Flow cytometric analysis of the effects of low-level radiation exposure on natural populations of slider turtles (Pseudemys scripta)

1988 ◽  
Vol 17 (6) ◽  
pp. 837-841 ◽  
Author(s):  
John W. Bickham ◽  
Brian G. Hanks ◽  
Michael J. Smolen ◽  
Trip Lamb ◽  
J. Whitfield Gibbons
Keyword(s):  
Radiation Exposure ◽  
Flow Cytometric Analysis ◽  
Natural Populations ◽  
Low Level ◽  
Flow Cytometric ◽  
Pseudemys Scripta

Using AFLP markers to inform population management of the endemic Chatham Island toetoe, Austroderia turbaria (Poaceae).

2012 ◽  
Vol 18 (1) ◽  
pp. 33 ◽  
Author(s):  
Gary J Houliston ◽  
Murray I Dawson ◽  
Peter J De Lange ◽  
Peter B Heenan
Keyword(s):  
Management Practices ◽  
Flow Cytometric Analysis ◽  
Natural Populations ◽  
Source Material ◽  
Population Variation ◽  
Population Genetic Analysis ◽  
Flow Cytometric ◽  
Length Polymorphisms ◽  
Amplified Fragment Length Polymorphisms ◽  
Low Levels

Austroderia turbaria Connor is a threatened grass endemic to the Chatham Islands. Although formerly more widespread, remaining natural populations consist of highly fragmented remnants and/or individuals. Population genetic analysis of seed-raised progeny from six of the extant natural populations on Chatham and Pitt islands, using amplified fragment length polymorphisms (AFLPs) and microsatellite markers, shows that there are very low levels of variation (expected estimated heterozygosity He 0.023–0.030, no. of effective alleles Na 1.039–1.053), and no significant differentiation within or between populations on the two islands. Flow cytometric analysis of endosperm to embryo ratios suggests a sexual breeding system. This lack of population variation and no discernable differences between the two islands suggest that management practices such as the establishment of new populations can be carried out irrespective of the location of source material. One caveat to this is the possibility of Fusarium wilt occurring on the islands, in which case measures should be taken to best prevent spread across the range of the species.

scholarly journals Flow cytometry of bone marrow aspirates from neuroblastoma patients is a highly sensitive technique for quantification of low-level neuroblastoma

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 947
Author(s):  
Neha Jain ◽  
Shaista Sattar ◽  
Sarah Inglott ◽  
Susan Burchill ◽  
Jonathan Fisher ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Bone Marrow Involvement ◽  
Flow Cytometric Analysis ◽  
Standard Of Care ◽  
Tumour Cells ◽  
Street Hospital ◽  
Low Level ◽  
Bone Marrow Trephine ◽  
Flow Cytometric

Background: Bone marrow involvement is an important aspect of determining staging of disease and treatment for childhood neuroblastoma. Current standard of care relies on microscopic examination of bone marrow trephine biopsies and aspirates respectively, to define involvement. Flow cytometric analysis of disaggregated tumour cells, when using a panel of neuroblastoma specific markers, allows for potentially less subjective determination of the presence of tumour cells. Methods: A retrospective review of sequential bone marrow trephine biopsies and aspirates, performed at Great Ormond Street Hospital, London, between the years 2015 and 2018, was performed to assess whether the addition of flow cytometric analysis to these standard of care methods provided concordant or additional information. Results: There was good concurrence between all three methods for negative results 216/302 (72%). Positive results had a concordance of 52/86 (61%), comparing samples positive by flow cytometry and positive by either or both cytology and histology.  Of the remaining samples, 20/86 (23%) were positive by either or both cytology and histology, but negative by flow cytometry. Whereas 14/86 (16%) of samples were positive only by flow cytometry. Conclusions: Our review highlights the ongoing importance of expert cytological and histological assessment of bone marrow results. Flow cytometry is an objective, quantitative method to assess the level of bone marrow disease in aspirates.  In this study, flow cytometry identified low-level residual disease that was not detected by cytology or histology. The clinical significance of this low-level disease warrants further investigation.

scholarly journals Production of Fertile Unreduced Sperm by Hybrid Males of the Rutilus alburnoides Complex (Teleostei, Cyprinidae): An Alternative Route to Genome Tetraploidization in Unisexuals

Genetics ◽  
1999 ◽  
Vol 151 (1) ◽  
pp. 277-283
Author(s):  
M Judite Alves ◽  
M Manuela Coelho ◽  
M Isabel Próspero ◽  
M João Collares-Pereira
Keyword(s):  
Flow Cytometric Analysis ◽  
Natural Populations ◽  
Evolutionary Process ◽  
Reproductive Mode ◽  
Diploid Hybrid ◽  
Mendelian Segregation ◽  
Flow Cytometric ◽  
Hybrid Genome ◽  
Random Segregation ◽  
Diploid Sperm

Abstract The hybrid minnow Rutilus alburnoides comprises diploid and polyploid females and males. Previous studies revealed that diploid and triploid females exhibit altered oogenesis that does not involve random segregation and recombination of the genomes of the two ancestors, constituting unisexual lineages. In the present study, we investigated the reproductive mode of hybrid males from the Tejo basin, using experimental crosses and flow cytometric analysis of blood and sperm. The results suggest that diploid hybrids produced fertile unreduced sperm, transmitting their hybrid genome intact to offspring. Triploid hybrids also produced unreduced sperm, but it was not possible to obtain data concerning their fertility. Finally, tetraploid hybrids produced fertile diploid sperm, which exhibited Mendelian segregation. Tetraploid R. alburnoides may reestablish biparental reproduction, as individuals of both sexes with the appropriate constitution for normal meiosis (two haploid genomes from each parental species) are likely to occur in natural populations. Tetraploids probably have arisen from syngamy of diploid eggs and diploid sperm produced by diploid hybrid males. Diploid hybrid males may therefore play a significant role in the dynamics of the complex, starting the evolutionary process that may ultimately lead to a new sexually reproducing species.

scholarly journals Flow cytometry of bone marrow aspirates from neuroblastoma patients is a highly sensitive technique for quantification of low-level neuroblastoma

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 947
Author(s):  
Neha Jain ◽  
Shaista Sattar ◽  
Sarah Inglott ◽  
Susan Burchill ◽  
Jonathan Fisher ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
Bone Marrow Involvement ◽  
Flow Cytometric Analysis ◽  
Standard Of Care ◽  
Tumour Cells ◽  
Street Hospital ◽  
Low Level ◽  
Bone Marrow Trephine ◽  
Flow Cytometric

Background: Bone marrow involvement is an important aspect of determining staging of disease and treatment for childhood neuroblastoma. Current standard of care relies on microscopic examination of bone marrow trephine biopsies and aspirates respectively, to define involvement. Flow cytometric analysis of disaggregated tumour cells, when using a panel of neuroblastoma specific markers, allows for potentially less subjective determination of the presence of tumour cells. Methods: A retrospective review of sequential bone marrow trephine biopsies and aspirates, performed at Great Ormond Street Hospital, London, between the years 2015 and 2018, was performed to assess whether the addition of flow cytometric analysis to these standard of care methods provided concordant or additional information. Results: There was good concurrence between all three methods for negative results 216/302 (72%). Positive results had a concordance of 52/86 (61%), comparing samples positive by flow cytometry and positive by either or both cytology and histology.  Of the remaining samples, 20/86 (23%) were positive by either or both cytology and histology, but negative by flow cytometry. Whereas 14/86 (16%) of samples were positive only by flow cytometry. Conclusions: Our review highlights the ongoing importance of expert cytological and histological assessment of bone marrow results. Flow cytometry is an objective, quantitative method to assess the level of bone marrow disease in aspirates.  In this study, flow cytometry identified low-level residual disease that was not detected by cytology or histology. The clinical significance of this low-level disease warrants further investigation.

Blockade of Intravascular Hemolysis in PNH with the Terminal Complement Inhibitor Eculizumab Unmasks Low-Level Hemolysis Potentially Occurring through C3 Opsonization.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 972-972 ◽  
Author(s):  
Anita Hill ◽  
Russell P. Rother ◽  
Antonio M. Risitano ◽  
Duncan S. Cole ◽  
Matthew J. Cullen ◽  
...  
Keyword(s):  
Flow Cytometric Analysis ◽  
Complement Inhibitor ◽  
Intravascular Hemolysis ◽  
Color Flow ◽  
Low Level ◽  
Flow Cytometric ◽  
Humanized Monoclonal Antibody ◽  
Median Proportion ◽  
Apparent Relationship ◽  
Terminal Complement

Abstract Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hemolytic anemia characterized by intravascular hemolysis, often resulting in the need for red blood cell (RBC) transfusions. PNH RBCs lack two complement regulatory molecules - CD59, a terminal complement inhibitor, and CD55, a C3 convertase inhibitor. Eculizumab, a humanized monoclonal antibody that inhibits terminal complement by binding to C5, effectively controls intravascular hemolysis as determined by a dramatic reduction in lactate dehydrogenase (LDH) to levels in or just above the normal range. Control of intravascular hemolysis in these patients led to a reduction in, or cessation of, RBC transfusions. During eculizumab treatment, a majority of patients demonstrate evidence of residual, low-level hemolysis; LDH levels remain slightly elevated, haptoglobin levels are low or undetectable, and bilirubin levels are above normal. We hypothesized that this low-level residual hemolysis may be due to clearance of PNH RBCs through a C3b-mediated mechanism. Therefore we investigated C3 deposition on RBC in PNH patients before and on eculizumab. A direct antiglobulin test (DAT) using monoclonal anti-C3d was positive in 29 out of 39 PNH patients on eculizumab. Of these 29 DAT-positive patients, who were all receiving transfusions, 25 had DAT testing prior to eculizumab therapy and only one of these was positive. DAT was negative in all of 8 normal volunteers. By two-color flow cytometric analysis with anti-CD59 and anti-C3, the majority of patients on eculizumab demonstrated three distinct RBC populations: CD59+/C3− (normal RBCs); CD59-/C3− (PNH RBCs without C3 coating); and CD59-/C3+ (PNH RBCs coated by C3). No CD59+/C3+ RBCs were observed. Of 21 DAT positive eculizumab treated patients tested, the median proportion of total RBCs that were C3b positive was 17.6%. 18 of 29 [62%] eculizumab patients with a positive DAT received at least one transfusion during eculizumab therapy compared with 1 of 10 [10%] for DAT negative patients (p=0.01), although even patients who did not become transfusion independent during eculizumab treatment showed a marked reduction in transfusion requirement. The median hemoglobin value for the 29 DAT positive eculizumab patients was 9.8 g/dL compared with 11.3 g/dL in the 10 DAT negative eculizumab patients (p= 0.08). No apparent relationship between LDH and DAT positivity was observed. It is proposed that resolution of intravascular hemolysis in PNH patients on eculizumab results in deposition of C3b on the surface of PNH RBCs which may explain, at least in part, the residual low level hemolysis occurring in some patients. This appears to be a previously undescribed mechanism of RBC clearance in PNH, most likely obscured by the rapidity of intravascular hemolysis in the absence of eculizumab therapy. Despite the low-level residual hemolysis, patients continue to receive significant benefit from eculizumab treatment.

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