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PubMed1994

Demographic influences on the number of children at school entry ages, with examples from three states.

"This paper analyzes the effects of changes in fertility, mortality, and net migration patterns on the growth of school entry-age populations in three states (Florida, South Carolina, and West Virginia) over the period 1950-1990. Fertility changes have had the largest influence on growth of these young populations, as common sense suggests. Changing migration patterns have been quite important, however, in explaining intertemporal and interspatial variations in growth rates."

Age Distribution↗
PubMed1991

Interleukin-2 stimulated T cell receptor V gamma 3 positive thymocytes do not migrate to the skin.

T cell receptor (TcR) V gamma 3+ thymocytes, which only develop in the fetal thymus, migrate to the skin. IL-2 stimulation of fetal day 18 murine thymocytes results in a cell population of which 45% of the cells express the TcR V gamma 3. In this study, we describe that those IL-2 cultured TcR V gamma 3+ thymocytes have the killing capacity of lymphokine activated killer cells: NK-susceptible as well as NK-resistant tumor cell lines were killed in an MHC-unrestricted manner. Because of these findings, IL-2-expanded TcR V gamma 3+ thymocytes could have a potential use in adoptive immunotherapy for skin-located tumors. Therefore, we analyzed the migration pattern of IL-2-cultured TcR V gamma 3+ thymocytes upon i.v. injection. We describe their initial entrapment in the lungs and subsequent accumulation in the liver. Localization in the skin was practically absent, and did not differ from that of IL-2 cultured adult thymocytes (mainly TcR alpha beta +). The migration pattern was identical in adult and newborn normal mice, and in adult nude mice. Analysis of the expression of asialo-GM1 revealed that it increased strongly after IL-2 culture. The relevance of this change in asialo-GM1 expression with reference to the migration upon i.v. injection is discussed. This study indicates that an improved understanding of the determinants of in vivo localization of IL-2 cultured cells may lead to improved strategies for adoptive immunotherapy of cancer.

Age Factors↗
PubMed1987

Residential moves by elderly persons to U.S. central cities, suburbs, and rural areas.

The 1975-1980 migration stream and net migration patterns of persons younger than 65 and 65 + were examined using data from the 1980 U.S. Census. Central cities and suburbs of metropolitan areas (SMSAs) and nonmetropolitan areas (NonSMSAs) were distinguished as origins and destinations. Most elderly movers relocated within a fairly limited geographic context and revealed strong preferences for metropolitan living. Suburban locations were more favored than central city locations. Net migration findings may provide misleading interpretations of older movers' locational choices. The migration patterns of the 65 + population were similar to those of the 45- to 64-year-old population but differed from those of the more youthful U.S. populations. These findings highlight migration streams of elderly movers who likely have experienced changed in their life styles or personal resources.

Adolescent↗
PubMed1998

Explaining the recent migration trends of the Tokyo metropolitan area.

Recent migration trends affecting the Tokyo metropolitan area (TMA) in Japan are analyzed. The focus is on the factors affecting the change in migration patterns which resulted in a net outflow of migrants from the area in 1994, the first time this has occurred. "The results from a set of time-series analyses lead the authors to conclude that, as far as the study period (1979-92) as a whole is concerned, the changing migration pattern of the TMA arose from factors closely related to Tokyo's transformation into a world city (specifically in terms of industrial restructuring and changes in residential land prices) and from cycles of economic boom and bust. However, it was found that the change to world city was more important than the economic cycle. Such findings suggest that the Japanese migration system experienced structural change during the 1980s and entered a new phase in the 1990s."

Agriculture↗
PubMed1998

Serum high molecular weight form of insulin-like growth factor II from patients with non-islet cell tumor hypoglycemia is O-glycosylated.

Non-islet cell tumor hypoglycemia (NICTH) is one of major causes of fasting hypoglycemia. In some patients with NICTH, insulin-like growth factor II (IGF-II) produced by and secreted from the tumors is thought to be a hypoglycemic agent. In patients with NICTH, the major form of IGF-II is high molecular weight form of IGF-II, designated as big IGF-II. The generation of big IGF-II in the NICTH syndrome is unclear. It has been reported that in the patients with NICTH big IGF-II lacks normal E-domain O-linked glycosylation, suggesting that the patient's big IGF-II might be generated by abnormal processing of pro-IGF-II. However, we have found that the apparent size of big IGF-II varies in sera from the patients with NICTH, and that there is a possibility that slower migration pattern of IGF-II might be because of a different size of sugar moiety attached to pro-IGF-II. In the present study using the sera from 10 patients with NICTH, we investigated the effect of O-glycosidase digestion on migration of IGF-II and analyzed the results by Western immunoblot. By Western immunoblot analysis the big IGF-II was reduced in size to 9.5 kDa in the enzyme-treated sera of the 10 patients with NICTH. The migration pattern is similar to that observed in sera of normal subjects after O-glycosidase digestion. These data indicate that big IGF-II from patients with NICTH is O-glycosylated, and the sizes of the sugar moiety are larger than those from normal subjects suggesting abnormal glycosylation in NICTH.

Adult↗
PubMed1989

Adoptive immunity to Mycobacterium bovis strain bacillus Calmette-Guérin by long-term cultured T-cell line in nude mice.

Tuberculin-active peptide-reactive T-cell lines were established from the popliteal lymph node of BALB/cA mice immunized with heat-killed Mycobacterium tuberculosis to investigate the cellular mechanisms in the protective immunity of tuberculosis. These T-cell lines, consisting mainly of L3T4 surface antigen-positive cells, were transferred intravenously into nude mice infected with M. bovis strain bacillus Calmette-Guérin (BCG). Four or 6 weeks after transfer, footpad swelling and hepatic granuloma formation were observed and viable counts in the liver were decreased. Reduction of viable counts in the liver was obviously preceded by the hepatic granuloma formation. An effect of Lyt-2+ T cells which might be included in the inoculum could be ruled out by the experiment using T-cell lines pretreated with anti-Lyt-2 monoclonal antibody and complement. These results indicated that T cells required for protective immunity in these experiments belong to the L3T4-positive TDTH subset. However, their protective activity was inferior to that of freshly prepared immune lymph node T cells. From the observation of migration patterns of 51Cr-labelled T cells in BCG-infected nude mice, a relatively high proportion of freshly isolated T cells, but only a small part of T-cell line, deposited in the spleen of infected nude mice. This difference in migration pattern of freshly isolated and cultured T cells could be one of the reasons for the less in vivo anti-bacterial activity of the latter.

Animals↗
PubMed1998

CD4+ T cells from 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis rodents migrate to the recipient's colon upon transfer; down-regulation by CD8+ T cells.

CD4+ T cells play an important role in the aetiology of inflammatory bowel disease (IBD), but it is not clear which factor(s) cause activation of these cells. The aim of this study was to examine the effects of adoptive transfer of splenic (CD4+) T cells from TNBS/ethanol-sensitized donor rats to naive recipients and the migration pattern of transferred T cells. For the transfer experiments, colitis was induced in rats by colonic administration of TNBS/ethanol. Seventeen days later, either total splenic T cells or CD4+, or CD8+ T cells were transferred to naive recipients. At days 1, 2 and 3 after transfer, the recipients were killed and the migration pattern of the transferred T cells was studied, as well as inflammatory cells in several organs, including the colon. To determine cytokine profiles of the T cells, colitis was induced in mice. Therefore, different combinations of 2,4-dinitrobenzene sulfonic acid (DNBS) in ethanol or saline, or ethanol alone were intrarectally administered. At day 9 after induction of colitis, mice were killed and cytokine profiles in the colon were studied by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry. The results show that CD4+ T cells from donor rats with TNBS/ethanol-induced colitis migrate in particular to the colon upon transfer to naive recipients, and that this process is down-regulated by CD8+ T cells. This migration is probably caused by T cell recognition of the colonic bacterial flora and initiates an inflammatory reaction in the recipient's colon, characterized by an increase of the recipient's own T cells, macrophages, and neutrophils. In the mice experiments we showed that a second administration of DNBS/ethanol or ethanol alone, which presumably causes bacterial translocation, results in increased numbers of T cells into the colon, accompanied by an increase in Th1 cytokines. These data suggest that Th1 cells recognize the colonic bacterial flora.

Adoptive Transfer↗
PubMed1996

Low incidence of the stimulatory G protein alpha-subunit mutations in autonomously functioning thyroid adenomas in Japan.

Point mutations of the alpha-subunit of the stimulatory G protein (Gs alpha) (termed gsp) and the TSH receptor, leading to constitutive elevation of intracellular cAMP contents, have recently been described in autonomously functioning thyroid adenomas. Since we have recently found a clear difference in the incidence of such gain-of-function mutations of the TSH receptor between Japan and Europe, the present study was designed to evaluate the incidence of gsp mutations in a series of autonomously functioning thyroid adenomas in a Japanese population. Thirty-eight autonomously functioning thyroid adenomas were employed in the present study. Genomic DNA was extracted from archival formalin-fixed, paraffin-embedded tissue specimens. Exons 8 and 9 of the Gs alpha gene were examined for activating mutations at codons 201 and 227 by single-strand conformation polymorphism (SSCP) and nucleotide sequencing. Both exons 8 and 9 were successfully amplified in 28 of 38 samples by polymerase chain reaction. Of these only one sample for exon 9 displayed a distinct migration pattern in SSCP analysis, in which a point mutation of a G to C transversion was identified by nucleotide sequencing, resulting in substitution of His (CAC) for Gln (CAG) at codon 227. The wild-type sequence of exon 9 in 10 randomly selected samples with an identical migration pattern in SSCP analysis suggests that underestimation of the incidence of gsp mutations is unlikely in our work. In conclusion, the present data, together with our previous data on the TSH receptor, suggest that oncogenic mutations of the Gs alpha as well as the TSH receptor do not seem to play a major role in tumorigenesis of autonomously functioning thyroid adenomas in Japan.

Adenoma↗
PubMed1991

Electrophoretic karyotyping and chromosomal gene mapping of Chlorella.

Molecular karyotypes for six strains of four Chlorella species were obtained by using an alternating-field gel electrophoresis system which employs contour-clamped homogenous electric fields (CHEF). The number and migration pattern of the chromosomal DNA molecules varied greatly from strain to strain: for example, nine separated chromosomes of C. ellipsoidea C87 ranged from 2.5 to 6.5 megabase pairs (mbp) in size, whereas 16 chromosomes of C. vulgaris C169 were from 980 kilobase pairs (kbp) to 4.0 mbp. Depending on the chromosome migration patterns, the six strains were classified into two major chromosome-length polymorphism groups. Using hybridization techniques, the genes for alpha-tublin, chlorophyll-a, b-binding proteins, ribosomal RNAs, and the small subunit of ribulose-1, 5-bisphosphate carboxylase/oxygenase (RuBisCO) were mapped on the separated chromosomes of C. vulgaris C169. Since Chlorella chromosomes are small enough to separate and isolate individually by CHEF gel electrophoresis under ordinary conditions, they should serve as excellent materials to study the fundamental molecular structure of plant-type chromosomes.

Chlorella↗
PubMed2001

The alkaline single-cell gel electrophoresis/comet assay: a way to study DNA repair in radicle cells of germinating Vicia faba.

Dry seeds are known to accumulate DNA damage with time of storage. Repair of DNA lesions during germination of Vicia faba seeds was followed in the radicles using the alkaline single-cell gel electrophoresis/comet assay. In this assay nuclei were liberated, mixed with agarose and spread out over a microscope slide. After lysis of the nuclear membrane and unwinding of the DNA duplex, DNA was stretched during electrophoresis, giving a comet-like migration pattern. The more DNA was damaged, the higher its mobility. DNA repair took place rapidly the first hours of imbibition and more slowly until ca 33 h after onset of germination. A small amount of heavily damaged cells remained present. Labelling with BrdU provided the possibility to localize repair patches and replicated sites in the comet migration pattern. At 15 h of germination, incorporation of BrdU in radicle DNA was situated at random over the entire comet. At 33 h, DNA repair was more or less accomplished and BrdU was mainly localized in the 'heads' of most comets.

Bromodeoxyuridine↗
PubMed1986

Genetic stability in calves of a single strain of bluetongue virus.

Newborn calves were inoculated IV with highly plaque-purified bluetongue virus (BTV), serotype 10. The electrophoretic migration patterns of RNA segments and proteins of viruses isolated from calves at intervals after inoculation were compared. In addition, sera collected from calves at intervals after inoculation were compared for their abilities to neutralize several virus isolates from the same calf. Viremia persisted in calves for up to 56 days. Differences were not detected in the electrophoretic migration pattern of RNA segments or proteins of any of the BTV isolates. All calves produced high titers of neutralizing antibody to the original BTV inoculum by 28 days after inoculation, and significant (greater than or equal to 4-fold) differences were not detected in the neutralizing titers of sera to viruses collected at intervals after inoculation. The plaque-purified strain of BTV appeared to be stable genetically in infected calves, and failure to demonstrate antigenic variation among isolates indicated that antigenic shift was not the mechanism that allowed viremia to persist in BTV-infected calves.

Animals↗
PubMed1992

Tissue-specific migration pathways by phenotypically distinct subpopulations of memory T cells.

A proportion of T cells recirculate in a tissue-selective manner. Recent studies which showed that the skin-tropic subset of T cells was of memory/activated type, led us to examine whether the preferential homing of T cells to the gut also involved memory T cells, and if so whether these memory T cells were phenotypically distinct from other memory T cells. Lymphocytes migrating through the gut and the skin of sheep was collected by cannulating the lymphatic ducts draining these tissues. Both naive and memory T cells were found to recirculate through the gut, although only memory T cells migrated through the skin. However, when T cells from the gut were labeled with fluorescein isothiocyanate and assessed for their migration back to the gut, it was the memory population which showed a tropism for the gut. Gut-tropic memory T cells migrated poorly through the skin, indicating that these cells were distinct from skin-tropic memory T cells. This was confirmed by phenotypic analysis. Gut memory T cells expressed very low levels of the alpha 6 and beta 1 integrins, in contrast to skin memory T cells which expressed high levels. There was no evidence for heterogeneity within the naive T cell population, which migrated preferentially to lymph nodes. This migration pattern could be explained in part by the high expression of the L-selectin (lymph node homing receptor, LAM-1) on naive T cells, in contrast to memory T cells from gut or skin which were mostly L-selectin negative. These results in sheep indicate that subsets of alpha/beta memory T cells show tissue-selective migration patterns, which probably develop in a particular environment following encounter with antigen.

Animals↗
PubMed2000

Population structure of the rural communities on the island of Krk (Croatia): A comparison of genetic, cultural, and geographic data.

The population structure of seven rural communities from the island of Krk (Croatia) was studied on the basis of its genetic constitution and genetic structure, and different sets of biological (genetic), biocultural (migration), cultural (linguistic), and geographic data. Genetic constitution was estimated from the allelic frequencies of nine tetranucleotide STR loci, three HLA class I loci, five HLA class II loci, and five red blood cell enzyme and serum protein loci. Genetic structure was based on coefficients of genetic diversity G(ST) and genetic kinship R(ST). Population structure was assessed by the structure of mutual relationships among biological, biocultural, cultural, and geographic matrices through Mantel's test, or by relationships among biological, biocultural, cultural measures of distance and/or similarity, and geographic distance with regression analysis of the "isolation by distance" model. One group of genetic markers (red blood enzymes, serum proteins, and HLA polymorphisms) reflects heterogeneity of the rural communities (a reflection of important historical processes and migration patterns), and a second group of genetic markers (STR polymorphisms) reflects the currently observed genetic homogeneity of the rural population. The positive correlations between the matrices of genetic (HLA) and linguistic distances indicate their possible co-evolution under conditions of genetic isolation (low gene flow). Furthermore, the negative correlations between the matrices of genetic (STR) distances and the migration kinship of the second and the third cohort indicate temporal coincidence between genetic constitution and structure assessed from STRs and migration patterns in the period between 1892 and 1940. Finally, the positive correlations between the matrices of genetic (STR) and geographic distances indicate isolation by distance. Am. J. Hum. Biol. 12:509-525, 2000. Copyright 2000 Wiley-Liss, Inc.

Journal Article↗
PubMed1994

Rate and pattern of migration of lineally-related olfactory bulb interneurons generated postnatally in the subventricular zone of the rat.

A spatially discrete region of the anterior part of the postnatal telencephalic subventricular zone, referred to as the SVZa generates vast numbers of lineally-related neurons destined for the olfactory bulb (Luskin, 1993). The cells originating in the SVZa migrate to the olfactory bulb along a highly restricted pathway which is in a direction orthogonal to the orientation of radial glial fibers. In this study we analysed the number, distribution, orientation and rate of migration of SVZa-derived cells as they approach the olfactory bulb. In order to track the SVZa-derived cells, a retroviral lineage tracer, encoding the reporter gene E. coli beta-galactosidase (lacZ) was injected precisely into the rat SVZa at postnatal day 1 (P1). The lacZ-positive cells were visualized 1, 2 and 3 days later by X-Gal histochemistry in cryostat sections. As the number of SVZa-derived cells in the pathway increased with survival time, their distribution changed systematically. The distribution pattern of lacZ-positive cells by 2 and 3 days postinjection suggested that some of the progeny of infected progenitor cells were undergoing neurogenesis as they proceeded to the olfactory bulb; a large percentage of the lacZ-positive cells were substantially displaced from the SVZa injection site. To investigate whether lacZ-positive cells migrate in a directed fashion, their orientation preference was scored. For the majority of lacZ-positive cells (> 94%), their leading process was directed toward the olfactory bulb, possibly reflecting a response to migratory cues present along the pathway. The estimated average rate of cell migration to the olfactory bulb was 23 mu m/h, which is approximately twice the speed of radially directed neuronal migration from the telencephalic ventricular zone to the cortical plate (O'Rourke et al., 1992). Collectively, these results suggest that SVZa-derived interneurons en route to the olfactory bulb may employ a novel mode of tangential migration.

Animals↗
PubMed1988

The molecular heterogeneity of nonspecific cross-reacting antigen synthesized by tumor cells and granulocytes.

The molecular heterogeneity of nonspecific cross-reacting antigen (NCA) was examined. Metabolically-labeled glycoproteins were precipitated from cell lysates of human tumor cell lines and of normal peripheral granulocytes with antibodies specific for NCA, and analyzed by SDS-PAGE. NCA components synthesized by three tumor cell lines, QGP-1 (pancreas), HLC-1 (lung) and CAOV-2 (ovary) showed slightly different migration patterns on SDS-PAGE, but the molecular weights of their unglycosylated peptides synthesized in the presence of tunicamycin were all found to be 35K. On the other hand, two molecular species of NCA were identified in normal granulocytes: an 80K mature form derived from a 69K precursor peptide and a 58K mature form from a 41K precursor peptide. Upon SDS-PAGE, the migration pattern of the unglycosylated NCA peptides from tumor cells was affected by the presence of 2-mercaptoethanol, while that of the peptides of granulocytes was not. All the NCAs identified in this study possessed antigenic determinants common to carcinoembryonic antigen as well as those unique to NCA. These results suggest that the molecular heterogeneity of NCA observed thus far resulted from diverse glycosylation of the three fundamental molecular forms of unglycosylated peptides: one with a molecular weight of 35K produced by tumor cells and two with molecular weights of 69K and 41K produced by granulocytes.

Antigens↗
PubMed2001

Proteolytic action of Bothrops jararaca venom upon its own constituents.

Many of the components of Bothrops jararaca venom are proteolytic enzymes. In the present work, we investigated the proteolytic action of B. jararaca venom upon its own constituents. Crude venom was reconstituted and incubated at pH 5.0 or 8.5 for up to 48h at room temperature. Aliquots taken at 0, 24 and 48h of incubation were then tested for proteolytic activity and several biological activities, as well as electrophoretic migration pattern and antibody recognition. Rate of hydrolysis of azocasein by venom samples was not changed by the incubation, but hemagglutinating activity decreased by 93% after 24h of incubation at pH 8.5, with no detectable changes at pH 5.0. Incubation of venom samples caused a progressive increase in phospholipase A(2) and procoagulant activities that was more evident in samples incubated at pH 5.0. The electrophoretic migration pattern showed no significant change for venom samples incubated at pH 5.0, whereas in samples incubated at pH 8.5 bands in the region between 66 and 45kDa gradually disappeared. The addition of a mixture of protease inhibitors (EDTA, PMSF, PPACK and benzamidine) effectively protected against venom degradation at pH 8.5. The cocktail of inhibitors also reduced the changes in phospholipase A(2) activity found in venom samples incubated at pH 5.0. Recognition of venom samples by polyclonal antibodies raised against crude venom was progressively lost during incubation at both pH 5.0 and 8.5; again the addition of protease inhibitors protected against loss of antibody recognition. We conclude that prolonged manipulation of B. jararaca venom at an acidic or alkaline pH can produce significant changes in its biological properties.

Animals↗
PubMed1999

Expression of doublecortin correlates with neuronal migration and pattern formation in diverse regions of the developing chick brain.

The development of functional layers in the brain involves spatially and temporally regulated gene expression. Through cDNA library screening, we have identified genes that are expressed in a neural-specific manner during brain development. Sequencing and expression data indicate that one of the clones, 18C15, is the chick homologue of doublecortin, a human X-linked gene found to be mutated in subcortical laminar heterotopia (double cortex syndrome) and lissencephaly. The 18C15 mRNA contains multiple motifs that are known to regulate mRNA stability in response to inductive signals, and these motifs are conserved between the chick and human sequences. Doublecortin is found to be expressed at peak levels during early development of the cerebellum and forebrain, and is expressed in other regions including the tectum, spinal cord, and dorsal root ganglia. This study demonstrates both spatial and temporal regulation of doublecortin expression in the chick, which is associated with early events in brain development, including neuronal migration.

3' Untranslated Regions↗