An effective method for culturing functional human corneal endothelial cells using a xenogeneic free culture medium.

Endothelial dysfunction is a leading cause of corneal blindness in developed countries and the only available treatment is the endothelial transplantation. However, the limited availability of suitable donors remains a significant challenge, driving the exploration of alternative regenerative therapies. Advanced Therapy Medicinal Products show promise but must adhere to strict regulations that prohibit the use of animal-derived substances. This study investigates a novel culture methodology using Plasma Rich in Growth Factors (PRGF) as the only source of growth factors for primary cultures of human corneal endothelial cells (CECs). CECs were obtained from discarded corneas or endothelial rings and cultured in two different media: one supplemented with xenogeneic factors and other xenogeneic-free, using PRGF. Comprehensive characterization through immunofluorescence, morphological analyses, trans-endothelial electrical resistance measurements, RNA-seq, and qPCR was conducted on the two groups. Results demonstrate that CECs cultured in the xenogeneic-free medium exhibit comparable gene expression, morphology, and functionality to those cultured in the xenogeneic medium. Notably, PRGF-expanded CECs share 46.9% of the gene expression profile with native endothelium and express all studied endothelial markers. In conclusion, PRGF provides an effective source of xenogeneic-free growth factors for the culture of CECs from discarded corneal tissue. Further studies will be necessary to demonstrate the applicability of these cultures to cell therapies that make clinical translation possible.

Safety of bone marrow stem cell donation: a review.

Allogeneic hematopoietic stem cell transplantation (HSCT) represents the first choice of treatment or an important therapeutic option for several diseases, but it is still marked by morbidity and mortality. In contrast, the donation of hematopoietic stem cells (HSCs) is considered to be a safe procedure. The invaluable ethical source of donation and its central role in transplantation implies that the greatest attention be due to the donor and to the donation process through a serious monitoring protocol for donor safety. Both the Joint Accreditation Committee and the European Committee pay particular attention to the notification of adverse events and adverse reactions. Bone marrow donation is a well established procedure, that has now been performed for >30 years. Although it does not require drug administration, there is hospital admission for 1-3 days with 7-10 days off work. The main risk is related to the anesthesia. Pain in the aspiration area, together with astenia are considered to be the most frequent side effects, as shown by the USA National Marrow Donor Program experience in 1,193 donations. In the European Group for Blood and Marrow Transplantation analysis performed between 1993 and 2005 on 27,770 first HSCTs from bone marrow, only 1 fatal event (pulmonary embolism) and 12 serious adverse events were observed. The most frequent adverse events were cardiac. The incidence of adverse events was significantly lower (P < .05) compared with peripheral blood HSC donors, which confirms the necessity of accurate attention to donor selection and evaluation in bone marrow donation.

Molecular epidemiological investigation of an outbreak of Pseudomonas aeruginosa infection in an SCT unit.

From May to October 2006, six severe Pseudomonas aeruginosa infections were diagnosed in patients undergoing SCT in the SCT unit of the Careggi hospital (Florence, Italy). Four of the infected patients were treated consecutively in the same room (room N). On the hypothesis of a possible environmental source of infection, samples were collected from different sites that had potential for cross-contamination throughout the SCT unit, including the electrolytic chloroxidant disinfectant used for hand washing (Irgasan) and the disinfectant used for facilities cleaning. Four of the environmental samples were positive for P. aeruginosa: three Irgansan soap samples and a tap swab sample from the staff cleaning and dressing room. The AFLP (amplified fragment length polymorphism) typing method employed to evaluate strain clonality showed that the isolates from the patients who had shared the same room and an isolate from Irgasan soap had a significant molecular similarity (dice index higher than 0.93). After adequate control measures, no subsequent environmental sample proved positive for P. aeruginosa. These data strongly support the hypothesis of the clonal origin of the infective strains and suggest an environmental source of infection. The AFLP method was fast enough to allow a 'real-time' monitoring of the outbreak, permitting additional preventive measures.

A prospective, open-label noncomparative study with piperacillin-tazobactam monotherapy as management of fever in patients with acute leukemia.

We evaluated the efficacy of piperacillin-tazobactam monotherapy as empiric therapy of fever in acute leukemia patients in a total of 80 consecutive febrile episodes. The overall success rate was 75% with success without modification in 34% (afebrile at 72 h) and an overall death rate of 10%. No significant differences were seen in correlation between clinical outcome and phases of underlying disease. The success without modification was higher in patients with fever of unknown origin (FUO) than in those with documented infections (47% and 25% respectively). There were no significant differences in correlations between clinical response and degree of neutropenia. Our study suggests that empirical first-line monotherapy with piperacillin-tazobactam may be a reasonable option in patients with acute leukaemia, although in documented infections the response is frequently inadequate.

Event-free survival and cost-effectiveness in adult acute lymphoblastic leukaemia in first remission treated with allogeneic transplantation.

Allogeneic transplantation in patients with acute lymphoblastic leukaemia in first remission (ALL-CR1) has been studied in several clinical trials. However, no pooled survival analysis has yet been done. We conducted a survival meta-analysis to compare allogeneic transplantation vs chemotherapy or autologous transplantation using an intention-to-treat approach. Our study included the controlled clinical trials, wherein allocation to allogeneic transplant was based on donor availability. The event-free individual survival data were reconstructed on the basis of published information and Kaplan-Meier graphs. We then generated the meta-analytic event-free survival curves for the two treatments. The mean survival gain per patient was estimated and a simplified cost-effectiveness assessment was carried out. In the allogeneic transplantation group, 293 patients were examined and 479 as controls (four trials). The event-free survival difference was statistically significant (P=0.011). The relative risk for event occurrence was 0.79 for the experimental group vs the controls (95% CI: 0.66-0.96; P=0.017). The mean survival gain was 1 year per patient. The cost per life-year gained was less than the conventional threshold of 50,000 euros. Allogeneic transplantation in ALL-CR1 improves event-free survival as compared to chemotherapy or autologous transplantation. Its cost-effectiveness profile is acceptable.

Epstein-Barr virus-associated post-transplant lymphoproliferative disease with central nervous system involvement after unrelated allogeneic hematopoietic stem cell transplantation.

Post-transplant lymphoproliferative disorders (PTLD) represent an heterogeneous group of abnormal lymphoid proliferation related to Epstein-Barr virus (EBV) reactivation that arise early after allogeneic hematopoietic stem cell transplant (HSCT). PLTD with central nervous system (CNS) involvement has been reported in few cases. We describe the case of a 31-year-old-man who developed an EBV-related PTLD with CNS involvement 2 months after an allogeneic unrelated HSCT for acute myeloid leukemia in first complete remission who was successfully treated with rituximab, cidofovir and intrathecal infusion of methotrexate and methylprednisolone.

Allogeneic stem cell transplantation.

Allogeneic stem cell transplantation (HSCT) requires the harvest of an adequate number of stem cells (SC) from a histocompatible donor and their infusion into a patient following a conditioning regimen. During the past 35 years, the role of HSCT has changed from an experimental procedure for terminally ill patients to a curative treatment. In 2003, 1170 procedures were registered in Italy (Italian Group for Blood and Marrow Transplantation). The main reported indications were as follows: leukemia, lymphoproliferative diseases, myelodysplasia, and nonmalignant diseases such as thalassemia and severe aplastic anemia. Important changes have been observed in the last 5 years: the shift from bone marrow to peripheral blood as the SC source, the increasing number of alternative donors such as unrelated, partially matched family donors and cord blood SC, and the new extra-hematological indications including solid tumors. Moreover, the development of nonmyeloablative conditioning regimens have allowed physicians to perform HSCT in patients with advanced age or important comorbidities. In contrast, the availability of the Tyrosine kinase inhibitor (STI-571) for treatment of patients affected by chronic myelogenous leukemia, which was formerly the main indication for HSCT, has produced a dramatic decrease in the number of transplantations in this setting. HSCT performed in the early phases of disease and in young patients offers more than a 50% cure rate. The transplant-related mortality still represents the greatest obstacle, ranging from 20%-30%, despite the less toxic conditioning regimens, high-resolution HLA typing, and better supportive care. GvHD and infections remain the main causes of morbidity. As regards relapses, they correlate with disease status at the time of transplantation. Promising results have been recently obtained with haploidentical and with cord blood SC transplantation also in adult patients.

HERG potassium channels are constitutively expressed in primary human acute myeloid leukemias and regulate cell proliferation of normal and leukemic hemopoietic progenitors.

An important target in the understanding of the pathogenesis of acute myeloid leukemias (AML) relies on deciphering the molecular features of normal and leukemic hemopoietic progenitors. In particular, the analysis of the mechanisms involved in the regulation of cell proliferation is decisive for the establishment of new targeted therapies. To gain further insight into this topic we report herein a novel approach by analyzing the role of HERG K(+) channels in the regulation of hemopoietic cell proliferation. These channels, encoded by the human ether-a-gò-gò-related gene (herg), belong to a family of K(+) channels, whose role in oncogenesis has been recently demonstrated. We report here that herg is switched off in normal peripheral blood mononuclear cells (PBMNC) as well as in circulating CD34(+) cells, however, it is rapidly turned on in the latter upon induction of the mitotic cycle. Moreover, hergappears to be constitutively activated in leukemic cell lines as well as in the majority of circulating blasts from primary AML. Evidence is also provided that HERG channel activity regulates cell proliferation in stimulated CD34(+) as well as in blast cells from AML patients. These results open new perspectives on the pathogenetic role of HERG K(+) channels in leukemias.

In vitro activity of vinorelbine on human leukemia cells.

Vinorelbine (VNR) is a semi-synthetic Vinca rosea alkaloid that has been employed both as a single agent and in combination, and has shown significant antitumor activity. As little is known about VNR activity on human leukemia, we studied its in vitro cytotoxic effect on human leukemia cell lines (FLG 29.1, HL60, K562, Balm 4, CEM and Daudi) and on fresh leukemia cells from 28 patients: 2 acute myeloid leukemia (AML); 3 chronic myeloid leukemia in blastic phase (CML-BP); 5 acute lymphoblastic leukemia (ALL); 18 B-chronic lymphatic leukemia (B-CLL), employing the colorimetric INT assay and determining the IC50. We observed that VNR exerts its cytotoxic activity on leukemic cell lines in a dose-dependent fashion. The lymphoid cell lines appear more sensitive than the myeloid ones to the VNR-dependent growth inhibition. A similar pattern was noticed for leukemia cells in primary cultures. VNR is not effective on CML-BP cells, shows variable activity on the AML and ALL cells and is very effective against B-CLL cells. VNR inhibited the growth of fresh B-CLL cells from 15 of 18 patients, the IC50 doses ranging from 4 ng/ml to 83 microg/ml (doses coinciding with the plasma levels obtained in clinics). These observations strongly suggest that VNR could be useful in clinics for the treatment of B-CLL.

HERG K+ channels activation during beta(1) integrin-mediated adhesion to fibronectin induces an up-regulation of alpha(v)beta(3) integrin in the preosteoclastic leukemia cell line FLG 29.1.

Integrin receptors have been demonstrated to mediate either "inside-to-out" and "outside-to-in" signals, and by this way are capable of regulating many cellular functions, such as cell growth and differentiation, cell migration, and activation. Among the various integrin-centered signaling pathways discovered so far, we demonstrated that the modulation of the electrical potential of the plasma membrane (V(REST)) is an early integrin-mediated signal, which is related to neurite emission in neuroblastoma cells. This modulation is sustained by the activation of HERG K(+) channels, encoded by the ether-à-go-go-related gene (herg). The involvement of integrin-mediated signaling is being discovered in the hemopoietic system: in particular, osteoclasts are generated as well as induced to differentiate by interaction of osteoclast progenitors with the stromal cells, through the involvement of integrin receptors. We studied the effects of cell interaction with the extracellular matrix protein fibronectin (FN) in a human leukemic preosteoclastic cell line (FLG 29.1 cells), which has been demonstrated to express HERG currents. We report here that FLG 29.1 cells indeed adhere to purified FN through integrin receptors, and that this adhesion induces an osteoclast phenotype in these cells, as evidenced by the appearance of tartrate-resistant acid phosphatase, as well as by the increased expression of CD51/alpha(v)beta(3) integrin and calcitonin receptor. An early activation of HERG current (I(HERG)), without any increase in herg RNA or modifications of HERG protein was also observed in FN-adhering cells. This activation is apparently sustained by the beta(1) integrin subunit activation, through the involvement of a pertussis-toxin sensitive G(i) protein, and appears to be a determinant signal for the up-regulation of alpha(v)beta(3) integrin, as well as for the increased expression of calcitonin receptor.

Incubation of murine bone marrow cells in hypoxia ensures the maintenance of marrow-repopulating ability together with the expansion of committed progenitors.

We developed previously a hypoxic culture system in which progenitors endowed with marrow-repopulating ability (MRA), unlike committed progenitors, were selected and maintained better than in air. We report here an improvement to this system targeted at combining the maintenance of progenitors sustaining MRA with the numerical expansion of multipotent and committed progenitors. Murine bone marrow cells were incubated at 1% oxygen in liquid medium supplemented with stem cell factor, granulocyte colony-stimulating factor, interleukin-6 and interleukin-3. In day 8 hypoxic cultures, the numbers of high proliferative potential and granulocyte/macrophage colony-forming cells (HPP-CFC and CFU-GM) were increased with respect to time zero. Colonies generated by HPP-CFC derived from hypoxic cultures exhibited a high replating ability, whereas colonies generated by HPP-CFC derived from control cultures exhibited a low replating ability. MRA was fully maintained in hypoxia and markedly reduced in air. Thus, severe hypoxia is able to ensure a full maintenance of progenitors sustaining MRA, together with a significant expansion of in vitro-detectable clonogenic progenitors, including those endowed with replating ability. This system could contribute to the improvement of current techniques for the in vitro treatment of human haematopoietic cell populations before transplantation.

Activity of vinorelbine on B-chronic lymphocytic leukemia cells in vitro.

Vinorelbine (VNR) is a new semi-synthetic Vinca rosea alkaloid that has been employed both in combination and as a single agent, showing a significant antitumour activity. Since little is known about VNR in human leukemia, we studied the in vitro cytotoxic effect of VNR on peripheral blood lymphocytes from 18 patients affected by B-chronic lymphocytic leukemia (CLL), employing the INT assay. VNR inhibited fresh B-CLL cells from 15/18 patients in primary cultures, the ID50 doses ranging from 4 ng/ml to 83 micrograms/ml. These data strongly suggest that VNR could be effective in the treatment of B-CLL.

A simple, one-step clonal assay allows the sequential detection of committed (CFU-GM-like) progenitors and several subsets of primitive (HPP-CFC) murine progenitors.

Murine bone marrow (BM) cells were cultured in semisolid medium containing interleukin 3 (IL-3) and high doses of G-CSF. Colonies were counted twice, at day 7 and day 14, and the number of granulocyte/macrophage colony-forming units (CFU-GM) accurately estimated by the subtraction of day-14 from day-7 colonies, based on the principle that colonies detectable at day 7 and persisting beyond day 14 are generated by significantly more immature progenitors. The frequency of colonies relative to their size was determined and used to define subsets of high proliferative potential colony-forming cells (HPP-CFC). Two main groups of HPP-CFC were considered: those generating colonies of 0.6-1.8 mm of diameter or larger than 1.8 mm. The characterization of these groups showed that they correspond to different functional subsets of HPP-CFC. The replating ability of colonies was estimated. The percentage of clonogenic progenitors in the S phase of cell cycle was measured by cytosine arabinoside suicide assay. The sensitivity of colonies to 5-fluorouracil (5-FU) in vitro was determined and their survival after an in vivo treatment with 5-FU compared with that of colony-forming units in spleen (CFU-S). This technique allowed identification of: A) CFU-GM; B) relatively mature HPP-CFC, probably corresponding to CFU-S day12; C) more primitive HPP-CFC, relatively resistant to 5-FU in vivo and closely corresponding to CFU-S day 14, and D) very primitive HPP-CFC, resistant to 5-FU in vitro. This simple, rapid, and versatile method allows the detection of a broad range of hematopoietic progenitors in murine BM, from committed progenitors to largely quiescent, primitive stem cells, as well as the evaluation of the progenitors' self-renewal and proliferative potential.