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At least 19 recordsLinked to original sources
PubMed1976

Cell size and mutual cell adhesion. I. Increase in mutual adhesivenes of HeLa cells from density-inhibited suspension cultures by hypotonic treatment.

HeLa cells harvested from density-inhibited or fast growing suspension cultures, were incubated in NaCl solutions of different tonicity. Cell size enlargement produced by hypotonicity is accompanied by an increased sedimentation rate of the density-inhibited cells, whereas no appreciable change is observed in the sedimentation rate of fast growing cells. Hypotonicity also has no effect on the sedimentation rate of density-inhibited cells which previously had been treated with neuraminidase or trypsin. It is shown that the effect of hypotonicity on density-inhibited cells cannot be ascribed to release of cell surface sialic acids during hypotonic incubation. Several arguments are presented which indicate that the changes in sedimentation rate, as measured in the rotating suspension system, are not the direct consequence of the alterations in cell size, but rather must be attributed to differences in intercellular adhesiveness resulting from the size alterations. Analogous changes in intercellular adhesiveness and cell size are shown to occur during growth in isotonic suspension culture. The results can be explained by assuming that changes in cell size affect the intercellular adhesiveness by modifying the extent to which cell surface sialic acids counteract adhesion.

Agglutination Tests↗
PubMed1975

Mutual assistance and support in retirement housing.

Among the advantages claimed for elderly residents of age-concentrated housing are the networks of mutual assistance among neighbors that may ensue. The extent to which these serve compensatory functions to replace mutual assistance with children has been a source of debate. The present paper compares networks of mutual assistance reported (in peronal interviews) by 600 residents of six facilities for the well-elderly with such assistance reported by matched controls living in dispersed housing. An earlier paper reported that site residents, relative to their controls, had less frequent contact with children but more frequent contact with neighbors. The present analysis shows, however, that there was little test-control difference in help received from children. More mutual assistance with neighbors, relative to controls, was found at two sites, less mutual assistance at two sites, and no difference at two. Finally, a cumulative rather than a compensatory effect was found between mutual assistance with children and with neighbors.

Aged↗
PubMed2026

Mutual Information-based Prognostic Biomarker Discovery in Cancer Genomics: Conceptual Framework and Representative Applications of MI-POG.

Mutual information (MI)-based approaches have increasingly been applied to cancer genomics; however, their use for genome-wide prognostic biomarker discovery remains relatively underexplored. The present article summarizes the conceptual workflow of Mutual Information-based Prognostic Omics Gene (MI-POG) based on previously published applications in breast cancer, lower-grade glioma, and other cancer datasets. The framework consists of clinical endpoint discretization, genome-wide MI-based screening, candidate ranking, and downstream validation using conventional survival-analysis approaches. Previous MI-POG applications identified solute carrier family 20 member 1 (SLC20A1) as a prognostic biomarker in hormone receptor-positive breast cancer. Elevated SLC20A1 expression was associated with unfavorable survival outcomes and was independently validated in the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) cohort. Methodological analyses demonstrated how survival endpoints can be integrated into an information-theoretic framework through fixed-time outcome discretization, enabling model-independent assessment of molecular-clinical dependencies. Applications across multiple cancer datasets suggested the potential applicability of the framework across biologically distinct tumor types, although further validation will be required to establish its robustness and generalizability. In conclusion, MI-POG can be formalized as an information-theoretic framework for genome-wide identification of prognostic biomarkers by quantifying molecular-clinical dependencies using mutual information. Representative applications from previously published studies suggest that MI-POG may complement conventional survival-analysis approaches and provide a useful strategy for biomarker discovery, although additional benchmarking and prospective validation will be required.

Humans↗
PubMed1977

Prevention, infant therapy, and the treatment of adults. 1. Toward understanding mutuality.

This is the first in a series of papers about the relevance of infant therapy to the treatment of adults. A description of maternal and infantile movement patterns is used to substantiate our thesis that not only does the mother hold the child, but the child holds the mother. A good-enough holding environment is maintained when the mother's adult patterns of effort and shaping dovetail with the infant's inborn reflexes to make mutual holding possible. Mutual support enables mother and child attune in tension-flow rhythms (used for need satisfaction) and to adjust in shape-flow rhythms (used for intake and output). Attunement is the physical core of empathy, and adjustment is the cradle of trust. Empathy and trust between therapist and patient develop in a good-enough holding environment which is derived from mutual holding in early infancy. Not only does the therapist provide a holding environment for the patient, but the patient does his share to support the therapist in his aims.

Female↗
PubMed2026

Concurrent ecological and evolutionary processes contribute to mutualism breakdown between legumes and rhizobia.

Though they jointly shape community responses to environmental perturbations, ecology and evolution are often examined separately, even in microorganisms where both occur over short timescales. Here we examine ecological and evolutionary responses to 33 years of nitrogen fertilization using the legume-rhizobium mutualism. Pairing a manipulative inoculation study with full-length 16S rRNA gene amplicon sequencing and structural equation modeling allows us to synthesize across biological scales: whole bacterial community, genus Rhizobium, Rhizobium ASVs, and symbiosis plasmids. Clover's preferred partner decreases in N-addition soils, limiting host growth, while a diverse and largely uncharacterized Rhizobium community increases. This ecological change is compounded by a concurrent evolutionary degradation of symbiont partner quality via changing frequencies of symbiotic plasmids. Ecological (rarer symbionts) and evolutionary (inferior symbionts) processes each accounted for roughly half of this loss of host benefit, revealing that ecology and evolution jointly shape mutualism breakdown over the short timescales typical of microbial systems.

ecology↗
PubMed1976

The concentration dependence of the hemoglobin mutual diffusion coefficient.

Laser correlation spectroscopy was used to measure the mutual diffusion coefficient, D, of human cyanomethemoglobin (Fe+++:CN) at varying protein concentrations. These measurements were made at 20 degrees C in a 0.1 M phosphate buffer solution at pH 7.0. For low protein concentrations we find D = (6.43 +/- 0.26) X 10(-7) cm2/s and that there is a near linear decrease from this value at higher concentrations. The linear relation between the diffusion coefficient and protein concentration allows us to deduce the value of the linear frictional volume fraction coefficient, Kf=7.75, and to extrapolate to hemoglobin concentrations equivalent to that in the red blood cell where we estimate D = 4.25 X 10(-7) cm2/s. Various theoretical predictions of the dependence of the mutual diffusion coefficient on concentration are tested; we find that the generalized Stokes-Einstein relation can be made to fit our high concentration data if we assume a hard-sphere model and if we include a term involving a hydrodynamic interaction integral.

Cyanides↗
PubMed1976

Mutual visual regard during mother-infant play.

Mutual visual regard was observed in 48 mother-infant dyads during a 6-min. play session. Infant-mother dyads containing 4 mo. -olds displayed significantly more mutual visual regard than dyads containing 6- or 8-mo.-olds. In addition, the more time infants spent in face-to-face interaction with mother, the more smiling they engaged in. No sex difference were observed.

Age Factors↗
PubMed2026

Resolving the "Yucca queretaroensis problem": Phylogenomic analysis of Yucca reveals the identity of an enigmatic species and the origin of an obligate pollination mutualism.

PREMISE: The genus Yucca is a group of ~50 species of woody monocots endemic to the North American arid regions. Their obligate pollination mutualism with yucca moths is considered a "textbook example" of coevolution and is hypothesized to have promoted rapid diversification. However, testing this hypothesis has been difficult due to uncertainty about the placement of a rogue taxon, Yucca queretaroensis, a rare endemic of the Sierra Gorda region of central Mexico. Past work placed this species in different positions within the Agavoideae, producing starkly different age estimates for Yucca (25 to 4 million years). METHODS: We generated new sequence capture data for 353 nuclear genes and for all coding regions of the plastid genome from wild-collected plants and samples included in previous studies to provide a new phylogeny and new age estimate for Yucca. RESULTS: The data presented here suggest that Y. queretaroensis is closely related to other species of Yucca. A relaxed molecular clock analysis of the plastid genome produced an estimated age for the genus of approximately 6.8 million years. CONCLUSIONS: The results resolve a mystery that has bedeviled evolutionary biologists for decades and provide a surprisingly young estimate for the age of Yucca, suggesting rapid diversification. The past difficulties in identifying the correct placement of Y. queretaroensis appear to be the product of laboratory errors, mistakes in field identification, and frequent hybridization with co-distributed taxa. The "Yucca queretaroensis problem" reaffirms the essential role for traditional botanical tools in phylogenomics.

ASTRAL↗
PubMed1976

A virus-specified mechanism for the prevention of multiple infection--T7- and T3-mutual and superinfection exclusion.

Co- and superinfection of cells with T3/T7 result in exclusion (mutual or superinfection exclusion). The exclusion mechanism is also directed against homologous (or identical) virus. Exclusion is established after the adsorption but before the genome becomes available for gene expression or replication, that is only one virus per cell develops. The exclusion is triggered by a constituant of the viral particle. An early T7 gene (M gene) (Schweiger et al., 1975) is essential for the formation of exclusion competent virions.

Bacterial Proteins↗
PubMed1976

Cell size and mutual cell adhesion. II. Evidence for a relation between cell size, long-range electrostatic repulsion and intercellular adhesiveness during density-regulated growth in suspension.

The strength of the long-range electrostatic repulsion forces on HeLa cells is measured by agglutinative titration using low molecular weight polylysine (M.W. 11,000). Repulsion forces, found to be present on the smaller HeLa cells from density-inhibited suspension cultures, are weakened by incubation of the cells in hypotonic NaCl solutions. Repulsion forces, found to be absent on the larger cells from fast growing cultures, can be induced on these cells by incubation in hypertonic NaCl solutions. Both effects of anisotonicity are reversible, and disappear on restoration of the medium to normal tonicity. Induction of repulsion forces on fast growing cells is prevented by previous treatment of the cells with neuraminidase. Neuraminidase also abolishes repulsion on density-inhibited cells. It is proposed that alterations of the cell size, produced by anisotonicity or occurring during growth in isotonic suspension medium, affect mutual cell adhesiveness by modifying the strength of the repulsion forces generated by cell surface sialic acids.

Agglutination Tests↗
PubMed1978

The formation of contacts between HeLa cells. Directed mutual outgrowth of cell surface protrusions.

The contacting behavior of HeLa cells in subconfluent monolayer cultures has been studied by phase contrast and scanning electron microscopy. We present further evidence that cells separated from each other by a cell-free space up to 20 micron width can simultaneously form directed and mutual protrusions against each other. A statistical analysis demonstrated that in more than half of the possible contact events a reciprocal outgrowth of cell surface protrusions had occurred. This suggests that contact formation is not just a random process, but may be influenced by so far unrecognized factors.

Cells, Cultured↗
PubMed1975

Joint use of light, X-ray and neutron scattering for investigation of RNA and protein mutual distribution within the 50S subparticle of E. coli ribosomes.

The values of the RNA and protein radius of gyration obtained in these studies corroborate the conclusion reported earlier [1] that on average the RNA is nearer to the center of the particle than is the protein. (It should be noted for comparison that the minimal Rg value of the RNA corresponding to its dense packing as a sphere in the center of the 52S subparticle is 49 A.) Moreover, such a great difference in the radii of gyration of RNA and protein implies a definite scheme of mutual RNA and protein arrangement in the 50S subparticle -- namely the distribution of the greater mass of proteins on the RNA surface.

Bacterial Proteins↗
PubMedDate not supplied

Electrophysiological evidences of mutual modulatory influences on the retinal activity of the crayfish Procambarus bouvieri (O).

Electroretinographic evoked potentials (ERGs) were recorded in dark adapted crayfish by the application of pulses of light (0.09 Cd/ft2) presented every 2.5 min. Heterolateral illumination (HI) for sixty min (0.06-0.3 Cd/ft2) induced up to 50% decrease in ERG after a latency of 12-25 min. ERG depression was proportional to the intensity of HI and also showed a circadian rhythm. During the alpha phase the ERG recovery started 3-10 min after HI was turned off. In contrast it started only after 10-20 min during the rho phase. The time course of the ERG depression, which was abolished in splitbrain animals, strongly suggests that a mutual modulatory influence, probably of neuroendocrine nature, is present in the crayfish visual system.

Animals↗
PubMed1979

Opposite and mutually antagonistic effects on uterine contractility of two epimeric forms of a synthetic prostaglandin analog.

Comparisons were made of the ability of intravenous infusions of prostalene and PGF2 alpha to stimulate increases in uterine contractility in vivo in the 14 day pregnant hamster. Whereas PGF2 alpha gave a linear dose response over the range 0.25 to 6.25 microgram/min., to achieve 5 fold increase in uterine activity, prostalene induced a multiphasic dose response curve. Inhibition was observed at 0.01 microgram per min. followed by a shallow stimulatory dose response to 0.25 microgram/min. plateauing at 1.8 fold stimulation to at least 1.25 microgram per min. When the epimeric mixture was separated and the two 15 position epimers studied separately the reason for this atypical dose response curve became clear. The 15 alpha OH epimer induced a linear stimulatory dose response from 0.05 to 6.25 microgram per min. infusion rates to a 5 fold increase in uterine contractility. The 15 beta OH epimer, however, induced a linear inhibitory dose response over the range 0.4 to 50 ng/min. It was, therefore, apparent that the atypical dose response curve observed from the mixture was the resultant of two opposite and mutually antagonistic activities. The data suggests also that the inhibitory epimer is capable of antagonizing both endogenous and exogenous prostaglandin, probably by a mechanism of competitive inhibition.

Animals↗
PubMed1979

Intestinal metallothionein and the mutual antagonism between copper and zinc in the rat.

A study has been made of the mechanism of the mutual antagonism between copper and zinc in rats. Dietary zinc concentrations of up to 450 mg/kg had no effect on intestinal 64Cu absorption but 900 mg/kg caused a 40% reduction. This was associated with an increase in the mucosal uptake of 64Cu in the small intestine. This occurred mainly in the form of metallothionein and it appeared that copper displaced zinc from the protein after its synthesis had been induced by zinc. Ths intestinal absorption of 65Zn was decreased by 20% when the dietary copper intake was increased from 3 to 24 mg/kg. Further increases in copper intake to 300 mg/kg did not cause any additional decrease in 65Zn absorption or any change in the association of intestinal 65Zn with metallothionein. Concentrations of this protein in the intestinal mucosa were not influenced by dietary copper intake.

Animals↗
PubMed1975

Correlation proton magnetic resonance studies at 250 MHz of bovine pancreatic ribonuclease. III. Mutual electrostatic interaction between histidine residues 12 and 119.

The two adjacent active site histidine residues of bovine pancreatic ribonuclease A (histidine-12 and -119) yield proton magnetic resonance titration curves having Hill coefficients significantly less than unity (0.7 and 0.8, respectively). Three models postulating interactions with other titrating groups in the molecule have been used to approximate these anomalous experimental titration curves. Very good agreement with the data was obtained with models postulating mutual electrostatic interaction between histidine-12 and -119. The additional low pH perturbation of the chemical shift of the C(2)-H peak (but not the C(4)-H peak) of histidine-12 is attributed to a local conformational change with a pHmid of about 3.5.

Amino Acid Sequence↗
PubMed2025

Spatial mutual nearest neighbors for spatial transcriptomics data.

MOTIVATION: Mutual nearest neighbors (MNN) is a widely used computational tool to perform batch correction for single-cell RNA-sequencing data. However, in applications such as spatial transcriptomics, it fails to take into account the 2D spatial information. RESULTS: Here, we present spatialMNN, an algorithm that integrates multiple spatial transcriptomic samples and identifies spatial domains. Our approach begins by building a k-nearest neighbors (kNN) graph based on the spatial coordinates, prunes noisy edges, and identifies niches to act as anchor points for each sample. Next, we construct a MNN graph across the samples to identify similar niches. Finally, the spatialMNN graph can be partitioned using existing algorithms, such as the Louvain algorithm to predict spatial domains across the tissue samples. We demonstrate the performance of spatialMNN using large datasets, including one with N = 31 10x Genomics Visium samples. We also evaluate the computing performance of spatialMNN to other popular spatial clustering methods. AVAILABILITY AND IMPLEMENTATION: Our software package is available on GitHub (https://github.com/Pixel-Dream/spatialMNN). The code is available on Zenodo (https://doi.org/10.5281/zenodo.15073963).

Algorithms↗