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PubMed1981

The surface character of separated prostatic cells and cultured fibroblasts of prostatic tissue as determined by concanavalin-A hemadsorption.

Con-A-coated human type O red blood cells (indicator RBC) were used for ConA reactivity assay of separated epithelial cells and cultured fibroblasts of human prostatic tissue. The epithelial cells of carcinoma showed higher reactivity than those of normal tissue or hyperplastic tissue. Although both cultured fibroblasts of PC and BPH are considered to be non-malignant, it is clearly demonstrated that the PC fibroblasts have a malignant surface character in terms of ConA reactivity, whereas the BPH fibroblasts have a quite low ConA reactivity. ConA-mediated HAD appeared to be a useful tool to distinguish malignant epithelial cells of human prostate from non-malignant ones. It still remains unknown whether the alteration of PC fibroblasts is the cause or the result of carcinogenic transformation of prostatic tissue.

Cell Line↗
PubMed1990

Distinct character in hydrophobicity of amino acid compositions of mitochondrial proteins.

A compact mitochondrial gene contains all essential information about the synthesis of mitochondrial proteins which play their roles in a small compartment of the mitochondrium. Almost no noncoding regions have been found through the gene, but a necessary set of tRNAs for the 20 amino acids is provided for biosynthesis, some of them coding different amino acids from those in a usual cell. Since the gene is so compact that the produced proteins would have some characteristic aspects for the mitochondrium, amino acid compositions of mitochondrial proteins (mt-proteins) were examined in the 20-dimensional composition space. The results show that compositions of proteins translated from the mitochondrial genes have a distinct character having more hydrophobic content than others, which is illustrated by a clustered distribution in the multidimensional composition space. The cluster is located at the tail edge of the global distribution pattern of a Gaussian shape for other various kinds of proteins in the space. The mt-proteins are rich in hydrophobic amino acids as is a membrane protein, but are different from other membrane proteins in a lesser content of Val. A good correlation found between the base and amino acid compositions for the mitochondria was examined in comparison to those of organisms such as thermophilic bacterium having an extreme G-C-rich base composition.

Amino Acids↗
PubMed1993

N-linked sugar chain structure of recombinant human lymphotoxin produced by CHO cells: the functional role of carbohydrate as to its lectin-like character and clearance velocity.

Recombinant human lymphotoxin (rhLT) produced by CHO cells transfected with human LT genomic DNA was purified to homogeneity, but approximately 5% of the molecules were devoid of the last two amino terminal residues. A peptide N-glycosylated at Asn62 (Tr-45) and one partially O-glycosylated at Thr7 (Tr-14) on cleavage with trypsin were separated by reverse phase HPLC. The N-linked sugar chains of Tr-45 were released quantitatively as oligosaccharides on hydrazinolysis (100 degrees C, 8 h), followed by N-acetylation. After being reduced with either NaB3H4 or NaB2H4, their structures were determined by a combination of serial lectin affinity chromatography, exoglycosidase digestion, and methylation analysis: 82.7% of the sugar chains occur as biantennary complex-type sugar chains, the remainder being C-2 and C-2,4/C-2,6 branched triantennary, and C-2,4 and C-2,6 branched tetraantennary complex-type sugar chains with a fucosylated mannose core. Their sialic acid residues occur only as the Neu5Ac alpha 2-->3Gal group. The clearance velocity from the bloodstream dramatically increased with desialylation, and rhLT tends to have accumulated in the kidney, indicating that there may exist other mechanisms for clearance from the circulation besides the galactose-binding protein in hepatocytes and the filtration system of the kidney. Desialylated rhLT showed a lectin-like binding character to uromodulin similar to that of tumor necrosis factor, although intact rhLT did not. The interaction between desialylated rhLT and uromodulin was inhibited by N,N'-diacetylchitobiose and [Man alpha 1-->6(Man alpha 1-->3)Man alpha 1-->6](Man alpha 1-->2Man alpha 1-->3)Man beta 1-->4GlcNAc beta 1-->4GlcNAc-->Asn. These results indicate that the lectin-like domain of rhLT is exposed on its desialylation.

Amino Acid Sequence↗
PubMed1998

Hepatocytes deficient in CCAAT/enhancer binding protein alpha (C/EBP alpha) exhibit both hepatocyte and biliary epithelial cell character.

To further elucidate the role of CCAAT/Enhancer Binding Protein alpha (C/EBP alpha) in hepatocyte differentiation, we investigated fetal and newborn C/EBP alpha-deficient (C/EBP alpha -/-) mice using confocal microscopy and markers specific for hepatocyte (AFP) and biliary epithelial cell (A6) differentiation. Histologically, in fetal liver of C/EBP alpha -/- mice, pseudoglandular structures appeared starting at 16.5 days of gestation. In newborn livers, the diameters of these structures greatly increased. They were randomly distributed between portal and central veins and interfered with the establishment of normal hepatic plates. However, the portal bile ducts developed normally. The pseudoglandular structures were lined with small hepatocytes with round nuclei and were positive for both AFP and A6 antigens. These data show that C/EBP alpha -/- hepatocytes exhibit biliary epithelial cell characters and suggest an involvement of C/EBP alpha in the control of the switch in the differentiation of bi-potential hepatoblasts along the hepatocyte lineage.

Animals↗
PubMedDate not supplied

Kanji lexicality effect in partial repetition priming: the relationship between Kanji word and Kanji character processing.

Two experiments are described using a partial repetition priming paradigm. The prime type was whether a kanji character is used as a word by itself (word type) or not (nonword type). This property is called kanji lexicality. In Experiment 1, the effect of kanji lexicality was not confirmed, although there was a tendency in the responses for word-type primes to be slower than those for nonword-type primes. In Experiment 2, the kanji lexicality effect depended upon the target familiarity, and no facilitation was obtained for high-familiarity words with word-type primes. The results were interpreted in terms of a modified interactive-activation framework.

Cognition↗
PubMed1994

The Einsteck-method: position and structure of projections formed by implants of a ventral character.

The behavior of colored beads and of various living tissues after implantation into the Xenopus blastocoel is investigated. It is confirmed that the location of a graft along the anteroposterior axis depends on its intrinsic anteroposterior character. Comparison with the behavior of the beads suggests that the final position can be achieved by movement of the graft around the dorsoventral circumference of the inner marginal zone during gastrulation. Ventral marginal explants, or animal caps treated with fibroblast growth factor, both form ventral vesicles if cultured in isolation, but in the implantation experiments they often yield projections containing segmented muscle blocks. This behavior does not occur when the axis of the host has been suppressed by ultraviolet irradiation and so it is concluded that it represents dorsalization of the graft by the host. The tail-like structures formed as a result of ventral-type tissue implantations do not contain neural tissue, while the mesodermal parts are typically of mixed graft and host origin.

Animals↗
PubMed1995

Influence of androgens on differentiation of secondary sex characters in tree lizards, Urosaurus ornatus.

Vertebrates species vary in the degree to which the sexes differ in their expression of secondary sex characters, which can be expressed in one sex but not the other, fully expressed in both sexes, or expressed to different degrees in the two sexes. Sex steroid hormones contribute to the development of sex differences, either through action early in life (organization), following sexual maturation (activation), or both. However, relatively little is known about the contributions of sex steroid hormones to species-level variation in sexual dimorphism. We began to address this by assessing in tree lizards, Urosaurus ornatus, the effects of testosterone (T) and dihydrotestosterone (DHT) on expression of the male-typical traits: femoral pore secretions, accessory sex tissues, patches of ventrolateral blue, intensity and hue of throat color, and body size. We administered long-lasting hormone implants of these androgens to intact or ovariectomized adult females, intact hatchling females, and intact hatchling males to determine the relative contribution of organizational and activational influences of androgens on sexual differentiation of these traits. Waxy femoral pore secretions and full intensity of the orange background color of the throat fan (dewlap) required only activation and both androgens were equally effective. Both androgens caused hypertrophy of accessory tissues associated with the hemipenes, but only in hatchling males. Full expression of ventrolateral blue patches required organization by DHT. Androgens had complex organizational actions on growth. In the doses used in the experiment, DHT inhibited body-length growth but not mass growth of hatchling males. Only T inhibited the growth (length and mass) of hatchling females. Because earlier work found that castration also reduced the growth of hatchling males, the organizational effects of androgen on growth might be dose-related. Results for hormonal control of dewlap type were complex. In this population dewlap color is solid orange in females, but polymorphic in males with 50% expressing solid orange (O) and 50% orange-blue (orange with a central blue patch, OB). These color morphs represent permanent male alternatives: OB males are territorial and more aggressive than O males who do not defend territories. Results of the hormone manipulations are most consistent with the interpretation that dewlap morph type requires both organization and activation by androgen. T appears to be more important in organizing morph differences, whereas DHT appears to be more important in activating expression of underlying morph differences. Females only expressed male-typical OB dewlaps when given DHT, and only about 50% did so.

Animals↗
PubMed1997

A new model for discrete character evolution.

The paper provides an explicit justification for the principle that a uniform taxon should contribute only one datapoint in comparative analyses with discrete variables. The justification is that phylogenetic patterns in variables unincluded in the proposed test vitiate the assumption of independence, both at the level of species and at the level of branch segments. The consequence is that a uniform taxon cannot safely be counted as more than one datapoint. The arguments use a branching discrete Markov process in continuous time, with the new feature that the tested variables are only a subset of the evolving characters. This model is proposed as a useful criterion for measuring the merit of proposed tests, and illustrates the necessity for models in evaluating comparative methods.

Adaptation, Biological↗
PubMed1997

Coevolutionary chase on exploiter-victim systems with polygenic characters.

I study the dynamics of a simple quantitative genetic model describing coevolution of two antagonistic species of the victim-exploiter type. In this model, individuals are different with respect to an additive polygenic character that is under direct stabilizing selection and which also determines the strength of within and between species interactions. The model assumes that between species interactions are most intense when the victim's and exploiter's phenotypes match. I show that a cyclic coevolutionary chase is possible under a broad range of conditions. In most cases, the system cycles if the "victim" has a stronger incentive to win and/or a larger genetic variance, and is under stronger stabilizing selection than the "exploiter". The results presented here provide counter-examples to recent studies that (1) question the applicability of "Red Queen" and "arms race" metaphors for continuously varying traits; (2) argue for the existence of crucial differences between major and minor loci dynamics; and (3) attribute a stabilizing role to coevolution.

Animals↗
PubMed1998

Character congruence of multiple data partitions and the origin of the Hawaiian Drosophilidae.

We address two systematic questions, the origin and monophyly of the Hawaiian Drosophilidae and the question of how to analyze multiple data partitions containing disparate kinds of information, in this study. New evidence, from analysis of characters from morphology, mitochondrial DNA, and nuclear DNA suggests that the Hawaiian Drosophilidae are a monophyletic assemblage. Although we are not able to suggest a single species group which may represent the continental sister taxon to the Hawaiian Drosophilidae, the candidates suggested by our analysis, the melanicarobusta lineage and the virilis-repleta lineage, have been suggested by other investigators as probable sister taxa. Through analyses of our data partitions separately and in a variety of combinations, we conclude that the best phylogenetic hypothesis to be generated from multiple data partitions will be obtained if the data from these partitions are combined and analyzed simultaneously. We advocate performing tests for congruence between and among data partitions not to justify keeping them apart, but for understanding the interactions among the signals included in the analysis and how they affect the topology of, and support for, the total evidence tree.

Animals↗
PubMed1998

Molecular phylogenetics of finches and sparrows: consequences of character state removal in cytochrome b sequences.

The complete mitochondrial cytochrome b genes of 53 genera of oscine passerine birds representing the major groups of finches and some allies were compared. Phylogenetic trees resulting from three levels of character partition removal (no data removed, transitions at third positions of codons removed, and all transitions removed [transversion parsimony]) were generally concordant, and all supported several basic statements regarding relationships of finches and finch-like birds, including: (1) larks (Alaudidae) show no close relationship to any finch group; (2) Peucedramus (olive warbler) is phylogenetically far removed from true wood warblers; (3) a clade consisting of fringillids, passerids, motacillids, and emberizids is supported, and this clade is characterized by evolution of a vestigial 10th wing primary; and (4) Hawaiian honeycreepers are derived from within the cardueline finches. Excluding transition substitutions at third positions of codons resulted in phylogenetic trees similar to, but with greater bootstrap nodal support than, trees derived using either all data (equally weighted) or transversion parsimony. Relative to the shortest trees obtained using all data, the topologies obtained after elimination of third-position transitions showed only slight increases in realized treelength and homoplasy. These increases were negligable compared to increases in overall nodal support; therefore, this partition removal scheme may enhance recovery of deep phylogenetic signal in protein-coding DNA datasets.

Animals↗
PubMed2000

Phylogeny and character behavior in the family Lemuridae.

A phylogenetic analysis of the family Lemuridae was accomplished using multiple gene partitions and morphological characters. The results of the study suggest that several nodes in the lemurid phylogeny can be robustly resolved; however, the relationships of the species within the genus Eulemur are problematically nonrobust. The genus Varecia is strongly supported as the basal genus in the family. Hapalemur and Lemur catta are strongly supported as sister taxa and together are the sister group to the genus Eulemur. E. mongoz is the most basal species in the genus Eulemur. E. fulvus subspecies form a monophyletic group with three distinct lineages. E. coronatus is strongly supported as the sister taxon to E. macaco. The relationships of E. rubriventer, E. fulvus, and the E. macaco-E. coronatus pair are unresolved. Our combined molecular and morphological analysis demonstrates the lack of influence that morphology has on the simultaneous analysis tree when these two kinds of data are given equal weight. The effects of several extreme weighting schemes (removal of transitions and of third positions in protein-coding regions) and maximum-likelihood analysis were also explored. We suggest that these other forms of inference add little to resolving the problematic relationships of the species in the genus Eulemur.

Animals↗
PubMed2000

Phylogenetic relationships, character evolution, and biogeography of the subfamily Lygosominae (Reptilia: Scincidae) inferred from mitochondrial DNA sequences.

Phylogenetic relationships among the lygosomine skinks were inferred from 1249 base positions of mitochondrial DNA sequences of 12S and 16S rRNA genes. The monophyly of this subfamily was confirmed and the presence of five distinct infrasubfamilial lineages detected. Of these, the Sphenomorphus group appears to have diverged first, followed by the Lygosoma and Egernia groups in order, leaving the Eugongylus and Mabuya groups as sister groups. Our results did not support monophyly of the Mabuya group sensu lato (i.e., an assemblage of the Lygosoma, Egernia, and Mabuya groups), for which a number of morphological and karyological studies demonstrated a considerable similarity. Our results also contradict the previous hypothesis, formulated on the basis of morphological and immunological data, which argued for the sister relationship between the Egernia and the Eugongylus groups. Morphological and karyological characters used to define the Mabuya group (sensu lato) may actually represent plesiomorphic states. The phylogenetic diversity of lygosomine skinks in the Australian region appears to have increased through multiple colonizations from Southeast Asia.

Animals↗
PubMed2000

Phylogenetic analysis of the repleta species group of the genus Drosophila using multiple sources of characters.

The species in the repleta group of the genus Drosophila have been placed into five subgroups-the mulleri, hydei, mercatorum, repleta, and fasciola subgroups. Each subgroup has been further subdivided into complexes and clusters. Extensive morphological and cytological analyses of the members of this species group have formed the foundation for the proposed relationships among the members of the repleta species group. Fifty-four taxa, including 46 taxa belonging to the repleta species group, were sequenced for fragments of four genes-16S ribosomal DNA (16S), cytochrome oxidase II (COII), and nitrogen dehydrogenase 1 (ND1) of the mitochondrial genome and a region of the hunchback (hb) nuclear gene. We also generated a partial data set of elongation factor 1-alpha (Ef1alpha) sequences for a subset of taxa. Our analysis used both DNA characters and chromosomal inversion data. The phylogenetic hypothesis we obtained supports many of the traditionally accepted clades within the mulleri subgroup, but the monophyly of taxonomic groups outside of this subgroup appears not to be supported. Phylogenetic analysis revealed one well-supported, highly resolved clade that consists of closely related members of the mulleri and buzzatii complexes. The remaining taxa, a wide assortment of taxonomic groups, ranging from members of other species groups to members of several subgroups and members of three species complexes from the mulleri subgroup are found in poorly supported arrangements at the base of the tree.

Animals↗
PubMed1976

Lymphocyte subpopulations: analysis of T-cell rosette characters.

The data indicated that 2 populations of thymocytes existed: immature and mature types, identifiable by their rosette characters. The immature type was capable of changing spontaneously to the mature type, but was partially suppressed in vivo by the high concentration of thymic hormone present in the intrathymic environment. The mature types of thymocytes emigrated to the peripheral organ, accounting for their high percentage of small rosettes. Alternately, cells of peripheral organs might have originated from the immature type in the thymus. Once emigrated and exposed to a lower concentration of thymic hormone, they changed into the mature pattern. The fact that lymph node rosettes were less affected by culture in vitro indicated that once cells have changed to the mature pattern they have less ground for further differentiation.

Animals↗
PubMed1990

Inconsistencies in standard approximations for selection coefficients at loci affecting a polygenic character.

Inconsistencies exist in the standard expansions used to approximate selection coefficients for alleles at a locus underlying a quantitative character. Allelic (marginal) fitnesses obtained from expansions based on average excesses differ from allelic fitnesses obtained from expansions based on genotypic values. Similarly, W, the mean population fitness based on summing over either allelic or genotypic fitnesses usually differs mean population fitness obtained by averaging over the unrestricted phenotypic distribution. A consistent value of W requires no variation in genotypic values. If, as suggested by Nagylaki (1984), expansions are corrected for the decrease in phenotypic variance resulting from conditioning on the presence of a particular allele or genotype, inconsistencies still exist. Unless integral of W(z)[Vzp"(z) + zp'(z) + p(z)] dz = 0, where p(z) is the phenotypic probability density function, Vz the phenotypic variance, W(z) the fitness of phenotypic value z, the primes denote differentiation with respect to z, allelic fitnesses based on average effects differ from allelic fitnesses based on genotypic values. This condition must also be satisfied in order for either expansion to give a consistent W, as first shown by Nagylaki. For arbitrary W(z), this is satisfied if and only if phenotypes are normally distributed.

Alleles↗
PubMed1991

Representing word context effect in Chinese character perception--an application of information theory.

The perception of a letter in the context of a word is easier than in the context of a random letter sequence. It appears that our knowledge about words can influence our perception process. McClelland and Rumelhart (1981) propose an interactive activation model to account for the interaction between our knowledge about words and our visual input. They use their model to explain how these interactions facilitate perception. In their account, word context effect is a constant independent of the identity of the words. In this paper, we propose the use of information theory to quantify word context effect. In this way, the strength of word context effect will depend on the identity of the words. We apply the method to quantify word context effect in Chinese words. This knowledge is encoded in an artificial neural network using the interactive activation and competition model. The network is used to recognize Chinese characters and we are able to achieve a high recognition rate.

China↗
PubMed1989

Establishment of three human renal cell carcinoma cell lines (SMKT-R-1, SMKT-R-2, and SMKT-R-3) and their characters.

We have established three new cell lines of human renal cell carcinoma (RCC), designated as SMKT-R-1, SMKT-R-2 and SMKT-R-3. These cell lines were derived from a primary lesion of the tumor or a tumor initially xenotransplanted in nude mice. These cell lines have maintained a stable growth in vitro for more than a year. They also exhibited characteristics showing a lack of contact inhibition of cells, colony formation in soft agarose and tumor formation in nude mice by a xenotransplantation of cells, all of which suggested an epithelial origin. The tumors produced in nude mice by the inoculation of cell lines were demonstrated by light an electron microscopy to be derived from RCC. The doubling time of these cell lines were 180.0 h, in SMKT-R-1, 56.4 h in SMKT-R-2 and 55.7 h in SMKT-R-3. The cell lines were aneuploid in their chromosomal analysis, and SMKT-R-2 and SMKT-R-3 also had three and two marker chromosomes, respectively. The different biological characters of these cell lines from the others so far established would be of benefit in the future study of human RCC.

Animals↗