Spin-Glass State in CuGa2O4\rm CuGa_2O_4

Magnetic susceptibility, magnetization, specific heat and positive muon spin relaxation (\musr) measurements have been used to characterize the magnetic ground-state of the spinel compound $\rm CuGa_2O_4$. We observe a spin-glass transition of the S=1/2 $\rm Cu^{2+}$ spins below $\rm T_f=2.5K$ characterized by a cusp in the susceptibility curve which suppressed when a magnetic field is applied. We show that the magnetization of $\rm CuGa_2O_4$ depends on the magnetic histo Well below $\rm T_f$, the muon signal resembles the dynamical Kubo-Toyabe expression reflecting that the spin freezing process in $\rm CuGa_2O_4$ results Gaussian distribution of the magnetic moments. By means of Monte-Carlo simulati we obtain the relevant exchange integrals between the $\rm Cu^{2+}$ spins in this compound.Comment: 6 pages, 16 figure

Conversion of an IGM secreting immunocytoma in a high grade malignant lymphoma of immunoblastic type - A case report.

A case involving a 67 year old man with an immunocytoma initially presenting as Waldenström's macroglobulinemia which transformed into a high grade malignant lymphoma of immunoblastic type after treatment with cyclophosphamide and corticosteroids over 5 months is presented. IgM (kappa) present in the serum in the phase of immunocytoma was demonstrated also on the less differentiated cells of the high grade lymphoma. The permanent production of the same immunoglobuline molecule suggests that both morphologically different malignancies derived from one B cell clone

Protein synthesis in the blood lymphocytes of chronic lymphocytic leukemia and its relationship to prognosis.

Protein synthesis primed by endogenous messenger RNA (mRNA) as well as polyuridylic acid-[poly (U)] directed polyphenylalanin synthesis was measured in extracts of blood lymphocytes from a series of 50 chronic lymphocytic leukemia (CLL) patients and compared with the prognostic stage. Patients were clinically classified according to the new international workshop classification [4]. There were 23 patients at stage A, 14 at stage B and 13 at stage C. Extracts from patients of the high risk group (stage C), defined by anemia and/or thrombocytopenia, exhibited a significantly higher poly (U)-translation activity than extracts from low and intermediate risk patients-stages A and B-(P<0.01). This finding has a sensitivity of 62% but a specifity of 100%. During follow-up, an increase of poly (U)-translation and endogenous protein synthesis was observed after changing from stages A or B to stage C. Activity of protein synthesis could neither be correlated with proliferation activity, as measured by lymphocyte doubling time, nor with the expression of immunologic surface markers, nor with serum immunoglobuline (Ig) levels