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Biomedical subjects

C L Anderson

Publications and source records attributed to C L Anderson.

At least 145 records · Page 8Linked to original sources
PubMed1985

Two distinct classes of IgG Fc receptors on a human monocyte line (U937) defined by differences in binding of murine IgG subclasses at low ionic strength.

We have defined two distinct classes of IgG Fc receptors (FcR) on cells of a human monocytic line (U937) by analyzing the direct binding of murine IgG subclasses in medium of low ionic strength. Four lines of evidence support this contention. The binding of aggregated murine IgG2b (AggmIgG2b) to U937 and Daudi cells was enhanced at low ionic strength, whereas monomeric murine IgG2a (mIgG2a) did not bind to Daudi cells and its high affinity binding to U937 cells was unaffected by changes in ionic strength. Double reciprocal inhibition experiments with U937 cells indicated that the binding of both ligands was inhibited 30 to 135 times more efficiently by the homologous ligand than by the heterologous one. That is, the binding of 125I-AggmIgG2b was inhibited 50% by 3.5 micrograms/ml of AggmIgG2b and 100 micrograms/ml of mIgG2a. Similarly, the binding of 125I-mIgG2a was inhibited 50% by 2.5 micrograms/ml of mIgG2a and only 44% by 243 micrograms/ml of AggmIgG2b. A monoclonal antibody of the IgG2b subclass raised against an IgG FcR on K562 cells inhibited binding to U937 cells of AggmIgG2b but not of mIgG2a. Trypsinization of U937 cells abrogated by 32% the binding of mIgG2a but did not affect the binding of AggmIgG2b. Human IgG inhibited binding of both AggmIgG2b and mIgG2a to U937 cells. We propose that the newly recognized FcR that binds AggmIgG2b is the human homologue of the murine macrophage IgG2b/1 FcR (FcRII), and that the previously described 72,000 dalton high-affinity FcR on U937 cells that binds mIgG2a is the human equivalent of the murine macrophage IgG2a FcR (FcRI).

Animals↗
PubMed1985

Characterization of a polyvalent antibody directed against the IgG Fc receptor of human mononuclear phagocytes.

We have raised an antibody to the IgG Fc receptor (FcR) of human mononuclear phagocytes by immunizing a goat with FcR purified by ligand affinity from a human monocyte line (U937). This antiserum, which inhibited the binding of IgG ligand to the receptors on U937, precipitated from detergent lysates of surface-radioiodinated U937 cells a 72 Kd sialoglycoprotein (p72) identified as the FcR by several previously published criteria. Two other bands seen in autoradiograms of SDS gels were precipitated by this antiserum: a 40 to 43 Kd band that co-purified with p72 and a 170 Kd protein that was not present in the immunogen. Fractionation of the IgG of this antiserum into two subclasses yielded one subclass (IgG1) in which anti-p72 activity was considerably enriched relative to antibody activities against other molecules. This antiserum precipitated p72 not only from U937 but from HL60 cells and from human peripheral blood monocytes as well, indicating common antigens on the p72 molecules from these three cells. However, p72 was not recovered from lysates of surface-iodinated human polymorphonuclear leukocytes or murine macrophage lines. Anti-p72 activity was not completely removed by adsorption with intact U937, suggesting that the antiserum recognizes portions of p72 that are not exteriorly disposed, perhaps noncarbohydrate portions of the molecule. We expect this antiserum to be useful for a number of studies of receptor structure and function.

Animals↗
PubMed1984

A widespread epidemic of mild necrotizing enterocolitis of unknown cause.

Within a 28-day period, necrotizing enterocolitis (NEC) developed in 20 of 38 infants (53%). Patients with NEC were compared with the remaining 18 infants hospitalized at the same time who did not acquire the disease. Complications of pregnancy and labor-delivery and infant care practices did not differ between groups. Mean chronologic age was significantly different between patients with NEC and those without, 29 days v 77 days. Mean postconceptional age at the time of the outbreak was also significantly different, 33.4 weeks v 42.3 weeks. None of the cultures demonstrated a specific common pathogen. The low mortality (5%) and the large number of infants affected suggest an atypical out-break of NEC. We could not isolate a causative agent despite extensive epidemiologic investigation, and suggest that postconceptional age delineates those at risk.

Age Factors↗
PubMed1984

Some recent pharmacological findings with nitrendipine.

The available evidence indicates that nitrendipine and other dihydropyridines with a similar pharmacological action exert their therapeutic effects by inhibiting Ca2+ channels. In our recent experiments, nitrendipine was shown to block K+-stimulated 45Ca2+ uptake and K+-induced contractions of isolated rabbit aortic rings. Its IC50 were 4.7 and 8.9 nM for inhibition of Ca2+ uptake and of contractions, respectively. There was no statistically significant difference between the two values. At higher concentrations, nitrendipine also reduced norepinephrine-induced 45Ca2+ uptake and norepinephrine-induced contractions of rabbit aortic strips. The norepinephrine-induced contractions were only slightly (21%) reduced by nitrendipine at 10 microM. Nitrendipine at 10 nM and higher concentrations inhibited K+- or angiotensin-II-(AII) induced release of aldosterone from isolated bovine adrenal glomerulosa cells. The drug was more potent and more effective in inhibiting K+- than AII-induced aldosterone release. Dantrolene, 25 microM, enhanced the inhibitory activity of nitrendipine on AII-stimulated aldosterone release. Acute renal failure produced by either glycerol or gentamicin in rats was antagonized by nitrendipine at oral doses of 15-25 mg/kg/day. Our studies confirmed previously reported observations that the usefulness of nitrendipine in the treatment of hypertension may be determined not only by its vasodilator action. We demonstrated that nitrendipine has a direct inhibitory effect on the release of aldosterone from adrenal glomerular cells. In addition to a previously described diuretic action, nitrendipine was shown to have renal cytoprotective activity.

Acute Kidney Injury↗
PubMed1984

Antagonism of Ca2+-induced constriction of isolated rabbit ear artery by nitrendipine in high K+- and/or norepinephrine-containing medium.

Nitrendipine is a Ca2+ channel antagonist with vasodilator and antihypertensive properties. In the present experiments, the isolated rabbit ear artery was perfused with Ca2+-free Krebs-bicarbonate solution. Constriction of the artery was induced by addition of Ca2+ to perfusion fluid in the presence of KCl (75 mM, high K+), norepinephrine (NE) at various concentrations, or high K+ and NE. Nitrendipine produced concentration-dependent inhibition of the constrictor response to Ca2+ in high K+ medium. NE, added to high K+ medium, reversed the inhibitory effect of nitrendipine. In NE-containing medium, nitrendipine also inhibited the constrictor effect of Ca2+. Nitrendipine-induced inhibition was inversely proportional to the concentration of NE in the medium. The inhibitory effect of nitrendipine in the medium containing high K+ and NE was significantly less pronounced than in normal K+- and NE-containing medium. The experiments demonstrate relative resistance of "receptor-operated" channels to nitrendipine and suggest that under depolarizing conditions these channels may operate more effectively.

Animals↗
PubMed1982

Isolation of the receptor for IgG from a human monocyte cell line (U937) and from human peripheral blood monocytes.

The Fc receptors for IgG from a human monocyte line (U937) and from highly purified human peripheral blood monocytes were solubilized, purified, and partially characterized. Both sources of cells gave indistinguishable results. Two molecules (or sets of molecules), one of about 72,000 mol wt and the other of 40,000-43,000 mol wt were discerned on autoradiograms of sodium dodecyl sulfate (SDS)-polyacrylamide gels analyzing acid eluates from Sepharose-IgG columns over which detergent lysates of radioiodinated cells had been passed. The larger of the two molecules, p72, accounted for greater than or equal to 90% of the radioactivity. This component was noted to be heterodisperse both by size on SDS gels and by charge on isoelectric focusing gels. The charge heterogeneity, being virtually eliminated by neuraminidase and tunicamycin, was probably due to variable glycosylation. Several lines of evidence indicated that p72 is probably all or part of the Fc receptor: (a) radiolabeling of this molecule using chloroglycouril was blocked by IgG of the Fc receptor; (b) in soluble form this molecule expressed ligand specificity identical to the in situ receptor; (c) the molecule was not recovered from affinity adsorbants bearing proteins that do not bind to the Fc receptors, nor (d) from a human T cell line that does not bear Fc receptors. The smaller of the two molecules isolated, p40-43, is at least in part actin. Its relationship to p72 is not understood.

Autoradiography↗
PubMed1982

Effect of anisomycin on stimulation-induced changes in dendritic spines of the dentate granule cells.

Tetanic stimulation of the entorhinal area induces significant enlargement of the average dendritic spine area and perimeter in the middle and distal thirds of the dentate molecular layer 4 and 90 min following stimulation. Four minutes after stimulation, the differences between the stimulated and control animals were 20% for the dendritic spine area and 9% for the perimeter in the middle third, and in the distal third 32 and 14%, respectively. Ninety minutes after stimulation the differences were 28 and 11% for the area and perimeter in the middle third, and 33 and 18% in the distal third, respectively. Anisomycin at a dose of 25 mg/kg had no significant effect on the average spine area or perimeter in the various thirds of the dentate molecular layer in the 19 and 105 min post-application intervals. This dose of anisomycin given 15 min prior to the stimulation suppresses the stimulation-induced spine changes in the 4 min interval. In the 90 min interval when the effect of anisomycin on protein synthesis is largely terminated, spine enlargement reappears, being 21% higher than the controls in the middle and distal thirds. The differential effect of anisomycin on dendritic spines in the two post-stimulation intervals is discussed in relation to the effect of anisomycin on protein synthesis. The present experiments thus demonstrate that the stimulation-induced spine enlargement in the dentate fascia can be suppressed by a protein synthesis blocking drug.

Animals↗
PubMed1982

Evaluation of neonatal neutrophil function using the combined immunobead/NBT dye reduction assay.

An improved assay for the simultaneous assessment of phagocytic uptake (via Immunobeads) and metabolic integrity (via NBT dye reduction) was used to evaluate the neutrophil function in neonates, one year olds, and adults. The unique advantage of this assay is that it evaluates both phagocytic and killing function simultaneously which appears to make the assay more reliable in the detection of neutrophil dysfunction. This assay allowed us to establish a subtle but significant neutrophil dysfunction in full term unstressed neonates which proved to be more pronounced in both the stressed and the preterm neonates. The one year olds, however, were found to have neutrophil function comparable to that of an adult.

Adolescent↗
PubMed1981

An analysis of maternal transport within a suburban metropolitan region.

Data on 185 infants transported for perinatal and/or neonatal care from suburban metropolitan hospitals were analyzed. Following birth, 100 infants were transferred from community hospitals. A total of 85 infants were transported in utero and delivered at a tertiary (Level III) perinatal center. Survival rate was 90% for infants transported in utero contrasted with 81% for the infant transports. This difference was not significant. When hospitalization cost and length of stay were used as an index of morbidity, there was a significant difference between the two groups. The mean hospitalization cost of survivors was $6,473 for in utero transports compared to $12,208 for infant transports (p less than 0.005). The mean length of stay for in utero transports was 19 days contrasted to 27 days for infant transports (p less than 0.05). The findings of this study indicate that in utero transports resulted in reduced morbidity for infants of high-risk pregnancies.

Female↗
PubMed1981

The granulocyte response to the phosphodiesterase inhibitor RO 20-1724 in asthma.

Isolated human granulocytes secrete the lysosomal enzyme beta glucuronidase when incubated with complement-activated zymosan particles. Isoproterenol inhibits this release, and the beta adrenergic response is associated with an increase in granulocyte cyclic adenosine monophosphate (cAMP) levels. In asthma, the beta adrenergic responsiveness is impaired. Cyclic AMP concentration in the granulocyte is also influenced by phosphodiesterase hydrolysis of this cyclic nucleotide. We found that the potent phosphodiesterase inhibitor, RO 20-1724, inhibited zymosan-stimulated beta glucuronidase release from granulocytes in a dose-dependent fashion (10(-8) to 10(-4) M). The inhibition of lysosomal enzyme release by RO 20-1724 was associated with an increase in granulocyte cAMP. Granulocytes were also isolated from asthmatic patients and the RO 20-1724 inhibition of beta glucuronidase release was compared with the response in normal subjects. The negative log molar median effective dose (ED50) value (mean +/- SE) was 5.98 +/- 0.69 in normal subjects and 5.90 +/- 0.63 in asthmatics. These observations suggest that the granulocyte metabolism modulated by the RO 20-1724-sensitive phosphodiesterase is equally responsive to this potent phosphodiesterase inhibitor in normal and asthmatic leukocytes.

4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone↗
PubMed1981

Cortisol protection of the granulocyte response to isoproterenol during an in vitro influenza virus incubation.

Isolated human polymorphonuclear leukocytes (PMNs) release beta glucuronidase (BG) lysosomal enzyme during incubation with complement-activated zymosan particles. In asthma, isoproterenol (ISO) and histamine (HIS) inhibition of PMN lysosomal enzyme release is impaired while the prostaglandin E1 (PGE1) response is normal. During a respiratory infection provoking asthma, the PMN response to ISO is further impaired. The PMN response to ISO, HIS, and PGE1 is similarly impaired following an in vitro incubation with a live influenza bivalent (A + B) vaccine. In the following study, granulocytes were isolated from normal (n = 10) and asthma patients (n = 29). The isolated cells were incubated with the bivalent influenza vaccine (1 PMN:1 egg infective dose50) for 30 min. Following this in vitro virus incubation, granulocytes from normal and asthma patients had an imparied response to ISO, HIS, and PGE1. Granulocytes from asthma patients having a history of wheezing with respiratory illnesses did not have a greater impairment in the agonist response following virus incubation than normals or allergic asthma patients. However, in asthma patients (n = 6) receiving prednisone (10 to 20 mg/day), the in vitro vaccine incubation did not impair the PMN ISO response. A similar protective effect was found if granulocytes were incubated with hydrocortisone (1,4 X 10(-4) M) prior to exposure to the influenza vaccine.

4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone↗
PubMed1981

Legionnaires' disease with severe hypoxemia and saddleback fever.

In the case of Legionnaires' disease described, severe respiratory problems necessitated mechanical ventilatory support, tracheal intubation, and positive end-expiratory pressure. Fever was eliminated with erythromycin therapy but returned after five days, and lung infiltrates spread. After supplementary treatment with other antibiotics and methylprednisolone sodium succinate, both the fever and the infiltrates disappeared. We feel that the multisystem involvement and the recrudescence of fever in our patient emphasize the wide spectrum of characteristics of Legionnaires' disease and the importance of continuation of antibiotics for a prolonged period to eradicate infection.

Adult↗
PubMed1981

The effect of a workshop on attitudes of female nursing students toward male homosexuality.

The responses of 64 female nursing students to the Survey of Attitudes Toward Deviance--Homosexuality Scale (May, 1974) indicated that they held more negative attitudes and more stereotyped beliefs regarding male homosexuality than did May's sample of male counselors and psychologists. After a 2-hour workshop, the attitudes of the 37 students in the experimental groups had changed and were similar to those expressed by May's sample. A testing 4 months later indicated that this change remained stable. Some attitudes relating to morality and social distance continued to be somewhat unfavorable. It made no difference in attitude change if the workshop presenters did or did not identify themselves as homosexual. The students with initially more negative attitudes toward homosexuality changed more as a result of the workshop experience than those with more positive attitudes. For both experimental and control subjects, more positive pretest attitudes toward homosexuality were associated with emotional stability, objectivity, good personal relations, restraint, friendliness, an interest in masculine activities, and greater support for equality of the sexes, as well as more liberal attitudes toward sex-appropriate behavior.

Adult↗
PubMed1981

Macrophage receptors for IgE: binding of IgE to specific IgE Fc receptors on a human macrophage cell line, U937.

Human IgE was found to bind to the human macrophage line U937. Binding was specific for IgE in that it was inhibited by 3 different human IgE myeloma proteins and by Fc fragments prepared from IgE, but not by IgE Fab fragments or by myeloma proteins representative of the 4 IgG subclasses or by a rat IgE myeloma protein. Dissociation and association rates were rapid, with estimated t1/2 of less than 1 min. The Ka was 4.15 X 10(7) liter/mol. Between 53,000 and 93,000 sites per cell were calculated. The U937 receptor for IgE was trypsin sensitive, whereas the receptor for IgG on the same cell was relatively trypsin resistant.

Antibody Affinity↗