Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Return Migration”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 379 records · Page 21Linked to original sources
PubMed1994

Social environment and mental health in returning migrant children.

One typical feature of population in Europe is migration, often accompanied with poor integration into the surrounding society. Their significance as risk factors for children's mental health was studied among the 320 school-aged children who returned from Sweden to Finland during the years 1984-85. Every one of the returnees was assigned a non-migrant control from the same class in the same school, matched by age and sex. The data was gathered by questionnaires to parents, children and teachers, concerning family environment, the children's mental health and school achievements (1). The returning migrant boys more often had psychiatric disorders in their teachers' estimations (2) than did the controls and they also scored higher in the self-report scale 'Children's Depression Inventory' (3), but no such difference was found among the girls. The families' poor integration into the society, as measured by the parent's unemployment history, present work situation, membership activities or hobbies and reading of daily newspapers was found to reflect on the child's mental well-being, especially increasing antisocial features in the boys' behaviour. Preventive mental health care in multisectorial cooperation is recommended.

Child↗
PubMed1988

A study of lymphocyte kinetics in nasopharyngeal carcinoma with indium III oxine-labelled lymphocytes.

The kinetics of lymphocyte migration in 12 pre-treatment patients with nasopharyngeal carcinoma (NPC) and three cancer controls in remission were studied with Indium III oxine-labelled autologous lymphocytes. The migratory patterns of the labelled lymphocytes were defined by serial gamma imaging and blood clearance of Indium over 72 h. Once in the systemic circulation the labelled lymphocytes migrated immediately to the liver and spleen. In all the subjects studied the lymphocytes began to migrate out of the liver at 0.5 h, only to return to the organ gradually between 2 and 72 h. In the control subjects the lymphocytes migrated out of the spleen from about 4 h. This coincided with a hump in the peripheral blood clearance curve after about 4 h signifying re-entry of the lymphocytes into the vascular space from the spleen. In the 'early' NPC subjects (Stage I-III) the rate at which the lymphocytes entered the spleen was much reduced from about 4 to 72 h, suggesting a prolonged transit time of the lymphocyte through the organ. However, there were still prominent humps in the blood clearance curves, suggesting significant re-entry of lymphocytes into the vascular space. In the 'late' NPC subjects (Stage IV-V), the activity of the spleen was low between 4 and 72 h and there was continuous sequestration of lymphocytes in the organ. Consequently the humps in the blood clearance curves were much reduced or absent. The activities of the metastatic lymph nodes were intense between 2 and 48 h, suggesting marked sequestration of lymphocytes in the diseased lymph nodes. Migration of lymphocytes in the metastatic area of the liver was notably absent and presented as cold areas on gamma scanning. The sequestration of lymphocytes in the spleen and metastatic lymph nodes in 'early' and 'late' NPC could lead to a contraction of intravascular lymphocyte pool and could explain the stage-dependent lymphopenia reported in NPC.

Adult↗
PubMed1996

[Understanding migratory phenomena: mobility within a village in Hérault from 1836 to 1962].

Using a previous reconstitution of families living in the village of Puéchabon (Hérault) and twenty-three lists of its inhabitants from 1836 to 1962 as a base, the author has analyzed the migrations of the villagers according to sex, marital status and age group while distinguishing two types of migration: actual departures and entries (permanent or long-term departures, and entries by newcomers or those returning after prolonged absences), and short-term absences and subsequent returns. Using this typology, he brings out three periods of migration for the village residents: before the War of 1870, there were traditional movements; between 1870 and World War II, a pronounced rural exodus occurred; and since then, there has been a less striking but more regular decline in population.

Emigration and Immigration↗
PubMed1977

The mechanism of cobalamin-dependent rearrangements.

Adenosylcobalamin-dependent rearrangements are enzyme catalyzed reactions in which a hydrogen atom is transfered from one carbon atom to an adjacent one in exchange for a group X which migrates in the opposite direction. In the hydrogen transfer step, the mechanism of which is reasonably well understood, the cofactor serves as an intermediate hydrogen carrier. The transfer of hydrogen to the cofactor involves homolysis of the carbon-cobalt bond to generate cob(II) alamin and the 5'-deoxyadenos-5'-yl radical, followed by abstraction of a hydrogen atom from the substrate to form 5'-deoxyadenosine and the substrate radical. After migration of group X, the hydrogen atom is returned to the product radical by the reverse of the above reactions to generate the final product and reconstitute the cofactor. In contrast to the transfer of hydrogen, the mechanism of group X migration is poorly understood. Many reactions mechanisms have been proposed on chemical grounds, but there is insufficient biochemical evidence to permit a choice among these propsals. A quantity of negative evidence has accumulated suggesting that group X migration does not involve alkylation of the cobalt of cobalamin by the substrate, but in the absence of firm data supporting an alternative mechanism, even this weak conclusion must be regarded as provisional.

Chemical Phenomena↗
PubMed1988

Highly-skilled international migrants, careers and internal labour markets.

"This paper is addressed to the interplay of careers and internal labour markets (ILMs) in explaining the international migration of professional and technical personnel, particularly within transnational corporations (TNCs). It begins by reviewing the current state of the theoretical art, focusing on five main elements: the international spatial division of labour; the concept of career; the organization of ILMs; the lubrication of the migration system by recruitment, placement and relocation agencies; and reintegration of returning expatriates. There follows a discussion of selected aspects of the volume and characteristics of ILM migrations among the highly-skilled, using government, employer organization's and individual company data."

Demography↗
PubMed2006

[Helminth migration in the host].

Helminths belong to important human pathogens in tropical and subtropical countries. They have simple one-host life cycles or they use several hosts for their development. There are two main entry points for human helminths: the skin and the oral cavity. Skin penetration is followed by tissue migration of helminth stages towards target organs. Also some perorally acquired helminths migrate throughout the human body and then (a) they return to and mature in the intestine or (b) they search for specific final location in other (extraintestinal) tissues/organs. Particular developmental stages having different migration routes, and different roles of human beings as final, intermediate and paratenic hosts are briefly mentioned.

Animals↗
PubMed1982

Bronchial mucosal permeability and its relationship to airways hyperreactivity.

The airways epithelium is made up of eight different cells with the ciliated cell, the microvillar or brush cell, and the goblet cells being the predominant cells forming the surface. These cells are joined by epithelial tight junctions and covered by a layer of mucus. The epithelium also contains an abundance of nerve fibres which are more concentrated in the extrathoracic airways. These irritant receptors or rapidly adapting stretch receptors run circumferentially around the surface cells and respond to a wide variety of stimuli including gases, smoke, dust, aerosols and antigens. While mast cells can be found in the airways lumen and in the epithelium, the greatest number are located in the submucosa. The epithelial surface barrier is normally quite impermeable to material that lands on it. However, a wide variety of injuries can induce inflammatory reactions and change the mucosal permeability to allow more easy access to the irritant receptors in the epithelia and mast cells in the submucosa. Injury by cigarette smoke induces an inflammatory reaction which causes an increase in mucosal permeability which returns to control values within a six-hour period. Maximal mucosal permeability is associated with the exudative phase of the inflammatory reaction where there is an increase in airways edema. By the time the polymorphonuclear leukocytes migrate to the mucosal surface, the permeability has returned to normal. These minimal inflammatory injuries are also associated with an increased cell turnover which may be responsible for the thickening of the basement membrane in chronic inflammatory states such as asthma.

Animals↗
PubMed1985

Granulocyte migration in ulcerative colitis.

Although histologically relapses in ulcerative colitis are characterized by an intense granulocyte infiltrate, there is evidence both from in vitro function tests and skin window migration studies in vivo that there is defective granulocyte function in ulcerative colitis. We have recently developed a method for non invasively monitoring granulocyte migration to sites of inflammation using indium-111-labelled granulocytes, and have used this technique in fifteen patients with ulcerative colitis. In all fifteen cases there was rapid migration of indium-111-labelled granulocytes to inflamed bowel within 10 min of return of the labelled cells. This study provides no support for a significant granulocyte migration defect in ulcerative colitis.

Adolescent↗
PubMed1998

Accounting for two population turnarounds in nonmetropolitan America.

"The turnaround [in U.S. rural-to-urban migration] of the 1970s, the metropolitan resurgence of the 1980s, and the rural rebound of the 1990s [have been] described as three unanticipated changes in migration.... [This chapter] compares the magnitude of the three changes in net migration and contrasts the two nonmetropolitan turnarounds.... The results support a view of the 1970s turnaround as the outcome of long-term deconcentrating trends that were interrupted from the late 1970s to the late 1980s by circumstances that favored metropolitan areas. The return of nonmetropolitan territory to net in-migration in the 1990s appears to be due in part to favorable economic conditions that allow more people to act on preferences for smaller places."

Americas↗
PubMed1975

Effects on cancer patients of leukapheresis with the continuous-flow blood cell separator. II. Immunologic parameters in vitro.

The immunologic effects of leukapheresis on cancer patients and three other groups of donors using the continuous-flow blood cell separator are presented according to the protocol described in the preceding article. Transient declines were noted in per cent T-lymphocytes of some, but not all, leukapheresed normal donors and cancer patients. These declines were comparable to the small declines observed in sham donors and the fluctuations in per cent T-lymphocytes noted in individuals who did not undergo leukapheresis. There were no changes in lymphocyte-mediated cytotoxicity to a melanoma cell line in 2 of 4 melanoma patients, while values in 2 patients fell by about one-half within 4 hours and returned to preleukapheresis levels by 24 hours. Release of macrophage migration inhibition factor by lymphocytes from all 4 cancer patients and 4 normal donors, in whom this parameter was studied, fell transiently and returned to preleukaphresis levels within 24 hours. Blastogenic responses of lymphocytes from cancer patients and normal donors to phytohemagglutinin (PHA) and in one way mixed lymphocyte reactions increased in several individuals and decreased slightly in others. There appears to be no significant immunosuppressive effects (within the parameters studied) of a single leukapheresis for lymphocytes on the blood cell separator, since changes in lymphocyte parameters were relatively minor, transient, and variable and, where studied, paralleled fluctuations observed in sham donors and individuals not undergoing leukapheresis.

Antibody Formation↗
PubMed1998

Induction of Ets-1 in endothelial cells during reendothelialization after denuding injury.

Ets-1, a transcription factor, is induced in endothelial cells (ECs) during angiogenesis. Here, we investigated the expression of Ets-1 during reendothelialization. When a confluent monolayer of human umbilical vein endothelial cell line, ECV304, was denuded, ECV304 at the wound edge expressed Ets-1. An immunohistochemical analysis revealed that Ets-1 accumulated in migrating cells at the wound edge and returned to basal level when reendothelialization was accomplished. This induction of Ets-1 could be reproduced in in vivo denudation of rat aortic endothelium by a balloon catheter. The induction of Ets-1 in ECs after denudation was regulated transcriptionally, and humeral factors released from injured ECs might not be responsible. Mitogen-activated protein kinase (MAPK) activities were investigated to explore the mechanism of this induction. Although extracellular signal-regulated protein kinase 1/2 (ERK1/2), c-Jun N-terminal kinase 1 (JNK1), and p38 were activated after denudation, the activation of ERK1 and p38 was more rapid and prominent. PD98059, a specific MAPK/ERK kinase (MEK) 1 inhibitor, did not affect the induction of ets-1 mRNA, whereas SB203580, a specific p38 inhibitor, almost completely abrogated its induction. These results indicate that Ets-1 is induced in ECs after denudation through activation of p38. This induction of Ets-1 may be relevant for reendothelialization by regulating the expression of certain genes.

Animals↗
PubMed2001

Neuronal and non-neuronal responses to nerve crush in a pulmonate snail, Melampus bidentatus.

Immunohistochemical and ultrastructural techniques were used to study sequelae of nerve injury in the pulmonate snail Melampus bidentatus. Either pedal or tentacle nerves were crushed, severing all axons, and recovery was monitored over 15 days. The axons regenerated from the segment attached to the soma, with no evidence of fusion of proximal and distal segments. The medium to large axons of central neurons, including those monitored with serotonin immunohistochemistry, grow distally across the path of smaller axons extending centrally from peripheral somata. The regions into which the growing axons projected were a focus of phagocytic activity. Cells previously labeled by PKH-26PCL, a fluorescent marker for phagocytic activity, were attracted to the crushed nerve within 6 h and were a consistent feature in the vicinity of the injury for at least 9 days, gradually extending their range as repair progressed in both directions from the crush. Repair proceeded within an intact sheath, and many sheath cells survived the crush, although the nuclear dye Hoechst 33258 revealed an initial distortion of their nuclei. The concentration of cells in the sheath in the crushed region increases after the crush, with the packing of nuclei peaking at 3 days and gradually returning to control conditions; this probably reflects migration of resident sheath cells. Cell division is rare in the sheath of intact nerves, but labeling with bromodeoxyuridine increases at the crush site between 4 and 9 days, indicating that cell replacement also occurs at the site.

Animals↗
PubMed1982

Elemental analysis of freeze-dried thin sections of Samanea motor organs: barriers to ion diffusion through the apoplast.

Leaflet movements in the legume Samanea saman are dependent upon massive redistribution of potassium (K), chloride (Cl), and other solutes between opposing (extensor and flexor) halves of the motor organ (pulvinus). Solutes are known to diffuse through the apoplast during redistribution. To test the possibility that solute diffusion might be restricted by apoplastic barriers, we analyzed elements in the apoplast in freeze-dried cryosections of pulvini using scanning electron microscopy/x-ray microanalysis. Large discontinuities in apoplastic K and Cl at the extensor-flexor interface provide evidence for a barrier to solute diffusion. The barrier extends from the epidermis on upper and lower sides of the pulvinus to cambial cells in the central vascular core. It is completed by hydrophobic regions between phloem and cambium, and between xylem rays and surrounding vascular tissue, as deduced by discontinuities in apoplastic solutes and by staining of fresh sections with lipid-soluble Sudan dyes. Thus, symplastic pathways are necessary for ion redistribution in the Samanea pulvinus during leaflet movement. In pulvini from leaflets in the closed state, all cells on the flexor side of the barrier have high internal as well as external K and Cl, whereas cells on the extensor side have barely detectable internal or external K or Cl. Approximately 60% of these ions are known to migrate to the extensor during opening; all return to the flexor during subsequent closure. We propose that solutes lost from shrinking cells in the outer cortex diffuse through the apoplast to plasmodesmata-rich cells of the inner cortex, collenchyma, and phloem; and that solutes cross the barrier by moving through plasmodesmata.

Cell Wall↗
PubMed1971

Migrations and growth of deep-sea lobsters, Homarus americanus.

In distinct contrast to the restricted movements of coastal stocks of lobsters (Homarus americanus), those inhabiting the outer continental shelf undertake extensive seasonal migrations. Of 5710 tagged lobsters released on the outer continental shelf off New England from April 1968 to June 1969, 400 had been recaptured by April 1970. The distribution of the recoveries demonstrated shoalward migration in spring and summer and a return to the edge of the shelf in fall and winter. Deep-sea lobsters have a faster rate of growth than coastal lobsters; growth increments at molting and the frequency of molting are greater.

Animals↗
PubMed1981

Prolonged reduction in polymorphonuclear adhesion following oral colchicine.

Polymorphonuclear leucocyte (PMN) function was studied in 7 healthy subjects before and after 5 mg of colchicine taken in divided doses over 24 hours. Mean adherence to nylon fibre colums fell from a pretreatment level of 51% to 33.6% by day 1, remained low (31.8%) at day 5, and returned to pretreatment levels only by about day 9. Random motility (agarose plate method) fell from 932 micrometers to 688 micrometers by day 1, but had returned to normal by day 5. Directed migration and the phagocytic index (opsonised Candida albicans method) were not affected by colchicine treatment. In this marked and prolonged reduction in PMN adhesion implies an influence on maturing PMN precursors in bone marrow. Adherence to nylon fibres may reflect in-vivo properties of PMN which are important in the pathogenesis of acute gouty arthritis.

Administration, Oral↗
PubMed1992

Radiology-assisted placement of implantable subcutaneous infusion ports for long-term venous access.

Implantable infusion port devices are generally placed surgically. A technique for radiology-guided placement in adults is described, and the experience with 103 attempted port placements between June 1989 and October 1991 is analyzed. Placements were successful in 102 attempts (99%). Minor procedural difficulties occurred in six patients (5.9%). One major procedural complication (large hematoma) precluded port placement. Two patients were lost to follow-up after uncomplicated placements. There were four (4.0% of 100 patients) minor late complications. Major late complications requiring port removal occurred in 13 (13.0%): five suspected catheter-related infections, four catheter-related venous thromboses refractory to thrombolysis, and one each of wound dehiscence, formation of hematoma near the port, extraluminal migration of the catheter, and poor blood return. With a cumulative follow-up of 15,880 days (43.5 patient-years) available, a rate of major complications of 13.6%, or 0.86% per 1,000 access days, is comparable to the rates of large surgical series. Radiology-guided placement of infusion ports is safe and may offer advantages over surgical implantation.

Adolescent↗
PubMed1990

Impact of refeeding on intestinal development and function in infant rabbits subjected to protein-energy malnutrition.

The impact of early postnatal protein-energy malnutrition and of 4, 7, and 14 d of nutritional rehabilitation on small intestinal growth, development, structure and function was examined in 28-, 32-, 35-, and 42-d-old infant rabbits. Malnutrition was induced by litter expansion 7 d postpartum and, in randomly selected malnourished animals, refeeding was begun at weaning, 28 d. Results are compared to ad libitum fed dietary controls. Malnutrition altered the small intestine of the developing rabbit, as evidenced by: 1) reduced jejunal and ileal mass as shown by decreased mucosal wt, protein, and DNA content; 2) depressed epithelial proliferation and enterocyte migration along the crypt-villus axis; 3) delayed epithelial maturation as measured by mucosal enzyme activities; and 4) enhanced glucose-stimulated Na+ transport. Refeeding stimulated rapid and complete recovery, as evidenced by: 1) restoration of jejunal and ileal mucosal mass within 4 d; 2) enhancement of epithelial renewal and enterocyte migration by 7 d; and 3) complete return of the normal pattern of mucosal enzymes by 14 d. With 7 d of refeeding, glucose-stimulated Na+ transport was down-regulated to the level of dietary controls. We conclude that early postnatal protein-energy malnutrition has a severe impact on small intestinal growth, development, structure, and function. Furthermore, a brief period refeeding induced a rapid and complete recovery of these parameters.

Animals↗
PubMed1982

[Kinetics of hematopoietic stem cell migration in mice after severe mechanical injury].

Experiments on mice have shown that severe mechanical trauma brings about phasic changes in the kinetics of hemopoietic stem cell migration. Within the first four days after the trauma the migration of stem cells gets intensified and returns to normal by day 8. This reaction is regarded to be a defence one, since it guarantees the function of the most important component of immunity, namely the organs where stem cells differentiate as T and B lymphocytes.

Animals↗