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PubMed1991

Differential migration of T and B cells during an acute inflammatory response.

Inflammation in the liver and mammary glands of sheep caused by challenge infection with Taenia hydatigena or infusion of killed Staphylococcus aureus, respectively were characterized by the recruitment of both T and B cells. The patterns of migration of these two major lymphocyte subpopulations were distinctly different. While T cells seemed to migrate out of existing, flat endothelium-lined blood vessels resulting in a diffuse distribution at the sites of inflammation, B cells were characteristically present as clusters of tightly packed cells at restricted sites in the inflamed tissue. Within these B cell clusters distinct capillary vessels lined with plumb endothelial cells were always present suggesting that they were the sites of intense migration of B cells originating from the draining lymph nodes. These results indicate differential regulation of adhesion molecules on B and T cells and/or their ligands on endothelium during acute inflammatory reactions.

Acute-Phase Reaction↗
PubMed1986

[Migration in Austria: 1850-1900. Migration flows within the monarchy and the structure of migration to Vienna].

The author surveys migration within the Austrian part of the Austro-Hungarian Empire from 1850 to 1900 using census data. "As a result of the increase in regional mobility during the nineteenth century, clearly defined patterns of migration developed involving movement from the peripheral areas to the center.... In the process of this development, various sub-systems of migration appeared. Of these, migration from one region to another was more important than that within the same region...and Vienna, the Imperial capital, became the center of migration." Migrants are studied by place of origin and distance traveled and by social class and demographic characteristics. Employment, segregation, and the integration of urban migrants are also considered. (SUMMARY IN ENG)

Acculturation↗
PubMed2006

Intestinal coelomic transplants: a novel method for studying enteric nervous system development.

Normal development of the enteric nervous system (ENS) requires the coordinated activity of multiple proteins to regulate the migration, proliferation, and differentiation of enteric neural crest cells. Much of our current knowledge of the molecular regulation of ENS development has been gained from transgenic mouse models and cultured neural crest cells. We have developed a method for studying the molecular basis of ENS formation complementing these techniques. Aneural quail or mouse hindgut, isolated prior to the arrival of neural crest cells, was transplanted into the coelomic cavity of a host chick embryo. Neural crest cells from the chick host migrated to and colonized the grafted hindgut. Thorough characterization of the resulting intestinal chimeras was performed by using immunohistochemistry and vital dye labeling to determine the origin of the host-derived cells, their pattern of migration, and their capacity to differentiate. The formation of the ENS in the intestinal chimeras was found to recapitulate many aspects of normal ENS development. The host-derived cells arose from the vagal neural crest and populated the graft in a rostral-to-caudal wave of migration, with the submucosal plexus being colonized first. These crest-derived cells differentiated into neurons and glial cells, forming ganglionated plexuses grossly indistinguishable from normal ENS. The resulting plexuses were specific to the grafted hindgut, with quail grafts developing two ganglionated plexuses, but mouse grafts developing only a single myenteric plexus. We discuss the advantages of intestinal coelomic transplants for studying ENS development.

Animals↗
PubMed1994

Turning points in labor migration: the case of Hong Kong.

"The Hong Kong experience of emigration and immigration does not fit neatly into models of migration transition. As a city-state with a small rural population, it has exhibited different developmental characteristics from the larger Asian newly industrialized economies. Geopolitical factors have also played a key role in 'patterns' of migration, such as restrictive immigration policies in receiving countries. Also significant are individual considerations of political and economic risk, as evidenced by the current rise in the emigration of skilled and professional workers prior to the return of Hong Kong to China. The author concludes that, rather than a simple turning point in labor migration, there may be multiple turning points in a complex sequence of change."

Asia↗
PubMed1982

[Granulocyte migration in vitro in psoriasis patients induced by aromatic retinoid].

The influence of the aromatic retinoid Ro 10-9359 on the migration of neutrophilic granulocytes was examined in standardized supravital preparation. For this purpose, leukocytes were taken from 5 psoriasis patients who had been treated with 75 mg of aromatic retinoid for 3 weeks. The examinations showed that the course of granulocyte migration was disturbed: the dormant stage was prolonged up to several hours. Maximum cell motility was already reached in that stage of motion in which the granulocytes maintained a constantly changing and bizarre cell pattern. The migration stage, which is characterized by a directed linear cell movement, was absent. Leukocyte survival time was shortened by 50%, and cell degeneration was abnormal under the influence of the aromatic retinoid.

Cell Migration Inhibition↗
PubMed1989

Two earner family migration: a search theoretic approach.

"This paper represents the first attempt to model the two earner family decision to migrate using a joint search theoretic approach. In so doing, the paradox of a couple whose members would both migrate if single but decide not to migrate because they are married to each other is discovered and explained. Furthermore the impact of the rising number of working women and reentry of wives into the labor force on the extent and regional pattern of migration is discussed. Extensions to the model are addressed, as well as future avenues of research, both theoretical and empirical." A geographical focus on the United States is implied.

Americas↗
PubMed1984

Neural crest cell behavior in white and dark larvae of Ambystoma mexicanum: time-lapse cinemicrographic analysis of pigment cell movement in vivo and in culture.

The pattern of migration and motile activity of developing pigment cells of the Mexican axolotl, Ambystoma mexicanum, were analyzed by time-lapse cinemicrography in vivo and in culture. In vivo, melanocytes of dark (D/-) larvae migrate from dorsal to ventral in a highly directional manner. They are elongated and aligned parallel to the direction of migration. Nearly all protrusive activity occurs at their ventral, leading edges. Translocation occurs at a mean rate of 0.7 micron/min and involves alternate or simultaneous advance of the leading and trailing edges of the cell. Indirect evidence suggests that cytoplasmic flow is common. Directional migration occurs in apparent absence of contact between melanocytes. In white (d/d) larvae, protrusive activity is infrequent and the melanocytes move slowly or not at all. Explanted neural crest cells of dark and white larvae attach, spread, and differentiate into melanophores and xanthophores in culture. Individual cultured cells are unbiased in direction of protrusive activity and path of migration. Centrifugal spreading occurs by contacting inhibition of movement. Distribution of protrusive activity, polarity, and contact behavior changes with developmental age in vivo and in culture in ways that may be important in establishing the pigment pattern.

Ambystoma↗
PubMed1994

Neural crest cell formation and migration in the developing embryo.

Neural crest cells arise from the neural tube shortly after its closure and migrate extensively through prescribed regions of the embryos, where they differentiate into most of the peripheral nervous system as well as the facial skeleton and pigment cells. Along the embryonic axis, several distinct neural crest populations differ both in their migratory pathways and range of derivatives. Whereas those cells arising from the midbrain migrate as a uniform sheet of cells, neural crest cells emerging from the hindbrain and trunk regions migrate in a segmented manner. For example, trunk neural crest cells move preferentially through the rostral, but not caudal, half of each somite. Interactions with tissues encountered during migration strongly influence this segmental migratory pattern. For example, the mesodermal somites dictate the segmental migration of trunk neural crest cells and the otic placode appears to attract hindbrain neural crest cells. Although little is known about the molecular basis underlying migration, patterns of gene expression in the hindbrain are thought to contribute to the segmental arrangement of neural crest cells. Furthermore, neural crest cells possess integrin receptors that may be important for interacting with extracellular matrix molecules in their surroundings.

Cell Movement↗
PubMed1998

Differentiation of monocytes into dendritic cells in a model of transendothelial trafficking.

Essential to the dendritic cell system of antigen-presenting cells are the veiled dendritic cells that traverse afferent lymph to enter lymph nodes, where they initiate immune responses. The origin of veiled cells, which were discovered 20 years ago, is unclear. Monocytes cultured with endothelium differentiated into dendritic cells within 2 days, particularly after phagocytosing particles in subendothelial collagen. These nascent dendritic cells migrated across the endothelium in the ablumenal-to-lumenal direction, as would occur during entry into lymphatics. Monocytes that remained in the subendothelial matrix became macrophages. Therefore, monocytes have two potential fates associated with distinct patterns of migration.

Antigens, CD↗
PubMed2006

Temporal identity transition in the avian cerebellar rhombic lip.

The rhombic lip is a discrete strip of neuroepithelium bordering the roofplate of the fourth ventricle, which gives rise to a defined sequence of migratory neuronal derivatives. In rhombomere 1 of the chick, early born cells give rise to post-mitotic hindbrain nuclei, while later derivatives comprise of cerebellar granule cell precursors, a unique proliferative, migratory precursor population that forms the external granule cell layer. We have examined the temporal specification of these two populations using a heterochronic grafting strategy, in ovo. When transplanted into younger neural tube, rhombic lip cells maintain their characteristic molecular markers and migrate into the hindbrain. Granule cell precursor derivatives of late grafts are, in addition, able to exploit neural crest streams to populate the branchial arches. Within the neural tube, derivatives of early and late rhombic lip progenitors display patterns of migration and process extension, characterised by specific trajectories and targets, which are consistent with their temporal origin. However, the normal temporal progression of cell production is disrupted in grafted progenitors: transplanted early rhombic lip fails to subsequently produce granule cell precursors. This indicates that, while the behaviour of derivatives is intrinsically specified at the rhombic lip, the orderly temporal transition in cell type production is dependent on extrinsic cues present only in the later embryo.

Aging↗
PubMed2002

The caudal ganglionic eminence is a source of distinct cortical and subcortical cell populations.

During development, the mammalian ventral telencephalon is comprised of three major proliferative zones: the medial (MGE), lateral (LGE) and caudal (CGE) ganglionic eminences. Through gene expression studies, in vitro migration assays, genetic mutant analysis and in vivo fate mapping in mice, we found that the CGE is a progenitor region that is distinct from both the MGE and LGE. Notably, CGE cells showed a unique in vivo pattern of migration, and the CGE contributed cells to nuclei distinct from those populated by the MGE and LGE. Moreover, we report that the migratory fate of cells from the CGE is intrinsically determined by embryonic day 13.5 (E13.5). Together, these results provide the first insights into the development and fate of the CGE.

Animals↗
PubMed1982

In vitro characterization of response to stimulus (wounding) with regard to ageing in human skin fibroblasts.

Confluent cultured normal human skin fibroblasts from neonatal, adult and aged donors have been stimulated to respond to wounding of the cell sheet. The latent period prior to initial migration of cells from the leading edge of the monolayer is correlated with in vitro population doubling level and in vivo donor age. Time-lapse photography of areas along the edge of the cell sheet reveals a specific pattern of migration by which the cells reestablish a confluent monolayer.

Aging↗
PubMed1998

Heartbroken is a specific downstream mediator of FGF receptor signalling in Drosophila.

Drosophila possesses two FGF receptors which are encoded by the heartless and breathless genes. HEARTLESS is essential for early migration and patterning of the embryonic mesoderm, while BREATHLESS is required for proper branching of the tracheal system. We have identified a new gene, heartbroken, that participates in the signalling pathways of both FGF receptors. Mutations in heartbroken are associated with defects in the migration and later specification of mesodermal and tracheal cells. Genetic interaction and epistasis experiments indicate that heartbroken acts downstream of the two FGF receptors but either upstream of or parallel to RAS1. Furthermore, heartbroken is involved in both the HEARTLESS- and BREATHLESS-dependent activation of MAPK. In contrast, EGF receptor-dependent embryonic functions and MAPK activation are not perturbed in heartbroken mutant embryos. A strong heartbroken allele also suppresses the effects of hyperactivated FGF but not EGF receptors. Thus, heartbroken may contribute to the specificity of developmental responses elicited by FGF receptor signalling.

Animals↗
PubMed1992

Variant choriocarcinoma (BeWo) cells that differ in adhesion and migration on fibronectin display conserved patterns of integrin expression.

Starting from the BeWo choriocarcinoma cell line, two stable variant cell lines (epi and lc) were isolated. Epi cells displayed an epithelioid colony morphology while lc were fibroblastoid. lc cells attached and spread on fibronectin-coated surfaces at significantly lower density of fibronectin than epi or the parent cell line. lc also migrated more efficiently to fibronectin in a trans-filter assay than either epi or parent cells. Integrin expression by the cell lines was investigated by flow cytometry and immunoprecipitation from surface-labelled cells with a panel of subunit-specific antibodies. Integrins alpha 2 beta 1, alpha 5 beta 1, alpha v beta 1 and alpha 6 beta 4 were detected in each case, and levels of expression were identical in the two variant lines. Anti-functional antibodies were used to probe the role of integrins in fibronectin- and vitronectin-mediated adhesion. Complete inhibition of adhesion to fibronectin was observed with anti-beta 1 antibody, and partial inhibition with anti-alpha 5, suggesting that integrin alpha 5 beta 1 is mainly responsible for the interaction. Adhesion to vitronectin was inhibitable using anti-alpha v and anti-beta 1 antibodies, suggesting that integrin alpha v beta 1 is active in these cells as a vitronectin receptor. There was a correlation between the altered morphology of the variant cells and alterations in the distribution of integrin alpha 6 beta 4 and laminin in monolayer cultures. The results support the idea that fibronectin may mediate the migratory behaviour of extravillous trophoblast in vivo. Switch to a more migratory phenotype may be mediated by the selective activation of integrins and altered interaction with basement membrane.

Antibodies, Monoclonal↗
PubMed1999

The chemokine receptor CXCR3 is expressed on malignant B cells and mediates chemotaxis.

B- and T-cell recirculation is crucial for the function of the immune system, with the control of cell migration being mainly mediated by several chemokines and their receptors. In this study, we investigated the expression and function of CXCR3 on normal and malignant B cells from 65 patients with chronic lymphoproliferative disorders (CLDs). Although CXCR3 is lacking on CD5(+) and CD5(-) B cells from healthy subjects, it is expressed on leukemic B lymphocytes from all (31/31) patients with chronic lymphocytic leukemia (CLL). The presence of CXCR3 was heterogeneous in other B-cell disorders, being expressed in 2 of 7 patients with mantle cell lymphoma (MCL), 4 of 12 patients with hairy cell leukemia (HCL), and 11 of 15 patients with other subtypes of non-Hodgkin's lymphomas (NHLs). Chemotaxis assay shows that normal B cells from healthy subjects do not migrate in response to IFN-inducible protein 10 (IP-10) and IFN-gamma-induced monokine (Mig). In contrast, a definite migration in response to IP-10 and Mig has been observed in all malignant B cells from patients with CLL, but not in patients with HCL or MCL (1/7 cases tested). Neoplastic B cells from other NHLs showed a heterogenous pattern. The migration elicited by IP-10 and Mig was inhibited by blocking CXCR3. No effect of IP-10 and Mig chemokines was observed on the cytosolic calcium concentration in malignant B cells. The data reported here demonstrate that CXCR3 is expressed on malignant B cells from CLDs, particularly in patients with CLL, and represents a fully functional receptor involved in chemotaxis of malignant B lymphocytes.

Adult↗
PubMed2002

Elbow and Noc define a family of zinc finger proteins controlling morphogenesis of specific tracheal branches.

The elbow (elB) gene encodes a conserved nuclear protein with a single zinc finger. Expression of ElB is restricted to a specific subset of tracheal cells, namely the dorsal branch and the lateral trunks. Stalled or aberrant migration of these branches is observed in elB mutant embryos. Conversely, ElB misexpression in the trachea gave rise to absence of the visceral branch and an increase in the number of cells forming the dorsal branch. These results imply that the restricted expression of ElB contributes to the specification of distinct branch fates, as reflected in their stereotypic pattern of migration. As elB loss-of-function tracheal phenotypes are reminiscent of defects in Dpp signaling, the relationship between ElB and the Dpp pathway was examined. By using pMad antibodies that detect the activation pattern of the Dpp pathway, we show that Dpp signaling in the trachea is not impaired in elB mutants. In addition, expression of the Dpp target gene kni was unaltered. The opposite is true as well, because expression of elB is independent of Dpp signaling. ElB thus defines a parallel input, which determines the identity of the lateral trunk and dorsal branch cells. No ocelli (Noc) is the Drosophila protein most similar to ElB. Mutations in noc give rise to a similar tracheal phenotype. Noc is capable of associating with ElB, suggesting that they can function as a heterodimer. ElB also associates with the Groucho protein, indicating that the complex has the capacity to repress transcription of target genes. Indeed, in elB or noc mutants, expanded expression of tracheal branch-specific genes was observed.

Amino Acid Sequence↗