Propidium iodide as an indicator of Giardia cyst viability.

SummaryThe viability of 4 human isolates ofGiardia intestinaliscysts using either the fluorogenic vital dyes fluorescein diacetate (FDA) and propidium iodide (PI) orin vitroexcystation was assessed. Whereas viable cysts, as defined byin vitroexcystation were present in each of the 4 isolates, cysts from only 3 of the 4 isolates took up the vital dyes. FDA consistently over-estimated cyst viability whilst PI under-estimated non-viable cysts when compared within vitroexcystation. Followingin vitroexcystation, both FDA and PI stained a proportion of unexcysted cysts indicating that FDA stained cysts which were incapable of excystation, whereas PI did not stain all cysts which were incapable of excystation. One human cyst isolate, which underwentin vitroexcystation, could not be stained with either FDA or PI. In the absence of currently more specific fluorescent indicators of viability, PI alone could be used to determine the lower limit of nonviability in positive water-related samples, where small numbers of cysts are to be expected.

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Determination of Giardia cyst viability in environmental and faecal samples by immunofluorescence, fluorogenic dye staining and differential interference contrast microscopy

Letters in Applied Microbiology ◽

10.1046/j.1472-765x.1998.00282.x ◽

1998 ◽

Vol 26 (4) ◽

pp. 237-242 ◽

Cited By ~ 29

Author(s):

Thiriat ◽

Sidaner ◽

Schwartzbrod

Keyword(s):

Giardia Cyst ◽

Differential Interference Contrast ◽

Differential Interference Contrast Microscopy ◽

Cyst Viability ◽

Faecal Samples ◽

Contrast Microscopy ◽

Interference Contrast Microscopy ◽

Dye Staining

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The Effect of chlorine on giardia cyst destruction isolated from different water sources in Maysan province

International Journal of Scientific World ◽

10.14419/ijsw.v4i1.5782 ◽

2016 ◽

Vol 4 (1) ◽

pp. 1

Author(s):

Rasha Al-Saad

Keyword(s):

Protozoan Parasite ◽

Threshold Level ◽

Water Sources ◽

Chlorine Concentration ◽

Health Concern ◽

Giardia Cyst ◽

Cyst Viability ◽

Untreated Water ◽

Flotation Technique ◽

Effect Of Chlorine

<p>G. lamblia was a binucleate flagellated protozoan parasite that infected the upper intestinal tract of human and many animal species. Giardiasis was the most frequently diagnosed water borne disease and the major public health concern of water utilities in the developed and developing nations. Water is an important vehicle for the transmission of Giardia to human and mammals. For identified the effect of chlorine on Giardia cyst. To detect viability of cyst in different chlorine concentration. To determine the threshold level of chlorine concentration that caused cyst destruction. Measure the pH, chlorine concentration, filtration processes and examined by zinc sulfate centrifugal flotation technique using. 50% of samples contain Giardia cysts which are untreated water sources. Cyst viability differs in different chlorine concentration in different period of time extend from few hours to more than twenty days. The extreme chlorine concentration which caused cyst destruction in hours is 1.5 mg/L.</p>

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Permeability of boar and bull spermatozoa to the nucleic acid stains propidium iodide or Hoechst 33258, or to eosin: accuracy in the assessment of cell viability

Reproduction ◽

10.1530/reprod/118.1.145 ◽

2000 ◽

pp. 145-152 ◽

Cited By ~ 38

Author(s):

B Pintado ◽

J de la Fuente ◽

ER Roldan

Keyword(s):

Nucleic Acid ◽

Propidium Iodide ◽

Hoechst 33258 ◽

Experimental Conditions ◽

Functional Studies ◽

Viable Cells ◽

Direct Microscopic Examination ◽

Acrosomal Exocytosis ◽

Viable Sperm ◽

Boar Spermatozoa

This study was designed to assess whether nucleic acid stains such as propidium iodide and Hoechst 33258 and the cytosolic stain eosin identified equivalent proportions of non-viable cells. Sub-samples of boar spermatozoa stored for up to 72 h, and frozen bull spermatozoa stored in straws and thawed before staining, were exposed to either propidium iodide or Hoechst 33258 alone or in combination. Additional sub-samples were stained with eosin-nigrosin and subsequently with Giemsa. The proportion of non-viable cells identified by propidium iodide alone was equivalent to that observed when it was used in combination with the other fluorescent probe. Similar results were observed for Hoechst 33258. However, direct microscopic examination of sub-samples exposed to both stains revealed that a proportion of spermatozoa stained with propidium iodide did not incorporate Hoechst 33258. This was found consistently in boar and bull spermatozoa under the different experimental conditions used. Quantification showed that the proportion of propidium iodide-positive cells was significantly higher than Hoechst 33258-positive cells. Furthermore, the proportion of propidium iodide-positive cells was higher than cells stained with eosin, but no differences were found between the number of cells stained with Hoechst 33258 or eosin. The proportion of cells stained with propidium iodide was positively correlated with the proportion stained with either Hoechst 33258 or eosin, despite the observation that more cells incorporated propidium iodide. Taken together, these results indicate that there are differences in the ability of fluorescent probes to identify non-viable sperm cells and that this should be considered when staining protocols are used to analyse sperm viability, or when viability is used as a discriminating factor in functional studies, such as those related to acrosomal exocytosis.

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Semaphorin 3A mediated brain tumor stem cell proliferation and invasion in EGFRviii mutant gliomas

BMC Cancer ◽

10.1186/s12885-020-07694-4 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Dominique M. O. Higgins ◽

Maisel Caliva ◽

Mark Schroeder ◽

Brett Carlson ◽

Pavan S. Upadhyayula ◽

...

Keyword(s):

Cell Cycle ◽

Stem Cell ◽

Brain Tumor ◽

Propidium Iodide ◽

Tumor Stem Cell ◽

Semaphorin 3A ◽

Brain Tumor Stem Cell ◽

Proliferation And Invasion ◽

Invasion Assays

Abstract Background Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults, with a median survival of approximately 15 months. Semaphorin 3A (Sema3A), known for its axon guidance and antiangiogenic properties, has been implicated in GBM growth. We hypothesized that Sema3A directly inhibits brain tumor stem cell (BTSC) proliferation and drives invasion via Neuropilin 1 (Nrp1) and Plexin A1 (PlxnA1) receptors. Methods GBM BTSC cell lines were assayed by immunostaining and PCR for levels of Semaphorin 3A (Sema3A) and its receptors Nrp1 and PlxnA1. Quantitative BrdU, cell cycle and propidium iodide labeling assays were performed following exogenous Sema3A treatment. Quantitative functional 2-D and 3-D invasion assays along with shRNA lentiviral knockdown of Nrp1 and PlxnA1 are also shown. In vivo flank studies comparing tumor growth of knockdown versus control BTSCs were performed. Statistics were performed using GraphPad Prism v7. Results Immunostaining and PCR analysis revealed that BTSCs highly express Sema3A and its receptors Nrp1 and PlxnA1, with expression of Nrp1 in the CD133 positive BTSCs, and absence in differentiated tumor cells. Treatment with exogenous Sema3A in quantitative BrdU, cell cycle, and propidium iodide labeling assays demonstrated that Sema3A significantly inhibited BTSC proliferation without inducing cell death. Quantitative functional 2-D and 3-D invasion assays showed that treatment with Sema3A resulted in increased invasion. Using shRNA lentiviruses, knockdown of either NRP1 or PlxnA1 receptors abrogated Sema3A antiproliferative and pro-invasive effects. Interestingly, loss of the receptors mimicked Sema3A effects, inhibiting BTSC proliferation and driving invasion. Furthermore, in vivo studies comparing tumor growth of knockdown and control infected BTSCs implanted into the flanks of nude mice confirmed the decrease in proliferation with receptor KD. Conclusions These findings demonstrate the importance of Sema3A signaling in GBM BTSC proliferation and invasion, and its potential as a therapeutic target.

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