Biomedical subjects

R D Rossen

Publications and source records attributed to R D Rossen.

At least 37 records · Page 2Linked to original sources

PubMed1992

Neutrophil adherence to isolated adult cardiac myocytes. Induction by cardiac lymph collected during ischemia and reperfusion.

Canine neutrophils can be induced to adhere in vitro to isolated adult cardiac myocytes by stimulation of the neutrophils with chemotactic factors such as zymosan-activated serum (ZAS) only if the myocytes have been previously exposed to cytokines such as interleukin 1 (IL-1) or tumor necrosis factor-alpha. These cytokines induce synthesis and surface expression of intercellular adhesion molecule-1 (ICAM-1) on the myocyte, and neutrophil adhesion is almost entirely CD18 and ICAM-1 dependent. The present study examines cardiac-specific lymph collected from awake dogs during 1-h coronary occlusion and 3 d of reperfusion for its ability to induce both ICAM-1 expression in cardiac myocytes, and neutrophil-myocyte adherence. Reperfusion lymph induced ICAM-1 expression in isolated myocytes, and myocyte adherence to ZAS-stimulated neutrophils that was completely inhibited by anti-CD18 and anti-ICAM-1 monoclonal antibodies. This activity peaked at 90 min of reperfusion and persisted for up to 72 h. Preischemic lymph was not stimulatory. IL-1 appeared not to be a stimulating factor in lymph in that dilutions of lymph were found to inhibit the stimulatory effects of recombinant IL-1 beta. However, investigation of interleukin 6 (IL-6) revealed that recombinant IL-6 stimulated myocyte adhesiveness for ZAS-stimulated neutrophils (ED50 = 0.002 U/ml) and expression of ICAM-1 by isolated myocytes. IL-6 neutralizing antibody markedly reduced the ability of reperfusion lymph to stimulate adhesion and ICAM-1 expression, and estimates of levels of IL-6 in reperfusion lymph ranged from 0.035 to 0.14 U/ml. These results indicate that cytokines capable of promoting neutrophil-myocyte adhesion occur in extracellular fluid during reperfusion of ischemic myocardium, and that one of these cytokines is IL-6. Neutrophil-myocyte adhesion may be of pathogenic significance because it may enhance the cytotoxic activity of the neutrophil.

Animals↗

PubMed1991

Inflammation in the course of early myocardial ischemia.

Experimental models of acute ischemic myocardial injury indicate that the inflammatory response after the ischemic event contributes to tissue damage. This is especially apparent with reperfusion of the ischemic tissue. In such models some therapeutic strategies designed to reduce neutrophil accumulation or function have resulted in apparently beneficial effects. Although such findings are encouraging, interventions into these pathological processes using specific molecular targets will require greater understanding of specific mechanisms. Current evidence indicates that potential sites of therapeutic intervention will be found in pathways leading to complement activation, generation of lipid-derived mediators, adhesion of neutrophils to endothelial cells and cardiac myocytes, and activation of neutrophil secretory processes releasing, for example, proteolytic enzymes and reactive oxygen. Understanding the dynamic interplay between the mediators, adhesion pathways, and secretory processes that results in myocardial damage will allow a rational approach to controlling the detrimental inflammatory consequences of ischemia and reperfusion.

Animals↗

PubMed1991

Neutrophil accumulation in ischemic canine myocardium. Insights into time course, distribution, and mechanism of localization during early reperfusion.

BACKGROUND: We have previously demonstrated that chemotactic factors released from the ischemic canine myocardium peak early during reperfusion and that they elicit neutrophil adherence reactions in vitro that are dependent on the CD18 glycoprotein family. In this study we investigated the hypothesis that neutrophil localization in ischemic canine myocardium in vivo occurs over a similar time course during early reperfusion and involves a CD18-dependent mechanism. METHODS AND RESULTS: We occluded the circumflex coronary artery for 1 hour in acute, open-chest dogs, followed by reperfusion for 1, 2, 3, or 4 hours. Regional myocardial blood flow was determined using radiolabeled microspheres, and localization was traced using technetium-99m-labeled autologous neutrophils. In the first hour of reperfusion, neutrophil localization occurred preferentially within the subendocardial region and was inversely related to flow. Neutrophil localization diminished across the ischemic myocardium from endocardium to epicardium but remained negatively related to flow in the midmyocardial region. Regardless of flow, little neutrophil localization occurred in the subepicardial region. Neutrophil localization was greatest in the first hour of reperfusion and diminished thereafter. By 4 hours of reperfusion, the rate of localization was markedly attenuated relative to 1 hour. Dogs given anti-CD18 monoclonal antibody R15.7 (1 mg/kg i.v.) before occlusion underwent 1 hour of occlusion followed by 1 hour of reperfusion. When compared with 1-hour reperfusion controls, the R15.7-treated dogs demonstrated significant attenuation of neutrophil localization in the subendocardial region. CONCLUSIONS: These data support the concepts that rapid neutrophil localization during reperfusion occurs within regions of previous myocardial ischemia and that neutrophils preferentially localize within the subendocardial region. The rate of neutrophil localization is greatest within the first hour after the initiation of reperfusion, and localization is, at least in part, CD18 dependent. Therapies directed against neutrophil-mediated reperfusion injury should be initiated with these considerations in mind.

Animals↗

PubMed1990

The effect of HIV infection on phagocytosis and killing of Staphylococcus aureus by human pulmonary alveolar macrophages.

Pulmonary alveolar macrophages (PAM) play a central role in host defense against pulmonary infection. The authors studied the number, viability, and ultrastructure of PAM recovered by bronchoalveolar lavage from normal and HIV-infected subjects, and their ability to phagocytose and kill Staphylococcus aureus. PAM from HIV-infected subjects who did not have pneumonia were present in greater numbers and phagocytosed significantly more opsonized Staphylococcus aureus (32.5% and 27.3% for nonsmokers and smokers, respectively) than did PAM from healthy controls (19.5% and 18.2%). In 15 patients with AIDS and pneumonia (due to Pneumocystis carinii in 13/15), viability of PAM and their phagocytic capacity were significantly reduced; in smokers with AIDS and pneumonia, the PAM yield was also dramatically decreased. Killing of S. aureus was similar by PAM from all patient groups. HIV infection was associated with the electron microscopic finding in PAM of extensively ruffled PAM cell-surfaces and ingestion of lymphocytes. Thus, HIV infection stimulates the phagocytic capacity and produces morphologic changes consistent with the possibility that PAM are activated by this retroviral infection. In patients with AIDS who develop pneumonia, especially in smokers, the number, viability and phagocytic capacity of PAM are significantly decreased; our study could not determine whether this diminished activity reflects evolution of the HIV infection or a secondary effect of the pneumonia.

Adult↗

PubMed1990

Increased elastase secretion by peripheral blood monocytes in cystic fibrosis patients.

Morbidity and mortality in cystic fibrosis (CF) is predominantly due to destruction of pulmonary tissue. The host immune response may, in part, play a pathogenic role in pulmonary destruction in these patients. To further understand host immune response in CF, we examined the state of activation of peripheral blood monocytes in CF. Baseline elastase activity was 2.2-fold greater in the CF monocytes than in controls. Pseudomonas aeruginosa mucoid exopolysaccharide (MEP) and high molecular weight polysaccharide (HMP) increased elastase activity in both control and CF monocytes, with a greater absolute increase in the CF monocytes. There was no difference in baseline or MEP-stimulated secretion of interleukin-1 (IL-1) or interleukin-6 (IL-6) between CF and control monocytes. Ibuprofen enhanced both MEP and HMP-stimulated elastase activity, whereas dexamethasone suppressed both baseline and stimulated elastase activity greater than 20% in both CF and control monocytes. These results suggest that circulating monocytes in CF are stimulated in vivo, resulting in a remarkably elevated elastase activity in vitro. Elevated elastase release by peripheral blood monocytes as they enter the lung in response to chemotactic stimuli may contribute to lung destruction in CF.

Adolescent↗

PubMed1989

Molecular basis of complement activation in ischemic myocardium: identification of specific molecules of mitochondrial origin that bind human C1q and fix complement.

Mitochondria may be a source of molecules that activate complement during ischemic injury to myocardium, providing therewith a stimulus for infiltration of polymorphonuclear leukocytes. To identify specific molecules that activate the classical complement pathway, detergent lysates of canine cardiac mitochondria were fractionated by polyacrylamide gel electrophoresis and transferred electrophoretically to nitrocellulose paper (NCP). The NCP replicas of the gels were incubated with isolated C1q and fresh sera as a source of complement, washed briefly, and overlaid with sensitized sheep erythrocytes (RBC) in agarose. A cluster of four to six molecules between 45 and 53 kDa as well as four others, 34, 30, 26, and 23 kDa, consumed complement thereby preventing complement-mediated lysis of sensitized sheep RBC in the agarose overlay. Additional molecules reactive with C1 were identified by their ability to bind isolated human C1q and to serve as assembly sites for later acting complement components. Sites of localization of complement were demonstrated by incubating NCP replicas of fractionated mitochondria with antisera specific for C1q, C3, C5, and C9, followed by peroxidase-conjugated anti-immunoglobulin and substrate. A total of 12 C1q binding molecules ranging in size from 67 kDa to 23 kDa, which can fix later acting complement components, were identified. At least two of these reacted with antisera prepared against canine cardiac lymph collected in the first 3-4 hours after a 45-minute coronary artery occlusion. These studies present direct evidence that specific molecules, released from subcellular fractions of myocardial cells rich in mitochondria, can activate the complement cascade.

Animals↗

PubMed1989

Canine neutrophil activation by cardiac lymph obtained during reperfusion of ischemic myocardium.

Cardiac lymph from a canine model of myocardial ischemia and reperfusion was examined for evidence of chemotactic activity. Lymph was continuously collected from awake animals before and during a 60-minute coronary artery occlusion and up to 6 hours after the initiation of reperfusion. It was assessed for the ability to activate the following proinflammatory functions in neutrophils isolated from the blood of healthy dogs: 1) morphological changes characteristic of chemotactic stimulation, which were assessed by phase contrast microscopy, 2) orientation of canine neutrophils in a gradient of cardiac lymph, which was assessed in Zigmond chambers, 3) the binding of monoclonal antibodies reactive with CD11b and CD18 adherence glycoproteins, which was assessed by flow cytometry, and 4) adherence of canine neutrophils to monolayers of canine jugular vein endothelium, which was assessed in vitro by a visual assay. Lymph samples collected after 1 hour of reperfusion in animals demonstrating ECG evidence of ischemia and histological evidence of infarction exhibited significant stimulatory activity for each of the functions tested. Shape change-inducing activity was evaluated at more frequent intervals than other functions and was found to peak at 1 hour after initiation of reperfusion and to disappear by 6 hours. In addition, the CD11b/CD18 levels on neutrophils isolated from cardiac lymph collected during reperfusion were significantly greater than neutrophils obtained before or during occlusion. Animals that failed to exhibit evidence of infarction also failed to exhibit increased stimulatory activity in lymph collected during reperfusion, and surface levels of CD11b/CD18 on neutrophils collected from reperfusion lymph were not elevated. This study provides direct evidence supporting the hypothesis that chemotactic activity is generated in ischemic and reperfused myocardium.

Animals↗

PubMed1989

Relationship of hypergammaglobulinemia, circulating immune complexes, and histocompatibility antigen profiles in patients with cystic fibrosis.

Among patients with cystic fibrosis (CF), those in the subset who develop hypergammaglobulinemia and circulating immune complexes often have relatively severe disease and a decreased likelihood of survival. Because Fc receptors have an important role in the removal of immune complexes and because defective Fc receptor function has been associated with inheritance of the histocompatibility antigens HLA DR2 and HLA DR3, we postulated that HLA DR2 and/or HLA DR3 might be genetic markers for this subset of patients with CF. However, in a group of 20 carefully documented patients with CF, we found no association of HLA DR2 or HLA DR3 with serum immunoglobulin, immune complex levels, or evidence of rapidly progressive disease.

Adolescent↗

PubMed1989

Immunologic determinants of head and neck cancer response to induction chemotherapy.

Various measures of immune response were assessed prior to induction chemotherapy (intravenous [IV] cisplatin, fluorouracil [5-FU], and bleomycin) in 43 previously untreated head and neck cancer patients to derive a clinical response prediction model. These were parameters of functional cellular immunity (natural killer [NK] cell activity, lymphocyte blastogenesis response to mitogens), total lymphocyte and lymphocyte subset numbers and percentages, and circulating humoral immunity (total immunoglobulin, immunoglobulin classes, and C1q binding activity [C1q BA]). The C1q BA may reflect levels of circulating immune complexes within peripheral blood. The objective primary tumor response rate was 65% (16 complete responses and 12 partial responses). Univariate logistic regression analysis showed that failure to respond to therapy was significantly related to higher value (vis-à-vis response) of humoral immune parameters total immunoglobulin (Ig), P less than .01; IgG, P less than .01; and C1q BA, P less than .001. No association between cellular immune response measurements and response to chemotherapy was identified. By multivariate logistic regression analysis, only C1q BA levels were predictive of drug therapy responsiveness (P less than .001). Results extend our previous investigations regarding C1q BA measurement in head and neck cancer patients, and show that C1q BA levels add accuracy of prediction of subsequent chemotherapy response to that based solely on standard staging criteria and other parameters of immune status.

Adult↗

PubMed1989

HIV-1-stimulated expression of CD11/CD18 integrins and ICAM-1: a possible mechanism for extravascular dissemination of HIV-1-infected cells.

To identify mechanisms which might facilitate emigration of HIV-1-infected cells from the circulation, we studied the effect of HIV-1 infection on T lymphocyte and monocytoid cell expression of molecules involved in adherence and translocation of leukocytes across endothelial cell barriers. CD11a, CD18, and ICAM-1 were demonstrated on up to 80% of HIV-1-infected H9 T cells by flow cytometry; these molecules were not evident on uninfected H9. CD18 mRNA was detected in HIV-infected, but not in uninfected H9 T cells. Cell surface expression of CD11a and CD18, but not ICAM-1, was increased on HIV-infected, as compared to uninfected U937 and THP1 monocytoid cells. Increased cell surface expression of the leukocyte integrins was associated with a significantly increased tendency of HIV-infected monocytoid cells to adhere to human umbilical vein endothelial cell monolayers or aggregate homotypically. Preincubating the monocytoid cells with anti-CD18 or anti-CD11a or preincubating endothelial cells with anti-ICAM-1 suppressed these cell to cell interactions. These studies suggest that HIV-1 infection stimulates cell surface expression of molecules involved in leukocyte adherence and transendothelial migration in vitro. Similar mechanisms may influence leukocyte trafficking, in vivo, and may play a role in the localization of HIV-1 infected cells in the central nervous system and other tissues.

Antigens, Differentiation↗

PubMed1988

Association of levels of circulating C1q binding macromolecules with induction chemotherapy response in head and neck cancer patients.

Ninety-five untreated patients with squamous cell carcinoma of the upper aerodigestive tract expressed significantly higher levels of C1q-binding macromolecules as compared to 45 noncancer-bearing controls. No relationship between C1q-binding macromolecules and levels of circulating IgG-immune complexes as determined by the solid-phase C1q-binding assay or the C3d-solid-phase assay could be defined suggesting that C1q-binding macromolecules were distinct from IgG-circulating immune complexes. An elevated level of C1q-binding macromolecules within these patients was predictive of subsequent response to induction chemotherapy; those with elevated levels characteristically showed no response. Using multivariate logistic regression analysis including the covariates of American Joint Committee staging parameters as well as C1q assay results, levels of the isolated macromolecules added significant prognostic information as to the probability of chemotherapeutic response. The quantitation of C1q macromolecules has clinical implication as to choice of therapeutic regimens against head and neck cancer. The nature of these substances remains to be defined.

Adult↗

PubMed1988

Mechanism of complement activation after coronary artery occlusion: evidence that myocardial ischemia in dogs causes release of constituents of myocardial subcellular origin that complex with human C1q in vivo.

To evaluate whether ischemic myocardium releases molecules that react with the first component of complement, we studied cardiac lymph from eight dogs before and at intervals after coronary artery occlusion and reperfusion. Before occlusion, the dogs were injected intravenously with radiolabeled human C1q. Labeled C1q could be detected in the cardiac lymph within minutes following injection. Rabbit antisera, prepared against substances precipitated from postreprefusion cardiac lymph by anti-human C1q, also reacted with specific constituents of isolated cardiac sarcoplasmic reticulum and mitochondria. To evaluate whether mitochondria are the source of these C1q-binding proteins, we isolated intramyofibrillar and subsarcolemmal mitochondria from canine heart and incubated sonicates of these with purified C1q, immobilized on nitrocellulose. Molecules bound to the immobilized C1q were removed with 0.1% sodium dodecyl sulfate, fractionated under reducing conditions by polyacrylamide gel electrophoresis, and transferred electrophoretically to nitrocellulose paper. Antisera prepared against postreperfusion lymph reacted with a 31,000-32,000-dalton protein in these nitrocellulose paper replicas. Since this protein originates from mitochondria, binds to C1q, and is recognized by antibodies made against postreperfusion lymph, this protein is likely to be one of the subcellular constituents that, upon release from ischemic cells, activates the complement cascade. To evaluate the clinical relevance of these observations, we tested sera from 53 patients obtained 48-72 hours after hospitalization for suspected myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1986

Antibody development to viral and allogeneic tumor cell-associated antigens in patients with malignant melanoma and ovarian carcinoma treated with lysates of virus-infected tumor cells.

Pre- and postimmunization sera from six malignant melanoma and six ovarian carcinoma patients were used to investigate the humoral immune response to antigens expressed in extracts of allogeneic tumor cells and lysates of these same cells infected with virus. Nitrocellulose paper replicas of cell extracts, fractionated by polyacrylamide gel electrophoresis, were used as antigenic targets. Antibodies that bound to tumor cell antigens of defined molecular weight were identified with enzyme-linked probes specific for human immunoglobulins G, A, and M. Prior to therapy, all sera reacted with one or more antigens expressed by the unmodified tumor cells. Postimmunization sera from two malignant melanoma patients and one ovarian carcinoma patient reacted with antigens in extracts of uninfected tumor cells. These same antigens were not detected by preimmunization sera. Most postimmunization antibody responses were directed against antigens associated with the infecting virus itself and antigens found in extracts of virus-infected but not in extracts of uninfected tumor cells. These results suggest that treatment with lysates of virus-infected allogeneic human tumor cells elicits humoral immune responses against: (a) tumor cell-associated antigens; (b) antigens that are specifically virus associated; and (c) antigens that may be virus induced or virus modified cytoplasmic or nuclear antigens.

Allantois↗

PubMed1985

Selective accumulation of the first component of complement and leukocytes in ischemic canine heart muscle. A possible initiator of an extra myocardial mechanism of ischemic injury.

Myocardial concentrations of C1q, a subunit of the first component of complement, were measured 5-120 minutes after ligation of a coronary artery in dogs injected with 125I-labeled human C1q and 131I-labeled human albumin. The 131I-labeled human serum albumin was used as a plasma protein marker. Ischemic regions of myocardium were defined by measuring regional myocardial blood flow by the reference sample method at intervals after coronary artery occlusion. Significant accumulations of 125I-C1q were demonstrated in the ischemic myocardium after coronary artery occlusions lasting 45 minutes. Some localization of C1q in ischemic myocardium was observed after a 15-minute occlusion, but the accumulations of C1q achieved in this case were not statistically significant. After coronary artery occlusions lasting greater than or equal to 45 minutes, left ventricular concentrations of C1q correlated reciprocally with regional myocardial blood flow. Moreover, high concentrations of C1q persisted in formerly ischemic segments after reperfusion. Radiolabeled neutrophils also accumulated selectively in ischemic segments relatively rich in C1q. It is suggested that complement activation may initiate the neutrophil-dependent portion of ischemic injury, delineated in recent years, that is associated with free radical release by phagocytic cells.

Animals↗

PubMed1985

Human peripheral blood monocytes release a 30,000 dalton factor (30 KD MF) that stimulates immunoglobulin production by activated B cells.

Supernatants (SN) of well-washed adherent human monocytes, obtained from T cell-depleted peripheral blood mononuclear cells, contain a 30,000 dalton protein (30 KD MF) that increases immunoglobulin (Ig) synthesis by EBV-activated B cells two- to fourfold. This factor is released spontaneously during the first 20 hr after monocytes are placed in culture. SN containing 30 KD MF are inactive in the thymocyte co-stimulator assay, under conditions that will detect as little as 0.5 U of purified IL 1. The addition of autologous T cells to isolated adherent monocytes, previously depleted of T cells, suppresses the release or activity of this B cell stimulator in a dose-dependent manner. In addition, 30 KD MF stimulates a two- to fourfold increase in IgA production by cells of an EBV-transformed B cell line (JB/FF line) without increasing incorporation of [3H]thymidine. In contrast, stimulation of this B cell line with up to 10 U of purified IL 1 increases IgA synthesis by less than 50%, and addition of up to 100 U of recombinant IL 2 causes no change whatsoever in IgA production. However, co-stimulation with 30 KD MF and recombinant IL 2 or recombinant gamma-interferon induces more Ig production than is caused by the monocyte factor alone. These observations suggest that the monocyte, in addition to acting as an antigen-presenting cell and source of IL 1, facilitates B cell differentiation by producing a factor which acts both independently and in synergy with cytokines produced by T cells to stimulate Ig production by B lymphocytes.

Adult↗

PubMed1984

Extended haplotypes of chromosome 6 in adult rheumatoid arthritis.

In 46 patients with rheumatoid arthritis (RA) the allele C4B*3 occurred in 6 patients, while among 350 normal controls, it occurred 6 times (P less than 0.00002). Among 9 white and 1 black families, each of which had 2 or more members with RA, there were 36 haplotypes associated with RA. An extended haplotype (specific HLA-B, DR, complotype haplotypes in significant linkage disequilibrium) containing C4B*3: HLA-B15, DR4, BF*S, C2*C, C4A*3, C4B*3, was found twice (P less than 0.001) among whites with the disease-associated chromosomes.

Adult↗

PubMed1984

Measurement of a monoclonal antibody-defined, melanoma-associated antigen in human sera: correlation of circulating antigen levels with tumor burden.

Quantities of a 100,000-mol wt human melanoma-associated antigen (MAA), defined by both monoclonal and polyclonal xenoantibodies, were measured in sera of 32 patients with malignant melanoma and 15 carefully documented healthy volunteers by use of an amplified sandwich enzyme-linked immunoabsorbent assay. Detectable levels of MAA were found in all normal adult sera. Five of 10 patients with stage III and 9 of 16 patients with stage IV disease had antigen levels that exceeded. the 95th percentile of serum levels in the normal donors (P less than .001). Elevated levels of the 100K MAA were associated with evidence of residual tumor (P less than .008): Only 3 of 13 patients with no evidence of tumor had abnormal values, whereas 9 of 16 patients with evident tumor had increased serum levels. Levels of the 100K MAA were unrelated to the levels of soluble immune complexes as detected by the fluid-phase C1q binding test. Molecular evaluation of the 100K MAA in serum indicated that the molecule associated with albumin in a strong, noncovalent manner. When the complex was dissociated by treatment with sodium dodecyl sulfate, the 100K MAA in serum comigrated with the molecule from spent culture medium of human melanoma cells. Antigen levels in sera were measured under these dissociating conditions. These studies suggest that measurement of the 100K MAA may be useful in monitoring tumor burden in patients with malignant melanoma.

Antibodies, Monoclonal↗

PubMed1984

Association of circulating immune complexes with cytogenetic abnormalities but not with prognosis in acute nonlymphocytic leukemia.

Sera from 91 adult acute nonlymphocytic leukemia patients were tested for circulating immune complexes by the C1q binding test. In 42 patients tested prior to the initiation of therapy, C1q binding activity was inversely correlated with leukemic infiltrate of the bone marrow (rs = -0.34, p less than 0.02), but it was not related to peripheral white blood cell count or presence of infection. Patients with abnormal C1q binding activities (greater than 6%) were more likely to have cytogenetic abnormalities in their bone marrow (p = 0.02); the most frequent abnormality was an extra No. 8 chromosome. The median survival of 8 patients with abnormal values was 1.5 months as compared to 7.8 months in 34 patients with normal values. However, the C1q binding test did not identify patients likely to achieve remission; and after remission was achieved, it did not identify those likely to relapse. Differences between these findings and those recently published by other investigators are discussed.

Acute Disease↗