, the decomposition rate of acrinol by the irradiation was relatively high. When 1.0% of acrinol solution was irradiated at a dose of 10 kGy (1.0 Mrad), the decomposition of the drug was less than 2% and the variation of anti-microbial activity was negligible.

The effects of serum, lithium, ethacrynic acid, and a low external concentration of potassium on specific [3H]-ouabain binding to human lymphocytes after incubation for 3 days

We have quantified specific [3H]-ouabain binding sites in normal human lymphocytes, and have measured the changes in the numbers of those sites which occur in response to various stimuli. We have confirmed previous findings that incubation for 72 h in the presence of fetal calf serum causes an increase in [3H]-ouabain binding, and that this does not occur if the cells are incubated in fetal calf serum which has first been dialysed. During incubation of the lymphocytes for 3 days in the presence of dialysed fetal calf serum each of the following stimuli caused an increase in specific [3H]-ouabain binding: addition of ethacrynic acid (1 mumol l-1), addition of lithium (1 mmol l-1), and reduction of the external potassium concentration (to 0.75 mmol l-1). By analogy with the similar results in HeLa cells reported by others, we suggest that the increase in [3H]-ouabain binding may, in the case of ethacrynic acid and the reduction of the external potassium concentration, be initiated by an increase in the intracellular sodium concentration. The mechanisms whereby fetal calf serum and lithium cause an increase in [3H]-ouabain binding are not clear.

Mutagenic activity of acrinol in Salmonella typhimurium

Acrinol, which is used as a disinfectant and an abortifacient in several countries, was tested for mutagenicity by the Ames test system. After incubation with a rat-liver S9 microsomal preparation, acrinol showed potent mutagenicity for Salmonella typhimurium strains TA98 and TA100, although it had no direct mutagenicity for the microorganisms.

Effect of DNA intercalators on poly(ADP-ribose) glycohydrolase activity

Proflavine, ethacridine (2-ethoxy-6,9-acridine diamine), ellipticine, daunomycin and Tilorone R10,556 DA (2,7-bis(piperidinobutyryl)-9H-fluoren-9-one) inhibit poly(ADP-ribose) glycohydrolase activity. The Ki values for proflavine and Tilorone R10,556 DA are 36 microM and 7.3 microM, respectively. The inhibition by intercalators is relieved by DNA but not by DNA-histone complexes. On the contrary, DNA-histone complexes increase the inhibition of some intercalators. Ethidium bromide is not inhibitory by itself. However, in the presence of DNA-histone complexes it strongly inhibits the enzyme activity. m-AMSA (4'-(9-acridinylamino)methanesulphon-m-anisidide) and chloroquine have no effect on the enzyme activity, even in the presence of DNA-histone complexes.

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.

Uterine activity and placental histology in abortion at mid-trimester by rivanol and catheter

Artificial abortions were performed on 7 patients during mid-pregnancy by intra-uterine instillation of 0.1% rivanol and catheters. The changes in uterine contractility during the treatment were monitored continuously by intra-amniotic pressure recording. Uterine activity developed a gradual but steady increase and abortion was completed within 22 to 47 hours. A significant increase in uterine contractility started after a lag of several hours. Neither hypertonus nor hyperactivity was noted during the treatment. The fetus was delivered unaffected in all cases. The placentas delivered showed normal histological integrity, and an autoradiographic study established the viability of trophoblasts. These results suggest that the abortive effect of rivanol and catheter on the uterus and placenta is different from that induced by other chemicals.

Cytotoxicity of an 125I-labeled DNA-binding compound that induces double-stranded DNA breaks

[125I]Iodorivanol (6,9-diamino-2-ethoxy-5-[125]iodoacridine) has been prepared by direct iodination of rivanol (6.9-diamino-2-ethoxyacridine). In vitro binding of [125I]iodorivanol to PM2 DNA resulted in induction of double-stranded DNA breaks following decay of the 125I atom, presumably in the same way as decay of 125I atoms in 125I-labeled DNA causes double-stranded DNA breaks. Treatment of mouse L-cell cultures with [125I]iodorivanol resulted in a cell kill, the extent of which was dependent on the 125I specific activity and the duration of exposure. A clonogenic assay was used to quantitate cell kill. It was concluded that at least some of the [125I]iodorivanol in the culture medium was taken up by the cells, transported to the nucleus, and bound to DNA and that subsequent decay of the 125I atoms induced double-stranded DNA breaks in the genome, with consequent loss of viability. 125I-labeled DNA-binding compounds are suggested as a novel class of cytotoxic agents.

Side products of routine plasma fractionation. I. Serum cholinesterase (EC 3.1.1.8)

Cholinesterase (EC 3.1.1.8) for intravenous use has been obtained from fraction IV, a by-product of ehtanol fractionation. A four-step procedure has been developed associating precipitation by Rivanol and PEG 4000 with chromatography on DEAE-cellulose. The yield corresponds to 30--35% of the activity found in fraction IV. Vials containing 5000 U of CHE stabilized by 2.5% albumin have been prepared. The pyrogen-free product is well tolerated in the human.

A new selective medium for the isolation of Listeria monocytogenes

A new selective medium for the isolation of Listeria monocytogenes (Lm), is described. The medium contained propolis, nalidixic acid, polymyxin B and rivanol as selective substances. The new medium (propolis-agar) was compared with two other selective media and one nonselective medium. No inhibitory effect was found on the 6 strains of Lm tested, and Lm was easily isolated from a mixture of Lm and contaminating bacteria. The selective effect was better than for the two other selective media tested.