Research publications

Found 62 publicacions matching the indicated search criteria.
Petriz J, Bradford JA, Ward MD

No lyse no wash flow cytometry for maximizing minimal sample preparation.

Methods 1 Feb 2018, 134-135 149-163. Epub 18 Dec 2017
Red blood cell lysis is an integral part of many flow cytometry protocols. It's potential to cause artifacts has been known for decades, but lysis free sample preparation has failed to replace lysis in most applications. Studies of various lysing protocols on cell losses and effects on phenotypic markers and cell function began early in the history of immunophenotyping and continue to this day. Opportunities to combine live cell response and functional assessment with phenotyping have sparked increasing interest in no lyse no wash protocols, with minimizing sample preparation effects on the cell biology as the primary goal. No lyse no wash protocols reduce sample handling and are procedurally less complex than lysis protocols, but the impact of keeping intact red blood cells that grossly outnumber the target white blood cells, must be understood to fully take advantage of this simplicity. Presented here are theories and methods for executing and interpreting no lyse no wash assays in whole blood. Methods for distinguishing white blood cells and platelets from red blood cells and improving scatter data by combining 405 nm and 488 nm side scatter are shown. Methods for assessing white blood cell light scattering profiles for individual instruments and sample treatments are discussed within the context of example profiles for no lysis and hypotonic and ammonium chloride lysis treatments. The utility of overcoming no lyse no wash scatter and fluorescence background limitations using alternate scatter and fluorescence thresholding strategies is also discussed in the context of application examples.
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G Rico L, Juncà J, Ward MD, Bradford J, Petriz J

Yellow-green laser-based flow cytometry for CD34+ progenitor cell counting.

Cytometry A Feb 2018, 93 (2) 172-176. Epub 18 Dec 2017More information
Rico LG, Juncà J, Ward MD, Bradford J, Petriz J

Is alkaline phosphatase the smoking gun for highly refractory primitive leukemic cells?

Oncotarget 6 Oct 2016, . Epub 6 Oct 2016
With the aim to detect candidate malignant primitive progenitor populations, we modified an original alkaline phosphatase (ALP) stem cell detection method based on the identification of alkaline phosphatase fluorescent cells in combination with flow cytometry immunophenotyping. Over a period of one year, we have been using this technique to study its activity in patients with leukemia and lymphoma, showing that changes in the alkaline phosphatase levels can be used to detect rare populations of highly refractory malignant cells. By screening different blood cancers, we have observed that this activity is not always restricted to CD34+ leukemic cells, and can be overexpressed in CD34 negative leukemia. We have verified that this method gives accurate and reproducible measurements and our preliminary results suggest that CD34+/ALPhigh cells appear to sustain leukemogenesis over time.
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Pachón-Peña G, Serena C, Ejarque M, Petriz J, Duran X, Oliva-Olivera W, Simó R, Tinahones FJ, Fernández-Veledo S, Vendrell J

Obesity Determines the Immunophenotypic Profile and Functional Characteristics of Human Mesenchymal Stem Cells From Adipose Tissue.

Stem Cells Transl Med Apr 2016, 5 (4) 464-75. Epub 8 Mar 2016
: Adipose tissue is a major source of mesenchymal stem cells (MSCs), which possess a variety of properties that make them ideal candidates for regenerative and immunomodulatory therapies. Here, we compared the immunophenotypic profile of human adipose-derived stem cells (hASCs) from lean and obese individuals, and explored its relationship with the apparent altered plasticity of hASCs. We also hypothesized that persistent hypoxia treatment of cultured hASCs may be necessary but not sufficient to drive significant changes in mature adipocytes. hASCs were obtained from subcutaneous adipose tissue of healthy, adult, female donors undergoing abdominal plastic surgery: lean (n = 8; body mass index [BMI]: 23 ± 1 kg/m(2)) and obese (n = 8; BMI: 35 ± 5 kg/m(2)). Cell surface marker expression, proliferation and migration capacity, and adipogenic differentiation potential of cultured hASCs at two different oxygen conditions were studied. Compared with lean-derived hASCs, obese-derived hASCs demonstrated increased proliferation and migration capacity but decreased lipid droplet accumulation, correlating with a higher expression of human leukocyte antigen (HLA)-II and cluster of differentiation (CD) 106 and lower expression of CD29. Of interest, adipogenic differentiation modified CD106, CD49b, HLA-ABC surface protein expression, which was dependent on the donor's BMI. Additionally, low oxygen tension increased proliferation and migration of lean but not obese hASCs, which correlated with an altered CD36 and CD49b immunophenotypic profile. In summary, the differences observed in proliferation, migration, and differentiation capacity in obese hASCs occurred in parallel with changes in cell surface markers, both under basal conditions and during differentiation. Therefore, obesity is an important determinant of stem cell function independent of oxygen tension.
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Nunez-Espinosa C, Garcia-Godoy MD, Ferreira I, Rios-Kristjansson JG, Rizo-Roca D, Rico LG, Rubi-Sans G, Palacio C, Torrella JR, Pages T, Ward MD, Viscor G, Petriz J

Vybrant DyeCycle Violet stain discriminates two different subsets of CD34+ cells.

Curr Stem Cell Res Ther 28 May 2015, . Epub 28 May 2015
Studies are needed to understand the role of CD34 expressing cells with regard to efficient engraftment, especially in the adjuvant treatment of cancer.
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Núñez-Espinosa C, Ferreira I, Ríos-Kristjánsson JG, Rizo-Roca D, García Godoy MD, Rico LG, Rubi-Sans G, Torrella JR, Pagès T, Petriz J, Viscor G

Effects of intermittent hypoxia and light aerobic exercise on circulating stem cells and side population, after strenuous eccentric exercise in trained rats.

Curr Stem Cell Res Ther 2015, 10 (2) 132-9.
Our goal was to address if intermittent hypobaric hypoxia (IHH) exposure can help to increase the number of peripheral blood circulating progenitor cells and side population (SP) stem cells, in order to establish the usefulness of this intervention for skeletal muscle repair, because these cells play a role in tissue regeneration. Male Sprague-Dawley rats were studied in two basal states: untrained and trained and compared with 1, 3, 7 and 14 days stages of damage recovery of trained rats that had suffered skeletal muscle injury. Three experimental groups were studied: rats with passive recovery (CTRL); rats exposed to IHH after muscle damage (HYP); and, trained rats that, in addition to IHH, performed light aerobic exercise sessions (EHYP). We observed an increase in hematopoietic stem cells (HSCs) (mean = 0.153% of cells) and endothelial progenitor cells (EPCs) (mean = 0.0020% of cells) in EHYP on day 7. Also these cells showed characteristics of more primitive progenitors in comparison to the other experimental groups (mean = 0.107% of cells), as deduced by retention of the promising fluorescent probe Vybrant Dye Cycle Violet. We concluded that intermittent exposure to hypobaric hypoxia in combination with light aerobic exercise increased the number of HSCs and EPCs on the 7th day in EHYP group, although the exercise-induced stimulus showed a reverse effect on SP kinetics.
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Pizarro S, García-Lucio J, Peinado VI, Tura-Ceide O, Díez M, Blanco I, Sitges M, Petriz J, Torralba Y, Marín P, Roca J, Barberà JA

Circulating progenitor cells and vascular dysfunction in chronic obstructive pulmonary disease.

PLoS ONE 2014, 9 (8) e106163. Epub 29 Aug 2014
In chronic obstructive pulmonary disease (COPD), decreased progenitor cells and impairment of systemic vascular function have been suggested to confer higher cardiovascular risk. The origin of these changes and their relationship with alterations in the pulmonary circulation are unknown.
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Avendaño A, Sales-Pardo I, García-Godoy MD, Rico LG, Marín P, Petriz J

Accuracy and reproducibility of stem cell side population measurements on clinically relevant products.

Curr Stem Cell Res Ther 2014, 9 (6) 526-34.
In 1996, Goodell et al. first described a rare subpopulation of bone marrow stem cells termed the Side Population (SP). SP cells are known to be CD34 negative and to have a high repopulating capability. The SP was identified by ultraviolet excitation based on the efflux of the DNA binding dye, Hoechst 33342 (Ho342). ABCG2, a halftransporter that belongs to the ATP binding cassette transporter superfamily, is the major contributor to the SP phenotype by actively pumping Ho432 selectively from stem cells. To date, very little is known about the identification of the SP in peripheral blood samples, and about its peripheral circulation, enrichment or isolation to evaluate its therapeutic potential. Due to the SP potential role in tissue regeneration, we studied the numbers of the SP in bone marrow and peripheral blood samples in regard to count accuracy and reproducibility.
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Lanza F, Campioni DC, Hellmann A, Milone G, Wahlin A, Walewski J, Spedini P, Fiamenghi C, Cuneo A, Knopińska W, Swierkowska-Czeneszew M, Petriz J, Fruehauf S, Farge D, Mohty M, Passweg J, Ruuto T, Madrigal A, Johnsen HE

Individual quality assessment of autografting by probability estimation for clinical endpoints: a prospective validation study from the European group for blood and marrow transplantation.

Biol. Blood Marrow Transplant. Dec 2013, 19 (12) 1670-6. Epub 27 Aug 2013
The aim of supportive autografting is to reduce the side effects from stem cell transplantation and avoid procedure-related health disadvantages for patients at the lowest possible cost and resource expenditure. Economic evaluation of health care is becoming increasingly important. We report clinical and laboratory data collected from 397 consecutive adult patients (173 non-Hodgkin lymphoma, 30 Hodgkin lymphoma, 160 multiple myeloma, 7 autoimmune diseases, and 28 acute leukemia) who underwent their first autologous peripheral blood stem cell transplantation (PBSCT). We considered primary endpoints evaluating health economic efficacy (eg, antibiotic administration, transfusion of blood components, and time in hospital), secondary endpoints evaluating toxicity (in accordance with Common Toxicity Criteria), and tertiary endpoints evaluating safety (ie, the risk of regimen-related death or disease progression within the first year after PBSCT). A time-dependent grading of efficacy is proposed with day 21 for multiple myeloma and day 25 for the other disease categories (depending on the length of the conditioning regimen) as the acceptable maximum time in hospital, which together with antibiotics, antifungal, or transfusion therapy delineates four groups: favorable (≤7 days on antibiotics and no transfusions; ≤21 [25] days in hospital), intermediate (from 7 to 10 days on antibiotics and <3 transfusions, ≤21 to 25 days in hospital or ≥7 days on antibiotics and no transfusions; from 21 to 30 days [25 to 34] in hospital), unfavorable (>7 days on antibiotics, >3 but <6 transfusions; >30/34 days in hospital after transplantation), and very unfavorable (>10 days on antibiotics, >6 transfusions; >30 to 34 days in hospital). The multivariate analysis showed that (1) PBSC harvests of ≥4 × 10(6)/kg CD34 + cells in 1 apheresis procedure were associated with a favorable outcome in all patient categories except acute myelogenous leukemia and acute lymphoblastic leukemia (P = .001), (2) ≥5 × 10(6)/kg CD34 + cells infused predicted better transplantation outcome in all patient categories (P < .0001) except acute myelogenous leukemia and acute lymphoblastic leukemia, (3) 1 or 2 aphereses (P = .001) predicted good outcome, (4) toxicity increased with higher graft volume reinfused (>500 mL) (P = .002), and (5) patients with a central venous catheter during both collection and infusion of PBSC had a more favorable outcome post-PBSCT than peripheral access (P = .007). The type of mobilization regimen did not affect the outcome of auto-PBSCT. The present study identified predictive variables, which may be useful in future individual pretransplantation probability evaluations with the goal to improve supportive care.
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Marín P, Jover L, Petriz J

A new approach to CD34+ hematopoietic progenitor cell counting.

Curr Stem Cell Res Ther Mar 2013, 8 (2) 163-71.
In the absence of a gold standard for hematopoietic progenitor counting, the intra-laboratory variation between commonly used strategies for progenitor assessment was compared.
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