Search

The management of hyperleukocytosis or thrombocytosis by therapeutic cytapheresis in the early 21 st century is far from codified (universal). Therapeutic cytapheresis have been proposed to achieve more rapid cytoreduction in peripheral blood than old universal support in order to quickly prevent potential complications. But, there are no randomized studies demonstrating the superiority of cytapheresis over other treatments alone. In this short review, based on our own experience (since 1980), we will give the indications and the role of cytapheresis procedures and we will try to answer the questions: when is therapeutic cytapheresis appropriate and do they still have a place in 2020, especially as a medical emergency?, (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Introduction: Predonation interview accounts for a major step in transfusion safety. In France, it must be performed by a physician, following a methodical questioning and a standardized questionnaire. Faced with this evolution, the value of a strictly medical expertise has been progressively losing importance. In many countries, blood donor selection is being organized by non medical trained staff (Québec, Switzerland, e.g.). A decree of April 30, 2006 allowed the Établissement français du sang to experiment a predonation interview by an authorized paramedical staff in the form of a two-phase prospective multicenter study over a year., Patients and Methods: Phase I "experimental situation": six physician/nurse teams among three blood transfusion centres interviewed 1940 blood-donation candidates, including 253 new donors (13% out of total). Phase 2 "observational study": 3222 blood-donation candidates were interviewed either by a physician or a nurse., Results: In phase I, nurses were able to make a decision without the physician's help in 1921 cases. A total of 1628 candidates were decided capable of donating blood both by physicians and nurses, 174 donors were rejected both by physicians and nurses and 69 were rejected either by physicians or nurses. In phase 2, out of 3222 blood-donation candidates, an average of 12.1% were rejected by nurses and 10% by physicians., Conclusion: The study reported a weaker variability among nurses. Results show that nurses were able to perform predonation interviews with high reliability, without additional risk. The reproducibility of their answers in the field of recipient-risk evaluation was better than the physicians., (Copyright © 2011. Published by Elsevier SAS.)

Multiple apheresis makes it possible to obtain at least two labile blood components from a single donor using a cell separator. It can be either multicomponent apheresis leading to the preparation of at least two different blood component types or red blood cell apheresis providing two identical red blood cell concentrates. These techniques available in addition to whole blood donation, are modifying collection strategies in many Etablissements Français du Sang and will contribute to improve stock logistics in the future. In areas with insufficient stock, these procedures will help achieve blood component self-sufficiency. The author first describes the principle underlying different--current or future--techniques as well as their advantages and drawbacks. He finally addresses the potential impact of these processes on the evolution of blood collection and the advantages to be gained.

The combination of 8-methoxypsoralen (8-MOP) and long wave ultraviolet radiation (UV-A) has immunomodulatory effects and might abolish both graft-vs-host and host-vs-graft reactions after allogeneic hematopoietic stem cell transplantation. In the present study, we have confirmed the sensitivity of T lymphocytes to 8-MOP treatment plus UV-A exposure as evidenced by the abrogation of the alloreactivity in mixed lymphocyte cultures as well as the inhibition of the response to phytohemagglutinin A. However, the clonogenic capacity of the bone marrow hematopoietic progenitors was inhibited with UV-A doses lower than the doses needed to inhibit T-lymphocytes alloreactivity. Moreover, long-term bone marrow cultures showed that 8-MOP plus UV-A treatment had detrimental effects on the more immature bone marrow stem cells. These data were confirmed when murine bone marrow graft was treated with 8-MOP, exposed to UV-A, then transplanted into semiallogeneic recipient mice. The treated cells could not maintain their clonogenic capacity in vivo resulting in death of all animals. Taken together, these data show that ex vivo 8-MOP plus UV-A treatment of the marrow graft cannot be used to prevent post-bone marrow transplantation alloreactivity.

Aims: A multicentric study involving 12 centers was made to investigate the results of peripheral stem cell collection carried out between 1996 and 1997 from 655 patients with hemopathic syndromes or malignant tumors, The aim of this investigation was to determine the predictive factors for transplant quality, and to thereby optimize collection procedures., Patients and Methods: Information sheets were completed for 1,346 cytapheretic sessions, i.e., 655 grafts. The samples were taken after induction chemotherapy and exposure to hematopoeitic colony-stimulating growth factors (except the LMCs). Each graft was defined as being of good or bad quality depending on the number of CD34+ cells that it contained. Based on the data available in the literature, a workgroup consensus was reached that a level of CD34+ cells +/- 2.10(6)/kg recipient body weight constituted a good transplant criterion. The 2 subgroups (good graft versus lower quality graft) were compared by univariate analysis followed by discriminant multivariate analysis., Results: It was established that a number of parameters were significantly linked to the criterion of collection quality; however, 3 predictive factors emerged from the multivariate analysis--the level of circulating CD34+ cells; the number of cytaphereses; the number of blood volumes treated., Conclusion: It was concluded that the level of circulating CD34+ cells seems to be an essential aspect in predicting the quality of the transplant and the number of cytaphereses required to obtain a sufficiently rich collection. Moreover, it also appears that at least 2 blood volumes should be treated to optimize the results.

We show that pyruvate decarboxylase (PDC) 8- to 10-nm-diameter filaments, first described in vegetative cells of Neurospora crassa, are ubiquitously present in filamentous fungi. The cellular arrangement of these structures was examined over the entire sexual cycle of the ascomycetes N. crassa, N. tetraesperma, Podospora anserina, and Sordaria macrospora. PDC-filaments were found associated with the cortical microtubule array of asci and ascospores and absent from the vicinity of spindles and spindle pole bodies. Nocodazole-induced depolymerization of the cortical microtubules results in the loss of PDC-filaments. Moreover, a S. macrospora mutant defective in cortical MT distribution shows abnormal PDC organization. Neurospora asci generated on various metabolic conditions, which modify the presence and relative abundance of PDC-filaments in vegetative cells, have identical patterns of subcellular distribution of these structures. A N. crassa mutant (snowflake) that accumulates giant bundles of PDC-filaments during vegetative growth, shows normal distribution of the filaments during ascogenesis. Thus, the regulation conditioning the presence and supramolecular assembly of PDC-filaments in Neurospora differs between vegetative and sexual cells. Taken together, these results suggest that PDC in filamentous fungi may perform two functions, intervening as an enzyme in vegetative metabolism and as a structural protein associated with the cytoskeleton during sexual development., (Copyright 1999 Academic Press.)

The Podospora anserina cro1 gene was identified as a gene required for sexual sporulation. Crosses homozygous for the cro1-1 mutation yield fruiting bodies which produce few asci due to the formation of giant plurinucleate cells instead of dikaryotic cells after fertilization. This defect does not impair karyogamy, but meioses of the resultant polyploid nuclei are most often abortive. Cytological studies suggest that the primary defect of the mutant is its inability to form septa between the daughter nuclei after each mitosis, a step specific for normal dikaryotic cell divisions. The cro1-1 mutant would thus be unable to leave the syncytial vegetative state while abiding by the meiotic programme. cro1-1 also shows defects in ascospore germination and growth rate. GFP-tagging of the CRO1 protein reveals that it is a cytosolic protein mainly expressed at the beginning of the dikaryotic stage and at the time of ascospore maturation. The CRO1 protein exhibits significant similarity to the SHE4 protein, which is required for asymmetric mating-type switching in budding yeast cells. Thus, a gene involved in asymmetric cell divisions in a unicellular organism plays a key role at the transition between the syncytial (vegetative) state and the cellular (sexual) state in a filamentous fungus.

A novel isolation of centrosomes is described and it was used to both generate a centrosome-specific monoclonal antibody and to image with high-resolution low-voltage scanning electron microscopy the surface details of the isolated centrosome. At first mitotic prometaphase, sea urchin zygotes are chilled on ice overnight. While most of the microtubules disassemble, the mitotic centrosomes collapse into aggregated masses. These centrosomes have been isolated, and used to generate a monoclonal antibody, designated 4D2, which is reactive with interphase and mitotic centrosomes. 4D2 staining of centrosomes is similar, but not identical, to that of other centrosomal antibodies like Ah6 and 5051. Centrosomal material is detected as a compact sphere after cold treatment; upon recovery the sphere expands and undergoes the shape changes previously described [Mazia et al., 1987: J. Cell Biol. 105:206a] to eventually reorganize a normal mitotic apparatus.

The car1 gene of the filamentous fungus Podospora anserina was cloned by complementation of a mutant defective for caryogamy (nuclear fusion), a process required for sexual sporulation. This gene encodes a protein that shows similarity to the mammalian PAF1 protein (Zellweger syndrome). Besides sequence similarity, the two proteins share a transmembrane domain and the same type of zinc finger motif. A combination of molecular, physiological, genetical, and ultrastructural approaches gave evidence that the P. anserina car1 protein is actually a peroxisomal protein. This study shows that peroxisomes are required at a specific stage of sexual development, at least in P. anserina, and that a functional homolog of the PAF1 gene is present in a lower eucaryote.

Surgery, after hematology, is the biggest consumer of homologous platelet concentrates. Platelet transfusion is indicated to prevent or control bleeding associated with deficiencies in platelet number or function. In surgery, general patterns (in function of pre-surgery platelet count) can be adopted in most of the indications for platelets. In emergency situations, and in some particular cases (related to the patient, the type of operation, etc.), the transfusion procedure depends on the team's experience, the results of the available clinical and biological tests, and the drugs. Strict monitoring is required during the transfusion procedure. The efficacy of the transfusion must be controlled 1 h and 24 hours after the transfusion, and a number of factors must be assessed, namely the immunological impact of the transfusion (on red blood cells, leukocytes and platelets) and the occurrence of infectious diseases transmitted via transfusion. In addition, for a possible future transfusion, a strategy must be proposed.

In heterothallic filamentous ascomycetes, two nuclei of opposite mating type must recognize one another in a plurinucleate cell to form a pair prior to karyogamy. In pseudohomothallic species, two nuclei of opposite mating type must also pair after meiosis to form a binucleate spore. We have examined the cytoskeletal involvement in nuclear pairings by immunofluorescence and drug disruption, using heterothallic and pseudohomothallic species, as well as species without defined mating type (homothallic). Nuclei of species with defined mating type have spindle pole bodies which react with chromatin stains; those of homothallic species do not. The reactivity is seen only in interphase, not during nuclear divisions; thus, the DNA concerned is nuclear and not organellar. From light and immunofluorescence microscopy, the DNA is located at the nuclear face of the spindle pole body (SPB). We suggest that the DNA-SPB association may be involved in the recognition of self and nonself between nuclei of opposite mating types. Nuclei which cooperate in cell formation during ascus development or sporulation are placed in close proximity by the arrangement of spindles during the division preceding cell formation; after division, each nuclear pair remains linked by intertwined microtubule asters. Nuclear pairs must migrate before binucleate spore formation. Drug disruptions established that actin-myosin interaction was the most important cytoskeletal factor in normal spore production. The ascomycete SPB shows unexpected flexibility in form and location during development. Prior to sporulation the outer plaque shows extensive modification in size and orientation. The modified portion detaches from the nucleus and acts as a cortical microtubule organizing center, while the rest of the spindle pole body remains at the nucleus.