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PubMed1992

The "rejection reaction" is not confined solely to the allograft.

The rejection process refers primarily to the destruction of foreign tissues by host immune mechanisms. This process affects host lymphoid tissue profoundly and alters the migration patterns of lymphocytes in recipients of organ allografts. It has been shown that specifically sensitized lymphocytes traffic both to and from the transplant. A considerable amount of knowledge has been gathered on the preferential migration pathways of lymphocytes through lymphoid and mucosa-associated lymphoid organs. The factors regulating lymphocyte migration through non-lymphoid tissue in normal conditions are not well known and even less well understood in the context of graft rejection. In this article we described for the first time migration in a recipient non-lymphoid organ (heart) and it's potentially harmful effects in causing parenchymal damage during renal allograft rejection in the rat model. These lesions were detected during the process of developing a model of chronic renal allograft rejection. The pathogenesis of these cardiac lesions is not fully understood but possible mechanisms include upregulation of homing receptors/adhesion molecules, breakdown of peripheral tolerance and involvement of cross-reacting anti-endothelial antibodies.

Animals↗
PubMed2000

Developmental dynamics of peripheral glia in Drosophila melanogaster.

To study the roles of peripheral glia in nervous system development, a thorough characterization of wild type glial development must first be performed. We present a developmental profile of peripheral glia in Drosophila melanogaster that includes glial genesis, developmental morphology, the establishment of transient cellular contacts, migration patterns, and the extent of nerve wrapping in the embryonic and larval stages. In early embryonic development, immature peripheral glia that are born in the CNS seem to be intermediate targets for neurites that are migrating into the periphery. During migration to the PNS, peripheral glia follow the routes of pioneer neurons. The glia preferentially adhere to sensory axonal projections, extending cytoplasmic processes along them such that by the end of embryogenesis peripheral glial coverage of the sensory system is complete. In contrast, significant lengths of motor branch termini are unsheathed in the mature embryo. During larval stages however, peripheral glia further extend and elaborate their cytoplasmic processes until they often reach to the neuromuscular junction. Throughout the embryonic and larval developmental stages, we have also observed a number of similarities of peripheral glia to vertebrate Schwann cells and astrocytes. Peripheral glia seem to have dynamic and diverse roles and their similarities to vertebrate glia suggest that Drosophila may serve as a powerful tool for analysis of glial roles in PNS development in the future.

Animals↗
PubMed2004

Prostate brachytherapy seed migration and dosimetry: analysis of stranded sources and other potential predictive factors.

PURPOSE: The purpose of this study was to evaluate the influence of potential contributing factors to the incidence of seed migration and quality of prostate brachytherapy dosimetry. METHODS AND MATERIALS: Sixty patients were evaluated with day one and 3-12 month plain films of the pelvis and chest, and day 1 CT-based dosimetry analysis. The incidence and types of seed migration were quantified. The seed migration outcome was evaluated with respect to source type (free vs. stranded), prostate volume, number of seeds, and needles. The day one prostate V100, V150, D90, and urethra D10 outcomes were evaluated with respect to source type, radiation type ((125)I vs. (103)Pd), prostate volume, prostate swelling, and quantity of migrating seeds. RESULTS: An increased incidence of day one and cumulative seed migration was predicted by free vs. stranded source type, with a relative risk of 6.97 and 3.08, respectively. Pulmonary and distal (toward the perineum) migration patterns were significantly reduced in the stranded group. An increased day one prostate V100, V150, D90, and urethra D10 outcome was predicted by stranded source type. CONCLUSION: Stranded source type was associated with decreased seed migration as well as higher prostate and urethra dosimetry values, resulting in an implant in which more radiation resided within the target volume, and less radiation metastasized to undesirable locations.

Brachytherapy↗
PubMed1999

Body-building without power training: endogenously regulated pectoral muscle hypertrophy in confined shorebirds

Shorebirds such as red knots Calidris canutus routinely make migratory flights of 3000 km or more. Previous studies on this species, based on compositional analyses, suggest extensive pectoral muscle hypertrophy in addition to fat storage before take-off. Such hypertrophy could be due to power training and/or be effected by an endogenous circannual rhythm. Red knots of two subspecies with contrasting migration patterns were placed in a climate-controlled aviary (12 h:12 h L:D photoperiod) where exercise was limited. Using ultrasonography, we measured pectoral muscle size as the birds stored fat in preparation for migration. At capture, there were no differences in body mass and pectoral muscle mass between the two subspecies. As they prepared for southward and northward migration, respectively, the tropically wintering subspecies (C. c. canutus) gained 31 g and the temperate wintering subspecies (C. c. islandica) gained 41 g. During this time, pectoral mass increased by 43-44 % of initial mass, representing 39 % (C. c. canutus) and 29 % (C. c. islandica) of the increase in body mass. The gizzard showed atrophy in conjunction with a diet change from molluscs to food pellets. Although we cannot exclude the possibility that the birds' limited movement may still be a prerequisite for pectoral muscle hypertrophy, extensive power training is certainly not a requirement. Muscle hypertrophy in the absence of photoperiod cues suggests the involvement of an endogenous circannual process.

Journal Article↗
PubMed1993

The growth of mouse hybridoma cells between Peyer's patch lymphocyte and myeloma cell in the gastrointestinal tract. A model for human multiple lymphomatous polyposis of the gastrointestinal tract.

To elucidate the mechanism of multiple lesions in human primary lymphoma or multiple lymphomatous polyposis of the gastrointestinal tract, we developed a experimental model utilizing mouse hybridoma cells. Syngeneic mice were immunized with human hemoglobin via gastric intubation and a hybridoma clone (13c) between the Peyer's patch cell and mouse myeloma cell was obtained. The 13c cells were infused into normal syngeneic mice through a lateral tail vein. About 2 months after injection mice were sacrificed and their viscera were scrutinized histologically. All 11 mice receiving 13c showed multiple tumors at the colon, microscopic massive invasions at the small intestine, and scattered invasions at Peyer's patch, mesenteric lymph nodes and the spleen, exhibiting the similar distribution patterns as in human multiple lymphomatous polyposis of the gastrointestinal tract. ME-1 or MU-1 cells (hybridomas between P3 and mouse spleen cell) were distributed at the liver, spleen and paraaortic lymph nodes. Such migration patterns of 13c cells and their adherence to vessel walls suggest that multiple invasions may be lymphocyte homing receptor-mediated phenomena.

Animals↗
PubMed1997

Receptor tyrosine kinase-dependent neural crest migration in response to differentially localized growth factors.

How different neural crest derivatives differentiate in distinct embryonic locations in the vertebrate embryo is an intriguing issue. Many attempts have been made to understand the underlying mechanism of specific pathway choices made by migrating neural crest cells. In this speculative review we suggest a new mechanism for the regulation of neural crest cell migration patterns in avian and mammalian embryos, based on recent progress in understanding the expression and activity of receptor tyrosine kinases during embryogenesis. Distinct subpopulations of crestderived cells express specific receptor tyrosine kinases while residing in a migration staging area. We postulate that the differential expression of receptor tyrosine kinases by specific subpopulations of neural crest cells allows them to respond to localized growth factor ligand activity in the embryo. Thus, the migration pathway taken by neural crest subpopulations is determined by their receptor tyrosine kinase response to the differential localization of their cognate ligand.

Animals↗
PubMed2004

Homing of human autoreactive T cells into pancreatic tissue of NOD-scid mice.

AIMS/HYPOTHESIS: An important prerequisite for the initiation of pancreatic islet inflammation is the recruitment of pathogenic T cells. We investigated the in vivo migration patterns of human islet-reactive T cell clones after transfer into compromised hosts. METHODS: NOD-scid mice were injected with a mixture of human autoreactive T cells and antigen-presenting cells. Survival and migration of T cells was analysed by fluorescence-activated cell sorter and immunohistochemical analysis of various tissues. RESULTS: Autoreactive T cells and antigen-presenting cells survived at least 14 days in vivo and accumulated in spleen, pancreatic tissue and pancreas draining lymph nodes, but not elsewhere, as early as 4 days after transfer. This homing was dependent on co-injection of human antigen-presenting cells loaded with autoantigen. Finally, we found that this process is enhanced by streptozotocin treatment. Streptozotocin treatment did not affect the constitutive homing to pancreas draining lymph nodes. Histological analysis of pancreatic tissue sections showed some autoreactive T cells around the islets of Langerhans, comparable to early peri-islet insulitis. However, the majority of pancreas-infiltrating T cells accumulated around blood vessels in the exocrine pancreas. All T cell clones expressed the chemokine receptor CXCR3 that is associated with homing to insulitic lesions in men and mice. CONCLUSIONS/INTERPRETATION: Our study provides the first evidence of in vivo accumulation in pancreatic tissue of islet-reactive T cells derived from type 1 diabetic patients. The fact that such T cells do not penetrate islets is in line with the concept that additional factors may be required for the entry of T cells into inflamed islets to become diabetogenic.

Animals↗
PubMed1983

Lymphocyte migration across major histocompatibility barriers in splenectomized rats.

Localisation and migration patterns of iv injected radio-labelled thoracic duct (TD) lymphocytes were studied in particular with regard to passage through lymph nodes and re-entry into thoracic duct lymph. To avoid unwanted splenic sequestration of migrating lymphocytes presenting alloantigens to the recipient, only splenectomized recipients were used. Donor cells and recipients differed at the MHC (RT-1) locus, either in fully allogeneic (AO -- greater than BN and v.v.) or semi-allogeneic (AO -- greater than AO X BN and v.v.) combinations. In two of these combinations (BN -- greater than AO and AO X BN -- greater than AO) deficient output in TD lymph correlated with deficient localisation in lymph nodes and high amounts of radioactivity in the liver. In the other allogeneic combination (AO -- greater than BN), however, high TD output (i.e. when compared with the syngeneic combination BN -- greater than BN) correlated with good localisation in lymph nodes and low (control) levels of radioactivity in the liver. It was postulated that lymphocyte migration from blood to lymph under these circumstances can only be studied as an artifact secondary to whether or not migrating cells are removed from the circulation before they can reach and cross HEV's. These Allogeneic (or Altered) Lymphocytes Removing Tissues (by definition: Extranodular) may (conceptually) be comprised within one system: ALERT. It is our working hypothesis that the study of lymphocyte migration across (major) histocompatibility barriers is seriously impaired by the functioning of ALERT. It might be worthwhile to try and create conditions in which interference by this system is prevented, e.g. by using tolerant animals or bone-marrow chimeras.

Animals↗
PubMed1979

Immunochemical cross-reactions between type III group B Streptococcus and type 14 Streptococcus pneumoniae.

Serological cross-reactions between certain streptococci and some serotypes of Streptococcus pneumoniae have been reported. These studies detail the serological cross-reactivity observed between hot HCl-extracted group b streptococcus type III (GBS III) antigens and S. pneumoniae type 14 (Pn 14) polysaccharide. Similar electrophoretic migration patterns of GBS III and Pn 14 were observed when either type-specific BGS III antisera or pneumococcal omniserum was utilized to precipitate these antigens. Both the GBS III antigen and the Pn 14 polysaccharide migrated toward the cathode, whereas all other pneumococcal polysaccharides migrated toward the anode. No cross-reactions were observed between GBS III antisera and the 11 other types of pneumococcal polysaccharides. Lines of identity were observed between type-specific GBS III antisera and monospecific Pn 14 antiserum with either GBS III antigens or purified Pn 14 polysaccharide. The cross-reacting antigens of GBS III and Pn 14 appear to be identical by immunodiffusion and immunoelectrophoresis.

Antigens, Bacterial↗
PubMed1994

International migration in the Czech Republic and Slovakia and the outlook for East Central Europe.

This article "is devoted to the international migration issue in the Czech Republic and Slovakia (Czechoslovakia). Besides the contemporary trends, the international migration situation is briefly traced back to the communist era. The probable future scenario of international migration development--based especially on migration patterns that Western Europe has experienced--is also sketched, whilst mainly economic, social, political, demographic, psychological and geographical aspects are mentioned." Some consideration is also given to other countries in Eastern Europe. The different types of migration are analyzed, including illegal migration, labor migration, and refugees and asylum seekers.

Behavior↗
PubMedDate not supplied

O-acetylated sialic acids in gangliosides from pig spleen lymphocytes.

The sialic acid content of gangliosides from pig spleen lymphocytes was studied by thin-layer chromatography. N-glycolylneuraminic acid and N-acetylneuraminic acid were detected for the first time in this material as the major sialic acids. In addition, two other sialic acids, tentatively designated O-acetylated sialic acids, according to their RF values on cellulose plates, were also found. We have detected several gangliosides showing a retarded migration pattern in two dimensional thin-layer chromatography with an intermediate ammonia treatment. One of these gangliosides could be an O-acetylated derivative of the disialoganglioside GD3, since after de-O-acetyation it co-migrates with GD3. Another ganglioside co-migrated with GM2 before the alkaline treatment; however, after the treatment it was also retarded and co-migrates with GD3.

Acetylation↗
PubMed2005

Stable isotopes, beaks and predators: a new tool to study the trophic ecology of cephalopods, including giant and colossal squids.

Cephalopods play a key role in the marine environment but knowledge of their feeding habits is limited by lack of data. Here, we have developed a new tool to investigate their feeding ecology by combining the use of their predators as biological samplers together with measurements of the stable isotopic signature of their beaks. Cephalopod beaks are chitinous hard structures that resist digestion and the stable isotope ratios of carbon (delta13C) and nitrogen (delta15N) are indicators of the foraging areas and trophic levels of consumers, respectively. First, a comparison of delta13C and delta15N values of different tissues from the same individuals showed that beaks were slightly enriched in 13C but highly impoverished in 15N compared with lipid-free muscle tissues. Second, beaks from the same species showed a progressive increase in their delta15N values with increasing size, which is in agreement with a dietary shift from lower to higher trophic levels during cephalopod growth. In the same way, there was an increase in the delta15N signature of various parts of the same lower beaks in the order rostrum, lateral walls and wings, which reflects the progressive growth and chitinization of the beaks in parallel with dietary changes. Third, we investigated the trophic structure of a cephalopod community for the first time. Values of delta15N indicate that cephalopods living in slope waters of the subantarctic Kerguelen Islands (n=18 species) encompass almost three distinct trophic levels, with a continuum of two levels between crustacean- and fish-eaters and a distinct higher trophic level occupied by the colossal squid Mesonychoteuthis hamiltoni. delta13C values demonstrated that cephalopods grow in three different marine ecosystems, with 16 species living and developing in Kerguelen waters and two species migrating from either Antarctica (Slosarczykovia circumantarctica) or the subtropics (the giant squid Architeuthis dux). The stable isotopic signature of beaks accumulated in predators' stomachs therefore revealed new trophic relationships and migration patterns and is a powerful tool to investigate the role of the poorly known cephalopods in the marine environment.

Animal Migration↗
PubMed1983

Assessment of in vivo natural antitumor resistance and lymphocyte. Migration in mice: comparison of 125I-iododeoxyuridine with 111indium-oxine and 51chromium as cell labels.

Clearance of IV-injected tumor cells has been correlated with levels of natural killer (NK) cell activity in recipient animals. Studies of in vivo tumor cell clearance strongly suggest a relationship between levels of NK cell activity and antitumor or antimetastatic effector function. This study outlines the applicability of three radiolabels, [125I]iododeoxyuridine, ( [125I]dUrd), indium-111-oxine chelate ( [111In]Ox), and chromium-51 (51Cr), to studies of tumor cell clearance in vivo. The suitability of these labels for analysis of the in vivo migration patterns of normal lymphocytes or thymus-derived T cells cultivated in vitro (CTC) is also discussed. The results indicate that [111In]Ox and 51Cr compare favorably with the more widely used [125]dUrd as radiolabels for the assessment of IV-injected tumor cell clearance from the lungs of mice. The rates of clearance of both [111In]Ox and 51Cr, like that for [125I]dUrd, correlate closely with levels of NK-cell activity of the host. Further studies with [111In]Ox reveal that treatment of recipients with anti-asialo GM1 serum, a regimen known to suppress NK-cell activity, demonstrates the appropriate reduction in isotope clearance from the lungs after NK suppression. However, clearance data obtained by monitoring levels of radioactivity in the liver after IV injection must be viewed cautiously, since the same cells labeled with [111In]Ox and [125I]dUrd had a different pattern of clearance from the liver. The same inconsistencies in clearance were observed when [111In]Ox and [125I]dUrd were injected intrafootpad (i.f.p.). Similar effects were observed when [111In]Ox or 51Cr was applied to studies of CTC migration. Levels of [111In]Ox and 51Cr remained high in the liver after IV injection, while [125I]dUrd was rapidly cleared. Normal spleen or thymic lymphocytes exhibited the expected homing to the spleen after labeling with [111In]Ox, indicating a suitability of this label for migration studies, except possibly in the liver. These results with CTC and normal lymphocytes should be considered during the formulation of immunotherapy protocols based on cell migration data, since the choice of radiolabel can result in widely divergent levels of radioactivity accumulated in some organs, and may not provide an accurate representation of the presence of viable, intact, or functional cells.

Animals↗
PubMed2004

Molecular study of the 3 beta-hydroxysteroid dehydrogenase gene type II in patients with hypospadias.

To determine whether some patients with idiopathic hypospadias have HSD3B2 mutations, we genotyped this locus in 90 patients with hypospadias (age, 6.0 +/- 0.4 yr) and 101 healthy fertile male controls. We measured basal plasma renin activity and performed an ACTH test for determination of 17-OH-pregnenolone, 17-OH-progesterone, cortisol, dehydroepiandrosterone sulfate, and androstenedione and an human chorionic gonadotropin test for determination of androstenedione, testosterone, and dihydrotestosterone. We did not observe a clear steroidogenic pattern suggestive of 3 beta-HSD deficiency in any patient. DNA was extracted from peripheral lymphocytes; and exons 1, 2, 3, and 4 were amplified by PCR and analyzed by denaturing gradient gel electrophoresis. An abnormal electrophoretic migration pattern of exon 4 was observed in five patients. Two patients had missense heterozygous mutations (S213T and S284R). In another three patients, we observed heterozygous nucleotide variants in exon 4 that did not produce a change in amino acids (A238, T259, T320). In vitro enzymatic activity was diminished by 40% and 32% in the S213T and S284R heterozygous mutations, respectively. One control exhibited a heterozygous mutation in exon 3 (V78I), which did not alter in vitro enzyme activity. In addition, we observed possible polymorphisms in intron 1 in four patients and one control. We conclude that subtle molecular abnormalities in the HSD3B2 gene may be observed in some patients with apparent idiopathic hypospadias but that this finding is uncommon.

3-Hydroxysteroid Dehydrogenases↗
PubMed2001

Detection of T-cell receptor-gamma gene rearrangement in lymphoproliferative disorders by temperature gradient gel electrophoresis.

OBJECTIVE: Polymerase chain reaction amplification of DNA for T-cell receptor (TCR) gene rearrangement analysis is helpful in the evaluation of T-cell lymphoproliferative disorders. Detection of polymerase chain reaction products is limited by the poor resolution of bands analyzed by agarose or polyacrylamide gel electrophoresis. To improve the detection of a clonal T-cell population, we used temperature gradient gel electrophoresis (TGGE) as an alternative method for analysis of TCR gene rearrangement. DESIGN: One hundred eighteen archival DNA samples were randomly selected based on previous Southern blot analysis results. Samples included 58 T-cell neoplasms with positivity for TCR beta gene rearrangement, 22 cases of reactive hyperplasia with germline pattern for both TCR beta and J(H), and 38 patients with B-cell lymphoma. MOLT-16, a T-cell lymphoblastic cell line, was used for the sensitivity assay. Polymerase chain reaction was performed using GC-clamped multiplex primers to amplify the TCR gamma locus and was analyzed by TGGE. The range of temperature gradients was empirically determined for optimal resolution of bands. RESULTS: The sensitivity of TGGE was 0.1% when DNA from the MOLT-16 cell line was serially diluted with DNA from reactive lymphoid tissue. Fifty-four (93%) of 58 T-cell neoplasms with TCR beta gene rearrangements showed rearrangement patterns by TCR gamma TGGE, and only 1 of 60 samples (reactive or B-cell lymphomas) showed evidence of gene rearrangement by TGGE. Patients with T-cell neoplasm and involvement of multiple sites showed an identical migration pattern by TGGE analysis. CONCLUSION: We demonstrate that TGGE is an effective method for analysis of TCR gene rearrangement in the evaluation of nodal and extranodal lymphoid lesions.

Ascitic Fluid↗
PubMed1988

Topography and behavior of Sertoli cells in sparse culture during the transitional remodeling phase.

We report observations on the behavior of Sertoli cells in sparse culture during the period from the time of plating to the time of initial confluence (the transitional remodeling phase). Changes in shape, structure, and polarity of cells, as well as changes in migration patterns and cell-cell association patterns, have been followed during the transitional remodeling phase with the aid of topographical markers. These markers are based upon differences between ultrastructural features of the basolateral and apicolateral surfaces. The basolateral surface is characterized by plasmalemmal blebs, whereas the apicolateral surface is characterized by filopodial extensions. Structural differences observed in situ remain evident in Sertoli cells isolated by sequential enzymatic treatments that are described. Another marker is provided by laminin-binding sites, which are detected exclusively on the blebbed, basolateral surfaces of freshly prepared Sertoli cell aggregates. The orientation described is sustained during the initial radial migration of Sertoli cells explanted on uncoated glass coverslips. Under these conditions, blebs are detected only on the dorsal surfaces, and filopodial extensions are evident only on the ventral surfaces. In contrast, Sertoli cells sparsely plated on a reconstituted basement membrane (air-dried Matrigel) migrate rapidly, display an extraordinary capacity to form elaborate cytoplasmic extensions for cell-cell and cell-substratum contacts, and readily retract blebs and filopodial extensions. These cells do not form mosaic borders, whereas cells plated on uncoated glass do form a monolayer with mosaic-like borders. Cells sparsely seeded on gelated Matrigel migrate preferentially at gaps between adjacent cell explants, and develop a compact cell-cell association pattern. These cells display few, if any, cytoplasmic extensions. We compare the behavior of Sertoli cells sparsely plated on Matrigel with the behavior of Sertoli cells in situ during different stages of development.

Actins↗
PubMed1999

In vivo migration of lymphocytes in chronically rejecting rat kidney allografts.

Histological analyses have identified lymphocytes and macrophages as the predominant leukocyte populations that infiltrate organs undergoing chronic rejection. In order to define the time frame of this infiltration, we investigated the in vivo migration pattern of lymphocytes in a well-established rat model of chronic kidney allograft rejection. F344 kidneys were orthotopically transplanted into bilaterally nephrectomized Lewis rats. Recipients were treated with cyclosporin A (1.5 mg/kg/per day) for the first 10 days. After anti-CD18 or vehicle pretreatment, peripheral blood lymphocytes obtained from naive Lewis rats and labeled with 3H-uridine were injected into transplanted rats 12 and 16 weeks after transplantation. Organs were harvested 4, 8, and 12 h thereafter. After 12 weeks, proteinuria developed, accompanied by all signs of chronic rejection including glomerular sclerosis. Labeled lymphocytes rapidly infiltrated grafted kidneys 4 h after injection. Even more lymphocytes had accumulated in the grafts 12 h after injection. After 16 weeks, few lymphocytes had emigrated into the graft at 4 h, while infiltration was most pronounced by 12 h. Pretreatment with anti-CD18 inhibited the influx of lymphocytes. There was no difference between the patterns of lymphocytes derived from naive and transplanted rats. Our results emphasize the importance of endothelial cells in chronically rejecting kidneys for the control of leukocyte influx. Beta2-integrins may play a central role in determining the transendothelial migration during this process.

Animals↗
PubMed2006

Evolutionary consequences of dispersal ability in cactus-feeding insects.

Although gene flow is an important determinant of evolutionary change, the role of ecological factors such as specialization in determining migration and gene flow has rarely been explored empirically. To examine the consequences of dispersal ability and habitat patchiness on gene flow, migration rates were compared in three cactophagous longhorn beetles using coalescent analyses of mtDNA sequences. Analyses of covariance were used to identify the roles of dispersal ability and habitat distribution in determining migration patterns. Dispersal ability was a highly significant predictor of gene flow (p< 0.001), and was more important than any other factor. These findings predict that dispersal ability may be an import factor shaping both microevolutionary and macroevolutionary patterns; this prediction is borne out by comparisons of species diversity in cactus-feeding groups.

Analysis of Variance↗