Development of the Multi-Beam Transmission Line for DTT ECRH system

The DTT tokamak, whose construction is starting in Frascati (Italy), will be equipped with an ECRH system of 16 MW for the first operation phase and with a total of 32 gyrotrons (170 GHz, ≥ 1 MW, 100 s), organized in 4 clusters of 8 units each in the final design stage. To transmit this large number of power beams from the gyrotron hall to the torus hall building a Quasi-Optical (QO) approach has been chosen by a multi-beam transmission line (MBTL) similar to the one installed at W7-X Stellarator. This compact solution, mainly composed of mirrors in “square arrangement” shared by 8 different beams, minimizes the mode conversion losses. The single-beam QOTL is used to connect each gyrotron MOU output to a beam-combiner mirror unit and, after the MBTL, from a beam-splitter mirror unit to the exvessel and launchers sections located in the equatorial and upper ports of 4 DTT sectors. A novelty introduced is that the mirrors of the TLs are embodied in a vacuum enclosure, using metal gaskets, to avoid atmospheric absorption losses and microwave leaks. The TL, designed for up to 1.5 MW per single power beam, will have a total optical path length between 84 m and 138 m from the gyrotrons to the launchers. The main straight section will travel along an elevated corridor ~10 m above the ground level. The development of the optical design reflects the constraints due to existing buildings and expected neutron flux during plasma operation. In addition, the power throughput of at least 90% should be achieved.

Unraveling the Mechanism of Maskless Nanopatterning of Black Silicon by CF4/H2 Plasma Reactive-Ion Etching

The process of deep texturization of the crystalline silicon surface is intimately related to its promising diverse applications, such as bactericidal surfaces for integrated lab-on-chip devices and absorptive optical layers (black silicon-BSi). Surface structuring by a maskless texturization appeals as a cost-effective approach, which is up-scalable for large-area production. In the case of silicon, it occurs by means of reactive plasma processes (RIE-reactive-ion etching) using fluorocarbon CF₄ and H₂ as reaction gases, leading to self-assembled cylindrical and pyramidal nanopillars. The mechanism of silicon erosion has been widely studied and described as it is for the masked RIE process. However, the onset of the erosion and the reaction kinetics leading to defined maskless patterning have not been unraveled to date. In this work, we specifically tackle this issue by analyzing the results of three different RIE recipes, specifically designed for the purpose. The mechanism of surface self-nanopatterning is revealed by deeply investigating the physical chemistry of the etching process at the nanoscale and the evolution of surface morphology. We monitored the progress in surface patterning and the composition of the etching plasma at different times during the RIE process. We confirm that nanopattering issues from a net erosion, as contributed by chemical etching, physical sputtering, and by the synergistic plasma effect. We propose a qualitative model to explain the onset, the evolution, and the stopping of the process. As the RIE process is started, a high density of surface defects is initially created at the free silicon surface by energetic ion sputtering. Contextually, a polymeric overlayer is synthesized on the Si surface, as thick as 5 nm on average, and self-aggregates into nanoclusters. The latter phenomenon can be explained by considering that the initial creation of surface defects increases the activation energy for surface diffusion of deposited CF and CF₂ species and prevents them from aggregating into a continuous Volmer-Weber polymeric film. The clusterization of the polymer provides the self-masking effect since the beginning, which eventually triggers surface patterning. Once started, the maskless texturing proceeds in analogy with the masked case, that is, by combined chemical etching and ion sputtering, and ceases because of the loss of ion energy. In the case of CF₄/H₂ RIE processes at 10% of H₂ and by supplying 200 W of RF power for 20 min, nanopillars of 200 nm in height and 100 nm in width were formed. We therefore propose that a precise assessment of surface defect formation and density in dependence on the initial RIE process parameters can be the key to open a full control of outcomes of maskless patterning.

Stepwise endo-/epicardial catheter ablation for atrial fibrillation: the Mediterranea approach

Background

Outcomes of catheter ablation (CA) among patients with non-paroxysmal atrial fibrillation (AF) are largely disappointing.

Purpose

We sought to evaluate the feasibility, effectiveness, and safety of a single-stage stepwise endo-/epicardial approach in patients with persistent/longstanding-persistent AF.

Methods

We enrolled 25 consecutive patients with symptomatic persistent (n=4) or longstanding-persistent (n=21) AF and at least one prior endocardial procedure, who underwent CA using an endo-/epicardial approach. Our anatomical stepwise protocol included multiple endocardial as well as epicardial (Bachmann's bundle [BB] and ligament of Marshall ablations) components, and entailed ablation of atrial tachycardias emerging during the procedure. The primary outcome was freedom from any AF/atrial tachycardia episode after a 3-month blanking period. The secondary outcome was patients' symptom status during follow-up.

Results

The stepwise endo-/epicardial approach allowed sinus rhythm restoration in 72% of patients, either directly (n=6, 24%) or after AF organization into atrial tachycardia (n=12, 48%). BB's ablation was commonly implicated in arrhythmia termination. After a median follow-up of 266 days (interquartile range, 96 days), survival free from AF/atrial tachycardia was 88%. Antiarrhythmic drugs could be discontinued in 22 patients (88%). As compared to baseline, more patients were asymptomatic at 9-month follow-up (0% vs- 56%, p=0.02). Five patients (20%) developed mild medical complications, whereas one subject (4%) had severe kidney injury requiring dialysis.

Conclusion

A single-stage endo-/epicardial CA resulted in favorable rhythm and symptom outcomes in a cohort of patients with symptomatic persistent/longstanding-persistent AF and one or more prior endocardial procedures. Epicardial ablation of BB was commonly implicated in procedural success.

Funding Acknowledgement

Type of funding sources: None.

Assessment of Possible Application of an Atmospheric Pressure Plasma Jet for Shelf Life Extension of Fresh-Cut Salad

Ready-to-eat salads are very perishable with quality losses within 6–7 days, and the extension of their shelf life is still a challenge. In this work, an atmospheric pressure plasma jet (APPJ) was applied for the surface decontamination of fresh-cut lettuce baby leaves. The APPJ antimicrobial efficiency on the natural microbiota and its impact on some physicochemical attributes of lettuce were evaluated as a function of the treatment duration (0–30 s). Then, the influence of plasma treatment on the salad shelf life was studied, following the growth of aerobic mesophilic bacteria in both untreated and plasma-treated samples during 9 days of storage at 4 °C, together with the plasma-induced changes in physicochemical parameters of lettuce leaves. The APPJ induced a fast (15 s) microbial decontamination (1.3 log₁₀ CFU/g) of the salad surface. Exposure time and salad-plasma plume distance were the parameters that substantially affected the microbial inactivation. APPJ treatment retarded bacterial growth during the refrigerated storage, as plasma-treated samples were noticeably less contaminated than the non-treated ones in the first 3–4 days. No significant effect were observed on electrolyte leakage, pH, and dry matter content in both the set up phase and the shelf life study.

Haploidentical HSCT with post transplantation cyclophosphamide versus unrelated donor HSCT in pediatric patients affected by acute leukemia

T-cell replete hematopoietic stem cell transplantation (HSCT) from a haploidentical donor followed by high doses of cyclophosphamide has been demonstrated to provide the best chances of a cure for many children in need of an allograft but who lack both a sibling and an unrelated donor. In this study we retrospectively compared the outcome of pediatric patients undergoing T-replete haploidentical HSCT (Haplo) for acute leukemia with those undergoing transplantation from unrelated HLA-matched donor (MUD) and HLA mismatched unrelated donor (MMUD) from 2012 to 2017 at our Center. Both univariable and multivariable analyses showed similar 5-year overall survival rates for MUD, MMUD, and Haplo patients: 71% (95% CI 56-86), 72% (95% CI 55-90), and 75% (95% CI 54-94), respectively (p = 0.97). Haplo patients showed reduced event-free survival rates compared to MUD and MMUD patients: 30% (95% CI 12-49) versus 70% (95% CI 55-84) versus 53% (95% CI 35-73), respectively (p = 0.007), but these data were not confirmed by a multivariable analysis. Non-relapse mortality (NRM) and relapse incidence (RI) were similar for the three groups. Therefore, our data confirm that Haplo is a suitable clinical option for pediatric patients needing HSCT when lacking both an MUD and an MMUD donor.

Umbilical Cord Blood Stem Cell Transplantation

Human umbilical cord blood as an alternative source of hematopoietic stem cells for bone marrow reconstitution, has recently been demonstrated to yield successful HLA-matched placental blood grafts in children. It has been shown that cord blood contains sufficient progenitor cells to effect hematological reconstitution. Since then, more than 25 cord blood stem cells (CBSCs) transplants have been performed worldwide for the treatment of a variety of malignant and nonmalignant diseases. The majority of the grafts performed thus far have utilized CBSCs from HLA-identical siblings. However, much of the interest in this setting is devoted to the potential use of CBSCs for HLA-mismatched and unrelated transplants. Preliminary results suggest that allorecognition and graft-versus-host disease may be less intense in CBSCs transplants than in recipients of similarly compatible bone marrow.

This review summarizes the results and potential future applications of cord blood transplantation.

'Real-life' report on the management of chronic GvHD in the Gruppo Italiano Trapianto Midollo Osseo (GITMO)

Several guidelines have been published about management of chronic GvHD (cGvHD), but the clinical practice still remains demanding. The Gruppo Italiano Trapianto di Midollo Osseo (GITMO) has planned a prospective observational study on cGvHD, supported by a dedicated software, including the updated recommendations. In view of this study, two surveys have been conducted, focusing the management of cGvHD and ancillary therapy in cGvHD, to address the current 'real life' situation. The two surveys were sent to all 57 GITMO centers, performing allografting in Italy; the response rate was 57% and 66% of the interviewed centers, respectively. The first survey showed a great disparity especially regarding steroid-refractory cGvHD, although extracorporeal photo-apheresis resulted as the most indicated treatment in this setting. Another challenging issue was the strategy for tapering steroid: our survey showed a great variance, and this disagreement could be a real bias in evaluating outcomes in prospective studies. As for the second survey, the results suggest that the ancillary treatments are not standardized in many centers. All responding centers reported a strong need to standardize management of cGvHD and to participate in prospective trials. Before starting observational and/or interventional studies, a detailed knowledge of current practice should be encouraged.

Low density polyethylene functionalized with antibiofilm compounds inhibits Escherichia coli cell adhesion

The present work concerns an efficient strategy to obtain novel medical devices materials able to inhibit biofilm formation. The new materials were achieved by covalent grafting of p-aminocinnamic or p-aminosalicylic acids on low density polyethylene coupons. The polyethylene surface, previously activated by oxygen plasma treatment, was functionalized using 2-hydroxymethylmetacrylate as linker. The latter was reacted with succinic anhydride affording the carboxylic end useful for the immobilization of the antibiofilm molecules. The modified surface was characterized by scanning electron microscope, X-ray photoelectron spectroscopy, attenuated total reflectance Fourier transform infrared and fluorescence analyses. The antibiofilm activity of the modified materials were tested against Escherichia coli biofilm grown in the Center of Disease Control biofilm reactor. The results revealed that the grafted cinnamic and salicylic acid derivatives reduced biofilm biomass, in comparison with the control, by 73.7 ± 10.7% and 63.4 ± 7.1%, respectively. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3251-3261, 2017.

Monitoring of TNFR1, IL-2Rα, HGF, CCL8, IL-8 and IL-12p70 following HSCT and their role as GVHD biomarkers in paediatric patients

No predictive factors are currently available to establish patient-specific GVHD risk. A panel of six serum cytokines (TNF receptor 1, IL-2 receptor alfa (IL-2Rα), hepatocyte growth factor (HGF), monocyte chemo-attractant protein-2, IL-8, IL-12p70) were monitored at established time points (days -1, +1, +7, +14, +21, +28 and +60) in 170 paediatric hematopoietic SCT (HSCT) recipients. We found that higher concentrations of IL-2Rα on days +14 and +21 together with HGF on days +14 and +21 were significantly associated at a higher probability of both grade II-IV GVHD (on day +14 it was: 60% vs 28%, P=0.007) and grade III-IV (on day +14 it was: 40% vs 15%, P=0.001). The higher IL-8 serum concentration on day +28 was associated with a lower probability of chronic GVHD being 4% vs 29% (P=0.01) for patients with higher vs lower IL-8 serum concentration. These findings were confirmed when the analysis was restricted to the the matched unrelated donor group. In conclusion, even if the serum cytokine levels were related to several variables associated with HSCT, we identified two cytokines as predictors of GVHD II-IV and III-IV, translating into a higher TRM risk (17% vs 3%, P=0.004).

Evaluation of the components of the insulin-like growth factors system in GH-deficient adults: effects of twelve-month rhGH treatment

The impact of GH deficiency and rhGH replacement therapy on IGF-I, IGFBP-3 and ALS levels has been widely studied. There is less information available on IGF-II levels, the component of the ternary complex poorly dependent on GH. We investigate the components of IGFs system in 36 GHD adults (28M, 8F, age 45 +/- 14 yrs) before and after 12 months of rhGH therapy (mean dose 0.3 +/- 0.1 mg/day). One-hundred healthy sex- and age-matched subjects were studied for comparison. At baseline, GHD patients showed IGF-I and IGF-II levels and IGFs to IGFBP-3 molar ratios that were lower than controls. During therapy, IGF-I levels increased (p < 0.01) to normal range. IGF-II levels, though higher than at baseline (p < 0.01), remained lower than in controls (p < 0.01). ALS and IGFBP-3 significantly increased (p < 0.001). These modifications resulted in normalization in IGF-I to IGFBP-3 ratio, while no change in IGF-II to IGFBP-3 ratio was observed. In conclusion, the increase of serum IGF-II levels during rhGH treatment in GHD patients probably reflects the increase in the other components of ternary complex (ALS and IGFBP-3). However, serum IGF-II levels as well as IGF-II to IGFBP-3 ratio, although increased, were definitely lower than in controls. This last result, given the increasing evidences of a direct implication of IGF-II in cancer, may further confirm the safety of rhGH replacement in adults with severe GHD as diagnosed by appropriate stimulation tests.

Unrelated bone marrow transplantation in thalassemia. The experience of the Italian Bone Marrow Transplant Group (GITMO)

BACKGROUND AND OBJECTIVES

Allogeneic bone marrow transplantation (BMT) is a widely accepted therapeutic approach in homozygous beta-thalassemia. However, the majority of patients do not have a genotypically identical donor within the family. This prompted us to conduct a pilot study to investigate the feasibility of matched unrelated bone marrow transplantation in thalassemia. The major drawback was the high risk of immunologic and transplant-related complications, mainly graft-versus-host disease (GvHD) and graft failure.

DESIGN AND METHODS

Our aim was to reduce this risk through careful selection of donor/recipient pairs. HLA haplotypes that show a high linkage disequilibrium among their class I, class II and class III alleles are considered extended or ancestral haplotypes.

RESULTS

These haplotypes are conserved and can be shared by apparently unrelated individuals. Our study shows that matching for these haplotypes significantly improves the outcome of unrelated bone marrow transplantation in thalassemia. In fact, results were comparable to those obtained in transplants using HLA-identifical family donors.

INTERPRETATION AND CONCLUSIONS

Better results were obtained in patients with lesser iron overload and when the donor shared an identity for the DPB1 alleles.

High-dose chemotherapy in the treatment of relapsed osteosarcoma: an Italian sarcoma group study

PURPOSE

To study the feasibility and activity of two courses of high-dose chemotherapy (HDCT) in patients with osteosarcoma in metastatic relapse.

PATIENTS AND METHODS

Patients with high-grade osteosarcoma in metastatic relapse (multiple metastases or solitary metastasis at intervals of less than 30 months) were eligible for study. High-dose chemotherapy consisted of carboplatin and etoposide followed by stem-cell rescue. A second course was planned 4 to 6 weeks after the first. Surgery was performed before or after HDCT.

RESULTS

Thirty-two patients were enrolled onto the study. At the end of the treatment, 25 patients were in complete remission (CR), six were alive with disease progression, and one died of toxicity. At present, 14 patients are alive with a median survival time of 23 months from study entry: four are in first CR, three are in second CR, and one is in fourth CR. Six patients are alive with disease. Eighteen patients (56%) died: 17 of disease and one of toxicity. Transplantation-related mortality was 3.1%. The relapse or progression disease rate was 84.4%. The 3-year overall survival rate is 20% and the 3-year disease-free survival rate is 12%.

CONCLUSION

HDCT combined with surgery is feasible and can induce CR in a large portion of patients. Two points, however, need to be considered: only patients who are chemosensitive to induction treatment can obtain CR after HDCT, and the length of remission is short, because most patients relapse. Thus novel strategies are needed to maintain the remission status or to treat patients who do not respond to induction treatment.

Impact of thrombotic thrombocytopenic purpura on leukemic children undergoing bone marrow transplantation

Thrombotic thrombocytopenic purpura (TTP) has emerged as one of the main transplant-related complications over the last 15 years. The current study defines the incidence and the risk factors for the occurrence of TTP in 131 consecutive leukemic children who were transplanted between January 1994 and December 1997 at four Italian pediatric centers. Patients with ALL (101), AML (21), MDS (9), underwent an HLA-identical sibling BMT (82) or an HLA-identical unrelated BMT (49), receiving a conditioning regimen consisting of high-dose chemotherapy in 24 patients and of F-TBI combined with high-dose chemotherapy in 107 patients. The diagnosis of TTP was retrospectively evaluated on the basis of parallel criteria. TTP treatment varied according to the protocol of each treatment center. Twenty-eight of 131 patients (21.4%) developed TTP at a median of 46 days (range 21-80) after BMT. Multivariate analysis demonstrated that the risk of TTP was higher in patients who underwent unrelated BMT (P value = 0.02). Acute GVHD, stage of disease at BMT, conditioning with TBI, gender, age, did not appear to be associated with the occurrence of TTP. As to the outcome, TTP resolved in 19 patients while in nine it was the principal cause of death (32.1%). In patients with TTP, LDH peak value was the only statistically significant factor (P = 0.001) related to severe TTP. In conclusion, our experience demonstrates that leukemic children undergoing BMT, especially from an unrelated donor, should be carefully assessed for TTP which appears to be a severe and relatively common transplant-related complication when strict diagnostic criteria are applied.

Allogeneic transplantation of peripheral blood progenitor cells in children: experience of two pediatric centers

Between February 1995 and August 1997, 11 children (eight males, three females) aged 4-16 years (median 7 years) underwent allogeneic PBPC transplantation for treatment of hematological disorders. Seven patients with acute leukemia (n = 5 ALL, n = 1 AML) or lymphoma (n = 1) received primary allogeneic PBPC transplantation, four patients received a second allotransplantation for graft failure (n = 1 AML, n = 1 sickle cell anemia) or disease recurrence (n = 1 ALL, n = 1 MDS). Five donors were HLA-identical siblings, five were 0-1 antigen mismatched family members and one was a matched unrelated donor. Donors received G-CSF 10-12 microg/kg/day for 3-7 days, and underwent one or two leukaphereses. The median cell yield per donor expressed per kg of recipient body weight was as follows: mononucleated cells 10.8 x 10(8)/kg (range 4.7-21.2); CD34+ cells 8.6 x 10(6)/kg (range 3.2-22); CD3+ cells 3.7 x 10(8)/kg (range 2.7-7.5). All patients achieved an ANC >0.5 x 10(9)/l after a median of 12 days (11-18). An unsupported platelet count >50 x 10(9)/l was reached 15 days (13-21) after PBPC transplantation; four patients failed to reach this threshold. Acute GVHD (aGVHD) grades II to IV occurred in eight (73%) patients: seven of them experienced grade III-IV aGVHD. Seven patients evaluable for chronic GVHD (cGVHD) were scored as absent in five, limited in one and extensive in one patient. As of September 1997, six patients (55 %) were alive between 60 and 938 days post-transplant (median follow-up 274 days); four patients with malignancy were alive in CR after primary allotransplantation, two patients were alive after a second PBPC transplant. Five patients have died with the main causes of death being aGVHD (n = 3), ARDS (n = 1), relapse of the underlying disease (n = 1). In conclusion, despite the limited number of patients, these preliminary results indicate that PBPC may be considered as an alternative to bone marrow for allografting also in children.

Feasibility of high-dose chemotherapy and autologous peripheral blood stem cell transplantation in children with high grade osteosarcoma

An Italian-Scandinavian treatment and research protocol with high-dose chemotherapy and double peripheral blood stem cell (PBSC) transplantation has been designed in an attempt to improve overall results of children with metastatic osteosarcoma (OST). Six patients, aged 12-17 years, underwent PBSC mobilization with CY 4 g/m2 and VP-16 600 mg/m2 followed by G-CSF (n = 4 with recurrent disease) or ifosfamide 15 g/m2 plus G-CSF (n = 2 with synchronous metastases). The target dose of CD34+ cells for two transplant procedures was 8 x 10(6)/kg or more; conditioning regimen for both the grafts consisted of carboplatin 375 mg/m2/day for 4 days and VP16 450 mg/m2/day for 4 days. The first transplant was planned 2-4 weeks after the mobilization, the second transplant 4-6 weeks after the first graft. In three patients a single course of CY-VP16 mobilised a total number of CD34+ sufficient for two transplants; in the patient who did not obtain the target dose of CD34+ cells a bone marrow harvest was added. In the two other children high-dose ifosfamide failed to achieve the required CD34+ number: one patient underwent a single transplant procedure, one patient was successfully mobilized with doxorubicin 90 mg/m2 plus G-CSF. Patients underwent a median of two collections (range 2-4). Leukapheresis resulted in the collection of a median of 8.9 CD34+ cells/kg (range 1.3-14.8). The median time to granulocyte count recovery to more than 0.5 x 10(9)/l was 10 days (range 9-14 days) after the first graft and 11 days (range 10-12 days) after the second graft, respectively. Platelets recovered to 50 x 10(9)/l at a median of 11 (range 10-30 days) and 13 days (range 10-28) respectively after the first and the second graft. Conditioning regimen was well tolerated in all patients with mild extra haematological toxicity, also following the second transplant. Two patients grafted with metastases at diagnosis are alive and disease free 3 and 7 months from the transplant. One of the four patients transplanted for recurrent disease developed pulmonary metastases 2 months after the procedure; one patient is alive with significant reduction of tumor mass 1 month after the first transplant, one patient is alive without evidence of disease 9 months from the second transplant and one after a complete metastasectomy (tumor necrosis >90%) which followed the second transplant. With the limits of the small number of cases and the short follow-up, these preliminary results show that this approach may be promising for the treatment of patients with metastatic OST who currently are not cured by conventional-dose regimens.

Induction of apoptosis in human retinoblastoma cells by topoisomerase inhibitors

PURPOSE

To examine the apoptotic effect induced in human retinoblastoma Y79 cells by camptothecin, etoposide, and amsacrine, to examine the effect of these drugs on the expression of many apoptosis-related modulators, and to test the antiapoptotic effect exerted by insulin-like growth factor-I (IGF-I).

METHODS

Morphologic features of apoptosis were demonstrated using acridine orange- ethidium bromide staining and electron microscopy. DNA fragmentation was determined by means of an in situ cell detection procedure (TdT-dUTP terminal nick-end labeling [TUNEL]) or by electrophoresis on agarose gels and was quantified by enzyme-linked immunosorbent assay. The expression of apoptosis-related modulators was studied by western blot analysis. The processing of latent p53 was examined by means of pulse- chase analysis.

RESULTS

Camptothecin, etoposide, and amsacrine induced apoptosis in Y79 cells in a dose-dependent manner; camptothecin was the most efficacious compound. The effect, which was dependent on macromolecular synthesis, appeared after a lag of 8 hours and increased for as long as 24 hours. It was lower in cells treated with IGF-I, a potent mitogenic factor. Camptothecin and etoposide increased the p53 level after 4 hours of treatment, before the onset of apoptosis. This effect seemed to be a consequence of the conversion of latent p53 to one that is transcriptionally active. The drugs also induced an increase in p53-related proteins, such as p21, Bax, and IGF binding protein-3 (IGF-BP3), and caused a significant reduction of the Bcl-2 level. The latter effect was less evident in cells pretreated with IGF-I.

CONCLUSIONS

Topoisomerase inhibitors induce apoptosis in Y79 cells. This event is accompanied by a decrease in the expression of Bcl-2, a death antagonist, and an increase in that of Bax, a death agonist. A probable consequence of these modifications is the activation of ICE-like activity with degradation of poly-(adenosine diphosphate [ADP] ribose)-polymerase. Insulin-like growth factor-I exerts an antiapoptotic action in Y79 cells, and this function is most likely reduced by the overexpression of IGF-BP3 that is induced by drug treatment.

Acute myositis following autologus bone marrow transplantation (BMT)

A 4-year-old boy with acute myeloid leukemia developed acute myositis associated with refractory thrombocytopenia one month after autologous bone marrow transplantation (BMT). Clinical, electromyographic and biohumoral features were consistent with the diagnosis of myositis. The patient responded to corticosteroids, and 39 months after BMT he is in complete remission and has regained good muscle function. Although we could not determine with certainty the specific pathophysiologic mechanism of this complication, it should be pointed out that acute myositis can occur in the early post-BMT period.

The role of thalidomide in the treatment of refractory chronic graft-versus-host disease following bone marrow transplantation in children

Chronic graft-versus-host disease (cGVHD) is a frequent complication of allogeneic bone marrow transplantation (BMT). Thalidomide was found to have immunosuppressive properties and it has been used in a limited number of children with cGVHD. We report our experience with refractory and/or high-risk cGVHD in 14 children. Six children showed complete clinical response to thalidomide in a median time of 2 months. Four children had partial responses and four failed. Side-effects were usually mild (somnolence, constipation) and only two patients developed sensory peripheral neuropathy. An increased incidence of infectious complications attributable to thalidomide was not observed. Nine out of 10 responding patients are alive 49-111 months post-BMT. Thalidomide can be effective particularly in children with prevailing mucocutaneous cGVHD. All patients should be carefully monitored to detect peripheral neuropathy early.

Etoposide-containing regimens with autologous bone marrow transplantation in children with malignant brain tumors

Despite improvements in neurosurgical and neuroradiotherapeutic techniques, children with malignant brain tumors have a dismal prognosis. In an attempt to improve the efficacy of cytotoxic therapy, dose intensification of effective chemotherapeutic agents followed by autologous bone marrow transplantation (BMT) has been tried. Between May 1991 and August 1996, high-dose chemotherapy and autologous BMT were administered to 11 children with malignant brain tumors: 10 had recurrent (n = 8) or progressive (n = 2) disease, and 1 was treated before progression. The histological diagnoses were medulloblastoma (3), glioblastoma multiforme (2), supratentorial PNET (2), ependymoma (2), anaplastic astrocytoma (1), and anaplastic oligodendroglioma (1). In 6 of the 11 patients measurable disease was present at the time of BMT. The preparative regimen included BCNU 600 mg/m2 and VP16 1500 mg/m2 in 5 cases, and thiotepa 900 mg/m2 and VP16 1500 mg/m2 in 6 cases. The median times to achieve a neutrophil count over 0.5 x 10(9)/l and a platelet count over 50 x 10(9)/l were 14 and 28 days, respectively. The overall incidence of severe toxicity (grade III-IV) was 18% and consisted of oropharyngeal mucositis and diarrhea. Among the 6 patients with measurable disease at the time of BMT there were 2 with stable disease, whereas 4 patients had tumor progression: all these patients died of tumor recurrence 2-10 months after BMT. Five patients in whom there was no evidence of disease at the time of BMT are alive and free of progression with a median follow-up of 20 months (range 3-67). These preliminary results show that high-dose chemotherapy and BMT may be effective in children with malignant brain tumors. Etoposide-containing regimens seem to have significant activity in this setting, and the toxicity was manageable. The most important variable prognostic for progression-free survival is the disease status at the time of transplantation.

Cryptococcal meningitis following a thrombotic microangiopathy in an unrelated donor bone marrow transplant recipient

In patients undergoing bone marrow transplantation cryptococcosis is rarely encountered. We report a fatal case of Cryptococcus meningitis in a 12-year-old girl with acute lymphoblastic leukemia (ALL) in second remission who had a transplant from a human leukocyte antigen (HLA)-identical unrelated bone marrow donor. The conditioning regimen was thiotepa, cyclophosphamide, and total body irradiation (TBI); graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporin A, methotrexate, and antilymphocyte globulin (ALG). The patient experienced stage III GVHD responsive to high-dose corticosteroids. On day +54 a thrombotic microangiopathy occurred. On day +64 neurological status worsened; a brain computed tomographic (CT) scan showed hyperdense lesions suggesting fungal infection. Detection of cryptococcal antigen by latex agglutination was positive but India ink stain and culture were negative. Despite treatment with amphotericin B, 5-flucytosine, and granulocyte-macrophage colony-stimulating factor, the patient died 13 days after the diagnosis.

Usefulness of frequency analysis of cytotoxic T-lymphocytes precursors (CTL-p) for selection of HLA matched unrelated marrow donors

A child with Sanfilippo syndrome and 5 potential unrelated marrow donors were typed serologically, tested in mixed lymphocyte reaction and typed by restriction fragment length polymorphism analysis in attempt to find a suitable donor. All donors were found to be identical with the recipient, however, these studies were not conclusive in identifying the best match donor. Therefore, recipient-donor pairs were examined by HLA-DR oligotyping. In addition we have studied the potential of cytotoxic T-lymphocytes precursors (CTL-p) analysis as a means of selection for matched unrelated donors. Low frequencies (1/10(5)) of pretransplant CTL-p correlated with oligotyping identity in all donor-recipient pairs evaluated. In one case oligotyping disclosed a previously unrecognized HLA-DRB1 disparity. This resulted in high frequencies of CTL-p (1/35,000). Based on this experience we can argue that CTL-p analysis may be used as an additional tool for selection of compatible unrelated marrow donors.

Monitoring of cyclosporine blood levels from central venous lines: a misleading assay?

In order to assess the suspected influence of indwelling lines on the measurement of cyclosporine (CSA) blood levels, we evaluated CSA concentrations in samples drawn simultaneously from both silicone catheter lumens and peripheral veins of eight bone marrow transplant recipients. Blood samples were obtained at 30 min or 6-12 h after discontinuation of intravenous CSA. CSA concentrations were determined in whole blood by specific monoclonal antibody assay. Mean CSA levels from the lumen used for CSA administration were significantly higher than those from samples drawn from the second lumen (i.e., not used for CSA infusion) or peripheral vein. This difference, obtained when the infusion had been interrupted for 30 min, was still the case 6-12 h after discontinuation of CSA infusion. No difference was found between samples obtained from the second lumen and peripheral vein. These observations suggest that CSA might be adsorbed or bound by the silicon catheter and, thus, CSA blood level measurements may be misleading. The second lumen of the catheter or a peripheral vein should be used for accurate monitoring of CSA concentrations.

Umbilical cord blood stem cell transplantation

Human umbilical cord blood as an alternative source of hematopoietic stem cells for bone marrow reconstitution, has recently been demonstrated to yield successful HLA-matched placental blood grafts in children. It has been shown that cord blood contains sufficient progenitor cells to effect hematological reconstitution. Since then, more than 25 cord blood stem cells (CBSCs) transplants have been performed worldwide for the treatment of a variety of malignant and nonmalignant diseases. The majority of the grafts performed thus far have utilized CBSCs from HLA-identical siblings. However, much of the interest in this setting is devoted to the potential use of CBSCs for HLA-mismatched and unrelated transplants. Preliminary results suggest that allorecognition and graft-versus-host disease may be less intense in CBSCs transplants than in recipients of similarly compatible bone marrow. This review summarizes the results and potential future applications of cord blood transplantation.