RESUMO
Low reactive oxygen species (ROS) levels are well-established characteristics of mouse hematopoietic stem cells (HSCs). However, little is known about these levels in human HSCs. This study aimed at quantifying ROS levels in human CD34+ CD38low and CD34+ CD38high human progenitors from bone marrow, cord blood and cells mobilized for autologous HSC transplantation. A specifically devised multiparameter flow cytometry method was used to quantify ROS levels (H2 DCFDA staining) in sub-populations of primary cells. Results were confirmed by assessing gene expression level of the ROS scavenger GPX3, a key determinant of HSC self-renewal, in sorted CD34+ CD38low and CD34+ CD38high cells. CD34+ CD38low cells from bone marrow and cord blood displayed significantly lower levels of ROS than CD34+ CD38high cells and other leukocytes. Moreover, the correlation between ROS and GPX3 expression was verified in sorted CD34+ CD38low and CD34+ CD38high cells. These results confirm, in human, data previously reported in mice. Moreover, the flow cytometry assay we developed could allow for a more precise enumeration of repopulating primitive progenitors in the course of HSC transplantation.
Assuntos
Citometria de Fluxo , Glutationa Peroxidase/genética , Células-Tronco Hematopoéticas/citologia , Espécies Reativas de Oxigênio/metabolismo , ADP-Ribosil Ciclase 1/genética , Animais , Antígenos CD34/genética , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Linhagem da Célula/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/metabolismo , Humanos , Leucócitos/metabolismo , Camundongos , Células-Tronco/citologia , Células-Tronco/metabolismoRESUMO
OBJECTIVE: To explore the worth of a single-donor program for preterm infants through the recipient profile and the impact on donor exposure, red blood cell (RBC) pack waste, storage duration, and transfusion performance. STUDY DESIGN: Patients and transfusion characteristics were collected for 3 years (2015-2017) in preterm infants according to single-donor program prescription in a unit not practicing placental transfusion or erythropoietin supplementation. RESULTS: Among 1048 eligible preterm infants, 161 met the inclusion criteria, and 51 received single-donor packs. Our single-donor program induced a donor number reduction (34% less than the transfusion number) and an extension of storage duration (median: 9 versus 7 days, p < 0.0001) without altering the transfusion performance. However, 41% of small packs were not used. CONCLUSION: A single-donor program partially reduced donor exposure but led to drastic RBC pack waste. Optimization of transfusion alternatives may increase this phenomenon, calling into question the rationale of this practice.
Assuntos
Anemia Neonatal , Recém-Nascido Prematuro , Fatores Etários , Anemia Neonatal/terapia , Transfusão de Eritrócitos , Feminino , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Placenta , GravidezRESUMO
PURPOSE: To identify color Doppler imaging (CDI) parameters and other prognostic factors of a conversion from nonischemic to ischemic retinal vein occlusion (RVO) in a large population with a long follow-up. METHODS: This was a retrospective observational study. Data were collected for patients who had been admitted to the ophthalmologic department of the Hospital of Tours because of nonischemic central RVO (CRVO) or branch RVO (BRVO). We analyzed the relation between time until conversion into ischemic RVO and several prognostic factors of conversion, mainly vein velocities as measured by CDI. RESULTS: Analyses involved 162 patients. One year after inclusion, conversion into ischemic RVO occurred in 25.0% of the 113 CRVO and in 28.6% of the 49 BRVO cases. For CRVO, an increase of the minimal central retinal venous velocity (CRV), measured by CDI before and after treatment by hemodilution, diminished the risk of conversion into an ischemic form (p=0.048). For BRVO, an elevated maximal CRV on diagnosis was a protector (p=0.004). Age was associated with a high risk of ischemic evolution for CRVO (p=0.023) but not BRVO. Initial visual acuity was not associated with the conversion, for BRVO or CRVO. Increased retinal hemorrhages highly increased the risk of conversion both for CRVO (p<0.0001) and BRVO (p=0.010). CONCLUSIONS: Risk of ischemic evolution for BRVO and CRVO treated by isovolemic hemodilution was associated with central venous velocities. CDI might be useful for identifying risk of ischemic conversion and individualizing the follow-up of patients.
