Mohammed El-Shahat

The International Network of Cancer Treatment and Research (INCTR) recently organized a workshop on non-Hodgkin lymphomas (NHLs) in selected developing countries with the purpose of examining existing information relating to the pathology and management of these neoplasms, and identifying potential areas for research. This report provides a summary of the information presented and is focused primarily on the pathology of NHLs in children and adults. In most countries, the WHO classification of lymphomas was used and most participating centers included immunohistochemistry using a wide array of lymphoid antibodies as part of routine diagnosis. Some of the series had been reviewed by an external panel of experts. B-cell lymphomas accounted for 82-88% of all NHLs. The proportions of chronic lymphatic leukemia (4-6%), mantle cell lymphoma (MCL, 3-5%), and plasmacytoma (2-4%) were similar in the series presented. However, there was a significant variation in the proportion of follicular lymphoma (FL), which accounted for 15% and 11% in India and Kuwait, but less than 5% in Pakistan and Egypt. All of these frequencies are significantly lower than those reported in Western series. Diffuse large B-cell lymphoma accounted for about 35% of cases in India but for more 50% in other countries, but this difference was not accounted for by an increased incidence in a single lymphoma subtype in India, but rather an apparent paucity of several subtypes (such as mantle cell and marginal zone lymphomas (MZL)) in other series. There were relatively high frequencies of Burkitt lymphoma in Egypt (7%) and precursor T-cell lymphoblastic lymphoma in India (6-7%). Peripheral T-cell lymphomas (PTCLs) (not otherwise specified and angioimmunoblastic subtypes) accounted for 3-5% of NHLs, and extranodal lymphoma of T/NK cell type was rare (<1%). These differences in the relative proportions of NHL subtypes among developing countries and between developing countries and the rest of the world presumably arise from differences in environmental and genetic factors that influence lymphomagenesis and strongly suggest that more research in developing countries would provide valuable insights into the pathogenesis of lymphoid neoplasms.

The International Network of Cancer Treatment and Research (INCTR) recently organized a workshop on non-Hodgkin lymphomas (NHLs) in selected developing countries with the purpose of examining existing information relating to the pathology and management of these neoplasms, and identifying potential areas for research. This report provides a summary of the information presented and is focused primarily on the pathology of NHLs in children and adults. In most countries, the WHO classification of lymphomas was used and most participating centers included immunohistochemistry using a wide array of lymphoid antibodies as part of routine diagnosis. Some of the series had been reviewed by an external panel of experts. B-cell lymphomas accounted for 82-88% of all NHLs. The proportions of chronic lymphatic leukemia (4-6%), mantle cell lymphoma (MCL, 3-5%), and plasmacytoma (2-4%) were similar in the series presented. However, there was a significant variation in the proportion of follicular lymphoma (FL), which accounted for 15% and 11% in India and Kuwait, but less than 5% in Pakistan and Egypt. All of these frequencies are significantly lower than those reported in Western series. Diffuse large B-cell lymphoma accounted for about 35% of cases in India but for more 50% in other countries, but this difference was not accounted for by an increased incidence in a single lymphoma subtype in India, but rather an apparent paucity of several subtypes (such as mantle cell and marginal zone lymphomas (MZL)) in other series. There were relatively high frequencies of Burkitt lymphoma in Egypt (7%) and precursor T-cell lymphoblastic lymphoma in India (6-7%). Peripheral T-cell lymphomas (PTCLs) (not otherwise specified and angioimmunoblastic subtypes) accounted for 3-5% of NHLs, and extranodal lymphoma of T/NK cell type was rare (<1%). These differences in the relative proportions of NHL subtypes among developing countries and between developing countries and the rest of the world presumably arise from differences in environmental and genetic factors that influence lymphomagenesis and strongly suggest that more research in developing countries would provide valuable insights into the pathogenesis of lymphoid neoplasms.

Four groups of the series of rare earth ferrite Li0.5+zCo zRxFe2.5-2z-xO4;z=0.1, (x=0.0,0.025,0.05,⋯,⋯ and 0.2) and R is Dy were prepared using the standard ceramic technique at sintering temperatures 1373, 1423, 1473 and 1523 K. The magnetic parameters were calculated from the measurement of the magnetic susceptibility in the temperature range (300-900 K) using Faraday's method at five different magnetic field intensities of (1275-2922 Oe). The obtained data for the Curie temperature (TC) and the effective magnetic moment (μeff) clarify that the suitable sintering temperature was 1473 K and the critical dysprosium content was x=0.075. The appearance of hysteresis loop in the ferromagnetic region of the relation of magnetic susceptibility vs. temperature during the heating and cooling of two runs is interpreted in view of the thermal energy that disturbs the aligned magnetic dipoles. © 2004 Elsevier B.V. All rights reserved.

Four groups of the series of rare earth ferrite Li0.5+zCo zRxFe2.5-2z-xO4;z=0.1, (x=0.0,0.025,0.05,⋯,⋯ and 0.2) and R is Dy were prepared using the standard ceramic technique at sintering temperatures 1373, 1423, 1473 and 1523 K. The magnetic parameters were calculated from the measurement of the magnetic susceptibility in the temperature range (300-900 K) using Faraday's method at five different magnetic field intensities of (1275-2922 Oe). The obtained data for the Curie temperature (TC) and the effective magnetic moment (μeff) clarify that the suitable sintering temperature was 1473 K and the critical dysprosium content was x=0.075. The appearance of hysteresis loop in the ferromagnetic region of the relation of magnetic susceptibility vs. temperature during the heating and cooling of two runs is interpreted in view of the thermal energy that disturbs the aligned magnetic dipoles. © 2004 Elsevier B.V. All rights reserved.