Evidence for spin-dependent energy transport in a superconductor.

In ferromagnetic materials, spin up and down electrons can carry different heat currents. This spin-dependent energy excitation mode ('spin energy mode') occurs only when spin up and down energy distribution functions are different. In superconductors, heat is carried by quasiparticle excitations and the spin energy mode can be excited by spin-polarised current injection. In the presence of a finite Zeeman magnetic field, the spin energy mode surprisingly leads to a charge imbalance (different numbers of hole- and electron-like quasiparticles) at the superconducting gap edge. By performing spin-resolved spectroscopy of the out-of-equilibrium quasiparticle populations in a mescoscopic superconductor, we reveal that their distribution functions are non-Fermi-Dirac. In addition, our spectroscopic technique allows us to observe a charge imbalance, localised in energy to the gap edge and thus unambiguously identify the spin energy mode. Our results agree well with theory and shed light on energy transport in superconducting spintronics.

A rare case report of autoimmune haemolytic anemia in a female child due to a Donath-Landsteiner antibody.

Paroxysmal cold hemoglobinuria is a rare form of autoimmune hemolytic anemia caused by the Donath-Landsteiner autoantibody. The condition is characterized by the presence of an IgG biphasic hemolysin with specificity to the P blood group antigen. The antibody biphasic action may be demonstrated in the Donath-Landsteiner test. While paroxysmal cold hemoglobinuria can be manifested at any age, it typically appears in children following a viral upper respiratory syndrome or immunization, though rarely. This report describes a 23-months old girl presented with 5 days history of fever, erythrocytopenia, leukocytosis and occurrence of dark urine. On admission, the physical examination showed pallor, no scleral icterus, a mild hyperemic throat and no hepatosplenomegaly. The investigations revealed severe anemia with hemoglobin of 44g/L, increased reticulocyte count (10.67%), elevated lactate dehydrogenase (2603IU/L), decreased serum haptoglobin (0.159g/L), normal G6PD. Direct antiglobulin test was positive with C3d and C3c complement components only. Direct and indirect Donath-Landsteiner tests were positive. The girl was treated with a intravenous immunoglobulin infusion and Cefotaxime. She received transfusion of red blood cells, crossmatched, although P antigen untyped. Despite this in vitro serological incompatibility she had a hemoglobin increase. The patient was discharged in stable condition on the seventh day following admission. Paroxysmal cold hemoglobinuria is a hemolytic anemia for which a specific diagnostic test is available. Timely recognition of the disease by pediatricians is crucial as well as the highly skilled hospital blood bank staff performing Donath-Landsteiner testing.

Shared effects of organic microcontaminants and environmental stressors on biofilms and invertebrates in impaired rivers.

Land use type, physical and chemical stressors, and organic microcontaminants were investigated for their effects on the biological communities (biofilms and invertebrates) in several Mediterranean rivers. The diversity of invertebrates, and the scores of the first principal component of a PCA performed with the diatom communities were the best descriptors of the distribution patterns of the biological communities against the river stressors. These two metrics decreased according to the progressive site impairment (associated to higher area of agricultural and urban-industrial, high water conductivity, higher dissolved organic carbon and dissolved inorganic nitrogen concentrations, and higher concentration of organic microcontaminants, particularly pharmaceutical and industrial compounds). The variance partition analyses (RDAs) attributed the major share (10%) of the biological communities' response to the environmental stressors (nutrients, altered discharge, dissolved organic matter), followed by the land use occupation (6%) and of the organic microcontaminants (2%). However, the variance shared by the three groups of descriptors was very high (41%), indicating that their simultaneous occurrence determined most of the variation in the biological communities.

Epstein-Barr virus-associated haemophagocytic lymphohistiocytosis in Wiskott-Aldrich syndrome.

UNLABELLED: A patient with Wiskott-Aldrich syndrome who developed Epstein-Barr virus-associated haemophagocytic lymphohistiocytosis (EBV-HLH) is described in this study. At 4 mo of age the patient developed fever associated with bicytopenia and splenomegaly. Analysis of a bone marrow specimen revealed extensive haemophagocytosis, and in situ hybridization for EBV of the bone marrow specimen using an EBV-encoded RNA probe was positive. Diagnosis of EBV-HLH was established and immunotherapy with HLH-94 protocol was started. HLH has been described in patients with other well-defined primary immunodeficiencies such as X-linked lymphoproliferative syndrome, Chediak-Higashi syndrome and Griscelli disease. Also, HLH was reported recently in severe combined immunodeficiency and DiGeorge syndrome. CONCLUSION: The possibility of an underlying primary immunodeficiency should be considered in paediatric patients who present with HLH during infancy.

[Primary myelodysplastic syndrome in children]. / Sindrom primarne mijelodisplazije kod dece.

Primary MDS is a group of heterogenous clonal haematopoetic disorders. In a third of patients MDS terminates as acute myeloid leukaemia, usually resisitant to treatment, while the others succumb due to infections and haemorrhage. Conservative managements of MDS (chemotherapy, haematopoetic growth factors, modulation of cytokine network) are unsuccessful, while the bone marrow transplantation is the only definite treatment. We reviewed clinical and haematological presentations, frequency of dysplastic features, histological and cytogenetic findings in 29 children with primary MDS. Indications for haematological evaluation in our patients were symptoms and signs of isolated or combined cytopenias, fever of unknown origin and frequent infections. Hepatosplenomegaly was found in 19 (65%) patients, while this pattern was found in 10% of adult patients. Normochromic anaemia was found in 25 (86%) patients and thrombocytopenia in 23 (76%). Patients presenting pancytopenia had the lowest probability of survival. Degree of dysplasia, histology and kariotype of bone marrow had no influence on survival rates. Prognostic factors in paediatric MDS are of limited significance, as MDS in children is an absolute indication for bone marrow transplantation.

Glomerular involvement in myelodysplastic syndromes.

Several reports have documented various forms of glomerular diseases in adults with myelodysplastic syndromes (MDS), but similar reports in children are lacking. We describe two children with MDS-associated steroid-responsive nephrotic syndrome (NS). Patient 1, who had MDS with myelofibrosis, presented with hepatosplenomegaly, pancytopenia, chronic hepatitis, moderate proteinuria, hypocomplementemia and elevated ANA titer. During initial prednisone treatment proteinuria markedly diminished and partial but transient hematological improvement occurred. Relapse subsequently occurred that manifested by overt NS and pancytopenia. High doses of prednisolone led to remission of the renal disease, but hematological remission did not occur. Persisting pancytopenia and repeated infections terminated in sepsis, 2 years after the onset of the MDS. Patient 2, who had refractory anemia with clonal monosomy 19, presented with bowel disease, hepatosplenomegaly, anemia and non-organ-specific autoantibodies. Prednisone led to both clinical and hematological remission. The hematologic disease relapsed 12 months later, when nephrotic-range proteinuria, hematuria and mild azotemia were also found. Corticosteroid treatment led to long-lasting renal and hematologic remission, maintained by a small dosage of prednisone. In both patients, renal biopsy findings were consistent with those seen in idiopathic NS. A Medline search disclosed 16 cases of glomerulopathy in the course of MDS in adult patients. Clinical features included NS, usually accompanied by renal insufficiency with acute, chronic, or rapidly progressive glomerulonephritis. On biopsy, membranous nephropathy, crescentic or mesangial proliferative glomerulonephritis, and AL amyloidosis were found. We conclude: (1) that glomerular disease may be present and should be searched for in patients with MDS and (2) that MDS can be added to the list of rare conditions associated with corticosteroid-responsive NS in children.