-
Cytometry. Part a : the Journal of the... Jun 2020Briefly depicted are the publications in CYTOMETRY that received the highest frequency of citations. Among them are seminal papers describing application of...
Briefly depicted are the publications in CYTOMETRY that received the highest frequency of citations. Among them are seminal papers describing application of metachromatic fluorochrome acridine orange to differentially stain DNA versus RNA or to analyze susceptibility of DNA in situ to denaturation; both features being markers of different sections of the cell cycle including identification of noncycling quiescent cells. The papers reviewing detection of cyclins D1, E, A or B1, each in relation to cell cycle phase, were also among the highly cited ones. The highest citation rates received publications describing development of the TUNEL methodology to detect apoptotic DNA fragmentation, and more recently expression of ϒH2AX to reveal DNA damage. © 2020 International Society for Advancement of Cytometry.
Topics: Acridine Orange; Cell Cycle; DNA; Flow Cytometry; Fluorescent Dyes
PubMed: 32511890
DOI: 10.1002/cyto.a.24043 -
Biochimica Et Biophysica Acta.... Jun 2023The efficiency of methylene blue (MB) and acridine orange (AO) for photodynamic therapy (PDT) is increased if encapsulated in liposomes. In this paper we determine the...
The efficiency of methylene blue (MB) and acridine orange (AO) for photodynamic therapy (PDT) is increased if encapsulated in liposomes. In this paper we determine the molecular-level interactions between MB or AO and mixed monolayers of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (DPPG) and cholesterol (CHOL) using surface pressure isotherms and polarization-modulated infrared reflection absorption spectroscopy (PM-IRRAS). To increase liposome stability, the effects from adding the surfactants Span® 80 and sodium cholate were also studied. Both MB and AO induce an expansion in the mixed monolayer, but this expansion is less significant in the presence of either Span® 80 or sodium cholate. The action of AO and MB occurred via coupling with phosphate groups of DPPC or DPPG. However, the levels of chain ordering and hydration of carbonyl and phosphate in headgroups depended on the photosensitizer and on the presence of Span® 80 or sodium cholate. From the PM-IRRAS spectra, we inferred that incorporation of MB and AO increased hydration of the monolayer headgroup, except for the case of the monolayer containing sodium cholate. This variability in behaviour offers an opportunity to tune the incorporation of AO and MB into liposomes which could be exploited in the release necessary for PDT.
Topics: Methylene Blue; Acridine Orange; Liposomes; Sodium Cholate; Spectrophotometry, Infrared
PubMed: 37031871
DOI: 10.1016/j.bbamem.2023.184156 -
International Journal of Molecular... Jan 2023Swim-up selected human sperm were incubated with 7 ng F-neuroprostanes (F-NeuroPs) for 2 and 4 h. Sperm motility and membrane mitochondrial potential (MMP) were...
Swim-up selected human sperm were incubated with 7 ng F-neuroprostanes (F-NeuroPs) for 2 and 4 h. Sperm motility and membrane mitochondrial potential (MMP) were evaluated. The percentage of reacted acrosome was assessed by pisum sativum agglutinin (PSA). Chromatin integrity was detected using the acridine orange (AO) assay and localization of the ryanodine receptor was performed by immunofluorescence analysis. Sperm progressive motility ( = 0.02) and the percentage of sperm showing a strong MMP signal ( = 0.012) significantly increased after 2 h F-NeuroP incubation compared to control samples. The AO assay did not show differences in the percentage of sperm with dsDNA between treated or control samples. Meanwhile, a significantly higher number of sperm with reacted acrosomes was highlighted by PSA localization after 4 h F-NeuroP incubation. Finally, using an anti-ryanodine antibody, the immunofluorescence signal was differentially distributed at 2 and 4 h: a strong signal was evident in the midpiece and postacrosomal sheath (70% of sperm) at 2 h, whereas a dotted one appeared at 4 h (53% of sperm). A defined concentration of F-NeuroPs in seminal fluid may induce sperm capacitation via channel ions present in sperm cells, representing an aid during in vitro sperm preparation that may increase the positive outcome of assisted fertilization.
Topics: Humans; Male; Neuroprostanes; Sperm Motility; Seeds; Spermatozoa; Acrosome; Acridine Orange
PubMed: 36674450
DOI: 10.3390/ijms24020935 -
BioMed Research International 2019Musculoskeletal sarcomas are rare and aggressive human malignancies affecting bones and soft tissues with severe consequences, in terms of both morbidity and mortality....
Musculoskeletal sarcomas are rare and aggressive human malignancies affecting bones and soft tissues with severe consequences, in terms of both morbidity and mortality. An innovative technique that combines photodynamic surgery (PDS) and therapy (PDT) with acridine orange has been recently suggested, showing promising results. However, due to the low incidence of sarcoma in humans, this procedure has been attempted only in pilot studies and stronger evidence is needed. Naturally occurring tumors in cats are well-established and advantageous models for human cancers. Feline injection-site sarcoma (FISS) shares with human musculoskeletal sarcomas a mesenchymal origin and an aggressive behavior with a high relapse rate. Furthermore, wide surgical excision is not always possible due to the size and site of development. We assessed the feasibility and the effectiveness of PDS and PDT with acridine orange to prevent FISS recurrence by treating a short case series of cats. For PDS, the surgical field was irrigated with an acridine orange solution and exposed to UV light to enlighten the residual tumor tissue, and the resultant fluorescent areas were trimmed. For PDT, before wound closure, the field was again irrigated with acridine orange solution and exposed to visible light to get the antitumoral cytocidal effect. The procedure was easy to perform and well tolerated, we did not observe any major complications, and all the surgical resection margins were free of disease. Finally, at follow-up, all treated patients did not show evidence of tumor recurrence and had a significantly higher event-free survival rate in respect to a control group treated only by surgery. In conclusion, by this study we demonstrated that, in FISS, PDS and PDT with acridine orange may improve local tumor control, granting a better outcome, and we laid the foundation to validate its effectiveness for the treatment of human musculoskeletal sarcomas.
Topics: Acridine Orange; Animals; Cats; Female; Humans; Male; Muscle Neoplasms; Photochemotherapy; Sarcoma
PubMed: 31360726
DOI: 10.1155/2019/8275935 -
Molecular Neurodegeneration Dec 2022Microglia regulate the response to injury and disease in the brain and spinal cord. In white matter diseases microglia may cause demyelination. However, how microglia...
BACKGROUND
Microglia regulate the response to injury and disease in the brain and spinal cord. In white matter diseases microglia may cause demyelination. However, how microglia respond and regulate demyelination is not fully understood.
METHODS
To understand how microglia respond during demyelination, we fed mice cuprizone-a potent demyelinating agent-and assessed the dynamics of genetically fate-mapped microglia. We then used single-cell RNA sequencing to identify and track the microglial subpopulations that arise during demyelination. To understand how microglia contribute to the clearance of dead oligodendrocytes, we ablated microglia starting at the peak of cuprizone-induced cell death and used the viability dye acridine orange to monitor apoptotic and lytic cell morphologies after microglial ablation. Lastly, we treated serum-free primary microglial cultures to model distinct aspects of cuprizone-induced demyelination and assessed the response.
RESULTS
The cuprizone diet generated a robust microglial response by week 4 of the diet. Single-cell RNA sequencing at this time point revealed the presence of several cuprizone-associated microglia (CAM) clusters. These clusters expressed a transcriptomic signature indicative of cytokine regulation and reactive oxygen species production with altered lysosomal and metabolic changes consistent with ongoing phagocytosis. Using acridine orange to monitor apoptotic and lytic cell death after microglial ablation, we found that microglia preferentially phagocytose lytic carcasses. In culture, microglia exposed to lytic carcasses partially recapitulated the CAM state, suggesting that phagocytosis contributes to this distinct microglial state during cuprizone demyelination.
CONCLUSIONS
Microglia serve multiple roles during demyelination, yet their transcriptomic state resembles other neurodegenerative conditions. The phagocytosis of cellular debris is likely a universal cause for a common neurodegenerative microglial state.
Topics: Animals; Mice; Cuprizone; Microglia; Demyelinating Diseases; Transcriptome; Acridine Orange; Mice, Inbred C57BL; Disease Models, Animal
PubMed: 36514132
DOI: 10.1186/s13024-022-00584-2 -
Nucleic Acids Research Apr 2018The ordered structure of UV chromophores in DNA resembles photosynthetic light-harvesting complexes in which quantum coherence effects play a major role in highly...
The ordered structure of UV chromophores in DNA resembles photosynthetic light-harvesting complexes in which quantum coherence effects play a major role in highly efficient directional energy transfer. The possible role of coherent excitons in energy transport in DNA remains debated. Meanwhile, energy transport properties are greatly important for understanding the mechanisms of photochemical reactions in cellular DNA and for DNA-based artificial nanostructures. Here, we studied energy transfer in DNA complexes formed with silver nanoclusters and with intercalating dye (acridine orange). Steady-state fluorescence measurements with two DNA templates (15-mer DNA duplex and calf thymus DNA) showed that excitation energy can be transferred to the clusters from 21 and 28 nucleobases, respectively. This differed from the DNA-acridine orange complex for which energy transfer took place from four neighboring bases only. Fluorescence up-conversion measurements showed that the energy transfer took place within 100 fs. The efficient energy transport in the Ag-DNA complexes suggests an excitonic mechanism for the transfer, such that the excitation is delocalized over at least four and seven stacked bases, respectively, in one strand of the duplexes stabilizing the clusters. This result demonstrates that the exciton delocalization length in some DNA structures may not be limited to just two bases.
Topics: Acridine Orange; Animals; Cattle; DNA; Energy Transfer; Fluorescence; Nanostructures; Nucleic Acid Conformation; Photosynthesis; Quantum Theory; Silver; Ultraviolet Rays
PubMed: 29186575
DOI: 10.1093/nar/gkx1185 -
International Orthopaedics Jun 2014The sensitivity of Gram staining is known to be suboptimal for the diagnosis of native joint septic arthritis. We lack information about the accuracy of Gram compared to... (Comparative Study)
Comparative Study
PURPOSE
The sensitivity of Gram staining is known to be suboptimal for the diagnosis of native joint septic arthritis. We lack information about the accuracy of Gram compared to other microscopic staining techniques for predicting infection in different patient populations.
METHODS
This was a cohort study with cost evaluations at the Orthopaedic Service of Geneva University Hospitals (January 1996-October 2012).
RESULTS
Among 500 episodes of arthritis (196 with immunosuppression, 227 with underlying arthroplasties and 69 with gout or other crystals in synovial fluid), Gram staining revealed pathogens in 146 episodes (146/500, 29 %) or in 146 of the 400 culture-positive episodes (37 %). Correlation between the Gram and acridine staining of the same sample was good (Spearman 0.85). Overall, the sensitivity, specificity, positive predictive value and negative predictive value of Gram stain for rapid diagnosis of septic arthritis was 0.37, 0.99, 0.99 and 0.28, respectively, compared to microbiological cultures. Quite similar values were recorded across the different patient subpopulations, in particular for sensitivity values that were 0.33 for patients with prosthetic joint infections, 0.40 for immunosuppressed patients, 0.36 for patients under antibiotic administration and 0.52 for patients with concomitant crystalline disease.
CONCLUSIONS
The sensitivity of Gram or acridine orange staining for a rapid diagnosis of episodes of septic arthritis is suboptimal compared to microbiological culture, regardless of underlying conditions, immunosuppression or antibiotic therapy. The sensitivity in the presence of synovial fluid crystals is moderate. Acridine orange and Gram stains are equivalent.
Topics: Acridine Orange; Arthritis, Infectious; Cohort Studies; Female; Fluorescent Dyes; Gentian Violet; Humans; Male; Phenazines; Predictive Value of Tests; Sensitivity and Specificity; Staining and Labeling; Synovial Fluid
PubMed: 24496757
DOI: 10.1007/s00264-014-2284-3 -
The Canadian Veterinary Journal = La... May 2019Canine intranasal carcinomas are almost always malignant. Surgery alone often results in rapid tumor regrowth. Radiotherapy is the treatment of choice for dogs with...
Canine intranasal carcinomas are almost always malignant. Surgery alone often results in rapid tumor regrowth. Radiotherapy is the treatment of choice for dogs with intranasal tumors. Here, we retrospectively assessed treatment of intranasal carcinoma by marginal tumor resection followed by intraoperative acridine orange (AO) photodynamic therapy (PDT) and cribriform plate electron-beam intraoperative radiotherapy (IORT). Fourteen canine cases were assessed, 12 of which had stage I tumors, one with stage III, and one with stage IV. Recurrence was detected in 8, with a median recurrence from the time of treatment of 6 months (range: 3 to 16 months). The median progression-free survival time and overall survival time after treatment were 13 and 22 months, respectively. Adverse events were mild. Marginal tumor resection followed by intraoperative AO-PDT and cribriform plate electron-beam IORT may increase the tumor control time in dogs with marginally resectable intranasal malignant tumors beyond that incurred by surgery alone.
Topics: Acridine Orange; Animals; Combined Modality Therapy; Dog Diseases; Dogs; Electrons; Intraoperative Care; Neoplasm Recurrence, Local; Photochemotherapy; Retrospective Studies
PubMed: 31080264
DOI: No ID Found -
Journal of Andrology 1992The relationship between thiol-disulfide status and acridine orange fluorescence of testicular, epididymal, and ejaculated spermatozoa in several mammalian species was...
The relationship between thiol-disulfide status and acridine orange fluorescence of testicular, epididymal, and ejaculated spermatozoa in several mammalian species was investigated. Spermatozoa were fixed with acetic alcohol, stained with acridine orange, and examined with a fluorescence microscope. The majority of the nuclei of testicular spermatozoa of the hamster, mouse, and rabbit exhibited red acridine orange fluorescence. The proportion of sperm nuclei with red acridine orange fluorescence decreased as the spermatozoa descended the epididymis. Red acridine orange fluorescence was replaced by green acridine orange fluorescence. The site in the epididymis where 100% of the nuclei exhibited green fluorescence was the distal caput in the mouse, the corpus in the rabbit, and the proximal cauda in the hamster. In semen samples from men with proven fertility, normal semen parameters, or both, about 60% to 90% of the nuclei exhibited green acridine orange fluorescence. The proportion of sperm nuclei exhibiting green acridine orange fluorescence was higher in the spermatozoa pellet (containing highly motile spermatozoa) obtained by centrifugation through a Percoll gradient. From experiments using disulfide-reducing, thiol-oxidizing and thiol-detecting agents, we concluded that sperm nuclei fluoresce red when they are treated with acid while their DNA-associated protamines are poor in disulfides. Under such conditions, DNA is vulnerable to denaturation. Acridine orange binds to denatured (single-stranded) DNA as aggregates and emits red fluorescence. In contrast, when sperm nuclei are treated with acid while their DNA-associated protamines are rich in disulfides, DNA is resistant to denaturation. Acridine orange binds to native (double-stranded) DNA as a monomer and emits green fluorescence.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: Acridine Orange; Animals; Bridged Bicyclo Compounds; Cell Nucleus; Cricetinae; DNA; Disulfides; Epididymis; Fluorescent Dyes; Humans; Male; Mesocricetus; Mice; Mice, Inbred C57BL; Microscopy, Electron; Protamines; Rabbits; Spermatozoa; Sulfhydryl Compounds; Testis
PubMed: 1399837
DOI: No ID Found -
Cytometry. Part a : the Journal of the... Aug 2014Acidic vesicles can be imaged and tracked in live cells after staining with several low molecular weight fluorescent probes, or with fluorescently labeled proteins....
Acidic vesicles can be imaged and tracked in live cells after staining with several low molecular weight fluorescent probes, or with fluorescently labeled proteins. Three fluorescent dyes, acridine orange, LysoTracker Red DND-99, and quinacrine, were evaluated as acidic vesicle tracers for confocal fluorescence imaging and quantitative analysis. The stability of fluorescent signals, achievable image contrast, and phototoxicity were taken into consideration. The three tested tracers exhibit different advantages and pose different problems in imaging experiments. Acridine orange makes it possible to distinguish acidic vesicles with different internal pH but is fairly phototoxic and can cause spectacular bursts of the dye-loaded vesicles. LysoTracker Red is less phototoxic but its rapid photobleaching limits the range of useful applications considerably. We demonstrate that quinacrine is most suitable for long-term imaging when a high number of frames is required. This capacity made it possible to trace acidic vesicles for several hours, during a process of drug-induced apoptosis. An ability to record the behavior of acidic vesicles over such long periods opens a possibility to study processes like autophagy or long-term effects of drugs on endocytosis and exocytosis.
Topics: Acids; Acridine Orange; Amines; Apoptosis; Biological Transport; Camptothecin; Cell Line; Cell Tracking; Cytoplasmic Vesicles; Fluorescence; Fluorescent Dyes; Humans; Imaging, Three-Dimensional; Quinacrine; Time Factors
PubMed: 24953340
DOI: 10.1002/cyto.a.22495