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PubMed2006

Inflammatory responses to migrating Brugia pahangi third-stage larvae.

Despite being central to parasite establishment and subsequent host pathological and immunologic responses, host-parasite interactions during early third-stage filarial larva (L3) migration are poorly understood. These studies aimed to define early tissue migration of Brugia pahangi L3 in the gerbil (Meriones unguiculatus) and measure host cellular responses during this period. Gerbils were intradermally inoculated in the hind limb with 100 B. pahangi L3, and necropsies were performed at various times. At 3 h, most L3 (96.3%) were recovered from tissues associated with the infection site, with marked L3 migration occurring by 24 h. Larvae were dispersed throughout the lymphatics at 7 days postinfection (dpi), and at 28 dpi, most parasites were recovered from the spermatic cord lymphatics. Parasites were identified histologically at all time points. Inflammatory cells, primarily neutrophils, were frequently observed around larvae in the dermis and muscle near the injection site at 3 h and 24 h. Levels of interleukin-6 (IL-6) and tumor necrosis factor-alpha mRNA peaked at 3 h in all tissues, with IL-6 levels also high in the spleen at 28 dpi. Levels of IL-4 mRNA were elevated in all tissues at 28 dpi. These observations demonstrate that L3 migrate quickly through various tissues and into lymph nodes in a predictable pattern. Migrating L3 induce an early acute inflammatory response that is modulated as parasites establish in the lymphatics. Polarization of the host response towards a dominant Th2-like profile is present at 7 dpi and is well established by 28 dpi in this permissive host.

Animals↗
PubMed2006

Neural stem cells from protein tyrosine phosphatase sigma knockout mice generate an altered neuronal phenotype in culture.

BACKGROUND: The LAR family Protein Tyrosine Phosphatase sigma (PTPsigma) has been implicated in neuroendocrine and neuronal development, and shows strong expression in specific regions within the CNS, including the subventricular zone (SVZ). We established neural stem cell cultures, grown as neurospheres, from the SVZ of PTPsigma knockout mice and sibling controls to determine if PTPsigma influences the generation and the phenotype of the neuronal, astrocyte and oligodendrocyte cell lineages. RESULTS: The neurospheres from the knockout mice acquired heterogeneous developmental characteristics and they showed similar morphological characteristics to the age matched siblings. Although Ptprs expression decreases as a function of developmental age in vivo, it remains high with the continual renewal and passage of the neurospheres. Stem cells, progenitors and differentiated neurons, astrocytes and oligodendrocytes all express the gene. While no apparent differences were observed in developing neurospheres or in the astrocytes and oligodendrocytes from the PTPsigma knockout mice, the neuronal migration patterns and neurites were altered when studied in culture. In particular, neurons migrated farther from the neurosphere centers and the neurite outgrowth exceeded the length of the neuronal processes from age matched sibling controls. CONCLUSION: Our results imply a specific role for PTPsigma in the neuronal lineage, particularly in the form of inhibitory influences on neurite outgrowth, and demonstrate a role for tyrosine phosphatases in neuronal stem cell differentiation.

Animals↗
PubMed1985

[Female migration and social change in Africa. The case of Kenya].

Causes of the recent increase in female rural-urban migration in Kenya are investigated. "Reasons for this additional migration-wave are to be found in a general weakening of traditional values and authorities, the increasing land shortage and the resulting population pressure in the rural areas, which are factors that do in fact force women to migrate to towns." Comparisons are made with male migration flows. Regional differences in migration patterns are also noted. The author concludes that the increase in female migration is not a result of greater emancipation of women but rather a symptom of increasing poverty among Kenya's female population. (SUMMARY IN ENG)

Africa↗
PubMed1991

T-cadherin expression alternates with migrating neural crest cells in the trunk of the avian embryo.

Trunk neural crest cells and motor axons move in a segmental fashion through the rostral (anterior) half of each somitic sclerotome, avoiding the caudal (posterior) half. This metameric migration pattern is thought to be caused by molecular differences between the rostral and caudal portions of the somite. Here, we describe the distribution of T-cadherin (truncated-cadherin) during trunk neural crest cell migration. T-cadherin, a novel member of the cadherin family of cell adhesion molecules was selectively expressed in the caudal half of each sclerotome at all times examined. T-cadherin immunostaining appeared graded along the rostrocaudal axis, with increasing levels of reactivity in the caudal halves of progressively more mature (rostral) somites. The earliest T-cadherin expression was detected in a small population of cells in the caudal portion of the somite three segments rostral to last-formed somite. This initial T-cadherin expression was observed concomitant with the invasion of the first neural crest cells into the rostral portion of the same somite in stage 16 embryos. When neural crest cells were ablated surgically prior to their emigration from the neural tube, the pattern of T-cadherin immunoreactivity was unchanged compared to unoperated embryos, suggesting that the metameric T-cadherin distribution occurs independent of neural crest cell signals. This expression pattern is consistent with the possibility that T-cadherin plays a role in influencing the pattern of neural crest cell migration and in maintaining somite polarity.

Animals↗
PubMed2005

Migration up and down the urban hierarchy and across the life course.

In this article, we begin by reviewing the concept of step migration that originated in E. G. Ravenstein's seminal papers "The Laws of Migration" (1885, 1889). As a result of the forces of the Industrial Revolution underway in 19th century Great Britain, migrants moved from farms to villages, from villages to towns, from towns to county seats, and thence to large cities. Throughout much of the industrialization era in the United States, net population movements similarly were upward within the urban hierarchy, and step migration today remains widespread throughout much of the still developing world. Our investigations of recent data and trends, however, suggest that the latest U.S. migration-pattern regime is a strongly contrasting one. Many of the major movements in the system of internal (or domestic) migration are flows down the urban hierarchy, although we note highly differentiated patterns for persons and households at specific stages of the life course. We make use of the newly defined metropolitan and micropolitan Core-Based Statistical Areas (CBSAs) and a seven-level size typology to tabulate origin-destination-specific migration flow data from both Census 2000 and IRS tax-return administrative records for the period 1995-2000. We discuss the causes for net movements being either upward or downward in the national urban hierarchy, including the effects of spatially focused immigration, and movement preferences at various ages, including migration in young adulthood associated with entering and leaving college and the military, as well as moves characteristic of the stages of family formation, childrearing, and retirement.

Adolescent↗
PubMed1975

Antigen-induced changes in lymphocyte circulatory patterns.

The effect of a splenic or lymph node anti-sheep red blood cell response on lymphocyte migration patterns in mice was studied. It was found that trapping of lymphocytes in these stimulated organs was indiscriminate and was followed by a period of restricted cell entry or localization; furthermore, reduced cell localization in the spleen, during the splenic response, was accompanied by a reduction in the number of cells localizing in unstimulated brachial and axillary lymph nodes. These results were taken to indicate that major changes occur in lymphocyte circulation during strong splenic immune responses.

Animals↗
PubMed1993

Kinetics of hypodermically injected technetium-99m and correlation with cutaneous structures: an experimental study in dogs.

We investigated the involvement of cutaneous structures in specific linear migration pathways of technetium-99m pertechnetate hypodermically injected at points of low electrical resistance in the metacarpus of male beagles. Skin-deep incisions were made in the front or back legs on either the same side as the 99mTc injection or on the opposite side. Incisions in the back legs did not affect the migration pattern. Incisions in the front legs before the injection of 99mTc prevented tracer migration. After the injection of 99mTc, incisions in the front contralateral leg caused sudden cessation of the migration, while incisions in the ipsilateral leg caused immediate disappearance of the pathway previously observed. Radioactivity was not detected in flaps obtained from the skin overlying the migration pathway or from the corresponding area of the contralateral leg. In conclusion, the specific linear migration pathways of 99mTc hypodermically injected at points of low electrical resistance cannot be explained by any known biological function. Although the migration of 99mTc does not seem to be strongly linked to any cutaneous structure, the skin overlying the radioactive pathway and the corresponding area of the contralateral leg must be intact if tracer migration is to take place.

Animals↗
PubMed1987

Inhibitory effect of cetirizine 2HCl on eosinophil migration in vivo.

The effect of a potent antihistamine, cetirizine, was studied on allergic patients and normal subjects by means of an in-vivo 'skin window' technique. All subjects showed significant inhibition of skin-test responses to grass pollen, compound 48/80, histamine and methacholine, after administration of a single dose (10 mg) of cetirizine. Compared to placebo, cetirizine significantly decreased the eosinophils attraction at skin sites challenged with grass pollen and compound 48/80. In allergic patients no change in eosinophil migration pattern was noted with histamine and methacholine skin-tested sites. In normal subjects, compound 48/80 and histamine did not induce eosinophil accumulation and cetirizine did not modify cellular patterns as compared to placebo. These results suggest that cetirizine acts on eosinophil migration by inhibiting the release of mast cell mediators or inhibiting the eosinophilotactic mediators themselves.

Adult↗
PubMed2004

Dynamics of mast cells in lymph node following antigenic stimulation.

Dynamics of mast cells in rat cervical lymph nodes were examined using conventional histological techniques after injection of Salmonella paratyphi B-H antigen. There was no significant change in the number of mast cells at sixth hour and on the first day of stimulation compared with the controls. The number of mast cells was increased in all lymph node compartments on the second day of stimulation, which continued in the following 3 days. On the eighth day of stimulation, although the mast cell number decreased in the subcapsular area, it was still high in the paracortical area and medullary sinuses of the lymph nodes. On the second day of stimulation, the mast cell number was apparently increased in the subcapsular area than those of the other compartments. In the following days of stimulation, the highest number of mast cells was seen in the medullary sinuses. The highest paracortical mast cell number was determined on the third day of stimulation and some mast cells were observed near the high endothelial venules (HEVs). The changes of mast cell number among the lymph node compartments after antigenic stimulation support the hypothesis that the migration of mast cells occurred. This migration pattern indicates that mast cells enter the lymph node via afferent lymphatics and migrate to the lymph node compartments following antigenic stimulation.

Animals↗
PubMed1997

Molecular Epidemiology of Lyme Disease Spirochetes Based on a Probe Complementary to Ribosomal RNA.

Lyme disease is caused by the spirochete, Borrelia burgdorferi, a bacteria which infects many vertebrates including humans. Borrelia have been isolated from many parts of the world, and there is interest to identify common genetic markers to improve molecular methods of diagnosis, and to aid in understanding varied manifestations of the disease. A total of 48 Borrelia burgdorferi strains, including: 38 isolated from ticks (Ixodes dammini, I. persulcatus, I. ricinus and I. pacificus), 3 from animals (dog, bird and hamster), and 7 from human clinical cases (skin, CSF, plasma and blood) from different geographic areas, were studied by DNA/DNA hybridization and rRNA gene restriction patterns by using a biotinylated pKK3535 probe (Altewegg M., Mayer L.W., 1989). The migration patterns of rRNA gene-restriction fragments after clevage by Hind III separate these strains into 5 ribotypes of Borrelia burgdorferi: Type I (38 American,2 European strains); Type II (13 American strains); Type III (3 Asian and 1 European strains); Type IV (1 European and 2 Asian strains) and Type V (1 Asian strain). The use of ribotyping has provided an additional tool to investigate the differences or common patterns which cause various Lyme disease syndromes.

Journal Article↗
PubMed1977

Cells and immunoglobulins in lymph.

Studies of the free-floating lymphocytes and of the immunoglobulins in lymph collected over long periods of time from ducts draining individual tissues of the body as well as from the thoracic duct of the fetus in utero have been reviewed. The findings show that stimuli within the internal milieu act on different classes of lymphocytes to alter their migration pattern, morphology, metabolic activity, and range of immunological potentialities. As the lymphoid cells migrate between the blood, tissue fluid, and lymph, a continual process of reassortment occurs leading to the establishment of heterogeneous lymphoid cell populations in different regions of the lymphatic apparatus. It seems that the biological activities of these cells are not decided only in terms of a thymus or a bone-marrow origin. The immunoglobulins, like other proteins in lymph, are mainly derived by filtration from the circulating plasma. Some of the immunoglobulins and specific antibodies are synthesized, however, by lymphoid cells and secreted directly into the lymph.

Antibody-Producing Cells↗
PubMed1994

Cellular interactions and adhesion molecules in psoriatic skin.

T-cell activation probably plays the most important role in hyperproliferation of keratinocytes in psoriasis. We present here our results concerning the interacting immunocompetent cells and their phenotypic and functional characteristics in relation to psoriasis pathology. Immunohistochemical analysis of skin biopsies from psoriasis patients, did indeed show that hyperproliferation of keratinocytes is associated with increased vasculature and increased influx of MHC class II molecules expressing immunocompetent cells. Furthermore, in psoriasis, several adhesion molecules and other relevant activation markers were found to be upregulated even in the non-lesional psoriatic skin, indicating that psoriatic skin in general is in an activated state. This interpretation is further supported by the observation that the expression of several AR and other relevant activation markers when compared with those in non-lesional skin from contact dermatitis are increased in a significant manner in the non-lesional skin of psoriasis patients. We have then followed up our investigations by generating T-cell lines from lesional psoriatic skin and studied their adhesion patterns on cultured endothelial cells in order to get better insight into the migration pattern of different T cell subsets in psoriasis pathology. Our results indicate that different T-cell subsets CD4+, CD8+ (both TCR-alpha beta+) CD4-/CD8+ TCR-gamma delta+ and CD4-CD8-TCR-gamma delta (V delta 1-) T-cells can easily be generated from psoriatic patients. In a comparative kinetic study using unstimulated and stimulated cultured human umbilical vein endothelial cells, we observed that TCR-gamma delta T cells showed different adhesion properties from that of TCR-alpha beta+ T cell subsets.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Adhesion↗
PubMedDate not supplied

Evidence of an increasing AIDS burden in rural America.

As the AIDS epidemic has matured in the United States, the characteristics of affected populations have shifted from a predominantly white homosexual/bisexual population to one now including increasingly more minorities, injecting drug users and women. Concomitant with the changing nature of persons diagnosed with AIDS there has been an increasing proportion of AIDS cases diagnosed in non-metropolitan areas. Both AIDS incidence and mortality data suggest a possible shift in AIDS from urban to rural areas, and from coastal to interior parts of the country. Migration of persons with AIDS may be contributing to this shift. National strategies for prevention and treatment of AIDS should consider taking into account the geographic behavior of this epidemic. The analysis addresses this issue by summarizing current knowledge regarding the spread of AIDS in rural areas, describing the urban-rural migration patterns from a major U.S. urban epicenter and presenting new NYC data on migration of people with AIDS and previously unpublished AIDS mortality data by state.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Allelic D variants of transferrin in evaluation of alcohol abuse: differential diagnosis by isoelectric focusing-immunoblotting-laser densitometry.

In the diagnosis of alcohol abuse transferrin (Tf) allelic D variants generate false-positive test results for carbohydrate-deficient transferrin (CDT) as assessed by their electrophoretic migration patterns. The predominant Tf C1 allele encodes a protein for which the most prevalent isoform has a pI of 5.4, i.e., four sialic acids and two bound ion molecules. Carriers of allele D encode Tfs with different amino acid sequences, for which the pI is > 5.7, despite their identical iron and carbohydrate composition. We used isoelectric focusing, immunoblotting, and laser densitometry (IEF-IB-LD) to distinguish Tf D variants from CDT. Alcohol abusers carrying the D chi allele tested CDT+; D chi nondrinkers were CDT-. Although normal controls (< 15 g of alcohol per day for 7-10 consecutive days) carrying variants D1, D2, or D chi exhibited abnormal IEF banding patterns, they did not generate false-positive results for CDT. D3 variants expressed isoforms that migrate at the same pI as CDT bands. Thus, IEF-IB-LD yields a highly resolved banding pattern to distinguish most Tf D variants from CDT.

Alcoholism↗
PubMed2001

Migration of cells into and out of peripheral nerve isografts in the peripheral and central nervous systems of the adult mouse.

Peripheral nerve (PN) isografts provide a favourable environment for axon regeneration after peripheral and central nervous system (CNS) injury, but definitive information on the extent of cellular intermixing between donor and host tissues is lacking. We wished to compare migration patterns in fresh and predegenerate PN grafts, and also compare the extent of cell migration after transplantation to peripheral nervous system (PNS) versus CNS. To discern how host and donor cells interact after PN transplantation, sciatic nerve segments were transplanted from inbred adult mice into PN defects (PN-PN grafts) or into lesioned cerebral cortex of opposite gender siblings. Migrating male cells were identified using a Y-chromosome-specific probe and in situ hybridization methods, and characterized immunohistochemically. The extent of donor and host cellular intermixing was similar in fresh and predegenerate PN-PN isografts. There was substantial intermixing of donor and host cells by 8 days. Many host cells migrating into epineurial regions of grafts were immunopositive for F4/80 (macrophages). The endoneurium of grafted PN was also colonized by host cells; some were F4/80+ but many were immunostained with S-100 (Schwann cell marker). Donor S-100+ Schwann cells rapidly migrated out into proximal and distal host PN and by 12 weeks were found at least 2 mm from the grafts. Endoneurial microvessels in grafts were mostly donor-derived. By comparison, in male PN grafts to female CNS, even after 6 weeks few donor cells had migrated out into surrounding host cortex, despite the observation that almost all grafts contained regenerating axons and were thus attached to host CNS tissue.

Animals↗
PubMed1993

Restructuring of the labour market and the role of third world migrations in Europe.

"This paper is an analysis of the way in which the changes in the labour market and in the occupational structure in Europe affect the situation and the role of Third World migrants." Changes in European labor migration patterns since the 1960s are first analyzed. The author notes that "intra-European migrations were industrial migrations because manufacturing and building industries were the most important and growing economic activities....Present-day migrations are postindustrial migrations. Immigrants work mostly in service activities and not infrequently in the informal economy. In any case migrant workers are located in the secondary labour market. The picture is made more complex by the fact than many immigrants are alegal or illegal because of the restrictive immigration policies in European countries."

Demography↗
PubMed1997

Prevalence and characteristics of severe rotavirus infections in Nicaraguan children.

We analyzed the prevalence of rotavirus in 296 children age between 3 and 36 months who were hospitalized in 1994 with severe gastro-enteritis at two health centres for diarrhoea treatment in León, Nicaragua. Enteric viruses were detected in 96 (32.4%) of the children and rotaviruses were the most common pathogens detected in 84 (28%). The majority of rotavirus infections occurred in children less than 1 year old and all strains isolated belonged to subgroup II and had 'long' RNA patterns. Molecular epidemiology of 55 rotavirus strains revealed that all had the same RNA migration pattern and serotyping of 37 strains by PCR technology revealed that all isolates belonged to serotype 3. A significant observation was that only one electropherotype of rotavirus circulated. No non-group A rotaviruses were found by RNA gel electrophoresis. Adenoviruses were found by ELISA in 14 of 265 (5%) children and were most frequently detected during the 1st year of life. Of 103 faecal samples analyzed by electron microscopy, four contained small round structured viruses.

Adenovirus Infections, Human↗
PubMedDate not supplied

Analysis of the rhodopsin and peripherin/RDS gene in two families with pattern dystrophy of the retinal pigment epithelium.

Mutations of the peripherin/retinal degeneration slow (RDS) gene have been reported in autosomal dominant retinitis pigmentosa and variable forms of pattern dystrophy of the retinal pigment epithelium. We screened the rhodopsin and the peripherin/RDS gene in the members of two families who presented the clinical features of pattern dystrophy of the retinal pigment epithelium transmitted as an autosomal dominant trait. No migration patterns were detected in single strand conformation polymorphism or hydrolink gels. Both the rhodopsin and the peripherin/RDS gene were normal in one family. In the second, the proband had a normal rhodopsin gene and, although he passed a different haplotype to each of his affected daughters, there was no linkage with the peripherin/RDS gene. The origin of the retinal disturbance in our two pedigrees must therefore be sought, if indeed DNA is involved, elsewhere in the genome. Our findings provide additional evidence that pattern dystrophies of the retinal pigment epithelium may be pathogenically related in spite of different etiological origins. The genetic polymorphism can probably account for the wide range of phenotypes.

Eye Proteins↗