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Biomedical subjects

C G Peterson

Publications and source records attributed to C G Peterson.

At least 19 recordsLinked to original sources

Update in allergy testing in childhood asthma: how do you know whether you are successfully controlling the patient's inflammation?

The levels of serum eosinophil cationic protein (ECP) in asthmatic patients have been shown to be increased in acute and undertreated asthma as a result of inflammation. ECP is released during in vitro clotting of peripheral blood. The exposure of the atopic individual to an offending allergen stimulates the activation of the blood eosinophils and their release of ECP into serum. Serum ECP levels reflect avoidance of the allergen, and successful treatment of asthma inflammation with corticosteroids cause a reduction of the inflammation in the lung. When individual patients with asthma are followed, the level of serum ECP can be used (1) as an early indicator of the degree of inflammation, (2) for monitoring the efficacy of corticosteroid therapy, and (3) for possible noncompliance with treatment.

Anti-Inflammatory Agents

The differential release of eosinophil granule proteins. Studies on patients with acute bacterial and viral infections.

BACKGROUND: Earlier in vitro studies have suggested that the eosinophil may release its granule proteins selectively depending on the stimulus to which the cell is exposed. OBJECTIVE: The object of the present study was to study the question of selective release in vivo by means of serum measurements of the two eosinophil granule proteins eosinophil cationic protein (ECP) and eosinophil peroxidase (EPO) in acute infections. METHODS: Fourty-six subjects with acute infections were studied before treatment, 20 with bacterial infections and 26 with viral infections. Serum ECP, EPO and MPO were measured by specific RIA. RESULTS: In acute bacterial infections ECP, but not EPO, was significantly raised in serum (P < 0.0001) compared with non-infected healthy subjects. In acute bacterial infections ECP was significantly correlated to the levels of the neutrophil marker myeloperoxidase (MPO) (rs = 0.96, P < 0.0001) but not to EPO. In acute viral infections neither ECP nor EPO were on average raised. However, almost 20% the patients had elevated levels of bot proteins. In the viral infections the serum-levels of ECP and EPO were correlated (rs = 0.63, P < 0.001), but no correlation was found with MPO. CONCLUSION: It is concluded that eosinophils are activated during acute bacterial infections and that this activation results in the preferential mobilisation of ECP. The simultaneous assay of the two eosinophil proteins, ECP and EPO, may give new insight into the role of the eosinophil in disease.

Acute Disease

Icons in surgery.

This company of surgeons, the Pacific Coast Surgical Association, has honored me greatly, and I am grateful. In a turbulent, changing world, as physicians, you are among the most important people on earth. More important, by far, than any technologic aspect of your craft, is your character. As the pen is mightier than the sword, your beliefs and values are the sustaining force that will guide you in troubled times. Icons are Everyman's "pointers of the way" in meeting the challenges of tomorrow.

Entrepreneurship

Indirect evidence of nasal inflammation assessed by titration of inflammatory mediators and enumeration of cells in nasal secretions of patients with chronic rhinitis.

Pathophysiologic mechanisms of perennial rhinitis are poorly understood. The characterization of inflammation was studied in nasal lavage of patients with perennial rhinitis by the enumeration of cells involved in the allergic inflammation and the measurement of six mediators released in nasal secretions to determine whether some mediators were relevant for the etiologic diagnosis and the occurrence of symptoms. Ten healthy subjects and 57 patients with perennial rhinitis were placed into four groups according to the symptoms they presented at the time of the study and the origin of the allergy. Allergy was characterized by the history, skin prick tests to standardized allergens, and RAST. Eosinophil protein X (EPX), tryptase, histamine, myeloperoxidase, prostaglandin D2, and leukotriene C4/D4 (LTC4/D4) were measured in nasal lavage by enzyme assay or radioimmunoassay. Eosinophils and neutrophils were enumerated after cytocentrifugation of the lavage fluid and May Grunwald Giemsa staining. Tryptase, myeloperoxidase and EPX but not histamine levels were increased in all four patient groups. Eosinophils, LTC4/D4, and prostaglandin D2 were significantly (p < 0.001, p < 0.03, and p < 0.01) increased in allergic and symptomatic patients. EPX was significantly increased in symptomatic allergic and nonallergic patients. This study suggests the involvement of mast cells, neutrophils, and eosinophils, but the latter cells appear to have a more prominent role. The importance of EPX and LTC4/D4 in the characterization of chronic symptomatic rhinitis was also observed.

Adolescent

Eosinophil cationic protein alters proteoglycan metabolism in human lung fibroblast cultures.

Eosinophil cationic protein (ECP), a highly basic protein secreted from eosinophilic granulocytes, has been shown to take part in the inflammatory reaction. The involvement of ECP in fibroblast activation was therefore investigated in cell culture. Production of proteoglycans, hyaluronan and collagen in the presence of ECP was measured after incorporation of radioactive precursors and separation into different proteoglycan classes using gel and ion exchange chromatography and hydrophobic interaction chromatography. Proteoglycan accumulation in the cell layer was increased two- to fivefold at an ECP-concentration of 10 micrograms/ml. No effect on collagen, other proteins or hyaluronan was noted. Furthermore, no effect was observed on cell proliferation. The increased proteoglycan accumulation could be inhibited by addition of heparin or of antibodies to ECP. The effect could not be mimicked by the two basic peptides protamine and poly-L-lysine, speaking in favor of specificity. The increase in proteoglycan material was seen exclusively in the intracellular pool. No change of proteoglycans in the medium or the cell surface-associated pool was noted. The increase in the cell layer was accounted for by a two- to fivefold increase in free chains of heparan sulfate and dermatan sulfate. No change was seen in the proteoglycan pattern. No effect on proteoglycan synthesis or on endocytosis was noted. The increased accumulation of polysaccharide was caused by inhibited degradation of glycosaminoglycans. The half-lives of large and small heparan sulfate proteoglycans/glycosaminoglycans and dermatan sulfate proteoglycans/glycosaminoglycans in the cell layer are increased four- to sevenfold. We conclude that ECP inhibits proteoglycan degradation in fibroblasts, which indicates a role for the eosinophil in generation of fibrosis.

Blood Proteins

Radioimmunoassay of human eosinophil cationic protein (ECP) by an improved method. Establishment of normal levels in serum and turnover in vivo.

A radioimmunoassay was developed allowing measurement of the cytotoxic cationic ECP. The assay, which has a total incubation time of 3.5 hr, is a double antibody assay with radiolabelled ECP, covering the concentration range of 2-200 micrograms/l. Performance data show a detection limit of less than 2 micrograms/l and a cross-reactivity with eosinophil protein X (EPX/EDN) of less than 0.06%. The coefficient of variation (%) within the measuring range was, within assay 4.8-10.4, and total 6.6-12.0. The assay is useful for measurement in various body fluids including serum, nasal secretions and bronchoalveolar lavage fluid, and dilution of samples prior to analysis was generally not required. Sera from 100 apparently healthy individuals revealed a geometric mean of 6.0 micrograms ECP/l and a range (95%) of 2.3-15.9 micrograms/l. The elimination rate of ECP, t1/2, in vivo was estimated to be 65 min when ECP was measured in serum. Comparisons between this assay and a method previously described showed that the new method is superior with regard to precision and assay procedure.

Blood Proteins

Human eosinophil-derived neurotoxin and eosinophil protein X are likely the same protein.

The human eosinophil granule contains a series of cationic proteins. Two of these, eosinophil-derived neurotoxin (EDN) and eosinophil protein X (EPX), are reported to have similar m.w. and both possess neurotoxic and helminthotoxic activities. Therefore, the properties of these molecules were analyzed to determine whether they differ. EDN was purified from eosinophils of patients with the hypereosinophilic syndrome and EPX from the buffy coat cells of normal individuals. By SDS-PAGE, both proteins showed a major band at 18.7 kDa and a minor band at 21.4 kDa. By two-dimensional non-equilibrium gel electrophoresis the proteins migrated identically. With radiolabeled proteins in reverse phase HPLC, both proteins eluted at the same concentration of acetonitrile and showed identical tryptic maps. Both proteins possessed comparable ribonuclease activity and both were comparably neurotoxic in the rabbit. By immunodiffusion the two proteins showed a reaction of identity; by RIA, with both polyclonal and monoclonal antibodies, the proteins had very similar inhibitory activities. These results indicate that EDN and EPX have virtually identical properties and are probably the same protein.

Animals

The treatment of breast cancer: II. A 20-year follow-up and reappraisal of the en bloc principle.

This retrospective study of the extended Oregon Series (1940 to 1965) of patients with breast cancer, first reported in 1961, compares the now long-term results of treatment of pathologic stage T2/3 NO breast cancers with intent to cure by the following two en bloc ablative operative procedures of variable extent and completeness: standard radical mastectomy vs ultraradical mastectomy. The extent and completeness of the en bloc procedure are shown again to be critical determinants of local control and survival. The local recurrence rate for standard radical mastectomy is 12.4% (8/70) and for ultraradical mastectomy it is 0% (0/78). Proportionate survival at 20 years for standard radical mastectomy was 59.8% (95% confidence limits, 0.598 +/- 0.14) and for ultraradical mastectomy it was 98.1% (95% confidence limits, 0.981 +/- 0.04).

Breast Neoplasms

Purification and characterization of eosinophil cationic protein from normal human eosinophils.

ECP (eosinophil cationic protein) was purified in high yield from the granules of human buffy coat eosinophils obtained from healthy individuals. The separation procedure included gel filtration on Sephadex G-75, ion-exchange chromatography on Bio Rex 70, and chelating chromatography on zinc-chelate Sepharose 6B. The normal ECP is a single-chain, highly cationic glycoprotein which separates on SDS-polyacrylamide gel electrophoresis into at least 3 molecular weight forms, with molecular weights of 18.5, 20 and 22 kDa. A heterogeneity in charge was also observed, with the 18.5 kDa form being the most cationic one. The various molecular species of ECP exhibited antigenic identity, identical amino acid compositions, and identical amino-terminal amino acid sequences. The molecular heterogeneity was shown to be caused by differences in glycosylation of the protein.

Amino Acid Sequence

Eosinophil granule proteins in serum after allergen challenge of asthmatic patients and the effects of anti-asthmatic medication.

Thirteen allergic asthmatic patients were challenged six times each and serum levels of ECP (eosinophil cationic protein), EPX (eosinophil protein-x) and blood counts of eosinophil granulocytes were measured in blood obtained before and at regular intervals after challenge. Three challenges were performed in a blinded and randomized fashion and included a one-dose pretreatment with the inhalant anti-asthmatic drugs disodium cromoglycate, terbutaline and budesonide. One challenge was performed after 4 weeks' pretreatment with the inhalant budesonide and one was a histamine challenge. Pre-challenge levels of ECP were significantly reduced both after 4 weeks and after a one-dose treatment with budesonide whereas the EPX levels were reduced only after the former. Blood eosinophil counts were unaffected by the challenge whereas the ECP levels were significantly reduced after the placebo challenge and when premedicated with disodium cromoglycate and terbutaline. The EPX levels stayed unaltered at the placebo challenge but were significantly reduced when the patients were premedicated with terbutaline. ECP and EPX levels as well as blood eosinophil counts before challenge were significantly related to the development of the late asthmatic reaction. The results again focus on a relation between the eosinophil granulocyte and asthma and suggest that an increased activity of the blood eosinophil, as suggested by the raised serum levels of the granule proteins ECP and EPX, is one prerequisite for the development of chronic asthma.

Adult

Epithelial injury by human eosinophils.

The human eosinophil is armed with a number of very potent cytotoxic granule proteins that upon extracellular release may produce considerable damage. The toxic effect of the proteins seems to be quite unselective, involving most mammalian and nonmammalian cells including the epithelial cells. The demonstration of a close relation between the deposition of eosinophil granule proteins and areas of epithelial cell destruction in a variety of diseases including asthma and the fact that cytotoxic concentrations of the proteins have been measured in the fluid phase suggest that the eosinophil participates actively in the pathogenesis of airway diseases. The protection towards the adverse actions of the eosinophil, particularly towards their proteins, therefore seems vital. The discovery of alpha-2-macroglobulin as a specific binder of eosinophil cationic protein may be relevant in this regard.

Asthma

Interaction and complex-formation between the eosinophil cationic protein and alpha 2-macroglobulin.

The interaction between the highly basic and cytotoxic eosinophil cationic protein (ECP) and human plasma proteins is described. The major plasma protein responsible for complex-formation with ECP was shown to be the 'fast' form of alpha 2-macroglobulin (alpha 2M). Large amounts of complexes were observed in a serum obtained from a patient with hypereosinophilic syndrome. The amount of complexes that could be generated in vitro in normal fresh serum was rather low and was even less in fresh citrated plasma. Complex-formation between the non-proteolytic ECP and alpha 2M was augmented in the presence of methylamine. Binding of ECP to alpha 2M was also induced by the proteinases cathepsin G and thrombin, and the binding was competitive with cathepsin G. Methylamine and the proteinases seem to share a common mechanism in inducing binding of ECP. The nature of the ECP-alpha 2M interaction is non-covalent, but withstands high salt concentrations. The interaction with alpha 2M may reflect a mechanism by which the organism protects itself against the deleterious effects of the highly cytotoxic protein ECP.

Blood Proteins

Eosinophil activation in allergic disease.

The eosinophil granulocyte is a pro-inflammatory cell which in its granules contains an abundance of highly cytotoxic proteins such as eosinophil cationic protein, eosinophil-derived neurotoxin, eosinophil peroxidase, eosinophil protein X and major basic protein. Upon stimulation of the cell, these proteins as well as a number of lipid mediators such as leukotriene C4, prostaglandin and platelet-activating factor are released to the exterior. The molecules which are produced during inflammatory reactions of the allergic type attract eosinophils to the target organ and stimulate them to liberate their products. The physiological meaning of this reaction is probably to combat invading parasites; however, in their absence accumulation and activation of eosinophils may cause disease, and one such disease may be chronic asthma.

Asthma

Evaluation of injury mechanism as a criterion in trauma triage.

Triage of potentially injured patients to the appropriate trauma hospital was carried out using mechanism of injury as a triage criterion rather than physiologic changes (trauma score). Injury mechanism includes field evidence of high energy transfer, such as falls of more than 15 feet, automobile accidents with structural intrusion, extrication difficulties, passenger ejection, or death at the scene. Evaluation of triage decisions for a 3 month period in 631 patients showed an overtriage rate of 14 to 43 percent. Using the trauma score alone would have missed significant injuries in at least 8 to 36 percent of these patients using the injury severity score or clinical criteria. Methods of evaluation of overtriage and undertriage are presented, but accepted standards for these must be addressed in each trauma system. Injury mechanism as a primary trauma triage criterion is an acceptable means of identification of potential injury for transport to a trauma facility.

Allied Health Personnel

Human eosinophil cationic proteins (ECP and EPX) and their suppressive effects on lymphocyte proliferation.

ECP (eosinophil cationic protein) and EPX (eosinophil protein X) are two highly basic proteins contained in the granules of human eosinophils. In this study, the effect of ECP and EPX upon lymphocyte proliferation in vitro has been investigated. Peripheral blood mononuclear cells from normal donors were cultured in medium containing ECP or EPX at concentrations from 10(-10) to 10(-7) M. 3H-Thymidine incorporation in PHA-blasts or MLR-blasts was dose-dependently inhibited by both ECP and EPX. The effect was irreversible and was not due to cytotoxic damage. The suppressive effect of EPX may involve suppressor cells. The effect of ECP and EPX on lymphocyte proliferation at relevant in vivo concentrations suggests a regulatory role for the eosinophil in immunological reactions.

Blood Proteins

Elastase in the different primary granules of the human neutrophil.

Elastase in the human neutrophil is associated with various subpopulations of primary granules of different density. The proportion of this enzyme that is extracted with acetate pH 4.2 and cetyltrimethylammonium bromide varies in the different subpopulations. Nevertheless, the electrophoretic mobility and relative proportions of elastase isoenzymes is the same in both extracts from the different subpopulations. On stimulation of neutrophils with N-formylmethionylleucylphenylalanine, elastase is not released from the least dense subpopulation, whereas other two subpopulations do undergo degranulation to approximately the same extent. However, the release of elastase from these two denser granules differs after they are isolated and treated with calcium.

Cytoplasmic Granules