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Biomedical subjects

R Goldman

Publications and source records attributed to R Goldman.

At least 127 records · Page 7Linked to original sources
PubMed1984

Effect of retinoic acid on the proliferation and phagocytic capability of murine macrophage-like cell lines.

Retinoic acid (RA) exerted a variable degree of growth inhibitory activity on the macrophage-like cell lines P388D1, J774.2, WEHI-265, WEHI-3, and PU-5. Comparison of cell proliferation and clonal growth suggests that at concentrations of 10(-9)-10(-6) M the inhibitory activity stems from processes leading to elongation of cell cycle time and not from terminal differentiation processes. RA was shown to be a potent inducer of the development of high-phagocytic phenotypes (assessed by phagocytosis of heat-killed yeast cells) in the P388D1, J774.2, and WEHI-265 cell lines which differ substantially in their proliferative and adherence characteristics. The PU-5 and WEHI-3 cell lines were not induced by RA to express an enhanced phagocytic activity toward heat-killed yeast cells. The augmented phagocytic capability was dose dependent over a wide range of RA concentrations. In P388D1 cells, 2 X 10(-12) M RA already exerted significant phagocytosis augmentation effects, which progressively increased up to 2 X 10(-5) M RA, the highest concentration tested. Retinal, retinyl acetate, and retinol had similar effects to those of RA on both cell adherence and phagocytosis in P388D1 cells, albeit at concentrations four to six orders of magnitude higher. Optimal development of the high-phagocytic phenotype in P388D1, J774.2, and WEHI-265 cells required at least 96 hr of culture in the presence of RA; at 48 hr and 23 hr the effects were already substantial, whereas at 4 hr of exposure to RA no significant enhancement of phagocytosis could be detected. Thus both extended periods of culture in the presence of RA (more than two to three cell cycles) and high concentrations were needed for induction, in more than 90% of the cells, of the expression of a high-phagocytic phenotype. The reversion to a low-phagocytic phenotype upon removal of RA was also rather slow and required several cell cycles. In P388D1 cells RA also enhanced the phagocytosis of latex beads but had no effect on the phagocytosis of starch particles, or the extent of binding of immunoglobulin G-coated sheep red blood cells (SRBC). The expression of receptors for concanavalin A and for nonopsonized SRBC remarkably increased in RA-treated cells, as was the ability to perform Fc-receptor mediated erythrophagocytosis. Both P388D1 cells and WEHI-265 cells were induced by RA to express nitroblue tetrazolium reducing activity. The data suggest that RA induces profound changes in the functional capabilities of macrophage-like cell lines which are apparently not dependent on cessation of growth and terminal differentiation processes.

Animals↗
PubMed1984

Inhibition of bacterial aggregation by serum- and blood-derived proteins.

Human and animal sera contain potent inhibitors of saliva-mediated aggregation of oral streptococci. The inhibitors consist of a high-molecular-weight heat-labile factor and a lower-molecular-weight heat-activated factor. The latter appears to be serum albumin. Analyses of purified blood-derived proteins indicated that several high-molecular-weight proteins (fibrinogen, fibronectin, and ferritin) were able to inhibit aggregation at low concentrations. These data suggest that high-molecular-weight proteins may modulate the aggregation process.

Animals↗
PubMed1984

Prostacyclin release following endoperoxide analogue infusion in the intact dog.

We examined the systemic and coronary hemodynamic responses after infusion of an endoperoxide analogue U 46,619 in anesthetized dogs and related the hemodynamic effects to the release of thromboxane A2 (TXA2) and prostacyclin (PGI2). Immediately after U 46,619 infusion, increases in mean arterial and left ventricular end-diastolic pressures (LVEDP) occurred, whereas coronary and aortic blood flows were unchanged. Calculated vascular resistances in the systemic and coronary vascular beds increased significantly. At 3-5 min after infusion, mean arterial pressure and LVEDP spontaneously decreased and vascular resistances also declined, whereas coronary and aortic blood flows were unchanged. Simultaneously measured plasma TXB2 and 6-keto-PGF1 alpha (stable hydrolysis metabolites of TXA2 and PGI2, respectively) increased in the femoral and coronary arterial blood samples in conjunction with the vasoconstrictor effects. At 3-5 min, plasma 6-keto-PGF1 alpha concentrations showed a further increase, whereas TXB2 concentrations slightly decreased, suggesting release of PGI2 as a possible mechanism of vasodilation. To examine this possibility, nine dogs were treated with cyclooxygenase inhibitors (aspirin or indomethacin) and given U 46,619. In these animals neither vasoconstrictor nor vasodilator effects were observed. Plasma TXB2 and 6-keto-PGF1 alpha concentrations also did not increase after U 46,619. These data show that the vasoconstrictor and platelet aggregatory agent U 46,619 results in PGI2 release in the dog. Release of PGI2 may be a protective and autoregulatory mechanism in the canine systemic and coronary vascular beds.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1984

A quantitative analysis of C3 binding to O-antigen capsule, lipopolysaccharide, and outer membrane protein of E. coli 0111B4.

The binding of serum C3 to the O-antigen capsule (OAg Cap), lipopolysaccharide (LPS), and outer membrane proteins (OMP) of Escherichia coli 0111B4 was examined. Bacteria were intrinsically labeled with [3H] or [14C]galactose (*gal) in the OAg Cap and LPS moieties or with [14C]leucine (*leu) to label proteins. Organisms were then incubated in serum containing differentially labeled C3, the above fractions were separated, and the proportion of each binding to a column containing anti-C3 was measured. The OAg Cap fraction bound 72 to 82% of the C3, which bound to E. coli 0111B4 during incubation in absorbed 10% pooled normal human serum (10% PNHS) or absorbed 40% C8-deficient serum (C8D). This distribution did not change when the organism was presensitized with immune IgG before serum incubation. A total of 2.93% +/- 0.48 of OAg Cap and 0.52% +/- 0.16 of LPS *gal bound specifically to Sepharose-containing antibodies to C3 (A:C3-Seph) after incubation in 10% PNHS; these values increased to 10.1% +/- 4.5 and 1.8% +/- 0.3, respectively, when C3 deposition was increased fourfold by incubation in 40% C8D. When encapsulated E. coli 0111B4 was incubated in 10% PNHS containing biotinylated C3, specific attachment of OAg Cap *gal to avidin-Sepharose was demonstrated in 1% sodium dodecyl sulfate (SDS), and complete release of bound *gal but not C3 occurred with 1 M NH2OH. When a mutant of E. coli 0111B4 lacking OAg Cap was incubated in 40% C8D, the outer membrane (OM) bound 85% of C3. Five percent of OM *gal from the unencapsulated organism bound to A:C3-Seph in 0.05% SDS, indicating that the fraction of LPS molecules with bound C3 increased threefold in the absence of OAg Cap. OAg Cap does not contain protein, and no net specific binding of *leu from OAg Cap fractions to A:C3 was detectable; 2.4 to 3.6% of OM *leu bound to A:C3-Seph. Immunoprecipitation of 82.9% of OAg Cap *gal with antisera that were directed to E. coli 0111B4 was associated with co-precipitation of 69.5% of C3 in the capsular fraction. Therefore, the majority of C3 bound to E. coli 0111B4 was covalently attached to OAg Cap and LPS. As corroboration of experiments with whole bacteria, purified OAg Cap and purified LPS consumed C3 when incubated in serum in the fluid phase. These results are the first to evaluate the acceptor site for C3 deposition on a Gram-negative organism incubated in serum, and show that LPS, OAg Cap, and OMP are all major acceptor sites for C3 in nonimmune serum.

Animals↗
PubMed1984

Induction of a high phagocytic capability in P388D1, a macrophage-like tumor cell line, by 1 alpha, 25-dihydroxyvitamin D3.

1 alpha, 25-Dihydroxyvitamin D3 [1,25-(OH)2D3] was shown to induce a high phagocytic capability in the macrophage-like murine tumor cell line P388D1. Induction of phagocytic capability by 1,25-(OH)2D3 was dose-dependent in the range of 0.2 to 5.0 ng/ml, required the continuous presence of the secosteroid in culture, and was reversible. 25-Hydroxyvitamin D3 was an effective inducer only at about 500 ng/ml, while 24R,25-dihydroxyvitamin D3 was ineffective. The induction of the high phagocytic capability was neither accompanied by increased synthesis of lysozyme nor closely associated with an inhibitory effect on cellular proliferation. P388D1 cells bound (without ingestion) nonopsonized sheep erythrocytes (sheep RBC), and the binding increased in 1,25-(OH)2D3-treated cells. Fc-receptor-mediated binding of immunoglobulin G-coated sheep RBC was not modulated in 1,25-(OH)2D3-treated cells, but the cells acquired an Fc-receptor-mediated phagocytic capability that was expressed only when preformed P388D1-sheep RBC rosettes were further exposed to immunoglobulin G. Several differentiation agents of myeloid leukemia cells (including dexamethasone) were not effective in inducing the high-phagocytic phenotype, while retinoic acid was very effective. Different myeloid or macrophage-like tumors (WEHI-265, J774.2, PU-5, and WEHI-3) were variable in their response to 1,25-(OH)2D3.

Animals↗
PubMed1983

Neurotensin modulates human neutrophil locomotion and phagocytic capability.

Neurotensin (NT) was found to induce oriented locomotion and augment the phagocytic capability of human blood neutrophils over 10(-11) - 10(-7) M. The tridecapeptide also causes Ca2+ extrusion from neutrophils, very likely as a result of intracellular Ca2+ mobilization. It is suggested that the NT-mediated functional modulation of neutrophils correlates with the capacity of NT to affect the intracellular compartmentalization of Ca2+. Peripheral NT-elicited phenomena such as vasodilation, enhanced vascular compartmentalization of Ca2+. Peripheral NT-elicited phenomena such as vasodilation, enhanced vascular permeability, mast cell degranulation and the enhancement of directional migration and phagocytosis of neutrophils described here, classify NT as a typical mediator of inflammation.

Calcium↗
PubMed1983

Modulation of bacterial aggregation by PMN and platelet extracts.

Human parotid saliva contains agglutinins which bind to the surface of streptococci and induce the formation of bacterial aggregates. Bacterial aggregation can be blocked by proteins released from viable PMNs and platelets or by sonic extracts prepared from these cells. PMN and platelet inhibitors display characteristic differences in molecular weight, protease, and temperature sensitivity. The mechanism of action of the inhibitors appears to involve a direct interaction with the salivary agglutinins rather than with the bacteria. It is thus possible that PMN and platelet-derived products might modulate saliva-mediated bacterial aggregation and thereby influence the course of infections in the oral cavity.

Agglutinins↗
PubMed1983

Children's perceptions of sex differences in babies and adolescents: a cross-national study.

A sample of 838 children aged 5-15 in Australia, England, North America, and Sweden were interviewed about physical and sexual development. One section covered how children perceived sex differences. Criteria used for scoring were based on a biological realism scale. In identifying sex differences of newborn babies, a progression from realistic to unrealistic recognition was observed with increasing age in all countries. The Swedish younger age groups were more realistic than their English-speaking peers, with the latter catching up in the teenage years. In discerning pubertal sex differences, children tended to move from presexual ideas between 9 and 11 years and to have achieved full sexual answers between 13 and 15 years. Evidence did not support the latency period theory or the presence of castration fantasies in children. Cross-national differences are discussed and their implications explored.

Adolescent↗
PubMed1983

The silent abdominal abscess: role of the radiologist.

An abdominal abscess usually causes severe distress with fever, leukocytosis, pain, and toxicity. However, a small but significant proportion of patients with abdominal abscess may appear entirely well with no elevated temperature or white blood cell count. Fifteen patients are reported whose initial clinical presentation was unremarkable but who had significant abscess formation that was well documented by radiographic methods. Both the radiologist and the patient's primary physician must be aware of the not infrequent presentation of abdominal abscess in a clinically innocuous manner. The lack of fever, elevated white blood cell count, or patient complaint should in no way rule out the diagnosis of abscess when positive radiographic evidence is found.

Abdomen↗
PubMed1983

On the origin of macrophage heterogeneity: a hypothesis.

Data are summarized suggesting an inherent heterogeneity of bone marrow macrophage precursor cells. The possible relationship of this heterogeneity with the functional heterogeneity of blood monocytes and tissue macrophages under normal conditions and at an inflammatory site is discussed. A hypothesis suggesting that the bone marrow compartment is involved in the generation of macrophage heterogeneity is presented.

5'-Nucleotidase↗
PubMed1982

Beta-galactosidase--an indicator of the maturational stage of mouse and human mononuclear phagocytes.

Resident, elicited, and activated mouse peritoneal macrophages exhibit a differential expression of the activity of the enzyme beta-galactosidase; freshly harvested resident macrophages express a remarkably high activity whereas the latter two populations are almost void of enzymic activity. During in vitro cultivation there is an enhancement in the level of the enzyme in the three populations, and a significant proportion of both thioglycollate-elicited and Corynebacterium parvum-activated macrophages acquire beta-galactosidase activity. Cells within in vitro differentiated bone marrow-derived mononuclear phagocyte colonies are heterogeneous with respect to expression of beta-galactosidase activity. The percentage of cells expressing medium to intense enzymic activity is augmented with time in culture. Essentially the same pattern is observed in colonies differentiated from bone marrows of mice bearing acute or chronic inflammation. Freshly isolated human peripheral blood monocytes are essentially void of detectable beta-galactosidase activity. Eighty to ninety percent of the monocytes acquire medium to intense activity during a 7-day cultivation period. The data support the suggestion that beta-galactosidase expression in mononuclear phagocytes is a correlate of their maturational stage both in vivo and in vitro and does not reflect the state of elicitation or activation of these cells.

Animals↗
PubMed1982

Enhancement of phagocytosis by neurotensin, a newly found biological activity of the neuropeptide.

Specific binding of neurotensin (NT) to mouse peritoneal thioglycollate-elicited macrophages and macrophages differentiated in vitro from bone marrow cells was demonstrated and characterized. NT binding to these phagocytes modulated their phagocytic capacity in a biphasic manner. At concentrations of 10(-14) to 10(-9) M NT, a dose-dependent augmentation of phagocytosis (up to 2-fold) was observed. Further increases in the concentration of NT resulted in a gradual decrease of the augmented response until the basal phagocytic activity (in the absence of NT) was reached. Three partial sequences of NT, NT (8-13), NT (6-13) and NT (1-10), were also effective in augmenting the phagocytic response of thioglycollate elicited macrophages, but the maximal effect was attained at about 10(-7) M and stayed at that level up to a concentration of 10(-5) M. The activity of the three NT partial sequences was comparable to that of substance P and tuftsin. Scatchard analysis of (3H)NT binding to macrophages suggested the existence of two populations of binding sites, a major population of relatively low affinity binding sites and a small population of high affinity binding sites. NT (8-13), NT (6-13), substance P and tuftsin competed with (3H)NT binding to the low affinity sites with a comparable KI to that of NT. NT (1-10) did not compete for the binding at the low affinity sites. It is suggested that NT binding to the high affinity sites leads to enhancement of phagocytosis, whereas its binding to the low affinity sites leads to inhibition of the augmented response. However, the low affinity sites are the sites of interaction of NT (8-13), NT (6-13), substance P and tuftsin with the phagocytes and their saturation with the peptides leads to augmentation of phagocytosis.

Amino Acid Sequence↗