Contact interactions between epitheliocytes and fibroblasts: Formation of heterotypic cadherin-containing adhesion sites is accompanied by local cytoskeletal reorganization

Contact interactions between different cell types play a number of important roles in development, for example in cell sorting, tissue organization, and ordered migration of cells. The nature of such heterocellular interactions, in contrast to interactions between cells of the same type, remains largely unknown. In this report, we present experimental data examining the dynamics of heterocellular interactions between epitheliocytes and fibroblasts, which express different cadherin cell adhesion molecules and possess different actin cytoskeletal organizations. Our analysis revealed two striking features of heterocellular contact. First, the active free edge of an epitheliocyte reorganizes its actin cytoskeleton after making contact with a fibroblast. Upon contact with the leading edge of a fibroblast, epitheliocytes disassemble their marginal bundle of actin filaments and reassemble actin filaments into a geometric organization more typical of a fibroblast lamella. Second, epitheliocytes and fibroblasts form cell–cell adhesion structures that have an irregular organization and are associated with components of cell adhesion complexes. The structural organization of these adhesions is more closely related to the type of contacts formed between fibroblasts rather than to those between epitheliocytes. Heterotypic epithelio-fibroblastic contacts, like homotypic contacts between fibroblasts, are transient and do not lead to formation of stable contact interactions. We suggest that heterocellular contact interactions in culture may be regarded as models of how tissue systems consisting of epithelia and mesenchyme interact and become organized in vivo.

Lesion-induced reorganization in the brainstem is not completely expressed in somatosensory cortex.

Electrophysiological and neuroanatomical methods were used to determine the extent to which neonatal forelimb removal altered the organization of the cuneate nucleus and representations of the fore- and hindlimbs in the primary somatosensory cortex of adult rats. Neonatal forelimb removal resulted in invasion of the cuneate nucleus by sciatic nerve primary afferents and development of cuneothalamic projection neurons with split receptive fields that included both the hindlimb and forelimb stump. Mapping in the primary somatosensory cortex of the neonatally manipulated adult rats demonstrated abnormalities, but the major change observed in the cuneate nucleus was demonstrable at only a few (5%) cortical recording sites in the remaining stump representation and there were none at all in the hindlimb representation. These results suggest that lesion-induced brainstem reorganization may be functionally suppressed at either the thalamic or cortical level.

Highly dynamic host actin reorganization around developing Plasmodium inside hepatocytes

Plasmodium sporozoites are transmitted by Anopheles mosquitoes and infect hepatocytes, where a single sporozoite replicates into thousands of merozoites inside a parasitophorous vacuole. The nature of the Plasmodium-host cell interface, as well as the interactions occurring between these two organisms, remains largely unknown. Here we show that highly dynamic hepatocyte actin reorganization events occur around developing Plasmodium berghei parasites inside human hepatoma cells. Actin reorganization is most prominent between 10 to 16 hours post infection and depends on the actin severing and capping protein, gelsolin. Live cell imaging studies also suggest that the hepatocyte cytoskeleton may contribute to parasite elimination during Plasmodium development in the liver.

Report of the committee on the reorganization and enlargement of the University of the state of Missouri, presented to the Board of curators, at their meeting, December 20, 1870.

Mode of access: Internet.

Fifth plan on government reorganization.

Mode of access: Internet.

First plan on government reorganization.

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Referees in bankruptcy : Hearings before the special subommittee on bankruptcy and reorganization, 79th ong. 1st sess. on H.R. 33 and H.R. 3338. June 25 and 26, 1945. Serial no. 4.

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Railroad reorganization : Hearing before the Special subcommittee on bankruptcy and reorganization of the Committee on the judiciary, House of representatives, seventy-sixth Congress, first session on S. 1869; an act to protect interstate commerce from the dangers of unsound financial structures and to establish improved procedures and standards for financial rehabilitation of railroads engaged in interstate commerce, and for other purposes.

Serial no. 11.

Rome and the world today; a study, in comparison with present conditions, of the reorganization of civilization under the Roman empire which brought to a war-worn world two hundred years of peace,

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Reorganization plan no. 1 of 1953 (H. J. Res. 223) : hearings before the Subcommittee on Reorganization of the Committee on Government Operations, United States, Eighty-third Congress, first session, on Reorganization plan no. 1 of 1953 and H. J. Res. 223. March 23, 1953.

Margaret Chase Smith, chairman of subcommittee.

Reorganization of commercial education in public high schools,

"Results of state wide investigation of commercial education in the public high schools of Minnesota ... 1927."--Acknowledgments.