[Extracellular molecules controlling the contraction of airway smooth muscle and their potential contribution to bronchial hyperresponsiveness]. / La contractilité du muscle lisse des voies respiratoires est régulée par de nombreuses molécules extracellulaires qui pourraient contribuer à l'hyperréactivité bronchique.

INTRODUCTION: A significant portion of symptoms in some lung diseases results from an excessive constriction of airways due to the contraction of smooth muscle and bronchial hyperresponsiveness. A better understanding of the extracellular molecules that control smooth muscle contractility is necessary to identify the underlying causes of the problem. STATE OF KNOWLEDGE: Almost a hundred molecules, some of which newly identified, influence the contractility of airway smooth muscle. While some molecules activate the contraction, others activate the relaxation, thus acting directly as bronchoconstrictors and bronchodilators, respectively. Other molecules do not affect contraction directly but rather influence it indirectly by modifying the effect of bronchoconstrictors and bronchodilators. These are called bronchomodulators. Some of these bronchomodulators increase the contractile effect of bronchoconstrictors and could thus contribute to bronchial hyperresponsiveness. PROSPECTS: Considering the high number of molecules potentially involved, as well as the level of functional overlap between some of them, identifying the extracellular molecules responsible for excessive airway constriction in a patient is a major contemporary challenge.

Forward and inverse problems in the mechanics of soft filaments.

Soft slender structures are ubiquitous in natural and artificial systems, in active and passive settings and across scales, from polymers and flagella, to snakes and space tethers. In this paper, we demonstrate the use of a simple and practical numerical implementation based on the Cosserat rod model to simulate the dynamics of filaments that can bend, twist, stretch and shear while interacting with complex environments via muscular activity, surface contact, friction and hydrodynamics. We validate our simulations by solving a number of forward problems involving the mechanics of passive filaments and comparing them with known analytical results, and extend them to study instabilities in stretched and twisted filaments that form solenoidal and plectonemic structures. We then study active filaments such as snakes and other slender organisms by solving inverse problems to identify optimal gaits for limbless locomotion on solid surfaces and in bulk liquids.

Quantitative flow analysis of swimming dynamics with coherent Lagrangian vortices.

Undulatory swimmers flex their bodies to displace water, and in turn, the flow feeds back into the dynamics of the swimmer. At moderate Reynolds number, the resulting flow structures are characterized by unsteady separation and alternating vortices in the wake. We use the flow field from simulations of a two-dimensional, incompressible viscous flow of an undulatory, self-propelled swimmer and detect the coherent Lagrangian vortices in the wake to dissect the driving momentum transfer mechanisms. The detected material vortex boundary encloses a Lagrangian control volume that serves to track back the vortex fluid and record its circulation and momentum history. We consider two swimming modes: the C-start escape and steady anguilliform swimming. The backward advection of the coherent Lagrangian vortices elucidates the geometry of the vorticity field and allows for monitoring the gain and decay of circulation and momentum transfer in the flow field. For steady swimming, momentum oscillations of the fish can largely be attributed to the momentum exchange with the vortex fluid. For the C-start, an additionally defined jet fluid region turns out to balance the high momentum change of the fish during the rapid start.

Focal nodular hyperplasia of the liver: an emerging complication of hematopoietic SCT in children.

Hepatic focal nodular hyperplasia (FNH) is a nonmalignant condition rarely affecting children previously treated for cancer, especially those who received hematopoietic SCT (HSCT). Some aspects of its pathogenesis still remain unclear and a strong association with specific risk factors has not yet been identified. We report here a single institution's case series of 17 patients who underwent HSCT and were diagnosed with FNH, analyzing retrospectively their clinical features and the radiological appearance of their hepatic lesions. We aimed to compare the diagnostic accuracy of ultrasound (US) and magnetic resonance imaging (MRI) and to explore the role of transient elastography (FibroScan) to evaluate the degree of hepatic fibrosis in FNH patients. Our analysis showed an association of FNH with age at transplant ⩽12 years (hazard ratio (HR) 9.10); chronic GVHD (HR 2.99); hormone-replacement therapy (HR 4.02) and abdominal radiotherapy (HR 4.37). MRI proved to be a more accurate diagnostic tool compared with US. Nine out of 12 patients who underwent FibroScan showed hepatic fibrosis. Our study points out that FNH is an emerging complication of HSCT, which requires a lifelong surveillance to follow its course in cancer patients.

Contrast-enhanced ultrasound findings in soft-tissue lesions: preliminary results.

OBJECTIVES: There is currently no widely available, minimally invasive first-level examination that allows physicians to identify soft-tissue lesions that are likely to be malignant. The aim of this pilot study was to explore the potential suitability of dynamic contrast-enhanced ultrasound (DCE-US) for this purpose. MATERIALS AND METHODS: 23 patients were referred to the Veneto Oncological Institute for work-up of superficial soft-tissue lesions. Fourteen lesions were examined with CEUS and enhancement kinetics was analyzed. Subsequently, all lesions were surgically removed and subjected to histological analysis. RESULTS: The 14 lesions included in the study were histologically classified as malignant (n = 7) or benign (n = 7, including 3 schwannomas). A statistically significant difference between benign and malignant lesions was found in terms of mean times to peak enhancement intensity (p = 0.03) but not mean filling times (FT). When schwannomas were analyzed as a separate group, their mean FT was found to be significantly different from that of the other benign lesions (p = 0.001) and from that of the group comprising other benign lesions as well as malignant lesions (p < 0.005). CONCLUSIONS: CEUS with analysis of contrast-enhancement kinetics is a relatively low-cost, minimally invasive imaging technique, which appears to be a potentially effective first-level method for identifying suspicious soft-tissue masses.

Extracorporeal photochemotherapy may improve outcome in children with acute GVHD.

Acute GVHD (aGVHD) is a major cause of morbidity and mortality after unrelated BMT (UBMT). Our purpose was to analyze the role of extracorporeal photochemotherapy (ECP) in controlling grade II-IV aGVHD in children given UBMT. Of 41 consecutive children, 31 developed grade II-IV aGVHD after UBMT: 16 had a good response to steroids (GR group), whereas 15 underwent ECP (ECP group) within 100 days of UBMT. Eligibility criteria for starting ECP were steroid resistance, dependence or viral reactivations. Criteria for judging response to aGVHD treatment were that the resolution of all signs were considered a complete response (CR), at least a 50% improvement was classified as a partial response (PR) and stable or progressive disease was judged as no response (NR). On completing ECP, the CR rate was 73%, whereas the GR group had a CR rate of 56% by day 100. The 2-year overall survival and progression-free survival rates were 57 and 67% in the GR group vs 85 and 87% in the ECP group. Our data seem to suggest that ECP may improve outcome in patients after UBMT. These findings need to be confirmed in a larger population.

Unrelated bone marrow transplantation for high-risk anaplastic large cell lymphoma in pediatric patients: a single center case series.

OBJECTIVES: The use of allogeneic stem cell transplantation in NHL patients is not yet clearly defined, especially in children and adolescents, but this option offers the advantages of a tumor-free graft and the possible induction of a graft-vs.-tumor effect. PATIENTS AND METHODS: We report the results of four consecutive pediatric patients affected by anaplastic large cell lymphoma (ALCL) and treated with allogeneic stem cell transplantation from an unrelated donor. The conditioning regimen was based on total body irradiation given in association with etoposide in three patients, and with thiotepa and cyclophoshamide in one patient. Graft-vs.-host disease (GVHD) prophylaxis consisted of cyclosporin, a short course of methotrexate and rabbit antithymocyte globulin. RESULTS: All patients had rapid engraftment within 3-4 wk for neutrophils and platelets, and achieved a stable full donor chimerism that has been maintained to the last follow-up visit. One patient later developed a restrictive pneumonopathy. This patient had been heavily pretreated during the course of the disease having suffered four relapses and had received a cumulative dose of bleomycin of 160 mg/m(2). After a follow-up of 11-42 months, all patients are alive in complete hematological and molecular remission; and three of them without any chronic GVHD. CONCLUSIONS: The increasing number of volunteer bone marrow donors and the reduced toxicity of unrelated stem cell transplantation, especially in children, make this therapeutic option worth more extensive investigation in the treatment of high-risk failure ALCL, although more data is needed to evaluate the long-term benefits. In this regard, the presence of factors predictive of worst outcome such as an early relapse (within 12 months from diagnosis), a refractory or relapsing ALCL and the persistent detection on blood or bone marrow of nucleophosmin-anaplastic lymphoma kinase protein (NPM-ALK) transcript may help select the patients eligible to allogeneic related or unrelated stem cell transplantation.

Successful unrelated bone marrow transplantation for Shwachman-Diamond syndrome.

A 5-year-old boy with Shwachman-Diamond syndrome underwent unrelated HLA-identical bone marrow transplantation for severe pancytopenia. Conditioning was with busulfan, thiotepa and cyclophosphamide plus rabbit anti-lymphocyte serum. Engraftment for neutrophils and platelets was observed on days +18 and +41, respectively. Transplant-related side-effects were mild and transient. After a follow-up of 32 months, the patient is alive and enjoys a normal life, off any immunosuppressives. Immunological and hematological reconstitution is complete while other phenotypic characteristics (pancreatic insufficiency, short stature, femur dysostosis) are stable. Although experience in this field is scarce, we speculate that bone marrow failure in Shwachman-Diamond syndrome (even if not linked to the appearance of clonal disorders or leukemic transformation) is an indication for bone marrow transplantation and may be associated with a better outcome.

Aloe-emodin is a new type of anticancer agent with selective activity against neuroectodermal tumors.

Here we report that aloe-emodin (AE), a hydroxyanthraquinone present in Aloe vera leaves, has a specific in vitro and in vivo antineuroectodermal tumor activity. The growth of human neuroectodermal tumors is inhibited in mice with severe combined immunodeficiency without any appreciable toxic effects on the animals. The compound does not inhibit the proliferation of normal fibroblasts nor that of hemopoietic progenitor cells. The cytotoxicity mechanism consists of the induction of apoptosis, whereas the selectivity against neuroectodermal tumor cells is founded on a specific energy-dependent pathway of drug incorporation. Taking into account its unique cytotoxicity profile and mode of action, AE might represent a conceptually new lead antitumor drug.

Successful treatment of secondary acute myeloid leukemia relapsing after allogeneic bone marrow transplantation with donor lymphocyte infusion failed to prevent recurrence of primary disease: a case report.

We report a case of therapy-related secondary acute myeloid leukemia occurring in a patient during treatment for anaplastic large cell lymphoma. In spite of response to induction chemotherapy and prompt bone marrow transplantation from his matched sister, the patient experienced an early leukemia relapse within 3 months of the transplant. Treatment with oral etoposide for 3 weeks followed by donor lymphocyte infusion achieved a 7-month remission from leukemia without any further treatment. Unfortunately, the patient suffered a recurrence of the primary anaplastic large cell lymphoma that was treated by resuming chemotherapy and local radiotherapy. The patient died 20 months after DLI, still in CR for his leukemia, due to ALCL progression.

Autologous bone marrow transplantation for childhood acute lymphoblastic leukaemia in Italy. AIEOP/FONOP-TMO Group. Italian Association of Paediatric Haemato-Oncology.

From January 1984 to December 1994, ABMT was performed on 154 children (101 males, 53 females; median age 10, range 3-21 years) with ALL and registered for BMT by the AIEOP (Italian Association of Paediatric Haemato-Oncology). All patients were in CR: 98 were in 2nd CR and 56 were in >2nd CR. Fifteen children (9.7%) died of transplant-related mortality. Ninety-five patients (61.6%) relapsed at a median of 5 (range 1-42) months after ABMT. The 8-year EFS according to pre-BMT status was 34.6% (s.e. 4.9) for 2nd CR patients and 10.6% (s.e. 5.6) for patients in >2nd CR. By univariate analysis, site of relapse (isolated extramedullary (IE) vs BM: EFS = 68.5% vs 18.2%; P < 0.0001) and TBI containing regimen (TBI vs no TBI: EFS = 48.1 vs 15.4%; P = 0.0023) were significant factors for 2nd CR patients. When the 2nd CR subset with BM involvement was analysed, TBI became insignificant (EFS = 25.4 vs 11.8%). No factors influenced EFS in patients in >2nd CR. By multivariate analysis, site of relapse was the only significant factor in 2nd CR patients (P < 0.0001). In conclusion, ABMT is an effective treatment after one early IE relapse. Few patients can be rescued after BM relapse.

Peripheral blood stem cell collection and transplantation in paediatric malignancies: a monocentric experience.

Thirty-seven patients underwent peripheral blood stem cell (PBSC) collection from May 1994 to May 1997. Twenty-five were males and 12 were females, the median age at collection was 11.5 years (range 1-27.4) and the median weight was 38 kg (range 9-80). As mobilising chemotherapy, cyclophosphamide, etoposide, doxorubicin and cytosine arabinoside were the drugs most frequently used in association with G-CSF for a total of 47 courses. Sixty-one aphereses were performed with a median collection of CD34+ and CFU-GM cells/kg of 3.6 x 10(6) (range 0.6-31.8) and 24.4 x 10(4) (range 0.1-1260), respectively. Minimal residual disease (MRD) was found in five of the 30 investigated aphereses. Twenty-one of the 37 patients underwent high-dose chemotherapy with autologous stem cell rescue: in seven the stem cell source was peripheral blood and bone marrow. The median duration of hospitalization was 18 days for the PBSC group and 23 days for the PBSC/ABMT group. Overall survival was 78.7% at a median follow-up of 18 months (range 2-31) and the DFS was 52% without difference depending on stem cell source. Compared to a historical group of ABMT patients, the PBSC group showed a statistical advantage in terms of neutrophils and platelet engraftment, blood and platelet requirements, and length of hospitalization. PBSC collection is a feasible procedure also in the paediatric setting providing that vascular access is adequate. As already reported, PBSC transplant results in faster engraftment and shorter hospitalization that could allow a better utilization of health financial resources. The question whether the source of stem cells could influence transplant outcome would require a prospective randomised study.

Interleukin-2 before and/or after autologous bone marrow transplantation for pediatric acute leukemia patients.

The role of ABMT in the treatment of acute leukemia patients with poor prognosis is controversial because of the high risk of relapse. We attempted to obtain an anti-tumor effect by administering rIL-2 pre- and/or post-ABMT. We report our experience in 10 consecutive pediatric patients: two AML late responders and eight ALL in 2nd or subsequent CR who received ABMT and rIL-2. Five patients (group A) received rIL-2 only post-ABMT. A 120 h/week rIL-2 'induction' cycle at 6 x 10(6) IU/m2/24 h was administered by continuous intravenous infusion for 2 weeks. A further six maintenance rIL-2 cycles at 18 x 10(6) IU/m2/24 h were given 72 h/week on a monthly basis. Five patients (group B) received a single 120 h cycle of rIL-2 at 6 x 10(6)/m2/24 h before BM harvesting. Three of the five group B patients entered the same protocol described above after ABMT. Increased NK and LAK activity were documented. The cycles were well tolerated; no delayed engraftment in group B was observed. One patient in group A and two patients in group B are still in CCR, respectively 47, 42 and 15 months after ABMT. Our rIL-2 regimen; pre- and/or post-ABMT, was safely tolerated and induced significant immunomodulatory effects in pediatric patients

Recombinant interleukin 3 induces interleukin 2 receptor expression on early myeloid cells in normal human bone marrow.

Human interleukin 3 (IL-3) is a multipotential cytokine that supports the growth of early hematopoietic progenitors and promotes their response to other, later-acting cytokines. We found that IL-3 was able to induce the expression of interleukin 2 (IL-2) receptor (IL-2R) (CD25) on a subset of early myeloid cells in normal human bone marrow that had been first depleted of mature hematopoietic cells and E-rosette-positive T cells by treatment with soybean lectin and sheep erythrocytes (SBA-E-BM). Immunofluorescence analysis revealed that the CD25+ cells were contained almost entirely within the lymphoblastoid gate of the IL-3-cultured marrow. CD25 was undetectable on freshly isolated marrow and less than 10% CD25+ cells could be detected following liquid culture at 37 degrees C in the presence of 10% human serum, 10% fetal calf serum, or under serum-free conditions. Addition of IL-3 (100 U/ml) significantly increased the expression of CD25 to 37%, 31%, and 24%, respectively. CD25 could also be induced by granulocyte-macrophage colony-stimulating factor (GM-CSF), but no IL-2R was detectable following exposure to granulocyte colony-stimulating factor (G-CSF), macrophage colony-stimulating factor (M-CSF), interleukin 1 (IL-1), interleukin 4 (IL-4), or IL-2. Expression of CD25 was dependent on the dose of IL-3 or GM-CSF added and was maximal within 24 h of exposure. Two-color immunofluorescence analysis demonstrated that CD25 was not expressed by cells of lymphoid lineage or by mature monocytes, but rather was present on cells that coexpressed CD13, CD33, CD34, MY8, and HLA-DR, and that lacked CD14 or CD11b, thus placing the CD25+ cells at or near the myeloblast stage of differentiation. An identical phenotype was found for CD25+ cells induced by GM-CSF. Cycloheximide completely inhibited the IL-3-induced expression of CD25, indicating the necessity for protein synthesis, and although most of the CD25+ cells were in G0/G1 phase, 25% of the cells were in S or G2M phase, indicating that receptor expression was not cell-cycle dependent. The p75 chain of IL-2R was not detected on the CD25+ cells. IL-3 was also found to directly induce CD25 in greater than 46% of SBA-E-BM enriched for CD34+ cells by panning. Consistent with the expression of only p55 IL-2R, the functional activity of IL-2 on enriched CD34+ cells exposed to IL-3 could not be demonstrated in either granulocyte-macrophage colony-forming unit (CFU-GM) assays or proliferation assays.(ABSTRACT TRUNCATED AT 400 WORDS)