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Biomedical subjects

J M Oliver

Publications and source records attributed to J M Oliver.

At least 109 records · Page 6Linked to original sources
PubMed1985

Surface functions during mitosis in rat basophilic leukemia cells.

At the entry into mitosis, cells abruptly lose membrane activities such as phagocytosis, pinocytosis, and capping. The present studies test if mitotic cells also resist functional responses to cell surface ligand-receptor interactions. The IgE receptors of RBL-2H3 rat basophilic leukemia cells were labeled with anti-dinitrophenol IgE (anti-DNP-IgE) and then cross-linked with multivalent ligands (DNP-bovine serum albumin [BSA]; DNP-B-phycoerythrin; DNP-BSA-gold). IgE-receptor cross-linking modulates cell surface organization and function and releases serotonin and other mediators of allergic and asthmatic reactions from interphase cells (Pfeiffer, J. R., JC. Seagrave, B. H. Davis, G. G. Deanin, and J. M. Oliver, 1985, J. Cell Biol., 101:2145-2155). It was found that anti-DNP-IgE-receptor complexes are preserved on the cell surface throughout mitosis; they continue to bind DNP-proteins, and the resulting antigen-IgE-receptor complexes can redistribute to coated pits on the cell surface. Furthermore, there is no loss of [3H]serotonin through mitosis. Nevertheless, antigen-stimulated [3H]-serotonin release is strongly impaired in mitotic-enriched as compared with mixed interphase or G1-enriched cell populations. In addition, antigen binding transforms the surface of interphase cells from a microvillous to a plicated topography and stimulates the uptake of fluorescein isothiocyanate-conjugated dextran by fluid pinocytosis. Mitotic cells maintain a microvillous surface topography after antigen treatment, and fluid pinocytosis virtually ceases from prometaphase to telophase. Phorbol myristate acetate, a tumor promoter that activates protein kinase C, restores surface ruffling activity to mitotic cells. Thus, the mitosis-specific freezing of membrane and secretory responses is most likely due to the failure of transmembrane signaling.

Animals↗
PubMed1985

The Beck Inventory: psychometric properties in university students.

The psychometric properties of the Beck Inventory (BI), a revised, copyrighted version of the Beck Depression Inventory (BDI), were investigated in 204 university students. Two-week test-retest reliability was .90, coefficient alpha was .87, concurrent validity using the BDI as the criterion was .94, and the correlation between level of depression as measured by the two instruments was .86. The mean score on the BI was significantly but only one-half point lower than that on the BDI. Individual items were all highly and significantly correlated, but a significantly lower BI mean score occurred on the Sadness, Suicidal Ideas and Insomnia items. Depression was not significantly related to demographic variables.

Adolescent↗
PubMed1983

Cell motility and microtubules in cultured fibroblasts from patients with Kartagener syndrome.

Patients with Kartagener syndrome (KS) show defects in ciliary and flagellar movement that are usually associated with the partial or total absence of dynein side arms from axonemal microtubules. Dynein is essential for such movements, but its involvement in other cellular (particularly microtubule-related) processes is unknown. It has recently been reported that neutrophils from KS patients show impaired motility including responses to chemotactic stimuli, suggesting that dynein-like proteins may be generally involved in motile processes. In support of this, we have now found that spontaneous motility of cultured skin fibroblasts from KS patients is also markedly impaired. Three cell lines derived from skin explants of KS patients with deficient dynein side arms in nasal cilia and eight cell lines derived from normal volunteers were studied. Fibroblasts were seeded into dishes containing colloidal gold-coated cover glasses [Albrecht-Buehler, 1977], incubated for 24h at 37 degrees C, and the area of cell "phagokinetic" tracks determined. Each cell line studied in this manner reproducibly displayed an amount of spontaneous motility characteristic for that cell line. The mean track area (+/- SE) for all control cells studied was 14.6 +/- 0.5 X 10(3) micron2 whereas for KS fibroblasts was 8.7 +/- 0.4 X 10(3) micron2 (P less than 0.001). Immunofluorescence microscopy using antitubulin and antihuman 210 K MAP antibodies revealed no differences in the staining patterns between control and KS fibroblasts. Pinocytic rates were identical, and the complement of tubulin and major microtubule associated proteins as seen on one-dimensional SDS polyacrylamide gel autoradiographs appeared similar for control and KS cells. Thus, the observed motility defect is probably not the result of alterations in the occurrence or distribution of microtubules or in the occurrence or binding of the major microtubule-associated proteins. This defect in cellular motility may be related to the absence of dynein or may reflect another independent cellular defect.

Adenosine Triphosphatases↗
PubMed1983

Surface and cytoskeletal events regulating leukocyte membrane topography.

The experiments reviewed here establish that surface components and surface functions can assume predictable, asymmetric patterns within the continuous plasma membranes of mammalian leukocytes. Recent biophysical and morphological studies show that receptor redistribution can occur very rapidly and that a unique geometric association is maintained between moving receptors and surface geometry. Based on these experimental data, a new working model for surface topographical control has been proposed. Its essence is the entrainment of certain receptors and receptor complexes on membrane waves that are generated by microfilament-membrane interaction. Several pathological conditions associated directly or indirectly with cytoskeleton and membrane abnormalities have been described. The continued application of modern biochemical, immunologic, and biophysical techniques to probe the underlying defects should provide new insight into the mechanisms of leukocyte response to surface stimulation.

Cell Membrane↗
PubMed1982

Distribution of receptors and functions on cell surfaces: quantitation of ligand-receptor mobility and a new model for the control of plasma membrane topography.

The long-range movements of membrane ligand-receptor complexes into surface caps and into the pseudopods of cells performing phagocytosis, the uropods of motile cells and the cleavage furrows of dividing cells appear to be analogous processes. A common mechanism to explain these movements must take into account several recent observations. First, laser photobleaching studies have indicated that Concanavalin A-receptor movement occurs unidirectionally; and analyses of Con A redistribution by quantitative video intensification microscopy (QUAVIM) have shown that movement may exceed the maximum rates measured for protein diffusion in membranes. These are the results predicted for a process of directed migration but not for a process of diffusion with entrapment. In addition it has been found that membrane receptors may segregate out of as well as into cap, pseudopod, uropod and cleavage furrow regions and that topographical heterogeneity on asymmetric cells is not restricted to membrane molecular determinants but extends to a range of endocytic functions and to a macromolecular complex, the coated pit. All dynamic surface events are arrested during mitosis. A new model for the regulation of plasma membrane topography has been developed from these diverse quantitative, functional and morphological data. Its essence is the entrainment of selected membrane determinants on membrane waves directed towards regions such as caps, pseudopods, uropods and cleavage furrows. The waves are initiated by tension due to asymmetric microfilament-membrane interaction.

Animals↗
PubMed1982

The effects of child maltreatment on language development.

The separate effects of child neglect, abuse, and their interaction upon language development as measured by the Preschool Language Scale were examined in four groups of children (n = 79) in a quasi-experimental design. There were three groups of maltreated subjects, all drawn from a treatment center: an abused only group (n = 13), a neglected only group (n = 7), and an abused and neglected group (n = 31); a non-maltreated group (n = 28) was drawn from a day care center. Abuse, neglect, and their interaction were used to predict both auditory comprehension and verbal ability as separate criteria in two stepwise multiple regression equations, where the variance attributable to gender and mother's status on Aid to Dependent Children had been removed. Child neglect was found to predict significantly both auditory comprehension and verbal ability. Neither child abuse nor the interaction between abuse and neglect significantly predicted either dependent variable. These findings suggest that child neglect may be the critical type of maltreatment associated with language delay.

Child↗
PubMed1982

Surface functions during mitosis. III. Quantitative analysis of ligand-receptor movement into the cleavage furrow: diffusion vs. flow.

The surface distribution of concanavalin A (Con A) bound to cell membrane receptors varies dramatically as a function of mitotic phase. The lectin is distributed diffusely on cells labeled and observed between mid-prophase and early anaphase, whereas cells observed in late anaphase or telophase demonstrate a marked accumulation of Con A-receptor complexes over the developing cleavage furrow (Berlin, Oliver, and Walter. 1978. Cell. 15:327-341). In this report, we first use a system based on video intensification fluorescence microscopy to describe the simultaneous changes in cell shape and in lectin-receptor complex topography during progression of single cells through the mitotic cycle. The video analysis establishes that fluorescein succinyl Con A (F-S Con A)-receptor complex redistribution begins coincident with the first appearance of the cleavage furrow and is essentially complete within 2-3 min. This remarkable redistribution of surface fluorescence occurs during only a modest change in cell shape from a sphere to a belted cylinder. It reflects the translocation of complexes and not the accumulation of excess labeled membrane in the cleavage furrow: first, bound fluorescent cholera toxin which faithfully outlines the plasma membrane is not accumulated in the cleavage furrow, and, second, electron microscopy of peroxidase-Con A labeled cells undergoing cleavage shows that there is a high linear density of lectin within the furrow while Con A is virtually eliminated from the poles. The rate of surface movement of F-S Con A was quantitated by photon counting during a repetitive series of laser-excited fluorescence scans across dividing cells. Results were analyzed in terms of two alternative models of movement: a flow model in which complexes moved unidirectionally at constant velocity, and a diffusion model in which complexes could diffuse freely but were trapped at the cleavage furrow. According to these models, the observed rates of accumulation were attainable at either an effective flow velocity of approximately 1 micron/min, or an effective diffusion coefficient of approximately 10(-9) cm2/s. However, in separate experiments the lectin-receptor diffusion rate measured directly by the method of fluorescence recovery after photobleaching (FRAP) on metaphase cells was only approximately 10(-10) cm2/s. Most importantly, photobleaching experiments during the actual period of F-S Con A accumulation showed that lectin-receptor movement during cleavage occurs unidirectionally. These results rule out diffusion and make a process of oriented flow of ligand-receptor complexes the most likely mechanism for ligand-receptor accumulation in the cleavage furrow.

Animals↗
PubMed1982

Effect of highly selective vagotomy on pancreatic exocrine function and on cholecystokinin and gastrin release.

The effect of highly selective vagotomy on pancreatic exocrine function and the release of gastrin and cholecystokinin was studied in 10 patients with endoscopically-proven duodenal ulceration. Cholecystokinin and gastrin concentrations in serum both increased significantly after highly selective vagotomy. Amylase concentration in the duodenal aspirate increased significantly after vagotomy, but trypsin concentration remained unchanged. The expected reductions in gastric acid secretion were noted. Thus highly selective vagotomy reduces acid secretion effectively in patients with duodenal ulcer without impairing the exocrine function of the pancreas.

Amylases↗