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PubMedDate not supplied

[Lymphocyte migration in internally irradiated animals. Effect of internal beta radiation on the migration of spleen lymphocytes in CBA mice].

The syngeneic transfer system was used to study migration of 51Cr-labelled spleen lymphocytes in mice after incorporation of beta-emitter, 35S-methionine. Migration of 51Cr-labelled lymphocytes to lymph nodes was stably decreased, and to liver, kidneys and lungs increased. The lymphocyte migration impairment was associated with the influence of beta-radiation on both the migratory properties of cells and the factors of their microenvironment responsible for the lymphocyte migration within the mouse body. No distinctions were observed in the character and manifestation of disturbances of the lymphocyte migration after the injection of 35S-methionine and gamma-emitter, 75Se-selenomethionine.

Animals↗

PubMed1980

Leukocyte migration in different systems. Effect of colchicin. Kinetics of migration under agarose.

In a double-filter modification of Boyden's method, formylmethionylleucylphenylalanine (FMLP) needed the presence of fresh plasma to induce leukocyte locomotor kinetics which compared with a model for directional migration. FMLP, or zymosan-activated plasma, did not stimulate migration in capillary tubes. The kinetics of leukocyte migration under agarose towards zymosan-activated plasma were more compatible to a model for increased random motility than for directional migration. Treatment of leukocytes with colchicin reduced their migration under gradient and non-gradient conditions in millipore filters, capillary tubes, and in under-agarose experiments.

Blood↗

PubMed1993

Studies of lymphocyte transendothelial migration: analysis of migrated cell phenotypes with regard to CD31 (PECAM-1), CD45RA and CD45RO.

CD31 is a 130,000 MW cell-surface glycoprotein expressed on endothelial cells, polymorphonuclear leucocytes, monocytes and about 50% of peripheral blood lymphocytes, and it has been proposed that it plays a role in transendothelial migration. If it is involved in endothelial transmigration of lymphocytes then the proportion of CD31+ cells should be increased in the lymphocyte population which has crossed an endothelial monolayer. This was tested using two endothelial types, namely human umbilical vein endothelial cells (HUVEC) and rat high endothelial venule (RHEV) cells. As a control, lymphocyte CD45RA and CD45RO expression was also determined since there is a correlation between lymphocytes bearing these isoforms and different migratory patterns. Double labelling techniques showed a close correlation between CD31 and CD45RA expression. With HUVEC monolayers, the transmigrated lymphocyte population was depleted of CD31+ cells. This depletion was even more marked if the HUVEC monolayers had been stimulated with interleukin-1 beta (IL-1 beta). The migrated lymphocytes were enriched for CD31-CD45RO+ cells but depleted of CD31+CD45RA+ cells. In addition, lymphocyte populations depleted of CD31+ cells by immunopanning were also able to migrate across HUVEC monolayers. Taken together these data suggest that lymphocyte CD31 expression is not necessary for transmigration across HUVEC monolayers and, if anything, is negatively correlated with transmigration. With the second endothelial cell type, RHEV cells, there was no consistent change in the proportion of CD31+ lymphocyte in the transmigrated population, suggesting neither a positive nor a negative correlation between CD31+ expression and lymphocyte transmigration across RHEV cells. However, with both endothelial cell types, the migrated lymphocyte populations were enriched for the marker CD45RO. In conclusion, lymphocyte surface expression of CD31 is not necessary for transmigration across the endothelial cell types used in this study, but with both cell types an enrichment of CD45RO+ lymphocytes is seen in the migrated population.

Antigens, Differentiation, Myelomonocytic↗

PubMed1996

Lyphocyte migration in L-selectin-deficient mice. Altered subset migration and aging of the immune system.

Lymphocyte trafficking across high endothelial venules (HEV) of peripheral lymph nodes (PLN) is dependent upon lymphocyte expression of L-selectin. Mice that lack this adhesion molecule provide an opportunity to determine the long-term role of L-selectin-mediated migration in the maintenance of leukocyte subpopulations. HEV in L-selectin-deficient mice were phenotypically, morphologically, and functionally comparable with wild-type mice, although there was a 70 to 90% reduction in the number of lymphocytes within PLN. These lymphocytes most likely entered PLN through the afferent lymphatics, since they did not migrate into PLN of normal mice during short-term homing experiments. The impaired trafficking of lymphocytes across PLN-HEV resulted in the accumulation of memory (CD18highCD44high) lymphocytes within PLN, and also altered the distribution of lymphocyte subpopulations within other tissues. Specifically, a 30 to 55% increase in splenic cellularity occurred due to increases in both naive and memory lymphocytes. Circulating lymphocyte numbers or subpopulations were not altered in young L-selectin-deficient mice, but circulating monocyte numbers were increased nearly threefold. In contrast, older L-selectin-deficient mice had disproportionate increases of both naive and memory CD4+ T cells present within spleen and blood. These results and the finding that memory lymphocytes in wild-type mice expressed L-selectin demonstrate a requirement for L-selectin in the regulation of memory lymphocyte migration. Therefore, L-selectin-dependent pathways of lymphocyte migration are important for the normal migration of both naive and memory lymphocytes.

Animals↗

PubMed1993

Cash seeking behaviour and migration: a place-to-place migration function for Cote d'Ivoire.

"This paper presents estimates of an aggregate place-to-place migration function for Cote d'Ivoire based on the premise that migration is motivated by rural residents' desire for cash income. The results indicate that migration from a region responds differently to changes in cash and food income, which supports the idea that it is the composition of rural income, and not just its level, that determines migration flows."

Africa↗

PubMed1993

Migration and the metropolis: recent research on the causes of migration to southeast England.

"The paper focuses on one main issue: the relative importance of housing and labour market forces in explaining the volume and nature of migration to the southeast region [of England]." The author reviews recent literature in an attempt to determine "why people migrated to [and from] the southeast...[and] what the consequences of these in-migration and out-migration streams were for their respective origin and destination regions."

Behavior↗

PubMedDate not supplied

[Interregional migration and net migration: comments on the Italian case].

"After having examined the relations between the partial net migration and the corresponding total net migration, an attempt is made to identify some indicators...of inter-regional mobility, considering the size of the total net migration in relation to all the net migrations with other territorial units. Attention is particularly focused on two indicators: the index of net regional migratory interchange, and the index of net total migratory interchange...." Data are for regions in Italy during the period 1955-1989. (SUMMARY IN ENG AND FRE)

Demography↗

PubMed1993

Mechanistic differences between migration inhibitory factor (MIF) and IFN-gamma for macrophage activation. MIF and IFN-gamma synergize with lipid A to mediate migration inhibition but only IFN-gamma induces production of TNF-alpha and nitric oxide.

Previously we found that murine macrophage migration inhibition (MMI) was mediated by IFN-gamma-priming and lipid A triggering. With the recent availability of human recombinant migration inhibitory factor (MIF), which is distinctly different from IFN-gamma and other cytokines, we have now attempted to explore possible mechanistic differences between IFN-gamma and MIF to mediate MMI. Neither MIF not IFN-gamma were active alone, but effectively primed murine inflammatory macrophages for subsequent triggering by lipid A to mediate MMI. A specific neutralizing antibody for rMIF abrogated MMI mediated only by MIF and not by IFN-gamma-primed macrophages. Distinct differences were also found between the mechanisms by which MIF and IFN-gamma synergized with lipid A for activation in that IFN-gamma-primed and lipid A triggered macrophages produced TNF and nitric oxide (NO), whereas MIF-primed cells did not. Macrophages primed with IFN-gamma and triggered by rTNF were inhibited in their migration, whereas MIF failed to synergize with rTNF for MMI. An inhibitor of NO production NG-monomethyl-L-arginine inhibited MMI mediated by higher activating concentrations of lipid A and by IFN-gamma-primed and lipid A triggered macrophages, but had no effect on MIF-primed cells in concert with lipid A for increased expression of both TNF-alpha mRNA and NO synthase mRNA. Taken together, our results indicate that both MIF and IFN-gamma prime macrophages to synergize with lipid A to mediate MMI but by different mechanisms. The activation process by IFN-gamma to mediate migration inhibition appears to resemble requirements for rendering macrophages tumor cytotoxic in the production of TNF for autocrine-mediated NO generation by primed macrophages. In contrast, MIF-mediated MMI was independent of requirements for either TNF or NO production.

Amino Acid Oxidoreductases↗

PubMed1985

Is there a step-wise migration in Nigeria? A case study of the migrational histories of migrants in Lagos.

"The paper sets out to test whether or not the movement pattern of people in Nigeria is step-wise. It examines the spatial order in the country and the movement pattern of people. It then analyzes the survey data and tests for the validity of step-wise migration in the country. The findings show that step-wise migration cannot adequately describe all the patterns observed." The presence of large-scale circulatory migration between rural and urban areas is noted. Ways to decrease the pressure on Lagos by developing intermediate urban areas are considered.

Africa↗

PubMed1982

Hierarchically organized migration fields: the application of higher order factor analysis to population migration tables.

"The structure of human geographical systems is often of a hierarchical nature. Population migration systems can usefully be conceptualized as a series of hierarchically related levels of migration fields: the fields at one level nesting within the fields at the next higher level. Such migration fields and the relationships between different levels can be extracted from large population migration origin-destination matrices with the aid of higher order factor analysis." A case study of the western United States illustrating the application of higher order factor analysis to large interaction matrices is presented.

Americas↗

PubMed1998

Hierarchical households and gendered migration in Latin America: feminist extensions to migration research.

In this review essay, the author argues that migration theory can be advanced by analyzing gender differences in migration processes. The author brings together feminist empirical work from diverse settings within Latin America in order to illustrate and discuss theoretical extensions to migration research. In particular, the discussion focuses on the centrality of intra-household power relations and dynamics for understanding who migrates, and with what consequences. The author further argues that these theoretical understandings emerge from the culturally and historically specific operation of processes in particular places within Latin America.

Culture↗

PubMed2004

[Increased cell migration of nasopharyngeal carcinoma cell lines in vitro by macrophage migration inhibitory factor].

OBJECTIVE: To study whether macrophage migration inhibitory factor (MIF) can increase the ability of invasion of nasopharyngeal carcinoma cell lines in vitro, and to investigate the mechanism of invasion and metastasis of tumor cells during the early stage of nasopharyngeal carcinoma (NPC). METHODS: The invasion and migration of NPC cell lines, CNE-1 and CNE-2, were evaluated by micron-migration assay in a chamber with 8- micro m porosity polycarbonate filter membrane. Flow cytometry and western blotting were adopted respectively to evaluate the protein expression level of matrix metalloproteinase 2 and 9 (MMP2, MMP9) in MIF treated or non-treated tumor cell lines. The concentrations of interleukin 8 (IL-8) secreted into the culture supernatant by the cells were measured by using Enzyme-linked immunoabsorbent assay (ELISA). RESULTS: (1) After treatment with MIF for 24 hours, the number of cells passing through the 8- micro m filter membrane were increased in CNE-1 (113.7 +/- 20.9) and CNE-2 (311.3 +/- 48.9), as compared with that of non-MIF treated NPC cells. A significant statistic difference (P = 0.005, P = 0.001) was obtained in both CNE-1 and CNE-2 cells. (2) After treatment with MIF, the number of MMP9-positive cells increased in both CNE-1 (from 28.5% +/- 2.45% to 82.4% +/- 3.49%, P = 0.001) and CNE-2 (from 32.8% +/- 3.48% to 86.1% +/- 1.62%, P = 0.002) cell lines. In addition, an enhanced MMP9 protein expression up to 3-fold was observed in both cell lines. However, the expression level of MMP2 did not changed significantly between treated and non-treated cell lines (P > 0.05). (3) The concentration of IL-8 in the culture supernatant of CNE-2 was 1201.8 +/- 593.3 pg/ml after treatment with MIF for 24 h, remarkably higher than that without MIF treatment (32.7 +/- 20.1 pg/ml, P = 0.026). A similar change was not detected in CNE-1 (P = 0.581) cells. CONCLUSIONS: (1) MIF can increase cell migration of CNE-1 and CNE-2 NPC cell lines in vitro. (2) A higher expression level of MMP9 and an up-regulated IL-8 by MIF may play a very important role in the progress of NPC, such as invasion and metastasis.

Cell Line, Tumor↗

PubMed1978

Migration enhancement by tuftsin of human mononuclear cells and its effect on the migration inhibition factor test with tumor antigens.

Tuftsin, a physiological tetrapeptide which stimulates the phagocytic activity of polymorphonuclear neutrophils and macrophages, is found to enhance the migration of normal and sensitized human mononuclear cells. Furthermore, it abrogates the migration inhibition effect of human malignant melanoma antigen. This finding may represent a possible explanation for the unexpected migration enhancement often observed when the migration inhibition test is employed.

Antigens, Neoplasm↗

PubMed1980

[Leukocyte migration inhibition test in multiple sclerosis - results of a migration technic according to Clausen using brain specific antigens].

The leukocyte migration inhibitory factor (LIF) was examined in 57 test persons--27 patients with multiple sclerosis (MS) and 30 normals--with the indirect and the direct leucocyte migration inhibition test in agarose (LMIAT). The stimulation of lymphocytes was carried out by the application of myelin basic protein (BP) and a membrane-associated antigen of normal brain (NTA). The mean value of controls +/- 2 s and the migration index less than or equal to 0,80 were used for limiting. In the indirect technique could be established significant group effects (NTA- and BP-values of MS cases compared to the controls) after 10 hours of incubation. The direct method showed in MS patients a significant lowered migration-index on an average after stimulation with the NTA; controls gave negative findings (except two cases). The valence of the test system and prospective modifications for further results were indicated.

Adult↗

PubMed1997

Migration as family strategy: rural-urban labor migration in India during the twentieth century.

"The article analyzes the role of families in processes of rural-urban migration in India in the twentieth century. It shows that the continuous circular form of this migration should be explained as a consequence of rural family strategies. Already established kinship relations or marriage opportunities in the future act as a centripetal force, drawing the labor migrants back to their communities time and again. In addition, the article shows how labor migration is informed by economic and cultural considerations which determine the socioeconomic behavior of men and women."

Asia↗

PubMed1996

A continent of migration: European mass migration in the twentieth century.

"This article gives an overview of the size and geography of migration to and within Europe. Changing causes, patterns and trends of international migration, as well as key periods, are discussed. It also analyses the composition of foreign resident populations in Europe. The article covers the second half of the twentieth century. Different types of mass migration as well as links between particular sending and receiving countries are analysed. The article also looks at public opinion concerning ethnocentric attitudes and the number of foreigners in Europe. Finally, policy options are discussed."

Attitude↗

PubMed1984

Influence of colchicine and vinblastine on the intracellular migration of secretory and membrane glycoproteins: III. Inhibition of intracellular migration of membrane glycoproteins in rat intestinal columnar cells and hepatocytes as visualized by light and electron-microscope radioautography after 3H-fucose injection.

In the first paper of this series (Bennett et al., 1984), light-microscope radioautographic studies showed that colchicine or vinblastine inhibited intracellular migration of glycoproteins out of the Golgi region in a variety of cell types. In the present work, the effects of these drugs on migration of membrane glycoproteins have been examined at the ultrastructural level in duodenal villous columnar cells and hepatocytes. Young (40 gm) rats were given a single intravenous injection of colchicine (4.0 mg) or vinblastine (2.0 mg). At 10 min after colchicine and 30 min after vinblastine administration, the rats were injected with 3H-fucose. Control rats received 3H-fucose only. All rats were sacrificed 90 min after 3H-fucose injection and their tissues processed for radioautography. In duodenal villous columnar cells, 3H-fucose labeling of the apical plasma membrane was reduced by 51% after colchicine and by 67% after vinblastine treatment; but there was little change in labeling of the lateral plasma membrane. Labeling of the Golgi apparatus increased. This suggests that labeled glycoproteins destined for the apical plasma membrane were inhibited from leaving the Golgi region, while migration to the lateral plasma membrane was not impaired. In hepatocytes, labeling of the sinusoidal plasma membrane was reduced by 83% after colchicine and by 85% after vinblastine treatment. Labeling of the lateral plasma membrane also decreased, although not so dramatically. Labeling of the Golgi apparatus and neighboring secretory vesicles increased. This indicates that the drugs inhibited migration of membrane glycoproteins from the Golgi region to the various portions of the plasma membrane. Accumulation of secretory vesicles at the sinusoidal front suggests that exocytosis may also have been partially inhibited. In both cell types, microtubules almost completely disappeared after drug treatment. Microtubules may, therefore, be necessary for intracellular transport of membrane glycoproteins, although the possibility of a direct action of these drugs on Golgi or plasma membranes must also be considered.

Animals↗

PubMed1983

Migration of human leukocytes from soft agarose droplet: a simplified method for studying chemotaxis and spontaneous migration.

Studies of in vitro chemotaxis and spontaneous migration of human leukocytes using the accepted method with the Boyden-chamber-filter are troublesome, because of the need for specially constructed vessels as well as the difficulties caused by the use of membrane filters. We describe a new and simplified method for measuring human leucocyte chemotaxis, which is a modification of the recently described underagarose migration method and which is based upon spontaneous migration of cells from a soft agarose droplet and in response to a chemotactic gradient. We examined suspensions of leukocytes, purified granulocytes, and mononuclear cells from 10 healthy normal adults and from 10 samples of cord blood using E Coli O111B4 endotoxin-activated human serum as attractant. Our results showed that the mean chemotactic indices (C.I.-chemotaxis/migration) for purified granulocytes and for mononuclear cells from normal individuals were 3.0 +/- 1.2 and 2.7 +/- 1.5, respectively. Chemotaxis was significantly reduced when unwashed leukocytes were studied, indicating a detrimental effect of autologous plasma on leukocytic response to a chemotactic stimulus in this system. Cord blood cells showed normal spontaneous migration, but significantly decreased chemotaxis. This preliminary report shows that the technique is simple, rapid, and reproducible, and can detect abnormalities of chemotaxis in both granulocytes and mononuclear cells.

Adult↗