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PubMed1990

Importance of rotavirus and adenovirus types 40 and 41 in acute gastroenteritis in Korean children.

To examine the role of rotavirus (Rv) and adenovirus types 40 and 41 (Ad40/41) in Korean children with acute gastroenteritis, we evaluated 345 children with acute gastroenteritis and 90 children without acute gastroenteritis in Seoul, Korea, during a 29-month period. Stools were tested for group A Rv antigen and for Ad40/41 by using monoclonal antibody (MAb)-based assays. Rv was found in 68% of the ill children and 19% of the controls (P less than 0.001), whereas Ad40/41 was detected in 9% of the ill children and 2% of the controls (P less than 0.05). Also, 6% of the ill children and 0.01% of the controls excreted Rv and Ad40/41 simultaneously. Among the ill children, 96% of children with Rv and 94% of those with Ad40/41 were younger than 24 months. Although a peak of Rv infection was detected in early winter in both years of the study, there was no apparent seasonal trend with Ad40/41. Diarrhea with more than 10 stools per day, vomiting, or fever was most strongly associated with Rv shedding, whereas the first two manifestations were associated with coinfection of Rv and Ad40/41. To investigate the genetic and serotypic diversity of Rv strains, we tested 195 and 144 fecal Rv specimens isolated from the gastroenteritis cases, respectively, by polyacrylamide gel electrophoresis of the segmented RNA genome and by an enzyme-linked immunosorbent assay with serotype-specific MAbs. Of the 195 specimens, 154 yielded RNA patterns characteristic of group A Rv: 18% had short electrophoretic migration patterns, 81% had long patterns, and 1% had a mixture of short and long patterns. Of the 144 specimens, serotype specificity was determined in 51%: 89% were serotype 1, 10% were serotype 2, and 1% were serotype 3. Analysis of the specimens for which electropherotypes and serotypes were available indicated that a given RNA pattern corresponded to a particular serotype, except in one strain that showed short patterns but serotype 1. We suggest that Rv and Ad40/41 in stools be accepted critically as an important cause of diarrhea among young children in Korea.

Acute Disease↗

PubMed1998

Sensory development and its relation to habitat change in three species of sciaenids.

Visual and mechanosensory development of three sciaenid species was investigated to examine possible correlations between sensory morphology and patterns of habitat use. Although the three species have different migration patterns as early larvae, few differences in sensory morphology occurred between species until late in the larval period. Atlantic croaker, Micropogonias undulatus, were distinguished by enhancements of visual morphology (large eyes, abundant photoreceptors, and best summation of the three species). Croaker arrive inshore later in the larval period and, after settlement, appear to use deeper water habitats than do the other two species. Spotted seatrout, Cynoscion nebulosus, had the fewest enhancements of visual morphology but had more free neuromasts than the other two species late in the larval period. After settlement, seatrout are primarily associated with seagrass habitats. Red drum, Sciaenops ocellatus, did not have pronounced specialization of one sensory system, as did the other two species. For part of the larval period, neuromast numbers were higher in red drum than in the other two species. Later, enhancements of visual morphology did occur, but only eye and lens size were the same as those of Atlantic croaker. Red drum larvae appear to use a wider variety of habitats than do the other two species. In none of the species examined did sensory changes correlate with offshore to inshore movements, and only initial rod formation occurred prior to settlement. Distinct sensory changes did not occur concurrent with habitat changes, probably due to constructional and phylogenetic constraints. Rather, sensory differences are related to the environmental conditions in the predominant inshore habitat occupied by each species after settlement, when morphological limitations are less severe.

Animals↗

PubMed1994

Determinants of the demographic impact of HIV-1 in sub-Saharan Africa: the effect of a shorter mean adult incubation period on trends in orphanhood.

Recent evidence suggests that the adult HIV-1 incubation period may be shorter in some sub-Saharan African populations than in Western populations. In this article we use mathematical-model-based simulations to show that, other things being equal, a shorter incubation period can result in smaller but more pronounced HIV-1 epidemics and faster, more acute, changes in demographic features, such as adult mortality, orphanhood and population structure. Empirical studies of orphanhood reveal similar patterns to those found in the simulations, but suggest that migration patterns and structural factors can give rise to greater concentrations of orphans in areas of relatively low HIV-1 prevalence.

Adolescent↗

PubMed1999

Migradollars and mortality: the effects of migration on infant survival in Mexico.

We apply multilevel methods to data from Mexico to examine how village migration patterns affect infant survival outcomes in origins. We argue that migration is a cumulative process with varying health effects at different stages of its progression, and test several related hypotheses. Findings suggest higher rates of infant mortality in communities experiencing intense U.S. migration. However, two factors diminish the disruptive effects of migration: migradollars, or migrant remittances to villages, and the institutionalization of migration over time. Mortality risks are low when remittances are high and decrease as migration becomes increasingly salient to livelihoods of communities. Together, the findings indicate eventual benefits to all infants, irrespective of household migration experience, as a result of the development of social and economic processes related to U.S. migration.

Adult↗

PubMed1997

Characterisation of the immune response in a neural xenograft rejection paradigm.

We have looked at both donor and host MHC expression in a neural xenograft rejection paradigm. Grafts of either mouse corpus callosum or an SV40 large T transformed astrocytic cell line were placed in the mid-brain of neonatal rats. Three weeks later graft rejection was induced by the application of a skin graft of the same donor origin. MHC expression in the neural graft and the host brain was examined histologically four and ten days after the animals had received a skin graft. Donor MHC expression was detected in the corpus callosal grafts at both time points and preceded host MHC expression and the lymphocytic infiltrate. The grafts of the transformed cell line could not be induced to express MHC antigens under the experimental protocol used nor were they rejected. The migratory patterns of the transformed cells were compared to the well characterised migration patterns of astrocytes from the corpus callosal grafts.

Animals↗

PubMed1999

Capillary electrophoresis of N-acetylneuraminic acid polymers and hyaluronic acid: correlation between migration order reversal and biological functions.

High-resolution analysis of polymers of N-acetylneuraminic acid and hyaluronic acid was performed by capillary electrophoresis in a buffer containing a neutral polymer. Both polysaccharides having more than 100 monosaccharide residues were well separated into their molecular species by capillary electrophoresis using a combination of a chemically modified capillary and a buffer containing poly(ethylene glycol) as an additive. During optimization of the separation conditions, small oligomers of both polysaccharides were observed to migrate in the reverse order of their molecular masses on the electropherograms. However, oligomers larger than pentamer and decamer for N-acetylneuraminic acid polymers and hyaluronic acid, respectively, migrated in the order of their molecular masses. We propose that these unusual migration patterns are closely related to the stereochemical structures and the oligomer migrating the fastest is the minimum unit that forms the regular three-dimensional structure required for the biological function.

Carbohydrate Sequence↗

PubMed1994

Enhanced T cell migration to sites of microscopic CNS disease: complementary treatments evaluated by 2- and 3-D image analysis.

Novel therapies are being developed to attack tumour or other abnormal cells within the brain. A general problem is the need for delivery to sites of microscopic disease. Leukocytes offer an attractive solution; they are able to both move through tissue and recognize abnormal targets. Leukocytes may act as effectors, or as vehicles for drugs, retroviral vectors or other agents. Here, we illustrate complementary ways of enhancing leukocyte migration to sites of microscopic central nervous system (CNS) disease. Enhanced T cell migration to sites of disseminated tumour is used as the example. Computer-assisted image analysis is used to evaluate migration patterns in 2 and 3 dimensions. Shared regulatory features in the migration of tumour and responding cells, and the opportunities and questions they imply, are discussed.

Brain Diseases↗

PubMed1992

Effects of epidermal growth factor, fibroblast growth factor, and transforming growth factor-beta on corneal cell chemotaxis.

The effects of recombinant basic fibroblast growth factor (FGF), epidermal growth factor (EGF), and transforming growth factor-beta (TGF-beta) on migration of human and bovine corneal cells were determined using checkerboard analysis in Boyden chambers. EGF, FGF, and TGF-beta each stimulated high levels of chemotactic migration. Each growth factor, however, induced a different dose-response pattern. Migration stimulated by FGF reached a plateau at a concentration between 100 and 200 ng/ml for endothelial, epithelial, and stromal fibroblasts. By contrast, chemotactic responses to EGF peaked between 10 and 50 ng/ml, then decreased at higher concentrations. TGF-beta also stimulated a peak in migration in all three corneal cells, but the peak of migration occurred at an approximately 1000-fold lower concentration (1 pg/ml) than for EGF. Checkerboard analysis demonstrated that FGF and EGF, but not TGF-beta, stimulated chemokinesis of bovine, stromal, and endothelial cells. These results demonstrate that FGF, EGF, and TGF-beta induce migration in pure populations of bovine and human corneal cells and support the concept that these growth factors may play key roles in corneal wound healing by regulating migration of corneal cells.

Animals↗

PubMed1981

In vitro migration of potential hemopoietic precursors from the murine fetus.

An in vitro migration system demonstrated the presence in murine fetal tissues of cells that migrate to thymus, spleen or lymph node. Preincubation of these cells with facteur thymique sérique, a factor derived from the thymus, produced changes in the migration patterns, suggesting a maturation sequence in fetal hemopoietic precursor-cell migration capacity, with migration to the thymus as the initial potential homing target, followed in order by a potential to migrate to the spleen, than to lymph-node tissue.

Animals↗

PubMed1994

Genomic characterization of rotavirus strains obtained from hospitalized children with diarrhoea in Bangladesh.

Faecal samples were obtained from 111 children hospitalized with acute watery gastroenteritis in a children's hospital in Bangladesh from January to December, 1989. Rotavirus was detected as the aetiologic agent in 35 (32%) of these patients. The electrophoretic pattern of ds-RNA extracted from the rotaviruses showed 11 different migration patterns (six short and five long), as well as some short and long mixed profiles. All four major G serotypes were identified by amplification of a segment of the gene for VP7 using the polymerase chain reaction. A specific serotype could be assigned in 32 (91%) cases. Serotypes G1-G4 accounted for 11%, 37%, 11%, and 23% of isolates respectively. Three (9%) mixed serotypes were identified by this method and were found to be mixtures of serotypes G1 and G4, G2 and G4, and G3 and G4.

Adolescent↗

PubMed1983

Isolation of a cell surface receptor protein for laminin from murine fibrosarcoma cells.

We used affinity chromatography to isolate a specific laminin-binding protein from murine fibrosarcoma cells. These cells bind exogenous laminin to their surface with high affinity (Kd = 2 X 10(-9)M for laminin) with approximately 5 X 10(4) sites per cell. Laminin affinity chromatography of [35S]methionine-labeled cell extracts produced two distinct proteins. One was identified as Type IV (basement membrane) collagen based on its migration pattern on SDS gels and bacterial collagenase sensitivity. The other protein, which migrates as a single band or closely spaced doublet on reduced SDS gels, has a reduced molecular weight of 69,000. Using a nitrocellulose filter disk assay, we found that the latter protein specifically bound 125I-laminin with the same high affinity (Kd = 2 X 10(-9)M for laminin) as did intact fibrosarcoma cells. By iodinating intact cells, we demonstrated that this laminin-binding protein is on the cell surface. We conclude that this protein with reduced molecular weight of 69,000 is a subunit or component of a larger cell surface receptor protein for laminin in this fibrosarcoma model. This laminin receptor may mediate the interaction of the cell with its extracellular matrix.

Animals↗

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↗

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↗

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↗