High-magnetic field lattice length changes in URu2Si2

We report high magnetic field (up to 45 T) c-axis thermal expansion and magnetostriction experiments on URu2Si2 single crystals. The sample length change associated with the transition to the hidden order phase becomes increasingly discontinous as the magnetic field is raised above 25 T. The re-entrant ordered phase III is clearly observed in both the thermal expansion and magnetostriction above 36 T, in good agreement with previous results. The sample length is also discontinuous at the boundaries of this phase, mainly at the upper boundary. A change in the sign of the coefficient of thermal-expansion is observed at the metamagnetic transition (B_M = 38 T) which is likely related to the existence of a quantum critical end point.Comment: 5 pages, 4 figures, to be published in PR

Growth hormone (GH)‐induced reconstitution of CD8+ CD28+ T lymphocytes in a rare case of severe lymphopenia associated with Juvenile Haemochromatosis and Turner's syndrome.

Clin Endocrinol (Oxf). 2004 Oct;61(4):437-40. Growth hormone (GH)-induced reconstitution of CD8+ CD28+ T lymphocytes in a rare case of severe lymphopenia associated with Juvenile Haemochromatosis and Turner's syndrome. Porto G, Cruz E, Miranda HP, Porto B, Vasconcelos JC, Lacerda R, Roetto A, Daraio F, Bacelar C. Santo António General Hospital, Porto, Portugal. [email protected] Abstract This paper describes a rare case of Turner's syndrome associated with Juvenile Haemochromatosis and severe lymphopenia, followed-up for a period of 5 years. Because of the indication for treatment with growth hormone (GH), this case was observed as a model to analyse the effects of GH on growth, iron mobilization and lymphocyte reconstitution. For this purpose, a serial study of the T lymphocyte subpopulations CD4+, CD8+, CD8+ CD28+ and CD8+ CD28- was performed by immunophenotyping during the follow-up period. Besides the impact of both phlebotomy treatment and GH on the rapid growth and mobilization of 20.8 g of iron in 136 weeks, the most relevant observation was the finding of a significant expansion of CD8+ T lymphocytes expressing the costimulatory marker CD28 in the setting of the severe lymphopenia. These findings constitute new clinical evidence supporting the notion that the GH/IGF-1 system has an important role on the maintenance of T cell homeostasis in vivo, and that GH may be regarded as a putative therapeutic agent in T lymphocyte reconstitution. PMID: 15473875 [PubMed - indexed for MEDLINE