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PubMed1985

Cellular migration and morphology in corneal endothelial wound repair.

After a mechanical denudation of rabbit corneal endothelial cells, the healing process was followed with wide-field specular microscopy. Individual cell migration and morphologic changes were analyzed by computer-assisted morphometry. The cells surrounding the wound migrated to cover the defect without producing intercellular gaps. The greatest cellular migration and morphologic alterations occurred close to the wound edge. As the cells migrated toward the wound, they elongated and increased their surface area in the direction of the migration. As the healing proceeded, the cells lost their original hexagonal pattern, which returned after coverage was complete. The wound was covered completely by large, irregularly shaped cells showing mitotic figures between 24 and 48 hr. During this period, cellular migration decreased and normal cellular morphology began to recover. When mitosis decreased, the normal cellular pattern rearranged towards a more hexagonal shape. During the healing process, the degree and direction of cellular migration varied from cell to cell. Additionally, changes in cell-to-cell contact (positional changes of neighboring cells) occurred in one-third of migrating cells. Such cellular migration can account for monolayered cells sliding without producing gaps between individual cells.

Animals↗
PubMed2005

Repeated morphine treatment alters polysialylated neural cell adhesion molecule, glutamate decarboxylase-67 expression and cell proliferation in the adult rat hippocampus.

Altered synaptic transmission and plasticity in brain areas involved in reward and learning are thought to underlie the long-lasting effects of addictive drugs. In support of this idea, opiates reduce neurogenesis [A.J. Eisch et al. (2000) Proceedings of the National Academy of Sciences USA, 97, 7579-7584] and enhance long-term potentiation in adult rodent hippocampus [J.M. Harrison et al. (2002) Journal of Neurophysiology, 87, 2464-2470], a key structure of learning and memory processes. Here we studied how repeated morphine treatment and withdrawal affect cell proliferation and neuronal phenotypes in the dentate gyrus-CA3 region of the adult rat hippocampus. Our data showed a strong reduction of cellular proliferation in morphine-dependent animals (54% of control) that was followed by a rebound increase after 1 week withdrawal and a return to normal after 2 weeks withdrawal. Morphine dependence was also associated with a drastic reduction in the expression levels of the polysialylated form of neural cell adhesion molecule (68% of control), an adhesion molecule expressed by newly generated neurons and involved in cell migration and structural plasticity. Polysialylated neural cell adhesion molecule levels quickly returned to normal following withdrawal. In morphine-dependent rats, we found a significant increase of glutamate decarboxylase-67 mRNA transcription (170% of control) in dentate gyrus granular cells which was followed by a marked rebound decrease after 1 week withdrawal and a return to normal after 4 weeks withdrawal. Together, the results show, for the first time, that, in addition to reducing cell proliferation and neurogenesis, chronic exposure to morphine dramatically alters neuronal phenotypes in the dentate gyrus-CA3 region of the adult rat hippocampus.

Animals↗
PubMed2001

BENE, a novel raft-associated protein of the MAL proteolipid family, interacts with caveolin-1 in human endothelial-like ECV304 cells.

The MAL proteolipid, an integral protein present in glycolipid- and cholesterol-enriched membrane (GEM) rafts, is an element of the machinery necessary for apical sorting in polarized epithelial Madin-Darby canine kidney cells. MAL was the first member identified of an extended family of proteins that have significant overall sequence identity. In this study we have used a newly generated monoclonal antibody to investigate an unedited member of this family, named BENE, which was found to be expressed in endothelial-like ECV304 cells and normal human endothelium. Human BENE was characterized as a proteolipid protein predominantly present in GEM rafts in ECV304 cells. Coimmunoprecipitation experiments revealed that BENE interacted with caveolin-1. Confocal immunofluorescence and electron microscopic analyses indicated that BENE mainly accumulated into intracellular vesicular/tubular structures that partially colocalize with internal caveolin-1. In response to cell surface cholesterol oxidation, BENE redistributed to the dilated vesicular structures that concentrate most of the caveolin-1 originally on the cell surface. After cessation of cholesterol oxidation, a detectable fraction of the BENE molecules migrated to the plasmalemma accompanying caveolin-1 and then returned progressively to its steady state distribution. Together, these features highlight the BENE proteolipid as being an element of the machinery for raft-mediated trafficking in endothelial cells.

Amino Acid Sequence↗
PubMed2003

Dementia paralytica (neurosyphilis): a clinical case study.

This study reminds clinicians that syphilis presents in many guises. Wars, migration and sexual promiscuity prepare the ground for its return as an important cause of neurological and psychiatric syndromes. Our patient's diagnosis was not suspected at earlier admission. Stage III spirochaetosis was improved by high dose penicillin.

Alcoholism↗
PubMed1996

Worldwide patterns of mitochondrial DNA differentiation in the harbor seal (Phoca vitulina).

The harbor seal (Phoca vitulina) has one of the broadest geographic distributions of any pinniped, stretching from the east Baltic, west across the Atlantic and Pacific Oceans to southern Japan. Although individuals may travel several hundred kilometers on annual feeding migrations, harbor seals are generally believed to be philopatric, returning to the same areas each year to breed. Consequently, seals from different areas are likely to be genetically differentiated, with levels of genetic divergence increasing with distance. Differentiation may also be caused by long-standing topographic barriers such as the polar sea ice. We analyzed samples of 227 harbor seals from 24 localities and defined 34 genotypes based on 435 bp of control region sequence. Phylogenetic analysis and analysis of molecular variance showed that populations in the Atlantic and Pacific Oceans and east and west coast populations of these oceans are significantly differentiated. Within these four regions, populations that are geographically farthest apart generally are the most differentiated and often do not share genotypes or differ in genotype frequency. The average corrected sequence divergence between populations in the Atlantic and Pacific Oceans is 3.28% +/- 0.38% and those among populations within each of these oceans are 0.75% +/- 0.69% and 1.19% +/- 0.65%, respectively. Our results suggest that harbor seals are regionally philopatric, on the scale of several hundred kilometers. However, genetic discontinuities may exist, even between neighboring populations such as those on the Scottish and east English coasts or the east and west Baltic. The mitochondrial data are consistent with an ancient isolation of populations in both oceans, due to the development of polar sea ice. In the Atlantic and Pacific, populations appear to have been colonized from west to east with the European populations showing the most recent common ancestry. We suggest the recent ancestry of European seal populations may reflect recolonization from Ice Age refugia after the last glaciation.

Animals↗
PubMed2006

Characterization of ileal dendritic cell distribution in a rat model of acute and chronic inflammation.

We examined ileal dendritic cell (DC) subpopulations in a rat model of indomethacin-induced enteritis to determine changes in phenotype and distribution associated with increased mucosal permeability during acute and chronic stages of inflammation. Sprague-Dawley rats were treated with indomethacin (7.5 mg/kg subcutaneously, 2 injections 48 h apart). Animals were killed at day 4 (acute stage) or at day 15 or 30 (chronic stages); control rats were injected with saline. DC distribution was evaluated by immunohistochemistry for CD103, CD11b, CD83, and CD163; inflammation was assessed by light microscopy; and permeability was determined by flux of horseradish peroxidase in Ussing chambers. In controls, both immature DC subpopulations, CD103+CD11b+CD163-CD83- and CD103+CD11b-CD163-CD83-, were observed in the lamina propria, and the CD11b- population also was present in Peyer's patches. In acute inflammation, permeability was increased (P<0.01), and inflamed areas with or without ulcers were observed. CD103+ and CD11b+ (CD83-) DCs were absent from inflamed areas, reduced in noninflamed tissues, but present in Peyer's patches. In the chronic stage at day 15, CD103+ and CD11b+ cells were located in inflamed and noninflamed areas and in Peyer's patches. In addition, CD83+ DCs were detected in inflamed areas. At day 30, when we observed a complete microscopic resolution of inflammation, numbers of CD103+ and CD11b+ DCs were increased, and there were CD83+ DCs beneath the epithelial cell layer. We conclude that antigen uptake in acute inflammation may activate resident immature DCs, inducing their migration to lymphoid tissue where they mature and then return to the intestine to play a role in the local inflammatory response.

Acute Disease↗
PubMed2006

Evidence of influenza a virus RNA in siberian lake ice.

Influenza A virus infects a large proportion of the human population annually, sometimes leading to the deaths of millions. The biotic cycles of infection are well characterized in the literature, including in studies of populations of humans, poultry, swine, and migratory waterfowl. However, there are few studies of abiotic reservoirs for this virus. Here, we report the preservation of influenza A virus genes in ice and water from high-latitude lakes that are visited by large numbers of migratory birds. The lakes are along the migratory flight paths of birds flying into Asia, North America, Europe, and Africa. The data suggest that influenza A virus, deposited as the birds begin their autumn migration, can be preserved in lake ice. As birds return in the spring, the ice melts, releasing the viruses. Therefore, temporal gene flow is facilitated between the viruses shed during the previous year and the viruses newly acquired by birds during winter months spent in the south. Above the Arctic Circle, the cycles of entrapment in the ice and release by melting can be variable in length, because some ice persists for several years, decades, or longer. This type of temporal gene flow might be a feature common to viruses that can survive entrapment in environmental ice and snow.

Base Sequence↗
PubMed2002

Landmark use and development of navigation behaviour in the weakly electric fish Gnathonemus petersii (Mormyridae; Teleostei).

African mormyrids, such as Gnathonemus petersii, migrate: nocturnally, from daytime shelters to find food and return by morning, and seasonally, spawning in swamps flooded during the rainy season. The present study examined whether the fish use landmarks detected via electrolocation to locate an aperture, whether they detect changes in landmark size and respond appropriately, whether landmarks or hydrostatic pressure are the primary cues for navigation and whether fish of different developmental stages behave differently with respect to landmarks and navigation. The fish's task was to locate and swim through a circular aperture in a wall dividing an aquarium into two compartments. Two groups of fish were trained to find the aperture with a landmark present, while a control group had no such landmark. The water level remained constant throughout training. At the end of training, the fish's task was to locate the aperture after the landmark size had changed or the water level had increased. The results show that G. petersii use landmarks to orient and navigate. They can detect changes in landmark size and will modify their locomotor behaviour to integrate the change into an internal representation. If the water level changes, increasing hydrostatic pressure, the fish orient to a landmark, if present. If no landmark is present, the fish rely on an internal representation oriented to hydrostatic pressure. Larger, early-adult G. petersii located the aperture faster than smaller, sub-adult fish.

Animals↗
PubMed1990

Transient paraplegia caused by acute aortic dissection--case report.

A case of acute aortic dissection (AAD) presenting as sudden, transient paraplegia and severe back pain is reported. The patient was a 66-year-old male with a 10-year-history of hypertension. The pain characteristically migrated from the back to the neck and then returned to the back. He showed complete transverse myelopathy at the level of the 9th thoracic cord. Computed tomography disclosed internal displacement of aortic intimal calcifications, without abnormalities in the spinal canal, and myelography showed no spinal canal block or stenosis. Electrocardiography and chest x-ray indicated nonspecific changes of high amplitudes and mild cardiomegaly, respectively. Together, these findings suggested acute aortic dissection with spinal cord ischemia. The initial systolic blood pressure of 220 mmHg was lowered with medication, and the pain was controlled with morphine. He recovered fully and was discharged 80 days after the onset of symptoms, with no neurological deficits. AAD carries a very poor prognosis unless treated immediately. Therefore, it is very important to promptly differentiate this disorder from spinal vascular conditions that also produce back pain and paraparesis.

Aged↗
PubMed1989

An infrared study of the binding and photodissociation of carbon monoxide in cytochrome ba3 from Thermus thermophilus.

The C-O stretching frequencies of fully reduced carbonmonoxy cytochrome ba3, a newly discovered terminal oxidase of the bacterium Thermus thermophilus (Zimmermann, B.H., Nitsche, C.I., Fee, J.A., Rusnak, F., and Münck, E. (1988) Proc. Natl. Acad. Sci. U.S. A. 85, 5779-5783), are studied by Fourier transform infrared spectroscopy. Multiple C-O frequencies are observed in the Fourier transform infrared spectra, indicating the presence of discrete interconverting conformers of the enzyme. Upon photolysis, the CO is shown to migrate exclusively to CuB+. Above 200 K, the CO returns to the heme a3 by a thermal process which follows simple first-order kinetics. The rate of the reaction was studied from 205 to 230 K and at 300 K, yielding the activation parameters delta H = 14.9 kcal/mol and delta S = -5 cal/mol/K. These are compared with previously determined activation parameters for CO recombination in mitochondrial cytochrome aa3 preparations (Fiamingo, F.G., Altschuld, R.A., Moh, P.P., and Alben, J.O. (1982) J. Biol. Chem. 257, 1639-1650). We report the novel finding that CO remains bound to CuB+ at room temperature during continuous photolysis of cytochrome ba3, and we conjecture on the possible interference of copper-bound CO in "flow-flash" and "triple-trap" studies of cytochrome c oxidases.

Calorimetry↗
PubMed1979

A case of meglumine iodipamide hepatotoxicity.

There have been only two reports of severe hepatotoxic reaction caused by meglumine iodipamide. Lately we experienced such a reaction in an 66-year old female with chronic intrahepatic cholestasis. After drip infusion cholangiography was performed by infusing 40 ml. of 50% meglumine iodipamide (Biligrafin) intravenously, the patient developed nausea and abdominal pain. Her serum transaminase rose to more than 2,000 K-A units on the third day and gradually returned to normal by the 18th day. The macrophage migration inhibition test of her blood was positive for meglumine iodipamide. Accordingly some delayed type of hypersensitivity in the above reaction could be considered. When a larger amount than a recommended dose of meglumine iodipamide is infused in cholangiography, a severe hepatotoxic reaction might be induced, especially in icteric cases.

Aged↗
PubMedDate not supplied

[The biogeochemistry of the radionuclides of the Chernobyl release in the forest ecosystems of the European portion of the CIS].

The 9-years dynamic of Chernobyl-derived radionuclides in the vegetation and soil covers of the forest ecosystems of the European part of the CIS is considered. The quantitative estimation has been done for main fluxes of Cs-137 in the forests of automorphic landscapes: influx to the vegetation, return with the litterfall, stem flow and throughfall, vertical migration in the soil profile (including intrasoil flow), and redistribution within the system of geochemically connected landscapes.

Commonwealth of Independent States↗
PubMed1989

Neutrophil chemotaxis, random migration, and adherence in patients with hyperthyroidism.

We have examined neutrophil adherence, chemotactic activity, and random migration in 35 hyperthyroid patients with Graves' disease and 106 normal volunteers. No statistically significant differences were found between granulocyte adherence of 17 hyperthyroid subjects (67 +/- 15.6%) and 81 healthy volunteers (63.1 +/- 17%). In 3 thyrotoxic patients, impaired neutrophil adherence was found, which resolved when thyroid function returned to normal. The neutrophil chemotactic activity of 32 normal controls was 107.5 +/- 21.4 cells, and the random migration 36 +/- 15.5 cells. No statistically significant difference was demonstrated in 13 hyperthyroid patients who had a neutrophil chemotactic activity of 102 +/- 14.6 cells and a random migration of 31.2 +/- 13.2 cells. Defective chemotactic activity and random migration was found in 2 patients. Neutrophil functions returned to normal in one of the two subjects who were re-evaluated when thyroid function recovered. In summary, 14% of hyperthyroid patients had impaired leukocyte functions. However, severe pyogenic infections are quite rare in hyperthyroid patients, indicating that the observed alterations in function of phagocytic cells are not clinically important.

Cell Migration Inhibition↗
PubMed1992

Self-selection and internal migration in the United States.

"Within the conceptual framework of the Roy model, this paper provides an empirical analysis of internal migration flows [in the United States] using data from the National Longitudinal Survey of Youth. The theoretical approach highlights regional differences in the returns to skills: regions that pay higher returns to skills attract more skilled workers than regions that pay lower returns. Our empirical results suggest that interstate differences in the returns to skills are a major determinant of both the size and skill composition of internal migration flows. Persons whose skills are most mismatched with the reward structure offered by their current state of residence are the persons most likely to leave that state, and these persons tend to relocate in states which offer higher rewards for their particular skills."

Americas↗
PubMed1984

Functional and ultrastructural changes in neutrophils from mares and foals experimentally inoculated with a respiratory tract strain of equine herpesvirus-1.

Neutrophils isolated from venous blood of adult and foal ponies inoculated with equine herpesvirus-1 were evaluated by in vitro function tests and by electron microscopy. Foals had fever and severe neutropenia 24 hours after inoculation; increased neutrophil random migration under agarose and decreased antibody-dependent cell-mediated cytotoxicity were significant at 24 hours, but values had returned to preinoculation levels by 72 hours. Mares had fever and leukopenia of less severity, increases in neutrophil migration, and longer persistence of primary granule release than were seen in foals. Reduced migration and degranulation, and a decrease in antibody-dependent cell-mediated cytotoxicity seen with neutrophils from foals, as compared with mares, may relate to the high susceptibility of foals to equine herpesvirus-1 infection.

Animals↗
PubMed1986

Perinuclear location and recycling of epidermal growth factor receptor kinase: immunofluorescent visualization using antibodies directed to kinase and extracellular domains.

This paper describes studies on the migratory behavior of epidermal growth factor (EGF) receptor kinase using antibodies that are specific for either the kinase domain or the extracellular domain of the receptor. Antiserum was raised to a 42,000-D subfragment of EGF receptor, which was shown earlier to carry the kinase catalytic site but not the EGF-binding site. Another antiserum was raised to the pure intact 170,000-D EGF receptor. The specificities of these antibodies were established by immunoprecipitation and immunoblotting experiments. The domain specificity was examined by indirect immunofluorescent staining of fixed cells. The anti-42-kD peptide antibody could bind specifically to EGF receptors of both human and murine origin and was found to be directed to the cytoplasmic part of the molecule. It did not bind to EGF receptor-negative cells, which contained other types of tyrosine kinases. The antibodies raised against the intact receptor recognized only EGF receptor-specific epitopes and were directed to the extracellular part of the molecule. The anti-receptor antibodies described above were used to visualize the cyclic locomotory behavior of EGF receptor kinase under various conditions of EGF stimulation and withdrawal. The receptor was examined in fixed and permeabilized cells by indirect immunofluorescent staining. The results demonstrate the following: (a) the receptor kinase domain migrates to the perinuclear region upon challenge with EGF; (b) both extracellular and cytoplasmic domains of the receptor are involved in migration as a unit; (c) withdrawal of EGF results in rapid recycling of the perinuclear receptors to the plasma membrane; (d) this return to the cell surface is inhibited by methylamine, chloroquine, and monensin; and (e) neither the internal migration nor the recycling process is blocked by inhibitors of protein biosynthesis.

Animals↗
PubMed2006

Phylogeography of Brachyplatystoma rousseauxii (Siluriformes - Pimelodidae) in the Amazon Basin offers preliminary evidence for the first case of "homing" for an Amazonian migratory catfish.

The large pimelodid, Brachyplatystoma rousseauxii, is one of the two most important catfish species for the fisheries in the Amazon. It is captured by commercial and artisanal fishing fleets in at least five Amazonian countries, at fishing grounds more than 5000 km apart. Current evidence suggests a complex life cycle that includes the longest reproductive migration known for a freshwater fish species. Experimental fisheries have pointed to a decrease in yield in the Western Amazon. However, reliable information about the capture and status of this fishery resource is still nonexistent, and no study has ever addressed its genetic diversity. We sequenced the entire D-loop of 45 individuals of B. rousseauxii, fifteen from each of three different fishing locations along the main channel of the Solimões-Amazonas System covering a distance of around 2200 km. Results of phylogenetic analyses, molecular diversity estimations, analysis of molecular variance, and nested clade analysis, together show that there is no genetic segregation associated with location in the main channel, as one would expect for a migratory species. However, the significant decrease found in genetic diversity towards the western part of the Amazon could be explained by a non-random choice of tributary to spawn. It is possible that the genetic diversity of the migrating schools decreases towards the west because portions of the species' genetic diversity are being "captured" by the different effluents, as the fish migrates to spawn in the headwaters. Like the salmon in North America, B. rousseauxii may be returning to their home tributary to spawn.

Animal Migration↗
PubMed1992

Take the money and sun: elderly migration as a consequence of gains in unaffordable housing markets.

We tested the hypothesis that elderly migration, both seasonal and permanent, to Sunbelt states such as Arizona is the result, in part, of economic gains made in unaffordable housing markets. The results of a multiple regression analysis of interstate migration flows to Arizona support the hypothesis. Moreover, the stronger relationship for seasonal migration suggests that elderly households are unwilling to realize housing gains in unaffordable markets but, nevertheless, "spend" the gains on seasonal migration. Such behavior is rational if housing is viewed as an investment and expectations of future returns are greater in unaffordable markets. Given that the study was based on housing gains of the 1970s, the results suggest that more recent elderly migration may be even more influenced by such gains, inasmuch as regional differences in housing affordability have become more pronounced.

Aged↗