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The large-scale laminar/turbulent spiral patterns that appear in the linearly unstable regime of counter-rotating Taylor-Couette flow are investigated from a statistical perspective by means of direct numerical simulation. Unlike the vast majority of previous numerical studies, we analyse the flow in periodic parallelogram-annular domains, following a coordinate change that aligns one of the parallelogram sides with the spiral pattern. The domain size, shape and spatial resolution have been varied and the results compared with those in a sufficiently large computational orthogonal domain with natural axial and azimuthal periodicity. We find that a minimal parallelogram of the right tilt significantly reduces the computational cost without notably compromising the statistical properties of the supercritical turbulent spiral. Its mean structure, obtained from extremely long time integrations in a co-rotating reference frame using the method of slices, bears remarkable similarity with the turbulent stripes observed in plane Couette flow, the centrifugal instability playing only a secondary role. This article is part of the theme issue 'Taylor-Couette and related flows on the centennial of Taylor's seminal Philosophical transactions paper (Part 2)'.

Background: Paediatric diffuse alveolar haemorrhage (DAH) is a rare heterogeneous condition with limited knowledge on clinical presentation, treatment and outcome., Methods: A retrospective, descriptive multicentre follow-up study initiated from the European network for translational research in children's and adult interstitial lung disease (Cost Action CA16125) and chILD-EU CRC (the European Research Collaboration for Children's Interstitial Lung Disease). Inclusion criteria were DAH of any cause diagnosed before the age of 18 years., Results: Data of 124 patients from 26 centres (15 counties) were submitted, of whom 117 patients fulfilled the inclusion criteria. Diagnoses were idiopathic pulmonary haemosiderosis (n=35), DAH associated with autoimmune features (n=20), systemic and collagen disorders (n=18), immuno-allergic conditions (n=10), other childhood interstitial lung diseases (chILD) (n=5), autoinflammatory diseases (n=3), DAH secondary to other conditions (n=21) and nonspecified DAH (n=5). Median (IQR) age at onset was 5 (2.0-12.9) years. Most frequent clinical presentations were anaemia (87%), haemoptysis (42%), dyspnoea (35%) and cough (32%). Respiratory symptoms were absent in 23%. The most frequent medical treatment was systemic corticosteroids (93%), hydroxychloroquine (35%) and azathioprine (27%). Overall mortality was 13%. Long-term data demonstrated persistent abnormal radiology and a limited improvement in lung function., Conclusions: Paediatric DAH is highly heterogeneous regarding underlying causes and clinical presentation. The high mortality rate and number of patients with ongoing treatment years after onset of disease underline that DAH is a severe and often chronic condition. This large international study paves the way for further prospective clinical trials that will in the long term allow evidence-based treatment and follow-up recommendations to be determined., Competing Interests: Conflicts of interest: T. Bandeira reports personal fees from Sanofi and other support from Boehringer Ingelheim, outside the submitted work. Conflicts of interest: E.D. Manali reports other from Boehringer Ingelheim, other from Bering, other from Hoffman la Roche, outside the submitted work. Conflicts of interest: S. Papiris reports grants and other support from Boehringer Ingelheim and Hoffman la Roche, and other support from Savara, outside the submitted work. Conflicts of interest: M. Griese reports grants, personal fees and nonfinancial support from Boehringer Ingelheim for an advisory board on nintedanib, outside the submitted work. Conflicts of interest: The remaining authors have nothing to disclose., (Copyright ©The authors 2023.)

Background: In most cases, severe asthma in children has an allergic etiology, but allergen-specific immunotherapy (AIT) is contraindicated., Objective: This study aimed at analyzing the safety and efficacy of AIT in patients with severe asthma treated with omalizumab (OM)., Methods: A descriptive real-life study was carried out by reviewing medical records. Effectiveness was measured by the degree of control (CAN questionnaire), number of hospitalizations per year, number of exacerbations per year, and maintenance treatment and lung function (FEV1). Some adverse reactions occurred (AAI-EAACI-WAO guidelines)., Results: The retrospective study included 29 patients up to 18 years of age with severe asthma with OM plus AIT treatment. AIT treatment was started in a cluster schedule when patients treated with OM achieved disease control. Before starting AIT, patients were treated with OM for 1 year for achieving asthmatic control. AIT to mites (51%), Alternaria (37.9%), or pollens (10.3%) was administered. After one year with OM plus AIT,statistically significant differences in CAN scores and FEV1 measures were observed (P < 0.001). No patients under treatment with OM plus AIT required hospital admission. During the clustering schedule, only 3/64 doses showed systemic adverse reactions. During the AIT maintenance treatment, 348 doses were administered, with no significant adverse reactions., Conclusion: In this population-based study in children with severe asthma, the combined treatment with OM plus AIT was safe and effective. This strategy allows these pediatric patients to be safely treated with AIT.

Background: Children's diffuse lung disease, also known as children's Interstitial Lung Diseases (chILD), are a heterogeneous group of rare diseases with relevant morbidity and mortality, which diagnosis and classification are very complex. Epidemiological data are scarce. The aim of this study was to analyse incidence and prevalence of chILD in Spain., Methods: Multicentre observational prospective study in patients from 0 to 18 years of age with chILD to analyse its incidence and prevalence in Spain, based on data reported in 2018 and 2019., Results: A total of 381 cases with chILD were notified from 51 paediatric pulmonology units all over Spain, covering the 91.7% of the paediatric population. The average incidence of chILD was 8.18 (CI 95% 6.28-10.48) new cases/million of children per year. The average prevalence of chILD was 46.53 (CI 95% 41.81-51.62) cases/million of children. The age group with the highest prevalence were children under 1 year of age. Different types of disorders were seen in children 2-18 years of age compared with children 0-2 years of age. Most frequent cases were: primary pulmonary interstitial glycogenosis in neonates (17/65), neuroendocrine cell hyperplasia of infancy in infants from 1 to 12 months (44/144), idiopathic pulmonary haemosiderosis in children from 1 to 5 years old (13/74), hypersensitivity pneumonitis in children from 5 to 10 years old (9/51), and scleroderma in older than 10 years old (8/47)., Conclusions: We found a higher incidence and prevalence of chILD than previously described probably due to greater understanding and increased clinician awareness of these rare diseases., (Copyright © 2021 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.)

The effectiveness of antiplatelet therapy as primary prophylaxis for thrombosis in low-risk essential thrombocythemia (ET) is not proven. In this study, the incidence rates of arterial and venous thrombosis were retrospectively analyzed in 300 low-risk patients with ET treated with antiplatelet drugs as monotherapy (n = 198) or followed with careful observation (n = 102). Follow-up was 802 and 848 person-years for antiplatelet therapy and observation, respectively. Rates of thrombotic events were 21.2 and 17.7 per 1000 person-years for antiplatelet therapy and observation, respectively (P = .6). JAK2 V617F-positive patients not receiving antiplatelet medication showed an increased risk of venous thrombosis (incidence rate ratio [IRR]: 4.0; 95% CI: 1.2-12.9; P = .02). Patients with cardiovascular risk factors had increased rates of arterial thrombosis while on observation (IRR: 2.5; 95% CI: 1.02-6.1; P = .047). An increased risk of major bleeding was observed in patients with platelet count greater than 1000 x 10(9)/L under antiplatelet therapy (IRR: 5.4; 95% CI: 1.7-17.2; P = .004). In conclusion, antiplatelet therapy reduces the incidence of venous thrombosis in patients with JAK2-positive ET and the rate of arterial thrombosis in patients with associated cardiovascular risk factors. In the remaining low-risk patients, this therapy is not effective as primary prophylaxis of thrombosis, and observation may be an adequate option.

Even in the era of newer and sophisticated prognostic markers, beta(2)-microglobulin (B2M) remains a simple but very powerful predictor of treatment-free survival (TFS) and overall survival (OS) in patients with chronic lymphocytic leukaemia (CLL). However, B2M levels are heavily influenced by the patient's glomerular filtration rate (GFR) and this study aimed to evaluate whether GFR-adjusted B2M (GFR-B2M) had improved prognostic value compared to unadjusted B2M in a cohort of over 450 consecutive CLL patients from two separate institutions. Multivariate analysis identified a significantly shorter TFS in patients who were ZAP-70 + (P < 0.001), with increased GFR-B2M (P < 0.001), and del(11q) or del(17p) as detected by fluorescence in situ hybridization (FISH; P < 0.001). When OS was evaluated by multivariate analysis, age 65 years or older (P < 0.001) and poor risk FISH abnormalities (P < 0.001) had a confirmed adverse prognostic impact, but the predictive value of GFR-B2M was lost in the validation analysis. In all survival models, B2M did not attain independent significance unless GFR-B2M was eliminated from the analysis. In conclusion, GFR-B2M is a better predictor of TFS than unadjusted B2M in CLL patients.

Cultivated murine bone marrow mesenchymal stem cells (MSCs) frequently accumulate chromosome abnormalities, become oncogenically transformed, and generate sarcomas when transplanted in mice. Although human MSCs appear to be more resistant, oncogenic transformation has also been observed in MSCs cultivated past the senescence phase. Cell therapy for tissue regeneration using human autologous MSCs requires transplantation of cells previously expanded in vitro. Thus, an important concern is to determine if oncogenic transformation is a necessary outcome of the expansion procedures. We have analyzed the proliferation capacity, organ colonization, and oncogenicity of enhanced green fluorescent protein and luciferase-labeled human adipose tissue-derived mesenchymal stem cells (hAMSCs), implanted in immunocompromised mice during a prolonged time period (8 months) using a non-invasive bioluminescence imaging procedure. Our data indicates that the liver was the preferred target organ for colonization by intramuscular or intravenous implantation of hAMSCs. The implanted cells tended to maintain a steady state, population did not proliferate rapidly after implantation, and no detectable chromosomal abnormalities nor tumors formed during the 8 months of residence in the host's tissues. It would appear that hAMSCs, contrary to their murine correlatives, could be safe candidates for autologous cell therapy procedures since in our experiments they show undetectable predisposition to oncogenic transformation after cultivation in vitro and implantation in mice.

Background and Objectives: The terms acute erythroleukemia and AML-M6 are defined in the FAB classification as proliferations of dysplastic erythroid elements mixed with blasts of myeloid origin, but pure erythroid leukemias are not included. The recent WHO classification has a category of acute myeloid leukemia not otherwise categorized, which includes acute erythroid leukemia (M6) of two subtypes: M6a-erythroleukemia (erythroid/myeloid) and M6b-pure erythroid leukemia. The aims of this co-operative study were to discover the incidences of these different subtypes, and pay special attention to the morphology of these entities., Design and Methods: We reviewed a series of 62 patients with erythroid neoplastic proliferations. Previous medical history, age, sex, peripheral blood and bone marrow cell counts, cytochemical stains, immunophenotype, and cytogenetics were evaluated at presentation. We analyzed the incidence of erythrocyte, leukocyte and platelet abnormalities in the peripheral blood. In bone marrow we analyzed dysplastic features of erythroblasts, granulocytic elements and the megakaryocytic lineage., Results: Fifty-three patients met the criteria of M6a subtype of the WHO classification, and 2 were classified as having pure erythremia (M6b); 7 cases could not be classified according to the WHO criteria. Fifty-five patients presented with de novo acute leukemia, and seven patients had secondary acute leukemia. The most frequent dysplastic features in blood smears were: schistocytes, tear-drop and pincered cells in erythrocytes; hypogranulation and hyposegmentation in leukocytes; gigantism and hypogranulation in platelets. In bone marrow, megaloblastic changes, multinuclearity, karyorrhexis and basophilic stippling in erythroblasts; hypogranulation and gigantism in granulocytic series, and micromegakaryocytes and unconnected nuclei in megakarocytes were the most dysplastic features. A positive PAS reaction and increase of bone marrow iron with ring sideroblasts were common features. Trilineage dysplasia was present in 54% of cases. Dysplastic features in granulocytic elements were absent in 26% of patients and minimal erythroblastic dysplasia was observed in seven patients. A complex karyotype was seen in 27% of patients; chromosomes 5 and 7 were the most frequently involved., Interpretation and Conclusions: De novo acute erythroid leukemia was more frequent than secondary cases in our series. The most frequent type of acute erythroid proliferation was the WHO M6a subtype and the least the pure erythroid leukemia. We found a group of seven patients (11%) who could not be classified according to the WHO criteria. Morphologic findings of erythrocytes in peripheral blood, such as schistocytes, tear-drop and pincered cells, were outstanding features. Morphologic aspects remain one of the most important tools for diagnosing these entities.

Background and Objective: Thrombocytopenia of peripheral origin is basically due to platelet destruction or splenic sequestration. Thrombopoietin (TPO) regulates platelet production stimulating megakaryocyte proliferation and maturation. The evaluation of TPO levels may be a useful tool in the diagnosis of thrombocytopenias of unknown origin. We tried to determine the value of TPO levels in some thrombocytopenias classically considered as peripheral., Design and Methods: Serum TPO levels and platelet counts were measured in 32 thrombocytopenic patients with liver cirrhosis (LC) and 23 with chronic hepatitis C (CHC) viral infection, in 54 patients with a clinical and serological diagnosis of autoimmune thrombocytopenic purpura (AITP), and in 88 patients infected with the human immunodeficiency virus (HIV)., Results: Patients with LC, AITP and HIV had lower platelet counts than patients with CHC. The degree of thrombocytopenia did not, however, correlate with the TPO levels. HIV infected patients (246+/-304 pg/mL) and AITP patients (155+/-76 pg/mL) had higher TPO levels than controls (121+/-58 pg/mL). TPO levels in patients with CHC (125+/-40 pg/mL) did not differ from those in control subjects, but were slightly decreased in patients with LC (104+/-56 pg/mL)., Interpretation and Conclusions: Reduced TPO production could be involved in the development of thrombocytopenia in LC patients, but not in patients with early stages of CHC viral infection. HIV and AITP patients had slightly raised levels of TPO. As TPO levels are normal or slightly increased in most peripheral thrombocytopenias, these data alone are not sufficient to distinguish the different types of peripheral thrombocytopenia. They may, however, be a useful tool for differentiating some central and peripheral thrombocytopenias.

A new case of thymoma, myasthenia gravis and pure red cell aplasia is presented. Pure red cell aplasia came out 10 years after the diagnosis of the two other diseases in one of several relapses of metastatic thymoma with clinical signs of myasthenia. Surgery, chemotherapy and radiotherapy besides pyridostigmine treatment were used in the clinical course of the patient. A phenotypical change of medullary T lymphocytes (CD4 to CD8) was observed at the same time of pure red cell aplasia diagnosis. A dual role of medullary CD2+ T cell lymphocytes, stimulant and suppressive, over erythroid progenitor cells (BFU-E and CFU-E) was suggested by in vitro cultures.

Seven patients with relapsed acute leukemia (4 ANLL, 3 ALL) and one with juvenile chronic myelomonocytic leukemia (JCMML) received a second BMT (BMT2). Patients were conditioned with CY/TBI (n = 7) or BU/CY (n = 1) for the first BMT (BMT1), with adequate recovery in all and without the appearance of acute GVHD (n = 3) or with mild forms (grade I, n = 2; grade II, n = 3). Relapse after BMT1 occurred in < 6 months (n = 2), between 6 and 12 months (n = 5) and > 12 months (n = 1), and the interval from BMT1 to BMT2 was < 6 months (n = 1), from 6 to 12 months (n = 5) or > 12 months (n = 2). Conditioning for BMT2 was done in untreated relapse and included combinations of BU/CY (n = 2), CY/TBI (n = 1) or BU 1 mg/kg at intervals of 6 h by mouth on days -7 to -4 and melphalan 180 mg/m2 i.v. on day -2, with the addition of VP-16 in the patient with JCMML. Two patients died on day +11 with no evidence of residual leukemia at autopsy. Six patients engrafted, one of whom had an uneventful BMT2, but he relapsed 6 months later. The other five developed severe acute GVHD (grades III-IV), with a fatal outcome in three cases, while two responded to treatment and are currently alive in continuous CR at 12 and 36 months. All patients had received conventional prophylaxis against acute GVHD.(ABSTRACT TRUNCATED AT 250 WORDS)

Human long-term bone marrow cultures allow persistence of hematopoietic stem cells in vitro for several weeks. Abnormalities in these cultures have been observed after cell treatment for purging in vitro. In autologous transplantation trials an increase in grafting failures after purging has also been reported. These results suggest a correlation between culture behaviour and graft kinetics. We analyzed the pattern of growth in Dexter culture of the bone marrow fraction infused in 52 patients with malignant diseases and subjected to autologous transplantation. In 23 cases, bone marrow cells had previously been treated in vitro with Asta-Z 7654 (n = 7) or with monoclonal antibodies plus complement (n = 16). Some of the long-term bone marrow culture parameters seemed to correlate with grafting kinetics, mainly adherent cell layer development and persistence of committed hematopoietic progenitors (CFU-GM) in the supernatant cells. The absence of a stromal layer defined a group with very poor hematological recovery after transplantation. Nine cases were included in this group and only one patient (11%) had recovered granulocytes and platelets. However, 90% of patients whose long-term cultures displayed normal adherent cell behavior had recovered peripheral hematological values. These results suggest that long-term bone marrow cultures could be used as a prognostic factor for hematopoietic reconstitution in autologous transplantation.